Bite the bullet, and make the IPv6 SSM and MLDv2 mega-commit:

import from p4 bms_netdev.  Summary of changes:

 * Connect netinet6/in6_mcast.c to build.
   The legacy KAME KPIs are mostly preserved.
 * Eliminate now dead code from ip6_output.c.
   Don't do mbuf bingo, we are not going to do RFC 2292 style
   CMSG tricks for multicast options as they are not required
   by any current IPv6 normative reference.
 * Refactor transports (UDP, raw_ip6) to do own mcast filtering.
   SCTP, TCP unaffected by this change.
 * Add ip6_msource, in6_msource structs to in6_var.h.
 * Hookup mld_ifinfo state to in6_ifextra, allocate from
   domifattach path.
 * Eliminate IN6_LOOKUP_MULTI(), it is no longer referenced.
   Kernel consumers which need this should use in6m_lookup().
 * Refactor IPv6 socket group memberships to use a vector (like IPv4).
 * Update ifmcstat(8) for IPv6 SSM.
 * Add witness lock order for IN6_MULTI_LOCK.
 * Move IN6_MULTI_LOCK out of lower ip6_output()/ip6_input() paths.
 * Introduce IP6STAT_ADD/SUB/INC/DEC as per rwatson's IPv4 cleanup.
 * Update carp(4) for new IPv6 SSM KPIs.
 * Virtualize ip6_mrouter socket.
   Changes mostly localized to IPv6 MROUTING.
 * Don't do a local group lookup in MROUTING.
 * Kill unused KAME prototypes in6_purgemkludge(), in6_restoremkludge().
 * Preserve KAME DAD timer jitter behaviour in MLDv1 compatibility mode.
 * Bump __FreeBSD_version to 800084.
 * Update UPDATING.

NOTE WELL:
 * This code hasn't been tested against real MLDv2 queriers
   (yet), although the on-wire protocol has been verified in Wireshark.
 * There are a few unresolved issues in the socket layer APIs to
   do with scope ID propagation.
 * There is a LOR present in ip6_output()'s use of
   in6_setscope() which needs to be resolved. See comments in mld6.c.
   This is believed to be benign and can't be avoided for the moment
   without re-introducing an indirect netisr.

This work was mostly derived from the IGMPv3 implementation, and
has been sponsored by a third party.

16 files changed, 3689 insertions, 1085 deletions

diff --git a/sys/netinet6/icmp6.c b/sys/netinet6/icmp6.c
index 866fee1..1c8a132 100644
--- a/sys/netinet6/icmp6.c
+++ b/sys/netinet6/icmp6.c
@@ -147,8 +147,6 @@ icmp6_init(void)
 	INIT_VNET_INET6(curvnet);
 
 	V_icmp6errpps_count = 0;
-
-	mld6_init();
 }
 
 static void
@@ -429,6 +427,23 @@ icmp6_input(struct mbuf **mp, int *offp, int proto)
 	}
 
 	/*
+	 * Check multicast group membership.
+	 * Note: SSM filters are not applied for ICMPv6 traffic.
+	 */
+	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
+		struct ifnet *ifp;
+		struct in6_multi *inm;
+
+		ifp = m->m_pkthdr.rcvif;
+		inm = in6m_lookup(ifp, &ip6->ip6_dst);
+		if (inm == NULL) {
+			IP6STAT_INC(ip6s_notmember);
+			in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
+			goto freeit;
+		}
+	}
+
+	/*
 	 * calculate the checksum
 	 */
 #ifndef PULLDOWN_TEST
@@ -615,34 +630,20 @@ icmp6_input(struct mbuf **mp, int *offp, int proto)
 
 	case MLD_LISTENER_QUERY:
 	case MLD_LISTENER_REPORT:
-		if (icmp6len < sizeof(struct mld_hdr))
-			goto badlen;
-		if (icmp6->icmp6_type == MLD_LISTENER_QUERY) /* XXX: ugly... */
-			icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mldquery);
-		else
-			icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mldreport);
-		if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
-			/* give up local */
-			mld6_input(m, off);
-			m = NULL;
+	case MLD_LISTENER_DONE:
+	case MLDV2_LISTENER_REPORT:
+		/*
+		 * Drop MLD traffic which is not link-local.
+		 * XXX Should we also sanity check that these messages
+		 * were directed to a link-local multicast prefix?
+		 */
+		if (ip6->ip6_hlim != 1)
 			goto freeit;
-		}
-		mld6_input(n, off);
+		if (mld_input(m, off, icmp6len) != 0)
+			return (IPPROTO_DONE);
 		/* m stays. */
 		break;
 
-	case MLD_LISTENER_DONE:
-		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mlddone);
-		if (icmp6len < sizeof(struct mld_hdr))	/* necessary? */
-			goto badlen;
-		break;		/* nothing to be done in kernel */
-
-	case MLD_MTRACE_RESP:
-	case MLD_MTRACE:
-		/* XXX: these two are experimental.  not officially defined. */
-		/* XXX: per-interface statistics? */
-		break;		/* just pass it to applications */
-
 	case ICMP6_WRUREQUEST:	/* ICMP6_FQDN_QUERY */
 	    {
 		enum { WRU, FQDN } mode;
@@ -2050,7 +2051,7 @@ icmp6_rip6_input(struct mbuf **mp, int off)
 		INP_RUNLOCK(last);
 	} else {
 		m_freem(m);
-		V_ip6stat.ip6s_delivered--;
+		IP6STAT_DEC(ip6s_delivered);
 	}
 	return IPPROTO_DONE;
 }
@@ -2222,7 +2223,14 @@ void
 icmp6_fasttimo(void)
 {
 
-	return;
+	mld_fasttimo();
+}
+
+void
+icmp6_slowtimo(void)
+{
+
+	mld_slowtimo();
 }
 
 static const char *
diff --git a/sys/netinet6/in6.c b/sys/netinet6/in6.c
index d0caa7e..df57bf6 100644
--- a/sys/netinet6/in6.c
+++ b/sys/netinet6/in6.c
@@ -106,8 +106,6 @@ __FBSDID("$FreeBSD$");
 #include <netinet6/in6_pcb.h>
 #include <netinet6/vinet6.h>
 
-MALLOC_DEFINE(M_IP6MADDR, "in6_multi", "internet multicast address");
-
 /*
  * Definitions of some costant IP6 addresses.
  */
@@ -119,6 +117,8 @@ const struct in6_addr in6addr_linklocal_allnodes =
 	IN6ADDR_LINKLOCAL_ALLNODES_INIT;
 const struct in6_addr in6addr_linklocal_allrouters =
 	IN6ADDR_LINKLOCAL_ALLROUTERS_INIT;
+const struct in6_addr in6addr_linklocal_allv2routers =
+	IN6ADDR_LINKLOCAL_ALLV2ROUTERS_INIT;
 
 const struct in6_addr in6mask0 = IN6MASK0;
 const struct in6_addr in6mask32 = IN6MASK32;
@@ -135,7 +135,6 @@ static int in6_ifinit __P((struct ifnet *, struct in6_ifaddr *,
 	struct sockaddr_in6 *, int));
 static void in6_unlink_ifa(struct in6_ifaddr *, struct ifnet *);
 
-struct in6_multihead in6_multihead;	/* XXX BSS initialization */
 int	(*faithprefix_p)(struct in6_addr *);
 
 
@@ -1110,10 +1109,12 @@ in6_update_ifa(struct ifnet *ifp, struct in6_aliasreq *ifra,
 			 * should be larger than the MLD delay (this could be
 			 * relaxed a bit, but this simple logic is at least
 			 * safe).
+			 * XXX: Break data hiding guidelines and look at
+			 * state for the solicited multicast group.
 			 */
 			mindelay = 0;
 			if (in6m_sol != NULL &&
-			    in6m_sol->in6m_state == MLD_REPORTPENDING) {
+			    in6m_sol->in6m_state == MLD_REPORTING_MEMBER) {
 				mindelay = in6m_sol->in6m_timer;
 			}
 			maxdelay = MAX_RTR_SOLICITATION_DELAY * hz;
@@ -1590,36 +1591,6 @@ in6_ifinit(struct ifnet *ifp, struct in6_ifaddr *ia,
 	return (error);
 }
 
-struct in6_multi_mship *
-in6_joingroup(struct ifnet *ifp, struct in6_addr *addr,
-    int *errorp, int delay)
-{
-	struct in6_multi_mship *imm;
-
-	imm = malloc(sizeof(*imm), M_IP6MADDR, M_NOWAIT);
-	if (!imm) {
-		*errorp = ENOBUFS;
-		return NULL;
-	}
-	imm->i6mm_maddr = in6_addmulti(addr, ifp, errorp, delay);
-	if (!imm->i6mm_maddr) {
-		/* *errorp is alrady set */
-		free(imm, M_IP6MADDR);
-		return NULL;
-	}
-	return imm;
-}
-
-int
-in6_leavegroup(struct in6_multi_mship *imm)
-{
-
-	if (imm->i6mm_maddr)
-		in6_delmulti(imm->i6mm_maddr);
-	free(imm,  M_IP6MADDR);
-	return 0;
-}
-
 /*
  * Find an IPv6 interface link-local address specific to an interface.
  */
@@ -2328,6 +2299,9 @@ in6_domifattach(struct ifnet *ifp)
 		ext->lltable->llt_lookup = in6_lltable_lookup;
 		ext->lltable->llt_dump = in6_lltable_dump;
 	}
+
+	ext->mld_ifinfo = mld_domifattach(ifp);
+
 	return ext;
 }
 
@@ -2336,6 +2310,7 @@ in6_domifdetach(struct ifnet *ifp, void *aux)
 {
 	struct in6_ifextra *ext = (struct in6_ifextra *)aux;
 
+	mld_domifdetach(ifp);
 	scope6_ifdetach(ext->scope6_id);
 	nd6_ifdetach(ext->nd_ifinfo);
 	lltable_free(ext->lltable);
diff --git a/sys/netinet6/in6_ifattach.c b/sys/netinet6/in6_ifattach.c
index 80b6d6b..077014e 100644
--- a/sys/netinet6/in6_ifattach.c
+++ b/sys/netinet6/in6_ifattach.c
@@ -63,6 +63,7 @@ __FBSDID("$FreeBSD$");
 #include <netinet6/in6_ifattach.h>
 #include <netinet6/ip6_var.h>
 #include <netinet6/nd6.h>
+#include <netinet6/mld6_var.h>
 #include <netinet6/scope6_var.h>
 #include <netinet6/vinet6.h>
 
@@ -918,11 +919,35 @@ in6_tmpaddrtimer(void *ignored_arg)
 static void
 in6_purgemaddrs(struct ifnet *ifp)
 {
-	struct in6_multi *in6m;
-	struct in6_multi *oin6m;
+	INIT_VNET_INET6(ifp->if_vnet);
+	LIST_HEAD(,in6_multi)	 purgeinms;
+	struct in6_multi	*inm, *tinm;
+	struct ifmultiaddr	*ifma;
+
+	LIST_INIT(&purgeinms);
+	IN6_MULTI_LOCK();
+
+	/*
+	 * Extract list of in6_multi associated with the detaching ifp
+	 * which the PF_INET6 layer is about to release.
+	 * We need to do this as IF_ADDR_LOCK() may be re-acquired
+	 * by code further down.
+	 */
+	IF_ADDR_LOCK(ifp);
+	TAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
+		if (ifma->ifma_addr->sa_family != AF_INET6 ||
+		    ifma->ifma_protospec == NULL)
+			continue;
+		inm = (struct in6_multi *)ifma->ifma_protospec;
+		LIST_INSERT_HEAD(&purgeinms, inm, in6m_entry);
+	}
+	IF_ADDR_UNLOCK(ifp);
 
-	LIST_FOREACH_SAFE(in6m, &in6_multihead, in6m_entry, oin6m) {
-		if (in6m->in6m_ifp == ifp)
-			in6_delmulti(in6m);
+	LIST_FOREACH_SAFE(inm, &purgeinms, in6m_entry, tinm) {
+		LIST_REMOVE(inm, in6m_entry);
+		in6m_release_locked(inm);
 	}
+	mld_ifdetach(ifp);
+
+	IN6_MULTI_UNLOCK();
 }
diff --git a/sys/netinet6/in6_mcast.c b/sys/netinet6/in6_mcast.c
index a4d435c..b3f272c 100644
--- a/sys/netinet6/in6_mcast.c
+++ b/sys/netinet6/in6_mcast.c
@@ -29,6 +29,7 @@
 
 /*
  * IPv6 multicast socket, group, and socket option processing module.
+ * Normative references: RFC 2292, RFC 3492, RFC 3542, RFC 3678, RFC 3810.
  */
 
 #include <sys/cdefs.h>
@@ -142,6 +143,9 @@ static struct ip6_moptions *
 static int	in6p_get_source_filters(struct inpcb *, struct sockopt *);
 static int	in6p_join_group(struct inpcb *, struct sockopt *);
 static int	in6p_leave_group(struct inpcb *, struct sockopt *);
+static struct ifnet *
+		in6p_lookup_mcast_ifp(const struct inpcb *,
+		    const struct sockaddr_in6 *);
 static int	in6p_block_unblock_source(struct inpcb *, struct sockopt *);
 static int	in6p_set_multicast_if(struct inpcb *, struct sockopt *);
 static int	in6p_set_source_filters(struct inpcb *, struct sockopt *);
@@ -1655,12 +1659,12 @@ int
 ip6_getmoptions(struct inpcb *inp, struct sockopt *sopt)
 {
 	INIT_VNET_INET6(curvnet);
-	struct ip6_moptions	*imo;
-	int			 error, optval;
-	u_char			 coptval;
+	struct ip6_moptions	*im6o;
+	int			 error;
+	u_int			 optval;
 
 	INP_WLOCK(inp);
-	imo = inp->in6p_moptions;
+	im6o = inp->in6p_moptions;
 	/*
 	 * If socket is neither of type SOCK_RAW or SOCK_DGRAM,
 	 * or is a divert socket, reject it.
@@ -1674,38 +1678,36 @@ ip6_getmoptions(struct inpcb *inp, struct sockopt *sopt)
 
 	error = 0;
 	switch (sopt->sopt_name) {
-#if 0 /* XXX FIXME */
 	case IPV6_MULTICAST_IF:
-		if (imo == NULL || imo->im6o_multicast_ifp == NULL) {
+		if (im6o == NULL || im6o->im6o_multicast_ifp == NULL) {
 			optval = 0;
 		} else {
-			optval = imo->im6o_multicast_ifp->if_index;
+			optval = im6o->im6o_multicast_ifp->if_index;
 		}
 		INP_WUNLOCK(inp);
-		error = sooptcopyout(sopt, &ifindex, sizeof(u_int));
+		error = sooptcopyout(sopt, &optval, sizeof(u_int));
 		break;
-#endif
 
 	case IPV6_MULTICAST_HOPS:
-		if (imo == 0)
-			optval = coptval = V_ip6_defmcasthlim;
+		if (im6o == NULL)
+			optval = V_ip6_defmcasthlim;
 		else
-			optval = coptval = imo->im6o_multicast_loop;
+			optval = im6o->im6o_multicast_loop;
 		INP_WUNLOCK(inp);
 		error = sooptcopyout(sopt, &optval, sizeof(u_int));
 		break;
 
 	case IPV6_MULTICAST_LOOP:
-		if (imo == 0)
-			optval = coptval = IPV6_DEFAULT_MULTICAST_LOOP;
+		if (im6o == NULL)
+			optval = in6_mcast_loop; /* XXX VIMAGE */
 		else
-			optval = coptval = imo->im6o_multicast_loop;
+			optval = im6o->im6o_multicast_loop;
 		INP_WUNLOCK(inp);
 		error = sooptcopyout(sopt, &optval, sizeof(u_int));
 		break;
 
 	case IPV6_MSFILTER:
-		if (imo == NULL) {
+		if (im6o == NULL) {
 			error = EADDRNOTAVAIL;
 			INP_WUNLOCK(inp);
 		} else {
@@ -1725,7 +1727,57 @@ ip6_getmoptions(struct inpcb *inp, struct sockopt *sopt)
 }
 
 /*
+ * Look up the ifnet to use for a multicast group membership,
+ * given the address of an IPv6 group.
+ *
+ * This routine exists to support legacy IPv6 multicast applications.
+ *
+ * If inp is non-NULL, use this socket's current FIB number for any
+ * required FIB lookup. Look up the group address in the unicast FIB,
+ * and use its ifp; usually, this points to the default next-hop.
+ * If the FIB lookup fails, return NULL.
+ *
+ * FUTURE: Support multiple forwarding tables for IPv6.
+ *
+ * Returns NULL if no ifp could be found.
+ */
+static struct ifnet *
+in6p_lookup_mcast_ifp(const struct inpcb *in6p __unused,
+    const struct sockaddr_in6 *gsin6)
+{
+	INIT_VNET_INET6(curvnet);
+	struct route_in6	 ro6;
+	struct ifnet		*ifp;
+
+	KASSERT(in6p->inp_vflag & INP_IPV6,
+	    ("%s: not INP_IPV6 inpcb", __func__));
+	KASSERT(gsin6->sin6_family == AF_INET6,
+	    ("%s: not AF_INET6 group", __func__));
+	KASSERT(IN6_IS_ADDR_MULTICAST(&gsin6->sin6_addr),
+	    ("%s: not multicast", __func__));
+
+	ifp = NULL;
+	memset(&ro6, 0, sizeof(struct route_in6));
+	memcpy(&ro6.ro_dst, gsin6, sizeof(struct sockaddr_in6));
+#ifdef notyet
+	rtalloc_ign_fib(&ro6, 0, inp ? inp->inp_inc.inc_fibnum : 0);
+#else
+	rtalloc_ign((struct route *)&ro6, 0);
+#endif
+	if (ro6.ro_rt != NULL) {
+		ifp = ro6.ro_rt->rt_ifp;
+		KASSERT(ifp != NULL, ("%s: null ifp", __func__));
+		RTFREE(ro6.ro_rt);
+	}
+
+	return (ifp);
+}
+
+/*
  * Join an IPv6 multicast group, possibly with a source.
+ *
+ * FIXME: The KAME use of the unspecified address (::)
+ * to join *all* multicast groups is currently unsupported.
  */
 static int
 in6p_join_group(struct inpcb *inp, struct sockopt *sopt)
@@ -1765,8 +1817,14 @@ in6p_join_group(struct inpcb *inp, struct sockopt *sopt)
 		gsa->sin6.sin6_len = sizeof(struct sockaddr_in6);
 		gsa->sin6.sin6_addr = mreq.ipv6mr_multiaddr;
 
-		ifp = ifnet_byindex(mreq.ipv6mr_interface);
-
+		if (mreq.ipv6mr_interface == 0) {
+			ifp = in6p_lookup_mcast_ifp(inp, &gsa->sin6);
+		} else {
+			if (mreq.ipv6mr_interface < 0 ||
+			    V_if_index < mreq.ipv6mr_interface)
+				return (EADDRNOTAVAIL);
+			ifp = ifnet_byindex(mreq.ipv6mr_interface);
+		}
 		CTR3(KTR_MLD, "%s: ipv6mr_interface = %d, ifp = %p",
 		    __func__, mreq.ipv6mr_interface, ifp);
 	} break;
@@ -1813,12 +1871,35 @@ in6p_join_group(struct inpcb *inp, struct sockopt *sopt)
 		break;
 	}
 
+#ifdef notyet
+	/*
+	 * FIXME: Check for unspecified address (all groups).
+	 * Do we have a normative reference for this 'feature'?
+	 *
+	 * We use the unspecified address to specify to accept
+	 * all multicast addresses. Only super user is allowed
+	 * to do this.
+	 * XXX-BZ might need a better PRIV_NETINET_x for this
+	 */
+	if (IN6_IS_ADDR_UNSPECIFIED(&gsa->sin6.sin6_addr)) {
+		error = priv_check(curthread, PRIV_NETINET_MROUTE);
+		if (error)
+		break;
+	} else
+#endif
 	if (!IN6_IS_ADDR_MULTICAST(&gsa->sin6.sin6_addr))
 		return (EINVAL);
 
 	if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0)
 		return (EADDRNOTAVAIL);
 
+#ifdef notyet
+	/*
+	 * FIXME: Set interface scope in group address.
+	 */
+	(void)in6_setscope(&gsa->sin6.sin_addr, ifp, NULL);
+#endif
+
 	/*
 	 * MCAST_JOIN_SOURCE on an exclusive membership is an error.
 	 * On an existing inclusive membership, it just adds the
@@ -1987,7 +2068,23 @@ in6p_leave_group(struct inpcb *inp, struct sockopt *sopt)
 		gsa->sin6.sin6_family = AF_INET6;
 		gsa->sin6.sin6_len = sizeof(struct sockaddr_in6);
 		gsa->sin6.sin6_addr = mreq.ipv6mr_multiaddr;
-		ifp = ifnet_byindex(mreq.ipv6mr_interface);
+
+		if (mreq.ipv6mr_interface == 0) {
+#ifdef notyet
+			/*
+			 * FIXME: Resolve scope ambiguity when interface
+			 * index is unspecified.
+			 */
+			ifp = in6p_lookup_mcast_ifp(inp, &gsa->sin6);
+#else
+			return (EADDRNOTAVAIL);
+#endif
+		} else {
+			if (mreq.ipv6mr_interface < 0 ||
+			    V_if_index < mreq.ipv6mr_interface)
+				return (EADDRNOTAVAIL);
+			ifp = ifnet_byindex(mreq.ipv6mr_interface);
+		}
 
 		CTR3(KTR_MLD, "%s: ipv6mr_interface = %d, ifp = %p",
 		    __func__, mreq.ipv6mr_interface, ifp);
@@ -2033,6 +2130,15 @@ in6p_leave_group(struct inpcb *inp, struct sockopt *sopt)
 	if (!IN6_IS_ADDR_MULTICAST(&gsa->sin6.sin6_addr))
 		return (EINVAL);
 
+#ifdef notyet
+	/*
+	 * FIXME: Need to embed ifp's scope ID in the address
+	 * handed down to MLD.
+	 * See KAME IPV6_LEAVE_GROUP implementation.
+	 */
+	(void)in6_setscope(&mreq->ipv6mr_multiaddr, ifp, NULL);
+#endif
+
 	/*
 	 * Find the membership in the membership array.
 	 */
@@ -2348,7 +2454,7 @@ out_in6p_locked:
 int
 ip6_setmoptions(struct inpcb *inp, struct sockopt *sopt)
 {
-	struct ip6_moptions	*imo;
+	struct ip6_moptions	*im6o;
 	int			 error;
 
 	error = 0;
@@ -2364,7 +2470,6 @@ ip6_setmoptions(struct inpcb *inp, struct sockopt *sopt)
 
 	switch (sopt->sopt_name) {
 	case IPV6_MULTICAST_IF:
-		/* XXX in v6 this one is far more involved */
 		error = in6p_set_multicast_if(inp, sopt);
 		break;
 
@@ -2381,9 +2486,11 @@ ip6_setmoptions(struct inpcb *inp, struct sockopt *sopt)
 		if (hlim < -1 || hlim > 255) {
 			error = EINVAL;
 			break;
+		} else if (hlim == -1) {
+			hlim = V_ip6_defmcasthlim;
 		}
-		imo = in6p_findmoptions(inp);
-		imo->im6o_multicast_hlim = hlim;
+		im6o = in6p_findmoptions(inp);
+		im6o->im6o_multicast_hlim = hlim;
 		INP_WUNLOCK(inp);
 		break;
 	}
@@ -2393,9 +2500,7 @@ ip6_setmoptions(struct inpcb *inp, struct sockopt *sopt)
 
 		/*
 		 * Set the loopback flag for outgoing multicast packets.
-		 * Must be zero or one.  The orimcaddrl multicast API required a
-		 * char argument, which is inconsistent with the rest
-		 * of the socket API.  We allow either a char or an int.
+		 * Must be zero or one.
 		 */
 		if (sopt->sopt_valsize != sizeof(u_int)) {
 			error = EINVAL;
@@ -2404,8 +2509,12 @@ ip6_setmoptions(struct inpcb *inp, struct sockopt *sopt)
 		error = sooptcopyin(sopt, &loop, sizeof(u_int), sizeof(u_int));
 		if (error)
 			break;
-		imo = in6p_findmoptions(inp);
-		imo->im6o_multicast_loop = loop;
+		if (loop > 1) {
+			error = EINVAL;
+			break;
+		}
+		im6o = in6p_findmoptions(inp);
+		im6o->im6o_multicast_loop = loop;
 		INP_WUNLOCK(inp);
 		break;
 	}
diff --git a/sys/netinet6/in6_pcb.c b/sys/netinet6/in6_pcb.c
index 79e79cb..e446a05 100644
--- a/sys/netinet6/in6_pcb.c
+++ b/sys/netinet6/in6_pcb.c
@@ -733,36 +733,36 @@ in6_pcbpurgeif0(struct inpcbinfo *pcbinfo, struct ifnet *ifp)
 {
 	struct inpcb *in6p;
 	struct ip6_moptions *im6o;
-	struct in6_multi_mship *imm, *nimm;
+	int i, gap;
 
 	INP_INFO_RLOCK(pcbinfo);
 	LIST_FOREACH(in6p, pcbinfo->ipi_listhead, inp_list) {
 		INP_WLOCK(in6p);
 		im6o = in6p->in6p_moptions;
-		if ((in6p->inp_vflag & INP_IPV6) &&
-		    im6o) {
+		if ((in6p->inp_vflag & INP_IPV6) && im6o != NULL) {
 			/*
-			 * Unselect the outgoing interface if it is being
-			 * detached.
+			 * Unselect the outgoing ifp for multicast if it
+			 * is being detached.
 			 */
 			if (im6o->im6o_multicast_ifp == ifp)
 				im6o->im6o_multicast_ifp = NULL;
-
 			/*
 			 * Drop multicast group membership if we joined
 			 * through the interface being detached.
-			 * XXX controversial - is it really legal for kernel
-			 * to force this?
 			 */
-			for (imm = im6o->im6o_memberships.lh_first;
-			     imm != NULL; imm = nimm) {
-				nimm = imm->i6mm_chain.le_next;
-				if (imm->i6mm_maddr->in6m_ifp == ifp) {
-					LIST_REMOVE(imm, i6mm_chain);
-					in6_delmulti(imm->i6mm_maddr);
-					free(imm, M_IP6MADDR);
+			gap = 0;
+			for (i = 0; i < im6o->im6o_num_memberships; i++) {
+				if (im6o->im6o_membership[i]->in6m_ifp ==
+				    ifp) {
+					in6_mc_leave(im6o->im6o_membership[i],
+					    NULL);
+					gap++;
+				} else if (gap != 0) {
+					im6o->im6o_membership[i - gap] =
+					    im6o->im6o_membership[i];
 				}
 			}
+			im6o->im6o_num_memberships -= gap;
 		}
 		INP_WUNLOCK(in6p);
 	}
diff --git a/sys/netinet6/in6_proto.c b/sys/netinet6/in6_proto.c
index 8908d67..622777c 100644
--- a/sys/netinet6/in6_proto.c
+++ b/sys/netinet6/in6_proto.c
@@ -236,6 +236,7 @@ struct ip6protosw inet6sw[] = {
 	.pr_ctloutput =		rip6_ctloutput,
 	.pr_init =		icmp6_init,
 	.pr_fasttimo =		icmp6_fasttimo,
+	.pr_slowtimo =		icmp6_slowtimo,
 	.pr_usrreqs =		&rip6_usrreqs
 },
 {
diff --git a/sys/netinet6/in6_var.h b/sys/netinet6/in6_var.h
index a472a24..9a846c3 100644
--- a/sys/netinet6/in6_var.h
+++ b/sys/netinet6/in6_var.h
@@ -64,6 +64,12 @@
 #ifndef _NETINET6_IN6_VAR_H_
 #define _NETINET6_IN6_VAR_H_
 
+#include <sys/tree.h>
+
+#ifdef _KERNEL
+#include <sys/libkern.h>
+#endif
+
 /*
  * Interface address, Internet version.  One of these structures
  * is allocated for each interface with an Internet address.
@@ -89,12 +95,15 @@ struct in6_addrlifetime {
 struct nd_ifinfo;
 struct scope6_id;
 struct lltable;
+struct mld_ifinfo;
+
 struct in6_ifextra {
 	struct in6_ifstat *in6_ifstat;
 	struct icmp6_ifstat *icmp6_ifstat;
 	struct nd_ifinfo *nd_ifinfo;
 	struct scope6_id *scope6_id;
 	struct lltable *lltable;
+	struct mld_ifinfo *mld_ifinfo;
 };
 
 #define	LLTABLE6(ifp)	(((struct in6_ifextra *)(ifp)->if_afdata[AF_INET6])->lltable)
@@ -489,9 +498,6 @@ do {								\
 
 extern struct in6_addr zeroin6_addr;
 extern u_char inet6ctlerrmap[];
-#ifdef MALLOC_DECLARE
-MALLOC_DECLARE(M_IP6MADDR);
-#endif /* MALLOC_DECLARE */
 
 /*
  * Macro for finding the internet address structure (in6_ifaddr) corresponding
@@ -514,94 +520,243 @@ do {									\
 #endif /* _KERNEL */
 
 /*
- * Multi-cast membership entry.  One for each group/ifp that a PCB
- * belongs to.
+ * IPv6 multicast MLD-layer source entry.
+ */
+struct ip6_msource {
+	RB_ENTRY(ip6_msource)	im6s_link;	/* RB tree links */
+	struct in6_addr		im6s_addr;
+	struct im6s_st {
+		uint16_t	ex;		/* # of exclusive members */
+		uint16_t	in;		/* # of inclusive members */
+	}			im6s_st[2];	/* state at t0, t1 */
+	uint8_t			im6s_stp;	/* pending query */
+};
+RB_HEAD(ip6_msource_tree, ip6_msource);
+
+/*
+ * IPv6 multicast PCB-layer source entry.
+ *
+ * NOTE: overlapping use of struct ip6_msource fields at start.
+ */
+struct in6_msource {
+	RB_ENTRY(ip6_msource)	im6s_link;	/* Common field */
+	struct in6_addr		im6s_addr;	/* Common field */
+	uint8_t			im6sl_st[2];	/* state before/at commit */
+};
+
+#ifdef _KERNEL
+/*
+ * IPv6 source tree comparison function.
+ *
+ * An ordered predicate is necessary; bcmp() is not documented to return
+ * an indication of order, memcmp() is, and is an ISO C99 requirement.
+ */
+static __inline int
+ip6_msource_cmp(const struct ip6_msource *a, const struct ip6_msource *b)
+{
+
+	return (memcmp(&a->im6s_addr, &b->im6s_addr, sizeof(struct in6_addr)));
+}
+RB_PROTOTYPE(ip6_msource_tree, ip6_msource, im6s_link, ip6_msource_cmp);
+#endif /* _KERNEL */
+
+/*
+ * IPv6 multicast PCB-layer group filter descriptor.
+ */
+struct in6_mfilter {
+	struct ip6_msource_tree	im6f_sources; /* source list for (S,G) */
+	u_long			im6f_nsrc;    /* # of source entries */
+	uint8_t			im6f_st[2];   /* state before/at commit */
+};
+
+/*
+ * Legacy KAME IPv6 multicast membership descriptor.
  */
 struct in6_multi_mship {
-	struct	in6_multi *i6mm_maddr;	/* Multicast address pointer */
-	LIST_ENTRY(in6_multi_mship) i6mm_chain;  /* multicast options chain */
+	struct	in6_multi *i6mm_maddr;
+	LIST_ENTRY(in6_multi_mship) i6mm_chain;
 };
 
-struct	in6_multi {
+/*
+ * IPv6 group descriptor.
+ *
+ * For every entry on an ifnet's if_multiaddrs list which represents
+ * an IP multicast group, there is one of these structures.
+ *
+ * If any source filters are present, then a node will exist in the RB-tree
+ * to permit fast lookup by source whenever an operation takes place.
+ * This permits pre-order traversal when we issue reports.
+ * Source filter trees are kept separately from the socket layer to
+ * greatly simplify locking.
+ *
+ * When MLDv2 is active, in6m_timer is the response to group query timer.
+ * The state-change timer in6m_sctimer is separate; whenever state changes
+ * for the group the state change record is generated and transmitted,
+ * and kept if retransmissions are necessary.
+ *
+ * FUTURE: in6m_link is now only used when groups are being purged
+ * on a detaching ifnet. It could be demoted to a SLIST_ENTRY, but
+ * because it is at the very start of the struct, we can't do this
+ * w/o breaking the ABI for ifmcstat.
+ */
+struct in6_multi {
 	LIST_ENTRY(in6_multi) in6m_entry; /* list glue */
-	struct	in6_addr in6m_addr;	/* IP6 multicast address */
+	struct	in6_addr in6m_addr;	/* IPv6 multicast address */
 	struct	ifnet *in6m_ifp;	/* back pointer to ifnet */
 	struct	ifmultiaddr *in6m_ifma;	/* back pointer to ifmultiaddr */
-	u_int	in6m_refcount;		/* # membership claims by sockets */
+	u_int	in6m_refcount;		/* reference count */
 	u_int	in6m_state;		/* state of the membership */
 	u_int	in6m_timer;		/* MLD6 listener report timer */
-	struct timeval in6m_timer_expire; /* when the timer expires */
-	struct callout *in6m_timer_ch;
-};
 
-#define IN6M_TIMER_UNDEF -1
+	/* New fields for MLDv2 follow. */
+	struct mld_ifinfo	*in6m_mli;	/* MLD info */
+	SLIST_ENTRY(in6_multi)	 in6m_nrele;	/* to-be-released by MLD */
+	struct ip6_msource_tree	 in6m_srcs;	/* tree of sources */
+	u_long			 in6m_nsrc;	/* # of tree entries */
 
-#ifdef _KERNEL
-/* flags to in6_update_ifa */
-#define IN6_IFAUPDATE_DADDELAY	0x1 /* first time to configure an address */
+	struct ifqueue		 in6m_scq;	/* queue of pending
+						 * state-change packets */
+	struct timeval		 in6m_lastgsrtv;	/* last G-S-R query */
+	uint16_t		 in6m_sctimer;	/* state-change timer */
+	uint16_t		 in6m_scrv;	/* state-change rexmit count */
 
-extern LIST_HEAD(in6_multihead, in6_multi) in6_multihead;
+	/*
+	 * SSM state counters which track state at T0 (the time the last
+	 * state-change report's RV timer went to zero) and T1
+	 * (time of pending report, i.e. now).
+	 * Used for computing MLDv2 state-change reports. Several refcounts
+	 * are maintained here to optimize for common use-cases.
+	 */
+	struct in6m_st {
+		uint16_t	iss_fmode;	/* MLD filter mode */
+		uint16_t	iss_asm;	/* # of ASM listeners */
+		uint16_t	iss_ex;		/* # of exclusive members */
+		uint16_t	iss_in;		/* # of inclusive members */
+		uint16_t	iss_rec;	/* # of recorded sources */
+	}			in6m_st[2];	/* state at t0, t1 */
+};
 
 /*
- * Structure used by macros below to remember position when stepping through
- * all of the in6_multi records.
+ * Helper function to derive the filter mode on a source entry
+ * from its internal counters. Predicates are:
+ *  A source is only excluded if all listeners exclude it.
+ *  A source is only included if no listeners exclude it,
+ *  and at least one listener includes it.
+ * May be used by ifmcstat(8).
  */
-struct	in6_multistep {
-	struct	in6_ifaddr *i_ia;
-	struct	in6_multi *i_in6m;
-};
+static __inline uint8_t
+im6s_get_mode(const struct in6_multi *inm, const struct ip6_msource *ims,
+    uint8_t t)
+{
+
+	t = !!t;
+	if (inm->in6m_st[t].iss_ex > 0 &&
+	    inm->in6m_st[t].iss_ex == ims->im6s_st[t].ex)
+		return (MCAST_EXCLUDE);
+	else if (ims->im6s_st[t].in > 0 && ims->im6s_st[t].ex == 0)
+		return (MCAST_INCLUDE);
+	return (MCAST_UNDEFINED);
+}
+
+#ifdef _KERNEL
 
 /*
- * Macros for looking up the in6_multi record for a given IP6 multicast
- * address on a given interface. If no matching record is found, "in6m"
- * returns NULL.
+ * Lock macros for IPv6 layer multicast address lists.  IPv6 lock goes
+ * before link layer multicast locks in the lock order.  In most cases,
+ * consumers of IN_*_MULTI() macros should acquire the locks before
+ * calling them; users of the in_{add,del}multi() functions should not.
  */
+extern struct mtx in6_multi_mtx;
+#define	IN6_MULTI_LOCK()		mtx_lock(&in6_multi_mtx)
+#define	IN6_MULTI_UNLOCK()		mtx_unlock(&in6_multi_mtx)
+#define	IN6_MULTI_LOCK_ASSERT()		mtx_assert(&in6_multi_mtx, MA_OWNED)
+#define	IN6_MULTI_UNLOCK_ASSERT()	mtx_assert(&in6_multi_mtx, MA_NOTOWNED)
 
-#define IN6_LOOKUP_MULTI(addr, ifp, in6m)			\
-/* struct in6_addr addr; */					\
-/* struct ifnet *ifp; */					\
-/* struct in6_multi *in6m; */					\
-do { \
-	struct ifmultiaddr *ifma; \
-	IF_ADDR_LOCK(ifp); \
-	TAILQ_FOREACH(ifma, &(ifp)->if_multiaddrs, ifma_link) { \
-		if (ifma->ifma_addr->sa_family == AF_INET6 \
-		    && IN6_ARE_ADDR_EQUAL(&((struct sockaddr_in6 *)ifma->ifma_addr)->sin6_addr, \
-					  &(addr))) \
-			break; \
-	} \
-	(in6m) = (struct in6_multi *)(ifma ? ifma->ifma_protospec : 0); \
-	IF_ADDR_UNLOCK(ifp); \
-} while(0)
+/*
+ * Look up an in6_multi record for an IPv6 multicast address
+ * on the interface ifp.
+ * If no record found, return NULL.
+ *
+ * SMPng: The IN6_MULTI_LOCK and IF_ADDR_LOCK on ifp must be held.
+ */
+static __inline struct in6_multi *
+in6m_lookup_locked(struct ifnet *ifp, const struct in6_addr *mcaddr)
+{
+	struct ifmultiaddr *ifma;
+	struct in6_multi *inm;
+
+	IN6_MULTI_LOCK_ASSERT();
+	IF_ADDR_LOCK_ASSERT(ifp);
+
+	inm = NULL;
+	TAILQ_FOREACH(ifma, &((ifp)->if_multiaddrs), ifma_link) {
+		if (ifma->ifma_addr->sa_family == AF_INET6) {
+			inm = (struct in6_multi *)ifma->ifma_protospec;
+			if (IN6_ARE_ADDR_EQUAL(&inm->in6m_addr, mcaddr))
+				break;
+			inm = NULL;
+		}
+	}
+	return (inm);
+}
 
 /*
- * Macro to step through all of the in6_multi records, one at a time.
- * The current position is remembered in "step", which the caller must
- * provide.  IN6_FIRST_MULTI(), below, must be called to initialize "step"
- * and get the first record.  Both macros return a NULL "in6m" when there
- * are no remaining records.
+ * Wrapper for in6m_lookup_locked().
+ *
+ * SMPng: Assumes that neithr the IN6_MULTI_LOCK() or IF_ADDR_LOCK() are held.
  */
-#define IN6_NEXT_MULTI(step, in6m)					\
-/* struct in6_multistep step; */					\
-/* struct in6_multi *in6m; */						\
-do { \
-	if (((in6m) = (step).i_in6m) != NULL) \
-		(step).i_in6m = LIST_NEXT((step).i_in6m, in6m_entry); \
-} while(0)
-
-#define IN6_FIRST_MULTI(step, in6m)		\
-/* struct in6_multistep step; */		\
-/* struct in6_multi *in6m */			\
-do { \
-	(step).i_in6m = LIST_FIRST(&in6_multihead); \
-		IN6_NEXT_MULTI((step), (in6m)); \
-} while(0)
-
-struct	in6_multi *in6_addmulti __P((struct in6_addr *, struct ifnet *,
-	int *, int));
-void	in6_delmulti __P((struct in6_multi *));
-struct in6_multi_mship *in6_joingroup(struct ifnet *, struct in6_addr *, int *, int);
+static __inline struct in6_multi *
+in6m_lookup(struct ifnet *ifp, const struct in6_addr *mcaddr)
+{
+	struct in6_multi *inm;
+
+	IN6_MULTI_LOCK();
+	IF_ADDR_LOCK(ifp);
+	inm = in6m_lookup_locked(ifp, mcaddr);
+	IF_ADDR_UNLOCK(ifp);
+	IN6_MULTI_UNLOCK();
+
+	return (inm);
+}
+
+/* Acquire an in6_multi record. */
+static __inline void
+in6m_acquire_locked(struct in6_multi *inm)
+{
+
+	IN6_MULTI_LOCK_ASSERT();
+	++inm->in6m_refcount;
+}
+
+struct ip6_moptions;
+struct sockopt;
+
+/* Multicast KPIs. */
+int	im6o_mc_filter(const struct ip6_moptions *, const struct ifnet *,
+	    const struct sockaddr *, const struct sockaddr *);
+int	in6_mc_join(struct ifnet *, const struct in6_addr *,
+	    struct in6_mfilter *, struct in6_multi **, int);
+int	in6_mc_join_locked(struct ifnet *, const struct in6_addr *,
+	    struct in6_mfilter *, struct in6_multi **, int);
+int	in6_mc_leave(struct in6_multi *, struct in6_mfilter *);
+int	in6_mc_leave_locked(struct in6_multi *, struct in6_mfilter *);
+void	in6m_clear_recorded(struct in6_multi *);
+void	in6m_commit(struct in6_multi *);
+void	in6m_print(const struct in6_multi *);
+int	in6m_record_source(struct in6_multi *, const struct in6_addr *);
+void	in6m_release_locked(struct in6_multi *);
+void	ip6_freemoptions(struct ip6_moptions *);
+int	ip6_getmoptions(struct inpcb *, struct sockopt *);
+int	ip6_setmoptions(struct inpcb *, struct sockopt *);
+
+/* Legacy KAME multicast KPIs. */
+struct in6_multi_mship *
+	in6_joingroup(struct ifnet *, struct in6_addr *, int *, int);
 int	in6_leavegroup(struct in6_multi_mship *);
+
+/* flags to in6_update_ifa */
+#define IN6_IFAUPDATE_DADDELAY	0x1 /* first time to configure an address */
+
 int	in6_mask2len __P((struct in6_addr *, u_char *));
 int	in6_control __P((struct socket *, u_long, caddr_t, struct ifnet *,
 	struct thread *));
@@ -615,8 +770,6 @@ void	*in6_domifattach __P((struct ifnet *));
 void	in6_domifdetach __P((struct ifnet *, void *));
 void	in6_setmaxmtu   __P((void));
 int	in6_if2idlen   __P((struct ifnet *));
-void	in6_restoremkludge __P((struct in6_ifaddr *, struct ifnet *));
-void	in6_purgemkludge __P((struct ifnet *));
 struct in6_ifaddr *in6ifa_ifpforlinklocal __P((struct ifnet *, int));
 struct in6_ifaddr *in6ifa_ifpwithaddr __P((struct ifnet *, struct in6_addr *));
 char	*ip6_sprintf __P((char *, const struct in6_addr *));
diff --git a/sys/netinet6/ip6_input.c b/sys/netinet6/ip6_input.c
index 5654c94..69ac45c 100644
--- a/sys/netinet6/ip6_input.c
+++ b/sys/netinet6/ip6_input.c
@@ -555,25 +555,12 @@ passin:
 	}
 
 	/*
-	 * Multicast check
+	 * Multicast check. Assume packet is for us to avoid
+	 * prematurely taking locks.
 	 */
 	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
-		struct in6_multi *in6m = 0;
-
+		ours = 1;
 		in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast);
-		/*
-		 * See if we belong to the destination multicast group on the
-		 * arrival interface.
-		 */
-		IN6_LOOKUP_MULTI(ip6->ip6_dst, m->m_pkthdr.rcvif, in6m);
-		if (in6m)
-			ours = 1;
-		else if (!ip6_mrouter) {
-			V_ip6stat.ip6s_notmember++;
-			V_ip6stat.ip6s_cantforward++;
-			in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
-			goto bad;
-		}
 		deliverifp = m->m_pkthdr.rcvif;
 		goto hbhcheck;
 	}
@@ -823,7 +810,8 @@ passin:
 	/*
 	 * Forward if desirable.
 	 */
-	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
+	if (V_ip6_mrouter &&
+	    IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 		/*
 		 * If we are acting as a multicast router, all
 		 * incoming multicast packets are passed to the
@@ -832,13 +820,12 @@ passin:
 		 * ip6_mforward() returns a non-zero value, the packet
 		 * must be discarded, else it may be accepted below.
 		 */
-		if (ip6_mrouter && ip6_mforward &&
+		if (ip6_mforward &&
 		    ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) {
-			V_ip6stat.ip6s_cantforward++;
+			IP6STAT_INC(ip6s_cantforward);
+			in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
 			goto bad;
 		}
-		if (!ours)
-			goto bad;
 	} else if (!ours) {
 		ip6_forward(m, srcrt);
 		goto out;
diff --git a/sys/netinet6/ip6_mroute.c b/sys/netinet6/ip6_mroute.c
index 29201d6..a88a9a1 100644
--- a/sys/netinet6/ip6_mroute.c
+++ b/sys/netinet6/ip6_mroute.c
@@ -93,6 +93,7 @@ __FBSDID("$FreeBSD$");
 #include <sys/malloc.h>
 #include <sys/mbuf.h>
 #include <sys/module.h>
+#include <sys/domain.h>
 #include <sys/protosw.h>
 #include <sys/signalvar.h>
 #include <sys/socket.h>
@@ -140,6 +141,7 @@ static int	set_pim6(int *);
 static int	socket_send(struct socket *, struct mbuf *,
 		    struct sockaddr_in6 *);
 
+extern int in6_mcast_loop;
 extern struct domain inet6domain;
 
 static const struct encaptab *pim6_encap_cookie;
@@ -367,7 +369,7 @@ X_ip6_mrouter_set(struct socket *so, struct sockopt *sopt)
 	struct mf6cctl mfcc;
 	mifi_t mifi;
 
-	if (so != ip6_mrouter && sopt->sopt_name != MRT6_INIT)
+	if (so != V_ip6_mrouter && sopt->sopt_name != MRT6_INIT)
 		return (EACCES);
 
 	switch (sopt->sopt_name) {
@@ -432,7 +434,7 @@ X_ip6_mrouter_get(struct socket *so, struct sockopt *sopt)
 	INIT_VNET_INET6(curvnet);
 	int error = 0;
 
-	if (so != ip6_mrouter)
+	if (so != V_ip6_mrouter)
 		return (EACCES);
 
 	switch (sopt->sopt_name) {
@@ -560,12 +562,12 @@ ip6_mrouter_init(struct socket *so, int v, int cmd)
 
 	MROUTER6_LOCK();
 
-	if (ip6_mrouter != NULL) {
+	if (V_ip6_mrouter != NULL) {
 		MROUTER6_UNLOCK();
 		return (EADDRINUSE);
 	}
 
-	ip6_mrouter = so;
+	V_ip6_mrouter = so;
 	V_ip6_mrouter_ver = cmd;
 
 	bzero((caddr_t)mf6ctable, sizeof(mf6ctable));
@@ -601,7 +603,7 @@ X_ip6_mrouter_done(void)
 
 	MROUTER6_LOCK();
 
-	if (ip6_mrouter == NULL) {
+	if (V_ip6_mrouter == NULL) {
 		MROUTER6_UNLOCK();
 		return (EINVAL);
 	}
@@ -657,7 +659,7 @@ X_ip6_mrouter_done(void)
 		multicast_register_if6 = NULL;
 	}
 
-	ip6_mrouter = NULL;
+	V_ip6_mrouter = NULL;
 	V_ip6_mrouter_ver = 0;
 
 	MROUTER6_UNLOCK();
@@ -1293,7 +1295,7 @@ X_ip6_mforward(struct ip6_hdr *ip6, struct ifnet *ifp, struct mbuf *m)
 				break;
 			}
 
-			if (socket_send(ip6_mrouter, mm, &sin6) < 0) {
+			if (socket_send(V_ip6_mrouter, mm, &sin6) < 0) {
 				log(LOG_WARNING, "ip6_mforward: ip6_mrouter "
 				    "socket queue full\n");
 				mrt6stat.mrt6s_upq_sockfull++;
@@ -1531,7 +1533,7 @@ ip6_mdq(struct mbuf *m, struct ifnet *ifp, struct mf6c *rt)
 
 				mrt6stat.mrt6s_upcalls++;
 
-				if (socket_send(ip6_mrouter, mm, &sin6) < 0) {
+				if (socket_send(V_ip6_mrouter, mm, &sin6) < 0) {
 #ifdef MRT6DEBUG
 					if (V_mrt6debug)
 						log(LOG_WARNING, "mdq, ip6_mrouter socket queue full\n");
@@ -1603,10 +1605,11 @@ phyint_send(struct ip6_hdr *ip6, struct mif6 *mifp, struct mbuf *m)
 	struct mbuf *mb_copy;
 	struct ifnet *ifp = mifp->m6_ifp;
 	int error = 0;
-	struct	in6_multi *in6m;
 	struct sockaddr_in6 *dst6;
 	u_long linkmtu;
 
+	dst6 = &mifp->m6_route.ro_dst;
+
 	/*
 	 * Make a new reference to the packet; make sure that
 	 * the IPv6 header is actually copied, not just referenced,
@@ -1648,17 +1651,16 @@ phyint_send(struct ip6_hdr *ip6, struct mif6 *mifp, struct mbuf *m)
 	}
 
 	/*
-	 * If we belong to the destination multicast group
-	 * on the outgoing interface, loop back a copy.
+	 * If configured to loop back multicasts by default,
+	 * loop back a copy now.
 	 */
-	dst6 = &mifp->m6_route.ro_dst;
-	IN6_LOOKUP_MULTI(ip6->ip6_dst, ifp, in6m);
-	if (in6m != NULL) {
+	if (in6_mcast_loop) {
 		dst6->sin6_len = sizeof(struct sockaddr_in6);
 		dst6->sin6_family = AF_INET6;
 		dst6->sin6_addr = ip6->ip6_dst;
 		ip6_mloopback(ifp, m, &mifp->m6_route.ro_dst);
 	}
+
 	/*
 	 * Put the packet into the sending queue of the outgoing interface
 	 * if it would fit in the MTU of the interface.
@@ -1759,7 +1761,7 @@ register_send(struct ip6_hdr *ip6, struct mif6 *mif, struct mbuf *m)
 	/* iif info is not given for reg. encap.n */
 	mrt6stat.mrt6s_upcalls++;
 
-	if (socket_send(ip6_mrouter, mm, &sin6) < 0) {
+	if (socket_send(V_ip6_mrouter, mm, &sin6) < 0) {
 #ifdef MRT6DEBUG
 		if (V_mrt6debug)
 			log(LOG_WARNING,
@@ -2056,7 +2058,7 @@ ip6_mroute_modevent(module_t mod, int type, void *unused)
 		break;
 
 	case MOD_UNLOAD:
-		if (ip6_mrouter != NULL)
+		if (V_ip6_mrouter != NULL)
 			return EINVAL;
 
 		if (pim6_encap_cookie) {
diff --git a/sys/netinet6/ip6_output.c b/sys/netinet6/ip6_output.c
index 787bc12..61804ec 100644
--- a/sys/netinet6/ip6_output.c
+++ b/sys/netinet6/ip6_output.c
@@ -110,7 +110,7 @@ __FBSDID("$FreeBSD$");
 #include <netinet6/scope6_var.h>
 #include <netinet6/vinet6.h>
 
-static MALLOC_DEFINE(M_IP6MOPTS, "ip6_moptions", "internet multicast options");
+extern int in6_mcast_loop;
 
 struct ip6_exthdrs {
 	struct mbuf *ip6e_ip6;
@@ -128,8 +128,6 @@ static int ip6_getpcbopt(struct ip6_pktopts *, int, struct sockopt *);
 static int ip6_setpktopt __P((int, u_char *, int, struct ip6_pktopts *,
 	struct ucred *, int, int, int));
 
-static int ip6_setmoptions(int, struct ip6_moptions **, struct mbuf *);
-static int ip6_getmoptions(int, struct ip6_moptions *, struct mbuf **);
 static int ip6_copyexthdr(struct mbuf **, caddr_t, int);
 static int ip6_insertfraghdr __P((struct mbuf *, struct mbuf *, int,
 	struct ip6_frag **));
@@ -692,12 +690,8 @@ again:
 	if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 		m->m_flags &= ~(M_BCAST | M_MCAST); /* just in case */
 	} else {
-		struct	in6_multi *in6m;
-
 		m->m_flags = (m->m_flags & ~M_BCAST) | M_MCAST;
-
 		in6_ifstat_inc(ifp, ifs6_out_mcast);
-
 		/*
 		 * Confirm that the outgoing interface supports multicast.
 		 */
@@ -707,13 +701,14 @@ again:
 			error = ENETUNREACH;
 			goto bad;
 		}
-		IN6_LOOKUP_MULTI(ip6->ip6_dst, ifp, in6m);
-		if (in6m != NULL &&
-		   (im6o == NULL || im6o->im6o_multicast_loop)) {
+		if ((im6o == NULL && in6_mcast_loop) ||
+		    (im6o && im6o->im6o_multicast_loop)) {
 			/*
-			 * If we belong to the destination multicast group
-			 * on the outgoing interface, and the caller did not
-			 * forbid loopback, loop back a copy.
+			 * Loop back multicast datagram if not expressly
+			 * forbidden to do so, even if we have not joined
+			 * the address; protocols will filter it later,
+			 * thus deferring a hash lookup and lock acquisition
+			 * at the expense of an m_copym().
 			 */
 			ip6_mloopback(ifp, m, dst);
 		} else {
@@ -729,7 +724,7 @@ again:
 			 * above, will be forwarded by the ip6_input() routine,
 			 * if necessary.
 			 */
-			if (ip6_mrouter && (flags & IPV6_FORWARDING) == 0) {
+			if (V_ip6_mrouter && (flags & IPV6_FORWARDING) == 0) {
 				/*
 				 * XXX: ip6_mforward expects that rcvif is NULL
 				 * when it is called from the originating path.
@@ -1702,47 +1697,14 @@ do { \
 			case IPV6_MULTICAST_LOOP:
 			case IPV6_JOIN_GROUP:
 			case IPV6_LEAVE_GROUP:
-			    {
-				if (sopt->sopt_valsize > MLEN) {
-					error = EMSGSIZE;
-					break;
-				}
-				/* XXX */
-			    }
-			    /* FALLTHROUGH */
-			    {
-				struct mbuf *m;
-
-				if (sopt->sopt_valsize > MCLBYTES) {
-					error = EMSGSIZE;
-					break;
-				}
-				/* XXX */
-				MGET(m, sopt->sopt_td ? M_WAIT : M_DONTWAIT, MT_DATA);
-				if (m == 0) {
-					error = ENOBUFS;
-					break;
-				}
-				if (sopt->sopt_valsize > MLEN) {
-					MCLGET(m, sopt->sopt_td ? M_WAIT : M_DONTWAIT);
-					if ((m->m_flags & M_EXT) == 0) {
-						m_free(m);
-						error = ENOBUFS;
-						break;
-					}
-				}
-				m->m_len = sopt->sopt_valsize;
-				error = sooptcopyin(sopt, mtod(m, char *),
-						    m->m_len, m->m_len);
-				if (error) {
-					(void)m_free(m);
-					break;
-				}
-				error =	ip6_setmoptions(sopt->sopt_name,
-							&in6p->in6p_moptions,
-							m);
-				(void)m_free(m);
-			    }
+			case IPV6_MSFILTER:
+			case MCAST_BLOCK_SOURCE:
+			case MCAST_UNBLOCK_SOURCE:
+			case MCAST_JOIN_GROUP:
+			case MCAST_LEAVE_GROUP:
+			case MCAST_JOIN_SOURCE_GROUP:
+			case MCAST_LEAVE_SOURCE_GROUP:
+				error = ip6_setmoptions(in6p, sopt);
 				break;
 
 			case IPV6_PORTRANGE:
@@ -1974,17 +1936,8 @@ do { \
 			case IPV6_MULTICAST_IF:
 			case IPV6_MULTICAST_HOPS:
 			case IPV6_MULTICAST_LOOP:
-			case IPV6_JOIN_GROUP:
-			case IPV6_LEAVE_GROUP:
-			    {
-				struct mbuf *m;
-				error = ip6_getmoptions(sopt->sopt_name,
-				    in6p->in6p_moptions, &m);
-				if (error == 0)
-					error = sooptcopyout(sopt,
-					    mtod(m, char *), m->m_len);
-				m_freem(m);
-			    }
+			case IPV6_MSFILTER:
+				error = ip6_getmoptions(in6p, sopt);
 				break;
 
 #ifdef IPSEC
@@ -2405,374 +2358,6 @@ ip6_freepcbopts(struct ip6_pktopts *pktopt)
 }
 
 /*
- * Set the IP6 multicast options in response to user setsockopt().
- */
-static int
-ip6_setmoptions(int optname, struct ip6_moptions **im6op, struct mbuf *m)
-{
-	INIT_VNET_NET(curvnet);
-	INIT_VNET_INET6(curvnet);
-	int error = 0;
-	u_int loop, ifindex;
-	struct ipv6_mreq *mreq;
-	struct ifnet *ifp;
-	struct ip6_moptions *im6o = *im6op;
-	struct route_in6 ro;
-	struct in6_multi_mship *imm;
-
-	if (im6o == NULL) {
-		/*
-		 * No multicast option buffer attached to the pcb;
-		 * allocate one and initialize to default values.
-		 */
-		im6o = (struct ip6_moptions *)
-			malloc(sizeof(*im6o), M_IP6MOPTS, M_WAITOK);
-
-		if (im6o == NULL)
-			return (ENOBUFS);
-		*im6op = im6o;
-		im6o->im6o_multicast_ifp = NULL;
-		im6o->im6o_multicast_hlim = V_ip6_defmcasthlim;
-		im6o->im6o_multicast_loop = IPV6_DEFAULT_MULTICAST_LOOP;
-		LIST_INIT(&im6o->im6o_memberships);
-	}
-
-	switch (optname) {
-
-	case IPV6_MULTICAST_IF:
-		/*
-		 * Select the interface for outgoing multicast packets.
-		 */
-		if (m == NULL || m->m_len != sizeof(u_int)) {
-			error = EINVAL;
-			break;
-		}
-		bcopy(mtod(m, u_int *), &ifindex, sizeof(ifindex));
-		if (ifindex < 0 || V_if_index < ifindex) {
-			error = ENXIO;	/* XXX EINVAL? */
-			break;
-		}
-		ifp = ifnet_byindex(ifindex);
-		if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) {
-			error = EADDRNOTAVAIL;
-			break;
-		}
-		im6o->im6o_multicast_ifp = ifp;
-		break;
-
-	case IPV6_MULTICAST_HOPS:
-	    {
-		/*
-		 * Set the IP6 hoplimit for outgoing multicast packets.
-		 */
-		int optval;
-		if (m == NULL || m->m_len != sizeof(int)) {
-			error = EINVAL;
-			break;
-		}
-		bcopy(mtod(m, u_int *), &optval, sizeof(optval));
-		if (optval < -1 || optval >= 256)
-			error = EINVAL;
-		else if (optval == -1)
-			im6o->im6o_multicast_hlim = V_ip6_defmcasthlim;
-		else
-			im6o->im6o_multicast_hlim = optval;
-		break;
-	    }
-
-	case IPV6_MULTICAST_LOOP:
-		/*
-		 * Set the loopback flag for outgoing multicast packets.
-		 * Must be zero or one.
-		 */
-		if (m == NULL || m->m_len != sizeof(u_int)) {
-			error = EINVAL;
-			break;
-		}
-		bcopy(mtod(m, u_int *), &loop, sizeof(loop));
-		if (loop > 1) {
-			error = EINVAL;
-			break;
-		}
-		im6o->im6o_multicast_loop = loop;
-		break;
-
-	case IPV6_JOIN_GROUP:
-		/*
-		 * Add a multicast group membership.
-		 * Group must be a valid IP6 multicast address.
-		 */
-		if (m == NULL || m->m_len != sizeof(struct ipv6_mreq)) {
-			error = EINVAL;
-			break;
-		}
-		mreq = mtod(m, struct ipv6_mreq *);
-
-		if (IN6_IS_ADDR_UNSPECIFIED(&mreq->ipv6mr_multiaddr)) {
-			/*
-			 * We use the unspecified address to specify to accept
-			 * all multicast addresses. Only super user is allowed
-			 * to do this.
-			 */
-			/* XXX-BZ might need a better PRIV_NETINET_x for this */
-			error = priv_check(curthread, PRIV_NETINET_MROUTE);
-			if (error)
-				break;
-		} else if (!IN6_IS_ADDR_MULTICAST(&mreq->ipv6mr_multiaddr)) {
-			error = EINVAL;
-			break;
-		}
-
-		/*
-		 * If no interface was explicitly specified, choose an
-		 * appropriate one according to the given multicast address.
-		 */
-		if (mreq->ipv6mr_interface == 0) {
-			struct sockaddr_in6 *dst;
-
-			/*
-			 * Look up the routing table for the
-			 * address, and choose the outgoing interface.
-			 *   XXX: is it a good approach?
-			 */
-			ro.ro_rt = NULL;
-			dst = (struct sockaddr_in6 *)&ro.ro_dst;
-			bzero(dst, sizeof(*dst));
-			dst->sin6_family = AF_INET6;
-			dst->sin6_len = sizeof(*dst);
-			dst->sin6_addr = mreq->ipv6mr_multiaddr;
-			rtalloc((struct route *)&ro);
-			if (ro.ro_rt == NULL) {
-				error = EADDRNOTAVAIL;
-				break;
-			}
-			ifp = ro.ro_rt->rt_ifp;
-			RTFREE(ro.ro_rt);
-		} else {
-			/*
-			 * If the interface is specified, validate it.
-			 */
-			if (mreq->ipv6mr_interface < 0 ||
-			    V_if_index < mreq->ipv6mr_interface) {
-				error = ENXIO;	/* XXX EINVAL? */
-				break;
-			}
-			ifp = ifnet_byindex(mreq->ipv6mr_interface);
-			if (!ifp) {
-				error = ENXIO;	/* XXX EINVAL? */
-				break;
-			}
-		}
-
-		/*
-		 * See if we found an interface, and confirm that it
-		 * supports multicast
-		 */
-		if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) {
-			error = EADDRNOTAVAIL;
-			break;
-		}
-
-		if (in6_setscope(&mreq->ipv6mr_multiaddr, ifp, NULL)) {
-			error = EADDRNOTAVAIL; /* XXX: should not happen */
-			break;
-		}
-
-		/*
-		 * See if the membership already exists.
-		 */
-		for (imm = im6o->im6o_memberships.lh_first;
-		     imm != NULL; imm = imm->i6mm_chain.le_next)
-			if (imm->i6mm_maddr->in6m_ifp == ifp &&
-			    IN6_ARE_ADDR_EQUAL(&imm->i6mm_maddr->in6m_addr,
-					       &mreq->ipv6mr_multiaddr))
-				break;
-		if (imm != NULL) {
-			error = EADDRINUSE;
-			break;
-		}
-		/*
-		 * Everything looks good; add a new record to the multicast
-		 * address list for the given interface.
-		 */
-		imm = in6_joingroup(ifp, &mreq->ipv6mr_multiaddr,  &error, 0);
-		if (imm == NULL)
-			break;
-		LIST_INSERT_HEAD(&im6o->im6o_memberships, imm, i6mm_chain);
-		break;
-
-	case IPV6_LEAVE_GROUP:
-		/*
-		 * Drop a multicast group membership.
-		 * Group must be a valid IP6 multicast address.
-		 */
-		if (m == NULL || m->m_len != sizeof(struct ipv6_mreq)) {
-			error = EINVAL;
-			break;
-		}
-		mreq = mtod(m, struct ipv6_mreq *);
-
-		/*
-		 * If an interface address was specified, get a pointer
-		 * to its ifnet structure.
-		 */
-		if (mreq->ipv6mr_interface < 0 ||
-		    V_if_index < mreq->ipv6mr_interface) {
-			error = ENXIO;	/* XXX EINVAL? */
-			break;
-		}
-		if (mreq->ipv6mr_interface == 0)
-			ifp = NULL;
-		else
-			ifp = ifnet_byindex(mreq->ipv6mr_interface);
-
-		/* Fill in the scope zone ID */
-		if (ifp) {
-			if (in6_setscope(&mreq->ipv6mr_multiaddr, ifp, NULL)) {
-				/* XXX: should not happen */
-				error = EADDRNOTAVAIL;
-				break;
-			}
-		} else if (mreq->ipv6mr_interface != 0) {
-			/*
-			 * This case happens when the (positive) index is in
-			 * the valid range, but the corresponding interface has
-			 * been detached dynamically (XXX).
-			 */
-			error = EADDRNOTAVAIL;
-			break;
-		} else {	/* ipv6mr_interface == 0 */
-			struct sockaddr_in6 sa6_mc;
-
-			/*
-			 * The API spec says as follows:
-			 *  If the interface index is specified as 0, the
-			 *  system may choose a multicast group membership to
-			 *  drop by matching the multicast address only.
-			 * On the other hand, we cannot disambiguate the scope
-			 * zone unless an interface is provided.  Thus, we
-			 * check if there's ambiguity with the default scope
-			 * zone as the last resort.
-			 */
-			bzero(&sa6_mc, sizeof(sa6_mc));
-			sa6_mc.sin6_family = AF_INET6;
-			sa6_mc.sin6_len = sizeof(sa6_mc);
-			sa6_mc.sin6_addr = mreq->ipv6mr_multiaddr;
-			error = sa6_embedscope(&sa6_mc, V_ip6_use_defzone);
-			if (error != 0)
-				break;
-			mreq->ipv6mr_multiaddr = sa6_mc.sin6_addr;
-		}
-
-		/*
-		 * Find the membership in the membership list.
-		 */
-		for (imm = im6o->im6o_memberships.lh_first;
-		     imm != NULL; imm = imm->i6mm_chain.le_next) {
-			if ((ifp == NULL || imm->i6mm_maddr->in6m_ifp == ifp) &&
-			    IN6_ARE_ADDR_EQUAL(&imm->i6mm_maddr->in6m_addr,
-			    &mreq->ipv6mr_multiaddr))
-				break;
-		}
-		if (imm == NULL) {
-			/* Unable to resolve interface */
-			error = EADDRNOTAVAIL;
-			break;
-		}
-		/*
-		 * Give up the multicast address record to which the
-		 * membership points.
-		 */
-		LIST_REMOVE(imm, i6mm_chain);
-		in6_delmulti(imm->i6mm_maddr);
-		free(imm, M_IP6MADDR);
-		break;
-
-	default:
-		error = EOPNOTSUPP;
-		break;
-	}
-
-	/*
-	 * If all options have default values, no need to keep the mbuf.
-	 */
-	if (im6o->im6o_multicast_ifp == NULL &&
-	    im6o->im6o_multicast_hlim == V_ip6_defmcasthlim &&
-	    im6o->im6o_multicast_loop == IPV6_DEFAULT_MULTICAST_LOOP &&
-	    im6o->im6o_memberships.lh_first == NULL) {
-		free(*im6op, M_IP6MOPTS);
-		*im6op = NULL;
-	}
-
-	return (error);
-}
-
-/*
- * Return the IP6 multicast options in response to user getsockopt().
- */
-static int
-ip6_getmoptions(int optname, struct ip6_moptions *im6o, struct mbuf **mp)
-{
-	INIT_VNET_INET6(curvnet);
-	u_int *hlim, *loop, *ifindex;
-
-	*mp = m_get(M_WAIT, MT_HEADER);		/* XXX */
-
-	switch (optname) {
-
-	case IPV6_MULTICAST_IF:
-		ifindex = mtod(*mp, u_int *);
-		(*mp)->m_len = sizeof(u_int);
-		if (im6o == NULL || im6o->im6o_multicast_ifp == NULL)
-			*ifindex = 0;
-		else
-			*ifindex = im6o->im6o_multicast_ifp->if_index;
-		return (0);
-
-	case IPV6_MULTICAST_HOPS:
-		hlim = mtod(*mp, u_int *);
-		(*mp)->m_len = sizeof(u_int);
-		if (im6o == NULL)
-			*hlim = V_ip6_defmcasthlim;
-		else
-			*hlim = im6o->im6o_multicast_hlim;
-		return (0);
-
-	case IPV6_MULTICAST_LOOP:
-		loop = mtod(*mp, u_int *);
-		(*mp)->m_len = sizeof(u_int);
-		if (im6o == NULL)
-			*loop = V_ip6_defmcasthlim;
-		else
-			*loop = im6o->im6o_multicast_loop;
-		return (0);
-
-	default:
-		return (EOPNOTSUPP);
-	}
-}
-
-/*
- * Discard the IP6 multicast options.
- */
-void
-ip6_freemoptions(struct ip6_moptions *im6o)
-{
-	struct in6_multi_mship *imm;
-
-	if (im6o == NULL)
-		return;
-
-	while ((imm = im6o->im6o_memberships.lh_first) != NULL) {
-		LIST_REMOVE(imm, i6mm_chain);
-		if (imm->i6mm_maddr)
-			in6_delmulti(imm->i6mm_maddr);
-		free(imm, M_IP6MADDR);
-	}
-	free(im6o, M_IP6MOPTS);
-}
-
-/*
  * Set IPv6 outgoing packet options based on advanced API.
  */
 int
diff --git a/sys/netinet6/ip6_var.h b/sys/netinet6/ip6_var.h
index 9e8476c..313b6ca 100644
--- a/sys/netinet6/ip6_var.h
+++ b/sys/netinet6/ip6_var.h
@@ -98,11 +98,19 @@ struct	ip6asfrag {
 
 #define IP6_REASS_MBUF(ip6af) (*(struct mbuf **)&((ip6af)->ip6af_m))
 
-struct	ip6_moptions {
+/*
+ * Structure attached to inpcb.in6p_moptions and
+ * passed to ip6_output when IPv6 multicast options are in use.
+ * This structure is lazy-allocated.
+ */
+struct ip6_moptions {
 	struct	ifnet *im6o_multicast_ifp; /* ifp for outgoing multicasts */
 	u_char	im6o_multicast_hlim;	/* hoplimit for outgoing multicasts */
 	u_char	im6o_multicast_loop;	/* 1 >= hear sends if a member */
-	LIST_HEAD(, in6_multi_mship) im6o_memberships;
+	u_short	im6o_num_memberships;	/* no. memberships this socket */
+	u_short	im6o_max_memberships;	/* max memberships this socket */
+	struct	in6_multi **im6o_membership;	/* group memberships */
+	struct	in6_mfilter *im6o_mfilters;	/* source filters */
 };
 
 /*
@@ -234,6 +242,13 @@ struct	ip6stat {
 };
 
 #ifdef _KERNEL
+#define	IP6STAT_ADD(name, val)	V_ip6stat.name += (val)
+#define	IP6STAT_SUB(name, val)	V_ip6stat.name -= (val)
+#define	IP6STAT_INC(name)	IP6STAT_ADD(name, 1)
+#define	IP6STAT_DEC(name)	IP6STAT_SUB(name, 1)
+#endif
+
+#ifdef _KERNEL
 /*
  * IPv6 onion peeling state.
  * it will be initialized when we come into ip6_input().
@@ -287,10 +302,7 @@ extern int	ip6_rr_prune;		/* router renumbering prefix
 					 * walk list every 5 sec.    */
 extern int	ip6_mcast_pmtu;		/* enable pMTU discovery for multicast? */
 extern int	ip6_v6only;
-#endif /* VIMAGE_GLOBALS */
-
 extern struct socket *ip6_mrouter;	/* multicast routing daemon */
-#ifdef VIMAGE_GLOBALS
 extern int	ip6_sendredirects;	/* send IP redirects when forwarding? */
 extern int	ip6_maxfragpackets; /* Maximum packets in reassembly queue */
 extern int	ip6_maxfrags;	/* Maximum fragments in reassembly queue */
@@ -330,7 +342,7 @@ void	ip6_init __P((void));
 void	ip6_input __P((struct mbuf *));
 struct in6_ifaddr *ip6_getdstifaddr __P((struct mbuf *));
 void	ip6_freepcbopts __P((struct ip6_pktopts *));
-void	ip6_freemoptions __P((struct ip6_moptions *));
+
 int	ip6_unknown_opt __P((u_int8_t *, struct mbuf *, int));
 char *	ip6_get_prevhdr __P((struct mbuf *, int));
 int	ip6_nexthdr __P((struct mbuf *, int, int, int *));
diff --git a/sys/netinet6/mld6.c b/sys/netinet6/mld6.c
index 0d05522..17b1df8 100644
--- a/sys/netinet6/mld6.c
+++ b/sys/netinet6/mld6.c
@@ -1,6 +1,5 @@
 /*-
- * Copyright (C) 1998 WIDE Project.
- * All rights reserved.
+ * Copyright (c) 2009 Bruce Simpson.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -10,14 +9,14 @@
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
- * 3. Neither the name of the project nor the names of its contributors
- *    may be used to endorse or promote products derived from this software
- *    without specific prior written permission.
+ * 3. The name of the author may not be used to endorse or promote
+ *    products derived from this software without specific prior written
+ *    permission.
  *
- * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
@@ -75,13 +74,16 @@ __FBSDID("$FreeBSD$");
 #include <sys/mbuf.h>
 #include <sys/socket.h>
 #include <sys/protosw.h>
-#include <sys/syslog.h>
+#include <sys/sysctl.h>
 #include <sys/kernel.h>
 #include <sys/callout.h>
 #include <sys/malloc.h>
+#include <sys/module.h>
 #include <sys/vimage.h>
 
 #include <net/if.h>
+#include <net/route.h>
+#include <net/vnet.h>
 
 #include <netinet/in.h>
 #include <netinet/in_var.h>
@@ -90,568 +92,3113 @@ __FBSDID("$FreeBSD$");
 #include <netinet6/ip6_var.h>
 #include <netinet6/scope6_var.h>
 #include <netinet/icmp6.h>
+#include <netinet6/mld6.h>
 #include <netinet6/mld6_var.h>
+#include <netinet/vinet.h>
 #include <netinet6/vinet6.h>
 
+#include <security/mac/mac_framework.h>
+
+#ifndef KTR_MLD
+#define KTR_MLD KTR_INET6
+#endif
+
+static struct mld_ifinfo *
+		mli_alloc_locked(struct ifnet *);
+static void	mli_delete_locked(const struct ifnet *);
+static void	mld_dispatch_packet(struct mbuf *);
+static void	mld_dispatch_queue(struct ifqueue *, int);
+static void	mld_final_leave(struct in6_multi *, struct mld_ifinfo *);
+static void	mld_fasttimo_vnet(void);
+static int	mld_handle_state_change(struct in6_multi *,
+		    struct mld_ifinfo *);
+static int	mld_initial_join(struct in6_multi *, struct mld_ifinfo *,
+		    const int);
+#ifdef KTR
+static char *	mld_rec_type_to_str(const int);
+#endif
+static void	mld_set_version(struct mld_ifinfo *, const int);
+static void	mld_slowtimo_vnet(void);
+static void	mld_sysinit(void);
+static void	mld_sysuninit(void);
+static int	mld_v1_input_query(struct ifnet *, const struct ip6_hdr *,
+		    const struct mld_hdr *);
+static int	mld_v1_input_report(struct ifnet *, const struct ip6_hdr *,
+		    const struct mld_hdr *);
+static void	mld_v1_process_group_timer(struct in6_multi *, const int);
+static void	mld_v1_process_querier_timers(struct mld_ifinfo *);
+static int	mld_v1_transmit_report(struct in6_multi *, const int);
+static void	mld_v1_update_group(struct in6_multi *, const int);
+static void	mld_v2_cancel_link_timers(struct mld_ifinfo *);
+static void	mld_v2_dispatch_general_query(struct mld_ifinfo *);
+static struct mbuf *
+		mld_v2_encap_report(struct ifnet *, struct mbuf *);
+static int	mld_v2_enqueue_filter_change(struct ifqueue *,
+		    struct in6_multi *);
+static int	mld_v2_enqueue_group_record(struct ifqueue *,
+		    struct in6_multi *, const int, const int, const int);
+static int	mld_v2_input_query(struct ifnet *, const struct ip6_hdr *,
+		    struct mbuf *, const int, const int);
+static int	mld_v2_merge_state_changes(struct in6_multi *,
+		    struct ifqueue *);
+static void	mld_v2_process_group_timers(struct mld_ifinfo *,
+		    struct ifqueue *, struct ifqueue *,
+		    struct in6_multi *, const int);
+static int	mld_v2_process_group_query(struct in6_multi *,
+		    struct mld_ifinfo *mli, int, struct mbuf *, const int);
+static int	sysctl_mld_gsr(SYSCTL_HANDLER_ARGS);
+static int	sysctl_mld_ifinfo(SYSCTL_HANDLER_ARGS);
+
+#ifdef VIMAGE
+static vnet_attach_fn	vnet_mld_iattach;
+static vnet_detach_fn	vnet_mld_idetach;
+#else
+static int	vnet_mld_iattach(const void *);
+static int	vnet_mld_idetach(const void *);
+#endif /* VIMAGE */
+
 /*
- * Protocol constants
+ * Normative references: RFC 2710, RFC 3590, RFC 3810.
+ *
+ * Locking:
+ *  * The MLD subsystem lock ends up being system-wide for the moment,
+ *    but could be per-VIMAGE later on.
+ *  * The permitted lock order is: IN6_MULTI_LOCK, MLD_LOCK, IF_ADDR_LOCK.
+ *    Any may be taken independently; if any are held at the same
+ *    time, the above lock order must be followed.
+ *  * IN6_MULTI_LOCK covers in_multi.
+ *  * MLD_LOCK covers per-link state and any global variables in this file.
+ *  * IF_ADDR_LOCK covers if_multiaddrs, which is used for a variety of
+ *    per-link state iterators.
+ *
+ *  XXX LOR PREVENTION
+ *  A special case for IPv6 is the in6_setscope() routine. ip6_output()
+ *  will not accept an ifp; it wants an embedded scope ID, unlike
+ *  ip_output(), which happily takes the ifp given to it. The embedded
+ *  scope ID is only used by MLD to select the outgoing interface.
+ *
+ *  During interface attach and detach, MLD will take MLD_LOCK *after*
+ *  the IF_AFDATA_LOCK.
+ *  As in6_setscope() takes IF_AFDATA_LOCK then SCOPE_LOCK, we can't call
+ *  it with MLD_LOCK held without triggering an LOR. A netisr with indirect
+ *  dispatch could work around this, but we'd rather not do that, as it
+ *  can introduce other races.
+ *
+ *  As such, we exploit the fact that the scope ID is just the interface
+ *  index, and embed it in the IPv6 destination address accordingly.
+ *  This is potentially NOT VALID for MLDv1 reports, as they
+ *  are always sent to the multicast group itself; as MLDv2
+ *  reports are always sent to ff02::16, this is not an issue
+ *  when MLDv2 is in use.
+ *
+ *  This does not however eliminate the LOR when ip6_output() itself
+ *  calls in6_setscope() internally whilst MLD_LOCK is held. This will
+ *  trigger a LOR warning in WITNESS when the ifnet is detached.
+ *
+ *  The right answer is probably to make IF_AFDATA_LOCK an rwlock, given
+ *  how it's used across the network stack. Here we're simply exploiting
+ *  the fact that MLD runs at a similar layer in the stack to scope6.c.
+ *
+ * VIMAGE:
+ *  * Each in6_multi corresponds to an ifp, and each ifp corresponds
+ *    to a vnet in ifp->if_vnet.
  */
+static struct mtx		 mld_mtx;
+MALLOC_DEFINE(M_MLD, "mld", "mld state");
+
+#define	MLD_EMBEDSCOPE(pin6, zoneid) \
+	(pin6)->s6_addr16[1] = htons((zoneid) & 0xFFFF)
 
-/* denotes that the MLD max response delay field specifies time in milliseconds */
-#define MLD_TIMER_SCALE	1000
 /*
- * time between repetitions of a node's initial report of interest in a
- * multicast address(in seconds)
+ * VIMAGE-wide globals.
  */
-#define MLD_UNSOLICITED_REPORT_INTERVAL	10
-
 #ifdef VIMAGE_GLOBALS
-static struct ip6_pktopts ip6_opts;
-#endif
+struct timeval			 mld_gsrdelay;
+LIST_HEAD(, mld_ifinfo)		 mli_head;
+int				 interface_timers_running6;
+int				 state_change_timers_running6;
+int				 current_state_timers_running6;
+#endif /* VIMAGE_GLOBALS */
 
-static void mld6_sendpkt(struct in6_multi *, int, const struct in6_addr *);
-static void mld_starttimer(struct in6_multi *);
-static void mld_stoptimer(struct in6_multi *);
-static void mld_timeo(struct in6_multi *);
-static u_long mld_timerresid(struct in6_multi *);
+SYSCTL_DECL(_net_inet6);	/* Note: Not in any common header. */
 
-void
-mld6_init(void)
+SYSCTL_NODE(_net_inet6, OID_AUTO, mld, CTLFLAG_RW, 0,
+    "IPv6 Multicast Listener Discovery");
+
+/*
+ * Virtualized sysctls.
+ */
+SYSCTL_V_PROC(V_NET, vnet_inet6, _net_inet6_mld, OID_AUTO, gsrdelay,
+    CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, mld_gsrdelay.tv_sec, 0,
+    sysctl_mld_gsr, "I",
+    "Rate limit for MLDv2 Group-and-Source queries in seconds");
+
+/*
+ * Non-virtualized sysctls.
+ */
+SYSCTL_NODE(_net_inet6_mld, OID_AUTO, ifinfo, CTLFLAG_RD | CTLFLAG_MPSAFE,
+    sysctl_mld_ifinfo, "Per-interface MLDv2 state");
+
+/*
+ * Packed Router Alert option structure declaration.
+ */
+struct mld_raopt {
+	struct ip6_hbh		hbh;
+	struct ip6_opt		pad;
+	struct ip6_opt_router	ra;
+} __packed;
+
+/*
+ * Router Alert hop-by-hop option header.
+ */
+static struct mld_raopt mld_ra = {
+	.hbh = { 0, 0 },
+	.pad = { .ip6o_type = IP6OPT_PADN, 0 },
+	.ra = {
+	    .ip6or_type = IP6OPT_ROUTER_ALERT,
+	    .ip6or_len = IP6OPT_RTALERT_LEN - 2,
+	    .ip6or_value[0] = ((IP6OPT_RTALERT_MLD >> 8) & 0xFF),
+	    .ip6or_value[1] = (IP6OPT_RTALERT_MLD & 0xFF)
+	}
+};
+static struct ip6_pktopts mld_po;
+
+static __inline void
+mld_save_context(struct mbuf *m, struct ifnet *ifp)
+{
+
+#ifdef VIMAGE
+	m->m_pkthdr.header = ifp->if_vnet;
+#endif /* VIMAGE */
+	m->m_pkthdr.flowid = ifp->if_index;
+}
+
+static __inline void
+mld_scrub_context(struct mbuf *m)
+{
+
+	m->m_pkthdr.header = NULL;
+	m->m_pkthdr.flowid = 0;
+}
+
+/*
+ * Restore context from a queued output chain.
+ * Return saved ifindex.
+ *
+ * VIMAGE: The assertion is there to make sure that we
+ * actually called CURVNET_SET() with what's in the mbuf chain.
+ */
+static __inline uint32_t
+mld_restore_context(struct mbuf *m)
+{
+
+#ifdef notyet
+#if defined(VIMAGE) && defined(INVARIANTS)
+	KASSERT(curvnet == (m->m_pkthdr.header),
+	    ("%s: called when curvnet was not restored", __func__));
+#endif
+#endif
+	return (m->m_pkthdr.flowid);
+}
+
+/*
+ * Retrieve or set threshold between group-source queries in seconds.
+ *
+ * VIMAGE: Assume curvnet set by caller.
+ * SMPng: NOTE: Serialized by MLD lock.
+ */
+static int
+sysctl_mld_gsr(SYSCTL_HANDLER_ARGS)
 {
 	INIT_VNET_INET6(curvnet);
-	static u_int8_t hbh_buf[8];
-	struct ip6_hbh *hbh = (struct ip6_hbh *)hbh_buf;
-	u_int16_t rtalert_code = htons((u_int16_t)IP6OPT_RTALERT_MLD);
+	int error;
+	int i;
+
+	error = sysctl_wire_old_buffer(req, sizeof(int));
+	if (error)
+		return (error);
 
-	/* ip6h_nxt will be fill in later */
-	hbh->ip6h_len = 0;	/* (8 >> 3) - 1 */
+	MLD_LOCK();
 
-	/* XXX: grotty hard coding... */
-	hbh_buf[2] = IP6OPT_PADN;	/* 2 byte padding */
-	hbh_buf[3] = 0;
-	hbh_buf[4] = IP6OPT_ROUTER_ALERT;
-	hbh_buf[5] = IP6OPT_RTALERT_LEN - 2;
-	bcopy((caddr_t)&rtalert_code, &hbh_buf[6], sizeof(u_int16_t));
+	i = V_mld_gsrdelay.tv_sec;
 
-	ip6_initpktopts(&V_ip6_opts);
-	V_ip6_opts.ip6po_hbh = hbh;
+	error = sysctl_handle_int(oidp, &i, 0, req);
+	if (error || !req->newptr)
+		goto out_locked;
+
+	if (i < -1 || i >= 60) {
+		error = EINVAL;
+		goto out_locked;
+	}
+
+	CTR2(KTR_MLD, "change mld_gsrdelay from %d to %d",
+	     V_mld_gsrdelay.tv_sec, i);
+	V_mld_gsrdelay.tv_sec = i;
+
+out_locked:
+	MLD_UNLOCK();
+	return (error);
 }
 
-static void
-mld_starttimer(struct in6_multi *in6m)
+/*
+ * Expose struct mld_ifinfo to userland, keyed by ifindex.
+ * For use by ifmcstat(8).
+ *
+ * SMPng: NOTE: Does an unlocked ifindex space read.
+ * VIMAGE: Assume curvnet set by caller. The node handler itself
+ * is not directly virtualized.
+ */
+static int
+sysctl_mld_ifinfo(SYSCTL_HANDLER_ARGS)
 {
-	struct timeval now;
+	INIT_VNET_NET(curvnet);
+	INIT_VNET_INET6(curvnet);
+	int			*name;
+	int			 error;
+	u_int			 namelen;
+	struct ifnet		*ifp;
+	struct mld_ifinfo	*mli;
+
+	name = (int *)arg1;
+	namelen = arg2;
+
+	if (req->newptr != NULL)
+		return (EPERM);
 
-	microtime(&now);
-	in6m->in6m_timer_expire.tv_sec = now.tv_sec + in6m->in6m_timer / hz;
-	in6m->in6m_timer_expire.tv_usec = now.tv_usec +
-	    (in6m->in6m_timer % hz) * (1000000 / hz);
-	if (in6m->in6m_timer_expire.tv_usec > 1000000) {
-		in6m->in6m_timer_expire.tv_sec++;
-		in6m->in6m_timer_expire.tv_usec -= 1000000;
+	if (namelen != 1)
+		return (EINVAL);
+
+	error = sysctl_wire_old_buffer(req, sizeof(struct mld_ifinfo));
+	if (error)
+		return (error);
+
+	IN6_MULTI_LOCK();
+	MLD_LOCK();
+
+	if (name[0] <= 0 || name[0] > V_if_index) {
+		error = ENOENT;
+		goto out_locked;
 	}
 
-	/* start or restart the timer */
-	callout_reset(in6m->in6m_timer_ch, in6m->in6m_timer,
-	    (void (*)(void *))mld_timeo, in6m);
+	error = ENOENT;
+
+	ifp = ifnet_byindex(name[0]);
+	if (ifp == NULL)
+		goto out_locked;
+
+	LIST_FOREACH(mli, &V_mli_head, mli_link) {
+		if (ifp == mli->mli_ifp) {
+			error = SYSCTL_OUT(req, mli,
+			    sizeof(struct mld_ifinfo));
+			break;
+		}
+	}
+
+out_locked:
+	MLD_UNLOCK();
+	IN6_MULTI_UNLOCK();
+	return (error);
 }
 
+/*
+ * Dispatch an entire queue of pending packet chains.
+ * VIMAGE: Assumes the vnet pointer has been set.
+ */
 static void
-mld_stoptimer(struct in6_multi *in6m)
+mld_dispatch_queue(struct ifqueue *ifq, int limit)
 {
-	if (in6m->in6m_timer == IN6M_TIMER_UNDEF)
-		return;
+	struct mbuf *m;
 
-	callout_stop(in6m->in6m_timer_ch);
-	in6m->in6m_timer = IN6M_TIMER_UNDEF;
+	for (;;) {
+		_IF_DEQUEUE(ifq, m);
+		if (m == NULL)
+			break;
+		CTR3(KTR_MLD, "%s: dispatch %p from %p", __func__, ifq, m);
+		mld_dispatch_packet(m);
+		if (--limit == 0)
+			break;
+	}
 }
 
-static void
-mld_timeo(struct in6_multi *in6m)
+/*
+ * Filter outgoing MLD report state by group.
+ *
+ * Reports are ALWAYS suppressed for ALL-HOSTS (ff02::1)
+ * and node-local addresses. However, kernel and socket consumers
+ * always embed the KAME scope ID in the address provided, so strip it
+ * when performing comparison.
+ * Note: This is not the same as the *multicast* scope.
+ *
+ * Return zero if the given group is one for which MLD reports
+ * should be suppressed, or non-zero if reports should be issued.
+ */
+static __inline int
+mld_is_addr_reported(const struct in6_addr *addr)
 {
-	int s = splnet();
+	INIT_VNET_INET6(curvnet);
 
-	in6m->in6m_timer = IN6M_TIMER_UNDEF;
+	KASSERT(IN6_IS_ADDR_MULTICAST(addr), ("%s: not multicast", __func__));
 
-	callout_stop(in6m->in6m_timer_ch);
+	if (IPV6_ADDR_MC_SCOPE(addr) == IPV6_ADDR_SCOPE_NODELOCAL)
+		return (0);
 
-	switch (in6m->in6m_state) {
-	case MLD_REPORTPENDING:
-		mld6_start_listening(in6m);
-		break;
-	default:
-		mld6_sendpkt(in6m, MLD_LISTENER_REPORT, NULL);
-		break;
+	if (IPV6_ADDR_MC_SCOPE(addr) == IPV6_ADDR_SCOPE_LINKLOCAL) {
+		struct in6_addr tmp = *addr;
+		in6_clearscope(&tmp);
+		if (IN6_ARE_ADDR_EQUAL(&tmp, &in6addr_linklocal_allnodes))
+			return (0);
 	}
 
-	splx(s);
+	return (1);
 }
 
-static u_long
-mld_timerresid(struct in6_multi *in6m)
+/*
+ * Attach MLD when PF_INET6 is attached to an interface.
+ *
+ * SMPng: Normally called with IF_AFDATA_LOCK held.
+ * VIMAGE: Currently we set the vnet pointer, although it is
+ * likely that it was already set by our caller.
+ */
+struct mld_ifinfo *
+mld_domifattach(struct ifnet *ifp)
 {
-	struct timeval now, diff;
+	struct mld_ifinfo *mli;
 
-	microtime(&now);
+	CTR3(KTR_MLD, "%s: called for ifp %p(%s)",
+	    __func__, ifp, ifp->if_xname);
 
-	if (now.tv_sec > in6m->in6m_timer_expire.tv_sec ||
-	    (now.tv_sec == in6m->in6m_timer_expire.tv_sec &&
-	    now.tv_usec > in6m->in6m_timer_expire.tv_usec)) {
-		return (0);
-	}
-	diff = in6m->in6m_timer_expire;
-	diff.tv_sec -= now.tv_sec;
-	diff.tv_usec -= now.tv_usec;
-	if (diff.tv_usec < 0) {
-		diff.tv_sec--;
-		diff.tv_usec += 1000000;
-	}
+	CURVNET_SET(ifp->if_vnet);
+	MLD_LOCK();
+
+	mli = mli_alloc_locked(ifp);
+	if (!(ifp->if_flags & IFF_MULTICAST))
+		mli->mli_flags |= MLIF_SILENT;
+
+	MLD_UNLOCK();
+	CURVNET_RESTORE();
 
-	/* return the remaining time in milliseconds */
-	return (diff.tv_sec * 1000 + diff.tv_usec / 1000);
+	return (mli);
 }
 
-void
-mld6_start_listening(struct in6_multi *in6m)
+/*
+ * VIMAGE: assume curvnet set by caller.
+ */
+static struct mld_ifinfo *
+mli_alloc_locked(/*const*/ struct ifnet *ifp)
 {
-	struct in6_addr all_in6;
-	int s = splnet();
+	INIT_VNET_INET6(ifp->if_vnet);
+	struct mld_ifinfo *mli;
+
+	MLD_LOCK_ASSERT();
+
+	mli = malloc(sizeof(struct mld_ifinfo), M_MLD, M_NOWAIT|M_ZERO);
+	if (mli == NULL)
+		goto out;
+
+	mli->mli_ifp = ifp;
+	mli->mli_version = MLD_VERSION_2;
+	mli->mli_flags = 0;
+	mli->mli_rv = MLD_RV_INIT;
+	mli->mli_qi = MLD_QI_INIT;
+	mli->mli_qri = MLD_QRI_INIT;
+	mli->mli_uri = MLD_URI_INIT;
+
+	SLIST_INIT(&mli->mli_relinmhead);
 
 	/*
-	 * RFC2710 page 10:
-	 * The node never sends a Report or Done for the link-scope all-nodes
-	 * address.
-	 * MLD messages are never sent for multicast addresses whose scope is 0
-	 * (reserved) or 1 (node-local).
+	 * Responses to general queries are subject to bounds.
 	 */
-	all_in6 = in6addr_linklocal_allnodes;
-	if (in6_setscope(&all_in6, in6m->in6m_ifp, NULL)) {
-		/* XXX: this should not happen! */
-		in6m->in6m_timer = 0;
-		in6m->in6m_state = MLD_OTHERLISTENER;
-	}
-	if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &all_in6) ||
-	    IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) <
-	    IPV6_ADDR_SCOPE_LINKLOCAL) {
-		in6m->in6m_timer = 0;
-		in6m->in6m_state = MLD_OTHERLISTENER;
-	} else {
-		mld6_sendpkt(in6m, MLD_LISTENER_REPORT, NULL);
-		in6m->in6m_timer = arc4random() %
-			MLD_UNSOLICITED_REPORT_INTERVAL * hz;
-		in6m->in6m_state = MLD_IREPORTEDLAST;
+	IFQ_SET_MAXLEN(&mli->mli_gq, MLD_MAX_RESPONSE_PACKETS);
+
+	LIST_INSERT_HEAD(&V_mli_head, mli, mli_link);
+
+	CTR2(KTR_MLD, "allocate mld_ifinfo for ifp %p(%s)",
+	     ifp, ifp->if_xname);
+
+out:
+	return (mli);
+}
+
+/*
+ * Hook for ifdetach.
+ *
+ * NOTE: Some finalization tasks need to run before the protocol domain
+ * is detached, but also before the link layer does its cleanup.
+ * Run before link-layer cleanup; cleanup groups, but do not free MLD state.
+ *
+ * SMPng: Caller must hold IN6_MULTI_LOCK().
+ * Must take IF_ADDR_LOCK() to cover if_multiaddrs iterator.
+ * XXX This routine is also bitten by unlocked ifma_protospec access.
+ *
+ * VIMAGE: curvnet should have been set by caller, but let's not assume
+ * that for now.
+ */
+void
+mld_ifdetach(struct ifnet *ifp)
+{
+	struct mld_ifinfo	*mli;
+	struct ifmultiaddr	*ifma;
+	struct in6_multi	*inm, *tinm;
+
+	CTR3(KTR_MLD, "%s: called for ifp %p(%s)", __func__, ifp,
+	    ifp->if_xname);
+
+	CURVNET_SET(ifp->if_vnet);
 
-		mld_starttimer(in6m);
+	IN6_MULTI_LOCK_ASSERT();
+	MLD_LOCK();
+
+	mli = MLD_IFINFO(ifp);
+	if (mli->mli_version == MLD_VERSION_2) {
+		IF_ADDR_LOCK(ifp);
+		TAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
+			if (ifma->ifma_addr->sa_family != AF_INET6 ||
+			    ifma->ifma_protospec == NULL)
+				continue;
+			inm = (struct in6_multi *)ifma->ifma_protospec;
+			if (inm->in6m_state == MLD_LEAVING_MEMBER) {
+				SLIST_INSERT_HEAD(&mli->mli_relinmhead,
+				    inm, in6m_nrele);
+			}
+			in6m_clear_recorded(inm);
+		}
+		IF_ADDR_UNLOCK(ifp);
+		SLIST_FOREACH_SAFE(inm, &mli->mli_relinmhead, in6m_nrele,
+		    tinm) {
+			SLIST_REMOVE_HEAD(&mli->mli_relinmhead, in6m_nrele);
+			in6m_release_locked(inm);
+		}
 	}
-	splx(s);
+
+	MLD_UNLOCK();
+	CURVNET_RESTORE();
 }
 
+/*
+ * Hook for domifdetach.
+ * Runs after link-layer cleanup; free MLD state.
+ *
+ * SMPng: Normally called with IF_AFDATA_LOCK held.
+ * VIMAGE: curvnet should have been set by caller, but let's not assume
+ * that for now.
+ */
 void
-mld6_stop_listening(struct in6_multi *in6m)
+mld_domifdetach(struct ifnet *ifp)
 {
-	struct in6_addr allnode, allrouter;
 
-	allnode = in6addr_linklocal_allnodes;
-	if (in6_setscope(&allnode, in6m->in6m_ifp, NULL)) {
-		/* XXX: this should not happen! */
-		return;
+	CTR3(KTR_MLD, "%s: called for ifp %p(%s)",
+	    __func__, ifp, ifp->if_xname);
+
+	CURVNET_SET(ifp->if_vnet);
+
+	MLD_LOCK();
+	mli_delete_locked(ifp);
+	MLD_UNLOCK();
+
+	CURVNET_RESTORE();
+}
+
+static void
+mli_delete_locked(const struct ifnet *ifp)
+{
+	INIT_VNET_INET6(ifp->if_vnet);
+	struct mld_ifinfo *mli, *tmli;
+
+	CTR3(KTR_MLD, "%s: freeing mld_ifinfo for ifp %p(%s)",
+	    __func__, ifp, ifp->if_xname);
+
+	MLD_LOCK_ASSERT();
+
+	LIST_FOREACH_SAFE(mli, &V_mli_head, mli_link, tmli) {
+		if (mli->mli_ifp == ifp) {
+			/*
+			 * Free deferred General Query responses.
+			 */
+			_IF_DRAIN(&mli->mli_gq);
+
+			LIST_REMOVE(mli, mli_link);
+
+			KASSERT(SLIST_EMPTY(&mli->mli_relinmhead),
+			    ("%s: there are dangling in_multi references",
+			    __func__));
+
+			free(mli, M_MLD);
+			return;
+		}
 	}
-	allrouter = in6addr_linklocal_allrouters;
-	if (in6_setscope(&allrouter, in6m->in6m_ifp, NULL)) {
-		/* XXX impossible */
-		return;
+#ifdef INVARIANTS
+	panic("%s: mld_ifinfo not found for ifp %p\n", __func__,  ifp);
+#endif
+}
+
+/*
+ * Process a received MLDv1 general or address-specific query.
+ * Assumes that the query header has been pulled up to sizeof(mld_hdr).
+ */
+static int
+mld_v1_input_query(struct ifnet *ifp, const struct ip6_hdr *ip6,
+    const struct mld_hdr *mld)
+{
+	INIT_VNET_INET6(ifp->if_vnet);
+	struct ifmultiaddr	*ifma;
+	struct mld_ifinfo	*mli;
+	struct in6_multi	*inm;
+	uint16_t		 timer;
+#ifdef KTR
+	char			 ip6tbuf[INET6_ADDRSTRLEN];
+#endif
+
+	IN6_MULTI_LOCK();
+	IF_ADDR_LOCK(ifp);
+	MLD_LOCK();
+
+	mli = MLD_IFINFO(ifp);
+	KASSERT(mli != NULL, ("%s: no mld_ifinfo for ifp %p", __func__, ifp));
+
+	/*
+	 * Switch to MLDv1 host compatibility mode.
+	 */
+	mld_set_version(mli, MLD_VERSION_1);
+
+	timer = ntohs(mld->mld_maxdelay) * PR_FASTHZ / MLD_TIMER_SCALE;
+	if (timer == 0)
+		timer = 1;
+
+	if (!IN6_IS_ADDR_UNSPECIFIED(&mld->mld_addr)) {
+		/*
+		 * MLDv1 Group-Specific Query.
+		 * If this is a group-specific MLDv1 query, we need only
+		 * look up the single group to process it.
+		 */
+		inm = in6m_lookup_locked(ifp, &mld->mld_addr);
+		if (inm != NULL) {
+			CTR3(KTR_MLD, "process v1 query %s on ifp %p(%s)",
+			    ip6_sprintf(ip6tbuf, &mld->mld_addr),
+			    ifp, ifp->if_xname);
+			mld_v1_update_group(inm, timer);
+		}
+	} else {
+		/*
+		 * MLDv1 General Query.
+		 * If this was not sent to the all-nodes group, ignore it.
+		 *
+		 * XXX Do we need to check for a scope ID in the destination
+		 * address on input and strip it?
+		 */
+		if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst,
+		    &in6addr_linklocal_allnodes)) {
+			/*
+			 * For each reporting group joined on this
+			 * interface, kick the report timer.
+			 */
+			CTR2(KTR_MLD,
+			    "process v1 general query on ifp %p(%s)",
+			    ifp, ifp->if_xname);
+
+			TAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
+				if (ifma->ifma_addr->sa_family != AF_INET6 ||
+				    ifma->ifma_protospec == NULL)
+					continue;
+				inm = (struct in6_multi *)ifma->ifma_protospec;
+				mld_v1_update_group(inm, timer);
+			}
+		}
 	}
-	if (in6m->in6m_state == MLD_IREPORTEDLAST &&
-	    !IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &allnode) &&
-	    IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) >
-	    IPV6_ADDR_SCOPE_INTFACELOCAL) {
-		mld6_sendpkt(in6m, MLD_LISTENER_DONE, &allrouter);
+
+	MLD_UNLOCK();
+	IF_ADDR_UNLOCK(ifp);
+	IN6_MULTI_UNLOCK();
+
+	return (0);
+}
+
+/*
+ * Update the report timer on a group in response to an MLDv1 query.
+ *
+ * If we are becoming the reporting member for this group, start the timer.
+ * If we already are the reporting member for this group, and timer is
+ * below the threshold, reset it.
+ *
+ * We may be updating the group for the first time since we switched
+ * to MLDv2. If we are, then we must clear any recorded source lists,
+ * and transition to REPORTING state; the group timer is overloaded
+ * for group and group-source query responses. 
+ *
+ * Unlike MLDv2, the delay per group should be jittered
+ * to avoid bursts of MLDv1 reports.
+ */
+static void
+mld_v1_update_group(struct in6_multi *inm, const int timer)
+{
+	INIT_VNET_INET6(curvnet);
+#ifdef KTR
+	char			 ip6tbuf[INET6_ADDRSTRLEN];
+#endif
+
+	CTR4(KTR_MLD, "%s: %s/%s timer=%d", __func__,
+	    ip6_sprintf(ip6tbuf, &inm->in6m_addr),
+	    inm->in6m_ifp->if_xname, timer);
+
+	IN6_MULTI_LOCK_ASSERT();
+
+	switch (inm->in6m_state) {
+	case MLD_NOT_MEMBER:
+	case MLD_SILENT_MEMBER:
+		break;
+	case MLD_REPORTING_MEMBER:
+		if (inm->in6m_timer != 0 &&
+		    inm->in6m_timer <= timer) {
+			CTR1(KTR_MLD, "%s: REPORTING and timer running, "
+			    "skipping.", __func__);
+			break;
+		}
+		/* FALLTHROUGH */
+	case MLD_SG_QUERY_PENDING_MEMBER:
+	case MLD_G_QUERY_PENDING_MEMBER:
+	case MLD_IDLE_MEMBER:
+	case MLD_LAZY_MEMBER:
+	case MLD_AWAKENING_MEMBER:
+		CTR1(KTR_MLD, "%s: ->REPORTING", __func__);
+		inm->in6m_state = MLD_REPORTING_MEMBER;
+		inm->in6m_timer = MLD_RANDOM_DELAY(timer);
+		V_current_state_timers_running6 = 1;
+		break;
+	case MLD_SLEEPING_MEMBER:
+		CTR1(KTR_MLD, "%s: ->AWAKENING", __func__);
+		inm->in6m_state = MLD_AWAKENING_MEMBER;
+		break;
+	case MLD_LEAVING_MEMBER:
+		break;
 	}
 }
 
-void
-mld6_input(struct mbuf *m, int off)
+/*
+ * Process a received MLDv2 general, group-specific or
+ * group-and-source-specific query.
+ *
+ * Assumes that the query header has been pulled up to sizeof(mldv2_query).
+ *
+ * Return 0 if successful, otherwise an appropriate error code is returned.
+ */
+static int
+mld_v2_input_query(struct ifnet *ifp, const struct ip6_hdr *ip6,
+    struct mbuf *m, const int off, const int icmp6len)
 {
 	INIT_VNET_INET6(curvnet);
-	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
-	struct mld_hdr *mldh;
-	struct ifnet *ifp = m->m_pkthdr.rcvif;
-	struct in6_multi *in6m;
-	struct in6_addr mld_addr, all_in6;
-	struct in6_ifaddr *ia;
-	struct ifmultiaddr *ifma;
-	u_long timer;		/* timer value in the MLD query header */
-
-#ifndef PULLDOWN_TEST
-	IP6_EXTHDR_CHECK(m, off, sizeof(*mldh),);
-	mldh = (struct mld_hdr *)(mtod(m, caddr_t) + off);
-#else
-	IP6_EXTHDR_GET(mldh, struct mld_hdr *, m, off, sizeof(*mldh));
-	if (mldh == NULL) {
-		ICMP6STAT_INC(icp6s_tooshort);
-		return;
+	struct mld_ifinfo	*mli;
+	struct mldv2_query	*mld;
+	struct in6_multi	*inm;
+	uint32_t		 maxdelay, nsrc, qqi;
+	uint16_t		 timer;
+	uint8_t			 qrv;
+
+	CTR2(KTR_MLD, "process v2 query on ifp %p(%s)", ifp, ifp->if_xname);
+
+	mld = (struct mldv2_query *)(mtod(m, uint8_t *) + off);
+
+	maxdelay = ntohs(mld->mld_maxdelay);	/* in 1/10ths of a second */
+	if (maxdelay >= 32678) {
+		maxdelay = (MLD_MRC_MANT(mld->mld_maxdelay) | 0x1000) <<
+			   (MLD_MRC_EXP(mld->mld_maxdelay) + 3);
 	}
-#endif
 
-	/* source address validation */
-	ip6 = mtod(m, struct ip6_hdr *); /* in case mpullup */
-	if (!IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) {
-		char ip6bufs[INET6_ADDRSTRLEN], ip6bufg[INET6_ADDRSTRLEN];
-		log(LOG_ERR,
-		    "mld6_input: src %s is not link-local (grp=%s)\n",
-		    ip6_sprintf(ip6bufs, &ip6->ip6_src),
-		    ip6_sprintf(ip6bufg, &mldh->mld_addr));
+	qrv = MLD_QRV(mld->mld_misc);
+	if (qrv < 2) {
+		CTR3(KTR_MLD, "%s: clamping qrv %d to %d", __func__,
+		    qrv, MLD_RV_INIT);
+		qrv = MLD_RV_INIT;
+	}
+
+	qqi = mld->mld_qqi;
+	if (qqi >= 128) {
+		qqi = MLD_QQIC_MANT(mld->mld_qqi) <<
+		     (MLD_QQIC_EXP(mld->mld_qqi) + 3);
+	}
+
+	timer = maxdelay * PR_FASTHZ / MLD_TIMER_SCALE;
+	if (timer == 0)
+		timer = 1;
+
+	nsrc = ntohs(mld->mld_numsrc);
+	if (nsrc > MLD_MAX_GS_SOURCES)
+		return (EMSGSIZE);
+	if (icmp6len < sizeof(struct mldv2_query) +
+	    (nsrc * sizeof(struct in6_addr)))
+		return (EMSGSIZE);
+
+	IN6_MULTI_LOCK();
+	IF_ADDR_LOCK(ifp);
+	MLD_LOCK();
+
+	mli = MLD_IFINFO(ifp);
+	KASSERT(mli != NULL, ("%s: no mld_ifinfo for ifp %p", __func__, ifp));
+
+	mld_set_version(mli, MLD_VERSION_2);
+
+	mli->mli_rv = qrv;
+	mli->mli_qi = qqi;
+	mli->mli_qri = maxdelay;
+
+	CTR4(KTR_MLD, "%s: qrv %d qi %d qri %d", __func__, qrv, qqi,
+	    maxdelay);
+
+	if (IN6_IS_ADDR_UNSPECIFIED(&mld->mld_addr)) {
 		/*
-		 * spec (RFC2710) does not explicitly
-		 * specify to discard the packet from a non link-local
-		 * source address. But we believe it's expected to do so.
-		 * XXX: do we have to allow :: as source?
+		 * MLDv2 General Query.
+		 * Schedule a current-state report on this ifp for
+		 * all groups, possibly containing source lists.
 		 */
-		m_freem(m);
-		return;
+		if (!IN6_ARE_ADDR_EQUAL(&in6addr_linklocal_allnodes,
+		    &ip6->ip6_dst) || nsrc > 0) {
+			/*
+			 * General Queries SHOULD be directed to ff02::1.
+			 * A general query with a source list has undefined
+			 * behaviour; discard it.
+			 */
+			goto out_locked;
+		}
+
+		CTR2(KTR_MLD, "process v2 general query on ifp %p(%s)",
+		    ifp, ifp->if_xname);
+
+		/*
+		 * If there is a pending General Query response
+		 * scheduled earlier than the selected delay, do
+		 * not schedule any other reports.
+		 * Otherwise, reset the interface timer.
+		 */
+		if (mli->mli_v1_timer == 0 || mli->mli_v2_timer >= timer) {
+			mli->mli_v1_timer = MLD_RANDOM_DELAY(timer);
+			V_interface_timers_running6 = 1;
+		}
+	} else {
+		/*
+		 * MLDv2 Group-specific or Group-and-source-specific Query.
+		 *
+		 * Group-source-specific queries are throttled on
+		 * a per-group basis to defeat denial-of-service attempts.
+		 * Queries for groups we are not a member of on this
+		 * link are simply ignored.
+		 */
+		inm = in6m_lookup_locked(ifp, &mld->mld_addr);
+		if (inm == NULL)
+			goto out_locked;
+		if (nsrc > 0) {
+			if (!ratecheck(&inm->in6m_lastgsrtv,
+			    &V_mld_gsrdelay)) {
+				CTR1(KTR_MLD, "%s: GS query throttled.",
+				    __func__);
+				goto out_locked;
+			}
+		}
+		CTR2(KTR_MLD, "process v2 group query on ifp %p(%s)",
+		     ifp, ifp->if_xname);
+		/*
+		 * If there is a pending General Query response
+		 * scheduled sooner than the selected delay, no
+		 * further report need be scheduled.
+		 * Otherwise, prepare to respond to the
+		 * group-specific or group-and-source query.
+		 */
+		if (mli->mli_v1_timer == 0 || mli->mli_v2_timer >= timer)
+			mld_v2_process_group_query(inm, mli, timer, m, off);
+	}
+
+out_locked:
+	MLD_UNLOCK();
+	IF_ADDR_UNLOCK(ifp);
+	IN6_MULTI_UNLOCK();
+
+	return (0);
+}
+
+/*
+ * Process a recieved MLDv2 group-specific or group-and-source-specific
+ * query.
+ * Return <0 if any error occured. Currently this is ignored.
+ */
+static int
+mld_v2_process_group_query(struct in6_multi *inm, struct mld_ifinfo *mli,
+    int timer, struct mbuf *m0, const int off)
+{
+	INIT_VNET_INET6(curvnet);
+	struct mldv2_query	*mld;
+	int			 retval;
+	uint16_t		 nsrc;
+
+	IN6_MULTI_LOCK_ASSERT();
+	MLD_LOCK_ASSERT();
+
+	retval = 0;
+	mld = (struct mldv2_query *)(mtod(m0, uint8_t *) + off);
+
+	switch (inm->in6m_state) {
+	case MLD_NOT_MEMBER:
+	case MLD_SILENT_MEMBER:
+	case MLD_SLEEPING_MEMBER:
+	case MLD_LAZY_MEMBER:
+	case MLD_AWAKENING_MEMBER:
+	case MLD_IDLE_MEMBER:
+	case MLD_LEAVING_MEMBER:
+		return (retval);
+		break;
+	case MLD_REPORTING_MEMBER:
+	case MLD_G_QUERY_PENDING_MEMBER:
+	case MLD_SG_QUERY_PENDING_MEMBER:
+		break;
 	}
 
+	nsrc = ntohs(mld->mld_numsrc);
+
 	/*
-	 * make a copy for local work (in6_setscope() may modify the 1st arg)
+	 * Deal with group-specific queries upfront.
+	 * If any group query is already pending, purge any recorded
+	 * source-list state if it exists, and schedule a query response
+	 * for this group-specific query.
 	 */
-	mld_addr = mldh->mld_addr;
-	if (in6_setscope(&mld_addr, ifp, NULL)) {
-		/* XXX: this should not happen! */
-		m_free(m);
-		return;
+	if (nsrc == 0) {
+		if (inm->in6m_state == MLD_G_QUERY_PENDING_MEMBER ||
+		    inm->in6m_state == MLD_SG_QUERY_PENDING_MEMBER) {
+			in6m_clear_recorded(inm);
+			timer = min(inm->in6m_timer, timer);
+		}
+		inm->in6m_state = MLD_G_QUERY_PENDING_MEMBER;
+		inm->in6m_timer = MLD_RANDOM_DELAY(timer);
+		V_current_state_timers_running6 = 1;
+		return (retval);
 	}
 
 	/*
-	 * In the MLD6 specification, there are 3 states and a flag.
-	 *
-	 * In Non-Listener state, we simply don't have a membership record.
-	 * In Delaying Listener state, our timer is running (in6m->in6m_timer)
-	 * In Idle Listener state, our timer is not running
-	 * (in6m->in6m_timer==IN6M_TIMER_UNDEF)
-	 *
-	 * The flag is in6m->in6m_state, it is set to MLD_OTHERLISTENER if
-	 * we have heard a report from another member, or MLD_IREPORTEDLAST
-	 * if we sent the last report.
+	 * Deal with the case where a group-and-source-specific query has
+	 * been received but a group-specific query is already pending.
 	 */
-	switch(mldh->mld_type) {
-	case MLD_LISTENER_QUERY:
-		if (ifp->if_flags & IFF_LOOPBACK)
-			break;
-
-		if (!IN6_IS_ADDR_UNSPECIFIED(&mld_addr) &&
-		    !IN6_IS_ADDR_MULTICAST(&mld_addr))
-			break;	/* print error or log stat? */
+	if (inm->in6m_state == MLD_G_QUERY_PENDING_MEMBER) {
+		timer = min(inm->in6m_timer, timer);
+		inm->in6m_timer = MLD_RANDOM_DELAY(timer);
+		V_current_state_timers_running6 = 1;
+		return (retval);
+	}
 
-		all_in6 = in6addr_linklocal_allnodes;
-		if (in6_setscope(&all_in6, ifp, NULL)) {
-			/* XXX: this should not happen! */
-			break;
+	/*
+	 * Finally, deal with the case where a group-and-source-specific
+	 * query has been received, where a response to a previous g-s-r
+	 * query exists, or none exists.
+	 * In this case, we need to parse the source-list which the Querier
+	 * has provided us with and check if we have any source list filter
+	 * entries at T1 for these sources. If we do not, there is no need
+	 * schedule a report and the query may be dropped.
+	 * If we do, we must record them and schedule a current-state
+	 * report for those sources.
+	 */
+	if (inm->in6m_nsrc > 0) {
+		struct mbuf		*m;
+		uint8_t			*sp;
+		int			 i, nrecorded;
+		int			 soff;
+
+		m = m0;
+		soff = off + sizeof(struct mldv2_query);
+		nrecorded = 0;
+		for (i = 0; i < nsrc; i++) {
+			sp = mtod(m, uint8_t *) + soff;
+			retval = in6m_record_source(inm,
+			    (const struct in6_addr *)sp);
+			if (retval < 0)
+				break;
+			nrecorded += retval;
+			soff += sizeof(struct in6_addr);
+			if (soff >= m->m_len) {
+				soff = soff - m->m_len;
+				m = m->m_next;
+				if (m == NULL)
+					break;
+			}
+		}
+		if (nrecorded > 0) {
+			CTR1(KTR_MLD,
+			    "%s: schedule response to SG query", __func__);
+			inm->in6m_state = MLD_SG_QUERY_PENDING_MEMBER;
+			inm->in6m_timer = MLD_RANDOM_DELAY(timer);
+			V_current_state_timers_running6 = 1;
 		}
+	}
+
+	return (retval);
+}
+
+/*
+ * Process a received MLDv1 host membership report.
+ * Assumes mld points to mld_hdr in pulled up mbuf chain.
+ */
+static int
+mld_v1_input_report(struct ifnet *ifp, const struct ip6_hdr *ip6,
+    const struct mld_hdr *mld)
+{
+	INIT_VNET_INET6(curvnet);
+	struct in6_ifaddr	*ia;
+	struct in6_multi	*inm;
+#ifdef KTR
+	char			 ip6tbuf[INET6_ADDRSTRLEN];
+#endif
+
+	if (ifp->if_flags & IFF_LOOPBACK)
+		return (0);
+
+	if (!IN6_IS_ADDR_MULTICAST(&mld->mld_addr) ||
+	    !IN6_ARE_ADDR_EQUAL(&mld->mld_addr, &ip6->ip6_dst))
+		return (EINVAL);
+
+	/*
+	 * Make sure we don't hear our own membership report, as fast
+	 * leave requires knowing that we are the only member of a
+	 * group. Assume we used the link-local address if available,
+	 * otherwise look for ::.
+	 */
+	ia = in6ifa_ifpforlinklocal(ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST);
+	if ((ia && IN6_ARE_ADDR_EQUAL(&ip6->ip6_src, IA6_IN6(ia))) ||
+	    (ia == NULL && IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src)))
+		return (0);
+
+	CTR3(KTR_MLD, "process v1 report %s on ifp %p(%s)",
+	    ip6_sprintf(ip6tbuf, &mld->mld_addr), ifp, ifp->if_xname);
+
+	IN6_MULTI_LOCK();
+	IF_ADDR_LOCK(ifp);
+
+	/*
+	 * MLDv1 report suppression.
+	 * If we are a member of this group, and our membership should be
+	 * reported, and our group timer is pending or about to be reset,
+	 * stop our group timer by transitioning to the 'lazy' state.
+	 */
+	inm = in6m_lookup_locked(ifp, &mld->mld_addr);
+	if (inm != NULL) {
+		struct mld_ifinfo *mli;
+
+		mli = inm->in6m_mli;
+		KASSERT(mli != NULL,
+		    ("%s: no mli for ifp %p", __func__, ifp));
 
 		/*
-		 * - Start the timers in all of our membership records
-		 *   that the query applies to for the interface on
-		 *   which the query arrived excl. those that belong
-		 *   to the "all-nodes" group (ff02::1).
-		 * - Restart any timer that is already running but has
-		 *   A value longer than the requested timeout.
-		 * - Use the value specified in the query message as
-		 *   the maximum timeout.
+		 * If we are in MLDv2 host mode, do not allow the
+		 * other host's MLDv1 report to suppress our reports.
 		 */
-		timer = ntohs(mldh->mld_maxdelay);
+		if (mli->mli_version == MLD_VERSION_2)
+			goto out_locked;
 
-		IF_ADDR_LOCK(ifp);
-		IFP_TO_IA6(ifp, ia);
-		if (ia == NULL) {
-			IF_ADDR_UNLOCK(ifp);
+		inm->in6m_timer = 0;
+
+		switch (inm->in6m_state) {
+		case MLD_NOT_MEMBER:
+		case MLD_SILENT_MEMBER:
+		case MLD_SLEEPING_MEMBER:
+			break;
+		case MLD_REPORTING_MEMBER:
+		case MLD_IDLE_MEMBER:
+		case MLD_AWAKENING_MEMBER:
+			CTR3(KTR_MLD,
+			    "report suppressed for %s on ifp %p(%s)",
+			    ip6_sprintf(ip6tbuf, &mld->mld_addr),
+			    ifp, ifp->if_xname);
+		case MLD_LAZY_MEMBER:
+			inm->in6m_state = MLD_LAZY_MEMBER;
+			break;
+		case MLD_G_QUERY_PENDING_MEMBER:
+		case MLD_SG_QUERY_PENDING_MEMBER:
+		case MLD_LEAVING_MEMBER:
 			break;
 		}
+	}
 
-		/*
-		 * XXX: System timer resolution is too low to handle Max
-		 * Response Delay, so set 1 to the internal timer even if
-		 * the calculated value equals to zero when Max Response
-		 * Delay is positive.
-		 */
-		timer = ntohs(mldh->mld_maxdelay) * PR_FASTHZ / MLD_TIMER_SCALE;
-		if (timer == 0 && mldh->mld_maxdelay)
-			timer = 1;
+out_locked:
+	IF_ADDR_UNLOCK(ifp);
+	IN6_MULTI_UNLOCK();
 
-		TAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
-			if (ifma->ifma_addr->sa_family != AF_INET6)
-				continue;
-			in6m = (struct in6_multi *)ifma->ifma_protospec;
+	return (0);
+}
 
-			if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &all_in6) ||
-			    IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) <
-			    IPV6_ADDR_SCOPE_LINKLOCAL)
-				continue;
+/*
+ * MLD input path.
+ *
+ * Assume query messages which fit in a single ICMPv6 message header
+ * have been pulled up.
+ * Assume that userland will want to see the message, even if it
+ * otherwise fails kernel input validation; do not free it.
+ * Pullup may however free the mbuf chain m if it fails.
+ *
+ * Return IPPROTO_DONE if we freed m. Otherwise, return 0.
+ */
+int
+mld_input(struct mbuf *m, int off, int icmp6len)
+{
+	struct ifnet	*ifp;
+	struct ip6_hdr	*ip6;
+	struct mld_hdr	*mld;
+	int		 mldlen;
 
-			if (IN6_IS_ADDR_UNSPECIFIED(&mld_addr) ||
-			    IN6_ARE_ADDR_EQUAL(&mld_addr, &in6m->in6m_addr)) {
-				if (timer == 0) {
-					/* send a report immediately */
-					mld_stoptimer(in6m);
-					mld6_sendpkt(in6m, MLD_LISTENER_REPORT,
-						NULL);
-					in6m->in6m_timer = 0; /* reset timer */
-					in6m->in6m_state = MLD_IREPORTEDLAST;
-				}
-				else if (in6m->in6m_timer == IN6M_TIMER_UNDEF ||
-				    mld_timerresid(in6m) > timer) {
-					in6m->in6m_timer =
-					   1 + (arc4random() % timer) * hz / 1000;
-					mld_starttimer(in6m);
-				}
+	CTR3(KTR_MLD, "%s: called w/mbuf (%p,%d)", __func__, m, off);
+
+	ifp = m->m_pkthdr.rcvif;
+	INIT_VNET_INET6(ifp->if_vnet);
+
+	ip6 = mtod(m, struct ip6_hdr *);
+
+	/* Pullup to appropriate size. */
+	mld = (struct mld_hdr *)(mtod(m, uint8_t *) + off);
+	if (mld->mld_type == MLD_LISTENER_QUERY &&
+	    icmp6len >= sizeof(struct mldv2_query)) {
+		mldlen = sizeof(struct mldv2_query);
+	} else {
+		mldlen = sizeof(struct mld_hdr);
+	}
+	IP6_EXTHDR_GET(mld, struct mld_hdr *, m, off, mldlen);
+	if (mld == NULL) {
+		ICMP6STAT_INC(icp6s_badlen);
+		return (IPPROTO_DONE);
+	}
+
+	switch (mld->mld_type) {
+	case MLD_LISTENER_QUERY:
+		icmp6_ifstat_inc(ifp, ifs6_in_mldquery);
+		if (icmp6len == sizeof(struct mld_hdr)) {
+			if (mld_v1_input_query(ifp, ip6, mld) != 0)
+				return (0);
+		} else if (icmp6len >= sizeof(struct mldv2_query)) {
+			if (mld_v2_input_query(ifp, ip6, m, off,
+			    icmp6len) != 0)
+				return (0);
+		}
+		break;
+	case MLD_LISTENER_REPORT:
+		icmp6_ifstat_inc(ifp, ifs6_in_mldreport);
+		if (mld_v1_input_report(ifp, ip6, mld) != 0)
+			return (0);	/* Userland needs to see it. */
+		break;
+	case MLDV2_LISTENER_REPORT:
+		icmp6_ifstat_inc(ifp, ifs6_in_mldreport);
+		break;
+	case MLD_LISTENER_DONE:
+		icmp6_ifstat_inc(ifp, ifs6_in_mlddone);
+		break;
+	default:
+		break;
+	}
+
+	return (0);
+}
+
+/*
+ * Fast timeout handler (global).
+ * VIMAGE: Timeout handlers are expected to service all vimages.
+ */
+void
+mld_fasttimo(void)
+{
+	VNET_ITERATOR_DECL(vnet_iter);
+
+	VNET_LIST_RLOCK();
+	VNET_FOREACH(vnet_iter) {
+		CURVNET_SET(vnet_iter);
+		mld_fasttimo_vnet();
+		CURVNET_RESTORE();
+	}
+	VNET_LIST_RUNLOCK();
+}
+
+/*
+ * Fast timeout handler (per-vnet).
+ *
+ * VIMAGE: Assume caller has set up our curvnet.
+ */
+static void
+mld_fasttimo_vnet(void)
+{
+	INIT_VNET_INET6(curvnet);
+	struct ifqueue		 scq;	/* State-change packets */
+	struct ifqueue		 qrq;	/* Query response packets */
+	struct ifnet		*ifp;
+	struct mld_ifinfo	*mli;
+	struct ifmultiaddr	*ifma, *tifma;
+	struct in6_multi	*inm;
+	int			 uri_fasthz;
+
+	uri_fasthz = 0;
+
+	/*
+	 * Quick check to see if any work needs to be done, in order to
+	 * minimize the overhead of fasttimo processing.
+	 * SMPng: XXX Unlocked reads.
+	 */
+	if (!V_current_state_timers_running6 &&
+	    !V_interface_timers_running6 &&
+	    !V_state_change_timers_running6)
+		return;
+
+	IN6_MULTI_LOCK();
+	MLD_LOCK();
+
+	/*
+	 * MLDv2 General Query response timer processing.
+	 */
+	if (V_interface_timers_running6) {
+		CTR1(KTR_MLD, "%s: interface timers running", __func__);
+
+		V_interface_timers_running6 = 0;
+		LIST_FOREACH(mli, &V_mli_head, mli_link) {
+			if (mli->mli_v2_timer == 0) {
+				/* Do nothing. */
+			} else if (--mli->mli_v2_timer == 0) {
+				mld_v2_dispatch_general_query(mli);
+			} else {
+				V_interface_timers_running6 = 1;
+			}
+		}
+	}
+
+	if (!V_current_state_timers_running6 &&
+	    !V_state_change_timers_running6)
+		goto out_locked;
+
+	V_current_state_timers_running6 = 0;
+	V_state_change_timers_running6 = 0;
+
+	CTR1(KTR_MLD, "%s: state change timers running", __func__);
+
+	/*
+	 * MLD host report and state-change timer processing.
+	 * Note: Processing a v2 group timer may remove a node.
+	 */
+	LIST_FOREACH(mli, &V_mli_head, mli_link) {
+		ifp = mli->mli_ifp;
+
+		if (mli->mli_version == MLD_VERSION_2) {
+			uri_fasthz = MLD_RANDOM_DELAY(mli->mli_uri *
+			    PR_FASTHZ);
+
+			memset(&qrq, 0, sizeof(struct ifqueue));
+			IFQ_SET_MAXLEN(&qrq, MLD_MAX_G_GS_PACKETS);
+
+			memset(&scq, 0, sizeof(struct ifqueue));
+			IFQ_SET_MAXLEN(&scq, MLD_MAX_STATE_CHANGE_PACKETS);
+		}
+
+		IF_ADDR_LOCK(ifp);
+		TAILQ_FOREACH_SAFE(ifma, &ifp->if_multiaddrs, ifma_link,
+		    tifma) {
+			if (ifma->ifma_addr->sa_family != AF_INET6 ||
+			    ifma->ifma_protospec == NULL)
+				continue;
+			inm = (struct in6_multi *)ifma->ifma_protospec;
+			switch (mli->mli_version) {
+			case MLD_VERSION_1:
+				mld_v1_process_group_timer(inm,
+				    mli->mli_version);
+				break;
+			case MLD_VERSION_2:
+				mld_v2_process_group_timers(mli, &qrq,
+				    &scq, inm, uri_fasthz);
+				break;
 			}
 		}
 		IF_ADDR_UNLOCK(ifp);
+
+		if (mli->mli_version == MLD_VERSION_2) {
+			struct in6_multi		*tinm;
+
+			mld_dispatch_queue(&qrq, 0);
+			mld_dispatch_queue(&scq, 0);
+
+			/*
+			 * Free the in_multi reference(s) for
+			 * this lifecycle.
+			 */
+			SLIST_FOREACH_SAFE(inm, &mli->mli_relinmhead,
+			    in6m_nrele, tinm) {
+				SLIST_REMOVE_HEAD(&mli->mli_relinmhead,
+				    in6m_nrele);
+				in6m_release_locked(inm);
+			}
+		}
+	}
+
+out_locked:
+	MLD_UNLOCK();
+	IN6_MULTI_UNLOCK();
+}
+
+/*
+ * Update host report group timer.
+ * Will update the global pending timer flags.
+ */
+static void
+mld_v1_process_group_timer(struct in6_multi *inm, const int version)
+{
+	INIT_VNET_INET6(curvnet);
+	int report_timer_expired;
+
+	IN6_MULTI_LOCK_ASSERT();
+	MLD_LOCK_ASSERT();
+
+	if (inm->in6m_timer == 0) {
+		report_timer_expired = 0;
+	} else if (--inm->in6m_timer == 0) {
+		report_timer_expired = 1;
+	} else {
+		V_current_state_timers_running6 = 1;
+		return;
+	}
+
+	switch (inm->in6m_state) {
+	case MLD_NOT_MEMBER:
+	case MLD_SILENT_MEMBER:
+	case MLD_IDLE_MEMBER:
+	case MLD_LAZY_MEMBER:
+	case MLD_SLEEPING_MEMBER:
+	case MLD_AWAKENING_MEMBER:
+		break;
+	case MLD_REPORTING_MEMBER:
+		if (report_timer_expired) {
+			inm->in6m_state = MLD_IDLE_MEMBER;
+			(void)mld_v1_transmit_report(inm,
+			     MLD_LISTENER_REPORT);
+		}
+		break;
+	case MLD_G_QUERY_PENDING_MEMBER:
+	case MLD_SG_QUERY_PENDING_MEMBER:
+	case MLD_LEAVING_MEMBER:
 		break;
+	}
+}
 
-	case MLD_LISTENER_REPORT:
+/*
+ * Update a group's timers for MLDv2.
+ * Will update the global pending timer flags.
+ * Note: Unlocked read from mli.
+ */
+static void
+mld_v2_process_group_timers(struct mld_ifinfo *mli,
+    struct ifqueue *qrq, struct ifqueue *scq,
+    struct in6_multi *inm, const int uri_fasthz)
+{
+	INIT_VNET_INET6(curvnet);
+	int query_response_timer_expired;
+	int state_change_retransmit_timer_expired;
+#ifdef KTR
+	char ip6tbuf[INET6_ADDRSTRLEN];
+#endif
+
+	IN6_MULTI_LOCK_ASSERT();
+	MLD_LOCK_ASSERT();
+
+	query_response_timer_expired = 0;
+	state_change_retransmit_timer_expired = 0;
+
+	/*
+	 * During a transition from compatibility mode back to MLDv2,
+	 * a group record in REPORTING state may still have its group
+	 * timer active. This is a no-op in this function; it is easier
+	 * to deal with it here than to complicate the slow-timeout path.
+	 */
+	if (inm->in6m_timer == 0) {
+		query_response_timer_expired = 0;
+	} else if (--inm->in6m_timer == 0) {
+		query_response_timer_expired = 1;
+	} else {
+		V_current_state_timers_running6 = 1;
+	}
+
+	if (inm->in6m_sctimer == 0) {
+		state_change_retransmit_timer_expired = 0;
+	} else if (--inm->in6m_sctimer == 0) {
+		state_change_retransmit_timer_expired = 1;
+	} else {
+		V_state_change_timers_running6 = 1;
+	}
+
+	/* We are in fasttimo, so be quick about it. */
+	if (!state_change_retransmit_timer_expired &&
+	    !query_response_timer_expired)
+		return;
+
+	switch (inm->in6m_state) {
+	case MLD_NOT_MEMBER:
+	case MLD_SILENT_MEMBER:
+	case MLD_SLEEPING_MEMBER:
+	case MLD_LAZY_MEMBER:
+	case MLD_AWAKENING_MEMBER:
+	case MLD_IDLE_MEMBER:
+		break;
+	case MLD_G_QUERY_PENDING_MEMBER:
+	case MLD_SG_QUERY_PENDING_MEMBER:
 		/*
-		 * For fast leave to work, we have to know that we are the
-		 * last person to send a report for this group.  Reports
-		 * can potentially get looped back if we are a multicast
-		 * router, so discard reports sourced by me.
-		 * Note that it is impossible to check IFF_LOOPBACK flag of
-		 * ifp for this purpose, since ip6_mloopback pass the physical
-		 * interface to looutput.
+		 * Respond to a previously pending Group-Specific
+		 * or Group-and-Source-Specific query by enqueueing
+		 * the appropriate Current-State report for
+		 * immediate transmission.
 		 */
-		if (m->m_flags & M_LOOP) /* XXX: grotty flag, but efficient */
-			break;
+		if (query_response_timer_expired) {
+			int retval;
+
+			retval = mld_v2_enqueue_group_record(qrq, inm, 0, 1,
+			    (inm->in6m_state == MLD_SG_QUERY_PENDING_MEMBER));
+			CTR2(KTR_MLD, "%s: enqueue record = %d",
+			    __func__, retval);
+			inm->in6m_state = MLD_REPORTING_MEMBER;
+			in6m_clear_recorded(inm);
+		}
+		/* FALLTHROUGH */
+	case MLD_REPORTING_MEMBER:
+	case MLD_LEAVING_MEMBER:
+		if (state_change_retransmit_timer_expired) {
+			/*
+			 * State-change retransmission timer fired.
+			 * If there are any further pending retransmissions,
+			 * set the global pending state-change flag, and
+			 * reset the timer.
+			 */
+			if (--inm->in6m_scrv > 0) {
+				inm->in6m_sctimer = uri_fasthz;
+				V_state_change_timers_running6 = 1;
+			}
+			/*
+			 * Retransmit the previously computed state-change
+			 * report. If there are no further pending
+			 * retransmissions, the mbuf queue will be consumed.
+			 * Update T0 state to T1 as we have now sent
+			 * a state-change.
+			 */
+			(void)mld_v2_merge_state_changes(inm, scq);
+
+			in6m_commit(inm);
+			CTR3(KTR_MLD, "%s: T1 -> T0 for %s/%s", __func__,
+			    ip6_sprintf(ip6tbuf, &inm->in6m_addr),
+			    inm->in6m_ifp->if_xname);
+
+			/*
+			 * If we are leaving the group for good, make sure
+			 * we release MLD's reference to it.
+			 * This release must be deferred using a SLIST,
+			 * as we are called from a loop which traverses
+			 * the in_ifmultiaddr TAILQ.
+			 */
+			if (inm->in6m_state == MLD_LEAVING_MEMBER &&
+			    inm->in6m_scrv == 0) {
+				inm->in6m_state = MLD_NOT_MEMBER;
+				SLIST_INSERT_HEAD(&mli->mli_relinmhead,
+				    inm, in6m_nrele);
+			}
+		}
+		break;
+	}
+}
 
-		if (!IN6_IS_ADDR_MULTICAST(&mld_addr))
-			break;
+/*
+ * Switch to a different version on the given interface,
+ * as per Section 9.12.
+ */
+static void
+mld_set_version(struct mld_ifinfo *mli, const int version)
+{
 
+	MLD_LOCK_ASSERT();
+
+	CTR4(KTR_MLD, "%s: switching to v%d on ifp %p(%s)", __func__,
+	    version, mli->mli_ifp, mli->mli_ifp->if_xname);
+
+	if (version == MLD_VERSION_1) {
+		int old_version_timer;
 		/*
-		 * If we belong to the group being reported, stop
-		 * our timer for that group.
+		 * Compute the "Older Version Querier Present" timer as per
+		 * Section 9.12.
 		 */
-		IN6_LOOKUP_MULTI(mld_addr, ifp, in6m);
-		if (in6m) {
-			in6m->in6m_timer = 0; /* transit to idle state */
-			in6m->in6m_state = MLD_OTHERLISTENER; /* clear flag */
+		old_version_timer = mli->mli_rv * mli->mli_qi + mli->mli_qri;
+		old_version_timer *= PR_SLOWHZ;
+
+		if (version == MLD_VERSION_1) {
+			mli->mli_v1_timer = old_version_timer;
 		}
-		break;
-	default:		/* this is impossible */
-		log(LOG_ERR, "mld6_input: illegal type(%d)", mldh->mld_type);
-		break;
 	}
 
-	m_freem(m);
+	if (mli->mli_v1_timer > 0) {
+		if (mli->mli_version != MLD_VERSION_1) {
+			mli->mli_version = MLD_VERSION_1;
+			mld_v2_cancel_link_timers(mli);
+		}
+	}
 }
 
+/*
+ * Cancel pending MLDv2 timers for the given link and all groups
+ * joined on it; state-change, general-query, and group-query timers.
+ */
 static void
-mld6_sendpkt(struct in6_multi *in6m, int type, const struct in6_addr *dst)
+mld_v2_cancel_link_timers(struct mld_ifinfo *mli)
 {
 	INIT_VNET_INET6(curvnet);
-	struct mbuf *mh, *md;
-	struct mld_hdr *mldh;
-	struct ip6_hdr *ip6;
-	struct ip6_moptions im6o;
-	struct in6_ifaddr *ia;
-	struct ifnet *ifp = in6m->in6m_ifp;
-	struct ifnet *outif = NULL;
+	struct ifmultiaddr	*ifma;
+	struct ifnet		*ifp;
+	struct in6_multi		*inm;
+
+	CTR3(KTR_MLD, "%s: cancel v2 timers on ifp %p(%s)", __func__,
+	    mli->mli_ifp, mli->mli_ifp->if_xname);
+
+	IN6_MULTI_LOCK_ASSERT();
+	MLD_LOCK_ASSERT();
 
 	/*
-	 * At first, find a link local address on the outgoing interface
-	 * to use as the source address of the MLD packet.
+	 * Fast-track this potentially expensive operation
+	 * by checking all the global 'timer pending' flags.
 	 */
-	if ((ia = in6ifa_ifpforlinklocal(ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST))
-	    == NULL)
+	if (!V_interface_timers_running6 &&
+	    !V_state_change_timers_running6 &&
+	    !V_current_state_timers_running6)
 		return;
 
-	/*
-	 * Allocate mbufs to store ip6 header and MLD header.
-	 * We allocate 2 mbufs and make chain in advance because
-	 * it is more convenient when inserting the hop-by-hop option later.
-	 */
+	mli->mli_v2_timer = 0;
+
+	ifp = mli->mli_ifp;
+
+	IF_ADDR_LOCK(ifp);
+	TAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
+		if (ifma->ifma_addr->sa_family != AF_INET6)
+			continue;
+		inm = (struct in6_multi *)ifma->ifma_protospec;
+		switch (inm->in6m_state) {
+		case MLD_NOT_MEMBER:
+		case MLD_SILENT_MEMBER:
+		case MLD_IDLE_MEMBER:
+		case MLD_LAZY_MEMBER:
+		case MLD_SLEEPING_MEMBER:
+		case MLD_AWAKENING_MEMBER:
+			break;
+		case MLD_LEAVING_MEMBER:
+			/*
+			 * If we are leaving the group and switching
+			 * version, we need to release the final
+			 * reference held for issuing the INCLUDE {}.
+			 *
+			 * SMPNG: Must drop and re-acquire IF_ADDR_LOCK
+			 * around in6m_release_locked(), as it is not
+			 * a recursive mutex.
+			 */
+			IF_ADDR_UNLOCK(ifp);
+			in6m_release_locked(inm);
+			IF_ADDR_LOCK(ifp);
+			/* FALLTHROUGH */
+		case MLD_G_QUERY_PENDING_MEMBER:
+		case MLD_SG_QUERY_PENDING_MEMBER:
+			in6m_clear_recorded(inm);
+			/* FALLTHROUGH */
+		case MLD_REPORTING_MEMBER:
+			inm->in6m_sctimer = 0;
+			inm->in6m_timer = 0;
+			inm->in6m_state = MLD_REPORTING_MEMBER;
+			/*
+			 * Free any pending MLDv2 state-change records.
+			 */
+			_IF_DRAIN(&inm->in6m_scq);
+			break;
+		}
+	}
+	IF_ADDR_UNLOCK(ifp);
+}
+
+/*
+ * Global slowtimo handler.
+ * VIMAGE: Timeout handlers are expected to service all vimages.
+ */
+void
+mld_slowtimo(void)
+{
+	VNET_ITERATOR_DECL(vnet_iter);
+
+	VNET_LIST_RLOCK();
+	VNET_FOREACH(vnet_iter) {
+		CURVNET_SET(vnet_iter);
+		mld_slowtimo_vnet();
+		CURVNET_RESTORE();
+	}
+	VNET_LIST_RUNLOCK();
+}
+
+/*
+ * Per-vnet slowtimo handler.
+ */
+static void
+mld_slowtimo_vnet(void)
+{
+	INIT_VNET_INET6(curvnet);
+	struct mld_ifinfo *mli;
+
+	MLD_LOCK();
+
+	LIST_FOREACH(mli, &V_mli_head, mli_link) {
+		mld_v1_process_querier_timers(mli);
+	}
+
+	MLD_UNLOCK();
+}
+
+/*
+ * Update the Older Version Querier Present timers for a link.
+ * See Section 9.12 of RFC 3810.
+ */
+static void
+mld_v1_process_querier_timers(struct mld_ifinfo *mli)
+{
+	INIT_VNET_INET6(curvnet);
+
+	MLD_LOCK_ASSERT();
+
+	if (mli->mli_v1_timer == 0) {
+		/*
+		 * MLDv1 Querier Present timers expired; revert to MLDv2.
+		 */
+		if (mli->mli_version != MLD_VERSION_2) {
+			CTR5(KTR_MLD,
+			    "%s: transition from v%d -> v%d on %p(%s)",
+			    __func__, mli->mli_version, MLD_VERSION_2,
+			    mli->mli_ifp, mli->mli_ifp->if_xname);
+			mli->mli_version = MLD_VERSION_2;
+		}
+	}
+}
+
+/*
+ * Transmit an MLDv1 report immediately.
+ */
+static int
+mld_v1_transmit_report(struct in6_multi *in6m, const int type)
+{
+	struct ifnet		*ifp;
+	struct in6_ifaddr	*ia;
+	struct ip6_hdr		*ip6;
+	struct mbuf		*mh, *md;
+	struct mld_hdr		*mld;
+
+	IN6_MULTI_LOCK_ASSERT();
+	MLD_LOCK_ASSERT();
+
+	ifp = in6m->in6m_ifp;
+	ia = in6ifa_ifpforlinklocal(ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST);
+	/* ia may be NULL if link-local address is tentative. */
+
 	MGETHDR(mh, M_DONTWAIT, MT_HEADER);
 	if (mh == NULL)
-		return;
+		return (ENOMEM);
 	MGET(md, M_DONTWAIT, MT_DATA);
 	if (md == NULL) {
 		m_free(mh);
-		return;
+		return (ENOMEM);
 	}
 	mh->m_next = md;
 
-	mh->m_pkthdr.rcvif = NULL;
+	/*
+	 * FUTURE: Consider increasing alignment by ETHER_HDR_LEN, so
+	 * that ether_output() does not need to allocate another mbuf
+	 * for the header in the most common case.
+	 */
+	MH_ALIGN(mh, sizeof(struct ip6_hdr));
 	mh->m_pkthdr.len = sizeof(struct ip6_hdr) + sizeof(struct mld_hdr);
 	mh->m_len = sizeof(struct ip6_hdr);
-	MH_ALIGN(mh, sizeof(struct ip6_hdr));
 
-	/* fill in the ip6 header */
 	ip6 = mtod(mh, struct ip6_hdr *);
 	ip6->ip6_flow = 0;
 	ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
 	ip6->ip6_vfc |= IPV6_VERSION;
-	/* ip6_plen will be set later */
 	ip6->ip6_nxt = IPPROTO_ICMPV6;
-	/* ip6_hlim will be set by im6o.im6o_multicast_hlim */
-	ip6->ip6_src = ia->ia_addr.sin6_addr;
-	ip6->ip6_dst = dst ? *dst : in6m->in6m_addr;
+	ip6->ip6_src = ia ? ia->ia_addr.sin6_addr : in6addr_any;
+	ip6->ip6_dst = in6m->in6m_addr;
 
-	/* fill in the MLD header */
 	md->m_len = sizeof(struct mld_hdr);
-	mldh = mtod(md, struct mld_hdr *);
-	mldh->mld_type = type;
-	mldh->mld_code = 0;
-	mldh->mld_cksum = 0;
-	/* XXX: we assume the function will not be called for query messages */
-	mldh->mld_maxdelay = 0;
-	mldh->mld_reserved = 0;
-	mldh->mld_addr = in6m->in6m_addr;
-	in6_clearscope(&mldh->mld_addr); /* XXX */
-	mldh->mld_cksum = in6_cksum(mh, IPPROTO_ICMPV6, sizeof(struct ip6_hdr),
-				    sizeof(struct mld_hdr));
-
-	/* construct multicast option */
-	bzero(&im6o, sizeof(im6o));
-	im6o.im6o_multicast_ifp = ifp;
-	im6o.im6o_multicast_hlim = 1;
+	mld = mtod(md, struct mld_hdr *);
+	mld->mld_type = type;
+	mld->mld_code = 0;
+	mld->mld_cksum = 0;
+	mld->mld_maxdelay = 0;
+	mld->mld_reserved = 0;
+	mld->mld_addr = in6m->in6m_addr;
+	in6_clearscope(&mld->mld_addr);
+	mld->mld_cksum = in6_cksum(mh, IPPROTO_ICMPV6,
+	    sizeof(struct ip6_hdr), sizeof(struct mld_hdr));
+
+	mld_save_context(mh, ifp);
+	mh->m_flags |= M_MLDV1;
+
+	mld_dispatch_packet(mh);
+
+	return (0);
+}
+
+/*
+ * Process a state change from the upper layer for the given IPv6 group.
+ *
+ * Each socket holds a reference on the in_multi in its own ip_moptions.
+ * The socket layer will have made the necessary updates to.the group
+ * state, it is now up to MLD to issue a state change report if there
+ * has been any change between T0 (when the last state-change was issued)
+ * and T1 (now).
+ *
+ * We use the MLDv2 state machine at group level. The MLd module
+ * however makes the decision as to which MLD protocol version to speak.
+ * A state change *from* INCLUDE {} always means an initial join.
+ * A state change *to* INCLUDE {} always means a final leave.
+ *
+ * If delay is non-zero, and the state change is an initial multicast
+ * join, the state change report will be delayed by 'delay' ticks
+ * in units of PR_FASTHZ if MLDv1 is active on the link; otherwise
+ * the initial MLDv2 state change report will be delayed by whichever
+ * is sooner, a pending state-change timer or delay itself.
+ *
+ * VIMAGE: curvnet should have been set by caller, as this routine
+ * is called from the socket option handlers.
+ */
+int
+mld_change_state(struct in6_multi *inm, const int delay)
+{
+	struct mld_ifinfo *mli;
+	struct ifnet *ifp;
+	int error;
+
+	IN6_MULTI_LOCK_ASSERT();
+
+	error = 0;
 
 	/*
-	 * Request loopback of the report if we are acting as a multicast
-	 * router, so that the process-level routing daemon can hear it.
+	 * Try to detect if the upper layer just asked us to change state
+	 * for an interface which has now gone away.
 	 */
-	im6o.im6o_multicast_loop = (ip6_mrouter != NULL);
+	KASSERT(inm->in6m_ifma != NULL, ("%s: no ifma", __func__));
+	ifp = inm->in6m_ifma->ifma_ifp;
+	if (ifp != NULL) {
+		/*
+		 * Sanity check that netinet6's notion of ifp is the
+		 * same as net's.
+		 */
+		KASSERT(inm->in6m_ifp == ifp, ("%s: bad ifp", __func__));
+	}
 
-	/* increment output statictics */
-	ICMP6STAT_INC(icp6s_outhist[type]);
+	MLD_LOCK();
 
-	ip6_output(mh, &V_ip6_opts, NULL, 0, &im6o, &outif, NULL);
-	if (outif) {
-		icmp6_ifstat_inc(outif, ifs6_out_msg);
-		switch (type) {
-		case MLD_LISTENER_QUERY:
-			icmp6_ifstat_inc(outif, ifs6_out_mldquery);
+	mli = MLD_IFINFO(ifp);
+	KASSERT(mli != NULL, ("%s: no mld_ifinfo for ifp %p", __func__, ifp));
+
+	/*
+	 * If we detect a state transition to or from MCAST_UNDEFINED
+	 * for this group, then we are starting or finishing an MLD
+	 * life cycle for this group.
+	 */
+	if (inm->in6m_st[1].iss_fmode != inm->in6m_st[0].iss_fmode) {
+		CTR3(KTR_MLD, "%s: inm transition %d -> %d", __func__,
+		    inm->in6m_st[0].iss_fmode, inm->in6m_st[1].iss_fmode);
+		if (inm->in6m_st[0].iss_fmode == MCAST_UNDEFINED) {
+			CTR1(KTR_MLD, "%s: initial join", __func__);
+			error = mld_initial_join(inm, mli, delay);
+			goto out_locked;
+		} else if (inm->in6m_st[1].iss_fmode == MCAST_UNDEFINED) {
+			CTR1(KTR_MLD, "%s: final leave", __func__);
+			mld_final_leave(inm, mli);
+			goto out_locked;
+		}
+	} else {
+		CTR1(KTR_MLD, "%s: filter set change", __func__);
+	}
+
+	error = mld_handle_state_change(inm, mli);
+
+out_locked:
+	MLD_UNLOCK();
+	return (error);
+}
+
+/*
+ * Perform the initial join for an MLD group.
+ *
+ * When joining a group:
+ *  If the group should have its MLD traffic suppressed, do nothing.
+ *  MLDv1 starts sending MLDv1 host membership reports.
+ *  MLDv2 will schedule an MLDv2 state-change report containing the
+ *  initial state of the membership.
+ *
+ * If the delay argument is non-zero, then we must delay sending the
+ * initial state change for delay ticks (in units of PR_FASTHZ).
+ */
+static int
+mld_initial_join(struct in6_multi *inm, struct mld_ifinfo *mli,
+    const int delay)
+{
+	INIT_VNET_INET6(curvnet);
+	struct ifnet		*ifp;
+	struct ifqueue		*ifq;
+	int			 error, retval, syncstates;
+	int			 odelay;
+#ifdef KTR
+	char			 ip6tbuf[INET6_ADDRSTRLEN];
+#endif
+
+	CTR4(KTR_MLD, "%s: initial join %s on ifp %p(%s)",
+	    __func__, ip6_sprintf(ip6tbuf, &inm->in6m_addr),
+	    inm->in6m_ifp, inm->in6m_ifp->if_xname);
+
+	error = 0;
+	syncstates = 1;
+
+	ifp = inm->in6m_ifp;
+
+	IN6_MULTI_LOCK_ASSERT();
+	MLD_LOCK_ASSERT();
+
+	KASSERT(mli && mli->mli_ifp == ifp, ("%s: inconsistent ifp", __func__));
+
+	/*
+	 * Groups joined on loopback or marked as 'not reported',
+	 * enter the MLD_SILENT_MEMBER state and
+	 * are never reported in any protocol exchanges.
+	 * All other groups enter the appropriate state machine
+	 * for the version in use on this link.
+	 * A link marked as MLIF_SILENT causes MLD to be completely
+	 * disabled for the link.
+	 */
+	if ((ifp->if_flags & IFF_LOOPBACK) ||
+	    (mli->mli_flags & MLIF_SILENT) ||
+	    !mld_is_addr_reported(&inm->in6m_addr)) {
+		CTR1(KTR_MLD,
+"%s: not kicking state machine for silent group", __func__);
+		inm->in6m_state = MLD_SILENT_MEMBER;
+		inm->in6m_timer = 0;
+	} else {
+		/*
+		 * Deal with overlapping in_multi lifecycle.
+		 * If this group was LEAVING, then make sure
+		 * we drop the reference we picked up to keep the
+		 * group around for the final INCLUDE {} enqueue.
+		 */
+		if (mli->mli_version == MLD_VERSION_2 &&
+		    inm->in6m_state == MLD_LEAVING_MEMBER)
+			in6m_release_locked(inm);
+
+		inm->in6m_state = MLD_REPORTING_MEMBER;
+
+		switch (mli->mli_version) {
+		case MLD_VERSION_1:
+			/*
+			 * If a delay was provided, only use it if
+			 * it is greater than the delay normally
+			 * used for an MLDv1 state change report,
+			 * and delay sending the initial MLDv1 report
+			 * by not transitioning to the IDLE state.
+			 */
+			odelay = MLD_RANDOM_DELAY(MLD_V1_MAX_RI * PR_FASTHZ);
+			if (delay) {
+				inm->in6m_timer = max(delay, odelay);
+				V_current_state_timers_running6 = 1;
+			} else {
+				inm->in6m_state = MLD_IDLE_MEMBER;
+				error = mld_v1_transmit_report(inm,
+				     MLD_LISTENER_REPORT);
+				if (error == 0) {
+					inm->in6m_timer = odelay;
+					V_current_state_timers_running6 = 1;
+				}
+			}
 			break;
-		case MLD_LISTENER_REPORT:
-			icmp6_ifstat_inc(outif, ifs6_out_mldreport);
+
+		case MLD_VERSION_2:
+			/*
+			 * Defer update of T0 to T1, until the first copy
+			 * of the state change has been transmitted.
+			 */
+			syncstates = 0;
+
+			/*
+			 * Immediately enqueue a State-Change Report for
+			 * this interface, freeing any previous reports.
+			 * Don't kick the timers if there is nothing to do,
+			 * or if an error occurred.
+			 */
+			ifq = &inm->in6m_scq;
+			_IF_DRAIN(ifq);
+			retval = mld_v2_enqueue_group_record(ifq, inm, 1,
+			    0, 0);
+			CTR2(KTR_MLD, "%s: enqueue record = %d",
+			    __func__, retval);
+			if (retval <= 0) {
+				error = retval * -1;
+				break;
+			}
+
+			/*
+			 * Schedule transmission of pending state-change
+			 * report up to RV times for this link. The timer
+			 * will fire at the next mld_fasttimo (~200ms),
+			 * giving us an opportunity to merge the reports.
+			 *
+			 * If a delay was provided to this function, only
+			 * use this delay if sooner than the existing one.
+			 */
+			KASSERT(mli->mli_rv > 1,
+			   ("%s: invalid robustness %d", __func__,
+			    mli->mli_rv));
+			inm->in6m_scrv = mli->mli_rv;
+			if (delay) {
+				if (inm->in6m_sctimer > 1) {
+					inm->in6m_sctimer =
+					    min(inm->in6m_sctimer, delay);
+				} else
+					inm->in6m_sctimer = delay;
+			} else
+				inm->in6m_sctimer = 1;
+			V_state_change_timers_running6 = 1;
+
+			error = 0;
 			break;
-		case MLD_LISTENER_DONE:
-			icmp6_ifstat_inc(outif, ifs6_out_mlddone);
+		}
+	}
+
+	/*
+	 * Only update the T0 state if state change is atomic,
+	 * i.e. we don't need to wait for a timer to fire before we
+	 * can consider the state change to have been communicated.
+	 */
+	if (syncstates) {
+		in6m_commit(inm);
+		CTR3(KTR_MLD, "%s: T1 -> T0 for %s/%s", __func__,
+		    ip6_sprintf(ip6tbuf, &inm->in6m_addr),
+		    inm->in6m_ifp->if_xname);
+	}
+
+	return (error);
+}
+
+/*
+ * Issue an intermediate state change during the life-cycle.
+ */
+static int
+mld_handle_state_change(struct in6_multi *inm, struct mld_ifinfo *mli)
+{
+	INIT_VNET_INET6(curvnet);
+	struct ifnet		*ifp;
+	int			 retval;
+#ifdef KTR
+	char			 ip6tbuf[INET6_ADDRSTRLEN];
+#endif
+
+	CTR4(KTR_MLD, "%s: state change for %s on ifp %p(%s)",
+	    __func__, ip6_sprintf(ip6tbuf, &inm->in6m_addr),
+	    inm->in6m_ifp, inm->in6m_ifp->if_xname);
+
+	ifp = inm->in6m_ifp;
+
+	IN6_MULTI_LOCK_ASSERT();
+	MLD_LOCK_ASSERT();
+
+	KASSERT(mli && mli->mli_ifp == ifp,
+	    ("%s: inconsistent ifp", __func__));
+
+	if ((ifp->if_flags & IFF_LOOPBACK) ||
+	    (mli->mli_flags & MLIF_SILENT) ||
+	    !mld_is_addr_reported(&inm->in6m_addr) ||
+	    (mli->mli_version != MLD_VERSION_2)) {
+		if (!mld_is_addr_reported(&inm->in6m_addr)) {
+			CTR1(KTR_MLD,
+"%s: not kicking state machine for silent group", __func__);
+		}
+		CTR1(KTR_MLD, "%s: nothing to do", __func__);
+		in6m_commit(inm);
+		CTR3(KTR_MLD, "%s: T1 -> T0 for %s/%s", __func__,
+		    ip6_sprintf(ip6tbuf, &inm->in6m_addr),
+		    inm->in6m_ifp->if_xname);
+		return (0);
+	}
+
+	_IF_DRAIN(&inm->in6m_scq);
+
+	retval = mld_v2_enqueue_group_record(&inm->in6m_scq, inm, 1, 0, 0);
+	CTR2(KTR_MLD, "%s: enqueue record = %d", __func__, retval);
+	if (retval <= 0)
+		return (-retval);
+
+	/*
+	 * If record(s) were enqueued, start the state-change
+	 * report timer for this group.
+	 */
+	inm->in6m_scrv = mli->mli_rv;
+	inm->in6m_sctimer = 1;
+	V_state_change_timers_running6 = 1;
+
+	return (0);
+}
+
+/*
+ * Perform the final leave for a multicast address.
+ *
+ * When leaving a group:
+ *  MLDv1 sends a DONE message, if and only if we are the reporter.
+ *  MLDv2 enqueues a state-change report containing a transition
+ *  to INCLUDE {} for immediate transmission.
+ */
+static void
+mld_final_leave(struct in6_multi *inm, struct mld_ifinfo *mli)
+{
+	INIT_VNET_INET6(curvnet);
+	int syncstates;
+#ifdef KTR
+	char ip6tbuf[INET6_ADDRSTRLEN];
+#endif
+
+	syncstates = 1;
+
+	CTR4(KTR_MLD, "%s: final leave %s on ifp %p(%s)",
+	    __func__, ip6_sprintf(ip6tbuf, &inm->in6m_addr),
+	    inm->in6m_ifp, inm->in6m_ifp->if_xname);
+
+	IN6_MULTI_LOCK_ASSERT();
+	MLD_LOCK_ASSERT();
+
+	switch (inm->in6m_state) {
+	case MLD_NOT_MEMBER:
+	case MLD_SILENT_MEMBER:
+	case MLD_LEAVING_MEMBER:
+		/* Already leaving or left; do nothing. */
+		CTR1(KTR_MLD,
+"%s: not kicking state machine for silent group", __func__);
+		break;
+	case MLD_REPORTING_MEMBER:
+	case MLD_IDLE_MEMBER:
+	case MLD_G_QUERY_PENDING_MEMBER:
+	case MLD_SG_QUERY_PENDING_MEMBER:
+		if (mli->mli_version == MLD_VERSION_1) {
+#ifdef INVARIANTS
+			if (inm->in6m_state == MLD_G_QUERY_PENDING_MEMBER ||
+			    inm->in6m_state == MLD_SG_QUERY_PENDING_MEMBER)
+			panic("%s: MLDv2 state reached, not MLDv2 mode",
+			     __func__);
+#endif
+			mld_v1_transmit_report(inm, MLD_LISTENER_DONE);
+			inm->in6m_state = MLD_NOT_MEMBER;
+		} else if (mli->mli_version == MLD_VERSION_2) {
+			/*
+			 * Stop group timer and all pending reports.
+			 * Immediately enqueue a state-change report
+			 * TO_IN {} to be sent on the next fast timeout,
+			 * giving us an opportunity to merge reports.
+			 */
+			_IF_DRAIN(&inm->in6m_scq);
+			inm->in6m_timer = 0;
+			inm->in6m_scrv = mli->mli_rv;
+			CTR4(KTR_MLD, "%s: Leaving %s/%s with %d "
+			    "pending retransmissions.", __func__,
+			    ip6_sprintf(ip6tbuf, &inm->in6m_addr),
+			    inm->in6m_ifp->if_xname, inm->in6m_scrv);
+			if (inm->in6m_scrv == 0) {
+				inm->in6m_state = MLD_NOT_MEMBER;
+				inm->in6m_sctimer = 0;
+			} else {
+				int retval;
+
+				in6m_acquire_locked(inm);
+
+				retval = mld_v2_enqueue_group_record(
+				    &inm->in6m_scq, inm, 1, 0, 0);
+				KASSERT(retval != 0,
+				    ("%s: enqueue record = %d", __func__,
+				     retval));
+
+				inm->in6m_state = MLD_LEAVING_MEMBER;
+				inm->in6m_sctimer = 1;
+				V_state_change_timers_running6 = 1;
+				syncstates = 0;
+			}
 			break;
 		}
+		break;
+	case MLD_LAZY_MEMBER:
+	case MLD_SLEEPING_MEMBER:
+	case MLD_AWAKENING_MEMBER:
+		/* Our reports are suppressed; do nothing. */
+		break;
+	}
+
+	if (syncstates) {
+		in6m_commit(inm);
+		CTR3(KTR_MLD, "%s: T1 -> T0 for %s/%s", __func__,
+		    ip6_sprintf(ip6tbuf, &inm->in6m_addr),
+		    inm->in6m_ifp->if_xname);
+		inm->in6m_st[1].iss_fmode = MCAST_UNDEFINED;
+		CTR3(KTR_MLD, "%s: T1 now MCAST_UNDEFINED for %p/%s",
+		    __func__, &inm->in6m_addr, inm->in6m_ifp->if_xname);
 	}
 }
 
 /*
- * Add an address to the list of IP6 multicast addresses for a given interface.
- * Add source addresses to the list also, if upstream router is MLDv2 capable
- * and the number of source is not 0.
+ * Enqueue an MLDv2 group record to the given output queue.
+ *
+ * If is_state_change is zero, a current-state record is appended.
+ * If is_state_change is non-zero, a state-change report is appended.
+ *
+ * If is_group_query is non-zero, an mbuf packet chain is allocated.
+ * If is_group_query is zero, and if there is a packet with free space
+ * at the tail of the queue, it will be appended to providing there
+ * is enough free space.
+ * Otherwise a new mbuf packet chain is allocated.
+ *
+ * If is_source_query is non-zero, each source is checked to see if
+ * it was recorded for a Group-Source query, and will be omitted if
+ * it is not both in-mode and recorded.
+ *
+ * The function will attempt to allocate leading space in the packet
+ * for the IPv6+ICMP headers to be prepended without fragmenting the chain.
+ *
+ * If successful the size of all data appended to the queue is returned,
+ * otherwise an error code less than zero is returned, or zero if
+ * no record(s) were appended.
  */
-struct in6_multi *
-in6_addmulti(struct in6_addr *maddr6, struct ifnet *ifp,
-    int *errorp, int delay)
+static int
+mld_v2_enqueue_group_record(struct ifqueue *ifq, struct in6_multi *inm,
+    const int is_state_change, const int is_group_query,
+    const int is_source_query)
 {
-	struct in6_multi *in6m;
+	struct mldv2_record	 mr;
+	struct mldv2_record	*pmr;
+	struct ifnet		*ifp;
+	struct ip6_msource	*ims, *nims;
+	struct mbuf		*m0, *m, *md;
+	int			 error, is_filter_list_change;
+	int			 minrec0len, m0srcs, msrcs, nbytes, off;
+	int			 record_has_sources;
+	int			 now;
+	int			 type;
+	uint8_t			 mode;
+#ifdef KTR
+	char			 ip6tbuf[INET6_ADDRSTRLEN];
+#endif
 
-	*errorp = 0;
-	in6m = NULL;
+	IN6_MULTI_LOCK_ASSERT();
+
+	error = 0;
+	ifp = inm->in6m_ifp;
+	is_filter_list_change = 0;
+	m = NULL;
+	m0 = NULL;
+	m0srcs = 0;
+	msrcs = 0;
+	nbytes = 0;
+	nims = NULL;
+	record_has_sources = 1;
+	pmr = NULL;
+	type = MLD_DO_NOTHING;
+	mode = inm->in6m_st[1].iss_fmode;
 
-	/*IN6_MULTI_LOCK();*/
+	/*
+	 * If we did not transition out of ASM mode during t0->t1,
+	 * and there are no source nodes to process, we can skip
+	 * the generation of source records.
+	 */
+	if (inm->in6m_st[0].iss_asm > 0 && inm->in6m_st[1].iss_asm > 0 &&
+	    inm->in6m_nsrc == 0)
+		record_has_sources = 0;
 
-	IN6_LOOKUP_MULTI(*maddr6, ifp, in6m);
-	if (in6m != NULL) {
+	if (is_state_change) {
 		/*
-		 * If we already joined this group, just bump the
-		 * refcount and return it.
+		 * Queue a state change record.
+		 * If the mode did not change, and there are non-ASM
+		 * listeners or source filters present,
+		 * we potentially need to issue two records for the group.
+		 * If we are transitioning to MCAST_UNDEFINED, we need
+		 * not send any sources.
+		 * If there are ASM listeners, and there was no filter
+		 * mode transition of any kind, do nothing.
 		 */
-		KASSERT(in6m->in6m_refcount >= 1,
-		    ("%s: bad refcount %d", __func__, in6m->in6m_refcount));
-		++in6m->in6m_refcount;
-	} else do {
-		struct in6_multi *nin6m;
-		struct ifmultiaddr *ifma;
-		struct sockaddr_in6 sa6;
-
-		bzero(&sa6, sizeof(sa6));
-		sa6.sin6_family = AF_INET6;
-		sa6.sin6_len = sizeof(struct sockaddr_in6);
-		sa6.sin6_addr = *maddr6;
-
-		*errorp = if_addmulti(ifp, (struct sockaddr *)&sa6, &ifma);
-		if (*errorp)
-			break;
+		if (mode != inm->in6m_st[0].iss_fmode) {
+			if (mode == MCAST_EXCLUDE) {
+				CTR1(KTR_MLD, "%s: change to EXCLUDE",
+				    __func__);
+				type = MLD_CHANGE_TO_EXCLUDE_MODE;
+			} else {
+				CTR1(KTR_MLD, "%s: change to INCLUDE",
+				    __func__);
+				type = MLD_CHANGE_TO_INCLUDE_MODE;
+				if (mode == MCAST_UNDEFINED)
+					record_has_sources = 0;
+			}
+		} else {
+			if (record_has_sources) {
+				is_filter_list_change = 1;
+			} else {
+				type = MLD_DO_NOTHING;
+			}
+		}
+	} else {
+		/*
+		 * Queue a current state record.
+		 */
+		if (mode == MCAST_EXCLUDE) {
+			type = MLD_MODE_IS_EXCLUDE;
+		} else if (mode == MCAST_INCLUDE) {
+			type = MLD_MODE_IS_INCLUDE;
+			KASSERT(inm->in6m_st[1].iss_asm == 0,
+			    ("%s: inm %p is INCLUDE but ASM count is %d",
+			     __func__, inm, inm->in6m_st[1].iss_asm));
+		}
+	}
+
+	/*
+	 * Generate the filter list changes using a separate function.
+	 */
+	if (is_filter_list_change)
+		return (mld_v2_enqueue_filter_change(ifq, inm));
+
+	if (type == MLD_DO_NOTHING) {
+		CTR3(KTR_MLD, "%s: nothing to do for %s/%s",
+		    __func__, ip6_sprintf(ip6tbuf, &inm->in6m_addr),
+		    inm->in6m_ifp->if_xname);
+		return (0);
+	}
+
+	/*
+	 * If any sources are present, we must be able to fit at least
+	 * one in the trailing space of the tail packet's mbuf,
+	 * ideally more.
+	 */
+	minrec0len = sizeof(struct mldv2_record);
+	if (record_has_sources)
+		minrec0len += sizeof(struct in6_addr);
+
+	CTR4(KTR_MLD, "%s: queueing %s for %s/%s", __func__,
+	    mld_rec_type_to_str(type),
+	    ip6_sprintf(ip6tbuf, &inm->in6m_addr),
+	    inm->in6m_ifp->if_xname);
+
+	/*
+	 * Check if we have a packet in the tail of the queue for this
+	 * group into which the first group record for this group will fit.
+	 * Otherwise allocate a new packet.
+	 * Always allocate leading space for IP6+RA+ICMPV6+REPORT.
+	 * Note: Group records for G/GSR query responses MUST be sent
+	 * in their own packet.
+	 */
+	m0 = ifq->ifq_tail;
+	if (!is_group_query &&
+	    m0 != NULL &&
+	    (m0->m_pkthdr.PH_vt.vt_nrecs + 1 <= MLD_V2_REPORT_MAXRECS) &&
+	    (m0->m_pkthdr.len + minrec0len) <
+	     (ifp->if_mtu - MLD_MTUSPACE)) {
+		m0srcs = (ifp->if_mtu - m0->m_pkthdr.len -
+			    sizeof(struct mldv2_record)) /
+			    sizeof(struct in6_addr);
+		m = m0;
+		CTR1(KTR_MLD, "%s: use existing packet", __func__);
+	} else {
+		if (_IF_QFULL(ifq)) {
+			CTR1(KTR_MLD, "%s: outbound queue full", __func__);
+			return (-ENOMEM);
+		}
+		m = NULL;
+		m0srcs = (ifp->if_mtu - MLD_MTUSPACE -
+		    sizeof(struct mldv2_record)) / sizeof(struct in6_addr);
+		if (!is_state_change && !is_group_query)
+			m = m_getcl(M_DONTWAIT, MT_DATA, M_PKTHDR);
+		if (m == NULL)
+			m = m_gethdr(M_DONTWAIT, MT_DATA);
+		if (m == NULL)
+			return (-ENOMEM);
+
+		mld_save_context(m, ifp);
+
+		CTR1(KTR_MLD, "%s: allocated first packet", __func__);
+	}
+
+	/*
+	 * Append group record.
+	 * If we have sources, we don't know how many yet.
+	 */
+	mr.mr_type = type;
+	mr.mr_datalen = 0;
+	mr.mr_numsrc = 0;
+	mr.mr_addr = inm->in6m_addr;
+	in6_clearscope(&mr.mr_addr);
+	if (!m_append(m, sizeof(struct mldv2_record), (void *)&mr)) {
+		if (m != m0)
+			m_freem(m);
+		CTR1(KTR_MLD, "%s: m_append() failed.", __func__);
+		return (-ENOMEM);
+	}
+	nbytes += sizeof(struct mldv2_record);
+
+	/*
+	 * Append as many sources as will fit in the first packet.
+	 * If we are appending to a new packet, the chain allocation
+	 * may potentially use clusters; use m_getptr() in this case.
+	 * If we are appending to an existing packet, we need to obtain
+	 * a pointer to the group record after m_append(), in case a new
+	 * mbuf was allocated.
+	 * Only append sources which are in-mode at t1. If we are
+	 * transitioning to MCAST_UNDEFINED state on the group, do not
+	 * include source entries.
+	 * Only report recorded sources in our filter set when responding
+	 * to a group-source query.
+	 */
+	if (record_has_sources) {
+		if (m == m0) {
+			md = m_last(m);
+			pmr = (struct mldv2_record *)(mtod(md, uint8_t *) +
+			    md->m_len - nbytes);
+		} else {
+			md = m_getptr(m, 0, &off);
+			pmr = (struct mldv2_record *)(mtod(md, uint8_t *) +
+			    off);
+		}
+		msrcs = 0;
+		RB_FOREACH_SAFE(ims, ip6_msource_tree, &inm->in6m_srcs,
+		    nims) {
+			CTR2(KTR_MLD, "%s: visit node %s", __func__,
+			    ip6_sprintf(ip6tbuf, &ims->im6s_addr));
+			now = im6s_get_mode(inm, ims, 1);
+			CTR2(KTR_MLD, "%s: node is %d", __func__, now);
+			if ((now != mode) ||
+			    (now == mode && mode == MCAST_UNDEFINED)) {
+				CTR1(KTR_MLD, "%s: skip node", __func__);
+				continue;
+			}
+			if (is_source_query && ims->im6s_stp == 0) {
+				CTR1(KTR_MLD, "%s: skip unrecorded node",
+				    __func__);
+				continue;
+			}
+			CTR1(KTR_MLD, "%s: append node", __func__);
+			if (!m_append(m, sizeof(struct in6_addr),
+			    (void *)&ims->im6s_addr)) {
+				if (m != m0)
+					m_freem(m);
+				CTR1(KTR_MLD, "%s: m_append() failed.",
+				    __func__);
+				return (-ENOMEM);
+			}
+			nbytes += sizeof(struct in6_addr);
+			++msrcs;
+			if (msrcs == m0srcs)
+				break;
+		}
+		CTR2(KTR_MLD, "%s: msrcs is %d this packet", __func__,
+		    msrcs);
+		pmr->mr_numsrc = htons(msrcs);
+		nbytes += (msrcs * sizeof(struct in6_addr));
+	}
+
+	if (is_source_query && msrcs == 0) {
+		CTR1(KTR_MLD, "%s: no recorded sources to report", __func__);
+		if (m != m0)
+			m_freem(m);
+		return (0);
+	}
+
+	/*
+	 * We are good to go with first packet.
+	 */
+	if (m != m0) {
+		CTR1(KTR_MLD, "%s: enqueueing first packet", __func__);
+		m->m_pkthdr.PH_vt.vt_nrecs = 1;
+		_IF_ENQUEUE(ifq, m);
+	} else
+		m->m_pkthdr.PH_vt.vt_nrecs++;
+
+	/*
+	 * No further work needed if no source list in packet(s).
+	 */
+	if (!record_has_sources)
+		return (nbytes);
+
+	/*
+	 * Whilst sources remain to be announced, we need to allocate
+	 * a new packet and fill out as many sources as will fit.
+	 * Always try for a cluster first.
+	 */
+	while (nims != NULL) {
+		if (_IF_QFULL(ifq)) {
+			CTR1(KTR_MLD, "%s: outbound queue full", __func__);
+			return (-ENOMEM);
+		}
+		m = m_getcl(M_DONTWAIT, MT_DATA, M_PKTHDR);
+		if (m == NULL)
+			m = m_gethdr(M_DONTWAIT, MT_DATA);
+		if (m == NULL)
+			return (-ENOMEM);
+		mld_save_context(m, ifp);
+		md = m_getptr(m, 0, &off);
+		pmr = (struct mldv2_record *)(mtod(md, uint8_t *) + off);
+		CTR1(KTR_MLD, "%s: allocated next packet", __func__);
+
+		if (!m_append(m, sizeof(struct mldv2_record), (void *)&mr)) {
+			if (m != m0)
+				m_freem(m);
+			CTR1(KTR_MLD, "%s: m_append() failed.", __func__);
+			return (-ENOMEM);
+		}
+		m->m_pkthdr.PH_vt.vt_nrecs = 1;
+		nbytes += sizeof(struct mldv2_record);
+
+		m0srcs = (ifp->if_mtu - MLD_MTUSPACE -
+		    sizeof(struct mldv2_record)) / sizeof(struct in6_addr);
+
+		msrcs = 0;
+		RB_FOREACH_FROM(ims, ip6_msource_tree, nims) {
+			CTR2(KTR_MLD, "%s: visit node %s",
+			    __func__, ip6_sprintf(ip6tbuf, &ims->im6s_addr));
+			now = im6s_get_mode(inm, ims, 1);
+			if ((now != mode) ||
+			    (now == mode && mode == MCAST_UNDEFINED)) {
+				CTR1(KTR_MLD, "%s: skip node", __func__);
+				continue;
+			}
+			if (is_source_query && ims->im6s_stp == 0) {
+				CTR1(KTR_MLD, "%s: skip unrecorded node",
+				    __func__);
+				continue;
+			}
+			CTR1(KTR_MLD, "%s: append node", __func__);
+			if (!m_append(m, sizeof(struct in6_addr),
+			    (void *)&ims->im6s_addr)) {
+				if (m != m0)
+					m_freem(m);
+				CTR1(KTR_MLD, "%s: m_append() failed.",
+				    __func__);
+				return (-ENOMEM);
+			}
+			++msrcs;
+			if (msrcs == m0srcs)
+				break;
+		}
+		pmr->mr_numsrc = htons(msrcs);
+		nbytes += (msrcs * sizeof(struct in6_addr));
+
+		CTR1(KTR_MLD, "%s: enqueueing next packet", __func__);
+		_IF_ENQUEUE(ifq, m);
+	}
+
+	return (nbytes);
+}
+
+/*
+ * Type used to mark record pass completion.
+ * We exploit the fact we can cast to this easily from the
+ * current filter modes on each ip_msource node.
+ */
+typedef enum {
+	REC_NONE = 0x00,	/* MCAST_UNDEFINED */
+	REC_ALLOW = 0x01,	/* MCAST_INCLUDE */
+	REC_BLOCK = 0x02,	/* MCAST_EXCLUDE */
+	REC_FULL = REC_ALLOW | REC_BLOCK
+} rectype_t;
+
+/*
+ * Enqueue an MLDv2 filter list change to the given output queue.
+ *
+ * Source list filter state is held in an RB-tree. When the filter list
+ * for a group is changed without changing its mode, we need to compute
+ * the deltas between T0 and T1 for each source in the filter set,
+ * and enqueue the appropriate ALLOW_NEW/BLOCK_OLD records.
+ *
+ * As we may potentially queue two record types, and the entire R-B tree
+ * needs to be walked at once, we break this out into its own function
+ * so we can generate a tightly packed queue of packets.
+ *
+ * XXX This could be written to only use one tree walk, although that makes
+ * serializing into the mbuf chains a bit harder. For now we do two walks
+ * which makes things easier on us, and it may or may not be harder on
+ * the L2 cache.
+ *
+ * If successful the size of all data appended to the queue is returned,
+ * otherwise an error code less than zero is returned, or zero if
+ * no record(s) were appended.
+ */
+static int
+mld_v2_enqueue_filter_change(struct ifqueue *ifq, struct in6_multi *inm)
+{
+	static const int MINRECLEN =
+	    sizeof(struct mldv2_record) + sizeof(struct in6_addr);
+	struct ifnet		*ifp;
+	struct mldv2_record	 mr;
+	struct mldv2_record	*pmr;
+	struct ip6_msource	*ims, *nims;
+	struct mbuf		*m, *m0, *md;
+	int			 m0srcs, nbytes, npbytes, off, rsrcs, schanged;
+	int			 nallow, nblock;
+	uint8_t			 mode, now, then;
+	rectype_t		 crt, drt, nrt;
+#ifdef KTR
+	char			 ip6tbuf[INET6_ADDRSTRLEN];
+#endif
 
+	IN6_MULTI_LOCK_ASSERT();
+
+	if (inm->in6m_nsrc == 0 ||
+	    (inm->in6m_st[0].iss_asm > 0 && inm->in6m_st[1].iss_asm > 0))
+		return (0);
+
+	ifp = inm->in6m_ifp;			/* interface */
+	mode = inm->in6m_st[1].iss_fmode;	/* filter mode at t1 */
+	crt = REC_NONE;	/* current group record type */
+	drt = REC_NONE;	/* mask of completed group record types */
+	nrt = REC_NONE;	/* record type for current node */
+	m0srcs = 0;	/* # source which will fit in current mbuf chain */
+	npbytes = 0;	/* # of bytes appended this packet */
+	nbytes = 0;	/* # of bytes appended to group's state-change queue */
+	rsrcs = 0;	/* # sources encoded in current record */
+	schanged = 0;	/* # nodes encoded in overall filter change */
+	nallow = 0;	/* # of source entries in ALLOW_NEW */
+	nblock = 0;	/* # of source entries in BLOCK_OLD */
+	nims = NULL;	/* next tree node pointer */
+
+	/*
+	 * For each possible filter record mode.
+	 * The first kind of source we encounter tells us which
+	 * is the first kind of record we start appending.
+	 * If a node transitioned to UNDEFINED at t1, its mode is treated
+	 * as the inverse of the group's filter mode.
+	 */
+	while (drt != REC_FULL) {
+		do {
+			m0 = ifq->ifq_tail;
+			if (m0 != NULL &&
+			    (m0->m_pkthdr.PH_vt.vt_nrecs + 1 <=
+			     MLD_V2_REPORT_MAXRECS) &&
+			    (m0->m_pkthdr.len + MINRECLEN) <
+			     (ifp->if_mtu - MLD_MTUSPACE)) {
+				m = m0;
+				m0srcs = (ifp->if_mtu - m0->m_pkthdr.len -
+					    sizeof(struct mldv2_record)) /
+					    sizeof(struct in6_addr);
+				CTR1(KTR_MLD,
+				    "%s: use previous packet", __func__);
+			} else {
+				m = m_getcl(M_DONTWAIT, MT_DATA, M_PKTHDR);
+				if (m == NULL)
+					m = m_gethdr(M_DONTWAIT, MT_DATA);
+				if (m == NULL) {
+					CTR1(KTR_MLD,
+					    "%s: m_get*() failed", __func__);
+					return (-ENOMEM);
+				}
+				m->m_pkthdr.PH_vt.vt_nrecs = 0;
+				mld_save_context(m, ifp);
+				m0srcs = (ifp->if_mtu - MLD_MTUSPACE -
+				    sizeof(struct mldv2_record)) /
+				    sizeof(struct in6_addr);
+				npbytes = 0;
+				CTR1(KTR_MLD,
+				    "%s: allocated new packet", __func__);
+			}
+			/*
+			 * Append the MLD group record header to the
+			 * current packet's data area.
+			 * Recalculate pointer to free space for next
+			 * group record, in case m_append() allocated
+			 * a new mbuf or cluster.
+			 */
+			memset(&mr, 0, sizeof(mr));
+			mr.mr_addr = inm->in6m_addr;
+			in6_clearscope(&mr.mr_addr);
+			if (!m_append(m, sizeof(mr), (void *)&mr)) {
+				if (m != m0)
+					m_freem(m);
+				CTR1(KTR_MLD,
+				    "%s: m_append() failed", __func__);
+				return (-ENOMEM);
+			}
+			npbytes += sizeof(struct mldv2_record);
+			if (m != m0) {
+				/* new packet; offset in chain */
+				md = m_getptr(m, npbytes -
+				    sizeof(struct mldv2_record), &off);
+				pmr = (struct mldv2_record *)(mtod(md,
+				    uint8_t *) + off);
+			} else {
+				/* current packet; offset from last append */
+				md = m_last(m);
+				pmr = (struct mldv2_record *)(mtod(md,
+				    uint8_t *) + md->m_len -
+				    sizeof(struct mldv2_record));
+			}
+			/*
+			 * Begin walking the tree for this record type
+			 * pass, or continue from where we left off
+			 * previously if we had to allocate a new packet.
+			 * Only report deltas in-mode at t1.
+			 * We need not report included sources as allowed
+			 * if we are in inclusive mode on the group,
+			 * however the converse is not true.
+			 */
+			rsrcs = 0;
+			if (nims == NULL) {
+				nims = RB_MIN(ip6_msource_tree,
+				    &inm->in6m_srcs);
+			}
+			RB_FOREACH_FROM(ims, ip6_msource_tree, nims) {
+				CTR2(KTR_MLD, "%s: visit node %s", __func__,
+				    ip6_sprintf(ip6tbuf, &ims->im6s_addr));
+				now = im6s_get_mode(inm, ims, 1);
+				then = im6s_get_mode(inm, ims, 0);
+				CTR3(KTR_MLD, "%s: mode: t0 %d, t1 %d",
+				    __func__, then, now);
+				if (now == then) {
+					CTR1(KTR_MLD,
+					    "%s: skip unchanged", __func__);
+					continue;
+				}
+				if (mode == MCAST_EXCLUDE &&
+				    now == MCAST_INCLUDE) {
+					CTR1(KTR_MLD,
+					    "%s: skip IN src on EX group",
+					    __func__);
+					continue;
+				}
+				nrt = (rectype_t)now;
+				if (nrt == REC_NONE)
+					nrt = (rectype_t)(~mode & REC_FULL);
+				if (schanged++ == 0) {
+					crt = nrt;
+				} else if (crt != nrt)
+					continue;
+				if (!m_append(m, sizeof(struct in6_addr),
+				    (void *)&ims->im6s_addr)) {
+					if (m != m0)
+						m_freem(m);
+					CTR1(KTR_MLD,
+					    "%s: m_append() failed", __func__);
+					return (-ENOMEM);
+				}
+				nallow += !!(crt == REC_ALLOW);
+				nblock += !!(crt == REC_BLOCK);
+				if (++rsrcs == m0srcs)
+					break;
+			}
+			/*
+			 * If we did not append any tree nodes on this
+			 * pass, back out of allocations.
+			 */
+			if (rsrcs == 0) {
+				npbytes -= sizeof(struct mldv2_record);
+				if (m != m0) {
+					CTR1(KTR_MLD,
+					    "%s: m_free(m)", __func__);
+					m_freem(m);
+				} else {
+					CTR1(KTR_MLD,
+					    "%s: m_adj(m, -mr)", __func__);
+					m_adj(m, -((int)sizeof(
+					    struct mldv2_record)));
+				}
+				continue;
+			}
+			npbytes += (rsrcs * sizeof(struct in6_addr));
+			if (crt == REC_ALLOW)
+				pmr->mr_type = MLD_ALLOW_NEW_SOURCES;
+			else if (crt == REC_BLOCK)
+				pmr->mr_type = MLD_BLOCK_OLD_SOURCES;
+			pmr->mr_numsrc = htons(rsrcs);
+			/*
+			 * Count the new group record, and enqueue this
+			 * packet if it wasn't already queued.
+			 */
+			m->m_pkthdr.PH_vt.vt_nrecs++;
+			if (m != m0)
+				_IF_ENQUEUE(ifq, m);
+			nbytes += npbytes;
+		} while (nims != NULL);
+		drt |= crt;
+		crt = (~crt & REC_FULL);
+	}
+
+	CTR3(KTR_MLD, "%s: queued %d ALLOW_NEW, %d BLOCK_OLD", __func__,
+	    nallow, nblock);
+
+	return (nbytes);
+}
+
+static int
+mld_v2_merge_state_changes(struct in6_multi *inm, struct ifqueue *ifscq)
+{
+	struct ifqueue	*gq;
+	struct mbuf	*m;		/* pending state-change */
+	struct mbuf	*m0;		/* copy of pending state-change */
+	struct mbuf	*mt;		/* last state-change in packet */
+	int		 docopy, domerge;
+	u_int		 recslen;
+
+	docopy = 0;
+	domerge = 0;
+	recslen = 0;
+
+	IN6_MULTI_LOCK_ASSERT();
+	MLD_LOCK_ASSERT();
+
+	/*
+	 * If there are further pending retransmissions, make a writable
+	 * copy of each queued state-change message before merging.
+	 */
+	if (inm->in6m_scrv > 0)
+		docopy = 1;
+
+	gq = &inm->in6m_scq;
+#ifdef KTR
+	if (gq->ifq_head == NULL) {
+		CTR2(KTR_MLD, "%s: WARNING: queue for inm %p is empty",
+		    __func__, inm);
+	}
+#endif
+
+	m = gq->ifq_head;
+	while (m != NULL) {
 		/*
-		 * If ifma->ifma_protospec is null, then if_addmulti() created
-		 * a new record.  Otherwise, bump refcount, and we are done.
+		 * Only merge the report into the current packet if
+		 * there is sufficient space to do so; an MLDv2 report
+		 * packet may only contain 65,535 group records.
+		 * Always use a simple mbuf chain concatentation to do this,
+		 * as large state changes for single groups may have
+		 * allocated clusters.
 		 */
-		if (ifma->ifma_protospec != NULL) {
-			in6m = ifma->ifma_protospec;
-			++in6m->in6m_refcount;
-			break;
+		domerge = 0;
+		mt = ifscq->ifq_tail;
+		if (mt != NULL) {
+			recslen = m_length(m, NULL);
+
+			if ((mt->m_pkthdr.PH_vt.vt_nrecs +
+			    m->m_pkthdr.PH_vt.vt_nrecs <=
+			    MLD_V2_REPORT_MAXRECS) &&
+			    (mt->m_pkthdr.len + recslen <=
+			    (inm->in6m_ifp->if_mtu - MLD_MTUSPACE)))
+				domerge = 1;
 		}
 
-		nin6m = malloc(sizeof(*nin6m), M_IP6MADDR, M_NOWAIT | M_ZERO);
-		if (nin6m == NULL) {
-			if_delmulti_ifma(ifma);
-			break;
+		if (!domerge && _IF_QFULL(gq)) {
+			CTR2(KTR_MLD,
+			    "%s: outbound queue full, skipping whole packet %p",
+			    __func__, m);
+			mt = m->m_nextpkt;
+			if (!docopy)
+				m_freem(m);
+			m = mt;
+			continue;
 		}
 
-		nin6m->in6m_addr = *maddr6;
-		nin6m->in6m_ifp = ifp;
-		nin6m->in6m_refcount = 1;
-		nin6m->in6m_ifma = ifma;
-		ifma->ifma_protospec = nin6m;
+		if (!docopy) {
+			CTR2(KTR_MLD, "%s: dequeueing %p", __func__, m);
+			_IF_DEQUEUE(gq, m0);
+			m = m0->m_nextpkt;
+		} else {
+			CTR2(KTR_MLD, "%s: copying %p", __func__, m);
+			m0 = m_dup(m, M_NOWAIT);
+			if (m0 == NULL)
+				return (ENOMEM);
+			m0->m_nextpkt = NULL;
+			m = m->m_nextpkt;
+		}
 
-		nin6m->in6m_timer_ch = malloc(sizeof(*nin6m->in6m_timer_ch),
-		    M_IP6MADDR, M_NOWAIT);
-		if (nin6m->in6m_timer_ch == NULL) {
-			free(nin6m, M_IP6MADDR);
-			if_delmulti_ifma(ifma);
-			break;
+		if (!domerge) {
+			CTR3(KTR_MLD, "%s: queueing %p to ifscq %p)",
+			    __func__, m0, ifscq);
+			_IF_ENQUEUE(ifscq, m0);
+		} else {
+			struct mbuf *mtl;	/* last mbuf of packet mt */
+
+			CTR3(KTR_MLD, "%s: merging %p with ifscq tail %p)",
+			    __func__, m0, mt);
+
+			mtl = m_last(mt);
+			m0->m_flags &= ~M_PKTHDR;
+			mt->m_pkthdr.len += recslen;
+			mt->m_pkthdr.PH_vt.vt_nrecs +=
+			    m0->m_pkthdr.PH_vt.vt_nrecs;
+
+			mtl->m_next = m0;
 		}
+	}
+
+	return (0);
+}
+
+/*
+ * Respond to a pending MLDv2 General Query.
+ */
+static void
+mld_v2_dispatch_general_query(struct mld_ifinfo *mli)
+{
+	INIT_VNET_INET6(curvnet);
+	struct ifmultiaddr	*ifma, *tifma;
+	struct ifnet		*ifp;
+	struct in6_multi	*inm;
+	int			 retval;
+
+	IN6_MULTI_LOCK_ASSERT();
+	MLD_LOCK_ASSERT();
+
+	KASSERT(mli->mli_version == MLD_VERSION_2,
+	    ("%s: called when version %d", __func__, mli->mli_version));
+
+	ifp = mli->mli_ifp;
+
+	IF_ADDR_LOCK(ifp);
+	TAILQ_FOREACH_SAFE(ifma, &ifp->if_multiaddrs, ifma_link, tifma) {
+		if (ifma->ifma_addr->sa_family != AF_INET6 ||
+		    ifma->ifma_protospec == NULL)
+			continue;
 
-		LIST_INSERT_HEAD(&in6_multihead, nin6m, in6m_entry);
+		inm = (struct in6_multi *)ifma->ifma_protospec;
+		KASSERT(ifp == inm->in6m_ifp,
+		    ("%s: inconsistent ifp", __func__));
 
-		callout_init(nin6m->in6m_timer_ch, 0);
-		nin6m->in6m_timer = delay;
-		if (nin6m->in6m_timer > 0) {
-			nin6m->in6m_state = MLD_REPORTPENDING;
-			mld_starttimer(nin6m);
+		switch (inm->in6m_state) {
+		case MLD_NOT_MEMBER:
+		case MLD_SILENT_MEMBER:
+			break;
+		case MLD_REPORTING_MEMBER:
+		case MLD_IDLE_MEMBER:
+		case MLD_LAZY_MEMBER:
+		case MLD_SLEEPING_MEMBER:
+		case MLD_AWAKENING_MEMBER:
+			inm->in6m_state = MLD_REPORTING_MEMBER;
+			retval = mld_v2_enqueue_group_record(&mli->mli_gq,
+			    inm, 0, 0, 0);
+			CTR2(KTR_MLD, "%s: enqueue record = %d",
+			    __func__, retval);
+			break;
+		case MLD_G_QUERY_PENDING_MEMBER:
+		case MLD_SG_QUERY_PENDING_MEMBER:
+		case MLD_LEAVING_MEMBER:
+			break;
 		}
+	}
+	IF_ADDR_UNLOCK(ifp);
+
+	mld_dispatch_queue(&mli->mli_gq, MLD_MAX_RESPONSE_BURST);
+
+	/*
+	 * Slew transmission of bursts over 500ms intervals.
+	 */
+	if (mli->mli_gq.ifq_head != NULL) {
+		mli->mli_v2_timer = 1 + MLD_RANDOM_DELAY(
+		    MLD_RESPONSE_BURST_INTERVAL);
+		V_interface_timers_running6 = 1;
+	}
+}
+
+/*
+ * Transmit the next pending message in the output queue.
+ *
+ * VIMAGE: Needs to store/restore vnet pointer on a per-mbuf-chain basis.
+ * MRT: Nothing needs to be done, as MLD traffic is always local to
+ * a link and uses a link-scope multicast address.
+ */
+static void
+mld_dispatch_packet(struct mbuf *m)
+{
+	struct ip6_moptions	 im6o;
+	struct ifnet		*ifp;
+	struct ifnet		*oifp;
+	struct mbuf		*m0;
+	struct mbuf		*md;
+	struct ip6_hdr		*ip6;
+	struct mld_hdr		*mld;
+	int			 error;
+	int			 off;
+	int			 type;
+	uint32_t		 ifindex;
+
+	CTR2(KTR_MLD, "%s: transmit %p", __func__, m);
+
+	/*
+	 * Set VNET image pointer from enqueued mbuf chain
+	 * before doing anything else. Whilst we use interface
+	 * indexes to guard against interface detach, they are
+	 * unique to each VIMAGE and must be retrieved.
+	 */
+	CURVNET_SET(m->m_pkthdr.header);
+	INIT_VNET_NET(curvnet);
+	INIT_VNET_INET6(curvnet);
+	ifindex = mld_restore_context(m);
+
+	/*
+	 * Check if the ifnet still exists. This limits the scope of
+	 * any race in the absence of a global ifp lock for low cost
+	 * (an array lookup).
+	 */
+	ifp = ifnet_byindex(ifindex);
+	if (ifp == NULL) {
+		CTR3(KTR_MLD, "%s: dropped %p as ifindex %u went away.",
+		    __func__, m, ifindex);
+		m_freem(m);
+		IP6STAT_INC(ip6s_noroute);
+		goto out;
+	}
 
-		mld6_start_listening(nin6m);
+	im6o.im6o_multicast_hlim  = 1;
+	im6o.im6o_multicast_loop = (V_ip6_mrouter != NULL);
+	im6o.im6o_multicast_ifp = ifp;
 
-		in6m = nin6m;
+	if (m->m_flags & M_MLDV1) {
+		m0 = m;
+	} else {
+		m0 = mld_v2_encap_report(ifp, m);
+		if (m0 == NULL) {
+			CTR2(KTR_MLD, "%s: dropped %p", __func__, m);
+			m_freem(m);
+			IP6STAT_INC(ip6s_odropped);
+			goto out;
+		}
+	}
 
-	} while (0);
+	mld_scrub_context(m0);
+	m->m_flags &= ~(M_PROTOFLAGS);
+	m0->m_pkthdr.rcvif = V_loif;
 
-	/*IN6_MULTI_UNLOCK();*/
+	ip6 = mtod(m0, struct ip6_hdr *);
+#if 0
+	(void)in6_setscope(&ip6->ip6_dst, ifp, NULL);	/* XXX LOR */
+#else
+	/*
+	 * XXX XXX Break some KPI rules to prevent an LOR which would
+	 * occur if we called in6_setscope() at transmission.
+	 * See comments at top of file.
+	 */
+	MLD_EMBEDSCOPE(&ip6->ip6_dst, ifp->if_index);
+#endif
 
-	return (in6m);
+	/*
+	 * Retrieve the ICMPv6 type before handoff to ip6_output(),
+	 * so we can bump the stats.
+	 */
+	md = m_getptr(m0, sizeof(struct ip6_hdr), &off);
+	mld = (struct mld_hdr *)(mtod(md, uint8_t *) + off);
+	type = mld->mld_type;
+
+	error = ip6_output(m0, &mld_po, NULL, IPV6_UNSPECSRC, &im6o,
+	    &oifp, NULL);
+	if (error) {
+		CTR3(KTR_MLD, "%s: ip6_output(%p) = %d", __func__, m0, error);
+		goto out;
+	}
+	ICMP6STAT_INC(icp6s_outhist[type]);
+	if (oifp != NULL) {
+		icmp6_ifstat_inc(oifp, ifs6_out_msg);
+		switch (type) {
+		case MLD_LISTENER_REPORT:
+		case MLDV2_LISTENER_REPORT:
+			icmp6_ifstat_inc(oifp, ifs6_out_mldreport);
+			break;
+		case MLD_LISTENER_DONE:
+			icmp6_ifstat_inc(oifp, ifs6_out_mlddone);
+			break;
+		}
+	}
+out:
+	/*
+	 * We must restore the existing vnet pointer before continuing.
+	 */
+	CURVNET_RESTORE();
 }
 
 /*
- * Delete a multicast address record.
+ * Encapsulate an MLDv2 report.
+ *
+ * KAME IPv6 requires that hop-by-hop options be passed separately,
+ * and that the IPv6 header be prepended in a separate mbuf.
  *
- * TODO: Locking, as per netinet.
+ * Returns a pointer to the new mbuf chain head, or NULL if the
+ * allocation failed.
  */
-void
-in6_delmulti(struct in6_multi *in6m)
+static struct mbuf *
+mld_v2_encap_report(struct ifnet *ifp, struct mbuf *m)
 {
-	struct ifmultiaddr *ifma;
+	INIT_VNET_INET6(curvnet);
+	struct mbuf		*mh;
+	struct mldv2_report	*mld;
+	struct ip6_hdr		*ip6;
+	struct in6_ifaddr	*ia;
+	int			 mldreclen;
+
+	KASSERT(ifp != NULL, ("%s: null ifp", __func__));
+	KASSERT((m->m_flags & M_PKTHDR),
+	    ("%s: mbuf chain %p is !M_PKTHDR", __func__, m));
+
+	/*
+	 * RFC3590: OK to send as :: or tentative during DAD.
+	 */
+	ia = in6ifa_ifpforlinklocal(ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST);
+	if (ia == NULL)
+		CTR1(KTR_MLD, "%s: warning: ia is NULL", __func__);
 
-	KASSERT(in6m->in6m_refcount >= 1, ("%s: freeing freed in6m", __func__));
+	MGETHDR(mh, M_DONTWAIT, MT_HEADER);
+	if (mh == NULL) {
+		m_freem(m);
+		return (NULL);
+	}
+	MH_ALIGN(mh, sizeof(struct ip6_hdr) + sizeof(struct mldv2_report));
 
-	if (--in6m->in6m_refcount == 0) {
-		mld_stoptimer(in6m);
-		mld6_stop_listening(in6m);
+	mldreclen = m_length(m, NULL);
+	CTR2(KTR_MLD, "%s: mldreclen is %d", __func__, mldreclen);
 
-		ifma = in6m->in6m_ifma;
-		KASSERT(ifma->ifma_protospec == in6m,
-		    ("%s: ifma_protospec != in6m", __func__));
-		ifma->ifma_protospec = NULL;
+	mh->m_len = sizeof(struct ip6_hdr) + sizeof(struct mldv2_report);
+	mh->m_pkthdr.len = sizeof(struct ip6_hdr) +
+	    sizeof(struct mldv2_report) + mldreclen;
 
-		LIST_REMOVE(in6m, in6m_entry);
-		free(in6m->in6m_timer_ch, M_IP6MADDR);
-		free(in6m, M_IP6MADDR);
+	ip6 = mtod(mh, struct ip6_hdr *);
+	ip6->ip6_flow = 0;
+	ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
+	ip6->ip6_vfc |= IPV6_VERSION;
+	ip6->ip6_nxt = IPPROTO_ICMPV6;
+	ip6->ip6_src = ia ? ia->ia_addr.sin6_addr : in6addr_any;
+	ip6->ip6_dst = in6addr_linklocal_allv2routers;
+	/* scope ID will be set in netisr */
+
+	mld = (struct mldv2_report *)(ip6 + 1);
+	mld->mld_type = MLDV2_LISTENER_REPORT;
+	mld->mld_code = 0;
+	mld->mld_cksum = 0;
+	mld->mld_v2_reserved = 0;
+	mld->mld_v2_numrecs = htons(m->m_pkthdr.PH_vt.vt_nrecs);
+	m->m_pkthdr.PH_vt.vt_nrecs = 0;
+
+	mh->m_next = m;
+	mld->mld_cksum = in6_cksum(mh, IPPROTO_ICMPV6,
+	    sizeof(struct ip6_hdr), sizeof(struct mldv2_report) + mldreclen);
+
+	return (mh);
+}
+
+#ifdef KTR
+static char *
+mld_rec_type_to_str(const int type)
+{
 
-		if_delmulti_ifma(ifma);
+	switch (type) {
+		case MLD_CHANGE_TO_EXCLUDE_MODE:
+			return "TO_EX";
+			break;
+		case MLD_CHANGE_TO_INCLUDE_MODE:
+			return "TO_IN";
+			break;
+		case MLD_MODE_IS_EXCLUDE:
+			return "MODE_EX";
+			break;
+		case MLD_MODE_IS_INCLUDE:
+			return "MODE_IN";
+			break;
+		case MLD_ALLOW_NEW_SOURCES:
+			return "ALLOW_NEW";
+			break;
+		case MLD_BLOCK_OLD_SOURCES:
+			return "BLOCK_OLD";
+			break;
+		default:
+			break;
 	}
+	return "unknown";
+}
+#endif
+
+static void
+mld_sysinit(void)
+{
+
+	CTR1(KTR_MLD, "%s: initializing", __func__);
+	MLD_LOCK_INIT();
+
+	ip6_initpktopts(&mld_po);
+	mld_po.ip6po_hlim = 1;
+	mld_po.ip6po_hbh = &mld_ra.hbh;
+	mld_po.ip6po_prefer_tempaddr = IP6PO_TEMPADDR_NOTPREFER;
+	mld_po.ip6po_flags = IP6PO_DONTFRAG;
 }
+
+static void
+mld_sysuninit(void)
+{
+
+	CTR1(KTR_MLD, "%s: tearing down", __func__);
+	MLD_LOCK_DESTROY();
+}
+
+/*
+ * Initialize an MLDv2 instance.
+ * VIMAGE: Assumes curvnet set by caller and called per vimage.
+ */
+static int
+vnet_mld_iattach(const void *unused __unused)
+{
+	INIT_VNET_INET6(curvnet);
+
+	CTR1(KTR_MLD, "%s: initializing", __func__);
+
+	LIST_INIT(&V_mli_head);
+
+	V_current_state_timers_running6 = 0;
+	V_interface_timers_running6 = 0;
+	V_state_change_timers_running6 = 0;
+
+	/*
+	 * Initialize sysctls to default values.
+	 */
+	V_mld_gsrdelay.tv_sec = 10;
+	V_mld_gsrdelay.tv_usec = 0;
+
+	return (0);
+}
+
+static int
+vnet_mld_idetach(const void *unused __unused)
+{
+	INIT_VNET_INET6(curvnet);
+
+	CTR1(KTR_MLD, "%s: tearing down", __func__);
+
+	KASSERT(LIST_EMPTY(&V_mli_head),
+	    ("%s: mli list not empty; ifnets not detached?", __func__));
+
+	return (0);
+}
+
+#ifndef VIMAGE_GLOBALS
+static vnet_modinfo_t vnet_mld_modinfo = {
+	.vmi_id		= VNET_MOD_MLD,
+	.vmi_name	= "mld",
+	.vmi_dependson	= VNET_MOD_INET6,
+	.vmi_iattach	= vnet_mld_iattach,
+	.vmi_idetach	= vnet_mld_idetach
+};
+#endif
+
+static int
+mld_modevent(module_t mod, int type, void *unused __unused)
+{
+
+    switch (type) {
+    case MOD_LOAD:
+	mld_sysinit();
+#ifndef VIMAGE_GLOBALS
+	vnet_mod_register(&vnet_mld_modinfo);
+#else
+	vnet_mld_iattach(NULL);
+#endif
+	break;
+    case MOD_UNLOAD:
+#ifndef VIMAGE_GLOBALS
+#ifdef NOTYET
+	vnet_mod_deregister(&vnet_mld_modinfo);
+#endif
+#else
+	vnet_mld_idetach(NULL);
+#endif
+	mld_sysuninit();
+	break;
+    default:
+	return (EOPNOTSUPP);
+    }
+    return (0);
+}
+
+static moduledata_t mld_mod = {
+    "mld",
+    mld_modevent,
+    0
+};
+DECLARE_MODULE(mld, mld_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
diff --git a/sys/netinet6/mld6_var.h b/sys/netinet6/mld6_var.h
index 4f51b99..efd01ab 100644
--- a/sys/netinet6/mld6_var.h
+++ b/sys/netinet6/mld6_var.h
@@ -1,6 +1,5 @@
 /*-
- * Copyright (C) 1998 WIDE Project.
- * All rights reserved.
+ * Copyright (c) 2009 Bruce Simpson.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -10,14 +9,14 @@
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
- * 3. Neither the name of the project nor the names of its contributors
- *    may be used to endorse or promote products derived from this software
- *    without specific prior written permission.
+ * 3. The name of the author may not be used to endorse or promote
+ *    products derived from this software without specific prior written
+ *    permission.
  *
- * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
@@ -26,29 +25,139 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *	$KAME: mld6_var.h,v 1.4 2000/03/25 07:23:54 sumikawa Exp $
  * $FreeBSD$
  */
-
 #ifndef _NETINET6_MLD6_VAR_H_
 #define _NETINET6_MLD6_VAR_H_
 
+/*
+ * Multicast Listener Discovery (MLD)
+ * implementation-specific definitions.
+ */
+
 #ifdef _KERNEL
 
-#define MLD_RANDOM_DELAY(X) (arc4random() % (X) + 1)
+/*
+ * Per-link MLD state.
+ */
+struct mld_ifinfo {
+	LIST_ENTRY(mld_ifinfo) mli_link;
+	struct ifnet *mli_ifp;	/* interface this instance belongs to */
+	uint32_t mli_version;	/* MLDv1 Host Compatibility Mode */
+	uint32_t mli_v1_timer;	/* MLDv1 Querier Present timer (s) */
+	uint32_t mli_v2_timer;	/* MLDv2 General Query (interface) timer (s)*/
+	uint32_t mli_flags;	/* MLD per-interface flags */
+	uint32_t mli_rv;	/* MLDv2 Robustness Variable */
+	uint32_t mli_qi;	/* MLDv2 Query Interval (s) */
+	uint32_t mli_qri;	/* MLDv2 Query Response Interval (s) */
+	uint32_t mli_uri;	/* MLDv2 Unsolicited Report Interval (s) */
+	SLIST_HEAD(,in6_multi)	mli_relinmhead; /* released groups */
+	struct ifqueue	 mli_gq;	/* queue of general query responses */
+};
+#define MLIF_SILENT	0x00000001	/* Do not use MLD on this ifp */
+
+#define MLD_RANDOM_DELAY(X)		(arc4random() % (X) + 1)
+#define MLD_MAX_STATE_CHANGES		24 /* Max pending changes per group */
 
 /*
- * States for MLD stop-listening processing
+ * MLD per-group states.
  */
-#define MLD_OTHERLISTENER			0
-#define MLD_IREPORTEDLAST			1
-#define	MLD_REPORTPENDING			2 /* implementation specific */
+#define MLD_NOT_MEMBER			0 /* Can garbage collect group */
+#define MLD_SILENT_MEMBER		1 /* Do not perform MLD for group */
+#define MLD_REPORTING_MEMBER		2 /* MLDv1 we are reporter */
+#define MLD_IDLE_MEMBER			3 /* MLDv1 we reported last */
+#define MLD_LAZY_MEMBER			4 /* MLDv1 other member reporting */
+#define MLD_SLEEPING_MEMBER		5 /* MLDv1 start query response */
+#define MLD_AWAKENING_MEMBER		6 /* MLDv1 group timer will start */
+#define MLD_G_QUERY_PENDING_MEMBER	7 /* MLDv2 group query pending */
+#define MLD_SG_QUERY_PENDING_MEMBER	8 /* MLDv2 source query pending */
+#define MLD_LEAVING_MEMBER		9 /* MLDv2 dying gasp (pending last */
+					  /* retransmission of INCLUDE {}) */
+
+/*
+ * MLD version tag.
+ */
+#define MLD_VERSION_NONE		0 /* Invalid */
+#define MLD_VERSION_1			1
+#define MLD_VERSION_2			2 /* Default */
+
+/*
+ * MLDv2 protocol control variables.
+ */
+#define MLD_RV_INIT		2	/* Robustness Variable */
+#define MLD_RV_MIN		1
+#define MLD_RV_MAX		7
+
+#define MLD_QI_INIT		125	/* Query Interval (s) */
+#define MLD_QI_MIN		1
+#define MLD_QI_MAX		255
+
+#define MLD_QRI_INIT		10	/* Query Response Interval (s) */
+#define MLD_QRI_MIN		1
+#define MLD_QRI_MAX		255
+
+#define MLD_URI_INIT		3	/* Unsolicited Report Interval (s) */
+#define MLD_URI_MIN		0
+#define MLD_URI_MAX		10
+
+#define MLD_MAX_GS_SOURCES		256 /* # of sources in rx GS query */
+#define MLD_MAX_G_GS_PACKETS		8 /* # of packets to answer G/GS */
+#define MLD_MAX_STATE_CHANGE_PACKETS	8 /* # of packets per state change */
+#define MLD_MAX_RESPONSE_PACKETS	16 /* # of packets for general query */
+#define MLD_MAX_RESPONSE_BURST		4 /* # of responses to send at once */
+#define MLD_RESPONSE_BURST_INTERVAL	(PR_FASTHZ / 2)	/* 500ms */
+
+/*
+ * MLD-specific mbuf flags.
+ */
+#define M_MLDV1		M_PROTO1	/* Packet is MLDv1 */
+#define M_GROUPREC	M_PROTO3	/* mbuf chain is a group record */
+
+/*
+ * Leading space for MLDv2 reports inside MTU.
+ *
+ * NOTE: This differs from IGMPv3 significantly. KAME IPv6 requires
+ * that a fully formed mbuf chain *without* the Router Alert option
+ * is passed to ip6_output(), however we must account for it in the
+ * MTU if we need to split an MLDv2 report into several packets.
+ *
+ * We now put the MLDv2 report header in the initial mbuf containing
+ * the IPv6 header.
+ */
+#define	MLD_MTUSPACE	(sizeof(struct ip6_hdr) + sizeof(struct mld_raopt) + \
+			 sizeof(struct icmp6_hdr))
+
+/*
+ * Subsystem lock macros.
+ * The MLD lock is only taken with MLD. Currently it is system-wide.
+ * VIMAGE: The lock could be pushed to per-VIMAGE granularity in future.
+ */
+#define	MLD_LOCK_INIT()	mtx_init(&mld_mtx, "mld_mtx", NULL, MTX_DEF)
+#define	MLD_LOCK_DESTROY()	mtx_destroy(&mld_mtx)
+#define	MLD_LOCK()		mtx_lock(&mld_mtx)
+#define	MLD_LOCK_ASSERT()	mtx_assert(&mld_mtx, MA_OWNED)
+#define	MLD_UNLOCK()		mtx_unlock(&mld_mtx)
+#define	MLD_UNLOCK_ASSERT()	mtx_assert(&mld_mtx, MA_NOTOWNED)
+
+/*
+ * Per-link MLD context.
+ */
+#define MLD_IFINFO(ifp) \
+	(((struct in6_ifextra *)(ifp)->if_afdata[AF_INET6])->mld_ifinfo)
+
+int	mld_change_state(struct in6_multi *, const int);
+struct mld_ifinfo *
+	mld_domifattach(struct ifnet *);
+void	mld_domifdetach(struct ifnet *);
+void	mld_fasttimo(void);
+void	mld_ifdetach(struct ifnet *);
+int	mld_input(struct mbuf *, int, int);
+void	mld_slowtimo(void);
+
+#ifdef SYSCTL_DECL
+SYSCTL_DECL(_net_inet6_mld);
+#endif
 
-void	mld6_init(void);
-void	mld6_input(struct mbuf *, int);
-void	mld6_start_listening(struct in6_multi *);
-void	mld6_stop_listening(struct in6_multi *);
-void	mld6_fasttimeo(void);
 #endif /* _KERNEL */
 
 #endif /* _NETINET6_MLD6_VAR_H_ */
diff --git a/sys/netinet6/raw_ip6.c b/sys/netinet6/raw_ip6.c
index 2ac95e5..c340ffd 100644
--- a/sys/netinet6/raw_ip6.c
+++ b/sys/netinet6/raw_ip6.c
@@ -128,9 +128,20 @@ extern u_long	rip_sendspace;
 extern u_long	rip_recvspace;
 
 /*
- * Hooks for multicast forwarding.
+ * Hooks for multicast routing. They all default to NULL, so leave them not
+ * initialized and rely on BSS being set to 0.
+ */
+
+/*
+ * The socket used to communicate with the multicast routing daemon.
+ */
+#ifdef VIMAGE_GLOBALS
+struct socket *ip6_mrouter;
+#endif
+
+/*
+ * The various mrouter functions.
  */
-struct socket *ip6_mrouter = NULL;
 int (*ip6_mrouter_set)(struct socket *, struct sockopt *);
 int (*ip6_mrouter_get)(struct socket *, struct sockopt *);
 int (*ip6_mrouter_done)(void);
@@ -149,6 +160,7 @@ rip6_input(struct mbuf **mp, int *offp, int proto)
 #ifdef IPSEC
 	INIT_VNET_IPSEC(curvnet);
 #endif
+	struct ifnet *ifp;
 	struct mbuf *m = *mp;
 	register struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
 	register struct inpcb *in6p;
@@ -166,6 +178,8 @@ rip6_input(struct mbuf **mp, int *offp, int proto)
 
 	init_sin6(&fromsa, m); /* general init */
 
+	ifp = m->m_pkthdr.rcvif;
+
 	INP_INFO_RLOCK(&V_ripcbinfo);
 	LIST_FOREACH(in6p, &V_ripcb, inp_list) {
 		/* XXX inp locking */
@@ -180,9 +194,17 @@ rip6_input(struct mbuf **mp, int *offp, int proto)
 		if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr) &&
 		    !IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src))
 			continue;
-		if (prison_check_ip6(in6p->inp_cred, &ip6->ip6_dst) != 0)
-			continue;
-		INP_RLOCK(in6p);
+		if (jailed(in6p->inp_cred)) {
+			/*
+			 * Allow raw socket in jail to receive multicast;
+			 * assume process had PRIV_NETINET_RAW at attach,
+			 * and fall through into normal filter path if so.
+			 */
+			if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) &&
+			    prison_check_ip6(in6p->inp_cred,
+			    &ip6->ip6_dst) != 0)
+				continue;
+		}
 		if (in6p->in6p_cksum != -1) {
 			V_rip6stat.rip6s_isum++;
 			if (in6_cksum(m, proto, *offp,
@@ -192,6 +214,31 @@ rip6_input(struct mbuf **mp, int *offp, int proto)
 				continue;
 			}
 		}
+		INP_RLOCK(in6p);
+		/*
+		 * If this raw socket has multicast state, and we
+		 * have received a multicast, check if this socket
+		 * should receive it, as multicast filtering is now
+		 * the responsibility of the transport layer.
+		 */
+		if (in6p->in6p_moptions &&
+		    IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
+			struct sockaddr_in6 mcaddr;
+			int blocked;
+
+			bzero(&mcaddr, sizeof(struct sockaddr_in6));
+			mcaddr.sin6_len = sizeof(struct sockaddr_in6);
+			mcaddr.sin6_family = AF_INET6;
+			mcaddr.sin6_addr = ip6->ip6_dst;
+
+			blocked = im6o_mc_filter(in6p->in6p_moptions, ifp,
+			    (struct sockaddr *)&mcaddr,
+			    (struct sockaddr *)&fromsa);
+			if (blocked != MCAST_PASS) {
+				IP6STAT_INC(ip6s_notmember);
+				continue;
+			}
+		}
 		if (last != NULL) {
 			struct mbuf *n = m_copy(m, 0, (int)M_COPYALL);
 
@@ -604,13 +651,13 @@ rip6_attach(struct socket *so, int proto, struct thread *td)
 static void
 rip6_detach(struct socket *so)
 {
-	INIT_VNET_INET(so->so_vnet);
+	INIT_VNET_INET6(so->so_vnet);
 	struct inpcb *inp;
 
 	inp = sotoinpcb(so);
 	KASSERT(inp != NULL, ("rip6_detach: inp == NULL"));
 
-	if (so == ip6_mrouter && ip6_mrouter_done)
+	if (so == V_ip6_mrouter && ip6_mrouter_done)
 		ip6_mrouter_done();
 	/* xxx: RSVP */
 	INP_INFO_WLOCK(&V_ripcbinfo);
diff --git a/sys/netinet6/udp6_usrreq.c b/sys/netinet6/udp6_usrreq.c
index 566cf92..5393740 100644
--- a/sys/netinet6/udp6_usrreq.c
+++ b/sys/netinet6/udp6_usrreq.c
@@ -177,6 +177,7 @@ udp6_input(struct mbuf **mp, int *offp, int proto)
 	INIT_VNET_INET(curvnet);
 	INIT_VNET_INET6(curvnet);
 	struct mbuf *m = *mp;
+	struct ifnet *ifp;
 	struct ip6_hdr *ip6;
 	struct udphdr *uh;
 	struct inpcb *inp;
@@ -184,6 +185,7 @@ udp6_input(struct mbuf **mp, int *offp, int proto)
 	int plen, ulen;
 	struct sockaddr_in6 fromsa;
 
+	ifp = m->m_pkthdr.rcvif;
 	ip6 = mtod(m, struct ip6_hdr *);
 
 	if (faithprefix_p != NULL && (*faithprefix_p)(&ip6->ip6_dst)) {
@@ -239,6 +241,7 @@ udp6_input(struct mbuf **mp, int *offp, int proto)
 	INP_INFO_RLOCK(&V_udbinfo);
 	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 		struct inpcb *last;
+		struct ip6_moptions *imo;
 
 		/*
 		 * In the event that laddr should be set to the link-local
@@ -261,12 +264,6 @@ udp6_input(struct mbuf **mp, int *offp, int proto)
 				continue;
 			if (inp->inp_lport != uh->uh_dport)
 				continue;
-			/*
-			 * XXX: Do not check source port of incoming datagram
-			 * unless inp_connect() has been called to bind the
-			 * fport part of the 4-tuple; the source could be
-			 * trying to talk to us with an ephemeral port.
-			 */
 			if (inp->inp_fport != 0 &&
 			    inp->inp_fport != uh->uh_sport)
 				continue;
@@ -282,6 +279,35 @@ udp6_input(struct mbuf **mp, int *offp, int proto)
 					continue;
 			}
 
+			INP_RLOCK(inp);
+
+			/*
+			 * Handle socket delivery policy for any-source
+			 * and source-specific multicast. [RFC3678]
+			 */
+			imo = inp->in6p_moptions;
+			if (imo && IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
+				struct sockaddr_in6	 mcaddr;
+				int			 blocked;
+
+				bzero(&mcaddr, sizeof(struct sockaddr_in6));
+				mcaddr.sin6_len = sizeof(struct sockaddr_in6);
+				mcaddr.sin6_family = AF_INET6;
+				mcaddr.sin6_addr = ip6->ip6_dst;
+
+				blocked = im6o_mc_filter(imo, ifp,
+					(struct sockaddr *)&mcaddr,
+					(struct sockaddr *)&fromsa);
+				if (blocked != MCAST_PASS) {
+					if (blocked == MCAST_NOTGMEMBER)
+						IP6STAT_INC(ip6s_notmember);
+					if (blocked == MCAST_NOTSMEMBER ||
+					    blocked == MCAST_MUTED)
+						UDPSTAT_INC(udps_filtermcast);
+					INP_RUNLOCK(inp);
+					continue;
+				}
+			}
 			if (last != NULL) {
 				struct mbuf *n;
 
@@ -397,6 +423,8 @@ udp6_input(struct mbuf **mp, int *offp, int proto)
 	return (IPPROTO_DONE);
 
 badheadlocked:
+	if (inp)
+		INP_RUNLOCK(inp);
 	INP_INFO_RUNLOCK(&V_udbinfo);
 badunlocked:
 	if (m)
diff --git a/sys/netinet6/vinet6.h b/sys/netinet6/vinet6.h
index 0920200..76bbec9 100644
--- a/sys/netinet6/vinet6.h
+++ b/sys/netinet6/vinet6.h
@@ -145,6 +145,7 @@ struct vnet_inet6 {
 	u_int32_t			_ip6_temp_preferred_lifetime;
 	u_int32_t			_ip6_temp_valid_lifetime;
 
+	struct socket *			_ip6_mrouter;
 	int				_ip6_mrouter_ver;
 	int				_pim6;
 	u_int				_mrt6debug;
@@ -153,6 +154,12 @@ struct vnet_inet6 {
 	int				_ip6_use_defzone;
 
 	struct ip6_pktopts		_ip6_opts;
+
+	struct timeval			_mld_gsrdelay;
+	LIST_HEAD(, mld_ifinfo)		_mli_head;
+	int				_interface_timers_running6;
+	int				_state_change_timers_running6;
+	int				_current_state_timers_running6;
 };
 
 /* Size guard. See sys/vimage.h. */
@@ -173,6 +180,8 @@ extern struct vnet_inet6 vnet_inet6_0;
  * Symbol translation macros
  */
 #define	V_addrsel_policytab		VNET_INET6(addrsel_policytab)
+#define	V_current_state_timers_running6	\
+	VNET_INET6(current_state_timers_running6)
 #define	V_dad_ignore_ns			VNET_INET6(dad_ignore_ns)
 #define	V_dad_init			VNET_INET6(dad_init)
 #define	V_dad_maxtry			VNET_INET6(dad_maxtry)
@@ -190,6 +199,8 @@ extern struct vnet_inet6 vnet_inet6_0;
 #define	V_in6_ifaddr			VNET_INET6(in6_ifaddr)
 #define	V_in6_maxmtu			VNET_INET6(in6_maxmtu)
 #define	V_in6_tmpaddrtimer_ch		VNET_INET6(in6_tmpaddrtimer_ch)
+#define	V_interface_timers_running6	\
+	VNET_INET6(interface_timers_running6)
 #define	V_ip6_accept_rtadv		VNET_INET6(ip6_accept_rtadv)
 #define	V_ip6_auto_flowlabel		VNET_INET6(ip6_auto_flowlabel)
 #define	V_ip6_auto_linklocal		VNET_INET6(ip6_auto_linklocal)
@@ -205,6 +216,7 @@ extern struct vnet_inet6 vnet_inet6_0;
 #define	V_ip6_maxfragpackets		VNET_INET6(ip6_maxfragpackets)
 #define	V_ip6_maxfrags			VNET_INET6(ip6_maxfrags)
 #define	V_ip6_mcast_pmtu		VNET_INET6(ip6_mcast_pmtu)
+#define	V_ip6_mrouter			VNET_INET6(ip6_mrouter)
 #define	V_ip6_mrouter_ver		VNET_INET6(ip6_mrouter_ver)
 #define	V_ip6_opts			VNET_INET6(ip6_opts)
 #define	V_ip6_prefer_tempaddr		VNET_INET6(ip6_prefer_tempaddr)
@@ -223,6 +235,8 @@ extern struct vnet_inet6 vnet_inet6_0;
 #define	V_ip6stealth			VNET_INET6(ip6stealth)
 #define	V_llinfo_nd6			VNET_INET6(llinfo_nd6)
 #define	V_mrt6debug			VNET_INET6(mrt6debug)
+#define	V_mld_gsrdelay			VNET_INET6(mld_gsrdelay)
+#define	V_mli_head			VNET_INET6(mli_head)
 #define	V_nd6_allocated			VNET_INET6(nd6_allocated)
 #define	V_nd6_debug			VNET_INET6(nd6_debug)
 #define	V_nd6_defifindex		VNET_INET6(nd6_defifindex)
@@ -256,6 +270,8 @@ extern struct vnet_inet6 vnet_inet6_0;
 #define	V_rtq_timer6			VNET_INET6(rtq_timer6)
 #define	V_rtq_toomany6			VNET_INET6(rtq_toomany6)
 #define	V_sid_default			VNET_INET6(sid_default)
+#define	V_state_change_timers_running6	\
+	VNET_INET6(state_change_timers_running6)
 #define	V_udp6_recvspace		VNET_INET6(udp6_recvspace)	
 #define	V_udp6_sendspace		VNET_INET6(udp6_sendspace)