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