route: Use ipv4_mtu instead of raw rt_pmtu
authorHerbert Xu <herbert@gondor.apana.org.au>
Tue, 28 Apr 2015 03:43:15 +0000 (11:43 +0800)
committerDavid S. Miller <davem@davemloft.net>
Wed, 29 Apr 2015 18:43:22 +0000 (14:43 -0400)
The commit 3cdaa5be9e81a914e633a6be7b7d2ef75b528562 ("ipv4: Don't
increase PMTU with Datagram Too Big message") broke PMTU in cases
where the rt_pmtu value has expired but is smaller than the new
PMTU value.

This obsolete rt_pmtu then prevents the new PMTU value from being
installed.

Fixes: 3cdaa5be9e81 ("ipv4: Don't increase PMTU with Datagram Too Big message")
Reported-by: Gerd v. Egidy <gerd.von.egidy@intra2net.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/ipv4/route.c

index a78540f..bff62fc 100644 (file)
@@ -962,10 +962,7 @@ static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu)
        if (dst_metric_locked(dst, RTAX_MTU))
                return;
 
-       if (dst->dev->mtu < mtu)
-               return;
-
-       if (rt->rt_pmtu && rt->rt_pmtu < mtu)
+       if (ipv4_mtu(dst) < mtu)
                return;
 
        if (mtu < ip_rt_min_pmtu)