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proc_creat_seq() that directly take a struct seq_operations,
and deal with network namespaces in ->open.
Signed-off-by: Yejune Deng <yejune.deng@gmail.com>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
All comment lines inside the comment block have been aligned.
Every line of comment starts with a * (uniformity in code).
Signed-off-by: Shubhankar Kuranagatti <shubhankarvk@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The extra space before tab space has been removed.
Signed-off-by: Shubhankar Kuranagatti <shubhankarvk@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
After installing a route to the kernel, user space receives an
acknowledgment, which means the route was installed in the kernel, but not
necessarily in hardware.
The asynchronous nature of route installation in hardware can lead to a
routing daemon advertising a route before it was actually installed in
hardware. This can result in packet loss or mis-routed packets until the
route is installed in hardware.
To avoid such cases, previous patch set added the ability to emit
RTM_NEWROUTE notifications whenever RTM_F_OFFLOAD/RTM_F_TRAP flags
are changed, this behavior is controlled by sysctl.
With the above mentioned behavior, it is possible to know from user-space
if the route was offloaded, but if the offload fails there is no indication
to user-space. Following a failure, a routing daemon will wait indefinitely
for a notification that will never come.
This patch adds an "offload_failed" indication to IPv4 routes, so that
users will have better visibility into the offload process.
'struct fib_alias', and 'struct fib_rt_info' are extended with new field
that indicates if route offload failed. Note that the new field is added
using unused bit and therefore there is no need to increase structs size.
Signed-off-by: Amit Cohen <amcohen@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit fixes the errores reported when building for powerpc:
ERROR: modpost: "ip6_dst_check" [vmlinux] is a static EXPORT_SYMBOL
ERROR: modpost: "ipv4_dst_check" [vmlinux] is a static EXPORT_SYMBOL
ERROR: modpost: "ipv4_mtu" [vmlinux] is a static EXPORT_SYMBOL
ERROR: modpost: "ip6_mtu" [vmlinux] is a static EXPORT_SYMBOL
Fixes: f67fbeaebd ("net: use indirect call helpers for dst_mtu")
Fixes: bbd807dfbf ("net: indirect call helpers for ipv4/ipv6 dst_check functions")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Brian Vazquez <brianvv@google.com>
Link: https://lore.kernel.org/r/20210204181839.558951-2-brianvv@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This patch avoids the indirect call for the common case:
ip6_dst_check and ipv4_dst_check
Signed-off-by: Brian Vazquez <brianvv@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This patch avoids the indirect call for the common case:
ip6_mtu and ipv4_mtu
Signed-off-by: Brian Vazquez <brianvv@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When inet_rtm_getroute() was converted to use the RCU variants of
ip_route_input() and ip_route_output_key(), the TOS parameters
stopped being masked with IPTOS_RT_MASK before doing the route lookup.
As a result, "ip route get" can return a different route than what
would be used when sending real packets.
For example:
$ ip route add 192.0.2.11/32 dev eth0
$ ip route add unreachable 192.0.2.11/32 tos 2
$ ip route get 192.0.2.11 tos 2
RTNETLINK answers: No route to host
But, packets with TOS 2 (ECT(0) if interpreted as an ECN bit) would
actually be routed using the first route:
$ ping -c 1 -Q 2 192.0.2.11
PING 192.0.2.11 (192.0.2.11) 56(84) bytes of data.
64 bytes from 192.0.2.11: icmp_seq=1 ttl=64 time=0.173 ms
--- 192.0.2.11 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.173/0.173/0.173/0.000 ms
This patch re-applies IPTOS_RT_MASK in inet_rtm_getroute(), to
return results consistent with real route lookups.
Fixes: 3765d35ed8 ("net: ipv4: Convert inet_rtm_getroute to rcu versions of route lookup")
Signed-off-by: Guillaume Nault <gnault@redhat.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/b2d237d08317ca55926add9654a48409ac1b8f5b.1606412894.git.gnault@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This patch adds an IPv4 routes encapsulation attribute
to the result of netlink RTM_GETROUTE requests
(e.g. ip route get 192.0.2.1).
Signed-off-by: Oliver Herms <oliver.peter.herms@gmail.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20201113085517.GA1307262@tws
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The disable_policy and disable_xfrm are a per-interface sysctl to
disable IPsec policy or encryption on an interface. However, while a
"all" variant is exposed, it was a noop since it was never evaluated.
We use the usual "or" logic for this kind of sysctls.
Signed-off-by: Vincent Bernat <vincent@bernat.ch>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Minor conflicts in net/mptcp/protocol.h and
tools/testing/selftests/net/Makefile.
In both cases code was added on both sides in the same place
so just keep both.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Tobias reported regressions in IPsec tests following the patch
referenced by the Fixes tag below. The root cause is dropping the
reset of the flowi4_oif after the fib_lookup. Apparently it is
needed for xfrm cases, so restore the oif update to ip_route_output_flow
right before the call to xfrm_lookup_route.
Fixes: 2fbc6e89b2 ("ipv4: Update exception handling for multipath routes via same device")
Reported-by: Tobias Brunner <tobias@strongswan.org>
Signed-off-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Two minor conflicts:
1) net/ipv4/route.c, adding a new local variable while
moving another local variable and removing it's
initial assignment.
2) drivers/net/dsa/microchip/ksz9477.c, overlapping changes.
One pretty prints the port mode differently, whilst another
changes the driver to try and obtain the port mode from
the port node rather than the switch node.
Signed-off-by: David S. Miller <davem@davemloft.net>
Kfir reported that pmtu exceptions are not created properly for
deployments where multipath routes use the same device.
After some digging I see 2 compounding problems:
1. ip_route_output_key_hash_rcu is updating the flowi4_oif *after*
the route lookup. This is the second use case where this has
been a problem (the first is related to use of vti devices with
VRF). I can not find any reason for the oif to be changed after the
lookup; the code goes back to the start of git. It does not seem
logical so remove it.
2. fib_lookups for exceptions do not call fib_select_path to handle
multipath route selection based on the hash.
The end result is that the fib_lookup used to add the exception
always creates it based using the first leg of the route.
An example topology showing the problem:
| host1
+------+
| eth0 | .209
+------+
|
+------+
switch | br0 |
+------+
|
+---------+---------+
| host2 | host3
+------+ +------+
| eth0 | .250 | eth0 | 192.168.252.252
+------+ +------+
+-----+ +-----+
| vti | .2 | vti | 192.168.247.3
+-----+ +-----+
\ /
=================================
tunnels
192.168.247.1/24
for h in host1 host2 host3; do
ip netns add ${h}
ip -netns ${h} link set lo up
ip netns exec ${h} sysctl -wq net.ipv4.ip_forward=1
done
ip netns add switch
ip -netns switch li set lo up
ip -netns switch link add br0 type bridge stp 0
ip -netns switch link set br0 up
for n in 1 2 3; do
ip -netns switch link add eth-sw type veth peer name eth-h${n}
ip -netns switch li set eth-h${n} master br0 up
ip -netns switch li set eth-sw netns host${n} name eth0
done
ip -netns host1 addr add 192.168.252.209/24 dev eth0
ip -netns host1 link set dev eth0 up
ip -netns host1 route add 192.168.247.0/24 \
nexthop via 192.168.252.250 dev eth0 nexthop via 192.168.252.252 dev eth0
ip -netns host2 addr add 192.168.252.250/24 dev eth0
ip -netns host2 link set dev eth0 up
ip -netns host2 addr add 192.168.252.252/24 dev eth0
ip -netns host3 link set dev eth0 up
ip netns add tunnel
ip -netns tunnel li set lo up
ip -netns tunnel li add br0 type bridge
ip -netns tunnel li set br0 up
for n in $(seq 11 20); do
ip -netns tunnel addr add dev br0 192.168.247.${n}/24
done
for n in 2 3
do
ip -netns tunnel link add vti${n} type veth peer name eth${n}
ip -netns tunnel link set eth${n} mtu 1360 master br0 up
ip -netns tunnel link set vti${n} netns host${n} mtu 1360 up
ip -netns host${n} addr add dev vti${n} 192.168.247.${n}/24
done
ip -netns tunnel ro add default nexthop via 192.168.247.2 nexthop via 192.168.247.3
ip netns exec host1 ping -M do -s 1400 -c3 -I 192.168.252.209 192.168.247.11
ip netns exec host1 ping -M do -s 1400 -c3 -I 192.168.252.209 192.168.247.15
ip -netns host1 ro ls cache
Before this patch the cache always shows exceptions against the first
leg in the multipath route; 192.168.252.250 per this example. Since the
hash has an initial random seed, you may need to vary the final octet
more than what is listed. In my tests, using addresses between 11 and 19
usually found 1 that used both legs.
With this patch, the cache will have exceptions for both legs.
Fixes: 4895c771c7 ("ipv4: Add FIB nexthop exceptions")
Reported-by: Kfir Itzhak <mastertheknife@gmail.com>
Signed-off-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
flowi4_multipath_hash was added by the commit referenced below for
tunnels. Unfortunately, the patch did not initialize the new field
for several fast path lookups that do not initialize the entire flow
struct to 0. Fix those locations. Currently, flowi4_multipath_hash
is random garbage and affects the hash value computed by
fib_multipath_hash for multipath selection.
Fixes: 24ba14406c ("route: Add multipath_hash in flowi_common to make user-define hash")
Signed-off-by: David Ahern <dsahern@gmail.com>
Cc: wenxu <wenxu@ucloud.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>
This is a pure codestyle cleanup patch. No functional change intended.
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This is a pure codestyle cleanup patch. Also add a blank line after
declarations as warned by checkpatch.pl.
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When mtu is locked, we should not obtain ipv4 mtu as we return immediately
in this case and leave acquired ipv4 mtu unused.
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently, processes sending traffic to a local bridge with an
encapsulation device as a port don't get ICMP errors if they exceed
the PMTU of the encapsulated link.
David Ahern suggested this as a hack, but it actually looks like
the correct solution: when we update the PMTU for a given destination
by means of updating or creating a route exception, the encapsulation
might trigger this because of PMTU discovery happening either on the
encapsulation device itself, or its lower layer. This happens on
bridged encapsulations only.
The output interface shouldn't matter, because we already have a
valid destination. Drop the output interface restriction from the
associated route lookup.
For UDP tunnels, we will now have a route exception created for the
encapsulation itself, with a MTU value reflecting its headroom, which
allows a bridge forwarding IP packets originated locally to deliver
errors back to the sending socket.
The behaviour is now consistent with IPv6 and verified with selftests
pmtu_ipv{4,6}_br_{geneve,vxlan}{4,6}_exception introduced later in
this series.
v2:
- reset output interface only for bridge ports (David Ahern)
- add and use netif_is_any_bridge_port() helper (David Ahern)
Suggested-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We can't cast sk_buff to rtable by (struct rtable *)hint. Use skb_rtable().
Fixes: 02b2494161 ("ipv4: use dst hint for ipv4 list receive")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The MSCC bug fix in 'net' had to be slightly adjusted because the
register accesses are done slightly differently in net-next.
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit adb03115f4 ("net: get rid of an signed integer overflow in ip_idents_reserve()")
used atomic_cmpxchg to replace "atomic_add_return" inside the function
"ip_idents_reserve". The reason was to avoid UBSAN warning.
However, this change has caused performance degrade and in GCC-8,
fno-strict-overflow is now mapped to -fwrapv -fwrapv-pointer
and signed integer overflow is now undefined by default at all
optimization levels[1]. Moreover, it was a bug in UBSAN vs -fwrapv
/-fno-strict-overflow, so Let's revert it safely.
[1] https://gcc.gnu.org/gcc-8/changes.html
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Suggested-by: Eric Dumazet <edumazet@google.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Jiri Pirko <jiri@resnulli.us>
Cc: Arvind Sankar <nivedita@alum.mit.edu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jiong Wang <jiongwang@huawei.com>
Signed-off-by: Yuqi Jin <jinyuqi@huawei.com>
Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Move the bpf verifier trace check into the new switch statement in
HEAD.
Resolve the overlapping changes in hinic, where bug fixes overlap
the addition of VF support.
Signed-off-by: David S. Miller <davem@davemloft.net>
In commit b406472b5a ("net: ipv4: avoid mixed n_redirects and
rate_tokens usage") I missed the fact that a 0 'rate_tokens' will
bypass the backoff algorithm.
Since rate_tokens is cleared after a redirect silence, and never
incremented on redirects, if the host keeps receiving packets
requiring redirect it will reply ignoring the backoff.
Additionally, the 'rate_last' field will be updated with the
cadence of the ingress packet requiring redirect. If that rate is
high enough, that will prevent the host from generating any
other kind of ICMP messages
The check for a zero 'rate_tokens' value was likely a shortcut
to avoid the more complex backoff algorithm after a redirect
silence period. Address the issue checking for 'n_redirects'
instead, which is incremented on successful redirect, and
does not interfere with other ICMP replies.
Fixes: b406472b5a ("net: ipv4: avoid mixed n_redirects and rate_tokens usage")
Reported-and-tested-by: Colin Walters <walters@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Instead of having all the sysctl handlers deal with user pointers, which
is rather hairy in terms of the BPF interaction, copy the input to and
from userspace in common code. This also means that the strings are
always NUL-terminated by the common code, making the API a little bit
safer.
As most handler just pass through the data to one of the common handlers
a lot of the changes are mechnical.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Previous changes to the IP routing code have removed all the
tests for the DS_HOST route flag.
Remove the flags and all the code that sets it.
Signed-off-by: David Laight <david.laight@aculab.com>
Acked-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The Bareudp tunnel module provides a generic L3 encapsulation
tunnelling module for tunnelling different protocols like MPLS,
IP,NSH etc inside a UDP tunnel.
Signed-off-by: Martin Varghese <martin.varghese@nokia.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
if seq_file .next fuction does not change position index,
read after some lseek can generate unexpected output.
https://bugzilla.kernel.org/show_bug.cgi?id=206283
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When performing L3 offload, routes and nexthops are usually programmed
into two different tables in the underlying device. Therefore, the fact
that a nexthop resides in hardware does not necessarily mean that all
the associated routes also reside in hardware and vice-versa.
While the kernel can signal to user space the presence of a nexthop in
hardware (via 'RTNH_F_OFFLOAD'), it does not have a corresponding flag
for routes. In addition, the fact that a route resides in hardware does
not necessarily mean that the traffic is offloaded. For example,
unreachable routes (i.e., 'RTN_UNREACHABLE') are programmed to trap
packets to the CPU so that the kernel will be able to generate the
appropriate ICMP error packet.
This patch adds an "offload" and "trap" indications to IPv4 routes, so
that users will have better visibility into the offload process.
'struct fib_alias' is extended with two new fields that indicate if the
route resides in hardware or not and if it is offloading traffic from
the kernel or trapping packets to it. Note that the new fields are added
in the 6 bytes hole and therefore the struct still fits in a single
cache line [1].
Capable drivers are expected to invoke fib_alias_hw_flags_set() with the
route's key in order to set the flags.
The indications are dumped to user space via a new flags (i.e.,
'RTM_F_OFFLOAD' and 'RTM_F_TRAP') in the 'rtm_flags' field in the
ancillary header.
v2:
* Make use of 'struct fib_rt_info' in fib_alias_hw_flags_set()
[1]
struct fib_alias {
struct hlist_node fa_list; /* 0 16 */
struct fib_info * fa_info; /* 16 8 */
u8 fa_tos; /* 24 1 */
u8 fa_type; /* 25 1 */
u8 fa_state; /* 26 1 */
u8 fa_slen; /* 27 1 */
u32 tb_id; /* 28 4 */
s16 fa_default; /* 32 2 */
u8 offload:1; /* 34: 0 1 */
u8 trap:1; /* 34: 1 1 */
u8 unused:6; /* 34: 2 1 */
/* XXX 5 bytes hole, try to pack */
struct callback_head rcu __attribute__((__aligned__(8))); /* 40 16 */
/* size: 56, cachelines: 1, members: 12 */
/* sum members: 50, holes: 1, sum holes: 5 */
/* sum bitfield members: 8 bits (1 bytes) */
/* forced alignments: 1, forced holes: 1, sum forced holes: 5 */
/* last cacheline: 56 bytes */
} __attribute__((__aligned__(8)));
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
fib_dump_info() is used to prepare RTM_{NEW,DEL}ROUTE netlink messages
using the passed arguments. Currently, the function takes 11 arguments,
6 of which are attributes of the route being dumped (e.g., prefix, TOS).
The next patch will need the function to also dump to user space an
indication if the route is present in hardware or not. Instead of
passing yet another argument, change the function to take a struct
containing the different route attributes.
v2:
* Name last argument of fib_dump_info()
* Move 'struct fib_rt_info' to include/net/ip_fib.h so that it could
later be passed to fib_alias_hw_flags_set()
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The MTU update code is supposed to be invoked in response to real
networking events that update the PMTU. In IPv6 PMTU update function
__ip6_rt_update_pmtu() we called dst_confirm_neigh() to update neighbor
confirmed time.
But for tunnel code, it will call pmtu before xmit, like:
- tnl_update_pmtu()
- skb_dst_update_pmtu()
- ip6_rt_update_pmtu()
- __ip6_rt_update_pmtu()
- dst_confirm_neigh()
If the tunnel remote dst mac address changed and we still do the neigh
confirm, we will not be able to update neigh cache and ping6 remote
will failed.
So for this ip_tunnel_xmit() case, _EVEN_ if the MTU is changed, we
should not be invoking dst_confirm_neigh() as we have no evidence
of successful two-way communication at this point.
On the other hand it is also important to keep the neigh reachability fresh
for TCP flows, so we cannot remove this dst_confirm_neigh() call.
To fix the issue, we have to add a new bool parameter for dst_ops.update_pmtu
to choose whether we should do neigh update or not. I will add the parameter
in this patch and set all the callers to true to comply with the previous
way, and fix the tunnel code one by one on later patches.
v5: No change.
v4: No change.
v3: Do not remove dst_confirm_neigh, but add a new bool parameter in
dst_ops.update_pmtu to control whether we should do neighbor confirm.
Also split the big patch to small ones for each area.
v2: Remove dst_confirm_neigh in __ip6_rt_update_pmtu.
Suggested-by: David Miller <davem@davemloft.net>
Reviewed-by: Guillaume Nault <gnault@redhat.com>
Acked-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This is alike the previous change, with some additional ipv4 specific
quirk. Even when using the route hint we still have to do perform
additional per packet checks about source address validity: a new
helper is added to wrap them.
Hints are explicitly disabled if the destination is a local broadcast,
that keeps the code simple and local broadcast are a slower path anyway.
UDP flood performances vs recvmmsg() receiver:
vanilla patched delta
Kpps Kpps %
1683 1871 +11
In the worst case scenario - each packet has a different
destination address - the performance delta is within noise
range.
v3 -> v4:
- re-enable hints for forward
v2 -> v3:
- really fix build (sic) and hint usage check
- use fib4_has_custom_rules() helpers (David A.)
- add ip_extract_route_hint() helper (Edward C.)
- use prev skb as hint instead of copying data (Willem)
v1 -> v2:
- fix build issue with !CONFIG_IP_MULTIPLE_TABLES
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The same code which recognizes ICMP error packets is duplicated several
times. Use the icmp_is_err() and icmpv6_is_err() helpers instead, which
do the same thing.
ip_multipath_l3_keys() and tcf_nat_act() didn't check for all the error types,
assume that they should instead.
Signed-off-by: Matteo Croce <mcroce@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Jesse and Ido reported the following race condition:
<CPU A, t0> - Received packet A is forwarded and cached dst entry is
taken from the nexthop ('nhc->nhc_rth_input'). Calls skb_dst_set()
<t1> - Given Jesse has busy routers ("ingesting full BGP routing tables
from multiple ISPs"), route is added / deleted and rt_cache_flush() is
called
<CPU B, t2> - Received packet B tries to use the same cached dst entry
from t0, but rt_cache_valid() is no longer true and it is replaced in
rt_cache_route() by the newer one. This calls dst_dev_put() on the
original dst entry which assigns the blackhole netdev to 'dst->dev'
<CPU A, t3> - dst_input(skb) is called on packet A and it is dropped due
to 'dst->dev' being the blackhole netdev
There are 2 issues in the v4 routing code:
1. A per-netns counter is used to do the validation of the route. That
means whenever a route is changed in the netns, users of all routes in
the netns needs to redo lookup. v6 has an implementation of only
updating fn_sernum for routes that are affected.
2. When rt_cache_valid() returns false, rt_cache_route() is called to
throw away the current cache, and create a new one. This seems
unnecessary because as long as this route does not change, the route
cache does not need to be recreated.
To fully solve the above 2 issues, it probably needs quite some code
changes and requires careful testing, and does not suite for net branch.
So this patch only tries to add the deleted cached rt into the uncached
list, so user could still be able to use it to receive packets until
it's done.
Fixes: 95c47f9cf5 ("ipv4: call dst_dev_put() properly")
Signed-off-by: Wei Wang <weiwan@google.com>
Reported-by: Ido Schimmel <idosch@idosch.org>
Reported-by: Jesse Hathaway <jesse@mbuki-mvuki.org>
Tested-by: Jesse Hathaway <jesse@mbuki-mvuki.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Cc: David Ahern <dsahern@gmail.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
...instead of -EINVAL. An issue was found with older kernel versions
while unplugging a NFS client with pending RPCs, and the wrong error
code here prevented it from recovering once link is back up with a
configured address.
Incidentally, this is not an issue anymore since commit 4f8943f808
("SUNRPC: Replace direct task wakeups from softirq context"), included
in 5.2-rc7, had the effect of decoupling the forwarding of this error
by using SO_ERROR in xs_wake_error(), as pointed out by Benjamin
Coddington.
To the best of my knowledge, this isn't currently causing any further
issue, but the error code doesn't look appropriate anyway, and we
might hit this in other paths as well.
In detail, as analysed by Gonzalo Siero, once the route is deleted
because the interface is down, and can't be resolved and we return
-EINVAL here, this ends up, courtesy of inet_sk_rebuild_header(),
as the socket error seen by tcp_write_err(), called by
tcp_retransmit_timer().
In turn, tcp_write_err() indirectly calls xs_error_report(), which
wakes up the RPC pending tasks with a status of -EINVAL. This is then
seen by call_status() in the SUN RPC implementation, which aborts the
RPC call calling rpc_exit(), instead of handling this as a
potentially temporary condition, i.e. as a timeout.
Return -EINVAL only if the input parameters passed to
ip_route_output_key_hash_rcu() are actually invalid (this is the case
if the specified source address is multicast, limited broadcast or
all zeroes), but return -ENETUNREACH in all cases where, at the given
moment, the given source address doesn't allow resolving the route.
While at it, drop the initialisation of err to -ENETUNREACH, which
was added to __ip_route_output_key() back then by commit
0315e38270 ("net: Fix behaviour of unreachable, blackhole and
prohibit routes"), but actually had no effect, as it was, and is,
overwritten by the fib_lookup() return code assignment, and anyway
ignored in all other branches, including the if (fl4->saddr) one:
I find this rather confusing, as it would look like -ENETUNREACH is
the "default" error, while that statement has no effect.
Also note that after commit fc75fc8339 ("ipv4: dont create routes
on down devices"), we would get -ENETUNREACH if the device is down,
but -EINVAL if the source address is specified and we can't resolve
the route, and this appears to be rather inconsistent.
Reported-by: Stefan Walter <walteste@inf.ethz.ch>
Analysed-by: Benjamin Coddington <bcodding@redhat.com>
Analysed-by: Gonzalo Siero <gsierohu@redhat.com>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Since commit c09551c6ff ("net: ipv4: use a dedicated counter
for icmp_v4 redirect packets") we use 'n_redirects' to account
for redirect packets, but we still use 'rate_tokens' to compute
the redirect packets exponential backoff.
If the device sent to the relevant peer any ICMP error packet
after sending a redirect, it will also update 'rate_token' according
to the leaking bucket schema; typically 'rate_token' will raise
above BITS_PER_LONG and the redirect packets backoff algorithm
will produce undefined behavior.
Fix the issue using 'n_redirects' to compute the exponential backoff
in ip_rt_send_redirect().
Note that we still clear rate_tokens after a redirect silence period,
to avoid changing an established behaviour.
The root cause predates git history; before the mentioned commit in
the critical scenario, the kernel stopped sending redirects, after
the mentioned commit the behavior more randomic.
Reported-by: Xiumei Mu <xmu@redhat.com>
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Fixes: c09551c6ff ("net: ipv4: use a dedicated counter for icmp_v4 redirect packets")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Julian noted that rt_uses_gateway has a more subtle use than 'is gateway
set':
https://lore.kernel.org/netdev/alpine.LFD.2.21.1909151104060.2546@ja.home.ssi.bg/
Revert that part of the commit referenced in the Fixes tag.
Currently, there are no u8 holes in 'struct rtable'. There is a 4-byte hole
in the second cacheline which contains the gateway declaration. So move
rt_gw_family down to the gateway declarations since they are always used
together, and then re-use that u8 for rt_uses_gateway. End result is that
rtable size is unchanged.
Fixes: 1550c17193 ("ipv4: Prepare rtable for IPv6 gateway")
Reported-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David Ahern <dsahern@gmail.com>
Reviewed-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
An excerpt from netlink(7) man page,
In multipart messages (multiple nlmsghdr headers with associated payload
in one byte stream) the first and all following headers have the
NLM_F_MULTI flag set, except for the last header which has the type
NLMSG_DONE.
but, after (ee28906) there is a missing NLM_F_MULTI flag in the middle of a
FIB dump. The result is user space applications following above man page
excerpt may get confused and may stop parsing msg believing something went
wrong.
In the golang netlink lib [0] the library logic stops parsing believing the
message is not a multipart message. Found this running Cilium[1] against
net-next while adding a feature to auto-detect routes. I noticed with
multiple route tables we no longer could detect the default routes on net
tree kernels because the library logic was not returning them.
Fix this by handling the fib_dump_info_fnhe() case the same way the
fib_dump_info() handles it by passing the flags argument through the
call chain and adding a flags argument to rt_fill_info().
Tested with Cilium stack and auto-detection of routes works again. Also
annotated libs to dump netlink msgs and inspected NLM_F_MULTI and
NLMSG_DONE flags look correct after this.
Note: In inet_rtm_getroute() pass rt_fill_info() '0' for flags the same
as is done for fib_dump_info() so this looks correct to me.
[0] https://github.com/vishvananda/netlink/
[1] https://github.com/cilium/
Fixes: ee28906fd7 ("ipv4: Dump route exceptions if requested")
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit 363887a2cd ("ipv4: Support multipath hashing on inner IP pkts
for GRE tunnel") supports multipath policy value of 2, Layer 3 or inner
Layer 3 if present, but it only considers inner IPv4. There is a use
case of IPv6 is tunneled by IPv4 GRE, thus add the ability to hash on
inner IPv6 addresses.
Fixes: 363887a2cd ("ipv4: Support multipath hashing on inner IP pkts for GRE tunnel")
Signed-off-by: Stephen Suryaputra <ssuryaextr@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Both ip_neigh_gw4() and ip_neigh_gw6() can return either a valid pointer
or an error pointer, but the code currently checks that the pointer is
not NULL.
Fix this by checking that the pointer is not an error pointer, as this
can result in a NULL pointer dereference [1]. Specifically, I believe
that what happened is that ip_neigh_gw4() returned '-EINVAL'
(0xffffffffffffffea) to which the offset of 'refcnt' (0x70) was added,
which resulted in the address 0x000000000000005a.
[1]
BUG: KASAN: null-ptr-deref in refcount_inc_not_zero_checked+0x6e/0x180
Read of size 4 at addr 000000000000005a by task swapper/2/0
CPU: 2 PID: 0 Comm: swapper/2 Not tainted 5.2.0-rc6-custom-reg-179657-gaa32d89 #396
Hardware name: Mellanox Technologies Ltd. MSN2010/SA002610, BIOS 5.6.5 08/24/2017
Call Trace:
<IRQ>
dump_stack+0x73/0xbb
__kasan_report+0x188/0x1ea
kasan_report+0xe/0x20
refcount_inc_not_zero_checked+0x6e/0x180
ipv4_neigh_lookup+0x365/0x12c0
__neigh_update+0x1467/0x22f0
arp_process.constprop.6+0x82e/0x1f00
__netif_receive_skb_one_core+0xee/0x170
process_backlog+0xe3/0x640
net_rx_action+0x755/0xd90
__do_softirq+0x29b/0xae7
irq_exit+0x177/0x1c0
smp_apic_timer_interrupt+0x164/0x5e0
apic_timer_interrupt+0xf/0x20
</IRQ>
Fixes: 5c9f7c1dfc ("ipv4: Add helpers for neigh lookup for nexthop")
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reported-by: Shalom Toledo <shalomt@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Use blackhole_netdev instead of 'lo' device with lower MTU when marking
dst "dead".
Signed-off-by: Mahesh Bandewar <maheshb@google.com>
Tested-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Tools such as vpnc try to flush routes when run inside network
namespaces by writing 1 into /proc/sys/net/ipv4/route/flush. This
currently does not work because flush is not enabled in non-initial
network namespaces.
Since routes are per network namespace it is safe to enable
/proc/sys/net/ipv4/route/flush in there.
Link: https://github.com/lxc/lxd/issues/4257
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The new route handling in ip_mc_finish_output() from 'net' overlapped
with the new support for returning congestion notifications from BPF
programs.
In order to handle this I had to take the dev_loopback_xmit() calls
out of the switch statement.
The aquantia driver conflicts were simple overlapping changes.
Signed-off-by: David S. Miller <davem@davemloft.net>
Multicast or broadcast egress packets have rt_iif set to the oif. These
packets might be recirculated back as input and lookup to the raw
sockets may fail because they are bound to the incoming interface
(skb_iif). If rt_iif is not zero, during the lookup, inet_iif() function
returns rt_iif instead of skb_iif. Hence, the lookup fails.
v2: Make it non vrf specific (David Ahern). Reword the changelog to
reflect it.
Signed-off-by: Stephen Suryaputra <ssuryaextr@gmail.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Since commit 4895c771c7 ("ipv4: Add FIB nexthop exceptions."), cached
exception routes are stored as a separate entity, so they are not dumped
on a FIB dump, even if the RTM_F_CLONED flag is passed.
This implies that the command 'ip route list cache' doesn't return any
result anymore.
If the RTM_F_CLONED is passed, and strict checking requested, retrieve
nexthop exception routes and dump them. If no strict checking is
requested, filtering can't be performed consistently: dump everything in
that case.
With this, we need to add an argument to the netlink callback in order to
track how many entries were already dumped for the last leaf included in
a partial netlink dump.
A single additional argument is sufficient, even if we traverse logically
nested structures (nexthop objects, hash table buckets, bucket chains): it
doesn't matter if we stop in the middle of any of those, because they are
always traversed the same way. As an example, s_i values in [], s_fa
values in ():
node (fa) #1 [1]
nexthop #1
bucket #1 -> #0 in chain (1)
bucket #2 -> #0 in chain (2) -> #1 in chain (3) -> #2 in chain (4)
bucket #3 -> #0 in chain (5) -> #1 in chain (6)
nexthop #2
bucket #1 -> #0 in chain (7) -> #1 in chain (8)
bucket #2 -> #0 in chain (9)
--
node (fa) #2 [2]
nexthop #1
bucket #1 -> #0 in chain (1) -> #1 in chain (2)
bucket #2 -> #0 in chain (3)
it doesn't matter if we stop at (3), (4), (7) for "node #1", or at (2)
for "node #2": walking flattens all that.
It would even be possible to drop the distinction between the in-tree
(s_i) and in-node (s_fa) counter, but a further improvement might
advise against this. This is only as accurate as the existing tracking
mechanism for leaves: if a partial dump is restarted after exceptions
are removed or expired, we might skip some non-dumped entries.
To improve this, we could attach a 'sernum' attribute (similar to the
one used for IPv6) to nexthop entities, and bump this counter whenever
exceptions change: having a distinction between the two counters would
make this more convenient.
Listing of exception routes (modified routes pre-3.5) was tested against
these versions of kernel and iproute2:
iproute2
kernel 4.14.0 4.15.0 4.19.0 5.0.0 5.1.0
3.5-rc4 + + + + +
4.4
4.9
4.14
4.15
4.19
5.0
5.1
fixed + + + + +
v7:
- Move loop over nexthop objects to route.c, and pass struct fib_info
and table ID to it, not a struct fib_alias (suggested by David Ahern)
- While at it, note that the NULL check on fa->fa_info is redundant,
and the check on RTNH_F_DEAD is also not consistent with what's done
with regular route listing: just keep it for nhc_flags
- Rename entry point function for dumping exceptions to
fib_dump_info_fnhe(), and rearrange arguments for consistency with
fib_dump_info()
- Rename fnhe_dump_buckets() to fnhe_dump_bucket() and make it handle
one bucket at a time
- Expand commit message to describe why we can have a single "skip"
counter for all exceptions stored in bucket chains in nexthop objects
(suggested by David Ahern)
v6:
- Rebased onto net-next
- Loop over nexthop paths too. Move loop over fnhe buckets to route.c,
avoids need to export rt_fill_info() and to touch exceptions from
fib_trie.c. Pass NULL as flow to rt_fill_info(), it now allows that
(suggested by David Ahern)
Fixes: 4895c771c7 ("ipv4: Add FIB nexthop exceptions.")
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
