xref: /dragonfly/sys/netinet6/nd6_rtr.c (revision c69bf40f)
1 /*	$FreeBSD: src/sys/netinet6/nd6_rtr.c,v 1.2.2.5 2003/04/05 10:28:53 ume Exp $	*/
2 /*	$KAME: nd6_rtr.c,v 1.111 2001/04/27 01:37:15 jinmei Exp $	*/
3 
4 /*
5  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the project nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 #include "opt_inet.h"
34 #include "opt_inet6.h"
35 
36 #include <sys/param.h>
37 #include <sys/systm.h>
38 #include <sys/malloc.h>
39 #include <sys/mbuf.h>
40 #include <sys/socket.h>
41 #include <sys/sockio.h>
42 #include <sys/time.h>
43 #include <sys/kernel.h>
44 #include <sys/errno.h>
45 #include <sys/syslog.h>
46 #include <sys/queue.h>
47 #include <sys/globaldata.h>
48 #include <sys/mutex.h>
49 
50 #include <sys/thread2.h>
51 #include <sys/mutex2.h>
52 
53 #include <net/if.h>
54 #include <net/if_types.h>
55 #include <net/if_dl.h>
56 #include <net/route.h>
57 #include <net/radix.h>
58 
59 #include <netinet/in.h>
60 #include <netinet6/in6_var.h>
61 #include <netinet6/in6_ifattach.h>
62 #include <netinet/ip6.h>
63 #include <netinet6/ip6_var.h>
64 #include <netinet6/nd6.h>
65 #include <netinet/icmp6.h>
66 #include <netinet6/scope6_var.h>
67 
68 #include <net/net_osdep.h>
69 
70 #define SDL(s)	((struct sockaddr_dl *)s)
71 
72 static struct nd_defrouter *defrtrlist_update (struct nd_defrouter *);
73 static struct in6_ifaddr *in6_ifadd (struct nd_prefix *,
74 	struct in6_addr *);
75 static struct nd_pfxrouter *pfxrtr_lookup (struct nd_prefix *,
76 	struct nd_defrouter *);
77 static void pfxrtr_add (struct nd_prefix *, struct nd_defrouter *);
78 static void pfxrtr_del (struct nd_pfxrouter *);
79 static struct nd_pfxrouter *find_pfxlist_reachable_router
80 	(struct nd_prefix *);
81 static void defrouter_addifreq (struct ifnet *);
82 
83 static void in6_init_address_ltimes(struct nd_prefix *ndpr,
84 	struct in6_addrlifetime *lt6);
85 
86 static int rt6_deleteroute (struct radix_node *, void *);
87 
88 extern int nd6_recalc_reachtm_interval;
89 
90 static struct ifnet *nd6_defifp;
91 int nd6_defifindex;
92 
93 int ip6_use_tempaddr = 0;
94 
95 int ip6_desync_factor;
96 u_int32_t ip6_temp_preferred_lifetime = DEF_TEMP_PREFERRED_LIFETIME;
97 u_int32_t ip6_temp_valid_lifetime = DEF_TEMP_VALID_LIFETIME;
98 /*
99  * shorter lifetimes for debugging purposes.
100 int ip6_temp_preferred_lifetime = 800;
101 static int ip6_temp_valid_lifetime = 1800;
102 */
103 int ip6_temp_regen_advance = TEMPADDR_REGEN_ADVANCE;
104 
105 /*
106  * Receive Router Solicitation Message - just for routers.
107  * Router solicitation/advertisement is mostly managed by userland program
108  * (rtadvd) so here we have no function like nd6_ra_output().
109  *
110  * Based on RFC 2461
111  */
112 void
113 nd6_rs_input(struct mbuf *m, int off, int icmp6len)
114 {
115 	struct ifnet *ifp = m->m_pkthdr.rcvif;
116 	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
117 	struct nd_router_solicit *nd_rs;
118 	struct in6_addr saddr6 = ip6->ip6_src;
119 	char *lladdr = NULL;
120 	int lladdrlen = 0;
121 #if 0
122 	struct sockaddr_dl *sdl = NULL;
123 	struct llinfo_nd6 *ln = NULL;
124 	struct rtentry *rt = NULL;
125 	int is_newentry;
126 #endif
127 	union nd_opts ndopts;
128 
129 	/* If I'm not a router, ignore it. */
130 	if (ip6_accept_rtadv != 0 || ip6_forwarding != 1)
131 		goto freeit;
132 
133 	/* Sanity checks */
134 	if (ip6->ip6_hlim != 255) {
135 		nd6log((LOG_ERR,
136 		    "nd6_rs_input: invalid hlim (%d) from %s to %s on %s\n",
137 		    ip6->ip6_hlim, ip6_sprintf(&ip6->ip6_src),
138 		    ip6_sprintf(&ip6->ip6_dst), if_name(ifp)));
139 		goto bad;
140 	}
141 
142 	/*
143 	 * Don't update the neighbor cache, if src = ::.
144 	 * This indicates that the src has no IP address assigned yet.
145 	 */
146 	if (IN6_IS_ADDR_UNSPECIFIED(&saddr6))
147 		goto freeit;
148 
149 #ifndef PULLDOWN_TEST
150 	IP6_EXTHDR_CHECK(m, off, icmp6len,);
151 	nd_rs = (struct nd_router_solicit *)((caddr_t)ip6 + off);
152 #else
153 	IP6_EXTHDR_GET(nd_rs, struct nd_router_solicit *, m, off, icmp6len);
154 	if (nd_rs == NULL) {
155 		icmp6stat.icp6s_tooshort++;
156 		return;
157 	}
158 #endif
159 
160 	icmp6len -= sizeof(*nd_rs);
161 	nd6_option_init(nd_rs + 1, icmp6len, &ndopts);
162 	if (nd6_options(&ndopts) < 0) {
163 		nd6log((LOG_INFO,
164 		    "nd6_rs_input: invalid ND option, ignored\n"));
165 		/* nd6_options have incremented stats */
166 		goto freeit;
167 	}
168 
169 	if (ndopts.nd_opts_src_lladdr) {
170 		lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1);
171 		lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3;
172 	}
173 
174 	if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
175 		nd6log((LOG_INFO,
176 		    "nd6_rs_input: lladdrlen mismatch for %s "
177 		    "(if %d, RS packet %d)\n",
178 		    ip6_sprintf(&saddr6), ifp->if_addrlen, lladdrlen - 2));
179 		goto bad;
180 	}
181 
182 	nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, ND_ROUTER_SOLICIT, 0);
183 
184 freeit:
185 	m_freem(m);
186 	return;
187 
188 bad:
189 	icmp6stat.icp6s_badrs++;
190 	m_freem(m);
191 }
192 
193 /*
194  * Receive Router Advertisement Message.
195  *
196  * Based on RFC 2461
197  * TODO: on-link bit on prefix information
198  * TODO: ND_RA_FLAG_{OTHER,MANAGED} processing
199  */
200 void
201 nd6_ra_input(struct mbuf *m, int off, int icmp6len)
202 {
203 	struct ifnet *ifp = m->m_pkthdr.rcvif;
204 	struct nd_ifinfo *ndi = ND_IFINFO(ifp);
205 	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
206 	struct nd_router_advert *nd_ra;
207 	struct in6_addr saddr6 = ip6->ip6_src;
208 #if 0
209 	struct in6_addr daddr6 = ip6->ip6_dst;
210 	int flags; /* = nd_ra->nd_ra_flags_reserved; */
211 	int is_managed = ((flags & ND_RA_FLAG_MANAGED) != 0);
212 	int is_other = ((flags & ND_RA_FLAG_OTHER) != 0);
213 #endif
214 	union nd_opts ndopts;
215 	struct nd_defrouter *dr;
216 
217 	/*
218 	 * We only accept RAs only when
219 	 * the system-wide variable allows the acceptance, and
220 	 * per-interface variable allows RAs on the receiving interface.
221 	 */
222 	if (ip6_accept_rtadv == 0)
223 		goto freeit;
224 	if (!(ndi->flags & ND6_IFF_ACCEPT_RTADV))
225 		goto freeit;
226 
227 	if (ip6->ip6_hlim != 255) {
228 		nd6log((LOG_ERR,
229 		    "nd6_ra_input: invalid hlim (%d) from %s to %s on %s\n",
230 		    ip6->ip6_hlim, ip6_sprintf(&ip6->ip6_src),
231 		    ip6_sprintf(&ip6->ip6_dst), if_name(ifp)));
232 		goto bad;
233 	}
234 
235 	if (!IN6_IS_ADDR_LINKLOCAL(&saddr6)) {
236 		nd6log((LOG_ERR,
237 		    "nd6_ra_input: src %s is not link-local\n",
238 		    ip6_sprintf(&saddr6)));
239 		goto bad;
240 	}
241 
242 #ifndef PULLDOWN_TEST
243 	IP6_EXTHDR_CHECK(m, off, icmp6len,);
244 	nd_ra = (struct nd_router_advert *)((caddr_t)ip6 + off);
245 #else
246 	IP6_EXTHDR_GET(nd_ra, struct nd_router_advert *, m, off, icmp6len);
247 	if (nd_ra == NULL) {
248 		icmp6stat.icp6s_tooshort++;
249 		return;
250 	}
251 #endif
252 
253 	icmp6len -= sizeof(*nd_ra);
254 	nd6_option_init(nd_ra + 1, icmp6len, &ndopts);
255 	if (nd6_options(&ndopts) < 0) {
256 		nd6log((LOG_INFO,
257 		    "nd6_ra_input: invalid ND option, ignored\n"));
258 		/* nd6_options have incremented stats */
259 		goto freeit;
260 	}
261 
262     {
263 	struct nd_defrouter dr0;
264 	u_int32_t advreachable = nd_ra->nd_ra_reachable;
265 
266 	dr0.rtaddr = saddr6;
267 	dr0.flags  = nd_ra->nd_ra_flags_reserved;
268 	dr0.rtlifetime = ntohs(nd_ra->nd_ra_router_lifetime);
269 	dr0.expire = time_uptime + dr0.rtlifetime;
270 	dr0.ifp = ifp;
271 	dr0.advint = 0;		/* Mobile IPv6 */
272 	dr0.advint_expire = 0;	/* Mobile IPv6 */
273 	dr0.advints_lost = 0;	/* Mobile IPv6 */
274 	/* unspecified or not? (RFC 2461 6.3.4) */
275 	if (advreachable) {
276 		advreachable = ntohl(advreachable);
277 		if (advreachable <= MAX_REACHABLE_TIME &&
278 		    ndi->basereachable != advreachable) {
279 			ndi->basereachable = advreachable;
280 			ndi->reachable = ND_COMPUTE_RTIME(ndi->basereachable);
281 			ndi->recalctm = nd6_recalc_reachtm_interval; /* reset */
282 		}
283 	}
284 	if (nd_ra->nd_ra_retransmit)
285 		ndi->retrans = ntohl(nd_ra->nd_ra_retransmit);
286 	if (nd_ra->nd_ra_curhoplimit)
287 		ndi->chlim = nd_ra->nd_ra_curhoplimit;
288 	dr = defrtrlist_update(&dr0);
289     }
290 
291 	/*
292 	 * prefix
293 	 */
294 	if (ndopts.nd_opts_pi) {
295 		struct nd_opt_hdr *pt;
296 		struct nd_opt_prefix_info *pi = NULL;
297 		struct nd_prefix pr;
298 
299 		for (pt = (struct nd_opt_hdr *)ndopts.nd_opts_pi;
300 		     pt <= (struct nd_opt_hdr *)ndopts.nd_opts_pi_end;
301 		     pt = (struct nd_opt_hdr *)((caddr_t)pt +
302 						(pt->nd_opt_len << 3))) {
303 			if (pt->nd_opt_type != ND_OPT_PREFIX_INFORMATION)
304 				continue;
305 			pi = (struct nd_opt_prefix_info *)pt;
306 
307 			if (pi->nd_opt_pi_len != 4) {
308 				nd6log((LOG_INFO,
309 				    "nd6_ra_input: invalid option "
310 				    "len %d for prefix information option, "
311 				    "ignored\n", pi->nd_opt_pi_len));
312 				continue;
313 			}
314 
315 			if (128 < pi->nd_opt_pi_prefix_len) {
316 				nd6log((LOG_INFO,
317 				    "nd6_ra_input: invalid prefix "
318 				    "len %d for prefix information option, "
319 				    "ignored\n", pi->nd_opt_pi_prefix_len));
320 				continue;
321 			}
322 
323 			if (IN6_IS_ADDR_MULTICAST(&pi->nd_opt_pi_prefix)
324 			 || IN6_IS_ADDR_LINKLOCAL(&pi->nd_opt_pi_prefix)) {
325 				nd6log((LOG_INFO,
326 				    "nd6_ra_input: invalid prefix "
327 				    "%s, ignored\n",
328 				    ip6_sprintf(&pi->nd_opt_pi_prefix)));
329 				continue;
330 			}
331 
332 			bzero(&pr, sizeof(pr));
333 			pr.ndpr_prefix.sin6_family = AF_INET6;
334 			pr.ndpr_prefix.sin6_len = sizeof(pr.ndpr_prefix);
335 			pr.ndpr_prefix.sin6_addr = pi->nd_opt_pi_prefix;
336 			pr.ndpr_ifp = (struct ifnet *)m->m_pkthdr.rcvif;
337 
338 			pr.ndpr_raf_onlink = (pi->nd_opt_pi_flags_reserved &
339 			    ND_OPT_PI_FLAG_ONLINK) ? 1 : 0;
340 			pr.ndpr_raf_auto = (pi->nd_opt_pi_flags_reserved &
341 			    ND_OPT_PI_FLAG_AUTO) ? 1 : 0;
342 			pr.ndpr_plen = pi->nd_opt_pi_prefix_len;
343 			pr.ndpr_vltime = ntohl(pi->nd_opt_pi_valid_time);
344 			pr.ndpr_pltime = ntohl(pi->nd_opt_pi_preferred_time);
345 			if (in6_init_prefix_ltimes(&pr))
346 				continue; /* prefix lifetime init failed */
347 			prelist_update(&pr, dr, m);
348 		}
349 	}
350 
351 	/*
352 	 * MTU
353 	 */
354 	if (ndopts.nd_opts_mtu && ndopts.nd_opts_mtu->nd_opt_mtu_len == 1) {
355 		u_long mtu, maxmtu;
356 
357 		mtu = ntohl(ndopts.nd_opts_mtu->nd_opt_mtu_mtu);
358 
359 		/* lower bound */
360 		if (mtu < IPV6_MMTU) {
361 			nd6log((LOG_INFO, "nd6_ra_input: bogus mtu option "
362 			    "mtu=%ld sent from %s, ignoring\n",
363 			    mtu, ip6_sprintf(&ip6->ip6_src)));
364 			goto skip;
365 		}
366 
367 		/* upper bound */
368 		maxmtu = (ndi->maxmtu && ndi->maxmtu < ifp->if_mtu) ?
369 		    ndi->maxmtu : ifp->if_mtu;
370 		if (mtu <= maxmtu) {
371 		        int change = (ndi->linkmtu != mtu);
372 
373 		        ndi->linkmtu = mtu;
374 		        if (change) /* in6_maxmtu may change */
375 		                in6_setmaxmtu();
376 		} else {
377 			nd6log((LOG_INFO, "nd6_ra_input: bogus mtu "
378 			    "mtu=%lu sent from %s; "
379 			    "exceeds maxmtu %lu, ignoring\n",
380 			    mtu, ip6_sprintf(&ip6->ip6_src), maxmtu));
381 		}
382 	}
383 
384 skip:
385 
386 	/*
387 	 * Source link layer address
388 	 */
389     {
390 	char *lladdr = NULL;
391 	int lladdrlen = 0;
392 
393 	if (ndopts.nd_opts_src_lladdr) {
394 		lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1);
395 		lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3;
396 	}
397 
398 	if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
399 		nd6log((LOG_INFO,
400 		    "nd6_ra_input: lladdrlen mismatch for %s "
401 		    "(if %d, RA packet %d)\n",
402 		    ip6_sprintf(&saddr6), ifp->if_addrlen, lladdrlen - 2));
403 		goto bad;
404 	}
405 
406 	nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, ND_ROUTER_ADVERT, 0);
407 
408 	/*
409 	 * Installing a link-layer address might change the state of the
410 	 * router's neighbor cache, which might also affect our on-link
411 	 * detection of adveritsed prefixes.
412 	 */
413 	pfxlist_onlink_check();
414     }
415 
416 freeit:
417 	m_freem(m);
418 	return;
419 
420 bad:
421 	icmp6stat.icp6s_badra++;
422 	m_freem(m);
423 }
424 
425 /*
426  * default router list proccessing sub routines
427  */
428 
429 #if 0
430 /* tell the change to user processes watching the routing socket. */
431 static void
432 nd6_rtmsg(int cmd, struct rtentry *rt)
433 {
434 	struct rt_addrinfo info;
435 
436 	bzero((caddr_t)&info, sizeof(info));
437 	info.rti_info[RTAX_DST] = rt_key(rt);
438 	info.rti_info[RTAX_GATEWAY] = rt->rt_gateway;
439 	info.rti_info[RTAX_NETMASK] = rt_mask(rt);
440 	if (TAILQ_EMPTY(&rt->rt_ifp->if_addrheads[mycpuid])) {
441 		info.rti_info[RTAX_IFP] = NULL;
442 	} else {
443 		info.rti_info[RTAX_IFP] =
444 		(struct sockaddr *)
445 		TAILQ_FIRST(&rt->rt_ifp->if_addrheads[mycpuid])->ifa;
446 	}
447 	info.rti_info[RTAX_IFA] = rt->rt_ifa->ifa_addr;
448 
449 	rt_missmsg(cmd, &info, rt->rt_flags, 0);
450 }
451 #endif
452 
453 void
454 defrouter_addreq(struct nd_defrouter *new)
455 {
456 	struct sockaddr_in6 def, mask, gate;
457 
458 	bzero(&def, sizeof(def));
459 	bzero(&mask, sizeof(mask));
460 	bzero(&gate, sizeof(gate));
461 
462 	def.sin6_len = mask.sin6_len = gate.sin6_len =
463 	    sizeof(struct sockaddr_in6);
464 	def.sin6_family = mask.sin6_family = gate.sin6_family = AF_INET6;
465 	gate.sin6_addr = new->rtaddr;
466 
467 	rtrequest_global(RTM_ADD, (struct sockaddr *)&def,
468 	    (struct sockaddr *)&gate, (struct sockaddr *)&mask, RTF_GATEWAY);
469 	return;
470 }
471 
472 /* Add a route to a given interface as default */
473 static void
474 defrouter_addifreq(struct ifnet *ifp)
475 {
476 	struct sockaddr_in6 def, mask;
477 	struct ifaddr *ifa;
478 	int error, flags;
479 
480 	bzero(&def, sizeof(def));
481 	bzero(&mask, sizeof(mask));
482 
483 	def.sin6_len = mask.sin6_len = sizeof(struct sockaddr_in6);
484 	def.sin6_family = mask.sin6_family = AF_INET6;
485 
486 	/*
487 	 * Search for an ifaddr beloging to the specified interface.
488 	 * XXX: An IPv6 address are required to be assigned on the interface.
489 	 */
490 	if ((ifa = ifaof_ifpforaddr((struct sockaddr *)&def, ifp)) == NULL) {
491 		nd6log((LOG_ERR,	/* better error? */
492 		    "defrouter_addifreq: failed to find an ifaddr "
493 		    "to install a route to interface %s\n",
494 		    if_name(ifp)));
495 		return;
496 	}
497 
498 	flags = ifa->ifa_flags;
499 	error = rtrequest_global(RTM_ADD, (struct sockaddr *)&def,
500 	    ifa->ifa_addr, (struct sockaddr *)&mask, flags);
501 	if (error != 0) {
502 		nd6log((LOG_ERR,
503 		    "defrouter_addifreq: failed to install a route to "
504 		    "interface %s (errno = %d)\n",
505 		    if_name(ifp), error));
506 	}
507 }
508 
509 struct nd_defrouter *
510 defrouter_lookup(struct in6_addr *addr, struct ifnet *ifp)
511 {
512 	struct nd_defrouter *dr;
513 
514 	for (dr = TAILQ_FIRST(&nd_defrouter); dr;
515 	     dr = TAILQ_NEXT(dr, dr_entry)) {
516 		if (dr->ifp == ifp && IN6_ARE_ADDR_EQUAL(addr, &dr->rtaddr))
517 			return (dr);
518 	}
519 
520 	return (NULL);		/* search failed */
521 }
522 
523 void
524 defrouter_delreq(struct nd_defrouter *dr, int dofree)
525 {
526 	struct sockaddr_in6 def, mask, gate;
527 
528 	bzero(&def, sizeof(def));
529 	bzero(&mask, sizeof(mask));
530 	bzero(&gate, sizeof(gate));
531 
532 	def.sin6_len = mask.sin6_len = gate.sin6_len =
533 	    sizeof(struct sockaddr_in6);
534 	def.sin6_family = mask.sin6_family = gate.sin6_family = AF_INET6;
535 	gate.sin6_addr = dr->rtaddr;
536 
537 	rtrequest_global(RTM_DELETE, (struct sockaddr *)&def,
538 	    (struct sockaddr *)&gate, (struct sockaddr *)&mask, RTF_GATEWAY);
539 	if (dofree)		/* XXX: necessary? */
540 		kfree(dr, M_IP6NDP);
541 }
542 
543 void
544 defrtrlist_del(struct nd_defrouter *dr)
545 {
546 	struct nd_defrouter *deldr = NULL;
547 	struct nd_prefix *pr;
548 
549 	/*
550 	 * Flush all the routing table entries that use the router
551 	 * as a next hop.
552 	 */
553 	if (!ip6_forwarding && ip6_accept_rtadv) /* XXX: better condition? */
554 		rt6_flush(&dr->rtaddr, dr->ifp);
555 
556 	if (dr == TAILQ_FIRST(&nd_defrouter))
557 		deldr = dr;	/* The router is primary. */
558 
559 	TAILQ_REMOVE(&nd_defrouter, dr, dr_entry);
560 
561 	/*
562 	 * Also delete all the pointers to the router in each prefix lists.
563 	 */
564 	for (pr = nd_prefix.lh_first; pr; pr = pr->ndpr_next) {
565 		struct nd_pfxrouter *pfxrtr;
566 		if ((pfxrtr = pfxrtr_lookup(pr, dr)) != NULL)
567 			pfxrtr_del(pfxrtr);
568 	}
569 	pfxlist_onlink_check();
570 
571 	/*
572 	 * If the router is the primary one, choose a new one.
573 	 * Note that defrouter_select() will remove the current gateway
574 	 * from the routing table.
575 	 */
576 	if (deldr)
577 		defrouter_select();
578 
579 	kfree(dr, M_IP6NDP);
580 }
581 
582 /*
583  * Default Router Selection according to Section 6.3.6 of RFC 2461:
584  * 1) Routers that are reachable or probably reachable should be
585  *    preferred.
586  * 2) When no routers on the list are known to be reachable or
587  *    probably reachable, routers SHOULD be selected in a round-robin
588  *    fashion.
589  * 3) If the Default Router List is empty, assume that all
590  *    destinations are on-link.
591  */
592 void
593 defrouter_select(void)
594 {
595 	struct nd_defrouter *dr, anydr;
596 	struct rtentry *rt = NULL;
597 	struct llinfo_nd6 *ln = NULL;
598 
599 	mtx_lock(&nd6_mtx);
600 
601 	/*
602 	 * Search for a (probably) reachable router from the list.
603 	 */
604 	for (dr = TAILQ_FIRST(&nd_defrouter); dr;
605 	     dr = TAILQ_NEXT(dr, dr_entry)) {
606 		if ((rt = nd6_lookup(&dr->rtaddr, 0, dr->ifp)) &&
607 		    (ln = (struct llinfo_nd6 *)rt->rt_llinfo) &&
608 		    ND6_IS_LLINFO_PROBREACH(ln)) {
609 			/* Got it, and move it to the head */
610 			TAILQ_REMOVE(&nd_defrouter, dr, dr_entry);
611 			TAILQ_INSERT_HEAD(&nd_defrouter, dr, dr_entry);
612 			break;
613 		}
614 	}
615 
616 	if ((dr = TAILQ_FIRST(&nd_defrouter))) {
617 		/*
618 		 * De-install the previous default gateway and install
619 		 * a new one.
620 		 * Note that if there is no reachable router in the list,
621 		 * the head entry will be used anyway.
622 		 * XXX: do we have to check the current routing table entry?
623 		 */
624 		bzero(&anydr, sizeof(anydr));
625 		defrouter_delreq(&anydr, 0);
626 		defrouter_addreq(dr);
627 	}
628 	else {
629 		/*
630 		 * The Default Router List is empty, so install the default
631 		 * route to an inteface.
632 		 * XXX: The specification does not say this mechanism should
633 		 * be restricted to hosts, but this would be not useful
634 		 * (even harmful) for routers.
635 		 */
636 		if (!ip6_forwarding) {
637 			/*
638 			 * De-install the current default route
639 			 * in advance.
640 			 */
641 			bzero(&anydr, sizeof(anydr));
642 			defrouter_delreq(&anydr, 0);
643 			if (nd6_defifp) {
644 				/*
645 				 * Install a route to the default interface
646 				 * as default route.
647 				 * XXX: we enable this for host only, because
648 				 * this may override a default route installed
649 				 * a user process (e.g. routing daemon) in a
650 				 * router case.
651 				 */
652 				defrouter_addifreq(nd6_defifp);
653 			} else {
654 				nd6log((LOG_INFO, "defrouter_select: "
655 				    "there's no default router and no default"
656 				    " interface\n"));
657 			}
658 		}
659 	}
660 	mtx_unlock(&nd6_mtx);
661 	return;
662 }
663 
664 static struct nd_defrouter *
665 defrtrlist_update(struct nd_defrouter *new)
666 {
667 	struct nd_defrouter *dr, *n;
668 
669 	mtx_lock(&nd6_mtx);
670 
671 	if ((dr = defrouter_lookup(&new->rtaddr, new->ifp)) != NULL) {
672 		/* entry exists */
673 		if (new->rtlifetime == 0) {
674 			defrtrlist_del(dr);
675 			dr = NULL;
676 		} else {
677 			/* override */
678 			dr->flags = new->flags; /* xxx flag check */
679 			dr->rtlifetime = new->rtlifetime;
680 			dr->expire = new->expire;
681 		}
682 		mtx_unlock(&nd6_mtx);
683 		return (dr);
684 	}
685 
686 	/* entry does not exist */
687 	if (new->rtlifetime == 0) {
688 		mtx_unlock(&nd6_mtx);
689 		return (NULL);
690 	}
691 
692 	n = (struct nd_defrouter *)kmalloc(sizeof(*n), M_IP6NDP,
693 	    M_NOWAIT | M_ZERO);
694 	if (n == NULL) {
695 		mtx_unlock(&nd6_mtx);
696 		return (NULL);
697 	}
698 	*n = *new;
699 
700 	/*
701 	 * Insert the new router at the end of the Default Router List.
702 	 * If there is no other router, install it anyway. Otherwise,
703 	 * just continue to use the current default router.
704 	 */
705 	TAILQ_INSERT_TAIL(&nd_defrouter, n, dr_entry);
706 	if (TAILQ_FIRST(&nd_defrouter) == n)
707 		defrouter_select();
708 	mtx_unlock(&nd6_mtx);
709 	return (n);
710 }
711 
712 static struct nd_pfxrouter *
713 pfxrtr_lookup(struct nd_prefix *pr, struct nd_defrouter *dr)
714 {
715 	struct nd_pfxrouter *search;
716 
717 	for (search = pr->ndpr_advrtrs.lh_first; search; search = search->pfr_next) {
718 		if (search->router == dr)
719 			break;
720 	}
721 
722 	return (search);
723 }
724 
725 static void
726 pfxrtr_add(struct nd_prefix *pr, struct nd_defrouter *dr)
727 {
728 	struct nd_pfxrouter *new;
729 
730 	new = kmalloc(sizeof(*new), M_IP6NDP, M_INTWAIT | M_ZERO);
731 	new->router = dr;
732 
733 	LIST_INSERT_HEAD(&pr->ndpr_advrtrs, new, pfr_entry);
734 
735 	pfxlist_onlink_check();
736 }
737 
738 static void
739 pfxrtr_del(struct nd_pfxrouter *pfr)
740 {
741 	LIST_REMOVE(pfr, pfr_entry);
742 	kfree(pfr, M_IP6NDP);
743 }
744 
745 struct nd_prefix *
746 nd6_prefix_lookup(struct nd_prefix *pr)
747 {
748 	struct nd_prefix *search;
749 
750 	for (search = nd_prefix.lh_first; search; search = search->ndpr_next) {
751 		if (pr->ndpr_ifp == search->ndpr_ifp &&
752 		    pr->ndpr_plen == search->ndpr_plen &&
753 		    in6_are_prefix_equal(&pr->ndpr_prefix.sin6_addr,
754 		    &search->ndpr_prefix.sin6_addr, pr->ndpr_plen))
755 			break;
756 	}
757 
758 	return (search);
759 }
760 
761 int
762 nd6_prelist_add(struct nd_prefix *pr, struct nd_defrouter *dr,
763 		struct nd_prefix **newp)
764 {
765 	struct nd_prefix *new = NULL;
766 	int i;
767 
768 	new = kmalloc(sizeof(*new), M_IP6NDP, M_INTWAIT);
769 	*new = *pr;
770 	if (newp != NULL)
771 		*newp = new;
772 
773 	/* initialization */
774 	LIST_INIT(&new->ndpr_advrtrs);
775 	in6_prefixlen2mask(&new->ndpr_mask, new->ndpr_plen);
776 	/* make prefix in the canonical form */
777 	for (i = 0; i < 4; i++) {
778 		new->ndpr_prefix.sin6_addr.s6_addr32[i] &=
779 		    new->ndpr_mask.s6_addr32[i];
780 	}
781 
782 	mtx_lock(&nd6_mtx);
783 	/* link ndpr_entry to nd_prefix list */
784 	LIST_INSERT_HEAD(&nd_prefix, new, ndpr_entry);
785 	mtx_unlock(&nd6_mtx);
786 
787 	/* ND_OPT_PI_FLAG_ONLINK processing */
788 	if (new->ndpr_raf_onlink) {
789 		int e;
790 
791 		if ((e = nd6_prefix_onlink(new)) != 0) {
792 			nd6log((LOG_ERR, "nd6_prelist_add: failed to make "
793 			    "the prefix %s/%d on-link on %s (errno=%d)\n",
794 			    ip6_sprintf(&pr->ndpr_prefix.sin6_addr),
795 			    pr->ndpr_plen, if_name(pr->ndpr_ifp), e));
796 			/* proceed anyway. XXX: is it correct? */
797 		}
798 	}
799 
800 	if (dr)
801 		pfxrtr_add(new, dr);
802 
803 	return 0;
804 }
805 
806 void
807 prelist_remove(struct nd_prefix *pr)
808 {
809 	struct nd_pfxrouter *pfr, *next;
810 	int e;
811 
812 	/* make sure to invalidate the prefix until it is really freed. */
813 	pr->ndpr_vltime = 0;
814 	pr->ndpr_pltime = 0;
815 #if 0
816 	/*
817 	 * Though these flags are now meaningless, we'd rather keep the value
818 	 * not to confuse users when executing "ndp -p".
819 	 */
820 	pr->ndpr_raf_onlink = 0;
821 	pr->ndpr_raf_auto = 0;
822 #endif
823 	if ((pr->ndpr_stateflags & NDPRF_ONLINK) &&
824 	    (e = nd6_prefix_offlink(pr)) != 0) {
825 		nd6log((LOG_ERR, "prelist_remove: failed to make %s/%d offlink "
826 		    "on %s, errno=%d\n",
827 		    ip6_sprintf(&pr->ndpr_prefix.sin6_addr),
828 		    pr->ndpr_plen, if_name(pr->ndpr_ifp), e));
829 		/* what should we do? */
830 	}
831 
832 	if (pr->ndpr_refcnt > 0)
833 		return;		/* notice here? */
834 
835 	mtx_lock(&nd6_mtx);
836 
837 	/* unlink ndpr_entry from nd_prefix list */
838 	LIST_REMOVE(pr, ndpr_entry);
839 
840 	/* free list of routers that adversed the prefix */
841 	for (pfr = pr->ndpr_advrtrs.lh_first; pfr; pfr = next) {
842 		next = pfr->pfr_next;
843 
844 		kfree(pfr, M_IP6NDP);
845 	}
846 	mtx_unlock(&nd6_mtx);
847 
848 	kfree(pr, M_IP6NDP);
849 
850 	pfxlist_onlink_check();
851 }
852 
853 /*
854  * Parameters:
855  *	dr:	may be NULL
856  */
857 int
858 prelist_update(struct nd_prefix *new, struct nd_defrouter *dr, struct mbuf *m)
859 {
860 	struct in6_ifaddr *ia6 = NULL, *ia6_match = NULL;
861 	struct ifaddr_container *ifac;
862 	struct ifnet *ifp = new->ndpr_ifp;
863 	struct nd_prefix *pr;
864 	int error = 0;
865 	int auth;
866 	struct in6_addrlifetime lt6_tmp;
867 
868 	auth = 0;
869 	mtx_lock(&nd6_mtx);
870 	if (m) {
871 		/*
872 		 * Authenticity for NA consists authentication for
873 		 * both IP header and IP datagrams, doesn't it ?
874 		 */
875 #if defined(M_AUTHIPHDR) && defined(M_AUTHIPDGM)
876 		auth = ((m->m_flags & M_AUTHIPHDR) &&
877 		    (m->m_flags & M_AUTHIPDGM));
878 #endif
879 	}
880 
881 	if ((pr = nd6_prefix_lookup(new)) != NULL) {
882 		/*
883 		 * nd6_prefix_lookup() ensures that pr and new have the same
884 		 * prefix on a same interface.
885 		 */
886 
887 		/*
888 		 * Update prefix information.  Note that the on-link (L) bit
889 		 * and the autonomous (A) bit should NOT be changed from 1
890 		 * to 0.
891 		 */
892 		if (new->ndpr_raf_onlink == 1)
893 			pr->ndpr_raf_onlink = 1;
894 		if (new->ndpr_raf_auto == 1)
895 			pr->ndpr_raf_auto = 1;
896 		if (new->ndpr_raf_onlink) {
897 			pr->ndpr_vltime = new->ndpr_vltime;
898 			pr->ndpr_pltime = new->ndpr_pltime;
899 			pr->ndpr_preferred = new->ndpr_preferred;
900 			pr->ndpr_expire = new->ndpr_expire;
901 		}
902 
903 		if (new->ndpr_raf_onlink &&
904 		    !(pr->ndpr_stateflags & NDPRF_ONLINK)) {
905 			int e;
906 
907 			if ((e = nd6_prefix_onlink(pr)) != 0) {
908 				nd6log((LOG_ERR,
909 				    "prelist_update: failed to make "
910 				    "the prefix %s/%d on-link on %s "
911 				    "(errno=%d)\n",
912 				    ip6_sprintf(&pr->ndpr_prefix.sin6_addr),
913 				    pr->ndpr_plen, if_name(pr->ndpr_ifp), e));
914 				/* proceed anyway. XXX: is it correct? */
915 			}
916 		}
917 
918 		if (dr && pfxrtr_lookup(pr, dr) == NULL)
919 			pfxrtr_add(pr, dr);
920 	} else {
921 		struct nd_prefix *newpr = NULL;
922 
923 		if (new->ndpr_vltime == 0)
924 			goto end;
925 		if (new->ndpr_raf_onlink == 0 && new->ndpr_raf_auto == 0)
926 			goto end;
927 
928 		bzero(&new->ndpr_addr, sizeof(struct in6_addr));
929 
930 		error = nd6_prelist_add(new, dr, &newpr);
931 		if (error != 0 || newpr == NULL) {
932 			nd6log((LOG_NOTICE, "prelist_update: "
933 			    "nd6_prelist_add failed for %s/%d on %s "
934 			    "errno=%d, returnpr=%p\n",
935 			    ip6_sprintf(&new->ndpr_prefix.sin6_addr),
936 			    new->ndpr_plen, if_name(new->ndpr_ifp),
937 			    error, newpr));
938 			goto end; /* we should just give up in this case. */
939 		}
940 
941 		/*
942 		 * XXX: from the ND point of view, we can ignore a prefix
943 		 * with the on-link bit being zero.  However, we need a
944 		 * prefix structure for references from autoconfigured
945 		 * addresses.  Thus, we explicitly make sure that the prefix
946 		 * itself expires now.
947 		 */
948 		if (newpr->ndpr_raf_onlink == 0) {
949 			newpr->ndpr_vltime = 0;
950 			newpr->ndpr_pltime = 0;
951 			in6_init_prefix_ltimes(newpr);
952 		}
953 
954 		pr = newpr;
955 	}
956 
957 	/*
958 	 * Address autoconfiguration based on Section 5.5.3 of RFC 2462.
959 	 * Note that pr must be non NULL at this point.
960 	 */
961 
962 	/* 5.5.3 (a). Ignore the prefix without the A bit set. */
963 	if (!new->ndpr_raf_auto)
964 		goto afteraddrconf;
965 
966 	/*
967 	 * 5.5.3 (b). the link-local prefix should have been ignored in
968 	 * nd6_ra_input.
969 	 */
970 
971 	/*
972 	 * 5.5.3 (c). Consistency check on lifetimes: pltime <= vltime.
973 	 * This should have been done in nd6_ra_input.
974 	 */
975 
976  	/*
977 	 * 5.5.3 (d). If the prefix advertised does not match the prefix of an
978 	 * address already in the list, and the Valid Lifetime is not 0,
979 	 * form an address.  Note that even a manually configured address
980 	 * should reject autoconfiguration of a new address.
981 	 */
982 	TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid], ifa_link) {
983 		struct ifaddr *ifa = ifac->ifa;
984 		struct in6_ifaddr *ifa6;
985 		int ifa_plen;
986 		u_int32_t storedlifetime;
987 
988 		if (ifa->ifa_addr->sa_family != AF_INET6)
989 			continue;
990 
991 		ifa6 = (struct in6_ifaddr *)ifa;
992 
993 		/*
994 		 * Spec is not clear here, but I believe we should concentrate
995 		 * on unicast (i.e. not anycast) addresses.
996 		 * XXX: other ia6_flags? detached or duplicated?
997 		 */
998 		if (ifa6->ia6_flags & IN6_IFF_ANYCAST)
999 			continue;
1000 
1001 		ifa_plen = in6_mask2len(&ifa6->ia_prefixmask.sin6_addr, NULL);
1002 		if (ifa_plen != new->ndpr_plen ||
1003 		    !in6_are_prefix_equal(&ifa6->ia_addr.sin6_addr,
1004 		    &new->ndpr_prefix.sin6_addr, ifa_plen))
1005 			continue;
1006 
1007 		if (ia6_match == NULL) /* remember the first one */
1008 			ia6_match = ifa6;
1009 
1010 		if (!(ifa6->ia6_flags & IN6_IFF_AUTOCONF))
1011 			continue;
1012 
1013 		/*
1014 		 * An already autoconfigured address matched.  Now that we
1015 		 * are sure there is at least one matched address, we can
1016 		 * proceed to 5.5.3. (e): update the lifetimes according to the
1017 		 * "two hours" rule and the privacy extension.
1018 		 */
1019 #define TWOHOUR		(120*60)
1020 		lt6_tmp = ifa6->ia6_lifetime;
1021 
1022 		if (lt6_tmp.ia6t_vltime == ND6_INFINITE_LIFETIME)
1023 			storedlifetime = ND6_INFINITE_LIFETIME;
1024 		else if (IFA6_IS_INVALID(ifa6))
1025 			storedlifetime = 0;
1026 		else
1027 			storedlifetime = lt6_tmp.ia6t_expire - time_uptime;
1028 
1029 		/* when not updating, keep the current stored lifetime. */
1030 		lt6_tmp.ia6t_vltime = storedlifetime;
1031 
1032 		if (TWOHOUR < new->ndpr_vltime ||
1033 		    storedlifetime < new->ndpr_vltime) {
1034 			lt6_tmp.ia6t_vltime = new->ndpr_vltime;
1035 		} else if (storedlifetime <= TWOHOUR
1036 #if 0
1037 			   /*
1038 			    * This condition is logically redundant, so we just
1039 			    * omit it.
1040 			    * See IPng 6712, 6717, and 6721.
1041 			    */
1042 			   && new->ndpr_vltime <= storedlifetime
1043 #endif
1044 			) {
1045 			if (auth) {
1046 				lt6_tmp.ia6t_vltime = new->ndpr_vltime;
1047 			}
1048 		} else {
1049 			/*
1050 			 * new->ndpr_vltime <= TWOHOUR &&
1051 			 * TWOHOUR < storedlifetime
1052 			 */
1053 			lt6_tmp.ia6t_vltime = TWOHOUR;
1054 		}
1055 
1056 		/* The 2 hour rule is not imposed for preferred lifetime. */
1057 		lt6_tmp.ia6t_pltime = new->ndpr_pltime;
1058 
1059 		in6_init_address_ltimes(pr, &lt6_tmp);
1060 
1061 		/*
1062 		 * When adjusting the lifetimes of an existing temporary
1063 		 * address, only lower the lifetimes.
1064 		 * RFC 3041 3.3. (1).
1065 		 * XXX: how should we modify ia6t_[pv]ltime?
1066 		 */
1067 		if (ifa6->ia6_flags & IN6_IFF_TEMPORARY) {
1068 			if (lt6_tmp.ia6t_expire == 0 || /* no expire */
1069 			    lt6_tmp.ia6t_expire >
1070 			    ifa6->ia6_lifetime.ia6t_expire) {
1071 				lt6_tmp.ia6t_expire =
1072 				    ifa6->ia6_lifetime.ia6t_expire;
1073 			}
1074 			if (lt6_tmp.ia6t_preferred == 0 || /* no expire */
1075 			    lt6_tmp.ia6t_preferred >
1076 			    ifa6->ia6_lifetime.ia6t_preferred) {
1077 				lt6_tmp.ia6t_preferred =
1078 				    ifa6->ia6_lifetime.ia6t_preferred;
1079 			}
1080 		}
1081 
1082 		ifa6->ia6_lifetime = lt6_tmp;
1083 	}
1084 	if (ia6_match == NULL && new->ndpr_vltime) {
1085 		/*
1086 		 * No address matched and the valid lifetime is non-zero.
1087 		 * Create a new address.
1088 		 */
1089 		if ((ia6 = in6_ifadd(new, NULL)) != NULL) {
1090 			/*
1091 			 * note that we should use pr (not new) for reference.
1092 			 */
1093 			pr->ndpr_refcnt++;
1094 			ia6->ia6_ndpr = pr;
1095 
1096 			/*
1097 			 * RFC 3041 3.3 (2).
1098 			 * When a new public address is created as described
1099 			 * in RFC2462, also create a new temporary address.
1100 			 *
1101 			 * RFC 3041 3.5.
1102 			 * When an interface connects to a new link, a new
1103 			 * randomized interface identifier should be generated
1104 			 * immediately together with a new set of temporary
1105 			 * addresses.  Thus, we specifiy 1 as the 2nd arg of
1106 			 * in6_tmpifadd().
1107 			 */
1108 			if (ip6_use_tempaddr) {
1109 				int e;
1110 				if ((e = in6_tmpifadd(ia6, 1)) != 0) {
1111 					nd6log((LOG_NOTICE, "prelist_update: "
1112 					    "failed to create a temporary "
1113 					    "address, errno=%d\n",
1114 					    e));
1115 				}
1116 			}
1117 
1118 			/*
1119 			 * A newly added address might affect the status
1120 			 * of other addresses, so we check and update it.
1121 			 * XXX: what if address duplication happens?
1122 			 */
1123 			pfxlist_onlink_check();
1124 		} else {
1125 			/* just set an error. do not bark here. */
1126 			error = EADDRNOTAVAIL; /* XXX: might be unused. */
1127 		}
1128 	}
1129 
1130 afteraddrconf:
1131 
1132 end:
1133 	mtx_unlock(&nd6_mtx);
1134 	return error;
1135 }
1136 
1137 /*
1138  * A supplement function used in the on-link detection below;
1139  * detect if a given prefix has a (probably) reachable advertising router.
1140  * XXX: lengthy function name...
1141  */
1142 static struct nd_pfxrouter *
1143 find_pfxlist_reachable_router(struct nd_prefix *pr)
1144 {
1145 	struct nd_pfxrouter *pfxrtr;
1146 	struct rtentry *rt;
1147 	struct llinfo_nd6 *ln;
1148 
1149 	for (pfxrtr = LIST_FIRST(&pr->ndpr_advrtrs); pfxrtr;
1150 	     pfxrtr = LIST_NEXT(pfxrtr, pfr_entry)) {
1151 		if ((rt = nd6_lookup(&pfxrtr->router->rtaddr, 0,
1152 		    pfxrtr->router->ifp)) &&
1153 		    (ln = (struct llinfo_nd6 *)rt->rt_llinfo) &&
1154 		    ND6_IS_LLINFO_PROBREACH(ln))
1155 			break;	/* found */
1156 	}
1157 
1158 	return (pfxrtr);
1159 }
1160 
1161 /*
1162  * Check if each prefix in the prefix list has at least one available router
1163  * that advertised the prefix (a router is "available" if its neighbor cache
1164  * entry is reachable or probably reachable).
1165  * If the check fails, the prefix may be off-link, because, for example,
1166  * we have moved from the network but the lifetime of the prefix has not
1167  * expired yet.  So we should not use the prefix if there is another prefix
1168  * that has an available router.
1169  * But, if there is no prefix that has an available router, we still regards
1170  * all the prefixes as on-link.  This is because we can't tell if all the
1171  * routers are simply dead or if we really moved from the network and there
1172  * is no router around us.
1173  */
1174 void
1175 pfxlist_onlink_check(void)
1176 {
1177 	struct nd_prefix *pr;
1178 	struct in6_ifaddr *ifa;
1179 
1180 	/*
1181 	 * Check if there is a prefix that has a reachable advertising
1182 	 * router.
1183 	 */
1184 	for (pr = nd_prefix.lh_first; pr; pr = pr->ndpr_next) {
1185 		if (pr->ndpr_raf_onlink && find_pfxlist_reachable_router(pr))
1186 			break;
1187 	}
1188 
1189 	if (pr) {
1190 		/*
1191 		 * There is at least one prefix that has a reachable router.
1192 		 * Detach prefixes which have no reachable advertising
1193 		 * router, and attach other prefixes.
1194 		 */
1195 		for (pr = nd_prefix.lh_first; pr; pr = pr->ndpr_next) {
1196 			/* XXX: a link-local prefix should never be detached */
1197 			if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr))
1198 				continue;
1199 
1200 			/*
1201 			 * we aren't interested in prefixes without the L bit
1202 			 * set.
1203 			 */
1204 			if (pr->ndpr_raf_onlink == 0)
1205 				continue;
1206 
1207 			if (!(pr->ndpr_stateflags & NDPRF_DETACHED) &&
1208 			    find_pfxlist_reachable_router(pr) == NULL)
1209 				pr->ndpr_stateflags |= NDPRF_DETACHED;
1210 			if ((pr->ndpr_stateflags & NDPRF_DETACHED) &&
1211 			    find_pfxlist_reachable_router(pr) != NULL)
1212 				pr->ndpr_stateflags &= ~NDPRF_DETACHED;
1213 		}
1214 	} else {
1215 		/* there is no prefix that has a reachable router */
1216 		for (pr = nd_prefix.lh_first; pr; pr = pr->ndpr_next) {
1217 			if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr))
1218 				continue;
1219 
1220 			if (pr->ndpr_raf_onlink == 0)
1221 				continue;
1222 
1223 			if (pr->ndpr_stateflags & NDPRF_DETACHED)
1224 				pr->ndpr_stateflags &= ~NDPRF_DETACHED;
1225 		}
1226 	}
1227 
1228 	/*
1229 	 * Remove each interface route associated with a (just) detached
1230 	 * prefix, and reinstall the interface route for a (just) attached
1231 	 * prefix.  Note that all attempt of reinstallation does not
1232 	 * necessarily success, when a same prefix is shared among multiple
1233 	 * interfaces.  Such cases will be handled in nd6_prefix_onlink,
1234 	 * so we don't have to care about them.
1235 	 */
1236 	for (pr = nd_prefix.lh_first; pr; pr = pr->ndpr_next) {
1237 		int e;
1238 
1239 		if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr))
1240 			continue;
1241 
1242 		if (pr->ndpr_raf_onlink == 0)
1243 			continue;
1244 
1245 		if ((pr->ndpr_stateflags & NDPRF_DETACHED) &&
1246 		    (pr->ndpr_stateflags & NDPRF_ONLINK)) {
1247 			if ((e = nd6_prefix_offlink(pr)) != 0) {
1248 				nd6log((LOG_ERR,
1249 				    "pfxlist_onlink_check: failed to "
1250 				    "make %s/%d offlink, errno=%d\n",
1251 				    ip6_sprintf(&pr->ndpr_prefix.sin6_addr),
1252 				    pr->ndpr_plen, e));
1253 			}
1254 		}
1255 		if (!(pr->ndpr_stateflags & NDPRF_DETACHED) &&
1256 		    !(pr->ndpr_stateflags & NDPRF_ONLINK) &&
1257 		    pr->ndpr_raf_onlink) {
1258 			if ((e = nd6_prefix_onlink(pr)) != 0) {
1259 				nd6log((LOG_ERR,
1260 				    "pfxlist_onlink_check: failed to "
1261 				    "make %s/%d offlink, errno=%d\n",
1262 				    ip6_sprintf(&pr->ndpr_prefix.sin6_addr),
1263 				    pr->ndpr_plen, e));
1264 			}
1265 		}
1266 	}
1267 
1268 	/*
1269 	 * Changes on the prefix status might affect address status as well.
1270 	 * Make sure that all addresses derived from an attached prefix are
1271 	 * attached, and that all addresses derived from a detached prefix are
1272 	 * detached.  Note, however, that a manually configured address should
1273 	 * always be attached.
1274 	 * The precise detection logic is same as the one for prefixes.
1275 	 */
1276 	for (ifa = in6_ifaddr; ifa; ifa = ifa->ia_next) {
1277 		if (!(ifa->ia6_flags & IN6_IFF_AUTOCONF))
1278 			continue;
1279 
1280 		if (ifa->ia6_ndpr == NULL) {
1281 			/*
1282 			 * This can happen when we first configure the address
1283 			 * (i.e. the address exists, but the prefix does not).
1284 			 * XXX: complicated relationships...
1285 			 */
1286 			continue;
1287 		}
1288 
1289 		if (find_pfxlist_reachable_router(ifa->ia6_ndpr))
1290 			break;
1291 	}
1292 	if (ifa) {
1293 		for (ifa = in6_ifaddr; ifa; ifa = ifa->ia_next) {
1294 			if (!(ifa->ia6_flags & IN6_IFF_AUTOCONF))
1295 				continue;
1296 
1297 			if (ifa->ia6_ndpr == NULL) /* XXX: see above. */
1298 				continue;
1299 
1300 			if (find_pfxlist_reachable_router(ifa->ia6_ndpr))
1301 				ifa->ia6_flags &= ~IN6_IFF_DETACHED;
1302 			else
1303 				ifa->ia6_flags |= IN6_IFF_DETACHED;
1304 		}
1305 	}
1306 	else {
1307 		for (ifa = in6_ifaddr; ifa; ifa = ifa->ia_next) {
1308 			if (!(ifa->ia6_flags & IN6_IFF_AUTOCONF))
1309 				continue;
1310 
1311 			ifa->ia6_flags &= ~IN6_IFF_DETACHED;
1312 		}
1313 	}
1314 }
1315 
1316 int
1317 nd6_prefix_onlink(struct nd_prefix *pr)
1318 {
1319 	struct ifaddr *ifa;
1320 	struct ifnet *ifp = pr->ndpr_ifp;
1321 	struct sockaddr_in6 mask6;
1322 	struct nd_prefix *opr;
1323 	u_long rtflags;
1324 	int error = 0;
1325 
1326 	/* sanity check */
1327 	if (pr->ndpr_stateflags & NDPRF_ONLINK) {
1328 		nd6log((LOG_ERR,
1329 		    "nd6_prefix_onlink: %s/%d is already on-link\n",
1330 		    ip6_sprintf(&pr->ndpr_prefix.sin6_addr), pr->ndpr_plen);
1331 		return (EEXIST));
1332 	}
1333 
1334 	/*
1335 	 * Add the interface route associated with the prefix.  Before
1336 	 * installing the route, check if there's the same prefix on another
1337 	 * interface, and the prefix has already installed the interface route.
1338 	 * Although such a configuration is expected to be rare, we explicitly
1339 	 * allow it.
1340 	 */
1341 	for (opr = nd_prefix.lh_first; opr; opr = opr->ndpr_next) {
1342 		if (opr == pr)
1343 			continue;
1344 
1345 		if (!(opr->ndpr_stateflags & NDPRF_ONLINK))
1346 			continue;
1347 
1348 		if (opr->ndpr_plen == pr->ndpr_plen &&
1349 		    in6_are_prefix_equal(&pr->ndpr_prefix.sin6_addr,
1350 		    &opr->ndpr_prefix.sin6_addr, pr->ndpr_plen))
1351 			return (0);
1352 	}
1353 
1354 	/*
1355 	 * We prefer link-local addresses as the associated interface address.
1356 	 */
1357 	/* search for a link-local addr */
1358 	ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp,
1359 	    IN6_IFF_NOTREADY| IN6_IFF_ANYCAST);
1360 	if (ifa == NULL) {
1361 		struct ifaddr_container *ifac;
1362 
1363 		/* XXX: freebsd does not have ifa_ifwithaf */
1364 		TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid], ifa_link) {
1365 			if (ifac->ifa->ifa_addr->sa_family == AF_INET6) {
1366 				ifa = ifac->ifa;
1367 				break;
1368 			}
1369 		}
1370 		/* should we care about ia6_flags? */
1371 	}
1372 	if (ifa == NULL) {
1373 		/*
1374 		 * This can still happen, when, for example, we receive an RA
1375 		 * containing a prefix with the L bit set and the A bit clear,
1376 		 * after removing all IPv6 addresses on the receiving
1377 		 * interface.  This should, of course, be rare though.
1378 		 */
1379 		nd6log((LOG_NOTICE,
1380 		    "nd6_prefix_onlink: failed to find any ifaddr"
1381 		    " to add route for a prefix(%s/%d) on %s\n",
1382 		    ip6_sprintf(&pr->ndpr_prefix.sin6_addr),
1383 		    pr->ndpr_plen, if_name(ifp)));
1384 		return (0);
1385 	}
1386 
1387 	/*
1388 	 * in6_ifinit() sets nd6_rtrequest to ifa_rtrequest for all ifaddrs.
1389 	 * ifa->ifa_rtrequest = nd6_rtrequest;
1390 	 */
1391 	bzero(&mask6, sizeof(mask6));
1392 	mask6.sin6_len = sizeof(mask6);
1393 	mask6.sin6_addr = pr->ndpr_mask;
1394 	rtflags = ifa->ifa_flags | RTF_CLONING | RTF_UP;
1395 	if (nd6_need_cache(ifp)) {
1396 		/* explicitly set in case ifa_flags does not set the flag. */
1397 		rtflags |= RTF_CLONING;
1398 	} else {
1399 		/*
1400 		 * explicitly clear the cloning bit in case ifa_flags sets it.
1401 		 */
1402 		rtflags &= ~RTF_CLONING;
1403 	}
1404 	error = rtrequest_global(RTM_ADD, (struct sockaddr *)&pr->ndpr_prefix,
1405 	    ifa->ifa_addr, (struct sockaddr *)&mask6, rtflags);
1406 	if (error == 0) {
1407 		pr->ndpr_stateflags |= NDPRF_ONLINK;
1408 	} else {
1409 		nd6log((LOG_ERR, "nd6_prefix_onlink: failed to add route for a"
1410 		    " prefix (%s/%d) on %s, gw=%s, mask=%s, flags=%lx "
1411 		    "errno = %d\n",
1412 		    ip6_sprintf(&pr->ndpr_prefix.sin6_addr),
1413 		    pr->ndpr_plen, if_name(ifp),
1414 		    ip6_sprintf(&((struct sockaddr_in6 *)ifa->ifa_addr)->sin6_addr),
1415 		    ip6_sprintf(&mask6.sin6_addr), rtflags, error));
1416 	}
1417 	return (error);
1418 }
1419 
1420 int
1421 nd6_prefix_offlink(struct nd_prefix *pr)
1422 {
1423 	int error = 0;
1424 	struct ifnet *ifp = pr->ndpr_ifp;
1425 	struct nd_prefix *opr;
1426 	struct sockaddr_in6 sa6, mask6;
1427 
1428 	/* sanity check */
1429 	if (!(pr->ndpr_stateflags & NDPRF_ONLINK)) {
1430 		nd6log((LOG_ERR,
1431 		    "nd6_prefix_offlink: %s/%d is already off-link\n",
1432 		    ip6_sprintf(&pr->ndpr_prefix.sin6_addr), pr->ndpr_plen));
1433 		return (EEXIST);
1434 	}
1435 
1436 	bzero(&sa6, sizeof(sa6));
1437 	sa6.sin6_family = AF_INET6;
1438 	sa6.sin6_len = sizeof(sa6);
1439 	bcopy(&pr->ndpr_prefix.sin6_addr, &sa6.sin6_addr,
1440 	    sizeof(struct in6_addr));
1441 	bzero(&mask6, sizeof(mask6));
1442 	mask6.sin6_family = AF_INET6;
1443 	mask6.sin6_len = sizeof(sa6);
1444 	bcopy(&pr->ndpr_mask, &mask6.sin6_addr, sizeof(struct in6_addr));
1445 	error = rtrequest_global(RTM_DELETE, (struct sockaddr *)&sa6, NULL,
1446 	    (struct sockaddr *)&mask6, 0);
1447 	if (error == 0) {
1448 		pr->ndpr_stateflags &= ~NDPRF_ONLINK;
1449 
1450 		/*
1451 		 * There might be the same prefix on another interface,
1452 		 * the prefix which could not be on-link just because we have
1453 		 * the interface route (see comments in nd6_prefix_onlink).
1454 		 * If there's one, try to make the prefix on-link on the
1455 		 * interface.
1456 		 */
1457 		for (opr = nd_prefix.lh_first; opr; opr = opr->ndpr_next) {
1458 			if (opr == pr)
1459 				continue;
1460 
1461 			if (opr->ndpr_stateflags & NDPRF_ONLINK)
1462 				continue;
1463 
1464 			/*
1465 			 * KAME specific: detached prefixes should not be
1466 			 * on-link.
1467 			 */
1468 			if (opr->ndpr_stateflags & NDPRF_DETACHED)
1469 				continue;
1470 
1471 			if (opr->ndpr_plen == pr->ndpr_plen &&
1472 			    in6_are_prefix_equal(&pr->ndpr_prefix.sin6_addr,
1473 			    &opr->ndpr_prefix.sin6_addr, pr->ndpr_plen)) {
1474 				int e;
1475 
1476 				if ((e = nd6_prefix_onlink(opr)) != 0) {
1477 					nd6log((LOG_ERR,
1478 					    "nd6_prefix_offlink: failed to "
1479 					    "recover a prefix %s/%d from %s "
1480 					    "to %s (errno = %d)\n",
1481 					    ip6_sprintf(&opr->ndpr_prefix.sin6_addr),
1482 					    opr->ndpr_plen, if_name(ifp),
1483 					    if_name(opr->ndpr_ifp), e));
1484 				}
1485 			}
1486 		}
1487 	} else {
1488 		/* XXX: can we still set the NDPRF_ONLINK flag? */
1489 		nd6log((LOG_ERR,
1490 		    "nd6_prefix_offlink: failed to delete route: "
1491 		    "%s/%d on %s (errno = %d)\n",
1492 		    ip6_sprintf(&sa6.sin6_addr), pr->ndpr_plen, if_name(ifp),
1493 		    error));
1494 	}
1495 
1496 	return (error);
1497 }
1498 
1499 /*
1500  * Parameters:
1501  *	ifid:	Mobile IPv6 addition
1502  */
1503 static struct in6_ifaddr *
1504 in6_ifadd(struct nd_prefix *pr, struct in6_addr *ifid)
1505 {
1506 	struct ifnet *ifp = pr->ndpr_ifp;
1507 	struct ifaddr *ifa;
1508 	struct in6_aliasreq ifra;
1509 	struct in6_ifaddr *ia, *ib;
1510 	int error, plen0;
1511 	struct in6_addr mask;
1512 	int prefixlen = pr->ndpr_plen;
1513 
1514 	in6_prefixlen2mask(&mask, prefixlen);
1515 
1516 	/*
1517 	 * find a link-local address (will be interface ID).
1518 	 * Is it really mandatory? Theoretically, a global or a site-local
1519 	 * address can be configured without a link-local address, if we
1520 	 * have a unique interface identifier...
1521 	 *
1522 	 * it is not mandatory to have a link-local address, we can generate
1523 	 * interface identifier on the fly.  we do this because:
1524 	 * (1) it should be the easiest way to find interface identifier.
1525 	 * (2) RFC2462 5.4 suggesting the use of the same interface identifier
1526 	 * for multiple addresses on a single interface, and possible shortcut
1527 	 * of DAD.  we omitted DAD for this reason in the past.
1528 	 * (3) a user can prevent autoconfiguration of global address
1529 	 * by removing link-local address by hand (this is partly because we
1530 	 * don't have other way to control the use of IPv6 on a interface.
1531 	 * this has been our design choice - cf. NRL's "ifconfig auto").
1532 	 * (4) it is easier to manage when an interface has addresses
1533 	 * with the same interface identifier, than to have multiple addresses
1534 	 * with different interface identifiers.
1535 	 *
1536 	 * Mobile IPv6 addition: allow for caller to specify a wished interface
1537 	 * ID. This is to not break connections when moving addresses between
1538 	 * interfaces.
1539 	 */
1540 	ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp, 0); /* 0 is OK? */
1541 	if (ifa)
1542 		ib = (struct in6_ifaddr *)ifa;
1543 	else
1544 		return NULL;
1545 
1546 #if 0 /* don't care link local addr state, and always do DAD */
1547 	/* if link-local address is not eligible, do not autoconfigure. */
1548 	if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_NOTREADY) {
1549 		kprintf("in6_ifadd: link-local address not ready\n");
1550 		return NULL;
1551 	}
1552 #endif
1553 
1554 	/* prefixlen + ifidlen must be equal to 128 */
1555 	plen0 = in6_mask2len(&ib->ia_prefixmask.sin6_addr, NULL);
1556 	if (prefixlen != plen0) {
1557 		nd6log((LOG_INFO, "in6_ifadd: wrong prefixlen for %s "
1558 		    "(prefix=%d ifid=%d)\n",
1559 		    if_name(ifp), prefixlen, 128 - plen0));
1560 		return NULL;
1561 	}
1562 
1563 	/* make ifaddr */
1564 
1565 	bzero(&ifra, sizeof(ifra));
1566 	/*
1567 	 * in6_update_ifa() does not use ifra_name, but we accurately set it
1568 	 * for safety.
1569 	 */
1570 	strncpy(ifra.ifra_name, if_name(ifp), sizeof(ifra.ifra_name));
1571 	ifra.ifra_addr.sin6_family = AF_INET6;
1572 	ifra.ifra_addr.sin6_len = sizeof(struct sockaddr_in6);
1573 	/* prefix */
1574 	bcopy(&pr->ndpr_prefix.sin6_addr, &ifra.ifra_addr.sin6_addr,
1575 	    sizeof(ifra.ifra_addr.sin6_addr));
1576 	ifra.ifra_addr.sin6_addr.s6_addr32[0] &= mask.s6_addr32[0];
1577 	ifra.ifra_addr.sin6_addr.s6_addr32[1] &= mask.s6_addr32[1];
1578 	ifra.ifra_addr.sin6_addr.s6_addr32[2] &= mask.s6_addr32[2];
1579 	ifra.ifra_addr.sin6_addr.s6_addr32[3] &= mask.s6_addr32[3];
1580 
1581 	/* interface ID */
1582 	if (ifid == NULL || IN6_IS_ADDR_UNSPECIFIED(ifid))
1583 		ifid = &ib->ia_addr.sin6_addr;
1584 	ifra.ifra_addr.sin6_addr.s6_addr32[0] |=
1585 	    (ifid->s6_addr32[0] & ~mask.s6_addr32[0]);
1586 	ifra.ifra_addr.sin6_addr.s6_addr32[1] |=
1587 	    (ifid->s6_addr32[1] & ~mask.s6_addr32[1]);
1588 	ifra.ifra_addr.sin6_addr.s6_addr32[2] |=
1589 	    (ifid->s6_addr32[2] & ~mask.s6_addr32[2]);
1590 	ifra.ifra_addr.sin6_addr.s6_addr32[3] |=
1591 	    (ifid->s6_addr32[3] & ~mask.s6_addr32[3]);
1592 
1593 	/* new prefix mask. */
1594 	ifra.ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6);
1595 	ifra.ifra_prefixmask.sin6_family = AF_INET6;
1596 	bcopy(&mask, &ifra.ifra_prefixmask.sin6_addr,
1597 	    sizeof(ifra.ifra_prefixmask.sin6_addr));
1598 
1599 	/*
1600 	 * lifetime.
1601 	 * XXX: in6_init_address_ltimes would override these values later.
1602 	 * We should reconsider this logic.
1603 	 */
1604 	ifra.ifra_lifetime.ia6t_vltime = pr->ndpr_vltime;
1605 	ifra.ifra_lifetime.ia6t_pltime = pr->ndpr_pltime;
1606 
1607 	/* XXX: scope zone ID? */
1608 
1609 	ifra.ifra_flags |= IN6_IFF_AUTOCONF; /* obey autoconf */
1610 	/*
1611 	 * temporarily set the nopfx flag to avoid conflict.
1612 	 * XXX: we should reconsider the entire mechanism about prefix
1613 	 * manipulation.
1614 	 */
1615 	ifra.ifra_flags |= IN6_IFF_NOPFX;
1616 
1617 	/*
1618 	 * keep the new address, regardless of the result of in6_update_ifa.
1619 	 * XXX: this address is now meaningless.
1620 	 * We should reconsider its role.
1621 	 */
1622 	pr->ndpr_addr = ifra.ifra_addr.sin6_addr;
1623 
1624 	/* allocate ifaddr structure, link into chain, etc. */
1625 	if ((error = in6_update_ifa(ifp, &ifra, NULL)) != 0) {
1626 		nd6log((LOG_ERR,
1627 		    "in6_ifadd: failed to make ifaddr %s on %s (errno=%d)\n",
1628 		    ip6_sprintf(&ifra.ifra_addr.sin6_addr), if_name(ifp),
1629 		    error));
1630 		return (NULL);	/* ifaddr must not have been allocated. */
1631 	}
1632 
1633 	ia = in6ifa_ifpwithaddr(ifp, &ifra.ifra_addr.sin6_addr);
1634 
1635 	return (ia);		/* this is always non-NULL */
1636 }
1637 
1638 /*
1639  * Parameters:
1640  *	ia0:	corresponding public address
1641  */
1642 int
1643 in6_tmpifadd(const struct in6_ifaddr *ia0, int forcegen)
1644 {
1645 	struct ifnet *ifp = ia0->ia_ifa.ifa_ifp;
1646 	struct in6_ifaddr *newia;
1647 	struct in6_aliasreq ifra;
1648 	int i, error;
1649 	int trylimit = 3;	/* XXX: adhoc value */
1650 	u_int32_t randid[2];
1651 	time_t vltime0, pltime0;
1652 
1653 	bzero(&ifra, sizeof(ifra));
1654 	strncpy(ifra.ifra_name, if_name(ifp), sizeof(ifra.ifra_name));
1655 	ifra.ifra_addr = ia0->ia_addr;
1656 	/* copy prefix mask */
1657 	ifra.ifra_prefixmask = ia0->ia_prefixmask;
1658 	/* clear the old IFID */
1659 	for (i = 0; i < 4; i++) {
1660 		ifra.ifra_addr.sin6_addr.s6_addr32[i] &=
1661 		    ifra.ifra_prefixmask.sin6_addr.s6_addr32[i];
1662 	}
1663 
1664 again:
1665 	in6_get_tmpifid(ifp, (u_int8_t *)randid,
1666 	    (const u_int8_t *)&ia0->ia_addr.sin6_addr.s6_addr[8], forcegen);
1667 	ifra.ifra_addr.sin6_addr.s6_addr32[2] |=
1668 	    (randid[0] & ~(ifra.ifra_prefixmask.sin6_addr.s6_addr32[2]));
1669 	ifra.ifra_addr.sin6_addr.s6_addr32[3] |=
1670 	    (randid[1] & ~(ifra.ifra_prefixmask.sin6_addr.s6_addr32[3]));
1671 
1672 	/*
1673 	 * If by chance the new temporary address is the same as an address
1674 	 * already assigned to the interface, generate a new randomized
1675 	 * interface identifier and repeat this step.
1676 	 * RFC 3041 3.3 (4).
1677 	 */
1678 	if (in6ifa_ifpwithaddr(ifp, &ifra.ifra_addr.sin6_addr) != NULL) {
1679 		if (trylimit-- == 0) {
1680 			nd6log((LOG_NOTICE, "in6_tmpifadd: failed to find "
1681 			    "a unique random IFID\n"));
1682 			return (EEXIST);
1683 		}
1684 		forcegen = 1;
1685 		goto again;
1686 	}
1687 
1688 	/*
1689 	 * The Valid Lifetime is the lower of the Valid Lifetime of the
1690          * public address or TEMP_VALID_LIFETIME.
1691 	 * The Preferred Lifetime is the lower of the Preferred Lifetime
1692          * of the public address or TEMP_PREFERRED_LIFETIME -
1693          * DESYNC_FACTOR.
1694 	 */
1695 	if (ia0->ia6_lifetime.ia6t_expire != 0) {
1696 		vltime0 = IFA6_IS_INVALID(ia0) ?
1697 		    0 : (ia0->ia6_lifetime.ia6t_expire - time_uptime);
1698 		if (vltime0 > ip6_temp_valid_lifetime)
1699 			vltime0 = ip6_temp_valid_lifetime;
1700 	} else
1701 		vltime0 = ip6_temp_valid_lifetime;
1702 	if (ia0->ia6_lifetime.ia6t_preferred != 0) {
1703 		pltime0 = IFA6_IS_DEPRECATED(ia0) ?
1704 		    0 : (ia0->ia6_lifetime.ia6t_preferred - time_uptime);
1705 		if (pltime0 > ip6_temp_preferred_lifetime - ip6_desync_factor) {
1706 			pltime0 = ip6_temp_preferred_lifetime -
1707 			    ip6_desync_factor;
1708 		}
1709 	} else
1710 		pltime0 = ip6_temp_preferred_lifetime - ip6_desync_factor;
1711 	ifra.ifra_lifetime.ia6t_vltime = vltime0;
1712 	ifra.ifra_lifetime.ia6t_pltime = pltime0;
1713 
1714 	/*
1715 	 * A temporary address is created only if this calculated Preferred
1716 	 * Lifetime is greater than REGEN_ADVANCE time units.
1717 	 */
1718 	if (ifra.ifra_lifetime.ia6t_pltime <= ip6_temp_regen_advance)
1719 		return (0);
1720 
1721 	/* XXX: scope zone ID? */
1722 
1723 	ifra.ifra_flags |= (IN6_IFF_AUTOCONF|IN6_IFF_TEMPORARY);
1724 
1725 	/* allocate ifaddr structure, link into chain, etc. */
1726 	if ((error = in6_update_ifa(ifp, &ifra, NULL)) != 0)
1727 		return (error);
1728 
1729 	newia = in6ifa_ifpwithaddr(ifp, &ifra.ifra_addr.sin6_addr);
1730 	if (newia == NULL) {	/* XXX: can it happen? */
1731 		nd6log((LOG_ERR,
1732 		    "in6_tmpifadd: ifa update succeeded, but we got "
1733 		    "no ifaddr\n"));
1734 		return (EINVAL); /* XXX */
1735 	}
1736 	newia->ia6_ndpr = ia0->ia6_ndpr;
1737 	newia->ia6_ndpr->ndpr_refcnt++;
1738 
1739 	return (0);
1740 }
1741 
1742 int
1743 in6_init_prefix_ltimes(struct nd_prefix *ndpr)
1744 {
1745 	/* check if preferred lifetime > valid lifetime.  RFC2462 5.5.3 (c) */
1746 	if (ndpr->ndpr_pltime > ndpr->ndpr_vltime) {
1747 		nd6log((LOG_INFO, "in6_init_prefix_ltimes: preferred lifetime"
1748 		    "(%d) is greater than valid lifetime(%d)\n",
1749 		    (u_int)ndpr->ndpr_pltime, (u_int)ndpr->ndpr_vltime));
1750 		return (EINVAL);
1751 	}
1752 	if (ndpr->ndpr_pltime == ND6_INFINITE_LIFETIME)
1753 		ndpr->ndpr_preferred = 0;
1754 	else
1755 		ndpr->ndpr_preferred = time_uptime + ndpr->ndpr_pltime;
1756 	if (ndpr->ndpr_vltime == ND6_INFINITE_LIFETIME)
1757 		ndpr->ndpr_expire = 0;
1758 	else
1759 		ndpr->ndpr_expire = time_uptime + ndpr->ndpr_vltime;
1760 
1761 	return 0;
1762 }
1763 
1764 static void
1765 in6_init_address_ltimes(struct nd_prefix *new, struct in6_addrlifetime *lt6)
1766 {
1767 	/* init ia6t_expire */
1768 	if (lt6->ia6t_vltime == ND6_INFINITE_LIFETIME)
1769 		lt6->ia6t_expire = 0;
1770 	else {
1771 		lt6->ia6t_expire = time_uptime;
1772 		lt6->ia6t_expire += lt6->ia6t_vltime;
1773 	}
1774 
1775 	/* init ia6t_preferred */
1776 	if (lt6->ia6t_pltime == ND6_INFINITE_LIFETIME)
1777 		lt6->ia6t_preferred = 0;
1778 	else {
1779 		lt6->ia6t_preferred = time_uptime;
1780 		lt6->ia6t_preferred += lt6->ia6t_pltime;
1781 	}
1782 }
1783 
1784 /*
1785  * Delete all the routing table entries that use the specified gateway.
1786  *
1787  * XXX: this function causes search through all entries of routing table, so
1788  * it shouldn't be called when acting as a router.
1789  */
1790 void
1791 rt6_flush(struct in6_addr *gateway, struct ifnet *ifp)
1792 {
1793 	struct radix_node_head *rnh = rt_tables[mycpuid][AF_INET6];
1794 
1795 	/* We'll care only link-local addresses */
1796 	if (!IN6_IS_ADDR_LINKLOCAL(gateway))
1797 		return;
1798 	/* XXX: hack for KAME's link-local address kludge */
1799 	gateway->s6_addr16[1] = htons(ifp->if_index);
1800 
1801 	rnh->rnh_walktree(rnh, rt6_deleteroute, (void *)gateway);
1802 }
1803 
1804 static int
1805 rt6_deleteroute(struct radix_node *rn, void *arg)
1806 {
1807 #define SIN6(s)	((struct sockaddr_in6 *)s)
1808 	struct rtentry *rt = (struct rtentry *)rn;
1809 	struct in6_addr *gate = (struct in6_addr *)arg;
1810 
1811 	if (rt->rt_gateway == NULL || rt->rt_gateway->sa_family != AF_INET6)
1812 		return (0);
1813 
1814 	if (!IN6_ARE_ADDR_EQUAL(gate, &SIN6(rt->rt_gateway)->sin6_addr))
1815 		return (0);
1816 
1817 	/*
1818 	 * Do not delete a static route.
1819 	 * XXX: this seems to be a bit ad-hoc. Should we consider the
1820 	 * 'cloned' bit instead?
1821 	 */
1822 	if (rt->rt_flags & RTF_STATIC)
1823 		return (0);
1824 
1825 	/*
1826 	 * We delete only host route. This means, in particular, we don't
1827 	 * delete default route.
1828 	 */
1829 	if (!(rt->rt_flags & RTF_HOST))
1830 		return (0);
1831 
1832 	return (rtrequest(RTM_DELETE, rt_key(rt), rt->rt_gateway, rt_mask(rt),
1833 	    rt->rt_flags, 0));
1834 #undef SIN6
1835 }
1836 
1837 int
1838 nd6_setdefaultiface(int ifindex)
1839 {
1840 	int error = 0;
1841 
1842 	if (ifindex < 0 || if_index < ifindex)
1843 		return (EINVAL);
1844 
1845 	if (nd6_defifindex != ifindex) {
1846 		nd6_defifindex = ifindex;
1847 		if (nd6_defifindex > 0)
1848 			nd6_defifp = ifindex2ifnet[nd6_defifindex];
1849 		else
1850 			nd6_defifp = NULL;
1851 
1852 		/*
1853 		 * If the Default Router List is empty, install a route
1854 		 * to the specified interface as default or remove the default
1855 		 * route when the default interface becomes canceled.
1856 		 * The check for the queue is actually redundant, but
1857 		 * we do this here to avoid re-install the default route
1858 		 * if the list is NOT empty.
1859 		 */
1860 		if (TAILQ_FIRST(&nd_defrouter) == NULL)
1861 			defrouter_select();
1862 
1863 		/*
1864 		 * Our current implementation assumes one-to-one maping between
1865 		 * interfaces and links, so it would be natural to use the
1866 		 * default interface as the default link.
1867 		 */
1868 		scope6_setdefault(nd6_defifp);
1869 	}
1870 
1871 	return (error);
1872 }
1873