1 /* $NetBSD: nd6_rtr.c,v 1.76 2008/10/24 21:30:34 dyoung Exp $ */
2 /* $KAME: nd6_rtr.c,v 1.95 2001/02/07 08:09:47 itojun 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 <sys/cdefs.h>
34 __KERNEL_RCSID(0, "$NetBSD: nd6_rtr.c,v 1.76 2008/10/24 21:30:34 dyoung Exp $");
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/ioctl.h>
46 #include <sys/syslog.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/icmp6_private.h>
62 #include <netinet6/scope6_var.h>
63
64 #include <net/net_osdep.h>
65
66 static int rtpref(struct nd_defrouter *);
67 static struct nd_defrouter *defrtrlist_update(struct nd_defrouter *);
68 static int prelist_update(struct nd_prefixctl *, struct nd_defrouter *,
69 struct mbuf *, int);
70 static struct in6_ifaddr *in6_ifadd(struct nd_prefixctl *, int);
71 static struct nd_pfxrouter *pfxrtr_lookup(struct nd_prefix *,
72 struct nd_defrouter *);
73 static void pfxrtr_add(struct nd_prefix *, struct nd_defrouter *);
74 static void pfxrtr_del(struct nd_pfxrouter *);
75 static struct nd_pfxrouter *find_pfxlist_reachable_router
76 (struct nd_prefix *);
77 static void defrouter_delreq(struct nd_defrouter *);
78 static void nd6_rtmsg(int, struct rtentry *);
79
80 static int in6_init_prefix_ltimes(struct nd_prefix *);
81 static void in6_init_address_ltimes(struct nd_prefix *ndpr,
82 struct in6_addrlifetime *lt6);
83
84 static int rt6_deleteroute(struct rtentry *, void *);
85
86 extern int nd6_recalc_reachtm_interval;
87
88 static struct ifnet *nd6_defifp;
89 int nd6_defifindex;
90
91 int ip6_use_tempaddr = 0;
92
93 int ip6_desync_factor;
94 u_int32_t ip6_temp_preferred_lifetime = DEF_TEMP_PREFERRED_LIFETIME;
95 u_int32_t ip6_temp_valid_lifetime = DEF_TEMP_VALID_LIFETIME;
96 int ip6_temp_regen_advance = TEMPADDR_REGEN_ADVANCE;
97
98 /* RTPREF_MEDIUM has to be 0! */
99 #define RTPREF_HIGH 1
100 #define RTPREF_MEDIUM 0
101 #define RTPREF_LOW (-1)
102 #define RTPREF_RESERVED (-2)
103 #define RTPREF_INVALID (-3) /* internal */
104
105 /*
106 * Receive Router Solicitation Message - just for routers.
107 * Router solicitation/advertisement is mostly managed by userland program
108 * (rtadvd) so here we have no function like nd6_ra_output().
109 *
110 * Based on RFC 2461
111 */
112 void
113 nd6_rs_input(struct mbuf *m, int off, int icmp6len)
114 {
115 struct ifnet *ifp = m->m_pkthdr.rcvif;
116 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
117 struct nd_router_solicit *nd_rs;
118 struct in6_addr saddr6 = ip6->ip6_src;
119 char *lladdr = NULL;
120 int lladdrlen = 0;
121 union nd_opts ndopts;
122
123 /* If I'm not a router, ignore it. */
124 if (ip6_accept_rtadv != 0 || !ip6_forwarding)
125 goto freeit;
126
127 /* Sanity checks */
128 if (ip6->ip6_hlim != 255) {
129 nd6log((LOG_ERR,
130 "nd6_rs_input: invalid hlim (%d) from %s to %s on %s\n",
131 ip6->ip6_hlim, ip6_sprintf(&ip6->ip6_src),
132 ip6_sprintf(&ip6->ip6_dst), if_name(ifp)));
133 goto bad;
134 }
135
136 /*
137 * Don't update the neighbor cache, if src = ::.
138 * This indicates that the src has no IP address assigned yet.
139 */
140 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6))
141 goto freeit;
142
143 IP6_EXTHDR_GET(nd_rs, struct nd_router_solicit *, m, off, icmp6len);
144 if (nd_rs == NULL) {
145 ICMP6_STATINC(ICMP6_STAT_TOOSHORT);
146 return;
147 }
148
149 icmp6len -= sizeof(*nd_rs);
150 nd6_option_init(nd_rs + 1, icmp6len, &ndopts);
151 if (nd6_options(&ndopts) < 0) {
152 nd6log((LOG_INFO,
153 "nd6_rs_input: invalid ND option, ignored\n"));
154 /* nd6_options have incremented stats */
155 goto freeit;
156 }
157
158 if (ndopts.nd_opts_src_lladdr) {
159 lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1);
160 lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3;
161 }
162
163 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
164 nd6log((LOG_INFO,
165 "nd6_rs_input: lladdrlen mismatch for %s "
166 "(if %d, RS packet %d)\n",
167 ip6_sprintf(&saddr6), ifp->if_addrlen, lladdrlen - 2));
168 goto bad;
169 }
170
171 nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, ND_ROUTER_SOLICIT, 0);
172
173 freeit:
174 m_freem(m);
175 return;
176
177 bad:
178 ICMP6_STATINC(ICMP6_STAT_BADRS);
179 m_freem(m);
180 }
181
182 /*
183 * Receive Router Advertisement Message.
184 *
185 * Based on RFC 2461
186 * TODO: on-link bit on prefix information
187 * TODO: ND_RA_FLAG_{OTHER,MANAGED} processing
188 */
189 void
190 nd6_ra_input(struct mbuf *m, int off, int icmp6len)
191 {
192 struct ifnet *ifp = m->m_pkthdr.rcvif;
193 struct nd_ifinfo *ndi = ND_IFINFO(ifp);
194 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
195 struct nd_router_advert *nd_ra;
196 struct in6_addr saddr6 = ip6->ip6_src;
197 #if 0
198 struct in6_addr daddr6 = ip6->ip6_dst;
199 int flags; /* = nd_ra->nd_ra_flags_reserved; */
200 int is_managed = ((flags & ND_RA_FLAG_MANAGED) != 0);
201 int is_other = ((flags & ND_RA_FLAG_OTHER) != 0);
202 #endif
203 int mcast = 0;
204 union nd_opts ndopts;
205 struct nd_defrouter *dr;
206
207 /*
208 * We only accept RAs only when
209 * the system-wide variable allows the acceptance, and
210 * per-interface variable allows RAs on the receiving interface.
211 */
212 if (ip6_accept_rtadv == 0)
213 goto freeit;
214 if (!(ndi->flags & ND6_IFF_ACCEPT_RTADV))
215 goto freeit;
216
217 if (ip6->ip6_hlim != 255) {
218 nd6log((LOG_ERR,
219 "nd6_ra_input: invalid hlim (%d) from %s to %s on %s\n",
220 ip6->ip6_hlim, ip6_sprintf(&ip6->ip6_src),
221 ip6_sprintf(&ip6->ip6_dst), if_name(ifp)));
222 goto bad;
223 }
224
225 if (!IN6_IS_ADDR_LINKLOCAL(&saddr6)) {
226 nd6log((LOG_ERR,
227 "nd6_ra_input: src %s is not link-local\n",
228 ip6_sprintf(&saddr6)));
229 goto bad;
230 }
231
232 IP6_EXTHDR_GET(nd_ra, struct nd_router_advert *, m, off, icmp6len);
233 if (nd_ra == NULL) {
234 ICMP6_STATINC(ICMP6_STAT_TOOSHORT);
235 return;
236 }
237
238 icmp6len -= sizeof(*nd_ra);
239 nd6_option_init(nd_ra + 1, icmp6len, &ndopts);
240 if (nd6_options(&ndopts) < 0) {
241 nd6log((LOG_INFO,
242 "nd6_ra_input: invalid ND option, ignored\n"));
243 /* nd6_options have incremented stats */
244 goto freeit;
245 }
246
247 {
248 struct nd_defrouter drtr;
249 u_int32_t advreachable = nd_ra->nd_ra_reachable;
250
251 /* remember if this is a multicasted advertisement */
252 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst))
253 mcast = 1;
254
255 memset(&drtr, 0, sizeof(drtr));
256 drtr.rtaddr = saddr6;
257 drtr.flags = nd_ra->nd_ra_flags_reserved;
258 drtr.rtlifetime = ntohs(nd_ra->nd_ra_router_lifetime);
259 drtr.expire = time_second + drtr.rtlifetime;
260 drtr.ifp = ifp;
261 /* unspecified or not? (RFC 2461 6.3.4) */
262 if (advreachable) {
263 NTOHL(advreachable);
264 if (advreachable <= MAX_REACHABLE_TIME &&
265 ndi->basereachable != advreachable) {
266 ndi->basereachable = advreachable;
267 ndi->reachable = ND_COMPUTE_RTIME(ndi->basereachable);
268 ndi->recalctm = nd6_recalc_reachtm_interval; /* reset */
269 }
270 }
271 if (nd_ra->nd_ra_retransmit)
272 ndi->retrans = ntohl(nd_ra->nd_ra_retransmit);
273 if (nd_ra->nd_ra_curhoplimit)
274 ndi->chlim = nd_ra->nd_ra_curhoplimit;
275 dr = defrtrlist_update(&drtr);
276 }
277
278 /*
279 * prefix
280 */
281 if (ndopts.nd_opts_pi) {
282 struct nd_opt_hdr *pt;
283 struct nd_opt_prefix_info *pi = NULL;
284 struct nd_prefixctl pr;
285
286 for (pt = (struct nd_opt_hdr *)ndopts.nd_opts_pi;
287 pt <= (struct nd_opt_hdr *)ndopts.nd_opts_pi_end;
288 pt = (struct nd_opt_hdr *)((char *)pt +
289 (pt->nd_opt_len << 3))) {
290 if (pt->nd_opt_type != ND_OPT_PREFIX_INFORMATION)
291 continue;
292 pi = (struct nd_opt_prefix_info *)pt;
293
294 if (pi->nd_opt_pi_len != 4) {
295 nd6log((LOG_INFO,
296 "nd6_ra_input: invalid option "
297 "len %d for prefix information option, "
298 "ignored\n", pi->nd_opt_pi_len));
299 continue;
300 }
301
302 if (128 < pi->nd_opt_pi_prefix_len) {
303 nd6log((LOG_INFO,
304 "nd6_ra_input: invalid prefix "
305 "len %d for prefix information option, "
306 "ignored\n", pi->nd_opt_pi_prefix_len));
307 continue;
308 }
309
310 if (IN6_IS_ADDR_MULTICAST(&pi->nd_opt_pi_prefix)
311 || IN6_IS_ADDR_LINKLOCAL(&pi->nd_opt_pi_prefix)) {
312 nd6log((LOG_INFO,
313 "nd6_ra_input: invalid prefix "
314 "%s, ignored\n",
315 ip6_sprintf(&pi->nd_opt_pi_prefix)));
316 continue;
317 }
318
319 bzero(&pr, sizeof(pr));
320 sockaddr_in6_init(&pr.ndpr_prefix,
321 &pi->nd_opt_pi_prefix, 0, 0, 0);
322 pr.ndpr_ifp = (struct ifnet *)m->m_pkthdr.rcvif;
323
324 pr.ndpr_raf_onlink = (pi->nd_opt_pi_flags_reserved &
325 ND_OPT_PI_FLAG_ONLINK) ? 1 : 0;
326 pr.ndpr_raf_auto = (pi->nd_opt_pi_flags_reserved &
327 ND_OPT_PI_FLAG_AUTO) ? 1 : 0;
328 pr.ndpr_plen = pi->nd_opt_pi_prefix_len;
329 pr.ndpr_vltime = ntohl(pi->nd_opt_pi_valid_time);
330 pr.ndpr_pltime = ntohl(pi->nd_opt_pi_preferred_time);
331
332 (void)prelist_update(&pr, dr, m, mcast);
333 }
334 }
335
336 /*
337 * MTU
338 */
339 if (ndopts.nd_opts_mtu && ndopts.nd_opts_mtu->nd_opt_mtu_len == 1) {
340 u_long mtu;
341 u_long maxmtu;
342
343 mtu = ntohl(ndopts.nd_opts_mtu->nd_opt_mtu_mtu);
344
345 /* lower bound */
346 if (mtu < IPV6_MMTU) {
347 nd6log((LOG_INFO, "nd6_ra_input: bogus mtu option "
348 "mtu=%lu sent from %s, ignoring\n",
349 mtu, ip6_sprintf(&ip6->ip6_src)));
350 goto skip;
351 }
352
353 /* upper bound */
354 maxmtu = (ndi->maxmtu && ndi->maxmtu < ifp->if_mtu)
355 ? ndi->maxmtu : ifp->if_mtu;
356 if (mtu <= maxmtu) {
357 int change = (ndi->linkmtu != mtu);
358
359 ndi->linkmtu = mtu;
360 if (change) /* in6_maxmtu may change */
361 in6_setmaxmtu();
362 } else {
363 nd6log((LOG_INFO, "nd6_ra_input: bogus mtu "
364 "mtu=%lu sent from %s; "
365 "exceeds maxmtu %lu, ignoring\n",
366 mtu, ip6_sprintf(&ip6->ip6_src), maxmtu));
367 }
368 }
369
370 skip:
371
372 /*
373 * Source link layer address
374 */
375 {
376 char *lladdr = NULL;
377 int lladdrlen = 0;
378
379 if (ndopts.nd_opts_src_lladdr) {
380 lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1);
381 lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3;
382 }
383
384 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
385 nd6log((LOG_INFO,
386 "nd6_ra_input: lladdrlen mismatch for %s "
387 "(if %d, RA packet %d)\n", ip6_sprintf(&saddr6),
388 ifp->if_addrlen, lladdrlen - 2));
389 goto bad;
390 }
391
392 nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, ND_ROUTER_ADVERT, 0);
393
394 /*
395 * Installing a link-layer address might change the state of the
396 * router's neighbor cache, which might also affect our on-link
397 * detection of adveritsed prefixes.
398 */
399 pfxlist_onlink_check();
400 }
401
402 freeit:
403 m_freem(m);
404 return;
405
406 bad:
407 ICMP6_STATINC(ICMP6_STAT_BADRA);
408 m_freem(m);
409 }
410
411 /*
412 * default router list processing sub routines
413 */
414
415 /* tell the change to user processes watching the routing socket. */
416 static void
417 nd6_rtmsg(int cmd, struct rtentry *rt)
418 {
419 struct rt_addrinfo info;
420
421 bzero((void *)&info, sizeof(info));
422 info.rti_info[RTAX_DST] = rt_getkey(rt);
423 info.rti_info[RTAX_GATEWAY] = rt->rt_gateway;
424 info.rti_info[RTAX_NETMASK] = rt_mask(rt);
425 if (rt->rt_ifp) {
426 info.rti_info[RTAX_IFP] = rt->rt_ifp->if_dl->ifa_addr;
427 info.rti_info[RTAX_IFA] = rt->rt_ifa->ifa_addr;
428 }
429
430 rt_missmsg(cmd, &info, rt->rt_flags, 0);
431 }
432
433 void
434 defrouter_addreq(struct nd_defrouter *new)
435 {
436 union {
437 struct sockaddr_in6 sin6;
438 struct sockaddr sa;
439 } def, mask, gate;
440 struct rtentry *newrt = NULL;
441 int s;
442 int error;
443
444 memset(&def, 0, sizeof(def));
445 memset(&mask, 0, sizeof(mask));
446 memset(&gate, 0,sizeof(gate)); /* for safety */
447
448 def.sin6.sin6_len = mask.sin6.sin6_len = gate.sin6.sin6_len =
449 sizeof(struct sockaddr_in6);
450 def.sin6.sin6_family = mask.sin6.sin6_family = gate.sin6.sin6_family = AF_INET6;
451 gate.sin6.sin6_addr = new->rtaddr;
452 #ifndef SCOPEDROUTING
453 gate.sin6.sin6_scope_id = 0; /* XXX */
454 #endif
455
456 s = splsoftnet();
457 error = rtrequest(RTM_ADD, &def.sa, &gate.sa, &mask.sa,
458 RTF_GATEWAY, &newrt);
459 if (newrt) {
460 nd6_rtmsg(RTM_ADD, newrt); /* tell user process */
461 newrt->rt_refcnt--;
462 }
463 if (error == 0)
464 new->installed = 1;
465 splx(s);
466 return;
467 }
468
469 struct nd_defrouter *
470 defrouter_lookup(const struct in6_addr *addr, struct ifnet *ifp)
471 {
472 struct nd_defrouter *dr;
473
474 TAILQ_FOREACH(dr, &nd_defrouter, dr_entry) {
475 if (dr->ifp == ifp && IN6_ARE_ADDR_EQUAL(addr, &dr->rtaddr))
476 break;
477 }
478
479 return dr; /* search failed */
480 }
481
482 void
483 defrtrlist_del(struct nd_defrouter *dr)
484 {
485 struct nd_defrouter *deldr = NULL;
486 struct nd_prefix *pr;
487
488 /*
489 * Flush all the routing table entries that use the router
490 * as a next hop.
491 */
492 if (!ip6_forwarding && ip6_accept_rtadv) /* XXX: better condition? */
493 rt6_flush(&dr->rtaddr, dr->ifp);
494
495 if (dr->installed) {
496 deldr = dr;
497 defrouter_delreq(dr);
498 }
499 TAILQ_REMOVE(&nd_defrouter, dr, dr_entry);
500
501 /*
502 * Also delete all the pointers to the router in each prefix lists.
503 */
504 LIST_FOREACH(pr, &nd_prefix, ndpr_entry) {
505 struct nd_pfxrouter *pfxrtr;
506 if ((pfxrtr = pfxrtr_lookup(pr, dr)) != NULL)
507 pfxrtr_del(pfxrtr);
508 }
509 pfxlist_onlink_check();
510
511 /*
512 * If the router is the primary one, choose a new one.
513 * Note that defrouter_select() will remove the current gateway
514 * from the routing table.
515 */
516 if (deldr)
517 defrouter_select();
518
519 free(dr, M_IP6NDP);
520 }
521
522 /*
523 * Remove the default route for a given router.
524 * This is just a subroutine function for defrouter_select(), and should
525 * not be called from anywhere else.
526 */
527 static void
528 defrouter_delreq(struct nd_defrouter *dr)
529 {
530 union {
531 struct sockaddr_in6 sin6;
532 struct sockaddr sa;
533 } def, mask, gw;
534 struct rtentry *oldrt = NULL;
535
536 #ifdef DIAGNOSTIC
537 if (dr == NULL)
538 panic("dr == NULL in defrouter_delreq");
539 #endif
540
541 memset(&def, 0, sizeof(def));
542 memset(&mask, 0, sizeof(mask));
543 memset(&gw, 0, sizeof(gw)); /* for safety */
544
545 def.sin6.sin6_len = mask.sin6.sin6_len = gw.sin6.sin6_len =
546 sizeof(struct sockaddr_in6);
547 def.sin6.sin6_family = mask.sin6.sin6_family = gw.sin6.sin6_family = AF_INET6;
548 gw.sin6.sin6_addr = dr->rtaddr;
549 #ifndef SCOPEDROUTING
550 gw.sin6.sin6_scope_id = 0; /* XXX */
551 #endif
552
553 rtrequest(RTM_DELETE, &def.sa, &gw.sa, &mask.sa, RTF_GATEWAY, &oldrt);
554 if (oldrt) {
555 nd6_rtmsg(RTM_DELETE, oldrt);
556 if (oldrt->rt_refcnt <= 0) {
557 /*
558 * XXX: borrowed from the RTM_DELETE case of
559 * rtrequest().
560 */
561 oldrt->rt_refcnt++;
562 rtfree(oldrt);
563 }
564 }
565
566 dr->installed = 0;
567 }
568
569 /*
570 * remove all default routes from default router list
571 */
572 void
573 defrouter_reset(void)
574 {
575 struct nd_defrouter *dr;
576
577 for (dr = TAILQ_FIRST(&nd_defrouter); dr;
578 dr = TAILQ_NEXT(dr, dr_entry))
579 defrouter_delreq(dr);
580
581 /*
582 * XXX should we also nuke any default routers in the kernel, by
583 * going through them by rtalloc1()?
584 */
585 }
586
587 /*
588 * Default Router Selection according to Section 6.3.6 of RFC 2461 and
589 * draft-ietf-ipngwg-router-selection:
590 * 1) Routers that are reachable or probably reachable should be preferred.
591 * If we have more than one (probably) reachable router, prefer ones
592 * with the highest router preference.
593 * 2) When no routers on the list are known to be reachable or
594 * probably reachable, routers SHOULD be selected in a round-robin
595 * fashion, regardless of router preference values.
596 * 3) If the Default Router List is empty, assume that all
597 * destinations are on-link.
598 *
599 * We assume nd_defrouter is sorted by router preference value.
600 * Since the code below covers both with and without router preference cases,
601 * we do not need to classify the cases by ifdef.
602 *
603 * At this moment, we do not try to install more than one default router,
604 * even when the multipath routing is available, because we're not sure about
605 * the benefits for stub hosts comparing to the risk of making the code
606 * complicated and the possibility of introducing bugs.
607 */
608 void
609 defrouter_select(void)
610 {
611 int s = splsoftnet();
612 struct nd_defrouter *dr, *selected_dr = NULL, *installed_dr = NULL;
613 struct rtentry *rt = NULL;
614 struct llinfo_nd6 *ln = NULL;
615
616 /*
617 * This function should be called only when acting as an autoconfigured
618 * host. Although the remaining part of this function is not effective
619 * if the node is not an autoconfigured host, we explicitly exclude
620 * such cases here for safety.
621 */
622 if (ip6_forwarding || !ip6_accept_rtadv) {
623 nd6log((LOG_WARNING,
624 "defrouter_select: called unexpectedly (forwarding=%d, "
625 "accept_rtadv=%d)\n", ip6_forwarding, ip6_accept_rtadv));
626 splx(s);
627 return;
628 }
629
630 /*
631 * Let's handle easy case (3) first:
632 * If default router list is empty, there's nothing to be done.
633 */
634 if (!TAILQ_FIRST(&nd_defrouter)) {
635 splx(s);
636 return;
637 }
638
639 /*
640 * Search for a (probably) reachable router from the list.
641 * We just pick up the first reachable one (if any), assuming that
642 * the ordering rule of the list described in defrtrlist_update().
643 */
644 for (dr = TAILQ_FIRST(&nd_defrouter); dr;
645 dr = TAILQ_NEXT(dr, dr_entry)) {
646 if (selected_dr == NULL &&
647 (rt = nd6_lookup(&dr->rtaddr, 0, dr->ifp)) != NULL &&
648 (ln = (struct llinfo_nd6 *)rt->rt_llinfo) != NULL &&
649 ND6_IS_LLINFO_PROBREACH(ln)) {
650 selected_dr = dr;
651 }
652
653 if (dr->installed && !installed_dr)
654 installed_dr = dr;
655 else if (dr->installed && installed_dr) {
656 /* this should not happen. warn for diagnosis. */
657 log(LOG_ERR, "defrouter_select: more than one router"
658 " is installed\n");
659 }
660 }
661 /*
662 * If none of the default routers was found to be reachable,
663 * round-robin the list regardless of preference.
664 * Otherwise, if we have an installed router, check if the selected
665 * (reachable) router should really be preferred to the installed one.
666 * We only prefer the new router when the old one is not reachable
667 * or when the new one has a really higher preference value.
668 */
669 if (selected_dr == NULL) {
670 if (installed_dr == NULL || !TAILQ_NEXT(installed_dr, dr_entry))
671 selected_dr = TAILQ_FIRST(&nd_defrouter);
672 else
673 selected_dr = TAILQ_NEXT(installed_dr, dr_entry);
674 } else if (installed_dr &&
675 (rt = nd6_lookup(&installed_dr->rtaddr, 0, installed_dr->ifp)) &&
676 (ln = (struct llinfo_nd6 *)rt->rt_llinfo) &&
677 ND6_IS_LLINFO_PROBREACH(ln) &&
678 rtpref(selected_dr) <= rtpref(installed_dr)) {
679 selected_dr = installed_dr;
680 }
681
682 /*
683 * If the selected router is different than the installed one,
684 * remove the installed router and install the selected one.
685 * Note that the selected router is never NULL here.
686 */
687 if (installed_dr != selected_dr) {
688 if (installed_dr)
689 defrouter_delreq(installed_dr);
690 defrouter_addreq(selected_dr);
691 }
692
693 splx(s);
694 return;
695 }
696
697 /*
698 * for default router selection
699 * regards router-preference field as a 2-bit signed integer
700 */
701 static int
702 rtpref(struct nd_defrouter *dr)
703 {
704 switch (dr->flags & ND_RA_FLAG_RTPREF_MASK) {
705 case ND_RA_FLAG_RTPREF_HIGH:
706 return (RTPREF_HIGH);
707 case ND_RA_FLAG_RTPREF_MEDIUM:
708 case ND_RA_FLAG_RTPREF_RSV:
709 return (RTPREF_MEDIUM);
710 case ND_RA_FLAG_RTPREF_LOW:
711 return (RTPREF_LOW);
712 default:
713 /*
714 * This case should never happen. If it did, it would mean a
715 * serious bug of kernel internal. We thus always bark here.
716 * Or, can we even panic?
717 */
718 log(LOG_ERR, "rtpref: impossible RA flag %x\n", dr->flags);
719 return (RTPREF_INVALID);
720 }
721 /* NOTREACHED */
722 }
723
724 static struct nd_defrouter *
725 defrtrlist_update(struct nd_defrouter *new)
726 {
727 struct nd_defrouter *dr, *n;
728 int s = splsoftnet();
729
730 if ((dr = defrouter_lookup(&new->rtaddr, new->ifp)) != NULL) {
731 /* entry exists */
732 if (new->rtlifetime == 0) {
733 defrtrlist_del(dr);
734 dr = NULL;
735 } else {
736 int oldpref = rtpref(dr);
737
738 /* override */
739 dr->flags = new->flags; /* xxx flag check */
740 dr->rtlifetime = new->rtlifetime;
741 dr->expire = new->expire;
742
743 /*
744 * If the preference does not change, there's no need
745 * to sort the entries.
746 */
747 if (rtpref(new) == oldpref) {
748 splx(s);
749 return (dr);
750 }
751
752 /*
753 * preferred router may be changed, so relocate
754 * this router.
755 * XXX: calling TAILQ_REMOVE directly is a bad manner.
756 * However, since defrtrlist_del() has many side
757 * effects, we intentionally do so here.
758 * defrouter_select() below will handle routing
759 * changes later.
760 */
761 TAILQ_REMOVE(&nd_defrouter, dr, dr_entry);
762 n = dr;
763 goto insert;
764 }
765 splx(s);
766 return (dr);
767 }
768
769 /* entry does not exist */
770 if (new->rtlifetime == 0) {
771 splx(s);
772 return (NULL);
773 }
774
775 n = (struct nd_defrouter *)malloc(sizeof(*n), M_IP6NDP, M_NOWAIT);
776 if (n == NULL) {
777 splx(s);
778 return (NULL);
779 }
780 bzero(n, sizeof(*n));
781 *n = *new;
782
783 insert:
784 /*
785 * Insert the new router in the Default Router List;
786 * The Default Router List should be in the descending order
787 * of router-preferece. Routers with the same preference are
788 * sorted in the arriving time order.
789 */
790
791 /* insert at the end of the group */
792 for (dr = TAILQ_FIRST(&nd_defrouter); dr;
793 dr = TAILQ_NEXT(dr, dr_entry)) {
794 if (rtpref(n) > rtpref(dr))
795 break;
796 }
797 if (dr)
798 TAILQ_INSERT_BEFORE(dr, n, dr_entry);
799 else
800 TAILQ_INSERT_TAIL(&nd_defrouter, n, dr_entry);
801
802 defrouter_select();
803
804 splx(s);
805
806 return (n);
807 }
808
809 static struct nd_pfxrouter *
810 pfxrtr_lookup(struct nd_prefix *pr, struct nd_defrouter *dr)
811 {
812 struct nd_pfxrouter *search;
813
814 LIST_FOREACH(search, &pr->ndpr_advrtrs, pfr_entry) {
815 if (search->router == dr)
816 break;
817 }
818
819 return (search);
820 }
821
822 static void
823 pfxrtr_add(struct nd_prefix *pr, struct nd_defrouter *dr)
824 {
825 struct nd_pfxrouter *new;
826
827 new = (struct nd_pfxrouter *)malloc(sizeof(*new), M_IP6NDP, M_NOWAIT);
828 if (new == NULL)
829 return;
830 bzero(new, sizeof(*new));
831 new->router = dr;
832
833 LIST_INSERT_HEAD(&pr->ndpr_advrtrs, new, pfr_entry);
834
835 pfxlist_onlink_check();
836 }
837
838 static void
839 pfxrtr_del(struct nd_pfxrouter *pfr)
840 {
841 LIST_REMOVE(pfr, pfr_entry);
842 free(pfr, M_IP6NDP);
843 }
844
845 struct nd_prefix *
846 nd6_prefix_lookup(struct nd_prefixctl *key)
847 {
848 struct nd_prefix *search;
849
850 LIST_FOREACH(search, &nd_prefix, ndpr_entry) {
851 if (key->ndpr_ifp == search->ndpr_ifp &&
852 key->ndpr_plen == search->ndpr_plen &&
853 in6_are_prefix_equal(&key->ndpr_prefix.sin6_addr,
854 &search->ndpr_prefix.sin6_addr, key->ndpr_plen)) {
855 break;
856 }
857 }
858
859 return (search);
860 }
861
862 int
863 nd6_prelist_add(struct nd_prefixctl *pr, struct nd_defrouter *dr,
864 struct nd_prefix **newp)
865 {
866 struct nd_prefix *new = NULL;
867 int i, s;
868 int error;
869
870 error = 0;
871 new = (struct nd_prefix *)malloc(sizeof(*new), M_IP6NDP, M_NOWAIT);
872 if (new == NULL)
873 return ENOMEM;
874 bzero(new, sizeof(*new));
875 new->ndpr_ifp = pr->ndpr_ifp;
876 new->ndpr_prefix = pr->ndpr_prefix;
877 new->ndpr_plen = pr->ndpr_plen;
878 new->ndpr_vltime = pr->ndpr_vltime;
879 new->ndpr_pltime = pr->ndpr_pltime;
880 new->ndpr_flags = pr->ndpr_flags;
881 if ((error = in6_init_prefix_ltimes(new)) != 0) {
882 free(new, M_IP6NDP);
883 return(error);
884 }
885 new->ndpr_lastupdate = time_second;
886 if (newp != NULL)
887 *newp = new;
888
889 /* initialization */
890 LIST_INIT(&new->ndpr_advrtrs);
891 in6_prefixlen2mask(&new->ndpr_mask, new->ndpr_plen);
892 /* make prefix in the canonical form */
893 for (i = 0; i < 4; i++)
894 new->ndpr_prefix.sin6_addr.s6_addr32[i] &=
895 new->ndpr_mask.s6_addr32[i];
896
897 s = splsoftnet();
898 /* link ndpr_entry to nd_prefix list */
899 LIST_INSERT_HEAD(&nd_prefix, new, ndpr_entry);
900 splx(s);
901
902 /* ND_OPT_PI_FLAG_ONLINK processing */
903 if (new->ndpr_raf_onlink) {
904 int e;
905
906 if ((e = nd6_prefix_onlink(new)) != 0) {
907 nd6log((LOG_ERR, "nd6_prelist_add: failed to make "
908 "the prefix %s/%d on-link on %s (errno=%d)\n",
909 ip6_sprintf(&pr->ndpr_prefix.sin6_addr),
910 pr->ndpr_plen, if_name(pr->ndpr_ifp), e));
911 /* proceed anyway. XXX: is it correct? */
912 }
913 }
914
915 if (dr)
916 pfxrtr_add(new, dr);
917
918 return 0;
919 }
920
921 void
922 prelist_remove(struct nd_prefix *pr)
923 {
924 struct nd_pfxrouter *pfr, *next;
925 int e, s;
926
927 /* make sure to invalidate the prefix until it is really freed. */
928 pr->ndpr_vltime = 0;
929 pr->ndpr_pltime = 0;
930 #if 0
931 /*
932 * Though these flags are now meaningless, we'd rather keep the value
933 * not to confuse users when executing "ndp -p".
934 */
935 pr->ndpr_raf_onlink = 0;
936 pr->ndpr_raf_auto = 0;
937 #endif
938 if ((pr->ndpr_stateflags & NDPRF_ONLINK) != 0 &&
939 (e = nd6_prefix_offlink(pr)) != 0) {
940 nd6log((LOG_ERR, "prelist_remove: failed to make %s/%d offlink "
941 "on %s, errno=%d\n",
942 ip6_sprintf(&pr->ndpr_prefix.sin6_addr),
943 pr->ndpr_plen, if_name(pr->ndpr_ifp), e));
944 /* what should we do? */
945 }
946
947 if (pr->ndpr_refcnt > 0)
948 return; /* notice here? */
949
950 s = splsoftnet();
951 /* unlink ndpr_entry from nd_prefix list */
952 LIST_REMOVE(pr, ndpr_entry);
953
954 /* free list of routers that adversed the prefix */
955 for (pfr = LIST_FIRST(&pr->ndpr_advrtrs); pfr != NULL; pfr = next) {
956 next = LIST_NEXT(pfr, pfr_entry);
957
958 free(pfr, M_IP6NDP);
959 }
960 splx(s);
961
962 free(pr, M_IP6NDP);
963
964 pfxlist_onlink_check();
965 }
966
967 static int
968 prelist_update(struct nd_prefixctl *new,
969 struct nd_defrouter *dr, /* may be NULL */
970 struct mbuf *m,
971 int mcast)
972 {
973 struct in6_ifaddr *ia6 = NULL, *ia6_match = NULL;
974 struct ifaddr *ifa;
975 struct ifnet *ifp = new->ndpr_ifp;
976 struct nd_prefix *pr;
977 int s = splsoftnet();
978 int error = 0;
979 int newprefix = 0;
980 int auth;
981 struct in6_addrlifetime lt6_tmp;
982
983 auth = 0;
984 if (m) {
985 /*
986 * Authenticity for NA consists authentication for
987 * both IP header and IP datagrams, doesn't it ?
988 */
989 #if defined(M_AUTHIPHDR) && defined(M_AUTHIPDGM)
990 auth = (m->m_flags & M_AUTHIPHDR
991 && m->m_flags & M_AUTHIPDGM) ? 1 : 0;
992 #endif
993 }
994
995 if ((pr = nd6_prefix_lookup(new)) != NULL) {
996 /*
997 * nd6_prefix_lookup() ensures that pr and new have the same
998 * prefix on a same interface.
999 */
1000
1001 /*
1002 * Update prefix information. Note that the on-link (L) bit
1003 * and the autonomous (A) bit should NOT be changed from 1
1004 * to 0.
1005 */
1006 if (new->ndpr_raf_onlink == 1)
1007 pr->ndpr_raf_onlink = 1;
1008 if (new->ndpr_raf_auto == 1)
1009 pr->ndpr_raf_auto = 1;
1010 if (new->ndpr_raf_onlink) {
1011 pr->ndpr_vltime = new->ndpr_vltime;
1012 pr->ndpr_pltime = new->ndpr_pltime;
1013 (void)in6_init_prefix_ltimes(pr); /* XXX error case? */
1014 pr->ndpr_lastupdate = time_second;
1015 }
1016
1017 if (new->ndpr_raf_onlink &&
1018 (pr->ndpr_stateflags & NDPRF_ONLINK) == 0) {
1019 int e;
1020
1021 if ((e = nd6_prefix_onlink(pr)) != 0) {
1022 nd6log((LOG_ERR,
1023 "prelist_update: failed to make "
1024 "the prefix %s/%d on-link on %s "
1025 "(errno=%d)\n",
1026 ip6_sprintf(&pr->ndpr_prefix.sin6_addr),
1027 pr->ndpr_plen, if_name(pr->ndpr_ifp), e));
1028 /* proceed anyway. XXX: is it correct? */
1029 }
1030 }
1031
1032 if (dr && pfxrtr_lookup(pr, dr) == NULL)
1033 pfxrtr_add(pr, dr);
1034 } else {
1035 struct nd_prefix *newpr = NULL;
1036
1037 newprefix = 1;
1038
1039 if (new->ndpr_vltime == 0)
1040 goto end;
1041 if (new->ndpr_raf_onlink == 0 && new->ndpr_raf_auto == 0)
1042 goto end;
1043
1044 error = nd6_prelist_add(new, dr, &newpr);
1045 if (error != 0 || newpr == NULL) {
1046 nd6log((LOG_NOTICE, "prelist_update: "
1047 "nd6_prelist_add failed for %s/%d on %s "
1048 "errno=%d, returnpr=%p\n",
1049 ip6_sprintf(&new->ndpr_prefix.sin6_addr),
1050 new->ndpr_plen, if_name(new->ndpr_ifp),
1051 error, newpr));
1052 goto end; /* we should just give up in this case. */
1053 }
1054
1055 /*
1056 * XXX: from the ND point of view, we can ignore a prefix
1057 * with the on-link bit being zero. However, we need a
1058 * prefix structure for references from autoconfigured
1059 * addresses. Thus, we explicitly make sure that the prefix
1060 * itself expires now.
1061 */
1062 if (newpr->ndpr_raf_onlink == 0) {
1063 newpr->ndpr_vltime = 0;
1064 newpr->ndpr_pltime = 0;
1065 in6_init_prefix_ltimes(newpr);
1066 }
1067
1068 pr = newpr;
1069 }
1070
1071 /*
1072 * Address autoconfiguration based on Section 5.5.3 of RFC 2462.
1073 * Note that pr must be non NULL at this point.
1074 */
1075
1076 /* 5.5.3 (a). Ignore the prefix without the A bit set. */
1077 if (!new->ndpr_raf_auto)
1078 goto end;
1079
1080 /*
1081 * 5.5.3 (b). the link-local prefix should have been ignored in
1082 * nd6_ra_input.
1083 */
1084
1085 /* 5.5.3 (c). Consistency check on lifetimes: pltime <= vltime. */
1086 if (new->ndpr_pltime > new->ndpr_vltime) {
1087 error = EINVAL; /* XXX: won't be used */
1088 goto end;
1089 }
1090
1091 /*
1092 * 5.5.3 (d). If the prefix advertised is not equal to the prefix of
1093 * an address configured by stateless autoconfiguration already in the
1094 * list of addresses associated with the interface, and the Valid
1095 * Lifetime is not 0, form an address. We first check if we have
1096 * a matching prefix.
1097 * Note: we apply a clarification in rfc2462bis-02 here. We only
1098 * consider autoconfigured addresses while RFC2462 simply said
1099 * "address".
1100 */
1101 IFADDR_FOREACH(ifa, ifp) {
1102 struct in6_ifaddr *ifa6;
1103 u_int32_t remaininglifetime;
1104
1105 if (ifa->ifa_addr->sa_family != AF_INET6)
1106 continue;
1107
1108 ifa6 = (struct in6_ifaddr *)ifa;
1109
1110 /*
1111 * We only consider autoconfigured addresses as per rfc2462bis.
1112 */
1113 if (!(ifa6->ia6_flags & IN6_IFF_AUTOCONF))
1114 continue;
1115
1116 /*
1117 * Spec is not clear here, but I believe we should concentrate
1118 * on unicast (i.e. not anycast) addresses.
1119 * XXX: other ia6_flags? detached or duplicated?
1120 */
1121 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0)
1122 continue;
1123
1124 /*
1125 * Ignore the address if it is not associated with a prefix
1126 * or is associated with a prefix that is different from this
1127 * one. (pr is never NULL here)
1128 */
1129 if (ifa6->ia6_ndpr != pr)
1130 continue;
1131
1132 if (ia6_match == NULL) /* remember the first one */
1133 ia6_match = ifa6;
1134
1135 /*
1136 * An already autoconfigured address matched. Now that we
1137 * are sure there is at least one matched address, we can
1138 * proceed to 5.5.3. (e): update the lifetimes according to the
1139 * "two hours" rule and the privacy extension.
1140 * We apply some clarifications in rfc2462bis:
1141 * - use remaininglifetime instead of storedlifetime as a
1142 * variable name
1143 * - remove the dead code in the "two-hour" rule
1144 */
1145 #define TWOHOUR (120*60)
1146 lt6_tmp = ifa6->ia6_lifetime;
1147 if (lt6_tmp.ia6t_vltime == ND6_INFINITE_LIFETIME)
1148 remaininglifetime = ND6_INFINITE_LIFETIME;
1149 else if (time_second - ifa6->ia6_updatetime >
1150 lt6_tmp.ia6t_vltime) {
1151 /*
1152 * The case of "invalid" address. We should usually
1153 * not see this case.
1154 */
1155 remaininglifetime = 0;
1156 } else
1157 remaininglifetime = lt6_tmp.ia6t_vltime -
1158 (time_second - ifa6->ia6_updatetime);
1159
1160 /* when not updating, keep the current stored lifetime. */
1161 lt6_tmp.ia6t_vltime = remaininglifetime;
1162
1163 if (TWOHOUR < new->ndpr_vltime ||
1164 remaininglifetime < new->ndpr_vltime) {
1165 lt6_tmp.ia6t_vltime = new->ndpr_vltime;
1166 } else if (remaininglifetime <= TWOHOUR) {
1167 if (auth)
1168 lt6_tmp.ia6t_vltime = new->ndpr_vltime;
1169 } else {
1170 /*
1171 * new->ndpr_vltime <= TWOHOUR &&
1172 * TWOHOUR < remaininglifetime
1173 */
1174 lt6_tmp.ia6t_vltime = TWOHOUR;
1175 }
1176
1177 /* The 2 hour rule is not imposed for preferred lifetime. */
1178 lt6_tmp.ia6t_pltime = new->ndpr_pltime;
1179
1180 in6_init_address_ltimes(pr, <6_tmp);
1181
1182 /*
1183 * We need to treat lifetimes for temporary addresses
1184 * differently, according to
1185 * draft-ietf-ipv6-privacy-addrs-v2-01.txt 3.3 (1);
1186 * we only update the lifetimes when they are in the maximum
1187 * intervals.
1188 */
1189 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0) {
1190 u_int32_t maxvltime, maxpltime;
1191
1192 if (ip6_temp_valid_lifetime >
1193 (u_int32_t)((time_second - ifa6->ia6_createtime) +
1194 ip6_desync_factor)) {
1195 maxvltime = ip6_temp_valid_lifetime -
1196 (time_second - ifa6->ia6_createtime) -
1197 ip6_desync_factor;
1198 } else
1199 maxvltime = 0;
1200 if (ip6_temp_preferred_lifetime >
1201 (u_int32_t)((time_second - ifa6->ia6_createtime) +
1202 ip6_desync_factor)) {
1203 maxpltime = ip6_temp_preferred_lifetime -
1204 (time_second - ifa6->ia6_createtime) -
1205 ip6_desync_factor;
1206 } else
1207 maxpltime = 0;
1208
1209 if (lt6_tmp.ia6t_vltime == ND6_INFINITE_LIFETIME ||
1210 lt6_tmp.ia6t_vltime > maxvltime) {
1211 lt6_tmp.ia6t_vltime = maxvltime;
1212 }
1213 if (lt6_tmp.ia6t_pltime == ND6_INFINITE_LIFETIME ||
1214 lt6_tmp.ia6t_pltime > maxpltime) {
1215 lt6_tmp.ia6t_pltime = maxpltime;
1216 }
1217 }
1218
1219 ifa6->ia6_lifetime = lt6_tmp;
1220 ifa6->ia6_updatetime = time_second;
1221 }
1222 if (ia6_match == NULL && new->ndpr_vltime) {
1223 int ifidlen;
1224
1225 /*
1226 * 5.5.3 (d) (continued)
1227 * No address matched and the valid lifetime is non-zero.
1228 * Create a new address.
1229 */
1230
1231 /*
1232 * Prefix Length check:
1233 * If the sum of the prefix length and interface identifier
1234 * length does not equal 128 bits, the Prefix Information
1235 * option MUST be ignored. The length of the interface
1236 * identifier is defined in a separate link-type specific
1237 * document.
1238 */
1239 ifidlen = in6_if2idlen(ifp);
1240 if (ifidlen < 0) {
1241 /* this should not happen, so we always log it. */
1242 log(LOG_ERR, "prelist_update: IFID undefined (%s)\n",
1243 if_name(ifp));
1244 goto end;
1245 }
1246 if (ifidlen + pr->ndpr_plen != 128) {
1247 nd6log((LOG_INFO,
1248 "prelist_update: invalid prefixlen "
1249 "%d for %s, ignored\n",
1250 pr->ndpr_plen, if_name(ifp)));
1251 goto end;
1252 }
1253
1254 if ((ia6 = in6_ifadd(new, mcast)) != NULL) {
1255 /*
1256 * note that we should use pr (not new) for reference.
1257 */
1258 pr->ndpr_refcnt++;
1259 ia6->ia6_ndpr = pr;
1260
1261 /*
1262 * draft-ietf-ipngwg-temp-addresses-v2-00 3.3 (2).
1263 * When a new public address is created as described
1264 * in RFC2462, also create a new temporary address.
1265 *
1266 * draft-ietf-ipngwg-temp-addresses-v2-00 3.5.
1267 * When an interface connects to a new link, a new
1268 * randomized interface identifier should be generated
1269 * immediately together with a new set of temporary
1270 * addresses. Thus, we specifiy 1 as the 2nd arg of
1271 * in6_tmpifadd().
1272 */
1273 if (ip6_use_tempaddr) {
1274 int e;
1275 if ((e = in6_tmpifadd(ia6, 1, 1)) != 0) {
1276 nd6log((LOG_NOTICE, "prelist_update: "
1277 "failed to create a temporary "
1278 "address, errno=%d\n",
1279 e));
1280 }
1281 }
1282
1283 /*
1284 * A newly added address might affect the status
1285 * of other addresses, so we check and update it.
1286 * XXX: what if address duplication happens?
1287 */
1288 pfxlist_onlink_check();
1289 } else {
1290 /* just set an error. do not bark here. */
1291 error = EADDRNOTAVAIL; /* XXX: might be unused. */
1292 }
1293 }
1294
1295 end:
1296 splx(s);
1297 return error;
1298 }
1299
1300 /*
1301 * A supplement function used in the on-link detection below;
1302 * detect if a given prefix has a (probably) reachable advertising router.
1303 * XXX: lengthy function name...
1304 */
1305 static struct nd_pfxrouter *
1306 find_pfxlist_reachable_router(struct nd_prefix *pr)
1307 {
1308 struct nd_pfxrouter *pfxrtr;
1309 struct rtentry *rt;
1310 struct llinfo_nd6 *ln;
1311
1312 for (pfxrtr = LIST_FIRST(&pr->ndpr_advrtrs); pfxrtr;
1313 pfxrtr = LIST_NEXT(pfxrtr, pfr_entry)) {
1314 if ((rt = nd6_lookup(&pfxrtr->router->rtaddr, 0,
1315 pfxrtr->router->ifp)) &&
1316 (ln = (struct llinfo_nd6 *)rt->rt_llinfo) &&
1317 ND6_IS_LLINFO_PROBREACH(ln))
1318 break; /* found */
1319 }
1320
1321 return (pfxrtr);
1322 }
1323
1324 /*
1325 * Check if each prefix in the prefix list has at least one available router
1326 * that advertised the prefix (a router is "available" if its neighbor cache
1327 * entry is reachable or probably reachable).
1328 * If the check fails, the prefix may be off-link, because, for example,
1329 * we have moved from the network but the lifetime of the prefix has not
1330 * expired yet. So we should not use the prefix if there is another prefix
1331 * that has an available router.
1332 * But, if there is no prefix that has an available router, we still regards
1333 * all the prefixes as on-link. This is because we can't tell if all the
1334 * routers are simply dead or if we really moved from the network and there
1335 * is no router around us.
1336 */
1337 void
1338 pfxlist_onlink_check(void)
1339 {
1340 struct nd_prefix *pr;
1341 struct in6_ifaddr *ifa;
1342 struct nd_defrouter *dr;
1343 struct nd_pfxrouter *pfxrtr = NULL;
1344
1345 /*
1346 * Check if there is a prefix that has a reachable advertising
1347 * router.
1348 */
1349 LIST_FOREACH(pr, &nd_prefix, ndpr_entry) {
1350 if (pr->ndpr_raf_onlink && find_pfxlist_reachable_router(pr))
1351 break;
1352 }
1353 /*
1354 * If we have no such prefix, check whether we still have a router
1355 * that does not advertise any prefixes.
1356 */
1357 if (pr == NULL) {
1358 TAILQ_FOREACH(dr, &nd_defrouter, dr_entry) {
1359 struct nd_prefix *pr0;
1360
1361 LIST_FOREACH(pr0, &nd_prefix, ndpr_entry) {
1362 if ((pfxrtr = pfxrtr_lookup(pr0, dr)) != NULL)
1363 break;
1364 }
1365 if (pfxrtr)
1366 break;
1367 }
1368 }
1369 if (pr != NULL || (TAILQ_FIRST(&nd_defrouter) && !pfxrtr)) {
1370 /*
1371 * There is at least one prefix that has a reachable router,
1372 * or at least a router which probably does not advertise
1373 * any prefixes. The latter would be the case when we move
1374 * to a new link where we have a router that does not provide
1375 * prefixes and we configure an address by hand.
1376 * Detach prefixes which have no reachable advertising
1377 * router, and attach other prefixes.
1378 */
1379 LIST_FOREACH(pr, &nd_prefix, ndpr_entry) {
1380 /* XXX: a link-local prefix should never be detached */
1381 if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr))
1382 continue;
1383
1384 /*
1385 * we aren't interested in prefixes without the L bit
1386 * set.
1387 */
1388 if (pr->ndpr_raf_onlink == 0)
1389 continue;
1390
1391 if ((pr->ndpr_stateflags & NDPRF_DETACHED) == 0 &&
1392 find_pfxlist_reachable_router(pr) == NULL)
1393 pr->ndpr_stateflags |= NDPRF_DETACHED;
1394 if ((pr->ndpr_stateflags & NDPRF_DETACHED) != 0 &&
1395 find_pfxlist_reachable_router(pr) != 0)
1396 pr->ndpr_stateflags &= ~NDPRF_DETACHED;
1397 }
1398 } else {
1399 /* there is no prefix that has a reachable router */
1400 LIST_FOREACH(pr, &nd_prefix, ndpr_entry) {
1401 if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr))
1402 continue;
1403
1404 if (pr->ndpr_raf_onlink == 0)
1405 continue;
1406
1407 if ((pr->ndpr_stateflags & NDPRF_DETACHED) != 0)
1408 pr->ndpr_stateflags &= ~NDPRF_DETACHED;
1409 }
1410 }
1411
1412 /*
1413 * Remove each interface route associated with a (just) detached
1414 * prefix, and reinstall the interface route for a (just) attached
1415 * prefix. Note that all attempt of reinstallation does not
1416 * necessarily success, when a same prefix is shared among multiple
1417 * interfaces. Such cases will be handled in nd6_prefix_onlink,
1418 * so we don't have to care about them.
1419 */
1420 LIST_FOREACH(pr, &nd_prefix, ndpr_entry) {
1421 int e;
1422
1423 if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr))
1424 continue;
1425
1426 if (pr->ndpr_raf_onlink == 0)
1427 continue;
1428
1429 if ((pr->ndpr_stateflags & NDPRF_DETACHED) != 0 &&
1430 (pr->ndpr_stateflags & NDPRF_ONLINK) != 0) {
1431 if ((e = nd6_prefix_offlink(pr)) != 0) {
1432 nd6log((LOG_ERR,
1433 "pfxlist_onlink_check: failed to "
1434 "make %s/%d offlink, errno=%d\n",
1435 ip6_sprintf(&pr->ndpr_prefix.sin6_addr),
1436 pr->ndpr_plen, e));
1437 }
1438 }
1439 if ((pr->ndpr_stateflags & NDPRF_DETACHED) == 0 &&
1440 (pr->ndpr_stateflags & NDPRF_ONLINK) == 0 &&
1441 pr->ndpr_raf_onlink) {
1442 if ((e = nd6_prefix_onlink(pr)) != 0) {
1443 nd6log((LOG_ERR,
1444 "pfxlist_onlink_check: failed to "
1445 "make %s/%d onlink, errno=%d\n",
1446 ip6_sprintf(&pr->ndpr_prefix.sin6_addr),
1447 pr->ndpr_plen, e));
1448 }
1449 }
1450 }
1451
1452 /*
1453 * Changes on the prefix status might affect address status as well.
1454 * Make sure that all addresses derived from an attached prefix are
1455 * attached, and that all addresses derived from a detached prefix are
1456 * detached. Note, however, that a manually configured address should
1457 * always be attached.
1458 * The precise detection logic is same as the one for prefixes.
1459 */
1460 for (ifa = in6_ifaddr; ifa; ifa = ifa->ia_next) {
1461 if (!(ifa->ia6_flags & IN6_IFF_AUTOCONF))
1462 continue;
1463
1464 if (ifa->ia6_ndpr == NULL) {
1465 /*
1466 * This can happen when we first configure the address
1467 * (i.e. the address exists, but the prefix does not).
1468 * XXX: complicated relationships...
1469 */
1470 continue;
1471 }
1472
1473 if (find_pfxlist_reachable_router(ifa->ia6_ndpr))
1474 break;
1475 }
1476 if (ifa) {
1477 for (ifa = in6_ifaddr; ifa; ifa = ifa->ia_next) {
1478 if ((ifa->ia6_flags & IN6_IFF_AUTOCONF) == 0)
1479 continue;
1480
1481 if (ifa->ia6_ndpr == NULL) /* XXX: see above. */
1482 continue;
1483
1484 if (find_pfxlist_reachable_router(ifa->ia6_ndpr)) {
1485 if (ifa->ia6_flags & IN6_IFF_DETACHED) {
1486 ifa->ia6_flags &= ~IN6_IFF_DETACHED;
1487 ifa->ia6_flags |= IN6_IFF_TENTATIVE;
1488 nd6_dad_start((struct ifaddr *)ifa,
1489 0);
1490 }
1491 } else {
1492 if ((ifa->ia6_flags & IN6_IFF_DETACHED) == 0) {
1493 ifa->ia6_flags |= IN6_IFF_DETACHED;
1494 }
1495 }
1496 }
1497 }
1498 else {
1499 for (ifa = in6_ifaddr; ifa; ifa = ifa->ia_next) {
1500 if ((ifa->ia6_flags & IN6_IFF_AUTOCONF) == 0)
1501 continue;
1502
1503 if (ifa->ia6_flags & IN6_IFF_DETACHED) {
1504 ifa->ia6_flags &= ~IN6_IFF_DETACHED;
1505 ifa->ia6_flags |= IN6_IFF_TENTATIVE;
1506 /* Do we need a delay in this case? */
1507 nd6_dad_start((struct ifaddr *)ifa, 0);
1508 }
1509 }
1510 }
1511 }
1512
1513 int
1514 nd6_prefix_onlink(struct nd_prefix *pr)
1515 {
1516 struct ifaddr *ifa;
1517 struct ifnet *ifp = pr->ndpr_ifp;
1518 struct sockaddr_in6 mask6;
1519 struct nd_prefix *opr;
1520 u_long rtflags;
1521 int error = 0;
1522 struct rtentry *rt = NULL;
1523
1524 /* sanity check */
1525 if ((pr->ndpr_stateflags & NDPRF_ONLINK) != 0) {
1526 nd6log((LOG_ERR,
1527 "nd6_prefix_onlink: %s/%d is already on-link\n",
1528 ip6_sprintf(&pr->ndpr_prefix.sin6_addr), pr->ndpr_plen));
1529 return (EEXIST);
1530 }
1531
1532 /*
1533 * Add the interface route associated with the prefix. Before
1534 * installing the route, check if there's the same prefix on another
1535 * interface, and the prefix has already installed the interface route.
1536 * Although such a configuration is expected to be rare, we explicitly
1537 * allow it.
1538 */
1539 LIST_FOREACH(opr, &nd_prefix, ndpr_entry) {
1540 if (opr == pr)
1541 continue;
1542
1543 if ((opr->ndpr_stateflags & NDPRF_ONLINK) == 0)
1544 continue;
1545
1546 if (opr->ndpr_plen == pr->ndpr_plen &&
1547 in6_are_prefix_equal(&pr->ndpr_prefix.sin6_addr,
1548 &opr->ndpr_prefix.sin6_addr, pr->ndpr_plen))
1549 return (0);
1550 }
1551
1552 /*
1553 * We prefer link-local addresses as the associated interface address.
1554 */
1555 /* search for a link-local addr */
1556 ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp,
1557 IN6_IFF_NOTREADY | IN6_IFF_ANYCAST);
1558 if (ifa == NULL) {
1559 /* XXX: freebsd does not have ifa_ifwithaf */
1560 IFADDR_FOREACH(ifa, ifp) {
1561 if (ifa->ifa_addr->sa_family == AF_INET6)
1562 break;
1563 }
1564 /* should we care about ia6_flags? */
1565 }
1566 if (ifa == NULL) {
1567 /*
1568 * This can still happen, when, for example, we receive an RA
1569 * containing a prefix with the L bit set and the A bit clear,
1570 * after removing all IPv6 addresses on the receiving
1571 * interface. This should, of course, be rare though.
1572 */
1573 nd6log((LOG_NOTICE,
1574 "nd6_prefix_onlink: failed to find any ifaddr"
1575 " to add route for a prefix(%s/%d) on %s\n",
1576 ip6_sprintf(&pr->ndpr_prefix.sin6_addr),
1577 pr->ndpr_plen, if_name(ifp)));
1578 return (0);
1579 }
1580
1581 /*
1582 * in6_ifinit() sets nd6_rtrequest to ifa_rtrequest for all ifaddrs.
1583 * ifa->ifa_rtrequest = nd6_rtrequest;
1584 */
1585 bzero(&mask6, sizeof(mask6));
1586 mask6.sin6_len = sizeof(mask6);
1587 mask6.sin6_addr = pr->ndpr_mask;
1588 /* rtrequest() will probably set RTF_UP, but we're not sure. */
1589 rtflags = ifa->ifa_flags | RTF_UP;
1590 if (nd6_need_cache(ifp)) {
1591 /* explicitly set in case ifa_flags does not set the flag. */
1592 rtflags |= RTF_CLONING;
1593 } else {
1594 /*
1595 * explicitly clear the cloning bit in case ifa_flags sets it.
1596 */
1597 rtflags &= ~RTF_CLONING;
1598 }
1599 error = rtrequest(RTM_ADD, (struct sockaddr *)&pr->ndpr_prefix,
1600 ifa->ifa_addr, (struct sockaddr *)&mask6, rtflags, &rt);
1601 if (error == 0) {
1602 if (rt != NULL) /* this should be non NULL, though */
1603 nd6_rtmsg(RTM_ADD, rt);
1604 pr->ndpr_stateflags |= NDPRF_ONLINK;
1605 } else {
1606 nd6log((LOG_ERR, "nd6_prefix_onlink: failed to add route for a"
1607 " prefix (%s/%d) on %s, gw=%s, mask=%s, flags=%lx "
1608 "errno = %d\n",
1609 ip6_sprintf(&pr->ndpr_prefix.sin6_addr),
1610 pr->ndpr_plen, if_name(ifp),
1611 ip6_sprintf(&((struct sockaddr_in6 *)ifa->ifa_addr)->sin6_addr),
1612 ip6_sprintf(&mask6.sin6_addr), rtflags, error));
1613 }
1614
1615 if (rt != NULL)
1616 rt->rt_refcnt--;
1617
1618 return (error);
1619 }
1620
1621 int
1622 nd6_prefix_offlink(struct nd_prefix *pr)
1623 {
1624 int error = 0;
1625 struct ifnet *ifp = pr->ndpr_ifp;
1626 struct nd_prefix *opr;
1627 struct sockaddr_in6 sa6, mask6;
1628 struct rtentry *rt = NULL;
1629
1630 /* sanity check */
1631 if ((pr->ndpr_stateflags & NDPRF_ONLINK) == 0) {
1632 nd6log((LOG_ERR,
1633 "nd6_prefix_offlink: %s/%d is already off-link\n",
1634 ip6_sprintf(&pr->ndpr_prefix.sin6_addr), pr->ndpr_plen));
1635 return (EEXIST);
1636 }
1637
1638 sockaddr_in6_init(&sa6, &pr->ndpr_prefix.sin6_addr, 0, 0, 0);
1639 sockaddr_in6_init(&mask6, &pr->ndpr_mask, 0, 0, 0);
1640 error = rtrequest(RTM_DELETE, (struct sockaddr *)&sa6, NULL,
1641 (struct sockaddr *)&mask6, 0, &rt);
1642 if (error == 0) {
1643 pr->ndpr_stateflags &= ~NDPRF_ONLINK;
1644
1645 /* report the route deletion to the routing socket. */
1646 if (rt != NULL)
1647 nd6_rtmsg(RTM_DELETE, rt);
1648
1649 /*
1650 * There might be the same prefix on another interface,
1651 * the prefix which could not be on-link just because we have
1652 * the interface route (see comments in nd6_prefix_onlink).
1653 * If there's one, try to make the prefix on-link on the
1654 * interface.
1655 */
1656 LIST_FOREACH(opr, &nd_prefix, ndpr_entry) {
1657 if (opr == pr)
1658 continue;
1659
1660 if ((opr->ndpr_stateflags & NDPRF_ONLINK) != 0)
1661 continue;
1662
1663 /*
1664 * KAME specific: detached prefixes should not be
1665 * on-link.
1666 */
1667 if ((opr->ndpr_stateflags & NDPRF_DETACHED) != 0)
1668 continue;
1669
1670 if (opr->ndpr_plen == pr->ndpr_plen &&
1671 in6_are_prefix_equal(&pr->ndpr_prefix.sin6_addr,
1672 &opr->ndpr_prefix.sin6_addr, pr->ndpr_plen)) {
1673 int e;
1674
1675 if ((e = nd6_prefix_onlink(opr)) != 0) {
1676 nd6log((LOG_ERR,
1677 "nd6_prefix_offlink: failed to "
1678 "recover a prefix %s/%d from %s "
1679 "to %s (errno = %d)\n",
1680 ip6_sprintf(&opr->ndpr_prefix.sin6_addr),
1681 opr->ndpr_plen, if_name(ifp),
1682 if_name(opr->ndpr_ifp), e));
1683 }
1684 }
1685 }
1686 } else {
1687 /* XXX: can we still set the NDPRF_ONLINK flag? */
1688 nd6log((LOG_ERR,
1689 "nd6_prefix_offlink: failed to delete route: "
1690 "%s/%d on %s (errno = %d)\n",
1691 ip6_sprintf(&sa6.sin6_addr), pr->ndpr_plen, if_name(ifp),
1692 error));
1693 }
1694
1695 if (rt != NULL) {
1696 if (rt->rt_refcnt <= 0) {
1697 /* XXX: we should free the entry ourselves. */
1698 rt->rt_refcnt++;
1699 rtfree(rt);
1700 }
1701 }
1702
1703 return (error);
1704 }
1705
1706 static struct in6_ifaddr *
1707 in6_ifadd(struct nd_prefixctl *pr, int mcast)
1708 {
1709 struct ifnet *ifp = pr->ndpr_ifp;
1710 struct ifaddr *ifa;
1711 struct in6_aliasreq ifra;
1712 struct in6_ifaddr *ia, *ib;
1713 int error, plen0;
1714 struct in6_addr mask;
1715 int prefixlen = pr->ndpr_plen;
1716 int updateflags;
1717
1718 in6_prefixlen2mask(&mask, prefixlen);
1719
1720 /*
1721 * find a link-local address (will be interface ID).
1722 * Is it really mandatory? Theoretically, a global or a site-local
1723 * address can be configured without a link-local address, if we
1724 * have a unique interface identifier...
1725 *
1726 * it is not mandatory to have a link-local address, we can generate
1727 * interface identifier on the fly. we do this because:
1728 * (1) it should be the easiest way to find interface identifier.
1729 * (2) RFC2462 5.4 suggesting the use of the same interface identifier
1730 * for multiple addresses on a single interface, and possible shortcut
1731 * of DAD. we omitted DAD for this reason in the past.
1732 * (3) a user can prevent autoconfiguration of global address
1733 * by removing link-local address by hand (this is partly because we
1734 * don't have other way to control the use of IPv6 on an interface.
1735 * this has been our design choice - cf. NRL's "ifconfig auto").
1736 * (4) it is easier to manage when an interface has addresses
1737 * with the same interface identifier, than to have multiple addresses
1738 * with different interface identifiers.
1739 */
1740 ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp, 0); /* 0 is OK? */
1741 if (ifa)
1742 ib = (struct in6_ifaddr *)ifa;
1743 else
1744 return NULL;
1745
1746 #if 0 /* don't care link local addr state, and always do DAD */
1747 /* if link-local address is not eligible, do not autoconfigure. */
1748 if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_NOTREADY) {
1749 printf("in6_ifadd: link-local address not ready\n");
1750 return NULL;
1751 }
1752 #endif
1753
1754 /* prefixlen + ifidlen must be equal to 128 */
1755 plen0 = in6_mask2len(&ib->ia_prefixmask.sin6_addr, NULL);
1756 if (prefixlen != plen0) {
1757 nd6log((LOG_INFO, "in6_ifadd: wrong prefixlen for %s "
1758 "(prefix=%d ifid=%d)\n",
1759 if_name(ifp), prefixlen, 128 - plen0));
1760 return NULL;
1761 }
1762
1763 /* make ifaddr */
1764
1765 memset(&ifra, 0, sizeof(ifra));
1766 /*
1767 * in6_update_ifa() does not use ifra_name, but we accurately set it
1768 * for safety.
1769 */
1770 strncpy(ifra.ifra_name, if_name(ifp), sizeof(ifra.ifra_name));
1771 sockaddr_in6_init(&ifra.ifra_addr, &pr->ndpr_prefix.sin6_addr, 0, 0, 0);
1772 /* prefix */
1773 ifra.ifra_addr.sin6_addr.s6_addr32[0] &= mask.s6_addr32[0];
1774 ifra.ifra_addr.sin6_addr.s6_addr32[1] &= mask.s6_addr32[1];
1775 ifra.ifra_addr.sin6_addr.s6_addr32[2] &= mask.s6_addr32[2];
1776 ifra.ifra_addr.sin6_addr.s6_addr32[3] &= mask.s6_addr32[3];
1777
1778 /* interface ID */
1779 ifra.ifra_addr.sin6_addr.s6_addr32[0] |=
1780 (ib->ia_addr.sin6_addr.s6_addr32[0] & ~mask.s6_addr32[0]);
1781 ifra.ifra_addr.sin6_addr.s6_addr32[1] |=
1782 (ib->ia_addr.sin6_addr.s6_addr32[1] & ~mask.s6_addr32[1]);
1783 ifra.ifra_addr.sin6_addr.s6_addr32[2] |=
1784 (ib->ia_addr.sin6_addr.s6_addr32[2] & ~mask.s6_addr32[2]);
1785 ifra.ifra_addr.sin6_addr.s6_addr32[3] |=
1786 (ib->ia_addr.sin6_addr.s6_addr32[3] & ~mask.s6_addr32[3]);
1787
1788 /* new prefix mask. */
1789 sockaddr_in6_init(&ifra.ifra_prefixmask, &mask, 0, 0, 0);
1790
1791 /* lifetimes */
1792 ifra.ifra_lifetime.ia6t_vltime = pr->ndpr_vltime;
1793 ifra.ifra_lifetime.ia6t_pltime = pr->ndpr_pltime;
1794
1795 /* XXX: scope zone ID? */
1796
1797 ifra.ifra_flags |= IN6_IFF_AUTOCONF; /* obey autoconf */
1798
1799 /*
1800 * Make sure that we do not have this address already. This should
1801 * usually not happen, but we can still see this case, e.g., if we
1802 * have manually configured the exact address to be configured.
1803 */
1804 if (in6ifa_ifpwithaddr(ifp, &ifra.ifra_addr.sin6_addr) != NULL) {
1805 /* this should be rare enough to make an explicit log */
1806 log(LOG_INFO, "in6_ifadd: %s is already configured\n",
1807 ip6_sprintf(&ifra.ifra_addr.sin6_addr));
1808 return (NULL);
1809 }
1810
1811 /*
1812 * Allocate ifaddr structure, link into chain, etc.
1813 * If we are going to create a new address upon receiving a multicasted
1814 * RA, we need to impose a random delay before starting DAD.
1815 * [draft-ietf-ipv6-rfc2462bis-02.txt, Section 5.4.2]
1816 */
1817 updateflags = 0;
1818 if (mcast)
1819 updateflags |= IN6_IFAUPDATE_DADDELAY;
1820 if ((error = in6_update_ifa(ifp, &ifra, NULL, updateflags)) != 0) {
1821 nd6log((LOG_ERR,
1822 "in6_ifadd: failed to make ifaddr %s on %s (errno=%d)\n",
1823 ip6_sprintf(&ifra.ifra_addr.sin6_addr), if_name(ifp),
1824 error));
1825 return (NULL); /* ifaddr must not have been allocated. */
1826 }
1827
1828 ia = in6ifa_ifpwithaddr(ifp, &ifra.ifra_addr.sin6_addr);
1829
1830 return (ia); /* this is always non-NULL */
1831 }
1832
1833 int
1834 in6_tmpifadd(
1835 const struct in6_ifaddr *ia0, /* corresponding public address */
1836 int forcegen,
1837 int dad_delay)
1838 {
1839 struct ifnet *ifp = ia0->ia_ifa.ifa_ifp;
1840 struct in6_ifaddr *newia, *ia;
1841 struct in6_aliasreq ifra;
1842 int i, error;
1843 int trylimit = 3; /* XXX: adhoc value */
1844 int updateflags;
1845 u_int32_t randid[2];
1846 u_int32_t vltime0, pltime0;
1847
1848 memset(&ifra, 0, sizeof(ifra));
1849 strncpy(ifra.ifra_name, if_name(ifp), sizeof(ifra.ifra_name));
1850 ifra.ifra_addr = ia0->ia_addr;
1851 /* copy prefix mask */
1852 ifra.ifra_prefixmask = ia0->ia_prefixmask;
1853 /* clear the old IFID */
1854 for (i = 0; i < 4; i++) {
1855 ifra.ifra_addr.sin6_addr.s6_addr32[i] &=
1856 ifra.ifra_prefixmask.sin6_addr.s6_addr32[i];
1857 }
1858
1859 again:
1860 if (in6_get_tmpifid(ifp, (u_int8_t *)randid,
1861 (const u_int8_t *)&ia0->ia_addr.sin6_addr.s6_addr[8], forcegen)) {
1862 nd6log((LOG_NOTICE, "in6_tmpifadd: failed to find a good "
1863 "random IFID\n"));
1864 return (EINVAL);
1865 }
1866 ifra.ifra_addr.sin6_addr.s6_addr32[2] |=
1867 (randid[0] & ~(ifra.ifra_prefixmask.sin6_addr.s6_addr32[2]));
1868 ifra.ifra_addr.sin6_addr.s6_addr32[3] |=
1869 (randid[1] & ~(ifra.ifra_prefixmask.sin6_addr.s6_addr32[3]));
1870
1871 /*
1872 * in6_get_tmpifid() quite likely provided a unique interface ID.
1873 * However, we may still have a chance to see collision, because
1874 * there may be a time lag between generation of the ID and generation
1875 * of the address. So, we'll do one more sanity check.
1876 */
1877 for (ia = in6_ifaddr; ia; ia = ia->ia_next) {
1878 if (IN6_ARE_ADDR_EQUAL(&ia->ia_addr.sin6_addr,
1879 &ifra.ifra_addr.sin6_addr)) {
1880 if (trylimit-- == 0) {
1881 /*
1882 * Give up. Something strange should have
1883 * happened.
1884 */
1885 nd6log((LOG_NOTICE, "in6_tmpifadd: failed to "
1886 "find a unique random IFID\n"));
1887 return (EEXIST);
1888 }
1889 forcegen = 1;
1890 goto again;
1891 }
1892 }
1893
1894 /*
1895 * The Valid Lifetime is the lower of the Valid Lifetime of the
1896 * public address or TEMP_VALID_LIFETIME.
1897 * The Preferred Lifetime is the lower of the Preferred Lifetime
1898 * of the public address or TEMP_PREFERRED_LIFETIME -
1899 * DESYNC_FACTOR.
1900 */
1901 if (ia0->ia6_lifetime.ia6t_vltime != ND6_INFINITE_LIFETIME) {
1902 vltime0 = IFA6_IS_INVALID(ia0) ? 0 :
1903 (ia0->ia6_lifetime.ia6t_vltime -
1904 (time_second - ia0->ia6_updatetime));
1905 if (vltime0 > ip6_temp_valid_lifetime)
1906 vltime0 = ip6_temp_valid_lifetime;
1907 } else
1908 vltime0 = ip6_temp_valid_lifetime;
1909 if (ia0->ia6_lifetime.ia6t_pltime != ND6_INFINITE_LIFETIME) {
1910 pltime0 = IFA6_IS_DEPRECATED(ia0) ? 0 :
1911 (ia0->ia6_lifetime.ia6t_pltime -
1912 (time_second - ia0->ia6_updatetime));
1913 if (pltime0 > ip6_temp_preferred_lifetime - ip6_desync_factor){
1914 pltime0 = ip6_temp_preferred_lifetime -
1915 ip6_desync_factor;
1916 }
1917 } else
1918 pltime0 = ip6_temp_preferred_lifetime - ip6_desync_factor;
1919 ifra.ifra_lifetime.ia6t_vltime = vltime0;
1920 ifra.ifra_lifetime.ia6t_pltime = pltime0;
1921
1922 /*
1923 * A temporary address is created only if this calculated Preferred
1924 * Lifetime is greater than REGEN_ADVANCE time units.
1925 */
1926 if (ifra.ifra_lifetime.ia6t_pltime <= ip6_temp_regen_advance)
1927 return (0);
1928
1929 /* XXX: scope zone ID? */
1930
1931 ifra.ifra_flags |= (IN6_IFF_AUTOCONF|IN6_IFF_TEMPORARY);
1932
1933 /* allocate ifaddr structure, link into chain, etc. */
1934 updateflags = 0;
1935 if (dad_delay)
1936 updateflags |= IN6_IFAUPDATE_DADDELAY;
1937 if ((error = in6_update_ifa(ifp, &ifra, NULL, updateflags)) != 0)
1938 return (error);
1939
1940 newia = in6ifa_ifpwithaddr(ifp, &ifra.ifra_addr.sin6_addr);
1941 if (newia == NULL) { /* XXX: can it happen? */
1942 nd6log((LOG_ERR,
1943 "in6_tmpifadd: ifa update succeeded, but we got "
1944 "no ifaddr\n"));
1945 return (EINVAL); /* XXX */
1946 }
1947 newia->ia6_ndpr = ia0->ia6_ndpr;
1948 newia->ia6_ndpr->ndpr_refcnt++;
1949
1950 /*
1951 * A newly added address might affect the status of other addresses.
1952 * XXX: when the temporary address is generated with a new public
1953 * address, the onlink check is redundant. However, it would be safe
1954 * to do the check explicitly everywhere a new address is generated,
1955 * and, in fact, we surely need the check when we create a new
1956 * temporary address due to deprecation of an old temporary address.
1957 */
1958 pfxlist_onlink_check();
1959
1960 return (0);
1961 }
1962
1963 static int
1964 in6_init_prefix_ltimes(struct nd_prefix *ndpr)
1965 {
1966
1967 /* check if preferred lifetime > valid lifetime. RFC2462 5.5.3 (c) */
1968 if (ndpr->ndpr_pltime > ndpr->ndpr_vltime) {
1969 nd6log((LOG_INFO, "in6_init_prefix_ltimes: preferred lifetime"
1970 "(%d) is greater than valid lifetime(%d)\n",
1971 (u_int)ndpr->ndpr_pltime, (u_int)ndpr->ndpr_vltime));
1972 return (EINVAL);
1973 }
1974 if (ndpr->ndpr_pltime == ND6_INFINITE_LIFETIME)
1975 ndpr->ndpr_preferred = 0;
1976 else
1977 ndpr->ndpr_preferred = time_second + ndpr->ndpr_pltime;
1978 if (ndpr->ndpr_vltime == ND6_INFINITE_LIFETIME)
1979 ndpr->ndpr_expire = 0;
1980 else
1981 ndpr->ndpr_expire = time_second + ndpr->ndpr_vltime;
1982
1983 return 0;
1984 }
1985
1986 static void
1987 in6_init_address_ltimes(struct nd_prefix *new,
1988 struct in6_addrlifetime *lt6)
1989 {
1990
1991 /* Valid lifetime must not be updated unless explicitly specified. */
1992 /* init ia6t_expire */
1993 if (lt6->ia6t_vltime == ND6_INFINITE_LIFETIME)
1994 lt6->ia6t_expire = 0;
1995 else {
1996 lt6->ia6t_expire = time_second;
1997 lt6->ia6t_expire += lt6->ia6t_vltime;
1998 }
1999
2000 /* init ia6t_preferred */
2001 if (lt6->ia6t_pltime == ND6_INFINITE_LIFETIME)
2002 lt6->ia6t_preferred = 0;
2003 else {
2004 lt6->ia6t_preferred = time_second;
2005 lt6->ia6t_preferred += lt6->ia6t_pltime;
2006 }
2007 }
2008
2009 /*
2010 * Delete all the routing table entries that use the specified gateway.
2011 * XXX: this function causes search through all entries of routing table, so
2012 * it shouldn't be called when acting as a router.
2013 */
2014 void
2015 rt6_flush(struct in6_addr *gateway, struct ifnet *ifp)
2016 {
2017 int s = splsoftnet();
2018
2019 /* We'll care only link-local addresses */
2020 if (!IN6_IS_ADDR_LINKLOCAL(gateway)) {
2021 splx(s);
2022 return;
2023 }
2024
2025 rt_walktree(AF_INET6, rt6_deleteroute, (void *)gateway);
2026 splx(s);
2027 }
2028
2029 static int
2030 rt6_deleteroute(struct rtentry *rt, void *arg)
2031 {
2032 #define SIN6(s) ((struct sockaddr_in6 *)s)
2033 struct in6_addr *gate = (struct in6_addr *)arg;
2034
2035 if (rt->rt_gateway == NULL || rt->rt_gateway->sa_family != AF_INET6)
2036 return (0);
2037
2038 if (!IN6_ARE_ADDR_EQUAL(gate, &SIN6(rt->rt_gateway)->sin6_addr))
2039 return (0);
2040
2041 /*
2042 * Do not delete a static route.
2043 * XXX: this seems to be a bit ad-hoc. Should we consider the
2044 * 'cloned' bit instead?
2045 */
2046 if ((rt->rt_flags & RTF_STATIC) != 0)
2047 return (0);
2048
2049 /*
2050 * We delete only host route. This means, in particular, we don't
2051 * delete default route.
2052 */
2053 if ((rt->rt_flags & RTF_HOST) == 0)
2054 return (0);
2055
2056 return (rtrequest(RTM_DELETE, rt_getkey(rt), rt->rt_gateway,
2057 rt_mask(rt), rt->rt_flags, 0));
2058 #undef SIN6
2059 }
2060
2061 int
2062 nd6_setdefaultiface(int ifindex)
2063 {
2064 int error = 0;
2065
2066 if (ifindex < 0 || if_indexlim <= ifindex)
2067 return (EINVAL);
2068 if (ifindex != 0 && !ifindex2ifnet[ifindex])
2069 return (EINVAL);
2070
2071 if (nd6_defifindex != ifindex) {
2072 nd6_defifindex = ifindex;
2073 if (nd6_defifindex > 0) {
2074 nd6_defifp = ifindex2ifnet[nd6_defifindex];
2075 } else
2076 nd6_defifp = NULL;
2077
2078 /*
2079 * Our current implementation assumes one-to-one maping between
2080 * interfaces and links, so it would be natural to use the
2081 * default interface as the default link.
2082 */
2083 scope6_setdefault(nd6_defifp);
2084 }
2085
2086 return (error);
2087 }
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