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linux/net/ipv6/seg6_local.c

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treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-27 09:55:01 +03:00
// SPDX-License-Identifier: GPL-2.0-or-later
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:26 +03:00
/*
* SR-IPv6 implementation
*
ipv6: sr: Add seg6local action End.BPF This patch adds the End.BPF action to the LWT seg6local infrastructure. This action works like any other seg6local End action, meaning that an IPv6 header with SRH is needed, whose DA has to be equal to the SID of the action. It will also advance the SRH to the next segment, the BPF program does not have to take care of this. Since the BPF program may not be a source of instability in the kernel, it is important to ensure that the integrity of the packet is maintained before yielding it back to the IPv6 layer. The hook hence keeps track if the SRH has been altered through the helpers, and re-validates its content if needed with seg6_validate_srh. The state kept for validation is stored in a per-CPU buffer. The BPF program is not allowed to directly write into the packet, and only some fields of the SRH can be altered through the helper bpf_lwt_seg6_store_bytes. Performances profiling has shown that the SRH re-validation does not induce a significant overhead. If the altered SRH is deemed as invalid, the packet is dropped. This validation is also done before executing any action through bpf_lwt_seg6_action, and will not be performed again if the SRH is not modified after calling the action. The BPF program may return 3 types of return codes: - BPF_OK: the End.BPF action will look up the next destination through seg6_lookup_nexthop. - BPF_REDIRECT: if an action has been executed through the bpf_lwt_seg6_action helper, the BPF program should return this value, as the skb's destination is already set and the default lookup should not be performed. - BPF_DROP : the packet will be dropped. Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-20 16:58:16 +03:00
* Authors:
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:26 +03:00
* David Lebrun <david.lebrun@uclouvain.be>
ipv6: sr: Add seg6local action End.BPF This patch adds the End.BPF action to the LWT seg6local infrastructure. This action works like any other seg6local End action, meaning that an IPv6 header with SRH is needed, whose DA has to be equal to the SID of the action. It will also advance the SRH to the next segment, the BPF program does not have to take care of this. Since the BPF program may not be a source of instability in the kernel, it is important to ensure that the integrity of the packet is maintained before yielding it back to the IPv6 layer. The hook hence keeps track if the SRH has been altered through the helpers, and re-validates its content if needed with seg6_validate_srh. The state kept for validation is stored in a per-CPU buffer. The BPF program is not allowed to directly write into the packet, and only some fields of the SRH can be altered through the helper bpf_lwt_seg6_store_bytes. Performances profiling has shown that the SRH re-validation does not induce a significant overhead. If the altered SRH is deemed as invalid, the packet is dropped. This validation is also done before executing any action through bpf_lwt_seg6_action, and will not be performed again if the SRH is not modified after calling the action. The BPF program may return 3 types of return codes: - BPF_OK: the End.BPF action will look up the next destination through seg6_lookup_nexthop. - BPF_REDIRECT: if an action has been executed through the bpf_lwt_seg6_action helper, the BPF program should return this value, as the skb's destination is already set and the default lookup should not be performed. - BPF_DROP : the packet will be dropped. Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-20 16:58:16 +03:00
* eBPF support: Mathieu Xhonneux <m.xhonneux@gmail.com>
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:26 +03:00
*/
net: Don't include filter.h from net/sock.h sock.h is pretty heavily used (5k objects rebuilt on x86 after it's touched). We can drop the include of filter.h from it and add a forward declaration of struct sk_filter instead. This decreases the number of rebuilt objects when bpf.h is touched from ~5k to ~1k. There's a lot of missing includes this was masking. Primarily in networking tho, this time. Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Marc Kleine-Budde <mkl@pengutronix.de> Acked-by: Florian Fainelli <f.fainelli@gmail.com> Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com> Acked-by: Stefano Garzarella <sgarzare@redhat.com> Link: https://lore.kernel.org/bpf/20211229004913.513372-1-kuba@kernel.org
2021-12-29 03:49:13 +03:00
#include <linux/filter.h>
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:26 +03:00
#include <linux/types.h>
#include <linux/skbuff.h>
#include <linux/net.h>
#include <linux/module.h>
#include <net/ip.h>
#include <net/lwtunnel.h>
#include <net/netevent.h>
#include <net/netns/generic.h>
#include <net/ip6_fib.h>
#include <net/route.h>
#include <net/seg6.h>
#include <linux/seg6.h>
#include <linux/seg6_local.h>
#include <net/addrconf.h>
#include <net/ip6_route.h>
#include <net/dst_cache.h>
ipv6: sr: remove SKB_GSO_IPXIP6 on End.D* actions After LRO/GRO is applied, SRv6 encapsulated packets have SKB_GSO_IPXIP6 feature flag, and this flag must be removed right after decapulation procedure. Currently, SKB_GSO_IPXIP6 flag is not removed on End.D* actions, which creates inconsistent packet state, that is, a normal TCP/IP packets have the SKB_GSO_IPXIP6 flag. This behavior can cause unexpected fallback to GSO on routing to netdevices that do not support SKB_GSO_IPXIP6. For example, on inter-VRF forwarding, decapsulated packets separated into small packets by GSO because VRF devices do not support TSO for packets with SKB_GSO_IPXIP6 flag, and this degrades forwarding performance. This patch removes encapsulation related GSO flags from the skb right after the End.D* action is applied. Fixes: d7a669dd2f8b ("ipv6: sr: add helper functions for seg6local") Signed-off-by: Yuki Taguchi <tagyounit@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-20 07:48:37 +03:00
#include <net/ip_tunnels.h>
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:26 +03:00
#ifdef CONFIG_IPV6_SEG6_HMAC
#include <net/seg6_hmac.h>
#endif
ipv6: sr: export function lookup_nexthop The function lookup_nexthop is essential to implement most of the seg6local actions. As we want to provide a BPF helper allowing to apply some of these actions on the packet being processed, the helper should be able to call this function, hence the need to make it public. Moreover, if one argument is incorrect or if the next hop can not be found, an error should be returned by the BPF helper so the BPF program can adapt its processing of the packet (return an error, properly force the drop, ...). This patch hence makes this function return dst->error to indicate a possible error. Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-20 16:58:13 +03:00
#include <net/seg6_local.h>
ipv6: sr: implement additional seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END_T: regular SRH processing and forward to the next-hop looked up in the specified routing table. - SEG6_LOCAL_ACTION_END_DX2: decapsulate an L2 frame and forward it to the specified network interface. - SEG6_LOCAL_ACTION_END_DX4: decapsulate an IPv4 packet and forward it, possibly to the specified next-hop. - SEG6_LOCAL_ACTION_END_DT6: decapsulate an IPv6 packet and forward it to the next-hop looked up in the specified routing table. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 10:58:17 +03:00
#include <linux/etherdevice.h>
ipv6: sr: Add seg6local action End.BPF This patch adds the End.BPF action to the LWT seg6local infrastructure. This action works like any other seg6local End action, meaning that an IPv6 header with SRH is needed, whose DA has to be equal to the SID of the action. It will also advance the SRH to the next segment, the BPF program does not have to take care of this. Since the BPF program may not be a source of instability in the kernel, it is important to ensure that the integrity of the packet is maintained before yielding it back to the IPv6 layer. The hook hence keeps track if the SRH has been altered through the helpers, and re-validates its content if needed with seg6_validate_srh. The state kept for validation is stored in a per-CPU buffer. The BPF program is not allowed to directly write into the packet, and only some fields of the SRH can be altered through the helper bpf_lwt_seg6_store_bytes. Performances profiling has shown that the SRH re-validation does not induce a significant overhead. If the altered SRH is deemed as invalid, the packet is dropped. This validation is also done before executing any action through bpf_lwt_seg6_action, and will not be performed again if the SRH is not modified after calling the action. The BPF program may return 3 types of return codes: - BPF_OK: the End.BPF action will look up the next destination through seg6_lookup_nexthop. - BPF_REDIRECT: if an action has been executed through the bpf_lwt_seg6_action helper, the BPF program should return this value, as the skb's destination is already set and the default lookup should not be performed. - BPF_DROP : the packet will be dropped. Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-20 16:58:16 +03:00
#include <linux/bpf.h>
netfilter: add netfilter hooks to SRv6 data plane This patch introduces netfilter hooks for solving the problem that conntrack couldn't record both inner flows and outer flows. This patch also introduces a new sysctl toggle for enabling lightweight tunnel netfilter hooks. Signed-off-by: Ryoga Saito <contact@proelbtn.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-08-17 11:39:37 +03:00
#include <linux/netfilter.h>
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:26 +03:00
seg6: fool-proof the processing of SRv6 behavior attributes The set of required attributes for a given SRv6 behavior is identified using a bitmap stored in an unsigned long, since the initial design of SRv6 networking in Linux. Recently the same approach has been used for identifying the optional attributes. However, the number of attributes supported by SRv6 behaviors depends on the size of the unsigned long type which changes with the architecture. Indeed, on a 64-bit architecture, an SRv6 behavior can support up to 64 attributes while on a 32-bit architecture it can support at most 32 attributes. To fool-proof the processing of SRv6 behaviors we verify, at compile time, that the set of all supported SRv6 attributes can be encoded into a bitmap stored in an unsigned long. Otherwise, kernel build fails forcing developers to reconsider adding a new attribute or extend the total number of supported attributes by the SRv6 behaviors. Moreover, we replace all patterns (1 << i) with the macro SEG6_F_ATTR(i) in order to address potential overflow issues caused by 32-bit signed arithmetic. Thanks to Colin Ian King for catching the overflow problem, providing a solution and inspiring this patch. Thanks to Jakub Kicinski for his useful suggestions during the design of this patch. v2: - remove the SEG6_LOCAL_MAX_SUPP which is not strictly needed: it can be derived from the unsigned long type. Thanks to David Ahern for pointing it out. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/r/20210206170934.5982-1-andrea.mayer@uniroma2.it Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-02-06 20:09:34 +03:00
#define SEG6_F_ATTR(i) BIT(i)
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:26 +03:00
struct seg6_local_lwt;
seg6: add callbacks for customizing the creation/destruction of a behavior We introduce two callbacks used for customizing the creation/destruction of a SRv6 behavior. Such callbacks are defined in the new struct seg6_local_lwtunnel_ops and hereafter we provide a brief description of them: - build_state(...): used for calling the custom constructor of the behavior during its initialization phase and after all the attributes have been parsed successfully; - destroy_state(...): used for calling the custom destructor of the behavior before it is completely destroyed. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:13 +03:00
/* callbacks used for customizing the creation and destruction of a behavior */
struct seg6_local_lwtunnel_ops {
int (*build_state)(struct seg6_local_lwt *slwt, const void *cfg,
struct netlink_ext_ack *extack);
void (*destroy_state)(struct seg6_local_lwt *slwt);
};
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:26 +03:00
struct seg6_action_desc {
int action;
unsigned long attrs;
seg6: add support for optional attributes in SRv6 behaviors Before this patch, each SRv6 behavior specifies a set of required attributes that must be provided by the userspace application when such behavior is going to be instantiated. If at least one of the required attributes is not provided, the creation of the behavior fails. The SRv6 behavior framework lacks a way to manage optional attributes. By definition, an optional attribute for a SRv6 behavior consists of an attribute which may or may not be provided by the userspace. Therefore, if an optional attribute is missing (and thus not supplied by the user) the creation of the behavior goes ahead without any issue. This patch explicitly differentiates the required attributes from the optional attributes. In particular, each behavior can declare a set of required attributes and a set of optional ones. The semantic of the required attributes remains *totally* unaffected by this patch. The introduction of the optional attributes does NOT impact on the backward compatibility of the existing SRv6 behaviors. It is essential to note that if an (optional or required) attribute is supplied to a SRv6 behavior which does not expect it, the behavior simply discards such attribute without generating any error or warning. This operating mode remained unchanged both before and after the introduction of the optional attributes extension. The optional attributes are one of the key components used to implement the SRv6 End.DT6 behavior based on the Virtual Routing and Forwarding (VRF) framework. The optional attributes make possible the coexistence of the already existing SRv6 End.DT6 implementation with the new SRv6 End.DT6 VRF-based implementation without breaking any backward compatibility. Further details on the SRv6 End.DT6 behavior (VRF mode) are reported in subsequent patches. From the userspace point of view, the support for optional attributes DO NOT require any changes to the userspace applications, i.e: iproute2 unless new attributes (required or optional) are needed. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:12 +03:00
/* The optattrs field is used for specifying all the optional
* attributes supported by a specific behavior.
* It means that if one of these attributes is not provided in the
* netlink message during the behavior creation, no errors will be
* returned to the userspace.
*
* Each attribute can be only of two types (mutually exclusive):
* 1) required or 2) optional.
* Every user MUST obey to this rule! If you set an attribute as
* required the same attribute CANNOT be set as optional and vice
* versa.
*/
unsigned long optattrs;
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:26 +03:00
int (*input)(struct sk_buff *skb, struct seg6_local_lwt *slwt);
int static_headroom;
seg6: add callbacks for customizing the creation/destruction of a behavior We introduce two callbacks used for customizing the creation/destruction of a SRv6 behavior. Such callbacks are defined in the new struct seg6_local_lwtunnel_ops and hereafter we provide a brief description of them: - build_state(...): used for calling the custom constructor of the behavior during its initialization phase and after all the attributes have been parsed successfully; - destroy_state(...): used for calling the custom destructor of the behavior before it is completely destroyed. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:13 +03:00
struct seg6_local_lwtunnel_ops slwt_ops;
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:26 +03:00
};
ipv6: sr: Add seg6local action End.BPF This patch adds the End.BPF action to the LWT seg6local infrastructure. This action works like any other seg6local End action, meaning that an IPv6 header with SRH is needed, whose DA has to be equal to the SID of the action. It will also advance the SRH to the next segment, the BPF program does not have to take care of this. Since the BPF program may not be a source of instability in the kernel, it is important to ensure that the integrity of the packet is maintained before yielding it back to the IPv6 layer. The hook hence keeps track if the SRH has been altered through the helpers, and re-validates its content if needed with seg6_validate_srh. The state kept for validation is stored in a per-CPU buffer. The BPF program is not allowed to directly write into the packet, and only some fields of the SRH can be altered through the helper bpf_lwt_seg6_store_bytes. Performances profiling has shown that the SRH re-validation does not induce a significant overhead. If the altered SRH is deemed as invalid, the packet is dropped. This validation is also done before executing any action through bpf_lwt_seg6_action, and will not be performed again if the SRH is not modified after calling the action. The BPF program may return 3 types of return codes: - BPF_OK: the End.BPF action will look up the next destination through seg6_lookup_nexthop. - BPF_REDIRECT: if an action has been executed through the bpf_lwt_seg6_action helper, the BPF program should return this value, as the skb's destination is already set and the default lookup should not be performed. - BPF_DROP : the packet will be dropped. Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-20 16:58:16 +03:00
struct bpf_lwt_prog {
struct bpf_prog *prog;
char *name;
};
seg6: add NEXT-C-SID support for SRv6 End behavior The NEXT-C-SID mechanism described in [1] offers the possibility of encoding several SRv6 segments within a single 128 bit SID address. Such a SID address is called a Compressed SID (C-SID) container. In this way, the length of the SID List can be drastically reduced. A SID instantiated with the NEXT-C-SID flavor considers an IPv6 address logically structured in three main blocks: i) Locator-Block; ii) Locator-Node Function; iii) Argument. C-SID container +------------------------------------------------------------------+ | Locator-Block |Loc-Node| Argument | | |Function| | +------------------------------------------------------------------+ <--------- B -----------> <- NF -> <------------- A ---------------> (i) The Locator-Block can be any IPv6 prefix available to the provider; (ii) The Locator-Node Function represents the node and the function to be triggered when a packet is received on the node; (iii) The Argument carries the remaining C-SIDs in the current C-SID container. The NEXT-C-SID mechanism relies on the "flavors" framework defined in [2]. The flavors represent additional operations that can modify or extend a subset of the existing behaviors. This patch introduces the support for flavors in SRv6 End behavior implementing the NEXT-C-SID one. An SRv6 End behavior with NEXT-C-SID flavor works as an End behavior but it is capable of processing the compressed SID List encoded in C-SID containers. An SRv6 End behavior with NEXT-C-SID flavor can be configured to support user-provided Locator-Block and Locator-Node Function lengths. In this implementation, such lengths must be evenly divisible by 8 (i.e. must be byte-aligned), otherwise the kernel informs the user about invalid values with a meaningful error code and message through netlink_ext_ack. If Locator-Block and/or Locator-Node Function lengths are not provided by the user during configuration of an SRv6 End behavior instance with NEXT-C-SID flavor, the kernel will choose their default values i.e., 32-bit Locator-Block and 16-bit Locator-Node Function. [1] - https://datatracker.ietf.org/doc/html/draft-ietf-spring-srv6-srh-compression [2] - https://datatracker.ietf.org/doc/html/rfc8986 Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-09-12 20:16:18 +03:00
/* default length values (expressed in bits) for both Locator-Block and
* Locator-Node Function.
*
* Both SEG6_LOCAL_LCBLOCK_DBITS and SEG6_LOCAL_LCNODE_FN_DBITS *must* be:
* i) greater than 0;
* ii) evenly divisible by 8. In other terms, the lengths of the
* Locator-Block and Locator-Node Function must be byte-aligned (we can
* relax this constraint in the future if really needed).
*
* Moreover, a third condition must hold:
* iii) SEG6_LOCAL_LCBLOCK_DBITS + SEG6_LOCAL_LCNODE_FN_DBITS <= 128.
*
* The correctness of SEG6_LOCAL_LCBLOCK_DBITS and SEG6_LOCAL_LCNODE_FN_DBITS
* values are checked during the kernel compilation. If the compilation stops,
* check the value of these parameters to see if they meet conditions (i), (ii)
* and (iii).
*/
#define SEG6_LOCAL_LCBLOCK_DBITS 32
#define SEG6_LOCAL_LCNODE_FN_DBITS 16
/* The following next_csid_chk_{cntr,lcblock,lcblock_fn}_bits macros can be
* used directly to check whether the lengths (in bits) of Locator-Block and
* Locator-Node Function are valid according to (i), (ii), (iii).
*/
#define next_csid_chk_cntr_bits(blen, flen) \
((blen) + (flen) > 128)
#define next_csid_chk_lcblock_bits(blen) \
({ \
typeof(blen) __tmp = blen; \
(!__tmp || __tmp > 120 || (__tmp & 0x07)); \
})
#define next_csid_chk_lcnode_fn_bits(flen) \
next_csid_chk_lcblock_bits(flen)
seg6: add PSP flavor support for SRv6 End behavior The "flavors" framework defined in RFC8986 [1] represents additional operations that can modify or extend a subset of existing behaviors such as SRv6 End, End.X and End.T. We report these flavors hereafter: - Penultimate Segment Pop (PSP); - Ultimate Segment Pop (USP); - Ultimate Segment Decapsulation (USD). Depending on how the Segment Routing Header (SRH) has to be handled, an SRv6 End* behavior can support these flavors either individually or in combinations. In this patch, we only consider the PSP flavor for the SRv6 End behavior. A PSP enabled SRv6 End behavior is used by the Source/Ingress SR node (i.e., the one applying the SRv6 Policy) when it needs to instruct the penultimate SR Endpoint node listed in the SID List (carried by the SRH) to remove the SRH from the IPv6 header. Specifically, a PSP enabled SRv6 End behavior processes the SRH by: i) decreasing the Segment Left (SL) from 1 to 0; ii) copying the Last Segment IDentifier (SID) into the IPv6 Destination Address (DA); iii) removing (i.e., popping) the outer SRH from the extension headers following the IPv6 header. It is important to note that PSP operation (steps i, ii, iii) takes place only at a penultimate SR Segment Endpoint node (i.e., when the SL=1) and does not happen at non-penultimate Endpoint nodes. Indeed, when a SID of PSP flavor is processed at a non-penultimate SR Segment Endpoint node, the PSP operation is not performed because it would not be possible to decrease the SL from 1 to 0. SL=2 SL=1 SL=0 | | | For example, given the SRv6 policy (SID List := < X, Y, Z >): - a PSP enabled SRv6 End behavior bound to SID "Y" will apply the PSP operation as Segment Left (SL) is 1, corresponding to the Penultimate Segment of the SID List; - a PSP enabled SRv6 End behavior bound to SID "X" will *NOT* apply the PSP operation as the Segment Left is 2. This behavior instance will apply the "standard" End packet processing, ignoring the configured PSP flavor at all. [1] - RFC8986: https://datatracker.ietf.org/doc/html/rfc8986 Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2023-02-15 16:46:58 +03:00
#define SEG6_F_LOCAL_FLV_OP(flvname) BIT(SEG6_LOCAL_FLV_OP_##flvname)
#define SEG6_F_LOCAL_FLV_PSP SEG6_F_LOCAL_FLV_OP(PSP)
/* Supported RFC8986 Flavor operations are reported in this bitmask */
#define SEG6_LOCAL_FLV8986_SUPP_OPS SEG6_F_LOCAL_FLV_PSP
seg6: add NEXT-C-SID support for SRv6 End behavior The NEXT-C-SID mechanism described in [1] offers the possibility of encoding several SRv6 segments within a single 128 bit SID address. Such a SID address is called a Compressed SID (C-SID) container. In this way, the length of the SID List can be drastically reduced. A SID instantiated with the NEXT-C-SID flavor considers an IPv6 address logically structured in three main blocks: i) Locator-Block; ii) Locator-Node Function; iii) Argument. C-SID container +------------------------------------------------------------------+ | Locator-Block |Loc-Node| Argument | | |Function| | +------------------------------------------------------------------+ <--------- B -----------> <- NF -> <------------- A ---------------> (i) The Locator-Block can be any IPv6 prefix available to the provider; (ii) The Locator-Node Function represents the node and the function to be triggered when a packet is received on the node; (iii) The Argument carries the remaining C-SIDs in the current C-SID container. The NEXT-C-SID mechanism relies on the "flavors" framework defined in [2]. The flavors represent additional operations that can modify or extend a subset of the existing behaviors. This patch introduces the support for flavors in SRv6 End behavior implementing the NEXT-C-SID one. An SRv6 End behavior with NEXT-C-SID flavor works as an End behavior but it is capable of processing the compressed SID List encoded in C-SID containers. An SRv6 End behavior with NEXT-C-SID flavor can be configured to support user-provided Locator-Block and Locator-Node Function lengths. In this implementation, such lengths must be evenly divisible by 8 (i.e. must be byte-aligned), otherwise the kernel informs the user about invalid values with a meaningful error code and message through netlink_ext_ack. If Locator-Block and/or Locator-Node Function lengths are not provided by the user during configuration of an SRv6 End behavior instance with NEXT-C-SID flavor, the kernel will choose their default values i.e., 32-bit Locator-Block and 16-bit Locator-Node Function. [1] - https://datatracker.ietf.org/doc/html/draft-ietf-spring-srv6-srh-compression [2] - https://datatracker.ietf.org/doc/html/rfc8986 Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-09-12 20:16:18 +03:00
/* Supported Flavor operations are reported in this bitmask */
seg6: add PSP flavor support for SRv6 End behavior The "flavors" framework defined in RFC8986 [1] represents additional operations that can modify or extend a subset of existing behaviors such as SRv6 End, End.X and End.T. We report these flavors hereafter: - Penultimate Segment Pop (PSP); - Ultimate Segment Pop (USP); - Ultimate Segment Decapsulation (USD). Depending on how the Segment Routing Header (SRH) has to be handled, an SRv6 End* behavior can support these flavors either individually or in combinations. In this patch, we only consider the PSP flavor for the SRv6 End behavior. A PSP enabled SRv6 End behavior is used by the Source/Ingress SR node (i.e., the one applying the SRv6 Policy) when it needs to instruct the penultimate SR Endpoint node listed in the SID List (carried by the SRH) to remove the SRH from the IPv6 header. Specifically, a PSP enabled SRv6 End behavior processes the SRH by: i) decreasing the Segment Left (SL) from 1 to 0; ii) copying the Last Segment IDentifier (SID) into the IPv6 Destination Address (DA); iii) removing (i.e., popping) the outer SRH from the extension headers following the IPv6 header. It is important to note that PSP operation (steps i, ii, iii) takes place only at a penultimate SR Segment Endpoint node (i.e., when the SL=1) and does not happen at non-penultimate Endpoint nodes. Indeed, when a SID of PSP flavor is processed at a non-penultimate SR Segment Endpoint node, the PSP operation is not performed because it would not be possible to decrease the SL from 1 to 0. SL=2 SL=1 SL=0 | | | For example, given the SRv6 policy (SID List := < X, Y, Z >): - a PSP enabled SRv6 End behavior bound to SID "Y" will apply the PSP operation as Segment Left (SL) is 1, corresponding to the Penultimate Segment of the SID List; - a PSP enabled SRv6 End behavior bound to SID "X" will *NOT* apply the PSP operation as the Segment Left is 2. This behavior instance will apply the "standard" End packet processing, ignoring the configured PSP flavor at all. [1] - RFC8986: https://datatracker.ietf.org/doc/html/rfc8986 Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2023-02-15 16:46:58 +03:00
#define SEG6_LOCAL_FLV_SUPP_OPS (SEG6_F_LOCAL_FLV_OP(NEXT_CSID) | \
SEG6_LOCAL_FLV8986_SUPP_OPS)
seg6: add NEXT-C-SID support for SRv6 End behavior The NEXT-C-SID mechanism described in [1] offers the possibility of encoding several SRv6 segments within a single 128 bit SID address. Such a SID address is called a Compressed SID (C-SID) container. In this way, the length of the SID List can be drastically reduced. A SID instantiated with the NEXT-C-SID flavor considers an IPv6 address logically structured in three main blocks: i) Locator-Block; ii) Locator-Node Function; iii) Argument. C-SID container +------------------------------------------------------------------+ | Locator-Block |Loc-Node| Argument | | |Function| | +------------------------------------------------------------------+ <--------- B -----------> <- NF -> <------------- A ---------------> (i) The Locator-Block can be any IPv6 prefix available to the provider; (ii) The Locator-Node Function represents the node and the function to be triggered when a packet is received on the node; (iii) The Argument carries the remaining C-SIDs in the current C-SID container. The NEXT-C-SID mechanism relies on the "flavors" framework defined in [2]. The flavors represent additional operations that can modify or extend a subset of the existing behaviors. This patch introduces the support for flavors in SRv6 End behavior implementing the NEXT-C-SID one. An SRv6 End behavior with NEXT-C-SID flavor works as an End behavior but it is capable of processing the compressed SID List encoded in C-SID containers. An SRv6 End behavior with NEXT-C-SID flavor can be configured to support user-provided Locator-Block and Locator-Node Function lengths. In this implementation, such lengths must be evenly divisible by 8 (i.e. must be byte-aligned), otherwise the kernel informs the user about invalid values with a meaningful error code and message through netlink_ext_ack. If Locator-Block and/or Locator-Node Function lengths are not provided by the user during configuration of an SRv6 End behavior instance with NEXT-C-SID flavor, the kernel will choose their default values i.e., 32-bit Locator-Block and 16-bit Locator-Node Function. [1] - https://datatracker.ietf.org/doc/html/draft-ietf-spring-srv6-srh-compression [2] - https://datatracker.ietf.org/doc/html/rfc8986 Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-09-12 20:16:18 +03:00
struct seg6_flavors_info {
/* Flavor operations */
__u32 flv_ops;
/* Locator-Block length, expressed in bits */
__u8 lcblock_bits;
/* Locator-Node Function length, expressed in bits*/
__u8 lcnode_func_bits;
};
seg6: add support for the SRv6 End.DT4 behavior SRv6 End.DT4 is defined in the SRv6 Network Programming [1]. The SRv6 End.DT4 is used to implement IPv4 L3VPN use-cases in multi-tenants environments. It decapsulates the received packets and it performs IPv4 routing lookup in the routing table of the tenant. The SRv6 End.DT4 Linux implementation leverages a VRF device in order to force the routing lookup into the associated routing table. To make the End.DT4 work properly, it must be guaranteed that the routing table used for routing lookup operations is bound to one and only one VRF during the tunnel creation. Such constraint has to be enforced by enabling the VRF strict_mode sysctl parameter, i.e: $ sysctl -wq net.vrf.strict_mode=1. At JANOG44, LINE corporation presented their multi-tenant DC architecture using SRv6 [2]. In the slides, they reported that the Linux kernel is missing the support of SRv6 End.DT4 behavior. The SRv6 End.DT4 behavior can be instantiated using a command similar to the following: $ ip route add 2001:db8::1 encap seg6local action End.DT4 vrftable 100 dev eth0 We introduce the "vrftable" extension in iproute2 in a following patch. [1] https://tools.ietf.org/html/draft-ietf-spring-srv6-network-programming [2] https://speakerdeck.com/line_developers/line-data-center-networking-with-srv6 Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:14 +03:00
enum seg6_end_dt_mode {
DT_INVALID_MODE = -EINVAL,
DT_LEGACY_MODE = 0,
DT_VRF_MODE = 1,
};
struct seg6_end_dt_info {
enum seg6_end_dt_mode mode;
struct net *net;
/* VRF device associated to the routing table used by the SRv6
* End.DT4/DT6 behavior for routing IPv4/IPv6 packets.
*/
int vrf_ifindex;
int vrf_table;
seg6: add support for SRv6 End.DT46 Behavior IETF RFC 8986 [1] includes the definition of SRv6 End.DT4, End.DT6, and End.DT46 Behaviors. The current SRv6 code in the Linux kernel only implements End.DT4 and End.DT6 which can be used respectively to support IPv4-in-IPv6 and IPv6-in-IPv6 VPNs. With End.DT4 and End.DT6 it is not possible to create a single SRv6 VPN tunnel to carry both IPv4 and IPv6 traffic. The proposed End.DT46 implementation is meant to support the decapsulation of IPv4 and IPv6 traffic coming from a single SRv6 tunnel. The implementation of the SRv6 End.DT46 Behavior in the Linux kernel greatly simplifies the setup and operations of SRv6 VPNs. The SRv6 End.DT46 Behavior leverages the infrastructure of SRv6 End.DT{4,6} Behaviors implemented so far, because it makes use of a VRF device in order to force the routing lookup into the associated routing table. To make the End.DT46 work properly, it must be guaranteed that the routing table used for routing lookup operations is bound to one and only one VRF during the tunnel creation. Such constraint has to be enforced by enabling the VRF strict_mode sysctl parameter, i.e.: $ sysctl -wq net.vrf.strict_mode=1 Note that the same approach is used for the SRv6 End.DT4 Behavior and for the End.DT6 Behavior in VRF mode. The command used to instantiate an SRv6 End.DT46 Behavior is straightforward, i.e.: $ ip -6 route add 2001:db8::1 encap seg6local action End.DT46 vrftable 100 dev vrf100. [1] https://www.rfc-editor.org/rfc/rfc8986.html#name-enddt46-decapsulation-and-s ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Performance and impact of SRv6 End.DT46 Behavior on the SRv6 Networking ======================================================================= This patch aims to add the SRv6 End.DT46 Behavior with minimal impact on the performance of SRv6 End.DT4 and End.DT6 Behaviors. In order to verify this, we tested the performance of the newly introduced SRv6 End.DT46 Behavior and compared it with the performance of SRv6 End.DT{4,6} Behaviors, considering both the patched kernel and the kernel before applying the End.DT46 patch (referred to as vanilla kernel). In details, the following decapsulation scenarios were considered: 1.a) IPv6 traffic in SRv6 End.DT46 Behavior on patched kernel; 1.b) IPv4 traffic in SRv6 End.DT46 Behavior on patched kernel; 2.a) SRv6 End.DT6 Behavior (VRF mode) on patched kernel; 2.b) SRv6 End.DT4 Behavior on patched kernel; 3.a) SRv6 End.DT6 Behavior (VRF mode) on vanilla kernel (without the End.DT46 patch); 3.b) SRv6 End.DT4 Behavior on vanilla kernel (without the End.DT46 patch). All tests were performed on a testbed deployed on the CloudLab [2] facilities. We considered IPv{4,6} traffic handled by a single core (at 2.4 GHz on a Xeon(R) CPU E5-2630 v3) on kernel 5.13-rc1 using packets of size ~ 100 bytes. Scenario (1.a): average 684.70 kpps; std. dev. 0.7 kpps; Scenario (1.b): average 711.69 kpps; std. dev. 1.2 kpps; Scenario (2.a): average 690.70 kpps; std. dev. 1.2 kpps; Scenario (2.b): average 722.22 kpps; std. dev. 1.7 kpps; Scenario (3.a): average 690.02 kpps; std. dev. 2.6 kpps; Scenario (3.b): average 721.91 kpps; std. dev. 1.2 kpps; Considering the results for the patched kernel (1.a, 1.b, 2.a, 2.b) we observe that the performance degradation incurred in using End.DT46 rather than End.DT6 and End.DT4 respectively for IPv6 and IPv4 traffic is minimal, around 0.9% and 1.5%. Such very minimal performance degradation is the price to be paid if one prefers to use a single tunnel capable of handling both types of traffic (IPv4 and IPv6). Comparing the results for End.DT4 and End.DT6 under the patched and the vanilla kernel (2.a, 2.b, 3.a, 3.b) we observe that the introduction of the End.DT46 patch has no impact on the performance of End.DT4 and End.DT6. [2] https://www.cloudlab.us Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-17 20:16:44 +03:00
/* tunneled packet family (IPv4 or IPv6).
* Protocol and header length are inferred from family.
*/
seg6: add support for the SRv6 End.DT4 behavior SRv6 End.DT4 is defined in the SRv6 Network Programming [1]. The SRv6 End.DT4 is used to implement IPv4 L3VPN use-cases in multi-tenants environments. It decapsulates the received packets and it performs IPv4 routing lookup in the routing table of the tenant. The SRv6 End.DT4 Linux implementation leverages a VRF device in order to force the routing lookup into the associated routing table. To make the End.DT4 work properly, it must be guaranteed that the routing table used for routing lookup operations is bound to one and only one VRF during the tunnel creation. Such constraint has to be enforced by enabling the VRF strict_mode sysctl parameter, i.e: $ sysctl -wq net.vrf.strict_mode=1. At JANOG44, LINE corporation presented their multi-tenant DC architecture using SRv6 [2]. In the slides, they reported that the Linux kernel is missing the support of SRv6 End.DT4 behavior. The SRv6 End.DT4 behavior can be instantiated using a command similar to the following: $ ip route add 2001:db8::1 encap seg6local action End.DT4 vrftable 100 dev eth0 We introduce the "vrftable" extension in iproute2 in a following patch. [1] https://tools.ietf.org/html/draft-ietf-spring-srv6-network-programming [2] https://speakerdeck.com/line_developers/line-data-center-networking-with-srv6 Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:14 +03:00
u16 family;
};
seg6: add counters support for SRv6 Behaviors This patch provides counters for SRv6 Behaviors as defined in [1], section 6. For each SRv6 Behavior instance, counters defined in [1] are: - the total number of packets that have been correctly processed; - the total amount of traffic in bytes of all packets that have been correctly processed; In addition, this patch introduces a new counter that counts the number of packets that have NOT been properly processed (i.e. errors) by an SRv6 Behavior instance. Counters are not only interesting for network monitoring purposes (i.e. counting the number of packets processed by a given behavior) but they also provide a simple tool for checking whether a behavior instance is working as we expect or not. Counters can be useful for troubleshooting misconfigured SRv6 networks. Indeed, an SRv6 Behavior can silently drop packets for very different reasons (i.e. wrong SID configuration, interfaces set with SID addresses, etc) without any notification/message to the user. Due to the nature of SRv6 networks, diagnostic tools such as ping and traceroute may be ineffective: paths used for reaching a given router can be totally different from the ones followed by probe packets. In addition, paths are often asymmetrical and this makes it even more difficult to keep up with the journey of the packets and to understand which behaviors are actually processing our traffic. When counters are enabled on an SRv6 Behavior instance, it is possible to verify if packets are actually processed by such behavior and what is the outcome of the processing. Therefore, the counters for SRv6 Behaviors offer an non-invasive observability point which can be leveraged for both traffic monitoring and troubleshooting purposes. [1] https://www.rfc-editor.org/rfc/rfc8986.html#name-counters Troubleshooting using SRv6 Behavior counters -------------------------------------------- Let's make a brief example to see how helpful counters can be for SRv6 networks. Let's consider a node where an SRv6 End Behavior receives an SRv6 packet whose Segment Left (SL) is equal to 0. In this case, the End Behavior (which accepts only packets with SL >= 1) discards the packet and increases the error counter. This information can be leveraged by the network operator for troubleshooting. Indeed, the error counter is telling the user that the packet: (i) arrived at the node; (ii) the packet has been taken into account by the SRv6 End behavior; (iii) but an error has occurred during the processing. The error (iii) could be caused by different reasons, such as wrong route settings on the node or due to an invalid SID List carried by the SRv6 packet. Anyway, the error counter is used to exclude that the packet did not arrive at the node or it has not been processed by the behavior at all. Turning on/off counters for SRv6 Behaviors ------------------------------------------ Each SRv6 Behavior instance can be configured, at the time of its creation, to make use of counters. This is done through iproute2 which allows the user to create an SRv6 Behavior instance specifying the optional "count" attribute as shown in the following example: $ ip -6 route add 2001:db8::1 encap seg6local action End count dev eth0 per-behavior counters can be shown by adding "-s" to the iproute2 command line, i.e.: $ ip -s -6 route show 2001:db8::1 2001:db8::1 encap seg6local action End packets 0 bytes 0 errors 0 dev eth0 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Impact of counters for SRv6 Behaviors on performance ==================================================== To determine the performance impact due to the introduction of counters in the SRv6 Behavior subsystem, we have carried out extensive tests. We chose to test the throughput achieved by the SRv6 End.DX2 Behavior because, among all the other behaviors implemented so far, it reaches the highest throughput which is around 1.5 Mpps (per core at 2.4 GHz on a Xeon(R) CPU E5-2630 v3) on kernel 5.12-rc2 using packets of size ~ 100 bytes. Three different tests were conducted in order to evaluate the overall throughput of the SRv6 End.DX2 Behavior in the following scenarios: 1) vanilla kernel (without the SRv6 Behavior counters patch) and a single instance of an SRv6 End.DX2 Behavior; 2) patched kernel with SRv6 Behavior counters and a single instance of an SRv6 End.DX2 Behavior with counters turned off; 3) patched kernel with SRv6 Behavior counters and a single instance of SRv6 End.DX2 Behavior with counters turned on. All tests were performed on a testbed deployed on the CloudLab facilities [2], a flexible infrastructure dedicated to scientific research on the future of Cloud Computing. Results of tests are shown in the following table: Scenario (1): average 1504764,81 pps (~1504,76 kpps); std. dev 3956,82 pps Scenario (2): average 1501469,78 pps (~1501,47 kpps); std. dev 2979,85 pps Scenario (3): average 1501315,13 pps (~1501,32 kpps); std. dev 2956,00 pps As can be observed, throughputs achieved in scenarios (2),(3) did not suffer any observable degradation compared to scenario (1). Thanks to Jakub Kicinski and David Ahern for their valuable suggestions and comments provided during the discussion of the proposed RFCs. [2] https://www.cloudlab.us Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-04-27 18:44:04 +03:00
struct pcpu_seg6_local_counters {
u64_stats_t packets;
u64_stats_t bytes;
u64_stats_t errors;
struct u64_stats_sync syncp;
};
/* This struct groups all the SRv6 Behavior counters supported so far.
*
* put_nla_counters() makes use of this data structure to collect all counter
* values after the per-CPU counter evaluation has been performed.
* Finally, each counter value (in seg6_local_counters) is stored in the
* corresponding netlink attribute and sent to user space.
*
* NB: we don't want to expose this structure to user space!
*/
struct seg6_local_counters {
__u64 packets;
__u64 bytes;
__u64 errors;
};
#define seg6_local_alloc_pcpu_counters(__gfp) \
__netdev_alloc_pcpu_stats(struct pcpu_seg6_local_counters, \
((__gfp) | __GFP_ZERO))
#define SEG6_F_LOCAL_COUNTERS SEG6_F_ATTR(SEG6_LOCAL_COUNTERS)
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:26 +03:00
struct seg6_local_lwt {
int action;
struct ipv6_sr_hdr *srh;
int table;
struct in_addr nh4;
struct in6_addr nh6;
int iif;
int oif;
ipv6: sr: Add seg6local action End.BPF This patch adds the End.BPF action to the LWT seg6local infrastructure. This action works like any other seg6local End action, meaning that an IPv6 header with SRH is needed, whose DA has to be equal to the SID of the action. It will also advance the SRH to the next segment, the BPF program does not have to take care of this. Since the BPF program may not be a source of instability in the kernel, it is important to ensure that the integrity of the packet is maintained before yielding it back to the IPv6 layer. The hook hence keeps track if the SRH has been altered through the helpers, and re-validates its content if needed with seg6_validate_srh. The state kept for validation is stored in a per-CPU buffer. The BPF program is not allowed to directly write into the packet, and only some fields of the SRH can be altered through the helper bpf_lwt_seg6_store_bytes. Performances profiling has shown that the SRH re-validation does not induce a significant overhead. If the altered SRH is deemed as invalid, the packet is dropped. This validation is also done before executing any action through bpf_lwt_seg6_action, and will not be performed again if the SRH is not modified after calling the action. The BPF program may return 3 types of return codes: - BPF_OK: the End.BPF action will look up the next destination through seg6_lookup_nexthop. - BPF_REDIRECT: if an action has been executed through the bpf_lwt_seg6_action helper, the BPF program should return this value, as the skb's destination is already set and the default lookup should not be performed. - BPF_DROP : the packet will be dropped. Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-20 16:58:16 +03:00
struct bpf_lwt_prog bpf;
seg6: add support for the SRv6 End.DT4 behavior SRv6 End.DT4 is defined in the SRv6 Network Programming [1]. The SRv6 End.DT4 is used to implement IPv4 L3VPN use-cases in multi-tenants environments. It decapsulates the received packets and it performs IPv4 routing lookup in the routing table of the tenant. The SRv6 End.DT4 Linux implementation leverages a VRF device in order to force the routing lookup into the associated routing table. To make the End.DT4 work properly, it must be guaranteed that the routing table used for routing lookup operations is bound to one and only one VRF during the tunnel creation. Such constraint has to be enforced by enabling the VRF strict_mode sysctl parameter, i.e: $ sysctl -wq net.vrf.strict_mode=1. At JANOG44, LINE corporation presented their multi-tenant DC architecture using SRv6 [2]. In the slides, they reported that the Linux kernel is missing the support of SRv6 End.DT4 behavior. The SRv6 End.DT4 behavior can be instantiated using a command similar to the following: $ ip route add 2001:db8::1 encap seg6local action End.DT4 vrftable 100 dev eth0 We introduce the "vrftable" extension in iproute2 in a following patch. [1] https://tools.ietf.org/html/draft-ietf-spring-srv6-network-programming [2] https://speakerdeck.com/line_developers/line-data-center-networking-with-srv6 Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:14 +03:00
#ifdef CONFIG_NET_L3_MASTER_DEV
struct seg6_end_dt_info dt_info;
#endif
seg6: add NEXT-C-SID support for SRv6 End behavior The NEXT-C-SID mechanism described in [1] offers the possibility of encoding several SRv6 segments within a single 128 bit SID address. Such a SID address is called a Compressed SID (C-SID) container. In this way, the length of the SID List can be drastically reduced. A SID instantiated with the NEXT-C-SID flavor considers an IPv6 address logically structured in three main blocks: i) Locator-Block; ii) Locator-Node Function; iii) Argument. C-SID container +------------------------------------------------------------------+ | Locator-Block |Loc-Node| Argument | | |Function| | +------------------------------------------------------------------+ <--------- B -----------> <- NF -> <------------- A ---------------> (i) The Locator-Block can be any IPv6 prefix available to the provider; (ii) The Locator-Node Function represents the node and the function to be triggered when a packet is received on the node; (iii) The Argument carries the remaining C-SIDs in the current C-SID container. The NEXT-C-SID mechanism relies on the "flavors" framework defined in [2]. The flavors represent additional operations that can modify or extend a subset of the existing behaviors. This patch introduces the support for flavors in SRv6 End behavior implementing the NEXT-C-SID one. An SRv6 End behavior with NEXT-C-SID flavor works as an End behavior but it is capable of processing the compressed SID List encoded in C-SID containers. An SRv6 End behavior with NEXT-C-SID flavor can be configured to support user-provided Locator-Block and Locator-Node Function lengths. In this implementation, such lengths must be evenly divisible by 8 (i.e. must be byte-aligned), otherwise the kernel informs the user about invalid values with a meaningful error code and message through netlink_ext_ack. If Locator-Block and/or Locator-Node Function lengths are not provided by the user during configuration of an SRv6 End behavior instance with NEXT-C-SID flavor, the kernel will choose their default values i.e., 32-bit Locator-Block and 16-bit Locator-Node Function. [1] - https://datatracker.ietf.org/doc/html/draft-ietf-spring-srv6-srh-compression [2] - https://datatracker.ietf.org/doc/html/rfc8986 Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-09-12 20:16:18 +03:00
struct seg6_flavors_info flv_info;
seg6: add counters support for SRv6 Behaviors This patch provides counters for SRv6 Behaviors as defined in [1], section 6. For each SRv6 Behavior instance, counters defined in [1] are: - the total number of packets that have been correctly processed; - the total amount of traffic in bytes of all packets that have been correctly processed; In addition, this patch introduces a new counter that counts the number of packets that have NOT been properly processed (i.e. errors) by an SRv6 Behavior instance. Counters are not only interesting for network monitoring purposes (i.e. counting the number of packets processed by a given behavior) but they also provide a simple tool for checking whether a behavior instance is working as we expect or not. Counters can be useful for troubleshooting misconfigured SRv6 networks. Indeed, an SRv6 Behavior can silently drop packets for very different reasons (i.e. wrong SID configuration, interfaces set with SID addresses, etc) without any notification/message to the user. Due to the nature of SRv6 networks, diagnostic tools such as ping and traceroute may be ineffective: paths used for reaching a given router can be totally different from the ones followed by probe packets. In addition, paths are often asymmetrical and this makes it even more difficult to keep up with the journey of the packets and to understand which behaviors are actually processing our traffic. When counters are enabled on an SRv6 Behavior instance, it is possible to verify if packets are actually processed by such behavior and what is the outcome of the processing. Therefore, the counters for SRv6 Behaviors offer an non-invasive observability point which can be leveraged for both traffic monitoring and troubleshooting purposes. [1] https://www.rfc-editor.org/rfc/rfc8986.html#name-counters Troubleshooting using SRv6 Behavior counters -------------------------------------------- Let's make a brief example to see how helpful counters can be for SRv6 networks. Let's consider a node where an SRv6 End Behavior receives an SRv6 packet whose Segment Left (SL) is equal to 0. In this case, the End Behavior (which accepts only packets with SL >= 1) discards the packet and increases the error counter. This information can be leveraged by the network operator for troubleshooting. Indeed, the error counter is telling the user that the packet: (i) arrived at the node; (ii) the packet has been taken into account by the SRv6 End behavior; (iii) but an error has occurred during the processing. The error (iii) could be caused by different reasons, such as wrong route settings on the node or due to an invalid SID List carried by the SRv6 packet. Anyway, the error counter is used to exclude that the packet did not arrive at the node or it has not been processed by the behavior at all. Turning on/off counters for SRv6 Behaviors ------------------------------------------ Each SRv6 Behavior instance can be configured, at the time of its creation, to make use of counters. This is done through iproute2 which allows the user to create an SRv6 Behavior instance specifying the optional "count" attribute as shown in the following example: $ ip -6 route add 2001:db8::1 encap seg6local action End count dev eth0 per-behavior counters can be shown by adding "-s" to the iproute2 command line, i.e.: $ ip -s -6 route show 2001:db8::1 2001:db8::1 encap seg6local action End packets 0 bytes 0 errors 0 dev eth0 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Impact of counters for SRv6 Behaviors on performance ==================================================== To determine the performance impact due to the introduction of counters in the SRv6 Behavior subsystem, we have carried out extensive tests. We chose to test the throughput achieved by the SRv6 End.DX2 Behavior because, among all the other behaviors implemented so far, it reaches the highest throughput which is around 1.5 Mpps (per core at 2.4 GHz on a Xeon(R) CPU E5-2630 v3) on kernel 5.12-rc2 using packets of size ~ 100 bytes. Three different tests were conducted in order to evaluate the overall throughput of the SRv6 End.DX2 Behavior in the following scenarios: 1) vanilla kernel (without the SRv6 Behavior counters patch) and a single instance of an SRv6 End.DX2 Behavior; 2) patched kernel with SRv6 Behavior counters and a single instance of an SRv6 End.DX2 Behavior with counters turned off; 3) patched kernel with SRv6 Behavior counters and a single instance of SRv6 End.DX2 Behavior with counters turned on. All tests were performed on a testbed deployed on the CloudLab facilities [2], a flexible infrastructure dedicated to scientific research on the future of Cloud Computing. Results of tests are shown in the following table: Scenario (1): average 1504764,81 pps (~1504,76 kpps); std. dev 3956,82 pps Scenario (2): average 1501469,78 pps (~1501,47 kpps); std. dev 2979,85 pps Scenario (3): average 1501315,13 pps (~1501,32 kpps); std. dev 2956,00 pps As can be observed, throughputs achieved in scenarios (2),(3) did not suffer any observable degradation compared to scenario (1). Thanks to Jakub Kicinski and David Ahern for their valuable suggestions and comments provided during the discussion of the proposed RFCs. [2] https://www.cloudlab.us Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-04-27 18:44:04 +03:00
struct pcpu_seg6_local_counters __percpu *pcpu_counters;
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:26 +03:00
int headroom;
struct seg6_action_desc *desc;
seg6: add support for optional attributes in SRv6 behaviors Before this patch, each SRv6 behavior specifies a set of required attributes that must be provided by the userspace application when such behavior is going to be instantiated. If at least one of the required attributes is not provided, the creation of the behavior fails. The SRv6 behavior framework lacks a way to manage optional attributes. By definition, an optional attribute for a SRv6 behavior consists of an attribute which may or may not be provided by the userspace. Therefore, if an optional attribute is missing (and thus not supplied by the user) the creation of the behavior goes ahead without any issue. This patch explicitly differentiates the required attributes from the optional attributes. In particular, each behavior can declare a set of required attributes and a set of optional ones. The semantic of the required attributes remains *totally* unaffected by this patch. The introduction of the optional attributes does NOT impact on the backward compatibility of the existing SRv6 behaviors. It is essential to note that if an (optional or required) attribute is supplied to a SRv6 behavior which does not expect it, the behavior simply discards such attribute without generating any error or warning. This operating mode remained unchanged both before and after the introduction of the optional attributes extension. The optional attributes are one of the key components used to implement the SRv6 End.DT6 behavior based on the Virtual Routing and Forwarding (VRF) framework. The optional attributes make possible the coexistence of the already existing SRv6 End.DT6 implementation with the new SRv6 End.DT6 VRF-based implementation without breaking any backward compatibility. Further details on the SRv6 End.DT6 behavior (VRF mode) are reported in subsequent patches. From the userspace point of view, the support for optional attributes DO NOT require any changes to the userspace applications, i.e: iproute2 unless new attributes (required or optional) are needed. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:12 +03:00
/* unlike the required attrs, we have to track the optional attributes
* that have been effectively parsed.
*/
unsigned long parsed_optattrs;
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:26 +03:00
};
static struct seg6_local_lwt *seg6_local_lwtunnel(struct lwtunnel_state *lwt)
{
return (struct seg6_local_lwt *)lwt->data;
}
ipv6: sr: implement several seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END: regular SRH processing. The DA of the packet is updated to the next segment and forwarded accordingly. - SEG6_LOCAL_ACTION_END_X: same as above, except that the packet is forwarded to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_DX6: decapsulate the packet and forward to inner IPv6 packet to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_B6: insert the specified SRH directly after the IPv6 header of the packet. - SEG6_LOCAL_ACTION_END_B6_ENCAP: encapsulate the packet within an outer IPv6 header, containing the specified SRH. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:39:48 +03:00
static struct ipv6_sr_hdr *get_and_validate_srh(struct sk_buff *skb)
{
struct ipv6_sr_hdr *srh;
seg6: export get_srh() for ICMP handling An ICMP error message can contain in its message body part of an IPv6 packet which invoked the error. Such a packet might contain a segment router header. Export get_srh() so the ICMP code can make use of it. Since his changes the scope of the function from local to global, add the seg6_ prefix to keep the namespace clean. And move it into seg6.c so it is always available, not just when IPV6_SEG6_LWTUNNEL is enabled. Signed-off-by: Andrew Lunn <andrew@lunn.ch> Reviewed-by: David Ahern <dsahern@kernel.org> Reviewed-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-01-03 20:11:30 +03:00
srh = seg6_get_srh(skb, IP6_FH_F_SKIP_RH);
ipv6: sr: implement several seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END: regular SRH processing. The DA of the packet is updated to the next segment and forwarded accordingly. - SEG6_LOCAL_ACTION_END_X: same as above, except that the packet is forwarded to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_DX6: decapsulate the packet and forward to inner IPv6 packet to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_B6: insert the specified SRH directly after the IPv6 header of the packet. - SEG6_LOCAL_ACTION_END_B6_ENCAP: encapsulate the packet within an outer IPv6 header, containing the specified SRH. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:39:48 +03:00
if (!srh)
return NULL;
#ifdef CONFIG_IPV6_SEG6_HMAC
if (!seg6_hmac_validate_skb(skb))
return NULL;
#endif
return srh;
}
ipv6: sr: add helper functions for seg6local This patch adds three helper functions to be used with the seg6local packet processing actions. The decap_and_validate() function will be used by the End.D* actions, that decapsulate an SR-enabled packet. The advance_nextseg() function applies the fundamental operations to update an SRH for the next segment. The lookup_nexthop() function helps select the next-hop for the processed SR packets. It supports an optional next-hop address to route the packet specifically through it, and an optional routing table to use. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 10:56:47 +03:00
static bool decap_and_validate(struct sk_buff *skb, int proto)
{
struct ipv6_sr_hdr *srh;
unsigned int off = 0;
seg6: export get_srh() for ICMP handling An ICMP error message can contain in its message body part of an IPv6 packet which invoked the error. Such a packet might contain a segment router header. Export get_srh() so the ICMP code can make use of it. Since his changes the scope of the function from local to global, add the seg6_ prefix to keep the namespace clean. And move it into seg6.c so it is always available, not just when IPV6_SEG6_LWTUNNEL is enabled. Signed-off-by: Andrew Lunn <andrew@lunn.ch> Reviewed-by: David Ahern <dsahern@kernel.org> Reviewed-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-01-03 20:11:30 +03:00
srh = seg6_get_srh(skb, 0);
ipv6: sr: add helper functions for seg6local This patch adds three helper functions to be used with the seg6local packet processing actions. The decap_and_validate() function will be used by the End.D* actions, that decapsulate an SR-enabled packet. The advance_nextseg() function applies the fundamental operations to update an SRH for the next segment. The lookup_nexthop() function helps select the next-hop for the processed SR packets. It supports an optional next-hop address to route the packet specifically through it, and an optional routing table to use. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 10:56:47 +03:00
if (srh && srh->segments_left > 0)
return false;
#ifdef CONFIG_IPV6_SEG6_HMAC
if (srh && !seg6_hmac_validate_skb(skb))
return false;
#endif
if (ipv6_find_hdr(skb, &off, proto, NULL, NULL) < 0)
return false;
if (!pskb_pull(skb, off))
return false;
skb_postpull_rcsum(skb, skb_network_header(skb), off);
skb_reset_network_header(skb);
skb_reset_transport_header(skb);
ipv6: sr: remove SKB_GSO_IPXIP6 on End.D* actions After LRO/GRO is applied, SRv6 encapsulated packets have SKB_GSO_IPXIP6 feature flag, and this flag must be removed right after decapulation procedure. Currently, SKB_GSO_IPXIP6 flag is not removed on End.D* actions, which creates inconsistent packet state, that is, a normal TCP/IP packets have the SKB_GSO_IPXIP6 flag. This behavior can cause unexpected fallback to GSO on routing to netdevices that do not support SKB_GSO_IPXIP6. For example, on inter-VRF forwarding, decapsulated packets separated into small packets by GSO because VRF devices do not support TSO for packets with SKB_GSO_IPXIP6 flag, and this degrades forwarding performance. This patch removes encapsulation related GSO flags from the skb right after the End.D* action is applied. Fixes: d7a669dd2f8b ("ipv6: sr: add helper functions for seg6local") Signed-off-by: Yuki Taguchi <tagyounit@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-20 07:48:37 +03:00
if (iptunnel_pull_offloads(skb))
return false;
ipv6: sr: add helper functions for seg6local This patch adds three helper functions to be used with the seg6local packet processing actions. The decap_and_validate() function will be used by the End.D* actions, that decapsulate an SR-enabled packet. The advance_nextseg() function applies the fundamental operations to update an SRH for the next segment. The lookup_nexthop() function helps select the next-hop for the processed SR packets. It supports an optional next-hop address to route the packet specifically through it, and an optional routing table to use. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 10:56:47 +03:00
return true;
}
static void advance_nextseg(struct ipv6_sr_hdr *srh, struct in6_addr *daddr)
{
struct in6_addr *addr;
srh->segments_left--;
addr = srh->segments + srh->segments_left;
*daddr = *addr;
}
seg6: allow local packet processing for SRv6 End.DT6 behavior End.DT6 behavior makes use of seg6_lookup_nexthop() function which drops all packets that are destined to be locally processed. However, DT* should be able to deliver decapsulated packets that are destined to local addresses. Function seg6_lookup_nexthop() is also used by DX6, so in order to maintain compatibility I created another routing helper function which is called seg6_lookup_any_nexthop(). This function is able to take into account both packets that have to be processed locally and the ones that are destined to be forwarded directly to another machine. Hence, seg6_lookup_any_nexthop() is used in DT6 rather than seg6_lookup_nexthop() to allow local delivery. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-22 19:22:42 +03:00
static int
seg6_lookup_any_nexthop(struct sk_buff *skb, struct in6_addr *nhaddr,
u32 tbl_id, bool local_delivery)
ipv6: sr: add helper functions for seg6local This patch adds three helper functions to be used with the seg6local packet processing actions. The decap_and_validate() function will be used by the End.D* actions, that decapsulate an SR-enabled packet. The advance_nextseg() function applies the fundamental operations to update an SRH for the next segment. The lookup_nexthop() function helps select the next-hop for the processed SR packets. It supports an optional next-hop address to route the packet specifically through it, and an optional routing table to use. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 10:56:47 +03:00
{
struct net *net = dev_net(skb->dev);
struct ipv6hdr *hdr = ipv6_hdr(skb);
int flags = RT6_LOOKUP_F_HAS_SADDR;
struct dst_entry *dst = NULL;
struct rt6_info *rt;
struct flowi6 fl6;
seg6: allow local packet processing for SRv6 End.DT6 behavior End.DT6 behavior makes use of seg6_lookup_nexthop() function which drops all packets that are destined to be locally processed. However, DT* should be able to deliver decapsulated packets that are destined to local addresses. Function seg6_lookup_nexthop() is also used by DX6, so in order to maintain compatibility I created another routing helper function which is called seg6_lookup_any_nexthop(). This function is able to take into account both packets that have to be processed locally and the ones that are destined to be forwarded directly to another machine. Hence, seg6_lookup_any_nexthop() is used in DT6 rather than seg6_lookup_nexthop() to allow local delivery. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-22 19:22:42 +03:00
int dev_flags = 0;
ipv6: sr: add helper functions for seg6local This patch adds three helper functions to be used with the seg6local packet processing actions. The decap_and_validate() function will be used by the End.D* actions, that decapsulate an SR-enabled packet. The advance_nextseg() function applies the fundamental operations to update an SRH for the next segment. The lookup_nexthop() function helps select the next-hop for the processed SR packets. It supports an optional next-hop address to route the packet specifically through it, and an optional routing table to use. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 10:56:47 +03:00
net: seg6: fix seg6_lookup_any_nexthop() to handle VRFs using flowi_l3mdev Commit 40867d74c374 ("net: Add l3mdev index to flow struct and avoid oif reset for port devices") adds a new entry (flowi_l3mdev) in the common flow struct used for indicating the l3mdev index for later rule and table matching. The l3mdev_update_flow() has been adapted to properly set the flowi_l3mdev based on the flowi_oif/flowi_iif. In fact, when a valid flowi_iif is supplied to the l3mdev_update_flow(), this function can update the flowi_l3mdev entry only if it has not yet been set (i.e., the flowi_l3mdev entry is equal to 0). The SRv6 End.DT6 behavior in VRF mode leverages a VRF device in order to force the routing lookup into the associated routing table. This routing operation is performed by seg6_lookup_any_nextop() preparing a flowi6 data structure used by ip6_route_input_lookup() which, in turn, (indirectly) invokes l3mdev_update_flow(). However, seg6_lookup_any_nexthop() does not initialize the new flowi_l3mdev entry which is filled with random garbage data. This prevents l3mdev_update_flow() from properly updating the flowi_l3mdev with the VRF index, and thus SRv6 End.DT6 (VRF mode)/DT46 behaviors are broken. This patch correctly initializes the flowi6 instance allocated and used by seg6_lookup_any_nexhtop(). Specifically, the entire flowi6 instance is wiped out: in case new entries are added to flowi/flowi6 (as happened with the flowi_l3mdev entry), we should no longer have incorrectly initialized values. As a result of this operation, the value of flowi_l3mdev is also set to 0. The proposed fix can be tested easily. Starting from the commit referenced in the Fixes, selftests [1],[2] indicate that the SRv6 End.DT6 (VRF mode)/DT46 behaviors no longer work correctly. By applying this patch, those behaviors are back to work properly again. [1] - tools/testing/selftests/net/srv6_end_dt46_l3vpn_test.sh [2] - tools/testing/selftests/net/srv6_end_dt6_l3vpn_test.sh Fixes: 40867d74c374 ("net: Add l3mdev index to flow struct and avoid oif reset for port devices") Reported-by: Anton Makarov <am@3a-alliance.com> Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/r/20220608091917.20345-1-andrea.mayer@uniroma2.it Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-06-08 12:19:17 +03:00
memset(&fl6, 0, sizeof(fl6));
ipv6: sr: add helper functions for seg6local This patch adds three helper functions to be used with the seg6local packet processing actions. The decap_and_validate() function will be used by the End.D* actions, that decapsulate an SR-enabled packet. The advance_nextseg() function applies the fundamental operations to update an SRH for the next segment. The lookup_nexthop() function helps select the next-hop for the processed SR packets. It supports an optional next-hop address to route the packet specifically through it, and an optional routing table to use. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 10:56:47 +03:00
fl6.flowi6_iif = skb->dev->ifindex;
fl6.daddr = nhaddr ? *nhaddr : hdr->daddr;
fl6.saddr = hdr->saddr;
fl6.flowlabel = ip6_flowinfo(hdr);
fl6.flowi6_mark = skb->mark;
fl6.flowi6_proto = hdr->nexthdr;
if (nhaddr)
fl6.flowi6_flags = FLOWI_FLAG_KNOWN_NH;
if (!tbl_id) {
net/ipv6: Pass skb to route lookup IPv6 does path selection for multipath routes deep in the lookup functions. The next patch adds L4 hash option and needs the skb for the forward path. To get the skb to the relevant FIB lookup functions it needs to go through the fib rules layer, so add a lookup_data argument to the fib_lookup_arg struct. Signed-off-by: David Ahern <dsahern@gmail.com> Reviewed-by: Ido Schimmel <idosch@mellanox.com> Reviewed-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-02 19:32:17 +03:00
dst = ip6_route_input_lookup(net, skb->dev, &fl6, skb, flags);
ipv6: sr: add helper functions for seg6local This patch adds three helper functions to be used with the seg6local packet processing actions. The decap_and_validate() function will be used by the End.D* actions, that decapsulate an SR-enabled packet. The advance_nextseg() function applies the fundamental operations to update an SRH for the next segment. The lookup_nexthop() function helps select the next-hop for the processed SR packets. It supports an optional next-hop address to route the packet specifically through it, and an optional routing table to use. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 10:56:47 +03:00
} else {
struct fib6_table *table;
table = fib6_get_table(net, tbl_id);
if (!table)
goto out;
net/ipv6: Pass skb to route lookup IPv6 does path selection for multipath routes deep in the lookup functions. The next patch adds L4 hash option and needs the skb for the forward path. To get the skb to the relevant FIB lookup functions it needs to go through the fib rules layer, so add a lookup_data argument to the fib_lookup_arg struct. Signed-off-by: David Ahern <dsahern@gmail.com> Reviewed-by: Ido Schimmel <idosch@mellanox.com> Reviewed-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-02 19:32:17 +03:00
rt = ip6_pol_route(net, table, 0, &fl6, skb, flags);
ipv6: sr: add helper functions for seg6local This patch adds three helper functions to be used with the seg6local packet processing actions. The decap_and_validate() function will be used by the End.D* actions, that decapsulate an SR-enabled packet. The advance_nextseg() function applies the fundamental operations to update an SRH for the next segment. The lookup_nexthop() function helps select the next-hop for the processed SR packets. It supports an optional next-hop address to route the packet specifically through it, and an optional routing table to use. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 10:56:47 +03:00
dst = &rt->dst;
}
seg6: allow local packet processing for SRv6 End.DT6 behavior End.DT6 behavior makes use of seg6_lookup_nexthop() function which drops all packets that are destined to be locally processed. However, DT* should be able to deliver decapsulated packets that are destined to local addresses. Function seg6_lookup_nexthop() is also used by DX6, so in order to maintain compatibility I created another routing helper function which is called seg6_lookup_any_nexthop(). This function is able to take into account both packets that have to be processed locally and the ones that are destined to be forwarded directly to another machine. Hence, seg6_lookup_any_nexthop() is used in DT6 rather than seg6_lookup_nexthop() to allow local delivery. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-22 19:22:42 +03:00
/* we want to discard traffic destined for local packet processing,
* if @local_delivery is set to false.
*/
if (!local_delivery)
dev_flags |= IFF_LOOPBACK;
if (dst && (dst->dev->flags & dev_flags) && !dst->error) {
ipv6: sr: add helper functions for seg6local This patch adds three helper functions to be used with the seg6local packet processing actions. The decap_and_validate() function will be used by the End.D* actions, that decapsulate an SR-enabled packet. The advance_nextseg() function applies the fundamental operations to update an SRH for the next segment. The lookup_nexthop() function helps select the next-hop for the processed SR packets. It supports an optional next-hop address to route the packet specifically through it, and an optional routing table to use. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 10:56:47 +03:00
dst_release(dst);
dst = NULL;
}
out:
if (!dst) {
rt = net->ipv6.ip6_blk_hole_entry;
dst = &rt->dst;
dst_hold(dst);
}
skb_dst_drop(skb);
skb_dst_set(skb, dst);
ipv6: sr: export function lookup_nexthop The function lookup_nexthop is essential to implement most of the seg6local actions. As we want to provide a BPF helper allowing to apply some of these actions on the packet being processed, the helper should be able to call this function, hence the need to make it public. Moreover, if one argument is incorrect or if the next hop can not be found, an error should be returned by the BPF helper so the BPF program can adapt its processing of the packet (return an error, properly force the drop, ...). This patch hence makes this function return dst->error to indicate a possible error. Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-20 16:58:13 +03:00
return dst->error;
ipv6: sr: add helper functions for seg6local This patch adds three helper functions to be used with the seg6local packet processing actions. The decap_and_validate() function will be used by the End.D* actions, that decapsulate an SR-enabled packet. The advance_nextseg() function applies the fundamental operations to update an SRH for the next segment. The lookup_nexthop() function helps select the next-hop for the processed SR packets. It supports an optional next-hop address to route the packet specifically through it, and an optional routing table to use. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 10:56:47 +03:00
}
seg6: allow local packet processing for SRv6 End.DT6 behavior End.DT6 behavior makes use of seg6_lookup_nexthop() function which drops all packets that are destined to be locally processed. However, DT* should be able to deliver decapsulated packets that are destined to local addresses. Function seg6_lookup_nexthop() is also used by DX6, so in order to maintain compatibility I created another routing helper function which is called seg6_lookup_any_nexthop(). This function is able to take into account both packets that have to be processed locally and the ones that are destined to be forwarded directly to another machine. Hence, seg6_lookup_any_nexthop() is used in DT6 rather than seg6_lookup_nexthop() to allow local delivery. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-22 19:22:42 +03:00
int seg6_lookup_nexthop(struct sk_buff *skb,
struct in6_addr *nhaddr, u32 tbl_id)
{
return seg6_lookup_any_nexthop(skb, nhaddr, tbl_id, false);
}
seg6: add NEXT-C-SID support for SRv6 End behavior The NEXT-C-SID mechanism described in [1] offers the possibility of encoding several SRv6 segments within a single 128 bit SID address. Such a SID address is called a Compressed SID (C-SID) container. In this way, the length of the SID List can be drastically reduced. A SID instantiated with the NEXT-C-SID flavor considers an IPv6 address logically structured in three main blocks: i) Locator-Block; ii) Locator-Node Function; iii) Argument. C-SID container +------------------------------------------------------------------+ | Locator-Block |Loc-Node| Argument | | |Function| | +------------------------------------------------------------------+ <--------- B -----------> <- NF -> <------------- A ---------------> (i) The Locator-Block can be any IPv6 prefix available to the provider; (ii) The Locator-Node Function represents the node and the function to be triggered when a packet is received on the node; (iii) The Argument carries the remaining C-SIDs in the current C-SID container. The NEXT-C-SID mechanism relies on the "flavors" framework defined in [2]. The flavors represent additional operations that can modify or extend a subset of the existing behaviors. This patch introduces the support for flavors in SRv6 End behavior implementing the NEXT-C-SID one. An SRv6 End behavior with NEXT-C-SID flavor works as an End behavior but it is capable of processing the compressed SID List encoded in C-SID containers. An SRv6 End behavior with NEXT-C-SID flavor can be configured to support user-provided Locator-Block and Locator-Node Function lengths. In this implementation, such lengths must be evenly divisible by 8 (i.e. must be byte-aligned), otherwise the kernel informs the user about invalid values with a meaningful error code and message through netlink_ext_ack. If Locator-Block and/or Locator-Node Function lengths are not provided by the user during configuration of an SRv6 End behavior instance with NEXT-C-SID flavor, the kernel will choose their default values i.e., 32-bit Locator-Block and 16-bit Locator-Node Function. [1] - https://datatracker.ietf.org/doc/html/draft-ietf-spring-srv6-srh-compression [2] - https://datatracker.ietf.org/doc/html/rfc8986 Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-09-12 20:16:18 +03:00
static __u8 seg6_flv_lcblock_octects(const struct seg6_flavors_info *finfo)
{
return finfo->lcblock_bits >> 3;
}
static __u8 seg6_flv_lcnode_func_octects(const struct seg6_flavors_info *finfo)
{
return finfo->lcnode_func_bits >> 3;
}
static bool seg6_next_csid_is_arg_zero(const struct in6_addr *addr,
const struct seg6_flavors_info *finfo)
{
__u8 fnc_octects = seg6_flv_lcnode_func_octects(finfo);
__u8 blk_octects = seg6_flv_lcblock_octects(finfo);
__u8 arg_octects;
int i;
arg_octects = 16 - blk_octects - fnc_octects;
for (i = 0; i < arg_octects; ++i) {
if (addr->s6_addr[blk_octects + fnc_octects + i] != 0x00)
return false;
}
return true;
}
/* assume that DA.Argument length > 0 */
static void seg6_next_csid_advance_arg(struct in6_addr *addr,
const struct seg6_flavors_info *finfo)
{
__u8 fnc_octects = seg6_flv_lcnode_func_octects(finfo);
__u8 blk_octects = seg6_flv_lcblock_octects(finfo);
/* advance DA.Argument */
memmove(&addr->s6_addr[blk_octects],
&addr->s6_addr[blk_octects + fnc_octects],
16 - blk_octects - fnc_octects);
memset(&addr->s6_addr[16 - fnc_octects], 0x00, fnc_octects);
}
seg6: factor out End lookup nexthop processing to a dedicated function The End nexthop lookup/input operations are moved into a new helper function named input_action_end_finish(). This avoids duplicating the code needed to compute the nexthop in the different flavors of the End behavior. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2023-02-15 16:46:57 +03:00
static int input_action_end_finish(struct sk_buff *skb,
struct seg6_local_lwt *slwt)
{
seg6_lookup_nexthop(skb, NULL, 0);
return dst_input(skb);
}
seg6: add NEXT-C-SID support for SRv6 End behavior The NEXT-C-SID mechanism described in [1] offers the possibility of encoding several SRv6 segments within a single 128 bit SID address. Such a SID address is called a Compressed SID (C-SID) container. In this way, the length of the SID List can be drastically reduced. A SID instantiated with the NEXT-C-SID flavor considers an IPv6 address logically structured in three main blocks: i) Locator-Block; ii) Locator-Node Function; iii) Argument. C-SID container +------------------------------------------------------------------+ | Locator-Block |Loc-Node| Argument | | |Function| | +------------------------------------------------------------------+ <--------- B -----------> <- NF -> <------------- A ---------------> (i) The Locator-Block can be any IPv6 prefix available to the provider; (ii) The Locator-Node Function represents the node and the function to be triggered when a packet is received on the node; (iii) The Argument carries the remaining C-SIDs in the current C-SID container. The NEXT-C-SID mechanism relies on the "flavors" framework defined in [2]. The flavors represent additional operations that can modify or extend a subset of the existing behaviors. This patch introduces the support for flavors in SRv6 End behavior implementing the NEXT-C-SID one. An SRv6 End behavior with NEXT-C-SID flavor works as an End behavior but it is capable of processing the compressed SID List encoded in C-SID containers. An SRv6 End behavior with NEXT-C-SID flavor can be configured to support user-provided Locator-Block and Locator-Node Function lengths. In this implementation, such lengths must be evenly divisible by 8 (i.e. must be byte-aligned), otherwise the kernel informs the user about invalid values with a meaningful error code and message through netlink_ext_ack. If Locator-Block and/or Locator-Node Function lengths are not provided by the user during configuration of an SRv6 End behavior instance with NEXT-C-SID flavor, the kernel will choose their default values i.e., 32-bit Locator-Block and 16-bit Locator-Node Function. [1] - https://datatracker.ietf.org/doc/html/draft-ietf-spring-srv6-srh-compression [2] - https://datatracker.ietf.org/doc/html/rfc8986 Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-09-12 20:16:18 +03:00
static int input_action_end_core(struct sk_buff *skb,
struct seg6_local_lwt *slwt)
ipv6: sr: implement several seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END: regular SRH processing. The DA of the packet is updated to the next segment and forwarded accordingly. - SEG6_LOCAL_ACTION_END_X: same as above, except that the packet is forwarded to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_DX6: decapsulate the packet and forward to inner IPv6 packet to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_B6: insert the specified SRH directly after the IPv6 header of the packet. - SEG6_LOCAL_ACTION_END_B6_ENCAP: encapsulate the packet within an outer IPv6 header, containing the specified SRH. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:39:48 +03:00
{
struct ipv6_sr_hdr *srh;
srh = get_and_validate_srh(skb);
if (!srh)
goto drop;
ipv6: sr: add helper functions for seg6local This patch adds three helper functions to be used with the seg6local packet processing actions. The decap_and_validate() function will be used by the End.D* actions, that decapsulate an SR-enabled packet. The advance_nextseg() function applies the fundamental operations to update an SRH for the next segment. The lookup_nexthop() function helps select the next-hop for the processed SR packets. It supports an optional next-hop address to route the packet specifically through it, and an optional routing table to use. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 10:56:47 +03:00
advance_nextseg(srh, &ipv6_hdr(skb)->daddr);
ipv6: sr: implement several seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END: regular SRH processing. The DA of the packet is updated to the next segment and forwarded accordingly. - SEG6_LOCAL_ACTION_END_X: same as above, except that the packet is forwarded to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_DX6: decapsulate the packet and forward to inner IPv6 packet to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_B6: insert the specified SRH directly after the IPv6 header of the packet. - SEG6_LOCAL_ACTION_END_B6_ENCAP: encapsulate the packet within an outer IPv6 header, containing the specified SRH. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:39:48 +03:00
seg6: factor out End lookup nexthop processing to a dedicated function The End nexthop lookup/input operations are moved into a new helper function named input_action_end_finish(). This avoids duplicating the code needed to compute the nexthop in the different flavors of the End behavior. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2023-02-15 16:46:57 +03:00
return input_action_end_finish(skb, slwt);
ipv6: sr: implement several seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END: regular SRH processing. The DA of the packet is updated to the next segment and forwarded accordingly. - SEG6_LOCAL_ACTION_END_X: same as above, except that the packet is forwarded to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_DX6: decapsulate the packet and forward to inner IPv6 packet to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_B6: insert the specified SRH directly after the IPv6 header of the packet. - SEG6_LOCAL_ACTION_END_B6_ENCAP: encapsulate the packet within an outer IPv6 header, containing the specified SRH. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:39:48 +03:00
drop:
kfree_skb(skb);
return -EINVAL;
}
seg6: add NEXT-C-SID support for SRv6 End behavior The NEXT-C-SID mechanism described in [1] offers the possibility of encoding several SRv6 segments within a single 128 bit SID address. Such a SID address is called a Compressed SID (C-SID) container. In this way, the length of the SID List can be drastically reduced. A SID instantiated with the NEXT-C-SID flavor considers an IPv6 address logically structured in three main blocks: i) Locator-Block; ii) Locator-Node Function; iii) Argument. C-SID container +------------------------------------------------------------------+ | Locator-Block |Loc-Node| Argument | | |Function| | +------------------------------------------------------------------+ <--------- B -----------> <- NF -> <------------- A ---------------> (i) The Locator-Block can be any IPv6 prefix available to the provider; (ii) The Locator-Node Function represents the node and the function to be triggered when a packet is received on the node; (iii) The Argument carries the remaining C-SIDs in the current C-SID container. The NEXT-C-SID mechanism relies on the "flavors" framework defined in [2]. The flavors represent additional operations that can modify or extend a subset of the existing behaviors. This patch introduces the support for flavors in SRv6 End behavior implementing the NEXT-C-SID one. An SRv6 End behavior with NEXT-C-SID flavor works as an End behavior but it is capable of processing the compressed SID List encoded in C-SID containers. An SRv6 End behavior with NEXT-C-SID flavor can be configured to support user-provided Locator-Block and Locator-Node Function lengths. In this implementation, such lengths must be evenly divisible by 8 (i.e. must be byte-aligned), otherwise the kernel informs the user about invalid values with a meaningful error code and message through netlink_ext_ack. If Locator-Block and/or Locator-Node Function lengths are not provided by the user during configuration of an SRv6 End behavior instance with NEXT-C-SID flavor, the kernel will choose their default values i.e., 32-bit Locator-Block and 16-bit Locator-Node Function. [1] - https://datatracker.ietf.org/doc/html/draft-ietf-spring-srv6-srh-compression [2] - https://datatracker.ietf.org/doc/html/rfc8986 Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-09-12 20:16:18 +03:00
static int end_next_csid_core(struct sk_buff *skb, struct seg6_local_lwt *slwt)
{
const struct seg6_flavors_info *finfo = &slwt->flv_info;
struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
if (seg6_next_csid_is_arg_zero(daddr, finfo))
return input_action_end_core(skb, slwt);
/* update DA */
seg6_next_csid_advance_arg(daddr, finfo);
seg6: factor out End lookup nexthop processing to a dedicated function The End nexthop lookup/input operations are moved into a new helper function named input_action_end_finish(). This avoids duplicating the code needed to compute the nexthop in the different flavors of the End behavior. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2023-02-15 16:46:57 +03:00
return input_action_end_finish(skb, slwt);
seg6: add NEXT-C-SID support for SRv6 End behavior The NEXT-C-SID mechanism described in [1] offers the possibility of encoding several SRv6 segments within a single 128 bit SID address. Such a SID address is called a Compressed SID (C-SID) container. In this way, the length of the SID List can be drastically reduced. A SID instantiated with the NEXT-C-SID flavor considers an IPv6 address logically structured in three main blocks: i) Locator-Block; ii) Locator-Node Function; iii) Argument. C-SID container +------------------------------------------------------------------+ | Locator-Block |Loc-Node| Argument | | |Function| | +------------------------------------------------------------------+ <--------- B -----------> <- NF -> <------------- A ---------------> (i) The Locator-Block can be any IPv6 prefix available to the provider; (ii) The Locator-Node Function represents the node and the function to be triggered when a packet is received on the node; (iii) The Argument carries the remaining C-SIDs in the current C-SID container. The NEXT-C-SID mechanism relies on the "flavors" framework defined in [2]. The flavors represent additional operations that can modify or extend a subset of the existing behaviors. This patch introduces the support for flavors in SRv6 End behavior implementing the NEXT-C-SID one. An SRv6 End behavior with NEXT-C-SID flavor works as an End behavior but it is capable of processing the compressed SID List encoded in C-SID containers. An SRv6 End behavior with NEXT-C-SID flavor can be configured to support user-provided Locator-Block and Locator-Node Function lengths. In this implementation, such lengths must be evenly divisible by 8 (i.e. must be byte-aligned), otherwise the kernel informs the user about invalid values with a meaningful error code and message through netlink_ext_ack. If Locator-Block and/or Locator-Node Function lengths are not provided by the user during configuration of an SRv6 End behavior instance with NEXT-C-SID flavor, the kernel will choose their default values i.e., 32-bit Locator-Block and 16-bit Locator-Node Function. [1] - https://datatracker.ietf.org/doc/html/draft-ietf-spring-srv6-srh-compression [2] - https://datatracker.ietf.org/doc/html/rfc8986 Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-09-12 20:16:18 +03:00
}
static bool seg6_next_csid_enabled(__u32 fops)
{
return fops & BIT(SEG6_LOCAL_FLV_OP_NEXT_CSID);
}
seg6: add PSP flavor support for SRv6 End behavior The "flavors" framework defined in RFC8986 [1] represents additional operations that can modify or extend a subset of existing behaviors such as SRv6 End, End.X and End.T. We report these flavors hereafter: - Penultimate Segment Pop (PSP); - Ultimate Segment Pop (USP); - Ultimate Segment Decapsulation (USD). Depending on how the Segment Routing Header (SRH) has to be handled, an SRv6 End* behavior can support these flavors either individually or in combinations. In this patch, we only consider the PSP flavor for the SRv6 End behavior. A PSP enabled SRv6 End behavior is used by the Source/Ingress SR node (i.e., the one applying the SRv6 Policy) when it needs to instruct the penultimate SR Endpoint node listed in the SID List (carried by the SRH) to remove the SRH from the IPv6 header. Specifically, a PSP enabled SRv6 End behavior processes the SRH by: i) decreasing the Segment Left (SL) from 1 to 0; ii) copying the Last Segment IDentifier (SID) into the IPv6 Destination Address (DA); iii) removing (i.e., popping) the outer SRH from the extension headers following the IPv6 header. It is important to note that PSP operation (steps i, ii, iii) takes place only at a penultimate SR Segment Endpoint node (i.e., when the SL=1) and does not happen at non-penultimate Endpoint nodes. Indeed, when a SID of PSP flavor is processed at a non-penultimate SR Segment Endpoint node, the PSP operation is not performed because it would not be possible to decrease the SL from 1 to 0. SL=2 SL=1 SL=0 | | | For example, given the SRv6 policy (SID List := < X, Y, Z >): - a PSP enabled SRv6 End behavior bound to SID "Y" will apply the PSP operation as Segment Left (SL) is 1, corresponding to the Penultimate Segment of the SID List; - a PSP enabled SRv6 End behavior bound to SID "X" will *NOT* apply the PSP operation as the Segment Left is 2. This behavior instance will apply the "standard" End packet processing, ignoring the configured PSP flavor at all. [1] - RFC8986: https://datatracker.ietf.org/doc/html/rfc8986 Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2023-02-15 16:46:58 +03:00
/* We describe the packet state in relation to the absence/presence of the SRH
* and the Segment Left (SL) field.
* For our purposes, it is not necessary to record the exact value of the SL
* when the SID List consists of two or more segments.
*/
enum seg6_local_pktinfo {
/* the order really matters! */
SEG6_LOCAL_PKTINFO_NOHDR = 0,
SEG6_LOCAL_PKTINFO_SL_ZERO,
SEG6_LOCAL_PKTINFO_SL_ONE,
SEG6_LOCAL_PKTINFO_SL_MORE,
__SEG6_LOCAL_PKTINFO_MAX,
};
#define SEG6_LOCAL_PKTINFO_MAX (__SEG6_LOCAL_PKTINFO_MAX - 1)
static enum seg6_local_pktinfo seg6_get_srh_pktinfo(struct ipv6_sr_hdr *srh)
{
__u8 sgl;
if (!srh)
return SEG6_LOCAL_PKTINFO_NOHDR;
sgl = srh->segments_left;
if (sgl < 2)
return SEG6_LOCAL_PKTINFO_SL_ZERO + sgl;
return SEG6_LOCAL_PKTINFO_SL_MORE;
}
enum seg6_local_flv_action {
SEG6_LOCAL_FLV_ACT_UNSPEC = 0,
SEG6_LOCAL_FLV_ACT_END,
SEG6_LOCAL_FLV_ACT_PSP,
SEG6_LOCAL_FLV_ACT_USP,
SEG6_LOCAL_FLV_ACT_USD,
__SEG6_LOCAL_FLV_ACT_MAX
};
#define SEG6_LOCAL_FLV_ACT_MAX (__SEG6_LOCAL_FLV_ACT_MAX - 1)
/* The action table for RFC8986 flavors (see the flv8986_act_tbl below)
* contains the actions (i.e. processing operations) to be applied on packets
* when flavors are configured for an End* behavior.
* By combining the pkinfo data and from the flavors mask, the macro
* computes the index used to access the elements (actions) stored in the
* action table. The index is structured as follows:
*
* index
* _______________/\________________
* / \
* +----------------+----------------+
* | pf | afm |
* +----------------+----------------+
* ph-1 ... p1 p0 fk-1 ... f1 f0
* MSB LSB
*
* where:
* - 'afm' (adjusted flavor mask) is the mask containing a combination of the
* RFC8986 flavors currently supported. 'afm' corresponds to the @fm
* argument of the macro whose value is righ-shifted by 1 bit. By doing so,
* we discard the SEG6_LOCAL_FLV_OP_UNSPEC flag (bit 0 in @fm) which is
* never used here;
* - 'pf' encodes the packet info (pktinfo) regarding the presence/absence of
* the SRH, SL = 0, etc. 'pf' is set with the value of @pf provided as
* argument to the macro.
*/
#define flv8986_act_tbl_idx(pf, fm) \
((((pf) << bits_per(SEG6_LOCAL_FLV8986_SUPP_OPS)) | \
((fm) & SEG6_LOCAL_FLV8986_SUPP_OPS)) >> SEG6_LOCAL_FLV_OP_PSP)
/* We compute the size of the action table by considering the RFC8986 flavors
* actually supported by the kernel. In this way, the size is automatically
* adjusted when new flavors are supported.
*/
#define FLV8986_ACT_TBL_SIZE \
roundup_pow_of_two(flv8986_act_tbl_idx(SEG6_LOCAL_PKTINFO_MAX, \
SEG6_LOCAL_FLV8986_SUPP_OPS))
/* tbl_cfg(act, pf, fm) macro is used to easily configure the action
* table; it accepts 3 arguments:
* i) @act, the suffix from SEG6_LOCAL_FLV_ACT_{act} representing
* the action that should be applied on the packet;
* ii) @pf, the suffix from SEG6_LOCAL_PKTINFO_{pf} reporting the packet
* info about the lack/presence of SRH, SRH with SL = 0, etc;
* iii) @fm, the mask of flavors.
*/
#define tbl_cfg(act, pf, fm) \
[flv8986_act_tbl_idx(SEG6_LOCAL_PKTINFO_##pf, \
(fm))] = SEG6_LOCAL_FLV_ACT_##act
/* shorthand for improving readability */
#define F_PSP SEG6_F_LOCAL_FLV_PSP
/* The table contains, for each combination of the pktinfo data and
* flavors, the action that should be taken on a packet (e.g.
* "standard" Endpoint processing, Penultimate Segment Pop, etc).
*
* By default, table entries not explicitly configured are initialized with the
* SEG6_LOCAL_FLV_ACT_UNSPEC action, which generally has the effect of
* discarding the processed packet.
*/
static const u8 flv8986_act_tbl[FLV8986_ACT_TBL_SIZE] = {
/* PSP variant for packet where SRH with SL = 1 */
tbl_cfg(PSP, SL_ONE, F_PSP),
/* End for packet where the SRH with SL > 1*/
tbl_cfg(END, SL_MORE, F_PSP),
};
#undef F_PSP
#undef tbl_cfg
/* For each flavor defined in RFC8986 (or a combination of them) an action is
* performed on the packet. The specific action depends on:
* - info extracted from the packet (i.e. pktinfo data) regarding the
* lack/presence of the SRH, and if the SRH is available, on the value of
* Segment Left field;
* - the mask of flavors configured for the specific SRv6 End* behavior.
*
* The function combines both the pkinfo and the flavors mask to evaluate the
* corresponding action to be taken on the packet.
*/
static enum seg6_local_flv_action
seg6_local_flv8986_act_lookup(enum seg6_local_pktinfo pinfo, __u32 flvmask)
{
unsigned long index;
/* check if the provided mask of flavors is supported */
if (unlikely(flvmask & ~SEG6_LOCAL_FLV8986_SUPP_OPS))
return SEG6_LOCAL_FLV_ACT_UNSPEC;
index = flv8986_act_tbl_idx(pinfo, flvmask);
if (unlikely(index >= FLV8986_ACT_TBL_SIZE))
return SEG6_LOCAL_FLV_ACT_UNSPEC;
return flv8986_act_tbl[index];
}
/* skb->data must be aligned with skb->network_header */
static bool seg6_pop_srh(struct sk_buff *skb, int srhoff)
{
struct ipv6_sr_hdr *srh;
struct ipv6hdr *iph;
__u8 srh_nexthdr;
int thoff = -1;
int srhlen;
int nhlen;
if (unlikely(srhoff < sizeof(*iph) ||
!pskb_may_pull(skb, srhoff + sizeof(*srh))))
return false;
srh = (struct ipv6_sr_hdr *)(skb->data + srhoff);
srhlen = ipv6_optlen(srh);
/* we are about to mangle the pkt, let's check if we can write on it */
if (unlikely(skb_ensure_writable(skb, srhoff + srhlen)))
return false;
/* skb_ensure_writable() may change skb pointers; evaluate srh again */
srh = (struct ipv6_sr_hdr *)(skb->data + srhoff);
srh_nexthdr = srh->nexthdr;
if (unlikely(!skb_transport_header_was_set(skb)))
goto pull;
nhlen = skb_network_header_len(skb);
/* we have to deal with the transport header: it could be set before
* the SRH, after the SRH, or within it (which is considered wrong,
* however).
*/
if (likely(nhlen <= srhoff))
thoff = nhlen;
else if (nhlen >= srhoff + srhlen)
/* transport_header is set after the SRH */
thoff = nhlen - srhlen;
else
/* transport_header falls inside the SRH; hence, we can't
* restore the transport_header pointer properly after
* SRH removing operation.
*/
return false;
pull:
/* we need to pop the SRH:
* 1) first of all, we pull out everything from IPv6 header up to SRH
* (included) evaluating also the rcsum;
* 2) we overwrite (and then remove) the SRH by properly moving the
* IPv6 along with any extension header that precedes the SRH;
* 3) At the end, we push back the pulled headers (except for SRH,
* obviously).
*/
skb_pull_rcsum(skb, srhoff + srhlen);
memmove(skb_network_header(skb) + srhlen, skb_network_header(skb),
srhoff);
skb_push(skb, srhoff);
skb_reset_network_header(skb);
skb_mac_header_rebuild(skb);
if (likely(thoff >= 0))
skb_set_transport_header(skb, thoff);
iph = ipv6_hdr(skb);
if (iph->nexthdr == NEXTHDR_ROUTING) {
iph->nexthdr = srh_nexthdr;
} else {
/* we must look for the extension header (EXTH, for short) that
* immediately precedes the SRH we have just removed.
* Then, we update the value of the EXTH nexthdr with the one
* contained in the SRH nexthdr.
*/
unsigned int off = sizeof(*iph);
struct ipv6_opt_hdr *hp, _hdr;
__u8 nexthdr = iph->nexthdr;
for (;;) {
if (unlikely(!ipv6_ext_hdr(nexthdr) ||
nexthdr == NEXTHDR_NONE))
return false;
hp = skb_header_pointer(skb, off, sizeof(_hdr), &_hdr);
if (unlikely(!hp))
return false;
if (hp->nexthdr == NEXTHDR_ROUTING) {
hp->nexthdr = srh_nexthdr;
break;
}
switch (nexthdr) {
case NEXTHDR_FRAGMENT:
fallthrough;
case NEXTHDR_AUTH:
/* we expect SRH before FRAG and AUTH */
return false;
default:
off += ipv6_optlen(hp);
break;
}
nexthdr = hp->nexthdr;
}
}
iph->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
skb_postpush_rcsum(skb, iph, srhoff);
return true;
}
/* process the packet on the basis of the RFC8986 flavors set for the given
* SRv6 End behavior instance.
*/
static int end_flv8986_core(struct sk_buff *skb, struct seg6_local_lwt *slwt)
{
const struct seg6_flavors_info *finfo = &slwt->flv_info;
enum seg6_local_flv_action action;
enum seg6_local_pktinfo pinfo;
struct ipv6_sr_hdr *srh;
__u32 flvmask;
int srhoff;
srh = seg6_get_srh(skb, 0);
srhoff = srh ? ((unsigned char *)srh - skb->data) : 0;
pinfo = seg6_get_srh_pktinfo(srh);
#ifdef CONFIG_IPV6_SEG6_HMAC
if (srh && !seg6_hmac_validate_skb(skb))
goto drop;
#endif
flvmask = finfo->flv_ops;
if (unlikely(flvmask & ~SEG6_LOCAL_FLV8986_SUPP_OPS)) {
pr_warn_once("seg6local: invalid RFC8986 flavors\n");
goto drop;
}
/* retrieve the action triggered by the combination of pktinfo data and
* the flavors mask.
*/
action = seg6_local_flv8986_act_lookup(pinfo, flvmask);
switch (action) {
case SEG6_LOCAL_FLV_ACT_END:
/* process the packet as the "standard" End behavior */
advance_nextseg(srh, &ipv6_hdr(skb)->daddr);
break;
case SEG6_LOCAL_FLV_ACT_PSP:
advance_nextseg(srh, &ipv6_hdr(skb)->daddr);
if (unlikely(!seg6_pop_srh(skb, srhoff)))
goto drop;
break;
case SEG6_LOCAL_FLV_ACT_UNSPEC:
fallthrough;
default:
/* by default, we drop the packet since we could not find a
* suitable action.
*/
goto drop;
}
return input_action_end_finish(skb, slwt);
drop:
kfree_skb(skb);
return -EINVAL;
}
seg6: add NEXT-C-SID support for SRv6 End behavior The NEXT-C-SID mechanism described in [1] offers the possibility of encoding several SRv6 segments within a single 128 bit SID address. Such a SID address is called a Compressed SID (C-SID) container. In this way, the length of the SID List can be drastically reduced. A SID instantiated with the NEXT-C-SID flavor considers an IPv6 address logically structured in three main blocks: i) Locator-Block; ii) Locator-Node Function; iii) Argument. C-SID container +------------------------------------------------------------------+ | Locator-Block |Loc-Node| Argument | | |Function| | +------------------------------------------------------------------+ <--------- B -----------> <- NF -> <------------- A ---------------> (i) The Locator-Block can be any IPv6 prefix available to the provider; (ii) The Locator-Node Function represents the node and the function to be triggered when a packet is received on the node; (iii) The Argument carries the remaining C-SIDs in the current C-SID container. The NEXT-C-SID mechanism relies on the "flavors" framework defined in [2]. The flavors represent additional operations that can modify or extend a subset of the existing behaviors. This patch introduces the support for flavors in SRv6 End behavior implementing the NEXT-C-SID one. An SRv6 End behavior with NEXT-C-SID flavor works as an End behavior but it is capable of processing the compressed SID List encoded in C-SID containers. An SRv6 End behavior with NEXT-C-SID flavor can be configured to support user-provided Locator-Block and Locator-Node Function lengths. In this implementation, such lengths must be evenly divisible by 8 (i.e. must be byte-aligned), otherwise the kernel informs the user about invalid values with a meaningful error code and message through netlink_ext_ack. If Locator-Block and/or Locator-Node Function lengths are not provided by the user during configuration of an SRv6 End behavior instance with NEXT-C-SID flavor, the kernel will choose their default values i.e., 32-bit Locator-Block and 16-bit Locator-Node Function. [1] - https://datatracker.ietf.org/doc/html/draft-ietf-spring-srv6-srh-compression [2] - https://datatracker.ietf.org/doc/html/rfc8986 Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-09-12 20:16:18 +03:00
/* regular endpoint function */
static int input_action_end(struct sk_buff *skb, struct seg6_local_lwt *slwt)
{
const struct seg6_flavors_info *finfo = &slwt->flv_info;
seg6: add PSP flavor support for SRv6 End behavior The "flavors" framework defined in RFC8986 [1] represents additional operations that can modify or extend a subset of existing behaviors such as SRv6 End, End.X and End.T. We report these flavors hereafter: - Penultimate Segment Pop (PSP); - Ultimate Segment Pop (USP); - Ultimate Segment Decapsulation (USD). Depending on how the Segment Routing Header (SRH) has to be handled, an SRv6 End* behavior can support these flavors either individually or in combinations. In this patch, we only consider the PSP flavor for the SRv6 End behavior. A PSP enabled SRv6 End behavior is used by the Source/Ingress SR node (i.e., the one applying the SRv6 Policy) when it needs to instruct the penultimate SR Endpoint node listed in the SID List (carried by the SRH) to remove the SRH from the IPv6 header. Specifically, a PSP enabled SRv6 End behavior processes the SRH by: i) decreasing the Segment Left (SL) from 1 to 0; ii) copying the Last Segment IDentifier (SID) into the IPv6 Destination Address (DA); iii) removing (i.e., popping) the outer SRH from the extension headers following the IPv6 header. It is important to note that PSP operation (steps i, ii, iii) takes place only at a penultimate SR Segment Endpoint node (i.e., when the SL=1) and does not happen at non-penultimate Endpoint nodes. Indeed, when a SID of PSP flavor is processed at a non-penultimate SR Segment Endpoint node, the PSP operation is not performed because it would not be possible to decrease the SL from 1 to 0. SL=2 SL=1 SL=0 | | | For example, given the SRv6 policy (SID List := < X, Y, Z >): - a PSP enabled SRv6 End behavior bound to SID "Y" will apply the PSP operation as Segment Left (SL) is 1, corresponding to the Penultimate Segment of the SID List; - a PSP enabled SRv6 End behavior bound to SID "X" will *NOT* apply the PSP operation as the Segment Left is 2. This behavior instance will apply the "standard" End packet processing, ignoring the configured PSP flavor at all. [1] - RFC8986: https://datatracker.ietf.org/doc/html/rfc8986 Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2023-02-15 16:46:58 +03:00
__u32 fops = finfo->flv_ops;
seg6: add NEXT-C-SID support for SRv6 End behavior The NEXT-C-SID mechanism described in [1] offers the possibility of encoding several SRv6 segments within a single 128 bit SID address. Such a SID address is called a Compressed SID (C-SID) container. In this way, the length of the SID List can be drastically reduced. A SID instantiated with the NEXT-C-SID flavor considers an IPv6 address logically structured in three main blocks: i) Locator-Block; ii) Locator-Node Function; iii) Argument. C-SID container +------------------------------------------------------------------+ | Locator-Block |Loc-Node| Argument | | |Function| | +------------------------------------------------------------------+ <--------- B -----------> <- NF -> <------------- A ---------------> (i) The Locator-Block can be any IPv6 prefix available to the provider; (ii) The Locator-Node Function represents the node and the function to be triggered when a packet is received on the node; (iii) The Argument carries the remaining C-SIDs in the current C-SID container. The NEXT-C-SID mechanism relies on the "flavors" framework defined in [2]. The flavors represent additional operations that can modify or extend a subset of the existing behaviors. This patch introduces the support for flavors in SRv6 End behavior implementing the NEXT-C-SID one. An SRv6 End behavior with NEXT-C-SID flavor works as an End behavior but it is capable of processing the compressed SID List encoded in C-SID containers. An SRv6 End behavior with NEXT-C-SID flavor can be configured to support user-provided Locator-Block and Locator-Node Function lengths. In this implementation, such lengths must be evenly divisible by 8 (i.e. must be byte-aligned), otherwise the kernel informs the user about invalid values with a meaningful error code and message through netlink_ext_ack. If Locator-Block and/or Locator-Node Function lengths are not provided by the user during configuration of an SRv6 End behavior instance with NEXT-C-SID flavor, the kernel will choose their default values i.e., 32-bit Locator-Block and 16-bit Locator-Node Function. [1] - https://datatracker.ietf.org/doc/html/draft-ietf-spring-srv6-srh-compression [2] - https://datatracker.ietf.org/doc/html/rfc8986 Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-09-12 20:16:18 +03:00
seg6: add PSP flavor support for SRv6 End behavior The "flavors" framework defined in RFC8986 [1] represents additional operations that can modify or extend a subset of existing behaviors such as SRv6 End, End.X and End.T. We report these flavors hereafter: - Penultimate Segment Pop (PSP); - Ultimate Segment Pop (USP); - Ultimate Segment Decapsulation (USD). Depending on how the Segment Routing Header (SRH) has to be handled, an SRv6 End* behavior can support these flavors either individually or in combinations. In this patch, we only consider the PSP flavor for the SRv6 End behavior. A PSP enabled SRv6 End behavior is used by the Source/Ingress SR node (i.e., the one applying the SRv6 Policy) when it needs to instruct the penultimate SR Endpoint node listed in the SID List (carried by the SRH) to remove the SRH from the IPv6 header. Specifically, a PSP enabled SRv6 End behavior processes the SRH by: i) decreasing the Segment Left (SL) from 1 to 0; ii) copying the Last Segment IDentifier (SID) into the IPv6 Destination Address (DA); iii) removing (i.e., popping) the outer SRH from the extension headers following the IPv6 header. It is important to note that PSP operation (steps i, ii, iii) takes place only at a penultimate SR Segment Endpoint node (i.e., when the SL=1) and does not happen at non-penultimate Endpoint nodes. Indeed, when a SID of PSP flavor is processed at a non-penultimate SR Segment Endpoint node, the PSP operation is not performed because it would not be possible to decrease the SL from 1 to 0. SL=2 SL=1 SL=0 | | | For example, given the SRv6 policy (SID List := < X, Y, Z >): - a PSP enabled SRv6 End behavior bound to SID "Y" will apply the PSP operation as Segment Left (SL) is 1, corresponding to the Penultimate Segment of the SID List; - a PSP enabled SRv6 End behavior bound to SID "X" will *NOT* apply the PSP operation as the Segment Left is 2. This behavior instance will apply the "standard" End packet processing, ignoring the configured PSP flavor at all. [1] - RFC8986: https://datatracker.ietf.org/doc/html/rfc8986 Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2023-02-15 16:46:58 +03:00
if (!fops)
return input_action_end_core(skb, slwt);
/* check for the presence of NEXT-C-SID since it applies first */
if (seg6_next_csid_enabled(fops))
seg6: add NEXT-C-SID support for SRv6 End behavior The NEXT-C-SID mechanism described in [1] offers the possibility of encoding several SRv6 segments within a single 128 bit SID address. Such a SID address is called a Compressed SID (C-SID) container. In this way, the length of the SID List can be drastically reduced. A SID instantiated with the NEXT-C-SID flavor considers an IPv6 address logically structured in three main blocks: i) Locator-Block; ii) Locator-Node Function; iii) Argument. C-SID container +------------------------------------------------------------------+ | Locator-Block |Loc-Node| Argument | | |Function| | +------------------------------------------------------------------+ <--------- B -----------> <- NF -> <------------- A ---------------> (i) The Locator-Block can be any IPv6 prefix available to the provider; (ii) The Locator-Node Function represents the node and the function to be triggered when a packet is received on the node; (iii) The Argument carries the remaining C-SIDs in the current C-SID container. The NEXT-C-SID mechanism relies on the "flavors" framework defined in [2]. The flavors represent additional operations that can modify or extend a subset of the existing behaviors. This patch introduces the support for flavors in SRv6 End behavior implementing the NEXT-C-SID one. An SRv6 End behavior with NEXT-C-SID flavor works as an End behavior but it is capable of processing the compressed SID List encoded in C-SID containers. An SRv6 End behavior with NEXT-C-SID flavor can be configured to support user-provided Locator-Block and Locator-Node Function lengths. In this implementation, such lengths must be evenly divisible by 8 (i.e. must be byte-aligned), otherwise the kernel informs the user about invalid values with a meaningful error code and message through netlink_ext_ack. If Locator-Block and/or Locator-Node Function lengths are not provided by the user during configuration of an SRv6 End behavior instance with NEXT-C-SID flavor, the kernel will choose their default values i.e., 32-bit Locator-Block and 16-bit Locator-Node Function. [1] - https://datatracker.ietf.org/doc/html/draft-ietf-spring-srv6-srh-compression [2] - https://datatracker.ietf.org/doc/html/rfc8986 Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-09-12 20:16:18 +03:00
return end_next_csid_core(skb, slwt);
seg6: add PSP flavor support for SRv6 End behavior The "flavors" framework defined in RFC8986 [1] represents additional operations that can modify or extend a subset of existing behaviors such as SRv6 End, End.X and End.T. We report these flavors hereafter: - Penultimate Segment Pop (PSP); - Ultimate Segment Pop (USP); - Ultimate Segment Decapsulation (USD). Depending on how the Segment Routing Header (SRH) has to be handled, an SRv6 End* behavior can support these flavors either individually or in combinations. In this patch, we only consider the PSP flavor for the SRv6 End behavior. A PSP enabled SRv6 End behavior is used by the Source/Ingress SR node (i.e., the one applying the SRv6 Policy) when it needs to instruct the penultimate SR Endpoint node listed in the SID List (carried by the SRH) to remove the SRH from the IPv6 header. Specifically, a PSP enabled SRv6 End behavior processes the SRH by: i) decreasing the Segment Left (SL) from 1 to 0; ii) copying the Last Segment IDentifier (SID) into the IPv6 Destination Address (DA); iii) removing (i.e., popping) the outer SRH from the extension headers following the IPv6 header. It is important to note that PSP operation (steps i, ii, iii) takes place only at a penultimate SR Segment Endpoint node (i.e., when the SL=1) and does not happen at non-penultimate Endpoint nodes. Indeed, when a SID of PSP flavor is processed at a non-penultimate SR Segment Endpoint node, the PSP operation is not performed because it would not be possible to decrease the SL from 1 to 0. SL=2 SL=1 SL=0 | | | For example, given the SRv6 policy (SID List := < X, Y, Z >): - a PSP enabled SRv6 End behavior bound to SID "Y" will apply the PSP operation as Segment Left (SL) is 1, corresponding to the Penultimate Segment of the SID List; - a PSP enabled SRv6 End behavior bound to SID "X" will *NOT* apply the PSP operation as the Segment Left is 2. This behavior instance will apply the "standard" End packet processing, ignoring the configured PSP flavor at all. [1] - RFC8986: https://datatracker.ietf.org/doc/html/rfc8986 Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2023-02-15 16:46:58 +03:00
/* the specific processing function to be performed on the packet
* depends on the combination of flavors defined in RFC8986 and some
* information extracted from the packet, e.g. presence/absence of SRH,
* Segment Left = 0, etc.
*/
return end_flv8986_core(skb, slwt);
seg6: add NEXT-C-SID support for SRv6 End behavior The NEXT-C-SID mechanism described in [1] offers the possibility of encoding several SRv6 segments within a single 128 bit SID address. Such a SID address is called a Compressed SID (C-SID) container. In this way, the length of the SID List can be drastically reduced. A SID instantiated with the NEXT-C-SID flavor considers an IPv6 address logically structured in three main blocks: i) Locator-Block; ii) Locator-Node Function; iii) Argument. C-SID container +------------------------------------------------------------------+ | Locator-Block |Loc-Node| Argument | | |Function| | +------------------------------------------------------------------+ <--------- B -----------> <- NF -> <------------- A ---------------> (i) The Locator-Block can be any IPv6 prefix available to the provider; (ii) The Locator-Node Function represents the node and the function to be triggered when a packet is received on the node; (iii) The Argument carries the remaining C-SIDs in the current C-SID container. The NEXT-C-SID mechanism relies on the "flavors" framework defined in [2]. The flavors represent additional operations that can modify or extend a subset of the existing behaviors. This patch introduces the support for flavors in SRv6 End behavior implementing the NEXT-C-SID one. An SRv6 End behavior with NEXT-C-SID flavor works as an End behavior but it is capable of processing the compressed SID List encoded in C-SID containers. An SRv6 End behavior with NEXT-C-SID flavor can be configured to support user-provided Locator-Block and Locator-Node Function lengths. In this implementation, such lengths must be evenly divisible by 8 (i.e. must be byte-aligned), otherwise the kernel informs the user about invalid values with a meaningful error code and message through netlink_ext_ack. If Locator-Block and/or Locator-Node Function lengths are not provided by the user during configuration of an SRv6 End behavior instance with NEXT-C-SID flavor, the kernel will choose their default values i.e., 32-bit Locator-Block and 16-bit Locator-Node Function. [1] - https://datatracker.ietf.org/doc/html/draft-ietf-spring-srv6-srh-compression [2] - https://datatracker.ietf.org/doc/html/rfc8986 Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-09-12 20:16:18 +03:00
}
ipv6: sr: implement several seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END: regular SRH processing. The DA of the packet is updated to the next segment and forwarded accordingly. - SEG6_LOCAL_ACTION_END_X: same as above, except that the packet is forwarded to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_DX6: decapsulate the packet and forward to inner IPv6 packet to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_B6: insert the specified SRH directly after the IPv6 header of the packet. - SEG6_LOCAL_ACTION_END_B6_ENCAP: encapsulate the packet within an outer IPv6 header, containing the specified SRH. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:39:48 +03:00
/* regular endpoint, and forward to specified nexthop */
static int input_action_end_x(struct sk_buff *skb, struct seg6_local_lwt *slwt)
{
struct ipv6_sr_hdr *srh;
srh = get_and_validate_srh(skb);
if (!srh)
goto drop;
ipv6: sr: add helper functions for seg6local This patch adds three helper functions to be used with the seg6local packet processing actions. The decap_and_validate() function will be used by the End.D* actions, that decapsulate an SR-enabled packet. The advance_nextseg() function applies the fundamental operations to update an SRH for the next segment. The lookup_nexthop() function helps select the next-hop for the processed SR packets. It supports an optional next-hop address to route the packet specifically through it, and an optional routing table to use. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 10:56:47 +03:00
advance_nextseg(srh, &ipv6_hdr(skb)->daddr);
ipv6: sr: implement several seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END: regular SRH processing. The DA of the packet is updated to the next segment and forwarded accordingly. - SEG6_LOCAL_ACTION_END_X: same as above, except that the packet is forwarded to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_DX6: decapsulate the packet and forward to inner IPv6 packet to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_B6: insert the specified SRH directly after the IPv6 header of the packet. - SEG6_LOCAL_ACTION_END_B6_ENCAP: encapsulate the packet within an outer IPv6 header, containing the specified SRH. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:39:48 +03:00
ipv6: sr: export function lookup_nexthop The function lookup_nexthop is essential to implement most of the seg6local actions. As we want to provide a BPF helper allowing to apply some of these actions on the packet being processed, the helper should be able to call this function, hence the need to make it public. Moreover, if one argument is incorrect or if the next hop can not be found, an error should be returned by the BPF helper so the BPF program can adapt its processing of the packet (return an error, properly force the drop, ...). This patch hence makes this function return dst->error to indicate a possible error. Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-20 16:58:13 +03:00
seg6_lookup_nexthop(skb, &slwt->nh6, 0);
ipv6: sr: implement several seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END: regular SRH processing. The DA of the packet is updated to the next segment and forwarded accordingly. - SEG6_LOCAL_ACTION_END_X: same as above, except that the packet is forwarded to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_DX6: decapsulate the packet and forward to inner IPv6 packet to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_B6: insert the specified SRH directly after the IPv6 header of the packet. - SEG6_LOCAL_ACTION_END_B6_ENCAP: encapsulate the packet within an outer IPv6 header, containing the specified SRH. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:39:48 +03:00
return dst_input(skb);
drop:
kfree_skb(skb);
return -EINVAL;
}
ipv6: sr: implement additional seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END_T: regular SRH processing and forward to the next-hop looked up in the specified routing table. - SEG6_LOCAL_ACTION_END_DX2: decapsulate an L2 frame and forward it to the specified network interface. - SEG6_LOCAL_ACTION_END_DX4: decapsulate an IPv4 packet and forward it, possibly to the specified next-hop. - SEG6_LOCAL_ACTION_END_DT6: decapsulate an IPv6 packet and forward it to the next-hop looked up in the specified routing table. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 10:58:17 +03:00
static int input_action_end_t(struct sk_buff *skb, struct seg6_local_lwt *slwt)
{
struct ipv6_sr_hdr *srh;
srh = get_and_validate_srh(skb);
if (!srh)
goto drop;
advance_nextseg(srh, &ipv6_hdr(skb)->daddr);
ipv6: sr: export function lookup_nexthop The function lookup_nexthop is essential to implement most of the seg6local actions. As we want to provide a BPF helper allowing to apply some of these actions on the packet being processed, the helper should be able to call this function, hence the need to make it public. Moreover, if one argument is incorrect or if the next hop can not be found, an error should be returned by the BPF helper so the BPF program can adapt its processing of the packet (return an error, properly force the drop, ...). This patch hence makes this function return dst->error to indicate a possible error. Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-20 16:58:13 +03:00
seg6_lookup_nexthop(skb, NULL, slwt->table);
ipv6: sr: implement additional seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END_T: regular SRH processing and forward to the next-hop looked up in the specified routing table. - SEG6_LOCAL_ACTION_END_DX2: decapsulate an L2 frame and forward it to the specified network interface. - SEG6_LOCAL_ACTION_END_DX4: decapsulate an IPv4 packet and forward it, possibly to the specified next-hop. - SEG6_LOCAL_ACTION_END_DT6: decapsulate an IPv6 packet and forward it to the next-hop looked up in the specified routing table. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 10:58:17 +03:00
return dst_input(skb);
drop:
kfree_skb(skb);
return -EINVAL;
}
/* decapsulate and forward inner L2 frame on specified interface */
static int input_action_end_dx2(struct sk_buff *skb,
struct seg6_local_lwt *slwt)
{
struct net *net = dev_net(skb->dev);
struct net_device *odev;
struct ethhdr *eth;
seg6: fix SRv6 L2 tunnels to use IANA-assigned protocol number The Internet Assigned Numbers Authority (IANA) has recently assigned a protocol number value of 143 for Ethernet [1]. Before this assignment, encapsulation mechanisms such as Segment Routing used the IPv6-NoNxt protocol number (59) to indicate that the encapsulated payload is an Ethernet frame. In this patch, we add the definition of the Ethernet protocol number to the kernel headers and update the SRv6 L2 tunnels to use it. [1] https://www.iana.org/assignments/protocol-numbers/protocol-numbers.xhtml Signed-off-by: Paolo Lungaroni <paolo.lungaroni@cnit.it> Reviewed-by: Andrea Mayer <andrea.mayer@uniroma2.it> Acked-by: Ahmed Abdelsalam <ahmed.abdelsalam@gssi.it> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-11 19:54:06 +03:00
if (!decap_and_validate(skb, IPPROTO_ETHERNET))
ipv6: sr: implement additional seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END_T: regular SRH processing and forward to the next-hop looked up in the specified routing table. - SEG6_LOCAL_ACTION_END_DX2: decapsulate an L2 frame and forward it to the specified network interface. - SEG6_LOCAL_ACTION_END_DX4: decapsulate an IPv4 packet and forward it, possibly to the specified next-hop. - SEG6_LOCAL_ACTION_END_DT6: decapsulate an IPv6 packet and forward it to the next-hop looked up in the specified routing table. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 10:58:17 +03:00
goto drop;
if (!pskb_may_pull(skb, ETH_HLEN))
goto drop;
skb_reset_mac_header(skb);
eth = (struct ethhdr *)skb->data;
/* To determine the frame's protocol, we assume it is 802.3. This avoids
* a call to eth_type_trans(), which is not really relevant for our
* use case.
*/
if (!eth_proto_is_802_3(eth->h_proto))
goto drop;
odev = dev_get_by_index_rcu(net, slwt->oif);
if (!odev)
goto drop;
/* As we accept Ethernet frames, make sure the egress device is of
* the correct type.
*/
if (odev->type != ARPHRD_ETHER)
goto drop;
if (!(odev->flags & IFF_UP) || !netif_carrier_ok(odev))
goto drop;
skb_orphan(skb);
if (skb_warn_if_lro(skb))
goto drop;
skb_forward_csum(skb);
if (skb->len - ETH_HLEN > odev->mtu)
goto drop;
skb->dev = odev;
skb->protocol = eth->h_proto;
return dev_queue_xmit(skb);
drop:
kfree_skb(skb);
return -EINVAL;
}
netfilter: add netfilter hooks to SRv6 data plane This patch introduces netfilter hooks for solving the problem that conntrack couldn't record both inner flows and outer flows. This patch also introduces a new sysctl toggle for enabling lightweight tunnel netfilter hooks. Signed-off-by: Ryoga Saito <contact@proelbtn.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-08-17 11:39:37 +03:00
static int input_action_end_dx6_finish(struct net *net, struct sock *sk,
struct sk_buff *skb)
{
struct dst_entry *orig_dst = skb_dst(skb);
struct in6_addr *nhaddr = NULL;
struct seg6_local_lwt *slwt;
slwt = seg6_local_lwtunnel(orig_dst->lwtstate);
/* The inner packet is not associated to any local interface,
* so we do not call netif_rx().
*
* If slwt->nh6 is set to ::, then lookup the nexthop for the
* inner packet's DA. Otherwise, use the specified nexthop.
*/
if (!ipv6_addr_any(&slwt->nh6))
nhaddr = &slwt->nh6;
seg6_lookup_nexthop(skb, nhaddr, 0);
return dst_input(skb);
}
ipv6: sr: implement several seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END: regular SRH processing. The DA of the packet is updated to the next segment and forwarded accordingly. - SEG6_LOCAL_ACTION_END_X: same as above, except that the packet is forwarded to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_DX6: decapsulate the packet and forward to inner IPv6 packet to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_B6: insert the specified SRH directly after the IPv6 header of the packet. - SEG6_LOCAL_ACTION_END_B6_ENCAP: encapsulate the packet within an outer IPv6 header, containing the specified SRH. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:39:48 +03:00
/* decapsulate and forward to specified nexthop */
static int input_action_end_dx6(struct sk_buff *skb,
struct seg6_local_lwt *slwt)
{
/* this function accepts IPv6 encapsulated packets, with either
* an SRH with SL=0, or no SRH.
*/
ipv6: sr: add helper functions for seg6local This patch adds three helper functions to be used with the seg6local packet processing actions. The decap_and_validate() function will be used by the End.D* actions, that decapsulate an SR-enabled packet. The advance_nextseg() function applies the fundamental operations to update an SRH for the next segment. The lookup_nexthop() function helps select the next-hop for the processed SR packets. It supports an optional next-hop address to route the packet specifically through it, and an optional routing table to use. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 10:56:47 +03:00
if (!decap_and_validate(skb, IPPROTO_IPV6))
ipv6: sr: implement several seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END: regular SRH processing. The DA of the packet is updated to the next segment and forwarded accordingly. - SEG6_LOCAL_ACTION_END_X: same as above, except that the packet is forwarded to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_DX6: decapsulate the packet and forward to inner IPv6 packet to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_B6: insert the specified SRH directly after the IPv6 header of the packet. - SEG6_LOCAL_ACTION_END_B6_ENCAP: encapsulate the packet within an outer IPv6 header, containing the specified SRH. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:39:48 +03:00
goto drop;
ipv6: sr: add helper functions for seg6local This patch adds three helper functions to be used with the seg6local packet processing actions. The decap_and_validate() function will be used by the End.D* actions, that decapsulate an SR-enabled packet. The advance_nextseg() function applies the fundamental operations to update an SRH for the next segment. The lookup_nexthop() function helps select the next-hop for the processed SR packets. It supports an optional next-hop address to route the packet specifically through it, and an optional routing table to use. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 10:56:47 +03:00
if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
ipv6: sr: implement several seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END: regular SRH processing. The DA of the packet is updated to the next segment and forwarded accordingly. - SEG6_LOCAL_ACTION_END_X: same as above, except that the packet is forwarded to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_DX6: decapsulate the packet and forward to inner IPv6 packet to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_B6: insert the specified SRH directly after the IPv6 header of the packet. - SEG6_LOCAL_ACTION_END_B6_ENCAP: encapsulate the packet within an outer IPv6 header, containing the specified SRH. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:39:48 +03:00
goto drop;
seg6: fix skb transport_header after decap_and_validate() in the receive path (more precisely in ip6_rcv_core()) the skb->transport_header is set to skb->network_header + sizeof(*hdr). As a consequence, after routing operations, destination input expects to find skb->transport_header correctly set to the next protocol (or extension header) that follows the network protocol. However, decap behaviors (DX*, DT*) remove the outer IPv6 and SRH extension and do not set again the skb->transport_header pointer correctly. For this reason, the patch sets the skb->transport_header to the skb->network_header + sizeof(hdr) in each DX* and DT* behavior. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-16 18:05:53 +03:00
skb_set_transport_header(skb, sizeof(struct ipv6hdr));
netfilter: add netfilter hooks to SRv6 data plane This patch introduces netfilter hooks for solving the problem that conntrack couldn't record both inner flows and outer flows. This patch also introduces a new sysctl toggle for enabling lightweight tunnel netfilter hooks. Signed-off-by: Ryoga Saito <contact@proelbtn.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-08-17 11:39:37 +03:00
nf_reset_ct(skb);
seg6: fix skb transport_header after decap_and_validate() in the receive path (more precisely in ip6_rcv_core()) the skb->transport_header is set to skb->network_header + sizeof(*hdr). As a consequence, after routing operations, destination input expects to find skb->transport_header correctly set to the next protocol (or extension header) that follows the network protocol. However, decap behaviors (DX*, DT*) remove the outer IPv6 and SRH extension and do not set again the skb->transport_header pointer correctly. For this reason, the patch sets the skb->transport_header to the skb->network_header + sizeof(hdr) in each DX* and DT* behavior. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-16 18:05:53 +03:00
netfilter: add netfilter hooks to SRv6 data plane This patch introduces netfilter hooks for solving the problem that conntrack couldn't record both inner flows and outer flows. This patch also introduces a new sysctl toggle for enabling lightweight tunnel netfilter hooks. Signed-off-by: Ryoga Saito <contact@proelbtn.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-08-17 11:39:37 +03:00
if (static_branch_unlikely(&nf_hooks_lwtunnel_enabled))
return NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING,
dev_net(skb->dev), NULL, skb, NULL,
skb_dst(skb)->dev, input_action_end_dx6_finish);
ipv6: sr: implement several seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END: regular SRH processing. The DA of the packet is updated to the next segment and forwarded accordingly. - SEG6_LOCAL_ACTION_END_X: same as above, except that the packet is forwarded to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_DX6: decapsulate the packet and forward to inner IPv6 packet to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_B6: insert the specified SRH directly after the IPv6 header of the packet. - SEG6_LOCAL_ACTION_END_B6_ENCAP: encapsulate the packet within an outer IPv6 header, containing the specified SRH. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:39:48 +03:00
netfilter: add netfilter hooks to SRv6 data plane This patch introduces netfilter hooks for solving the problem that conntrack couldn't record both inner flows and outer flows. This patch also introduces a new sysctl toggle for enabling lightweight tunnel netfilter hooks. Signed-off-by: Ryoga Saito <contact@proelbtn.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-08-17 11:39:37 +03:00
return input_action_end_dx6_finish(dev_net(skb->dev), NULL, skb);
ipv6: sr: implement several seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END: regular SRH processing. The DA of the packet is updated to the next segment and forwarded accordingly. - SEG6_LOCAL_ACTION_END_X: same as above, except that the packet is forwarded to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_DX6: decapsulate the packet and forward to inner IPv6 packet to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_B6: insert the specified SRH directly after the IPv6 header of the packet. - SEG6_LOCAL_ACTION_END_B6_ENCAP: encapsulate the packet within an outer IPv6 header, containing the specified SRH. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:39:48 +03:00
drop:
kfree_skb(skb);
return -EINVAL;
}
netfilter: add netfilter hooks to SRv6 data plane This patch introduces netfilter hooks for solving the problem that conntrack couldn't record both inner flows and outer flows. This patch also introduces a new sysctl toggle for enabling lightweight tunnel netfilter hooks. Signed-off-by: Ryoga Saito <contact@proelbtn.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-08-17 11:39:37 +03:00
static int input_action_end_dx4_finish(struct net *net, struct sock *sk,
struct sk_buff *skb)
ipv6: sr: implement additional seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END_T: regular SRH processing and forward to the next-hop looked up in the specified routing table. - SEG6_LOCAL_ACTION_END_DX2: decapsulate an L2 frame and forward it to the specified network interface. - SEG6_LOCAL_ACTION_END_DX4: decapsulate an IPv4 packet and forward it, possibly to the specified next-hop. - SEG6_LOCAL_ACTION_END_DT6: decapsulate an IPv6 packet and forward it to the next-hop looked up in the specified routing table. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 10:58:17 +03:00
{
netfilter: add netfilter hooks to SRv6 data plane This patch introduces netfilter hooks for solving the problem that conntrack couldn't record both inner flows and outer flows. This patch also introduces a new sysctl toggle for enabling lightweight tunnel netfilter hooks. Signed-off-by: Ryoga Saito <contact@proelbtn.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-08-17 11:39:37 +03:00
struct dst_entry *orig_dst = skb_dst(skb);
struct seg6_local_lwt *slwt;
ipv6: sr: implement additional seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END_T: regular SRH processing and forward to the next-hop looked up in the specified routing table. - SEG6_LOCAL_ACTION_END_DX2: decapsulate an L2 frame and forward it to the specified network interface. - SEG6_LOCAL_ACTION_END_DX4: decapsulate an IPv4 packet and forward it, possibly to the specified next-hop. - SEG6_LOCAL_ACTION_END_DT6: decapsulate an IPv6 packet and forward it to the next-hop looked up in the specified routing table. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 10:58:17 +03:00
struct iphdr *iph;
__be32 nhaddr;
int err;
netfilter: add netfilter hooks to SRv6 data plane This patch introduces netfilter hooks for solving the problem that conntrack couldn't record both inner flows and outer flows. This patch also introduces a new sysctl toggle for enabling lightweight tunnel netfilter hooks. Signed-off-by: Ryoga Saito <contact@proelbtn.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-08-17 11:39:37 +03:00
slwt = seg6_local_lwtunnel(orig_dst->lwtstate);
ipv6: sr: implement additional seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END_T: regular SRH processing and forward to the next-hop looked up in the specified routing table. - SEG6_LOCAL_ACTION_END_DX2: decapsulate an L2 frame and forward it to the specified network interface. - SEG6_LOCAL_ACTION_END_DX4: decapsulate an IPv4 packet and forward it, possibly to the specified next-hop. - SEG6_LOCAL_ACTION_END_DT6: decapsulate an IPv6 packet and forward it to the next-hop looked up in the specified routing table. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 10:58:17 +03:00
iph = ip_hdr(skb);
nhaddr = slwt->nh4.s_addr ?: iph->daddr;
skb_dst_drop(skb);
err = ip_route_input(skb, nhaddr, iph->saddr, 0, skb->dev);
netfilter: add netfilter hooks to SRv6 data plane This patch introduces netfilter hooks for solving the problem that conntrack couldn't record both inner flows and outer flows. This patch also introduces a new sysctl toggle for enabling lightweight tunnel netfilter hooks. Signed-off-by: Ryoga Saito <contact@proelbtn.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-08-17 11:39:37 +03:00
if (err) {
kfree_skb(skb);
return -EINVAL;
}
ipv6: sr: implement additional seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END_T: regular SRH processing and forward to the next-hop looked up in the specified routing table. - SEG6_LOCAL_ACTION_END_DX2: decapsulate an L2 frame and forward it to the specified network interface. - SEG6_LOCAL_ACTION_END_DX4: decapsulate an IPv4 packet and forward it, possibly to the specified next-hop. - SEG6_LOCAL_ACTION_END_DT6: decapsulate an IPv6 packet and forward it to the next-hop looked up in the specified routing table. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 10:58:17 +03:00
return dst_input(skb);
netfilter: add netfilter hooks to SRv6 data plane This patch introduces netfilter hooks for solving the problem that conntrack couldn't record both inner flows and outer flows. This patch also introduces a new sysctl toggle for enabling lightweight tunnel netfilter hooks. Signed-off-by: Ryoga Saito <contact@proelbtn.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-08-17 11:39:37 +03:00
}
static int input_action_end_dx4(struct sk_buff *skb,
struct seg6_local_lwt *slwt)
{
if (!decap_and_validate(skb, IPPROTO_IPIP))
goto drop;
if (!pskb_may_pull(skb, sizeof(struct iphdr)))
goto drop;
skb->protocol = htons(ETH_P_IP);
skb_set_transport_header(skb, sizeof(struct iphdr));
nf_reset_ct(skb);
if (static_branch_unlikely(&nf_hooks_lwtunnel_enabled))
return NF_HOOK(NFPROTO_IPV4, NF_INET_PRE_ROUTING,
dev_net(skb->dev), NULL, skb, NULL,
skb_dst(skb)->dev, input_action_end_dx4_finish);
ipv6: sr: implement additional seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END_T: regular SRH processing and forward to the next-hop looked up in the specified routing table. - SEG6_LOCAL_ACTION_END_DX2: decapsulate an L2 frame and forward it to the specified network interface. - SEG6_LOCAL_ACTION_END_DX4: decapsulate an IPv4 packet and forward it, possibly to the specified next-hop. - SEG6_LOCAL_ACTION_END_DT6: decapsulate an IPv6 packet and forward it to the next-hop looked up in the specified routing table. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 10:58:17 +03:00
netfilter: add netfilter hooks to SRv6 data plane This patch introduces netfilter hooks for solving the problem that conntrack couldn't record both inner flows and outer flows. This patch also introduces a new sysctl toggle for enabling lightweight tunnel netfilter hooks. Signed-off-by: Ryoga Saito <contact@proelbtn.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-08-17 11:39:37 +03:00
return input_action_end_dx4_finish(dev_net(skb->dev), NULL, skb);
ipv6: sr: implement additional seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END_T: regular SRH processing and forward to the next-hop looked up in the specified routing table. - SEG6_LOCAL_ACTION_END_DX2: decapsulate an L2 frame and forward it to the specified network interface. - SEG6_LOCAL_ACTION_END_DX4: decapsulate an IPv4 packet and forward it, possibly to the specified next-hop. - SEG6_LOCAL_ACTION_END_DT6: decapsulate an IPv6 packet and forward it to the next-hop looked up in the specified routing table. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 10:58:17 +03:00
drop:
kfree_skb(skb);
return -EINVAL;
}
seg6: add support for the SRv6 End.DT4 behavior SRv6 End.DT4 is defined in the SRv6 Network Programming [1]. The SRv6 End.DT4 is used to implement IPv4 L3VPN use-cases in multi-tenants environments. It decapsulates the received packets and it performs IPv4 routing lookup in the routing table of the tenant. The SRv6 End.DT4 Linux implementation leverages a VRF device in order to force the routing lookup into the associated routing table. To make the End.DT4 work properly, it must be guaranteed that the routing table used for routing lookup operations is bound to one and only one VRF during the tunnel creation. Such constraint has to be enforced by enabling the VRF strict_mode sysctl parameter, i.e: $ sysctl -wq net.vrf.strict_mode=1. At JANOG44, LINE corporation presented their multi-tenant DC architecture using SRv6 [2]. In the slides, they reported that the Linux kernel is missing the support of SRv6 End.DT4 behavior. The SRv6 End.DT4 behavior can be instantiated using a command similar to the following: $ ip route add 2001:db8::1 encap seg6local action End.DT4 vrftable 100 dev eth0 We introduce the "vrftable" extension in iproute2 in a following patch. [1] https://tools.ietf.org/html/draft-ietf-spring-srv6-network-programming [2] https://speakerdeck.com/line_developers/line-data-center-networking-with-srv6 Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:14 +03:00
#ifdef CONFIG_NET_L3_MASTER_DEV
static struct net *fib6_config_get_net(const struct fib6_config *fib6_cfg)
{
const struct nl_info *nli = &fib6_cfg->fc_nlinfo;
return nli->nl_net;
}
static int __seg6_end_dt_vrf_build(struct seg6_local_lwt *slwt, const void *cfg,
u16 family, struct netlink_ext_ack *extack)
{
struct seg6_end_dt_info *info = &slwt->dt_info;
int vrf_ifindex;
struct net *net;
net = fib6_config_get_net(cfg);
/* note that vrf_table was already set by parse_nla_vrftable() */
vrf_ifindex = l3mdev_ifindex_lookup_by_table_id(L3MDEV_TYPE_VRF, net,
info->vrf_table);
if (vrf_ifindex < 0) {
if (vrf_ifindex == -EPERM) {
NL_SET_ERR_MSG(extack,
"Strict mode for VRF is disabled");
} else if (vrf_ifindex == -ENODEV) {
NL_SET_ERR_MSG(extack,
"Table has no associated VRF device");
} else {
pr_debug("seg6local: SRv6 End.DT* creation error=%d\n",
vrf_ifindex);
}
return vrf_ifindex;
}
info->net = net;
info->vrf_ifindex = vrf_ifindex;
info->family = family;
info->mode = DT_VRF_MODE;
return 0;
}
/* The SRv6 End.DT4/DT6 behavior extracts the inner (IPv4/IPv6) packet and
* routes the IPv4/IPv6 packet by looking at the configured routing table.
*
* In the SRv6 End.DT4/DT6 use case, we can receive traffic (IPv6+Segment
* Routing Header packets) from several interfaces and the outer IPv6
* destination address (DA) is used for retrieving the specific instance of the
* End.DT4/DT6 behavior that should process the packets.
*
* However, the inner IPv4/IPv6 packet is not really bound to any receiving
* interface and thus the End.DT4/DT6 sets the VRF (associated with the
* corresponding routing table) as the *receiving* interface.
* In other words, the End.DT4/DT6 processes a packet as if it has been received
* directly by the VRF (and not by one of its slave devices, if any).
* In this way, the VRF interface is used for routing the IPv4/IPv6 packet in
* according to the routing table configured by the End.DT4/DT6 instance.
*
* This design allows you to get some interesting features like:
* 1) the statistics on rx packets;
* 2) the possibility to install a packet sniffer on the receiving interface
* (the VRF one) for looking at the incoming packets;
* 3) the possibility to leverage the netfilter prerouting hook for the inner
* IPv4 packet.
*
* This function returns:
* - the sk_buff* when the VRF rcv handler has processed the packet correctly;
* - NULL when the skb is consumed by the VRF rcv handler;
* - a pointer which encodes a negative error number in case of error.
* Note that in this case, the function takes care of freeing the skb.
*/
static struct sk_buff *end_dt_vrf_rcv(struct sk_buff *skb, u16 family,
struct net_device *dev)
{
/* based on l3mdev_ip_rcv; we are only interested in the master */
if (unlikely(!netif_is_l3_master(dev) && !netif_has_l3_rx_handler(dev)))
goto drop;
if (unlikely(!dev->l3mdev_ops->l3mdev_l3_rcv))
goto drop;
/* the decap packet IPv4/IPv6 does not come with any mac header info.
* We must unset the mac header to allow the VRF device to rebuild it,
* just in case there is a sniffer attached on the device.
*/
skb_unset_mac_header(skb);
skb = dev->l3mdev_ops->l3mdev_l3_rcv(dev, skb, family);
if (!skb)
/* the skb buffer was consumed by the handler */
return NULL;
/* when a packet is received by a VRF or by one of its slaves, the
* master device reference is set into the skb.
*/
if (unlikely(skb->dev != dev || skb->skb_iif != dev->ifindex))
goto drop;
return skb;
drop:
kfree_skb(skb);
return ERR_PTR(-EINVAL);
}
static struct net_device *end_dt_get_vrf_rcu(struct sk_buff *skb,
struct seg6_end_dt_info *info)
{
int vrf_ifindex = info->vrf_ifindex;
struct net *net = info->net;
if (unlikely(vrf_ifindex < 0))
goto error;
if (unlikely(!net_eq(dev_net(skb->dev), net)))
goto error;
return dev_get_by_index_rcu(net, vrf_ifindex);
error:
return NULL;
}
static struct sk_buff *end_dt_vrf_core(struct sk_buff *skb,
seg6: add support for SRv6 End.DT46 Behavior IETF RFC 8986 [1] includes the definition of SRv6 End.DT4, End.DT6, and End.DT46 Behaviors. The current SRv6 code in the Linux kernel only implements End.DT4 and End.DT6 which can be used respectively to support IPv4-in-IPv6 and IPv6-in-IPv6 VPNs. With End.DT4 and End.DT6 it is not possible to create a single SRv6 VPN tunnel to carry both IPv4 and IPv6 traffic. The proposed End.DT46 implementation is meant to support the decapsulation of IPv4 and IPv6 traffic coming from a single SRv6 tunnel. The implementation of the SRv6 End.DT46 Behavior in the Linux kernel greatly simplifies the setup and operations of SRv6 VPNs. The SRv6 End.DT46 Behavior leverages the infrastructure of SRv6 End.DT{4,6} Behaviors implemented so far, because it makes use of a VRF device in order to force the routing lookup into the associated routing table. To make the End.DT46 work properly, it must be guaranteed that the routing table used for routing lookup operations is bound to one and only one VRF during the tunnel creation. Such constraint has to be enforced by enabling the VRF strict_mode sysctl parameter, i.e.: $ sysctl -wq net.vrf.strict_mode=1 Note that the same approach is used for the SRv6 End.DT4 Behavior and for the End.DT6 Behavior in VRF mode. The command used to instantiate an SRv6 End.DT46 Behavior is straightforward, i.e.: $ ip -6 route add 2001:db8::1 encap seg6local action End.DT46 vrftable 100 dev vrf100. [1] https://www.rfc-editor.org/rfc/rfc8986.html#name-enddt46-decapsulation-and-s ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Performance and impact of SRv6 End.DT46 Behavior on the SRv6 Networking ======================================================================= This patch aims to add the SRv6 End.DT46 Behavior with minimal impact on the performance of SRv6 End.DT4 and End.DT6 Behaviors. In order to verify this, we tested the performance of the newly introduced SRv6 End.DT46 Behavior and compared it with the performance of SRv6 End.DT{4,6} Behaviors, considering both the patched kernel and the kernel before applying the End.DT46 patch (referred to as vanilla kernel). In details, the following decapsulation scenarios were considered: 1.a) IPv6 traffic in SRv6 End.DT46 Behavior on patched kernel; 1.b) IPv4 traffic in SRv6 End.DT46 Behavior on patched kernel; 2.a) SRv6 End.DT6 Behavior (VRF mode) on patched kernel; 2.b) SRv6 End.DT4 Behavior on patched kernel; 3.a) SRv6 End.DT6 Behavior (VRF mode) on vanilla kernel (without the End.DT46 patch); 3.b) SRv6 End.DT4 Behavior on vanilla kernel (without the End.DT46 patch). All tests were performed on a testbed deployed on the CloudLab [2] facilities. We considered IPv{4,6} traffic handled by a single core (at 2.4 GHz on a Xeon(R) CPU E5-2630 v3) on kernel 5.13-rc1 using packets of size ~ 100 bytes. Scenario (1.a): average 684.70 kpps; std. dev. 0.7 kpps; Scenario (1.b): average 711.69 kpps; std. dev. 1.2 kpps; Scenario (2.a): average 690.70 kpps; std. dev. 1.2 kpps; Scenario (2.b): average 722.22 kpps; std. dev. 1.7 kpps; Scenario (3.a): average 690.02 kpps; std. dev. 2.6 kpps; Scenario (3.b): average 721.91 kpps; std. dev. 1.2 kpps; Considering the results for the patched kernel (1.a, 1.b, 2.a, 2.b) we observe that the performance degradation incurred in using End.DT46 rather than End.DT6 and End.DT4 respectively for IPv6 and IPv4 traffic is minimal, around 0.9% and 1.5%. Such very minimal performance degradation is the price to be paid if one prefers to use a single tunnel capable of handling both types of traffic (IPv4 and IPv6). Comparing the results for End.DT4 and End.DT6 under the patched and the vanilla kernel (2.a, 2.b, 3.a, 3.b) we observe that the introduction of the End.DT46 patch has no impact on the performance of End.DT4 and End.DT6. [2] https://www.cloudlab.us Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-17 20:16:44 +03:00
struct seg6_local_lwt *slwt, u16 family)
seg6: add support for the SRv6 End.DT4 behavior SRv6 End.DT4 is defined in the SRv6 Network Programming [1]. The SRv6 End.DT4 is used to implement IPv4 L3VPN use-cases in multi-tenants environments. It decapsulates the received packets and it performs IPv4 routing lookup in the routing table of the tenant. The SRv6 End.DT4 Linux implementation leverages a VRF device in order to force the routing lookup into the associated routing table. To make the End.DT4 work properly, it must be guaranteed that the routing table used for routing lookup operations is bound to one and only one VRF during the tunnel creation. Such constraint has to be enforced by enabling the VRF strict_mode sysctl parameter, i.e: $ sysctl -wq net.vrf.strict_mode=1. At JANOG44, LINE corporation presented their multi-tenant DC architecture using SRv6 [2]. In the slides, they reported that the Linux kernel is missing the support of SRv6 End.DT4 behavior. The SRv6 End.DT4 behavior can be instantiated using a command similar to the following: $ ip route add 2001:db8::1 encap seg6local action End.DT4 vrftable 100 dev eth0 We introduce the "vrftable" extension in iproute2 in a following patch. [1] https://tools.ietf.org/html/draft-ietf-spring-srv6-network-programming [2] https://speakerdeck.com/line_developers/line-data-center-networking-with-srv6 Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:14 +03:00
{
struct seg6_end_dt_info *info = &slwt->dt_info;
struct net_device *vrf;
seg6: add support for SRv6 End.DT46 Behavior IETF RFC 8986 [1] includes the definition of SRv6 End.DT4, End.DT6, and End.DT46 Behaviors. The current SRv6 code in the Linux kernel only implements End.DT4 and End.DT6 which can be used respectively to support IPv4-in-IPv6 and IPv6-in-IPv6 VPNs. With End.DT4 and End.DT6 it is not possible to create a single SRv6 VPN tunnel to carry both IPv4 and IPv6 traffic. The proposed End.DT46 implementation is meant to support the decapsulation of IPv4 and IPv6 traffic coming from a single SRv6 tunnel. The implementation of the SRv6 End.DT46 Behavior in the Linux kernel greatly simplifies the setup and operations of SRv6 VPNs. The SRv6 End.DT46 Behavior leverages the infrastructure of SRv6 End.DT{4,6} Behaviors implemented so far, because it makes use of a VRF device in order to force the routing lookup into the associated routing table. To make the End.DT46 work properly, it must be guaranteed that the routing table used for routing lookup operations is bound to one and only one VRF during the tunnel creation. Such constraint has to be enforced by enabling the VRF strict_mode sysctl parameter, i.e.: $ sysctl -wq net.vrf.strict_mode=1 Note that the same approach is used for the SRv6 End.DT4 Behavior and for the End.DT6 Behavior in VRF mode. The command used to instantiate an SRv6 End.DT46 Behavior is straightforward, i.e.: $ ip -6 route add 2001:db8::1 encap seg6local action End.DT46 vrftable 100 dev vrf100. [1] https://www.rfc-editor.org/rfc/rfc8986.html#name-enddt46-decapsulation-and-s ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Performance and impact of SRv6 End.DT46 Behavior on the SRv6 Networking ======================================================================= This patch aims to add the SRv6 End.DT46 Behavior with minimal impact on the performance of SRv6 End.DT4 and End.DT6 Behaviors. In order to verify this, we tested the performance of the newly introduced SRv6 End.DT46 Behavior and compared it with the performance of SRv6 End.DT{4,6} Behaviors, considering both the patched kernel and the kernel before applying the End.DT46 patch (referred to as vanilla kernel). In details, the following decapsulation scenarios were considered: 1.a) IPv6 traffic in SRv6 End.DT46 Behavior on patched kernel; 1.b) IPv4 traffic in SRv6 End.DT46 Behavior on patched kernel; 2.a) SRv6 End.DT6 Behavior (VRF mode) on patched kernel; 2.b) SRv6 End.DT4 Behavior on patched kernel; 3.a) SRv6 End.DT6 Behavior (VRF mode) on vanilla kernel (without the End.DT46 patch); 3.b) SRv6 End.DT4 Behavior on vanilla kernel (without the End.DT46 patch). All tests were performed on a testbed deployed on the CloudLab [2] facilities. We considered IPv{4,6} traffic handled by a single core (at 2.4 GHz on a Xeon(R) CPU E5-2630 v3) on kernel 5.13-rc1 using packets of size ~ 100 bytes. Scenario (1.a): average 684.70 kpps; std. dev. 0.7 kpps; Scenario (1.b): average 711.69 kpps; std. dev. 1.2 kpps; Scenario (2.a): average 690.70 kpps; std. dev. 1.2 kpps; Scenario (2.b): average 722.22 kpps; std. dev. 1.7 kpps; Scenario (3.a): average 690.02 kpps; std. dev. 2.6 kpps; Scenario (3.b): average 721.91 kpps; std. dev. 1.2 kpps; Considering the results for the patched kernel (1.a, 1.b, 2.a, 2.b) we observe that the performance degradation incurred in using End.DT46 rather than End.DT6 and End.DT4 respectively for IPv6 and IPv4 traffic is minimal, around 0.9% and 1.5%. Such very minimal performance degradation is the price to be paid if one prefers to use a single tunnel capable of handling both types of traffic (IPv4 and IPv6). Comparing the results for End.DT4 and End.DT6 under the patched and the vanilla kernel (2.a, 2.b, 3.a, 3.b) we observe that the introduction of the End.DT46 patch has no impact on the performance of End.DT4 and End.DT6. [2] https://www.cloudlab.us Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-17 20:16:44 +03:00
__be16 protocol;
int hdrlen;
seg6: add support for the SRv6 End.DT4 behavior SRv6 End.DT4 is defined in the SRv6 Network Programming [1]. The SRv6 End.DT4 is used to implement IPv4 L3VPN use-cases in multi-tenants environments. It decapsulates the received packets and it performs IPv4 routing lookup in the routing table of the tenant. The SRv6 End.DT4 Linux implementation leverages a VRF device in order to force the routing lookup into the associated routing table. To make the End.DT4 work properly, it must be guaranteed that the routing table used for routing lookup operations is bound to one and only one VRF during the tunnel creation. Such constraint has to be enforced by enabling the VRF strict_mode sysctl parameter, i.e: $ sysctl -wq net.vrf.strict_mode=1. At JANOG44, LINE corporation presented their multi-tenant DC architecture using SRv6 [2]. In the slides, they reported that the Linux kernel is missing the support of SRv6 End.DT4 behavior. The SRv6 End.DT4 behavior can be instantiated using a command similar to the following: $ ip route add 2001:db8::1 encap seg6local action End.DT4 vrftable 100 dev eth0 We introduce the "vrftable" extension in iproute2 in a following patch. [1] https://tools.ietf.org/html/draft-ietf-spring-srv6-network-programming [2] https://speakerdeck.com/line_developers/line-data-center-networking-with-srv6 Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:14 +03:00
vrf = end_dt_get_vrf_rcu(skb, info);
if (unlikely(!vrf))
goto drop;
seg6: add support for SRv6 End.DT46 Behavior IETF RFC 8986 [1] includes the definition of SRv6 End.DT4, End.DT6, and End.DT46 Behaviors. The current SRv6 code in the Linux kernel only implements End.DT4 and End.DT6 which can be used respectively to support IPv4-in-IPv6 and IPv6-in-IPv6 VPNs. With End.DT4 and End.DT6 it is not possible to create a single SRv6 VPN tunnel to carry both IPv4 and IPv6 traffic. The proposed End.DT46 implementation is meant to support the decapsulation of IPv4 and IPv6 traffic coming from a single SRv6 tunnel. The implementation of the SRv6 End.DT46 Behavior in the Linux kernel greatly simplifies the setup and operations of SRv6 VPNs. The SRv6 End.DT46 Behavior leverages the infrastructure of SRv6 End.DT{4,6} Behaviors implemented so far, because it makes use of a VRF device in order to force the routing lookup into the associated routing table. To make the End.DT46 work properly, it must be guaranteed that the routing table used for routing lookup operations is bound to one and only one VRF during the tunnel creation. Such constraint has to be enforced by enabling the VRF strict_mode sysctl parameter, i.e.: $ sysctl -wq net.vrf.strict_mode=1 Note that the same approach is used for the SRv6 End.DT4 Behavior and for the End.DT6 Behavior in VRF mode. The command used to instantiate an SRv6 End.DT46 Behavior is straightforward, i.e.: $ ip -6 route add 2001:db8::1 encap seg6local action End.DT46 vrftable 100 dev vrf100. [1] https://www.rfc-editor.org/rfc/rfc8986.html#name-enddt46-decapsulation-and-s ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Performance and impact of SRv6 End.DT46 Behavior on the SRv6 Networking ======================================================================= This patch aims to add the SRv6 End.DT46 Behavior with minimal impact on the performance of SRv6 End.DT4 and End.DT6 Behaviors. In order to verify this, we tested the performance of the newly introduced SRv6 End.DT46 Behavior and compared it with the performance of SRv6 End.DT{4,6} Behaviors, considering both the patched kernel and the kernel before applying the End.DT46 patch (referred to as vanilla kernel). In details, the following decapsulation scenarios were considered: 1.a) IPv6 traffic in SRv6 End.DT46 Behavior on patched kernel; 1.b) IPv4 traffic in SRv6 End.DT46 Behavior on patched kernel; 2.a) SRv6 End.DT6 Behavior (VRF mode) on patched kernel; 2.b) SRv6 End.DT4 Behavior on patched kernel; 3.a) SRv6 End.DT6 Behavior (VRF mode) on vanilla kernel (without the End.DT46 patch); 3.b) SRv6 End.DT4 Behavior on vanilla kernel (without the End.DT46 patch). All tests were performed on a testbed deployed on the CloudLab [2] facilities. We considered IPv{4,6} traffic handled by a single core (at 2.4 GHz on a Xeon(R) CPU E5-2630 v3) on kernel 5.13-rc1 using packets of size ~ 100 bytes. Scenario (1.a): average 684.70 kpps; std. dev. 0.7 kpps; Scenario (1.b): average 711.69 kpps; std. dev. 1.2 kpps; Scenario (2.a): average 690.70 kpps; std. dev. 1.2 kpps; Scenario (2.b): average 722.22 kpps; std. dev. 1.7 kpps; Scenario (3.a): average 690.02 kpps; std. dev. 2.6 kpps; Scenario (3.b): average 721.91 kpps; std. dev. 1.2 kpps; Considering the results for the patched kernel (1.a, 1.b, 2.a, 2.b) we observe that the performance degradation incurred in using End.DT46 rather than End.DT6 and End.DT4 respectively for IPv6 and IPv4 traffic is minimal, around 0.9% and 1.5%. Such very minimal performance degradation is the price to be paid if one prefers to use a single tunnel capable of handling both types of traffic (IPv4 and IPv6). Comparing the results for End.DT4 and End.DT6 under the patched and the vanilla kernel (2.a, 2.b, 3.a, 3.b) we observe that the introduction of the End.DT46 patch has no impact on the performance of End.DT4 and End.DT6. [2] https://www.cloudlab.us Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-17 20:16:44 +03:00
switch (family) {
case AF_INET:
protocol = htons(ETH_P_IP);
hdrlen = sizeof(struct iphdr);
break;
case AF_INET6:
protocol = htons(ETH_P_IPV6);
hdrlen = sizeof(struct ipv6hdr);
break;
case AF_UNSPEC:
fallthrough;
default:
goto drop;
}
if (unlikely(info->family != AF_UNSPEC && info->family != family)) {
pr_warn_once("seg6local: SRv6 End.DT* family mismatch");
goto drop;
}
skb->protocol = protocol;
seg6: add support for the SRv6 End.DT4 behavior SRv6 End.DT4 is defined in the SRv6 Network Programming [1]. The SRv6 End.DT4 is used to implement IPv4 L3VPN use-cases in multi-tenants environments. It decapsulates the received packets and it performs IPv4 routing lookup in the routing table of the tenant. The SRv6 End.DT4 Linux implementation leverages a VRF device in order to force the routing lookup into the associated routing table. To make the End.DT4 work properly, it must be guaranteed that the routing table used for routing lookup operations is bound to one and only one VRF during the tunnel creation. Such constraint has to be enforced by enabling the VRF strict_mode sysctl parameter, i.e: $ sysctl -wq net.vrf.strict_mode=1. At JANOG44, LINE corporation presented their multi-tenant DC architecture using SRv6 [2]. In the slides, they reported that the Linux kernel is missing the support of SRv6 End.DT4 behavior. The SRv6 End.DT4 behavior can be instantiated using a command similar to the following: $ ip route add 2001:db8::1 encap seg6local action End.DT4 vrftable 100 dev eth0 We introduce the "vrftable" extension in iproute2 in a following patch. [1] https://tools.ietf.org/html/draft-ietf-spring-srv6-network-programming [2] https://speakerdeck.com/line_developers/line-data-center-networking-with-srv6 Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:14 +03:00
skb_dst_drop(skb);
seg6: add support for SRv6 End.DT46 Behavior IETF RFC 8986 [1] includes the definition of SRv6 End.DT4, End.DT6, and End.DT46 Behaviors. The current SRv6 code in the Linux kernel only implements End.DT4 and End.DT6 which can be used respectively to support IPv4-in-IPv6 and IPv6-in-IPv6 VPNs. With End.DT4 and End.DT6 it is not possible to create a single SRv6 VPN tunnel to carry both IPv4 and IPv6 traffic. The proposed End.DT46 implementation is meant to support the decapsulation of IPv4 and IPv6 traffic coming from a single SRv6 tunnel. The implementation of the SRv6 End.DT46 Behavior in the Linux kernel greatly simplifies the setup and operations of SRv6 VPNs. The SRv6 End.DT46 Behavior leverages the infrastructure of SRv6 End.DT{4,6} Behaviors implemented so far, because it makes use of a VRF device in order to force the routing lookup into the associated routing table. To make the End.DT46 work properly, it must be guaranteed that the routing table used for routing lookup operations is bound to one and only one VRF during the tunnel creation. Such constraint has to be enforced by enabling the VRF strict_mode sysctl parameter, i.e.: $ sysctl -wq net.vrf.strict_mode=1 Note that the same approach is used for the SRv6 End.DT4 Behavior and for the End.DT6 Behavior in VRF mode. The command used to instantiate an SRv6 End.DT46 Behavior is straightforward, i.e.: $ ip -6 route add 2001:db8::1 encap seg6local action End.DT46 vrftable 100 dev vrf100. [1] https://www.rfc-editor.org/rfc/rfc8986.html#name-enddt46-decapsulation-and-s ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Performance and impact of SRv6 End.DT46 Behavior on the SRv6 Networking ======================================================================= This patch aims to add the SRv6 End.DT46 Behavior with minimal impact on the performance of SRv6 End.DT4 and End.DT6 Behaviors. In order to verify this, we tested the performance of the newly introduced SRv6 End.DT46 Behavior and compared it with the performance of SRv6 End.DT{4,6} Behaviors, considering both the patched kernel and the kernel before applying the End.DT46 patch (referred to as vanilla kernel). In details, the following decapsulation scenarios were considered: 1.a) IPv6 traffic in SRv6 End.DT46 Behavior on patched kernel; 1.b) IPv4 traffic in SRv6 End.DT46 Behavior on patched kernel; 2.a) SRv6 End.DT6 Behavior (VRF mode) on patched kernel; 2.b) SRv6 End.DT4 Behavior on patched kernel; 3.a) SRv6 End.DT6 Behavior (VRF mode) on vanilla kernel (without the End.DT46 patch); 3.b) SRv6 End.DT4 Behavior on vanilla kernel (without the End.DT46 patch). All tests were performed on a testbed deployed on the CloudLab [2] facilities. We considered IPv{4,6} traffic handled by a single core (at 2.4 GHz on a Xeon(R) CPU E5-2630 v3) on kernel 5.13-rc1 using packets of size ~ 100 bytes. Scenario (1.a): average 684.70 kpps; std. dev. 0.7 kpps; Scenario (1.b): average 711.69 kpps; std. dev. 1.2 kpps; Scenario (2.a): average 690.70 kpps; std. dev. 1.2 kpps; Scenario (2.b): average 722.22 kpps; std. dev. 1.7 kpps; Scenario (3.a): average 690.02 kpps; std. dev. 2.6 kpps; Scenario (3.b): average 721.91 kpps; std. dev. 1.2 kpps; Considering the results for the patched kernel (1.a, 1.b, 2.a, 2.b) we observe that the performance degradation incurred in using End.DT46 rather than End.DT6 and End.DT4 respectively for IPv6 and IPv4 traffic is minimal, around 0.9% and 1.5%. Such very minimal performance degradation is the price to be paid if one prefers to use a single tunnel capable of handling both types of traffic (IPv4 and IPv6). Comparing the results for End.DT4 and End.DT6 under the patched and the vanilla kernel (2.a, 2.b, 3.a, 3.b) we observe that the introduction of the End.DT46 patch has no impact on the performance of End.DT4 and End.DT6. [2] https://www.cloudlab.us Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-17 20:16:44 +03:00
skb_set_transport_header(skb, hdrlen);
netfilter: add netfilter hooks to SRv6 data plane This patch introduces netfilter hooks for solving the problem that conntrack couldn't record both inner flows and outer flows. This patch also introduces a new sysctl toggle for enabling lightweight tunnel netfilter hooks. Signed-off-by: Ryoga Saito <contact@proelbtn.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-08-17 11:39:37 +03:00
nf_reset_ct(skb);
seg6: add support for the SRv6 End.DT4 behavior SRv6 End.DT4 is defined in the SRv6 Network Programming [1]. The SRv6 End.DT4 is used to implement IPv4 L3VPN use-cases in multi-tenants environments. It decapsulates the received packets and it performs IPv4 routing lookup in the routing table of the tenant. The SRv6 End.DT4 Linux implementation leverages a VRF device in order to force the routing lookup into the associated routing table. To make the End.DT4 work properly, it must be guaranteed that the routing table used for routing lookup operations is bound to one and only one VRF during the tunnel creation. Such constraint has to be enforced by enabling the VRF strict_mode sysctl parameter, i.e: $ sysctl -wq net.vrf.strict_mode=1. At JANOG44, LINE corporation presented their multi-tenant DC architecture using SRv6 [2]. In the slides, they reported that the Linux kernel is missing the support of SRv6 End.DT4 behavior. The SRv6 End.DT4 behavior can be instantiated using a command similar to the following: $ ip route add 2001:db8::1 encap seg6local action End.DT4 vrftable 100 dev eth0 We introduce the "vrftable" extension in iproute2 in a following patch. [1] https://tools.ietf.org/html/draft-ietf-spring-srv6-network-programming [2] https://speakerdeck.com/line_developers/line-data-center-networking-with-srv6 Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:14 +03:00
seg6: add support for SRv6 End.DT46 Behavior IETF RFC 8986 [1] includes the definition of SRv6 End.DT4, End.DT6, and End.DT46 Behaviors. The current SRv6 code in the Linux kernel only implements End.DT4 and End.DT6 which can be used respectively to support IPv4-in-IPv6 and IPv6-in-IPv6 VPNs. With End.DT4 and End.DT6 it is not possible to create a single SRv6 VPN tunnel to carry both IPv4 and IPv6 traffic. The proposed End.DT46 implementation is meant to support the decapsulation of IPv4 and IPv6 traffic coming from a single SRv6 tunnel. The implementation of the SRv6 End.DT46 Behavior in the Linux kernel greatly simplifies the setup and operations of SRv6 VPNs. The SRv6 End.DT46 Behavior leverages the infrastructure of SRv6 End.DT{4,6} Behaviors implemented so far, because it makes use of a VRF device in order to force the routing lookup into the associated routing table. To make the End.DT46 work properly, it must be guaranteed that the routing table used for routing lookup operations is bound to one and only one VRF during the tunnel creation. Such constraint has to be enforced by enabling the VRF strict_mode sysctl parameter, i.e.: $ sysctl -wq net.vrf.strict_mode=1 Note that the same approach is used for the SRv6 End.DT4 Behavior and for the End.DT6 Behavior in VRF mode. The command used to instantiate an SRv6 End.DT46 Behavior is straightforward, i.e.: $ ip -6 route add 2001:db8::1 encap seg6local action End.DT46 vrftable 100 dev vrf100. [1] https://www.rfc-editor.org/rfc/rfc8986.html#name-enddt46-decapsulation-and-s ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Performance and impact of SRv6 End.DT46 Behavior on the SRv6 Networking ======================================================================= This patch aims to add the SRv6 End.DT46 Behavior with minimal impact on the performance of SRv6 End.DT4 and End.DT6 Behaviors. In order to verify this, we tested the performance of the newly introduced SRv6 End.DT46 Behavior and compared it with the performance of SRv6 End.DT{4,6} Behaviors, considering both the patched kernel and the kernel before applying the End.DT46 patch (referred to as vanilla kernel). In details, the following decapsulation scenarios were considered: 1.a) IPv6 traffic in SRv6 End.DT46 Behavior on patched kernel; 1.b) IPv4 traffic in SRv6 End.DT46 Behavior on patched kernel; 2.a) SRv6 End.DT6 Behavior (VRF mode) on patched kernel; 2.b) SRv6 End.DT4 Behavior on patched kernel; 3.a) SRv6 End.DT6 Behavior (VRF mode) on vanilla kernel (without the End.DT46 patch); 3.b) SRv6 End.DT4 Behavior on vanilla kernel (without the End.DT46 patch). All tests were performed on a testbed deployed on the CloudLab [2] facilities. We considered IPv{4,6} traffic handled by a single core (at 2.4 GHz on a Xeon(R) CPU E5-2630 v3) on kernel 5.13-rc1 using packets of size ~ 100 bytes. Scenario (1.a): average 684.70 kpps; std. dev. 0.7 kpps; Scenario (1.b): average 711.69 kpps; std. dev. 1.2 kpps; Scenario (2.a): average 690.70 kpps; std. dev. 1.2 kpps; Scenario (2.b): average 722.22 kpps; std. dev. 1.7 kpps; Scenario (3.a): average 690.02 kpps; std. dev. 2.6 kpps; Scenario (3.b): average 721.91 kpps; std. dev. 1.2 kpps; Considering the results for the patched kernel (1.a, 1.b, 2.a, 2.b) we observe that the performance degradation incurred in using End.DT46 rather than End.DT6 and End.DT4 respectively for IPv6 and IPv4 traffic is minimal, around 0.9% and 1.5%. Such very minimal performance degradation is the price to be paid if one prefers to use a single tunnel capable of handling both types of traffic (IPv4 and IPv6). Comparing the results for End.DT4 and End.DT6 under the patched and the vanilla kernel (2.a, 2.b, 3.a, 3.b) we observe that the introduction of the End.DT46 patch has no impact on the performance of End.DT4 and End.DT6. [2] https://www.cloudlab.us Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-17 20:16:44 +03:00
return end_dt_vrf_rcv(skb, family, vrf);
seg6: add support for the SRv6 End.DT4 behavior SRv6 End.DT4 is defined in the SRv6 Network Programming [1]. The SRv6 End.DT4 is used to implement IPv4 L3VPN use-cases in multi-tenants environments. It decapsulates the received packets and it performs IPv4 routing lookup in the routing table of the tenant. The SRv6 End.DT4 Linux implementation leverages a VRF device in order to force the routing lookup into the associated routing table. To make the End.DT4 work properly, it must be guaranteed that the routing table used for routing lookup operations is bound to one and only one VRF during the tunnel creation. Such constraint has to be enforced by enabling the VRF strict_mode sysctl parameter, i.e: $ sysctl -wq net.vrf.strict_mode=1. At JANOG44, LINE corporation presented their multi-tenant DC architecture using SRv6 [2]. In the slides, they reported that the Linux kernel is missing the support of SRv6 End.DT4 behavior. The SRv6 End.DT4 behavior can be instantiated using a command similar to the following: $ ip route add 2001:db8::1 encap seg6local action End.DT4 vrftable 100 dev eth0 We introduce the "vrftable" extension in iproute2 in a following patch. [1] https://tools.ietf.org/html/draft-ietf-spring-srv6-network-programming [2] https://speakerdeck.com/line_developers/line-data-center-networking-with-srv6 Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:14 +03:00
drop:
kfree_skb(skb);
return ERR_PTR(-EINVAL);
}
static int input_action_end_dt4(struct sk_buff *skb,
struct seg6_local_lwt *slwt)
{
struct iphdr *iph;
int err;
if (!decap_and_validate(skb, IPPROTO_IPIP))
goto drop;
if (!pskb_may_pull(skb, sizeof(struct iphdr)))
goto drop;
seg6: add support for SRv6 End.DT46 Behavior IETF RFC 8986 [1] includes the definition of SRv6 End.DT4, End.DT6, and End.DT46 Behaviors. The current SRv6 code in the Linux kernel only implements End.DT4 and End.DT6 which can be used respectively to support IPv4-in-IPv6 and IPv6-in-IPv6 VPNs. With End.DT4 and End.DT6 it is not possible to create a single SRv6 VPN tunnel to carry both IPv4 and IPv6 traffic. The proposed End.DT46 implementation is meant to support the decapsulation of IPv4 and IPv6 traffic coming from a single SRv6 tunnel. The implementation of the SRv6 End.DT46 Behavior in the Linux kernel greatly simplifies the setup and operations of SRv6 VPNs. The SRv6 End.DT46 Behavior leverages the infrastructure of SRv6 End.DT{4,6} Behaviors implemented so far, because it makes use of a VRF device in order to force the routing lookup into the associated routing table. To make the End.DT46 work properly, it must be guaranteed that the routing table used for routing lookup operations is bound to one and only one VRF during the tunnel creation. Such constraint has to be enforced by enabling the VRF strict_mode sysctl parameter, i.e.: $ sysctl -wq net.vrf.strict_mode=1 Note that the same approach is used for the SRv6 End.DT4 Behavior and for the End.DT6 Behavior in VRF mode. The command used to instantiate an SRv6 End.DT46 Behavior is straightforward, i.e.: $ ip -6 route add 2001:db8::1 encap seg6local action End.DT46 vrftable 100 dev vrf100. [1] https://www.rfc-editor.org/rfc/rfc8986.html#name-enddt46-decapsulation-and-s ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Performance and impact of SRv6 End.DT46 Behavior on the SRv6 Networking ======================================================================= This patch aims to add the SRv6 End.DT46 Behavior with minimal impact on the performance of SRv6 End.DT4 and End.DT6 Behaviors. In order to verify this, we tested the performance of the newly introduced SRv6 End.DT46 Behavior and compared it with the performance of SRv6 End.DT{4,6} Behaviors, considering both the patched kernel and the kernel before applying the End.DT46 patch (referred to as vanilla kernel). In details, the following decapsulation scenarios were considered: 1.a) IPv6 traffic in SRv6 End.DT46 Behavior on patched kernel; 1.b) IPv4 traffic in SRv6 End.DT46 Behavior on patched kernel; 2.a) SRv6 End.DT6 Behavior (VRF mode) on patched kernel; 2.b) SRv6 End.DT4 Behavior on patched kernel; 3.a) SRv6 End.DT6 Behavior (VRF mode) on vanilla kernel (without the End.DT46 patch); 3.b) SRv6 End.DT4 Behavior on vanilla kernel (without the End.DT46 patch). All tests were performed on a testbed deployed on the CloudLab [2] facilities. We considered IPv{4,6} traffic handled by a single core (at 2.4 GHz on a Xeon(R) CPU E5-2630 v3) on kernel 5.13-rc1 using packets of size ~ 100 bytes. Scenario (1.a): average 684.70 kpps; std. dev. 0.7 kpps; Scenario (1.b): average 711.69 kpps; std. dev. 1.2 kpps; Scenario (2.a): average 690.70 kpps; std. dev. 1.2 kpps; Scenario (2.b): average 722.22 kpps; std. dev. 1.7 kpps; Scenario (3.a): average 690.02 kpps; std. dev. 2.6 kpps; Scenario (3.b): average 721.91 kpps; std. dev. 1.2 kpps; Considering the results for the patched kernel (1.a, 1.b, 2.a, 2.b) we observe that the performance degradation incurred in using End.DT46 rather than End.DT6 and End.DT4 respectively for IPv6 and IPv4 traffic is minimal, around 0.9% and 1.5%. Such very minimal performance degradation is the price to be paid if one prefers to use a single tunnel capable of handling both types of traffic (IPv4 and IPv6). Comparing the results for End.DT4 and End.DT6 under the patched and the vanilla kernel (2.a, 2.b, 3.a, 3.b) we observe that the introduction of the End.DT46 patch has no impact on the performance of End.DT4 and End.DT6. [2] https://www.cloudlab.us Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-17 20:16:44 +03:00
skb = end_dt_vrf_core(skb, slwt, AF_INET);
seg6: add support for the SRv6 End.DT4 behavior SRv6 End.DT4 is defined in the SRv6 Network Programming [1]. The SRv6 End.DT4 is used to implement IPv4 L3VPN use-cases in multi-tenants environments. It decapsulates the received packets and it performs IPv4 routing lookup in the routing table of the tenant. The SRv6 End.DT4 Linux implementation leverages a VRF device in order to force the routing lookup into the associated routing table. To make the End.DT4 work properly, it must be guaranteed that the routing table used for routing lookup operations is bound to one and only one VRF during the tunnel creation. Such constraint has to be enforced by enabling the VRF strict_mode sysctl parameter, i.e: $ sysctl -wq net.vrf.strict_mode=1. At JANOG44, LINE corporation presented their multi-tenant DC architecture using SRv6 [2]. In the slides, they reported that the Linux kernel is missing the support of SRv6 End.DT4 behavior. The SRv6 End.DT4 behavior can be instantiated using a command similar to the following: $ ip route add 2001:db8::1 encap seg6local action End.DT4 vrftable 100 dev eth0 We introduce the "vrftable" extension in iproute2 in a following patch. [1] https://tools.ietf.org/html/draft-ietf-spring-srv6-network-programming [2] https://speakerdeck.com/line_developers/line-data-center-networking-with-srv6 Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:14 +03:00
if (!skb)
/* packet has been processed and consumed by the VRF */
return 0;
if (IS_ERR(skb))
return PTR_ERR(skb);
iph = ip_hdr(skb);
err = ip_route_input(skb, iph->daddr, iph->saddr, 0, skb->dev);
if (unlikely(err))
goto drop;
return dst_input(skb);
drop:
kfree_skb(skb);
return -EINVAL;
}
static int seg6_end_dt4_build(struct seg6_local_lwt *slwt, const void *cfg,
struct netlink_ext_ack *extack)
{
return __seg6_end_dt_vrf_build(slwt, cfg, AF_INET, extack);
}
seg6: add VRF support for SRv6 End.DT6 behavior SRv6 End.DT6 is defined in the SRv6 Network Programming [1]. The Linux kernel already offers an implementation of the SRv6 End.DT6 behavior which permits IPv6 L3 VPNs over SRv6 networks. This implementation is not particularly suitable in contexts where we need to deploy IPv6 L3 VPNs among different tenants which share the same network address schemes. The underlying problem lies in the fact that the current version of DT6 (called legacy DT6 from now on) needs a complex configuration to be applied on routers which requires ad-hoc routes and routing policy rules to ensure the correct isolation of tenants. Consequently, a new implementation of DT6 has been introduced with the aim of simplifying the construction of IPv6 L3 VPN services in the multi-tenant environment using SRv6 networks. To accomplish this task, we reused the same VRF infrastructure and SRv6 core components already exploited for implementing the SRv6 End.DT4 behavior. Currently the two End.DT6 implementations coexist seamlessly and can be used depending on the context and the user preferences. So, in order to support both versions of DT6 a new attribute (vrftable) has been introduced which allows us to differentiate the implementation of the behavior to be used. A SRv6 End.DT6 legacy behavior is still instantiated using a command like the following one: $ ip -6 route add 2001:db8::1 encap seg6local action End.DT6 table 100 dev eth0 While to instantiate the SRv6 End.DT6 in VRF mode, the command is still pretty straight forward: $ ip -6 route add 2001:db8::1 encap seg6local action End.DT6 vrftable 100 dev eth0. Obviously as in the case of SRv6 End.DT4, the VRF strict_mode parameter must be set (net.vrf.strict_mode=1) and the VRF associated with table 100 must exist. Please note that the instances of SRv6 End.DT6 legacy and End.DT6 VRF mode can coexist in the same system/configuration without problems. [1] https://tools.ietf.org/html/draft-ietf-spring-srv6-network-programming Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:15 +03:00
static enum
seg6_end_dt_mode seg6_end_dt6_parse_mode(struct seg6_local_lwt *slwt)
{
unsigned long parsed_optattrs = slwt->parsed_optattrs;
bool legacy, vrfmode;
seg6: fool-proof the processing of SRv6 behavior attributes The set of required attributes for a given SRv6 behavior is identified using a bitmap stored in an unsigned long, since the initial design of SRv6 networking in Linux. Recently the same approach has been used for identifying the optional attributes. However, the number of attributes supported by SRv6 behaviors depends on the size of the unsigned long type which changes with the architecture. Indeed, on a 64-bit architecture, an SRv6 behavior can support up to 64 attributes while on a 32-bit architecture it can support at most 32 attributes. To fool-proof the processing of SRv6 behaviors we verify, at compile time, that the set of all supported SRv6 attributes can be encoded into a bitmap stored in an unsigned long. Otherwise, kernel build fails forcing developers to reconsider adding a new attribute or extend the total number of supported attributes by the SRv6 behaviors. Moreover, we replace all patterns (1 << i) with the macro SEG6_F_ATTR(i) in order to address potential overflow issues caused by 32-bit signed arithmetic. Thanks to Colin Ian King for catching the overflow problem, providing a solution and inspiring this patch. Thanks to Jakub Kicinski for his useful suggestions during the design of this patch. v2: - remove the SEG6_LOCAL_MAX_SUPP which is not strictly needed: it can be derived from the unsigned long type. Thanks to David Ahern for pointing it out. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/r/20210206170934.5982-1-andrea.mayer@uniroma2.it Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-02-06 20:09:34 +03:00
legacy = !!(parsed_optattrs & SEG6_F_ATTR(SEG6_LOCAL_TABLE));
vrfmode = !!(parsed_optattrs & SEG6_F_ATTR(SEG6_LOCAL_VRFTABLE));
seg6: add VRF support for SRv6 End.DT6 behavior SRv6 End.DT6 is defined in the SRv6 Network Programming [1]. The Linux kernel already offers an implementation of the SRv6 End.DT6 behavior which permits IPv6 L3 VPNs over SRv6 networks. This implementation is not particularly suitable in contexts where we need to deploy IPv6 L3 VPNs among different tenants which share the same network address schemes. The underlying problem lies in the fact that the current version of DT6 (called legacy DT6 from now on) needs a complex configuration to be applied on routers which requires ad-hoc routes and routing policy rules to ensure the correct isolation of tenants. Consequently, a new implementation of DT6 has been introduced with the aim of simplifying the construction of IPv6 L3 VPN services in the multi-tenant environment using SRv6 networks. To accomplish this task, we reused the same VRF infrastructure and SRv6 core components already exploited for implementing the SRv6 End.DT4 behavior. Currently the two End.DT6 implementations coexist seamlessly and can be used depending on the context and the user preferences. So, in order to support both versions of DT6 a new attribute (vrftable) has been introduced which allows us to differentiate the implementation of the behavior to be used. A SRv6 End.DT6 legacy behavior is still instantiated using a command like the following one: $ ip -6 route add 2001:db8::1 encap seg6local action End.DT6 table 100 dev eth0 While to instantiate the SRv6 End.DT6 in VRF mode, the command is still pretty straight forward: $ ip -6 route add 2001:db8::1 encap seg6local action End.DT6 vrftable 100 dev eth0. Obviously as in the case of SRv6 End.DT4, the VRF strict_mode parameter must be set (net.vrf.strict_mode=1) and the VRF associated with table 100 must exist. Please note that the instances of SRv6 End.DT6 legacy and End.DT6 VRF mode can coexist in the same system/configuration without problems. [1] https://tools.ietf.org/html/draft-ietf-spring-srv6-network-programming Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:15 +03:00
if (!(legacy ^ vrfmode))
/* both are absent or present: invalid DT6 mode */
return DT_INVALID_MODE;
return legacy ? DT_LEGACY_MODE : DT_VRF_MODE;
}
static enum seg6_end_dt_mode seg6_end_dt6_get_mode(struct seg6_local_lwt *slwt)
{
struct seg6_end_dt_info *info = &slwt->dt_info;
return info->mode;
}
static int seg6_end_dt6_build(struct seg6_local_lwt *slwt, const void *cfg,
struct netlink_ext_ack *extack)
{
enum seg6_end_dt_mode mode = seg6_end_dt6_parse_mode(slwt);
struct seg6_end_dt_info *info = &slwt->dt_info;
switch (mode) {
case DT_LEGACY_MODE:
info->mode = DT_LEGACY_MODE;
return 0;
case DT_VRF_MODE:
return __seg6_end_dt_vrf_build(slwt, cfg, AF_INET6, extack);
default:
NL_SET_ERR_MSG(extack, "table or vrftable must be specified");
return -EINVAL;
}
}
seg6: add support for the SRv6 End.DT4 behavior SRv6 End.DT4 is defined in the SRv6 Network Programming [1]. The SRv6 End.DT4 is used to implement IPv4 L3VPN use-cases in multi-tenants environments. It decapsulates the received packets and it performs IPv4 routing lookup in the routing table of the tenant. The SRv6 End.DT4 Linux implementation leverages a VRF device in order to force the routing lookup into the associated routing table. To make the End.DT4 work properly, it must be guaranteed that the routing table used for routing lookup operations is bound to one and only one VRF during the tunnel creation. Such constraint has to be enforced by enabling the VRF strict_mode sysctl parameter, i.e: $ sysctl -wq net.vrf.strict_mode=1. At JANOG44, LINE corporation presented their multi-tenant DC architecture using SRv6 [2]. In the slides, they reported that the Linux kernel is missing the support of SRv6 End.DT4 behavior. The SRv6 End.DT4 behavior can be instantiated using a command similar to the following: $ ip route add 2001:db8::1 encap seg6local action End.DT4 vrftable 100 dev eth0 We introduce the "vrftable" extension in iproute2 in a following patch. [1] https://tools.ietf.org/html/draft-ietf-spring-srv6-network-programming [2] https://speakerdeck.com/line_developers/line-data-center-networking-with-srv6 Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:14 +03:00
#endif
ipv6: sr: implement additional seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END_T: regular SRH processing and forward to the next-hop looked up in the specified routing table. - SEG6_LOCAL_ACTION_END_DX2: decapsulate an L2 frame and forward it to the specified network interface. - SEG6_LOCAL_ACTION_END_DX4: decapsulate an IPv4 packet and forward it, possibly to the specified next-hop. - SEG6_LOCAL_ACTION_END_DT6: decapsulate an IPv6 packet and forward it to the next-hop looked up in the specified routing table. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 10:58:17 +03:00
static int input_action_end_dt6(struct sk_buff *skb,
struct seg6_local_lwt *slwt)
{
if (!decap_and_validate(skb, IPPROTO_IPV6))
goto drop;
if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
goto drop;
seg6: add VRF support for SRv6 End.DT6 behavior SRv6 End.DT6 is defined in the SRv6 Network Programming [1]. The Linux kernel already offers an implementation of the SRv6 End.DT6 behavior which permits IPv6 L3 VPNs over SRv6 networks. This implementation is not particularly suitable in contexts where we need to deploy IPv6 L3 VPNs among different tenants which share the same network address schemes. The underlying problem lies in the fact that the current version of DT6 (called legacy DT6 from now on) needs a complex configuration to be applied on routers which requires ad-hoc routes and routing policy rules to ensure the correct isolation of tenants. Consequently, a new implementation of DT6 has been introduced with the aim of simplifying the construction of IPv6 L3 VPN services in the multi-tenant environment using SRv6 networks. To accomplish this task, we reused the same VRF infrastructure and SRv6 core components already exploited for implementing the SRv6 End.DT4 behavior. Currently the two End.DT6 implementations coexist seamlessly and can be used depending on the context and the user preferences. So, in order to support both versions of DT6 a new attribute (vrftable) has been introduced which allows us to differentiate the implementation of the behavior to be used. A SRv6 End.DT6 legacy behavior is still instantiated using a command like the following one: $ ip -6 route add 2001:db8::1 encap seg6local action End.DT6 table 100 dev eth0 While to instantiate the SRv6 End.DT6 in VRF mode, the command is still pretty straight forward: $ ip -6 route add 2001:db8::1 encap seg6local action End.DT6 vrftable 100 dev eth0. Obviously as in the case of SRv6 End.DT4, the VRF strict_mode parameter must be set (net.vrf.strict_mode=1) and the VRF associated with table 100 must exist. Please note that the instances of SRv6 End.DT6 legacy and End.DT6 VRF mode can coexist in the same system/configuration without problems. [1] https://tools.ietf.org/html/draft-ietf-spring-srv6-network-programming Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:15 +03:00
#ifdef CONFIG_NET_L3_MASTER_DEV
if (seg6_end_dt6_get_mode(slwt) == DT_LEGACY_MODE)
goto legacy_mode;
/* DT6_VRF_MODE */
seg6: add support for SRv6 End.DT46 Behavior IETF RFC 8986 [1] includes the definition of SRv6 End.DT4, End.DT6, and End.DT46 Behaviors. The current SRv6 code in the Linux kernel only implements End.DT4 and End.DT6 which can be used respectively to support IPv4-in-IPv6 and IPv6-in-IPv6 VPNs. With End.DT4 and End.DT6 it is not possible to create a single SRv6 VPN tunnel to carry both IPv4 and IPv6 traffic. The proposed End.DT46 implementation is meant to support the decapsulation of IPv4 and IPv6 traffic coming from a single SRv6 tunnel. The implementation of the SRv6 End.DT46 Behavior in the Linux kernel greatly simplifies the setup and operations of SRv6 VPNs. The SRv6 End.DT46 Behavior leverages the infrastructure of SRv6 End.DT{4,6} Behaviors implemented so far, because it makes use of a VRF device in order to force the routing lookup into the associated routing table. To make the End.DT46 work properly, it must be guaranteed that the routing table used for routing lookup operations is bound to one and only one VRF during the tunnel creation. Such constraint has to be enforced by enabling the VRF strict_mode sysctl parameter, i.e.: $ sysctl -wq net.vrf.strict_mode=1 Note that the same approach is used for the SRv6 End.DT4 Behavior and for the End.DT6 Behavior in VRF mode. The command used to instantiate an SRv6 End.DT46 Behavior is straightforward, i.e.: $ ip -6 route add 2001:db8::1 encap seg6local action End.DT46 vrftable 100 dev vrf100. [1] https://www.rfc-editor.org/rfc/rfc8986.html#name-enddt46-decapsulation-and-s ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Performance and impact of SRv6 End.DT46 Behavior on the SRv6 Networking ======================================================================= This patch aims to add the SRv6 End.DT46 Behavior with minimal impact on the performance of SRv6 End.DT4 and End.DT6 Behaviors. In order to verify this, we tested the performance of the newly introduced SRv6 End.DT46 Behavior and compared it with the performance of SRv6 End.DT{4,6} Behaviors, considering both the patched kernel and the kernel before applying the End.DT46 patch (referred to as vanilla kernel). In details, the following decapsulation scenarios were considered: 1.a) IPv6 traffic in SRv6 End.DT46 Behavior on patched kernel; 1.b) IPv4 traffic in SRv6 End.DT46 Behavior on patched kernel; 2.a) SRv6 End.DT6 Behavior (VRF mode) on patched kernel; 2.b) SRv6 End.DT4 Behavior on patched kernel; 3.a) SRv6 End.DT6 Behavior (VRF mode) on vanilla kernel (without the End.DT46 patch); 3.b) SRv6 End.DT4 Behavior on vanilla kernel (without the End.DT46 patch). All tests were performed on a testbed deployed on the CloudLab [2] facilities. We considered IPv{4,6} traffic handled by a single core (at 2.4 GHz on a Xeon(R) CPU E5-2630 v3) on kernel 5.13-rc1 using packets of size ~ 100 bytes. Scenario (1.a): average 684.70 kpps; std. dev. 0.7 kpps; Scenario (1.b): average 711.69 kpps; std. dev. 1.2 kpps; Scenario (2.a): average 690.70 kpps; std. dev. 1.2 kpps; Scenario (2.b): average 722.22 kpps; std. dev. 1.7 kpps; Scenario (3.a): average 690.02 kpps; std. dev. 2.6 kpps; Scenario (3.b): average 721.91 kpps; std. dev. 1.2 kpps; Considering the results for the patched kernel (1.a, 1.b, 2.a, 2.b) we observe that the performance degradation incurred in using End.DT46 rather than End.DT6 and End.DT4 respectively for IPv6 and IPv4 traffic is minimal, around 0.9% and 1.5%. Such very minimal performance degradation is the price to be paid if one prefers to use a single tunnel capable of handling both types of traffic (IPv4 and IPv6). Comparing the results for End.DT4 and End.DT6 under the patched and the vanilla kernel (2.a, 2.b, 3.a, 3.b) we observe that the introduction of the End.DT46 patch has no impact on the performance of End.DT4 and End.DT6. [2] https://www.cloudlab.us Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-17 20:16:44 +03:00
skb = end_dt_vrf_core(skb, slwt, AF_INET6);
seg6: add VRF support for SRv6 End.DT6 behavior SRv6 End.DT6 is defined in the SRv6 Network Programming [1]. The Linux kernel already offers an implementation of the SRv6 End.DT6 behavior which permits IPv6 L3 VPNs over SRv6 networks. This implementation is not particularly suitable in contexts where we need to deploy IPv6 L3 VPNs among different tenants which share the same network address schemes. The underlying problem lies in the fact that the current version of DT6 (called legacy DT6 from now on) needs a complex configuration to be applied on routers which requires ad-hoc routes and routing policy rules to ensure the correct isolation of tenants. Consequently, a new implementation of DT6 has been introduced with the aim of simplifying the construction of IPv6 L3 VPN services in the multi-tenant environment using SRv6 networks. To accomplish this task, we reused the same VRF infrastructure and SRv6 core components already exploited for implementing the SRv6 End.DT4 behavior. Currently the two End.DT6 implementations coexist seamlessly and can be used depending on the context and the user preferences. So, in order to support both versions of DT6 a new attribute (vrftable) has been introduced which allows us to differentiate the implementation of the behavior to be used. A SRv6 End.DT6 legacy behavior is still instantiated using a command like the following one: $ ip -6 route add 2001:db8::1 encap seg6local action End.DT6 table 100 dev eth0 While to instantiate the SRv6 End.DT6 in VRF mode, the command is still pretty straight forward: $ ip -6 route add 2001:db8::1 encap seg6local action End.DT6 vrftable 100 dev eth0. Obviously as in the case of SRv6 End.DT4, the VRF strict_mode parameter must be set (net.vrf.strict_mode=1) and the VRF associated with table 100 must exist. Please note that the instances of SRv6 End.DT6 legacy and End.DT6 VRF mode can coexist in the same system/configuration without problems. [1] https://tools.ietf.org/html/draft-ietf-spring-srv6-network-programming Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:15 +03:00
if (!skb)
/* packet has been processed and consumed by the VRF */
return 0;
if (IS_ERR(skb))
return PTR_ERR(skb);
/* note: this time we do not need to specify the table because the VRF
* takes care of selecting the correct table.
*/
seg6_lookup_any_nexthop(skb, NULL, 0, true);
return dst_input(skb);
legacy_mode:
#endif
seg6: fix skb transport_header after decap_and_validate() in the receive path (more precisely in ip6_rcv_core()) the skb->transport_header is set to skb->network_header + sizeof(*hdr). As a consequence, after routing operations, destination input expects to find skb->transport_header correctly set to the next protocol (or extension header) that follows the network protocol. However, decap behaviors (DX*, DT*) remove the outer IPv6 and SRH extension and do not set again the skb->transport_header pointer correctly. For this reason, the patch sets the skb->transport_header to the skb->network_header + sizeof(hdr) in each DX* and DT* behavior. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-16 18:05:53 +03:00
skb_set_transport_header(skb, sizeof(struct ipv6hdr));
seg6: allow local packet processing for SRv6 End.DT6 behavior End.DT6 behavior makes use of seg6_lookup_nexthop() function which drops all packets that are destined to be locally processed. However, DT* should be able to deliver decapsulated packets that are destined to local addresses. Function seg6_lookup_nexthop() is also used by DX6, so in order to maintain compatibility I created another routing helper function which is called seg6_lookup_any_nexthop(). This function is able to take into account both packets that have to be processed locally and the ones that are destined to be forwarded directly to another machine. Hence, seg6_lookup_any_nexthop() is used in DT6 rather than seg6_lookup_nexthop() to allow local delivery. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-22 19:22:42 +03:00
seg6_lookup_any_nexthop(skb, NULL, slwt->table, true);
ipv6: sr: implement additional seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END_T: regular SRH processing and forward to the next-hop looked up in the specified routing table. - SEG6_LOCAL_ACTION_END_DX2: decapsulate an L2 frame and forward it to the specified network interface. - SEG6_LOCAL_ACTION_END_DX4: decapsulate an IPv4 packet and forward it, possibly to the specified next-hop. - SEG6_LOCAL_ACTION_END_DT6: decapsulate an IPv6 packet and forward it to the next-hop looked up in the specified routing table. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 10:58:17 +03:00
return dst_input(skb);
drop:
kfree_skb(skb);
return -EINVAL;
}
seg6: add support for SRv6 End.DT46 Behavior IETF RFC 8986 [1] includes the definition of SRv6 End.DT4, End.DT6, and End.DT46 Behaviors. The current SRv6 code in the Linux kernel only implements End.DT4 and End.DT6 which can be used respectively to support IPv4-in-IPv6 and IPv6-in-IPv6 VPNs. With End.DT4 and End.DT6 it is not possible to create a single SRv6 VPN tunnel to carry both IPv4 and IPv6 traffic. The proposed End.DT46 implementation is meant to support the decapsulation of IPv4 and IPv6 traffic coming from a single SRv6 tunnel. The implementation of the SRv6 End.DT46 Behavior in the Linux kernel greatly simplifies the setup and operations of SRv6 VPNs. The SRv6 End.DT46 Behavior leverages the infrastructure of SRv6 End.DT{4,6} Behaviors implemented so far, because it makes use of a VRF device in order to force the routing lookup into the associated routing table. To make the End.DT46 work properly, it must be guaranteed that the routing table used for routing lookup operations is bound to one and only one VRF during the tunnel creation. Such constraint has to be enforced by enabling the VRF strict_mode sysctl parameter, i.e.: $ sysctl -wq net.vrf.strict_mode=1 Note that the same approach is used for the SRv6 End.DT4 Behavior and for the End.DT6 Behavior in VRF mode. The command used to instantiate an SRv6 End.DT46 Behavior is straightforward, i.e.: $ ip -6 route add 2001:db8::1 encap seg6local action End.DT46 vrftable 100 dev vrf100. [1] https://www.rfc-editor.org/rfc/rfc8986.html#name-enddt46-decapsulation-and-s ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Performance and impact of SRv6 End.DT46 Behavior on the SRv6 Networking ======================================================================= This patch aims to add the SRv6 End.DT46 Behavior with minimal impact on the performance of SRv6 End.DT4 and End.DT6 Behaviors. In order to verify this, we tested the performance of the newly introduced SRv6 End.DT46 Behavior and compared it with the performance of SRv6 End.DT{4,6} Behaviors, considering both the patched kernel and the kernel before applying the End.DT46 patch (referred to as vanilla kernel). In details, the following decapsulation scenarios were considered: 1.a) IPv6 traffic in SRv6 End.DT46 Behavior on patched kernel; 1.b) IPv4 traffic in SRv6 End.DT46 Behavior on patched kernel; 2.a) SRv6 End.DT6 Behavior (VRF mode) on patched kernel; 2.b) SRv6 End.DT4 Behavior on patched kernel; 3.a) SRv6 End.DT6 Behavior (VRF mode) on vanilla kernel (without the End.DT46 patch); 3.b) SRv6 End.DT4 Behavior on vanilla kernel (without the End.DT46 patch). All tests were performed on a testbed deployed on the CloudLab [2] facilities. We considered IPv{4,6} traffic handled by a single core (at 2.4 GHz on a Xeon(R) CPU E5-2630 v3) on kernel 5.13-rc1 using packets of size ~ 100 bytes. Scenario (1.a): average 684.70 kpps; std. dev. 0.7 kpps; Scenario (1.b): average 711.69 kpps; std. dev. 1.2 kpps; Scenario (2.a): average 690.70 kpps; std. dev. 1.2 kpps; Scenario (2.b): average 722.22 kpps; std. dev. 1.7 kpps; Scenario (3.a): average 690.02 kpps; std. dev. 2.6 kpps; Scenario (3.b): average 721.91 kpps; std. dev. 1.2 kpps; Considering the results for the patched kernel (1.a, 1.b, 2.a, 2.b) we observe that the performance degradation incurred in using End.DT46 rather than End.DT6 and End.DT4 respectively for IPv6 and IPv4 traffic is minimal, around 0.9% and 1.5%. Such very minimal performance degradation is the price to be paid if one prefers to use a single tunnel capable of handling both types of traffic (IPv4 and IPv6). Comparing the results for End.DT4 and End.DT6 under the patched and the vanilla kernel (2.a, 2.b, 3.a, 3.b) we observe that the introduction of the End.DT46 patch has no impact on the performance of End.DT4 and End.DT6. [2] https://www.cloudlab.us Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-17 20:16:44 +03:00
#ifdef CONFIG_NET_L3_MASTER_DEV
static int seg6_end_dt46_build(struct seg6_local_lwt *slwt, const void *cfg,
struct netlink_ext_ack *extack)
{
return __seg6_end_dt_vrf_build(slwt, cfg, AF_UNSPEC, extack);
}
static int input_action_end_dt46(struct sk_buff *skb,
struct seg6_local_lwt *slwt)
{
unsigned int off = 0;
int nexthdr;
nexthdr = ipv6_find_hdr(skb, &off, -1, NULL, NULL);
if (unlikely(nexthdr < 0))
goto drop;
switch (nexthdr) {
case IPPROTO_IPIP:
return input_action_end_dt4(skb, slwt);
case IPPROTO_IPV6:
return input_action_end_dt6(skb, slwt);
}
drop:
kfree_skb(skb);
return -EINVAL;
}
#endif
ipv6: sr: implement several seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END: regular SRH processing. The DA of the packet is updated to the next segment and forwarded accordingly. - SEG6_LOCAL_ACTION_END_X: same as above, except that the packet is forwarded to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_DX6: decapsulate the packet and forward to inner IPv6 packet to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_B6: insert the specified SRH directly after the IPv6 header of the packet. - SEG6_LOCAL_ACTION_END_B6_ENCAP: encapsulate the packet within an outer IPv6 header, containing the specified SRH. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:39:48 +03:00
/* push an SRH on top of the current one */
static int input_action_end_b6(struct sk_buff *skb, struct seg6_local_lwt *slwt)
{
struct ipv6_sr_hdr *srh;
int err = -EINVAL;
srh = get_and_validate_srh(skb);
if (!srh)
goto drop;
err = seg6_do_srh_inline(skb, slwt->srh);
if (err)
goto drop;
skb_set_transport_header(skb, sizeof(struct ipv6hdr));
ipv6: sr: export function lookup_nexthop The function lookup_nexthop is essential to implement most of the seg6local actions. As we want to provide a BPF helper allowing to apply some of these actions on the packet being processed, the helper should be able to call this function, hence the need to make it public. Moreover, if one argument is incorrect or if the next hop can not be found, an error should be returned by the BPF helper so the BPF program can adapt its processing of the packet (return an error, properly force the drop, ...). This patch hence makes this function return dst->error to indicate a possible error. Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-20 16:58:13 +03:00
seg6_lookup_nexthop(skb, NULL, 0);
ipv6: sr: implement several seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END: regular SRH processing. The DA of the packet is updated to the next segment and forwarded accordingly. - SEG6_LOCAL_ACTION_END_X: same as above, except that the packet is forwarded to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_DX6: decapsulate the packet and forward to inner IPv6 packet to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_B6: insert the specified SRH directly after the IPv6 header of the packet. - SEG6_LOCAL_ACTION_END_B6_ENCAP: encapsulate the packet within an outer IPv6 header, containing the specified SRH. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:39:48 +03:00
return dst_input(skb);
drop:
kfree_skb(skb);
return err;
}
/* encapsulate within an outer IPv6 header and a specified SRH */
static int input_action_end_b6_encap(struct sk_buff *skb,
struct seg6_local_lwt *slwt)
{
struct ipv6_sr_hdr *srh;
int err = -EINVAL;
srh = get_and_validate_srh(skb);
if (!srh)
goto drop;
ipv6: sr: add helper functions for seg6local This patch adds three helper functions to be used with the seg6local packet processing actions. The decap_and_validate() function will be used by the End.D* actions, that decapsulate an SR-enabled packet. The advance_nextseg() function applies the fundamental operations to update an SRH for the next segment. The lookup_nexthop() function helps select the next-hop for the processed SR packets. It supports an optional next-hop address to route the packet specifically through it, and an optional routing table to use. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 10:56:47 +03:00
advance_nextseg(srh, &ipv6_hdr(skb)->daddr);
ipv6: sr: implement several seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END: regular SRH processing. The DA of the packet is updated to the next segment and forwarded accordingly. - SEG6_LOCAL_ACTION_END_X: same as above, except that the packet is forwarded to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_DX6: decapsulate the packet and forward to inner IPv6 packet to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_B6: insert the specified SRH directly after the IPv6 header of the packet. - SEG6_LOCAL_ACTION_END_B6_ENCAP: encapsulate the packet within an outer IPv6 header, containing the specified SRH. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:39:48 +03:00
skb_reset_inner_headers(skb);
skb->encapsulation = 1;
ipv6: sr: add support for ip4ip6 encapsulation This patch enables the SRv6 encapsulation mode to carry an IPv4 payload. All the infrastructure was already present, I just had to add a parameter to seg6_do_srh_encap() to specify the inner packet protocol, and perform some additional checks. Usage example: ip route add 1.2.3.4 encap seg6 mode encap segs fc00::1,fc00::2 dev eth0 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 10:56:44 +03:00
err = seg6_do_srh_encap(skb, slwt->srh, IPPROTO_IPV6);
ipv6: sr: implement several seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END: regular SRH processing. The DA of the packet is updated to the next segment and forwarded accordingly. - SEG6_LOCAL_ACTION_END_X: same as above, except that the packet is forwarded to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_DX6: decapsulate the packet and forward to inner IPv6 packet to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_B6: insert the specified SRH directly after the IPv6 header of the packet. - SEG6_LOCAL_ACTION_END_B6_ENCAP: encapsulate the packet within an outer IPv6 header, containing the specified SRH. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:39:48 +03:00
if (err)
goto drop;
skb_set_transport_header(skb, sizeof(struct ipv6hdr));
ipv6: sr: export function lookup_nexthop The function lookup_nexthop is essential to implement most of the seg6local actions. As we want to provide a BPF helper allowing to apply some of these actions on the packet being processed, the helper should be able to call this function, hence the need to make it public. Moreover, if one argument is incorrect or if the next hop can not be found, an error should be returned by the BPF helper so the BPF program can adapt its processing of the packet (return an error, properly force the drop, ...). This patch hence makes this function return dst->error to indicate a possible error. Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-20 16:58:13 +03:00
seg6_lookup_nexthop(skb, NULL, 0);
ipv6: sr: implement several seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END: regular SRH processing. The DA of the packet is updated to the next segment and forwarded accordingly. - SEG6_LOCAL_ACTION_END_X: same as above, except that the packet is forwarded to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_DX6: decapsulate the packet and forward to inner IPv6 packet to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_B6: insert the specified SRH directly after the IPv6 header of the packet. - SEG6_LOCAL_ACTION_END_B6_ENCAP: encapsulate the packet within an outer IPv6 header, containing the specified SRH. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:39:48 +03:00
return dst_input(skb);
drop:
kfree_skb(skb);
return err;
}
bpf: Add IPv6 Segment Routing helpers The BPF seg6local hook should be powerful enough to enable users to implement most of the use-cases one could think of. After some thinking, we figured out that the following actions should be possible on a SRv6 packet, requiring 3 specific helpers : - bpf_lwt_seg6_store_bytes: Modify non-sensitive fields of the SRH - bpf_lwt_seg6_adjust_srh: Allow to grow or shrink a SRH (to add/delete TLVs) - bpf_lwt_seg6_action: Apply some SRv6 network programming actions (specifically End.X, End.T, End.B6 and End.B6.Encap) The specifications of these helpers are provided in the patch (see include/uapi/linux/bpf.h). The non-sensitive fields of the SRH are the following : flags, tag and TLVs. The other fields can not be modified, to maintain the SRH integrity. Flags, tag and TLVs can easily be modified as their validity can be checked afterwards via seg6_validate_srh. It is not allowed to modify the segments directly. If one wants to add segments on the path, he should stack a new SRH using the End.B6 action via bpf_lwt_seg6_action. Growing, shrinking or editing TLVs via the helpers will flag the SRH as invalid, and it will have to be re-validated before re-entering the IPv6 layer. This flag is stored in a per-CPU buffer, along with the current header length in bytes. Storing the SRH len in bytes in the control block is mandatory when using bpf_lwt_seg6_adjust_srh. The Header Ext. Length field contains the SRH len rounded to 8 bytes (a padding TLV can be inserted to ensure the 8-bytes boundary). When adding/deleting TLVs within the BPF program, the SRH may temporary be in an invalid state where its length cannot be rounded to 8 bytes without remainder, hence the need to store the length in bytes separately. The caller of the BPF program can then ensure that the SRH's final length is valid using this value. Again, a final SRH modified by a BPF program which doesn’t respect the 8-bytes boundary will be discarded as it will be considered as invalid. Finally, a fourth helper is provided, bpf_lwt_push_encap, which is available from the LWT BPF IN hook, but not from the seg6local BPF one. This helper allows to encapsulate a Segment Routing Header (either with a new outer IPv6 header, or by inlining it directly in the existing IPv6 header) into a non-SRv6 packet. This helper is required if we want to offer the possibility to dynamically encapsulate a SRH for non-SRv6 packet, as the BPF seg6local hook only works on traffic already containing a SRH. This is the BPF equivalent of the seg6 LWT infrastructure, which achieves the same purpose but with a static SRH per route. These helpers require CONFIG_IPV6=y (and not =m). Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-20 16:58:14 +03:00
DEFINE_PER_CPU(struct seg6_bpf_srh_state, seg6_bpf_srh_states);
bpf: add End.DT6 action to bpf_lwt_seg6_action helper The seg6local LWT provides the End.DT6 action, which allows to decapsulate an outer IPv6 header containing a Segment Routing Header (SRH), full specification is available here: https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-05 This patch adds this action now to the seg6local BPF interface. Since it is not mandatory that the inner IPv6 header also contains a SRH, seg6_bpf_srh_state has been extended with a pointer to a possible SRH of the outermost IPv6 header. This helps assessing if the validation must be triggered or not, and avoids some calls to ipv6_find_hdr. v3: s/1/true, s/0/false for boolean values v2: - changed true/false -> 1/0 - preempt_enable no longer called in first conditional block Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-26 05:10:40 +03:00
bool seg6_bpf_has_valid_srh(struct sk_buff *skb)
{
struct seg6_bpf_srh_state *srh_state =
this_cpu_ptr(&seg6_bpf_srh_states);
struct ipv6_sr_hdr *srh = srh_state->srh;
if (unlikely(srh == NULL))
return false;
if (unlikely(!srh_state->valid)) {
if ((srh_state->hdrlen & 7) != 0)
return false;
srh->hdrlen = (u8)(srh_state->hdrlen >> 3);
seg6: fix seg6_validate_srh() to avoid slab-out-of-bounds The seg6_validate_srh() is used to validate SRH for three cases: case1: SRH of data-plane SRv6 packets to be processed by the Linux kernel. Case2: SRH of the netlink message received from user-space (iproute2) Case3: SRH injected into packets through setsockopt In case1, the SRH can be encoded in the Reduced way (i.e., first SID is carried in DA only and not represented as SID in the SRH) and the seg6_validate_srh() now handles this case correctly. In case2 and case3, the SRH shouldn’t be encoded in the Reduced way otherwise we lose the first segment (i.e., the first hop). The current implementation of the seg6_validate_srh() allow SRH of case2 and case3 to be encoded in the Reduced way. This leads a slab-out-of-bounds problem. This patch verifies SRH of case1, case2 and case3. Allowing case1 to be reduced while preventing SRH of case2 and case3 from being reduced . Reported-by: syzbot+e8c028b62439eac42073@syzkaller.appspotmail.com Reported-by: YueHaibing <yuehaibing@huawei.com> Fixes: 0cb7498f234e ("seg6: fix SRH processing to comply with RFC8754") Signed-off-by: Ahmed Abdelsalam <ahabdels@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-03 09:54:42 +03:00
if (!seg6_validate_srh(srh, (srh->hdrlen + 1) << 3, true))
bpf: add End.DT6 action to bpf_lwt_seg6_action helper The seg6local LWT provides the End.DT6 action, which allows to decapsulate an outer IPv6 header containing a Segment Routing Header (SRH), full specification is available here: https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-05 This patch adds this action now to the seg6local BPF interface. Since it is not mandatory that the inner IPv6 header also contains a SRH, seg6_bpf_srh_state has been extended with a pointer to a possible SRH of the outermost IPv6 header. This helps assessing if the validation must be triggered or not, and avoids some calls to ipv6_find_hdr. v3: s/1/true, s/0/false for boolean values v2: - changed true/false -> 1/0 - preempt_enable no longer called in first conditional block Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-26 05:10:40 +03:00
return false;
srh_state->valid = true;
}
return true;
}
ipv6: sr: Add seg6local action End.BPF This patch adds the End.BPF action to the LWT seg6local infrastructure. This action works like any other seg6local End action, meaning that an IPv6 header with SRH is needed, whose DA has to be equal to the SID of the action. It will also advance the SRH to the next segment, the BPF program does not have to take care of this. Since the BPF program may not be a source of instability in the kernel, it is important to ensure that the integrity of the packet is maintained before yielding it back to the IPv6 layer. The hook hence keeps track if the SRH has been altered through the helpers, and re-validates its content if needed with seg6_validate_srh. The state kept for validation is stored in a per-CPU buffer. The BPF program is not allowed to directly write into the packet, and only some fields of the SRH can be altered through the helper bpf_lwt_seg6_store_bytes. Performances profiling has shown that the SRH re-validation does not induce a significant overhead. If the altered SRH is deemed as invalid, the packet is dropped. This validation is also done before executing any action through bpf_lwt_seg6_action, and will not be performed again if the SRH is not modified after calling the action. The BPF program may return 3 types of return codes: - BPF_OK: the End.BPF action will look up the next destination through seg6_lookup_nexthop. - BPF_REDIRECT: if an action has been executed through the bpf_lwt_seg6_action helper, the BPF program should return this value, as the skb's destination is already set and the default lookup should not be performed. - BPF_DROP : the packet will be dropped. Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-20 16:58:16 +03:00
static int input_action_end_bpf(struct sk_buff *skb,
struct seg6_local_lwt *slwt)
{
struct seg6_bpf_srh_state *srh_state =
this_cpu_ptr(&seg6_bpf_srh_states);
struct ipv6_sr_hdr *srh;
int ret;
srh = get_and_validate_srh(skb);
bpf: add End.DT6 action to bpf_lwt_seg6_action helper The seg6local LWT provides the End.DT6 action, which allows to decapsulate an outer IPv6 header containing a Segment Routing Header (SRH), full specification is available here: https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-05 This patch adds this action now to the seg6local BPF interface. Since it is not mandatory that the inner IPv6 header also contains a SRH, seg6_bpf_srh_state has been extended with a pointer to a possible SRH of the outermost IPv6 header. This helps assessing if the validation must be triggered or not, and avoids some calls to ipv6_find_hdr. v3: s/1/true, s/0/false for boolean values v2: - changed true/false -> 1/0 - preempt_enable no longer called in first conditional block Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-26 05:10:40 +03:00
if (!srh) {
kfree_skb(skb);
return -EINVAL;
}
ipv6: sr: Add seg6local action End.BPF This patch adds the End.BPF action to the LWT seg6local infrastructure. This action works like any other seg6local End action, meaning that an IPv6 header with SRH is needed, whose DA has to be equal to the SID of the action. It will also advance the SRH to the next segment, the BPF program does not have to take care of this. Since the BPF program may not be a source of instability in the kernel, it is important to ensure that the integrity of the packet is maintained before yielding it back to the IPv6 layer. The hook hence keeps track if the SRH has been altered through the helpers, and re-validates its content if needed with seg6_validate_srh. The state kept for validation is stored in a per-CPU buffer. The BPF program is not allowed to directly write into the packet, and only some fields of the SRH can be altered through the helper bpf_lwt_seg6_store_bytes. Performances profiling has shown that the SRH re-validation does not induce a significant overhead. If the altered SRH is deemed as invalid, the packet is dropped. This validation is also done before executing any action through bpf_lwt_seg6_action, and will not be performed again if the SRH is not modified after calling the action. The BPF program may return 3 types of return codes: - BPF_OK: the End.BPF action will look up the next destination through seg6_lookup_nexthop. - BPF_REDIRECT: if an action has been executed through the bpf_lwt_seg6_action helper, the BPF program should return this value, as the skb's destination is already set and the default lookup should not be performed. - BPF_DROP : the packet will be dropped. Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-20 16:58:16 +03:00
advance_nextseg(srh, &ipv6_hdr(skb)->daddr);
/* preempt_disable is needed to protect the per-CPU buffer srh_state,
* which is also accessed by the bpf_lwt_seg6_* helpers
*/
preempt_disable();
bpf: add End.DT6 action to bpf_lwt_seg6_action helper The seg6local LWT provides the End.DT6 action, which allows to decapsulate an outer IPv6 header containing a Segment Routing Header (SRH), full specification is available here: https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-05 This patch adds this action now to the seg6local BPF interface. Since it is not mandatory that the inner IPv6 header also contains a SRH, seg6_bpf_srh_state has been extended with a pointer to a possible SRH of the outermost IPv6 header. This helps assessing if the validation must be triggered or not, and avoids some calls to ipv6_find_hdr. v3: s/1/true, s/0/false for boolean values v2: - changed true/false -> 1/0 - preempt_enable no longer called in first conditional block Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-26 05:10:40 +03:00
srh_state->srh = srh;
ipv6: sr: Add seg6local action End.BPF This patch adds the End.BPF action to the LWT seg6local infrastructure. This action works like any other seg6local End action, meaning that an IPv6 header with SRH is needed, whose DA has to be equal to the SID of the action. It will also advance the SRH to the next segment, the BPF program does not have to take care of this. Since the BPF program may not be a source of instability in the kernel, it is important to ensure that the integrity of the packet is maintained before yielding it back to the IPv6 layer. The hook hence keeps track if the SRH has been altered through the helpers, and re-validates its content if needed with seg6_validate_srh. The state kept for validation is stored in a per-CPU buffer. The BPF program is not allowed to directly write into the packet, and only some fields of the SRH can be altered through the helper bpf_lwt_seg6_store_bytes. Performances profiling has shown that the SRH re-validation does not induce a significant overhead. If the altered SRH is deemed as invalid, the packet is dropped. This validation is also done before executing any action through bpf_lwt_seg6_action, and will not be performed again if the SRH is not modified after calling the action. The BPF program may return 3 types of return codes: - BPF_OK: the End.BPF action will look up the next destination through seg6_lookup_nexthop. - BPF_REDIRECT: if an action has been executed through the bpf_lwt_seg6_action helper, the BPF program should return this value, as the skb's destination is already set and the default lookup should not be performed. - BPF_DROP : the packet will be dropped. Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-20 16:58:16 +03:00
srh_state->hdrlen = srh->hdrlen << 3;
bpf: add End.DT6 action to bpf_lwt_seg6_action helper The seg6local LWT provides the End.DT6 action, which allows to decapsulate an outer IPv6 header containing a Segment Routing Header (SRH), full specification is available here: https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-05 This patch adds this action now to the seg6local BPF interface. Since it is not mandatory that the inner IPv6 header also contains a SRH, seg6_bpf_srh_state has been extended with a pointer to a possible SRH of the outermost IPv6 header. This helps assessing if the validation must be triggered or not, and avoids some calls to ipv6_find_hdr. v3: s/1/true, s/0/false for boolean values v2: - changed true/false -> 1/0 - preempt_enable no longer called in first conditional block Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-26 05:10:40 +03:00
srh_state->valid = true;
ipv6: sr: Add seg6local action End.BPF This patch adds the End.BPF action to the LWT seg6local infrastructure. This action works like any other seg6local End action, meaning that an IPv6 header with SRH is needed, whose DA has to be equal to the SID of the action. It will also advance the SRH to the next segment, the BPF program does not have to take care of this. Since the BPF program may not be a source of instability in the kernel, it is important to ensure that the integrity of the packet is maintained before yielding it back to the IPv6 layer. The hook hence keeps track if the SRH has been altered through the helpers, and re-validates its content if needed with seg6_validate_srh. The state kept for validation is stored in a per-CPU buffer. The BPF program is not allowed to directly write into the packet, and only some fields of the SRH can be altered through the helper bpf_lwt_seg6_store_bytes. Performances profiling has shown that the SRH re-validation does not induce a significant overhead. If the altered SRH is deemed as invalid, the packet is dropped. This validation is also done before executing any action through bpf_lwt_seg6_action, and will not be performed again if the SRH is not modified after calling the action. The BPF program may return 3 types of return codes: - BPF_OK: the End.BPF action will look up the next destination through seg6_lookup_nexthop. - BPF_REDIRECT: if an action has been executed through the bpf_lwt_seg6_action helper, the BPF program should return this value, as the skb's destination is already set and the default lookup should not be performed. - BPF_DROP : the packet will be dropped. Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-20 16:58:16 +03:00
rcu_read_lock();
bpf_compute_data_pointers(skb);
ret = bpf_prog_run_save_cb(slwt->bpf.prog, skb);
rcu_read_unlock();
switch (ret) {
case BPF_OK:
case BPF_REDIRECT:
break;
case BPF_DROP:
goto drop;
default:
pr_warn_once("bpf-seg6local: Illegal return value %u\n", ret);
goto drop;
}
bpf: add End.DT6 action to bpf_lwt_seg6_action helper The seg6local LWT provides the End.DT6 action, which allows to decapsulate an outer IPv6 header containing a Segment Routing Header (SRH), full specification is available here: https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-05 This patch adds this action now to the seg6local BPF interface. Since it is not mandatory that the inner IPv6 header also contains a SRH, seg6_bpf_srh_state has been extended with a pointer to a possible SRH of the outermost IPv6 header. This helps assessing if the validation must be triggered or not, and avoids some calls to ipv6_find_hdr. v3: s/1/true, s/0/false for boolean values v2: - changed true/false -> 1/0 - preempt_enable no longer called in first conditional block Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-26 05:10:40 +03:00
if (srh_state->srh && !seg6_bpf_has_valid_srh(skb))
ipv6: sr: Add seg6local action End.BPF This patch adds the End.BPF action to the LWT seg6local infrastructure. This action works like any other seg6local End action, meaning that an IPv6 header with SRH is needed, whose DA has to be equal to the SID of the action. It will also advance the SRH to the next segment, the BPF program does not have to take care of this. Since the BPF program may not be a source of instability in the kernel, it is important to ensure that the integrity of the packet is maintained before yielding it back to the IPv6 layer. The hook hence keeps track if the SRH has been altered through the helpers, and re-validates its content if needed with seg6_validate_srh. The state kept for validation is stored in a per-CPU buffer. The BPF program is not allowed to directly write into the packet, and only some fields of the SRH can be altered through the helper bpf_lwt_seg6_store_bytes. Performances profiling has shown that the SRH re-validation does not induce a significant overhead. If the altered SRH is deemed as invalid, the packet is dropped. This validation is also done before executing any action through bpf_lwt_seg6_action, and will not be performed again if the SRH is not modified after calling the action. The BPF program may return 3 types of return codes: - BPF_OK: the End.BPF action will look up the next destination through seg6_lookup_nexthop. - BPF_REDIRECT: if an action has been executed through the bpf_lwt_seg6_action helper, the BPF program should return this value, as the skb's destination is already set and the default lookup should not be performed. - BPF_DROP : the packet will be dropped. Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-20 16:58:16 +03:00
goto drop;
bpf: add End.DT6 action to bpf_lwt_seg6_action helper The seg6local LWT provides the End.DT6 action, which allows to decapsulate an outer IPv6 header containing a Segment Routing Header (SRH), full specification is available here: https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-05 This patch adds this action now to the seg6local BPF interface. Since it is not mandatory that the inner IPv6 header also contains a SRH, seg6_bpf_srh_state has been extended with a pointer to a possible SRH of the outermost IPv6 header. This helps assessing if the validation must be triggered or not, and avoids some calls to ipv6_find_hdr. v3: s/1/true, s/0/false for boolean values v2: - changed true/false -> 1/0 - preempt_enable no longer called in first conditional block Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-26 05:10:40 +03:00
preempt_enable();
ipv6: sr: Add seg6local action End.BPF This patch adds the End.BPF action to the LWT seg6local infrastructure. This action works like any other seg6local End action, meaning that an IPv6 header with SRH is needed, whose DA has to be equal to the SID of the action. It will also advance the SRH to the next segment, the BPF program does not have to take care of this. Since the BPF program may not be a source of instability in the kernel, it is important to ensure that the integrity of the packet is maintained before yielding it back to the IPv6 layer. The hook hence keeps track if the SRH has been altered through the helpers, and re-validates its content if needed with seg6_validate_srh. The state kept for validation is stored in a per-CPU buffer. The BPF program is not allowed to directly write into the packet, and only some fields of the SRH can be altered through the helper bpf_lwt_seg6_store_bytes. Performances profiling has shown that the SRH re-validation does not induce a significant overhead. If the altered SRH is deemed as invalid, the packet is dropped. This validation is also done before executing any action through bpf_lwt_seg6_action, and will not be performed again if the SRH is not modified after calling the action. The BPF program may return 3 types of return codes: - BPF_OK: the End.BPF action will look up the next destination through seg6_lookup_nexthop. - BPF_REDIRECT: if an action has been executed through the bpf_lwt_seg6_action helper, the BPF program should return this value, as the skb's destination is already set and the default lookup should not be performed. - BPF_DROP : the packet will be dropped. Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-20 16:58:16 +03:00
if (ret != BPF_REDIRECT)
seg6_lookup_nexthop(skb, NULL, 0);
return dst_input(skb);
drop:
bpf: add End.DT6 action to bpf_lwt_seg6_action helper The seg6local LWT provides the End.DT6 action, which allows to decapsulate an outer IPv6 header containing a Segment Routing Header (SRH), full specification is available here: https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-05 This patch adds this action now to the seg6local BPF interface. Since it is not mandatory that the inner IPv6 header also contains a SRH, seg6_bpf_srh_state has been extended with a pointer to a possible SRH of the outermost IPv6 header. This helps assessing if the validation must be triggered or not, and avoids some calls to ipv6_find_hdr. v3: s/1/true, s/0/false for boolean values v2: - changed true/false -> 1/0 - preempt_enable no longer called in first conditional block Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-26 05:10:40 +03:00
preempt_enable();
ipv6: sr: Add seg6local action End.BPF This patch adds the End.BPF action to the LWT seg6local infrastructure. This action works like any other seg6local End action, meaning that an IPv6 header with SRH is needed, whose DA has to be equal to the SID of the action. It will also advance the SRH to the next segment, the BPF program does not have to take care of this. Since the BPF program may not be a source of instability in the kernel, it is important to ensure that the integrity of the packet is maintained before yielding it back to the IPv6 layer. The hook hence keeps track if the SRH has been altered through the helpers, and re-validates its content if needed with seg6_validate_srh. The state kept for validation is stored in a per-CPU buffer. The BPF program is not allowed to directly write into the packet, and only some fields of the SRH can be altered through the helper bpf_lwt_seg6_store_bytes. Performances profiling has shown that the SRH re-validation does not induce a significant overhead. If the altered SRH is deemed as invalid, the packet is dropped. This validation is also done before executing any action through bpf_lwt_seg6_action, and will not be performed again if the SRH is not modified after calling the action. The BPF program may return 3 types of return codes: - BPF_OK: the End.BPF action will look up the next destination through seg6_lookup_nexthop. - BPF_REDIRECT: if an action has been executed through the bpf_lwt_seg6_action helper, the BPF program should return this value, as the skb's destination is already set and the default lookup should not be performed. - BPF_DROP : the packet will be dropped. Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-20 16:58:16 +03:00
kfree_skb(skb);
return -EINVAL;
}
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:26 +03:00
static struct seg6_action_desc seg6_action_table[] = {
{
.action = SEG6_LOCAL_ACTION_END,
.attrs = 0,
seg6: add NEXT-C-SID support for SRv6 End behavior The NEXT-C-SID mechanism described in [1] offers the possibility of encoding several SRv6 segments within a single 128 bit SID address. Such a SID address is called a Compressed SID (C-SID) container. In this way, the length of the SID List can be drastically reduced. A SID instantiated with the NEXT-C-SID flavor considers an IPv6 address logically structured in three main blocks: i) Locator-Block; ii) Locator-Node Function; iii) Argument. C-SID container +------------------------------------------------------------------+ | Locator-Block |Loc-Node| Argument | | |Function| | +------------------------------------------------------------------+ <--------- B -----------> <- NF -> <------------- A ---------------> (i) The Locator-Block can be any IPv6 prefix available to the provider; (ii) The Locator-Node Function represents the node and the function to be triggered when a packet is received on the node; (iii) The Argument carries the remaining C-SIDs in the current C-SID container. The NEXT-C-SID mechanism relies on the "flavors" framework defined in [2]. The flavors represent additional operations that can modify or extend a subset of the existing behaviors. This patch introduces the support for flavors in SRv6 End behavior implementing the NEXT-C-SID one. An SRv6 End behavior with NEXT-C-SID flavor works as an End behavior but it is capable of processing the compressed SID List encoded in C-SID containers. An SRv6 End behavior with NEXT-C-SID flavor can be configured to support user-provided Locator-Block and Locator-Node Function lengths. In this implementation, such lengths must be evenly divisible by 8 (i.e. must be byte-aligned), otherwise the kernel informs the user about invalid values with a meaningful error code and message through netlink_ext_ack. If Locator-Block and/or Locator-Node Function lengths are not provided by the user during configuration of an SRv6 End behavior instance with NEXT-C-SID flavor, the kernel will choose their default values i.e., 32-bit Locator-Block and 16-bit Locator-Node Function. [1] - https://datatracker.ietf.org/doc/html/draft-ietf-spring-srv6-srh-compression [2] - https://datatracker.ietf.org/doc/html/rfc8986 Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-09-12 20:16:18 +03:00
.optattrs = SEG6_F_LOCAL_COUNTERS |
SEG6_F_ATTR(SEG6_LOCAL_FLAVORS),
ipv6: sr: implement several seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END: regular SRH processing. The DA of the packet is updated to the next segment and forwarded accordingly. - SEG6_LOCAL_ACTION_END_X: same as above, except that the packet is forwarded to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_DX6: decapsulate the packet and forward to inner IPv6 packet to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_B6: insert the specified SRH directly after the IPv6 header of the packet. - SEG6_LOCAL_ACTION_END_B6_ENCAP: encapsulate the packet within an outer IPv6 header, containing the specified SRH. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:39:48 +03:00
.input = input_action_end,
},
{
.action = SEG6_LOCAL_ACTION_END_X,
seg6: fool-proof the processing of SRv6 behavior attributes The set of required attributes for a given SRv6 behavior is identified using a bitmap stored in an unsigned long, since the initial design of SRv6 networking in Linux. Recently the same approach has been used for identifying the optional attributes. However, the number of attributes supported by SRv6 behaviors depends on the size of the unsigned long type which changes with the architecture. Indeed, on a 64-bit architecture, an SRv6 behavior can support up to 64 attributes while on a 32-bit architecture it can support at most 32 attributes. To fool-proof the processing of SRv6 behaviors we verify, at compile time, that the set of all supported SRv6 attributes can be encoded into a bitmap stored in an unsigned long. Otherwise, kernel build fails forcing developers to reconsider adding a new attribute or extend the total number of supported attributes by the SRv6 behaviors. Moreover, we replace all patterns (1 << i) with the macro SEG6_F_ATTR(i) in order to address potential overflow issues caused by 32-bit signed arithmetic. Thanks to Colin Ian King for catching the overflow problem, providing a solution and inspiring this patch. Thanks to Jakub Kicinski for his useful suggestions during the design of this patch. v2: - remove the SEG6_LOCAL_MAX_SUPP which is not strictly needed: it can be derived from the unsigned long type. Thanks to David Ahern for pointing it out. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/r/20210206170934.5982-1-andrea.mayer@uniroma2.it Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-02-06 20:09:34 +03:00
.attrs = SEG6_F_ATTR(SEG6_LOCAL_NH6),
seg6: add counters support for SRv6 Behaviors This patch provides counters for SRv6 Behaviors as defined in [1], section 6. For each SRv6 Behavior instance, counters defined in [1] are: - the total number of packets that have been correctly processed; - the total amount of traffic in bytes of all packets that have been correctly processed; In addition, this patch introduces a new counter that counts the number of packets that have NOT been properly processed (i.e. errors) by an SRv6 Behavior instance. Counters are not only interesting for network monitoring purposes (i.e. counting the number of packets processed by a given behavior) but they also provide a simple tool for checking whether a behavior instance is working as we expect or not. Counters can be useful for troubleshooting misconfigured SRv6 networks. Indeed, an SRv6 Behavior can silently drop packets for very different reasons (i.e. wrong SID configuration, interfaces set with SID addresses, etc) without any notification/message to the user. Due to the nature of SRv6 networks, diagnostic tools such as ping and traceroute may be ineffective: paths used for reaching a given router can be totally different from the ones followed by probe packets. In addition, paths are often asymmetrical and this makes it even more difficult to keep up with the journey of the packets and to understand which behaviors are actually processing our traffic. When counters are enabled on an SRv6 Behavior instance, it is possible to verify if packets are actually processed by such behavior and what is the outcome of the processing. Therefore, the counters for SRv6 Behaviors offer an non-invasive observability point which can be leveraged for both traffic monitoring and troubleshooting purposes. [1] https://www.rfc-editor.org/rfc/rfc8986.html#name-counters Troubleshooting using SRv6 Behavior counters -------------------------------------------- Let's make a brief example to see how helpful counters can be for SRv6 networks. Let's consider a node where an SRv6 End Behavior receives an SRv6 packet whose Segment Left (SL) is equal to 0. In this case, the End Behavior (which accepts only packets with SL >= 1) discards the packet and increases the error counter. This information can be leveraged by the network operator for troubleshooting. Indeed, the error counter is telling the user that the packet: (i) arrived at the node; (ii) the packet has been taken into account by the SRv6 End behavior; (iii) but an error has occurred during the processing. The error (iii) could be caused by different reasons, such as wrong route settings on the node or due to an invalid SID List carried by the SRv6 packet. Anyway, the error counter is used to exclude that the packet did not arrive at the node or it has not been processed by the behavior at all. Turning on/off counters for SRv6 Behaviors ------------------------------------------ Each SRv6 Behavior instance can be configured, at the time of its creation, to make use of counters. This is done through iproute2 which allows the user to create an SRv6 Behavior instance specifying the optional "count" attribute as shown in the following example: $ ip -6 route add 2001:db8::1 encap seg6local action End count dev eth0 per-behavior counters can be shown by adding "-s" to the iproute2 command line, i.e.: $ ip -s -6 route show 2001:db8::1 2001:db8::1 encap seg6local action End packets 0 bytes 0 errors 0 dev eth0 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Impact of counters for SRv6 Behaviors on performance ==================================================== To determine the performance impact due to the introduction of counters in the SRv6 Behavior subsystem, we have carried out extensive tests. We chose to test the throughput achieved by the SRv6 End.DX2 Behavior because, among all the other behaviors implemented so far, it reaches the highest throughput which is around 1.5 Mpps (per core at 2.4 GHz on a Xeon(R) CPU E5-2630 v3) on kernel 5.12-rc2 using packets of size ~ 100 bytes. Three different tests were conducted in order to evaluate the overall throughput of the SRv6 End.DX2 Behavior in the following scenarios: 1) vanilla kernel (without the SRv6 Behavior counters patch) and a single instance of an SRv6 End.DX2 Behavior; 2) patched kernel with SRv6 Behavior counters and a single instance of an SRv6 End.DX2 Behavior with counters turned off; 3) patched kernel with SRv6 Behavior counters and a single instance of SRv6 End.DX2 Behavior with counters turned on. All tests were performed on a testbed deployed on the CloudLab facilities [2], a flexible infrastructure dedicated to scientific research on the future of Cloud Computing. Results of tests are shown in the following table: Scenario (1): average 1504764,81 pps (~1504,76 kpps); std. dev 3956,82 pps Scenario (2): average 1501469,78 pps (~1501,47 kpps); std. dev 2979,85 pps Scenario (3): average 1501315,13 pps (~1501,32 kpps); std. dev 2956,00 pps As can be observed, throughputs achieved in scenarios (2),(3) did not suffer any observable degradation compared to scenario (1). Thanks to Jakub Kicinski and David Ahern for their valuable suggestions and comments provided during the discussion of the proposed RFCs. [2] https://www.cloudlab.us Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-04-27 18:44:04 +03:00
.optattrs = SEG6_F_LOCAL_COUNTERS,
ipv6: sr: implement several seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END: regular SRH processing. The DA of the packet is updated to the next segment and forwarded accordingly. - SEG6_LOCAL_ACTION_END_X: same as above, except that the packet is forwarded to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_DX6: decapsulate the packet and forward to inner IPv6 packet to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_B6: insert the specified SRH directly after the IPv6 header of the packet. - SEG6_LOCAL_ACTION_END_B6_ENCAP: encapsulate the packet within an outer IPv6 header, containing the specified SRH. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:39:48 +03:00
.input = input_action_end_x,
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:26 +03:00
},
ipv6: sr: implement additional seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END_T: regular SRH processing and forward to the next-hop looked up in the specified routing table. - SEG6_LOCAL_ACTION_END_DX2: decapsulate an L2 frame and forward it to the specified network interface. - SEG6_LOCAL_ACTION_END_DX4: decapsulate an IPv4 packet and forward it, possibly to the specified next-hop. - SEG6_LOCAL_ACTION_END_DT6: decapsulate an IPv6 packet and forward it to the next-hop looked up in the specified routing table. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 10:58:17 +03:00
{
.action = SEG6_LOCAL_ACTION_END_T,
seg6: fool-proof the processing of SRv6 behavior attributes The set of required attributes for a given SRv6 behavior is identified using a bitmap stored in an unsigned long, since the initial design of SRv6 networking in Linux. Recently the same approach has been used for identifying the optional attributes. However, the number of attributes supported by SRv6 behaviors depends on the size of the unsigned long type which changes with the architecture. Indeed, on a 64-bit architecture, an SRv6 behavior can support up to 64 attributes while on a 32-bit architecture it can support at most 32 attributes. To fool-proof the processing of SRv6 behaviors we verify, at compile time, that the set of all supported SRv6 attributes can be encoded into a bitmap stored in an unsigned long. Otherwise, kernel build fails forcing developers to reconsider adding a new attribute or extend the total number of supported attributes by the SRv6 behaviors. Moreover, we replace all patterns (1 << i) with the macro SEG6_F_ATTR(i) in order to address potential overflow issues caused by 32-bit signed arithmetic. Thanks to Colin Ian King for catching the overflow problem, providing a solution and inspiring this patch. Thanks to Jakub Kicinski for his useful suggestions during the design of this patch. v2: - remove the SEG6_LOCAL_MAX_SUPP which is not strictly needed: it can be derived from the unsigned long type. Thanks to David Ahern for pointing it out. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/r/20210206170934.5982-1-andrea.mayer@uniroma2.it Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-02-06 20:09:34 +03:00
.attrs = SEG6_F_ATTR(SEG6_LOCAL_TABLE),
seg6: add counters support for SRv6 Behaviors This patch provides counters for SRv6 Behaviors as defined in [1], section 6. For each SRv6 Behavior instance, counters defined in [1] are: - the total number of packets that have been correctly processed; - the total amount of traffic in bytes of all packets that have been correctly processed; In addition, this patch introduces a new counter that counts the number of packets that have NOT been properly processed (i.e. errors) by an SRv6 Behavior instance. Counters are not only interesting for network monitoring purposes (i.e. counting the number of packets processed by a given behavior) but they also provide a simple tool for checking whether a behavior instance is working as we expect or not. Counters can be useful for troubleshooting misconfigured SRv6 networks. Indeed, an SRv6 Behavior can silently drop packets for very different reasons (i.e. wrong SID configuration, interfaces set with SID addresses, etc) without any notification/message to the user. Due to the nature of SRv6 networks, diagnostic tools such as ping and traceroute may be ineffective: paths used for reaching a given router can be totally different from the ones followed by probe packets. In addition, paths are often asymmetrical and this makes it even more difficult to keep up with the journey of the packets and to understand which behaviors are actually processing our traffic. When counters are enabled on an SRv6 Behavior instance, it is possible to verify if packets are actually processed by such behavior and what is the outcome of the processing. Therefore, the counters for SRv6 Behaviors offer an non-invasive observability point which can be leveraged for both traffic monitoring and troubleshooting purposes. [1] https://www.rfc-editor.org/rfc/rfc8986.html#name-counters Troubleshooting using SRv6 Behavior counters -------------------------------------------- Let's make a brief example to see how helpful counters can be for SRv6 networks. Let's consider a node where an SRv6 End Behavior receives an SRv6 packet whose Segment Left (SL) is equal to 0. In this case, the End Behavior (which accepts only packets with SL >= 1) discards the packet and increases the error counter. This information can be leveraged by the network operator for troubleshooting. Indeed, the error counter is telling the user that the packet: (i) arrived at the node; (ii) the packet has been taken into account by the SRv6 End behavior; (iii) but an error has occurred during the processing. The error (iii) could be caused by different reasons, such as wrong route settings on the node or due to an invalid SID List carried by the SRv6 packet. Anyway, the error counter is used to exclude that the packet did not arrive at the node or it has not been processed by the behavior at all. Turning on/off counters for SRv6 Behaviors ------------------------------------------ Each SRv6 Behavior instance can be configured, at the time of its creation, to make use of counters. This is done through iproute2 which allows the user to create an SRv6 Behavior instance specifying the optional "count" attribute as shown in the following example: $ ip -6 route add 2001:db8::1 encap seg6local action End count dev eth0 per-behavior counters can be shown by adding "-s" to the iproute2 command line, i.e.: $ ip -s -6 route show 2001:db8::1 2001:db8::1 encap seg6local action End packets 0 bytes 0 errors 0 dev eth0 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Impact of counters for SRv6 Behaviors on performance ==================================================== To determine the performance impact due to the introduction of counters in the SRv6 Behavior subsystem, we have carried out extensive tests. We chose to test the throughput achieved by the SRv6 End.DX2 Behavior because, among all the other behaviors implemented so far, it reaches the highest throughput which is around 1.5 Mpps (per core at 2.4 GHz on a Xeon(R) CPU E5-2630 v3) on kernel 5.12-rc2 using packets of size ~ 100 bytes. Three different tests were conducted in order to evaluate the overall throughput of the SRv6 End.DX2 Behavior in the following scenarios: 1) vanilla kernel (without the SRv6 Behavior counters patch) and a single instance of an SRv6 End.DX2 Behavior; 2) patched kernel with SRv6 Behavior counters and a single instance of an SRv6 End.DX2 Behavior with counters turned off; 3) patched kernel with SRv6 Behavior counters and a single instance of SRv6 End.DX2 Behavior with counters turned on. All tests were performed on a testbed deployed on the CloudLab facilities [2], a flexible infrastructure dedicated to scientific research on the future of Cloud Computing. Results of tests are shown in the following table: Scenario (1): average 1504764,81 pps (~1504,76 kpps); std. dev 3956,82 pps Scenario (2): average 1501469,78 pps (~1501,47 kpps); std. dev 2979,85 pps Scenario (3): average 1501315,13 pps (~1501,32 kpps); std. dev 2956,00 pps As can be observed, throughputs achieved in scenarios (2),(3) did not suffer any observable degradation compared to scenario (1). Thanks to Jakub Kicinski and David Ahern for their valuable suggestions and comments provided during the discussion of the proposed RFCs. [2] https://www.cloudlab.us Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-04-27 18:44:04 +03:00
.optattrs = SEG6_F_LOCAL_COUNTERS,
ipv6: sr: implement additional seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END_T: regular SRH processing and forward to the next-hop looked up in the specified routing table. - SEG6_LOCAL_ACTION_END_DX2: decapsulate an L2 frame and forward it to the specified network interface. - SEG6_LOCAL_ACTION_END_DX4: decapsulate an IPv4 packet and forward it, possibly to the specified next-hop. - SEG6_LOCAL_ACTION_END_DT6: decapsulate an IPv6 packet and forward it to the next-hop looked up in the specified routing table. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 10:58:17 +03:00
.input = input_action_end_t,
},
{
.action = SEG6_LOCAL_ACTION_END_DX2,
seg6: fool-proof the processing of SRv6 behavior attributes The set of required attributes for a given SRv6 behavior is identified using a bitmap stored in an unsigned long, since the initial design of SRv6 networking in Linux. Recently the same approach has been used for identifying the optional attributes. However, the number of attributes supported by SRv6 behaviors depends on the size of the unsigned long type which changes with the architecture. Indeed, on a 64-bit architecture, an SRv6 behavior can support up to 64 attributes while on a 32-bit architecture it can support at most 32 attributes. To fool-proof the processing of SRv6 behaviors we verify, at compile time, that the set of all supported SRv6 attributes can be encoded into a bitmap stored in an unsigned long. Otherwise, kernel build fails forcing developers to reconsider adding a new attribute or extend the total number of supported attributes by the SRv6 behaviors. Moreover, we replace all patterns (1 << i) with the macro SEG6_F_ATTR(i) in order to address potential overflow issues caused by 32-bit signed arithmetic. Thanks to Colin Ian King for catching the overflow problem, providing a solution and inspiring this patch. Thanks to Jakub Kicinski for his useful suggestions during the design of this patch. v2: - remove the SEG6_LOCAL_MAX_SUPP which is not strictly needed: it can be derived from the unsigned long type. Thanks to David Ahern for pointing it out. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/r/20210206170934.5982-1-andrea.mayer@uniroma2.it Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-02-06 20:09:34 +03:00
.attrs = SEG6_F_ATTR(SEG6_LOCAL_OIF),
seg6: add counters support for SRv6 Behaviors This patch provides counters for SRv6 Behaviors as defined in [1], section 6. For each SRv6 Behavior instance, counters defined in [1] are: - the total number of packets that have been correctly processed; - the total amount of traffic in bytes of all packets that have been correctly processed; In addition, this patch introduces a new counter that counts the number of packets that have NOT been properly processed (i.e. errors) by an SRv6 Behavior instance. Counters are not only interesting for network monitoring purposes (i.e. counting the number of packets processed by a given behavior) but they also provide a simple tool for checking whether a behavior instance is working as we expect or not. Counters can be useful for troubleshooting misconfigured SRv6 networks. Indeed, an SRv6 Behavior can silently drop packets for very different reasons (i.e. wrong SID configuration, interfaces set with SID addresses, etc) without any notification/message to the user. Due to the nature of SRv6 networks, diagnostic tools such as ping and traceroute may be ineffective: paths used for reaching a given router can be totally different from the ones followed by probe packets. In addition, paths are often asymmetrical and this makes it even more difficult to keep up with the journey of the packets and to understand which behaviors are actually processing our traffic. When counters are enabled on an SRv6 Behavior instance, it is possible to verify if packets are actually processed by such behavior and what is the outcome of the processing. Therefore, the counters for SRv6 Behaviors offer an non-invasive observability point which can be leveraged for both traffic monitoring and troubleshooting purposes. [1] https://www.rfc-editor.org/rfc/rfc8986.html#name-counters Troubleshooting using SRv6 Behavior counters -------------------------------------------- Let's make a brief example to see how helpful counters can be for SRv6 networks. Let's consider a node where an SRv6 End Behavior receives an SRv6 packet whose Segment Left (SL) is equal to 0. In this case, the End Behavior (which accepts only packets with SL >= 1) discards the packet and increases the error counter. This information can be leveraged by the network operator for troubleshooting. Indeed, the error counter is telling the user that the packet: (i) arrived at the node; (ii) the packet has been taken into account by the SRv6 End behavior; (iii) but an error has occurred during the processing. The error (iii) could be caused by different reasons, such as wrong route settings on the node or due to an invalid SID List carried by the SRv6 packet. Anyway, the error counter is used to exclude that the packet did not arrive at the node or it has not been processed by the behavior at all. Turning on/off counters for SRv6 Behaviors ------------------------------------------ Each SRv6 Behavior instance can be configured, at the time of its creation, to make use of counters. This is done through iproute2 which allows the user to create an SRv6 Behavior instance specifying the optional "count" attribute as shown in the following example: $ ip -6 route add 2001:db8::1 encap seg6local action End count dev eth0 per-behavior counters can be shown by adding "-s" to the iproute2 command line, i.e.: $ ip -s -6 route show 2001:db8::1 2001:db8::1 encap seg6local action End packets 0 bytes 0 errors 0 dev eth0 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Impact of counters for SRv6 Behaviors on performance ==================================================== To determine the performance impact due to the introduction of counters in the SRv6 Behavior subsystem, we have carried out extensive tests. We chose to test the throughput achieved by the SRv6 End.DX2 Behavior because, among all the other behaviors implemented so far, it reaches the highest throughput which is around 1.5 Mpps (per core at 2.4 GHz on a Xeon(R) CPU E5-2630 v3) on kernel 5.12-rc2 using packets of size ~ 100 bytes. Three different tests were conducted in order to evaluate the overall throughput of the SRv6 End.DX2 Behavior in the following scenarios: 1) vanilla kernel (without the SRv6 Behavior counters patch) and a single instance of an SRv6 End.DX2 Behavior; 2) patched kernel with SRv6 Behavior counters and a single instance of an SRv6 End.DX2 Behavior with counters turned off; 3) patched kernel with SRv6 Behavior counters and a single instance of SRv6 End.DX2 Behavior with counters turned on. All tests were performed on a testbed deployed on the CloudLab facilities [2], a flexible infrastructure dedicated to scientific research on the future of Cloud Computing. Results of tests are shown in the following table: Scenario (1): average 1504764,81 pps (~1504,76 kpps); std. dev 3956,82 pps Scenario (2): average 1501469,78 pps (~1501,47 kpps); std. dev 2979,85 pps Scenario (3): average 1501315,13 pps (~1501,32 kpps); std. dev 2956,00 pps As can be observed, throughputs achieved in scenarios (2),(3) did not suffer any observable degradation compared to scenario (1). Thanks to Jakub Kicinski and David Ahern for their valuable suggestions and comments provided during the discussion of the proposed RFCs. [2] https://www.cloudlab.us Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-04-27 18:44:04 +03:00
.optattrs = SEG6_F_LOCAL_COUNTERS,
ipv6: sr: implement additional seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END_T: regular SRH processing and forward to the next-hop looked up in the specified routing table. - SEG6_LOCAL_ACTION_END_DX2: decapsulate an L2 frame and forward it to the specified network interface. - SEG6_LOCAL_ACTION_END_DX4: decapsulate an IPv4 packet and forward it, possibly to the specified next-hop. - SEG6_LOCAL_ACTION_END_DT6: decapsulate an IPv6 packet and forward it to the next-hop looked up in the specified routing table. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 10:58:17 +03:00
.input = input_action_end_dx2,
},
ipv6: sr: implement several seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END: regular SRH processing. The DA of the packet is updated to the next segment and forwarded accordingly. - SEG6_LOCAL_ACTION_END_X: same as above, except that the packet is forwarded to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_DX6: decapsulate the packet and forward to inner IPv6 packet to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_B6: insert the specified SRH directly after the IPv6 header of the packet. - SEG6_LOCAL_ACTION_END_B6_ENCAP: encapsulate the packet within an outer IPv6 header, containing the specified SRH. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:39:48 +03:00
{
.action = SEG6_LOCAL_ACTION_END_DX6,
seg6: fool-proof the processing of SRv6 behavior attributes The set of required attributes for a given SRv6 behavior is identified using a bitmap stored in an unsigned long, since the initial design of SRv6 networking in Linux. Recently the same approach has been used for identifying the optional attributes. However, the number of attributes supported by SRv6 behaviors depends on the size of the unsigned long type which changes with the architecture. Indeed, on a 64-bit architecture, an SRv6 behavior can support up to 64 attributes while on a 32-bit architecture it can support at most 32 attributes. To fool-proof the processing of SRv6 behaviors we verify, at compile time, that the set of all supported SRv6 attributes can be encoded into a bitmap stored in an unsigned long. Otherwise, kernel build fails forcing developers to reconsider adding a new attribute or extend the total number of supported attributes by the SRv6 behaviors. Moreover, we replace all patterns (1 << i) with the macro SEG6_F_ATTR(i) in order to address potential overflow issues caused by 32-bit signed arithmetic. Thanks to Colin Ian King for catching the overflow problem, providing a solution and inspiring this patch. Thanks to Jakub Kicinski for his useful suggestions during the design of this patch. v2: - remove the SEG6_LOCAL_MAX_SUPP which is not strictly needed: it can be derived from the unsigned long type. Thanks to David Ahern for pointing it out. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/r/20210206170934.5982-1-andrea.mayer@uniroma2.it Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-02-06 20:09:34 +03:00
.attrs = SEG6_F_ATTR(SEG6_LOCAL_NH6),
seg6: add counters support for SRv6 Behaviors This patch provides counters for SRv6 Behaviors as defined in [1], section 6. For each SRv6 Behavior instance, counters defined in [1] are: - the total number of packets that have been correctly processed; - the total amount of traffic in bytes of all packets that have been correctly processed; In addition, this patch introduces a new counter that counts the number of packets that have NOT been properly processed (i.e. errors) by an SRv6 Behavior instance. Counters are not only interesting for network monitoring purposes (i.e. counting the number of packets processed by a given behavior) but they also provide a simple tool for checking whether a behavior instance is working as we expect or not. Counters can be useful for troubleshooting misconfigured SRv6 networks. Indeed, an SRv6 Behavior can silently drop packets for very different reasons (i.e. wrong SID configuration, interfaces set with SID addresses, etc) without any notification/message to the user. Due to the nature of SRv6 networks, diagnostic tools such as ping and traceroute may be ineffective: paths used for reaching a given router can be totally different from the ones followed by probe packets. In addition, paths are often asymmetrical and this makes it even more difficult to keep up with the journey of the packets and to understand which behaviors are actually processing our traffic. When counters are enabled on an SRv6 Behavior instance, it is possible to verify if packets are actually processed by such behavior and what is the outcome of the processing. Therefore, the counters for SRv6 Behaviors offer an non-invasive observability point which can be leveraged for both traffic monitoring and troubleshooting purposes. [1] https://www.rfc-editor.org/rfc/rfc8986.html#name-counters Troubleshooting using SRv6 Behavior counters -------------------------------------------- Let's make a brief example to see how helpful counters can be for SRv6 networks. Let's consider a node where an SRv6 End Behavior receives an SRv6 packet whose Segment Left (SL) is equal to 0. In this case, the End Behavior (which accepts only packets with SL >= 1) discards the packet and increases the error counter. This information can be leveraged by the network operator for troubleshooting. Indeed, the error counter is telling the user that the packet: (i) arrived at the node; (ii) the packet has been taken into account by the SRv6 End behavior; (iii) but an error has occurred during the processing. The error (iii) could be caused by different reasons, such as wrong route settings on the node or due to an invalid SID List carried by the SRv6 packet. Anyway, the error counter is used to exclude that the packet did not arrive at the node or it has not been processed by the behavior at all. Turning on/off counters for SRv6 Behaviors ------------------------------------------ Each SRv6 Behavior instance can be configured, at the time of its creation, to make use of counters. This is done through iproute2 which allows the user to create an SRv6 Behavior instance specifying the optional "count" attribute as shown in the following example: $ ip -6 route add 2001:db8::1 encap seg6local action End count dev eth0 per-behavior counters can be shown by adding "-s" to the iproute2 command line, i.e.: $ ip -s -6 route show 2001:db8::1 2001:db8::1 encap seg6local action End packets 0 bytes 0 errors 0 dev eth0 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Impact of counters for SRv6 Behaviors on performance ==================================================== To determine the performance impact due to the introduction of counters in the SRv6 Behavior subsystem, we have carried out extensive tests. We chose to test the throughput achieved by the SRv6 End.DX2 Behavior because, among all the other behaviors implemented so far, it reaches the highest throughput which is around 1.5 Mpps (per core at 2.4 GHz on a Xeon(R) CPU E5-2630 v3) on kernel 5.12-rc2 using packets of size ~ 100 bytes. Three different tests were conducted in order to evaluate the overall throughput of the SRv6 End.DX2 Behavior in the following scenarios: 1) vanilla kernel (without the SRv6 Behavior counters patch) and a single instance of an SRv6 End.DX2 Behavior; 2) patched kernel with SRv6 Behavior counters and a single instance of an SRv6 End.DX2 Behavior with counters turned off; 3) patched kernel with SRv6 Behavior counters and a single instance of SRv6 End.DX2 Behavior with counters turned on. All tests were performed on a testbed deployed on the CloudLab facilities [2], a flexible infrastructure dedicated to scientific research on the future of Cloud Computing. Results of tests are shown in the following table: Scenario (1): average 1504764,81 pps (~1504,76 kpps); std. dev 3956,82 pps Scenario (2): average 1501469,78 pps (~1501,47 kpps); std. dev 2979,85 pps Scenario (3): average 1501315,13 pps (~1501,32 kpps); std. dev 2956,00 pps As can be observed, throughputs achieved in scenarios (2),(3) did not suffer any observable degradation compared to scenario (1). Thanks to Jakub Kicinski and David Ahern for their valuable suggestions and comments provided during the discussion of the proposed RFCs. [2] https://www.cloudlab.us Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-04-27 18:44:04 +03:00
.optattrs = SEG6_F_LOCAL_COUNTERS,
ipv6: sr: implement several seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END: regular SRH processing. The DA of the packet is updated to the next segment and forwarded accordingly. - SEG6_LOCAL_ACTION_END_X: same as above, except that the packet is forwarded to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_DX6: decapsulate the packet and forward to inner IPv6 packet to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_B6: insert the specified SRH directly after the IPv6 header of the packet. - SEG6_LOCAL_ACTION_END_B6_ENCAP: encapsulate the packet within an outer IPv6 header, containing the specified SRH. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:39:48 +03:00
.input = input_action_end_dx6,
},
ipv6: sr: implement additional seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END_T: regular SRH processing and forward to the next-hop looked up in the specified routing table. - SEG6_LOCAL_ACTION_END_DX2: decapsulate an L2 frame and forward it to the specified network interface. - SEG6_LOCAL_ACTION_END_DX4: decapsulate an IPv4 packet and forward it, possibly to the specified next-hop. - SEG6_LOCAL_ACTION_END_DT6: decapsulate an IPv6 packet and forward it to the next-hop looked up in the specified routing table. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 10:58:17 +03:00
{
.action = SEG6_LOCAL_ACTION_END_DX4,
seg6: fool-proof the processing of SRv6 behavior attributes The set of required attributes for a given SRv6 behavior is identified using a bitmap stored in an unsigned long, since the initial design of SRv6 networking in Linux. Recently the same approach has been used for identifying the optional attributes. However, the number of attributes supported by SRv6 behaviors depends on the size of the unsigned long type which changes with the architecture. Indeed, on a 64-bit architecture, an SRv6 behavior can support up to 64 attributes while on a 32-bit architecture it can support at most 32 attributes. To fool-proof the processing of SRv6 behaviors we verify, at compile time, that the set of all supported SRv6 attributes can be encoded into a bitmap stored in an unsigned long. Otherwise, kernel build fails forcing developers to reconsider adding a new attribute or extend the total number of supported attributes by the SRv6 behaviors. Moreover, we replace all patterns (1 << i) with the macro SEG6_F_ATTR(i) in order to address potential overflow issues caused by 32-bit signed arithmetic. Thanks to Colin Ian King for catching the overflow problem, providing a solution and inspiring this patch. Thanks to Jakub Kicinski for his useful suggestions during the design of this patch. v2: - remove the SEG6_LOCAL_MAX_SUPP which is not strictly needed: it can be derived from the unsigned long type. Thanks to David Ahern for pointing it out. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/r/20210206170934.5982-1-andrea.mayer@uniroma2.it Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-02-06 20:09:34 +03:00
.attrs = SEG6_F_ATTR(SEG6_LOCAL_NH4),
seg6: add counters support for SRv6 Behaviors This patch provides counters for SRv6 Behaviors as defined in [1], section 6. For each SRv6 Behavior instance, counters defined in [1] are: - the total number of packets that have been correctly processed; - the total amount of traffic in bytes of all packets that have been correctly processed; In addition, this patch introduces a new counter that counts the number of packets that have NOT been properly processed (i.e. errors) by an SRv6 Behavior instance. Counters are not only interesting for network monitoring purposes (i.e. counting the number of packets processed by a given behavior) but they also provide a simple tool for checking whether a behavior instance is working as we expect or not. Counters can be useful for troubleshooting misconfigured SRv6 networks. Indeed, an SRv6 Behavior can silently drop packets for very different reasons (i.e. wrong SID configuration, interfaces set with SID addresses, etc) without any notification/message to the user. Due to the nature of SRv6 networks, diagnostic tools such as ping and traceroute may be ineffective: paths used for reaching a given router can be totally different from the ones followed by probe packets. In addition, paths are often asymmetrical and this makes it even more difficult to keep up with the journey of the packets and to understand which behaviors are actually processing our traffic. When counters are enabled on an SRv6 Behavior instance, it is possible to verify if packets are actually processed by such behavior and what is the outcome of the processing. Therefore, the counters for SRv6 Behaviors offer an non-invasive observability point which can be leveraged for both traffic monitoring and troubleshooting purposes. [1] https://www.rfc-editor.org/rfc/rfc8986.html#name-counters Troubleshooting using SRv6 Behavior counters -------------------------------------------- Let's make a brief example to see how helpful counters can be for SRv6 networks. Let's consider a node where an SRv6 End Behavior receives an SRv6 packet whose Segment Left (SL) is equal to 0. In this case, the End Behavior (which accepts only packets with SL >= 1) discards the packet and increases the error counter. This information can be leveraged by the network operator for troubleshooting. Indeed, the error counter is telling the user that the packet: (i) arrived at the node; (ii) the packet has been taken into account by the SRv6 End behavior; (iii) but an error has occurred during the processing. The error (iii) could be caused by different reasons, such as wrong route settings on the node or due to an invalid SID List carried by the SRv6 packet. Anyway, the error counter is used to exclude that the packet did not arrive at the node or it has not been processed by the behavior at all. Turning on/off counters for SRv6 Behaviors ------------------------------------------ Each SRv6 Behavior instance can be configured, at the time of its creation, to make use of counters. This is done through iproute2 which allows the user to create an SRv6 Behavior instance specifying the optional "count" attribute as shown in the following example: $ ip -6 route add 2001:db8::1 encap seg6local action End count dev eth0 per-behavior counters can be shown by adding "-s" to the iproute2 command line, i.e.: $ ip -s -6 route show 2001:db8::1 2001:db8::1 encap seg6local action End packets 0 bytes 0 errors 0 dev eth0 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Impact of counters for SRv6 Behaviors on performance ==================================================== To determine the performance impact due to the introduction of counters in the SRv6 Behavior subsystem, we have carried out extensive tests. We chose to test the throughput achieved by the SRv6 End.DX2 Behavior because, among all the other behaviors implemented so far, it reaches the highest throughput which is around 1.5 Mpps (per core at 2.4 GHz on a Xeon(R) CPU E5-2630 v3) on kernel 5.12-rc2 using packets of size ~ 100 bytes. Three different tests were conducted in order to evaluate the overall throughput of the SRv6 End.DX2 Behavior in the following scenarios: 1) vanilla kernel (without the SRv6 Behavior counters patch) and a single instance of an SRv6 End.DX2 Behavior; 2) patched kernel with SRv6 Behavior counters and a single instance of an SRv6 End.DX2 Behavior with counters turned off; 3) patched kernel with SRv6 Behavior counters and a single instance of SRv6 End.DX2 Behavior with counters turned on. All tests were performed on a testbed deployed on the CloudLab facilities [2], a flexible infrastructure dedicated to scientific research on the future of Cloud Computing. Results of tests are shown in the following table: Scenario (1): average 1504764,81 pps (~1504,76 kpps); std. dev 3956,82 pps Scenario (2): average 1501469,78 pps (~1501,47 kpps); std. dev 2979,85 pps Scenario (3): average 1501315,13 pps (~1501,32 kpps); std. dev 2956,00 pps As can be observed, throughputs achieved in scenarios (2),(3) did not suffer any observable degradation compared to scenario (1). Thanks to Jakub Kicinski and David Ahern for their valuable suggestions and comments provided during the discussion of the proposed RFCs. [2] https://www.cloudlab.us Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-04-27 18:44:04 +03:00
.optattrs = SEG6_F_LOCAL_COUNTERS,
ipv6: sr: implement additional seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END_T: regular SRH processing and forward to the next-hop looked up in the specified routing table. - SEG6_LOCAL_ACTION_END_DX2: decapsulate an L2 frame and forward it to the specified network interface. - SEG6_LOCAL_ACTION_END_DX4: decapsulate an IPv4 packet and forward it, possibly to the specified next-hop. - SEG6_LOCAL_ACTION_END_DT6: decapsulate an IPv6 packet and forward it to the next-hop looked up in the specified routing table. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 10:58:17 +03:00
.input = input_action_end_dx4,
},
seg6: add support for the SRv6 End.DT4 behavior SRv6 End.DT4 is defined in the SRv6 Network Programming [1]. The SRv6 End.DT4 is used to implement IPv4 L3VPN use-cases in multi-tenants environments. It decapsulates the received packets and it performs IPv4 routing lookup in the routing table of the tenant. The SRv6 End.DT4 Linux implementation leverages a VRF device in order to force the routing lookup into the associated routing table. To make the End.DT4 work properly, it must be guaranteed that the routing table used for routing lookup operations is bound to one and only one VRF during the tunnel creation. Such constraint has to be enforced by enabling the VRF strict_mode sysctl parameter, i.e: $ sysctl -wq net.vrf.strict_mode=1. At JANOG44, LINE corporation presented their multi-tenant DC architecture using SRv6 [2]. In the slides, they reported that the Linux kernel is missing the support of SRv6 End.DT4 behavior. The SRv6 End.DT4 behavior can be instantiated using a command similar to the following: $ ip route add 2001:db8::1 encap seg6local action End.DT4 vrftable 100 dev eth0 We introduce the "vrftable" extension in iproute2 in a following patch. [1] https://tools.ietf.org/html/draft-ietf-spring-srv6-network-programming [2] https://speakerdeck.com/line_developers/line-data-center-networking-with-srv6 Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:14 +03:00
{
.action = SEG6_LOCAL_ACTION_END_DT4,
seg6: fool-proof the processing of SRv6 behavior attributes The set of required attributes for a given SRv6 behavior is identified using a bitmap stored in an unsigned long, since the initial design of SRv6 networking in Linux. Recently the same approach has been used for identifying the optional attributes. However, the number of attributes supported by SRv6 behaviors depends on the size of the unsigned long type which changes with the architecture. Indeed, on a 64-bit architecture, an SRv6 behavior can support up to 64 attributes while on a 32-bit architecture it can support at most 32 attributes. To fool-proof the processing of SRv6 behaviors we verify, at compile time, that the set of all supported SRv6 attributes can be encoded into a bitmap stored in an unsigned long. Otherwise, kernel build fails forcing developers to reconsider adding a new attribute or extend the total number of supported attributes by the SRv6 behaviors. Moreover, we replace all patterns (1 << i) with the macro SEG6_F_ATTR(i) in order to address potential overflow issues caused by 32-bit signed arithmetic. Thanks to Colin Ian King for catching the overflow problem, providing a solution and inspiring this patch. Thanks to Jakub Kicinski for his useful suggestions during the design of this patch. v2: - remove the SEG6_LOCAL_MAX_SUPP which is not strictly needed: it can be derived from the unsigned long type. Thanks to David Ahern for pointing it out. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/r/20210206170934.5982-1-andrea.mayer@uniroma2.it Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-02-06 20:09:34 +03:00
.attrs = SEG6_F_ATTR(SEG6_LOCAL_VRFTABLE),
seg6: add counters support for SRv6 Behaviors This patch provides counters for SRv6 Behaviors as defined in [1], section 6. For each SRv6 Behavior instance, counters defined in [1] are: - the total number of packets that have been correctly processed; - the total amount of traffic in bytes of all packets that have been correctly processed; In addition, this patch introduces a new counter that counts the number of packets that have NOT been properly processed (i.e. errors) by an SRv6 Behavior instance. Counters are not only interesting for network monitoring purposes (i.e. counting the number of packets processed by a given behavior) but they also provide a simple tool for checking whether a behavior instance is working as we expect or not. Counters can be useful for troubleshooting misconfigured SRv6 networks. Indeed, an SRv6 Behavior can silently drop packets for very different reasons (i.e. wrong SID configuration, interfaces set with SID addresses, etc) without any notification/message to the user. Due to the nature of SRv6 networks, diagnostic tools such as ping and traceroute may be ineffective: paths used for reaching a given router can be totally different from the ones followed by probe packets. In addition, paths are often asymmetrical and this makes it even more difficult to keep up with the journey of the packets and to understand which behaviors are actually processing our traffic. When counters are enabled on an SRv6 Behavior instance, it is possible to verify if packets are actually processed by such behavior and what is the outcome of the processing. Therefore, the counters for SRv6 Behaviors offer an non-invasive observability point which can be leveraged for both traffic monitoring and troubleshooting purposes. [1] https://www.rfc-editor.org/rfc/rfc8986.html#name-counters Troubleshooting using SRv6 Behavior counters -------------------------------------------- Let's make a brief example to see how helpful counters can be for SRv6 networks. Let's consider a node where an SRv6 End Behavior receives an SRv6 packet whose Segment Left (SL) is equal to 0. In this case, the End Behavior (which accepts only packets with SL >= 1) discards the packet and increases the error counter. This information can be leveraged by the network operator for troubleshooting. Indeed, the error counter is telling the user that the packet: (i) arrived at the node; (ii) the packet has been taken into account by the SRv6 End behavior; (iii) but an error has occurred during the processing. The error (iii) could be caused by different reasons, such as wrong route settings on the node or due to an invalid SID List carried by the SRv6 packet. Anyway, the error counter is used to exclude that the packet did not arrive at the node or it has not been processed by the behavior at all. Turning on/off counters for SRv6 Behaviors ------------------------------------------ Each SRv6 Behavior instance can be configured, at the time of its creation, to make use of counters. This is done through iproute2 which allows the user to create an SRv6 Behavior instance specifying the optional "count" attribute as shown in the following example: $ ip -6 route add 2001:db8::1 encap seg6local action End count dev eth0 per-behavior counters can be shown by adding "-s" to the iproute2 command line, i.e.: $ ip -s -6 route show 2001:db8::1 2001:db8::1 encap seg6local action End packets 0 bytes 0 errors 0 dev eth0 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Impact of counters for SRv6 Behaviors on performance ==================================================== To determine the performance impact due to the introduction of counters in the SRv6 Behavior subsystem, we have carried out extensive tests. We chose to test the throughput achieved by the SRv6 End.DX2 Behavior because, among all the other behaviors implemented so far, it reaches the highest throughput which is around 1.5 Mpps (per core at 2.4 GHz on a Xeon(R) CPU E5-2630 v3) on kernel 5.12-rc2 using packets of size ~ 100 bytes. Three different tests were conducted in order to evaluate the overall throughput of the SRv6 End.DX2 Behavior in the following scenarios: 1) vanilla kernel (without the SRv6 Behavior counters patch) and a single instance of an SRv6 End.DX2 Behavior; 2) patched kernel with SRv6 Behavior counters and a single instance of an SRv6 End.DX2 Behavior with counters turned off; 3) patched kernel with SRv6 Behavior counters and a single instance of SRv6 End.DX2 Behavior with counters turned on. All tests were performed on a testbed deployed on the CloudLab facilities [2], a flexible infrastructure dedicated to scientific research on the future of Cloud Computing. Results of tests are shown in the following table: Scenario (1): average 1504764,81 pps (~1504,76 kpps); std. dev 3956,82 pps Scenario (2): average 1501469,78 pps (~1501,47 kpps); std. dev 2979,85 pps Scenario (3): average 1501315,13 pps (~1501,32 kpps); std. dev 2956,00 pps As can be observed, throughputs achieved in scenarios (2),(3) did not suffer any observable degradation compared to scenario (1). Thanks to Jakub Kicinski and David Ahern for their valuable suggestions and comments provided during the discussion of the proposed RFCs. [2] https://www.cloudlab.us Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-04-27 18:44:04 +03:00
.optattrs = SEG6_F_LOCAL_COUNTERS,
seg6: add support for the SRv6 End.DT4 behavior SRv6 End.DT4 is defined in the SRv6 Network Programming [1]. The SRv6 End.DT4 is used to implement IPv4 L3VPN use-cases in multi-tenants environments. It decapsulates the received packets and it performs IPv4 routing lookup in the routing table of the tenant. The SRv6 End.DT4 Linux implementation leverages a VRF device in order to force the routing lookup into the associated routing table. To make the End.DT4 work properly, it must be guaranteed that the routing table used for routing lookup operations is bound to one and only one VRF during the tunnel creation. Such constraint has to be enforced by enabling the VRF strict_mode sysctl parameter, i.e: $ sysctl -wq net.vrf.strict_mode=1. At JANOG44, LINE corporation presented their multi-tenant DC architecture using SRv6 [2]. In the slides, they reported that the Linux kernel is missing the support of SRv6 End.DT4 behavior. The SRv6 End.DT4 behavior can be instantiated using a command similar to the following: $ ip route add 2001:db8::1 encap seg6local action End.DT4 vrftable 100 dev eth0 We introduce the "vrftable" extension in iproute2 in a following patch. [1] https://tools.ietf.org/html/draft-ietf-spring-srv6-network-programming [2] https://speakerdeck.com/line_developers/line-data-center-networking-with-srv6 Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:14 +03:00
#ifdef CONFIG_NET_L3_MASTER_DEV
.input = input_action_end_dt4,
.slwt_ops = {
.build_state = seg6_end_dt4_build,
},
#endif
},
ipv6: sr: implement additional seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END_T: regular SRH processing and forward to the next-hop looked up in the specified routing table. - SEG6_LOCAL_ACTION_END_DX2: decapsulate an L2 frame and forward it to the specified network interface. - SEG6_LOCAL_ACTION_END_DX4: decapsulate an IPv4 packet and forward it, possibly to the specified next-hop. - SEG6_LOCAL_ACTION_END_DT6: decapsulate an IPv6 packet and forward it to the next-hop looked up in the specified routing table. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 10:58:17 +03:00
{
.action = SEG6_LOCAL_ACTION_END_DT6,
seg6: add VRF support for SRv6 End.DT6 behavior SRv6 End.DT6 is defined in the SRv6 Network Programming [1]. The Linux kernel already offers an implementation of the SRv6 End.DT6 behavior which permits IPv6 L3 VPNs over SRv6 networks. This implementation is not particularly suitable in contexts where we need to deploy IPv6 L3 VPNs among different tenants which share the same network address schemes. The underlying problem lies in the fact that the current version of DT6 (called legacy DT6 from now on) needs a complex configuration to be applied on routers which requires ad-hoc routes and routing policy rules to ensure the correct isolation of tenants. Consequently, a new implementation of DT6 has been introduced with the aim of simplifying the construction of IPv6 L3 VPN services in the multi-tenant environment using SRv6 networks. To accomplish this task, we reused the same VRF infrastructure and SRv6 core components already exploited for implementing the SRv6 End.DT4 behavior. Currently the two End.DT6 implementations coexist seamlessly and can be used depending on the context and the user preferences. So, in order to support both versions of DT6 a new attribute (vrftable) has been introduced which allows us to differentiate the implementation of the behavior to be used. A SRv6 End.DT6 legacy behavior is still instantiated using a command like the following one: $ ip -6 route add 2001:db8::1 encap seg6local action End.DT6 table 100 dev eth0 While to instantiate the SRv6 End.DT6 in VRF mode, the command is still pretty straight forward: $ ip -6 route add 2001:db8::1 encap seg6local action End.DT6 vrftable 100 dev eth0. Obviously as in the case of SRv6 End.DT4, the VRF strict_mode parameter must be set (net.vrf.strict_mode=1) and the VRF associated with table 100 must exist. Please note that the instances of SRv6 End.DT6 legacy and End.DT6 VRF mode can coexist in the same system/configuration without problems. [1] https://tools.ietf.org/html/draft-ietf-spring-srv6-network-programming Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:15 +03:00
#ifdef CONFIG_NET_L3_MASTER_DEV
.attrs = 0,
seg6: add counters support for SRv6 Behaviors This patch provides counters for SRv6 Behaviors as defined in [1], section 6. For each SRv6 Behavior instance, counters defined in [1] are: - the total number of packets that have been correctly processed; - the total amount of traffic in bytes of all packets that have been correctly processed; In addition, this patch introduces a new counter that counts the number of packets that have NOT been properly processed (i.e. errors) by an SRv6 Behavior instance. Counters are not only interesting for network monitoring purposes (i.e. counting the number of packets processed by a given behavior) but they also provide a simple tool for checking whether a behavior instance is working as we expect or not. Counters can be useful for troubleshooting misconfigured SRv6 networks. Indeed, an SRv6 Behavior can silently drop packets for very different reasons (i.e. wrong SID configuration, interfaces set with SID addresses, etc) without any notification/message to the user. Due to the nature of SRv6 networks, diagnostic tools such as ping and traceroute may be ineffective: paths used for reaching a given router can be totally different from the ones followed by probe packets. In addition, paths are often asymmetrical and this makes it even more difficult to keep up with the journey of the packets and to understand which behaviors are actually processing our traffic. When counters are enabled on an SRv6 Behavior instance, it is possible to verify if packets are actually processed by such behavior and what is the outcome of the processing. Therefore, the counters for SRv6 Behaviors offer an non-invasive observability point which can be leveraged for both traffic monitoring and troubleshooting purposes. [1] https://www.rfc-editor.org/rfc/rfc8986.html#name-counters Troubleshooting using SRv6 Behavior counters -------------------------------------------- Let's make a brief example to see how helpful counters can be for SRv6 networks. Let's consider a node where an SRv6 End Behavior receives an SRv6 packet whose Segment Left (SL) is equal to 0. In this case, the End Behavior (which accepts only packets with SL >= 1) discards the packet and increases the error counter. This information can be leveraged by the network operator for troubleshooting. Indeed, the error counter is telling the user that the packet: (i) arrived at the node; (ii) the packet has been taken into account by the SRv6 End behavior; (iii) but an error has occurred during the processing. The error (iii) could be caused by different reasons, such as wrong route settings on the node or due to an invalid SID List carried by the SRv6 packet. Anyway, the error counter is used to exclude that the packet did not arrive at the node or it has not been processed by the behavior at all. Turning on/off counters for SRv6 Behaviors ------------------------------------------ Each SRv6 Behavior instance can be configured, at the time of its creation, to make use of counters. This is done through iproute2 which allows the user to create an SRv6 Behavior instance specifying the optional "count" attribute as shown in the following example: $ ip -6 route add 2001:db8::1 encap seg6local action End count dev eth0 per-behavior counters can be shown by adding "-s" to the iproute2 command line, i.e.: $ ip -s -6 route show 2001:db8::1 2001:db8::1 encap seg6local action End packets 0 bytes 0 errors 0 dev eth0 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Impact of counters for SRv6 Behaviors on performance ==================================================== To determine the performance impact due to the introduction of counters in the SRv6 Behavior subsystem, we have carried out extensive tests. We chose to test the throughput achieved by the SRv6 End.DX2 Behavior because, among all the other behaviors implemented so far, it reaches the highest throughput which is around 1.5 Mpps (per core at 2.4 GHz on a Xeon(R) CPU E5-2630 v3) on kernel 5.12-rc2 using packets of size ~ 100 bytes. Three different tests were conducted in order to evaluate the overall throughput of the SRv6 End.DX2 Behavior in the following scenarios: 1) vanilla kernel (without the SRv6 Behavior counters patch) and a single instance of an SRv6 End.DX2 Behavior; 2) patched kernel with SRv6 Behavior counters and a single instance of an SRv6 End.DX2 Behavior with counters turned off; 3) patched kernel with SRv6 Behavior counters and a single instance of SRv6 End.DX2 Behavior with counters turned on. All tests were performed on a testbed deployed on the CloudLab facilities [2], a flexible infrastructure dedicated to scientific research on the future of Cloud Computing. Results of tests are shown in the following table: Scenario (1): average 1504764,81 pps (~1504,76 kpps); std. dev 3956,82 pps Scenario (2): average 1501469,78 pps (~1501,47 kpps); std. dev 2979,85 pps Scenario (3): average 1501315,13 pps (~1501,32 kpps); std. dev 2956,00 pps As can be observed, throughputs achieved in scenarios (2),(3) did not suffer any observable degradation compared to scenario (1). Thanks to Jakub Kicinski and David Ahern for their valuable suggestions and comments provided during the discussion of the proposed RFCs. [2] https://www.cloudlab.us Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-04-27 18:44:04 +03:00
.optattrs = SEG6_F_LOCAL_COUNTERS |
SEG6_F_ATTR(SEG6_LOCAL_TABLE) |
seg6: fool-proof the processing of SRv6 behavior attributes The set of required attributes for a given SRv6 behavior is identified using a bitmap stored in an unsigned long, since the initial design of SRv6 networking in Linux. Recently the same approach has been used for identifying the optional attributes. However, the number of attributes supported by SRv6 behaviors depends on the size of the unsigned long type which changes with the architecture. Indeed, on a 64-bit architecture, an SRv6 behavior can support up to 64 attributes while on a 32-bit architecture it can support at most 32 attributes. To fool-proof the processing of SRv6 behaviors we verify, at compile time, that the set of all supported SRv6 attributes can be encoded into a bitmap stored in an unsigned long. Otherwise, kernel build fails forcing developers to reconsider adding a new attribute or extend the total number of supported attributes by the SRv6 behaviors. Moreover, we replace all patterns (1 << i) with the macro SEG6_F_ATTR(i) in order to address potential overflow issues caused by 32-bit signed arithmetic. Thanks to Colin Ian King for catching the overflow problem, providing a solution and inspiring this patch. Thanks to Jakub Kicinski for his useful suggestions during the design of this patch. v2: - remove the SEG6_LOCAL_MAX_SUPP which is not strictly needed: it can be derived from the unsigned long type. Thanks to David Ahern for pointing it out. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/r/20210206170934.5982-1-andrea.mayer@uniroma2.it Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-02-06 20:09:34 +03:00
SEG6_F_ATTR(SEG6_LOCAL_VRFTABLE),
seg6: add VRF support for SRv6 End.DT6 behavior SRv6 End.DT6 is defined in the SRv6 Network Programming [1]. The Linux kernel already offers an implementation of the SRv6 End.DT6 behavior which permits IPv6 L3 VPNs over SRv6 networks. This implementation is not particularly suitable in contexts where we need to deploy IPv6 L3 VPNs among different tenants which share the same network address schemes. The underlying problem lies in the fact that the current version of DT6 (called legacy DT6 from now on) needs a complex configuration to be applied on routers which requires ad-hoc routes and routing policy rules to ensure the correct isolation of tenants. Consequently, a new implementation of DT6 has been introduced with the aim of simplifying the construction of IPv6 L3 VPN services in the multi-tenant environment using SRv6 networks. To accomplish this task, we reused the same VRF infrastructure and SRv6 core components already exploited for implementing the SRv6 End.DT4 behavior. Currently the two End.DT6 implementations coexist seamlessly and can be used depending on the context and the user preferences. So, in order to support both versions of DT6 a new attribute (vrftable) has been introduced which allows us to differentiate the implementation of the behavior to be used. A SRv6 End.DT6 legacy behavior is still instantiated using a command like the following one: $ ip -6 route add 2001:db8::1 encap seg6local action End.DT6 table 100 dev eth0 While to instantiate the SRv6 End.DT6 in VRF mode, the command is still pretty straight forward: $ ip -6 route add 2001:db8::1 encap seg6local action End.DT6 vrftable 100 dev eth0. Obviously as in the case of SRv6 End.DT4, the VRF strict_mode parameter must be set (net.vrf.strict_mode=1) and the VRF associated with table 100 must exist. Please note that the instances of SRv6 End.DT6 legacy and End.DT6 VRF mode can coexist in the same system/configuration without problems. [1] https://tools.ietf.org/html/draft-ietf-spring-srv6-network-programming Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:15 +03:00
.slwt_ops = {
.build_state = seg6_end_dt6_build,
},
#else
seg6: fool-proof the processing of SRv6 behavior attributes The set of required attributes for a given SRv6 behavior is identified using a bitmap stored in an unsigned long, since the initial design of SRv6 networking in Linux. Recently the same approach has been used for identifying the optional attributes. However, the number of attributes supported by SRv6 behaviors depends on the size of the unsigned long type which changes with the architecture. Indeed, on a 64-bit architecture, an SRv6 behavior can support up to 64 attributes while on a 32-bit architecture it can support at most 32 attributes. To fool-proof the processing of SRv6 behaviors we verify, at compile time, that the set of all supported SRv6 attributes can be encoded into a bitmap stored in an unsigned long. Otherwise, kernel build fails forcing developers to reconsider adding a new attribute or extend the total number of supported attributes by the SRv6 behaviors. Moreover, we replace all patterns (1 << i) with the macro SEG6_F_ATTR(i) in order to address potential overflow issues caused by 32-bit signed arithmetic. Thanks to Colin Ian King for catching the overflow problem, providing a solution and inspiring this patch. Thanks to Jakub Kicinski for his useful suggestions during the design of this patch. v2: - remove the SEG6_LOCAL_MAX_SUPP which is not strictly needed: it can be derived from the unsigned long type. Thanks to David Ahern for pointing it out. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/r/20210206170934.5982-1-andrea.mayer@uniroma2.it Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-02-06 20:09:34 +03:00
.attrs = SEG6_F_ATTR(SEG6_LOCAL_TABLE),
seg6: add counters support for SRv6 Behaviors This patch provides counters for SRv6 Behaviors as defined in [1], section 6. For each SRv6 Behavior instance, counters defined in [1] are: - the total number of packets that have been correctly processed; - the total amount of traffic in bytes of all packets that have been correctly processed; In addition, this patch introduces a new counter that counts the number of packets that have NOT been properly processed (i.e. errors) by an SRv6 Behavior instance. Counters are not only interesting for network monitoring purposes (i.e. counting the number of packets processed by a given behavior) but they also provide a simple tool for checking whether a behavior instance is working as we expect or not. Counters can be useful for troubleshooting misconfigured SRv6 networks. Indeed, an SRv6 Behavior can silently drop packets for very different reasons (i.e. wrong SID configuration, interfaces set with SID addresses, etc) without any notification/message to the user. Due to the nature of SRv6 networks, diagnostic tools such as ping and traceroute may be ineffective: paths used for reaching a given router can be totally different from the ones followed by probe packets. In addition, paths are often asymmetrical and this makes it even more difficult to keep up with the journey of the packets and to understand which behaviors are actually processing our traffic. When counters are enabled on an SRv6 Behavior instance, it is possible to verify if packets are actually processed by such behavior and what is the outcome of the processing. Therefore, the counters for SRv6 Behaviors offer an non-invasive observability point which can be leveraged for both traffic monitoring and troubleshooting purposes. [1] https://www.rfc-editor.org/rfc/rfc8986.html#name-counters Troubleshooting using SRv6 Behavior counters -------------------------------------------- Let's make a brief example to see how helpful counters can be for SRv6 networks. Let's consider a node where an SRv6 End Behavior receives an SRv6 packet whose Segment Left (SL) is equal to 0. In this case, the End Behavior (which accepts only packets with SL >= 1) discards the packet and increases the error counter. This information can be leveraged by the network operator for troubleshooting. Indeed, the error counter is telling the user that the packet: (i) arrived at the node; (ii) the packet has been taken into account by the SRv6 End behavior; (iii) but an error has occurred during the processing. The error (iii) could be caused by different reasons, such as wrong route settings on the node or due to an invalid SID List carried by the SRv6 packet. Anyway, the error counter is used to exclude that the packet did not arrive at the node or it has not been processed by the behavior at all. Turning on/off counters for SRv6 Behaviors ------------------------------------------ Each SRv6 Behavior instance can be configured, at the time of its creation, to make use of counters. This is done through iproute2 which allows the user to create an SRv6 Behavior instance specifying the optional "count" attribute as shown in the following example: $ ip -6 route add 2001:db8::1 encap seg6local action End count dev eth0 per-behavior counters can be shown by adding "-s" to the iproute2 command line, i.e.: $ ip -s -6 route show 2001:db8::1 2001:db8::1 encap seg6local action End packets 0 bytes 0 errors 0 dev eth0 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Impact of counters for SRv6 Behaviors on performance ==================================================== To determine the performance impact due to the introduction of counters in the SRv6 Behavior subsystem, we have carried out extensive tests. We chose to test the throughput achieved by the SRv6 End.DX2 Behavior because, among all the other behaviors implemented so far, it reaches the highest throughput which is around 1.5 Mpps (per core at 2.4 GHz on a Xeon(R) CPU E5-2630 v3) on kernel 5.12-rc2 using packets of size ~ 100 bytes. Three different tests were conducted in order to evaluate the overall throughput of the SRv6 End.DX2 Behavior in the following scenarios: 1) vanilla kernel (without the SRv6 Behavior counters patch) and a single instance of an SRv6 End.DX2 Behavior; 2) patched kernel with SRv6 Behavior counters and a single instance of an SRv6 End.DX2 Behavior with counters turned off; 3) patched kernel with SRv6 Behavior counters and a single instance of SRv6 End.DX2 Behavior with counters turned on. All tests were performed on a testbed deployed on the CloudLab facilities [2], a flexible infrastructure dedicated to scientific research on the future of Cloud Computing. Results of tests are shown in the following table: Scenario (1): average 1504764,81 pps (~1504,76 kpps); std. dev 3956,82 pps Scenario (2): average 1501469,78 pps (~1501,47 kpps); std. dev 2979,85 pps Scenario (3): average 1501315,13 pps (~1501,32 kpps); std. dev 2956,00 pps As can be observed, throughputs achieved in scenarios (2),(3) did not suffer any observable degradation compared to scenario (1). Thanks to Jakub Kicinski and David Ahern for their valuable suggestions and comments provided during the discussion of the proposed RFCs. [2] https://www.cloudlab.us Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-04-27 18:44:04 +03:00
.optattrs = SEG6_F_LOCAL_COUNTERS,
seg6: add VRF support for SRv6 End.DT6 behavior SRv6 End.DT6 is defined in the SRv6 Network Programming [1]. The Linux kernel already offers an implementation of the SRv6 End.DT6 behavior which permits IPv6 L3 VPNs over SRv6 networks. This implementation is not particularly suitable in contexts where we need to deploy IPv6 L3 VPNs among different tenants which share the same network address schemes. The underlying problem lies in the fact that the current version of DT6 (called legacy DT6 from now on) needs a complex configuration to be applied on routers which requires ad-hoc routes and routing policy rules to ensure the correct isolation of tenants. Consequently, a new implementation of DT6 has been introduced with the aim of simplifying the construction of IPv6 L3 VPN services in the multi-tenant environment using SRv6 networks. To accomplish this task, we reused the same VRF infrastructure and SRv6 core components already exploited for implementing the SRv6 End.DT4 behavior. Currently the two End.DT6 implementations coexist seamlessly and can be used depending on the context and the user preferences. So, in order to support both versions of DT6 a new attribute (vrftable) has been introduced which allows us to differentiate the implementation of the behavior to be used. A SRv6 End.DT6 legacy behavior is still instantiated using a command like the following one: $ ip -6 route add 2001:db8::1 encap seg6local action End.DT6 table 100 dev eth0 While to instantiate the SRv6 End.DT6 in VRF mode, the command is still pretty straight forward: $ ip -6 route add 2001:db8::1 encap seg6local action End.DT6 vrftable 100 dev eth0. Obviously as in the case of SRv6 End.DT4, the VRF strict_mode parameter must be set (net.vrf.strict_mode=1) and the VRF associated with table 100 must exist. Please note that the instances of SRv6 End.DT6 legacy and End.DT6 VRF mode can coexist in the same system/configuration without problems. [1] https://tools.ietf.org/html/draft-ietf-spring-srv6-network-programming Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:15 +03:00
#endif
ipv6: sr: implement additional seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END_T: regular SRH processing and forward to the next-hop looked up in the specified routing table. - SEG6_LOCAL_ACTION_END_DX2: decapsulate an L2 frame and forward it to the specified network interface. - SEG6_LOCAL_ACTION_END_DX4: decapsulate an IPv4 packet and forward it, possibly to the specified next-hop. - SEG6_LOCAL_ACTION_END_DT6: decapsulate an IPv6 packet and forward it to the next-hop looked up in the specified routing table. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 10:58:17 +03:00
.input = input_action_end_dt6,
},
seg6: add support for SRv6 End.DT46 Behavior IETF RFC 8986 [1] includes the definition of SRv6 End.DT4, End.DT6, and End.DT46 Behaviors. The current SRv6 code in the Linux kernel only implements End.DT4 and End.DT6 which can be used respectively to support IPv4-in-IPv6 and IPv6-in-IPv6 VPNs. With End.DT4 and End.DT6 it is not possible to create a single SRv6 VPN tunnel to carry both IPv4 and IPv6 traffic. The proposed End.DT46 implementation is meant to support the decapsulation of IPv4 and IPv6 traffic coming from a single SRv6 tunnel. The implementation of the SRv6 End.DT46 Behavior in the Linux kernel greatly simplifies the setup and operations of SRv6 VPNs. The SRv6 End.DT46 Behavior leverages the infrastructure of SRv6 End.DT{4,6} Behaviors implemented so far, because it makes use of a VRF device in order to force the routing lookup into the associated routing table. To make the End.DT46 work properly, it must be guaranteed that the routing table used for routing lookup operations is bound to one and only one VRF during the tunnel creation. Such constraint has to be enforced by enabling the VRF strict_mode sysctl parameter, i.e.: $ sysctl -wq net.vrf.strict_mode=1 Note that the same approach is used for the SRv6 End.DT4 Behavior and for the End.DT6 Behavior in VRF mode. The command used to instantiate an SRv6 End.DT46 Behavior is straightforward, i.e.: $ ip -6 route add 2001:db8::1 encap seg6local action End.DT46 vrftable 100 dev vrf100. [1] https://www.rfc-editor.org/rfc/rfc8986.html#name-enddt46-decapsulation-and-s ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Performance and impact of SRv6 End.DT46 Behavior on the SRv6 Networking ======================================================================= This patch aims to add the SRv6 End.DT46 Behavior with minimal impact on the performance of SRv6 End.DT4 and End.DT6 Behaviors. In order to verify this, we tested the performance of the newly introduced SRv6 End.DT46 Behavior and compared it with the performance of SRv6 End.DT{4,6} Behaviors, considering both the patched kernel and the kernel before applying the End.DT46 patch (referred to as vanilla kernel). In details, the following decapsulation scenarios were considered: 1.a) IPv6 traffic in SRv6 End.DT46 Behavior on patched kernel; 1.b) IPv4 traffic in SRv6 End.DT46 Behavior on patched kernel; 2.a) SRv6 End.DT6 Behavior (VRF mode) on patched kernel; 2.b) SRv6 End.DT4 Behavior on patched kernel; 3.a) SRv6 End.DT6 Behavior (VRF mode) on vanilla kernel (without the End.DT46 patch); 3.b) SRv6 End.DT4 Behavior on vanilla kernel (without the End.DT46 patch). All tests were performed on a testbed deployed on the CloudLab [2] facilities. We considered IPv{4,6} traffic handled by a single core (at 2.4 GHz on a Xeon(R) CPU E5-2630 v3) on kernel 5.13-rc1 using packets of size ~ 100 bytes. Scenario (1.a): average 684.70 kpps; std. dev. 0.7 kpps; Scenario (1.b): average 711.69 kpps; std. dev. 1.2 kpps; Scenario (2.a): average 690.70 kpps; std. dev. 1.2 kpps; Scenario (2.b): average 722.22 kpps; std. dev. 1.7 kpps; Scenario (3.a): average 690.02 kpps; std. dev. 2.6 kpps; Scenario (3.b): average 721.91 kpps; std. dev. 1.2 kpps; Considering the results for the patched kernel (1.a, 1.b, 2.a, 2.b) we observe that the performance degradation incurred in using End.DT46 rather than End.DT6 and End.DT4 respectively for IPv6 and IPv4 traffic is minimal, around 0.9% and 1.5%. Such very minimal performance degradation is the price to be paid if one prefers to use a single tunnel capable of handling both types of traffic (IPv4 and IPv6). Comparing the results for End.DT4 and End.DT6 under the patched and the vanilla kernel (2.a, 2.b, 3.a, 3.b) we observe that the introduction of the End.DT46 patch has no impact on the performance of End.DT4 and End.DT6. [2] https://www.cloudlab.us Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-17 20:16:44 +03:00
{
.action = SEG6_LOCAL_ACTION_END_DT46,
.attrs = SEG6_F_ATTR(SEG6_LOCAL_VRFTABLE),
.optattrs = SEG6_F_LOCAL_COUNTERS,
#ifdef CONFIG_NET_L3_MASTER_DEV
.input = input_action_end_dt46,
.slwt_ops = {
.build_state = seg6_end_dt46_build,
},
#endif
},
ipv6: sr: implement several seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END: regular SRH processing. The DA of the packet is updated to the next segment and forwarded accordingly. - SEG6_LOCAL_ACTION_END_X: same as above, except that the packet is forwarded to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_DX6: decapsulate the packet and forward to inner IPv6 packet to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_B6: insert the specified SRH directly after the IPv6 header of the packet. - SEG6_LOCAL_ACTION_END_B6_ENCAP: encapsulate the packet within an outer IPv6 header, containing the specified SRH. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:39:48 +03:00
{
.action = SEG6_LOCAL_ACTION_END_B6,
seg6: fool-proof the processing of SRv6 behavior attributes The set of required attributes for a given SRv6 behavior is identified using a bitmap stored in an unsigned long, since the initial design of SRv6 networking in Linux. Recently the same approach has been used for identifying the optional attributes. However, the number of attributes supported by SRv6 behaviors depends on the size of the unsigned long type which changes with the architecture. Indeed, on a 64-bit architecture, an SRv6 behavior can support up to 64 attributes while on a 32-bit architecture it can support at most 32 attributes. To fool-proof the processing of SRv6 behaviors we verify, at compile time, that the set of all supported SRv6 attributes can be encoded into a bitmap stored in an unsigned long. Otherwise, kernel build fails forcing developers to reconsider adding a new attribute or extend the total number of supported attributes by the SRv6 behaviors. Moreover, we replace all patterns (1 << i) with the macro SEG6_F_ATTR(i) in order to address potential overflow issues caused by 32-bit signed arithmetic. Thanks to Colin Ian King for catching the overflow problem, providing a solution and inspiring this patch. Thanks to Jakub Kicinski for his useful suggestions during the design of this patch. v2: - remove the SEG6_LOCAL_MAX_SUPP which is not strictly needed: it can be derived from the unsigned long type. Thanks to David Ahern for pointing it out. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/r/20210206170934.5982-1-andrea.mayer@uniroma2.it Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-02-06 20:09:34 +03:00
.attrs = SEG6_F_ATTR(SEG6_LOCAL_SRH),
seg6: add counters support for SRv6 Behaviors This patch provides counters for SRv6 Behaviors as defined in [1], section 6. For each SRv6 Behavior instance, counters defined in [1] are: - the total number of packets that have been correctly processed; - the total amount of traffic in bytes of all packets that have been correctly processed; In addition, this patch introduces a new counter that counts the number of packets that have NOT been properly processed (i.e. errors) by an SRv6 Behavior instance. Counters are not only interesting for network monitoring purposes (i.e. counting the number of packets processed by a given behavior) but they also provide a simple tool for checking whether a behavior instance is working as we expect or not. Counters can be useful for troubleshooting misconfigured SRv6 networks. Indeed, an SRv6 Behavior can silently drop packets for very different reasons (i.e. wrong SID configuration, interfaces set with SID addresses, etc) without any notification/message to the user. Due to the nature of SRv6 networks, diagnostic tools such as ping and traceroute may be ineffective: paths used for reaching a given router can be totally different from the ones followed by probe packets. In addition, paths are often asymmetrical and this makes it even more difficult to keep up with the journey of the packets and to understand which behaviors are actually processing our traffic. When counters are enabled on an SRv6 Behavior instance, it is possible to verify if packets are actually processed by such behavior and what is the outcome of the processing. Therefore, the counters for SRv6 Behaviors offer an non-invasive observability point which can be leveraged for both traffic monitoring and troubleshooting purposes. [1] https://www.rfc-editor.org/rfc/rfc8986.html#name-counters Troubleshooting using SRv6 Behavior counters -------------------------------------------- Let's make a brief example to see how helpful counters can be for SRv6 networks. Let's consider a node where an SRv6 End Behavior receives an SRv6 packet whose Segment Left (SL) is equal to 0. In this case, the End Behavior (which accepts only packets with SL >= 1) discards the packet and increases the error counter. This information can be leveraged by the network operator for troubleshooting. Indeed, the error counter is telling the user that the packet: (i) arrived at the node; (ii) the packet has been taken into account by the SRv6 End behavior; (iii) but an error has occurred during the processing. The error (iii) could be caused by different reasons, such as wrong route settings on the node or due to an invalid SID List carried by the SRv6 packet. Anyway, the error counter is used to exclude that the packet did not arrive at the node or it has not been processed by the behavior at all. Turning on/off counters for SRv6 Behaviors ------------------------------------------ Each SRv6 Behavior instance can be configured, at the time of its creation, to make use of counters. This is done through iproute2 which allows the user to create an SRv6 Behavior instance specifying the optional "count" attribute as shown in the following example: $ ip -6 route add 2001:db8::1 encap seg6local action End count dev eth0 per-behavior counters can be shown by adding "-s" to the iproute2 command line, i.e.: $ ip -s -6 route show 2001:db8::1 2001:db8::1 encap seg6local action End packets 0 bytes 0 errors 0 dev eth0 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Impact of counters for SRv6 Behaviors on performance ==================================================== To determine the performance impact due to the introduction of counters in the SRv6 Behavior subsystem, we have carried out extensive tests. We chose to test the throughput achieved by the SRv6 End.DX2 Behavior because, among all the other behaviors implemented so far, it reaches the highest throughput which is around 1.5 Mpps (per core at 2.4 GHz on a Xeon(R) CPU E5-2630 v3) on kernel 5.12-rc2 using packets of size ~ 100 bytes. Three different tests were conducted in order to evaluate the overall throughput of the SRv6 End.DX2 Behavior in the following scenarios: 1) vanilla kernel (without the SRv6 Behavior counters patch) and a single instance of an SRv6 End.DX2 Behavior; 2) patched kernel with SRv6 Behavior counters and a single instance of an SRv6 End.DX2 Behavior with counters turned off; 3) patched kernel with SRv6 Behavior counters and a single instance of SRv6 End.DX2 Behavior with counters turned on. All tests were performed on a testbed deployed on the CloudLab facilities [2], a flexible infrastructure dedicated to scientific research on the future of Cloud Computing. Results of tests are shown in the following table: Scenario (1): average 1504764,81 pps (~1504,76 kpps); std. dev 3956,82 pps Scenario (2): average 1501469,78 pps (~1501,47 kpps); std. dev 2979,85 pps Scenario (3): average 1501315,13 pps (~1501,32 kpps); std. dev 2956,00 pps As can be observed, throughputs achieved in scenarios (2),(3) did not suffer any observable degradation compared to scenario (1). Thanks to Jakub Kicinski and David Ahern for their valuable suggestions and comments provided during the discussion of the proposed RFCs. [2] https://www.cloudlab.us Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-04-27 18:44:04 +03:00
.optattrs = SEG6_F_LOCAL_COUNTERS,
ipv6: sr: implement several seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END: regular SRH processing. The DA of the packet is updated to the next segment and forwarded accordingly. - SEG6_LOCAL_ACTION_END_X: same as above, except that the packet is forwarded to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_DX6: decapsulate the packet and forward to inner IPv6 packet to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_B6: insert the specified SRH directly after the IPv6 header of the packet. - SEG6_LOCAL_ACTION_END_B6_ENCAP: encapsulate the packet within an outer IPv6 header, containing the specified SRH. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:39:48 +03:00
.input = input_action_end_b6,
},
{
.action = SEG6_LOCAL_ACTION_END_B6_ENCAP,
seg6: fool-proof the processing of SRv6 behavior attributes The set of required attributes for a given SRv6 behavior is identified using a bitmap stored in an unsigned long, since the initial design of SRv6 networking in Linux. Recently the same approach has been used for identifying the optional attributes. However, the number of attributes supported by SRv6 behaviors depends on the size of the unsigned long type which changes with the architecture. Indeed, on a 64-bit architecture, an SRv6 behavior can support up to 64 attributes while on a 32-bit architecture it can support at most 32 attributes. To fool-proof the processing of SRv6 behaviors we verify, at compile time, that the set of all supported SRv6 attributes can be encoded into a bitmap stored in an unsigned long. Otherwise, kernel build fails forcing developers to reconsider adding a new attribute or extend the total number of supported attributes by the SRv6 behaviors. Moreover, we replace all patterns (1 << i) with the macro SEG6_F_ATTR(i) in order to address potential overflow issues caused by 32-bit signed arithmetic. Thanks to Colin Ian King for catching the overflow problem, providing a solution and inspiring this patch. Thanks to Jakub Kicinski for his useful suggestions during the design of this patch. v2: - remove the SEG6_LOCAL_MAX_SUPP which is not strictly needed: it can be derived from the unsigned long type. Thanks to David Ahern for pointing it out. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/r/20210206170934.5982-1-andrea.mayer@uniroma2.it Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-02-06 20:09:34 +03:00
.attrs = SEG6_F_ATTR(SEG6_LOCAL_SRH),
seg6: add counters support for SRv6 Behaviors This patch provides counters for SRv6 Behaviors as defined in [1], section 6. For each SRv6 Behavior instance, counters defined in [1] are: - the total number of packets that have been correctly processed; - the total amount of traffic in bytes of all packets that have been correctly processed; In addition, this patch introduces a new counter that counts the number of packets that have NOT been properly processed (i.e. errors) by an SRv6 Behavior instance. Counters are not only interesting for network monitoring purposes (i.e. counting the number of packets processed by a given behavior) but they also provide a simple tool for checking whether a behavior instance is working as we expect or not. Counters can be useful for troubleshooting misconfigured SRv6 networks. Indeed, an SRv6 Behavior can silently drop packets for very different reasons (i.e. wrong SID configuration, interfaces set with SID addresses, etc) without any notification/message to the user. Due to the nature of SRv6 networks, diagnostic tools such as ping and traceroute may be ineffective: paths used for reaching a given router can be totally different from the ones followed by probe packets. In addition, paths are often asymmetrical and this makes it even more difficult to keep up with the journey of the packets and to understand which behaviors are actually processing our traffic. When counters are enabled on an SRv6 Behavior instance, it is possible to verify if packets are actually processed by such behavior and what is the outcome of the processing. Therefore, the counters for SRv6 Behaviors offer an non-invasive observability point which can be leveraged for both traffic monitoring and troubleshooting purposes. [1] https://www.rfc-editor.org/rfc/rfc8986.html#name-counters Troubleshooting using SRv6 Behavior counters -------------------------------------------- Let's make a brief example to see how helpful counters can be for SRv6 networks. Let's consider a node where an SRv6 End Behavior receives an SRv6 packet whose Segment Left (SL) is equal to 0. In this case, the End Behavior (which accepts only packets with SL >= 1) discards the packet and increases the error counter. This information can be leveraged by the network operator for troubleshooting. Indeed, the error counter is telling the user that the packet: (i) arrived at the node; (ii) the packet has been taken into account by the SRv6 End behavior; (iii) but an error has occurred during the processing. The error (iii) could be caused by different reasons, such as wrong route settings on the node or due to an invalid SID List carried by the SRv6 packet. Anyway, the error counter is used to exclude that the packet did not arrive at the node or it has not been processed by the behavior at all. Turning on/off counters for SRv6 Behaviors ------------------------------------------ Each SRv6 Behavior instance can be configured, at the time of its creation, to make use of counters. This is done through iproute2 which allows the user to create an SRv6 Behavior instance specifying the optional "count" attribute as shown in the following example: $ ip -6 route add 2001:db8::1 encap seg6local action End count dev eth0 per-behavior counters can be shown by adding "-s" to the iproute2 command line, i.e.: $ ip -s -6 route show 2001:db8::1 2001:db8::1 encap seg6local action End packets 0 bytes 0 errors 0 dev eth0 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Impact of counters for SRv6 Behaviors on performance ==================================================== To determine the performance impact due to the introduction of counters in the SRv6 Behavior subsystem, we have carried out extensive tests. We chose to test the throughput achieved by the SRv6 End.DX2 Behavior because, among all the other behaviors implemented so far, it reaches the highest throughput which is around 1.5 Mpps (per core at 2.4 GHz on a Xeon(R) CPU E5-2630 v3) on kernel 5.12-rc2 using packets of size ~ 100 bytes. Three different tests were conducted in order to evaluate the overall throughput of the SRv6 End.DX2 Behavior in the following scenarios: 1) vanilla kernel (without the SRv6 Behavior counters patch) and a single instance of an SRv6 End.DX2 Behavior; 2) patched kernel with SRv6 Behavior counters and a single instance of an SRv6 End.DX2 Behavior with counters turned off; 3) patched kernel with SRv6 Behavior counters and a single instance of SRv6 End.DX2 Behavior with counters turned on. All tests were performed on a testbed deployed on the CloudLab facilities [2], a flexible infrastructure dedicated to scientific research on the future of Cloud Computing. Results of tests are shown in the following table: Scenario (1): average 1504764,81 pps (~1504,76 kpps); std. dev 3956,82 pps Scenario (2): average 1501469,78 pps (~1501,47 kpps); std. dev 2979,85 pps Scenario (3): average 1501315,13 pps (~1501,32 kpps); std. dev 2956,00 pps As can be observed, throughputs achieved in scenarios (2),(3) did not suffer any observable degradation compared to scenario (1). Thanks to Jakub Kicinski and David Ahern for their valuable suggestions and comments provided during the discussion of the proposed RFCs. [2] https://www.cloudlab.us Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-04-27 18:44:04 +03:00
.optattrs = SEG6_F_LOCAL_COUNTERS,
ipv6: sr: implement several seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END: regular SRH processing. The DA of the packet is updated to the next segment and forwarded accordingly. - SEG6_LOCAL_ACTION_END_X: same as above, except that the packet is forwarded to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_DX6: decapsulate the packet and forward to inner IPv6 packet to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_B6: insert the specified SRH directly after the IPv6 header of the packet. - SEG6_LOCAL_ACTION_END_B6_ENCAP: encapsulate the packet within an outer IPv6 header, containing the specified SRH. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:39:48 +03:00
.input = input_action_end_b6_encap,
.static_headroom = sizeof(struct ipv6hdr),
ipv6: sr: Add seg6local action End.BPF This patch adds the End.BPF action to the LWT seg6local infrastructure. This action works like any other seg6local End action, meaning that an IPv6 header with SRH is needed, whose DA has to be equal to the SID of the action. It will also advance the SRH to the next segment, the BPF program does not have to take care of this. Since the BPF program may not be a source of instability in the kernel, it is important to ensure that the integrity of the packet is maintained before yielding it back to the IPv6 layer. The hook hence keeps track if the SRH has been altered through the helpers, and re-validates its content if needed with seg6_validate_srh. The state kept for validation is stored in a per-CPU buffer. The BPF program is not allowed to directly write into the packet, and only some fields of the SRH can be altered through the helper bpf_lwt_seg6_store_bytes. Performances profiling has shown that the SRH re-validation does not induce a significant overhead. If the altered SRH is deemed as invalid, the packet is dropped. This validation is also done before executing any action through bpf_lwt_seg6_action, and will not be performed again if the SRH is not modified after calling the action. The BPF program may return 3 types of return codes: - BPF_OK: the End.BPF action will look up the next destination through seg6_lookup_nexthop. - BPF_REDIRECT: if an action has been executed through the bpf_lwt_seg6_action helper, the BPF program should return this value, as the skb's destination is already set and the default lookup should not be performed. - BPF_DROP : the packet will be dropped. Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-20 16:58:16 +03:00
},
{
.action = SEG6_LOCAL_ACTION_END_BPF,
seg6: fool-proof the processing of SRv6 behavior attributes The set of required attributes for a given SRv6 behavior is identified using a bitmap stored in an unsigned long, since the initial design of SRv6 networking in Linux. Recently the same approach has been used for identifying the optional attributes. However, the number of attributes supported by SRv6 behaviors depends on the size of the unsigned long type which changes with the architecture. Indeed, on a 64-bit architecture, an SRv6 behavior can support up to 64 attributes while on a 32-bit architecture it can support at most 32 attributes. To fool-proof the processing of SRv6 behaviors we verify, at compile time, that the set of all supported SRv6 attributes can be encoded into a bitmap stored in an unsigned long. Otherwise, kernel build fails forcing developers to reconsider adding a new attribute or extend the total number of supported attributes by the SRv6 behaviors. Moreover, we replace all patterns (1 << i) with the macro SEG6_F_ATTR(i) in order to address potential overflow issues caused by 32-bit signed arithmetic. Thanks to Colin Ian King for catching the overflow problem, providing a solution and inspiring this patch. Thanks to Jakub Kicinski for his useful suggestions during the design of this patch. v2: - remove the SEG6_LOCAL_MAX_SUPP which is not strictly needed: it can be derived from the unsigned long type. Thanks to David Ahern for pointing it out. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/r/20210206170934.5982-1-andrea.mayer@uniroma2.it Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-02-06 20:09:34 +03:00
.attrs = SEG6_F_ATTR(SEG6_LOCAL_BPF),
seg6: add counters support for SRv6 Behaviors This patch provides counters for SRv6 Behaviors as defined in [1], section 6. For each SRv6 Behavior instance, counters defined in [1] are: - the total number of packets that have been correctly processed; - the total amount of traffic in bytes of all packets that have been correctly processed; In addition, this patch introduces a new counter that counts the number of packets that have NOT been properly processed (i.e. errors) by an SRv6 Behavior instance. Counters are not only interesting for network monitoring purposes (i.e. counting the number of packets processed by a given behavior) but they also provide a simple tool for checking whether a behavior instance is working as we expect or not. Counters can be useful for troubleshooting misconfigured SRv6 networks. Indeed, an SRv6 Behavior can silently drop packets for very different reasons (i.e. wrong SID configuration, interfaces set with SID addresses, etc) without any notification/message to the user. Due to the nature of SRv6 networks, diagnostic tools such as ping and traceroute may be ineffective: paths used for reaching a given router can be totally different from the ones followed by probe packets. In addition, paths are often asymmetrical and this makes it even more difficult to keep up with the journey of the packets and to understand which behaviors are actually processing our traffic. When counters are enabled on an SRv6 Behavior instance, it is possible to verify if packets are actually processed by such behavior and what is the outcome of the processing. Therefore, the counters for SRv6 Behaviors offer an non-invasive observability point which can be leveraged for both traffic monitoring and troubleshooting purposes. [1] https://www.rfc-editor.org/rfc/rfc8986.html#name-counters Troubleshooting using SRv6 Behavior counters -------------------------------------------- Let's make a brief example to see how helpful counters can be for SRv6 networks. Let's consider a node where an SRv6 End Behavior receives an SRv6 packet whose Segment Left (SL) is equal to 0. In this case, the End Behavior (which accepts only packets with SL >= 1) discards the packet and increases the error counter. This information can be leveraged by the network operator for troubleshooting. Indeed, the error counter is telling the user that the packet: (i) arrived at the node; (ii) the packet has been taken into account by the SRv6 End behavior; (iii) but an error has occurred during the processing. The error (iii) could be caused by different reasons, such as wrong route settings on the node or due to an invalid SID List carried by the SRv6 packet. Anyway, the error counter is used to exclude that the packet did not arrive at the node or it has not been processed by the behavior at all. Turning on/off counters for SRv6 Behaviors ------------------------------------------ Each SRv6 Behavior instance can be configured, at the time of its creation, to make use of counters. This is done through iproute2 which allows the user to create an SRv6 Behavior instance specifying the optional "count" attribute as shown in the following example: $ ip -6 route add 2001:db8::1 encap seg6local action End count dev eth0 per-behavior counters can be shown by adding "-s" to the iproute2 command line, i.e.: $ ip -s -6 route show 2001:db8::1 2001:db8::1 encap seg6local action End packets 0 bytes 0 errors 0 dev eth0 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Impact of counters for SRv6 Behaviors on performance ==================================================== To determine the performance impact due to the introduction of counters in the SRv6 Behavior subsystem, we have carried out extensive tests. We chose to test the throughput achieved by the SRv6 End.DX2 Behavior because, among all the other behaviors implemented so far, it reaches the highest throughput which is around 1.5 Mpps (per core at 2.4 GHz on a Xeon(R) CPU E5-2630 v3) on kernel 5.12-rc2 using packets of size ~ 100 bytes. Three different tests were conducted in order to evaluate the overall throughput of the SRv6 End.DX2 Behavior in the following scenarios: 1) vanilla kernel (without the SRv6 Behavior counters patch) and a single instance of an SRv6 End.DX2 Behavior; 2) patched kernel with SRv6 Behavior counters and a single instance of an SRv6 End.DX2 Behavior with counters turned off; 3) patched kernel with SRv6 Behavior counters and a single instance of SRv6 End.DX2 Behavior with counters turned on. All tests were performed on a testbed deployed on the CloudLab facilities [2], a flexible infrastructure dedicated to scientific research on the future of Cloud Computing. Results of tests are shown in the following table: Scenario (1): average 1504764,81 pps (~1504,76 kpps); std. dev 3956,82 pps Scenario (2): average 1501469,78 pps (~1501,47 kpps); std. dev 2979,85 pps Scenario (3): average 1501315,13 pps (~1501,32 kpps); std. dev 2956,00 pps As can be observed, throughputs achieved in scenarios (2),(3) did not suffer any observable degradation compared to scenario (1). Thanks to Jakub Kicinski and David Ahern for their valuable suggestions and comments provided during the discussion of the proposed RFCs. [2] https://www.cloudlab.us Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-04-27 18:44:04 +03:00
.optattrs = SEG6_F_LOCAL_COUNTERS,
ipv6: sr: Add seg6local action End.BPF This patch adds the End.BPF action to the LWT seg6local infrastructure. This action works like any other seg6local End action, meaning that an IPv6 header with SRH is needed, whose DA has to be equal to the SID of the action. It will also advance the SRH to the next segment, the BPF program does not have to take care of this. Since the BPF program may not be a source of instability in the kernel, it is important to ensure that the integrity of the packet is maintained before yielding it back to the IPv6 layer. The hook hence keeps track if the SRH has been altered through the helpers, and re-validates its content if needed with seg6_validate_srh. The state kept for validation is stored in a per-CPU buffer. The BPF program is not allowed to directly write into the packet, and only some fields of the SRH can be altered through the helper bpf_lwt_seg6_store_bytes. Performances profiling has shown that the SRH re-validation does not induce a significant overhead. If the altered SRH is deemed as invalid, the packet is dropped. This validation is also done before executing any action through bpf_lwt_seg6_action, and will not be performed again if the SRH is not modified after calling the action. The BPF program may return 3 types of return codes: - BPF_OK: the End.BPF action will look up the next destination through seg6_lookup_nexthop. - BPF_REDIRECT: if an action has been executed through the bpf_lwt_seg6_action helper, the BPF program should return this value, as the skb's destination is already set and the default lookup should not be performed. - BPF_DROP : the packet will be dropped. Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-20 16:58:16 +03:00
.input = input_action_end_bpf,
},
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:26 +03:00
};
static struct seg6_action_desc *__get_action_desc(int action)
{
struct seg6_action_desc *desc;
int i, count;
ipv6: use ARRAY_SIZE for array sizing calculation on array seg6_action_table Use the ARRAY_SIZE macro on array seg6_action_table to determine size of the array. Improvement suggested by coccinelle. Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-08 02:50:26 +03:00
count = ARRAY_SIZE(seg6_action_table);
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:26 +03:00
for (i = 0; i < count; i++) {
desc = &seg6_action_table[i];
if (desc->action == action)
return desc;
}
return NULL;
}
seg6: add counters support for SRv6 Behaviors This patch provides counters for SRv6 Behaviors as defined in [1], section 6. For each SRv6 Behavior instance, counters defined in [1] are: - the total number of packets that have been correctly processed; - the total amount of traffic in bytes of all packets that have been correctly processed; In addition, this patch introduces a new counter that counts the number of packets that have NOT been properly processed (i.e. errors) by an SRv6 Behavior instance. Counters are not only interesting for network monitoring purposes (i.e. counting the number of packets processed by a given behavior) but they also provide a simple tool for checking whether a behavior instance is working as we expect or not. Counters can be useful for troubleshooting misconfigured SRv6 networks. Indeed, an SRv6 Behavior can silently drop packets for very different reasons (i.e. wrong SID configuration, interfaces set with SID addresses, etc) without any notification/message to the user. Due to the nature of SRv6 networks, diagnostic tools such as ping and traceroute may be ineffective: paths used for reaching a given router can be totally different from the ones followed by probe packets. In addition, paths are often asymmetrical and this makes it even more difficult to keep up with the journey of the packets and to understand which behaviors are actually processing our traffic. When counters are enabled on an SRv6 Behavior instance, it is possible to verify if packets are actually processed by such behavior and what is the outcome of the processing. Therefore, the counters for SRv6 Behaviors offer an non-invasive observability point which can be leveraged for both traffic monitoring and troubleshooting purposes. [1] https://www.rfc-editor.org/rfc/rfc8986.html#name-counters Troubleshooting using SRv6 Behavior counters -------------------------------------------- Let's make a brief example to see how helpful counters can be for SRv6 networks. Let's consider a node where an SRv6 End Behavior receives an SRv6 packet whose Segment Left (SL) is equal to 0. In this case, the End Behavior (which accepts only packets with SL >= 1) discards the packet and increases the error counter. This information can be leveraged by the network operator for troubleshooting. Indeed, the error counter is telling the user that the packet: (i) arrived at the node; (ii) the packet has been taken into account by the SRv6 End behavior; (iii) but an error has occurred during the processing. The error (iii) could be caused by different reasons, such as wrong route settings on the node or due to an invalid SID List carried by the SRv6 packet. Anyway, the error counter is used to exclude that the packet did not arrive at the node or it has not been processed by the behavior at all. Turning on/off counters for SRv6 Behaviors ------------------------------------------ Each SRv6 Behavior instance can be configured, at the time of its creation, to make use of counters. This is done through iproute2 which allows the user to create an SRv6 Behavior instance specifying the optional "count" attribute as shown in the following example: $ ip -6 route add 2001:db8::1 encap seg6local action End count dev eth0 per-behavior counters can be shown by adding "-s" to the iproute2 command line, i.e.: $ ip -s -6 route show 2001:db8::1 2001:db8::1 encap seg6local action End packets 0 bytes 0 errors 0 dev eth0 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Impact of counters for SRv6 Behaviors on performance ==================================================== To determine the performance impact due to the introduction of counters in the SRv6 Behavior subsystem, we have carried out extensive tests. We chose to test the throughput achieved by the SRv6 End.DX2 Behavior because, among all the other behaviors implemented so far, it reaches the highest throughput which is around 1.5 Mpps (per core at 2.4 GHz on a Xeon(R) CPU E5-2630 v3) on kernel 5.12-rc2 using packets of size ~ 100 bytes. Three different tests were conducted in order to evaluate the overall throughput of the SRv6 End.DX2 Behavior in the following scenarios: 1) vanilla kernel (without the SRv6 Behavior counters patch) and a single instance of an SRv6 End.DX2 Behavior; 2) patched kernel with SRv6 Behavior counters and a single instance of an SRv6 End.DX2 Behavior with counters turned off; 3) patched kernel with SRv6 Behavior counters and a single instance of SRv6 End.DX2 Behavior with counters turned on. All tests were performed on a testbed deployed on the CloudLab facilities [2], a flexible infrastructure dedicated to scientific research on the future of Cloud Computing. Results of tests are shown in the following table: Scenario (1): average 1504764,81 pps (~1504,76 kpps); std. dev 3956,82 pps Scenario (2): average 1501469,78 pps (~1501,47 kpps); std. dev 2979,85 pps Scenario (3): average 1501315,13 pps (~1501,32 kpps); std. dev 2956,00 pps As can be observed, throughputs achieved in scenarios (2),(3) did not suffer any observable degradation compared to scenario (1). Thanks to Jakub Kicinski and David Ahern for their valuable suggestions and comments provided during the discussion of the proposed RFCs. [2] https://www.cloudlab.us Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-04-27 18:44:04 +03:00
static bool seg6_lwtunnel_counters_enabled(struct seg6_local_lwt *slwt)
{
return slwt->parsed_optattrs & SEG6_F_LOCAL_COUNTERS;
}
static void seg6_local_update_counters(struct seg6_local_lwt *slwt,
unsigned int len, int err)
{
struct pcpu_seg6_local_counters *pcounters;
pcounters = this_cpu_ptr(slwt->pcpu_counters);
u64_stats_update_begin(&pcounters->syncp);
if (likely(!err)) {
u64_stats_inc(&pcounters->packets);
u64_stats_add(&pcounters->bytes, len);
} else {
u64_stats_inc(&pcounters->errors);
}
u64_stats_update_end(&pcounters->syncp);
}
netfilter: add netfilter hooks to SRv6 data plane This patch introduces netfilter hooks for solving the problem that conntrack couldn't record both inner flows and outer flows. This patch also introduces a new sysctl toggle for enabling lightweight tunnel netfilter hooks. Signed-off-by: Ryoga Saito <contact@proelbtn.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-08-17 11:39:37 +03:00
static int seg6_local_input_core(struct net *net, struct sock *sk,
struct sk_buff *skb)
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:26 +03:00
{
struct dst_entry *orig_dst = skb_dst(skb);
struct seg6_action_desc *desc;
struct seg6_local_lwt *slwt;
seg6: add counters support for SRv6 Behaviors This patch provides counters for SRv6 Behaviors as defined in [1], section 6. For each SRv6 Behavior instance, counters defined in [1] are: - the total number of packets that have been correctly processed; - the total amount of traffic in bytes of all packets that have been correctly processed; In addition, this patch introduces a new counter that counts the number of packets that have NOT been properly processed (i.e. errors) by an SRv6 Behavior instance. Counters are not only interesting for network monitoring purposes (i.e. counting the number of packets processed by a given behavior) but they also provide a simple tool for checking whether a behavior instance is working as we expect or not. Counters can be useful for troubleshooting misconfigured SRv6 networks. Indeed, an SRv6 Behavior can silently drop packets for very different reasons (i.e. wrong SID configuration, interfaces set with SID addresses, etc) without any notification/message to the user. Due to the nature of SRv6 networks, diagnostic tools such as ping and traceroute may be ineffective: paths used for reaching a given router can be totally different from the ones followed by probe packets. In addition, paths are often asymmetrical and this makes it even more difficult to keep up with the journey of the packets and to understand which behaviors are actually processing our traffic. When counters are enabled on an SRv6 Behavior instance, it is possible to verify if packets are actually processed by such behavior and what is the outcome of the processing. Therefore, the counters for SRv6 Behaviors offer an non-invasive observability point which can be leveraged for both traffic monitoring and troubleshooting purposes. [1] https://www.rfc-editor.org/rfc/rfc8986.html#name-counters Troubleshooting using SRv6 Behavior counters -------------------------------------------- Let's make a brief example to see how helpful counters can be for SRv6 networks. Let's consider a node where an SRv6 End Behavior receives an SRv6 packet whose Segment Left (SL) is equal to 0. In this case, the End Behavior (which accepts only packets with SL >= 1) discards the packet and increases the error counter. This information can be leveraged by the network operator for troubleshooting. Indeed, the error counter is telling the user that the packet: (i) arrived at the node; (ii) the packet has been taken into account by the SRv6 End behavior; (iii) but an error has occurred during the processing. The error (iii) could be caused by different reasons, such as wrong route settings on the node or due to an invalid SID List carried by the SRv6 packet. Anyway, the error counter is used to exclude that the packet did not arrive at the node or it has not been processed by the behavior at all. Turning on/off counters for SRv6 Behaviors ------------------------------------------ Each SRv6 Behavior instance can be configured, at the time of its creation, to make use of counters. This is done through iproute2 which allows the user to create an SRv6 Behavior instance specifying the optional "count" attribute as shown in the following example: $ ip -6 route add 2001:db8::1 encap seg6local action End count dev eth0 per-behavior counters can be shown by adding "-s" to the iproute2 command line, i.e.: $ ip -s -6 route show 2001:db8::1 2001:db8::1 encap seg6local action End packets 0 bytes 0 errors 0 dev eth0 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Impact of counters for SRv6 Behaviors on performance ==================================================== To determine the performance impact due to the introduction of counters in the SRv6 Behavior subsystem, we have carried out extensive tests. We chose to test the throughput achieved by the SRv6 End.DX2 Behavior because, among all the other behaviors implemented so far, it reaches the highest throughput which is around 1.5 Mpps (per core at 2.4 GHz on a Xeon(R) CPU E5-2630 v3) on kernel 5.12-rc2 using packets of size ~ 100 bytes. Three different tests were conducted in order to evaluate the overall throughput of the SRv6 End.DX2 Behavior in the following scenarios: 1) vanilla kernel (without the SRv6 Behavior counters patch) and a single instance of an SRv6 End.DX2 Behavior; 2) patched kernel with SRv6 Behavior counters and a single instance of an SRv6 End.DX2 Behavior with counters turned off; 3) patched kernel with SRv6 Behavior counters and a single instance of SRv6 End.DX2 Behavior with counters turned on. All tests were performed on a testbed deployed on the CloudLab facilities [2], a flexible infrastructure dedicated to scientific research on the future of Cloud Computing. Results of tests are shown in the following table: Scenario (1): average 1504764,81 pps (~1504,76 kpps); std. dev 3956,82 pps Scenario (2): average 1501469,78 pps (~1501,47 kpps); std. dev 2979,85 pps Scenario (3): average 1501315,13 pps (~1501,32 kpps); std. dev 2956,00 pps As can be observed, throughputs achieved in scenarios (2),(3) did not suffer any observable degradation compared to scenario (1). Thanks to Jakub Kicinski and David Ahern for their valuable suggestions and comments provided during the discussion of the proposed RFCs. [2] https://www.cloudlab.us Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-04-27 18:44:04 +03:00
unsigned int len = skb->len;
int rc;
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:26 +03:00
slwt = seg6_local_lwtunnel(orig_dst->lwtstate);
desc = slwt->desc;
seg6: add counters support for SRv6 Behaviors This patch provides counters for SRv6 Behaviors as defined in [1], section 6. For each SRv6 Behavior instance, counters defined in [1] are: - the total number of packets that have been correctly processed; - the total amount of traffic in bytes of all packets that have been correctly processed; In addition, this patch introduces a new counter that counts the number of packets that have NOT been properly processed (i.e. errors) by an SRv6 Behavior instance. Counters are not only interesting for network monitoring purposes (i.e. counting the number of packets processed by a given behavior) but they also provide a simple tool for checking whether a behavior instance is working as we expect or not. Counters can be useful for troubleshooting misconfigured SRv6 networks. Indeed, an SRv6 Behavior can silently drop packets for very different reasons (i.e. wrong SID configuration, interfaces set with SID addresses, etc) without any notification/message to the user. Due to the nature of SRv6 networks, diagnostic tools such as ping and traceroute may be ineffective: paths used for reaching a given router can be totally different from the ones followed by probe packets. In addition, paths are often asymmetrical and this makes it even more difficult to keep up with the journey of the packets and to understand which behaviors are actually processing our traffic. When counters are enabled on an SRv6 Behavior instance, it is possible to verify if packets are actually processed by such behavior and what is the outcome of the processing. Therefore, the counters for SRv6 Behaviors offer an non-invasive observability point which can be leveraged for both traffic monitoring and troubleshooting purposes. [1] https://www.rfc-editor.org/rfc/rfc8986.html#name-counters Troubleshooting using SRv6 Behavior counters -------------------------------------------- Let's make a brief example to see how helpful counters can be for SRv6 networks. Let's consider a node where an SRv6 End Behavior receives an SRv6 packet whose Segment Left (SL) is equal to 0. In this case, the End Behavior (which accepts only packets with SL >= 1) discards the packet and increases the error counter. This information can be leveraged by the network operator for troubleshooting. Indeed, the error counter is telling the user that the packet: (i) arrived at the node; (ii) the packet has been taken into account by the SRv6 End behavior; (iii) but an error has occurred during the processing. The error (iii) could be caused by different reasons, such as wrong route settings on the node or due to an invalid SID List carried by the SRv6 packet. Anyway, the error counter is used to exclude that the packet did not arrive at the node or it has not been processed by the behavior at all. Turning on/off counters for SRv6 Behaviors ------------------------------------------ Each SRv6 Behavior instance can be configured, at the time of its creation, to make use of counters. This is done through iproute2 which allows the user to create an SRv6 Behavior instance specifying the optional "count" attribute as shown in the following example: $ ip -6 route add 2001:db8::1 encap seg6local action End count dev eth0 per-behavior counters can be shown by adding "-s" to the iproute2 command line, i.e.: $ ip -s -6 route show 2001:db8::1 2001:db8::1 encap seg6local action End packets 0 bytes 0 errors 0 dev eth0 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Impact of counters for SRv6 Behaviors on performance ==================================================== To determine the performance impact due to the introduction of counters in the SRv6 Behavior subsystem, we have carried out extensive tests. We chose to test the throughput achieved by the SRv6 End.DX2 Behavior because, among all the other behaviors implemented so far, it reaches the highest throughput which is around 1.5 Mpps (per core at 2.4 GHz on a Xeon(R) CPU E5-2630 v3) on kernel 5.12-rc2 using packets of size ~ 100 bytes. Three different tests were conducted in order to evaluate the overall throughput of the SRv6 End.DX2 Behavior in the following scenarios: 1) vanilla kernel (without the SRv6 Behavior counters patch) and a single instance of an SRv6 End.DX2 Behavior; 2) patched kernel with SRv6 Behavior counters and a single instance of an SRv6 End.DX2 Behavior with counters turned off; 3) patched kernel with SRv6 Behavior counters and a single instance of SRv6 End.DX2 Behavior with counters turned on. All tests were performed on a testbed deployed on the CloudLab facilities [2], a flexible infrastructure dedicated to scientific research on the future of Cloud Computing. Results of tests are shown in the following table: Scenario (1): average 1504764,81 pps (~1504,76 kpps); std. dev 3956,82 pps Scenario (2): average 1501469,78 pps (~1501,47 kpps); std. dev 2979,85 pps Scenario (3): average 1501315,13 pps (~1501,32 kpps); std. dev 2956,00 pps As can be observed, throughputs achieved in scenarios (2),(3) did not suffer any observable degradation compared to scenario (1). Thanks to Jakub Kicinski and David Ahern for their valuable suggestions and comments provided during the discussion of the proposed RFCs. [2] https://www.cloudlab.us Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-04-27 18:44:04 +03:00
rc = desc->input(skb, slwt);
if (!seg6_lwtunnel_counters_enabled(slwt))
return rc;
seg6_local_update_counters(slwt, len, rc);
return rc;
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:26 +03:00
}
netfilter: add netfilter hooks to SRv6 data plane This patch introduces netfilter hooks for solving the problem that conntrack couldn't record both inner flows and outer flows. This patch also introduces a new sysctl toggle for enabling lightweight tunnel netfilter hooks. Signed-off-by: Ryoga Saito <contact@proelbtn.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-08-17 11:39:37 +03:00
static int seg6_local_input(struct sk_buff *skb)
{
if (skb->protocol != htons(ETH_P_IPV6)) {
kfree_skb(skb);
return -EINVAL;
}
if (static_branch_unlikely(&nf_hooks_lwtunnel_enabled))
return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_IN,
dev_net(skb->dev), NULL, skb, skb->dev, NULL,
seg6_local_input_core);
return seg6_local_input_core(dev_net(skb->dev), NULL, skb);
}
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:26 +03:00
static const struct nla_policy seg6_local_policy[SEG6_LOCAL_MAX + 1] = {
[SEG6_LOCAL_ACTION] = { .type = NLA_U32 },
[SEG6_LOCAL_SRH] = { .type = NLA_BINARY },
[SEG6_LOCAL_TABLE] = { .type = NLA_U32 },
seg6: add support for the SRv6 End.DT4 behavior SRv6 End.DT4 is defined in the SRv6 Network Programming [1]. The SRv6 End.DT4 is used to implement IPv4 L3VPN use-cases in multi-tenants environments. It decapsulates the received packets and it performs IPv4 routing lookup in the routing table of the tenant. The SRv6 End.DT4 Linux implementation leverages a VRF device in order to force the routing lookup into the associated routing table. To make the End.DT4 work properly, it must be guaranteed that the routing table used for routing lookup operations is bound to one and only one VRF during the tunnel creation. Such constraint has to be enforced by enabling the VRF strict_mode sysctl parameter, i.e: $ sysctl -wq net.vrf.strict_mode=1. At JANOG44, LINE corporation presented their multi-tenant DC architecture using SRv6 [2]. In the slides, they reported that the Linux kernel is missing the support of SRv6 End.DT4 behavior. The SRv6 End.DT4 behavior can be instantiated using a command similar to the following: $ ip route add 2001:db8::1 encap seg6local action End.DT4 vrftable 100 dev eth0 We introduce the "vrftable" extension in iproute2 in a following patch. [1] https://tools.ietf.org/html/draft-ietf-spring-srv6-network-programming [2] https://speakerdeck.com/line_developers/line-data-center-networking-with-srv6 Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:14 +03:00
[SEG6_LOCAL_VRFTABLE] = { .type = NLA_U32 },
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:26 +03:00
[SEG6_LOCAL_NH4] = { .type = NLA_BINARY,
.len = sizeof(struct in_addr) },
[SEG6_LOCAL_NH6] = { .type = NLA_BINARY,
.len = sizeof(struct in6_addr) },
[SEG6_LOCAL_IIF] = { .type = NLA_U32 },
[SEG6_LOCAL_OIF] = { .type = NLA_U32 },
ipv6: sr: Add seg6local action End.BPF This patch adds the End.BPF action to the LWT seg6local infrastructure. This action works like any other seg6local End action, meaning that an IPv6 header with SRH is needed, whose DA has to be equal to the SID of the action. It will also advance the SRH to the next segment, the BPF program does not have to take care of this. Since the BPF program may not be a source of instability in the kernel, it is important to ensure that the integrity of the packet is maintained before yielding it back to the IPv6 layer. The hook hence keeps track if the SRH has been altered through the helpers, and re-validates its content if needed with seg6_validate_srh. The state kept for validation is stored in a per-CPU buffer. The BPF program is not allowed to directly write into the packet, and only some fields of the SRH can be altered through the helper bpf_lwt_seg6_store_bytes. Performances profiling has shown that the SRH re-validation does not induce a significant overhead. If the altered SRH is deemed as invalid, the packet is dropped. This validation is also done before executing any action through bpf_lwt_seg6_action, and will not be performed again if the SRH is not modified after calling the action. The BPF program may return 3 types of return codes: - BPF_OK: the End.BPF action will look up the next destination through seg6_lookup_nexthop. - BPF_REDIRECT: if an action has been executed through the bpf_lwt_seg6_action helper, the BPF program should return this value, as the skb's destination is already set and the default lookup should not be performed. - BPF_DROP : the packet will be dropped. Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-20 16:58:16 +03:00
[SEG6_LOCAL_BPF] = { .type = NLA_NESTED },
seg6: add counters support for SRv6 Behaviors This patch provides counters for SRv6 Behaviors as defined in [1], section 6. For each SRv6 Behavior instance, counters defined in [1] are: - the total number of packets that have been correctly processed; - the total amount of traffic in bytes of all packets that have been correctly processed; In addition, this patch introduces a new counter that counts the number of packets that have NOT been properly processed (i.e. errors) by an SRv6 Behavior instance. Counters are not only interesting for network monitoring purposes (i.e. counting the number of packets processed by a given behavior) but they also provide a simple tool for checking whether a behavior instance is working as we expect or not. Counters can be useful for troubleshooting misconfigured SRv6 networks. Indeed, an SRv6 Behavior can silently drop packets for very different reasons (i.e. wrong SID configuration, interfaces set with SID addresses, etc) without any notification/message to the user. Due to the nature of SRv6 networks, diagnostic tools such as ping and traceroute may be ineffective: paths used for reaching a given router can be totally different from the ones followed by probe packets. In addition, paths are often asymmetrical and this makes it even more difficult to keep up with the journey of the packets and to understand which behaviors are actually processing our traffic. When counters are enabled on an SRv6 Behavior instance, it is possible to verify if packets are actually processed by such behavior and what is the outcome of the processing. Therefore, the counters for SRv6 Behaviors offer an non-invasive observability point which can be leveraged for both traffic monitoring and troubleshooting purposes. [1] https://www.rfc-editor.org/rfc/rfc8986.html#name-counters Troubleshooting using SRv6 Behavior counters -------------------------------------------- Let's make a brief example to see how helpful counters can be for SRv6 networks. Let's consider a node where an SRv6 End Behavior receives an SRv6 packet whose Segment Left (SL) is equal to 0. In this case, the End Behavior (which accepts only packets with SL >= 1) discards the packet and increases the error counter. This information can be leveraged by the network operator for troubleshooting. Indeed, the error counter is telling the user that the packet: (i) arrived at the node; (ii) the packet has been taken into account by the SRv6 End behavior; (iii) but an error has occurred during the processing. The error (iii) could be caused by different reasons, such as wrong route settings on the node or due to an invalid SID List carried by the SRv6 packet. Anyway, the error counter is used to exclude that the packet did not arrive at the node or it has not been processed by the behavior at all. Turning on/off counters for SRv6 Behaviors ------------------------------------------ Each SRv6 Behavior instance can be configured, at the time of its creation, to make use of counters. This is done through iproute2 which allows the user to create an SRv6 Behavior instance specifying the optional "count" attribute as shown in the following example: $ ip -6 route add 2001:db8::1 encap seg6local action End count dev eth0 per-behavior counters can be shown by adding "-s" to the iproute2 command line, i.e.: $ ip -s -6 route show 2001:db8::1 2001:db8::1 encap seg6local action End packets 0 bytes 0 errors 0 dev eth0 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Impact of counters for SRv6 Behaviors on performance ==================================================== To determine the performance impact due to the introduction of counters in the SRv6 Behavior subsystem, we have carried out extensive tests. We chose to test the throughput achieved by the SRv6 End.DX2 Behavior because, among all the other behaviors implemented so far, it reaches the highest throughput which is around 1.5 Mpps (per core at 2.4 GHz on a Xeon(R) CPU E5-2630 v3) on kernel 5.12-rc2 using packets of size ~ 100 bytes. Three different tests were conducted in order to evaluate the overall throughput of the SRv6 End.DX2 Behavior in the following scenarios: 1) vanilla kernel (without the SRv6 Behavior counters patch) and a single instance of an SRv6 End.DX2 Behavior; 2) patched kernel with SRv6 Behavior counters and a single instance of an SRv6 End.DX2 Behavior with counters turned off; 3) patched kernel with SRv6 Behavior counters and a single instance of SRv6 End.DX2 Behavior with counters turned on. All tests were performed on a testbed deployed on the CloudLab facilities [2], a flexible infrastructure dedicated to scientific research on the future of Cloud Computing. Results of tests are shown in the following table: Scenario (1): average 1504764,81 pps (~1504,76 kpps); std. dev 3956,82 pps Scenario (2): average 1501469,78 pps (~1501,47 kpps); std. dev 2979,85 pps Scenario (3): average 1501315,13 pps (~1501,32 kpps); std. dev 2956,00 pps As can be observed, throughputs achieved in scenarios (2),(3) did not suffer any observable degradation compared to scenario (1). Thanks to Jakub Kicinski and David Ahern for their valuable suggestions and comments provided during the discussion of the proposed RFCs. [2] https://www.cloudlab.us Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-04-27 18:44:04 +03:00
[SEG6_LOCAL_COUNTERS] = { .type = NLA_NESTED },
seg6: add NEXT-C-SID support for SRv6 End behavior The NEXT-C-SID mechanism described in [1] offers the possibility of encoding several SRv6 segments within a single 128 bit SID address. Such a SID address is called a Compressed SID (C-SID) container. In this way, the length of the SID List can be drastically reduced. A SID instantiated with the NEXT-C-SID flavor considers an IPv6 address logically structured in three main blocks: i) Locator-Block; ii) Locator-Node Function; iii) Argument. C-SID container +------------------------------------------------------------------+ | Locator-Block |Loc-Node| Argument | | |Function| | +------------------------------------------------------------------+ <--------- B -----------> <- NF -> <------------- A ---------------> (i) The Locator-Block can be any IPv6 prefix available to the provider; (ii) The Locator-Node Function represents the node and the function to be triggered when a packet is received on the node; (iii) The Argument carries the remaining C-SIDs in the current C-SID container. The NEXT-C-SID mechanism relies on the "flavors" framework defined in [2]. The flavors represent additional operations that can modify or extend a subset of the existing behaviors. This patch introduces the support for flavors in SRv6 End behavior implementing the NEXT-C-SID one. An SRv6 End behavior with NEXT-C-SID flavor works as an End behavior but it is capable of processing the compressed SID List encoded in C-SID containers. An SRv6 End behavior with NEXT-C-SID flavor can be configured to support user-provided Locator-Block and Locator-Node Function lengths. In this implementation, such lengths must be evenly divisible by 8 (i.e. must be byte-aligned), otherwise the kernel informs the user about invalid values with a meaningful error code and message through netlink_ext_ack. If Locator-Block and/or Locator-Node Function lengths are not provided by the user during configuration of an SRv6 End behavior instance with NEXT-C-SID flavor, the kernel will choose their default values i.e., 32-bit Locator-Block and 16-bit Locator-Node Function. [1] - https://datatracker.ietf.org/doc/html/draft-ietf-spring-srv6-srh-compression [2] - https://datatracker.ietf.org/doc/html/rfc8986 Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-09-12 20:16:18 +03:00
[SEG6_LOCAL_FLAVORS] = { .type = NLA_NESTED },
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:26 +03:00
};
seg6: add netlink_ext_ack support in parsing SRv6 behavior attributes An SRv6 behavior instance can be set up using mandatory and/or optional attributes. In the setup phase, each supplied attribute is parsed and processed. If the parsing operation fails, the creation of the behavior instance stops and an error number/code is reported to the user. In many cases, it is challenging for the user to figure out exactly what happened by relying only on the error code. For this reason, we add the support for netlink_ext_ack in parsing SRv6 behavior attributes. In this way, when an SRv6 behavior attribute is parsed and an error occurs, the kernel can send a message to the userspace describing the error through a meaningful text message in addition to the classic error code. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-09-12 20:16:17 +03:00
static int parse_nla_srh(struct nlattr **attrs, struct seg6_local_lwt *slwt,
struct netlink_ext_ack *extack)
ipv6: sr: add rtnetlink functions for seg6local action parameters This patch adds the necessary functions to parse, fill, and compare seg6local rtnetlink attributes, for all defined action parameters. - The SRH parameter defines an SRH to be inserted or encapsulated. - The TABLE parameter defines the table to use for the route lookup of the next segment or the inner decapsulated packet. - The NH4 parameter defines the IPv4 next-hop for an inner decapsulated IPv4 packet. - The NH6 parameter defines the IPv6 next-hop for the next segment or for an inner decapsulated IPv6 packet - The IIF parameter defines an ingress interface index. - The OIF parameter defines an egress interface index. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:27 +03:00
{
struct ipv6_sr_hdr *srh;
int len;
srh = nla_data(attrs[SEG6_LOCAL_SRH]);
len = nla_len(attrs[SEG6_LOCAL_SRH]);
/* SRH must contain at least one segment */
if (len < sizeof(*srh) + sizeof(struct in6_addr))
return -EINVAL;
seg6: fix seg6_validate_srh() to avoid slab-out-of-bounds The seg6_validate_srh() is used to validate SRH for three cases: case1: SRH of data-plane SRv6 packets to be processed by the Linux kernel. Case2: SRH of the netlink message received from user-space (iproute2) Case3: SRH injected into packets through setsockopt In case1, the SRH can be encoded in the Reduced way (i.e., first SID is carried in DA only and not represented as SID in the SRH) and the seg6_validate_srh() now handles this case correctly. In case2 and case3, the SRH shouldn’t be encoded in the Reduced way otherwise we lose the first segment (i.e., the first hop). The current implementation of the seg6_validate_srh() allow SRH of case2 and case3 to be encoded in the Reduced way. This leads a slab-out-of-bounds problem. This patch verifies SRH of case1, case2 and case3. Allowing case1 to be reduced while preventing SRH of case2 and case3 from being reduced . Reported-by: syzbot+e8c028b62439eac42073@syzkaller.appspotmail.com Reported-by: YueHaibing <yuehaibing@huawei.com> Fixes: 0cb7498f234e ("seg6: fix SRH processing to comply with RFC8754") Signed-off-by: Ahmed Abdelsalam <ahabdels@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-03 09:54:42 +03:00
if (!seg6_validate_srh(srh, len, false))
ipv6: sr: add rtnetlink functions for seg6local action parameters This patch adds the necessary functions to parse, fill, and compare seg6local rtnetlink attributes, for all defined action parameters. - The SRH parameter defines an SRH to be inserted or encapsulated. - The TABLE parameter defines the table to use for the route lookup of the next segment or the inner decapsulated packet. - The NH4 parameter defines the IPv4 next-hop for an inner decapsulated IPv4 packet. - The NH6 parameter defines the IPv6 next-hop for the next segment or for an inner decapsulated IPv6 packet - The IIF parameter defines an ingress interface index. - The OIF parameter defines an egress interface index. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:27 +03:00
return -EINVAL;
ipv6: sr: Use kmemdup instead of duplicating it in parse_nla_srh Replace calls to kmalloc followed by a memcpy with a direct call to kmemdup. Signed-off-by: YueHaibing <yuehaibing@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-23 11:33:19 +03:00
slwt->srh = kmemdup(srh, len, GFP_KERNEL);
ipv6: sr: add rtnetlink functions for seg6local action parameters This patch adds the necessary functions to parse, fill, and compare seg6local rtnetlink attributes, for all defined action parameters. - The SRH parameter defines an SRH to be inserted or encapsulated. - The TABLE parameter defines the table to use for the route lookup of the next segment or the inner decapsulated packet. - The NH4 parameter defines the IPv4 next-hop for an inner decapsulated IPv4 packet. - The NH6 parameter defines the IPv6 next-hop for the next segment or for an inner decapsulated IPv6 packet - The IIF parameter defines an ingress interface index. - The OIF parameter defines an egress interface index. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:27 +03:00
if (!slwt->srh)
return -ENOMEM;
slwt->headroom += len;
return 0;
}
static int put_nla_srh(struct sk_buff *skb, struct seg6_local_lwt *slwt)
{
struct ipv6_sr_hdr *srh;
struct nlattr *nla;
int len;
srh = slwt->srh;
len = (srh->hdrlen + 1) << 3;
nla = nla_reserve(skb, SEG6_LOCAL_SRH, len);
if (!nla)
return -EMSGSIZE;
memcpy(nla_data(nla), srh, len);
return 0;
}
static int cmp_nla_srh(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
{
int len = (a->srh->hdrlen + 1) << 3;
if (len != ((b->srh->hdrlen + 1) << 3))
return 1;
return memcmp(a->srh, b->srh, len);
}
seg6: improve management of behavior attributes Depending on the attribute (i.e.: SEG6_LOCAL_SRH, SEG6_LOCAL_TABLE, etc), the parse() callback performs some validity checks on the provided input and updates the tunnel state (slwt) with the result of the parsing operation. However, an attribute may also need to reserve some additional resources (i.e.: memory or setting up an eBPF program) in the parse() callback to complete the parsing operation. The parse() callbacks are invoked by the parse_nla_action() for each attribute belonging to a specific behavior. Given a behavior with N attributes, if the parsing of the i-th attribute fails, the parse_nla_action() returns immediately with an error. Nonetheless, the resources acquired during the parsing of the i-1 attributes are not freed by the parse_nla_action(). Attributes which acquire resources must release them *in an explicit way* in both the seg6_local_{build/destroy}_state(). However, adding a new attribute of this type requires changes to seg6_local_{build/destroy}_state() to release the resources correctly. The seg6local infrastructure still lacks a simple and structured way to release the resources acquired in the parse() operations. We introduced a new callback in the struct seg6_action_param named destroy(). This callback releases any resource which may have been acquired in the parse() counterpart. Each attribute may or may not implement the destroy() callback depending on whether it needs to free some acquired resources. The destroy() callback comes with several of advantages: 1) we can have many attributes as we want for a given behavior with no need to explicitly free the taken resources; 2) As in case of the seg6_local_build_state(), the seg6_local_destroy_state() does not need to handle the release of resources directly. Indeed, it calls the destroy_attrs() function which is in charge of calling the destroy() callback for every set attribute. We do not need to patch seg6_local_{build/destroy}_state() anymore as we add new attributes; 3) the code is more readable and better structured. Indeed, all the information needed to handle a given attribute are contained in only one place; 4) it facilitates the integration with new features introduced in further patches. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:11 +03:00
static void destroy_attr_srh(struct seg6_local_lwt *slwt)
{
kfree(slwt->srh);
}
seg6: add netlink_ext_ack support in parsing SRv6 behavior attributes An SRv6 behavior instance can be set up using mandatory and/or optional attributes. In the setup phase, each supplied attribute is parsed and processed. If the parsing operation fails, the creation of the behavior instance stops and an error number/code is reported to the user. In many cases, it is challenging for the user to figure out exactly what happened by relying only on the error code. For this reason, we add the support for netlink_ext_ack in parsing SRv6 behavior attributes. In this way, when an SRv6 behavior attribute is parsed and an error occurs, the kernel can send a message to the userspace describing the error through a meaningful text message in addition to the classic error code. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-09-12 20:16:17 +03:00
static int parse_nla_table(struct nlattr **attrs, struct seg6_local_lwt *slwt,
struct netlink_ext_ack *extack)
ipv6: sr: add rtnetlink functions for seg6local action parameters This patch adds the necessary functions to parse, fill, and compare seg6local rtnetlink attributes, for all defined action parameters. - The SRH parameter defines an SRH to be inserted or encapsulated. - The TABLE parameter defines the table to use for the route lookup of the next segment or the inner decapsulated packet. - The NH4 parameter defines the IPv4 next-hop for an inner decapsulated IPv4 packet. - The NH6 parameter defines the IPv6 next-hop for the next segment or for an inner decapsulated IPv6 packet - The IIF parameter defines an ingress interface index. - The OIF parameter defines an egress interface index. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:27 +03:00
{
slwt->table = nla_get_u32(attrs[SEG6_LOCAL_TABLE]);
return 0;
}
static int put_nla_table(struct sk_buff *skb, struct seg6_local_lwt *slwt)
{
if (nla_put_u32(skb, SEG6_LOCAL_TABLE, slwt->table))
return -EMSGSIZE;
return 0;
}
static int cmp_nla_table(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
{
if (a->table != b->table)
return 1;
return 0;
}
seg6: add support for the SRv6 End.DT4 behavior SRv6 End.DT4 is defined in the SRv6 Network Programming [1]. The SRv6 End.DT4 is used to implement IPv4 L3VPN use-cases in multi-tenants environments. It decapsulates the received packets and it performs IPv4 routing lookup in the routing table of the tenant. The SRv6 End.DT4 Linux implementation leverages a VRF device in order to force the routing lookup into the associated routing table. To make the End.DT4 work properly, it must be guaranteed that the routing table used for routing lookup operations is bound to one and only one VRF during the tunnel creation. Such constraint has to be enforced by enabling the VRF strict_mode sysctl parameter, i.e: $ sysctl -wq net.vrf.strict_mode=1. At JANOG44, LINE corporation presented their multi-tenant DC architecture using SRv6 [2]. In the slides, they reported that the Linux kernel is missing the support of SRv6 End.DT4 behavior. The SRv6 End.DT4 behavior can be instantiated using a command similar to the following: $ ip route add 2001:db8::1 encap seg6local action End.DT4 vrftable 100 dev eth0 We introduce the "vrftable" extension in iproute2 in a following patch. [1] https://tools.ietf.org/html/draft-ietf-spring-srv6-network-programming [2] https://speakerdeck.com/line_developers/line-data-center-networking-with-srv6 Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:14 +03:00
static struct
seg6_end_dt_info *seg6_possible_end_dt_info(struct seg6_local_lwt *slwt)
{
#ifdef CONFIG_NET_L3_MASTER_DEV
return &slwt->dt_info;
#else
return ERR_PTR(-EOPNOTSUPP);
#endif
}
static int parse_nla_vrftable(struct nlattr **attrs,
seg6: add netlink_ext_ack support in parsing SRv6 behavior attributes An SRv6 behavior instance can be set up using mandatory and/or optional attributes. In the setup phase, each supplied attribute is parsed and processed. If the parsing operation fails, the creation of the behavior instance stops and an error number/code is reported to the user. In many cases, it is challenging for the user to figure out exactly what happened by relying only on the error code. For this reason, we add the support for netlink_ext_ack in parsing SRv6 behavior attributes. In this way, when an SRv6 behavior attribute is parsed and an error occurs, the kernel can send a message to the userspace describing the error through a meaningful text message in addition to the classic error code. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-09-12 20:16:17 +03:00
struct seg6_local_lwt *slwt,
struct netlink_ext_ack *extack)
seg6: add support for the SRv6 End.DT4 behavior SRv6 End.DT4 is defined in the SRv6 Network Programming [1]. The SRv6 End.DT4 is used to implement IPv4 L3VPN use-cases in multi-tenants environments. It decapsulates the received packets and it performs IPv4 routing lookup in the routing table of the tenant. The SRv6 End.DT4 Linux implementation leverages a VRF device in order to force the routing lookup into the associated routing table. To make the End.DT4 work properly, it must be guaranteed that the routing table used for routing lookup operations is bound to one and only one VRF during the tunnel creation. Such constraint has to be enforced by enabling the VRF strict_mode sysctl parameter, i.e: $ sysctl -wq net.vrf.strict_mode=1. At JANOG44, LINE corporation presented their multi-tenant DC architecture using SRv6 [2]. In the slides, they reported that the Linux kernel is missing the support of SRv6 End.DT4 behavior. The SRv6 End.DT4 behavior can be instantiated using a command similar to the following: $ ip route add 2001:db8::1 encap seg6local action End.DT4 vrftable 100 dev eth0 We introduce the "vrftable" extension in iproute2 in a following patch. [1] https://tools.ietf.org/html/draft-ietf-spring-srv6-network-programming [2] https://speakerdeck.com/line_developers/line-data-center-networking-with-srv6 Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:14 +03:00
{
struct seg6_end_dt_info *info = seg6_possible_end_dt_info(slwt);
if (IS_ERR(info))
return PTR_ERR(info);
info->vrf_table = nla_get_u32(attrs[SEG6_LOCAL_VRFTABLE]);
return 0;
}
static int put_nla_vrftable(struct sk_buff *skb, struct seg6_local_lwt *slwt)
{
struct seg6_end_dt_info *info = seg6_possible_end_dt_info(slwt);
if (IS_ERR(info))
return PTR_ERR(info);
if (nla_put_u32(skb, SEG6_LOCAL_VRFTABLE, info->vrf_table))
return -EMSGSIZE;
return 0;
}
static int cmp_nla_vrftable(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
{
struct seg6_end_dt_info *info_a = seg6_possible_end_dt_info(a);
struct seg6_end_dt_info *info_b = seg6_possible_end_dt_info(b);
if (info_a->vrf_table != info_b->vrf_table)
return 1;
return 0;
}
seg6: add netlink_ext_ack support in parsing SRv6 behavior attributes An SRv6 behavior instance can be set up using mandatory and/or optional attributes. In the setup phase, each supplied attribute is parsed and processed. If the parsing operation fails, the creation of the behavior instance stops and an error number/code is reported to the user. In many cases, it is challenging for the user to figure out exactly what happened by relying only on the error code. For this reason, we add the support for netlink_ext_ack in parsing SRv6 behavior attributes. In this way, when an SRv6 behavior attribute is parsed and an error occurs, the kernel can send a message to the userspace describing the error through a meaningful text message in addition to the classic error code. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-09-12 20:16:17 +03:00
static int parse_nla_nh4(struct nlattr **attrs, struct seg6_local_lwt *slwt,
struct netlink_ext_ack *extack)
ipv6: sr: add rtnetlink functions for seg6local action parameters This patch adds the necessary functions to parse, fill, and compare seg6local rtnetlink attributes, for all defined action parameters. - The SRH parameter defines an SRH to be inserted or encapsulated. - The TABLE parameter defines the table to use for the route lookup of the next segment or the inner decapsulated packet. - The NH4 parameter defines the IPv4 next-hop for an inner decapsulated IPv4 packet. - The NH6 parameter defines the IPv6 next-hop for the next segment or for an inner decapsulated IPv6 packet - The IIF parameter defines an ingress interface index. - The OIF parameter defines an egress interface index. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:27 +03:00
{
memcpy(&slwt->nh4, nla_data(attrs[SEG6_LOCAL_NH4]),
sizeof(struct in_addr));
return 0;
}
static int put_nla_nh4(struct sk_buff *skb, struct seg6_local_lwt *slwt)
{
struct nlattr *nla;
nla = nla_reserve(skb, SEG6_LOCAL_NH4, sizeof(struct in_addr));
if (!nla)
return -EMSGSIZE;
memcpy(nla_data(nla), &slwt->nh4, sizeof(struct in_addr));
return 0;
}
static int cmp_nla_nh4(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
{
return memcmp(&a->nh4, &b->nh4, sizeof(struct in_addr));
}
seg6: add netlink_ext_ack support in parsing SRv6 behavior attributes An SRv6 behavior instance can be set up using mandatory and/or optional attributes. In the setup phase, each supplied attribute is parsed and processed. If the parsing operation fails, the creation of the behavior instance stops and an error number/code is reported to the user. In many cases, it is challenging for the user to figure out exactly what happened by relying only on the error code. For this reason, we add the support for netlink_ext_ack in parsing SRv6 behavior attributes. In this way, when an SRv6 behavior attribute is parsed and an error occurs, the kernel can send a message to the userspace describing the error through a meaningful text message in addition to the classic error code. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-09-12 20:16:17 +03:00
static int parse_nla_nh6(struct nlattr **attrs, struct seg6_local_lwt *slwt,
struct netlink_ext_ack *extack)
ipv6: sr: add rtnetlink functions for seg6local action parameters This patch adds the necessary functions to parse, fill, and compare seg6local rtnetlink attributes, for all defined action parameters. - The SRH parameter defines an SRH to be inserted or encapsulated. - The TABLE parameter defines the table to use for the route lookup of the next segment or the inner decapsulated packet. - The NH4 parameter defines the IPv4 next-hop for an inner decapsulated IPv4 packet. - The NH6 parameter defines the IPv6 next-hop for the next segment or for an inner decapsulated IPv6 packet - The IIF parameter defines an ingress interface index. - The OIF parameter defines an egress interface index. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:27 +03:00
{
memcpy(&slwt->nh6, nla_data(attrs[SEG6_LOCAL_NH6]),
sizeof(struct in6_addr));
return 0;
}
static int put_nla_nh6(struct sk_buff *skb, struct seg6_local_lwt *slwt)
{
struct nlattr *nla;
nla = nla_reserve(skb, SEG6_LOCAL_NH6, sizeof(struct in6_addr));
if (!nla)
return -EMSGSIZE;
memcpy(nla_data(nla), &slwt->nh6, sizeof(struct in6_addr));
return 0;
}
static int cmp_nla_nh6(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
{
return memcmp(&a->nh6, &b->nh6, sizeof(struct in6_addr));
}
seg6: add netlink_ext_ack support in parsing SRv6 behavior attributes An SRv6 behavior instance can be set up using mandatory and/or optional attributes. In the setup phase, each supplied attribute is parsed and processed. If the parsing operation fails, the creation of the behavior instance stops and an error number/code is reported to the user. In many cases, it is challenging for the user to figure out exactly what happened by relying only on the error code. For this reason, we add the support for netlink_ext_ack in parsing SRv6 behavior attributes. In this way, when an SRv6 behavior attribute is parsed and an error occurs, the kernel can send a message to the userspace describing the error through a meaningful text message in addition to the classic error code. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-09-12 20:16:17 +03:00
static int parse_nla_iif(struct nlattr **attrs, struct seg6_local_lwt *slwt,
struct netlink_ext_ack *extack)
ipv6: sr: add rtnetlink functions for seg6local action parameters This patch adds the necessary functions to parse, fill, and compare seg6local rtnetlink attributes, for all defined action parameters. - The SRH parameter defines an SRH to be inserted or encapsulated. - The TABLE parameter defines the table to use for the route lookup of the next segment or the inner decapsulated packet. - The NH4 parameter defines the IPv4 next-hop for an inner decapsulated IPv4 packet. - The NH6 parameter defines the IPv6 next-hop for the next segment or for an inner decapsulated IPv6 packet - The IIF parameter defines an ingress interface index. - The OIF parameter defines an egress interface index. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:27 +03:00
{
slwt->iif = nla_get_u32(attrs[SEG6_LOCAL_IIF]);
return 0;
}
static int put_nla_iif(struct sk_buff *skb, struct seg6_local_lwt *slwt)
{
if (nla_put_u32(skb, SEG6_LOCAL_IIF, slwt->iif))
return -EMSGSIZE;
return 0;
}
static int cmp_nla_iif(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
{
if (a->iif != b->iif)
return 1;
return 0;
}
seg6: add netlink_ext_ack support in parsing SRv6 behavior attributes An SRv6 behavior instance can be set up using mandatory and/or optional attributes. In the setup phase, each supplied attribute is parsed and processed. If the parsing operation fails, the creation of the behavior instance stops and an error number/code is reported to the user. In many cases, it is challenging for the user to figure out exactly what happened by relying only on the error code. For this reason, we add the support for netlink_ext_ack in parsing SRv6 behavior attributes. In this way, when an SRv6 behavior attribute is parsed and an error occurs, the kernel can send a message to the userspace describing the error through a meaningful text message in addition to the classic error code. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-09-12 20:16:17 +03:00
static int parse_nla_oif(struct nlattr **attrs, struct seg6_local_lwt *slwt,
struct netlink_ext_ack *extack)
ipv6: sr: add rtnetlink functions for seg6local action parameters This patch adds the necessary functions to parse, fill, and compare seg6local rtnetlink attributes, for all defined action parameters. - The SRH parameter defines an SRH to be inserted or encapsulated. - The TABLE parameter defines the table to use for the route lookup of the next segment or the inner decapsulated packet. - The NH4 parameter defines the IPv4 next-hop for an inner decapsulated IPv4 packet. - The NH6 parameter defines the IPv6 next-hop for the next segment or for an inner decapsulated IPv6 packet - The IIF parameter defines an ingress interface index. - The OIF parameter defines an egress interface index. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:27 +03:00
{
slwt->oif = nla_get_u32(attrs[SEG6_LOCAL_OIF]);
return 0;
}
static int put_nla_oif(struct sk_buff *skb, struct seg6_local_lwt *slwt)
{
if (nla_put_u32(skb, SEG6_LOCAL_OIF, slwt->oif))
return -EMSGSIZE;
return 0;
}
static int cmp_nla_oif(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
{
if (a->oif != b->oif)
return 1;
return 0;
}
ipv6: sr: Add seg6local action End.BPF This patch adds the End.BPF action to the LWT seg6local infrastructure. This action works like any other seg6local End action, meaning that an IPv6 header with SRH is needed, whose DA has to be equal to the SID of the action. It will also advance the SRH to the next segment, the BPF program does not have to take care of this. Since the BPF program may not be a source of instability in the kernel, it is important to ensure that the integrity of the packet is maintained before yielding it back to the IPv6 layer. The hook hence keeps track if the SRH has been altered through the helpers, and re-validates its content if needed with seg6_validate_srh. The state kept for validation is stored in a per-CPU buffer. The BPF program is not allowed to directly write into the packet, and only some fields of the SRH can be altered through the helper bpf_lwt_seg6_store_bytes. Performances profiling has shown that the SRH re-validation does not induce a significant overhead. If the altered SRH is deemed as invalid, the packet is dropped. This validation is also done before executing any action through bpf_lwt_seg6_action, and will not be performed again if the SRH is not modified after calling the action. The BPF program may return 3 types of return codes: - BPF_OK: the End.BPF action will look up the next destination through seg6_lookup_nexthop. - BPF_REDIRECT: if an action has been executed through the bpf_lwt_seg6_action helper, the BPF program should return this value, as the skb's destination is already set and the default lookup should not be performed. - BPF_DROP : the packet will be dropped. Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-20 16:58:16 +03:00
#define MAX_PROG_NAME 256
static const struct nla_policy bpf_prog_policy[SEG6_LOCAL_BPF_PROG_MAX + 1] = {
[SEG6_LOCAL_BPF_PROG] = { .type = NLA_U32, },
[SEG6_LOCAL_BPF_PROG_NAME] = { .type = NLA_NUL_STRING,
.len = MAX_PROG_NAME },
};
seg6: add netlink_ext_ack support in parsing SRv6 behavior attributes An SRv6 behavior instance can be set up using mandatory and/or optional attributes. In the setup phase, each supplied attribute is parsed and processed. If the parsing operation fails, the creation of the behavior instance stops and an error number/code is reported to the user. In many cases, it is challenging for the user to figure out exactly what happened by relying only on the error code. For this reason, we add the support for netlink_ext_ack in parsing SRv6 behavior attributes. In this way, when an SRv6 behavior attribute is parsed and an error occurs, the kernel can send a message to the userspace describing the error through a meaningful text message in addition to the classic error code. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-09-12 20:16:17 +03:00
static int parse_nla_bpf(struct nlattr **attrs, struct seg6_local_lwt *slwt,
struct netlink_ext_ack *extack)
ipv6: sr: Add seg6local action End.BPF This patch adds the End.BPF action to the LWT seg6local infrastructure. This action works like any other seg6local End action, meaning that an IPv6 header with SRH is needed, whose DA has to be equal to the SID of the action. It will also advance the SRH to the next segment, the BPF program does not have to take care of this. Since the BPF program may not be a source of instability in the kernel, it is important to ensure that the integrity of the packet is maintained before yielding it back to the IPv6 layer. The hook hence keeps track if the SRH has been altered through the helpers, and re-validates its content if needed with seg6_validate_srh. The state kept for validation is stored in a per-CPU buffer. The BPF program is not allowed to directly write into the packet, and only some fields of the SRH can be altered through the helper bpf_lwt_seg6_store_bytes. Performances profiling has shown that the SRH re-validation does not induce a significant overhead. If the altered SRH is deemed as invalid, the packet is dropped. This validation is also done before executing any action through bpf_lwt_seg6_action, and will not be performed again if the SRH is not modified after calling the action. The BPF program may return 3 types of return codes: - BPF_OK: the End.BPF action will look up the next destination through seg6_lookup_nexthop. - BPF_REDIRECT: if an action has been executed through the bpf_lwt_seg6_action helper, the BPF program should return this value, as the skb's destination is already set and the default lookup should not be performed. - BPF_DROP : the packet will be dropped. Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-20 16:58:16 +03:00
{
struct nlattr *tb[SEG6_LOCAL_BPF_PROG_MAX + 1];
struct bpf_prog *p;
int ret;
u32 fd;
netlink: make validation more configurable for future strictness We currently have two levels of strict validation: 1) liberal (default) - undefined (type >= max) & NLA_UNSPEC attributes accepted - attribute length >= expected accepted - garbage at end of message accepted 2) strict (opt-in) - NLA_UNSPEC attributes accepted - attribute length >= expected accepted Split out parsing strictness into four different options: * TRAILING - check that there's no trailing data after parsing attributes (in message or nested) * MAXTYPE - reject attrs > max known type * UNSPEC - reject attributes with NLA_UNSPEC policy entries * STRICT_ATTRS - strictly validate attribute size The default for future things should be *everything*. The current *_strict() is a combination of TRAILING and MAXTYPE, and is renamed to _deprecated_strict(). The current regular parsing has none of this, and is renamed to *_parse_deprecated(). Additionally it allows us to selectively set one of the new flags even on old policies. Notably, the UNSPEC flag could be useful in this case, since it can be arranged (by filling in the policy) to not be an incompatible userspace ABI change, but would then going forward prevent forgetting attribute entries. Similar can apply to the POLICY flag. We end up with the following renames: * nla_parse -> nla_parse_deprecated * nla_parse_strict -> nla_parse_deprecated_strict * nlmsg_parse -> nlmsg_parse_deprecated * nlmsg_parse_strict -> nlmsg_parse_deprecated_strict * nla_parse_nested -> nla_parse_nested_deprecated * nla_validate_nested -> nla_validate_nested_deprecated Using spatch, of course: @@ expression TB, MAX, HEAD, LEN, POL, EXT; @@ -nla_parse(TB, MAX, HEAD, LEN, POL, EXT) +nla_parse_deprecated(TB, MAX, HEAD, LEN, POL, EXT) @@ expression NLH, HDRLEN, TB, MAX, POL, EXT; @@ -nlmsg_parse(NLH, HDRLEN, TB, MAX, POL, EXT) +nlmsg_parse_deprecated(NLH, HDRLEN, TB, MAX, POL, EXT) @@ expression NLH, HDRLEN, TB, MAX, POL, EXT; @@ -nlmsg_parse_strict(NLH, HDRLEN, TB, MAX, POL, EXT) +nlmsg_parse_deprecated_strict(NLH, HDRLEN, TB, MAX, POL, EXT) @@ expression TB, MAX, NLA, POL, EXT; @@ -nla_parse_nested(TB, MAX, NLA, POL, EXT) +nla_parse_nested_deprecated(TB, MAX, NLA, POL, EXT) @@ expression START, MAX, POL, EXT; @@ -nla_validate_nested(START, MAX, POL, EXT) +nla_validate_nested_deprecated(START, MAX, POL, EXT) @@ expression NLH, HDRLEN, MAX, POL, EXT; @@ -nlmsg_validate(NLH, HDRLEN, MAX, POL, EXT) +nlmsg_validate_deprecated(NLH, HDRLEN, MAX, POL, EXT) For this patch, don't actually add the strict, non-renamed versions yet so that it breaks compile if I get it wrong. Also, while at it, make nla_validate and nla_parse go down to a common __nla_validate_parse() function to avoid code duplication. Ultimately, this allows us to have very strict validation for every new caller of nla_parse()/nlmsg_parse() etc as re-introduced in the next patch, while existing things will continue to work as is. In effect then, this adds fully strict validation for any new command. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-26 15:07:28 +03:00
ret = nla_parse_nested_deprecated(tb, SEG6_LOCAL_BPF_PROG_MAX,
attrs[SEG6_LOCAL_BPF],
bpf_prog_policy, NULL);
ipv6: sr: Add seg6local action End.BPF This patch adds the End.BPF action to the LWT seg6local infrastructure. This action works like any other seg6local End action, meaning that an IPv6 header with SRH is needed, whose DA has to be equal to the SID of the action. It will also advance the SRH to the next segment, the BPF program does not have to take care of this. Since the BPF program may not be a source of instability in the kernel, it is important to ensure that the integrity of the packet is maintained before yielding it back to the IPv6 layer. The hook hence keeps track if the SRH has been altered through the helpers, and re-validates its content if needed with seg6_validate_srh. The state kept for validation is stored in a per-CPU buffer. The BPF program is not allowed to directly write into the packet, and only some fields of the SRH can be altered through the helper bpf_lwt_seg6_store_bytes. Performances profiling has shown that the SRH re-validation does not induce a significant overhead. If the altered SRH is deemed as invalid, the packet is dropped. This validation is also done before executing any action through bpf_lwt_seg6_action, and will not be performed again if the SRH is not modified after calling the action. The BPF program may return 3 types of return codes: - BPF_OK: the End.BPF action will look up the next destination through seg6_lookup_nexthop. - BPF_REDIRECT: if an action has been executed through the bpf_lwt_seg6_action helper, the BPF program should return this value, as the skb's destination is already set and the default lookup should not be performed. - BPF_DROP : the packet will be dropped. Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-20 16:58:16 +03:00
if (ret < 0)
return ret;
if (!tb[SEG6_LOCAL_BPF_PROG] || !tb[SEG6_LOCAL_BPF_PROG_NAME])
return -EINVAL;
slwt->bpf.name = nla_memdup(tb[SEG6_LOCAL_BPF_PROG_NAME], GFP_KERNEL);
if (!slwt->bpf.name)
return -ENOMEM;
fd = nla_get_u32(tb[SEG6_LOCAL_BPF_PROG]);
p = bpf_prog_get_type(fd, BPF_PROG_TYPE_LWT_SEG6LOCAL);
if (IS_ERR(p)) {
kfree(slwt->bpf.name);
return PTR_ERR(p);
}
slwt->bpf.prog = p;
return 0;
}
static int put_nla_bpf(struct sk_buff *skb, struct seg6_local_lwt *slwt)
{
struct nlattr *nest;
if (!slwt->bpf.prog)
return 0;
netlink: make nla_nest_start() add NLA_F_NESTED flag Even if the NLA_F_NESTED flag was introduced more than 11 years ago, most netlink based interfaces (including recently added ones) are still not setting it in kernel generated messages. Without the flag, message parsers not aware of attribute semantics (e.g. wireshark dissector or libmnl's mnl_nlmsg_fprintf()) cannot recognize nested attributes and won't display the structure of their contents. Unfortunately we cannot just add the flag everywhere as there may be userspace applications which check nlattr::nla_type directly rather than through a helper masking out the flags. Therefore the patch renames nla_nest_start() to nla_nest_start_noflag() and introduces nla_nest_start() as a wrapper adding NLA_F_NESTED. The calls which add NLA_F_NESTED manually are rewritten to use nla_nest_start(). Except for changes in include/net/netlink.h, the patch was generated using this semantic patch: @@ expression E1, E2; @@ -nla_nest_start(E1, E2) +nla_nest_start_noflag(E1, E2) @@ expression E1, E2; @@ -nla_nest_start_noflag(E1, E2 | NLA_F_NESTED) +nla_nest_start(E1, E2) Signed-off-by: Michal Kubecek <mkubecek@suse.cz> Acked-by: Jiri Pirko <jiri@mellanox.com> Acked-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-26 12:13:06 +03:00
nest = nla_nest_start_noflag(skb, SEG6_LOCAL_BPF);
ipv6: sr: Add seg6local action End.BPF This patch adds the End.BPF action to the LWT seg6local infrastructure. This action works like any other seg6local End action, meaning that an IPv6 header with SRH is needed, whose DA has to be equal to the SID of the action. It will also advance the SRH to the next segment, the BPF program does not have to take care of this. Since the BPF program may not be a source of instability in the kernel, it is important to ensure that the integrity of the packet is maintained before yielding it back to the IPv6 layer. The hook hence keeps track if the SRH has been altered through the helpers, and re-validates its content if needed with seg6_validate_srh. The state kept for validation is stored in a per-CPU buffer. The BPF program is not allowed to directly write into the packet, and only some fields of the SRH can be altered through the helper bpf_lwt_seg6_store_bytes. Performances profiling has shown that the SRH re-validation does not induce a significant overhead. If the altered SRH is deemed as invalid, the packet is dropped. This validation is also done before executing any action through bpf_lwt_seg6_action, and will not be performed again if the SRH is not modified after calling the action. The BPF program may return 3 types of return codes: - BPF_OK: the End.BPF action will look up the next destination through seg6_lookup_nexthop. - BPF_REDIRECT: if an action has been executed through the bpf_lwt_seg6_action helper, the BPF program should return this value, as the skb's destination is already set and the default lookup should not be performed. - BPF_DROP : the packet will be dropped. Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-20 16:58:16 +03:00
if (!nest)
return -EMSGSIZE;
if (nla_put_u32(skb, SEG6_LOCAL_BPF_PROG, slwt->bpf.prog->aux->id))
return -EMSGSIZE;
if (slwt->bpf.name &&
nla_put_string(skb, SEG6_LOCAL_BPF_PROG_NAME, slwt->bpf.name))
return -EMSGSIZE;
return nla_nest_end(skb, nest);
}
static int cmp_nla_bpf(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
{
if (!a->bpf.name && !b->bpf.name)
return 0;
if (!a->bpf.name || !b->bpf.name)
return 1;
return strcmp(a->bpf.name, b->bpf.name);
}
seg6: improve management of behavior attributes Depending on the attribute (i.e.: SEG6_LOCAL_SRH, SEG6_LOCAL_TABLE, etc), the parse() callback performs some validity checks on the provided input and updates the tunnel state (slwt) with the result of the parsing operation. However, an attribute may also need to reserve some additional resources (i.e.: memory or setting up an eBPF program) in the parse() callback to complete the parsing operation. The parse() callbacks are invoked by the parse_nla_action() for each attribute belonging to a specific behavior. Given a behavior with N attributes, if the parsing of the i-th attribute fails, the parse_nla_action() returns immediately with an error. Nonetheless, the resources acquired during the parsing of the i-1 attributes are not freed by the parse_nla_action(). Attributes which acquire resources must release them *in an explicit way* in both the seg6_local_{build/destroy}_state(). However, adding a new attribute of this type requires changes to seg6_local_{build/destroy}_state() to release the resources correctly. The seg6local infrastructure still lacks a simple and structured way to release the resources acquired in the parse() operations. We introduced a new callback in the struct seg6_action_param named destroy(). This callback releases any resource which may have been acquired in the parse() counterpart. Each attribute may or may not implement the destroy() callback depending on whether it needs to free some acquired resources. The destroy() callback comes with several of advantages: 1) we can have many attributes as we want for a given behavior with no need to explicitly free the taken resources; 2) As in case of the seg6_local_build_state(), the seg6_local_destroy_state() does not need to handle the release of resources directly. Indeed, it calls the destroy_attrs() function which is in charge of calling the destroy() callback for every set attribute. We do not need to patch seg6_local_{build/destroy}_state() anymore as we add new attributes; 3) the code is more readable and better structured. Indeed, all the information needed to handle a given attribute are contained in only one place; 4) it facilitates the integration with new features introduced in further patches. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:11 +03:00
static void destroy_attr_bpf(struct seg6_local_lwt *slwt)
{
kfree(slwt->bpf.name);
if (slwt->bpf.prog)
bpf_prog_put(slwt->bpf.prog);
}
seg6: add counters support for SRv6 Behaviors This patch provides counters for SRv6 Behaviors as defined in [1], section 6. For each SRv6 Behavior instance, counters defined in [1] are: - the total number of packets that have been correctly processed; - the total amount of traffic in bytes of all packets that have been correctly processed; In addition, this patch introduces a new counter that counts the number of packets that have NOT been properly processed (i.e. errors) by an SRv6 Behavior instance. Counters are not only interesting for network monitoring purposes (i.e. counting the number of packets processed by a given behavior) but they also provide a simple tool for checking whether a behavior instance is working as we expect or not. Counters can be useful for troubleshooting misconfigured SRv6 networks. Indeed, an SRv6 Behavior can silently drop packets for very different reasons (i.e. wrong SID configuration, interfaces set with SID addresses, etc) without any notification/message to the user. Due to the nature of SRv6 networks, diagnostic tools such as ping and traceroute may be ineffective: paths used for reaching a given router can be totally different from the ones followed by probe packets. In addition, paths are often asymmetrical and this makes it even more difficult to keep up with the journey of the packets and to understand which behaviors are actually processing our traffic. When counters are enabled on an SRv6 Behavior instance, it is possible to verify if packets are actually processed by such behavior and what is the outcome of the processing. Therefore, the counters for SRv6 Behaviors offer an non-invasive observability point which can be leveraged for both traffic monitoring and troubleshooting purposes. [1] https://www.rfc-editor.org/rfc/rfc8986.html#name-counters Troubleshooting using SRv6 Behavior counters -------------------------------------------- Let's make a brief example to see how helpful counters can be for SRv6 networks. Let's consider a node where an SRv6 End Behavior receives an SRv6 packet whose Segment Left (SL) is equal to 0. In this case, the End Behavior (which accepts only packets with SL >= 1) discards the packet and increases the error counter. This information can be leveraged by the network operator for troubleshooting. Indeed, the error counter is telling the user that the packet: (i) arrived at the node; (ii) the packet has been taken into account by the SRv6 End behavior; (iii) but an error has occurred during the processing. The error (iii) could be caused by different reasons, such as wrong route settings on the node or due to an invalid SID List carried by the SRv6 packet. Anyway, the error counter is used to exclude that the packet did not arrive at the node or it has not been processed by the behavior at all. Turning on/off counters for SRv6 Behaviors ------------------------------------------ Each SRv6 Behavior instance can be configured, at the time of its creation, to make use of counters. This is done through iproute2 which allows the user to create an SRv6 Behavior instance specifying the optional "count" attribute as shown in the following example: $ ip -6 route add 2001:db8::1 encap seg6local action End count dev eth0 per-behavior counters can be shown by adding "-s" to the iproute2 command line, i.e.: $ ip -s -6 route show 2001:db8::1 2001:db8::1 encap seg6local action End packets 0 bytes 0 errors 0 dev eth0 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Impact of counters for SRv6 Behaviors on performance ==================================================== To determine the performance impact due to the introduction of counters in the SRv6 Behavior subsystem, we have carried out extensive tests. We chose to test the throughput achieved by the SRv6 End.DX2 Behavior because, among all the other behaviors implemented so far, it reaches the highest throughput which is around 1.5 Mpps (per core at 2.4 GHz on a Xeon(R) CPU E5-2630 v3) on kernel 5.12-rc2 using packets of size ~ 100 bytes. Three different tests were conducted in order to evaluate the overall throughput of the SRv6 End.DX2 Behavior in the following scenarios: 1) vanilla kernel (without the SRv6 Behavior counters patch) and a single instance of an SRv6 End.DX2 Behavior; 2) patched kernel with SRv6 Behavior counters and a single instance of an SRv6 End.DX2 Behavior with counters turned off; 3) patched kernel with SRv6 Behavior counters and a single instance of SRv6 End.DX2 Behavior with counters turned on. All tests were performed on a testbed deployed on the CloudLab facilities [2], a flexible infrastructure dedicated to scientific research on the future of Cloud Computing. Results of tests are shown in the following table: Scenario (1): average 1504764,81 pps (~1504,76 kpps); std. dev 3956,82 pps Scenario (2): average 1501469,78 pps (~1501,47 kpps); std. dev 2979,85 pps Scenario (3): average 1501315,13 pps (~1501,32 kpps); std. dev 2956,00 pps As can be observed, throughputs achieved in scenarios (2),(3) did not suffer any observable degradation compared to scenario (1). Thanks to Jakub Kicinski and David Ahern for their valuable suggestions and comments provided during the discussion of the proposed RFCs. [2] https://www.cloudlab.us Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-04-27 18:44:04 +03:00
static const struct
nla_policy seg6_local_counters_policy[SEG6_LOCAL_CNT_MAX + 1] = {
[SEG6_LOCAL_CNT_PACKETS] = { .type = NLA_U64 },
[SEG6_LOCAL_CNT_BYTES] = { .type = NLA_U64 },
[SEG6_LOCAL_CNT_ERRORS] = { .type = NLA_U64 },
};
static int parse_nla_counters(struct nlattr **attrs,
seg6: add netlink_ext_ack support in parsing SRv6 behavior attributes An SRv6 behavior instance can be set up using mandatory and/or optional attributes. In the setup phase, each supplied attribute is parsed and processed. If the parsing operation fails, the creation of the behavior instance stops and an error number/code is reported to the user. In many cases, it is challenging for the user to figure out exactly what happened by relying only on the error code. For this reason, we add the support for netlink_ext_ack in parsing SRv6 behavior attributes. In this way, when an SRv6 behavior attribute is parsed and an error occurs, the kernel can send a message to the userspace describing the error through a meaningful text message in addition to the classic error code. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-09-12 20:16:17 +03:00
struct seg6_local_lwt *slwt,
struct netlink_ext_ack *extack)
seg6: add counters support for SRv6 Behaviors This patch provides counters for SRv6 Behaviors as defined in [1], section 6. For each SRv6 Behavior instance, counters defined in [1] are: - the total number of packets that have been correctly processed; - the total amount of traffic in bytes of all packets that have been correctly processed; In addition, this patch introduces a new counter that counts the number of packets that have NOT been properly processed (i.e. errors) by an SRv6 Behavior instance. Counters are not only interesting for network monitoring purposes (i.e. counting the number of packets processed by a given behavior) but they also provide a simple tool for checking whether a behavior instance is working as we expect or not. Counters can be useful for troubleshooting misconfigured SRv6 networks. Indeed, an SRv6 Behavior can silently drop packets for very different reasons (i.e. wrong SID configuration, interfaces set with SID addresses, etc) without any notification/message to the user. Due to the nature of SRv6 networks, diagnostic tools such as ping and traceroute may be ineffective: paths used for reaching a given router can be totally different from the ones followed by probe packets. In addition, paths are often asymmetrical and this makes it even more difficult to keep up with the journey of the packets and to understand which behaviors are actually processing our traffic. When counters are enabled on an SRv6 Behavior instance, it is possible to verify if packets are actually processed by such behavior and what is the outcome of the processing. Therefore, the counters for SRv6 Behaviors offer an non-invasive observability point which can be leveraged for both traffic monitoring and troubleshooting purposes. [1] https://www.rfc-editor.org/rfc/rfc8986.html#name-counters Troubleshooting using SRv6 Behavior counters -------------------------------------------- Let's make a brief example to see how helpful counters can be for SRv6 networks. Let's consider a node where an SRv6 End Behavior receives an SRv6 packet whose Segment Left (SL) is equal to 0. In this case, the End Behavior (which accepts only packets with SL >= 1) discards the packet and increases the error counter. This information can be leveraged by the network operator for troubleshooting. Indeed, the error counter is telling the user that the packet: (i) arrived at the node; (ii) the packet has been taken into account by the SRv6 End behavior; (iii) but an error has occurred during the processing. The error (iii) could be caused by different reasons, such as wrong route settings on the node or due to an invalid SID List carried by the SRv6 packet. Anyway, the error counter is used to exclude that the packet did not arrive at the node or it has not been processed by the behavior at all. Turning on/off counters for SRv6 Behaviors ------------------------------------------ Each SRv6 Behavior instance can be configured, at the time of its creation, to make use of counters. This is done through iproute2 which allows the user to create an SRv6 Behavior instance specifying the optional "count" attribute as shown in the following example: $ ip -6 route add 2001:db8::1 encap seg6local action End count dev eth0 per-behavior counters can be shown by adding "-s" to the iproute2 command line, i.e.: $ ip -s -6 route show 2001:db8::1 2001:db8::1 encap seg6local action End packets 0 bytes 0 errors 0 dev eth0 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Impact of counters for SRv6 Behaviors on performance ==================================================== To determine the performance impact due to the introduction of counters in the SRv6 Behavior subsystem, we have carried out extensive tests. We chose to test the throughput achieved by the SRv6 End.DX2 Behavior because, among all the other behaviors implemented so far, it reaches the highest throughput which is around 1.5 Mpps (per core at 2.4 GHz on a Xeon(R) CPU E5-2630 v3) on kernel 5.12-rc2 using packets of size ~ 100 bytes. Three different tests were conducted in order to evaluate the overall throughput of the SRv6 End.DX2 Behavior in the following scenarios: 1) vanilla kernel (without the SRv6 Behavior counters patch) and a single instance of an SRv6 End.DX2 Behavior; 2) patched kernel with SRv6 Behavior counters and a single instance of an SRv6 End.DX2 Behavior with counters turned off; 3) patched kernel with SRv6 Behavior counters and a single instance of SRv6 End.DX2 Behavior with counters turned on. All tests were performed on a testbed deployed on the CloudLab facilities [2], a flexible infrastructure dedicated to scientific research on the future of Cloud Computing. Results of tests are shown in the following table: Scenario (1): average 1504764,81 pps (~1504,76 kpps); std. dev 3956,82 pps Scenario (2): average 1501469,78 pps (~1501,47 kpps); std. dev 2979,85 pps Scenario (3): average 1501315,13 pps (~1501,32 kpps); std. dev 2956,00 pps As can be observed, throughputs achieved in scenarios (2),(3) did not suffer any observable degradation compared to scenario (1). Thanks to Jakub Kicinski and David Ahern for their valuable suggestions and comments provided during the discussion of the proposed RFCs. [2] https://www.cloudlab.us Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-04-27 18:44:04 +03:00
{
struct pcpu_seg6_local_counters __percpu *pcounters;
struct nlattr *tb[SEG6_LOCAL_CNT_MAX + 1];
int ret;
ret = nla_parse_nested_deprecated(tb, SEG6_LOCAL_CNT_MAX,
attrs[SEG6_LOCAL_COUNTERS],
seg6_local_counters_policy, NULL);
if (ret < 0)
return ret;
/* basic support for SRv6 Behavior counters requires at least:
* packets, bytes and errors.
*/
if (!tb[SEG6_LOCAL_CNT_PACKETS] || !tb[SEG6_LOCAL_CNT_BYTES] ||
!tb[SEG6_LOCAL_CNT_ERRORS])
return -EINVAL;
/* counters are always zero initialized */
pcounters = seg6_local_alloc_pcpu_counters(GFP_KERNEL);
if (!pcounters)
return -ENOMEM;
slwt->pcpu_counters = pcounters;
return 0;
}
static int seg6_local_fill_nla_counters(struct sk_buff *skb,
struct seg6_local_counters *counters)
{
if (nla_put_u64_64bit(skb, SEG6_LOCAL_CNT_PACKETS, counters->packets,
SEG6_LOCAL_CNT_PAD))
return -EMSGSIZE;
if (nla_put_u64_64bit(skb, SEG6_LOCAL_CNT_BYTES, counters->bytes,
SEG6_LOCAL_CNT_PAD))
return -EMSGSIZE;
if (nla_put_u64_64bit(skb, SEG6_LOCAL_CNT_ERRORS, counters->errors,
SEG6_LOCAL_CNT_PAD))
return -EMSGSIZE;
return 0;
}
static int put_nla_counters(struct sk_buff *skb, struct seg6_local_lwt *slwt)
{
struct seg6_local_counters counters = { 0, 0, 0 };
struct nlattr *nest;
int rc, i;
nest = nla_nest_start(skb, SEG6_LOCAL_COUNTERS);
if (!nest)
return -EMSGSIZE;
for_each_possible_cpu(i) {
struct pcpu_seg6_local_counters *pcounters;
u64 packets, bytes, errors;
unsigned int start;
pcounters = per_cpu_ptr(slwt->pcpu_counters, i);
do {
net: Remove the obsolte u64_stats_fetch_*_irq() users (net). Now that the 32bit UP oddity is gone and 32bit uses always a sequence count, there is no need for the fetch_irq() variants anymore. Convert to the regular interface. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-10-26 16:22:15 +03:00
start = u64_stats_fetch_begin(&pcounters->syncp);
seg6: add counters support for SRv6 Behaviors This patch provides counters for SRv6 Behaviors as defined in [1], section 6. For each SRv6 Behavior instance, counters defined in [1] are: - the total number of packets that have been correctly processed; - the total amount of traffic in bytes of all packets that have been correctly processed; In addition, this patch introduces a new counter that counts the number of packets that have NOT been properly processed (i.e. errors) by an SRv6 Behavior instance. Counters are not only interesting for network monitoring purposes (i.e. counting the number of packets processed by a given behavior) but they also provide a simple tool for checking whether a behavior instance is working as we expect or not. Counters can be useful for troubleshooting misconfigured SRv6 networks. Indeed, an SRv6 Behavior can silently drop packets for very different reasons (i.e. wrong SID configuration, interfaces set with SID addresses, etc) without any notification/message to the user. Due to the nature of SRv6 networks, diagnostic tools such as ping and traceroute may be ineffective: paths used for reaching a given router can be totally different from the ones followed by probe packets. In addition, paths are often asymmetrical and this makes it even more difficult to keep up with the journey of the packets and to understand which behaviors are actually processing our traffic. When counters are enabled on an SRv6 Behavior instance, it is possible to verify if packets are actually processed by such behavior and what is the outcome of the processing. Therefore, the counters for SRv6 Behaviors offer an non-invasive observability point which can be leveraged for both traffic monitoring and troubleshooting purposes. [1] https://www.rfc-editor.org/rfc/rfc8986.html#name-counters Troubleshooting using SRv6 Behavior counters -------------------------------------------- Let's make a brief example to see how helpful counters can be for SRv6 networks. Let's consider a node where an SRv6 End Behavior receives an SRv6 packet whose Segment Left (SL) is equal to 0. In this case, the End Behavior (which accepts only packets with SL >= 1) discards the packet and increases the error counter. This information can be leveraged by the network operator for troubleshooting. Indeed, the error counter is telling the user that the packet: (i) arrived at the node; (ii) the packet has been taken into account by the SRv6 End behavior; (iii) but an error has occurred during the processing. The error (iii) could be caused by different reasons, such as wrong route settings on the node or due to an invalid SID List carried by the SRv6 packet. Anyway, the error counter is used to exclude that the packet did not arrive at the node or it has not been processed by the behavior at all. Turning on/off counters for SRv6 Behaviors ------------------------------------------ Each SRv6 Behavior instance can be configured, at the time of its creation, to make use of counters. This is done through iproute2 which allows the user to create an SRv6 Behavior instance specifying the optional "count" attribute as shown in the following example: $ ip -6 route add 2001:db8::1 encap seg6local action End count dev eth0 per-behavior counters can be shown by adding "-s" to the iproute2 command line, i.e.: $ ip -s -6 route show 2001:db8::1 2001:db8::1 encap seg6local action End packets 0 bytes 0 errors 0 dev eth0 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Impact of counters for SRv6 Behaviors on performance ==================================================== To determine the performance impact due to the introduction of counters in the SRv6 Behavior subsystem, we have carried out extensive tests. We chose to test the throughput achieved by the SRv6 End.DX2 Behavior because, among all the other behaviors implemented so far, it reaches the highest throughput which is around 1.5 Mpps (per core at 2.4 GHz on a Xeon(R) CPU E5-2630 v3) on kernel 5.12-rc2 using packets of size ~ 100 bytes. Three different tests were conducted in order to evaluate the overall throughput of the SRv6 End.DX2 Behavior in the following scenarios: 1) vanilla kernel (without the SRv6 Behavior counters patch) and a single instance of an SRv6 End.DX2 Behavior; 2) patched kernel with SRv6 Behavior counters and a single instance of an SRv6 End.DX2 Behavior with counters turned off; 3) patched kernel with SRv6 Behavior counters and a single instance of SRv6 End.DX2 Behavior with counters turned on. All tests were performed on a testbed deployed on the CloudLab facilities [2], a flexible infrastructure dedicated to scientific research on the future of Cloud Computing. Results of tests are shown in the following table: Scenario (1): average 1504764,81 pps (~1504,76 kpps); std. dev 3956,82 pps Scenario (2): average 1501469,78 pps (~1501,47 kpps); std. dev 2979,85 pps Scenario (3): average 1501315,13 pps (~1501,32 kpps); std. dev 2956,00 pps As can be observed, throughputs achieved in scenarios (2),(3) did not suffer any observable degradation compared to scenario (1). Thanks to Jakub Kicinski and David Ahern for their valuable suggestions and comments provided during the discussion of the proposed RFCs. [2] https://www.cloudlab.us Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-04-27 18:44:04 +03:00
packets = u64_stats_read(&pcounters->packets);
bytes = u64_stats_read(&pcounters->bytes);
errors = u64_stats_read(&pcounters->errors);
net: Remove the obsolte u64_stats_fetch_*_irq() users (net). Now that the 32bit UP oddity is gone and 32bit uses always a sequence count, there is no need for the fetch_irq() variants anymore. Convert to the regular interface. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-10-26 16:22:15 +03:00
} while (u64_stats_fetch_retry(&pcounters->syncp, start));
seg6: add counters support for SRv6 Behaviors This patch provides counters for SRv6 Behaviors as defined in [1], section 6. For each SRv6 Behavior instance, counters defined in [1] are: - the total number of packets that have been correctly processed; - the total amount of traffic in bytes of all packets that have been correctly processed; In addition, this patch introduces a new counter that counts the number of packets that have NOT been properly processed (i.e. errors) by an SRv6 Behavior instance. Counters are not only interesting for network monitoring purposes (i.e. counting the number of packets processed by a given behavior) but they also provide a simple tool for checking whether a behavior instance is working as we expect or not. Counters can be useful for troubleshooting misconfigured SRv6 networks. Indeed, an SRv6 Behavior can silently drop packets for very different reasons (i.e. wrong SID configuration, interfaces set with SID addresses, etc) without any notification/message to the user. Due to the nature of SRv6 networks, diagnostic tools such as ping and traceroute may be ineffective: paths used for reaching a given router can be totally different from the ones followed by probe packets. In addition, paths are often asymmetrical and this makes it even more difficult to keep up with the journey of the packets and to understand which behaviors are actually processing our traffic. When counters are enabled on an SRv6 Behavior instance, it is possible to verify if packets are actually processed by such behavior and what is the outcome of the processing. Therefore, the counters for SRv6 Behaviors offer an non-invasive observability point which can be leveraged for both traffic monitoring and troubleshooting purposes. [1] https://www.rfc-editor.org/rfc/rfc8986.html#name-counters Troubleshooting using SRv6 Behavior counters -------------------------------------------- Let's make a brief example to see how helpful counters can be for SRv6 networks. Let's consider a node where an SRv6 End Behavior receives an SRv6 packet whose Segment Left (SL) is equal to 0. In this case, the End Behavior (which accepts only packets with SL >= 1) discards the packet and increases the error counter. This information can be leveraged by the network operator for troubleshooting. Indeed, the error counter is telling the user that the packet: (i) arrived at the node; (ii) the packet has been taken into account by the SRv6 End behavior; (iii) but an error has occurred during the processing. The error (iii) could be caused by different reasons, such as wrong route settings on the node or due to an invalid SID List carried by the SRv6 packet. Anyway, the error counter is used to exclude that the packet did not arrive at the node or it has not been processed by the behavior at all. Turning on/off counters for SRv6 Behaviors ------------------------------------------ Each SRv6 Behavior instance can be configured, at the time of its creation, to make use of counters. This is done through iproute2 which allows the user to create an SRv6 Behavior instance specifying the optional "count" attribute as shown in the following example: $ ip -6 route add 2001:db8::1 encap seg6local action End count dev eth0 per-behavior counters can be shown by adding "-s" to the iproute2 command line, i.e.: $ ip -s -6 route show 2001:db8::1 2001:db8::1 encap seg6local action End packets 0 bytes 0 errors 0 dev eth0 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Impact of counters for SRv6 Behaviors on performance ==================================================== To determine the performance impact due to the introduction of counters in the SRv6 Behavior subsystem, we have carried out extensive tests. We chose to test the throughput achieved by the SRv6 End.DX2 Behavior because, among all the other behaviors implemented so far, it reaches the highest throughput which is around 1.5 Mpps (per core at 2.4 GHz on a Xeon(R) CPU E5-2630 v3) on kernel 5.12-rc2 using packets of size ~ 100 bytes. Three different tests were conducted in order to evaluate the overall throughput of the SRv6 End.DX2 Behavior in the following scenarios: 1) vanilla kernel (without the SRv6 Behavior counters patch) and a single instance of an SRv6 End.DX2 Behavior; 2) patched kernel with SRv6 Behavior counters and a single instance of an SRv6 End.DX2 Behavior with counters turned off; 3) patched kernel with SRv6 Behavior counters and a single instance of SRv6 End.DX2 Behavior with counters turned on. All tests were performed on a testbed deployed on the CloudLab facilities [2], a flexible infrastructure dedicated to scientific research on the future of Cloud Computing. Results of tests are shown in the following table: Scenario (1): average 1504764,81 pps (~1504,76 kpps); std. dev 3956,82 pps Scenario (2): average 1501469,78 pps (~1501,47 kpps); std. dev 2979,85 pps Scenario (3): average 1501315,13 pps (~1501,32 kpps); std. dev 2956,00 pps As can be observed, throughputs achieved in scenarios (2),(3) did not suffer any observable degradation compared to scenario (1). Thanks to Jakub Kicinski and David Ahern for their valuable suggestions and comments provided during the discussion of the proposed RFCs. [2] https://www.cloudlab.us Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-04-27 18:44:04 +03:00
counters.packets += packets;
counters.bytes += bytes;
counters.errors += errors;
}
rc = seg6_local_fill_nla_counters(skb, &counters);
if (rc < 0) {
nla_nest_cancel(skb, nest);
return rc;
}
return nla_nest_end(skb, nest);
}
static int cmp_nla_counters(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
{
/* a and b are equal if both have pcpu_counters set or not */
return (!!((unsigned long)a->pcpu_counters)) ^
(!!((unsigned long)b->pcpu_counters));
}
static void destroy_attr_counters(struct seg6_local_lwt *slwt)
{
free_percpu(slwt->pcpu_counters);
}
seg6: add NEXT-C-SID support for SRv6 End behavior The NEXT-C-SID mechanism described in [1] offers the possibility of encoding several SRv6 segments within a single 128 bit SID address. Such a SID address is called a Compressed SID (C-SID) container. In this way, the length of the SID List can be drastically reduced. A SID instantiated with the NEXT-C-SID flavor considers an IPv6 address logically structured in three main blocks: i) Locator-Block; ii) Locator-Node Function; iii) Argument. C-SID container +------------------------------------------------------------------+ | Locator-Block |Loc-Node| Argument | | |Function| | +------------------------------------------------------------------+ <--------- B -----------> <- NF -> <------------- A ---------------> (i) The Locator-Block can be any IPv6 prefix available to the provider; (ii) The Locator-Node Function represents the node and the function to be triggered when a packet is received on the node; (iii) The Argument carries the remaining C-SIDs in the current C-SID container. The NEXT-C-SID mechanism relies on the "flavors" framework defined in [2]. The flavors represent additional operations that can modify or extend a subset of the existing behaviors. This patch introduces the support for flavors in SRv6 End behavior implementing the NEXT-C-SID one. An SRv6 End behavior with NEXT-C-SID flavor works as an End behavior but it is capable of processing the compressed SID List encoded in C-SID containers. An SRv6 End behavior with NEXT-C-SID flavor can be configured to support user-provided Locator-Block and Locator-Node Function lengths. In this implementation, such lengths must be evenly divisible by 8 (i.e. must be byte-aligned), otherwise the kernel informs the user about invalid values with a meaningful error code and message through netlink_ext_ack. If Locator-Block and/or Locator-Node Function lengths are not provided by the user during configuration of an SRv6 End behavior instance with NEXT-C-SID flavor, the kernel will choose their default values i.e., 32-bit Locator-Block and 16-bit Locator-Node Function. [1] - https://datatracker.ietf.org/doc/html/draft-ietf-spring-srv6-srh-compression [2] - https://datatracker.ietf.org/doc/html/rfc8986 Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-09-12 20:16:18 +03:00
static const
struct nla_policy seg6_local_flavors_policy[SEG6_LOCAL_FLV_MAX + 1] = {
[SEG6_LOCAL_FLV_OPERATION] = { .type = NLA_U32 },
[SEG6_LOCAL_FLV_LCBLOCK_BITS] = { .type = NLA_U8 },
[SEG6_LOCAL_FLV_LCNODE_FN_BITS] = { .type = NLA_U8 },
};
/* check whether the lengths of the Locator-Block and Locator-Node Function
* are compatible with the dimension of a C-SID container.
*/
static int seg6_chk_next_csid_cfg(__u8 block_len, __u8 func_len)
{
/* Locator-Block and Locator-Node Function cannot exceed 128 bits
* (i.e. C-SID container lenghts).
*/
if (next_csid_chk_cntr_bits(block_len, func_len))
return -EINVAL;
/* Locator-Block length must be greater than zero and evenly divisible
* by 8. There must be room for a Locator-Node Function, at least.
*/
if (next_csid_chk_lcblock_bits(block_len))
return -EINVAL;
/* Locator-Node Function length must be greater than zero and evenly
* divisible by 8. There must be room for the Locator-Block.
*/
if (next_csid_chk_lcnode_fn_bits(func_len))
return -EINVAL;
return 0;
}
static int seg6_parse_nla_next_csid_cfg(struct nlattr **tb,
struct seg6_flavors_info *finfo,
struct netlink_ext_ack *extack)
{
__u8 func_len = SEG6_LOCAL_LCNODE_FN_DBITS;
__u8 block_len = SEG6_LOCAL_LCBLOCK_DBITS;
int rc;
if (tb[SEG6_LOCAL_FLV_LCBLOCK_BITS])
block_len = nla_get_u8(tb[SEG6_LOCAL_FLV_LCBLOCK_BITS]);
if (tb[SEG6_LOCAL_FLV_LCNODE_FN_BITS])
func_len = nla_get_u8(tb[SEG6_LOCAL_FLV_LCNODE_FN_BITS]);
rc = seg6_chk_next_csid_cfg(block_len, func_len);
if (rc < 0) {
NL_SET_ERR_MSG(extack,
"Invalid Locator Block/Node Function lengths");
return rc;
}
finfo->lcblock_bits = block_len;
finfo->lcnode_func_bits = func_len;
return 0;
}
static int parse_nla_flavors(struct nlattr **attrs, struct seg6_local_lwt *slwt,
struct netlink_ext_ack *extack)
{
struct seg6_flavors_info *finfo = &slwt->flv_info;
struct nlattr *tb[SEG6_LOCAL_FLV_MAX + 1];
unsigned long fops;
int rc;
rc = nla_parse_nested_deprecated(tb, SEG6_LOCAL_FLV_MAX,
attrs[SEG6_LOCAL_FLAVORS],
seg6_local_flavors_policy, NULL);
if (rc < 0)
return rc;
/* this attribute MUST always be present since it represents the Flavor
* operation(s) to be carried out.
*/
if (!tb[SEG6_LOCAL_FLV_OPERATION])
return -EINVAL;
fops = nla_get_u32(tb[SEG6_LOCAL_FLV_OPERATION]);
if (fops & ~SEG6_LOCAL_FLV_SUPP_OPS) {
NL_SET_ERR_MSG(extack, "Unsupported Flavor operation(s)");
return -EOPNOTSUPP;
}
finfo->flv_ops = fops;
if (seg6_next_csid_enabled(fops)) {
/* Locator-Block and Locator-Node Function lengths can be
* provided by the user space. Otherwise, default values are
* applied.
*/
rc = seg6_parse_nla_next_csid_cfg(tb, finfo, extack);
if (rc < 0)
return rc;
}
return 0;
}
static int seg6_fill_nla_next_csid_cfg(struct sk_buff *skb,
struct seg6_flavors_info *finfo)
{
if (nla_put_u8(skb, SEG6_LOCAL_FLV_LCBLOCK_BITS, finfo->lcblock_bits))
return -EMSGSIZE;
if (nla_put_u8(skb, SEG6_LOCAL_FLV_LCNODE_FN_BITS,
finfo->lcnode_func_bits))
return -EMSGSIZE;
return 0;
}
static int put_nla_flavors(struct sk_buff *skb, struct seg6_local_lwt *slwt)
{
struct seg6_flavors_info *finfo = &slwt->flv_info;
__u32 fops = finfo->flv_ops;
struct nlattr *nest;
int rc;
nest = nla_nest_start(skb, SEG6_LOCAL_FLAVORS);
if (!nest)
return -EMSGSIZE;
if (nla_put_u32(skb, SEG6_LOCAL_FLV_OPERATION, fops)) {
rc = -EMSGSIZE;
goto err;
}
if (seg6_next_csid_enabled(fops)) {
rc = seg6_fill_nla_next_csid_cfg(skb, finfo);
if (rc < 0)
goto err;
}
return nla_nest_end(skb, nest);
err:
nla_nest_cancel(skb, nest);
return rc;
}
static int seg6_cmp_nla_next_csid_cfg(struct seg6_flavors_info *finfo_a,
struct seg6_flavors_info *finfo_b)
{
if (finfo_a->lcblock_bits != finfo_b->lcblock_bits)
return 1;
if (finfo_a->lcnode_func_bits != finfo_b->lcnode_func_bits)
return 1;
return 0;
}
static int cmp_nla_flavors(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
{
struct seg6_flavors_info *finfo_a = &a->flv_info;
struct seg6_flavors_info *finfo_b = &b->flv_info;
if (finfo_a->flv_ops != finfo_b->flv_ops)
return 1;
if (seg6_next_csid_enabled(finfo_a->flv_ops)) {
if (seg6_cmp_nla_next_csid_cfg(finfo_a, finfo_b))
return 1;
}
return 0;
}
static int encap_size_flavors(struct seg6_local_lwt *slwt)
{
struct seg6_flavors_info *finfo = &slwt->flv_info;
int nlsize;
nlsize = nla_total_size(0) + /* nest SEG6_LOCAL_FLAVORS */
nla_total_size(4); /* SEG6_LOCAL_FLV_OPERATION */
if (seg6_next_csid_enabled(finfo->flv_ops))
nlsize += nla_total_size(1) + /* SEG6_LOCAL_FLV_LCBLOCK_BITS */
nla_total_size(1); /* SEG6_LOCAL_FLV_LCNODE_FN_BITS */
return nlsize;
}
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:26 +03:00
struct seg6_action_param {
seg6: add netlink_ext_ack support in parsing SRv6 behavior attributes An SRv6 behavior instance can be set up using mandatory and/or optional attributes. In the setup phase, each supplied attribute is parsed and processed. If the parsing operation fails, the creation of the behavior instance stops and an error number/code is reported to the user. In many cases, it is challenging for the user to figure out exactly what happened by relying only on the error code. For this reason, we add the support for netlink_ext_ack in parsing SRv6 behavior attributes. In this way, when an SRv6 behavior attribute is parsed and an error occurs, the kernel can send a message to the userspace describing the error through a meaningful text message in addition to the classic error code. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-09-12 20:16:17 +03:00
int (*parse)(struct nlattr **attrs, struct seg6_local_lwt *slwt,
struct netlink_ext_ack *extack);
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:26 +03:00
int (*put)(struct sk_buff *skb, struct seg6_local_lwt *slwt);
int (*cmp)(struct seg6_local_lwt *a, struct seg6_local_lwt *b);
seg6: improve management of behavior attributes Depending on the attribute (i.e.: SEG6_LOCAL_SRH, SEG6_LOCAL_TABLE, etc), the parse() callback performs some validity checks on the provided input and updates the tunnel state (slwt) with the result of the parsing operation. However, an attribute may also need to reserve some additional resources (i.e.: memory or setting up an eBPF program) in the parse() callback to complete the parsing operation. The parse() callbacks are invoked by the parse_nla_action() for each attribute belonging to a specific behavior. Given a behavior with N attributes, if the parsing of the i-th attribute fails, the parse_nla_action() returns immediately with an error. Nonetheless, the resources acquired during the parsing of the i-1 attributes are not freed by the parse_nla_action(). Attributes which acquire resources must release them *in an explicit way* in both the seg6_local_{build/destroy}_state(). However, adding a new attribute of this type requires changes to seg6_local_{build/destroy}_state() to release the resources correctly. The seg6local infrastructure still lacks a simple and structured way to release the resources acquired in the parse() operations. We introduced a new callback in the struct seg6_action_param named destroy(). This callback releases any resource which may have been acquired in the parse() counterpart. Each attribute may or may not implement the destroy() callback depending on whether it needs to free some acquired resources. The destroy() callback comes with several of advantages: 1) we can have many attributes as we want for a given behavior with no need to explicitly free the taken resources; 2) As in case of the seg6_local_build_state(), the seg6_local_destroy_state() does not need to handle the release of resources directly. Indeed, it calls the destroy_attrs() function which is in charge of calling the destroy() callback for every set attribute. We do not need to patch seg6_local_{build/destroy}_state() anymore as we add new attributes; 3) the code is more readable and better structured. Indeed, all the information needed to handle a given attribute are contained in only one place; 4) it facilitates the integration with new features introduced in further patches. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:11 +03:00
/* optional destroy() callback useful for releasing resources which
* have been previously acquired in the corresponding parse()
* function.
*/
void (*destroy)(struct seg6_local_lwt *slwt);
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:26 +03:00
};
static struct seg6_action_param seg6_action_params[SEG6_LOCAL_MAX + 1] = {
ipv6: sr: add rtnetlink functions for seg6local action parameters This patch adds the necessary functions to parse, fill, and compare seg6local rtnetlink attributes, for all defined action parameters. - The SRH parameter defines an SRH to be inserted or encapsulated. - The TABLE parameter defines the table to use for the route lookup of the next segment or the inner decapsulated packet. - The NH4 parameter defines the IPv4 next-hop for an inner decapsulated IPv4 packet. - The NH6 parameter defines the IPv6 next-hop for the next segment or for an inner decapsulated IPv6 packet - The IIF parameter defines an ingress interface index. - The OIF parameter defines an egress interface index. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:27 +03:00
[SEG6_LOCAL_SRH] = { .parse = parse_nla_srh,
.put = put_nla_srh,
seg6: improve management of behavior attributes Depending on the attribute (i.e.: SEG6_LOCAL_SRH, SEG6_LOCAL_TABLE, etc), the parse() callback performs some validity checks on the provided input and updates the tunnel state (slwt) with the result of the parsing operation. However, an attribute may also need to reserve some additional resources (i.e.: memory or setting up an eBPF program) in the parse() callback to complete the parsing operation. The parse() callbacks are invoked by the parse_nla_action() for each attribute belonging to a specific behavior. Given a behavior with N attributes, if the parsing of the i-th attribute fails, the parse_nla_action() returns immediately with an error. Nonetheless, the resources acquired during the parsing of the i-1 attributes are not freed by the parse_nla_action(). Attributes which acquire resources must release them *in an explicit way* in both the seg6_local_{build/destroy}_state(). However, adding a new attribute of this type requires changes to seg6_local_{build/destroy}_state() to release the resources correctly. The seg6local infrastructure still lacks a simple and structured way to release the resources acquired in the parse() operations. We introduced a new callback in the struct seg6_action_param named destroy(). This callback releases any resource which may have been acquired in the parse() counterpart. Each attribute may or may not implement the destroy() callback depending on whether it needs to free some acquired resources. The destroy() callback comes with several of advantages: 1) we can have many attributes as we want for a given behavior with no need to explicitly free the taken resources; 2) As in case of the seg6_local_build_state(), the seg6_local_destroy_state() does not need to handle the release of resources directly. Indeed, it calls the destroy_attrs() function which is in charge of calling the destroy() callback for every set attribute. We do not need to patch seg6_local_{build/destroy}_state() anymore as we add new attributes; 3) the code is more readable and better structured. Indeed, all the information needed to handle a given attribute are contained in only one place; 4) it facilitates the integration with new features introduced in further patches. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:11 +03:00
.cmp = cmp_nla_srh,
.destroy = destroy_attr_srh },
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:26 +03:00
ipv6: sr: add rtnetlink functions for seg6local action parameters This patch adds the necessary functions to parse, fill, and compare seg6local rtnetlink attributes, for all defined action parameters. - The SRH parameter defines an SRH to be inserted or encapsulated. - The TABLE parameter defines the table to use for the route lookup of the next segment or the inner decapsulated packet. - The NH4 parameter defines the IPv4 next-hop for an inner decapsulated IPv4 packet. - The NH6 parameter defines the IPv6 next-hop for the next segment or for an inner decapsulated IPv6 packet - The IIF parameter defines an ingress interface index. - The OIF parameter defines an egress interface index. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:27 +03:00
[SEG6_LOCAL_TABLE] = { .parse = parse_nla_table,
.put = put_nla_table,
.cmp = cmp_nla_table },
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:26 +03:00
ipv6: sr: add rtnetlink functions for seg6local action parameters This patch adds the necessary functions to parse, fill, and compare seg6local rtnetlink attributes, for all defined action parameters. - The SRH parameter defines an SRH to be inserted or encapsulated. - The TABLE parameter defines the table to use for the route lookup of the next segment or the inner decapsulated packet. - The NH4 parameter defines the IPv4 next-hop for an inner decapsulated IPv4 packet. - The NH6 parameter defines the IPv6 next-hop for the next segment or for an inner decapsulated IPv6 packet - The IIF parameter defines an ingress interface index. - The OIF parameter defines an egress interface index. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:27 +03:00
[SEG6_LOCAL_NH4] = { .parse = parse_nla_nh4,
.put = put_nla_nh4,
.cmp = cmp_nla_nh4 },
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:26 +03:00
ipv6: sr: add rtnetlink functions for seg6local action parameters This patch adds the necessary functions to parse, fill, and compare seg6local rtnetlink attributes, for all defined action parameters. - The SRH parameter defines an SRH to be inserted or encapsulated. - The TABLE parameter defines the table to use for the route lookup of the next segment or the inner decapsulated packet. - The NH4 parameter defines the IPv4 next-hop for an inner decapsulated IPv4 packet. - The NH6 parameter defines the IPv6 next-hop for the next segment or for an inner decapsulated IPv6 packet - The IIF parameter defines an ingress interface index. - The OIF parameter defines an egress interface index. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:27 +03:00
[SEG6_LOCAL_NH6] = { .parse = parse_nla_nh6,
.put = put_nla_nh6,
.cmp = cmp_nla_nh6 },
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:26 +03:00
ipv6: sr: add rtnetlink functions for seg6local action parameters This patch adds the necessary functions to parse, fill, and compare seg6local rtnetlink attributes, for all defined action parameters. - The SRH parameter defines an SRH to be inserted or encapsulated. - The TABLE parameter defines the table to use for the route lookup of the next segment or the inner decapsulated packet. - The NH4 parameter defines the IPv4 next-hop for an inner decapsulated IPv4 packet. - The NH6 parameter defines the IPv6 next-hop for the next segment or for an inner decapsulated IPv6 packet - The IIF parameter defines an ingress interface index. - The OIF parameter defines an egress interface index. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:27 +03:00
[SEG6_LOCAL_IIF] = { .parse = parse_nla_iif,
.put = put_nla_iif,
.cmp = cmp_nla_iif },
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:26 +03:00
ipv6: sr: add rtnetlink functions for seg6local action parameters This patch adds the necessary functions to parse, fill, and compare seg6local rtnetlink attributes, for all defined action parameters. - The SRH parameter defines an SRH to be inserted or encapsulated. - The TABLE parameter defines the table to use for the route lookup of the next segment or the inner decapsulated packet. - The NH4 parameter defines the IPv4 next-hop for an inner decapsulated IPv4 packet. - The NH6 parameter defines the IPv6 next-hop for the next segment or for an inner decapsulated IPv6 packet - The IIF parameter defines an ingress interface index. - The OIF parameter defines an egress interface index. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:27 +03:00
[SEG6_LOCAL_OIF] = { .parse = parse_nla_oif,
.put = put_nla_oif,
.cmp = cmp_nla_oif },
ipv6: sr: Add seg6local action End.BPF This patch adds the End.BPF action to the LWT seg6local infrastructure. This action works like any other seg6local End action, meaning that an IPv6 header with SRH is needed, whose DA has to be equal to the SID of the action. It will also advance the SRH to the next segment, the BPF program does not have to take care of this. Since the BPF program may not be a source of instability in the kernel, it is important to ensure that the integrity of the packet is maintained before yielding it back to the IPv6 layer. The hook hence keeps track if the SRH has been altered through the helpers, and re-validates its content if needed with seg6_validate_srh. The state kept for validation is stored in a per-CPU buffer. The BPF program is not allowed to directly write into the packet, and only some fields of the SRH can be altered through the helper bpf_lwt_seg6_store_bytes. Performances profiling has shown that the SRH re-validation does not induce a significant overhead. If the altered SRH is deemed as invalid, the packet is dropped. This validation is also done before executing any action through bpf_lwt_seg6_action, and will not be performed again if the SRH is not modified after calling the action. The BPF program may return 3 types of return codes: - BPF_OK: the End.BPF action will look up the next destination through seg6_lookup_nexthop. - BPF_REDIRECT: if an action has been executed through the bpf_lwt_seg6_action helper, the BPF program should return this value, as the skb's destination is already set and the default lookup should not be performed. - BPF_DROP : the packet will be dropped. Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-20 16:58:16 +03:00
[SEG6_LOCAL_BPF] = { .parse = parse_nla_bpf,
.put = put_nla_bpf,
seg6: improve management of behavior attributes Depending on the attribute (i.e.: SEG6_LOCAL_SRH, SEG6_LOCAL_TABLE, etc), the parse() callback performs some validity checks on the provided input and updates the tunnel state (slwt) with the result of the parsing operation. However, an attribute may also need to reserve some additional resources (i.e.: memory or setting up an eBPF program) in the parse() callback to complete the parsing operation. The parse() callbacks are invoked by the parse_nla_action() for each attribute belonging to a specific behavior. Given a behavior with N attributes, if the parsing of the i-th attribute fails, the parse_nla_action() returns immediately with an error. Nonetheless, the resources acquired during the parsing of the i-1 attributes are not freed by the parse_nla_action(). Attributes which acquire resources must release them *in an explicit way* in both the seg6_local_{build/destroy}_state(). However, adding a new attribute of this type requires changes to seg6_local_{build/destroy}_state() to release the resources correctly. The seg6local infrastructure still lacks a simple and structured way to release the resources acquired in the parse() operations. We introduced a new callback in the struct seg6_action_param named destroy(). This callback releases any resource which may have been acquired in the parse() counterpart. Each attribute may or may not implement the destroy() callback depending on whether it needs to free some acquired resources. The destroy() callback comes with several of advantages: 1) we can have many attributes as we want for a given behavior with no need to explicitly free the taken resources; 2) As in case of the seg6_local_build_state(), the seg6_local_destroy_state() does not need to handle the release of resources directly. Indeed, it calls the destroy_attrs() function which is in charge of calling the destroy() callback for every set attribute. We do not need to patch seg6_local_{build/destroy}_state() anymore as we add new attributes; 3) the code is more readable and better structured. Indeed, all the information needed to handle a given attribute are contained in only one place; 4) it facilitates the integration with new features introduced in further patches. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:11 +03:00
.cmp = cmp_nla_bpf,
.destroy = destroy_attr_bpf },
ipv6: sr: Add seg6local action End.BPF This patch adds the End.BPF action to the LWT seg6local infrastructure. This action works like any other seg6local End action, meaning that an IPv6 header with SRH is needed, whose DA has to be equal to the SID of the action. It will also advance the SRH to the next segment, the BPF program does not have to take care of this. Since the BPF program may not be a source of instability in the kernel, it is important to ensure that the integrity of the packet is maintained before yielding it back to the IPv6 layer. The hook hence keeps track if the SRH has been altered through the helpers, and re-validates its content if needed with seg6_validate_srh. The state kept for validation is stored in a per-CPU buffer. The BPF program is not allowed to directly write into the packet, and only some fields of the SRH can be altered through the helper bpf_lwt_seg6_store_bytes. Performances profiling has shown that the SRH re-validation does not induce a significant overhead. If the altered SRH is deemed as invalid, the packet is dropped. This validation is also done before executing any action through bpf_lwt_seg6_action, and will not be performed again if the SRH is not modified after calling the action. The BPF program may return 3 types of return codes: - BPF_OK: the End.BPF action will look up the next destination through seg6_lookup_nexthop. - BPF_REDIRECT: if an action has been executed through the bpf_lwt_seg6_action helper, the BPF program should return this value, as the skb's destination is already set and the default lookup should not be performed. - BPF_DROP : the packet will be dropped. Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-20 16:58:16 +03:00
seg6: add support for the SRv6 End.DT4 behavior SRv6 End.DT4 is defined in the SRv6 Network Programming [1]. The SRv6 End.DT4 is used to implement IPv4 L3VPN use-cases in multi-tenants environments. It decapsulates the received packets and it performs IPv4 routing lookup in the routing table of the tenant. The SRv6 End.DT4 Linux implementation leverages a VRF device in order to force the routing lookup into the associated routing table. To make the End.DT4 work properly, it must be guaranteed that the routing table used for routing lookup operations is bound to one and only one VRF during the tunnel creation. Such constraint has to be enforced by enabling the VRF strict_mode sysctl parameter, i.e: $ sysctl -wq net.vrf.strict_mode=1. At JANOG44, LINE corporation presented their multi-tenant DC architecture using SRv6 [2]. In the slides, they reported that the Linux kernel is missing the support of SRv6 End.DT4 behavior. The SRv6 End.DT4 behavior can be instantiated using a command similar to the following: $ ip route add 2001:db8::1 encap seg6local action End.DT4 vrftable 100 dev eth0 We introduce the "vrftable" extension in iproute2 in a following patch. [1] https://tools.ietf.org/html/draft-ietf-spring-srv6-network-programming [2] https://speakerdeck.com/line_developers/line-data-center-networking-with-srv6 Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:14 +03:00
[SEG6_LOCAL_VRFTABLE] = { .parse = parse_nla_vrftable,
.put = put_nla_vrftable,
.cmp = cmp_nla_vrftable },
seg6: add counters support for SRv6 Behaviors This patch provides counters for SRv6 Behaviors as defined in [1], section 6. For each SRv6 Behavior instance, counters defined in [1] are: - the total number of packets that have been correctly processed; - the total amount of traffic in bytes of all packets that have been correctly processed; In addition, this patch introduces a new counter that counts the number of packets that have NOT been properly processed (i.e. errors) by an SRv6 Behavior instance. Counters are not only interesting for network monitoring purposes (i.e. counting the number of packets processed by a given behavior) but they also provide a simple tool for checking whether a behavior instance is working as we expect or not. Counters can be useful for troubleshooting misconfigured SRv6 networks. Indeed, an SRv6 Behavior can silently drop packets for very different reasons (i.e. wrong SID configuration, interfaces set with SID addresses, etc) without any notification/message to the user. Due to the nature of SRv6 networks, diagnostic tools such as ping and traceroute may be ineffective: paths used for reaching a given router can be totally different from the ones followed by probe packets. In addition, paths are often asymmetrical and this makes it even more difficult to keep up with the journey of the packets and to understand which behaviors are actually processing our traffic. When counters are enabled on an SRv6 Behavior instance, it is possible to verify if packets are actually processed by such behavior and what is the outcome of the processing. Therefore, the counters for SRv6 Behaviors offer an non-invasive observability point which can be leveraged for both traffic monitoring and troubleshooting purposes. [1] https://www.rfc-editor.org/rfc/rfc8986.html#name-counters Troubleshooting using SRv6 Behavior counters -------------------------------------------- Let's make a brief example to see how helpful counters can be for SRv6 networks. Let's consider a node where an SRv6 End Behavior receives an SRv6 packet whose Segment Left (SL) is equal to 0. In this case, the End Behavior (which accepts only packets with SL >= 1) discards the packet and increases the error counter. This information can be leveraged by the network operator for troubleshooting. Indeed, the error counter is telling the user that the packet: (i) arrived at the node; (ii) the packet has been taken into account by the SRv6 End behavior; (iii) but an error has occurred during the processing. The error (iii) could be caused by different reasons, such as wrong route settings on the node or due to an invalid SID List carried by the SRv6 packet. Anyway, the error counter is used to exclude that the packet did not arrive at the node or it has not been processed by the behavior at all. Turning on/off counters for SRv6 Behaviors ------------------------------------------ Each SRv6 Behavior instance can be configured, at the time of its creation, to make use of counters. This is done through iproute2 which allows the user to create an SRv6 Behavior instance specifying the optional "count" attribute as shown in the following example: $ ip -6 route add 2001:db8::1 encap seg6local action End count dev eth0 per-behavior counters can be shown by adding "-s" to the iproute2 command line, i.e.: $ ip -s -6 route show 2001:db8::1 2001:db8::1 encap seg6local action End packets 0 bytes 0 errors 0 dev eth0 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Impact of counters for SRv6 Behaviors on performance ==================================================== To determine the performance impact due to the introduction of counters in the SRv6 Behavior subsystem, we have carried out extensive tests. We chose to test the throughput achieved by the SRv6 End.DX2 Behavior because, among all the other behaviors implemented so far, it reaches the highest throughput which is around 1.5 Mpps (per core at 2.4 GHz on a Xeon(R) CPU E5-2630 v3) on kernel 5.12-rc2 using packets of size ~ 100 bytes. Three different tests were conducted in order to evaluate the overall throughput of the SRv6 End.DX2 Behavior in the following scenarios: 1) vanilla kernel (without the SRv6 Behavior counters patch) and a single instance of an SRv6 End.DX2 Behavior; 2) patched kernel with SRv6 Behavior counters and a single instance of an SRv6 End.DX2 Behavior with counters turned off; 3) patched kernel with SRv6 Behavior counters and a single instance of SRv6 End.DX2 Behavior with counters turned on. All tests were performed on a testbed deployed on the CloudLab facilities [2], a flexible infrastructure dedicated to scientific research on the future of Cloud Computing. Results of tests are shown in the following table: Scenario (1): average 1504764,81 pps (~1504,76 kpps); std. dev 3956,82 pps Scenario (2): average 1501469,78 pps (~1501,47 kpps); std. dev 2979,85 pps Scenario (3): average 1501315,13 pps (~1501,32 kpps); std. dev 2956,00 pps As can be observed, throughputs achieved in scenarios (2),(3) did not suffer any observable degradation compared to scenario (1). Thanks to Jakub Kicinski and David Ahern for their valuable suggestions and comments provided during the discussion of the proposed RFCs. [2] https://www.cloudlab.us Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-04-27 18:44:04 +03:00
[SEG6_LOCAL_COUNTERS] = { .parse = parse_nla_counters,
.put = put_nla_counters,
.cmp = cmp_nla_counters,
.destroy = destroy_attr_counters },
seg6: add NEXT-C-SID support for SRv6 End behavior The NEXT-C-SID mechanism described in [1] offers the possibility of encoding several SRv6 segments within a single 128 bit SID address. Such a SID address is called a Compressed SID (C-SID) container. In this way, the length of the SID List can be drastically reduced. A SID instantiated with the NEXT-C-SID flavor considers an IPv6 address logically structured in three main blocks: i) Locator-Block; ii) Locator-Node Function; iii) Argument. C-SID container +------------------------------------------------------------------+ | Locator-Block |Loc-Node| Argument | | |Function| | +------------------------------------------------------------------+ <--------- B -----------> <- NF -> <------------- A ---------------> (i) The Locator-Block can be any IPv6 prefix available to the provider; (ii) The Locator-Node Function represents the node and the function to be triggered when a packet is received on the node; (iii) The Argument carries the remaining C-SIDs in the current C-SID container. The NEXT-C-SID mechanism relies on the "flavors" framework defined in [2]. The flavors represent additional operations that can modify or extend a subset of the existing behaviors. This patch introduces the support for flavors in SRv6 End behavior implementing the NEXT-C-SID one. An SRv6 End behavior with NEXT-C-SID flavor works as an End behavior but it is capable of processing the compressed SID List encoded in C-SID containers. An SRv6 End behavior with NEXT-C-SID flavor can be configured to support user-provided Locator-Block and Locator-Node Function lengths. In this implementation, such lengths must be evenly divisible by 8 (i.e. must be byte-aligned), otherwise the kernel informs the user about invalid values with a meaningful error code and message through netlink_ext_ack. If Locator-Block and/or Locator-Node Function lengths are not provided by the user during configuration of an SRv6 End behavior instance with NEXT-C-SID flavor, the kernel will choose their default values i.e., 32-bit Locator-Block and 16-bit Locator-Node Function. [1] - https://datatracker.ietf.org/doc/html/draft-ietf-spring-srv6-srh-compression [2] - https://datatracker.ietf.org/doc/html/rfc8986 Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-09-12 20:16:18 +03:00
[SEG6_LOCAL_FLAVORS] = { .parse = parse_nla_flavors,
.put = put_nla_flavors,
.cmp = cmp_nla_flavors },
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:26 +03:00
};
seg6: improve management of behavior attributes Depending on the attribute (i.e.: SEG6_LOCAL_SRH, SEG6_LOCAL_TABLE, etc), the parse() callback performs some validity checks on the provided input and updates the tunnel state (slwt) with the result of the parsing operation. However, an attribute may also need to reserve some additional resources (i.e.: memory or setting up an eBPF program) in the parse() callback to complete the parsing operation. The parse() callbacks are invoked by the parse_nla_action() for each attribute belonging to a specific behavior. Given a behavior with N attributes, if the parsing of the i-th attribute fails, the parse_nla_action() returns immediately with an error. Nonetheless, the resources acquired during the parsing of the i-1 attributes are not freed by the parse_nla_action(). Attributes which acquire resources must release them *in an explicit way* in both the seg6_local_{build/destroy}_state(). However, adding a new attribute of this type requires changes to seg6_local_{build/destroy}_state() to release the resources correctly. The seg6local infrastructure still lacks a simple and structured way to release the resources acquired in the parse() operations. We introduced a new callback in the struct seg6_action_param named destroy(). This callback releases any resource which may have been acquired in the parse() counterpart. Each attribute may or may not implement the destroy() callback depending on whether it needs to free some acquired resources. The destroy() callback comes with several of advantages: 1) we can have many attributes as we want for a given behavior with no need to explicitly free the taken resources; 2) As in case of the seg6_local_build_state(), the seg6_local_destroy_state() does not need to handle the release of resources directly. Indeed, it calls the destroy_attrs() function which is in charge of calling the destroy() callback for every set attribute. We do not need to patch seg6_local_{build/destroy}_state() anymore as we add new attributes; 3) the code is more readable and better structured. Indeed, all the information needed to handle a given attribute are contained in only one place; 4) it facilitates the integration with new features introduced in further patches. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:11 +03:00
/* call the destroy() callback (if available) for each set attribute in
seg6: add support for optional attributes in SRv6 behaviors Before this patch, each SRv6 behavior specifies a set of required attributes that must be provided by the userspace application when such behavior is going to be instantiated. If at least one of the required attributes is not provided, the creation of the behavior fails. The SRv6 behavior framework lacks a way to manage optional attributes. By definition, an optional attribute for a SRv6 behavior consists of an attribute which may or may not be provided by the userspace. Therefore, if an optional attribute is missing (and thus not supplied by the user) the creation of the behavior goes ahead without any issue. This patch explicitly differentiates the required attributes from the optional attributes. In particular, each behavior can declare a set of required attributes and a set of optional ones. The semantic of the required attributes remains *totally* unaffected by this patch. The introduction of the optional attributes does NOT impact on the backward compatibility of the existing SRv6 behaviors. It is essential to note that if an (optional or required) attribute is supplied to a SRv6 behavior which does not expect it, the behavior simply discards such attribute without generating any error or warning. This operating mode remained unchanged both before and after the introduction of the optional attributes extension. The optional attributes are one of the key components used to implement the SRv6 End.DT6 behavior based on the Virtual Routing and Forwarding (VRF) framework. The optional attributes make possible the coexistence of the already existing SRv6 End.DT6 implementation with the new SRv6 End.DT6 VRF-based implementation without breaking any backward compatibility. Further details on the SRv6 End.DT6 behavior (VRF mode) are reported in subsequent patches. From the userspace point of view, the support for optional attributes DO NOT require any changes to the userspace applications, i.e: iproute2 unless new attributes (required or optional) are needed. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:12 +03:00
* @parsed_attrs, starting from the first attribute up to the @max_parsed
* (excluded) attribute.
seg6: improve management of behavior attributes Depending on the attribute (i.e.: SEG6_LOCAL_SRH, SEG6_LOCAL_TABLE, etc), the parse() callback performs some validity checks on the provided input and updates the tunnel state (slwt) with the result of the parsing operation. However, an attribute may also need to reserve some additional resources (i.e.: memory or setting up an eBPF program) in the parse() callback to complete the parsing operation. The parse() callbacks are invoked by the parse_nla_action() for each attribute belonging to a specific behavior. Given a behavior with N attributes, if the parsing of the i-th attribute fails, the parse_nla_action() returns immediately with an error. Nonetheless, the resources acquired during the parsing of the i-1 attributes are not freed by the parse_nla_action(). Attributes which acquire resources must release them *in an explicit way* in both the seg6_local_{build/destroy}_state(). However, adding a new attribute of this type requires changes to seg6_local_{build/destroy}_state() to release the resources correctly. The seg6local infrastructure still lacks a simple and structured way to release the resources acquired in the parse() operations. We introduced a new callback in the struct seg6_action_param named destroy(). This callback releases any resource which may have been acquired in the parse() counterpart. Each attribute may or may not implement the destroy() callback depending on whether it needs to free some acquired resources. The destroy() callback comes with several of advantages: 1) we can have many attributes as we want for a given behavior with no need to explicitly free the taken resources; 2) As in case of the seg6_local_build_state(), the seg6_local_destroy_state() does not need to handle the release of resources directly. Indeed, it calls the destroy_attrs() function which is in charge of calling the destroy() callback for every set attribute. We do not need to patch seg6_local_{build/destroy}_state() anymore as we add new attributes; 3) the code is more readable and better structured. Indeed, all the information needed to handle a given attribute are contained in only one place; 4) it facilitates the integration with new features introduced in further patches. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:11 +03:00
*/
seg6: add support for optional attributes in SRv6 behaviors Before this patch, each SRv6 behavior specifies a set of required attributes that must be provided by the userspace application when such behavior is going to be instantiated. If at least one of the required attributes is not provided, the creation of the behavior fails. The SRv6 behavior framework lacks a way to manage optional attributes. By definition, an optional attribute for a SRv6 behavior consists of an attribute which may or may not be provided by the userspace. Therefore, if an optional attribute is missing (and thus not supplied by the user) the creation of the behavior goes ahead without any issue. This patch explicitly differentiates the required attributes from the optional attributes. In particular, each behavior can declare a set of required attributes and a set of optional ones. The semantic of the required attributes remains *totally* unaffected by this patch. The introduction of the optional attributes does NOT impact on the backward compatibility of the existing SRv6 behaviors. It is essential to note that if an (optional or required) attribute is supplied to a SRv6 behavior which does not expect it, the behavior simply discards such attribute without generating any error or warning. This operating mode remained unchanged both before and after the introduction of the optional attributes extension. The optional attributes are one of the key components used to implement the SRv6 End.DT6 behavior based on the Virtual Routing and Forwarding (VRF) framework. The optional attributes make possible the coexistence of the already existing SRv6 End.DT6 implementation with the new SRv6 End.DT6 VRF-based implementation without breaking any backward compatibility. Further details on the SRv6 End.DT6 behavior (VRF mode) are reported in subsequent patches. From the userspace point of view, the support for optional attributes DO NOT require any changes to the userspace applications, i.e: iproute2 unless new attributes (required or optional) are needed. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:12 +03:00
static void __destroy_attrs(unsigned long parsed_attrs, int max_parsed,
struct seg6_local_lwt *slwt)
seg6: improve management of behavior attributes Depending on the attribute (i.e.: SEG6_LOCAL_SRH, SEG6_LOCAL_TABLE, etc), the parse() callback performs some validity checks on the provided input and updates the tunnel state (slwt) with the result of the parsing operation. However, an attribute may also need to reserve some additional resources (i.e.: memory or setting up an eBPF program) in the parse() callback to complete the parsing operation. The parse() callbacks are invoked by the parse_nla_action() for each attribute belonging to a specific behavior. Given a behavior with N attributes, if the parsing of the i-th attribute fails, the parse_nla_action() returns immediately with an error. Nonetheless, the resources acquired during the parsing of the i-1 attributes are not freed by the parse_nla_action(). Attributes which acquire resources must release them *in an explicit way* in both the seg6_local_{build/destroy}_state(). However, adding a new attribute of this type requires changes to seg6_local_{build/destroy}_state() to release the resources correctly. The seg6local infrastructure still lacks a simple and structured way to release the resources acquired in the parse() operations. We introduced a new callback in the struct seg6_action_param named destroy(). This callback releases any resource which may have been acquired in the parse() counterpart. Each attribute may or may not implement the destroy() callback depending on whether it needs to free some acquired resources. The destroy() callback comes with several of advantages: 1) we can have many attributes as we want for a given behavior with no need to explicitly free the taken resources; 2) As in case of the seg6_local_build_state(), the seg6_local_destroy_state() does not need to handle the release of resources directly. Indeed, it calls the destroy_attrs() function which is in charge of calling the destroy() callback for every set attribute. We do not need to patch seg6_local_{build/destroy}_state() anymore as we add new attributes; 3) the code is more readable and better structured. Indeed, all the information needed to handle a given attribute are contained in only one place; 4) it facilitates the integration with new features introduced in further patches. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:11 +03:00
{
struct seg6_action_param *param;
int i;
/* Every required seg6local attribute is identified by an ID which is
* encoded as a flag (i.e: 1 << ID) in the 'attrs' bitmask;
*
seg6: add support for optional attributes in SRv6 behaviors Before this patch, each SRv6 behavior specifies a set of required attributes that must be provided by the userspace application when such behavior is going to be instantiated. If at least one of the required attributes is not provided, the creation of the behavior fails. The SRv6 behavior framework lacks a way to manage optional attributes. By definition, an optional attribute for a SRv6 behavior consists of an attribute which may or may not be provided by the userspace. Therefore, if an optional attribute is missing (and thus not supplied by the user) the creation of the behavior goes ahead without any issue. This patch explicitly differentiates the required attributes from the optional attributes. In particular, each behavior can declare a set of required attributes and a set of optional ones. The semantic of the required attributes remains *totally* unaffected by this patch. The introduction of the optional attributes does NOT impact on the backward compatibility of the existing SRv6 behaviors. It is essential to note that if an (optional or required) attribute is supplied to a SRv6 behavior which does not expect it, the behavior simply discards such attribute without generating any error or warning. This operating mode remained unchanged both before and after the introduction of the optional attributes extension. The optional attributes are one of the key components used to implement the SRv6 End.DT6 behavior based on the Virtual Routing and Forwarding (VRF) framework. The optional attributes make possible the coexistence of the already existing SRv6 End.DT6 implementation with the new SRv6 End.DT6 VRF-based implementation without breaking any backward compatibility. Further details on the SRv6 End.DT6 behavior (VRF mode) are reported in subsequent patches. From the userspace point of view, the support for optional attributes DO NOT require any changes to the userspace applications, i.e: iproute2 unless new attributes (required or optional) are needed. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:12 +03:00
* We scan the 'parsed_attrs' bitmask, starting from the first attribute
seg6: improve management of behavior attributes Depending on the attribute (i.e.: SEG6_LOCAL_SRH, SEG6_LOCAL_TABLE, etc), the parse() callback performs some validity checks on the provided input and updates the tunnel state (slwt) with the result of the parsing operation. However, an attribute may also need to reserve some additional resources (i.e.: memory or setting up an eBPF program) in the parse() callback to complete the parsing operation. The parse() callbacks are invoked by the parse_nla_action() for each attribute belonging to a specific behavior. Given a behavior with N attributes, if the parsing of the i-th attribute fails, the parse_nla_action() returns immediately with an error. Nonetheless, the resources acquired during the parsing of the i-1 attributes are not freed by the parse_nla_action(). Attributes which acquire resources must release them *in an explicit way* in both the seg6_local_{build/destroy}_state(). However, adding a new attribute of this type requires changes to seg6_local_{build/destroy}_state() to release the resources correctly. The seg6local infrastructure still lacks a simple and structured way to release the resources acquired in the parse() operations. We introduced a new callback in the struct seg6_action_param named destroy(). This callback releases any resource which may have been acquired in the parse() counterpart. Each attribute may or may not implement the destroy() callback depending on whether it needs to free some acquired resources. The destroy() callback comes with several of advantages: 1) we can have many attributes as we want for a given behavior with no need to explicitly free the taken resources; 2) As in case of the seg6_local_build_state(), the seg6_local_destroy_state() does not need to handle the release of resources directly. Indeed, it calls the destroy_attrs() function which is in charge of calling the destroy() callback for every set attribute. We do not need to patch seg6_local_{build/destroy}_state() anymore as we add new attributes; 3) the code is more readable and better structured. Indeed, all the information needed to handle a given attribute are contained in only one place; 4) it facilitates the integration with new features introduced in further patches. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:11 +03:00
* up to the @max_parsed (excluded) attribute.
* For each set attribute, we retrieve the corresponding destroy()
* callback. If the callback is not available, then we skip to the next
* attribute; otherwise, we call the destroy() callback.
*/
net: seg6: initialize induction variable to first valid array index Fixes the following warnings observed when building CONFIG_IPV6_SEG6_LWTUNNEL=y with clang: net/ipv6/seg6_local.o: warning: objtool: seg6_local_fill_encap() falls through to next function seg6_local_get_encap_size() net/ipv6/seg6_local.o: warning: objtool: seg6_local_cmp_encap() falls through to next function input_action_end() LLVM can fully unroll loops in seg6_local_get_encap_size() and seg6_local_cmp_encap(). One issue in those loops is that the induction variable is initialized to 0. The loop iterates over members of seg6_action_params, a global array of struct seg6_action_param calling their put() function pointer members. seg6_action_param uses an array initializer to initialize SEG6_LOCAL_SRH and later elements, which is the third enumeration of an anonymous union. The guard `if (attrs & SEG6_F_ATTR(i))` may prevent this from being called at runtime, but it would still be UB for `seg6_action_params[0]->put` to be called; the unrolled loop will make the initial iterations unreachable, which LLVM will later rotate to fallthrough to the next function. Make this more obvious that this cannot happen to the compiler by initializing the loop induction variable to the minimum valid index that seg6_action_params is initialized to. Reported-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Link: https://lore.kernel.org/r/20220802161203.622293-1-ndesaulniers@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-08-02 19:12:03 +03:00
for (i = SEG6_LOCAL_SRH; i < max_parsed; ++i) {
seg6: fool-proof the processing of SRv6 behavior attributes The set of required attributes for a given SRv6 behavior is identified using a bitmap stored in an unsigned long, since the initial design of SRv6 networking in Linux. Recently the same approach has been used for identifying the optional attributes. However, the number of attributes supported by SRv6 behaviors depends on the size of the unsigned long type which changes with the architecture. Indeed, on a 64-bit architecture, an SRv6 behavior can support up to 64 attributes while on a 32-bit architecture it can support at most 32 attributes. To fool-proof the processing of SRv6 behaviors we verify, at compile time, that the set of all supported SRv6 attributes can be encoded into a bitmap stored in an unsigned long. Otherwise, kernel build fails forcing developers to reconsider adding a new attribute or extend the total number of supported attributes by the SRv6 behaviors. Moreover, we replace all patterns (1 << i) with the macro SEG6_F_ATTR(i) in order to address potential overflow issues caused by 32-bit signed arithmetic. Thanks to Colin Ian King for catching the overflow problem, providing a solution and inspiring this patch. Thanks to Jakub Kicinski for his useful suggestions during the design of this patch. v2: - remove the SEG6_LOCAL_MAX_SUPP which is not strictly needed: it can be derived from the unsigned long type. Thanks to David Ahern for pointing it out. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/r/20210206170934.5982-1-andrea.mayer@uniroma2.it Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-02-06 20:09:34 +03:00
if (!(parsed_attrs & SEG6_F_ATTR(i)))
seg6: improve management of behavior attributes Depending on the attribute (i.e.: SEG6_LOCAL_SRH, SEG6_LOCAL_TABLE, etc), the parse() callback performs some validity checks on the provided input and updates the tunnel state (slwt) with the result of the parsing operation. However, an attribute may also need to reserve some additional resources (i.e.: memory or setting up an eBPF program) in the parse() callback to complete the parsing operation. The parse() callbacks are invoked by the parse_nla_action() for each attribute belonging to a specific behavior. Given a behavior with N attributes, if the parsing of the i-th attribute fails, the parse_nla_action() returns immediately with an error. Nonetheless, the resources acquired during the parsing of the i-1 attributes are not freed by the parse_nla_action(). Attributes which acquire resources must release them *in an explicit way* in both the seg6_local_{build/destroy}_state(). However, adding a new attribute of this type requires changes to seg6_local_{build/destroy}_state() to release the resources correctly. The seg6local infrastructure still lacks a simple and structured way to release the resources acquired in the parse() operations. We introduced a new callback in the struct seg6_action_param named destroy(). This callback releases any resource which may have been acquired in the parse() counterpart. Each attribute may or may not implement the destroy() callback depending on whether it needs to free some acquired resources. The destroy() callback comes with several of advantages: 1) we can have many attributes as we want for a given behavior with no need to explicitly free the taken resources; 2) As in case of the seg6_local_build_state(), the seg6_local_destroy_state() does not need to handle the release of resources directly. Indeed, it calls the destroy_attrs() function which is in charge of calling the destroy() callback for every set attribute. We do not need to patch seg6_local_{build/destroy}_state() anymore as we add new attributes; 3) the code is more readable and better structured. Indeed, all the information needed to handle a given attribute are contained in only one place; 4) it facilitates the integration with new features introduced in further patches. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:11 +03:00
continue;
param = &seg6_action_params[i];
if (param->destroy)
param->destroy(slwt);
}
}
/* release all the resources that may have been acquired during parsing
* operations.
*/
static void destroy_attrs(struct seg6_local_lwt *slwt)
{
seg6: add support for optional attributes in SRv6 behaviors Before this patch, each SRv6 behavior specifies a set of required attributes that must be provided by the userspace application when such behavior is going to be instantiated. If at least one of the required attributes is not provided, the creation of the behavior fails. The SRv6 behavior framework lacks a way to manage optional attributes. By definition, an optional attribute for a SRv6 behavior consists of an attribute which may or may not be provided by the userspace. Therefore, if an optional attribute is missing (and thus not supplied by the user) the creation of the behavior goes ahead without any issue. This patch explicitly differentiates the required attributes from the optional attributes. In particular, each behavior can declare a set of required attributes and a set of optional ones. The semantic of the required attributes remains *totally* unaffected by this patch. The introduction of the optional attributes does NOT impact on the backward compatibility of the existing SRv6 behaviors. It is essential to note that if an (optional or required) attribute is supplied to a SRv6 behavior which does not expect it, the behavior simply discards such attribute without generating any error or warning. This operating mode remained unchanged both before and after the introduction of the optional attributes extension. The optional attributes are one of the key components used to implement the SRv6 End.DT6 behavior based on the Virtual Routing and Forwarding (VRF) framework. The optional attributes make possible the coexistence of the already existing SRv6 End.DT6 implementation with the new SRv6 End.DT6 VRF-based implementation without breaking any backward compatibility. Further details on the SRv6 End.DT6 behavior (VRF mode) are reported in subsequent patches. From the userspace point of view, the support for optional attributes DO NOT require any changes to the userspace applications, i.e: iproute2 unless new attributes (required or optional) are needed. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:12 +03:00
unsigned long attrs = slwt->desc->attrs | slwt->parsed_optattrs;
__destroy_attrs(attrs, SEG6_LOCAL_MAX + 1, slwt);
}
static int parse_nla_optional_attrs(struct nlattr **attrs,
seg6: add netlink_ext_ack support in parsing SRv6 behavior attributes An SRv6 behavior instance can be set up using mandatory and/or optional attributes. In the setup phase, each supplied attribute is parsed and processed. If the parsing operation fails, the creation of the behavior instance stops and an error number/code is reported to the user. In many cases, it is challenging for the user to figure out exactly what happened by relying only on the error code. For this reason, we add the support for netlink_ext_ack in parsing SRv6 behavior attributes. In this way, when an SRv6 behavior attribute is parsed and an error occurs, the kernel can send a message to the userspace describing the error through a meaningful text message in addition to the classic error code. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-09-12 20:16:17 +03:00
struct seg6_local_lwt *slwt,
struct netlink_ext_ack *extack)
seg6: add support for optional attributes in SRv6 behaviors Before this patch, each SRv6 behavior specifies a set of required attributes that must be provided by the userspace application when such behavior is going to be instantiated. If at least one of the required attributes is not provided, the creation of the behavior fails. The SRv6 behavior framework lacks a way to manage optional attributes. By definition, an optional attribute for a SRv6 behavior consists of an attribute which may or may not be provided by the userspace. Therefore, if an optional attribute is missing (and thus not supplied by the user) the creation of the behavior goes ahead without any issue. This patch explicitly differentiates the required attributes from the optional attributes. In particular, each behavior can declare a set of required attributes and a set of optional ones. The semantic of the required attributes remains *totally* unaffected by this patch. The introduction of the optional attributes does NOT impact on the backward compatibility of the existing SRv6 behaviors. It is essential to note that if an (optional or required) attribute is supplied to a SRv6 behavior which does not expect it, the behavior simply discards such attribute without generating any error or warning. This operating mode remained unchanged both before and after the introduction of the optional attributes extension. The optional attributes are one of the key components used to implement the SRv6 End.DT6 behavior based on the Virtual Routing and Forwarding (VRF) framework. The optional attributes make possible the coexistence of the already existing SRv6 End.DT6 implementation with the new SRv6 End.DT6 VRF-based implementation without breaking any backward compatibility. Further details on the SRv6 End.DT6 behavior (VRF mode) are reported in subsequent patches. From the userspace point of view, the support for optional attributes DO NOT require any changes to the userspace applications, i.e: iproute2 unless new attributes (required or optional) are needed. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:12 +03:00
{
struct seg6_action_desc *desc = slwt->desc;
unsigned long parsed_optattrs = 0;
struct seg6_action_param *param;
int err, i;
net: seg6: initialize induction variable to first valid array index Fixes the following warnings observed when building CONFIG_IPV6_SEG6_LWTUNNEL=y with clang: net/ipv6/seg6_local.o: warning: objtool: seg6_local_fill_encap() falls through to next function seg6_local_get_encap_size() net/ipv6/seg6_local.o: warning: objtool: seg6_local_cmp_encap() falls through to next function input_action_end() LLVM can fully unroll loops in seg6_local_get_encap_size() and seg6_local_cmp_encap(). One issue in those loops is that the induction variable is initialized to 0. The loop iterates over members of seg6_action_params, a global array of struct seg6_action_param calling their put() function pointer members. seg6_action_param uses an array initializer to initialize SEG6_LOCAL_SRH and later elements, which is the third enumeration of an anonymous union. The guard `if (attrs & SEG6_F_ATTR(i))` may prevent this from being called at runtime, but it would still be UB for `seg6_action_params[0]->put` to be called; the unrolled loop will make the initial iterations unreachable, which LLVM will later rotate to fallthrough to the next function. Make this more obvious that this cannot happen to the compiler by initializing the loop induction variable to the minimum valid index that seg6_action_params is initialized to. Reported-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Link: https://lore.kernel.org/r/20220802161203.622293-1-ndesaulniers@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-08-02 19:12:03 +03:00
for (i = SEG6_LOCAL_SRH; i < SEG6_LOCAL_MAX + 1; ++i) {
seg6: fool-proof the processing of SRv6 behavior attributes The set of required attributes for a given SRv6 behavior is identified using a bitmap stored in an unsigned long, since the initial design of SRv6 networking in Linux. Recently the same approach has been used for identifying the optional attributes. However, the number of attributes supported by SRv6 behaviors depends on the size of the unsigned long type which changes with the architecture. Indeed, on a 64-bit architecture, an SRv6 behavior can support up to 64 attributes while on a 32-bit architecture it can support at most 32 attributes. To fool-proof the processing of SRv6 behaviors we verify, at compile time, that the set of all supported SRv6 attributes can be encoded into a bitmap stored in an unsigned long. Otherwise, kernel build fails forcing developers to reconsider adding a new attribute or extend the total number of supported attributes by the SRv6 behaviors. Moreover, we replace all patterns (1 << i) with the macro SEG6_F_ATTR(i) in order to address potential overflow issues caused by 32-bit signed arithmetic. Thanks to Colin Ian King for catching the overflow problem, providing a solution and inspiring this patch. Thanks to Jakub Kicinski for his useful suggestions during the design of this patch. v2: - remove the SEG6_LOCAL_MAX_SUPP which is not strictly needed: it can be derived from the unsigned long type. Thanks to David Ahern for pointing it out. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/r/20210206170934.5982-1-andrea.mayer@uniroma2.it Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-02-06 20:09:34 +03:00
if (!(desc->optattrs & SEG6_F_ATTR(i)) || !attrs[i])
seg6: add support for optional attributes in SRv6 behaviors Before this patch, each SRv6 behavior specifies a set of required attributes that must be provided by the userspace application when such behavior is going to be instantiated. If at least one of the required attributes is not provided, the creation of the behavior fails. The SRv6 behavior framework lacks a way to manage optional attributes. By definition, an optional attribute for a SRv6 behavior consists of an attribute which may or may not be provided by the userspace. Therefore, if an optional attribute is missing (and thus not supplied by the user) the creation of the behavior goes ahead without any issue. This patch explicitly differentiates the required attributes from the optional attributes. In particular, each behavior can declare a set of required attributes and a set of optional ones. The semantic of the required attributes remains *totally* unaffected by this patch. The introduction of the optional attributes does NOT impact on the backward compatibility of the existing SRv6 behaviors. It is essential to note that if an (optional or required) attribute is supplied to a SRv6 behavior which does not expect it, the behavior simply discards such attribute without generating any error or warning. This operating mode remained unchanged both before and after the introduction of the optional attributes extension. The optional attributes are one of the key components used to implement the SRv6 End.DT6 behavior based on the Virtual Routing and Forwarding (VRF) framework. The optional attributes make possible the coexistence of the already existing SRv6 End.DT6 implementation with the new SRv6 End.DT6 VRF-based implementation without breaking any backward compatibility. Further details on the SRv6 End.DT6 behavior (VRF mode) are reported in subsequent patches. From the userspace point of view, the support for optional attributes DO NOT require any changes to the userspace applications, i.e: iproute2 unless new attributes (required or optional) are needed. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:12 +03:00
continue;
/* once here, the i-th attribute is provided by the
* userspace AND it is identified optional as well.
*/
param = &seg6_action_params[i];
seg6: add netlink_ext_ack support in parsing SRv6 behavior attributes An SRv6 behavior instance can be set up using mandatory and/or optional attributes. In the setup phase, each supplied attribute is parsed and processed. If the parsing operation fails, the creation of the behavior instance stops and an error number/code is reported to the user. In many cases, it is challenging for the user to figure out exactly what happened by relying only on the error code. For this reason, we add the support for netlink_ext_ack in parsing SRv6 behavior attributes. In this way, when an SRv6 behavior attribute is parsed and an error occurs, the kernel can send a message to the userspace describing the error through a meaningful text message in addition to the classic error code. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-09-12 20:16:17 +03:00
err = param->parse(attrs, slwt, extack);
seg6: add support for optional attributes in SRv6 behaviors Before this patch, each SRv6 behavior specifies a set of required attributes that must be provided by the userspace application when such behavior is going to be instantiated. If at least one of the required attributes is not provided, the creation of the behavior fails. The SRv6 behavior framework lacks a way to manage optional attributes. By definition, an optional attribute for a SRv6 behavior consists of an attribute which may or may not be provided by the userspace. Therefore, if an optional attribute is missing (and thus not supplied by the user) the creation of the behavior goes ahead without any issue. This patch explicitly differentiates the required attributes from the optional attributes. In particular, each behavior can declare a set of required attributes and a set of optional ones. The semantic of the required attributes remains *totally* unaffected by this patch. The introduction of the optional attributes does NOT impact on the backward compatibility of the existing SRv6 behaviors. It is essential to note that if an (optional or required) attribute is supplied to a SRv6 behavior which does not expect it, the behavior simply discards such attribute without generating any error or warning. This operating mode remained unchanged both before and after the introduction of the optional attributes extension. The optional attributes are one of the key components used to implement the SRv6 End.DT6 behavior based on the Virtual Routing and Forwarding (VRF) framework. The optional attributes make possible the coexistence of the already existing SRv6 End.DT6 implementation with the new SRv6 End.DT6 VRF-based implementation without breaking any backward compatibility. Further details on the SRv6 End.DT6 behavior (VRF mode) are reported in subsequent patches. From the userspace point of view, the support for optional attributes DO NOT require any changes to the userspace applications, i.e: iproute2 unless new attributes (required or optional) are needed. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:12 +03:00
if (err < 0)
goto parse_optattrs_err;
/* current attribute has been correctly parsed */
seg6: fool-proof the processing of SRv6 behavior attributes The set of required attributes for a given SRv6 behavior is identified using a bitmap stored in an unsigned long, since the initial design of SRv6 networking in Linux. Recently the same approach has been used for identifying the optional attributes. However, the number of attributes supported by SRv6 behaviors depends on the size of the unsigned long type which changes with the architecture. Indeed, on a 64-bit architecture, an SRv6 behavior can support up to 64 attributes while on a 32-bit architecture it can support at most 32 attributes. To fool-proof the processing of SRv6 behaviors we verify, at compile time, that the set of all supported SRv6 attributes can be encoded into a bitmap stored in an unsigned long. Otherwise, kernel build fails forcing developers to reconsider adding a new attribute or extend the total number of supported attributes by the SRv6 behaviors. Moreover, we replace all patterns (1 << i) with the macro SEG6_F_ATTR(i) in order to address potential overflow issues caused by 32-bit signed arithmetic. Thanks to Colin Ian King for catching the overflow problem, providing a solution and inspiring this patch. Thanks to Jakub Kicinski for his useful suggestions during the design of this patch. v2: - remove the SEG6_LOCAL_MAX_SUPP which is not strictly needed: it can be derived from the unsigned long type. Thanks to David Ahern for pointing it out. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/r/20210206170934.5982-1-andrea.mayer@uniroma2.it Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-02-06 20:09:34 +03:00
parsed_optattrs |= SEG6_F_ATTR(i);
seg6: add support for optional attributes in SRv6 behaviors Before this patch, each SRv6 behavior specifies a set of required attributes that must be provided by the userspace application when such behavior is going to be instantiated. If at least one of the required attributes is not provided, the creation of the behavior fails. The SRv6 behavior framework lacks a way to manage optional attributes. By definition, an optional attribute for a SRv6 behavior consists of an attribute which may or may not be provided by the userspace. Therefore, if an optional attribute is missing (and thus not supplied by the user) the creation of the behavior goes ahead without any issue. This patch explicitly differentiates the required attributes from the optional attributes. In particular, each behavior can declare a set of required attributes and a set of optional ones. The semantic of the required attributes remains *totally* unaffected by this patch. The introduction of the optional attributes does NOT impact on the backward compatibility of the existing SRv6 behaviors. It is essential to note that if an (optional or required) attribute is supplied to a SRv6 behavior which does not expect it, the behavior simply discards such attribute without generating any error or warning. This operating mode remained unchanged both before and after the introduction of the optional attributes extension. The optional attributes are one of the key components used to implement the SRv6 End.DT6 behavior based on the Virtual Routing and Forwarding (VRF) framework. The optional attributes make possible the coexistence of the already existing SRv6 End.DT6 implementation with the new SRv6 End.DT6 VRF-based implementation without breaking any backward compatibility. Further details on the SRv6 End.DT6 behavior (VRF mode) are reported in subsequent patches. From the userspace point of view, the support for optional attributes DO NOT require any changes to the userspace applications, i.e: iproute2 unless new attributes (required or optional) are needed. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:12 +03:00
}
/* store in the tunnel state all the optional attributed successfully
* parsed.
*/
slwt->parsed_optattrs = parsed_optattrs;
return 0;
parse_optattrs_err:
__destroy_attrs(parsed_optattrs, i, slwt);
return err;
seg6: improve management of behavior attributes Depending on the attribute (i.e.: SEG6_LOCAL_SRH, SEG6_LOCAL_TABLE, etc), the parse() callback performs some validity checks on the provided input and updates the tunnel state (slwt) with the result of the parsing operation. However, an attribute may also need to reserve some additional resources (i.e.: memory or setting up an eBPF program) in the parse() callback to complete the parsing operation. The parse() callbacks are invoked by the parse_nla_action() for each attribute belonging to a specific behavior. Given a behavior with N attributes, if the parsing of the i-th attribute fails, the parse_nla_action() returns immediately with an error. Nonetheless, the resources acquired during the parsing of the i-1 attributes are not freed by the parse_nla_action(). Attributes which acquire resources must release them *in an explicit way* in both the seg6_local_{build/destroy}_state(). However, adding a new attribute of this type requires changes to seg6_local_{build/destroy}_state() to release the resources correctly. The seg6local infrastructure still lacks a simple and structured way to release the resources acquired in the parse() operations. We introduced a new callback in the struct seg6_action_param named destroy(). This callback releases any resource which may have been acquired in the parse() counterpart. Each attribute may or may not implement the destroy() callback depending on whether it needs to free some acquired resources. The destroy() callback comes with several of advantages: 1) we can have many attributes as we want for a given behavior with no need to explicitly free the taken resources; 2) As in case of the seg6_local_build_state(), the seg6_local_destroy_state() does not need to handle the release of resources directly. Indeed, it calls the destroy_attrs() function which is in charge of calling the destroy() callback for every set attribute. We do not need to patch seg6_local_{build/destroy}_state() anymore as we add new attributes; 3) the code is more readable and better structured. Indeed, all the information needed to handle a given attribute are contained in only one place; 4) it facilitates the integration with new features introduced in further patches. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:11 +03:00
}
seg6: add callbacks for customizing the creation/destruction of a behavior We introduce two callbacks used for customizing the creation/destruction of a SRv6 behavior. Such callbacks are defined in the new struct seg6_local_lwtunnel_ops and hereafter we provide a brief description of them: - build_state(...): used for calling the custom constructor of the behavior during its initialization phase and after all the attributes have been parsed successfully; - destroy_state(...): used for calling the custom destructor of the behavior before it is completely destroyed. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:13 +03:00
/* call the custom constructor of the behavior during its initialization phase
* and after that all its attributes have been parsed successfully.
*/
static int
seg6_local_lwtunnel_build_state(struct seg6_local_lwt *slwt, const void *cfg,
struct netlink_ext_ack *extack)
{
struct seg6_action_desc *desc = slwt->desc;
struct seg6_local_lwtunnel_ops *ops;
ops = &desc->slwt_ops;
if (!ops->build_state)
return 0;
return ops->build_state(slwt, cfg, extack);
}
/* call the custom destructor of the behavior which is invoked before the
* tunnel is going to be destroyed.
*/
static void seg6_local_lwtunnel_destroy_state(struct seg6_local_lwt *slwt)
{
struct seg6_action_desc *desc = slwt->desc;
struct seg6_local_lwtunnel_ops *ops;
ops = &desc->slwt_ops;
if (!ops->destroy_state)
return;
ops->destroy_state(slwt);
}
seg6: add netlink_ext_ack support in parsing SRv6 behavior attributes An SRv6 behavior instance can be set up using mandatory and/or optional attributes. In the setup phase, each supplied attribute is parsed and processed. If the parsing operation fails, the creation of the behavior instance stops and an error number/code is reported to the user. In many cases, it is challenging for the user to figure out exactly what happened by relying only on the error code. For this reason, we add the support for netlink_ext_ack in parsing SRv6 behavior attributes. In this way, when an SRv6 behavior attribute is parsed and an error occurs, the kernel can send a message to the userspace describing the error through a meaningful text message in addition to the classic error code. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-09-12 20:16:17 +03:00
static int parse_nla_action(struct nlattr **attrs, struct seg6_local_lwt *slwt,
struct netlink_ext_ack *extack)
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:26 +03:00
{
struct seg6_action_param *param;
struct seg6_action_desc *desc;
seg6: add support for optional attributes in SRv6 behaviors Before this patch, each SRv6 behavior specifies a set of required attributes that must be provided by the userspace application when such behavior is going to be instantiated. If at least one of the required attributes is not provided, the creation of the behavior fails. The SRv6 behavior framework lacks a way to manage optional attributes. By definition, an optional attribute for a SRv6 behavior consists of an attribute which may or may not be provided by the userspace. Therefore, if an optional attribute is missing (and thus not supplied by the user) the creation of the behavior goes ahead without any issue. This patch explicitly differentiates the required attributes from the optional attributes. In particular, each behavior can declare a set of required attributes and a set of optional ones. The semantic of the required attributes remains *totally* unaffected by this patch. The introduction of the optional attributes does NOT impact on the backward compatibility of the existing SRv6 behaviors. It is essential to note that if an (optional or required) attribute is supplied to a SRv6 behavior which does not expect it, the behavior simply discards such attribute without generating any error or warning. This operating mode remained unchanged both before and after the introduction of the optional attributes extension. The optional attributes are one of the key components used to implement the SRv6 End.DT6 behavior based on the Virtual Routing and Forwarding (VRF) framework. The optional attributes make possible the coexistence of the already existing SRv6 End.DT6 implementation with the new SRv6 End.DT6 VRF-based implementation without breaking any backward compatibility. Further details on the SRv6 End.DT6 behavior (VRF mode) are reported in subsequent patches. From the userspace point of view, the support for optional attributes DO NOT require any changes to the userspace applications, i.e: iproute2 unless new attributes (required or optional) are needed. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:12 +03:00
unsigned long invalid_attrs;
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:26 +03:00
int i, err;
desc = __get_action_desc(slwt->action);
if (!desc)
return -EINVAL;
if (!desc->input)
return -EOPNOTSUPP;
slwt->desc = desc;
slwt->headroom += desc->static_headroom;
seg6: add support for optional attributes in SRv6 behaviors Before this patch, each SRv6 behavior specifies a set of required attributes that must be provided by the userspace application when such behavior is going to be instantiated. If at least one of the required attributes is not provided, the creation of the behavior fails. The SRv6 behavior framework lacks a way to manage optional attributes. By definition, an optional attribute for a SRv6 behavior consists of an attribute which may or may not be provided by the userspace. Therefore, if an optional attribute is missing (and thus not supplied by the user) the creation of the behavior goes ahead without any issue. This patch explicitly differentiates the required attributes from the optional attributes. In particular, each behavior can declare a set of required attributes and a set of optional ones. The semantic of the required attributes remains *totally* unaffected by this patch. The introduction of the optional attributes does NOT impact on the backward compatibility of the existing SRv6 behaviors. It is essential to note that if an (optional or required) attribute is supplied to a SRv6 behavior which does not expect it, the behavior simply discards such attribute without generating any error or warning. This operating mode remained unchanged both before and after the introduction of the optional attributes extension. The optional attributes are one of the key components used to implement the SRv6 End.DT6 behavior based on the Virtual Routing and Forwarding (VRF) framework. The optional attributes make possible the coexistence of the already existing SRv6 End.DT6 implementation with the new SRv6 End.DT6 VRF-based implementation without breaking any backward compatibility. Further details on the SRv6 End.DT6 behavior (VRF mode) are reported in subsequent patches. From the userspace point of view, the support for optional attributes DO NOT require any changes to the userspace applications, i.e: iproute2 unless new attributes (required or optional) are needed. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:12 +03:00
/* Forcing the desc->optattrs *set* and the desc->attrs *set* to be
* disjoined, this allow us to release acquired resources by optional
* attributes and by required attributes independently from each other
net: seg6: trivial fix of a spelling mistake in comment There is a comment spelling mistake "interfarence" -> "interference" in function parse_nla_action(). Fix it. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-04-10 20:46:14 +03:00
* without any interference.
seg6: add support for optional attributes in SRv6 behaviors Before this patch, each SRv6 behavior specifies a set of required attributes that must be provided by the userspace application when such behavior is going to be instantiated. If at least one of the required attributes is not provided, the creation of the behavior fails. The SRv6 behavior framework lacks a way to manage optional attributes. By definition, an optional attribute for a SRv6 behavior consists of an attribute which may or may not be provided by the userspace. Therefore, if an optional attribute is missing (and thus not supplied by the user) the creation of the behavior goes ahead without any issue. This patch explicitly differentiates the required attributes from the optional attributes. In particular, each behavior can declare a set of required attributes and a set of optional ones. The semantic of the required attributes remains *totally* unaffected by this patch. The introduction of the optional attributes does NOT impact on the backward compatibility of the existing SRv6 behaviors. It is essential to note that if an (optional or required) attribute is supplied to a SRv6 behavior which does not expect it, the behavior simply discards such attribute without generating any error or warning. This operating mode remained unchanged both before and after the introduction of the optional attributes extension. The optional attributes are one of the key components used to implement the SRv6 End.DT6 behavior based on the Virtual Routing and Forwarding (VRF) framework. The optional attributes make possible the coexistence of the already existing SRv6 End.DT6 implementation with the new SRv6 End.DT6 VRF-based implementation without breaking any backward compatibility. Further details on the SRv6 End.DT6 behavior (VRF mode) are reported in subsequent patches. From the userspace point of view, the support for optional attributes DO NOT require any changes to the userspace applications, i.e: iproute2 unless new attributes (required or optional) are needed. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:12 +03:00
* In other terms, we are sure that we do not release some the acquired
* resources twice.
*
* Note that if an attribute is configured both as required and as
* optional, it means that the user has messed something up in the
* seg6_action_table. Therefore, this check is required for SRv6
* behaviors to work properly.
*/
invalid_attrs = desc->attrs & desc->optattrs;
if (invalid_attrs) {
WARN_ONCE(1,
"An attribute cannot be both required AND optional");
return -EINVAL;
}
/* parse the required attributes */
net: seg6: initialize induction variable to first valid array index Fixes the following warnings observed when building CONFIG_IPV6_SEG6_LWTUNNEL=y with clang: net/ipv6/seg6_local.o: warning: objtool: seg6_local_fill_encap() falls through to next function seg6_local_get_encap_size() net/ipv6/seg6_local.o: warning: objtool: seg6_local_cmp_encap() falls through to next function input_action_end() LLVM can fully unroll loops in seg6_local_get_encap_size() and seg6_local_cmp_encap(). One issue in those loops is that the induction variable is initialized to 0. The loop iterates over members of seg6_action_params, a global array of struct seg6_action_param calling their put() function pointer members. seg6_action_param uses an array initializer to initialize SEG6_LOCAL_SRH and later elements, which is the third enumeration of an anonymous union. The guard `if (attrs & SEG6_F_ATTR(i))` may prevent this from being called at runtime, but it would still be UB for `seg6_action_params[0]->put` to be called; the unrolled loop will make the initial iterations unreachable, which LLVM will later rotate to fallthrough to the next function. Make this more obvious that this cannot happen to the compiler by initializing the loop induction variable to the minimum valid index that seg6_action_params is initialized to. Reported-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Link: https://lore.kernel.org/r/20220802161203.622293-1-ndesaulniers@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-08-02 19:12:03 +03:00
for (i = SEG6_LOCAL_SRH; i < SEG6_LOCAL_MAX + 1; i++) {
seg6: fool-proof the processing of SRv6 behavior attributes The set of required attributes for a given SRv6 behavior is identified using a bitmap stored in an unsigned long, since the initial design of SRv6 networking in Linux. Recently the same approach has been used for identifying the optional attributes. However, the number of attributes supported by SRv6 behaviors depends on the size of the unsigned long type which changes with the architecture. Indeed, on a 64-bit architecture, an SRv6 behavior can support up to 64 attributes while on a 32-bit architecture it can support at most 32 attributes. To fool-proof the processing of SRv6 behaviors we verify, at compile time, that the set of all supported SRv6 attributes can be encoded into a bitmap stored in an unsigned long. Otherwise, kernel build fails forcing developers to reconsider adding a new attribute or extend the total number of supported attributes by the SRv6 behaviors. Moreover, we replace all patterns (1 << i) with the macro SEG6_F_ATTR(i) in order to address potential overflow issues caused by 32-bit signed arithmetic. Thanks to Colin Ian King for catching the overflow problem, providing a solution and inspiring this patch. Thanks to Jakub Kicinski for his useful suggestions during the design of this patch. v2: - remove the SEG6_LOCAL_MAX_SUPP which is not strictly needed: it can be derived from the unsigned long type. Thanks to David Ahern for pointing it out. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/r/20210206170934.5982-1-andrea.mayer@uniroma2.it Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-02-06 20:09:34 +03:00
if (desc->attrs & SEG6_F_ATTR(i)) {
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:26 +03:00
if (!attrs[i])
return -EINVAL;
param = &seg6_action_params[i];
seg6: add netlink_ext_ack support in parsing SRv6 behavior attributes An SRv6 behavior instance can be set up using mandatory and/or optional attributes. In the setup phase, each supplied attribute is parsed and processed. If the parsing operation fails, the creation of the behavior instance stops and an error number/code is reported to the user. In many cases, it is challenging for the user to figure out exactly what happened by relying only on the error code. For this reason, we add the support for netlink_ext_ack in parsing SRv6 behavior attributes. In this way, when an SRv6 behavior attribute is parsed and an error occurs, the kernel can send a message to the userspace describing the error through a meaningful text message in addition to the classic error code. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-09-12 20:16:17 +03:00
err = param->parse(attrs, slwt, extack);
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:26 +03:00
if (err < 0)
seg6: add support for optional attributes in SRv6 behaviors Before this patch, each SRv6 behavior specifies a set of required attributes that must be provided by the userspace application when such behavior is going to be instantiated. If at least one of the required attributes is not provided, the creation of the behavior fails. The SRv6 behavior framework lacks a way to manage optional attributes. By definition, an optional attribute for a SRv6 behavior consists of an attribute which may or may not be provided by the userspace. Therefore, if an optional attribute is missing (and thus not supplied by the user) the creation of the behavior goes ahead without any issue. This patch explicitly differentiates the required attributes from the optional attributes. In particular, each behavior can declare a set of required attributes and a set of optional ones. The semantic of the required attributes remains *totally* unaffected by this patch. The introduction of the optional attributes does NOT impact on the backward compatibility of the existing SRv6 behaviors. It is essential to note that if an (optional or required) attribute is supplied to a SRv6 behavior which does not expect it, the behavior simply discards such attribute without generating any error or warning. This operating mode remained unchanged both before and after the introduction of the optional attributes extension. The optional attributes are one of the key components used to implement the SRv6 End.DT6 behavior based on the Virtual Routing and Forwarding (VRF) framework. The optional attributes make possible the coexistence of the already existing SRv6 End.DT6 implementation with the new SRv6 End.DT6 VRF-based implementation without breaking any backward compatibility. Further details on the SRv6 End.DT6 behavior (VRF mode) are reported in subsequent patches. From the userspace point of view, the support for optional attributes DO NOT require any changes to the userspace applications, i.e: iproute2 unless new attributes (required or optional) are needed. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:12 +03:00
goto parse_attrs_err;
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:26 +03:00
}
}
seg6: add support for optional attributes in SRv6 behaviors Before this patch, each SRv6 behavior specifies a set of required attributes that must be provided by the userspace application when such behavior is going to be instantiated. If at least one of the required attributes is not provided, the creation of the behavior fails. The SRv6 behavior framework lacks a way to manage optional attributes. By definition, an optional attribute for a SRv6 behavior consists of an attribute which may or may not be provided by the userspace. Therefore, if an optional attribute is missing (and thus not supplied by the user) the creation of the behavior goes ahead without any issue. This patch explicitly differentiates the required attributes from the optional attributes. In particular, each behavior can declare a set of required attributes and a set of optional ones. The semantic of the required attributes remains *totally* unaffected by this patch. The introduction of the optional attributes does NOT impact on the backward compatibility of the existing SRv6 behaviors. It is essential to note that if an (optional or required) attribute is supplied to a SRv6 behavior which does not expect it, the behavior simply discards such attribute without generating any error or warning. This operating mode remained unchanged both before and after the introduction of the optional attributes extension. The optional attributes are one of the key components used to implement the SRv6 End.DT6 behavior based on the Virtual Routing and Forwarding (VRF) framework. The optional attributes make possible the coexistence of the already existing SRv6 End.DT6 implementation with the new SRv6 End.DT6 VRF-based implementation without breaking any backward compatibility. Further details on the SRv6 End.DT6 behavior (VRF mode) are reported in subsequent patches. From the userspace point of view, the support for optional attributes DO NOT require any changes to the userspace applications, i.e: iproute2 unless new attributes (required or optional) are needed. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:12 +03:00
/* parse the optional attributes, if any */
seg6: add netlink_ext_ack support in parsing SRv6 behavior attributes An SRv6 behavior instance can be set up using mandatory and/or optional attributes. In the setup phase, each supplied attribute is parsed and processed. If the parsing operation fails, the creation of the behavior instance stops and an error number/code is reported to the user. In many cases, it is challenging for the user to figure out exactly what happened by relying only on the error code. For this reason, we add the support for netlink_ext_ack in parsing SRv6 behavior attributes. In this way, when an SRv6 behavior attribute is parsed and an error occurs, the kernel can send a message to the userspace describing the error through a meaningful text message in addition to the classic error code. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-09-12 20:16:17 +03:00
err = parse_nla_optional_attrs(attrs, slwt, extack);
seg6: add support for optional attributes in SRv6 behaviors Before this patch, each SRv6 behavior specifies a set of required attributes that must be provided by the userspace application when such behavior is going to be instantiated. If at least one of the required attributes is not provided, the creation of the behavior fails. The SRv6 behavior framework lacks a way to manage optional attributes. By definition, an optional attribute for a SRv6 behavior consists of an attribute which may or may not be provided by the userspace. Therefore, if an optional attribute is missing (and thus not supplied by the user) the creation of the behavior goes ahead without any issue. This patch explicitly differentiates the required attributes from the optional attributes. In particular, each behavior can declare a set of required attributes and a set of optional ones. The semantic of the required attributes remains *totally* unaffected by this patch. The introduction of the optional attributes does NOT impact on the backward compatibility of the existing SRv6 behaviors. It is essential to note that if an (optional or required) attribute is supplied to a SRv6 behavior which does not expect it, the behavior simply discards such attribute without generating any error or warning. This operating mode remained unchanged both before and after the introduction of the optional attributes extension. The optional attributes are one of the key components used to implement the SRv6 End.DT6 behavior based on the Virtual Routing and Forwarding (VRF) framework. The optional attributes make possible the coexistence of the already existing SRv6 End.DT6 implementation with the new SRv6 End.DT6 VRF-based implementation without breaking any backward compatibility. Further details on the SRv6 End.DT6 behavior (VRF mode) are reported in subsequent patches. From the userspace point of view, the support for optional attributes DO NOT require any changes to the userspace applications, i.e: iproute2 unless new attributes (required or optional) are needed. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:12 +03:00
if (err < 0)
goto parse_attrs_err;
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:26 +03:00
return 0;
seg6: improve management of behavior attributes Depending on the attribute (i.e.: SEG6_LOCAL_SRH, SEG6_LOCAL_TABLE, etc), the parse() callback performs some validity checks on the provided input and updates the tunnel state (slwt) with the result of the parsing operation. However, an attribute may also need to reserve some additional resources (i.e.: memory or setting up an eBPF program) in the parse() callback to complete the parsing operation. The parse() callbacks are invoked by the parse_nla_action() for each attribute belonging to a specific behavior. Given a behavior with N attributes, if the parsing of the i-th attribute fails, the parse_nla_action() returns immediately with an error. Nonetheless, the resources acquired during the parsing of the i-1 attributes are not freed by the parse_nla_action(). Attributes which acquire resources must release them *in an explicit way* in both the seg6_local_{build/destroy}_state(). However, adding a new attribute of this type requires changes to seg6_local_{build/destroy}_state() to release the resources correctly. The seg6local infrastructure still lacks a simple and structured way to release the resources acquired in the parse() operations. We introduced a new callback in the struct seg6_action_param named destroy(). This callback releases any resource which may have been acquired in the parse() counterpart. Each attribute may or may not implement the destroy() callback depending on whether it needs to free some acquired resources. The destroy() callback comes with several of advantages: 1) we can have many attributes as we want for a given behavior with no need to explicitly free the taken resources; 2) As in case of the seg6_local_build_state(), the seg6_local_destroy_state() does not need to handle the release of resources directly. Indeed, it calls the destroy_attrs() function which is in charge of calling the destroy() callback for every set attribute. We do not need to patch seg6_local_{build/destroy}_state() anymore as we add new attributes; 3) the code is more readable and better structured. Indeed, all the information needed to handle a given attribute are contained in only one place; 4) it facilitates the integration with new features introduced in further patches. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:11 +03:00
seg6: add support for optional attributes in SRv6 behaviors Before this patch, each SRv6 behavior specifies a set of required attributes that must be provided by the userspace application when such behavior is going to be instantiated. If at least one of the required attributes is not provided, the creation of the behavior fails. The SRv6 behavior framework lacks a way to manage optional attributes. By definition, an optional attribute for a SRv6 behavior consists of an attribute which may or may not be provided by the userspace. Therefore, if an optional attribute is missing (and thus not supplied by the user) the creation of the behavior goes ahead without any issue. This patch explicitly differentiates the required attributes from the optional attributes. In particular, each behavior can declare a set of required attributes and a set of optional ones. The semantic of the required attributes remains *totally* unaffected by this patch. The introduction of the optional attributes does NOT impact on the backward compatibility of the existing SRv6 behaviors. It is essential to note that if an (optional or required) attribute is supplied to a SRv6 behavior which does not expect it, the behavior simply discards such attribute without generating any error or warning. This operating mode remained unchanged both before and after the introduction of the optional attributes extension. The optional attributes are one of the key components used to implement the SRv6 End.DT6 behavior based on the Virtual Routing and Forwarding (VRF) framework. The optional attributes make possible the coexistence of the already existing SRv6 End.DT6 implementation with the new SRv6 End.DT6 VRF-based implementation without breaking any backward compatibility. Further details on the SRv6 End.DT6 behavior (VRF mode) are reported in subsequent patches. From the userspace point of view, the support for optional attributes DO NOT require any changes to the userspace applications, i.e: iproute2 unless new attributes (required or optional) are needed. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:12 +03:00
parse_attrs_err:
seg6: improve management of behavior attributes Depending on the attribute (i.e.: SEG6_LOCAL_SRH, SEG6_LOCAL_TABLE, etc), the parse() callback performs some validity checks on the provided input and updates the tunnel state (slwt) with the result of the parsing operation. However, an attribute may also need to reserve some additional resources (i.e.: memory or setting up an eBPF program) in the parse() callback to complete the parsing operation. The parse() callbacks are invoked by the parse_nla_action() for each attribute belonging to a specific behavior. Given a behavior with N attributes, if the parsing of the i-th attribute fails, the parse_nla_action() returns immediately with an error. Nonetheless, the resources acquired during the parsing of the i-1 attributes are not freed by the parse_nla_action(). Attributes which acquire resources must release them *in an explicit way* in both the seg6_local_{build/destroy}_state(). However, adding a new attribute of this type requires changes to seg6_local_{build/destroy}_state() to release the resources correctly. The seg6local infrastructure still lacks a simple and structured way to release the resources acquired in the parse() operations. We introduced a new callback in the struct seg6_action_param named destroy(). This callback releases any resource which may have been acquired in the parse() counterpart. Each attribute may or may not implement the destroy() callback depending on whether it needs to free some acquired resources. The destroy() callback comes with several of advantages: 1) we can have many attributes as we want for a given behavior with no need to explicitly free the taken resources; 2) As in case of the seg6_local_build_state(), the seg6_local_destroy_state() does not need to handle the release of resources directly. Indeed, it calls the destroy_attrs() function which is in charge of calling the destroy() callback for every set attribute. We do not need to patch seg6_local_{build/destroy}_state() anymore as we add new attributes; 3) the code is more readable and better structured. Indeed, all the information needed to handle a given attribute are contained in only one place; 4) it facilitates the integration with new features introduced in further patches. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:11 +03:00
/* release any resource that may have been acquired during the i-1
* parse() operations.
*/
seg6: add support for optional attributes in SRv6 behaviors Before this patch, each SRv6 behavior specifies a set of required attributes that must be provided by the userspace application when such behavior is going to be instantiated. If at least one of the required attributes is not provided, the creation of the behavior fails. The SRv6 behavior framework lacks a way to manage optional attributes. By definition, an optional attribute for a SRv6 behavior consists of an attribute which may or may not be provided by the userspace. Therefore, if an optional attribute is missing (and thus not supplied by the user) the creation of the behavior goes ahead without any issue. This patch explicitly differentiates the required attributes from the optional attributes. In particular, each behavior can declare a set of required attributes and a set of optional ones. The semantic of the required attributes remains *totally* unaffected by this patch. The introduction of the optional attributes does NOT impact on the backward compatibility of the existing SRv6 behaviors. It is essential to note that if an (optional or required) attribute is supplied to a SRv6 behavior which does not expect it, the behavior simply discards such attribute without generating any error or warning. This operating mode remained unchanged both before and after the introduction of the optional attributes extension. The optional attributes are one of the key components used to implement the SRv6 End.DT6 behavior based on the Virtual Routing and Forwarding (VRF) framework. The optional attributes make possible the coexistence of the already existing SRv6 End.DT6 implementation with the new SRv6 End.DT6 VRF-based implementation without breaking any backward compatibility. Further details on the SRv6 End.DT6 behavior (VRF mode) are reported in subsequent patches. From the userspace point of view, the support for optional attributes DO NOT require any changes to the userspace applications, i.e: iproute2 unless new attributes (required or optional) are needed. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:12 +03:00
__destroy_attrs(desc->attrs, i, slwt);
seg6: improve management of behavior attributes Depending on the attribute (i.e.: SEG6_LOCAL_SRH, SEG6_LOCAL_TABLE, etc), the parse() callback performs some validity checks on the provided input and updates the tunnel state (slwt) with the result of the parsing operation. However, an attribute may also need to reserve some additional resources (i.e.: memory or setting up an eBPF program) in the parse() callback to complete the parsing operation. The parse() callbacks are invoked by the parse_nla_action() for each attribute belonging to a specific behavior. Given a behavior with N attributes, if the parsing of the i-th attribute fails, the parse_nla_action() returns immediately with an error. Nonetheless, the resources acquired during the parsing of the i-1 attributes are not freed by the parse_nla_action(). Attributes which acquire resources must release them *in an explicit way* in both the seg6_local_{build/destroy}_state(). However, adding a new attribute of this type requires changes to seg6_local_{build/destroy}_state() to release the resources correctly. The seg6local infrastructure still lacks a simple and structured way to release the resources acquired in the parse() operations. We introduced a new callback in the struct seg6_action_param named destroy(). This callback releases any resource which may have been acquired in the parse() counterpart. Each attribute may or may not implement the destroy() callback depending on whether it needs to free some acquired resources. The destroy() callback comes with several of advantages: 1) we can have many attributes as we want for a given behavior with no need to explicitly free the taken resources; 2) As in case of the seg6_local_build_state(), the seg6_local_destroy_state() does not need to handle the release of resources directly. Indeed, it calls the destroy_attrs() function which is in charge of calling the destroy() callback for every set attribute. We do not need to patch seg6_local_{build/destroy}_state() anymore as we add new attributes; 3) the code is more readable and better structured. Indeed, all the information needed to handle a given attribute are contained in only one place; 4) it facilitates the integration with new features introduced in further patches. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:11 +03:00
return err;
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:26 +03:00
}
net: add net available in build_state The build_state callback of lwtunnel doesn't contain the net namespace structure yet. This patch will add it so we can check on specific address configuration at creation time of rpl source routes. Signed-off-by: Alexander Aring <alex.aring@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-28 01:00:21 +03:00
static int seg6_local_build_state(struct net *net, struct nlattr *nla,
unsigned int family, const void *cfg,
struct lwtunnel_state **ts,
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:26 +03:00
struct netlink_ext_ack *extack)
{
struct nlattr *tb[SEG6_LOCAL_MAX + 1];
struct lwtunnel_state *newts;
struct seg6_local_lwt *slwt;
int err;
ipv6: sr: enforce IPv6 packets for seg6local lwt This patch ensures that the seg6local lightweight tunnel is used solely with IPv6 routes and processes only IPv6 packets. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 10:56:46 +03:00
if (family != AF_INET6)
return -EINVAL;
netlink: make validation more configurable for future strictness We currently have two levels of strict validation: 1) liberal (default) - undefined (type >= max) & NLA_UNSPEC attributes accepted - attribute length >= expected accepted - garbage at end of message accepted 2) strict (opt-in) - NLA_UNSPEC attributes accepted - attribute length >= expected accepted Split out parsing strictness into four different options: * TRAILING - check that there's no trailing data after parsing attributes (in message or nested) * MAXTYPE - reject attrs > max known type * UNSPEC - reject attributes with NLA_UNSPEC policy entries * STRICT_ATTRS - strictly validate attribute size The default for future things should be *everything*. The current *_strict() is a combination of TRAILING and MAXTYPE, and is renamed to _deprecated_strict(). The current regular parsing has none of this, and is renamed to *_parse_deprecated(). Additionally it allows us to selectively set one of the new flags even on old policies. Notably, the UNSPEC flag could be useful in this case, since it can be arranged (by filling in the policy) to not be an incompatible userspace ABI change, but would then going forward prevent forgetting attribute entries. Similar can apply to the POLICY flag. We end up with the following renames: * nla_parse -> nla_parse_deprecated * nla_parse_strict -> nla_parse_deprecated_strict * nlmsg_parse -> nlmsg_parse_deprecated * nlmsg_parse_strict -> nlmsg_parse_deprecated_strict * nla_parse_nested -> nla_parse_nested_deprecated * nla_validate_nested -> nla_validate_nested_deprecated Using spatch, of course: @@ expression TB, MAX, HEAD, LEN, POL, EXT; @@ -nla_parse(TB, MAX, HEAD, LEN, POL, EXT) +nla_parse_deprecated(TB, MAX, HEAD, LEN, POL, EXT) @@ expression NLH, HDRLEN, TB, MAX, POL, EXT; @@ -nlmsg_parse(NLH, HDRLEN, TB, MAX, POL, EXT) +nlmsg_parse_deprecated(NLH, HDRLEN, TB, MAX, POL, EXT) @@ expression NLH, HDRLEN, TB, MAX, POL, EXT; @@ -nlmsg_parse_strict(NLH, HDRLEN, TB, MAX, POL, EXT) +nlmsg_parse_deprecated_strict(NLH, HDRLEN, TB, MAX, POL, EXT) @@ expression TB, MAX, NLA, POL, EXT; @@ -nla_parse_nested(TB, MAX, NLA, POL, EXT) +nla_parse_nested_deprecated(TB, MAX, NLA, POL, EXT) @@ expression START, MAX, POL, EXT; @@ -nla_validate_nested(START, MAX, POL, EXT) +nla_validate_nested_deprecated(START, MAX, POL, EXT) @@ expression NLH, HDRLEN, MAX, POL, EXT; @@ -nlmsg_validate(NLH, HDRLEN, MAX, POL, EXT) +nlmsg_validate_deprecated(NLH, HDRLEN, MAX, POL, EXT) For this patch, don't actually add the strict, non-renamed versions yet so that it breaks compile if I get it wrong. Also, while at it, make nla_validate and nla_parse go down to a common __nla_validate_parse() function to avoid code duplication. Ultimately, this allows us to have very strict validation for every new caller of nla_parse()/nlmsg_parse() etc as re-introduced in the next patch, while existing things will continue to work as is. In effect then, this adds fully strict validation for any new command. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-26 15:07:28 +03:00
err = nla_parse_nested_deprecated(tb, SEG6_LOCAL_MAX, nla,
seg6_local_policy, extack);
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:26 +03:00
if (err < 0)
return err;
if (!tb[SEG6_LOCAL_ACTION])
return -EINVAL;
newts = lwtunnel_state_alloc(sizeof(*slwt));
if (!newts)
return -ENOMEM;
slwt = seg6_local_lwtunnel(newts);
slwt->action = nla_get_u32(tb[SEG6_LOCAL_ACTION]);
seg6: add netlink_ext_ack support in parsing SRv6 behavior attributes An SRv6 behavior instance can be set up using mandatory and/or optional attributes. In the setup phase, each supplied attribute is parsed and processed. If the parsing operation fails, the creation of the behavior instance stops and an error number/code is reported to the user. In many cases, it is challenging for the user to figure out exactly what happened by relying only on the error code. For this reason, we add the support for netlink_ext_ack in parsing SRv6 behavior attributes. In this way, when an SRv6 behavior attribute is parsed and an error occurs, the kernel can send a message to the userspace describing the error through a meaningful text message in addition to the classic error code. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-09-12 20:16:17 +03:00
err = parse_nla_action(tb, slwt, extack);
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:26 +03:00
if (err < 0)
goto out_free;
seg6: add callbacks for customizing the creation/destruction of a behavior We introduce two callbacks used for customizing the creation/destruction of a SRv6 behavior. Such callbacks are defined in the new struct seg6_local_lwtunnel_ops and hereafter we provide a brief description of them: - build_state(...): used for calling the custom constructor of the behavior during its initialization phase and after all the attributes have been parsed successfully; - destroy_state(...): used for calling the custom destructor of the behavior before it is completely destroyed. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:13 +03:00
err = seg6_local_lwtunnel_build_state(slwt, cfg, extack);
if (err < 0)
goto out_destroy_attrs;
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:26 +03:00
newts->type = LWTUNNEL_ENCAP_SEG6_LOCAL;
newts->flags = LWTUNNEL_STATE_INPUT_REDIRECT;
newts->headroom = slwt->headroom;
*ts = newts;
return 0;
seg6: add callbacks for customizing the creation/destruction of a behavior We introduce two callbacks used for customizing the creation/destruction of a SRv6 behavior. Such callbacks are defined in the new struct seg6_local_lwtunnel_ops and hereafter we provide a brief description of them: - build_state(...): used for calling the custom constructor of the behavior during its initialization phase and after all the attributes have been parsed successfully; - destroy_state(...): used for calling the custom destructor of the behavior before it is completely destroyed. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:13 +03:00
out_destroy_attrs:
destroy_attrs(slwt);
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:26 +03:00
out_free:
kfree(newts);
return err;
}
static void seg6_local_destroy_state(struct lwtunnel_state *lwt)
{
struct seg6_local_lwt *slwt = seg6_local_lwtunnel(lwt);
seg6: add callbacks for customizing the creation/destruction of a behavior We introduce two callbacks used for customizing the creation/destruction of a SRv6 behavior. Such callbacks are defined in the new struct seg6_local_lwtunnel_ops and hereafter we provide a brief description of them: - build_state(...): used for calling the custom constructor of the behavior during its initialization phase and after all the attributes have been parsed successfully; - destroy_state(...): used for calling the custom destructor of the behavior before it is completely destroyed. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:13 +03:00
seg6_local_lwtunnel_destroy_state(slwt);
seg6: improve management of behavior attributes Depending on the attribute (i.e.: SEG6_LOCAL_SRH, SEG6_LOCAL_TABLE, etc), the parse() callback performs some validity checks on the provided input and updates the tunnel state (slwt) with the result of the parsing operation. However, an attribute may also need to reserve some additional resources (i.e.: memory or setting up an eBPF program) in the parse() callback to complete the parsing operation. The parse() callbacks are invoked by the parse_nla_action() for each attribute belonging to a specific behavior. Given a behavior with N attributes, if the parsing of the i-th attribute fails, the parse_nla_action() returns immediately with an error. Nonetheless, the resources acquired during the parsing of the i-1 attributes are not freed by the parse_nla_action(). Attributes which acquire resources must release them *in an explicit way* in both the seg6_local_{build/destroy}_state(). However, adding a new attribute of this type requires changes to seg6_local_{build/destroy}_state() to release the resources correctly. The seg6local infrastructure still lacks a simple and structured way to release the resources acquired in the parse() operations. We introduced a new callback in the struct seg6_action_param named destroy(). This callback releases any resource which may have been acquired in the parse() counterpart. Each attribute may or may not implement the destroy() callback depending on whether it needs to free some acquired resources. The destroy() callback comes with several of advantages: 1) we can have many attributes as we want for a given behavior with no need to explicitly free the taken resources; 2) As in case of the seg6_local_build_state(), the seg6_local_destroy_state() does not need to handle the release of resources directly. Indeed, it calls the destroy_attrs() function which is in charge of calling the destroy() callback for every set attribute. We do not need to patch seg6_local_{build/destroy}_state() anymore as we add new attributes; 3) the code is more readable and better structured. Indeed, all the information needed to handle a given attribute are contained in only one place; 4) it facilitates the integration with new features introduced in further patches. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:11 +03:00
destroy_attrs(slwt);
ipv6: sr: Add seg6local action End.BPF This patch adds the End.BPF action to the LWT seg6local infrastructure. This action works like any other seg6local End action, meaning that an IPv6 header with SRH is needed, whose DA has to be equal to the SID of the action. It will also advance the SRH to the next segment, the BPF program does not have to take care of this. Since the BPF program may not be a source of instability in the kernel, it is important to ensure that the integrity of the packet is maintained before yielding it back to the IPv6 layer. The hook hence keeps track if the SRH has been altered through the helpers, and re-validates its content if needed with seg6_validate_srh. The state kept for validation is stored in a per-CPU buffer. The BPF program is not allowed to directly write into the packet, and only some fields of the SRH can be altered through the helper bpf_lwt_seg6_store_bytes. Performances profiling has shown that the SRH re-validation does not induce a significant overhead. If the altered SRH is deemed as invalid, the packet is dropped. This validation is also done before executing any action through bpf_lwt_seg6_action, and will not be performed again if the SRH is not modified after calling the action. The BPF program may return 3 types of return codes: - BPF_OK: the End.BPF action will look up the next destination through seg6_lookup_nexthop. - BPF_REDIRECT: if an action has been executed through the bpf_lwt_seg6_action helper, the BPF program should return this value, as the skb's destination is already set and the default lookup should not be performed. - BPF_DROP : the packet will be dropped. Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-20 16:58:16 +03:00
return;
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:26 +03:00
}
static int seg6_local_fill_encap(struct sk_buff *skb,
struct lwtunnel_state *lwt)
{
struct seg6_local_lwt *slwt = seg6_local_lwtunnel(lwt);
struct seg6_action_param *param;
seg6: add support for optional attributes in SRv6 behaviors Before this patch, each SRv6 behavior specifies a set of required attributes that must be provided by the userspace application when such behavior is going to be instantiated. If at least one of the required attributes is not provided, the creation of the behavior fails. The SRv6 behavior framework lacks a way to manage optional attributes. By definition, an optional attribute for a SRv6 behavior consists of an attribute which may or may not be provided by the userspace. Therefore, if an optional attribute is missing (and thus not supplied by the user) the creation of the behavior goes ahead without any issue. This patch explicitly differentiates the required attributes from the optional attributes. In particular, each behavior can declare a set of required attributes and a set of optional ones. The semantic of the required attributes remains *totally* unaffected by this patch. The introduction of the optional attributes does NOT impact on the backward compatibility of the existing SRv6 behaviors. It is essential to note that if an (optional or required) attribute is supplied to a SRv6 behavior which does not expect it, the behavior simply discards such attribute without generating any error or warning. This operating mode remained unchanged both before and after the introduction of the optional attributes extension. The optional attributes are one of the key components used to implement the SRv6 End.DT6 behavior based on the Virtual Routing and Forwarding (VRF) framework. The optional attributes make possible the coexistence of the already existing SRv6 End.DT6 implementation with the new SRv6 End.DT6 VRF-based implementation without breaking any backward compatibility. Further details on the SRv6 End.DT6 behavior (VRF mode) are reported in subsequent patches. From the userspace point of view, the support for optional attributes DO NOT require any changes to the userspace applications, i.e: iproute2 unless new attributes (required or optional) are needed. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:12 +03:00
unsigned long attrs;
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:26 +03:00
int i, err;
if (nla_put_u32(skb, SEG6_LOCAL_ACTION, slwt->action))
return -EMSGSIZE;
seg6: add support for optional attributes in SRv6 behaviors Before this patch, each SRv6 behavior specifies a set of required attributes that must be provided by the userspace application when such behavior is going to be instantiated. If at least one of the required attributes is not provided, the creation of the behavior fails. The SRv6 behavior framework lacks a way to manage optional attributes. By definition, an optional attribute for a SRv6 behavior consists of an attribute which may or may not be provided by the userspace. Therefore, if an optional attribute is missing (and thus not supplied by the user) the creation of the behavior goes ahead without any issue. This patch explicitly differentiates the required attributes from the optional attributes. In particular, each behavior can declare a set of required attributes and a set of optional ones. The semantic of the required attributes remains *totally* unaffected by this patch. The introduction of the optional attributes does NOT impact on the backward compatibility of the existing SRv6 behaviors. It is essential to note that if an (optional or required) attribute is supplied to a SRv6 behavior which does not expect it, the behavior simply discards such attribute without generating any error or warning. This operating mode remained unchanged both before and after the introduction of the optional attributes extension. The optional attributes are one of the key components used to implement the SRv6 End.DT6 behavior based on the Virtual Routing and Forwarding (VRF) framework. The optional attributes make possible the coexistence of the already existing SRv6 End.DT6 implementation with the new SRv6 End.DT6 VRF-based implementation without breaking any backward compatibility. Further details on the SRv6 End.DT6 behavior (VRF mode) are reported in subsequent patches. From the userspace point of view, the support for optional attributes DO NOT require any changes to the userspace applications, i.e: iproute2 unless new attributes (required or optional) are needed. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:12 +03:00
attrs = slwt->desc->attrs | slwt->parsed_optattrs;
net: seg6: initialize induction variable to first valid array index Fixes the following warnings observed when building CONFIG_IPV6_SEG6_LWTUNNEL=y with clang: net/ipv6/seg6_local.o: warning: objtool: seg6_local_fill_encap() falls through to next function seg6_local_get_encap_size() net/ipv6/seg6_local.o: warning: objtool: seg6_local_cmp_encap() falls through to next function input_action_end() LLVM can fully unroll loops in seg6_local_get_encap_size() and seg6_local_cmp_encap(). One issue in those loops is that the induction variable is initialized to 0. The loop iterates over members of seg6_action_params, a global array of struct seg6_action_param calling their put() function pointer members. seg6_action_param uses an array initializer to initialize SEG6_LOCAL_SRH and later elements, which is the third enumeration of an anonymous union. The guard `if (attrs & SEG6_F_ATTR(i))` may prevent this from being called at runtime, but it would still be UB for `seg6_action_params[0]->put` to be called; the unrolled loop will make the initial iterations unreachable, which LLVM will later rotate to fallthrough to the next function. Make this more obvious that this cannot happen to the compiler by initializing the loop induction variable to the minimum valid index that seg6_action_params is initialized to. Reported-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Link: https://lore.kernel.org/r/20220802161203.622293-1-ndesaulniers@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-08-02 19:12:03 +03:00
for (i = SEG6_LOCAL_SRH; i < SEG6_LOCAL_MAX + 1; i++) {
seg6: fool-proof the processing of SRv6 behavior attributes The set of required attributes for a given SRv6 behavior is identified using a bitmap stored in an unsigned long, since the initial design of SRv6 networking in Linux. Recently the same approach has been used for identifying the optional attributes. However, the number of attributes supported by SRv6 behaviors depends on the size of the unsigned long type which changes with the architecture. Indeed, on a 64-bit architecture, an SRv6 behavior can support up to 64 attributes while on a 32-bit architecture it can support at most 32 attributes. To fool-proof the processing of SRv6 behaviors we verify, at compile time, that the set of all supported SRv6 attributes can be encoded into a bitmap stored in an unsigned long. Otherwise, kernel build fails forcing developers to reconsider adding a new attribute or extend the total number of supported attributes by the SRv6 behaviors. Moreover, we replace all patterns (1 << i) with the macro SEG6_F_ATTR(i) in order to address potential overflow issues caused by 32-bit signed arithmetic. Thanks to Colin Ian King for catching the overflow problem, providing a solution and inspiring this patch. Thanks to Jakub Kicinski for his useful suggestions during the design of this patch. v2: - remove the SEG6_LOCAL_MAX_SUPP which is not strictly needed: it can be derived from the unsigned long type. Thanks to David Ahern for pointing it out. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/r/20210206170934.5982-1-andrea.mayer@uniroma2.it Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-02-06 20:09:34 +03:00
if (attrs & SEG6_F_ATTR(i)) {
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:26 +03:00
param = &seg6_action_params[i];
err = param->put(skb, slwt);
if (err < 0)
return err;
}
}
return 0;
}
static int seg6_local_get_encap_size(struct lwtunnel_state *lwt)
{
struct seg6_local_lwt *slwt = seg6_local_lwtunnel(lwt);
unsigned long attrs;
int nlsize;
nlsize = nla_total_size(4); /* action */
seg6: add support for optional attributes in SRv6 behaviors Before this patch, each SRv6 behavior specifies a set of required attributes that must be provided by the userspace application when such behavior is going to be instantiated. If at least one of the required attributes is not provided, the creation of the behavior fails. The SRv6 behavior framework lacks a way to manage optional attributes. By definition, an optional attribute for a SRv6 behavior consists of an attribute which may or may not be provided by the userspace. Therefore, if an optional attribute is missing (and thus not supplied by the user) the creation of the behavior goes ahead without any issue. This patch explicitly differentiates the required attributes from the optional attributes. In particular, each behavior can declare a set of required attributes and a set of optional ones. The semantic of the required attributes remains *totally* unaffected by this patch. The introduction of the optional attributes does NOT impact on the backward compatibility of the existing SRv6 behaviors. It is essential to note that if an (optional or required) attribute is supplied to a SRv6 behavior which does not expect it, the behavior simply discards such attribute without generating any error or warning. This operating mode remained unchanged both before and after the introduction of the optional attributes extension. The optional attributes are one of the key components used to implement the SRv6 End.DT6 behavior based on the Virtual Routing and Forwarding (VRF) framework. The optional attributes make possible the coexistence of the already existing SRv6 End.DT6 implementation with the new SRv6 End.DT6 VRF-based implementation without breaking any backward compatibility. Further details on the SRv6 End.DT6 behavior (VRF mode) are reported in subsequent patches. From the userspace point of view, the support for optional attributes DO NOT require any changes to the userspace applications, i.e: iproute2 unless new attributes (required or optional) are needed. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:12 +03:00
attrs = slwt->desc->attrs | slwt->parsed_optattrs;
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:26 +03:00
seg6: fool-proof the processing of SRv6 behavior attributes The set of required attributes for a given SRv6 behavior is identified using a bitmap stored in an unsigned long, since the initial design of SRv6 networking in Linux. Recently the same approach has been used for identifying the optional attributes. However, the number of attributes supported by SRv6 behaviors depends on the size of the unsigned long type which changes with the architecture. Indeed, on a 64-bit architecture, an SRv6 behavior can support up to 64 attributes while on a 32-bit architecture it can support at most 32 attributes. To fool-proof the processing of SRv6 behaviors we verify, at compile time, that the set of all supported SRv6 attributes can be encoded into a bitmap stored in an unsigned long. Otherwise, kernel build fails forcing developers to reconsider adding a new attribute or extend the total number of supported attributes by the SRv6 behaviors. Moreover, we replace all patterns (1 << i) with the macro SEG6_F_ATTR(i) in order to address potential overflow issues caused by 32-bit signed arithmetic. Thanks to Colin Ian King for catching the overflow problem, providing a solution and inspiring this patch. Thanks to Jakub Kicinski for his useful suggestions during the design of this patch. v2: - remove the SEG6_LOCAL_MAX_SUPP which is not strictly needed: it can be derived from the unsigned long type. Thanks to David Ahern for pointing it out. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/r/20210206170934.5982-1-andrea.mayer@uniroma2.it Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-02-06 20:09:34 +03:00
if (attrs & SEG6_F_ATTR(SEG6_LOCAL_SRH))
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:26 +03:00
nlsize += nla_total_size((slwt->srh->hdrlen + 1) << 3);
seg6: fool-proof the processing of SRv6 behavior attributes The set of required attributes for a given SRv6 behavior is identified using a bitmap stored in an unsigned long, since the initial design of SRv6 networking in Linux. Recently the same approach has been used for identifying the optional attributes. However, the number of attributes supported by SRv6 behaviors depends on the size of the unsigned long type which changes with the architecture. Indeed, on a 64-bit architecture, an SRv6 behavior can support up to 64 attributes while on a 32-bit architecture it can support at most 32 attributes. To fool-proof the processing of SRv6 behaviors we verify, at compile time, that the set of all supported SRv6 attributes can be encoded into a bitmap stored in an unsigned long. Otherwise, kernel build fails forcing developers to reconsider adding a new attribute or extend the total number of supported attributes by the SRv6 behaviors. Moreover, we replace all patterns (1 << i) with the macro SEG6_F_ATTR(i) in order to address potential overflow issues caused by 32-bit signed arithmetic. Thanks to Colin Ian King for catching the overflow problem, providing a solution and inspiring this patch. Thanks to Jakub Kicinski for his useful suggestions during the design of this patch. v2: - remove the SEG6_LOCAL_MAX_SUPP which is not strictly needed: it can be derived from the unsigned long type. Thanks to David Ahern for pointing it out. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/r/20210206170934.5982-1-andrea.mayer@uniroma2.it Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-02-06 20:09:34 +03:00
if (attrs & SEG6_F_ATTR(SEG6_LOCAL_TABLE))
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:26 +03:00
nlsize += nla_total_size(4);
seg6: fool-proof the processing of SRv6 behavior attributes The set of required attributes for a given SRv6 behavior is identified using a bitmap stored in an unsigned long, since the initial design of SRv6 networking in Linux. Recently the same approach has been used for identifying the optional attributes. However, the number of attributes supported by SRv6 behaviors depends on the size of the unsigned long type which changes with the architecture. Indeed, on a 64-bit architecture, an SRv6 behavior can support up to 64 attributes while on a 32-bit architecture it can support at most 32 attributes. To fool-proof the processing of SRv6 behaviors we verify, at compile time, that the set of all supported SRv6 attributes can be encoded into a bitmap stored in an unsigned long. Otherwise, kernel build fails forcing developers to reconsider adding a new attribute or extend the total number of supported attributes by the SRv6 behaviors. Moreover, we replace all patterns (1 << i) with the macro SEG6_F_ATTR(i) in order to address potential overflow issues caused by 32-bit signed arithmetic. Thanks to Colin Ian King for catching the overflow problem, providing a solution and inspiring this patch. Thanks to Jakub Kicinski for his useful suggestions during the design of this patch. v2: - remove the SEG6_LOCAL_MAX_SUPP which is not strictly needed: it can be derived from the unsigned long type. Thanks to David Ahern for pointing it out. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/r/20210206170934.5982-1-andrea.mayer@uniroma2.it Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-02-06 20:09:34 +03:00
if (attrs & SEG6_F_ATTR(SEG6_LOCAL_NH4))
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:26 +03:00
nlsize += nla_total_size(4);
seg6: fool-proof the processing of SRv6 behavior attributes The set of required attributes for a given SRv6 behavior is identified using a bitmap stored in an unsigned long, since the initial design of SRv6 networking in Linux. Recently the same approach has been used for identifying the optional attributes. However, the number of attributes supported by SRv6 behaviors depends on the size of the unsigned long type which changes with the architecture. Indeed, on a 64-bit architecture, an SRv6 behavior can support up to 64 attributes while on a 32-bit architecture it can support at most 32 attributes. To fool-proof the processing of SRv6 behaviors we verify, at compile time, that the set of all supported SRv6 attributes can be encoded into a bitmap stored in an unsigned long. Otherwise, kernel build fails forcing developers to reconsider adding a new attribute or extend the total number of supported attributes by the SRv6 behaviors. Moreover, we replace all patterns (1 << i) with the macro SEG6_F_ATTR(i) in order to address potential overflow issues caused by 32-bit signed arithmetic. Thanks to Colin Ian King for catching the overflow problem, providing a solution and inspiring this patch. Thanks to Jakub Kicinski for his useful suggestions during the design of this patch. v2: - remove the SEG6_LOCAL_MAX_SUPP which is not strictly needed: it can be derived from the unsigned long type. Thanks to David Ahern for pointing it out. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/r/20210206170934.5982-1-andrea.mayer@uniroma2.it Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-02-06 20:09:34 +03:00
if (attrs & SEG6_F_ATTR(SEG6_LOCAL_NH6))
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:26 +03:00
nlsize += nla_total_size(16);
seg6: fool-proof the processing of SRv6 behavior attributes The set of required attributes for a given SRv6 behavior is identified using a bitmap stored in an unsigned long, since the initial design of SRv6 networking in Linux. Recently the same approach has been used for identifying the optional attributes. However, the number of attributes supported by SRv6 behaviors depends on the size of the unsigned long type which changes with the architecture. Indeed, on a 64-bit architecture, an SRv6 behavior can support up to 64 attributes while on a 32-bit architecture it can support at most 32 attributes. To fool-proof the processing of SRv6 behaviors we verify, at compile time, that the set of all supported SRv6 attributes can be encoded into a bitmap stored in an unsigned long. Otherwise, kernel build fails forcing developers to reconsider adding a new attribute or extend the total number of supported attributes by the SRv6 behaviors. Moreover, we replace all patterns (1 << i) with the macro SEG6_F_ATTR(i) in order to address potential overflow issues caused by 32-bit signed arithmetic. Thanks to Colin Ian King for catching the overflow problem, providing a solution and inspiring this patch. Thanks to Jakub Kicinski for his useful suggestions during the design of this patch. v2: - remove the SEG6_LOCAL_MAX_SUPP which is not strictly needed: it can be derived from the unsigned long type. Thanks to David Ahern for pointing it out. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/r/20210206170934.5982-1-andrea.mayer@uniroma2.it Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-02-06 20:09:34 +03:00
if (attrs & SEG6_F_ATTR(SEG6_LOCAL_IIF))
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:26 +03:00
nlsize += nla_total_size(4);
seg6: fool-proof the processing of SRv6 behavior attributes The set of required attributes for a given SRv6 behavior is identified using a bitmap stored in an unsigned long, since the initial design of SRv6 networking in Linux. Recently the same approach has been used for identifying the optional attributes. However, the number of attributes supported by SRv6 behaviors depends on the size of the unsigned long type which changes with the architecture. Indeed, on a 64-bit architecture, an SRv6 behavior can support up to 64 attributes while on a 32-bit architecture it can support at most 32 attributes. To fool-proof the processing of SRv6 behaviors we verify, at compile time, that the set of all supported SRv6 attributes can be encoded into a bitmap stored in an unsigned long. Otherwise, kernel build fails forcing developers to reconsider adding a new attribute or extend the total number of supported attributes by the SRv6 behaviors. Moreover, we replace all patterns (1 << i) with the macro SEG6_F_ATTR(i) in order to address potential overflow issues caused by 32-bit signed arithmetic. Thanks to Colin Ian King for catching the overflow problem, providing a solution and inspiring this patch. Thanks to Jakub Kicinski for his useful suggestions during the design of this patch. v2: - remove the SEG6_LOCAL_MAX_SUPP which is not strictly needed: it can be derived from the unsigned long type. Thanks to David Ahern for pointing it out. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/r/20210206170934.5982-1-andrea.mayer@uniroma2.it Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-02-06 20:09:34 +03:00
if (attrs & SEG6_F_ATTR(SEG6_LOCAL_OIF))
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:26 +03:00
nlsize += nla_total_size(4);
seg6: fool-proof the processing of SRv6 behavior attributes The set of required attributes for a given SRv6 behavior is identified using a bitmap stored in an unsigned long, since the initial design of SRv6 networking in Linux. Recently the same approach has been used for identifying the optional attributes. However, the number of attributes supported by SRv6 behaviors depends on the size of the unsigned long type which changes with the architecture. Indeed, on a 64-bit architecture, an SRv6 behavior can support up to 64 attributes while on a 32-bit architecture it can support at most 32 attributes. To fool-proof the processing of SRv6 behaviors we verify, at compile time, that the set of all supported SRv6 attributes can be encoded into a bitmap stored in an unsigned long. Otherwise, kernel build fails forcing developers to reconsider adding a new attribute or extend the total number of supported attributes by the SRv6 behaviors. Moreover, we replace all patterns (1 << i) with the macro SEG6_F_ATTR(i) in order to address potential overflow issues caused by 32-bit signed arithmetic. Thanks to Colin Ian King for catching the overflow problem, providing a solution and inspiring this patch. Thanks to Jakub Kicinski for his useful suggestions during the design of this patch. v2: - remove the SEG6_LOCAL_MAX_SUPP which is not strictly needed: it can be derived from the unsigned long type. Thanks to David Ahern for pointing it out. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/r/20210206170934.5982-1-andrea.mayer@uniroma2.it Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-02-06 20:09:34 +03:00
if (attrs & SEG6_F_ATTR(SEG6_LOCAL_BPF))
ipv6: sr: Add seg6local action End.BPF This patch adds the End.BPF action to the LWT seg6local infrastructure. This action works like any other seg6local End action, meaning that an IPv6 header with SRH is needed, whose DA has to be equal to the SID of the action. It will also advance the SRH to the next segment, the BPF program does not have to take care of this. Since the BPF program may not be a source of instability in the kernel, it is important to ensure that the integrity of the packet is maintained before yielding it back to the IPv6 layer. The hook hence keeps track if the SRH has been altered through the helpers, and re-validates its content if needed with seg6_validate_srh. The state kept for validation is stored in a per-CPU buffer. The BPF program is not allowed to directly write into the packet, and only some fields of the SRH can be altered through the helper bpf_lwt_seg6_store_bytes. Performances profiling has shown that the SRH re-validation does not induce a significant overhead. If the altered SRH is deemed as invalid, the packet is dropped. This validation is also done before executing any action through bpf_lwt_seg6_action, and will not be performed again if the SRH is not modified after calling the action. The BPF program may return 3 types of return codes: - BPF_OK: the End.BPF action will look up the next destination through seg6_lookup_nexthop. - BPF_REDIRECT: if an action has been executed through the bpf_lwt_seg6_action helper, the BPF program should return this value, as the skb's destination is already set and the default lookup should not be performed. - BPF_DROP : the packet will be dropped. Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-20 16:58:16 +03:00
nlsize += nla_total_size(sizeof(struct nlattr)) +
nla_total_size(MAX_PROG_NAME) +
nla_total_size(4);
seg6: fool-proof the processing of SRv6 behavior attributes The set of required attributes for a given SRv6 behavior is identified using a bitmap stored in an unsigned long, since the initial design of SRv6 networking in Linux. Recently the same approach has been used for identifying the optional attributes. However, the number of attributes supported by SRv6 behaviors depends on the size of the unsigned long type which changes with the architecture. Indeed, on a 64-bit architecture, an SRv6 behavior can support up to 64 attributes while on a 32-bit architecture it can support at most 32 attributes. To fool-proof the processing of SRv6 behaviors we verify, at compile time, that the set of all supported SRv6 attributes can be encoded into a bitmap stored in an unsigned long. Otherwise, kernel build fails forcing developers to reconsider adding a new attribute or extend the total number of supported attributes by the SRv6 behaviors. Moreover, we replace all patterns (1 << i) with the macro SEG6_F_ATTR(i) in order to address potential overflow issues caused by 32-bit signed arithmetic. Thanks to Colin Ian King for catching the overflow problem, providing a solution and inspiring this patch. Thanks to Jakub Kicinski for his useful suggestions during the design of this patch. v2: - remove the SEG6_LOCAL_MAX_SUPP which is not strictly needed: it can be derived from the unsigned long type. Thanks to David Ahern for pointing it out. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/r/20210206170934.5982-1-andrea.mayer@uniroma2.it Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-02-06 20:09:34 +03:00
if (attrs & SEG6_F_ATTR(SEG6_LOCAL_VRFTABLE))
seg6: add support for the SRv6 End.DT4 behavior SRv6 End.DT4 is defined in the SRv6 Network Programming [1]. The SRv6 End.DT4 is used to implement IPv4 L3VPN use-cases in multi-tenants environments. It decapsulates the received packets and it performs IPv4 routing lookup in the routing table of the tenant. The SRv6 End.DT4 Linux implementation leverages a VRF device in order to force the routing lookup into the associated routing table. To make the End.DT4 work properly, it must be guaranteed that the routing table used for routing lookup operations is bound to one and only one VRF during the tunnel creation. Such constraint has to be enforced by enabling the VRF strict_mode sysctl parameter, i.e: $ sysctl -wq net.vrf.strict_mode=1. At JANOG44, LINE corporation presented their multi-tenant DC architecture using SRv6 [2]. In the slides, they reported that the Linux kernel is missing the support of SRv6 End.DT4 behavior. The SRv6 End.DT4 behavior can be instantiated using a command similar to the following: $ ip route add 2001:db8::1 encap seg6local action End.DT4 vrftable 100 dev eth0 We introduce the "vrftable" extension in iproute2 in a following patch. [1] https://tools.ietf.org/html/draft-ietf-spring-srv6-network-programming [2] https://speakerdeck.com/line_developers/line-data-center-networking-with-srv6 Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:14 +03:00
nlsize += nla_total_size(4);
seg6: add counters support for SRv6 Behaviors This patch provides counters for SRv6 Behaviors as defined in [1], section 6. For each SRv6 Behavior instance, counters defined in [1] are: - the total number of packets that have been correctly processed; - the total amount of traffic in bytes of all packets that have been correctly processed; In addition, this patch introduces a new counter that counts the number of packets that have NOT been properly processed (i.e. errors) by an SRv6 Behavior instance. Counters are not only interesting for network monitoring purposes (i.e. counting the number of packets processed by a given behavior) but they also provide a simple tool for checking whether a behavior instance is working as we expect or not. Counters can be useful for troubleshooting misconfigured SRv6 networks. Indeed, an SRv6 Behavior can silently drop packets for very different reasons (i.e. wrong SID configuration, interfaces set with SID addresses, etc) without any notification/message to the user. Due to the nature of SRv6 networks, diagnostic tools such as ping and traceroute may be ineffective: paths used for reaching a given router can be totally different from the ones followed by probe packets. In addition, paths are often asymmetrical and this makes it even more difficult to keep up with the journey of the packets and to understand which behaviors are actually processing our traffic. When counters are enabled on an SRv6 Behavior instance, it is possible to verify if packets are actually processed by such behavior and what is the outcome of the processing. Therefore, the counters for SRv6 Behaviors offer an non-invasive observability point which can be leveraged for both traffic monitoring and troubleshooting purposes. [1] https://www.rfc-editor.org/rfc/rfc8986.html#name-counters Troubleshooting using SRv6 Behavior counters -------------------------------------------- Let's make a brief example to see how helpful counters can be for SRv6 networks. Let's consider a node where an SRv6 End Behavior receives an SRv6 packet whose Segment Left (SL) is equal to 0. In this case, the End Behavior (which accepts only packets with SL >= 1) discards the packet and increases the error counter. This information can be leveraged by the network operator for troubleshooting. Indeed, the error counter is telling the user that the packet: (i) arrived at the node; (ii) the packet has been taken into account by the SRv6 End behavior; (iii) but an error has occurred during the processing. The error (iii) could be caused by different reasons, such as wrong route settings on the node or due to an invalid SID List carried by the SRv6 packet. Anyway, the error counter is used to exclude that the packet did not arrive at the node or it has not been processed by the behavior at all. Turning on/off counters for SRv6 Behaviors ------------------------------------------ Each SRv6 Behavior instance can be configured, at the time of its creation, to make use of counters. This is done through iproute2 which allows the user to create an SRv6 Behavior instance specifying the optional "count" attribute as shown in the following example: $ ip -6 route add 2001:db8::1 encap seg6local action End count dev eth0 per-behavior counters can be shown by adding "-s" to the iproute2 command line, i.e.: $ ip -s -6 route show 2001:db8::1 2001:db8::1 encap seg6local action End packets 0 bytes 0 errors 0 dev eth0 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Impact of counters for SRv6 Behaviors on performance ==================================================== To determine the performance impact due to the introduction of counters in the SRv6 Behavior subsystem, we have carried out extensive tests. We chose to test the throughput achieved by the SRv6 End.DX2 Behavior because, among all the other behaviors implemented so far, it reaches the highest throughput which is around 1.5 Mpps (per core at 2.4 GHz on a Xeon(R) CPU E5-2630 v3) on kernel 5.12-rc2 using packets of size ~ 100 bytes. Three different tests were conducted in order to evaluate the overall throughput of the SRv6 End.DX2 Behavior in the following scenarios: 1) vanilla kernel (without the SRv6 Behavior counters patch) and a single instance of an SRv6 End.DX2 Behavior; 2) patched kernel with SRv6 Behavior counters and a single instance of an SRv6 End.DX2 Behavior with counters turned off; 3) patched kernel with SRv6 Behavior counters and a single instance of SRv6 End.DX2 Behavior with counters turned on. All tests were performed on a testbed deployed on the CloudLab facilities [2], a flexible infrastructure dedicated to scientific research on the future of Cloud Computing. Results of tests are shown in the following table: Scenario (1): average 1504764,81 pps (~1504,76 kpps); std. dev 3956,82 pps Scenario (2): average 1501469,78 pps (~1501,47 kpps); std. dev 2979,85 pps Scenario (3): average 1501315,13 pps (~1501,32 kpps); std. dev 2956,00 pps As can be observed, throughputs achieved in scenarios (2),(3) did not suffer any observable degradation compared to scenario (1). Thanks to Jakub Kicinski and David Ahern for their valuable suggestions and comments provided during the discussion of the proposed RFCs. [2] https://www.cloudlab.us Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-04-27 18:44:04 +03:00
if (attrs & SEG6_F_LOCAL_COUNTERS)
nlsize += nla_total_size(0) + /* nest SEG6_LOCAL_COUNTERS */
/* SEG6_LOCAL_CNT_PACKETS */
nla_total_size_64bit(sizeof(__u64)) +
/* SEG6_LOCAL_CNT_BYTES */
nla_total_size_64bit(sizeof(__u64)) +
/* SEG6_LOCAL_CNT_ERRORS */
nla_total_size_64bit(sizeof(__u64));
seg6: add NEXT-C-SID support for SRv6 End behavior The NEXT-C-SID mechanism described in [1] offers the possibility of encoding several SRv6 segments within a single 128 bit SID address. Such a SID address is called a Compressed SID (C-SID) container. In this way, the length of the SID List can be drastically reduced. A SID instantiated with the NEXT-C-SID flavor considers an IPv6 address logically structured in three main blocks: i) Locator-Block; ii) Locator-Node Function; iii) Argument. C-SID container +------------------------------------------------------------------+ | Locator-Block |Loc-Node| Argument | | |Function| | +------------------------------------------------------------------+ <--------- B -----------> <- NF -> <------------- A ---------------> (i) The Locator-Block can be any IPv6 prefix available to the provider; (ii) The Locator-Node Function represents the node and the function to be triggered when a packet is received on the node; (iii) The Argument carries the remaining C-SIDs in the current C-SID container. The NEXT-C-SID mechanism relies on the "flavors" framework defined in [2]. The flavors represent additional operations that can modify or extend a subset of the existing behaviors. This patch introduces the support for flavors in SRv6 End behavior implementing the NEXT-C-SID one. An SRv6 End behavior with NEXT-C-SID flavor works as an End behavior but it is capable of processing the compressed SID List encoded in C-SID containers. An SRv6 End behavior with NEXT-C-SID flavor can be configured to support user-provided Locator-Block and Locator-Node Function lengths. In this implementation, such lengths must be evenly divisible by 8 (i.e. must be byte-aligned), otherwise the kernel informs the user about invalid values with a meaningful error code and message through netlink_ext_ack. If Locator-Block and/or Locator-Node Function lengths are not provided by the user during configuration of an SRv6 End behavior instance with NEXT-C-SID flavor, the kernel will choose their default values i.e., 32-bit Locator-Block and 16-bit Locator-Node Function. [1] - https://datatracker.ietf.org/doc/html/draft-ietf-spring-srv6-srh-compression [2] - https://datatracker.ietf.org/doc/html/rfc8986 Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-09-12 20:16:18 +03:00
if (attrs & SEG6_F_ATTR(SEG6_LOCAL_FLAVORS))
nlsize += encap_size_flavors(slwt);
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:26 +03:00
return nlsize;
}
static int seg6_local_cmp_encap(struct lwtunnel_state *a,
struct lwtunnel_state *b)
{
struct seg6_local_lwt *slwt_a, *slwt_b;
struct seg6_action_param *param;
seg6: add support for optional attributes in SRv6 behaviors Before this patch, each SRv6 behavior specifies a set of required attributes that must be provided by the userspace application when such behavior is going to be instantiated. If at least one of the required attributes is not provided, the creation of the behavior fails. The SRv6 behavior framework lacks a way to manage optional attributes. By definition, an optional attribute for a SRv6 behavior consists of an attribute which may or may not be provided by the userspace. Therefore, if an optional attribute is missing (and thus not supplied by the user) the creation of the behavior goes ahead without any issue. This patch explicitly differentiates the required attributes from the optional attributes. In particular, each behavior can declare a set of required attributes and a set of optional ones. The semantic of the required attributes remains *totally* unaffected by this patch. The introduction of the optional attributes does NOT impact on the backward compatibility of the existing SRv6 behaviors. It is essential to note that if an (optional or required) attribute is supplied to a SRv6 behavior which does not expect it, the behavior simply discards such attribute without generating any error or warning. This operating mode remained unchanged both before and after the introduction of the optional attributes extension. The optional attributes are one of the key components used to implement the SRv6 End.DT6 behavior based on the Virtual Routing and Forwarding (VRF) framework. The optional attributes make possible the coexistence of the already existing SRv6 End.DT6 implementation with the new SRv6 End.DT6 VRF-based implementation without breaking any backward compatibility. Further details on the SRv6 End.DT6 behavior (VRF mode) are reported in subsequent patches. From the userspace point of view, the support for optional attributes DO NOT require any changes to the userspace applications, i.e: iproute2 unless new attributes (required or optional) are needed. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:12 +03:00
unsigned long attrs_a, attrs_b;
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:26 +03:00
int i;
slwt_a = seg6_local_lwtunnel(a);
slwt_b = seg6_local_lwtunnel(b);
if (slwt_a->action != slwt_b->action)
return 1;
seg6: add support for optional attributes in SRv6 behaviors Before this patch, each SRv6 behavior specifies a set of required attributes that must be provided by the userspace application when such behavior is going to be instantiated. If at least one of the required attributes is not provided, the creation of the behavior fails. The SRv6 behavior framework lacks a way to manage optional attributes. By definition, an optional attribute for a SRv6 behavior consists of an attribute which may or may not be provided by the userspace. Therefore, if an optional attribute is missing (and thus not supplied by the user) the creation of the behavior goes ahead without any issue. This patch explicitly differentiates the required attributes from the optional attributes. In particular, each behavior can declare a set of required attributes and a set of optional ones. The semantic of the required attributes remains *totally* unaffected by this patch. The introduction of the optional attributes does NOT impact on the backward compatibility of the existing SRv6 behaviors. It is essential to note that if an (optional or required) attribute is supplied to a SRv6 behavior which does not expect it, the behavior simply discards such attribute without generating any error or warning. This operating mode remained unchanged both before and after the introduction of the optional attributes extension. The optional attributes are one of the key components used to implement the SRv6 End.DT6 behavior based on the Virtual Routing and Forwarding (VRF) framework. The optional attributes make possible the coexistence of the already existing SRv6 End.DT6 implementation with the new SRv6 End.DT6 VRF-based implementation without breaking any backward compatibility. Further details on the SRv6 End.DT6 behavior (VRF mode) are reported in subsequent patches. From the userspace point of view, the support for optional attributes DO NOT require any changes to the userspace applications, i.e: iproute2 unless new attributes (required or optional) are needed. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02 16:05:12 +03:00
attrs_a = slwt_a->desc->attrs | slwt_a->parsed_optattrs;
attrs_b = slwt_b->desc->attrs | slwt_b->parsed_optattrs;
if (attrs_a != attrs_b)
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:26 +03:00
return 1;
net: seg6: initialize induction variable to first valid array index Fixes the following warnings observed when building CONFIG_IPV6_SEG6_LWTUNNEL=y with clang: net/ipv6/seg6_local.o: warning: objtool: seg6_local_fill_encap() falls through to next function seg6_local_get_encap_size() net/ipv6/seg6_local.o: warning: objtool: seg6_local_cmp_encap() falls through to next function input_action_end() LLVM can fully unroll loops in seg6_local_get_encap_size() and seg6_local_cmp_encap(). One issue in those loops is that the induction variable is initialized to 0. The loop iterates over members of seg6_action_params, a global array of struct seg6_action_param calling their put() function pointer members. seg6_action_param uses an array initializer to initialize SEG6_LOCAL_SRH and later elements, which is the third enumeration of an anonymous union. The guard `if (attrs & SEG6_F_ATTR(i))` may prevent this from being called at runtime, but it would still be UB for `seg6_action_params[0]->put` to be called; the unrolled loop will make the initial iterations unreachable, which LLVM will later rotate to fallthrough to the next function. Make this more obvious that this cannot happen to the compiler by initializing the loop induction variable to the minimum valid index that seg6_action_params is initialized to. Reported-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Link: https://lore.kernel.org/r/20220802161203.622293-1-ndesaulniers@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-08-02 19:12:03 +03:00
for (i = SEG6_LOCAL_SRH; i < SEG6_LOCAL_MAX + 1; i++) {
seg6: fool-proof the processing of SRv6 behavior attributes The set of required attributes for a given SRv6 behavior is identified using a bitmap stored in an unsigned long, since the initial design of SRv6 networking in Linux. Recently the same approach has been used for identifying the optional attributes. However, the number of attributes supported by SRv6 behaviors depends on the size of the unsigned long type which changes with the architecture. Indeed, on a 64-bit architecture, an SRv6 behavior can support up to 64 attributes while on a 32-bit architecture it can support at most 32 attributes. To fool-proof the processing of SRv6 behaviors we verify, at compile time, that the set of all supported SRv6 attributes can be encoded into a bitmap stored in an unsigned long. Otherwise, kernel build fails forcing developers to reconsider adding a new attribute or extend the total number of supported attributes by the SRv6 behaviors. Moreover, we replace all patterns (1 << i) with the macro SEG6_F_ATTR(i) in order to address potential overflow issues caused by 32-bit signed arithmetic. Thanks to Colin Ian King for catching the overflow problem, providing a solution and inspiring this patch. Thanks to Jakub Kicinski for his useful suggestions during the design of this patch. v2: - remove the SEG6_LOCAL_MAX_SUPP which is not strictly needed: it can be derived from the unsigned long type. Thanks to David Ahern for pointing it out. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/r/20210206170934.5982-1-andrea.mayer@uniroma2.it Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-02-06 20:09:34 +03:00
if (attrs_a & SEG6_F_ATTR(i)) {
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:26 +03:00
param = &seg6_action_params[i];
if (param->cmp(slwt_a, slwt_b))
return 1;
}
}
return 0;
}
static const struct lwtunnel_encap_ops seg6_local_ops = {
.build_state = seg6_local_build_state,
.destroy_state = seg6_local_destroy_state,
.input = seg6_local_input,
.fill_encap = seg6_local_fill_encap,
.get_encap_size = seg6_local_get_encap_size,
.cmp_encap = seg6_local_cmp_encap,
.owner = THIS_MODULE,
};
int __init seg6_local_init(void)
{
seg6: fool-proof the processing of SRv6 behavior attributes The set of required attributes for a given SRv6 behavior is identified using a bitmap stored in an unsigned long, since the initial design of SRv6 networking in Linux. Recently the same approach has been used for identifying the optional attributes. However, the number of attributes supported by SRv6 behaviors depends on the size of the unsigned long type which changes with the architecture. Indeed, on a 64-bit architecture, an SRv6 behavior can support up to 64 attributes while on a 32-bit architecture it can support at most 32 attributes. To fool-proof the processing of SRv6 behaviors we verify, at compile time, that the set of all supported SRv6 attributes can be encoded into a bitmap stored in an unsigned long. Otherwise, kernel build fails forcing developers to reconsider adding a new attribute or extend the total number of supported attributes by the SRv6 behaviors. Moreover, we replace all patterns (1 << i) with the macro SEG6_F_ATTR(i) in order to address potential overflow issues caused by 32-bit signed arithmetic. Thanks to Colin Ian King for catching the overflow problem, providing a solution and inspiring this patch. Thanks to Jakub Kicinski for his useful suggestions during the design of this patch. v2: - remove the SEG6_LOCAL_MAX_SUPP which is not strictly needed: it can be derived from the unsigned long type. Thanks to David Ahern for pointing it out. Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/r/20210206170934.5982-1-andrea.mayer@uniroma2.it Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-02-06 20:09:34 +03:00
/* If the max total number of defined attributes is reached, then your
* kernel build stops here.
*
* This check is required to avoid arithmetic overflows when processing
* behavior attributes and the maximum number of defined attributes
* exceeds the allowed value.
*/
BUILD_BUG_ON(SEG6_LOCAL_MAX + 1 > BITS_PER_TYPE(unsigned long));
seg6: add NEXT-C-SID support for SRv6 End behavior The NEXT-C-SID mechanism described in [1] offers the possibility of encoding several SRv6 segments within a single 128 bit SID address. Such a SID address is called a Compressed SID (C-SID) container. In this way, the length of the SID List can be drastically reduced. A SID instantiated with the NEXT-C-SID flavor considers an IPv6 address logically structured in three main blocks: i) Locator-Block; ii) Locator-Node Function; iii) Argument. C-SID container +------------------------------------------------------------------+ | Locator-Block |Loc-Node| Argument | | |Function| | +------------------------------------------------------------------+ <--------- B -----------> <- NF -> <------------- A ---------------> (i) The Locator-Block can be any IPv6 prefix available to the provider; (ii) The Locator-Node Function represents the node and the function to be triggered when a packet is received on the node; (iii) The Argument carries the remaining C-SIDs in the current C-SID container. The NEXT-C-SID mechanism relies on the "flavors" framework defined in [2]. The flavors represent additional operations that can modify or extend a subset of the existing behaviors. This patch introduces the support for flavors in SRv6 End behavior implementing the NEXT-C-SID one. An SRv6 End behavior with NEXT-C-SID flavor works as an End behavior but it is capable of processing the compressed SID List encoded in C-SID containers. An SRv6 End behavior with NEXT-C-SID flavor can be configured to support user-provided Locator-Block and Locator-Node Function lengths. In this implementation, such lengths must be evenly divisible by 8 (i.e. must be byte-aligned), otherwise the kernel informs the user about invalid values with a meaningful error code and message through netlink_ext_ack. If Locator-Block and/or Locator-Node Function lengths are not provided by the user during configuration of an SRv6 End behavior instance with NEXT-C-SID flavor, the kernel will choose their default values i.e., 32-bit Locator-Block and 16-bit Locator-Node Function. [1] - https://datatracker.ietf.org/doc/html/draft-ietf-spring-srv6-srh-compression [2] - https://datatracker.ietf.org/doc/html/rfc8986 Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-09-12 20:16:18 +03:00
/* If the default NEXT-C-SID Locator-Block/Node Function lengths (in
* bits) have been changed with invalid values, kernel build stops
* here.
*/
BUILD_BUG_ON(next_csid_chk_cntr_bits(SEG6_LOCAL_LCBLOCK_DBITS,
SEG6_LOCAL_LCNODE_FN_DBITS));
BUILD_BUG_ON(next_csid_chk_lcblock_bits(SEG6_LOCAL_LCBLOCK_DBITS));
BUILD_BUG_ON(next_csid_chk_lcnode_fn_bits(SEG6_LOCAL_LCNODE_FN_DBITS));
seg6: add PSP flavor support for SRv6 End behavior The "flavors" framework defined in RFC8986 [1] represents additional operations that can modify or extend a subset of existing behaviors such as SRv6 End, End.X and End.T. We report these flavors hereafter: - Penultimate Segment Pop (PSP); - Ultimate Segment Pop (USP); - Ultimate Segment Decapsulation (USD). Depending on how the Segment Routing Header (SRH) has to be handled, an SRv6 End* behavior can support these flavors either individually or in combinations. In this patch, we only consider the PSP flavor for the SRv6 End behavior. A PSP enabled SRv6 End behavior is used by the Source/Ingress SR node (i.e., the one applying the SRv6 Policy) when it needs to instruct the penultimate SR Endpoint node listed in the SID List (carried by the SRH) to remove the SRH from the IPv6 header. Specifically, a PSP enabled SRv6 End behavior processes the SRH by: i) decreasing the Segment Left (SL) from 1 to 0; ii) copying the Last Segment IDentifier (SID) into the IPv6 Destination Address (DA); iii) removing (i.e., popping) the outer SRH from the extension headers following the IPv6 header. It is important to note that PSP operation (steps i, ii, iii) takes place only at a penultimate SR Segment Endpoint node (i.e., when the SL=1) and does not happen at non-penultimate Endpoint nodes. Indeed, when a SID of PSP flavor is processed at a non-penultimate SR Segment Endpoint node, the PSP operation is not performed because it would not be possible to decrease the SL from 1 to 0. SL=2 SL=1 SL=0 | | | For example, given the SRv6 policy (SID List := < X, Y, Z >): - a PSP enabled SRv6 End behavior bound to SID "Y" will apply the PSP operation as Segment Left (SL) is 1, corresponding to the Penultimate Segment of the SID List; - a PSP enabled SRv6 End behavior bound to SID "X" will *NOT* apply the PSP operation as the Segment Left is 2. This behavior instance will apply the "standard" End packet processing, ignoring the configured PSP flavor at all. [1] - RFC8986: https://datatracker.ietf.org/doc/html/rfc8986 Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2023-02-15 16:46:58 +03:00
/* To be memory efficient, we use 'u8' to represent the different
* actions related to RFC8986 flavors. If the kernel build stops here,
* it means that it is not possible to correctly encode these actions
* with the data type chosen for the action table.
*/
BUILD_BUG_ON(SEG6_LOCAL_FLV_ACT_MAX > (typeof(flv8986_act_tbl[0]))~0U);
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 13:38:26 +03:00
return lwtunnel_encap_add_ops(&seg6_local_ops,
LWTUNNEL_ENCAP_SEG6_LOCAL);
}
void seg6_local_exit(void)
{
lwtunnel_encap_del_ops(&seg6_local_ops, LWTUNNEL_ENCAP_SEG6_LOCAL);
}
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