text: /*	$KAME: in6.c,v 1.381 2004/08/17 10:18:57 jinmei Exp $	*/
  
  /*
   * Copyright (c) 2002 INRIA. All rights reserved.
   *
   * Implementation of Multicast Listener Discovery, Version 2.
   * Developed by Hitoshi Asaeda, INRIA, August 2002.
   *
   * 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 INRIA 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 INSTITUTE 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 INSTITUTE 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.
   */
  
  /*
   * 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.
   */
  
  /*
   * Copyright (c) 1982, 1986, 1991, 1993
   *	The Regents of the University of California.  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. All advertising materials mentioning features or use of this software
   *    must display the following acknowledgement:
   *	This product includes software developed by the University of
   *	California, Berkeley and its contributors.
   * 4. Neither the name of the University 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 REGENTS 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 REGENTS 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.
   *
   *	@(#)in.c	8.2 (Berkeley) 11/15/93
   */
  
  #ifdef __FreeBSD__
  #include "opt_inet.h"
  #include "opt_inet6.h"
  #include "opt_mip6.h"
  #endif
  #ifdef __NetBSD__
  #include "opt_inet.h"
  #include "opt_mip6.h"
  #endif
  
  #include <sys/param.h>
  #ifndef __FreeBSD__
  #include <sys/ioctl.h>
  #endif
  #include <sys/errno.h>
  #include <sys/malloc.h>
  #include <sys/socket.h>
  #include <sys/socketvar.h>
  #include <sys/sockio.h>
  #include <sys/systm.h>
  #ifndef __FreeBSD__
  #include <sys/proc.h>
  #endif
  #include <sys/time.h>
  #include <sys/kernel.h>
  #include <sys/syslog.h>
  
  #include <net/if.h>
  #include <net/if_types.h>
  #include <net/route.h>
  #include <net/if_dl.h>
  
  #include <netinet/in.h>
  #include <netinet/in_var.h>
  #ifdef __NetBSD__
  #include <net/if_ether.h>
  #else
  #include <netinet/if_ether.h>
  #endif
  #ifndef SCOPEDROUTING
  #if defined(__OpenBSD__) || defined(__FreeBSD__)
  #include <netinet/in_systm.h>
  #include <netinet/ip.h>
  #include <netinet/in_pcb.h>
  #endif
  #endif
  
  #ifdef __OpenBSD__
  #include <dev/rndvar.h>
  #endif
  
  #include <netinet/ip6.h>
  #include <netinet6/ip6_var.h>
  #include <netinet6/nd6.h>
  #include <netinet6/mld6_var.h>
  #include <netinet6/ip6_mroute.h>
  #include <netinet6/in6_ifattach.h>
  #include <netinet6/scope6_var.h>
  #ifndef SCOPEDROUTING
  #if defined(__NetBSD__) || defined(__FreeBSD__)
  #include <netinet6/in6_pcb.h>
  #endif
  #endif
  
  #ifdef MLDV2
  #include <netinet/icmp6.h>
  #include <netinet6/in6_msf.h>
  #endif
  
  #include "gif.h"
  #if NGIF > 0
  #include <net/if_gif.h>
  #endif
  
  #ifdef MIP6
  #include "mip.h"
  #include <netinet6/mip6.h>
  #include <netinet6/mip6_var.h>
  #if NMIP > 0
  #include <net/if_mip.h>
  #endif /* NMIP > 0 */
  #endif /* MIP6 */
  
  #include <net/net_osdep.h>
  
  #ifdef __FreeBSD__
  MALLOC_DEFINE(M_IPMADDR, "in6_multi", "internet multicast address");
  #endif
  
  /*
   * Definitions of some costant IP6 addresses.
   */
  const struct in6_addr in6addr_any = IN6ADDR_ANY_INIT;
  const struct in6_addr in6addr_loopback = IN6ADDR_LOOPBACK_INIT;
  const struct in6_addr in6addr_nodelocal_allnodes =
  	IN6ADDR_NODELOCAL_ALLNODES_INIT;
  const struct in6_addr in6addr_linklocal_allnodes =
  	IN6ADDR_LINKLOCAL_ALLNODES_INIT;
  const struct in6_addr in6addr_linklocal_allrouters =
  	IN6ADDR_LINKLOCAL_ALLROUTERS_INIT;
  #ifdef MLDV2
  const struct in6_addr in6addr_linklocal_allv2routers =
  	IN6ADDR_LINKLOCAL_ALLV2ROUTERS_INIT;
  #endif
  
  const struct in6_addr in6mask0 = IN6MASK0;
  const struct in6_addr in6mask32 = IN6MASK32;
  const struct in6_addr in6mask64 = IN6MASK64;
  const struct in6_addr in6mask96 = IN6MASK96;
  const struct in6_addr in6mask128 = IN6MASK128;
  
  const struct sockaddr_in6 sa6_any =
  	{ sizeof(sa6_any), AF_INET6, 0, 0, IN6ADDR_ANY_INIT, 0};
  
  #if defined(__FreeBSD__) && __FreeBSD_version >= 500000
  static int in6_lifaddr_ioctl(struct socket *, u_long, caddr_t,
  	struct ifnet *, struct thread *);
  #else
  static int in6_lifaddr_ioctl __P((struct socket *, u_long, caddr_t,
  	struct ifnet *, struct proc *));
  #endif
  static int in6_ifinit __P((struct ifnet *, struct in6_ifaddr *,
  	struct sockaddr_in6 *, int));
  static void in6_unlink_ifa __P((struct in6_ifaddr *, struct ifnet *));
  
  #ifdef __FreeBSD__
  int	(*faithprefix_p)(struct in6_addr *);
  #endif
  
  /*
   * Subroutine for in6_ifaddloop() and in6_ifremloop().
   * This routine does actual work.
   */
  static void
  in6_ifloop_request(int cmd, struct ifaddr *ifa)
  {
  	struct sockaddr_in6 all1_sa;
  	struct rtentry *nrt = NULL;
  	int e;
  
  	bzero(&all1_sa, sizeof(all1_sa));
  	all1_sa.sin6_family = AF_INET6;
  	all1_sa.sin6_len = sizeof(struct sockaddr_in6);
  	all1_sa.sin6_addr = in6mask128;
  
  	/*
  	 * We specify the address itself as the gateway, and set the
  	 * RTF_LLINFO flag, so that the corresponding host route would have
  	 * the flag, and thus applications that assume traditional behavior
  	 * would be happy.  Note that we assume the caller of the function
  	 * (probably implicitly) set nd6_rtrequest() to ifa->ifa_rtrequest,
  	 * which changes the outgoing interface to the loopback interface.
  	 */
  	e = rtrequest(cmd, ifa->ifa_addr, ifa->ifa_addr,
  	    (struct sockaddr *)&all1_sa, RTF_UP|RTF_HOST|RTF_LLINFO, &nrt);
  	if (e != 0) {
  		/* XXX need more descriptive message */
  		log(LOG_ERR, "in6_ifloop_request: "
  		    "%s operation failed for %s (errno=%d)\n",
  		    cmd == RTM_ADD ? "ADD" : "DELETE",
  		    ip6_sprintf(&((struct in6_ifaddr *)ifa)->ia_addr.sin6_addr),
  		    e);
  	}
  
  	/*
  	 * Make sure rt_ifa be equal to IFA, the second argument of the
  	 * function.
  	 * We need this because when we refer to rt_ifa->ia6_flags in
  	 * ip6_input, we assume that the rt_ifa points to the address instead
  	 * of the loopback address.
  	 */
  	if (cmd == RTM_ADD && nrt && ifa != nrt->rt_ifa) {
  		IFAFREE(nrt->rt_ifa);
  		IFAREF(ifa);
  		nrt->rt_ifa = ifa;
  	}
  
  	/*
  	 * Report the addition/removal of the address to the routing socket.
  	 * XXX: since we called rtinit for a p2p interface with a destination,
  	 *      we end up reporting twice in such a case.  Should we rather
  	 *      omit the second report?
  	 */
  	if (nrt) {
  #if defined(__FreeBSD__) && __FreeBSD_version >= 502010
  		RT_LOCK(nrt);
  #endif
  		rt_newaddrmsg(cmd, ifa, e, nrt);
  #if defined(__FreeBSD__) && __FreeBSD_version >= 502010
  		if (cmd == RTM_DELETE) {
  			rtfree(nrt);
  		} else {
  			/* the cmd must be RTM_ADD here */
  			RT_REMREF(nrt);
  			RT_UNLOCK(nrt);
  		}
  #else
  		if (cmd == RTM_DELETE) {
  			if (nrt->rt_refcnt <= 0) {
  				/* XXX: we should free the entry ourselves. */
  				nrt->rt_refcnt++;
  				rtfree(nrt);
  			}
  		} else {
  			/* the cmd must be RTM_ADD here */
  			nrt->rt_refcnt--;
  		}
  #endif
  	}
  }
  
  /*
   * Add ownaddr as loopback rtentry.  We previously add the route only if
   * necessary (ex. on a p2p link).  However, since we now manage addresses
   * separately from prefixes, we should always add the route.  We can't
   * rely on the cloning mechanism from the corresponding interface route
   * any more.
   */
  static void
  in6_ifaddloop(struct ifaddr *ifa)
  {
  	struct rtentry *rt;
  	int need_loop;
  
  	/* If there is no loopback entry, allocate one. */
  	rt = rtalloc1(ifa->ifa_addr, 0
  #ifdef __FreeBSD__
  		      , 0
  #endif /* __FreeBSD__ */
  		);
  
  	need_loop = (rt == NULL || (rt->rt_flags & RTF_HOST) == 0 ||
  	    (rt->rt_ifp->if_flags & IFF_LOOPBACK) == 0);
  
  	if (rt)
  		rtfree(rt);
  	if (need_loop) {
  		in6_ifloop_request(RTM_ADD, ifa);
  	}
  }
  
  /*
   * Remove loopback rtentry of ownaddr generated by in6_ifaddloop(),
   * if it exists.
   */
  static void
  in6_ifremloop(struct ifaddr *ifa)
  {
  	struct in6_ifaddr *ia;
  	struct rtentry *rt;
  	int ia_count = 0;
  
  	/*
  	 * Some of BSD variants do not remove cloned routes
  	 * from an interface direct route, when removing the direct route
  	 * (see comments in net/net_osdep.h).  Even for variants that do remove
  	 * cloned routes, they could fail to remove the cloned routes when
  	 * we handle multple addresses that share a common prefix.
  	 * So, we should remove the route corresponding to the deleted address.
  	 */
  
  	/*
  	 * Delete the entry only if exact one ifa exists.  More than one ifa
  	 * can exist if we assign a same single address to multiple
  	 * (probably p2p) interfaces.
  	 * XXX: we should avoid such a configuration in IPv6...
  	 */
  	for (ia = in6_ifaddr; ia; ia = ia->ia_next) {
  		if (IN6_ARE_ADDR_EQUAL(IFA_IN6(ifa), &ia->ia_addr.sin6_addr)) {
  			ia_count++;
  			if (ia_count > 1)
  				break;
  		}
  	}
  
  	if (ia_count == 1) {
  		/*
  		 * Before deleting, check if a corresponding loopbacked host
  		 * route surely exists.  With this check, we can avoid to
  		 * delete an interface direct route whose destination is same
  		 * as the address being removed.  This can happen when removing
  		 * a subnet-router anycast address on an interface attahced
  		 * to a shared medium.
  		 */
  		rt = rtalloc1(ifa->ifa_addr, 0
  #ifdef __FreeBSD__
  			      , 0
  #endif /* __FreeBSD__ */
  			);
  #if defined(__FreeBSD__) && __FreeBSD_version >= 502010
  		if (rt != NULL) {
  			if ((rt->rt_flags & RTF_HOST) != 0 &&
  			    (rt->rt_ifp->if_flags & IFF_LOOPBACK) != 0) {
  				rtfree(rt);
  				in6_ifloop_request(RTM_DELETE, ifa);
  			} else
  				RT_UNLOCK(rt);
  		}
  #else
  		if (rt != NULL && (rt->rt_flags & RTF_HOST) != 0 &&
  		    (rt->rt_ifp->if_flags & IFF_LOOPBACK) != 0) {
  			rt->rt_refcnt--;
  			in6_ifloop_request(RTM_DELETE, ifa);
  		}
  #endif
  	}
  }
  
  int
  in6_mask2len(mask, lim0)
  	struct in6_addr *mask;
  	u_char *lim0;
  {
  	int x = 0, y;
  	u_char *lim = lim0, *p;
  
  	/* ignore the scope_id part */
  	if (lim0 == NULL || lim0 - (u_char *)mask > sizeof(*mask))
  		lim = (u_char *)mask + sizeof(*mask);
  	for (p = (u_char *)mask; p < lim; x++, p++) {
  		if (*p != 0xff)
  			break;
  	}
  	y = 0;
  	if (p < lim) {
  		for (y = 0; y < 8; y++) {
  			if ((*p & (0x80 >> y)) == 0)
  				break;
  		}
  	}
  
  	/*
  	 * when the limit pointer is given, do a stricter check on the
  	 * remaining bits.
  	 */
  	if (p < lim) {
  		if (y != 0 && (*p & (0x00ff >> y)) != 0)
  			return (-1);
  		for (p = p + 1; p < lim; p++)
  			if (*p != 0)
  				return (-1);
  	}
  
  	return x * 8 + y;
  }
  
  #define ifa2ia6(ifa)	((struct in6_ifaddr *)(ifa))
  #define ia62ifa(ia6)	(&((ia6)->ia_ifa))
  
  int
  #if defined(__FreeBSD__) && __FreeBSD_version >= 500000
  in6_control(so, cmd, data, ifp, p)
  	struct	socket *so;
  	u_long cmd;
  	caddr_t	data;
  	struct ifnet *ifp;
  	struct thread *p;
  #else
  in6_control(so, cmd, data, ifp, p)
  	struct	socket *so;
  	u_long cmd;
  	caddr_t	data;
  	struct ifnet *ifp;
  	struct proc *p;
  #endif
  {
  	struct	in6_ifreq *ifr = (struct in6_ifreq *)data;
  	struct	in6_ifaddr *ia = NULL;
  	struct	in6_aliasreq *ifra = (struct in6_aliasreq *)data;
  	struct sockaddr_in6 *sa6;
  #ifndef __FreeBSD__
  	time_t time_second = (time_t)time.tv_sec;
  #endif
  	int privileged;
  
  	privileged = 0;
  #if defined(__NetBSD__)
  	if (p && !suser(p->p_ucred, &p->p_acflag))
  		privileged++;
  #elif defined(__FreeBSD__)
  	if (p == NULL || !suser(p))
  		privileged++;
  #else
  	if ((so->so_state & SS_PRIV) != 0)
  		privileged++;
  #endif
  
  	switch (cmd) {
  	case SIOCGETSGCNT_IN6:
  	case SIOCGETMIFCNT_IN6:
  		return (mrt6_ioctl(cmd, data));
  #ifdef MLDV2
  	case SIOCSMSFILTER:
  		/* Set Protocol-Independent Multicast Source Filter */
  		return (sock6_setmopt_srcfilter(so, (struct group_filter **)data));
  
  	case SIOCGMSFILTER:
  		/* Get Protocol-Independent Multicast Source Filter */
  		return (sock6_getmopt_srcfilter(so, (struct group_filter **)data));
  #endif
  	}
  
  	switch(cmd) {
  	case SIOCAADDRCTL_POLICY:
  	case SIOCDADDRCTL_POLICY:
  		if (!privileged)
  			return (EPERM);
  		return (in6_src_ioctl(cmd, data));
  	}
  
  	if (ifp == NULL)
  		return (EOPNOTSUPP);
  
  	switch (cmd) {
  	case SIOCSNDFLUSH_IN6:
  	case SIOCSPFXFLUSH_IN6:
  	case SIOCSRTRFLUSH_IN6:
  	case SIOCSDEFIFACE_IN6:
  	case SIOCSIFINFO_FLAGS:
  		if (!privileged)
  			return (EPERM);
  		/* FALLTHROUGH */
  	case OSIOCGIFINFO_IN6:
  	case SIOCGIFINFO_IN6:
  	case SIOCGDRLST_IN6:
  	case SIOCGPRLST_IN6:
  	case SIOCGNBRINFO_IN6:
  	case SIOCGDEFIFACE_IN6:
  		return (nd6_ioctl(cmd, data, ifp));
  	}
  
  	switch (cmd) {
  	case SIOCSIFPREFIX_IN6:
  	case SIOCDIFPREFIX_IN6:
  	case SIOCAIFPREFIX_IN6:
  	case SIOCCIFPREFIX_IN6:
  	case SIOCSGIFPREFIX_IN6:
  	case SIOCGIFPREFIX_IN6:
  		log(LOG_NOTICE,
  		    "prefix ioctls are now invalidated. "
  		    "please use ifconfig.\n");
  		return (EOPNOTSUPP);
  	}
  
  	switch (cmd) {
  	case SIOCSSCOPE6:
  		if (!privileged)
  			return (EPERM);
  		return (scope6_set(ifp,
  		    (struct scope6_id *)ifr->ifr_ifru.ifru_scope_id));
  	case SIOCGSCOPE6:
  		return (scope6_get(ifp,
  		    (struct scope6_id *)ifr->ifr_ifru.ifru_scope_id));
  	case SIOCGSCOPE6DEF:
  		return (scope6_get_default((struct scope6_id *)
  		    ifr->ifr_ifru.ifru_scope_id));
  	}
  
  	switch (cmd) {
  	case SIOCALIFADDR:
  	case SIOCDLIFADDR:
  		if (!privileged)
  			return (EPERM);
  		/* FALLTHROUGH */
  	case SIOCGLIFADDR:
  		return in6_lifaddr_ioctl(so, cmd, data, ifp, p);
  	}
  
  	/*
  	 * Find address for this interface, if it exists.
  	 *
  	 * In netinet code, we have checked ifra_addr in SIOCSIF*ADDR operation
  	 * only, and used the first interface address as the target of other
  	 * operations (without checking ifra_addr).  This was because netinet
  	 * code/API assumed at most 1 interface address per interface.
  	 * Since IPv6 allows a node to assign multiple addresses
  	 * on a single interface, we almost always look and check the
  	 * presence of ifra_addr, and reject invalid ones here.
  	 * It also decreases duplicated code among SIOC*_IN6 operations.
  	 */
  	switch (cmd) {
  	case SIOCAIFADDR_IN6:
  	case SIOCSIFPHYADDR_IN6:
  		sa6 = &ifra->ifra_addr;
  		break;
  	case SIOCSIFADDR_IN6:
  	case SIOCGIFADDR_IN6:
  	case SIOCSIFDSTADDR_IN6:
  	case SIOCSIFNETMASK_IN6:
  	case SIOCGIFDSTADDR_IN6:
  	case SIOCGIFNETMASK_IN6:
  	case SIOCDIFADDR_IN6:
  	case SIOCGIFPSRCADDR_IN6:
  	case SIOCGIFPDSTADDR_IN6:
  	case SIOCGIFAFLAG_IN6:
  	case SIOCSNDFLUSH_IN6:
  	case SIOCSPFXFLUSH_IN6:
  	case SIOCSRTRFLUSH_IN6:
  	case SIOCGIFALIFETIME_IN6:
  	case SIOCSIFALIFETIME_IN6:
  	case SIOCGIFSTAT_IN6:
  	case SIOCGIFSTAT_ICMP6:
  		sa6 = &ifr->ifr_addr;
  		break;
  	default:
  		sa6 = NULL;
  		break;
  	}
  	if (sa6 && sa6->sin6_family == AF_INET6) {
  		if (IN6_IS_ADDR_LINKLOCAL(&sa6->sin6_addr)) {
  			if (sa6->sin6_addr.s6_addr16[1] == 0) {
  				/* link ID is not embedded by the user */
  				sa6->sin6_addr.s6_addr16[1] =
  				    htons(ifp->if_index);
  			} else if (sa6->sin6_addr.s6_addr16[1] !=
  			    htons(ifp->if_index)) {
  				return (EINVAL);	/* link ID contradicts */
  			}
  			if (sa6->sin6_scope_id) {
  				if (sa6->sin6_scope_id !=
  				    (u_int32_t)ifp->if_index)
  					return (EINVAL);
  				sa6->sin6_scope_id = 0; /* XXX: good way? */
  			}
  		}
  		ia = in6ifa_ifpwithaddr(ifp, &sa6->sin6_addr);
  	} else
  		ia = NULL;
  
  	switch (cmd) {
  	case SIOCSIFADDR_IN6:
  	case SIOCSIFDSTADDR_IN6:
  	case SIOCSIFNETMASK_IN6:
  		/*
  		 * Since IPv6 allows a node to assign multiple addresses
  		 * on a single interface, SIOCSIFxxx ioctls are deprecated.
  		 */
  		return (EINVAL);
  
  	case SIOCDIFADDR_IN6:
  		/*
  		 * for IPv4, we look for existing in_ifaddr here to allow
  		 * "ifconfig if0 delete" to remove the first IPv4 address on
  		 * the interface.  For IPv6, as the spec allows multiple
  		 * interface address from the day one, we consider "remove the
  		 * first one" semantics to be not preferable.
  		 */
  		if (ia == NULL)
  			return (EADDRNOTAVAIL);
  		/* FALLTHROUGH */
  	case SIOCAIFADDR_IN6:
  		/*
  		 * We always require users to specify a valid IPv6 address for
  		 * the corresponding operation.
  		 */
  		if (ifra->ifra_addr.sin6_family != AF_INET6 ||
  		    ifra->ifra_addr.sin6_len != sizeof(struct sockaddr_in6))
  			return (EAFNOSUPPORT);
  		if (!privileged)
  			return (EPERM);
  
  		break;
  
  	case SIOCGIFADDR_IN6:
  		/* This interface is basically deprecated. use SIOCGIFCONF. */
  		/* FALLTHROUGH */
  	case SIOCGIFAFLAG_IN6:
  	case SIOCGIFNETMASK_IN6:
  	case SIOCGIFDSTADDR_IN6:
  	case SIOCGIFALIFETIME_IN6:
  		/* must think again about its semantics */
  		if (ia == NULL)
  			return (EADDRNOTAVAIL);
  		break;
  	case SIOCSIFALIFETIME_IN6:
  	    {
  		struct in6_addrlifetime *lt;
  
  		if (!privileged)
  			return (EPERM);
  		if (ia == NULL)
  			return (EADDRNOTAVAIL);
  		/* sanity for overflow - beware unsigned */
  		lt = &ifr->ifr_ifru.ifru_lifetime;
  		if (lt->ia6t_vltime != ND6_INFINITE_LIFETIME &&
  		    lt->ia6t_vltime + time_second < time_second) {
  			return EINVAL;
  		}
  		if (lt->ia6t_pltime != ND6_INFINITE_LIFETIME &&
  		    lt->ia6t_pltime + time_second < time_second) {
  			return EINVAL;
  		}
  		break;
  	    }
  	}
  
  	switch (cmd) {
  
  	case SIOCGIFADDR_IN6:
  		ifr->ifr_addr = ia->ia_addr;
  		break;
  
  	case SIOCGIFDSTADDR_IN6:
  		if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
  			return (EINVAL);
  		/*
  		 * XXX: should we check if ifa_dstaddr is NULL and return
  		 * an error?
  		 */
  		ifr->ifr_dstaddr = ia->ia_dstaddr;
  		break;
  
  	case SIOCGIFNETMASK_IN6:
  		ifr->ifr_addr = ia->ia_prefixmask;
  		break;
  
  	case SIOCGIFAFLAG_IN6:
  		ifr->ifr_ifru.ifru_flags6 = ia->ia6_flags;
  		break;
  
  	case SIOCGIFSTAT_IN6:
  		if (ifp == NULL)
  			return EINVAL;
  		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;
  		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:
  		ifr->ifr_ifru.ifru_lifetime = ia->ia6_lifetime;
  		if (ia->ia6_lifetime.ia6t_vltime != ND6_INFINITE_LIFETIME) {
  			time_t maxexpire;
  			struct in6_addrlifetime *retlt =
  			    &ifr->ifr_ifru.ifru_lifetime;
  
  			/*
  			 * XXX: adjust expiration time assuming time_t is
  			 * signed.
  			 */
  			maxexpire = (-1) &
  			    ~(1 << ((sizeof(maxexpire) * 8) - 1));
  			if (ia->ia6_lifetime.ia6t_vltime <
  			    maxexpire - ia->ia6_updatetime) {
  				retlt->ia6t_expire = ia->ia6_updatetime +
  				    ia->ia6_lifetime.ia6t_vltime;
  			} else
  				retlt->ia6t_expire = maxexpire;
  		}
  		if (ia->ia6_lifetime.ia6t_pltime != ND6_INFINITE_LIFETIME) {
  			time_t maxexpire;
  			struct in6_addrlifetime *retlt =
  			    &ifr->ifr_ifru.ifru_lifetime;
  
  			/*
  			 * XXX: adjust expiration time assuming time_t is
  			 * signed.
  			 */
  			maxexpire = (-1) &
  			    ~(1 << ((sizeof(maxexpire) * 8) - 1));
  			if (ia->ia6_lifetime.ia6t_pltime <
  			    maxexpire - ia->ia6_updatetime) {
  				retlt->ia6t_preferred = ia->ia6_updatetime +
  				    ia->ia6_lifetime.ia6t_pltime;
  			} else
  				retlt->ia6t_preferred = maxexpire;
  		}
  		break;
  
  	case SIOCSIFALIFETIME_IN6:
  		ia->ia6_lifetime = ifr->ifr_ifru.ifru_lifetime;
  		/* for sanity */
  		if (ia->ia6_lifetime.ia6t_vltime != ND6_INFINITE_LIFETIME) {
  			ia->ia6_lifetime.ia6t_expire =
  				time_second + ia->ia6_lifetime.ia6t_vltime;
  		} else
  			ia->ia6_lifetime.ia6t_expire = 0;
  		if (ia->ia6_lifetime.ia6t_pltime != ND6_INFINITE_LIFETIME) {
  			ia->ia6_lifetime.ia6t_preferred =
  				time_second + ia->ia6_lifetime.ia6t_pltime;
  		} else
  			ia->ia6_lifetime.ia6t_preferred = 0;
  		break;
  
  	case SIOCAIFADDR_IN6:
  	{
  		int i, error = 0;
  		struct nd_prefixctl pr0;
  		struct nd_prefix *pr;
  
  		/* reject read-only flags */
  		if ((ifra->ifra_flags & IN6_IFF_READONLY))
  			return (EINVAL);
  
  		/*
  		 * when trying to change flags on an existing interface
  		 * address, make sure to preserve old read-only ones.
  		 */
  		if (ia)
  			ifra->ifra_flags |= (ia->ia6_flags & IN6_IFF_READONLY);
  
  		/*
  		 * first, make or update the interface address structure,
  		 * and link it to the list.
  		 */
  		if ((error = in6_update_ifa(ifp, ifra, ia, 0)) != 0)
  			return (error);
  		if ((ia = in6ifa_ifpwithaddr(ifp, &ifra->ifra_addr.sin6_addr))
  		    == NULL) {
  		    	/*
  			 * this can happen when the user specify the 0 valid
  			 * lifetime.
  			 */
  			break;
  		}
  
  		/*
  		 * then, make the prefix on-link on the interface.
  		 * XXX: we'd rather create the prefix before the address, but
  		 * we need at least one address to install the corresponding
  		 * interface route, so we configure the address first.
  		 */
  
  		/*
  		 * convert mask to prefix length (prefixmask has already
  		 * been validated in in6_update_ifa().
  		 */
  		bzero(&pr0, sizeof(pr0));
  		pr0.ndpr_ifp = ifp;
  		pr0.ndpr_plen = in6_mask2len(&ifra->ifra_prefixmask.sin6_addr,
  		    NULL);
  		if (pr0.ndpr_plen == 128) {
  			break;	/* we don't need to install a host route. */
  #if defined(MIP6) && NMIP > 0
  		} else if ((ia->ia6_flags & IN6_IFF_HOME) && (ifp->if_type == IFT_MIP)) {
  			break;  /* we don't need to install a interface route. for home address */
  #endif 
  		}
  		pr0.ndpr_prefix = ifra->ifra_addr;
  		/* apply the mask for safety. */
  		for (i = 0; i < 4; i++) {
  			pr0.ndpr_prefix.sin6_addr.s6_addr32[i] &=
  			    ifra->ifra_prefixmask.sin6_addr.s6_addr32[i];
  		}
  		/*
  		 * XXX: since we don't have an API to set prefix (not address)
  		 * lifetimes, we just use the same lifetimes as addresses.
  		 * The (temporarily) installed lifetimes can be overridden by
  		 * later advertised RAs (when accept_rtadv is non 0), which is
  		 * an intended behavior.
  		 */
  		pr0.ndpr_raf_onlink = 1; /* should be configurable? */
  		pr0.ndpr_raf_auto =
  		    ((ifra->ifra_flags & IN6_IFF_AUTOCONF) != 0);
  		pr0.ndpr_vltime = ifra->ifra_lifetime.ia6t_vltime;
  		pr0.ndpr_pltime = ifra->ifra_lifetime.ia6t_pltime;
  
  		/* add the prefix if not yet. */
  		if ((pr = nd6_prefix_lookup(&pr0)) == NULL) {
  			/*
  			 * nd6_prelist_add will install the corresponding
  			 * interface route.
  			 */
  			if ((error = nd6_prelist_add(&pr0, NULL, &pr)) != 0)
  				return (error);
  			if (pr == NULL) {
  				log(LOG_ERR, "nd6_prelist_add succeeded but "
  				    "no prefix\n");
  				return (EINVAL); /* XXX panic here? */
  			}
  		}
  
  		/* relate the address to the prefix */
  		if (ia->ia6_ndpr == NULL) {
  			ia->ia6_ndpr = pr;
  			pr->ndpr_refcnt++;
  
  			/*
  			 * If this is the first autoconf address from the
  			 * prefix, create a temporary address as well
  			 * (when required).
  			 */
  			if ((ia->ia6_flags & IN6_IFF_AUTOCONF) &&
  			    ip6_use_tempaddr && pr->ndpr_refcnt == 1) {
  				int e;
  				if ((e = in6_tmpifadd(ia, 1, 0)) != 0) {
  					log(LOG_NOTICE, "in6_control: failed "
  					    "to create a temporary address, "
  					    "errno=%d\n", e);
  				}
  			}
  		}
  
  		/*
  		 * this might affect the status of autoconfigured addresses,
  		 * that is, this address might make other addresses detached.
  		 */
  		pfxlist_onlink_check();
  #if defined(__FreeBSD__) && __FreeBSD_version >= 503000
  		if (error == 0 && ia)
  			EVENTHANDLER_INVOKE(ifaddr_event, ifp);
  #endif
  		break;
  	}
  
  	case SIOCDIFADDR_IN6:
  	{
  		struct nd_prefix *pr;
  
  		/*
  		 * If the address being deleted is the only one that owns
  		 * the corresponding prefix, expire the prefix as well.
  		 * XXX: theoretically, we don't have to worry about such
  		 * relationship, since we separate the address management
  		 * and the prefix management.  We do this, however, to provide
  		 * as much backward compatibility as possible in terms of
  		 * the ioctl operation.
  		 * Note that in6_purgeaddr() will decrement ndpr_refcnt.
  		 */
  		pr = ia->ia6_ndpr;
  		in6_purgeaddr(&ia->ia_ifa);
  		if (pr && pr->ndpr_refcnt == 0)
  			prelist_remove(pr);
  #if defined(__FreeBSD__) && __FreeBSD_version >= 503000
  		EVENTHANDLER_INVOKE(ifaddr_event, ifp);
  #endif
  		break;
  	}
  
  	default:
  		if (ifp == NULL || ifp->if_ioctl == 0)
  			return (EOPNOTSUPP);
  		return ((*ifp->if_ioctl)(ifp, cmd, data));
  	}
  
  	return (0);
  }
  
  /*
   * Update parameters of an IPv6 interface address.
   * If necessary, a new entry is created and linked into address chains.
   * This function is separated from in6_control().
   * XXX: should this be performed under splnet()?
   */
  int
  in6_update_ifa(ifp, ifra, ia, flags)
  	struct ifnet *ifp;
  	struct in6_aliasreq *ifra;
  	struct in6_ifaddr *ia;
  	int flags;
  {
  	int error = 0, hostIsNew = 0, plen = -1;
  	struct in6_ifaddr *oia;
  	struct sockaddr_in6 dst6;
  	struct in6_addrlifetime *lt;
  	struct in6_multi_mship *imm;
  	struct in6_multi *in6m_sol;
  #ifndef __FreeBSD__
  	time_t time_second = (time_t)time.tv_sec;
  #endif
  	struct rtentry *rt;
  	int delay;
  
  	/* Validate parameters */
  	if (ifp == NULL || ifra == NULL) /* this maybe redundant */
  		return (EINVAL);
  
  	/*
  	 * The destination address for a p2p link must have a family
  	 * of AF_UNSPEC or AF_INET6.
  	 */
  	if ((ifp->if_flags & IFF_POINTOPOINT) != 0 &&
  	    ifra->ifra_dstaddr.sin6_family != AF_INET6 &&
  	    ifra->ifra_dstaddr.sin6_family != AF_UNSPEC)
  		return (EAFNOSUPPORT);
  	/*
  	 * validate ifra_prefixmask.  don't check sin6_family, netmask
  	 * does not carry fields other than sin6_len.
  	 */
  	if (ifra->ifra_prefixmask.sin6_len > sizeof(struct sockaddr_in6))
  		return (EINVAL);
  	/*
  	 * Because the IPv6 address architecture is classless, we require
  	 * users to specify a (non 0) prefix length (mask) for a new address.
  	 * We also require the prefix (when specified) mask is valid, and thus
  	 * reject a non-consecutive mask.
  	 */
  	if (ia == NULL && ifra->ifra_prefixmask.sin6_len == 0)
  		return (EINVAL);
  	if (ifra->ifra_prefixmask.sin6_len != 0) {
  		plen = in6_mask2len(&ifra->ifra_prefixmask.sin6_addr,
  		    (u_char *)&ifra->ifra_prefixmask +
  		    ifra->ifra_prefixmask.sin6_len);
  		if (plen <= 0)
  			return (EINVAL);
  	} else {
  		/*
  		 * In this case, ia must not be NULL.  We just use its prefix
  		 * length.
  		 */
  		plen = in6_mask2len(&ia->ia_prefixmask.sin6_addr, NULL);
  	}
  	/*
  	 * If the destination address on a p2p interface is specified,
  	 * and the address is a scoped one, validate/set the scope
  	 * zone identifier.
  	 */
  	dst6 = ifra->ifra_dstaddr;
  	if ((ifp->if_flags & (IFF_POINTOPOINT|IFF_LOOPBACK)) != 0 &&
  	    (dst6.sin6_family == AF_INET6)) {
  		u_int32_t zoneid;
  
  #ifndef SCOPEDROUTING
  		if ((error = in6_recoverscope(&dst6,
  		    &ifra->ifra_dstaddr.sin6_addr, ifp)) != 0)
  			return (error);
  #endif
  		if (in6_addr2zoneid(ifp, &dst6.sin6_addr, &zoneid))
  			return (EINVAL);
  		if (dst6.sin6_scope_id == 0) /* user omit to specify the ID. */
  			dst6.sin6_scope_id = zoneid;
  		else if (dst6.sin6_scope_id != zoneid)
  			return (EINVAL); /* scope ID mismatch. */
  		if ((error = in6_embedscope(&dst6.sin6_addr, &dst6)) != 0)
  			return (error);
  #ifndef SCOPEDROUTING
  		dst6.sin6_scope_id = 0; /* XXX */
  #endif
  	}
  	/*
  	 * The destination address can be specified only for a p2p or a
  	 * loopback interface.  If specified, the corresponding prefix length
  	 * must be 128.
  	 */
  	if (ifra->ifra_dstaddr.sin6_family == AF_INET6) {
  #ifdef FORCE_P2PPLEN
  		int i;
  #endif
  
  		if ((ifp->if_flags & (IFF_POINTOPOINT|IFF_LOOPBACK)) == 0) {
  			/* XXX: noisy message */
  			nd6log((LOG_INFO, "in6_update_ifa: a destination can "
  			    "be specified for a p2p or a loopback IF only\n"));
  			return (EINVAL);
  		}
  		if (plen != 128) {
  			nd6log((LOG_INFO, "in6_update_ifa: prefixlen should "
  			    "be 128 when dstaddr is specified\n"));
  #ifdef FORCE_P2PPLEN
  			/*
  			 * To be compatible with old configurations,
  			 * such as ifconfig gif0 inet6 2001::1 2001::2
  			 * prefixlen 126, we override the specified
  			 * prefixmask as if the prefix length was 128.
  			 */
  			ifra->ifra_prefixmask.sin6_len =
  			    sizeof(struct sockaddr_in6);
  			for (i = 0; i < 4; i++)
  				ifra->ifra_prefixmask.sin6_addr.s6_addr32[i] =
  				    0xffffffff;
  			plen = 128;
  #else
  			return (EINVAL);
  #endif
  		}
  	}
  	/* lifetime consistency check */
  	lt = &ifra->ifra_lifetime;
  	if (lt->ia6t_pltime > lt->ia6t_vltime)
  		return (EINVAL);
  	if (lt->ia6t_vltime == 0) {
  		/*
  		 * the following log might be noisy, but this is a typical
  		 * configuration mistake or a tool's bug.
  		 */
  		nd6log((LOG_INFO,
  		    "in6_update_ifa: valid lifetime is 0 for %s\n",
  		    ip6_sprintf(&ifra->ifra_addr.sin6_addr)));
  
  		if (ia == NULL)
  			return (0); /* there's nothing to do */
  	}
  
  	/*
  	 * If this is a new address, allocate a new ifaddr and link it
  	 * into chains.
  	 */
  	if (ia == NULL) {
  		hostIsNew = 1;
  		/*
  		 * When in6_update_ifa() is called in a process of a received
  		 * RA, it is called under an interrupt context.  So, we should
  		 * call malloc with M_NOWAIT.
  		 */
  		ia = (struct in6_ifaddr *) malloc(sizeof(*ia), M_IFADDR,
  		    M_NOWAIT);
  		if (ia == NULL)
  			return (ENOBUFS);
  		bzero((caddr_t)ia, sizeof(*ia));
  		LIST_INIT(&ia->ia6_memberships);
  #if defined(MIP6) && NMIP > 0
  		LIST_INIT(&ia->ia6_mbul_list);
  #endif /* MIP6 && NMIP > 0 */
  		/* Initialize the address and masks, and put time stamp */
  #if defined(__FreeBSD__) && (__FreeBSD_version >= 501000)
  		IFA_LOCK_INIT(&ia->ia_ifa);
  #endif
  		ia->ia_ifa.ifa_addr = (struct sockaddr *)&ia->ia_addr;
  		ia->ia_addr.sin6_family = AF_INET6;
  		ia->ia_addr.sin6_len = sizeof(ia->ia_addr);
  		ia->ia6_createtime = ia->ia6_updatetime = time_second;
  		if ((ifp->if_flags & (IFF_POINTOPOINT | IFF_LOOPBACK)) != 0) {
  			/*
  			 * XXX: some functions expect that ifa_dstaddr is not
  			 * NULL for p2p interfaces.
  			 */
  			ia->ia_ifa.ifa_dstaddr =
  			    (struct sockaddr *)&ia->ia_dstaddr;
  		} else {
  			ia->ia_ifa.ifa_dstaddr = NULL;
  		}
  		ia->ia_ifa.ifa_netmask = (struct sockaddr *)&ia->ia_prefixmask;
  
  		ia->ia_ifp = ifp;
  		if ((oia = in6_ifaddr) != NULL) {
  			for ( ; oia->ia_next; oia = oia->ia_next)
  				continue;
  			oia->ia_next = ia;
  		} else
  			in6_ifaddr = ia;
  #if defined(__NetBSD__) || (defined(__FreeBSD__) && __FreeBSD_version >= 502010)
  		/* gain a refcnt for the link from in6_ifaddr */
  		IFAREF(&ia->ia_ifa);
  #endif
  
  		TAILQ_INSERT_TAIL(&ifp->if_addrlist, &ia->ia_ifa, ifa_list);
  	}
  
  	/* set prefix mask */
  	if (ifra->ifra_prefixmask.sin6_len) {
  		/*
  		 * We prohibit changing the prefix length of an existing
  		 * address, because
  		 * + such an operation should be rare in IPv6, and
  		 * + the operation would confuse prefix management.
  		 */
  		if (ia->ia_prefixmask.sin6_len &&
  		    in6_mask2len(&ia->ia_prefixmask.sin6_addr, NULL) != plen) {
  			nd6log((LOG_INFO, "in6_update_ifa: the plen of an "
  			    " existing (%s) address should not be changed\n",
  			    ip6_sprintf(&ia->ia_addr.sin6_addr)));
  			error = EINVAL;
  			goto unlink;
  		}
  		ia->ia_prefixmask = ifra->ifra_prefixmask;
  	}
  
  	/*
  	 * If a new destination address is specified, scrub the old one and
  	 * install the new destination.  Note that the interface must be
  	 * p2p or loopback (see the check above.)
  	 */
  	if (dst6.sin6_family == AF_INET6 &&
  	    !IN6_ARE_ADDR_EQUAL(&dst6.sin6_addr, &ia->ia_dstaddr.sin6_addr)) {
  		int e;
  
  		if ((ia->ia_flags & IFA_ROUTE) != 0 &&
  		    (e = rtinit(&(ia->ia_ifa), (int)RTM_DELETE, RTF_HOST)) != 0) {
  			nd6log((LOG_ERR, "in6_update_ifa: failed to remove "
  			    "a route to the old destination: %s\n",
  			    ip6_sprintf(&ia->ia_addr.sin6_addr)));
  			/* proceed anyway... */
  		} else
  			ia->ia_flags &= ~IFA_ROUTE;
  		ia->ia_dstaddr = dst6;
  	}
  
  	/*
  	 * Set lifetimes.  We do not refer to ia6t_expire and ia6t_preferred
  	 * to see if the address is deprecated or invalidated, but initialize
  	 * these members for applications.
  	 */
  	ia->ia6_lifetime = ifra->ifra_lifetime;
  	if (ia->ia6_lifetime.ia6t_vltime != ND6_INFINITE_LIFETIME) {
  		ia->ia6_lifetime.ia6t_expire =
  		    time_second + ia->ia6_lifetime.ia6t_vltime;
  	} else
  		ia->ia6_lifetime.ia6t_expire = 0;
  	if (ia->ia6_lifetime.ia6t_pltime != ND6_INFINITE_LIFETIME) {
  		ia->ia6_lifetime.ia6t_preferred =
  		    time_second + ia->ia6_lifetime.ia6t_pltime;
  	} else
  		ia->ia6_lifetime.ia6t_preferred = 0;
  
  	/* reset the interface and routing table appropriately. */
  	if ((error = in6_ifinit(ifp, ia, &ifra->ifra_addr, hostIsNew)) != 0)
  		goto unlink;
  
  	/*
  	 * configure address flags.
  	 */
  	ia->ia6_flags = ifra->ifra_flags;
  	/*
  	 * backward compatibility - if IN6_IFF_DEPRECATED is set from the
  	 * userland, make it deprecated.
  	 */
  	if ((ifra->ifra_flags & IN6_IFF_DEPRECATED) != 0) {
  		ia->ia6_lifetime.ia6t_pltime = 0;
  		ia->ia6_lifetime.ia6t_preferred = time_second;
  	}
  	/*
  	 * Make the address tentative before joining multicast addresses,
  	 * so that corresponding MLD responses would not have a tentative
  	 * source address.
  	 */
  	ia->ia6_flags &= ~IN6_IFF_DUPLICATED;	/* safety */
  	if (hostIsNew && in6if_do_dad(ifp)
  #if defined(MIP6) && NMIP > 0
  	    && !(ia->ia6_flags & IN6_IFF_HOME) /* XXX XXX XXX */
  #endif /* MIP6 && NMIP > 0 */
  		) 
  		ia->ia6_flags |= IN6_IFF_TENTATIVE;
  
  	/*
  	 * We are done if we have simply modified an existing address.
  	 */
  	if (!hostIsNew)
  		return (error);
  
  	/*
  	 * Beyond this point, we should call in6_purgeaddr upon an error,
  	 * not just go to unlink.
  	 */
  
  	/* Join necessary multicast groups */
  	in6m_sol = NULL;
  	if ((ifp->if_flags & IFF_MULTICAST) != 0) {
  		struct sockaddr_in6 mltaddr, mltmask;
  #ifndef SCOPEDROUTING
  		u_int32_t zoneid = 0;
  #endif
  		struct sockaddr_in6 llsol;
  
  		/* join solicited multicast addr for new host id */
  		bzero(&llsol, sizeof(llsol));
  		llsol.sin6_family = AF_INET6;
  		llsol.sin6_len = sizeof(struct sockaddr_in6);
  		llsol.sin6_addr.s6_addr32[0] = htonl(0xff020000);
  		llsol.sin6_addr.s6_addr32[1] = 0;
  		llsol.sin6_addr.s6_addr32[2] = htonl(1);
  		llsol.sin6_addr.s6_addr32[3] =
  		    ifra->ifra_addr.sin6_addr.s6_addr32[3];
  		llsol.sin6_addr.s6_addr8[12] = 0xff;
  		if (in6_addr2zoneid(ifp, &llsol.sin6_addr,
  		    &llsol.sin6_scope_id)) {
  			/* XXX: should not happen */
  			log(LOG_ERR, "in6_update_ifa: "
  			    "in6_addr2zoneid failed\n");
  			goto cleanup;
  		}
  		in6_embedscope(&llsol.sin6_addr, &llsol);
  		delay = 0;
  		if ((flags & IN6_IFAUPDATE_DADDELAY)) {
  			/*
  			 * We need a random delay for DAD on the address
  			 * being configured.  It also means delaying
  			 * transmission of the corresponding MLD report to
  			 * avoid report collision.
  			 * [draft-ietf-ipv6-rfc2462bis-02.txt]
  			 */
  			delay = arc4random() %
  			    (MAX_RTR_SOLICITATION_DELAY * hz);
  		}
  		imm = in6_joingroup(ifp, &llsol.sin6_addr, &error, delay);
  		if (!imm) {
  			nd6log((LOG_ERR, "in6_update_ifa: "
  			    "addmulti failed for %s on %s "
  			    "(errno=%d)\n",
  			    ip6_sprintf(&llsol.sin6_addr),
  			    if_name(ifp), error));
  			goto cleanup;
  		}
  		LIST_INSERT_HEAD(&ia->ia6_memberships,
  		    imm, i6mm_chain);
  		in6m_sol = imm->i6mm_maddr;
  
  		bzero(&mltmask, sizeof(mltmask));
  		mltmask.sin6_len = sizeof(struct sockaddr_in6);
  		mltmask.sin6_family = AF_INET6;
  		mltmask.sin6_addr = in6mask32;
  
  		/*
  		 * join link-local all-nodes address
  		 */
  		bzero(&mltaddr, sizeof(mltaddr));
  		mltaddr.sin6_len = sizeof(struct sockaddr_in6);
  		mltaddr.sin6_family = AF_INET6;
  		mltaddr.sin6_addr = in6addr_linklocal_allnodes;
  		if (in6_addr2zoneid(ifp, &mltaddr.sin6_addr,
  		    &mltaddr.sin6_scope_id)) {
  			goto cleanup; /* XXX: should not fail */
  		}
  		/* necessary to fake unicast routing table */
  		in6_embedscope(&mltaddr.sin6_addr, &mltaddr);
  		zoneid = mltaddr.sin6_scope_id;
  		mltaddr.sin6_scope_id = 0;
  
  		/*
  		 * XXX: do we really need this automatic routes?
  		 * We should probably reconsider this stuff.  Most applications
  		 * actually do not need the routes, since they usually specify
  		 * the outgoing interface.
  		 */
  #ifdef __FreeBSD__
  		rt = rtalloc1((struct sockaddr *)&mltaddr, 0, 0UL);
  #else
  		rt = rtalloc1((struct sockaddr *)&mltaddr, 0);
  #endif
  		if (rt) {
  			/*
  			 * 32bit came from "mltmask"
  			 * XXX: only works in !SCOPEDROUTING case.
  			 */
  			if (memcmp(&mltaddr.sin6_addr,
  			    &((struct sockaddr_in6 *)rt_key(rt))->sin6_addr,
  			    32 / 8)) {
  #if (defined(__FreeBSD__) && __FreeBSD_version >= 502010)
  				RTFREE_LOCKED(rt);
  #else
  				RTFREE(rt);
  #endif
  				rt = NULL;
  			}
  		}
  		if (!rt) {
  #if defined(__OpenBSD__) || defined(__NetBSD__)
  			struct rt_addrinfo info;
  
  			bzero(&info, sizeof(info));
  			info.rti_info[RTAX_DST] = (struct sockaddr *)&mltaddr;
  			info.rti_info[RTAX_GATEWAY] =
  			    (struct sockaddr *)&ia->ia_addr;
  			info.rti_info[RTAX_NETMASK] =
  			    (struct sockaddr *)&mltmask;
  			info.rti_info[RTAX_IFA] =
  			    (struct sockaddr *)&ia->ia_addr;
  			/* XXX: we need RTF_CLONING to fake nd6_rtrequest */
  			info.rti_flags = RTF_UP | RTF_CLONING;
  			error = rtrequest1(RTM_ADD, &info, NULL);
  #else
  			error = rtrequest(RTM_ADD, (struct sockaddr *)&mltaddr,
  			    (struct sockaddr *)&ia->ia_addr,
  			    (struct sockaddr *)&mltmask, RTF_UP | RTF_CLONING,
  			    (struct rtentry **)0);
  #endif
  			if (error)
  				goto cleanup;
  		} else {
  #if (defined(__FreeBSD__) && __FreeBSD_version >= 502010)
  			RTFREE_LOCKED(rt);
  #else
  			RTFREE(rt);
  #endif
  		}
  
  		imm = in6_joingroup(ifp, &mltaddr.sin6_addr, &error, 0);
  		if (!imm) {
  			nd6log((LOG_WARNING,
  			    "in6_update_ifa: addmulti failed for "
  			    "%s on %s (errno=%d)\n",
  			    ip6_sprintf(&mltaddr.sin6_addr),
  			    if_name(ifp), error));
  			goto cleanup;
  		}
  		LIST_INSERT_HEAD(&ia->ia6_memberships, imm, i6mm_chain);
  
  		/*
  		 * join node information group address
  		 */
  #ifdef __FreeBSD__
  #define hostnamelen	strlen(hostname)
  #endif
  		delay = 0;
  		if ((flags & IN6_IFAUPDATE_DADDELAY)) {
  			/*
  			 * The spec doesn't say anything about delay for this
  			 * group, but the same logic should apply.
  			 */
  			delay = arc4random() %
  			    (MAX_RTR_SOLICITATION_DELAY * hz);
  		}
  		if (in6_nigroup(ifp, hostname, hostnamelen, &mltaddr) == 0) {
  			imm = in6_joingroup(ifp, &mltaddr.sin6_addr, &error,
  			    delay); /* XXX jinmei */
  			if (!imm) {
  				nd6log((LOG_WARNING, "in6_update_ifa: "
  				    "addmulti failed for %s on %s "
  				    "(errno=%d)\n",
  				    ip6_sprintf(&mltaddr.sin6_addr),
  				    if_name(ifp), error));
  				/* XXX not very fatal, go on... */
  			} else {
  				LIST_INSERT_HEAD(&ia->ia6_memberships,
  				    imm, i6mm_chain);
  			}
  		}
  #ifdef __FreeBSD__
  #undef hostnamelen
  #endif
  
  		/*
  		 * join interface-local all-nodes address.
  		 * (ff01::1%ifN, and ff01::%ifN/32)
  		 */
  		mltaddr.sin6_addr = in6addr_nodelocal_allnodes;
  		if (in6_addr2zoneid(ifp, &mltaddr.sin6_addr,
  		    &mltaddr.sin6_scope_id)) {
  			goto cleanup; /* XXX: should not fail */
  		}
  		/* necessary to fake unicast routing table */
  		in6_embedscope(&mltaddr.sin6_addr, &mltaddr);
  		zoneid = mltaddr.sin6_scope_id;
  		mltaddr.sin6_scope_id = 0;
  
  		/* XXX: again, do we really need the route? */
  #ifdef __FreeBSD__
  		rt = rtalloc1((struct sockaddr *)&mltaddr, 0, 0UL);
  #else
  		rt = rtalloc1((struct sockaddr *)&mltaddr, 0);
  #endif
  		if (rt) {
  			/* 32bit came from "mltmask" */
  			if (memcmp(&mltaddr.sin6_addr,
  			    &((struct sockaddr_in6 *)rt_key(rt))->sin6_addr,
  			    32 / 8)) {
  #if (defined(__FreeBSD__) && __FreeBSD_version >= 502010)
  				RTFREE_LOCKED(rt);
  #else
  				RTFREE(rt);
  #endif
  				rt = NULL;
  			}
  		}
  		if (!rt) {
  #if defined(__OpenBSD__) || defined(__NetBSD__)
  			struct rt_addrinfo info;
  
  			bzero(&info, sizeof(info));
  			info.rti_info[RTAX_DST] = (struct sockaddr *)&mltaddr;
  			info.rti_info[RTAX_GATEWAY] =
  			    (struct sockaddr *)&ia->ia_addr;
  			info.rti_info[RTAX_NETMASK] =
  			    (struct sockaddr *)&mltmask;
  			info.rti_info[RTAX_IFA] =
  			    (struct sockaddr *)&ia->ia_addr;
  			info.rti_flags = RTF_UP | RTF_CLONING;
  			error = rtrequest1(RTM_ADD, &info, NULL);
  #else
  			error = rtrequest(RTM_ADD, (struct sockaddr *)&mltaddr,
  			    (struct sockaddr *)&ia->ia_addr,
  			    (struct sockaddr *)&mltmask, RTF_UP | RTF_CLONING,
  			    (struct rtentry **)0);
  #endif
  			if (error)
  				goto cleanup;
  		} else {
  #if (defined(__FreeBSD__) && __FreeBSD_version >= 502010)
  			RTFREE_LOCKED(rt);
  #else
  			RTFREE(rt);
  #endif
  		}
  
  		imm = in6_joingroup(ifp, &mltaddr.sin6_addr, &error, 0);
  		if (!imm) {
  			nd6log((LOG_WARNING, "in6_update_ifa: "
  			    "addmulti failed for %s on %s "
  			    "(errno=%d)\n",
  			    ip6_sprintf(&mltaddr.sin6_addr),
  			    if_name(ifp), error));
  			goto cleanup;
  		}
  		LIST_INSERT_HEAD(&ia->ia6_memberships, imm, i6mm_chain);
  	}
  
  	/*
  	 * Perform DAD, if needed.
  	 * XXX It may be of use, if we can administratively
  	 * disable DAD.
  	 */
  	if (hostIsNew && in6if_do_dad(ifp) &&
  	    ((ifra->ifra_flags & IN6_IFF_NODAD) == 0) &&
  	    (ia->ia6_flags & IN6_IFF_TENTATIVE))
  	{
  		int mindelay, maxdelay;
  
  		delay = 0;
  		if ((flags & IN6_IFAUPDATE_DADDELAY)) {
  			/*
  			 * We need to impose a delay before sending an NS
  			 * for DAD.  Check if we also needed a delay for the
  			 * corresponding MLD message.  If we did, the delay
  			 * should be larger than the MLD delay (this could be
  			 * relaxed a bit, but this simple logic is at least
  			 * safe).
  			 */
  			mindelay = 0;
  			if (in6m_sol != NULL &&
  			    in6m_sol->in6m_state == MLD_REPORTPENDING) {
  				mindelay = in6m_sol->in6m_timer;
  			}
  			maxdelay = MAX_RTR_SOLICITATION_DELAY * hz;
  			if (maxdelay - mindelay == 0)
  				delay = 0;
  			else {
  				delay =
  				    (arc4random() % (maxdelay - mindelay)) +
  				    mindelay;
  			}
  		}
  		nd6_dad_start((struct ifaddr *)ia, delay);
  	}
  
  	return (error);
  
    unlink:
  	/*
  	 * XXX: if a change of an existing address failed, keep the entry
  	 * anyway.
  	 */
  	if (hostIsNew)
  		in6_unlink_ifa(ia, ifp);
  	return (error);
  
    cleanup:
  	in6_purgeaddr(&ia->ia_ifa);
  	return error;
  }
  
  void
  in6_purgeaddr(ifa)
  	struct ifaddr *ifa;
  {
  	struct ifnet *ifp = ifa->ifa_ifp;
  	struct in6_ifaddr *ia = (struct in6_ifaddr *) ifa;
  	struct in6_multi_mship *imm;
  
  	/* stop DAD processing */
  	nd6_dad_stop(ifa);
  
  	/*
  	 * delete route to the destination of the address being purged.
  	 * The interface must be p2p or loopback in this case.
  	 */
  	if ((ia->ia_flags & IFA_ROUTE) != 0 && ia->ia_dstaddr.sin6_len != 0) {
  		int e;
  
  		if ((e = rtinit(&(ia->ia_ifa), (int)RTM_DELETE, RTF_HOST))
  		    != 0) {
  			log(LOG_ERR, "in6_purgeaddr: failed to remove "
  			    "a route to the p2p destination: %s on %s, "
  			    "errno=%d\n",
  			    ip6_sprintf(&ia->ia_addr.sin6_addr), if_name(ifp),
  			    e);
  			/* proceed anyway... */
  		} else
  			ia->ia_flags &= ~IFA_ROUTE;
  	}
  
  	/* Remove ownaddr's loopback rtentry, if it exists. */
  	in6_ifremloop(&(ia->ia_ifa));
  
  	/*
  	 * leave from multicast groups we have joined for the interface
  	 */
  	while ((imm = ia->ia6_memberships.lh_first) != NULL) {
  		LIST_REMOVE(imm, i6mm_chain);
  		in6_leavegroup(imm);
  	}
  
  #if defined(MIP6) && NMIP > 0
  	{
  		struct mip6_bul_internal *mbul;
  		while ((mbul = LIST_FIRST(&ia->ia6_mbul_list)) != NULL) {
  			mip6_bul_remove(mbul);
  		}
  	}
  #endif /* MIP6 && NMIP > 0 */
  
  	in6_unlink_ifa(ia, ifp);
  }
  
  static void
  in6_unlink_ifa(ia, ifp)
  	struct in6_ifaddr *ia;
  	struct ifnet *ifp;
  {
  	struct in6_ifaddr *oia;
  #if defined(__NetBSD__) || defined(__OpenBSD__)
  	int	s = splsoftnet();	/* XXX {Net,Open}BSD is splnet() */
  #else
  	int	s = splnet();
  #endif
  
  	TAILQ_REMOVE(&ifp->if_addrlist, &ia->ia_ifa, ifa_list);
  #ifdef __NetBSD__
  	/* release a refcnt for the link from if_addrlist */
  	IFAFREE(&ia->ia_ifa);
  #endif
  
  	oia = ia;
  	if (oia == (ia = in6_ifaddr))
  		in6_ifaddr = ia->ia_next;
  	else {
  		while (ia->ia_next && (ia->ia_next != oia))
  			ia = ia->ia_next;
  		if (ia->ia_next)
  			ia->ia_next = oia->ia_next;
  		else {
  			/* search failed */
  			printf("Couldn't unlink in6_ifaddr from in6_ifaddr\n");
  		}
  	}
  
  #ifndef __FreeBSD__
  	if (oia->ia6_multiaddrs.lh_first != NULL) {
  #ifdef __NetBSD__
  		/*
  		 * XXX thorpej@netbsd.org -- if the interface is going
  		 * XXX away, don't save the multicast entries, delete them!
  		 */
  		if (oia->ia_ifa.ifa_ifp->if_output == if_nulloutput) {
  			struct in6_multi *in6m;
  
  			while ((in6m =
  			    LIST_FIRST(&oia->ia6_multiaddrs)) != NULL) {
  				in6_delmulti(in6m);
  			}
  		} else
  			in6_savemkludge(oia);
  #else
  		in6_savemkludge(oia);
  #endif
  	}
  #endif
  
  	/*
  	 * Release the reference to the base prefix.  There should be a
  	 * positive reference.
  	 */
  	if (oia->ia6_ndpr == NULL) {
  		nd6log((LOG_NOTICE,
  		    "in6_unlink_ifa: autoconf'ed address "
  		    "%p has no prefix\n", oia));
  	} else {
  		oia->ia6_ndpr->ndpr_refcnt--;
  		oia->ia6_ndpr = NULL;
  	}
  
  	/*
  	 * Also, if the address being removed is autoconf'ed, call
  	 * pfxlist_onlink_check() since the release might affect the status of
  	 * other (detached) addresses. 
  	 */
  	if ((oia->ia6_flags & IN6_IFF_AUTOCONF))
  		pfxlist_onlink_check();
  
  	/*
  	 * release another refcnt for the link from in6_ifaddr.
  	 * Note that we should decrement the refcnt at least once for all *BSD.
  	 */
  	IFAFREE(&oia->ia_ifa);
  
  	splx(s);
  }
  
  void
  in6_purgeif(ifp)
  	struct ifnet *ifp;
  {
  	struct ifaddr *ifa, *nifa;
  
  	for (ifa = TAILQ_FIRST(&ifp->if_addrlist); ifa != NULL; ifa = nifa) {
  		nifa = TAILQ_NEXT(ifa, ifa_list);
  		if (ifa->ifa_addr->sa_family != AF_INET6)
  			continue;
  		in6_purgeaddr(ifa);
  	}
  
  	in6_ifdetach(ifp);
  }
  
  /*
   * SIOC[GAD]LIFADDR.
   *	SIOCGLIFADDR: get first address. (?)
   *	SIOCGLIFADDR with IFLR_PREFIX:
   *		get first address that matches the specified prefix.
   *	SIOCALIFADDR: add the specified address.
   *	SIOCALIFADDR with IFLR_PREFIX:
   *		add the specified prefix, filling hostid part from
   *		the first link-local address.  prefixlen must be <= 64.
   *	SIOCDLIFADDR: delete the specified address.
   *	SIOCDLIFADDR with IFLR_PREFIX:
   *		delete the first address that matches the specified prefix.
   * return values:
   *	EINVAL on invalid parameters
   *	EADDRNOTAVAIL on prefix match failed/specified address not found
   *	other values may be returned from in6_ioctl()
   *
   * NOTE: SIOCALIFADDR(with IFLR_PREFIX set) allows prefixlen less than 64.
   * this is to accomodate address naming scheme other than RFC2374,
   * in the future.
   * RFC2373 defines interface id to be 64bit, but it allows non-RFC2374
   * address encoding scheme. (see figure on page 8)
   */
  static int
  #if defined(__FreeBSD__) && __FreeBSD_version >= 500000
  in6_lifaddr_ioctl(so, cmd, data, ifp, p)
  	struct socket *so;
  	u_long cmd;
  	caddr_t	data;
  	struct ifnet *ifp;
  	struct thread *p;
  #else
  in6_lifaddr_ioctl(so, cmd, data, ifp, p)
  	struct socket *so;
  	u_long cmd;
  	caddr_t	data;
  	struct ifnet *ifp;
  	struct proc *p;
  #endif
  {
  	struct if_laddrreq *iflr = (struct if_laddrreq *)data;
  	struct ifaddr *ifa;
  	struct sockaddr *sa;
  
  	/* sanity checks */
  	if (!data || !ifp) {
  		panic("invalid argument to in6_lifaddr_ioctl");
  		/* NOTREACHED */
  	}
  
  	switch (cmd) {
  	case SIOCGLIFADDR:
  		/* address must be specified on GET with IFLR_PREFIX */
  		if ((iflr->flags & IFLR_PREFIX) == 0)
  			break;
  		/* FALLTHROUGH */
  	case SIOCALIFADDR:
  	case SIOCDLIFADDR:
  		/* address must be specified on ADD and DELETE */
  		sa = (struct sockaddr *)&iflr->addr;
  		if (sa->sa_family != AF_INET6)
  			return EINVAL;
  		if (sa->sa_len != sizeof(struct sockaddr_in6))
  			return EINVAL;
  		/* XXX need improvement */
  		sa = (struct sockaddr *)&iflr->dstaddr;
  		if (sa->sa_family && sa->sa_family != AF_INET6)
  			return EINVAL;
  		if (sa->sa_len && sa->sa_len != sizeof(struct sockaddr_in6))
  			return EINVAL;
  		break;
  	default: /* shouldn't happen */
  #if 0
  		panic("invalid cmd to in6_lifaddr_ioctl");
  		/* NOTREACHED */
  #else
  		return EOPNOTSUPP;
  #endif
  	}
  	if (sizeof(struct in6_addr) * 8 < iflr->prefixlen)
  		return EINVAL;
  
  	switch (cmd) {
  	case SIOCALIFADDR:
  	    {
  		struct in6_aliasreq ifra;
  		struct in6_addr *hostid = NULL;
  		int prefixlen;
  
  		if ((iflr->flags & IFLR_PREFIX) != 0) {
  			struct sockaddr_in6 *sin6;
  
  			/*
  			 * hostid is to fill in the hostid part of the
  			 * address.  hostid points to the first link-local
  			 * address attached to the interface.
  			 */
  			ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp, 0);
  			if (!ifa)
  				return EADDRNOTAVAIL;
  			hostid = IFA_IN6(ifa);
  
  		 	/* prefixlen must be <= 64. */
  			if (64 < iflr->prefixlen)
  				return EINVAL;
  			prefixlen = iflr->prefixlen;
  
  			/* hostid part must be zero. */
  			sin6 = (struct sockaddr_in6 *)&iflr->addr;
  			if (sin6->sin6_addr.s6_addr32[2] != 0 ||
  			    sin6->sin6_addr.s6_addr32[3] != 0) {
  				return EINVAL;
  			}
  		} else
  			prefixlen = iflr->prefixlen;
  
  		/* copy args to in6_aliasreq, perform ioctl(SIOCAIFADDR_IN6). */
  		bzero(&ifra, sizeof(ifra));
  		bcopy(iflr->iflr_name, ifra.ifra_name, sizeof(ifra.ifra_name));
  
  		bcopy(&iflr->addr, &ifra.ifra_addr,
  		    ((struct sockaddr *)&iflr->addr)->sa_len);
  		if (hostid) {
  			/* fill in hostid part */
  			ifra.ifra_addr.sin6_addr.s6_addr32[2] =
  			    hostid->s6_addr32[2];
  			ifra.ifra_addr.sin6_addr.s6_addr32[3] =
  			    hostid->s6_addr32[3];
  		}
  
  		if (((struct sockaddr *)&iflr->dstaddr)->sa_family) { /* XXX */
  			bcopy(&iflr->dstaddr, &ifra.ifra_dstaddr,
  			    ((struct sockaddr *)&iflr->dstaddr)->sa_len);
  			if (hostid) {
  				ifra.ifra_dstaddr.sin6_addr.s6_addr32[2] =
  				    hostid->s6_addr32[2];
  				ifra.ifra_dstaddr.sin6_addr.s6_addr32[3] =
  				    hostid->s6_addr32[3];
  			}
  		}
  
  		ifra.ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6);
  		in6_prefixlen2mask(&ifra.ifra_prefixmask.sin6_addr, prefixlen);
  
  		ifra.ifra_flags = iflr->flags & ~IFLR_PREFIX;
  		return in6_control(so, SIOCAIFADDR_IN6, (caddr_t)&ifra, ifp, p);
  	    }
  	case SIOCGLIFADDR:
  	case SIOCDLIFADDR:
  	    {
  		struct in6_ifaddr *ia;
  		struct in6_addr mask, candidate, match;
  		struct sockaddr_in6 *sin6;
  		int cmp;
  
  		bzero(&mask, sizeof(mask));
  		if (iflr->flags & IFLR_PREFIX) {
  			/* lookup a prefix rather than address. */
  			in6_prefixlen2mask(&mask, iflr->prefixlen);
  
  			sin6 = (struct sockaddr_in6 *)&iflr->addr;
  			bcopy(&sin6->sin6_addr, &match, sizeof(match));
  			match.s6_addr32[0] &= mask.s6_addr32[0];
  			match.s6_addr32[1] &= mask.s6_addr32[1];
  			match.s6_addr32[2] &= mask.s6_addr32[2];
  			match.s6_addr32[3] &= mask.s6_addr32[3];
  
  			/* if you set extra bits, that's wrong */
  			if (bcmp(&match, &sin6->sin6_addr, sizeof(match)))
  				return EINVAL;
  
  			cmp = 1;
  		} else {
  			if (cmd == SIOCGLIFADDR) {
  				/* on getting an address, take the 1st match */
  				cmp = 0;	/* XXX */
  			} else {
  				/* on deleting an address, do exact match */
  				in6_prefixlen2mask(&mask, 128);
  				sin6 = (struct sockaddr_in6 *)&iflr->addr;
  				bcopy(&sin6->sin6_addr, &match, sizeof(match));
  
  				cmp = 1;
  			}
  		}
  
  #ifdef __FreeBSD__
  		TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list)
  #else
  		for (ifa = ifp->if_addrlist.tqh_first;
  		     ifa;
  		     ifa = ifa->ifa_list.tqe_next)
  #endif
  		{
  			if (ifa->ifa_addr->sa_family != AF_INET6)
  				continue;
  			if (!cmp)
  				break;
  
  			bcopy(IFA_IN6(ifa), &candidate, sizeof(candidate));
  #ifndef SCOPEDROUTING
  			/*
  			 * XXX: this is adhoc, but is necessary to allow
  			 * a user to specify fe80::/64 (not /10) for a
  			 * link-local address.
  			 */
  			if (IN6_IS_ADDR_LINKLOCAL(&candidate))
  				candidate.s6_addr16[1] = 0;
  #endif
  			candidate.s6_addr32[0] &= mask.s6_addr32[0];
  			candidate.s6_addr32[1] &= mask.s6_addr32[1];
  			candidate.s6_addr32[2] &= mask.s6_addr32[2];
  			candidate.s6_addr32[3] &= mask.s6_addr32[3];
  			if (IN6_ARE_ADDR_EQUAL(&candidate, &match))
  				break;
  		}
  		if (!ifa)
  			return EADDRNOTAVAIL;
  		ia = ifa2ia6(ifa);
  
  		if (cmd == SIOCGLIFADDR) {
  #ifndef SCOPEDROUTING
  			struct sockaddr_in6 *s6;
  #endif
  
  			/* fill in the if_laddrreq structure */
  			bcopy(&ia->ia_addr, &iflr->addr, ia->ia_addr.sin6_len);
  #ifndef SCOPEDROUTING		/* XXX see above */
  			s6 = (struct sockaddr_in6 *)&iflr->addr;
  			if (IN6_IS_ADDR_LINKLOCAL(&s6->sin6_addr)) {
  				s6->sin6_addr.s6_addr16[1] = 0;
  				if (in6_addr2zoneid(ifp, &s6->sin6_addr,
  				    &s6->sin6_scope_id))
  					return (EINVAL);	/* XXX */
  			}
  #endif
  			if ((ifp->if_flags & IFF_POINTOPOINT) != 0) {
  				bcopy(&ia->ia_dstaddr, &iflr->dstaddr,
  				    ia->ia_dstaddr.sin6_len);
  #ifndef SCOPEDROUTING		/* XXX see above */
  				s6 = (struct sockaddr_in6 *)&iflr->dstaddr;
  				if (IN6_IS_ADDR_LINKLOCAL(&s6->sin6_addr)) {
  					s6->sin6_addr.s6_addr16[1] = 0;
  					if (in6_addr2zoneid(ifp,
  					    &s6->sin6_addr, &s6->sin6_scope_id))
  						return (EINVAL); /* EINVAL */
  				}
  #endif
  			} else
  				bzero(&iflr->dstaddr, sizeof(iflr->dstaddr));
  
  			iflr->prefixlen =
  			    in6_mask2len(&ia->ia_prefixmask.sin6_addr, NULL);
  
  			iflr->flags = ia->ia6_flags;	/* XXX */
  
  			return 0;
  		} else {
  			struct in6_aliasreq ifra;
  
  			/* fill in6_aliasreq and do ioctl(SIOCDIFADDR_IN6) */
  			bzero(&ifra, sizeof(ifra));
  			bcopy(iflr->iflr_name, ifra.ifra_name,
  			    sizeof(ifra.ifra_name));
  
  			bcopy(&ia->ia_addr, &ifra.ifra_addr,
  			    ia->ia_addr.sin6_len);
  			if ((ifp->if_flags & IFF_POINTOPOINT) != 0) {
  				bcopy(&ia->ia_dstaddr, &ifra.ifra_dstaddr,
  				    ia->ia_dstaddr.sin6_len);
  			} else {
  				bzero(&ifra.ifra_dstaddr,
  				    sizeof(ifra.ifra_dstaddr));
  			}
  			bcopy(&ia->ia_prefixmask, &ifra.ifra_dstaddr,
  			    ia->ia_prefixmask.sin6_len);
  
  			ifra.ifra_flags = ia->ia6_flags;
  			return in6_control(so, SIOCDIFADDR_IN6, (caddr_t)&ifra,
  			    ifp, p);
  		}
  	    }
  	}
  
  	return EOPNOTSUPP;	/* just for safety */
  }
  
  /*
   * Initialize an interface's intetnet6 address
   * and routing table entry.
   */
  static int
  in6_ifinit(ifp, ia, sin6, newhost)
  	struct ifnet *ifp;
  	struct in6_ifaddr *ia;
  	struct sockaddr_in6 *sin6;
  	int newhost;
  {
  	int	error = 0, plen, ifacount = 0;
  #ifdef __NetBSD__
  	int	s = splnet();
  #else
  	int	s = splimp();
  #endif
  	struct ifaddr *ifa;
  
  	/*
  	 * Give the interface a chance to initialize
  	 * if this is its first address,
  	 * and to validate the address if necessary.
  	 */
  #ifdef __FreeBSD__
  	TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list)
  #else
  	for (ifa = ifp->if_addrlist.tqh_first; ifa;
  	     ifa = ifa->ifa_list.tqe_next)
  #endif
  	{
  		if (ifa->ifa_addr == NULL)
  			continue;	/* just for safety */
  		if (ifa->ifa_addr->sa_family != AF_INET6)
  			continue;
  		ifacount++;
  	}
  
  	ia->ia_addr = *sin6;
  
  	if (ifacount <= 1 && ifp->if_ioctl &&
  	    (error = (*ifp->if_ioctl)(ifp, SIOCSIFADDR, (caddr_t)ia))) {
  		splx(s);
  		return (error);
  	}
  	splx(s);
  
  	ia->ia_ifa.ifa_metric = ifp->if_metric;
  
  	/* we could do in(6)_socktrim here, but just omit it at this moment. */
  
  	/*
  	 * Special case:
  	 * If a new destination address is specified for a point-to-point
  	 * interface, install a route to the destination as an interface
  	 * direct route.
  	 * XXX: the logic below rejects assigning multiple addresses on a p2p
  	 * interface that share a same destination.
  	 */
  	plen = in6_mask2len(&ia->ia_prefixmask.sin6_addr, NULL); /* XXX */
  	if (!(ia->ia_flags & IFA_ROUTE) && plen == 128 &&
  	    ia->ia_dstaddr.sin6_family == AF_INET6) {
  		if ((error = rtinit(&(ia->ia_ifa), (int)RTM_ADD,
  				    RTF_UP | RTF_HOST)) != 0)
  			return (error);
  		ia->ia_flags |= IFA_ROUTE;
  	}
  
  	/* Add ownaddr as loopback rtentry, if necessary (ex. on p2p link). */
  	if (newhost) {
  		/* set the rtrequest function to create llinfo */
  		ia->ia_ifa.ifa_rtrequest = nd6_rtrequest;
  		in6_ifaddloop(&(ia->ia_ifa));
  	}
  
  #ifndef __FreeBSD__
  	if (ifp->if_flags & IFF_MULTICAST)
  		in6_restoremkludge(ia, ifp);
  #endif
  
  	return (error);
  }
  
  
  /*
   * Find an IPv6 interface link-local address specific to an interface.
   */
  struct in6_ifaddr *
  in6ifa_ifpforlinklocal(ifp, ignoreflags)
  	struct ifnet *ifp;
  	int ignoreflags;
  {
  	struct ifaddr *ifa;
  
  #ifdef __FreeBSD__
  	TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list)
  #else
  	for (ifa = ifp->if_addrlist.tqh_first; ifa; ifa = ifa->ifa_list.tqe_next)
  #endif
  	{
  		if (ifa->ifa_addr == NULL)
  			continue;	/* just for safety */
  		if (ifa->ifa_addr->sa_family != AF_INET6)
  			continue;
  		if (IN6_IS_ADDR_LINKLOCAL(IFA_IN6(ifa))) {
  			if ((((struct in6_ifaddr *)ifa)->ia6_flags &
  			     ignoreflags) != 0)
  				continue;
  			break;
  		}
  	}
  
  	return ((struct in6_ifaddr *)ifa);
  }
  
  
  /*
   * find the internet address corresponding to a given interface and address.
   */
  struct in6_ifaddr *
  in6ifa_ifpwithaddr(ifp, addr)
  	struct ifnet *ifp;
  	struct in6_addr *addr;
  {
  	struct ifaddr *ifa;
  
  #ifdef __FreeBSD__
  	TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list)
  #else
  	for (ifa = ifp->if_addrlist.tqh_first; ifa; ifa = ifa->ifa_list.tqe_next)
  #endif
  	{
  		if (ifa->ifa_addr == NULL)
  			continue;	/* just for safety */
  		if (ifa->ifa_addr->sa_family != AF_INET6)
  			continue;
  		if (IN6_ARE_ADDR_EQUAL(addr, IFA_IN6(ifa)))
  			break;
  	}
  
  	return ((struct in6_ifaddr *)ifa);
  }
  
  /*
   * Convert IP6 address to printable (loggable) representation.
   */
  static char digits[] = "0123456789abcdef";
  static int ip6round = 0;
  char *
  ip6_sprintf(addr)
  	const struct in6_addr *addr;
  {
  	static char ip6buf[8][48];
  	int i;
  	char *cp;
  	const u_int16_t *a = (const u_int16_t *)addr;
  	const u_int8_t *d;
  	int dcolon = 0;
  
  	ip6round = (ip6round + 1) & 7;
  	cp = ip6buf[ip6round];
  
  	for (i = 0; i < 8; i++) {
  		if (dcolon == 1) {
  			if (*a == 0) {
  				if (i == 7)
  					*cp++ = ':';
  				a++;
  				continue;
  			} else
  				dcolon = 2;
  		}
  		if (*a == 0) {
  			if (dcolon == 0 && *(a + 1) == 0) {
  				if (i == 0)
  					*cp++ = ':';
  				*cp++ = ':';
  				dcolon = 1;
  			} else {
  				*cp++ = '0';
  				*cp++ = ':';
  			}
  			a++;
  			continue;
  		}
  		d = (const u_char *)a;
  		*cp++ = digits[*d >> 4];
  		*cp++ = digits[*d++ & 0xf];
  		*cp++ = digits[*d >> 4];
  		*cp++ = digits[*d & 0xf];
  		*cp++ = ':';
  		a++;
  	}
  	*--cp = 0;
  	return (ip6buf[ip6round]);
  }
  
  #if defined(__FreeBSD__)
  int
  in6_localaddr(in6)
  	struct in6_addr *in6;
  {
  	struct in6_ifaddr *ia;
  
  	if (IN6_IS_ADDR_LOOPBACK(in6) || IN6_IS_ADDR_LINKLOCAL(in6)) {
  		return 1;
  	}
  
  	for (ia = in6_ifaddr; ia; ia = ia->ia_next) {
  		if (IN6_ARE_MASKED_ADDR_EQUAL(in6, &ia->ia_addr.sin6_addr,
  		    &ia->ia_prefixmask.sin6_addr)) {
  			return 1;
  		}
  	}
  
  	return (0);
  }
  #endif
  
  /*
   * return length of part which dst and src are equal
   * hard coding...
   */
  int
  in6_matchlen(src, dst)
  struct in6_addr *src, *dst;
  {
  	int match = 0;
  	u_char *s = (u_char *)src, *d = (u_char *)dst;
  	u_char *lim = s + 16, r;
  
  	while (s < lim)
  		if ((r = (*d++ ^ *s++)) != 0) {
  			while (r < 128) {
  				match++;
  				r <<= 1;
  			}
  			break;
  		} else
  			match += 8;
  	return match;
  }
  
  /* XXX: to be scope conscious */
  int
  in6_are_prefix_equal(p1, p2, len)
  	struct in6_addr *p1, *p2;
  	int len;
  {
  	int bytelen, bitlen;
  
  	/* sanity check */
  	if (0 > len || len > 128) {
  		log(LOG_ERR, "in6_are_prefix_equal: invalid prefix length(%d)\n",
  		    len);
  		return (0);
  	}
  
  	bytelen = len / 8;
  	bitlen = len % 8;
  
  	if (bcmp(&p1->s6_addr, &p2->s6_addr, bytelen))
  		return (0);
  	if (bitlen != 0 &&
  	    p1->s6_addr[bytelen] >> (8 - bitlen) !=
  	    p2->s6_addr[bytelen] >> (8 - bitlen))
  		return (0);
  
  	return (1);
  }
  
  void
  in6_prefixlen2mask(maskp, len)
  	struct in6_addr *maskp;
  	int len;
  {
  	u_char maskarray[8] = {0x80, 0xc0, 0xe0, 0xf0, 0xf8, 0xfc, 0xfe, 0xff};
  	int bytelen, bitlen, i;
  
  	/* sanity check */
  	if (0 > len || len > 128) {
  		log(LOG_ERR, "in6_prefixlen2mask: invalid prefix length(%d)\n",
  		    len);
  		return;
  	}
  
  	bzero(maskp, sizeof(*maskp));
  	bytelen = len / 8;
  	bitlen = len % 8;
  	for (i = 0; i < bytelen; i++)
  		maskp->s6_addr[i] = 0xff;
  	if (bitlen)
  		maskp->s6_addr[bytelen] = maskarray[bitlen - 1];
  }
  
  /*
   * return the best address out of the same scope. if no address was
   * found, return the first valid address from designated IF.
   */
  struct in6_ifaddr *
  in6_ifawithifp(ifp, dst)
  	struct ifnet *ifp;
  	struct in6_addr *dst;
  {
  	int dst_scope =	in6_addrscope(dst), blen = -1, tlen;
  	struct ifaddr *ifa;
  	struct in6_ifaddr *besta = 0;
  	struct in6_ifaddr *dep[2];	/* last-resort: deprecated */
  
  	dep[0] = dep[1] = NULL;
  
  	/*
  	 * We first look for addresses in the same scope.
  	 * If there is one, return it.
  	 * If two or more, return one which matches the dst longest.
  	 * If none, return one of global addresses assigned other ifs.
  	 */
  #ifdef __FreeBSD__
  	TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list)
  #else
  	for (ifa = ifp->if_addrlist.tqh_first; ifa; ifa = ifa->ifa_list.tqe_next)
  #endif
  	{
  		if (ifa->ifa_addr->sa_family != AF_INET6)
  			continue;
  		if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST)
  			continue; /* XXX: is there any case to allow anycast? */
  		if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_NOTREADY)
  			continue; /* don't use this interface */
  		if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DETACHED)
  			continue;
  		if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DEPRECATED) {
  			if (ip6_use_deprecated)
  				dep[0] = (struct in6_ifaddr *)ifa;
  			continue;
  		}
  
  		if (dst_scope == in6_addrscope(IFA_IN6(ifa))) {
  			/*
  			 * call in6_matchlen() as few as possible
  			 */
  			if (besta) {
  				if (blen == -1)
  					blen = in6_matchlen(&besta->ia_addr.sin6_addr, dst);
  				tlen = in6_matchlen(IFA_IN6(ifa), dst);
  				if (tlen > blen) {
  					blen = tlen;
  					besta = (struct in6_ifaddr *)ifa;
  				}
  			} else
  				besta = (struct in6_ifaddr *)ifa;
  		}
  	}
  	if (besta)
  		return (besta);
  
  #ifdef __FreeBSD__
  	TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list)
  #else
  	for (ifa = ifp->if_addrlist.tqh_first; ifa; ifa = ifa->ifa_list.tqe_next)
  #endif
  	{
  		if (ifa->ifa_addr->sa_family != AF_INET6)
  			continue;
  		if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST)
  			continue; /* XXX: is there any case to allow anycast? */
  		if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_NOTREADY)
  			continue; /* don't use this interface */
  		if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DETACHED)
  			continue;
  		if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DEPRECATED) {
  			if (ip6_use_deprecated)
  				dep[1] = (struct in6_ifaddr *)ifa;
  			continue;
  		}
  
  		return (struct in6_ifaddr *)ifa;
  	}
  
  	/* use the last-resort values, that are, deprecated addresses */
  	if (dep[0])
  		return dep[0];
  	if (dep[1])
  		return dep[1];
  
  	return NULL;
  }
  
  /*
   * perform DAD when interface becomes IFF_UP.
   */
  void
  in6_if_up(ifp)
  	struct ifnet *ifp;
  {
  	struct ifaddr *ifa;
  	struct in6_ifaddr *ia;
  
  #ifdef __FreeBSD__
  	TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list)
  #else
  	for (ifa = ifp->if_addrlist.tqh_first; ifa;
  	    ifa = ifa->ifa_list.tqe_next)
  #endif
  	{
  		if (ifa->ifa_addr->sa_family != AF_INET6)
  			continue;
  		ia = (struct in6_ifaddr *)ifa;
  		if (ia->ia6_flags & IN6_IFF_TENTATIVE) {
  			nd6_dad_start(ifa,
  			    arc4random() % (MAX_RTR_SOLICITATION_DELAY * hz));
  		}
  	}
  
  	/*
  	 * special cases, like 6to4, are handled in in6_ifattach
  	 */
  	in6_ifattach(ifp, NULL);
  }
  
  int
  in6if_do_dad(ifp)
  	struct ifnet *ifp;
  {
  	if ((ifp->if_flags & IFF_LOOPBACK) != 0)
  		return (0);
  
  	switch (ifp->if_type) {
  #ifdef IFT_DUMMY
  	case IFT_DUMMY:
  #endif
  	case IFT_FAITH:
  		/*
  		 * These interfaces do not have the IFF_LOOPBACK flag,
  		 * but loop packets back.  We do not have to do DAD on such
  		 * interfaces.  We should even omit it, because loop-backed
  		 * NS would confuse the DAD procedure.
  		 */
  		return (0);
  	default:
  		/*
  		 * Our DAD routine requires the interface up and running.
  		 * However, some interfaces can be up before the RUNNING
  		 * status.  Additionaly, users may try to assign addresses
  		 * before the interface becomes up (or running).
  		 * We simply skip DAD in such a case as a work around.
  		 * XXX: we should rather mark "tentative" on such addresses,
  		 * and do DAD after the interface becomes ready.
  		 */
  		if ((ifp->if_flags & (IFF_UP|IFF_RUNNING)) !=
  		    (IFF_UP|IFF_RUNNING))
  			return (0);
  
  		return (1);
  	}
  }
  
  /*
   * Calculate max IPv6 MTU through all the interfaces and store it
   * to in6_maxmtu.
   */
  void
  in6_setmaxmtu()
  {
  	unsigned long maxmtu = 0;
  	struct ifnet *ifp;
  
  	for (ifp = TAILQ_FIRST(&ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list)) {
  		/* this function can be called during ifnet initialization */
  		if (!ifp->if_afdata[AF_INET6])
  			continue;
  		if ((ifp->if_flags & IFF_LOOPBACK) == 0 &&
  		    IN6_LINKMTU(ifp) > maxmtu)
  			maxmtu = IN6_LINKMTU(ifp);
  	}
  	if (maxmtu)	     /* update only when maxmtu is positive */
  		in6_maxmtu = maxmtu;
  }
  
  /*
   * Provide the length of interface identifiers to be used for the link attached
   * to the given interface.  The length should be defined in "IPv6 over
   * xxx-link" document.  Note that address architecture might also define
   * the length for a particular set of address prefixes, regardless of the
   * link type.  As clarified in rfc2462bis, those two definitions should be
   * consistent, and those really are as of August 2004.
   */
  int
  in6_if2idlen(ifp)
  	struct ifnet *ifp;
  {
  	switch (ifp->if_type) {
  	case IFT_ETHER:		/* RFC2464 */
  #ifdef IFT_PROPVIRTUAL
  	case IFT_PROPVIRTUAL:	/* XXX: no RFC. treat it as ether */
  #endif
  #ifdef IFT_L2VLAN
  	case IFT_L2VLAN:	/* ditto */
  #endif
  #ifdef IFT_IEEE80211
  	case IFT_IEEE80211:	/* ditto */
  #endif
  		return (64);
  	case IFT_FDDI:		/* RFC2467 */
  		return (64);
  	case IFT_ISO88025:	/* RFC2470 (IPv6 over Token Ring) */
  		return (64);
  	case IFT_ARCNET:	/* RFC2497 */
  		return (64);
  	case IFT_FRELAY:	/* RFC2590 */
  		return (64);
  	case IFT_IEEE1394:	/* RFC3146 */
  		return (64);
  	case IFT_GIF:
  		return (64);	/* draft-ietf-v6ops-mech-v2-05 */
  	case IFT_LOOP:
  		return (64);	/* XXX: is this really correct? */
  	default:
  		return (-1);	/* unknown link type */
  	}
  }
  
  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);
  }
  
  #ifdef __FreeBSD__
  /*
   * Convert sockaddr_in6 to sockaddr_in.  Original sockaddr_in6 must be
   * v4 mapped addr or v4 compat addr
   */
  void
  in6_sin6_2_sin(struct sockaddr_in *sin, struct sockaddr_in6 *sin6)
  {
  	bzero(sin, sizeof(*sin));
  	sin->sin_len = sizeof(struct sockaddr_in);
  	sin->sin_family = AF_INET;
  	sin->sin_port = sin6->sin6_port;
  	sin->sin_addr.s_addr = sin6->sin6_addr.s6_addr32[3];
  }
  
  /* Convert sockaddr_in to sockaddr_in6 in v4 mapped addr format. */
  void
  in6_sin_2_v4mapsin6(struct sockaddr_in *sin, struct sockaddr_in6 *sin6)
  {
  	bzero(sin6, sizeof(*sin6));
  	sin6->sin6_len = sizeof(struct sockaddr_in6);
  	sin6->sin6_family = AF_INET6;
  	sin6->sin6_port = sin->sin_port;
  	sin6->sin6_addr.s6_addr32[0] = 0;
  	sin6->sin6_addr.s6_addr32[1] = 0;
  	sin6->sin6_addr.s6_addr32[2] = IPV6_ADDR_INT32_SMP;
  	sin6->sin6_addr.s6_addr32[3] = sin->sin_addr.s_addr;
  }
  
  /* Convert sockaddr_in6 into sockaddr_in. */
  void
  in6_sin6_2_sin_in_sock(struct sockaddr *nam)
  {
  	struct sockaddr_in *sin_p;
  	struct sockaddr_in6 sin6;
  
  	/*
  	 * Save original sockaddr_in6 addr and convert it
  	 * to sockaddr_in.
  	 */
  	sin6 = *(struct sockaddr_in6 *)nam;
  	sin_p = (struct sockaddr_in *)nam;
  	in6_sin6_2_sin(sin_p, &sin6);
  }
  
  /* Convert sockaddr_in into sockaddr_in6 in v4 mapped addr format. */
  void
  in6_sin_2_v4mapsin6_in_sock(struct sockaddr **nam)
  {
  	struct sockaddr_in *sin_p;
  	struct sockaddr_in6 *sin6_p;
  
  	MALLOC(sin6_p, struct sockaddr_in6 *, sizeof *sin6_p, M_SONAME,
  	       M_WAITOK);
  	sin_p = (struct sockaddr_in *)*nam;
  	in6_sin_2_v4mapsin6(sin_p, sin6_p);
  	FREE(*nam, M_SONAME);
  	*nam = (struct sockaddr *)sin6_p;
  }
  #endif
  