xref: /dragonfly/sys/netinet6/nd6_rtr.c (revision 6b5c5d0d)
1 /*	$FreeBSD: src/sys/netinet6/nd6_rtr.c,v 1.2.2.5 2003/04/05 10:28:53 ume Exp $	*/
2 /*	$DragonFly: src/sys/netinet6/nd6_rtr.c,v 1.16 2008/01/05 14:02:40 swildner Exp $	*/
3 /*	$KAME: nd6_rtr.c,v 1.111 2001/04/27 01:37:15 jinmei Exp $	*/
4 
5 /*
6  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. Neither the name of the project nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #include "opt_inet.h"
35 #include "opt_inet6.h"
36 
37 #include <sys/param.h>
38 #include <sys/systm.h>
39 #include <sys/malloc.h>
40 #include <sys/mbuf.h>
41 #include <sys/socket.h>
42 #include <sys/sockio.h>
43 #include <sys/time.h>
44 #include <sys/kernel.h>
45 #include <sys/errno.h>
46 #include <sys/syslog.h>
47 #include <sys/queue.h>
48 #include <sys/globaldata.h>
49 #include <sys/thread2.h>
50 
51 #include <net/if.h>
52 #include <net/if_types.h>
53 #include <net/if_dl.h>
54 #include <net/route.h>
55 #include <net/radix.h>
56 
57 #include <netinet/in.h>
58 #include <netinet6/in6_var.h>
59 #include <netinet6/in6_ifattach.h>
60 #include <netinet/ip6.h>
61 #include <netinet6/ip6_var.h>
62 #include <netinet6/nd6.h>
63 #include <netinet/icmp6.h>
64 #include <netinet6/scope6_var.h>
65 
66 #include <net/net_osdep.h>
67 
68 #define SDL(s)	((struct sockaddr_dl *)s)
69 
70 static struct nd_defrouter *defrtrlist_update (struct nd_defrouter *);
71 static struct in6_ifaddr *in6_ifadd (struct nd_prefix *,
72 	struct in6_addr *);
73 static struct nd_pfxrouter *pfxrtr_lookup (struct nd_prefix *,
74 	struct nd_defrouter *);
75 static void pfxrtr_add (struct nd_prefix *, struct nd_defrouter *);
76 static void pfxrtr_del (struct nd_pfxrouter *);
77 static struct nd_pfxrouter *find_pfxlist_reachable_router
78 	(struct nd_prefix *);
79 static void defrouter_addifreq (struct ifnet *);
80 static void nd6_rtmsg (int, struct rtentry *);
81 
82 static void in6_init_address_ltimes (struct nd_prefix *ndpr,
83 					 struct in6_addrlifetime *lt6);
84 
85 static int rt6_deleteroute (struct radix_node *, void *);
86 
87 extern int nd6_recalc_reachtm_interval;
88 
89 static struct ifnet *nd6_defifp;
90 int nd6_defifindex;
91 
92 int ip6_use_tempaddr = 0;
93 
94 int ip6_desync_factor;
95 u_int32_t ip6_temp_preferred_lifetime = DEF_TEMP_PREFERRED_LIFETIME;
96 u_int32_t ip6_temp_valid_lifetime = DEF_TEMP_VALID_LIFETIME;
97 /*
98  * shorter lifetimes for debugging purposes.
99 int ip6_temp_preferred_lifetime = 800;
100 static int ip6_temp_valid_lifetime = 1800;
101 */
102 int ip6_temp_regen_advance = TEMPADDR_REGEN_ADVANCE;
103 
104 /*
105  * Receive Router Solicitation Message - just for routers.
106  * Router solicitation/advertisement is mostly managed by userland program
107  * (rtadvd) so here we have no function like nd6_ra_output().
108  *
109  * Based on RFC 2461
110  */
111 void
112 nd6_rs_input(struct mbuf *m, int off, int icmp6len)
113 {
114 	struct ifnet *ifp = m->m_pkthdr.rcvif;
115 	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
116 	struct nd_router_solicit *nd_rs;
117 	struct in6_addr saddr6 = ip6->ip6_src;
118 #if 0
119 	struct in6_addr daddr6 = ip6->ip6_dst;
120 #endif
121 	char *lladdr = NULL;
122 	int lladdrlen = 0;
123 #if 0
124 	struct sockaddr_dl *sdl = (struct sockaddr_dl *)NULL;
125 	struct llinfo_nd6 *ln = (struct llinfo_nd6 *)NULL;
126 	struct rtentry *rt = NULL;
127 	int is_newentry;
128 #endif
129 	union nd_opts ndopts;
130 
131 	/* If I'm not a router, ignore it. */
132 	if (ip6_accept_rtadv != 0 || ip6_forwarding != 1)
133 		goto freeit;
134 
135 	/* Sanity checks */
136 	if (ip6->ip6_hlim != 255) {
137 		nd6log((LOG_ERR,
138 		    "nd6_rs_input: invalid hlim (%d) from %s to %s on %s\n",
139 		    ip6->ip6_hlim, ip6_sprintf(&ip6->ip6_src),
140 		    ip6_sprintf(&ip6->ip6_dst), if_name(ifp)));
141 		goto bad;
142 	}
143 
144 	/*
145 	 * Don't update the neighbor cache, if src = ::.
146 	 * This indicates that the src has no IP address assigned yet.
147 	 */
148 	if (IN6_IS_ADDR_UNSPECIFIED(&saddr6))
149 		goto freeit;
150 
151 #ifndef PULLDOWN_TEST
152 	IP6_EXTHDR_CHECK(m, off, icmp6len,);
153 	nd_rs = (struct nd_router_solicit *)((caddr_t)ip6 + off);
154 #else
155 	IP6_EXTHDR_GET(nd_rs, struct nd_router_solicit *, m, off, icmp6len);
156 	if (nd_rs == NULL) {
157 		icmp6stat.icp6s_tooshort++;
158 		return;
159 	}
160 #endif
161 
162 	icmp6len -= sizeof(*nd_rs);
163 	nd6_option_init(nd_rs + 1, icmp6len, &ndopts);
164 	if (nd6_options(&ndopts) < 0) {
165 		nd6log((LOG_INFO,
166 		    "nd6_rs_input: invalid ND option, ignored\n"));
167 		/* nd6_options have incremented stats */
168 		goto freeit;
169 	}
170 
171 	if (ndopts.nd_opts_src_lladdr) {
172 		lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1);
173 		lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3;
174 	}
175 
176 	if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
177 		nd6log((LOG_INFO,
178 		    "nd6_rs_input: lladdrlen mismatch for %s "
179 		    "(if %d, RS packet %d)\n",
180 			ip6_sprintf(&saddr6), ifp->if_addrlen, lladdrlen - 2));
181 		goto bad;
182 	}
183 
184 	nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, ND_ROUTER_SOLICIT, 0);
185 
186 freeit:
187 	m_freem(m);
188 	return;
189 
190 bad:
191 	icmp6stat.icp6s_badrs++;
192 	m_freem(m);
193 }
194 
195 /*
196  * Receive Router Advertisement Message.
197  *
198  * Based on RFC 2461
199  * TODO: on-link bit on prefix information
200  * TODO: ND_RA_FLAG_{OTHER,MANAGED} processing
201  */
202 void
203 nd6_ra_input(struct mbuf *m, int off, int icmp6len)
204 {
205 	struct ifnet *ifp = m->m_pkthdr.rcvif;
206 	struct nd_ifinfo *ndi = ND_IFINFO(ifp);
207 	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
208 	struct nd_router_advert *nd_ra;
209 	struct in6_addr saddr6 = ip6->ip6_src;
210 #if 0
211 	struct in6_addr daddr6 = ip6->ip6_dst;
212 	int flags; /* = nd_ra->nd_ra_flags_reserved; */
213 	int is_managed = ((flags & ND_RA_FLAG_MANAGED) != 0);
214 	int is_other = ((flags & ND_RA_FLAG_OTHER) != 0);
215 #endif
216 	union nd_opts ndopts;
217 	struct nd_defrouter *dr;
218 
219 	/*
220 	 * We only accept RAs only when
221 	 * the system-wide variable allows the acceptance, and
222 	 * per-interface variable allows RAs on the receiving interface.
223 	 */
224 	if (ip6_accept_rtadv == 0)
225 		goto freeit;
226 	if (!(ndi->flags & ND6_IFF_ACCEPT_RTADV))
227 		goto freeit;
228 
229 	if (ip6->ip6_hlim != 255) {
230 		nd6log((LOG_ERR,
231 		    "nd6_ra_input: invalid hlim (%d) from %s to %s on %s\n",
232 		    ip6->ip6_hlim, ip6_sprintf(&ip6->ip6_src),
233 		    ip6_sprintf(&ip6->ip6_dst), if_name(ifp)));
234 		goto bad;
235 	}
236 
237 	if (!IN6_IS_ADDR_LINKLOCAL(&saddr6)) {
238 		nd6log((LOG_ERR,
239 		    "nd6_ra_input: src %s is not link-local\n",
240 		    ip6_sprintf(&saddr6)));
241 		goto bad;
242 	}
243 
244 #ifndef PULLDOWN_TEST
245 	IP6_EXTHDR_CHECK(m, off, icmp6len,);
246 	nd_ra = (struct nd_router_advert *)((caddr_t)ip6 + off);
247 #else
248 	IP6_EXTHDR_GET(nd_ra, struct nd_router_advert *, m, off, icmp6len);
249 	if (nd_ra == NULL) {
250 		icmp6stat.icp6s_tooshort++;
251 		return;
252 	}
253 #endif
254 
255 	icmp6len -= sizeof(*nd_ra);
256 	nd6_option_init(nd_ra + 1, icmp6len, &ndopts);
257 	if (nd6_options(&ndopts) < 0) {
258 		nd6log((LOG_INFO,
259 		    "nd6_ra_input: invalid ND option, ignored\n"));
260 		/* nd6_options have incremented stats */
261 		goto freeit;
262 	}
263 
264     {
265 	struct nd_defrouter dr0;
266 	u_int32_t advreachable = nd_ra->nd_ra_reachable;
267 
268 	dr0.rtaddr = saddr6;
269 	dr0.flags  = nd_ra->nd_ra_flags_reserved;
270 	dr0.rtlifetime = ntohs(nd_ra->nd_ra_router_lifetime);
271 	dr0.expire = time_second + dr0.rtlifetime;
272 	dr0.ifp = ifp;
273 	dr0.advint = 0;		/* Mobile IPv6 */
274 	dr0.advint_expire = 0;	/* Mobile IPv6 */
275 	dr0.advints_lost = 0;	/* Mobile IPv6 */
276 	/* unspecified or not? (RFC 2461 6.3.4) */
277 	if (advreachable) {
278 		advreachable = ntohl(advreachable);
279 		if (advreachable <= MAX_REACHABLE_TIME &&
280 		    ndi->basereachable != advreachable) {
281 			ndi->basereachable = advreachable;
282 			ndi->reachable = ND_COMPUTE_RTIME(ndi->basereachable);
283 			ndi->recalctm = nd6_recalc_reachtm_interval; /* reset */
284 		}
285 	}
286 	if (nd_ra->nd_ra_retransmit)
287 		ndi->retrans = ntohl(nd_ra->nd_ra_retransmit);
288 	if (nd_ra->nd_ra_curhoplimit)
289 		ndi->chlim = nd_ra->nd_ra_curhoplimit;
290 	dr = defrtrlist_update(&dr0);
291     }
292 
293 	/*
294 	 * prefix
295 	 */
296 	if (ndopts.nd_opts_pi) {
297 		struct nd_opt_hdr *pt;
298 		struct nd_opt_prefix_info *pi = NULL;
299 		struct nd_prefix pr;
300 
301 		for (pt = (struct nd_opt_hdr *)ndopts.nd_opts_pi;
302 		     pt <= (struct nd_opt_hdr *)ndopts.nd_opts_pi_end;
303 		     pt = (struct nd_opt_hdr *)((caddr_t)pt +
304 						(pt->nd_opt_len << 3))) {
305 			if (pt->nd_opt_type != ND_OPT_PREFIX_INFORMATION)
306 				continue;
307 			pi = (struct nd_opt_prefix_info *)pt;
308 
309 			if (pi->nd_opt_pi_len != 4) {
310 				nd6log((LOG_INFO,
311 				    "nd6_ra_input: invalid option "
312 				    "len %d for prefix information option, "
313 				    "ignored\n", pi->nd_opt_pi_len));
314 				continue;
315 			}
316 
317 			if (128 < pi->nd_opt_pi_prefix_len) {
318 				nd6log((LOG_INFO,
319 				    "nd6_ra_input: invalid prefix "
320 				    "len %d for prefix information option, "
321 				    "ignored\n", pi->nd_opt_pi_prefix_len));
322 				continue;
323 			}
324 
325 			if (IN6_IS_ADDR_MULTICAST(&pi->nd_opt_pi_prefix)
326 			 || IN6_IS_ADDR_LINKLOCAL(&pi->nd_opt_pi_prefix)) {
327 				nd6log((LOG_INFO,
328 				    "nd6_ra_input: invalid prefix "
329 				    "%s, ignored\n",
330 				    ip6_sprintf(&pi->nd_opt_pi_prefix)));
331 				continue;
332 			}
333 
334 			/* aggregatable unicast address, rfc2374 */
335 			if ((pi->nd_opt_pi_prefix.s6_addr8[0] & 0xe0) == 0x20
336 			 && pi->nd_opt_pi_prefix_len != 64) {
337 				nd6log((LOG_INFO,
338 				    "nd6_ra_input: invalid prefixlen "
339 				    "%d for rfc2374 prefix %s, ignored\n",
340 				    pi->nd_opt_pi_prefix_len,
341 				    ip6_sprintf(&pi->nd_opt_pi_prefix)));
342 				continue;
343 			}
344 
345 			bzero(&pr, sizeof(pr));
346 			pr.ndpr_prefix.sin6_family = AF_INET6;
347 			pr.ndpr_prefix.sin6_len = sizeof(pr.ndpr_prefix);
348 			pr.ndpr_prefix.sin6_addr = pi->nd_opt_pi_prefix;
349 			pr.ndpr_ifp = (struct ifnet *)m->m_pkthdr.rcvif;
350 
351 			pr.ndpr_raf_onlink = (pi->nd_opt_pi_flags_reserved &
352 					      ND_OPT_PI_FLAG_ONLINK) ? 1 : 0;
353 			pr.ndpr_raf_auto = (pi->nd_opt_pi_flags_reserved &
354 					    ND_OPT_PI_FLAG_AUTO) ? 1 : 0;
355 			pr.ndpr_plen = pi->nd_opt_pi_prefix_len;
356 			pr.ndpr_vltime = ntohl(pi->nd_opt_pi_valid_time);
357 			pr.ndpr_pltime =
358 				ntohl(pi->nd_opt_pi_preferred_time);
359 
360 			if (in6_init_prefix_ltimes(&pr))
361 				continue; /* prefix lifetime init failed */
362 
363 			prelist_update(&pr, dr, m);
364 		}
365 	}
366 
367 	/*
368 	 * MTU
369 	 */
370 	if (ndopts.nd_opts_mtu && ndopts.nd_opts_mtu->nd_opt_mtu_len == 1) {
371 		u_int32_t mtu = ntohl(ndopts.nd_opts_mtu->nd_opt_mtu_mtu);
372 
373 		/* lower bound */
374 		if (mtu < IPV6_MMTU) {
375 			nd6log((LOG_INFO, "nd6_ra_input: bogus mtu option "
376 			    "mtu=%d sent from %s, ignoring\n",
377 			    mtu, ip6_sprintf(&ip6->ip6_src)));
378 			goto skip;
379 		}
380 
381 		/* upper bound */
382 		if (ndi->maxmtu) {
383 			if (mtu <= ndi->maxmtu) {
384 				int change = (ndi->linkmtu != mtu);
385 
386 				ndi->linkmtu = mtu;
387 				if (change) /* in6_maxmtu may change */
388 					in6_setmaxmtu();
389 			} else {
390 				nd6log((LOG_INFO, "nd6_ra_input: bogus mtu "
391 				    "mtu=%d sent from %s; "
392 				    "exceeds maxmtu %d, ignoring\n",
393 				    mtu, ip6_sprintf(&ip6->ip6_src),
394 				    ndi->maxmtu));
395 			}
396 		} else {
397 			nd6log((LOG_INFO, "nd6_ra_input: mtu option "
398 			    "mtu=%d sent from %s; maxmtu unknown, "
399 			    "ignoring\n",
400 			    mtu, ip6_sprintf(&ip6->ip6_src)));
401 		}
402 	}
403 
404 skip:
405 
406 	/*
407 	 * Source link layer address
408 	 */
409     {
410 	char *lladdr = NULL;
411 	int lladdrlen = 0;
412 
413 	if (ndopts.nd_opts_src_lladdr) {
414 		lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1);
415 		lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3;
416 	}
417 
418 	if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
419 		nd6log((LOG_INFO,
420 		    "nd6_ra_input: lladdrlen mismatch for %s "
421 		    "(if %d, RA packet %d)\n",
422 			ip6_sprintf(&saddr6), ifp->if_addrlen, lladdrlen - 2));
423 		goto bad;
424 	}
425 
426 	nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, ND_ROUTER_ADVERT, 0);
427 
428 	/*
429 	 * Installing a link-layer address might change the state of the
430 	 * router's neighbor cache, which might also affect our on-link
431 	 * detection of adveritsed prefixes.
432 	 */
433 	pfxlist_onlink_check();
434     }
435 
436 freeit:
437 	m_freem(m);
438 	return;
439 
440 bad:
441 	icmp6stat.icp6s_badra++;
442 	m_freem(m);
443 }
444 
445 /*
446  * default router list proccessing sub routines
447  */
448 
449 /* tell the change to user processes watching the routing socket. */
450 static void
451 nd6_rtmsg(int cmd, struct rtentry *rt)
452 {
453 	struct rt_addrinfo info;
454 
455 	bzero((caddr_t)&info, sizeof(info));
456 	info.rti_info[RTAX_DST] = rt_key(rt);
457 	info.rti_info[RTAX_GATEWAY] = rt->rt_gateway;
458 	info.rti_info[RTAX_NETMASK] = rt_mask(rt);
459 	info.rti_info[RTAX_IFP] =
460 		(struct sockaddr *)TAILQ_FIRST(&rt->rt_ifp->if_addrlist);
461 	info.rti_info[RTAX_IFA] = rt->rt_ifa->ifa_addr;
462 
463 	rt_missmsg(cmd, &info, rt->rt_flags, 0);
464 }
465 
466 void
467 defrouter_addreq(struct nd_defrouter *new)
468 {
469 	struct sockaddr_in6 def, mask, gate;
470 	struct rtentry *newrt = NULL;
471 
472 	bzero(&def, sizeof(def));
473 	bzero(&mask, sizeof(mask));
474 	bzero(&gate, sizeof(gate));
475 
476 	def.sin6_len = mask.sin6_len = gate.sin6_len
477 		= sizeof(struct sockaddr_in6);
478 	def.sin6_family = mask.sin6_family = gate.sin6_family = AF_INET6;
479 	gate.sin6_addr = new->rtaddr;
480 
481 	crit_enter();
482 	rtrequest(RTM_ADD, (struct sockaddr *)&def, (struct sockaddr *)&gate,
483 		  (struct sockaddr *)&mask, RTF_GATEWAY, &newrt);
484 	if (newrt) {
485 		nd6_rtmsg(RTM_ADD, newrt); /* tell user process */
486 		newrt->rt_refcnt--;
487 	}
488 	crit_exit();
489 	return;
490 }
491 
492 /* Add a route to a given interface as default */
493 void
494 defrouter_addifreq(struct ifnet *ifp)
495 {
496 	struct sockaddr_in6 def, mask;
497 	struct ifaddr *ifa;
498 	struct rtentry *newrt = NULL;
499 	int error, flags;
500 
501 	bzero(&def, sizeof(def));
502 	bzero(&mask, sizeof(mask));
503 
504 	def.sin6_len = mask.sin6_len = sizeof(struct sockaddr_in6);
505 	def.sin6_family = mask.sin6_family = AF_INET6;
506 
507 	/*
508 	 * Search for an ifaddr beloging to the specified interface.
509 	 * XXX: An IPv6 address are required to be assigned on the interface.
510 	 */
511 	if ((ifa = ifaof_ifpforaddr((struct sockaddr *)&def, ifp)) == NULL) {
512 		nd6log((LOG_ERR,	/* better error? */
513 		    "defrouter_addifreq: failed to find an ifaddr "
514 		    "to install a route to interface %s\n",
515 		    if_name(ifp)));
516 		return;
517 	}
518 
519 	flags = ifa->ifa_flags;
520 	error = rtrequest(RTM_ADD, (struct sockaddr *)&def, ifa->ifa_addr,
521 			  (struct sockaddr *)&mask, flags, &newrt);
522 	if (error != 0) {
523 		nd6log((LOG_ERR,
524 		    "defrouter_addifreq: failed to install a route to "
525 		    "interface %s (errno = %d)\n",
526 		    if_name(ifp), error));
527 
528 		if (newrt)	/* maybe unnecessary, but do it for safety */
529 			newrt->rt_refcnt--;
530 	} else {
531 		if (newrt) {
532 			nd6_rtmsg(RTM_ADD, newrt);
533 			newrt->rt_refcnt--;
534 		}
535 	}
536 }
537 
538 struct nd_defrouter *
539 defrouter_lookup(struct in6_addr *addr, struct ifnet *ifp)
540 {
541 	struct nd_defrouter *dr;
542 
543 	for (dr = TAILQ_FIRST(&nd_defrouter); dr;
544 	     dr = TAILQ_NEXT(dr, dr_entry)) {
545 		if (dr->ifp == ifp && IN6_ARE_ADDR_EQUAL(addr, &dr->rtaddr))
546 			return (dr);
547 	}
548 
549 	return (NULL);		/* search failed */
550 }
551 
552 void
553 defrouter_delreq(struct nd_defrouter *dr, int dofree)
554 {
555 	struct sockaddr_in6 def, mask, gate;
556 	struct rtentry *oldrt = NULL;
557 
558 	bzero(&def, sizeof(def));
559 	bzero(&mask, sizeof(mask));
560 	bzero(&gate, sizeof(gate));
561 
562 	def.sin6_len = mask.sin6_len = gate.sin6_len
563 		= sizeof(struct sockaddr_in6);
564 	def.sin6_family = mask.sin6_family = gate.sin6_family = AF_INET6;
565 	gate.sin6_addr = dr->rtaddr;
566 
567 	rtrequest(RTM_DELETE, (struct sockaddr *)&def,
568 		  (struct sockaddr *)&gate,
569 		  (struct sockaddr *)&mask,
570 		  RTF_GATEWAY, &oldrt);
571 	if (oldrt) {
572 		nd6_rtmsg(RTM_DELETE, oldrt);
573 		if (oldrt->rt_refcnt <= 0) {
574 			/*
575 			 * XXX: borrowed from the RTM_DELETE case of
576 			 * rtrequest().
577 			 */
578 			oldrt->rt_refcnt++;
579 			rtfree(oldrt);
580 		}
581 	}
582 
583 	if (dofree)		/* XXX: necessary? */
584 		kfree(dr, M_IP6NDP);
585 }
586 
587 void
588 defrtrlist_del(struct nd_defrouter *dr)
589 {
590 	struct nd_defrouter *deldr = NULL;
591 	struct nd_prefix *pr;
592 
593 	/*
594 	 * Flush all the routing table entries that use the router
595 	 * as a next hop.
596 	 */
597 	if (!ip6_forwarding && ip6_accept_rtadv) {
598 		/* above is a good condition? */
599 		rt6_flush(&dr->rtaddr, dr->ifp);
600 	}
601 
602 	if (dr == TAILQ_FIRST(&nd_defrouter))
603 		deldr = dr;	/* The router is primary. */
604 
605 	TAILQ_REMOVE(&nd_defrouter, dr, dr_entry);
606 
607 	/*
608 	 * Also delete all the pointers to the router in each prefix lists.
609 	 */
610 	for (pr = nd_prefix.lh_first; pr; pr = pr->ndpr_next) {
611 		struct nd_pfxrouter *pfxrtr;
612 		if ((pfxrtr = pfxrtr_lookup(pr, dr)) != NULL)
613 			pfxrtr_del(pfxrtr);
614 	}
615 	pfxlist_onlink_check();
616 
617 	/*
618 	 * If the router is the primary one, choose a new one.
619 	 * Note that defrouter_select() will remove the current gateway
620 	 * from the routing table.
621 	 */
622 	if (deldr)
623 		defrouter_select();
624 
625 	kfree(dr, M_IP6NDP);
626 }
627 
628 /*
629  * Default Router Selection according to Section 6.3.6 of RFC 2461:
630  * 1) Routers that are reachable or probably reachable should be
631  *    preferred.
632  * 2) When no routers on the list are known to be reachable or
633  *    probably reachable, routers SHOULD be selected in a round-robin
634  *    fashion.
635  * 3) If the Default Router List is empty, assume that all
636  *    destinations are on-link.
637  */
638 void
639 defrouter_select(void)
640 {
641 	struct nd_defrouter *dr, anydr;
642 	struct rtentry *rt = NULL;
643 	struct llinfo_nd6 *ln = NULL;
644 
645 	crit_enter();
646 
647 	/*
648 	 * Search for a (probably) reachable router from the list.
649 	 */
650 	for (dr = TAILQ_FIRST(&nd_defrouter); dr;
651 	     dr = TAILQ_NEXT(dr, dr_entry)) {
652 		if ((rt = nd6_lookup(&dr->rtaddr, 0, dr->ifp)) &&
653 		    (ln = (struct llinfo_nd6 *)rt->rt_llinfo) &&
654 		    ND6_IS_LLINFO_PROBREACH(ln)) {
655 			/* Got it, and move it to the head */
656 			TAILQ_REMOVE(&nd_defrouter, dr, dr_entry);
657 			TAILQ_INSERT_HEAD(&nd_defrouter, dr, dr_entry);
658 			break;
659 		}
660 	}
661 
662 	if ((dr = TAILQ_FIRST(&nd_defrouter))) {
663 		/*
664 		 * De-install the previous default gateway and install
665 		 * a new one.
666 		 * Note that if there is no reachable router in the list,
667 		 * the head entry will be used anyway.
668 		 * XXX: do we have to check the current routing table entry?
669 		 */
670 		bzero(&anydr, sizeof(anydr));
671 		defrouter_delreq(&anydr, 0);
672 		defrouter_addreq(dr);
673 	}
674 	else {
675 		/*
676 		 * The Default Router List is empty, so install the default
677 		 * route to an inteface.
678 		 * XXX: The specification does not say this mechanism should
679 		 * be restricted to hosts, but this would be not useful
680 		 * (even harmful) for routers.
681 		 */
682 		if (!ip6_forwarding) {
683 			/*
684 			 * De-install the current default route
685 			 * in advance.
686 			 */
687 			bzero(&anydr, sizeof(anydr));
688 			defrouter_delreq(&anydr, 0);
689 			if (nd6_defifp) {
690 				/*
691 				 * Install a route to the default interface
692 				 * as default route.
693 				 * XXX: we enable this for host only, because
694 				 * this may override a default route installed
695 				 * a user process (e.g. routing daemon) in a
696 				 * router case.
697 				 */
698 				defrouter_addifreq(nd6_defifp);
699 			} else {
700 				nd6log((LOG_INFO, "defrouter_select: "
701 				    "there's no default router and no default"
702 				    " interface\n"));
703 			}
704 		}
705 	}
706 
707 	crit_exit();
708 	return;
709 }
710 
711 static struct nd_defrouter *
712 defrtrlist_update(struct nd_defrouter *new)
713 {
714 	struct nd_defrouter *dr, *n;
715 
716 	crit_enter();
717 
718 	if ((dr = defrouter_lookup(&new->rtaddr, new->ifp)) != NULL) {
719 		/* entry exists */
720 		if (new->rtlifetime == 0) {
721 			defrtrlist_del(dr);
722 			dr = NULL;
723 		} else {
724 			/* override */
725 			dr->flags = new->flags; /* xxx flag check */
726 			dr->rtlifetime = new->rtlifetime;
727 			dr->expire = new->expire;
728 		}
729 		crit_exit();
730 		return (dr);
731 	}
732 
733 	/* entry does not exist */
734 	if (new->rtlifetime == 0) {
735 		crit_exit();
736 		return (NULL);
737 	}
738 
739 	n = (struct nd_defrouter *)kmalloc(sizeof(*n), M_IP6NDP,
740 	    M_NOWAIT | M_ZERO);
741 	if (n == NULL) {
742 		crit_exit();
743 		return (NULL);
744 	}
745 	*n = *new;
746 
747 	/*
748 	 * Insert the new router at the end of the Default Router List.
749 	 * If there is no other router, install it anyway. Otherwise,
750 	 * just continue to use the current default router.
751 	 */
752 	TAILQ_INSERT_TAIL(&nd_defrouter, n, dr_entry);
753 	if (TAILQ_FIRST(&nd_defrouter) == n)
754 		defrouter_select();
755 	crit_exit();
756 	return (n);
757 }
758 
759 static struct nd_pfxrouter *
760 pfxrtr_lookup(struct nd_prefix *pr, struct nd_defrouter *dr)
761 {
762 	struct nd_pfxrouter *search;
763 
764 	for (search = pr->ndpr_advrtrs.lh_first; search; search = search->pfr_next) {
765 		if (search->router == dr)
766 			break;
767 	}
768 
769 	return (search);
770 }
771 
772 static void
773 pfxrtr_add(struct nd_prefix *pr, struct nd_defrouter *dr)
774 {
775 	struct nd_pfxrouter *new;
776 
777 	new = (struct nd_pfxrouter *)kmalloc(sizeof(*new), M_IP6NDP,
778 	    M_NOWAIT | M_ZERO);
779 	if (new == NULL)
780 		return;
781 	new->router = dr;
782 
783 	LIST_INSERT_HEAD(&pr->ndpr_advrtrs, new, pfr_entry);
784 
785 	pfxlist_onlink_check();
786 }
787 
788 static void
789 pfxrtr_del(struct nd_pfxrouter *pfr)
790 {
791 	LIST_REMOVE(pfr, pfr_entry);
792 	kfree(pfr, M_IP6NDP);
793 }
794 
795 struct nd_prefix *
796 nd6_prefix_lookup(struct nd_prefix *pr)
797 {
798 	struct nd_prefix *search;
799 
800 	for (search = nd_prefix.lh_first; search; search = search->ndpr_next) {
801 		if (pr->ndpr_ifp == search->ndpr_ifp &&
802 		    pr->ndpr_plen == search->ndpr_plen &&
803 		    in6_are_prefix_equal(&pr->ndpr_prefix.sin6_addr,
804 					 &search->ndpr_prefix.sin6_addr,
805 					 pr->ndpr_plen)
806 		    ) {
807 			break;
808 		}
809 	}
810 
811 	return (search);
812 }
813 
814 int
815 nd6_prelist_add(struct nd_prefix *pr, struct nd_defrouter *dr,
816 		struct nd_prefix **newp)
817 {
818 	struct nd_prefix *new = NULL;
819 	int i;
820 
821 	new = (struct nd_prefix *)kmalloc(sizeof(*new), M_IP6NDP,
822 	    M_NOWAIT | M_ZERO);
823 	if (new == NULL)
824 		return ENOMEM;
825 	*new = *pr;
826 	if (newp != NULL)
827 		*newp = new;
828 
829 	/* initilization */
830 	LIST_INIT(&new->ndpr_advrtrs);
831 	in6_prefixlen2mask(&new->ndpr_mask, new->ndpr_plen);
832 	/* make prefix in the canonical form */
833 	for (i = 0; i < 4; i++)
834 		new->ndpr_prefix.sin6_addr.s6_addr32[i] &=
835 			new->ndpr_mask.s6_addr32[i];
836 
837 	crit_enter();
838 	/* link ndpr_entry to nd_prefix list */
839 	LIST_INSERT_HEAD(&nd_prefix, new, ndpr_entry);
840 	crit_exit();
841 
842 	/* ND_OPT_PI_FLAG_ONLINK processing */
843 	if (new->ndpr_raf_onlink) {
844 		int e;
845 
846 		if ((e = nd6_prefix_onlink(new)) != 0) {
847 			nd6log((LOG_ERR, "nd6_prelist_add: failed to make "
848 			    "the prefix %s/%d on-link on %s (errno=%d)\n",
849 			    ip6_sprintf(&pr->ndpr_prefix.sin6_addr),
850 			    pr->ndpr_plen, if_name(pr->ndpr_ifp), e));
851 			/* proceed anyway. XXX: is it correct? */
852 		}
853 	}
854 
855 	if (dr) {
856 		pfxrtr_add(new, dr);
857 	}
858 
859 	return 0;
860 }
861 
862 void
863 prelist_remove(struct nd_prefix *pr)
864 {
865 	struct nd_pfxrouter *pfr, *next;
866 	int e;
867 
868 	/* make sure to invalidate the prefix until it is really freed. */
869 	pr->ndpr_vltime = 0;
870 	pr->ndpr_pltime = 0;
871 #if 0
872 	/*
873 	 * Though these flags are now meaningless, we'd rather keep the value
874 	 * not to confuse users when executing "ndp -p".
875 	 */
876 	pr->ndpr_raf_onlink = 0;
877 	pr->ndpr_raf_auto = 0;
878 #endif
879 	if ((pr->ndpr_stateflags & NDPRF_ONLINK) &&
880 	    (e = nd6_prefix_offlink(pr)) != 0) {
881 		nd6log((LOG_ERR, "prelist_remove: failed to make %s/%d offlink "
882 		    "on %s, errno=%d\n",
883 		    ip6_sprintf(&pr->ndpr_prefix.sin6_addr),
884 		    pr->ndpr_plen, if_name(pr->ndpr_ifp), e));
885 		/* what should we do? */
886 	}
887 
888 	if (pr->ndpr_refcnt > 0)
889 		return;		/* notice here? */
890 
891 	crit_enter();
892 
893 	/* unlink ndpr_entry from nd_prefix list */
894 	LIST_REMOVE(pr, ndpr_entry);
895 
896 	/* free list of routers that adversed the prefix */
897 	for (pfr = pr->ndpr_advrtrs.lh_first; pfr; pfr = next) {
898 		next = pfr->pfr_next;
899 
900 		kfree(pfr, M_IP6NDP);
901 	}
902 	crit_exit();
903 
904 	kfree(pr, M_IP6NDP);
905 
906 	pfxlist_onlink_check();
907 }
908 
909 /*
910  * Parameters:
911  *	dr:	may be NULL
912  */
913 int
914 prelist_update(struct nd_prefix *new, struct nd_defrouter *dr, struct mbuf *m)
915 {
916 	struct in6_ifaddr *ia6 = NULL, *ia6_match = NULL;
917 	struct ifaddr *ifa;
918 	struct ifnet *ifp = new->ndpr_ifp;
919 	struct nd_prefix *pr;
920 	int error = 0;
921 	int newprefix = 0;
922 	int auth;
923 	struct in6_addrlifetime lt6_tmp;
924 
925 	auth = 0;
926 	crit_enter();
927 	if (m) {
928 		/*
929 		 * Authenticity for NA consists authentication for
930 		 * both IP header and IP datagrams, doesn't it ?
931 		 */
932 #if defined(M_AUTHIPHDR) && defined(M_AUTHIPDGM)
933 		auth = (m->m_flags & M_AUTHIPHDR
934 		     && m->m_flags & M_AUTHIPDGM) ? 1 : 0;
935 #endif
936 	}
937 
938 
939 	if ((pr = nd6_prefix_lookup(new)) != NULL) {
940 		/*
941 		 * nd6_prefix_lookup() ensures that pr and new have the same
942 		 * prefix on a same interface.
943 		 */
944 
945 		/*
946 		 * Update prefix information.  Note that the on-link (L) bit
947 		 * and the autonomous (A) bit should NOT be changed from 1
948 		 * to 0.
949 		 */
950 		if (new->ndpr_raf_onlink == 1)
951 			pr->ndpr_raf_onlink = 1;
952 		if (new->ndpr_raf_auto == 1)
953 			pr->ndpr_raf_auto = 1;
954 		if (new->ndpr_raf_onlink) {
955 			pr->ndpr_vltime = new->ndpr_vltime;
956 			pr->ndpr_pltime = new->ndpr_pltime;
957 			pr->ndpr_preferred = new->ndpr_preferred;
958 			pr->ndpr_expire = new->ndpr_expire;
959 		}
960 
961 		if (new->ndpr_raf_onlink &&
962 		    !(pr->ndpr_stateflags & NDPRF_ONLINK)) {
963 			int e;
964 
965 			if ((e = nd6_prefix_onlink(pr)) != 0) {
966 				nd6log((LOG_ERR,
967 				    "prelist_update: failed to make "
968 				    "the prefix %s/%d on-link on %s "
969 				    "(errno=%d)\n",
970 				    ip6_sprintf(&pr->ndpr_prefix.sin6_addr),
971 				    pr->ndpr_plen, if_name(pr->ndpr_ifp), e));
972 				/* proceed anyway. XXX: is it correct? */
973 			}
974 		}
975 
976 		if (dr && pfxrtr_lookup(pr, dr) == NULL)
977 			pfxrtr_add(pr, dr);
978 	} else {
979 		struct nd_prefix *newpr = NULL;
980 
981 		newprefix = 1;
982 
983 		if (new->ndpr_vltime == 0)
984 			goto end;
985 		if (new->ndpr_raf_onlink == 0 && new->ndpr_raf_auto == 0)
986 			goto end;
987 
988 		bzero(&new->ndpr_addr, sizeof(struct in6_addr));
989 
990 		error = nd6_prelist_add(new, dr, &newpr);
991 		if (error != 0 || newpr == NULL) {
992 			nd6log((LOG_NOTICE, "prelist_update: "
993 			    "nd6_prelist_add failed for %s/%d on %s "
994 			    "errno=%d, returnpr=%p\n",
995 			    ip6_sprintf(&new->ndpr_prefix.sin6_addr),
996 					new->ndpr_plen, if_name(new->ndpr_ifp),
997 					error, newpr));
998 			goto end; /* we should just give up in this case. */
999 		}
1000 
1001 		/*
1002 		 * XXX: from the ND point of view, we can ignore a prefix
1003 		 * with the on-link bit being zero.  However, we need a
1004 		 * prefix structure for references from autoconfigured
1005 		 * addresses.  Thus, we explicitly make suret that the prefix
1006 		 * itself expires now.
1007 		 */
1008 		if (newpr->ndpr_raf_onlink == 0) {
1009 			newpr->ndpr_vltime = 0;
1010 			newpr->ndpr_pltime = 0;
1011 			in6_init_prefix_ltimes(newpr);
1012 		}
1013 
1014 		pr = newpr;
1015 	}
1016 
1017 	/*
1018 	 * Address autoconfiguration based on Section 5.5.3 of RFC 2462.
1019 	 * Note that pr must be non NULL at this point.
1020 	 */
1021 
1022 	/* 5.5.3 (a). Ignore the prefix without the A bit set. */
1023 	if (!new->ndpr_raf_auto)
1024 		goto afteraddrconf;
1025 
1026 	/*
1027 	 * 5.5.3 (b). the link-local prefix should have been ignored in
1028 	 * nd6_ra_input.
1029 	 */
1030 
1031 	/*
1032 	 * 5.5.3 (c). Consistency check on lifetimes: pltime <= vltime.
1033 	 * This should have been done in nd6_ra_input.
1034 	 */
1035 
1036  	/*
1037 	 * 5.5.3 (d). If the prefix advertised does not match the prefix of an
1038 	 * address already in the list, and the Valid Lifetime is not 0,
1039 	 * form an address.  Note that even a manually configured address
1040 	 * should reject autoconfiguration of a new address.
1041 	 */
1042 	TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list)
1043 	{
1044 		struct in6_ifaddr *ifa6;
1045 		int ifa_plen;
1046 		u_int32_t storedlifetime;
1047 
1048 		if (ifa->ifa_addr->sa_family != AF_INET6)
1049 			continue;
1050 
1051 		ifa6 = (struct in6_ifaddr *)ifa;
1052 
1053 		/*
1054 		 * Spec is not clear here, but I believe we should concentrate
1055 		 * on unicast (i.e. not anycast) addresses.
1056 		 * XXX: other ia6_flags? detached or duplicated?
1057 		 */
1058 		if (ifa6->ia6_flags & IN6_IFF_ANYCAST)
1059 			continue;
1060 
1061 		ifa_plen = in6_mask2len(&ifa6->ia_prefixmask.sin6_addr, NULL);
1062 		if (ifa_plen != new->ndpr_plen ||
1063 		    !in6_are_prefix_equal(&ifa6->ia_addr.sin6_addr,
1064 					  &new->ndpr_prefix.sin6_addr,
1065 					  ifa_plen))
1066 			continue;
1067 
1068 		if (ia6_match == NULL) /* remember the first one */
1069 			ia6_match = ifa6;
1070 
1071 		if (!(ifa6->ia6_flags & IN6_IFF_AUTOCONF))
1072 			continue;
1073 
1074 		/*
1075 		 * An already autoconfigured address matched.  Now that we
1076 		 * are sure there is at least one matched address, we can
1077 		 * proceed to 5.5.3. (e): update the lifetimes according to the
1078 		 * "two hours" rule and the privacy extension.
1079 		 */
1080 #define TWOHOUR		(120*60)
1081 		lt6_tmp = ifa6->ia6_lifetime;
1082 
1083 		if (lt6_tmp.ia6t_vltime == ND6_INFINITE_LIFETIME)
1084 			storedlifetime = ND6_INFINITE_LIFETIME;
1085 		else if (IFA6_IS_INVALID(ifa6))
1086 			storedlifetime = 0;
1087 		else
1088 			storedlifetime = lt6_tmp.ia6t_expire - time_second;
1089 
1090 		/* when not updating, keep the current stored lifetime. */
1091 		lt6_tmp.ia6t_vltime = storedlifetime;
1092 
1093 		if (TWOHOUR < new->ndpr_vltime ||
1094 		    storedlifetime < new->ndpr_vltime) {
1095 			lt6_tmp.ia6t_vltime = new->ndpr_vltime;
1096 		} else if (storedlifetime <= TWOHOUR
1097 #if 0
1098 			   /*
1099 			    * This condition is logically redundant, so we just
1100 			    * omit it.
1101 			    * See IPng 6712, 6717, and 6721.
1102 			    */
1103 			   && new->ndpr_vltime <= storedlifetime
1104 #endif
1105 			) {
1106 			if (auth) {
1107 				lt6_tmp.ia6t_vltime = new->ndpr_vltime;
1108 			}
1109 		} else {
1110 			/*
1111 			 * new->ndpr_vltime <= TWOHOUR &&
1112 			 * TWOHOUR < storedlifetime
1113 			 */
1114 			lt6_tmp.ia6t_vltime = TWOHOUR;
1115 		}
1116 
1117 		/* The 2 hour rule is not imposed for preferred lifetime. */
1118 		lt6_tmp.ia6t_pltime = new->ndpr_pltime;
1119 
1120 		in6_init_address_ltimes(pr, &lt6_tmp);
1121 
1122 		/*
1123 		 * When adjusting the lifetimes of an existing temporary
1124 		 * address, only lower the lifetimes.
1125 		 * RFC 3041 3.3. (1).
1126 		 * XXX: how should we modify ia6t_[pv]ltime?
1127 		 */
1128 		if (ifa6->ia6_flags & IN6_IFF_TEMPORARY) {
1129 			if (lt6_tmp.ia6t_expire == 0 || /* no expire */
1130 			    lt6_tmp.ia6t_expire >
1131 			    ifa6->ia6_lifetime.ia6t_expire) {
1132 				lt6_tmp.ia6t_expire =
1133 					ifa6->ia6_lifetime.ia6t_expire;
1134 			}
1135 			if (lt6_tmp.ia6t_preferred == 0 || /* no expire */
1136 			    lt6_tmp.ia6t_preferred >
1137 			    ifa6->ia6_lifetime.ia6t_preferred) {
1138 				lt6_tmp.ia6t_preferred =
1139 					ifa6->ia6_lifetime.ia6t_preferred;
1140 			}
1141 		}
1142 
1143 		ifa6->ia6_lifetime = lt6_tmp;
1144 	}
1145 	if (ia6_match == NULL && new->ndpr_vltime) {
1146 		/*
1147 		 * No address matched and the valid lifetime is non-zero.
1148 		 * Create a new address.
1149 		 */
1150 		if ((ia6 = in6_ifadd(new, NULL)) != NULL) {
1151 			/*
1152 			 * note that we should use pr (not new) for reference.
1153 			 */
1154 			pr->ndpr_refcnt++;
1155 			ia6->ia6_ndpr = pr;
1156 
1157 #if 0
1158 			/* XXXYYY Don't do this, according to Jinmei. */
1159 			pr->ndpr_addr = new->ndpr_addr;
1160 #endif
1161 
1162 			/*
1163 			 * RFC 3041 3.3 (2).
1164 			 * When a new public address is created as described
1165 			 * in RFC2462, also create a new temporary address.
1166 			 *
1167 			 * RFC 3041 3.5.
1168 			 * When an interface connects to a new link, a new
1169 			 * randomized interface identifier should be generated
1170 			 * immediately together with a new set of temporary
1171 			 * addresses.  Thus, we specifiy 1 as the 2nd arg of
1172 			 * in6_tmpifadd().
1173 			 */
1174 			if (ip6_use_tempaddr) {
1175 				int e;
1176 				if ((e = in6_tmpifadd(ia6, 1)) != 0) {
1177 					nd6log((LOG_NOTICE, "prelist_update: "
1178 					    "failed to create a temporary "
1179 					    "address, errno=%d\n",
1180 					    e));
1181 				}
1182 			}
1183 
1184 			/*
1185 			 * A newly added address might affect the status
1186 			 * of other addresses, so we check and update it.
1187 			 * XXX: what if address duplication happens?
1188 			 */
1189 			pfxlist_onlink_check();
1190 		} else {
1191 			/* just set an error. do not bark here. */
1192 			error = EADDRNOTAVAIL; /* XXX: might be unused. */
1193 		}
1194 	}
1195 
1196 afteraddrconf:
1197 
1198 end:
1199 	crit_exit();
1200 	return error;
1201 }
1202 
1203 /*
1204  * A supplement function used in the on-link detection below;
1205  * detect if a given prefix has a (probably) reachable advertising router.
1206  * XXX: lengthy function name...
1207  */
1208 static struct nd_pfxrouter *
1209 find_pfxlist_reachable_router(struct nd_prefix *pr)
1210 {
1211 	struct nd_pfxrouter *pfxrtr;
1212 	struct rtentry *rt;
1213 	struct llinfo_nd6 *ln;
1214 
1215 	for (pfxrtr = LIST_FIRST(&pr->ndpr_advrtrs); pfxrtr;
1216 	     pfxrtr = LIST_NEXT(pfxrtr, pfr_entry)) {
1217 		if ((rt = nd6_lookup(&pfxrtr->router->rtaddr, 0,
1218 				     pfxrtr->router->ifp)) &&
1219 		    (ln = (struct llinfo_nd6 *)rt->rt_llinfo) &&
1220 		    ND6_IS_LLINFO_PROBREACH(ln))
1221 			break;	/* found */
1222 	}
1223 
1224 	return (pfxrtr);
1225 
1226 }
1227 
1228 /*
1229  * Check if each prefix in the prefix list has at least one available router
1230  * that advertised the prefix (a router is "available" if its neighbor cache
1231  * entry is reachable or probably reachable).
1232  * If the check fails, the prefix may be off-link, because, for example,
1233  * we have moved from the network but the lifetime of the prefix has not
1234  * expired yet.  So we should not use the prefix if there is another prefix
1235  * that has an available router.
1236  * But, if there is no prefix that has an available router, we still regards
1237  * all the prefixes as on-link.  This is because we can't tell if all the
1238  * routers are simply dead or if we really moved from the network and there
1239  * is no router around us.
1240  */
1241 void
1242 pfxlist_onlink_check(void)
1243 {
1244 	struct nd_prefix *pr;
1245 	struct in6_ifaddr *ifa;
1246 
1247 	/*
1248 	 * Check if there is a prefix that has a reachable advertising
1249 	 * router.
1250 	 */
1251 	for (pr = nd_prefix.lh_first; pr; pr = pr->ndpr_next) {
1252 		if (pr->ndpr_raf_onlink && find_pfxlist_reachable_router(pr))
1253 			break;
1254 	}
1255 
1256 	if (pr) {
1257 		/*
1258 		 * There is at least one prefix that has a reachable router.
1259 		 * Detach prefixes which have no reachable advertising
1260 		 * router, and attach other prefixes.
1261 		 */
1262 		for (pr = nd_prefix.lh_first; pr; pr = pr->ndpr_next) {
1263 			/* XXX: a link-local prefix should never be detached */
1264 			if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr))
1265 				continue;
1266 
1267 			/*
1268 			 * we aren't interested in prefixes without the L bit
1269 			 * set.
1270 			 */
1271 			if (pr->ndpr_raf_onlink == 0)
1272 				continue;
1273 
1274 			if (!(pr->ndpr_stateflags & NDPRF_DETACHED) &&
1275 			    find_pfxlist_reachable_router(pr) == NULL)
1276 				pr->ndpr_stateflags |= NDPRF_DETACHED;
1277 			if ((pr->ndpr_stateflags & NDPRF_DETACHED) &&
1278 			    find_pfxlist_reachable_router(pr) != 0)
1279 				pr->ndpr_stateflags &= ~NDPRF_DETACHED;
1280 		}
1281 	} else {
1282 		/* there is no prefix that has a reachable router */
1283 		for (pr = nd_prefix.lh_first; pr; pr = pr->ndpr_next) {
1284 			if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr))
1285 				continue;
1286 
1287 			if (pr->ndpr_raf_onlink == 0)
1288 				continue;
1289 
1290 			if (pr->ndpr_stateflags & NDPRF_DETACHED)
1291 				pr->ndpr_stateflags &= ~NDPRF_DETACHED;
1292 		}
1293 	}
1294 
1295 	/*
1296 	 * Remove each interface route associated with a (just) detached
1297 	 * prefix, and reinstall the interface route for a (just) attached
1298 	 * prefix.  Note that all attempt of reinstallation does not
1299 	 * necessarily success, when a same prefix is shared among multiple
1300 	 * interfaces.  Such cases will be handled in nd6_prefix_onlink,
1301 	 * so we don't have to care about them.
1302 	 */
1303 	for (pr = nd_prefix.lh_first; pr; pr = pr->ndpr_next) {
1304 		int e;
1305 
1306 		if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr))
1307 			continue;
1308 
1309 		if (pr->ndpr_raf_onlink == 0)
1310 			continue;
1311 
1312 		if ((pr->ndpr_stateflags & NDPRF_DETACHED) &&
1313 		    (pr->ndpr_stateflags & NDPRF_ONLINK)) {
1314 			if ((e = nd6_prefix_offlink(pr)) != 0) {
1315 				nd6log((LOG_ERR,
1316 				    "pfxlist_onlink_check: failed to "
1317 				    "make %s/%d offlink, errno=%d\n",
1318 				    ip6_sprintf(&pr->ndpr_prefix.sin6_addr),
1319 				    pr->ndpr_plen, e));
1320 			}
1321 		}
1322 		if (!(pr->ndpr_stateflags & NDPRF_DETACHED) &&
1323 		    !(pr->ndpr_stateflags & NDPRF_ONLINK) &&
1324 		    pr->ndpr_raf_onlink) {
1325 			if ((e = nd6_prefix_onlink(pr)) != 0) {
1326 				nd6log((LOG_ERR,
1327 				    "pfxlist_onlink_check: failed to "
1328 				    "make %s/%d offlink, errno=%d\n",
1329 				    ip6_sprintf(&pr->ndpr_prefix.sin6_addr),
1330 				    pr->ndpr_plen, e));
1331 			}
1332 		}
1333 	}
1334 
1335 	/*
1336 	 * Changes on the prefix status might affect address status as well.
1337 	 * Make sure that all addresses derived from an attached prefix are
1338 	 * attached, and that all addresses derived from a detached prefix are
1339 	 * detached.  Note, however, that a manually configured address should
1340 	 * always be attached.
1341 	 * The precise detection logic is same as the one for prefixes.
1342 	 */
1343 	for (ifa = in6_ifaddr; ifa; ifa = ifa->ia_next) {
1344 		if (!(ifa->ia6_flags & IN6_IFF_AUTOCONF))
1345 			continue;
1346 
1347 		if (ifa->ia6_ndpr == NULL) {
1348 			/*
1349 			 * This can happen when we first configure the address
1350 			 * (i.e. the address exists, but the prefix does not).
1351 			 * XXX: complicated relationships...
1352 			 */
1353 			continue;
1354 		}
1355 
1356 		if (find_pfxlist_reachable_router(ifa->ia6_ndpr))
1357 			break;
1358 	}
1359 	if (ifa) {
1360 		for (ifa = in6_ifaddr; ifa; ifa = ifa->ia_next) {
1361 			if (!(ifa->ia6_flags & IN6_IFF_AUTOCONF))
1362 				continue;
1363 
1364 			if (ifa->ia6_ndpr == NULL) /* XXX: see above. */
1365 				continue;
1366 
1367 			if (find_pfxlist_reachable_router(ifa->ia6_ndpr))
1368 				ifa->ia6_flags &= ~IN6_IFF_DETACHED;
1369 			else
1370 				ifa->ia6_flags |= IN6_IFF_DETACHED;
1371 		}
1372 	}
1373 	else {
1374 		for (ifa = in6_ifaddr; ifa; ifa = ifa->ia_next) {
1375 			if (!(ifa->ia6_flags & IN6_IFF_AUTOCONF))
1376 				continue;
1377 
1378 			ifa->ia6_flags &= ~IN6_IFF_DETACHED;
1379 		}
1380 	}
1381 }
1382 
1383 int
1384 nd6_prefix_onlink(struct nd_prefix *pr)
1385 {
1386 	struct ifaddr *ifa;
1387 	struct ifnet *ifp = pr->ndpr_ifp;
1388 	struct sockaddr_in6 mask6;
1389 	struct nd_prefix *opr;
1390 	u_long rtflags;
1391 	int error = 0;
1392 	struct rtentry *rt = NULL;
1393 
1394 	/* sanity check */
1395 	if (pr->ndpr_stateflags & NDPRF_ONLINK) {
1396 		nd6log((LOG_ERR,
1397 		    "nd6_prefix_onlink: %s/%d is already on-link\n",
1398 		    ip6_sprintf(&pr->ndpr_prefix.sin6_addr), pr->ndpr_plen);
1399 		return (EEXIST));
1400 	}
1401 
1402 	/*
1403 	 * Add the interface route associated with the prefix.  Before
1404 	 * installing the route, check if there's the same prefix on another
1405 	 * interface, and the prefix has already installed the interface route.
1406 	 * Although such a configuration is expected to be rare, we explicitly
1407 	 * allow it.
1408 	 */
1409 	for (opr = nd_prefix.lh_first; opr; opr = opr->ndpr_next) {
1410 		if (opr == pr)
1411 			continue;
1412 
1413 		if (!(opr->ndpr_stateflags & NDPRF_ONLINK))
1414 			continue;
1415 
1416 		if (opr->ndpr_plen == pr->ndpr_plen &&
1417 		    in6_are_prefix_equal(&pr->ndpr_prefix.sin6_addr,
1418 					 &opr->ndpr_prefix.sin6_addr,
1419 					 pr->ndpr_plen))
1420 			return (0);
1421 	}
1422 
1423 	/*
1424 	 * We prefer link-local addresses as the associated interface address.
1425 	 */
1426 	/* search for a link-local addr */
1427 	ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp,
1428 						      IN6_IFF_NOTREADY|
1429 						      IN6_IFF_ANYCAST);
1430 	if (ifa == NULL) {
1431 		/* XXX: freebsd does not have ifa_ifwithaf */
1432 		TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list)
1433 		{
1434 			if (ifa->ifa_addr->sa_family == AF_INET6)
1435 				break;
1436 		}
1437 		/* should we care about ia6_flags? */
1438 	}
1439 	if (ifa == NULL) {
1440 		/*
1441 		 * This can still happen, when, for example, we receive an RA
1442 		 * containing a prefix with the L bit set and the A bit clear,
1443 		 * after removing all IPv6 addresses on the receiving
1444 		 * interface.  This should, of course, be rare though.
1445 		 */
1446 		nd6log((LOG_NOTICE,
1447 		    "nd6_prefix_onlink: failed to find any ifaddr"
1448 		    " to add route for a prefix(%s/%d) on %s\n",
1449 		    ip6_sprintf(&pr->ndpr_prefix.sin6_addr),
1450 		    pr->ndpr_plen, if_name(ifp)));
1451 		return (0);
1452 	}
1453 
1454 	/*
1455 	 * in6_ifinit() sets nd6_rtrequest to ifa_rtrequest for all ifaddrs.
1456 	 * ifa->ifa_rtrequest = nd6_rtrequest;
1457 	 */
1458 	bzero(&mask6, sizeof(mask6));
1459 	mask6.sin6_len = sizeof(mask6);
1460 	mask6.sin6_addr = pr->ndpr_mask;
1461 	rtflags = ifa->ifa_flags | RTF_CLONING | RTF_UP;
1462 	if (nd6_need_cache(ifp)) {
1463 		/* explicitly set in case ifa_flags does not set the flag. */
1464 		rtflags |= RTF_CLONING;
1465 	} else {
1466 		/*
1467 		 * explicitly clear the cloning bit in case ifa_flags sets it.
1468 		 */
1469 		rtflags &= ~RTF_CLONING;
1470 	}
1471 	error = rtrequest(RTM_ADD, (struct sockaddr *)&pr->ndpr_prefix,
1472 			  ifa->ifa_addr, (struct sockaddr *)&mask6,
1473 			  rtflags, &rt);
1474 	if (error == 0) {
1475 		if (rt != NULL) /* this should be non NULL, though */
1476 			nd6_rtmsg(RTM_ADD, rt);
1477 		pr->ndpr_stateflags |= NDPRF_ONLINK;
1478 	}
1479 	else {
1480 		nd6log((LOG_ERR, "nd6_prefix_onlink: failed to add route for a"
1481 		    " prefix (%s/%d) on %s, gw=%s, mask=%s, flags=%lx "
1482 		    "errno = %d\n",
1483 		    ip6_sprintf(&pr->ndpr_prefix.sin6_addr),
1484 		    pr->ndpr_plen, if_name(ifp),
1485 		    ip6_sprintf(&((struct sockaddr_in6 *)ifa->ifa_addr)->sin6_addr),
1486 		    ip6_sprintf(&mask6.sin6_addr), rtflags, error));
1487 	}
1488 
1489 	if (rt != NULL)
1490 		rt->rt_refcnt--;
1491 
1492 	return (error);
1493 }
1494 
1495 int
1496 nd6_prefix_offlink(struct nd_prefix *pr)
1497 {
1498 	int error = 0;
1499 	struct ifnet *ifp = pr->ndpr_ifp;
1500 	struct nd_prefix *opr;
1501 	struct sockaddr_in6 sa6, mask6;
1502 	struct rtentry *rt = NULL;
1503 
1504 	/* sanity check */
1505 	if (!(pr->ndpr_stateflags & NDPRF_ONLINK)) {
1506 		nd6log((LOG_ERR,
1507 		    "nd6_prefix_offlink: %s/%d is already off-link\n",
1508 		    ip6_sprintf(&pr->ndpr_prefix.sin6_addr), pr->ndpr_plen));
1509 		return (EEXIST);
1510 	}
1511 
1512 	bzero(&sa6, sizeof(sa6));
1513 	sa6.sin6_family = AF_INET6;
1514 	sa6.sin6_len = sizeof(sa6);
1515 	bcopy(&pr->ndpr_prefix.sin6_addr, &sa6.sin6_addr,
1516 	      sizeof(struct in6_addr));
1517 	bzero(&mask6, sizeof(mask6));
1518 	mask6.sin6_family = AF_INET6;
1519 	mask6.sin6_len = sizeof(sa6);
1520 	bcopy(&pr->ndpr_mask, &mask6.sin6_addr, sizeof(struct in6_addr));
1521 	error = rtrequest(RTM_DELETE, (struct sockaddr *)&sa6, NULL,
1522 			  (struct sockaddr *)&mask6, 0, &rt);
1523 	if (error == 0) {
1524 		pr->ndpr_stateflags &= ~NDPRF_ONLINK;
1525 
1526 		/* report the route deletion to the routing socket. */
1527 		if (rt != NULL)
1528 			nd6_rtmsg(RTM_DELETE, rt);
1529 
1530 		/*
1531 		 * There might be the same prefix on another interface,
1532 		 * the prefix which could not be on-link just because we have
1533 		 * the interface route (see comments in nd6_prefix_onlink).
1534 		 * If there's one, try to make the prefix on-link on the
1535 		 * interface.
1536 		 */
1537 		for (opr = nd_prefix.lh_first; opr; opr = opr->ndpr_next) {
1538 			if (opr == pr)
1539 				continue;
1540 
1541 			if (opr->ndpr_stateflags & NDPRF_ONLINK)
1542 				continue;
1543 
1544 			/*
1545 			 * KAME specific: detached prefixes should not be
1546 			 * on-link.
1547 			 */
1548 			if (opr->ndpr_stateflags & NDPRF_DETACHED)
1549 				continue;
1550 
1551 			if (opr->ndpr_plen == pr->ndpr_plen &&
1552 			    in6_are_prefix_equal(&pr->ndpr_prefix.sin6_addr,
1553 						 &opr->ndpr_prefix.sin6_addr,
1554 						 pr->ndpr_plen)) {
1555 				int e;
1556 
1557 				if ((e = nd6_prefix_onlink(opr)) != 0) {
1558 					nd6log((LOG_ERR,
1559 					    "nd6_prefix_offlink: failed to "
1560 					    "recover a prefix %s/%d from %s "
1561 					    "to %s (errno = %d)\n",
1562 					    ip6_sprintf(&opr->ndpr_prefix.sin6_addr),
1563 					    opr->ndpr_plen, if_name(ifp),
1564 					    if_name(opr->ndpr_ifp), e));
1565 				}
1566 			}
1567 		}
1568 	}
1569 	else {
1570 		/* XXX: can we still set the NDPRF_ONLINK flag? */
1571 		nd6log((LOG_ERR,
1572 		    "nd6_prefix_offlink: failed to delete route: "
1573 		    "%s/%d on %s (errno = %d)\n",
1574 		    ip6_sprintf(&sa6.sin6_addr), pr->ndpr_plen, if_name(ifp),
1575 		    error));
1576 	}
1577 
1578 	if (rt != NULL) {
1579 		if (rt->rt_refcnt <= 0) {
1580 			/* XXX: we should free the entry ourselves. */
1581 			rt->rt_refcnt++;
1582 			rtfree(rt);
1583 		}
1584 	}
1585 
1586 	return (error);
1587 }
1588 
1589 /*
1590  * Parameters:
1591  *	ifid:	Mobile IPv6 addition
1592  */
1593 static struct in6_ifaddr *
1594 in6_ifadd(struct nd_prefix *pr, struct in6_addr *ifid)
1595 {
1596 	struct ifnet *ifp = pr->ndpr_ifp;
1597 	struct ifaddr *ifa;
1598 	struct in6_aliasreq ifra;
1599 	struct in6_ifaddr *ia, *ib;
1600 	int error, plen0;
1601 	struct in6_addr mask;
1602 	int prefixlen = pr->ndpr_plen;
1603 
1604 	in6_len2mask(&mask, prefixlen);
1605 
1606 	/*
1607 	 * find a link-local address (will be interface ID).
1608 	 * Is it really mandatory? Theoretically, a global or a site-local
1609 	 * address can be configured without a link-local address, if we
1610 	 * have a unique interface identifier...
1611 	 *
1612 	 * it is not mandatory to have a link-local address, we can generate
1613 	 * interface identifier on the fly.  we do this because:
1614 	 * (1) it should be the easiest way to find interface identifier.
1615 	 * (2) RFC2462 5.4 suggesting the use of the same interface identifier
1616 	 * for multiple addresses on a single interface, and possible shortcut
1617 	 * of DAD.  we omitted DAD for this reason in the past.
1618 	 * (3) a user can prevent autoconfiguration of global address
1619 	 * by removing link-local address by hand (this is partly because we
1620 	 * don't have other way to control the use of IPv6 on a interface.
1621 	 * this has been our design choice - cf. NRL's "ifconfig auto").
1622 	 * (4) it is easier to manage when an interface has addresses
1623 	 * with the same interface identifier, than to have multiple addresses
1624 	 * with different interface identifiers.
1625 	 *
1626 	 * Mobile IPv6 addition: allow for caller to specify a wished interface
1627 	 * ID. This is to not break connections when moving addresses between
1628 	 * interfaces.
1629 	 */
1630 	ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp, 0);/* 0 is OK? */
1631 	if (ifa)
1632 		ib = (struct in6_ifaddr *)ifa;
1633 	else
1634 		return NULL;
1635 
1636 #if 0 /* don't care link local addr state, and always do DAD */
1637 	/* if link-local address is not eligible, do not autoconfigure. */
1638 	if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_NOTREADY) {
1639 		kprintf("in6_ifadd: link-local address not ready\n");
1640 		return NULL;
1641 	}
1642 #endif
1643 
1644 	/* prefixlen + ifidlen must be equal to 128 */
1645 	plen0 = in6_mask2len(&ib->ia_prefixmask.sin6_addr, NULL);
1646 	if (prefixlen != plen0) {
1647 		nd6log((LOG_INFO, "in6_ifadd: wrong prefixlen for %s "
1648 		    "(prefix=%d ifid=%d)\n",
1649 		    if_name(ifp), prefixlen, 128 - plen0));
1650 		return NULL;
1651 	}
1652 
1653 	/* make ifaddr */
1654 
1655 	bzero(&ifra, sizeof(ifra));
1656 	/*
1657 	 * in6_update_ifa() does not use ifra_name, but we accurately set it
1658 	 * for safety.
1659 	 */
1660 	strncpy(ifra.ifra_name, if_name(ifp), sizeof(ifra.ifra_name));
1661 	ifra.ifra_addr.sin6_family = AF_INET6;
1662 	ifra.ifra_addr.sin6_len = sizeof(struct sockaddr_in6);
1663 	/* prefix */
1664 	bcopy(&pr->ndpr_prefix.sin6_addr, &ifra.ifra_addr.sin6_addr,
1665 	      sizeof(ifra.ifra_addr.sin6_addr));
1666 	ifra.ifra_addr.sin6_addr.s6_addr32[0] &= mask.s6_addr32[0];
1667 	ifra.ifra_addr.sin6_addr.s6_addr32[1] &= mask.s6_addr32[1];
1668 	ifra.ifra_addr.sin6_addr.s6_addr32[2] &= mask.s6_addr32[2];
1669 	ifra.ifra_addr.sin6_addr.s6_addr32[3] &= mask.s6_addr32[3];
1670 
1671 	/* interface ID */
1672 	if (ifid == NULL || IN6_IS_ADDR_UNSPECIFIED(ifid))
1673 		ifid = &ib->ia_addr.sin6_addr;
1674 	ifra.ifra_addr.sin6_addr.s6_addr32[0]
1675 		|= (ifid->s6_addr32[0] & ~mask.s6_addr32[0]);
1676 	ifra.ifra_addr.sin6_addr.s6_addr32[1]
1677 		|= (ifid->s6_addr32[1] & ~mask.s6_addr32[1]);
1678 	ifra.ifra_addr.sin6_addr.s6_addr32[2]
1679 		|= (ifid->s6_addr32[2] & ~mask.s6_addr32[2]);
1680 	ifra.ifra_addr.sin6_addr.s6_addr32[3]
1681 		|= (ifid->s6_addr32[3] & ~mask.s6_addr32[3]);
1682 
1683 	/* new prefix mask. */
1684 	ifra.ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6);
1685 	ifra.ifra_prefixmask.sin6_family = AF_INET6;
1686 	bcopy(&mask, &ifra.ifra_prefixmask.sin6_addr,
1687 	      sizeof(ifra.ifra_prefixmask.sin6_addr));
1688 
1689 	/*
1690 	 * lifetime.
1691 	 * XXX: in6_init_address_ltimes would override these values later.
1692 	 * We should reconsider this logic.
1693 	 */
1694 	ifra.ifra_lifetime.ia6t_vltime = pr->ndpr_vltime;
1695 	ifra.ifra_lifetime.ia6t_pltime = pr->ndpr_pltime;
1696 
1697 	/* XXX: scope zone ID? */
1698 
1699 	ifra.ifra_flags |= IN6_IFF_AUTOCONF; /* obey autoconf */
1700 	/*
1701 	 * temporarily set the nopfx flag to avoid conflict.
1702 	 * XXX: we should reconsider the entire mechanism about prefix
1703 	 * manipulation.
1704 	 */
1705 	ifra.ifra_flags |= IN6_IFF_NOPFX;
1706 
1707 	/*
1708 	 * keep the new address, regardless of the result of in6_update_ifa.
1709 	 * XXX: this address is now meaningless.
1710 	 * We should reconsider its role.
1711 	 */
1712 	pr->ndpr_addr = ifra.ifra_addr.sin6_addr;
1713 
1714 	/* allocate ifaddr structure, link into chain, etc. */
1715 	if ((error = in6_update_ifa(ifp, &ifra, NULL)) != 0) {
1716 		nd6log((LOG_ERR,
1717 		    "in6_ifadd: failed to make ifaddr %s on %s (errno=%d)\n",
1718 		    ip6_sprintf(&ifra.ifra_addr.sin6_addr), if_name(ifp),
1719 		    error));
1720 		return (NULL);	/* ifaddr must not have been allocated. */
1721 	}
1722 
1723 	ia = in6ifa_ifpwithaddr(ifp, &ifra.ifra_addr.sin6_addr);
1724 
1725 	return (ia);		/* this must NOT be NULL. */
1726 }
1727 
1728 /*
1729  * Parameters:
1730  *	ia0:	corresponding public address
1731  */
1732 int
1733 in6_tmpifadd(const struct in6_ifaddr *ia0, int forcegen)
1734 {
1735 	struct ifnet *ifp = ia0->ia_ifa.ifa_ifp;
1736 	struct in6_ifaddr *newia;
1737 	struct in6_aliasreq ifra;
1738 	int i, error;
1739 	int trylimit = 3;	/* XXX: adhoc value */
1740 	u_int32_t randid[2];
1741 	time_t vltime0, pltime0;
1742 
1743 	bzero(&ifra, sizeof(ifra));
1744 	strncpy(ifra.ifra_name, if_name(ifp), sizeof(ifra.ifra_name));
1745 	ifra.ifra_addr = ia0->ia_addr;
1746 	/* copy prefix mask */
1747 	ifra.ifra_prefixmask = ia0->ia_prefixmask;
1748 	/* clear the old IFID */
1749 	for (i = 0; i < 4; i++) {
1750 		ifra.ifra_addr.sin6_addr.s6_addr32[i]
1751 			&= ifra.ifra_prefixmask.sin6_addr.s6_addr32[i];
1752 	}
1753 
1754 again:
1755 	in6_get_tmpifid(ifp, (u_int8_t *)randid,
1756 			(const u_int8_t *)&ia0->ia_addr.sin6_addr.s6_addr[8],
1757 			forcegen);
1758 	ifra.ifra_addr.sin6_addr.s6_addr32[2]
1759 		|= (randid[0] & ~(ifra.ifra_prefixmask.sin6_addr.s6_addr32[2]));
1760 	ifra.ifra_addr.sin6_addr.s6_addr32[3]
1761 		|= (randid[1] & ~(ifra.ifra_prefixmask.sin6_addr.s6_addr32[3]));
1762 
1763 	/*
1764 	 * If by chance the new temporary address is the same as an address
1765 	 * already assigned to the interface, generate a new randomized
1766 	 * interface identifier and repeat this step.
1767 	 * RFC 3041 3.3 (4).
1768 	 */
1769 	if (in6ifa_ifpwithaddr(ifp, &ifra.ifra_addr.sin6_addr) != NULL) {
1770 		if (trylimit-- == 0) {
1771 			nd6log((LOG_NOTICE, "in6_tmpifadd: failed to find "
1772 			    "a unique random IFID\n"));
1773 			return (EEXIST);
1774 		}
1775 		forcegen = 1;
1776 		goto again;
1777 	}
1778 
1779 	/*
1780 	 * The Valid Lifetime is the lower of the Valid Lifetime of the
1781          * public address or TEMP_VALID_LIFETIME.
1782 	 * The Preferred Lifetime is the lower of the Preferred Lifetime
1783          * of the public address or TEMP_PREFERRED_LIFETIME -
1784          * DESYNC_FACTOR.
1785 	 */
1786 	if (ia0->ia6_lifetime.ia6t_expire != 0) {
1787 		vltime0 = IFA6_IS_INVALID(ia0) ? 0 :
1788 			(ia0->ia6_lifetime.ia6t_expire - time_second);
1789 		if (vltime0 > ip6_temp_valid_lifetime)
1790 			vltime0 = ip6_temp_valid_lifetime;
1791 	} else
1792 		vltime0 = ip6_temp_valid_lifetime;
1793 	if (ia0->ia6_lifetime.ia6t_preferred != 0) {
1794 		pltime0 = IFA6_IS_DEPRECATED(ia0) ? 0 :
1795 			(ia0->ia6_lifetime.ia6t_preferred - time_second);
1796 		if (pltime0 > ip6_temp_preferred_lifetime - ip6_desync_factor) {
1797 			pltime0 = ip6_temp_preferred_lifetime -
1798 				ip6_desync_factor;
1799 		}
1800 	} else
1801 		pltime0 = ip6_temp_preferred_lifetime - ip6_desync_factor;
1802 	ifra.ifra_lifetime.ia6t_vltime = vltime0;
1803 	ifra.ifra_lifetime.ia6t_pltime = pltime0;
1804 
1805 	/*
1806 	 * A temporary address is created only if this calculated Preferred
1807 	 * Lifetime is greater than REGEN_ADVANCE time units.
1808 	 */
1809 	if (ifra.ifra_lifetime.ia6t_pltime <= ip6_temp_regen_advance)
1810 		return (0);
1811 
1812 	/* XXX: scope zone ID? */
1813 
1814 	ifra.ifra_flags |= (IN6_IFF_AUTOCONF|IN6_IFF_TEMPORARY);
1815 
1816 	/* allocate ifaddr structure, link into chain, etc. */
1817 	if ((error = in6_update_ifa(ifp, &ifra, NULL)) != 0)
1818 		return (error);
1819 
1820 	newia = in6ifa_ifpwithaddr(ifp, &ifra.ifra_addr.sin6_addr);
1821 	if (newia == NULL) {	/* XXX: can it happen? */
1822 		nd6log((LOG_ERR,
1823 		    "in6_tmpifadd: ifa update succeeded, but we got "
1824 		    "no ifaddr\n"));
1825 		return (EINVAL); /* XXX */
1826 	}
1827 	newia->ia6_ndpr = ia0->ia6_ndpr;
1828 	newia->ia6_ndpr->ndpr_refcnt++;
1829 
1830 	return (0);
1831 }
1832 
1833 int
1834 in6_init_prefix_ltimes(struct nd_prefix *ndpr)
1835 {
1836 	/* check if preferred lifetime > valid lifetime.  RFC2462 5.5.3 (c) */
1837 	if (ndpr->ndpr_pltime > ndpr->ndpr_vltime) {
1838 		nd6log((LOG_INFO, "in6_init_prefix_ltimes: preferred lifetime"
1839 		    "(%d) is greater than valid lifetime(%d)\n",
1840 		    (u_int)ndpr->ndpr_pltime, (u_int)ndpr->ndpr_vltime));
1841 		return (EINVAL);
1842 	}
1843 	if (ndpr->ndpr_pltime == ND6_INFINITE_LIFETIME)
1844 		ndpr->ndpr_preferred = 0;
1845 	else
1846 		ndpr->ndpr_preferred = time_second + ndpr->ndpr_pltime;
1847 	if (ndpr->ndpr_vltime == ND6_INFINITE_LIFETIME)
1848 		ndpr->ndpr_expire = 0;
1849 	else
1850 		ndpr->ndpr_expire = time_second + ndpr->ndpr_vltime;
1851 
1852 	return 0;
1853 }
1854 
1855 static void
1856 in6_init_address_ltimes(struct nd_prefix *new, struct in6_addrlifetime *lt6)
1857 {
1858 	/* init ia6t_expire */
1859 	if (lt6->ia6t_vltime == ND6_INFINITE_LIFETIME)
1860 		lt6->ia6t_expire = 0;
1861 	else {
1862 		lt6->ia6t_expire = time_second;
1863 		lt6->ia6t_expire += lt6->ia6t_vltime;
1864 	}
1865 
1866 	/* init ia6t_preferred */
1867 	if (lt6->ia6t_pltime == ND6_INFINITE_LIFETIME)
1868 		lt6->ia6t_preferred = 0;
1869 	else {
1870 		lt6->ia6t_preferred = time_second;
1871 		lt6->ia6t_preferred += lt6->ia6t_pltime;
1872 	}
1873 }
1874 
1875 /*
1876  * Delete all the routing table entries that use the specified gateway.
1877  * XXX: this function causes search through all entries of routing table, so
1878  * it shouldn't be called when acting as a router.
1879  */
1880 void
1881 rt6_flush(struct in6_addr *gateway, struct ifnet *ifp)
1882 {
1883 	struct radix_node_head *rnh = rt_tables[mycpuid][AF_INET6];
1884 
1885 	crit_enter();
1886 
1887 	/* We'll care only link-local addresses */
1888 	if (!IN6_IS_ADDR_LINKLOCAL(gateway)) {
1889 		crit_exit();
1890 		return;
1891 	}
1892 	/* XXX: hack for KAME's link-local address kludge */
1893 	gateway->s6_addr16[1] = htons(ifp->if_index);
1894 
1895 	rnh->rnh_walktree(rnh, rt6_deleteroute, (void *)gateway);
1896 	crit_exit();
1897 }
1898 
1899 static int
1900 rt6_deleteroute(struct radix_node *rn, void *arg)
1901 {
1902 #define SIN6(s)	((struct sockaddr_in6 *)s)
1903 	struct rtentry *rt = (struct rtentry *)rn;
1904 	struct in6_addr *gate = (struct in6_addr *)arg;
1905 
1906 	if (rt->rt_gateway == NULL || rt->rt_gateway->sa_family != AF_INET6)
1907 		return (0);
1908 
1909 	if (!IN6_ARE_ADDR_EQUAL(gate, &SIN6(rt->rt_gateway)->sin6_addr))
1910 		return (0);
1911 
1912 	/*
1913 	 * Do not delete a static route.
1914 	 * XXX: this seems to be a bit ad-hoc. Should we consider the
1915 	 * 'cloned' bit instead?
1916 	 */
1917 	if (rt->rt_flags & RTF_STATIC)
1918 		return (0);
1919 
1920 	/*
1921 	 * We delete only host route. This means, in particular, we don't
1922 	 * delete default route.
1923 	 */
1924 	if (!(rt->rt_flags & RTF_HOST))
1925 		return (0);
1926 
1927 	return (rtrequest(RTM_DELETE, rt_key(rt),
1928 			 rt->rt_gateway, rt_mask(rt), rt->rt_flags, 0));
1929 #undef SIN6
1930 }
1931 
1932 int
1933 nd6_setdefaultiface(int ifindex)
1934 {
1935 	int error = 0;
1936 
1937 	if (ifindex < 0 || if_index < ifindex)
1938 		return (EINVAL);
1939 
1940 	if (nd6_defifindex != ifindex) {
1941 		nd6_defifindex = ifindex;
1942 		if (nd6_defifindex > 0)
1943 			nd6_defifp = ifindex2ifnet[nd6_defifindex];
1944 		else
1945 			nd6_defifp = NULL;
1946 
1947 		/*
1948 		 * If the Default Router List is empty, install a route
1949 		 * to the specified interface as default or remove the default
1950 		 * route when the default interface becomes canceled.
1951 		 * The check for the queue is actually redundant, but
1952 		 * we do this here to avoid re-install the default route
1953 		 * if the list is NOT empty.
1954 		 */
1955 		if (TAILQ_FIRST(&nd_defrouter) == NULL)
1956 			defrouter_select();
1957 
1958 		/*
1959 		 * Our current implementation assumes one-to-one maping between
1960 		 * interfaces and links, so it would be natural to use the
1961 		 * default interface as the default link.
1962 		 */
1963 		scope6_setdefault(nd6_defifp);
1964 	}
1965 
1966 	return (error);
1967 }
1968