On Wed, Jun 06, 2018 at 02:31:58PM +0200, Jason A. Donenfeld wrote:
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 Cc: stable@vger.kernel.org
Acked-by: Pablo Neira Ayuso pablo@netfilter.org
Upstream patch is:
commit 2a79fd3908acd88e6cb0e620c314d7b1fee56a02 Author: Jason A. Donenfeld Jason@zx2c4.com Date: Wed May 30 20:43:15 2018 +0200
This is backport for -stable 4.16.x.
net/netfilter/nf_flow_table_ip.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/net/netfilter/nf_flow_table_ip.c b/net/netfilter/nf_flow_table_ip.c index 82451b7..15ed913 100644 --- 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, struct sk_buff *skb, 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, struct sk_buff *skb, 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, struct sk_buff *skb, 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, struct sk_buff *skb, 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;