xref: /freebsd/sys/netinet6/nd6_rtr.c (revision 4f52dfbb8d6c4d446500c5b097e3806ec219fbd4)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the project nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  *
31  *	$KAME: nd6_rtr.c,v 1.111 2001/04/27 01:37:15 jinmei Exp $
32  */
33 
34 #include <sys/cdefs.h>
35 __FBSDID("$FreeBSD$");
36 
37 #include "opt_inet.h"
38 #include "opt_inet6.h"
39 
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/malloc.h>
43 #include <sys/mbuf.h>
44 #include <sys/refcount.h>
45 #include <sys/socket.h>
46 #include <sys/sockio.h>
47 #include <sys/time.h>
48 #include <sys/kernel.h>
49 #include <sys/lock.h>
50 #include <sys/errno.h>
51 #include <sys/rmlock.h>
52 #include <sys/rwlock.h>
53 #include <sys/syslog.h>
54 #include <sys/queue.h>
55 
56 #include <net/if.h>
57 #include <net/if_var.h>
58 #include <net/if_types.h>
59 #include <net/if_dl.h>
60 #include <net/route.h>
61 #include <net/route_var.h>
62 #include <net/radix.h>
63 #include <net/vnet.h>
64 
65 #include <netinet/in.h>
66 #include <net/if_llatbl.h>
67 #include <netinet6/in6_var.h>
68 #include <netinet6/in6_ifattach.h>
69 #include <netinet/ip6.h>
70 #include <netinet6/ip6_var.h>
71 #include <netinet6/nd6.h>
72 #include <netinet/icmp6.h>
73 #include <netinet6/scope6_var.h>
74 
75 static int rtpref(struct nd_defrouter *);
76 static struct nd_defrouter *defrtrlist_update(struct nd_defrouter *);
77 static int prelist_update(struct nd_prefixctl *, struct nd_defrouter *,
78     struct mbuf *, int);
79 static struct in6_ifaddr *in6_ifadd(struct nd_prefixctl *, int);
80 static struct nd_pfxrouter *pfxrtr_lookup(struct nd_prefix *,
81     struct nd_defrouter *);
82 static void pfxrtr_add(struct nd_prefix *, struct nd_defrouter *);
83 static void pfxrtr_del(struct nd_pfxrouter *);
84 static struct nd_pfxrouter *find_pfxlist_reachable_router(struct nd_prefix *);
85 static void defrouter_delreq(struct nd_defrouter *);
86 static void nd6_rtmsg(int, struct rtentry *);
87 
88 static int in6_init_prefix_ltimes(struct nd_prefix *);
89 static void in6_init_address_ltimes(struct nd_prefix *,
90     struct in6_addrlifetime *);
91 
92 static int rt6_deleteroute(const struct rtentry *, void *);
93 
94 VNET_DECLARE(int, nd6_recalc_reachtm_interval);
95 #define	V_nd6_recalc_reachtm_interval	VNET(nd6_recalc_reachtm_interval)
96 
97 static VNET_DEFINE(struct ifnet *, nd6_defifp);
98 VNET_DEFINE(int, nd6_defifindex);
99 #define	V_nd6_defifp			VNET(nd6_defifp)
100 
101 VNET_DEFINE(int, ip6_use_tempaddr) = 0;
102 
103 VNET_DEFINE(int, ip6_desync_factor);
104 VNET_DEFINE(u_int32_t, ip6_temp_preferred_lifetime) = DEF_TEMP_PREFERRED_LIFETIME;
105 VNET_DEFINE(u_int32_t, ip6_temp_valid_lifetime) = DEF_TEMP_VALID_LIFETIME;
106 
107 VNET_DEFINE(int, ip6_temp_regen_advance) = TEMPADDR_REGEN_ADVANCE;
108 
109 /* RTPREF_MEDIUM has to be 0! */
110 #define RTPREF_HIGH	1
111 #define RTPREF_MEDIUM	0
112 #define RTPREF_LOW	(-1)
113 #define RTPREF_RESERVED	(-2)
114 #define RTPREF_INVALID	(-3)	/* internal */
115 
116 /*
117  * Receive Router Solicitation Message - just for routers.
118  * Router solicitation/advertisement is mostly managed by userland program
119  * (rtadvd) so here we have no function like nd6_ra_output().
120  *
121  * Based on RFC 2461
122  */
123 void
124 nd6_rs_input(struct mbuf *m, int off, int icmp6len)
125 {
126 	struct ifnet *ifp = m->m_pkthdr.rcvif;
127 	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
128 	struct nd_router_solicit *nd_rs;
129 	struct in6_addr saddr6 = ip6->ip6_src;
130 	char *lladdr = NULL;
131 	int lladdrlen = 0;
132 	union nd_opts ndopts;
133 	char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
134 
135 	/*
136 	 * Accept RS only when V_ip6_forwarding=1 and the interface has
137 	 * no ND6_IFF_ACCEPT_RTADV.
138 	 */
139 	if (!V_ip6_forwarding || ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV)
140 		goto freeit;
141 
142 	/* RFC 6980: Nodes MUST silently ignore fragments */
143 	if(m->m_flags & M_FRAGMENTED)
144 		goto freeit;
145 
146 	/* Sanity checks */
147 	if (ip6->ip6_hlim != 255) {
148 		nd6log((LOG_ERR,
149 		    "nd6_rs_input: invalid hlim (%d) from %s to %s on %s\n",
150 		    ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src),
151 		    ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp)));
152 		goto bad;
153 	}
154 
155 	/*
156 	 * Don't update the neighbor cache, if src = ::.
157 	 * This indicates that the src has no IP address assigned yet.
158 	 */
159 	if (IN6_IS_ADDR_UNSPECIFIED(&saddr6))
160 		goto freeit;
161 
162 #ifndef PULLDOWN_TEST
163 	IP6_EXTHDR_CHECK(m, off, icmp6len,);
164 	nd_rs = (struct nd_router_solicit *)((caddr_t)ip6 + off);
165 #else
166 	IP6_EXTHDR_GET(nd_rs, struct nd_router_solicit *, m, off, icmp6len);
167 	if (nd_rs == NULL) {
168 		ICMP6STAT_INC(icp6s_tooshort);
169 		return;
170 	}
171 #endif
172 
173 	icmp6len -= sizeof(*nd_rs);
174 	nd6_option_init(nd_rs + 1, icmp6len, &ndopts);
175 	if (nd6_options(&ndopts) < 0) {
176 		nd6log((LOG_INFO,
177 		    "nd6_rs_input: invalid ND option, ignored\n"));
178 		/* nd6_options have incremented stats */
179 		goto freeit;
180 	}
181 
182 	if (ndopts.nd_opts_src_lladdr) {
183 		lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1);
184 		lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3;
185 	}
186 
187 	if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
188 		nd6log((LOG_INFO,
189 		    "nd6_rs_input: lladdrlen mismatch for %s "
190 		    "(if %d, RS packet %d)\n",
191 		    ip6_sprintf(ip6bufs, &saddr6),
192 		    ifp->if_addrlen, lladdrlen - 2));
193 		goto bad;
194 	}
195 
196 	nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, ND_ROUTER_SOLICIT, 0);
197 
198  freeit:
199 	m_freem(m);
200 	return;
201 
202  bad:
203 	ICMP6STAT_INC(icp6s_badrs);
204 	m_freem(m);
205 }
206 
207 /*
208  * Receive Router Advertisement Message.
209  *
210  * Based on RFC 2461
211  * TODO: on-link bit on prefix information
212  * TODO: ND_RA_FLAG_{OTHER,MANAGED} processing
213  */
214 void
215 nd6_ra_input(struct mbuf *m, int off, int icmp6len)
216 {
217 	struct ifnet *ifp = m->m_pkthdr.rcvif;
218 	struct nd_ifinfo *ndi = ND_IFINFO(ifp);
219 	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
220 	struct nd_router_advert *nd_ra;
221 	struct in6_addr saddr6 = ip6->ip6_src;
222 	int mcast = 0;
223 	union nd_opts ndopts;
224 	struct nd_defrouter *dr;
225 	char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
226 
227 	dr = NULL;
228 
229 	/*
230 	 * We only accept RAs only when the per-interface flag
231 	 * ND6_IFF_ACCEPT_RTADV is on the receiving interface.
232 	 */
233 	if (!(ndi->flags & ND6_IFF_ACCEPT_RTADV))
234 		goto freeit;
235 
236 	/* RFC 6980: Nodes MUST silently ignore fragments */
237 	if(m->m_flags & M_FRAGMENTED)
238 		goto freeit;
239 
240 	if (ip6->ip6_hlim != 255) {
241 		nd6log((LOG_ERR,
242 		    "nd6_ra_input: invalid hlim (%d) from %s to %s on %s\n",
243 		    ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src),
244 		    ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp)));
245 		goto bad;
246 	}
247 
248 	if (!IN6_IS_ADDR_LINKLOCAL(&saddr6)) {
249 		nd6log((LOG_ERR,
250 		    "nd6_ra_input: src %s is not link-local\n",
251 		    ip6_sprintf(ip6bufs, &saddr6)));
252 		goto bad;
253 	}
254 
255 #ifndef PULLDOWN_TEST
256 	IP6_EXTHDR_CHECK(m, off, icmp6len,);
257 	nd_ra = (struct nd_router_advert *)((caddr_t)ip6 + off);
258 #else
259 	IP6_EXTHDR_GET(nd_ra, struct nd_router_advert *, m, off, icmp6len);
260 	if (nd_ra == NULL) {
261 		ICMP6STAT_INC(icp6s_tooshort);
262 		return;
263 	}
264 #endif
265 
266 	icmp6len -= sizeof(*nd_ra);
267 	nd6_option_init(nd_ra + 1, icmp6len, &ndopts);
268 	if (nd6_options(&ndopts) < 0) {
269 		nd6log((LOG_INFO,
270 		    "nd6_ra_input: invalid ND option, ignored\n"));
271 		/* nd6_options have incremented stats */
272 		goto freeit;
273 	}
274 
275     {
276 	struct nd_defrouter dr0;
277 	u_int32_t advreachable = nd_ra->nd_ra_reachable;
278 
279 	/* remember if this is a multicasted advertisement */
280 	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst))
281 		mcast = 1;
282 
283 	bzero(&dr0, sizeof(dr0));
284 	dr0.rtaddr = saddr6;
285 	dr0.raflags = nd_ra->nd_ra_flags_reserved;
286 	/*
287 	 * Effectively-disable routes from RA messages when
288 	 * ND6_IFF_NO_RADR enabled on the receiving interface or
289 	 * (ip6.forwarding == 1 && ip6.rfc6204w3 != 1).
290 	 */
291 	if (ndi->flags & ND6_IFF_NO_RADR)
292 		dr0.rtlifetime = 0;
293 	else if (V_ip6_forwarding && !V_ip6_rfc6204w3)
294 		dr0.rtlifetime = 0;
295 	else
296 		dr0.rtlifetime = ntohs(nd_ra->nd_ra_router_lifetime);
297 	dr0.expire = time_uptime + dr0.rtlifetime;
298 	dr0.ifp = ifp;
299 	/* unspecified or not? (RFC 2461 6.3.4) */
300 	if (advreachable) {
301 		advreachable = ntohl(advreachable);
302 		if (advreachable <= MAX_REACHABLE_TIME &&
303 		    ndi->basereachable != advreachable) {
304 			ndi->basereachable = advreachable;
305 			ndi->reachable = ND_COMPUTE_RTIME(ndi->basereachable);
306 			ndi->recalctm = V_nd6_recalc_reachtm_interval; /* reset */
307 		}
308 	}
309 	if (nd_ra->nd_ra_retransmit)
310 		ndi->retrans = ntohl(nd_ra->nd_ra_retransmit);
311 	if (nd_ra->nd_ra_curhoplimit) {
312 		if (ndi->chlim < nd_ra->nd_ra_curhoplimit)
313 			ndi->chlim = nd_ra->nd_ra_curhoplimit;
314 		else if (ndi->chlim != nd_ra->nd_ra_curhoplimit) {
315 			log(LOG_ERR, "RA with a lower CurHopLimit sent from "
316 			    "%s on %s (current = %d, received = %d). "
317 			    "Ignored.\n", ip6_sprintf(ip6bufs, &ip6->ip6_src),
318 			    if_name(ifp), ndi->chlim, nd_ra->nd_ra_curhoplimit);
319 		}
320 	}
321 	dr = defrtrlist_update(&dr0);
322     }
323 
324 	/*
325 	 * prefix
326 	 */
327 	if (ndopts.nd_opts_pi) {
328 		struct nd_opt_hdr *pt;
329 		struct nd_opt_prefix_info *pi = NULL;
330 		struct nd_prefixctl pr;
331 
332 		for (pt = (struct nd_opt_hdr *)ndopts.nd_opts_pi;
333 		     pt <= (struct nd_opt_hdr *)ndopts.nd_opts_pi_end;
334 		     pt = (struct nd_opt_hdr *)((caddr_t)pt +
335 						(pt->nd_opt_len << 3))) {
336 			if (pt->nd_opt_type != ND_OPT_PREFIX_INFORMATION)
337 				continue;
338 			pi = (struct nd_opt_prefix_info *)pt;
339 
340 			if (pi->nd_opt_pi_len != 4) {
341 				nd6log((LOG_INFO,
342 				    "nd6_ra_input: invalid option "
343 				    "len %d for prefix information option, "
344 				    "ignored\n", pi->nd_opt_pi_len));
345 				continue;
346 			}
347 
348 			if (128 < pi->nd_opt_pi_prefix_len) {
349 				nd6log((LOG_INFO,
350 				    "nd6_ra_input: invalid prefix "
351 				    "len %d for prefix information option, "
352 				    "ignored\n", pi->nd_opt_pi_prefix_len));
353 				continue;
354 			}
355 
356 			if (IN6_IS_ADDR_MULTICAST(&pi->nd_opt_pi_prefix)
357 			 || IN6_IS_ADDR_LINKLOCAL(&pi->nd_opt_pi_prefix)) {
358 				nd6log((LOG_INFO,
359 				    "nd6_ra_input: invalid prefix "
360 				    "%s, ignored\n",
361 				    ip6_sprintf(ip6bufs,
362 					&pi->nd_opt_pi_prefix)));
363 				continue;
364 			}
365 
366 			bzero(&pr, sizeof(pr));
367 			pr.ndpr_prefix.sin6_family = AF_INET6;
368 			pr.ndpr_prefix.sin6_len = sizeof(pr.ndpr_prefix);
369 			pr.ndpr_prefix.sin6_addr = pi->nd_opt_pi_prefix;
370 			pr.ndpr_ifp = (struct ifnet *)m->m_pkthdr.rcvif;
371 
372 			pr.ndpr_raf_onlink = (pi->nd_opt_pi_flags_reserved &
373 			    ND_OPT_PI_FLAG_ONLINK) ? 1 : 0;
374 			pr.ndpr_raf_auto = (pi->nd_opt_pi_flags_reserved &
375 			    ND_OPT_PI_FLAG_AUTO) ? 1 : 0;
376 			pr.ndpr_plen = pi->nd_opt_pi_prefix_len;
377 			pr.ndpr_vltime = ntohl(pi->nd_opt_pi_valid_time);
378 			pr.ndpr_pltime = ntohl(pi->nd_opt_pi_preferred_time);
379 			(void)prelist_update(&pr, dr, m, mcast);
380 		}
381 	}
382 	if (dr != NULL) {
383 		defrouter_rele(dr);
384 		dr = NULL;
385 	}
386 
387 	/*
388 	 * MTU
389 	 */
390 	if (ndopts.nd_opts_mtu && ndopts.nd_opts_mtu->nd_opt_mtu_len == 1) {
391 		u_long mtu;
392 		u_long maxmtu;
393 
394 		mtu = (u_long)ntohl(ndopts.nd_opts_mtu->nd_opt_mtu_mtu);
395 
396 		/* lower bound */
397 		if (mtu < IPV6_MMTU) {
398 			nd6log((LOG_INFO, "nd6_ra_input: bogus mtu option "
399 			    "mtu=%lu sent from %s, ignoring\n",
400 			    mtu, ip6_sprintf(ip6bufs, &ip6->ip6_src)));
401 			goto skip;
402 		}
403 
404 		/* upper bound */
405 		maxmtu = (ndi->maxmtu && ndi->maxmtu < ifp->if_mtu)
406 		    ? ndi->maxmtu : ifp->if_mtu;
407 		if (mtu <= maxmtu) {
408 			int change = (ndi->linkmtu != mtu);
409 
410 			ndi->linkmtu = mtu;
411 			if (change) {
412 				/* in6_maxmtu may change */
413 				in6_setmaxmtu();
414 				rt_updatemtu(ifp);
415 			}
416 		} else {
417 			nd6log((LOG_INFO, "nd6_ra_input: bogus mtu "
418 			    "mtu=%lu sent from %s; "
419 			    "exceeds maxmtu %lu, ignoring\n",
420 			    mtu, ip6_sprintf(ip6bufs, &ip6->ip6_src), maxmtu));
421 		}
422 	}
423 
424  skip:
425 
426 	/*
427 	 * Source link layer address
428 	 */
429     {
430 	char *lladdr = NULL;
431 	int lladdrlen = 0;
432 
433 	if (ndopts.nd_opts_src_lladdr) {
434 		lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1);
435 		lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3;
436 	}
437 
438 	if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
439 		nd6log((LOG_INFO,
440 		    "nd6_ra_input: lladdrlen mismatch for %s "
441 		    "(if %d, RA packet %d)\n", ip6_sprintf(ip6bufs, &saddr6),
442 		    ifp->if_addrlen, lladdrlen - 2));
443 		goto bad;
444 	}
445 
446 	nd6_cache_lladdr(ifp, &saddr6, lladdr,
447 	    lladdrlen, ND_ROUTER_ADVERT, 0);
448 
449 	/*
450 	 * Installing a link-layer address might change the state of the
451 	 * router's neighbor cache, which might also affect our on-link
452 	 * detection of adveritsed prefixes.
453 	 */
454 	pfxlist_onlink_check();
455     }
456 
457  freeit:
458 	m_freem(m);
459 	return;
460 
461  bad:
462 	ICMP6STAT_INC(icp6s_badra);
463 	m_freem(m);
464 }
465 
466 /* tell the change to user processes watching the routing socket. */
467 static void
468 nd6_rtmsg(int cmd, struct rtentry *rt)
469 {
470 	struct rt_addrinfo info;
471 	struct ifnet *ifp;
472 	struct ifaddr *ifa;
473 
474 	bzero((caddr_t)&info, sizeof(info));
475 	info.rti_info[RTAX_DST] = rt_key(rt);
476 	info.rti_info[RTAX_GATEWAY] = rt->rt_gateway;
477 	info.rti_info[RTAX_NETMASK] = rt_mask(rt);
478 	ifp = rt->rt_ifp;
479 	if (ifp != NULL) {
480 		IF_ADDR_RLOCK(ifp);
481 		ifa = TAILQ_FIRST(&ifp->if_addrhead);
482 		info.rti_info[RTAX_IFP] = ifa->ifa_addr;
483 		ifa_ref(ifa);
484 		IF_ADDR_RUNLOCK(ifp);
485 		info.rti_info[RTAX_IFA] = rt->rt_ifa->ifa_addr;
486 	} else
487 		ifa = NULL;
488 
489 	rt_missmsg_fib(cmd, &info, rt->rt_flags, 0, rt->rt_fibnum);
490 	if (ifa != NULL)
491 		ifa_free(ifa);
492 }
493 
494 /*
495  * default router list processing sub routines
496  */
497 
498 static void
499 defrouter_addreq(struct nd_defrouter *new)
500 {
501 	struct sockaddr_in6 def, mask, gate;
502 	struct rtentry *newrt = NULL;
503 	int error;
504 
505 	bzero(&def, sizeof(def));
506 	bzero(&mask, sizeof(mask));
507 	bzero(&gate, sizeof(gate));
508 
509 	def.sin6_len = mask.sin6_len = gate.sin6_len =
510 	    sizeof(struct sockaddr_in6);
511 	def.sin6_family = gate.sin6_family = AF_INET6;
512 	gate.sin6_addr = new->rtaddr;
513 
514 	error = in6_rtrequest(RTM_ADD, (struct sockaddr *)&def,
515 	    (struct sockaddr *)&gate, (struct sockaddr *)&mask,
516 	    RTF_GATEWAY, &newrt, new->ifp->if_fib);
517 	if (newrt) {
518 		nd6_rtmsg(RTM_ADD, newrt); /* tell user process */
519 		RTFREE(newrt);
520 	}
521 	if (error == 0)
522 		new->installed = 1;
523 }
524 
525 struct nd_defrouter *
526 defrouter_lookup_locked(struct in6_addr *addr, struct ifnet *ifp)
527 {
528 	struct nd_defrouter *dr;
529 
530 	ND6_LOCK_ASSERT();
531 	TAILQ_FOREACH(dr, &V_nd_defrouter, dr_entry)
532 		if (dr->ifp == ifp && IN6_ARE_ADDR_EQUAL(addr, &dr->rtaddr)) {
533 			defrouter_ref(dr);
534 			return (dr);
535 		}
536 	return (NULL);
537 }
538 
539 struct nd_defrouter *
540 defrouter_lookup(struct in6_addr *addr, struct ifnet *ifp)
541 {
542 	struct nd_defrouter *dr;
543 
544 	ND6_RLOCK();
545 	dr = defrouter_lookup_locked(addr, ifp);
546 	ND6_RUNLOCK();
547 	return (dr);
548 }
549 
550 void
551 defrouter_ref(struct nd_defrouter *dr)
552 {
553 
554 	refcount_acquire(&dr->refcnt);
555 }
556 
557 void
558 defrouter_rele(struct nd_defrouter *dr)
559 {
560 
561 	if (refcount_release(&dr->refcnt))
562 		free(dr, M_IP6NDP);
563 }
564 
565 /*
566  * Remove the default route for a given router.
567  * This is just a subroutine function for defrouter_select_fib(), and
568  * should not be called from anywhere else.
569  */
570 static void
571 defrouter_delreq(struct nd_defrouter *dr)
572 {
573 	struct sockaddr_in6 def, mask, gate;
574 	struct rtentry *oldrt = NULL;
575 
576 	bzero(&def, sizeof(def));
577 	bzero(&mask, sizeof(mask));
578 	bzero(&gate, sizeof(gate));
579 
580 	def.sin6_len = mask.sin6_len = gate.sin6_len =
581 	    sizeof(struct sockaddr_in6);
582 	def.sin6_family = gate.sin6_family = AF_INET6;
583 	gate.sin6_addr = dr->rtaddr;
584 
585 	in6_rtrequest(RTM_DELETE, (struct sockaddr *)&def,
586 	    (struct sockaddr *)&gate,
587 	    (struct sockaddr *)&mask, RTF_GATEWAY, &oldrt, dr->ifp->if_fib);
588 	if (oldrt) {
589 		nd6_rtmsg(RTM_DELETE, oldrt);
590 		RTFREE(oldrt);
591 	}
592 
593 	dr->installed = 0;
594 }
595 
596 /*
597  * Remove all default routes from default router list.
598  */
599 void
600 defrouter_reset(void)
601 {
602 	struct nd_defrouter *dr, **dra;
603 	int count, i;
604 
605 	count = i = 0;
606 
607 	/*
608 	 * We can't delete routes with the ND lock held, so make a copy of the
609 	 * current default router list and use that when deleting routes.
610 	 */
611 	ND6_RLOCK();
612 	TAILQ_FOREACH(dr, &V_nd_defrouter, dr_entry)
613 		count++;
614 	ND6_RUNLOCK();
615 
616 	dra = malloc(count * sizeof(*dra), M_TEMP, M_WAITOK | M_ZERO);
617 
618 	ND6_RLOCK();
619 	TAILQ_FOREACH(dr, &V_nd_defrouter, dr_entry) {
620 		if (i == count)
621 			break;
622 		defrouter_ref(dr);
623 		dra[i++] = dr;
624 	}
625 	ND6_RUNLOCK();
626 
627 	for (i = 0; i < count && dra[i] != NULL; i++) {
628 		defrouter_delreq(dra[i]);
629 		defrouter_rele(dra[i]);
630 	}
631 	free(dra, M_TEMP);
632 
633 	/*
634 	 * XXX should we also nuke any default routers in the kernel, by
635 	 * going through them by rtalloc1()?
636 	 */
637 }
638 
639 /*
640  * Look up a matching default router list entry and remove it. Returns true if a
641  * matching entry was found, false otherwise.
642  */
643 bool
644 defrouter_remove(struct in6_addr *addr, struct ifnet *ifp)
645 {
646 	struct nd_defrouter *dr;
647 
648 	ND6_WLOCK();
649 	dr = defrouter_lookup_locked(addr, ifp);
650 	if (dr == NULL) {
651 		ND6_WUNLOCK();
652 		return (false);
653 	}
654 
655 	defrouter_unlink(dr, NULL);
656 	ND6_WUNLOCK();
657 	defrouter_del(dr);
658 	defrouter_rele(dr);
659 	return (true);
660 }
661 
662 /*
663  * Remove a router from the global list and optionally stash it in a
664  * caller-supplied queue.
665  *
666  * The ND lock must be held.
667  */
668 void
669 defrouter_unlink(struct nd_defrouter *dr, struct nd_drhead *drq)
670 {
671 
672 	ND6_WLOCK_ASSERT();
673 	TAILQ_REMOVE(&V_nd_defrouter, dr, dr_entry);
674 	V_nd6_list_genid++;
675 	if (drq != NULL)
676 		TAILQ_INSERT_TAIL(drq, dr, dr_entry);
677 }
678 
679 void
680 defrouter_del(struct nd_defrouter *dr)
681 {
682 	struct nd_defrouter *deldr = NULL;
683 	struct nd_prefix *pr;
684 	struct nd_pfxrouter *pfxrtr;
685 
686 	ND6_UNLOCK_ASSERT();
687 
688 	/*
689 	 * Flush all the routing table entries that use the router
690 	 * as a next hop.
691 	 */
692 	if (ND_IFINFO(dr->ifp)->flags & ND6_IFF_ACCEPT_RTADV)
693 		rt6_flush(&dr->rtaddr, dr->ifp);
694 
695 	if (dr->installed) {
696 		deldr = dr;
697 		defrouter_delreq(dr);
698 	}
699 
700 	/*
701 	 * Also delete all the pointers to the router in each prefix lists.
702 	 */
703 	ND6_WLOCK();
704 	LIST_FOREACH(pr, &V_nd_prefix, ndpr_entry) {
705 		if ((pfxrtr = pfxrtr_lookup(pr, dr)) != NULL)
706 			pfxrtr_del(pfxrtr);
707 	}
708 	ND6_WUNLOCK();
709 
710 	pfxlist_onlink_check();
711 
712 	/*
713 	 * If the router is the primary one, choose a new one.
714 	 * Note that defrouter_select_fib() will remove the current
715          * gateway from the routing table.
716 	 */
717 	if (deldr)
718 		defrouter_select_fib(deldr->ifp->if_fib);
719 
720 	/*
721 	 * Release the list reference.
722 	 */
723 	defrouter_rele(dr);
724 }
725 
726 /*
727  * Default Router Selection according to Section 6.3.6 of RFC 2461 and
728  * draft-ietf-ipngwg-router-selection:
729  * 1) Routers that are reachable or probably reachable should be preferred.
730  *    If we have more than one (probably) reachable router, prefer ones
731  *    with the highest router preference.
732  * 2) When no routers on the list are known to be reachable or
733  *    probably reachable, routers SHOULD be selected in a round-robin
734  *    fashion, regardless of router preference values.
735  * 3) If the Default Router List is empty, assume that all
736  *    destinations are on-link.
737  *
738  * We assume nd_defrouter is sorted by router preference value.
739  * Since the code below covers both with and without router preference cases,
740  * we do not need to classify the cases by ifdef.
741  *
742  * At this moment, we do not try to install more than one default router,
743  * even when the multipath routing is available, because we're not sure about
744  * the benefits for stub hosts comparing to the risk of making the code
745  * complicated and the possibility of introducing bugs.
746  *
747  * We maintain a single list of routers for multiple FIBs, only considering one
748  * at a time based on the receiving interface's FIB. If @fibnum is RT_ALL_FIBS,
749  * we do the whole thing multiple times.
750  */
751 void
752 defrouter_select_fib(int fibnum)
753 {
754 	struct nd_defrouter *dr, *selected_dr, *installed_dr;
755 	struct llentry *ln = NULL;
756 
757 	if (fibnum == RT_ALL_FIBS) {
758 		for (fibnum = 0; fibnum < rt_numfibs; fibnum++) {
759 			defrouter_select_fib(fibnum);
760 		}
761 	}
762 
763 	ND6_RLOCK();
764 	/*
765 	 * Let's handle easy case (3) first:
766 	 * If default router list is empty, there's nothing to be done.
767 	 */
768 	if (TAILQ_EMPTY(&V_nd_defrouter)) {
769 		ND6_RUNLOCK();
770 		return;
771 	}
772 
773 	/*
774 	 * Search for a (probably) reachable router from the list.
775 	 * We just pick up the first reachable one (if any), assuming that
776 	 * the ordering rule of the list described in defrtrlist_update().
777 	 */
778 	selected_dr = installed_dr = NULL;
779 	TAILQ_FOREACH(dr, &V_nd_defrouter, dr_entry) {
780 		IF_AFDATA_RLOCK(dr->ifp);
781 		if (selected_dr == NULL && dr->ifp->if_fib == fibnum &&
782 		    (ln = nd6_lookup(&dr->rtaddr, 0, dr->ifp)) &&
783 		    ND6_IS_LLINFO_PROBREACH(ln)) {
784 			selected_dr = dr;
785 			defrouter_ref(selected_dr);
786 		}
787 		IF_AFDATA_RUNLOCK(dr->ifp);
788 		if (ln != NULL) {
789 			LLE_RUNLOCK(ln);
790 			ln = NULL;
791 		}
792 
793 		if (dr->installed && dr->ifp->if_fib == fibnum) {
794 			if (installed_dr == NULL) {
795 				installed_dr = dr;
796 				defrouter_ref(installed_dr);
797 			} else {
798 				/*
799 				 * this should not happen.
800 				 * warn for diagnosis.
801 				 */
802 				log(LOG_ERR, "defrouter_select_fib: more than "
803 				             "one router is installed\n");
804 			}
805 		}
806 	}
807 	/*
808 	 * If none of the default routers was found to be reachable,
809 	 * round-robin the list regardless of preference.
810 	 * Otherwise, if we have an installed router, check if the selected
811 	 * (reachable) router should really be preferred to the installed one.
812 	 * We only prefer the new router when the old one is not reachable
813 	 * or when the new one has a really higher preference value.
814 	 */
815 	if (selected_dr == NULL) {
816 		if (installed_dr == NULL ||
817 		    TAILQ_NEXT(installed_dr, dr_entry) == NULL)
818 			dr = TAILQ_FIRST(&V_nd_defrouter);
819 		else
820 			dr = TAILQ_NEXT(installed_dr, dr_entry);
821 
822 		/* Ensure we select a router for this FIB. */
823 		TAILQ_FOREACH_FROM(dr, &V_nd_defrouter, dr_entry) {
824 			if (dr->ifp->if_fib == fibnum) {
825 				selected_dr = dr;
826 				defrouter_ref(selected_dr);
827 				break;
828 			}
829 		}
830 	} else if (installed_dr != NULL) {
831 		IF_AFDATA_RLOCK(installed_dr->ifp);
832 		if ((ln = nd6_lookup(&installed_dr->rtaddr, 0,
833 		                     installed_dr->ifp)) &&
834 		    ND6_IS_LLINFO_PROBREACH(ln) &&
835 		    installed_dr->ifp->if_fib == fibnum &&
836 		    rtpref(selected_dr) <= rtpref(installed_dr)) {
837 			defrouter_rele(selected_dr);
838 			selected_dr = installed_dr;
839 		}
840 		IF_AFDATA_RUNLOCK(installed_dr->ifp);
841 		if (ln != NULL)
842 			LLE_RUNLOCK(ln);
843 	}
844 	ND6_RUNLOCK();
845 
846 	/*
847 	 * If we selected a router for this FIB and it's different
848 	 * than the installed one, remove the installed router and
849 	 * install the selected one in its place.
850 	 */
851 	if (installed_dr != selected_dr) {
852 		if (installed_dr != NULL) {
853 			defrouter_delreq(installed_dr);
854 			defrouter_rele(installed_dr);
855 		}
856 		if (selected_dr != NULL)
857 			defrouter_addreq(selected_dr);
858 	}
859 	if (selected_dr != NULL)
860 		defrouter_rele(selected_dr);
861 }
862 
863 /*
864  * Maintain old KPI for default router selection.
865  * If unspecified, we can re-select routers for all FIBs.
866  */
867 void
868 defrouter_select(void)
869 {
870 	defrouter_select_fib(RT_ALL_FIBS);
871 }
872 
873 /*
874  * for default router selection
875  * regards router-preference field as a 2-bit signed integer
876  */
877 static int
878 rtpref(struct nd_defrouter *dr)
879 {
880 	switch (dr->raflags & ND_RA_FLAG_RTPREF_MASK) {
881 	case ND_RA_FLAG_RTPREF_HIGH:
882 		return (RTPREF_HIGH);
883 	case ND_RA_FLAG_RTPREF_MEDIUM:
884 	case ND_RA_FLAG_RTPREF_RSV:
885 		return (RTPREF_MEDIUM);
886 	case ND_RA_FLAG_RTPREF_LOW:
887 		return (RTPREF_LOW);
888 	default:
889 		/*
890 		 * This case should never happen.  If it did, it would mean a
891 		 * serious bug of kernel internal.  We thus always bark here.
892 		 * Or, can we even panic?
893 		 */
894 		log(LOG_ERR, "rtpref: impossible RA flag %x\n", dr->raflags);
895 		return (RTPREF_INVALID);
896 	}
897 	/* NOTREACHED */
898 }
899 
900 static struct nd_defrouter *
901 defrtrlist_update(struct nd_defrouter *new)
902 {
903 	struct nd_defrouter *dr, *n;
904 	uint64_t genid;
905 	int oldpref;
906 	bool writelocked;
907 
908 	if (new->rtlifetime == 0) {
909 		defrouter_remove(&new->rtaddr, new->ifp);
910 		return (NULL);
911 	}
912 
913 	ND6_RLOCK();
914 	writelocked = false;
915 restart:
916 	dr = defrouter_lookup_locked(&new->rtaddr, new->ifp);
917 	if (dr != NULL) {
918 		oldpref = rtpref(dr);
919 
920 		/* override */
921 		dr->raflags = new->raflags; /* XXX flag check */
922 		dr->rtlifetime = new->rtlifetime;
923 		dr->expire = new->expire;
924 
925 		/*
926 		 * If the preference does not change, there's no need
927 		 * to sort the entries. Also make sure the selected
928 		 * router is still installed in the kernel.
929 		 */
930 		if (dr->installed && rtpref(new) == oldpref) {
931 			if (writelocked)
932 				ND6_WUNLOCK();
933 			else
934 				ND6_RUNLOCK();
935 			return (dr);
936 		}
937 	}
938 
939 	/*
940 	 * The router needs to be reinserted into the default router
941 	 * list, so upgrade to a write lock. If that fails and the list
942 	 * has potentially changed while the lock was dropped, we'll
943 	 * redo the lookup with the write lock held.
944 	 */
945 	if (!writelocked) {
946 		writelocked = true;
947 		if (!ND6_TRY_UPGRADE()) {
948 			genid = V_nd6_list_genid;
949 			ND6_RUNLOCK();
950 			ND6_WLOCK();
951 			if (genid != V_nd6_list_genid)
952 				goto restart;
953 		}
954 	}
955 
956 	if (dr != NULL) {
957 		/*
958 		 * The preferred router may have changed, so relocate this
959 		 * router.
960 		 */
961 		TAILQ_REMOVE(&V_nd_defrouter, dr, dr_entry);
962 		n = dr;
963 	} else {
964 		n = malloc(sizeof(*n), M_IP6NDP, M_NOWAIT | M_ZERO);
965 		if (n == NULL) {
966 			ND6_WUNLOCK();
967 			return (NULL);
968 		}
969 		memcpy(n, new, sizeof(*n));
970 		/* Initialize with an extra reference for the caller. */
971 		refcount_init(&n->refcnt, 2);
972 	}
973 
974 	/*
975 	 * Insert the new router in the Default Router List;
976 	 * The Default Router List should be in the descending order
977 	 * of router-preferece.  Routers with the same preference are
978 	 * sorted in the arriving time order.
979 	 */
980 
981 	/* insert at the end of the group */
982 	TAILQ_FOREACH(dr, &V_nd_defrouter, dr_entry) {
983 		if (rtpref(n) > rtpref(dr))
984 			break;
985 	}
986 	if (dr != NULL)
987 		TAILQ_INSERT_BEFORE(dr, n, dr_entry);
988 	else
989 		TAILQ_INSERT_TAIL(&V_nd_defrouter, n, dr_entry);
990 	V_nd6_list_genid++;
991 	ND6_WUNLOCK();
992 
993 	defrouter_select_fib(new->ifp->if_fib);
994 
995 	return (n);
996 }
997 
998 static struct nd_pfxrouter *
999 pfxrtr_lookup(struct nd_prefix *pr, struct nd_defrouter *dr)
1000 {
1001 	struct nd_pfxrouter *search;
1002 
1003 	ND6_LOCK_ASSERT();
1004 
1005 	LIST_FOREACH(search, &pr->ndpr_advrtrs, pfr_entry) {
1006 		if (search->router == dr)
1007 			break;
1008 	}
1009 	return (search);
1010 }
1011 
1012 static void
1013 pfxrtr_add(struct nd_prefix *pr, struct nd_defrouter *dr)
1014 {
1015 	struct nd_pfxrouter *new;
1016 	bool update;
1017 
1018 	ND6_UNLOCK_ASSERT();
1019 
1020 	ND6_RLOCK();
1021 	if (pfxrtr_lookup(pr, dr) != NULL) {
1022 		ND6_RUNLOCK();
1023 		return;
1024 	}
1025 	ND6_RUNLOCK();
1026 
1027 	new = malloc(sizeof(*new), M_IP6NDP, M_NOWAIT | M_ZERO);
1028 	if (new == NULL)
1029 		return;
1030 	defrouter_ref(dr);
1031 	new->router = dr;
1032 
1033 	ND6_WLOCK();
1034 	if (pfxrtr_lookup(pr, dr) == NULL) {
1035 		LIST_INSERT_HEAD(&pr->ndpr_advrtrs, new, pfr_entry);
1036 		update = true;
1037 	} else {
1038 		/* We lost a race to add the reference. */
1039 		defrouter_rele(dr);
1040 		free(new, M_IP6NDP);
1041 		update = false;
1042 	}
1043 	ND6_WUNLOCK();
1044 
1045 	if (update)
1046 		pfxlist_onlink_check();
1047 }
1048 
1049 static void
1050 pfxrtr_del(struct nd_pfxrouter *pfr)
1051 {
1052 
1053 	ND6_WLOCK_ASSERT();
1054 
1055 	LIST_REMOVE(pfr, pfr_entry);
1056 	defrouter_rele(pfr->router);
1057 	free(pfr, M_IP6NDP);
1058 }
1059 
1060 static struct nd_prefix *
1061 nd6_prefix_lookup_locked(struct nd_prefixctl *key)
1062 {
1063 	struct nd_prefix *search;
1064 
1065 	ND6_LOCK_ASSERT();
1066 
1067 	LIST_FOREACH(search, &V_nd_prefix, ndpr_entry) {
1068 		if (key->ndpr_ifp == search->ndpr_ifp &&
1069 		    key->ndpr_plen == search->ndpr_plen &&
1070 		    in6_are_prefix_equal(&key->ndpr_prefix.sin6_addr,
1071 		    &search->ndpr_prefix.sin6_addr, key->ndpr_plen)) {
1072 			nd6_prefix_ref(search);
1073 			break;
1074 		}
1075 	}
1076 	return (search);
1077 }
1078 
1079 struct nd_prefix *
1080 nd6_prefix_lookup(struct nd_prefixctl *key)
1081 {
1082 	struct nd_prefix *search;
1083 
1084 	ND6_RLOCK();
1085 	search = nd6_prefix_lookup_locked(key);
1086 	ND6_RUNLOCK();
1087 	return (search);
1088 }
1089 
1090 void
1091 nd6_prefix_ref(struct nd_prefix *pr)
1092 {
1093 
1094 	refcount_acquire(&pr->ndpr_refcnt);
1095 }
1096 
1097 void
1098 nd6_prefix_rele(struct nd_prefix *pr)
1099 {
1100 
1101 	if (refcount_release(&pr->ndpr_refcnt)) {
1102 		KASSERT(LIST_EMPTY(&pr->ndpr_advrtrs),
1103 		    ("prefix %p has advertising routers", pr));
1104 		free(pr, M_IP6NDP);
1105 	}
1106 }
1107 
1108 int
1109 nd6_prelist_add(struct nd_prefixctl *pr, struct nd_defrouter *dr,
1110     struct nd_prefix **newp)
1111 {
1112 	struct nd_prefix *new;
1113 	char ip6buf[INET6_ADDRSTRLEN];
1114 	int error;
1115 
1116 	new = malloc(sizeof(*new), M_IP6NDP, M_NOWAIT | M_ZERO);
1117 	if (new == NULL)
1118 		return (ENOMEM);
1119 	refcount_init(&new->ndpr_refcnt, newp != NULL ? 2 : 1);
1120 	new->ndpr_ifp = pr->ndpr_ifp;
1121 	new->ndpr_prefix = pr->ndpr_prefix;
1122 	new->ndpr_plen = pr->ndpr_plen;
1123 	new->ndpr_vltime = pr->ndpr_vltime;
1124 	new->ndpr_pltime = pr->ndpr_pltime;
1125 	new->ndpr_flags = pr->ndpr_flags;
1126 	if ((error = in6_init_prefix_ltimes(new)) != 0) {
1127 		free(new, M_IP6NDP);
1128 		return (error);
1129 	}
1130 	new->ndpr_lastupdate = time_uptime;
1131 
1132 	/* initialization */
1133 	LIST_INIT(&new->ndpr_advrtrs);
1134 	in6_prefixlen2mask(&new->ndpr_mask, new->ndpr_plen);
1135 	/* make prefix in the canonical form */
1136 	IN6_MASK_ADDR(&new->ndpr_prefix.sin6_addr, &new->ndpr_mask);
1137 
1138 	ND6_WLOCK();
1139 	LIST_INSERT_HEAD(&V_nd_prefix, new, ndpr_entry);
1140 	V_nd6_list_genid++;
1141 	ND6_WUNLOCK();
1142 
1143 	/* ND_OPT_PI_FLAG_ONLINK processing */
1144 	if (new->ndpr_raf_onlink) {
1145 		ND6_ONLINK_LOCK();
1146 		if ((error = nd6_prefix_onlink(new)) != 0) {
1147 			nd6log((LOG_ERR, "nd6_prelist_add: failed to make "
1148 			    "the prefix %s/%d on-link on %s (errno=%d)\n",
1149 			    ip6_sprintf(ip6buf, &pr->ndpr_prefix.sin6_addr),
1150 			    pr->ndpr_plen, if_name(pr->ndpr_ifp), error));
1151 			/* proceed anyway. XXX: is it correct? */
1152 		}
1153 		ND6_ONLINK_UNLOCK();
1154 	}
1155 
1156 	if (dr != NULL)
1157 		pfxrtr_add(new, dr);
1158 	if (newp != NULL)
1159 		*newp = new;
1160 	return (0);
1161 }
1162 
1163 /*
1164  * Remove a prefix from the prefix list and optionally stash it in a
1165  * caller-provided list.
1166  *
1167  * The ND6 lock must be held.
1168  */
1169 void
1170 nd6_prefix_unlink(struct nd_prefix *pr, struct nd_prhead *list)
1171 {
1172 
1173 	ND6_WLOCK_ASSERT();
1174 
1175 	LIST_REMOVE(pr, ndpr_entry);
1176 	V_nd6_list_genid++;
1177 	if (list != NULL)
1178 		LIST_INSERT_HEAD(list, pr, ndpr_entry);
1179 }
1180 
1181 /*
1182  * Free an unlinked prefix, first marking it off-link if necessary.
1183  */
1184 void
1185 nd6_prefix_del(struct nd_prefix *pr)
1186 {
1187 	struct nd_pfxrouter *pfr, *next;
1188 	int e;
1189 	char ip6buf[INET6_ADDRSTRLEN];
1190 
1191 	KASSERT(pr->ndpr_addrcnt == 0,
1192 	    ("prefix %p has referencing addresses", pr));
1193 	ND6_UNLOCK_ASSERT();
1194 
1195 	/*
1196 	 * Though these flags are now meaningless, we'd rather keep the value
1197 	 * of pr->ndpr_raf_onlink and pr->ndpr_raf_auto not to confuse users
1198 	 * when executing "ndp -p".
1199 	 */
1200 	if ((pr->ndpr_stateflags & NDPRF_ONLINK) != 0) {
1201 		ND6_ONLINK_LOCK();
1202 		if ((e = nd6_prefix_offlink(pr)) != 0) {
1203 			nd6log((LOG_ERR,
1204 			    "nd6_prefix_del: failed to make %s/%d offlink "
1205 			    "on %s, errno=%d\n",
1206 			    ip6_sprintf(ip6buf, &pr->ndpr_prefix.sin6_addr),
1207 			    pr->ndpr_plen, if_name(pr->ndpr_ifp), e));
1208 			/* what should we do? */
1209 		}
1210 		ND6_ONLINK_UNLOCK();
1211 	}
1212 
1213 	/* Release references to routers that have advertised this prefix. */
1214 	ND6_WLOCK();
1215 	LIST_FOREACH_SAFE(pfr, &pr->ndpr_advrtrs, pfr_entry, next)
1216 		pfxrtr_del(pfr);
1217 	ND6_WUNLOCK();
1218 
1219 	nd6_prefix_rele(pr);
1220 
1221 	pfxlist_onlink_check();
1222 }
1223 
1224 static int
1225 prelist_update(struct nd_prefixctl *new, struct nd_defrouter *dr,
1226     struct mbuf *m, int mcast)
1227 {
1228 	struct in6_ifaddr *ia6 = NULL, *ia6_match = NULL;
1229 	struct ifaddr *ifa;
1230 	struct ifnet *ifp = new->ndpr_ifp;
1231 	struct nd_prefix *pr;
1232 	int error = 0;
1233 	int auth;
1234 	struct in6_addrlifetime lt6_tmp;
1235 	char ip6buf[INET6_ADDRSTRLEN];
1236 
1237 	auth = 0;
1238 	if (m) {
1239 		/*
1240 		 * Authenticity for NA consists authentication for
1241 		 * both IP header and IP datagrams, doesn't it ?
1242 		 */
1243 #if defined(M_AUTHIPHDR) && defined(M_AUTHIPDGM)
1244 		auth = ((m->m_flags & M_AUTHIPHDR) &&
1245 		    (m->m_flags & M_AUTHIPDGM));
1246 #endif
1247 	}
1248 
1249 	if ((pr = nd6_prefix_lookup(new)) != NULL) {
1250 		/*
1251 		 * nd6_prefix_lookup() ensures that pr and new have the same
1252 		 * prefix on a same interface.
1253 		 */
1254 
1255 		/*
1256 		 * Update prefix information.  Note that the on-link (L) bit
1257 		 * and the autonomous (A) bit should NOT be changed from 1
1258 		 * to 0.
1259 		 */
1260 		if (new->ndpr_raf_onlink == 1)
1261 			pr->ndpr_raf_onlink = 1;
1262 		if (new->ndpr_raf_auto == 1)
1263 			pr->ndpr_raf_auto = 1;
1264 		if (new->ndpr_raf_onlink) {
1265 			pr->ndpr_vltime = new->ndpr_vltime;
1266 			pr->ndpr_pltime = new->ndpr_pltime;
1267 			(void)in6_init_prefix_ltimes(pr); /* XXX error case? */
1268 			pr->ndpr_lastupdate = time_uptime;
1269 		}
1270 
1271 		if (new->ndpr_raf_onlink &&
1272 		    (pr->ndpr_stateflags & NDPRF_ONLINK) == 0) {
1273 			ND6_ONLINK_LOCK();
1274 			if ((error = nd6_prefix_onlink(pr)) != 0) {
1275 				nd6log((LOG_ERR,
1276 				    "prelist_update: failed to make "
1277 				    "the prefix %s/%d on-link on %s "
1278 				    "(errno=%d)\n",
1279 				    ip6_sprintf(ip6buf,
1280 				        &pr->ndpr_prefix.sin6_addr),
1281 				    pr->ndpr_plen, if_name(pr->ndpr_ifp),
1282 				    error));
1283 				/* proceed anyway. XXX: is it correct? */
1284 			}
1285 			ND6_ONLINK_UNLOCK();
1286 		}
1287 
1288 		if (dr != NULL)
1289 			pfxrtr_add(pr, dr);
1290 	} else {
1291 		if (new->ndpr_vltime == 0)
1292 			goto end;
1293 		if (new->ndpr_raf_onlink == 0 && new->ndpr_raf_auto == 0)
1294 			goto end;
1295 
1296 		error = nd6_prelist_add(new, dr, &pr);
1297 		if (error != 0) {
1298 			nd6log((LOG_NOTICE, "prelist_update: "
1299 			    "nd6_prelist_add failed for %s/%d on %s errno=%d\n",
1300 			    ip6_sprintf(ip6buf, &new->ndpr_prefix.sin6_addr),
1301 			    new->ndpr_plen, if_name(new->ndpr_ifp), error));
1302 			goto end; /* we should just give up in this case. */
1303 		}
1304 
1305 		/*
1306 		 * XXX: from the ND point of view, we can ignore a prefix
1307 		 * with the on-link bit being zero.  However, we need a
1308 		 * prefix structure for references from autoconfigured
1309 		 * addresses.  Thus, we explicitly make sure that the prefix
1310 		 * itself expires now.
1311 		 */
1312 		if (pr->ndpr_raf_onlink == 0) {
1313 			pr->ndpr_vltime = 0;
1314 			pr->ndpr_pltime = 0;
1315 			in6_init_prefix_ltimes(pr);
1316 		}
1317 	}
1318 
1319 	/*
1320 	 * Address autoconfiguration based on Section 5.5.3 of RFC 2462.
1321 	 * Note that pr must be non NULL at this point.
1322 	 */
1323 
1324 	/* 5.5.3 (a). Ignore the prefix without the A bit set. */
1325 	if (!new->ndpr_raf_auto)
1326 		goto end;
1327 
1328 	/*
1329 	 * 5.5.3 (b). the link-local prefix should have been ignored in
1330 	 * nd6_ra_input.
1331 	 */
1332 
1333 	/* 5.5.3 (c). Consistency check on lifetimes: pltime <= vltime. */
1334 	if (new->ndpr_pltime > new->ndpr_vltime) {
1335 		error = EINVAL;	/* XXX: won't be used */
1336 		goto end;
1337 	}
1338 
1339 	/*
1340 	 * 5.5.3 (d).  If the prefix advertised is not equal to the prefix of
1341 	 * an address configured by stateless autoconfiguration already in the
1342 	 * list of addresses associated with the interface, and the Valid
1343 	 * Lifetime is not 0, form an address.  We first check if we have
1344 	 * a matching prefix.
1345 	 * Note: we apply a clarification in rfc2462bis-02 here.  We only
1346 	 * consider autoconfigured addresses while RFC2462 simply said
1347 	 * "address".
1348 	 */
1349 	IF_ADDR_RLOCK(ifp);
1350 	TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1351 		struct in6_ifaddr *ifa6;
1352 		u_int32_t remaininglifetime;
1353 
1354 		if (ifa->ifa_addr->sa_family != AF_INET6)
1355 			continue;
1356 
1357 		ifa6 = (struct in6_ifaddr *)ifa;
1358 
1359 		/*
1360 		 * We only consider autoconfigured addresses as per rfc2462bis.
1361 		 */
1362 		if (!(ifa6->ia6_flags & IN6_IFF_AUTOCONF))
1363 			continue;
1364 
1365 		/*
1366 		 * Spec is not clear here, but I believe we should concentrate
1367 		 * on unicast (i.e. not anycast) addresses.
1368 		 * XXX: other ia6_flags? detached or duplicated?
1369 		 */
1370 		if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0)
1371 			continue;
1372 
1373 		/*
1374 		 * Ignore the address if it is not associated with a prefix
1375 		 * or is associated with a prefix that is different from this
1376 		 * one.  (pr is never NULL here)
1377 		 */
1378 		if (ifa6->ia6_ndpr != pr)
1379 			continue;
1380 
1381 		if (ia6_match == NULL) /* remember the first one */
1382 			ia6_match = ifa6;
1383 
1384 		/*
1385 		 * An already autoconfigured address matched.  Now that we
1386 		 * are sure there is at least one matched address, we can
1387 		 * proceed to 5.5.3. (e): update the lifetimes according to the
1388 		 * "two hours" rule and the privacy extension.
1389 		 * We apply some clarifications in rfc2462bis:
1390 		 * - use remaininglifetime instead of storedlifetime as a
1391 		 *   variable name
1392 		 * - remove the dead code in the "two-hour" rule
1393 		 */
1394 #define TWOHOUR		(120*60)
1395 		lt6_tmp = ifa6->ia6_lifetime;
1396 
1397 		if (lt6_tmp.ia6t_vltime == ND6_INFINITE_LIFETIME)
1398 			remaininglifetime = ND6_INFINITE_LIFETIME;
1399 		else if (time_uptime - ifa6->ia6_updatetime >
1400 			 lt6_tmp.ia6t_vltime) {
1401 			/*
1402 			 * The case of "invalid" address.  We should usually
1403 			 * not see this case.
1404 			 */
1405 			remaininglifetime = 0;
1406 		} else
1407 			remaininglifetime = lt6_tmp.ia6t_vltime -
1408 			    (time_uptime - ifa6->ia6_updatetime);
1409 
1410 		/* when not updating, keep the current stored lifetime. */
1411 		lt6_tmp.ia6t_vltime = remaininglifetime;
1412 
1413 		if (TWOHOUR < new->ndpr_vltime ||
1414 		    remaininglifetime < new->ndpr_vltime) {
1415 			lt6_tmp.ia6t_vltime = new->ndpr_vltime;
1416 		} else if (remaininglifetime <= TWOHOUR) {
1417 			if (auth) {
1418 				lt6_tmp.ia6t_vltime = new->ndpr_vltime;
1419 			}
1420 		} else {
1421 			/*
1422 			 * new->ndpr_vltime <= TWOHOUR &&
1423 			 * TWOHOUR < remaininglifetime
1424 			 */
1425 			lt6_tmp.ia6t_vltime = TWOHOUR;
1426 		}
1427 
1428 		/* The 2 hour rule is not imposed for preferred lifetime. */
1429 		lt6_tmp.ia6t_pltime = new->ndpr_pltime;
1430 
1431 		in6_init_address_ltimes(pr, &lt6_tmp);
1432 
1433 		/*
1434 		 * We need to treat lifetimes for temporary addresses
1435 		 * differently, according to
1436 		 * draft-ietf-ipv6-privacy-addrs-v2-01.txt 3.3 (1);
1437 		 * we only update the lifetimes when they are in the maximum
1438 		 * intervals.
1439 		 */
1440 		if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0) {
1441 			u_int32_t maxvltime, maxpltime;
1442 
1443 			if (V_ip6_temp_valid_lifetime >
1444 			    (u_int32_t)((time_uptime - ifa6->ia6_createtime) +
1445 			    V_ip6_desync_factor)) {
1446 				maxvltime = V_ip6_temp_valid_lifetime -
1447 				    (time_uptime - ifa6->ia6_createtime) -
1448 				    V_ip6_desync_factor;
1449 			} else
1450 				maxvltime = 0;
1451 			if (V_ip6_temp_preferred_lifetime >
1452 			    (u_int32_t)((time_uptime - ifa6->ia6_createtime) +
1453 			    V_ip6_desync_factor)) {
1454 				maxpltime = V_ip6_temp_preferred_lifetime -
1455 				    (time_uptime - ifa6->ia6_createtime) -
1456 				    V_ip6_desync_factor;
1457 			} else
1458 				maxpltime = 0;
1459 
1460 			if (lt6_tmp.ia6t_vltime == ND6_INFINITE_LIFETIME ||
1461 			    lt6_tmp.ia6t_vltime > maxvltime) {
1462 				lt6_tmp.ia6t_vltime = maxvltime;
1463 			}
1464 			if (lt6_tmp.ia6t_pltime == ND6_INFINITE_LIFETIME ||
1465 			    lt6_tmp.ia6t_pltime > maxpltime) {
1466 				lt6_tmp.ia6t_pltime = maxpltime;
1467 			}
1468 		}
1469 		ifa6->ia6_lifetime = lt6_tmp;
1470 		ifa6->ia6_updatetime = time_uptime;
1471 	}
1472 	IF_ADDR_RUNLOCK(ifp);
1473 	if (ia6_match == NULL && new->ndpr_vltime) {
1474 		int ifidlen;
1475 
1476 		/*
1477 		 * 5.5.3 (d) (continued)
1478 		 * No address matched and the valid lifetime is non-zero.
1479 		 * Create a new address.
1480 		 */
1481 
1482 		/*
1483 		 * Prefix Length check:
1484 		 * If the sum of the prefix length and interface identifier
1485 		 * length does not equal 128 bits, the Prefix Information
1486 		 * option MUST be ignored.  The length of the interface
1487 		 * identifier is defined in a separate link-type specific
1488 		 * document.
1489 		 */
1490 		ifidlen = in6_if2idlen(ifp);
1491 		if (ifidlen < 0) {
1492 			/* this should not happen, so we always log it. */
1493 			log(LOG_ERR, "prelist_update: IFID undefined (%s)\n",
1494 			    if_name(ifp));
1495 			goto end;
1496 		}
1497 		if (ifidlen + pr->ndpr_plen != 128) {
1498 			nd6log((LOG_INFO,
1499 			    "prelist_update: invalid prefixlen "
1500 			    "%d for %s, ignored\n",
1501 			    pr->ndpr_plen, if_name(ifp)));
1502 			goto end;
1503 		}
1504 
1505 		if ((ia6 = in6_ifadd(new, mcast)) != NULL) {
1506 			/*
1507 			 * note that we should use pr (not new) for reference.
1508 			 */
1509 			pr->ndpr_addrcnt++;
1510 			ia6->ia6_ndpr = pr;
1511 
1512 			/*
1513 			 * RFC 3041 3.3 (2).
1514 			 * When a new public address is created as described
1515 			 * in RFC2462, also create a new temporary address.
1516 			 *
1517 			 * RFC 3041 3.5.
1518 			 * When an interface connects to a new link, a new
1519 			 * randomized interface identifier should be generated
1520 			 * immediately together with a new set of temporary
1521 			 * addresses.  Thus, we specifiy 1 as the 2nd arg of
1522 			 * in6_tmpifadd().
1523 			 */
1524 			if (V_ip6_use_tempaddr) {
1525 				int e;
1526 				if ((e = in6_tmpifadd(ia6, 1, 1)) != 0) {
1527 					nd6log((LOG_NOTICE, "prelist_update: "
1528 					    "failed to create a temporary "
1529 					    "address, errno=%d\n",
1530 					    e));
1531 				}
1532 			}
1533 			ifa_free(&ia6->ia_ifa);
1534 
1535 			/*
1536 			 * A newly added address might affect the status
1537 			 * of other addresses, so we check and update it.
1538 			 * XXX: what if address duplication happens?
1539 			 */
1540 			pfxlist_onlink_check();
1541 		} else {
1542 			/* just set an error. do not bark here. */
1543 			error = EADDRNOTAVAIL; /* XXX: might be unused. */
1544 		}
1545 	}
1546 
1547 end:
1548 	if (pr != NULL)
1549 		nd6_prefix_rele(pr);
1550 	return (error);
1551 }
1552 
1553 /*
1554  * A supplement function used in the on-link detection below;
1555  * detect if a given prefix has a (probably) reachable advertising router.
1556  * XXX: lengthy function name...
1557  */
1558 static struct nd_pfxrouter *
1559 find_pfxlist_reachable_router(struct nd_prefix *pr)
1560 {
1561 	struct nd_pfxrouter *pfxrtr;
1562 	struct llentry *ln;
1563 	int canreach;
1564 
1565 	ND6_LOCK_ASSERT();
1566 
1567 	LIST_FOREACH(pfxrtr, &pr->ndpr_advrtrs, pfr_entry) {
1568 		IF_AFDATA_RLOCK(pfxrtr->router->ifp);
1569 		ln = nd6_lookup(&pfxrtr->router->rtaddr, 0, pfxrtr->router->ifp);
1570 		IF_AFDATA_RUNLOCK(pfxrtr->router->ifp);
1571 		if (ln == NULL)
1572 			continue;
1573 		canreach = ND6_IS_LLINFO_PROBREACH(ln);
1574 		LLE_RUNLOCK(ln);
1575 		if (canreach)
1576 			break;
1577 	}
1578 	return (pfxrtr);
1579 }
1580 
1581 /*
1582  * Check if each prefix in the prefix list has at least one available router
1583  * that advertised the prefix (a router is "available" if its neighbor cache
1584  * entry is reachable or probably reachable).
1585  * If the check fails, the prefix may be off-link, because, for example,
1586  * we have moved from the network but the lifetime of the prefix has not
1587  * expired yet.  So we should not use the prefix if there is another prefix
1588  * that has an available router.
1589  * But, if there is no prefix that has an available router, we still regard
1590  * all the prefixes as on-link.  This is because we can't tell if all the
1591  * routers are simply dead or if we really moved from the network and there
1592  * is no router around us.
1593  */
1594 void
1595 pfxlist_onlink_check(void)
1596 {
1597 	struct nd_prefix *pr;
1598 	struct in6_ifaddr *ifa;
1599 	struct nd_defrouter *dr;
1600 	struct nd_pfxrouter *pfxrtr = NULL;
1601 	struct rm_priotracker in6_ifa_tracker;
1602 	uint64_t genid;
1603 	uint32_t flags;
1604 
1605 	ND6_ONLINK_LOCK();
1606 	ND6_RLOCK();
1607 
1608 	/*
1609 	 * Check if there is a prefix that has a reachable advertising
1610 	 * router.
1611 	 */
1612 	LIST_FOREACH(pr, &V_nd_prefix, ndpr_entry) {
1613 		if (pr->ndpr_raf_onlink && find_pfxlist_reachable_router(pr))
1614 			break;
1615 	}
1616 
1617 	/*
1618 	 * If we have no such prefix, check whether we still have a router
1619 	 * that does not advertise any prefixes.
1620 	 */
1621 	if (pr == NULL) {
1622 		TAILQ_FOREACH(dr, &V_nd_defrouter, dr_entry) {
1623 			struct nd_prefix *pr0;
1624 
1625 			LIST_FOREACH(pr0, &V_nd_prefix, ndpr_entry) {
1626 				if ((pfxrtr = pfxrtr_lookup(pr0, dr)) != NULL)
1627 					break;
1628 			}
1629 			if (pfxrtr != NULL)
1630 				break;
1631 		}
1632 	}
1633 	if (pr != NULL || (!TAILQ_EMPTY(&V_nd_defrouter) && pfxrtr == NULL)) {
1634 		/*
1635 		 * There is at least one prefix that has a reachable router,
1636 		 * or at least a router which probably does not advertise
1637 		 * any prefixes.  The latter would be the case when we move
1638 		 * to a new link where we have a router that does not provide
1639 		 * prefixes and we configure an address by hand.
1640 		 * Detach prefixes which have no reachable advertising
1641 		 * router, and attach other prefixes.
1642 		 */
1643 		LIST_FOREACH(pr, &V_nd_prefix, ndpr_entry) {
1644 			/* XXX: a link-local prefix should never be detached */
1645 			if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr) ||
1646 			    pr->ndpr_raf_onlink == 0 ||
1647 			    pr->ndpr_raf_auto == 0)
1648 				continue;
1649 
1650 			if ((pr->ndpr_stateflags & NDPRF_DETACHED) == 0 &&
1651 			    find_pfxlist_reachable_router(pr) == NULL)
1652 				pr->ndpr_stateflags |= NDPRF_DETACHED;
1653 			else if ((pr->ndpr_stateflags & NDPRF_DETACHED) != 0 &&
1654 			    find_pfxlist_reachable_router(pr) != NULL)
1655 				pr->ndpr_stateflags &= ~NDPRF_DETACHED;
1656 		}
1657 	} else {
1658 		/* there is no prefix that has a reachable router */
1659 		LIST_FOREACH(pr, &V_nd_prefix, ndpr_entry) {
1660 			if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr) ||
1661 			    pr->ndpr_raf_onlink == 0 ||
1662 			    pr->ndpr_raf_auto == 0)
1663 				continue;
1664 			pr->ndpr_stateflags &= ~NDPRF_DETACHED;
1665 		}
1666 	}
1667 
1668 	/*
1669 	 * Remove each interface route associated with a (just) detached
1670 	 * prefix, and reinstall the interface route for a (just) attached
1671 	 * prefix.  Note that all attempt of reinstallation does not
1672 	 * necessarily success, when a same prefix is shared among multiple
1673 	 * interfaces.  Such cases will be handled in nd6_prefix_onlink,
1674 	 * so we don't have to care about them.
1675 	 */
1676 restart:
1677 	LIST_FOREACH(pr, &V_nd_prefix, ndpr_entry) {
1678 		char ip6buf[INET6_ADDRSTRLEN];
1679 		int e;
1680 
1681 		if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr) ||
1682 		    pr->ndpr_raf_onlink == 0 ||
1683 		    pr->ndpr_raf_auto == 0)
1684 			continue;
1685 
1686 		flags = pr->ndpr_stateflags & (NDPRF_DETACHED | NDPRF_ONLINK);
1687 		if (flags == 0 || flags == (NDPRF_DETACHED | NDPRF_ONLINK)) {
1688 			genid = V_nd6_list_genid;
1689 			ND6_RUNLOCK();
1690 			if ((flags & NDPRF_ONLINK) != 0 &&
1691 			    (e = nd6_prefix_offlink(pr)) != 0) {
1692 				nd6log((LOG_ERR,
1693 				    "pfxlist_onlink_check: failed to "
1694 				    "make %s/%d offlink, errno=%d\n",
1695 				    ip6_sprintf(ip6buf,
1696 					    &pr->ndpr_prefix.sin6_addr),
1697 					    pr->ndpr_plen, e));
1698 			} else if ((flags & NDPRF_ONLINK) == 0 &&
1699 			    (e = nd6_prefix_onlink(pr)) != 0) {
1700 				nd6log((LOG_ERR,
1701 				    "pfxlist_onlink_check: failed to "
1702 				    "make %s/%d onlink, errno=%d\n",
1703 				    ip6_sprintf(ip6buf,
1704 					    &pr->ndpr_prefix.sin6_addr),
1705 					    pr->ndpr_plen, e));
1706 			}
1707 			ND6_RLOCK();
1708 			if (genid != V_nd6_list_genid)
1709 				goto restart;
1710 		}
1711 	}
1712 
1713 	/*
1714 	 * Changes on the prefix status might affect address status as well.
1715 	 * Make sure that all addresses derived from an attached prefix are
1716 	 * attached, and that all addresses derived from a detached prefix are
1717 	 * detached.  Note, however, that a manually configured address should
1718 	 * always be attached.
1719 	 * The precise detection logic is same as the one for prefixes.
1720 	 */
1721 	IN6_IFADDR_RLOCK(&in6_ifa_tracker);
1722 	TAILQ_FOREACH(ifa, &V_in6_ifaddrhead, ia_link) {
1723 		if (!(ifa->ia6_flags & IN6_IFF_AUTOCONF))
1724 			continue;
1725 
1726 		if (ifa->ia6_ndpr == NULL) {
1727 			/*
1728 			 * This can happen when we first configure the address
1729 			 * (i.e. the address exists, but the prefix does not).
1730 			 * XXX: complicated relationships...
1731 			 */
1732 			continue;
1733 		}
1734 
1735 		if (find_pfxlist_reachable_router(ifa->ia6_ndpr))
1736 			break;
1737 	}
1738 	if (ifa) {
1739 		TAILQ_FOREACH(ifa, &V_in6_ifaddrhead, ia_link) {
1740 			if ((ifa->ia6_flags & IN6_IFF_AUTOCONF) == 0)
1741 				continue;
1742 
1743 			if (ifa->ia6_ndpr == NULL) /* XXX: see above. */
1744 				continue;
1745 
1746 			if (find_pfxlist_reachable_router(ifa->ia6_ndpr)) {
1747 				if (ifa->ia6_flags & IN6_IFF_DETACHED) {
1748 					ifa->ia6_flags &= ~IN6_IFF_DETACHED;
1749 					ifa->ia6_flags |= IN6_IFF_TENTATIVE;
1750 					nd6_dad_start((struct ifaddr *)ifa, 0);
1751 				}
1752 			} else {
1753 				ifa->ia6_flags |= IN6_IFF_DETACHED;
1754 			}
1755 		}
1756 	} else {
1757 		TAILQ_FOREACH(ifa, &V_in6_ifaddrhead, ia_link) {
1758 			if ((ifa->ia6_flags & IN6_IFF_AUTOCONF) == 0)
1759 				continue;
1760 
1761 			if (ifa->ia6_flags & IN6_IFF_DETACHED) {
1762 				ifa->ia6_flags &= ~IN6_IFF_DETACHED;
1763 				ifa->ia6_flags |= IN6_IFF_TENTATIVE;
1764 				/* Do we need a delay in this case? */
1765 				nd6_dad_start((struct ifaddr *)ifa, 0);
1766 			}
1767 		}
1768 	}
1769 	IN6_IFADDR_RUNLOCK(&in6_ifa_tracker);
1770 	ND6_RUNLOCK();
1771 	ND6_ONLINK_UNLOCK();
1772 }
1773 
1774 static int
1775 nd6_prefix_onlink_rtrequest(struct nd_prefix *pr, struct ifaddr *ifa)
1776 {
1777 	static struct sockaddr_dl null_sdl = {sizeof(null_sdl), AF_LINK};
1778 	struct rib_head *rnh;
1779 	struct rtentry *rt;
1780 	struct sockaddr_in6 mask6;
1781 	u_long rtflags;
1782 	int error, a_failure, fibnum, maxfib;
1783 
1784 	/*
1785 	 * in6_ifinit() sets nd6_rtrequest to ifa_rtrequest for all ifaddrs.
1786 	 * ifa->ifa_rtrequest = nd6_rtrequest;
1787 	 */
1788 	bzero(&mask6, sizeof(mask6));
1789 	mask6.sin6_len = sizeof(mask6);
1790 	mask6.sin6_addr = pr->ndpr_mask;
1791 	rtflags = (ifa->ifa_flags & ~IFA_RTSELF) | RTF_UP;
1792 
1793 	if(V_rt_add_addr_allfibs) {
1794 		fibnum = 0;
1795 		maxfib = rt_numfibs;
1796 	} else {
1797 		fibnum = ifa->ifa_ifp->if_fib;
1798 		maxfib = fibnum + 1;
1799 	}
1800 	a_failure = 0;
1801 	for (; fibnum < maxfib; fibnum++) {
1802 
1803 		rt = NULL;
1804 		error = in6_rtrequest(RTM_ADD,
1805 		    (struct sockaddr *)&pr->ndpr_prefix, ifa->ifa_addr,
1806 		    (struct sockaddr *)&mask6, rtflags, &rt, fibnum);
1807 		if (error == 0) {
1808 			KASSERT(rt != NULL, ("%s: in6_rtrequest return no "
1809 			    "error(%d) but rt is NULL, pr=%p, ifa=%p", __func__,
1810 			    error, pr, ifa));
1811 
1812 			rnh = rt_tables_get_rnh(rt->rt_fibnum, AF_INET6);
1813 			/* XXX what if rhn == NULL? */
1814 			RIB_WLOCK(rnh);
1815 			RT_LOCK(rt);
1816 			if (rt_setgate(rt, rt_key(rt),
1817 			    (struct sockaddr *)&null_sdl) == 0) {
1818 				struct sockaddr_dl *dl;
1819 
1820 				dl = (struct sockaddr_dl *)rt->rt_gateway;
1821 				dl->sdl_type = rt->rt_ifp->if_type;
1822 				dl->sdl_index = rt->rt_ifp->if_index;
1823 			}
1824 			RIB_WUNLOCK(rnh);
1825 			nd6_rtmsg(RTM_ADD, rt);
1826 			RT_UNLOCK(rt);
1827 			pr->ndpr_stateflags |= NDPRF_ONLINK;
1828 		} else {
1829 			char ip6buf[INET6_ADDRSTRLEN];
1830 			char ip6bufg[INET6_ADDRSTRLEN];
1831 			char ip6bufm[INET6_ADDRSTRLEN];
1832 			struct sockaddr_in6 *sin6;
1833 
1834 			sin6 = (struct sockaddr_in6 *)ifa->ifa_addr;
1835 			nd6log((LOG_ERR, "nd6_prefix_onlink: failed to add "
1836 			    "route for a prefix (%s/%d) on %s, gw=%s, mask=%s, "
1837 			    "flags=%lx errno = %d\n",
1838 			    ip6_sprintf(ip6buf, &pr->ndpr_prefix.sin6_addr),
1839 			    pr->ndpr_plen, if_name(pr->ndpr_ifp),
1840 			    ip6_sprintf(ip6bufg, &sin6->sin6_addr),
1841 			    ip6_sprintf(ip6bufm, &mask6.sin6_addr),
1842 			    rtflags, error));
1843 
1844 			/* Save last error to return, see rtinit(). */
1845 			a_failure = error;
1846 		}
1847 
1848 		if (rt != NULL) {
1849 			RT_LOCK(rt);
1850 			RT_REMREF(rt);
1851 			RT_UNLOCK(rt);
1852 		}
1853 	}
1854 
1855 	/* Return the last error we got. */
1856 	return (a_failure);
1857 }
1858 
1859 int
1860 nd6_prefix_onlink(struct nd_prefix *pr)
1861 {
1862 	struct ifaddr *ifa;
1863 	struct ifnet *ifp = pr->ndpr_ifp;
1864 	struct nd_prefix *opr;
1865 	char ip6buf[INET6_ADDRSTRLEN];
1866 	int error;
1867 
1868 	ND6_ONLINK_LOCK_ASSERT();
1869 	ND6_UNLOCK_ASSERT();
1870 
1871 	if ((pr->ndpr_stateflags & NDPRF_ONLINK) != 0)
1872 		return (EEXIST);
1873 
1874 	/*
1875 	 * Add the interface route associated with the prefix.  Before
1876 	 * installing the route, check if there's the same prefix on another
1877 	 * interface, and the prefix has already installed the interface route.
1878 	 * Although such a configuration is expected to be rare, we explicitly
1879 	 * allow it.
1880 	 */
1881 	ND6_RLOCK();
1882 	LIST_FOREACH(opr, &V_nd_prefix, ndpr_entry) {
1883 		if (opr == pr)
1884 			continue;
1885 
1886 		if ((opr->ndpr_stateflags & NDPRF_ONLINK) == 0)
1887 			continue;
1888 
1889 		if (!V_rt_add_addr_allfibs &&
1890 		    opr->ndpr_ifp->if_fib != pr->ndpr_ifp->if_fib)
1891 			continue;
1892 
1893 		if (opr->ndpr_plen == pr->ndpr_plen &&
1894 		    in6_are_prefix_equal(&pr->ndpr_prefix.sin6_addr,
1895 		    &opr->ndpr_prefix.sin6_addr, pr->ndpr_plen)) {
1896 			ND6_RUNLOCK();
1897 			return (0);
1898 		}
1899 	}
1900 	ND6_RUNLOCK();
1901 
1902 	/*
1903 	 * We prefer link-local addresses as the associated interface address.
1904 	 */
1905 	/* search for a link-local addr */
1906 	ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp,
1907 	    IN6_IFF_NOTREADY | IN6_IFF_ANYCAST);
1908 	if (ifa == NULL) {
1909 		/* XXX: freebsd does not have ifa_ifwithaf */
1910 		IF_ADDR_RLOCK(ifp);
1911 		TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1912 			if (ifa->ifa_addr->sa_family == AF_INET6) {
1913 				ifa_ref(ifa);
1914 				break;
1915 			}
1916 		}
1917 		IF_ADDR_RUNLOCK(ifp);
1918 		/* should we care about ia6_flags? */
1919 	}
1920 	if (ifa == NULL) {
1921 		/*
1922 		 * This can still happen, when, for example, we receive an RA
1923 		 * containing a prefix with the L bit set and the A bit clear,
1924 		 * after removing all IPv6 addresses on the receiving
1925 		 * interface.  This should, of course, be rare though.
1926 		 */
1927 		nd6log((LOG_NOTICE,
1928 		    "nd6_prefix_onlink: failed to find any ifaddr"
1929 		    " to add route for a prefix(%s/%d) on %s\n",
1930 		    ip6_sprintf(ip6buf, &pr->ndpr_prefix.sin6_addr),
1931 		    pr->ndpr_plen, if_name(ifp)));
1932 		return (0);
1933 	}
1934 
1935 	error = nd6_prefix_onlink_rtrequest(pr, ifa);
1936 
1937 	if (ifa != NULL)
1938 		ifa_free(ifa);
1939 
1940 	return (error);
1941 }
1942 
1943 int
1944 nd6_prefix_offlink(struct nd_prefix *pr)
1945 {
1946 	int error = 0;
1947 	struct ifnet *ifp = pr->ndpr_ifp;
1948 	struct nd_prefix *opr;
1949 	struct sockaddr_in6 sa6, mask6;
1950 	struct rtentry *rt;
1951 	char ip6buf[INET6_ADDRSTRLEN];
1952 	uint64_t genid;
1953 	int fibnum, maxfib, a_failure;
1954 
1955 	ND6_ONLINK_LOCK_ASSERT();
1956 	ND6_UNLOCK_ASSERT();
1957 
1958 	if ((pr->ndpr_stateflags & NDPRF_ONLINK) == 0)
1959 		return (EEXIST);
1960 
1961 	bzero(&sa6, sizeof(sa6));
1962 	sa6.sin6_family = AF_INET6;
1963 	sa6.sin6_len = sizeof(sa6);
1964 	bcopy(&pr->ndpr_prefix.sin6_addr, &sa6.sin6_addr,
1965 	    sizeof(struct in6_addr));
1966 	bzero(&mask6, sizeof(mask6));
1967 	mask6.sin6_family = AF_INET6;
1968 	mask6.sin6_len = sizeof(sa6);
1969 	bcopy(&pr->ndpr_mask, &mask6.sin6_addr, sizeof(struct in6_addr));
1970 
1971 	if (V_rt_add_addr_allfibs) {
1972 		fibnum = 0;
1973 		maxfib = rt_numfibs;
1974 	} else {
1975 		fibnum = ifp->if_fib;
1976 		maxfib = fibnum + 1;
1977 	}
1978 
1979 	a_failure = 0;
1980 	for (; fibnum < maxfib; fibnum++) {
1981 		rt = NULL;
1982 		error = in6_rtrequest(RTM_DELETE, (struct sockaddr *)&sa6, NULL,
1983 		    (struct sockaddr *)&mask6, 0, &rt, fibnum);
1984 		if (error == 0) {
1985 			/* report the route deletion to the routing socket. */
1986 			if (rt != NULL)
1987 				nd6_rtmsg(RTM_DELETE, rt);
1988 		} else {
1989 			/* Save last error to return, see rtinit(). */
1990 			a_failure = error;
1991 		}
1992 		if (rt != NULL) {
1993 			RTFREE(rt);
1994 		}
1995 	}
1996 	error = a_failure;
1997 	a_failure = 1;
1998 	if (error == 0) {
1999 		pr->ndpr_stateflags &= ~NDPRF_ONLINK;
2000 
2001 		/*
2002 		 * There might be the same prefix on another interface,
2003 		 * the prefix which could not be on-link just because we have
2004 		 * the interface route (see comments in nd6_prefix_onlink).
2005 		 * If there's one, try to make the prefix on-link on the
2006 		 * interface.
2007 		 */
2008 		ND6_RLOCK();
2009 restart:
2010 		LIST_FOREACH(opr, &V_nd_prefix, ndpr_entry) {
2011 			/*
2012 			 * KAME specific: detached prefixes should not be
2013 			 * on-link.
2014 			 */
2015 			if (opr == pr || (opr->ndpr_stateflags &
2016 			    (NDPRF_ONLINK | NDPRF_DETACHED)) != 0)
2017 				continue;
2018 
2019 			if (opr->ndpr_plen == pr->ndpr_plen &&
2020 			    in6_are_prefix_equal(&pr->ndpr_prefix.sin6_addr,
2021 			    &opr->ndpr_prefix.sin6_addr, pr->ndpr_plen)) {
2022 				int e;
2023 
2024 				genid = V_nd6_list_genid;
2025 				ND6_RUNLOCK();
2026 				if ((e = nd6_prefix_onlink(opr)) != 0) {
2027 					nd6log((LOG_ERR,
2028 					    "nd6_prefix_offlink: failed to "
2029 					    "recover a prefix %s/%d from %s "
2030 					    "to %s (errno = %d)\n",
2031 					    ip6_sprintf(ip6buf,
2032 						&opr->ndpr_prefix.sin6_addr),
2033 					    opr->ndpr_plen, if_name(ifp),
2034 					    if_name(opr->ndpr_ifp), e));
2035 				} else
2036 					a_failure = 0;
2037 				ND6_RLOCK();
2038 				if (genid != V_nd6_list_genid)
2039 					goto restart;
2040 			}
2041 		}
2042 		ND6_RUNLOCK();
2043 	} else {
2044 		/* XXX: can we still set the NDPRF_ONLINK flag? */
2045 		nd6log((LOG_ERR,
2046 		    "nd6_prefix_offlink: failed to delete route: "
2047 		    "%s/%d on %s (errno = %d)\n",
2048 		    ip6_sprintf(ip6buf, &sa6.sin6_addr), pr->ndpr_plen,
2049 		    if_name(ifp), error));
2050 	}
2051 
2052 	if (a_failure)
2053 		lltable_prefix_free(AF_INET6, (struct sockaddr *)&sa6,
2054 		    (struct sockaddr *)&mask6, LLE_STATIC);
2055 
2056 	return (error);
2057 }
2058 
2059 static struct in6_ifaddr *
2060 in6_ifadd(struct nd_prefixctl *pr, int mcast)
2061 {
2062 	struct ifnet *ifp = pr->ndpr_ifp;
2063 	struct ifaddr *ifa;
2064 	struct in6_aliasreq ifra;
2065 	struct in6_ifaddr *ia, *ib;
2066 	int error, plen0;
2067 	struct in6_addr mask;
2068 	int prefixlen = pr->ndpr_plen;
2069 	int updateflags;
2070 	char ip6buf[INET6_ADDRSTRLEN];
2071 
2072 	in6_prefixlen2mask(&mask, prefixlen);
2073 
2074 	/*
2075 	 * find a link-local address (will be interface ID).
2076 	 * Is it really mandatory? Theoretically, a global or a site-local
2077 	 * address can be configured without a link-local address, if we
2078 	 * have a unique interface identifier...
2079 	 *
2080 	 * it is not mandatory to have a link-local address, we can generate
2081 	 * interface identifier on the fly.  we do this because:
2082 	 * (1) it should be the easiest way to find interface identifier.
2083 	 * (2) RFC2462 5.4 suggesting the use of the same interface identifier
2084 	 * for multiple addresses on a single interface, and possible shortcut
2085 	 * of DAD.  we omitted DAD for this reason in the past.
2086 	 * (3) a user can prevent autoconfiguration of global address
2087 	 * by removing link-local address by hand (this is partly because we
2088 	 * don't have other way to control the use of IPv6 on an interface.
2089 	 * this has been our design choice - cf. NRL's "ifconfig auto").
2090 	 * (4) it is easier to manage when an interface has addresses
2091 	 * with the same interface identifier, than to have multiple addresses
2092 	 * with different interface identifiers.
2093 	 */
2094 	ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp, 0); /* 0 is OK? */
2095 	if (ifa)
2096 		ib = (struct in6_ifaddr *)ifa;
2097 	else
2098 		return NULL;
2099 
2100 	/* prefixlen + ifidlen must be equal to 128 */
2101 	plen0 = in6_mask2len(&ib->ia_prefixmask.sin6_addr, NULL);
2102 	if (prefixlen != plen0) {
2103 		ifa_free(ifa);
2104 		nd6log((LOG_INFO, "in6_ifadd: wrong prefixlen for %s "
2105 		    "(prefix=%d ifid=%d)\n",
2106 		    if_name(ifp), prefixlen, 128 - plen0));
2107 		return NULL;
2108 	}
2109 
2110 	/* make ifaddr */
2111 	in6_prepare_ifra(&ifra, &pr->ndpr_prefix.sin6_addr, &mask);
2112 
2113 	IN6_MASK_ADDR(&ifra.ifra_addr.sin6_addr, &mask);
2114 	/* interface ID */
2115 	ifra.ifra_addr.sin6_addr.s6_addr32[0] |=
2116 	    (ib->ia_addr.sin6_addr.s6_addr32[0] & ~mask.s6_addr32[0]);
2117 	ifra.ifra_addr.sin6_addr.s6_addr32[1] |=
2118 	    (ib->ia_addr.sin6_addr.s6_addr32[1] & ~mask.s6_addr32[1]);
2119 	ifra.ifra_addr.sin6_addr.s6_addr32[2] |=
2120 	    (ib->ia_addr.sin6_addr.s6_addr32[2] & ~mask.s6_addr32[2]);
2121 	ifra.ifra_addr.sin6_addr.s6_addr32[3] |=
2122 	    (ib->ia_addr.sin6_addr.s6_addr32[3] & ~mask.s6_addr32[3]);
2123 	ifa_free(ifa);
2124 
2125 	/* lifetimes. */
2126 	ifra.ifra_lifetime.ia6t_vltime = pr->ndpr_vltime;
2127 	ifra.ifra_lifetime.ia6t_pltime = pr->ndpr_pltime;
2128 
2129 	/* XXX: scope zone ID? */
2130 
2131 	ifra.ifra_flags |= IN6_IFF_AUTOCONF; /* obey autoconf */
2132 
2133 	/*
2134 	 * Make sure that we do not have this address already.  This should
2135 	 * usually not happen, but we can still see this case, e.g., if we
2136 	 * have manually configured the exact address to be configured.
2137 	 */
2138 	ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp,
2139 	    &ifra.ifra_addr.sin6_addr);
2140 	if (ifa != NULL) {
2141 		ifa_free(ifa);
2142 		/* this should be rare enough to make an explicit log */
2143 		log(LOG_INFO, "in6_ifadd: %s is already configured\n",
2144 		    ip6_sprintf(ip6buf, &ifra.ifra_addr.sin6_addr));
2145 		return (NULL);
2146 	}
2147 
2148 	/*
2149 	 * Allocate ifaddr structure, link into chain, etc.
2150 	 * If we are going to create a new address upon receiving a multicasted
2151 	 * RA, we need to impose a random delay before starting DAD.
2152 	 * [draft-ietf-ipv6-rfc2462bis-02.txt, Section 5.4.2]
2153 	 */
2154 	updateflags = 0;
2155 	if (mcast)
2156 		updateflags |= IN6_IFAUPDATE_DADDELAY;
2157 	if ((error = in6_update_ifa(ifp, &ifra, NULL, updateflags)) != 0) {
2158 		nd6log((LOG_ERR,
2159 		    "in6_ifadd: failed to make ifaddr %s on %s (errno=%d)\n",
2160 		    ip6_sprintf(ip6buf, &ifra.ifra_addr.sin6_addr),
2161 		    if_name(ifp), error));
2162 		return (NULL);	/* ifaddr must not have been allocated. */
2163 	}
2164 
2165 	ia = in6ifa_ifpwithaddr(ifp, &ifra.ifra_addr.sin6_addr);
2166 	/*
2167 	 * XXXRW: Assumption of non-NULLness here might not be true with
2168 	 * fine-grained locking -- should we validate it?  Or just return
2169 	 * earlier ifa rather than looking it up again?
2170 	 */
2171 	return (ia);		/* this is always non-NULL  and referenced. */
2172 }
2173 
2174 /*
2175  * ia0 - corresponding public address
2176  */
2177 int
2178 in6_tmpifadd(const struct in6_ifaddr *ia0, int forcegen, int delay)
2179 {
2180 	struct ifnet *ifp = ia0->ia_ifa.ifa_ifp;
2181 	struct in6_ifaddr *newia;
2182 	struct in6_aliasreq ifra;
2183 	int error;
2184 	int trylimit = 3;	/* XXX: adhoc value */
2185 	int updateflags;
2186 	u_int32_t randid[2];
2187 	time_t vltime0, pltime0;
2188 
2189 	in6_prepare_ifra(&ifra, &ia0->ia_addr.sin6_addr,
2190 	    &ia0->ia_prefixmask.sin6_addr);
2191 
2192 	ifra.ifra_addr = ia0->ia_addr;	/* XXX: do we need this ? */
2193 	/* clear the old IFID */
2194 	IN6_MASK_ADDR(&ifra.ifra_addr.sin6_addr,
2195 	    &ifra.ifra_prefixmask.sin6_addr);
2196 
2197   again:
2198 	if (in6_get_tmpifid(ifp, (u_int8_t *)randid,
2199 	    (const u_int8_t *)&ia0->ia_addr.sin6_addr.s6_addr[8], forcegen)) {
2200 		nd6log((LOG_NOTICE, "in6_tmpifadd: failed to find a good "
2201 		    "random IFID\n"));
2202 		return (EINVAL);
2203 	}
2204 	ifra.ifra_addr.sin6_addr.s6_addr32[2] |=
2205 	    (randid[0] & ~(ifra.ifra_prefixmask.sin6_addr.s6_addr32[2]));
2206 	ifra.ifra_addr.sin6_addr.s6_addr32[3] |=
2207 	    (randid[1] & ~(ifra.ifra_prefixmask.sin6_addr.s6_addr32[3]));
2208 
2209 	/*
2210 	 * in6_get_tmpifid() quite likely provided a unique interface ID.
2211 	 * However, we may still have a chance to see collision, because
2212 	 * there may be a time lag between generation of the ID and generation
2213 	 * of the address.  So, we'll do one more sanity check.
2214 	 */
2215 
2216 	if (in6_localip(&ifra.ifra_addr.sin6_addr) != 0) {
2217 		if (trylimit-- > 0) {
2218 			forcegen = 1;
2219 			goto again;
2220 		}
2221 
2222 		/* Give up.  Something strange should have happened.  */
2223 		nd6log((LOG_NOTICE, "in6_tmpifadd: failed to "
2224 		    "find a unique random IFID\n"));
2225 		return (EEXIST);
2226 	}
2227 
2228 	/*
2229 	 * The Valid Lifetime is the lower of the Valid Lifetime of the
2230          * public address or TEMP_VALID_LIFETIME.
2231 	 * The Preferred Lifetime is the lower of the Preferred Lifetime
2232          * of the public address or TEMP_PREFERRED_LIFETIME -
2233          * DESYNC_FACTOR.
2234 	 */
2235 	if (ia0->ia6_lifetime.ia6t_vltime != ND6_INFINITE_LIFETIME) {
2236 		vltime0 = IFA6_IS_INVALID(ia0) ? 0 :
2237 		    (ia0->ia6_lifetime.ia6t_vltime -
2238 		    (time_uptime - ia0->ia6_updatetime));
2239 		if (vltime0 > V_ip6_temp_valid_lifetime)
2240 			vltime0 = V_ip6_temp_valid_lifetime;
2241 	} else
2242 		vltime0 = V_ip6_temp_valid_lifetime;
2243 	if (ia0->ia6_lifetime.ia6t_pltime != ND6_INFINITE_LIFETIME) {
2244 		pltime0 = IFA6_IS_DEPRECATED(ia0) ? 0 :
2245 		    (ia0->ia6_lifetime.ia6t_pltime -
2246 		    (time_uptime - ia0->ia6_updatetime));
2247 		if (pltime0 > V_ip6_temp_preferred_lifetime - V_ip6_desync_factor){
2248 			pltime0 = V_ip6_temp_preferred_lifetime -
2249 			    V_ip6_desync_factor;
2250 		}
2251 	} else
2252 		pltime0 = V_ip6_temp_preferred_lifetime - V_ip6_desync_factor;
2253 	ifra.ifra_lifetime.ia6t_vltime = vltime0;
2254 	ifra.ifra_lifetime.ia6t_pltime = pltime0;
2255 
2256 	/*
2257 	 * A temporary address is created only if this calculated Preferred
2258 	 * Lifetime is greater than REGEN_ADVANCE time units.
2259 	 */
2260 	if (ifra.ifra_lifetime.ia6t_pltime <= V_ip6_temp_regen_advance)
2261 		return (0);
2262 
2263 	/* XXX: scope zone ID? */
2264 
2265 	ifra.ifra_flags |= (IN6_IFF_AUTOCONF|IN6_IFF_TEMPORARY);
2266 
2267 	/* allocate ifaddr structure, link into chain, etc. */
2268 	updateflags = 0;
2269 	if (delay)
2270 		updateflags |= IN6_IFAUPDATE_DADDELAY;
2271 	if ((error = in6_update_ifa(ifp, &ifra, NULL, updateflags)) != 0)
2272 		return (error);
2273 
2274 	newia = in6ifa_ifpwithaddr(ifp, &ifra.ifra_addr.sin6_addr);
2275 	if (newia == NULL) {	/* XXX: can it happen? */
2276 		nd6log((LOG_ERR,
2277 		    "in6_tmpifadd: ifa update succeeded, but we got "
2278 		    "no ifaddr\n"));
2279 		return (EINVAL); /* XXX */
2280 	}
2281 	newia->ia6_ndpr = ia0->ia6_ndpr;
2282 	newia->ia6_ndpr->ndpr_addrcnt++;
2283 	ifa_free(&newia->ia_ifa);
2284 
2285 	/*
2286 	 * A newly added address might affect the status of other addresses.
2287 	 * XXX: when the temporary address is generated with a new public
2288 	 * address, the onlink check is redundant.  However, it would be safe
2289 	 * to do the check explicitly everywhere a new address is generated,
2290 	 * and, in fact, we surely need the check when we create a new
2291 	 * temporary address due to deprecation of an old temporary address.
2292 	 */
2293 	pfxlist_onlink_check();
2294 
2295 	return (0);
2296 }
2297 
2298 static int
2299 in6_init_prefix_ltimes(struct nd_prefix *ndpr)
2300 {
2301 	if (ndpr->ndpr_pltime == ND6_INFINITE_LIFETIME)
2302 		ndpr->ndpr_preferred = 0;
2303 	else
2304 		ndpr->ndpr_preferred = time_uptime + ndpr->ndpr_pltime;
2305 	if (ndpr->ndpr_vltime == ND6_INFINITE_LIFETIME)
2306 		ndpr->ndpr_expire = 0;
2307 	else
2308 		ndpr->ndpr_expire = time_uptime + ndpr->ndpr_vltime;
2309 
2310 	return 0;
2311 }
2312 
2313 static void
2314 in6_init_address_ltimes(struct nd_prefix *new, struct in6_addrlifetime *lt6)
2315 {
2316 	/* init ia6t_expire */
2317 	if (lt6->ia6t_vltime == ND6_INFINITE_LIFETIME)
2318 		lt6->ia6t_expire = 0;
2319 	else {
2320 		lt6->ia6t_expire = time_uptime;
2321 		lt6->ia6t_expire += lt6->ia6t_vltime;
2322 	}
2323 
2324 	/* init ia6t_preferred */
2325 	if (lt6->ia6t_pltime == ND6_INFINITE_LIFETIME)
2326 		lt6->ia6t_preferred = 0;
2327 	else {
2328 		lt6->ia6t_preferred = time_uptime;
2329 		lt6->ia6t_preferred += lt6->ia6t_pltime;
2330 	}
2331 }
2332 
2333 /*
2334  * Delete all the routing table entries that use the specified gateway.
2335  * XXX: this function causes search through all entries of routing table, so
2336  * it shouldn't be called when acting as a router.
2337  */
2338 void
2339 rt6_flush(struct in6_addr *gateway, struct ifnet *ifp)
2340 {
2341 
2342 	/* We'll care only link-local addresses */
2343 	if (!IN6_IS_ADDR_LINKLOCAL(gateway))
2344 		return;
2345 
2346 	/* XXX Do we really need to walk any but the default FIB? */
2347 	rt_foreach_fib_walk_del(AF_INET6, rt6_deleteroute, (void *)gateway);
2348 }
2349 
2350 static int
2351 rt6_deleteroute(const struct rtentry *rt, void *arg)
2352 {
2353 #define SIN6(s)	((struct sockaddr_in6 *)s)
2354 	struct in6_addr *gate = (struct in6_addr *)arg;
2355 
2356 	if (rt->rt_gateway == NULL || rt->rt_gateway->sa_family != AF_INET6)
2357 		return (0);
2358 
2359 	if (!IN6_ARE_ADDR_EQUAL(gate, &SIN6(rt->rt_gateway)->sin6_addr)) {
2360 		return (0);
2361 	}
2362 
2363 	/*
2364 	 * Do not delete a static route.
2365 	 * XXX: this seems to be a bit ad-hoc. Should we consider the
2366 	 * 'cloned' bit instead?
2367 	 */
2368 	if ((rt->rt_flags & RTF_STATIC) != 0)
2369 		return (0);
2370 
2371 	/*
2372 	 * We delete only host route. This means, in particular, we don't
2373 	 * delete default route.
2374 	 */
2375 	if ((rt->rt_flags & RTF_HOST) == 0)
2376 		return (0);
2377 
2378 	return (1);
2379 #undef SIN6
2380 }
2381 
2382 int
2383 nd6_setdefaultiface(int ifindex)
2384 {
2385 	int error = 0;
2386 
2387 	if (ifindex < 0 || V_if_index < ifindex)
2388 		return (EINVAL);
2389 	if (ifindex != 0 && !ifnet_byindex(ifindex))
2390 		return (EINVAL);
2391 
2392 	if (V_nd6_defifindex != ifindex) {
2393 		V_nd6_defifindex = ifindex;
2394 		if (V_nd6_defifindex > 0)
2395 			V_nd6_defifp = ifnet_byindex(V_nd6_defifindex);
2396 		else
2397 			V_nd6_defifp = NULL;
2398 
2399 		/*
2400 		 * Our current implementation assumes one-to-one maping between
2401 		 * interfaces and links, so it would be natural to use the
2402 		 * default interface as the default link.
2403 		 */
2404 		scope6_setdefault(V_nd6_defifp);
2405 	}
2406 
2407 	return (error);
2408 }
2409