From: Herbert Xu <herbert@gondor.apana.org.au>
Date: Tue, 28 Apr 2015 03:43:15 +0000 (+0800)
Subject: route: Use ipv4_mtu instead of raw rt_pmtu
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=cb6ccf09d6b94bec4def1ac5cf4678d12b216474;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git

route: Use ipv4_mtu instead of raw rt_pmtu

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>
---

diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index a78540f28276..bff62fc87b8e 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -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)