From: Michal Schmidt <mschmidt@redhat.com>
Date: Fri, 3 Sep 2010 19:57:53 -0400
Subject: [net] core: bug fix for vlan + gro issue
Message-id: <20100903195751.7750.78510.stgit@localhost6.localdomain6>
Patchwork-id: 28128
O-Subject: [RHEL5.6 BZ556476 PATCH 2/6] net: bug fix for vlan + gro issue
Bugzilla: 556476
RH-Acked-by: David S. Miller <davem@redhat.com>
RH-Acked-by: Thomas Graf <tgraf@redhat.com>

From: Ajit Khaparde <ajitkhaparde@gmail.com>

commit c4d49794ff2838038fd9756eae39c39a5a685833 upstream.

 Traffic (tcp) does not start on a vlan interface when gro is enabled.
 Even the tcp handshake was not taking place.
 This is because, the eth_type_trans call before the netif_receive_skb
 in napi_gro_finish() resets the skb->dev to napi->dev from the previously
 set vlan netdev interface. This causes the ip_route_input to drop the
 incoming packet considering it as a packet coming from a martian source.

 I could repro this on 2.6.32.7 (stable) and 2.6.33-rc7.
 With this fix, the traffic starts and the test runs fine on both vlan
 and non-vlan interfaces.

 CC: Herbert Xu <herbert@gondor.apana.org.au>
 CC: Patrick McHardy <kaber@trash.net>
 Signed-off-by: Ajit Khaparde <ajitk@serverengines.com>
 Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
 Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Adjust context for RHEL 5]

diff --git a/net/core/dev.c b/net/core/dev.c
index 1968d30..04bc9f8 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2252,7 +2252,7 @@ int napi_frags_finish(struct napi_struct *napi, struct sk_buff *skb, int ret)
 	switch (ret) {
 	case GRO_NORMAL:
 	case GRO_HELD:
-		skb->protocol = eth_type_trans(skb, napi->dev);
+		skb->protocol = eth_type_trans(skb, skb->dev);
 
 		if (ret == GRO_NORMAL)
 			return netif_receive_skb(skb);