xref: /freebsd/sys/netinet6/in6.c (revision 3a31b7eb32ad60e1e05b2b2e184ff47e4afbb874)
1 /*	$FreeBSD$	*/
2 /*	$KAME: in6.c,v 1.187 2001/05/24 07:43:59 itojun Exp $	*/
3 
4 /*
5  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the project nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 /*
34  * Copyright (c) 1982, 1986, 1991, 1993
35  *	The Regents of the University of California.  All rights reserved.
36  *
37  * Redistribution and use in source and binary forms, with or without
38  * modification, are permitted provided that the following conditions
39  * are met:
40  * 1. Redistributions of source code must retain the above copyright
41  *    notice, this list of conditions and the following disclaimer.
42  * 2. Redistributions in binary form must reproduce the above copyright
43  *    notice, this list of conditions and the following disclaimer in the
44  *    documentation and/or other materials provided with the distribution.
45  * 3. All advertising materials mentioning features or use of this software
46  *    must display the following acknowledgement:
47  *	This product includes software developed by the University of
48  *	California, Berkeley and its contributors.
49  * 4. Neither the name of the University nor the names of its contributors
50  *    may be used to endorse or promote products derived from this software
51  *    without specific prior written permission.
52  *
53  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
54  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
55  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
56  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
57  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
58  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
59  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
60  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
61  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
62  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
63  * SUCH DAMAGE.
64  *
65  *	@(#)in.c	8.2 (Berkeley) 11/15/93
66  */
67 
68 #include "opt_inet.h"
69 #include "opt_inet6.h"
70 
71 #include <sys/param.h>
72 #include <sys/errno.h>
73 #include <sys/malloc.h>
74 #include <sys/socket.h>
75 #include <sys/socketvar.h>
76 #include <sys/sockio.h>
77 #include <sys/systm.h>
78 #include <sys/proc.h>
79 #include <sys/time.h>
80 #include <sys/kernel.h>
81 #include <sys/syslog.h>
82 
83 #include <net/if.h>
84 #include <net/if_types.h>
85 #include <net/route.h>
86 #include <net/if_dl.h>
87 
88 #include <netinet/in.h>
89 #include <netinet/in_var.h>
90 #include <netinet/if_ether.h>
91 #ifndef SCOPEDROUTING
92 #include <netinet/in_systm.h>
93 #include <netinet/ip.h>
94 #include <netinet/in_pcb.h>
95 #endif
96 
97 #include <netinet6/nd6.h>
98 #include <netinet/ip6.h>
99 #include <netinet6/ip6_var.h>
100 #include <netinet6/mld6_var.h>
101 #include <netinet6/ip6_mroute.h>
102 #include <netinet6/in6_ifattach.h>
103 #include <netinet6/scope6_var.h>
104 #ifndef SCOPEDROUTING
105 #include <netinet6/in6_pcb.h>
106 #endif
107 
108 #include <net/net_osdep.h>
109 
110 MALLOC_DEFINE(M_IPMADDR, "in6_multi", "internet multicast address");
111 
112 /*
113  * Definitions of some costant IP6 addresses.
114  */
115 const struct in6_addr in6addr_any = IN6ADDR_ANY_INIT;
116 const struct in6_addr in6addr_loopback = IN6ADDR_LOOPBACK_INIT;
117 const struct in6_addr in6addr_nodelocal_allnodes =
118 	IN6ADDR_NODELOCAL_ALLNODES_INIT;
119 const struct in6_addr in6addr_linklocal_allnodes =
120 	IN6ADDR_LINKLOCAL_ALLNODES_INIT;
121 const struct in6_addr in6addr_linklocal_allrouters =
122 	IN6ADDR_LINKLOCAL_ALLROUTERS_INIT;
123 
124 const struct in6_addr in6mask0 = IN6MASK0;
125 const struct in6_addr in6mask32 = IN6MASK32;
126 const struct in6_addr in6mask64 = IN6MASK64;
127 const struct in6_addr in6mask96 = IN6MASK96;
128 const struct in6_addr in6mask128 = IN6MASK128;
129 
130 const struct sockaddr_in6 sa6_any = {sizeof(sa6_any), AF_INET6,
131 				     0, 0, IN6ADDR_ANY_INIT, 0};
132 
133 static int in6_lifaddr_ioctl __P((struct socket *, u_long, caddr_t,
134 	struct ifnet *, struct thread *));
135 static int in6_ifinit __P((struct ifnet *, struct in6_ifaddr *,
136 			   struct sockaddr_in6 *, int));
137 static void in6_unlink_ifa __P((struct in6_ifaddr *, struct ifnet *));
138 
139 struct in6_multihead in6_multihead;	/* XXX BSS initialization */
140 
141 int	(*faithprefix_p)(struct in6_addr *);
142 
143 /*
144  * Subroutine for in6_ifaddloop() and in6_ifremloop().
145  * This routine does actual work.
146  */
147 static void
148 in6_ifloop_request(int cmd, struct ifaddr *ifa)
149 {
150 	struct sockaddr_in6 all1_sa;
151 	struct rtentry *nrt = NULL;
152 	int e;
153 
154 	bzero(&all1_sa, sizeof(all1_sa));
155 	all1_sa.sin6_family = AF_INET6;
156 	all1_sa.sin6_len = sizeof(struct sockaddr_in6);
157 	all1_sa.sin6_addr = in6mask128;
158 
159 	/*
160 	 * We specify the address itself as the gateway, and set the
161 	 * RTF_LLINFO flag, so that the corresponding host route would have
162 	 * the flag, and thus applications that assume traditional behavior
163 	 * would be happy.  Note that we assume the caller of the function
164 	 * (probably implicitly) set nd6_rtrequest() to ifa->ifa_rtrequest,
165 	 * which changes the outgoing interface to the loopback interface.
166 	 */
167 	e = rtrequest(cmd, ifa->ifa_addr, ifa->ifa_addr,
168 		      (struct sockaddr *)&all1_sa,
169 		      RTF_UP|RTF_HOST|RTF_LLINFO, &nrt);
170 	if (e != 0) {
171 		log(LOG_ERR, "in6_ifloop_request: "
172 		    "%s operation failed for %s (errno=%d)\n",
173 		    cmd == RTM_ADD ? "ADD" : "DELETE",
174 		    ip6_sprintf(&((struct in6_ifaddr *)ifa)->ia_addr.sin6_addr),
175 		    e);
176 	}
177 
178 	/*
179 	 * Make sure rt_ifa be equal to IFA, the second argument of the
180 	 * function.
181 	 * We need this because when we refer to rt_ifa->ia6_flags in
182 	 * ip6_input, we assume that the rt_ifa points to the address instead
183 	 * of the loopback address.
184 	 */
185 	if (cmd == RTM_ADD && nrt && ifa != nrt->rt_ifa) {
186 		IFAFREE(nrt->rt_ifa);
187 		IFAREF(ifa);
188 		nrt->rt_ifa = ifa;
189 	}
190 
191 	/*
192 	 * Report the addition/removal of the address to the routing socket.
193 	 * XXX: since we called rtinit for a p2p interface with a destination,
194 	 *      we end up reporting twice in such a case.  Should we rather
195 	 *      omit the second report?
196 	 */
197 	if (nrt) {
198 		rt_newaddrmsg(cmd, ifa, e, nrt);
199 		if (cmd == RTM_DELETE) {
200 			if (nrt->rt_refcnt <= 0) {
201 				/* XXX: we should free the entry ourselves. */
202 				nrt->rt_refcnt++;
203 				rtfree(nrt);
204 			}
205 		} else {
206 			/* the cmd must be RTM_ADD here */
207 			nrt->rt_refcnt--;
208 		}
209 	}
210 }
211 
212 /*
213  * Add ownaddr as loopback rtentry.  We previously add the route only if
214  * necessary (ex. on a p2p link).  However, since we now manage addresses
215  * separately from prefixes, we should always add the route.  We can't
216  * rely on the cloning mechanism from the corresponding interface route
217  * any more.
218  */
219 static void
220 in6_ifaddloop(struct ifaddr *ifa)
221 {
222 	struct rtentry *rt;
223 
224 	/* If there is no loopback entry, allocate one. */
225 	rt = rtalloc1(ifa->ifa_addr, 0, 0);
226 	if (rt == NULL || (rt->rt_flags & RTF_HOST) == 0 ||
227 	    (rt->rt_ifp->if_flags & IFF_LOOPBACK) == 0)
228 		in6_ifloop_request(RTM_ADD, ifa);
229 	if (rt)
230 		rt->rt_refcnt--;
231 }
232 
233 /*
234  * Remove loopback rtentry of ownaddr generated by in6_ifaddloop(),
235  * if it exists.
236  */
237 static void
238 in6_ifremloop(struct ifaddr *ifa)
239 {
240 	struct in6_ifaddr *ia;
241 	struct rtentry *rt;
242 	int ia_count = 0;
243 
244 	/*
245 	 * Some of BSD variants do not remove cloned routes
246 	 * from an interface direct route, when removing the direct route
247 	 * (see comments in net/net_osdep.h).  Even for variants that do remove
248 	 * cloned routes, they could fail to remove the cloned routes when
249 	 * we handle multple addresses that share a common prefix.
250 	 * So, we should remove the route corresponding to the deleted address
251 	 * regardless of the result of in6_is_ifloop_auto().
252 	 */
253 
254 	/*
255 	 * Delete the entry only if exact one ifa exists. More than one ifa
256 	 * can exist if we assign a same single address to multiple
257 	 * (probably p2p) interfaces.
258 	 * XXX: we should avoid such a configuration in IPv6...
259 	 */
260 	for (ia = in6_ifaddr; ia; ia = ia->ia_next) {
261 		if (IN6_ARE_ADDR_EQUAL(IFA_IN6(ifa), &ia->ia_addr.sin6_addr)) {
262 			ia_count++;
263 			if (ia_count > 1)
264 				break;
265 		}
266 	}
267 
268 	if (ia_count == 1) {
269 		/*
270 		 * Before deleting, check if a corresponding loopbacked host
271 		 * route surely exists. With this check, we can avoid to
272 		 * delete an interface direct route whose destination is same
273 		 * as the address being removed. This can happen when remofing
274 		 * a subnet-router anycast address on an interface attahced
275 		 * to a shared medium.
276 		 */
277 		rt = rtalloc1(ifa->ifa_addr, 0, 0);
278 		if (rt != NULL && (rt->rt_flags & RTF_HOST) != 0 &&
279 		    (rt->rt_ifp->if_flags & IFF_LOOPBACK) != 0) {
280 			rt->rt_refcnt--;
281 			in6_ifloop_request(RTM_DELETE, ifa);
282 		}
283 	}
284 }
285 
286 int
287 in6_ifindex2scopeid(idx)
288 	int idx;
289 {
290 	struct ifnet *ifp;
291 	struct ifaddr *ifa;
292 	struct sockaddr_in6 *sin6;
293 
294 	if (idx < 0 || if_index < idx)
295 		return -1;
296 	ifp = ifnet_byindex(idx);
297 
298 	TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list)
299 	{
300 		if (ifa->ifa_addr->sa_family != AF_INET6)
301 			continue;
302 		sin6 = (struct sockaddr_in6 *)ifa->ifa_addr;
303 		if (IN6_IS_ADDR_SITELOCAL(&sin6->sin6_addr))
304 			return sin6->sin6_scope_id & 0xffff;
305 	}
306 
307 	return -1;
308 }
309 
310 int
311 in6_mask2len(mask, lim0)
312 	struct in6_addr *mask;
313 	u_char *lim0;
314 {
315 	int x = 0, y;
316 	u_char *lim = lim0, *p;
317 
318 	if (lim0 == NULL ||
319 	    lim0 - (u_char *)mask > sizeof(*mask)) /* ignore the scope_id part */
320 		lim = (u_char *)mask + sizeof(*mask);
321 	for (p = (u_char *)mask; p < lim; x++, p++) {
322 		if (*p != 0xff)
323 			break;
324 	}
325 	y = 0;
326 	if (p < lim) {
327 		for (y = 0; y < 8; y++) {
328 			if ((*p & (0x80 >> y)) == 0)
329 				break;
330 		}
331 	}
332 
333 	/*
334 	 * when the limit pointer is given, do a stricter check on the
335 	 * remaining bits.
336 	 */
337 	if (p < lim) {
338 		if (y != 0 && (*p & (0x00ff >> y)) != 0)
339 			return(-1);
340 		for (p = p + 1; p < lim; p++)
341 			if (*p != 0)
342 				return(-1);
343 	}
344 
345 	return x * 8 + y;
346 }
347 
348 void
349 in6_len2mask(mask, len)
350 	struct in6_addr *mask;
351 	int len;
352 {
353 	int i;
354 
355 	bzero(mask, sizeof(*mask));
356 	for (i = 0; i < len / 8; i++)
357 		mask->s6_addr8[i] = 0xff;
358 	if (len % 8)
359 		mask->s6_addr8[i] = (0xff00 >> (len % 8)) & 0xff;
360 }
361 
362 #define ifa2ia6(ifa)	((struct in6_ifaddr *)(ifa))
363 #define ia62ifa(ia6)	(&((ia6)->ia_ifa))
364 
365 int
366 in6_control(so, cmd, data, ifp, td)
367 	struct	socket *so;
368 	u_long cmd;
369 	caddr_t	data;
370 	struct ifnet *ifp;
371 	struct thread *td;
372 {
373 	struct	in6_ifreq *ifr = (struct in6_ifreq *)data;
374 	struct	in6_ifaddr *ia = NULL;
375 	struct	in6_aliasreq *ifra = (struct in6_aliasreq *)data;
376 	int privileged;
377 
378 	privileged = 0;
379 	if (td == NULL || !suser_td(td))
380 		privileged++;
381 
382 	switch (cmd) {
383 	case SIOCGETSGCNT_IN6:
384 	case SIOCGETMIFCNT_IN6:
385 		return (mrt6_ioctl(cmd, data));
386 	}
387 
388 	if (ifp == NULL)
389 		return(EOPNOTSUPP);
390 
391 	switch (cmd) {
392 	case SIOCSNDFLUSH_IN6:
393 	case SIOCSPFXFLUSH_IN6:
394 	case SIOCSRTRFLUSH_IN6:
395 	case SIOCSDEFIFACE_IN6:
396 	case SIOCSIFINFO_FLAGS:
397 		if (!privileged)
398 			return(EPERM);
399 		/*fall through*/
400 	case OSIOCGIFINFO_IN6:
401 	case SIOCGIFINFO_IN6:
402 	case SIOCGDRLST_IN6:
403 	case SIOCGPRLST_IN6:
404 	case SIOCGNBRINFO_IN6:
405 	case SIOCGDEFIFACE_IN6:
406 		return(nd6_ioctl(cmd, data, ifp));
407 	}
408 
409 	switch (cmd) {
410 	case SIOCSIFPREFIX_IN6:
411 	case SIOCDIFPREFIX_IN6:
412 	case SIOCAIFPREFIX_IN6:
413 	case SIOCCIFPREFIX_IN6:
414 	case SIOCSGIFPREFIX_IN6:
415 	case SIOCGIFPREFIX_IN6:
416 		log(LOG_NOTICE,
417 		    "prefix ioctls are now invalidated. "
418 		    "please use ifconfig.\n");
419 		return(EOPNOTSUPP);
420 	}
421 
422 	switch(cmd) {
423 	case SIOCSSCOPE6:
424 		if (!privileged)
425 			return(EPERM);
426 		return(scope6_set(ifp, ifr->ifr_ifru.ifru_scope_id));
427 		break;
428 	case SIOCGSCOPE6:
429 		return(scope6_get(ifp, ifr->ifr_ifru.ifru_scope_id));
430 		break;
431 	case SIOCGSCOPE6DEF:
432 		return(scope6_get_default(ifr->ifr_ifru.ifru_scope_id));
433 		break;
434 	}
435 
436 	switch (cmd) {
437 	case SIOCALIFADDR:
438 	case SIOCDLIFADDR:
439 		if (!privileged)
440 			return(EPERM);
441 		/*fall through*/
442 	case SIOCGLIFADDR:
443 		return in6_lifaddr_ioctl(so, cmd, data, ifp, td);
444 	}
445 
446 	/*
447 	 * Find address for this interface, if it exists.
448 	 */
449 	if (ifra->ifra_addr.sin6_family == AF_INET6) { /* XXX */
450 		struct sockaddr_in6 *sa6 =
451 			(struct sockaddr_in6 *)&ifra->ifra_addr;
452 
453 		if (IN6_IS_ADDR_LINKLOCAL(&sa6->sin6_addr)) {
454 			if (sa6->sin6_addr.s6_addr16[1] == 0) {
455 				/* link ID is not embedded by the user */
456 				sa6->sin6_addr.s6_addr16[1] =
457 					htons(ifp->if_index);
458 			} else if (sa6->sin6_addr.s6_addr16[1] !=
459 				    htons(ifp->if_index)) {
460 				return(EINVAL);	/* link ID contradicts */
461 			}
462 			if (sa6->sin6_scope_id) {
463 				if (sa6->sin6_scope_id !=
464 				    (u_int32_t)ifp->if_index)
465 					return(EINVAL);
466 				sa6->sin6_scope_id = 0; /* XXX: good way? */
467 			}
468 		}
469 		ia = in6ifa_ifpwithaddr(ifp, &ifra->ifra_addr.sin6_addr);
470 	}
471 
472 	switch (cmd) {
473 	case SIOCSIFADDR_IN6:
474 	case SIOCSIFDSTADDR_IN6:
475 	case SIOCSIFNETMASK_IN6:
476 		/*
477 		 * Since IPv6 allows a node to assign multiple addresses
478 		 * on a single interface, SIOCSIFxxx ioctls are not suitable
479 		 * and should be unused.
480 		 */
481 		/* we decided to obsolete this command (20000704) */
482 		return(EINVAL);
483 
484 	case SIOCDIFADDR_IN6:
485 		/*
486 		 * for IPv4, we look for existing in_ifaddr here to allow
487 		 * "ifconfig if0 delete" to remove first IPv4 address on the
488 		 * interface.  For IPv6, as the spec allow multiple interface
489 		 * address from the day one, we consider "remove the first one"
490 		 * semantics to be not preferable.
491 		 */
492 		if (ia == NULL)
493 			return(EADDRNOTAVAIL);
494 		/* FALLTHROUGH */
495 	case SIOCAIFADDR_IN6:
496 		/*
497 		 * We always require users to specify a valid IPv6 address for
498 		 * the corresponding operation.
499 		 */
500 		if (ifra->ifra_addr.sin6_family != AF_INET6 ||
501 		    ifra->ifra_addr.sin6_len != sizeof(struct sockaddr_in6))
502 			return(EAFNOSUPPORT);
503 		if (!privileged)
504 			return(EPERM);
505 
506 		break;
507 
508 	case SIOCGIFADDR_IN6:
509 		/* This interface is basically deprecated. use SIOCGIFCONF. */
510 		/* fall through */
511 	case SIOCGIFAFLAG_IN6:
512 	case SIOCGIFNETMASK_IN6:
513 	case SIOCGIFDSTADDR_IN6:
514 	case SIOCGIFALIFETIME_IN6:
515 		/* must think again about its semantics */
516 		if (ia == NULL)
517 			return(EADDRNOTAVAIL);
518 		break;
519 	case SIOCSIFALIFETIME_IN6:
520 	    {
521 		struct in6_addrlifetime *lt;
522 
523 		if (!privileged)
524 			return(EPERM);
525 		if (ia == NULL)
526 			return(EADDRNOTAVAIL);
527 		/* sanity for overflow - beware unsigned */
528 		lt = &ifr->ifr_ifru.ifru_lifetime;
529 		if (lt->ia6t_vltime != ND6_INFINITE_LIFETIME
530 		 && lt->ia6t_vltime + time_second < time_second) {
531 			return EINVAL;
532 		}
533 		if (lt->ia6t_pltime != ND6_INFINITE_LIFETIME
534 		 && lt->ia6t_pltime + time_second < time_second) {
535 			return EINVAL;
536 		}
537 		break;
538 	    }
539 	}
540 
541 	switch (cmd) {
542 
543 	case SIOCGIFADDR_IN6:
544 		ifr->ifr_addr = ia->ia_addr;
545 		break;
546 
547 	case SIOCGIFDSTADDR_IN6:
548 		if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
549 			return(EINVAL);
550 		/*
551 		 * XXX: should we check if ifa_dstaddr is NULL and return
552 		 * an error?
553 		 */
554 		ifr->ifr_dstaddr = ia->ia_dstaddr;
555 		break;
556 
557 	case SIOCGIFNETMASK_IN6:
558 		ifr->ifr_addr = ia->ia_prefixmask;
559 		break;
560 
561 	case SIOCGIFAFLAG_IN6:
562 		ifr->ifr_ifru.ifru_flags6 = ia->ia6_flags;
563 		break;
564 
565 	case SIOCGIFSTAT_IN6:
566 		if (ifp == NULL)
567 			return EINVAL;
568 		if (in6_ifstat == NULL || ifp->if_index >= in6_ifstatmax
569 		 || in6_ifstat[ifp->if_index] == NULL) {
570 			/* return EAFNOSUPPORT? */
571 			bzero(&ifr->ifr_ifru.ifru_stat,
572 				sizeof(ifr->ifr_ifru.ifru_stat));
573 		} else
574 			ifr->ifr_ifru.ifru_stat = *in6_ifstat[ifp->if_index];
575 		break;
576 
577 	case SIOCGIFSTAT_ICMP6:
578 		if (ifp == NULL)
579 			return EINVAL;
580 		if (icmp6_ifstat == NULL || ifp->if_index >= icmp6_ifstatmax ||
581 		    icmp6_ifstat[ifp->if_index] == NULL) {
582 			/* return EAFNOSUPPORT? */
583 			bzero(&ifr->ifr_ifru.ifru_stat,
584 				sizeof(ifr->ifr_ifru.ifru_icmp6stat));
585 		} else
586 			ifr->ifr_ifru.ifru_icmp6stat =
587 				*icmp6_ifstat[ifp->if_index];
588 		break;
589 
590 	case SIOCGIFALIFETIME_IN6:
591 		ifr->ifr_ifru.ifru_lifetime = ia->ia6_lifetime;
592 		break;
593 
594 	case SIOCSIFALIFETIME_IN6:
595 		ia->ia6_lifetime = ifr->ifr_ifru.ifru_lifetime;
596 		/* for sanity */
597 		if (ia->ia6_lifetime.ia6t_vltime != ND6_INFINITE_LIFETIME) {
598 			ia->ia6_lifetime.ia6t_expire =
599 				time_second + ia->ia6_lifetime.ia6t_vltime;
600 		} else
601 			ia->ia6_lifetime.ia6t_expire = 0;
602 		if (ia->ia6_lifetime.ia6t_pltime != ND6_INFINITE_LIFETIME) {
603 			ia->ia6_lifetime.ia6t_preferred =
604 				time_second + ia->ia6_lifetime.ia6t_pltime;
605 		} else
606 			ia->ia6_lifetime.ia6t_preferred = 0;
607 		break;
608 
609 	case SIOCAIFADDR_IN6:
610 	{
611 		int i, error = 0;
612 		struct nd_prefix pr0, *pr;
613 
614 		/*
615 		 * first, make or update the interface address structure,
616 		 * and link it to the list.
617 		 */
618 		if ((error = in6_update_ifa(ifp, ifra, ia)) != 0)
619 			return(error);
620 
621 		/*
622 		 * then, make the prefix on-link on the interface.
623 		 * XXX: we'd rather create the prefix before the address, but
624 		 * we need at least one address to install the corresponding
625 		 * interface route, so we configure the address first.
626 		 */
627 
628 		/*
629 		 * convert mask to prefix length (prefixmask has already
630 		 * been validated in in6_update_ifa().
631 		 */
632 		bzero(&pr0, sizeof(pr0));
633 		pr0.ndpr_ifp = ifp;
634 		pr0.ndpr_plen = in6_mask2len(&ifra->ifra_prefixmask.sin6_addr,
635 					     NULL);
636 		if (pr0.ndpr_plen == 128)
637 			break;	/* we don't need to install a host route. */
638 		pr0.ndpr_prefix = ifra->ifra_addr;
639 		pr0.ndpr_mask = ifra->ifra_prefixmask.sin6_addr;
640 		/* apply the mask for safety. */
641 		for (i = 0; i < 4; i++) {
642 			pr0.ndpr_prefix.sin6_addr.s6_addr32[i] &=
643 				ifra->ifra_prefixmask.sin6_addr.s6_addr32[i];
644 		}
645 		/*
646 		 * XXX: since we don't have enough APIs, we just set inifinity
647 		 * to lifetimes.  They can be overridden by later advertised
648 		 * RAs (when accept_rtadv is non 0), but we'd rather intend
649 		 * such a behavior.
650 		 */
651 		pr0.ndpr_raf_onlink = 1; /* should be configurable? */
652 		pr0.ndpr_raf_auto =
653 			((ifra->ifra_flags & IN6_IFF_AUTOCONF) != 0);
654 		pr0.ndpr_vltime = ifra->ifra_lifetime.ia6t_vltime;
655 		pr0.ndpr_pltime = ifra->ifra_lifetime.ia6t_pltime;
656 
657 		/* add the prefix if there's one. */
658 		if ((pr = nd6_prefix_lookup(&pr0)) == NULL) {
659 			/*
660 			 * nd6_prelist_add will install the corresponding
661 			 * interface route.
662 			 */
663 			if ((error = nd6_prelist_add(&pr0, NULL, &pr)) != 0)
664 				return(error);
665 			if (pr == NULL) {
666 				log(LOG_ERR, "nd6_prelist_add succedded but "
667 				    "no prefix\n");
668 				return(EINVAL); /* XXX panic here? */
669 			}
670 		}
671 		if ((ia = in6ifa_ifpwithaddr(ifp, &ifra->ifra_addr.sin6_addr))
672 		    == NULL) {
673 		    	/* XXX: this should not happen! */
674 			log(LOG_ERR, "in6_control: addition succeeded, but"
675 			    " no ifaddr\n");
676 		} else {
677 			if ((ia->ia6_flags & IN6_IFF_AUTOCONF) != 0 &&
678 			    ia->ia6_ndpr == NULL) { /* new autoconfed addr */
679 				ia->ia6_ndpr = pr;
680 				pr->ndpr_refcnt++;
681 
682 				/*
683 				 * If this is the first autoconf address from
684 				 * the prefix, create a temporary address
685 				 * as well (when specified).
686 				 */
687 				if (ip6_use_tempaddr &&
688 				    pr->ndpr_refcnt == 1) {
689 					int e;
690 					if ((e = in6_tmpifadd(ia, 1)) != 0) {
691 						log(LOG_NOTICE, "in6_control: "
692 						    "failed to create a "
693 						    "temporary address, "
694 						    "errno=%d\n",
695 						    e);
696 					}
697 				}
698 			}
699 
700 			/*
701 			 * this might affect the status of autoconfigured
702 			 * addresses, that is, this address might make
703 			 * other addresses detached.
704 			 */
705 			pfxlist_onlink_check();
706 		}
707 		break;
708 	}
709 
710 	case SIOCDIFADDR_IN6:
711 	{
712 		int i = 0;
713 		struct nd_prefix pr0, *pr;
714 
715 		/*
716 		 * If the address being deleted is the only one that owns
717 		 * the corresponding prefix, expire the prefix as well.
718 		 * XXX: theoretically, we don't have to warry about such
719 		 * relationship, since we separate the address management
720 		 * and the prefix management.  We do this, however, to provide
721 		 * as much backward compatibility as possible in terms of
722 		 * the ioctl operation.
723 		 */
724 		bzero(&pr0, sizeof(pr0));
725 		pr0.ndpr_ifp = ifp;
726 		pr0.ndpr_plen = in6_mask2len(&ia->ia_prefixmask.sin6_addr,
727 					     NULL);
728 		if (pr0.ndpr_plen == 128)
729 			goto purgeaddr;
730 		pr0.ndpr_prefix = ia->ia_addr;
731 		pr0.ndpr_mask = ia->ia_prefixmask.sin6_addr;
732 		for (i = 0; i < 4; i++) {
733 			pr0.ndpr_prefix.sin6_addr.s6_addr32[i] &=
734 				ia->ia_prefixmask.sin6_addr.s6_addr32[i];
735 		}
736 		/*
737 		 * The logic of the following condition is a bit complicated.
738 		 * We expire the prefix when
739 		 * 1. the address obeys autoconfiguration and it is the
740 		 *    only owner of the associated prefix, or
741 		 * 2. the address does not obey autoconf and there is no
742 		 *    other owner of the prefix.
743 		 */
744 		if ((pr = nd6_prefix_lookup(&pr0)) != NULL &&
745 		    (((ia->ia6_flags & IN6_IFF_AUTOCONF) != 0 &&
746 		      pr->ndpr_refcnt == 1) ||
747 		     ((ia->ia6_flags & IN6_IFF_AUTOCONF) == 0 &&
748 		      pr->ndpr_refcnt == 0))) {
749 			pr->ndpr_expire = 1; /* XXX: just for expiration */
750 		}
751 
752 	  purgeaddr:
753 		in6_purgeaddr(&ia->ia_ifa);
754 		break;
755 	}
756 
757 	default:
758 		if (ifp == NULL || ifp->if_ioctl == 0)
759 			return(EOPNOTSUPP);
760 		return((*ifp->if_ioctl)(ifp, cmd, data));
761 	}
762 
763 	return(0);
764 }
765 
766 /*
767  * Update parameters of an IPv6 interface address.
768  * If necessary, a new entry is created and linked into address chains.
769  * This function is separated from in6_control().
770  * XXX: should this be performed under splnet()?
771  */
772 int
773 in6_update_ifa(ifp, ifra, ia)
774 	struct ifnet *ifp;
775 	struct in6_aliasreq *ifra;
776 	struct in6_ifaddr *ia;
777 {
778 	int error = 0, hostIsNew = 0, plen = -1;
779 	struct in6_ifaddr *oia;
780 	struct sockaddr_in6 dst6;
781 	struct in6_addrlifetime *lt;
782 
783 	/* Validate parameters */
784 	if (ifp == NULL || ifra == NULL) /* this maybe redundant */
785 		return(EINVAL);
786 
787 	/*
788 	 * The destination address for a p2p link must have a family
789 	 * of AF_UNSPEC or AF_INET6.
790 	 */
791 	if ((ifp->if_flags & IFF_POINTOPOINT) != 0 &&
792 	    ifra->ifra_dstaddr.sin6_family != AF_INET6 &&
793 	    ifra->ifra_dstaddr.sin6_family != AF_UNSPEC)
794 		return(EAFNOSUPPORT);
795 	/*
796 	 * validate ifra_prefixmask.  don't check sin6_family, netmask
797 	 * does not carry fields other than sin6_len.
798 	 */
799 	if (ifra->ifra_prefixmask.sin6_len > sizeof(struct sockaddr_in6))
800 		return(EINVAL);
801 	/*
802 	 * Because the IPv6 address architecture is classless, we require
803 	 * users to specify a (non 0) prefix length (mask) for a new address.
804 	 * We also require the prefix (when specified) mask is valid, and thus
805 	 * reject a non-consecutive mask.
806 	 */
807 	if (ia == NULL && ifra->ifra_prefixmask.sin6_len == 0)
808 		return(EINVAL);
809 	if (ifra->ifra_prefixmask.sin6_len != 0) {
810 		plen = in6_mask2len(&ifra->ifra_prefixmask.sin6_addr,
811 				    (u_char *)&ifra->ifra_prefixmask +
812 				    ifra->ifra_prefixmask.sin6_len);
813 		if (plen <= 0)
814 			return(EINVAL);
815 	}
816 	else {
817 		/*
818 		 * In this case, ia must not be NULL. We just use its prefix
819 		 * length.
820 		 */
821 		plen = in6_mask2len(&ia->ia_prefixmask.sin6_addr, NULL);
822 	}
823 	/*
824 	 * If the destination address on a p2p interface is specified,
825 	 * and the address is a scoped one, validate/set the scope
826 	 * zone identifier.
827 	 */
828 	dst6 = ifra->ifra_dstaddr;
829 	if ((ifp->if_flags & (IFF_POINTOPOINT|IFF_LOOPBACK)) &&
830 	    (dst6.sin6_family == AF_INET6)) {
831 		int scopeid;
832 
833 #ifndef SCOPEDROUTING
834 		if ((error = in6_recoverscope(&dst6,
835 					      &ifra->ifra_dstaddr.sin6_addr,
836 					      ifp)) != 0)
837 			return(error);
838 #endif
839 		scopeid = in6_addr2scopeid(ifp, &dst6.sin6_addr);
840 		if (dst6.sin6_scope_id == 0) /* user omit to specify the ID. */
841 			dst6.sin6_scope_id = scopeid;
842 		else if (dst6.sin6_scope_id != scopeid)
843 			return(EINVAL); /* scope ID mismatch. */
844 #ifndef SCOPEDROUTING
845 		if ((error = in6_embedscope(&dst6.sin6_addr, &dst6, NULL, NULL))
846 		    != 0)
847 			return(error);
848 		dst6.sin6_scope_id = 0; /* XXX */
849 #endif
850 	}
851 	/*
852 	 * The destination address can be specified only for a p2p or a
853 	 * loopback interface.  If specified, the corresponding prefix length
854 	 * must be 128.
855 	 */
856 	if (ifra->ifra_dstaddr.sin6_family == AF_INET6) {
857 		if ((ifp->if_flags & (IFF_POINTOPOINT|IFF_LOOPBACK)) == 0) {
858 			/* XXX: noisy message */
859 			log(LOG_INFO, "in6_update_ifa: a destination can be "
860 			    "specified for a p2p or a loopback IF only\n");
861 			return(EINVAL);
862 		}
863 		if (plen != 128) {
864 			/*
865 			 * The following message seems noisy, but we dare to
866 			 * add it for diagnosis.
867 			 */
868 			log(LOG_INFO, "in6_update_ifa: prefixlen must be 128 "
869 			    "when dstaddr is specified\n");
870 			return(EINVAL);
871 		}
872 	}
873 	/* lifetime consistency check */
874 	lt = &ifra->ifra_lifetime;
875 	if (lt->ia6t_vltime != ND6_INFINITE_LIFETIME
876 	    && lt->ia6t_vltime + time_second < time_second) {
877 		return EINVAL;
878 	}
879 	if (lt->ia6t_vltime == 0) {
880 		/*
881 		 * the following log might be noisy, but this is a typical
882 		 * configuration mistake or a tool's bug.
883 		 */
884 		log(LOG_INFO,
885 		    "in6_update_ifa: valid lifetime is 0 for %s\n",
886 		    ip6_sprintf(&ifra->ifra_addr.sin6_addr));
887 	}
888 	if (lt->ia6t_pltime != ND6_INFINITE_LIFETIME
889 	    && lt->ia6t_pltime + time_second < time_second) {
890 		return EINVAL;
891 	}
892 
893 	/*
894 	 * If this is a new address, allocate a new ifaddr and link it
895 	 * into chains.
896 	 */
897 	if (ia == NULL) {
898 		hostIsNew = 1;
899 		/*
900 		 * When in6_update_ifa() is called in a process of a received
901 		 * RA, it is called under splnet().  So, we should call malloc
902 		 * with M_NOWAIT.
903 		 */
904 		ia = (struct in6_ifaddr *)
905 			malloc(sizeof(*ia), M_IFADDR, M_NOWAIT);
906 		if (ia == NULL)
907 			return (ENOBUFS);
908 		bzero((caddr_t)ia, sizeof(*ia));
909 		/* Initialize the address and masks */
910 		ia->ia_ifa.ifa_addr = (struct sockaddr *)&ia->ia_addr;
911 		ia->ia_addr.sin6_family = AF_INET6;
912 		ia->ia_addr.sin6_len = sizeof(ia->ia_addr);
913 		if ((ifp->if_flags & (IFF_POINTOPOINT | IFF_LOOPBACK)) != 0) {
914 			/*
915 			 * XXX: some functions expect that ifa_dstaddr is not
916 			 * NULL for p2p interfaces.
917 			 */
918 			ia->ia_ifa.ifa_dstaddr
919 				= (struct sockaddr *)&ia->ia_dstaddr;
920 		} else {
921 			ia->ia_ifa.ifa_dstaddr = NULL;
922 		}
923 		ia->ia_ifa.ifa_netmask
924 			= (struct sockaddr *)&ia->ia_prefixmask;
925 
926 		ia->ia_ifp = ifp;
927 		if ((oia = in6_ifaddr) != NULL) {
928 			for ( ; oia->ia_next; oia = oia->ia_next)
929 				continue;
930 			oia->ia_next = ia;
931 		} else
932 			in6_ifaddr = ia;
933 
934 		TAILQ_INSERT_TAIL(&ifp->if_addrlist, &ia->ia_ifa,
935 				  ifa_list);
936 	}
937 
938 	/* set prefix mask */
939 	if (ifra->ifra_prefixmask.sin6_len) {
940 		/*
941 		 * We prohibit changing the prefix length of an existing
942 		 * address, because
943 		 * + such an operation should be rare in IPv6, and
944 		 * + the operation would confuse prefix management.
945 		 */
946 		if (ia->ia_prefixmask.sin6_len &&
947 		    in6_mask2len(&ia->ia_prefixmask.sin6_addr, NULL) != plen) {
948 			log(LOG_INFO, "in6_update_ifa: the prefix length of an"
949 			    " existing (%s) address should not be changed\n",
950 			    ip6_sprintf(&ia->ia_addr.sin6_addr));
951 			error = EINVAL;
952 			goto unlink;
953 		}
954 		ia->ia_prefixmask = ifra->ifra_prefixmask;
955 	}
956 
957 	/*
958 	 * If a new destination address is specified, scrub the old one and
959 	 * install the new destination.  Note that the interface must be
960 	 * p2p or loopback (see the check above.)
961 	 */
962 	if (dst6.sin6_family == AF_INET6 &&
963 	    !IN6_ARE_ADDR_EQUAL(&dst6.sin6_addr,
964 				&ia->ia_dstaddr.sin6_addr)) {
965 		int e;
966 
967 		if ((ia->ia_flags & IFA_ROUTE) != 0 &&
968 		    (e = rtinit(&(ia->ia_ifa), (int)RTM_DELETE, RTF_HOST))
969 		    != 0) {
970 			log(LOG_ERR, "in6_update_ifa: failed to remove "
971 			    "a route to the old destination: %s\n",
972 			    ip6_sprintf(&ia->ia_addr.sin6_addr));
973 			/* proceed anyway... */
974 		}
975 		else
976 			ia->ia_flags &= ~IFA_ROUTE;
977 		ia->ia_dstaddr = dst6;
978 	}
979 
980 	/* reset the interface and routing table appropriately. */
981 	if ((error = in6_ifinit(ifp, ia, &ifra->ifra_addr, hostIsNew)) != 0)
982 		goto unlink;
983 
984 	/*
985 	 * Beyond this point, we should call in6_purgeaddr upon an error,
986 	 * not just go to unlink.
987 	 */
988 
989 #if 0				/* disable this mechanism for now */
990 	/* update prefix list */
991 	if (hostIsNew &&
992 	    (ifra->ifra_flags & IN6_IFF_NOPFX) == 0) { /* XXX */
993 		int iilen;
994 
995 		iilen = (sizeof(ia->ia_prefixmask.sin6_addr) << 3) - plen;
996 		if ((error = in6_prefix_add_ifid(iilen, ia)) != 0) {
997 			in6_purgeaddr((struct ifaddr *)ia);
998 			return(error);
999 		}
1000 	}
1001 #endif
1002 
1003 	if ((ifp->if_flags & IFF_MULTICAST) != 0) {
1004 		struct sockaddr_in6 mltaddr, mltmask;
1005 		struct in6_multi *in6m;
1006 
1007 		if (hostIsNew) {
1008 			/*
1009 			 * join solicited multicast addr for new host id
1010 			 */
1011 			struct in6_addr llsol;
1012 			bzero(&llsol, sizeof(struct in6_addr));
1013 			llsol.s6_addr16[0] = htons(0xff02);
1014 			llsol.s6_addr16[1] = htons(ifp->if_index);
1015 			llsol.s6_addr32[1] = 0;
1016 			llsol.s6_addr32[2] = htonl(1);
1017 			llsol.s6_addr32[3] =
1018 				ifra->ifra_addr.sin6_addr.s6_addr32[3];
1019 			llsol.s6_addr8[12] = 0xff;
1020 			(void)in6_addmulti(&llsol, ifp, &error);
1021 			if (error != 0) {
1022 				log(LOG_WARNING,
1023 				    "in6_update_ifa: addmulti failed for "
1024 				    "%s on %s (errno=%d)\n",
1025 				    ip6_sprintf(&llsol), if_name(ifp),
1026 				    error);
1027 				in6_purgeaddr((struct ifaddr *)ia);
1028 				return(error);
1029 			}
1030 		}
1031 
1032 		bzero(&mltmask, sizeof(mltmask));
1033 		mltmask.sin6_len = sizeof(struct sockaddr_in6);
1034 		mltmask.sin6_family = AF_INET6;
1035 		mltmask.sin6_addr = in6mask32;
1036 
1037 		/*
1038 		 * join link-local all-nodes address
1039 		 */
1040 		bzero(&mltaddr, sizeof(mltaddr));
1041 		mltaddr.sin6_len = sizeof(struct sockaddr_in6);
1042 		mltaddr.sin6_family = AF_INET6;
1043 		mltaddr.sin6_addr = in6addr_linklocal_allnodes;
1044 		mltaddr.sin6_addr.s6_addr16[1] = htons(ifp->if_index);
1045 
1046 		IN6_LOOKUP_MULTI(mltaddr.sin6_addr, ifp, in6m);
1047 		if (in6m == NULL) {
1048 			rtrequest(RTM_ADD,
1049 				  (struct sockaddr *)&mltaddr,
1050 				  (struct sockaddr *)&ia->ia_addr,
1051 				  (struct sockaddr *)&mltmask,
1052 				  RTF_UP|RTF_CLONING,  /* xxx */
1053 				  (struct rtentry **)0);
1054 			(void)in6_addmulti(&mltaddr.sin6_addr, ifp, &error);
1055 			if (error != 0) {
1056 				log(LOG_WARNING,
1057 				    "in6_update_ifa: addmulti failed for "
1058 				    "%s on %s (errno=%d)\n",
1059 				    ip6_sprintf(&mltaddr.sin6_addr),
1060 				    if_name(ifp), error);
1061 			}
1062 		}
1063 
1064 		/*
1065 		 * join node information group address
1066 		 */
1067 #define hostnamelen	strlen(hostname)
1068 		if (in6_nigroup(ifp, hostname, hostnamelen, &mltaddr.sin6_addr)
1069 		    == 0) {
1070 			IN6_LOOKUP_MULTI(mltaddr.sin6_addr, ifp, in6m);
1071 			if (in6m == NULL && ia != NULL) {
1072 				(void)in6_addmulti(&mltaddr.sin6_addr,
1073 				    ifp, &error);
1074 				if (error != 0) {
1075 					log(LOG_WARNING, "in6_update_ifa: "
1076 					    "addmulti failed for "
1077 					    "%s on %s (errno=%d)\n",
1078 					    ip6_sprintf(&mltaddr.sin6_addr),
1079 					    if_name(ifp), error);
1080 				}
1081 			}
1082 		}
1083 #undef hostnamelen
1084 
1085 		/*
1086 		 * join node-local all-nodes address, on loopback.
1087 		 * XXX: since "node-local" is obsoleted by interface-local,
1088 		 *      we have to join the group on every interface with
1089 		 *      some interface-boundary restriction.
1090 		 */
1091 		if (ifp->if_flags & IFF_LOOPBACK) {
1092 			struct in6_ifaddr *ia_loop;
1093 
1094 			struct in6_addr loop6 = in6addr_loopback;
1095 			ia_loop = in6ifa_ifpwithaddr(ifp, &loop6);
1096 
1097 			mltaddr.sin6_addr = in6addr_nodelocal_allnodes;
1098 
1099 			IN6_LOOKUP_MULTI(mltaddr.sin6_addr, ifp, in6m);
1100 			if (in6m == NULL && ia_loop != NULL) {
1101 				rtrequest(RTM_ADD,
1102 					  (struct sockaddr *)&mltaddr,
1103 					  (struct sockaddr *)&ia_loop->ia_addr,
1104 					  (struct sockaddr *)&mltmask,
1105 					  RTF_UP,
1106 					  (struct rtentry **)0);
1107 				(void)in6_addmulti(&mltaddr.sin6_addr, ifp,
1108 						   &error);
1109 				if (error != 0) {
1110 					log(LOG_WARNING, "in6_update_ifa: "
1111 					    "addmulti failed for %s on %s "
1112 					    "(errno=%d)\n",
1113 					    ip6_sprintf(&mltaddr.sin6_addr),
1114 					    if_name(ifp), error);
1115 				}
1116 			}
1117 		}
1118 	}
1119 
1120 	ia->ia6_flags = ifra->ifra_flags;
1121 	ia->ia6_flags &= ~IN6_IFF_DUPLICATED;	/*safety*/
1122 	ia->ia6_flags &= ~IN6_IFF_NODAD;	/* Mobile IPv6 */
1123 
1124 	ia->ia6_lifetime = ifra->ifra_lifetime;
1125 	/* for sanity */
1126 	if (ia->ia6_lifetime.ia6t_vltime != ND6_INFINITE_LIFETIME) {
1127 		ia->ia6_lifetime.ia6t_expire =
1128 			time_second + ia->ia6_lifetime.ia6t_vltime;
1129 	} else
1130 		ia->ia6_lifetime.ia6t_expire = 0;
1131 	if (ia->ia6_lifetime.ia6t_pltime != ND6_INFINITE_LIFETIME) {
1132 		ia->ia6_lifetime.ia6t_preferred =
1133 			time_second + ia->ia6_lifetime.ia6t_pltime;
1134 	} else
1135 		ia->ia6_lifetime.ia6t_preferred = 0;
1136 
1137 	/*
1138 	 * make sure to initialize ND6 information.  this is to workaround
1139 	 * issues with interfaces with IPv6 addresses, which have never brought
1140 	 * up.  We are assuming that it is safe to nd6_ifattach multiple times.
1141 	 */
1142 	nd6_ifattach(ifp);
1143 
1144 	/*
1145 	 * Perform DAD, if needed.
1146 	 * XXX It may be of use, if we can administratively
1147 	 * disable DAD.
1148 	 */
1149 	if (in6if_do_dad(ifp) && (ifra->ifra_flags & IN6_IFF_NODAD) == 0) {
1150 		ia->ia6_flags |= IN6_IFF_TENTATIVE;
1151 		nd6_dad_start((struct ifaddr *)ia, NULL);
1152 	}
1153 
1154 	return(error);
1155 
1156   unlink:
1157 	/*
1158 	 * XXX: if a change of an existing address failed, keep the entry
1159 	 * anyway.
1160 	 */
1161 	if (hostIsNew)
1162 		in6_unlink_ifa(ia, ifp);
1163 	return(error);
1164 }
1165 
1166 void
1167 in6_purgeaddr(ifa)
1168 	struct ifaddr *ifa;
1169 {
1170 	struct ifnet *ifp = ifa->ifa_ifp;
1171 	struct in6_ifaddr *ia = (struct in6_ifaddr *) ifa;
1172 
1173 	/* stop DAD processing */
1174 	nd6_dad_stop(ifa);
1175 
1176 	/*
1177 	 * delete route to the destination of the address being purged.
1178 	 * The interface must be p2p or loopback in this case.
1179 	 */
1180 	if ((ia->ia_flags & IFA_ROUTE) != 0 && ia->ia_dstaddr.sin6_len != 0) {
1181 		int e;
1182 
1183 		if ((e = rtinit(&(ia->ia_ifa), (int)RTM_DELETE, RTF_HOST))
1184 		    != 0) {
1185 			log(LOG_ERR, "in6_purgeaddr: failed to remove "
1186 			    "a route to the p2p destination: %s on %s, "
1187 			    "errno=%d\n",
1188 			    ip6_sprintf(&ia->ia_addr.sin6_addr), if_name(ifp),
1189 			    e);
1190 			/* proceed anyway... */
1191 		}
1192 		else
1193 			ia->ia_flags &= ~IFA_ROUTE;
1194 	}
1195 
1196 	/* Remove ownaddr's loopback rtentry, if it exists. */
1197 	in6_ifremloop(&(ia->ia_ifa));
1198 
1199 	if (ifp->if_flags & IFF_MULTICAST) {
1200 		/*
1201 		 * delete solicited multicast addr for deleting host id
1202 		 */
1203 		struct in6_multi *in6m;
1204 		struct in6_addr llsol;
1205 		bzero(&llsol, sizeof(struct in6_addr));
1206 		llsol.s6_addr16[0] = htons(0xff02);
1207 		llsol.s6_addr16[1] = htons(ifp->if_index);
1208 		llsol.s6_addr32[1] = 0;
1209 		llsol.s6_addr32[2] = htonl(1);
1210 		llsol.s6_addr32[3] =
1211 			ia->ia_addr.sin6_addr.s6_addr32[3];
1212 		llsol.s6_addr8[12] = 0xff;
1213 
1214 		IN6_LOOKUP_MULTI(llsol, ifp, in6m);
1215 		if (in6m)
1216 			in6_delmulti(in6m);
1217 	}
1218 
1219 	in6_unlink_ifa(ia, ifp);
1220 }
1221 
1222 static void
1223 in6_unlink_ifa(ia, ifp)
1224 	struct in6_ifaddr *ia;
1225 	struct ifnet *ifp;
1226 {
1227 	int plen, iilen;
1228 	struct in6_ifaddr *oia;
1229 	int	s = splnet();
1230 
1231 	TAILQ_REMOVE(&ifp->if_addrlist, &ia->ia_ifa, ifa_list);
1232 
1233 	oia = ia;
1234 	if (oia == (ia = in6_ifaddr))
1235 		in6_ifaddr = ia->ia_next;
1236 	else {
1237 		while (ia->ia_next && (ia->ia_next != oia))
1238 			ia = ia->ia_next;
1239 		if (ia->ia_next)
1240 			ia->ia_next = oia->ia_next;
1241 		else {
1242 			/* search failed */
1243 			printf("Couldn't unlink in6_ifaddr from in6_ifaddr\n");
1244 		}
1245 	}
1246 
1247 	if (oia->ia6_ifpr) {	/* check for safety */
1248 		plen = in6_mask2len(&oia->ia_prefixmask.sin6_addr, NULL);
1249 		iilen = (sizeof(oia->ia_prefixmask.sin6_addr) << 3) - plen;
1250 		in6_prefix_remove_ifid(iilen, oia);
1251 	}
1252 
1253 	/*
1254 	 * When an autoconfigured address is being removed, release the
1255 	 * reference to the base prefix.  Also, since the release might
1256 	 * affect the status of other (detached) addresses, call
1257 	 * pfxlist_onlink_check().
1258 	 */
1259 	if ((oia->ia6_flags & IN6_IFF_AUTOCONF) != 0) {
1260 		if (oia->ia6_ndpr == NULL) {
1261 			log(LOG_NOTICE, "in6_unlink_ifa: autoconf'ed address "
1262 			    "%p has no prefix\n", oia);
1263 		} else {
1264 			oia->ia6_ndpr->ndpr_refcnt--;
1265 			oia->ia6_flags &= ~IN6_IFF_AUTOCONF;
1266 			oia->ia6_ndpr = NULL;
1267 		}
1268 
1269 		pfxlist_onlink_check();
1270 	}
1271 
1272 	/*
1273 	 * release another refcnt for the link from in6_ifaddr.
1274 	 * Note that we should decrement the refcnt at least once for all *BSD.
1275 	 */
1276 	IFAFREE(&oia->ia_ifa);
1277 
1278 	splx(s);
1279 }
1280 
1281 void
1282 in6_purgeif(ifp)
1283 	struct ifnet *ifp;
1284 {
1285 	struct ifaddr *ifa, *nifa;
1286 
1287 	for (ifa = TAILQ_FIRST(&ifp->if_addrlist); ifa != NULL; ifa = nifa)
1288 	{
1289 		nifa = TAILQ_NEXT(ifa, ifa_list);
1290 		if (ifa->ifa_addr->sa_family != AF_INET6)
1291 			continue;
1292 		in6_purgeaddr(ifa);
1293 	}
1294 
1295 	in6_ifdetach(ifp);
1296 }
1297 
1298 /*
1299  * SIOC[GAD]LIFADDR.
1300  *	SIOCGLIFADDR: get first address. (?)
1301  *	SIOCGLIFADDR with IFLR_PREFIX:
1302  *		get first address that matches the specified prefix.
1303  *	SIOCALIFADDR: add the specified address.
1304  *	SIOCALIFADDR with IFLR_PREFIX:
1305  *		add the specified prefix, filling hostid part from
1306  *		the first link-local address.  prefixlen must be <= 64.
1307  *	SIOCDLIFADDR: delete the specified address.
1308  *	SIOCDLIFADDR with IFLR_PREFIX:
1309  *		delete the first address that matches the specified prefix.
1310  * return values:
1311  *	EINVAL on invalid parameters
1312  *	EADDRNOTAVAIL on prefix match failed/specified address not found
1313  *	other values may be returned from in6_ioctl()
1314  *
1315  * NOTE: SIOCALIFADDR(with IFLR_PREFIX set) allows prefixlen less than 64.
1316  * this is to accomodate address naming scheme other than RFC2374,
1317  * in the future.
1318  * RFC2373 defines interface id to be 64bit, but it allows non-RFC2374
1319  * address encoding scheme. (see figure on page 8)
1320  */
1321 static int
1322 in6_lifaddr_ioctl(so, cmd, data, ifp, td)
1323 	struct socket *so;
1324 	u_long cmd;
1325 	caddr_t	data;
1326 	struct ifnet *ifp;
1327 	struct thread *td;
1328 {
1329 	struct if_laddrreq *iflr = (struct if_laddrreq *)data;
1330 	struct ifaddr *ifa;
1331 	struct sockaddr *sa;
1332 
1333 	/* sanity checks */
1334 	if (!data || !ifp) {
1335 		panic("invalid argument to in6_lifaddr_ioctl");
1336 		/*NOTRECHED*/
1337 	}
1338 
1339 	switch (cmd) {
1340 	case SIOCGLIFADDR:
1341 		/* address must be specified on GET with IFLR_PREFIX */
1342 		if ((iflr->flags & IFLR_PREFIX) == 0)
1343 			break;
1344 		/*FALLTHROUGH*/
1345 	case SIOCALIFADDR:
1346 	case SIOCDLIFADDR:
1347 		/* address must be specified on ADD and DELETE */
1348 		sa = (struct sockaddr *)&iflr->addr;
1349 		if (sa->sa_family != AF_INET6)
1350 			return EINVAL;
1351 		if (sa->sa_len != sizeof(struct sockaddr_in6))
1352 			return EINVAL;
1353 		/* XXX need improvement */
1354 		sa = (struct sockaddr *)&iflr->dstaddr;
1355 		if (sa->sa_family && sa->sa_family != AF_INET6)
1356 			return EINVAL;
1357 		if (sa->sa_len && sa->sa_len != sizeof(struct sockaddr_in6))
1358 			return EINVAL;
1359 		break;
1360 	default: /*shouldn't happen*/
1361 #if 0
1362 		panic("invalid cmd to in6_lifaddr_ioctl");
1363 		/*NOTREACHED*/
1364 #else
1365 		return EOPNOTSUPP;
1366 #endif
1367 	}
1368 	if (sizeof(struct in6_addr) * 8 < iflr->prefixlen)
1369 		return EINVAL;
1370 
1371 	switch (cmd) {
1372 	case SIOCALIFADDR:
1373 	    {
1374 		struct in6_aliasreq ifra;
1375 		struct in6_addr *hostid = NULL;
1376 		int prefixlen;
1377 
1378 		if ((iflr->flags & IFLR_PREFIX) != 0) {
1379 			struct sockaddr_in6 *sin6;
1380 
1381 			/*
1382 			 * hostid is to fill in the hostid part of the
1383 			 * address.  hostid points to the first link-local
1384 			 * address attached to the interface.
1385 			 */
1386 			ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp, 0);
1387 			if (!ifa)
1388 				return EADDRNOTAVAIL;
1389 			hostid = IFA_IN6(ifa);
1390 
1391 		 	/* prefixlen must be <= 64. */
1392 			if (64 < iflr->prefixlen)
1393 				return EINVAL;
1394 			prefixlen = iflr->prefixlen;
1395 
1396 			/* hostid part must be zero. */
1397 			sin6 = (struct sockaddr_in6 *)&iflr->addr;
1398 			if (sin6->sin6_addr.s6_addr32[2] != 0
1399 			 || sin6->sin6_addr.s6_addr32[3] != 0) {
1400 				return EINVAL;
1401 			}
1402 		} else
1403 			prefixlen = iflr->prefixlen;
1404 
1405 		/* copy args to in6_aliasreq, perform ioctl(SIOCAIFADDR_IN6). */
1406 		bzero(&ifra, sizeof(ifra));
1407 		bcopy(iflr->iflr_name, ifra.ifra_name,
1408 			sizeof(ifra.ifra_name));
1409 
1410 		bcopy(&iflr->addr, &ifra.ifra_addr,
1411 			((struct sockaddr *)&iflr->addr)->sa_len);
1412 		if (hostid) {
1413 			/* fill in hostid part */
1414 			ifra.ifra_addr.sin6_addr.s6_addr32[2] =
1415 				hostid->s6_addr32[2];
1416 			ifra.ifra_addr.sin6_addr.s6_addr32[3] =
1417 				hostid->s6_addr32[3];
1418 		}
1419 
1420 		if (((struct sockaddr *)&iflr->dstaddr)->sa_family) {	/*XXX*/
1421 			bcopy(&iflr->dstaddr, &ifra.ifra_dstaddr,
1422 				((struct sockaddr *)&iflr->dstaddr)->sa_len);
1423 			if (hostid) {
1424 				ifra.ifra_dstaddr.sin6_addr.s6_addr32[2] =
1425 					hostid->s6_addr32[2];
1426 				ifra.ifra_dstaddr.sin6_addr.s6_addr32[3] =
1427 					hostid->s6_addr32[3];
1428 			}
1429 		}
1430 
1431 		ifra.ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6);
1432 		in6_len2mask(&ifra.ifra_prefixmask.sin6_addr, prefixlen);
1433 
1434 		ifra.ifra_flags = iflr->flags & ~IFLR_PREFIX;
1435 		return in6_control(so, SIOCAIFADDR_IN6, (caddr_t)&ifra, ifp, td);
1436 	    }
1437 	case SIOCGLIFADDR:
1438 	case SIOCDLIFADDR:
1439 	    {
1440 		struct in6_ifaddr *ia;
1441 		struct in6_addr mask, candidate, match;
1442 		struct sockaddr_in6 *sin6;
1443 		int cmp;
1444 
1445 		bzero(&mask, sizeof(mask));
1446 		if (iflr->flags & IFLR_PREFIX) {
1447 			/* lookup a prefix rather than address. */
1448 			in6_len2mask(&mask, iflr->prefixlen);
1449 
1450 			sin6 = (struct sockaddr_in6 *)&iflr->addr;
1451 			bcopy(&sin6->sin6_addr, &match, sizeof(match));
1452 			match.s6_addr32[0] &= mask.s6_addr32[0];
1453 			match.s6_addr32[1] &= mask.s6_addr32[1];
1454 			match.s6_addr32[2] &= mask.s6_addr32[2];
1455 			match.s6_addr32[3] &= mask.s6_addr32[3];
1456 
1457 			/* if you set extra bits, that's wrong */
1458 			if (bcmp(&match, &sin6->sin6_addr, sizeof(match)))
1459 				return EINVAL;
1460 
1461 			cmp = 1;
1462 		} else {
1463 			if (cmd == SIOCGLIFADDR) {
1464 				/* on getting an address, take the 1st match */
1465 				cmp = 0;	/*XXX*/
1466 			} else {
1467 				/* on deleting an address, do exact match */
1468 				in6_len2mask(&mask, 128);
1469 				sin6 = (struct sockaddr_in6 *)&iflr->addr;
1470 				bcopy(&sin6->sin6_addr, &match, sizeof(match));
1471 
1472 				cmp = 1;
1473 			}
1474 		}
1475 
1476 		TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list)
1477 		{
1478 			if (ifa->ifa_addr->sa_family != AF_INET6)
1479 				continue;
1480 			if (!cmp)
1481 				break;
1482 
1483 			bcopy(IFA_IN6(ifa), &candidate, sizeof(candidate));
1484 #ifndef SCOPEDROUTING
1485 			/*
1486 			 * XXX: this is adhoc, but is necessary to allow
1487 			 * a user to specify fe80::/64 (not /10) for a
1488 			 * link-local address.
1489 			 */
1490 			if (IN6_IS_ADDR_LINKLOCAL(&candidate))
1491 				candidate.s6_addr16[1] = 0;
1492 #endif
1493 			candidate.s6_addr32[0] &= mask.s6_addr32[0];
1494 			candidate.s6_addr32[1] &= mask.s6_addr32[1];
1495 			candidate.s6_addr32[2] &= mask.s6_addr32[2];
1496 			candidate.s6_addr32[3] &= mask.s6_addr32[3];
1497 			if (IN6_ARE_ADDR_EQUAL(&candidate, &match))
1498 				break;
1499 		}
1500 		if (!ifa)
1501 			return EADDRNOTAVAIL;
1502 		ia = ifa2ia6(ifa);
1503 
1504 		if (cmd == SIOCGLIFADDR) {
1505 #ifndef SCOPEDROUTING
1506 			struct sockaddr_in6 *s6;
1507 #endif
1508 
1509 			/* fill in the if_laddrreq structure */
1510 			bcopy(&ia->ia_addr, &iflr->addr, ia->ia_addr.sin6_len);
1511 #ifndef SCOPEDROUTING		/* XXX see above */
1512 			s6 = (struct sockaddr_in6 *)&iflr->addr;
1513 			if (IN6_IS_ADDR_LINKLOCAL(&s6->sin6_addr)) {
1514 				s6->sin6_addr.s6_addr16[1] = 0;
1515 				s6->sin6_scope_id =
1516 					in6_addr2scopeid(ifp, &s6->sin6_addr);
1517 			}
1518 #endif
1519 			if ((ifp->if_flags & IFF_POINTOPOINT) != 0) {
1520 				bcopy(&ia->ia_dstaddr, &iflr->dstaddr,
1521 					ia->ia_dstaddr.sin6_len);
1522 #ifndef SCOPEDROUTING		/* XXX see above */
1523 				s6 = (struct sockaddr_in6 *)&iflr->dstaddr;
1524 				if (IN6_IS_ADDR_LINKLOCAL(&s6->sin6_addr)) {
1525 					s6->sin6_addr.s6_addr16[1] = 0;
1526 					s6->sin6_scope_id =
1527 						in6_addr2scopeid(ifp,
1528 								 &s6->sin6_addr);
1529 				}
1530 #endif
1531 			} else
1532 				bzero(&iflr->dstaddr, sizeof(iflr->dstaddr));
1533 
1534 			iflr->prefixlen =
1535 				in6_mask2len(&ia->ia_prefixmask.sin6_addr,
1536 					     NULL);
1537 
1538 			iflr->flags = ia->ia6_flags;	/*XXX*/
1539 
1540 			return 0;
1541 		} else {
1542 			struct in6_aliasreq ifra;
1543 
1544 			/* fill in6_aliasreq and do ioctl(SIOCDIFADDR_IN6) */
1545 			bzero(&ifra, sizeof(ifra));
1546 			bcopy(iflr->iflr_name, ifra.ifra_name,
1547 				sizeof(ifra.ifra_name));
1548 
1549 			bcopy(&ia->ia_addr, &ifra.ifra_addr,
1550 				ia->ia_addr.sin6_len);
1551 			if ((ifp->if_flags & IFF_POINTOPOINT) != 0) {
1552 				bcopy(&ia->ia_dstaddr, &ifra.ifra_dstaddr,
1553 					ia->ia_dstaddr.sin6_len);
1554 			} else {
1555 				bzero(&ifra.ifra_dstaddr,
1556 				    sizeof(ifra.ifra_dstaddr));
1557 			}
1558 			bcopy(&ia->ia_prefixmask, &ifra.ifra_dstaddr,
1559 				ia->ia_prefixmask.sin6_len);
1560 
1561 			ifra.ifra_flags = ia->ia6_flags;
1562 			return in6_control(so, SIOCDIFADDR_IN6, (caddr_t)&ifra,
1563 				ifp, td);
1564 		}
1565 	    }
1566 	}
1567 
1568 	return EOPNOTSUPP;	/*just for safety*/
1569 }
1570 
1571 /*
1572  * Initialize an interface's intetnet6 address
1573  * and routing table entry.
1574  */
1575 static int
1576 in6_ifinit(ifp, ia, sin6, newhost)
1577 	struct ifnet *ifp;
1578 	struct in6_ifaddr *ia;
1579 	struct sockaddr_in6 *sin6;
1580 	int newhost;
1581 {
1582 	int	error = 0, plen, ifacount = 0;
1583 	int	s = splimp();
1584 	struct ifaddr *ifa;
1585 
1586 	/*
1587 	 * Give the interface a chance to initialize
1588 	 * if this is its first address,
1589 	 * and to validate the address if necessary.
1590 	 */
1591 	TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list)
1592 	{
1593 		if (ifa->ifa_addr == NULL)
1594 			continue;	/* just for safety */
1595 		if (ifa->ifa_addr->sa_family != AF_INET6)
1596 			continue;
1597 		ifacount++;
1598 	}
1599 
1600 	ia->ia_addr = *sin6;
1601 
1602 	if (ifacount <= 1 && ifp->if_ioctl &&
1603 	    (error = (*ifp->if_ioctl)(ifp, SIOCSIFADDR, (caddr_t)ia))) {
1604 		splx(s);
1605 		return(error);
1606 	}
1607 	splx(s);
1608 
1609 	ia->ia_ifa.ifa_metric = ifp->if_metric;
1610 
1611 	/* we could do in(6)_socktrim here, but just omit it at this moment. */
1612 
1613 	/*
1614 	 * Special case:
1615 	 * If the destination address is specified for a point-to-point
1616 	 * interface, install a route to the destination as an interface
1617 	 * direct route.
1618 	 */
1619 	plen = in6_mask2len(&ia->ia_prefixmask.sin6_addr, NULL); /* XXX */
1620 	if (plen == 128 && ia->ia_dstaddr.sin6_family == AF_INET6) {
1621 		if ((error = rtinit(&(ia->ia_ifa), (int)RTM_ADD,
1622 				    RTF_UP | RTF_HOST)) != 0)
1623 			return(error);
1624 		ia->ia_flags |= IFA_ROUTE;
1625 	}
1626 	if (plen < 128) {
1627 		/*
1628 		 * The RTF_CLONING flag is necessary for in6_is_ifloop_auto().
1629 		 */
1630 		ia->ia_ifa.ifa_flags |= RTF_CLONING;
1631 	}
1632 
1633 	/* Add ownaddr as loopback rtentry, if necessary(ex. on p2p link). */
1634 	if (newhost) {
1635 		/* set the rtrequest function to create llinfo */
1636 		ia->ia_ifa.ifa_rtrequest = nd6_rtrequest;
1637 		in6_ifaddloop(&(ia->ia_ifa));
1638 	}
1639 
1640 	return(error);
1641 }
1642 
1643 /*
1644  * Add an address to the list of IP6 multicast addresses for a
1645  * given interface.
1646  */
1647 struct	in6_multi *
1648 in6_addmulti(maddr6, ifp, errorp)
1649 	struct in6_addr *maddr6;
1650 	struct ifnet *ifp;
1651 	int *errorp;
1652 {
1653 	struct	in6_multi *in6m;
1654 	struct sockaddr_in6 sin6;
1655 	struct ifmultiaddr *ifma;
1656 	int	s = splnet();
1657 
1658 	*errorp = 0;
1659 
1660 	/*
1661 	 * Call generic routine to add membership or increment
1662 	 * refcount.  It wants addresses in the form of a sockaddr,
1663 	 * so we build one here (being careful to zero the unused bytes).
1664 	 */
1665 	bzero(&sin6, sizeof sin6);
1666 	sin6.sin6_family = AF_INET6;
1667 	sin6.sin6_len = sizeof sin6;
1668 	sin6.sin6_addr = *maddr6;
1669 	*errorp = if_addmulti(ifp, (struct sockaddr *)&sin6, &ifma);
1670 	if (*errorp) {
1671 		splx(s);
1672 		return 0;
1673 	}
1674 
1675 	/*
1676 	 * If ifma->ifma_protospec is null, then if_addmulti() created
1677 	 * a new record.  Otherwise, we are done.
1678 	 */
1679 	if (ifma->ifma_protospec != 0)
1680 		return ifma->ifma_protospec;
1681 
1682 	/* XXX - if_addmulti uses M_WAITOK.  Can this really be called
1683 	   at interrupt time?  If so, need to fix if_addmulti. XXX */
1684 	in6m = (struct in6_multi *)malloc(sizeof(*in6m), M_IPMADDR, M_NOWAIT);
1685 	if (in6m == NULL) {
1686 		splx(s);
1687 		return (NULL);
1688 	}
1689 
1690 	bzero(in6m, sizeof *in6m);
1691 	in6m->in6m_addr = *maddr6;
1692 	in6m->in6m_ifp = ifp;
1693 	in6m->in6m_ifma = ifma;
1694 	ifma->ifma_protospec = in6m;
1695 	LIST_INSERT_HEAD(&in6_multihead, in6m, in6m_entry);
1696 
1697 	/*
1698 	 * Let MLD6 know that we have joined a new IP6 multicast
1699 	 * group.
1700 	 */
1701 	mld6_start_listening(in6m);
1702 	splx(s);
1703 	return(in6m);
1704 }
1705 
1706 /*
1707  * Delete a multicast address record.
1708  */
1709 void
1710 in6_delmulti(in6m)
1711 	struct in6_multi *in6m;
1712 {
1713 	struct ifmultiaddr *ifma = in6m->in6m_ifma;
1714 	int	s = splnet();
1715 
1716 	if (ifma->ifma_refcount == 1) {
1717 		/*
1718 		 * No remaining claims to this record; let MLD6 know
1719 		 * that we are leaving the multicast group.
1720 		 */
1721 		mld6_stop_listening(in6m);
1722 		ifma->ifma_protospec = 0;
1723 		LIST_REMOVE(in6m, in6m_entry);
1724 		free(in6m, M_IPMADDR);
1725 	}
1726 	/* XXX - should be separate API for when we have an ifma? */
1727 	if_delmulti(ifma->ifma_ifp, ifma->ifma_addr);
1728 	splx(s);
1729 }
1730 
1731 /*
1732  * Find an IPv6 interface link-local address specific to an interface.
1733  */
1734 struct in6_ifaddr *
1735 in6ifa_ifpforlinklocal(ifp, ignoreflags)
1736 	struct ifnet *ifp;
1737 	int ignoreflags;
1738 {
1739 	struct ifaddr *ifa;
1740 
1741 	TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list)
1742 	{
1743 		if (ifa->ifa_addr == NULL)
1744 			continue;	/* just for safety */
1745 		if (ifa->ifa_addr->sa_family != AF_INET6)
1746 			continue;
1747 		if (IN6_IS_ADDR_LINKLOCAL(IFA_IN6(ifa))) {
1748 			if ((((struct in6_ifaddr *)ifa)->ia6_flags &
1749 			     ignoreflags) != 0)
1750 				continue;
1751 			break;
1752 		}
1753 	}
1754 
1755 	return((struct in6_ifaddr *)ifa);
1756 }
1757 
1758 
1759 /*
1760  * find the internet address corresponding to a given interface and address.
1761  */
1762 struct in6_ifaddr *
1763 in6ifa_ifpwithaddr(ifp, addr)
1764 	struct ifnet *ifp;
1765 	struct in6_addr *addr;
1766 {
1767 	struct ifaddr *ifa;
1768 
1769 	TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list)
1770 	{
1771 		if (ifa->ifa_addr == NULL)
1772 			continue;	/* just for safety */
1773 		if (ifa->ifa_addr->sa_family != AF_INET6)
1774 			continue;
1775 		if (IN6_ARE_ADDR_EQUAL(addr, IFA_IN6(ifa)))
1776 			break;
1777 	}
1778 
1779 	return((struct in6_ifaddr *)ifa);
1780 }
1781 
1782 /*
1783  * Convert IP6 address to printable (loggable) representation.
1784  */
1785 static char digits[] = "0123456789abcdef";
1786 static int ip6round = 0;
1787 char *
1788 ip6_sprintf(addr)
1789 	const struct in6_addr *addr;
1790 {
1791 	static char ip6buf[8][48];
1792 	int i;
1793 	char *cp;
1794 	u_short *a = (u_short *)addr;
1795 	u_char *d;
1796 	int dcolon = 0;
1797 
1798 	ip6round = (ip6round + 1) & 7;
1799 	cp = ip6buf[ip6round];
1800 
1801 	for (i = 0; i < 8; i++) {
1802 		if (dcolon == 1) {
1803 			if (*a == 0) {
1804 				if (i == 7)
1805 					*cp++ = ':';
1806 				a++;
1807 				continue;
1808 			} else
1809 				dcolon = 2;
1810 		}
1811 		if (*a == 0) {
1812 			if (dcolon == 0 && *(a + 1) == 0) {
1813 				if (i == 0)
1814 					*cp++ = ':';
1815 				*cp++ = ':';
1816 				dcolon = 1;
1817 			} else {
1818 				*cp++ = '0';
1819 				*cp++ = ':';
1820 			}
1821 			a++;
1822 			continue;
1823 		}
1824 		d = (u_char *)a;
1825 		*cp++ = digits[*d >> 4];
1826 		*cp++ = digits[*d++ & 0xf];
1827 		*cp++ = digits[*d >> 4];
1828 		*cp++ = digits[*d & 0xf];
1829 		*cp++ = ':';
1830 		a++;
1831 	}
1832 	*--cp = 0;
1833 	return(ip6buf[ip6round]);
1834 }
1835 
1836 int
1837 in6_localaddr(in6)
1838 	struct in6_addr *in6;
1839 {
1840 	struct in6_ifaddr *ia;
1841 
1842 	if (IN6_IS_ADDR_LOOPBACK(in6) || IN6_IS_ADDR_LINKLOCAL(in6))
1843 		return 1;
1844 
1845 	for (ia = in6_ifaddr; ia; ia = ia->ia_next)
1846 		if (IN6_ARE_MASKED_ADDR_EQUAL(in6, &ia->ia_addr.sin6_addr,
1847 					      &ia->ia_prefixmask.sin6_addr))
1848 			return 1;
1849 
1850 	return (0);
1851 }
1852 
1853 int
1854 in6_is_addr_deprecated(sa6)
1855 	struct sockaddr_in6 *sa6;
1856 {
1857 	struct in6_ifaddr *ia;
1858 
1859 	for (ia = in6_ifaddr; ia; ia = ia->ia_next) {
1860 		if (IN6_ARE_ADDR_EQUAL(&ia->ia_addr.sin6_addr,
1861 				       &sa6->sin6_addr) &&
1862 #ifdef SCOPEDROUTING
1863 		    ia->ia_addr.sin6_scope_id == sa6->sin6_scope_id &&
1864 #endif
1865 		    (ia->ia6_flags & IN6_IFF_DEPRECATED) != 0)
1866 			return(1); /* true */
1867 
1868 		/* XXX: do we still have to go thru the rest of the list? */
1869 	}
1870 
1871 	return(0);		/* false */
1872 }
1873 
1874 /*
1875  * return length of part which dst and src are equal
1876  * hard coding...
1877  */
1878 int
1879 in6_matchlen(src, dst)
1880 struct in6_addr *src, *dst;
1881 {
1882 	int match = 0;
1883 	u_char *s = (u_char *)src, *d = (u_char *)dst;
1884 	u_char *lim = s + 16, r;
1885 
1886 	while (s < lim)
1887 		if ((r = (*d++ ^ *s++)) != 0) {
1888 			while (r < 128) {
1889 				match++;
1890 				r <<= 1;
1891 			}
1892 			break;
1893 		} else
1894 			match += 8;
1895 	return match;
1896 }
1897 
1898 /* XXX: to be scope conscious */
1899 int
1900 in6_are_prefix_equal(p1, p2, len)
1901 	struct in6_addr *p1, *p2;
1902 	int len;
1903 {
1904 	int bytelen, bitlen;
1905 
1906 	/* sanity check */
1907 	if (0 > len || len > 128) {
1908 		log(LOG_ERR, "in6_are_prefix_equal: invalid prefix length(%d)\n",
1909 		    len);
1910 		return(0);
1911 	}
1912 
1913 	bytelen = len / 8;
1914 	bitlen = len % 8;
1915 
1916 	if (bcmp(&p1->s6_addr, &p2->s6_addr, bytelen))
1917 		return(0);
1918 	if (p1->s6_addr[bytelen] >> (8 - bitlen) !=
1919 	    p2->s6_addr[bytelen] >> (8 - bitlen))
1920 		return(0);
1921 
1922 	return(1);
1923 }
1924 
1925 void
1926 in6_prefixlen2mask(maskp, len)
1927 	struct in6_addr *maskp;
1928 	int len;
1929 {
1930 	u_char maskarray[8] = {0x80, 0xc0, 0xe0, 0xf0, 0xf8, 0xfc, 0xfe, 0xff};
1931 	int bytelen, bitlen, i;
1932 
1933 	/* sanity check */
1934 	if (0 > len || len > 128) {
1935 		log(LOG_ERR, "in6_prefixlen2mask: invalid prefix length(%d)\n",
1936 		    len);
1937 		return;
1938 	}
1939 
1940 	bzero(maskp, sizeof(*maskp));
1941 	bytelen = len / 8;
1942 	bitlen = len % 8;
1943 	for (i = 0; i < bytelen; i++)
1944 		maskp->s6_addr[i] = 0xff;
1945 	if (bitlen)
1946 		maskp->s6_addr[bytelen] = maskarray[bitlen - 1];
1947 }
1948 
1949 /*
1950  * return the best address out of the same scope
1951  */
1952 struct in6_ifaddr *
1953 in6_ifawithscope(oifp, dst)
1954 	struct ifnet *oifp;
1955 	struct in6_addr *dst;
1956 {
1957 	int dst_scope =	in6_addrscope(dst), src_scope, best_scope = 0;
1958 	int blen = -1;
1959 	struct ifaddr *ifa;
1960 	struct ifnet *ifp;
1961 	struct in6_ifaddr *ifa_best = NULL;
1962 
1963 	if (oifp == NULL) {
1964 #if 0
1965 		printf("in6_ifawithscope: output interface is not specified\n");
1966 #endif
1967 		return(NULL);
1968 	}
1969 
1970 	/*
1971 	 * We search for all addresses on all interfaces from the beginning.
1972 	 * Comparing an interface with the outgoing interface will be done
1973 	 * only at the final stage of tiebreaking.
1974 	 */
1975 	for (ifp = TAILQ_FIRST(&ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list))
1976 	{
1977 		/*
1978 		 * We can never take an address that breaks the scope zone
1979 		 * of the destination.
1980 		 */
1981 		if (in6_addr2scopeid(ifp, dst) != in6_addr2scopeid(oifp, dst))
1982 			continue;
1983 
1984 		TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list)
1985 		{
1986 			int tlen = -1, dscopecmp, bscopecmp, matchcmp;
1987 
1988 			if (ifa->ifa_addr->sa_family != AF_INET6)
1989 				continue;
1990 
1991 			src_scope = in6_addrscope(IFA_IN6(ifa));
1992 
1993 			/*
1994 			 * Don't use an address before completing DAD
1995 			 * nor a duplicated address.
1996 			 */
1997 			if (((struct in6_ifaddr *)ifa)->ia6_flags &
1998 			    IN6_IFF_NOTREADY)
1999 				continue;
2000 
2001 			/* XXX: is there any case to allow anycasts? */
2002 			if (((struct in6_ifaddr *)ifa)->ia6_flags &
2003 			    IN6_IFF_ANYCAST)
2004 				continue;
2005 
2006 			if (((struct in6_ifaddr *)ifa)->ia6_flags &
2007 			    IN6_IFF_DETACHED)
2008 				continue;
2009 
2010 			/*
2011 			 * If this is the first address we find,
2012 			 * keep it anyway.
2013 			 */
2014 			if (ifa_best == NULL)
2015 				goto replace;
2016 
2017 			/*
2018 			 * ifa_best is never NULL beyond this line except
2019 			 * within the block labeled "replace".
2020 			 */
2021 
2022 			/*
2023 			 * If ifa_best has a smaller scope than dst and
2024 			 * the current address has a larger one than
2025 			 * (or equal to) dst, always replace ifa_best.
2026 			 * Also, if the current address has a smaller scope
2027 			 * than dst, ignore it unless ifa_best also has a
2028 			 * smaller scope.
2029 			 * Consequently, after the two if-clause below,
2030 			 * the followings must be satisfied:
2031 			 * (scope(src) < scope(dst) &&
2032 			 *  scope(best) < scope(dst))
2033 			 *  OR
2034 			 * (scope(best) >= scope(dst) &&
2035 			 *  scope(src) >= scope(dst))
2036 			 */
2037 			if (IN6_ARE_SCOPE_CMP(best_scope, dst_scope) < 0 &&
2038 			    IN6_ARE_SCOPE_CMP(src_scope, dst_scope) >= 0)
2039 				goto replace; /* (A) */
2040 			if (IN6_ARE_SCOPE_CMP(src_scope, dst_scope) < 0 &&
2041 			    IN6_ARE_SCOPE_CMP(best_scope, dst_scope) >= 0)
2042 				continue; /* (B) */
2043 
2044 			/*
2045 			 * A deprecated address SHOULD NOT be used in new
2046 			 * communications if an alternate (non-deprecated)
2047 			 * address is available and has sufficient scope.
2048 			 * RFC 2462, Section 5.5.4.
2049 			 */
2050 			if (((struct in6_ifaddr *)ifa)->ia6_flags &
2051 			    IN6_IFF_DEPRECATED) {
2052 				/*
2053 				 * Ignore any deprecated addresses if
2054 				 * specified by configuration.
2055 				 */
2056 				if (!ip6_use_deprecated)
2057 					continue;
2058 
2059 				/*
2060 				 * If we have already found a non-deprecated
2061 				 * candidate, just ignore deprecated addresses.
2062 				 */
2063 				if ((ifa_best->ia6_flags & IN6_IFF_DEPRECATED)
2064 				    == 0)
2065 					continue;
2066 			}
2067 
2068 			/*
2069 			 * A non-deprecated address is always preferred
2070 			 * to a deprecated one regardless of scopes and
2071 			 * address matching (Note invariants ensured by the
2072 			 * conditions (A) and (B) above.)
2073 			 */
2074 			if ((ifa_best->ia6_flags & IN6_IFF_DEPRECATED) &&
2075 			    (((struct in6_ifaddr *)ifa)->ia6_flags &
2076 			     IN6_IFF_DEPRECATED) == 0)
2077 				goto replace;
2078 
2079 			/*
2080 			 * When we use temporary addresses described in
2081 			 * RFC 3041, we prefer temporary addresses to
2082 			 * public autoconf addresses.  Again, note the
2083 			 * invariants from (A) and (B).  Also note that we
2084 			 * don't have any preference between static addresses
2085 			 * and autoconf addresses (despite of whether or not
2086 			 * the latter is temporary or public.)
2087 			 */
2088 			if (ip6_use_tempaddr) {
2089 				struct in6_ifaddr *ifat;
2090 
2091 				ifat = (struct in6_ifaddr *)ifa;
2092 				if ((ifa_best->ia6_flags &
2093 				     (IN6_IFF_AUTOCONF|IN6_IFF_TEMPORARY))
2094 				     == IN6_IFF_AUTOCONF &&
2095 				    (ifat->ia6_flags &
2096 				     (IN6_IFF_AUTOCONF|IN6_IFF_TEMPORARY))
2097 				     == (IN6_IFF_AUTOCONF|IN6_IFF_TEMPORARY)) {
2098 					goto replace;
2099 				}
2100 				if ((ifa_best->ia6_flags &
2101 				     (IN6_IFF_AUTOCONF|IN6_IFF_TEMPORARY))
2102 				    == (IN6_IFF_AUTOCONF|IN6_IFF_TEMPORARY) &&
2103 				    (ifat->ia6_flags &
2104 				     (IN6_IFF_AUTOCONF|IN6_IFF_TEMPORARY))
2105 				     == IN6_IFF_AUTOCONF) {
2106 					continue;
2107 				}
2108 			}
2109 
2110 			/*
2111 			 * At this point, we have two cases:
2112 			 * 1. we are looking at a non-deprecated address,
2113 			 *    and ifa_best is also non-deprecated.
2114 			 * 2. we are looking at a deprecated address,
2115 			 *    and ifa_best is also deprecated.
2116 			 * Also, we do not have to consider a case where
2117 			 * the scope of if_best is larger(smaller) than dst and
2118 			 * the scope of the current address is smaller(larger)
2119 			 * than dst. Such a case has already been covered.
2120 			 * Tiebreaking is done according to the following
2121 			 * items:
2122 			 * - the scope comparison between the address and
2123 			 *   dst (dscopecmp)
2124 			 * - the scope comparison between the address and
2125 			 *   ifa_best (bscopecmp)
2126 			 * - if the address match dst longer than ifa_best
2127 			 *   (matchcmp)
2128 			 * - if the address is on the outgoing I/F (outI/F)
2129 			 *
2130 			 * Roughly speaking, the selection policy is
2131 			 * - the most important item is scope. The same scope
2132 			 *   is best. Then search for a larger scope.
2133 			 *   Smaller scopes are the last resort.
2134 			 * - A deprecated address is chosen only when we have
2135 			 *   no address that has an enough scope, but is
2136 			 *   prefered to any addresses of smaller scopes
2137 			 *   (this must be already done above.)
2138 			 * - addresses on the outgoing I/F are preferred to
2139 			 *   ones on other interfaces if none of above
2140 			 *   tiebreaks.  In the table below, the column "bI"
2141 			 *   means if the best_ifa is on the outgoing
2142 			 *   interface, and the column "sI" means if the ifa
2143 			 *   is on the outgoing interface.
2144 			 * - If there is no other reasons to choose one,
2145 			 *   longest address match against dst is considered.
2146 			 *
2147 			 * The precise decision table is as follows:
2148 			 * dscopecmp bscopecmp    match  bI oI | replace?
2149 			 *       N/A     equal      N/A   Y  N |   No (1)
2150 			 *       N/A     equal      N/A   N  Y |  Yes (2)
2151 			 *       N/A     equal   larger    N/A |  Yes (3)
2152 			 *       N/A     equal  !larger    N/A |   No (4)
2153 			 *    larger    larger      N/A    N/A |   No (5)
2154 			 *    larger   smaller      N/A    N/A |  Yes (6)
2155 			 *   smaller    larger      N/A    N/A |  Yes (7)
2156 			 *   smaller   smaller      N/A    N/A |   No (8)
2157 			 *     equal   smaller      N/A    N/A |  Yes (9)
2158 			 *     equal    larger       (already done at A above)
2159 			 */
2160 			dscopecmp = IN6_ARE_SCOPE_CMP(src_scope, dst_scope);
2161 			bscopecmp = IN6_ARE_SCOPE_CMP(src_scope, best_scope);
2162 
2163 			if (bscopecmp == 0) {
2164 				struct ifnet *bifp = ifa_best->ia_ifp;
2165 
2166 				if (bifp == oifp && ifp != oifp) /* (1) */
2167 					continue;
2168 				if (bifp != oifp && ifp == oifp) /* (2) */
2169 					goto replace;
2170 
2171 				/*
2172 				 * Both bifp and ifp are on the outgoing
2173 				 * interface, or both two are on a different
2174 				 * interface from the outgoing I/F.
2175 				 * now we need address matching against dst
2176 				 * for tiebreaking.
2177 				 */
2178 				tlen = in6_matchlen(IFA_IN6(ifa), dst);
2179 				matchcmp = tlen - blen;
2180 				if (matchcmp > 0) /* (3) */
2181 					goto replace;
2182 				continue; /* (4) */
2183 			}
2184 			if (dscopecmp > 0) {
2185 				if (bscopecmp > 0) /* (5) */
2186 					continue;
2187 				goto replace; /* (6) */
2188 			}
2189 			if (dscopecmp < 0) {
2190 				if (bscopecmp > 0) /* (7) */
2191 					goto replace;
2192 				continue; /* (8) */
2193 			}
2194 
2195 			/* now dscopecmp must be 0 */
2196 			if (bscopecmp < 0)
2197 				goto replace; /* (9) */
2198 
2199 		  replace:
2200 			ifa_best = (struct in6_ifaddr *)ifa;
2201 			blen = tlen >= 0 ? tlen :
2202 				in6_matchlen(IFA_IN6(ifa), dst);
2203 			best_scope = in6_addrscope(&ifa_best->ia_addr.sin6_addr);
2204 		}
2205 	}
2206 
2207 	/* count statistics for future improvements */
2208 	if (ifa_best == NULL)
2209 		ip6stat.ip6s_sources_none++;
2210 	else {
2211 		if (oifp == ifa_best->ia_ifp)
2212 			ip6stat.ip6s_sources_sameif[best_scope]++;
2213 		else
2214 			ip6stat.ip6s_sources_otherif[best_scope]++;
2215 
2216 		if (best_scope == dst_scope)
2217 			ip6stat.ip6s_sources_samescope[best_scope]++;
2218 		else
2219 			ip6stat.ip6s_sources_otherscope[best_scope]++;
2220 
2221 		if ((ifa_best->ia6_flags & IN6_IFF_DEPRECATED) != 0)
2222 			ip6stat.ip6s_sources_deprecated[best_scope]++;
2223 	}
2224 
2225 	return(ifa_best);
2226 }
2227 
2228 /*
2229  * return the best address out of the same scope. if no address was
2230  * found, return the first valid address from designated IF.
2231  */
2232 struct in6_ifaddr *
2233 in6_ifawithifp(ifp, dst)
2234 	struct ifnet *ifp;
2235 	struct in6_addr *dst;
2236 {
2237 	int dst_scope =	in6_addrscope(dst), blen = -1, tlen;
2238 	struct ifaddr *ifa;
2239 	struct in6_ifaddr *besta = 0;
2240 	struct in6_ifaddr *dep[2];	/*last-resort: deprecated*/
2241 
2242 	dep[0] = dep[1] = NULL;
2243 
2244 	/*
2245 	 * We first look for addresses in the same scope.
2246 	 * If there is one, return it.
2247 	 * If two or more, return one which matches the dst longest.
2248 	 * If none, return one of global addresses assigned other ifs.
2249 	 */
2250 	TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list)
2251 	{
2252 		if (ifa->ifa_addr->sa_family != AF_INET6)
2253 			continue;
2254 		if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST)
2255 			continue; /* XXX: is there any case to allow anycast? */
2256 		if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_NOTREADY)
2257 			continue; /* don't use this interface */
2258 		if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DETACHED)
2259 			continue;
2260 		if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DEPRECATED) {
2261 			if (ip6_use_deprecated)
2262 				dep[0] = (struct in6_ifaddr *)ifa;
2263 			continue;
2264 		}
2265 
2266 		if (dst_scope == in6_addrscope(IFA_IN6(ifa))) {
2267 			/*
2268 			 * call in6_matchlen() as few as possible
2269 			 */
2270 			if (besta) {
2271 				if (blen == -1)
2272 					blen = in6_matchlen(&besta->ia_addr.sin6_addr, dst);
2273 				tlen = in6_matchlen(IFA_IN6(ifa), dst);
2274 				if (tlen > blen) {
2275 					blen = tlen;
2276 					besta = (struct in6_ifaddr *)ifa;
2277 				}
2278 			} else
2279 				besta = (struct in6_ifaddr *)ifa;
2280 		}
2281 	}
2282 	if (besta)
2283 		return(besta);
2284 
2285 	TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list)
2286 	{
2287 		if (ifa->ifa_addr->sa_family != AF_INET6)
2288 			continue;
2289 		if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST)
2290 			continue; /* XXX: is there any case to allow anycast? */
2291 		if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_NOTREADY)
2292 			continue; /* don't use this interface */
2293 		if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DETACHED)
2294 			continue;
2295 		if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DEPRECATED) {
2296 			if (ip6_use_deprecated)
2297 				dep[1] = (struct in6_ifaddr *)ifa;
2298 			continue;
2299 		}
2300 
2301 		return (struct in6_ifaddr *)ifa;
2302 	}
2303 
2304 	/* use the last-resort values, that are, deprecated addresses */
2305 	if (dep[0])
2306 		return dep[0];
2307 	if (dep[1])
2308 		return dep[1];
2309 
2310 	return NULL;
2311 }
2312 
2313 /*
2314  * perform DAD when interface becomes IFF_UP.
2315  */
2316 void
2317 in6_if_up(ifp)
2318 	struct ifnet *ifp;
2319 {
2320 	struct ifaddr *ifa;
2321 	struct in6_ifaddr *ia;
2322 	int dad_delay;		/* delay ticks before DAD output */
2323 
2324 	/*
2325 	 * special cases, like 6to4, are handled in in6_ifattach
2326 	 */
2327 	in6_ifattach(ifp, NULL);
2328 
2329 	dad_delay = 0;
2330 	TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list)
2331 	{
2332 		if (ifa->ifa_addr->sa_family != AF_INET6)
2333 			continue;
2334 		ia = (struct in6_ifaddr *)ifa;
2335 		if (ia->ia6_flags & IN6_IFF_TENTATIVE)
2336 			nd6_dad_start(ifa, &dad_delay);
2337 	}
2338 }
2339 
2340 int
2341 in6if_do_dad(ifp)
2342 	struct ifnet *ifp;
2343 {
2344 	if ((ifp->if_flags & IFF_LOOPBACK) != 0)
2345 		return(0);
2346 
2347 	switch (ifp->if_type) {
2348 #ifdef IFT_DUMMY
2349 	case IFT_DUMMY:
2350 #endif
2351 	case IFT_FAITH:
2352 		/*
2353 		 * These interfaces do not have the IFF_LOOPBACK flag,
2354 		 * but loop packets back.  We do not have to do DAD on such
2355 		 * interfaces.  We should even omit it, because loop-backed
2356 		 * NS would confuse the DAD procedure.
2357 		 */
2358 		return(0);
2359 	default:
2360 		/*
2361 		 * Our DAD routine requires the interface up and running.
2362 		 * However, some interfaces can be up before the RUNNING
2363 		 * status.  Additionaly, users may try to assign addresses
2364 		 * before the interface becomes up (or running).
2365 		 * We simply skip DAD in such a case as a work around.
2366 		 * XXX: we should rather mark "tentative" on such addresses,
2367 		 * and do DAD after the interface becomes ready.
2368 		 */
2369 		if ((ifp->if_flags & (IFF_UP|IFF_RUNNING)) !=
2370 		    (IFF_UP|IFF_RUNNING))
2371 			return(0);
2372 
2373 		return(1);
2374 	}
2375 }
2376 
2377 /*
2378  * Calculate max IPv6 MTU through all the interfaces and store it
2379  * to in6_maxmtu.
2380  */
2381 void
2382 in6_setmaxmtu()
2383 {
2384 	unsigned long maxmtu = 0;
2385 	struct ifnet *ifp;
2386 
2387 	for (ifp = TAILQ_FIRST(&ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list))
2388 	{
2389 		if ((ifp->if_flags & IFF_LOOPBACK) == 0 &&
2390 		    nd_ifinfo[ifp->if_index].linkmtu > maxmtu)
2391 			maxmtu =  nd_ifinfo[ifp->if_index].linkmtu;
2392 	}
2393 	if (maxmtu)	/* update only when maxmtu is positive */
2394 		in6_maxmtu = maxmtu;
2395 }
2396 
2397 /*
2398  * Convert sockaddr_in6 to sockaddr_in. Original sockaddr_in6 must be
2399  * v4 mapped addr or v4 compat addr
2400  */
2401 void
2402 in6_sin6_2_sin(struct sockaddr_in *sin, struct sockaddr_in6 *sin6)
2403 {
2404 	bzero(sin, sizeof(*sin));
2405 	sin->sin_len = sizeof(struct sockaddr_in);
2406 	sin->sin_family = AF_INET;
2407 	sin->sin_port = sin6->sin6_port;
2408 	sin->sin_addr.s_addr = sin6->sin6_addr.s6_addr32[3];
2409 }
2410 
2411 /* Convert sockaddr_in to sockaddr_in6 in v4 mapped addr format. */
2412 void
2413 in6_sin_2_v4mapsin6(struct sockaddr_in *sin, struct sockaddr_in6 *sin6)
2414 {
2415 	bzero(sin6, sizeof(*sin6));
2416 	sin6->sin6_len = sizeof(struct sockaddr_in6);
2417 	sin6->sin6_family = AF_INET6;
2418 	sin6->sin6_port = sin->sin_port;
2419 	sin6->sin6_addr.s6_addr32[0] = 0;
2420 	sin6->sin6_addr.s6_addr32[1] = 0;
2421 	sin6->sin6_addr.s6_addr32[2] = IPV6_ADDR_INT32_SMP;
2422 	sin6->sin6_addr.s6_addr32[3] = sin->sin_addr.s_addr;
2423 }
2424 
2425 /* Convert sockaddr_in6 into sockaddr_in. */
2426 void
2427 in6_sin6_2_sin_in_sock(struct sockaddr *nam)
2428 {
2429 	struct sockaddr_in *sin_p;
2430 	struct sockaddr_in6 sin6;
2431 
2432 	/*
2433 	 * Save original sockaddr_in6 addr and convert it
2434 	 * to sockaddr_in.
2435 	 */
2436 	sin6 = *(struct sockaddr_in6 *)nam;
2437 	sin_p = (struct sockaddr_in *)nam;
2438 	in6_sin6_2_sin(sin_p, &sin6);
2439 }
2440 
2441 /* Convert sockaddr_in into sockaddr_in6 in v4 mapped addr format. */
2442 void
2443 in6_sin_2_v4mapsin6_in_sock(struct sockaddr **nam)
2444 {
2445 	struct sockaddr_in *sin_p;
2446 	struct sockaddr_in6 *sin6_p;
2447 
2448 	MALLOC(sin6_p, struct sockaddr_in6 *, sizeof *sin6_p, M_SONAME,
2449 	       M_WAITOK);
2450 	sin_p = (struct sockaddr_in *)*nam;
2451 	in6_sin_2_v4mapsin6(sin_p, sin6_p);
2452 	FREE(*nam, M_SONAME);
2453 	*nam = (struct sockaddr *)sin6_p;
2454 }
2455