net: Do not route unicast IP packets twice

Packets marked with 'offload_l3_fwd_mark' were already forwarded by a
capable device and should not be forwarded again by the kernel.
Therefore, have the kernel consume them.

The check is performed in ip{,6}_forward_finish() in order to allow the
kernel to process such packets in ip{,6}_forward() and generate required
exceptions. For example, ICMP redirects.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Ido Schimmel 2018-12-04 08:15:11 +00:00 committed by David S. Miller
parent 875e893995
commit f839a6c925
2 changed files with 14 additions and 0 deletions

View File

@ -69,6 +69,13 @@ static int ip_forward_finish(struct net *net, struct sock *sk, struct sk_buff *s
__IP_INC_STATS(net, IPSTATS_MIB_OUTFORWDATAGRAMS);
__IP_ADD_STATS(net, IPSTATS_MIB_OUTOCTETS, skb->len);
#ifdef CONFIG_NET_SWITCHDEV
if (skb->offload_l3_fwd_mark) {
consume_skb(skb);
return 0;
}
#endif
if (unlikely(opt->optlen))
ip_forward_options(skb);

View File

@ -378,6 +378,13 @@ static inline int ip6_forward_finish(struct net *net, struct sock *sk,
__IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTFORWDATAGRAMS);
__IP6_ADD_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTOCTETS, skb->len);
#ifdef CONFIG_NET_SWITCHDEV
if (skb->offload_l3_fwd_mark) {
consume_skb(skb);
return 0;
}
#endif
return dst_output(net, sk, skb);
}