xref: /freebsd/sys/netinet6/in6.c (revision 6990ffd8a95caaba6858ad44ff1b3157d1efba8f)
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 /*
142  * Subroutine for in6_ifaddloop() and in6_ifremloop().
143  * This routine does actual work.
144  */
145 static void
146 in6_ifloop_request(int cmd, struct ifaddr *ifa)
147 {
148 	struct sockaddr_in6 all1_sa;
149 	struct rtentry *nrt = NULL;
150 	int e;
151 
152 	bzero(&all1_sa, sizeof(all1_sa));
153 	all1_sa.sin6_family = AF_INET6;
154 	all1_sa.sin6_len = sizeof(struct sockaddr_in6);
155 	all1_sa.sin6_addr = in6mask128;
156 
157 	/*
158 	 * We specify the address itself as the gateway, and set the
159 	 * RTF_LLINFO flag, so that the corresponding host route would have
160 	 * the flag, and thus applications that assume traditional behavior
161 	 * would be happy.  Note that we assume the caller of the function
162 	 * (probably implicitly) set nd6_rtrequest() to ifa->ifa_rtrequest,
163 	 * which changes the outgoing interface to the loopback interface.
164 	 */
165 	e = rtrequest(cmd, ifa->ifa_addr, ifa->ifa_addr,
166 		      (struct sockaddr *)&all1_sa,
167 		      RTF_UP|RTF_HOST|RTF_LLINFO, &nrt);
168 	if (e != 0) {
169 		log(LOG_ERR, "in6_ifloop_request: "
170 		    "%s operation failed for %s (errno=%d)\n",
171 		    cmd == RTM_ADD ? "ADD" : "DELETE",
172 		    ip6_sprintf(&((struct in6_ifaddr *)ifa)->ia_addr.sin6_addr),
173 		    e);
174 	}
175 
176 	/*
177 	 * Make sure rt_ifa be equal to IFA, the second argument of the
178 	 * function.
179 	 * We need this because when we refer to rt_ifa->ia6_flags in
180 	 * ip6_input, we assume that the rt_ifa points to the address instead
181 	 * of the loopback address.
182 	 */
183 	if (cmd == RTM_ADD && nrt && ifa != nrt->rt_ifa) {
184 		IFAFREE(nrt->rt_ifa);
185 		IFAREF(ifa);
186 		nrt->rt_ifa = ifa;
187 	}
188 
189 	/*
190 	 * Report the addition/removal of the address to the routing socket.
191 	 * XXX: since we called rtinit for a p2p interface with a destination,
192 	 *      we end up reporting twice in such a case.  Should we rather
193 	 *      omit the second report?
194 	 */
195 	if (nrt) {
196 		rt_newaddrmsg(cmd, ifa, e, nrt);
197 		if (cmd == RTM_DELETE) {
198 			if (nrt->rt_refcnt <= 0) {
199 				/* XXX: we should free the entry ourselves. */
200 				nrt->rt_refcnt++;
201 				rtfree(nrt);
202 			}
203 		} else {
204 			/* the cmd must be RTM_ADD here */
205 			nrt->rt_refcnt--;
206 		}
207 	}
208 }
209 
210 /*
211  * Add ownaddr as loopback rtentry.  We previously add the route only if
212  * necessary (ex. on a p2p link).  However, since we now manage addresses
213  * separately from prefixes, we should always add the route.  We can't
214  * rely on the cloning mechanism from the corresponding interface route
215  * any more.
216  */
217 static void
218 in6_ifaddloop(struct ifaddr *ifa)
219 {
220 	struct rtentry *rt;
221 
222 	/* If there is no loopback entry, allocate one. */
223 	rt = rtalloc1(ifa->ifa_addr, 0, 0);
224 	if (rt == NULL || (rt->rt_flags & RTF_HOST) == 0 ||
225 	    (rt->rt_ifp->if_flags & IFF_LOOPBACK) == 0)
226 		in6_ifloop_request(RTM_ADD, ifa);
227 	if (rt)
228 		rt->rt_refcnt--;
229 }
230 
231 /*
232  * Remove loopback rtentry of ownaddr generated by in6_ifaddloop(),
233  * if it exists.
234  */
235 static void
236 in6_ifremloop(struct ifaddr *ifa)
237 {
238 	struct in6_ifaddr *ia;
239 	struct rtentry *rt;
240 	int ia_count = 0;
241 
242 	/*
243 	 * Some of BSD variants do not remove cloned routes
244 	 * from an interface direct route, when removing the direct route
245 	 * (see comments in net/net_osdep.h).  Even for variants that do remove
246 	 * cloned routes, they could fail to remove the cloned routes when
247 	 * we handle multple addresses that share a common prefix.
248 	 * So, we should remove the route corresponding to the deleted address
249 	 * regardless of the result of in6_is_ifloop_auto().
250 	 */
251 
252 	/*
253 	 * Delete the entry only if exact one ifa exists. More than one ifa
254 	 * can exist if we assign a same single address to multiple
255 	 * (probably p2p) interfaces.
256 	 * XXX: we should avoid such a configuration in IPv6...
257 	 */
258 	for (ia = in6_ifaddr; ia; ia = ia->ia_next) {
259 		if (IN6_ARE_ADDR_EQUAL(IFA_IN6(ifa), &ia->ia_addr.sin6_addr)) {
260 			ia_count++;
261 			if (ia_count > 1)
262 				break;
263 		}
264 	}
265 
266 	if (ia_count == 1) {
267 		/*
268 		 * Before deleting, check if a corresponding loopbacked host
269 		 * route surely exists. With this check, we can avoid to
270 		 * delete an interface direct route whose destination is same
271 		 * as the address being removed. This can happen when remofing
272 		 * a subnet-router anycast address on an interface attahced
273 		 * to a shared medium.
274 		 */
275 		rt = rtalloc1(ifa->ifa_addr, 0, 0);
276 		if (rt != NULL && (rt->rt_flags & RTF_HOST) != 0 &&
277 		    (rt->rt_ifp->if_flags & IFF_LOOPBACK) != 0) {
278 			rt->rt_refcnt--;
279 			in6_ifloop_request(RTM_DELETE, ifa);
280 		}
281 	}
282 }
283 
284 int
285 in6_ifindex2scopeid(idx)
286 	int idx;
287 {
288 	struct ifnet *ifp;
289 	struct ifaddr *ifa;
290 	struct sockaddr_in6 *sin6;
291 
292 	if (idx < 0 || if_index < idx)
293 		return -1;
294 	ifp = ifnet_byindex(idx);
295 
296 	TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list)
297 	{
298 		if (ifa->ifa_addr->sa_family != AF_INET6)
299 			continue;
300 		sin6 = (struct sockaddr_in6 *)ifa->ifa_addr;
301 		if (IN6_IS_ADDR_SITELOCAL(&sin6->sin6_addr))
302 			return sin6->sin6_scope_id & 0xffff;
303 	}
304 
305 	return -1;
306 }
307 
308 int
309 in6_mask2len(mask, lim0)
310 	struct in6_addr *mask;
311 	u_char *lim0;
312 {
313 	int x = 0, y;
314 	u_char *lim = lim0, *p;
315 
316 	if (lim0 == NULL ||
317 	    lim0 - (u_char *)mask > sizeof(*mask)) /* ignore the scope_id part */
318 		lim = (u_char *)mask + sizeof(*mask);
319 	for (p = (u_char *)mask; p < lim; x++, p++) {
320 		if (*p != 0xff)
321 			break;
322 	}
323 	y = 0;
324 	if (p < lim) {
325 		for (y = 0; y < 8; y++) {
326 			if ((*p & (0x80 >> y)) == 0)
327 				break;
328 		}
329 	}
330 
331 	/*
332 	 * when the limit pointer is given, do a stricter check on the
333 	 * remaining bits.
334 	 */
335 	if (p < lim) {
336 		if (y != 0 && (*p & (0x00ff >> y)) != 0)
337 			return(-1);
338 		for (p = p + 1; p < lim; p++)
339 			if (*p != 0)
340 				return(-1);
341 	}
342 
343 	return x * 8 + y;
344 }
345 
346 void
347 in6_len2mask(mask, len)
348 	struct in6_addr *mask;
349 	int len;
350 {
351 	int i;
352 
353 	bzero(mask, sizeof(*mask));
354 	for (i = 0; i < len / 8; i++)
355 		mask->s6_addr8[i] = 0xff;
356 	if (len % 8)
357 		mask->s6_addr8[i] = (0xff00 >> (len % 8)) & 0xff;
358 }
359 
360 #define ifa2ia6(ifa)	((struct in6_ifaddr *)(ifa))
361 #define ia62ifa(ia6)	(&((ia6)->ia_ifa))
362 
363 int
364 in6_control(so, cmd, data, ifp, td)
365 	struct	socket *so;
366 	u_long cmd;
367 	caddr_t	data;
368 	struct ifnet *ifp;
369 	struct thread *td;
370 {
371 	struct	in6_ifreq *ifr = (struct in6_ifreq *)data;
372 	struct	in6_ifaddr *ia = NULL;
373 	struct	in6_aliasreq *ifra = (struct in6_aliasreq *)data;
374 	int privileged;
375 
376 	privileged = 0;
377 	if (td == NULL || !suser_td(td))
378 		privileged++;
379 
380 	switch (cmd) {
381 	case SIOCGETSGCNT_IN6:
382 	case SIOCGETMIFCNT_IN6:
383 		return (mrt6_ioctl(cmd, data));
384 	}
385 
386 	if (ifp == NULL)
387 		return(EOPNOTSUPP);
388 
389 	switch (cmd) {
390 	case SIOCSNDFLUSH_IN6:
391 	case SIOCSPFXFLUSH_IN6:
392 	case SIOCSRTRFLUSH_IN6:
393 	case SIOCSDEFIFACE_IN6:
394 	case SIOCSIFINFO_FLAGS:
395 		if (!privileged)
396 			return(EPERM);
397 		/*fall through*/
398 	case OSIOCGIFINFO_IN6:
399 	case SIOCGIFINFO_IN6:
400 	case SIOCGDRLST_IN6:
401 	case SIOCGPRLST_IN6:
402 	case SIOCGNBRINFO_IN6:
403 	case SIOCGDEFIFACE_IN6:
404 		return(nd6_ioctl(cmd, data, ifp));
405 	}
406 
407 	switch (cmd) {
408 	case SIOCSIFPREFIX_IN6:
409 	case SIOCDIFPREFIX_IN6:
410 	case SIOCAIFPREFIX_IN6:
411 	case SIOCCIFPREFIX_IN6:
412 	case SIOCSGIFPREFIX_IN6:
413 	case SIOCGIFPREFIX_IN6:
414 		log(LOG_NOTICE,
415 		    "prefix ioctls are now invalidated. "
416 		    "please use ifconfig.\n");
417 		return(EOPNOTSUPP);
418 	}
419 
420 	switch(cmd) {
421 	case SIOCSSCOPE6:
422 		if (!privileged)
423 			return(EPERM);
424 		return(scope6_set(ifp, ifr->ifr_ifru.ifru_scope_id));
425 		break;
426 	case SIOCGSCOPE6:
427 		return(scope6_get(ifp, ifr->ifr_ifru.ifru_scope_id));
428 		break;
429 	case SIOCGSCOPE6DEF:
430 		return(scope6_get_default(ifr->ifr_ifru.ifru_scope_id));
431 		break;
432 	}
433 
434 	switch (cmd) {
435 	case SIOCALIFADDR:
436 	case SIOCDLIFADDR:
437 		if (!privileged)
438 			return(EPERM);
439 		/*fall through*/
440 	case SIOCGLIFADDR:
441 		return in6_lifaddr_ioctl(so, cmd, data, ifp, td);
442 	}
443 
444 	/*
445 	 * Find address for this interface, if it exists.
446 	 */
447 	if (ifra->ifra_addr.sin6_family == AF_INET6) { /* XXX */
448 		struct sockaddr_in6 *sa6 =
449 			(struct sockaddr_in6 *)&ifra->ifra_addr;
450 
451 		if (IN6_IS_ADDR_LINKLOCAL(&sa6->sin6_addr)) {
452 			if (sa6->sin6_addr.s6_addr16[1] == 0) {
453 				/* link ID is not embedded by the user */
454 				sa6->sin6_addr.s6_addr16[1] =
455 					htons(ifp->if_index);
456 			} else if (sa6->sin6_addr.s6_addr16[1] !=
457 				    htons(ifp->if_index)) {
458 				return(EINVAL);	/* link ID contradicts */
459 			}
460 			if (sa6->sin6_scope_id) {
461 				if (sa6->sin6_scope_id !=
462 				    (u_int32_t)ifp->if_index)
463 					return(EINVAL);
464 				sa6->sin6_scope_id = 0; /* XXX: good way? */
465 			}
466 		}
467 		ia = in6ifa_ifpwithaddr(ifp, &ifra->ifra_addr.sin6_addr);
468 	}
469 
470 	switch (cmd) {
471 	case SIOCSIFADDR_IN6:
472 	case SIOCSIFDSTADDR_IN6:
473 	case SIOCSIFNETMASK_IN6:
474 		/*
475 		 * Since IPv6 allows a node to assign multiple addresses
476 		 * on a single interface, SIOCSIFxxx ioctls are not suitable
477 		 * and should be unused.
478 		 */
479 		/* we decided to obsolete this command (20000704) */
480 		return(EINVAL);
481 
482 	case SIOCDIFADDR_IN6:
483 		/*
484 		 * for IPv4, we look for existing in_ifaddr here to allow
485 		 * "ifconfig if0 delete" to remove first IPv4 address on the
486 		 * interface.  For IPv6, as the spec allow multiple interface
487 		 * address from the day one, we consider "remove the first one"
488 		 * semantics to be not preferable.
489 		 */
490 		if (ia == NULL)
491 			return(EADDRNOTAVAIL);
492 		/* FALLTHROUGH */
493 	case SIOCAIFADDR_IN6:
494 		/*
495 		 * We always require users to specify a valid IPv6 address for
496 		 * the corresponding operation.
497 		 */
498 		if (ifra->ifra_addr.sin6_family != AF_INET6 ||
499 		    ifra->ifra_addr.sin6_len != sizeof(struct sockaddr_in6))
500 			return(EAFNOSUPPORT);
501 		if (!privileged)
502 			return(EPERM);
503 
504 		break;
505 
506 	case SIOCGIFADDR_IN6:
507 		/* This interface is basically deprecated. use SIOCGIFCONF. */
508 		/* fall through */
509 	case SIOCGIFAFLAG_IN6:
510 	case SIOCGIFNETMASK_IN6:
511 	case SIOCGIFDSTADDR_IN6:
512 	case SIOCGIFALIFETIME_IN6:
513 		/* must think again about its semantics */
514 		if (ia == NULL)
515 			return(EADDRNOTAVAIL);
516 		break;
517 	case SIOCSIFALIFETIME_IN6:
518 	    {
519 		struct in6_addrlifetime *lt;
520 
521 		if (!privileged)
522 			return(EPERM);
523 		if (ia == NULL)
524 			return(EADDRNOTAVAIL);
525 		/* sanity for overflow - beware unsigned */
526 		lt = &ifr->ifr_ifru.ifru_lifetime;
527 		if (lt->ia6t_vltime != ND6_INFINITE_LIFETIME
528 		 && lt->ia6t_vltime + time_second < time_second) {
529 			return EINVAL;
530 		}
531 		if (lt->ia6t_pltime != ND6_INFINITE_LIFETIME
532 		 && lt->ia6t_pltime + time_second < time_second) {
533 			return EINVAL;
534 		}
535 		break;
536 	    }
537 	}
538 
539 	switch (cmd) {
540 
541 	case SIOCGIFADDR_IN6:
542 		ifr->ifr_addr = ia->ia_addr;
543 		break;
544 
545 	case SIOCGIFDSTADDR_IN6:
546 		if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
547 			return(EINVAL);
548 		/*
549 		 * XXX: should we check if ifa_dstaddr is NULL and return
550 		 * an error?
551 		 */
552 		ifr->ifr_dstaddr = ia->ia_dstaddr;
553 		break;
554 
555 	case SIOCGIFNETMASK_IN6:
556 		ifr->ifr_addr = ia->ia_prefixmask;
557 		break;
558 
559 	case SIOCGIFAFLAG_IN6:
560 		ifr->ifr_ifru.ifru_flags6 = ia->ia6_flags;
561 		break;
562 
563 	case SIOCGIFSTAT_IN6:
564 		if (ifp == NULL)
565 			return EINVAL;
566 		if (in6_ifstat == NULL || ifp->if_index >= in6_ifstatmax
567 		 || in6_ifstat[ifp->if_index] == NULL) {
568 			/* return EAFNOSUPPORT? */
569 			bzero(&ifr->ifr_ifru.ifru_stat,
570 				sizeof(ifr->ifr_ifru.ifru_stat));
571 		} else
572 			ifr->ifr_ifru.ifru_stat = *in6_ifstat[ifp->if_index];
573 		break;
574 
575 	case SIOCGIFSTAT_ICMP6:
576 		if (ifp == NULL)
577 			return EINVAL;
578 		if (icmp6_ifstat == NULL || ifp->if_index >= icmp6_ifstatmax ||
579 		    icmp6_ifstat[ifp->if_index] == NULL) {
580 			/* return EAFNOSUPPORT? */
581 			bzero(&ifr->ifr_ifru.ifru_stat,
582 				sizeof(ifr->ifr_ifru.ifru_icmp6stat));
583 		} else
584 			ifr->ifr_ifru.ifru_icmp6stat =
585 				*icmp6_ifstat[ifp->if_index];
586 		break;
587 
588 	case SIOCGIFALIFETIME_IN6:
589 		ifr->ifr_ifru.ifru_lifetime = ia->ia6_lifetime;
590 		break;
591 
592 	case SIOCSIFALIFETIME_IN6:
593 		ia->ia6_lifetime = ifr->ifr_ifru.ifru_lifetime;
594 		/* for sanity */
595 		if (ia->ia6_lifetime.ia6t_vltime != ND6_INFINITE_LIFETIME) {
596 			ia->ia6_lifetime.ia6t_expire =
597 				time_second + ia->ia6_lifetime.ia6t_vltime;
598 		} else
599 			ia->ia6_lifetime.ia6t_expire = 0;
600 		if (ia->ia6_lifetime.ia6t_pltime != ND6_INFINITE_LIFETIME) {
601 			ia->ia6_lifetime.ia6t_preferred =
602 				time_second + ia->ia6_lifetime.ia6t_pltime;
603 		} else
604 			ia->ia6_lifetime.ia6t_preferred = 0;
605 		break;
606 
607 	case SIOCAIFADDR_IN6:
608 	{
609 		int i, error = 0;
610 		struct nd_prefix pr0, *pr;
611 
612 		/*
613 		 * first, make or update the interface address structure,
614 		 * and link it to the list.
615 		 */
616 		if ((error = in6_update_ifa(ifp, ifra, ia)) != 0)
617 			return(error);
618 
619 		/*
620 		 * then, make the prefix on-link on the interface.
621 		 * XXX: we'd rather create the prefix before the address, but
622 		 * we need at least one address to install the corresponding
623 		 * interface route, so we configure the address first.
624 		 */
625 
626 		/*
627 		 * convert mask to prefix length (prefixmask has already
628 		 * been validated in in6_update_ifa().
629 		 */
630 		bzero(&pr0, sizeof(pr0));
631 		pr0.ndpr_ifp = ifp;
632 		pr0.ndpr_plen = in6_mask2len(&ifra->ifra_prefixmask.sin6_addr,
633 					     NULL);
634 		if (pr0.ndpr_plen == 128)
635 			break;	/* we don't need to install a host route. */
636 		pr0.ndpr_prefix = ifra->ifra_addr;
637 		pr0.ndpr_mask = ifra->ifra_prefixmask.sin6_addr;
638 		/* apply the mask for safety. */
639 		for (i = 0; i < 4; i++) {
640 			pr0.ndpr_prefix.sin6_addr.s6_addr32[i] &=
641 				ifra->ifra_prefixmask.sin6_addr.s6_addr32[i];
642 		}
643 		/*
644 		 * XXX: since we don't have enough APIs, we just set inifinity
645 		 * to lifetimes.  They can be overridden by later advertised
646 		 * RAs (when accept_rtadv is non 0), but we'd rather intend
647 		 * such a behavior.
648 		 */
649 		pr0.ndpr_raf_onlink = 1; /* should be configurable? */
650 		pr0.ndpr_raf_auto =
651 			((ifra->ifra_flags & IN6_IFF_AUTOCONF) != 0);
652 		pr0.ndpr_vltime = ifra->ifra_lifetime.ia6t_vltime;
653 		pr0.ndpr_pltime = ifra->ifra_lifetime.ia6t_pltime;
654 
655 		/* add the prefix if there's one. */
656 		if ((pr = nd6_prefix_lookup(&pr0)) == NULL) {
657 			/*
658 			 * nd6_prelist_add will install the corresponding
659 			 * interface route.
660 			 */
661 			if ((error = nd6_prelist_add(&pr0, NULL, &pr)) != 0)
662 				return(error);
663 			if (pr == NULL) {
664 				log(LOG_ERR, "nd6_prelist_add succedded but "
665 				    "no prefix\n");
666 				return(EINVAL); /* XXX panic here? */
667 			}
668 		}
669 		if ((ia = in6ifa_ifpwithaddr(ifp, &ifra->ifra_addr.sin6_addr))
670 		    == NULL) {
671 		    	/* XXX: this should not happen! */
672 			log(LOG_ERR, "in6_control: addition succeeded, but"
673 			    " no ifaddr\n");
674 		} else {
675 			if ((ia->ia6_flags & IN6_IFF_AUTOCONF) != 0 &&
676 			    ia->ia6_ndpr == NULL) { /* new autoconfed addr */
677 				ia->ia6_ndpr = pr;
678 				pr->ndpr_refcnt++;
679 
680 				/*
681 				 * If this is the first autoconf address from
682 				 * the prefix, create a temporary address
683 				 * as well (when specified).
684 				 */
685 				if (ip6_use_tempaddr &&
686 				    pr->ndpr_refcnt == 1) {
687 					int e;
688 					if ((e = in6_tmpifadd(ia, 1)) != 0) {
689 						log(LOG_NOTICE, "in6_control: "
690 						    "failed to create a "
691 						    "temporary address, "
692 						    "errno=%d\n",
693 						    e);
694 					}
695 				}
696 			}
697 
698 			/*
699 			 * this might affect the status of autoconfigured
700 			 * addresses, that is, this address might make
701 			 * other addresses detached.
702 			 */
703 			pfxlist_onlink_check();
704 		}
705 		break;
706 	}
707 
708 	case SIOCDIFADDR_IN6:
709 	{
710 		int i = 0;
711 		struct nd_prefix pr0, *pr;
712 
713 		/*
714 		 * If the address being deleted is the only one that owns
715 		 * the corresponding prefix, expire the prefix as well.
716 		 * XXX: theoretically, we don't have to warry about such
717 		 * relationship, since we separate the address management
718 		 * and the prefix management.  We do this, however, to provide
719 		 * as much backward compatibility as possible in terms of
720 		 * the ioctl operation.
721 		 */
722 		bzero(&pr0, sizeof(pr0));
723 		pr0.ndpr_ifp = ifp;
724 		pr0.ndpr_plen = in6_mask2len(&ia->ia_prefixmask.sin6_addr,
725 					     NULL);
726 		if (pr0.ndpr_plen == 128)
727 			goto purgeaddr;
728 		pr0.ndpr_prefix = ia->ia_addr;
729 		pr0.ndpr_mask = ia->ia_prefixmask.sin6_addr;
730 		for (i = 0; i < 4; i++) {
731 			pr0.ndpr_prefix.sin6_addr.s6_addr32[i] &=
732 				ia->ia_prefixmask.sin6_addr.s6_addr32[i];
733 		}
734 		/*
735 		 * The logic of the following condition is a bit complicated.
736 		 * We expire the prefix when
737 		 * 1. the address obeys autoconfiguration and it is the
738 		 *    only owner of the associated prefix, or
739 		 * 2. the address does not obey autoconf and there is no
740 		 *    other owner of the prefix.
741 		 */
742 		if ((pr = nd6_prefix_lookup(&pr0)) != NULL &&
743 		    (((ia->ia6_flags & IN6_IFF_AUTOCONF) != 0 &&
744 		      pr->ndpr_refcnt == 1) ||
745 		     ((ia->ia6_flags & IN6_IFF_AUTOCONF) == 0 &&
746 		      pr->ndpr_refcnt == 0))) {
747 			pr->ndpr_expire = 1; /* XXX: just for expiration */
748 		}
749 
750 	  purgeaddr:
751 		in6_purgeaddr(&ia->ia_ifa);
752 		break;
753 	}
754 
755 	default:
756 		if (ifp == NULL || ifp->if_ioctl == 0)
757 			return(EOPNOTSUPP);
758 		return((*ifp->if_ioctl)(ifp, cmd, data));
759 	}
760 
761 	return(0);
762 }
763 
764 /*
765  * Update parameters of an IPv6 interface address.
766  * If necessary, a new entry is created and linked into address chains.
767  * This function is separated from in6_control().
768  * XXX: should this be performed under splnet()?
769  */
770 int
771 in6_update_ifa(ifp, ifra, ia)
772 	struct ifnet *ifp;
773 	struct in6_aliasreq *ifra;
774 	struct in6_ifaddr *ia;
775 {
776 	int error = 0, hostIsNew = 0, plen = -1;
777 	struct in6_ifaddr *oia;
778 	struct sockaddr_in6 dst6;
779 	struct in6_addrlifetime *lt;
780 
781 	/* Validate parameters */
782 	if (ifp == NULL || ifra == NULL) /* this maybe redundant */
783 		return(EINVAL);
784 
785 	/*
786 	 * The destination address for a p2p link must have a family
787 	 * of AF_UNSPEC or AF_INET6.
788 	 */
789 	if ((ifp->if_flags & IFF_POINTOPOINT) != 0 &&
790 	    ifra->ifra_dstaddr.sin6_family != AF_INET6 &&
791 	    ifra->ifra_dstaddr.sin6_family != AF_UNSPEC)
792 		return(EAFNOSUPPORT);
793 	/*
794 	 * validate ifra_prefixmask.  don't check sin6_family, netmask
795 	 * does not carry fields other than sin6_len.
796 	 */
797 	if (ifra->ifra_prefixmask.sin6_len > sizeof(struct sockaddr_in6))
798 		return(EINVAL);
799 	/*
800 	 * Because the IPv6 address architecture is classless, we require
801 	 * users to specify a (non 0) prefix length (mask) for a new address.
802 	 * We also require the prefix (when specified) mask is valid, and thus
803 	 * reject a non-consecutive mask.
804 	 */
805 	if (ia == NULL && ifra->ifra_prefixmask.sin6_len == 0)
806 		return(EINVAL);
807 	if (ifra->ifra_prefixmask.sin6_len != 0) {
808 		plen = in6_mask2len(&ifra->ifra_prefixmask.sin6_addr,
809 				    (u_char *)&ifra->ifra_prefixmask +
810 				    ifra->ifra_prefixmask.sin6_len);
811 		if (plen <= 0)
812 			return(EINVAL);
813 	}
814 	else {
815 		/*
816 		 * In this case, ia must not be NULL. We just use its prefix
817 		 * length.
818 		 */
819 		plen = in6_mask2len(&ia->ia_prefixmask.sin6_addr, NULL);
820 	}
821 	/*
822 	 * If the destination address on a p2p interface is specified,
823 	 * and the address is a scoped one, validate/set the scope
824 	 * zone identifier.
825 	 */
826 	dst6 = ifra->ifra_dstaddr;
827 	if ((ifp->if_flags & (IFF_POINTOPOINT|IFF_LOOPBACK)) &&
828 	    (dst6.sin6_family == AF_INET6)) {
829 		int scopeid;
830 
831 #ifndef SCOPEDROUTING
832 		if ((error = in6_recoverscope(&dst6,
833 					      &ifra->ifra_dstaddr.sin6_addr,
834 					      ifp)) != 0)
835 			return(error);
836 #endif
837 		scopeid = in6_addr2scopeid(ifp, &dst6.sin6_addr);
838 		if (dst6.sin6_scope_id == 0) /* user omit to specify the ID. */
839 			dst6.sin6_scope_id = scopeid;
840 		else if (dst6.sin6_scope_id != scopeid)
841 			return(EINVAL); /* scope ID mismatch. */
842 #ifndef SCOPEDROUTING
843 		if ((error = in6_embedscope(&dst6.sin6_addr, &dst6, NULL, NULL))
844 		    != 0)
845 			return(error);
846 		dst6.sin6_scope_id = 0; /* XXX */
847 #endif
848 	}
849 	/*
850 	 * The destination address can be specified only for a p2p or a
851 	 * loopback interface.  If specified, the corresponding prefix length
852 	 * must be 128.
853 	 */
854 	if (ifra->ifra_dstaddr.sin6_family == AF_INET6) {
855 		if ((ifp->if_flags & (IFF_POINTOPOINT|IFF_LOOPBACK)) == 0) {
856 			/* XXX: noisy message */
857 			log(LOG_INFO, "in6_update_ifa: a destination can be "
858 			    "specified for a p2p or a loopback IF only\n");
859 			return(EINVAL);
860 		}
861 		if (plen != 128) {
862 			/*
863 			 * The following message seems noisy, but we dare to
864 			 * add it for diagnosis.
865 			 */
866 			log(LOG_INFO, "in6_update_ifa: prefixlen must be 128 "
867 			    "when dstaddr is specified\n");
868 			return(EINVAL);
869 		}
870 	}
871 	/* lifetime consistency check */
872 	lt = &ifra->ifra_lifetime;
873 	if (lt->ia6t_vltime != ND6_INFINITE_LIFETIME
874 	    && lt->ia6t_vltime + time_second < time_second) {
875 		return EINVAL;
876 	}
877 	if (lt->ia6t_vltime == 0) {
878 		/*
879 		 * the following log might be noisy, but this is a typical
880 		 * configuration mistake or a tool's bug.
881 		 */
882 		log(LOG_INFO,
883 		    "in6_update_ifa: valid lifetime is 0 for %s\n",
884 		    ip6_sprintf(&ifra->ifra_addr.sin6_addr));
885 	}
886 	if (lt->ia6t_pltime != ND6_INFINITE_LIFETIME
887 	    && lt->ia6t_pltime + time_second < time_second) {
888 		return EINVAL;
889 	}
890 
891 	/*
892 	 * If this is a new address, allocate a new ifaddr and link it
893 	 * into chains.
894 	 */
895 	if (ia == NULL) {
896 		hostIsNew = 1;
897 		/*
898 		 * When in6_update_ifa() is called in a process of a received
899 		 * RA, it is called under splnet().  So, we should call malloc
900 		 * with M_NOWAIT.
901 		 */
902 		ia = (struct in6_ifaddr *)
903 			malloc(sizeof(*ia), M_IFADDR, M_NOWAIT);
904 		if (ia == NULL)
905 			return (ENOBUFS);
906 		bzero((caddr_t)ia, sizeof(*ia));
907 		/* Initialize the address and masks */
908 		ia->ia_ifa.ifa_addr = (struct sockaddr *)&ia->ia_addr;
909 		ia->ia_addr.sin6_family = AF_INET6;
910 		ia->ia_addr.sin6_len = sizeof(ia->ia_addr);
911 		if ((ifp->if_flags & (IFF_POINTOPOINT | IFF_LOOPBACK)) != 0) {
912 			/*
913 			 * XXX: some functions expect that ifa_dstaddr is not
914 			 * NULL for p2p interfaces.
915 			 */
916 			ia->ia_ifa.ifa_dstaddr
917 				= (struct sockaddr *)&ia->ia_dstaddr;
918 		} else {
919 			ia->ia_ifa.ifa_dstaddr = NULL;
920 		}
921 		ia->ia_ifa.ifa_netmask
922 			= (struct sockaddr *)&ia->ia_prefixmask;
923 
924 		ia->ia_ifp = ifp;
925 		if ((oia = in6_ifaddr) != NULL) {
926 			for ( ; oia->ia_next; oia = oia->ia_next)
927 				continue;
928 			oia->ia_next = ia;
929 		} else
930 			in6_ifaddr = ia;
931 
932 		TAILQ_INSERT_TAIL(&ifp->if_addrlist, &ia->ia_ifa,
933 				  ifa_list);
934 	}
935 
936 	/* set prefix mask */
937 	if (ifra->ifra_prefixmask.sin6_len) {
938 		/*
939 		 * We prohibit changing the prefix length of an existing
940 		 * address, because
941 		 * + such an operation should be rare in IPv6, and
942 		 * + the operation would confuse prefix management.
943 		 */
944 		if (ia->ia_prefixmask.sin6_len &&
945 		    in6_mask2len(&ia->ia_prefixmask.sin6_addr, NULL) != plen) {
946 			log(LOG_INFO, "in6_update_ifa: the prefix length of an"
947 			    " existing (%s) address should not be changed\n",
948 			    ip6_sprintf(&ia->ia_addr.sin6_addr));
949 			error = EINVAL;
950 			goto unlink;
951 		}
952 		ia->ia_prefixmask = ifra->ifra_prefixmask;
953 	}
954 
955 	/*
956 	 * If a new destination address is specified, scrub the old one and
957 	 * install the new destination.  Note that the interface must be
958 	 * p2p or loopback (see the check above.)
959 	 */
960 	if (dst6.sin6_family == AF_INET6 &&
961 	    !IN6_ARE_ADDR_EQUAL(&dst6.sin6_addr,
962 				&ia->ia_dstaddr.sin6_addr)) {
963 		int e;
964 
965 		if ((ia->ia_flags & IFA_ROUTE) != 0 &&
966 		    (e = rtinit(&(ia->ia_ifa), (int)RTM_DELETE, RTF_HOST))
967 		    != 0) {
968 			log(LOG_ERR, "in6_update_ifa: failed to remove "
969 			    "a route to the old destination: %s\n",
970 			    ip6_sprintf(&ia->ia_addr.sin6_addr));
971 			/* proceed anyway... */
972 		}
973 		else
974 			ia->ia_flags &= ~IFA_ROUTE;
975 		ia->ia_dstaddr = dst6;
976 	}
977 
978 	/* reset the interface and routing table appropriately. */
979 	if ((error = in6_ifinit(ifp, ia, &ifra->ifra_addr, hostIsNew)) != 0)
980 		goto unlink;
981 
982 	/*
983 	 * Beyond this point, we should call in6_purgeaddr upon an error,
984 	 * not just go to unlink.
985 	 */
986 
987 #if 0				/* disable this mechanism for now */
988 	/* update prefix list */
989 	if (hostIsNew &&
990 	    (ifra->ifra_flags & IN6_IFF_NOPFX) == 0) { /* XXX */
991 		int iilen;
992 
993 		iilen = (sizeof(ia->ia_prefixmask.sin6_addr) << 3) - plen;
994 		if ((error = in6_prefix_add_ifid(iilen, ia)) != 0) {
995 			in6_purgeaddr((struct ifaddr *)ia);
996 			return(error);
997 		}
998 	}
999 #endif
1000 
1001 	if ((ifp->if_flags & IFF_MULTICAST) != 0) {
1002 		struct sockaddr_in6 mltaddr, mltmask;
1003 		struct in6_multi *in6m;
1004 
1005 		if (hostIsNew) {
1006 			/*
1007 			 * join solicited multicast addr for new host id
1008 			 */
1009 			struct in6_addr llsol;
1010 			bzero(&llsol, sizeof(struct in6_addr));
1011 			llsol.s6_addr16[0] = htons(0xff02);
1012 			llsol.s6_addr16[1] = htons(ifp->if_index);
1013 			llsol.s6_addr32[1] = 0;
1014 			llsol.s6_addr32[2] = htonl(1);
1015 			llsol.s6_addr32[3] =
1016 				ifra->ifra_addr.sin6_addr.s6_addr32[3];
1017 			llsol.s6_addr8[12] = 0xff;
1018 			(void)in6_addmulti(&llsol, ifp, &error);
1019 			if (error != 0) {
1020 				log(LOG_WARNING,
1021 				    "in6_update_ifa: addmulti failed for "
1022 				    "%s on %s (errno=%d)\n",
1023 				    ip6_sprintf(&llsol), if_name(ifp),
1024 				    error);
1025 				in6_purgeaddr((struct ifaddr *)ia);
1026 				return(error);
1027 			}
1028 		}
1029 
1030 		bzero(&mltmask, sizeof(mltmask));
1031 		mltmask.sin6_len = sizeof(struct sockaddr_in6);
1032 		mltmask.sin6_family = AF_INET6;
1033 		mltmask.sin6_addr = in6mask32;
1034 
1035 		/*
1036 		 * join link-local all-nodes address
1037 		 */
1038 		bzero(&mltaddr, sizeof(mltaddr));
1039 		mltaddr.sin6_len = sizeof(struct sockaddr_in6);
1040 		mltaddr.sin6_family = AF_INET6;
1041 		mltaddr.sin6_addr = in6addr_linklocal_allnodes;
1042 		mltaddr.sin6_addr.s6_addr16[1] = htons(ifp->if_index);
1043 
1044 		IN6_LOOKUP_MULTI(mltaddr.sin6_addr, ifp, in6m);
1045 		if (in6m == NULL) {
1046 			rtrequest(RTM_ADD,
1047 				  (struct sockaddr *)&mltaddr,
1048 				  (struct sockaddr *)&ia->ia_addr,
1049 				  (struct sockaddr *)&mltmask,
1050 				  RTF_UP|RTF_CLONING,  /* xxx */
1051 				  (struct rtentry **)0);
1052 			(void)in6_addmulti(&mltaddr.sin6_addr, ifp, &error);
1053 			if (error != 0) {
1054 				log(LOG_WARNING,
1055 				    "in6_update_ifa: addmulti failed for "
1056 				    "%s on %s (errno=%d)\n",
1057 				    ip6_sprintf(&mltaddr.sin6_addr),
1058 				    if_name(ifp), error);
1059 			}
1060 		}
1061 
1062 		/*
1063 		 * join node information group address
1064 		 */
1065 #define hostnamelen	strlen(hostname)
1066 		if (in6_nigroup(ifp, hostname, hostnamelen, &mltaddr.sin6_addr)
1067 		    == 0) {
1068 			IN6_LOOKUP_MULTI(mltaddr.sin6_addr, ifp, in6m);
1069 			if (in6m == NULL && ia != NULL) {
1070 				(void)in6_addmulti(&mltaddr.sin6_addr,
1071 				    ifp, &error);
1072 				if (error != 0) {
1073 					log(LOG_WARNING, "in6_update_ifa: "
1074 					    "addmulti failed for "
1075 					    "%s on %s (errno=%d)\n",
1076 					    ip6_sprintf(&mltaddr.sin6_addr),
1077 					    if_name(ifp), error);
1078 				}
1079 			}
1080 		}
1081 #undef hostnamelen
1082 
1083 		/*
1084 		 * join node-local all-nodes address, on loopback.
1085 		 * XXX: since "node-local" is obsoleted by interface-local,
1086 		 *      we have to join the group on every interface with
1087 		 *      some interface-boundary restriction.
1088 		 */
1089 		if (ifp->if_flags & IFF_LOOPBACK) {
1090 			struct in6_ifaddr *ia_loop;
1091 
1092 			struct in6_addr loop6 = in6addr_loopback;
1093 			ia_loop = in6ifa_ifpwithaddr(ifp, &loop6);
1094 
1095 			mltaddr.sin6_addr = in6addr_nodelocal_allnodes;
1096 
1097 			IN6_LOOKUP_MULTI(mltaddr.sin6_addr, ifp, in6m);
1098 			if (in6m == NULL && ia_loop != NULL) {
1099 				rtrequest(RTM_ADD,
1100 					  (struct sockaddr *)&mltaddr,
1101 					  (struct sockaddr *)&ia_loop->ia_addr,
1102 					  (struct sockaddr *)&mltmask,
1103 					  RTF_UP,
1104 					  (struct rtentry **)0);
1105 				(void)in6_addmulti(&mltaddr.sin6_addr, ifp,
1106 						   &error);
1107 				if (error != 0) {
1108 					log(LOG_WARNING, "in6_update_ifa: "
1109 					    "addmulti failed for %s on %s "
1110 					    "(errno=%d)\n",
1111 					    ip6_sprintf(&mltaddr.sin6_addr),
1112 					    if_name(ifp), error);
1113 				}
1114 			}
1115 		}
1116 	}
1117 
1118 	ia->ia6_flags = ifra->ifra_flags;
1119 	ia->ia6_flags &= ~IN6_IFF_DUPLICATED;	/*safety*/
1120 	ia->ia6_flags &= ~IN6_IFF_NODAD;	/* Mobile IPv6 */
1121 
1122 	ia->ia6_lifetime = ifra->ifra_lifetime;
1123 	/* for sanity */
1124 	if (ia->ia6_lifetime.ia6t_vltime != ND6_INFINITE_LIFETIME) {
1125 		ia->ia6_lifetime.ia6t_expire =
1126 			time_second + ia->ia6_lifetime.ia6t_vltime;
1127 	} else
1128 		ia->ia6_lifetime.ia6t_expire = 0;
1129 	if (ia->ia6_lifetime.ia6t_pltime != ND6_INFINITE_LIFETIME) {
1130 		ia->ia6_lifetime.ia6t_preferred =
1131 			time_second + ia->ia6_lifetime.ia6t_pltime;
1132 	} else
1133 		ia->ia6_lifetime.ia6t_preferred = 0;
1134 
1135 	/*
1136 	 * make sure to initialize ND6 information.  this is to workaround
1137 	 * issues with interfaces with IPv6 addresses, which have never brought
1138 	 * up.  We are assuming that it is safe to nd6_ifattach multiple times.
1139 	 */
1140 	nd6_ifattach(ifp);
1141 
1142 	/*
1143 	 * Perform DAD, if needed.
1144 	 * XXX It may be of use, if we can administratively
1145 	 * disable DAD.
1146 	 */
1147 	if (in6if_do_dad(ifp) && (ifra->ifra_flags & IN6_IFF_NODAD) == 0) {
1148 		ia->ia6_flags |= IN6_IFF_TENTATIVE;
1149 		nd6_dad_start((struct ifaddr *)ia, NULL);
1150 	}
1151 
1152 	return(error);
1153 
1154   unlink:
1155 	/*
1156 	 * XXX: if a change of an existing address failed, keep the entry
1157 	 * anyway.
1158 	 */
1159 	if (hostIsNew)
1160 		in6_unlink_ifa(ia, ifp);
1161 	return(error);
1162 }
1163 
1164 void
1165 in6_purgeaddr(ifa)
1166 	struct ifaddr *ifa;
1167 {
1168 	struct ifnet *ifp = ifa->ifa_ifp;
1169 	struct in6_ifaddr *ia = (struct in6_ifaddr *) ifa;
1170 
1171 	/* stop DAD processing */
1172 	nd6_dad_stop(ifa);
1173 
1174 	/*
1175 	 * delete route to the destination of the address being purged.
1176 	 * The interface must be p2p or loopback in this case.
1177 	 */
1178 	if ((ia->ia_flags & IFA_ROUTE) != 0 && ia->ia_dstaddr.sin6_len != 0) {
1179 		int e;
1180 
1181 		if ((e = rtinit(&(ia->ia_ifa), (int)RTM_DELETE, RTF_HOST))
1182 		    != 0) {
1183 			log(LOG_ERR, "in6_purgeaddr: failed to remove "
1184 			    "a route to the p2p destination: %s on %s, "
1185 			    "errno=%d\n",
1186 			    ip6_sprintf(&ia->ia_addr.sin6_addr), if_name(ifp),
1187 			    e);
1188 			/* proceed anyway... */
1189 		}
1190 		else
1191 			ia->ia_flags &= ~IFA_ROUTE;
1192 	}
1193 
1194 	/* Remove ownaddr's loopback rtentry, if it exists. */
1195 	in6_ifremloop(&(ia->ia_ifa));
1196 
1197 	if (ifp->if_flags & IFF_MULTICAST) {
1198 		/*
1199 		 * delete solicited multicast addr for deleting host id
1200 		 */
1201 		struct in6_multi *in6m;
1202 		struct in6_addr llsol;
1203 		bzero(&llsol, sizeof(struct in6_addr));
1204 		llsol.s6_addr16[0] = htons(0xff02);
1205 		llsol.s6_addr16[1] = htons(ifp->if_index);
1206 		llsol.s6_addr32[1] = 0;
1207 		llsol.s6_addr32[2] = htonl(1);
1208 		llsol.s6_addr32[3] =
1209 			ia->ia_addr.sin6_addr.s6_addr32[3];
1210 		llsol.s6_addr8[12] = 0xff;
1211 
1212 		IN6_LOOKUP_MULTI(llsol, ifp, in6m);
1213 		if (in6m)
1214 			in6_delmulti(in6m);
1215 	}
1216 
1217 	in6_unlink_ifa(ia, ifp);
1218 }
1219 
1220 static void
1221 in6_unlink_ifa(ia, ifp)
1222 	struct in6_ifaddr *ia;
1223 	struct ifnet *ifp;
1224 {
1225 	int plen, iilen;
1226 	struct in6_ifaddr *oia;
1227 	int	s = splnet();
1228 
1229 	TAILQ_REMOVE(&ifp->if_addrlist, &ia->ia_ifa, ifa_list);
1230 
1231 	oia = ia;
1232 	if (oia == (ia = in6_ifaddr))
1233 		in6_ifaddr = ia->ia_next;
1234 	else {
1235 		while (ia->ia_next && (ia->ia_next != oia))
1236 			ia = ia->ia_next;
1237 		if (ia->ia_next)
1238 			ia->ia_next = oia->ia_next;
1239 		else {
1240 			/* search failed */
1241 			printf("Couldn't unlink in6_ifaddr from in6_ifaddr\n");
1242 		}
1243 	}
1244 
1245 	if (oia->ia6_ifpr) {	/* check for safety */
1246 		plen = in6_mask2len(&oia->ia_prefixmask.sin6_addr, NULL);
1247 		iilen = (sizeof(oia->ia_prefixmask.sin6_addr) << 3) - plen;
1248 		in6_prefix_remove_ifid(iilen, oia);
1249 	}
1250 
1251 	/*
1252 	 * When an autoconfigured address is being removed, release the
1253 	 * reference to the base prefix.  Also, since the release might
1254 	 * affect the status of other (detached) addresses, call
1255 	 * pfxlist_onlink_check().
1256 	 */
1257 	if ((oia->ia6_flags & IN6_IFF_AUTOCONF) != 0) {
1258 		if (oia->ia6_ndpr == NULL) {
1259 			log(LOG_NOTICE, "in6_unlink_ifa: autoconf'ed address "
1260 			    "%p has no prefix\n", oia);
1261 		} else {
1262 			oia->ia6_ndpr->ndpr_refcnt--;
1263 			oia->ia6_flags &= ~IN6_IFF_AUTOCONF;
1264 			oia->ia6_ndpr = NULL;
1265 		}
1266 
1267 		pfxlist_onlink_check();
1268 	}
1269 
1270 	/*
1271 	 * release another refcnt for the link from in6_ifaddr.
1272 	 * Note that we should decrement the refcnt at least once for all *BSD.
1273 	 */
1274 	IFAFREE(&oia->ia_ifa);
1275 
1276 	splx(s);
1277 }
1278 
1279 void
1280 in6_purgeif(ifp)
1281 	struct ifnet *ifp;
1282 {
1283 	struct ifaddr *ifa, *nifa;
1284 
1285 	for (ifa = TAILQ_FIRST(&ifp->if_addrlist); ifa != NULL; ifa = nifa)
1286 	{
1287 		nifa = TAILQ_NEXT(ifa, ifa_list);
1288 		if (ifa->ifa_addr->sa_family != AF_INET6)
1289 			continue;
1290 		in6_purgeaddr(ifa);
1291 	}
1292 
1293 	in6_ifdetach(ifp);
1294 }
1295 
1296 /*
1297  * SIOC[GAD]LIFADDR.
1298  *	SIOCGLIFADDR: get first address. (?)
1299  *	SIOCGLIFADDR with IFLR_PREFIX:
1300  *		get first address that matches the specified prefix.
1301  *	SIOCALIFADDR: add the specified address.
1302  *	SIOCALIFADDR with IFLR_PREFIX:
1303  *		add the specified prefix, filling hostid part from
1304  *		the first link-local address.  prefixlen must be <= 64.
1305  *	SIOCDLIFADDR: delete the specified address.
1306  *	SIOCDLIFADDR with IFLR_PREFIX:
1307  *		delete the first address that matches the specified prefix.
1308  * return values:
1309  *	EINVAL on invalid parameters
1310  *	EADDRNOTAVAIL on prefix match failed/specified address not found
1311  *	other values may be returned from in6_ioctl()
1312  *
1313  * NOTE: SIOCALIFADDR(with IFLR_PREFIX set) allows prefixlen less than 64.
1314  * this is to accomodate address naming scheme other than RFC2374,
1315  * in the future.
1316  * RFC2373 defines interface id to be 64bit, but it allows non-RFC2374
1317  * address encoding scheme. (see figure on page 8)
1318  */
1319 static int
1320 in6_lifaddr_ioctl(so, cmd, data, ifp, td)
1321 	struct socket *so;
1322 	u_long cmd;
1323 	caddr_t	data;
1324 	struct ifnet *ifp;
1325 	struct thread *td;
1326 {
1327 	struct if_laddrreq *iflr = (struct if_laddrreq *)data;
1328 	struct ifaddr *ifa;
1329 	struct sockaddr *sa;
1330 
1331 	/* sanity checks */
1332 	if (!data || !ifp) {
1333 		panic("invalid argument to in6_lifaddr_ioctl");
1334 		/*NOTRECHED*/
1335 	}
1336 
1337 	switch (cmd) {
1338 	case SIOCGLIFADDR:
1339 		/* address must be specified on GET with IFLR_PREFIX */
1340 		if ((iflr->flags & IFLR_PREFIX) == 0)
1341 			break;
1342 		/*FALLTHROUGH*/
1343 	case SIOCALIFADDR:
1344 	case SIOCDLIFADDR:
1345 		/* address must be specified on ADD and DELETE */
1346 		sa = (struct sockaddr *)&iflr->addr;
1347 		if (sa->sa_family != AF_INET6)
1348 			return EINVAL;
1349 		if (sa->sa_len != sizeof(struct sockaddr_in6))
1350 			return EINVAL;
1351 		/* XXX need improvement */
1352 		sa = (struct sockaddr *)&iflr->dstaddr;
1353 		if (sa->sa_family && sa->sa_family != AF_INET6)
1354 			return EINVAL;
1355 		if (sa->sa_len && sa->sa_len != sizeof(struct sockaddr_in6))
1356 			return EINVAL;
1357 		break;
1358 	default: /*shouldn't happen*/
1359 #if 0
1360 		panic("invalid cmd to in6_lifaddr_ioctl");
1361 		/*NOTREACHED*/
1362 #else
1363 		return EOPNOTSUPP;
1364 #endif
1365 	}
1366 	if (sizeof(struct in6_addr) * 8 < iflr->prefixlen)
1367 		return EINVAL;
1368 
1369 	switch (cmd) {
1370 	case SIOCALIFADDR:
1371 	    {
1372 		struct in6_aliasreq ifra;
1373 		struct in6_addr *hostid = NULL;
1374 		int prefixlen;
1375 
1376 		if ((iflr->flags & IFLR_PREFIX) != 0) {
1377 			struct sockaddr_in6 *sin6;
1378 
1379 			/*
1380 			 * hostid is to fill in the hostid part of the
1381 			 * address.  hostid points to the first link-local
1382 			 * address attached to the interface.
1383 			 */
1384 			ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp, 0);
1385 			if (!ifa)
1386 				return EADDRNOTAVAIL;
1387 			hostid = IFA_IN6(ifa);
1388 
1389 		 	/* prefixlen must be <= 64. */
1390 			if (64 < iflr->prefixlen)
1391 				return EINVAL;
1392 			prefixlen = iflr->prefixlen;
1393 
1394 			/* hostid part must be zero. */
1395 			sin6 = (struct sockaddr_in6 *)&iflr->addr;
1396 			if (sin6->sin6_addr.s6_addr32[2] != 0
1397 			 || sin6->sin6_addr.s6_addr32[3] != 0) {
1398 				return EINVAL;
1399 			}
1400 		} else
1401 			prefixlen = iflr->prefixlen;
1402 
1403 		/* copy args to in6_aliasreq, perform ioctl(SIOCAIFADDR_IN6). */
1404 		bzero(&ifra, sizeof(ifra));
1405 		bcopy(iflr->iflr_name, ifra.ifra_name,
1406 			sizeof(ifra.ifra_name));
1407 
1408 		bcopy(&iflr->addr, &ifra.ifra_addr,
1409 			((struct sockaddr *)&iflr->addr)->sa_len);
1410 		if (hostid) {
1411 			/* fill in hostid part */
1412 			ifra.ifra_addr.sin6_addr.s6_addr32[2] =
1413 				hostid->s6_addr32[2];
1414 			ifra.ifra_addr.sin6_addr.s6_addr32[3] =
1415 				hostid->s6_addr32[3];
1416 		}
1417 
1418 		if (((struct sockaddr *)&iflr->dstaddr)->sa_family) {	/*XXX*/
1419 			bcopy(&iflr->dstaddr, &ifra.ifra_dstaddr,
1420 				((struct sockaddr *)&iflr->dstaddr)->sa_len);
1421 			if (hostid) {
1422 				ifra.ifra_dstaddr.sin6_addr.s6_addr32[2] =
1423 					hostid->s6_addr32[2];
1424 				ifra.ifra_dstaddr.sin6_addr.s6_addr32[3] =
1425 					hostid->s6_addr32[3];
1426 			}
1427 		}
1428 
1429 		ifra.ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6);
1430 		in6_len2mask(&ifra.ifra_prefixmask.sin6_addr, prefixlen);
1431 
1432 		ifra.ifra_flags = iflr->flags & ~IFLR_PREFIX;
1433 		return in6_control(so, SIOCAIFADDR_IN6, (caddr_t)&ifra, ifp, td);
1434 	    }
1435 	case SIOCGLIFADDR:
1436 	case SIOCDLIFADDR:
1437 	    {
1438 		struct in6_ifaddr *ia;
1439 		struct in6_addr mask, candidate, match;
1440 		struct sockaddr_in6 *sin6;
1441 		int cmp;
1442 
1443 		bzero(&mask, sizeof(mask));
1444 		if (iflr->flags & IFLR_PREFIX) {
1445 			/* lookup a prefix rather than address. */
1446 			in6_len2mask(&mask, iflr->prefixlen);
1447 
1448 			sin6 = (struct sockaddr_in6 *)&iflr->addr;
1449 			bcopy(&sin6->sin6_addr, &match, sizeof(match));
1450 			match.s6_addr32[0] &= mask.s6_addr32[0];
1451 			match.s6_addr32[1] &= mask.s6_addr32[1];
1452 			match.s6_addr32[2] &= mask.s6_addr32[2];
1453 			match.s6_addr32[3] &= mask.s6_addr32[3];
1454 
1455 			/* if you set extra bits, that's wrong */
1456 			if (bcmp(&match, &sin6->sin6_addr, sizeof(match)))
1457 				return EINVAL;
1458 
1459 			cmp = 1;
1460 		} else {
1461 			if (cmd == SIOCGLIFADDR) {
1462 				/* on getting an address, take the 1st match */
1463 				cmp = 0;	/*XXX*/
1464 			} else {
1465 				/* on deleting an address, do exact match */
1466 				in6_len2mask(&mask, 128);
1467 				sin6 = (struct sockaddr_in6 *)&iflr->addr;
1468 				bcopy(&sin6->sin6_addr, &match, sizeof(match));
1469 
1470 				cmp = 1;
1471 			}
1472 		}
1473 
1474 		TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list)
1475 		{
1476 			if (ifa->ifa_addr->sa_family != AF_INET6)
1477 				continue;
1478 			if (!cmp)
1479 				break;
1480 
1481 			bcopy(IFA_IN6(ifa), &candidate, sizeof(candidate));
1482 #ifndef SCOPEDROUTING
1483 			/*
1484 			 * XXX: this is adhoc, but is necessary to allow
1485 			 * a user to specify fe80::/64 (not /10) for a
1486 			 * link-local address.
1487 			 */
1488 			if (IN6_IS_ADDR_LINKLOCAL(&candidate))
1489 				candidate.s6_addr16[1] = 0;
1490 #endif
1491 			candidate.s6_addr32[0] &= mask.s6_addr32[0];
1492 			candidate.s6_addr32[1] &= mask.s6_addr32[1];
1493 			candidate.s6_addr32[2] &= mask.s6_addr32[2];
1494 			candidate.s6_addr32[3] &= mask.s6_addr32[3];
1495 			if (IN6_ARE_ADDR_EQUAL(&candidate, &match))
1496 				break;
1497 		}
1498 		if (!ifa)
1499 			return EADDRNOTAVAIL;
1500 		ia = ifa2ia6(ifa);
1501 
1502 		if (cmd == SIOCGLIFADDR) {
1503 #ifndef SCOPEDROUTING
1504 			struct sockaddr_in6 *s6;
1505 #endif
1506 
1507 			/* fill in the if_laddrreq structure */
1508 			bcopy(&ia->ia_addr, &iflr->addr, ia->ia_addr.sin6_len);
1509 #ifndef SCOPEDROUTING		/* XXX see above */
1510 			s6 = (struct sockaddr_in6 *)&iflr->addr;
1511 			if (IN6_IS_ADDR_LINKLOCAL(&s6->sin6_addr)) {
1512 				s6->sin6_addr.s6_addr16[1] = 0;
1513 				s6->sin6_scope_id =
1514 					in6_addr2scopeid(ifp, &s6->sin6_addr);
1515 			}
1516 #endif
1517 			if ((ifp->if_flags & IFF_POINTOPOINT) != 0) {
1518 				bcopy(&ia->ia_dstaddr, &iflr->dstaddr,
1519 					ia->ia_dstaddr.sin6_len);
1520 #ifndef SCOPEDROUTING		/* XXX see above */
1521 				s6 = (struct sockaddr_in6 *)&iflr->dstaddr;
1522 				if (IN6_IS_ADDR_LINKLOCAL(&s6->sin6_addr)) {
1523 					s6->sin6_addr.s6_addr16[1] = 0;
1524 					s6->sin6_scope_id =
1525 						in6_addr2scopeid(ifp,
1526 								 &s6->sin6_addr);
1527 				}
1528 #endif
1529 			} else
1530 				bzero(&iflr->dstaddr, sizeof(iflr->dstaddr));
1531 
1532 			iflr->prefixlen =
1533 				in6_mask2len(&ia->ia_prefixmask.sin6_addr,
1534 					     NULL);
1535 
1536 			iflr->flags = ia->ia6_flags;	/*XXX*/
1537 
1538 			return 0;
1539 		} else {
1540 			struct in6_aliasreq ifra;
1541 
1542 			/* fill in6_aliasreq and do ioctl(SIOCDIFADDR_IN6) */
1543 			bzero(&ifra, sizeof(ifra));
1544 			bcopy(iflr->iflr_name, ifra.ifra_name,
1545 				sizeof(ifra.ifra_name));
1546 
1547 			bcopy(&ia->ia_addr, &ifra.ifra_addr,
1548 				ia->ia_addr.sin6_len);
1549 			if ((ifp->if_flags & IFF_POINTOPOINT) != 0) {
1550 				bcopy(&ia->ia_dstaddr, &ifra.ifra_dstaddr,
1551 					ia->ia_dstaddr.sin6_len);
1552 			} else {
1553 				bzero(&ifra.ifra_dstaddr,
1554 				    sizeof(ifra.ifra_dstaddr));
1555 			}
1556 			bcopy(&ia->ia_prefixmask, &ifra.ifra_dstaddr,
1557 				ia->ia_prefixmask.sin6_len);
1558 
1559 			ifra.ifra_flags = ia->ia6_flags;
1560 			return in6_control(so, SIOCDIFADDR_IN6, (caddr_t)&ifra,
1561 				ifp, td);
1562 		}
1563 	    }
1564 	}
1565 
1566 	return EOPNOTSUPP;	/*just for safety*/
1567 }
1568 
1569 /*
1570  * Initialize an interface's intetnet6 address
1571  * and routing table entry.
1572  */
1573 static int
1574 in6_ifinit(ifp, ia, sin6, newhost)
1575 	struct ifnet *ifp;
1576 	struct in6_ifaddr *ia;
1577 	struct sockaddr_in6 *sin6;
1578 	int newhost;
1579 {
1580 	int	error = 0, plen, ifacount = 0;
1581 	int	s = splimp();
1582 	struct ifaddr *ifa;
1583 
1584 	/*
1585 	 * Give the interface a chance to initialize
1586 	 * if this is its first address,
1587 	 * and to validate the address if necessary.
1588 	 */
1589 	TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list)
1590 	{
1591 		if (ifa->ifa_addr == NULL)
1592 			continue;	/* just for safety */
1593 		if (ifa->ifa_addr->sa_family != AF_INET6)
1594 			continue;
1595 		ifacount++;
1596 	}
1597 
1598 	ia->ia_addr = *sin6;
1599 
1600 	if (ifacount <= 1 && ifp->if_ioctl &&
1601 	    (error = (*ifp->if_ioctl)(ifp, SIOCSIFADDR, (caddr_t)ia))) {
1602 		splx(s);
1603 		return(error);
1604 	}
1605 	splx(s);
1606 
1607 	ia->ia_ifa.ifa_metric = ifp->if_metric;
1608 
1609 	/* we could do in(6)_socktrim here, but just omit it at this moment. */
1610 
1611 	/*
1612 	 * Special case:
1613 	 * If the destination address is specified for a point-to-point
1614 	 * interface, install a route to the destination as an interface
1615 	 * direct route.
1616 	 */
1617 	plen = in6_mask2len(&ia->ia_prefixmask.sin6_addr, NULL); /* XXX */
1618 	if (plen == 128 && ia->ia_dstaddr.sin6_family == AF_INET6) {
1619 		if ((error = rtinit(&(ia->ia_ifa), (int)RTM_ADD,
1620 				    RTF_UP | RTF_HOST)) != 0)
1621 			return(error);
1622 		ia->ia_flags |= IFA_ROUTE;
1623 	}
1624 	if (plen < 128) {
1625 		/*
1626 		 * The RTF_CLONING flag is necessary for in6_is_ifloop_auto().
1627 		 */
1628 		ia->ia_ifa.ifa_flags |= RTF_CLONING;
1629 	}
1630 
1631 	/* Add ownaddr as loopback rtentry, if necessary(ex. on p2p link). */
1632 	if (newhost) {
1633 		/* set the rtrequest function to create llinfo */
1634 		ia->ia_ifa.ifa_rtrequest = nd6_rtrequest;
1635 		in6_ifaddloop(&(ia->ia_ifa));
1636 	}
1637 
1638 	return(error);
1639 }
1640 
1641 /*
1642  * Add an address to the list of IP6 multicast addresses for a
1643  * given interface.
1644  */
1645 struct	in6_multi *
1646 in6_addmulti(maddr6, ifp, errorp)
1647 	struct in6_addr *maddr6;
1648 	struct ifnet *ifp;
1649 	int *errorp;
1650 {
1651 	struct	in6_multi *in6m;
1652 	struct sockaddr_in6 sin6;
1653 	struct ifmultiaddr *ifma;
1654 	int	s = splnet();
1655 
1656 	*errorp = 0;
1657 
1658 	/*
1659 	 * Call generic routine to add membership or increment
1660 	 * refcount.  It wants addresses in the form of a sockaddr,
1661 	 * so we build one here (being careful to zero the unused bytes).
1662 	 */
1663 	bzero(&sin6, sizeof sin6);
1664 	sin6.sin6_family = AF_INET6;
1665 	sin6.sin6_len = sizeof sin6;
1666 	sin6.sin6_addr = *maddr6;
1667 	*errorp = if_addmulti(ifp, (struct sockaddr *)&sin6, &ifma);
1668 	if (*errorp) {
1669 		splx(s);
1670 		return 0;
1671 	}
1672 
1673 	/*
1674 	 * If ifma->ifma_protospec is null, then if_addmulti() created
1675 	 * a new record.  Otherwise, we are done.
1676 	 */
1677 	if (ifma->ifma_protospec != 0)
1678 		return ifma->ifma_protospec;
1679 
1680 	/* XXX - if_addmulti uses M_WAITOK.  Can this really be called
1681 	   at interrupt time?  If so, need to fix if_addmulti. XXX */
1682 	in6m = (struct in6_multi *)malloc(sizeof(*in6m), M_IPMADDR, M_NOWAIT);
1683 	if (in6m == NULL) {
1684 		splx(s);
1685 		return (NULL);
1686 	}
1687 
1688 	bzero(in6m, sizeof *in6m);
1689 	in6m->in6m_addr = *maddr6;
1690 	in6m->in6m_ifp = ifp;
1691 	in6m->in6m_ifma = ifma;
1692 	ifma->ifma_protospec = in6m;
1693 	LIST_INSERT_HEAD(&in6_multihead, in6m, in6m_entry);
1694 
1695 	/*
1696 	 * Let MLD6 know that we have joined a new IP6 multicast
1697 	 * group.
1698 	 */
1699 	mld6_start_listening(in6m);
1700 	splx(s);
1701 	return(in6m);
1702 }
1703 
1704 /*
1705  * Delete a multicast address record.
1706  */
1707 void
1708 in6_delmulti(in6m)
1709 	struct in6_multi *in6m;
1710 {
1711 	struct ifmultiaddr *ifma = in6m->in6m_ifma;
1712 	int	s = splnet();
1713 
1714 	if (ifma->ifma_refcount == 1) {
1715 		/*
1716 		 * No remaining claims to this record; let MLD6 know
1717 		 * that we are leaving the multicast group.
1718 		 */
1719 		mld6_stop_listening(in6m);
1720 		ifma->ifma_protospec = 0;
1721 		LIST_REMOVE(in6m, in6m_entry);
1722 		free(in6m, M_IPMADDR);
1723 	}
1724 	/* XXX - should be separate API for when we have an ifma? */
1725 	if_delmulti(ifma->ifma_ifp, ifma->ifma_addr);
1726 	splx(s);
1727 }
1728 
1729 /*
1730  * Find an IPv6 interface link-local address specific to an interface.
1731  */
1732 struct in6_ifaddr *
1733 in6ifa_ifpforlinklocal(ifp, ignoreflags)
1734 	struct ifnet *ifp;
1735 	int ignoreflags;
1736 {
1737 	struct ifaddr *ifa;
1738 
1739 	TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list)
1740 	{
1741 		if (ifa->ifa_addr == NULL)
1742 			continue;	/* just for safety */
1743 		if (ifa->ifa_addr->sa_family != AF_INET6)
1744 			continue;
1745 		if (IN6_IS_ADDR_LINKLOCAL(IFA_IN6(ifa))) {
1746 			if ((((struct in6_ifaddr *)ifa)->ia6_flags &
1747 			     ignoreflags) != 0)
1748 				continue;
1749 			break;
1750 		}
1751 	}
1752 
1753 	return((struct in6_ifaddr *)ifa);
1754 }
1755 
1756 
1757 /*
1758  * find the internet address corresponding to a given interface and address.
1759  */
1760 struct in6_ifaddr *
1761 in6ifa_ifpwithaddr(ifp, addr)
1762 	struct ifnet *ifp;
1763 	struct in6_addr *addr;
1764 {
1765 	struct ifaddr *ifa;
1766 
1767 	TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list)
1768 	{
1769 		if (ifa->ifa_addr == NULL)
1770 			continue;	/* just for safety */
1771 		if (ifa->ifa_addr->sa_family != AF_INET6)
1772 			continue;
1773 		if (IN6_ARE_ADDR_EQUAL(addr, IFA_IN6(ifa)))
1774 			break;
1775 	}
1776 
1777 	return((struct in6_ifaddr *)ifa);
1778 }
1779 
1780 /*
1781  * Convert IP6 address to printable (loggable) representation.
1782  */
1783 static char digits[] = "0123456789abcdef";
1784 static int ip6round = 0;
1785 char *
1786 ip6_sprintf(addr)
1787 	const struct in6_addr *addr;
1788 {
1789 	static char ip6buf[8][48];
1790 	int i;
1791 	char *cp;
1792 	u_short *a = (u_short *)addr;
1793 	u_char *d;
1794 	int dcolon = 0;
1795 
1796 	ip6round = (ip6round + 1) & 7;
1797 	cp = ip6buf[ip6round];
1798 
1799 	for (i = 0; i < 8; i++) {
1800 		if (dcolon == 1) {
1801 			if (*a == 0) {
1802 				if (i == 7)
1803 					*cp++ = ':';
1804 				a++;
1805 				continue;
1806 			} else
1807 				dcolon = 2;
1808 		}
1809 		if (*a == 0) {
1810 			if (dcolon == 0 && *(a + 1) == 0) {
1811 				if (i == 0)
1812 					*cp++ = ':';
1813 				*cp++ = ':';
1814 				dcolon = 1;
1815 			} else {
1816 				*cp++ = '0';
1817 				*cp++ = ':';
1818 			}
1819 			a++;
1820 			continue;
1821 		}
1822 		d = (u_char *)a;
1823 		*cp++ = digits[*d >> 4];
1824 		*cp++ = digits[*d++ & 0xf];
1825 		*cp++ = digits[*d >> 4];
1826 		*cp++ = digits[*d & 0xf];
1827 		*cp++ = ':';
1828 		a++;
1829 	}
1830 	*--cp = 0;
1831 	return(ip6buf[ip6round]);
1832 }
1833 
1834 int
1835 in6_localaddr(in6)
1836 	struct in6_addr *in6;
1837 {
1838 	struct in6_ifaddr *ia;
1839 
1840 	if (IN6_IS_ADDR_LOOPBACK(in6) || IN6_IS_ADDR_LINKLOCAL(in6))
1841 		return 1;
1842 
1843 	for (ia = in6_ifaddr; ia; ia = ia->ia_next)
1844 		if (IN6_ARE_MASKED_ADDR_EQUAL(in6, &ia->ia_addr.sin6_addr,
1845 					      &ia->ia_prefixmask.sin6_addr))
1846 			return 1;
1847 
1848 	return (0);
1849 }
1850 
1851 int
1852 in6_is_addr_deprecated(sa6)
1853 	struct sockaddr_in6 *sa6;
1854 {
1855 	struct in6_ifaddr *ia;
1856 
1857 	for (ia = in6_ifaddr; ia; ia = ia->ia_next) {
1858 		if (IN6_ARE_ADDR_EQUAL(&ia->ia_addr.sin6_addr,
1859 				       &sa6->sin6_addr) &&
1860 #ifdef SCOPEDROUTING
1861 		    ia->ia_addr.sin6_scope_id == sa6->sin6_scope_id &&
1862 #endif
1863 		    (ia->ia6_flags & IN6_IFF_DEPRECATED) != 0)
1864 			return(1); /* true */
1865 
1866 		/* XXX: do we still have to go thru the rest of the list? */
1867 	}
1868 
1869 	return(0);		/* false */
1870 }
1871 
1872 /*
1873  * return length of part which dst and src are equal
1874  * hard coding...
1875  */
1876 int
1877 in6_matchlen(src, dst)
1878 struct in6_addr *src, *dst;
1879 {
1880 	int match = 0;
1881 	u_char *s = (u_char *)src, *d = (u_char *)dst;
1882 	u_char *lim = s + 16, r;
1883 
1884 	while (s < lim)
1885 		if ((r = (*d++ ^ *s++)) != 0) {
1886 			while (r < 128) {
1887 				match++;
1888 				r <<= 1;
1889 			}
1890 			break;
1891 		} else
1892 			match += 8;
1893 	return match;
1894 }
1895 
1896 /* XXX: to be scope conscious */
1897 int
1898 in6_are_prefix_equal(p1, p2, len)
1899 	struct in6_addr *p1, *p2;
1900 	int len;
1901 {
1902 	int bytelen, bitlen;
1903 
1904 	/* sanity check */
1905 	if (0 > len || len > 128) {
1906 		log(LOG_ERR, "in6_are_prefix_equal: invalid prefix length(%d)\n",
1907 		    len);
1908 		return(0);
1909 	}
1910 
1911 	bytelen = len / 8;
1912 	bitlen = len % 8;
1913 
1914 	if (bcmp(&p1->s6_addr, &p2->s6_addr, bytelen))
1915 		return(0);
1916 	if (p1->s6_addr[bytelen] >> (8 - bitlen) !=
1917 	    p2->s6_addr[bytelen] >> (8 - bitlen))
1918 		return(0);
1919 
1920 	return(1);
1921 }
1922 
1923 void
1924 in6_prefixlen2mask(maskp, len)
1925 	struct in6_addr *maskp;
1926 	int len;
1927 {
1928 	u_char maskarray[8] = {0x80, 0xc0, 0xe0, 0xf0, 0xf8, 0xfc, 0xfe, 0xff};
1929 	int bytelen, bitlen, i;
1930 
1931 	/* sanity check */
1932 	if (0 > len || len > 128) {
1933 		log(LOG_ERR, "in6_prefixlen2mask: invalid prefix length(%d)\n",
1934 		    len);
1935 		return;
1936 	}
1937 
1938 	bzero(maskp, sizeof(*maskp));
1939 	bytelen = len / 8;
1940 	bitlen = len % 8;
1941 	for (i = 0; i < bytelen; i++)
1942 		maskp->s6_addr[i] = 0xff;
1943 	if (bitlen)
1944 		maskp->s6_addr[bytelen] = maskarray[bitlen - 1];
1945 }
1946 
1947 /*
1948  * return the best address out of the same scope
1949  */
1950 struct in6_ifaddr *
1951 in6_ifawithscope(oifp, dst)
1952 	struct ifnet *oifp;
1953 	struct in6_addr *dst;
1954 {
1955 	int dst_scope =	in6_addrscope(dst), src_scope, best_scope = 0;
1956 	int blen = -1;
1957 	struct ifaddr *ifa;
1958 	struct ifnet *ifp;
1959 	struct in6_ifaddr *ifa_best = NULL;
1960 
1961 	if (oifp == NULL) {
1962 #if 0
1963 		printf("in6_ifawithscope: output interface is not specified\n");
1964 #endif
1965 		return(NULL);
1966 	}
1967 
1968 	/*
1969 	 * We search for all addresses on all interfaces from the beginning.
1970 	 * Comparing an interface with the outgoing interface will be done
1971 	 * only at the final stage of tiebreaking.
1972 	 */
1973 	for (ifp = TAILQ_FIRST(&ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list))
1974 	{
1975 		/*
1976 		 * We can never take an address that breaks the scope zone
1977 		 * of the destination.
1978 		 */
1979 		if (in6_addr2scopeid(ifp, dst) != in6_addr2scopeid(oifp, dst))
1980 			continue;
1981 
1982 		TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list)
1983 		{
1984 			int tlen = -1, dscopecmp, bscopecmp, matchcmp;
1985 
1986 			if (ifa->ifa_addr->sa_family != AF_INET6)
1987 				continue;
1988 
1989 			src_scope = in6_addrscope(IFA_IN6(ifa));
1990 
1991 			/*
1992 			 * Don't use an address before completing DAD
1993 			 * nor a duplicated address.
1994 			 */
1995 			if (((struct in6_ifaddr *)ifa)->ia6_flags &
1996 			    IN6_IFF_NOTREADY)
1997 				continue;
1998 
1999 			/* XXX: is there any case to allow anycasts? */
2000 			if (((struct in6_ifaddr *)ifa)->ia6_flags &
2001 			    IN6_IFF_ANYCAST)
2002 				continue;
2003 
2004 			if (((struct in6_ifaddr *)ifa)->ia6_flags &
2005 			    IN6_IFF_DETACHED)
2006 				continue;
2007 
2008 			/*
2009 			 * If this is the first address we find,
2010 			 * keep it anyway.
2011 			 */
2012 			if (ifa_best == NULL)
2013 				goto replace;
2014 
2015 			/*
2016 			 * ifa_best is never NULL beyond this line except
2017 			 * within the block labeled "replace".
2018 			 */
2019 
2020 			/*
2021 			 * If ifa_best has a smaller scope than dst and
2022 			 * the current address has a larger one than
2023 			 * (or equal to) dst, always replace ifa_best.
2024 			 * Also, if the current address has a smaller scope
2025 			 * than dst, ignore it unless ifa_best also has a
2026 			 * smaller scope.
2027 			 * Consequently, after the two if-clause below,
2028 			 * the followings must be satisfied:
2029 			 * (scope(src) < scope(dst) &&
2030 			 *  scope(best) < scope(dst))
2031 			 *  OR
2032 			 * (scope(best) >= scope(dst) &&
2033 			 *  scope(src) >= scope(dst))
2034 			 */
2035 			if (IN6_ARE_SCOPE_CMP(best_scope, dst_scope) < 0 &&
2036 			    IN6_ARE_SCOPE_CMP(src_scope, dst_scope) >= 0)
2037 				goto replace; /* (A) */
2038 			if (IN6_ARE_SCOPE_CMP(src_scope, dst_scope) < 0 &&
2039 			    IN6_ARE_SCOPE_CMP(best_scope, dst_scope) >= 0)
2040 				continue; /* (B) */
2041 
2042 			/*
2043 			 * A deprecated address SHOULD NOT be used in new
2044 			 * communications if an alternate (non-deprecated)
2045 			 * address is available and has sufficient scope.
2046 			 * RFC 2462, Section 5.5.4.
2047 			 */
2048 			if (((struct in6_ifaddr *)ifa)->ia6_flags &
2049 			    IN6_IFF_DEPRECATED) {
2050 				/*
2051 				 * Ignore any deprecated addresses if
2052 				 * specified by configuration.
2053 				 */
2054 				if (!ip6_use_deprecated)
2055 					continue;
2056 
2057 				/*
2058 				 * If we have already found a non-deprecated
2059 				 * candidate, just ignore deprecated addresses.
2060 				 */
2061 				if ((ifa_best->ia6_flags & IN6_IFF_DEPRECATED)
2062 				    == 0)
2063 					continue;
2064 			}
2065 
2066 			/*
2067 			 * A non-deprecated address is always preferred
2068 			 * to a deprecated one regardless of scopes and
2069 			 * address matching (Note invariants ensured by the
2070 			 * conditions (A) and (B) above.)
2071 			 */
2072 			if ((ifa_best->ia6_flags & IN6_IFF_DEPRECATED) &&
2073 			    (((struct in6_ifaddr *)ifa)->ia6_flags &
2074 			     IN6_IFF_DEPRECATED) == 0)
2075 				goto replace;
2076 
2077 			/*
2078 			 * When we use temporary addresses described in
2079 			 * RFC 3041, we prefer temporary addresses to
2080 			 * public autoconf addresses.  Again, note the
2081 			 * invariants from (A) and (B).  Also note that we
2082 			 * don't have any preference between static addresses
2083 			 * and autoconf addresses (despite of whether or not
2084 			 * the latter is temporary or public.)
2085 			 */
2086 			if (ip6_use_tempaddr) {
2087 				struct in6_ifaddr *ifat;
2088 
2089 				ifat = (struct in6_ifaddr *)ifa;
2090 				if ((ifa_best->ia6_flags &
2091 				     (IN6_IFF_AUTOCONF|IN6_IFF_TEMPORARY))
2092 				     == IN6_IFF_AUTOCONF &&
2093 				    (ifat->ia6_flags &
2094 				     (IN6_IFF_AUTOCONF|IN6_IFF_TEMPORARY))
2095 				     == (IN6_IFF_AUTOCONF|IN6_IFF_TEMPORARY)) {
2096 					goto replace;
2097 				}
2098 				if ((ifa_best->ia6_flags &
2099 				     (IN6_IFF_AUTOCONF|IN6_IFF_TEMPORARY))
2100 				    == (IN6_IFF_AUTOCONF|IN6_IFF_TEMPORARY) &&
2101 				    (ifat->ia6_flags &
2102 				     (IN6_IFF_AUTOCONF|IN6_IFF_TEMPORARY))
2103 				     == IN6_IFF_AUTOCONF) {
2104 					continue;
2105 				}
2106 			}
2107 
2108 			/*
2109 			 * At this point, we have two cases:
2110 			 * 1. we are looking at a non-deprecated address,
2111 			 *    and ifa_best is also non-deprecated.
2112 			 * 2. we are looking at a deprecated address,
2113 			 *    and ifa_best is also deprecated.
2114 			 * Also, we do not have to consider a case where
2115 			 * the scope of if_best is larger(smaller) than dst and
2116 			 * the scope of the current address is smaller(larger)
2117 			 * than dst. Such a case has already been covered.
2118 			 * Tiebreaking is done according to the following
2119 			 * items:
2120 			 * - the scope comparison between the address and
2121 			 *   dst (dscopecmp)
2122 			 * - the scope comparison between the address and
2123 			 *   ifa_best (bscopecmp)
2124 			 * - if the address match dst longer than ifa_best
2125 			 *   (matchcmp)
2126 			 * - if the address is on the outgoing I/F (outI/F)
2127 			 *
2128 			 * Roughly speaking, the selection policy is
2129 			 * - the most important item is scope. The same scope
2130 			 *   is best. Then search for a larger scope.
2131 			 *   Smaller scopes are the last resort.
2132 			 * - A deprecated address is chosen only when we have
2133 			 *   no address that has an enough scope, but is
2134 			 *   prefered to any addresses of smaller scopes
2135 			 *   (this must be already done above.)
2136 			 * - addresses on the outgoing I/F are preferred to
2137 			 *   ones on other interfaces if none of above
2138 			 *   tiebreaks.  In the table below, the column "bI"
2139 			 *   means if the best_ifa is on the outgoing
2140 			 *   interface, and the column "sI" means if the ifa
2141 			 *   is on the outgoing interface.
2142 			 * - If there is no other reasons to choose one,
2143 			 *   longest address match against dst is considered.
2144 			 *
2145 			 * The precise decision table is as follows:
2146 			 * dscopecmp bscopecmp    match  bI oI | replace?
2147 			 *       N/A     equal      N/A   Y  N |   No (1)
2148 			 *       N/A     equal      N/A   N  Y |  Yes (2)
2149 			 *       N/A     equal   larger    N/A |  Yes (3)
2150 			 *       N/A     equal  !larger    N/A |   No (4)
2151 			 *    larger    larger      N/A    N/A |   No (5)
2152 			 *    larger   smaller      N/A    N/A |  Yes (6)
2153 			 *   smaller    larger      N/A    N/A |  Yes (7)
2154 			 *   smaller   smaller      N/A    N/A |   No (8)
2155 			 *     equal   smaller      N/A    N/A |  Yes (9)
2156 			 *     equal    larger       (already done at A above)
2157 			 */
2158 			dscopecmp = IN6_ARE_SCOPE_CMP(src_scope, dst_scope);
2159 			bscopecmp = IN6_ARE_SCOPE_CMP(src_scope, best_scope);
2160 
2161 			if (bscopecmp == 0) {
2162 				struct ifnet *bifp = ifa_best->ia_ifp;
2163 
2164 				if (bifp == oifp && ifp != oifp) /* (1) */
2165 					continue;
2166 				if (bifp != oifp && ifp == oifp) /* (2) */
2167 					goto replace;
2168 
2169 				/*
2170 				 * Both bifp and ifp are on the outgoing
2171 				 * interface, or both two are on a different
2172 				 * interface from the outgoing I/F.
2173 				 * now we need address matching against dst
2174 				 * for tiebreaking.
2175 				 */
2176 				tlen = in6_matchlen(IFA_IN6(ifa), dst);
2177 				matchcmp = tlen - blen;
2178 				if (matchcmp > 0) /* (3) */
2179 					goto replace;
2180 				continue; /* (4) */
2181 			}
2182 			if (dscopecmp > 0) {
2183 				if (bscopecmp > 0) /* (5) */
2184 					continue;
2185 				goto replace; /* (6) */
2186 			}
2187 			if (dscopecmp < 0) {
2188 				if (bscopecmp > 0) /* (7) */
2189 					goto replace;
2190 				continue; /* (8) */
2191 			}
2192 
2193 			/* now dscopecmp must be 0 */
2194 			if (bscopecmp < 0)
2195 				goto replace; /* (9) */
2196 
2197 		  replace:
2198 			ifa_best = (struct in6_ifaddr *)ifa;
2199 			blen = tlen >= 0 ? tlen :
2200 				in6_matchlen(IFA_IN6(ifa), dst);
2201 			best_scope = in6_addrscope(&ifa_best->ia_addr.sin6_addr);
2202 		}
2203 	}
2204 
2205 	/* count statistics for future improvements */
2206 	if (ifa_best == NULL)
2207 		ip6stat.ip6s_sources_none++;
2208 	else {
2209 		if (oifp == ifa_best->ia_ifp)
2210 			ip6stat.ip6s_sources_sameif[best_scope]++;
2211 		else
2212 			ip6stat.ip6s_sources_otherif[best_scope]++;
2213 
2214 		if (best_scope == dst_scope)
2215 			ip6stat.ip6s_sources_samescope[best_scope]++;
2216 		else
2217 			ip6stat.ip6s_sources_otherscope[best_scope]++;
2218 
2219 		if ((ifa_best->ia6_flags & IN6_IFF_DEPRECATED) != 0)
2220 			ip6stat.ip6s_sources_deprecated[best_scope]++;
2221 	}
2222 
2223 	return(ifa_best);
2224 }
2225 
2226 /*
2227  * return the best address out of the same scope. if no address was
2228  * found, return the first valid address from designated IF.
2229  */
2230 struct in6_ifaddr *
2231 in6_ifawithifp(ifp, dst)
2232 	struct ifnet *ifp;
2233 	struct in6_addr *dst;
2234 {
2235 	int dst_scope =	in6_addrscope(dst), blen = -1, tlen;
2236 	struct ifaddr *ifa;
2237 	struct in6_ifaddr *besta = 0;
2238 	struct in6_ifaddr *dep[2];	/*last-resort: deprecated*/
2239 
2240 	dep[0] = dep[1] = NULL;
2241 
2242 	/*
2243 	 * We first look for addresses in the same scope.
2244 	 * If there is one, return it.
2245 	 * If two or more, return one which matches the dst longest.
2246 	 * If none, return one of global addresses assigned other ifs.
2247 	 */
2248 	TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list)
2249 	{
2250 		if (ifa->ifa_addr->sa_family != AF_INET6)
2251 			continue;
2252 		if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST)
2253 			continue; /* XXX: is there any case to allow anycast? */
2254 		if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_NOTREADY)
2255 			continue; /* don't use this interface */
2256 		if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DETACHED)
2257 			continue;
2258 		if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DEPRECATED) {
2259 			if (ip6_use_deprecated)
2260 				dep[0] = (struct in6_ifaddr *)ifa;
2261 			continue;
2262 		}
2263 
2264 		if (dst_scope == in6_addrscope(IFA_IN6(ifa))) {
2265 			/*
2266 			 * call in6_matchlen() as few as possible
2267 			 */
2268 			if (besta) {
2269 				if (blen == -1)
2270 					blen = in6_matchlen(&besta->ia_addr.sin6_addr, dst);
2271 				tlen = in6_matchlen(IFA_IN6(ifa), dst);
2272 				if (tlen > blen) {
2273 					blen = tlen;
2274 					besta = (struct in6_ifaddr *)ifa;
2275 				}
2276 			} else
2277 				besta = (struct in6_ifaddr *)ifa;
2278 		}
2279 	}
2280 	if (besta)
2281 		return(besta);
2282 
2283 	TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list)
2284 	{
2285 		if (ifa->ifa_addr->sa_family != AF_INET6)
2286 			continue;
2287 		if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST)
2288 			continue; /* XXX: is there any case to allow anycast? */
2289 		if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_NOTREADY)
2290 			continue; /* don't use this interface */
2291 		if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DETACHED)
2292 			continue;
2293 		if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DEPRECATED) {
2294 			if (ip6_use_deprecated)
2295 				dep[1] = (struct in6_ifaddr *)ifa;
2296 			continue;
2297 		}
2298 
2299 		return (struct in6_ifaddr *)ifa;
2300 	}
2301 
2302 	/* use the last-resort values, that are, deprecated addresses */
2303 	if (dep[0])
2304 		return dep[0];
2305 	if (dep[1])
2306 		return dep[1];
2307 
2308 	return NULL;
2309 }
2310 
2311 /*
2312  * perform DAD when interface becomes IFF_UP.
2313  */
2314 void
2315 in6_if_up(ifp)
2316 	struct ifnet *ifp;
2317 {
2318 	struct ifaddr *ifa;
2319 	struct in6_ifaddr *ia;
2320 	int dad_delay;		/* delay ticks before DAD output */
2321 
2322 	/*
2323 	 * special cases, like 6to4, are handled in in6_ifattach
2324 	 */
2325 	in6_ifattach(ifp, NULL);
2326 
2327 	dad_delay = 0;
2328 	TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list)
2329 	{
2330 		if (ifa->ifa_addr->sa_family != AF_INET6)
2331 			continue;
2332 		ia = (struct in6_ifaddr *)ifa;
2333 		if (ia->ia6_flags & IN6_IFF_TENTATIVE)
2334 			nd6_dad_start(ifa, &dad_delay);
2335 	}
2336 }
2337 
2338 int
2339 in6if_do_dad(ifp)
2340 	struct ifnet *ifp;
2341 {
2342 	if ((ifp->if_flags & IFF_LOOPBACK) != 0)
2343 		return(0);
2344 
2345 	switch (ifp->if_type) {
2346 #ifdef IFT_DUMMY
2347 	case IFT_DUMMY:
2348 #endif
2349 	case IFT_FAITH:
2350 		/*
2351 		 * These interfaces do not have the IFF_LOOPBACK flag,
2352 		 * but loop packets back.  We do not have to do DAD on such
2353 		 * interfaces.  We should even omit it, because loop-backed
2354 		 * NS would confuse the DAD procedure.
2355 		 */
2356 		return(0);
2357 	default:
2358 		/*
2359 		 * Our DAD routine requires the interface up and running.
2360 		 * However, some interfaces can be up before the RUNNING
2361 		 * status.  Additionaly, users may try to assign addresses
2362 		 * before the interface becomes up (or running).
2363 		 * We simply skip DAD in such a case as a work around.
2364 		 * XXX: we should rather mark "tentative" on such addresses,
2365 		 * and do DAD after the interface becomes ready.
2366 		 */
2367 		if ((ifp->if_flags & (IFF_UP|IFF_RUNNING)) !=
2368 		    (IFF_UP|IFF_RUNNING))
2369 			return(0);
2370 
2371 		return(1);
2372 	}
2373 }
2374 
2375 /*
2376  * Calculate max IPv6 MTU through all the interfaces and store it
2377  * to in6_maxmtu.
2378  */
2379 void
2380 in6_setmaxmtu()
2381 {
2382 	unsigned long maxmtu = 0;
2383 	struct ifnet *ifp;
2384 
2385 	for (ifp = TAILQ_FIRST(&ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list))
2386 	{
2387 		if ((ifp->if_flags & IFF_LOOPBACK) == 0 &&
2388 		    nd_ifinfo[ifp->if_index].linkmtu > maxmtu)
2389 			maxmtu =  nd_ifinfo[ifp->if_index].linkmtu;
2390 	}
2391 	if (maxmtu)	/* update only when maxmtu is positive */
2392 		in6_maxmtu = maxmtu;
2393 }
2394 
2395 /*
2396  * Convert sockaddr_in6 to sockaddr_in. Original sockaddr_in6 must be
2397  * v4 mapped addr or v4 compat addr
2398  */
2399 void
2400 in6_sin6_2_sin(struct sockaddr_in *sin, struct sockaddr_in6 *sin6)
2401 {
2402 	bzero(sin, sizeof(*sin));
2403 	sin->sin_len = sizeof(struct sockaddr_in);
2404 	sin->sin_family = AF_INET;
2405 	sin->sin_port = sin6->sin6_port;
2406 	sin->sin_addr.s_addr = sin6->sin6_addr.s6_addr32[3];
2407 }
2408 
2409 /* Convert sockaddr_in to sockaddr_in6 in v4 mapped addr format. */
2410 void
2411 in6_sin_2_v4mapsin6(struct sockaddr_in *sin, struct sockaddr_in6 *sin6)
2412 {
2413 	bzero(sin6, sizeof(*sin6));
2414 	sin6->sin6_len = sizeof(struct sockaddr_in6);
2415 	sin6->sin6_family = AF_INET6;
2416 	sin6->sin6_port = sin->sin_port;
2417 	sin6->sin6_addr.s6_addr32[0] = 0;
2418 	sin6->sin6_addr.s6_addr32[1] = 0;
2419 	sin6->sin6_addr.s6_addr32[2] = IPV6_ADDR_INT32_SMP;
2420 	sin6->sin6_addr.s6_addr32[3] = sin->sin_addr.s_addr;
2421 }
2422 
2423 /* Convert sockaddr_in6 into sockaddr_in. */
2424 void
2425 in6_sin6_2_sin_in_sock(struct sockaddr *nam)
2426 {
2427 	struct sockaddr_in *sin_p;
2428 	struct sockaddr_in6 sin6;
2429 
2430 	/*
2431 	 * Save original sockaddr_in6 addr and convert it
2432 	 * to sockaddr_in.
2433 	 */
2434 	sin6 = *(struct sockaddr_in6 *)nam;
2435 	sin_p = (struct sockaddr_in *)nam;
2436 	in6_sin6_2_sin(sin_p, &sin6);
2437 }
2438 
2439 /* Convert sockaddr_in into sockaddr_in6 in v4 mapped addr format. */
2440 void
2441 in6_sin_2_v4mapsin6_in_sock(struct sockaddr **nam)
2442 {
2443 	struct sockaddr_in *sin_p;
2444 	struct sockaddr_in6 *sin6_p;
2445 
2446 	MALLOC(sin6_p, struct sockaddr_in6 *, sizeof *sin6_p, M_SONAME,
2447 	       M_WAITOK);
2448 	sin_p = (struct sockaddr_in *)*nam;
2449 	in6_sin_2_v4mapsin6(sin_p, sin6_p);
2450 	FREE(*nam, M_SONAME);
2451 	*nam = (struct sockaddr *)sin6_p;
2452 }
2453