xref: /freebsd/sys/netinet6/nd6_rtr.c (revision 729362425c09cf6b362366aabc6fb547eee8035a)
1 /*	$FreeBSD$	*/
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 
48 #include <net/if.h>
49 #include <net/if_types.h>
50 #include <net/if_dl.h>
51 #include <net/route.h>
52 #include <net/radix.h>
53 
54 #include <netinet/in.h>
55 #include <netinet6/in6_var.h>
56 #include <netinet6/in6_ifattach.h>
57 #include <netinet/ip6.h>
58 #include <netinet6/ip6_var.h>
59 #include <netinet6/nd6.h>
60 #include <netinet/icmp6.h>
61 #include <netinet6/scope6_var.h>
62 
63 #include <net/net_osdep.h>
64 
65 #define SDL(s)	((struct sockaddr_dl *)s)
66 
67 static struct nd_defrouter *defrtrlist_update __P((struct nd_defrouter *));
68 static struct in6_ifaddr *in6_ifadd __P((struct nd_prefix *,
69 	struct in6_addr *));
70 static struct nd_pfxrouter *pfxrtr_lookup __P((struct nd_prefix *,
71 	struct nd_defrouter *));
72 static void pfxrtr_add __P((struct nd_prefix *, struct nd_defrouter *));
73 static void pfxrtr_del __P((struct nd_pfxrouter *));
74 static struct nd_pfxrouter *find_pfxlist_reachable_router
75 	__P((struct nd_prefix *));
76 static void defrouter_addifreq __P((struct ifnet *));
77 static void nd6_rtmsg __P((int, struct rtentry *));
78 
79 static void in6_init_address_ltimes __P((struct nd_prefix *ndpr,
80 					 struct in6_addrlifetime *lt6));
81 
82 static int rt6_deleteroute __P((struct radix_node *, void *));
83 
84 extern int nd6_recalc_reachtm_interval;
85 
86 static struct ifnet *nd6_defifp;
87 int nd6_defifindex;
88 
89 int ip6_use_tempaddr = 0;
90 
91 int ip6_desync_factor;
92 u_int32_t ip6_temp_preferred_lifetime = DEF_TEMP_PREFERRED_LIFETIME;
93 u_int32_t ip6_temp_valid_lifetime = DEF_TEMP_VALID_LIFETIME;
94 /*
95  * shorter lifetimes for debugging purposes.
96 int ip6_temp_preferred_lifetime = 800;
97 static int ip6_temp_valid_lifetime = 1800;
98 */
99 int ip6_temp_regen_advance = TEMPADDR_REGEN_ADVANCE;
100 
101 /*
102  * Receive Router Solicitation Message - just for routers.
103  * Router solicitation/advertisement is mostly managed by userland program
104  * (rtadvd) so here we have no function like nd6_ra_output().
105  *
106  * Based on RFC 2461
107  */
108 void
109 nd6_rs_input(m, off, icmp6len)
110 	struct	mbuf *m;
111 	int off, icmp6len;
112 {
113 	struct ifnet *ifp = m->m_pkthdr.rcvif;
114 	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
115 	struct nd_router_solicit *nd_rs;
116 	struct in6_addr saddr6 = ip6->ip6_src;
117 #if 0
118 	struct in6_addr daddr6 = ip6->ip6_dst;
119 #endif
120 	char *lladdr = NULL;
121 	int lladdrlen = 0;
122 #if 0
123 	struct sockaddr_dl *sdl = (struct sockaddr_dl *)NULL;
124 	struct llinfo_nd6 *ln = (struct llinfo_nd6 *)NULL;
125 	struct rtentry *rt = NULL;
126 	int is_newentry;
127 #endif
128 	union nd_opts ndopts;
129 
130 	/* If I'm not a router, ignore it. */
131 	if (ip6_accept_rtadv != 0 || ip6_forwarding != 1)
132 		goto freeit;
133 
134 	/* Sanity checks */
135 	if (ip6->ip6_hlim != 255) {
136 		nd6log((LOG_ERR,
137 		    "nd6_rs_input: invalid hlim (%d) from %s to %s on %s\n",
138 		    ip6->ip6_hlim, ip6_sprintf(&ip6->ip6_src),
139 		    ip6_sprintf(&ip6->ip6_dst), if_name(ifp)));
140 		goto bad;
141 	}
142 
143 	/*
144 	 * Don't update the neighbor cache, if src = ::.
145 	 * This indicates that the src has no IP address assigned yet.
146 	 */
147 	if (IN6_IS_ADDR_UNSPECIFIED(&saddr6))
148 		goto freeit;
149 
150 #ifndef PULLDOWN_TEST
151 	IP6_EXTHDR_CHECK(m, off, icmp6len,);
152 	nd_rs = (struct nd_router_solicit *)((caddr_t)ip6 + off);
153 #else
154 	IP6_EXTHDR_GET(nd_rs, struct nd_router_solicit *, m, off, icmp6len);
155 	if (nd_rs == NULL) {
156 		icmp6stat.icp6s_tooshort++;
157 		return;
158 	}
159 #endif
160 
161 	icmp6len -= sizeof(*nd_rs);
162 	nd6_option_init(nd_rs + 1, icmp6len, &ndopts);
163 	if (nd6_options(&ndopts) < 0) {
164 		nd6log((LOG_INFO,
165 		    "nd6_rs_input: invalid ND option, ignored\n"));
166 		/* nd6_options have incremented stats */
167 		goto freeit;
168 	}
169 
170 	if (ndopts.nd_opts_src_lladdr) {
171 		lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1);
172 		lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3;
173 	}
174 
175 	if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
176 		nd6log((LOG_INFO,
177 		    "nd6_rs_input: lladdrlen mismatch for %s "
178 		    "(if %d, RS packet %d)\n",
179 			ip6_sprintf(&saddr6), ifp->if_addrlen, lladdrlen - 2));
180 		goto bad;
181 	}
182 
183 	nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, ND_ROUTER_SOLICIT, 0);
184 
185  freeit:
186 	m_freem(m);
187 	return;
188 
189  bad:
190 	icmp6stat.icp6s_badrs++;
191 	m_freem(m);
192 }
193 
194 /*
195  * Receive Router Advertisement Message.
196  *
197  * Based on RFC 2461
198  * TODO: on-link bit on prefix information
199  * TODO: ND_RA_FLAG_{OTHER,MANAGED} processing
200  */
201 void
202 nd6_ra_input(m, off, icmp6len)
203 	struct	mbuf *m;
204 	int off, icmp6len;
205 {
206 	struct ifnet *ifp = m->m_pkthdr.rcvif;
207 	struct nd_ifinfo *ndi = &nd_ifinfo[ifp->if_index];
208 	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
209 	struct nd_router_advert *nd_ra;
210 	struct in6_addr saddr6 = ip6->ip6_src;
211 #if 0
212 	struct in6_addr daddr6 = ip6->ip6_dst;
213 	int flags; /* = nd_ra->nd_ra_flags_reserved; */
214 	int is_managed = ((flags & ND_RA_FLAG_MANAGED) != 0);
215 	int is_other = ((flags & ND_RA_FLAG_OTHER) != 0);
216 #endif
217 	union nd_opts ndopts;
218 	struct nd_defrouter *dr;
219 
220 	if (ip6_accept_rtadv == 0)
221 		goto freeit;
222 
223 	if (ip6->ip6_hlim != 255) {
224 		nd6log((LOG_ERR,
225 		    "nd6_ra_input: invalid hlim (%d) from %s to %s on %s\n",
226 		    ip6->ip6_hlim, ip6_sprintf(&ip6->ip6_src),
227 		    ip6_sprintf(&ip6->ip6_dst), if_name(ifp)));
228 		goto bad;
229 	}
230 
231 	if (!IN6_IS_ADDR_LINKLOCAL(&saddr6)) {
232 		nd6log((LOG_ERR,
233 		    "nd6_ra_input: src %s is not link-local\n",
234 		    ip6_sprintf(&saddr6)));
235 		goto bad;
236 	}
237 
238 #ifndef PULLDOWN_TEST
239 	IP6_EXTHDR_CHECK(m, off, icmp6len,);
240 	nd_ra = (struct nd_router_advert *)((caddr_t)ip6 + off);
241 #else
242 	IP6_EXTHDR_GET(nd_ra, struct nd_router_advert *, m, off, icmp6len);
243 	if (nd_ra == NULL) {
244 		icmp6stat.icp6s_tooshort++;
245 		return;
246 	}
247 #endif
248 
249 	icmp6len -= sizeof(*nd_ra);
250 	nd6_option_init(nd_ra + 1, icmp6len, &ndopts);
251 	if (nd6_options(&ndopts) < 0) {
252 		nd6log((LOG_INFO,
253 		    "nd6_ra_input: invalid ND option, ignored\n"));
254 		/* nd6_options have incremented stats */
255 		goto freeit;
256 	}
257 
258     {
259 	struct nd_defrouter dr0;
260 	u_int32_t advreachable = nd_ra->nd_ra_reachable;
261 
262 	dr0.rtaddr = saddr6;
263 	dr0.flags  = nd_ra->nd_ra_flags_reserved;
264 	dr0.rtlifetime = ntohs(nd_ra->nd_ra_router_lifetime);
265 	dr0.expire = time_second + dr0.rtlifetime;
266 	dr0.ifp = ifp;
267 	dr0.advint = 0;		/* Mobile IPv6 */
268 	dr0.advint_expire = 0;	/* Mobile IPv6 */
269 	dr0.advints_lost = 0;	/* Mobile IPv6 */
270 	/* unspecified or not? (RFC 2461 6.3.4) */
271 	if (advreachable) {
272 		advreachable = ntohl(advreachable);
273 		if (advreachable <= MAX_REACHABLE_TIME &&
274 		    ndi->basereachable != advreachable) {
275 			ndi->basereachable = advreachable;
276 			ndi->reachable = ND_COMPUTE_RTIME(ndi->basereachable);
277 			ndi->recalctm = nd6_recalc_reachtm_interval; /* reset */
278 		}
279 	}
280 	if (nd_ra->nd_ra_retransmit)
281 		ndi->retrans = ntohl(nd_ra->nd_ra_retransmit);
282 	if (nd_ra->nd_ra_curhoplimit)
283 		ndi->chlim = nd_ra->nd_ra_curhoplimit;
284 	dr = defrtrlist_update(&dr0);
285     }
286 
287 	/*
288 	 * prefix
289 	 */
290 	if (ndopts.nd_opts_pi) {
291 		struct nd_opt_hdr *pt;
292 		struct nd_opt_prefix_info *pi = NULL;
293 		struct nd_prefix pr;
294 
295 		for (pt = (struct nd_opt_hdr *)ndopts.nd_opts_pi;
296 		     pt <= (struct nd_opt_hdr *)ndopts.nd_opts_pi_end;
297 		     pt = (struct nd_opt_hdr *)((caddr_t)pt +
298 						(pt->nd_opt_len << 3))) {
299 			if (pt->nd_opt_type != ND_OPT_PREFIX_INFORMATION)
300 				continue;
301 			pi = (struct nd_opt_prefix_info *)pt;
302 
303 			if (pi->nd_opt_pi_len != 4) {
304 				nd6log((LOG_INFO,
305 				    "nd6_ra_input: invalid option "
306 				    "len %d for prefix information option, "
307 				    "ignored\n", pi->nd_opt_pi_len));
308 				continue;
309 			}
310 
311 			if (128 < pi->nd_opt_pi_prefix_len) {
312 				nd6log((LOG_INFO,
313 				    "nd6_ra_input: invalid prefix "
314 				    "len %d for prefix information option, "
315 				    "ignored\n", pi->nd_opt_pi_prefix_len));
316 				continue;
317 			}
318 
319 			if (IN6_IS_ADDR_MULTICAST(&pi->nd_opt_pi_prefix)
320 			 || IN6_IS_ADDR_LINKLOCAL(&pi->nd_opt_pi_prefix)) {
321 				nd6log((LOG_INFO,
322 				    "nd6_ra_input: invalid prefix "
323 				    "%s, ignored\n",
324 				    ip6_sprintf(&pi->nd_opt_pi_prefix)));
325 				continue;
326 			}
327 
328 			/* aggregatable unicast address, rfc2374 */
329 			if ((pi->nd_opt_pi_prefix.s6_addr8[0] & 0xe0) == 0x20
330 			 && pi->nd_opt_pi_prefix_len != 64) {
331 				nd6log((LOG_INFO,
332 				    "nd6_ra_input: invalid prefixlen "
333 				    "%d for rfc2374 prefix %s, ignored\n",
334 				    pi->nd_opt_pi_prefix_len,
335 				    ip6_sprintf(&pi->nd_opt_pi_prefix)));
336 				continue;
337 			}
338 
339 			bzero(&pr, sizeof(pr));
340 			pr.ndpr_prefix.sin6_family = AF_INET6;
341 			pr.ndpr_prefix.sin6_len = sizeof(pr.ndpr_prefix);
342 			pr.ndpr_prefix.sin6_addr = pi->nd_opt_pi_prefix;
343 			pr.ndpr_ifp = (struct ifnet *)m->m_pkthdr.rcvif;
344 
345 			pr.ndpr_raf_onlink = (pi->nd_opt_pi_flags_reserved &
346 					      ND_OPT_PI_FLAG_ONLINK) ? 1 : 0;
347 			pr.ndpr_raf_auto = (pi->nd_opt_pi_flags_reserved &
348 					    ND_OPT_PI_FLAG_AUTO) ? 1 : 0;
349 			pr.ndpr_plen = pi->nd_opt_pi_prefix_len;
350 			pr.ndpr_vltime = ntohl(pi->nd_opt_pi_valid_time);
351 			pr.ndpr_pltime =
352 				ntohl(pi->nd_opt_pi_preferred_time);
353 
354 			if (in6_init_prefix_ltimes(&pr))
355 				continue; /* prefix lifetime init failed */
356 
357 			(void)prelist_update(&pr, dr, m);
358 		}
359 	}
360 
361 	/*
362 	 * MTU
363 	 */
364 	if (ndopts.nd_opts_mtu && ndopts.nd_opts_mtu->nd_opt_mtu_len == 1) {
365 		u_int32_t mtu = ntohl(ndopts.nd_opts_mtu->nd_opt_mtu_mtu);
366 
367 		/* lower bound */
368 		if (mtu < IPV6_MMTU) {
369 			nd6log((LOG_INFO, "nd6_ra_input: bogus mtu option "
370 			    "mtu=%d sent from %s, ignoring\n",
371 			    mtu, ip6_sprintf(&ip6->ip6_src)));
372 			goto skip;
373 		}
374 
375 		/* upper bound */
376 		if (ndi->maxmtu) {
377 			if (mtu <= ndi->maxmtu) {
378 				int change = (ndi->linkmtu != mtu);
379 
380 				ndi->linkmtu = mtu;
381 				if (change) /* in6_maxmtu may change */
382 					in6_setmaxmtu();
383 			} else {
384 				nd6log((LOG_INFO, "nd6_ra_input: bogus mtu "
385 				    "mtu=%d sent from %s; "
386 				    "exceeds maxmtu %d, ignoring\n",
387 				    mtu, ip6_sprintf(&ip6->ip6_src),
388 				    ndi->maxmtu));
389 			}
390 		} else {
391 			nd6log((LOG_INFO, "nd6_ra_input: mtu option "
392 			    "mtu=%d sent from %s; maxmtu unknown, "
393 			    "ignoring\n",
394 			    mtu, ip6_sprintf(&ip6->ip6_src)));
395 		}
396 	}
397 
398  skip:
399 
400 	/*
401 	 * Source link layer address
402 	 */
403     {
404 	char *lladdr = NULL;
405 	int lladdrlen = 0;
406 
407 	if (ndopts.nd_opts_src_lladdr) {
408 		lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1);
409 		lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3;
410 	}
411 
412 	if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
413 		nd6log((LOG_INFO,
414 		    "nd6_ra_input: lladdrlen mismatch for %s "
415 		    "(if %d, RA packet %d)\n",
416 			ip6_sprintf(&saddr6), ifp->if_addrlen, lladdrlen - 2));
417 		goto bad;
418 	}
419 
420 	nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, ND_ROUTER_ADVERT, 0);
421 
422 	/*
423 	 * Installing a link-layer address might change the state of the
424 	 * router's neighbor cache, which might also affect our on-link
425 	 * detection of adveritsed prefixes.
426 	 */
427 	pfxlist_onlink_check();
428     }
429 
430  freeit:
431 	m_freem(m);
432 	return;
433 
434  bad:
435 	icmp6stat.icp6s_badra++;
436 	m_freem(m);
437 }
438 
439 /*
440  * default router list proccessing sub routines
441  */
442 
443 /* tell the change to user processes watching the routing socket. */
444 static void
445 nd6_rtmsg(cmd, rt)
446 	int cmd;
447 	struct rtentry *rt;
448 {
449 	struct rt_addrinfo info;
450 
451 	bzero((caddr_t)&info, sizeof(info));
452 	info.rti_info[RTAX_DST] = rt_key(rt);
453 	info.rti_info[RTAX_GATEWAY] = rt->rt_gateway;
454 	info.rti_info[RTAX_NETMASK] = rt_mask(rt);
455 	info.rti_info[RTAX_IFP] =
456 		(struct sockaddr *)TAILQ_FIRST(&rt->rt_ifp->if_addrlist);
457 	info.rti_info[RTAX_IFA] = rt->rt_ifa->ifa_addr;
458 
459 	rt_missmsg(cmd, &info, rt->rt_flags, 0);
460 }
461 
462 void
463 defrouter_addreq(new)
464 	struct nd_defrouter *new;
465 {
466 	struct sockaddr_in6 def, mask, gate;
467 	struct rtentry *newrt = NULL;
468 	int s;
469 
470 	Bzero(&def, sizeof(def));
471 	Bzero(&mask, sizeof(mask));
472 	Bzero(&gate, sizeof(gate));
473 
474 	def.sin6_len = mask.sin6_len = gate.sin6_len
475 		= sizeof(struct sockaddr_in6);
476 	def.sin6_family = mask.sin6_family = gate.sin6_family = AF_INET6;
477 	gate.sin6_addr = new->rtaddr;
478 
479 	s = splnet();
480 	(void)rtrequest(RTM_ADD, (struct sockaddr *)&def,
481 		(struct sockaddr *)&gate, (struct sockaddr *)&mask,
482 		RTF_GATEWAY, &newrt);
483 	if (newrt) {
484 		nd6_rtmsg(RTM_ADD, newrt); /* tell user process */
485 		newrt->rt_refcnt--;
486 	}
487 	splx(s);
488 	return;
489 }
490 
491 /* Add a route to a given interface as default */
492 void
493 defrouter_addifreq(ifp)
494 	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(addr, ifp)
540 	struct in6_addr *addr;
541 	struct ifnet *ifp;
542 {
543 	struct nd_defrouter *dr;
544 
545 	for (dr = TAILQ_FIRST(&nd_defrouter); dr;
546 	     dr = TAILQ_NEXT(dr, dr_entry)) {
547 		if (dr->ifp == ifp && IN6_ARE_ADDR_EQUAL(addr, &dr->rtaddr))
548 			return(dr);
549 	}
550 
551 	return(NULL);		/* search failed */
552 }
553 
554 void
555 defrouter_delreq(dr, dofree)
556 	struct nd_defrouter *dr;
557 	int dofree;
558 {
559 	struct sockaddr_in6 def, mask, gate;
560 	struct rtentry *oldrt = NULL;
561 
562 	Bzero(&def, sizeof(def));
563 	Bzero(&mask, sizeof(mask));
564 	Bzero(&gate, sizeof(gate));
565 
566 	def.sin6_len = mask.sin6_len = gate.sin6_len
567 		= sizeof(struct sockaddr_in6);
568 	def.sin6_family = mask.sin6_family = gate.sin6_family = AF_INET6;
569 	gate.sin6_addr = dr->rtaddr;
570 
571 	rtrequest(RTM_DELETE, (struct sockaddr *)&def,
572 		  (struct sockaddr *)&gate,
573 		  (struct sockaddr *)&mask,
574 		  RTF_GATEWAY, &oldrt);
575 	if (oldrt) {
576 		nd6_rtmsg(RTM_DELETE, oldrt);
577 		RTFREE(oldrt);
578 	}
579 
580 	if (dofree)		/* XXX: necessary? */
581 		free(dr, M_IP6NDP);
582 }
583 
584 void
585 defrtrlist_del(dr)
586 	struct nd_defrouter *dr;
587 {
588 	struct nd_defrouter *deldr = NULL;
589 	struct nd_prefix *pr;
590 
591 	/*
592 	 * Flush all the routing table entries that use the router
593 	 * as a next hop.
594 	 */
595 	if (!ip6_forwarding && ip6_accept_rtadv) {
596 		/* above is a good condition? */
597 		rt6_flush(&dr->rtaddr, dr->ifp);
598 	}
599 
600 	if (dr == TAILQ_FIRST(&nd_defrouter))
601 		deldr = dr;	/* The router is primary. */
602 
603 	TAILQ_REMOVE(&nd_defrouter, dr, dr_entry);
604 
605 	/*
606 	 * Also delete all the pointers to the router in each prefix lists.
607 	 */
608 	for (pr = nd_prefix.lh_first; pr; pr = pr->ndpr_next) {
609 		struct nd_pfxrouter *pfxrtr;
610 		if ((pfxrtr = pfxrtr_lookup(pr, dr)) != NULL)
611 			pfxrtr_del(pfxrtr);
612 	}
613 	pfxlist_onlink_check();
614 
615 	/*
616 	 * If the router is the primary one, choose a new one.
617 	 * Note that defrouter_select() will remove the current gateway
618 	 * from the routing table.
619 	 */
620 	if (deldr)
621 		defrouter_select();
622 
623 	free(dr, M_IP6NDP);
624 }
625 
626 /*
627  * Default Router Selection according to Section 6.3.6 of RFC 2461:
628  * 1) Routers that are reachable or probably reachable should be
629  *    preferred.
630  * 2) When no routers on the list are known to be reachable or
631  *    probably reachable, routers SHOULD be selected in a round-robin
632  *    fashion.
633  * 3) If the Default Router List is empty, assume that all
634  *    destinations are on-link.
635  */
636 void
637 defrouter_select()
638 {
639 	int s = splnet();
640 	struct nd_defrouter *dr, anydr;
641 	struct rtentry *rt = NULL;
642 	struct llinfo_nd6 *ln = NULL;
643 
644 	/*
645 	 * Search for a (probably) reachable router from the list.
646 	 */
647 	for (dr = TAILQ_FIRST(&nd_defrouter); dr;
648 	     dr = TAILQ_NEXT(dr, dr_entry)) {
649 		if ((rt = nd6_lookup(&dr->rtaddr, 0, dr->ifp)) &&
650 		    (ln = (struct llinfo_nd6 *)rt->rt_llinfo) &&
651 		    ND6_IS_LLINFO_PROBREACH(ln)) {
652 			/* Got it, and move it to the head */
653 			TAILQ_REMOVE(&nd_defrouter, dr, dr_entry);
654 			TAILQ_INSERT_HEAD(&nd_defrouter, dr, dr_entry);
655 			break;
656 		}
657 	}
658 
659 	if ((dr = TAILQ_FIRST(&nd_defrouter))) {
660 		/*
661 		 * De-install the previous default gateway and install
662 		 * a new one.
663 		 * Note that if there is no reachable router in the list,
664 		 * the head entry will be used anyway.
665 		 * XXX: do we have to check the current routing table entry?
666 		 */
667 		bzero(&anydr, sizeof(anydr));
668 		defrouter_delreq(&anydr, 0);
669 		defrouter_addreq(dr);
670 	}
671 	else {
672 		/*
673 		 * The Default Router List is empty, so install the default
674 		 * route to an inteface.
675 		 * XXX: The specification does not say this mechanism should
676 		 * be restricted to hosts, but this would be not useful
677 		 * (even harmful) for routers.
678 		 */
679 		if (!ip6_forwarding) {
680 			/*
681 			 * De-install the current default route
682 			 * in advance.
683 			 */
684 			bzero(&anydr, sizeof(anydr));
685 			defrouter_delreq(&anydr, 0);
686 			if (nd6_defifp) {
687 				/*
688 				 * Install a route to the default interface
689 				 * as default route.
690 				 * XXX: we enable this for host only, because
691 				 * this may override a default route installed
692 				 * a user process (e.g. routing daemon) in a
693 				 * router case.
694 				 */
695 				defrouter_addifreq(nd6_defifp);
696 			} else {
697 				nd6log((LOG_INFO, "defrouter_select: "
698 				    "there's no default router and no default"
699 				    " interface\n"));
700 			}
701 		}
702 	}
703 
704 	splx(s);
705 	return;
706 }
707 
708 static struct nd_defrouter *
709 defrtrlist_update(new)
710 	struct nd_defrouter *new;
711 {
712 	struct nd_defrouter *dr, *n;
713 	int s = splnet();
714 
715 	if ((dr = defrouter_lookup(&new->rtaddr, new->ifp)) != NULL) {
716 		/* entry exists */
717 		if (new->rtlifetime == 0) {
718 			defrtrlist_del(dr);
719 			dr = NULL;
720 		} else {
721 			/* override */
722 			dr->flags = new->flags; /* xxx flag check */
723 			dr->rtlifetime = new->rtlifetime;
724 			dr->expire = new->expire;
725 		}
726 		splx(s);
727 		return(dr);
728 	}
729 
730 	/* entry does not exist */
731 	if (new->rtlifetime == 0) {
732 		splx(s);
733 		return(NULL);
734 	}
735 
736 	n = (struct nd_defrouter *)malloc(sizeof(*n), M_IP6NDP, M_NOWAIT);
737 	if (n == NULL) {
738 		splx(s);
739 		return(NULL);
740 	}
741 	bzero(n, sizeof(*n));
742 	*n = *new;
743 
744 	/*
745 	 * Insert the new router at the end of the Default Router List.
746 	 * If there is no other router, install it anyway. Otherwise,
747 	 * just continue to use the current default router.
748 	 */
749 	TAILQ_INSERT_TAIL(&nd_defrouter, n, dr_entry);
750 	if (TAILQ_FIRST(&nd_defrouter) == n)
751 		defrouter_select();
752 	splx(s);
753 
754 	return(n);
755 }
756 
757 static struct nd_pfxrouter *
758 pfxrtr_lookup(pr, dr)
759 	struct nd_prefix *pr;
760 	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(pr, dr)
774 	struct nd_prefix *pr;
775 	struct nd_defrouter *dr;
776 {
777 	struct nd_pfxrouter *new;
778 
779 	new = (struct nd_pfxrouter *)malloc(sizeof(*new), M_IP6NDP, M_NOWAIT);
780 	if (new == NULL)
781 		return;
782 	bzero(new, sizeof(*new));
783 	new->router = dr;
784 
785 	LIST_INSERT_HEAD(&pr->ndpr_advrtrs, new, pfr_entry);
786 
787 	pfxlist_onlink_check();
788 }
789 
790 static void
791 pfxrtr_del(pfr)
792 	struct nd_pfxrouter *pfr;
793 {
794 	LIST_REMOVE(pfr, pfr_entry);
795 	free(pfr, M_IP6NDP);
796 }
797 
798 struct nd_prefix *
799 nd6_prefix_lookup(pr)
800 	struct nd_prefix *pr;
801 {
802 	struct nd_prefix *search;
803 
804 	for (search = nd_prefix.lh_first; search; search = search->ndpr_next) {
805 		if (pr->ndpr_ifp == search->ndpr_ifp &&
806 		    pr->ndpr_plen == search->ndpr_plen &&
807 		    in6_are_prefix_equal(&pr->ndpr_prefix.sin6_addr,
808 					 &search->ndpr_prefix.sin6_addr,
809 					 pr->ndpr_plen)
810 		    ) {
811 			break;
812 		}
813 	}
814 
815 	return(search);
816 }
817 
818 int
819 nd6_prelist_add(pr, dr, newp)
820 	struct nd_prefix *pr, **newp;
821 	struct nd_defrouter *dr;
822 {
823 	struct nd_prefix *new = NULL;
824 	int i, s;
825 
826 	new = (struct nd_prefix *)malloc(sizeof(*new), M_IP6NDP, M_NOWAIT);
827 	if (new == NULL)
828 		return ENOMEM;
829 	bzero(new, sizeof(*new));
830 	*new = *pr;
831 	if (newp != NULL)
832 		*newp = new;
833 
834 	/* initilization */
835 	LIST_INIT(&new->ndpr_advrtrs);
836 	in6_prefixlen2mask(&new->ndpr_mask, new->ndpr_plen);
837 	/* make prefix in the canonical form */
838 	for (i = 0; i < 4; i++)
839 		new->ndpr_prefix.sin6_addr.s6_addr32[i] &=
840 			new->ndpr_mask.s6_addr32[i];
841 
842 	s = splnet();
843 	/* link ndpr_entry to nd_prefix list */
844 	LIST_INSERT_HEAD(&nd_prefix, new, ndpr_entry);
845 	splx(s);
846 
847 	/* ND_OPT_PI_FLAG_ONLINK processing */
848 	if (new->ndpr_raf_onlink) {
849 		int e;
850 
851 		if ((e = nd6_prefix_onlink(new)) != 0) {
852 			nd6log((LOG_ERR, "nd6_prelist_add: failed to make "
853 			    "the prefix %s/%d on-link on %s (errno=%d)\n",
854 			    ip6_sprintf(&pr->ndpr_prefix.sin6_addr),
855 			    pr->ndpr_plen, if_name(pr->ndpr_ifp), e));
856 			/* proceed anyway. XXX: is it correct? */
857 		}
858 	}
859 
860 	if (dr) {
861 		pfxrtr_add(new, dr);
862 	}
863 
864 	return 0;
865 }
866 
867 void
868 prelist_remove(pr)
869 	struct nd_prefix *pr;
870 {
871 	struct nd_pfxrouter *pfr, *next;
872 	int e, s;
873 
874 	/* make sure to invalidate the prefix until it is really freed. */
875 	pr->ndpr_vltime = 0;
876 	pr->ndpr_pltime = 0;
877 #if 0
878 	/*
879 	 * Though these flags are now meaningless, we'd rather keep the value
880 	 * not to confuse users when executing "ndp -p".
881 	 */
882 	pr->ndpr_raf_onlink = 0;
883 	pr->ndpr_raf_auto = 0;
884 #endif
885 	if ((pr->ndpr_stateflags & NDPRF_ONLINK) != 0 &&
886 	    (e = nd6_prefix_offlink(pr)) != 0) {
887 		nd6log((LOG_ERR, "prelist_remove: failed to make %s/%d offlink "
888 		    "on %s, errno=%d\n",
889 		    ip6_sprintf(&pr->ndpr_prefix.sin6_addr),
890 		    pr->ndpr_plen, if_name(pr->ndpr_ifp), e));
891 		/* what should we do? */
892 	}
893 
894 	if (pr->ndpr_refcnt > 0)
895 		return;		/* notice here? */
896 
897 	s = splnet();
898 
899 	/* unlink ndpr_entry from nd_prefix list */
900 	LIST_REMOVE(pr, ndpr_entry);
901 
902 	/* free list of routers that adversed the prefix */
903 	for (pfr = pr->ndpr_advrtrs.lh_first; pfr; pfr = next) {
904 		next = pfr->pfr_next;
905 
906 		free(pfr, M_IP6NDP);
907 	}
908 	splx(s);
909 
910 	free(pr, M_IP6NDP);
911 
912 	pfxlist_onlink_check();
913 }
914 
915 int
916 prelist_update(new, dr, m)
917 	struct nd_prefix *new;
918 	struct nd_defrouter *dr; /* may be NULL */
919 	struct mbuf *m;
920 {
921 	struct in6_ifaddr *ia6 = NULL, *ia6_match = NULL;
922 	struct ifaddr *ifa;
923 	struct ifnet *ifp = new->ndpr_ifp;
924 	struct nd_prefix *pr;
925 	int s = splnet();
926 	int error = 0;
927 	int newprefix = 0;
928 	int auth;
929 	struct in6_addrlifetime lt6_tmp;
930 
931 	auth = 0;
932 	if (m) {
933 		/*
934 		 * Authenticity for NA consists authentication for
935 		 * both IP header and IP datagrams, doesn't it ?
936 		 */
937 #if defined(M_AUTHIPHDR) && defined(M_AUTHIPDGM)
938 		auth = (m->m_flags & M_AUTHIPHDR
939 		     && m->m_flags & M_AUTHIPDGM) ? 1 : 0;
940 #endif
941 	}
942 
943 
944 	if ((pr = nd6_prefix_lookup(new)) != NULL) {
945 		/*
946 		 * nd6_prefix_lookup() ensures that pr and new have the same
947 		 * prefix on a same interface.
948 		 */
949 
950 		/*
951 		 * Update prefix information.  Note that the on-link (L) bit
952 		 * and the autonomous (A) bit should NOT be changed from 1
953 		 * to 0.
954 		 */
955 		if (new->ndpr_raf_onlink == 1)
956 			pr->ndpr_raf_onlink = 1;
957 		if (new->ndpr_raf_auto == 1)
958 			pr->ndpr_raf_auto = 1;
959 		if (new->ndpr_raf_onlink) {
960 			pr->ndpr_vltime = new->ndpr_vltime;
961 			pr->ndpr_pltime = new->ndpr_pltime;
962 			pr->ndpr_preferred = new->ndpr_preferred;
963 			pr->ndpr_expire = new->ndpr_expire;
964 		}
965 
966 		if (new->ndpr_raf_onlink &&
967 		    (pr->ndpr_stateflags & NDPRF_ONLINK) == 0) {
968 			int e;
969 
970 			if ((e = nd6_prefix_onlink(pr)) != 0) {
971 				nd6log((LOG_ERR,
972 				    "prelist_update: failed to make "
973 				    "the prefix %s/%d on-link on %s "
974 				    "(errno=%d)\n",
975 				    ip6_sprintf(&pr->ndpr_prefix.sin6_addr),
976 				    pr->ndpr_plen, if_name(pr->ndpr_ifp), e));
977 				/* proceed anyway. XXX: is it correct? */
978 			}
979 		}
980 
981 		if (dr && pfxrtr_lookup(pr, dr) == NULL)
982 			pfxrtr_add(pr, dr);
983 	} else {
984 		struct nd_prefix *newpr = NULL;
985 
986 		newprefix = 1;
987 
988 		if (new->ndpr_vltime == 0)
989 			goto end;
990 		if (new->ndpr_raf_onlink == 0 && new->ndpr_raf_auto == 0)
991 			goto end;
992 
993 		bzero(&new->ndpr_addr, sizeof(struct in6_addr));
994 
995 		error = nd6_prelist_add(new, dr, &newpr);
996 		if (error != 0 || newpr == NULL) {
997 			nd6log((LOG_NOTICE, "prelist_update: "
998 			    "nd6_prelist_add failed for %s/%d on %s "
999 			    "errno=%d, returnpr=%p\n",
1000 			    ip6_sprintf(&new->ndpr_prefix.sin6_addr),
1001 					new->ndpr_plen, if_name(new->ndpr_ifp),
1002 					error, newpr));
1003 			goto end; /* we should just give up in this case. */
1004 		}
1005 
1006 		/*
1007 		 * XXX: from the ND point of view, we can ignore a prefix
1008 		 * with the on-link bit being zero.  However, we need a
1009 		 * prefix structure for references from autoconfigured
1010 		 * addresses.  Thus, we explicitly make suret that the prefix
1011 		 * itself expires now.
1012 		 */
1013 		if (newpr->ndpr_raf_onlink == 0) {
1014 			newpr->ndpr_vltime = 0;
1015 			newpr->ndpr_pltime = 0;
1016 			in6_init_prefix_ltimes(newpr);
1017 		}
1018 
1019 		pr = newpr;
1020 	}
1021 
1022 	/*
1023 	 * Address autoconfiguration based on Section 5.5.3 of RFC 2462.
1024 	 * Note that pr must be non NULL at this point.
1025 	 */
1026 
1027 	/* 5.5.3 (a). Ignore the prefix without the A bit set. */
1028 	if (!new->ndpr_raf_auto)
1029 		goto afteraddrconf;
1030 
1031 	/*
1032 	 * 5.5.3 (b). the link-local prefix should have been ignored in
1033 	 * nd6_ra_input.
1034 	 */
1035 
1036 	/*
1037 	 * 5.5.3 (c). Consistency check on lifetimes: pltime <= vltime.
1038 	 * This should have been done in nd6_ra_input.
1039 	 */
1040 
1041  	/*
1042 	 * 5.5.3 (d). If the prefix advertised does not match the prefix of an
1043 	 * address already in the list, and the Valid Lifetime is not 0,
1044 	 * form an address.  Note that even a manually configured address
1045 	 * should reject autoconfiguration of a new address.
1046 	 */
1047 	TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list)
1048 	{
1049 		struct in6_ifaddr *ifa6;
1050 		int ifa_plen;
1051 		u_int32_t storedlifetime;
1052 
1053 		if (ifa->ifa_addr->sa_family != AF_INET6)
1054 			continue;
1055 
1056 		ifa6 = (struct in6_ifaddr *)ifa;
1057 
1058 		/*
1059 		 * Spec is not clear here, but I believe we should concentrate
1060 		 * on unicast (i.e. not anycast) addresses.
1061 		 * XXX: other ia6_flags? detached or duplicated?
1062 		 */
1063 		if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0)
1064 			continue;
1065 
1066 		ifa_plen = in6_mask2len(&ifa6->ia_prefixmask.sin6_addr, NULL);
1067 		if (ifa_plen != new->ndpr_plen ||
1068 		    !in6_are_prefix_equal(&ifa6->ia_addr.sin6_addr,
1069 					  &new->ndpr_prefix.sin6_addr,
1070 					  ifa_plen))
1071 			continue;
1072 
1073 		if (ia6_match == NULL) /* remember the first one */
1074 			ia6_match = ifa6;
1075 
1076 		if ((ifa6->ia6_flags & IN6_IFF_AUTOCONF) == 0)
1077 			continue;
1078 
1079 		/*
1080 		 * An already autoconfigured address matched.  Now that we
1081 		 * are sure there is at least one matched address, we can
1082 		 * proceed to 5.5.3. (e): update the lifetimes according to the
1083 		 * "two hours" rule and the privacy extension.
1084 		 */
1085 #define TWOHOUR		(120*60)
1086 		lt6_tmp = ifa6->ia6_lifetime;
1087 
1088 		if (lt6_tmp.ia6t_vltime == ND6_INFINITE_LIFETIME)
1089 			storedlifetime = ND6_INFINITE_LIFETIME;
1090 		else if (IFA6_IS_INVALID(ifa6))
1091 			storedlifetime = 0;
1092 		else
1093 			storedlifetime = lt6_tmp.ia6t_expire - time_second;
1094 
1095 		/* when not updating, keep the current stored lifetime. */
1096 		lt6_tmp.ia6t_vltime = storedlifetime;
1097 
1098 		if (TWOHOUR < new->ndpr_vltime ||
1099 		    storedlifetime < new->ndpr_vltime) {
1100 			lt6_tmp.ia6t_vltime = new->ndpr_vltime;
1101 		} else if (storedlifetime <= TWOHOUR
1102 #if 0
1103 			   /*
1104 			    * This condition is logically redundant, so we just
1105 			    * omit it.
1106 			    * See IPng 6712, 6717, and 6721.
1107 			    */
1108 			   && new->ndpr_vltime <= storedlifetime
1109 #endif
1110 			) {
1111 			if (auth) {
1112 				lt6_tmp.ia6t_vltime = new->ndpr_vltime;
1113 			}
1114 		} else {
1115 			/*
1116 			 * new->ndpr_vltime <= TWOHOUR &&
1117 			 * TWOHOUR < storedlifetime
1118 			 */
1119 			lt6_tmp.ia6t_vltime = TWOHOUR;
1120 		}
1121 
1122 		/* The 2 hour rule is not imposed for preferred lifetime. */
1123 		lt6_tmp.ia6t_pltime = new->ndpr_pltime;
1124 
1125 		in6_init_address_ltimes(pr, &lt6_tmp);
1126 
1127 		/*
1128 		 * When adjusting the lifetimes of an existing temporary
1129 		 * address, only lower the lifetimes.
1130 		 * RFC 3041 3.3. (1).
1131 		 * XXX: how should we modify ia6t_[pv]ltime?
1132 		 */
1133 		if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0) {
1134 			if (lt6_tmp.ia6t_expire == 0 || /* no expire */
1135 			    lt6_tmp.ia6t_expire >
1136 			    ifa6->ia6_lifetime.ia6t_expire) {
1137 				lt6_tmp.ia6t_expire =
1138 					ifa6->ia6_lifetime.ia6t_expire;
1139 			}
1140 			if (lt6_tmp.ia6t_preferred == 0 || /* no expire */
1141 			    lt6_tmp.ia6t_preferred >
1142 			    ifa6->ia6_lifetime.ia6t_preferred) {
1143 				lt6_tmp.ia6t_preferred =
1144 					ifa6->ia6_lifetime.ia6t_preferred;
1145 			}
1146 		}
1147 
1148 		ifa6->ia6_lifetime = lt6_tmp;
1149 	}
1150 	if (ia6_match == NULL && new->ndpr_vltime) {
1151 		/*
1152 		 * No address matched and the valid lifetime is non-zero.
1153 		 * Create a new address.
1154 		 */
1155 		if ((ia6 = in6_ifadd(new, NULL)) != NULL) {
1156 			/*
1157 			 * note that we should use pr (not new) for reference.
1158 			 */
1159 			pr->ndpr_refcnt++;
1160 			ia6->ia6_ndpr = pr;
1161 
1162 #if 0
1163 			/* XXXYYY Don't do this, according to Jinmei. */
1164 			pr->ndpr_addr = new->ndpr_addr;
1165 #endif
1166 
1167 			/*
1168 			 * RFC 3041 3.3 (2).
1169 			 * When a new public address is created as described
1170 			 * in RFC2462, also create a new temporary address.
1171 			 *
1172 			 * RFC 3041 3.5.
1173 			 * When an interface connects to a new link, a new
1174 			 * randomized interface identifier should be generated
1175 			 * immediately together with a new set of temporary
1176 			 * addresses.  Thus, we specifiy 1 as the 2nd arg of
1177 			 * in6_tmpifadd().
1178 			 */
1179 			if (ip6_use_tempaddr) {
1180 				int e;
1181 				if ((e = in6_tmpifadd(ia6, 1)) != 0) {
1182 					nd6log((LOG_NOTICE, "prelist_update: "
1183 					    "failed to create a temporary "
1184 					    "address, errno=%d\n",
1185 					    e));
1186 				}
1187 			}
1188 
1189 			/*
1190 			 * A newly added address might affect the status
1191 			 * of other addresses, so we check and update it.
1192 			 * XXX: what if address duplication happens?
1193 			 */
1194 			pfxlist_onlink_check();
1195 		} else {
1196 			/* just set an error. do not bark here. */
1197 			error = EADDRNOTAVAIL; /* XXX: might be unused. */
1198 		}
1199 	}
1200 
1201   afteraddrconf:
1202 
1203  end:
1204 	splx(s);
1205 	return error;
1206 }
1207 
1208 /*
1209  * A supplement function used in the on-link detection below;
1210  * detect if a given prefix has a (probably) reachable advertising router.
1211  * XXX: lengthy function name...
1212  */
1213 static struct nd_pfxrouter *
1214 find_pfxlist_reachable_router(pr)
1215 	struct nd_prefix *pr;
1216 {
1217 	struct nd_pfxrouter *pfxrtr;
1218 	struct rtentry *rt;
1219 	struct llinfo_nd6 *ln;
1220 
1221 	for (pfxrtr = LIST_FIRST(&pr->ndpr_advrtrs); pfxrtr;
1222 	     pfxrtr = LIST_NEXT(pfxrtr, pfr_entry)) {
1223 		if ((rt = nd6_lookup(&pfxrtr->router->rtaddr, 0,
1224 				     pfxrtr->router->ifp)) &&
1225 		    (ln = (struct llinfo_nd6 *)rt->rt_llinfo) &&
1226 		    ND6_IS_LLINFO_PROBREACH(ln))
1227 			break;	/* found */
1228 	}
1229 
1230 	return(pfxrtr);
1231 
1232 }
1233 
1234 /*
1235  * Check if each prefix in the prefix list has at least one available router
1236  * that advertised the prefix (a router is "available" if its neighbor cache
1237  * entry is reachable or probably reachable).
1238  * If the check fails, the prefix may be off-link, because, for example,
1239  * we have moved from the network but the lifetime of the prefix has not
1240  * expired yet.  So we should not use the prefix if there is another prefix
1241  * that has an available router.
1242  * But, if there is no prefix that has an available router, we still regards
1243  * all the prefixes as on-link.  This is because we can't tell if all the
1244  * routers are simply dead or if we really moved from the network and there
1245  * is no router around us.
1246  */
1247 void
1248 pfxlist_onlink_check()
1249 {
1250 	struct nd_prefix *pr;
1251 	struct in6_ifaddr *ifa;
1252 
1253 	/*
1254 	 * Check if there is a prefix that has a reachable advertising
1255 	 * router.
1256 	 */
1257 	for (pr = nd_prefix.lh_first; pr; pr = pr->ndpr_next) {
1258 		if (pr->ndpr_raf_onlink && find_pfxlist_reachable_router(pr))
1259 			break;
1260 	}
1261 
1262 	if (pr) {
1263 		/*
1264 		 * There is at least one prefix that has a reachable router.
1265 		 * Detach prefixes which have no reachable advertising
1266 		 * router, and attach other prefixes.
1267 		 */
1268 		for (pr = nd_prefix.lh_first; pr; pr = pr->ndpr_next) {
1269 			/* XXX: a link-local prefix should never be detached */
1270 			if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr))
1271 				continue;
1272 
1273 			/*
1274 			 * we aren't interested in prefixes without the L bit
1275 			 * set.
1276 			 */
1277 			if (pr->ndpr_raf_onlink == 0)
1278 				continue;
1279 
1280 			if ((pr->ndpr_stateflags & NDPRF_DETACHED) == 0 &&
1281 			    find_pfxlist_reachable_router(pr) == NULL)
1282 				pr->ndpr_stateflags |= NDPRF_DETACHED;
1283 			if ((pr->ndpr_stateflags & NDPRF_DETACHED) != 0 &&
1284 			    find_pfxlist_reachable_router(pr) != 0)
1285 				pr->ndpr_stateflags &= ~NDPRF_DETACHED;
1286 		}
1287 	} else {
1288 		/* there is no prefix that has a reachable router */
1289 		for (pr = nd_prefix.lh_first; pr; pr = pr->ndpr_next) {
1290 			if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr))
1291 				continue;
1292 
1293 			if (pr->ndpr_raf_onlink == 0)
1294 				continue;
1295 
1296 			if ((pr->ndpr_stateflags & NDPRF_DETACHED) != 0)
1297 				pr->ndpr_stateflags &= ~NDPRF_DETACHED;
1298 		}
1299 	}
1300 
1301 	/*
1302 	 * Remove each interface route associated with a (just) detached
1303 	 * prefix, and reinstall the interface route for a (just) attached
1304 	 * prefix.  Note that all attempt of reinstallation does not
1305 	 * necessarily success, when a same prefix is shared among multiple
1306 	 * interfaces.  Such cases will be handled in nd6_prefix_onlink,
1307 	 * so we don't have to care about them.
1308 	 */
1309 	for (pr = nd_prefix.lh_first; pr; pr = pr->ndpr_next) {
1310 		int e;
1311 
1312 		if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr))
1313 			continue;
1314 
1315 		if (pr->ndpr_raf_onlink == 0)
1316 			continue;
1317 
1318 		if ((pr->ndpr_stateflags & NDPRF_DETACHED) != 0 &&
1319 		    (pr->ndpr_stateflags & NDPRF_ONLINK) != 0) {
1320 			if ((e = nd6_prefix_offlink(pr)) != 0) {
1321 				nd6log((LOG_ERR,
1322 				    "pfxlist_onlink_check: failed to "
1323 				    "make %s/%d offlink, errno=%d\n",
1324 				    ip6_sprintf(&pr->ndpr_prefix.sin6_addr),
1325 				    pr->ndpr_plen, e));
1326 			}
1327 		}
1328 		if ((pr->ndpr_stateflags & NDPRF_DETACHED) == 0 &&
1329 		    (pr->ndpr_stateflags & NDPRF_ONLINK) == 0 &&
1330 		    pr->ndpr_raf_onlink) {
1331 			if ((e = nd6_prefix_onlink(pr)) != 0) {
1332 				nd6log((LOG_ERR,
1333 				    "pfxlist_onlink_check: failed to "
1334 				    "make %s/%d offlink, errno=%d\n",
1335 				    ip6_sprintf(&pr->ndpr_prefix.sin6_addr),
1336 				    pr->ndpr_plen, e));
1337 			}
1338 		}
1339 	}
1340 
1341 	/*
1342 	 * Changes on the prefix status might affect address status as well.
1343 	 * Make sure that all addresses derived from an attached prefix are
1344 	 * attached, and that all addresses derived from a detached prefix are
1345 	 * detached.  Note, however, that a manually configured address should
1346 	 * always be attached.
1347 	 * The precise detection logic is same as the one for prefixes.
1348 	 */
1349 	for (ifa = in6_ifaddr; ifa; ifa = ifa->ia_next) {
1350 		if ((ifa->ia6_flags & IN6_IFF_AUTOCONF) == 0)
1351 			continue;
1352 
1353 		if (ifa->ia6_ndpr == NULL) {
1354 			/*
1355 			 * This can happen when we first configure the address
1356 			 * (i.e. the address exists, but the prefix does not).
1357 			 * XXX: complicated relationships...
1358 			 */
1359 			continue;
1360 		}
1361 
1362 		if (find_pfxlist_reachable_router(ifa->ia6_ndpr))
1363 			break;
1364 	}
1365 	if (ifa) {
1366 		for (ifa = in6_ifaddr; ifa; ifa = ifa->ia_next) {
1367 			if ((ifa->ia6_flags & IN6_IFF_AUTOCONF) == 0)
1368 				continue;
1369 
1370 			if (ifa->ia6_ndpr == NULL) /* XXX: see above. */
1371 				continue;
1372 
1373 			if (find_pfxlist_reachable_router(ifa->ia6_ndpr))
1374 				ifa->ia6_flags &= ~IN6_IFF_DETACHED;
1375 			else
1376 				ifa->ia6_flags |= IN6_IFF_DETACHED;
1377 		}
1378 	}
1379 	else {
1380 		for (ifa = in6_ifaddr; ifa; ifa = ifa->ia_next) {
1381 			if ((ifa->ia6_flags & IN6_IFF_AUTOCONF) == 0)
1382 				continue;
1383 
1384 			ifa->ia6_flags &= ~IN6_IFF_DETACHED;
1385 		}
1386 	}
1387 }
1388 
1389 int
1390 nd6_prefix_onlink(pr)
1391 	struct nd_prefix *pr;
1392 {
1393 	struct ifaddr *ifa;
1394 	struct ifnet *ifp = pr->ndpr_ifp;
1395 	struct sockaddr_in6 mask6;
1396 	struct nd_prefix *opr;
1397 	u_long rtflags;
1398 	int error = 0;
1399 	struct rtentry *rt = NULL;
1400 
1401 	/* sanity check */
1402 	if ((pr->ndpr_stateflags & NDPRF_ONLINK) != 0) {
1403 		nd6log((LOG_ERR,
1404 		    "nd6_prefix_onlink: %s/%d is already on-link\n",
1405 		    ip6_sprintf(&pr->ndpr_prefix.sin6_addr), pr->ndpr_plen);
1406 		return(EEXIST));
1407 	}
1408 
1409 	/*
1410 	 * Add the interface route associated with the prefix.  Before
1411 	 * installing the route, check if there's the same prefix on another
1412 	 * interface, and the prefix has already installed the interface route.
1413 	 * Although such a configuration is expected to be rare, we explicitly
1414 	 * allow it.
1415 	 */
1416 	for (opr = nd_prefix.lh_first; opr; opr = opr->ndpr_next) {
1417 		if (opr == pr)
1418 			continue;
1419 
1420 		if ((opr->ndpr_stateflags & NDPRF_ONLINK) == 0)
1421 			continue;
1422 
1423 		if (opr->ndpr_plen == pr->ndpr_plen &&
1424 		    in6_are_prefix_equal(&pr->ndpr_prefix.sin6_addr,
1425 					 &opr->ndpr_prefix.sin6_addr,
1426 					 pr->ndpr_plen))
1427 			return(0);
1428 	}
1429 
1430 	/*
1431 	 * We prefer link-local addresses as the associated interface address.
1432 	 */
1433 	/* search for a link-local addr */
1434 	ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp,
1435 						      IN6_IFF_NOTREADY|
1436 						      IN6_IFF_ANYCAST);
1437 	if (ifa == NULL) {
1438 		/* XXX: freebsd does not have ifa_ifwithaf */
1439 		TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list)
1440 		{
1441 			if (ifa->ifa_addr->sa_family == AF_INET6)
1442 				break;
1443 		}
1444 		/* should we care about ia6_flags? */
1445 	}
1446 	if (ifa == NULL) {
1447 		/*
1448 		 * This can still happen, when, for example, we receive an RA
1449 		 * containing a prefix with the L bit set and the A bit clear,
1450 		 * after removing all IPv6 addresses on the receiving
1451 		 * interface.  This should, of course, be rare though.
1452 		 */
1453 		nd6log((LOG_NOTICE,
1454 		    "nd6_prefix_onlink: failed to find any ifaddr"
1455 		    " to add route for a prefix(%s/%d) on %s\n",
1456 		    ip6_sprintf(&pr->ndpr_prefix.sin6_addr),
1457 		    pr->ndpr_plen, if_name(ifp)));
1458 		return(0);
1459 	}
1460 
1461 	/*
1462 	 * in6_ifinit() sets nd6_rtrequest to ifa_rtrequest for all ifaddrs.
1463 	 * ifa->ifa_rtrequest = nd6_rtrequest;
1464 	 */
1465 	bzero(&mask6, sizeof(mask6));
1466 	mask6.sin6_len = sizeof(mask6);
1467 	mask6.sin6_addr = pr->ndpr_mask;
1468 	rtflags = ifa->ifa_flags | RTF_CLONING | RTF_UP;
1469 	if (nd6_need_cache(ifp)) {
1470 		/* explicitly set in case ifa_flags does not set the flag. */
1471 		rtflags |= RTF_CLONING;
1472 	} else {
1473 		/*
1474 		 * explicitly clear the cloning bit in case ifa_flags sets it.
1475 		 */
1476 		rtflags &= ~RTF_CLONING;
1477 	}
1478 	error = rtrequest(RTM_ADD, (struct sockaddr *)&pr->ndpr_prefix,
1479 			  ifa->ifa_addr, (struct sockaddr *)&mask6,
1480 			  rtflags, &rt);
1481 	if (error == 0) {
1482 		if (rt != NULL) /* this should be non NULL, though */
1483 			nd6_rtmsg(RTM_ADD, rt);
1484 		pr->ndpr_stateflags |= NDPRF_ONLINK;
1485 	}
1486 	else {
1487 		nd6log((LOG_ERR, "nd6_prefix_onlink: failed to add route for a"
1488 		    " prefix (%s/%d) on %s, gw=%s, mask=%s, flags=%lx "
1489 		    "errno = %d\n",
1490 		    ip6_sprintf(&pr->ndpr_prefix.sin6_addr),
1491 		    pr->ndpr_plen, if_name(ifp),
1492 		    ip6_sprintf(&((struct sockaddr_in6 *)ifa->ifa_addr)->sin6_addr),
1493 		    ip6_sprintf(&mask6.sin6_addr), rtflags, error));
1494 	}
1495 
1496 	if (rt != NULL)
1497 		rt->rt_refcnt--;
1498 
1499 	return(error);
1500 }
1501 
1502 int
1503 nd6_prefix_offlink(pr)
1504 	struct nd_prefix *pr;
1505 {
1506 	int error = 0;
1507 	struct ifnet *ifp = pr->ndpr_ifp;
1508 	struct nd_prefix *opr;
1509 	struct sockaddr_in6 sa6, mask6;
1510 	struct rtentry *rt = NULL;
1511 
1512 	/* sanity check */
1513 	if ((pr->ndpr_stateflags & NDPRF_ONLINK) == 0) {
1514 		nd6log((LOG_ERR,
1515 		    "nd6_prefix_offlink: %s/%d is already off-link\n",
1516 		    ip6_sprintf(&pr->ndpr_prefix.sin6_addr), pr->ndpr_plen));
1517 		return(EEXIST);
1518 	}
1519 
1520 	bzero(&sa6, sizeof(sa6));
1521 	sa6.sin6_family = AF_INET6;
1522 	sa6.sin6_len = sizeof(sa6);
1523 	bcopy(&pr->ndpr_prefix.sin6_addr, &sa6.sin6_addr,
1524 	      sizeof(struct in6_addr));
1525 	bzero(&mask6, sizeof(mask6));
1526 	mask6.sin6_family = AF_INET6;
1527 	mask6.sin6_len = sizeof(sa6);
1528 	bcopy(&pr->ndpr_mask, &mask6.sin6_addr, sizeof(struct in6_addr));
1529 	error = rtrequest(RTM_DELETE, (struct sockaddr *)&sa6, NULL,
1530 			  (struct sockaddr *)&mask6, 0, &rt);
1531 	if (error == 0) {
1532 		pr->ndpr_stateflags &= ~NDPRF_ONLINK;
1533 
1534 		/* report the route deletion to the routing socket. */
1535 		if (rt != NULL)
1536 			nd6_rtmsg(RTM_DELETE, rt);
1537 
1538 		/*
1539 		 * There might be the same prefix on another interface,
1540 		 * the prefix which could not be on-link just because we have
1541 		 * the interface route (see comments in nd6_prefix_onlink).
1542 		 * If there's one, try to make the prefix on-link on the
1543 		 * interface.
1544 		 */
1545 		for (opr = nd_prefix.lh_first; opr; opr = opr->ndpr_next) {
1546 			if (opr == pr)
1547 				continue;
1548 
1549 			if ((opr->ndpr_stateflags & NDPRF_ONLINK) != 0)
1550 				continue;
1551 
1552 			/*
1553 			 * KAME specific: detached prefixes should not be
1554 			 * on-link.
1555 			 */
1556 			if ((opr->ndpr_stateflags & NDPRF_DETACHED) != 0)
1557 				continue;
1558 
1559 			if (opr->ndpr_plen == pr->ndpr_plen &&
1560 			    in6_are_prefix_equal(&pr->ndpr_prefix.sin6_addr,
1561 						 &opr->ndpr_prefix.sin6_addr,
1562 						 pr->ndpr_plen)) {
1563 				int e;
1564 
1565 				if ((e = nd6_prefix_onlink(opr)) != 0) {
1566 					nd6log((LOG_ERR,
1567 					    "nd6_prefix_offlink: failed to "
1568 					    "recover a prefix %s/%d from %s "
1569 					    "to %s (errno = %d)\n",
1570 					    ip6_sprintf(&opr->ndpr_prefix.sin6_addr),
1571 					    opr->ndpr_plen, if_name(ifp),
1572 					    if_name(opr->ndpr_ifp), e));
1573 				}
1574 			}
1575 		}
1576 	}
1577 	else {
1578 		/* XXX: can we still set the NDPRF_ONLINK flag? */
1579 		nd6log((LOG_ERR,
1580 		    "nd6_prefix_offlink: failed to delete route: "
1581 		    "%s/%d on %s (errno = %d)\n",
1582 		    ip6_sprintf(&sa6.sin6_addr), pr->ndpr_plen, if_name(ifp),
1583 		    error));
1584 	}
1585 
1586 	if (rt != NULL)
1587 		RTFREE(rt);
1588 
1589 	return(error);
1590 }
1591 
1592 static struct in6_ifaddr *
1593 in6_ifadd(pr, ifid)
1594 	struct nd_prefix *pr;
1595 	struct in6_addr  *ifid;   /* Mobile IPv6 addition */
1596 {
1597 	struct ifnet *ifp = pr->ndpr_ifp;
1598 	struct ifaddr *ifa;
1599 	struct in6_aliasreq ifra;
1600 	struct in6_ifaddr *ia, *ib;
1601 	int error, plen0;
1602 	struct in6_addr mask;
1603 	int prefixlen = pr->ndpr_plen;
1604 
1605 	in6_len2mask(&mask, prefixlen);
1606 
1607 	/*
1608 	 * find a link-local address (will be interface ID).
1609 	 * Is it really mandatory? Theoretically, a global or a site-local
1610 	 * address can be configured without a link-local address, if we
1611 	 * have a unique interface identifier...
1612 	 *
1613 	 * it is not mandatory to have a link-local address, we can generate
1614 	 * interface identifier on the fly.  we do this because:
1615 	 * (1) it should be the easiest way to find interface identifier.
1616 	 * (2) RFC2462 5.4 suggesting the use of the same interface identifier
1617 	 * for multiple addresses on a single interface, and possible shortcut
1618 	 * of DAD.  we omitted DAD for this reason in the past.
1619 	 * (3) a user can prevent autoconfiguration of global address
1620 	 * by removing link-local address by hand (this is partly because we
1621 	 * don't have other way to control the use of IPv6 on an interface.
1622 	 * this has been our design choice - cf. NRL's "ifconfig auto").
1623 	 * (4) it is easier to manage when an interface has addresses
1624 	 * with the same interface identifier, than to have multiple addresses
1625 	 * with different interface identifiers.
1626 	 *
1627 	 * Mobile IPv6 addition: allow for caller to specify a wished interface
1628 	 * ID. This is to not break connections when moving addresses between
1629 	 * interfaces.
1630 	 */
1631 	ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp, 0);/* 0 is OK? */
1632 	if (ifa)
1633 		ib = (struct in6_ifaddr *)ifa;
1634 	else
1635 		return NULL;
1636 
1637 #if 0 /* don't care link local addr state, and always do DAD */
1638 	/* if link-local address is not eligible, do not autoconfigure. */
1639 	if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_NOTREADY) {
1640 		printf("in6_ifadd: link-local address not ready\n");
1641 		return NULL;
1642 	}
1643 #endif
1644 
1645 	/* prefixlen + ifidlen must be equal to 128 */
1646 	plen0 = in6_mask2len(&ib->ia_prefixmask.sin6_addr, NULL);
1647 	if (prefixlen != plen0) {
1648 		nd6log((LOG_INFO, "in6_ifadd: wrong prefixlen for %s "
1649 		    "(prefix=%d ifid=%d)\n",
1650 		    if_name(ifp), prefixlen, 128 - plen0));
1651 		return NULL;
1652 	}
1653 
1654 	/* make ifaddr */
1655 
1656 	bzero(&ifra, sizeof(ifra));
1657 	/*
1658 	 * in6_update_ifa() does not use ifra_name, but we accurately set it
1659 	 * for safety.
1660 	 */
1661 	strncpy(ifra.ifra_name, if_name(ifp), sizeof(ifra.ifra_name));
1662 	ifra.ifra_addr.sin6_family = AF_INET6;
1663 	ifra.ifra_addr.sin6_len = sizeof(struct sockaddr_in6);
1664 	/* prefix */
1665 	bcopy(&pr->ndpr_prefix.sin6_addr, &ifra.ifra_addr.sin6_addr,
1666 	      sizeof(ifra.ifra_addr.sin6_addr));
1667 	ifra.ifra_addr.sin6_addr.s6_addr32[0] &= mask.s6_addr32[0];
1668 	ifra.ifra_addr.sin6_addr.s6_addr32[1] &= mask.s6_addr32[1];
1669 	ifra.ifra_addr.sin6_addr.s6_addr32[2] &= mask.s6_addr32[2];
1670 	ifra.ifra_addr.sin6_addr.s6_addr32[3] &= mask.s6_addr32[3];
1671 
1672 	/* interface ID */
1673 	if (ifid == NULL || IN6_IS_ADDR_UNSPECIFIED(ifid))
1674 		ifid = &ib->ia_addr.sin6_addr;
1675 	ifra.ifra_addr.sin6_addr.s6_addr32[0]
1676 		|= (ifid->s6_addr32[0] & ~mask.s6_addr32[0]);
1677 	ifra.ifra_addr.sin6_addr.s6_addr32[1]
1678 		|= (ifid->s6_addr32[1] & ~mask.s6_addr32[1]);
1679 	ifra.ifra_addr.sin6_addr.s6_addr32[2]
1680 		|= (ifid->s6_addr32[2] & ~mask.s6_addr32[2]);
1681 	ifra.ifra_addr.sin6_addr.s6_addr32[3]
1682 		|= (ifid->s6_addr32[3] & ~mask.s6_addr32[3]);
1683 
1684 	/* new prefix mask. */
1685 	ifra.ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6);
1686 	ifra.ifra_prefixmask.sin6_family = AF_INET6;
1687 	bcopy(&mask, &ifra.ifra_prefixmask.sin6_addr,
1688 	      sizeof(ifra.ifra_prefixmask.sin6_addr));
1689 
1690 	/*
1691 	 * lifetime.
1692 	 * XXX: in6_init_address_ltimes would override these values later.
1693 	 * We should reconsider this logic.
1694 	 */
1695 	ifra.ifra_lifetime.ia6t_vltime = pr->ndpr_vltime;
1696 	ifra.ifra_lifetime.ia6t_pltime = pr->ndpr_pltime;
1697 
1698 	/* XXX: scope zone ID? */
1699 
1700 	ifra.ifra_flags |= IN6_IFF_AUTOCONF; /* obey autoconf */
1701 	/*
1702 	 * temporarily set the nopfx flag to avoid conflict.
1703 	 * XXX: we should reconsider the entire mechanism about prefix
1704 	 * manipulation.
1705 	 */
1706 	ifra.ifra_flags |= IN6_IFF_NOPFX;
1707 
1708 	/*
1709 	 * keep the new address, regardless of the result of in6_update_ifa.
1710 	 * XXX: this address is now meaningless.
1711 	 * We should reconsider its role.
1712 	 */
1713 	pr->ndpr_addr = ifra.ifra_addr.sin6_addr;
1714 
1715 	/* allocate ifaddr structure, link into chain, etc. */
1716 	if ((error = in6_update_ifa(ifp, &ifra, NULL)) != 0) {
1717 		nd6log((LOG_ERR,
1718 		    "in6_ifadd: failed to make ifaddr %s on %s (errno=%d)\n",
1719 		    ip6_sprintf(&ifra.ifra_addr.sin6_addr), if_name(ifp),
1720 		    error));
1721 		return(NULL);	/* ifaddr must not have been allocated. */
1722 	}
1723 
1724 	ia = in6ifa_ifpwithaddr(ifp, &ifra.ifra_addr.sin6_addr);
1725 
1726 	return(ia);		/* this must NOT be NULL. */
1727 }
1728 
1729 int
1730 in6_tmpifadd(ia0, forcegen)
1731 	const struct in6_ifaddr *ia0; /* corresponding public address */
1732 	int forcegen;
1733 {
1734 	struct ifnet *ifp = ia0->ia_ifa.ifa_ifp;
1735 	struct in6_ifaddr *newia;
1736 	struct in6_aliasreq ifra;
1737 	int i, error;
1738 	int trylimit = 3;	/* XXX: adhoc value */
1739 	u_int32_t randid[2];
1740 	time_t vltime0, pltime0;
1741 
1742 	bzero(&ifra, sizeof(ifra));
1743 	strncpy(ifra.ifra_name, if_name(ifp), sizeof(ifra.ifra_name));
1744 	ifra.ifra_addr = ia0->ia_addr;
1745 	/* copy prefix mask */
1746 	ifra.ifra_prefixmask = ia0->ia_prefixmask;
1747 	/* clear the old IFID */
1748 	for (i = 0; i < 4; i++) {
1749 		ifra.ifra_addr.sin6_addr.s6_addr32[i]
1750 			&= ifra.ifra_prefixmask.sin6_addr.s6_addr32[i];
1751 	}
1752 
1753   again:
1754 	in6_get_tmpifid(ifp, (u_int8_t *)randid,
1755 			(const u_int8_t *)&ia0->ia_addr.sin6_addr.s6_addr[8],
1756 			forcegen);
1757 	ifra.ifra_addr.sin6_addr.s6_addr32[2]
1758 		|= (randid[0] & ~(ifra.ifra_prefixmask.sin6_addr.s6_addr32[2]));
1759 	ifra.ifra_addr.sin6_addr.s6_addr32[3]
1760 		|= (randid[1] & ~(ifra.ifra_prefixmask.sin6_addr.s6_addr32[3]));
1761 
1762 	/*
1763 	 * If by chance the new temporary address is the same as an address
1764 	 * already assigned to the interface, generate a new randomized
1765 	 * interface identifier and repeat this step.
1766 	 * RFC 3041 3.3 (4).
1767 	 */
1768 	if (in6ifa_ifpwithaddr(ifp, &ifra.ifra_addr.sin6_addr) != NULL) {
1769 		if (trylimit-- == 0) {
1770 			nd6log((LOG_NOTICE, "in6_tmpifadd: failed to find "
1771 			    "a unique random IFID\n"));
1772 			return(EEXIST);
1773 		}
1774 		forcegen = 1;
1775 		goto again;
1776 	}
1777 
1778 	/*
1779 	 * The Valid Lifetime is the lower of the Valid Lifetime of the
1780          * public address or TEMP_VALID_LIFETIME.
1781 	 * The Preferred Lifetime is the lower of the Preferred Lifetime
1782          * of the public address or TEMP_PREFERRED_LIFETIME -
1783          * DESYNC_FACTOR.
1784 	 */
1785 	if (ia0->ia6_lifetime.ia6t_expire != 0) {
1786 		vltime0 = IFA6_IS_INVALID(ia0) ? 0 :
1787 			(ia0->ia6_lifetime.ia6t_expire - time_second);
1788 		if (vltime0 > ip6_temp_valid_lifetime)
1789 			vltime0 = ip6_temp_valid_lifetime;
1790 	} else
1791 		vltime0 = ip6_temp_valid_lifetime;
1792 	if (ia0->ia6_lifetime.ia6t_preferred != 0) {
1793 		pltime0 = IFA6_IS_DEPRECATED(ia0) ? 0 :
1794 			(ia0->ia6_lifetime.ia6t_preferred - time_second);
1795 		if (pltime0 > ip6_temp_preferred_lifetime - ip6_desync_factor){
1796 			pltime0 = ip6_temp_preferred_lifetime -
1797 				ip6_desync_factor;
1798 		}
1799 	} else
1800 		pltime0 = ip6_temp_preferred_lifetime - ip6_desync_factor;
1801 	ifra.ifra_lifetime.ia6t_vltime = vltime0;
1802 	ifra.ifra_lifetime.ia6t_pltime = pltime0;
1803 
1804 	/*
1805 	 * A temporary address is created only if this calculated Preferred
1806 	 * Lifetime is greater than REGEN_ADVANCE time units.
1807 	 */
1808 	if (ifra.ifra_lifetime.ia6t_pltime <= ip6_temp_regen_advance)
1809 		return(0);
1810 
1811 	/* XXX: scope zone ID? */
1812 
1813 	ifra.ifra_flags |= (IN6_IFF_AUTOCONF|IN6_IFF_TEMPORARY);
1814 
1815 	/* allocate ifaddr structure, link into chain, etc. */
1816 	if ((error = in6_update_ifa(ifp, &ifra, NULL)) != 0)
1817 		return(error);
1818 
1819 	newia = in6ifa_ifpwithaddr(ifp, &ifra.ifra_addr.sin6_addr);
1820 	if (newia == NULL) {	/* XXX: can it happen? */
1821 		nd6log((LOG_ERR,
1822 		    "in6_tmpifadd: ifa update succeeded, but we got "
1823 		    "no ifaddr\n"));
1824 		return(EINVAL); /* XXX */
1825 	}
1826 	newia->ia6_ndpr = ia0->ia6_ndpr;
1827 	newia->ia6_ndpr->ndpr_refcnt++;
1828 
1829 	/*
1830 	 * A newly added address might affect the status of other addresses.
1831 	 * XXX: when the temporary address is generated with a new public
1832 	 * address, the onlink check is redundant.  However, it would be safe
1833 	 * to do the check explicitly everywhere a new address is generated,
1834 	 * and, in fact, we surely need the check when we create a new
1835 	 * temporary address due to deprecation of an old temporary address.
1836 	 */
1837 	pfxlist_onlink_check();
1838 
1839 	return(0);
1840 }
1841 
1842 int
1843 in6_init_prefix_ltimes(struct nd_prefix *ndpr)
1844 {
1845 	/* check if preferred lifetime > valid lifetime.  RFC2462 5.5.3 (c) */
1846 	if (ndpr->ndpr_pltime > ndpr->ndpr_vltime) {
1847 		nd6log((LOG_INFO, "in6_init_prefix_ltimes: preferred lifetime"
1848 		    "(%d) is greater than valid lifetime(%d)\n",
1849 		    (u_int)ndpr->ndpr_pltime, (u_int)ndpr->ndpr_vltime));
1850 		return (EINVAL);
1851 	}
1852 	if (ndpr->ndpr_pltime == ND6_INFINITE_LIFETIME)
1853 		ndpr->ndpr_preferred = 0;
1854 	else
1855 		ndpr->ndpr_preferred = time_second + ndpr->ndpr_pltime;
1856 	if (ndpr->ndpr_vltime == ND6_INFINITE_LIFETIME)
1857 		ndpr->ndpr_expire = 0;
1858 	else
1859 		ndpr->ndpr_expire = time_second + ndpr->ndpr_vltime;
1860 
1861 	return 0;
1862 }
1863 
1864 static void
1865 in6_init_address_ltimes(struct nd_prefix *new, struct in6_addrlifetime *lt6)
1866 {
1867 	/* init ia6t_expire */
1868 	if (lt6->ia6t_vltime == ND6_INFINITE_LIFETIME)
1869 		lt6->ia6t_expire = 0;
1870 	else {
1871 		lt6->ia6t_expire = time_second;
1872 		lt6->ia6t_expire += lt6->ia6t_vltime;
1873 	}
1874 
1875 	/* init ia6t_preferred */
1876 	if (lt6->ia6t_pltime == ND6_INFINITE_LIFETIME)
1877 		lt6->ia6t_preferred = 0;
1878 	else {
1879 		lt6->ia6t_preferred = time_second;
1880 		lt6->ia6t_preferred += lt6->ia6t_pltime;
1881 	}
1882 }
1883 
1884 /*
1885  * Delete all the routing table entries that use the specified gateway.
1886  * XXX: this function causes search through all entries of routing table, so
1887  * it shouldn't be called when acting as a router.
1888  */
1889 void
1890 rt6_flush(gateway, ifp)
1891 	struct in6_addr *gateway;
1892 	struct ifnet *ifp;
1893 {
1894 	struct radix_node_head *rnh = rt_tables[AF_INET6];
1895 	int s = splnet();
1896 
1897 	/* We'll care only link-local addresses */
1898 	if (!IN6_IS_ADDR_LINKLOCAL(gateway)) {
1899 		splx(s);
1900 		return;
1901 	}
1902 	/* XXX: hack for KAME's link-local address kludge */
1903 	gateway->s6_addr16[1] = htons(ifp->if_index);
1904 
1905 	RADIX_NODE_HEAD_LOCK(rnh);
1906 	rnh->rnh_walktree(rnh, rt6_deleteroute, (void *)gateway);
1907 	RADIX_NODE_HEAD_UNLOCK(rnh);
1908 	splx(s);
1909 }
1910 
1911 static int
1912 rt6_deleteroute(rn, arg)
1913 	struct radix_node *rn;
1914 	void *arg;
1915 {
1916 #define SIN6(s)	((struct sockaddr_in6 *)s)
1917 	struct rtentry *rt = (struct rtentry *)rn;
1918 	struct in6_addr *gate = (struct in6_addr *)arg;
1919 
1920 	if (rt->rt_gateway == NULL || rt->rt_gateway->sa_family != AF_INET6)
1921 		return(0);
1922 
1923 	if (!IN6_ARE_ADDR_EQUAL(gate, &SIN6(rt->rt_gateway)->sin6_addr))
1924 		return(0);
1925 
1926 	/*
1927 	 * Do not delete a static route.
1928 	 * XXX: this seems to be a bit ad-hoc. Should we consider the
1929 	 * 'cloned' bit instead?
1930 	 */
1931 	if ((rt->rt_flags & RTF_STATIC) != 0)
1932 		return(0);
1933 
1934 	/*
1935 	 * We delete only host route. This means, in particular, we don't
1936 	 * delete default route.
1937 	 */
1938 	if ((rt->rt_flags & RTF_HOST) == 0)
1939 		return(0);
1940 
1941 	return(rtrequest(RTM_DELETE, rt_key(rt),
1942 			 rt->rt_gateway, rt_mask(rt), rt->rt_flags, 0));
1943 #undef SIN6
1944 }
1945 
1946 int
1947 nd6_setdefaultiface(ifindex)
1948 	int ifindex;
1949 {
1950 	int error = 0;
1951 
1952 	if (ifindex < 0 || if_index < ifindex)
1953 		return(EINVAL);
1954 
1955 	if (nd6_defifindex != ifindex) {
1956 		nd6_defifindex = ifindex;
1957 		if (nd6_defifindex > 0)
1958 			nd6_defifp = ifnet_byindex(nd6_defifindex);
1959 		else
1960 			nd6_defifp = NULL;
1961 
1962 		/*
1963 		 * If the Default Router List is empty, install a route
1964 		 * to the specified interface as default or remove the default
1965 		 * route when the default interface becomes canceled.
1966 		 * The check for the queue is actually redundant, but
1967 		 * we do this here to avoid re-install the default route
1968 		 * if the list is NOT empty.
1969 		 */
1970 		if (TAILQ_FIRST(&nd_defrouter) == NULL)
1971 			defrouter_select();
1972 
1973 		/*
1974 		 * Our current implementation assumes one-to-one maping between
1975 		 * interfaces and links, so it would be natural to use the
1976 		 * default interface as the default link.
1977 		 */
1978 		scope6_setdefault(nd6_defifp);
1979 	}
1980 
1981 	return(error);
1982 }
1983