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sys/netinet6/nd6_rtr.c
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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 nd6_prefix_onlink(struct nd_prefix *); 86 static int nd6_prefix_offlink(struct nd_prefix *); 87 88 static int rt6_deleteroute(struct radix_node *, void *); 89 90 extern int nd6_recalc_reachtm_interval; 91 92 static struct ifnet *nd6_defifp; 93 int nd6_defifindex; 94 95 int ip6_use_tempaddr = 0; 96 97 int ip6_desync_factor; 98 u_int32_t ip6_temp_preferred_lifetime = DEF_TEMP_PREFERRED_LIFETIME; 99 u_int32_t ip6_temp_valid_lifetime = DEF_TEMP_VALID_LIFETIME; 100 /* 101 * shorter lifetimes for debugging purposes. 102 int ip6_temp_preferred_lifetime = 800; 103 static int ip6_temp_valid_lifetime = 1800; 104 */ 105 int ip6_temp_regen_advance = TEMPADDR_REGEN_ADVANCE; 106 107 /* RTPREF_MEDIUM has to be 0! */ 108 #define RTPREF_HIGH 1 109 #define RTPREF_MEDIUM 0 110 #define RTPREF_LOW (-1) 111 #define RTPREF_RESERVED (-2) 112 #define RTPREF_INVALID (-3) /* internal */ 113 114 /* 115 * Receive Router Solicitation Message - just for routers. 116 * Router solicitation/advertisement is mostly managed by userland program 117 * (rtadvd) so here we have no function like nd6_ra_output(). 118 * 119 * Based on RFC 2461 120 */ 121 void 122 nd6_rs_input(struct mbuf *m, int off, int icmp6len) 123 { 124 struct ifnet *ifp = m->m_pkthdr.rcvif; 125 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 126 struct nd_router_solicit *nd_rs; 127 struct in6_addr saddr6 = ip6->ip6_src; 128 char *lladdr = NULL; 129 int lladdrlen = 0; 130 union nd_opts ndopts; 131 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 132 133 /* If I'm not a router, ignore it. */ 134 if (ip6_accept_rtadv != 0 || ip6_forwarding != 1) 135 goto freeit; 136 137 /* Sanity checks */ 138 if (ip6->ip6_hlim != 255) { 139 nd6log((LOG_ERR, 140 "nd6_rs_input: invalid hlim (%d) from %s to %s on %s\n", 141 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src), 142 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp))); 143 goto bad; 144 } 145 146 /* 147 * Don't update the neighbor cache, if src = ::. 148 * This indicates that the src has no IP address assigned yet. 149 */ 150 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) 151 goto freeit; 152 153 #ifndef PULLDOWN_TEST 154 IP6_EXTHDR_CHECK(m, off, icmp6len,); 155 nd_rs = (struct nd_router_solicit *)((caddr_t)ip6 + off); 156 #else 157 IP6_EXTHDR_GET(nd_rs, struct nd_router_solicit *, m, off, icmp6len); 158 if (nd_rs == NULL) { 159 icmp6stat.icp6s_tooshort++; 160 return; 161 } 162 #endif 163 164 icmp6len -= sizeof(*nd_rs); 165 nd6_option_init(nd_rs + 1, icmp6len, &ndopts); 166 if (nd6_options(&ndopts) < 0) { 167 nd6log((LOG_INFO, 168 "nd6_rs_input: invalid ND option, ignored\n")); 169 /* nd6_options have incremented stats */ 170 goto freeit; 171 } 172 173 if (ndopts.nd_opts_src_lladdr) { 174 lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1); 175 lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3; 176 } 177 178 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 179 nd6log((LOG_INFO, 180 "nd6_rs_input: lladdrlen mismatch for %s " 181 "(if %d, RS packet %d)\n", 182 ip6_sprintf(ip6bufs, &saddr6), 183 ifp->if_addrlen, lladdrlen - 2)); 184 goto bad; 185 } 186 187 nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, ND_ROUTER_SOLICIT, 0); 188 189 freeit: 190 m_freem(m); 191 return; 192 193 bad: 194 icmp6stat.icp6s_badrs++; 195 m_freem(m); 196 } 197 198 /* 199 * Receive Router Advertisement Message. 200 * 201 * Based on RFC 2461 202 * TODO: on-link bit on prefix information 203 * TODO: ND_RA_FLAG_{OTHER,MANAGED} processing 204 */ 205 void 206 nd6_ra_input(struct mbuf *m, int off, int icmp6len) 207 { 208 struct ifnet *ifp = m->m_pkthdr.rcvif; 209 struct nd_ifinfo *ndi = ND_IFINFO(ifp); 210 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 211 struct nd_router_advert *nd_ra; 212 struct in6_addr saddr6 = ip6->ip6_src; 213 int mcast = 0; 214 union nd_opts ndopts; 215 struct nd_defrouter *dr; 216 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 217 218 /* 219 * We only accept RAs only when 220 * the system-wide variable allows the acceptance, and 221 * per-interface variable allows RAs on the receiving interface. 222 */ 223 if (ip6_accept_rtadv == 0) 224 goto freeit; 225 if (!(ndi->flags & ND6_IFF_ACCEPT_RTADV)) 226 goto freeit; 227 228 if (ip6->ip6_hlim != 255) { 229 nd6log((LOG_ERR, 230 "nd6_ra_input: invalid hlim (%d) from %s to %s on %s\n", 231 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src), 232 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp))); 233 goto bad; 234 } 235 236 if (!IN6_IS_ADDR_LINKLOCAL(&saddr6)) { 237 nd6log((LOG_ERR, 238 "nd6_ra_input: src %s is not link-local\n", 239 ip6_sprintf(ip6bufs, &saddr6))); 240 goto bad; 241 } 242 243 #ifndef PULLDOWN_TEST 244 IP6_EXTHDR_CHECK(m, off, icmp6len,); 245 nd_ra = (struct nd_router_advert *)((caddr_t)ip6 + off); 246 #else 247 IP6_EXTHDR_GET(nd_ra, struct nd_router_advert *, m, off, icmp6len); 248 if (nd_ra == NULL) { 249 icmp6stat.icp6s_tooshort++; 250 return; 251 } 252 #endif 253 254 icmp6len -= sizeof(*nd_ra); 255 nd6_option_init(nd_ra + 1, icmp6len, &ndopts); 256 if (nd6_options(&ndopts) < 0) { 257 nd6log((LOG_INFO, 258 "nd6_ra_input: invalid ND option, ignored\n")); 259 /* nd6_options have incremented stats */ 260 goto freeit; 261 } 262 263 { 264 struct nd_defrouter dr0; 265 u_int32_t advreachable = nd_ra->nd_ra_reachable; 266 267 /* remember if this is a multicasted advertisement */ 268 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) 269 mcast = 1; 270 271 bzero(&dr0, sizeof(dr0)); 272 dr0.rtaddr = saddr6; 273 dr0.flags = nd_ra->nd_ra_flags_reserved; 274 dr0.rtlifetime = ntohs(nd_ra->nd_ra_router_lifetime); 275 dr0.expire = time_second + dr0.rtlifetime; 276 dr0.ifp = ifp; 277 /* unspecified or not? (RFC 2461 6.3.4) */ 278 if (advreachable) { 279 advreachable = ntohl(advreachable); 280 if (advreachable <= MAX_REACHABLE_TIME && 281 ndi->basereachable != advreachable) { 282 ndi->basereachable = advreachable; 283 ndi->reachable = ND_COMPUTE_RTIME(ndi->basereachable); 284 ndi->recalctm = nd6_recalc_reachtm_interval; /* reset */ 285 } 286 } 287 if (nd_ra->nd_ra_retransmit) 288 ndi->retrans = ntohl(nd_ra->nd_ra_retransmit); 289 if (nd_ra->nd_ra_curhoplimit) 290 ndi->chlim = nd_ra->nd_ra_curhoplimit; 291 dr = defrtrlist_update(&dr0); 292 } 293 294 /* 295 * prefix 296 */ 297 if (ndopts.nd_opts_pi) { 298 struct nd_opt_hdr *pt; 299 struct nd_opt_prefix_info *pi = NULL; 300 struct nd_prefixctl pr; 301 302 for (pt = (struct nd_opt_hdr *)ndopts.nd_opts_pi; 303 pt <= (struct nd_opt_hdr *)ndopts.nd_opts_pi_end; 304 pt = (struct nd_opt_hdr *)((caddr_t)pt + 305 (pt->nd_opt_len << 3))) { 306 if (pt->nd_opt_type != ND_OPT_PREFIX_INFORMATION) 307 continue; 308 pi = (struct nd_opt_prefix_info *)pt; 309 310 if (pi->nd_opt_pi_len != 4) { 311 nd6log((LOG_INFO, 312 "nd6_ra_input: invalid option " 313 "len %d for prefix information option, " 314 "ignored\n", pi->nd_opt_pi_len)); 315 continue; 316 } 317 318 if (128 < pi->nd_opt_pi_prefix_len) { 319 nd6log((LOG_INFO, 320 "nd6_ra_input: invalid prefix " 321 "len %d for prefix information option, " 322 "ignored\n", pi->nd_opt_pi_prefix_len)); 323 continue; 324 } 325 326 if (IN6_IS_ADDR_MULTICAST(&pi->nd_opt_pi_prefix) 327 || IN6_IS_ADDR_LINKLOCAL(&pi->nd_opt_pi_prefix)) { 328 nd6log((LOG_INFO, 329 "nd6_ra_input: invalid prefix " 330 "%s, ignored\n", 331 ip6_sprintf(ip6bufs, 332 &pi->nd_opt_pi_prefix))); 333 continue; 334 } 335 336 bzero(&pr, sizeof(pr)); 337 pr.ndpr_prefix.sin6_family = AF_INET6; 338 pr.ndpr_prefix.sin6_len = sizeof(pr.ndpr_prefix); 339 pr.ndpr_prefix.sin6_addr = pi->nd_opt_pi_prefix; 340 pr.ndpr_ifp = (struct ifnet *)m->m_pkthdr.rcvif; 341 342 pr.ndpr_raf_onlink = (pi->nd_opt_pi_flags_reserved & 343 ND_OPT_PI_FLAG_ONLINK) ? 1 : 0; 344 pr.ndpr_raf_auto = (pi->nd_opt_pi_flags_reserved & 345 ND_OPT_PI_FLAG_AUTO) ? 1 : 0; 346 pr.ndpr_plen = pi->nd_opt_pi_prefix_len; 347 pr.ndpr_vltime = ntohl(pi->nd_opt_pi_valid_time); 348 pr.ndpr_pltime = ntohl(pi->nd_opt_pi_preferred_time); 349 (void)prelist_update(&pr, dr, m, mcast); 350 } 351 } 352 353 /* 354 * MTU 355 */ 356 if (ndopts.nd_opts_mtu && ndopts.nd_opts_mtu->nd_opt_mtu_len == 1) { 357 u_long mtu; 358 u_long maxmtu; 359 360 mtu = (u_long)ntohl(ndopts.nd_opts_mtu->nd_opt_mtu_mtu); 361 362 /* lower bound */ 363 if (mtu < IPV6_MMTU) { 364 nd6log((LOG_INFO, "nd6_ra_input: bogus mtu option " 365 "mtu=%lu sent from %s, ignoring\n", 366 mtu, ip6_sprintf(ip6bufs, &ip6->ip6_src))); 367 goto skip; 368 } 369 370 /* upper bound */ 371 maxmtu = (ndi->maxmtu && ndi->maxmtu < ifp->if_mtu) 372 ? ndi->maxmtu : ifp->if_mtu; 373 if (mtu <= maxmtu) { 374 int change = (ndi->linkmtu != mtu); 375 376 ndi->linkmtu = mtu; 377 if (change) /* in6_maxmtu may change */ 378 in6_setmaxmtu(); 379 } else { 380 nd6log((LOG_INFO, "nd6_ra_input: bogus mtu " 381 "mtu=%lu sent from %s; " 382 "exceeds maxmtu %lu, ignoring\n", 383 mtu, ip6_sprintf(ip6bufs, &ip6->ip6_src), maxmtu)); 384 } 385 } 386 387 skip: 388 389 /* 390 * Source link layer address 391 */ 392 { 393 char *lladdr = NULL; 394 int lladdrlen = 0; 395 396 if (ndopts.nd_opts_src_lladdr) { 397 lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1); 398 lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3; 399 } 400 401 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 402 nd6log((LOG_INFO, 403 "nd6_ra_input: lladdrlen mismatch for %s " 404 "(if %d, RA packet %d)\n", ip6_sprintf(ip6bufs, &saddr6), 405 ifp->if_addrlen, lladdrlen - 2)); 406 goto bad; 407 } 408 409 nd6_cache_lladdr(ifp, &saddr6, lladdr, 410 lladdrlen, ND_ROUTER_ADVERT, 0); 411 412 /* 413 * Installing a link-layer address might change the state of the 414 * router's neighbor cache, which might also affect our on-link 415 * detection of adveritsed prefixes. 416 */ 417 pfxlist_onlink_check(); 418 } 419 420 freeit: 421 m_freem(m); 422 return; 423 424 bad: 425 icmp6stat.icp6s_badra++; 426 m_freem(m); 427 } 428 429 /* 430 * default router list proccessing sub routines 431 */ 432 433 /* tell the change to user processes watching the routing socket. */ 434 static void 435 nd6_rtmsg(int cmd, struct rtentry *rt) 436 { 437 struct rt_addrinfo info; 438 439 bzero((caddr_t)&info, sizeof(info)); 440 info.rti_info[RTAX_DST] = rt_key(rt); 441 info.rti_info[RTAX_GATEWAY] = rt->rt_gateway; 442 info.rti_info[RTAX_NETMASK] = rt_mask(rt); 443 if (rt->rt_ifp) { 444 info.rti_info[RTAX_IFP] = 445 TAILQ_FIRST(&rt->rt_ifp->if_addrlist)->ifa_addr; 446 info.rti_info[RTAX_IFA] = rt->rt_ifa->ifa_addr; 447 } 448 449 rt_missmsg(cmd, &info, rt->rt_flags, 0); 450 } 451 452 static void 453 defrouter_addreq(struct nd_defrouter *new) 454 { 455 struct sockaddr_in6 def, mask, gate; 456 struct rtentry *newrt = NULL; 457 int s; 458 int error; 459 460 bzero(&def, sizeof(def)); 461 bzero(&mask, sizeof(mask)); 462 bzero(&gate, sizeof(gate)); 463 464 def.sin6_len = mask.sin6_len = gate.sin6_len = 465 sizeof(struct sockaddr_in6); 466 def.sin6_family = gate.sin6_family = AF_INET6; 467 gate.sin6_addr = new->rtaddr; 468 469 s = splnet(); 470 error = rtrequest(RTM_ADD, (struct sockaddr *)&def, 471 (struct sockaddr *)&gate, (struct sockaddr *)&mask, 472 RTF_GATEWAY, &newrt); 473 if (newrt) { 474 RT_LOCK(newrt); 475 nd6_rtmsg(RTM_ADD, newrt); /* tell user process */ 476 RT_REMREF(newrt); 477 RT_UNLOCK(newrt); 478 } 479 if (error == 0) 480 new->installed = 1; 481 splx(s); 482 return; 483 } 484 485 struct nd_defrouter * 486 defrouter_lookup(struct in6_addr *addr, struct ifnet *ifp) 487 { 488 struct nd_defrouter *dr; 489 490 for (dr = TAILQ_FIRST(&nd_defrouter); dr; 491 dr = TAILQ_NEXT(dr, dr_entry)) { 492 if (dr->ifp == ifp && IN6_ARE_ADDR_EQUAL(addr, &dr->rtaddr)) 493 return (dr); 494 } 495 496 return (NULL); /* search failed */ 497 } 498 499 /* 500 * Remove the default route for a given router. 501 * This is just a subroutine function for defrouter_select(), and should 502 * not be called from anywhere else. 503 */ 504 static void 505 defrouter_delreq(struct nd_defrouter *dr) 506 { 507 struct sockaddr_in6 def, mask, gate; 508 struct rtentry *oldrt = NULL; 509 510 bzero(&def, sizeof(def)); 511 bzero(&mask, sizeof(mask)); 512 bzero(&gate, sizeof(gate)); 513 514 def.sin6_len = mask.sin6_len = gate.sin6_len = 515 sizeof(struct sockaddr_in6); 516 def.sin6_family = gate.sin6_family = AF_INET6; 517 gate.sin6_addr = dr->rtaddr; 518 519 rtrequest(RTM_DELETE, (struct sockaddr *)&def, 520 (struct sockaddr *)&gate, 521 (struct sockaddr *)&mask, RTF_GATEWAY, &oldrt); 522 if (oldrt) { 523 nd6_rtmsg(RTM_DELETE, oldrt); 524 RTFREE(oldrt); 525 } 526 527 dr->installed = 0; 528 } 529 530 /* 531 * remove all default routes from default router list 532 */ 533 void 534 defrouter_reset(void) 535 { 536 struct nd_defrouter *dr; 537 538 for (dr = TAILQ_FIRST(&nd_defrouter); dr; 539 dr = TAILQ_NEXT(dr, dr_entry)) 540 defrouter_delreq(dr); 541 542 /* 543 * XXX should we also nuke any default routers in the kernel, by 544 * going through them by rtalloc1()? 545 */ 546 } 547 548 void 549 defrtrlist_del(struct nd_defrouter *dr) 550 { 551 struct nd_defrouter *deldr = NULL; 552 struct nd_prefix *pr; 553 554 /* 555 * Flush all the routing table entries that use the router 556 * as a next hop. 557 */ 558 if (!ip6_forwarding && ip6_accept_rtadv) /* XXX: better condition? */ 559 rt6_flush(&dr->rtaddr, dr->ifp); 560 561 if (dr->installed) { 562 deldr = dr; 563 defrouter_delreq(dr); 564 } 565 TAILQ_REMOVE(&nd_defrouter, dr, dr_entry); 566 567 /* 568 * Also delete all the pointers to the router in each prefix lists. 569 */ 570 for (pr = nd_prefix.lh_first; pr; pr = pr->ndpr_next) { 571 struct nd_pfxrouter *pfxrtr; 572 if ((pfxrtr = pfxrtr_lookup(pr, dr)) != NULL) 573 pfxrtr_del(pfxrtr); 574 } 575 pfxlist_onlink_check(); 576 577 /* 578 * If the router is the primary one, choose a new one. 579 * Note that defrouter_select() will remove the current gateway 580 * from the routing table. 581 */ 582 if (deldr) 583 defrouter_select(); 584 585 free(dr, M_IP6NDP); 586 } 587 588 /* 589 * Default Router Selection according to Section 6.3.6 of RFC 2461 and 590 * draft-ietf-ipngwg-router-selection: 591 * 1) Routers that are reachable or probably reachable should be preferred. 592 * If we have more than one (probably) reachable router, prefer ones 593 * with the highest router preference. 594 * 2) When no routers on the list are known to be reachable or 595 * probably reachable, routers SHOULD be selected in a round-robin 596 * fashion, regardless of router preference values. 597 * 3) If the Default Router List is empty, assume that all 598 * destinations are on-link. 599 * 600 * We assume nd_defrouter is sorted by router preference value. 601 * Since the code below covers both with and without router preference cases, 602 * we do not need to classify the cases by ifdef. 603 * 604 * At this moment, we do not try to install more than one default router, 605 * even when the multipath routing is available, because we're not sure about 606 * the benefits for stub hosts comparing to the risk of making the code 607 * complicated and the possibility of introducing bugs. 608 */ 609 void 610 defrouter_select(void) 611 { 612 int s = splnet(); 613 struct nd_defrouter *dr, *selected_dr = NULL, *installed_dr = NULL; 614 struct rtentry *rt = NULL; 615 struct llinfo_nd6 *ln = NULL; 616 617 /* 618 * This function should be called only when acting as an autoconfigured 619 * host. Although the remaining part of this function is not effective 620 * if the node is not an autoconfigured host, we explicitly exclude 621 * such cases here for safety. 622 */ 623 if (ip6_forwarding || !ip6_accept_rtadv) { 624 nd6log((LOG_WARNING, 625 "defrouter_select: called unexpectedly (forwarding=%d, " 626 "accept_rtadv=%d)\n", ip6_forwarding, ip6_accept_rtadv)); 627 splx(s); 628 return; 629 } 630 631 /* 632 * Let's handle easy case (3) first: 633 * If default router list is empty, there's nothing to be done. 634 */ 635 if (!TAILQ_FIRST(&nd_defrouter)) { 636 splx(s); 637 return; 638 } 639 640 /* 641 * Search for a (probably) reachable router from the list. 642 * We just pick up the first reachable one (if any), assuming that 643 * the ordering rule of the list described in defrtrlist_update(). 644 */ 645 for (dr = TAILQ_FIRST(&nd_defrouter); dr; 646 dr = TAILQ_NEXT(dr, dr_entry)) { 647 if (selected_dr == NULL && 648 (rt = nd6_lookup(&dr->rtaddr, 0, dr->ifp)) && 649 (ln = (struct llinfo_nd6 *)rt->rt_llinfo) && 650 ND6_IS_LLINFO_PROBREACH(ln)) { 651 selected_dr = dr; 652 } 653 654 if (dr->installed && installed_dr == NULL) 655 installed_dr = dr; 656 else if (dr->installed && installed_dr) { 657 /* this should not happen. warn for diagnosis. */ 658 log(LOG_ERR, "defrouter_select: more than one router" 659 " is installed\n"); 660 } 661 } 662 /* 663 * If none of the default routers was found to be reachable, 664 * round-robin the list regardless of preference. 665 * Otherwise, if we have an installed router, check if the selected 666 * (reachable) router should really be preferred to the installed one. 667 * We only prefer the new router when the old one is not reachable 668 * or when the new one has a really higher preference value. 669 */ 670 if (selected_dr == NULL) { 671 if (installed_dr == NULL || !TAILQ_NEXT(installed_dr, dr_entry)) 672 selected_dr = TAILQ_FIRST(&nd_defrouter); 673 else 674 selected_dr = TAILQ_NEXT(installed_dr, dr_entry); 675 } else if (installed_dr && 676 (rt = nd6_lookup(&installed_dr->rtaddr, 0, installed_dr->ifp)) && 677 (ln = (struct llinfo_nd6 *)rt->rt_llinfo) && 678 ND6_IS_LLINFO_PROBREACH(ln) && 679 rtpref(selected_dr) <= rtpref(installed_dr)) { 680 selected_dr = installed_dr; 681 } 682 683 /* 684 * If the selected router is different than the installed one, 685 * remove the installed router and install the selected one. 686 * Note that the selected router is never NULL here. 687 */ 688 if (installed_dr != selected_dr) { 689 if (installed_dr) 690 defrouter_delreq(installed_dr); 691 defrouter_addreq(selected_dr); 692 } 693 694 splx(s); 695 return; 696 } 697 698 /* 699 * for default router selection 700 * regards router-preference field as a 2-bit signed integer 701 */ 702 static int 703 rtpref(struct nd_defrouter *dr) 704 { 705 switch (dr->flags & ND_RA_FLAG_RTPREF_MASK) { 706 case ND_RA_FLAG_RTPREF_HIGH: 707 return (RTPREF_HIGH); 708 case ND_RA_FLAG_RTPREF_MEDIUM: 709 case ND_RA_FLAG_RTPREF_RSV: 710 return (RTPREF_MEDIUM); 711 case ND_RA_FLAG_RTPREF_LOW: 712 return (RTPREF_LOW); 713 default: 714 /* 715 * This case should never happen. If it did, it would mean a 716 * serious bug of kernel internal. We thus always bark here. 717 * Or, can we even panic? 718 */ 719 log(LOG_ERR, "rtpref: impossible RA flag %x\n", dr->flags); 720 return (RTPREF_INVALID); 721 } 722 /* NOTREACHED */ 723 } 724 725 static struct nd_defrouter * 726 defrtrlist_update(struct nd_defrouter *new) 727 { 728 struct nd_defrouter *dr, *n; 729 int s = splnet(); 730 731 if ((dr = defrouter_lookup(&new->rtaddr, new->ifp)) != NULL) { 732 /* entry exists */ 733 if (new->rtlifetime == 0) { 734 defrtrlist_del(dr); 735 dr = NULL; 736 } else { 737 int oldpref = rtpref(dr); 738 739 /* override */ 740 dr->flags = new->flags; /* xxx flag check */ 741 dr->rtlifetime = new->rtlifetime; 742 dr->expire = new->expire; 743 744 /* 745 * If the preference does not change, there's no need 746 * to sort the entries. 747 */ 748 if (rtpref(new) == oldpref) { 749 splx(s); 750 return (dr); 751 } 752 753 /* 754 * preferred router may be changed, so relocate 755 * this router. 756 * XXX: calling TAILQ_REMOVE directly is a bad manner. 757 * However, since defrtrlist_del() has many side 758 * effects, we intentionally do so here. 759 * defrouter_select() below will handle routing 760 * changes later. 761 */ 762 TAILQ_REMOVE(&nd_defrouter, dr, dr_entry); 763 n = dr; 764 goto insert; 765 } 766 splx(s); 767 return (dr); 768 } 769 770 /* entry does not exist */ 771 if (new->rtlifetime == 0) { 772 splx(s); 773 return (NULL); 774 } 775 776 n = (struct nd_defrouter *)malloc(sizeof(*n), M_IP6NDP, M_NOWAIT); 777 if (n == NULL) { 778 splx(s); 779 return (NULL); 780 } 781 bzero(n, sizeof(*n)); 782 *n = *new; 783 784 insert: 785 /* 786 * Insert the new router in the Default Router List; 787 * The Default Router List should be in the descending order 788 * of router-preferece. Routers with the same preference are 789 * sorted in the arriving time order. 790 */ 791 792 /* insert at the end of the group */ 793 for (dr = TAILQ_FIRST(&nd_defrouter); dr; 794 dr = TAILQ_NEXT(dr, dr_entry)) { 795 if (rtpref(n) > rtpref(dr)) 796 break; 797 } 798 if (dr) 799 TAILQ_INSERT_BEFORE(dr, n, dr_entry); 800 else 801 TAILQ_INSERT_TAIL(&nd_defrouter, n, dr_entry); 802 803 defrouter_select(); 804 805 splx(s); 806 807 return (n); 808 } 809 810 static struct nd_pfxrouter * 811 pfxrtr_lookup(struct nd_prefix *pr, struct nd_defrouter *dr) 812 { 813 struct nd_pfxrouter *search; 814 815 for (search = pr->ndpr_advrtrs.lh_first; search; search = search->pfr_next) { 816 if (search->router == dr) 817 break; 818 } 819 820 return (search); 821 } 822 823 static void 824 pfxrtr_add(struct nd_prefix *pr, struct nd_defrouter *dr) 825 { 826 struct nd_pfxrouter *new; 827 828 new = (struct nd_pfxrouter *)malloc(sizeof(*new), M_IP6NDP, M_NOWAIT); 829 if (new == NULL) 830 return; 831 bzero(new, sizeof(*new)); 832 new->router = dr; 833 834 LIST_INSERT_HEAD(&pr->ndpr_advrtrs, new, pfr_entry); 835 836 pfxlist_onlink_check(); 837 } 838 839 static void 840 pfxrtr_del(struct nd_pfxrouter *pfr) 841 { 842 LIST_REMOVE(pfr, pfr_entry); 843 free(pfr, M_IP6NDP); 844 } 845 846 struct nd_prefix * 847 nd6_prefix_lookup(struct nd_prefixctl *key) 848 { 849 struct nd_prefix *search; 850 851 for (search = nd_prefix.lh_first; search; search = search->ndpr_next) { 852 if (key->ndpr_ifp == search->ndpr_ifp && 853 key->ndpr_plen == search->ndpr_plen && 854 in6_are_prefix_equal(&key->ndpr_prefix.sin6_addr, 855 &search->ndpr_prefix.sin6_addr, key->ndpr_plen)) { 856 break; 857 } 858 } 859 860 return (search); 861 } 862 863 int 864 nd6_prelist_add(struct nd_prefixctl *pr, struct nd_defrouter *dr, 865 struct nd_prefix **newp) 866 { 867 struct nd_prefix *new = NULL; 868 int error = 0; 869 int i, s; 870 char ip6buf[INET6_ADDRSTRLEN]; 871 872 new = (struct nd_prefix *)malloc(sizeof(*new), M_IP6NDP, M_NOWAIT); 873 if (new == NULL) 874 return(ENOMEM); 875 bzero(new, sizeof(*new)); 876 new->ndpr_ifp = pr->ndpr_ifp; 877 new->ndpr_prefix = pr->ndpr_prefix; 878 new->ndpr_plen = pr->ndpr_plen; 879 new->ndpr_vltime = pr->ndpr_vltime; 880 new->ndpr_pltime = pr->ndpr_pltime; 881 new->ndpr_flags = pr->ndpr_flags; 882 if ((error = in6_init_prefix_ltimes(new)) != 0) { 883 free(new, M_IP6NDP); 884 return(error); 885 } 886 new->ndpr_lastupdate = time_second; 887 if (newp != NULL) 888 *newp = new; 889 890 /* initialization */ 891 LIST_INIT(&new->ndpr_advrtrs); 892 in6_prefixlen2mask(&new->ndpr_mask, new->ndpr_plen); 893 /* make prefix in the canonical form */ 894 for (i = 0; i < 4; i++) 895 new->ndpr_prefix.sin6_addr.s6_addr32[i] &= 896 new->ndpr_mask.s6_addr32[i]; 897 898 s = splnet(); 899 /* link ndpr_entry to nd_prefix list */ 900 LIST_INSERT_HEAD(&nd_prefix, new, ndpr_entry); 901 splx(s); 902 903 /* ND_OPT_PI_FLAG_ONLINK processing */ 904 if (new->ndpr_raf_onlink) { 905 int e; 906 907 if ((e = nd6_prefix_onlink(new)) != 0) { 908 nd6log((LOG_ERR, "nd6_prelist_add: failed to make " 909 "the prefix %s/%d on-link on %s (errno=%d)\n", 910 ip6_sprintf(ip6buf, &pr->ndpr_prefix.sin6_addr), 911 pr->ndpr_plen, if_name(pr->ndpr_ifp), e)); 912 /* proceed anyway. XXX: is it correct? */ 913 } 914 } 915 916 if (dr) 917 pfxrtr_add(new, dr); 918 919 return 0; 920 } 921 922 void 923 prelist_remove(struct nd_prefix *pr) 924 { 925 struct nd_pfxrouter *pfr, *next; 926 int e, s; 927 char ip6buf[INET6_ADDRSTRLEN]; 928 929 /* make sure to invalidate the prefix until it is really freed. */ 930 pr->ndpr_vltime = 0; 931 pr->ndpr_pltime = 0; 932 933 /* 934 * Though these flags are now meaningless, we'd rather keep the value 935 * of pr->ndpr_raf_onlink and pr->ndpr_raf_auto not to confuse users 936 * when executing "ndp -p". 937 */ 938 939 if ((pr->ndpr_stateflags & NDPRF_ONLINK) != 0 && 940 (e = nd6_prefix_offlink(pr)) != 0) { 941 nd6log((LOG_ERR, "prelist_remove: failed to make %s/%d offlink " 942 "on %s, errno=%d\n", 943 ip6_sprintf(ip6buf, &pr->ndpr_prefix.sin6_addr), 944 pr->ndpr_plen, if_name(pr->ndpr_ifp), e)); 945 /* what should we do? */ 946 } 947 948 if (pr->ndpr_refcnt > 0) 949 return; /* notice here? */ 950 951 s = splnet(); 952 953 /* unlink ndpr_entry from nd_prefix list */ 954 LIST_REMOVE(pr, ndpr_entry); 955 956 /* free list of routers that adversed the prefix */ 957 for (pfr = pr->ndpr_advrtrs.lh_first; pfr; pfr = next) { 958 next = pfr->pfr_next; 959 960 free(pfr, M_IP6NDP); 961 } 962 splx(s); 963 964 free(pr, M_IP6NDP); 965 966 pfxlist_onlink_check(); 967 } 968 969 /* 970 * dr - may be NULL 971 */ 972 973 static int 974 prelist_update(struct nd_prefixctl *new, struct nd_defrouter *dr, 975 struct mbuf *m, int mcast) 976 { 977 struct in6_ifaddr *ia6 = NULL, *ia6_match = NULL; 978 struct ifaddr *ifa; 979 struct ifnet *ifp = new->ndpr_ifp; 980 struct nd_prefix *pr; 981 int s = splnet(); 982 int error = 0; 983 int newprefix = 0; 984 int auth; 985 struct in6_addrlifetime lt6_tmp; 986 char ip6buf[INET6_ADDRSTRLEN]; 987 988 auth = 0; 989 if (m) { 990 /* 991 * Authenticity for NA consists authentication for 992 * both IP header and IP datagrams, doesn't it ? 993 */ 994 #if defined(M_AUTHIPHDR) && defined(M_AUTHIPDGM) 995 auth = ((m->m_flags & M_AUTHIPHDR) && 996 (m->m_flags & M_AUTHIPDGM)); 997 #endif 998 } 999 1000 if ((pr = nd6_prefix_lookup(new)) != NULL) { 1001 /* 1002 * nd6_prefix_lookup() ensures that pr and new have the same 1003 * prefix on a same interface. 1004 */ 1005 1006 /* 1007 * Update prefix information. Note that the on-link (L) bit 1008 * and the autonomous (A) bit should NOT be changed from 1 1009 * to 0. 1010 */ 1011 if (new->ndpr_raf_onlink == 1) 1012 pr->ndpr_raf_onlink = 1; 1013 if (new->ndpr_raf_auto == 1) 1014 pr->ndpr_raf_auto = 1; 1015 if (new->ndpr_raf_onlink) { 1016 pr->ndpr_vltime = new->ndpr_vltime; 1017 pr->ndpr_pltime = new->ndpr_pltime; 1018 (void)in6_init_prefix_ltimes(pr); /* XXX error case? */ 1019 pr->ndpr_lastupdate = time_second; 1020 } 1021 1022 if (new->ndpr_raf_onlink && 1023 (pr->ndpr_stateflags & NDPRF_ONLINK) == 0) { 1024 int e; 1025 1026 if ((e = nd6_prefix_onlink(pr)) != 0) { 1027 nd6log((LOG_ERR, 1028 "prelist_update: failed to make " 1029 "the prefix %s/%d on-link on %s " 1030 "(errno=%d)\n", 1031 ip6_sprintf(ip6buf, 1032 &pr->ndpr_prefix.sin6_addr), 1033 pr->ndpr_plen, if_name(pr->ndpr_ifp), e)); 1034 /* proceed anyway. XXX: is it correct? */ 1035 } 1036 } 1037 1038 if (dr && pfxrtr_lookup(pr, dr) == NULL) 1039 pfxrtr_add(pr, dr); 1040 } else { 1041 struct nd_prefix *newpr = NULL; 1042 1043 newprefix = 1; 1044 1045 if (new->ndpr_vltime == 0) 1046 goto end; 1047 if (new->ndpr_raf_onlink == 0 && new->ndpr_raf_auto == 0) 1048 goto end; 1049 1050 error = nd6_prelist_add(new, dr, &newpr); 1051 if (error != 0 || newpr == NULL) { 1052 nd6log((LOG_NOTICE, "prelist_update: " 1053 "nd6_prelist_add failed for %s/%d on %s " 1054 "errno=%d, returnpr=%p\n", 1055 ip6_sprintf(ip6buf, &new->ndpr_prefix.sin6_addr), 1056 new->ndpr_plen, if_name(new->ndpr_ifp), 1057 error, newpr)); 1058 goto end; /* we should just give up in this case. */ 1059 } 1060 1061 /* 1062 * XXX: from the ND point of view, we can ignore a prefix 1063 * with the on-link bit being zero. However, we need a 1064 * prefix structure for references from autoconfigured 1065 * addresses. Thus, we explicitly make sure that the prefix 1066 * itself expires now. 1067 */ 1068 if (newpr->ndpr_raf_onlink == 0) { 1069 newpr->ndpr_vltime = 0; 1070 newpr->ndpr_pltime = 0; 1071 in6_init_prefix_ltimes(newpr); 1072 } 1073 1074 pr = newpr; 1075 } 1076 1077 /* 1078 * Address autoconfiguration based on Section 5.5.3 of RFC 2462. 1079 * Note that pr must be non NULL at this point. 1080 */ 1081 1082 /* 5.5.3 (a). Ignore the prefix without the A bit set. */ 1083 if (!new->ndpr_raf_auto) 1084 goto end; 1085 1086 /* 1087 * 5.5.3 (b). the link-local prefix should have been ignored in 1088 * nd6_ra_input. 1089 */ 1090 1091 /* 5.5.3 (c). Consistency check on lifetimes: pltime <= vltime. */ 1092 if (new->ndpr_pltime > new->ndpr_vltime) { 1093 error = EINVAL; /* XXX: won't be used */ 1094 goto end; 1095 } 1096 1097 /* 1098 * 5.5.3 (d). If the prefix advertised is not equal to the prefix of 1099 * an address configured by stateless autoconfiguration already in the 1100 * list of addresses associated with the interface, and the Valid 1101 * Lifetime is not 0, form an address. We first check if we have 1102 * a matching prefix. 1103 * Note: we apply a clarification in rfc2462bis-02 here. We only 1104 * consider autoconfigured addresses while RFC2462 simply said 1105 * "address". 1106 */ 1107 TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) { 1108 struct in6_ifaddr *ifa6; 1109 u_int32_t remaininglifetime; 1110 1111 if (ifa->ifa_addr->sa_family != AF_INET6) 1112 continue; 1113 1114 ifa6 = (struct in6_ifaddr *)ifa; 1115 1116 /* 1117 * We only consider autoconfigured addresses as per rfc2462bis. 1118 */ 1119 if (!(ifa6->ia6_flags & IN6_IFF_AUTOCONF)) 1120 continue; 1121 1122 /* 1123 * Spec is not clear here, but I believe we should concentrate 1124 * on unicast (i.e. not anycast) addresses. 1125 * XXX: other ia6_flags? detached or duplicated? 1126 */ 1127 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0) 1128 continue; 1129 1130 /* 1131 * Ignore the address if it is not associated with a prefix 1132 * or is associated with a prefix that is different from this 1133 * one. (pr is never NULL here) 1134 */ 1135 if (ifa6->ia6_ndpr != pr) 1136 continue; 1137 1138 if (ia6_match == NULL) /* remember the first one */ 1139 ia6_match = ifa6; 1140 1141 /* 1142 * An already autoconfigured address matched. Now that we 1143 * are sure there is at least one matched address, we can 1144 * proceed to 5.5.3. (e): update the lifetimes according to the 1145 * "two hours" rule and the privacy extension. 1146 * We apply some clarifications in rfc2462bis: 1147 * - use remaininglifetime instead of storedlifetime as a 1148 * variable name 1149 * - remove the dead code in the "two-hour" rule 1150 */ 1151 #define TWOHOUR (120*60) 1152 lt6_tmp = ifa6->ia6_lifetime; 1153 1154 if (lt6_tmp.ia6t_vltime == ND6_INFINITE_LIFETIME) 1155 remaininglifetime = ND6_INFINITE_LIFETIME; 1156 else if (time_second - ifa6->ia6_updatetime > 1157 lt6_tmp.ia6t_vltime) { 1158 /* 1159 * The case of "invalid" address. We should usually 1160 * not see this case. 1161 */ 1162 remaininglifetime = 0; 1163 } else 1164 remaininglifetime = lt6_tmp.ia6t_vltime - 1165 (time_second - ifa6->ia6_updatetime); 1166 1167 /* when not updating, keep the current stored lifetime. */ 1168 lt6_tmp.ia6t_vltime = remaininglifetime; 1169 1170 if (TWOHOUR < new->ndpr_vltime || 1171 remaininglifetime < new->ndpr_vltime) { 1172 lt6_tmp.ia6t_vltime = new->ndpr_vltime; 1173 } else if (remaininglifetime <= TWOHOUR) { 1174 if (auth) { 1175 lt6_tmp.ia6t_vltime = new->ndpr_vltime; 1176 } 1177 } else { 1178 /* 1179 * new->ndpr_vltime <= TWOHOUR && 1180 * TWOHOUR < remaininglifetime 1181 */ 1182 lt6_tmp.ia6t_vltime = TWOHOUR; 1183 } 1184 1185 /* The 2 hour rule is not imposed for preferred lifetime. */ 1186 lt6_tmp.ia6t_pltime = new->ndpr_pltime; 1187 1188 in6_init_address_ltimes(pr, <6_tmp); 1189 1190 /* 1191 * We need to treat lifetimes for temporary addresses 1192 * differently, according to 1193 * draft-ietf-ipv6-privacy-addrs-v2-01.txt 3.3 (1); 1194 * we only update the lifetimes when they are in the maximum 1195 * intervals. 1196 */ 1197 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0) { 1198 u_int32_t maxvltime, maxpltime; 1199 1200 if (ip6_temp_valid_lifetime > 1201 (u_int32_t)((time_second - ifa6->ia6_createtime) + 1202 ip6_desync_factor)) { 1203 maxvltime = ip6_temp_valid_lifetime - 1204 (time_second - ifa6->ia6_createtime) - 1205 ip6_desync_factor; 1206 } else 1207 maxvltime = 0; 1208 if (ip6_temp_preferred_lifetime > 1209 (u_int32_t)((time_second - ifa6->ia6_createtime) + 1210 ip6_desync_factor)) { 1211 maxpltime = ip6_temp_preferred_lifetime - 1212 (time_second - ifa6->ia6_createtime) - 1213 ip6_desync_factor; 1214 } else 1215 maxpltime = 0; 1216 1217 if (lt6_tmp.ia6t_vltime == ND6_INFINITE_LIFETIME || 1218 lt6_tmp.ia6t_vltime > maxvltime) { 1219 lt6_tmp.ia6t_vltime = maxvltime; 1220 } 1221 if (lt6_tmp.ia6t_pltime == ND6_INFINITE_LIFETIME || 1222 lt6_tmp.ia6t_pltime > maxpltime) { 1223 lt6_tmp.ia6t_pltime = maxpltime; 1224 } 1225 } 1226 ifa6->ia6_lifetime = lt6_tmp; 1227 ifa6->ia6_updatetime = time_second; 1228 } 1229 if (ia6_match == NULL && new->ndpr_vltime) { 1230 int ifidlen; 1231 1232 /* 1233 * 5.5.3 (d) (continued) 1234 * No address matched and the valid lifetime is non-zero. 1235 * Create a new address. 1236 */ 1237 1238 /* 1239 * Prefix Length check: 1240 * If the sum of the prefix length and interface identifier 1241 * length does not equal 128 bits, the Prefix Information 1242 * option MUST be ignored. The length of the interface 1243 * identifier is defined in a separate link-type specific 1244 * document. 1245 */ 1246 ifidlen = in6_if2idlen(ifp); 1247 if (ifidlen < 0) { 1248 /* this should not happen, so we always log it. */ 1249 log(LOG_ERR, "prelist_update: IFID undefined (%s)\n", 1250 if_name(ifp)); 1251 goto end; 1252 } 1253 if (ifidlen + pr->ndpr_plen != 128) { 1254 nd6log((LOG_INFO, 1255 "prelist_update: invalid prefixlen " 1256 "%d for %s, ignored\n", 1257 pr->ndpr_plen, if_name(ifp))); 1258 goto end; 1259 } 1260 1261 if ((ia6 = in6_ifadd(new, mcast)) != NULL) { 1262 /* 1263 * note that we should use pr (not new) for reference. 1264 */ 1265 pr->ndpr_refcnt++; 1266 ia6->ia6_ndpr = pr; 1267 1268 /* 1269 * RFC 3041 3.3 (2). 1270 * When a new public address is created as described 1271 * in RFC2462, also create a new temporary address. 1272 * 1273 * RFC 3041 3.5. 1274 * When an interface connects to a new link, a new 1275 * randomized interface identifier should be generated 1276 * immediately together with a new set of temporary 1277 * addresses. Thus, we specifiy 1 as the 2nd arg of 1278 * in6_tmpifadd(). 1279 */ 1280 if (ip6_use_tempaddr) { 1281 int e; 1282 if ((e = in6_tmpifadd(ia6, 1, 1)) != 0) { 1283 nd6log((LOG_NOTICE, "prelist_update: " 1284 "failed to create a temporary " 1285 "address, errno=%d\n", 1286 e)); 1287 } 1288 } 1289 1290 /* 1291 * A newly added address might affect the status 1292 * of other addresses, so we check and update it. 1293 * XXX: what if address duplication happens? 1294 */ 1295 pfxlist_onlink_check(); 1296 } else { 1297 /* just set an error. do not bark here. */ 1298 error = EADDRNOTAVAIL; /* XXX: might be unused. */ 1299 } 1300 } 1301 1302 end: 1303 splx(s); 1304 return error; 1305 } 1306 1307 /* 1308 * A supplement function used in the on-link detection below; 1309 * detect if a given prefix has a (probably) reachable advertising router. 1310 * XXX: lengthy function name... 1311 */ 1312 static struct nd_pfxrouter * 1313 find_pfxlist_reachable_router(struct nd_prefix *pr) 1314 { 1315 struct nd_pfxrouter *pfxrtr; 1316 struct rtentry *rt; 1317 struct llinfo_nd6 *ln; 1318 1319 for (pfxrtr = LIST_FIRST(&pr->ndpr_advrtrs); pfxrtr; 1320 pfxrtr = LIST_NEXT(pfxrtr, pfr_entry)) { 1321 if ((rt = nd6_lookup(&pfxrtr->router->rtaddr, 0, 1322 pfxrtr->router->ifp)) && 1323 (ln = (struct llinfo_nd6 *)rt->rt_llinfo) && 1324 ND6_IS_LLINFO_PROBREACH(ln)) 1325 break; /* found */ 1326 } 1327 1328 return (pfxrtr); 1329 } 1330 1331 /* 1332 * Check if each prefix in the prefix list has at least one available router 1333 * that advertised the prefix (a router is "available" if its neighbor cache 1334 * entry is reachable or probably reachable). 1335 * If the check fails, the prefix may be off-link, because, for example, 1336 * we have moved from the network but the lifetime of the prefix has not 1337 * expired yet. So we should not use the prefix if there is another prefix 1338 * that has an available router. 1339 * But, if there is no prefix that has an available router, we still regards 1340 * all the prefixes as on-link. This is because we can't tell if all the 1341 * routers are simply dead or if we really moved from the network and there 1342 * is no router around us. 1343 */ 1344 void 1345 pfxlist_onlink_check() 1346 { 1347 struct nd_prefix *pr; 1348 struct in6_ifaddr *ifa; 1349 struct nd_defrouter *dr; 1350 struct nd_pfxrouter *pfxrtr = NULL; 1351 1352 /* 1353 * Check if there is a prefix that has a reachable advertising 1354 * router. 1355 */ 1356 for (pr = nd_prefix.lh_first; pr; pr = pr->ndpr_next) { 1357 if (pr->ndpr_raf_onlink && find_pfxlist_reachable_router(pr)) 1358 break; 1359 } 1360 1361 /* 1362 * If we have no such prefix, check whether we still have a router 1363 * that does not advertise any prefixes. 1364 */ 1365 if (pr == NULL) { 1366 for (dr = TAILQ_FIRST(&nd_defrouter); dr; 1367 dr = TAILQ_NEXT(dr, dr_entry)) { 1368 struct nd_prefix *pr0; 1369 1370 for (pr0 = nd_prefix.lh_first; pr0; 1371 pr0 = pr0->ndpr_next) { 1372 if ((pfxrtr = pfxrtr_lookup(pr0, dr)) != NULL) 1373 break; 1374 } 1375 if (pfxrtr != NULL) 1376 break; 1377 } 1378 } 1379 if (pr != NULL || (TAILQ_FIRST(&nd_defrouter) && pfxrtr == NULL)) { 1380 /* 1381 * There is at least one prefix that has a reachable router, 1382 * or at least a router which probably does not advertise 1383 * any prefixes. The latter would be the case when we move 1384 * to a new link where we have a router that does not provide 1385 * prefixes and we configure an address by hand. 1386 * Detach prefixes which have no reachable advertising 1387 * router, and attach other prefixes. 1388 */ 1389 for (pr = nd_prefix.lh_first; pr; pr = pr->ndpr_next) { 1390 /* XXX: a link-local prefix should never be detached */ 1391 if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr)) 1392 continue; 1393 1394 /* 1395 * we aren't interested in prefixes without the L bit 1396 * set. 1397 */ 1398 if (pr->ndpr_raf_onlink == 0) 1399 continue; 1400 1401 if ((pr->ndpr_stateflags & NDPRF_DETACHED) == 0 && 1402 find_pfxlist_reachable_router(pr) == NULL) 1403 pr->ndpr_stateflags |= NDPRF_DETACHED; 1404 if ((pr->ndpr_stateflags & NDPRF_DETACHED) != 0 && 1405 find_pfxlist_reachable_router(pr) != 0) 1406 pr->ndpr_stateflags &= ~NDPRF_DETACHED; 1407 } 1408 } else { 1409 /* there is no prefix that has a reachable router */ 1410 for (pr = nd_prefix.lh_first; pr; pr = pr->ndpr_next) { 1411 if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr)) 1412 continue; 1413 1414 if (pr->ndpr_raf_onlink == 0) 1415 continue; 1416 1417 if ((pr->ndpr_stateflags & NDPRF_DETACHED) != 0) 1418 pr->ndpr_stateflags &= ~NDPRF_DETACHED; 1419 } 1420 } 1421 1422 /* 1423 * Remove each interface route associated with a (just) detached 1424 * prefix, and reinstall the interface route for a (just) attached 1425 * prefix. Note that all attempt of reinstallation does not 1426 * necessarily success, when a same prefix is shared among multiple 1427 * interfaces. Such cases will be handled in nd6_prefix_onlink, 1428 * so we don't have to care about them. 1429 */ 1430 for (pr = nd_prefix.lh_first; pr; pr = pr->ndpr_next) { 1431 int e; 1432 char ip6buf[INET6_ADDRSTRLEN]; 1433 1434 if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr)) 1435 continue; 1436 1437 if (pr->ndpr_raf_onlink == 0) 1438 continue; 1439 1440 if ((pr->ndpr_stateflags & NDPRF_DETACHED) != 0 && 1441 (pr->ndpr_stateflags & NDPRF_ONLINK) != 0) { 1442 if ((e = nd6_prefix_offlink(pr)) != 0) { 1443 nd6log((LOG_ERR, 1444 "pfxlist_onlink_check: failed to " 1445 "make %s/%d offlink, errno=%d\n", 1446 ip6_sprintf(ip6buf, 1447 &pr->ndpr_prefix.sin6_addr), 1448 pr->ndpr_plen, e)); 1449 } 1450 } 1451 if ((pr->ndpr_stateflags & NDPRF_DETACHED) == 0 && 1452 (pr->ndpr_stateflags & NDPRF_ONLINK) == 0 && 1453 pr->ndpr_raf_onlink) { 1454 if ((e = nd6_prefix_onlink(pr)) != 0) { 1455 nd6log((LOG_ERR, 1456 "pfxlist_onlink_check: failed to " 1457 "make %s/%d onlink, errno=%d\n", 1458 ip6_sprintf(ip6buf, 1459 &pr->ndpr_prefix.sin6_addr), 1460 pr->ndpr_plen, e)); 1461 } 1462 } 1463 } 1464 1465 /* 1466 * Changes on the prefix status might affect address status as well. 1467 * Make sure that all addresses derived from an attached prefix are 1468 * attached, and that all addresses derived from a detached prefix are 1469 * detached. Note, however, that a manually configured address should 1470 * always be attached. 1471 * The precise detection logic is same as the one for prefixes. 1472 */ 1473 for (ifa = in6_ifaddr; ifa; ifa = ifa->ia_next) { 1474 if (!(ifa->ia6_flags & IN6_IFF_AUTOCONF)) 1475 continue; 1476 1477 if (ifa->ia6_ndpr == NULL) { 1478 /* 1479 * This can happen when we first configure the address 1480 * (i.e. the address exists, but the prefix does not). 1481 * XXX: complicated relationships... 1482 */ 1483 continue; 1484 } 1485 1486 if (find_pfxlist_reachable_router(ifa->ia6_ndpr)) 1487 break; 1488 } 1489 if (ifa) { 1490 for (ifa = in6_ifaddr; ifa; ifa = ifa->ia_next) { 1491 if ((ifa->ia6_flags & IN6_IFF_AUTOCONF) == 0) 1492 continue; 1493 1494 if (ifa->ia6_ndpr == NULL) /* XXX: see above. */ 1495 continue; 1496 1497 if (find_pfxlist_reachable_router(ifa->ia6_ndpr)) { 1498 if (ifa->ia6_flags & IN6_IFF_DETACHED) { 1499 ifa->ia6_flags &= ~IN6_IFF_DETACHED; 1500 ifa->ia6_flags |= IN6_IFF_TENTATIVE; 1501 nd6_dad_start((struct ifaddr *)ifa, 0); 1502 } 1503 } else { 1504 ifa->ia6_flags |= IN6_IFF_DETACHED; 1505 } 1506 } 1507 } 1508 else { 1509 for (ifa = in6_ifaddr; ifa; ifa = ifa->ia_next) { 1510 if ((ifa->ia6_flags & IN6_IFF_AUTOCONF) == 0) 1511 continue; 1512 1513 if (ifa->ia6_flags & IN6_IFF_DETACHED) { 1514 ifa->ia6_flags &= ~IN6_IFF_DETACHED; 1515 ifa->ia6_flags |= IN6_IFF_TENTATIVE; 1516 /* Do we need a delay in this case? */ 1517 nd6_dad_start((struct ifaddr *)ifa, 0); 1518 } 1519 } 1520 } 1521 } 1522 1523 static int 1524 nd6_prefix_onlink(struct nd_prefix *pr) 1525 { 1526 struct ifaddr *ifa; 1527 struct ifnet *ifp = pr->ndpr_ifp; 1528 struct sockaddr_in6 mask6; 1529 struct nd_prefix *opr; 1530 u_long rtflags; 1531 int error = 0; 1532 struct rtentry *rt = NULL; 1533 char ip6buf[INET6_ADDRSTRLEN]; 1534 1535 /* sanity check */ 1536 if ((pr->ndpr_stateflags & NDPRF_ONLINK) != 0) { 1537 nd6log((LOG_ERR, 1538 "nd6_prefix_onlink: %s/%d is already on-link\n", 1539 ip6_sprintf(ip6buf, &pr->ndpr_prefix.sin6_addr), 1540 pr->ndpr_plen)); 1541 return (EEXIST); 1542 } 1543 1544 /* 1545 * Add the interface route associated with the prefix. Before 1546 * installing the route, check if there's the same prefix on another 1547 * interface, and the prefix has already installed the interface route. 1548 * Although such a configuration is expected to be rare, we explicitly 1549 * allow it. 1550 */ 1551 for (opr = nd_prefix.lh_first; opr; opr = opr->ndpr_next) { 1552 if (opr == pr) 1553 continue; 1554 1555 if ((opr->ndpr_stateflags & NDPRF_ONLINK) == 0) 1556 continue; 1557 1558 if (opr->ndpr_plen == pr->ndpr_plen && 1559 in6_are_prefix_equal(&pr->ndpr_prefix.sin6_addr, 1560 &opr->ndpr_prefix.sin6_addr, pr->ndpr_plen)) 1561 return (0); 1562 } 1563 1564 /* 1565 * We prefer link-local addresses as the associated interface address. 1566 */ 1567 /* search for a link-local addr */ 1568 ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp, 1569 IN6_IFF_NOTREADY | IN6_IFF_ANYCAST); 1570 if (ifa == NULL) { 1571 /* XXX: freebsd does not have ifa_ifwithaf */ 1572 TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) { 1573 if (ifa->ifa_addr->sa_family == AF_INET6) 1574 break; 1575 } 1576 /* should we care about ia6_flags? */ 1577 } 1578 if (ifa == NULL) { 1579 /* 1580 * This can still happen, when, for example, we receive an RA 1581 * containing a prefix with the L bit set and the A bit clear, 1582 * after removing all IPv6 addresses on the receiving 1583 * interface. This should, of course, be rare though. 1584 */ 1585 nd6log((LOG_NOTICE, 1586 "nd6_prefix_onlink: failed to find any ifaddr" 1587 " to add route for a prefix(%s/%d) on %s\n", 1588 ip6_sprintf(ip6buf, &pr->ndpr_prefix.sin6_addr), 1589 pr->ndpr_plen, if_name(ifp))); 1590 return (0); 1591 } 1592 1593 /* 1594 * in6_ifinit() sets nd6_rtrequest to ifa_rtrequest for all ifaddrs. 1595 * ifa->ifa_rtrequest = nd6_rtrequest; 1596 */ 1597 bzero(&mask6, sizeof(mask6)); 1598 mask6.sin6_len = sizeof(mask6); 1599 mask6.sin6_addr = pr->ndpr_mask; 1600 rtflags = ifa->ifa_flags | RTF_CLONING | RTF_UP; 1601 if (nd6_need_cache(ifp)) { 1602 /* explicitly set in case ifa_flags does not set the flag. */ 1603 rtflags |= RTF_CLONING; 1604 } else { 1605 /* 1606 * explicitly clear the cloning bit in case ifa_flags sets it. 1607 */ 1608 rtflags &= ~RTF_CLONING; 1609 } 1610 error = rtrequest(RTM_ADD, (struct sockaddr *)&pr->ndpr_prefix, 1611 ifa->ifa_addr, (struct sockaddr *)&mask6, rtflags, &rt); 1612 if (error == 0) { 1613 if (rt != NULL) /* this should be non NULL, though */ 1614 nd6_rtmsg(RTM_ADD, rt); 1615 pr->ndpr_stateflags |= NDPRF_ONLINK; 1616 } else { 1617 char ip6bufg[INET6_ADDRSTRLEN], ip6bufm[INET6_ADDRSTRLEN]; 1618 nd6log((LOG_ERR, "nd6_prefix_onlink: failed to add route for a" 1619 " prefix (%s/%d) on %s, gw=%s, mask=%s, flags=%lx " 1620 "errno = %d\n", 1621 ip6_sprintf(ip6buf, &pr->ndpr_prefix.sin6_addr), 1622 pr->ndpr_plen, if_name(ifp), 1623 ip6_sprintf(ip6bufg, &((struct sockaddr_in6 *)ifa->ifa_addr)->sin6_addr), 1624 ip6_sprintf(ip6bufm, &mask6.sin6_addr), rtflags, error)); 1625 } 1626 1627 if (rt != NULL) { 1628 RT_LOCK(rt); 1629 RT_REMREF(rt); 1630 RT_UNLOCK(rt); 1631 } 1632 1633 return (error); 1634 } 1635 1636 static int 1637 nd6_prefix_offlink(struct nd_prefix *pr) 1638 { 1639 int error = 0; 1640 struct ifnet *ifp = pr->ndpr_ifp; 1641 struct nd_prefix *opr; 1642 struct sockaddr_in6 sa6, mask6; 1643 struct rtentry *rt = NULL; 1644 char ip6buf[INET6_ADDRSTRLEN]; 1645 1646 /* sanity check */ 1647 if ((pr->ndpr_stateflags & NDPRF_ONLINK) == 0) { 1648 nd6log((LOG_ERR, 1649 "nd6_prefix_offlink: %s/%d is already off-link\n", 1650 ip6_sprintf(ip6buf, &pr->ndpr_prefix.sin6_addr), 1651 pr->ndpr_plen)); 1652 return (EEXIST); 1653 } 1654 1655 bzero(&sa6, sizeof(sa6)); 1656 sa6.sin6_family = AF_INET6; 1657 sa6.sin6_len = sizeof(sa6); 1658 bcopy(&pr->ndpr_prefix.sin6_addr, &sa6.sin6_addr, 1659 sizeof(struct in6_addr)); 1660 bzero(&mask6, sizeof(mask6)); 1661 mask6.sin6_family = AF_INET6; 1662 mask6.sin6_len = sizeof(sa6); 1663 bcopy(&pr->ndpr_mask, &mask6.sin6_addr, sizeof(struct in6_addr)); 1664 error = rtrequest(RTM_DELETE, (struct sockaddr *)&sa6, NULL, 1665 (struct sockaddr *)&mask6, 0, &rt); 1666 if (error == 0) { 1667 pr->ndpr_stateflags &= ~NDPRF_ONLINK; 1668 1669 /* report the route deletion to the routing socket. */ 1670 if (rt != NULL) 1671 nd6_rtmsg(RTM_DELETE, rt); 1672 1673 /* 1674 * There might be the same prefix on another interface, 1675 * the prefix which could not be on-link just because we have 1676 * the interface route (see comments in nd6_prefix_onlink). 1677 * If there's one, try to make the prefix on-link on the 1678 * interface. 1679 */ 1680 for (opr = nd_prefix.lh_first; opr; opr = opr->ndpr_next) { 1681 if (opr == pr) 1682 continue; 1683 1684 if ((opr->ndpr_stateflags & NDPRF_ONLINK) != 0) 1685 continue; 1686 1687 /* 1688 * KAME specific: detached prefixes should not be 1689 * on-link. 1690 */ 1691 if ((opr->ndpr_stateflags & NDPRF_DETACHED) != 0) 1692 continue; 1693 1694 if (opr->ndpr_plen == pr->ndpr_plen && 1695 in6_are_prefix_equal(&pr->ndpr_prefix.sin6_addr, 1696 &opr->ndpr_prefix.sin6_addr, pr->ndpr_plen)) { 1697 int e; 1698 1699 if ((e = nd6_prefix_onlink(opr)) != 0) { 1700 nd6log((LOG_ERR, 1701 "nd6_prefix_offlink: failed to " 1702 "recover a prefix %s/%d from %s " 1703 "to %s (errno = %d)\n", 1704 ip6_sprintf(ip6buf, 1705 &opr->ndpr_prefix.sin6_addr), 1706 opr->ndpr_plen, if_name(ifp), 1707 if_name(opr->ndpr_ifp), e)); 1708 } 1709 } 1710 } 1711 } else { 1712 /* XXX: can we still set the NDPRF_ONLINK flag? */ 1713 nd6log((LOG_ERR, 1714 "nd6_prefix_offlink: failed to delete route: " 1715 "%s/%d on %s (errno = %d)\n", 1716 ip6_sprintf(ip6buf, &sa6.sin6_addr), pr->ndpr_plen, 1717 if_name(ifp), error)); 1718 } 1719 1720 if (rt != NULL) { 1721 RTFREE(rt); 1722 } 1723 1724 return (error); 1725 } 1726 1727 static struct in6_ifaddr * 1728 in6_ifadd(struct nd_prefixctl *pr, int mcast) 1729 { 1730 struct ifnet *ifp = pr->ndpr_ifp; 1731 struct ifaddr *ifa; 1732 struct in6_aliasreq ifra; 1733 struct in6_ifaddr *ia, *ib; 1734 int error, plen0; 1735 struct in6_addr mask; 1736 int prefixlen = pr->ndpr_plen; 1737 int updateflags; 1738 char ip6buf[INET6_ADDRSTRLEN]; 1739 1740 in6_prefixlen2mask(&mask, prefixlen); 1741 1742 /* 1743 * find a link-local address (will be interface ID). 1744 * Is it really mandatory? Theoretically, a global or a site-local 1745 * address can be configured without a link-local address, if we 1746 * have a unique interface identifier... 1747 * 1748 * it is not mandatory to have a link-local address, we can generate 1749 * interface identifier on the fly. we do this because: 1750 * (1) it should be the easiest way to find interface identifier. 1751 * (2) RFC2462 5.4 suggesting the use of the same interface identifier 1752 * for multiple addresses on a single interface, and possible shortcut 1753 * of DAD. we omitted DAD for this reason in the past. 1754 * (3) a user can prevent autoconfiguration of global address 1755 * by removing link-local address by hand (this is partly because we 1756 * don't have other way to control the use of IPv6 on an interface. 1757 * this has been our design choice - cf. NRL's "ifconfig auto"). 1758 * (4) it is easier to manage when an interface has addresses 1759 * with the same interface identifier, than to have multiple addresses 1760 * with different interface identifiers. 1761 */ 1762 ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp, 0); /* 0 is OK? */ 1763 if (ifa) 1764 ib = (struct in6_ifaddr *)ifa; 1765 else 1766 return NULL; 1767 1768 /* prefixlen + ifidlen must be equal to 128 */ 1769 plen0 = in6_mask2len(&ib->ia_prefixmask.sin6_addr, NULL); 1770 if (prefixlen != plen0) { 1771 nd6log((LOG_INFO, "in6_ifadd: wrong prefixlen for %s " 1772 "(prefix=%d ifid=%d)\n", 1773 if_name(ifp), prefixlen, 128 - plen0)); 1774 return NULL; 1775 } 1776 1777 /* make ifaddr */ 1778 1779 bzero(&ifra, sizeof(ifra)); 1780 /* 1781 * in6_update_ifa() does not use ifra_name, but we accurately set it 1782 * for safety. 1783 */ 1784 strncpy(ifra.ifra_name, if_name(ifp), sizeof(ifra.ifra_name)); 1785 ifra.ifra_addr.sin6_family = AF_INET6; 1786 ifra.ifra_addr.sin6_len = sizeof(struct sockaddr_in6); 1787 /* prefix */ 1788 ifra.ifra_addr.sin6_addr = pr->ndpr_prefix.sin6_addr; 1789 ifra.ifra_addr.sin6_addr.s6_addr32[0] &= mask.s6_addr32[0]; 1790 ifra.ifra_addr.sin6_addr.s6_addr32[1] &= mask.s6_addr32[1]; 1791 ifra.ifra_addr.sin6_addr.s6_addr32[2] &= mask.s6_addr32[2]; 1792 ifra.ifra_addr.sin6_addr.s6_addr32[3] &= mask.s6_addr32[3]; 1793 1794 /* interface ID */ 1795 ifra.ifra_addr.sin6_addr.s6_addr32[0] |= 1796 (ib->ia_addr.sin6_addr.s6_addr32[0] & ~mask.s6_addr32[0]); 1797 ifra.ifra_addr.sin6_addr.s6_addr32[1] |= 1798 (ib->ia_addr.sin6_addr.s6_addr32[1] & ~mask.s6_addr32[1]); 1799 ifra.ifra_addr.sin6_addr.s6_addr32[2] |= 1800 (ib->ia_addr.sin6_addr.s6_addr32[2] & ~mask.s6_addr32[2]); 1801 ifra.ifra_addr.sin6_addr.s6_addr32[3] |= 1802 (ib->ia_addr.sin6_addr.s6_addr32[3] & ~mask.s6_addr32[3]); 1803 1804 /* new prefix mask. */ 1805 ifra.ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6); 1806 ifra.ifra_prefixmask.sin6_family = AF_INET6; 1807 bcopy(&mask, &ifra.ifra_prefixmask.sin6_addr, 1808 sizeof(ifra.ifra_prefixmask.sin6_addr)); 1809 1810 /* lifetimes. */ 1811 ifra.ifra_lifetime.ia6t_vltime = pr->ndpr_vltime; 1812 ifra.ifra_lifetime.ia6t_pltime = pr->ndpr_pltime; 1813 1814 /* XXX: scope zone ID? */ 1815 1816 ifra.ifra_flags |= IN6_IFF_AUTOCONF; /* obey autoconf */ 1817 1818 /* 1819 * Make sure that we do not have this address already. This should 1820 * usually not happen, but we can still see this case, e.g., if we 1821 * have manually configured the exact address to be configured. 1822 */ 1823 if (in6ifa_ifpwithaddr(ifp, &ifra.ifra_addr.sin6_addr) != NULL) { 1824 /* this should be rare enough to make an explicit log */ 1825 log(LOG_INFO, "in6_ifadd: %s is already configured\n", 1826 ip6_sprintf(ip6buf, &ifra.ifra_addr.sin6_addr)); 1827 return (NULL); 1828 } 1829 1830 /* 1831 * Allocate ifaddr structure, link into chain, etc. 1832 * If we are going to create a new address upon receiving a multicasted 1833 * RA, we need to impose a random delay before starting DAD. 1834 * [draft-ietf-ipv6-rfc2462bis-02.txt, Section 5.4.2] 1835 */ 1836 updateflags = 0; 1837 if (mcast) 1838 updateflags |= IN6_IFAUPDATE_DADDELAY; 1839 if ((error = in6_update_ifa(ifp, &ifra, NULL, updateflags)) != 0) { 1840 nd6log((LOG_ERR, 1841 "in6_ifadd: failed to make ifaddr %s on %s (errno=%d)\n", 1842 ip6_sprintf(ip6buf, &ifra.ifra_addr.sin6_addr), 1843 if_name(ifp), error)); 1844 return (NULL); /* ifaddr must not have been allocated. */ 1845 } 1846 1847 ia = in6ifa_ifpwithaddr(ifp, &ifra.ifra_addr.sin6_addr); 1848 1849 return (ia); /* this is always non-NULL */ 1850 } 1851 1852 /* 1853 * ia0 - corresponding public address 1854 */ 1855 int 1856 in6_tmpifadd(const struct in6_ifaddr *ia0, int forcegen, int delay) 1857 { 1858 struct ifnet *ifp = ia0->ia_ifa.ifa_ifp; 1859 struct in6_ifaddr *newia, *ia; 1860 struct in6_aliasreq ifra; 1861 int i, error; 1862 int trylimit = 3; /* XXX: adhoc value */ 1863 int updateflags; 1864 u_int32_t randid[2]; 1865 time_t vltime0, pltime0; 1866 1867 bzero(&ifra, sizeof(ifra)); 1868 strncpy(ifra.ifra_name, if_name(ifp), sizeof(ifra.ifra_name)); 1869 ifra.ifra_addr = ia0->ia_addr; 1870 /* copy prefix mask */ 1871 ifra.ifra_prefixmask = ia0->ia_prefixmask; 1872 /* clear the old IFID */ 1873 for (i = 0; i < 4; i++) { 1874 ifra.ifra_addr.sin6_addr.s6_addr32[i] &= 1875 ifra.ifra_prefixmask.sin6_addr.s6_addr32[i]; 1876 } 1877 1878 again: 1879 if (in6_get_tmpifid(ifp, (u_int8_t *)randid, 1880 (const u_int8_t *)&ia0->ia_addr.sin6_addr.s6_addr[8], forcegen)) { 1881 nd6log((LOG_NOTICE, "in6_tmpifadd: failed to find a good " 1882 "random IFID\n")); 1883 return (EINVAL); 1884 } 1885 ifra.ifra_addr.sin6_addr.s6_addr32[2] |= 1886 (randid[0] & ~(ifra.ifra_prefixmask.sin6_addr.s6_addr32[2])); 1887 ifra.ifra_addr.sin6_addr.s6_addr32[3] |= 1888 (randid[1] & ~(ifra.ifra_prefixmask.sin6_addr.s6_addr32[3])); 1889 1890 /* 1891 * in6_get_tmpifid() quite likely provided a unique interface ID. 1892 * However, we may still have a chance to see collision, because 1893 * there may be a time lag between generation of the ID and generation 1894 * of the address. So, we'll do one more sanity check. 1895 */ 1896 for (ia = in6_ifaddr; ia; ia = ia->ia_next) { 1897 if (IN6_ARE_ADDR_EQUAL(&ia->ia_addr.sin6_addr, 1898 &ifra.ifra_addr.sin6_addr)) { 1899 if (trylimit-- == 0) { 1900 /* 1901 * Give up. Something strange should have 1902 * happened. 1903 */ 1904 nd6log((LOG_NOTICE, "in6_tmpifadd: failed to " 1905 "find a unique random IFID\n")); 1906 return (EEXIST); 1907 } 1908 forcegen = 1; 1909 goto again; 1910 } 1911 } 1912 1913 /* 1914 * The Valid Lifetime is the lower of the Valid Lifetime of the 1915 * public address or TEMP_VALID_LIFETIME. 1916 * The Preferred Lifetime is the lower of the Preferred Lifetime 1917 * of the public address or TEMP_PREFERRED_LIFETIME - 1918 * DESYNC_FACTOR. 1919 */ 1920 if (ia0->ia6_lifetime.ia6t_vltime != ND6_INFINITE_LIFETIME) { 1921 vltime0 = IFA6_IS_INVALID(ia0) ? 0 : 1922 (ia0->ia6_lifetime.ia6t_vltime - 1923 (time_second - ia0->ia6_updatetime)); 1924 if (vltime0 > ip6_temp_valid_lifetime) 1925 vltime0 = ip6_temp_valid_lifetime; 1926 } else 1927 vltime0 = ip6_temp_valid_lifetime; 1928 if (ia0->ia6_lifetime.ia6t_pltime != ND6_INFINITE_LIFETIME) { 1929 pltime0 = IFA6_IS_DEPRECATED(ia0) ? 0 : 1930 (ia0->ia6_lifetime.ia6t_pltime - 1931 (time_second - ia0->ia6_updatetime)); 1932 if (pltime0 > ip6_temp_preferred_lifetime - ip6_desync_factor){ 1933 pltime0 = ip6_temp_preferred_lifetime - 1934 ip6_desync_factor; 1935 } 1936 } else 1937 pltime0 = ip6_temp_preferred_lifetime - ip6_desync_factor; 1938 ifra.ifra_lifetime.ia6t_vltime = vltime0; 1939 ifra.ifra_lifetime.ia6t_pltime = pltime0; 1940 1941 /* 1942 * A temporary address is created only if this calculated Preferred 1943 * Lifetime is greater than REGEN_ADVANCE time units. 1944 */ 1945 if (ifra.ifra_lifetime.ia6t_pltime <= ip6_temp_regen_advance) 1946 return (0); 1947 1948 /* XXX: scope zone ID? */ 1949 1950 ifra.ifra_flags |= (IN6_IFF_AUTOCONF|IN6_IFF_TEMPORARY); 1951 1952 /* allocate ifaddr structure, link into chain, etc. */ 1953 updateflags = 0; 1954 if (delay) 1955 updateflags |= IN6_IFAUPDATE_DADDELAY; 1956 if ((error = in6_update_ifa(ifp, &ifra, NULL, updateflags)) != 0) 1957 return (error); 1958 1959 newia = in6ifa_ifpwithaddr(ifp, &ifra.ifra_addr.sin6_addr); 1960 if (newia == NULL) { /* XXX: can it happen? */ 1961 nd6log((LOG_ERR, 1962 "in6_tmpifadd: ifa update succeeded, but we got " 1963 "no ifaddr\n")); 1964 return (EINVAL); /* XXX */ 1965 } 1966 newia->ia6_ndpr = ia0->ia6_ndpr; 1967 newia->ia6_ndpr->ndpr_refcnt++; 1968 1969 /* 1970 * A newly added address might affect the status of other addresses. 1971 * XXX: when the temporary address is generated with a new public 1972 * address, the onlink check is redundant. However, it would be safe 1973 * to do the check explicitly everywhere a new address is generated, 1974 * and, in fact, we surely need the check when we create a new 1975 * temporary address due to deprecation of an old temporary address. 1976 */ 1977 pfxlist_onlink_check(); 1978 1979 return (0); 1980 } 1981 1982 static int 1983 in6_init_prefix_ltimes(struct nd_prefix *ndpr) 1984 { 1985 if (ndpr->ndpr_pltime == ND6_INFINITE_LIFETIME) 1986 ndpr->ndpr_preferred = 0; 1987 else 1988 ndpr->ndpr_preferred = time_second + ndpr->ndpr_pltime; 1989 if (ndpr->ndpr_vltime == ND6_INFINITE_LIFETIME) 1990 ndpr->ndpr_expire = 0; 1991 else 1992 ndpr->ndpr_expire = time_second + ndpr->ndpr_vltime; 1993 1994 return 0; 1995 } 1996 1997 static void 1998 in6_init_address_ltimes(struct nd_prefix *new, struct in6_addrlifetime *lt6) 1999 { 2000 /* init ia6t_expire */ 2001 if (lt6->ia6t_vltime == ND6_INFINITE_LIFETIME) 2002 lt6->ia6t_expire = 0; 2003 else { 2004 lt6->ia6t_expire = time_second; 2005 lt6->ia6t_expire += lt6->ia6t_vltime; 2006 } 2007 2008 /* init ia6t_preferred */ 2009 if (lt6->ia6t_pltime == ND6_INFINITE_LIFETIME) 2010 lt6->ia6t_preferred = 0; 2011 else { 2012 lt6->ia6t_preferred = time_second; 2013 lt6->ia6t_preferred += lt6->ia6t_pltime; 2014 } 2015 } 2016 2017 /* 2018 * Delete all the routing table entries that use the specified gateway. 2019 * XXX: this function causes search through all entries of routing table, so 2020 * it shouldn't be called when acting as a router. 2021 */ 2022 void 2023 rt6_flush(struct in6_addr *gateway, struct ifnet *ifp) 2024 { 2025 2026 struct radix_node_head *rnh = rt_tables[0][AF_INET6]; 2027 int s = splnet(); 2028 2029 /* We'll care only link-local addresses */ 2030 if (!IN6_IS_ADDR_LINKLOCAL(gateway)) { 2031 splx(s); 2032 return; 2033 } 2034 2035 RADIX_NODE_HEAD_LOCK(rnh); 2036 rnh->rnh_walktree(rnh, rt6_deleteroute, (void *)gateway); 2037 RADIX_NODE_HEAD_UNLOCK(rnh); 2038 splx(s); 2039 } 2040 2041 static int 2042 rt6_deleteroute(struct radix_node *rn, void *arg) 2043 { 2044 #define SIN6(s) ((struct sockaddr_in6 *)s) 2045 struct rtentry *rt = (struct rtentry *)rn; 2046 struct in6_addr *gate = (struct in6_addr *)arg; 2047 2048 if (rt->rt_gateway == NULL || rt->rt_gateway->sa_family != AF_INET6) 2049 return (0); 2050 2051 if (!IN6_ARE_ADDR_EQUAL(gate, &SIN6(rt->rt_gateway)->sin6_addr)) { 2052 return (0); 2053 } 2054 2055 /* 2056 * Do not delete a static route. 2057 * XXX: this seems to be a bit ad-hoc. Should we consider the 2058 * 'cloned' bit instead? 2059 */ 2060 if ((rt->rt_flags & RTF_STATIC) != 0) 2061 return (0); 2062 2063 /* 2064 * We delete only host route. This means, in particular, we don't 2065 * delete default route. 2066 */ 2067 if ((rt->rt_flags & RTF_HOST) == 0) 2068 return (0); 2069 2070 return (rtrequest(RTM_DELETE, rt_key(rt), rt->rt_gateway, 2071 rt_mask(rt), rt->rt_flags, 0)); 2072 #undef SIN6 2073 } 2074 2075 int 2076 nd6_setdefaultiface(int ifindex) 2077 { 2078 int error = 0; 2079 2080 if (ifindex < 0 || if_index < ifindex) 2081 return (EINVAL); 2082 if (ifindex != 0 && !ifnet_byindex(ifindex)) 2083 return (EINVAL); 2084 2085 if (nd6_defifindex != ifindex) { 2086 nd6_defifindex = ifindex; 2087 if (nd6_defifindex > 0) 2088 nd6_defifp = ifnet_byindex(nd6_defifindex); 2089 else 2090 nd6_defifp = NULL; 2091 2092 /* 2093 * Our current implementation assumes one-to-one maping between 2094 * interfaces and links, so it would be natural to use the 2095 * default interface as the default link. 2096 */ 2097 scope6_setdefault(nd6_defifp); 2098 } 2099 2100 return (error); 2101 }
Cache object: ac0de58d81cd682ecd6b80d54264c6b5
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