1 /*-
2 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of the project nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 * $KAME: nd6_rtr.c,v 1.111 2001/04/27 01:37:15 jinmei Exp $
30 */
31
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD: releng/7.4/sys/netinet6/nd6_rtr.c 182632 2008-09-01 19:23:04Z obrien $");
34
35 #include "opt_inet.h"
36 #include "opt_inet6.h"
37
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/malloc.h>
41 #include <sys/mbuf.h>
42 #include <sys/socket.h>
43 #include <sys/sockio.h>
44 #include <sys/time.h>
45 #include <sys/kernel.h>
46 #include <sys/errno.h>
47 #include <sys/syslog.h>
48 #include <sys/queue.h>
49
50 #include <net/if.h>
51 #include <net/if_types.h>
52 #include <net/if_dl.h>
53 #include <net/route.h>
54 #include <net/radix.h>
55
56 #include <netinet/in.h>
57 #include <netinet6/in6_var.h>
58 #include <netinet6/in6_ifattach.h>
59 #include <netinet/ip6.h>
60 #include <netinet6/ip6_var.h>
61 #include <netinet6/nd6.h>
62 #include <netinet/icmp6.h>
63 #include <netinet6/scope6_var.h>
64
65 #define SDL(s) ((struct sockaddr_dl *)s)
66
67 static int rtpref(struct nd_defrouter *);
68 static struct nd_defrouter *defrtrlist_update(struct nd_defrouter *);
69 static int prelist_update __P((struct nd_prefixctl *, struct nd_defrouter *,
70 struct mbuf *, int));
71 static struct in6_ifaddr *in6_ifadd(struct nd_prefixctl *, int);
72 static struct nd_pfxrouter *pfxrtr_lookup __P((struct nd_prefix *,
73 struct nd_defrouter *));
74 static void pfxrtr_add(struct nd_prefix *, struct nd_defrouter *);
75 static void pfxrtr_del(struct nd_pfxrouter *);
76 static struct nd_pfxrouter *find_pfxlist_reachable_router
77 (struct nd_prefix *);
78 static void defrouter_delreq(struct nd_defrouter *);
79 static void nd6_rtmsg(int, struct rtentry *);
80
81 static int in6_init_prefix_ltimes(struct nd_prefix *);
82 static void in6_init_address_ltimes __P((struct nd_prefix *,
83 struct in6_addrlifetime *));
84
85 static int rt6_deleteroute(struct radix_node *, void *);
86
87 extern int nd6_recalc_reachtm_interval;
88
89 static struct ifnet *nd6_defifp;
90 int nd6_defifindex;
91
92 int ip6_use_tempaddr = 0;
93
94 int ip6_desync_factor;
95 u_int32_t ip6_temp_preferred_lifetime = DEF_TEMP_PREFERRED_LIFETIME;
96 u_int32_t ip6_temp_valid_lifetime = DEF_TEMP_VALID_LIFETIME;
97 /*
98 * shorter lifetimes for debugging purposes.
99 int ip6_temp_preferred_lifetime = 800;
100 static int ip6_temp_valid_lifetime = 1800;
101 */
102 int ip6_temp_regen_advance = TEMPADDR_REGEN_ADVANCE;
103
104 /* RTPREF_MEDIUM has to be 0! */
105 #define RTPREF_HIGH 1
106 #define RTPREF_MEDIUM 0
107 #define RTPREF_LOW (-1)
108 #define RTPREF_RESERVED (-2)
109 #define RTPREF_INVALID (-3) /* internal */
110
111 /*
112 * Receive Router Solicitation Message - just for routers.
113 * Router solicitation/advertisement is mostly managed by userland program
114 * (rtadvd) so here we have no function like nd6_ra_output().
115 *
116 * Based on RFC 2461
117 */
118 void
119 nd6_rs_input(struct mbuf *m, int off, int icmp6len)
120 {
121 struct ifnet *ifp = m->m_pkthdr.rcvif;
122 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
123 struct nd_router_solicit *nd_rs;
124 struct in6_addr saddr6 = ip6->ip6_src;
125 char *lladdr = NULL;
126 int lladdrlen = 0;
127 union nd_opts ndopts;
128 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
129
130 /* If I'm not a router, ignore it. */
131 if (ip6_accept_rtadv != 0 || ip6_forwarding != 1)
132 goto freeit;
133
134 /* Sanity checks */
135 if (ip6->ip6_hlim != 255) {
136 nd6log((LOG_ERR,
137 "nd6_rs_input: invalid hlim (%d) from %s to %s on %s\n",
138 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src),
139 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp)));
140 goto bad;
141 }
142
143 /*
144 * Don't update the neighbor cache, if src = ::.
145 * This indicates that the src has no IP address assigned yet.
146 */
147 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6))
148 goto freeit;
149
150 #ifndef PULLDOWN_TEST
151 IP6_EXTHDR_CHECK(m, off, icmp6len,);
152 nd_rs = (struct nd_router_solicit *)((caddr_t)ip6 + off);
153 #else
154 IP6_EXTHDR_GET(nd_rs, struct nd_router_solicit *, m, off, icmp6len);
155 if (nd_rs == NULL) {
156 icmp6stat.icp6s_tooshort++;
157 return;
158 }
159 #endif
160
161 icmp6len -= sizeof(*nd_rs);
162 nd6_option_init(nd_rs + 1, icmp6len, &ndopts);
163 if (nd6_options(&ndopts) < 0) {
164 nd6log((LOG_INFO,
165 "nd6_rs_input: invalid ND option, ignored\n"));
166 /* nd6_options have incremented stats */
167 goto freeit;
168 }
169
170 if (ndopts.nd_opts_src_lladdr) {
171 lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1);
172 lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3;
173 }
174
175 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
176 nd6log((LOG_INFO,
177 "nd6_rs_input: lladdrlen mismatch for %s "
178 "(if %d, RS packet %d)\n",
179 ip6_sprintf(ip6bufs, &saddr6),
180 ifp->if_addrlen, lladdrlen - 2));
181 goto bad;
182 }
183
184 nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, ND_ROUTER_SOLICIT, 0);
185
186 freeit:
187 m_freem(m);
188 return;
189
190 bad:
191 icmp6stat.icp6s_badrs++;
192 m_freem(m);
193 }
194
195 /*
196 * Receive Router Advertisement Message.
197 *
198 * Based on RFC 2461
199 * TODO: on-link bit on prefix information
200 * TODO: ND_RA_FLAG_{OTHER,MANAGED} processing
201 */
202 void
203 nd6_ra_input(struct mbuf *m, int off, int icmp6len)
204 {
205 struct ifnet *ifp = m->m_pkthdr.rcvif;
206 struct nd_ifinfo *ndi = ND_IFINFO(ifp);
207 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
208 struct nd_router_advert *nd_ra;
209 struct in6_addr saddr6 = ip6->ip6_src;
210 int mcast = 0;
211 union nd_opts ndopts;
212 struct nd_defrouter *dr;
213 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
214
215 /*
216 * We only accept RAs only when
217 * the system-wide variable allows the acceptance, and
218 * per-interface variable allows RAs on the receiving interface.
219 */
220 if (ip6_accept_rtadv == 0)
221 goto freeit;
222 if (!(ndi->flags & ND6_IFF_ACCEPT_RTADV))
223 goto freeit;
224
225 if (ip6->ip6_hlim != 255) {
226 nd6log((LOG_ERR,
227 "nd6_ra_input: invalid hlim (%d) from %s to %s on %s\n",
228 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src),
229 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp)));
230 goto bad;
231 }
232
233 if (!IN6_IS_ADDR_LINKLOCAL(&saddr6)) {
234 nd6log((LOG_ERR,
235 "nd6_ra_input: src %s is not link-local\n",
236 ip6_sprintf(ip6bufs, &saddr6)));
237 goto bad;
238 }
239
240 #ifndef PULLDOWN_TEST
241 IP6_EXTHDR_CHECK(m, off, icmp6len,);
242 nd_ra = (struct nd_router_advert *)((caddr_t)ip6 + off);
243 #else
244 IP6_EXTHDR_GET(nd_ra, struct nd_router_advert *, m, off, icmp6len);
245 if (nd_ra == NULL) {
246 icmp6stat.icp6s_tooshort++;
247 return;
248 }
249 #endif
250
251 icmp6len -= sizeof(*nd_ra);
252 nd6_option_init(nd_ra + 1, icmp6len, &ndopts);
253 if (nd6_options(&ndopts) < 0) {
254 nd6log((LOG_INFO,
255 "nd6_ra_input: invalid ND option, ignored\n"));
256 /* nd6_options have incremented stats */
257 goto freeit;
258 }
259
260 {
261 struct nd_defrouter dr0;
262 u_int32_t advreachable = nd_ra->nd_ra_reachable;
263
264 /* remember if this is a multicasted advertisement */
265 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst))
266 mcast = 1;
267
268 bzero(&dr0, sizeof(dr0));
269 dr0.rtaddr = saddr6;
270 dr0.flags = nd_ra->nd_ra_flags_reserved;
271 dr0.rtlifetime = ntohs(nd_ra->nd_ra_router_lifetime);
272 dr0.expire = time_second + dr0.rtlifetime;
273 dr0.ifp = ifp;
274 /* unspecified or not? (RFC 2461 6.3.4) */
275 if (advreachable) {
276 advreachable = ntohl(advreachable);
277 if (advreachable <= MAX_REACHABLE_TIME &&
278 ndi->basereachable != advreachable) {
279 ndi->basereachable = advreachable;
280 ndi->reachable = ND_COMPUTE_RTIME(ndi->basereachable);
281 ndi->recalctm = nd6_recalc_reachtm_interval; /* reset */
282 }
283 }
284 if (nd_ra->nd_ra_retransmit)
285 ndi->retrans = ntohl(nd_ra->nd_ra_retransmit);
286 if (nd_ra->nd_ra_curhoplimit)
287 ndi->chlim = nd_ra->nd_ra_curhoplimit;
288 dr = defrtrlist_update(&dr0);
289 }
290
291 /*
292 * prefix
293 */
294 if (ndopts.nd_opts_pi) {
295 struct nd_opt_hdr *pt;
296 struct nd_opt_prefix_info *pi = NULL;
297 struct nd_prefixctl pr;
298
299 for (pt = (struct nd_opt_hdr *)ndopts.nd_opts_pi;
300 pt <= (struct nd_opt_hdr *)ndopts.nd_opts_pi_end;
301 pt = (struct nd_opt_hdr *)((caddr_t)pt +
302 (pt->nd_opt_len << 3))) {
303 if (pt->nd_opt_type != ND_OPT_PREFIX_INFORMATION)
304 continue;
305 pi = (struct nd_opt_prefix_info *)pt;
306
307 if (pi->nd_opt_pi_len != 4) {
308 nd6log((LOG_INFO,
309 "nd6_ra_input: invalid option "
310 "len %d for prefix information option, "
311 "ignored\n", pi->nd_opt_pi_len));
312 continue;
313 }
314
315 if (128 < pi->nd_opt_pi_prefix_len) {
316 nd6log((LOG_INFO,
317 "nd6_ra_input: invalid prefix "
318 "len %d for prefix information option, "
319 "ignored\n", pi->nd_opt_pi_prefix_len));
320 continue;
321 }
322
323 if (IN6_IS_ADDR_MULTICAST(&pi->nd_opt_pi_prefix)
324 || IN6_IS_ADDR_LINKLOCAL(&pi->nd_opt_pi_prefix)) {
325 nd6log((LOG_INFO,
326 "nd6_ra_input: invalid prefix "
327 "%s, ignored\n",
328 ip6_sprintf(ip6bufs,
329 &pi->nd_opt_pi_prefix)));
330 continue;
331 }
332
333 bzero(&pr, sizeof(pr));
334 pr.ndpr_prefix.sin6_family = AF_INET6;
335 pr.ndpr_prefix.sin6_len = sizeof(pr.ndpr_prefix);
336 pr.ndpr_prefix.sin6_addr = pi->nd_opt_pi_prefix;
337 pr.ndpr_ifp = (struct ifnet *)m->m_pkthdr.rcvif;
338
339 pr.ndpr_raf_onlink = (pi->nd_opt_pi_flags_reserved &
340 ND_OPT_PI_FLAG_ONLINK) ? 1 : 0;
341 pr.ndpr_raf_auto = (pi->nd_opt_pi_flags_reserved &
342 ND_OPT_PI_FLAG_AUTO) ? 1 : 0;
343 pr.ndpr_plen = pi->nd_opt_pi_prefix_len;
344 pr.ndpr_vltime = ntohl(pi->nd_opt_pi_valid_time);
345 pr.ndpr_pltime = ntohl(pi->nd_opt_pi_preferred_time);
346 (void)prelist_update(&pr, dr, m, mcast);
347 }
348 }
349
350 /*
351 * MTU
352 */
353 if (ndopts.nd_opts_mtu && ndopts.nd_opts_mtu->nd_opt_mtu_len == 1) {
354 u_long mtu;
355 u_long maxmtu;
356
357 mtu = (u_long)ntohl(ndopts.nd_opts_mtu->nd_opt_mtu_mtu);
358
359 /* lower bound */
360 if (mtu < IPV6_MMTU) {
361 nd6log((LOG_INFO, "nd6_ra_input: bogus mtu option "
362 "mtu=%lu sent from %s, ignoring\n",
363 mtu, ip6_sprintf(ip6bufs, &ip6->ip6_src)));
364 goto skip;
365 }
366
367 /* upper bound */
368 maxmtu = (ndi->maxmtu && ndi->maxmtu < ifp->if_mtu)
369 ? ndi->maxmtu : ifp->if_mtu;
370 if (mtu <= maxmtu) {
371 int change = (ndi->linkmtu != mtu);
372
373 ndi->linkmtu = mtu;
374 if (change) /* in6_maxmtu may change */
375 in6_setmaxmtu();
376 } else {
377 nd6log((LOG_INFO, "nd6_ra_input: bogus mtu "
378 "mtu=%lu sent from %s; "
379 "exceeds maxmtu %lu, ignoring\n",
380 mtu, ip6_sprintf(ip6bufs, &ip6->ip6_src), maxmtu));
381 }
382 }
383
384 skip:
385
386 /*
387 * Source link layer address
388 */
389 {
390 char *lladdr = NULL;
391 int lladdrlen = 0;
392
393 if (ndopts.nd_opts_src_lladdr) {
394 lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1);
395 lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3;
396 }
397
398 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
399 nd6log((LOG_INFO,
400 "nd6_ra_input: lladdrlen mismatch for %s "
401 "(if %d, RA packet %d)\n", ip6_sprintf(ip6bufs, &saddr6),
402 ifp->if_addrlen, lladdrlen - 2));
403 goto bad;
404 }
405
406 nd6_cache_lladdr(ifp, &saddr6, lladdr,
407 lladdrlen, ND_ROUTER_ADVERT, 0);
408
409 /*
410 * Installing a link-layer address might change the state of the
411 * router's neighbor cache, which might also affect our on-link
412 * detection of adveritsed prefixes.
413 */
414 pfxlist_onlink_check();
415 }
416
417 freeit:
418 m_freem(m);
419 return;
420
421 bad:
422 icmp6stat.icp6s_badra++;
423 m_freem(m);
424 }
425
426 /*
427 * default router list proccessing sub routines
428 */
429
430 /* tell the change to user processes watching the routing socket. */
431 static void
432 nd6_rtmsg(int cmd, struct rtentry *rt)
433 {
434 struct rt_addrinfo info;
435
436 bzero((caddr_t)&info, sizeof(info));
437 info.rti_info[RTAX_DST] = rt_key(rt);
438 info.rti_info[RTAX_GATEWAY] = rt->rt_gateway;
439 info.rti_info[RTAX_NETMASK] = rt_mask(rt);
440 if (rt->rt_ifp) {
441 info.rti_info[RTAX_IFP] =
442 TAILQ_FIRST(&rt->rt_ifp->if_addrlist)->ifa_addr;
443 info.rti_info[RTAX_IFA] = rt->rt_ifa->ifa_addr;
444 }
445
446 rt_missmsg(cmd, &info, rt->rt_flags, 0);
447 }
448
449 void
450 defrouter_addreq(struct nd_defrouter *new)
451 {
452 struct sockaddr_in6 def, mask, gate;
453 struct rtentry *newrt = NULL;
454 int s;
455 int error;
456
457 bzero(&def, sizeof(def));
458 bzero(&mask, sizeof(mask));
459 bzero(&gate, sizeof(gate));
460
461 def.sin6_len = mask.sin6_len = gate.sin6_len =
462 sizeof(struct sockaddr_in6);
463 def.sin6_family = gate.sin6_family = AF_INET6;
464 gate.sin6_addr = new->rtaddr;
465
466 s = splnet();
467 error = rtrequest(RTM_ADD, (struct sockaddr *)&def,
468 (struct sockaddr *)&gate, (struct sockaddr *)&mask,
469 RTF_GATEWAY, &newrt);
470 if (newrt) {
471 RT_LOCK(newrt);
472 nd6_rtmsg(RTM_ADD, newrt); /* tell user process */
473 RT_REMREF(newrt);
474 RT_UNLOCK(newrt);
475 }
476 if (error == 0)
477 new->installed = 1;
478 splx(s);
479 return;
480 }
481
482 struct nd_defrouter *
483 defrouter_lookup(struct in6_addr *addr, struct ifnet *ifp)
484 {
485 struct nd_defrouter *dr;
486
487 for (dr = TAILQ_FIRST(&nd_defrouter); dr;
488 dr = TAILQ_NEXT(dr, dr_entry)) {
489 if (dr->ifp == ifp && IN6_ARE_ADDR_EQUAL(addr, &dr->rtaddr))
490 return (dr);
491 }
492
493 return (NULL); /* search failed */
494 }
495
496 /*
497 * Remove the default route for a given router.
498 * This is just a subroutine function for defrouter_select(), and should
499 * not be called from anywhere else.
500 */
501 static void
502 defrouter_delreq(struct nd_defrouter *dr)
503 {
504 struct sockaddr_in6 def, mask, gate;
505 struct rtentry *oldrt = NULL;
506
507 bzero(&def, sizeof(def));
508 bzero(&mask, sizeof(mask));
509 bzero(&gate, sizeof(gate));
510
511 def.sin6_len = mask.sin6_len = gate.sin6_len =
512 sizeof(struct sockaddr_in6);
513 def.sin6_family = gate.sin6_family = AF_INET6;
514 gate.sin6_addr = dr->rtaddr;
515
516 rtrequest(RTM_DELETE, (struct sockaddr *)&def,
517 (struct sockaddr *)&gate,
518 (struct sockaddr *)&mask, RTF_GATEWAY, &oldrt);
519 if (oldrt) {
520 nd6_rtmsg(RTM_DELETE, oldrt);
521 RTFREE(oldrt);
522 }
523
524 dr->installed = 0;
525 }
526
527 /*
528 * remove all default routes from default router list
529 */
530 void
531 defrouter_reset(void)
532 {
533 struct nd_defrouter *dr;
534
535 for (dr = TAILQ_FIRST(&nd_defrouter); dr;
536 dr = TAILQ_NEXT(dr, dr_entry))
537 defrouter_delreq(dr);
538
539 /*
540 * XXX should we also nuke any default routers in the kernel, by
541 * going through them by rtalloc1()?
542 */
543 }
544
545 void
546 defrtrlist_del(struct nd_defrouter *dr)
547 {
548 struct nd_defrouter *deldr = NULL;
549 struct nd_prefix *pr;
550
551 /*
552 * Flush all the routing table entries that use the router
553 * as a next hop.
554 */
555 if (!ip6_forwarding && ip6_accept_rtadv) /* XXX: better condition? */
556 rt6_flush(&dr->rtaddr, dr->ifp);
557
558 if (dr->installed) {
559 deldr = dr;
560 defrouter_delreq(dr);
561 }
562 TAILQ_REMOVE(&nd_defrouter, dr, dr_entry);
563
564 /*
565 * Also delete all the pointers to the router in each prefix lists.
566 */
567 for (pr = nd_prefix.lh_first; pr; pr = pr->ndpr_next) {
568 struct nd_pfxrouter *pfxrtr;
569 if ((pfxrtr = pfxrtr_lookup(pr, dr)) != NULL)
570 pfxrtr_del(pfxrtr);
571 }
572 pfxlist_onlink_check();
573
574 /*
575 * If the router is the primary one, choose a new one.
576 * Note that defrouter_select() will remove the current gateway
577 * from the routing table.
578 */
579 if (deldr)
580 defrouter_select();
581
582 free(dr, M_IP6NDP);
583 }
584
585 /*
586 * Default Router Selection according to Section 6.3.6 of RFC 2461 and
587 * draft-ietf-ipngwg-router-selection:
588 * 1) Routers that are reachable or probably reachable should be preferred.
589 * If we have more than one (probably) reachable router, prefer ones
590 * with the highest router preference.
591 * 2) When no routers on the list are known to be reachable or
592 * probably reachable, routers SHOULD be selected in a round-robin
593 * fashion, regardless of router preference values.
594 * 3) If the Default Router List is empty, assume that all
595 * destinations are on-link.
596 *
597 * We assume nd_defrouter is sorted by router preference value.
598 * Since the code below covers both with and without router preference cases,
599 * we do not need to classify the cases by ifdef.
600 *
601 * At this moment, we do not try to install more than one default router,
602 * even when the multipath routing is available, because we're not sure about
603 * the benefits for stub hosts comparing to the risk of making the code
604 * complicated and the possibility of introducing bugs.
605 */
606 void
607 defrouter_select(void)
608 {
609 int s = splnet();
610 struct nd_defrouter *dr, *selected_dr = NULL, *installed_dr = NULL;
611 struct rtentry *rt = NULL;
612 struct llinfo_nd6 *ln = NULL;
613
614 /*
615 * This function should be called only when acting as an autoconfigured
616 * host. Although the remaining part of this function is not effective
617 * if the node is not an autoconfigured host, we explicitly exclude
618 * such cases here for safety.
619 */
620 if (ip6_forwarding || !ip6_accept_rtadv) {
621 nd6log((LOG_WARNING,
622 "defrouter_select: called unexpectedly (forwarding=%d, "
623 "accept_rtadv=%d)\n", ip6_forwarding, ip6_accept_rtadv));
624 splx(s);
625 return;
626 }
627
628 /*
629 * Let's handle easy case (3) first:
630 * If default router list is empty, there's nothing to be done.
631 */
632 if (!TAILQ_FIRST(&nd_defrouter)) {
633 splx(s);
634 return;
635 }
636
637 /*
638 * Search for a (probably) reachable router from the list.
639 * We just pick up the first reachable one (if any), assuming that
640 * the ordering rule of the list described in defrtrlist_update().
641 */
642 for (dr = TAILQ_FIRST(&nd_defrouter); dr;
643 dr = TAILQ_NEXT(dr, dr_entry)) {
644 if (selected_dr == NULL &&
645 (rt = nd6_lookup(&dr->rtaddr, 0, dr->ifp)) &&
646 (ln = (struct llinfo_nd6 *)rt->rt_llinfo) &&
647 ND6_IS_LLINFO_PROBREACH(ln)) {
648 selected_dr = dr;
649 }
650
651 if (dr->installed && installed_dr == NULL)
652 installed_dr = dr;
653 else if (dr->installed && installed_dr) {
654 /* this should not happen. warn for diagnosis. */
655 log(LOG_ERR, "defrouter_select: more than one router"
656 " is installed\n");
657 }
658 }
659 /*
660 * If none of the default routers was found to be reachable,
661 * round-robin the list regardless of preference.
662 * Otherwise, if we have an installed router, check if the selected
663 * (reachable) router should really be preferred to the installed one.
664 * We only prefer the new router when the old one is not reachable
665 * or when the new one has a really higher preference value.
666 */
667 if (selected_dr == NULL) {
668 if (installed_dr == NULL || !TAILQ_NEXT(installed_dr, dr_entry))
669 selected_dr = TAILQ_FIRST(&nd_defrouter);
670 else
671 selected_dr = TAILQ_NEXT(installed_dr, dr_entry);
672 } else if (installed_dr &&
673 (rt = nd6_lookup(&installed_dr->rtaddr, 0, installed_dr->ifp)) &&
674 (ln = (struct llinfo_nd6 *)rt->rt_llinfo) &&
675 ND6_IS_LLINFO_PROBREACH(ln) &&
676 rtpref(selected_dr) <= rtpref(installed_dr)) {
677 selected_dr = installed_dr;
678 }
679
680 /*
681 * If the selected router is different than the installed one,
682 * remove the installed router and install the selected one.
683 * Note that the selected router is never NULL here.
684 */
685 if (installed_dr != selected_dr) {
686 if (installed_dr)
687 defrouter_delreq(installed_dr);
688 defrouter_addreq(selected_dr);
689 }
690
691 splx(s);
692 return;
693 }
694
695 /*
696 * for default router selection
697 * regards router-preference field as a 2-bit signed integer
698 */
699 static int
700 rtpref(struct nd_defrouter *dr)
701 {
702 switch (dr->flags & ND_RA_FLAG_RTPREF_MASK) {
703 case ND_RA_FLAG_RTPREF_HIGH:
704 return (RTPREF_HIGH);
705 case ND_RA_FLAG_RTPREF_MEDIUM:
706 case ND_RA_FLAG_RTPREF_RSV:
707 return (RTPREF_MEDIUM);
708 case ND_RA_FLAG_RTPREF_LOW:
709 return (RTPREF_LOW);
710 default:
711 /*
712 * This case should never happen. If it did, it would mean a
713 * serious bug of kernel internal. We thus always bark here.
714 * Or, can we even panic?
715 */
716 log(LOG_ERR, "rtpref: impossible RA flag %x\n", dr->flags);
717 return (RTPREF_INVALID);
718 }
719 /* NOTREACHED */
720 }
721
722 static struct nd_defrouter *
723 defrtrlist_update(struct nd_defrouter *new)
724 {
725 struct nd_defrouter *dr, *n;
726 int s = splnet();
727
728 if ((dr = defrouter_lookup(&new->rtaddr, new->ifp)) != NULL) {
729 /* entry exists */
730 if (new->rtlifetime == 0) {
731 defrtrlist_del(dr);
732 dr = NULL;
733 } else {
734 int oldpref = rtpref(dr);
735
736 /* override */
737 dr->flags = new->flags; /* xxx flag check */
738 dr->rtlifetime = new->rtlifetime;
739 dr->expire = new->expire;
740
741 /*
742 * If the preference does not change, there's no need
743 * to sort the entries.
744 */
745 if (rtpref(new) == oldpref) {
746 splx(s);
747 return (dr);
748 }
749
750 /*
751 * preferred router may be changed, so relocate
752 * this router.
753 * XXX: calling TAILQ_REMOVE directly is a bad manner.
754 * However, since defrtrlist_del() has many side
755 * effects, we intentionally do so here.
756 * defrouter_select() below will handle routing
757 * changes later.
758 */
759 TAILQ_REMOVE(&nd_defrouter, dr, dr_entry);
760 n = dr;
761 goto insert;
762 }
763 splx(s);
764 return (dr);
765 }
766
767 /* entry does not exist */
768 if (new->rtlifetime == 0) {
769 splx(s);
770 return (NULL);
771 }
772
773 n = (struct nd_defrouter *)malloc(sizeof(*n), M_IP6NDP, M_NOWAIT);
774 if (n == NULL) {
775 splx(s);
776 return (NULL);
777 }
778 bzero(n, sizeof(*n));
779 *n = *new;
780
781 insert:
782 /*
783 * Insert the new router in the Default Router List;
784 * The Default Router List should be in the descending order
785 * of router-preferece. Routers with the same preference are
786 * sorted in the arriving time order.
787 */
788
789 /* insert at the end of the group */
790 for (dr = TAILQ_FIRST(&nd_defrouter); dr;
791 dr = TAILQ_NEXT(dr, dr_entry)) {
792 if (rtpref(n) > rtpref(dr))
793 break;
794 }
795 if (dr)
796 TAILQ_INSERT_BEFORE(dr, n, dr_entry);
797 else
798 TAILQ_INSERT_TAIL(&nd_defrouter, n, dr_entry);
799
800 defrouter_select();
801
802 splx(s);
803
804 return (n);
805 }
806
807 static struct nd_pfxrouter *
808 pfxrtr_lookup(struct nd_prefix *pr, struct nd_defrouter *dr)
809 {
810 struct nd_pfxrouter *search;
811
812 for (search = pr->ndpr_advrtrs.lh_first; search; search = search->pfr_next) {
813 if (search->router == dr)
814 break;
815 }
816
817 return (search);
818 }
819
820 static void
821 pfxrtr_add(struct nd_prefix *pr, struct nd_defrouter *dr)
822 {
823 struct nd_pfxrouter *new;
824
825 new = (struct nd_pfxrouter *)malloc(sizeof(*new), M_IP6NDP, M_NOWAIT);
826 if (new == NULL)
827 return;
828 bzero(new, sizeof(*new));
829 new->router = dr;
830
831 LIST_INSERT_HEAD(&pr->ndpr_advrtrs, new, pfr_entry);
832
833 pfxlist_onlink_check();
834 }
835
836 static void
837 pfxrtr_del(struct nd_pfxrouter *pfr)
838 {
839 LIST_REMOVE(pfr, pfr_entry);
840 free(pfr, M_IP6NDP);
841 }
842
843 struct nd_prefix *
844 nd6_prefix_lookup(struct nd_prefixctl *key)
845 {
846 struct nd_prefix *search;
847
848 for (search = nd_prefix.lh_first; search; search = search->ndpr_next) {
849 if (key->ndpr_ifp == search->ndpr_ifp &&
850 key->ndpr_plen == search->ndpr_plen &&
851 in6_are_prefix_equal(&key->ndpr_prefix.sin6_addr,
852 &search->ndpr_prefix.sin6_addr, key->ndpr_plen)) {
853 break;
854 }
855 }
856
857 return (search);
858 }
859
860 int
861 nd6_prelist_add(struct nd_prefixctl *pr, struct nd_defrouter *dr,
862 struct nd_prefix **newp)
863 {
864 struct nd_prefix *new = NULL;
865 int error = 0;
866 int i, s;
867 char ip6buf[INET6_ADDRSTRLEN];
868
869 new = (struct nd_prefix *)malloc(sizeof(*new), M_IP6NDP, M_NOWAIT);
870 if (new == NULL)
871 return(ENOMEM);
872 bzero(new, sizeof(*new));
873 new->ndpr_ifp = pr->ndpr_ifp;
874 new->ndpr_prefix = pr->ndpr_prefix;
875 new->ndpr_plen = pr->ndpr_plen;
876 new->ndpr_vltime = pr->ndpr_vltime;
877 new->ndpr_pltime = pr->ndpr_pltime;
878 new->ndpr_flags = pr->ndpr_flags;
879 if ((error = in6_init_prefix_ltimes(new)) != 0) {
880 free(new, M_IP6NDP);
881 return(error);
882 }
883 new->ndpr_lastupdate = time_second;
884 if (newp != NULL)
885 *newp = new;
886
887 /* initialization */
888 LIST_INIT(&new->ndpr_advrtrs);
889 in6_prefixlen2mask(&new->ndpr_mask, new->ndpr_plen);
890 /* make prefix in the canonical form */
891 for (i = 0; i < 4; i++)
892 new->ndpr_prefix.sin6_addr.s6_addr32[i] &=
893 new->ndpr_mask.s6_addr32[i];
894
895 s = splnet();
896 /* link ndpr_entry to nd_prefix list */
897 LIST_INSERT_HEAD(&nd_prefix, new, ndpr_entry);
898 splx(s);
899
900 /* ND_OPT_PI_FLAG_ONLINK processing */
901 if (new->ndpr_raf_onlink) {
902 int e;
903
904 if ((e = nd6_prefix_onlink(new)) != 0) {
905 nd6log((LOG_ERR, "nd6_prelist_add: failed to make "
906 "the prefix %s/%d on-link on %s (errno=%d)\n",
907 ip6_sprintf(ip6buf, &pr->ndpr_prefix.sin6_addr),
908 pr->ndpr_plen, if_name(pr->ndpr_ifp), e));
909 /* proceed anyway. XXX: is it correct? */
910 }
911 }
912
913 if (dr)
914 pfxrtr_add(new, dr);
915
916 return 0;
917 }
918
919 void
920 prelist_remove(struct nd_prefix *pr)
921 {
922 struct nd_pfxrouter *pfr, *next;
923 int e, s;
924 char ip6buf[INET6_ADDRSTRLEN];
925
926 /* make sure to invalidate the prefix until it is really freed. */
927 pr->ndpr_vltime = 0;
928 pr->ndpr_pltime = 0;
929
930 /*
931 * Though these flags are now meaningless, we'd rather keep the value
932 * of pr->ndpr_raf_onlink and pr->ndpr_raf_auto not to confuse users
933 * when executing "ndp -p".
934 */
935
936 if ((pr->ndpr_stateflags & NDPRF_ONLINK) != 0 &&
937 (e = nd6_prefix_offlink(pr)) != 0) {
938 nd6log((LOG_ERR, "prelist_remove: failed to make %s/%d offlink "
939 "on %s, errno=%d\n",
940 ip6_sprintf(ip6buf, &pr->ndpr_prefix.sin6_addr),
941 pr->ndpr_plen, if_name(pr->ndpr_ifp), e));
942 /* what should we do? */
943 }
944
945 if (pr->ndpr_refcnt > 0)
946 return; /* notice here? */
947
948 s = splnet();
949
950 /* unlink ndpr_entry from nd_prefix list */
951 LIST_REMOVE(pr, ndpr_entry);
952
953 /* free list of routers that adversed the prefix */
954 for (pfr = pr->ndpr_advrtrs.lh_first; pfr; pfr = next) {
955 next = pfr->pfr_next;
956
957 free(pfr, M_IP6NDP);
958 }
959 splx(s);
960
961 free(pr, M_IP6NDP);
962
963 pfxlist_onlink_check();
964 }
965
966 /*
967 * dr - may be NULL
968 */
969
970 static int
971 prelist_update(struct nd_prefixctl *new, struct nd_defrouter *dr,
972 struct mbuf *m, int mcast)
973 {
974 struct in6_ifaddr *ia6 = NULL, *ia6_match = NULL;
975 struct ifaddr *ifa;
976 struct ifnet *ifp = new->ndpr_ifp;
977 struct nd_prefix *pr;
978 int s = splnet();
979 int error = 0;
980 int newprefix = 0;
981 int auth;
982 struct in6_addrlifetime lt6_tmp;
983 char ip6buf[INET6_ADDRSTRLEN];
984
985 auth = 0;
986 if (m) {
987 /*
988 * Authenticity for NA consists authentication for
989 * both IP header and IP datagrams, doesn't it ?
990 */
991 #if defined(M_AUTHIPHDR) && defined(M_AUTHIPDGM)
992 auth = ((m->m_flags & M_AUTHIPHDR) &&
993 (m->m_flags & M_AUTHIPDGM));
994 #endif
995 }
996
997 if ((pr = nd6_prefix_lookup(new)) != NULL) {
998 /*
999 * nd6_prefix_lookup() ensures that pr and new have the same
1000 * prefix on a same interface.
1001 */
1002
1003 /*
1004 * Update prefix information. Note that the on-link (L) bit
1005 * and the autonomous (A) bit should NOT be changed from 1
1006 * to 0.
1007 */
1008 if (new->ndpr_raf_onlink == 1)
1009 pr->ndpr_raf_onlink = 1;
1010 if (new->ndpr_raf_auto == 1)
1011 pr->ndpr_raf_auto = 1;
1012 if (new->ndpr_raf_onlink) {
1013 pr->ndpr_vltime = new->ndpr_vltime;
1014 pr->ndpr_pltime = new->ndpr_pltime;
1015 (void)in6_init_prefix_ltimes(pr); /* XXX error case? */
1016 pr->ndpr_lastupdate = time_second;
1017 }
1018
1019 if (new->ndpr_raf_onlink &&
1020 (pr->ndpr_stateflags & NDPRF_ONLINK) == 0) {
1021 int e;
1022
1023 if ((e = nd6_prefix_onlink(pr)) != 0) {
1024 nd6log((LOG_ERR,
1025 "prelist_update: failed to make "
1026 "the prefix %s/%d on-link on %s "
1027 "(errno=%d)\n",
1028 ip6_sprintf(ip6buf,
1029 &pr->ndpr_prefix.sin6_addr),
1030 pr->ndpr_plen, if_name(pr->ndpr_ifp), e));
1031 /* proceed anyway. XXX: is it correct? */
1032 }
1033 }
1034
1035 if (dr && pfxrtr_lookup(pr, dr) == NULL)
1036 pfxrtr_add(pr, dr);
1037 } else {
1038 struct nd_prefix *newpr = NULL;
1039
1040 newprefix = 1;
1041
1042 if (new->ndpr_vltime == 0)
1043 goto end;
1044 if (new->ndpr_raf_onlink == 0 && new->ndpr_raf_auto == 0)
1045 goto end;
1046
1047 error = nd6_prelist_add(new, dr, &newpr);
1048 if (error != 0 || newpr == NULL) {
1049 nd6log((LOG_NOTICE, "prelist_update: "
1050 "nd6_prelist_add failed for %s/%d on %s "
1051 "errno=%d, returnpr=%p\n",
1052 ip6_sprintf(ip6buf, &new->ndpr_prefix.sin6_addr),
1053 new->ndpr_plen, if_name(new->ndpr_ifp),
1054 error, newpr));
1055 goto end; /* we should just give up in this case. */
1056 }
1057
1058 /*
1059 * XXX: from the ND point of view, we can ignore a prefix
1060 * with the on-link bit being zero. However, we need a
1061 * prefix structure for references from autoconfigured
1062 * addresses. Thus, we explicitly make sure that the prefix
1063 * itself expires now.
1064 */
1065 if (newpr->ndpr_raf_onlink == 0) {
1066 newpr->ndpr_vltime = 0;
1067 newpr->ndpr_pltime = 0;
1068 in6_init_prefix_ltimes(newpr);
1069 }
1070
1071 pr = newpr;
1072 }
1073
1074 /*
1075 * Address autoconfiguration based on Section 5.5.3 of RFC 2462.
1076 * Note that pr must be non NULL at this point.
1077 */
1078
1079 /* 5.5.3 (a). Ignore the prefix without the A bit set. */
1080 if (!new->ndpr_raf_auto)
1081 goto end;
1082
1083 /*
1084 * 5.5.3 (b). the link-local prefix should have been ignored in
1085 * nd6_ra_input.
1086 */
1087
1088 /* 5.5.3 (c). Consistency check on lifetimes: pltime <= vltime. */
1089 if (new->ndpr_pltime > new->ndpr_vltime) {
1090 error = EINVAL; /* XXX: won't be used */
1091 goto end;
1092 }
1093
1094 /*
1095 * 5.5.3 (d). If the prefix advertised is not equal to the prefix of
1096 * an address configured by stateless autoconfiguration already in the
1097 * list of addresses associated with the interface, and the Valid
1098 * Lifetime is not 0, form an address. We first check if we have
1099 * a matching prefix.
1100 * Note: we apply a clarification in rfc2462bis-02 here. We only
1101 * consider autoconfigured addresses while RFC2462 simply said
1102 * "address".
1103 */
1104 TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) {
1105 struct in6_ifaddr *ifa6;
1106 u_int32_t remaininglifetime;
1107
1108 if (ifa->ifa_addr->sa_family != AF_INET6)
1109 continue;
1110
1111 ifa6 = (struct in6_ifaddr *)ifa;
1112
1113 /*
1114 * We only consider autoconfigured addresses as per rfc2462bis.
1115 */
1116 if (!(ifa6->ia6_flags & IN6_IFF_AUTOCONF))
1117 continue;
1118
1119 /*
1120 * Spec is not clear here, but I believe we should concentrate
1121 * on unicast (i.e. not anycast) addresses.
1122 * XXX: other ia6_flags? detached or duplicated?
1123 */
1124 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0)
1125 continue;
1126
1127 /*
1128 * Ignore the address if it is not associated with a prefix
1129 * or is associated with a prefix that is different from this
1130 * one. (pr is never NULL here)
1131 */
1132 if (ifa6->ia6_ndpr != pr)
1133 continue;
1134
1135 if (ia6_match == NULL) /* remember the first one */
1136 ia6_match = ifa6;
1137
1138 /*
1139 * An already autoconfigured address matched. Now that we
1140 * are sure there is at least one matched address, we can
1141 * proceed to 5.5.3. (e): update the lifetimes according to the
1142 * "two hours" rule and the privacy extension.
1143 * We apply some clarifications in rfc2462bis:
1144 * - use remaininglifetime instead of storedlifetime as a
1145 * variable name
1146 * - remove the dead code in the "two-hour" rule
1147 */
1148 #define TWOHOUR (120*60)
1149 lt6_tmp = ifa6->ia6_lifetime;
1150
1151 if (lt6_tmp.ia6t_vltime == ND6_INFINITE_LIFETIME)
1152 remaininglifetime = ND6_INFINITE_LIFETIME;
1153 else if (time_second - ifa6->ia6_updatetime >
1154 lt6_tmp.ia6t_vltime) {
1155 /*
1156 * The case of "invalid" address. We should usually
1157 * not see this case.
1158 */
1159 remaininglifetime = 0;
1160 } else
1161 remaininglifetime = lt6_tmp.ia6t_vltime -
1162 (time_second - ifa6->ia6_updatetime);
1163
1164 /* when not updating, keep the current stored lifetime. */
1165 lt6_tmp.ia6t_vltime = remaininglifetime;
1166
1167 if (TWOHOUR < new->ndpr_vltime ||
1168 remaininglifetime < new->ndpr_vltime) {
1169 lt6_tmp.ia6t_vltime = new->ndpr_vltime;
1170 } else if (remaininglifetime <= TWOHOUR) {
1171 if (auth) {
1172 lt6_tmp.ia6t_vltime = new->ndpr_vltime;
1173 }
1174 } else {
1175 /*
1176 * new->ndpr_vltime <= TWOHOUR &&
1177 * TWOHOUR < remaininglifetime
1178 */
1179 lt6_tmp.ia6t_vltime = TWOHOUR;
1180 }
1181
1182 /* The 2 hour rule is not imposed for preferred lifetime. */
1183 lt6_tmp.ia6t_pltime = new->ndpr_pltime;
1184
1185 in6_init_address_ltimes(pr, <6_tmp);
1186
1187 /*
1188 * We need to treat lifetimes for temporary addresses
1189 * differently, according to
1190 * draft-ietf-ipv6-privacy-addrs-v2-01.txt 3.3 (1);
1191 * we only update the lifetimes when they are in the maximum
1192 * intervals.
1193 */
1194 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0) {
1195 u_int32_t maxvltime, maxpltime;
1196
1197 if (ip6_temp_valid_lifetime >
1198 (u_int32_t)((time_second - ifa6->ia6_createtime) +
1199 ip6_desync_factor)) {
1200 maxvltime = ip6_temp_valid_lifetime -
1201 (time_second - ifa6->ia6_createtime) -
1202 ip6_desync_factor;
1203 } else
1204 maxvltime = 0;
1205 if (ip6_temp_preferred_lifetime >
1206 (u_int32_t)((time_second - ifa6->ia6_createtime) +
1207 ip6_desync_factor)) {
1208 maxpltime = ip6_temp_preferred_lifetime -
1209 (time_second - ifa6->ia6_createtime) -
1210 ip6_desync_factor;
1211 } else
1212 maxpltime = 0;
1213
1214 if (lt6_tmp.ia6t_vltime == ND6_INFINITE_LIFETIME ||
1215 lt6_tmp.ia6t_vltime > maxvltime) {
1216 lt6_tmp.ia6t_vltime = maxvltime;
1217 }
1218 if (lt6_tmp.ia6t_pltime == ND6_INFINITE_LIFETIME ||
1219 lt6_tmp.ia6t_pltime > maxpltime) {
1220 lt6_tmp.ia6t_pltime = maxpltime;
1221 }
1222 }
1223 ifa6->ia6_lifetime = lt6_tmp;
1224 ifa6->ia6_updatetime = time_second;
1225 }
1226 if (ia6_match == NULL && new->ndpr_vltime) {
1227 int ifidlen;
1228
1229 /*
1230 * 5.5.3 (d) (continued)
1231 * No address matched and the valid lifetime is non-zero.
1232 * Create a new address.
1233 */
1234
1235 /*
1236 * Prefix Length check:
1237 * If the sum of the prefix length and interface identifier
1238 * length does not equal 128 bits, the Prefix Information
1239 * option MUST be ignored. The length of the interface
1240 * identifier is defined in a separate link-type specific
1241 * document.
1242 */
1243 ifidlen = in6_if2idlen(ifp);
1244 if (ifidlen < 0) {
1245 /* this should not happen, so we always log it. */
1246 log(LOG_ERR, "prelist_update: IFID undefined (%s)\n",
1247 if_name(ifp));
1248 goto end;
1249 }
1250 if (ifidlen + pr->ndpr_plen != 128) {
1251 nd6log((LOG_INFO,
1252 "prelist_update: invalid prefixlen "
1253 "%d for %s, ignored\n",
1254 pr->ndpr_plen, if_name(ifp)));
1255 goto end;
1256 }
1257
1258 if ((ia6 = in6_ifadd(new, mcast)) != NULL) {
1259 /*
1260 * note that we should use pr (not new) for reference.
1261 */
1262 pr->ndpr_refcnt++;
1263 ia6->ia6_ndpr = pr;
1264
1265 /*
1266 * RFC 3041 3.3 (2).
1267 * When a new public address is created as described
1268 * in RFC2462, also create a new temporary address.
1269 *
1270 * RFC 3041 3.5.
1271 * When an interface connects to a new link, a new
1272 * randomized interface identifier should be generated
1273 * immediately together with a new set of temporary
1274 * addresses. Thus, we specifiy 1 as the 2nd arg of
1275 * in6_tmpifadd().
1276 */
1277 if (ip6_use_tempaddr) {
1278 int e;
1279 if ((e = in6_tmpifadd(ia6, 1, 1)) != 0) {
1280 nd6log((LOG_NOTICE, "prelist_update: "
1281 "failed to create a temporary "
1282 "address, errno=%d\n",
1283 e));
1284 }
1285 }
1286
1287 /*
1288 * A newly added address might affect the status
1289 * of other addresses, so we check and update it.
1290 * XXX: what if address duplication happens?
1291 */
1292 pfxlist_onlink_check();
1293 } else {
1294 /* just set an error. do not bark here. */
1295 error = EADDRNOTAVAIL; /* XXX: might be unused. */
1296 }
1297 }
1298
1299 end:
1300 splx(s);
1301 return error;
1302 }
1303
1304 /*
1305 * A supplement function used in the on-link detection below;
1306 * detect if a given prefix has a (probably) reachable advertising router.
1307 * XXX: lengthy function name...
1308 */
1309 static struct nd_pfxrouter *
1310 find_pfxlist_reachable_router(struct nd_prefix *pr)
1311 {
1312 struct nd_pfxrouter *pfxrtr;
1313 struct rtentry *rt;
1314 struct llinfo_nd6 *ln;
1315
1316 for (pfxrtr = LIST_FIRST(&pr->ndpr_advrtrs); pfxrtr;
1317 pfxrtr = LIST_NEXT(pfxrtr, pfr_entry)) {
1318 if ((rt = nd6_lookup(&pfxrtr->router->rtaddr, 0,
1319 pfxrtr->router->ifp)) &&
1320 (ln = (struct llinfo_nd6 *)rt->rt_llinfo) &&
1321 ND6_IS_LLINFO_PROBREACH(ln))
1322 break; /* found */
1323 }
1324
1325 return (pfxrtr);
1326 }
1327
1328 /*
1329 * Check if each prefix in the prefix list has at least one available router
1330 * that advertised the prefix (a router is "available" if its neighbor cache
1331 * entry is reachable or probably reachable).
1332 * If the check fails, the prefix may be off-link, because, for example,
1333 * we have moved from the network but the lifetime of the prefix has not
1334 * expired yet. So we should not use the prefix if there is another prefix
1335 * that has an available router.
1336 * But, if there is no prefix that has an available router, we still regards
1337 * all the prefixes as on-link. This is because we can't tell if all the
1338 * routers are simply dead or if we really moved from the network and there
1339 * is no router around us.
1340 */
1341 void
1342 pfxlist_onlink_check()
1343 {
1344 struct nd_prefix *pr;
1345 struct in6_ifaddr *ifa;
1346 struct nd_defrouter *dr;
1347 struct nd_pfxrouter *pfxrtr = NULL;
1348
1349 /*
1350 * Check if there is a prefix that has a reachable advertising
1351 * router.
1352 */
1353 for (pr = nd_prefix.lh_first; pr; pr = pr->ndpr_next) {
1354 if (pr->ndpr_raf_onlink && find_pfxlist_reachable_router(pr))
1355 break;
1356 }
1357
1358 /*
1359 * If we have no such prefix, check whether we still have a router
1360 * that does not advertise any prefixes.
1361 */
1362 if (pr == NULL) {
1363 for (dr = TAILQ_FIRST(&nd_defrouter); dr;
1364 dr = TAILQ_NEXT(dr, dr_entry)) {
1365 struct nd_prefix *pr0;
1366
1367 for (pr0 = nd_prefix.lh_first; pr0;
1368 pr0 = pr0->ndpr_next) {
1369 if ((pfxrtr = pfxrtr_lookup(pr0, dr)) != NULL)
1370 break;
1371 }
1372 if (pfxrtr != NULL)
1373 break;
1374 }
1375 }
1376 if (pr != NULL || (TAILQ_FIRST(&nd_defrouter) && pfxrtr == NULL)) {
1377 /*
1378 * There is at least one prefix that has a reachable router,
1379 * or at least a router which probably does not advertise
1380 * any prefixes. The latter would be the case when we move
1381 * to a new link where we have a router that does not provide
1382 * prefixes and we configure an address by hand.
1383 * Detach prefixes which have no reachable advertising
1384 * router, and attach other prefixes.
1385 */
1386 for (pr = nd_prefix.lh_first; pr; pr = pr->ndpr_next) {
1387 /* XXX: a link-local prefix should never be detached */
1388 if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr))
1389 continue;
1390
1391 /*
1392 * we aren't interested in prefixes without the L bit
1393 * set.
1394 */
1395 if (pr->ndpr_raf_onlink == 0)
1396 continue;
1397
1398 if ((pr->ndpr_stateflags & NDPRF_DETACHED) == 0 &&
1399 find_pfxlist_reachable_router(pr) == NULL)
1400 pr->ndpr_stateflags |= NDPRF_DETACHED;
1401 if ((pr->ndpr_stateflags & NDPRF_DETACHED) != 0 &&
1402 find_pfxlist_reachable_router(pr) != 0)
1403 pr->ndpr_stateflags &= ~NDPRF_DETACHED;
1404 }
1405 } else {
1406 /* there is no prefix that has a reachable router */
1407 for (pr = nd_prefix.lh_first; pr; pr = pr->ndpr_next) {
1408 if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr))
1409 continue;
1410
1411 if (pr->ndpr_raf_onlink == 0)
1412 continue;
1413
1414 if ((pr->ndpr_stateflags & NDPRF_DETACHED) != 0)
1415 pr->ndpr_stateflags &= ~NDPRF_DETACHED;
1416 }
1417 }
1418
1419 /*
1420 * Remove each interface route associated with a (just) detached
1421 * prefix, and reinstall the interface route for a (just) attached
1422 * prefix. Note that all attempt of reinstallation does not
1423 * necessarily success, when a same prefix is shared among multiple
1424 * interfaces. Such cases will be handled in nd6_prefix_onlink,
1425 * so we don't have to care about them.
1426 */
1427 for (pr = nd_prefix.lh_first; pr; pr = pr->ndpr_next) {
1428 int e;
1429 char ip6buf[INET6_ADDRSTRLEN];
1430
1431 if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr))
1432 continue;
1433
1434 if (pr->ndpr_raf_onlink == 0)
1435 continue;
1436
1437 if ((pr->ndpr_stateflags & NDPRF_DETACHED) != 0 &&
1438 (pr->ndpr_stateflags & NDPRF_ONLINK) != 0) {
1439 if ((e = nd6_prefix_offlink(pr)) != 0) {
1440 nd6log((LOG_ERR,
1441 "pfxlist_onlink_check: failed to "
1442 "make %s/%d offlink, errno=%d\n",
1443 ip6_sprintf(ip6buf,
1444 &pr->ndpr_prefix.sin6_addr),
1445 pr->ndpr_plen, e));
1446 }
1447 }
1448 if ((pr->ndpr_stateflags & NDPRF_DETACHED) == 0 &&
1449 (pr->ndpr_stateflags & NDPRF_ONLINK) == 0 &&
1450 pr->ndpr_raf_onlink) {
1451 if ((e = nd6_prefix_onlink(pr)) != 0) {
1452 nd6log((LOG_ERR,
1453 "pfxlist_onlink_check: failed to "
1454 "make %s/%d onlink, errno=%d\n",
1455 ip6_sprintf(ip6buf,
1456 &pr->ndpr_prefix.sin6_addr),
1457 pr->ndpr_plen, e));
1458 }
1459 }
1460 }
1461
1462 /*
1463 * Changes on the prefix status might affect address status as well.
1464 * Make sure that all addresses derived from an attached prefix are
1465 * attached, and that all addresses derived from a detached prefix are
1466 * detached. Note, however, that a manually configured address should
1467 * always be attached.
1468 * The precise detection logic is same as the one for prefixes.
1469 */
1470 for (ifa = in6_ifaddr; ifa; ifa = ifa->ia_next) {
1471 if (!(ifa->ia6_flags & IN6_IFF_AUTOCONF))
1472 continue;
1473
1474 if (ifa->ia6_ndpr == NULL) {
1475 /*
1476 * This can happen when we first configure the address
1477 * (i.e. the address exists, but the prefix does not).
1478 * XXX: complicated relationships...
1479 */
1480 continue;
1481 }
1482
1483 if (find_pfxlist_reachable_router(ifa->ia6_ndpr))
1484 break;
1485 }
1486 if (ifa) {
1487 for (ifa = in6_ifaddr; ifa; ifa = ifa->ia_next) {
1488 if ((ifa->ia6_flags & IN6_IFF_AUTOCONF) == 0)
1489 continue;
1490
1491 if (ifa->ia6_ndpr == NULL) /* XXX: see above. */
1492 continue;
1493
1494 if (find_pfxlist_reachable_router(ifa->ia6_ndpr)) {
1495 if (ifa->ia6_flags & IN6_IFF_DETACHED) {
1496 ifa->ia6_flags &= ~IN6_IFF_DETACHED;
1497 ifa->ia6_flags |= IN6_IFF_TENTATIVE;
1498 nd6_dad_start((struct ifaddr *)ifa, 0);
1499 }
1500 } else {
1501 ifa->ia6_flags |= IN6_IFF_DETACHED;
1502 }
1503 }
1504 }
1505 else {
1506 for (ifa = in6_ifaddr; ifa; ifa = ifa->ia_next) {
1507 if ((ifa->ia6_flags & IN6_IFF_AUTOCONF) == 0)
1508 continue;
1509
1510 if (ifa->ia6_flags & IN6_IFF_DETACHED) {
1511 ifa->ia6_flags &= ~IN6_IFF_DETACHED;
1512 ifa->ia6_flags |= IN6_IFF_TENTATIVE;
1513 /* Do we need a delay in this case? */
1514 nd6_dad_start((struct ifaddr *)ifa, 0);
1515 }
1516 }
1517 }
1518 }
1519
1520 int
1521 nd6_prefix_onlink(struct nd_prefix *pr)
1522 {
1523 struct ifaddr *ifa;
1524 struct ifnet *ifp = pr->ndpr_ifp;
1525 struct sockaddr_in6 mask6;
1526 struct nd_prefix *opr;
1527 u_long rtflags;
1528 int error = 0;
1529 struct rtentry *rt = NULL;
1530 char ip6buf[INET6_ADDRSTRLEN];
1531
1532 /* sanity check */
1533 if ((pr->ndpr_stateflags & NDPRF_ONLINK) != 0) {
1534 nd6log((LOG_ERR,
1535 "nd6_prefix_onlink: %s/%d is already on-link\n",
1536 ip6_sprintf(ip6buf, &pr->ndpr_prefix.sin6_addr),
1537 pr->ndpr_plen));
1538 return (EEXIST);
1539 }
1540
1541 /*
1542 * Add the interface route associated with the prefix. Before
1543 * installing the route, check if there's the same prefix on another
1544 * interface, and the prefix has already installed the interface route.
1545 * Although such a configuration is expected to be rare, we explicitly
1546 * allow it.
1547 */
1548 for (opr = nd_prefix.lh_first; opr; opr = opr->ndpr_next) {
1549 if (opr == pr)
1550 continue;
1551
1552 if ((opr->ndpr_stateflags & NDPRF_ONLINK) == 0)
1553 continue;
1554
1555 if (opr->ndpr_plen == pr->ndpr_plen &&
1556 in6_are_prefix_equal(&pr->ndpr_prefix.sin6_addr,
1557 &opr->ndpr_prefix.sin6_addr, pr->ndpr_plen))
1558 return (0);
1559 }
1560
1561 /*
1562 * We prefer link-local addresses as the associated interface address.
1563 */
1564 /* search for a link-local addr */
1565 ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp,
1566 IN6_IFF_NOTREADY | IN6_IFF_ANYCAST);
1567 if (ifa == NULL) {
1568 /* XXX: freebsd does not have ifa_ifwithaf */
1569 TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) {
1570 if (ifa->ifa_addr->sa_family == AF_INET6)
1571 break;
1572 }
1573 /* should we care about ia6_flags? */
1574 }
1575 if (ifa == NULL) {
1576 /*
1577 * This can still happen, when, for example, we receive an RA
1578 * containing a prefix with the L bit set and the A bit clear,
1579 * after removing all IPv6 addresses on the receiving
1580 * interface. This should, of course, be rare though.
1581 */
1582 nd6log((LOG_NOTICE,
1583 "nd6_prefix_onlink: failed to find any ifaddr"
1584 " to add route for a prefix(%s/%d) on %s\n",
1585 ip6_sprintf(ip6buf, &pr->ndpr_prefix.sin6_addr),
1586 pr->ndpr_plen, if_name(ifp)));
1587 return (0);
1588 }
1589
1590 /*
1591 * in6_ifinit() sets nd6_rtrequest to ifa_rtrequest for all ifaddrs.
1592 * ifa->ifa_rtrequest = nd6_rtrequest;
1593 */
1594 bzero(&mask6, sizeof(mask6));
1595 mask6.sin6_len = sizeof(mask6);
1596 mask6.sin6_addr = pr->ndpr_mask;
1597 rtflags = ifa->ifa_flags | RTF_CLONING | RTF_UP;
1598 if (nd6_need_cache(ifp)) {
1599 /* explicitly set in case ifa_flags does not set the flag. */
1600 rtflags |= RTF_CLONING;
1601 } else {
1602 /*
1603 * explicitly clear the cloning bit in case ifa_flags sets it.
1604 */
1605 rtflags &= ~RTF_CLONING;
1606 }
1607 error = rtrequest(RTM_ADD, (struct sockaddr *)&pr->ndpr_prefix,
1608 ifa->ifa_addr, (struct sockaddr *)&mask6, rtflags, &rt);
1609 if (error == 0) {
1610 if (rt != NULL) /* this should be non NULL, though */
1611 nd6_rtmsg(RTM_ADD, rt);
1612 pr->ndpr_stateflags |= NDPRF_ONLINK;
1613 } else {
1614 char ip6bufg[INET6_ADDRSTRLEN], ip6bufm[INET6_ADDRSTRLEN];
1615 nd6log((LOG_ERR, "nd6_prefix_onlink: failed to add route for a"
1616 " prefix (%s/%d) on %s, gw=%s, mask=%s, flags=%lx "
1617 "errno = %d\n",
1618 ip6_sprintf(ip6buf, &pr->ndpr_prefix.sin6_addr),
1619 pr->ndpr_plen, if_name(ifp),
1620 ip6_sprintf(ip6bufg, &((struct sockaddr_in6 *)ifa->ifa_addr)->sin6_addr),
1621 ip6_sprintf(ip6bufm, &mask6.sin6_addr), rtflags, error));
1622 }
1623
1624 if (rt != NULL) {
1625 RT_LOCK(rt);
1626 RT_REMREF(rt);
1627 RT_UNLOCK(rt);
1628 }
1629
1630 return (error);
1631 }
1632
1633 int
1634 nd6_prefix_offlink(struct nd_prefix *pr)
1635 {
1636 int error = 0;
1637 struct ifnet *ifp = pr->ndpr_ifp;
1638 struct nd_prefix *opr;
1639 struct sockaddr_in6 sa6, mask6;
1640 struct rtentry *rt = NULL;
1641 char ip6buf[INET6_ADDRSTRLEN];
1642
1643 /* sanity check */
1644 if ((pr->ndpr_stateflags & NDPRF_ONLINK) == 0) {
1645 nd6log((LOG_ERR,
1646 "nd6_prefix_offlink: %s/%d is already off-link\n",
1647 ip6_sprintf(ip6buf, &pr->ndpr_prefix.sin6_addr),
1648 pr->ndpr_plen));
1649 return (EEXIST);
1650 }
1651
1652 bzero(&sa6, sizeof(sa6));
1653 sa6.sin6_family = AF_INET6;
1654 sa6.sin6_len = sizeof(sa6);
1655 bcopy(&pr->ndpr_prefix.sin6_addr, &sa6.sin6_addr,
1656 sizeof(struct in6_addr));
1657 bzero(&mask6, sizeof(mask6));
1658 mask6.sin6_family = AF_INET6;
1659 mask6.sin6_len = sizeof(sa6);
1660 bcopy(&pr->ndpr_mask, &mask6.sin6_addr, sizeof(struct in6_addr));
1661 error = rtrequest(RTM_DELETE, (struct sockaddr *)&sa6, NULL,
1662 (struct sockaddr *)&mask6, 0, &rt);
1663 if (error == 0) {
1664 pr->ndpr_stateflags &= ~NDPRF_ONLINK;
1665
1666 /* report the route deletion to the routing socket. */
1667 if (rt != NULL)
1668 nd6_rtmsg(RTM_DELETE, rt);
1669
1670 /*
1671 * There might be the same prefix on another interface,
1672 * the prefix which could not be on-link just because we have
1673 * the interface route (see comments in nd6_prefix_onlink).
1674 * If there's one, try to make the prefix on-link on the
1675 * interface.
1676 */
1677 for (opr = nd_prefix.lh_first; opr; opr = opr->ndpr_next) {
1678 if (opr == pr)
1679 continue;
1680
1681 if ((opr->ndpr_stateflags & NDPRF_ONLINK) != 0)
1682 continue;
1683
1684 /*
1685 * KAME specific: detached prefixes should not be
1686 * on-link.
1687 */
1688 if ((opr->ndpr_stateflags & NDPRF_DETACHED) != 0)
1689 continue;
1690
1691 if (opr->ndpr_plen == pr->ndpr_plen &&
1692 in6_are_prefix_equal(&pr->ndpr_prefix.sin6_addr,
1693 &opr->ndpr_prefix.sin6_addr, pr->ndpr_plen)) {
1694 int e;
1695
1696 if ((e = nd6_prefix_onlink(opr)) != 0) {
1697 nd6log((LOG_ERR,
1698 "nd6_prefix_offlink: failed to "
1699 "recover a prefix %s/%d from %s "
1700 "to %s (errno = %d)\n",
1701 ip6_sprintf(ip6buf,
1702 &opr->ndpr_prefix.sin6_addr),
1703 opr->ndpr_plen, if_name(ifp),
1704 if_name(opr->ndpr_ifp), e));
1705 }
1706 }
1707 }
1708 } else {
1709 /* XXX: can we still set the NDPRF_ONLINK flag? */
1710 nd6log((LOG_ERR,
1711 "nd6_prefix_offlink: failed to delete route: "
1712 "%s/%d on %s (errno = %d)\n",
1713 ip6_sprintf(ip6buf, &sa6.sin6_addr), pr->ndpr_plen,
1714 if_name(ifp), error));
1715 }
1716
1717 if (rt != NULL) {
1718 RTFREE(rt);
1719 }
1720
1721 return (error);
1722 }
1723
1724 static struct in6_ifaddr *
1725 in6_ifadd(struct nd_prefixctl *pr, int mcast)
1726 {
1727 struct ifnet *ifp = pr->ndpr_ifp;
1728 struct ifaddr *ifa;
1729 struct in6_aliasreq ifra;
1730 struct in6_ifaddr *ia, *ib;
1731 int error, plen0;
1732 struct in6_addr mask;
1733 int prefixlen = pr->ndpr_plen;
1734 int updateflags;
1735 char ip6buf[INET6_ADDRSTRLEN];
1736
1737 in6_prefixlen2mask(&mask, prefixlen);
1738
1739 /*
1740 * find a link-local address (will be interface ID).
1741 * Is it really mandatory? Theoretically, a global or a site-local
1742 * address can be configured without a link-local address, if we
1743 * have a unique interface identifier...
1744 *
1745 * it is not mandatory to have a link-local address, we can generate
1746 * interface identifier on the fly. we do this because:
1747 * (1) it should be the easiest way to find interface identifier.
1748 * (2) RFC2462 5.4 suggesting the use of the same interface identifier
1749 * for multiple addresses on a single interface, and possible shortcut
1750 * of DAD. we omitted DAD for this reason in the past.
1751 * (3) a user can prevent autoconfiguration of global address
1752 * by removing link-local address by hand (this is partly because we
1753 * don't have other way to control the use of IPv6 on an interface.
1754 * this has been our design choice - cf. NRL's "ifconfig auto").
1755 * (4) it is easier to manage when an interface has addresses
1756 * with the same interface identifier, than to have multiple addresses
1757 * with different interface identifiers.
1758 */
1759 ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp, 0); /* 0 is OK? */
1760 if (ifa)
1761 ib = (struct in6_ifaddr *)ifa;
1762 else
1763 return NULL;
1764
1765 /* prefixlen + ifidlen must be equal to 128 */
1766 plen0 = in6_mask2len(&ib->ia_prefixmask.sin6_addr, NULL);
1767 if (prefixlen != plen0) {
1768 nd6log((LOG_INFO, "in6_ifadd: wrong prefixlen for %s "
1769 "(prefix=%d ifid=%d)\n",
1770 if_name(ifp), prefixlen, 128 - plen0));
1771 return NULL;
1772 }
1773
1774 /* make ifaddr */
1775
1776 bzero(&ifra, sizeof(ifra));
1777 /*
1778 * in6_update_ifa() does not use ifra_name, but we accurately set it
1779 * for safety.
1780 */
1781 strncpy(ifra.ifra_name, if_name(ifp), sizeof(ifra.ifra_name));
1782 ifra.ifra_addr.sin6_family = AF_INET6;
1783 ifra.ifra_addr.sin6_len = sizeof(struct sockaddr_in6);
1784 /* prefix */
1785 ifra.ifra_addr.sin6_addr = pr->ndpr_prefix.sin6_addr;
1786 ifra.ifra_addr.sin6_addr.s6_addr32[0] &= mask.s6_addr32[0];
1787 ifra.ifra_addr.sin6_addr.s6_addr32[1] &= mask.s6_addr32[1];
1788 ifra.ifra_addr.sin6_addr.s6_addr32[2] &= mask.s6_addr32[2];
1789 ifra.ifra_addr.sin6_addr.s6_addr32[3] &= mask.s6_addr32[3];
1790
1791 /* interface ID */
1792 ifra.ifra_addr.sin6_addr.s6_addr32[0] |=
1793 (ib->ia_addr.sin6_addr.s6_addr32[0] & ~mask.s6_addr32[0]);
1794 ifra.ifra_addr.sin6_addr.s6_addr32[1] |=
1795 (ib->ia_addr.sin6_addr.s6_addr32[1] & ~mask.s6_addr32[1]);
1796 ifra.ifra_addr.sin6_addr.s6_addr32[2] |=
1797 (ib->ia_addr.sin6_addr.s6_addr32[2] & ~mask.s6_addr32[2]);
1798 ifra.ifra_addr.sin6_addr.s6_addr32[3] |=
1799 (ib->ia_addr.sin6_addr.s6_addr32[3] & ~mask.s6_addr32[3]);
1800
1801 /* new prefix mask. */
1802 ifra.ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6);
1803 ifra.ifra_prefixmask.sin6_family = AF_INET6;
1804 bcopy(&mask, &ifra.ifra_prefixmask.sin6_addr,
1805 sizeof(ifra.ifra_prefixmask.sin6_addr));
1806
1807 /* lifetimes. */
1808 ifra.ifra_lifetime.ia6t_vltime = pr->ndpr_vltime;
1809 ifra.ifra_lifetime.ia6t_pltime = pr->ndpr_pltime;
1810
1811 /* XXX: scope zone ID? */
1812
1813 ifra.ifra_flags |= IN6_IFF_AUTOCONF; /* obey autoconf */
1814
1815 /*
1816 * Make sure that we do not have this address already. This should
1817 * usually not happen, but we can still see this case, e.g., if we
1818 * have manually configured the exact address to be configured.
1819 */
1820 if (in6ifa_ifpwithaddr(ifp, &ifra.ifra_addr.sin6_addr) != NULL) {
1821 /* this should be rare enough to make an explicit log */
1822 log(LOG_INFO, "in6_ifadd: %s is already configured\n",
1823 ip6_sprintf(ip6buf, &ifra.ifra_addr.sin6_addr));
1824 return (NULL);
1825 }
1826
1827 /*
1828 * Allocate ifaddr structure, link into chain, etc.
1829 * If we are going to create a new address upon receiving a multicasted
1830 * RA, we need to impose a random delay before starting DAD.
1831 * [draft-ietf-ipv6-rfc2462bis-02.txt, Section 5.4.2]
1832 */
1833 updateflags = 0;
1834 if (mcast)
1835 updateflags |= IN6_IFAUPDATE_DADDELAY;
1836 if ((error = in6_update_ifa(ifp, &ifra, NULL, updateflags)) != 0) {
1837 nd6log((LOG_ERR,
1838 "in6_ifadd: failed to make ifaddr %s on %s (errno=%d)\n",
1839 ip6_sprintf(ip6buf, &ifra.ifra_addr.sin6_addr),
1840 if_name(ifp), error));
1841 return (NULL); /* ifaddr must not have been allocated. */
1842 }
1843
1844 ia = in6ifa_ifpwithaddr(ifp, &ifra.ifra_addr.sin6_addr);
1845
1846 return (ia); /* this is always non-NULL */
1847 }
1848
1849 /*
1850 * ia0 - corresponding public address
1851 */
1852 int
1853 in6_tmpifadd(const struct in6_ifaddr *ia0, int forcegen, int delay)
1854 {
1855 struct ifnet *ifp = ia0->ia_ifa.ifa_ifp;
1856 struct in6_ifaddr *newia, *ia;
1857 struct in6_aliasreq ifra;
1858 int i, error;
1859 int trylimit = 3; /* XXX: adhoc value */
1860 int updateflags;
1861 u_int32_t randid[2];
1862 time_t vltime0, pltime0;
1863
1864 bzero(&ifra, sizeof(ifra));
1865 strncpy(ifra.ifra_name, if_name(ifp), sizeof(ifra.ifra_name));
1866 ifra.ifra_addr = ia0->ia_addr;
1867 /* copy prefix mask */
1868 ifra.ifra_prefixmask = ia0->ia_prefixmask;
1869 /* clear the old IFID */
1870 for (i = 0; i < 4; i++) {
1871 ifra.ifra_addr.sin6_addr.s6_addr32[i] &=
1872 ifra.ifra_prefixmask.sin6_addr.s6_addr32[i];
1873 }
1874
1875 again:
1876 if (in6_get_tmpifid(ifp, (u_int8_t *)randid,
1877 (const u_int8_t *)&ia0->ia_addr.sin6_addr.s6_addr[8], forcegen)) {
1878 nd6log((LOG_NOTICE, "in6_tmpifadd: failed to find a good "
1879 "random IFID\n"));
1880 return (EINVAL);
1881 }
1882 ifra.ifra_addr.sin6_addr.s6_addr32[2] |=
1883 (randid[0] & ~(ifra.ifra_prefixmask.sin6_addr.s6_addr32[2]));
1884 ifra.ifra_addr.sin6_addr.s6_addr32[3] |=
1885 (randid[1] & ~(ifra.ifra_prefixmask.sin6_addr.s6_addr32[3]));
1886
1887 /*
1888 * in6_get_tmpifid() quite likely provided a unique interface ID.
1889 * However, we may still have a chance to see collision, because
1890 * there may be a time lag between generation of the ID and generation
1891 * of the address. So, we'll do one more sanity check.
1892 */
1893 for (ia = in6_ifaddr; ia; ia = ia->ia_next) {
1894 if (IN6_ARE_ADDR_EQUAL(&ia->ia_addr.sin6_addr,
1895 &ifra.ifra_addr.sin6_addr)) {
1896 if (trylimit-- == 0) {
1897 /*
1898 * Give up. Something strange should have
1899 * happened.
1900 */
1901 nd6log((LOG_NOTICE, "in6_tmpifadd: failed to "
1902 "find a unique random IFID\n"));
1903 return (EEXIST);
1904 }
1905 forcegen = 1;
1906 goto again;
1907 }
1908 }
1909
1910 /*
1911 * The Valid Lifetime is the lower of the Valid Lifetime of the
1912 * public address or TEMP_VALID_LIFETIME.
1913 * The Preferred Lifetime is the lower of the Preferred Lifetime
1914 * of the public address or TEMP_PREFERRED_LIFETIME -
1915 * DESYNC_FACTOR.
1916 */
1917 if (ia0->ia6_lifetime.ia6t_vltime != ND6_INFINITE_LIFETIME) {
1918 vltime0 = IFA6_IS_INVALID(ia0) ? 0 :
1919 (ia0->ia6_lifetime.ia6t_vltime -
1920 (time_second - ia0->ia6_updatetime));
1921 if (vltime0 > ip6_temp_valid_lifetime)
1922 vltime0 = ip6_temp_valid_lifetime;
1923 } else
1924 vltime0 = ip6_temp_valid_lifetime;
1925 if (ia0->ia6_lifetime.ia6t_pltime != ND6_INFINITE_LIFETIME) {
1926 pltime0 = IFA6_IS_DEPRECATED(ia0) ? 0 :
1927 (ia0->ia6_lifetime.ia6t_pltime -
1928 (time_second - ia0->ia6_updatetime));
1929 if (pltime0 > ip6_temp_preferred_lifetime - ip6_desync_factor){
1930 pltime0 = ip6_temp_preferred_lifetime -
1931 ip6_desync_factor;
1932 }
1933 } else
1934 pltime0 = ip6_temp_preferred_lifetime - ip6_desync_factor;
1935 ifra.ifra_lifetime.ia6t_vltime = vltime0;
1936 ifra.ifra_lifetime.ia6t_pltime = pltime0;
1937
1938 /*
1939 * A temporary address is created only if this calculated Preferred
1940 * Lifetime is greater than REGEN_ADVANCE time units.
1941 */
1942 if (ifra.ifra_lifetime.ia6t_pltime <= ip6_temp_regen_advance)
1943 return (0);
1944
1945 /* XXX: scope zone ID? */
1946
1947 ifra.ifra_flags |= (IN6_IFF_AUTOCONF|IN6_IFF_TEMPORARY);
1948
1949 /* allocate ifaddr structure, link into chain, etc. */
1950 updateflags = 0;
1951 if (delay)
1952 updateflags |= IN6_IFAUPDATE_DADDELAY;
1953 if ((error = in6_update_ifa(ifp, &ifra, NULL, updateflags)) != 0)
1954 return (error);
1955
1956 newia = in6ifa_ifpwithaddr(ifp, &ifra.ifra_addr.sin6_addr);
1957 if (newia == NULL) { /* XXX: can it happen? */
1958 nd6log((LOG_ERR,
1959 "in6_tmpifadd: ifa update succeeded, but we got "
1960 "no ifaddr\n"));
1961 return (EINVAL); /* XXX */
1962 }
1963 newia->ia6_ndpr = ia0->ia6_ndpr;
1964 newia->ia6_ndpr->ndpr_refcnt++;
1965
1966 /*
1967 * A newly added address might affect the status of other addresses.
1968 * XXX: when the temporary address is generated with a new public
1969 * address, the onlink check is redundant. However, it would be safe
1970 * to do the check explicitly everywhere a new address is generated,
1971 * and, in fact, we surely need the check when we create a new
1972 * temporary address due to deprecation of an old temporary address.
1973 */
1974 pfxlist_onlink_check();
1975
1976 return (0);
1977 }
1978
1979 static int
1980 in6_init_prefix_ltimes(struct nd_prefix *ndpr)
1981 {
1982 if (ndpr->ndpr_pltime == ND6_INFINITE_LIFETIME)
1983 ndpr->ndpr_preferred = 0;
1984 else
1985 ndpr->ndpr_preferred = time_second + ndpr->ndpr_pltime;
1986 if (ndpr->ndpr_vltime == ND6_INFINITE_LIFETIME)
1987 ndpr->ndpr_expire = 0;
1988 else
1989 ndpr->ndpr_expire = time_second + ndpr->ndpr_vltime;
1990
1991 return 0;
1992 }
1993
1994 static void
1995 in6_init_address_ltimes(struct nd_prefix *new, struct in6_addrlifetime *lt6)
1996 {
1997 /* init ia6t_expire */
1998 if (lt6->ia6t_vltime == ND6_INFINITE_LIFETIME)
1999 lt6->ia6t_expire = 0;
2000 else {
2001 lt6->ia6t_expire = time_second;
2002 lt6->ia6t_expire += lt6->ia6t_vltime;
2003 }
2004
2005 /* init ia6t_preferred */
2006 if (lt6->ia6t_pltime == ND6_INFINITE_LIFETIME)
2007 lt6->ia6t_preferred = 0;
2008 else {
2009 lt6->ia6t_preferred = time_second;
2010 lt6->ia6t_preferred += lt6->ia6t_pltime;
2011 }
2012 }
2013
2014 /*
2015 * Delete all the routing table entries that use the specified gateway.
2016 * XXX: this function causes search through all entries of routing table, so
2017 * it shouldn't be called when acting as a router.
2018 */
2019 void
2020 rt6_flush(struct in6_addr *gateway, struct ifnet *ifp)
2021 {
2022
2023 struct radix_node_head *rnh = rt_tables[0][AF_INET6];
2024 int s = splnet();
2025
2026 /* We'll care only link-local addresses */
2027 if (!IN6_IS_ADDR_LINKLOCAL(gateway)) {
2028 splx(s);
2029 return;
2030 }
2031
2032 RADIX_NODE_HEAD_LOCK(rnh);
2033 rnh->rnh_walktree(rnh, rt6_deleteroute, (void *)gateway);
2034 RADIX_NODE_HEAD_UNLOCK(rnh);
2035 splx(s);
2036 }
2037
2038 static int
2039 rt6_deleteroute(struct radix_node *rn, void *arg)
2040 {
2041 #define SIN6(s) ((struct sockaddr_in6 *)s)
2042 struct rtentry *rt = (struct rtentry *)rn;
2043 struct in6_addr *gate = (struct in6_addr *)arg;
2044
2045 if (rt->rt_gateway == NULL || rt->rt_gateway->sa_family != AF_INET6)
2046 return (0);
2047
2048 if (!IN6_ARE_ADDR_EQUAL(gate, &SIN6(rt->rt_gateway)->sin6_addr)) {
2049 return (0);
2050 }
2051
2052 /*
2053 * Do not delete a static route.
2054 * XXX: this seems to be a bit ad-hoc. Should we consider the
2055 * 'cloned' bit instead?
2056 */
2057 if ((rt->rt_flags & RTF_STATIC) != 0)
2058 return (0);
2059
2060 /*
2061 * We delete only host route. This means, in particular, we don't
2062 * delete default route.
2063 */
2064 if ((rt->rt_flags & RTF_HOST) == 0)
2065 return (0);
2066
2067 return (rtrequest(RTM_DELETE, rt_key(rt), rt->rt_gateway,
2068 rt_mask(rt), rt->rt_flags, 0));
2069 #undef SIN6
2070 }
2071
2072 int
2073 nd6_setdefaultiface(int ifindex)
2074 {
2075 int error = 0;
2076
2077 if (ifindex < 0 || if_index < ifindex)
2078 return (EINVAL);
2079 if (ifindex != 0 && !ifnet_byindex(ifindex))
2080 return (EINVAL);
2081
2082 if (nd6_defifindex != ifindex) {
2083 nd6_defifindex = ifindex;
2084 if (nd6_defifindex > 0)
2085 nd6_defifp = ifnet_byindex(nd6_defifindex);
2086 else
2087 nd6_defifp = NULL;
2088
2089 /*
2090 * Our current implementation assumes one-to-one maping between
2091 * interfaces and links, so it would be natural to use the
2092 * default interface as the default link.
2093 */
2094 scope6_setdefault(nd6_defifp);
2095 }
2096
2097 return (error);
2098 }
Cache object: 07a3e296db278fa9341a63897fa833b1
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