From: Eli Cooper <elicooper@gmx.com>
Date: Thu, 1 Dec 2016 02:05:11 +0000 (+0800)
Subject: ipv6: Set skb->protocol properly for local output
X-Git-Tag: v4.8.14~6
X-Git-Url: http://git.hungrycats.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e67bd82fb79d04426f8f5f8bc52c31e9fbb8b69d;p=linux

ipv6: Set skb->protocol properly for local output

commit b4e479a96fc398ccf83bb1cffb4ffef8631beaf1 upstream.

When xfrm is applied to TSO/GSO packets, it follows this path:

    xfrm_output() -> xfrm_output_gso() -> skb_gso_segment()

where skb_gso_segment() relies on skb->protocol to function properly.

This patch sets skb->protocol to ETH_P_IPV6 before dst_output() is called,
fixing a bug where GSO packets sent through an ipip6 tunnel are dropped
when xfrm is involved.

Signed-off-by: Eli Cooper <elicooper@gmx.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/net/ipv6/output_core.c b/net/ipv6/output_core.c
index 462f2a76b5c2..1d184322a7b1 100644
--- a/net/ipv6/output_core.c
+++ b/net/ipv6/output_core.c
@@ -148,6 +148,8 @@ int __ip6_local_out(struct net *net, struct sock *sk, struct sk_buff *skb)
 	ipv6_hdr(skb)->payload_len = htons(len);
 	IP6CB(skb)->nhoff = offsetof(struct ipv6hdr, nexthdr);
 
+	skb->protocol = htons(ETH_P_IPV6);
+
 	return nf_hook(NFPROTO_IPV6, NF_INET_LOCAL_OUT,
 		       net, sk, skb, NULL, skb_dst(skb)->dev,
 		       dst_output);