xref: /openbsd-src/sys/netinet6/in6.c (revision b2ea75c1b17e1a9a339660e7ed45cd24946b230e)
1 /*	$OpenBSD: in6.c,v 1.29 2001/07/18 12:50:44 itojun Exp $	*/
2 /*	$KAME: in6.c,v 1.198 2001/07/18 09:12:38 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 <sys/param.h>
69 #include <sys/ioctl.h>
70 #include <sys/errno.h>
71 #include <sys/malloc.h>
72 #include <sys/socket.h>
73 #include <sys/socketvar.h>
74 #include <sys/sockio.h>
75 #include <sys/systm.h>
76 #include <sys/proc.h>
77 #include <sys/time.h>
78 #include <sys/kernel.h>
79 #include <sys/syslog.h>
80 
81 #include <net/if.h>
82 #include <net/if_types.h>
83 #include <net/route.h>
84 #include <net/if_dl.h>
85 
86 #include <netinet/in.h>
87 #include <netinet/in_var.h>
88 #include <netinet/if_ether.h>
89 
90 #include <netinet/ip6.h>
91 #include <netinet6/ip6_var.h>
92 #include <netinet6/nd6.h>
93 #include <netinet6/mld6_var.h>
94 #include <netinet6/ip6_mroute.h>
95 #include <netinet6/in6_ifattach.h>
96 
97 /* backward compatibility for a while... */
98 #define COMPAT_IN6IFIOCTL
99 
100 /*
101  * Definitions of some costant IP6 addresses.
102  */
103 const struct in6_addr in6addr_any = IN6ADDR_ANY_INIT;
104 const struct in6_addr in6addr_loopback = IN6ADDR_LOOPBACK_INIT;
105 const struct in6_addr in6addr_nodelocal_allnodes =
106 	IN6ADDR_NODELOCAL_ALLNODES_INIT;
107 const struct in6_addr in6addr_linklocal_allnodes =
108 	IN6ADDR_LINKLOCAL_ALLNODES_INIT;
109 const struct in6_addr in6addr_linklocal_allrouters =
110 	IN6ADDR_LINKLOCAL_ALLROUTERS_INIT;
111 
112 const struct in6_addr in6mask0 = IN6MASK0;
113 const struct in6_addr in6mask32 = IN6MASK32;
114 const struct in6_addr in6mask64 = IN6MASK64;
115 const struct in6_addr in6mask96 = IN6MASK96;
116 const struct in6_addr in6mask128 = IN6MASK128;
117 
118 static int in6_lifaddr_ioctl __P((struct socket *, u_long, caddr_t,
119 	struct ifnet *, struct proc *));
120 
121 const struct sockaddr_in6 sa6_any = {sizeof(sa6_any), AF_INET6,
122 				     0, 0, IN6ADDR_ANY_INIT, 0};
123 
124 /*
125  * This structure is used to keep track of in6_multi chains which belong to
126  * deleted interface addresses.
127  */
128 static LIST_HEAD(, multi6_kludge) in6_mk; /* XXX BSS initialization */
129 
130 struct multi6_kludge {
131 	LIST_ENTRY(multi6_kludge) mk_entry;
132 	struct ifnet *mk_ifp;
133 	struct in6_multihead mk_head;
134 };
135 
136 /*
137  * Check if the loopback entry will be automatically generated.
138  *   if 0 returned, will not be automatically generated.
139  *   if 1 returned, will be automatically generated.
140  */
141 static int
142 in6_is_ifloop_auto(struct ifaddr *ifa)
143 {
144 	return 0;
145 }
146 
147 /*
148  * Subroutine for in6_ifaddloop() and in6_ifremloop().
149  * This routine does actual work.
150  */
151 static void
152 in6_ifloop_request(int cmd, struct ifaddr *ifa)
153 {
154 	struct sockaddr_in6 lo_sa;
155 	struct sockaddr_in6 all1_sa;
156 	struct rtentry *nrt = NULL, **nrtp = NULL;
157 
158 	bzero(&lo_sa, sizeof(lo_sa));
159 	bzero(&all1_sa, sizeof(all1_sa));
160 	lo_sa.sin6_family = AF_INET6;
161 	lo_sa.sin6_len = sizeof(struct sockaddr_in6);
162 	all1_sa = lo_sa;
163 	lo_sa.sin6_addr = in6addr_loopback;
164 	all1_sa.sin6_addr = in6mask128;
165 
166 	/*
167 	 * So we add or remove static loopback entry, here.
168 	 * This request for deletion could fail, e.g. when we remove
169 	 * an address right after adding it.
170 	 */
171 	if (cmd == RTM_ADD)
172 		nrtp = &nrt;
173 	rtrequest(cmd, ifa->ifa_addr,
174 		  (struct sockaddr *)&lo_sa,
175 		  (struct sockaddr *)&all1_sa,
176 		  RTF_UP|RTF_HOST, nrtp);
177 
178 	/*
179 	 * Make sure rt_ifa be equal to IFA, the second argument of the
180 	 * function.
181 	 * We need this because when we refer rt_ifa->ia6_flags in ip6_input,
182 	 * we assume that the rt_ifa points to the address instead of the
183 	 * loopback address.
184 	 */
185 	if (cmd == RTM_ADD && nrt && ifa != nrt->rt_ifa) {
186 		IFAFREE(nrt->rt_ifa);
187 		ifa->ifa_refcnt++;
188 		nrt->rt_ifa = ifa;
189 	}
190 	if (nrt)
191 		nrt->rt_refcnt--;
192 }
193 
194 /*
195  * Add ownaddr as loopback rtentry, if necessary(ex. on p2p link).
196  * Because, KAME needs loopback rtentry for ownaddr check in
197  * ip6_input().
198  */
199 static void
200 in6_ifaddloop(struct ifaddr *ifa)
201 {
202 	if (!in6_is_ifloop_auto(ifa)) {
203 		struct rtentry *rt;
204 
205 		/* If there is no loopback entry, allocate one. */
206 		rt = rtalloc1(ifa->ifa_addr, 0);
207 		if (rt == 0 || (rt->rt_ifp->if_flags & IFF_LOOPBACK) == 0)
208 			in6_ifloop_request(RTM_ADD, ifa);
209 		if (rt)
210 			rt->rt_refcnt--;
211 	}
212 }
213 
214 /*
215  * Remove loopback rtentry of ownaddr generated by in6_ifaddloop(),
216  * if it exists.
217  */
218 static void
219 in6_ifremloop(struct ifaddr *ifa)
220 {
221 	if (!in6_is_ifloop_auto(ifa)) {
222 		struct in6_ifaddr *ia;
223 		int ia_count = 0;
224 
225 		/* If only one ifa for the loopback entry, delete it. */
226 		for (ia = in6_ifaddr; ia; ia = ia->ia_next) {
227 			if (IN6_ARE_ADDR_EQUAL(IFA_IN6(ifa),
228 					       &ia->ia_addr.sin6_addr)) {
229 				ia_count++;
230 				if (ia_count > 1)
231 					break;
232 			}
233 		}
234 		if (ia_count == 1)
235 			in6_ifloop_request(RTM_DELETE, ifa);
236 	}
237 }
238 
239 int
240 in6_ifindex2scopeid(idx)
241 	int idx;
242 {
243 	struct ifnet *ifp;
244 	struct ifaddr *ifa;
245 	struct sockaddr_in6 *sin6;
246 
247 	if (idx < 0 || if_index < idx)
248 		return -1;
249 	ifp = ifindex2ifnet[idx];
250 
251 	for (ifa = ifp->if_addrlist.tqh_first; ifa; ifa = ifa->ifa_list.tqe_next)
252 	{
253 		if (ifa->ifa_addr->sa_family != AF_INET6)
254 			continue;
255 		sin6 = (struct sockaddr_in6 *)ifa->ifa_addr;
256 		if (IN6_IS_ADDR_SITELOCAL(&sin6->sin6_addr))
257 			return sin6->sin6_scope_id & 0xffff;
258 	}
259 
260 	return -1;
261 }
262 
263 int
264 in6_mask2len(mask)
265 	struct in6_addr *mask;
266 {
267 	int x, y;
268 
269 	for (x = 0; x < sizeof(*mask); x++) {
270 		if (mask->s6_addr8[x] != 0xff)
271 			break;
272 	}
273 	y = 0;
274 	if (x < sizeof(*mask)) {
275 		for (y = 0; y < 8; y++) {
276 			if ((mask->s6_addr8[x] & (0x80 >> y)) == 0)
277 				break;
278 		}
279 	}
280 	return x * 8 + y;
281 }
282 
283 void
284 in6_len2mask(mask, len)
285 	struct in6_addr *mask;
286 	int len;
287 {
288 	int i;
289 
290 	bzero(mask, sizeof(*mask));
291 	for (i = 0; i < len / 8; i++)
292 		mask->s6_addr8[i] = 0xff;
293 	if (len % 8)
294 		mask->s6_addr8[i] = (0xff00 >> (len % 8)) & 0xff;
295 }
296 
297 #define ifa2ia6(ifa)	((struct in6_ifaddr *)(ifa))
298 #define ia62ifa(ia6)	(&((ia6)->ia_ifa))
299 
300 int
301 in6_control(so, cmd, data, ifp, p)
302 	struct	socket *so;
303 	u_long cmd;
304 	caddr_t	data;
305 	struct ifnet *ifp;
306 	struct proc *p;
307 {
308 	struct	in6_ifreq *ifr = (struct in6_ifreq *)data;
309 	struct	in6_ifaddr *ia, *oia;
310 	struct	in6_aliasreq *ifra = (struct in6_aliasreq *)data;
311 	struct	sockaddr_in6 oldaddr;
312 #ifdef COMPAT_IN6IFIOCTL
313 	struct	sockaddr_in6 net;
314 #endif
315 	int error = 0, hostIsNew, prefixIsNew;
316 	int newifaddr;
317 	time_t time_second = (time_t)time.tv_sec;
318 	int privileged;
319 
320 	privileged = 0;
321 	if ((so->so_state & SS_PRIV) != 0)
322 		privileged++;
323 
324 	switch (cmd) {
325 	case SIOCGETSGCNT_IN6:
326 	case SIOCGETMIFCNT_IN6:
327 		return (mrt6_ioctl(cmd, data));
328 	}
329 
330 	if (ifp == 0)
331 		return(EOPNOTSUPP);
332 
333 	switch (cmd) {
334 	case SIOCSNDFLUSH_IN6:
335 	case SIOCSPFXFLUSH_IN6:
336 	case SIOCSRTRFLUSH_IN6:
337 	case SIOCSDEFIFACE_IN6:
338 	case SIOCSIFINFO_FLAGS:
339 		if (!privileged)
340 			return(EPERM);
341 		/*fall through*/
342 	case SIOCGIFINFO_IN6:
343 	case SIOCGDRLST_IN6:
344 	case SIOCGPRLST_IN6:
345 	case SIOCGNBRINFO_IN6:
346 	case SIOCGDEFIFACE_IN6:
347 		return(nd6_ioctl(cmd, data, ifp));
348 	}
349 
350 	switch (cmd) {
351 	case SIOCSIFPREFIX_IN6:
352 	case SIOCDIFPREFIX_IN6:
353 	case SIOCAIFPREFIX_IN6:
354 	case SIOCCIFPREFIX_IN6:
355 	case SIOCSGIFPREFIX_IN6:
356 		if (!privileged)
357 			return(EPERM);
358 		/*fall through*/
359 	case SIOCGIFPREFIX_IN6:
360 		return(in6_prefix_ioctl(so, cmd, data, ifp));
361 	}
362 
363 	switch (cmd) {
364 	case SIOCALIFADDR:
365 	case SIOCDLIFADDR:
366 		if (!privileged)
367 			return(EPERM);
368 		/*fall through*/
369 	case SIOCGLIFADDR:
370 		return in6_lifaddr_ioctl(so, cmd, data, ifp, p);
371 	}
372 
373 	/*
374 	 * Find address for this interface, if it exists.
375 	 */
376 	if (ifra->ifra_addr.sin6_family == AF_INET6) { /* XXX */
377 		struct sockaddr_in6 *sa6 =
378 			(struct sockaddr_in6 *)&ifra->ifra_addr;
379 
380 		if (IN6_IS_ADDR_LINKLOCAL(&sa6->sin6_addr)) {
381 			if (sa6->sin6_addr.s6_addr16[1] == 0) {
382 				/* interface ID is not embedded by the user */
383 				sa6->sin6_addr.s6_addr16[1] =
384 					htons(ifp->if_index);
385 			} else if (sa6->sin6_addr.s6_addr16[1] !=
386 				    htons(ifp->if_index)) {
387 				return(EINVAL);	/* ifid contradicts */
388 			}
389 			if (sa6->sin6_scope_id) {
390 				if (sa6->sin6_scope_id !=
391 				    (u_int32_t)ifp->if_index)
392 					return(EINVAL);
393 				sa6->sin6_scope_id = 0; /* XXX: good way? */
394 			}
395 		}
396 		ia = in6ifa_ifpwithaddr(ifp, &ifra->ifra_addr.sin6_addr);
397 	}
398 
399 	switch (cmd) {
400 
401 	case SIOCDIFADDR_IN6:
402 		/*
403 		 * for IPv4, we look for existing in_ifaddr here to allow
404 		 * "ifconfig if0 delete" to remove first IPv4 address on the
405 		 * interface.  For IPv6, as the spec allow multiple interface
406 		 * address from the day one, we consider "remove the first one"
407 		 * semantics to be not preferable.
408 		 */
409 		if (ia == NULL)
410 			return(EADDRNOTAVAIL);
411 		/* FALLTHROUGH */
412 	case SIOCAIFADDR_IN6:
413 	case SIOCSIFADDR_IN6:
414 #ifdef COMPAT_IN6IFIOCTL
415 	case SIOCSIFDSTADDR_IN6:
416 	case SIOCSIFNETMASK_IN6:
417 		/*
418 		 * Since IPv6 allows a node to assign multiple addresses
419 		 * on a single interface, SIOCSIFxxx ioctls are not suitable
420 		 * and should be unused.
421 		 */
422 #endif
423 		if (ifra->ifra_addr.sin6_family != AF_INET6)
424 			return(EAFNOSUPPORT);
425 		if (!privileged)
426 			return(EPERM);
427 		if (ia == NULL) {
428 			ia = (struct in6_ifaddr *)
429 				malloc(sizeof(*ia), M_IFADDR, M_WAITOK);
430 			bzero((caddr_t)ia, sizeof(*ia));
431 			/* Initialize the address and masks */
432 			ia->ia_ifa.ifa_addr = (struct sockaddr *)&ia->ia_addr;
433 			ia->ia_addr.sin6_family = AF_INET6;
434 			ia->ia_addr.sin6_len = sizeof(ia->ia_addr);
435 			if (ifp->if_flags & IFF_POINTOPOINT) {
436 				ia->ia_ifa.ifa_dstaddr
437 					= (struct sockaddr *)&ia->ia_dstaddr;
438 				ia->ia_dstaddr.sin6_family = AF_INET6;
439 				ia->ia_dstaddr.sin6_len = sizeof(ia->ia_dstaddr);
440 			} else {
441 				ia->ia_ifa.ifa_dstaddr = NULL;
442 				bzero(&ia->ia_dstaddr, sizeof(ia->ia_dstaddr));
443 			}
444 			ia->ia_ifa.ifa_netmask
445 				= (struct sockaddr *)&ia->ia_prefixmask;
446 
447 			ia->ia_ifp = ifp;
448 			if ((oia = in6_ifaddr) != NULL) {
449 				for ( ; oia->ia_next; oia = oia->ia_next)
450 					continue;
451 				oia->ia_next = ia;
452 			} else
453 				in6_ifaddr = ia;
454 			ia->ia_ifa.ifa_refcnt++;
455 
456 			TAILQ_INSERT_TAIL(&ifp->if_addrlist,
457 				(struct ifaddr *)ia, ifa_list);
458 			ia->ia_ifa.ifa_refcnt++;
459 
460 			newifaddr = 1;
461 		} else
462 			newifaddr = 0;
463 
464 		if (cmd == SIOCAIFADDR_IN6) {
465 			/* sanity for overflow - beware unsigned */
466 			struct in6_addrlifetime *lt;
467 			lt = &ifra->ifra_lifetime;
468 			if (lt->ia6t_vltime != ND6_INFINITE_LIFETIME
469 			 && lt->ia6t_vltime + time_second < time_second) {
470 				return EINVAL;
471 			}
472 			if (lt->ia6t_pltime != ND6_INFINITE_LIFETIME
473 			 && lt->ia6t_pltime + time_second < time_second) {
474 				return EINVAL;
475 			}
476 		}
477 		break;
478 
479 	case SIOCGIFADDR_IN6:
480 		/* This interface is basically deprecated. use SIOCGIFCONF. */
481 		/* fall through */
482 	case SIOCGIFAFLAG_IN6:
483 	case SIOCGIFNETMASK_IN6:
484 	case SIOCGIFDSTADDR_IN6:
485 	case SIOCGIFALIFETIME_IN6:
486 		/* must think again about its semantics */
487 		if (ia == NULL)
488 			return(EADDRNOTAVAIL);
489 		break;
490 	case SIOCSIFALIFETIME_IN6:
491 	    {
492 		struct in6_addrlifetime *lt;
493 
494 		if (!privileged)
495 			return(EPERM);
496 		if (ia == NULL)
497 			return(EADDRNOTAVAIL);
498 		/* sanity for overflow - beware unsigned */
499 		lt = &ifr->ifr_ifru.ifru_lifetime;
500 		if (lt->ia6t_vltime != ND6_INFINITE_LIFETIME
501 		 && lt->ia6t_vltime + time_second < time_second) {
502 			return EINVAL;
503 		}
504 		if (lt->ia6t_pltime != ND6_INFINITE_LIFETIME
505 		 && lt->ia6t_pltime + time_second < time_second) {
506 			return EINVAL;
507 		}
508 		break;
509 	    }
510 	}
511 
512 	switch (cmd) {
513 
514 	case SIOCGIFADDR_IN6:
515 		ifr->ifr_addr = ia->ia_addr;
516 		break;
517 
518 	case SIOCGIFDSTADDR_IN6:
519 		if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
520 			return(EINVAL);
521 		ifr->ifr_dstaddr = ia->ia_dstaddr;
522 		break;
523 
524 	case SIOCGIFNETMASK_IN6:
525 		ifr->ifr_addr = ia->ia_prefixmask;
526 		break;
527 
528 	case SIOCGIFAFLAG_IN6:
529 		ifr->ifr_ifru.ifru_flags6 = ia->ia6_flags;
530 		break;
531 
532 	case SIOCGIFSTAT_IN6:
533 		if (ifp == NULL)
534 			return EINVAL;
535 		if (in6_ifstat == NULL || ifp->if_index >= in6_ifstatmax
536 		 || in6_ifstat[ifp->if_index] == NULL) {
537 			/* return EAFNOSUPPORT? */
538 			bzero(&ifr->ifr_ifru.ifru_stat,
539 				sizeof(ifr->ifr_ifru.ifru_stat));
540 		} else
541 			ifr->ifr_ifru.ifru_stat = *in6_ifstat[ifp->if_index];
542 		break;
543 
544 	case SIOCGIFSTAT_ICMP6:
545 		if (ifp == NULL)
546 			return EINVAL;
547 		if (icmp6_ifstat == NULL || ifp->if_index >= icmp6_ifstatmax ||
548 		    icmp6_ifstat[ifp->if_index] == NULL) {
549 			/* return EAFNOSUPPORT? */
550 			bzero(&ifr->ifr_ifru.ifru_stat,
551 				sizeof(ifr->ifr_ifru.ifru_icmp6stat));
552 		} else
553 			ifr->ifr_ifru.ifru_icmp6stat =
554 				*icmp6_ifstat[ifp->if_index];
555 		break;
556 
557 #ifdef COMPAT_IN6IFIOCTL		/* should be unused */
558 	case SIOCSIFDSTADDR_IN6:
559 		if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
560 			return(EINVAL);
561 		oldaddr = ia->ia_dstaddr;
562 		ia->ia_dstaddr = ifr->ifr_dstaddr;
563 
564 		/* link-local index check */
565 		if (IN6_IS_ADDR_LINKLOCAL(&ia->ia_dstaddr.sin6_addr)) {
566 			if (ia->ia_dstaddr.sin6_addr.s6_addr16[1] == 0) {
567 				/* interface ID is not embedded by the user */
568 				ia->ia_dstaddr.sin6_addr.s6_addr16[1]
569 					= htons(ifp->if_index);
570 			} else if (ia->ia_dstaddr.sin6_addr.s6_addr16[1] !=
571 				    htons(ifp->if_index)) {
572 				ia->ia_dstaddr = oldaddr;
573 				return(EINVAL);	/* ifid contradicts */
574 			}
575 		}
576 
577 		if (ifp->if_ioctl && (error = (ifp->if_ioctl)
578 				      (ifp, SIOCSIFDSTADDR, (caddr_t)ia))) {
579 			ia->ia_dstaddr = oldaddr;
580 			return(error);
581 		}
582 		if (ia->ia_flags & IFA_ROUTE) {
583 			ia->ia_ifa.ifa_dstaddr = (struct sockaddr *)&oldaddr;
584 			rtinit(&(ia->ia_ifa), (int)RTM_DELETE, RTF_HOST);
585 			ia->ia_ifa.ifa_dstaddr =
586 				(struct sockaddr *)&ia->ia_dstaddr;
587 			rtinit(&(ia->ia_ifa), (int)RTM_ADD, RTF_HOST|RTF_UP);
588 		}
589 		break;
590 
591 #endif
592 	case SIOCGIFALIFETIME_IN6:
593 		ifr->ifr_ifru.ifru_lifetime = ia->ia6_lifetime;
594 		break;
595 
596 	case SIOCSIFALIFETIME_IN6:
597 		ia->ia6_lifetime = ifr->ifr_ifru.ifru_lifetime;
598 		/* for sanity */
599 		if (ia->ia6_lifetime.ia6t_vltime != ND6_INFINITE_LIFETIME) {
600 			ia->ia6_lifetime.ia6t_expire =
601 				time_second + ia->ia6_lifetime.ia6t_vltime;
602 		} else
603 			ia->ia6_lifetime.ia6t_expire = 0;
604 		if (ia->ia6_lifetime.ia6t_pltime != ND6_INFINITE_LIFETIME) {
605 			ia->ia6_lifetime.ia6t_preferred =
606 				time_second + ia->ia6_lifetime.ia6t_pltime;
607 		} else
608 			ia->ia6_lifetime.ia6t_preferred = 0;
609 		break;
610 
611 	case SIOCSIFADDR_IN6:
612 		error = in6_ifinit(ifp, ia, &ifr->ifr_addr, 1);
613 #if 0
614 		/*
615 		 * the code chokes if we are to assign multiple addresses with
616 		 * the same address prefix (rtinit() will return EEXIST, which
617 		 * is not fatal actually).  we will get memory leak if we
618 		 * don't do it.
619 		 * -> we may want to hide EEXIST from rtinit().
620 		 */
621   undo:
622 		if (error && newifaddr) {
623 			TAILQ_REMOVE(&ifp->if_addrlist, &ia->ia_ifa, ifa_list);
624 			IFAFREE(&ia->ia_ifa);
625 
626 			oia = ia;
627 			if (oia == (ia = in6_ifaddr))
628 				in6_ifaddr = ia->ia_next;
629 			else {
630 				while (ia->ia_next && (ia->ia_next != oia))
631 					ia = ia->ia_next;
632 				if (ia->ia_next)
633 					ia->ia_next = oia->ia_next;
634 				else {
635 					printf("Didn't unlink in6_ifaddr "
636 					    "from list\n");
637 				}
638 			}
639 			IFAFREE(&oia->ia_ifa);
640 		}
641 #endif
642 		return error;
643 
644 #ifdef COMPAT_IN6IFIOCTL		/* XXX should be unused */
645 	case SIOCSIFNETMASK_IN6:
646 		ia->ia_prefixmask = ifr->ifr_addr;
647 		bzero(&net, sizeof(net));
648 		net.sin6_len = sizeof(struct sockaddr_in6);
649 		net.sin6_family = AF_INET6;
650 		net.sin6_port = htons(0);
651 		net.sin6_flowinfo = htonl(0);
652 		net.sin6_addr.s6_addr32[0]
653 			= ia->ia_addr.sin6_addr.s6_addr32[0] &
654 				ia->ia_prefixmask.sin6_addr.s6_addr32[0];
655 		net.sin6_addr.s6_addr32[1]
656 			= ia->ia_addr.sin6_addr.s6_addr32[1] &
657 				ia->ia_prefixmask.sin6_addr.s6_addr32[1];
658 		net.sin6_addr.s6_addr32[2]
659 			= ia->ia_addr.sin6_addr.s6_addr32[2] &
660 				ia->ia_prefixmask.sin6_addr.s6_addr32[2];
661 		net.sin6_addr.s6_addr32[3]
662 			= ia->ia_addr.sin6_addr.s6_addr32[3] &
663 				ia->ia_prefixmask.sin6_addr.s6_addr32[3];
664 		ia->ia_net = net;
665 		break;
666 #endif
667 
668 	case SIOCAIFADDR_IN6:
669 		prefixIsNew = 0;
670 		hostIsNew = 1;
671 
672 		if (ifra->ifra_addr.sin6_len == 0) {
673 			ifra->ifra_addr = ia->ia_addr;
674 			hostIsNew = 0;
675 		} else if (IN6_ARE_ADDR_EQUAL(&ifra->ifra_addr.sin6_addr,
676 					      &ia->ia_addr.sin6_addr))
677 			hostIsNew = 0;
678 
679 		/* Validate address families: */
680 		/*
681 		 * The destination address for a p2p link must have a family
682 		 * of AF_UNSPEC or AF_INET6.
683 		 */
684 		if ((ifp->if_flags & IFF_POINTOPOINT) != 0 &&
685 		    ifra->ifra_dstaddr.sin6_family != AF_INET6 &&
686 		    ifra->ifra_dstaddr.sin6_family != AF_UNSPEC)
687 			return(EAFNOSUPPORT);
688 		/*
689 		 * The prefixmask must have a family of AF_UNSPEC or AF_INET6.
690 		 */
691 		if (ifra->ifra_prefixmask.sin6_family != AF_INET6 &&
692 		    ifra->ifra_prefixmask.sin6_family != AF_UNSPEC)
693 			return(EAFNOSUPPORT);
694 
695 		if (ifra->ifra_prefixmask.sin6_len) {
696 			in6_ifscrub(ifp, ia);
697 			ia->ia_prefixmask = ifra->ifra_prefixmask;
698 			prefixIsNew = 1;
699 		}
700 		if ((ifp->if_flags & IFF_POINTOPOINT) &&
701 		    (ifra->ifra_dstaddr.sin6_family == AF_INET6)) {
702 			in6_ifscrub(ifp, ia);
703 			oldaddr = ia->ia_dstaddr;
704 			ia->ia_dstaddr = ifra->ifra_dstaddr;
705 			/* link-local index check: should be a separate function? */
706 			if (IN6_IS_ADDR_LINKLOCAL(&ia->ia_dstaddr.sin6_addr)) {
707 				if (ia->ia_dstaddr.sin6_addr.s6_addr16[1] == 0) {
708 					/*
709 					 * interface ID is not embedded by
710 					 * the user
711 					 */
712 					ia->ia_dstaddr.sin6_addr.s6_addr16[1]
713 						= htons(ifp->if_index);
714 				} else if (ia->ia_dstaddr.sin6_addr.s6_addr16[1] !=
715 					    htons(ifp->if_index)) {
716 					ia->ia_dstaddr = oldaddr;
717 					return(EINVAL);	/* ifid contradicts */
718 				}
719 			}
720 			prefixIsNew = 1; /* We lie; but effect's the same */
721 		}
722 		if (hostIsNew || prefixIsNew) {
723 			error = in6_ifinit(ifp, ia, &ifra->ifra_addr, 0);
724 #if 0
725 			if (error)
726 				goto undo;
727 #endif
728 		}
729 		if (hostIsNew && (ifp->if_flags & IFF_MULTICAST)) {
730 			int error_local = 0;
731 
732 			/*
733 			 * join solicited multicast addr for new host id
734 			 */
735 			struct in6_addr llsol;
736 			bzero(&llsol, sizeof(struct in6_addr));
737 			llsol.s6_addr16[0] = htons(0xff02);
738 			llsol.s6_addr16[1] = htons(ifp->if_index);
739 			llsol.s6_addr32[1] = 0;
740 			llsol.s6_addr32[2] = htonl(1);
741 			llsol.s6_addr32[3] =
742 				ifra->ifra_addr.sin6_addr.s6_addr32[3];
743 			llsol.s6_addr8[12] = 0xff;
744 			(void)in6_addmulti(&llsol, ifp, &error_local);
745 			if (error == 0)
746 				error = error_local;
747 		}
748 
749 		ia->ia6_flags = ifra->ifra_flags;
750 		ia->ia6_flags &= ~IN6_IFF_DUPLICATED;	/*safety*/
751 
752 		ia->ia6_lifetime = ifra->ifra_lifetime;
753 		/* for sanity */
754 		if (ia->ia6_lifetime.ia6t_vltime != ND6_INFINITE_LIFETIME) {
755 			ia->ia6_lifetime.ia6t_expire =
756 				time_second + ia->ia6_lifetime.ia6t_vltime;
757 		} else
758 			ia->ia6_lifetime.ia6t_expire = 0;
759 		if (ia->ia6_lifetime.ia6t_pltime != ND6_INFINITE_LIFETIME) {
760 			ia->ia6_lifetime.ia6t_preferred =
761 				time_second + ia->ia6_lifetime.ia6t_pltime;
762 		} else
763 			ia->ia6_lifetime.ia6t_preferred = 0;
764 
765 		/*
766 		 * make sure to initialize ND6 information.  this is to
767 		 * workaround issues with interfaces with IPv6 addresses,
768 		 * which have never brought # up.  we are assuming that it is
769 		 * safe to nd6_ifattach multiple times.
770 		 */
771 		nd6_ifattach(ifp);
772 
773 		/*
774 		 * Perform DAD, if needed.
775 		 * XXX It may be of use, if we can administratively
776 		 * disable DAD.
777 		 */
778 		switch (ifp->if_type) {
779 		case IFT_ARCNET:
780 		case IFT_ETHER:
781 		case IFT_FDDI:
782 #if 0
783 		case IFT_ATM:
784 		case IFT_SLIP:
785 		case IFT_PPP:
786 #endif
787 			ia->ia6_flags |= IN6_IFF_TENTATIVE;
788 			nd6_dad_start((struct ifaddr *)ia, NULL);
789 			break;
790 		case IFT_DUMMY:
791 		case IFT_FAITH:
792 		case IFT_GIF:
793 		case IFT_LOOP:
794 		default:
795 			break;
796 		}
797 
798 		if (hostIsNew) {
799 			int iilen;
800 			int error_local = 0;
801 
802 			iilen = (sizeof(ia->ia_prefixmask.sin6_addr) << 3) -
803 				in6_mask2len(&ia->ia_prefixmask.sin6_addr);
804 			error_local = in6_prefix_add_ifid(iilen, ia);
805 			if (error == 0)
806 				error = error_local;
807 		}
808 
809 		return(error);
810 
811 	case SIOCDIFADDR_IN6:
812 		in6_purgeaddr(&ia->ia_ifa, ifp);
813 		break;
814 
815 	default:
816 		if (ifp == NULL || ifp->if_ioctl == 0)
817 			return(EOPNOTSUPP);
818 		return((*ifp->if_ioctl)(ifp, cmd, data));
819 	}
820 	return(0);
821 }
822 
823 void
824 in6_purgeaddr(ifa, ifp)
825 	struct ifaddr *ifa;
826 	struct ifnet *ifp;
827 {
828 	struct in6_ifaddr *oia, *ia = (void *) ifa;
829 
830 	/* stop DAD processing */
831 	nd6_dad_stop(ifa);
832 
833 	in6_ifscrub(ifp, ia);
834 
835 	if (ifp->if_flags & IFF_MULTICAST) {
836 		/*
837 		 * delete solicited multicast addr for deleting host id
838 		 */
839 		struct in6_multi *in6m;
840 		struct in6_addr llsol;
841 		bzero(&llsol, sizeof(struct in6_addr));
842 		llsol.s6_addr16[0] = htons(0xff02);
843 		llsol.s6_addr16[1] = htons(ifp->if_index);
844 		llsol.s6_addr32[1] = 0;
845 		llsol.s6_addr32[2] = htonl(1);
846 		llsol.s6_addr32[3] =
847 			ia->ia_addr.sin6_addr.s6_addr32[3];
848 		llsol.s6_addr8[12] = 0xff;
849 
850 		IN6_LOOKUP_MULTI(llsol, ifp, in6m);
851 		if (in6m)
852 			in6_delmulti(in6m);
853 	}
854 
855 	TAILQ_REMOVE(&ifp->if_addrlist, &ia->ia_ifa, ifa_list);
856 	IFAFREE(&ia->ia_ifa);
857 
858 	oia = ia;
859 	if (oia == (ia = in6_ifaddr))
860 		in6_ifaddr = ia->ia_next;
861 	else {
862 		while (ia->ia_next && (ia->ia_next != oia))
863 			ia = ia->ia_next;
864 		if (ia->ia_next)
865 			ia->ia_next = oia->ia_next;
866 		else
867 			printf("Didn't unlink in6_ifaddr from list\n");
868 	}
869 	{
870 		int iilen;
871 
872 		iilen = (sizeof(oia->ia_prefixmask.sin6_addr) << 3) -
873 			in6_mask2len(&oia->ia_prefixmask.sin6_addr);
874 		in6_prefix_remove_ifid(iilen, oia);
875 	}
876 	if (oia->ia6_multiaddrs.lh_first != NULL)
877 		in6_savemkludge(oia);
878 
879 	IFAFREE(&oia->ia_ifa);
880 }
881 
882 /*
883  * SIOC[GAD]LIFADDR.
884  *	SIOCGLIFADDR: get first address. (???)
885  *	SIOCGLIFADDR with IFLR_PREFIX:
886  *		get first address that matches the specified prefix.
887  *	SIOCALIFADDR: add the specified address.
888  *	SIOCALIFADDR with IFLR_PREFIX:
889  *		add the specified prefix, filling hostid part from
890  *		the first link-local address.  prefixlen must be <= 64.
891  *	SIOCDLIFADDR: delete the specified address.
892  *	SIOCDLIFADDR with IFLR_PREFIX:
893  *		delete the first address that matches the specified prefix.
894  * return values:
895  *	EINVAL on invalid parameters
896  *	EADDRNOTAVAIL on prefix match failed/specified address not found
897  *	other values may be returned from in6_ioctl()
898  *
899  * NOTE: SIOCALIFADDR(with IFLR_PREFIX set) allows prefixlen less than 64.
900  * this is to accomodate address naming scheme other than RFC2374,
901  * in the future.
902  * RFC2373 defines interface id to be 64bit, but it allows non-RFC2374
903  * address encoding scheme. (see figure on page 8)
904  */
905 static int
906 in6_lifaddr_ioctl(so, cmd, data, ifp, p)
907 	struct socket *so;
908 	u_long cmd;
909 	caddr_t	data;
910 	struct ifnet *ifp;
911 	struct proc *p;
912 {
913 	struct if_laddrreq *iflr = (struct if_laddrreq *)data;
914 	struct ifaddr *ifa;
915 	struct sockaddr *sa;
916 
917 	/* sanity checks */
918 	if (!data || !ifp) {
919 		panic("invalid argument to in6_lifaddr_ioctl");
920 		/*NOTRECHED*/
921 	}
922 
923 	switch (cmd) {
924 	case SIOCGLIFADDR:
925 		/* address must be specified on GET with IFLR_PREFIX */
926 		if ((iflr->flags & IFLR_PREFIX) == 0)
927 			break;
928 		/*FALLTHROUGH*/
929 	case SIOCALIFADDR:
930 	case SIOCDLIFADDR:
931 		/* address must be specified on ADD and DELETE */
932 		sa = (struct sockaddr *)&iflr->addr;
933 		if (sa->sa_family != AF_INET6)
934 			return EINVAL;
935 		if (sa->sa_len != sizeof(struct sockaddr_in6))
936 			return EINVAL;
937 		/* XXX need improvement */
938 		sa = (struct sockaddr *)&iflr->dstaddr;
939 		if (sa->sa_family && sa->sa_family != AF_INET6)
940 			return EINVAL;
941 		if (sa->sa_len && sa->sa_len != sizeof(struct sockaddr_in6))
942 			return EINVAL;
943 		break;
944 	default: /*shouldn't happen*/
945 #if 0
946 		panic("invalid cmd to in6_lifaddr_ioctl");
947 		/*NOTREACHED*/
948 #else
949 		return EOPNOTSUPP;
950 #endif
951 	}
952 	if (sizeof(struct in6_addr) * 8 < iflr->prefixlen)
953 		return EINVAL;
954 
955 	switch (cmd) {
956 	case SIOCALIFADDR:
957 	    {
958 		struct in6_aliasreq ifra;
959 		struct in6_addr *hostid = NULL;
960 		int prefixlen;
961 
962 		if ((iflr->flags & IFLR_PREFIX) != 0) {
963 			struct sockaddr_in6 *sin6;
964 
965 			/*
966 			 * hostid is to fill in the hostid part of the
967 			 * address.  hostid points to the first link-local
968 			 * address attached to the interface.
969 			 */
970 			ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp, 0);
971 			if (!ifa)
972 				return EADDRNOTAVAIL;
973 			hostid = IFA_IN6(ifa);
974 
975 		 	/* prefixlen must be <= 64. */
976 			if (64 < iflr->prefixlen)
977 				return EINVAL;
978 			prefixlen = iflr->prefixlen;
979 
980 			/* hostid part must be zero. */
981 			sin6 = (struct sockaddr_in6 *)&iflr->addr;
982 			if (sin6->sin6_addr.s6_addr32[2] != 0
983 			 || sin6->sin6_addr.s6_addr32[3] != 0) {
984 				return EINVAL;
985 			}
986 		} else
987 			prefixlen = iflr->prefixlen;
988 
989 		/* copy args to in6_aliasreq, perform ioctl(SIOCAIFADDR_IN6). */
990 		bzero(&ifra, sizeof(ifra));
991 		bcopy(iflr->iflr_name, ifra.ifra_name,
992 			sizeof(ifra.ifra_name));
993 
994 		bcopy(&iflr->addr, &ifra.ifra_addr,
995 			((struct sockaddr *)&iflr->addr)->sa_len);
996 		if (hostid) {
997 			/* fill in hostid part */
998 			ifra.ifra_addr.sin6_addr.s6_addr32[2] =
999 				hostid->s6_addr32[2];
1000 			ifra.ifra_addr.sin6_addr.s6_addr32[3] =
1001 				hostid->s6_addr32[3];
1002 		}
1003 
1004 		if (((struct sockaddr *)&iflr->dstaddr)->sa_family) {	/*XXX*/
1005 			bcopy(&iflr->dstaddr, &ifra.ifra_dstaddr,
1006 				((struct sockaddr *)&iflr->dstaddr)->sa_len);
1007 			if (hostid) {
1008 				ifra.ifra_dstaddr.sin6_addr.s6_addr32[2] =
1009 					hostid->s6_addr32[2];
1010 				ifra.ifra_dstaddr.sin6_addr.s6_addr32[3] =
1011 					hostid->s6_addr32[3];
1012 			}
1013 		}
1014 
1015 		ifra.ifra_prefixmask.sin6_family = AF_INET6;
1016 		ifra.ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6);
1017 		in6_len2mask(&ifra.ifra_prefixmask.sin6_addr, prefixlen);
1018 
1019 		ifra.ifra_flags = iflr->flags & ~IFLR_PREFIX;
1020 		return in6_control(so, SIOCAIFADDR_IN6, (caddr_t)&ifra,
1021 				   ifp, p);
1022 	    }
1023 	case SIOCGLIFADDR:
1024 	case SIOCDLIFADDR:
1025 	    {
1026 		struct in6_ifaddr *ia;
1027 		struct in6_addr mask, candidate, match;
1028 		struct sockaddr_in6 *sin6;
1029 		int cmp;
1030 
1031 		bzero(&mask, sizeof(mask));
1032 		if (iflr->flags & IFLR_PREFIX) {
1033 			/* lookup a prefix rather than address. */
1034 			in6_len2mask(&mask, iflr->prefixlen);
1035 
1036 			sin6 = (struct sockaddr_in6 *)&iflr->addr;
1037 			bcopy(&sin6->sin6_addr, &match, sizeof(match));
1038 			match.s6_addr32[0] &= mask.s6_addr32[0];
1039 			match.s6_addr32[1] &= mask.s6_addr32[1];
1040 			match.s6_addr32[2] &= mask.s6_addr32[2];
1041 			match.s6_addr32[3] &= mask.s6_addr32[3];
1042 
1043 			/* if you set extra bits, that's wrong */
1044 			if (bcmp(&match, &sin6->sin6_addr, sizeof(match)))
1045 				return EINVAL;
1046 
1047 			cmp = 1;
1048 		} else {
1049 			if (cmd == SIOCGLIFADDR) {
1050 				/* on getting an address, take the 1st match */
1051 				cmp = 0;	/*XXX*/
1052 			} else {
1053 				/* on deleting an address, do exact match */
1054 				in6_len2mask(&mask, 128);
1055 				sin6 = (struct sockaddr_in6 *)&iflr->addr;
1056 				bcopy(&sin6->sin6_addr, &match, sizeof(match));
1057 
1058 				cmp = 1;
1059 			}
1060 		}
1061 
1062 		for (ifa = ifp->if_addrlist.tqh_first;
1063 		     ifa;
1064 		     ifa = ifa->ifa_list.tqe_next)
1065 		{
1066 			if (ifa->ifa_addr->sa_family != AF_INET6)
1067 				continue;
1068 			if (!cmp)
1069 				break;
1070 			bcopy(IFA_IN6(ifa), &candidate, sizeof(candidate));
1071 			candidate.s6_addr32[0] &= mask.s6_addr32[0];
1072 			candidate.s6_addr32[1] &= mask.s6_addr32[1];
1073 			candidate.s6_addr32[2] &= mask.s6_addr32[2];
1074 			candidate.s6_addr32[3] &= mask.s6_addr32[3];
1075 			if (IN6_ARE_ADDR_EQUAL(&candidate, &match))
1076 				break;
1077 		}
1078 		if (!ifa)
1079 			return EADDRNOTAVAIL;
1080 		ia = ifa2ia6(ifa);
1081 
1082 		if (cmd == SIOCGLIFADDR) {
1083 			/* fill in the if_laddrreq structure */
1084 			bcopy(&ia->ia_addr, &iflr->addr, ia->ia_addr.sin6_len);
1085 
1086 			if ((ifp->if_flags & IFF_POINTOPOINT) != 0) {
1087 				bcopy(&ia->ia_dstaddr, &iflr->dstaddr,
1088 					ia->ia_dstaddr.sin6_len);
1089 			} else
1090 				bzero(&iflr->dstaddr, sizeof(iflr->dstaddr));
1091 
1092 			iflr->prefixlen =
1093 				in6_mask2len(&ia->ia_prefixmask.sin6_addr);
1094 
1095 			iflr->flags = ia->ia6_flags;	/*XXX*/
1096 
1097 			return 0;
1098 		} else {
1099 			struct in6_aliasreq ifra;
1100 
1101 			/* fill in6_aliasreq and do ioctl(SIOCDIFADDR_IN6) */
1102 			bzero(&ifra, sizeof(ifra));
1103 			bcopy(iflr->iflr_name, ifra.ifra_name,
1104 				sizeof(ifra.ifra_name));
1105 
1106 			bcopy(&ia->ia_addr, &ifra.ifra_addr,
1107 				ia->ia_addr.sin6_len);
1108 			if ((ifp->if_flags & IFF_POINTOPOINT) != 0) {
1109 				bcopy(&ia->ia_dstaddr, &ifra.ifra_dstaddr,
1110 					ia->ia_dstaddr.sin6_len);
1111 			} else {
1112 				bzero(&ifra.ifra_dstaddr,
1113 				    sizeof(ifra.ifra_dstaddr));
1114 			}
1115 			bcopy(&ia->ia_prefixmask, &ifra.ifra_dstaddr,
1116 				ia->ia_prefixmask.sin6_len);
1117 
1118 			ifra.ifra_flags = ia->ia6_flags;
1119 
1120 			return in6_control(so, SIOCDIFADDR_IN6, (caddr_t)&ifra,
1121 				ifp, p);
1122 		}
1123 	    }
1124 	}
1125 
1126 	return EOPNOTSUPP;	/*just for safety*/
1127 }
1128 
1129 /*
1130  * Delete any existing route for an interface.
1131  */
1132 void
1133 in6_ifscrub(ifp, ia)
1134 	struct ifnet *ifp;
1135 	struct in6_ifaddr *ia;
1136 {
1137 	if ((ia->ia_flags & IFA_ROUTE) == 0)
1138 		return;
1139 	/*
1140 	 * We should check the existence of dstaddr, because link-local
1141 	 * addresses can be configured without particular destinations
1142 	 * even on point-to-point or loopback interfaces.
1143 	 * In this case, kernel would panic in rtinit()...
1144 	 */
1145 	if (ifp->if_flags & (IFF_LOOPBACK | IFF_POINTOPOINT) &&
1146 	    (ia->ia_ifa.ifa_dstaddr != NULL))
1147 		rtinit(&(ia->ia_ifa), (int)RTM_DELETE, RTF_HOST);
1148 	else
1149 		rtinit(&(ia->ia_ifa), (int)RTM_DELETE, 0);
1150 	ia->ia_flags &= ~IFA_ROUTE;
1151 
1152 	/* Remove ownaddr's loopback rtentry, if it exists. */
1153 	in6_ifremloop(&(ia->ia_ifa));
1154 }
1155 
1156 /*
1157  * Initialize an interface's intetnet6 address
1158  * and routing table entry.
1159  */
1160 int
1161 in6_ifinit(ifp, ia, sin6, scrub)
1162 	struct ifnet *ifp;
1163 	struct in6_ifaddr *ia;
1164 	struct sockaddr_in6 *sin6;
1165 	int scrub;
1166 {
1167 	struct	sockaddr_in6 oldaddr;
1168 	int	error, flags = RTF_UP;
1169 	int	s = splimp();
1170 
1171 	oldaddr = ia->ia_addr;
1172 	ia->ia_addr = *sin6;
1173 	/*
1174 	 * Give the interface a chance to initialize
1175 	 * if this is its first address,
1176 	 * and to validate the address if necessary.
1177 	 */
1178 	if (ifp->if_ioctl &&
1179 	   (error = (*ifp->if_ioctl)(ifp, SIOCSIFADDR, (caddr_t)ia))) {
1180 		splx(s);
1181 		ia->ia_addr = oldaddr;
1182 		return(error);
1183 	}
1184 
1185 	switch (ifp->if_type) {
1186 	case IFT_ARCNET:
1187 	case IFT_ETHER:
1188 	case IFT_FDDI:
1189 		ia->ia_ifa.ifa_rtrequest = nd6_rtrequest;
1190 		ia->ia_ifa.ifa_flags |= RTF_CLONING;
1191 		break;
1192 	case IFT_PPP:
1193 		ia->ia_ifa.ifa_rtrequest = nd6_p2p_rtrequest;
1194 		ia->ia_ifa.ifa_flags |= RTF_CLONING;
1195 		break;
1196 	}
1197 
1198 	splx(s);
1199 	if (scrub) {
1200 		ia->ia_ifa.ifa_addr = (struct sockaddr *)&oldaddr;
1201 		in6_ifscrub(ifp, ia);
1202 		ia->ia_ifa.ifa_addr = (struct sockaddr *)&ia->ia_addr;
1203 	}
1204 	/* xxx
1205 	 * in_socktrim
1206 	 */
1207 	/*
1208 	 * Add route for the network.
1209 	 */
1210 	ia->ia_ifa.ifa_metric = ifp->if_metric;
1211 	if (ifp->if_flags & IFF_LOOPBACK) {
1212 		ia->ia_ifa.ifa_dstaddr = ia->ia_ifa.ifa_addr;
1213 		flags |= RTF_HOST;
1214 	} else if (ifp->if_flags & IFF_POINTOPOINT) {
1215 		if (ia->ia_dstaddr.sin6_family != AF_INET6)
1216 			return(0);
1217 		flags |= RTF_HOST;
1218 	}
1219 	if ((error = rtinit(&(ia->ia_ifa), (int)RTM_ADD, flags)) == 0)
1220 		ia->ia_flags |= IFA_ROUTE;
1221 
1222 	/* Add ownaddr as loopback rtentry, if necessary(ex. on p2p link). */
1223 	in6_ifaddloop(&(ia->ia_ifa));
1224 
1225 	if (ifp->if_flags & IFF_MULTICAST)
1226 		in6_restoremkludge(ia, ifp);
1227 
1228 	return(error);
1229 }
1230 
1231 /*
1232  * Multicast address kludge:
1233  * If there were any multicast addresses attached to this interface address,
1234  * either move them to another address on this interface, or save them until
1235  * such time as this interface is reconfigured for IPv6.
1236  */
1237 void
1238 in6_savemkludge(oia)
1239 	struct in6_ifaddr *oia;
1240 {
1241 	struct in6_ifaddr *ia;
1242 	struct in6_multi *in6m, *next;
1243 
1244 	IFP_TO_IA6(oia->ia_ifp, ia);
1245 	if (ia) {	/* there is another address */
1246 		for (in6m = oia->ia6_multiaddrs.lh_first; in6m; in6m = next){
1247 			next = in6m->in6m_entry.le_next;
1248 			IFAFREE(&in6m->in6m_ia->ia_ifa);
1249 			ia->ia_ifa.ifa_refcnt++;
1250 			in6m->in6m_ia = ia;
1251 			LIST_INSERT_HEAD(&ia->ia6_multiaddrs, in6m, in6m_entry);
1252 		}
1253 	} else {	/* last address on this if deleted, save */
1254 		struct multi6_kludge *mk;
1255 
1256 		for (mk = in6_mk.lh_first; mk; mk = mk->mk_entry.le_next) {
1257 			if (mk->mk_ifp == oia->ia_ifp)
1258 				break;
1259 		}
1260 		if (mk == NULL) /* this should not happen! */
1261 			panic("in6_savemkludge: no kludge space");
1262 
1263 		for (in6m = oia->ia6_multiaddrs.lh_first; in6m; in6m = next){
1264 			next = in6m->in6m_entry.le_next;
1265 			IFAFREE(&in6m->in6m_ia->ia_ifa); /* release reference */
1266 			in6m->in6m_ia = NULL;
1267 			LIST_INSERT_HEAD(&mk->mk_head, in6m, in6m_entry);
1268 		}
1269 	}
1270 }
1271 
1272 /*
1273  * Continuation of multicast address hack:
1274  * If there was a multicast group list previously saved for this interface,
1275  * then we re-attach it to the first address configured on the i/f.
1276  */
1277 void
1278 in6_restoremkludge(ia, ifp)
1279 	struct in6_ifaddr *ia;
1280 	struct ifnet *ifp;
1281 {
1282 	struct multi6_kludge *mk;
1283 
1284 	for (mk = in6_mk.lh_first; mk; mk = mk->mk_entry.le_next) {
1285 		if (mk->mk_ifp == ifp) {
1286 			struct in6_multi *in6m, *next;
1287 
1288 			for (in6m = mk->mk_head.lh_first; in6m; in6m = next) {
1289 				next = in6m->in6m_entry.le_next;
1290 				in6m->in6m_ia = ia;
1291 				ia->ia_ifa.ifa_refcnt++;
1292 				LIST_INSERT_HEAD(&ia->ia6_multiaddrs,
1293 						 in6m, in6m_entry);
1294 			}
1295 			LIST_INIT(&mk->mk_head);
1296 			break;
1297 		}
1298 	}
1299 }
1300 
1301 /*
1302  * Allocate space for the kludge at interface initialization time.
1303  * Formerly, we dynamically allocated the space in in6_savemkludge() with
1304  * malloc(M_WAITOK).  However, it was wrong since the function could be called
1305  * under an interrupt context (software timer on address lifetime expiration).
1306  * Also, we cannot just give up allocating the strucutre, since the group
1307  * membership structure is very complex and we need to keep it anyway.
1308  * Of course, this function MUST NOT be called under an interrupt context.
1309  * Specifically, it is expected to be called only from in6_ifattach(), though
1310  * it is a global function.
1311  */
1312 void
1313 in6_createmkludge(ifp)
1314 	struct ifnet *ifp;
1315 {
1316 	struct multi6_kludge *mk;
1317 
1318 	for (mk = in6_mk.lh_first; mk; mk = mk->mk_entry.le_next) {
1319 		/* If we've already had one, do not allocate. */
1320 		if (mk->mk_ifp == ifp)
1321 			return;
1322 	}
1323 
1324 	mk = malloc(sizeof(*mk), M_IPMADDR, M_WAITOK);
1325 
1326 	bzero(mk, sizeof(*mk));
1327 	LIST_INIT(&mk->mk_head);
1328 	mk->mk_ifp = ifp;
1329 	LIST_INSERT_HEAD(&in6_mk, mk, mk_entry);
1330 }
1331 
1332 void
1333 in6_purgemkludge(ifp)
1334 	struct ifnet *ifp;
1335 {
1336 	struct multi6_kludge *mk;
1337 	struct in6_multi *in6m;
1338 
1339 	for (mk = in6_mk.lh_first; mk; mk = mk->mk_entry.le_next) {
1340 		if (mk->mk_ifp != ifp)
1341 			continue;
1342 
1343 		/* leave from all multicast groups joined */
1344 		while ((in6m = LIST_FIRST(&mk->mk_head)) != NULL)
1345 			in6_delmulti(in6m);
1346 		LIST_REMOVE(mk, mk_entry);
1347 		free(mk, M_IPMADDR);
1348 		break;
1349 	}
1350 }
1351 
1352 /*
1353  * Add an address to the list of IP6 multicast addresses for a
1354  * given interface.
1355  */
1356 struct	in6_multi *
1357 in6_addmulti(maddr6, ifp, errorp)
1358 	struct in6_addr *maddr6;
1359 	struct ifnet *ifp;
1360 	int *errorp;
1361 {
1362 	struct	in6_ifaddr *ia;
1363 	struct	in6_ifreq ifr;
1364 	struct	in6_multi *in6m;
1365 	int	s = splnet();
1366 
1367 	*errorp = 0;
1368 	/*
1369 	 * See if address already in list.
1370 	 */
1371 	IN6_LOOKUP_MULTI(*maddr6, ifp, in6m);
1372 	if (in6m != NULL) {
1373 		/*
1374 		 * Found it; just increment the refrence count.
1375 		 */
1376 		in6m->in6m_refcount++;
1377 	} else {
1378 		/*
1379 		 * New address; allocate a new multicast record
1380 		 * and link it into the interface's multicast list.
1381 		 */
1382 		in6m = (struct in6_multi *)
1383 			malloc(sizeof(*in6m), M_IPMADDR, M_NOWAIT);
1384 		if (in6m == NULL) {
1385 			splx(s);
1386 			*errorp = ENOBUFS;
1387 			return(NULL);
1388 		}
1389 		in6m->in6m_addr = *maddr6;
1390 		in6m->in6m_ifp = ifp;
1391 		in6m->in6m_refcount = 1;
1392 		IFP_TO_IA6(ifp, ia);
1393 		if (ia == NULL) {
1394 			free(in6m, M_IPMADDR);
1395 			splx(s);
1396 			*errorp = EADDRNOTAVAIL; /* appropriate? */
1397 			return(NULL);
1398 		}
1399 		in6m->in6m_ia = ia;
1400 		ia->ia_ifa.ifa_refcnt++; /* gain a reference */
1401 		LIST_INSERT_HEAD(&ia->ia6_multiaddrs, in6m, in6m_entry);
1402 
1403 		/*
1404 		 * Ask the network driver to update its multicast reception
1405 		 * filter appropriately for the new address.
1406 		 */
1407 		bzero(&ifr.ifr_addr, sizeof(struct sockaddr_in6));
1408 		ifr.ifr_addr.sin6_len = sizeof(struct sockaddr_in6);
1409 		ifr.ifr_addr.sin6_family = AF_INET6;
1410 		ifr.ifr_addr.sin6_addr = *maddr6;
1411 		if (ifp->if_ioctl == NULL)
1412 			*errorp = ENXIO; /* XXX: appropriate? */
1413 		else
1414 			*errorp = (*ifp->if_ioctl)(ifp, SIOCADDMULTI,
1415 						    (caddr_t)&ifr);
1416 		if (*errorp) {
1417 			LIST_REMOVE(in6m, in6m_entry);
1418 			free(in6m, M_IPMADDR);
1419 			IFAFREE(&ia->ia_ifa);
1420 			splx(s);
1421 			return(NULL);
1422 		}
1423 		/*
1424 		 * Let MLD6 know that we have joined a new IP6 multicast
1425 		 * group.
1426 		 */
1427 		mld6_start_listening(in6m);
1428 	}
1429 	splx(s);
1430 	return(in6m);
1431 }
1432 
1433 /*
1434  * Delete a multicast address record.
1435  */
1436 void
1437 in6_delmulti(in6m)
1438 	struct in6_multi *in6m;
1439 {
1440 	struct	in6_ifreq ifr;
1441 	int	s = splnet();
1442 
1443 	if (--in6m->in6m_refcount == 0) {
1444 		/*
1445 		 * No remaining claims to this record; let MLD6 know
1446 		 * that we are leaving the multicast group.
1447 		 */
1448 		mld6_stop_listening(in6m);
1449 
1450 		/*
1451 		 * Unlink from list.
1452 		 */
1453 		LIST_REMOVE(in6m, in6m_entry);
1454 		if (in6m->in6m_ia) {
1455 			IFAFREE(&in6m->in6m_ia->ia_ifa); /* release reference */
1456 		}
1457 
1458 		/*
1459 		 * Notify the network driver to update its multicast
1460 		 * reception filter.
1461 		 */
1462 		bzero(&ifr.ifr_addr, sizeof(struct sockaddr_in6));
1463 		ifr.ifr_addr.sin6_len = sizeof(struct sockaddr_in6);
1464 		ifr.ifr_addr.sin6_family = AF_INET6;
1465 		ifr.ifr_addr.sin6_addr = in6m->in6m_addr;
1466 		(*in6m->in6m_ifp->if_ioctl)(in6m->in6m_ifp,
1467 					    SIOCDELMULTI, (caddr_t)&ifr);
1468 		free(in6m, M_IPMADDR);
1469 	}
1470 	splx(s);
1471 }
1472 
1473 /*
1474  * Find an IPv6 interface link-local address specific to an interface.
1475  */
1476 struct in6_ifaddr *
1477 in6ifa_ifpforlinklocal(ifp, ignoreflags)
1478 	struct ifnet *ifp;
1479 	int ignoreflags;
1480 {
1481 	struct ifaddr *ifa;
1482 
1483 	for (ifa = ifp->if_addrlist.tqh_first;
1484 	     ifa;
1485 	     ifa = ifa->ifa_list.tqe_next)
1486 	{
1487 		if (ifa->ifa_addr == NULL)
1488 			continue;	/* just for safety */
1489 		if (ifa->ifa_addr->sa_family != AF_INET6)
1490 			continue;
1491 		if (IN6_IS_ADDR_LINKLOCAL(IFA_IN6(ifa))) {
1492 			if ((((struct in6_ifaddr *)ifa)->ia6_flags &
1493 			     ignoreflags) != 0)
1494 				continue;
1495 			break;
1496 		}
1497 	}
1498 
1499 	return((struct in6_ifaddr *)ifa);
1500 }
1501 
1502 
1503 /*
1504  * find the internet address corresponding to a given interface and address.
1505  */
1506 struct in6_ifaddr *
1507 in6ifa_ifpwithaddr(ifp, addr)
1508 	struct ifnet *ifp;
1509 	struct in6_addr *addr;
1510 {
1511 	struct ifaddr *ifa;
1512 
1513 	for (ifa = ifp->if_addrlist.tqh_first;
1514 	     ifa;
1515 	     ifa = ifa->ifa_list.tqe_next)
1516 	{
1517 		if (ifa->ifa_addr == NULL)
1518 			continue;	/* just for safety */
1519 		if (ifa->ifa_addr->sa_family != AF_INET6)
1520 			continue;
1521 		if (IN6_ARE_ADDR_EQUAL(addr, IFA_IN6(ifa)))
1522 			break;
1523 	}
1524 
1525 	return((struct in6_ifaddr *)ifa);
1526 }
1527 
1528 /*
1529  * Convert IP6 address to printable (loggable) representation.
1530  */
1531 static char digits[] = "0123456789abcdef";
1532 static int ip6round = 0;
1533 char *
1534 ip6_sprintf(addr)
1535 	struct in6_addr *addr;
1536 {
1537 	static char ip6buf[8][48];
1538 	int i;
1539 	char *cp;
1540 	u_short *a = (u_short *)addr;
1541 	u_char *d;
1542 	int dcolon = 0;
1543 
1544 	ip6round = (ip6round + 1) & 7;
1545 	cp = ip6buf[ip6round];
1546 
1547 	for (i = 0; i < 8; i++) {
1548 		if (dcolon == 1) {
1549 			if (*a == 0) {
1550 				if (i == 7)
1551 					*cp++ = ':';
1552 				a++;
1553 				continue;
1554 			} else
1555 				dcolon = 2;
1556 		}
1557 		if (*a == 0) {
1558 			if (dcolon == 0 && *(a + 1) == 0) {
1559 				if (i == 0)
1560 					*cp++ = ':';
1561 				*cp++ = ':';
1562 				dcolon = 1;
1563 			} else {
1564 				*cp++ = '0';
1565 				*cp++ = ':';
1566 			}
1567 			a++;
1568 			continue;
1569 		}
1570 		d = (u_char *)a;
1571 		*cp++ = digits[*d >> 4];
1572 		*cp++ = digits[*d++ & 0xf];
1573 		*cp++ = digits[*d >> 4];
1574 		*cp++ = digits[*d & 0xf];
1575 		*cp++ = ':';
1576 		a++;
1577 	}
1578 	*--cp = 0;
1579 	return(ip6buf[ip6round]);
1580 }
1581 
1582 int
1583 in6_localaddr(in6)
1584 	struct in6_addr *in6;
1585 {
1586 	struct in6_ifaddr *ia;
1587 
1588 	if (IN6_IS_ADDR_LOOPBACK(in6) || IN6_IS_ADDR_LINKLOCAL(in6))
1589 		return 1;
1590 
1591 	for (ia = in6_ifaddr; ia; ia = ia->ia_next)
1592 		if (IN6_ARE_MASKED_ADDR_EQUAL(in6, &ia->ia_addr.sin6_addr,
1593 					      &ia->ia_prefixmask.sin6_addr))
1594 			return 1;
1595 
1596 	return (0);
1597 }
1598 
1599 /*
1600  * Get a scope of the address. Node-local, link-local, site-local or global.
1601  */
1602 int
1603 in6_addrscope (addr)
1604 struct in6_addr *addr;
1605 {
1606 	int scope;
1607 
1608 	if (addr->s6_addr8[0] == 0xfe) {
1609 		scope = addr->s6_addr8[1] & 0xc0;
1610 
1611 		switch (scope) {
1612 		case 0x80:
1613 			return IPV6_ADDR_SCOPE_LINKLOCAL;
1614 			break;
1615 		case 0xc0:
1616 			return IPV6_ADDR_SCOPE_SITELOCAL;
1617 			break;
1618 		default:
1619 			return IPV6_ADDR_SCOPE_GLOBAL; /* just in case */
1620 			break;
1621 		}
1622 	}
1623 
1624 
1625 	if (addr->s6_addr8[0] == 0xff) {
1626 		scope = addr->s6_addr8[1] & 0x0f;
1627 
1628 		/*
1629 		 * due to other scope such as reserved,
1630 		 * return scope doesn't work.
1631 		 */
1632 		switch (scope) {
1633 		case IPV6_ADDR_SCOPE_NODELOCAL:
1634 			return IPV6_ADDR_SCOPE_NODELOCAL;
1635 			break;
1636 		case IPV6_ADDR_SCOPE_LINKLOCAL:
1637 			return IPV6_ADDR_SCOPE_LINKLOCAL;
1638 			break;
1639 		case IPV6_ADDR_SCOPE_SITELOCAL:
1640 			return IPV6_ADDR_SCOPE_SITELOCAL;
1641 			break;
1642 		default:
1643 			return IPV6_ADDR_SCOPE_GLOBAL;
1644 			break;
1645 		}
1646 	}
1647 
1648 	if (bcmp(&in6addr_loopback, addr, sizeof(addr) - 1) == 0) {
1649 		if (addr->s6_addr8[15] == 1) /* loopback */
1650 			return IPV6_ADDR_SCOPE_NODELOCAL;
1651 		if (addr->s6_addr8[15] == 0) /* unspecified */
1652 			return IPV6_ADDR_SCOPE_LINKLOCAL;
1653 	}
1654 
1655 	return IPV6_ADDR_SCOPE_GLOBAL;
1656 }
1657 
1658 int
1659 in6_addr2scopeid(ifp, addr)
1660 	struct ifnet *ifp;	/* must not be NULL */
1661 	struct in6_addr *addr;	/* must not be NULL */
1662 {
1663 	int scope = in6_addrscope(addr);
1664 
1665 	switch(scope) {
1666 	case IPV6_ADDR_SCOPE_NODELOCAL:
1667 		return(-1);	/* XXX: is this an appropriate value? */
1668 
1669 	case IPV6_ADDR_SCOPE_LINKLOCAL:
1670 		/* XXX: we do not distinguish between a link and an I/F. */
1671 		return(ifp->if_index);
1672 
1673 	case IPV6_ADDR_SCOPE_SITELOCAL:
1674 		return(0);	/* XXX: invalid. */
1675 
1676 	default:
1677 		return(0);	/* XXX: treat as global. */
1678 	}
1679 }
1680 
1681 /*
1682  * return length of part which dst and src are equal
1683  * hard coding...
1684  */
1685 
1686 int
1687 in6_matchlen(src, dst)
1688 struct in6_addr *src, *dst;
1689 {
1690 	int match = 0;
1691 	u_char *s = (u_char *)src, *d = (u_char *)dst;
1692 	u_char *lim = s + 16, r;
1693 
1694 	while (s < lim)
1695 		if ((r = (*d++ ^ *s++)) != 0) {
1696 			while (r < 128) {
1697 				match++;
1698 				r <<= 1;
1699 			}
1700 			break;
1701 		} else
1702 			match += 8;
1703 	return match;
1704 }
1705 
1706 int
1707 in6_are_prefix_equal(p1, p2, len)
1708 	struct in6_addr *p1, *p2;
1709 	int len;
1710 {
1711 	int bytelen, bitlen;
1712 
1713 	/* sanity check */
1714 	if (0 > len || len > 128) {
1715 		log(LOG_ERR, "in6_are_prefix_equal: invalid prefix length(%d)\n",
1716 		    len);
1717 		return(0);
1718 	}
1719 
1720 	bytelen = len / 8;
1721 	bitlen = len % 8;
1722 
1723 	if (bcmp(&p1->s6_addr, &p2->s6_addr, bytelen))
1724 		return(0);
1725 	if (p1->s6_addr[bytelen] >> (8 - bitlen) !=
1726 	    p2->s6_addr[bytelen] >> (8 - bitlen))
1727 		return(0);
1728 
1729 	return(1);
1730 }
1731 
1732 void
1733 in6_prefixlen2mask(maskp, len)
1734 	struct in6_addr *maskp;
1735 	int len;
1736 {
1737 	u_char maskarray[8] = {0x80, 0xc0, 0xe0, 0xf0, 0xf8, 0xfc, 0xfe, 0xff};
1738 	int bytelen, bitlen, i;
1739 
1740 	/* sanity check */
1741 	if (0 > len || len > 128) {
1742 		log(LOG_ERR, "in6_prefixlen2mask: invalid prefix length(%d)\n",
1743 		    len);
1744 		return;
1745 	}
1746 
1747 	bzero(maskp, sizeof(*maskp));
1748 	bytelen = len / 8;
1749 	bitlen = len % 8;
1750 	for (i = 0; i < bytelen; i++)
1751 		maskp->s6_addr[i] = 0xff;
1752 	if (bitlen)
1753 		maskp->s6_addr[bytelen] = maskarray[bitlen - 1];
1754 }
1755 
1756 /*
1757  * return the best address out of the same scope
1758  */
1759 struct in6_ifaddr *
1760 in6_ifawithscope(oifp, dst)
1761 	struct ifnet *oifp;
1762 	struct in6_addr *dst;
1763 {
1764 	int dst_scope =	in6_addrscope(dst), src_scope, best_scope = 0;
1765 	int blen = -1;
1766 	struct ifaddr *ifa;
1767 	struct ifnet *ifp;
1768 	struct in6_ifaddr *ifa_best = NULL;
1769 
1770 	if (oifp == NULL) {
1771 		printf("in6_ifawithscope: output interface is not specified\n");
1772 		return(NULL);
1773 	}
1774 
1775 	/*
1776 	 * We search for all addresses on all interfaces from the beginning.
1777 	 * Comparing an interface with the outgoing interface will be done
1778 	 * only at the final stage of tiebreaking.
1779 	 */
1780 	for (ifp = TAILQ_FIRST(&ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list))
1781 	{
1782 		/*
1783 		 * We can never take an address that breaks the scope zone
1784 		 * of the destination.
1785 		 */
1786 		if (in6_addr2scopeid(ifp, dst) != in6_addr2scopeid(oifp, dst))
1787 			continue;
1788 
1789 		for (ifa = ifp->if_addrlist.tqh_first; ifa;
1790 		     ifa = ifa->ifa_list.tqe_next)
1791 		{
1792 			int tlen = -1, dscopecmp, bscopecmp, matchcmp;
1793 
1794 			if (ifa->ifa_addr->sa_family != AF_INET6)
1795 				continue;
1796 
1797 			src_scope = in6_addrscope(IFA_IN6(ifa));
1798 
1799 #ifdef ADDRSELECT_DEBUG		/* should be removed after stabilization */
1800 			dscopecmp = IN6_ARE_SCOPE_CMP(src_scope, dst_scope);
1801 			printf("in6_ifawithscope: dst=%s bestaddr=%s, "
1802 			       "newaddr=%s, scope=%x, dcmp=%d, bcmp=%d, "
1803 			       "matchlen=%d, flgs=%x\n",
1804 			       ip6_sprintf(dst),
1805 			       ifa_best ? ip6_sprintf(&ifa_best->ia_addr.sin6_addr) : "none",
1806 			       ip6_sprintf(IFA_IN6(ifa)), src_scope,
1807 			       dscopecmp,
1808 			       ifa_best ? IN6_ARE_SCOPE_CMP(src_scope, best_scope) : -1,
1809 			       in6_matchlen(IFA_IN6(ifa), dst),
1810 			       ((struct in6_ifaddr *)ifa)->ia6_flags);
1811 #endif
1812 
1813 			/*
1814 			 * Don't use an address before completing DAD
1815 			 * nor a duplicated address.
1816 			 */
1817 			if (((struct in6_ifaddr *)ifa)->ia6_flags &
1818 			    IN6_IFF_NOTREADY)
1819 				continue;
1820 
1821 			/* XXX: is there any case to allow anycasts? */
1822 			if (((struct in6_ifaddr *)ifa)->ia6_flags &
1823 			    IN6_IFF_ANYCAST)
1824 				continue;
1825 
1826 			if (((struct in6_ifaddr *)ifa)->ia6_flags &
1827 			    IN6_IFF_DETACHED)
1828 				continue;
1829 
1830 			/*
1831 			 * If this is the first address we find,
1832 			 * keep it anyway.
1833 			 */
1834 			if (ifa_best == NULL)
1835 				goto replace;
1836 
1837 			/*
1838 			 * ifa_best is never NULL beyond this line except
1839 			 * within the block labeled "replace".
1840 			 */
1841 
1842 			/*
1843 			 * If ifa_best has a smaller scope than dst and
1844 			 * the current address has a larger one than
1845 			 * (or equal to) dst, always replace ifa_best.
1846 			 * Also, if the current address has a smaller scope
1847 			 * than dst, ignore it unless ifa_best also has a
1848 			 * smaller scope.
1849 			 */
1850 			if (IN6_ARE_SCOPE_CMP(best_scope, dst_scope) < 0 &&
1851 			    IN6_ARE_SCOPE_CMP(src_scope, dst_scope) >= 0)
1852 				goto replace;
1853 			if (IN6_ARE_SCOPE_CMP(src_scope, dst_scope) < 0 &&
1854 			    IN6_ARE_SCOPE_CMP(best_scope, dst_scope) >= 0)
1855 				continue;
1856 
1857 			/*
1858 			 * A deprecated address SHOULD NOT be used in new
1859 			 * communications if an alternate (non-deprecated)
1860 			 * address is available and has sufficient scope.
1861 			 * RFC 2462, Section 5.5.4.
1862 			 */
1863 			if (((struct in6_ifaddr *)ifa)->ia6_flags &
1864 			    IN6_IFF_DEPRECATED) {
1865 				/*
1866 				 * Ignore any deprecated addresses if
1867 				 * specified by configuration.
1868 				 */
1869 				if (!ip6_use_deprecated)
1870 					continue;
1871 
1872 				/*
1873 				 * If we have already found a non-deprecated
1874 				 * candidate, just ignore deprecated addresses.
1875 				 */
1876 				if ((ifa_best->ia6_flags & IN6_IFF_DEPRECATED)
1877 				    == 0)
1878 					continue;
1879 			}
1880 
1881 			/*
1882 			 * A non-deprecated address is always preferred
1883 			 * to a deprecated one regardless of scopes and
1884 			 * address matching.
1885 			 */
1886 			if ((ifa_best->ia6_flags & IN6_IFF_DEPRECATED) &&
1887 			    (((struct in6_ifaddr *)ifa)->ia6_flags &
1888 			     IN6_IFF_DEPRECATED) == 0)
1889 				goto replace;
1890 
1891 			/*
1892 			 * At this point, we have two cases:
1893 			 * 1. we are looking at a non-deprecated address,
1894 			 *    and ifa_best is also non-deprecated.
1895 			 * 2. we are looking at a deprecated address,
1896 			 *    and ifa_best is also deprecated.
1897 			 * Also, we do not have to consider a case where
1898 			 * the scope of if_best is larger(smaller) than dst and
1899 			 * the scope of the current address is smaller(larger)
1900 			 * than dst. Such a case has already been covered.
1901 			 * Tiebreaking is done according to the following
1902 			 * items:
1903 			 * - the scope comparison between the address and
1904 			 *   dst (dscopecmp)
1905 			 * - the scope comparison between the address and
1906 			 *   ifa_best (bscopecmp)
1907 			 * - if the address match dst longer than ifa_best
1908 			 *   (matchcmp)
1909 			 * - if the address is on the outgoing I/F (outI/F)
1910 			 *
1911 			 * Roughly speaking, the selection policy is
1912 			 * - the most important item is scope. The same scope
1913 			 *   is best. Then search for a larger scope.
1914 			 *   Smaller scopes are the last resort.
1915 			 * - A deprecated address is chosen only when we have
1916 			 *   no address that has an enough scope, but is
1917 			 *   prefered to any addresses of smaller scopes.
1918 			 * - Longest address match against dst is considered
1919 			 *   only for addresses that has the same scope of dst.
1920 			 * - If there is no other reasons to choose one,
1921 			 *   addresses on the outgoing I/F are preferred.
1922 			 *
1923 			 * The precise decision table is as follows:
1924 			 * dscopecmp bscopecmp matchcmp outI/F | replace?
1925 			 *    !equal     equal      N/A    Yes |      Yes (1)
1926 			 *    !equal     equal      N/A     No |       No (2)
1927 			 *    larger    larger      N/A    N/A |       No (3)
1928 			 *    larger   smaller      N/A    N/A |      Yes (4)
1929 			 *   smaller    larger      N/A    N/A |      Yes (5)
1930 			 *   smaller   smaller      N/A    N/A |       No (6)
1931 			 *     equal   smaller      N/A    N/A |      Yes (7)
1932 			 *     equal    larger       (already done)
1933 			 *     equal     equal   larger    N/A |      Yes (8)
1934 			 *     equal     equal  smaller    N/A |       No (9)
1935 			 *     equal     equal    equal    Yes |      Yes (a)
1936 			 *     eaual     eqaul    equal     No |       No (b)
1937 			 */
1938 			dscopecmp = IN6_ARE_SCOPE_CMP(src_scope, dst_scope);
1939 			bscopecmp = IN6_ARE_SCOPE_CMP(src_scope, best_scope);
1940 
1941 			if (dscopecmp && bscopecmp == 0) {
1942 				if (oifp == ifp) /* (1) */
1943 					goto replace;
1944 				continue; /* (2) */
1945 			}
1946 			if (dscopecmp > 0) {
1947 				if (bscopecmp > 0) /* (3) */
1948 					continue;
1949 				goto replace; /* (4) */
1950 			}
1951 			if (dscopecmp < 0) {
1952 				if (bscopecmp > 0) /* (5) */
1953 					goto replace;
1954 				continue; /* (6) */
1955 			}
1956 
1957 			/* now dscopecmp must be 0 */
1958 			if (bscopecmp < 0)
1959 				goto replace; /* (7) */
1960 
1961 			/*
1962 			 * At last both dscopecmp and bscopecmp must be 0.
1963 			 * We need address matching against dst for
1964 			 * tiebreaking.
1965 			 */
1966 			tlen = in6_matchlen(IFA_IN6(ifa), dst);
1967 			matchcmp = tlen - blen;
1968 			if (matchcmp > 0) /* (8) */
1969 				goto replace;
1970 			if (matchcmp < 0) /* (9) */
1971 				continue;
1972 			if (oifp == ifp) /* (a) */
1973 				goto replace;
1974 			continue; /* (b) */
1975 
1976 		  replace:
1977 			ifa_best = (struct in6_ifaddr *)ifa;
1978 			blen = tlen >= 0 ? tlen :
1979 				in6_matchlen(IFA_IN6(ifa), dst);
1980 			best_scope = in6_addrscope(&ifa_best->ia_addr.sin6_addr);
1981 		}
1982 	}
1983 
1984 	/* count statistics for future improvements */
1985 	if (ifa_best == NULL)
1986 		ip6stat.ip6s_sources_none++;
1987 	else {
1988 		if (oifp == ifa_best->ia_ifp)
1989 			ip6stat.ip6s_sources_sameif[best_scope]++;
1990 		else
1991 			ip6stat.ip6s_sources_otherif[best_scope]++;
1992 
1993 		if (best_scope == dst_scope)
1994 			ip6stat.ip6s_sources_samescope[best_scope]++;
1995 		else
1996 			ip6stat.ip6s_sources_otherscope[best_scope]++;
1997 
1998 		if ((ifa_best->ia6_flags & IN6_IFF_DEPRECATED) != 0)
1999 			ip6stat.ip6s_sources_deprecated[best_scope]++;
2000 	}
2001 
2002 	return(ifa_best);
2003 }
2004 
2005 /*
2006  * return the best address out of the same scope. if no address was
2007  * found, return the first valid address from designated IF.
2008  */
2009 
2010 struct in6_ifaddr *
2011 in6_ifawithifp(ifp, dst)
2012 	struct ifnet *ifp;
2013 	struct in6_addr *dst;
2014 {
2015 	int dst_scope =	in6_addrscope(dst), blen = -1, tlen;
2016 	struct ifaddr *ifa;
2017 	struct in6_ifaddr *besta = 0;
2018 	struct in6_ifaddr *dep[2];	/*last-resort: deprecated*/
2019 
2020 	dep[0] = dep[1] = NULL;
2021 
2022 	/*
2023 	 * We first look for addresses in the same scope.
2024 	 * If there is one, return it.
2025 	 * If two or more, return one which matches the dst longest.
2026 	 * If none, return one of global addresses assigned other ifs.
2027 	 */
2028 	for (ifa = ifp->if_addrlist.tqh_first;
2029 	     ifa;
2030 	     ifa = ifa->ifa_list.tqe_next)
2031 	{
2032 		if (ifa->ifa_addr->sa_family != AF_INET6)
2033 			continue;
2034 		if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST)
2035 			continue; /* XXX: is there any case to allow anycast? */
2036 		if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_NOTREADY)
2037 			continue; /* don't use this interface */
2038 		if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DETACHED)
2039 			continue;
2040 		if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DEPRECATED) {
2041 			if (ip6_use_deprecated)
2042 				dep[0] = (struct in6_ifaddr *)ifa;
2043 			continue;
2044 		}
2045 
2046 		if (dst_scope == in6_addrscope(IFA_IN6(ifa))) {
2047 			/*
2048 			 * call in6_matchlen() as few as possible
2049 			 */
2050 			if (besta) {
2051 				if (blen == -1)
2052 					blen = in6_matchlen(&besta->ia_addr.sin6_addr, dst);
2053 				tlen = in6_matchlen(IFA_IN6(ifa), dst);
2054 				if (tlen > blen) {
2055 					blen = tlen;
2056 					besta = (struct in6_ifaddr *)ifa;
2057 				}
2058 			} else
2059 				besta = (struct in6_ifaddr *)ifa;
2060 		}
2061 	}
2062 	if (besta)
2063 		return(besta);
2064 
2065 	for (ifa = ifp->if_addrlist.tqh_first;
2066 	     ifa;
2067 	     ifa = ifa->ifa_list.tqe_next)
2068 	{
2069 		if (ifa->ifa_addr->sa_family != AF_INET6)
2070 			continue;
2071 		if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST)
2072 			continue; /* XXX: is there any case to allow anycast? */
2073 		if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_NOTREADY)
2074 			continue; /* don't use this interface */
2075 		if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DETACHED)
2076 			continue;
2077 		if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DEPRECATED) {
2078 			if (ip6_use_deprecated)
2079 				dep[1] = (struct in6_ifaddr *)ifa;
2080 			continue;
2081 		}
2082 
2083 		return (struct in6_ifaddr *)ifa;
2084 	}
2085 
2086 	/* use the last-resort values, that are, deprecated addresses */
2087 	if (dep[0])
2088 		return dep[0];
2089 	if (dep[1])
2090 		return dep[1];
2091 
2092 	return NULL;
2093 }
2094 
2095 /*
2096  * perform DAD when interface becomes IFF_UP.
2097  */
2098 void
2099 in6_if_up(ifp)
2100 	struct ifnet *ifp;
2101 {
2102 	struct ifaddr *ifa;
2103 	struct in6_ifaddr *ia;
2104 	int dad_delay;		/* delay ticks before DAD output */
2105 
2106 	/*
2107 	 * special cases, like 6to4, are handled in in6_ifattach
2108 	 */
2109 	in6_ifattach(ifp, NULL);
2110 
2111 	dad_delay = 0;
2112 	for (ifa = ifp->if_addrlist.tqh_first;
2113 	     ifa;
2114 	     ifa = ifa->ifa_list.tqe_next)
2115 	{
2116 		if (ifa->ifa_addr->sa_family != AF_INET6)
2117 			continue;
2118 		ia = (struct in6_ifaddr *)ifa;
2119 		if (ia->ia6_flags & IN6_IFF_TENTATIVE)
2120 			nd6_dad_start(ifa, &dad_delay);
2121 	}
2122 }
2123 
2124 /*
2125  * Calculate max IPv6 MTU through all the interfaces and store it
2126  * to in6_maxmtu.
2127  */
2128 void
2129 in6_setmaxmtu()
2130 {
2131 	unsigned long maxmtu = 0;
2132 	struct ifnet *ifp;
2133 
2134 	for (ifp = TAILQ_FIRST(&ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list))
2135 	{
2136 		if ((ifp->if_flags & IFF_LOOPBACK) == 0 &&
2137 		    nd_ifinfo[ifp->if_index].linkmtu > maxmtu)
2138 			maxmtu =  nd_ifinfo[ifp->if_index].linkmtu;
2139 	}
2140 	if (maxmtu)	/* update only when maxmtu is positive */
2141 		in6_maxmtu = maxmtu;
2142 }
2143