Initial import

Code is based on FreeBSD 8.2 with USB support from Sebastian Huber
and Thomas Doerfler. Initial TCP/IP stack work is from Kevel Kirspel.

1 files changed, 2162 insertions, 0 deletions

diff --git a/rtems/freebsd/netinet6/nd6_rtr.c b/rtems/freebsd/netinet6/nd6_rtr.c
new file mode 100644
index 00000000..04992096
--- /dev/null
+++ b/rtems/freebsd/netinet6/nd6_rtr.c
@@ -0,0 +1,2162 @@
+#include <rtems/freebsd/machine/rtems-bsd-config.h>
+
+/*-
+ * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the project nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	$KAME: nd6_rtr.c,v 1.111 2001/04/27 01:37:15 jinmei Exp $
+ */
+
+#include <rtems/freebsd/sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <rtems/freebsd/local/opt_inet.h>
+#include <rtems/freebsd/local/opt_inet6.h>
+
+#include <rtems/freebsd/sys/param.h>
+#include <rtems/freebsd/sys/systm.h>
+#include <rtems/freebsd/sys/malloc.h>
+#include <rtems/freebsd/sys/mbuf.h>
+#include <rtems/freebsd/sys/socket.h>
+#include <rtems/freebsd/sys/sockio.h>
+#include <rtems/freebsd/sys/time.h>
+#include <rtems/freebsd/sys/kernel.h>
+#include <rtems/freebsd/sys/lock.h>
+#include <rtems/freebsd/sys/errno.h>
+#include <rtems/freebsd/sys/rwlock.h>
+#include <rtems/freebsd/sys/syslog.h>
+#include <rtems/freebsd/sys/queue.h>
+
+#include <rtems/freebsd/net/if.h>
+#include <rtems/freebsd/net/if_types.h>
+#include <rtems/freebsd/net/if_dl.h>
+#include <rtems/freebsd/net/route.h>
+#include <rtems/freebsd/net/radix.h>
+#include <rtems/freebsd/net/vnet.h>
+
+#include <rtems/freebsd/netinet/in.h>
+#include <rtems/freebsd/net/if_llatbl.h>
+#include <rtems/freebsd/netinet6/in6_var.h>
+#include <rtems/freebsd/netinet6/in6_ifattach.h>
+#include <rtems/freebsd/netinet/ip6.h>
+#include <rtems/freebsd/netinet6/ip6_var.h>
+#include <rtems/freebsd/netinet6/nd6.h>
+#include <rtems/freebsd/netinet/icmp6.h>
+#include <rtems/freebsd/netinet6/scope6_var.h>
+
+static int rtpref(struct nd_defrouter *);
+static struct nd_defrouter *defrtrlist_update(struct nd_defrouter *);
+static int prelist_update __P((struct nd_prefixctl *, struct nd_defrouter *,
+    struct mbuf *, int));
+static struct in6_ifaddr *in6_ifadd(struct nd_prefixctl *,	int);
+static struct nd_pfxrouter *pfxrtr_lookup __P((struct nd_prefix *,
+	struct nd_defrouter *));
+static void pfxrtr_add(struct nd_prefix *, struct nd_defrouter *);
+static void pfxrtr_del(struct nd_pfxrouter *);
+static struct nd_pfxrouter *find_pfxlist_reachable_router
+(struct nd_prefix *);
+static void defrouter_delreq(struct nd_defrouter *);
+static void nd6_rtmsg(int, struct rtentry *);
+
+static int in6_init_prefix_ltimes(struct nd_prefix *);
+static void in6_init_address_ltimes __P((struct nd_prefix *,
+	struct in6_addrlifetime *));
+
+static int rt6_deleteroute(struct radix_node *, void *);
+
+VNET_DECLARE(int, nd6_recalc_reachtm_interval);
+#define	V_nd6_recalc_reachtm_interval	VNET(nd6_recalc_reachtm_interval)
+
+static VNET_DEFINE(struct ifnet *, nd6_defifp);
+VNET_DEFINE(int, nd6_defifindex);
+#define	V_nd6_defifp			VNET(nd6_defifp)
+
+VNET_DEFINE(int, ip6_use_tempaddr) = 0;
+
+VNET_DEFINE(int, ip6_desync_factor);
+VNET_DEFINE(u_int32_t, ip6_temp_preferred_lifetime) = DEF_TEMP_PREFERRED_LIFETIME;
+VNET_DEFINE(u_int32_t, ip6_temp_valid_lifetime) = DEF_TEMP_VALID_LIFETIME;
+
+VNET_DEFINE(int, ip6_temp_regen_advance) = TEMPADDR_REGEN_ADVANCE;
+
+/* RTPREF_MEDIUM has to be 0! */
+#define RTPREF_HIGH	1
+#define RTPREF_MEDIUM	0
+#define RTPREF_LOW	(-1)
+#define RTPREF_RESERVED	(-2)
+#define RTPREF_INVALID	(-3)	/* internal */
+
+/*
+ * Receive Router Solicitation Message - just for routers.
+ * Router solicitation/advertisement is mostly managed by userland program
+ * (rtadvd) so here we have no function like nd6_ra_output().
+ *
+ * Based on RFC 2461
+ */
+void
+nd6_rs_input(struct mbuf *m, int off, int icmp6len)
+{
+	struct ifnet *ifp = m->m_pkthdr.rcvif;
+	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
+	struct nd_router_solicit *nd_rs;
+	struct in6_addr saddr6 = ip6->ip6_src;
+	char *lladdr = NULL;
+	int lladdrlen = 0;
+	union nd_opts ndopts;
+	char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
+
+	/* If I'm not a router, ignore it. */
+	if (V_ip6_accept_rtadv != 0 || V_ip6_forwarding != 1)
+		goto freeit;
+
+	/* Sanity checks */
+	if (ip6->ip6_hlim != 255) {
+		nd6log((LOG_ERR,
+		    "nd6_rs_input: invalid hlim (%d) from %s to %s on %s\n",
+		    ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src),
+		    ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp)));
+		goto bad;
+	}
+
+	/*
+	 * Don't update the neighbor cache, if src = ::.
+	 * This indicates that the src has no IP address assigned yet.
+	 */
+	if (IN6_IS_ADDR_UNSPECIFIED(&saddr6))
+		goto freeit;
+
+#ifndef PULLDOWN_TEST
+	IP6_EXTHDR_CHECK(m, off, icmp6len,);
+	nd_rs = (struct nd_router_solicit *)((caddr_t)ip6 + off);
+#else
+	IP6_EXTHDR_GET(nd_rs, struct nd_router_solicit *, m, off, icmp6len);
+	if (nd_rs == NULL) {
+		ICMP6STAT_INC(icp6s_tooshort);
+		return;
+	}
+#endif
+
+	icmp6len -= sizeof(*nd_rs);
+	nd6_option_init(nd_rs + 1, icmp6len, &ndopts);
+	if (nd6_options(&ndopts) < 0) {
+		nd6log((LOG_INFO,
+		    "nd6_rs_input: invalid ND option, ignored\n"));
+		/* nd6_options have incremented stats */
+		goto freeit;
+	}
+
+	if (ndopts.nd_opts_src_lladdr) {
+		lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1);
+		lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3;
+	}
+
+	if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
+		nd6log((LOG_INFO,
+		    "nd6_rs_input: lladdrlen mismatch for %s "
+		    "(if %d, RS packet %d)\n",
+		    ip6_sprintf(ip6bufs, &saddr6),
+		    ifp->if_addrlen, lladdrlen - 2));
+		goto bad;
+	}
+
+	nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, ND_ROUTER_SOLICIT, 0);
+
+ freeit:
+	m_freem(m);
+	return;
+
+ bad:
+	ICMP6STAT_INC(icp6s_badrs);
+	m_freem(m);
+}
+
+/*
+ * Receive Router Advertisement Message.
+ *
+ * Based on RFC 2461
+ * TODO: on-link bit on prefix information
+ * TODO: ND_RA_FLAG_{OTHER,MANAGED} processing
+ */
+void
+nd6_ra_input(struct mbuf *m, int off, int icmp6len)
+{
+	struct ifnet *ifp = m->m_pkthdr.rcvif;
+	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;
+	int mcast = 0;
+	union nd_opts ndopts;
+	struct nd_defrouter *dr;
+	char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
+
+	/*
+	 * We only accept RAs only when
+	 * the system-wide variable allows the acceptance, and
+	 * per-interface variable allows RAs on the receiving interface.
+	 */
+	if (V_ip6_accept_rtadv == 0)
+		goto freeit;
+	if (!(ndi->flags & ND6_IFF_ACCEPT_RTADV))
+		goto freeit;
+
+	if (ip6->ip6_hlim != 255) {
+		nd6log((LOG_ERR,
+		    "nd6_ra_input: invalid hlim (%d) from %s to %s on %s\n",
+		    ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src),
+		    ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp)));
+		goto bad;
+	}
+
+	if (!IN6_IS_ADDR_LINKLOCAL(&saddr6)) {
+		nd6log((LOG_ERR,
+		    "nd6_ra_input: src %s is not link-local\n",
+		    ip6_sprintf(ip6bufs, &saddr6)));
+		goto bad;
+	}
+
+#ifndef PULLDOWN_TEST
+	IP6_EXTHDR_CHECK(m, off, icmp6len,);
+	nd_ra = (struct nd_router_advert *)((caddr_t)ip6 + off);
+#else
+	IP6_EXTHDR_GET(nd_ra, struct nd_router_advert *, m, off, icmp6len);
+	if (nd_ra == NULL) {
+		ICMP6STAT_INC(icp6s_tooshort);
+		return;
+	}
+#endif
+
+	icmp6len -= sizeof(*nd_ra);
+	nd6_option_init(nd_ra + 1, icmp6len, &ndopts);
+	if (nd6_options(&ndopts) < 0) {
+		nd6log((LOG_INFO,
+		    "nd6_ra_input: invalid ND option, ignored\n"));
+		/* nd6_options have incremented stats */
+		goto freeit;
+	}
+
+    {
+	struct nd_defrouter dr0;
+	u_int32_t advreachable = nd_ra->nd_ra_reachable;
+
+	/* remember if this is a multicasted advertisement */
+	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst))
+		mcast = 1;
+
+	bzero(&dr0, sizeof(dr0));
+	dr0.rtaddr = saddr6;
+	dr0.flags  = nd_ra->nd_ra_flags_reserved;
+	dr0.rtlifetime = ntohs(nd_ra->nd_ra_router_lifetime);
+	dr0.expire = time_second + dr0.rtlifetime;
+	dr0.ifp = ifp;
+	/* unspecified or not? (RFC 2461 6.3.4) */
+	if (advreachable) {
+		advreachable = ntohl(advreachable);
+		if (advreachable <= MAX_REACHABLE_TIME &&
+		    ndi->basereachable != advreachable) {
+			ndi->basereachable = advreachable;
+			ndi->reachable = ND_COMPUTE_RTIME(ndi->basereachable);
+			ndi->recalctm = V_nd6_recalc_reachtm_interval; /* reset */
+		}
+	}
+	if (nd_ra->nd_ra_retransmit)
+		ndi->retrans = ntohl(nd_ra->nd_ra_retransmit);
+	if (nd_ra->nd_ra_curhoplimit)
+		ndi->chlim = nd_ra->nd_ra_curhoplimit;
+	dr = defrtrlist_update(&dr0);
+    }
+
+	/*
+	 * prefix
+	 */
+	if (ndopts.nd_opts_pi) {
+		struct nd_opt_hdr *pt;
+		struct nd_opt_prefix_info *pi = NULL;
+		struct nd_prefixctl pr;
+
+		for (pt = (struct nd_opt_hdr *)ndopts.nd_opts_pi;
+		     pt <= (struct nd_opt_hdr *)ndopts.nd_opts_pi_end;
+		     pt = (struct nd_opt_hdr *)((caddr_t)pt +
+						(pt->nd_opt_len << 3))) {
+			if (pt->nd_opt_type != ND_OPT_PREFIX_INFORMATION)
+				continue;
+			pi = (struct nd_opt_prefix_info *)pt;
+
+			if (pi->nd_opt_pi_len != 4) {
+				nd6log((LOG_INFO,
+				    "nd6_ra_input: invalid option "
+				    "len %d for prefix information option, "
+				    "ignored\n", pi->nd_opt_pi_len));
+				continue;
+			}
+
+			if (128 < pi->nd_opt_pi_prefix_len) {
+				nd6log((LOG_INFO,
+				    "nd6_ra_input: invalid prefix "
+				    "len %d for prefix information option, "
+				    "ignored\n", pi->nd_opt_pi_prefix_len));
+				continue;
+			}
+
+			if (IN6_IS_ADDR_MULTICAST(&pi->nd_opt_pi_prefix)
+			 || IN6_IS_ADDR_LINKLOCAL(&pi->nd_opt_pi_prefix)) {
+				nd6log((LOG_INFO,
+				    "nd6_ra_input: invalid prefix "
+				    "%s, ignored\n",
+				    ip6_sprintf(ip6bufs,
+					&pi->nd_opt_pi_prefix)));
+				continue;
+			}
+
+			bzero(&pr, sizeof(pr));
+			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_raf_onlink = (pi->nd_opt_pi_flags_reserved &
+			    ND_OPT_PI_FLAG_ONLINK) ? 1 : 0;
+			pr.ndpr_raf_auto = (pi->nd_opt_pi_flags_reserved &
+			    ND_OPT_PI_FLAG_AUTO) ? 1 : 0;
+			pr.ndpr_plen = pi->nd_opt_pi_prefix_len;
+			pr.ndpr_vltime = ntohl(pi->nd_opt_pi_valid_time);
+			pr.ndpr_pltime = ntohl(pi->nd_opt_pi_preferred_time);
+			(void)prelist_update(&pr, dr, m, mcast);
+		}
+	}
+
+	/*
+	 * MTU
+	 */
+	if (ndopts.nd_opts_mtu && ndopts.nd_opts_mtu->nd_opt_mtu_len == 1) {
+		u_long mtu;
+		u_long maxmtu;
+
+		mtu = (u_long)ntohl(ndopts.nd_opts_mtu->nd_opt_mtu_mtu);
+
+		/* lower bound */
+		if (mtu < IPV6_MMTU) {
+			nd6log((LOG_INFO, "nd6_ra_input: bogus mtu option "
+			    "mtu=%lu sent from %s, ignoring\n",
+			    mtu, ip6_sprintf(ip6bufs, &ip6->ip6_src)));
+			goto skip;
+		}
+
+		/* upper bound */
+		maxmtu = (ndi->maxmtu && ndi->maxmtu < ifp->if_mtu)
+		    ? ndi->maxmtu : ifp->if_mtu;
+		if (mtu <= maxmtu) {
+			int change = (ndi->linkmtu != mtu);
+
+			ndi->linkmtu = mtu;
+			if (change) /* in6_maxmtu may change */
+				in6_setmaxmtu();
+		} else {
+			nd6log((LOG_INFO, "nd6_ra_input: bogus mtu "
+			    "mtu=%lu sent from %s; "
+			    "exceeds maxmtu %lu, ignoring\n",
+			    mtu, ip6_sprintf(ip6bufs, &ip6->ip6_src), maxmtu));
+		}
+	}
+
+ skip:
+
+	/*
+	 * Source link layer address
+	 */
+    {
+	char *lladdr = NULL;
+	int lladdrlen = 0;
+
+	if (ndopts.nd_opts_src_lladdr) {
+		lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1);
+		lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3;
+	}
+
+	if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
+		nd6log((LOG_INFO,
+		    "nd6_ra_input: lladdrlen mismatch for %s "
+		    "(if %d, RA packet %d)\n", ip6_sprintf(ip6bufs, &saddr6),
+		    ifp->if_addrlen, lladdrlen - 2));
+		goto bad;
+	}
+
+	nd6_cache_lladdr(ifp, &saddr6, lladdr,
+	    lladdrlen, ND_ROUTER_ADVERT, 0);
+
+	/*
+	 * Installing a link-layer address might change the state of the
+	 * router's neighbor cache, which might also affect our on-link
+	 * detection of adveritsed prefixes.
+	 */
+	pfxlist_onlink_check();
+    }
+
+ freeit:
+	m_freem(m);
+	return;
+
+ bad:
+	ICMP6STAT_INC(icp6s_badra);
+	m_freem(m);
+}
+
+/*
+ * default router list proccessing sub routines
+ */
+
+/* tell the change to user processes watching the routing socket. */
+static void
+nd6_rtmsg(int cmd, struct rtentry *rt)
+{
+	struct rt_addrinfo info;
+	struct ifnet *ifp;
+	struct ifaddr *ifa;
+
+	bzero((caddr_t)&info, sizeof(info));
+	info.rti_info[RTAX_DST] = rt_key(rt);
+	info.rti_info[RTAX_GATEWAY] = rt->rt_gateway;
+	info.rti_info[RTAX_NETMASK] = rt_mask(rt);
+	ifp = rt->rt_ifp;
+	if (ifp != NULL) {
+		IF_ADDR_LOCK(ifp);
+		ifa = TAILQ_FIRST(&ifp->if_addrhead);
+		info.rti_info[RTAX_IFP] = ifa->ifa_addr;
+		ifa_ref(ifa);
+		IF_ADDR_UNLOCK(ifp);
+		info.rti_info[RTAX_IFA] = rt->rt_ifa->ifa_addr;
+	} else
+		ifa = NULL;
+
+	rt_missmsg(cmd, &info, rt->rt_flags, 0);
+	if (ifa != NULL)
+		ifa_free(ifa);
+}
+
+void
+defrouter_addreq(struct nd_defrouter *new)
+{
+	struct sockaddr_in6 def, mask, gate;
+	struct rtentry *newrt = NULL;
+	int s;
+	int error;
+
+	bzero(&def, sizeof(def));
+	bzero(&mask, sizeof(mask));
+	bzero(&gate, sizeof(gate));
+
+	def.sin6_len = mask.sin6_len = gate.sin6_len =
+	    sizeof(struct sockaddr_in6);
+	def.sin6_family = gate.sin6_family = AF_INET6;
+	gate.sin6_addr = new->rtaddr;
+
+	s = splnet();
+	error = rtrequest(RTM_ADD, (struct sockaddr *)&def,
+	    (struct sockaddr *)&gate, (struct sockaddr *)&mask,
+	    RTF_GATEWAY, &newrt);
+	if (newrt) {
+		nd6_rtmsg(RTM_ADD, newrt); /* tell user process */
+		RTFREE(newrt);
+	}
+	if (error == 0)
+		new->installed = 1;
+	splx(s);
+	return;
+}
+
+struct nd_defrouter *
+defrouter_lookup(struct in6_addr *addr, struct ifnet *ifp)
+{
+	struct nd_defrouter *dr;
+
+	for (dr = TAILQ_FIRST(&V_nd_defrouter); dr;
+	     dr = TAILQ_NEXT(dr, dr_entry)) {
+		if (dr->ifp == ifp && IN6_ARE_ADDR_EQUAL(addr, &dr->rtaddr))
+			return (dr);
+	}
+
+	return (NULL);		/* search failed */
+}
+
+/*
+ * Remove the default route for a given router.
+ * This is just a subroutine function for defrouter_select(), and should
+ * not be called from anywhere else.
+ */
+static void
+defrouter_delreq(struct nd_defrouter *dr)
+{
+	struct sockaddr_in6 def, mask, gate;
+	struct rtentry *oldrt = NULL;
+
+	bzero(&def, sizeof(def));
+	bzero(&mask, sizeof(mask));
+	bzero(&gate, sizeof(gate));
+
+	def.sin6_len = mask.sin6_len = gate.sin6_len =
+	    sizeof(struct sockaddr_in6);
+	def.sin6_family = gate.sin6_family = AF_INET6;
+	gate.sin6_addr = dr->rtaddr;
+
+	rtrequest(RTM_DELETE, (struct sockaddr *)&def,
+	    (struct sockaddr *)&gate,
+	    (struct sockaddr *)&mask, RTF_GATEWAY, &oldrt);
+	if (oldrt) {
+		nd6_rtmsg(RTM_DELETE, oldrt);
+		RTFREE(oldrt);
+	}
+
+	dr->installed = 0;
+}
+
+/*
+ * remove all default routes from default router list
+ */
+void
+defrouter_reset(void)
+{
+	struct nd_defrouter *dr;
+
+	for (dr = TAILQ_FIRST(&V_nd_defrouter); dr;
+	     dr = TAILQ_NEXT(dr, dr_entry))
+		defrouter_delreq(dr);
+
+	/*
+	 * XXX should we also nuke any default routers in the kernel, by
+	 * going through them by rtalloc1()?
+	 */
+}
+
+void
+defrtrlist_del(struct nd_defrouter *dr)
+{
+	struct nd_defrouter *deldr = NULL;
+	struct nd_prefix *pr;
+
+	/*
+	 * Flush all the routing table entries that use the router
+	 * as a next hop.
+	 */
+	if (!V_ip6_forwarding && V_ip6_accept_rtadv) /* XXX: better condition? */
+		rt6_flush(&dr->rtaddr, dr->ifp);
+
+	if (dr->installed) {
+		deldr = dr;
+		defrouter_delreq(dr);
+	}
+	TAILQ_REMOVE(&V_nd_defrouter, dr, dr_entry);
+
+	/*
+	 * Also delete all the pointers to the router in each prefix lists.
+	 */
+	for (pr = V_nd_prefix.lh_first; pr; pr = pr->ndpr_next) {
+		struct nd_pfxrouter *pfxrtr;
+		if ((pfxrtr = pfxrtr_lookup(pr, dr)) != NULL)
+			pfxrtr_del(pfxrtr);
+	}
+	pfxlist_onlink_check();
+
+	/*
+	 * If the router is the primary one, choose a new one.
+	 * Note that defrouter_select() will remove the current gateway
+	 * from the routing table.
+	 */
+	if (deldr)
+		defrouter_select();
+
+	free(dr, M_IP6NDP);
+}
+
+/*
+ * Default Router Selection according to Section 6.3.6 of RFC 2461 and
+ * draft-ietf-ipngwg-router-selection:
+ * 1) Routers that are reachable or probably reachable should be preferred.
+ *    If we have more than one (probably) reachable router, prefer ones
+ *    with the highest router preference.
+ * 2) When no routers on the list are known to be reachable or
+ *    probably reachable, routers SHOULD be selected in a round-robin
+ *    fashion, regardless of router preference values.
+ * 3) If the Default Router List is empty, assume that all
+ *    destinations are on-link.
+ *
+ * We assume nd_defrouter is sorted by router preference value.
+ * Since the code below covers both with and without router preference cases,
+ * we do not need to classify the cases by ifdef.
+ *
+ * At this moment, we do not try to install more than one default router,
+ * even when the multipath routing is available, because we're not sure about
+ * the benefits for stub hosts comparing to the risk of making the code
+ * complicated and the possibility of introducing bugs.
+ */
+void
+defrouter_select(void)
+{
+	int s = splnet();
+	struct nd_defrouter *dr, *selected_dr = NULL, *installed_dr = NULL;
+	struct llentry *ln = NULL;
+
+	/*
+	 * This function should be called only when acting as an autoconfigured
+	 * host.  Although the remaining part of this function is not effective
+	 * if the node is not an autoconfigured host, we explicitly exclude
+	 * such cases here for safety.
+	 */
+	if (V_ip6_forwarding || !V_ip6_accept_rtadv) {
+		nd6log((LOG_WARNING,
+		    "defrouter_select: called unexpectedly (forwarding=%d, "
+		    "accept_rtadv=%d)\n", V_ip6_forwarding, V_ip6_accept_rtadv));
+		splx(s);
+		return;
+	}
+
+	/*
+	 * Let's handle easy case (3) first:
+	 * If default router list is empty, there's nothing to be done.
+	 */
+	if (!TAILQ_FIRST(&V_nd_defrouter)) {
+		splx(s);
+		return;
+	}
+
+	/*
+	 * Search for a (probably) reachable router from the list.
+	 * We just pick up the first reachable one (if any), assuming that
+	 * the ordering rule of the list described in defrtrlist_update().
+	 */
+	for (dr = TAILQ_FIRST(&V_nd_defrouter); dr;
+	     dr = TAILQ_NEXT(dr, dr_entry)) {
+		IF_AFDATA_LOCK(dr->ifp);
+		if (selected_dr == NULL &&
+		    (ln = nd6_lookup(&dr->rtaddr, 0, dr->ifp)) &&
+		    ND6_IS_LLINFO_PROBREACH(ln)) {
+			selected_dr = dr;
+		}
+		IF_AFDATA_UNLOCK(dr->ifp);
+		if (ln != NULL) {
+			LLE_RUNLOCK(ln);
+			ln = NULL;
+		}
+
+		if (dr->installed && installed_dr == NULL)
+			installed_dr = dr;
+		else if (dr->installed && installed_dr) {
+			/* this should not happen.  warn for diagnosis. */
+			log(LOG_ERR, "defrouter_select: more than one router"
+			    " is installed\n");
+		}
+	}
+	/*
+	 * If none of the default routers was found to be reachable,
+	 * round-robin the list regardless of preference.
+	 * Otherwise, if we have an installed router, check if the selected
+	 * (reachable) router should really be preferred to the installed one.
+	 * We only prefer the new router when the old one is not reachable
+	 * or when the new one has a really higher preference value.
+	 */
+	if (selected_dr == NULL) {
+		if (installed_dr == NULL || !TAILQ_NEXT(installed_dr, dr_entry))
+			selected_dr = TAILQ_FIRST(&V_nd_defrouter);
+		else
+			selected_dr = TAILQ_NEXT(installed_dr, dr_entry);
+	} else if (installed_dr) {
+		IF_AFDATA_LOCK(installed_dr->ifp);
+		if ((ln = nd6_lookup(&installed_dr->rtaddr, 0, installed_dr->ifp)) &&
+		    ND6_IS_LLINFO_PROBREACH(ln) &&
+		    rtpref(selected_dr) <= rtpref(installed_dr)) {
+			selected_dr = installed_dr;
+		}
+		IF_AFDATA_UNLOCK(installed_dr->ifp);
+		if (ln != NULL)
+			LLE_RUNLOCK(ln);
+	}
+
+	/*
+	 * If the selected router is different than the installed one,
+	 * remove the installed router and install the selected one.
+	 * Note that the selected router is never NULL here.
+	 */
+	if (installed_dr != selected_dr) {
+		if (installed_dr)
+			defrouter_delreq(installed_dr);
+		defrouter_addreq(selected_dr);
+	}
+
+	splx(s);
+	return;
+}
+
+/*
+ * for default router selection
+ * regards router-preference field as a 2-bit signed integer
+ */
+static int
+rtpref(struct nd_defrouter *dr)
+{
+	switch (dr->flags & ND_RA_FLAG_RTPREF_MASK) {
+	case ND_RA_FLAG_RTPREF_HIGH:
+		return (RTPREF_HIGH);
+	case ND_RA_FLAG_RTPREF_MEDIUM:
+	case ND_RA_FLAG_RTPREF_RSV:
+		return (RTPREF_MEDIUM);
+	case ND_RA_FLAG_RTPREF_LOW:
+		return (RTPREF_LOW);
+	default:
+		/*
+		 * This case should never happen.  If it did, it would mean a
+		 * serious bug of kernel internal.  We thus always bark here.
+		 * Or, can we even panic?
+		 */
+		log(LOG_ERR, "rtpref: impossible RA flag %x\n", dr->flags);
+		return (RTPREF_INVALID);
+	}
+	/* NOTREACHED */
+}
+
+static struct nd_defrouter *
+defrtrlist_update(struct nd_defrouter *new)
+{
+	struct nd_defrouter *dr, *n;
+	int s = splnet();
+
+	if ((dr = defrouter_lookup(&new->rtaddr, new->ifp)) != NULL) {
+		/* entry exists */
+		if (new->rtlifetime == 0) {
+			defrtrlist_del(dr);
+			dr = NULL;
+		} else {
+			int oldpref = rtpref(dr);
+
+			/* override */
+			dr->flags = new->flags; /* xxx flag check */
+			dr->rtlifetime = new->rtlifetime;
+			dr->expire = new->expire;
+
+			/*
+			 * If the preference does not change, there's no need
+			 * to sort the entries.
+			 */
+			if (rtpref(new) == oldpref) {
+				splx(s);
+				return (dr);
+			}
+
+			/*
+			 * preferred router may be changed, so relocate
+			 * this router.
+			 * XXX: calling TAILQ_REMOVE directly is a bad manner.
+			 * However, since defrtrlist_del() has many side
+			 * effects, we intentionally do so here.
+			 * defrouter_select() below will handle routing
+			 * changes later.
+			 */
+			TAILQ_REMOVE(&V_nd_defrouter, dr, dr_entry);
+			n = dr;
+			goto insert;
+		}
+		splx(s);
+		return (dr);
+	}
+
+	/* entry does not exist */
+	if (new->rtlifetime == 0) {
+		splx(s);
+		return (NULL);
+	}
+
+	n = (struct nd_defrouter *)malloc(sizeof(*n), M_IP6NDP, M_NOWAIT);
+	if (n == NULL) {
+		splx(s);
+		return (NULL);
+	}
+	bzero(n, sizeof(*n));
+	*n = *new;
+
+insert:
+	/*
+	 * Insert the new router in the Default Router List;
+	 * The Default Router List should be in the descending order
+	 * of router-preferece.  Routers with the same preference are
+	 * sorted in the arriving time order.
+	 */
+
+	/* insert at the end of the group */
+	for (dr = TAILQ_FIRST(&V_nd_defrouter); dr;
+	     dr = TAILQ_NEXT(dr, dr_entry)) {
+		if (rtpref(n) > rtpref(dr))
+			break;
+	}
+	if (dr)
+		TAILQ_INSERT_BEFORE(dr, n, dr_entry);
+	else
+		TAILQ_INSERT_TAIL(&V_nd_defrouter, n, dr_entry);
+
+	defrouter_select();
+
+	splx(s);
+
+	return (n);
+}
+
+static struct nd_pfxrouter *
+pfxrtr_lookup(struct nd_prefix *pr, struct nd_defrouter *dr)
+{
+	struct nd_pfxrouter *search;
+
+	for (search = pr->ndpr_advrtrs.lh_first; search; search = search->pfr_next) {
+		if (search->router == dr)
+			break;
+	}
+
+	return (search);
+}
+
+static void
+pfxrtr_add(struct nd_prefix *pr, struct nd_defrouter *dr)
+{
+	struct nd_pfxrouter *new;
+
+	new = (struct nd_pfxrouter *)malloc(sizeof(*new), M_IP6NDP, M_NOWAIT);
+	if (new == NULL)
+		return;
+	bzero(new, sizeof(*new));
+	new->router = dr;
+
+	LIST_INSERT_HEAD(&pr->ndpr_advrtrs, new, pfr_entry);
+
+	pfxlist_onlink_check();
+}
+
+static void
+pfxrtr_del(struct nd_pfxrouter *pfr)
+{
+	LIST_REMOVE(pfr, pfr_entry);
+	free(pfr, M_IP6NDP);
+}
+
+struct nd_prefix *
+nd6_prefix_lookup(struct nd_prefixctl *key)
+{
+	struct nd_prefix *search;
+
+	for (search = V_nd_prefix.lh_first;
+	    search; search = search->ndpr_next) {
+		if (key->ndpr_ifp == search->ndpr_ifp &&
+		    key->ndpr_plen == search->ndpr_plen &&
+		    in6_are_prefix_equal(&key->ndpr_prefix.sin6_addr,
+		    &search->ndpr_prefix.sin6_addr, key->ndpr_plen)) {
+			break;
+		}
+	}
+
+	return (search);
+}
+
+int
+nd6_prelist_add(struct nd_prefixctl *pr, struct nd_defrouter *dr,
+    struct nd_prefix **newp)
+{
+	struct nd_prefix *new = NULL;
+	int error = 0;
+	int i, s;
+	char ip6buf[INET6_ADDRSTRLEN];
+
+	new = (struct nd_prefix *)malloc(sizeof(*new), M_IP6NDP, M_NOWAIT);
+	if (new == NULL)
+		return(ENOMEM);
+	bzero(new, sizeof(*new));
+	new->ndpr_ifp = pr->ndpr_ifp;
+	new->ndpr_prefix = pr->ndpr_prefix;
+	new->ndpr_plen = pr->ndpr_plen;
+	new->ndpr_vltime = pr->ndpr_vltime;
+	new->ndpr_pltime = pr->ndpr_pltime;
+	new->ndpr_flags = pr->ndpr_flags;
+	if ((error = in6_init_prefix_ltimes(new)) != 0) {
+		free(new, M_IP6NDP);
+		return(error);
+	}
+	new->ndpr_lastupdate = time_second;
+	if (newp != NULL)
+		*newp = new;
+
+	/* initialization */
+	LIST_INIT(&new->ndpr_advrtrs);
+	in6_prefixlen2mask(&new->ndpr_mask, new->ndpr_plen);
+	/* make prefix in the canonical form */
+	for (i = 0; i < 4; i++)
+		new->ndpr_prefix.sin6_addr.s6_addr32[i] &=
+		    new->ndpr_mask.s6_addr32[i];
+
+	s = splnet();
+	/* link ndpr_entry to nd_prefix list */
+	LIST_INSERT_HEAD(&V_nd_prefix, new, ndpr_entry);
+	splx(s);
+
+	/* ND_OPT_PI_FLAG_ONLINK processing */
+	if (new->ndpr_raf_onlink) {
+		int e;
+
+		if ((e = nd6_prefix_onlink(new)) != 0) {
+			nd6log((LOG_ERR, "nd6_prelist_add: failed to make "
+			    "the prefix %s/%d on-link on %s (errno=%d)\n",
+			    ip6_sprintf(ip6buf, &pr->ndpr_prefix.sin6_addr),
+			    pr->ndpr_plen, if_name(pr->ndpr_ifp), e));
+			/* proceed anyway. XXX: is it correct? */
+		}
+	}
+
+	if (dr)
+		pfxrtr_add(new, dr);
+
+	return 0;
+}
+
+void
+prelist_remove(struct nd_prefix *pr)
+{
+	struct nd_pfxrouter *pfr, *next;
+	int e, s;
+	char ip6buf[INET6_ADDRSTRLEN];
+
+	/* make sure to invalidate the prefix until it is really freed. */
+	pr->ndpr_vltime = 0;
+	pr->ndpr_pltime = 0;
+
+	/*
+	 * Though these flags are now meaningless, we'd rather keep the value
+	 * of pr->ndpr_raf_onlink and pr->ndpr_raf_auto not to confuse users
+	 * when executing "ndp -p".
+	 */
+
+	if ((pr->ndpr_stateflags & NDPRF_ONLINK) != 0 &&
+	    (e = nd6_prefix_offlink(pr)) != 0) {
+		nd6log((LOG_ERR, "prelist_remove: failed to make %s/%d offlink "
+		    "on %s, errno=%d\n",
+		    ip6_sprintf(ip6buf, &pr->ndpr_prefix.sin6_addr),
+		    pr->ndpr_plen, if_name(pr->ndpr_ifp), e));
+		/* what should we do? */
+	}
+
+	if (pr->ndpr_refcnt > 0)
+		return;		/* notice here? */
+
+	s = splnet();
+
+	/* unlink ndpr_entry from nd_prefix list */
+	LIST_REMOVE(pr, ndpr_entry);
+
+	/* free list of routers that adversed the prefix */
+	for (pfr = pr->ndpr_advrtrs.lh_first; pfr; pfr = next) {
+		next = pfr->pfr_next;
+
+		free(pfr, M_IP6NDP);
+	}
+	splx(s);
+
+	free(pr, M_IP6NDP);
+
+	pfxlist_onlink_check();
+}
+
+/*
+ * dr - may be NULL
+ */
+
+static int
+prelist_update(struct nd_prefixctl *new, struct nd_defrouter *dr,
+    struct mbuf *m, int mcast)
+{
+	struct in6_ifaddr *ia6 = NULL, *ia6_match = NULL;
+	struct ifaddr *ifa;
+	struct ifnet *ifp = new->ndpr_ifp;
+	struct nd_prefix *pr;
+	int s = splnet();
+	int error = 0;
+	int newprefix = 0;
+	int auth;
+	struct in6_addrlifetime lt6_tmp;
+	char ip6buf[INET6_ADDRSTRLEN];
+
+	auth = 0;
+	if (m) {
+		/*
+		 * Authenticity for NA consists authentication for
+		 * both IP header and IP datagrams, doesn't it ?
+		 */
+#if defined(M_AUTHIPHDR) && defined(M_AUTHIPDGM)
+		auth = ((m->m_flags & M_AUTHIPHDR) &&
+		    (m->m_flags & M_AUTHIPDGM));
+#endif
+	}
+
+	if ((pr = nd6_prefix_lookup(new)) != NULL) {
+		/*
+		 * nd6_prefix_lookup() ensures that pr and new have the same
+		 * prefix on a same interface.
+		 */
+
+		/*
+		 * Update prefix information.  Note that the on-link (L) bit
+		 * and the autonomous (A) bit should NOT be changed from 1
+		 * to 0.
+		 */
+		if (new->ndpr_raf_onlink == 1)
+			pr->ndpr_raf_onlink = 1;
+		if (new->ndpr_raf_auto == 1)
+			pr->ndpr_raf_auto = 1;
+		if (new->ndpr_raf_onlink) {
+			pr->ndpr_vltime = new->ndpr_vltime;
+			pr->ndpr_pltime = new->ndpr_pltime;
+			(void)in6_init_prefix_ltimes(pr); /* XXX error case? */
+			pr->ndpr_lastupdate = time_second;
+		}
+
+		if (new->ndpr_raf_onlink &&
+		    (pr->ndpr_stateflags & NDPRF_ONLINK) == 0) {
+			int e;
+
+			if ((e = nd6_prefix_onlink(pr)) != 0) {
+				nd6log((LOG_ERR,
+				    "prelist_update: failed to make "
+				    "the prefix %s/%d on-link on %s "
+				    "(errno=%d)\n",
+				    ip6_sprintf(ip6buf,
+					    &pr->ndpr_prefix.sin6_addr),
+				    pr->ndpr_plen, if_name(pr->ndpr_ifp), e));
+				/* proceed anyway. XXX: is it correct? */
+			}
+		}
+
+		if (dr && pfxrtr_lookup(pr, dr) == NULL)
+			pfxrtr_add(pr, dr);
+	} else {
+		struct nd_prefix *newpr = NULL;
+
+		newprefix = 1;
+
+		if (new->ndpr_vltime == 0)
+			goto end;
+		if (new->ndpr_raf_onlink == 0 && new->ndpr_raf_auto == 0)
+			goto end;
+
+		error = nd6_prelist_add(new, dr, &newpr);
+		if (error != 0 || newpr == NULL) {
+			nd6log((LOG_NOTICE, "prelist_update: "
+			    "nd6_prelist_add failed for %s/%d on %s "
+			    "errno=%d, returnpr=%p\n",
+			    ip6_sprintf(ip6buf, &new->ndpr_prefix.sin6_addr),
+			    new->ndpr_plen, if_name(new->ndpr_ifp),
+			    error, newpr));
+			goto end; /* we should just give up in this case. */
+		}
+
+		/*
+		 * XXX: from the ND point of view, we can ignore a prefix
+		 * with the on-link bit being zero.  However, we need a
+		 * prefix structure for references from autoconfigured
+		 * addresses.  Thus, we explicitly make sure that the prefix
+		 * itself expires now.
+		 */
+		if (newpr->ndpr_raf_onlink == 0) {
+			newpr->ndpr_vltime = 0;
+			newpr->ndpr_pltime = 0;
+			in6_init_prefix_ltimes(newpr);
+		}
+
+		pr = newpr;
+	}
+
+	/*
+	 * Address autoconfiguration based on Section 5.5.3 of RFC 2462.
+	 * Note that pr must be non NULL at this point.
+	 */
+
+	/* 5.5.3 (a). Ignore the prefix without the A bit set. */
+	if (!new->ndpr_raf_auto)
+		goto end;
+
+	/*
+	 * 5.5.3 (b). the link-local prefix should have been ignored in
+	 * nd6_ra_input.
+	 */
+
+	/* 5.5.3 (c). Consistency check on lifetimes: pltime <= vltime. */
+	if (new->ndpr_pltime > new->ndpr_vltime) {
+		error = EINVAL;	/* XXX: won't be used */
+		goto end;
+	}
+
+	/*
+	 * 5.5.3 (d).  If the prefix advertised is not equal to the prefix of
+	 * an address configured by stateless autoconfiguration already in the
+	 * list of addresses associated with the interface, and the Valid
+	 * Lifetime is not 0, form an address.  We first check if we have
+	 * a matching prefix.
+	 * Note: we apply a clarification in rfc2462bis-02 here.  We only
+	 * consider autoconfigured addresses while RFC2462 simply said
+	 * "address".
+	 */
+	IF_ADDR_LOCK(ifp);
+	TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
+		struct in6_ifaddr *ifa6;
+		u_int32_t remaininglifetime;
+
+		if (ifa->ifa_addr->sa_family != AF_INET6)
+			continue;
+
+		ifa6 = (struct in6_ifaddr *)ifa;
+
+		/*
+		 * We only consider autoconfigured addresses as per rfc2462bis.
+		 */
+		if (!(ifa6->ia6_flags & IN6_IFF_AUTOCONF))
+			continue;
+
+		/*
+		 * Spec is not clear here, but I believe we should concentrate
+		 * on unicast (i.e. not anycast) addresses.
+		 * XXX: other ia6_flags? detached or duplicated?
+		 */
+		if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0)
+			continue;
+
+		/*
+		 * Ignore the address if it is not associated with a prefix
+		 * or is associated with a prefix that is different from this
+		 * one.  (pr is never NULL here)
+		 */
+		if (ifa6->ia6_ndpr != pr)
+			continue;
+
+		if (ia6_match == NULL) /* remember the first one */
+			ia6_match = ifa6;
+
+		/*
+		 * An already autoconfigured address matched.  Now that we
+		 * are sure there is at least one matched address, we can
+		 * proceed to 5.5.3. (e): update the lifetimes according to the
+		 * "two hours" rule and the privacy extension.
+		 * We apply some clarifications in rfc2462bis:
+		 * - use remaininglifetime instead of storedlifetime as a
+		 *   variable name
+		 * - remove the dead code in the "two-hour" rule
+		 */
+#define TWOHOUR		(120*60)
+		lt6_tmp = ifa6->ia6_lifetime;
+
+		if (lt6_tmp.ia6t_vltime == ND6_INFINITE_LIFETIME)
+			remaininglifetime = ND6_INFINITE_LIFETIME;
+		else if (time_second - ifa6->ia6_updatetime >
+			 lt6_tmp.ia6t_vltime) {
+			/*
+			 * The case of "invalid" address.  We should usually
+			 * not see this case.
+			 */
+			remaininglifetime = 0;
+		} else
+			remaininglifetime = lt6_tmp.ia6t_vltime -
+			    (time_second - ifa6->ia6_updatetime);
+
+		/* when not updating, keep the current stored lifetime. */
+		lt6_tmp.ia6t_vltime = remaininglifetime;
+
+		if (TWOHOUR < new->ndpr_vltime ||
+		    remaininglifetime < new->ndpr_vltime) {
+			lt6_tmp.ia6t_vltime = new->ndpr_vltime;
+		} else if (remaininglifetime <= TWOHOUR) {
+			if (auth) {
+				lt6_tmp.ia6t_vltime = new->ndpr_vltime;
+			}
+		} else {
+			/*
+			 * new->ndpr_vltime <= TWOHOUR &&
+			 * TWOHOUR < remaininglifetime
+			 */
+			lt6_tmp.ia6t_vltime = TWOHOUR;
+		}
+
+		/* The 2 hour rule is not imposed for preferred lifetime. */
+		lt6_tmp.ia6t_pltime = new->ndpr_pltime;
+
+		in6_init_address_ltimes(pr, &lt6_tmp);
+
+		/*
+		 * We need to treat lifetimes for temporary addresses
+		 * differently, according to
+		 * draft-ietf-ipv6-privacy-addrs-v2-01.txt 3.3 (1);
+		 * we only update the lifetimes when they are in the maximum
+		 * intervals.
+		 */
+		if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0) {
+			u_int32_t maxvltime, maxpltime;
+
+			if (V_ip6_temp_valid_lifetime >
+			    (u_int32_t)((time_second - ifa6->ia6_createtime) +
+			    V_ip6_desync_factor)) {
+				maxvltime = V_ip6_temp_valid_lifetime -
+				    (time_second - ifa6->ia6_createtime) -
+				    V_ip6_desync_factor;
+			} else
+				maxvltime = 0;
+			if (V_ip6_temp_preferred_lifetime >
+			    (u_int32_t)((time_second - ifa6->ia6_createtime) +
+			    V_ip6_desync_factor)) {
+				maxpltime = V_ip6_temp_preferred_lifetime -
+				    (time_second - ifa6->ia6_createtime) -
+				    V_ip6_desync_factor;
+			} else
+				maxpltime = 0;
+
+			if (lt6_tmp.ia6t_vltime == ND6_INFINITE_LIFETIME ||
+			    lt6_tmp.ia6t_vltime > maxvltime) {
+				lt6_tmp.ia6t_vltime = maxvltime;
+			}
+			if (lt6_tmp.ia6t_pltime == ND6_INFINITE_LIFETIME ||
+			    lt6_tmp.ia6t_pltime > maxpltime) {
+				lt6_tmp.ia6t_pltime = maxpltime;
+			}
+		}
+		ifa6->ia6_lifetime = lt6_tmp;
+		ifa6->ia6_updatetime = time_second;
+	}
+	IF_ADDR_UNLOCK(ifp);
+	if (ia6_match == NULL && new->ndpr_vltime) {
+		int ifidlen;
+
+		/*
+		 * 5.5.3 (d) (continued)
+		 * No address matched and the valid lifetime is non-zero.
+		 * Create a new address.
+		 */
+
+		/*
+		 * Prefix Length check:
+		 * If the sum of the prefix length and interface identifier
+		 * length does not equal 128 bits, the Prefix Information
+		 * option MUST be ignored.  The length of the interface
+		 * identifier is defined in a separate link-type specific
+		 * document.
+		 */
+		ifidlen = in6_if2idlen(ifp);
+		if (ifidlen < 0) {
+			/* this should not happen, so we always log it. */
+			log(LOG_ERR, "prelist_update: IFID undefined (%s)\n",
+			    if_name(ifp));
+			goto end;
+		}
+		if (ifidlen + pr->ndpr_plen != 128) {
+			nd6log((LOG_INFO,
+			    "prelist_update: invalid prefixlen "
+			    "%d for %s, ignored\n",
+			    pr->ndpr_plen, if_name(ifp)));
+			goto end;
+		}
+
+		if ((ia6 = in6_ifadd(new, mcast)) != NULL) {
+			/*
+			 * note that we should use pr (not new) for reference.
+			 */
+			pr->ndpr_refcnt++;
+			ia6->ia6_ndpr = pr;
+
+			/*
+			 * RFC 3041 3.3 (2).
+			 * When a new public address is created as described
+			 * in RFC2462, also create a new temporary address.
+			 *
+			 * RFC 3041 3.5.
+			 * When an interface connects to a new link, a new
+			 * randomized interface identifier should be generated
+			 * immediately together with a new set of temporary
+			 * addresses.  Thus, we specifiy 1 as the 2nd arg of
+			 * in6_tmpifadd().
+			 */
+			if (V_ip6_use_tempaddr) {
+				int e;
+				if ((e = in6_tmpifadd(ia6, 1, 1)) != 0) {
+					nd6log((LOG_NOTICE, "prelist_update: "
+					    "failed to create a temporary "
+					    "address, errno=%d\n",
+					    e));
+				}
+			}
+			ifa_free(&ia6->ia_ifa);
+
+			/*
+			 * A newly added address might affect the status
+			 * of other addresses, so we check and update it.
+			 * XXX: what if address duplication happens?
+			 */
+			pfxlist_onlink_check();
+		} else {
+			/* just set an error. do not bark here. */
+			error = EADDRNOTAVAIL; /* XXX: might be unused. */
+		}
+	}
+
+ end:
+	splx(s);
+	return error;
+}
+
+/*
+ * A supplement function used in the on-link detection below;
+ * detect if a given prefix has a (probably) reachable advertising router.
+ * XXX: lengthy function name...
+ */
+static struct nd_pfxrouter *
+find_pfxlist_reachable_router(struct nd_prefix *pr)
+{
+	struct nd_pfxrouter *pfxrtr;
+	struct llentry *ln;
+	int canreach;
+
+	for (pfxrtr = LIST_FIRST(&pr->ndpr_advrtrs); pfxrtr != NULL;
+	     pfxrtr = LIST_NEXT(pfxrtr, pfr_entry)) {
+		IF_AFDATA_LOCK(pfxrtr->router->ifp);
+		ln = nd6_lookup(&pfxrtr->router->rtaddr, 0, pfxrtr->router->ifp);
+		IF_AFDATA_UNLOCK(pfxrtr->router->ifp);
+		if (ln == NULL)
+			continue;
+		canreach = ND6_IS_LLINFO_PROBREACH(ln);
+		LLE_RUNLOCK(ln);
+		if (canreach)
+			break;
+	}
+	return (pfxrtr);
+}
+
+/*
+ * Check if each prefix in the prefix list has at least one available router
+ * that advertised the prefix (a router is "available" if its neighbor cache
+ * entry is reachable or probably reachable).
+ * If the check fails, the prefix may be off-link, because, for example,
+ * we have moved from the network but the lifetime of the prefix has not
+ * expired yet.  So we should not use the prefix if there is another prefix
+ * that has an available router.
+ * But, if there is no prefix that has an available router, we still regards
+ * all the prefixes as on-link.  This is because we can't tell if all the
+ * routers are simply dead or if we really moved from the network and there
+ * is no router around us.
+ */
+void
+pfxlist_onlink_check()
+{
+	struct nd_prefix *pr;
+	struct in6_ifaddr *ifa;
+	struct nd_defrouter *dr;
+	struct nd_pfxrouter *pfxrtr = NULL;
+
+	/*
+	 * Check if there is a prefix that has a reachable advertising
+	 * router.
+	 */
+	for (pr = V_nd_prefix.lh_first; pr; pr = pr->ndpr_next) {
+		if (pr->ndpr_raf_onlink && find_pfxlist_reachable_router(pr))
+			break;
+	}
+
+	/*
+	 * If we have no such prefix, check whether we still have a router
+	 * that does not advertise any prefixes.
+	 */
+	if (pr == NULL) {
+		for (dr = TAILQ_FIRST(&V_nd_defrouter); dr;
+		    dr = TAILQ_NEXT(dr, dr_entry)) {
+			struct nd_prefix *pr0;
+
+			for (pr0 = V_nd_prefix.lh_first; pr0;
+			    pr0 = pr0->ndpr_next) {
+				if ((pfxrtr = pfxrtr_lookup(pr0, dr)) != NULL)
+					break;
+			}
+			if (pfxrtr != NULL)
+				break;
+		}
+	}
+	if (pr != NULL || (TAILQ_FIRST(&V_nd_defrouter) && pfxrtr == NULL)) {
+		/*
+		 * There is at least one prefix that has a reachable router,
+		 * or at least a router which probably does not advertise
+		 * any prefixes.  The latter would be the case when we move
+		 * to a new link where we have a router that does not provide
+		 * prefixes and we configure an address by hand.
+		 * Detach prefixes which have no reachable advertising
+		 * router, and attach other prefixes.
+		 */
+		for (pr = V_nd_prefix.lh_first; pr; pr = pr->ndpr_next) {
+			/* XXX: a link-local prefix should never be detached */
+			if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr))
+				continue;
+
+			/*
+			 * we aren't interested in prefixes without the L bit
+			 * set.
+			 */
+			if (pr->ndpr_raf_onlink == 0)
+				continue;
+
+			if (pr->ndpr_raf_auto == 0)
+				continue;
+
+			if ((pr->ndpr_stateflags & NDPRF_DETACHED) == 0 &&
+			    find_pfxlist_reachable_router(pr) == NULL)
+				pr->ndpr_stateflags |= NDPRF_DETACHED;
+			if ((pr->ndpr_stateflags & NDPRF_DETACHED) != 0 &&
+			    find_pfxlist_reachable_router(pr) != 0)
+				pr->ndpr_stateflags &= ~NDPRF_DETACHED;
+		}
+	} else {
+		/* there is no prefix that has a reachable router */
+		for (pr = V_nd_prefix.lh_first; pr; pr = pr->ndpr_next) {
+			if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr))
+				continue;
+
+			if (pr->ndpr_raf_onlink == 0)
+				continue;
+
+			if (pr->ndpr_raf_auto == 0)
+				continue;
+
+			if ((pr->ndpr_stateflags & NDPRF_DETACHED) != 0)
+				pr->ndpr_stateflags &= ~NDPRF_DETACHED;
+		}
+	}
+
+	/*
+	 * Remove each interface route associated with a (just) detached
+	 * prefix, and reinstall the interface route for a (just) attached
+	 * prefix.  Note that all attempt of reinstallation does not
+	 * necessarily success, when a same prefix is shared among multiple
+	 * interfaces.  Such cases will be handled in nd6_prefix_onlink,
+	 * so we don't have to care about them.
+	 */
+	for (pr = V_nd_prefix.lh_first; pr; pr = pr->ndpr_next) {
+		int e;
+		char ip6buf[INET6_ADDRSTRLEN];
+
+		if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr))
+			continue;
+
+		if (pr->ndpr_raf_onlink == 0)
+			continue;
+
+		if (pr->ndpr_raf_auto == 0)
+			continue;
+
+		if ((pr->ndpr_stateflags & NDPRF_DETACHED) != 0 &&
+		    (pr->ndpr_stateflags & NDPRF_ONLINK) != 0) {
+			if ((e = nd6_prefix_offlink(pr)) != 0) {
+				nd6log((LOG_ERR,
+				    "pfxlist_onlink_check: failed to "
+				    "make %s/%d offlink, errno=%d\n",
+				    ip6_sprintf(ip6buf,
+					    &pr->ndpr_prefix.sin6_addr),
+					    pr->ndpr_plen, e));
+			}
+		}
+		if ((pr->ndpr_stateflags & NDPRF_DETACHED) == 0 &&
+		    (pr->ndpr_stateflags & NDPRF_ONLINK) == 0 &&
+		    pr->ndpr_raf_onlink) {
+			if ((e = nd6_prefix_onlink(pr)) != 0) {
+				nd6log((LOG_ERR,
+				    "pfxlist_onlink_check: failed to "
+				    "make %s/%d onlink, errno=%d\n",
+				    ip6_sprintf(ip6buf,
+					    &pr->ndpr_prefix.sin6_addr),
+					    pr->ndpr_plen, e));
+			}
+		}
+	}
+
+	/*
+	 * Changes on the prefix status might affect address status as well.
+	 * Make sure that all addresses derived from an attached prefix are
+	 * attached, and that all addresses derived from a detached prefix are
+	 * detached.  Note, however, that a manually configured address should
+	 * always be attached.
+	 * The precise detection logic is same as the one for prefixes.
+	 *
+	 * XXXRW: in6_ifaddrhead locking.
+	 */
+	TAILQ_FOREACH(ifa, &V_in6_ifaddrhead, ia_link) {
+		if (!(ifa->ia6_flags & IN6_IFF_AUTOCONF))
+			continue;
+
+		if (ifa->ia6_ndpr == NULL) {
+			/*
+			 * This can happen when we first configure the address
+			 * (i.e. the address exists, but the prefix does not).
+			 * XXX: complicated relationships...
+			 */
+			continue;
+		}
+
+		if (find_pfxlist_reachable_router(ifa->ia6_ndpr))
+			break;
+	}
+	if (ifa) {
+		TAILQ_FOREACH(ifa, &V_in6_ifaddrhead, ia_link) {
+			if ((ifa->ia6_flags & IN6_IFF_AUTOCONF) == 0)
+				continue;
+
+			if (ifa->ia6_ndpr == NULL) /* XXX: see above. */
+				continue;
+
+			if (find_pfxlist_reachable_router(ifa->ia6_ndpr)) {
+				if (ifa->ia6_flags & IN6_IFF_DETACHED) {
+					ifa->ia6_flags &= ~IN6_IFF_DETACHED;
+					ifa->ia6_flags |= IN6_IFF_TENTATIVE;
+					nd6_dad_start((struct ifaddr *)ifa, 0);
+				}
+			} else {
+				ifa->ia6_flags |= IN6_IFF_DETACHED;
+			}
+		}
+	}
+	else {
+		TAILQ_FOREACH(ifa, &V_in6_ifaddrhead, ia_link) {
+			if ((ifa->ia6_flags & IN6_IFF_AUTOCONF) == 0)
+				continue;
+
+			if (ifa->ia6_flags & IN6_IFF_DETACHED) {
+				ifa->ia6_flags &= ~IN6_IFF_DETACHED;
+				ifa->ia6_flags |= IN6_IFF_TENTATIVE;
+				/* Do we need a delay in this case? */
+				nd6_dad_start((struct ifaddr *)ifa, 0);
+			}
+		}
+	}
+}
+
+int
+nd6_prefix_onlink(struct nd_prefix *pr)
+{
+	struct ifaddr *ifa;
+	struct ifnet *ifp = pr->ndpr_ifp;
+	struct sockaddr_in6 mask6;
+	struct nd_prefix *opr;
+	u_long rtflags;
+	int error = 0;
+	struct radix_node_head *rnh;
+	struct rtentry *rt = NULL;
+	char ip6buf[INET6_ADDRSTRLEN];
+	struct sockaddr_dl null_sdl = {sizeof(null_sdl), AF_LINK};
+
+	/* sanity check */
+	if ((pr->ndpr_stateflags & NDPRF_ONLINK) != 0) {
+		nd6log((LOG_ERR,
+		    "nd6_prefix_onlink: %s/%d is already on-link\n",
+		    ip6_sprintf(ip6buf, &pr->ndpr_prefix.sin6_addr),
+		    pr->ndpr_plen));
+		return (EEXIST);
+	}
+
+	/*
+	 * Add the interface route associated with the prefix.  Before
+	 * installing the route, check if there's the same prefix on another
+	 * interface, and the prefix has already installed the interface route.
+	 * Although such a configuration is expected to be rare, we explicitly
+	 * allow it.
+	 */
+	for (opr = V_nd_prefix.lh_first; opr; opr = opr->ndpr_next) {
+		if (opr == pr)
+			continue;
+
+		if ((opr->ndpr_stateflags & NDPRF_ONLINK) == 0)
+			continue;
+
+		if (opr->ndpr_plen == pr->ndpr_plen &&
+		    in6_are_prefix_equal(&pr->ndpr_prefix.sin6_addr,
+		    &opr->ndpr_prefix.sin6_addr, pr->ndpr_plen))
+			return (0);
+	}
+
+	/*
+	 * We prefer link-local addresses as the associated interface address.
+	 */
+	/* search for a link-local addr */
+	ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp,
+	    IN6_IFF_NOTREADY | IN6_IFF_ANYCAST);
+	if (ifa == NULL) {
+		/* XXX: freebsd does not have ifa_ifwithaf */
+		IF_ADDR_LOCK(ifp);
+		TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
+			if (ifa->ifa_addr->sa_family == AF_INET6)
+				break;
+		}
+		if (ifa != NULL)
+			ifa_ref(ifa);
+		IF_ADDR_UNLOCK(ifp);
+		/* should we care about ia6_flags? */
+	}
+	if (ifa == NULL) {
+		/*
+		 * This can still happen, when, for example, we receive an RA
+		 * containing a prefix with the L bit set and the A bit clear,
+		 * after removing all IPv6 addresses on the receiving
+		 * interface.  This should, of course, be rare though.
+		 */
+		nd6log((LOG_NOTICE,
+		    "nd6_prefix_onlink: failed to find any ifaddr"
+		    " to add route for a prefix(%s/%d) on %s\n",
+		    ip6_sprintf(ip6buf, &pr->ndpr_prefix.sin6_addr),
+		    pr->ndpr_plen, if_name(ifp)));
+		return (0);
+	}
+
+	/*
+	 * in6_ifinit() sets nd6_rtrequest to ifa_rtrequest for all ifaddrs.
+	 * ifa->ifa_rtrequest = nd6_rtrequest;
+	 */
+	bzero(&mask6, sizeof(mask6));
+	mask6.sin6_len = sizeof(mask6);
+	mask6.sin6_addr = pr->ndpr_mask;
+	rtflags = (ifa->ifa_flags & ~IFA_RTSELF) | RTF_UP;
+	error = rtrequest(RTM_ADD, (struct sockaddr *)&pr->ndpr_prefix,
+	    ifa->ifa_addr, (struct sockaddr *)&mask6, rtflags, &rt);
+	if (error == 0) {
+		if (rt != NULL) /* this should be non NULL, though */ {
+			rnh = rt_tables_get_rnh(rt->rt_fibnum, AF_INET6);
+			/* XXX what if rhn == NULL? */
+			RADIX_NODE_HEAD_LOCK(rnh);
+			RT_LOCK(rt);
+			if (!rt_setgate(rt, rt_key(rt), (struct sockaddr *)&null_sdl)) {
+				((struct sockaddr_dl *)rt->rt_gateway)->sdl_type =
+					rt->rt_ifp->if_type;
+				((struct sockaddr_dl *)rt->rt_gateway)->sdl_index =
+					rt->rt_ifp->if_index;
+			}
+			RADIX_NODE_HEAD_UNLOCK(rnh);
+			nd6_rtmsg(RTM_ADD, rt);
+			RT_UNLOCK(rt);
+		}
+		pr->ndpr_stateflags |= NDPRF_ONLINK;
+	} else {
+		char ip6bufg[INET6_ADDRSTRLEN], ip6bufm[INET6_ADDRSTRLEN];
+		nd6log((LOG_ERR, "nd6_prefix_onlink: failed to add route for a"
+		    " prefix (%s/%d) on %s, gw=%s, mask=%s, flags=%lx "
+		    "errno = %d\n",
+		    ip6_sprintf(ip6buf, &pr->ndpr_prefix.sin6_addr),
+		    pr->ndpr_plen, if_name(ifp),
+		    ip6_sprintf(ip6bufg, &((struct sockaddr_in6 *)ifa->ifa_addr)->sin6_addr),
+		    ip6_sprintf(ip6bufm, &mask6.sin6_addr), rtflags, error));
+	}
+
+	if (rt != NULL) {
+		RT_LOCK(rt);
+		RT_REMREF(rt);
+		RT_UNLOCK(rt);
+	}
+	if (ifa != NULL)
+		ifa_free(ifa);
+
+	return (error);
+}
+
+int
+nd6_prefix_offlink(struct nd_prefix *pr)
+{
+	int error = 0;
+	struct ifnet *ifp = pr->ndpr_ifp;
+	struct nd_prefix *opr;
+	struct sockaddr_in6 sa6, mask6;
+	struct rtentry *rt = NULL;
+	char ip6buf[INET6_ADDRSTRLEN];
+
+	/* sanity check */
+	if ((pr->ndpr_stateflags & NDPRF_ONLINK) == 0) {
+		nd6log((LOG_ERR,
+		    "nd6_prefix_offlink: %s/%d is already off-link\n",
+		    ip6_sprintf(ip6buf, &pr->ndpr_prefix.sin6_addr),
+		    pr->ndpr_plen));
+		return (EEXIST);
+	}
+
+	bzero(&sa6, sizeof(sa6));
+	sa6.sin6_family = AF_INET6;
+	sa6.sin6_len = sizeof(sa6);
+	bcopy(&pr->ndpr_prefix.sin6_addr, &sa6.sin6_addr,
+	    sizeof(struct in6_addr));
+	bzero(&mask6, sizeof(mask6));
+	mask6.sin6_family = AF_INET6;
+	mask6.sin6_len = sizeof(sa6);
+	bcopy(&pr->ndpr_mask, &mask6.sin6_addr, sizeof(struct in6_addr));
+	error = rtrequest(RTM_DELETE, (struct sockaddr *)&sa6, NULL,
+	    (struct sockaddr *)&mask6, 0, &rt);
+	if (error == 0) {
+		pr->ndpr_stateflags &= ~NDPRF_ONLINK;
+
+		/* report the route deletion to the routing socket. */
+		if (rt != NULL)
+			nd6_rtmsg(RTM_DELETE, rt);
+
+		/*
+		 * There might be the same prefix on another interface,
+		 * the prefix which could not be on-link just because we have
+		 * the interface route (see comments in nd6_prefix_onlink).
+		 * If there's one, try to make the prefix on-link on the
+		 * interface.
+		 */
+		for (opr = V_nd_prefix.lh_first; opr; opr = opr->ndpr_next) {
+			if (opr == pr)
+				continue;
+
+			if ((opr->ndpr_stateflags & NDPRF_ONLINK) != 0)
+				continue;
+
+			/*
+			 * KAME specific: detached prefixes should not be
+			 * on-link.
+			 */
+			if ((opr->ndpr_stateflags & NDPRF_DETACHED) != 0)
+				continue;
+
+			if (opr->ndpr_plen == pr->ndpr_plen &&
+			    in6_are_prefix_equal(&pr->ndpr_prefix.sin6_addr,
+			    &opr->ndpr_prefix.sin6_addr, pr->ndpr_plen)) {
+				int e;
+
+				if ((e = nd6_prefix_onlink(opr)) != 0) {
+					nd6log((LOG_ERR,
+					    "nd6_prefix_offlink: failed to "
+					    "recover a prefix %s/%d from %s "
+					    "to %s (errno = %d)\n",
+					    ip6_sprintf(ip6buf,
+						&opr->ndpr_prefix.sin6_addr),
+					    opr->ndpr_plen, if_name(ifp),
+					    if_name(opr->ndpr_ifp), e));
+				}
+			}
+		}
+	} else {
+		/* XXX: can we still set the NDPRF_ONLINK flag? */
+		nd6log((LOG_ERR,
+		    "nd6_prefix_offlink: failed to delete route: "
+		    "%s/%d on %s (errno = %d)\n",
+		    ip6_sprintf(ip6buf, &sa6.sin6_addr), pr->ndpr_plen,
+		    if_name(ifp), error));
+	}
+
+	if (rt != NULL) {
+		RTFREE(rt);
+	}
+
+	return (error);
+}
+
+static struct in6_ifaddr *
+in6_ifadd(struct nd_prefixctl *pr, int mcast)
+{
+	struct ifnet *ifp = pr->ndpr_ifp;
+	struct ifaddr *ifa;
+	struct in6_aliasreq ifra;
+	struct in6_ifaddr *ia, *ib;
+	int error, plen0;
+	struct in6_addr mask;
+	int prefixlen = pr->ndpr_plen;
+	int updateflags;
+	char ip6buf[INET6_ADDRSTRLEN];
+
+	in6_prefixlen2mask(&mask, prefixlen);
+
+	/*
+	 * find a link-local address (will be interface ID).
+	 * Is it really mandatory? Theoretically, a global or a site-local
+	 * address can be configured without a link-local address, if we
+	 * have a unique interface identifier...
+	 *
+	 * it is not mandatory to have a link-local address, we can generate
+	 * interface identifier on the fly.  we do this because:
+	 * (1) it should be the easiest way to find interface identifier.
+	 * (2) RFC2462 5.4 suggesting the use of the same interface identifier
+	 * for multiple addresses on a single interface, and possible shortcut
+	 * of DAD.  we omitted DAD for this reason in the past.
+	 * (3) a user can prevent autoconfiguration of global address
+	 * by removing link-local address by hand (this is partly because we
+	 * don't have other way to control the use of IPv6 on an interface.
+	 * this has been our design choice - cf. NRL's "ifconfig auto").
+	 * (4) it is easier to manage when an interface has addresses
+	 * with the same interface identifier, than to have multiple addresses
+	 * with different interface identifiers.
+	 */
+	ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp, 0); /* 0 is OK? */
+	if (ifa)
+		ib = (struct in6_ifaddr *)ifa;
+	else
+		return NULL;
+
+	/* prefixlen + ifidlen must be equal to 128 */
+	plen0 = in6_mask2len(&ib->ia_prefixmask.sin6_addr, NULL);
+	if (prefixlen != plen0) {
+		ifa_free(ifa);
+		nd6log((LOG_INFO, "in6_ifadd: wrong prefixlen for %s "
+		    "(prefix=%d ifid=%d)\n",
+		    if_name(ifp), prefixlen, 128 - plen0));
+		return NULL;
+	}
+
+	/* make ifaddr */
+
+	bzero(&ifra, sizeof(ifra));
+	/*
+	 * in6_update_ifa() does not use ifra_name, but we accurately set it
+	 * for safety.
+	 */
+	strncpy(ifra.ifra_name, if_name(ifp), sizeof(ifra.ifra_name));
+	ifra.ifra_addr.sin6_family = AF_INET6;
+	ifra.ifra_addr.sin6_len = sizeof(struct sockaddr_in6);
+	/* prefix */
+	ifra.ifra_addr.sin6_addr = pr->ndpr_prefix.sin6_addr;
+	ifra.ifra_addr.sin6_addr.s6_addr32[0] &= mask.s6_addr32[0];
+	ifra.ifra_addr.sin6_addr.s6_addr32[1] &= mask.s6_addr32[1];
+	ifra.ifra_addr.sin6_addr.s6_addr32[2] &= mask.s6_addr32[2];
+	ifra.ifra_addr.sin6_addr.s6_addr32[3] &= mask.s6_addr32[3];
+
+	/* interface ID */
+	ifra.ifra_addr.sin6_addr.s6_addr32[0] |=
+	    (ib->ia_addr.sin6_addr.s6_addr32[0] & ~mask.s6_addr32[0]);
+	ifra.ifra_addr.sin6_addr.s6_addr32[1] |=
+	    (ib->ia_addr.sin6_addr.s6_addr32[1] & ~mask.s6_addr32[1]);
+	ifra.ifra_addr.sin6_addr.s6_addr32[2] |=
+	    (ib->ia_addr.sin6_addr.s6_addr32[2] & ~mask.s6_addr32[2]);
+	ifra.ifra_addr.sin6_addr.s6_addr32[3] |=
+	    (ib->ia_addr.sin6_addr.s6_addr32[3] & ~mask.s6_addr32[3]);
+	ifa_free(ifa);
+
+	/* new prefix mask. */
+	ifra.ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6);
+	ifra.ifra_prefixmask.sin6_family = AF_INET6;
+	bcopy(&mask, &ifra.ifra_prefixmask.sin6_addr,
+	    sizeof(ifra.ifra_prefixmask.sin6_addr));
+
+	/* lifetimes. */
+	ifra.ifra_lifetime.ia6t_vltime = pr->ndpr_vltime;
+	ifra.ifra_lifetime.ia6t_pltime = pr->ndpr_pltime;
+
+	/* XXX: scope zone ID? */
+
+	ifra.ifra_flags |= IN6_IFF_AUTOCONF; /* obey autoconf */
+
+	/*
+	 * Make sure that we do not have this address already.  This should
+	 * usually not happen, but we can still see this case, e.g., if we
+	 * have manually configured the exact address to be configured.
+	 */
+	ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp,
+	    &ifra.ifra_addr.sin6_addr);
+	if (ifa != NULL) {
+		ifa_free(ifa);
+		/* this should be rare enough to make an explicit log */
+		log(LOG_INFO, "in6_ifadd: %s is already configured\n",
+		    ip6_sprintf(ip6buf, &ifra.ifra_addr.sin6_addr));
+		return (NULL);
+	}
+
+	/*
+	 * Allocate ifaddr structure, link into chain, etc.
+	 * If we are going to create a new address upon receiving a multicasted
+	 * RA, we need to impose a random delay before starting DAD.
+	 * [draft-ietf-ipv6-rfc2462bis-02.txt, Section 5.4.2]
+	 */
+	updateflags = 0;
+	if (mcast)
+		updateflags |= IN6_IFAUPDATE_DADDELAY;
+	if ((error = in6_update_ifa(ifp, &ifra, NULL, updateflags)) != 0) {
+		nd6log((LOG_ERR,
+		    "in6_ifadd: failed to make ifaddr %s on %s (errno=%d)\n",
+		    ip6_sprintf(ip6buf, &ifra.ifra_addr.sin6_addr),
+		    if_name(ifp), error));
+		return (NULL);	/* ifaddr must not have been allocated. */
+	}
+
+	ia = in6ifa_ifpwithaddr(ifp, &ifra.ifra_addr.sin6_addr);
+	/*
+	 * XXXRW: Assumption of non-NULLness here might not be true with
+	 * fine-grained locking -- should we validate it?  Or just return
+	 * earlier ifa rather than looking it up again?
+	 */
+	return (ia);		/* this is always non-NULL  and referenced. */
+}
+
+/*
+ * ia0 - corresponding public address
+ */
+int
+in6_tmpifadd(const struct in6_ifaddr *ia0, int forcegen, int delay)
+{
+	struct ifnet *ifp = ia0->ia_ifa.ifa_ifp;
+	struct in6_ifaddr *newia, *ia;
+	struct in6_aliasreq ifra;
+	int i, error;
+	int trylimit = 3;	/* XXX: adhoc value */
+	int updateflags;
+	u_int32_t randid[2];
+	time_t vltime0, pltime0;
+
+	bzero(&ifra, sizeof(ifra));
+	strncpy(ifra.ifra_name, if_name(ifp), sizeof(ifra.ifra_name));
+	ifra.ifra_addr = ia0->ia_addr;
+	/* copy prefix mask */
+	ifra.ifra_prefixmask = ia0->ia_prefixmask;
+	/* clear the old IFID */
+	for (i = 0; i < 4; i++) {
+		ifra.ifra_addr.sin6_addr.s6_addr32[i] &=
+		    ifra.ifra_prefixmask.sin6_addr.s6_addr32[i];
+	}
+
+  again:
+	if (in6_get_tmpifid(ifp, (u_int8_t *)randid,
+	    (const u_int8_t *)&ia0->ia_addr.sin6_addr.s6_addr[8], forcegen)) {
+		nd6log((LOG_NOTICE, "in6_tmpifadd: failed to find a good "
+		    "random IFID\n"));
+		return (EINVAL);
+	}
+	ifra.ifra_addr.sin6_addr.s6_addr32[2] |=
+	    (randid[0] & ~(ifra.ifra_prefixmask.sin6_addr.s6_addr32[2]));
+	ifra.ifra_addr.sin6_addr.s6_addr32[3] |=
+	    (randid[1] & ~(ifra.ifra_prefixmask.sin6_addr.s6_addr32[3]));
+
+	/*
+	 * in6_get_tmpifid() quite likely provided a unique interface ID.
+	 * However, we may still have a chance to see collision, because
+	 * there may be a time lag between generation of the ID and generation
+	 * of the address.  So, we'll do one more sanity check.
+	 */
+	IN6_IFADDR_RLOCK();
+	TAILQ_FOREACH(ia, &V_in6_ifaddrhead, ia_link) {
+		if (IN6_ARE_ADDR_EQUAL(&ia->ia_addr.sin6_addr,
+		    &ifra.ifra_addr.sin6_addr)) {
+			if (trylimit-- == 0) {
+				IN6_IFADDR_RUNLOCK();
+				/*
+				 * Give up.  Something strange should have
+				 * happened.
+				 */
+				nd6log((LOG_NOTICE, "in6_tmpifadd: failed to "
+				    "find a unique random IFID\n"));
+				return (EEXIST);
+			}
+			IN6_IFADDR_RUNLOCK();
+			forcegen = 1;
+			goto again;
+		}
+	}
+	IN6_IFADDR_RUNLOCK();
+
+	/*
+	 * The Valid Lifetime is the lower of the Valid Lifetime of the
+         * public address or TEMP_VALID_LIFETIME.
+	 * The Preferred Lifetime is the lower of the Preferred Lifetime
+         * of the public address or TEMP_PREFERRED_LIFETIME -
+         * DESYNC_FACTOR.
+	 */
+	if (ia0->ia6_lifetime.ia6t_vltime != ND6_INFINITE_LIFETIME) {
+		vltime0 = IFA6_IS_INVALID(ia0) ? 0 :
+		    (ia0->ia6_lifetime.ia6t_vltime -
+		    (time_second - ia0->ia6_updatetime));
+		if (vltime0 > V_ip6_temp_valid_lifetime)
+			vltime0 = V_ip6_temp_valid_lifetime;
+	} else
+		vltime0 = V_ip6_temp_valid_lifetime;
+	if (ia0->ia6_lifetime.ia6t_pltime != ND6_INFINITE_LIFETIME) {
+		pltime0 = IFA6_IS_DEPRECATED(ia0) ? 0 :
+		    (ia0->ia6_lifetime.ia6t_pltime -
+		    (time_second - ia0->ia6_updatetime));
+		if (pltime0 > V_ip6_temp_preferred_lifetime - V_ip6_desync_factor){
+			pltime0 = V_ip6_temp_preferred_lifetime -
+			    V_ip6_desync_factor;
+		}
+	} else
+		pltime0 = V_ip6_temp_preferred_lifetime - V_ip6_desync_factor;
+	ifra.ifra_lifetime.ia6t_vltime = vltime0;
+	ifra.ifra_lifetime.ia6t_pltime = pltime0;
+
+	/*
+	 * A temporary address is created only if this calculated Preferred
+	 * Lifetime is greater than REGEN_ADVANCE time units.
+	 */
+	if (ifra.ifra_lifetime.ia6t_pltime <= V_ip6_temp_regen_advance)
+		return (0);
+
+	/* XXX: scope zone ID? */
+
+	ifra.ifra_flags |= (IN6_IFF_AUTOCONF|IN6_IFF_TEMPORARY);
+
+	/* allocate ifaddr structure, link into chain, etc. */
+	updateflags = 0;
+	if (delay)
+		updateflags |= IN6_IFAUPDATE_DADDELAY;
+	if ((error = in6_update_ifa(ifp, &ifra, NULL, updateflags)) != 0)
+		return (error);
+
+	newia = in6ifa_ifpwithaddr(ifp, &ifra.ifra_addr.sin6_addr);
+	if (newia == NULL) {	/* XXX: can it happen? */
+		nd6log((LOG_ERR,
+		    "in6_tmpifadd: ifa update succeeded, but we got "
+		    "no ifaddr\n"));
+		return (EINVAL); /* XXX */
+	}
+	newia->ia6_ndpr = ia0->ia6_ndpr;
+	newia->ia6_ndpr->ndpr_refcnt++;
+	ifa_free(&newia->ia_ifa);
+
+	/*
+	 * A newly added address might affect the status of other addresses.
+	 * XXX: when the temporary address is generated with a new public
+	 * address, the onlink check is redundant.  However, it would be safe
+	 * to do the check explicitly everywhere a new address is generated,
+	 * and, in fact, we surely need the check when we create a new
+	 * temporary address due to deprecation of an old temporary address.
+	 */
+	pfxlist_onlink_check();
+
+	return (0);
+}
+
+static int
+in6_init_prefix_ltimes(struct nd_prefix *ndpr)
+{
+	if (ndpr->ndpr_pltime == ND6_INFINITE_LIFETIME)
+		ndpr->ndpr_preferred = 0;
+	else
+		ndpr->ndpr_preferred = time_second + ndpr->ndpr_pltime;
+	if (ndpr->ndpr_vltime == ND6_INFINITE_LIFETIME)
+		ndpr->ndpr_expire = 0;
+	else
+		ndpr->ndpr_expire = time_second + ndpr->ndpr_vltime;
+
+	return 0;
+}
+
+static void
+in6_init_address_ltimes(struct nd_prefix *new, struct in6_addrlifetime *lt6)
+{
+	/* init ia6t_expire */
+	if (lt6->ia6t_vltime == ND6_INFINITE_LIFETIME)
+		lt6->ia6t_expire = 0;
+	else {
+		lt6->ia6t_expire = time_second;
+		lt6->ia6t_expire += lt6->ia6t_vltime;
+	}
+
+	/* init ia6t_preferred */
+	if (lt6->ia6t_pltime == ND6_INFINITE_LIFETIME)
+		lt6->ia6t_preferred = 0;
+	else {
+		lt6->ia6t_preferred = time_second;
+		lt6->ia6t_preferred += lt6->ia6t_pltime;
+	}
+}
+
+/*
+ * Delete all the routing table entries that use the specified gateway.
+ * XXX: this function causes search through all entries of routing table, so
+ * it shouldn't be called when acting as a router.
+ */
+void
+rt6_flush(struct in6_addr *gateway, struct ifnet *ifp)
+{
+	struct radix_node_head *rnh;
+	int s = splnet();
+
+	/* We'll care only link-local addresses */
+	if (!IN6_IS_ADDR_LINKLOCAL(gateway)) {
+		splx(s);
+		return;
+	}
+
+	rnh = rt_tables_get_rnh(0, AF_INET6);
+	if (rnh == NULL)
+		return;
+
+	RADIX_NODE_HEAD_LOCK(rnh);
+	rnh->rnh_walktree(rnh, rt6_deleteroute, (void *)gateway);
+	RADIX_NODE_HEAD_UNLOCK(rnh);
+	splx(s);
+}
+
+static int
+rt6_deleteroute(struct radix_node *rn, void *arg)
+{
+#define SIN6(s)	((struct sockaddr_in6 *)s)
+	struct rtentry *rt = (struct rtentry *)rn;
+	struct in6_addr *gate = (struct in6_addr *)arg;
+
+	if (rt->rt_gateway == NULL || rt->rt_gateway->sa_family != AF_INET6)
+		return (0);
+
+	if (!IN6_ARE_ADDR_EQUAL(gate, &SIN6(rt->rt_gateway)->sin6_addr)) {
+		return (0);
+	}
+
+	/*
+	 * Do not delete a static route.
+	 * XXX: this seems to be a bit ad-hoc. Should we consider the
+	 * 'cloned' bit instead?
+	 */
+	if ((rt->rt_flags & RTF_STATIC) != 0)
+		return (0);
+
+	/*
+	 * We delete only host route. This means, in particular, we don't
+	 * delete default route.
+	 */
+	if ((rt->rt_flags & RTF_HOST) == 0)
+		return (0);
+
+	return (rtrequest(RTM_DELETE, rt_key(rt), rt->rt_gateway,
+	    rt_mask(rt), rt->rt_flags, 0));
+#undef SIN6
+}
+
+int
+nd6_setdefaultiface(int ifindex)
+{
+	int error = 0;
+
+	if (ifindex < 0 || V_if_index < ifindex)
+		return (EINVAL);
+	if (ifindex != 0 && !ifnet_byindex(ifindex))
+		return (EINVAL);
+
+	if (V_nd6_defifindex != ifindex) {
+		V_nd6_defifindex = ifindex;
+		if (V_nd6_defifindex > 0)
+			V_nd6_defifp = ifnet_byindex(V_nd6_defifindex);
+		else
+			V_nd6_defifp = NULL;
+
+		/*
+		 * Our current implementation assumes one-to-one maping between
+		 * interfaces and links, so it would be natural to use the
+		 * default interface as the default link.
+		 */
+		scope6_setdefault(V_nd6_defifp);
+	}
+
+	return (error);
+}