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 static struct nd_defrouter *defrtrlist_update(struct nd_defrouter *);
79 static int prelist_update(struct nd_prefixctl *, struct nd_defrouter *,
80 struct mbuf *, int);
81 static int nd6_prefix_onlink(struct nd_prefix *);
82 static int in6_get_tmp_ifid(struct in6_aliasreq *);
83
84 TAILQ_HEAD(nd6_drhead, nd_defrouter);
85 VNET_DEFINE_STATIC(struct nd6_drhead, nd6_defrouter);
86 #define V_nd6_defrouter VNET(nd6_defrouter)
87
88 VNET_DECLARE(int, nd6_recalc_reachtm_interval);
89 #define V_nd6_recalc_reachtm_interval VNET(nd6_recalc_reachtm_interval)
90
91 VNET_DEFINE_STATIC(struct ifnet *, nd6_defifp);
92 VNET_DEFINE(int, nd6_defifindex);
93 #define V_nd6_defifp VNET(nd6_defifp)
94
95 VNET_DEFINE(int, ip6_use_tempaddr) = 0;
96 VNET_DEFINE(bool, ip6_use_stableaddr) = 0;
97
98 VNET_DEFINE(int, ip6_desync_factor);
99 VNET_DEFINE(uint32_t, ip6_temp_max_desync_factor) = TEMP_MAX_DESYNC_FACTOR_BASE;
100 VNET_DEFINE(u_int32_t, ip6_temp_preferred_lifetime) = DEF_TEMP_PREFERRED_LIFETIME;
101 VNET_DEFINE(u_int32_t, ip6_temp_valid_lifetime) = DEF_TEMP_VALID_LIFETIME;
102
103 VNET_DEFINE(int, ip6_temp_regen_advance) = TEMPADDR_REGEN_ADVANCE;
104
105 #ifdef EXPERIMENTAL
106 VNET_DEFINE_STATIC(int, nd6_ignore_ipv6_only_ra) = 1;
107 #define V_nd6_ignore_ipv6_only_ra VNET(nd6_ignore_ipv6_only_ra)
108 SYSCTL_INT(_net_inet6_icmp6, OID_AUTO,
109 nd6_ignore_ipv6_only_ra, CTLFLAG_VNET | CTLFLAG_RW,
110 &VNET_NAME(nd6_ignore_ipv6_only_ra), 0,
111 "Ignore the 'IPv6-Only flag' in RA messages in compliance with "
112 "draft-ietf-6man-ipv6only-flag");
113 #endif
114
115 /* RTPREF_MEDIUM has to be 0! */
116 #define RTPREF_HIGH 1
117 #define RTPREF_MEDIUM 0
118 #define RTPREF_LOW (-1)
119 #define RTPREF_RESERVED (-2)
120 #define RTPREF_INVALID (-3) /* internal */
121
122 static void
defrouter_ref(struct nd_defrouter * dr)123 defrouter_ref(struct nd_defrouter *dr)
124 {
125
126 refcount_acquire(&dr->refcnt);
127 }
128
129 void
defrouter_rele(struct nd_defrouter * dr)130 defrouter_rele(struct nd_defrouter *dr)
131 {
132
133 if (refcount_release(&dr->refcnt))
134 free(dr, M_IP6NDP);
135 }
136
137 /*
138 * Remove a router from the global list and optionally stash it in a
139 * caller-supplied queue.
140 */
141 static void
defrouter_unlink(struct nd_defrouter * dr,struct nd6_drhead * drq)142 defrouter_unlink(struct nd_defrouter *dr, struct nd6_drhead *drq)
143 {
144
145 ND6_WLOCK_ASSERT();
146
147 TAILQ_REMOVE(&V_nd6_defrouter, dr, dr_entry);
148 V_nd6_list_genid++;
149 if (drq != NULL)
150 TAILQ_INSERT_TAIL(drq, dr, dr_entry);
151 }
152
153 /*
154 * Receive Router Solicitation Message - just for routers.
155 * Router solicitation/advertisement is mostly managed by userland program
156 * (rtadvd) so here we have no function like nd6_ra_output().
157 *
158 * Based on RFC 2461
159 */
160 void
nd6_rs_input(struct mbuf * m,int off,int icmp6len)161 nd6_rs_input(struct mbuf *m, int off, int icmp6len)
162 {
163 struct ifnet *ifp;
164 struct ip6_hdr *ip6;
165 struct nd_router_solicit *nd_rs;
166 struct in6_addr saddr6;
167 union nd_opts ndopts;
168 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
169 char *lladdr;
170 int lladdrlen;
171
172 ifp = m->m_pkthdr.rcvif;
173
174 /*
175 * Accept RS only when V_ip6_forwarding=1 and the interface has
176 * no ND6_IFF_ACCEPT_RTADV.
177 */
178 if (!V_ip6_forwarding || ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV)
179 goto freeit;
180
181 /* RFC 6980: Nodes MUST silently ignore fragments */
182 if(m->m_flags & M_FRAGMENTED)
183 goto freeit;
184
185 /* Sanity checks */
186 ip6 = mtod(m, struct ip6_hdr *);
187 if (__predict_false(ip6->ip6_hlim != 255)) {
188 ICMP6STAT_INC(icp6s_invlhlim);
189 nd6log((LOG_ERR,
190 "%s: invalid hlim (%d) from %s to %s on %s\n", __func__,
191 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src),
192 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp)));
193 goto bad;
194 }
195
196 /*
197 * Don't update the neighbor cache, if src = ::.
198 * This indicates that the src has no IP address assigned yet.
199 */
200 saddr6 = ip6->ip6_src;
201 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6))
202 goto freeit;
203
204 if (m->m_len < off + icmp6len) {
205 m = m_pullup(m, off + icmp6len);
206 if (m == NULL) {
207 IP6STAT_INC(ip6s_exthdrtoolong);
208 return;
209 }
210 }
211 ip6 = mtod(m, struct ip6_hdr *);
212 nd_rs = (struct nd_router_solicit *)((caddr_t)ip6 + off);
213
214 icmp6len -= sizeof(*nd_rs);
215 nd6_option_init(nd_rs + 1, icmp6len, &ndopts);
216 if (nd6_options(&ndopts) < 0) {
217 nd6log((LOG_INFO,
218 "%s: invalid ND option, ignored\n", __func__));
219 /* nd6_options have incremented stats */
220 goto freeit;
221 }
222
223 lladdr = NULL;
224 lladdrlen = 0;
225 if (ndopts.nd_opts_src_lladdr) {
226 lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1);
227 lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3;
228 }
229
230 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
231 nd6log((LOG_INFO,
232 "%s: lladdrlen mismatch for %s (if %d, RS packet %d)\n",
233 __func__, ip6_sprintf(ip6bufs, &saddr6),
234 ifp->if_addrlen, lladdrlen - 2));
235 goto bad;
236 }
237
238 nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, ND_ROUTER_SOLICIT, 0);
239
240 freeit:
241 m_freem(m);
242 return;
243
244 bad:
245 ICMP6STAT_INC(icp6s_badrs);
246 m_freem(m);
247 }
248
249 #ifdef EXPERIMENTAL
250 /*
251 * An initial update routine for draft-ietf-6man-ipv6only-flag.
252 * We need to iterate over all default routers for the given
253 * interface to see whether they are all advertising the "S"
254 * (IPv6-Only) flag. If they do set, otherwise unset, the
255 * interface flag we later use to filter on.
256 *
257 * XXXGL: The use of IF_ADDR_WLOCK (previously it was IF_AFDATA_LOCK) in this
258 * function is quite strange.
259 */
260 static void
defrtr_ipv6_only_ifp(struct ifnet * ifp)261 defrtr_ipv6_only_ifp(struct ifnet *ifp)
262 {
263 struct nd_defrouter *dr;
264 bool ipv6_only, ipv6_only_old;
265 #ifdef INET
266 struct epoch_tracker et;
267 struct ifaddr *ifa;
268 bool has_ipv4_addr;
269 #endif
270
271 if (V_nd6_ignore_ipv6_only_ra != 0)
272 return;
273
274 ipv6_only = true;
275 ND6_RLOCK();
276 TAILQ_FOREACH(dr, &V_nd6_defrouter, dr_entry)
277 if (dr->ifp == ifp &&
278 (dr->raflags & ND_RA_FLAG_IPV6_ONLY) == 0)
279 ipv6_only = false;
280 ND6_RUNLOCK();
281
282 IF_ADDR_WLOCK(ifp);
283 ipv6_only_old = ND_IFINFO(ifp)->flags & ND6_IFF_IPV6_ONLY;
284 IF_ADDR_WUNLOCK(ifp);
285
286 /* If nothing changed, we have an early exit. */
287 if (ipv6_only == ipv6_only_old)
288 return;
289
290 #ifdef INET
291 /*
292 * Should we want to set the IPV6-ONLY flag, check if the
293 * interface has a non-0/0 and non-link-local IPv4 address
294 * configured on it. If it has we will assume working
295 * IPv4 operations and will clear the interface flag.
296 */
297 has_ipv4_addr = false;
298 if (ipv6_only) {
299 NET_EPOCH_ENTER(et);
300 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
301 if (ifa->ifa_addr->sa_family != AF_INET)
302 continue;
303 if (in_canforward(
304 satosin(ifa->ifa_addr)->sin_addr)) {
305 has_ipv4_addr = true;
306 break;
307 }
308 }
309 NET_EPOCH_EXIT(et);
310 }
311 if (ipv6_only && has_ipv4_addr) {
312 log(LOG_NOTICE, "%s rcvd RA w/ IPv6-Only flag set but has IPv4 "
313 "configured, ignoring IPv6-Only flag.\n", ifp->if_xname);
314 ipv6_only = false;
315 }
316 #endif
317
318 IF_ADDR_WLOCK(ifp);
319 if (ipv6_only)
320 ND_IFINFO(ifp)->flags |= ND6_IFF_IPV6_ONLY;
321 else
322 ND_IFINFO(ifp)->flags &= ~ND6_IFF_IPV6_ONLY;
323 IF_ADDR_WUNLOCK(ifp);
324
325 #ifdef notyet
326 /* Send notification of flag change. */
327 #endif
328 }
329
330 static void
defrtr_ipv6_only_ipf_down(struct ifnet * ifp)331 defrtr_ipv6_only_ipf_down(struct ifnet *ifp)
332 {
333
334 IF_ADDR_WLOCK(ifp);
335 ND_IFINFO(ifp)->flags &= ~ND6_IFF_IPV6_ONLY;
336 IF_ADDR_WUNLOCK(ifp);
337 }
338 #endif /* EXPERIMENTAL */
339
340 void
nd6_ifnet_link_event(void * arg __unused,struct ifnet * ifp,int linkstate)341 nd6_ifnet_link_event(void *arg __unused, struct ifnet *ifp, int linkstate)
342 {
343
344 /*
345 * XXX-BZ we might want to trigger re-evaluation of our default router
346 * availability. E.g., on link down the default router might be
347 * unreachable but a different interface might still have connectivity.
348 */
349
350 #ifdef EXPERIMENTAL
351 if (linkstate == LINK_STATE_DOWN)
352 defrtr_ipv6_only_ipf_down(ifp);
353 #endif
354 }
355
356 /*
357 * Receive Router Advertisement Message.
358 *
359 * Based on RFC 2461
360 * TODO: on-link bit on prefix information
361 * TODO: ND_RA_FLAG_{OTHER,MANAGED} processing
362 */
363 void
nd6_ra_input(struct mbuf * m,int off,int icmp6len)364 nd6_ra_input(struct mbuf *m, int off, int icmp6len)
365 {
366 struct ifnet *ifp;
367 struct nd_ifinfo *ndi;
368 struct ip6_hdr *ip6;
369 struct nd_router_advert *nd_ra;
370 struct in6_addr saddr6;
371 struct nd_defrouter *dr;
372 union nd_opts ndopts;
373 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
374 int mcast;
375
376 /*
377 * We only accept RAs only when the per-interface flag
378 * ND6_IFF_ACCEPT_RTADV is on the receiving interface.
379 */
380 ifp = m->m_pkthdr.rcvif;
381 ndi = ND_IFINFO(ifp);
382 if (!(ndi->flags & ND6_IFF_ACCEPT_RTADV))
383 goto freeit;
384
385 /* RFC 6980: Nodes MUST silently ignore fragments */
386 if(m->m_flags & M_FRAGMENTED)
387 goto freeit;
388
389 ip6 = mtod(m, struct ip6_hdr *);
390 if (__predict_false(ip6->ip6_hlim != 255)) {
391 ICMP6STAT_INC(icp6s_invlhlim);
392 nd6log((LOG_ERR,
393 "%s: invalid hlim (%d) from %s to %s on %s\n", __func__,
394 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src),
395 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp)));
396 goto bad;
397 }
398
399 saddr6 = ip6->ip6_src;
400 if (!IN6_IS_ADDR_LINKLOCAL(&saddr6)) {
401 nd6log((LOG_ERR,
402 "%s: src %s is not link-local\n", __func__,
403 ip6_sprintf(ip6bufs, &saddr6)));
404 goto bad;
405 }
406
407 if (m->m_len < off + icmp6len) {
408 m = m_pullup(m, off + icmp6len);
409 if (m == NULL) {
410 IP6STAT_INC(ip6s_exthdrtoolong);
411 return;
412 }
413 }
414 ip6 = mtod(m, struct ip6_hdr *);
415 nd_ra = (struct nd_router_advert *)((caddr_t)ip6 + off);
416
417 icmp6len -= sizeof(*nd_ra);
418 nd6_option_init(nd_ra + 1, icmp6len, &ndopts);
419 if (nd6_options(&ndopts) < 0) {
420 nd6log((LOG_INFO,
421 "%s: invalid ND option, ignored\n", __func__));
422 /* nd6_options have incremented stats */
423 goto freeit;
424 }
425
426 mcast = 0;
427 dr = NULL;
428 {
429 struct nd_defrouter dr0;
430 u_int32_t advreachable = nd_ra->nd_ra_reachable;
431
432 /* remember if this is a multicasted advertisement */
433 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst))
434 mcast = 1;
435
436 bzero(&dr0, sizeof(dr0));
437 dr0.rtaddr = saddr6;
438 dr0.raflags = nd_ra->nd_ra_flags_reserved;
439 /*
440 * Effectively-disable routes from RA messages when
441 * ND6_IFF_NO_RADR enabled on the receiving interface or
442 * (ip6.forwarding == 1 && ip6.rfc6204w3 != 1).
443 */
444 if (ndi->flags & ND6_IFF_NO_RADR)
445 dr0.rtlifetime = 0;
446 else if (V_ip6_forwarding && !V_ip6_rfc6204w3)
447 dr0.rtlifetime = 0;
448 else
449 dr0.rtlifetime = ntohs(nd_ra->nd_ra_router_lifetime);
450 dr0.expire = time_uptime + dr0.rtlifetime;
451 dr0.ifp = ifp;
452 /* unspecified or not? (RFC 2461 6.3.4) */
453 if (advreachable) {
454 advreachable = ntohl(advreachable);
455 if (advreachable <= MAX_REACHABLE_TIME &&
456 ndi->basereachable != advreachable) {
457 ndi->basereachable = advreachable;
458 ndi->reachable = ND_COMPUTE_RTIME(ndi->basereachable);
459 ndi->recalctm = V_nd6_recalc_reachtm_interval; /* reset */
460 }
461 }
462 if (nd_ra->nd_ra_retransmit)
463 ndi->retrans = ntohl(nd_ra->nd_ra_retransmit);
464 if (nd_ra->nd_ra_curhoplimit) {
465 if (ndi->chlim < nd_ra->nd_ra_curhoplimit)
466 ndi->chlim = nd_ra->nd_ra_curhoplimit;
467 else if (ndi->chlim != nd_ra->nd_ra_curhoplimit) {
468 log(LOG_ERR, "RA with a lower CurHopLimit sent from "
469 "%s on %s (current = %d, received = %d). "
470 "Ignored.\n", ip6_sprintf(ip6bufs, &ip6->ip6_src),
471 if_name(ifp), ndi->chlim, nd_ra->nd_ra_curhoplimit);
472 }
473 }
474 dr = defrtrlist_update(&dr0);
475 #ifdef EXPERIMENTAL
476 defrtr_ipv6_only_ifp(ifp);
477 #endif
478 }
479
480 /*
481 * prefix
482 */
483 if (ndopts.nd_opts_pi) {
484 struct nd_opt_hdr *pt;
485 struct nd_opt_prefix_info *pi = NULL;
486 struct nd_prefixctl pr;
487
488 for (pt = (struct nd_opt_hdr *)ndopts.nd_opts_pi;
489 pt <= (struct nd_opt_hdr *)ndopts.nd_opts_pi_end;
490 pt = (struct nd_opt_hdr *)((caddr_t)pt +
491 (pt->nd_opt_len << 3))) {
492 if (pt->nd_opt_type != ND_OPT_PREFIX_INFORMATION)
493 continue;
494 pi = (struct nd_opt_prefix_info *)pt;
495
496 if (pi->nd_opt_pi_len != 4) {
497 nd6log((LOG_INFO,
498 "%s: invalid option len %d for prefix "
499 "information option, ignored\n", __func__,
500 pi->nd_opt_pi_len));
501 continue;
502 }
503
504 if (128 < pi->nd_opt_pi_prefix_len) {
505 nd6log((LOG_INFO,
506 "%s: invalid prefix len %d for prefix "
507 "information option, ignored\n", __func__,
508 pi->nd_opt_pi_prefix_len));
509 continue;
510 }
511
512 if (IN6_IS_ADDR_MULTICAST(&pi->nd_opt_pi_prefix)
513 || IN6_IS_ADDR_LINKLOCAL(&pi->nd_opt_pi_prefix)) {
514 nd6log((LOG_INFO,
515 "%s: invalid prefix %s, ignored\n",
516 __func__, ip6_sprintf(ip6bufs,
517 &pi->nd_opt_pi_prefix)));
518 continue;
519 }
520
521 bzero(&pr, sizeof(pr));
522 pr.ndpr_prefix.sin6_family = AF_INET6;
523 pr.ndpr_prefix.sin6_len = sizeof(pr.ndpr_prefix);
524 pr.ndpr_prefix.sin6_addr = pi->nd_opt_pi_prefix;
525 pr.ndpr_ifp = (struct ifnet *)m->m_pkthdr.rcvif;
526
527 pr.ndpr_raf_onlink = (pi->nd_opt_pi_flags_reserved &
528 ND_OPT_PI_FLAG_ONLINK) ? 1 : 0;
529 pr.ndpr_raf_auto = (pi->nd_opt_pi_flags_reserved &
530 ND_OPT_PI_FLAG_AUTO) ? 1 : 0;
531 pr.ndpr_plen = pi->nd_opt_pi_prefix_len;
532 pr.ndpr_vltime = ntohl(pi->nd_opt_pi_valid_time);
533 pr.ndpr_pltime = ntohl(pi->nd_opt_pi_preferred_time);
534 (void)prelist_update(&pr, dr, m, mcast);
535 }
536 }
537 if (dr != NULL) {
538 defrouter_rele(dr);
539 dr = NULL;
540 }
541
542 /*
543 * MTU
544 */
545 if (ndopts.nd_opts_mtu && ndopts.nd_opts_mtu->nd_opt_mtu_len == 1) {
546 u_long mtu;
547 u_long maxmtu;
548
549 mtu = (u_long)ntohl(ndopts.nd_opts_mtu->nd_opt_mtu_mtu);
550
551 /* lower bound */
552 if (mtu < IPV6_MMTU) {
553 nd6log((LOG_INFO, "%s: bogus mtu option mtu=%lu sent "
554 "from %s, ignoring\n", __func__,
555 mtu, ip6_sprintf(ip6bufs, &ip6->ip6_src)));
556 goto skip;
557 }
558
559 /* upper bound */
560 maxmtu = (ndi->maxmtu && ndi->maxmtu < ifp->if_mtu)
561 ? ndi->maxmtu : ifp->if_mtu;
562 if (mtu <= maxmtu) {
563 if (ndi->linkmtu != mtu) {
564 ndi->linkmtu = mtu;
565 rt_updatemtu(ifp);
566 }
567 } else {
568 nd6log((LOG_INFO, "%s: bogus mtu=%lu sent from %s; "
569 "exceeds maxmtu %lu, ignoring\n", __func__,
570 mtu, ip6_sprintf(ip6bufs, &ip6->ip6_src), maxmtu));
571 }
572 }
573
574 skip:
575
576 /*
577 * Source link layer address
578 */
579 {
580 char *lladdr = NULL;
581 int lladdrlen = 0;
582
583 if (ndopts.nd_opts_src_lladdr) {
584 lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1);
585 lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3;
586 }
587
588 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
589 nd6log((LOG_INFO,
590 "%s: lladdrlen mismatch for %s (if %d, RA packet %d)\n",
591 __func__, ip6_sprintf(ip6bufs, &saddr6),
592 ifp->if_addrlen, lladdrlen - 2));
593 goto bad;
594 }
595
596 nd6_cache_lladdr(ifp, &saddr6, lladdr,
597 lladdrlen, ND_ROUTER_ADVERT, 0);
598
599 /*
600 * Installing a link-layer address might change the state of the
601 * router's neighbor cache, which might also affect our on-link
602 * detection of adveritsed prefixes.
603 */
604 pfxlist_onlink_check();
605 }
606
607 freeit:
608 m_freem(m);
609 return;
610
611 bad:
612 ICMP6STAT_INC(icp6s_badra);
613 m_freem(m);
614 }
615
616 /* PFXRTR */
617 static struct nd_pfxrouter *
pfxrtr_lookup(struct nd_prefix * pr,struct nd_defrouter * dr)618 pfxrtr_lookup(struct nd_prefix *pr, struct nd_defrouter *dr)
619 {
620 struct nd_pfxrouter *search;
621
622 ND6_LOCK_ASSERT();
623
624 LIST_FOREACH(search, &pr->ndpr_advrtrs, pfr_entry) {
625 if (search->router == dr)
626 break;
627 }
628 return (search);
629 }
630
631 static void
pfxrtr_add(struct nd_prefix * pr,struct nd_defrouter * dr)632 pfxrtr_add(struct nd_prefix *pr, struct nd_defrouter *dr)
633 {
634 struct nd_pfxrouter *new;
635 bool update;
636
637 ND6_UNLOCK_ASSERT();
638
639 ND6_RLOCK();
640 if (pfxrtr_lookup(pr, dr) != NULL) {
641 ND6_RUNLOCK();
642 return;
643 }
644 ND6_RUNLOCK();
645
646 new = malloc(sizeof(*new), M_IP6NDP, M_NOWAIT | M_ZERO);
647 if (new == NULL)
648 return;
649 defrouter_ref(dr);
650 new->router = dr;
651
652 ND6_WLOCK();
653 if (pfxrtr_lookup(pr, dr) == NULL) {
654 LIST_INSERT_HEAD(&pr->ndpr_advrtrs, new, pfr_entry);
655 update = true;
656 } else {
657 /* We lost a race to add the reference. */
658 defrouter_rele(dr);
659 free(new, M_IP6NDP);
660 update = false;
661 }
662 ND6_WUNLOCK();
663
664 if (update)
665 pfxlist_onlink_check();
666 }
667
668 static void
pfxrtr_del(struct nd_pfxrouter * pfr)669 pfxrtr_del(struct nd_pfxrouter *pfr)
670 {
671
672 ND6_WLOCK_ASSERT();
673
674 LIST_REMOVE(pfr, pfr_entry);
675 defrouter_rele(pfr->router);
676 free(pfr, M_IP6NDP);
677 }
678
679 /* Default router list processing sub routines. */
680 static void
defrouter_addreq(struct nd_defrouter * new)681 defrouter_addreq(struct nd_defrouter *new)
682 {
683 uint32_t fibnum = new->ifp->if_fib;
684 struct rib_cmd_info rc = {};
685 int error = 0;
686
687 NET_EPOCH_ASSERT();
688
689 struct sockaddr_in6 gw = {
690 .sin6_family = AF_INET6,
691 .sin6_len = sizeof(struct sockaddr_in6),
692 .sin6_addr = new->rtaddr,
693 };
694
695 error = rib_add_default_route(fibnum, AF_INET6, new->ifp,
696 (struct sockaddr *)&gw, &rc);
697
698 if (error == 0) {
699 struct nhop_object *nh = nhop_select_func(rc.rc_nh_new, 0);
700 rt_routemsg(RTM_ADD, rc.rc_rt, nh, fibnum);
701 new->installed = 1;
702 }
703 }
704
705 /*
706 * Remove the default route for a given router.
707 * This is just a subroutine function for defrouter_select_fib(), and
708 * should not be called from anywhere else.
709 */
710 static void
defrouter_delreq(struct nd_defrouter * dr)711 defrouter_delreq(struct nd_defrouter *dr)
712 {
713 uint32_t fibnum = dr->ifp->if_fib;
714 struct epoch_tracker et;
715 struct rib_cmd_info rc;
716 int error;
717
718 struct sockaddr_in6 dst = {
719 .sin6_family = AF_INET6,
720 .sin6_len = sizeof(struct sockaddr_in6),
721 };
722
723 struct sockaddr_in6 gw = {
724 .sin6_family = AF_INET6,
725 .sin6_len = sizeof(struct sockaddr_in6),
726 .sin6_addr = dr->rtaddr,
727 };
728
729 NET_EPOCH_ENTER(et);
730 error = rib_del_route_px(fibnum, (struct sockaddr *)&dst, 0,
731 rib_match_gw, (struct sockaddr *)&gw, 0, &rc);
732 if (error == 0) {
733 struct nhop_object *nh = nhop_select_func(rc.rc_nh_old, 0);
734 rt_routemsg(RTM_DELETE, rc.rc_rt, nh, fibnum);
735 }
736 NET_EPOCH_EXIT(et);
737
738 dr->installed = 0;
739 }
740
741 static void
defrouter_del(struct nd_defrouter * dr)742 defrouter_del(struct nd_defrouter *dr)
743 {
744 struct nd_defrouter *deldr = NULL;
745 struct nd_prefix *pr;
746 struct nd_pfxrouter *pfxrtr;
747
748 ND6_UNLOCK_ASSERT();
749
750 /*
751 * Flush all the routing table entries that use the router
752 * as a next hop.
753 */
754 if (ND_IFINFO(dr->ifp)->flags & ND6_IFF_ACCEPT_RTADV)
755 rt6_flush(&dr->rtaddr, dr->ifp);
756
757 #ifdef EXPERIMENTAL
758 defrtr_ipv6_only_ifp(dr->ifp);
759 #endif
760
761 if (dr->installed) {
762 deldr = dr;
763 defrouter_delreq(dr);
764 }
765
766 /*
767 * Also delete all the pointers to the router in each prefix lists.
768 */
769 ND6_WLOCK();
770 LIST_FOREACH(pr, &V_nd_prefix, ndpr_entry) {
771 if ((pfxrtr = pfxrtr_lookup(pr, dr)) != NULL)
772 pfxrtr_del(pfxrtr);
773 }
774 ND6_WUNLOCK();
775
776 pfxlist_onlink_check();
777
778 /*
779 * If the router is the primary one, choose a new one.
780 * Note that defrouter_select_fib() will remove the current
781 * gateway from the routing table.
782 */
783 if (deldr)
784 defrouter_select_fib(deldr->ifp->if_fib);
785
786 /*
787 * Release the list reference.
788 */
789 defrouter_rele(dr);
790 }
791
792 struct nd_defrouter *
defrouter_lookup_locked(const struct in6_addr * addr,struct ifnet * ifp)793 defrouter_lookup_locked(const struct in6_addr *addr, struct ifnet *ifp)
794 {
795 struct nd_defrouter *dr;
796
797 ND6_LOCK_ASSERT();
798 TAILQ_FOREACH(dr, &V_nd6_defrouter, dr_entry)
799 if (dr->ifp == ifp && IN6_ARE_ADDR_EQUAL(addr, &dr->rtaddr)) {
800 defrouter_ref(dr);
801 return (dr);
802 }
803 return (NULL);
804 }
805
806 struct nd_defrouter *
defrouter_lookup(const struct in6_addr * addr,struct ifnet * ifp)807 defrouter_lookup(const struct in6_addr *addr, struct ifnet *ifp)
808 {
809 struct nd_defrouter *dr;
810
811 ND6_RLOCK();
812 dr = defrouter_lookup_locked(addr, ifp);
813 ND6_RUNLOCK();
814 return (dr);
815 }
816
817 /*
818 * Remove all default routes from default router list.
819 */
820 void
defrouter_reset(void)821 defrouter_reset(void)
822 {
823 struct nd_defrouter *dr, **dra;
824 int count, i;
825
826 count = i = 0;
827
828 /*
829 * We can't delete routes with the ND lock held, so make a copy of the
830 * current default router list and use that when deleting routes.
831 */
832 ND6_RLOCK();
833 TAILQ_FOREACH(dr, &V_nd6_defrouter, dr_entry)
834 count++;
835 ND6_RUNLOCK();
836
837 dra = malloc(count * sizeof(*dra), M_TEMP, M_WAITOK | M_ZERO);
838
839 ND6_RLOCK();
840 TAILQ_FOREACH(dr, &V_nd6_defrouter, dr_entry) {
841 if (i == count)
842 break;
843 defrouter_ref(dr);
844 dra[i++] = dr;
845 }
846 ND6_RUNLOCK();
847
848 for (i = 0; i < count && dra[i] != NULL; i++) {
849 defrouter_delreq(dra[i]);
850 defrouter_rele(dra[i]);
851 }
852 free(dra, M_TEMP);
853
854 /*
855 * XXX should we also nuke any default routers in the kernel, by
856 * going through them by rtalloc1()?
857 */
858 }
859
860 /*
861 * Look up a matching default router list entry and remove it. Returns true if a
862 * matching entry was found, false otherwise.
863 */
864 bool
defrouter_remove(struct in6_addr * addr,struct ifnet * ifp)865 defrouter_remove(struct in6_addr *addr, struct ifnet *ifp)
866 {
867 struct nd_defrouter *dr;
868
869 ND6_WLOCK();
870 dr = defrouter_lookup_locked(addr, ifp);
871 if (dr == NULL) {
872 ND6_WUNLOCK();
873 return (false);
874 }
875
876 defrouter_unlink(dr, NULL);
877 ND6_WUNLOCK();
878 defrouter_del(dr);
879 defrouter_rele(dr);
880 return (true);
881 }
882
883 /*
884 * for default router selection
885 * regards router-preference field as a 2-bit signed integer
886 */
887 static int
rtpref(struct nd_defrouter * dr)888 rtpref(struct nd_defrouter *dr)
889 {
890 switch (dr->raflags & ND_RA_FLAG_RTPREF_MASK) {
891 case ND_RA_FLAG_RTPREF_HIGH:
892 return (RTPREF_HIGH);
893 case ND_RA_FLAG_RTPREF_MEDIUM:
894 case ND_RA_FLAG_RTPREF_RSV:
895 return (RTPREF_MEDIUM);
896 case ND_RA_FLAG_RTPREF_LOW:
897 return (RTPREF_LOW);
898 default:
899 /*
900 * This case should never happen. If it did, it would mean a
901 * serious bug of kernel internal. We thus always bark here.
902 * Or, can we even panic?
903 */
904 log(LOG_ERR, "rtpref: impossible RA flag %x\n", dr->raflags);
905 return (RTPREF_INVALID);
906 }
907 /* NOTREACHED */
908 }
909
910 static bool
is_dr_reachable(const struct nd_defrouter * dr)911 is_dr_reachable(const struct nd_defrouter *dr) {
912 struct llentry *ln = NULL;
913
914 ln = nd6_lookup(&dr->rtaddr, LLE_SF(AF_INET6, 0), dr->ifp);
915 if (ln == NULL)
916 return (false);
917 bool reachable = ND6_IS_LLINFO_PROBREACH(ln);
918 LLE_RUNLOCK(ln);
919 return reachable;
920 }
921
922 /*
923 * Default Router Selection according to Section 6.3.6 of RFC 2461 and
924 * draft-ietf-ipngwg-router-selection:
925 * 1) Routers that are reachable or probably reachable should be preferred.
926 * If we have more than one (probably) reachable router, prefer ones
927 * with the highest router preference.
928 * 2) When no routers on the list are known to be reachable or
929 * probably reachable, routers SHOULD be selected in a round-robin
930 * fashion, regardless of router preference values.
931 * 3) If the Default Router List is empty, assume that all
932 * destinations are on-link.
933 *
934 * We assume nd_defrouter is sorted by router preference value.
935 * Since the code below covers both with and without router preference cases,
936 * we do not need to classify the cases by ifdef.
937 *
938 * At this moment, we do not try to install more than one default router,
939 * even when the multipath routing is available, because we're not sure about
940 * the benefits for stub hosts comparing to the risk of making the code
941 * complicated and the possibility of introducing bugs.
942 *
943 * We maintain a single list of routers for multiple FIBs, only considering one
944 * at a time based on the receiving interface's FIB. If @fibnum is RT_ALL_FIBS,
945 * we do the whole thing multiple times.
946 */
947 void
defrouter_select_fib(int fibnum)948 defrouter_select_fib(int fibnum)
949 {
950 struct epoch_tracker et;
951 struct nd_defrouter *dr, *selected_dr, *installed_dr;
952
953 if (fibnum == RT_ALL_FIBS) {
954 for (fibnum = 0; fibnum < rt_numfibs; fibnum++) {
955 defrouter_select_fib(fibnum);
956 }
957 return;
958 }
959
960 ND6_RLOCK();
961 /*
962 * Let's handle easy case (3) first:
963 * If default router list is empty, there's nothing to be done.
964 */
965 if (TAILQ_EMPTY(&V_nd6_defrouter)) {
966 ND6_RUNLOCK();
967 return;
968 }
969
970 /*
971 * Search for a (probably) reachable router from the list.
972 * We just pick up the first reachable one (if any), assuming that
973 * the ordering rule of the list described in defrtrlist_update().
974 */
975 selected_dr = installed_dr = NULL;
976 NET_EPOCH_ENTER(et);
977 TAILQ_FOREACH(dr, &V_nd6_defrouter, dr_entry) {
978 if (dr->ifp->if_fib != fibnum)
979 continue;
980
981 if (selected_dr == NULL && is_dr_reachable(dr)) {
982 selected_dr = dr;
983 defrouter_ref(selected_dr);
984 }
985
986 if (dr->installed) {
987 if (installed_dr == NULL) {
988 installed_dr = dr;
989 defrouter_ref(installed_dr);
990 } else {
991 /*
992 * this should not happen.
993 * warn for diagnosis.
994 */
995 log(LOG_ERR, "defrouter_select_fib: more than "
996 "one router is installed\n");
997 }
998 }
999 }
1000
1001 /*
1002 * If none of the default routers was found to be reachable,
1003 * round-robin the list regardless of preference.
1004 * Otherwise, if we have an installed router, check if the selected
1005 * (reachable) router should really be preferred to the installed one.
1006 * We only prefer the new router when the old one is not reachable
1007 * or when the new one has a really higher preference value.
1008 */
1009 if (selected_dr == NULL) {
1010 if (installed_dr == NULL ||
1011 TAILQ_NEXT(installed_dr, dr_entry) == NULL)
1012 dr = TAILQ_FIRST(&V_nd6_defrouter);
1013 else
1014 dr = TAILQ_NEXT(installed_dr, dr_entry);
1015
1016 /* Ensure we select a router for this FIB. */
1017 TAILQ_FOREACH_FROM(dr, &V_nd6_defrouter, dr_entry) {
1018 if (dr->ifp->if_fib == fibnum) {
1019 selected_dr = dr;
1020 defrouter_ref(selected_dr);
1021 break;
1022 }
1023 }
1024 } else if (installed_dr != NULL) {
1025 if (is_dr_reachable(installed_dr) &&
1026 rtpref(selected_dr) <= rtpref(installed_dr)) {
1027 defrouter_rele(selected_dr);
1028 selected_dr = installed_dr;
1029 }
1030 }
1031 ND6_RUNLOCK();
1032
1033 /*
1034 * If we selected a router for this FIB and it's different
1035 * than the installed one, remove the installed router and
1036 * install the selected one in its place.
1037 */
1038 if (installed_dr != selected_dr) {
1039 if (installed_dr != NULL) {
1040 defrouter_delreq(installed_dr);
1041 defrouter_rele(installed_dr);
1042 }
1043 if (selected_dr != NULL)
1044 defrouter_addreq(selected_dr);
1045 }
1046 if (selected_dr != NULL)
1047 defrouter_rele(selected_dr);
1048 NET_EPOCH_EXIT(et);
1049 }
1050
1051 static struct nd_defrouter *
defrtrlist_update(struct nd_defrouter * new)1052 defrtrlist_update(struct nd_defrouter *new)
1053 {
1054 struct nd_defrouter *dr, *n;
1055 uint64_t genid;
1056 int oldpref;
1057 bool writelocked;
1058
1059 if (new->rtlifetime == 0) {
1060 defrouter_remove(&new->rtaddr, new->ifp);
1061 return (NULL);
1062 }
1063
1064 ND6_RLOCK();
1065 writelocked = false;
1066 restart:
1067 dr = defrouter_lookup_locked(&new->rtaddr, new->ifp);
1068 if (dr != NULL) {
1069 oldpref = rtpref(dr);
1070
1071 /* override */
1072 dr->raflags = new->raflags; /* XXX flag check */
1073 dr->rtlifetime = new->rtlifetime;
1074 dr->expire = new->expire;
1075
1076 /*
1077 * If the preference does not change, there's no need
1078 * to sort the entries. Also make sure the selected
1079 * router is still installed in the kernel.
1080 */
1081 if (dr->installed && rtpref(new) == oldpref) {
1082 if (writelocked)
1083 ND6_WUNLOCK();
1084 else
1085 ND6_RUNLOCK();
1086 return (dr);
1087 }
1088 }
1089
1090 /*
1091 * The router needs to be reinserted into the default router
1092 * list, so upgrade to a write lock. If that fails and the list
1093 * has potentially changed while the lock was dropped, we'll
1094 * redo the lookup with the write lock held.
1095 */
1096 if (!writelocked) {
1097 writelocked = true;
1098 if (!ND6_TRY_UPGRADE()) {
1099 genid = V_nd6_list_genid;
1100 ND6_RUNLOCK();
1101 ND6_WLOCK();
1102 if (genid != V_nd6_list_genid)
1103 goto restart;
1104 }
1105 }
1106
1107 if (dr != NULL) {
1108 /*
1109 * The preferred router may have changed, so relocate this
1110 * router.
1111 */
1112 TAILQ_REMOVE(&V_nd6_defrouter, dr, dr_entry);
1113 n = dr;
1114 } else {
1115 n = malloc(sizeof(*n), M_IP6NDP, M_NOWAIT | M_ZERO);
1116 if (n == NULL) {
1117 ND6_WUNLOCK();
1118 return (NULL);
1119 }
1120 memcpy(n, new, sizeof(*n));
1121 /* Initialize with an extra reference for the caller. */
1122 refcount_init(&n->refcnt, 2);
1123 }
1124
1125 /*
1126 * Insert the new router in the Default Router List;
1127 * The Default Router List should be in the descending order
1128 * of router-preferece. Routers with the same preference are
1129 * sorted in the arriving time order.
1130 */
1131
1132 /* insert at the end of the group */
1133 TAILQ_FOREACH(dr, &V_nd6_defrouter, dr_entry) {
1134 if (rtpref(n) > rtpref(dr))
1135 break;
1136 }
1137 if (dr != NULL)
1138 TAILQ_INSERT_BEFORE(dr, n, dr_entry);
1139 else
1140 TAILQ_INSERT_TAIL(&V_nd6_defrouter, n, dr_entry);
1141 V_nd6_list_genid++;
1142 ND6_WUNLOCK();
1143
1144 defrouter_select_fib(new->ifp->if_fib);
1145
1146 return (n);
1147 }
1148
1149 static int
in6_init_prefix_ltimes(struct nd_prefix * ndpr)1150 in6_init_prefix_ltimes(struct nd_prefix *ndpr)
1151 {
1152 if (ndpr->ndpr_pltime == ND6_INFINITE_LIFETIME)
1153 ndpr->ndpr_preferred = 0;
1154 else
1155 ndpr->ndpr_preferred = time_uptime + ndpr->ndpr_pltime;
1156 if (ndpr->ndpr_vltime == ND6_INFINITE_LIFETIME)
1157 ndpr->ndpr_expire = 0;
1158 else
1159 ndpr->ndpr_expire = time_uptime + ndpr->ndpr_vltime;
1160
1161 return 0;
1162 }
1163
1164 static void
in6_init_address_ltimes(struct nd_prefix * new,struct in6_addrlifetime * lt6)1165 in6_init_address_ltimes(struct nd_prefix *new, struct in6_addrlifetime *lt6)
1166 {
1167 /* init ia6t_expire */
1168 if (lt6->ia6t_vltime == ND6_INFINITE_LIFETIME)
1169 lt6->ia6t_expire = 0;
1170 else {
1171 lt6->ia6t_expire = time_uptime;
1172 lt6->ia6t_expire += lt6->ia6t_vltime;
1173 }
1174
1175 /* init ia6t_preferred */
1176 if (lt6->ia6t_pltime == ND6_INFINITE_LIFETIME)
1177 lt6->ia6t_preferred = 0;
1178 else {
1179 lt6->ia6t_preferred = time_uptime;
1180 lt6->ia6t_preferred += lt6->ia6t_pltime;
1181 }
1182 }
1183
1184 static struct in6_ifaddr *
in6_ifadd(struct nd_prefixctl * pr,int mcast)1185 in6_ifadd(struct nd_prefixctl *pr, int mcast)
1186 {
1187 struct ifnet *ifp = pr->ndpr_ifp;
1188 struct ifaddr *ifa;
1189 struct in6_aliasreq ifra;
1190 struct in6_ifaddr *ia = NULL, *ib = NULL;
1191 int error, plen0;
1192 struct in6_addr *ifid_addr = NULL, mask, newaddr;
1193 int prefixlen = pr->ndpr_plen;
1194 int updateflags;
1195 char ip6buf[INET6_ADDRSTRLEN];
1196
1197 in6_prefixlen2mask(&mask, prefixlen);
1198
1199 /*
1200 * find a link-local address (will be interface ID).
1201 * Is it really mandatory? Theoretically, a global or a site-local
1202 * address can be configured without a link-local address, if we
1203 * have a unique interface identifier...
1204 *
1205 * it is not mandatory to have a link-local address, we can generate
1206 * interface identifier on the fly. we do this because:
1207 * (1) it should be the easiest way to find interface identifier.
1208 * (2) RFC2462 5.4 suggesting the use of the same interface identifier
1209 * for multiple addresses on a single interface, and possible shortcut
1210 * of DAD. we omitted DAD for this reason in the past.
1211 * (3) a user can prevent autoconfiguration of global address
1212 * by removing link-local address by hand (this is partly because we
1213 * don't have other way to control the use of IPv6 on an interface.
1214 * this has been our design choice - cf. NRL's "ifconfig auto").
1215 * (4) it is easier to manage when an interface has addresses
1216 * with the same interface identifier, than to have multiple addresses
1217 * with different interface identifiers.
1218 *
1219 * If using stable privacy generation, generate a new address with
1220 * the algorithm specified in RFC 7217 section 5
1221 */
1222
1223 /* make ifaddr */
1224 in6_prepare_ifra(&ifra, &pr->ndpr_prefix.sin6_addr, &mask);
1225
1226 if (ND_IFINFO(ifp)->flags & ND6_IFF_STABLEADDR) {
1227 memcpy(&newaddr, &pr->ndpr_prefix.sin6_addr, sizeof(pr->ndpr_prefix.sin6_addr));
1228
1229 if(!in6_get_stableifid(ifp, &newaddr, prefixlen))
1230 return NULL;
1231 } else {
1232 ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp, 0); /* 0 is OK? */
1233 if (ifa) {
1234 ib = (struct in6_ifaddr *)ifa;
1235 ifid_addr = &ib->ia_addr.sin6_addr;
1236
1237 /* prefixlen + ifidlen must be equal to 128 */
1238 plen0 = in6_mask2len(&ib->ia_prefixmask.sin6_addr, NULL);
1239 if (prefixlen != plen0) {
1240 ifa_free(ifa);
1241 ifid_addr = NULL;
1242 nd6log((LOG_DEBUG,
1243 "%s: wrong prefixlen for %s (prefix=%d ifid=%d)\n",
1244 __func__, if_name(ifp), prefixlen, 128 - plen0));
1245 }
1246 }
1247
1248 /* No suitable LL address, get the ifid directly */
1249 if (ifid_addr == NULL) {
1250 ifa = ifa_alloc(sizeof(struct in6_ifaddr), M_NOWAIT);
1251 if (ifa != NULL) {
1252 ib = (struct in6_ifaddr *)ifa;
1253 ifid_addr = &ib->ia_addr.sin6_addr;
1254 if(in6_get_ifid(ifp, NULL, ifid_addr) != 0) {
1255 nd6log((LOG_DEBUG,
1256 "%s: failed to get ifid for %s\n",
1257 __func__, if_name(ifp)));
1258 ifa_free(ifa);
1259 ifid_addr = NULL;
1260 }
1261 }
1262 }
1263
1264 if (ifid_addr == NULL) {
1265 nd6log((LOG_INFO,
1266 "%s: could not determine ifid for %s\n",
1267 __func__, if_name(ifp)));
1268 return NULL;
1269 }
1270
1271 memcpy(&newaddr, &ib->ia_addr.sin6_addr, sizeof(ib->ia_addr.sin6_addr));
1272 ifa_free(ifa);
1273 }
1274
1275 IN6_MASK_ADDR(&ifra.ifra_addr.sin6_addr, &mask);
1276 /* interface ID */
1277 ifra.ifra_addr.sin6_addr.s6_addr32[0] |= (newaddr.s6_addr32[0] & ~mask.s6_addr32[0]);
1278 ifra.ifra_addr.sin6_addr.s6_addr32[1] |= (newaddr.s6_addr32[1] & ~mask.s6_addr32[1]);
1279 ifra.ifra_addr.sin6_addr.s6_addr32[2] |= (newaddr.s6_addr32[2] & ~mask.s6_addr32[2]);
1280 ifra.ifra_addr.sin6_addr.s6_addr32[3] |= (newaddr.s6_addr32[3] & ~mask.s6_addr32[3]);
1281
1282 /* lifetimes. */
1283 ifra.ifra_lifetime.ia6t_vltime = pr->ndpr_vltime;
1284 ifra.ifra_lifetime.ia6t_pltime = pr->ndpr_pltime;
1285
1286 /* XXX: scope zone ID? */
1287
1288 ifra.ifra_flags |= IN6_IFF_AUTOCONF; /* obey autoconf */
1289
1290 /*
1291 * Make sure that we do not have this address already. This should
1292 * usually not happen, but we can still see this case, e.g., if we
1293 * have manually configured the exact address to be configured.
1294 */
1295 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp,
1296 &ifra.ifra_addr.sin6_addr);
1297 if (ifa != NULL) {
1298 ifa_free(ifa);
1299 /* this should be rare enough to make an explicit log */
1300 log(LOG_INFO, "in6_ifadd: %s is already configured\n",
1301 ip6_sprintf(ip6buf, &ifra.ifra_addr.sin6_addr));
1302 return (NULL);
1303 }
1304
1305 /*
1306 * Allocate ifaddr structure, link into chain, etc.
1307 * If we are going to create a new address upon receiving a multicasted
1308 * RA, we need to impose a random delay before starting DAD.
1309 * [draft-ietf-ipv6-rfc2462bis-02.txt, Section 5.4.2]
1310 */
1311 updateflags = 0;
1312 if (mcast)
1313 updateflags |= IN6_IFAUPDATE_DADDELAY;
1314 if ((error = in6_update_ifa(ifp, &ifra, NULL, updateflags)) != 0) {
1315 nd6log((LOG_ERR,
1316 "%s: failed to make ifaddr %s on %s (errno=%d)\n", __func__,
1317 ip6_sprintf(ip6buf, &ifra.ifra_addr.sin6_addr),
1318 if_name(ifp), error));
1319 return (NULL); /* ifaddr must not have been allocated. */
1320 }
1321
1322 ia = in6ifa_ifpwithaddr(ifp, &ifra.ifra_addr.sin6_addr);
1323 /*
1324 * XXXRW: Assumption of non-NULLness here might not be true with
1325 * fine-grained locking -- should we validate it? Or just return
1326 * earlier ifa rather than looking it up again?
1327 */
1328 return (ia); /* this is always non-NULL and referenced. */
1329 }
1330
1331 static struct nd_prefix *
nd6_prefix_lookup_locked(struct nd_prefixctl * key)1332 nd6_prefix_lookup_locked(struct nd_prefixctl *key)
1333 {
1334 struct nd_prefix *search;
1335
1336 ND6_LOCK_ASSERT();
1337
1338 LIST_FOREACH(search, &V_nd_prefix, ndpr_entry) {
1339 if (key->ndpr_ifp == search->ndpr_ifp &&
1340 key->ndpr_plen == search->ndpr_plen &&
1341 in6_are_prefix_equal(&key->ndpr_prefix.sin6_addr,
1342 &search->ndpr_prefix.sin6_addr, key->ndpr_plen)) {
1343 nd6_prefix_ref(search);
1344 break;
1345 }
1346 }
1347 return (search);
1348 }
1349
1350 struct nd_prefix *
nd6_prefix_lookup(struct nd_prefixctl * key)1351 nd6_prefix_lookup(struct nd_prefixctl *key)
1352 {
1353 struct nd_prefix *search;
1354
1355 ND6_RLOCK();
1356 search = nd6_prefix_lookup_locked(key);
1357 ND6_RUNLOCK();
1358 return (search);
1359 }
1360
1361 void
nd6_prefix_ref(struct nd_prefix * pr)1362 nd6_prefix_ref(struct nd_prefix *pr)
1363 {
1364
1365 refcount_acquire(&pr->ndpr_refcnt);
1366 }
1367
1368 void
nd6_prefix_rele(struct nd_prefix * pr)1369 nd6_prefix_rele(struct nd_prefix *pr)
1370 {
1371
1372 if (refcount_release(&pr->ndpr_refcnt)) {
1373 KASSERT(LIST_EMPTY(&pr->ndpr_advrtrs),
1374 ("prefix %p has advertising routers", pr));
1375 free(pr, M_IP6NDP);
1376 }
1377 }
1378
1379 int
nd6_prelist_add(struct nd_prefixctl * pr,struct nd_defrouter * dr,struct nd_prefix ** newp)1380 nd6_prelist_add(struct nd_prefixctl *pr, struct nd_defrouter *dr,
1381 struct nd_prefix **newp)
1382 {
1383 struct nd_prefix *new;
1384 char ip6buf[INET6_ADDRSTRLEN];
1385 int error;
1386
1387 new = malloc(sizeof(*new), M_IP6NDP, M_NOWAIT | M_ZERO);
1388 if (new == NULL)
1389 return (ENOMEM);
1390 refcount_init(&new->ndpr_refcnt, newp != NULL ? 2 : 1);
1391 new->ndpr_ifp = pr->ndpr_ifp;
1392 new->ndpr_prefix = pr->ndpr_prefix;
1393 new->ndpr_plen = pr->ndpr_plen;
1394 new->ndpr_vltime = pr->ndpr_vltime;
1395 new->ndpr_pltime = pr->ndpr_pltime;
1396 new->ndpr_flags = pr->ndpr_flags;
1397 if ((error = in6_init_prefix_ltimes(new)) != 0) {
1398 free(new, M_IP6NDP);
1399 return (error);
1400 }
1401 new->ndpr_lastupdate = time_uptime;
1402
1403 /* initialization */
1404 LIST_INIT(&new->ndpr_advrtrs);
1405 in6_prefixlen2mask(&new->ndpr_mask, new->ndpr_plen);
1406 /* make prefix in the canonical form */
1407 IN6_MASK_ADDR(&new->ndpr_prefix.sin6_addr, &new->ndpr_mask);
1408
1409 ND6_WLOCK();
1410 LIST_INSERT_HEAD(&V_nd_prefix, new, ndpr_entry);
1411 V_nd6_list_genid++;
1412 ND6_WUNLOCK();
1413
1414 /* ND_OPT_PI_FLAG_ONLINK processing */
1415 if (new->ndpr_raf_onlink) {
1416 struct epoch_tracker et;
1417
1418 ND6_ONLINK_LOCK();
1419 NET_EPOCH_ENTER(et);
1420 if ((error = nd6_prefix_onlink(new)) != 0) {
1421 nd6log((LOG_ERR, "%s: failed to make the prefix %s/%d "
1422 "on-link on %s (errno=%d)\n", __func__,
1423 ip6_sprintf(ip6buf, &pr->ndpr_prefix.sin6_addr),
1424 pr->ndpr_plen, if_name(pr->ndpr_ifp), error));
1425 /* proceed anyway. XXX: is it correct? */
1426 }
1427 NET_EPOCH_EXIT(et);
1428 ND6_ONLINK_UNLOCK();
1429 }
1430
1431 if (dr != NULL)
1432 pfxrtr_add(new, dr);
1433 if (newp != NULL)
1434 *newp = new;
1435 return (0);
1436 }
1437
1438 /*
1439 * Remove a prefix from the prefix list and optionally stash it in a
1440 * caller-provided list.
1441 *
1442 * The ND6 lock must be held.
1443 */
1444 void
nd6_prefix_unlink(struct nd_prefix * pr,struct nd_prhead * list)1445 nd6_prefix_unlink(struct nd_prefix *pr, struct nd_prhead *list)
1446 {
1447
1448 ND6_WLOCK_ASSERT();
1449
1450 LIST_REMOVE(pr, ndpr_entry);
1451 V_nd6_list_genid++;
1452 if (list != NULL)
1453 LIST_INSERT_HEAD(list, pr, ndpr_entry);
1454 }
1455
1456 /*
1457 * Free an unlinked prefix, first marking it off-link if necessary.
1458 */
1459 void
nd6_prefix_del(struct nd_prefix * pr)1460 nd6_prefix_del(struct nd_prefix *pr)
1461 {
1462 struct nd_pfxrouter *pfr, *next;
1463 int e;
1464 char ip6buf[INET6_ADDRSTRLEN];
1465
1466 KASSERT(pr->ndpr_addrcnt == 0,
1467 ("prefix %p has referencing addresses", pr));
1468 ND6_UNLOCK_ASSERT();
1469
1470 /*
1471 * Though these flags are now meaningless, we'd rather keep the value
1472 * of pr->ndpr_raf_onlink and pr->ndpr_raf_auto not to confuse users
1473 * when executing "ndp -p".
1474 */
1475 if ((pr->ndpr_stateflags & NDPRF_ONLINK) != 0) {
1476 ND6_ONLINK_LOCK();
1477 if ((e = nd6_prefix_offlink(pr)) != 0) {
1478 nd6log((LOG_ERR,
1479 "%s: failed to make the prefix %s/%d offlink on %s "
1480 "(errno=%d)\n", __func__,
1481 ip6_sprintf(ip6buf, &pr->ndpr_prefix.sin6_addr),
1482 pr->ndpr_plen, if_name(pr->ndpr_ifp), e));
1483 /* what should we do? */
1484 }
1485 ND6_ONLINK_UNLOCK();
1486 }
1487
1488 /* Release references to routers that have advertised this prefix. */
1489 ND6_WLOCK();
1490 LIST_FOREACH_SAFE(pfr, &pr->ndpr_advrtrs, pfr_entry, next)
1491 pfxrtr_del(pfr);
1492 ND6_WUNLOCK();
1493
1494 nd6_prefix_rele(pr);
1495
1496 pfxlist_onlink_check();
1497 }
1498
1499 static int
prelist_update(struct nd_prefixctl * new,struct nd_defrouter * dr,struct mbuf * m,int mcast)1500 prelist_update(struct nd_prefixctl *new, struct nd_defrouter *dr,
1501 struct mbuf *m, int mcast)
1502 {
1503 struct in6_ifaddr *ia6 = NULL, *ia6_match = NULL;
1504 struct ifaddr *ifa;
1505 struct ifnet *ifp = new->ndpr_ifp;
1506 struct nd_prefix *pr;
1507 int error = 0;
1508 int auth;
1509 struct in6_addrlifetime lt6_tmp;
1510 char ip6buf[INET6_ADDRSTRLEN];
1511 bool has_temporary = false;
1512
1513 NET_EPOCH_ASSERT();
1514
1515 auth = 0;
1516 if (m) {
1517 /*
1518 * Authenticity for NA consists authentication for
1519 * both IP header and IP datagrams, doesn't it ?
1520 */
1521 #if defined(M_AUTHIPHDR) && defined(M_AUTHIPDGM)
1522 auth = ((m->m_flags & M_AUTHIPHDR) &&
1523 (m->m_flags & M_AUTHIPDGM));
1524 #endif
1525 }
1526
1527 if ((pr = nd6_prefix_lookup(new)) != NULL) {
1528 /*
1529 * nd6_prefix_lookup() ensures that pr and new have the same
1530 * prefix on a same interface.
1531 */
1532
1533 /*
1534 * Update prefix information. Note that the on-link (L) bit
1535 * and the autonomous (A) bit should NOT be changed from 1
1536 * to 0.
1537 */
1538 if (new->ndpr_raf_onlink == 1)
1539 pr->ndpr_raf_onlink = 1;
1540 if (new->ndpr_raf_auto == 1)
1541 pr->ndpr_raf_auto = 1;
1542 if (new->ndpr_raf_onlink) {
1543 pr->ndpr_vltime = new->ndpr_vltime;
1544 pr->ndpr_pltime = new->ndpr_pltime;
1545 (void)in6_init_prefix_ltimes(pr); /* XXX error case? */
1546 pr->ndpr_lastupdate = time_uptime;
1547 }
1548
1549 if (new->ndpr_raf_onlink &&
1550 (pr->ndpr_stateflags & NDPRF_ONLINK) == 0) {
1551 ND6_ONLINK_LOCK();
1552 if ((error = nd6_prefix_onlink(pr)) != 0) {
1553 nd6log((LOG_ERR,
1554 "%s: failed to make the prefix %s/%d "
1555 "on-link on %s (errno=%d)\n", __func__,
1556 ip6_sprintf(ip6buf,
1557 &pr->ndpr_prefix.sin6_addr),
1558 pr->ndpr_plen, if_name(pr->ndpr_ifp),
1559 error));
1560 /* proceed anyway. XXX: is it correct? */
1561 }
1562 ND6_ONLINK_UNLOCK();
1563 }
1564
1565 if (dr != NULL)
1566 pfxrtr_add(pr, dr);
1567 } else {
1568 if (new->ndpr_vltime == 0)
1569 goto end;
1570 if (new->ndpr_raf_onlink == 0 && new->ndpr_raf_auto == 0)
1571 goto end;
1572
1573 error = nd6_prelist_add(new, dr, &pr);
1574 if (error != 0) {
1575 nd6log((LOG_NOTICE, "%s: nd6_prelist_add() failed for "
1576 "the prefix %s/%d on %s (errno=%d)\n", __func__,
1577 ip6_sprintf(ip6buf, &new->ndpr_prefix.sin6_addr),
1578 new->ndpr_plen, if_name(new->ndpr_ifp), error));
1579 goto end; /* we should just give up in this case. */
1580 }
1581
1582 /*
1583 * XXX: from the ND point of view, we can ignore a prefix
1584 * with the on-link bit being zero. However, we need a
1585 * prefix structure for references from autoconfigured
1586 * addresses. Thus, we explicitly make sure that the prefix
1587 * itself expires now.
1588 */
1589 if (pr->ndpr_raf_onlink == 0) {
1590 pr->ndpr_vltime = 0;
1591 pr->ndpr_pltime = 0;
1592 in6_init_prefix_ltimes(pr);
1593 }
1594 }
1595
1596 /*
1597 * Address autoconfiguration based on Section 5.5.3 of RFC 2462.
1598 * Note that pr must be non NULL at this point.
1599 */
1600
1601 /* 5.5.3 (a). Ignore the prefix without the A bit set. */
1602 if (!new->ndpr_raf_auto)
1603 goto end;
1604
1605 /*
1606 * 5.5.3 (b). the link-local prefix should have been ignored in
1607 * nd6_ra_input.
1608 */
1609
1610 /* 5.5.3 (c). Consistency check on lifetimes: pltime <= vltime. */
1611 if (new->ndpr_pltime > new->ndpr_vltime) {
1612 error = EINVAL; /* XXX: won't be used */
1613 goto end;
1614 }
1615
1616 /*
1617 * 5.5.3 (d). If the prefix advertised is not equal to the prefix of
1618 * an address configured by stateless autoconfiguration already in the
1619 * list of addresses associated with the interface, and the Valid
1620 * Lifetime is not 0, form an address. We first check if we have
1621 * a matching prefix.
1622 * Note: we apply a clarification in rfc2462bis-02 here. We only
1623 * consider autoconfigured addresses while RFC2462 simply said
1624 * "address".
1625 */
1626 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1627 struct in6_ifaddr *ifa6;
1628 u_int32_t remaininglifetime;
1629
1630 if (ifa->ifa_addr->sa_family != AF_INET6)
1631 continue;
1632
1633 ifa6 = (struct in6_ifaddr *)ifa;
1634
1635 /*
1636 * We only consider autoconfigured addresses as per rfc2462bis.
1637 */
1638 if (!(ifa6->ia6_flags & IN6_IFF_AUTOCONF))
1639 continue;
1640
1641 /*
1642 * Spec is not clear here, but I believe we should concentrate
1643 * on unicast (i.e. not anycast) addresses.
1644 * XXX: other ia6_flags? detached or duplicated?
1645 */
1646 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0)
1647 continue;
1648
1649 /*
1650 * Ignore the address if it is not associated with a prefix
1651 * or is associated with a prefix that is different from this
1652 * one. (pr is never NULL here)
1653 */
1654 if (ifa6->ia6_ndpr != pr)
1655 continue;
1656
1657 /*
1658 * An already autoconfigured address matched. Now that we
1659 * are sure there is at least one matched address, we can
1660 * proceed to 5.5.3. (e): update the lifetimes according to the
1661 * "two hours" rule and the privacy extension.
1662 * We apply some clarifications in rfc2462bis:
1663 * - use remaininglifetime instead of storedlifetime as a
1664 * variable name
1665 * - remove the dead code in the "two-hour" rule
1666 */
1667 #define TWOHOUR (120*60)
1668 lt6_tmp = ifa6->ia6_lifetime;
1669
1670 if (lt6_tmp.ia6t_vltime == ND6_INFINITE_LIFETIME)
1671 remaininglifetime = ND6_INFINITE_LIFETIME;
1672 else if (time_uptime - ifa6->ia6_updatetime >
1673 lt6_tmp.ia6t_vltime) {
1674 /*
1675 * The case of "invalid" address. We should usually
1676 * not see this case.
1677 */
1678 remaininglifetime = 0;
1679 } else
1680 remaininglifetime = lt6_tmp.ia6t_vltime -
1681 (time_uptime - ifa6->ia6_updatetime);
1682
1683 /* when not updating, keep the current stored lifetime. */
1684 lt6_tmp.ia6t_vltime = remaininglifetime;
1685
1686 if (TWOHOUR < new->ndpr_vltime ||
1687 remaininglifetime < new->ndpr_vltime) {
1688 lt6_tmp.ia6t_vltime = new->ndpr_vltime;
1689 } else if (remaininglifetime <= TWOHOUR) {
1690 if (auth) {
1691 lt6_tmp.ia6t_vltime = new->ndpr_vltime;
1692 }
1693 } else {
1694 /*
1695 * new->ndpr_vltime <= TWOHOUR &&
1696 * TWOHOUR < remaininglifetime
1697 */
1698 lt6_tmp.ia6t_vltime = TWOHOUR;
1699 }
1700
1701 /* The 2 hour rule is not imposed for preferred lifetime. */
1702 lt6_tmp.ia6t_pltime = new->ndpr_pltime;
1703
1704 in6_init_address_ltimes(pr, <6_tmp);
1705
1706 /*
1707 * We need to treat lifetimes for temporary addresses
1708 * differently, according to
1709 * draft-ietf-ipv6-privacy-addrs-v2-01.txt 3.3 (1);
1710 * we only update the lifetimes when they are in the maximum
1711 * intervals.
1712 */
1713 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0) {
1714 u_int32_t maxvltime, maxpltime;
1715
1716 /*
1717 * if stable addresses (RFC 7217) are enabled, mark that a temporary address has been found
1718 * to avoid generating uneeded extra ones.
1719 */
1720 if (ND_IFINFO(ifp)->flags & ND6_IFF_STABLEADDR)
1721 has_temporary = true;
1722
1723 if (V_ip6_temp_valid_lifetime >
1724 (u_int32_t)((time_uptime - ifa6->ia6_createtime) +
1725 V_ip6_desync_factor)) {
1726 maxvltime = V_ip6_temp_valid_lifetime -
1727 (time_uptime - ifa6->ia6_createtime) -
1728 V_ip6_desync_factor;
1729 } else
1730 maxvltime = 0;
1731 if (V_ip6_temp_preferred_lifetime >
1732 (u_int32_t)((time_uptime - ifa6->ia6_createtime) +
1733 V_ip6_desync_factor)) {
1734 maxpltime = V_ip6_temp_preferred_lifetime -
1735 (time_uptime - ifa6->ia6_createtime) -
1736 V_ip6_desync_factor;
1737 } else
1738 maxpltime = 0;
1739
1740 if (lt6_tmp.ia6t_vltime == ND6_INFINITE_LIFETIME ||
1741 lt6_tmp.ia6t_vltime > maxvltime) {
1742 lt6_tmp.ia6t_vltime = maxvltime;
1743 }
1744 if (lt6_tmp.ia6t_pltime == ND6_INFINITE_LIFETIME ||
1745 lt6_tmp.ia6t_pltime > maxpltime) {
1746 lt6_tmp.ia6t_pltime = maxpltime;
1747 }
1748 }
1749 ifa6->ia6_lifetime = lt6_tmp;
1750 ifa6->ia6_updatetime = time_uptime;
1751
1752 /*
1753 * If using stable addresses (RFC 7217) and we still have retries to perform, ignore
1754 * addresses already marked as duplicated, since a new one will be generated.
1755 * Also ignore addresses marked as temporary, since their generation is orthogonal to
1756 * opaque stable ones.
1757 *
1758 * There is a small race condition, in that the dad_counter could be incremented
1759 * between here and when a new address is generated, but this will cause that generation
1760 * to fail and no further retries should happen.
1761 */
1762 if (ND_IFINFO(ifp)->flags & ND6_IFF_STABLEADDR &&
1763 atomic_load_int(&DAD_FAILURES(ifp)) <= V_ip6_stableaddr_maxretries &&
1764 ifa6->ia6_flags & (IN6_IFF_DUPLICATED | IN6_IFF_TEMPORARY))
1765 continue;
1766
1767 if (ia6_match == NULL) /* remember the first one */
1768 ia6_match = ifa6;
1769 }
1770 if (ia6_match == NULL && new->ndpr_vltime) {
1771 int ifidlen;
1772
1773 /*
1774 * 5.5.3 (d) (continued)
1775 * No address matched and the valid lifetime is non-zero.
1776 * Create a new address.
1777 */
1778
1779 /*
1780 * Prefix Length check:
1781 * If the sum of the prefix length and interface identifier
1782 * length does not equal 128 bits, the Prefix Information
1783 * option MUST be ignored. The length of the interface
1784 * identifier is defined in a separate link-type specific
1785 * document.
1786 */
1787 ifidlen = in6_if2idlen(ifp);
1788 if (ifidlen < 0) {
1789 /* this should not happen, so we always log it. */
1790 log(LOG_ERR, "prelist_update: IFID undefined (%s)\n",
1791 if_name(ifp));
1792 goto end;
1793 }
1794 if (ifidlen + pr->ndpr_plen != 128) {
1795 nd6log((LOG_INFO,
1796 "%s: invalid prefixlen %d for %s, ignored\n",
1797 __func__, pr->ndpr_plen, if_name(ifp)));
1798 goto end;
1799 }
1800
1801 if ((ia6 = in6_ifadd(new, mcast)) != NULL) {
1802 /*
1803 * note that we should use pr (not new) for reference.
1804 */
1805 pr->ndpr_addrcnt++;
1806 ia6->ia6_ndpr = pr;
1807
1808 /*
1809 * RFC 3041 3.3 (2).
1810 * When a new public address is created as described
1811 * in RFC2462, also create a new temporary address.
1812 *
1813 * RFC 3041 3.5.
1814 * When an interface connects to a new link, a new
1815 * randomized interface identifier should be generated
1816 * immediately together with a new set of temporary
1817 * addresses. Thus, we specifiy 1 as the 2nd arg of
1818 * in6_tmpifadd().
1819 *
1820 * Skip this if a temporary address has been marked as
1821 * found (happens only if stable addresses (RFC 7217) is in use)
1822 */
1823 if (V_ip6_use_tempaddr && !has_temporary) {
1824 int e;
1825 if ((e = in6_tmpifadd(ia6, 1, 1)) != 0) {
1826 nd6log((LOG_NOTICE, "%s: failed to "
1827 "create a temporary address "
1828 "(errno=%d)\n", __func__, e));
1829 }
1830 }
1831 ifa_free(&ia6->ia_ifa);
1832
1833 /*
1834 * A newly added address might affect the status
1835 * of other addresses, so we check and update it.
1836 * XXX: what if address duplication happens?
1837 */
1838 pfxlist_onlink_check();
1839 } else {
1840 /* just set an error. do not bark here. */
1841 error = EADDRNOTAVAIL; /* XXX: might be unused. */
1842 }
1843 }
1844
1845 end:
1846 if (pr != NULL)
1847 nd6_prefix_rele(pr);
1848 return (error);
1849 }
1850
1851 /*
1852 * A supplement function used in the on-link detection below;
1853 * detect if a given prefix has a (probably) reachable advertising router.
1854 * XXX: lengthy function name...
1855 */
1856 static struct nd_pfxrouter *
find_pfxlist_reachable_router(struct nd_prefix * pr)1857 find_pfxlist_reachable_router(struct nd_prefix *pr)
1858 {
1859 struct epoch_tracker et;
1860 struct nd_pfxrouter *pfxrtr;
1861
1862 ND6_LOCK_ASSERT();
1863
1864 NET_EPOCH_ENTER(et);
1865 LIST_FOREACH(pfxrtr, &pr->ndpr_advrtrs, pfr_entry) {
1866 if (is_dr_reachable(pfxrtr->router))
1867 break;
1868 }
1869 NET_EPOCH_EXIT(et);
1870 return (pfxrtr);
1871 }
1872
1873 /*
1874 * Check if each prefix in the prefix list has at least one available router
1875 * that advertised the prefix (a router is "available" if its neighbor cache
1876 * entry is reachable or probably reachable).
1877 * If the check fails, the prefix may be off-link, because, for example,
1878 * we have moved from the network but the lifetime of the prefix has not
1879 * expired yet. So we should not use the prefix if there is another prefix
1880 * that has an available router.
1881 * But, if there is no prefix that has an available router, we still regard
1882 * all the prefixes as on-link. This is because we can't tell if all the
1883 * routers are simply dead or if we really moved from the network and there
1884 * is no router around us.
1885 */
1886 void
pfxlist_onlink_check(void)1887 pfxlist_onlink_check(void)
1888 {
1889 struct nd_prefix *pr;
1890 struct in6_ifaddr *ifa;
1891 struct nd_defrouter *dr;
1892 struct nd_pfxrouter *pfxrtr = NULL;
1893 struct rm_priotracker in6_ifa_tracker;
1894 uint64_t genid;
1895 uint32_t flags;
1896
1897 ND6_ONLINK_LOCK();
1898 ND6_RLOCK();
1899
1900 /*
1901 * Check if there is a prefix that has a reachable advertising
1902 * router.
1903 */
1904 LIST_FOREACH(pr, &V_nd_prefix, ndpr_entry) {
1905 if (pr->ndpr_raf_onlink && find_pfxlist_reachable_router(pr))
1906 break;
1907 }
1908
1909 /*
1910 * If we have no such prefix, check whether we still have a router
1911 * that does not advertise any prefixes.
1912 */
1913 if (pr == NULL) {
1914 TAILQ_FOREACH(dr, &V_nd6_defrouter, dr_entry) {
1915 struct nd_prefix *pr0;
1916
1917 LIST_FOREACH(pr0, &V_nd_prefix, ndpr_entry) {
1918 if ((pfxrtr = pfxrtr_lookup(pr0, dr)) != NULL)
1919 break;
1920 }
1921 if (pfxrtr != NULL)
1922 break;
1923 }
1924 }
1925 if (pr != NULL || (!TAILQ_EMPTY(&V_nd6_defrouter) && pfxrtr == NULL)) {
1926 /*
1927 * There is at least one prefix that has a reachable router,
1928 * or at least a router which probably does not advertise
1929 * any prefixes. The latter would be the case when we move
1930 * to a new link where we have a router that does not provide
1931 * prefixes and we configure an address by hand.
1932 * Detach prefixes which have no reachable advertising
1933 * router, and attach other prefixes.
1934 */
1935 LIST_FOREACH(pr, &V_nd_prefix, ndpr_entry) {
1936 /* XXX: a link-local prefix should never be detached */
1937 if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr) ||
1938 pr->ndpr_raf_onlink == 0 ||
1939 pr->ndpr_raf_auto == 0)
1940 continue;
1941
1942 if ((pr->ndpr_stateflags & NDPRF_DETACHED) == 0 &&
1943 find_pfxlist_reachable_router(pr) == NULL)
1944 pr->ndpr_stateflags |= NDPRF_DETACHED;
1945 else if ((pr->ndpr_stateflags & NDPRF_DETACHED) != 0 &&
1946 find_pfxlist_reachable_router(pr) != NULL)
1947 pr->ndpr_stateflags &= ~NDPRF_DETACHED;
1948 }
1949 } else {
1950 /* there is no prefix that has a reachable router */
1951 LIST_FOREACH(pr, &V_nd_prefix, ndpr_entry) {
1952 if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr) ||
1953 pr->ndpr_raf_onlink == 0 ||
1954 pr->ndpr_raf_auto == 0)
1955 continue;
1956 pr->ndpr_stateflags &= ~NDPRF_DETACHED;
1957 }
1958 }
1959
1960 /*
1961 * Remove each interface route associated with a (just) detached
1962 * prefix, and reinstall the interface route for a (just) attached
1963 * prefix. Note that all attempt of reinstallation does not
1964 * necessarily success, when a same prefix is shared among multiple
1965 * interfaces. Such cases will be handled in nd6_prefix_onlink,
1966 * so we don't have to care about them.
1967 */
1968 restart:
1969 LIST_FOREACH(pr, &V_nd_prefix, ndpr_entry) {
1970 char ip6buf[INET6_ADDRSTRLEN];
1971 int e;
1972
1973 if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr) ||
1974 pr->ndpr_raf_onlink == 0 ||
1975 pr->ndpr_raf_auto == 0)
1976 continue;
1977
1978 flags = pr->ndpr_stateflags & (NDPRF_DETACHED | NDPRF_ONLINK);
1979 if (flags == 0 || flags == (NDPRF_DETACHED | NDPRF_ONLINK)) {
1980 genid = V_nd6_list_genid;
1981 ND6_RUNLOCK();
1982 if ((flags & NDPRF_ONLINK) != 0 &&
1983 (e = nd6_prefix_offlink(pr)) != 0) {
1984 nd6log((LOG_ERR,
1985 "%s: failed to make %s/%d offlink "
1986 "(errno=%d)\n", __func__,
1987 ip6_sprintf(ip6buf,
1988 &pr->ndpr_prefix.sin6_addr),
1989 pr->ndpr_plen, e));
1990 } else if ((flags & NDPRF_ONLINK) == 0 &&
1991 (e = nd6_prefix_onlink(pr)) != 0) {
1992 nd6log((LOG_ERR,
1993 "%s: failed to make %s/%d onlink "
1994 "(errno=%d)\n", __func__,
1995 ip6_sprintf(ip6buf,
1996 &pr->ndpr_prefix.sin6_addr),
1997 pr->ndpr_plen, e));
1998 }
1999 ND6_RLOCK();
2000 if (genid != V_nd6_list_genid)
2001 goto restart;
2002 }
2003 }
2004
2005 /*
2006 * Changes on the prefix status might affect address status as well.
2007 * Make sure that all addresses derived from an attached prefix are
2008 * attached, and that all addresses derived from a detached prefix are
2009 * detached. Note, however, that a manually configured address should
2010 * always be attached.
2011 * The precise detection logic is same as the one for prefixes.
2012 */
2013 IN6_IFADDR_RLOCK(&in6_ifa_tracker);
2014 CK_STAILQ_FOREACH(ifa, &V_in6_ifaddrhead, ia_link) {
2015 if (!(ifa->ia6_flags & IN6_IFF_AUTOCONF))
2016 continue;
2017
2018 if (ifa->ia6_ndpr == NULL) {
2019 /*
2020 * This can happen when we first configure the address
2021 * (i.e. the address exists, but the prefix does not).
2022 * XXX: complicated relationships...
2023 */
2024 continue;
2025 }
2026
2027 if (find_pfxlist_reachable_router(ifa->ia6_ndpr))
2028 break;
2029 }
2030 if (ifa) {
2031 CK_STAILQ_FOREACH(ifa, &V_in6_ifaddrhead, ia_link) {
2032 if ((ifa->ia6_flags & IN6_IFF_AUTOCONF) == 0)
2033 continue;
2034
2035 if (ifa->ia6_ndpr == NULL) /* XXX: see above. */
2036 continue;
2037
2038 if (find_pfxlist_reachable_router(ifa->ia6_ndpr)) {
2039 if (ifa->ia6_flags & IN6_IFF_DETACHED) {
2040 ifa->ia6_flags &= ~IN6_IFF_DETACHED;
2041 ifa->ia6_flags |= IN6_IFF_TENTATIVE;
2042 nd6_dad_start((struct ifaddr *)ifa, 0);
2043 }
2044 } else {
2045 ifa->ia6_flags |= IN6_IFF_DETACHED;
2046 }
2047 }
2048 } else {
2049 CK_STAILQ_FOREACH(ifa, &V_in6_ifaddrhead, ia_link) {
2050 if ((ifa->ia6_flags & IN6_IFF_AUTOCONF) == 0)
2051 continue;
2052
2053 if (ifa->ia6_flags & IN6_IFF_DETACHED) {
2054 ifa->ia6_flags &= ~IN6_IFF_DETACHED;
2055 ifa->ia6_flags |= IN6_IFF_TENTATIVE;
2056 /* Do we need a delay in this case? */
2057 nd6_dad_start((struct ifaddr *)ifa, 0);
2058 }
2059 }
2060 }
2061 IN6_IFADDR_RUNLOCK(&in6_ifa_tracker);
2062 ND6_RUNLOCK();
2063 ND6_ONLINK_UNLOCK();
2064 }
2065
2066 /*
2067 * Add or remove interface route specified by @dst, @netmask and @ifp.
2068 * ifa can be NULL.
2069 * Returns 0 on success
2070 */
2071 static int
nd6_prefix_rtrequest(uint32_t fibnum,int cmd,struct sockaddr_in6 * dst,struct sockaddr_in6 * netmask,struct ifnet * ifp,struct ifaddr * ifa)2072 nd6_prefix_rtrequest(uint32_t fibnum, int cmd, struct sockaddr_in6 *dst,
2073 struct sockaddr_in6 *netmask, struct ifnet *ifp, struct ifaddr *ifa)
2074 {
2075 struct epoch_tracker et;
2076 int error;
2077
2078 /* Prepare gateway */
2079 struct sockaddr_dl_short sdl = {
2080 .sdl_family = AF_LINK,
2081 .sdl_len = sizeof(struct sockaddr_dl_short),
2082 .sdl_type = ifp->if_type,
2083 .sdl_index = ifp->if_index,
2084 };
2085
2086 struct rt_addrinfo info = {
2087 .rti_ifa = ifa,
2088 .rti_ifp = ifp,
2089 .rti_flags = RTF_PINNED | ((netmask != NULL) ? 0 : RTF_HOST),
2090 .rti_info = {
2091 [RTAX_DST] = (struct sockaddr *)dst,
2092 [RTAX_NETMASK] = (struct sockaddr *)netmask,
2093 [RTAX_GATEWAY] = (struct sockaddr *)&sdl,
2094 },
2095 };
2096 /* Don't set additional per-gw filters on removal */
2097
2098 NET_EPOCH_ENTER(et);
2099 error = rib_handle_ifaddr_info(fibnum, cmd, &info);
2100 NET_EPOCH_EXIT(et);
2101 return (error);
2102 }
2103
2104 static int
nd6_prefix_onlink_rtrequest(struct nd_prefix * pr,struct ifaddr * ifa)2105 nd6_prefix_onlink_rtrequest(struct nd_prefix *pr, struct ifaddr *ifa)
2106 {
2107 int error;
2108
2109 struct sockaddr_in6 mask6 = {
2110 .sin6_family = AF_INET6,
2111 .sin6_len = sizeof(struct sockaddr_in6),
2112 .sin6_addr = pr->ndpr_mask,
2113 };
2114 struct sockaddr_in6 *pmask6 = (pr->ndpr_plen != 128) ? &mask6 : NULL;
2115
2116 error = nd6_prefix_rtrequest(pr->ndpr_ifp->if_fib, RTM_ADD,
2117 &pr->ndpr_prefix, pmask6, pr->ndpr_ifp, ifa);
2118 if (error == 0)
2119 pr->ndpr_stateflags |= NDPRF_ONLINK;
2120
2121 return (error);
2122 }
2123
2124 static int
nd6_prefix_onlink(struct nd_prefix * pr)2125 nd6_prefix_onlink(struct nd_prefix *pr)
2126 {
2127 struct epoch_tracker et;
2128 struct ifaddr *ifa;
2129 struct ifnet *ifp = pr->ndpr_ifp;
2130 struct nd_prefix *opr;
2131 char ip6buf[INET6_ADDRSTRLEN];
2132 int error;
2133
2134 ND6_ONLINK_LOCK_ASSERT();
2135 ND6_UNLOCK_ASSERT();
2136
2137 if ((pr->ndpr_stateflags & NDPRF_ONLINK) != 0)
2138 return (EEXIST);
2139
2140 /*
2141 * Add the interface route associated with the prefix. Before
2142 * installing the route, check if there's the same prefix on another
2143 * interface, and the prefix has already installed the interface route.
2144 * Although such a configuration is expected to be rare, we explicitly
2145 * allow it.
2146 */
2147 ND6_RLOCK();
2148 LIST_FOREACH(opr, &V_nd_prefix, ndpr_entry) {
2149 if (opr == pr)
2150 continue;
2151
2152 if ((opr->ndpr_stateflags & NDPRF_ONLINK) == 0)
2153 continue;
2154
2155 if (!V_rt_add_addr_allfibs &&
2156 opr->ndpr_ifp->if_fib != pr->ndpr_ifp->if_fib)
2157 continue;
2158
2159 if (opr->ndpr_plen == pr->ndpr_plen &&
2160 in6_are_prefix_equal(&pr->ndpr_prefix.sin6_addr,
2161 &opr->ndpr_prefix.sin6_addr, pr->ndpr_plen)) {
2162 ND6_RUNLOCK();
2163 return (0);
2164 }
2165 }
2166 ND6_RUNLOCK();
2167
2168 /*
2169 * We prefer link-local addresses as the associated interface address.
2170 */
2171 /* search for a link-local addr */
2172 NET_EPOCH_ENTER(et);
2173 ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp,
2174 IN6_IFF_NOTREADY | IN6_IFF_ANYCAST);
2175 if (ifa == NULL) {
2176 /* XXX: freebsd does not have ifa_ifwithaf */
2177 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
2178 if (ifa->ifa_addr->sa_family == AF_INET6) {
2179 ifa_ref(ifa);
2180 break;
2181 }
2182 }
2183 /* should we care about ia6_flags? */
2184 }
2185 if (ifa == NULL) {
2186 /*
2187 * This can still happen, when, for example, we receive an RA
2188 * containing a prefix with the L bit set and the A bit clear,
2189 * after removing all IPv6 addresses on the receiving
2190 * interface. This should, of course, be rare though.
2191 */
2192 nd6log((LOG_NOTICE,
2193 "%s: failed to find any ifaddr to add route for a "
2194 "prefix(%s/%d) on %s\n", __func__,
2195 ip6_sprintf(ip6buf, &pr->ndpr_prefix.sin6_addr),
2196 pr->ndpr_plen, if_name(ifp)));
2197 error = 0;
2198 } else {
2199 error = nd6_prefix_onlink_rtrequest(pr, ifa);
2200 ifa_free(ifa);
2201 }
2202 NET_EPOCH_EXIT(et);
2203
2204 return (error);
2205 }
2206
2207 int
nd6_prefix_offlink(struct nd_prefix * pr)2208 nd6_prefix_offlink(struct nd_prefix *pr)
2209 {
2210 int error = 0;
2211 struct ifnet *ifp = pr->ndpr_ifp;
2212 struct nd_prefix *opr;
2213 char ip6buf[INET6_ADDRSTRLEN];
2214 uint64_t genid;
2215 int a_failure;
2216
2217 ND6_ONLINK_LOCK_ASSERT();
2218 ND6_UNLOCK_ASSERT();
2219
2220 if ((pr->ndpr_stateflags & NDPRF_ONLINK) == 0)
2221 return (EEXIST);
2222
2223 struct sockaddr_in6 mask6 = {
2224 .sin6_family = AF_INET6,
2225 .sin6_len = sizeof(struct sockaddr_in6),
2226 .sin6_addr = pr->ndpr_mask,
2227 };
2228 struct sockaddr_in6 *pmask6 = (pr->ndpr_plen != 128) ? &mask6 : NULL;
2229
2230 error = nd6_prefix_rtrequest(ifp->if_fib, RTM_DELETE,
2231 &pr->ndpr_prefix, pmask6, ifp, NULL);
2232
2233 a_failure = 1;
2234 if (error == 0) {
2235 pr->ndpr_stateflags &= ~NDPRF_ONLINK;
2236
2237 /*
2238 * There might be the same prefix on another interface,
2239 * the prefix which could not be on-link just because we have
2240 * the interface route (see comments in nd6_prefix_onlink).
2241 * If there's one, try to make the prefix on-link on the
2242 * interface.
2243 */
2244 ND6_RLOCK();
2245 restart:
2246 LIST_FOREACH(opr, &V_nd_prefix, ndpr_entry) {
2247 /*
2248 * KAME specific: detached prefixes should not be
2249 * on-link.
2250 */
2251 if (opr == pr || (opr->ndpr_stateflags &
2252 (NDPRF_ONLINK | NDPRF_DETACHED)) != 0)
2253 continue;
2254
2255 if (opr->ndpr_plen == pr->ndpr_plen &&
2256 in6_are_prefix_equal(&pr->ndpr_prefix.sin6_addr,
2257 &opr->ndpr_prefix.sin6_addr, pr->ndpr_plen)) {
2258 int e;
2259
2260 genid = V_nd6_list_genid;
2261 ND6_RUNLOCK();
2262 if ((e = nd6_prefix_onlink(opr)) != 0) {
2263 nd6log((LOG_ERR,
2264 "%s: failed to recover a prefix "
2265 "%s/%d from %s to %s (errno=%d)\n",
2266 __func__, ip6_sprintf(ip6buf,
2267 &opr->ndpr_prefix.sin6_addr),
2268 opr->ndpr_plen, if_name(ifp),
2269 if_name(opr->ndpr_ifp), e));
2270 } else
2271 a_failure = 0;
2272 ND6_RLOCK();
2273 if (genid != V_nd6_list_genid)
2274 goto restart;
2275 }
2276 }
2277 ND6_RUNLOCK();
2278 } else {
2279 /* XXX: can we still set the NDPRF_ONLINK flag? */
2280 nd6log((LOG_ERR,
2281 "%s: failed to delete route: %s/%d on %s (errno=%d)\n",
2282 __func__, ip6_sprintf(ip6buf, &pr->ndpr_prefix.sin6_addr),
2283 pr->ndpr_plen, if_name(ifp), error));
2284 }
2285
2286 if (a_failure)
2287 lltable_prefix_free(AF_INET6,
2288 (struct sockaddr *)&pr->ndpr_prefix,
2289 (struct sockaddr *)&mask6, LLE_STATIC);
2290
2291 return (error);
2292 }
2293
2294 /*
2295 * Get a randomized interface identifier for a temporary address
2296 * Based on RFC 8981, Section 3.3.1.
2297 */
2298 static int
in6_get_tmp_ifid(struct in6_aliasreq * ifra)2299 in6_get_tmp_ifid(struct in6_aliasreq *ifra)
2300 {
2301 struct in6_addr *addr;
2302
2303 if(!is_random_seeded()){
2304 return 1;
2305 }
2306
2307 addr = &(ifra->ifra_addr.sin6_addr);
2308 regen:
2309 ifra->ifra_addr.sin6_addr.s6_addr32[2] |=
2310 (arc4random() & ~(ifra->ifra_prefixmask.sin6_addr.s6_addr32[2]));
2311 ifra->ifra_addr.sin6_addr.s6_addr32[3] |=
2312 (arc4random() & ~(ifra->ifra_prefixmask.sin6_addr.s6_addr32[3]));
2313
2314 /*
2315 * Check if generated address is not inappropriate:
2316 *
2317 * - Reserved IPv6 Interface aIdentifers
2318 * (https://www.iana.org/assignments/ipv6-interface-ids/)
2319 */
2320
2321 /* Subnet-router anycast: 0000:0000:0000:0000 */
2322 if (!(addr->s6_addr32[2] | addr->s6_addr32[3]))
2323 goto regen;
2324
2325 /*
2326 * IANA Ethernet block: 0200:5EFF:FE00:0000-0200:5EFF:FE00:5212
2327 * Proxy Mobile IPv6: 0200:5EFF:FE00:5213
2328 * IANA Ethernet block: 0200:5EFF:FE00:5214-0200:5EFF:FEFF:FFFF
2329 */
2330 if (ntohl(addr->s6_addr32[2]) == 0x02005eff &&
2331 (ntohl(addr->s6_addr32[3]) & 0Xff000000) == 0xfe000000)
2332 goto regen;
2333
2334 /* Reserved subnet anycast addresses */
2335 if (ntohl(addr->s6_addr32[2]) == 0xfdffffff &&
2336 ntohl(addr->s6_addr32[3]) >= 0Xffffff80)
2337 goto regen;
2338
2339 return 0;
2340 }
2341
2342 /*
2343 * ia0 - corresponding public address
2344 */
2345 int
in6_tmpifadd(const struct in6_ifaddr * ia0,int forcegen,int delay)2346 in6_tmpifadd(const struct in6_ifaddr *ia0, int forcegen, int delay)
2347 {
2348 struct ifnet *ifp = ia0->ia_ifa.ifa_ifp;
2349 struct in6_ifaddr *newia;
2350 struct in6_aliasreq ifra;
2351 int error;
2352 int trylimit = 3; /* XXX: adhoc value */
2353 int updateflags;
2354 time_t vltime0, pltime0;
2355
2356 in6_prepare_ifra(&ifra, &ia0->ia_addr.sin6_addr,
2357 &ia0->ia_prefixmask.sin6_addr);
2358
2359 ifra.ifra_addr = ia0->ia_addr; /* XXX: do we need this ? */
2360 /* clear the old IFID */
2361 IN6_MASK_ADDR(&ifra.ifra_addr.sin6_addr,
2362 &ifra.ifra_prefixmask.sin6_addr);
2363
2364 again:
2365 if (in6_get_tmp_ifid(&ifra) != 0) {
2366 nd6log((LOG_NOTICE, "%s: failed to find a good random IFID\n",
2367 __func__));
2368 return (EINVAL);
2369 }
2370
2371 /*
2372 * in6_get_tmpifid() quite likely provided a unique interface ID.
2373 * However, we may still have a chance to see collision, because
2374 * there may be a time lag between generation of the ID and generation
2375 * of the address. So, we'll do one more sanity check.
2376 */
2377
2378 if (in6_localip(&ifra.ifra_addr.sin6_addr) != 0) {
2379 if (trylimit-- > 0) {
2380 forcegen = 1;
2381 goto again;
2382 }
2383
2384 /* Give up. Something strange should have happened. */
2385 nd6log((LOG_NOTICE, "%s: failed to find a unique random IFID\n",
2386 __func__));
2387 return (EEXIST);
2388 }
2389
2390 /*
2391 * The Valid Lifetime is the lower of the Valid Lifetime of the
2392 * public address or TEMP_VALID_LIFETIME.
2393 * The Preferred Lifetime is the lower of the Preferred Lifetime
2394 * of the public address or TEMP_PREFERRED_LIFETIME -
2395 * DESYNC_FACTOR.
2396 */
2397 if (ia0->ia6_lifetime.ia6t_vltime != ND6_INFINITE_LIFETIME) {
2398 vltime0 = IFA6_IS_INVALID(ia0) ? 0 :
2399 (ia0->ia6_lifetime.ia6t_vltime -
2400 (time_uptime - ia0->ia6_updatetime));
2401 if (vltime0 > V_ip6_temp_valid_lifetime)
2402 vltime0 = V_ip6_temp_valid_lifetime;
2403 } else
2404 vltime0 = V_ip6_temp_valid_lifetime;
2405 if (ia0->ia6_lifetime.ia6t_pltime != ND6_INFINITE_LIFETIME) {
2406 pltime0 = IFA6_IS_DEPRECATED(ia0) ? 0 :
2407 (ia0->ia6_lifetime.ia6t_pltime -
2408 (time_uptime - ia0->ia6_updatetime));
2409 if (pltime0 > V_ip6_temp_preferred_lifetime - V_ip6_desync_factor){
2410 pltime0 = V_ip6_temp_preferred_lifetime -
2411 V_ip6_desync_factor;
2412 }
2413 } else
2414 pltime0 = V_ip6_temp_preferred_lifetime - V_ip6_desync_factor;
2415 ifra.ifra_lifetime.ia6t_vltime = vltime0;
2416 ifra.ifra_lifetime.ia6t_pltime = pltime0;
2417
2418 /*
2419 * A temporary address is created only if this calculated Preferred
2420 * Lifetime is greater than REGEN_ADVANCE time units.
2421 */
2422 if (ifra.ifra_lifetime.ia6t_pltime <= V_ip6_temp_regen_advance)
2423 return (0);
2424
2425 /* XXX: scope zone ID? */
2426
2427 ifra.ifra_flags |= (IN6_IFF_AUTOCONF|IN6_IFF_TEMPORARY);
2428
2429 /* allocate ifaddr structure, link into chain, etc. */
2430 updateflags = 0;
2431 if (delay)
2432 updateflags |= IN6_IFAUPDATE_DADDELAY;
2433 if ((error = in6_update_ifa(ifp, &ifra, NULL, updateflags)) != 0)
2434 return (error);
2435
2436 newia = in6ifa_ifpwithaddr(ifp, &ifra.ifra_addr.sin6_addr);
2437 if (newia == NULL) { /* XXX: can it happen? */
2438 nd6log((LOG_ERR,
2439 "%s: ifa update succeeded, but we got no ifaddr\n",
2440 __func__));
2441 return (EINVAL); /* XXX */
2442 }
2443 newia->ia6_ndpr = ia0->ia6_ndpr;
2444 newia->ia6_ndpr->ndpr_addrcnt++;
2445 ifa_free(&newia->ia_ifa);
2446
2447 /*
2448 * A newly added address might affect the status of other addresses.
2449 * XXX: when the temporary address is generated with a new public
2450 * address, the onlink check is redundant. However, it would be safe
2451 * to do the check explicitly everywhere a new address is generated,
2452 * and, in fact, we surely need the check when we create a new
2453 * temporary address due to deprecation of an old temporary address.
2454 */
2455 pfxlist_onlink_check();
2456
2457 return (0);
2458 }
2459
2460 static int
rt6_deleteroute(const struct rtentry * rt,const struct nhop_object * nh,void * arg)2461 rt6_deleteroute(const struct rtentry *rt, const struct nhop_object *nh,
2462 void *arg)
2463 {
2464 struct in6_addr *gate = (struct in6_addr *)arg;
2465 int nh_rt_flags;
2466
2467 if (nh->gw_sa.sa_family != AF_INET6)
2468 return (0);
2469
2470 if (!IN6_ARE_ADDR_EQUAL(gate, &nh->gw6_sa.sin6_addr)) {
2471 return (0);
2472 }
2473
2474 /*
2475 * Do not delete a static route.
2476 * XXX: this seems to be a bit ad-hoc. Should we consider the
2477 * 'cloned' bit instead?
2478 */
2479 nh_rt_flags = nhop_get_rtflags(nh);
2480 if ((nh_rt_flags & RTF_STATIC) != 0)
2481 return (0);
2482
2483 /*
2484 * We delete only host route. This means, in particular, we don't
2485 * delete default route.
2486 */
2487 if ((nh_rt_flags & RTF_HOST) == 0)
2488 return (0);
2489
2490 return (1);
2491 #undef SIN6
2492 }
2493
2494 /*
2495 * Delete all the routing table entries that use the specified gateway.
2496 * XXX: this function causes search through all entries of routing table, so
2497 * it shouldn't be called when acting as a router.
2498 */
2499 void
rt6_flush(struct in6_addr * gateway,struct ifnet * ifp)2500 rt6_flush(struct in6_addr *gateway, struct ifnet *ifp)
2501 {
2502
2503 /* We'll care only link-local addresses */
2504 if (!IN6_IS_ADDR_LINKLOCAL(gateway))
2505 return;
2506
2507 /* XXX Do we really need to walk any but the default FIB? */
2508 rib_foreach_table_walk_del(AF_INET6, rt6_deleteroute, (void *)gateway);
2509 }
2510
2511 int
nd6_setdefaultiface(int ifindex)2512 nd6_setdefaultiface(int ifindex)
2513 {
2514
2515 if (V_nd6_defifindex != ifindex) {
2516 V_nd6_defifindex = ifindex;
2517 if (V_nd6_defifindex != 0) {
2518 struct epoch_tracker et;
2519
2520 /*
2521 * XXXGL: this function should use ifnet_byindex_ref!
2522 */
2523 NET_EPOCH_ENTER(et);
2524 V_nd6_defifp = ifnet_byindex(V_nd6_defifindex);
2525 NET_EPOCH_EXIT(et);
2526 if (V_nd6_defifp == NULL)
2527 return (EINVAL);
2528 } else
2529 V_nd6_defifp = NULL;
2530
2531 /*
2532 * Our current implementation assumes one-to-one mapping between
2533 * interfaces and links, so it would be natural to use the
2534 * default interface as the default link.
2535 */
2536 scope6_setdefault(V_nd6_defifp);
2537 }
2538
2539 return (0);
2540 }
2541
2542 bool
nd6_defrouter_list_empty(void)2543 nd6_defrouter_list_empty(void)
2544 {
2545
2546 return (TAILQ_EMPTY(&V_nd6_defrouter));
2547 }
2548
2549 void
nd6_defrouter_timer(void)2550 nd6_defrouter_timer(void)
2551 {
2552 struct nd_defrouter *dr, *ndr;
2553 struct nd6_drhead drq;
2554
2555 TAILQ_INIT(&drq);
2556
2557 ND6_WLOCK();
2558 TAILQ_FOREACH_SAFE(dr, &V_nd6_defrouter, dr_entry, ndr)
2559 if (dr->expire && dr->expire < time_uptime)
2560 defrouter_unlink(dr, &drq);
2561 ND6_WUNLOCK();
2562
2563 while ((dr = TAILQ_FIRST(&drq)) != NULL) {
2564 TAILQ_REMOVE(&drq, dr, dr_entry);
2565 defrouter_del(dr);
2566 }
2567 }
2568
2569 /*
2570 * Nuke default router list entries toward ifp.
2571 * We defer removal of default router list entries that is installed in the
2572 * routing table, in order to keep additional side effects as small as possible.
2573 */
2574 void
nd6_defrouter_purge(struct ifnet * ifp)2575 nd6_defrouter_purge(struct ifnet *ifp)
2576 {
2577 struct nd_defrouter *dr, *ndr;
2578 struct nd6_drhead drq;
2579
2580 TAILQ_INIT(&drq);
2581
2582 ND6_WLOCK();
2583 TAILQ_FOREACH_SAFE(dr, &V_nd6_defrouter, dr_entry, ndr) {
2584 if (dr->installed)
2585 continue;
2586 if (dr->ifp == ifp)
2587 defrouter_unlink(dr, &drq);
2588 }
2589 TAILQ_FOREACH_SAFE(dr, &V_nd6_defrouter, dr_entry, ndr) {
2590 if (!dr->installed)
2591 continue;
2592 if (dr->ifp == ifp)
2593 defrouter_unlink(dr, &drq);
2594 }
2595 ND6_WUNLOCK();
2596
2597 /* Delete the unlinked router objects. */
2598 while ((dr = TAILQ_FIRST(&drq)) != NULL) {
2599 TAILQ_REMOVE(&drq, dr, dr_entry);
2600 defrouter_del(dr);
2601 }
2602 }
2603
2604 void
nd6_defrouter_flush_all(void)2605 nd6_defrouter_flush_all(void)
2606 {
2607 struct nd_defrouter *dr;
2608 struct nd6_drhead drq;
2609
2610 TAILQ_INIT(&drq);
2611
2612 ND6_WLOCK();
2613 while ((dr = TAILQ_FIRST(&V_nd6_defrouter)) != NULL)
2614 defrouter_unlink(dr, &drq);
2615 ND6_WUNLOCK();
2616
2617 while ((dr = TAILQ_FIRST(&drq)) != NULL) {
2618 TAILQ_REMOVE(&drq, dr, dr_entry);
2619 defrouter_del(dr);
2620 }
2621 }
2622
2623 void
nd6_defrouter_init(void)2624 nd6_defrouter_init(void)
2625 {
2626
2627 TAILQ_INIT(&V_nd6_defrouter);
2628 }
2629
2630 static int
nd6_sysctl_drlist(SYSCTL_HANDLER_ARGS)2631 nd6_sysctl_drlist(SYSCTL_HANDLER_ARGS)
2632 {
2633 struct in6_defrouter d;
2634 struct nd_defrouter *dr;
2635 int error;
2636
2637 if (req->newptr != NULL)
2638 return (EPERM);
2639
2640 error = sysctl_wire_old_buffer(req, 0);
2641 if (error != 0)
2642 return (error);
2643
2644 bzero(&d, sizeof(d));
2645 d.rtaddr.sin6_family = AF_INET6;
2646 d.rtaddr.sin6_len = sizeof(d.rtaddr);
2647
2648 ND6_RLOCK();
2649 TAILQ_FOREACH(dr, &V_nd6_defrouter, dr_entry) {
2650 d.rtaddr.sin6_addr = dr->rtaddr;
2651 error = sa6_recoverscope(&d.rtaddr);
2652 if (error != 0)
2653 break;
2654 d.flags = dr->raflags;
2655 d.rtlifetime = dr->rtlifetime;
2656 d.expire = dr->expire + (time_second - time_uptime);
2657 d.if_index = dr->ifp->if_index;
2658 error = SYSCTL_OUT(req, &d, sizeof(d));
2659 if (error != 0)
2660 break;
2661 }
2662 ND6_RUNLOCK();
2663 return (error);
2664 }
2665 SYSCTL_PROC(_net_inet6_icmp6, ICMPV6CTL_ND6_DRLIST, nd6_drlist,
2666 CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE,
2667 NULL, 0, nd6_sysctl_drlist, "S,in6_defrouter",
2668 "NDP default router list");
2669