From e6293da87fcd2cddcf53af524e622fcd4d9450f8 Mon Sep 17 00:00:00 2001 From: Julian Anastasov Date: Tue, 9 Oct 2012 13:00:47 +0000 Subject: [PATCH] netfilter: nf_conntrack: fix rt_gateway checks for H.323 helper After the change "Adjust semantics of rt->rt_gateway" (commit aca2e6f6f2) we should properly match the nexthop when destinations are directly connected because rt_gateway can be 0. The rt_gateway checks in H.323 helper try to avoid the creation of an unnecessary expectation in this call-forwarding case: http://people.netfilter.org/zhaojingmin/h323_conntrack_nat_helper/#_Toc133598073 However, the existing code fails to avoid that in many cases, see this thread: http://marc.info/?l=linux-netdev&m=135043175028620&w=2 It seems it is not trivial to know from the kernel if two hosts have to go through the firewall to communicate each other, which is the main point of the call-forwarding filter code to avoid creating unnecessary expectations. So this patch just gets things the way they were as before commit aca2e6f6f2. Signed-off-by: Julian Anastasov Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_conntrack_h323_main.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/netfilter/nf_conntrack_h323_main.c b/net/netfilter/nf_conntrack_h323_main.c index 1b30b0dee7081..962795e839ab0 100644 --- a/net/netfilter/nf_conntrack_h323_main.c +++ b/net/netfilter/nf_conntrack_h323_main.c @@ -753,7 +753,8 @@ static int callforward_do_filter(const union nf_inet_addr *src, flowi4_to_flowi(&fl1), false)) { if (!afinfo->route(&init_net, (struct dst_entry **)&rt2, flowi4_to_flowi(&fl2), false)) { - if (rt1->rt_gateway == rt2->rt_gateway && + if (rt_nexthop(rt1, fl1.daddr) == + rt_nexthop(rt2, fl2.daddr) && rt1->dst.dev == rt2->dst.dev) ret = 1; dst_release(&rt2->dst); -- 2.39.5