e41294408c
RFC8754 says:
ICMP error packets generated within the SR domain are sent to source
nodes within the SR domain. The invoking packet in the ICMP error
message may contain an SRH. Since the destination address of a packet
with an SRH changes as each segment is processed, it may not be the
destination used by the socket or application that generated the
invoking packet.
For the source of an invoking packet to process the ICMP error
message, the ultimate destination address of the IPv6 header may be
required. The following logic is used to determine the destination
address for use by protocol-error handlers.
* Walk all extension headers of the invoking IPv6 packet to the
routing extension header preceding the upper-layer header.
- If routing header is type 4 Segment Routing Header (SRH)
o The SID at Segment List[0] may be used as the destination
address of the invoking packet.
Mangle the skb so the network header points to the invoking packet
inside the ICMP packet. The seg6 helpers can then be used on the skb
to find any segment routing headers. If found, mark this fact in the
IPv6 control block of the skb, and store the offset into the packet of
the SRH. Then restore the skb back to its old state.
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>
69 lines
1.7 KiB
C
69 lines
1.7 KiB
C
/* SPDX-License-Identifier: GPL-2.0-or-later */
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/*
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* SR-IPv6 implementation
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*
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* Author:
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* David Lebrun <david.lebrun@uclouvain.be>
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*/
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#ifndef _NET_SEG6_H
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#define _NET_SEG6_H
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#include <linux/net.h>
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#include <linux/ipv6.h>
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#include <linux/seg6.h>
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#include <linux/rhashtable-types.h>
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static inline void update_csum_diff4(struct sk_buff *skb, __be32 from,
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__be32 to)
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{
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__be32 diff[] = { ~from, to };
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skb->csum = ~csum_partial((char *)diff, sizeof(diff), ~skb->csum);
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}
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static inline void update_csum_diff16(struct sk_buff *skb, __be32 *from,
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__be32 *to)
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{
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__be32 diff[] = {
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~from[0], ~from[1], ~from[2], ~from[3],
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to[0], to[1], to[2], to[3],
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};
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skb->csum = ~csum_partial((char *)diff, sizeof(diff), ~skb->csum);
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}
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struct seg6_pernet_data {
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struct mutex lock;
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struct in6_addr __rcu *tun_src;
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#ifdef CONFIG_IPV6_SEG6_HMAC
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struct rhashtable hmac_infos;
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#endif
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};
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static inline struct seg6_pernet_data *seg6_pernet(struct net *net)
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{
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#if IS_ENABLED(CONFIG_IPV6)
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return net->ipv6.seg6_data;
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#else
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return NULL;
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#endif
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}
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extern int seg6_init(void);
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extern void seg6_exit(void);
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extern int seg6_iptunnel_init(void);
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extern void seg6_iptunnel_exit(void);
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extern int seg6_local_init(void);
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extern void seg6_local_exit(void);
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extern bool seg6_validate_srh(struct ipv6_sr_hdr *srh, int len, bool reduced);
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extern struct ipv6_sr_hdr *seg6_get_srh(struct sk_buff *skb, int flags);
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extern void seg6_icmp_srh(struct sk_buff *skb, struct inet6_skb_parm *opt);
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extern int seg6_do_srh_encap(struct sk_buff *skb, struct ipv6_sr_hdr *osrh,
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int proto);
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extern int seg6_do_srh_inline(struct sk_buff *skb, struct ipv6_sr_hdr *osrh);
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extern int seg6_lookup_nexthop(struct sk_buff *skb, struct in6_addr *nhaddr,
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u32 tbl_id);
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#endif
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