kernel: backport patch to fix dst handling for offloaded connections

Signed-off-by: Felix Fietkau <nbd@nbd.name>
This commit is contained in:
Felix Fietkau 2018-06-05 10:16:49 +02:00
parent 7d8681ccb9
commit 2f3b1dddea

View file

@ -0,0 +1,49 @@
From: "Jason A. Donenfeld" <Jason@zx2c4.com>
Date: Wed, 30 May 2018 20:43:15 +0200
Subject: [PATCH] netfilter: nf_flow_table: attach dst to skbs
Some drivers, such as vxlan and wireguard, use the skb's dst in order to
determine things like PMTU. They therefore loose functionality when flow
offloading is enabled. So, we ensure the skb has it before xmit'ing it
in the offloading path.
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
--- a/net/netfilter/nf_flow_table_ip.c
+++ b/net/netfilter/nf_flow_table_ip.c
@@ -220,7 +220,7 @@ nf_flow_offload_ip_hook(void *priv, stru
enum flow_offload_tuple_dir dir;
struct flow_offload *flow;
struct net_device *outdev;
- const struct rtable *rt;
+ struct rtable *rt;
unsigned int thoff;
struct iphdr *iph;
__be32 nexthop;
@@ -241,7 +241,7 @@ nf_flow_offload_ip_hook(void *priv, stru
dir = tuplehash->tuple.dir;
flow = container_of(tuplehash, struct flow_offload, tuplehash[dir]);
- rt = (const struct rtable *)flow->tuplehash[!dir].tuple.dst_cache;
+ rt = (struct rtable *)flow->tuplehash[!dir].tuple.dst_cache;
if (unlikely(nf_flow_exceeds_mtu(skb, flow->tuplehash[dir].tuple.mtu)) &&
(ip_hdr(skb)->frag_off & htons(IP_DF)) != 0)
@@ -264,6 +264,7 @@ nf_flow_offload_ip_hook(void *priv, stru
skb->dev = outdev;
nexthop = rt_nexthop(rt, flow->tuplehash[!dir].tuple.src_v4.s_addr);
+ skb_dst_set_noref(skb, &rt->dst);
neigh_xmit(NEIGH_ARP_TABLE, outdev, &nexthop, skb);
return NF_STOLEN;
@@ -480,6 +481,7 @@ nf_flow_offload_ipv6_hook(void *priv, st
skb->dev = outdev;
nexthop = rt6_nexthop(rt, &flow->tuplehash[!dir].tuple.src_v6);
+ skb_dst_set_noref(skb, &rt->dst);
neigh_xmit(NEIGH_ND_TABLE, outdev, nexthop, skb);
return NF_STOLEN;