From 0897bcc8ad66822fea3078e643be9222ad2cd73d Mon Sep 17 00:00:00 2001
From: qingli <qingli@FreeBSD.org>
Date: Wed, 30 Dec 2009 22:13:01 +0000
Subject: [PATCH] Consolidate the route message generation code for when
 address aliases were added or deleted. The announced route entry for an
 address alias is no longer empty because this empty route entry was causing
 some route daemon to fail and exit abnormally.

MFC after:	5 days
---
 sys/netinet/in.c | 97 ++++++++++++++++++++++++------------------------
 1 file changed, 49 insertions(+), 48 deletions(-)

diff --git a/sys/netinet/in.c b/sys/netinet/in.c
index c5317e5529ff..a0d6ac9e2131 100644
--- a/sys/netinet/in.c
+++ b/sys/netinet/in.c
@@ -950,6 +950,49 @@ in_ifinit(struct ifnet *ifp, struct in_ifaddr *ia, struct sockaddr_in *sin,
 #define rtinitflags(x) \
 	((((x)->ia_ifp->if_flags & (IFF_LOOPBACK | IFF_POINTOPOINT)) != 0) \
 	    ? RTF_HOST : 0)
+
+/*
+ * Generate a routing message when inserting or deleting 
+ * an interface address alias.
+ */
+static void in_addralias_rtmsg(int cmd, struct in_addr *prefix, 
+    struct in_ifaddr *target)
+{
+	struct route pfx_ro;
+	struct sockaddr_in *pfx_addr;
+	struct rtentry msg_rt;
+
+	/* QL: XXX
+	 * This is a bit questionable because there is no
+	 * additional route entry added/deleted for an address
+	 * alias. Therefore this route report is inaccurate.
+	 */
+	bzero(&pfx_ro, sizeof(pfx_ro));
+	pfx_addr = (struct sockaddr_in *)(&pfx_ro.ro_dst);
+	pfx_addr->sin_len = sizeof(*pfx_addr);
+	pfx_addr->sin_family = AF_INET;
+	pfx_addr->sin_addr = *prefix;
+	rtalloc_ign_fib(&pfx_ro, 0, 0);
+	if (pfx_ro.ro_rt != NULL) {
+		msg_rt = *pfx_ro.ro_rt;
+
+		/* QL: XXX
+		 * Point the gateway to the new interface
+		 * address as if a new prefix route entry has 
+		 * been added through the new address alias. 
+		 * All other parts of the rtentry is accurate, 
+		 * e.g., rt_key, rt_mask, rt_ifp etc.
+		 */
+		msg_rt.rt_gateway = 
+			(struct sockaddr *)&target->ia_addr;
+		rt_newaddrmsg(cmd, 
+			      (struct ifaddr *)target,
+			      0, &msg_rt);
+		RTFREE(pfx_ro.ro_rt);
+	}
+	return;
+}
+
 /*
  * Check if we have a route for the given prefix already or add one accordingly.
  */
@@ -997,40 +1040,7 @@ in_addprefix(struct in_ifaddr *target, int flags)
 				IN_IFADDR_RUNLOCK();
 				return (EEXIST);
 			} else {
-				struct route pfx_ro;
-				struct sockaddr_in *pfx_addr;
-				struct rtentry msg_rt;
-
-				/* QL: XXX
-				 * This is a bit questionable because there is no
-				 * additional route entry added for an address alias.
-				 * Therefore this route report is inaccurate. Perhaps
-				 * it's better to supply a empty rtentry as how it
-				 * is done in in_scrubprefix().
-				 */
-				bzero(&pfx_ro, sizeof(pfx_ro));
-				pfx_addr = (struct sockaddr_in *)(&pfx_ro.ro_dst);
-				pfx_addr->sin_len = sizeof(*pfx_addr);
-				pfx_addr->sin_family = AF_INET;
-				pfx_addr->sin_addr = prefix;
-				rtalloc_ign_fib(&pfx_ro, 0, 0);
-				if (pfx_ro.ro_rt != NULL) {
-					msg_rt = *pfx_ro.ro_rt;
-					/* QL: XXX
-					 * Point the gateway to the given interface
-					 * address as if a new prefix route entry has 
-					 * been added through the new address alias. 
-					 * All other parts of the rtentry is accurate, 
-					 * e.g., rt_key, rt_mask, rt_ifp etc.
-					 */
-					msg_rt.rt_gateway = 
-						(struct sockaddr *)&ia->ia_addr;
-					rt_newaddrmsg(RTM_ADD, 
-						      (struct ifaddr *)target,
-						      0, &msg_rt);
-					RTFREE(pfx_ro.ro_rt);
-				}
-
+				in_addralias_rtmsg(RTM_ADD, &prefix, target);
 				IN_IFADDR_RUNLOCK();
 				return (0);
 			}
@@ -1099,20 +1109,6 @@ in_scrubprefix(struct in_ifaddr *target)
 		arp_ifscrub(target->ia_ifp, IA_SIN(target)->sin_addr.s_addr);
 	}
 
-	if ((target->ia_flags & IFA_ROUTE) == 0) {
-		struct rtentry rt;
-
-		/* QL: XXX
-		 * Report a blank rtentry when a route has not been
-		 * installed for the given interface address.
-		 */
-		bzero(&rt, sizeof(rt));
-		rt_newaddrmsg(RTM_DELETE, 
-			      (struct ifaddr *)target,
-			      0, &rt);
-		return (0);
-	}
-
 	if (rtinitflags(target))
 		prefix = target->ia_dstaddr.sin_addr;
 	else {
@@ -1121,6 +1117,11 @@ in_scrubprefix(struct in_ifaddr *target)
 		prefix.s_addr &= mask.s_addr;
 	}
 
+	if ((target->ia_flags & IFA_ROUTE) == 0) {
+		in_addralias_rtmsg(RTM_DELETE, &prefix, target);
+		return (0);
+	}
+
 	IN_IFADDR_RLOCK();
 	TAILQ_FOREACH(ia, &V_in_ifaddrhead, ia_link) {
 		if (rtinitflags(ia))