Get the default loopback interface pointer just after doing a route

lookup to ensure pf_test() is called with the same interface in the
input annd output path for local traffic.

Fix a regression reported by Heiko Zimmermann on bugs@, thanks!

ok mikeb@, claudio@

2 files changed, 10 insertions, 4 deletions

diff --git a/sys/netinet/ip_output.c b/sys/netinet/ip_output.c
index 805c3776eb6..5ca69d5a69e 100644
--- a/sys/netinet/ip_output.c
+++ b/sys/netinet/ip_output.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ip_output.c,v 1.296 2015/09/12 20:26:07 mpi Exp $	*/
+/*	$OpenBSD: ip_output.c,v 1.297 2015/09/13 13:57:07 mpi Exp $	*/
 /*	$NetBSD: ip_output.c,v 1.28 1996/02/13 23:43:07 christos Exp $	*/
 
 /*
@@ -201,7 +201,10 @@ reroute:
 		}
 
 		ia = ifatoia(ro->ro_rt->rt_ifa);
-		ifp = if_ref(ro->ro_rt->rt_ifp);
+		if (ISSET(ro->ro_rt->rt_flags, RTF_LOCAL))
+			ifp = if_ref(lo0ifp);
+		else
+			ifp = if_ref(ro->ro_rt->rt_ifp);
 		if ((mtu = ro->ro_rt->rt_rmx.rmx_mtu) == 0)
 			mtu = ifp->if_mtu;
 		ro->ro_rt->rt_use++;
diff --git a/sys/netinet6/ip6_output.c b/sys/netinet6/ip6_output.c
index 076cd409dbd..d4d8348d77b 100644
--- a/sys/netinet6/ip6_output.c
+++ b/sys/netinet6/ip6_output.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ip6_output.c,v 1.187 2015/09/12 20:26:07 mpi Exp $	*/
+/*	$OpenBSD: ip6_output.c,v 1.188 2015/09/13 13:57:07 mpi Exp $	*/
 /*	$KAME: ip6_output.c,v 1.172 2001/03/25 09:55:56 itojun Exp $	*/
 
 /*
@@ -550,7 +550,10 @@ reroute:
 			error = EHOSTUNREACH;
 			goto bad;
 		}
-		ifp = if_ref(rt->rt_ifp);
+		if (ISSET(rt->rt_flags, RTF_LOCAL))
+			ifp = if_ref(lo0ifp);
+		else
+			ifp = if_ref(rt->rt_ifp);
 	} else {
 		*dst = dstsock;
 	}