From: Steffen Klassert Date: Sun, 7 Oct 2012 22:48:18 +0000 (+0000) Subject: ipv4: Don't create nh exeption when the device mtu is smaller than the reported pmtu X-Git-Url: https://openfabrics.org/gitweb/?a=commitdiff_plain;h=7f92d334ba19a0d8e96f8f8f092219553367d921;p=~shefty%2Frdma-dev.git ipv4: Don't create nh exeption when the device mtu is smaller than the reported pmtu When a local tool like tracepath tries to send packets bigger than the device mtu, we create a nh exeption and set the pmtu to device mtu. The device mtu does not expire, so check if the device mtu is smaller than the reported pmtu and don't crerate a nh exeption in that case. Signed-off-by: Steffen Klassert Signed-off-by: David S. Miller --- diff --git a/net/ipv4/route.c b/net/ipv4/route.c index 90ba8358a89..741df67a81e 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -909,6 +909,9 @@ static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu) struct dst_entry *dst = &rt->dst; struct fib_result res; + if (dst->dev->mtu < mtu) + return; + if (mtu < ip_rt_min_pmtu) mtu = ip_rt_min_pmtu;