[PATCH 3.19.y-ckt 152/170] ipip: Properly mark ipip GRO packets as encapsulated.

[Kamal Mostafa]

3.19.8-ckt18 -stable review patch.  If anyone has any objections, please let me know.

---8<------------------------------------------------------------

From: Jesse Gross <jesse at kernel.org>

commit b8cba75bdf6a48ea4811bbefb11a94a5c7281b68 upstream.

ipip encapsulated packets can be merged together by GRO but the result
does not have the proper GSO type set or even marked as being
encapsulated at all. Later retransmission of these packets will likely
fail if the device does not support ipip offloads. This is similar to
the issue resolved in IPv6 sit in feec0cb3
("ipv6: gro: support sit protocol").

Reported-by: Patrick Boutilier <boutilpj at ednet.ns.ca>
Fixes: 9667e9bb ("ipip: Add gro callbacks to ipip offload")
Tested-by: Patrick Boutilier <boutilpj at ednet.ns.ca>
Acked-by: Eric Dumazet <edumazet at google.com>
Signed-off-by: Jesse Gross <jesse at kernel.org>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 net/ipv4/af_inet.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index c9c28d7..35abc66 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -1433,6 +1433,13 @@ out_unlock:
 	return err;
 }
 
+static int ipip_gro_complete(struct sk_buff *skb, int nhoff)
+{
+	skb->encapsulation = 1;
+	skb_shinfo(skb)->gso_type |= SKB_GSO_IPIP;
+	return inet_gro_complete(skb, nhoff);
+}
+
 int inet_ctl_sock_create(struct sock **sk, unsigned short family,
 			 unsigned short type, unsigned char protocol,
 			 struct net *net)
@@ -1650,7 +1657,7 @@ static const struct net_offload ipip_offload = {
 	.callbacks = {
 		.gso_segment	= inet_gso_segment,
 		.gro_receive	= inet_gro_receive,
-		.gro_complete	= inet_gro_complete,
+		.gro_complete	= ipip_gro_complete,
 	},
 };
 
-- 
2.7.4