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sys/netinet6/nd6_rtr.c
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1 /* $FreeBSD$ */ 2 /* $KAME: nd6_rtr.c,v 1.111 2001/04/27 01:37:15 jinmei Exp $ */ 3 4 /*- 5 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the project nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 #include "opt_inet.h" 34 #include "opt_inet6.h" 35 36 #include <sys/param.h> 37 #include <sys/systm.h> 38 #include <sys/malloc.h> 39 #include <sys/mbuf.h> 40 #include <sys/socket.h> 41 #include <sys/sockio.h> 42 #include <sys/time.h> 43 #include <sys/kernel.h> 44 #include <sys/errno.h> 45 #include <sys/syslog.h> 46 #include <sys/queue.h> 47 48 #include <net/if.h> 49 #include <net/if_types.h> 50 #include <net/if_dl.h> 51 #include <net/route.h> 52 #include <net/radix.h> 53 54 #include <netinet/in.h> 55 #include <netinet6/in6_var.h> 56 #include <netinet6/in6_ifattach.h> 57 #include <netinet/ip6.h> 58 #include <netinet6/ip6_var.h> 59 #include <netinet6/nd6.h> 60 #include <netinet/icmp6.h> 61 #include <netinet6/scope6_var.h> 62 63 #define SDL(s) ((struct sockaddr_dl *)s) 64 65 static int rtpref __P((struct nd_defrouter *)); 66 static struct nd_defrouter *defrtrlist_update __P((struct nd_defrouter *)); 67 static int prelist_update __P((struct nd_prefixctl *, struct nd_defrouter *, 68 struct mbuf *, int)); 69 static struct in6_ifaddr *in6_ifadd __P((struct nd_prefixctl *, int)); 70 static struct nd_pfxrouter *pfxrtr_lookup __P((struct nd_prefix *, 71 struct nd_defrouter *)); 72 static void pfxrtr_add __P((struct nd_prefix *, struct nd_defrouter *)); 73 static void pfxrtr_del __P((struct nd_pfxrouter *)); 74 static struct nd_pfxrouter *find_pfxlist_reachable_router 75 __P((struct nd_prefix *)); 76 static void defrouter_delreq __P((struct nd_defrouter *)); 77 static void nd6_rtmsg __P((int, struct rtentry *)); 78 79 static int in6_init_prefix_ltimes __P((struct nd_prefix *)); 80 static void in6_init_address_ltimes __P((struct nd_prefix *, 81 struct in6_addrlifetime *)); 82 83 static int rt6_deleteroute __P((struct radix_node *, void *)); 84 85 extern int nd6_recalc_reachtm_interval; 86 87 static struct ifnet *nd6_defifp; 88 int nd6_defifindex; 89 90 int ip6_use_tempaddr = 0; 91 92 int ip6_desync_factor; 93 u_int32_t ip6_temp_preferred_lifetime = DEF_TEMP_PREFERRED_LIFETIME; 94 u_int32_t ip6_temp_valid_lifetime = DEF_TEMP_VALID_LIFETIME; 95 /* 96 * shorter lifetimes for debugging purposes. 97 int ip6_temp_preferred_lifetime = 800; 98 static int ip6_temp_valid_lifetime = 1800; 99 */ 100 int ip6_temp_regen_advance = TEMPADDR_REGEN_ADVANCE; 101 102 /* RTPREF_MEDIUM has to be 0! */ 103 #define RTPREF_HIGH 1 104 #define RTPREF_MEDIUM 0 105 #define RTPREF_LOW (-1) 106 #define RTPREF_RESERVED (-2) 107 #define RTPREF_INVALID (-3) /* internal */ 108 109 /* 110 * Receive Router Solicitation Message - just for routers. 111 * Router solicitation/advertisement is mostly managed by userland program 112 * (rtadvd) so here we have no function like nd6_ra_output(). 113 * 114 * Based on RFC 2461 115 */ 116 void 117 nd6_rs_input(struct mbuf *m, int off, int icmp6len) 118 { 119 struct ifnet *ifp = m->m_pkthdr.rcvif; 120 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 121 struct nd_router_solicit *nd_rs; 122 struct in6_addr saddr6 = ip6->ip6_src; 123 char *lladdr = NULL; 124 int lladdrlen = 0; 125 union nd_opts ndopts; 126 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 127 128 /* If I'm not a router, ignore it. */ 129 if (ip6_accept_rtadv != 0 || ip6_forwarding != 1) 130 goto freeit; 131 132 /* Sanity checks */ 133 if (ip6->ip6_hlim != 255) { 134 nd6log((LOG_ERR, 135 "nd6_rs_input: invalid hlim (%d) from %s to %s on %s\n", 136 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src), 137 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp))); 138 goto bad; 139 } 140 141 /* 142 * Don't update the neighbor cache, if src = ::. 143 * This indicates that the src has no IP address assigned yet. 144 */ 145 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) 146 goto freeit; 147 148 #ifndef PULLDOWN_TEST 149 IP6_EXTHDR_CHECK(m, off, icmp6len,); 150 nd_rs = (struct nd_router_solicit *)((caddr_t)ip6 + off); 151 #else 152 IP6_EXTHDR_GET(nd_rs, struct nd_router_solicit *, m, off, icmp6len); 153 if (nd_rs == NULL) { 154 icmp6stat.icp6s_tooshort++; 155 return; 156 } 157 #endif 158 159 icmp6len -= sizeof(*nd_rs); 160 nd6_option_init(nd_rs + 1, icmp6len, &ndopts); 161 if (nd6_options(&ndopts) < 0) { 162 nd6log((LOG_INFO, 163 "nd6_rs_input: invalid ND option, ignored\n")); 164 /* nd6_options have incremented stats */ 165 goto freeit; 166 } 167 168 if (ndopts.nd_opts_src_lladdr) { 169 lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1); 170 lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3; 171 } 172 173 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 174 nd6log((LOG_INFO, 175 "nd6_rs_input: lladdrlen mismatch for %s " 176 "(if %d, RS packet %d)\n", 177 ip6_sprintf(ip6bufs, &saddr6), 178 ifp->if_addrlen, lladdrlen - 2)); 179 goto bad; 180 } 181 182 nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, ND_ROUTER_SOLICIT, 0); 183 184 freeit: 185 m_freem(m); 186 return; 187 188 bad: 189 icmp6stat.icp6s_badrs++; 190 m_freem(m); 191 } 192 193 /* 194 * Receive Router Advertisement Message. 195 * 196 * Based on RFC 2461 197 * TODO: on-link bit on prefix information 198 * TODO: ND_RA_FLAG_{OTHER,MANAGED} processing 199 */ 200 void 201 nd6_ra_input(struct mbuf *m, int off, int icmp6len) 202 { 203 struct ifnet *ifp = m->m_pkthdr.rcvif; 204 struct nd_ifinfo *ndi = ND_IFINFO(ifp); 205 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 206 struct nd_router_advert *nd_ra; 207 struct in6_addr saddr6 = ip6->ip6_src; 208 int mcast = 0; 209 union nd_opts ndopts; 210 struct nd_defrouter *dr; 211 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 212 213 /* 214 * We only accept RAs only when 215 * the system-wide variable allows the acceptance, and 216 * per-interface variable allows RAs on the receiving interface. 217 */ 218 if (ip6_accept_rtadv == 0) 219 goto freeit; 220 if (!(ndi->flags & ND6_IFF_ACCEPT_RTADV)) 221 goto freeit; 222 223 if (ip6->ip6_hlim != 255) { 224 nd6log((LOG_ERR, 225 "nd6_ra_input: invalid hlim (%d) from %s to %s on %s\n", 226 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src), 227 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp))); 228 goto bad; 229 } 230 231 if (!IN6_IS_ADDR_LINKLOCAL(&saddr6)) { 232 nd6log((LOG_ERR, 233 "nd6_ra_input: src %s is not link-local\n", 234 ip6_sprintf(ip6bufs, &saddr6))); 235 goto bad; 236 } 237 238 #ifndef PULLDOWN_TEST 239 IP6_EXTHDR_CHECK(m, off, icmp6len,); 240 nd_ra = (struct nd_router_advert *)((caddr_t)ip6 + off); 241 #else 242 IP6_EXTHDR_GET(nd_ra, struct nd_router_advert *, m, off, icmp6len); 243 if (nd_ra == NULL) { 244 icmp6stat.icp6s_tooshort++; 245 return; 246 } 247 #endif 248 249 icmp6len -= sizeof(*nd_ra); 250 nd6_option_init(nd_ra + 1, icmp6len, &ndopts); 251 if (nd6_options(&ndopts) < 0) { 252 nd6log((LOG_INFO, 253 "nd6_ra_input: invalid ND option, ignored\n")); 254 /* nd6_options have incremented stats */ 255 goto freeit; 256 } 257 258 { 259 struct nd_defrouter dr0; 260 u_int32_t advreachable = nd_ra->nd_ra_reachable; 261 262 /* remember if this is a multicasted advertisement */ 263 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) 264 mcast = 1; 265 266 bzero(&dr0, sizeof(dr0)); 267 dr0.rtaddr = saddr6; 268 dr0.flags = nd_ra->nd_ra_flags_reserved; 269 dr0.rtlifetime = ntohs(nd_ra->nd_ra_router_lifetime); 270 dr0.expire = time_second + dr0.rtlifetime; 271 dr0.ifp = ifp; 272 /* unspecified or not? (RFC 2461 6.3.4) */ 273 if (advreachable) { 274 advreachable = ntohl(advreachable); 275 if (advreachable <= MAX_REACHABLE_TIME && 276 ndi->basereachable != advreachable) { 277 ndi->basereachable = advreachable; 278 ndi->reachable = ND_COMPUTE_RTIME(ndi->basereachable); 279 ndi->recalctm = nd6_recalc_reachtm_interval; /* reset */ 280 } 281 } 282 if (nd_ra->nd_ra_retransmit) 283 ndi->retrans = ntohl(nd_ra->nd_ra_retransmit); 284 if (nd_ra->nd_ra_curhoplimit) 285 ndi->chlim = nd_ra->nd_ra_curhoplimit; 286 dr = defrtrlist_update(&dr0); 287 } 288 289 /* 290 * prefix 291 */ 292 if (ndopts.nd_opts_pi) { 293 struct nd_opt_hdr *pt; 294 struct nd_opt_prefix_info *pi = NULL; 295 struct nd_prefixctl pr; 296 297 for (pt = (struct nd_opt_hdr *)ndopts.nd_opts_pi; 298 pt <= (struct nd_opt_hdr *)ndopts.nd_opts_pi_end; 299 pt = (struct nd_opt_hdr *)((caddr_t)pt + 300 (pt->nd_opt_len << 3))) { 301 if (pt->nd_opt_type != ND_OPT_PREFIX_INFORMATION) 302 continue; 303 pi = (struct nd_opt_prefix_info *)pt; 304 305 if (pi->nd_opt_pi_len != 4) { 306 nd6log((LOG_INFO, 307 "nd6_ra_input: invalid option " 308 "len %d for prefix information option, " 309 "ignored\n", pi->nd_opt_pi_len)); 310 continue; 311 } 312 313 if (128 < pi->nd_opt_pi_prefix_len) { 314 nd6log((LOG_INFO, 315 "nd6_ra_input: invalid prefix " 316 "len %d for prefix information option, " 317 "ignored\n", pi->nd_opt_pi_prefix_len)); 318 continue; 319 } 320 321 if (IN6_IS_ADDR_MULTICAST(&pi->nd_opt_pi_prefix) 322 || IN6_IS_ADDR_LINKLOCAL(&pi->nd_opt_pi_prefix)) { 323 nd6log((LOG_INFO, 324 "nd6_ra_input: invalid prefix " 325 "%s, ignored\n", 326 ip6_sprintf(ip6bufs, 327 &pi->nd_opt_pi_prefix))); 328 continue; 329 } 330 331 bzero(&pr, sizeof(pr)); 332 pr.ndpr_prefix.sin6_family = AF_INET6; 333 pr.ndpr_prefix.sin6_len = sizeof(pr.ndpr_prefix); 334 pr.ndpr_prefix.sin6_addr = pi->nd_opt_pi_prefix; 335 pr.ndpr_ifp = (struct ifnet *)m->m_pkthdr.rcvif; 336 337 pr.ndpr_raf_onlink = (pi->nd_opt_pi_flags_reserved & 338 ND_OPT_PI_FLAG_ONLINK) ? 1 : 0; 339 pr.ndpr_raf_auto = (pi->nd_opt_pi_flags_reserved & 340 ND_OPT_PI_FLAG_AUTO) ? 1 : 0; 341 pr.ndpr_plen = pi->nd_opt_pi_prefix_len; 342 pr.ndpr_vltime = ntohl(pi->nd_opt_pi_valid_time); 343 pr.ndpr_pltime = ntohl(pi->nd_opt_pi_preferred_time); 344 (void)prelist_update(&pr, dr, m, mcast); 345 } 346 } 347 348 /* 349 * MTU 350 */ 351 if (ndopts.nd_opts_mtu && ndopts.nd_opts_mtu->nd_opt_mtu_len == 1) { 352 u_long mtu; 353 u_long maxmtu; 354 355 mtu = (u_long)ntohl(ndopts.nd_opts_mtu->nd_opt_mtu_mtu); 356 357 /* lower bound */ 358 if (mtu < IPV6_MMTU) { 359 nd6log((LOG_INFO, "nd6_ra_input: bogus mtu option " 360 "mtu=%lu sent from %s, ignoring\n", 361 mtu, ip6_sprintf(ip6bufs, &ip6->ip6_src))); 362 goto skip; 363 } 364 365 /* upper bound */ 366 maxmtu = (ndi->maxmtu && ndi->maxmtu < ifp->if_mtu) 367 ? ndi->maxmtu : ifp->if_mtu; 368 if (mtu <= maxmtu) { 369 int change = (ndi->linkmtu != mtu); 370 371 ndi->linkmtu = mtu; 372 if (change) /* in6_maxmtu may change */ 373 in6_setmaxmtu(); 374 } else { 375 nd6log((LOG_INFO, "nd6_ra_input: bogus mtu " 376 "mtu=%lu sent from %s; " 377 "exceeds maxmtu %lu, ignoring\n", 378 mtu, ip6_sprintf(ip6bufs, &ip6->ip6_src), maxmtu)); 379 } 380 } 381 382 skip: 383 384 /* 385 * Source link layer address 386 */ 387 { 388 char *lladdr = NULL; 389 int lladdrlen = 0; 390 391 if (ndopts.nd_opts_src_lladdr) { 392 lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1); 393 lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3; 394 } 395 396 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 397 nd6log((LOG_INFO, 398 "nd6_ra_input: lladdrlen mismatch for %s " 399 "(if %d, RA packet %d)\n", ip6_sprintf(ip6bufs, &saddr6), 400 ifp->if_addrlen, lladdrlen - 2)); 401 goto bad; 402 } 403 404 nd6_cache_lladdr(ifp, &saddr6, lladdr, 405 lladdrlen, ND_ROUTER_ADVERT, 0); 406 407 /* 408 * Installing a link-layer address might change the state of the 409 * router's neighbor cache, which might also affect our on-link 410 * detection of adveritsed prefixes. 411 */ 412 pfxlist_onlink_check(); 413 } 414 415 freeit: 416 m_freem(m); 417 return; 418 419 bad: 420 icmp6stat.icp6s_badra++; 421 m_freem(m); 422 } 423 424 /* 425 * default router list proccessing sub routines 426 */ 427 428 /* tell the change to user processes watching the routing socket. */ 429 static void 430 nd6_rtmsg(int cmd, struct rtentry *rt) 431 { 432 struct rt_addrinfo info; 433 434 bzero((caddr_t)&info, sizeof(info)); 435 info.rti_info[RTAX_DST] = rt_key(rt); 436 info.rti_info[RTAX_GATEWAY] = rt->rt_gateway; 437 info.rti_info[RTAX_NETMASK] = rt_mask(rt); 438 if (rt->rt_ifp) { 439 info.rti_info[RTAX_IFP] = 440 TAILQ_FIRST(&rt->rt_ifp->if_addrlist)->ifa_addr; 441 info.rti_info[RTAX_IFA] = rt->rt_ifa->ifa_addr; 442 } 443 444 rt_missmsg(cmd, &info, rt->rt_flags, 0); 445 } 446 447 void 448 defrouter_addreq(struct nd_defrouter *new) 449 { 450 struct sockaddr_in6 def, mask, gate; 451 struct rtentry *newrt = NULL; 452 int s; 453 int error; 454 455 bzero(&def, sizeof(def)); 456 bzero(&mask, sizeof(mask)); 457 bzero(&gate, sizeof(gate)); 458 459 def.sin6_len = mask.sin6_len = gate.sin6_len = 460 sizeof(struct sockaddr_in6); 461 def.sin6_family = gate.sin6_family = AF_INET6; 462 gate.sin6_addr = new->rtaddr; 463 464 s = splnet(); 465 error = rtrequest(RTM_ADD, (struct sockaddr *)&def, 466 (struct sockaddr *)&gate, (struct sockaddr *)&mask, 467 RTF_GATEWAY, &newrt); 468 if (newrt) { 469 RT_LOCK(newrt); 470 nd6_rtmsg(RTM_ADD, newrt); /* tell user process */ 471 RT_REMREF(newrt); 472 RT_UNLOCK(newrt); 473 } 474 if (error == 0) 475 new->installed = 1; 476 splx(s); 477 return; 478 } 479 480 struct nd_defrouter * 481 defrouter_lookup(struct in6_addr *addr, struct ifnet *ifp) 482 { 483 struct nd_defrouter *dr; 484 485 for (dr = TAILQ_FIRST(&nd_defrouter); dr; 486 dr = TAILQ_NEXT(dr, dr_entry)) { 487 if (dr->ifp == ifp && IN6_ARE_ADDR_EQUAL(addr, &dr->rtaddr)) 488 return (dr); 489 } 490 491 return (NULL); /* search failed */ 492 } 493 494 /* 495 * Remove the default route for a given router. 496 * This is just a subroutine function for defrouter_select(), and should 497 * not be called from anywhere else. 498 */ 499 static void 500 defrouter_delreq(struct nd_defrouter *dr) 501 { 502 struct sockaddr_in6 def, mask, gate; 503 struct rtentry *oldrt = NULL; 504 505 bzero(&def, sizeof(def)); 506 bzero(&mask, sizeof(mask)); 507 bzero(&gate, sizeof(gate)); 508 509 def.sin6_len = mask.sin6_len = gate.sin6_len = 510 sizeof(struct sockaddr_in6); 511 def.sin6_family = gate.sin6_family = AF_INET6; 512 gate.sin6_addr = dr->rtaddr; 513 514 rtrequest(RTM_DELETE, (struct sockaddr *)&def, 515 (struct sockaddr *)&gate, 516 (struct sockaddr *)&mask, RTF_GATEWAY, &oldrt); 517 if (oldrt) { 518 nd6_rtmsg(RTM_DELETE, oldrt); 519 RTFREE(oldrt); 520 } 521 522 dr->installed = 0; 523 } 524 525 /* 526 * remove all default routes from default router list 527 */ 528 void 529 defrouter_reset(void) 530 { 531 struct nd_defrouter *dr; 532 533 for (dr = TAILQ_FIRST(&nd_defrouter); dr; 534 dr = TAILQ_NEXT(dr, dr_entry)) 535 defrouter_delreq(dr); 536 537 /* 538 * XXX should we also nuke any default routers in the kernel, by 539 * going through them by rtalloc1()? 540 */ 541 } 542 543 void 544 defrtrlist_del(struct nd_defrouter *dr) 545 { 546 struct nd_defrouter *deldr = NULL; 547 struct nd_prefix *pr; 548 549 /* 550 * Flush all the routing table entries that use the router 551 * as a next hop. 552 */ 553 if (!ip6_forwarding && ip6_accept_rtadv) /* XXX: better condition? */ 554 rt6_flush(&dr->rtaddr, dr->ifp); 555 556 if (dr->installed) { 557 deldr = dr; 558 defrouter_delreq(dr); 559 } 560 TAILQ_REMOVE(&nd_defrouter, dr, dr_entry); 561 562 /* 563 * Also delete all the pointers to the router in each prefix lists. 564 */ 565 for (pr = nd_prefix.lh_first; pr; pr = pr->ndpr_next) { 566 struct nd_pfxrouter *pfxrtr; 567 if ((pfxrtr = pfxrtr_lookup(pr, dr)) != NULL) 568 pfxrtr_del(pfxrtr); 569 } 570 pfxlist_onlink_check(); 571 572 /* 573 * If the router is the primary one, choose a new one. 574 * Note that defrouter_select() will remove the current gateway 575 * from the routing table. 576 */ 577 if (deldr) 578 defrouter_select(); 579 580 free(dr, M_IP6NDP); 581 } 582 583 /* 584 * Default Router Selection according to Section 6.3.6 of RFC 2461 and 585 * draft-ietf-ipngwg-router-selection: 586 * 1) Routers that are reachable or probably reachable should be preferred. 587 * If we have more than one (probably) reachable router, prefer ones 588 * with the highest router preference. 589 * 2) When no routers on the list are known to be reachable or 590 * probably reachable, routers SHOULD be selected in a round-robin 591 * fashion, regardless of router preference values. 592 * 3) If the Default Router List is empty, assume that all 593 * destinations are on-link. 594 * 595 * We assume nd_defrouter is sorted by router preference value. 596 * Since the code below covers both with and without router preference cases, 597 * we do not need to classify the cases by ifdef. 598 * 599 * At this moment, we do not try to install more than one default router, 600 * even when the multipath routing is available, because we're not sure about 601 * the benefits for stub hosts comparing to the risk of making the code 602 * complicated and the possibility of introducing bugs. 603 */ 604 void 605 defrouter_select(void) 606 { 607 int s = splnet(); 608 struct nd_defrouter *dr, *selected_dr = NULL, *installed_dr = NULL; 609 struct rtentry *rt = NULL; 610 struct llinfo_nd6 *ln = NULL; 611 612 /* 613 * This function should be called only when acting as an autoconfigured 614 * host. Although the remaining part of this function is not effective 615 * if the node is not an autoconfigured host, we explicitly exclude 616 * such cases here for safety. 617 */ 618 if (ip6_forwarding || !ip6_accept_rtadv) { 619 nd6log((LOG_WARNING, 620 "defrouter_select: called unexpectedly (forwarding=%d, " 621 "accept_rtadv=%d)\n", ip6_forwarding, ip6_accept_rtadv)); 622 splx(s); 623 return; 624 } 625 626 /* 627 * Let's handle easy case (3) first: 628 * If default router list is empty, there's nothing to be done. 629 */ 630 if (!TAILQ_FIRST(&nd_defrouter)) { 631 splx(s); 632 return; 633 } 634 635 /* 636 * Search for a (probably) reachable router from the list. 637 * We just pick up the first reachable one (if any), assuming that 638 * the ordering rule of the list described in defrtrlist_update(). 639 */ 640 for (dr = TAILQ_FIRST(&nd_defrouter); dr; 641 dr = TAILQ_NEXT(dr, dr_entry)) { 642 if (selected_dr == NULL && 643 (rt = nd6_lookup(&dr->rtaddr, 0, dr->ifp)) && 644 (ln = (struct llinfo_nd6 *)rt->rt_llinfo) && 645 ND6_IS_LLINFO_PROBREACH(ln)) { 646 selected_dr = dr; 647 } 648 649 if (dr->installed && installed_dr == NULL) 650 installed_dr = dr; 651 else if (dr->installed && installed_dr) { 652 /* this should not happen. warn for diagnosis. */ 653 log(LOG_ERR, "defrouter_select: more than one router" 654 " is installed\n"); 655 } 656 } 657 /* 658 * If none of the default routers was found to be reachable, 659 * round-robin the list regardless of preference. 660 * Otherwise, if we have an installed router, check if the selected 661 * (reachable) router should really be preferred to the installed one. 662 * We only prefer the new router when the old one is not reachable 663 * or when the new one has a really higher preference value. 664 */ 665 if (selected_dr == NULL) { 666 if (installed_dr == NULL || !TAILQ_NEXT(installed_dr, dr_entry)) 667 selected_dr = TAILQ_FIRST(&nd_defrouter); 668 else 669 selected_dr = TAILQ_NEXT(installed_dr, dr_entry); 670 } else if (installed_dr && 671 (rt = nd6_lookup(&installed_dr->rtaddr, 0, installed_dr->ifp)) && 672 (ln = (struct llinfo_nd6 *)rt->rt_llinfo) && 673 ND6_IS_LLINFO_PROBREACH(ln) && 674 rtpref(selected_dr) <= rtpref(installed_dr)) { 675 selected_dr = installed_dr; 676 } 677 678 /* 679 * If the selected router is different than the installed one, 680 * remove the installed router and install the selected one. 681 * Note that the selected router is never NULL here. 682 */ 683 if (installed_dr != selected_dr) { 684 if (installed_dr) 685 defrouter_delreq(installed_dr); 686 defrouter_addreq(selected_dr); 687 } 688 689 splx(s); 690 return; 691 } 692 693 /* 694 * for default router selection 695 * regards router-preference field as a 2-bit signed integer 696 */ 697 static int 698 rtpref(struct nd_defrouter *dr) 699 { 700 switch (dr->flags & ND_RA_FLAG_RTPREF_MASK) { 701 case ND_RA_FLAG_RTPREF_HIGH: 702 return (RTPREF_HIGH); 703 case ND_RA_FLAG_RTPREF_MEDIUM: 704 case ND_RA_FLAG_RTPREF_RSV: 705 return (RTPREF_MEDIUM); 706 case ND_RA_FLAG_RTPREF_LOW: 707 return (RTPREF_LOW); 708 default: 709 /* 710 * This case should never happen. If it did, it would mean a 711 * serious bug of kernel internal. We thus always bark here. 712 * Or, can we even panic? 713 */ 714 log(LOG_ERR, "rtpref: impossible RA flag %x\n", dr->flags); 715 return (RTPREF_INVALID); 716 } 717 /* NOTREACHED */ 718 } 719 720 static struct nd_defrouter * 721 defrtrlist_update(struct nd_defrouter *new) 722 { 723 struct nd_defrouter *dr, *n; 724 int s = splnet(); 725 726 if ((dr = defrouter_lookup(&new->rtaddr, new->ifp)) != NULL) { 727 /* entry exists */ 728 if (new->rtlifetime == 0) { 729 defrtrlist_del(dr); 730 dr = NULL; 731 } else { 732 int oldpref = rtpref(dr); 733 734 /* override */ 735 dr->flags = new->flags; /* xxx flag check */ 736 dr->rtlifetime = new->rtlifetime; 737 dr->expire = new->expire; 738 739 /* 740 * If the preference does not change, there's no need 741 * to sort the entries. 742 */ 743 if (rtpref(new) == oldpref) { 744 splx(s); 745 return (dr); 746 } 747 748 /* 749 * preferred router may be changed, so relocate 750 * this router. 751 * XXX: calling TAILQ_REMOVE directly is a bad manner. 752 * However, since defrtrlist_del() has many side 753 * effects, we intentionally do so here. 754 * defrouter_select() below will handle routing 755 * changes later. 756 */ 757 TAILQ_REMOVE(&nd_defrouter, dr, dr_entry); 758 n = dr; 759 goto insert; 760 } 761 splx(s); 762 return (dr); 763 } 764 765 /* entry does not exist */ 766 if (new->rtlifetime == 0) { 767 splx(s); 768 return (NULL); 769 } 770 771 n = (struct nd_defrouter *)malloc(sizeof(*n), M_IP6NDP, M_NOWAIT); 772 if (n == NULL) { 773 splx(s); 774 return (NULL); 775 } 776 bzero(n, sizeof(*n)); 777 *n = *new; 778 779 insert: 780 /* 781 * Insert the new router in the Default Router List; 782 * The Default Router List should be in the descending order 783 * of router-preferece. Routers with the same preference are 784 * sorted in the arriving time order. 785 */ 786 787 /* insert at the end of the group */ 788 for (dr = TAILQ_FIRST(&nd_defrouter); dr; 789 dr = TAILQ_NEXT(dr, dr_entry)) { 790 if (rtpref(n) > rtpref(dr)) 791 break; 792 } 793 if (dr) 794 TAILQ_INSERT_BEFORE(dr, n, dr_entry); 795 else 796 TAILQ_INSERT_TAIL(&nd_defrouter, n, dr_entry); 797 798 defrouter_select(); 799 800 splx(s); 801 802 return (n); 803 } 804 805 static struct nd_pfxrouter * 806 pfxrtr_lookup(struct nd_prefix *pr, struct nd_defrouter *dr) 807 { 808 struct nd_pfxrouter *search; 809 810 for (search = pr->ndpr_advrtrs.lh_first; search; search = search->pfr_next) { 811 if (search->router == dr) 812 break; 813 } 814 815 return (search); 816 } 817 818 static void 819 pfxrtr_add(struct nd_prefix *pr, struct nd_defrouter *dr) 820 { 821 struct nd_pfxrouter *new; 822 823 new = (struct nd_pfxrouter *)malloc(sizeof(*new), M_IP6NDP, M_NOWAIT); 824 if (new == NULL) 825 return; 826 bzero(new, sizeof(*new)); 827 new->router = dr; 828 829 LIST_INSERT_HEAD(&pr->ndpr_advrtrs, new, pfr_entry); 830 831 pfxlist_onlink_check(); 832 } 833 834 static void 835 pfxrtr_del(struct nd_pfxrouter *pfr) 836 { 837 LIST_REMOVE(pfr, pfr_entry); 838 free(pfr, M_IP6NDP); 839 } 840 841 struct nd_prefix * 842 nd6_prefix_lookup(struct nd_prefixctl *key) 843 { 844 struct nd_prefix *search; 845 846 for (search = nd_prefix.lh_first; search; search = search->ndpr_next) { 847 if (key->ndpr_ifp == search->ndpr_ifp && 848 key->ndpr_plen == search->ndpr_plen && 849 in6_are_prefix_equal(&key->ndpr_prefix.sin6_addr, 850 &search->ndpr_prefix.sin6_addr, key->ndpr_plen)) { 851 break; 852 } 853 } 854 855 return (search); 856 } 857 858 int 859 nd6_prelist_add(struct nd_prefixctl *pr, struct nd_defrouter *dr, 860 struct nd_prefix **newp) 861 { 862 struct nd_prefix *new = NULL; 863 int error = 0; 864 int i, s; 865 char ip6buf[INET6_ADDRSTRLEN]; 866 867 new = (struct nd_prefix *)malloc(sizeof(*new), M_IP6NDP, M_NOWAIT); 868 if (new == NULL) 869 return(ENOMEM); 870 bzero(new, sizeof(*new)); 871 new->ndpr_ifp = pr->ndpr_ifp; 872 new->ndpr_prefix = pr->ndpr_prefix; 873 new->ndpr_plen = pr->ndpr_plen; 874 new->ndpr_vltime = pr->ndpr_vltime; 875 new->ndpr_pltime = pr->ndpr_pltime; 876 new->ndpr_flags = pr->ndpr_flags; 877 if ((error = in6_init_prefix_ltimes(new)) != 0) { 878 free(new, M_IP6NDP); 879 return(error); 880 } 881 new->ndpr_lastupdate = time_second; 882 if (newp != NULL) 883 *newp = new; 884 885 /* initialization */ 886 LIST_INIT(&new->ndpr_advrtrs); 887 in6_prefixlen2mask(&new->ndpr_mask, new->ndpr_plen); 888 /* make prefix in the canonical form */ 889 for (i = 0; i < 4; i++) 890 new->ndpr_prefix.sin6_addr.s6_addr32[i] &= 891 new->ndpr_mask.s6_addr32[i]; 892 893 s = splnet(); 894 /* link ndpr_entry to nd_prefix list */ 895 LIST_INSERT_HEAD(&nd_prefix, new, ndpr_entry); 896 splx(s); 897 898 /* ND_OPT_PI_FLAG_ONLINK processing */ 899 if (new->ndpr_raf_onlink) { 900 int e; 901 902 if ((e = nd6_prefix_onlink(new)) != 0) { 903 nd6log((LOG_ERR, "nd6_prelist_add: failed to make " 904 "the prefix %s/%d on-link on %s (errno=%d)\n", 905 ip6_sprintf(ip6buf, &pr->ndpr_prefix.sin6_addr), 906 pr->ndpr_plen, if_name(pr->ndpr_ifp), e)); 907 /* proceed anyway. XXX: is it correct? */ 908 } 909 } 910 911 if (dr) 912 pfxrtr_add(new, dr); 913 914 return 0; 915 } 916 917 void 918 prelist_remove(struct nd_prefix *pr) 919 { 920 struct nd_pfxrouter *pfr, *next; 921 int e, s; 922 char ip6buf[INET6_ADDRSTRLEN]; 923 924 /* make sure to invalidate the prefix until it is really freed. */ 925 pr->ndpr_vltime = 0; 926 pr->ndpr_pltime = 0; 927 928 /* 929 * Though these flags are now meaningless, we'd rather keep the value 930 * of pr->ndpr_raf_onlink and pr->ndpr_raf_auto not to confuse users 931 * when executing "ndp -p". 932 */ 933 934 if ((pr->ndpr_stateflags & NDPRF_ONLINK) != 0 && 935 (e = nd6_prefix_offlink(pr)) != 0) { 936 nd6log((LOG_ERR, "prelist_remove: failed to make %s/%d offlink " 937 "on %s, errno=%d\n", 938 ip6_sprintf(ip6buf, &pr->ndpr_prefix.sin6_addr), 939 pr->ndpr_plen, if_name(pr->ndpr_ifp), e)); 940 /* what should we do? */ 941 } 942 943 if (pr->ndpr_refcnt > 0) 944 return; /* notice here? */ 945 946 s = splnet(); 947 948 /* unlink ndpr_entry from nd_prefix list */ 949 LIST_REMOVE(pr, ndpr_entry); 950 951 /* free list of routers that adversed the prefix */ 952 for (pfr = pr->ndpr_advrtrs.lh_first; pfr; pfr = next) { 953 next = pfr->pfr_next; 954 955 free(pfr, M_IP6NDP); 956 } 957 splx(s); 958 959 free(pr, M_IP6NDP); 960 961 pfxlist_onlink_check(); 962 } 963 964 /* 965 * dr - may be NULL 966 */ 967 968 static int 969 prelist_update(struct nd_prefixctl *new, struct nd_defrouter *dr, 970 struct mbuf *m, int mcast) 971 { 972 struct in6_ifaddr *ia6 = NULL, *ia6_match = NULL; 973 struct ifaddr *ifa; 974 struct ifnet *ifp = new->ndpr_ifp; 975 struct nd_prefix *pr; 976 int s = splnet(); 977 int error = 0; 978 int newprefix = 0; 979 int auth; 980 struct in6_addrlifetime lt6_tmp; 981 char ip6buf[INET6_ADDRSTRLEN]; 982 983 auth = 0; 984 if (m) { 985 /* 986 * Authenticity for NA consists authentication for 987 * both IP header and IP datagrams, doesn't it ? 988 */ 989 #if defined(M_AUTHIPHDR) && defined(M_AUTHIPDGM) 990 auth = ((m->m_flags & M_AUTHIPHDR) && 991 (m->m_flags & M_AUTHIPDGM)); 992 #endif 993 } 994 995 if ((pr = nd6_prefix_lookup(new)) != NULL) { 996 /* 997 * nd6_prefix_lookup() ensures that pr and new have the same 998 * prefix on a same interface. 999 */ 1000 1001 /* 1002 * Update prefix information. Note that the on-link (L) bit 1003 * and the autonomous (A) bit should NOT be changed from 1 1004 * to 0. 1005 */ 1006 if (new->ndpr_raf_onlink == 1) 1007 pr->ndpr_raf_onlink = 1; 1008 if (new->ndpr_raf_auto == 1) 1009 pr->ndpr_raf_auto = 1; 1010 if (new->ndpr_raf_onlink) { 1011 pr->ndpr_vltime = new->ndpr_vltime; 1012 pr->ndpr_pltime = new->ndpr_pltime; 1013 (void)in6_init_prefix_ltimes(pr); /* XXX error case? */ 1014 pr->ndpr_lastupdate = time_second; 1015 } 1016 1017 if (new->ndpr_raf_onlink && 1018 (pr->ndpr_stateflags & NDPRF_ONLINK) == 0) { 1019 int e; 1020 1021 if ((e = nd6_prefix_onlink(pr)) != 0) { 1022 nd6log((LOG_ERR, 1023 "prelist_update: failed to make " 1024 "the prefix %s/%d on-link on %s " 1025 "(errno=%d)\n", 1026 ip6_sprintf(ip6buf, 1027 &pr->ndpr_prefix.sin6_addr), 1028 pr->ndpr_plen, if_name(pr->ndpr_ifp), e)); 1029 /* proceed anyway. XXX: is it correct? */ 1030 } 1031 } 1032 1033 if (dr && pfxrtr_lookup(pr, dr) == NULL) 1034 pfxrtr_add(pr, dr); 1035 } else { 1036 struct nd_prefix *newpr = NULL; 1037 1038 newprefix = 1; 1039 1040 if (new->ndpr_vltime == 0) 1041 goto end; 1042 if (new->ndpr_raf_onlink == 0 && new->ndpr_raf_auto == 0) 1043 goto end; 1044 1045 error = nd6_prelist_add(new, dr, &newpr); 1046 if (error != 0 || newpr == NULL) { 1047 nd6log((LOG_NOTICE, "prelist_update: " 1048 "nd6_prelist_add failed for %s/%d on %s " 1049 "errno=%d, returnpr=%p\n", 1050 ip6_sprintf(ip6buf, &new->ndpr_prefix.sin6_addr), 1051 new->ndpr_plen, if_name(new->ndpr_ifp), 1052 error, newpr)); 1053 goto end; /* we should just give up in this case. */ 1054 } 1055 1056 /* 1057 * XXX: from the ND point of view, we can ignore a prefix 1058 * with the on-link bit being zero. However, we need a 1059 * prefix structure for references from autoconfigured 1060 * addresses. Thus, we explicitly make sure that the prefix 1061 * itself expires now. 1062 */ 1063 if (newpr->ndpr_raf_onlink == 0) { 1064 newpr->ndpr_vltime = 0; 1065 newpr->ndpr_pltime = 0; 1066 in6_init_prefix_ltimes(newpr); 1067 } 1068 1069 pr = newpr; 1070 } 1071 1072 /* 1073 * Address autoconfiguration based on Section 5.5.3 of RFC 2462. 1074 * Note that pr must be non NULL at this point. 1075 */ 1076 1077 /* 5.5.3 (a). Ignore the prefix without the A bit set. */ 1078 if (!new->ndpr_raf_auto) 1079 goto end; 1080 1081 /* 1082 * 5.5.3 (b). the link-local prefix should have been ignored in 1083 * nd6_ra_input. 1084 */ 1085 1086 /* 5.5.3 (c). Consistency check on lifetimes: pltime <= vltime. */ 1087 if (new->ndpr_pltime > new->ndpr_vltime) { 1088 error = EINVAL; /* XXX: won't be used */ 1089 goto end; 1090 } 1091 1092 /* 1093 * 5.5.3 (d). If the prefix advertised is not equal to the prefix of 1094 * an address configured by stateless autoconfiguration already in the 1095 * list of addresses associated with the interface, and the Valid 1096 * Lifetime is not 0, form an address. We first check if we have 1097 * a matching prefix. 1098 * Note: we apply a clarification in rfc2462bis-02 here. We only 1099 * consider autoconfigured addresses while RFC2462 simply said 1100 * "address". 1101 */ 1102 TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) { 1103 struct in6_ifaddr *ifa6; 1104 u_int32_t remaininglifetime; 1105 1106 if (ifa->ifa_addr->sa_family != AF_INET6) 1107 continue; 1108 1109 ifa6 = (struct in6_ifaddr *)ifa; 1110 1111 /* 1112 * We only consider autoconfigured addresses as per rfc2462bis. 1113 */ 1114 if (!(ifa6->ia6_flags & IN6_IFF_AUTOCONF)) 1115 continue; 1116 1117 /* 1118 * Spec is not clear here, but I believe we should concentrate 1119 * on unicast (i.e. not anycast) addresses. 1120 * XXX: other ia6_flags? detached or duplicated? 1121 */ 1122 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0) 1123 continue; 1124 1125 /* 1126 * Ignore the address if it is not associated with a prefix 1127 * or is associated with a prefix that is different from this 1128 * one. (pr is never NULL here) 1129 */ 1130 if (ifa6->ia6_ndpr != pr) 1131 continue; 1132 1133 if (ia6_match == NULL) /* remember the first one */ 1134 ia6_match = ifa6; 1135 1136 /* 1137 * An already autoconfigured address matched. Now that we 1138 * are sure there is at least one matched address, we can 1139 * proceed to 5.5.3. (e): update the lifetimes according to the 1140 * "two hours" rule and the privacy extension. 1141 * We apply some clarifications in rfc2462bis: 1142 * - use remaininglifetime instead of storedlifetime as a 1143 * variable name 1144 * - remove the dead code in the "two-hour" rule 1145 */ 1146 #define TWOHOUR (120*60) 1147 lt6_tmp = ifa6->ia6_lifetime; 1148 1149 if (lt6_tmp.ia6t_vltime == ND6_INFINITE_LIFETIME) 1150 remaininglifetime = ND6_INFINITE_LIFETIME; 1151 else if (time_second - ifa6->ia6_updatetime > 1152 lt6_tmp.ia6t_vltime) { 1153 /* 1154 * The case of "invalid" address. We should usually 1155 * not see this case. 1156 */ 1157 remaininglifetime = 0; 1158 } else 1159 remaininglifetime = lt6_tmp.ia6t_vltime - 1160 (time_second - ifa6->ia6_updatetime); 1161 1162 /* when not updating, keep the current stored lifetime. */ 1163 lt6_tmp.ia6t_vltime = remaininglifetime; 1164 1165 if (TWOHOUR < new->ndpr_vltime || 1166 remaininglifetime < new->ndpr_vltime) { 1167 lt6_tmp.ia6t_vltime = new->ndpr_vltime; 1168 } else if (remaininglifetime <= TWOHOUR) { 1169 if (auth) { 1170 lt6_tmp.ia6t_vltime = new->ndpr_vltime; 1171 } 1172 } else { 1173 /* 1174 * new->ndpr_vltime <= TWOHOUR && 1175 * TWOHOUR < remaininglifetime 1176 */ 1177 lt6_tmp.ia6t_vltime = TWOHOUR; 1178 } 1179 1180 /* The 2 hour rule is not imposed for preferred lifetime. */ 1181 lt6_tmp.ia6t_pltime = new->ndpr_pltime; 1182 1183 in6_init_address_ltimes(pr, <6_tmp); 1184 1185 /* 1186 * We need to treat lifetimes for temporary addresses 1187 * differently, according to 1188 * draft-ietf-ipv6-privacy-addrs-v2-01.txt 3.3 (1); 1189 * we only update the lifetimes when they are in the maximum 1190 * intervals. 1191 */ 1192 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0) { 1193 u_int32_t maxvltime, maxpltime; 1194 1195 if (ip6_temp_valid_lifetime > 1196 (u_int32_t)((time_second - ifa6->ia6_createtime) + 1197 ip6_desync_factor)) { 1198 maxvltime = ip6_temp_valid_lifetime - 1199 (time_second - ifa6->ia6_createtime) - 1200 ip6_desync_factor; 1201 } else 1202 maxvltime = 0; 1203 if (ip6_temp_preferred_lifetime > 1204 (u_int32_t)((time_second - ifa6->ia6_createtime) + 1205 ip6_desync_factor)) { 1206 maxpltime = ip6_temp_preferred_lifetime - 1207 (time_second - ifa6->ia6_createtime) - 1208 ip6_desync_factor; 1209 } else 1210 maxpltime = 0; 1211 1212 if (lt6_tmp.ia6t_vltime == ND6_INFINITE_LIFETIME || 1213 lt6_tmp.ia6t_vltime > maxvltime) { 1214 lt6_tmp.ia6t_vltime = maxvltime; 1215 } 1216 if (lt6_tmp.ia6t_pltime == ND6_INFINITE_LIFETIME || 1217 lt6_tmp.ia6t_pltime > maxpltime) { 1218 lt6_tmp.ia6t_pltime = maxpltime; 1219 } 1220 } 1221 ifa6->ia6_lifetime = lt6_tmp; 1222 ifa6->ia6_updatetime = time_second; 1223 } 1224 if (ia6_match == NULL && new->ndpr_vltime) { 1225 int ifidlen; 1226 1227 /* 1228 * 5.5.3 (d) (continued) 1229 * No address matched and the valid lifetime is non-zero. 1230 * Create a new address. 1231 */ 1232 1233 /* 1234 * Prefix Length check: 1235 * If the sum of the prefix length and interface identifier 1236 * length does not equal 128 bits, the Prefix Information 1237 * option MUST be ignored. The length of the interface 1238 * identifier is defined in a separate link-type specific 1239 * document. 1240 */ 1241 ifidlen = in6_if2idlen(ifp); 1242 if (ifidlen < 0) { 1243 /* this should not happen, so we always log it. */ 1244 log(LOG_ERR, "prelist_update: IFID undefined (%s)\n", 1245 if_name(ifp)); 1246 goto end; 1247 } 1248 if (ifidlen + pr->ndpr_plen != 128) { 1249 nd6log((LOG_INFO, 1250 "prelist_update: invalid prefixlen " 1251 "%d for %s, ignored\n", 1252 pr->ndpr_plen, if_name(ifp))); 1253 goto end; 1254 } 1255 1256 if ((ia6 = in6_ifadd(new, mcast)) != NULL) { 1257 /* 1258 * note that we should use pr (not new) for reference. 1259 */ 1260 pr->ndpr_refcnt++; 1261 ia6->ia6_ndpr = pr; 1262 1263 /* 1264 * RFC 3041 3.3 (2). 1265 * When a new public address is created as described 1266 * in RFC2462, also create a new temporary address. 1267 * 1268 * RFC 3041 3.5. 1269 * When an interface connects to a new link, a new 1270 * randomized interface identifier should be generated 1271 * immediately together with a new set of temporary 1272 * addresses. Thus, we specifiy 1 as the 2nd arg of 1273 * in6_tmpifadd(). 1274 */ 1275 if (ip6_use_tempaddr) { 1276 int e; 1277 if ((e = in6_tmpifadd(ia6, 1, 1)) != 0) { 1278 nd6log((LOG_NOTICE, "prelist_update: " 1279 "failed to create a temporary " 1280 "address, errno=%d\n", 1281 e)); 1282 } 1283 } 1284 1285 /* 1286 * A newly added address might affect the status 1287 * of other addresses, so we check and update it. 1288 * XXX: what if address duplication happens? 1289 */ 1290 pfxlist_onlink_check(); 1291 } else { 1292 /* just set an error. do not bark here. */ 1293 error = EADDRNOTAVAIL; /* XXX: might be unused. */ 1294 } 1295 } 1296 1297 end: 1298 splx(s); 1299 return error; 1300 } 1301 1302 /* 1303 * A supplement function used in the on-link detection below; 1304 * detect if a given prefix has a (probably) reachable advertising router. 1305 * XXX: lengthy function name... 1306 */ 1307 static struct nd_pfxrouter * 1308 find_pfxlist_reachable_router(struct nd_prefix *pr) 1309 { 1310 struct nd_pfxrouter *pfxrtr; 1311 struct rtentry *rt; 1312 struct llinfo_nd6 *ln; 1313 1314 for (pfxrtr = LIST_FIRST(&pr->ndpr_advrtrs); pfxrtr; 1315 pfxrtr = LIST_NEXT(pfxrtr, pfr_entry)) { 1316 if ((rt = nd6_lookup(&pfxrtr->router->rtaddr, 0, 1317 pfxrtr->router->ifp)) && 1318 (ln = (struct llinfo_nd6 *)rt->rt_llinfo) && 1319 ND6_IS_LLINFO_PROBREACH(ln)) 1320 break; /* found */ 1321 } 1322 1323 return (pfxrtr); 1324 } 1325 1326 /* 1327 * Check if each prefix in the prefix list has at least one available router 1328 * that advertised the prefix (a router is "available" if its neighbor cache 1329 * entry is reachable or probably reachable). 1330 * If the check fails, the prefix may be off-link, because, for example, 1331 * we have moved from the network but the lifetime of the prefix has not 1332 * expired yet. So we should not use the prefix if there is another prefix 1333 * that has an available router. 1334 * But, if there is no prefix that has an available router, we still regards 1335 * all the prefixes as on-link. This is because we can't tell if all the 1336 * routers are simply dead or if we really moved from the network and there 1337 * is no router around us. 1338 */ 1339 void 1340 pfxlist_onlink_check() 1341 { 1342 struct nd_prefix *pr; 1343 struct in6_ifaddr *ifa; 1344 struct nd_defrouter *dr; 1345 struct nd_pfxrouter *pfxrtr = NULL; 1346 1347 /* 1348 * Check if there is a prefix that has a reachable advertising 1349 * router. 1350 */ 1351 for (pr = nd_prefix.lh_first; pr; pr = pr->ndpr_next) { 1352 if (pr->ndpr_raf_onlink && find_pfxlist_reachable_router(pr)) 1353 break; 1354 } 1355 1356 /* 1357 * If we have no such prefix, check whether we still have a router 1358 * that does not advertise any prefixes. 1359 */ 1360 if (pr == NULL) { 1361 for (dr = TAILQ_FIRST(&nd_defrouter); dr; 1362 dr = TAILQ_NEXT(dr, dr_entry)) { 1363 struct nd_prefix *pr0; 1364 1365 for (pr0 = nd_prefix.lh_first; pr0; 1366 pr0 = pr0->ndpr_next) { 1367 if ((pfxrtr = pfxrtr_lookup(pr0, dr)) != NULL) 1368 break; 1369 } 1370 if (pfxrtr != NULL) 1371 break; 1372 } 1373 } 1374 if (pr != NULL || (TAILQ_FIRST(&nd_defrouter) && pfxrtr == NULL)) { 1375 /* 1376 * There is at least one prefix that has a reachable router, 1377 * or at least a router which probably does not advertise 1378 * any prefixes. The latter would be the case when we move 1379 * to a new link where we have a router that does not provide 1380 * prefixes and we configure an address by hand. 1381 * Detach prefixes which have no reachable advertising 1382 * router, and attach other prefixes. 1383 */ 1384 for (pr = nd_prefix.lh_first; pr; pr = pr->ndpr_next) { 1385 /* XXX: a link-local prefix should never be detached */ 1386 if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr)) 1387 continue; 1388 1389 /* 1390 * we aren't interested in prefixes without the L bit 1391 * set. 1392 */ 1393 if (pr->ndpr_raf_onlink == 0) 1394 continue; 1395 1396 if ((pr->ndpr_stateflags & NDPRF_DETACHED) == 0 && 1397 find_pfxlist_reachable_router(pr) == NULL) 1398 pr->ndpr_stateflags |= NDPRF_DETACHED; 1399 if ((pr->ndpr_stateflags & NDPRF_DETACHED) != 0 && 1400 find_pfxlist_reachable_router(pr) != 0) 1401 pr->ndpr_stateflags &= ~NDPRF_DETACHED; 1402 } 1403 } else { 1404 /* there is no prefix that has a reachable router */ 1405 for (pr = nd_prefix.lh_first; pr; pr = pr->ndpr_next) { 1406 if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr)) 1407 continue; 1408 1409 if (pr->ndpr_raf_onlink == 0) 1410 continue; 1411 1412 if ((pr->ndpr_stateflags & NDPRF_DETACHED) != 0) 1413 pr->ndpr_stateflags &= ~NDPRF_DETACHED; 1414 } 1415 } 1416 1417 /* 1418 * Remove each interface route associated with a (just) detached 1419 * prefix, and reinstall the interface route for a (just) attached 1420 * prefix. Note that all attempt of reinstallation does not 1421 * necessarily success, when a same prefix is shared among multiple 1422 * interfaces. Such cases will be handled in nd6_prefix_onlink, 1423 * so we don't have to care about them. 1424 */ 1425 for (pr = nd_prefix.lh_first; pr; pr = pr->ndpr_next) { 1426 int e; 1427 char ip6buf[INET6_ADDRSTRLEN]; 1428 1429 if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr)) 1430 continue; 1431 1432 if (pr->ndpr_raf_onlink == 0) 1433 continue; 1434 1435 if ((pr->ndpr_stateflags & NDPRF_DETACHED) != 0 && 1436 (pr->ndpr_stateflags & NDPRF_ONLINK) != 0) { 1437 if ((e = nd6_prefix_offlink(pr)) != 0) { 1438 nd6log((LOG_ERR, 1439 "pfxlist_onlink_check: failed to " 1440 "make %s/%d offlink, errno=%d\n", 1441 ip6_sprintf(ip6buf, 1442 &pr->ndpr_prefix.sin6_addr), 1443 pr->ndpr_plen, e)); 1444 } 1445 } 1446 if ((pr->ndpr_stateflags & NDPRF_DETACHED) == 0 && 1447 (pr->ndpr_stateflags & NDPRF_ONLINK) == 0 && 1448 pr->ndpr_raf_onlink) { 1449 if ((e = nd6_prefix_onlink(pr)) != 0) { 1450 nd6log((LOG_ERR, 1451 "pfxlist_onlink_check: failed to " 1452 "make %s/%d onlink, errno=%d\n", 1453 ip6_sprintf(ip6buf, 1454 &pr->ndpr_prefix.sin6_addr), 1455 pr->ndpr_plen, e)); 1456 } 1457 } 1458 } 1459 1460 /* 1461 * Changes on the prefix status might affect address status as well. 1462 * Make sure that all addresses derived from an attached prefix are 1463 * attached, and that all addresses derived from a detached prefix are 1464 * detached. Note, however, that a manually configured address should 1465 * always be attached. 1466 * The precise detection logic is same as the one for prefixes. 1467 */ 1468 for (ifa = in6_ifaddr; ifa; ifa = ifa->ia_next) { 1469 if (!(ifa->ia6_flags & IN6_IFF_AUTOCONF)) 1470 continue; 1471 1472 if (ifa->ia6_ndpr == NULL) { 1473 /* 1474 * This can happen when we first configure the address 1475 * (i.e. the address exists, but the prefix does not). 1476 * XXX: complicated relationships... 1477 */ 1478 continue; 1479 } 1480 1481 if (find_pfxlist_reachable_router(ifa->ia6_ndpr)) 1482 break; 1483 } 1484 if (ifa) { 1485 for (ifa = in6_ifaddr; ifa; ifa = ifa->ia_next) { 1486 if ((ifa->ia6_flags & IN6_IFF_AUTOCONF) == 0) 1487 continue; 1488 1489 if (ifa->ia6_ndpr == NULL) /* XXX: see above. */ 1490 continue; 1491 1492 if (find_pfxlist_reachable_router(ifa->ia6_ndpr)) { 1493 if (ifa->ia6_flags & IN6_IFF_DETACHED) { 1494 ifa->ia6_flags &= ~IN6_IFF_DETACHED; 1495 ifa->ia6_flags |= IN6_IFF_TENTATIVE; 1496 nd6_dad_start((struct ifaddr *)ifa, 0); 1497 } 1498 } else { 1499 ifa->ia6_flags |= IN6_IFF_DETACHED; 1500 } 1501 } 1502 } 1503 else { 1504 for (ifa = in6_ifaddr; ifa; ifa = ifa->ia_next) { 1505 if ((ifa->ia6_flags & IN6_IFF_AUTOCONF) == 0) 1506 continue; 1507 1508 if (ifa->ia6_flags & IN6_IFF_DETACHED) { 1509 ifa->ia6_flags &= ~IN6_IFF_DETACHED; 1510 ifa->ia6_flags |= IN6_IFF_TENTATIVE; 1511 /* Do we need a delay in this case? */ 1512 nd6_dad_start((struct ifaddr *)ifa, 0); 1513 } 1514 } 1515 } 1516 } 1517 1518 int 1519 nd6_prefix_onlink(struct nd_prefix *pr) 1520 { 1521 struct ifaddr *ifa; 1522 struct ifnet *ifp = pr->ndpr_ifp; 1523 struct sockaddr_in6 mask6; 1524 struct nd_prefix *opr; 1525 u_long rtflags; 1526 int error = 0; 1527 struct rtentry *rt = NULL; 1528 char ip6buf[INET6_ADDRSTRLEN]; 1529 1530 /* sanity check */ 1531 if ((pr->ndpr_stateflags & NDPRF_ONLINK) != 0) { 1532 nd6log((LOG_ERR, 1533 "nd6_prefix_onlink: %s/%d is already on-link\n", 1534 ip6_sprintf(ip6buf, &pr->ndpr_prefix.sin6_addr), 1535 pr->ndpr_plen)); 1536 return (EEXIST); 1537 } 1538 1539 /* 1540 * Add the interface route associated with the prefix. Before 1541 * installing the route, check if there's the same prefix on another 1542 * interface, and the prefix has already installed the interface route. 1543 * Although such a configuration is expected to be rare, we explicitly 1544 * allow it. 1545 */ 1546 for (opr = nd_prefix.lh_first; opr; opr = opr->ndpr_next) { 1547 if (opr == pr) 1548 continue; 1549 1550 if ((opr->ndpr_stateflags & NDPRF_ONLINK) == 0) 1551 continue; 1552 1553 if (opr->ndpr_plen == pr->ndpr_plen && 1554 in6_are_prefix_equal(&pr->ndpr_prefix.sin6_addr, 1555 &opr->ndpr_prefix.sin6_addr, pr->ndpr_plen)) 1556 return (0); 1557 } 1558 1559 /* 1560 * We prefer link-local addresses as the associated interface address. 1561 */ 1562 /* search for a link-local addr */ 1563 ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp, 1564 IN6_IFF_NOTREADY | IN6_IFF_ANYCAST); 1565 if (ifa == NULL) { 1566 /* XXX: freebsd does not have ifa_ifwithaf */ 1567 TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) { 1568 if (ifa->ifa_addr->sa_family == AF_INET6) 1569 break; 1570 } 1571 /* should we care about ia6_flags? */ 1572 } 1573 if (ifa == NULL) { 1574 /* 1575 * This can still happen, when, for example, we receive an RA 1576 * containing a prefix with the L bit set and the A bit clear, 1577 * after removing all IPv6 addresses on the receiving 1578 * interface. This should, of course, be rare though. 1579 */ 1580 nd6log((LOG_NOTICE, 1581 "nd6_prefix_onlink: failed to find any ifaddr" 1582 " to add route for a prefix(%s/%d) on %s\n", 1583 ip6_sprintf(ip6buf, &pr->ndpr_prefix.sin6_addr), 1584 pr->ndpr_plen, if_name(ifp))); 1585 return (0); 1586 } 1587 1588 /* 1589 * in6_ifinit() sets nd6_rtrequest to ifa_rtrequest for all ifaddrs. 1590 * ifa->ifa_rtrequest = nd6_rtrequest; 1591 */ 1592 bzero(&mask6, sizeof(mask6)); 1593 mask6.sin6_len = sizeof(mask6); 1594 mask6.sin6_addr = pr->ndpr_mask; 1595 rtflags = ifa->ifa_flags | RTF_CLONING | RTF_UP; 1596 if (nd6_need_cache(ifp)) { 1597 /* explicitly set in case ifa_flags does not set the flag. */ 1598 rtflags |= RTF_CLONING; 1599 } else { 1600 /* 1601 * explicitly clear the cloning bit in case ifa_flags sets it. 1602 */ 1603 rtflags &= ~RTF_CLONING; 1604 } 1605 error = rtrequest(RTM_ADD, (struct sockaddr *)&pr->ndpr_prefix, 1606 ifa->ifa_addr, (struct sockaddr *)&mask6, rtflags, &rt); 1607 if (error == 0) { 1608 if (rt != NULL) /* this should be non NULL, though */ 1609 nd6_rtmsg(RTM_ADD, rt); 1610 pr->ndpr_stateflags |= NDPRF_ONLINK; 1611 } else { 1612 char ip6bufg[INET6_ADDRSTRLEN], ip6bufm[INET6_ADDRSTRLEN]; 1613 nd6log((LOG_ERR, "nd6_prefix_onlink: failed to add route for a" 1614 " prefix (%s/%d) on %s, gw=%s, mask=%s, flags=%lx " 1615 "errno = %d\n", 1616 ip6_sprintf(ip6buf, &pr->ndpr_prefix.sin6_addr), 1617 pr->ndpr_plen, if_name(ifp), 1618 ip6_sprintf(ip6bufg, &((struct sockaddr_in6 *)ifa->ifa_addr)->sin6_addr), 1619 ip6_sprintf(ip6bufm, &mask6.sin6_addr), rtflags, error)); 1620 } 1621 1622 if (rt != NULL) { 1623 RT_LOCK(rt); 1624 RT_REMREF(rt); 1625 RT_UNLOCK(rt); 1626 } 1627 1628 return (error); 1629 } 1630 1631 int 1632 nd6_prefix_offlink(struct nd_prefix *pr) 1633 { 1634 int error = 0; 1635 struct ifnet *ifp = pr->ndpr_ifp; 1636 struct nd_prefix *opr; 1637 struct sockaddr_in6 sa6, mask6; 1638 struct rtentry *rt = NULL; 1639 char ip6buf[INET6_ADDRSTRLEN]; 1640 1641 /* sanity check */ 1642 if ((pr->ndpr_stateflags & NDPRF_ONLINK) == 0) { 1643 nd6log((LOG_ERR, 1644 "nd6_prefix_offlink: %s/%d is already off-link\n", 1645 ip6_sprintf(ip6buf, &pr->ndpr_prefix.sin6_addr), 1646 pr->ndpr_plen)); 1647 return (EEXIST); 1648 } 1649 1650 bzero(&sa6, sizeof(sa6)); 1651 sa6.sin6_family = AF_INET6; 1652 sa6.sin6_len = sizeof(sa6); 1653 bcopy(&pr->ndpr_prefix.sin6_addr, &sa6.sin6_addr, 1654 sizeof(struct in6_addr)); 1655 bzero(&mask6, sizeof(mask6)); 1656 mask6.sin6_family = AF_INET6; 1657 mask6.sin6_len = sizeof(sa6); 1658 bcopy(&pr->ndpr_mask, &mask6.sin6_addr, sizeof(struct in6_addr)); 1659 error = rtrequest(RTM_DELETE, (struct sockaddr *)&sa6, NULL, 1660 (struct sockaddr *)&mask6, 0, &rt); 1661 if (error == 0) { 1662 pr->ndpr_stateflags &= ~NDPRF_ONLINK; 1663 1664 /* report the route deletion to the routing socket. */ 1665 if (rt != NULL) 1666 nd6_rtmsg(RTM_DELETE, rt); 1667 1668 /* 1669 * There might be the same prefix on another interface, 1670 * the prefix which could not be on-link just because we have 1671 * the interface route (see comments in nd6_prefix_onlink). 1672 * If there's one, try to make the prefix on-link on the 1673 * interface. 1674 */ 1675 for (opr = nd_prefix.lh_first; opr; opr = opr->ndpr_next) { 1676 if (opr == pr) 1677 continue; 1678 1679 if ((opr->ndpr_stateflags & NDPRF_ONLINK) != 0) 1680 continue; 1681 1682 /* 1683 * KAME specific: detached prefixes should not be 1684 * on-link. 1685 */ 1686 if ((opr->ndpr_stateflags & NDPRF_DETACHED) != 0) 1687 continue; 1688 1689 if (opr->ndpr_plen == pr->ndpr_plen && 1690 in6_are_prefix_equal(&pr->ndpr_prefix.sin6_addr, 1691 &opr->ndpr_prefix.sin6_addr, pr->ndpr_plen)) { 1692 int e; 1693 1694 if ((e = nd6_prefix_onlink(opr)) != 0) { 1695 nd6log((LOG_ERR, 1696 "nd6_prefix_offlink: failed to " 1697 "recover a prefix %s/%d from %s " 1698 "to %s (errno = %d)\n", 1699 ip6_sprintf(ip6buf, 1700 &opr->ndpr_prefix.sin6_addr), 1701 opr->ndpr_plen, if_name(ifp), 1702 if_name(opr->ndpr_ifp), e)); 1703 } 1704 } 1705 } 1706 } else { 1707 /* XXX: can we still set the NDPRF_ONLINK flag? */ 1708 nd6log((LOG_ERR, 1709 "nd6_prefix_offlink: failed to delete route: " 1710 "%s/%d on %s (errno = %d)\n", 1711 ip6_sprintf(ip6buf, &sa6.sin6_addr), pr->ndpr_plen, 1712 if_name(ifp), error)); 1713 } 1714 1715 if (rt != NULL) { 1716 RTFREE(rt); 1717 } 1718 1719 return (error); 1720 } 1721 1722 static struct in6_ifaddr * 1723 in6_ifadd(struct nd_prefixctl *pr, int mcast) 1724 { 1725 struct ifnet *ifp = pr->ndpr_ifp; 1726 struct ifaddr *ifa; 1727 struct in6_aliasreq ifra; 1728 struct in6_ifaddr *ia, *ib; 1729 int error, plen0; 1730 struct in6_addr mask; 1731 int prefixlen = pr->ndpr_plen; 1732 int updateflags; 1733 char ip6buf[INET6_ADDRSTRLEN]; 1734 1735 in6_prefixlen2mask(&mask, prefixlen); 1736 1737 /* 1738 * find a link-local address (will be interface ID). 1739 * Is it really mandatory? Theoretically, a global or a site-local 1740 * address can be configured without a link-local address, if we 1741 * have a unique interface identifier... 1742 * 1743 * it is not mandatory to have a link-local address, we can generate 1744 * interface identifier on the fly. we do this because: 1745 * (1) it should be the easiest way to find interface identifier. 1746 * (2) RFC2462 5.4 suggesting the use of the same interface identifier 1747 * for multiple addresses on a single interface, and possible shortcut 1748 * of DAD. we omitted DAD for this reason in the past. 1749 * (3) a user can prevent autoconfiguration of global address 1750 * by removing link-local address by hand (this is partly because we 1751 * don't have other way to control the use of IPv6 on an interface. 1752 * this has been our design choice - cf. NRL's "ifconfig auto"). 1753 * (4) it is easier to manage when an interface has addresses 1754 * with the same interface identifier, than to have multiple addresses 1755 * with different interface identifiers. 1756 */ 1757 ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp, 0); /* 0 is OK? */ 1758 if (ifa) 1759 ib = (struct in6_ifaddr *)ifa; 1760 else 1761 return NULL; 1762 1763 /* prefixlen + ifidlen must be equal to 128 */ 1764 plen0 = in6_mask2len(&ib->ia_prefixmask.sin6_addr, NULL); 1765 if (prefixlen != plen0) { 1766 nd6log((LOG_INFO, "in6_ifadd: wrong prefixlen for %s " 1767 "(prefix=%d ifid=%d)\n", 1768 if_name(ifp), prefixlen, 128 - plen0)); 1769 return NULL; 1770 } 1771 1772 /* make ifaddr */ 1773 1774 bzero(&ifra, sizeof(ifra)); 1775 /* 1776 * in6_update_ifa() does not use ifra_name, but we accurately set it 1777 * for safety. 1778 */ 1779 strncpy(ifra.ifra_name, if_name(ifp), sizeof(ifra.ifra_name)); 1780 ifra.ifra_addr.sin6_family = AF_INET6; 1781 ifra.ifra_addr.sin6_len = sizeof(struct sockaddr_in6); 1782 /* prefix */ 1783 ifra.ifra_addr.sin6_addr = pr->ndpr_prefix.sin6_addr; 1784 ifra.ifra_addr.sin6_addr.s6_addr32[0] &= mask.s6_addr32[0]; 1785 ifra.ifra_addr.sin6_addr.s6_addr32[1] &= mask.s6_addr32[1]; 1786 ifra.ifra_addr.sin6_addr.s6_addr32[2] &= mask.s6_addr32[2]; 1787 ifra.ifra_addr.sin6_addr.s6_addr32[3] &= mask.s6_addr32[3]; 1788 1789 /* interface ID */ 1790 ifra.ifra_addr.sin6_addr.s6_addr32[0] |= 1791 (ib->ia_addr.sin6_addr.s6_addr32[0] & ~mask.s6_addr32[0]); 1792 ifra.ifra_addr.sin6_addr.s6_addr32[1] |= 1793 (ib->ia_addr.sin6_addr.s6_addr32[1] & ~mask.s6_addr32[1]); 1794 ifra.ifra_addr.sin6_addr.s6_addr32[2] |= 1795 (ib->ia_addr.sin6_addr.s6_addr32[2] & ~mask.s6_addr32[2]); 1796 ifra.ifra_addr.sin6_addr.s6_addr32[3] |= 1797 (ib->ia_addr.sin6_addr.s6_addr32[3] & ~mask.s6_addr32[3]); 1798 1799 /* new prefix mask. */ 1800 ifra.ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6); 1801 ifra.ifra_prefixmask.sin6_family = AF_INET6; 1802 bcopy(&mask, &ifra.ifra_prefixmask.sin6_addr, 1803 sizeof(ifra.ifra_prefixmask.sin6_addr)); 1804 1805 /* lifetimes. */ 1806 ifra.ifra_lifetime.ia6t_vltime = pr->ndpr_vltime; 1807 ifra.ifra_lifetime.ia6t_pltime = pr->ndpr_pltime; 1808 1809 /* XXX: scope zone ID? */ 1810 1811 ifra.ifra_flags |= IN6_IFF_AUTOCONF; /* obey autoconf */ 1812 1813 /* 1814 * Make sure that we do not have this address already. This should 1815 * usually not happen, but we can still see this case, e.g., if we 1816 * have manually configured the exact address to be configured. 1817 */ 1818 if (in6ifa_ifpwithaddr(ifp, &ifra.ifra_addr.sin6_addr) != NULL) { 1819 /* this should be rare enough to make an explicit log */ 1820 log(LOG_INFO, "in6_ifadd: %s is already configured\n", 1821 ip6_sprintf(ip6buf, &ifra.ifra_addr.sin6_addr)); 1822 return (NULL); 1823 } 1824 1825 /* 1826 * Allocate ifaddr structure, link into chain, etc. 1827 * If we are going to create a new address upon receiving a multicasted 1828 * RA, we need to impose a random delay before starting DAD. 1829 * [draft-ietf-ipv6-rfc2462bis-02.txt, Section 5.4.2] 1830 */ 1831 updateflags = 0; 1832 if (mcast) 1833 updateflags |= IN6_IFAUPDATE_DADDELAY; 1834 if ((error = in6_update_ifa(ifp, &ifra, NULL, updateflags)) != 0) { 1835 nd6log((LOG_ERR, 1836 "in6_ifadd: failed to make ifaddr %s on %s (errno=%d)\n", 1837 ip6_sprintf(ip6buf, &ifra.ifra_addr.sin6_addr), 1838 if_name(ifp), error)); 1839 return (NULL); /* ifaddr must not have been allocated. */ 1840 } 1841 1842 ia = in6ifa_ifpwithaddr(ifp, &ifra.ifra_addr.sin6_addr); 1843 1844 return (ia); /* this is always non-NULL */ 1845 } 1846 1847 /* 1848 * ia0 - corresponding public address 1849 */ 1850 int 1851 in6_tmpifadd(const struct in6_ifaddr *ia0, int forcegen, int delay) 1852 { 1853 struct ifnet *ifp = ia0->ia_ifa.ifa_ifp; 1854 struct in6_ifaddr *newia, *ia; 1855 struct in6_aliasreq ifra; 1856 int i, error; 1857 int trylimit = 3; /* XXX: adhoc value */ 1858 int updateflags; 1859 u_int32_t randid[2]; 1860 time_t vltime0, pltime0; 1861 1862 bzero(&ifra, sizeof(ifra)); 1863 strncpy(ifra.ifra_name, if_name(ifp), sizeof(ifra.ifra_name)); 1864 ifra.ifra_addr = ia0->ia_addr; 1865 /* copy prefix mask */ 1866 ifra.ifra_prefixmask = ia0->ia_prefixmask; 1867 /* clear the old IFID */ 1868 for (i = 0; i < 4; i++) { 1869 ifra.ifra_addr.sin6_addr.s6_addr32[i] &= 1870 ifra.ifra_prefixmask.sin6_addr.s6_addr32[i]; 1871 } 1872 1873 again: 1874 if (in6_get_tmpifid(ifp, (u_int8_t *)randid, 1875 (const u_int8_t *)&ia0->ia_addr.sin6_addr.s6_addr[8], forcegen)) { 1876 nd6log((LOG_NOTICE, "in6_tmpifadd: failed to find a good " 1877 "random IFID\n")); 1878 return (EINVAL); 1879 } 1880 ifra.ifra_addr.sin6_addr.s6_addr32[2] |= 1881 (randid[0] & ~(ifra.ifra_prefixmask.sin6_addr.s6_addr32[2])); 1882 ifra.ifra_addr.sin6_addr.s6_addr32[3] |= 1883 (randid[1] & ~(ifra.ifra_prefixmask.sin6_addr.s6_addr32[3])); 1884 1885 /* 1886 * in6_get_tmpifid() quite likely provided a unique interface ID. 1887 * However, we may still have a chance to see collision, because 1888 * there may be a time lag between generation of the ID and generation 1889 * of the address. So, we'll do one more sanity check. 1890 */ 1891 for (ia = in6_ifaddr; ia; ia = ia->ia_next) { 1892 if (IN6_ARE_ADDR_EQUAL(&ia->ia_addr.sin6_addr, 1893 &ifra.ifra_addr.sin6_addr)) { 1894 if (trylimit-- == 0) { 1895 /* 1896 * Give up. Something strange should have 1897 * happened. 1898 */ 1899 nd6log((LOG_NOTICE, "in6_tmpifadd: failed to " 1900 "find a unique random IFID\n")); 1901 return (EEXIST); 1902 } 1903 forcegen = 1; 1904 goto again; 1905 } 1906 } 1907 1908 /* 1909 * The Valid Lifetime is the lower of the Valid Lifetime of the 1910 * public address or TEMP_VALID_LIFETIME. 1911 * The Preferred Lifetime is the lower of the Preferred Lifetime 1912 * of the public address or TEMP_PREFERRED_LIFETIME - 1913 * DESYNC_FACTOR. 1914 */ 1915 if (ia0->ia6_lifetime.ia6t_vltime != ND6_INFINITE_LIFETIME) { 1916 vltime0 = IFA6_IS_INVALID(ia0) ? 0 : 1917 (ia0->ia6_lifetime.ia6t_vltime - 1918 (time_second - ia0->ia6_updatetime)); 1919 if (vltime0 > ip6_temp_valid_lifetime) 1920 vltime0 = ip6_temp_valid_lifetime; 1921 } else 1922 vltime0 = ip6_temp_valid_lifetime; 1923 if (ia0->ia6_lifetime.ia6t_pltime != ND6_INFINITE_LIFETIME) { 1924 pltime0 = IFA6_IS_DEPRECATED(ia0) ? 0 : 1925 (ia0->ia6_lifetime.ia6t_pltime - 1926 (time_second - ia0->ia6_updatetime)); 1927 if (pltime0 > ip6_temp_preferred_lifetime - ip6_desync_factor){ 1928 pltime0 = ip6_temp_preferred_lifetime - 1929 ip6_desync_factor; 1930 } 1931 } else 1932 pltime0 = ip6_temp_preferred_lifetime - ip6_desync_factor; 1933 ifra.ifra_lifetime.ia6t_vltime = vltime0; 1934 ifra.ifra_lifetime.ia6t_pltime = pltime0; 1935 1936 /* 1937 * A temporary address is created only if this calculated Preferred 1938 * Lifetime is greater than REGEN_ADVANCE time units. 1939 */ 1940 if (ifra.ifra_lifetime.ia6t_pltime <= ip6_temp_regen_advance) 1941 return (0); 1942 1943 /* XXX: scope zone ID? */ 1944 1945 ifra.ifra_flags |= (IN6_IFF_AUTOCONF|IN6_IFF_TEMPORARY); 1946 1947 /* allocate ifaddr structure, link into chain, etc. */ 1948 updateflags = 0; 1949 if (delay) 1950 updateflags |= IN6_IFAUPDATE_DADDELAY; 1951 if ((error = in6_update_ifa(ifp, &ifra, NULL, updateflags)) != 0) 1952 return (error); 1953 1954 newia = in6ifa_ifpwithaddr(ifp, &ifra.ifra_addr.sin6_addr); 1955 if (newia == NULL) { /* XXX: can it happen? */ 1956 nd6log((LOG_ERR, 1957 "in6_tmpifadd: ifa update succeeded, but we got " 1958 "no ifaddr\n")); 1959 return (EINVAL); /* XXX */ 1960 } 1961 newia->ia6_ndpr = ia0->ia6_ndpr; 1962 newia->ia6_ndpr->ndpr_refcnt++; 1963 1964 /* 1965 * A newly added address might affect the status of other addresses. 1966 * XXX: when the temporary address is generated with a new public 1967 * address, the onlink check is redundant. However, it would be safe 1968 * to do the check explicitly everywhere a new address is generated, 1969 * and, in fact, we surely need the check when we create a new 1970 * temporary address due to deprecation of an old temporary address. 1971 */ 1972 pfxlist_onlink_check(); 1973 1974 return (0); 1975 } 1976 1977 static int 1978 in6_init_prefix_ltimes(struct nd_prefix *ndpr) 1979 { 1980 if (ndpr->ndpr_pltime == ND6_INFINITE_LIFETIME) 1981 ndpr->ndpr_preferred = 0; 1982 else 1983 ndpr->ndpr_preferred = time_second + ndpr->ndpr_pltime; 1984 if (ndpr->ndpr_vltime == ND6_INFINITE_LIFETIME) 1985 ndpr->ndpr_expire = 0; 1986 else 1987 ndpr->ndpr_expire = time_second + ndpr->ndpr_vltime; 1988 1989 return 0; 1990 } 1991 1992 static void 1993 in6_init_address_ltimes(struct nd_prefix *new, struct in6_addrlifetime *lt6) 1994 { 1995 /* init ia6t_expire */ 1996 if (lt6->ia6t_vltime == ND6_INFINITE_LIFETIME) 1997 lt6->ia6t_expire = 0; 1998 else { 1999 lt6->ia6t_expire = time_second; 2000 lt6->ia6t_expire += lt6->ia6t_vltime; 2001 } 2002 2003 /* init ia6t_preferred */ 2004 if (lt6->ia6t_pltime == ND6_INFINITE_LIFETIME) 2005 lt6->ia6t_preferred = 0; 2006 else { 2007 lt6->ia6t_preferred = time_second; 2008 lt6->ia6t_preferred += lt6->ia6t_pltime; 2009 } 2010 } 2011 2012 /* 2013 * Delete all the routing table entries that use the specified gateway. 2014 * XXX: this function causes search through all entries of routing table, so 2015 * it shouldn't be called when acting as a router. 2016 */ 2017 void 2018 rt6_flush(struct in6_addr *gateway, struct ifnet *ifp) 2019 { 2020 struct radix_node_head *rnh = rt_tables[AF_INET6]; 2021 int s = splnet(); 2022 2023 /* We'll care only link-local addresses */ 2024 if (!IN6_IS_ADDR_LINKLOCAL(gateway)) { 2025 splx(s); 2026 return; 2027 } 2028 2029 RADIX_NODE_HEAD_LOCK(rnh); 2030 rnh->rnh_walktree(rnh, rt6_deleteroute, (void *)gateway); 2031 RADIX_NODE_HEAD_UNLOCK(rnh); 2032 splx(s); 2033 } 2034 2035 static int 2036 rt6_deleteroute(struct radix_node *rn, void *arg) 2037 { 2038 #define SIN6(s) ((struct sockaddr_in6 *)s) 2039 struct rtentry *rt = (struct rtentry *)rn; 2040 struct in6_addr *gate = (struct in6_addr *)arg; 2041 2042 if (rt->rt_gateway == NULL || rt->rt_gateway->sa_family != AF_INET6) 2043 return (0); 2044 2045 if (!IN6_ARE_ADDR_EQUAL(gate, &SIN6(rt->rt_gateway)->sin6_addr)) { 2046 return (0); 2047 } 2048 2049 /* 2050 * Do not delete a static route. 2051 * XXX: this seems to be a bit ad-hoc. Should we consider the 2052 * 'cloned' bit instead? 2053 */ 2054 if ((rt->rt_flags & RTF_STATIC) != 0) 2055 return (0); 2056 2057 /* 2058 * We delete only host route. This means, in particular, we don't 2059 * delete default route. 2060 */ 2061 if ((rt->rt_flags & RTF_HOST) == 0) 2062 return (0); 2063 2064 return (rtrequest(RTM_DELETE, rt_key(rt), rt->rt_gateway, 2065 rt_mask(rt), rt->rt_flags, 0)); 2066 #undef SIN6 2067 } 2068 2069 int 2070 nd6_setdefaultiface(int ifindex) 2071 { 2072 int error = 0; 2073 2074 if (ifindex < 0 || if_index < ifindex) 2075 return (EINVAL); 2076 if (ifindex != 0 && !ifnet_byindex(ifindex)) 2077 return (EINVAL); 2078 2079 if (nd6_defifindex != ifindex) { 2080 nd6_defifindex = ifindex; 2081 if (nd6_defifindex > 0) 2082 nd6_defifp = ifnet_byindex(nd6_defifindex); 2083 else 2084 nd6_defifp = NULL; 2085 2086 /* 2087 * Our current implementation assumes one-to-one maping between 2088 * interfaces and links, so it would be natural to use the 2089 * default interface as the default link. 2090 */ 2091 scope6_setdefault(nd6_defifp); 2092 } 2093 2094 return (error); 2095 }
Cache object: da040dc377d746787ac0c943189d3d27
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