net/core: dev_forward_skb() should clear skb_iif

While investigating another bug, I found that the code on the incoming path in __netif_receive_skb will only set skb->skb_iif if it is already 0. When dev_forward_skb() is used in the case of interfaces like veth, skb_iif may already have been set. Making dev_forward_skb() cause the packet to look like a newly received packet would seem to the the correct behaviour here, as otherwise the wrong incoming interface can be reported for such a packet.

---
 net/core/dev.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

index 452db70..723a406 100644
@@ -1597,6 +1597,7 @@ int dev_forward_skb(struct net_device *dev, struct sk_buff *skb)
 		kfree_skb(skb);
 		return NET_RX_DROP;
 	}
+	skb->skb_iif = 0;
 	skb_set_dev(skb, dev);
 	skb->tstamp.tv64 = 0;
 	skb->pkt_type = PACKET_HOST;

1.7.4.1


-- 
"Thought is the essence of where you are now."

From: Benjamin LaHaise <[email protected]>
Date: Tue, 27 Mar 2012 21:55:44 -0400

Applied.