[PATCH 1/4] ipv4: Fix pmtu propagating

[Steffen Klassert <steffen.klassert@secunet.com>]

Since commit 2c8cec5c (ipv4: Cache learned PMTU information in inetpeer)
we cache the learned pmtu informations in inetpeer and propagate these
informations with the dst_ops->check() functions. However, these functions
might not be called for udp and raw packets. As a consequence, we don't
use the learned pmtu informations in these cases. With this patch we
call dst_check() from ip_setup_cork() to propagate the pmtu informations.

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
---
 net/ipv4/ip_output.c |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)

diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 8c65633..f682437 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -1063,6 +1063,11 @@ static int ip_setup_cork(struct sock *sk, struct inet_cork *cork,
 	rt = *rtp;
 	if (unlikely(!rt))
 		return -EFAULT;
+
+	rt = (struct rtable *)dst_check(&rt->dst, 0);
+	if (!rt)
+		return -EHOSTUNREACH;
+
 	/*
 	 * We steal reference to this route, caller should not release it
 	 */
-- 
1.7.0.4