In ip_output(), the flow-table module must not try to cache L2/L3

information for interface of IFF_POINTOPOINT or IFF_LOOPBACK type.
Since the L2 information (rt_lle) is invalid for these interface
types, accidental caching attempt will trigger panic when the invalid
rt_lle reference is accessed.

When installing a new route, or when updating an existing route, the
user supplied gateway address may be an interface address (this is
particularly true for point-to-point interface related modules such
as ppp, if_tun, if_gif). Currently the routing command handler always
set the RTF_GATEWAY flag if the gateway address is given as part of the
command paramters. Therefore the gateway address must be verified against
interface addresses or else the route would be treated as an indirect
route, thus making that route unusable.

Reviewed by:	kmacy, julia, rwatson
Verified by:	marcus
MFC after:	3 days

1 files changed, 34 insertions, 1 deletions

diff --git a/sys/net/rtsock.c b/sys/net/rtsock.c
index 8fb8899..e48ab90 100644
--- a/sys/net/rtsock.c
+++ b/sys/net/rtsock.c
@@ -513,6 +513,39 @@ route_output(struct mbuf *m, struct socket *so)
 			senderr(error);
 	}
 
+	/*
+	 * The given gateway address may be an interface address.
+	 * For example, issuing a "route change" command on a route
+	 * entry that was created from a tunnel, and the gateway
+	 * address given is the local end point. In this case the 
+	 * RTF_GATEWAY flag must be cleared or the destination will
+	 * not be reachable even though there is no error message.
+	 */
+	if (info.rti_info[RTAX_GATEWAY] != NULL &&
+	    info.rti_info[RTAX_GATEWAY]->sa_family != AF_LINK) {
+		struct route gw_ro;
+
+		bzero(&gw_ro, sizeof(gw_ro));
+		gw_ro.ro_dst = *info.rti_info[RTAX_GATEWAY];
+		rtalloc_ign(&gw_ro, 0);
+		/* 
+		 * A host route through the loopback interface is 
+		 * installed for each interface adddress. In pre 8.0
+		 * releases the interface address of a PPP link type
+		 * is not reachable locally. This behavior is fixed as 
+		 * part of the new L2/L3 redesign and rewrite work. The
+		 * signature of this interface address route is the
+		 * AF_LINK sa_family type of the rt_gateway, and the
+		 * rt_ifp has the IFF_LOOPBACK flag set.
+		 */
+		if (gw_ro.ro_rt != NULL &&
+		    gw_ro.ro_rt->rt_gateway->sa_family == AF_LINK &&
+		    gw_ro.ro_rt->rt_ifp->if_flags & IFF_LOOPBACK)
+			info.rti_flags &= ~RTF_GATEWAY;
+		if (gw_ro.ro_rt != NULL)
+			RTFREE(gw_ro.ro_rt);
+	}
+
 	switch (rtm->rtm_type) {
 		struct rtentry *saved_nrt;
 
@@ -714,7 +747,7 @@ route_output(struct mbuf *m, struct socket *so)
 					RT_UNLOCK(rt);
 					senderr(error);
 				}
-				rt->rt_flags |= RTF_GATEWAY;
+				rt->rt_flags |= (RTF_GATEWAY & info.rti_flags);
 			}
 			if (info.rti_ifa != NULL &&
 			    info.rti_ifa != rt->rt_ifa) {