xref: /netbsd-src/sys/netinet6/in6.c (revision 0dd5877adce57db949b16ae963e5a6831cccdfb6)
1 /*	$NetBSD: in6.c,v 1.52 2001/12/21 08:54:53 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/cdefs.h>
69 __KERNEL_RCSID(0, "$NetBSD: in6.c,v 1.52 2001/12/21 08:54:53 itojun Exp $");
70 
71 #include "opt_inet.h"
72 
73 #include <sys/param.h>
74 #include <sys/ioctl.h>
75 #include <sys/errno.h>
76 #include <sys/malloc.h>
77 #include <sys/socket.h>
78 #include <sys/socketvar.h>
79 #include <sys/sockio.h>
80 #include <sys/systm.h>
81 #include <sys/proc.h>
82 #include <sys/time.h>
83 #include <sys/kernel.h>
84 #include <sys/syslog.h>
85 
86 #include <net/if.h>
87 #include <net/if_types.h>
88 #include <net/route.h>
89 #include <net/if_dl.h>
90 
91 #include <netinet/in.h>
92 #include <netinet/in_var.h>
93 #include <net/if_ether.h>
94 
95 #include <netinet/ip6.h>
96 #include <netinet6/ip6_var.h>
97 #include <netinet6/nd6.h>
98 #include <netinet6/mld6_var.h>
99 #include <netinet6/ip6_mroute.h>
100 #include <netinet6/in6_ifattach.h>
101 
102 #include <net/net_osdep.h>
103 
104 /* enable backward compatibility code for obsoleted ioctls */
105 #define COMPAT_IN6IFIOCTL
106 
107 /*
108  * Definitions of some costant IP6 addresses.
109  */
110 const struct in6_addr in6addr_any = IN6ADDR_ANY_INIT;
111 const struct in6_addr in6addr_loopback = IN6ADDR_LOOPBACK_INIT;
112 const struct in6_addr in6addr_nodelocal_allnodes =
113 	IN6ADDR_NODELOCAL_ALLNODES_INIT;
114 const struct in6_addr in6addr_linklocal_allnodes =
115 	IN6ADDR_LINKLOCAL_ALLNODES_INIT;
116 const struct in6_addr in6addr_linklocal_allrouters =
117 	IN6ADDR_LINKLOCAL_ALLROUTERS_INIT;
118 
119 const struct in6_addr in6mask0 = IN6MASK0;
120 const struct in6_addr in6mask32 = IN6MASK32;
121 const struct in6_addr in6mask64 = IN6MASK64;
122 const struct in6_addr in6mask96 = IN6MASK96;
123 const struct in6_addr in6mask128 = IN6MASK128;
124 
125 const struct sockaddr_in6 sa6_any = {sizeof(sa6_any), AF_INET6,
126 				     0, 0, IN6ADDR_ANY_INIT, 0};
127 
128 static int in6_lifaddr_ioctl __P((struct socket *, u_long, caddr_t,
129 	struct ifnet *, struct proc *));
130 static int in6_ifinit __P((struct ifnet *, struct in6_ifaddr *,
131 			   struct sockaddr_in6 *, int));
132 
133 /*
134  * This structure is used to keep track of in6_multi chains which belong to
135  * deleted interface addresses.
136  */
137 static LIST_HEAD(, multi6_kludge) in6_mk; /* XXX BSS initialization */
138 
139 struct multi6_kludge {
140 	LIST_ENTRY(multi6_kludge) mk_entry;
141 	struct ifnet *mk_ifp;
142 	struct in6_multihead mk_head;
143 };
144 
145 /*
146  * Check if the loopback entry will be automatically generated.
147  *   if 0 returned, will not be automatically generated.
148  *   if 1 returned, will be automatically generated.
149  */
150 static int
151 in6_is_ifloop_auto(struct ifaddr *ifa)
152 {
153 #define SIN6(s) ((struct sockaddr_in6 *)s)
154 	/*
155 	 * If RTF_CLONING is unset, or (IFF_LOOPBACK | IFF_POINTOPOINT),
156 	 * or netmask is all0 or all1, then cloning will not happen,
157 	 * then we can't rely on its loopback entry generation.
158 	 */
159 	if ((ifa->ifa_flags & RTF_CLONING) == 0 ||
160 	    (ifa->ifa_ifp->if_flags & (IFF_LOOPBACK | IFF_POINTOPOINT)) ||
161 	    (SIN6(ifa->ifa_netmask)->sin6_len == sizeof(struct sockaddr_in6)
162 	     &&
163 	     IN6_ARE_ADDR_EQUAL(&SIN6(ifa->ifa_netmask)->sin6_addr,
164 				&in6mask128)) ||
165 	    ((struct sockaddr_in6 *)ifa->ifa_netmask)->sin6_len == 0)
166 		return 0;
167 	else
168 		return 1;
169 #undef SIN6
170 }
171 
172 /*
173  * Subroutine for in6_ifaddloop() and in6_ifremloop().
174  * This routine does actual work.
175  */
176 static void
177 in6_ifloop_request(int cmd, struct ifaddr *ifa)
178 {
179 	struct sockaddr_in6 lo_sa;
180 	struct sockaddr_in6 all1_sa;
181 	struct rtentry *nrt = NULL, **nrtp = NULL;
182 
183 	bzero(&lo_sa, sizeof(lo_sa));
184 	bzero(&all1_sa, sizeof(all1_sa));
185 	lo_sa.sin6_family = AF_INET6;
186 	lo_sa.sin6_len = sizeof(struct sockaddr_in6);
187 	all1_sa = lo_sa;
188 	lo_sa.sin6_addr = in6addr_loopback;
189 	all1_sa.sin6_addr = in6mask128;
190 
191 	/*
192 	 * So we add or remove static loopback entry, here.
193 	 * This request for deletion could fail, e.g. when we remove
194 	 * an address right after adding it.
195 	 */
196 	if (cmd == RTM_ADD)
197 		nrtp = &nrt;
198 	rtrequest(cmd, ifa->ifa_addr,
199 		  (struct sockaddr *)&lo_sa,
200 		  (struct sockaddr *)&all1_sa,
201 		  RTF_UP|RTF_HOST, nrtp);
202 
203 	/*
204 	 * Make sure rt_ifa be equal to IFA, the second argument of the
205 	 * function.
206 	 * We need this because when we refer to rt_ifa->ia6_flags in
207 	 * ip6_input, we assume that the rt_ifa points to the address instead
208 	 * of the loopback address.
209 	 */
210 	if (cmd == RTM_ADD && nrt && ifa != nrt->rt_ifa) {
211 		IFAFREE(nrt->rt_ifa);
212 		IFAREF(ifa);
213 		nrt->rt_ifa = ifa;
214 	}
215 	if (nrt)
216 		nrt->rt_refcnt--;
217 }
218 
219 /*
220  * Add ownaddr as loopback rtentry, if necessary(ex. on p2p link).
221  * Because, KAME needs loopback rtentry for ownaddr check in
222  * ip6_input().
223  */
224 static void
225 in6_ifaddloop(struct ifaddr *ifa)
226 {
227 	if (!in6_is_ifloop_auto(ifa)) {
228 		struct rtentry *rt;
229 
230 		/* If there is no loopback entry, allocate one. */
231 		rt = rtalloc1(ifa->ifa_addr, 0);
232 		if (rt == 0 || (rt->rt_ifp->if_flags & IFF_LOOPBACK) == 0)
233 			in6_ifloop_request(RTM_ADD, ifa);
234 		if (rt)
235 			rt->rt_refcnt--;
236 	}
237 }
238 
239 /*
240  * Remove loopback rtentry of ownaddr generated by in6_ifaddloop(),
241  * if it exists.
242  */
243 static void
244 in6_ifremloop(struct ifaddr *ifa)
245 {
246 	if (!in6_is_ifloop_auto(ifa)) {
247 		struct in6_ifaddr *ia;
248 		int ia_count = 0;
249 
250 		/* If only one ifa for the loopback entry, delete it. */
251 		for (ia = in6_ifaddr; ia; ia = ia->ia_next) {
252 			if (IN6_ARE_ADDR_EQUAL(IFA_IN6(ifa),
253 					       &ia->ia_addr.sin6_addr)) {
254 				ia_count++;
255 				if (ia_count > 1)
256 					break;
257 			}
258 		}
259 		if (ia_count == 1)
260 			in6_ifloop_request(RTM_DELETE, ifa);
261 	}
262 }
263 
264 int
265 in6_ifindex2scopeid(idx)
266 	int idx;
267 {
268 	struct ifnet *ifp;
269 	struct ifaddr *ifa;
270 	struct sockaddr_in6 *sin6;
271 
272 	if (idx < 0 || if_index < idx)
273 		return -1;
274 	ifp = ifindex2ifnet[idx];
275 	if (!ifp)
276 		return -1;
277 
278 	for (ifa = ifp->if_addrlist.tqh_first; ifa; ifa = ifa->ifa_list.tqe_next)
279 	{
280 		if (ifa->ifa_addr->sa_family != AF_INET6)
281 			continue;
282 		sin6 = (struct sockaddr_in6 *)ifa->ifa_addr;
283 		if (IN6_IS_ADDR_SITELOCAL(&sin6->sin6_addr))
284 			return sin6->sin6_scope_id & 0xffff;
285 	}
286 
287 	return -1;
288 }
289 
290 int
291 in6_mask2len(mask)
292 	struct in6_addr *mask;
293 {
294 	int x, y;
295 
296 	for (x = 0; x < sizeof(*mask); x++) {
297 		if (mask->s6_addr8[x] != 0xff)
298 			break;
299 	}
300 	y = 0;
301 	if (x < sizeof(*mask)) {
302 		for (y = 0; y < 8; y++) {
303 			if ((mask->s6_addr8[x] & (0x80 >> y)) == 0)
304 				break;
305 		}
306 	}
307 	return x * 8 + y;
308 }
309 
310 void
311 in6_len2mask(mask, len)
312 	struct in6_addr *mask;
313 	int len;
314 {
315 	int i;
316 
317 	bzero(mask, sizeof(*mask));
318 	for (i = 0; i < len / 8; i++)
319 		mask->s6_addr8[i] = 0xff;
320 	if (len % 8)
321 		mask->s6_addr8[i] = (0xff00 >> (len % 8)) & 0xff;
322 }
323 
324 #define ifa2ia6(ifa)	((struct in6_ifaddr *)(ifa))
325 #define ia62ifa(ia6)	(&((ia6)->ia_ifa))
326 
327 int
328 in6_control(so, cmd, data, ifp, p)
329 	struct	socket *so;
330 	u_long cmd;
331 	caddr_t	data;
332 	struct ifnet *ifp;
333 	struct proc *p;
334 {
335 	struct	in6_ifreq *ifr = (struct in6_ifreq *)data;
336 	struct	in6_ifaddr *ia, *oia;
337 	struct	in6_aliasreq *ifra = (struct in6_aliasreq *)data;
338 	struct	sockaddr_in6 oldaddr;
339 #ifdef COMPAT_IN6IFIOCTL
340 	struct	sockaddr_in6 net;
341 #endif
342 	int error = 0, hostIsNew, prefixIsNew;
343 	int newifaddr;
344 	time_t time_second = (time_t)time.tv_sec;
345 	int privileged;
346 
347 	privileged = 0;
348 	if (p && !suser(p->p_ucred, &p->p_acflag))
349 		privileged++;
350 
351 	switch (cmd) {
352 	case SIOCGETSGCNT_IN6:
353 	case SIOCGETMIFCNT_IN6:
354 		return (mrt6_ioctl(cmd, data));
355 	}
356 
357 	if (ifp == NULL)
358 		return(EOPNOTSUPP);
359 
360 	switch (cmd) {
361 	case SIOCSNDFLUSH_IN6:
362 	case SIOCSPFXFLUSH_IN6:
363 	case SIOCSRTRFLUSH_IN6:
364 	case SIOCSDEFIFACE_IN6:
365 	case SIOCSIFINFO_FLAGS:
366 		if (!privileged)
367 			return(EPERM);
368 		/* fall through */
369 	case SIOCGIFINFO_IN6:
370 	case SIOCGDRLST_IN6:
371 	case SIOCGPRLST_IN6:
372 	case SIOCGNBRINFO_IN6:
373 	case SIOCGDEFIFACE_IN6:
374 		return(nd6_ioctl(cmd, data, ifp));
375 	}
376 
377 	switch (cmd) {
378 	case SIOCSIFPREFIX_IN6:
379 	case SIOCDIFPREFIX_IN6:
380 	case SIOCAIFPREFIX_IN6:
381 	case SIOCCIFPREFIX_IN6:
382 	case SIOCSGIFPREFIX_IN6:
383 		if (!privileged)
384 			return(EPERM);
385 		/* fall through */
386 	case SIOCGIFPREFIX_IN6:
387 		return(in6_prefix_ioctl(so, cmd, data, ifp));
388 	}
389 
390 	switch (cmd) {
391 	case SIOCALIFADDR:
392 	case SIOCDLIFADDR:
393 		if (!privileged)
394 			return(EPERM);
395 		/* fall through */
396 	case SIOCGLIFADDR:
397 		return in6_lifaddr_ioctl(so, cmd, data, ifp, p);
398 	}
399 
400 	/*
401 	 * Find address for this interface, if it exists.
402 	 */
403 	if (ifra->ifra_addr.sin6_family == AF_INET6) { /* XXX */
404 		struct sockaddr_in6 *sa6 =
405 			(struct sockaddr_in6 *)&ifra->ifra_addr;
406 
407 		if (IN6_IS_ADDR_LINKLOCAL(&sa6->sin6_addr)) {
408 			if (sa6->sin6_addr.s6_addr16[1] == 0) {
409 				/* interface ID is not embedded by the user */
410 				sa6->sin6_addr.s6_addr16[1] =
411 					htons(ifp->if_index);
412 			} else if (sa6->sin6_addr.s6_addr16[1] !=
413 				    htons(ifp->if_index)) {
414 				return(EINVAL);	/* link ID contradicts */
415 			}
416 			if (sa6->sin6_scope_id) {
417 				if (sa6->sin6_scope_id !=
418 				    (u_int32_t)ifp->if_index)
419 					return(EINVAL);
420 				sa6->sin6_scope_id = 0; /* XXX: good way? */
421 			}
422 		}
423 		ia = in6ifa_ifpwithaddr(ifp, &ifra->ifra_addr.sin6_addr);
424 	} else
425 		ia = NULL;
426 
427 	switch (cmd) {
428 
429 	case SIOCDIFADDR_IN6:
430 		/*
431 		 * for IPv4, we look for existing in_ifaddr here to allow
432 		 * "ifconfig if0 delete" to remove the first IPv4 address on
433 		 * the interface.  For IPv6, as the spec allows multiple
434 		 * interface address from the day one, we consider "remove the
435 		 * first one" semantics to be not preferable.
436 		 */
437 		if (ia == NULL)
438 			return(EADDRNOTAVAIL);
439 		/* FALLTHROUGH */
440 	case SIOCAIFADDR_IN6:
441 	case SIOCSIFADDR_IN6:
442 #ifdef COMPAT_IN6IFIOCTL
443 	case SIOCSIFDSTADDR_IN6:
444 	case SIOCSIFNETMASK_IN6:
445 		/*
446 		 * Since IPv6 allows a node to assign multiple addresses
447 		 * on a single interface, SIOCSIFxxx ioctls are not suitable
448 		 * and should be unused.
449 		 */
450 #endif
451 		if (ifra->ifra_addr.sin6_family != AF_INET6)
452 			return(EAFNOSUPPORT);
453 		if (!privileged)
454 			return(EPERM);
455 		if (ia == NULL) {
456 			ia = (struct in6_ifaddr *)
457 				malloc(sizeof(*ia), M_IFADDR, M_WAITOK);
458 			if (ia == NULL)
459 				return (ENOBUFS);
460 			bzero((caddr_t)ia, sizeof(*ia));
461 			/* Initialize the address and masks */
462 			ia->ia_ifa.ifa_addr = (struct sockaddr *)&ia->ia_addr;
463 			ia->ia_addr.sin6_family = AF_INET6;
464 			ia->ia_addr.sin6_len = sizeof(ia->ia_addr);
465 			if (ifp->if_flags & IFF_POINTOPOINT) {
466 				ia->ia_ifa.ifa_dstaddr
467 					= (struct sockaddr *)&ia->ia_dstaddr;
468 				ia->ia_dstaddr.sin6_family = AF_INET6;
469 				ia->ia_dstaddr.sin6_len = sizeof(ia->ia_dstaddr);
470 			} else {
471 				ia->ia_ifa.ifa_dstaddr = NULL;
472 				bzero(&ia->ia_dstaddr, sizeof(ia->ia_dstaddr));
473 			}
474 			ia->ia_ifa.ifa_netmask
475 				= (struct sockaddr *)&ia->ia_prefixmask;
476 
477 			ia->ia_ifp = ifp;
478 			if ((oia = in6_ifaddr) != NULL) {
479 				for ( ; oia->ia_next; oia = oia->ia_next)
480 					continue;
481 				oia->ia_next = ia;
482 			} else
483 				in6_ifaddr = ia;
484 			IFAREF(&ia->ia_ifa);
485 
486 			TAILQ_INSERT_TAIL(&ifp->if_addrlist, &ia->ia_ifa,
487 			    ifa_list);
488 			IFAREF(&ia->ia_ifa);
489 
490 			newifaddr = 1;
491 		} else
492 			newifaddr = 0;
493 
494 		if (cmd == SIOCAIFADDR_IN6) {
495 			/* sanity for overflow - beware unsigned */
496 			struct in6_addrlifetime *lt;
497 			lt = &ifra->ifra_lifetime;
498 			if (lt->ia6t_vltime != ND6_INFINITE_LIFETIME
499 			 && lt->ia6t_vltime + time_second < time_second) {
500 				return EINVAL;
501 			}
502 			if (lt->ia6t_pltime != ND6_INFINITE_LIFETIME
503 			 && lt->ia6t_pltime + time_second < time_second) {
504 				return EINVAL;
505 			}
506 		}
507 		break;
508 
509 	case SIOCGIFADDR_IN6:
510 		/* This interface is basically deprecated. use SIOCGIFCONF. */
511 		/* fall through */
512 	case SIOCGIFAFLAG_IN6:
513 	case SIOCGIFNETMASK_IN6:
514 	case SIOCGIFDSTADDR_IN6:
515 	case SIOCGIFALIFETIME_IN6:
516 		/* must think again about its semantics */
517 		if (ia == NULL)
518 			return(EADDRNOTAVAIL);
519 		break;
520 	case SIOCSIFALIFETIME_IN6:
521 	    {
522 		struct in6_addrlifetime *lt;
523 
524 		if (!privileged)
525 			return(EPERM);
526 		if (ia == NULL)
527 			return(EADDRNOTAVAIL);
528 		/* sanity for overflow - beware unsigned */
529 		lt = &ifr->ifr_ifru.ifru_lifetime;
530 		if (lt->ia6t_vltime != ND6_INFINITE_LIFETIME
531 		 && lt->ia6t_vltime + time_second < time_second) {
532 			return EINVAL;
533 		}
534 		if (lt->ia6t_pltime != ND6_INFINITE_LIFETIME
535 		 && lt->ia6t_pltime + time_second < time_second) {
536 			return EINVAL;
537 		}
538 		break;
539 	    }
540 	}
541 
542 	switch (cmd) {
543 
544 	case SIOCGIFADDR_IN6:
545 		ifr->ifr_addr = ia->ia_addr;
546 		break;
547 
548 	case SIOCGIFDSTADDR_IN6:
549 		if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
550 			return(EINVAL);
551 		/*
552 		 * XXX: should we check if ifa_dstaddr is NULL and return
553 		 * an error?
554 		 */
555 		ifr->ifr_dstaddr = ia->ia_dstaddr;
556 		break;
557 
558 	case SIOCGIFNETMASK_IN6:
559 		ifr->ifr_addr = ia->ia_prefixmask;
560 		break;
561 
562 	case SIOCGIFAFLAG_IN6:
563 		ifr->ifr_ifru.ifru_flags6 = ia->ia6_flags;
564 		break;
565 
566 	case SIOCGIFSTAT_IN6:
567 		if (ifp == NULL)
568 			return EINVAL;
569 		if (in6_ifstat == NULL || ifp->if_index >= in6_ifstatmax
570 		 || in6_ifstat[ifp->if_index] == NULL) {
571 			/* return EAFNOSUPPORT? */
572 			bzero(&ifr->ifr_ifru.ifru_stat,
573 				sizeof(ifr->ifr_ifru.ifru_stat));
574 		} else
575 			ifr->ifr_ifru.ifru_stat = *in6_ifstat[ifp->if_index];
576 		break;
577 
578 	case SIOCGIFSTAT_ICMP6:
579 		if (ifp == NULL)
580 			return EINVAL;
581 		if (icmp6_ifstat == NULL || ifp->if_index >= icmp6_ifstatmax ||
582 		    icmp6_ifstat[ifp->if_index] == NULL) {
583 			/* return EAFNOSUPPORT? */
584 			bzero(&ifr->ifr_ifru.ifru_stat,
585 				sizeof(ifr->ifr_ifru.ifru_icmp6stat));
586 		} else
587 			ifr->ifr_ifru.ifru_icmp6stat =
588 				*icmp6_ifstat[ifp->if_index];
589 		break;
590 
591 #ifdef COMPAT_IN6IFIOCTL		/* should be unused */
592 	case SIOCSIFDSTADDR_IN6:
593 		if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
594 			return(EINVAL);
595 		oldaddr = ia->ia_dstaddr;
596 		ia->ia_dstaddr = ifr->ifr_dstaddr;
597 
598 		/* link-local index check */
599 		if (IN6_IS_ADDR_LINKLOCAL(&ia->ia_dstaddr.sin6_addr)) {
600 			if (ia->ia_dstaddr.sin6_addr.s6_addr16[1] == 0) {
601 				/* interface ID is not embedded by the user */
602 				ia->ia_dstaddr.sin6_addr.s6_addr16[1]
603 					= htons(ifp->if_index);
604 			} else if (ia->ia_dstaddr.sin6_addr.s6_addr16[1] !=
605 				    htons(ifp->if_index)) {
606 				ia->ia_dstaddr = oldaddr;
607 				return(EINVAL);	/* ifid contradicts */
608 			}
609 		}
610 
611 		if (ifp->if_ioctl && (error = (ifp->if_ioctl)
612 				      (ifp, SIOCSIFDSTADDR, (caddr_t)ia))) {
613 			ia->ia_dstaddr = oldaddr;
614 			return(error);
615 		}
616 		if (ia->ia_flags & IFA_ROUTE) {
617 			ia->ia_ifa.ifa_dstaddr = (struct sockaddr *)&oldaddr;
618 			rtinit(&(ia->ia_ifa), (int)RTM_DELETE, RTF_HOST);
619 			ia->ia_ifa.ifa_dstaddr =
620 				(struct sockaddr *)&ia->ia_dstaddr;
621 			rtinit(&(ia->ia_ifa), (int)RTM_ADD, RTF_HOST|RTF_UP);
622 		}
623 		break;
624 
625 #endif
626 	case SIOCGIFALIFETIME_IN6:
627 		ifr->ifr_ifru.ifru_lifetime = ia->ia6_lifetime;
628 		break;
629 
630 	case SIOCSIFALIFETIME_IN6:
631 		ia->ia6_lifetime = ifr->ifr_ifru.ifru_lifetime;
632 		/* for sanity */
633 		if (ia->ia6_lifetime.ia6t_vltime != ND6_INFINITE_LIFETIME) {
634 			ia->ia6_lifetime.ia6t_expire =
635 				time_second + ia->ia6_lifetime.ia6t_vltime;
636 		} else
637 			ia->ia6_lifetime.ia6t_expire = 0;
638 		if (ia->ia6_lifetime.ia6t_pltime != ND6_INFINITE_LIFETIME) {
639 			ia->ia6_lifetime.ia6t_preferred =
640 				time_second + ia->ia6_lifetime.ia6t_pltime;
641 		} else
642 			ia->ia6_lifetime.ia6t_preferred = 0;
643 		break;
644 
645 	case SIOCSIFADDR_IN6:
646 		error = in6_ifinit(ifp, ia, &ifr->ifr_addr, 1);
647 #if 0
648 		/*
649 		 * the code chokes if we are to assign multiple addresses with
650 		 * the same address prefix (rtinit() will return EEXIST, which
651 		 * is not fatal actually).  we will get memory leak if we
652 		 * don't do it.
653 		 * -> we may want to hide EEXIST from rtinit().
654 		 */
655   undo:
656 		if (error && newifaddr) {
657 			TAILQ_REMOVE(&ifp->if_addrlist, &ia->ia_ifa, ifa_list);
658 			IFAFREE(&ia->ia_ifa);
659 
660 			oia = ia;
661 			if (oia == (ia = in6_ifaddr))
662 				in6_ifaddr = ia->ia_next;
663 			else {
664 				while (ia->ia_next && (ia->ia_next != oia))
665 					ia = ia->ia_next;
666 				if (ia->ia_next)
667 					ia->ia_next = oia->ia_next;
668 				else {
669 					printf("Didn't unlink in6_ifaddr "
670 					    "from list\n");
671 				}
672 			}
673 			IFAFREE(&oia->ia_ifa);
674 		}
675 #endif
676 		return error;
677 
678 #ifdef COMPAT_IN6IFIOCTL		/* XXX should be unused */
679 	case SIOCSIFNETMASK_IN6:
680 		ia->ia_prefixmask = ifr->ifr_addr;
681 		bzero(&net, sizeof(net));
682 		net.sin6_len = sizeof(struct sockaddr_in6);
683 		net.sin6_family = AF_INET6;
684 		net.sin6_port = htons(0);
685 		net.sin6_flowinfo = htonl(0);
686 		net.sin6_addr.s6_addr32[0]
687 			= ia->ia_addr.sin6_addr.s6_addr32[0] &
688 				ia->ia_prefixmask.sin6_addr.s6_addr32[0];
689 		net.sin6_addr.s6_addr32[1]
690 			= ia->ia_addr.sin6_addr.s6_addr32[1] &
691 				ia->ia_prefixmask.sin6_addr.s6_addr32[1];
692 		net.sin6_addr.s6_addr32[2]
693 			= ia->ia_addr.sin6_addr.s6_addr32[2] &
694 				ia->ia_prefixmask.sin6_addr.s6_addr32[2];
695 		net.sin6_addr.s6_addr32[3]
696 			= ia->ia_addr.sin6_addr.s6_addr32[3] &
697 				ia->ia_prefixmask.sin6_addr.s6_addr32[3];
698 		ia->ia_net = net;
699 		break;
700 #endif
701 
702 	case SIOCAIFADDR_IN6:
703 		prefixIsNew = 0;
704 		hostIsNew = 1;
705 
706 		if (ifra->ifra_addr.sin6_len == 0) {
707 			ifra->ifra_addr = ia->ia_addr;
708 			hostIsNew = 0;
709 		} else if (IN6_ARE_ADDR_EQUAL(&ifra->ifra_addr.sin6_addr,
710 					      &ia->ia_addr.sin6_addr))
711 			hostIsNew = 0;
712 
713 		/* Validate address families: */
714 		/*
715 		 * The destination address for a p2p link must have a family
716 		 * of AF_UNSPEC or AF_INET6.
717 		 */
718 		if ((ifp->if_flags & IFF_POINTOPOINT) != 0 &&
719 		    ifra->ifra_dstaddr.sin6_family != AF_INET6 &&
720 		    ifra->ifra_dstaddr.sin6_family != AF_UNSPEC)
721 			return(EAFNOSUPPORT);
722 		/*
723 		 * The prefixmask must have a family of AF_UNSPEC or AF_INET6.
724 		 */
725 		if (ifra->ifra_prefixmask.sin6_family != AF_INET6 &&
726 		    ifra->ifra_prefixmask.sin6_family != AF_UNSPEC)
727 			return(EAFNOSUPPORT);
728 
729 		if (ifra->ifra_prefixmask.sin6_len) {
730 			in6_ifscrub(ifp, ia);
731 			ia->ia_prefixmask = ifra->ifra_prefixmask;
732 			prefixIsNew = 1;
733 		}
734 		if ((ifp->if_flags & IFF_POINTOPOINT) &&
735 		    (ifra->ifra_dstaddr.sin6_family == AF_INET6)) {
736 			in6_ifscrub(ifp, ia);
737 			oldaddr = ia->ia_dstaddr;
738 			ia->ia_dstaddr = ifra->ifra_dstaddr;
739 			/* link-local index check: should be a separate function? */
740 			if (IN6_IS_ADDR_LINKLOCAL(&ia->ia_dstaddr.sin6_addr)) {
741 				if (ia->ia_dstaddr.sin6_addr.s6_addr16[1] == 0) {
742 					/*
743 					 * interface ID is not embedded by
744 					 * the user
745 					 */
746 					ia->ia_dstaddr.sin6_addr.s6_addr16[1]
747 						= htons(ifp->if_index);
748 				} else if (ia->ia_dstaddr.sin6_addr.s6_addr16[1] !=
749 					    htons(ifp->if_index)) {
750 					ia->ia_dstaddr = oldaddr;
751 					return(EINVAL);	/* ifid contradicts */
752 				}
753 			}
754 			prefixIsNew = 1; /* We lie; but effect's the same */
755 		}
756 		if (hostIsNew || prefixIsNew) {
757 			error = in6_ifinit(ifp, ia, &ifra->ifra_addr, 0);
758 #if 0
759 			if (error)
760 				goto undo;
761 #endif
762 		}
763 		if (hostIsNew && (ifp->if_flags & IFF_MULTICAST)) {
764 			int error_local = 0;
765 
766 			/*
767 			 * join solicited multicast addr for new host id
768 			 */
769 			struct in6_addr llsol;
770 			bzero(&llsol, sizeof(struct in6_addr));
771 			llsol.s6_addr16[0] = htons(0xff02);
772 			llsol.s6_addr16[1] = htons(ifp->if_index);
773 			llsol.s6_addr32[1] = 0;
774 			llsol.s6_addr32[2] = htonl(1);
775 			llsol.s6_addr32[3] =
776 				ifra->ifra_addr.sin6_addr.s6_addr32[3];
777 			llsol.s6_addr8[12] = 0xff;
778 			(void)in6_addmulti(&llsol, ifp, &error_local);
779 			if (error == 0)
780 				error = error_local;
781 		}
782 
783 		ia->ia6_flags = ifra->ifra_flags;
784 		ia->ia6_flags &= ~IN6_IFF_DUPLICATED;	/*safety*/
785 
786 		ia->ia6_lifetime = ifra->ifra_lifetime;
787 		/* for sanity */
788 		if (ia->ia6_lifetime.ia6t_vltime != ND6_INFINITE_LIFETIME) {
789 			ia->ia6_lifetime.ia6t_expire =
790 				time_second + ia->ia6_lifetime.ia6t_vltime;
791 		} else
792 			ia->ia6_lifetime.ia6t_expire = 0;
793 		if (ia->ia6_lifetime.ia6t_pltime != ND6_INFINITE_LIFETIME) {
794 			ia->ia6_lifetime.ia6t_preferred =
795 				time_second + ia->ia6_lifetime.ia6t_pltime;
796 		} else
797 			ia->ia6_lifetime.ia6t_preferred = 0;
798 
799 		/*
800 		 * make sure to initialize ND6 information.  this is to
801 		 * workaround issues with interfaces with IPv6 addresses,
802 		 * which have never brought # up.  we are assuming that it is
803 		 * safe to nd6_ifattach multiple times.
804 		 */
805 		nd6_ifattach(ifp);
806 
807 		/*
808 		 * Perform DAD, if needed.
809 		 * XXX It may be of use, if we can administratively
810 		 * disable DAD.
811 		 */
812 		switch (ifp->if_type) {
813 		case IFT_ARCNET:
814 		case IFT_ETHER:
815 		case IFT_FDDI:
816 		case IFT_IEEE1394:
817 #if 0
818 		case IFT_ATM:
819 		case IFT_SLIP:
820 		case IFT_PPP:
821 #endif
822 			ia->ia6_flags |= IN6_IFF_TENTATIVE;
823 			nd6_dad_start(&ia->ia_ifa, NULL);
824 			break;
825 		case IFT_FAITH:
826 		case IFT_GIF:
827 		case IFT_LOOP:
828 		default:
829 			break;
830 		}
831 
832 		if (hostIsNew) {
833 			int iilen;
834 			int error_local = 0;
835 
836 			iilen = (sizeof(ia->ia_prefixmask.sin6_addr) << 3) -
837 				in6_mask2len(&ia->ia_prefixmask.sin6_addr);
838 			error_local = in6_prefix_add_ifid(iilen, ia);
839 			if (error == 0)
840 				error = error_local;
841 		}
842 
843 		return(error);
844 
845 	case SIOCDIFADDR_IN6:
846 		in6_purgeaddr(&ia->ia_ifa, ifp);
847 		break;
848 
849 	default:
850 		if (ifp == NULL || ifp->if_ioctl == 0)
851 			return(EOPNOTSUPP);
852 		return((*ifp->if_ioctl)(ifp, cmd, data));
853 	}
854 
855 	return(0);
856 }
857 
858 void
859 in6_purgeaddr(ifa, ifp)
860 	struct ifaddr *ifa;
861 	struct ifnet *ifp;
862 {
863 	struct in6_ifaddr *oia, *ia = (void *) ifa;
864 
865 	/* stop DAD processing */
866 	nd6_dad_stop(ifa);
867 
868 	in6_ifscrub(ifp, ia);
869 
870 	if (ifp->if_flags & IFF_MULTICAST) {
871 		/*
872 		 * delete solicited multicast addr for deleting host id
873 		 */
874 		struct in6_multi *in6m;
875 		struct in6_addr llsol;
876 		bzero(&llsol, sizeof(struct in6_addr));
877 		llsol.s6_addr16[0] = htons(0xff02);
878 		llsol.s6_addr16[1] = htons(ifp->if_index);
879 		llsol.s6_addr32[1] = 0;
880 		llsol.s6_addr32[2] = htonl(1);
881 		llsol.s6_addr32[3] =
882 			ia->ia_addr.sin6_addr.s6_addr32[3];
883 		llsol.s6_addr8[12] = 0xff;
884 
885 		IN6_LOOKUP_MULTI(llsol, ifp, in6m);
886 		if (in6m)
887 			in6_delmulti(in6m);
888 	}
889 
890 	TAILQ_REMOVE(&ifp->if_addrlist, &ia->ia_ifa, ifa_list);
891 	IFAFREE(&ia->ia_ifa);
892 
893 	oia = ia;
894 	if (oia == (ia = in6_ifaddr))
895 		in6_ifaddr = ia->ia_next;
896 	else {
897 		while (ia->ia_next && (ia->ia_next != oia))
898 			ia = ia->ia_next;
899 		if (ia->ia_next)
900 			ia->ia_next = oia->ia_next;
901 		else
902 			printf("Didn't unlink in6_ifaddr from list\n");
903 	}
904 	{
905 		int iilen;
906 
907 		iilen = (sizeof(oia->ia_prefixmask.sin6_addr) << 3) -
908 			in6_mask2len(&oia->ia_prefixmask.sin6_addr);
909 		in6_prefix_remove_ifid(iilen, oia);
910 	}
911 	if (oia->ia6_multiaddrs.lh_first != NULL) {
912 		/*
913 		 * XXX thorpej@netbsd.org -- if the interface is going
914 		 * XXX away, don't save the multicast entries, delete them!
915 		 */
916 		if (oia->ia_ifa.ifa_ifp->if_output == if_nulloutput) {
917 			struct in6_multi *in6m;
918 
919 			while ((in6m =
920 			    LIST_FIRST(&oia->ia6_multiaddrs)) != NULL)
921 				in6_delmulti(in6m);
922 		} else
923 			in6_savemkludge(oia);
924 	}
925 
926 	IFAFREE(&oia->ia_ifa);
927 }
928 
929 void
930 in6_purgeif(ifp)
931 	struct ifnet *ifp;
932 {
933 	struct ifaddr *ifa, *nifa;
934 
935 	for (ifa = TAILQ_FIRST(&ifp->if_addrlist); ifa != NULL; ifa = nifa)
936 	{
937 		nifa = TAILQ_NEXT(ifa, ifa_list);
938 		if (ifa->ifa_addr->sa_family != AF_INET6)
939 			continue;
940 		in6_purgeaddr(ifa, ifp);
941 	}
942 
943 	in6_ifdetach(ifp);
944 }
945 
946 /*
947  * SIOC[GAD]LIFADDR.
948  *	SIOCGLIFADDR: get first address. (?)
949  *	SIOCGLIFADDR with IFLR_PREFIX:
950  *		get first address that matches the specified prefix.
951  *	SIOCALIFADDR: add the specified address.
952  *	SIOCALIFADDR with IFLR_PREFIX:
953  *		add the specified prefix, filling hostid part from
954  *		the first link-local address.  prefixlen must be <= 64.
955  *	SIOCDLIFADDR: delete the specified address.
956  *	SIOCDLIFADDR with IFLR_PREFIX:
957  *		delete the first address that matches the specified prefix.
958  * return values:
959  *	EINVAL on invalid parameters
960  *	EADDRNOTAVAIL on prefix match failed/specified address not found
961  *	other values may be returned from in6_ioctl()
962  *
963  * NOTE: SIOCALIFADDR(with IFLR_PREFIX set) allows prefixlen less than 64.
964  * this is to accomodate address naming scheme other than RFC2374,
965  * in the future.
966  * RFC2373 defines interface id to be 64bit, but it allows non-RFC2374
967  * address encoding scheme. (see figure on page 8)
968  */
969 static int
970 in6_lifaddr_ioctl(so, cmd, data, ifp, p)
971 	struct socket *so;
972 	u_long cmd;
973 	caddr_t	data;
974 	struct ifnet *ifp;
975 	struct proc *p;
976 {
977 	struct if_laddrreq *iflr = (struct if_laddrreq *)data;
978 	struct ifaddr *ifa;
979 	struct sockaddr *sa;
980 
981 	/* sanity checks */
982 	if (!data || !ifp) {
983 		panic("invalid argument to in6_lifaddr_ioctl");
984 		/* NOTREACHED */
985 	}
986 
987 	switch (cmd) {
988 	case SIOCGLIFADDR:
989 		/* address must be specified on GET with IFLR_PREFIX */
990 		if ((iflr->flags & IFLR_PREFIX) == 0)
991 			break;
992 		/* FALLTHROUGH */
993 	case SIOCALIFADDR:
994 	case SIOCDLIFADDR:
995 		/* address must be specified on ADD and DELETE */
996 		sa = (struct sockaddr *)&iflr->addr;
997 		if (sa->sa_family != AF_INET6)
998 			return EINVAL;
999 		if (sa->sa_len != sizeof(struct sockaddr_in6))
1000 			return EINVAL;
1001 		/* XXX need improvement */
1002 		sa = (struct sockaddr *)&iflr->dstaddr;
1003 		if (sa->sa_family && sa->sa_family != AF_INET6)
1004 			return EINVAL;
1005 		if (sa->sa_len && sa->sa_len != sizeof(struct sockaddr_in6))
1006 			return EINVAL;
1007 		break;
1008 	default: /* shouldn't happen */
1009 #if 0
1010 		panic("invalid cmd to in6_lifaddr_ioctl");
1011 		/* NOTREACHED */
1012 #else
1013 		return EOPNOTSUPP;
1014 #endif
1015 	}
1016 	if (sizeof(struct in6_addr) * 8 < iflr->prefixlen)
1017 		return EINVAL;
1018 
1019 	switch (cmd) {
1020 	case SIOCALIFADDR:
1021 	    {
1022 		struct in6_aliasreq ifra;
1023 		struct in6_addr *hostid = NULL;
1024 		int prefixlen;
1025 
1026 		if ((iflr->flags & IFLR_PREFIX) != 0) {
1027 			struct sockaddr_in6 *sin6;
1028 
1029 			/*
1030 			 * hostid is to fill in the hostid part of the
1031 			 * address.  hostid points to the first link-local
1032 			 * address attached to the interface.
1033 			 */
1034 			ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp, 0);
1035 			if (!ifa)
1036 				return EADDRNOTAVAIL;
1037 			hostid = IFA_IN6(ifa);
1038 
1039 		 	/* prefixlen must be <= 64. */
1040 			if (64 < iflr->prefixlen)
1041 				return EINVAL;
1042 			prefixlen = iflr->prefixlen;
1043 
1044 			/* hostid part must be zero. */
1045 			sin6 = (struct sockaddr_in6 *)&iflr->addr;
1046 			if (sin6->sin6_addr.s6_addr32[2] != 0
1047 			 || sin6->sin6_addr.s6_addr32[3] != 0) {
1048 				return EINVAL;
1049 			}
1050 		} else
1051 			prefixlen = iflr->prefixlen;
1052 
1053 		/* copy args to in6_aliasreq, perform ioctl(SIOCAIFADDR_IN6). */
1054 		bzero(&ifra, sizeof(ifra));
1055 		bcopy(iflr->iflr_name, ifra.ifra_name,
1056 			sizeof(ifra.ifra_name));
1057 
1058 		bcopy(&iflr->addr, &ifra.ifra_addr,
1059 			((struct sockaddr *)&iflr->addr)->sa_len);
1060 		if (hostid) {
1061 			/* fill in hostid part */
1062 			ifra.ifra_addr.sin6_addr.s6_addr32[2] =
1063 				hostid->s6_addr32[2];
1064 			ifra.ifra_addr.sin6_addr.s6_addr32[3] =
1065 				hostid->s6_addr32[3];
1066 		}
1067 
1068 		if (((struct sockaddr *)&iflr->dstaddr)->sa_family) { /* XXX */
1069 			bcopy(&iflr->dstaddr, &ifra.ifra_dstaddr,
1070 				((struct sockaddr *)&iflr->dstaddr)->sa_len);
1071 			if (hostid) {
1072 				ifra.ifra_dstaddr.sin6_addr.s6_addr32[2] =
1073 					hostid->s6_addr32[2];
1074 				ifra.ifra_dstaddr.sin6_addr.s6_addr32[3] =
1075 					hostid->s6_addr32[3];
1076 			}
1077 		}
1078 
1079 		ifra.ifra_prefixmask.sin6_family = AF_INET6;
1080 		ifra.ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6);
1081 		in6_len2mask(&ifra.ifra_prefixmask.sin6_addr, prefixlen);
1082 
1083 		ifra.ifra_flags = iflr->flags & ~IFLR_PREFIX;
1084 		return in6_control(so, SIOCAIFADDR_IN6, (caddr_t)&ifra, ifp, p);
1085 	    }
1086 	case SIOCGLIFADDR:
1087 	case SIOCDLIFADDR:
1088 	    {
1089 		struct in6_ifaddr *ia;
1090 		struct in6_addr mask, candidate, match;
1091 		struct sockaddr_in6 *sin6;
1092 		int cmp;
1093 
1094 		bzero(&mask, sizeof(mask));
1095 		if (iflr->flags & IFLR_PREFIX) {
1096 			/* lookup a prefix rather than address. */
1097 			in6_len2mask(&mask, iflr->prefixlen);
1098 
1099 			sin6 = (struct sockaddr_in6 *)&iflr->addr;
1100 			bcopy(&sin6->sin6_addr, &match, sizeof(match));
1101 			match.s6_addr32[0] &= mask.s6_addr32[0];
1102 			match.s6_addr32[1] &= mask.s6_addr32[1];
1103 			match.s6_addr32[2] &= mask.s6_addr32[2];
1104 			match.s6_addr32[3] &= mask.s6_addr32[3];
1105 
1106 			/* if you set extra bits, that's wrong */
1107 			if (bcmp(&match, &sin6->sin6_addr, sizeof(match)))
1108 				return EINVAL;
1109 
1110 			cmp = 1;
1111 		} else {
1112 			if (cmd == SIOCGLIFADDR) {
1113 				/* on getting an address, take the 1st match */
1114 				cmp = 0;	/* XXX */
1115 			} else {
1116 				/* on deleting an address, do exact match */
1117 				in6_len2mask(&mask, 128);
1118 				sin6 = (struct sockaddr_in6 *)&iflr->addr;
1119 				bcopy(&sin6->sin6_addr, &match, sizeof(match));
1120 
1121 				cmp = 1;
1122 			}
1123 		}
1124 
1125 		for (ifa = ifp->if_addrlist.tqh_first;
1126 		     ifa;
1127 		     ifa = ifa->ifa_list.tqe_next)
1128 		{
1129 			if (ifa->ifa_addr->sa_family != AF_INET6)
1130 				continue;
1131 			if (!cmp)
1132 				break;
1133 			bcopy(IFA_IN6(ifa), &candidate, sizeof(candidate));
1134 			candidate.s6_addr32[0] &= mask.s6_addr32[0];
1135 			candidate.s6_addr32[1] &= mask.s6_addr32[1];
1136 			candidate.s6_addr32[2] &= mask.s6_addr32[2];
1137 			candidate.s6_addr32[3] &= mask.s6_addr32[3];
1138 			if (IN6_ARE_ADDR_EQUAL(&candidate, &match))
1139 				break;
1140 		}
1141 		if (!ifa)
1142 			return EADDRNOTAVAIL;
1143 		ia = ifa2ia6(ifa);
1144 
1145 		if (cmd == SIOCGLIFADDR) {
1146 			/* fill in the if_laddrreq structure */
1147 			bcopy(&ia->ia_addr, &iflr->addr, ia->ia_addr.sin6_len);
1148 
1149 			if ((ifp->if_flags & IFF_POINTOPOINT) != 0) {
1150 				bcopy(&ia->ia_dstaddr, &iflr->dstaddr,
1151 					ia->ia_dstaddr.sin6_len);
1152 			} else
1153 				bzero(&iflr->dstaddr, sizeof(iflr->dstaddr));
1154 
1155 			iflr->prefixlen =
1156 				in6_mask2len(&ia->ia_prefixmask.sin6_addr);
1157 
1158 			iflr->flags = ia->ia6_flags;	/* XXX */
1159 
1160 			return 0;
1161 		} else {
1162 			struct in6_aliasreq ifra;
1163 
1164 			/* fill in6_aliasreq and do ioctl(SIOCDIFADDR_IN6) */
1165 			bzero(&ifra, sizeof(ifra));
1166 			bcopy(iflr->iflr_name, ifra.ifra_name,
1167 				sizeof(ifra.ifra_name));
1168 
1169 			bcopy(&ia->ia_addr, &ifra.ifra_addr,
1170 				ia->ia_addr.sin6_len);
1171 			if ((ifp->if_flags & IFF_POINTOPOINT) != 0) {
1172 				bcopy(&ia->ia_dstaddr, &ifra.ifra_dstaddr,
1173 					ia->ia_dstaddr.sin6_len);
1174 			} else {
1175 				bzero(&ifra.ifra_dstaddr,
1176 				    sizeof(ifra.ifra_dstaddr));
1177 			}
1178 			bcopy(&ia->ia_prefixmask, &ifra.ifra_dstaddr,
1179 				ia->ia_prefixmask.sin6_len);
1180 
1181 			ifra.ifra_flags = ia->ia6_flags;
1182 			return in6_control(so, SIOCDIFADDR_IN6, (caddr_t)&ifra,
1183 				ifp, p);
1184 		}
1185 	    }
1186 	}
1187 
1188 	return EOPNOTSUPP;	/* just for safety */
1189 }
1190 
1191 /*
1192  * Delete any existing route for an interface.
1193  */
1194 void
1195 in6_ifscrub(ifp, ia)
1196 	struct ifnet *ifp;
1197 	struct in6_ifaddr *ia;
1198 {
1199 	if ((ia->ia_flags & IFA_ROUTE) == 0)
1200 		return;
1201 
1202 	/*
1203 	 * We should check the existence of dstaddr, because link-local
1204 	 * addresses can be configured without particular destinations
1205 	 * even on point-to-point or loopback interfaces.
1206 	 * In this case, kernel would panic in rtinit()...
1207 	 */
1208 	if (ifp->if_flags & (IFF_LOOPBACK | IFF_POINTOPOINT) &&
1209 	    (ia->ia_ifa.ifa_dstaddr != NULL))
1210 		rtinit(&(ia->ia_ifa), (int)RTM_DELETE, RTF_HOST);
1211 	else
1212 		rtinit(&(ia->ia_ifa), (int)RTM_DELETE, 0);
1213 	ia->ia_flags &= ~IFA_ROUTE;
1214 
1215 	/* Remove ownaddr's loopback rtentry, if it exists. */
1216 	in6_ifremloop(&(ia->ia_ifa));
1217 }
1218 
1219 /*
1220  * Initialize an interface's intetnet6 address
1221  * and routing table entry.
1222  */
1223 static int
1224 in6_ifinit(ifp, ia, sin6, scrub)
1225 	struct ifnet *ifp;
1226 	struct in6_ifaddr *ia;
1227 	struct sockaddr_in6 *sin6;
1228 	int scrub;
1229 {
1230 	struct	sockaddr_in6 oldaddr;
1231 	int	error, flags = RTF_UP;
1232 	int	s = splnet();
1233 
1234 	oldaddr = ia->ia_addr;
1235 	ia->ia_addr = *sin6;
1236 	/*
1237 	 * Give the interface a chance to initialize
1238 	 * if this is its first address,
1239 	 * and to validate the address if necessary.
1240 	 */
1241 	if (ifp->if_ioctl &&
1242 	   (error = (*ifp->if_ioctl)(ifp, SIOCSIFADDR, (caddr_t)ia))) {
1243 		splx(s);
1244 		ia->ia_addr = oldaddr;
1245 		return(error);
1246 	}
1247 
1248 	switch (ifp->if_type) {
1249 	case IFT_ARCNET:
1250 	case IFT_ETHER:
1251 	case IFT_FDDI:
1252 	case IFT_IEEE1394:
1253 		ia->ia_ifa.ifa_rtrequest = nd6_rtrequest;
1254 		ia->ia_ifa.ifa_flags |= RTF_CLONING;
1255 		break;
1256 	case IFT_PPP:
1257 		ia->ia_ifa.ifa_rtrequest = nd6_p2p_rtrequest;
1258 		ia->ia_ifa.ifa_flags |= RTF_CLONING;
1259 		break;
1260 	}
1261 
1262 	splx(s);
1263 	if (scrub) {
1264 		ia->ia_ifa.ifa_addr = (struct sockaddr *)&oldaddr;
1265 		in6_ifscrub(ifp, ia);
1266 		ia->ia_ifa.ifa_addr = (struct sockaddr *)&ia->ia_addr;
1267 	}
1268 	/* xxx
1269 	 * in_socktrim
1270 	 */
1271 	/*
1272 	 * Add route for the network.
1273 	 */
1274 	ia->ia_ifa.ifa_metric = ifp->if_metric;
1275 	if (ifp->if_flags & IFF_LOOPBACK) {
1276 		ia->ia_ifa.ifa_dstaddr = ia->ia_ifa.ifa_addr;
1277 		flags |= RTF_HOST;
1278 	} else if (ifp->if_flags & IFF_POINTOPOINT) {
1279 		if (ia->ia_dstaddr.sin6_family != AF_INET6)
1280 			return(0);
1281 		flags |= RTF_HOST;
1282 	}
1283 	if ((error = rtinit(&(ia->ia_ifa), (int)RTM_ADD, flags)) == 0)
1284 		ia->ia_flags |= IFA_ROUTE;
1285 	/* XXX check if the subnet route points to the same interface */
1286 	if (error == EEXIST)
1287 		error = 0;
1288 
1289 	/* Add ownaddr as loopback rtentry, if necessary(ex. on p2p link). */
1290 	in6_ifaddloop(&(ia->ia_ifa));
1291 
1292 	if (ifp->if_flags & IFF_MULTICAST)
1293 		in6_restoremkludge(ia, ifp);
1294 
1295 	return(error);
1296 }
1297 
1298 /*
1299  * Multicast address kludge:
1300  * If there were any multicast addresses attached to this interface address,
1301  * either move them to another address on this interface, or save them until
1302  * such time as this interface is reconfigured for IPv6.
1303  */
1304 void
1305 in6_savemkludge(oia)
1306 	struct in6_ifaddr *oia;
1307 {
1308 	struct in6_ifaddr *ia;
1309 	struct in6_multi *in6m, *next;
1310 
1311 	IFP_TO_IA6(oia->ia_ifp, ia);
1312 	if (ia) {	/* there is another address */
1313 		for (in6m = oia->ia6_multiaddrs.lh_first; in6m; in6m = next){
1314 			next = in6m->in6m_entry.le_next;
1315 			IFAFREE(&in6m->in6m_ia->ia_ifa);
1316 			IFAREF(&ia->ia_ifa);
1317 			in6m->in6m_ia = ia;
1318 			LIST_INSERT_HEAD(&ia->ia6_multiaddrs, in6m, in6m_entry);
1319 		}
1320 	} else {	/* last address on this if deleted, save */
1321 		struct multi6_kludge *mk;
1322 
1323 		for (mk = in6_mk.lh_first; mk; mk = mk->mk_entry.le_next) {
1324 			if (mk->mk_ifp == oia->ia_ifp)
1325 				break;
1326 		}
1327 		if (mk == NULL) /* this should not happen! */
1328 			panic("in6_savemkludge: no kludge space");
1329 
1330 		for (in6m = oia->ia6_multiaddrs.lh_first; in6m; in6m = next){
1331 			next = in6m->in6m_entry.le_next;
1332 			IFAFREE(&in6m->in6m_ia->ia_ifa); /* release reference */
1333 			in6m->in6m_ia = NULL;
1334 			LIST_INSERT_HEAD(&mk->mk_head, in6m, in6m_entry);
1335 		}
1336 	}
1337 }
1338 
1339 /*
1340  * Continuation of multicast address hack:
1341  * If there was a multicast group list previously saved for this interface,
1342  * then we re-attach it to the first address configured on the i/f.
1343  */
1344 void
1345 in6_restoremkludge(ia, ifp)
1346 	struct in6_ifaddr *ia;
1347 	struct ifnet *ifp;
1348 {
1349 	struct multi6_kludge *mk;
1350 
1351 	for (mk = in6_mk.lh_first; mk; mk = mk->mk_entry.le_next) {
1352 		if (mk->mk_ifp == ifp) {
1353 			struct in6_multi *in6m, *next;
1354 
1355 			for (in6m = mk->mk_head.lh_first; in6m; in6m = next) {
1356 				next = in6m->in6m_entry.le_next;
1357 				in6m->in6m_ia = ia;
1358 				IFAREF(&ia->ia_ifa);
1359 				LIST_INSERT_HEAD(&ia->ia6_multiaddrs,
1360 						 in6m, in6m_entry);
1361 			}
1362 			LIST_INIT(&mk->mk_head);
1363 			break;
1364 		}
1365 	}
1366 }
1367 
1368 /*
1369  * Allocate space for the kludge at interface initialization time.
1370  * Formerly, we dynamically allocated the space in in6_savemkludge() with
1371  * malloc(M_WAITOK).  However, it was wrong since the function could be called
1372  * under an interrupt context (software timer on address lifetime expiration).
1373  * Also, we cannot just give up allocating the strucutre, since the group
1374  * membership structure is very complex and we need to keep it anyway.
1375  * Of course, this function MUST NOT be called under an interrupt context.
1376  * Specifically, it is expected to be called only from in6_ifattach(), though
1377  * it is a global function.
1378  */
1379 void
1380 in6_createmkludge(ifp)
1381 	struct ifnet *ifp;
1382 {
1383 	struct multi6_kludge *mk;
1384 
1385 	for (mk = in6_mk.lh_first; mk; mk = mk->mk_entry.le_next) {
1386 		/* If we've already had one, do not allocate. */
1387 		if (mk->mk_ifp == ifp)
1388 			return;
1389 	}
1390 
1391 	mk = malloc(sizeof(*mk), M_IPMADDR, M_WAITOK);
1392 
1393 	bzero(mk, sizeof(*mk));
1394 	LIST_INIT(&mk->mk_head);
1395 	mk->mk_ifp = ifp;
1396 	LIST_INSERT_HEAD(&in6_mk, mk, mk_entry);
1397 }
1398 
1399 void
1400 in6_purgemkludge(ifp)
1401 	struct ifnet *ifp;
1402 {
1403 	struct multi6_kludge *mk;
1404 	struct in6_multi *in6m;
1405 
1406 	for (mk = in6_mk.lh_first; mk; mk = mk->mk_entry.le_next) {
1407 		if (mk->mk_ifp != ifp)
1408 			continue;
1409 
1410 		/* leave from all multicast groups joined */
1411 		while ((in6m = LIST_FIRST(&mk->mk_head)) != NULL)
1412 			in6_delmulti(in6m);
1413 		LIST_REMOVE(mk, mk_entry);
1414 		free(mk, M_IPMADDR);
1415 		break;
1416 	}
1417 }
1418 
1419 /*
1420  * Add an address to the list of IP6 multicast addresses for a
1421  * given interface.
1422  */
1423 struct	in6_multi *
1424 in6_addmulti(maddr6, ifp, errorp)
1425 	struct in6_addr *maddr6;
1426 	struct ifnet *ifp;
1427 	int *errorp;
1428 {
1429 	struct	in6_ifaddr *ia;
1430 	struct	in6_ifreq ifr;
1431 	struct	in6_multi *in6m;
1432 	int	s = splsoftnet();
1433 
1434 	*errorp = 0;
1435 	/*
1436 	 * See if address already in list.
1437 	 */
1438 	IN6_LOOKUP_MULTI(*maddr6, ifp, in6m);
1439 	if (in6m != NULL) {
1440 		/*
1441 		 * Found it; just increment the refrence count.
1442 		 */
1443 		in6m->in6m_refcount++;
1444 	} else {
1445 		/*
1446 		 * New address; allocate a new multicast record
1447 		 * and link it into the interface's multicast list.
1448 		 */
1449 		in6m = (struct in6_multi *)
1450 			malloc(sizeof(*in6m), M_IPMADDR, M_NOWAIT);
1451 		if (in6m == NULL) {
1452 			splx(s);
1453 			*errorp = ENOBUFS;
1454 			return(NULL);
1455 		}
1456 		in6m->in6m_addr = *maddr6;
1457 		in6m->in6m_ifp = ifp;
1458 		in6m->in6m_refcount = 1;
1459 		IFP_TO_IA6(ifp, ia);
1460 		if (ia == NULL) {
1461 			free(in6m, M_IPMADDR);
1462 			splx(s);
1463 			*errorp = EADDRNOTAVAIL; /* appropriate? */
1464 			return(NULL);
1465 		}
1466 		in6m->in6m_ia = ia;
1467 		IFAREF(&ia->ia_ifa); /* gain a reference */
1468 		LIST_INSERT_HEAD(&ia->ia6_multiaddrs, in6m, in6m_entry);
1469 
1470 		/*
1471 		 * Ask the network driver to update its multicast reception
1472 		 * filter appropriately for the new address.
1473 		 */
1474 		bzero(&ifr.ifr_addr, sizeof(struct sockaddr_in6));
1475 		ifr.ifr_addr.sin6_len = sizeof(struct sockaddr_in6);
1476 		ifr.ifr_addr.sin6_family = AF_INET6;
1477 		ifr.ifr_addr.sin6_addr = *maddr6;
1478 		if (ifp->if_ioctl == NULL)
1479 			*errorp = ENXIO; /* XXX: appropriate? */
1480 		else
1481 			*errorp = (*ifp->if_ioctl)(ifp, SIOCADDMULTI,
1482 						    (caddr_t)&ifr);
1483 		if (*errorp) {
1484 			LIST_REMOVE(in6m, in6m_entry);
1485 			free(in6m, M_IPMADDR);
1486 			IFAFREE(&ia->ia_ifa);
1487 			splx(s);
1488 			return(NULL);
1489 		}
1490 		/*
1491 		 * Let MLD6 know that we have joined a new IP6 multicast
1492 		 * group.
1493 		 */
1494 		mld6_start_listening(in6m);
1495 	}
1496 	splx(s);
1497 	return(in6m);
1498 }
1499 
1500 /*
1501  * Delete a multicast address record.
1502  */
1503 void
1504 in6_delmulti(in6m)
1505 	struct in6_multi *in6m;
1506 {
1507 	struct	in6_ifreq ifr;
1508 	int	s = splsoftnet();
1509 
1510 	if (--in6m->in6m_refcount == 0) {
1511 		/*
1512 		 * No remaining claims to this record; let MLD6 know
1513 		 * that we are leaving the multicast group.
1514 		 */
1515 		mld6_stop_listening(in6m);
1516 
1517 		/*
1518 		 * Unlink from list.
1519 		 */
1520 		LIST_REMOVE(in6m, in6m_entry);
1521 		if (in6m->in6m_ia) {
1522 			IFAFREE(&in6m->in6m_ia->ia_ifa); /* release reference */
1523 		}
1524 
1525 		/*
1526 		 * Notify the network driver to update its multicast
1527 		 * reception filter.
1528 		 */
1529 		bzero(&ifr.ifr_addr, sizeof(struct sockaddr_in6));
1530 		ifr.ifr_addr.sin6_len = sizeof(struct sockaddr_in6);
1531 		ifr.ifr_addr.sin6_family = AF_INET6;
1532 		ifr.ifr_addr.sin6_addr = in6m->in6m_addr;
1533 		(*in6m->in6m_ifp->if_ioctl)(in6m->in6m_ifp,
1534 					    SIOCDELMULTI, (caddr_t)&ifr);
1535 		free(in6m, M_IPMADDR);
1536 	}
1537 	splx(s);
1538 }
1539 
1540 struct in6_multi_mship *
1541 in6_joingroup(ifp, addr, errorp)
1542 	struct ifnet *ifp;
1543 	struct in6_addr *addr;
1544 	int *errorp;
1545 {
1546 	struct in6_multi_mship *imm;
1547 
1548 	imm = malloc(sizeof(*imm), M_IPMADDR, M_NOWAIT);
1549 	if (!imm) {
1550 		*errorp = ENOBUFS;
1551 		return NULL;
1552 	}
1553 	imm->i6mm_maddr = in6_addmulti(addr, ifp, errorp);
1554 	if (!imm->i6mm_maddr) {
1555 		/* *errorp is alrady set */
1556 		free(imm, M_IPMADDR);
1557 		return NULL;
1558 	}
1559 	return imm;
1560 }
1561 
1562 int
1563 in6_leavegroup(imm)
1564 	struct in6_multi_mship *imm;
1565 {
1566 
1567 	if (imm->i6mm_maddr)
1568 		in6_delmulti(imm->i6mm_maddr);
1569 	free(imm,  M_IPMADDR);
1570 	return 0;
1571 }
1572 
1573 /*
1574  * Find an IPv6 interface link-local address specific to an interface.
1575  */
1576 struct in6_ifaddr *
1577 in6ifa_ifpforlinklocal(ifp, ignoreflags)
1578 	struct ifnet *ifp;
1579 	int ignoreflags;
1580 {
1581 	struct ifaddr *ifa;
1582 
1583 	for (ifa = ifp->if_addrlist.tqh_first; ifa; ifa = ifa->ifa_list.tqe_next)
1584 	{
1585 		if (ifa->ifa_addr == NULL)
1586 			continue;	/* just for safety */
1587 		if (ifa->ifa_addr->sa_family != AF_INET6)
1588 			continue;
1589 		if (IN6_IS_ADDR_LINKLOCAL(IFA_IN6(ifa))) {
1590 			if ((((struct in6_ifaddr *)ifa)->ia6_flags &
1591 			     ignoreflags) != 0)
1592 				continue;
1593 			break;
1594 		}
1595 	}
1596 
1597 	return((struct in6_ifaddr *)ifa);
1598 }
1599 
1600 
1601 /*
1602  * find the internet address corresponding to a given interface and address.
1603  */
1604 struct in6_ifaddr *
1605 in6ifa_ifpwithaddr(ifp, addr)
1606 	struct ifnet *ifp;
1607 	struct in6_addr *addr;
1608 {
1609 	struct ifaddr *ifa;
1610 
1611 	for (ifa = ifp->if_addrlist.tqh_first; ifa; ifa = ifa->ifa_list.tqe_next)
1612 	{
1613 		if (ifa->ifa_addr == NULL)
1614 			continue;	/* just for safety */
1615 		if (ifa->ifa_addr->sa_family != AF_INET6)
1616 			continue;
1617 		if (IN6_ARE_ADDR_EQUAL(addr, IFA_IN6(ifa)))
1618 			break;
1619 	}
1620 
1621 	return((struct in6_ifaddr *)ifa);
1622 }
1623 
1624 /*
1625  * Convert IP6 address to printable (loggable) representation.
1626  */
1627 static char digits[] = "0123456789abcdef";
1628 static int ip6round = 0;
1629 char *
1630 ip6_sprintf(addr)
1631 	const struct in6_addr *addr;
1632 {
1633 	static char ip6buf[8][48];
1634 	int i;
1635 	char *cp;
1636 	const u_short *a = (u_short *)addr;
1637 	const u_char *d;
1638 	int dcolon = 0;
1639 
1640 	ip6round = (ip6round + 1) & 7;
1641 	cp = ip6buf[ip6round];
1642 
1643 	for (i = 0; i < 8; i++) {
1644 		if (dcolon == 1) {
1645 			if (*a == 0) {
1646 				if (i == 7)
1647 					*cp++ = ':';
1648 				a++;
1649 				continue;
1650 			} else
1651 				dcolon = 2;
1652 		}
1653 		if (*a == 0) {
1654 			if (dcolon == 0 && *(a + 1) == 0) {
1655 				if (i == 0)
1656 					*cp++ = ':';
1657 				*cp++ = ':';
1658 				dcolon = 1;
1659 			} else {
1660 				*cp++ = '0';
1661 				*cp++ = ':';
1662 			}
1663 			a++;
1664 			continue;
1665 		}
1666 		d = (const u_char *)a;
1667 		*cp++ = digits[*d >> 4];
1668 		*cp++ = digits[*d++ & 0xf];
1669 		*cp++ = digits[*d >> 4];
1670 		*cp++ = digits[*d & 0xf];
1671 		*cp++ = ':';
1672 		a++;
1673 	}
1674 	*--cp = 0;
1675 	return(ip6buf[ip6round]);
1676 }
1677 
1678 int
1679 in6_localaddr(in6)
1680 	struct in6_addr *in6;
1681 {
1682 	struct in6_ifaddr *ia;
1683 
1684 	if (IN6_IS_ADDR_LOOPBACK(in6) || IN6_IS_ADDR_LINKLOCAL(in6))
1685 		return 1;
1686 
1687 	for (ia = in6_ifaddr; ia; ia = ia->ia_next)
1688 		if (IN6_ARE_MASKED_ADDR_EQUAL(in6, &ia->ia_addr.sin6_addr,
1689 					      &ia->ia_prefixmask.sin6_addr))
1690 			return 1;
1691 
1692 	return (0);
1693 }
1694 
1695 /*
1696  * Get a scope of the address. Node-local, link-local, site-local or global.
1697  */
1698 int
1699 in6_addrscope (addr)
1700 struct in6_addr *addr;
1701 {
1702 	int scope;
1703 
1704 	if (addr->s6_addr8[0] == 0xfe) {
1705 		scope = addr->s6_addr8[1] & 0xc0;
1706 
1707 		switch (scope) {
1708 		case 0x80:
1709 			return IPV6_ADDR_SCOPE_LINKLOCAL;
1710 			break;
1711 		case 0xc0:
1712 			return IPV6_ADDR_SCOPE_SITELOCAL;
1713 			break;
1714 		default:
1715 			return IPV6_ADDR_SCOPE_GLOBAL; /* just in case */
1716 			break;
1717 		}
1718 	}
1719 
1720 
1721 	if (addr->s6_addr8[0] == 0xff) {
1722 		scope = addr->s6_addr8[1] & 0x0f;
1723 
1724 		/*
1725 		 * due to other scope such as reserved,
1726 		 * return scope doesn't work.
1727 		 */
1728 		switch (scope) {
1729 		case IPV6_ADDR_SCOPE_NODELOCAL:
1730 			return IPV6_ADDR_SCOPE_NODELOCAL;
1731 			break;
1732 		case IPV6_ADDR_SCOPE_LINKLOCAL:
1733 			return IPV6_ADDR_SCOPE_LINKLOCAL;
1734 			break;
1735 		case IPV6_ADDR_SCOPE_SITELOCAL:
1736 			return IPV6_ADDR_SCOPE_SITELOCAL;
1737 			break;
1738 		default:
1739 			return IPV6_ADDR_SCOPE_GLOBAL;
1740 			break;
1741 		}
1742 	}
1743 
1744 	if (bcmp(&in6addr_loopback, addr, sizeof(addr) - 1) == 0) {
1745 		if (addr->s6_addr8[15] == 1) /* loopback */
1746 			return IPV6_ADDR_SCOPE_NODELOCAL;
1747 		if (addr->s6_addr8[15] == 0) /* unspecified */
1748 			return IPV6_ADDR_SCOPE_LINKLOCAL;
1749 	}
1750 
1751 	return IPV6_ADDR_SCOPE_GLOBAL;
1752 }
1753 
1754 int
1755 in6_addr2scopeid(ifp, addr)
1756 	struct ifnet *ifp;	/* must not be NULL */
1757 	struct in6_addr *addr;	/* must not be NULL */
1758 {
1759 	int scope = in6_addrscope(addr);
1760 
1761 	switch (scope) {
1762 	case IPV6_ADDR_SCOPE_NODELOCAL:
1763 		return(-1);	/* XXX: is this an appropriate value? */
1764 
1765 	case IPV6_ADDR_SCOPE_LINKLOCAL:
1766 		/* XXX: we do not distinguish between a link and an I/F. */
1767 		return(ifp->if_index);
1768 
1769 	case IPV6_ADDR_SCOPE_SITELOCAL:
1770 		return(0);	/* XXX: invalid. */
1771 
1772 	default:
1773 		return(0);	/* XXX: treat as global. */
1774 	}
1775 }
1776 
1777 /*
1778  * return length of part which dst and src are equal
1779  * hard coding...
1780  */
1781 int
1782 in6_matchlen(src, dst)
1783 struct in6_addr *src, *dst;
1784 {
1785 	int match = 0;
1786 	u_char *s = (u_char *)src, *d = (u_char *)dst;
1787 	u_char *lim = s + 16, r;
1788 
1789 	while (s < lim)
1790 		if ((r = (*d++ ^ *s++)) != 0) {
1791 			while (r < 128) {
1792 				match++;
1793 				r <<= 1;
1794 			}
1795 			break;
1796 		} else
1797 			match += 8;
1798 	return match;
1799 }
1800 
1801 /* XXX: to be scope conscious */
1802 int
1803 in6_are_prefix_equal(p1, p2, len)
1804 	struct in6_addr *p1, *p2;
1805 	int len;
1806 {
1807 	int bytelen, bitlen;
1808 
1809 	/* sanity check */
1810 	if (0 > len || len > 128) {
1811 		log(LOG_ERR, "in6_are_prefix_equal: invalid prefix length(%d)\n",
1812 		    len);
1813 		return(0);
1814 	}
1815 
1816 	bytelen = len / 8;
1817 	bitlen = len % 8;
1818 
1819 	if (bcmp(&p1->s6_addr, &p2->s6_addr, bytelen))
1820 		return(0);
1821 	if (p1->s6_addr[bytelen] >> (8 - bitlen) !=
1822 	    p2->s6_addr[bytelen] >> (8 - bitlen))
1823 		return(0);
1824 
1825 	return(1);
1826 }
1827 
1828 void
1829 in6_prefixlen2mask(maskp, len)
1830 	struct in6_addr *maskp;
1831 	int len;
1832 {
1833 	u_char maskarray[8] = {0x80, 0xc0, 0xe0, 0xf0, 0xf8, 0xfc, 0xfe, 0xff};
1834 	int bytelen, bitlen, i;
1835 
1836 	/* sanity check */
1837 	if (0 > len || len > 128) {
1838 		log(LOG_ERR, "in6_prefixlen2mask: invalid prefix length(%d)\n",
1839 		    len);
1840 		return;
1841 	}
1842 
1843 	bzero(maskp, sizeof(*maskp));
1844 	bytelen = len / 8;
1845 	bitlen = len % 8;
1846 	for (i = 0; i < bytelen; i++)
1847 		maskp->s6_addr[i] = 0xff;
1848 	if (bitlen)
1849 		maskp->s6_addr[bytelen] = maskarray[bitlen - 1];
1850 }
1851 
1852 /*
1853  * return the best address out of the same scope
1854  */
1855 struct in6_ifaddr *
1856 in6_ifawithscope(oifp, dst)
1857 	struct ifnet *oifp;
1858 	struct in6_addr *dst;
1859 {
1860 	int dst_scope =	in6_addrscope(dst), src_scope, best_scope = 0;
1861 	int blen = -1;
1862 	struct ifaddr *ifa;
1863 	struct ifnet *ifp;
1864 	struct in6_ifaddr *ifa_best = NULL;
1865 
1866 	if (oifp == NULL) {
1867 		printf("in6_ifawithscope: output interface is not specified\n");
1868 		return(NULL);
1869 	}
1870 
1871 	/*
1872 	 * We search for all addresses on all interfaces from the beginning.
1873 	 * Comparing an interface with the outgoing interface will be done
1874 	 * only at the final stage of tiebreaking.
1875 	 */
1876 	for (ifp = TAILQ_FIRST(&ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list))
1877 	{
1878 		/*
1879 		 * We can never take an address that breaks the scope zone
1880 		 * of the destination.
1881 		 */
1882 		if (in6_addr2scopeid(ifp, dst) != in6_addr2scopeid(oifp, dst))
1883 			continue;
1884 
1885 		for (ifa = ifp->if_addrlist.tqh_first; ifa;
1886 		     ifa = ifa->ifa_list.tqe_next)
1887 		{
1888 			int tlen = -1, dscopecmp, bscopecmp, matchcmp;
1889 
1890 			if (ifa->ifa_addr->sa_family != AF_INET6)
1891 				continue;
1892 
1893 			src_scope = in6_addrscope(IFA_IN6(ifa));
1894 
1895 #ifdef ADDRSELECT_DEBUG		/* should be removed after stabilization */
1896 			dscopecmp = IN6_ARE_SCOPE_CMP(src_scope, dst_scope);
1897 			printf("in6_ifawithscope: dst=%s bestaddr=%s, "
1898 			       "newaddr=%s, scope=%x, dcmp=%d, bcmp=%d, "
1899 			       "matchlen=%d, flgs=%x\n",
1900 			       ip6_sprintf(dst),
1901 			       ifa_best ? ip6_sprintf(&ifa_best->ia_addr.sin6_addr) : "none",
1902 			       ip6_sprintf(IFA_IN6(ifa)), src_scope,
1903 			       dscopecmp,
1904 			       ifa_best ? IN6_ARE_SCOPE_CMP(src_scope, best_scope) : -1,
1905 			       in6_matchlen(IFA_IN6(ifa), dst),
1906 			       ((struct in6_ifaddr *)ifa)->ia6_flags);
1907 #endif
1908 
1909 			/*
1910 			 * Don't use an address before completing DAD
1911 			 * nor a duplicated address.
1912 			 */
1913 			if (((struct in6_ifaddr *)ifa)->ia6_flags &
1914 			    IN6_IFF_NOTREADY)
1915 				continue;
1916 
1917 			/* XXX: is there any case to allow anycasts? */
1918 			if (((struct in6_ifaddr *)ifa)->ia6_flags &
1919 			    IN6_IFF_ANYCAST)
1920 				continue;
1921 
1922 			if (((struct in6_ifaddr *)ifa)->ia6_flags &
1923 			    IN6_IFF_DETACHED)
1924 				continue;
1925 
1926 			/*
1927 			 * If this is the first address we find,
1928 			 * keep it anyway.
1929 			 */
1930 			if (ifa_best == NULL)
1931 				goto replace;
1932 
1933 			/*
1934 			 * ifa_best is never NULL beyond this line except
1935 			 * within the block labeled "replace".
1936 			 */
1937 
1938 			/*
1939 			 * If ifa_best has a smaller scope than dst and
1940 			 * the current address has a larger one than
1941 			 * (or equal to) dst, always replace ifa_best.
1942 			 * Also, if the current address has a smaller scope
1943 			 * than dst, ignore it unless ifa_best also has a
1944 			 * smaller scope.
1945 			 */
1946 			if (IN6_ARE_SCOPE_CMP(best_scope, dst_scope) < 0 &&
1947 			    IN6_ARE_SCOPE_CMP(src_scope, dst_scope) >= 0)
1948 				goto replace;
1949 			if (IN6_ARE_SCOPE_CMP(src_scope, dst_scope) < 0 &&
1950 			    IN6_ARE_SCOPE_CMP(best_scope, dst_scope) >= 0)
1951 				continue;
1952 
1953 			/*
1954 			 * A deprecated address SHOULD NOT be used in new
1955 			 * communications if an alternate (non-deprecated)
1956 			 * address is available and has sufficient scope.
1957 			 * RFC 2462, Section 5.5.4.
1958 			 */
1959 			if (((struct in6_ifaddr *)ifa)->ia6_flags &
1960 			    IN6_IFF_DEPRECATED) {
1961 				/*
1962 				 * Ignore any deprecated addresses if
1963 				 * specified by configuration.
1964 				 */
1965 				if (!ip6_use_deprecated)
1966 					continue;
1967 
1968 				/*
1969 				 * If we have already found a non-deprecated
1970 				 * candidate, just ignore deprecated addresses.
1971 				 */
1972 				if ((ifa_best->ia6_flags & IN6_IFF_DEPRECATED)
1973 				    == 0)
1974 					continue;
1975 			}
1976 
1977 			/*
1978 			 * A non-deprecated address is always preferred
1979 			 * to a deprecated one regardless of scopes and
1980 			 * address matching.
1981 			 */
1982 			if ((ifa_best->ia6_flags & IN6_IFF_DEPRECATED) &&
1983 			    (((struct in6_ifaddr *)ifa)->ia6_flags &
1984 			     IN6_IFF_DEPRECATED) == 0)
1985 				goto replace;
1986 
1987 			/*
1988 			 * At this point, we have two cases:
1989 			 * 1. we are looking at a non-deprecated address,
1990 			 *    and ifa_best is also non-deprecated.
1991 			 * 2. we are looking at a deprecated address,
1992 			 *    and ifa_best is also deprecated.
1993 			 * Also, we do not have to consider a case where
1994 			 * the scope of if_best is larger(smaller) than dst and
1995 			 * the scope of the current address is smaller(larger)
1996 			 * than dst. Such a case has already been covered.
1997 			 * Tiebreaking is done according to the following
1998 			 * items:
1999 			 * - the scope comparison between the address and
2000 			 *   dst (dscopecmp)
2001 			 * - the scope comparison between the address and
2002 			 *   ifa_best (bscopecmp)
2003 			 * - if the address match dst longer than ifa_best
2004 			 *   (matchcmp)
2005 			 * - if the address is on the outgoing I/F (outI/F)
2006 			 *
2007 			 * Roughly speaking, the selection policy is
2008 			 * - the most important item is scope. The same scope
2009 			 *   is best. Then search for a larger scope.
2010 			 *   Smaller scopes are the last resort.
2011 			 * - A deprecated address is chosen only when we have
2012 			 *   no address that has an enough scope, but is
2013 			 *   prefered to any addresses of smaller scopes.
2014 			 * - Longest address match against dst is considered
2015 			 *   only for addresses that has the same scope of dst.
2016 			 * - If there is no other reasons to choose one,
2017 			 *   addresses on the outgoing I/F are preferred.
2018 			 *
2019 			 * The precise decision table is as follows:
2020 			 * dscopecmp bscopecmp matchcmp outI/F | replace?
2021 			 *    !equal     equal      N/A    Yes |      Yes (1)
2022 			 *    !equal     equal      N/A     No |       No (2)
2023 			 *    larger    larger      N/A    N/A |       No (3)
2024 			 *    larger   smaller      N/A    N/A |      Yes (4)
2025 			 *   smaller    larger      N/A    N/A |      Yes (5)
2026 			 *   smaller   smaller      N/A    N/A |       No (6)
2027 			 *     equal   smaller      N/A    N/A |      Yes (7)
2028 			 *     equal    larger       (already done)
2029 			 *     equal     equal   larger    N/A |      Yes (8)
2030 			 *     equal     equal  smaller    N/A |       No (9)
2031 			 *     equal     equal    equal    Yes |      Yes (a)
2032 			 *     eaual     eqaul    equal     No |       No (b)
2033 			 */
2034 			dscopecmp = IN6_ARE_SCOPE_CMP(src_scope, dst_scope);
2035 			bscopecmp = IN6_ARE_SCOPE_CMP(src_scope, best_scope);
2036 
2037 			if (dscopecmp && bscopecmp == 0) {
2038 				if (oifp == ifp) /* (1) */
2039 					goto replace;
2040 				continue; /* (2) */
2041 			}
2042 			if (dscopecmp > 0) {
2043 				if (bscopecmp > 0) /* (3) */
2044 					continue;
2045 				goto replace; /* (4) */
2046 			}
2047 			if (dscopecmp < 0) {
2048 				if (bscopecmp > 0) /* (5) */
2049 					goto replace;
2050 				continue; /* (6) */
2051 			}
2052 
2053 			/* now dscopecmp must be 0 */
2054 			if (bscopecmp < 0)
2055 				goto replace; /* (7) */
2056 
2057 			/*
2058 			 * At last both dscopecmp and bscopecmp must be 0.
2059 			 * We need address matching against dst for
2060 			 * tiebreaking.
2061 			 */
2062 			tlen = in6_matchlen(IFA_IN6(ifa), dst);
2063 			matchcmp = tlen - blen;
2064 			if (matchcmp > 0) /* (8) */
2065 				goto replace;
2066 			if (matchcmp < 0) /* (9) */
2067 				continue;
2068 			if (oifp == ifp) /* (a) */
2069 				goto replace;
2070 			continue; /* (b) */
2071 
2072 		  replace:
2073 			ifa_best = (struct in6_ifaddr *)ifa;
2074 			blen = tlen >= 0 ? tlen :
2075 				in6_matchlen(IFA_IN6(ifa), dst);
2076 			best_scope = in6_addrscope(&ifa_best->ia_addr.sin6_addr);
2077 		}
2078 	}
2079 
2080 	/* count statistics for future improvements */
2081 	if (ifa_best == NULL)
2082 		ip6stat.ip6s_sources_none++;
2083 	else {
2084 		if (oifp == ifa_best->ia_ifp)
2085 			ip6stat.ip6s_sources_sameif[best_scope]++;
2086 		else
2087 			ip6stat.ip6s_sources_otherif[best_scope]++;
2088 
2089 		if (best_scope == dst_scope)
2090 			ip6stat.ip6s_sources_samescope[best_scope]++;
2091 		else
2092 			ip6stat.ip6s_sources_otherscope[best_scope]++;
2093 
2094 		if ((ifa_best->ia6_flags & IN6_IFF_DEPRECATED) != 0)
2095 			ip6stat.ip6s_sources_deprecated[best_scope]++;
2096 	}
2097 
2098 	return(ifa_best);
2099 }
2100 
2101 /*
2102  * return the best address out of the same scope. if no address was
2103  * found, return the first valid address from designated IF.
2104  */
2105 struct in6_ifaddr *
2106 in6_ifawithifp(ifp, dst)
2107 	struct ifnet *ifp;
2108 	struct in6_addr *dst;
2109 {
2110 	int dst_scope =	in6_addrscope(dst), blen = -1, tlen;
2111 	struct ifaddr *ifa;
2112 	struct in6_ifaddr *besta = 0;
2113 	struct in6_ifaddr *dep[2];	/* last-resort: deprecated */
2114 
2115 	dep[0] = dep[1] = NULL;
2116 
2117 	/*
2118 	 * We first look for addresses in the same scope.
2119 	 * If there is one, return it.
2120 	 * If two or more, return one which matches the dst longest.
2121 	 * If none, return one of global addresses assigned other ifs.
2122 	 */
2123 	for (ifa = ifp->if_addrlist.tqh_first; ifa; ifa = ifa->ifa_list.tqe_next)
2124 	{
2125 		if (ifa->ifa_addr->sa_family != AF_INET6)
2126 			continue;
2127 		if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST)
2128 			continue; /* XXX: is there any case to allow anycast? */
2129 		if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_NOTREADY)
2130 			continue; /* don't use this interface */
2131 		if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DETACHED)
2132 			continue;
2133 		if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DEPRECATED) {
2134 			if (ip6_use_deprecated)
2135 				dep[0] = (struct in6_ifaddr *)ifa;
2136 			continue;
2137 		}
2138 
2139 		if (dst_scope == in6_addrscope(IFA_IN6(ifa))) {
2140 			/*
2141 			 * call in6_matchlen() as few as possible
2142 			 */
2143 			if (besta) {
2144 				if (blen == -1)
2145 					blen = in6_matchlen(&besta->ia_addr.sin6_addr, dst);
2146 				tlen = in6_matchlen(IFA_IN6(ifa), dst);
2147 				if (tlen > blen) {
2148 					blen = tlen;
2149 					besta = (struct in6_ifaddr *)ifa;
2150 				}
2151 			} else
2152 				besta = (struct in6_ifaddr *)ifa;
2153 		}
2154 	}
2155 	if (besta)
2156 		return(besta);
2157 
2158 	for (ifa = ifp->if_addrlist.tqh_first; ifa; ifa = ifa->ifa_list.tqe_next)
2159 	{
2160 		if (ifa->ifa_addr->sa_family != AF_INET6)
2161 			continue;
2162 		if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST)
2163 			continue; /* XXX: is there any case to allow anycast? */
2164 		if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_NOTREADY)
2165 			continue; /* don't use this interface */
2166 		if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DETACHED)
2167 			continue;
2168 		if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DEPRECATED) {
2169 			if (ip6_use_deprecated)
2170 				dep[1] = (struct in6_ifaddr *)ifa;
2171 			continue;
2172 		}
2173 
2174 		return (struct in6_ifaddr *)ifa;
2175 	}
2176 
2177 	/* use the last-resort values, that are, deprecated addresses */
2178 	if (dep[0])
2179 		return dep[0];
2180 	if (dep[1])
2181 		return dep[1];
2182 
2183 	return NULL;
2184 }
2185 
2186 /*
2187  * perform DAD when interface becomes IFF_UP.
2188  */
2189 void
2190 in6_if_up(ifp)
2191 	struct ifnet *ifp;
2192 {
2193 	struct ifaddr *ifa;
2194 	struct in6_ifaddr *ia;
2195 	int dad_delay;		/* delay ticks before DAD output */
2196 
2197 	/*
2198 	 * special cases, like 6to4, are handled in in6_ifattach
2199 	 */
2200 	in6_ifattach(ifp, NULL);
2201 
2202 	dad_delay = 0;
2203 	for (ifa = ifp->if_addrlist.tqh_first; ifa; ifa = ifa->ifa_list.tqe_next)
2204 	{
2205 		if (ifa->ifa_addr->sa_family != AF_INET6)
2206 			continue;
2207 		ia = (struct in6_ifaddr *)ifa;
2208 		if (ia->ia6_flags & IN6_IFF_TENTATIVE)
2209 			nd6_dad_start(ifa, &dad_delay);
2210 	}
2211 }
2212 
2213 /*
2214  * Calculate max IPv6 MTU through all the interfaces and store it
2215  * to in6_maxmtu.
2216  */
2217 void
2218 in6_setmaxmtu()
2219 {
2220 	unsigned long maxmtu = 0;
2221 	struct ifnet *ifp;
2222 
2223 	for (ifp = TAILQ_FIRST(&ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list))
2224 	{
2225 		if ((ifp->if_flags & IFF_LOOPBACK) == 0 &&
2226 		    nd_ifinfo[ifp->if_index].linkmtu > maxmtu)
2227 			maxmtu =  nd_ifinfo[ifp->if_index].linkmtu;
2228 	}
2229 	if (maxmtu)	/* update only when maxmtu is positive */
2230 		in6_maxmtu = maxmtu;
2231 }
2232