svn commit: r227460 - head/sys/netinet6

[Qing Li]

Author: qingli
Date: Fri Nov 11 23:22:38 2011
New Revision: 227460
URL: http://svn.freebsd.org/changeset/base/227460

Log:
  A default route learned from the RAs could be deleted manually
  after its installation. This removal may be accidental and can
  prevent the default route from being installed in the future if
  the associated default router has the best preference. The cause
  is the lack of status update in the default router on the state
  of its route installation in the kernel FIB. This patch fixes
  the described problem.
  
  Reviewed by:	hrs, discussed with hrs
  MFC after:	5 days

Modified:
  head/sys/netinet6/in6.c
  head/sys/netinet6/nd6.c
  head/sys/netinet6/nd6.h
  head/sys/netinet6/nd6_rtr.c

Modified: head/sys/netinet6/in6.c
==============================================================================
--- head/sys/netinet6/in6.c	Fri Nov 11 22:57:52 2011	(r227459)
+++ head/sys/netinet6/in6.c	Fri Nov 11 23:22:38 2011	(r227460)
@@ -152,7 +152,7 @@ in6_ifaddloop(struct ifaddr *ifa)
 	ia = ifa2ia6(ifa);
 	ifp = ifa->ifa_ifp;
 	IF_AFDATA_LOCK(ifp);
-	ifa->ifa_rtrequest = NULL;
+	ifa->ifa_rtrequest = nd6_rtrequest;
 
 	/* XXX QL
 	 * we need to report rt_newaddrmsg

Modified: head/sys/netinet6/nd6.c
==============================================================================
--- head/sys/netinet6/nd6.c	Fri Nov 11 22:57:52 2011	(r227459)
+++ head/sys/netinet6/nd6.c	Fri Nov 11 23:22:38 2011	(r227460)
@@ -1174,6 +1174,46 @@ done:
 }
 
 
+/*
+ * Rejuvenate this function for routing operations related
+ * processing.
+ */
+void
+nd6_rtrequest(int req, struct rtentry *rt, struct rt_addrinfo *info)
+{
+	struct sockaddr_in6 *gateway = (struct sockaddr_in6 *)rt->rt_gateway;
+	struct nd_defrouter *dr;
+	struct ifnet *ifp = rt->rt_ifp;
+
+	RT_LOCK_ASSERT(rt);
+
+	switch (req) {
+	case RTM_ADD:
+		break;
+
+	case RTM_DELETE:
+		if (!ifp)
+			return;
+		/*
+		 * Only indirect routes are interesting.
+		 */
+		if ((rt->rt_flags & RTF_GATEWAY) == 0)
+			return;
+		/*
+		 * check for default route
+		 */
+		if (IN6_ARE_ADDR_EQUAL(&in6addr_any, 
+				       &SIN6(rt_key(rt))->sin6_addr)) {
+
+			dr = defrouter_lookup(&gateway->sin6_addr, ifp);
+			if (dr != NULL)
+				dr->installed = 0;
+		}
+		break;
+	}
+}
+
+
 int
 nd6_ioctl(u_long cmd, caddr_t data, struct ifnet *ifp)
 {

Modified: head/sys/netinet6/nd6.h
==============================================================================
--- head/sys/netinet6/nd6.h	Fri Nov 11 22:57:52 2011	(r227459)
+++ head/sys/netinet6/nd6.h	Fri Nov 11 23:22:38 2011	(r227460)
@@ -406,6 +406,7 @@ void nd6_purge __P((struct ifnet *));
 void nd6_nud_hint __P((struct rtentry *, struct in6_addr *, int));
 int nd6_resolve __P((struct ifnet *, struct rtentry *, struct mbuf *,
 	struct sockaddr *, u_char *));
+void nd6_rtrequest __P((int, struct rtentry *, struct rt_addrinfo *));
 int nd6_ioctl __P((u_long, caddr_t, struct ifnet *));
 struct llentry *nd6_cache_lladdr __P((struct ifnet *, struct in6_addr *,
 	char *, int, int, int));

Modified: head/sys/netinet6/nd6_rtr.c
==============================================================================
--- head/sys/netinet6/nd6_rtr.c	Fri Nov 11 22:57:52 2011	(r227459)
+++ head/sys/netinet6/nd6_rtr.c	Fri Nov 11 23:22:38 2011	(r227460)
@@ -751,9 +751,10 @@ defrtrlist_update(struct nd_defrouter *n
 
 			/*
 			 * If the preference does not change, there's no need
-			 * to sort the entries.
+			 * to sort the entries. Also make sure the selected
+			 * router is still installed in the kernel.
 			 */
-			if (rtpref(new) == oldpref) {
+			if (dr->installed && rtpref(new) == oldpref) {
 				splx(s);
 				return (dr);
 			}