- add dom_if{attach,detach} framework.

- transition to use ifp->if_afdata.

Obtained from:	KAME

21 files changed, 313 insertions, 297 deletions

diff --git a/sys/net/if.c b/sys/net/if.c
index 6f3091b..9423d29 100644
--- a/sys/net/if.c
+++ b/sys/net/if.c
@@ -54,6 +54,7 @@
 #include <sys/sockio.h>
 #include <sys/syslog.h>
 #include <sys/sysctl.h>
+#include <sys/domain.h>
 #include <sys/jail.h>
 #include <machine/stdarg.h>
 
@@ -78,6 +79,8 @@
 #include <netinet/if_ether.h>
 #endif
 
+static void	if_attachdomain(void *);
+static void	if_attachdomain1(struct ifnet *);
 static int	ifconf(u_long, caddr_t);
 static void	if_grow(void);
 static void	if_init(void *);
@@ -442,10 +445,48 @@ if_attach(ifp)
 	}
 	ifp->if_broadcastaddr = 0; /* reliably crash if used uninitialized */
 
+	if (domains)
+		if_attachdomain1(ifp);
+
 	/* Announce the interface. */
 	rt_ifannouncemsg(ifp, IFAN_ARRIVAL);
 }
 
+static void
+if_attachdomain(dummy)
+	void *dummy;
+{
+	struct ifnet *ifp;
+	int s;
+
+	s = splnet();
+	for (ifp = TAILQ_FIRST(&ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list))
+		if_attachdomain1(ifp);
+	splx(s);
+}
+SYSINIT(domainifattach, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_FIRST,
+    if_attachdomain, NULL);
+
+static void
+if_attachdomain1(ifp)
+	struct ifnet *ifp;
+{
+	struct domain *dp;
+	int s;
+
+	s = splnet();
+
+	/* address family dependent data region */
+	bzero(ifp->if_afdata, sizeof(ifp->if_afdata));
+	for (dp = domains; dp; dp = dp->dom_next) {
+		if (dp->dom_ifattach)
+			ifp->if_afdata[dp->dom_family] =
+			    (*dp->dom_ifattach)(ifp);
+	}
+
+	splx(s);
+}
+
 /*
  * Detach an interface, removing it from the
  * list of "active" interfaces.
@@ -458,6 +499,7 @@ if_detach(ifp)
 	struct radix_node_head	*rnh;
 	int s;
 	int i;
+	struct domain *dp;
 
 	/*
 	 * Remove routes and flush queues.
@@ -538,6 +580,12 @@ if_detach(ifp)
 	/* Announce that the interface is gone. */
 	rt_ifannouncemsg(ifp, IFAN_DEPARTURE);
 
+	for (dp = domains; dp; dp = dp->dom_next) {
+		if (dp->dom_ifdetach && ifp->if_afdata[dp->dom_family])
+			(*dp->dom_ifdetach)(ifp,
+			    ifp->if_afdata[dp->dom_family]);
+	}
+
 #ifdef MAC
 	mac_destroy_ifnet(ifp);
 #endif /* MAC */
diff --git a/sys/net/if_var.h b/sys/net/if_var.h
index 4c95804..a1dc0b6 100644
--- a/sys/net/if_var.h
+++ b/sys/net/if_var.h
@@ -178,6 +178,8 @@ struct ifnet {
 	struct	ifprefixhead if_prefixhead; /* list of prefixes per if */
 	u_int8_t *if_broadcastaddr;	/* linklevel broadcast bytestring */
 	struct	label if_label;		/* interface MAC label */
+
+	void	*if_afdata[AF_MAX];
 };
 
 typedef void if_init_f_t(void *);
diff --git a/sys/netinet/icmp6.h b/sys/netinet/icmp6.h
index 5d7ca8b..2d29006 100644
--- a/sys/netinet/icmp6.h
+++ b/sys/netinet/icmp6.h
@@ -649,11 +649,8 @@ void	icmp6_mtudisc_update(struct ip6ctlparam *, int);
 /* XXX: is this the right place for these macros? */
 #define icmp6_ifstat_inc(ifp, tag) \
 do {								\
-	if ((ifp) && (ifp)->if_index <= if_index			\
-	 && (ifp)->if_index < icmp6_ifstatmax			\
-	 && icmp6_ifstat && icmp6_ifstat[(ifp)->if_index]) {	\
-		icmp6_ifstat[(ifp)->if_index]->tag++;		\
-	}							\
+	if (ifp)						\
+		((struct in6_ifextra *)((ifp)->if_afdata[AF_INET6]))->icmp6_ifstat->tag++; \
 } while (/*CONSTCOND*/ 0)
 
 #define icmp6_ifoutstat_inc(ifp, type, code) \
@@ -661,7 +658,7 @@ do { \
 		icmp6_ifstat_inc(ifp, ifs6_out_msg); \
  		if (type < ICMP6_INFOMSG_MASK) \
  			icmp6_ifstat_inc(ifp, ifs6_out_error); \
-		switch(type) { \
+		switch (type) { \
 		 case ICMP6_DST_UNREACH: \
 			 icmp6_ifstat_inc(ifp, ifs6_out_dstunreach); \
 			 if (code == ICMP6_DST_UNREACH_ADMIN) \
diff --git a/sys/netinet/tcp_input.c b/sys/netinet/tcp_input.c
index 54a87bc..9d8d733 100644
--- a/sys/netinet/tcp_input.c
+++ b/sys/netinet/tcp_input.c
@@ -2712,8 +2712,7 @@ tcp_mss(tp, offer)
 		mss = rt->rt_rmx.rmx_mtu - min_protoh;
 	else {
 		if (isipv6) {
-			mss = nd_ifinfo[rt->rt_ifp->if_index].linkmtu -
-				min_protoh;
+			mss = ND_IFINFO(rt->rt_ifp)->linkmtu - min_protoh;
 			if (!in6_localaddr(&inp->in6p_faddr))
 				mss = min(mss, tcp_v6mssdflt);
 		} else {
diff --git a/sys/netinet/tcp_reass.c b/sys/netinet/tcp_reass.c
index 54a87bc..9d8d733 100644
--- a/sys/netinet/tcp_reass.c
+++ b/sys/netinet/tcp_reass.c
@@ -2712,8 +2712,7 @@ tcp_mss(tp, offer)
 		mss = rt->rt_rmx.rmx_mtu - min_protoh;
 	else {
 		if (isipv6) {
-			mss = nd_ifinfo[rt->rt_ifp->if_index].linkmtu -
-				min_protoh;
+			mss = ND_IFINFO(rt->rt_ifp)->linkmtu - min_protoh;
 			if (!in6_localaddr(&inp->in6p_faddr))
 				mss = min(mss, tcp_v6mssdflt);
 		} else {
diff --git a/sys/netinet6/icmp6.c b/sys/netinet6/icmp6.c
index 32d01ce..642b7bd 100644
--- a/sys/netinet6/icmp6.c
+++ b/sys/netinet6/icmp6.c
@@ -2158,7 +2158,7 @@ icmp6_reflect(m, off)
 	ip6->ip6_nxt = IPPROTO_ICMPV6;
 	if (m->m_pkthdr.rcvif) {
 		/* XXX: This may not be the outgoing interface */
-		ip6->ip6_hlim = nd_ifinfo[m->m_pkthdr.rcvif->if_index].chlim;
+		ip6->ip6_hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim;
 	} else
 		ip6->ip6_hlim = ip6_defhlim;
 
diff --git a/sys/netinet6/in6.c b/sys/netinet6/in6.c
index b3b6feb..9faa341 100644
--- a/sys/netinet6/in6.c
+++ b/sys/netinet6/in6.c
@@ -420,14 +420,14 @@ in6_control(so, cmd, data, ifp, td)
 	case SIOCSSCOPE6:
 		if (!privileged)
 			return (EPERM);
-		return (scope6_set(ifp, ifr->ifr_ifru.ifru_scope_id));
-		break;
+		return (scope6_set(ifp,
+		    (struct scope6_id *)ifr->ifr_ifru.ifru_scope_id));
 	case SIOCGSCOPE6:
-		return (scope6_get(ifp, ifr->ifr_ifru.ifru_scope_id));
-		break;
+		return (scope6_get(ifp,
+		    (struct scope6_id *)ifr->ifr_ifru.ifru_scope_id));
 	case SIOCGSCOPE6DEF:
-		return (scope6_get_default(ifr->ifr_ifru.ifru_scope_id));
-		break;
+		return (scope6_get_default((struct scope6_id *)
+		    ifr->ifr_ifru.ifru_scope_id));
 	}
 
 	switch (cmd) {
@@ -560,28 +560,19 @@ in6_control(so, cmd, data, ifp, td)
 		break;
 
 	case SIOCGIFSTAT_IN6:
-		if (ifp == NULL)
-			return EINVAL;
-		if (in6_ifstat == NULL || ifp->if_index >= in6_ifstatmax
-		 || in6_ifstat[ifp->if_index] == NULL) {
-			/* return EAFNOSUPPORT? */
-			bzero(&ifr->ifr_ifru.ifru_stat,
-			    sizeof(ifr->ifr_ifru.ifru_stat));
-		} else
-			ifr->ifr_ifru.ifru_stat = *in6_ifstat[ifp->if_index];
+		bzero(&ifr->ifr_ifru.ifru_stat,
+		    sizeof(ifr->ifr_ifru.ifru_stat));
+		ifr->ifr_ifru.ifru_stat =
+		    *((struct in6_ifextra *)ifp->if_afdata[AF_INET6])->in6_ifstat;
 		break;
 
 	case SIOCGIFSTAT_ICMP6:
 		if (ifp == NULL)
 			return EINVAL;
-		if (icmp6_ifstat == NULL || ifp->if_index >= icmp6_ifstatmax ||
-		    icmp6_ifstat[ifp->if_index] == NULL) {
-			/* return EAFNOSUPPORT? */
-			bzero(&ifr->ifr_ifru.ifru_stat,
-			    sizeof(ifr->ifr_ifru.ifru_icmp6stat));
-		} else
-			ifr->ifr_ifru.ifru_icmp6stat =
-				*icmp6_ifstat[ifp->if_index];
+		bzero(&ifr->ifr_ifru.ifru_stat,
+		    sizeof(ifr->ifr_ifru.ifru_icmp6stat));
+		ifr->ifr_ifru.ifru_icmp6stat =
+		    *((struct in6_ifextra *)ifp->if_afdata[AF_INET6])->icmp6_ifstat;
 		break;
 
 	case SIOCGIFALIFETIME_IN6:
@@ -1110,13 +1101,6 @@ in6_update_ifa(ifp, ifra, ia)
 		ia->ia6_lifetime.ia6t_preferred = 0;
 
 	/*
-	 * make sure to initialize ND6 information.  this is to workaround
-	 * issues with interfaces with IPv6 addresses, which have never brought
-	 * up.  We are assuming that it is safe to nd6_ifattach multiple times.
-	 */
-	nd6_ifattach(ifp);
-
-	/*
 	 * Perform DAD, if needed.
 	 * XXX It may be of use, if we can administratively
 	 * disable DAD.
@@ -2341,14 +2325,51 @@ in6_setmaxmtu()
 	IFNET_RLOCK();
 	for (ifp = TAILQ_FIRST(&ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list)) {
 		if ((ifp->if_flags & IFF_LOOPBACK) == 0 &&
-		    nd_ifinfo[ifp->if_index].linkmtu > maxmtu)
-			maxmtu =  nd_ifinfo[ifp->if_index].linkmtu;
+		    ND_IFINFO(ifp)->linkmtu > maxmtu)
+			maxmtu =  ND_IFINFO(ifp)->linkmtu;
 	}
 	IFNET_RUNLOCK();
 	if (maxmtu)	     /* update only when maxmtu is positive */
 		in6_maxmtu = maxmtu;
 }
 
+void *
+in6_domifattach(ifp)
+	struct ifnet *ifp;
+{
+	struct in6_ifextra *ext;
+
+	ext = (struct in6_ifextra *)malloc(sizeof(*ext), M_IFADDR, M_WAITOK);
+	bzero(ext, sizeof(*ext));
+
+	ext->in6_ifstat = (struct in6_ifstat *)malloc(sizeof(struct in6_ifstat),
+	    M_IFADDR, M_WAITOK);
+	bzero(ext->in6_ifstat, sizeof(*ext->in6_ifstat));
+
+	ext->icmp6_ifstat =
+	    (struct icmp6_ifstat *)malloc(sizeof(struct icmp6_ifstat),
+	    M_IFADDR, M_WAITOK);
+	bzero(ext->icmp6_ifstat, sizeof(*ext->icmp6_ifstat));
+
+	ext->nd_ifinfo = nd6_ifattach(ifp);
+	ext->scope6_id = scope6_ifattach(ifp);
+	return ext;
+}
+
+void
+in6_domifdetach(ifp, aux)
+	struct ifnet *ifp;
+	void *aux;
+{
+	struct in6_ifextra *ext = (struct in6_ifextra *)aux;
+
+	scope6_ifdetach(ext->scope6_id);
+	nd6_ifdetach(ext->nd_ifinfo);
+	free(ext->in6_ifstat, M_IFADDR);
+	free(ext->icmp6_ifstat, M_IFADDR);
+	free(ext, M_IFADDR);
+}
+
 /*
  * Convert sockaddr_in6 to sockaddr_in.  Original sockaddr_in6 must be
  * v4 mapped addr or v4 compat addr
diff --git a/sys/netinet6/in6_ifattach.c b/sys/netinet6/in6_ifattach.c
index 6b9707c..7e6f4c7 100644
--- a/sys/netinet6/in6_ifattach.c
+++ b/sys/netinet6/in6_ifattach.c
@@ -60,10 +60,6 @@
 
 #include <net/net_osdep.h>
 
-struct in6_ifstat **in6_ifstat = NULL;
-struct icmp6_ifstat **icmp6_ifstat = NULL;
-size_t in6_ifstatmax = 0;
-size_t icmp6_ifstatmax = 0;
 unsigned long in6_maxmtu = 0;
 
 #ifdef IP6_AUTO_LINKLOCAL
@@ -727,7 +723,6 @@ in6_ifattach(ifp, altifp)
 	struct ifnet *ifp;
 	struct ifnet *altifp;	/* secondary EUI64 source */
 {
-	static size_t if_indexlim = 8;
 	struct in6_ifaddr *ia;
 	struct in6_addr in6;
 
@@ -740,50 +735,6 @@ in6_ifattach(ifp, altifp)
 	}
 
 	/*
-	 * We have some arrays that should be indexed by if_index.
-	 * since if_index will grow dynamically, they should grow too.
-	 *	struct in6_ifstat **in6_ifstat
-	 *	struct icmp6_ifstat **icmp6_ifstat
-	 */
-	if (in6_ifstat == NULL || icmp6_ifstat == NULL ||
-	    if_index >= if_indexlim) {
-		size_t n;
-		caddr_t q;
-		size_t olim;
-
-		olim = if_indexlim;
-		while (if_index >= if_indexlim)
-			if_indexlim <<= 1;
-
-		/* grow in6_ifstat */
-		n = if_indexlim * sizeof(struct in6_ifstat *);
-		q = (caddr_t)malloc(n, M_IFADDR, M_WAITOK);
-		bzero(q, n);
-		if (in6_ifstat) {
-			bcopy((caddr_t)in6_ifstat, q,
-				olim * sizeof(struct in6_ifstat *));
-			free((caddr_t)in6_ifstat, M_IFADDR);
-		}
-		in6_ifstat = (struct in6_ifstat **)q;
-		in6_ifstatmax = if_indexlim;
-
-		/* grow icmp6_ifstat */
-		n = if_indexlim * sizeof(struct icmp6_ifstat *);
-		q = (caddr_t)malloc(n, M_IFADDR, M_WAITOK);
-		bzero(q, n);
-		if (icmp6_ifstat) {
-			bcopy((caddr_t)icmp6_ifstat, q,
-				olim * sizeof(struct icmp6_ifstat *));
-			free((caddr_t)icmp6_ifstat, M_IFADDR);
-		}
-		icmp6_ifstat = (struct icmp6_ifstat **)q;
-		icmp6_ifstatmax = if_indexlim;
-	}
-
-	/* initialize scope identifiers */
-	scope6_ifattach(ifp);
-
-	/*
 	 * quirks based on interface type
 	 */
 	switch (ifp->if_type) {
@@ -844,20 +795,6 @@ statinit:
 	/* update dynamically. */
 	if (in6_maxmtu < ifp->if_mtu)
 		in6_maxmtu = ifp->if_mtu;
-
-	if (in6_ifstat[ifp->if_index] == NULL) {
-		in6_ifstat[ifp->if_index] = (struct in6_ifstat *)
-			malloc(sizeof(struct in6_ifstat), M_IFADDR, M_WAITOK);
-		bzero(in6_ifstat[ifp->if_index], sizeof(struct in6_ifstat));
-	}
-	if (icmp6_ifstat[ifp->if_index] == NULL) {
-		icmp6_ifstat[ifp->if_index] = (struct icmp6_ifstat *)
-			malloc(sizeof(struct icmp6_ifstat), M_IFADDR, M_WAITOK);
-		bzero(icmp6_ifstat[ifp->if_index], sizeof(struct icmp6_ifstat));
-	}
-
-	/* initialize NDP variables */
-	nd6_ifattach(ifp);
 }
 
 /*
@@ -987,7 +924,7 @@ in6_get_tmpifid(ifp, retbuf, baseid, generate)
 	int generate;
 {
 	u_int8_t nullbuf[8];
-	struct nd_ifinfo *ndi = &nd_ifinfo[ifp->if_index];
+	struct nd_ifinfo *ndi = ND_IFINFO(ifp);
 
 	bzero(nullbuf, sizeof(nullbuf));
 	if (bcmp(ndi->randomid, nullbuf, sizeof(nullbuf)) == 0) {
@@ -1009,9 +946,9 @@ void
 in6_tmpaddrtimer(ignored_arg)
 	void *ignored_arg;
 {
-	int i;
 	struct nd_ifinfo *ndi;
 	u_int8_t nullbuf[8];
+	struct ifnet *ifp;
 	int s = splnet();
 
 	callout_reset(&in6_tmpaddrtimer_ch,
@@ -1019,8 +956,8 @@ in6_tmpaddrtimer(ignored_arg)
 	    ip6_temp_regen_advance) * hz, in6_tmpaddrtimer, NULL);
 
 	bzero(nullbuf, sizeof(nullbuf));
-	for (i = 1; i < if_index + 1; i++) {
-		ndi = &nd_ifinfo[i];
+	for (ifp = TAILQ_FIRST(&ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list)) {
+		ndi = ND_IFINFO(ifp);
 		if (bcmp(ndi->randomid, nullbuf, sizeof(nullbuf)) != 0) {
 			/*
 			 * We've been generating a random ID on this interface.
diff --git a/sys/netinet6/in6_proto.c b/sys/netinet6/in6_proto.c
index 893dba2..7f477a6 100644
--- a/sys/netinet6/in6_proto.c
+++ b/sys/netinet6/in6_proto.c
@@ -264,7 +264,8 @@ struct domain inet6domain =
       (struct protosw *)&inet6sw[sizeof(inet6sw)/sizeof(inet6sw[0])], 0,
       in6_inithead,
       offsetof(struct sockaddr_in6, sin6_addr) << 3,
-      sizeof(struct sockaddr_in6) };
+      sizeof(struct sockaddr_in6),
+      in6_domifattach, in6_domifdetach, };
 
 DOMAIN_SET(inet6);
 
diff --git a/sys/netinet6/in6_src.c b/sys/netinet6/in6_src.c
index c2acf30..6f81fe7 100644
--- a/sys/netinet6/in6_src.c
+++ b/sys/netinet6/in6_src.c
@@ -300,7 +300,7 @@ in6_selecthlim(in6p, ifp)
 	if (in6p && in6p->in6p_hops >= 0)
 		return (in6p->in6p_hops);
 	else if (ifp)
-		return (nd_ifinfo[ifp->if_index].chlim);
+		return (ND_IFINFO(ifp)->chlim);
 	else
 		return (ip6_defhlim);
 }
diff --git a/sys/netinet6/in6_var.h b/sys/netinet6/in6_var.h
index 0042eec..098eb9f 100644
--- a/sys/netinet6/in6_var.h
+++ b/sys/netinet6/in6_var.h
@@ -90,6 +90,15 @@ struct in6_addrlifetime {
 	u_int32_t ia6t_pltime;	/* prefix lifetime */
 };
 
+struct nd_ifinfo;
+struct scope6_id;
+struct in6_ifextra {
+	struct in6_ifstat *in6_ifstat;
+	struct icmp6_ifstat *icmp6_ifstat;
+	struct nd_ifinfo *nd_ifinfo;
+	struct scope6_id *scope6_id;
+};
+
 struct	in6_ifaddr {
 	struct	ifaddr ia_ifa;		/* protocol-independent info */
 #define	ia_ifp		ia_ifa.ifa_ifp
@@ -445,18 +454,11 @@ struct	in6_rrenumreq {
 #ifdef _KERNEL
 extern struct in6_ifaddr *in6_ifaddr;
 
-extern struct in6_ifstat **in6_ifstat;
-extern size_t in6_ifstatmax;
 extern struct icmp6stat icmp6stat;
-extern struct icmp6_ifstat **icmp6_ifstat;
-extern size_t icmp6_ifstatmax;
 #define in6_ifstat_inc(ifp, tag) \
 do {								\
-	if ((ifp) && (ifp)->if_index <= if_index		\
-	 && (ifp)->if_index < in6_ifstatmax			\
-	 && in6_ifstat && in6_ifstat[(ifp)->if_index]) {	\
-		in6_ifstat[(ifp)->if_index]->tag++;		\
-	}							\
+	if (ifp)						\
+		((struct in6_ifextra *)((ifp)->if_afdata[AF_INET6]))->in6_ifstat->tag++; \
 } while (/*CONSTCOND*/ 0)
 
 extern struct in6_addr zeroin6_addr;
@@ -576,6 +578,8 @@ void	in6_purgeaddr __P((struct ifaddr *));
 int	in6if_do_dad __P((struct ifnet *));
 void	in6_purgeif __P((struct ifnet *));
 void	in6_savemkludge __P((struct in6_ifaddr *));
+void	*in6_domifattach __P((struct ifnet *));
+void	in6_domifdetach __P((struct ifnet *, void *));
 void	in6_setmaxmtu   __P((void));
 void	in6_restoremkludge __P((struct in6_ifaddr *, struct ifnet *));
 void	in6_purgemkludge __P((struct ifnet *));
diff --git a/sys/netinet6/ip6_input.c b/sys/netinet6/ip6_input.c
index 01bd0ca..8062ffe 100644
--- a/sys/netinet6/ip6_input.c
+++ b/sys/netinet6/ip6_input.c
@@ -106,6 +106,7 @@
 #include <netinet6/ip6_var.h>
 #include <netinet/in_pcb.h>
 #include <netinet/icmp6.h>
+#include <netinet6/scope6_var.h>
 #include <netinet6/in6_ifattach.h>
 #include <netinet6/nd6.h>
 #include <netinet6/in6_prefix.h>
@@ -196,6 +197,7 @@ ip6_init()
 	ip6intrq.ifq_maxlen = ip6qmaxlen;
 	mtx_init(&ip6intrq.ifq_mtx, "ip6_inq", NULL, MTX_DEF);
 	netisr_register(NETISR_IPV6, ip6_input, &ip6intrq);
+	scope6_init();
 	nd6_init();
 	frag6_init();
 #ifndef RANDOM_IP_ID
@@ -209,12 +211,6 @@ ip6_init2(dummy)
 	void *dummy;
 {
 
-	/*
-	 * to route local address of p2p link to loopback,
-	 * assign loopback address first.
-	 */
-	in6_ifattach(&loif[0], NULL);
-
 	/* nd6_timer_init */
 	callout_init(&nd6_timer_ch, 0);
 	callout_reset(&nd6_timer_ch, hz, nd6_timer, NULL);
diff --git a/sys/netinet6/ip6_output.c b/sys/netinet6/ip6_output.c
index 55eb3c3..1f0c0cc 100644
--- a/sys/netinet6/ip6_output.c
+++ b/sys/netinet6/ip6_output.c
@@ -794,7 +794,7 @@ skip_ipsec2:;
 		}
 	}
 	if (ro_pmtu->ro_rt != NULL) {
-		u_int32_t ifmtu = nd_ifinfo[ifp->if_index].linkmtu;
+		u_int32_t ifmtu = ND_IFINFO(ifp)->linkmtu;
 
 		mtu = ro_pmtu->ro_rt->rt_rmx.rmx_mtu;
 		if (mtu > ifmtu || mtu == 0) {
@@ -814,7 +814,7 @@ skip_ipsec2:;
 				 ro_pmtu->ro_rt->rt_rmx.rmx_mtu = mtu; /* XXX */
 		}
 	} else {
-		mtu = nd_ifinfo[ifp->if_index].linkmtu;
+		mtu = ND_IFINFO(ifp)->linkmtu;
 	}
 
 	/*
diff --git a/sys/netinet6/nd6.c b/sys/netinet6/nd6.c
index be14f33..e091dee 100644
--- a/sys/netinet6/nd6.c
+++ b/sys/netinet6/nd6.c
@@ -98,14 +98,13 @@ int nd6_debug = 0;
 static int nd6_inuse, nd6_allocated;
 
 struct llinfo_nd6 llinfo_nd6 = {&llinfo_nd6, &llinfo_nd6};
-static size_t nd_ifinfo_indexlim = 8;
-struct nd_ifinfo *nd_ifinfo = NULL;
 struct nd_drhead nd_defrouter;
 struct nd_prhead nd_prefix = { 0 };
 
 int nd6_recalc_reachtm_interval = ND6_RECALC_REACHTM_INTERVAL;
 static struct sockaddr_in6 all1_sa;
 
+static void nd6_setmtu0 __P((struct ifnet *, struct nd_ifinfo *));
 static void nd6_slowtimo __P((void *));
 static int regen_tmpaddr __P((struct in6_ifaddr *));
 
@@ -139,59 +138,42 @@ nd6_init()
 	    nd6_slowtimo, NULL);
 }
 
-void
+struct nd_ifinfo *
 nd6_ifattach(ifp)
 	struct ifnet *ifp;
 {
+	struct nd_ifinfo *nd;
 
-	/*
-	 * We have some arrays that should be indexed by if_index.
-	 * since if_index will grow dynamically, they should grow too.
-	 */
-	if (nd_ifinfo == NULL || if_index >= nd_ifinfo_indexlim) {
-		size_t n;
-		caddr_t q;
-
-		while (if_index >= nd_ifinfo_indexlim)
-			nd_ifinfo_indexlim <<= 1;
-
-		/* grow nd_ifinfo */
-		n = nd_ifinfo_indexlim * sizeof(struct nd_ifinfo);
-		q = (caddr_t)malloc(n, M_IP6NDP, M_WAITOK);
-		bzero(q, n);
-		if (nd_ifinfo) {
-			bcopy((caddr_t)nd_ifinfo, q, n/2);
-			free((caddr_t)nd_ifinfo, M_IP6NDP);
-		}
-		nd_ifinfo = (struct nd_ifinfo *)q;
-	}
+	nd = (struct nd_ifinfo *)malloc(sizeof(*nd), M_IP6NDP, M_WAITOK);
+	bzero(nd, sizeof(*nd));
 
-#define ND nd_ifinfo[ifp->if_index]
-
-	/*
-	 * Don't initialize if called twice.
-	 * XXX: to detect this, we should choose a member that is never set
-	 * before initialization of the ND structure itself.  We formaly used
-	 * the linkmtu member, which was not suitable because it could be 
-	 * initialized via "ifconfig mtu".
-	 */
-	if (ND.basereachable)
-		return;
+	nd->initialized = 1;
 
-	ND.linkmtu = ifnet_byindex(ifp->if_index)->if_mtu;
-	ND.chlim = IPV6_DEFHLIM;
-	ND.basereachable = REACHABLE_TIME;
-	ND.reachable = ND_COMPUTE_RTIME(ND.basereachable);
-	ND.retrans = RETRANS_TIMER;
-	ND.receivedra = 0;
+	nd->linkmtu = ifnet_byindex(ifp->if_index)->if_mtu;
+	nd->chlim = IPV6_DEFHLIM;
+	nd->basereachable = REACHABLE_TIME;
+	nd->reachable = ND_COMPUTE_RTIME(nd->basereachable);
+	nd->retrans = RETRANS_TIMER;
+	nd->receivedra = 0;
 	/*
 	 * Note that the default value of ip6_accept_rtadv is 0, which means
 	 * we won't accept RAs by default even if we set ND6_IFF_ACCEPT_RTADV
 	 * here.
 	 */
-	ND.flags = (ND6_IFF_PERFORMNUD | ND6_IFF_ACCEPT_RTADV);
-	nd6_setmtu(ifp);
-#undef ND
+	nd->flags = (ND6_IFF_PERFORMNUD | ND6_IFF_ACCEPT_RTADV);
+
+	/* XXX: we cannot call nd6_setmtu since ifp is not fully initialized */
+	nd6_setmtu0(ifp, nd);
+
+	return nd;
+}
+
+void
+nd6_ifdetach(nd)
+	struct nd_ifinfo *nd;
+{
+
+	free(nd, M_IP6NDP);
 }
 
 /*
@@ -202,9 +184,21 @@ void
 nd6_setmtu(ifp)
 	struct ifnet *ifp;
 {
-	struct nd_ifinfo *ndi = &nd_ifinfo[ifp->if_index];
-	u_long oldmaxmtu = ndi->maxmtu;
-	u_long oldlinkmtu = ndi->linkmtu;
+
+	nd6_setmtu0(ifp, ND_IFINFO(ifp));
+}
+
+/* XXX todo: do not maintain copy of ifp->if_mtu in ndi->maxmtu */
+void
+nd6_setmtu0(ifp, ndi)
+	struct ifnet *ifp;
+	struct nd_ifinfo *ndi;
+{
+	u_long oldmaxmtu;
+	u_long oldlinkmtu;
+
+	oldmaxmtu = ndi->maxmtu;
+	oldlinkmtu = ndi->linkmtu;
 
 	switch (ifp->if_type) {
 	case IFT_ARCNET:	/* XXX MTU handling needs more work */
@@ -446,7 +440,7 @@ nd6_timer(ignored_arg)
 			ln = next;
 			continue;
 		}
-		ndi = &nd_ifinfo[ifp->if_index];
+		ndi = ND_IFINFO(ifp);
 		dst = (struct sockaddr_in6 *)rt_key(rt);
 
 		if (ln->ln_expire > time_second) {
@@ -468,7 +462,7 @@ nd6_timer(ignored_arg)
 			if (ln->ln_asked < nd6_mmaxtries) {
 				ln->ln_asked++;
 				ln->ln_expire = time_second +
-					nd_ifinfo[ifp->if_index].retrans / 1000;
+					ND_IFINFO(ifp)->retrans / 1000;
 				nd6_ns_output(ifp, NULL, &dst->sin6_addr,
 					ln, 0);
 			} else {
@@ -523,7 +517,7 @@ nd6_timer(ignored_arg)
 			if (ln->ln_asked < nd6_umaxtries) {
 				ln->ln_asked++;
 				ln->ln_expire = time_second +
-					nd_ifinfo[ifp->if_index].retrans / 1000;
+					ND_IFINFO(ifp)->retrans / 1000;
 				nd6_ns_output(ifp, &dst->sin6_addr,
 					       &dst->sin6_addr, ln, 0);
 			} else {
@@ -1079,7 +1073,7 @@ nd6_nud_hint(rt, dst6, force)
 	ln->ln_state = ND6_LLINFO_REACHABLE;
 	if (ln->ln_expire)
 		ln->ln_expire = time_second +
-			nd_ifinfo[rt->rt_ifp->if_index].reachable;
+			ND_IFINFO(rt->rt_ifp)->reachable;
 }
 
 void
@@ -1453,35 +1447,23 @@ nd6_ioctl(cmd, data, ifp)
 
 		break;
 	case OSIOCGIFINFO_IN6:
-		if (!nd_ifinfo || i >= nd_ifinfo_indexlim) {
-			error = EINVAL;
-			break;
-		}
-		ndi->ndi.linkmtu = nd_ifinfo[ifp->if_index].linkmtu;
-		ndi->ndi.maxmtu = nd_ifinfo[ifp->if_index].maxmtu;
-		ndi->ndi.basereachable =
-		    nd_ifinfo[ifp->if_index].basereachable;
-		ndi->ndi.reachable = nd_ifinfo[ifp->if_index].reachable;
-		ndi->ndi.retrans = nd_ifinfo[ifp->if_index].retrans;
-		ndi->ndi.flags = nd_ifinfo[ifp->if_index].flags;
-		ndi->ndi.recalctm = nd_ifinfo[ifp->if_index].recalctm;
-		ndi->ndi.chlim = nd_ifinfo[ifp->if_index].chlim;
-		ndi->ndi.receivedra = nd_ifinfo[ifp->if_index].receivedra;
+		/* XXX: old ndp(8) assumes a positive value for linkmtu. */
+		bzero(&ndi->ndi, sizeof(ndi->ndi));
+		ndi->ndi.linkmtu = ND_IFINFO(ifp)->linkmtu;
+		ndi->ndi.maxmtu = ND_IFINFO(ifp)->maxmtu;
+		ndi->ndi.basereachable = ND_IFINFO(ifp)->basereachable;
+		ndi->ndi.reachable = ND_IFINFO(ifp)->reachable;
+		ndi->ndi.retrans = ND_IFINFO(ifp)->retrans;
+		ndi->ndi.flags = ND_IFINFO(ifp)->flags;
+		ndi->ndi.recalctm = ND_IFINFO(ifp)->recalctm;
+		ndi->ndi.chlim = ND_IFINFO(ifp)->chlim;
+		ndi->ndi.receivedra = ND_IFINFO(ifp)->receivedra;
 		break;
 	case SIOCGIFINFO_IN6:
-		if (!nd_ifinfo || i >= nd_ifinfo_indexlim) {
-			error = EINVAL;
-			break;
-		}
-		ndi->ndi = nd_ifinfo[ifp->if_index];
+		ndi->ndi = *ND_IFINFO(ifp);
 		break;
 	case SIOCSIFINFO_FLAGS:
-		/* XXX: almost all other fields of ndi->ndi is unused */
-		if (!nd_ifinfo || i >= nd_ifinfo_indexlim) {
-			error = EINVAL;
-			break;
-		}
-		nd_ifinfo[ifp->if_index].flags = ndi->ndi.flags;
+		ND_IFINFO(ifp)->flags = ndi->ndi.flags;
 		break;
 	case SIOCSNDFLUSH_IN6:	/* XXX: the ioctl name is confusing... */
 		/* flush default router list */
@@ -1824,15 +1806,13 @@ nd6_slowtimo(ignored_arg)
     void *ignored_arg;
 {
 	int s = splnet();
-	int i;
 	struct nd_ifinfo *nd6if;
+	struct ifnet *ifp;
 
 	callout_reset(&nd6_slowtimo_ch, ND6_SLOWTIMER_INTERVAL * hz,
 	    nd6_slowtimo, NULL);
-	for (i = 1; i < if_index + 1; i++) {
-		if (!nd_ifinfo || i >= nd_ifinfo_indexlim)
-			continue;
-		nd6if = &nd_ifinfo[i];
+	for (ifp = TAILQ_FIRST(&ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list)) {
+		nd6if = ND_IFINFO(ifp);
 		if (nd6if->basereachable && /* already initialized */
 		    (nd6if->recalctm -= ND6_SLOWTIMER_INTERVAL) <= 0) {
 			/*
@@ -1946,7 +1926,7 @@ nd6_output(ifp, origifp, m0, dst, rt0)
 	}
 	if (!ln || !rt) {
 		if ((ifp->if_flags & IFF_POINTOPOINT) == 0 &&
-		    !(nd_ifinfo[ifp->if_index].flags & ND6_IFF_PERFORMNUD)) {
+		    !(ND_IFINFO(ifp)->flags & ND6_IFF_PERFORMNUD)) {
 			log(LOG_DEBUG,
 			    "nd6_output: can't allocate llinfo for %s "
 			    "(ln=%p, rt=%p)\n",
@@ -2004,7 +1984,7 @@ nd6_output(ifp, origifp, m0, dst, rt0)
 		    ln->ln_expire < time_second) {
 			ln->ln_asked++;
 			ln->ln_expire = time_second +
-				nd_ifinfo[ifp->if_index].retrans / 1000;
+				ND_IFINFO(ifp)->retrans / 1000;
 			nd6_ns_output(ifp, NULL, &dst->sin6_addr, ln, 0);
 		}
 	}
diff --git a/sys/netinet6/nd6.h b/sys/netinet6/nd6.h
index e8bf02e..2ee4a48 100644
--- a/sys/netinet6/nd6.h
+++ b/sys/netinet6/nd6.h
@@ -80,6 +80,7 @@ struct nd_ifinfo {
 	int recalctm;			/* BaseReacable re-calculation timer */
 	u_int8_t chlim;			/* CurHopLimit */
 	u_int8_t receivedra;
+	u_int8_t initialized; /* Flag to see the entry is initialized */
 	/* the following 3 members are for privacy extension for addrconf */
 	u_int8_t randomseed0[8]; /* upper 64 bits of MD5 digest */
 	u_int8_t randomseed1[8]; /* lower 64 bits (usually the EUI64 IFID) */
@@ -89,6 +90,16 @@ struct nd_ifinfo {
 #define ND6_IFF_PERFORMNUD	0x1
 #define ND6_IFF_ACCEPT_RTADV	0x2
 
+#ifdef _KERNEL
+#define ND_IFINFO(ifp) \
+	(((struct in6_ifextra *)(ifp)->if_afdata[AF_INET6])->nd_ifinfo)
+#define IN6_LINKMTU(ifp) \
+	((ND_IFINFO(ifp)->linkmtu && ND_IFINFO(ifp)->linkmtu < (ifp)->if_mtu) \
+	    ? ND_IFINFO(ifp)->linkmtu \
+	    : ((ND_IFINFO(ifp)->maxmtu && ND_IFINFO(ifp)->maxmtu < (ifp)->if_mtu) \
+		? ND_IFINFO(ifp)->maxmtu : (ifp)->if_mtu))
+#endif
+
 struct in6_nbrinfo {
 	char ifname[IFNAMSIZ];	/* if name, e.g. "en0" */
 	struct in6_addr addr;	/* IPv6 address of the neighbor */
@@ -341,7 +352,8 @@ union nd_opts {
 /* XXX: need nd6_var.h?? */
 /* nd6.c */
 void nd6_init __P((void));
-void nd6_ifattach __P((struct ifnet *));
+struct nd_ifinfo *nd6_ifattach __P((struct ifnet *));
+void nd6_ifdetach __P((struct nd_ifinfo *));
 int nd6_is_addr_neighbor __P((struct sockaddr_in6 *, struct ifnet *));
 void nd6_option_init __P((void *, int, union nd_opts *));
 struct nd_opt_hdr *nd6_option __P((union nd_opts *));
diff --git a/sys/netinet6/nd6_nbr.c b/sys/netinet6/nd6_nbr.c
index 7a56bad..0cac161 100644
--- a/sys/netinet6/nd6_nbr.c
+++ b/sys/netinet6/nd6_nbr.c
@@ -641,7 +641,7 @@ nd6_na_input(m, off, icmp6len)
 			ln->ln_byhint = 0;
 			if (ln->ln_expire) {
 				ln->ln_expire = time_second +
-				    nd_ifinfo[rt->rt_ifp->if_index].reachable;
+				    ND_IFINFO(rt->rt_ifp)->reachable;
 			}
 		} else {
 			ln->ln_state = ND6_LLINFO_STALE;
@@ -723,7 +723,7 @@ nd6_na_input(m, off, icmp6len)
 				ln->ln_byhint = 0;
 				if (ln->ln_expire) {
 					ln->ln_expire = time_second +
-					    nd_ifinfo[ifp->if_index].reachable;
+					    ND_IFINFO(ifp)->reachable;
 				}
 			} else {
 				if (lladdr && llchange) {
@@ -1081,8 +1081,8 @@ nd6_dad_start(ifa, tick)
 	dp->dad_ns_ocount = dp->dad_ns_tcount = 0;
 	if (tick == NULL) {
 		nd6_dad_ns_output(dp, ifa);
-		nd6_dad_starttimer(dp, 
-		    nd_ifinfo[ifa->ifa_ifp->if_index].retrans * hz / 1000);
+		nd6_dad_starttimer(dp,
+		    ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000);
 	} else {
 		int ntick;
 
@@ -1174,7 +1174,7 @@ nd6_dad_timer(ifa)
 		 */
 		nd6_dad_ns_output(dp, ifa);
 		nd6_dad_starttimer(dp,
-		    nd_ifinfo[ifa->ifa_ifp->if_index].retrans * hz / 1000);
+		    ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000);
 	} else {
 		/*
 		 * We have transmitted sufficient number of DAD packets.
diff --git a/sys/netinet6/nd6_rtr.c b/sys/netinet6/nd6_rtr.c
index 65d219d..bf50a7c 100644
--- a/sys/netinet6/nd6_rtr.c
+++ b/sys/netinet6/nd6_rtr.c
@@ -202,7 +202,7 @@ nd6_ra_input(m, off, icmp6len)
 	int off, icmp6len;
 {
 	struct ifnet *ifp = m->m_pkthdr.rcvif;
-	struct nd_ifinfo *ndi = &nd_ifinfo[ifp->if_index];
+	struct nd_ifinfo *ndi = ND_IFINFO(ifp);
 	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
 	struct nd_router_advert *nd_ra;
 	struct in6_addr saddr6 = ip6->ip6_src;
diff --git a/sys/netinet6/scope6.c b/sys/netinet6/scope6.c
index 1e6c135..fbb681a 100644
--- a/sys/netinet6/scope6.c
+++ b/sys/netinet6/scope6.c
@@ -45,77 +45,61 @@
 #include <netinet6/in6_var.h>
 #include <netinet6/scope6_var.h>
 
-struct scope6_id {
-	/*
-	 * 16 is correspondent to 4bit multicast scope field.
-	 * i.e. from node-local to global with some reserved/unassigned types.
-	 */
-	u_int32_t s6id_list[16];
-};
-static size_t if_indexlim = 8;
-struct scope6_id *scope6_ids = NULL;
+static struct scope6_id sid_default;
+#define SID(ifp) \
+	(((struct in6_ifextra *)(ifp)->if_afdata[AF_INET6])->scope6_id)
 
 void
+scope6_init()
+{
+
+	bzero(&sid_default, sizeof(sid_default));
+}
+
+struct scope6_id *
 scope6_ifattach(ifp)
 	struct ifnet *ifp;
 {
 	int s = splnet();
+	struct scope6_id *sid;
 
-	/*
-	 * We have some arrays that should be indexed by if_index.
-	 * since if_index will grow dynamically, they should grow too.
-	 */
-	if (scope6_ids == NULL || if_index >= if_indexlim) {
-		size_t n;
-		caddr_t q;
-
-		while (if_index >= if_indexlim)
-			if_indexlim <<= 1;
-
-		/* grow scope index array */
-		n = if_indexlim * sizeof(struct scope6_id);
-		/* XXX: need new malloc type? */
-		q = (caddr_t)malloc(n, M_IFADDR, M_WAITOK);
-		bzero(q, n);
-		if (scope6_ids) {
-			bcopy((caddr_t)scope6_ids, q, n/2);
-			free((caddr_t)scope6_ids, M_IFADDR);
-		}
-		scope6_ids = (struct scope6_id *)q;
-	}
-
-#define SID scope6_ids[ifp->if_index]
-
-	/* don't initialize if called twice */
-	if (SID.s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL]) {
-		splx(s);
-		return;
-	}
+	sid = (struct scope6_id *)malloc(sizeof(*sid), M_IFADDR, M_WAITOK);
+	bzero(sid, sizeof(*sid));
 
 	/*
 	 * XXX: IPV6_ADDR_SCOPE_xxx macros are not standard.
 	 * Should we rather hardcode here?
 	 */
-	SID.s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL] = ifp->if_index;
+	sid->s6id_list[IPV6_ADDR_SCOPE_NODELOCAL] = ifp->if_index;
+	sid->s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL] = ifp->if_index;
 #ifdef MULTI_SCOPE
 	/* by default, we don't care about scope boundary for these scopes. */
-	SID.s6id_list[IPV6_ADDR_SCOPE_SITELOCAL] = 1;
-	SID.s6id_list[IPV6_ADDR_SCOPE_ORGLOCAL] = 1;
+	sid->s6id_list[IPV6_ADDR_SCOPE_SITELOCAL] = 1;
+	sid->s6id_list[IPV6_ADDR_SCOPE_ORGLOCAL] = 1;
 #endif
-#undef SID
 
 	splx(s);
+	return sid;
+}
+
+void
+scope6_ifdetach(sid)
+	struct scope6_id *sid;
+{
+
+	free(sid, M_IFADDR);
 }
 
 int
 scope6_set(ifp, idlist)
 	struct ifnet *ifp;
-	u_int32_t *idlist;
+	struct scope6_id *idlist;
 {
 	int i, s;
 	int error = 0;
+	struct scope6_id *sid = SID(ifp);
 
-	if (scope6_ids == NULL)	/* paranoid? */
+	if (!sid)	/* paranoid? */
 		return (EINVAL);
 
 	/*
@@ -131,10 +115,10 @@ scope6_set(ifp, idlist)
 	s = splnet();
 
 	for (i = 0; i < 16; i++) {
-		if (idlist[i] &&
-		    idlist[i] != scope6_ids[ifp->if_index].s6id_list[i]) {
+		if (idlist->s6id_list[i] &&
+		    idlist->s6id_list[i] != sid->s6id_list[i]) {
 			if (i == IPV6_ADDR_SCOPE_LINKLOCAL &&
-			    idlist[i] > if_index) {
+			    idlist->s6id_list[i] > if_index) {
 				/*
 				 * XXX: theoretically, there should be no
 				 * relationship between link IDs and interface
@@ -150,7 +134,7 @@ scope6_set(ifp, idlist)
 			 * but we simply set the new value in this initial
 			 * implementation.
 			 */
-			scope6_ids[ifp->if_index].s6id_list[i] = idlist[i];
+			sid->s6id_list[i] = idlist->s6id_list[i];
 		}
 	}
 	splx(s);
@@ -161,13 +145,14 @@ scope6_set(ifp, idlist)
 int
 scope6_get(ifp, idlist)
 	struct ifnet *ifp;
-	u_int32_t *idlist;
+	struct scope6_id *idlist;
 {
-	if (scope6_ids == NULL)	/* paranoid? */
+	struct scope6_id *sid = SID(ifp);
+
+	if (sid == NULL)	/* paranoid? */
 		return (EINVAL);
 
-	bcopy(scope6_ids[ifp->if_index].s6id_list, idlist,
-	      sizeof(scope6_ids[ifp->if_index].s6id_list));
+	*idlist = *sid;
 
 	return (0);
 }
@@ -237,31 +222,45 @@ in6_addr2scopeid(ifp, addr)
 	struct ifnet *ifp;	/* must not be NULL */
 	struct in6_addr *addr;	/* must not be NULL */
 {
-	int scope = in6_addrscope(addr);
+	int scope;
+	struct scope6_id *sid = SID(ifp);
+
+#ifdef DIAGNOSTIC
+	if (sid == NULL) { /* should not happen */
+		panic("in6_addr2zoneid: scope array is NULL");
+		/* NOTREACHED */
+	}
+#endif
+
+	/*
+	 * special case: the loopback address can only belong to a loopback
+	 * interface.
+	 */
+	if (IN6_IS_ADDR_LOOPBACK(addr)) {
+		if (!(ifp->if_flags & IFF_LOOPBACK))
+			return (-1);
+		else
+			return (0); /* there's no ambiguity */
+	}
 
-	if (scope6_ids == NULL)	/* paranoid? */
-		return (0);	/* XXX */
-	if (ifp->if_index >= if_indexlim)
-		return (0);	/* XXX */
+	scope = in6_addrscope(addr);
 
-#define SID scope6_ids[ifp->if_index]
 	switch(scope) {
 	case IPV6_ADDR_SCOPE_NODELOCAL:
 		return (-1);	/* XXX: is this an appropriate value? */
 
 	case IPV6_ADDR_SCOPE_LINKLOCAL:
-		return (SID.s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL]);
+		return (sid->s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL]);
 
 	case IPV6_ADDR_SCOPE_SITELOCAL:
-		return (SID.s6id_list[IPV6_ADDR_SCOPE_SITELOCAL]);
+		return (sid->s6id_list[IPV6_ADDR_SCOPE_SITELOCAL]);
 
 	case IPV6_ADDR_SCOPE_ORGLOCAL:
-		return (SID.s6id_list[IPV6_ADDR_SCOPE_ORGLOCAL]);
+		return (sid->s6id_list[IPV6_ADDR_SCOPE_ORGLOCAL]);
 
 	default:
 		return (0);	/* XXX: treat as global. */
 	}
-#undef SID
 }
 
 void
@@ -269,28 +268,27 @@ scope6_setdefault(ifp)
 	struct ifnet *ifp;	/* note that this might be NULL */
 {
 	/*
-	 * Currently, this function just set the default "link" according to
-	 * the given interface.
+	 * Currently, this function just set the default "interfaces"
+	 * and "links" according to the given interface.
 	 * We might eventually have to separate the notion of "link" from
 	 * "interface" and provide a user interface to set the default.
 	 */
 	if (ifp) {
-		scope6_ids[0].s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL] =
+		sid_default.s6id_list[IPV6_ADDR_SCOPE_NODELOCAL] =
+			ifp->if_index;
+		sid_default.s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL] =
 			ifp->if_index;
 	} else {
-		scope6_ids[0].s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL] = 0;
+		sid_default.s6id_list[IPV6_ADDR_SCOPE_NODELOCAL] = 0;
+		sid_default.s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL] = 0;
 	}
 }
 
 int
 scope6_get_default(idlist)
-	u_int32_t *idlist;
+	struct scope6_id *idlist;
 {
-	if (scope6_ids == NULL)	/* paranoid? */
-		return (EINVAL);
-
-	bcopy(scope6_ids[0].s6id_list, idlist,
-	      sizeof(scope6_ids[0].s6id_list));
+	*idlist = sid_default;
 
 	return (0);
 }
@@ -299,5 +297,12 @@ u_int32_t
 scope6_addr2default(addr)
 	struct in6_addr *addr;
 {
-	return (scope6_ids[0].s6id_list[in6_addrscope(addr)]);
+	/*
+	 * special case: The loopback address should be considered as
+	 * link-local, but there's no ambiguity in the syntax.
+	 */
+	if (IN6_IS_ADDR_LOOPBACK(addr))
+		return (0);
+
+	return (sid_default.s6id_list[in6_addrscope(addr)]);
 }
diff --git a/sys/netinet6/scope6_var.h b/sys/netinet6/scope6_var.h
index b4eda9c..0744d48 100644
--- a/sys/netinet6/scope6_var.h
+++ b/sys/netinet6/scope6_var.h
@@ -34,11 +34,21 @@
 #define _NETINET6_SCOPE6_VAR_H_
 
 #ifdef _KERNEL
-void	scope6_ifattach __P((struct ifnet *));
-int	scope6_set __P((struct ifnet *, u_int32_t *));
-int	scope6_get __P((struct ifnet *, u_int32_t *));
+struct scope6_id {
+	/*
+	 * 16 is correspondent to 4bit multicast scope field.
+	 * i.e. from node-local to global with some reserved/unassigned types.
+	 */
+	u_int32_t s6id_list[16];
+};
+
+void	scope6_init __P((void));
+struct scope6_id *scope6_ifattach __P((struct ifnet *));
+void	scope6_ifdetach __P((struct scope6_id *));
+int	scope6_set __P((struct ifnet *, struct scope6_id *));
+int	scope6_get __P((struct ifnet *, struct scope6_id *));
 void	scope6_setdefault __P((struct ifnet *));
-int	scope6_get_default __P((u_int32_t *));
+int	scope6_get_default __P((struct scope6_id *));
 u_int32_t scope6_in6_addrscope __P((struct in6_addr *));
 u_int32_t scope6_addr2default __P((struct in6_addr *));
 #endif /* _KERNEL */
diff --git a/sys/sys/domain.h b/sys/sys/domain.h
index 77b8ad8..b5e29c9 100644
--- a/sys/sys/domain.h
+++ b/sys/sys/domain.h
@@ -45,6 +45,7 @@
  * Forward structure declarations for function prototypes [sic].
  */
 struct	mbuf;
+struct	ifnet;
 
 struct domain {
 	int	dom_family;		/* AF_xxx */
@@ -61,6 +62,9 @@ struct domain {
 		(void **, int);
 	int	dom_rtoffset;		/* an arg to rtattach, in bits */
 	int	dom_maxrtkey;		/* for routing layer */
+	void	*(*dom_ifattach)(struct ifnet *);
+	void	(*dom_ifdetach)(struct ifnet *, void *);
+					/* af-dependent data on ifnet */
 };
 
 #ifdef _KERNEL
diff --git a/sys/sys/kernel.h b/sys/sys/kernel.h
index f8a5423..fe75bf2 100644
--- a/sys/sys/kernel.h
+++ b/sys/sys/kernel.h
@@ -151,6 +151,7 @@ enum sysinit_sub_id {
 	SI_SUB_PROTO_BEGIN	= 0x8000000,	/* XXX: set splimp (kludge)*/
 	SI_SUB_PROTO_IF		= 0x8400000,	/* interfaces*/
 	SI_SUB_PROTO_DOMAIN	= 0x8800000,	/* domains (address families?)*/
+	SI_SUB_PROTO_IFATTACHDOMAIN	= 0x8800001,	/* domain dependent data init*/
 	SI_SUB_PROTO_END	= 0x8ffffff,	/* XXX: set splx (kludge)*/
 	SI_SUB_KPROF		= 0x9000000,	/* kernel profiling*/
 	SI_SUB_KICK_SCHEDULER	= 0xa000000,	/* start the timeout events*/