From 4ed377e36ec2f385484d12e516faf88516fad31c Mon Sep 17 00:00:00 2001 From: Hannes Frederic Sowa Date: Sat, 21 Sep 2013 06:32:34 +0200 Subject: [PATCH] net: neighbour: use source address of last enqueued packet for solicitation Currently we always use the first member of the arp_queue to determine the sender ip address of the arp packet (or in case of IPv6 - source address of the ndisc packet). This skb is fixed as long as the queue is not drained by a complete purge because of a timeout or by a successful response. If the first packet enqueued on the arp_queue is from a local application with a manually set source address and the to be discovered system does some kind of uRPF checks on the source address in the arp packet the resolving process hangs until a timeout and restarts. This hurts communication with the participating network node. This could be mitigated a bit if we use the latest enqueued skb's source address for the resolving process, which is not as static as the arp_queue's head. This change of the source address could result in better recovery of a failed solicitation. Cc: "David S. Miller" Cc: Julian Anastasov Reviewed-by: Julian Anastasov Signed-off-by: Hannes Frederic Sowa Signed-off-by: David S. Miller --- net/core/neighbour.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/core/neighbour.c b/net/core/neighbour.c index 6072610a8672..ca15f32821fb 100644 --- a/net/core/neighbour.c +++ b/net/core/neighbour.c @@ -867,7 +867,7 @@ static void neigh_invalidate(struct neighbour *neigh) static void neigh_probe(struct neighbour *neigh) __releases(neigh->lock) { - struct sk_buff *skb = skb_peek(&neigh->arp_queue); + struct sk_buff *skb = skb_peek_tail(&neigh->arp_queue); /* keep skb alive even if arp_queue overflows */ if (skb) skb = skb_copy(skb, GFP_ATOMIC); -- 2.20.1