From aa7da9375677d31dd53ed6253f55cb19e3075811 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Sat, 7 Mar 2015 16:23:23 -0600 Subject: [PATCH] mpls: Correct the ttl decrement. According to RFC3032 section 2.4.2 packets with an outgoing ttl of 0 MUST NOT be forwarded. According to section 2.4.1 an outgoing TTL of 0 comes from an incomming TTL <= 1. Therefore any packets that is received with a ttl <= 1 should not have it's ttl decremented and forwarded. Signed-off-by: "Eric W. Biederman" Signed-off-by: David S. Miller --- net/mpls/af_mpls.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/mpls/af_mpls.c b/net/mpls/af_mpls.c index 5c99e3fc1b72..e120074157de 100644 --- a/net/mpls/af_mpls.c +++ b/net/mpls/af_mpls.c @@ -162,7 +162,7 @@ static int mpls_forward(struct sk_buff *skb, struct net_device *dev, skb_forward_csum(skb); /* Verify ttl is valid */ - if (dec.ttl <= 2) + if (dec.ttl <= 1) goto drop; dec.ttl -= 1;