1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the project nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 *
31 * $KAME: nd6_rtr.c,v 1.111 2001/04/27 01:37:15 jinmei Exp $
32 */
33
34 #include "opt_inet.h"
35 #include "opt_inet6.h"
36
37 #include <sys/param.h>
38 #include <sys/systm.h>
39 #include <sys/malloc.h>
40 #include <sys/mbuf.h>
41 #include <sys/refcount.h>
42 #include <sys/socket.h>
43 #include <sys/sockio.h>
44 #include <sys/time.h>
45 #include <sys/kernel.h>
46 #include <sys/lock.h>
47 #include <sys/errno.h>
48 #include <sys/rmlock.h>
49 #include <sys/rwlock.h>
50 #include <sys/sysctl.h>
51 #include <sys/syslog.h>
52 #include <sys/queue.h>
53 #include <sys/random.h>
54
55 #include <net/if.h>
56 #include <net/if_var.h>
57 #include <net/if_private.h>
58 #include <net/if_types.h>
59 #include <net/if_dl.h>
60 #include <net/route.h>
61 #include <net/route/nhop.h>
62 #include <net/route/route_ctl.h>
63 #include <net/radix.h>
64 #include <net/vnet.h>
65
66 #include <netinet/in.h>
67 #include <net/if_llatbl.h>
68 #include <netinet6/in6_var.h>
69 #include <netinet6/in6_ifattach.h>
70 #include <netinet/ip6.h>
71 #include <netinet6/ip6_var.h>
72 #include <netinet6/nd6.h>
73 #include <netinet/icmp6.h>
74 #include <netinet6/scope6_var.h>
75
76 #include <machine/atomic.h>
77
78 MALLOC_DEFINE(M_IP6NDP, "ip6ndp", "IPv6 Neighbor Discovery");
79
80 static struct nd_defrouter *defrtrlist_update(struct nd_defrouter *);
81 static int prelist_update(struct nd_prefixctl *, struct nd_defrouter *,
82 bool, int);
83 static int nd6_prefix_onlink(struct nd_prefix *);
84 static int in6_get_tmp_ifid(struct in6_aliasreq *);
85
86 TAILQ_HEAD(nd6_drhead, nd_defrouter);
87 VNET_DEFINE_STATIC(struct nd6_drhead, nd6_defrouter);
88 #define V_nd6_defrouter VNET(nd6_defrouter)
89
90 VNET_DECLARE(int, nd6_recalc_reachtm_interval);
91 #define V_nd6_recalc_reachtm_interval VNET(nd6_recalc_reachtm_interval)
92
93 VNET_DEFINE_STATIC(struct ifnet *, nd6_defifp);
94 VNET_DEFINE(int, nd6_defifindex);
95 #define V_nd6_defifp VNET(nd6_defifp)
96
97 VNET_DEFINE(int, ip6_use_tempaddr) = 0;
98 VNET_DEFINE(bool, ip6_use_stableaddr) = 1;
99
100 VNET_DEFINE(int, ip6_desync_factor);
101 VNET_DEFINE(uint32_t, ip6_temp_max_desync_factor) = TEMP_MAX_DESYNC_FACTOR_BASE;
102 VNET_DEFINE(u_int32_t, ip6_temp_preferred_lifetime) = DEF_TEMP_PREFERRED_LIFETIME;
103 VNET_DEFINE(u_int32_t, ip6_temp_valid_lifetime) = DEF_TEMP_VALID_LIFETIME;
104
105 VNET_DEFINE(int, ip6_temp_regen_advance) = TEMPADDR_REGEN_ADVANCE;
106
107 #ifdef EXPERIMENTAL
108 VNET_DEFINE_STATIC(int, nd6_ignore_ipv6_only_ra) = 1;
109 #define V_nd6_ignore_ipv6_only_ra VNET(nd6_ignore_ipv6_only_ra)
110 SYSCTL_INT(_net_inet6_icmp6, OID_AUTO,
111 nd6_ignore_ipv6_only_ra, CTLFLAG_VNET | CTLFLAG_RW,
112 &VNET_NAME(nd6_ignore_ipv6_only_ra), 0,
113 "Ignore the 'IPv6-Only flag' in RA messages in compliance with "
114 "draft-ietf-6man-ipv6only-flag");
115 #endif
116
117 /* RTPREF_MEDIUM has to be 0! */
118 #define RTPREF_HIGH 1
119 #define RTPREF_MEDIUM 0
120 #define RTPREF_LOW (-1)
121 #define RTPREF_RESERVED (-2)
122 #define RTPREF_INVALID (-3) /* internal */
123
124 static void
defrouter_ref(struct nd_defrouter * dr)125 defrouter_ref(struct nd_defrouter *dr)
126 {
127
128 refcount_acquire(&dr->refcnt);
129 }
130
131 void
defrouter_rele(struct nd_defrouter * dr)132 defrouter_rele(struct nd_defrouter *dr)
133 {
134
135 if (refcount_release(&dr->refcnt))
136 free(dr, M_IP6NDP);
137 }
138
139 /*
140 * Remove a router from the global list and optionally stash it in a
141 * caller-supplied queue.
142 */
143 static void
defrouter_unlink(struct nd_defrouter * dr,struct nd6_drhead * drq)144 defrouter_unlink(struct nd_defrouter *dr, struct nd6_drhead *drq)
145 {
146
147 ND6_WLOCK_ASSERT();
148
149 TAILQ_REMOVE(&V_nd6_defrouter, dr, dr_entry);
150 V_nd6_list_genid++;
151 if (drq != NULL)
152 TAILQ_INSERT_TAIL(drq, dr, dr_entry);
153 }
154
155 /*
156 * Receive Router Solicitation Message - just for routers.
157 * Router solicitation/advertisement is mostly managed by userland program
158 * (rtadvd) so here we have no function like nd6_ra_output().
159 *
160 * Based on RFC 2461
161 */
162 void
nd6_rs_input(struct mbuf * m,int off,int icmp6len)163 nd6_rs_input(struct mbuf *m, int off, int icmp6len)
164 {
165 struct ifnet *ifp;
166 struct ip6_hdr *ip6;
167 struct nd_router_solicit *nd_rs;
168 struct in6_addr saddr6;
169 union nd_opts ndopts;
170 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
171 char *lladdr;
172 int lladdrlen;
173
174 ifp = m->m_pkthdr.rcvif;
175
176 /*
177 * Accept RS only when V_ip6_forwarding=1 and the interface has
178 * no ND6_IFF_ACCEPT_RTADV.
179 */
180 if (!V_ip6_forwarding || ifp->if_inet6->nd_flags & ND6_IFF_ACCEPT_RTADV)
181 goto freeit;
182
183 /* RFC 6980: Nodes MUST silently ignore fragments */
184 if(m->m_flags & M_FRAGMENTED)
185 goto freeit;
186
187 /* Sanity checks */
188 ip6 = mtod(m, struct ip6_hdr *);
189 if (__predict_false(ip6->ip6_hlim != 255)) {
190 ICMP6STAT_INC(icp6s_invlhlim);
191 nd6log((LOG_ERR,
192 "%s: invalid hlim (%d) from %s to %s on %s\n", __func__,
193 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src),
194 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp)));
195 goto bad;
196 }
197
198 /*
199 * Don't update the neighbor cache, if src = ::.
200 * This indicates that the src has no IP address assigned yet.
201 */
202 saddr6 = ip6->ip6_src;
203 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6))
204 goto freeit;
205
206 if (m->m_len < off + icmp6len) {
207 m = m_pullup(m, off + icmp6len);
208 if (m == NULL) {
209 IP6STAT_INC(ip6s_exthdrtoolong);
210 return;
211 }
212 }
213 ip6 = mtod(m, struct ip6_hdr *);
214 nd_rs = (struct nd_router_solicit *)((caddr_t)ip6 + off);
215
216 icmp6len -= sizeof(*nd_rs);
217 nd6_option_init(nd_rs + 1, icmp6len, &ndopts);
218 if (nd6_options(&ndopts) < 0) {
219 nd6log((LOG_INFO,
220 "%s: invalid ND option, ignored\n", __func__));
221 /* nd6_options have incremented stats */
222 goto freeit;
223 }
224
225 lladdr = NULL;
226 lladdrlen = 0;
227 if (ndopts.nd_opts_src_lladdr) {
228 lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1);
229 lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3;
230 }
231
232 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
233 nd6log((LOG_INFO,
234 "%s: lladdrlen mismatch for %s (if %d, RS packet %d)\n",
235 __func__, ip6_sprintf(ip6bufs, &saddr6),
236 ifp->if_addrlen, lladdrlen - 2));
237 goto bad;
238 }
239
240 nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, ND_ROUTER_SOLICIT, 0);
241
242 freeit:
243 m_freem(m);
244 return;
245
246 bad:
247 ICMP6STAT_INC(icp6s_badrs);
248 m_freem(m);
249 }
250
251 #ifdef EXPERIMENTAL
252 /*
253 * An initial update routine for draft-ietf-6man-ipv6only-flag.
254 * We need to iterate over all default routers for the given
255 * interface to see whether they are all advertising the "S"
256 * (IPv6-Only) flag. If they do set, otherwise unset, the
257 * interface flag we later use to filter on.
258 *
259 * XXXGL: The use of IF_ADDR_WLOCK (previously it was IF_AFDATA_LOCK) in this
260 * function is quite strange.
261 */
262 static void
defrtr_ipv6_only_ifp(struct ifnet * ifp)263 defrtr_ipv6_only_ifp(struct ifnet *ifp)
264 {
265 struct nd_defrouter *dr;
266 bool ipv6_only, ipv6_only_old;
267 #ifdef INET
268 struct epoch_tracker et;
269 struct ifaddr *ifa;
270 bool has_ipv4_addr;
271 #endif
272
273 if (V_nd6_ignore_ipv6_only_ra != 0)
274 return;
275
276 ipv6_only = true;
277 ND6_RLOCK();
278 TAILQ_FOREACH(dr, &V_nd6_defrouter, dr_entry)
279 if (dr->ifp == ifp &&
280 (dr->raflags & ND_RA_FLAG_IPV6_ONLY) == 0)
281 ipv6_only = false;
282 ND6_RUNLOCK();
283
284 IF_ADDR_WLOCK(ifp);
285 ipv6_only_old = ifp->if_inet6->nd_flags & ND6_IFF_IPV6_ONLY;
286 IF_ADDR_WUNLOCK(ifp);
287
288 /* If nothing changed, we have an early exit. */
289 if (ipv6_only == ipv6_only_old)
290 return;
291
292 #ifdef INET
293 /*
294 * Should we want to set the IPV6-ONLY flag, check if the
295 * interface has a non-0/0 and non-link-local IPv4 address
296 * configured on it. If it has we will assume working
297 * IPv4 operations and will clear the interface flag.
298 */
299 has_ipv4_addr = false;
300 if (ipv6_only) {
301 NET_EPOCH_ENTER(et);
302 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
303 if (ifa->ifa_addr->sa_family != AF_INET)
304 continue;
305 if (in_canforward(
306 satosin(ifa->ifa_addr)->sin_addr)) {
307 has_ipv4_addr = true;
308 break;
309 }
310 }
311 NET_EPOCH_EXIT(et);
312 }
313 if (ipv6_only && has_ipv4_addr) {
314 log(LOG_NOTICE, "%s rcvd RA w/ IPv6-Only flag set but has IPv4 "
315 "configured, ignoring IPv6-Only flag.\n", ifp->if_xname);
316 ipv6_only = false;
317 }
318 #endif
319
320 IF_ADDR_WLOCK(ifp);
321 if (ipv6_only)
322 ifp->if_inet6->nd_flags |= ND6_IFF_IPV6_ONLY;
323 else
324 ifp->if_inet6->nd_flags &= ~ND6_IFF_IPV6_ONLY;
325 IF_ADDR_WUNLOCK(ifp);
326
327 #ifdef notyet
328 /* Send notification of flag change. */
329 #endif
330 }
331
332 static void
defrtr_ipv6_only_ipf_down(struct ifnet * ifp)333 defrtr_ipv6_only_ipf_down(struct ifnet *ifp)
334 {
335
336 IF_ADDR_WLOCK(ifp);
337 ifp->if_inet6->nd_flags &= ~ND6_IFF_IPV6_ONLY;
338 IF_ADDR_WUNLOCK(ifp);
339 }
340 #endif /* EXPERIMENTAL */
341
342 void
nd6_ifnet_link_event(void * arg __unused,struct ifnet * ifp,int linkstate)343 nd6_ifnet_link_event(void *arg __unused, struct ifnet *ifp, int linkstate)
344 {
345
346 /*
347 * XXX-BZ we might want to trigger re-evaluation of our default router
348 * availability. E.g., on link down the default router might be
349 * unreachable but a different interface might still have connectivity.
350 */
351
352 #ifdef EXPERIMENTAL
353 if (linkstate == LINK_STATE_DOWN)
354 defrtr_ipv6_only_ipf_down(ifp);
355 #endif
356 }
357
358 static void
nd6_ra_opt_pi(struct nd_opt_hdr * pt,struct ifnet * ifp,struct nd_router_advert * nd_ra,struct nd_defrouter * dr,bool auth,bool mcast)359 nd6_ra_opt_pi(struct nd_opt_hdr *pt, struct ifnet *ifp,
360 struct nd_router_advert *nd_ra, struct nd_defrouter *dr,
361 bool auth, bool mcast)
362 {
363 struct nd_opt_prefix_info *pi = NULL;
364 struct nd_prefixctl pr;
365 char ip6bufs[INET6_ADDRSTRLEN];
366
367 if (pt->nd_opt_type != ND_OPT_PREFIX_INFORMATION)
368 return;
369
370 pi = (struct nd_opt_prefix_info *)pt;
371 if (pi->nd_opt_pi_len != 4) {
372 nd6log((LOG_INFO,
373 "%s: invalid option len %d for prefix "
374 "information option, ignored\n", __func__,
375 pi->nd_opt_pi_len));
376 return;
377 }
378
379 if (pi->nd_opt_pi_prefix_len > 128) {
380 nd6log((LOG_INFO,
381 "%s: invalid prefix len %d for prefix "
382 "information option, ignored\n", __func__,
383 pi->nd_opt_pi_prefix_len));
384 return;
385 }
386
387 if (IN6_IS_ADDR_MULTICAST(&pi->nd_opt_pi_prefix)
388 || IN6_IS_ADDR_LINKLOCAL(&pi->nd_opt_pi_prefix)) {
389 nd6log((LOG_INFO,
390 "%s: invalid prefix %s, ignored\n",
391 __func__, ip6_sprintf(ip6bufs,
392 &pi->nd_opt_pi_prefix)));
393 return;
394 }
395
396 bzero(&pr, sizeof(pr));
397 pr.ndpr_prefix.sin6_family = AF_INET6;
398 pr.ndpr_prefix.sin6_len = sizeof(pr.ndpr_prefix);
399 pr.ndpr_prefix.sin6_addr = pi->nd_opt_pi_prefix;
400 pr.ndpr_ifp = ifp;
401
402 pr.ndpr_raf_onlink = (pi->nd_opt_pi_flags_reserved &
403 ND_OPT_PI_FLAG_ONLINK) ? 1 : 0;
404 pr.ndpr_raf_auto = (pi->nd_opt_pi_flags_reserved &
405 ND_OPT_PI_FLAG_AUTO) ? 1 : 0;
406 pr.ndpr_plen = pi->nd_opt_pi_prefix_len;
407 pr.ndpr_vltime = ntohl(pi->nd_opt_pi_valid_time);
408 pr.ndpr_pltime = ntohl(pi->nd_opt_pi_preferred_time);
409 (void)prelist_update(&pr, dr, auth, mcast);
410 }
411
412 static void
nd6_ra_opt_mtu(struct nd_opt_mtu * optmtu,struct ifnet * ifp,struct in6_addr saddr6)413 nd6_ra_opt_mtu(struct nd_opt_mtu *optmtu, struct ifnet *ifp,
414 struct in6_addr saddr6)
415 {
416 struct in6_ifextra *ndi;
417 char ip6bufs[INET6_ADDRSTRLEN];
418 uint32_t mtu, maxmtu;
419
420 ndi = ifp->if_inet6;
421
422 if (optmtu->nd_opt_mtu_len != 1)
423 return;
424 mtu = (uint32_t)ntohl(optmtu->nd_opt_mtu_mtu);
425 /* lower bound */
426 if (mtu < IPV6_MMTU) {
427 nd6log((LOG_INFO, "%s: bogus mtu option mtu=%u sent from %s, "
428 "ignoring\n", __func__, mtu, ip6_sprintf(ip6bufs, &saddr6)));
429 return;
430 }
431
432 /* upper bound */
433 maxmtu = (ndi->nd_maxmtu && ndi->nd_maxmtu < ifp->if_mtu)
434 ? ndi->nd_maxmtu : ifp->if_mtu;
435 if (mtu <= maxmtu) {
436 if (ndi->nd_linkmtu != mtu) {
437 ndi->nd_linkmtu = mtu;
438 rt_updatemtu(ifp);
439 }
440 } else {
441 nd6log((LOG_INFO, "%s: bogus mtu=%u sent from %s; "
442 "exceeds maxmtu %u, ignoring\n", __func__,
443 mtu, ip6_sprintf(ip6bufs, &saddr6), maxmtu));
444 }
445 }
446
447 static int
nd6_ra_opt_src_lladdr(struct nd_opt_hdr * opthdr,struct ifnet * ifp,struct in6_addr saddr6)448 nd6_ra_opt_src_lladdr(struct nd_opt_hdr *opthdr, struct ifnet *ifp,
449 struct in6_addr saddr6)
450 {
451 char ip6bufs[INET6_ADDRSTRLEN];
452 char *lladdr = NULL;
453 int lladdrlen = 0;
454
455 if (opthdr != NULL) {
456 lladdr = (char *)(opthdr + 1);
457 lladdrlen = opthdr->nd_opt_len << 3;
458 }
459
460 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
461 nd6log((LOG_INFO,
462 "%s: lladdrlen mismatch for %s (if %d, RA packet %d)\n",
463 __func__, ip6_sprintf(ip6bufs, &saddr6),
464 ifp->if_addrlen, lladdrlen - 2));
465 return (-1);
466 }
467
468 nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, ND_ROUTER_ADVERT, 0);
469
470 /*
471 * Installing a link-layer address might change the state of the
472 * router's neighbor cache, which might also affect our on-link
473 * detection of adveritsed prefixes.
474 */
475 pfxlist_onlink_check();
476 return (0);
477 }
478
479 /*
480 * Receive Router Advertisement Message.
481 *
482 * Based on RFC 2461
483 * TODO: on-link bit on prefix information
484 * TODO: ND_RA_FLAG_{OTHER,MANAGED} processing
485 */
486 void
nd6_ra_input(struct mbuf * m,int off,int icmp6len)487 nd6_ra_input(struct mbuf *m, int off, int icmp6len)
488 {
489 struct ifnet *ifp;
490 struct in6_ifextra *ndi;
491 struct ip6_hdr *ip6;
492 struct nd_router_advert *nd_ra;
493 struct nd_opt_hdr *pt;
494 struct in6_addr saddr6;
495 struct nd_defrouter dr0, *dr;
496 union nd_opts ndopts;
497 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
498 uint32_t advreachable;
499 bool mcast, auth;
500
501 /*
502 * We only accept RAs only when the per-interface flag
503 * ND6_IFF_ACCEPT_RTADV is on the receiving interface.
504 */
505 ifp = m->m_pkthdr.rcvif;
506 ndi = ifp->if_inet6;
507 if (!(ndi->nd_flags & ND6_IFF_ACCEPT_RTADV))
508 goto freeit;
509
510 /* RFC 6980: Nodes MUST silently ignore fragments */
511 if(m->m_flags & M_FRAGMENTED)
512 goto freeit;
513
514 ip6 = mtod(m, struct ip6_hdr *);
515 /* RFC 4861 section 6.1.2: hlim must be 255 */
516 if (__predict_false(ip6->ip6_hlim != 255)) {
517 ICMP6STAT_INC(icp6s_invlhlim);
518 nd6log((LOG_ERR,
519 "%s: invalid hlim (%d) from %s to %s on %s\n", __func__,
520 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src),
521 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp)));
522 goto bad;
523 }
524
525 saddr6 = ip6->ip6_src;
526 /* RFC 4861 section 6.1.2: source address must be link-local */
527 if (!IN6_IS_ADDR_LINKLOCAL(&saddr6)) {
528 nd6log((LOG_ERR,
529 "%s: src %s is not link-local\n", __func__,
530 ip6_sprintf(ip6bufs, &saddr6)));
531 goto bad;
532 }
533
534 if (m->m_len < off + icmp6len) {
535 m = m_pullup(m, off + icmp6len);
536 if (m == NULL) {
537 IP6STAT_INC(ip6s_exthdrtoolong);
538 return;
539 }
540 }
541 nd_ra = (struct nd_router_advert *)((caddr_t)ip6 + off);
542
543 icmp6len -= sizeof(*nd_ra);
544 nd6_option_init(nd_ra + 1, icmp6len, &ndopts);
545 if (nd6_options(&ndopts) < 0) {
546 nd6log((LOG_INFO,
547 "%s: invalid ND option, ignored\n", __func__));
548 /* nd6_options have incremented stats */
549 goto freeit;
550 }
551
552 dr = NULL;
553 mcast = false;
554 /* remember if this is a multicasted advertisement */
555 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst))
556 mcast = true;
557
558 bzero(&dr0, sizeof(dr0));
559 dr0.rtaddr = saddr6;
560 dr0.raflags = nd_ra->nd_ra_flags_reserved;
561 /*
562 * Effectively-disable routes from RA messages when
563 * ND6_IFF_NO_RADR enabled on the receiving interface or
564 * (ip6.forwarding == 1 && ip6.rfc6204w3 != 1).
565 */
566 if ((ndi->nd_flags & ND6_IFF_NO_RADR) ||
567 (V_ip6_forwarding && !V_ip6_rfc6204w3))
568 dr0.rtlifetime = 0;
569 else
570 dr0.rtlifetime = ntohs(nd_ra->nd_ra_router_lifetime);
571 dr0.expire = time_uptime + dr0.rtlifetime;
572 dr0.ifp = ifp;
573 /*
574 * RFC 4861 6.3.4: RA fields such as Cur Hop Limit,
575 * Reachable Time, and Retrans Timer may be unspecified.
576 * In such cases, the parameter should be ignored.
577 */
578 if (nd_ra->nd_ra_reachable) {
579 advreachable = ntohl(nd_ra->nd_ra_reachable);
580 if (advreachable <= MAX_REACHABLE_TIME &&
581 ndi->nd_basereachable != advreachable) {
582 ndi->nd_basereachable = advreachable;
583 ndi->nd_reachable =
584 ND_COMPUTE_RTIME(ndi->nd_basereachable);
585 ndi->nd_recalc_timer = V_nd6_recalc_reachtm_interval;
586 }
587 }
588 if (nd_ra->nd_ra_retransmit)
589 ndi->nd_retrans = ntohl(nd_ra->nd_ra_retransmit);
590 if (nd_ra->nd_ra_curhoplimit) {
591 if (ndi->nd_curhoplimit < nd_ra->nd_ra_curhoplimit)
592 ndi->nd_curhoplimit = nd_ra->nd_ra_curhoplimit;
593 else if (ndi->nd_curhoplimit != nd_ra->nd_ra_curhoplimit) {
594 log(LOG_ERR, "RA with a lower CurHopLimit sent from "
595 "%s on %s (current = %d, received = %d). "
596 "Ignored.\n", ip6_sprintf(ip6bufs, &ip6->ip6_src),
597 if_name(ifp), ndi->nd_curhoplimit,
598 nd_ra->nd_ra_curhoplimit);
599 }
600 }
601 dr = defrtrlist_update(&dr0);
602 #ifdef EXPERIMENTAL
603 defrtr_ipv6_only_ifp(ifp);
604 #endif
605 /* Prefix Information */
606 if (ndopts.nd_opts_pi != NULL) {
607 /*
608 * Authenticity for NA consists authentication for
609 * both IP header and IP datagrams, doesn't it ?
610 */
611 auth = ((m->m_flags & M_AUTHIPHDR) && (m->m_flags & M_AUTHIPDGM));
612 for (pt = (struct nd_opt_hdr *)ndopts.nd_opts_pi;
613 pt <= (struct nd_opt_hdr *)ndopts.nd_opts_pi_end;
614 pt = (struct nd_opt_hdr *)((caddr_t)pt +
615 (pt->nd_opt_len << 3))) {
616 nd6_ra_opt_pi(pt, ifp, nd_ra, dr, auth, mcast);
617 }
618 }
619 if (dr != NULL) {
620 defrouter_rele(dr);
621 dr = NULL;
622 }
623
624 /* MTU */
625 if (ndopts.nd_opts_mtu != NULL)
626 nd6_ra_opt_mtu(ndopts.nd_opts_mtu, ifp, saddr6);
627
628 /* Source link layer address */
629 if (nd6_ra_opt_src_lladdr(ndopts.nd_opts_src_lladdr, ifp, saddr6) != 0)
630 goto bad;
631
632 freeit:
633 m_freem(m);
634 return;
635
636 bad:
637 ICMP6STAT_INC(icp6s_badra);
638 m_freem(m);
639 }
640
641 /* PFXRTR */
642 static struct nd_pfxrouter *
pfxrtr_lookup(struct nd_prefix * pr,struct nd_defrouter * dr)643 pfxrtr_lookup(struct nd_prefix *pr, struct nd_defrouter *dr)
644 {
645 struct nd_pfxrouter *search;
646
647 ND6_LOCK_ASSERT();
648
649 LIST_FOREACH(search, &pr->ndpr_advrtrs, pfr_entry) {
650 if (search->router == dr)
651 break;
652 }
653 return (search);
654 }
655
656 static void
pfxrtr_add(struct nd_prefix * pr,struct nd_defrouter * dr)657 pfxrtr_add(struct nd_prefix *pr, struct nd_defrouter *dr)
658 {
659 struct nd_pfxrouter *new;
660 bool update;
661
662 ND6_UNLOCK_ASSERT();
663
664 ND6_RLOCK();
665 if (pfxrtr_lookup(pr, dr) != NULL) {
666 ND6_RUNLOCK();
667 return;
668 }
669 ND6_RUNLOCK();
670
671 new = malloc(sizeof(*new), M_IP6NDP, M_NOWAIT | M_ZERO);
672 if (new == NULL)
673 return;
674 defrouter_ref(dr);
675 new->router = dr;
676
677 ND6_WLOCK();
678 if (pfxrtr_lookup(pr, dr) == NULL) {
679 LIST_INSERT_HEAD(&pr->ndpr_advrtrs, new, pfr_entry);
680 update = true;
681 } else {
682 /* We lost a race to add the reference. */
683 defrouter_rele(dr);
684 free(new, M_IP6NDP);
685 update = false;
686 }
687 ND6_WUNLOCK();
688
689 if (update)
690 pfxlist_onlink_check();
691 }
692
693 static void
pfxrtr_del(struct nd_pfxrouter * pfr)694 pfxrtr_del(struct nd_pfxrouter *pfr)
695 {
696
697 ND6_WLOCK_ASSERT();
698
699 LIST_REMOVE(pfr, pfr_entry);
700 defrouter_rele(pfr->router);
701 free(pfr, M_IP6NDP);
702 }
703
704 /* Default router list processing sub routines. */
705 static void
defrouter_addreq(struct nd_defrouter * new)706 defrouter_addreq(struct nd_defrouter *new)
707 {
708 uint32_t fibnum = new->ifp->if_fib;
709 struct rib_cmd_info rc = {};
710 int error = 0;
711
712 NET_EPOCH_ASSERT();
713
714 struct sockaddr_in6 gw = {
715 .sin6_family = AF_INET6,
716 .sin6_len = sizeof(struct sockaddr_in6),
717 .sin6_addr = new->rtaddr,
718 };
719
720 error = rib_add_default_route(fibnum, AF_INET6, new->ifp,
721 (struct sockaddr *)&gw, &rc);
722
723 if (error == 0) {
724 struct nhop_object *nh = nhop_select_func(rc.rc_nh_new, 0);
725 rt_routemsg(RTM_ADD, rc.rc_rt, nh, fibnum);
726 new->installed = 1;
727 }
728 }
729
730 /*
731 * Remove the default route for a given router.
732 * This is just a subroutine function for defrouter_select_fib(), and
733 * should not be called from anywhere else.
734 */
735 static void
defrouter_delreq(struct nd_defrouter * dr)736 defrouter_delreq(struct nd_defrouter *dr)
737 {
738 uint32_t fibnum = dr->ifp->if_fib;
739 struct epoch_tracker et;
740 struct rib_cmd_info rc;
741 int error;
742
743 struct sockaddr_in6 dst = {
744 .sin6_family = AF_INET6,
745 .sin6_len = sizeof(struct sockaddr_in6),
746 };
747
748 struct sockaddr_in6 gw = {
749 .sin6_family = AF_INET6,
750 .sin6_len = sizeof(struct sockaddr_in6),
751 .sin6_addr = dr->rtaddr,
752 };
753
754 NET_EPOCH_ENTER(et);
755 error = rib_del_route_px(fibnum, (struct sockaddr *)&dst, 0,
756 rib_match_gw, (struct sockaddr *)&gw, 0, &rc);
757 if (error == 0) {
758 struct nhop_object *nh = nhop_select_func(rc.rc_nh_old, 0);
759 rt_routemsg(RTM_DELETE, rc.rc_rt, nh, fibnum);
760 }
761 NET_EPOCH_EXIT(et);
762
763 dr->installed = 0;
764 }
765
766 static void
defrouter_del(struct nd_defrouter * dr)767 defrouter_del(struct nd_defrouter *dr)
768 {
769 struct nd_defrouter *deldr = NULL;
770 struct nd_prefix *pr;
771 struct nd_pfxrouter *pfxrtr;
772
773 ND6_UNLOCK_ASSERT();
774
775 /*
776 * Flush all the routing table entries that use the router
777 * as a next hop.
778 */
779 if (dr->ifp->if_inet6->nd_flags & ND6_IFF_ACCEPT_RTADV)
780 rt6_flush(&dr->rtaddr, dr->ifp);
781
782 #ifdef EXPERIMENTAL
783 defrtr_ipv6_only_ifp(dr->ifp);
784 #endif
785
786 if (dr->installed) {
787 deldr = dr;
788 defrouter_delreq(dr);
789 }
790
791 /*
792 * Also delete all the pointers to the router in each prefix lists.
793 */
794 ND6_WLOCK();
795 LIST_FOREACH(pr, &V_nd_prefix, ndpr_entry) {
796 if ((pfxrtr = pfxrtr_lookup(pr, dr)) != NULL)
797 pfxrtr_del(pfxrtr);
798 }
799 ND6_WUNLOCK();
800
801 pfxlist_onlink_check();
802
803 /*
804 * If the router is the primary one, choose a new one.
805 * Note that defrouter_select_fib() will remove the current
806 * gateway from the routing table.
807 */
808 if (deldr)
809 defrouter_select_fib(deldr->ifp->if_fib);
810
811 /*
812 * Release the list reference.
813 */
814 defrouter_rele(dr);
815 }
816
817 struct nd_defrouter *
defrouter_lookup_locked(const struct in6_addr * addr,struct ifnet * ifp)818 defrouter_lookup_locked(const struct in6_addr *addr, struct ifnet *ifp)
819 {
820 struct nd_defrouter *dr;
821
822 ND6_LOCK_ASSERT();
823 TAILQ_FOREACH(dr, &V_nd6_defrouter, dr_entry)
824 if (dr->ifp == ifp && IN6_ARE_ADDR_EQUAL(addr, &dr->rtaddr)) {
825 defrouter_ref(dr);
826 return (dr);
827 }
828 return (NULL);
829 }
830
831 struct nd_defrouter *
defrouter_lookup(const struct in6_addr * addr,struct ifnet * ifp)832 defrouter_lookup(const struct in6_addr *addr, struct ifnet *ifp)
833 {
834 struct nd_defrouter *dr;
835
836 ND6_RLOCK();
837 dr = defrouter_lookup_locked(addr, ifp);
838 ND6_RUNLOCK();
839 return (dr);
840 }
841
842 /*
843 * Remove all default routes from default router list.
844 */
845 void
defrouter_reset(void)846 defrouter_reset(void)
847 {
848 struct nd_defrouter *dr, **dra;
849 int count, i;
850
851 count = i = 0;
852
853 /*
854 * We can't delete routes with the ND lock held, so make a copy of the
855 * current default router list and use that when deleting routes.
856 */
857 ND6_RLOCK();
858 TAILQ_FOREACH(dr, &V_nd6_defrouter, dr_entry)
859 count++;
860 ND6_RUNLOCK();
861
862 dra = malloc(count * sizeof(*dra), M_TEMP, M_WAITOK | M_ZERO);
863
864 ND6_RLOCK();
865 TAILQ_FOREACH(dr, &V_nd6_defrouter, dr_entry) {
866 if (i == count)
867 break;
868 defrouter_ref(dr);
869 dra[i++] = dr;
870 }
871 ND6_RUNLOCK();
872
873 for (i = 0; i < count && dra[i] != NULL; i++) {
874 defrouter_delreq(dra[i]);
875 defrouter_rele(dra[i]);
876 }
877 free(dra, M_TEMP);
878
879 /*
880 * XXX should we also nuke any default routers in the kernel, by
881 * going through them by rtalloc1()?
882 */
883 }
884
885 /*
886 * Look up a matching default router list entry and remove it. Returns true if a
887 * matching entry was found, false otherwise.
888 */
889 bool
defrouter_remove(struct in6_addr * addr,struct ifnet * ifp)890 defrouter_remove(struct in6_addr *addr, struct ifnet *ifp)
891 {
892 struct nd_defrouter *dr;
893
894 ND6_WLOCK();
895 dr = defrouter_lookup_locked(addr, ifp);
896 if (dr == NULL) {
897 ND6_WUNLOCK();
898 return (false);
899 }
900
901 defrouter_unlink(dr, NULL);
902 ND6_WUNLOCK();
903 defrouter_del(dr);
904 defrouter_rele(dr);
905 return (true);
906 }
907
908 /*
909 * for default router selection
910 * regards router-preference field as a 2-bit signed integer
911 */
912 static int
rtpref(struct nd_defrouter * dr)913 rtpref(struct nd_defrouter *dr)
914 {
915 switch (dr->raflags & ND_RA_FLAG_RTPREF_MASK) {
916 case ND_RA_FLAG_RTPREF_HIGH:
917 return (RTPREF_HIGH);
918 case ND_RA_FLAG_RTPREF_MEDIUM:
919 case ND_RA_FLAG_RTPREF_RSV:
920 return (RTPREF_MEDIUM);
921 case ND_RA_FLAG_RTPREF_LOW:
922 return (RTPREF_LOW);
923 default:
924 /*
925 * This case should never happen. If it did, it would mean a
926 * serious bug of kernel internal. We thus always bark here.
927 * Or, can we even panic?
928 */
929 log(LOG_ERR, "rtpref: impossible RA flag %x\n", dr->raflags);
930 return (RTPREF_INVALID);
931 }
932 /* NOTREACHED */
933 }
934
935 static bool
is_dr_reachable(const struct nd_defrouter * dr)936 is_dr_reachable(const struct nd_defrouter *dr) {
937 struct llentry *ln = NULL;
938
939 ln = nd6_lookup(&dr->rtaddr, LLE_SF(AF_INET6, 0), dr->ifp);
940 if (ln == NULL)
941 return (false);
942 bool reachable = ND6_IS_LLINFO_PROBREACH(ln);
943 LLE_RUNLOCK(ln);
944 return reachable;
945 }
946
947 /*
948 * Default Router Selection according to Section 6.3.6 of RFC 2461 and
949 * draft-ietf-ipngwg-router-selection:
950 * 1) Routers that are reachable or probably reachable should be preferred.
951 * If we have more than one (probably) reachable router, prefer ones
952 * with the highest router preference.
953 * 2) When no routers on the list are known to be reachable or
954 * probably reachable, routers SHOULD be selected in a round-robin
955 * fashion, regardless of router preference values.
956 * 3) If the Default Router List is empty, assume that all
957 * destinations are on-link.
958 *
959 * We assume nd_defrouter is sorted by router preference value.
960 * Since the code below covers both with and without router preference cases,
961 * we do not need to classify the cases by ifdef.
962 *
963 * At this moment, we do not try to install more than one default router,
964 * even when the multipath routing is available, because we're not sure about
965 * the benefits for stub hosts comparing to the risk of making the code
966 * complicated and the possibility of introducing bugs.
967 *
968 * We maintain a single list of routers for multiple FIBs, only considering one
969 * at a time based on the receiving interface's FIB. If @fibnum is RT_ALL_FIBS,
970 * we do the whole thing multiple times.
971 */
972 void
defrouter_select_fib(int fibnum)973 defrouter_select_fib(int fibnum)
974 {
975 struct epoch_tracker et;
976 struct nd_defrouter *dr, *selected_dr, *installed_dr;
977
978 if (fibnum == RT_ALL_FIBS) {
979 for (fibnum = 0; fibnum < rt_numfibs; fibnum++) {
980 defrouter_select_fib(fibnum);
981 }
982 return;
983 }
984
985 ND6_RLOCK();
986 /*
987 * Let's handle easy case (3) first:
988 * If default router list is empty, there's nothing to be done.
989 */
990 if (TAILQ_EMPTY(&V_nd6_defrouter)) {
991 ND6_RUNLOCK();
992 return;
993 }
994
995 /*
996 * Search for a (probably) reachable router from the list.
997 * We just pick up the first reachable one (if any), assuming that
998 * the ordering rule of the list described in defrtrlist_update().
999 */
1000 selected_dr = installed_dr = NULL;
1001 NET_EPOCH_ENTER(et);
1002 TAILQ_FOREACH(dr, &V_nd6_defrouter, dr_entry) {
1003 if (dr->ifp->if_fib != fibnum)
1004 continue;
1005
1006 if (selected_dr == NULL && is_dr_reachable(dr)) {
1007 selected_dr = dr;
1008 defrouter_ref(selected_dr);
1009 }
1010
1011 if (dr->installed) {
1012 if (installed_dr == NULL) {
1013 installed_dr = dr;
1014 defrouter_ref(installed_dr);
1015 } else {
1016 /*
1017 * this should not happen.
1018 * warn for diagnosis.
1019 */
1020 log(LOG_ERR, "defrouter_select_fib: more than "
1021 "one router is installed\n");
1022 }
1023 }
1024 }
1025
1026 /*
1027 * If none of the default routers was found to be reachable,
1028 * round-robin the list regardless of preference.
1029 * Otherwise, if we have an installed router, check if the selected
1030 * (reachable) router should really be preferred to the installed one.
1031 * We only prefer the new router when the old one is not reachable
1032 * or when the new one has a really higher preference value.
1033 */
1034 if (selected_dr == NULL) {
1035 if (installed_dr == NULL ||
1036 TAILQ_NEXT(installed_dr, dr_entry) == NULL)
1037 dr = TAILQ_FIRST(&V_nd6_defrouter);
1038 else
1039 dr = TAILQ_NEXT(installed_dr, dr_entry);
1040
1041 /* Ensure we select a router for this FIB. */
1042 TAILQ_FOREACH_FROM(dr, &V_nd6_defrouter, dr_entry) {
1043 if (dr->ifp->if_fib == fibnum) {
1044 selected_dr = dr;
1045 defrouter_ref(selected_dr);
1046 break;
1047 }
1048 }
1049 } else if (installed_dr != NULL) {
1050 if (is_dr_reachable(installed_dr) &&
1051 rtpref(selected_dr) <= rtpref(installed_dr)) {
1052 defrouter_rele(selected_dr);
1053 selected_dr = installed_dr;
1054 }
1055 }
1056 ND6_RUNLOCK();
1057
1058 /*
1059 * If we selected a router for this FIB and it's different
1060 * than the installed one, remove the installed router and
1061 * install the selected one in its place.
1062 */
1063 if (installed_dr != selected_dr) {
1064 if (installed_dr != NULL) {
1065 defrouter_delreq(installed_dr);
1066 defrouter_rele(installed_dr);
1067 }
1068 if (selected_dr != NULL)
1069 defrouter_addreq(selected_dr);
1070 }
1071 if (selected_dr != NULL)
1072 defrouter_rele(selected_dr);
1073 NET_EPOCH_EXIT(et);
1074 }
1075
1076 static struct nd_defrouter *
defrtrlist_update(struct nd_defrouter * new)1077 defrtrlist_update(struct nd_defrouter *new)
1078 {
1079 struct nd_defrouter *dr, *n;
1080 uint64_t genid;
1081 int oldpref;
1082 bool writelocked;
1083
1084 if (new->rtlifetime == 0) {
1085 defrouter_remove(&new->rtaddr, new->ifp);
1086 return (NULL);
1087 }
1088
1089 ND6_RLOCK();
1090 writelocked = false;
1091 restart:
1092 dr = defrouter_lookup_locked(&new->rtaddr, new->ifp);
1093 if (dr != NULL) {
1094 oldpref = rtpref(dr);
1095
1096 /* override */
1097 dr->raflags = new->raflags; /* XXX flag check */
1098 dr->rtlifetime = new->rtlifetime;
1099 dr->expire = new->expire;
1100
1101 /*
1102 * If the preference does not change, there's no need
1103 * to sort the entries. Also make sure the selected
1104 * router is still installed in the kernel.
1105 */
1106 if (dr->installed && rtpref(new) == oldpref) {
1107 if (writelocked)
1108 ND6_WUNLOCK();
1109 else
1110 ND6_RUNLOCK();
1111 return (dr);
1112 }
1113 }
1114
1115 /*
1116 * The router needs to be reinserted into the default router
1117 * list, so upgrade to a write lock. If that fails and the list
1118 * has potentially changed while the lock was dropped, we'll
1119 * redo the lookup with the write lock held.
1120 */
1121 if (!writelocked) {
1122 writelocked = true;
1123 if (!ND6_TRY_UPGRADE()) {
1124 genid = V_nd6_list_genid;
1125 ND6_RUNLOCK();
1126 ND6_WLOCK();
1127 if (genid != V_nd6_list_genid)
1128 goto restart;
1129 }
1130 }
1131
1132 if (dr != NULL) {
1133 /*
1134 * The preferred router may have changed, so relocate this
1135 * router.
1136 */
1137 TAILQ_REMOVE(&V_nd6_defrouter, dr, dr_entry);
1138 n = dr;
1139 } else {
1140 n = malloc(sizeof(*n), M_IP6NDP, M_NOWAIT | M_ZERO);
1141 if (n == NULL) {
1142 ND6_WUNLOCK();
1143 return (NULL);
1144 }
1145 memcpy(n, new, sizeof(*n));
1146 /* Initialize with an extra reference for the caller. */
1147 refcount_init(&n->refcnt, 2);
1148 }
1149
1150 /*
1151 * Insert the new router in the Default Router List;
1152 * The Default Router List should be in the descending order
1153 * of router-preferece. Routers with the same preference are
1154 * sorted in the arriving time order.
1155 */
1156
1157 /* insert at the end of the group */
1158 TAILQ_FOREACH(dr, &V_nd6_defrouter, dr_entry) {
1159 if (rtpref(n) > rtpref(dr))
1160 break;
1161 }
1162 if (dr != NULL)
1163 TAILQ_INSERT_BEFORE(dr, n, dr_entry);
1164 else
1165 TAILQ_INSERT_TAIL(&V_nd6_defrouter, n, dr_entry);
1166 V_nd6_list_genid++;
1167 ND6_WUNLOCK();
1168
1169 defrouter_select_fib(new->ifp->if_fib);
1170
1171 return (n);
1172 }
1173
1174 static void
in6_init_prefix_ltimes(struct nd_prefix * ndpr)1175 in6_init_prefix_ltimes(struct nd_prefix *ndpr)
1176 {
1177 ndpr->ndpr_preferred = in6_expire_time(ndpr->ndpr_pltime);
1178 ndpr->ndpr_expire = in6_expire_time(ndpr->ndpr_vltime);
1179 }
1180
1181 static void
in6_init_address_ltimes(struct nd_prefix * new,struct in6_addrlifetime * lt6)1182 in6_init_address_ltimes(struct nd_prefix *new, struct in6_addrlifetime *lt6)
1183 {
1184 lt6->ia6t_preferred = in6_expire_time(lt6->ia6t_pltime);
1185 lt6->ia6t_expire = in6_expire_time(lt6->ia6t_vltime);
1186 }
1187
1188 static struct in6_ifaddr *
in6_ifadd(struct nd_prefixctl * pr,int mcast)1189 in6_ifadd(struct nd_prefixctl *pr, int mcast)
1190 {
1191 struct ifnet *ifp = pr->ndpr_ifp;
1192 struct ifaddr *ifa;
1193 struct in6_aliasreq ifra;
1194 struct in6_ifaddr *ia = NULL, *ib = NULL;
1195 int error, plen0;
1196 struct in6_addr *ifid_addr = NULL, mask, newaddr;
1197 int prefixlen = pr->ndpr_plen;
1198 int updateflags;
1199 char ip6buf[INET6_ADDRSTRLEN];
1200
1201 in6_prefixlen2mask(&mask, prefixlen);
1202
1203 /*
1204 * find a link-local address (will be interface ID).
1205 * Is it really mandatory? Theoretically, a global or a site-local
1206 * address can be configured without a link-local address, if we
1207 * have a unique interface identifier...
1208 *
1209 * it is not mandatory to have a link-local address, we can generate
1210 * interface identifier on the fly. we do this because:
1211 * (1) it should be the easiest way to find interface identifier.
1212 * (2) RFC2462 5.4 suggesting the use of the same interface identifier
1213 * for multiple addresses on a single interface, and possible shortcut
1214 * of DAD. we omitted DAD for this reason in the past.
1215 * (3) a user can prevent autoconfiguration of global address
1216 * by removing link-local address by hand (this is partly because we
1217 * don't have other way to control the use of IPv6 on an interface.
1218 * this has been our design choice - cf. NRL's "ifconfig auto").
1219 * (4) it is easier to manage when an interface has addresses
1220 * with the same interface identifier, than to have multiple addresses
1221 * with different interface identifiers.
1222 *
1223 * If using stable privacy generation, generate a new address with
1224 * the algorithm specified in RFC 7217 section 5
1225 */
1226
1227 /* make ifaddr */
1228 in6_prepare_ifra(&ifra, &pr->ndpr_prefix.sin6_addr, &mask);
1229
1230 if (ifp->if_inet6->nd_flags & ND6_IFF_STABLEADDR) {
1231 memcpy(&newaddr, &pr->ndpr_prefix.sin6_addr, sizeof(pr->ndpr_prefix.sin6_addr));
1232
1233 if(!in6_get_stableifid(ifp, &newaddr, prefixlen))
1234 return NULL;
1235 } else {
1236 ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp, 0); /* 0 is OK? */
1237 if (ifa) {
1238 ib = (struct in6_ifaddr *)ifa;
1239 ifid_addr = &ib->ia_addr.sin6_addr;
1240
1241 /* prefixlen + ifidlen must be equal to 128 */
1242 plen0 = in6_mask2len(&ib->ia_prefixmask.sin6_addr, NULL);
1243 if (prefixlen != plen0) {
1244 ifa_free(ifa);
1245 ifid_addr = NULL;
1246 nd6log((LOG_DEBUG,
1247 "%s: wrong prefixlen for %s (prefix=%d ifid=%d)\n",
1248 __func__, if_name(ifp), prefixlen, 128 - plen0));
1249 }
1250 }
1251
1252 /* No suitable LL address, get the ifid directly */
1253 if (ifid_addr == NULL) {
1254 ifa = ifa_alloc(sizeof(struct in6_ifaddr), M_NOWAIT);
1255 if (ifa != NULL) {
1256 ib = (struct in6_ifaddr *)ifa;
1257 ifid_addr = &ib->ia_addr.sin6_addr;
1258 if(in6_get_ifid(ifp, NULL, ifid_addr) != 0) {
1259 nd6log((LOG_DEBUG,
1260 "%s: failed to get ifid for %s\n",
1261 __func__, if_name(ifp)));
1262 ifa_free(ifa);
1263 ifid_addr = NULL;
1264 }
1265 }
1266 }
1267
1268 if (ifid_addr == NULL) {
1269 nd6log((LOG_INFO,
1270 "%s: could not determine ifid for %s\n",
1271 __func__, if_name(ifp)));
1272 return NULL;
1273 }
1274
1275 memcpy(&newaddr, &ib->ia_addr.sin6_addr, sizeof(ib->ia_addr.sin6_addr));
1276 ifa_free(ifa);
1277 }
1278
1279 IN6_MASK_ADDR(&ifra.ifra_addr.sin6_addr, &mask);
1280 /* interface ID */
1281 ifra.ifra_addr.sin6_addr.s6_addr32[0] |= (newaddr.s6_addr32[0] & ~mask.s6_addr32[0]);
1282 ifra.ifra_addr.sin6_addr.s6_addr32[1] |= (newaddr.s6_addr32[1] & ~mask.s6_addr32[1]);
1283 ifra.ifra_addr.sin6_addr.s6_addr32[2] |= (newaddr.s6_addr32[2] & ~mask.s6_addr32[2]);
1284 ifra.ifra_addr.sin6_addr.s6_addr32[3] |= (newaddr.s6_addr32[3] & ~mask.s6_addr32[3]);
1285
1286 /* lifetimes. */
1287 ifra.ifra_lifetime.ia6t_vltime = pr->ndpr_vltime;
1288 ifra.ifra_lifetime.ia6t_pltime = pr->ndpr_pltime;
1289
1290 /* XXX: scope zone ID? */
1291
1292 ifra.ifra_flags |= IN6_IFF_AUTOCONF; /* obey autoconf */
1293
1294 /*
1295 * Make sure that we do not have this address already. This should
1296 * usually not happen, but we can still see this case, e.g., if we
1297 * have manually configured the exact address to be configured.
1298 */
1299 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp,
1300 &ifra.ifra_addr.sin6_addr);
1301 if (ifa != NULL) {
1302 ifa_free(ifa);
1303 /* this should be rare enough to make an explicit log */
1304 log(LOG_INFO, "in6_ifadd: %s is already configured\n",
1305 ip6_sprintf(ip6buf, &ifra.ifra_addr.sin6_addr));
1306 return (NULL);
1307 }
1308
1309 /*
1310 * Allocate ifaddr structure, link into chain, etc.
1311 * If we are going to create a new address upon receiving a multicasted
1312 * RA, we need to impose a random delay before starting DAD.
1313 * [draft-ietf-ipv6-rfc2462bis-02.txt, Section 5.4.2]
1314 */
1315 updateflags = 0;
1316 if (mcast)
1317 updateflags |= IN6_IFAUPDATE_DADDELAY;
1318 if ((error = in6_update_ifa(ifp, &ifra, NULL, updateflags)) != 0) {
1319 nd6log((LOG_ERR,
1320 "%s: failed to make ifaddr %s on %s (errno=%d)\n", __func__,
1321 ip6_sprintf(ip6buf, &ifra.ifra_addr.sin6_addr),
1322 if_name(ifp), error));
1323 return (NULL); /* ifaddr must not have been allocated. */
1324 }
1325
1326 ia = in6ifa_ifpwithaddr(ifp, &ifra.ifra_addr.sin6_addr);
1327 /*
1328 * XXXRW: Assumption of non-NULLness here might not be true with
1329 * fine-grained locking -- should we validate it? Or just return
1330 * earlier ifa rather than looking it up again?
1331 */
1332 return (ia); /* this is always non-NULL and referenced. */
1333 }
1334
1335 static struct nd_prefix *
nd6_prefix_lookup_locked(struct nd_prefixctl * key)1336 nd6_prefix_lookup_locked(struct nd_prefixctl *key)
1337 {
1338 struct nd_prefix *search;
1339
1340 ND6_LOCK_ASSERT();
1341
1342 LIST_FOREACH(search, &V_nd_prefix, ndpr_entry) {
1343 if (key->ndpr_ifp == search->ndpr_ifp &&
1344 key->ndpr_plen == search->ndpr_plen &&
1345 in6_are_prefix_equal(&key->ndpr_prefix.sin6_addr,
1346 &search->ndpr_prefix.sin6_addr, key->ndpr_plen)) {
1347 nd6_prefix_ref(search);
1348 break;
1349 }
1350 }
1351 return (search);
1352 }
1353
1354 struct nd_prefix *
nd6_prefix_lookup(struct nd_prefixctl * key)1355 nd6_prefix_lookup(struct nd_prefixctl *key)
1356 {
1357 struct nd_prefix *search;
1358
1359 ND6_RLOCK();
1360 search = nd6_prefix_lookup_locked(key);
1361 ND6_RUNLOCK();
1362 return (search);
1363 }
1364
1365 void
nd6_prefix_ref(struct nd_prefix * pr)1366 nd6_prefix_ref(struct nd_prefix *pr)
1367 {
1368
1369 refcount_acquire(&pr->ndpr_refcnt);
1370 }
1371
1372 void
nd6_prefix_rele(struct nd_prefix * pr)1373 nd6_prefix_rele(struct nd_prefix *pr)
1374 {
1375
1376 if (refcount_release(&pr->ndpr_refcnt)) {
1377 KASSERT(LIST_EMPTY(&pr->ndpr_advrtrs),
1378 ("prefix %p has advertising routers", pr));
1379 free(pr, M_IP6NDP);
1380 }
1381 }
1382
1383 int
nd6_prelist_add(struct nd_prefixctl * pr,struct nd_defrouter * dr,struct nd_prefix ** newp)1384 nd6_prelist_add(struct nd_prefixctl *pr, struct nd_defrouter *dr,
1385 struct nd_prefix **newp)
1386 {
1387 struct nd_prefix *new;
1388 char ip6buf[INET6_ADDRSTRLEN];
1389 int error;
1390
1391 new = malloc(sizeof(*new), M_IP6NDP, M_NOWAIT | M_ZERO);
1392 if (new == NULL)
1393 return (ENOMEM);
1394 refcount_init(&new->ndpr_refcnt, newp != NULL ? 2 : 1);
1395 new->ndpr_ifp = pr->ndpr_ifp;
1396 new->ndpr_prefix = pr->ndpr_prefix;
1397 new->ndpr_plen = pr->ndpr_plen;
1398 new->ndpr_vltime = pr->ndpr_vltime;
1399 new->ndpr_pltime = pr->ndpr_pltime;
1400 new->ndpr_flags = pr->ndpr_flags;
1401 new->ndpr_lastupdate = time_uptime;
1402 in6_init_prefix_ltimes(new);
1403
1404 /* initialization */
1405 LIST_INIT(&new->ndpr_advrtrs);
1406 in6_prefixlen2mask(&new->ndpr_mask, new->ndpr_plen);
1407 /* make prefix in the canonical form */
1408 IN6_MASK_ADDR(&new->ndpr_prefix.sin6_addr, &new->ndpr_mask);
1409
1410 ND6_WLOCK();
1411 LIST_INSERT_HEAD(&V_nd_prefix, new, ndpr_entry);
1412 V_nd6_list_genid++;
1413 ND6_WUNLOCK();
1414
1415 /* ND_OPT_PI_FLAG_ONLINK processing */
1416 if (new->ndpr_raf_onlink) {
1417 struct epoch_tracker et;
1418
1419 ND6_ONLINK_LOCK();
1420 NET_EPOCH_ENTER(et);
1421 if ((error = nd6_prefix_onlink(new)) != 0) {
1422 nd6log((LOG_ERR, "%s: failed to make the prefix %s/%d "
1423 "on-link on %s (errno=%d)\n", __func__,
1424 ip6_sprintf(ip6buf, &pr->ndpr_prefix.sin6_addr),
1425 pr->ndpr_plen, if_name(pr->ndpr_ifp), error));
1426 /* proceed anyway. XXX: is it correct? */
1427 }
1428 NET_EPOCH_EXIT(et);
1429 ND6_ONLINK_UNLOCK();
1430 }
1431
1432 if (dr != NULL)
1433 pfxrtr_add(new, dr);
1434 if (newp != NULL)
1435 *newp = new;
1436 return (0);
1437 }
1438
1439 /*
1440 * Remove a prefix from the prefix list and optionally stash it in a
1441 * caller-provided list.
1442 *
1443 * The ND6 lock must be held.
1444 */
1445 void
nd6_prefix_unlink(struct nd_prefix * pr,struct nd_prhead * list)1446 nd6_prefix_unlink(struct nd_prefix *pr, struct nd_prhead *list)
1447 {
1448
1449 ND6_WLOCK_ASSERT();
1450
1451 LIST_REMOVE(pr, ndpr_entry);
1452 V_nd6_list_genid++;
1453 if (list != NULL)
1454 LIST_INSERT_HEAD(list, pr, ndpr_entry);
1455 }
1456
1457 /*
1458 * Free an unlinked prefix, first marking it off-link if necessary.
1459 */
1460 void
nd6_prefix_del(struct nd_prefix * pr)1461 nd6_prefix_del(struct nd_prefix *pr)
1462 {
1463 struct nd_pfxrouter *pfr, *next;
1464 int e;
1465 char ip6buf[INET6_ADDRSTRLEN];
1466
1467 KASSERT(pr->ndpr_addrcnt == 0,
1468 ("prefix %p has referencing addresses", pr));
1469 ND6_UNLOCK_ASSERT();
1470
1471 /*
1472 * Though these flags are now meaningless, we'd rather keep the value
1473 * of pr->ndpr_raf_onlink and pr->ndpr_raf_auto not to confuse users
1474 * when executing "ndp -p".
1475 */
1476 if ((pr->ndpr_stateflags & NDPRF_ONLINK) != 0) {
1477 ND6_ONLINK_LOCK();
1478 if ((e = nd6_prefix_offlink(pr)) != 0) {
1479 nd6log((LOG_ERR,
1480 "%s: failed to make the prefix %s/%d offlink on %s "
1481 "(errno=%d)\n", __func__,
1482 ip6_sprintf(ip6buf, &pr->ndpr_prefix.sin6_addr),
1483 pr->ndpr_plen, if_name(pr->ndpr_ifp), e));
1484 /* what should we do? */
1485 }
1486 ND6_ONLINK_UNLOCK();
1487 }
1488
1489 /* Release references to routers that have advertised this prefix. */
1490 ND6_WLOCK();
1491 LIST_FOREACH_SAFE(pfr, &pr->ndpr_advrtrs, pfr_entry, next)
1492 pfxrtr_del(pfr);
1493 ND6_WUNLOCK();
1494
1495 nd6_prefix_rele(pr);
1496
1497 pfxlist_onlink_check();
1498 }
1499
1500 static int
prelist_update(struct nd_prefixctl * new,struct nd_defrouter * dr,bool auth,int mcast)1501 prelist_update(struct nd_prefixctl *new, struct nd_defrouter *dr,
1502 bool auth, int mcast)
1503 {
1504 struct in6_ifaddr *ia6 = NULL, *ia6_match = NULL;
1505 struct ifaddr *ifa;
1506 struct ifnet *ifp = new->ndpr_ifp;
1507 struct nd_prefix *pr;
1508 int error = 0;
1509 struct in6_addrlifetime lt6_tmp;
1510 char ip6buf[INET6_ADDRSTRLEN];
1511 bool has_temporary = false;
1512
1513 NET_EPOCH_ASSERT();
1514
1515 if ((pr = nd6_prefix_lookup(new)) != NULL) {
1516 /*
1517 * nd6_prefix_lookup() ensures that pr and new have the same
1518 * prefix on a same interface.
1519 */
1520
1521 /*
1522 * Update prefix information. Note that the on-link (L) bit
1523 * and the autonomous (A) bit should NOT be changed from 1
1524 * to 0.
1525 */
1526 if (new->ndpr_raf_onlink == 1)
1527 pr->ndpr_raf_onlink = 1;
1528 if (new->ndpr_raf_auto == 1)
1529 pr->ndpr_raf_auto = 1;
1530 if (new->ndpr_raf_onlink) {
1531 pr->ndpr_vltime = new->ndpr_vltime;
1532 pr->ndpr_pltime = new->ndpr_pltime;
1533 in6_init_prefix_ltimes(pr);
1534 pr->ndpr_lastupdate = time_uptime;
1535 }
1536
1537 if (new->ndpr_raf_onlink &&
1538 (pr->ndpr_stateflags & NDPRF_ONLINK) == 0) {
1539 ND6_ONLINK_LOCK();
1540 if ((error = nd6_prefix_onlink(pr)) != 0) {
1541 nd6log((LOG_ERR,
1542 "%s: failed to make the prefix %s/%d "
1543 "on-link on %s (errno=%d)\n", __func__,
1544 ip6_sprintf(ip6buf,
1545 &pr->ndpr_prefix.sin6_addr),
1546 pr->ndpr_plen, if_name(pr->ndpr_ifp),
1547 error));
1548 /* proceed anyway. XXX: is it correct? */
1549 }
1550 ND6_ONLINK_UNLOCK();
1551 }
1552
1553 if (dr != NULL)
1554 pfxrtr_add(pr, dr);
1555 } else {
1556 if (new->ndpr_vltime == 0)
1557 goto end;
1558 if (new->ndpr_raf_onlink == 0 && new->ndpr_raf_auto == 0)
1559 goto end;
1560
1561 error = nd6_prelist_add(new, dr, &pr);
1562 if (error != 0) {
1563 nd6log((LOG_NOTICE, "%s: nd6_prelist_add() failed for "
1564 "the prefix %s/%d on %s (errno=%d)\n", __func__,
1565 ip6_sprintf(ip6buf, &new->ndpr_prefix.sin6_addr),
1566 new->ndpr_plen, if_name(new->ndpr_ifp), error));
1567 goto end; /* we should just give up in this case. */
1568 }
1569
1570 /*
1571 * XXX: from the ND point of view, we can ignore a prefix
1572 * with the on-link bit being zero. However, we need a
1573 * prefix structure for references from autoconfigured
1574 * addresses. Thus, we explicitly make sure that the prefix
1575 * itself expires now.
1576 */
1577 if (pr->ndpr_raf_onlink == 0) {
1578 pr->ndpr_vltime = 0;
1579 pr->ndpr_pltime = 0;
1580 in6_init_prefix_ltimes(pr);
1581 }
1582 }
1583
1584 /*
1585 * Address autoconfiguration based on Section 5.5.3 of RFC 2462.
1586 * Note that pr must be non NULL at this point.
1587 */
1588
1589 /* 5.5.3 (a). Ignore the prefix without the A bit set. */
1590 if (!new->ndpr_raf_auto)
1591 goto end;
1592
1593 /*
1594 * 5.5.3 (b). the link-local prefix should have been ignored in
1595 * nd6_ra_input.
1596 */
1597
1598 /* 5.5.3 (c). Consistency check on lifetimes: pltime <= vltime. */
1599 if (new->ndpr_pltime > new->ndpr_vltime) {
1600 error = EINVAL; /* XXX: won't be used */
1601 goto end;
1602 }
1603
1604 /*
1605 * 5.5.3 (d). If the prefix advertised is not equal to the prefix of
1606 * an address configured by stateless autoconfiguration already in the
1607 * list of addresses associated with the interface, and the Valid
1608 * Lifetime is not 0, form an address. We first check if we have
1609 * a matching prefix.
1610 * Note: we apply a clarification in rfc2462bis-02 here. We only
1611 * consider autoconfigured addresses while RFC2462 simply said
1612 * "address".
1613 */
1614 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1615 struct in6_ifaddr *ifa6;
1616 u_int32_t remaininglifetime;
1617
1618 if (ifa->ifa_addr->sa_family != AF_INET6)
1619 continue;
1620
1621 ifa6 = (struct in6_ifaddr *)ifa;
1622
1623 /*
1624 * We only consider autoconfigured addresses as per rfc2462bis.
1625 */
1626 if (!(ifa6->ia6_flags & IN6_IFF_AUTOCONF))
1627 continue;
1628
1629 /*
1630 * Spec is not clear here, but I believe we should concentrate
1631 * on unicast (i.e. not anycast) addresses.
1632 * XXX: other ia6_flags? detached or duplicated?
1633 */
1634 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0)
1635 continue;
1636
1637 /*
1638 * Ignore the address if it is not associated with a prefix
1639 * or is associated with a prefix that is different from this
1640 * one. (pr is never NULL here)
1641 */
1642 if (ifa6->ia6_ndpr != pr)
1643 continue;
1644
1645 /*
1646 * An already autoconfigured address matched. Now that we
1647 * are sure there is at least one matched address, we can
1648 * proceed to 5.5.3. (e): update the lifetimes according to the
1649 * "two hours" rule and the privacy extension.
1650 * We apply some clarifications in rfc2462bis:
1651 * - use remaininglifetime instead of storedlifetime as a
1652 * variable name
1653 * - remove the dead code in the "two-hour" rule
1654 */
1655 #define TWOHOUR (120*60)
1656 lt6_tmp = ifa6->ia6_lifetime;
1657
1658 if (lt6_tmp.ia6t_vltime == ND6_INFINITE_LIFETIME)
1659 remaininglifetime = ND6_INFINITE_LIFETIME;
1660 else if (time_uptime - ifa6->ia6_updatetime >
1661 lt6_tmp.ia6t_vltime) {
1662 /*
1663 * The case of "invalid" address. We should usually
1664 * not see this case.
1665 */
1666 remaininglifetime = 0;
1667 } else
1668 remaininglifetime = lt6_tmp.ia6t_vltime -
1669 (time_uptime - ifa6->ia6_updatetime);
1670
1671 /* when not updating, keep the current stored lifetime. */
1672 lt6_tmp.ia6t_vltime = remaininglifetime;
1673
1674 if (TWOHOUR < new->ndpr_vltime ||
1675 remaininglifetime < new->ndpr_vltime) {
1676 lt6_tmp.ia6t_vltime = new->ndpr_vltime;
1677 } else if (remaininglifetime <= TWOHOUR) {
1678 if (auth) {
1679 lt6_tmp.ia6t_vltime = new->ndpr_vltime;
1680 }
1681 } else {
1682 /*
1683 * new->ndpr_vltime <= TWOHOUR &&
1684 * TWOHOUR < remaininglifetime
1685 */
1686 lt6_tmp.ia6t_vltime = TWOHOUR;
1687 }
1688
1689 /* The 2 hour rule is not imposed for preferred lifetime. */
1690 lt6_tmp.ia6t_pltime = new->ndpr_pltime;
1691
1692 in6_init_address_ltimes(pr, <6_tmp);
1693
1694 /*
1695 * We need to treat lifetimes for temporary addresses
1696 * differently, according to
1697 * draft-ietf-ipv6-privacy-addrs-v2-01.txt 3.3 (1);
1698 * we only update the lifetimes when they are in the maximum
1699 * intervals.
1700 */
1701 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0) {
1702 u_int32_t maxvltime, maxpltime;
1703
1704 /*
1705 * if stable addresses (RFC 7217) are enabled, mark that a temporary address has been found
1706 * to avoid generating uneeded extra ones.
1707 */
1708 if (ifp->if_inet6->nd_flags & ND6_IFF_STABLEADDR)
1709 has_temporary = true;
1710
1711 if (V_ip6_temp_valid_lifetime >
1712 (u_int32_t)((time_uptime - ifa6->ia6_createtime) +
1713 V_ip6_desync_factor)) {
1714 maxvltime = V_ip6_temp_valid_lifetime -
1715 (time_uptime - ifa6->ia6_createtime) -
1716 V_ip6_desync_factor;
1717 } else
1718 maxvltime = 0;
1719 if (V_ip6_temp_preferred_lifetime >
1720 (u_int32_t)((time_uptime - ifa6->ia6_createtime) +
1721 V_ip6_desync_factor)) {
1722 maxpltime = V_ip6_temp_preferred_lifetime -
1723 (time_uptime - ifa6->ia6_createtime) -
1724 V_ip6_desync_factor;
1725 } else
1726 maxpltime = 0;
1727
1728 if (lt6_tmp.ia6t_vltime == ND6_INFINITE_LIFETIME ||
1729 lt6_tmp.ia6t_vltime > maxvltime) {
1730 lt6_tmp.ia6t_vltime = maxvltime;
1731 }
1732 if (lt6_tmp.ia6t_pltime == ND6_INFINITE_LIFETIME ||
1733 lt6_tmp.ia6t_pltime > maxpltime) {
1734 lt6_tmp.ia6t_pltime = maxpltime;
1735 }
1736 }
1737 ifa6->ia6_lifetime = lt6_tmp;
1738 ifa6->ia6_updatetime = time_uptime;
1739
1740 /*
1741 * If using stable addresses (RFC 7217) and we still have retries to perform, ignore
1742 * addresses already marked as duplicated, since a new one will be generated.
1743 * Also ignore addresses marked as temporary, since their generation is orthogonal to
1744 * opaque stable ones.
1745 *
1746 * There is a small race condition, in that the dad_counter could be incremented
1747 * between here and when a new address is generated, but this will cause that generation
1748 * to fail and no further retries should happen.
1749 */
1750 if (ifp->if_inet6->nd_flags & ND6_IFF_STABLEADDR &&
1751 atomic_load_int(&DAD_FAILURES(ifp)) <= V_ip6_stableaddr_maxretries &&
1752 ifa6->ia6_flags & (IN6_IFF_DUPLICATED | IN6_IFF_TEMPORARY))
1753 continue;
1754
1755 if (ia6_match == NULL) /* remember the first one */
1756 ia6_match = ifa6;
1757 }
1758 if (ia6_match == NULL && new->ndpr_vltime) {
1759 int ifidlen;
1760
1761 /*
1762 * 5.5.3 (d) (continued)
1763 * No address matched and the valid lifetime is non-zero.
1764 * Create a new address.
1765 */
1766
1767 /*
1768 * Prefix Length check:
1769 * If the sum of the prefix length and interface identifier
1770 * length does not equal 128 bits, the Prefix Information
1771 * option MUST be ignored. The length of the interface
1772 * identifier is defined in a separate link-type specific
1773 * document.
1774 */
1775 ifidlen = in6_if2idlen(ifp);
1776 if (ifidlen < 0) {
1777 /* this should not happen, so we always log it. */
1778 log(LOG_ERR, "prelist_update: IFID undefined (%s)\n",
1779 if_name(ifp));
1780 goto end;
1781 }
1782 if (ifidlen + pr->ndpr_plen != 128) {
1783 nd6log((LOG_INFO,
1784 "%s: invalid prefixlen %d for %s, ignored\n",
1785 __func__, pr->ndpr_plen, if_name(ifp)));
1786 goto end;
1787 }
1788
1789 if ((ia6 = in6_ifadd(new, mcast)) != NULL) {
1790 /*
1791 * note that we should use pr (not new) for reference.
1792 */
1793 pr->ndpr_addrcnt++;
1794 ia6->ia6_ndpr = pr;
1795
1796 /*
1797 * RFC 3041 3.3 (2).
1798 * When a new public address is created as described
1799 * in RFC2462, also create a new temporary address.
1800 *
1801 * RFC 3041 3.5.
1802 * When an interface connects to a new link, a new
1803 * randomized interface identifier should be generated
1804 * immediately together with a new set of temporary
1805 * addresses. Thus, we specifiy 1 as the 2nd arg of
1806 * in6_tmpifadd().
1807 *
1808 * Skip this if a temporary address has been marked as
1809 * found (happens only if stable addresses (RFC 7217) is in use)
1810 */
1811 if (V_ip6_use_tempaddr && !has_temporary) {
1812 int e;
1813 if ((e = in6_tmpifadd(ia6, 1, 1)) != 0) {
1814 nd6log((LOG_NOTICE, "%s: failed to "
1815 "create a temporary address "
1816 "(errno=%d)\n", __func__, e));
1817 }
1818 }
1819 ifa_free(&ia6->ia_ifa);
1820
1821 /*
1822 * A newly added address might affect the status
1823 * of other addresses, so we check and update it.
1824 * XXX: what if address duplication happens?
1825 */
1826 pfxlist_onlink_check();
1827 } else {
1828 /* just set an error. do not bark here. */
1829 error = EADDRNOTAVAIL; /* XXX: might be unused. */
1830 }
1831 }
1832
1833 end:
1834 if (pr != NULL)
1835 nd6_prefix_rele(pr);
1836 return (error);
1837 }
1838
1839 /*
1840 * A supplement function used in the on-link detection below;
1841 * detect if a given prefix has a (probably) reachable advertising router.
1842 * XXX: lengthy function name...
1843 */
1844 static struct nd_pfxrouter *
find_pfxlist_reachable_router(struct nd_prefix * pr)1845 find_pfxlist_reachable_router(struct nd_prefix *pr)
1846 {
1847 struct epoch_tracker et;
1848 struct nd_pfxrouter *pfxrtr;
1849
1850 ND6_LOCK_ASSERT();
1851
1852 NET_EPOCH_ENTER(et);
1853 LIST_FOREACH(pfxrtr, &pr->ndpr_advrtrs, pfr_entry) {
1854 if (is_dr_reachable(pfxrtr->router))
1855 break;
1856 }
1857 NET_EPOCH_EXIT(et);
1858 return (pfxrtr);
1859 }
1860
1861 /*
1862 * Check if each prefix in the prefix list has at least one available router
1863 * that advertised the prefix (a router is "available" if its neighbor cache
1864 * entry is reachable or probably reachable).
1865 * If the check fails, the prefix may be off-link, because, for example,
1866 * we have moved from the network but the lifetime of the prefix has not
1867 * expired yet. So we should not use the prefix if there is another prefix
1868 * that has an available router.
1869 * But, if there is no prefix that has an available router, we still regard
1870 * all the prefixes as on-link. This is because we can't tell if all the
1871 * routers are simply dead or if we really moved from the network and there
1872 * is no router around us.
1873 */
1874 void
pfxlist_onlink_check(void)1875 pfxlist_onlink_check(void)
1876 {
1877 struct nd_prefix *pr;
1878 struct in6_ifaddr *ifa;
1879 struct nd_defrouter *dr;
1880 struct nd_pfxrouter *pfxrtr = NULL;
1881 struct rm_priotracker in6_ifa_tracker;
1882 uint64_t genid;
1883 uint32_t flags;
1884
1885 ND6_ONLINK_LOCK();
1886 ND6_RLOCK();
1887
1888 /*
1889 * Check if there is a prefix that has a reachable advertising
1890 * router.
1891 */
1892 LIST_FOREACH(pr, &V_nd_prefix, ndpr_entry) {
1893 if (pr->ndpr_raf_onlink && find_pfxlist_reachable_router(pr))
1894 break;
1895 }
1896
1897 /*
1898 * If we have no such prefix, check whether we still have a router
1899 * that does not advertise any prefixes.
1900 */
1901 if (pr == NULL) {
1902 TAILQ_FOREACH(dr, &V_nd6_defrouter, dr_entry) {
1903 struct nd_prefix *pr0;
1904
1905 LIST_FOREACH(pr0, &V_nd_prefix, ndpr_entry) {
1906 if ((pfxrtr = pfxrtr_lookup(pr0, dr)) != NULL)
1907 break;
1908 }
1909 if (pfxrtr != NULL)
1910 break;
1911 }
1912 }
1913 if (pr != NULL || (!TAILQ_EMPTY(&V_nd6_defrouter) && pfxrtr == NULL)) {
1914 /*
1915 * There is at least one prefix that has a reachable router,
1916 * or at least a router which probably does not advertise
1917 * any prefixes. The latter would be the case when we move
1918 * to a new link where we have a router that does not provide
1919 * prefixes and we configure an address by hand.
1920 * Detach prefixes which have no reachable advertising
1921 * router, and attach other prefixes.
1922 */
1923 LIST_FOREACH(pr, &V_nd_prefix, ndpr_entry) {
1924 /* XXX: a link-local prefix should never be detached */
1925 if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr) ||
1926 pr->ndpr_raf_onlink == 0 ||
1927 pr->ndpr_raf_auto == 0)
1928 continue;
1929
1930 if ((pr->ndpr_stateflags & NDPRF_DETACHED) == 0 &&
1931 find_pfxlist_reachable_router(pr) == NULL)
1932 pr->ndpr_stateflags |= NDPRF_DETACHED;
1933 else if ((pr->ndpr_stateflags & NDPRF_DETACHED) != 0 &&
1934 find_pfxlist_reachable_router(pr) != NULL)
1935 pr->ndpr_stateflags &= ~NDPRF_DETACHED;
1936 }
1937 } else {
1938 /* there is no prefix that has a reachable router */
1939 LIST_FOREACH(pr, &V_nd_prefix, ndpr_entry) {
1940 if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr) ||
1941 pr->ndpr_raf_onlink == 0 ||
1942 pr->ndpr_raf_auto == 0)
1943 continue;
1944 pr->ndpr_stateflags &= ~NDPRF_DETACHED;
1945 }
1946 }
1947
1948 /*
1949 * Remove each interface route associated with a (just) detached
1950 * prefix, and reinstall the interface route for a (just) attached
1951 * prefix. Note that all attempt of reinstallation does not
1952 * necessarily success, when a same prefix is shared among multiple
1953 * interfaces. Such cases will be handled in nd6_prefix_onlink,
1954 * so we don't have to care about them.
1955 */
1956 restart:
1957 LIST_FOREACH(pr, &V_nd_prefix, ndpr_entry) {
1958 char ip6buf[INET6_ADDRSTRLEN];
1959 int e;
1960
1961 if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr) ||
1962 pr->ndpr_raf_onlink == 0 ||
1963 pr->ndpr_raf_auto == 0)
1964 continue;
1965
1966 flags = pr->ndpr_stateflags & (NDPRF_DETACHED | NDPRF_ONLINK);
1967 if (flags == 0 || flags == (NDPRF_DETACHED | NDPRF_ONLINK)) {
1968 genid = V_nd6_list_genid;
1969 ND6_RUNLOCK();
1970 if ((flags & NDPRF_ONLINK) != 0 &&
1971 (e = nd6_prefix_offlink(pr)) != 0) {
1972 nd6log((LOG_ERR,
1973 "%s: failed to make %s/%d offlink "
1974 "(errno=%d)\n", __func__,
1975 ip6_sprintf(ip6buf,
1976 &pr->ndpr_prefix.sin6_addr),
1977 pr->ndpr_plen, e));
1978 } else if ((flags & NDPRF_ONLINK) == 0 &&
1979 (e = nd6_prefix_onlink(pr)) != 0) {
1980 nd6log((LOG_ERR,
1981 "%s: failed to make %s/%d onlink "
1982 "(errno=%d)\n", __func__,
1983 ip6_sprintf(ip6buf,
1984 &pr->ndpr_prefix.sin6_addr),
1985 pr->ndpr_plen, e));
1986 }
1987 ND6_RLOCK();
1988 if (genid != V_nd6_list_genid)
1989 goto restart;
1990 }
1991 }
1992
1993 /*
1994 * Changes on the prefix status might affect address status as well.
1995 * Make sure that all addresses derived from an attached prefix are
1996 * attached, and that all addresses derived from a detached prefix are
1997 * detached. Note, however, that a manually configured address should
1998 * always be attached.
1999 * The precise detection logic is same as the one for prefixes.
2000 */
2001 IN6_IFADDR_RLOCK(&in6_ifa_tracker);
2002 CK_STAILQ_FOREACH(ifa, &V_in6_ifaddrhead, ia_link) {
2003 if (!(ifa->ia6_flags & IN6_IFF_AUTOCONF))
2004 continue;
2005
2006 if (ifa->ia6_ndpr == NULL) {
2007 /*
2008 * This can happen when we first configure the address
2009 * (i.e. the address exists, but the prefix does not).
2010 * XXX: complicated relationships...
2011 */
2012 continue;
2013 }
2014
2015 if (find_pfxlist_reachable_router(ifa->ia6_ndpr))
2016 break;
2017 }
2018 if (ifa) {
2019 CK_STAILQ_FOREACH(ifa, &V_in6_ifaddrhead, ia_link) {
2020 if ((ifa->ia6_flags & IN6_IFF_AUTOCONF) == 0)
2021 continue;
2022
2023 if (ifa->ia6_ndpr == NULL) /* XXX: see above. */
2024 continue;
2025
2026 if (find_pfxlist_reachable_router(ifa->ia6_ndpr)) {
2027 if (ifa->ia6_flags & IN6_IFF_DETACHED) {
2028 ifa->ia6_flags &= ~IN6_IFF_DETACHED;
2029 ifa->ia6_flags |= IN6_IFF_TENTATIVE;
2030 nd6_dad_start((struct ifaddr *)ifa, 0);
2031 }
2032 } else {
2033 ifa->ia6_flags |= IN6_IFF_DETACHED;
2034 }
2035 }
2036 } else {
2037 CK_STAILQ_FOREACH(ifa, &V_in6_ifaddrhead, ia_link) {
2038 if ((ifa->ia6_flags & IN6_IFF_AUTOCONF) == 0)
2039 continue;
2040
2041 if (ifa->ia6_flags & IN6_IFF_DETACHED) {
2042 ifa->ia6_flags &= ~IN6_IFF_DETACHED;
2043 ifa->ia6_flags |= IN6_IFF_TENTATIVE;
2044 /* Do we need a delay in this case? */
2045 nd6_dad_start((struct ifaddr *)ifa, 0);
2046 }
2047 }
2048 }
2049 IN6_IFADDR_RUNLOCK(&in6_ifa_tracker);
2050 ND6_RUNLOCK();
2051 ND6_ONLINK_UNLOCK();
2052 }
2053
2054 /*
2055 * Add or remove interface route specified by @dst, @netmask and @ifp.
2056 * ifa can be NULL.
2057 * Returns 0 on success
2058 */
2059 static int
nd6_prefix_rtrequest(uint32_t fibnum,int cmd,struct sockaddr_in6 * dst,struct sockaddr_in6 * netmask,struct ifnet * ifp,struct ifaddr * ifa)2060 nd6_prefix_rtrequest(uint32_t fibnum, int cmd, struct sockaddr_in6 *dst,
2061 struct sockaddr_in6 *netmask, struct ifnet *ifp, struct ifaddr *ifa)
2062 {
2063 struct epoch_tracker et;
2064 int error;
2065
2066 /* Prepare gateway */
2067 struct sockaddr_dl_short sdl = {
2068 .sdl_family = AF_LINK,
2069 .sdl_len = sizeof(struct sockaddr_dl_short),
2070 .sdl_type = ifp->if_type,
2071 .sdl_index = ifp->if_index,
2072 };
2073
2074 struct rt_addrinfo info = {
2075 .rti_ifa = ifa,
2076 .rti_ifp = ifp,
2077 .rti_flags = RTF_PINNED | ((netmask != NULL) ? 0 : RTF_HOST),
2078 .rti_info = {
2079 [RTAX_DST] = (struct sockaddr *)dst,
2080 [RTAX_NETMASK] = (struct sockaddr *)netmask,
2081 [RTAX_GATEWAY] = (struct sockaddr *)&sdl,
2082 },
2083 };
2084 /* Don't set additional per-gw filters on removal */
2085
2086 NET_EPOCH_ENTER(et);
2087 error = rib_handle_ifaddr_info(fibnum, cmd, &info);
2088 NET_EPOCH_EXIT(et);
2089 return (error);
2090 }
2091
2092 static int
nd6_prefix_onlink_rtrequest(struct nd_prefix * pr,struct ifaddr * ifa)2093 nd6_prefix_onlink_rtrequest(struct nd_prefix *pr, struct ifaddr *ifa)
2094 {
2095 int error;
2096
2097 struct sockaddr_in6 mask6 = {
2098 .sin6_family = AF_INET6,
2099 .sin6_len = sizeof(struct sockaddr_in6),
2100 .sin6_addr = pr->ndpr_mask,
2101 };
2102 struct sockaddr_in6 *pmask6 = (pr->ndpr_plen != 128) ? &mask6 : NULL;
2103
2104 error = nd6_prefix_rtrequest(pr->ndpr_ifp->if_fib, RTM_ADD,
2105 &pr->ndpr_prefix, pmask6, pr->ndpr_ifp, ifa);
2106 if (error == 0)
2107 pr->ndpr_stateflags |= NDPRF_ONLINK;
2108
2109 return (error);
2110 }
2111
2112 static int
nd6_prefix_onlink(struct nd_prefix * pr)2113 nd6_prefix_onlink(struct nd_prefix *pr)
2114 {
2115 struct epoch_tracker et;
2116 struct ifaddr *ifa;
2117 struct ifnet *ifp = pr->ndpr_ifp;
2118 struct nd_prefix *opr;
2119 char ip6buf[INET6_ADDRSTRLEN];
2120 int error;
2121
2122 ND6_ONLINK_LOCK_ASSERT();
2123 ND6_UNLOCK_ASSERT();
2124
2125 if ((pr->ndpr_stateflags & NDPRF_ONLINK) != 0)
2126 return (EEXIST);
2127
2128 /*
2129 * Add the interface route associated with the prefix. Before
2130 * installing the route, check if there's the same prefix on another
2131 * interface, and the prefix has already installed the interface route.
2132 * Although such a configuration is expected to be rare, we explicitly
2133 * allow it.
2134 */
2135 ND6_RLOCK();
2136 LIST_FOREACH(opr, &V_nd_prefix, ndpr_entry) {
2137 if (opr == pr)
2138 continue;
2139
2140 if ((opr->ndpr_stateflags & NDPRF_ONLINK) == 0)
2141 continue;
2142
2143 if (!V_rt_add_addr_allfibs &&
2144 opr->ndpr_ifp->if_fib != pr->ndpr_ifp->if_fib)
2145 continue;
2146
2147 if (opr->ndpr_plen == pr->ndpr_plen &&
2148 in6_are_prefix_equal(&pr->ndpr_prefix.sin6_addr,
2149 &opr->ndpr_prefix.sin6_addr, pr->ndpr_plen)) {
2150 ND6_RUNLOCK();
2151 return (0);
2152 }
2153 }
2154 ND6_RUNLOCK();
2155
2156 /*
2157 * We prefer link-local addresses as the associated interface address.
2158 */
2159 /* search for a link-local addr */
2160 NET_EPOCH_ENTER(et);
2161 ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp,
2162 IN6_IFF_NOTREADY | IN6_IFF_ANYCAST);
2163 if (ifa == NULL) {
2164 /* XXX: freebsd does not have ifa_ifwithaf */
2165 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
2166 if (ifa->ifa_addr->sa_family == AF_INET6) {
2167 ifa_ref(ifa);
2168 break;
2169 }
2170 }
2171 /* should we care about ia6_flags? */
2172 }
2173 if (ifa == NULL) {
2174 /*
2175 * This can still happen, when, for example, we receive an RA
2176 * containing a prefix with the L bit set and the A bit clear,
2177 * after removing all IPv6 addresses on the receiving
2178 * interface. This should, of course, be rare though.
2179 */
2180 nd6log((LOG_NOTICE,
2181 "%s: failed to find any ifaddr to add route for a "
2182 "prefix(%s/%d) on %s\n", __func__,
2183 ip6_sprintf(ip6buf, &pr->ndpr_prefix.sin6_addr),
2184 pr->ndpr_plen, if_name(ifp)));
2185 error = 0;
2186 } else {
2187 error = nd6_prefix_onlink_rtrequest(pr, ifa);
2188 ifa_free(ifa);
2189 }
2190 NET_EPOCH_EXIT(et);
2191
2192 return (error);
2193 }
2194
2195 int
nd6_prefix_offlink(struct nd_prefix * pr)2196 nd6_prefix_offlink(struct nd_prefix *pr)
2197 {
2198 int error = 0;
2199 struct ifnet *ifp = pr->ndpr_ifp;
2200 struct nd_prefix *opr;
2201 char ip6buf[INET6_ADDRSTRLEN];
2202 uint64_t genid;
2203 int a_failure;
2204
2205 ND6_ONLINK_LOCK_ASSERT();
2206 ND6_UNLOCK_ASSERT();
2207
2208 if ((pr->ndpr_stateflags & NDPRF_ONLINK) == 0)
2209 return (EEXIST);
2210
2211 struct sockaddr_in6 mask6 = {
2212 .sin6_family = AF_INET6,
2213 .sin6_len = sizeof(struct sockaddr_in6),
2214 .sin6_addr = pr->ndpr_mask,
2215 };
2216 struct sockaddr_in6 *pmask6 = (pr->ndpr_plen != 128) ? &mask6 : NULL;
2217
2218 error = nd6_prefix_rtrequest(ifp->if_fib, RTM_DELETE,
2219 &pr->ndpr_prefix, pmask6, ifp, NULL);
2220
2221 a_failure = 1;
2222 if (error == 0) {
2223 pr->ndpr_stateflags &= ~NDPRF_ONLINK;
2224
2225 /*
2226 * There might be the same prefix on another interface,
2227 * the prefix which could not be on-link just because we have
2228 * the interface route (see comments in nd6_prefix_onlink).
2229 * If there's one, try to make the prefix on-link on the
2230 * interface.
2231 */
2232 ND6_RLOCK();
2233 restart:
2234 LIST_FOREACH(opr, &V_nd_prefix, ndpr_entry) {
2235 /*
2236 * KAME specific: detached prefixes should not be
2237 * on-link.
2238 */
2239 if (opr == pr || (opr->ndpr_stateflags &
2240 (NDPRF_ONLINK | NDPRF_DETACHED)) != 0)
2241 continue;
2242
2243 if (opr->ndpr_plen == pr->ndpr_plen &&
2244 in6_are_prefix_equal(&pr->ndpr_prefix.sin6_addr,
2245 &opr->ndpr_prefix.sin6_addr, pr->ndpr_plen)) {
2246 int e;
2247
2248 genid = V_nd6_list_genid;
2249 ND6_RUNLOCK();
2250 if ((e = nd6_prefix_onlink(opr)) != 0) {
2251 nd6log((LOG_ERR,
2252 "%s: failed to recover a prefix "
2253 "%s/%d from %s to %s (errno=%d)\n",
2254 __func__, ip6_sprintf(ip6buf,
2255 &opr->ndpr_prefix.sin6_addr),
2256 opr->ndpr_plen, if_name(ifp),
2257 if_name(opr->ndpr_ifp), e));
2258 } else
2259 a_failure = 0;
2260 ND6_RLOCK();
2261 if (genid != V_nd6_list_genid)
2262 goto restart;
2263 }
2264 }
2265 ND6_RUNLOCK();
2266 } else {
2267 /* XXX: can we still set the NDPRF_ONLINK flag? */
2268 nd6log((LOG_ERR,
2269 "%s: failed to delete route: %s/%d on %s (errno=%d)\n",
2270 __func__, ip6_sprintf(ip6buf, &pr->ndpr_prefix.sin6_addr),
2271 pr->ndpr_plen, if_name(ifp), error));
2272 }
2273
2274 if (a_failure)
2275 lltable_prefix_free(AF_INET6,
2276 (struct sockaddr *)&pr->ndpr_prefix,
2277 (struct sockaddr *)&mask6, LLE_STATIC);
2278
2279 return (error);
2280 }
2281
2282 /*
2283 * Get a randomized interface identifier for a temporary address
2284 * Based on RFC 8981, Section 3.3.1.
2285 */
2286 static int
in6_get_tmp_ifid(struct in6_aliasreq * ifra)2287 in6_get_tmp_ifid(struct in6_aliasreq *ifra)
2288 {
2289 struct in6_addr *addr;
2290
2291 if(!is_random_seeded()){
2292 return 1;
2293 }
2294
2295 addr = &(ifra->ifra_addr.sin6_addr);
2296 regen:
2297 ifra->ifra_addr.sin6_addr.s6_addr32[2] |=
2298 (arc4random() & ~(ifra->ifra_prefixmask.sin6_addr.s6_addr32[2]));
2299 ifra->ifra_addr.sin6_addr.s6_addr32[3] |=
2300 (arc4random() & ~(ifra->ifra_prefixmask.sin6_addr.s6_addr32[3]));
2301
2302 /*
2303 * Check if generated address is not inappropriate:
2304 *
2305 * - Reserved IPv6 Interface Identifiers
2306 * (https://www.iana.org/assignments/ipv6-interface-ids/)
2307 */
2308
2309 /* Subnet-router anycast: 0000:0000:0000:0000 */
2310 if (!(addr->s6_addr32[2] | addr->s6_addr32[3]))
2311 goto regen;
2312
2313 /*
2314 * IANA Ethernet block: 0200:5EFF:FE00:0000-0200:5EFF:FE00:5212
2315 * Proxy Mobile IPv6: 0200:5EFF:FE00:5213
2316 * IANA Ethernet block: 0200:5EFF:FE00:5214-0200:5EFF:FEFF:FFFF
2317 */
2318 if (ntohl(addr->s6_addr32[2]) == 0x02005eff &&
2319 (ntohl(addr->s6_addr32[3]) & 0Xff000000) == 0xfe000000)
2320 goto regen;
2321
2322 /* Reserved subnet anycast addresses */
2323 if (ntohl(addr->s6_addr32[2]) == 0xfdffffff &&
2324 ntohl(addr->s6_addr32[3]) >= 0Xffffff80)
2325 goto regen;
2326
2327 return 0;
2328 }
2329
2330 /*
2331 * ia0 - corresponding public address
2332 */
2333 int
in6_tmpifadd(const struct in6_ifaddr * ia0,int forcegen,int delay)2334 in6_tmpifadd(const struct in6_ifaddr *ia0, int forcegen, int delay)
2335 {
2336 struct ifnet *ifp = ia0->ia_ifa.ifa_ifp;
2337 struct in6_ifaddr *newia;
2338 struct in6_aliasreq ifra;
2339 int error;
2340 int trylimit = 3; /* XXX: adhoc value */
2341 int updateflags;
2342 time_t vltime0, pltime0;
2343
2344 in6_prepare_ifra(&ifra, &ia0->ia_addr.sin6_addr,
2345 &ia0->ia_prefixmask.sin6_addr);
2346
2347 ifra.ifra_addr = ia0->ia_addr; /* XXX: do we need this ? */
2348 /* clear the old IFID */
2349 IN6_MASK_ADDR(&ifra.ifra_addr.sin6_addr,
2350 &ifra.ifra_prefixmask.sin6_addr);
2351
2352 again:
2353 if (in6_get_tmp_ifid(&ifra) != 0) {
2354 nd6log((LOG_NOTICE, "%s: failed to find a good random IFID\n",
2355 __func__));
2356 return (EINVAL);
2357 }
2358
2359 /*
2360 * in6_get_tmpifid() quite likely provided a unique interface ID.
2361 * However, we may still have a chance to see collision, because
2362 * there may be a time lag between generation of the ID and generation
2363 * of the address. So, we'll do one more sanity check.
2364 */
2365
2366 if (in6_localip(&ifra.ifra_addr.sin6_addr) != 0) {
2367 if (trylimit-- > 0) {
2368 forcegen = 1;
2369 goto again;
2370 }
2371
2372 /* Give up. Something strange should have happened. */
2373 nd6log((LOG_NOTICE, "%s: failed to find a unique random IFID\n",
2374 __func__));
2375 return (EEXIST);
2376 }
2377
2378 /*
2379 * The Valid Lifetime is the lower of the Valid Lifetime of the
2380 * public address or TEMP_VALID_LIFETIME.
2381 * The Preferred Lifetime is the lower of the Preferred Lifetime
2382 * of the public address or TEMP_PREFERRED_LIFETIME -
2383 * DESYNC_FACTOR.
2384 */
2385 if (ia0->ia6_lifetime.ia6t_vltime != ND6_INFINITE_LIFETIME) {
2386 vltime0 = IFA6_IS_INVALID(ia0) ? 0 :
2387 (ia0->ia6_lifetime.ia6t_vltime -
2388 (time_uptime - ia0->ia6_updatetime));
2389 if (vltime0 > V_ip6_temp_valid_lifetime)
2390 vltime0 = V_ip6_temp_valid_lifetime;
2391 } else
2392 vltime0 = V_ip6_temp_valid_lifetime;
2393 if (ia0->ia6_lifetime.ia6t_pltime != ND6_INFINITE_LIFETIME) {
2394 pltime0 = IFA6_IS_DEPRECATED(ia0) ? 0 :
2395 (ia0->ia6_lifetime.ia6t_pltime -
2396 (time_uptime - ia0->ia6_updatetime));
2397 if (pltime0 > V_ip6_temp_preferred_lifetime - V_ip6_desync_factor){
2398 pltime0 = V_ip6_temp_preferred_lifetime -
2399 V_ip6_desync_factor;
2400 }
2401 } else
2402 pltime0 = V_ip6_temp_preferred_lifetime - V_ip6_desync_factor;
2403 ifra.ifra_lifetime.ia6t_vltime = vltime0;
2404 ifra.ifra_lifetime.ia6t_pltime = pltime0;
2405
2406 /*
2407 * A temporary address is created only if this calculated Preferred
2408 * Lifetime is greater than REGEN_ADVANCE time units.
2409 */
2410 if (ifra.ifra_lifetime.ia6t_pltime <= V_ip6_temp_regen_advance)
2411 return (0);
2412
2413 /* XXX: scope zone ID? */
2414
2415 ifra.ifra_flags |= (IN6_IFF_AUTOCONF|IN6_IFF_TEMPORARY);
2416
2417 /* allocate ifaddr structure, link into chain, etc. */
2418 updateflags = 0;
2419 if (delay)
2420 updateflags |= IN6_IFAUPDATE_DADDELAY;
2421 if ((error = in6_update_ifa(ifp, &ifra, NULL, updateflags)) != 0)
2422 return (error);
2423
2424 newia = in6ifa_ifpwithaddr(ifp, &ifra.ifra_addr.sin6_addr);
2425 if (newia == NULL) { /* XXX: can it happen? */
2426 nd6log((LOG_ERR,
2427 "%s: ifa update succeeded, but we got no ifaddr\n",
2428 __func__));
2429 return (EINVAL); /* XXX */
2430 }
2431 newia->ia6_ndpr = ia0->ia6_ndpr;
2432 newia->ia6_ndpr->ndpr_addrcnt++;
2433 ifa_free(&newia->ia_ifa);
2434
2435 /*
2436 * A newly added address might affect the status of other addresses.
2437 * XXX: when the temporary address is generated with a new public
2438 * address, the onlink check is redundant. However, it would be safe
2439 * to do the check explicitly everywhere a new address is generated,
2440 * and, in fact, we surely need the check when we create a new
2441 * temporary address due to deprecation of an old temporary address.
2442 */
2443 pfxlist_onlink_check();
2444
2445 return (0);
2446 }
2447
2448 static int
rt6_deleteroute(const struct rtentry * rt,const struct nhop_object * nh,void * arg)2449 rt6_deleteroute(const struct rtentry *rt, const struct nhop_object *nh,
2450 void *arg)
2451 {
2452 struct in6_addr *gate = (struct in6_addr *)arg;
2453 int nh_rt_flags;
2454
2455 if (nh->gw_sa.sa_family != AF_INET6)
2456 return (0);
2457
2458 if (!IN6_ARE_ADDR_EQUAL(gate, &nh->gw6_sa.sin6_addr)) {
2459 return (0);
2460 }
2461
2462 /*
2463 * Do not delete a static route.
2464 * XXX: this seems to be a bit ad-hoc. Should we consider the
2465 * 'cloned' bit instead?
2466 */
2467 nh_rt_flags = nhop_get_rtflags(nh);
2468 if ((nh_rt_flags & RTF_STATIC) != 0)
2469 return (0);
2470
2471 /*
2472 * We delete only host route. This means, in particular, we don't
2473 * delete default route.
2474 */
2475 if ((nh_rt_flags & RTF_HOST) == 0)
2476 return (0);
2477
2478 return (1);
2479 #undef SIN6
2480 }
2481
2482 /*
2483 * Delete all the routing table entries that use the specified gateway.
2484 * XXX: this function causes search through all entries of routing table, so
2485 * it shouldn't be called when acting as a router.
2486 */
2487 void
rt6_flush(struct in6_addr * gateway,struct ifnet * ifp)2488 rt6_flush(struct in6_addr *gateway, struct ifnet *ifp)
2489 {
2490
2491 /* We'll care only link-local addresses */
2492 if (!IN6_IS_ADDR_LINKLOCAL(gateway))
2493 return;
2494
2495 /* XXX Do we really need to walk any but the default FIB? */
2496 rib_foreach_table_walk_del(AF_INET6, rt6_deleteroute, (void *)gateway);
2497 }
2498
2499 int
nd6_setdefaultiface(int ifindex)2500 nd6_setdefaultiface(int ifindex)
2501 {
2502
2503 if (V_nd6_defifindex != ifindex) {
2504 V_nd6_defifindex = ifindex;
2505 if (V_nd6_defifindex != 0) {
2506 struct epoch_tracker et;
2507
2508 /*
2509 * XXXGL: this function should use ifnet_byindex_ref!
2510 */
2511 NET_EPOCH_ENTER(et);
2512 V_nd6_defifp = ifnet_byindex(V_nd6_defifindex);
2513 NET_EPOCH_EXIT(et);
2514 if (V_nd6_defifp == NULL)
2515 return (EINVAL);
2516 } else
2517 V_nd6_defifp = NULL;
2518
2519 /*
2520 * Our current implementation assumes one-to-one mapping between
2521 * interfaces and links, so it would be natural to use the
2522 * default interface as the default link.
2523 */
2524 scope6_setdefault(V_nd6_defifp);
2525 }
2526
2527 return (0);
2528 }
2529
2530 bool
nd6_defrouter_list_empty(void)2531 nd6_defrouter_list_empty(void)
2532 {
2533
2534 return (TAILQ_EMPTY(&V_nd6_defrouter));
2535 }
2536
2537 void
nd6_defrouter_timer(void)2538 nd6_defrouter_timer(void)
2539 {
2540 struct nd_defrouter *dr, *ndr;
2541 struct nd6_drhead drq;
2542
2543 TAILQ_INIT(&drq);
2544
2545 ND6_WLOCK();
2546 TAILQ_FOREACH_SAFE(dr, &V_nd6_defrouter, dr_entry, ndr)
2547 if (dr->expire && dr->expire < time_uptime)
2548 defrouter_unlink(dr, &drq);
2549 ND6_WUNLOCK();
2550
2551 while ((dr = TAILQ_FIRST(&drq)) != NULL) {
2552 TAILQ_REMOVE(&drq, dr, dr_entry);
2553 defrouter_del(dr);
2554 }
2555 }
2556
2557 /*
2558 * Nuke default router list entries toward ifp.
2559 * We defer removal of default router list entries that is installed in the
2560 * routing table, in order to keep additional side effects as small as possible.
2561 */
2562 void
nd6_defrouter_purge(struct ifnet * ifp)2563 nd6_defrouter_purge(struct ifnet *ifp)
2564 {
2565 struct nd_defrouter *dr, *ndr;
2566 struct nd6_drhead drq;
2567
2568 TAILQ_INIT(&drq);
2569
2570 ND6_WLOCK();
2571 TAILQ_FOREACH_SAFE(dr, &V_nd6_defrouter, dr_entry, ndr) {
2572 if (dr->installed)
2573 continue;
2574 if (dr->ifp == ifp)
2575 defrouter_unlink(dr, &drq);
2576 }
2577 TAILQ_FOREACH_SAFE(dr, &V_nd6_defrouter, dr_entry, ndr) {
2578 if (!dr->installed)
2579 continue;
2580 if (dr->ifp == ifp)
2581 defrouter_unlink(dr, &drq);
2582 }
2583 ND6_WUNLOCK();
2584
2585 /* Delete the unlinked router objects. */
2586 while ((dr = TAILQ_FIRST(&drq)) != NULL) {
2587 TAILQ_REMOVE(&drq, dr, dr_entry);
2588 defrouter_del(dr);
2589 }
2590 }
2591
2592 void
nd6_defrouter_flush_all(void)2593 nd6_defrouter_flush_all(void)
2594 {
2595 struct nd_defrouter *dr;
2596 struct nd6_drhead drq;
2597
2598 TAILQ_INIT(&drq);
2599
2600 ND6_WLOCK();
2601 while ((dr = TAILQ_FIRST(&V_nd6_defrouter)) != NULL)
2602 defrouter_unlink(dr, &drq);
2603 ND6_WUNLOCK();
2604
2605 while ((dr = TAILQ_FIRST(&drq)) != NULL) {
2606 TAILQ_REMOVE(&drq, dr, dr_entry);
2607 defrouter_del(dr);
2608 }
2609 }
2610
2611 void
nd6_defrouter_init(void)2612 nd6_defrouter_init(void)
2613 {
2614
2615 TAILQ_INIT(&V_nd6_defrouter);
2616 }
2617
2618 static int
nd6_sysctl_drlist(SYSCTL_HANDLER_ARGS)2619 nd6_sysctl_drlist(SYSCTL_HANDLER_ARGS)
2620 {
2621 struct in6_defrouter d;
2622 struct nd_defrouter *dr;
2623 int error;
2624
2625 if (req->newptr != NULL)
2626 return (EPERM);
2627
2628 error = sysctl_wire_old_buffer(req, 0);
2629 if (error != 0)
2630 return (error);
2631
2632 bzero(&d, sizeof(d));
2633 d.rtaddr.sin6_family = AF_INET6;
2634 d.rtaddr.sin6_len = sizeof(d.rtaddr);
2635
2636 ND6_RLOCK();
2637 TAILQ_FOREACH(dr, &V_nd6_defrouter, dr_entry) {
2638 d.rtaddr.sin6_addr = dr->rtaddr;
2639 error = sa6_recoverscope(&d.rtaddr);
2640 if (error != 0)
2641 break;
2642 d.flags = dr->raflags;
2643 d.rtlifetime = dr->rtlifetime;
2644 d.expire = dr->expire + (time_second - time_uptime);
2645 d.if_index = dr->ifp->if_index;
2646 error = SYSCTL_OUT(req, &d, sizeof(d));
2647 if (error != 0)
2648 break;
2649 }
2650 ND6_RUNLOCK();
2651 return (error);
2652 }
2653 SYSCTL_PROC(_net_inet6_icmp6, ICMPV6CTL_ND6_DRLIST, nd6_drlist,
2654 CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE,
2655 NULL, 0, nd6_sysctl_drlist, "S,in6_defrouter",
2656 "NDP default router list");
2657