path: root/net
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authorSteffen Klassert <steffen.klassert@secunet.com>2011-11-23 02:14:50 +0000
committerDavid S. Miller <davem@davemloft.net>2011-11-26 14:29:52 -0500
commit261663b0ee2ee8e3947f4c11c1a08be18cd2cea1 (patch)
tree12cf5a46c7c5ec2f615826b975fa85473e054bd7 /net
parentb8400f3718a11c9b0ca400705cddf94f3132c1c3 (diff)
ipv4: Don't use the cached pmtu informations for input routes
The pmtu informations on the inetpeer are visible for output and input routes. On packet forwarding, we might propagate a learned pmtu to the sender. As we update the pmtu informations of the inetpeer on demand, the original sender of the forwarded packets might never notice when the pmtu to that inetpeer increases. So use the mtu of the outgoing device on packet forwarding instead of the pmtu to the final destination. Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
1 files changed, 2 insertions, 2 deletions
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 11d1b2080a16..fb47c8f0cd86 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1816,15 +1816,15 @@ static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
static unsigned int ipv4_mtu(const struct dst_entry *dst)
+ const struct rtable *rt = (const struct rtable *) dst;
unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
- if (mtu)
+ if (mtu && rt_is_output_route(rt))
return mtu;
mtu = dst->dev->mtu;
if (unlikely(dst_metric_locked(dst, RTAX_MTU))) {
- const struct rtable *rt = (const struct rtable *) dst;
if (rt->rt_gateway != rt->rt_dst && mtu > 576)
mtu = 576;

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