xref: /dragonfly/sys/netinet6/nd6_rtr.c (revision 984263bc)
1 /*	$FreeBSD: src/sys/netinet6/nd6_rtr.c,v 1.2.2.5 2003/04/05 10:28:53 ume Exp $	*/
2 /*	$KAME: nd6_rtr.c,v 1.111 2001/04/27 01:37:15 jinmei Exp $	*/
3 
4 /*
5  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the project nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 #include "opt_inet.h"
34 #include "opt_inet6.h"
35 
36 #include <sys/param.h>
37 #include <sys/systm.h>
38 #include <sys/malloc.h>
39 #include <sys/mbuf.h>
40 #include <sys/socket.h>
41 #include <sys/sockio.h>
42 #include <sys/time.h>
43 #include <sys/kernel.h>
44 #include <sys/errno.h>
45 #include <sys/syslog.h>
46 #include <sys/queue.h>
47 
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 		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 		if (oldrt->rt_refcnt <= 0) {
578 			/*
579 			 * XXX: borrowed from the RTM_DELETE case of
580 			 * rtrequest().
581 			 */
582 			oldrt->rt_refcnt++;
583 			rtfree(oldrt);
584 		}
585 	}
586 
587 	if (dofree)		/* XXX: necessary? */
588 		free(dr, M_IP6NDP);
589 }
590 
591 void
592 defrtrlist_del(dr)
593 	struct nd_defrouter *dr;
594 {
595 	struct nd_defrouter *deldr = NULL;
596 	struct nd_prefix *pr;
597 
598 	/*
599 	 * Flush all the routing table entries that use the router
600 	 * as a next hop.
601 	 */
602 	if (!ip6_forwarding && ip6_accept_rtadv) {
603 		/* above is a good condition? */
604 		rt6_flush(&dr->rtaddr, dr->ifp);
605 	}
606 
607 	if (dr == TAILQ_FIRST(&nd_defrouter))
608 		deldr = dr;	/* The router is primary. */
609 
610 	TAILQ_REMOVE(&nd_defrouter, dr, dr_entry);
611 
612 	/*
613 	 * Also delete all the pointers to the router in each prefix lists.
614 	 */
615 	for (pr = nd_prefix.lh_first; pr; pr = pr->ndpr_next) {
616 		struct nd_pfxrouter *pfxrtr;
617 		if ((pfxrtr = pfxrtr_lookup(pr, dr)) != NULL)
618 			pfxrtr_del(pfxrtr);
619 	}
620 	pfxlist_onlink_check();
621 
622 	/*
623 	 * If the router is the primary one, choose a new one.
624 	 * Note that defrouter_select() will remove the current gateway
625 	 * from the routing table.
626 	 */
627 	if (deldr)
628 		defrouter_select();
629 
630 	free(dr, M_IP6NDP);
631 }
632 
633 /*
634  * Default Router Selection according to Section 6.3.6 of RFC 2461:
635  * 1) Routers that are reachable or probably reachable should be
636  *    preferred.
637  * 2) When no routers on the list are known to be reachable or
638  *    probably reachable, routers SHOULD be selected in a round-robin
639  *    fashion.
640  * 3) If the Default Router List is empty, assume that all
641  *    destinations are on-link.
642  */
643 void
644 defrouter_select()
645 {
646 	int s = splnet();
647 	struct nd_defrouter *dr, anydr;
648 	struct rtentry *rt = NULL;
649 	struct llinfo_nd6 *ln = NULL;
650 
651 	/*
652 	 * Search for a (probably) reachable router from the list.
653 	 */
654 	for (dr = TAILQ_FIRST(&nd_defrouter); dr;
655 	     dr = TAILQ_NEXT(dr, dr_entry)) {
656 		if ((rt = nd6_lookup(&dr->rtaddr, 0, dr->ifp)) &&
657 		    (ln = (struct llinfo_nd6 *)rt->rt_llinfo) &&
658 		    ND6_IS_LLINFO_PROBREACH(ln)) {
659 			/* Got it, and move it to the head */
660 			TAILQ_REMOVE(&nd_defrouter, dr, dr_entry);
661 			TAILQ_INSERT_HEAD(&nd_defrouter, dr, dr_entry);
662 			break;
663 		}
664 	}
665 
666 	if ((dr = TAILQ_FIRST(&nd_defrouter))) {
667 		/*
668 		 * De-install the previous default gateway and install
669 		 * a new one.
670 		 * Note that if there is no reachable router in the list,
671 		 * the head entry will be used anyway.
672 		 * XXX: do we have to check the current routing table entry?
673 		 */
674 		bzero(&anydr, sizeof(anydr));
675 		defrouter_delreq(&anydr, 0);
676 		defrouter_addreq(dr);
677 	}
678 	else {
679 		/*
680 		 * The Default Router List is empty, so install the default
681 		 * route to an inteface.
682 		 * XXX: The specification does not say this mechanism should
683 		 * be restricted to hosts, but this would be not useful
684 		 * (even harmful) for routers.
685 		 */
686 		if (!ip6_forwarding) {
687 			/*
688 			 * De-install the current default route
689 			 * in advance.
690 			 */
691 			bzero(&anydr, sizeof(anydr));
692 			defrouter_delreq(&anydr, 0);
693 			if (nd6_defifp) {
694 				/*
695 				 * Install a route to the default interface
696 				 * as default route.
697 				 * XXX: we enable this for host only, because
698 				 * this may override a default route installed
699 				 * a user process (e.g. routing daemon) in a
700 				 * router case.
701 				 */
702 				defrouter_addifreq(nd6_defifp);
703 			} else {
704 				nd6log((LOG_INFO, "defrouter_select: "
705 				    "there's no default router and no default"
706 				    " interface\n"));
707 			}
708 		}
709 	}
710 
711 	splx(s);
712 	return;
713 }
714 
715 static struct nd_defrouter *
716 defrtrlist_update(new)
717 	struct nd_defrouter *new;
718 {
719 	struct nd_defrouter *dr, *n;
720 	int s = splnet();
721 
722 	if ((dr = defrouter_lookup(&new->rtaddr, new->ifp)) != NULL) {
723 		/* entry exists */
724 		if (new->rtlifetime == 0) {
725 			defrtrlist_del(dr);
726 			dr = NULL;
727 		} else {
728 			/* override */
729 			dr->flags = new->flags; /* xxx flag check */
730 			dr->rtlifetime = new->rtlifetime;
731 			dr->expire = new->expire;
732 		}
733 		splx(s);
734 		return(dr);
735 	}
736 
737 	/* entry does not exist */
738 	if (new->rtlifetime == 0) {
739 		splx(s);
740 		return(NULL);
741 	}
742 
743 	n = (struct nd_defrouter *)malloc(sizeof(*n), M_IP6NDP, M_NOWAIT);
744 	if (n == NULL) {
745 		splx(s);
746 		return(NULL);
747 	}
748 	bzero(n, sizeof(*n));
749 	*n = *new;
750 
751 	/*
752 	 * Insert the new router at the end of the Default Router List.
753 	 * If there is no other router, install it anyway. Otherwise,
754 	 * just continue to use the current default router.
755 	 */
756 	TAILQ_INSERT_TAIL(&nd_defrouter, n, dr_entry);
757 	if (TAILQ_FIRST(&nd_defrouter) == n)
758 		defrouter_select();
759 	splx(s);
760 
761 	return(n);
762 }
763 
764 static struct nd_pfxrouter *
765 pfxrtr_lookup(pr, dr)
766 	struct nd_prefix *pr;
767 	struct nd_defrouter *dr;
768 {
769 	struct nd_pfxrouter *search;
770 
771 	for (search = pr->ndpr_advrtrs.lh_first; search; search = search->pfr_next) {
772 		if (search->router == dr)
773 			break;
774 	}
775 
776 	return(search);
777 }
778 
779 static void
780 pfxrtr_add(pr, dr)
781 	struct nd_prefix *pr;
782 	struct nd_defrouter *dr;
783 {
784 	struct nd_pfxrouter *new;
785 
786 	new = (struct nd_pfxrouter *)malloc(sizeof(*new), M_IP6NDP, M_NOWAIT);
787 	if (new == NULL)
788 		return;
789 	bzero(new, sizeof(*new));
790 	new->router = dr;
791 
792 	LIST_INSERT_HEAD(&pr->ndpr_advrtrs, new, pfr_entry);
793 
794 	pfxlist_onlink_check();
795 }
796 
797 static void
798 pfxrtr_del(pfr)
799 	struct nd_pfxrouter *pfr;
800 {
801 	LIST_REMOVE(pfr, pfr_entry);
802 	free(pfr, M_IP6NDP);
803 }
804 
805 struct nd_prefix *
806 nd6_prefix_lookup(pr)
807 	struct nd_prefix *pr;
808 {
809 	struct nd_prefix *search;
810 
811 	for (search = nd_prefix.lh_first; search; search = search->ndpr_next) {
812 		if (pr->ndpr_ifp == search->ndpr_ifp &&
813 		    pr->ndpr_plen == search->ndpr_plen &&
814 		    in6_are_prefix_equal(&pr->ndpr_prefix.sin6_addr,
815 					 &search->ndpr_prefix.sin6_addr,
816 					 pr->ndpr_plen)
817 		    ) {
818 			break;
819 		}
820 	}
821 
822 	return(search);
823 }
824 
825 int
826 nd6_prelist_add(pr, dr, newp)
827 	struct nd_prefix *pr, **newp;
828 	struct nd_defrouter *dr;
829 {
830 	struct nd_prefix *new = NULL;
831 	int i, s;
832 
833 	new = (struct nd_prefix *)malloc(sizeof(*new), M_IP6NDP, M_NOWAIT);
834 	if (new == NULL)
835 		return ENOMEM;
836 	bzero(new, sizeof(*new));
837 	*new = *pr;
838 	if (newp != NULL)
839 		*newp = new;
840 
841 	/* initilization */
842 	LIST_INIT(&new->ndpr_advrtrs);
843 	in6_prefixlen2mask(&new->ndpr_mask, new->ndpr_plen);
844 	/* make prefix in the canonical form */
845 	for (i = 0; i < 4; i++)
846 		new->ndpr_prefix.sin6_addr.s6_addr32[i] &=
847 			new->ndpr_mask.s6_addr32[i];
848 
849 	s = splnet();
850 	/* link ndpr_entry to nd_prefix list */
851 	LIST_INSERT_HEAD(&nd_prefix, new, ndpr_entry);
852 	splx(s);
853 
854 	/* ND_OPT_PI_FLAG_ONLINK processing */
855 	if (new->ndpr_raf_onlink) {
856 		int e;
857 
858 		if ((e = nd6_prefix_onlink(new)) != 0) {
859 			nd6log((LOG_ERR, "nd6_prelist_add: failed to make "
860 			    "the prefix %s/%d on-link on %s (errno=%d)\n",
861 			    ip6_sprintf(&pr->ndpr_prefix.sin6_addr),
862 			    pr->ndpr_plen, if_name(pr->ndpr_ifp), e));
863 			/* proceed anyway. XXX: is it correct? */
864 		}
865 	}
866 
867 	if (dr) {
868 		pfxrtr_add(new, dr);
869 	}
870 
871 	return 0;
872 }
873 
874 void
875 prelist_remove(pr)
876 	struct nd_prefix *pr;
877 {
878 	struct nd_pfxrouter *pfr, *next;
879 	int e, s;
880 
881 	/* make sure to invalidate the prefix until it is really freed. */
882 	pr->ndpr_vltime = 0;
883 	pr->ndpr_pltime = 0;
884 #if 0
885 	/*
886 	 * Though these flags are now meaningless, we'd rather keep the value
887 	 * not to confuse users when executing "ndp -p".
888 	 */
889 	pr->ndpr_raf_onlink = 0;
890 	pr->ndpr_raf_auto = 0;
891 #endif
892 	if ((pr->ndpr_stateflags & NDPRF_ONLINK) != 0 &&
893 	    (e = nd6_prefix_offlink(pr)) != 0) {
894 		nd6log((LOG_ERR, "prelist_remove: failed to make %s/%d offlink "
895 		    "on %s, errno=%d\n",
896 		    ip6_sprintf(&pr->ndpr_prefix.sin6_addr),
897 		    pr->ndpr_plen, if_name(pr->ndpr_ifp), e));
898 		/* what should we do? */
899 	}
900 
901 	if (pr->ndpr_refcnt > 0)
902 		return;		/* notice here? */
903 
904 	s = splnet();
905 
906 	/* unlink ndpr_entry from nd_prefix list */
907 	LIST_REMOVE(pr, ndpr_entry);
908 
909 	/* free list of routers that adversed the prefix */
910 	for (pfr = pr->ndpr_advrtrs.lh_first; pfr; pfr = next) {
911 		next = pfr->pfr_next;
912 
913 		free(pfr, M_IP6NDP);
914 	}
915 	splx(s);
916 
917 	free(pr, M_IP6NDP);
918 
919 	pfxlist_onlink_check();
920 }
921 
922 int
923 prelist_update(new, dr, m)
924 	struct nd_prefix *new;
925 	struct nd_defrouter *dr; /* may be NULL */
926 	struct mbuf *m;
927 {
928 	struct in6_ifaddr *ia6 = NULL, *ia6_match = NULL;
929 	struct ifaddr *ifa;
930 	struct ifnet *ifp = new->ndpr_ifp;
931 	struct nd_prefix *pr;
932 	int s = splnet();
933 	int error = 0;
934 	int newprefix = 0;
935 	int auth;
936 	struct in6_addrlifetime lt6_tmp;
937 
938 	auth = 0;
939 	if (m) {
940 		/*
941 		 * Authenticity for NA consists authentication for
942 		 * both IP header and IP datagrams, doesn't it ?
943 		 */
944 #if defined(M_AUTHIPHDR) && defined(M_AUTHIPDGM)
945 		auth = (m->m_flags & M_AUTHIPHDR
946 		     && m->m_flags & M_AUTHIPDGM) ? 1 : 0;
947 #endif
948 	}
949 
950 
951 	if ((pr = nd6_prefix_lookup(new)) != NULL) {
952 		/*
953 		 * nd6_prefix_lookup() ensures that pr and new have the same
954 		 * prefix on a same interface.
955 		 */
956 
957 		/*
958 		 * Update prefix information.  Note that the on-link (L) bit
959 		 * and the autonomous (A) bit should NOT be changed from 1
960 		 * to 0.
961 		 */
962 		if (new->ndpr_raf_onlink == 1)
963 			pr->ndpr_raf_onlink = 1;
964 		if (new->ndpr_raf_auto == 1)
965 			pr->ndpr_raf_auto = 1;
966 		if (new->ndpr_raf_onlink) {
967 			pr->ndpr_vltime = new->ndpr_vltime;
968 			pr->ndpr_pltime = new->ndpr_pltime;
969 			pr->ndpr_preferred = new->ndpr_preferred;
970 			pr->ndpr_expire = new->ndpr_expire;
971 		}
972 
973 		if (new->ndpr_raf_onlink &&
974 		    (pr->ndpr_stateflags & NDPRF_ONLINK) == 0) {
975 			int e;
976 
977 			if ((e = nd6_prefix_onlink(pr)) != 0) {
978 				nd6log((LOG_ERR,
979 				    "prelist_update: failed to make "
980 				    "the prefix %s/%d on-link on %s "
981 				    "(errno=%d)\n",
982 				    ip6_sprintf(&pr->ndpr_prefix.sin6_addr),
983 				    pr->ndpr_plen, if_name(pr->ndpr_ifp), e));
984 				/* proceed anyway. XXX: is it correct? */
985 			}
986 		}
987 
988 		if (dr && pfxrtr_lookup(pr, dr) == NULL)
989 			pfxrtr_add(pr, dr);
990 	} else {
991 		struct nd_prefix *newpr = NULL;
992 
993 		newprefix = 1;
994 
995 		if (new->ndpr_vltime == 0)
996 			goto end;
997 		if (new->ndpr_raf_onlink == 0 && new->ndpr_raf_auto == 0)
998 			goto end;
999 
1000 		bzero(&new->ndpr_addr, sizeof(struct in6_addr));
1001 
1002 		error = nd6_prelist_add(new, dr, &newpr);
1003 		if (error != 0 || newpr == NULL) {
1004 			nd6log((LOG_NOTICE, "prelist_update: "
1005 			    "nd6_prelist_add failed for %s/%d on %s "
1006 			    "errno=%d, returnpr=%p\n",
1007 			    ip6_sprintf(&new->ndpr_prefix.sin6_addr),
1008 					new->ndpr_plen, if_name(new->ndpr_ifp),
1009 					error, newpr));
1010 			goto end; /* we should just give up in this case. */
1011 		}
1012 
1013 		/*
1014 		 * XXX: from the ND point of view, we can ignore a prefix
1015 		 * with the on-link bit being zero.  However, we need a
1016 		 * prefix structure for references from autoconfigured
1017 		 * addresses.  Thus, we explicitly make suret that the prefix
1018 		 * itself expires now.
1019 		 */
1020 		if (newpr->ndpr_raf_onlink == 0) {
1021 			newpr->ndpr_vltime = 0;
1022 			newpr->ndpr_pltime = 0;
1023 			in6_init_prefix_ltimes(newpr);
1024 		}
1025 
1026 		pr = newpr;
1027 	}
1028 
1029 	/*
1030 	 * Address autoconfiguration based on Section 5.5.3 of RFC 2462.
1031 	 * Note that pr must be non NULL at this point.
1032 	 */
1033 
1034 	/* 5.5.3 (a). Ignore the prefix without the A bit set. */
1035 	if (!new->ndpr_raf_auto)
1036 		goto afteraddrconf;
1037 
1038 	/*
1039 	 * 5.5.3 (b). the link-local prefix should have been ignored in
1040 	 * nd6_ra_input.
1041 	 */
1042 
1043 	/*
1044 	 * 5.5.3 (c). Consistency check on lifetimes: pltime <= vltime.
1045 	 * This should have been done in nd6_ra_input.
1046 	 */
1047 
1048  	/*
1049 	 * 5.5.3 (d). If the prefix advertised does not match the prefix of an
1050 	 * address already in the list, and the Valid Lifetime is not 0,
1051 	 * form an address.  Note that even a manually configured address
1052 	 * should reject autoconfiguration of a new address.
1053 	 */
1054 	TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list)
1055 	{
1056 		struct in6_ifaddr *ifa6;
1057 		int ifa_plen;
1058 		u_int32_t storedlifetime;
1059 
1060 		if (ifa->ifa_addr->sa_family != AF_INET6)
1061 			continue;
1062 
1063 		ifa6 = (struct in6_ifaddr *)ifa;
1064 
1065 		/*
1066 		 * Spec is not clear here, but I believe we should concentrate
1067 		 * on unicast (i.e. not anycast) addresses.
1068 		 * XXX: other ia6_flags? detached or duplicated?
1069 		 */
1070 		if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0)
1071 			continue;
1072 
1073 		ifa_plen = in6_mask2len(&ifa6->ia_prefixmask.sin6_addr, NULL);
1074 		if (ifa_plen != new->ndpr_plen ||
1075 		    !in6_are_prefix_equal(&ifa6->ia_addr.sin6_addr,
1076 					  &new->ndpr_prefix.sin6_addr,
1077 					  ifa_plen))
1078 			continue;
1079 
1080 		if (ia6_match == NULL) /* remember the first one */
1081 			ia6_match = ifa6;
1082 
1083 		if ((ifa6->ia6_flags & IN6_IFF_AUTOCONF) == 0)
1084 			continue;
1085 
1086 		/*
1087 		 * An already autoconfigured address matched.  Now that we
1088 		 * are sure there is at least one matched address, we can
1089 		 * proceed to 5.5.3. (e): update the lifetimes according to the
1090 		 * "two hours" rule and the privacy extension.
1091 		 */
1092 #define TWOHOUR		(120*60)
1093 		lt6_tmp = ifa6->ia6_lifetime;
1094 
1095 		if (lt6_tmp.ia6t_vltime == ND6_INFINITE_LIFETIME)
1096 			storedlifetime = ND6_INFINITE_LIFETIME;
1097 		else if (IFA6_IS_INVALID(ifa6))
1098 			storedlifetime = 0;
1099 		else
1100 			storedlifetime = lt6_tmp.ia6t_expire - time_second;
1101 
1102 		/* when not updating, keep the current stored lifetime. */
1103 		lt6_tmp.ia6t_vltime = storedlifetime;
1104 
1105 		if (TWOHOUR < new->ndpr_vltime ||
1106 		    storedlifetime < new->ndpr_vltime) {
1107 			lt6_tmp.ia6t_vltime = new->ndpr_vltime;
1108 		} else if (storedlifetime <= TWOHOUR
1109 #if 0
1110 			   /*
1111 			    * This condition is logically redundant, so we just
1112 			    * omit it.
1113 			    * See IPng 6712, 6717, and 6721.
1114 			    */
1115 			   && new->ndpr_vltime <= storedlifetime
1116 #endif
1117 			) {
1118 			if (auth) {
1119 				lt6_tmp.ia6t_vltime = new->ndpr_vltime;
1120 			}
1121 		} else {
1122 			/*
1123 			 * new->ndpr_vltime <= TWOHOUR &&
1124 			 * TWOHOUR < storedlifetime
1125 			 */
1126 			lt6_tmp.ia6t_vltime = TWOHOUR;
1127 		}
1128 
1129 		/* The 2 hour rule is not imposed for preferred lifetime. */
1130 		lt6_tmp.ia6t_pltime = new->ndpr_pltime;
1131 
1132 		in6_init_address_ltimes(pr, &lt6_tmp);
1133 
1134 		/*
1135 		 * When adjusting the lifetimes of an existing temporary
1136 		 * address, only lower the lifetimes.
1137 		 * RFC 3041 3.3. (1).
1138 		 * XXX: how should we modify ia6t_[pv]ltime?
1139 		 */
1140 		if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0) {
1141 			if (lt6_tmp.ia6t_expire == 0 || /* no expire */
1142 			    lt6_tmp.ia6t_expire >
1143 			    ifa6->ia6_lifetime.ia6t_expire) {
1144 				lt6_tmp.ia6t_expire =
1145 					ifa6->ia6_lifetime.ia6t_expire;
1146 			}
1147 			if (lt6_tmp.ia6t_preferred == 0 || /* no expire */
1148 			    lt6_tmp.ia6t_preferred >
1149 			    ifa6->ia6_lifetime.ia6t_preferred) {
1150 				lt6_tmp.ia6t_preferred =
1151 					ifa6->ia6_lifetime.ia6t_preferred;
1152 			}
1153 		}
1154 
1155 		ifa6->ia6_lifetime = lt6_tmp;
1156 	}
1157 	if (ia6_match == NULL && new->ndpr_vltime) {
1158 		/*
1159 		 * No address matched and the valid lifetime is non-zero.
1160 		 * Create a new address.
1161 		 */
1162 		if ((ia6 = in6_ifadd(new, NULL)) != NULL) {
1163 			/*
1164 			 * note that we should use pr (not new) for reference.
1165 			 */
1166 			pr->ndpr_refcnt++;
1167 			ia6->ia6_ndpr = pr;
1168 
1169 #if 0
1170 			/* XXXYYY Don't do this, according to Jinmei. */
1171 			pr->ndpr_addr = new->ndpr_addr;
1172 #endif
1173 
1174 			/*
1175 			 * RFC 3041 3.3 (2).
1176 			 * When a new public address is created as described
1177 			 * in RFC2462, also create a new temporary address.
1178 			 *
1179 			 * RFC 3041 3.5.
1180 			 * When an interface connects to a new link, a new
1181 			 * randomized interface identifier should be generated
1182 			 * immediately together with a new set of temporary
1183 			 * addresses.  Thus, we specifiy 1 as the 2nd arg of
1184 			 * in6_tmpifadd().
1185 			 */
1186 			if (ip6_use_tempaddr) {
1187 				int e;
1188 				if ((e = in6_tmpifadd(ia6, 1)) != 0) {
1189 					nd6log((LOG_NOTICE, "prelist_update: "
1190 					    "failed to create a temporary "
1191 					    "address, errno=%d\n",
1192 					    e));
1193 				}
1194 			}
1195 
1196 			/*
1197 			 * A newly added address might affect the status
1198 			 * of other addresses, so we check and update it.
1199 			 * XXX: what if address duplication happens?
1200 			 */
1201 			pfxlist_onlink_check();
1202 		} else {
1203 			/* just set an error. do not bark here. */
1204 			error = EADDRNOTAVAIL; /* XXX: might be unused. */
1205 		}
1206 	}
1207 
1208   afteraddrconf:
1209 
1210  end:
1211 	splx(s);
1212 	return error;
1213 }
1214 
1215 /*
1216  * A supplement function used in the on-link detection below;
1217  * detect if a given prefix has a (probably) reachable advertising router.
1218  * XXX: lengthy function name...
1219  */
1220 static struct nd_pfxrouter *
1221 find_pfxlist_reachable_router(pr)
1222 	struct nd_prefix *pr;
1223 {
1224 	struct nd_pfxrouter *pfxrtr;
1225 	struct rtentry *rt;
1226 	struct llinfo_nd6 *ln;
1227 
1228 	for (pfxrtr = LIST_FIRST(&pr->ndpr_advrtrs); pfxrtr;
1229 	     pfxrtr = LIST_NEXT(pfxrtr, pfr_entry)) {
1230 		if ((rt = nd6_lookup(&pfxrtr->router->rtaddr, 0,
1231 				     pfxrtr->router->ifp)) &&
1232 		    (ln = (struct llinfo_nd6 *)rt->rt_llinfo) &&
1233 		    ND6_IS_LLINFO_PROBREACH(ln))
1234 			break;	/* found */
1235 	}
1236 
1237 	return(pfxrtr);
1238 
1239 }
1240 
1241 /*
1242  * Check if each prefix in the prefix list has at least one available router
1243  * that advertised the prefix (a router is "available" if its neighbor cache
1244  * entry is reachable or probably reachable).
1245  * If the check fails, the prefix may be off-link, because, for example,
1246  * we have moved from the network but the lifetime of the prefix has not
1247  * expired yet.  So we should not use the prefix if there is another prefix
1248  * that has an available router.
1249  * But, if there is no prefix that has an available router, we still regards
1250  * all the prefixes as on-link.  This is because we can't tell if all the
1251  * routers are simply dead or if we really moved from the network and there
1252  * is no router around us.
1253  */
1254 void
1255 pfxlist_onlink_check()
1256 {
1257 	struct nd_prefix *pr;
1258 	struct in6_ifaddr *ifa;
1259 
1260 	/*
1261 	 * Check if there is a prefix that has a reachable advertising
1262 	 * router.
1263 	 */
1264 	for (pr = nd_prefix.lh_first; pr; pr = pr->ndpr_next) {
1265 		if (pr->ndpr_raf_onlink && find_pfxlist_reachable_router(pr))
1266 			break;
1267 	}
1268 
1269 	if (pr) {
1270 		/*
1271 		 * There is at least one prefix that has a reachable router.
1272 		 * Detach prefixes which have no reachable advertising
1273 		 * router, and attach other prefixes.
1274 		 */
1275 		for (pr = nd_prefix.lh_first; pr; pr = pr->ndpr_next) {
1276 			/* XXX: a link-local prefix should never be detached */
1277 			if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr))
1278 				continue;
1279 
1280 			/*
1281 			 * we aren't interested in prefixes without the L bit
1282 			 * set.
1283 			 */
1284 			if (pr->ndpr_raf_onlink == 0)
1285 				continue;
1286 
1287 			if ((pr->ndpr_stateflags & NDPRF_DETACHED) == 0 &&
1288 			    find_pfxlist_reachable_router(pr) == NULL)
1289 				pr->ndpr_stateflags |= NDPRF_DETACHED;
1290 			if ((pr->ndpr_stateflags & NDPRF_DETACHED) != 0 &&
1291 			    find_pfxlist_reachable_router(pr) != 0)
1292 				pr->ndpr_stateflags &= ~NDPRF_DETACHED;
1293 		}
1294 	} else {
1295 		/* there is no prefix that has a reachable router */
1296 		for (pr = nd_prefix.lh_first; pr; pr = pr->ndpr_next) {
1297 			if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr))
1298 				continue;
1299 
1300 			if (pr->ndpr_raf_onlink == 0)
1301 				continue;
1302 
1303 			if ((pr->ndpr_stateflags & NDPRF_DETACHED) != 0)
1304 				pr->ndpr_stateflags &= ~NDPRF_DETACHED;
1305 		}
1306 	}
1307 
1308 	/*
1309 	 * Remove each interface route associated with a (just) detached
1310 	 * prefix, and reinstall the interface route for a (just) attached
1311 	 * prefix.  Note that all attempt of reinstallation does not
1312 	 * necessarily success, when a same prefix is shared among multiple
1313 	 * interfaces.  Such cases will be handled in nd6_prefix_onlink,
1314 	 * so we don't have to care about them.
1315 	 */
1316 	for (pr = nd_prefix.lh_first; pr; pr = pr->ndpr_next) {
1317 		int e;
1318 
1319 		if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr))
1320 			continue;
1321 
1322 		if (pr->ndpr_raf_onlink == 0)
1323 			continue;
1324 
1325 		if ((pr->ndpr_stateflags & NDPRF_DETACHED) != 0 &&
1326 		    (pr->ndpr_stateflags & NDPRF_ONLINK) != 0) {
1327 			if ((e = nd6_prefix_offlink(pr)) != 0) {
1328 				nd6log((LOG_ERR,
1329 				    "pfxlist_onlink_check: failed to "
1330 				    "make %s/%d offlink, errno=%d\n",
1331 				    ip6_sprintf(&pr->ndpr_prefix.sin6_addr),
1332 				    pr->ndpr_plen, e));
1333 			}
1334 		}
1335 		if ((pr->ndpr_stateflags & NDPRF_DETACHED) == 0 &&
1336 		    (pr->ndpr_stateflags & NDPRF_ONLINK) == 0 &&
1337 		    pr->ndpr_raf_onlink) {
1338 			if ((e = nd6_prefix_onlink(pr)) != 0) {
1339 				nd6log((LOG_ERR,
1340 				    "pfxlist_onlink_check: failed to "
1341 				    "make %s/%d offlink, errno=%d\n",
1342 				    ip6_sprintf(&pr->ndpr_prefix.sin6_addr),
1343 				    pr->ndpr_plen, e));
1344 			}
1345 		}
1346 	}
1347 
1348 	/*
1349 	 * Changes on the prefix status might affect address status as well.
1350 	 * Make sure that all addresses derived from an attached prefix are
1351 	 * attached, and that all addresses derived from a detached prefix are
1352 	 * detached.  Note, however, that a manually configured address should
1353 	 * always be attached.
1354 	 * The precise detection logic is same as the one for prefixes.
1355 	 */
1356 	for (ifa = in6_ifaddr; ifa; ifa = ifa->ia_next) {
1357 		if ((ifa->ia6_flags & IN6_IFF_AUTOCONF) == 0)
1358 			continue;
1359 
1360 		if (ifa->ia6_ndpr == NULL) {
1361 			/*
1362 			 * This can happen when we first configure the address
1363 			 * (i.e. the address exists, but the prefix does not).
1364 			 * XXX: complicated relationships...
1365 			 */
1366 			continue;
1367 		}
1368 
1369 		if (find_pfxlist_reachable_router(ifa->ia6_ndpr))
1370 			break;
1371 	}
1372 	if (ifa) {
1373 		for (ifa = in6_ifaddr; ifa; ifa = ifa->ia_next) {
1374 			if ((ifa->ia6_flags & IN6_IFF_AUTOCONF) == 0)
1375 				continue;
1376 
1377 			if (ifa->ia6_ndpr == NULL) /* XXX: see above. */
1378 				continue;
1379 
1380 			if (find_pfxlist_reachable_router(ifa->ia6_ndpr))
1381 				ifa->ia6_flags &= ~IN6_IFF_DETACHED;
1382 			else
1383 				ifa->ia6_flags |= IN6_IFF_DETACHED;
1384 		}
1385 	}
1386 	else {
1387 		for (ifa = in6_ifaddr; ifa; ifa = ifa->ia_next) {
1388 			if ((ifa->ia6_flags & IN6_IFF_AUTOCONF) == 0)
1389 				continue;
1390 
1391 			ifa->ia6_flags &= ~IN6_IFF_DETACHED;
1392 		}
1393 	}
1394 }
1395 
1396 int
1397 nd6_prefix_onlink(pr)
1398 	struct nd_prefix *pr;
1399 {
1400 	struct ifaddr *ifa;
1401 	struct ifnet *ifp = pr->ndpr_ifp;
1402 	struct sockaddr_in6 mask6;
1403 	struct nd_prefix *opr;
1404 	u_long rtflags;
1405 	int error = 0;
1406 	struct rtentry *rt = NULL;
1407 
1408 	/* sanity check */
1409 	if ((pr->ndpr_stateflags & NDPRF_ONLINK) != 0) {
1410 		nd6log((LOG_ERR,
1411 		    "nd6_prefix_onlink: %s/%d is already on-link\n",
1412 		    ip6_sprintf(&pr->ndpr_prefix.sin6_addr), pr->ndpr_plen);
1413 		return(EEXIST));
1414 	}
1415 
1416 	/*
1417 	 * Add the interface route associated with the prefix.  Before
1418 	 * installing the route, check if there's the same prefix on another
1419 	 * interface, and the prefix has already installed the interface route.
1420 	 * Although such a configuration is expected to be rare, we explicitly
1421 	 * allow it.
1422 	 */
1423 	for (opr = nd_prefix.lh_first; opr; opr = opr->ndpr_next) {
1424 		if (opr == pr)
1425 			continue;
1426 
1427 		if ((opr->ndpr_stateflags & NDPRF_ONLINK) == 0)
1428 			continue;
1429 
1430 		if (opr->ndpr_plen == pr->ndpr_plen &&
1431 		    in6_are_prefix_equal(&pr->ndpr_prefix.sin6_addr,
1432 					 &opr->ndpr_prefix.sin6_addr,
1433 					 pr->ndpr_plen))
1434 			return(0);
1435 	}
1436 
1437 	/*
1438 	 * We prefer link-local addresses as the associated interface address.
1439 	 */
1440 	/* search for a link-local addr */
1441 	ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp,
1442 						      IN6_IFF_NOTREADY|
1443 						      IN6_IFF_ANYCAST);
1444 	if (ifa == NULL) {
1445 		/* XXX: freebsd does not have ifa_ifwithaf */
1446 		TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list)
1447 		{
1448 			if (ifa->ifa_addr->sa_family == AF_INET6)
1449 				break;
1450 		}
1451 		/* should we care about ia6_flags? */
1452 	}
1453 	if (ifa == NULL) {
1454 		/*
1455 		 * This can still happen, when, for example, we receive an RA
1456 		 * containing a prefix with the L bit set and the A bit clear,
1457 		 * after removing all IPv6 addresses on the receiving
1458 		 * interface.  This should, of course, be rare though.
1459 		 */
1460 		nd6log((LOG_NOTICE,
1461 		    "nd6_prefix_onlink: failed to find any ifaddr"
1462 		    " to add route for a prefix(%s/%d) on %s\n",
1463 		    ip6_sprintf(&pr->ndpr_prefix.sin6_addr),
1464 		    pr->ndpr_plen, if_name(ifp)));
1465 		return(0);
1466 	}
1467 
1468 	/*
1469 	 * in6_ifinit() sets nd6_rtrequest to ifa_rtrequest for all ifaddrs.
1470 	 * ifa->ifa_rtrequest = nd6_rtrequest;
1471 	 */
1472 	bzero(&mask6, sizeof(mask6));
1473 	mask6.sin6_len = sizeof(mask6);
1474 	mask6.sin6_addr = pr->ndpr_mask;
1475 	rtflags = ifa->ifa_flags | RTF_CLONING | RTF_UP;
1476 	if (nd6_need_cache(ifp)) {
1477 		/* explicitly set in case ifa_flags does not set the flag. */
1478 		rtflags |= RTF_CLONING;
1479 	} else {
1480 		/*
1481 		 * explicitly clear the cloning bit in case ifa_flags sets it.
1482 		 */
1483 		rtflags &= ~RTF_CLONING;
1484 	}
1485 	error = rtrequest(RTM_ADD, (struct sockaddr *)&pr->ndpr_prefix,
1486 			  ifa->ifa_addr, (struct sockaddr *)&mask6,
1487 			  rtflags, &rt);
1488 	if (error == 0) {
1489 		if (rt != NULL) /* this should be non NULL, though */
1490 			nd6_rtmsg(RTM_ADD, rt);
1491 		pr->ndpr_stateflags |= NDPRF_ONLINK;
1492 	}
1493 	else {
1494 		nd6log((LOG_ERR, "nd6_prefix_onlink: failed to add route for a"
1495 		    " prefix (%s/%d) on %s, gw=%s, mask=%s, flags=%lx "
1496 		    "errno = %d\n",
1497 		    ip6_sprintf(&pr->ndpr_prefix.sin6_addr),
1498 		    pr->ndpr_plen, if_name(ifp),
1499 		    ip6_sprintf(&((struct sockaddr_in6 *)ifa->ifa_addr)->sin6_addr),
1500 		    ip6_sprintf(&mask6.sin6_addr), rtflags, error));
1501 	}
1502 
1503 	if (rt != NULL)
1504 		rt->rt_refcnt--;
1505 
1506 	return(error);
1507 }
1508 
1509 int
1510 nd6_prefix_offlink(pr)
1511 	struct nd_prefix *pr;
1512 {
1513 	int error = 0;
1514 	struct ifnet *ifp = pr->ndpr_ifp;
1515 	struct nd_prefix *opr;
1516 	struct sockaddr_in6 sa6, mask6;
1517 	struct rtentry *rt = NULL;
1518 
1519 	/* sanity check */
1520 	if ((pr->ndpr_stateflags & NDPRF_ONLINK) == 0) {
1521 		nd6log((LOG_ERR,
1522 		    "nd6_prefix_offlink: %s/%d is already off-link\n",
1523 		    ip6_sprintf(&pr->ndpr_prefix.sin6_addr), pr->ndpr_plen));
1524 		return(EEXIST);
1525 	}
1526 
1527 	bzero(&sa6, sizeof(sa6));
1528 	sa6.sin6_family = AF_INET6;
1529 	sa6.sin6_len = sizeof(sa6);
1530 	bcopy(&pr->ndpr_prefix.sin6_addr, &sa6.sin6_addr,
1531 	      sizeof(struct in6_addr));
1532 	bzero(&mask6, sizeof(mask6));
1533 	mask6.sin6_family = AF_INET6;
1534 	mask6.sin6_len = sizeof(sa6);
1535 	bcopy(&pr->ndpr_mask, &mask6.sin6_addr, sizeof(struct in6_addr));
1536 	error = rtrequest(RTM_DELETE, (struct sockaddr *)&sa6, NULL,
1537 			  (struct sockaddr *)&mask6, 0, &rt);
1538 	if (error == 0) {
1539 		pr->ndpr_stateflags &= ~NDPRF_ONLINK;
1540 
1541 		/* report the route deletion to the routing socket. */
1542 		if (rt != NULL)
1543 			nd6_rtmsg(RTM_DELETE, rt);
1544 
1545 		/*
1546 		 * There might be the same prefix on another interface,
1547 		 * the prefix which could not be on-link just because we have
1548 		 * the interface route (see comments in nd6_prefix_onlink).
1549 		 * If there's one, try to make the prefix on-link on the
1550 		 * interface.
1551 		 */
1552 		for (opr = nd_prefix.lh_first; opr; opr = opr->ndpr_next) {
1553 			if (opr == pr)
1554 				continue;
1555 
1556 			if ((opr->ndpr_stateflags & NDPRF_ONLINK) != 0)
1557 				continue;
1558 
1559 			/*
1560 			 * KAME specific: detached prefixes should not be
1561 			 * on-link.
1562 			 */
1563 			if ((opr->ndpr_stateflags & NDPRF_DETACHED) != 0)
1564 				continue;
1565 
1566 			if (opr->ndpr_plen == pr->ndpr_plen &&
1567 			    in6_are_prefix_equal(&pr->ndpr_prefix.sin6_addr,
1568 						 &opr->ndpr_prefix.sin6_addr,
1569 						 pr->ndpr_plen)) {
1570 				int e;
1571 
1572 				if ((e = nd6_prefix_onlink(opr)) != 0) {
1573 					nd6log((LOG_ERR,
1574 					    "nd6_prefix_offlink: failed to "
1575 					    "recover a prefix %s/%d from %s "
1576 					    "to %s (errno = %d)\n",
1577 					    ip6_sprintf(&opr->ndpr_prefix.sin6_addr),
1578 					    opr->ndpr_plen, if_name(ifp),
1579 					    if_name(opr->ndpr_ifp), e));
1580 				}
1581 			}
1582 		}
1583 	}
1584 	else {
1585 		/* XXX: can we still set the NDPRF_ONLINK flag? */
1586 		nd6log((LOG_ERR,
1587 		    "nd6_prefix_offlink: failed to delete route: "
1588 		    "%s/%d on %s (errno = %d)\n",
1589 		    ip6_sprintf(&sa6.sin6_addr), pr->ndpr_plen, if_name(ifp),
1590 		    error));
1591 	}
1592 
1593 	if (rt != NULL) {
1594 		if (rt->rt_refcnt <= 0) {
1595 			/* XXX: we should free the entry ourselves. */
1596 			rt->rt_refcnt++;
1597 			rtfree(rt);
1598 		}
1599 	}
1600 
1601 	return(error);
1602 }
1603 
1604 static struct in6_ifaddr *
1605 in6_ifadd(pr, ifid)
1606 	struct nd_prefix *pr;
1607 	struct in6_addr  *ifid;   /* Mobile IPv6 addition */
1608 {
1609 	struct ifnet *ifp = pr->ndpr_ifp;
1610 	struct ifaddr *ifa;
1611 	struct in6_aliasreq ifra;
1612 	struct in6_ifaddr *ia, *ib;
1613 	int error, plen0;
1614 	struct in6_addr mask;
1615 	int prefixlen = pr->ndpr_plen;
1616 
1617 	in6_len2mask(&mask, prefixlen);
1618 
1619 	/*
1620 	 * find a link-local address (will be interface ID).
1621 	 * Is it really mandatory? Theoretically, a global or a site-local
1622 	 * address can be configured without a link-local address, if we
1623 	 * have a unique interface identifier...
1624 	 *
1625 	 * it is not mandatory to have a link-local address, we can generate
1626 	 * interface identifier on the fly.  we do this because:
1627 	 * (1) it should be the easiest way to find interface identifier.
1628 	 * (2) RFC2462 5.4 suggesting the use of the same interface identifier
1629 	 * for multiple addresses on a single interface, and possible shortcut
1630 	 * of DAD.  we omitted DAD for this reason in the past.
1631 	 * (3) a user can prevent autoconfiguration of global address
1632 	 * by removing link-local address by hand (this is partly because we
1633 	 * don't have other way to control the use of IPv6 on a interface.
1634 	 * this has been our design choice - cf. NRL's "ifconfig auto").
1635 	 * (4) it is easier to manage when an interface has addresses
1636 	 * with the same interface identifier, than to have multiple addresses
1637 	 * with different interface identifiers.
1638 	 *
1639 	 * Mobile IPv6 addition: allow for caller to specify a wished interface
1640 	 * ID. This is to not break connections when moving addresses between
1641 	 * interfaces.
1642 	 */
1643 	ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp, 0);/* 0 is OK? */
1644 	if (ifa)
1645 		ib = (struct in6_ifaddr *)ifa;
1646 	else
1647 		return NULL;
1648 
1649 #if 0 /* don't care link local addr state, and always do DAD */
1650 	/* if link-local address is not eligible, do not autoconfigure. */
1651 	if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_NOTREADY) {
1652 		printf("in6_ifadd: link-local address not ready\n");
1653 		return NULL;
1654 	}
1655 #endif
1656 
1657 	/* prefixlen + ifidlen must be equal to 128 */
1658 	plen0 = in6_mask2len(&ib->ia_prefixmask.sin6_addr, NULL);
1659 	if (prefixlen != plen0) {
1660 		nd6log((LOG_INFO, "in6_ifadd: wrong prefixlen for %s "
1661 		    "(prefix=%d ifid=%d)\n",
1662 		    if_name(ifp), prefixlen, 128 - plen0));
1663 		return NULL;
1664 	}
1665 
1666 	/* make ifaddr */
1667 
1668 	bzero(&ifra, sizeof(ifra));
1669 	/*
1670 	 * in6_update_ifa() does not use ifra_name, but we accurately set it
1671 	 * for safety.
1672 	 */
1673 	strncpy(ifra.ifra_name, if_name(ifp), sizeof(ifra.ifra_name));
1674 	ifra.ifra_addr.sin6_family = AF_INET6;
1675 	ifra.ifra_addr.sin6_len = sizeof(struct sockaddr_in6);
1676 	/* prefix */
1677 	bcopy(&pr->ndpr_prefix.sin6_addr, &ifra.ifra_addr.sin6_addr,
1678 	      sizeof(ifra.ifra_addr.sin6_addr));
1679 	ifra.ifra_addr.sin6_addr.s6_addr32[0] &= mask.s6_addr32[0];
1680 	ifra.ifra_addr.sin6_addr.s6_addr32[1] &= mask.s6_addr32[1];
1681 	ifra.ifra_addr.sin6_addr.s6_addr32[2] &= mask.s6_addr32[2];
1682 	ifra.ifra_addr.sin6_addr.s6_addr32[3] &= mask.s6_addr32[3];
1683 
1684 	/* interface ID */
1685 	if (ifid == NULL || IN6_IS_ADDR_UNSPECIFIED(ifid))
1686 		ifid = &ib->ia_addr.sin6_addr;
1687 	ifra.ifra_addr.sin6_addr.s6_addr32[0]
1688 		|= (ifid->s6_addr32[0] & ~mask.s6_addr32[0]);
1689 	ifra.ifra_addr.sin6_addr.s6_addr32[1]
1690 		|= (ifid->s6_addr32[1] & ~mask.s6_addr32[1]);
1691 	ifra.ifra_addr.sin6_addr.s6_addr32[2]
1692 		|= (ifid->s6_addr32[2] & ~mask.s6_addr32[2]);
1693 	ifra.ifra_addr.sin6_addr.s6_addr32[3]
1694 		|= (ifid->s6_addr32[3] & ~mask.s6_addr32[3]);
1695 
1696 	/* new prefix mask. */
1697 	ifra.ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6);
1698 	ifra.ifra_prefixmask.sin6_family = AF_INET6;
1699 	bcopy(&mask, &ifra.ifra_prefixmask.sin6_addr,
1700 	      sizeof(ifra.ifra_prefixmask.sin6_addr));
1701 
1702 	/*
1703 	 * lifetime.
1704 	 * XXX: in6_init_address_ltimes would override these values later.
1705 	 * We should reconsider this logic.
1706 	 */
1707 	ifra.ifra_lifetime.ia6t_vltime = pr->ndpr_vltime;
1708 	ifra.ifra_lifetime.ia6t_pltime = pr->ndpr_pltime;
1709 
1710 	/* XXX: scope zone ID? */
1711 
1712 	ifra.ifra_flags |= IN6_IFF_AUTOCONF; /* obey autoconf */
1713 	/*
1714 	 * temporarily set the nopfx flag to avoid conflict.
1715 	 * XXX: we should reconsider the entire mechanism about prefix
1716 	 * manipulation.
1717 	 */
1718 	ifra.ifra_flags |= IN6_IFF_NOPFX;
1719 
1720 	/*
1721 	 * keep the new address, regardless of the result of in6_update_ifa.
1722 	 * XXX: this address is now meaningless.
1723 	 * We should reconsider its role.
1724 	 */
1725 	pr->ndpr_addr = ifra.ifra_addr.sin6_addr;
1726 
1727 	/* allocate ifaddr structure, link into chain, etc. */
1728 	if ((error = in6_update_ifa(ifp, &ifra, NULL)) != 0) {
1729 		nd6log((LOG_ERR,
1730 		    "in6_ifadd: failed to make ifaddr %s on %s (errno=%d)\n",
1731 		    ip6_sprintf(&ifra.ifra_addr.sin6_addr), if_name(ifp),
1732 		    error));
1733 		return(NULL);	/* ifaddr must not have been allocated. */
1734 	}
1735 
1736 	ia = in6ifa_ifpwithaddr(ifp, &ifra.ifra_addr.sin6_addr);
1737 
1738 	return(ia);		/* this must NOT be NULL. */
1739 }
1740 
1741 int
1742 in6_tmpifadd(ia0, forcegen)
1743 	const struct in6_ifaddr *ia0; /* corresponding public address */
1744 {
1745 	struct ifnet *ifp = ia0->ia_ifa.ifa_ifp;
1746 	struct in6_ifaddr *newia;
1747 	struct in6_aliasreq ifra;
1748 	int i, error;
1749 	int trylimit = 3;	/* XXX: adhoc value */
1750 	u_int32_t randid[2];
1751 	time_t vltime0, pltime0;
1752 
1753 	bzero(&ifra, sizeof(ifra));
1754 	strncpy(ifra.ifra_name, if_name(ifp), sizeof(ifra.ifra_name));
1755 	ifra.ifra_addr = ia0->ia_addr;
1756 	/* copy prefix mask */
1757 	ifra.ifra_prefixmask = ia0->ia_prefixmask;
1758 	/* clear the old IFID */
1759 	for (i = 0; i < 4; i++) {
1760 		ifra.ifra_addr.sin6_addr.s6_addr32[i]
1761 			&= ifra.ifra_prefixmask.sin6_addr.s6_addr32[i];
1762 	}
1763 
1764   again:
1765 	in6_get_tmpifid(ifp, (u_int8_t *)randid,
1766 			(const u_int8_t *)&ia0->ia_addr.sin6_addr.s6_addr[8],
1767 			forcegen);
1768 	ifra.ifra_addr.sin6_addr.s6_addr32[2]
1769 		|= (randid[0] & ~(ifra.ifra_prefixmask.sin6_addr.s6_addr32[2]));
1770 	ifra.ifra_addr.sin6_addr.s6_addr32[3]
1771 		|= (randid[1] & ~(ifra.ifra_prefixmask.sin6_addr.s6_addr32[3]));
1772 
1773 	/*
1774 	 * If by chance the new temporary address is the same as an address
1775 	 * already assigned to the interface, generate a new randomized
1776 	 * interface identifier and repeat this step.
1777 	 * RFC 3041 3.3 (4).
1778 	 */
1779 	if (in6ifa_ifpwithaddr(ifp, &ifra.ifra_addr.sin6_addr) != NULL) {
1780 		if (trylimit-- == 0) {
1781 			nd6log((LOG_NOTICE, "in6_tmpifadd: failed to find "
1782 			    "a unique random IFID\n"));
1783 			return(EEXIST);
1784 		}
1785 		forcegen = 1;
1786 		goto again;
1787 	}
1788 
1789 	/*
1790 	 * The Valid Lifetime is the lower of the Valid Lifetime of the
1791          * public address or TEMP_VALID_LIFETIME.
1792 	 * The Preferred Lifetime is the lower of the Preferred Lifetime
1793          * of the public address or TEMP_PREFERRED_LIFETIME -
1794          * DESYNC_FACTOR.
1795 	 */
1796 	if (ia0->ia6_lifetime.ia6t_expire != 0) {
1797 		vltime0 = IFA6_IS_INVALID(ia0) ? 0 :
1798 			(ia0->ia6_lifetime.ia6t_expire - time_second);
1799 		if (vltime0 > ip6_temp_valid_lifetime)
1800 			vltime0 = ip6_temp_valid_lifetime;
1801 	} else
1802 		vltime0 = ip6_temp_valid_lifetime;
1803 	if (ia0->ia6_lifetime.ia6t_preferred != 0) {
1804 		pltime0 = IFA6_IS_DEPRECATED(ia0) ? 0 :
1805 			(ia0->ia6_lifetime.ia6t_preferred - time_second);
1806 		if (pltime0 > ip6_temp_preferred_lifetime - ip6_desync_factor){
1807 			pltime0 = ip6_temp_preferred_lifetime -
1808 				ip6_desync_factor;
1809 		}
1810 	} else
1811 		pltime0 = ip6_temp_preferred_lifetime - ip6_desync_factor;
1812 	ifra.ifra_lifetime.ia6t_vltime = vltime0;
1813 	ifra.ifra_lifetime.ia6t_pltime = pltime0;
1814 
1815 	/*
1816 	 * A temporary address is created only if this calculated Preferred
1817 	 * Lifetime is greater than REGEN_ADVANCE time units.
1818 	 */
1819 	if (ifra.ifra_lifetime.ia6t_pltime <= ip6_temp_regen_advance)
1820 		return(0);
1821 
1822 	/* XXX: scope zone ID? */
1823 
1824 	ifra.ifra_flags |= (IN6_IFF_AUTOCONF|IN6_IFF_TEMPORARY);
1825 
1826 	/* allocate ifaddr structure, link into chain, etc. */
1827 	if ((error = in6_update_ifa(ifp, &ifra, NULL)) != 0)
1828 		return(error);
1829 
1830 	newia = in6ifa_ifpwithaddr(ifp, &ifra.ifra_addr.sin6_addr);
1831 	if (newia == NULL) {	/* XXX: can it happen? */
1832 		nd6log((LOG_ERR,
1833 		    "in6_tmpifadd: ifa update succeeded, but we got "
1834 		    "no ifaddr\n"));
1835 		return(EINVAL); /* XXX */
1836 	}
1837 	newia->ia6_ndpr = ia0->ia6_ndpr;
1838 	newia->ia6_ndpr->ndpr_refcnt++;
1839 
1840 	return(0);
1841 }
1842 
1843 int
1844 in6_init_prefix_ltimes(struct nd_prefix *ndpr)
1845 {
1846 	/* check if preferred lifetime > valid lifetime.  RFC2462 5.5.3 (c) */
1847 	if (ndpr->ndpr_pltime > ndpr->ndpr_vltime) {
1848 		nd6log((LOG_INFO, "in6_init_prefix_ltimes: preferred lifetime"
1849 		    "(%d) is greater than valid lifetime(%d)\n",
1850 		    (u_int)ndpr->ndpr_pltime, (u_int)ndpr->ndpr_vltime));
1851 		return (EINVAL);
1852 	}
1853 	if (ndpr->ndpr_pltime == ND6_INFINITE_LIFETIME)
1854 		ndpr->ndpr_preferred = 0;
1855 	else
1856 		ndpr->ndpr_preferred = time_second + ndpr->ndpr_pltime;
1857 	if (ndpr->ndpr_vltime == ND6_INFINITE_LIFETIME)
1858 		ndpr->ndpr_expire = 0;
1859 	else
1860 		ndpr->ndpr_expire = time_second + ndpr->ndpr_vltime;
1861 
1862 	return 0;
1863 }
1864 
1865 static void
1866 in6_init_address_ltimes(struct nd_prefix *new, struct in6_addrlifetime *lt6)
1867 {
1868 	/* init ia6t_expire */
1869 	if (lt6->ia6t_vltime == ND6_INFINITE_LIFETIME)
1870 		lt6->ia6t_expire = 0;
1871 	else {
1872 		lt6->ia6t_expire = time_second;
1873 		lt6->ia6t_expire += lt6->ia6t_vltime;
1874 	}
1875 
1876 	/* init ia6t_preferred */
1877 	if (lt6->ia6t_pltime == ND6_INFINITE_LIFETIME)
1878 		lt6->ia6t_preferred = 0;
1879 	else {
1880 		lt6->ia6t_preferred = time_second;
1881 		lt6->ia6t_preferred += lt6->ia6t_pltime;
1882 	}
1883 }
1884 
1885 /*
1886  * Delete all the routing table entries that use the specified gateway.
1887  * XXX: this function causes search through all entries of routing table, so
1888  * it shouldn't be called when acting as a router.
1889  */
1890 void
1891 rt6_flush(gateway, ifp)
1892 	struct in6_addr *gateway;
1893 	struct ifnet *ifp;
1894 {
1895 	struct radix_node_head *rnh = rt_tables[AF_INET6];
1896 	int s = splnet();
1897 
1898 	/* We'll care only link-local addresses */
1899 	if (!IN6_IS_ADDR_LINKLOCAL(gateway)) {
1900 		splx(s);
1901 		return;
1902 	}
1903 	/* XXX: hack for KAME's link-local address kludge */
1904 	gateway->s6_addr16[1] = htons(ifp->if_index);
1905 
1906 	rnh->rnh_walktree(rnh, rt6_deleteroute, (void *)gateway);
1907 	splx(s);
1908 }
1909 
1910 static int
1911 rt6_deleteroute(rn, arg)
1912 	struct radix_node *rn;
1913 	void *arg;
1914 {
1915 #define SIN6(s)	((struct sockaddr_in6 *)s)
1916 	struct rtentry *rt = (struct rtentry *)rn;
1917 	struct in6_addr *gate = (struct in6_addr *)arg;
1918 
1919 	if (rt->rt_gateway == NULL || rt->rt_gateway->sa_family != AF_INET6)
1920 		return(0);
1921 
1922 	if (!IN6_ARE_ADDR_EQUAL(gate, &SIN6(rt->rt_gateway)->sin6_addr))
1923 		return(0);
1924 
1925 	/*
1926 	 * Do not delete a static route.
1927 	 * XXX: this seems to be a bit ad-hoc. Should we consider the
1928 	 * 'cloned' bit instead?
1929 	 */
1930 	if ((rt->rt_flags & RTF_STATIC) != 0)
1931 		return(0);
1932 
1933 	/*
1934 	 * We delete only host route. This means, in particular, we don't
1935 	 * delete default route.
1936 	 */
1937 	if ((rt->rt_flags & RTF_HOST) == 0)
1938 		return(0);
1939 
1940 	return(rtrequest(RTM_DELETE, rt_key(rt),
1941 			 rt->rt_gateway, rt_mask(rt), rt->rt_flags, 0));
1942 #undef SIN6
1943 }
1944 
1945 int
1946 nd6_setdefaultiface(ifindex)
1947 	int ifindex;
1948 {
1949 	int error = 0;
1950 
1951 	if (ifindex < 0 || if_index < ifindex)
1952 		return(EINVAL);
1953 
1954 	if (nd6_defifindex != ifindex) {
1955 		nd6_defifindex = ifindex;
1956 		if (nd6_defifindex > 0)
1957 			nd6_defifp = ifindex2ifnet[nd6_defifindex];
1958 		else
1959 			nd6_defifp = NULL;
1960 
1961 		/*
1962 		 * If the Default Router List is empty, install a route
1963 		 * to the specified interface as default or remove the default
1964 		 * route when the default interface becomes canceled.
1965 		 * The check for the queue is actually redundant, but
1966 		 * we do this here to avoid re-install the default route
1967 		 * if the list is NOT empty.
1968 		 */
1969 		if (TAILQ_FIRST(&nd_defrouter) == NULL)
1970 			defrouter_select();
1971 
1972 		/*
1973 		 * Our current implementation assumes one-to-one maping between
1974 		 * interfaces and links, so it would be natural to use the
1975 		 * default interface as the default link.
1976 		 */
1977 		scope6_setdefault(nd6_defifp);
1978 	}
1979 
1980 	return(error);
1981 }
1982