svn commit: r225947 - head/sys/netinet

[Qing Li]

Author: qingli
Date: Mon Oct  3 19:51:18 2011
New Revision: 225947
URL: http://svn.freebsd.org/changeset/base/225947

Log:
  A system may have multiple physical interfaces, all of which are on the
  same prefix. Since a single route entry is installed for the prefix
  (without RADIX_MPATH), incoming packets on the interfaces that are not
  associated with the prefix route may trigger an error message about
  unable to allocation LLE entry, and fails L2. This patch makes sure a
  valid route is present in the system, and allow the aforementioned
  condition to exist and treats as valid.
  
  Reviewed by:	bz
  MFC after:	5 days

Modified:
  head/sys/netinet/in.c

Modified: head/sys/netinet/in.c
==============================================================================
--- head/sys/netinet/in.c	Mon Oct  3 19:06:55 2011	(r225946)
+++ head/sys/netinet/in.c	Mon Oct  3 19:51:18 2011	(r225947)
@@ -1439,14 +1439,43 @@ in_lltable_rtcheck(struct ifnet *ifp, u_
 		if (memcmp(rt->rt_gateway->sa_data, l3addr->sa_data,
 		    sizeof(in_addr_t)) != 0)
 			error = EINVAL;
-	} else if (!(flags & LLE_PUB) && ((rt->rt_flags & RTF_GATEWAY) ||
-	    (rt->rt_ifp != ifp))) {
+	}
+
+	if (rt->rt_flags & RTF_GATEWAY) {
+		RTFREE_LOCKED(rt);
+		return (EINVAL);
+	}
+
+	/*
+	 * Make sure that at least the destination address is covered 
+	 * by the route. This is for handling the case where 2 or more 
+	 * interfaces have the same prefix. An incoming packet arrives
+	 * on one interface and the corresponding outgoing packet leaves
+	 * another interface.
+	 * 
+	 */
+	if (rt->rt_ifp != ifp) {
+		char *sa, *mask, *addr, *lim;
+		int len;
+
+		sa = (char *)rt_key(rt);
+		mask = (char *)rt_mask(rt);
+		addr = (char *)__DECONST(struct sockaddr *, l3addr);
+		len = ((struct sockaddr_in *)__DECONST(struct sockaddr *, l3addr))->sin_len;
+		lim = addr + len;
+
+		for ( ; addr < lim; sa++, mask++, addr++) {
+			if ((*sa ^ *addr) & *mask) {
+				error = EINVAL;
 #ifdef DIAGNOSTIC
-		log(LOG_INFO, "IPv4 address: \"%s\" is not on the network\n",
-		    inet_ntoa(((const struct sockaddr_in *)l3addr)->sin_addr));
+				log(LOG_INFO, "IPv4 address: \"%s\" is not on the network\n",
+				    inet_ntoa(((const struct sockaddr_in *)l3addr)->sin_addr));
 #endif
-		error = EINVAL;
+				break;
+			}
+		}
 	}
+
 	RTFREE_LOCKED(rt);
 	return (error);
 }