diff options
| author | Petr Machata <petrm@nvidia.com> | 2025-06-17 00:44:15 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-08-15 12:13:39 +0200 |
| commit | 94927ae3d5c1d65cd4148e91b9ef5482607a9bc3 (patch) | |
| tree | d116ed1fb378486043ef1d1f5b5e970d420b2cb9 | |
| parent | 443430e67868c7f7d121784de538f93fbc1d59cd (diff) | |
net: ipv6: ip6mr: Fix in/out netdev to pass to the FORWARD chain
[ Upstream commit 3365afd3abda5f6a54f4a822dad5c9314e94c3fc ]
The netfilter hook is invoked with skb->dev for input netdevice, and
vif_dev for output netdevice. However at the point of invocation, skb->dev
is already set to vif_dev, and MR-forwarded packets are reported with
in=out:
# ip6tables -A FORWARD -j LOG --log-prefix '[forw]'
# cd tools/testing/selftests/net/forwarding
# ./router_multicast.sh
# dmesg | fgrep '[forw]'
[ 1670.248245] [forw]IN=v5 OUT=v5 [...]
For reference, IPv4 MR code shows in and out as appropriate.
Fix by caching skb->dev and using the updated value for output netdev.
Fixes: 7bc570c8b4f7 ("[IPV6] MROUTE: Support multicast forwarding.")
Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://patch.msgid.link/3141ae8386fbe13fef4b793faa75e6bae58d798a.1750113335.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | net/ipv6/ip6mr.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c index 440048d609c3..68bc518500f9 100644 --- a/net/ipv6/ip6mr.c +++ b/net/ipv6/ip6mr.c @@ -2032,6 +2032,7 @@ static int ip6mr_forward2(struct net *net, struct mr_table *mrt, struct sk_buff *skb, int vifi) { struct vif_device *vif = &mrt->vif_table[vifi]; + struct net_device *indev = skb->dev; struct net_device *vif_dev; struct ipv6hdr *ipv6h; struct dst_entry *dst; @@ -2094,7 +2095,7 @@ static int ip6mr_forward2(struct net *net, struct mr_table *mrt, IP6CB(skb)->flags |= IP6SKB_FORWARDED; return NF_HOOK(NFPROTO_IPV6, NF_INET_FORWARD, - net, NULL, skb, skb->dev, vif_dev, + net, NULL, skb, indev, skb->dev, ip6mr_forward2_finish); out_free: |