5 files changed, 33 insertions, 10 deletions

diff --git a/sys/netinet6/in6.c b/sys/netinet6/in6.c
index 8514f73..ef22f03 100644
--- a/sys/netinet6/in6.c
+++ b/sys/netinet6/in6.c
@@ -95,6 +95,7 @@ __FBSDID("$FreeBSD$");
 #include <netinet/in_systm.h>
 #include <netinet/ip.h>
 #include <netinet/in_pcb.h>
+#include <netinet/ip_carp.h>
 
 #include <netinet/ip6.h>
 #include <netinet6/ip6_var.h>
@@ -272,6 +273,7 @@ in6_control(struct socket *so, u_long cmd, caddr_t data,
 	struct	in6_ifaddr *ia = NULL;
 	struct	in6_aliasreq *ifra = (struct in6_aliasreq *)data;
 	struct sockaddr_in6 *sa6;
+	int carp_attached = 0;
 	int error;
 
 	switch (cmd) {
@@ -652,6 +654,18 @@ in6_control(struct socket *so, u_long cmd, caddr_t data,
 			break;
 		}
 
+		if (ifra->ifra_vhid > 0) {
+			if (carp_attach_p != NULL)
+				error = (*carp_attach_p)(&ia->ia_ifa,
+				    ifra->ifra_vhid);
+			else
+				error = EPROTONOSUPPORT;
+			if (error)
+				goto out;
+			else
+				carp_attached = 1;
+		}
+
 		/*
 		 * then, make the prefix on-link on the interface.
 		 * XXX: we'd rather create the prefix before the address, but
@@ -695,9 +709,14 @@ in6_control(struct socket *so, u_long cmd, caddr_t data,
 			 * nd6_prelist_add will install the corresponding
 			 * interface route.
 			 */
-			if ((error = nd6_prelist_add(&pr0, NULL, &pr)) != 0)
+			if ((error = nd6_prelist_add(&pr0, NULL, &pr)) != 0) {
+				if (carp_attached)
+					(*carp_detach_p)(&ia->ia_ifa);
 				goto out;
+			}
 			if (pr == NULL) {
+				if (carp_attached)
+					(*carp_detach_p)(&ia->ia_ifa);
 				log(LOG_ERR, "nd6_prelist_add succeeded but "
 				    "no prefix\n");
 				error = EINVAL;
@@ -1301,6 +1320,9 @@ in6_purgeaddr(struct ifaddr *ifa)
 	struct rtentry *rt;
 	struct ifaddr *ifa0, *nifa;
 
+	if (ifa->ifa_carp)
+		(*carp_detach_p)(ifa);
+
 	/*
 	 * find another IPv6 address as the gateway for the
 	 * link-local and node-local all-nodes multicast
diff --git a/sys/netinet6/in6_ifattach.c b/sys/netinet6/in6_ifattach.c
index 2ff7455..1dae2c0 100644
--- a/sys/netinet6/in6_ifattach.c
+++ b/sys/netinet6/in6_ifattach.c
@@ -705,7 +705,6 @@ in6_ifattach(struct ifnet *ifp, struct ifnet *altifp)
 	switch (ifp->if_type) {
 	case IFT_PFLOG:
 	case IFT_PFSYNC:
-	case IFT_CARP:
 		return;
 	}
 
diff --git a/sys/netinet6/in6_var.h b/sys/netinet6/in6_var.h
index 00342fd..3e93e71 100644
--- a/sys/netinet6/in6_var.h
+++ b/sys/netinet6/in6_var.h
@@ -287,6 +287,7 @@ struct	in6_aliasreq {
 	struct	sockaddr_in6 ifra_prefixmask;
 	int	ifra_flags;
 	struct in6_addrlifetime ifra_lifetime;
+	int	ifra_vhid;
 };
 
 /* prefix type macro */
diff --git a/sys/netinet6/nd6.c b/sys/netinet6/nd6.c
index 875daa0..5d6f8c0 100644
--- a/sys/netinet6/nd6.c
+++ b/sys/netinet6/nd6.c
@@ -2173,9 +2173,6 @@ nd6_need_cache(struct ifnet *ifp)
 #ifdef IFT_IEEE80211
 	case IFT_IEEE80211:
 #endif
-#ifdef IFT_CARP
-	case IFT_CARP:
-#endif
 	case IFT_INFINIBAND:
 	case IFT_GIF:		/* XXX need more cases? */
 	case IFT_PPP:
diff --git a/sys/netinet6/nd6_nbr.c b/sys/netinet6/nd6_nbr.c
index 0221c72..a2aaeea 100644
--- a/sys/netinet6/nd6_nbr.c
+++ b/sys/netinet6/nd6_nbr.c
@@ -225,7 +225,7 @@ nd6_ns_input(struct mbuf *m, int off, int icmp6len)
 	/* (1) and (3) check. */
 	if (ifp->if_carp)
 		ifa = (*carp_iamatch6_p)(ifp, &taddr6);
-	if (ifa == NULL)
+	else
 		ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6);
 
 	/* (2) check. */
@@ -688,7 +688,14 @@ nd6_na_input(struct mbuf *m, int off, int icmp6len)
 		lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
 	}
 
-	ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6);
+	/*
+	 * This effectively disables the DAD check on a non-master CARP
+	 * address.
+	 */
+	if (ifp->if_carp)
+		ifa = (*carp_iamatch6_p)(ifp, &taddr6);
+	else
+		ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6);
 
 	/*
 	 * Target address matches one of my interface address.
@@ -1133,9 +1140,6 @@ nd6_ifptomac(struct ifnet *ifp)
 #ifdef IFT_IEEE80211
 	case IFT_IEEE80211:
 #endif
-#ifdef IFT_CARP
-	case IFT_CARP:
-#endif
 	case IFT_INFINIBAND:
 	case IFT_BRIDGE:
 	case IFT_ISO88025: