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