Index: kern/kern_mbuf.c
===================================================================
--- kern/kern_mbuf.c	(revision 223932)
+++ kern/kern_mbuf.c	(working copy)
@@ -399,7 +399,8 @@
 	m->m_type = type;
 	if (flags & M_PKTHDR) {
 		m->m_data = m->m_pktdat;
-		m->m_pkthdr.rcvif = NULL;
+		m->m_pkthdr.rcvif_idx = 0;
+		m->m_pkthdr.rcvif_unique = 0;
 		m->m_pkthdr.header = NULL;
 		m->m_pkthdr.len = 0;
 		m->m_pkthdr.csum_flags = 0;
@@ -624,7 +625,8 @@
 	m->m_type = type;
 
 	if (flags & M_PKTHDR) {
-		m->m_pkthdr.rcvif = NULL;
+		m->m_pkthdr.rcvif_idx = 0;
+		m->m_pkthdr.rcvif_unique = 0;
 		m->m_pkthdr.len = 0;
 		m->m_pkthdr.header = NULL;
 		m->m_pkthdr.csum_flags = 0;
@@ -653,7 +655,8 @@
 #endif
 	m->m_data = m->m_pktdat;
 	SLIST_INIT(&m->m_pkthdr.tags);
-	m->m_pkthdr.rcvif = NULL;
+	m->m_pkthdr.rcvif_idx = 0;
+	m->m_pkthdr.rcvif_unique = 0;
 	m->m_pkthdr.header = NULL;
 	m->m_pkthdr.len = 0;
 	m->m_pkthdr.flowid = 0;
Index: kern/uipc_mbuf.c
===================================================================
--- kern/uipc_mbuf.c	(revision 223932)
+++ kern/uipc_mbuf.c	(working copy)
@@ -1135,7 +1135,8 @@
 		MGETHDR(n, wait, m0->m_type);
 		if (n == NULL)
 			return (NULL);
-		n->m_pkthdr.rcvif = m0->m_pkthdr.rcvif;
+		n->m_pkthdr.rcvif_idx = m0->m_pkthdr.rcvif_idx;
+		n->m_pkthdr.rcvif_unique = m0->m_pkthdr.rcvif_unique;
 		n->m_pkthdr.len = m0->m_pkthdr.len - len0;
 		m0->m_pkthdr.len = len0;
 		if (m->m_flags & M_EXT)
@@ -1182,7 +1183,7 @@
  * which to begin copying the data to.
  */
 struct mbuf *
-m_devget(char *buf, int totlen, int off, struct ifnet *ifp,
+m_devget(char *buf, int totlen, int off,
     void (*copy)(char *from, caddr_t to, u_int len))
 {
 	struct mbuf *m;
@@ -1209,7 +1210,6 @@
 			}
 			if (m == NULL)
 				return NULL;
-			m->m_pkthdr.rcvif = ifp;
 			m->m_pkthdr.len = totlen;
 		} else {
 			if (totlen + off >= MINCLSIZE) {
Index: netinet/tcp_input.c
===================================================================
--- netinet/tcp_input.c	(revision 223932)
+++ netinet/tcp_input.c	(working copy)
@@ -817,7 +817,7 @@
 			inp = in6_pcblookup_mbuf(&V_tcbinfo, &ip6->ip6_src,
 			    th->th_sport, &ip6->ip6_dst, th->th_dport,
 			    INPLOOKUP_WILDCARD | INPLOOKUP_WLOCKPCB,
-			    m->m_pkthdr.rcvif, m);
+			    mbuf_rcvif(m), m);
 #endif
 #if defined(INET) && defined(INET6)
 		else
@@ -826,7 +826,7 @@
 			inp = in_pcblookup_mbuf(&V_tcbinfo, ip->ip_src,
 			    th->th_sport, ip->ip_dst, th->th_dport,
 			    INPLOOKUP_WILDCARD | INPLOOKUP_WLOCKPCB,
-			    m->m_pkthdr.rcvif, m);
+			    mbuf_rcvif(m), m);
 #endif
 	}
 
@@ -1304,7 +1304,7 @@
 			if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) ||
 			    IN_MULTICAST(ntohl(ip->ip_src.s_addr)) ||
 			    ip->ip_src.s_addr == htonl(INADDR_BROADCAST) ||
-			    in_broadcast(ip->ip_dst, m->m_pkthdr.rcvif)) {
+			    in_broadcast(ip->ip_dst, mbuf_rcvif(m))) {
 				if ((s = tcp_log_addrs(&inc, th, NULL, NULL)))
 				    log(LOG_DEBUG, "%s; %s: Listen socket: "
 					"Connection attempt from/to broad- "
@@ -3060,7 +3060,7 @@
 		if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) ||
 		    IN_MULTICAST(ntohl(ip->ip_src.s_addr)) ||
 		    ip->ip_src.s_addr == htonl(INADDR_BROADCAST) ||
-		    in_broadcast(ip->ip_dst, m->m_pkthdr.rcvif))
+		    in_broadcast(ip->ip_dst, mbuf_rcvif(m)))
 			goto drop;
 	}
 #endif
Index: netinet/tcp_subr.c
===================================================================
--- netinet/tcp_subr.c	(revision 223932)
+++ netinet/tcp_subr.c	(working copy)
@@ -589,7 +589,7 @@
 #endif
 	m->m_len = tlen;
 	m->m_pkthdr.len = tlen;
-	m->m_pkthdr.rcvif = NULL;
+	m->m_pkthdr.rcvif_idx = 0;
 #ifdef MAC
 	if (inp != NULL) {
 		/*
Index: netinet/tcp_output.c
===================================================================
--- netinet/tcp_output.c	(revision 223932)
+++ netinet/tcp_output.c	(working copy)
@@ -891,7 +891,7 @@
 		m->m_len = hdrlen;
 	}
 	SOCKBUF_UNLOCK_ASSERT(&so->so_snd);
-	m->m_pkthdr.rcvif = (struct ifnet *)0;
+	m->m_pkthdr.rcvif_idx = 0;
 #ifdef MAC
 	mac_inpcb_create_mbuf(tp->t_inpcb, m);
 #endif
Index: netinet/tcp_syncache.c
===================================================================
--- netinet/tcp_syncache.c	(revision 223932)
+++ netinet/tcp_syncache.c	(working copy)
@@ -1356,7 +1356,6 @@
 	m->m_data += max_linkhdr;
 	m->m_len = tlen;
 	m->m_pkthdr.len = tlen;
-	m->m_pkthdr.rcvif = NULL;
 
 #ifdef INET6
 	if (sc->sc_inc.inc_flags & INC_ISIPV6) {
Index: netinet/ip_input.c
===================================================================
--- netinet/ip_input.c	(revision 223932)
+++ netinet/ip_input.c	(working copy)
@@ -429,7 +429,7 @@
 	}
 
 	/* 127/8 must not appear on wire - RFC1122 */
-	ifp = m->m_pkthdr.rcvif;
+	ifp = mbuf_rcvif(m);
 	if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
 	    (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
 		if ((ifp->if_flags & IFF_LOOPBACK) == 0) {
@@ -514,7 +514,7 @@
 
 	ip = mtod(m, struct ip *);
 	dchg = (odst.s_addr != ip->ip_dst.s_addr);
-	ifp = m->m_pkthdr.rcvif;
+	ifp = mbuf_rcvif(m);
 
 #ifdef IPFIREWALL_FORWARD
 	if (m->m_flags & M_FASTFWD_OURS) {
@@ -1457,7 +1457,7 @@
 	 */
 	dest.s_addr = 0;
 	if (!srcrt && V_ipsendredirects &&
-	    ia != NULL && ia->ia_ifp == m->m_pkthdr.rcvif) {
+	    ia != NULL && ia->ia_ifp == mbuf_rcvif(m)) {
 		struct sockaddr_in *sin;
 		struct rtentry *rt;
 
@@ -1665,8 +1665,8 @@
 		struct sockaddr_dl *sdp;
 		struct sockaddr_dl *sdl2 = &sdlbuf.sdl;
 
-		if (((ifp = m->m_pkthdr.rcvif)) 
-		&& ( ifp->if_index && (ifp->if_index <= V_if_index))) {
+		ifp = mbuf_rcvif(m);
+		if (ifp && (ifp->if_index && (ifp->if_index <= V_if_index))) {
 			sdp = (struct sockaddr_dl *)ifp->if_addr->ifa_addr;
 			/*
 			 * Change our mind and don't try copy.
Index: netinet/ip6.h
===================================================================
--- netinet/ip6.h	(revision 223932)
+++ netinet/ip6.h	(working copy)
@@ -293,7 +293,7 @@
     } else {								\
 	if ((m)->m_len < (off) + (hlen)) {				\
 		V_ip6stat.ip6s_tooshort++;				\
-		in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated);	\
+		in6_ifstat_inc(mbuf_rcvif(m), ifs6_in_truncated);	\
 		m_freem(m);						\
 		return ret;						\
 	}								\
Index: netinet/ip_icmp.c
===================================================================
--- netinet/ip_icmp.c	(revision 223932)
+++ netinet/ip_icmp.c	(working copy)
@@ -306,7 +306,8 @@
 	m->m_data -= sizeof(struct ip);
 	m->m_len += sizeof(struct ip);
 	m->m_pkthdr.len = m->m_len;
-	m->m_pkthdr.rcvif = n->m_pkthdr.rcvif;
+	m->m_pkthdr.rcvif_idx = n->m_pkthdr.rcvif_idx;
+	m->m_pkthdr.rcvif_unique = n->m_pkthdr.rcvif_unique;
 	nip = mtod(m, struct ip *);
 	bcopy((caddr_t)oip, (caddr_t)nip, sizeof(struct ip));
 	nip->ip_len = m->m_len;
@@ -327,6 +328,7 @@
 icmp_input(struct mbuf *m, int off)
 {
 	struct icmp *icp;
+	struct ifnet *ifp;
 	struct in_ifaddr *ia;
 	struct ip *ip = mtod(m, struct ip *);
 	struct sockaddr_in icmpsrc, icmpdst, icmpgw;
@@ -368,7 +370,7 @@
 	m->m_len += hlen;
 	m->m_data -= hlen;
 
-	if (m->m_pkthdr.rcvif && m->m_pkthdr.rcvif->if_type == IFT_FAITH) {
+	if ((ifp = mbuf_rcvif(m)) != NULL && ifp->if_type == IFT_FAITH) {
 		/*
 		 * Deliver very specific ICMP type only.
 		 */
@@ -545,7 +547,7 @@
 			icmpdst.sin_addr = ip->ip_dst;
 		}
 		ia = (struct in_ifaddr *)ifaof_ifpforaddr(
-			    (struct sockaddr *)&icmpdst, m->m_pkthdr.rcvif);
+			    (struct sockaddr *)&icmpdst, mbuf_rcvif(m));
 		if (ia == NULL)
 			break;
 		if (ia->ia_ifp == NULL) {
@@ -701,7 +703,7 @@
 	 * addresses, use the first non-broadcast address which corresponds
 	 * to the incoming interface.
 	 */
-	ifp = m->m_pkthdr.rcvif;
+	ifp = mbuf_rcvif(m);
 	if (ifp != NULL && ifp->if_flags & IFF_BROADCAST) {
 		IF_ADDR_LOCK(ifp);
 		TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
@@ -874,7 +876,7 @@
 	icp->icmp_cksum = in_cksum(m, ip->ip_len - hlen);
 	m->m_data -= hlen;
 	m->m_len += hlen;
-	m->m_pkthdr.rcvif = (struct ifnet *)0;
+	m->m_pkthdr.rcvif_idx = 0;
 #ifdef ICMPPRINTFS
 	if (icmpprintfs) {
 		char buf[4 * sizeof "123"];
Index: netinet/if_ether.c
===================================================================
--- netinet/if_ether.c	(revision 223932)
+++ netinet/if_ether.c	(working copy)
@@ -503,7 +503,7 @@
 in_arpinput(struct mbuf *m)
 {
 	struct arphdr *ah;
-	struct ifnet *ifp = m->m_pkthdr.rcvif;
+	struct ifnet *ifp = mbuf_rcvif(m);
 	struct llentry *la = NULL;
 	struct rtentry *rt;
 	struct ifaddr *ifa;
@@ -859,7 +859,7 @@
 	ah->ar_pro = htons(ETHERTYPE_IP); /* let's be sure! */
 	m->m_len = sizeof(*ah) + (2 * ah->ar_pln) + (2 * ah->ar_hln);   
 	m->m_pkthdr.len = m->m_len;   
-	m->m_pkthdr.rcvif = NULL;
+	m->m_pkthdr.rcvif_idx = 0;
 	sa.sa_family = AF_ARP;
 	sa.sa_len = 2;
 	(*ifp->if_output)(ifp, m, &sa, NULL);
Index: netinet/udp_usrreq.c
===================================================================
--- netinet/udp_usrreq.c	(revision 223932)
+++ netinet/udp_usrreq.c	(working copy)
@@ -345,7 +345,7 @@
 	struct m_tag *fwd_tag;
 #endif
 
-	ifp = m->m_pkthdr.rcvif;
+	ifp = mbuf_rcvif(m);
 	UDPSTAT_INC(udps_ipackets);
 
 	/*
Index: netinet/raw_ip.c
===================================================================
--- netinet/raw_ip.c	(revision 223932)
+++ netinet/raw_ip.c	(working copy)
@@ -288,7 +288,7 @@
 	ripsrc.sin_addr = ip->ip_src;
 	last = NULL;
 
-	ifp = m->m_pkthdr.rcvif;
+	ifp = mbuf_rcvif(m);
 
 	hash = INP_PCBHASH_RAW(proto, ip->ip_src.s_addr,
 	    ip->ip_dst.s_addr, V_ripcbinfo.ipi_hashmask);
Index: netinet/ip_output.c
===================================================================
--- netinet/ip_output.c	(revision 223932)
+++ netinet/ip_output.c	(working copy)
@@ -517,8 +517,8 @@
 		/* If destination is now ourself drop to ip_input(). */
 		if (in_localip(ip->ip_dst)) {
 			m->m_flags |= M_FASTFWD_OURS;
-			if (m->m_pkthdr.rcvif == NULL)
-				m->m_pkthdr.rcvif = V_loif;
+			if (mbuf_rcvif(m) == NULL)
+				m_set_rcvif(m, V_loif);
 			if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
 				m->m_pkthdr.csum_flags |=
 				    CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
@@ -821,7 +821,7 @@
 			goto done;
 		}
 		m->m_pkthdr.len = mhlen + len;
-		m->m_pkthdr.rcvif = NULL;
+		m->m_pkthdr.rcvif_idx = 0;
 #ifdef MAC
 		mac_netinet_fragment(m0, m);
 #endif
Index: netinet/ip_options.c
===================================================================
--- netinet/ip_options.c	(revision 223932)
+++ netinet/ip_options.c	(working copy)
@@ -323,7 +323,7 @@
 				}
 				ipaddr.sin_addr = dst;
 				ia = (INA)ifaof_ifpforaddr((SA)&ipaddr,
-							    m->m_pkthdr.rcvif);
+							    mbuf_rcvif(m));
 				if (ia == NULL)
 					continue;
 				(void)memcpy(sin, &IA_SIN(ia)->sin_addr,
@@ -507,7 +507,7 @@
 			return (m);
 		}
 		M_MOVE_PKTHDR(n, m);
-		n->m_pkthdr.rcvif = NULL;
+		n->m_pkthdr.rcvif_idx = 0;
 		n->m_pkthdr.len += optlen;
 		m->m_len -= sizeof(struct ip);
 		m->m_data += sizeof(struct ip);
Index: netinet/ip_fastfwd.c
===================================================================
--- netinet/ip_fastfwd.c	(revision 223932)
+++ netinet/ip_fastfwd.c	(working copy)
@@ -316,8 +316,9 @@
 	 * let ip_input handle it.  We play safe here and let ip_input
 	 * deal with it until it is proven that we can directly drop it.
 	 */
+	ifp = mbuf_rcvif(m);
 	if ((m->m_flags & (M_BCAST|M_MCAST)) ||
-	    (m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) ||
+	    (ifp->if_flags & IFF_LOOPBACK) ||
 	    ntohl(ip->ip_src.s_addr) == (u_long)INADDR_BROADCAST ||
 	    ntohl(ip->ip_dst.s_addr) == (u_long)INADDR_BROADCAST ||
 	    IN_MULTICAST(ntohl(ip->ip_src.s_addr)) ||
@@ -354,8 +355,7 @@
 	if (!PFIL_HOOKED(&V_inet_pfil_hook))
 		goto passin;
 
-	if (pfil_run_hooks(
-	    &V_inet_pfil_hook, &m, m->m_pkthdr.rcvif, PFIL_IN, NULL) ||
+	if (pfil_run_hooks(&V_inet_pfil_hook, &m, ifp, PFIL_IN, NULL) ||
 	    m == NULL)
 		goto drop;
 
Index: netinet/igmp.c
===================================================================
--- netinet/igmp.c	(revision 223932)
+++ netinet/igmp.c	(working copy)
@@ -1435,7 +1435,7 @@
 
 	CTR3(KTR_IGMPV3, "%s: called w/mbuf (%p,%d)", __func__, m, off);
 
-	ifp = m->m_pkthdr.rcvif;
+	ifp = mbuf_rcvif(m);
 
 	IGMPSTAT_INC(igps_rcv_total);
 
@@ -3454,7 +3454,7 @@
 
 	igmp_scrub_context(m0);
 	m->m_flags &= ~(M_PROTOFLAGS);
-	m0->m_pkthdr.rcvif = V_loif;
+	m_set_rcvif(m0, V_loif);
 #ifdef MAC
 	mac_netinet_igmp_send(ifp, m0);
 #endif
Index: netgraph/ng_eiface.c
===================================================================
--- netgraph/ng_eiface.c	(revision 223932)
+++ netgraph/ng_eiface.c	(working copy)
@@ -596,7 +596,7 @@
 	}
 
 	/* Note receiving interface */
-	m->m_pkthdr.rcvif = ifp;
+	m_set_rcvif(m, ifp);
 
 	/* Update interface stats */
 	ifp->if_ipackets++;
Index: netgraph/ng_tty.c
===================================================================
--- netgraph/ng_tty.c	(revision 223932)
+++ netgraph/ng_tty.c	(working copy)
@@ -425,7 +425,6 @@
 			    "%s: can't get mbuf\n", NG_NODE_NAME(node));
 		return (0);
 	}
-	m->m_pkthdr.rcvif = NULL;
 
 	for (mb = m; mb != NULL; mb = mb->m_next) {
 		length = min(M_TRAILINGSPACE(mb), len - total);
@@ -484,7 +483,6 @@
 			return (ENOBUFS);
 		}
 		m->m_len = m->m_pkthdr.len = 0;
-		m->m_pkthdr.rcvif = NULL;
 		sc->m = m;
 	}
 
Index: netgraph/ng_sppp.c
===================================================================
--- netgraph/ng_sppp.c	(revision 223932)
+++ netgraph/ng_sppp.c	(working copy)
@@ -366,7 +366,7 @@
 	SP2IFP(pp)->if_ipackets++;
 
 	/* Note receiving interface */
-	m->m_pkthdr.rcvif = SP2IFP(pp);
+	m_set_rcvif(m, SP2IFP(pp));
 
 	/* Berkeley packet filter */
 	BPF_MTAP (SP2IFP(pp), m);
Index: netgraph/ng_socket.c
===================================================================
--- netgraph/ng_socket.c	(revision 223932)
+++ netgraph/ng_socket.c	(working copy)
@@ -934,7 +934,7 @@
 
 	/* Copy the message itself into an mbuf chain. */
 	m = m_devget((caddr_t)msg, sizeof(struct ng_mesg) + msg->header.arglen,
-	    0, NULL, NULL);
+	    0, NULL);
 
 	/*
 	 * Here we free the message. We need to do that
Index: netgraph/ng_bridge.c
===================================================================
--- netgraph/ng_bridge.c	(revision 223932)
+++ netgraph/ng_bridge.c	(working copy)
@@ -599,7 +599,7 @@
 
 				/* Log the problem */
 				if (priv->conf.debugLevel >= 2) {
-					struct ifnet *ifp = m->m_pkthdr.rcvif;
+					struct ifnet *ifp = mbuf_rcvif(m);
 					char suffix[32];
 
 					if (ifp != NULL)
Index: netgraph/ng_ether.c
===================================================================
--- netgraph/ng_ether.c	(revision 223932)
+++ netgraph/ng_ether.c	(working copy)
@@ -679,7 +679,7 @@
 	    (m = m_pullup(m, sizeof(struct ether_header))) == NULL)
 		return (ENOBUFS);
 
-	m->m_pkthdr.rcvif = ifp;
+	m_set_rcvif(m, ifp);
 
 	/* Pass the packet to the bridge, it may come back to us */
 	if (ifp->if_bridge) {
Index: netgraph/ng_async.c
===================================================================
--- netgraph/ng_async.c	(revision 223932)
+++ netgraph/ng_async.c	(working copy)
@@ -417,7 +417,7 @@
 	}
 	NGI_GET_M(item, m);
 
-	rcvif = m->m_pkthdr.rcvif;
+	rcvif = mbuf_rcvif(m);
 
 	/* Get ACCM; special case LCP frames, which use full ACCM */
 	accm = sc->cfg.accm;
@@ -475,10 +475,11 @@
 	sc->abuf[alen++] = PPP_FLAG;
 
 	/* Put frame in an mbuf and ship it off */
-	if (!(m = m_devget(sc->abuf, alen, 0, rcvif, NULL))) {
+	if (!(m = m_devget(sc->abuf, alen, 0, NULL))) {
 		NG_FREE_ITEM(item);
 		error = ENOBUFS;
 	} else {
+		m_set_rcvif(m, rcvif);
 		NG_FWD_NEW_DATA(error, item, sc->async, m);
 	}
 	return (error);
@@ -501,7 +502,7 @@
 		return (error);
 	}
 	NGI_GET_M(item, m);
-	rcvif = m->m_pkthdr.rcvif;
+	rcvif = mbuf_rcvif(m);
 	while (m) {
 		struct mbuf *n;
 
@@ -540,7 +541,8 @@
 
 				/* OK, ship it out */
 				if ((n = m_devget(sc->sbuf + skip,
-					   sc->slen - skip, 0, rcvif, NULL))) {
+					   sc->slen - skip, 0, NULL))) {
+					m_set_rcvif(n, rcvif);
 					if (item) { /* sets NULL -> item */
 						NG_FWD_NEW_DATA(error, item,
 							sc->sync, n);
Index: netgraph/ng_vjc.c
===================================================================
--- netgraph/ng_vjc.c	(revision 223932)
+++ netgraph/ng_vjc.c	(working copy)
@@ -482,7 +482,6 @@
 			return (ENOBUFS);
 		}
 		hm->m_len = 0;
-		hm->m_pkthdr.rcvif = NULL;
 		if (hlen > MHLEN) {		/* unlikely, but can happen */
 			MCLGET(hm, M_DONTWAIT);
 			if ((hm->m_flags & M_EXT) == 0) {
Index: netgraph/ng_fec.c
===================================================================
--- netgraph/ng_fec.c	(revision 223932)
+++ netgraph/ng_fec.c	(working copy)
@@ -864,7 +864,7 @@
 	struct ng_node		*node;
 	struct ng_fec_private	*priv;
 	struct ng_fec_bundle	*b;
-	struct ifnet		*bifp;
+	struct ifnet		*mifp, *bifp;
 	struct ng_fec_portlist	*p;
 
 	/* Sanity check */
@@ -880,9 +880,10 @@
 	priv = NG_NODE_PRIVATE(node);
 	b = &priv->fec_bundle;
 	bifp = priv->ifp;
+	mifp = mbuf_rcvif(m0);
 
 	TAILQ_FOREACH(p, &b->ng_fec_ports, fec_list) {
-		if (p->fec_if == m0->m_pkthdr.rcvif)
+		if (p->fec_if == mifp)
 			break;
 	}
 
@@ -897,10 +898,10 @@
 	 * otherwise would not. BPF tapping of our own aggregate
 	 * interface will occur once we call ether_input().
 	 */
-	BPF_MTAP(m0->m_pkthdr.rcvif, m0);
+	BPF_MTAP(mifp, m0);
 
 	/* Convince the system that this is our frame. */
-	m0->m_pkthdr.rcvif = bifp;
+	m_set_rcvif(m0, bifp);
 
 	/*
 	 * Count bytes on an individual interface in a bundle.
Index: netgraph/ng_cisco.c
===================================================================
--- netgraph/ng_cisco.c	(revision 223932)
+++ netgraph/ng_cisco.c	(working copy)
@@ -613,7 +613,6 @@
 
 	t = time.tv_sec * 1000 + time.tv_usec / 1000;
 	m->m_pkthdr.len = m->m_len = CISCO_HEADER_LEN + CISCO_PACKET_LEN;
-	m->m_pkthdr.rcvif = 0;
 
 	h = mtod(m, struct cisco_header *);
 	h->address = CISCO_MULTICAST;
Index: netgraph/ng_iface.c
===================================================================
--- netgraph/ng_iface.c	(revision 223932)
+++ netgraph/ng_iface.c	(working copy)
@@ -743,7 +743,7 @@
 	ifp->if_ibytes += m->m_pkthdr.len;
 
 	/* Note receiving interface */
-	m->m_pkthdr.rcvif = ifp;
+	m_set_rcvif(m, ifp);
 
 	/* Berkeley packet filter */
 	ng_iface_bpftap(ifp, m, iffam->family);
Index: netgraph/netflow/ng_netflow.c
===================================================================
--- netgraph/netflow/ng_netflow.c	(revision 223932)
+++ netgraph/netflow/ng_netflow.c	(working copy)
@@ -894,8 +894,8 @@
 	/* Determine packet input interface. Prefer configured. */
 	src_if_index = 0;
 	if (hook == iface->out || iface->info.ifinfo_index == 0) {
-		if (m->m_pkthdr.rcvif != NULL)
-			src_if_index = m->m_pkthdr.rcvif->if_index;
+		if (m->m_pkthdr.rcvif_idx != 0)
+			src_if_index = m->m_pkthdr.rcvif_idx;
 	} else
 		src_if_index = iface->info.ifinfo_index;
 	
Index: netgraph/ng_lmi.c
===================================================================
--- netgraph/ng_lmi.c	(revision 223932)
+++ netgraph/ng_lmi.c	(working copy)
@@ -322,7 +322,6 @@
 		log(LOG_ERR, "nglmi: unable to start up LMI processing\n");
 		return;
 	}
-	m->m_pkthdr.rcvif = NULL;
 
 	/* Attach a tag to packet, marking it of link level state priority, so
 	 * that device driver would put it in the beginning of queue */
Index: netgraph/ng_l2tp.c
===================================================================
--- netgraph/ng_l2tp.c	(revision 223932)
+++ netgraph/ng_l2tp.c	(working copy)
@@ -1527,7 +1527,6 @@
 			return (ENOBUFS);
 		}
 		m->m_len = m->m_pkthdr.len = 12;
-		m->m_pkthdr.rcvif = NULL;
 		priv->stats.xmitZLBs++;
 	} else {
 
Index: netgraph/ng_pptpgre.c
===================================================================
--- netgraph/ng_pptpgre.c	(revision 223932)
+++ netgraph/ng_pptpgre.c	(working copy)
@@ -604,7 +604,6 @@
 			ERROUT(ENOBUFS);
 		}
 		m->m_len = m->m_pkthdr.len = grelen;
-		m->m_pkthdr.rcvif = NULL;
 	} else {
 		M_PREPEND(m, grelen, M_DONTWAIT);
 		if (m == NULL || (m->m_len < grelen
Index: netgraph/ng_pppoe.c
===================================================================
--- netgraph/ng_pppoe.c	(revision 223932)
+++ netgraph/ng_pppoe.c	(working copy)
@@ -806,7 +806,6 @@
 				free(neg, M_NETGRAPH_PPPOE);
 				LEAVE(ENOBUFS);
 			}
-			neg->m->m_pkthdr.rcvif = NULL;
 			sp->neg = neg;
 			ng_callout_init(&neg->handle);
 			neg->m->m_len = sizeof(struct pppoe_full_hdr);
@@ -1746,7 +1745,6 @@
 				int	msglen = strlen(SIGNOFF);
 				int	error = 0;
 
-				m->m_pkthdr.rcvif = NULL;
 				m->m_pkthdr.len = m->m_len = sizeof(*wh);
 				wh = mtod(m, struct pppoe_full_hdr *);
 				bcopy(&sp->pkt_hdr, wh, sizeof(*wh));
Index: dev/e1000/if_igb.c
===================================================================
--- dev/e1000/if_igb.c	(revision 223932)
+++ dev/e1000/if_igb.c	(working copy)
@@ -4542,7 +4542,7 @@
 		}
 
 		if (eop) {
-			rxr->fmp->m_pkthdr.rcvif = ifp;
+			m_set_rcvif(rxr->fmp, ifp);
 			ifp->if_ipackets++;
 			rxr->rx_packets++;
 			/* capture data for AIM */
Index: dev/e1000/if_lem.c
===================================================================
--- dev/e1000/if_lem.c	(revision 223932)
+++ dev/e1000/if_lem.c	(working copy)
@@ -3497,7 +3497,7 @@
 			}
 
 			if (eop) {
-				adapter->fmp->m_pkthdr.rcvif = ifp;
+				m_set_rcvif(adapter->fmp, ifp);
 				ifp->if_ipackets++;
 				lem_receive_checksum(adapter, current_desc,
 				    adapter->fmp);
Index: dev/e1000/if_em.c
===================================================================
--- dev/e1000/if_em.c	(revision 223932)
+++ dev/e1000/if_em.c	(working copy)
@@ -4299,7 +4299,7 @@
 		if (eop) {
 			--count;
 			sendmp = rxr->fmp;
-			sendmp->m_pkthdr.rcvif = ifp;
+			m_set_rcvif(sendmp, ifp);
 			ifp->if_ipackets++;
 			em_receive_checksum(cur, sendmp);
 #ifndef __NO_STRICT_ALIGNMENT
Index: dev/age/if_age.c
===================================================================
--- dev/age/if_age.c	(revision 223932)
+++ dev/age/if_age.c	(working copy)
@@ -2347,7 +2347,7 @@
 
 			m = sc->age_cdata.age_rxhead;
 			m->m_flags |= M_PKTHDR;
-			m->m_pkthdr.rcvif = ifp;
+			m_set_rcvif(m, ifp);
 			m->m_pkthdr.len = sc->age_cdata.age_rxlen;
 			/* Set the first mbuf length. */
 			m->m_len = sc->age_cdata.age_rxlen - pktlen;
Index: dev/ae/if_ae.c
===================================================================
--- dev/ae/if_ae.c	(revision 223932)
+++ dev/ae/if_ae.c	(working copy)
@@ -1897,9 +1897,10 @@
 		return (EIO);
 	}
 
-	m = m_devget(&rxd->data[0], size, ETHER_ALIGN, ifp, NULL);
+	m = m_devget(&rxd->data[0], size, ETHER_ALIGN, NULL);
 	if (m == NULL)
 		return (ENOBUFS);
+	m_set_rcvif(m, ifp);
 
 	if ((ifp->if_capenable & IFCAP_VLAN_HWTAGGING) != 0 &&
 	    (flags & AE_RXD_HAS_VLAN) != 0) {
Index: dev/an/if_an.c
===================================================================
--- dev/an/if_an.c	(revision 223932)
+++ dev/an/if_an.c	(working copy)
@@ -957,7 +957,7 @@
 				ifp->if_ierrors++;
 				return;
 			}
-			m->m_pkthdr.rcvif = ifp;
+			m_set_rcvif(m, ifp);
 			/* Read Ethernet encapsulated packet */
 
 #ifdef ANCACHE
@@ -1048,7 +1048,7 @@
 					ifp->if_ierrors++;
 					return;
 				}
-				m->m_pkthdr.rcvif = ifp;
+				m_set_rcvif(m, ifp);
 				/* Read Ethernet encapsulated packet */
 
 				/*
Index: dev/alc/if_alc.c
===================================================================
--- dev/alc/if_alc.c	(revision 223932)
+++ dev/alc/if_alc.c	(working copy)
@@ -3020,7 +3020,7 @@
 				}
 			} else
 				m->m_len = m->m_pkthdr.len;
-			m->m_pkthdr.rcvif = ifp;
+			m_set_rcvif(m, ifp);
 			/*
 			 * Due to hardware bugs, Rx checksum offloading
 			 * was intentionally disabled.
Index: dev/ale/if_ale.c
===================================================================
--- dev/ale/if_ale.c	(revision 223932)
+++ dev/ale/if_ale.c	(working copy)
@@ -2566,12 +2566,13 @@
 		 * on these low-end consumer ethernet controller.
 		 */
 		m = m_devget((char *)(rs + 1), length - ETHER_CRC_LEN,
-		    ETHER_ALIGN, ifp, NULL);
+		    ETHER_ALIGN, NULL);
 		if (m == NULL) {
 			ifp->if_iqdrops++;
 			ale_rx_update_page(sc, &rx_page, length, &prod);
 			continue;
 		}
+		m_set_rcvif(m, ifp);
 		if ((ifp->if_capenable & IFCAP_RXCSUM) != 0 &&
 		    (status & ALE_RD_IPV4) != 0)
 			ale_rxcsum(sc, m, status);
Index: dev/ath/if_ath.c
===================================================================
--- dev/ath/if_ath.c	(revision 223932)
+++ dev/ath/if_ath.c	(working copy)
@@ -3588,7 +3588,7 @@
 				sc->sc_stats.ast_rx_toobig++;
 				m_freem(sc->sc_rxpending);
 			}
-			m->m_pkthdr.rcvif = ifp;
+			m_set_rcvif(m, ifp);
 			m->m_pkthdr.len = len;
 			sc->sc_rxpending = m;
 			goto rx_next;
@@ -3607,7 +3607,7 @@
 			 * Normal single-descriptor receive; setup
 			 * the rcvif and packet length.
 			 */
-			m->m_pkthdr.rcvif = ifp;
+			m_set_rcvif(m, ifp);
 			m->m_pkthdr.len = len;
 		}
 
Index: net/if.c
===================================================================
--- net/if.c	(revision 223932)
+++ net/if.c	(working copy)
@@ -186,12 +186,14 @@
 VNET_DEFINE(struct ifgrouphead, ifg_head);
 
 static VNET_DEFINE(int, if_indexlim) = 8;
+static VNET_DEFINE(u_int, if_unique) = 1;
 
 /* Table of ifnet by index. */
 VNET_DEFINE(struct ifindex_entry *, ifindex_table);
 
 #define	V_if_indexlim		VNET(if_indexlim)
 #define	V_ifindex_table		VNET(ifindex_table)
+#define V_if_unique		VNET(if_unique)
 
 /*
  * The global network interface list (V_ifnet) and related state (such as
@@ -257,6 +259,58 @@
 	return (ifp);
 }
 
+struct ifnet *
+mbuf_rcvif(struct mbuf *m)
+{
+	struct ifnet *ifp;
+
+	M_ASSERTPKTHDR(m);
+
+	if (m->m_pkthdr.rcvif_idx == 0)
+		return (NULL);
+
+	/*
+	 * XXXGL: since we do not put a ref on ifnet, there
+	 * is no reason to use locking. 
+	 */
+	ifp = ifnet_byindex_locked(m->m_pkthdr.rcvif_idx);
+	if (ifp == NULL)
+		return (NULL);
+	if (ifp->if_unique != m->m_pkthdr.rcvif_unique)
+		return (NULL);
+
+	return (ifp);
+}
+
+struct ifnet *
+mbuf_rcvif_ref(struct mbuf *m)
+{
+	struct ifnet *ifp;
+
+	M_ASSERTPKTHDR(m);
+
+	if (m->m_pkthdr.rcvif_idx == 0)
+		return (NULL);
+
+	ifp = ifnet_byindex_ref(m->m_pkthdr.rcvif_idx);
+	if (ifp == NULL)
+		return (NULL);
+	if (ifp->if_unique != m->m_pkthdr.rcvif_unique) {
+		if_rele(ifp);
+		return (NULL);
+	}
+
+	return (ifp);
+}
+
+void 
+m_set_rcvif(struct mbuf *m, struct ifnet *ifp)
+{
+
+	m->m_pkthdr.rcvif_idx = ifp->if_index;                   
+	m->m_pkthdr.rcvif_unique = ifp->if_unique;                       
+}
+
 /*
  * Allocate an ifindex array entry; return 0 on success or an error on
  * failure.
@@ -435,6 +489,7 @@
 		return (NULL);
 	}
 	ifnet_setbyindex_locked(idx, IFNET_HOLD);
+	ifp->if_unique = V_if_unique++;
 	IFNET_WUNLOCK();
 	ifp->if_index = idx;
 	ifp->if_type = type;
Index: net/if_disc.c
===================================================================
--- net/if_disc.c	(revision 223932)
+++ net/if_disc.c	(working copy)
@@ -172,7 +172,7 @@
 		u_int af = dst->sa_family;
 		bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m);
 	}
-	m->m_pkthdr.rcvif = ifp;
+	m_set_rcvif(m, ifp);
 
 	ifp->if_opackets++;
 	ifp->if_obytes += m->m_pkthdr.len;
Index: net/netisr.c
===================================================================
--- net/netisr.c	(revision 223932)
+++ net/netisr.c	(working copy)
@@ -744,7 +744,7 @@
 	    ("%s: invalid policy %u for %s", __func__, npp->np_policy,
 	    npp->np_name));
 
-	ifp = m->m_pkthdr.rcvif;
+	ifp = mbuf_rcvif(m);
 	if (ifp != NULL)
 		*cpuidp = nws_array[(ifp->if_index + source) % nws_count];
 	else
@@ -795,14 +795,17 @@
 	nwsp->nws_pendingbits &= ~(1 << proto);
 	NWS_UNLOCK(nwsp);
 	while ((m = local_npw.nw_head) != NULL) {
+		struct ifnet *ifp;
+
 		local_npw.nw_head = m->m_nextpkt;
 		m->m_nextpkt = NULL;
 		if (local_npw.nw_head == NULL)
 			local_npw.nw_tail = NULL;
 		local_npw.nw_len--;
-		VNET_ASSERT(m->m_pkthdr.rcvif != NULL,
-		    ("%s:%d rcvif == NULL: m=%p", __func__, __LINE__, m));
-		CURVNET_SET(m->m_pkthdr.rcvif->if_vnet);
+		ifp = mbuf_rcvif(m);
+		VNET_ASSERT(ifp != NULL,
+		    ("%s:%d no rcvif: m=%p", __func__, __LINE__, m));
+		CURVNET_SET(ifp->if_vnet);
 		netisr_proto[proto].np_handler(m);
 		CURVNET_RESTORE();
 	}
Index: net/bpf.c
===================================================================
--- net/bpf.c	(revision 223932)
+++ net/bpf.c	(working copy)
@@ -500,7 +500,7 @@
 #endif
 		    (len <= MJUM9BYTES ? MJUM9BYTES : MJUM16BYTES));
 	m->m_pkthdr.len = m->m_len = len;
-	m->m_pkthdr.rcvif = NULL;
+	m->m_pkthdr.rcvif_idx = 0;
 	*mp = m;
 
 	if (m->m_len < hlen) {
@@ -924,7 +924,7 @@
 	if (d->bd_feedback) {
 		mc = m_dup(m, M_DONTWAIT);
 		if (mc != NULL)
-			mc->m_pkthdr.rcvif = ifp;
+			m_set_rcvif(mc, ifp);
 		/* Set M_PROMISC for outgoing packets to be discarded. */
 		if (d->bd_direction == BPF_D_INOUT)
 			m->m_flags |= M_PROMISC;
@@ -1870,7 +1870,7 @@
 	int gottime;
 
 	/* Skip outgoing duplicate packets. */
-	if ((m->m_flags & M_PROMISC) != 0 && m->m_pkthdr.rcvif == NULL) {
+	if ((m->m_flags & M_PROMISC) != 0 && m->m_pkthdr.rcvif_idx == 0) {
 		m->m_flags &= ~M_PROMISC;
 		return;
 	}
@@ -1880,7 +1880,8 @@
 	gottime = BPF_TSTAMP_NONE;
 	BPFIF_LOCK(bp);
 	LIST_FOREACH(d, &bp->bif_dlist, bd_next) {
-		if (BPF_CHECK_DIRECTION(d, m->m_pkthdr.rcvif, bp->bif_ifp))
+		if (BPF_CHECK_DIRECTION(d, m->m_pkthdr.rcvif_idx,
+		    bp->bif_ifp->if_index))
 			continue;
 		BPFD_LOCK(d);
 		++d->bd_rcount;
@@ -1921,7 +1922,7 @@
 	int gottime;
 
 	/* Skip outgoing duplicate packets. */
-	if ((m->m_flags & M_PROMISC) != 0 && m->m_pkthdr.rcvif == NULL) {
+	if ((m->m_flags & M_PROMISC) != 0 && m->m_pkthdr.rcvif_idx == 0) {
 		m->m_flags &= ~M_PROMISC;
 		return;
 	}
@@ -1940,7 +1941,8 @@
 	gottime = BPF_TSTAMP_NONE;
 	BPFIF_LOCK(bp);
 	LIST_FOREACH(d, &bp->bif_dlist, bd_next) {
-		if (BPF_CHECK_DIRECTION(d, m->m_pkthdr.rcvif, bp->bif_ifp))
+		if (BPF_CHECK_DIRECTION(d, m->m_pkthdr.rcvif_idx,
+		    bp->bif_ifp->if_index))
 			continue;
 		BPFD_LOCK(d);
 		++d->bd_rcount;
Index: net/if_stf.c
===================================================================
--- net/if_stf.c	(revision 223932)
+++ net/if_stf.c	(working copy)
@@ -726,7 +726,7 @@
 	 * for source, perform ingress filter as well.
 	 */
 	if (stf_checkaddr4(sc, &ip->ip_dst, NULL) < 0 ||
-	    stf_checkaddr4(sc, &ip->ip_src, m->m_pkthdr.rcvif) < 0) {
+	    stf_checkaddr4(sc, &ip->ip_src, mbuf_rcvif(m)) < 0) {
 		m_freem(m);
 		return;
 	}
@@ -746,7 +746,7 @@
 	 * for source, perform ingress filter as well.
 	 */
 	if (stf_checkaddr6(sc, &ip6->ip6_dst, NULL) < 0 ||
-	    stf_checkaddr6(sc, &ip6->ip6_src, m->m_pkthdr.rcvif) < 0) {
+	    stf_checkaddr6(sc, &ip6->ip6_src, mbuf_rcvif(m)) < 0) {
 		m_freem(m);
 		return;
 	}
@@ -759,7 +759,7 @@
 	ip6->ip6_flow &= ~htonl(0xff << 20);
 	ip6->ip6_flow |= htonl((u_int32_t)itos << 20);
 
-	m->m_pkthdr.rcvif = ifp;
+	m_set_rcvif(m, ifp);
 	
 	if (bpf_peers_present(ifp->if_bpf)) {
 		/*
Index: net/if_atmsubr.c
===================================================================
--- net/if_atmsubr.c	(revision 223932)
+++ net/if_atmsubr.c	(working copy)
@@ -279,7 +279,7 @@
 		npcb = rxhand;
 		npcb->npcb_inq++;	/* count # in queue */
 		isr = NETISR_NATM;
-		m->m_pkthdr.rcvif = rxhand; /* XXX: overload */
+		m_set_rcvif(m, rxhand); /* XXX: overload */
 		NATM_UNLOCK();
 #else
 		printf("atm_input: NATM detected but not "
Index: net/if_ef.c
===================================================================
--- net/if_ef.c	(revision 223932)
+++ net/if_ef.c	(working copy)
@@ -364,7 +364,7 @@
 	if ((eifp->if_flags & IFF_UP) == 0)
 		return EPROTONOSUPPORT;
 	eifp->if_ibytes += m->m_pkthdr.len + sizeof (*eh);
-	m->m_pkthdr.rcvif = eifp;
+	m_set_rcvif(m, eifp);
 
 	BPF_MTAP2(eifp, eh, ETHER_HDR_LEN, m);
 	/*
Index: net/if_bridge.c
===================================================================
--- net/if_bridge.c	(revision 223932)
+++ net/if_bridge.c	(working copy)
@@ -2009,7 +2009,7 @@
 	uint8_t *dst;
 	int error;
 
-	src_if = m->m_pkthdr.rcvif;
+	src_if = mbuf_rcvif(m);
 	ifp = sc->sc_ifp;
 
 	ifp->if_ipackets++;
@@ -2171,7 +2171,7 @@
 	 * packet counters associated with this interface.
 	 */
 	if ((bifp->if_flags & IFF_MONITOR) != 0) {
-		m->m_pkthdr.rcvif  = bifp;
+		m_set_rcvif(m, bifp);
 		ETHER_BPF_MTAP(bifp, m);
 		bifp->if_ipackets++;
 		bifp->if_ibytes += m->m_pkthdr.len;
@@ -2235,7 +2235,7 @@
 			mc2 = m_copyup(mc2, i, ETHER_ALIGN);
 		}
 		if (mc2 != NULL) {
-			mc2->m_pkthdr.rcvif = bifp;
+			m_set_rcvif(mc2, bifp);
 			(*bifp->if_input)(bifp, mc2);
 		}
 
@@ -2298,7 +2298,7 @@
 				return (NULL);				\
 			}						\
 		}							\
-		m->m_pkthdr.rcvif = iface;				\
+		m_set_rcvif(m, iface);					\
 		BRIDGE_UNLOCK(sc);					\
 		return (m);						\
 	}								\
@@ -3356,7 +3356,10 @@
 {
 	struct mbuf *m = *mp;
 	struct ip6_hdr *ip6;
+	struct ifnet *inifp;
 
+	inifp = mbuf_rcvif(m);
+
 	/*
 	 * If the IPv6 header is not aligned, slurp it up into a new
 	 * mbuf with space for link headers, in the event we forward
@@ -3364,7 +3367,6 @@
 	 * IPv6 header is in the first mbuf of the chain.
 	 */
 	if (IP6_HDR_ALIGNED_P(mtod(m, caddr_t)) == 0) {
-		struct ifnet *inifp = m->m_pkthdr.rcvif;
 		if ((m = m_copyup(m, sizeof(struct ip6_hdr),
 			    (max_linkhdr + 3) & ~3)) == NULL) {
 			/* XXXJRT new stat, please */
@@ -3373,7 +3375,6 @@
 			goto bad;
 		}
 	} else if (__predict_false(m->m_len < sizeof(struct ip6_hdr))) {
-		struct ifnet *inifp = m->m_pkthdr.rcvif;
 		if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) {
 			V_ip6stat.ip6s_toosmall++;
 			in6_ifstat_inc(inifp, ifs6_in_hdrerr);
@@ -3385,7 +3386,7 @@
 
 	if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) {
 		V_ip6stat.ip6s_badvers++;
-		in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr);
+		in6_ifstat_inc(inifp, ifs6_in_hdrerr);
 		goto bad;
 	}
 
Index: net/bridgestp.c
===================================================================
--- net/bridgestp.c	(revision 223932)
+++ net/bridgestp.c	(working copy)
@@ -238,7 +238,7 @@
 	if (m == NULL)
 		return;
 
-	m->m_pkthdr.rcvif = ifp;
+	m_set_rcvif(m, ifp);
 	m->m_pkthdr.len = sizeof(*eh) + sizeof(bpdu);
 	m->m_len = m->m_pkthdr.len;
 
@@ -382,7 +382,7 @@
 		default:
 			panic("not implemented");
 	}
-	m->m_pkthdr.rcvif = ifp;
+	m_set_rcvif(m, ifp);
 	m->m_len = m->m_pkthdr.len;
 
 	bp->bp_txcount++;
Index: net/if_fwsubr.c
===================================================================
--- net/if_fwsubr.c	(revision 223932)
+++ net/if_fwsubr.c	(working copy)
@@ -534,16 +534,16 @@
 		m_adj(m, sizeof(uint32_t));
 	}
 
-	if (m->m_pkthdr.rcvif == NULL) {
+	if (mbuf_rcvif(m) == NULL) {
 		if_printf(ifp, "discard frame w/o interface pointer\n");
 		ifp->if_ierrors++;
 		m_freem(m);
 		return;
 	}
 #ifdef DIAGNOSTIC
-	if (m->m_pkthdr.rcvif != ifp) {
-		if_printf(ifp, "Warning, frame marked as received on %s\n",
-			m->m_pkthdr.rcvif->if_xname);
+	if (mbuf_rcvif(m) != ifp) {
+		if_printf(ifp, "Warning, frame marked as received on %u\n",
+			m->m_pkthdr.rcvif_idx);
 	}
 #endif
 
Index: net/if_vlan.c
===================================================================
--- net/if_vlan.c	(revision 223932)
+++ net/if_vlan.c	(working copy)
@@ -1162,7 +1162,7 @@
 	}
 	TRUNK_RUNLOCK(trunk);
 
-	m->m_pkthdr.rcvif = ifv->ifv_ifp;
+	m_set_rcvif(m, ifv->ifv_ifp);
 	ifv->ifv_ifp->if_ipackets++;
 
 	/* Pass it back through the parent's input routine. */
Index: net/if_ethersubr.c
===================================================================
--- net/if_ethersubr.c	(revision 223932)
+++ net/if_ethersubr.c	(working copy)
@@ -598,16 +598,16 @@
 	}
 	eh = mtod(m, struct ether_header *);
 	etype = ntohs(eh->ether_type);
-	if (m->m_pkthdr.rcvif == NULL) {
-		if_printf(ifp, "discard frame w/o interface pointer\n");
+	if (m->m_pkthdr.rcvif_idx == 0) {
+		if_printf(ifp, "discard frame w/o interface index\n");
 		ifp->if_ierrors++;
 		m_freem(m);
 		return;
 	}
 #ifdef DIAGNOSTIC
-	if (m->m_pkthdr.rcvif != ifp) {
-		if_printf(ifp, "Warning, frame marked as received on %s\n",
-			m->m_pkthdr.rcvif->if_xname);
+	if (mbuf_rcvif(m) != ifp) {
+		if_printf(ifp, "Warning, frame marked as received on %u\n",
+			m->m_pkthdr.rcvif_idx);
 	}
 #endif
 
@@ -659,7 +659,7 @@
 		    ("%s: if_lagg not loaded!", __func__));
 		m = (*lagg_input_p)(ifp, m);
 		if (m != NULL)
-			ifp = m->m_pkthdr.rcvif;
+			ifp = mbuf_rcvif(m);
 		else 
 			return;
 	}
@@ -764,7 +764,7 @@
 ether_nh_input(struct mbuf *m)
 {
 
-	ether_input_internal(m->m_pkthdr.rcvif, m);
+	ether_input_internal(mbuf_rcvif(m), m);
 }
 
 static struct netisr_handler	ether_nh = {
@@ -791,7 +791,7 @@
 	 * We will rely on rcvif being set properly in the deferred context,
 	 * so assert it is correct here.
 	 */
-	KASSERT(m->m_pkthdr.rcvif == ifp, ("%s: ifnet mismatch", __func__));
+	KASSERT(mbuf_rcvif(m) == ifp, ("%s: ifnet mismatch", __func__));
 
 	netisr_dispatch(NETISR_ETHER, m);
 }
Index: net/if_gif.c
===================================================================
--- net/if_gif.c	(revision 223932)
+++ net/if_gif.c	(working copy)
@@ -499,7 +499,7 @@
 		return;
 	}
 	sc = ifp->if_softc;
-	m->m_pkthdr.rcvif = ifp;
+	m_set_rcvif(m, ifp);
 
 #ifdef MAC
 	mac_ifnet_create_mbuf(ifp, m);
@@ -572,7 +572,7 @@
 		m_adj(m, sizeof(struct etherip_header));
 
 		m->m_flags &= ~(M_BCAST|M_MCAST);
-		m->m_pkthdr.rcvif = ifp;
+		m_set_rcvif(m, ifp);
 
 		if (ifp->if_bridge) {
 			oldifp = ifp;
Index: net/if_loop.c
===================================================================
--- net/if_loop.c	(revision 223932)
+++ net/if_loop.c	(working copy)
@@ -282,7 +282,7 @@
 
 	M_ASSERTPKTHDR(m);
 	m_tag_delete_nonpersistent(m);
-	m->m_pkthdr.rcvif = ifp;
+	m_set_rcvif(m, ifp);
 
 #ifdef MAC
 	mac_ifnet_create_mbuf(ifp, m);
Index: net/if_tap.c
===================================================================
--- net/if_tap.c	(revision 223932)
+++ net/if_tap.c	(working copy)
@@ -924,7 +924,7 @@
 		return (ENOBUFS);
 	}
 
-	m->m_pkthdr.rcvif = ifp;
+	m_set_rcvif(m, ifp);
 
 	/*
 	 * Only pass a unicast frame to ether_input(), if it would actually
Index: net/rtsock.c
===================================================================
--- net/rtsock.c	(revision 223932)
+++ net/rtsock.c	(working copy)
@@ -1020,7 +1020,7 @@
 	if (m == NULL)
 		return (m);
 	m->m_pkthdr.len = m->m_len = len;
-	m->m_pkthdr.rcvif = NULL;
+	m->m_pkthdr.rcvif_idx = 0;
 	rtm = mtod(m, struct rt_msghdr *);
 	bzero((caddr_t)rtm, len);
 	for (i = 0; i < RTAX_MAX; i++) {
@@ -1374,7 +1374,7 @@
 	}
 #ifdef VIMAGE
 	if (V_loif)
-		m->m_pkthdr.rcvif = V_loif;
+		m_set_rcvif(m, V_loif);
 	else {
 		m_freem(m);
 		return;
Index: net/if_faith.c
===================================================================
--- net/if_faith.c	(revision 223932)
+++ net/if_faith.c	(working copy)
@@ -237,7 +237,7 @@
 
 	/* XXX do we need more sanity checks? */
 
-	m->m_pkthdr.rcvif = ifp;
+	m_set_rcvif(m, ifp);
 	ifp->if_ipackets++;
 	ifp->if_ibytes += m->m_pkthdr.len;
 	netisr_dispatch(isr, m);
Index: net/if_iso88025subr.c
===================================================================
--- net/if_iso88025subr.c	(revision 223932)
+++ net/if_iso88025subr.c	(working copy)
@@ -467,7 +467,7 @@
 		m_freem(m);
 		return;
 	}
-	if (m->m_pkthdr.rcvif == NULL) {
+	if (mbuf_rcvif(m) == NULL) {
 		if_printf(ifp, "discard frame w/o interface pointer\n");
 		ifp->if_ierrors++;
  		m_freem(m);
Index: net/if_var.h
===================================================================
--- net/if_var.h	(revision 223932)
+++ net/if_var.h	(working copy)
@@ -142,6 +142,7 @@
 	struct	bpf_if *if_bpf;		/* packet filter structure */
 	u_short	if_index;		/* numeric abbreviation for this if  */
 	short	if_index_reserved;	/* spare space to grow if_index */
+	u_int	if_unique;		/* unique id */
 	struct  ifvlantrunk *if_vlantrunk; /* pointer to 802.1q data */
 	int	if_flags;		/* up/down, broadcast, etc. */
 	int	if_capabilities;	/* interface features & capabilities */
@@ -206,7 +207,7 @@
 	char	if_cspare[3];
 	char	*if_description;	/* interface description */
 	void	*if_pspare[7];
-	int	if_ispare[4];
+	int	if_ispare[3];
 };
 
 typedef void if_init_f_t(void *);
Index: net/if_epair.c
===================================================================
--- net/if_epair.c	(revision 223932)
+++ net/if_epair.c	(working copy)
@@ -250,7 +250,7 @@
 	struct ifnet *ifp;
 	struct epair_softc *sc;
 
-	ifp = m->m_pkthdr.rcvif;
+	ifp = mbuf_rcvif(m);
 	(*ifp->if_input)(ifp, m);
 	sc = ifp->if_softc;
 	EPAIR_REFCOUNT_RELEASE(&sc->refcount);
@@ -264,7 +264,7 @@
 epair_nh_m2cpuid(struct mbuf *m, uintptr_t source, u_int *cpuid)
 {
 
-	*cpuid = cpuid_from_ifp(m->m_pkthdr.rcvif);
+	*cpuid = cpuid_from_ifp(mbuf_rcvif(m));
 
 	return (m);
 }
@@ -430,7 +430,7 @@
 		 * packet is in transit as we rely on rcvif to stay valid.
 		 */
 		EPAIR_REFCOUNT_AQUIRE(&sc->refcount);
-		m->m_pkthdr.rcvif = oifp;
+		m_set_rcvif(m, oifp);
 		CURVNET_SET_QUIET(oifp->if_vnet);
 		error = netisr_queue(NETISR_EPAIR, m);
 		CURVNET_RESTORE();
@@ -552,7 +552,7 @@
 	 * packet is in transit as we rely on rcvif to stay valid.
 	 */
 	EPAIR_REFCOUNT_AQUIRE(&sc->refcount);
-	m->m_pkthdr.rcvif = oifp;
+	m_set_rcvif(m, oifp);
 	CURVNET_SET_QUIET(oifp->if_vnet);
 	error = netisr_queue(NETISR_EPAIR, m);
 	CURVNET_RESTORE();
Index: net/if_fddisubr.c
===================================================================
--- net/if_fddisubr.c	(revision 223932)
+++ net/if_fddisubr.c	(working copy)
@@ -378,7 +378,7 @@
 		m_freem(m);
 		return;
 	}
-	if (m->m_pkthdr.rcvif == NULL) {
+	if (mbuf_rcvif(m) == NULL) {
 		if_printf(ifp, "discard frame w/o interface pointer\n");
 		ifp->if_ierrors++;
 		m_freem(m);
Index: net/if_tun.c
===================================================================
--- net/if_tun.c	(revision 223932)
+++ net/if_tun.c	(working copy)
@@ -877,7 +877,7 @@
 		return (ENOBUFS);
 	}
 
-	m->m_pkthdr.rcvif = ifp;
+	m_set_rcvif(m, ifp);
 #ifdef MAC
 	mac_ifnet_create_mbuf(ifp, m);
 #endif
Index: net/if_spppfr.c
===================================================================
--- net/if_spppfr.c	(revision 223932)
+++ net/if_spppfr.c	(working copy)
@@ -384,7 +384,7 @@
 	MGETHDR (m, M_DONTWAIT, MT_DATA);
 	if (! m)
 		return;
-	m->m_pkthdr.rcvif = 0;
+	m->m_pkthdr.rcvif_idx = 0;
 
 	h = mtod (m, u_char*);
 	p = h;
@@ -505,7 +505,7 @@
 	if (! m)
 		return;
 	m->m_pkthdr.len = m->m_len = 10 + sizeof (*reply);
-	m->m_pkthdr.rcvif = 0;
+	m->m_pkthdr.rcvif_idx = 0;
 
 	h = mtod (m, u_char*);
 	reply = (struct arp_req*) (h + 10);
Index: net/if_lagg.c
===================================================================
--- net/if_lagg.c	(revision 223932)
+++ net/if_lagg.c	(working copy)
@@ -1524,7 +1524,7 @@
 	struct ifnet *ifp = sc->sc_ifp;
 
 	/* Just pass in the packet to our lagg device */
-	m->m_pkthdr.rcvif = ifp;
+	m_set_rcvif(m, ifp);
 
 	return (m);
 }
@@ -1573,7 +1573,7 @@
 	struct lagg_port *tmp_tp;
 
 	if (lp == sc->sc_primary || lagg_failover_rx_all) {
-		m->m_pkthdr.rcvif = ifp;
+		m_set_rcvif(m, ifp);
 		return (m);
 	}
 
@@ -1584,7 +1584,7 @@
 		 * our links are down. Weird, but process it anyways.
 		 */
 		if ((tmp_tp == NULL || tmp_tp == lp)) {
-			m->m_pkthdr.rcvif = ifp;
+			m_set_rcvif(m, ifp);
 			return (m);
 		}
 	}
@@ -1701,7 +1701,7 @@
 	struct ifnet *ifp = sc->sc_ifp;
 
 	/* Just pass in the packet to our lagg device */
-	m->m_pkthdr.rcvif = ifp;
+	m_set_rcvif(m, ifp);
 
 	return (m);
 }
@@ -1810,6 +1810,6 @@
 		return (NULL);
 	}
 
-	m->m_pkthdr.rcvif = ifp;
+	m_set_rcvif(m, ifp);
 	return (m);
 }
Index: net/if_bridgevar.h
===================================================================
--- net/if_bridgevar.h	(revision 223932)
+++ net/if_bridgevar.h	(working copy)
@@ -311,7 +311,7 @@
 	    ("%s: if_bridge not loaded!", __func__));	\
 	_m = (*bridge_input_p)(_ifp, _m);		\
 	if (_m != NULL)					\
-		_ifp = _m->m_pkthdr.rcvif;		\
+		_ifp = mbuf_rcvif(_m);			\
 } while (0)
 
 #define BRIDGE_OUTPUT(_ifp, _m, _err)	do {    		\
Index: net/if_spppsubr.c
===================================================================
--- net/if_spppsubr.c	(revision 223932)
+++ net/if_spppsubr.c	(working copy)
@@ -1416,7 +1416,7 @@
 	if (! m)
 		return;
 	m->m_pkthdr.len = m->m_len = PPP_HEADER_LEN + CISCO_PACKET_LEN;
-	m->m_pkthdr.rcvif = 0;
+	m->m_pkthdr.rcvif_idx = 0;
 
 	h = mtod (m, struct ppp_header*);
 	h->address = CISCO_MULTICAST;
@@ -1464,7 +1464,7 @@
 	if (! m)
 		return;
 	m->m_pkthdr.len = m->m_len = PPP_HEADER_LEN + LCP_HEADER_LEN + len;
-	m->m_pkthdr.rcvif = 0;
+	m->m_pkthdr.rcvif_idx = 0;
 
 	h = mtod (m, struct ppp_header*);
 	h->address = PPP_ALLSTATIONS;        /* broadcast address */
@@ -4767,7 +4767,7 @@
 	MGETHDR (m, M_DONTWAIT, MT_DATA);
 	if (! m)
 		return;
-	m->m_pkthdr.rcvif = 0;
+	m->m_pkthdr.rcvif_idx = 0;
 
 	h = mtod (m, struct ppp_header*);
 	h->address = PPP_ALLSTATIONS;		/* broadcast address */
Index: netinet6/raw_ip6.c
===================================================================
--- netinet6/raw_ip6.c	(revision 223932)
+++ netinet6/raw_ip6.c	(working copy)
@@ -170,7 +170,7 @@
 
 	init_sin6(&fromsa, m); /* general init */
 
-	ifp = m->m_pkthdr.rcvif;
+	ifp = mbuf_rcvif(m);
 
 	INP_INFO_RLOCK(&V_ripcbinfo);
 	LIST_FOREACH(in6p, &V_ripcb, inp_list) {
Index: netinet6/ip6_output.c
===================================================================
--- netinet6/ip6_output.c	(revision 223932)
+++ netinet6/ip6_output.c	(working copy)
@@ -737,7 +737,7 @@
 				 * some versions of MGETHDR() does not
 				 * initialize the field.
 				 */
-				m->m_pkthdr.rcvif = NULL;
+				m->m_pkthdr.rcvif_idx = 0;
 				if (ip6_mforward(ip6, ifp, m) != 0) {
 					m_freem(m);
 					goto done;
@@ -823,7 +823,7 @@
 		 *       contiguous unless the flag is set.
 		 */
 		m->m_flags |= M_LOOP;
-		m->m_pkthdr.rcvif = ifp;
+		m_set_rcvif(m, ifp);
 		if (ip6_process_hopopts(m, (u_int8_t *)(hbh + 1),
 		    ((hbh->ip6h_len + 1) << 3) - sizeof(struct ip6_hbh),
 		    &dummy, &plen) < 0) {
@@ -832,7 +832,7 @@
 			goto done;
 		}
 		m->m_flags &= ~M_LOOP; /* XXX */
-		m->m_pkthdr.rcvif = NULL;
+		m->m_pkthdr.rcvif_idx = 0;
 	}
 
 	/* Jump over all PFIL processing if hooks are not active. */
@@ -851,8 +851,8 @@
 		m->m_flags |= M_SKIP_FIREWALL;
 		/* If destination is now ourself drop to ip6_input(). */
 		if (in6_localaddr(&ip6->ip6_dst)) {
-			if (m->m_pkthdr.rcvif == NULL)
-				m->m_pkthdr.rcvif = V_loif;
+			if (mbuf_rcvif(m) == NULL)
+				m_set_rcvif(m, V_loif);
 			if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
 				m->m_pkthdr.csum_flags |=
 				    CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
@@ -1031,7 +1031,7 @@
 				V_ip6stat.ip6s_odropped++;
 				goto sendorfree;
 			}
-			m->m_pkthdr.rcvif = NULL;
+			m->m_pkthdr.rcvif_idx = 0;
 			m->m_flags = m0->m_flags & M_COPYFLAGS;
 			*mnext = m;
 			mnext = &m->m_nextpkt;
@@ -1058,7 +1058,7 @@
 			}
 			m_cat(m, m_frgpart);
 			m->m_pkthdr.len = len + hlen + sizeof(*ip6f);
-			m->m_pkthdr.rcvif = NULL;
+			m->m_pkthdr.rcvif_idx = 0;
 			ip6f->ip6f_reserved = 0;
 			ip6f->ip6f_ident = id;
 			ip6f->ip6f_nxt = nextproto;
Index: netinet6/icmp6.c
===================================================================
--- netinet6/icmp6.c	(revision 223932)
+++ netinet6/icmp6.c	(working copy)
@@ -384,10 +384,10 @@
 	 * icmp6_reflect() is designed to be in the input path.
 	 * icmp6_error() can be called from both input and output path,
 	 * and if we are in output path rcvif could contain bogus value.
-	 * clear m->m_pkthdr.rcvif for safety, we should have enough scope
+	 * clear m->m_pkthdr.rcvif_idx for safety, we should have enough scope
 	 * information in ip header (nip6).
 	 */
-	m->m_pkthdr.rcvif = NULL;
+	m->m_pkthdr.rcvif_idx = 0;
 
 	ICMP6STAT_INC(icp6s_outhist[type]);
 	icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */
@@ -417,7 +417,7 @@
 	char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
 	int ip6len, error;
 
-	ifp = m->m_pkthdr.rcvif;
+	ifp = mbuf_rcvif(m);
 
 #ifndef PULLDOWN_TEST
 	IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_hdr), IPPROTO_DONE);
@@ -446,7 +446,7 @@
 		inm = in6m_lookup(ifp, &ip6->ip6_dst);
 		if (inm == NULL) {
 			IP6STAT_INC(ip6s_notmember);
-			in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
+			in6_ifstat_inc(mbuf_rcvif(m), ifs6_in_discard);
 			goto freeit;
 		}
 	}
@@ -722,7 +722,7 @@
 				/* Give up remote */
 				break;
 			}
-			n->m_pkthdr.rcvif = NULL;
+			n->m_pkthdr.rcvif_idx = 0;
 			n->m_len = 0;
 			maxhlen = M_TRAILINGSPACE(n) - maxlen;
 			pr = curthread->td_ucred->cr_prison;
@@ -1006,6 +1006,7 @@
 		struct ip6_frag *fh;
 		struct ip6_rthdr *rth;
 		struct ip6_rthdr0 *rth0;
+		struct ifnet *ifp;
 		int rthlen;
 
 		while (1) { /* XXX: should avoid infinite loop explicitly? */
@@ -1156,13 +1157,14 @@
 			icmp6dst.sin6_addr = eip6->ip6_dst;
 		else
 			icmp6dst.sin6_addr = *finaldst;
-		if (in6_setscope(&icmp6dst.sin6_addr, m->m_pkthdr.rcvif, NULL))
+		ifp = mbuf_rcvif(m);
+		if (in6_setscope(&icmp6dst.sin6_addr, ifp, NULL))
 			goto freeit;
 		bzero(&icmp6src, sizeof(icmp6src));
 		icmp6src.sin6_len = sizeof(struct sockaddr_in6);
 		icmp6src.sin6_family = AF_INET6;
 		icmp6src.sin6_addr = eip6->ip6_src;
-		if (in6_setscope(&icmp6src.sin6_addr, m->m_pkthdr.rcvif, NULL))
+		if (in6_setscope(&icmp6src.sin6_addr, ifp, NULL))
 			goto freeit;
 		icmp6src.sin6_flowinfo =
 		    (eip6->ip6_flow & IPV6_FLOWLABEL_MASK);
@@ -1244,7 +1246,7 @@
 	bzero(&inc, sizeof(inc));
 	inc.inc_flags |= INC_ISIPV6;
 	inc.inc6_faddr = *dst;
-	if (in6_setscope(&inc.inc6_faddr, m->m_pkthdr.rcvif, NULL))
+	if (in6_setscope(&inc.inc6_faddr, mbuf_rcvif(m), NULL))
 		return;
 
 	if (mtu < tcp_maxmtu6(&inc, NULL)) {
@@ -1390,7 +1392,7 @@
 			/* m_pulldown instead of copy? */
 			m_copydata(m, off + sizeof(struct icmp6_nodeinfo),
 			    subjlen, (caddr_t)&in6_subj);
-			if (in6_setscope(&in6_subj, m->m_pkthdr.rcvif, NULL))
+			if (in6_setscope(&in6_subj, mbuf_rcvif(m), NULL))
 				goto bad;
 
 			subj = (char *)&in6_subj;
@@ -2157,7 +2159,7 @@
 	struct in6_ifaddr *ia = NULL;
 	int plen;
 	int type, code;
-	struct ifnet *outif = NULL;
+	struct ifnet *ifp, *outif = NULL;
 	struct in6_addr origdst, src, *srcp = NULL;
 
 	/* too short to reflect */
@@ -2285,9 +2287,9 @@
 	ip6->ip6_nxt = IPPROTO_ICMPV6;
 	if (outif)
 		ip6->ip6_hlim = ND_IFINFO(outif)->chlim;
-	else if (m->m_pkthdr.rcvif) {
+	else if ((ifp = mbuf_rcvif(m)) != NULL) {
 		/* XXX: This may not be the outgoing interface */
-		ip6->ip6_hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim;
+		ip6->ip6_hlim = ND_IFINFO(ifp)->chlim;
 	} else
 		ip6->ip6_hlim = V_ip6_defhlim;
 
@@ -2369,7 +2371,7 @@
 	if (!m)
 		return;
 
-	ifp = m->m_pkthdr.rcvif;
+	ifp = mbuf_rcvif(m);
 
 	if (!ifp)
 		return;
@@ -2393,8 +2395,8 @@
 	redtgt6 = nd_rd->nd_rd_target;
 	reddst6 = nd_rd->nd_rd_dst;
 
-	if (in6_setscope(&redtgt6, m->m_pkthdr.rcvif, NULL) ||
-	    in6_setscope(&reddst6, m->m_pkthdr.rcvif, NULL)) {
+	if (in6_setscope(&redtgt6, ifp, NULL) ||
+	    in6_setscope(&reddst6, ifp, NULL)) {
 		goto freeit;
 	}
 
@@ -2613,7 +2615,6 @@
 		MCLGET(m, M_DONTWAIT);
 	if (!m)
 		goto fail;
-	m->m_pkthdr.rcvif = NULL;
 	m->m_len = 0;
 	maxlen = M_TRAILINGSPACE(m);
 	maxlen = min(IPV6_MMTU, maxlen);
Index: netinet6/udp6_usrreq.c
===================================================================
--- netinet6/udp6_usrreq.c	(revision 223932)
+++ netinet6/udp6_usrreq.c	(working copy)
@@ -182,7 +182,7 @@
 	int plen, ulen;
 	struct sockaddr_in6 fromsa;
 
-	ifp = m->m_pkthdr.rcvif;
+	ifp = mbuf_rcvif(m);
 	ip6 = mtod(m, struct ip6_hdr *);
 
 	if (faithprefix_p != NULL && (*faithprefix_p)(&ip6->ip6_dst)) {
@@ -379,7 +379,7 @@
 	 */
 	inp = in6_pcblookup_mbuf(&V_udbinfo, &ip6->ip6_src, uh->uh_sport,
 	    &ip6->ip6_dst, uh->uh_dport, INPLOOKUP_WILDCARD |
-	    INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif, m);
+	    INPLOOKUP_RLOCKPCB, mbuf_rcvif(m), m);
 	if (inp == NULL) {
 		if (udp_log_in_vain) {
 			char ip6bufs[INET6_ADDRSTRLEN];
Index: netinet6/ip6_forward.c
===================================================================
--- netinet6/ip6_forward.c	(revision 223932)
+++ netinet6/ip6_forward.c	(working copy)
@@ -139,7 +139,7 @@
 			    ip6_sprintf(ip6bufs, &ip6->ip6_src),
 			    ip6_sprintf(ip6bufd, &ip6->ip6_dst),
 			    ip6->ip6_nxt,
-			    if_name(m->m_pkthdr.rcvif));
+			    if_name(mbuf_rcvif(m)));
 		}
 		m_freem(m);
 		return;
@@ -357,7 +357,7 @@
 		RT_UNLOCK(rin6.ro_rt);
 	else {
 		V_ip6stat.ip6s_noroute++;
-		in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_noroute);
+		in6_ifstat_inc(mbuf_rcvif(m), ifs6_in_noroute);
 		if (mcopy) {
 			icmp6_error(mcopy, ICMP6_DST_UNREACH,
 			ICMP6_DST_UNREACH_NOROUTE, 0);
@@ -385,7 +385,7 @@
 		V_ip6stat.ip6s_badscope++;
 		goto bad;
 	}
-	if (in6_setscope(&src_in6, m->m_pkthdr.rcvif, &inzone)) {
+	if (in6_setscope(&src_in6, mbuf_rcvif(m), &inzone)) {
 		V_ip6stat.ip6s_cantforward++;
 		V_ip6stat.ip6s_badscope++;
 		goto bad;
@@ -407,7 +407,7 @@
 			    ip6_sprintf(ip6bufs, &ip6->ip6_src),
 			    ip6_sprintf(ip6bufd, &ip6->ip6_dst),
 			    ip6->ip6_nxt,
-			    if_name(m->m_pkthdr.rcvif), if_name(rt->rt_ifp));
+			    if_name(mbuf_rcvif(m)), if_name(rt->rt_ifp));
 		}
 		if (mcopy)
 			icmp6_error(mcopy, ICMP6_DST_UNREACH,
@@ -423,7 +423,7 @@
 	 * packet to a different zone by (e.g.) a default route.
 	 */
 	dst_in6 = ip6->ip6_dst;
-	if (in6_setscope(&dst_in6, m->m_pkthdr.rcvif, &inzone) != 0 ||
+	if (in6_setscope(&dst_in6, mbuf_rcvif(m), &inzone) != 0 ||
 	    in6_setscope(&dst_in6, rt->rt_ifp, &outzone) != 0 ||
 	    inzone != outzone) {
 		V_ip6stat.ip6s_cantforward++;
@@ -483,7 +483,7 @@
 	 * Also, don't send redirect if forwarding using a route
 	 * modified by a redirect.
 	 */
-	if (V_ip6_sendredirects && rt->rt_ifp == m->m_pkthdr.rcvif && !srcrt &&
+	if (V_ip6_sendredirects && rt->rt_ifp == mbuf_rcvif(m) && !srcrt &&
 #ifdef IPSEC
 	    !ipsecrt &&
 #endif /* IPSEC */
@@ -530,16 +530,16 @@
 		if ((rt->rt_flags & (RTF_BLACKHOLE|RTF_REJECT)) == 0)
 #endif
 		{
-			printf("ip6_forward: outgoing interface is loopback. "
+			log(LOG_DEBUG, "ip6_forward: outgoing interface is loopback. "
 			       "src %s, dst %s, nxt %d, rcvif %s, outif %s\n",
 			       ip6_sprintf(ip6bufs, &ip6->ip6_src),
 			       ip6_sprintf(ip6bufd, &ip6->ip6_dst),
-			       ip6->ip6_nxt, if_name(m->m_pkthdr.rcvif),
+			       ip6->ip6_nxt, if_name(mbuf_rcvif(m)),
 			       if_name(rt->rt_ifp));
 		}
 
 		/* we can just use rcvif in forwarding. */
-		origifp = m->m_pkthdr.rcvif;
+		origifp = mbuf_rcvif(m);
 	}
 	else
 		origifp = rt->rt_ifp;
Index: netinet6/nd6_nbr.c
===================================================================
--- netinet6/nd6_nbr.c	(revision 223932)
+++ netinet6/nd6_nbr.c	(working copy)
@@ -100,7 +100,7 @@
 void
 nd6_ns_input(struct mbuf *m, int off, int icmp6len)
 {
-	struct ifnet *ifp = m->m_pkthdr.rcvif;
+	struct ifnet *ifp = mbuf_rcvif(m);
 	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
 	struct nd_neighbor_solicit *nd_ns;
 	struct in6_addr saddr6 = ip6->ip6_src;
@@ -423,7 +423,7 @@
 	}
 	if (m == NULL)
 		return;
-	m->m_pkthdr.rcvif = NULL;
+	m->m_pkthdr.rcvif_idx = 0;
 
 	bzero(&ro, sizeof(ro));
 
@@ -613,7 +613,7 @@
 void
 nd6_na_input(struct mbuf *m, int off, int icmp6len)
 {
-	struct ifnet *ifp = m->m_pkthdr.rcvif;
+	struct ifnet *ifp = mbuf_rcvif(m);
 	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
 	struct nd_neighbor_advert *nd_na;
 	struct in6_addr daddr6 = ip6->ip6_dst;
@@ -988,7 +988,7 @@
 	}
 	if (m == NULL)
 		return;
-	m->m_pkthdr.rcvif = NULL;
+	m->m_pkthdr.rcvif_idx = 0;
 
 	if (IN6_IS_ADDR_MULTICAST(&daddr6)) {
 		m->m_flags |= M_MCAST;
Index: netinet6/mld6.c
===================================================================
--- netinet6/mld6.c	(revision 223932)
+++ netinet6/mld6.c	(working copy)
@@ -1250,7 +1250,7 @@
 
 	CTR3(KTR_MLD, "%s: called w/mbuf (%p,%d)", __func__, m, off);
 
-	ifp = m->m_pkthdr.rcvif;
+	ifp = mbuf_rcvif(m);
 
 	ip6 = mtod(m, struct ip6_hdr *);
 
@@ -3094,7 +3094,7 @@
 
 	mld_scrub_context(m0);
 	m->m_flags &= ~(M_PROTOFLAGS);
-	m0->m_pkthdr.rcvif = V_loif;
+	m_set_rcvif(m0, V_loif);
 
 	ip6 = mtod(m0, struct ip6_hdr *);
 #if 0
Index: netinet6/ip6_input.c
===================================================================
--- netinet6/ip6_input.c	(revision 223932)
+++ netinet6/ip6_input.c	(working copy)
@@ -332,7 +332,7 @@
 	u_int32_t plen;
 	u_int32_t rtalert = ~0;
 	int nxt, ours = 0;
-	struct ifnet *deliverifp = NULL, *ifp = NULL;
+	struct ifnet *deliverifp = NULL, *ifp;
 	struct in6_addr odst;
 	struct route_in6 rin6;
 	int srcrt = 0;
@@ -357,6 +357,8 @@
 	 */
 	ip6_delaux(m);
 
+	ifp = mbuf_rcvif(m);
+
 	/*
 	 * mbuf statistics
 	 */
@@ -370,8 +372,8 @@
 		if (m->m_next) {
 			if (m->m_flags & M_LOOP) {
 				V_ip6stat.ip6s_m2m[V_loif->if_index]++;
-			} else if (m->m_pkthdr.rcvif->if_index < M2MMAX)
-				V_ip6stat.ip6s_m2m[m->m_pkthdr.rcvif->if_index]++;
+			} else if (ifp->if_index < M2MMAX)
+				V_ip6stat.ip6s_m2m[ifp->if_index]++;
 			else
 				V_ip6stat.ip6s_m2m[0]++;
 		} else
@@ -380,12 +382,12 @@
 	}
 
 	/* drop the packet if IPv6 operation is disabled on the IF */
-	if ((ND_IFINFO(m->m_pkthdr.rcvif)->flags & ND6_IFF_IFDISABLED)) {
+	if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED)) {
 		m_freem(m);
 		return;
 	}
 
-	in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_receive);
+	in6_ifstat_inc(ifp, ifs6_in_receive);
 	V_ip6stat.ip6s_total++;
 
 #ifndef PULLDOWN_TEST
@@ -421,11 +423,9 @@
 #endif
 
 	if (m->m_len < sizeof(struct ip6_hdr)) {
-		struct ifnet *inifp;
-		inifp = m->m_pkthdr.rcvif;
 		if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) {
 			V_ip6stat.ip6s_toosmall++;
-			in6_ifstat_inc(inifp, ifs6_in_hdrerr);
+			in6_ifstat_inc(ifp, ifs6_in_hdrerr);
 			return;
 		}
 	}
@@ -434,7 +434,7 @@
 
 	if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) {
 		V_ip6stat.ip6s_badvers++;
-		in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr);
+		in6_ifstat_inc(ifp, ifs6_in_hdrerr);
 		goto bad;
 	}
 
@@ -449,7 +449,7 @@
 		 * XXX: "badscope" is not very suitable for a multicast source.
 		 */
 		V_ip6stat.ip6s_badscope++;
-		in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
+		in6_ifstat_inc(ifp, ifs6_in_addrerr);
 		goto bad;
 	}
 	if (IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst) &&
@@ -461,7 +461,7 @@
 		 * as the outgoing/incoming interface.
 		 */
 		V_ip6stat.ip6s_badscope++;
-		in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
+		in6_ifstat_inc(ifp, ifs6_in_addrerr);
 		goto bad;
 	}
 
@@ -486,7 +486,7 @@
 	if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) ||
 	    IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) {
 		V_ip6stat.ip6s_badscope++;
-		in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
+		in6_ifstat_inc(ifp, ifs6_in_addrerr);
 		goto bad;
 	}
 #if 0
@@ -500,7 +500,7 @@
 	if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) ||
 	    IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) {
 		V_ip6stat.ip6s_badscope++;
-		in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
+		in6_ifstat_inc(ifp, ifs6_in_addrerr);
 		goto bad;
 	}
 #endif
@@ -525,12 +525,13 @@
 	if (!PFIL_HOOKED(&V_inet6_pfil_hook))
 		goto passin;
 
-	if (pfil_run_hooks(&V_inet6_pfil_hook, &m,
-	    m->m_pkthdr.rcvif, PFIL_IN, NULL))
+	if (pfil_run_hooks(&V_inet6_pfil_hook, &m, ifp, PFIL_IN, NULL))
 		return;
 	if (m == NULL)			/* consumed by filter */
 		return;
+
 	ip6 = mtod(m, struct ip6_hdr *);
+	ifp = mbuf_rcvif(m);	/* could pfilters change it? */
 	srcrt = !IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst);
 
 passin:
@@ -548,8 +549,8 @@
 		V_ip6stat.ip6s_badscope++; /* XXX */
 		goto bad;
 	}
-	if (in6_setscope(&ip6->ip6_src, m->m_pkthdr.rcvif, NULL) ||
-	    in6_setscope(&ip6->ip6_dst, m->m_pkthdr.rcvif, NULL)) {
+	if (in6_setscope(&ip6->ip6_src, ifp, NULL) ||
+	    in6_setscope(&ip6->ip6_dst, ifp, NULL)) {
 		V_ip6stat.ip6s_badscope++;
 		goto bad;
 	}
@@ -560,8 +561,8 @@
 	 */
 	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 		ours = 1;
-		in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast);
-		deliverifp = m->m_pkthdr.rcvif;
+		in6_ifstat_inc(ifp, ifs6_in_mcast);
+		deliverifp = ifp;
 		goto hbhcheck;
 	}
 
@@ -573,7 +574,6 @@
 	dst6.sin6_family = AF_INET6;
 	dst6.sin6_len = sizeof(struct sockaddr_in6);
 	dst6.sin6_addr = ip6->ip6_dst;
-	ifp = m->m_pkthdr.rcvif;
 	IF_AFDATA_LOCK(ifp);
 	lle = lla_lookup(LLTABLE6(ifp), 0,
 	     (struct sockaddr *)&dst6);
@@ -755,7 +755,7 @@
 	 */
 	if (!V_ip6_forwarding) {
 		V_ip6stat.ip6s_cantforward++;
-		in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
+		in6_ifstat_inc(ifp, ifs6_in_discard);
 		goto bad;
 	}
 
@@ -793,7 +793,7 @@
 
 		if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) {
 #if 0	/*touches NULL pointer*/
-			in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
+			in6_ifstat_inc(ifp, ifs6_in_discard);
 #endif
 			goto out;	/* m have already been freed */
 		}
@@ -813,8 +813,8 @@
 			 * (non-zero) payload length to the variable plen.
 			 */
 			V_ip6stat.ip6s_badoptions++;
-			in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
-			in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr);
+			in6_ifstat_inc(ifp, ifs6_in_discard);
+			in6_ifstat_inc(ifp, ifs6_in_hdrerr);
 			icmp6_error(m, ICMP6_PARAM_PROB,
 				    ICMP6_PARAMPROB_HEADER,
 				    (caddr_t)&ip6->ip6_plen - (caddr_t)ip6);
@@ -865,7 +865,7 @@
 	 */
 	if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) {
 		V_ip6stat.ip6s_tooshort++;
-		in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated);
+		in6_ifstat_inc(ifp, ifs6_in_truncated);
 		goto bad;
 	}
 	if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) {
@@ -893,9 +893,9 @@
 		 * unnecessarily calling into ip6_mforward().
 		 */
 		if (ip6_mforward &&
-		    ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) {
+		    ip6_mforward(ip6, ifp, m)) {
 			IP6STAT_INC(ip6s_cantforward);
-			in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
+			in6_ifstat_inc(ifp, ifs6_in_discard);
 			goto bad;
 		}
 	} else if (!ours) {
@@ -917,7 +917,7 @@
 	if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) ||
 	    IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) {
 		V_ip6stat.ip6s_badscope++;
-		in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
+		in6_ifstat_inc(ifp, ifs6_in_addrerr);
 		goto bad;
 	}
 
@@ -940,7 +940,7 @@
 		 */
 		if (m->m_pkthdr.len < off) {
 			V_ip6stat.ip6s_tooshort++;
-			in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated);
+			in6_ifstat_inc(ifp, ifs6_in_truncated);
 			goto bad;
 		}
 
@@ -1277,8 +1277,7 @@
 
 		bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr));
 		in6_clearscope(&pi6.ipi6_addr);	/* XXX */
-		pi6.ipi6_ifindex =
-		    (m && m->m_pkthdr.rcvif) ? m->m_pkthdr.rcvif->if_index : 0;
+		pi6.ipi6_ifindex = (m) ? m->m_pkthdr.rcvif_idx : 0;
 
 		*mp = sbcreatecontrol((caddr_t) &pi6,
 		    sizeof(struct in6_pktinfo),
Index: netinet6/nd6_rtr.c
===================================================================
--- netinet6/nd6_rtr.c	(revision 223932)
+++ netinet6/nd6_rtr.c	(working copy)
@@ -118,7 +118,7 @@
 void
 nd6_rs_input(struct mbuf *m, int off, int icmp6len)
 {
-	struct ifnet *ifp = m->m_pkthdr.rcvif;
+	struct ifnet *ifp = mbuf_rcvif(m);
 	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
 	struct nd_router_solicit *nd_rs;
 	struct in6_addr saddr6 = ip6->ip6_src;
@@ -205,7 +205,7 @@
 void
 nd6_ra_input(struct mbuf *m, int off, int icmp6len)
 {
-	struct ifnet *ifp = m->m_pkthdr.rcvif;
+	struct ifnet *ifp = mbuf_rcvif(m);
 	struct nd_ifinfo *ndi = ND_IFINFO(ifp);
 	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
 	struct nd_router_advert *nd_ra;
@@ -342,7 +342,7 @@
 			pr.ndpr_prefix.sin6_family = AF_INET6;
 			pr.ndpr_prefix.sin6_len = sizeof(pr.ndpr_prefix);
 			pr.ndpr_prefix.sin6_addr = pi->nd_opt_pi_prefix;
-			pr.ndpr_ifp = (struct ifnet *)m->m_pkthdr.rcvif;
+			pr.ndpr_ifp = mbuf_rcvif(m);
 
 			pr.ndpr_raf_onlink = (pi->nd_opt_pi_flags_reserved &
 			    ND_OPT_PI_FLAG_ONLINK) ? 1 : 0;
Index: sys/mbuf.h
===================================================================
--- sys/mbuf.h	(revision 223932)
+++ sys/mbuf.h	(working copy)
@@ -111,7 +111,8 @@
  * Record/packet header in first mbuf of chain; valid only if M_PKTHDR is set.
  */
 struct pkthdr {
-	struct ifnet	*rcvif;		/* rcv interface */
+	uint32_t	 rcvif_idx;	/* rcv interface index */
+	uint32_t	 rcvif_unique;  /* rcv interface unique id */
 	/* variables for ip and tcp reassembly */
 	void		*header;	/* pointer to packet header */
 	int		 len;		/* total packet length */
@@ -852,7 +853,7 @@
 struct mbuf	*m_copyup(struct mbuf *n, int len, int dstoff);
 struct mbuf	*m_defrag(struct mbuf *, int);
 void		 m_demote(struct mbuf *, int);
-struct mbuf	*m_devget(char *, int, int, struct ifnet *,
+struct mbuf	*m_devget(char *, int, int,
 		    void (*)(char *, caddr_t, u_int));
 struct mbuf	*m_dup(struct mbuf *, int);
 int		 m_dup_pkthdr(struct mbuf *, struct mbuf *, int);
@@ -873,6 +874,13 @@
 struct mbuf	*m_uiotombuf(struct uio *, int, int, int, int);
 struct mbuf	*m_unshare(struct mbuf *, int how);
 
+/*
+ * Look up an ifnet using index + unique stored in mbuf header.
+ */
+struct ifnet	*mbuf_rcvif(struct mbuf *m);
+struct ifnet	*mbuf_rcvif_ref(struct mbuf *m);
+void		m_set_rcvif(struct mbuf *m, struct ifnet *ifp);
+ 
 /*-
  * Network packets may have annotations attached by affixing a list of
  * "packet tags" to the pkthdr structure.  Packet tags are dynamically