ip6_tnl_encap assigns to proto transport protocol which
encapsulates inner packet, but we must pass to set_inner_ipproto
protocol of that inner packet.
Calling set_inner_ipproto after ip6_tnl_encap might break gso.
For example, in case of encapsulating ipv6 packet in fou6 packet, inner_ipproto
would be set to IPPROTO_UDP instead of IPPROTO_IPV6. This would lead to
incorrect calling sequence of gso functions:
ipv6_gso_segment -> udp6_ufo_fragment -> skb_udp_tunnel_segment ->
udp6_ufo_fragment
instead of:
ipv6_gso_segment -> udp6_ufo_fragment -> skb_udp_tunnel_segment ->
ip6ip6_gso_segment
Fixes: 6c11fbf97e69 ("ip6_tunnel: add MPLS transmit support")
Signed-off-by: Alexander Ovechkin <o...@yandex-team.ru>
---
Changes in v2:
- add Fixes line (Willem de Bruijn)
net/ipv6/ip6_tunnel.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c
index a0217e5bf3bc..648db3fe508f 100644
--- a/net/ipv6/ip6_tunnel.c
+++ b/net/ipv6/ip6_tunnel.c
@@ -1271,6 +1271,8 @@ int ip6_tnl_xmit(struct sk_buff *skb, struct net_device
*dev, __u8 dsfield,
if (max_headroom > dev->needed_headroom)
dev->needed_headroom = max_headroom;
+ skb_set_inner_ipproto(skb, proto);
+
err = ip6_tnl_encap(skb, t, &proto, fl6);
if (err)
return err;
@@ -1280,8 +1282,6 @@ int ip6_tnl_xmit(struct sk_buff *skb, struct net_device
*dev, __u8 dsfield,
ipv6_push_frag_opts(skb, &opt.ops, &proto);
}
- skb_set_inner_ipproto(skb, proto);
-
skb_push(skb, sizeof(struct ipv6hdr));
skb_reset_network_header(skb);
ipv6h = ipv6_hdr(skb);
--
2.17.1
