From 2ffae99d1fac272952b5a395759823717760ce37 Mon Sep 17 00:00:00 2001 From: Timo Teräs Date: Thu, 27 Jun 2013 10:27:05 +0300 Subject: ipv4: use next hop exceptions also for input routes MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Reviewed-by: Julian Anastasov Signed-off-by: David S. Miller --- include/net/ip_fib.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'include/net/ip_fib.h') diff --git a/include/net/ip_fib.h b/include/net/ip_fib.h index 44424e9dab2a..aac85534d7b5 100644 --- a/include/net/ip_fib.h +++ b/include/net/ip_fib.h @@ -56,7 +56,8 @@ struct fib_nh_exception { u32 fnhe_pmtu; __be32 fnhe_gw; unsigned long fnhe_expires; - struct rtable __rcu *fnhe_rth; + struct rtable __rcu *fnhe_rth_input; + struct rtable __rcu *fnhe_rth_output; unsigned long fnhe_stamp; }; -- cgit