From f839a6c92504cff92a10f522cf686b51ff18dd35 Mon Sep 17 00:00:00 2001 From: Ido Schimmel Date: Tue, 4 Dec 2018 08:15:11 +0000 Subject: [PATCH] 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 Signed-off-by: David S. Miller --- net/ipv4/ip_forward.c | 7 +++++++ net/ipv6/ip6_output.c | 7 +++++++ 2 files changed, 14 insertions(+) diff --git a/net/ipv4/ip_forward.c b/net/ipv4/ip_forward.c index 32662e9e5d21..06ee4696703c 100644 --- a/net/ipv4/ip_forward.c +++ b/net/ipv4/ip_forward.c @@ -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); diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c index ec8c235ea891..6592a39e5ec1 100644 --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -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); } -- 2.30.2