xref: /freebsd/sys/netinet6/in6.c (revision 77a0943ded95b9e6438f7db70c4a28e4d93946d4)
1 /*	$FreeBSD$	*/
2 /*	$KAME: in6.c,v 1.99 2000/07/11 17:00:58 jinmei 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 
92 #include <netinet6/nd6.h>
93 #include <netinet/ip6.h>
94 #include <netinet6/ip6_var.h>
95 #include <netinet6/mld6_var.h>
96 #include <netinet6/ip6_mroute.h>
97 #include <netinet6/in6_ifattach.h>
98 #include <netinet6/scope6_var.h>
99 
100 #include "gif.h"
101 #if NGIF > 0
102 #include <net/if_gif.h>
103 #endif
104 
105 #include <net/net_osdep.h>
106 
107 MALLOC_DEFINE(M_IPMADDR, "in6_multi", "internet multicast address");
108 
109 /*
110  * Definitions of some costant IP6 addresses.
111  */
112 const struct in6_addr in6addr_any = IN6ADDR_ANY_INIT;
113 const struct in6_addr in6addr_loopback = IN6ADDR_LOOPBACK_INIT;
114 const struct in6_addr in6addr_nodelocal_allnodes =
115 	IN6ADDR_NODELOCAL_ALLNODES_INIT;
116 const struct in6_addr in6addr_linklocal_allnodes =
117 	IN6ADDR_LINKLOCAL_ALLNODES_INIT;
118 const struct in6_addr in6addr_linklocal_allrouters =
119 	IN6ADDR_LINKLOCAL_ALLROUTERS_INIT;
120 
121 const struct in6_addr in6mask0 = IN6MASK0;
122 const struct in6_addr in6mask32 = IN6MASK32;
123 const struct in6_addr in6mask64 = IN6MASK64;
124 const struct in6_addr in6mask96 = IN6MASK96;
125 const struct in6_addr in6mask128 = IN6MASK128;
126 
127 static int in6_lifaddr_ioctl __P((struct socket *, u_long, caddr_t,
128 	struct ifnet *, struct proc *));
129 
130 struct in6_multihead in6_multihead;	/* XXX BSS initialization */
131 
132 /*
133  * Check if the loopback entry will be automatically generated.
134  *   if 0 returned, will not be automatically generated.
135  *   if 1 returned, will be automatically generated.
136  */
137 static int
138 in6_is_ifloop_auto(struct ifaddr *ifa)
139 {
140 #define SIN6(s) ((struct sockaddr_in6 *)s)
141 	/*
142 	 * If RTF_CLONING is unset, or (IFF_LOOPBACK | IFF_POINTOPOINT),
143 	 * or netmask is all0 or all1, then cloning will not happen,
144 	 * then we can't rely on its loopback entry generation.
145 	 */
146 	if ((ifa->ifa_flags & RTF_CLONING) == 0 ||
147 	    (ifa->ifa_ifp->if_flags & (IFF_LOOPBACK | IFF_POINTOPOINT)) ||
148 	    (SIN6(ifa->ifa_netmask)->sin6_len == sizeof(struct sockaddr_in6)
149 	     &&
150 	     IN6_ARE_ADDR_EQUAL(&SIN6(ifa->ifa_netmask)->sin6_addr,
151 				&in6mask128)) ||
152 	    ((struct sockaddr_in6 *)ifa->ifa_netmask)->sin6_len == 0)
153 		return 0;
154 	else
155 		return 1;
156 #undef SIN6
157 }
158 
159 /*
160  * Subroutine for in6_ifaddloop() and in6_ifremloop().
161  * This routine does actual work.
162  */
163 static void
164 in6_ifloop_request(int cmd, struct ifaddr *ifa)
165 {
166 	struct sockaddr_in6 lo_sa;
167 	struct sockaddr_in6 all1_sa;
168 	struct rtentry *nrt = NULL, **nrtp = NULL;
169 
170 	bzero(&lo_sa, sizeof(lo_sa));
171 	bzero(&all1_sa, sizeof(all1_sa));
172 	lo_sa.sin6_family = AF_INET6;
173 	lo_sa.sin6_len = sizeof(struct sockaddr_in6);
174 	all1_sa = lo_sa;
175 	lo_sa.sin6_addr = in6addr_loopback;
176 	all1_sa.sin6_addr = in6mask128;
177 
178 	/*
179 	 * So we add or remove static loopback entry, here.
180 	 * This request for deletion could fail, e.g. when we remove
181 	 * an address right after adding it.
182 	 */
183 	if (cmd == RTM_ADD)
184 		nrtp = &nrt;
185 	rtrequest(cmd, ifa->ifa_addr,
186 		  (struct sockaddr *)&lo_sa,
187 		  (struct sockaddr *)&all1_sa,
188 		  RTF_UP|RTF_HOST, nrtp);
189 
190 	/*
191 	 * Make sure rt_ifa be equal to IFA, the second argument of the
192 	 * function.
193 	 * We need this because when we refer rt_ifa->ia6_flags in ip6_input,
194 	 * we assume that the rt_ifa points to the address instead of the
195 	 * loopback address.
196 	 */
197 	if (cmd == RTM_ADD && nrt && ifa != nrt->rt_ifa) {
198 		IFAFREE(nrt->rt_ifa);
199 		ifa->ifa_refcnt++;
200 		nrt->rt_ifa = ifa;
201 	}
202 	if (nrt)
203 		nrt->rt_refcnt--;
204 }
205 
206 /*
207  * Add ownaddr as loopback rtentry, if necessary(ex. on p2p link).
208  * Because, KAME needs loopback rtentry for ownaddr check in
209  * ip6_input().
210  */
211 static void
212 in6_ifaddloop(struct ifaddr *ifa)
213 {
214 	if (!in6_is_ifloop_auto(ifa)) {
215 		struct rtentry *rt;
216 
217 		/* If there is no loopback entry, allocate one. */
218 		rt = rtalloc1(ifa->ifa_addr, 0, 0);
219 		if (rt == 0 || (rt->rt_ifp->if_flags & IFF_LOOPBACK) == 0)
220 			in6_ifloop_request(RTM_ADD, ifa);
221 		if (rt)
222 			rt->rt_refcnt--;
223 	}
224 }
225 
226 /*
227  * Remove loopback rtentry of ownaddr generated by in6_ifaddloop(),
228  * if it exists.
229  */
230 static void
231 in6_ifremloop(struct ifaddr *ifa)
232 {
233 	struct in6_ifaddr *ia;
234 	int ia_count = 0;
235 
236 	/*
237 	 * All BSD variants except BSD/OS do not remove cloned routes
238 	 * from an interface direct route, when removing the direct route
239 	 * (see commens in net/net_osdep.h).
240 	 * So we should remove the route corresponding to the deleted address
241 	 * regardless of the result of in6_is_ifloop_auto().
242 	 */
243 	if (1)
244 	{
245 		/* If only one ifa for the loopback entry, delete it. */
246 		for (ia = in6_ifaddr; ia; ia = ia->ia_next) {
247 			if (IN6_ARE_ADDR_EQUAL(IFA_IN6(ifa),
248 					       &ia->ia_addr.sin6_addr)) {
249 				ia_count++;
250 				if (ia_count > 1)
251 					break;
252 			}
253 		}
254 		if (ia_count == 1)
255 			in6_ifloop_request(RTM_DELETE, ifa);
256 	}
257 }
258 
259 int
260 in6_ifindex2scopeid(idx)
261 	int idx;
262 {
263 	struct ifnet *ifp;
264 	struct ifaddr *ifa;
265 	struct sockaddr_in6 *sin6;
266 
267 	if (idx < 0 || if_index < idx)
268 		return -1;
269 	ifp = ifindex2ifnet[idx];
270 
271 	TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list)
272 	{
273 		if (ifa->ifa_addr->sa_family != AF_INET6)
274 			continue;
275 		sin6 = (struct sockaddr_in6 *)ifa->ifa_addr;
276 		if (IN6_IS_ADDR_SITELOCAL(&sin6->sin6_addr))
277 			return sin6->sin6_scope_id & 0xffff;
278 	}
279 
280 	return -1;
281 }
282 
283 int
284 in6_mask2len(mask)
285 	struct in6_addr *mask;
286 {
287 	int x, y;
288 
289 	for (x = 0; x < sizeof(*mask); x++) {
290 		if (mask->s6_addr8[x] != 0xff)
291 			break;
292 	}
293 	y = 0;
294 	if (x < sizeof(*mask)) {
295 		for (y = 0; y < 8; y++) {
296 			if ((mask->s6_addr8[x] & (0x80 >> y)) == 0)
297 				break;
298 		}
299 	}
300 	return x * 8 + y;
301 }
302 
303 void
304 in6_len2mask(mask, len)
305 	struct in6_addr *mask;
306 	int len;
307 {
308 	int i;
309 
310 	bzero(mask, sizeof(*mask));
311 	for (i = 0; i < len / 8; i++)
312 		mask->s6_addr8[i] = 0xff;
313 	if (len % 8)
314 		mask->s6_addr8[i] = (0xff00 >> (len % 8)) & 0xff;
315 }
316 
317 #define ifa2ia6(ifa)	((struct in6_ifaddr *)(ifa))
318 #define ia62ifa(ia6)	(&((ia6)->ia_ifa))
319 
320 int
321 in6_control(so, cmd, data, ifp, p)
322 	struct	socket *so;
323 	u_long cmd;
324 	caddr_t	data;
325 	struct ifnet *ifp;
326 	struct proc *p;
327 {
328 	struct	in6_ifreq *ifr = (struct in6_ifreq *)data;
329 	struct	in6_ifaddr *ia = NULL, *oia;
330 	struct	in6_aliasreq *ifra = (struct in6_aliasreq *)data;
331 	struct	sockaddr_in6 oldaddr;
332 #ifdef COMPAT_IN6IFIOCTL
333 	struct	sockaddr_in6 net;
334 #endif
335 	int error = 0, hostIsNew, prefixIsNew;
336 	int newifaddr;
337 	int privileged;
338 
339 	privileged = 0;
340 	if (p == NULL || !suser(p))
341 		privileged++;
342 
343 	/*
344 	 * xxx should prevent processes for link-local addresses?
345 	 */
346 #if NGIF > 0
347 	if (ifp && ifp->if_type == IFT_GIF) {
348 		switch (cmd) {
349 		case SIOCSIFPHYADDR_IN6:
350 			if (!privileged)
351 				return(EPERM);
352 			/*fall through*/
353 		case SIOCGIFPSRCADDR_IN6:
354 		case SIOCGIFPDSTADDR_IN6:
355 			return gif_ioctl(ifp, cmd, data);
356 		}
357 	}
358 #endif
359 	switch (cmd) {
360 	case SIOCGETSGCNT_IN6:
361 	case SIOCGETMIFCNT_IN6:
362 		return (mrt6_ioctl(cmd, data));
363 	}
364 
365 	if (ifp == NULL)
366 		return(EOPNOTSUPP);
367 
368 	switch (cmd) {
369 	case SIOCSNDFLUSH_IN6:
370 	case SIOCSPFXFLUSH_IN6:
371 	case SIOCSRTRFLUSH_IN6:
372 	case SIOCSDEFIFACE_IN6:
373 	case SIOCSIFINFO_FLAGS:
374 		if (!privileged)
375 			return(EPERM);
376 		/*fall through*/
377 	case SIOCGIFINFO_IN6:
378 	case SIOCGDRLST_IN6:
379 	case SIOCGPRLST_IN6:
380 	case SIOCGNBRINFO_IN6:
381 	case SIOCGDEFIFACE_IN6:
382 		return(nd6_ioctl(cmd, data, ifp));
383 	}
384 
385 	switch (cmd) {
386 	case SIOCSIFPREFIX_IN6:
387 	case SIOCDIFPREFIX_IN6:
388 	case SIOCAIFPREFIX_IN6:
389 	case SIOCCIFPREFIX_IN6:
390 	case SIOCSGIFPREFIX_IN6:
391 		if (!privileged)
392 			return(EPERM);
393 		/*fall through*/
394 	case SIOCGIFPREFIX_IN6:
395 		if (ip6_forwarding == 0)
396 			return(EPERM);
397 		return(in6_prefix_ioctl(so, cmd, data, ifp));
398 	}
399 
400 	switch(cmd) {
401 	case SIOCSSCOPE6:
402 		if (!privileged)
403 			return(EPERM);
404 		return(scope6_set(ifp, ifr->ifr_ifru.ifru_scope_id));
405 		break;
406 	case SIOCGSCOPE6:
407 		return(scope6_get(ifp, ifr->ifr_ifru.ifru_scope_id));
408 		break;
409 	case SIOCGSCOPE6DEF:
410 		return(scope6_get_default(ifr->ifr_ifru.ifru_scope_id));
411 		break;
412 	}
413 
414 	switch (cmd) {
415 	case SIOCALIFADDR:
416 	case SIOCDLIFADDR:
417 		if (!privileged)
418 			return(EPERM);
419 		/*fall through*/
420 	case SIOCGLIFADDR:
421 		return in6_lifaddr_ioctl(so, cmd, data, ifp, p);
422 	}
423 
424 	/*
425 	 * Find address for this interface, if it exists.
426 	 */
427 	if (ifra->ifra_addr.sin6_family == AF_INET6) { /* XXX */
428 		struct sockaddr_in6 *sa6 =
429 			(struct sockaddr_in6 *)&ifra->ifra_addr;
430 
431 		if (IN6_IS_ADDR_LINKLOCAL(&sa6->sin6_addr)) {
432 			if (sa6->sin6_addr.s6_addr16[1] == 0) {
433 				/* interface ID is not embedded by the user */
434 				sa6->sin6_addr.s6_addr16[1] =
435 					htons(ifp->if_index);
436 			} else if (sa6->sin6_addr.s6_addr16[1] !=
437 				    htons(ifp->if_index)) {
438 				return(EINVAL);	/* ifid is contradict */
439 			}
440 			if (sa6->sin6_scope_id) {
441 				if (sa6->sin6_scope_id !=
442 				    (u_int32_t)ifp->if_index)
443 					return(EINVAL);
444 				sa6->sin6_scope_id = 0; /* XXX: good way? */
445 			}
446 		}
447 		ia = in6ifa_ifpwithaddr(ifp, &ifra->ifra_addr.sin6_addr);
448 	}
449 
450 	switch (cmd) {
451 
452 	case SIOCDIFADDR_IN6:
453 		/*
454 		 * for IPv4, we look for existing in6_ifaddr here to allow
455 		 * "ifconfig if0 delete" to remove first IPv4 address on the
456 		 * interface.  For IPv6, as the spec allow multiple interface
457 		 * address from the day one, we consider "remove the first one"
458 		 * semantics to be not preferrable.
459 		 */
460 		if (ia == NULL)
461 			return(EADDRNOTAVAIL);
462 		/* FALLTHROUGH */
463 	case SIOCAIFADDR_IN6:
464 	case SIOCSIFADDR_IN6:
465 #ifdef COMPAT_IN6IFIOCTL
466 	case SIOCSIFDSTADDR_IN6:
467 	case SIOCSIFNETMASK_IN6:
468 		/*
469 		 * Since IPv6 allows a node to assign multiple addresses
470 		 * on a single interface, SIOCSIFxxx ioctls are not suitable
471 		 * and should be unused.
472 		 */
473 #endif
474 		if (ifra->ifra_addr.sin6_family != AF_INET6)
475 			return(EAFNOSUPPORT);
476 		if (!privileged)
477 			return(EPERM);
478 		if (ia == NULL) {
479 			ia = (struct in6_ifaddr *)
480 				malloc(sizeof(*ia), M_IFADDR, M_WAITOK);
481 			if (ia == NULL)
482 				return (ENOBUFS);
483 			bzero((caddr_t)ia, sizeof(*ia));
484 			/* Initialize the address and masks */
485 			ia->ia_ifa.ifa_addr = (struct sockaddr *)&ia->ia_addr;
486 			ia->ia_addr.sin6_family = AF_INET6;
487 			ia->ia_addr.sin6_len = sizeof(ia->ia_addr);
488 #if 1
489 			if (ifp->if_flags & IFF_POINTOPOINT) {
490 				ia->ia_ifa.ifa_dstaddr
491 					= (struct sockaddr *)&ia->ia_dstaddr;
492 				ia->ia_dstaddr.sin6_family = AF_INET6;
493 				ia->ia_dstaddr.sin6_len = sizeof(ia->ia_dstaddr);
494 			} else {
495 				ia->ia_ifa.ifa_dstaddr = NULL;
496 				bzero(&ia->ia_dstaddr, sizeof(ia->ia_dstaddr));
497 			}
498 #else  /* always initilize by NULL */
499 			ia->ia_ifa.ifa_dstaddr = NULL;
500 			bzero(&ia->ia_dstaddr, sizeof(ia->ia_dstaddr));
501 #endif
502 			ia->ia_ifa.ifa_netmask
503 				= (struct sockaddr *)&ia->ia_prefixmask;
504 
505 			ia->ia_ifp = ifp;
506 			if ((oia = in6_ifaddr) != NULL) {
507 				for ( ; oia->ia_next; oia = oia->ia_next)
508 					continue;
509 				oia->ia_next = ia;
510 			} else
511 				in6_ifaddr = ia;
512 			/* gain a refcnt for the link from in6_ifaddr */
513 			ia->ia_ifa.ifa_refcnt++;
514 
515 			TAILQ_INSERT_TAIL(&ifp->if_addrlist, &ia->ia_ifa,
516 			    ifa_list);
517 			/* gain another refcnt for the link from if_addrlist */
518 			ia->ia_ifa.ifa_refcnt++;
519 
520 			newifaddr = 1;
521 		} else
522 			newifaddr = 0;
523 
524 		if (cmd == SIOCAIFADDR_IN6) {
525 			/* sanity for overflow - beware unsigned */
526 			struct in6_addrlifetime *lt;
527 			lt = &ifra->ifra_lifetime;
528 			if (lt->ia6t_vltime != ND6_INFINITE_LIFETIME
529 			 && lt->ia6t_vltime + time_second < time_second) {
530 				return EINVAL;
531 			}
532 			if (lt->ia6t_pltime != ND6_INFINITE_LIFETIME
533 			 && lt->ia6t_pltime + time_second < time_second) {
534 				return EINVAL;
535 			}
536 		}
537 		break;
538 
539 	case SIOCGIFADDR_IN6:
540 		/* This interface is basically deprecated. use SIOCGIFCONF. */
541 		/* fall through */
542 	case SIOCGIFAFLAG_IN6:
543 	case SIOCGIFNETMASK_IN6:
544 	case SIOCGIFDSTADDR_IN6:
545 	case SIOCGIFALIFETIME_IN6:
546 		/* must think again about its semantics */
547 		if (ia == NULL)
548 			return(EADDRNOTAVAIL);
549 		break;
550 	case SIOCSIFALIFETIME_IN6:
551 	    {
552 		struct in6_addrlifetime *lt;
553 
554 		if (!privileged)
555 			return(EPERM);
556 		if (ia == NULL)
557 			return(EADDRNOTAVAIL);
558 		/* sanity for overflow - beware unsigned */
559 		lt = &ifr->ifr_ifru.ifru_lifetime;
560 		if (lt->ia6t_vltime != ND6_INFINITE_LIFETIME
561 		 && lt->ia6t_vltime + time_second < time_second) {
562 			return EINVAL;
563 		}
564 		if (lt->ia6t_pltime != ND6_INFINITE_LIFETIME
565 		 && lt->ia6t_pltime + time_second < time_second) {
566 			return EINVAL;
567 		}
568 		break;
569 	    }
570 	}
571 
572 	switch (cmd) {
573 
574 	case SIOCGIFADDR_IN6:
575 		ifr->ifr_addr = ia->ia_addr;
576 		break;
577 
578 	case SIOCGIFDSTADDR_IN6:
579 		if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
580 			return(EINVAL);
581 		/*
582 		 * XXX: should we check if ifa_dstaddr is NULL and return
583 		 * an error?
584 		 */
585 		ifr->ifr_dstaddr = ia->ia_dstaddr;
586 		break;
587 
588 	case SIOCGIFNETMASK_IN6:
589 		ifr->ifr_addr = ia->ia_prefixmask;
590 		break;
591 
592 	case SIOCGIFAFLAG_IN6:
593 		ifr->ifr_ifru.ifru_flags6 = ia->ia6_flags;
594 		break;
595 
596 	case SIOCGIFSTAT_IN6:
597 		if (ifp == NULL)
598 			return EINVAL;
599 		if (in6_ifstat == NULL || ifp->if_index >= in6_ifstatmax
600 		 || in6_ifstat[ifp->if_index] == NULL) {
601 			/* return EAFNOSUPPORT? */
602 			bzero(&ifr->ifr_ifru.ifru_stat,
603 				sizeof(ifr->ifr_ifru.ifru_stat));
604 		} else
605 			ifr->ifr_ifru.ifru_stat = *in6_ifstat[ifp->if_index];
606 		break;
607 
608 	case SIOCGIFSTAT_ICMP6:
609 		if (ifp == NULL)
610 			return EINVAL;
611 		if (icmp6_ifstat == NULL || ifp->if_index >= icmp6_ifstatmax ||
612 		    icmp6_ifstat[ifp->if_index] == NULL) {
613 			/* return EAFNOSUPPORT? */
614 			bzero(&ifr->ifr_ifru.ifru_stat,
615 				sizeof(ifr->ifr_ifru.ifru_icmp6stat));
616 		} else
617 			ifr->ifr_ifru.ifru_icmp6stat =
618 				*icmp6_ifstat[ifp->if_index];
619 		break;
620 
621 #ifdef COMPAT_IN6IFIOCTL		/* should be unused */
622 	case SIOCSIFDSTADDR_IN6:
623 		if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
624 			return(EINVAL);
625 		oldaddr = ia->ia_dstaddr;
626 		ia->ia_dstaddr = ifr->ifr_dstaddr;
627 
628 		/* link-local index check */
629 		if (IN6_IS_ADDR_LINKLOCAL(&ia->ia_dstaddr.sin6_addr)) {
630 			if (ia->ia_dstaddr.sin6_addr.s6_addr16[1] == 0) {
631 				/* interface ID is not embedded by the user */
632 				ia->ia_dstaddr.sin6_addr.s6_addr16[1]
633 					= htons(ifp->if_index);
634 			} else if (ia->ia_dstaddr.sin6_addr.s6_addr16[1] !=
635 				    htons(ifp->if_index)) {
636 				ia->ia_dstaddr = oldaddr;
637 				return(EINVAL);	/* ifid is contradict */
638 			}
639 		}
640 
641 		if (ifp->if_ioctl && (error = (ifp->if_ioctl)
642 				      (ifp, SIOCSIFDSTADDR, (caddr_t)ia))) {
643 			ia->ia_dstaddr = oldaddr;
644 			return(error);
645 		}
646 		ia->ia_ifa.ifa_dstaddr = (struct sockaddr *)&ia->ia_dstaddr;
647 		if (ia->ia_flags & IFA_ROUTE) {
648 			ia->ia_ifa.ifa_dstaddr = (struct sockaddr *)&oldaddr;
649 			rtinit(&(ia->ia_ifa), (int)RTM_DELETE, RTF_HOST);
650 			ia->ia_ifa.ifa_dstaddr =
651 				(struct sockaddr *)&ia->ia_dstaddr;
652 			rtinit(&(ia->ia_ifa), (int)RTM_ADD, RTF_HOST|RTF_UP);
653 		}
654 		break;
655 
656 #endif
657 	case SIOCGIFALIFETIME_IN6:
658 		ifr->ifr_ifru.ifru_lifetime = ia->ia6_lifetime;
659 		break;
660 
661 	case SIOCSIFALIFETIME_IN6:
662 		ia->ia6_lifetime = ifr->ifr_ifru.ifru_lifetime;
663 		/* for sanity */
664 		if (ia->ia6_lifetime.ia6t_vltime != ND6_INFINITE_LIFETIME) {
665 			ia->ia6_lifetime.ia6t_expire =
666 				time_second + ia->ia6_lifetime.ia6t_vltime;
667 		} else
668 			ia->ia6_lifetime.ia6t_expire = 0;
669 		if (ia->ia6_lifetime.ia6t_pltime != ND6_INFINITE_LIFETIME) {
670 			ia->ia6_lifetime.ia6t_preferred =
671 				time_second + ia->ia6_lifetime.ia6t_pltime;
672 		} else
673 			ia->ia6_lifetime.ia6t_preferred = 0;
674 		break;
675 
676 	case SIOCSIFADDR_IN6:
677 		error = in6_ifinit(ifp, ia, &ifr->ifr_addr, 1);
678 #if 0
679 		/*
680 		 * the code chokes if we are to assign multiple addresses with
681 		 * the same address prefix (rtinit() will return EEXIST, which
682 		 * is not fatal actually).  we will get memory leak if we
683 		 * don't do it.
684 		 * -> we may want to hide EEXIST from rtinit().
685 		 */
686   undo:
687 		if (error && newifaddr) {
688 			TAILQ_REMOVE(&ifp->if_addrlist, &ia->ia_ifa, ifa_list);
689 			/* release a refcnt for the link from if_addrlist */
690 			IFAFREE(&ia->ia_ifa);
691 
692 			oia = ia;
693 			if (oia == (ia = in6_ifaddr))
694 				in6_ifaddr = ia->ia_next;
695 			else {
696 				while (ia->ia_next && (ia->ia_next != oia))
697 					ia = ia->ia_next;
698 				if (ia->ia_next)
699 					ia->ia_next = oia->ia_next;
700 				else {
701 					printf("Didn't unlink in6_ifaddr "
702 					    "from list\n");
703 				}
704 			}
705 			/* release another refcnt for the link from in6_ifaddr */
706 			IFAFREE(&oia->ia_ifa);
707 		}
708 #endif
709 		return error;
710 
711 #ifdef COMPAT_IN6IFIOCTL		/* XXX should be unused */
712 	case SIOCSIFNETMASK_IN6:
713 		ia->ia_prefixmask = ifr->ifr_addr;
714 		bzero(&net, sizeof(net));
715 		net.sin6_len = sizeof(struct sockaddr_in6);
716 		net.sin6_family = AF_INET6;
717 		net.sin6_port = htons(0);
718 		net.sin6_flowinfo = htonl(0);
719 		net.sin6_addr.s6_addr32[0]
720 			= ia->ia_addr.sin6_addr.s6_addr32[0] &
721 				ia->ia_prefixmask.sin6_addr.s6_addr32[0];
722 		net.sin6_addr.s6_addr32[1]
723 			= ia->ia_addr.sin6_addr.s6_addr32[1] &
724 				ia->ia_prefixmask.sin6_addr.s6_addr32[1];
725 		net.sin6_addr.s6_addr32[2]
726 			= ia->ia_addr.sin6_addr.s6_addr32[2] &
727 				ia->ia_prefixmask.sin6_addr.s6_addr32[2];
728 		net.sin6_addr.s6_addr32[3]
729 			= ia->ia_addr.sin6_addr.s6_addr32[3] &
730 				ia->ia_prefixmask.sin6_addr.s6_addr32[3];
731 		ia->ia_net = net;
732 		break;
733 #endif
734 
735 	case SIOCAIFADDR_IN6:
736 		prefixIsNew = 0;
737 		hostIsNew = 1;
738 
739 		if (ifra->ifra_addr.sin6_len == 0) {
740 			ifra->ifra_addr = ia->ia_addr;
741 			hostIsNew = 0;
742 		} else if (IN6_ARE_ADDR_EQUAL(&ifra->ifra_addr.sin6_addr,
743 					      &ia->ia_addr.sin6_addr))
744 			hostIsNew = 0;
745 
746 		/* Validate address families: */
747 		/*
748 		 * The destination address for a p2p link must have a family
749 		 * of AF_UNSPEC or AF_INET6.
750 		 */
751 		if ((ifp->if_flags & IFF_POINTOPOINT) != 0 &&
752 		    ifra->ifra_dstaddr.sin6_family != AF_INET6 &&
753 		    ifra->ifra_dstaddr.sin6_family != AF_UNSPEC)
754 			return(EAFNOSUPPORT);
755 		/*
756 		 * The prefixmask must have a family of AF_UNSPEC or AF_INET6.
757 		 */
758 		if (ifra->ifra_prefixmask.sin6_family != AF_INET6 &&
759 		    ifra->ifra_prefixmask.sin6_family != AF_UNSPEC)
760 			return(EAFNOSUPPORT);
761 
762 		if (ifra->ifra_prefixmask.sin6_len) {
763 			in6_ifscrub(ifp, ia);
764 			ia->ia_prefixmask = ifra->ifra_prefixmask;
765 			prefixIsNew = 1;
766 		}
767 		if ((ifp->if_flags & IFF_POINTOPOINT) &&
768 		    (ifra->ifra_dstaddr.sin6_family == AF_INET6)) {
769 			in6_ifscrub(ifp, ia);
770 			oldaddr = ia->ia_dstaddr;
771 			ia->ia_dstaddr = ifra->ifra_dstaddr;
772 			/* link-local index check: should be a separate function? */
773 			if (IN6_IS_ADDR_LINKLOCAL(&ia->ia_dstaddr.sin6_addr)) {
774 				if (ia->ia_dstaddr.sin6_addr.s6_addr16[1] == 0) {
775 					/*
776 					 * interface ID is not embedded by
777 					 * the user
778 					 */
779 					ia->ia_dstaddr.sin6_addr.s6_addr16[1]
780 						= htons(ifp->if_index);
781 				} else if (ia->ia_dstaddr.sin6_addr.s6_addr16[1] !=
782 					    htons(ifp->if_index)) {
783 					ia->ia_dstaddr = oldaddr;
784 					return(EINVAL);	/* ifid is contradict */
785 				}
786 			}
787 			prefixIsNew = 1; /* We lie; but effect's the same */
788 		}
789 		if (hostIsNew || prefixIsNew) {
790 			error = in6_ifinit(ifp, ia, &ifra->ifra_addr, 0);
791 #if 0
792 			if (error)
793 				goto undo;
794 #endif
795 		}
796 		if (hostIsNew && (ifp->if_flags & IFF_MULTICAST)) {
797 			int error_local = 0;
798 
799 			/*
800 			 * join solicited multicast addr for new host id
801 			 */
802 			struct in6_addr llsol;
803 			bzero(&llsol, sizeof(struct in6_addr));
804 			llsol.s6_addr16[0] = htons(0xff02);
805 			llsol.s6_addr16[1] = htons(ifp->if_index);
806 			llsol.s6_addr32[1] = 0;
807 			llsol.s6_addr32[2] = htonl(1);
808 			llsol.s6_addr32[3] =
809 				ifra->ifra_addr.sin6_addr.s6_addr32[3];
810 			llsol.s6_addr8[12] = 0xff;
811 			(void)in6_addmulti(&llsol, ifp, &error_local);
812 			if (error == 0)
813 				error = error_local;
814 		}
815 
816 		ia->ia6_flags = ifra->ifra_flags;
817 		ia->ia6_flags &= ~IN6_IFF_DUPLICATED;	/*safety*/
818 
819 		ia->ia6_lifetime = ifra->ifra_lifetime;
820 		/* for sanity */
821 		if (ia->ia6_lifetime.ia6t_vltime != ND6_INFINITE_LIFETIME) {
822 			ia->ia6_lifetime.ia6t_expire =
823 				time_second + ia->ia6_lifetime.ia6t_vltime;
824 		} else
825 			ia->ia6_lifetime.ia6t_expire = 0;
826 		if (ia->ia6_lifetime.ia6t_pltime != ND6_INFINITE_LIFETIME) {
827 			ia->ia6_lifetime.ia6t_preferred =
828 				time_second + ia->ia6_lifetime.ia6t_pltime;
829 		} else
830 			ia->ia6_lifetime.ia6t_preferred = 0;
831 
832 		/*
833 		 * Perform DAD, if needed.
834 		 * XXX It may be of use, if we can administratively
835 		 * disable DAD.
836 		 */
837 		switch (ifp->if_type) {
838 		case IFT_ARCNET:
839 		case IFT_ETHER:
840 		case IFT_FDDI:
841 #if 0
842 		case IFT_ATM:
843 		case IFT_SLIP:
844 		case IFT_PPP:
845 #endif
846 			{
847 				ia->ia6_flags |= IN6_IFF_TENTATIVE;
848 				nd6_dad_start((struct ifaddr *)ia, NULL);
849 			}
850 			break;
851 #ifdef IFT_DUMMY
852 		case IFT_DUMMY:
853 #endif
854 		case IFT_FAITH:
855 		case IFT_GIF:
856 		case IFT_LOOP:
857 		default:
858 			break;
859 		}
860 
861 		if (hostIsNew) {
862 			int iilen;
863 			int error_local = 0;
864 
865 			iilen = (sizeof(ia->ia_prefixmask.sin6_addr) << 3) -
866 				in6_mask2len(&ia->ia_prefixmask.sin6_addr);
867 			error_local = in6_prefix_add_ifid(iilen, ia);
868 			if (error == 0)
869 				error = error_local;
870 		}
871 
872 		return(error);
873 
874 	case SIOCDIFADDR_IN6:
875 		in6_purgeaddr(&ia->ia_ifa, ifp);
876 		break;
877 
878 	default:
879 		if (ifp == NULL || ifp->if_ioctl == 0)
880 			return(EOPNOTSUPP);
881 		return((*ifp->if_ioctl)(ifp, cmd, data));
882 	}
883 	return(0);
884 }
885 
886 void
887 in6_purgeaddr(ifa, ifp)
888 	struct ifaddr *ifa;
889 	struct ifnet *ifp;
890 {
891 	struct in6_ifaddr *oia, *ia = (void *) ifa;
892 	int plen;
893 
894 	in6_ifscrub(ifp, ia);
895 
896 	if (ifp->if_flags & IFF_MULTICAST) {
897 		/*
898 		 * delete solicited multicast addr for deleting host id
899 		 */
900 		struct in6_multi *in6m;
901 		struct in6_addr llsol;
902 		bzero(&llsol, sizeof(struct in6_addr));
903 		llsol.s6_addr16[0] = htons(0xff02);
904 		llsol.s6_addr16[1] = htons(ifp->if_index);
905 		llsol.s6_addr32[1] = 0;
906 		llsol.s6_addr32[2] = htonl(1);
907 		llsol.s6_addr32[3] =
908 			ia->ia_addr.sin6_addr.s6_addr32[3];
909 		llsol.s6_addr8[12] = 0xff;
910 
911 		IN6_LOOKUP_MULTI(llsol, ifp, in6m);
912 		if (in6m)
913 			in6_delmulti(in6m);
914 	}
915 
916 	TAILQ_REMOVE(&ifp->if_addrlist, &ia->ia_ifa, ifa_list);
917 	/* release a refcnt for the link from if_addrlist */
918 	IFAFREE(&ia->ia_ifa);
919 
920 	oia = ia;
921 	if (oia == (ia = in6_ifaddr))
922 		in6_ifaddr = ia->ia_next;
923 	else {
924 		while (ia->ia_next && (ia->ia_next != oia))
925 			ia = ia->ia_next;
926 		if (ia->ia_next)
927 			ia->ia_next = oia->ia_next;
928 		else
929 			printf("Didn't unlink in6_ifaddr from list\n");
930 	}
931 	{
932 		int iilen;
933 
934 		plen = in6_mask2len(&oia->ia_prefixmask.sin6_addr);
935 		iilen = (sizeof(oia->ia_prefixmask.sin6_addr) << 3) - plen;
936 		in6_prefix_remove_ifid(iilen, oia);
937 	}
938 
939 	/*
940 	 * Check if we have another address that has the same prefix of
941 	 * the purged address. If we have one, reinstall the corresponding
942 	 * interface route.
943 	 */
944 	for (ia = in6_ifaddr; ia; ia = ia->ia_next) {
945 		int e;
946 
947 		if (in6_are_prefix_equal(&ia->ia_addr.sin6_addr,
948 					 &oia->ia_addr.sin6_addr, plen)) {
949 			if ((e = rtinit(&(ia->ia_ifa), (int)RTM_ADD,
950 					ia->ia_flags)) == 0) {
951 				ia->ia_flags |= IFA_ROUTE;
952 				break;
953 			}
954 			else {
955 				log(LOG_NOTICE,
956 				    "in6_purgeaddr: failed to add an interface"
957 				    " route for %s/%d on %s, errno = %d\n",
958 				    ip6_sprintf(&ia->ia_addr.sin6_addr),
959 				    plen, if_name(ia->ia_ifp), e);
960 				/* still trying */
961 			}
962 		}
963 	}
964 
965 	/* release another refcnt for the link from in6_ifaddr */
966 	IFAFREE(&oia->ia_ifa);
967 }
968 
969 /*
970  * SIOC[GAD]LIFADDR.
971  *	SIOCGLIFADDR: get first address. (?)
972  *	SIOCGLIFADDR with IFLR_PREFIX:
973  *		get first address that matches the specified prefix.
974  *	SIOCALIFADDR: add the specified address.
975  *	SIOCALIFADDR with IFLR_PREFIX:
976  *		add the specified prefix, filling hostid part from
977  *		the first link-local address.  prefixlen must be <= 64.
978  *	SIOCDLIFADDR: delete the specified address.
979  *	SIOCDLIFADDR with IFLR_PREFIX:
980  *		delete the first address that matches the specified prefix.
981  * return values:
982  *	EINVAL on invalid parameters
983  *	EADDRNOTAVAIL on prefix match failed/specified address not found
984  *	other values may be returned from in6_ioctl()
985  *
986  * NOTE: SIOCALIFADDR(with IFLR_PREFIX set) allows prefixlen less than 64.
987  * this is to accomodate address naming scheme other than RFC2374,
988  * in the future.
989  * RFC2373 defines interface id to be 64bit, but it allows non-RFC2374
990  * address encoding scheme. (see figure on page 8)
991  */
992 static int
993 in6_lifaddr_ioctl(so, cmd, data, ifp, p)
994 	struct socket *so;
995 	u_long cmd;
996 	caddr_t	data;
997 	struct ifnet *ifp;
998 	struct proc *p;
999 {
1000 	struct if_laddrreq *iflr = (struct if_laddrreq *)data;
1001 	struct ifaddr *ifa;
1002 	struct sockaddr *sa;
1003 
1004 	/* sanity checks */
1005 	if (!data || !ifp) {
1006 		panic("invalid argument to in6_lifaddr_ioctl");
1007 		/*NOTRECHED*/
1008 	}
1009 
1010 	switch (cmd) {
1011 	case SIOCGLIFADDR:
1012 		/* address must be specified on GET with IFLR_PREFIX */
1013 		if ((iflr->flags & IFLR_PREFIX) == 0)
1014 			break;
1015 		/*FALLTHROUGH*/
1016 	case SIOCALIFADDR:
1017 	case SIOCDLIFADDR:
1018 		/* address must be specified on ADD and DELETE */
1019 		sa = (struct sockaddr *)&iflr->addr;
1020 		if (sa->sa_family != AF_INET6)
1021 			return EINVAL;
1022 		if (sa->sa_len != sizeof(struct sockaddr_in6))
1023 			return EINVAL;
1024 		/* XXX need improvement */
1025 		sa = (struct sockaddr *)&iflr->dstaddr;
1026 		if (sa->sa_family && sa->sa_family != AF_INET6)
1027 			return EINVAL;
1028 		if (sa->sa_len && sa->sa_len != sizeof(struct sockaddr_in6))
1029 			return EINVAL;
1030 		break;
1031 	default: /*shouldn't happen*/
1032 #if 0
1033 		panic("invalid cmd to in6_lifaddr_ioctl");
1034 		/*NOTREACHED*/
1035 #else
1036 		return EOPNOTSUPP;
1037 #endif
1038 	}
1039 	if (sizeof(struct in6_addr) * 8 < iflr->prefixlen)
1040 		return EINVAL;
1041 
1042 	switch (cmd) {
1043 	case SIOCALIFADDR:
1044 	    {
1045 		struct in6_aliasreq ifra;
1046 		struct in6_addr *hostid = NULL;
1047 		int prefixlen;
1048 
1049 		if ((iflr->flags & IFLR_PREFIX) != 0) {
1050 			struct sockaddr_in6 *sin6;
1051 
1052 			/*
1053 			 * hostid is to fill in the hostid part of the
1054 			 * address.  hostid points to the first link-local
1055 			 * address attached to the interface.
1056 			 */
1057 			ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp, 0);
1058 			if (!ifa)
1059 				return EADDRNOTAVAIL;
1060 			hostid = IFA_IN6(ifa);
1061 
1062 		 	/* prefixlen must be <= 64. */
1063 			if (64 < iflr->prefixlen)
1064 				return EINVAL;
1065 			prefixlen = iflr->prefixlen;
1066 
1067 			/* hostid part must be zero. */
1068 			sin6 = (struct sockaddr_in6 *)&iflr->addr;
1069 			if (sin6->sin6_addr.s6_addr32[2] != 0
1070 			 || sin6->sin6_addr.s6_addr32[3] != 0) {
1071 				return EINVAL;
1072 			}
1073 		} else
1074 			prefixlen = iflr->prefixlen;
1075 
1076 		/* copy args to in6_aliasreq, perform ioctl(SIOCAIFADDR_IN6). */
1077 		bzero(&ifra, sizeof(ifra));
1078 		bcopy(iflr->iflr_name, ifra.ifra_name,
1079 			sizeof(ifra.ifra_name));
1080 
1081 		bcopy(&iflr->addr, &ifra.ifra_addr,
1082 			((struct sockaddr *)&iflr->addr)->sa_len);
1083 		if (hostid) {
1084 			/* fill in hostid part */
1085 			ifra.ifra_addr.sin6_addr.s6_addr32[2] =
1086 				hostid->s6_addr32[2];
1087 			ifra.ifra_addr.sin6_addr.s6_addr32[3] =
1088 				hostid->s6_addr32[3];
1089 		}
1090 
1091 		if (((struct sockaddr *)&iflr->dstaddr)->sa_family) {	/*XXX*/
1092 			bcopy(&iflr->dstaddr, &ifra.ifra_dstaddr,
1093 				((struct sockaddr *)&iflr->dstaddr)->sa_len);
1094 			if (hostid) {
1095 				ifra.ifra_dstaddr.sin6_addr.s6_addr32[2] =
1096 					hostid->s6_addr32[2];
1097 				ifra.ifra_dstaddr.sin6_addr.s6_addr32[3] =
1098 					hostid->s6_addr32[3];
1099 			}
1100 		}
1101 
1102 		ifra.ifra_prefixmask.sin6_family = AF_INET6;
1103 		ifra.ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6);
1104 		in6_len2mask(&ifra.ifra_prefixmask.sin6_addr, prefixlen);
1105 
1106 		ifra.ifra_flags = iflr->flags & ~IFLR_PREFIX;
1107 		return in6_control(so, SIOCAIFADDR_IN6, (caddr_t)&ifra, ifp, p);
1108 	    }
1109 	case SIOCGLIFADDR:
1110 	case SIOCDLIFADDR:
1111 	    {
1112 		struct in6_ifaddr *ia;
1113 		struct in6_addr mask, candidate, match;
1114 		struct sockaddr_in6 *sin6;
1115 		int cmp;
1116 
1117 		bzero(&mask, sizeof(mask));
1118 		if (iflr->flags & IFLR_PREFIX) {
1119 			/* lookup a prefix rather than address. */
1120 			in6_len2mask(&mask, iflr->prefixlen);
1121 
1122 			sin6 = (struct sockaddr_in6 *)&iflr->addr;
1123 			bcopy(&sin6->sin6_addr, &match, sizeof(match));
1124 			match.s6_addr32[0] &= mask.s6_addr32[0];
1125 			match.s6_addr32[1] &= mask.s6_addr32[1];
1126 			match.s6_addr32[2] &= mask.s6_addr32[2];
1127 			match.s6_addr32[3] &= mask.s6_addr32[3];
1128 
1129 			/* if you set extra bits, that's wrong */
1130 			if (bcmp(&match, &sin6->sin6_addr, sizeof(match)))
1131 				return EINVAL;
1132 
1133 			cmp = 1;
1134 		} else {
1135 			if (cmd == SIOCGLIFADDR) {
1136 				/* on getting an address, take the 1st match */
1137 				cmp = 0;	/*XXX*/
1138 			} else {
1139 				/* on deleting an address, do exact match */
1140 				in6_len2mask(&mask, 128);
1141 				sin6 = (struct sockaddr_in6 *)&iflr->addr;
1142 				bcopy(&sin6->sin6_addr, &match, sizeof(match));
1143 
1144 				cmp = 1;
1145 			}
1146 		}
1147 
1148 		TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list)
1149 		{
1150 			if (ifa->ifa_addr->sa_family != AF_INET6)
1151 				continue;
1152 			if (!cmp)
1153 				break;
1154 			bcopy(IFA_IN6(ifa), &candidate, sizeof(candidate));
1155 			candidate.s6_addr32[0] &= mask.s6_addr32[0];
1156 			candidate.s6_addr32[1] &= mask.s6_addr32[1];
1157 			candidate.s6_addr32[2] &= mask.s6_addr32[2];
1158 			candidate.s6_addr32[3] &= mask.s6_addr32[3];
1159 			if (IN6_ARE_ADDR_EQUAL(&candidate, &match))
1160 				break;
1161 		}
1162 		if (!ifa)
1163 			return EADDRNOTAVAIL;
1164 		ia = ifa2ia6(ifa);
1165 
1166 		if (cmd == SIOCGLIFADDR) {
1167 			/* fill in the if_laddrreq structure */
1168 			bcopy(&ia->ia_addr, &iflr->addr, ia->ia_addr.sin6_len);
1169 
1170 			if ((ifp->if_flags & IFF_POINTOPOINT) != 0) {
1171 				bcopy(&ia->ia_dstaddr, &iflr->dstaddr,
1172 					ia->ia_dstaddr.sin6_len);
1173 			} else
1174 				bzero(&iflr->dstaddr, sizeof(iflr->dstaddr));
1175 
1176 			iflr->prefixlen =
1177 				in6_mask2len(&ia->ia_prefixmask.sin6_addr);
1178 
1179 			iflr->flags = ia->ia6_flags;	/*XXX*/
1180 
1181 			return 0;
1182 		} else {
1183 			struct in6_aliasreq ifra;
1184 
1185 			/* fill in6_aliasreq and do ioctl(SIOCDIFADDR_IN6) */
1186 			bzero(&ifra, sizeof(ifra));
1187 			bcopy(iflr->iflr_name, ifra.ifra_name,
1188 				sizeof(ifra.ifra_name));
1189 
1190 			bcopy(&ia->ia_addr, &ifra.ifra_addr,
1191 				ia->ia_addr.sin6_len);
1192 			if ((ifp->if_flags & IFF_POINTOPOINT) != 0) {
1193 				bcopy(&ia->ia_dstaddr, &ifra.ifra_dstaddr,
1194 					ia->ia_dstaddr.sin6_len);
1195 			} else {
1196 				bzero(&ifra.ifra_dstaddr,
1197 				    sizeof(ifra.ifra_dstaddr));
1198 			}
1199 			bcopy(&ia->ia_prefixmask, &ifra.ifra_dstaddr,
1200 				ia->ia_prefixmask.sin6_len);
1201 
1202 			ifra.ifra_flags = ia->ia6_flags;
1203 			return in6_control(so, SIOCDIFADDR_IN6, (caddr_t)&ifra,
1204 				ifp, p);
1205 		}
1206 	    }
1207 	}
1208 
1209 	return EOPNOTSUPP;	/*just for safety*/
1210 }
1211 
1212 /*
1213  * Delete any existing route for an interface.
1214  */
1215 void
1216 in6_ifscrub(ifp, ia)
1217 	register struct ifnet *ifp;
1218 	register struct in6_ifaddr *ia;
1219 {
1220 	if ((ia->ia_flags & IFA_ROUTE) == 0)
1221 		return;
1222 	if (ifp->if_flags & (IFF_LOOPBACK | IFF_POINTOPOINT))
1223 		rtinit(&(ia->ia_ifa), (int)RTM_DELETE, RTF_HOST);
1224 	else
1225 		rtinit(&(ia->ia_ifa), (int)RTM_DELETE, 0);
1226 	ia->ia_flags &= ~IFA_ROUTE;
1227 
1228 	/* Remove ownaddr's loopback rtentry, if it exists. */
1229 	in6_ifremloop(&(ia->ia_ifa));
1230 }
1231 
1232 /*
1233  * Initialize an interface's intetnet6 address
1234  * and routing table entry.
1235  */
1236 int
1237 in6_ifinit(ifp, ia, sin6, scrub)
1238 	struct ifnet *ifp;
1239 	struct in6_ifaddr *ia;
1240 	struct sockaddr_in6 *sin6;
1241 	int scrub;
1242 {
1243 	struct	sockaddr_in6 oldaddr;
1244 	int	error, flags = RTF_UP;
1245 	int	s = splimp();
1246 
1247 	oldaddr = ia->ia_addr;
1248 	ia->ia_addr = *sin6;
1249 	/*
1250 	 * Give the interface a chance to initialize
1251 	 * if this is its first address,
1252 	 * and to validate the address if necessary.
1253 	 */
1254 	if (ifp->if_ioctl &&
1255 	   (error = (*ifp->if_ioctl)(ifp, SIOCSIFADDR, (caddr_t)ia))) {
1256 		splx(s);
1257 		ia->ia_addr = oldaddr;
1258 		return(error);
1259 	}
1260 
1261 	switch (ifp->if_type) {
1262 	case IFT_ARCNET:
1263 	case IFT_ETHER:
1264 	case IFT_FDDI:
1265 		ia->ia_ifa.ifa_rtrequest = nd6_rtrequest;
1266 		ia->ia_ifa.ifa_flags |= RTF_CLONING;
1267 		break;
1268 	case IFT_PPP:
1269 		ia->ia_ifa.ifa_rtrequest = nd6_p2p_rtrequest;
1270 		ia->ia_ifa.ifa_flags |= RTF_CLONING;
1271 		break;
1272 	}
1273 
1274 	splx(s);
1275 	if (scrub) {
1276 		ia->ia_ifa.ifa_addr = (struct sockaddr *)&oldaddr;
1277 		in6_ifscrub(ifp, ia);
1278 		ia->ia_ifa.ifa_addr = (struct sockaddr *)&ia->ia_addr;
1279 	}
1280 	/* xxx
1281 	 * in_socktrim
1282 	 */
1283 	/*
1284 	 * Add route for the network.
1285 	 */
1286 	ia->ia_ifa.ifa_metric = ifp->if_metric;
1287 	if (ifp->if_flags & IFF_LOOPBACK) {
1288 		ia->ia_ifa.ifa_dstaddr = ia->ia_ifa.ifa_addr;
1289 		flags |= RTF_HOST;
1290 	} else if (ifp->if_flags & IFF_POINTOPOINT) {
1291 		if (ia->ia_dstaddr.sin6_family != AF_INET6)
1292 			return(0);
1293 		flags |= RTF_HOST;
1294 	}
1295 	if ((error = rtinit(&(ia->ia_ifa), (int)RTM_ADD, flags)) == 0)
1296 		ia->ia_flags |= IFA_ROUTE;
1297 	/* XXX check if the subnet route points to the same interface */
1298 	if (error == EEXIST)
1299 		error = 0;
1300 
1301 	/* Add ownaddr as loopback rtentry, if necessary(ex. on p2p link). */
1302 	in6_ifaddloop(&(ia->ia_ifa));
1303 
1304 	return(error);
1305 }
1306 
1307 /*
1308  * Add an address to the list of IP6 multicast addresses for a
1309  * given interface.
1310  */
1311 struct	in6_multi *
1312 in6_addmulti(maddr6, ifp, errorp)
1313 	register struct in6_addr *maddr6;
1314 	register struct ifnet *ifp;
1315 	int *errorp;
1316 {
1317 	struct	in6_multi *in6m;
1318 	struct sockaddr_in6 sin6;
1319 	struct ifmultiaddr *ifma;
1320 	int	s = splnet();
1321 
1322 	*errorp = 0;
1323 
1324 	/*
1325 	 * Call generic routine to add membership or increment
1326 	 * refcount.  It wants addresses in the form of a sockaddr,
1327 	 * so we build one here (being careful to zero the unused bytes).
1328 	 */
1329 	bzero(&sin6, sizeof sin6);
1330 	sin6.sin6_family = AF_INET6;
1331 	sin6.sin6_len = sizeof sin6;
1332 	sin6.sin6_addr = *maddr6;
1333 	*errorp = if_addmulti(ifp, (struct sockaddr *)&sin6, &ifma);
1334 	if (*errorp) {
1335 		splx(s);
1336 		return 0;
1337 	}
1338 
1339 	/*
1340 	 * If ifma->ifma_protospec is null, then if_addmulti() created
1341 	 * a new record.  Otherwise, we are done.
1342 	 */
1343 	if (ifma->ifma_protospec != 0)
1344 		return ifma->ifma_protospec;
1345 
1346 	/* XXX - if_addmulti uses M_WAITOK.  Can this really be called
1347 	   at interrupt time?  If so, need to fix if_addmulti. XXX */
1348 	in6m = (struct in6_multi *)malloc(sizeof(*in6m), M_IPMADDR, M_NOWAIT);
1349 	if (in6m == NULL) {
1350 		splx(s);
1351 		return (NULL);
1352 	}
1353 
1354 	bzero(in6m, sizeof *in6m);
1355 	in6m->in6m_addr = *maddr6;
1356 	in6m->in6m_ifp = ifp;
1357 	in6m->in6m_ifma = ifma;
1358 	ifma->ifma_protospec = in6m;
1359 	LIST_INSERT_HEAD(&in6_multihead, in6m, in6m_entry);
1360 
1361 	/*
1362 	 * Let MLD6 know that we have joined a new IP6 multicast
1363 	 * group.
1364 	 */
1365 	mld6_start_listening(in6m);
1366 	splx(s);
1367 	return(in6m);
1368 }
1369 
1370 /*
1371  * Delete a multicast address record.
1372  */
1373 void
1374 in6_delmulti(in6m)
1375 	struct in6_multi *in6m;
1376 {
1377 	struct ifmultiaddr *ifma = in6m->in6m_ifma;
1378 	int	s = splnet();
1379 
1380 	if (ifma->ifma_refcount == 1) {
1381 		/*
1382 		 * No remaining claims to this record; let MLD6 know
1383 		 * that we are leaving the multicast group.
1384 		 */
1385 		mld6_stop_listening(in6m);
1386 		ifma->ifma_protospec = 0;
1387 		LIST_REMOVE(in6m, in6m_entry);
1388 		free(in6m, M_IPMADDR);
1389 	}
1390 	/* XXX - should be separate API for when we have an ifma? */
1391 	if_delmulti(ifma->ifma_ifp, ifma->ifma_addr);
1392 	splx(s);
1393 }
1394 
1395 /*
1396  * Find an IPv6 interface link-local address specific to an interface.
1397  */
1398 struct in6_ifaddr *
1399 in6ifa_ifpforlinklocal(ifp, ignoreflags)
1400 	struct ifnet *ifp;
1401 	int ignoreflags;
1402 {
1403 	register struct ifaddr *ifa;
1404 
1405 	TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list)
1406 	{
1407 		if (ifa->ifa_addr == NULL)
1408 			continue;	/* just for safety */
1409 		if (ifa->ifa_addr->sa_family != AF_INET6)
1410 			continue;
1411 		if (IN6_IS_ADDR_LINKLOCAL(IFA_IN6(ifa))) {
1412 			if ((((struct in6_ifaddr *)ifa)->ia6_flags &
1413 			     ignoreflags) != 0)
1414 				continue;
1415 			break;
1416 		}
1417 	}
1418 
1419 	return((struct in6_ifaddr *)ifa);
1420 }
1421 
1422 
1423 /*
1424  * find the internet address corresponding to a given interface and address.
1425  */
1426 struct in6_ifaddr *
1427 in6ifa_ifpwithaddr(ifp, addr)
1428 	struct ifnet *ifp;
1429 	struct in6_addr *addr;
1430 {
1431 	register struct ifaddr *ifa;
1432 
1433 	TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list)
1434 	{
1435 		if (ifa->ifa_addr == NULL)
1436 			continue;	/* just for safety */
1437 		if (ifa->ifa_addr->sa_family != AF_INET6)
1438 			continue;
1439 		if (IN6_ARE_ADDR_EQUAL(addr, IFA_IN6(ifa)))
1440 			break;
1441 	}
1442 
1443 	return((struct in6_ifaddr *)ifa);
1444 }
1445 
1446 /*
1447  * Convert IP6 address to printable (loggable) representation.
1448  */
1449 static char digits[] = "0123456789abcdef";
1450 static int ip6round = 0;
1451 char *
1452 ip6_sprintf(addr)
1453 register struct in6_addr *addr;
1454 {
1455 	static char ip6buf[8][48];
1456 	register int i;
1457 	register char *cp;
1458 	register u_short *a = (u_short *)addr;
1459 	register u_char *d;
1460 	int dcolon = 0;
1461 
1462 	ip6round = (ip6round + 1) & 7;
1463 	cp = ip6buf[ip6round];
1464 
1465 	for (i = 0; i < 8; i++) {
1466 		if (dcolon == 1) {
1467 			if (*a == 0) {
1468 				if (i == 7)
1469 					*cp++ = ':';
1470 				a++;
1471 				continue;
1472 			} else
1473 				dcolon = 2;
1474 		}
1475 		if (*a == 0) {
1476 			if (dcolon == 0 && *(a + 1) == 0) {
1477 				if (i == 0)
1478 					*cp++ = ':';
1479 				*cp++ = ':';
1480 				dcolon = 1;
1481 			} else {
1482 				*cp++ = '0';
1483 				*cp++ = ':';
1484 			}
1485 			a++;
1486 			continue;
1487 		}
1488 		d = (u_char *)a;
1489 		*cp++ = digits[*d >> 4];
1490 		*cp++ = digits[*d++ & 0xf];
1491 		*cp++ = digits[*d >> 4];
1492 		*cp++ = digits[*d & 0xf];
1493 		*cp++ = ':';
1494 		a++;
1495 	}
1496 	*--cp = 0;
1497 	return(ip6buf[ip6round]);
1498 }
1499 
1500 int
1501 in6_localaddr(in6)
1502 	struct in6_addr *in6;
1503 {
1504 	struct in6_ifaddr *ia;
1505 
1506 	if (IN6_IS_ADDR_LOOPBACK(in6) || IN6_IS_ADDR_LINKLOCAL(in6))
1507 		return 1;
1508 
1509 	for (ia = in6_ifaddr; ia; ia = ia->ia_next)
1510 		if (IN6_ARE_MASKED_ADDR_EQUAL(in6, &ia->ia_addr.sin6_addr,
1511 					      &ia->ia_prefixmask.sin6_addr))
1512 			return 1;
1513 
1514 	return (0);
1515 }
1516 
1517 /*
1518  * return length of part which dst and src are equal
1519  * hard coding...
1520  */
1521 int
1522 in6_matchlen(src, dst)
1523 struct in6_addr *src, *dst;
1524 {
1525 	int match = 0;
1526 	u_char *s = (u_char *)src, *d = (u_char *)dst;
1527 	u_char *lim = s + 16, r;
1528 
1529 	while (s < lim)
1530 		if ((r = (*d++ ^ *s++)) != 0) {
1531 			while (r < 128) {
1532 				match++;
1533 				r <<= 1;
1534 			}
1535 			break;
1536 		} else
1537 			match += 8;
1538 	return match;
1539 }
1540 
1541 /* XXX: to be scope conscious */
1542 int
1543 in6_are_prefix_equal(p1, p2, len)
1544 	struct in6_addr *p1, *p2;
1545 	int len;
1546 {
1547 	int bytelen, bitlen;
1548 
1549 	/* sanity check */
1550 	if (0 > len || len > 128) {
1551 		log(LOG_ERR, "in6_are_prefix_equal: invalid prefix length(%d)\n",
1552 		    len);
1553 		return(0);
1554 	}
1555 
1556 	bytelen = len / 8;
1557 	bitlen = len % 8;
1558 
1559 	if (bcmp(&p1->s6_addr, &p2->s6_addr, bytelen))
1560 		return(0);
1561 	if (p1->s6_addr[bytelen] >> (8 - bitlen) !=
1562 	    p2->s6_addr[bytelen] >> (8 - bitlen))
1563 		return(0);
1564 
1565 	return(1);
1566 }
1567 
1568 void
1569 in6_prefixlen2mask(maskp, len)
1570 	struct in6_addr *maskp;
1571 	int len;
1572 {
1573 	u_char maskarray[8] = {0x80, 0xc0, 0xe0, 0xf0, 0xf8, 0xfc, 0xfe, 0xff};
1574 	int bytelen, bitlen, i;
1575 
1576 	/* sanity check */
1577 	if (0 > len || len > 128) {
1578 		log(LOG_ERR, "in6_prefixlen2mask: invalid prefix length(%d)\n",
1579 		    len);
1580 		return;
1581 	}
1582 
1583 	bzero(maskp, sizeof(*maskp));
1584 	bytelen = len / 8;
1585 	bitlen = len % 8;
1586 	for (i = 0; i < bytelen; i++)
1587 		maskp->s6_addr[i] = 0xff;
1588 	if (bitlen)
1589 		maskp->s6_addr[bytelen] = maskarray[bitlen - 1];
1590 }
1591 
1592 /*
1593  * return the best address out of the same scope
1594  */
1595 struct in6_ifaddr *
1596 in6_ifawithscope(oifp, dst)
1597 	register struct ifnet *oifp;
1598 	register struct in6_addr *dst;
1599 {
1600 	int dst_scope =	in6_addrscope(dst), src_scope, best_scope = 0;
1601 	int blen = -1;
1602 	struct ifaddr *ifa;
1603 	struct ifnet *ifp;
1604 	struct in6_ifaddr *ifa_best = NULL;
1605 
1606 	if (oifp == NULL) {
1607 		printf("in6_ifawithscope: output interface is not specified\n");
1608 		return(NULL);
1609 	}
1610 
1611 	/*
1612 	 * We search for all addresses on all interfaces from the beginning.
1613 	 * Comparing an interface with the outgoing interface will be done
1614 	 * only at the final stage of tiebreaking.
1615 	 */
1616 	for (ifp = TAILQ_FIRST(&ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list))
1617 	{
1618 		/*
1619 		 * We can never take an address that breaks the scope zone
1620 		 * of the destination.
1621 		 */
1622 		if (in6_addr2scopeid(ifp, dst) != in6_addr2scopeid(oifp, dst))
1623 			continue;
1624 
1625 		TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list)
1626 		{
1627 			int tlen = -1, dscopecmp, bscopecmp, matchcmp;
1628 
1629 			if (ifa->ifa_addr->sa_family != AF_INET6)
1630 				continue;
1631 
1632 			src_scope = in6_addrscope(IFA_IN6(ifa));
1633 
1634 			/*
1635 			 * Don't use an address before completing DAD
1636 			 * nor a duplicated address.
1637 			 */
1638 			if (((struct in6_ifaddr *)ifa)->ia6_flags &
1639 			    IN6_IFF_NOTREADY)
1640 				continue;
1641 
1642 			/* XXX: is there any case to allow anycasts? */
1643 			if (((struct in6_ifaddr *)ifa)->ia6_flags &
1644 			    IN6_IFF_ANYCAST)
1645 				continue;
1646 
1647 			if (((struct in6_ifaddr *)ifa)->ia6_flags &
1648 			    IN6_IFF_DETACHED)
1649 				continue;
1650 
1651 			/*
1652 			 * If this is the first address we find,
1653 			 * keep it anyway.
1654 			 */
1655 			if (ifa_best == NULL)
1656 				goto replace;
1657 
1658 			/*
1659 			 * ifa_best is never NULL beyond this line except
1660 			 * within the block labeled "replace".
1661 			 */
1662 
1663 			/*
1664 			 * If ifa_best has a smaller scope than dst and
1665 			 * the current address has a larger one than
1666 			 * (or equal to) dst, always replace ifa_best.
1667 			 * Also, if the current address has a smaller scope
1668 			 * than dst, ignore it unless ifa_best also has a
1669 			 * smaller scope.
1670 			 */
1671 			if (IN6_ARE_SCOPE_CMP(best_scope, dst_scope) < 0 &&
1672 			    IN6_ARE_SCOPE_CMP(src_scope, dst_scope) >= 0)
1673 				goto replace;
1674 			if (IN6_ARE_SCOPE_CMP(src_scope, dst_scope) < 0 &&
1675 			    IN6_ARE_SCOPE_CMP(best_scope, dst_scope) >= 0)
1676 				continue;
1677 
1678 			/*
1679 			 * A deprecated address SHOULD NOT be used in new
1680 			 * communications if an alternate (non-deprecated)
1681 			 * address is available and has sufficient scope.
1682 			 * RFC 2462, Section 5.5.4.
1683 			 */
1684 			if (((struct in6_ifaddr *)ifa)->ia6_flags &
1685 			    IN6_IFF_DEPRECATED) {
1686 				/*
1687 				 * Ignore any deprecated addresses if
1688 				 * specified by configuration.
1689 				 */
1690 				if (!ip6_use_deprecated)
1691 					continue;
1692 
1693 				/*
1694 				 * If we have already found a non-deprecated
1695 				 * candidate, just ignore deprecated addresses.
1696 				 */
1697 				if ((ifa_best->ia6_flags & IN6_IFF_DEPRECATED)
1698 				    == 0)
1699 					continue;
1700 			}
1701 
1702 			/*
1703 			 * A non-deprecated address is always preferred
1704 			 * to a deprecated one regardless of scopes and
1705 			 * address matching.
1706 			 */
1707 			if ((ifa_best->ia6_flags & IN6_IFF_DEPRECATED) &&
1708 			    (((struct in6_ifaddr *)ifa)->ia6_flags &
1709 			     IN6_IFF_DEPRECATED) == 0)
1710 				goto replace;
1711 
1712 			/*
1713 			 * At this point, we have two cases:
1714 			 * 1. we are looking at a non-deprecated address,
1715 			 *    and ifa_best is also non-deprecated.
1716 			 * 2. we are looking at a deprecated address,
1717 			 *    and ifa_best is also deprecated.
1718 			 * Also, we do not have to consider a case where
1719 			 * the scope of if_best is larger(smaller) than dst and
1720 			 * the scope of the current address is smaller(larger)
1721 			 * than dst. Such a case has already been covered.
1722 			 * Tiebreaking is done according to the following
1723 			 * items:
1724 			 * - the scope comparison between the address and
1725 			 *   dst (dscopecmp)
1726 			 * - the scope comparison between the address and
1727 			 *   ifa_best (bscopecmp)
1728 			 * - if the address match dst longer than ifa_best
1729 			 *   (matchcmp)
1730 			 * - if the address is on the outgoing I/F (outI/F)
1731 			 *
1732 			 * Roughly speaking, the selection policy is
1733 			 * - the most important item is scope. The same scope
1734 			 *   is best. Then search for a larger scope.
1735 			 *   Smaller scopes are the last resort.
1736 			 * - A deprecated address is chosen only when we have
1737 			 *   no address that has an enough scope, but is
1738 			 *   prefered to any addresses of smaller scopes.
1739 			 * - Longest address match against dst is considered
1740 			 *   only for addresses that has the same scope of dst.
1741 			 * - If there is no other reasons to choose one,
1742 			 *   addresses on the outgoing I/F are preferred.
1743 			 *
1744 			 * The precise decision table is as follows:
1745 			 * dscopecmp bscopecmp matchcmp outI/F | replace?
1746 			 *    !equal     equal      N/A    Yes |      Yes (1)
1747 			 *    !equal     equal      N/A     No |       No (2)
1748 			 *    larger    larger      N/A    N/A |       No (3)
1749 			 *    larger   smaller      N/A    N/A |      Yes (4)
1750 			 *   smaller    larger      N/A    N/A |      Yes (5)
1751 			 *   smaller   smaller      N/A    N/A |       No (6)
1752 			 *     equal   smaller      N/A    N/A |      Yes (7)
1753 			 *     equal    larger       (already done)
1754 			 *     equal     equal   larger    N/A |      Yes (8)
1755 			 *     equal     equal  smaller    N/A |       No (9)
1756 			 *     equal     equal    equal    Yes |      Yes (a)
1757 			 *     eaual     eqaul    equal     No |       No (b)
1758 			 */
1759 			dscopecmp = IN6_ARE_SCOPE_CMP(src_scope, dst_scope);
1760 			bscopecmp = IN6_ARE_SCOPE_CMP(src_scope, best_scope);
1761 
1762 			if (dscopecmp && bscopecmp == 0) {
1763 				if (oifp == ifp) /* (1) */
1764 					goto replace;
1765 				continue; /* (2) */
1766 			}
1767 			if (dscopecmp > 0) {
1768 				if (bscopecmp > 0) /* (3) */
1769 					continue;
1770 				goto replace; /* (4) */
1771 			}
1772 			if (dscopecmp < 0) {
1773 				if (bscopecmp > 0) /* (5) */
1774 					goto replace;
1775 				continue; /* (6) */
1776 			}
1777 
1778 			/* now dscopecmp must be 0 */
1779 			if (bscopecmp < 0)
1780 				goto replace; /* (7) */
1781 
1782 			/*
1783 			 * At last both dscopecmp and bscopecmp must be 0.
1784 			 * We need address matching against dst for
1785 			 * tiebreaking.
1786 			 */
1787 			tlen = in6_matchlen(IFA_IN6(ifa), dst);
1788 			matchcmp = tlen - blen;
1789 			if (matchcmp > 0) /* (8) */
1790 				goto replace;
1791 			if (matchcmp < 0) /* (9) */
1792 				continue;
1793 			if (oifp == ifp) /* (a) */
1794 				goto replace;
1795 			continue; /* (b) */
1796 
1797 		  replace:
1798 			ifa_best = (struct in6_ifaddr *)ifa;
1799 			blen = tlen >= 0 ? tlen :
1800 				in6_matchlen(IFA_IN6(ifa), dst);
1801 			best_scope = in6_addrscope(&ifa_best->ia_addr.sin6_addr);
1802 		}
1803 	}
1804 
1805 	/* count statistics for future improvements */
1806 	if (ifa_best == NULL)
1807 		ip6stat.ip6s_sources_none++;
1808 	else {
1809 		if (oifp == ifa_best->ia_ifp)
1810 			ip6stat.ip6s_sources_sameif[best_scope]++;
1811 		else
1812 			ip6stat.ip6s_sources_otherif[best_scope]++;
1813 
1814 		if (best_scope == dst_scope)
1815 			ip6stat.ip6s_sources_samescope[best_scope]++;
1816 		else
1817 			ip6stat.ip6s_sources_otherscope[best_scope]++;
1818 
1819 		if ((ifa_best->ia6_flags & IN6_IFF_DEPRECATED) != 0)
1820 			ip6stat.ip6s_sources_deprecated[best_scope]++;
1821 	}
1822 
1823 	return(ifa_best);
1824 }
1825 
1826 /*
1827  * return the best address out of the same scope. if no address was
1828  * found, return the first valid address from designated IF.
1829  */
1830 struct in6_ifaddr *
1831 in6_ifawithifp(ifp, dst)
1832 	register struct ifnet *ifp;
1833 	register struct in6_addr *dst;
1834 {
1835 	int dst_scope =	in6_addrscope(dst), blen = -1, tlen;
1836 	struct ifaddr *ifa;
1837 	struct in6_ifaddr *besta = 0;
1838 	struct in6_ifaddr *dep[2];	/*last-resort: deprecated*/
1839 
1840 	dep[0] = dep[1] = NULL;
1841 
1842 	/*
1843 	 * We first look for addresses in the same scope.
1844 	 * If there is one, return it.
1845 	 * If two or more, return one which matches the dst longest.
1846 	 * If none, return one of global addresses assigned other ifs.
1847 	 */
1848 	TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list)
1849 	{
1850 		if (ifa->ifa_addr->sa_family != AF_INET6)
1851 			continue;
1852 		if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST)
1853 			continue; /* XXX: is there any case to allow anycast? */
1854 		if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_NOTREADY)
1855 			continue; /* don't use this interface */
1856 		if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DETACHED)
1857 			continue;
1858 		if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DEPRECATED) {
1859 			if (ip6_use_deprecated)
1860 				dep[0] = (struct in6_ifaddr *)ifa;
1861 			continue;
1862 		}
1863 
1864 		if (dst_scope == in6_addrscope(IFA_IN6(ifa))) {
1865 			/*
1866 			 * call in6_matchlen() as few as possible
1867 			 */
1868 			if (besta) {
1869 				if (blen == -1)
1870 					blen = in6_matchlen(&besta->ia_addr.sin6_addr, dst);
1871 				tlen = in6_matchlen(IFA_IN6(ifa), dst);
1872 				if (tlen > blen) {
1873 					blen = tlen;
1874 					besta = (struct in6_ifaddr *)ifa;
1875 				}
1876 			} else
1877 				besta = (struct in6_ifaddr *)ifa;
1878 		}
1879 	}
1880 	if (besta)
1881 		return(besta);
1882 
1883 	TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list)
1884 	{
1885 		if (ifa->ifa_addr->sa_family != AF_INET6)
1886 			continue;
1887 		if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST)
1888 			continue; /* XXX: is there any case to allow anycast? */
1889 		if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_NOTREADY)
1890 			continue; /* don't use this interface */
1891 		if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DETACHED)
1892 			continue;
1893 		if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DEPRECATED) {
1894 			if (ip6_use_deprecated)
1895 				dep[1] = (struct in6_ifaddr *)ifa;
1896 			continue;
1897 		}
1898 
1899 		return (struct in6_ifaddr *)ifa;
1900 	}
1901 
1902 	/* use the last-resort values, that are, deprecated addresses */
1903 	if (dep[0])
1904 		return dep[0];
1905 	if (dep[1])
1906 		return dep[1];
1907 
1908 	return NULL;
1909 }
1910 
1911 /*
1912  * perform DAD when interface becomes IFF_UP.
1913  */
1914 void
1915 in6_if_up(ifp)
1916 	struct ifnet *ifp;
1917 {
1918 	struct ifaddr *ifa;
1919 	struct in6_ifaddr *ia;
1920 	int dad_delay;		/* delay ticks before DAD output */
1921 
1922 	/*
1923 	 * special cases, like 6to4, are handled in in6_ifattach
1924 	 */
1925 	in6_ifattach(ifp, NULL);
1926 
1927 	dad_delay = 0;
1928 	TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list)
1929 	{
1930 		if (ifa->ifa_addr->sa_family != AF_INET6)
1931 			continue;
1932 		ia = (struct in6_ifaddr *)ifa;
1933 		if (ia->ia6_flags & IN6_IFF_TENTATIVE)
1934 			nd6_dad_start(ifa, &dad_delay);
1935 	}
1936 }
1937 
1938 /*
1939  * Calculate max IPv6 MTU through all the interfaces and store it
1940  * to in6_maxmtu.
1941  */
1942 void
1943 in6_setmaxmtu()
1944 {
1945 	unsigned long maxmtu = 0;
1946 	struct ifnet *ifp;
1947 
1948 	for (ifp = TAILQ_FIRST(&ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list))
1949 	{
1950 		if ((ifp->if_flags & IFF_LOOPBACK) == 0 &&
1951 		    nd_ifinfo[ifp->if_index].linkmtu > maxmtu)
1952 			maxmtu =  nd_ifinfo[ifp->if_index].linkmtu;
1953 	}
1954 	if (maxmtu)	/* update only when maxmtu is positive */
1955 		in6_maxmtu = maxmtu;
1956 }
1957 
1958 /*
1959  * Convert sockaddr_in6 to sockaddr_in. Original sockaddr_in6 must be
1960  * v4 mapped addr or v4 compat addr
1961  */
1962 void
1963 in6_sin6_2_sin(struct sockaddr_in *sin, struct sockaddr_in6 *sin6)
1964 {
1965 	bzero(sin, sizeof(*sin));
1966 	sin->sin_len = sizeof(struct sockaddr_in);
1967 	sin->sin_family = AF_INET;
1968 	sin->sin_port = sin6->sin6_port;
1969 	sin->sin_addr.s_addr = sin6->sin6_addr.s6_addr32[3];
1970 }
1971 
1972 /* Convert sockaddr_in to sockaddr_in6 in v4 mapped addr format. */
1973 void
1974 in6_sin_2_v4mapsin6(struct sockaddr_in *sin, struct sockaddr_in6 *sin6)
1975 {
1976 	bzero(sin6, sizeof(*sin6));
1977 	sin6->sin6_len = sizeof(struct sockaddr_in6);
1978 	sin6->sin6_family = AF_INET6;
1979 	sin6->sin6_port = sin->sin_port;
1980 	sin6->sin6_addr.s6_addr32[0] = 0;
1981 	sin6->sin6_addr.s6_addr32[1] = 0;
1982 	sin6->sin6_addr.s6_addr32[2] = IPV6_ADDR_INT32_SMP;
1983 	sin6->sin6_addr.s6_addr32[3] = sin->sin_addr.s_addr;
1984 }
1985 
1986 /* Convert sockaddr_in6 into sockaddr_in. */
1987 void
1988 in6_sin6_2_sin_in_sock(struct sockaddr *nam)
1989 {
1990 	struct sockaddr_in *sin_p;
1991 	struct sockaddr_in6 sin6;
1992 
1993 	/*
1994 	 * Save original sockaddr_in6 addr and convert it
1995 	 * to sockaddr_in.
1996 	 */
1997 	sin6 = *(struct sockaddr_in6 *)nam;
1998 	sin_p = (struct sockaddr_in *)nam;
1999 	in6_sin6_2_sin(sin_p, &sin6);
2000 }
2001 
2002 /* Convert sockaddr_in into sockaddr_in6 in v4 mapped addr format. */
2003 void
2004 in6_sin_2_v4mapsin6_in_sock(struct sockaddr **nam)
2005 {
2006 	struct sockaddr_in *sin_p;
2007 	struct sockaddr_in6 *sin6_p;
2008 
2009 	MALLOC(sin6_p, struct sockaddr_in6 *, sizeof *sin6_p, M_SONAME,
2010 	       M_WAITOK);
2011 	sin_p = (struct sockaddr_in *)*nam;
2012 	in6_sin_2_v4mapsin6(sin_p, sin6_p);
2013 	FREE(*nam, M_SONAME);
2014 	*nam = (struct sockaddr *)sin6_p;
2015 }
2016