1 files changed, 88 insertions, 13 deletions

diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c
index a373a25..02c3ba6 100644
--- a/net/ipv4/fib_frontend.c
+++ b/net/ipv4/fib_frontend.c
@@ -722,12 +722,17 @@ void fib_add_ifaddr(struct in_ifaddr *ifa)
 	}
 }
 
-static void fib_del_ifaddr(struct in_ifaddr *ifa)
+/* Delete primary or secondary address.
+ * Optionally, on secondary address promotion consider the addresses
+ * from subnet iprim as deleted, even if they are in device list.
+ * In this case the secondary ifa can be in device list.
+ */
+void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim)
 {
 	struct in_device *in_dev = ifa->ifa_dev;
 	struct net_device *dev = in_dev->dev;
 	struct in_ifaddr *ifa1;
-	struct in_ifaddr *prim = ifa;
+	struct in_ifaddr *prim = ifa, *prim1 = NULL;
 	__be32 brd = ifa->ifa_address | ~ifa->ifa_mask;
 	__be32 any = ifa->ifa_address & ifa->ifa_mask;
 #define LOCAL_OK	1
@@ -735,17 +740,26 @@ static void fib_del_ifaddr(struct in_ifaddr *ifa)
 #define BRD0_OK		4
 #define BRD1_OK		8
 	unsigned ok = 0;
+	int subnet = 0;		/* Primary network */
+	int gone = 1;		/* Address is missing */
+	int same_prefsrc = 0;	/* Another primary with same IP */
 
-	if (!(ifa->ifa_flags & IFA_F_SECONDARY))
-		fib_magic(RTM_DELROUTE,
-			  dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
-			  any, ifa->ifa_prefixlen, prim);
-	else {
+	if (ifa->ifa_flags & IFA_F_SECONDARY) {
 		prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask);
 		if (prim == NULL) {
 			printk(KERN_WARNING "fib_del_ifaddr: bug: prim == NULL\n");
 			return;
 		}
+		if (iprim && iprim != prim) {
+			printk(KERN_WARNING "fib_del_ifaddr: bug: iprim != prim\n");
+			return;
+		}
+	} else if (!ipv4_is_zeronet(any) &&
+		   (any != ifa->ifa_local || ifa->ifa_prefixlen < 32)) {
+		fib_magic(RTM_DELROUTE,
+			  dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
+			  any, ifa->ifa_prefixlen, prim);
+		subnet = 1;
 	}
 
 	/* Deletion is more complicated than add.
@@ -755,6 +769,49 @@ static void fib_del_ifaddr(struct in_ifaddr *ifa)
 	 */
 
 	for (ifa1 = in_dev->ifa_list; ifa1; ifa1 = ifa1->ifa_next) {
+		if (ifa1 == ifa) {
+			/* promotion, keep the IP */
+			gone = 0;
+			continue;
+		}
+		/* Ignore IFAs from our subnet */
+		if (iprim && ifa1->ifa_mask == iprim->ifa_mask &&
+		    inet_ifa_match(ifa1->ifa_address, iprim))
+			continue;
+
+		/* Ignore ifa1 if it uses different primary IP (prefsrc) */
+		if (ifa1->ifa_flags & IFA_F_SECONDARY) {
+			/* Another address from our subnet? */
+			if (ifa1->ifa_mask == prim->ifa_mask &&
+			    inet_ifa_match(ifa1->ifa_address, prim))
+				prim1 = prim;
+			else {
+				/* We reached the secondaries, so
+				 * same_prefsrc should be determined.
+				 */
+				if (!same_prefsrc)
+					continue;
+				/* Search new prim1 if ifa1 is not
+				 * using the current prim1
+				 */
+				if (!prim1 ||
+				    ifa1->ifa_mask != prim1->ifa_mask ||
+				    !inet_ifa_match(ifa1->ifa_address, prim1))
+					prim1 = inet_ifa_byprefix(in_dev,
+							ifa1->ifa_address,
+							ifa1->ifa_mask);
+				if (!prim1)
+					continue;
+				if (prim1->ifa_local != prim->ifa_local)
+					continue;
+			}
+		} else {
+			if (prim->ifa_local != ifa1->ifa_local)
+				continue;
+			prim1 = ifa1;
+			if (prim != prim1)
+				same_prefsrc = 1;
+		}
 		if (ifa->ifa_local == ifa1->ifa_local)
 			ok |= LOCAL_OK;
 		if (ifa->ifa_broadcast == ifa1->ifa_broadcast)
@@ -763,19 +820,37 @@ static void fib_del_ifaddr(struct in_ifaddr *ifa)
 			ok |= BRD1_OK;
 		if (any == ifa1->ifa_broadcast)
 			ok |= BRD0_OK;
+		/* primary has network specific broadcasts */
+		if (prim1 == ifa1 && ifa1->ifa_prefixlen < 31) {
+			__be32 brd1 = ifa1->ifa_address | ~ifa1->ifa_mask;
+			__be32 any1 = ifa1->ifa_address & ifa1->ifa_mask;
+
+			if (!ipv4_is_zeronet(any1)) {
+				if (ifa->ifa_broadcast == brd1 ||
+				    ifa->ifa_broadcast == any1)
+					ok |= BRD_OK;
+				if (brd == brd1 || brd == any1)
+					ok |= BRD1_OK;
+				if (any == brd1 || any == any1)
+					ok |= BRD0_OK;
+			}
+		}
 	}
 
 	if (!(ok & BRD_OK))
 		fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim);
-	if (!(ok & BRD1_OK))
-		fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32, prim);
-	if (!(ok & BRD0_OK))
-		fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32, prim);
+	if (subnet && ifa->ifa_prefixlen < 31) {
+		if (!(ok & BRD1_OK))
+			fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32, prim);
+		if (!(ok & BRD0_OK))
+			fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32, prim);
+	}
 	if (!(ok & LOCAL_OK)) {
 		fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim);
 
 		/* Check, that this local address finally disappeared. */
-		if (inet_addr_type(dev_net(dev), ifa->ifa_local) != RTN_LOCAL) {
+		if (gone &&
+		    inet_addr_type(dev_net(dev), ifa->ifa_local) != RTN_LOCAL) {
 			/* And the last, but not the least thing.
 			 * We must flush stray FIB entries.
 			 *
@@ -896,7 +971,7 @@ static int fib_inetaddr_event(struct notifier_block *this, unsigned long event,
 		rt_cache_flush(dev_net(dev), -1);
 		break;
 	case NETDEV_DOWN:
-		fib_del_ifaddr(ifa);
+		fib_del_ifaddr(ifa, NULL);
 		fib_update_nh_saddrs(dev);
 		if (ifa->ifa_dev->ifa_list == NULL) {
 			/* Last address was deleted from this interface.