svn commit: r226713 - head/sys/netinet

[Qing Li]

Author: qingli
Date: Tue Oct 25 04:06:29 2011
New Revision: 226713
URL: http://svn.freebsd.org/changeset/base/226713

Log:
  Exclude host routes when checking for prefix coverage on multiple
  interfaces. A host route has a NULL mask so check for that condition.
  I have also been told by developers who customize the packet output
  path with direct manipulation of the route entry (or the outgoing
  interface to be specific). This patch checks for the route mask
  explicitly to make sure custom code will not panic.
  
  PR:		kern/161805
  MFC after:	3 days

Modified:
  head/sys/netinet/in.c

Modified: head/sys/netinet/in.c
==============================================================================
--- head/sys/netinet/in.c	Tue Oct 25 01:47:33 2011	(r226712)
+++ head/sys/netinet/in.c	Tue Oct 25 04:06:29 2011	(r226713)
@@ -1429,12 +1429,21 @@ in_lltable_rtcheck(struct ifnet *ifp, u_
 	 * on one interface and the corresponding outgoing packet leaves
 	 * another interface.
 	 */
-	if (rt->rt_ifp != ifp) {
+	if (!(rt->rt_flags & RTF_HOST) && rt->rt_ifp != ifp) {
 		const char *sa, *mask, *addr, *lim;
 		int len;
 
-		sa = (const char *)rt_key(rt);
 		mask = (const char *)rt_mask(rt);
+		/*
+		 * Just being extra cautious to avoid some custom
+		 * code getting into trouble.
+		 */
+		if (mask == NULL) {
+			RTFREE_LOCKED(rt);
+			return (EINVAL);
+		}
+
+		sa = (const char *)rt_key(rt);
 		addr = (const char *)l3addr;
 		len = ((const struct sockaddr_in *)l3addr)->sin_len;
 		lim = addr + len;