[PATCH net-next 2/4] net: Do not route unicast IP packets twice
From: Ido Schimmel <hidden>
Date: 2018-12-04 08:15:20
Subsystem:
networking [general], networking [ipv4/ipv6], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, David Ahern, Ido Schimmel, Linus Torvalds
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 <redacted>
---
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); }
--
2.19.1