Hello,

On Thu, 27 Jun 2013, Timo Teräs wrote:

Commit d2d68ba9 (ipv4: Cache input routes in fib_info nexthops)
assmued that "locally destined, and routed packets, never trigger
PMTU events or redirects that will be processed by us".

However, it seems that tunnel devices do trigger PMTU events in certain
cases. At least ip_gre, ip6_gre, sit, and ipip do use the inner flow's
skb_dst(skb)->ops->update_pmtu to propage mtu information from the
outer flows. These can cause the inner flow mtu to be decreased. If
next hop exceptions are not consulted for pmtu, IP fragmentation will
not be done properly for these routes.

It also seems that we really need to have the PMTU information always
for netfilter TCPMSS clamp-to-pmtu feature to work properly.

So for the time being, cache separate copies of input routes for
each next hop exception.

Signed-off-by: Timo Teräs <redacted>

	Looks good to me

Reviewed-by: Julian Anastasov <ja@ssi.bg>

---
Seems that the previous send was marked as RFC, and got no review
comments. No alternate patches seem to have been committed either.

I'm resending now without RFC tag, and rebased against current
net-next. I've been using this locally for several weeks and have
not found any problems, and this does fix the two regression bugs
mentioned above.

Regards

--
Julian Anastasov [off-list ref]