carp backup host replies to arp-request

[Gleb Smirnoff]

  Kazuaki-san,

On Thu, Nov 17, 2005 at 03:22:39PM +0900, Kazuaki Oda wrote:
K> I have set up 2 routers with FreeBSD 6.0-RELEASE.  They are using carp
K> interfaces, so one is a master router and another is a backup.
K> They seemed to work fine, but a few days later I noticed that not only
K> master router but also backup router replies to arp-requests of the
K> common IP address from a layer 3 switch.  This behavior confuses the
K> switch, and sometimes it makes the switch to send a packet addressed
K> to the common IP address to the port which is connected to backup router.
K> I googled and found that OpenBSD fixed this problem in ip_carp.c 1.62.
K> I hope that someone import this into FreeBSD...

Can you please confirm, that the attached patch fixes the problem for you?

-- 
Totus tuus, Glebius.
GLEBIUS-RIPN GLEB-RIPE
-------------- next part --------------
Index: ip_carp.c
===================================================================
RCS file: /home/ncvs/src/sys/netinet/ip_carp.c,v
retrieving revision 1.37
diff -u -r1.37 ip_carp.c
--- ip_carp.c	14 Nov 2005 12:50:23 -0000	1.37
+++ ip_carp.c	17 Nov 2005 09:06:17 -0000
@@ -1162,7 +1162,8 @@
 		TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list) {
 			if ((SC2IFP(vh)->if_flags & IFF_UP) &&
 			    (SC2IFP(vh)->if_drv_flags & IFF_DRV_RUNNING) &&
-			    ia->ia_ifp == SC2IFP(vh)) {
+			    ia->ia_ifp == SC2IFP(vh) &&
+			    vh->sc_state == MASTER) {
 				*enaddr = IF_LLADDR(vh->sc_ifp);
 				CARP_UNLOCK(cif);
 				return (1);
@@ -1187,7 +1188,8 @@
 			if (IN6_ARE_ADDR_EQUAL(taddr,
 			    &ifatoia6(ifa)->ia_addr.sin6_addr) &&
  			    (SC2IFP(vh)->if_flags & IFF_UP) &&
-			    (SC2IFP(vh)->if_drv_flags & IFF_DRV_RUNNING)) {
+			    (SC2IFP(vh)->if_drv_flags & IFF_DRV_RUNNING) &&
+			    vh->sc_state == MASTER) {
 			    	CARP_UNLOCK(cif);
 				return (ifa);
 			}