1 /* $OpenBSD: nd6.c,v 1.192 2016/09/15 02:00:18 dlg Exp $ */ 2 /* $KAME: nd6.c,v 1.280 2002/06/08 19:52:07 itojun 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 <sys/param.h> 34 #include <sys/systm.h> 35 #include <sys/timeout.h> 36 #include <sys/malloc.h> 37 #include <sys/mbuf.h> 38 #include <sys/socket.h> 39 #include <sys/sockio.h> 40 #include <sys/time.h> 41 #include <sys/kernel.h> 42 #include <sys/pool.h> 43 #include <sys/protosw.h> 44 #include <sys/errno.h> 45 #include <sys/ioctl.h> 46 #include <sys/syslog.h> 47 #include <sys/queue.h> 48 #include <sys/task.h> 49 50 #include <net/if.h> 51 #include <net/if_dl.h> 52 #include <net/if_types.h> 53 #include <net/route.h> 54 55 #include <netinet/in.h> 56 #include <netinet/if_ether.h> 57 #include <netinet/ip_ipsp.h> 58 59 #include <netinet6/in6_var.h> 60 #include <netinet/ip6.h> 61 #include <netinet6/ip6_var.h> 62 #include <netinet6/nd6.h> 63 #include <netinet/icmp6.h> 64 65 #define ND6_SLOWTIMER_INTERVAL (60 * 60) /* 1 hour */ 66 #define ND6_RECALC_REACHTM_INTERVAL (60 * 120) /* 2 hours */ 67 68 /* timer values */ 69 int nd6_prune = 1; /* walk list every 1 seconds */ 70 int nd6_delay = 5; /* delay first probe time 5 second */ 71 int nd6_umaxtries = 3; /* maximum unicast query */ 72 int nd6_mmaxtries = 3; /* maximum multicast query */ 73 int nd6_gctimer = (60 * 60 * 24); /* 1 day: garbage collection timer */ 74 75 /* preventing too many loops in ND option parsing */ 76 int nd6_maxndopt = 10; /* max # of ND options allowed */ 77 78 int nd6_maxnudhint = 0; /* max # of subsequent upper layer hints */ 79 80 #ifdef ND6_DEBUG 81 int nd6_debug = 1; 82 #else 83 int nd6_debug = 0; 84 #endif 85 86 TAILQ_HEAD(llinfo_nd6_head, llinfo_nd6) nd6_list; 87 struct pool nd6_pool; /* pool for llinfo_nd6 structures */ 88 int nd6_inuse, nd6_allocated; 89 90 struct nd_drhead nd_defrouter; 91 struct nd_prhead nd_prefix = { 0 }; 92 93 int nd6_recalc_reachtm_interval = ND6_RECALC_REACHTM_INTERVAL; 94 95 void nd6_slowtimo(void *); 96 void nd6_invalidate(struct rtentry *); 97 struct llinfo_nd6 *nd6_free(struct rtentry *, int); 98 void nd6_llinfo_timer(void *); 99 100 struct timeout nd6_slowtimo_ch; 101 struct timeout nd6_timer_ch; 102 struct task nd6_timer_task; 103 void nd6_timer_work(void *); 104 105 int fill_drlist(void *, size_t *, size_t); 106 int fill_prlist(void *, size_t *, size_t); 107 108 void 109 nd6_init(void) 110 { 111 static int nd6_init_done = 0; 112 113 if (nd6_init_done) { 114 log(LOG_NOTICE, "%s called more than once\n", __func__); 115 return; 116 } 117 118 TAILQ_INIT(&nd6_list); 119 pool_init(&nd6_pool, sizeof(struct llinfo_nd6), 0, 120 IPL_SOFTNET, 0, "nd6", NULL); 121 122 /* initialization of the default router list */ 123 TAILQ_INIT(&nd_defrouter); 124 125 task_set(&nd6_timer_task, nd6_timer_work, NULL); 126 127 nd6_init_done = 1; 128 129 /* start timer */ 130 timeout_set(&nd6_slowtimo_ch, nd6_slowtimo, NULL); 131 timeout_add_sec(&nd6_slowtimo_ch, ND6_SLOWTIMER_INTERVAL); 132 133 nd6_rs_init(); 134 } 135 136 struct nd_ifinfo * 137 nd6_ifattach(struct ifnet *ifp) 138 { 139 struct nd_ifinfo *nd; 140 141 nd = malloc(sizeof(*nd), M_IP6NDP, M_WAITOK | M_ZERO); 142 143 nd->initialized = 1; 144 145 nd->basereachable = REACHABLE_TIME; 146 nd->reachable = ND_COMPUTE_RTIME(nd->basereachable); 147 nd->retrans = RETRANS_TIMER; 148 /* per-interface IFXF_AUTOCONF6 needs to be set too to accept RAs */ 149 nd->flags = (ND6_IFF_PERFORMNUD | ND6_IFF_ACCEPT_RTADV); 150 151 return nd; 152 } 153 154 void 155 nd6_ifdetach(struct nd_ifinfo *nd) 156 { 157 158 free(nd, M_IP6NDP, sizeof(*nd)); 159 } 160 161 void 162 nd6_option_init(void *opt, int icmp6len, union nd_opts *ndopts) 163 { 164 bzero(ndopts, sizeof(*ndopts)); 165 ndopts->nd_opts_search = (struct nd_opt_hdr *)opt; 166 ndopts->nd_opts_last 167 = (struct nd_opt_hdr *)(((u_char *)opt) + icmp6len); 168 169 if (icmp6len == 0) { 170 ndopts->nd_opts_done = 1; 171 ndopts->nd_opts_search = NULL; 172 } 173 } 174 175 /* 176 * Take one ND option. 177 */ 178 struct nd_opt_hdr * 179 nd6_option(union nd_opts *ndopts) 180 { 181 struct nd_opt_hdr *nd_opt; 182 int olen; 183 184 if (!ndopts) 185 panic("ndopts == NULL in nd6_option"); 186 if (!ndopts->nd_opts_last) 187 panic("uninitialized ndopts in nd6_option"); 188 if (!ndopts->nd_opts_search) 189 return NULL; 190 if (ndopts->nd_opts_done) 191 return NULL; 192 193 nd_opt = ndopts->nd_opts_search; 194 195 /* make sure nd_opt_len is inside the buffer */ 196 if ((caddr_t)&nd_opt->nd_opt_len >= (caddr_t)ndopts->nd_opts_last) { 197 bzero(ndopts, sizeof(*ndopts)); 198 return NULL; 199 } 200 201 olen = nd_opt->nd_opt_len << 3; 202 if (olen == 0) { 203 /* 204 * Message validation requires that all included 205 * options have a length that is greater than zero. 206 */ 207 bzero(ndopts, sizeof(*ndopts)); 208 return NULL; 209 } 210 211 ndopts->nd_opts_search = (struct nd_opt_hdr *)((caddr_t)nd_opt + olen); 212 if (ndopts->nd_opts_search > ndopts->nd_opts_last) { 213 /* option overruns the end of buffer, invalid */ 214 bzero(ndopts, sizeof(*ndopts)); 215 return NULL; 216 } else if (ndopts->nd_opts_search == ndopts->nd_opts_last) { 217 /* reached the end of options chain */ 218 ndopts->nd_opts_done = 1; 219 ndopts->nd_opts_search = NULL; 220 } 221 return nd_opt; 222 } 223 224 /* 225 * Parse multiple ND options. 226 * This function is much easier to use, for ND routines that do not need 227 * multiple options of the same type. 228 */ 229 int 230 nd6_options(union nd_opts *ndopts) 231 { 232 struct nd_opt_hdr *nd_opt; 233 int i = 0; 234 235 if (!ndopts) 236 panic("ndopts == NULL in nd6_options"); 237 if (!ndopts->nd_opts_last) 238 panic("uninitialized ndopts in nd6_options"); 239 if (!ndopts->nd_opts_search) 240 return 0; 241 242 while (1) { 243 nd_opt = nd6_option(ndopts); 244 if (!nd_opt && !ndopts->nd_opts_last) { 245 /* 246 * Message validation requires that all included 247 * options have a length that is greater than zero. 248 */ 249 icmp6stat.icp6s_nd_badopt++; 250 bzero(ndopts, sizeof(*ndopts)); 251 return -1; 252 } 253 254 if (!nd_opt) 255 goto skip1; 256 257 switch (nd_opt->nd_opt_type) { 258 case ND_OPT_SOURCE_LINKADDR: 259 case ND_OPT_TARGET_LINKADDR: 260 case ND_OPT_MTU: 261 case ND_OPT_REDIRECTED_HEADER: 262 if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) { 263 nd6log((LOG_INFO, 264 "duplicated ND6 option found (type=%d)\n", 265 nd_opt->nd_opt_type)); 266 /* XXX bark? */ 267 } else { 268 ndopts->nd_opt_array[nd_opt->nd_opt_type] 269 = nd_opt; 270 } 271 break; 272 case ND_OPT_PREFIX_INFORMATION: 273 if (ndopts->nd_opt_array[nd_opt->nd_opt_type] == 0) { 274 ndopts->nd_opt_array[nd_opt->nd_opt_type] 275 = nd_opt; 276 } 277 ndopts->nd_opts_pi_end = 278 (struct nd_opt_prefix_info *)nd_opt; 279 break; 280 default: 281 /* 282 * Unknown options must be silently ignored, 283 * to accommodate future extension to the protocol. 284 */ 285 nd6log((LOG_DEBUG, 286 "nd6_options: unsupported option %d - " 287 "option ignored\n", nd_opt->nd_opt_type)); 288 } 289 290 skip1: 291 i++; 292 if (i > nd6_maxndopt) { 293 icmp6stat.icp6s_nd_toomanyopt++; 294 nd6log((LOG_INFO, "too many loop in nd opt\n")); 295 break; 296 } 297 298 if (ndopts->nd_opts_done) 299 break; 300 } 301 302 return 0; 303 } 304 305 /* 306 * ND6 timer routine to handle ND6 entries 307 */ 308 void 309 nd6_llinfo_settimer(struct llinfo_nd6 *ln, int secs) 310 { 311 int s; 312 313 s = splsoftnet(); 314 315 if (secs < 0) { 316 ln->ln_rt->rt_expire = 0; 317 timeout_del(&ln->ln_timer_ch); 318 } else { 319 ln->ln_rt->rt_expire = time_uptime + secs; 320 timeout_add_sec(&ln->ln_timer_ch, secs); 321 } 322 323 splx(s); 324 } 325 326 void 327 nd6_llinfo_timer(void *arg) 328 { 329 int s; 330 struct llinfo_nd6 *ln; 331 struct rtentry *rt; 332 struct sockaddr_in6 *dst; 333 struct ifnet *ifp; 334 struct nd_ifinfo *ndi = NULL; 335 336 s = splsoftnet(); 337 338 ln = (struct llinfo_nd6 *)arg; 339 340 if ((rt = ln->ln_rt) == NULL) 341 panic("ln->ln_rt == NULL"); 342 if ((ifp = if_get(rt->rt_ifidx)) == NULL) { 343 splx(s); 344 return; 345 } 346 ndi = ND_IFINFO(ifp); 347 dst = satosin6(rt_key(rt)); 348 349 /* sanity check */ 350 if (rt->rt_llinfo != NULL && (struct llinfo_nd6 *)rt->rt_llinfo != ln) 351 panic("rt_llinfo(%p) is not equal to ln(%p)", 352 rt->rt_llinfo, ln); 353 if (!dst) 354 panic("dst=0 in nd6_timer(ln=%p)", ln); 355 356 switch (ln->ln_state) { 357 case ND6_LLINFO_INCOMPLETE: 358 if (ln->ln_asked < nd6_mmaxtries) { 359 ln->ln_asked++; 360 nd6_llinfo_settimer(ln, ndi->retrans / 1000); 361 nd6_ns_output(ifp, NULL, &dst->sin6_addr, ln, 0); 362 } else { 363 struct mbuf *m = ln->ln_hold; 364 if (m) { 365 ln->ln_hold = NULL; 366 /* 367 * Fake rcvif to make the ICMP error 368 * more helpful in diagnosing for the 369 * receiver. 370 * XXX: should we consider 371 * older rcvif? 372 */ 373 m->m_pkthdr.ph_ifidx = rt->rt_ifidx; 374 375 icmp6_error(m, ICMP6_DST_UNREACH, 376 ICMP6_DST_UNREACH_ADDR, 0); 377 if (ln->ln_hold == m) { 378 /* m is back in ln_hold. Discard. */ 379 m_freem(ln->ln_hold); 380 ln->ln_hold = NULL; 381 } 382 } 383 (void)nd6_free(rt, 0); 384 ln = NULL; 385 } 386 break; 387 case ND6_LLINFO_REACHABLE: 388 if (!ND6_LLINFO_PERMANENT(ln)) { 389 ln->ln_state = ND6_LLINFO_STALE; 390 nd6_llinfo_settimer(ln, nd6_gctimer); 391 } 392 break; 393 394 case ND6_LLINFO_STALE: 395 case ND6_LLINFO_PURGE: 396 /* Garbage Collection(RFC 2461 5.3) */ 397 if (!ND6_LLINFO_PERMANENT(ln)) { 398 (void)nd6_free(rt, 1); 399 ln = NULL; 400 } 401 break; 402 403 case ND6_LLINFO_DELAY: 404 if (ndi && (ndi->flags & ND6_IFF_PERFORMNUD) != 0) { 405 /* We need NUD */ 406 ln->ln_asked = 1; 407 ln->ln_state = ND6_LLINFO_PROBE; 408 nd6_llinfo_settimer(ln, ndi->retrans / 1000); 409 nd6_ns_output(ifp, &dst->sin6_addr, 410 &dst->sin6_addr, ln, 0); 411 } else { 412 ln->ln_state = ND6_LLINFO_STALE; /* XXX */ 413 nd6_llinfo_settimer(ln, nd6_gctimer); 414 } 415 break; 416 case ND6_LLINFO_PROBE: 417 if (ln->ln_asked < nd6_umaxtries) { 418 ln->ln_asked++; 419 nd6_llinfo_settimer(ln, ndi->retrans / 1000); 420 nd6_ns_output(ifp, &dst->sin6_addr, 421 &dst->sin6_addr, ln, 0); 422 } else { 423 (void)nd6_free(rt, 0); 424 ln = NULL; 425 } 426 break; 427 } 428 429 if_put(ifp); 430 splx(s); 431 } 432 433 /* 434 * ND6 timer routine to expire default route list and prefix list 435 */ 436 void 437 nd6_timer_work(void *null) 438 { 439 int s; 440 struct nd_defrouter *dr, *ndr; 441 struct nd_prefix *pr, *npr; 442 struct in6_ifaddr *ia6, *nia6; 443 444 s = splsoftnet(); 445 timeout_set(&nd6_timer_ch, nd6_timer, NULL); 446 timeout_add_sec(&nd6_timer_ch, nd6_prune); 447 448 /* expire default router list */ 449 TAILQ_FOREACH_SAFE(dr, &nd_defrouter, dr_entry, ndr) 450 if (dr->expire && dr->expire < time_second) 451 defrtrlist_del(dr); 452 453 /* 454 * expire interface addresses. 455 * in the past the loop was inside prefix expiry processing. 456 * However, from a stricter spec-conformance standpoint, we should 457 * rather separate address lifetimes and prefix lifetimes. 458 */ 459 TAILQ_FOREACH_SAFE(ia6, &in6_ifaddr, ia_list, nia6) { 460 /* check address lifetime */ 461 if (IFA6_IS_INVALID(ia6)) { 462 in6_purgeaddr(&ia6->ia_ifa); 463 } else if (IFA6_IS_DEPRECATED(ia6)) { 464 ia6->ia6_flags |= IN6_IFF_DEPRECATED; 465 } else { 466 /* 467 * A new RA might have made a deprecated address 468 * preferred. 469 */ 470 ia6->ia6_flags &= ~IN6_IFF_DEPRECATED; 471 } 472 } 473 474 /* expire prefix list */ 475 LIST_FOREACH_SAFE(pr, &nd_prefix, ndpr_entry, npr) { 476 /* 477 * check prefix lifetime. 478 * since pltime is just for autoconf, pltime processing for 479 * prefix is not necessary. 480 */ 481 if (pr->ndpr_vltime != ND6_INFINITE_LIFETIME && 482 time_second - pr->ndpr_lastupdate > pr->ndpr_vltime) { 483 /* 484 * address expiration and prefix expiration are 485 * separate. NEVER perform in6_purgeaddr here. 486 */ 487 488 prelist_remove(pr); 489 } 490 } 491 splx(s); 492 } 493 494 void 495 nd6_timer(void *ignored_arg) 496 { 497 task_add(systq, &nd6_timer_task); 498 } 499 500 /* 501 * Nuke neighbor cache/prefix/default router management table, right before 502 * ifp goes away. 503 */ 504 void 505 nd6_purge(struct ifnet *ifp) 506 { 507 struct llinfo_nd6 *ln, *nln; 508 struct nd_defrouter *dr, *ndr; 509 struct nd_prefix *pr, *npr; 510 511 /* 512 * Nuke default router list entries toward ifp. 513 * We defer removal of default router list entries that is installed 514 * in the routing table, in order to keep additional side effects as 515 * small as possible. 516 */ 517 TAILQ_FOREACH_SAFE(dr, &nd_defrouter, dr_entry, ndr) { 518 if (dr->installed) 519 continue; 520 521 if (dr->ifp == ifp) 522 defrtrlist_del(dr); 523 } 524 TAILQ_FOREACH_SAFE(dr, &nd_defrouter, dr_entry, ndr) { 525 if (!dr->installed) 526 continue; 527 528 if (dr->ifp == ifp) 529 defrtrlist_del(dr); 530 } 531 532 /* Nuke prefix list entries toward ifp */ 533 LIST_FOREACH_SAFE(pr, &nd_prefix, ndpr_entry, npr) { 534 if (pr->ndpr_ifp == ifp) 535 prelist_remove(pr); 536 } 537 538 if (ifp->if_xflags & IFXF_AUTOCONF6) { 539 /* refresh default router list */ 540 defrouter_select(); 541 } 542 543 /* 544 * Nuke neighbor cache entries for the ifp. 545 */ 546 TAILQ_FOREACH_SAFE(ln, &nd6_list, ln_list, nln) { 547 struct rtentry *rt; 548 struct sockaddr_dl *sdl; 549 550 rt = ln->ln_rt; 551 if (rt != NULL && rt->rt_gateway != NULL && 552 rt->rt_gateway->sa_family == AF_LINK) { 553 sdl = satosdl(rt->rt_gateway); 554 if (sdl->sdl_index == ifp->if_index) 555 nln = nd6_free(rt, 0); 556 } 557 } 558 } 559 560 struct rtentry * 561 nd6_lookup(struct in6_addr *addr6, int create, struct ifnet *ifp, 562 u_int rtableid) 563 { 564 struct rtentry *rt; 565 struct sockaddr_in6 sin6; 566 int flags; 567 568 bzero(&sin6, sizeof(sin6)); 569 sin6.sin6_len = sizeof(struct sockaddr_in6); 570 sin6.sin6_family = AF_INET6; 571 sin6.sin6_addr = *addr6; 572 flags = (create) ? RT_RESOLVE : 0; 573 574 rt = rtalloc(sin6tosa(&sin6), flags, rtableid); 575 if (rt != NULL && (rt->rt_flags & RTF_LLINFO) == 0) { 576 /* 577 * This is the case for the default route. 578 * If we want to create a neighbor cache for the address, we 579 * should free the route for the destination and allocate an 580 * interface route. 581 */ 582 if (create) { 583 rtfree(rt); 584 rt = NULL; 585 } 586 } 587 if (rt == NULL) { 588 if (create && ifp) { 589 struct rt_addrinfo info; 590 int error; 591 592 /* 593 * If no route is available and create is set, 594 * we allocate a host route for the destination 595 * and treat it like an interface route. 596 * This hack is necessary for a neighbor which can't 597 * be covered by our own prefix. 598 */ 599 struct ifaddr *ifa = 600 ifaof_ifpforaddr(sin6tosa(&sin6), ifp); 601 if (ifa == NULL) 602 return (NULL); 603 604 /* 605 * Create a new route. RTF_LLINFO is necessary 606 * to create a Neighbor Cache entry for the 607 * destination in nd6_rtrequest which will be 608 * called in rtrequest. 609 */ 610 bzero(&info, sizeof(info)); 611 info.rti_flags = RTF_HOST | RTF_LLINFO; 612 info.rti_info[RTAX_DST] = sin6tosa(&sin6); 613 info.rti_info[RTAX_GATEWAY] = sdltosa(ifp->if_sadl); 614 error = rtrequest(RTM_ADD, &info, RTP_CONNECTED, &rt, 615 rtableid); 616 if (error) 617 return (NULL); 618 if (rt->rt_llinfo != NULL) { 619 struct llinfo_nd6 *ln = 620 (struct llinfo_nd6 *)rt->rt_llinfo; 621 ln->ln_state = ND6_LLINFO_NOSTATE; 622 } 623 } else 624 return (NULL); 625 } 626 /* 627 * Validation for the entry. 628 * Note that the check for rt_llinfo is necessary because a cloned 629 * route from a parent route that has the L flag (e.g. the default 630 * route to a p2p interface) may have the flag, too, while the 631 * destination is not actually a neighbor. 632 */ 633 if ((rt->rt_flags & RTF_GATEWAY) || (rt->rt_flags & RTF_LLINFO) == 0 || 634 rt->rt_gateway->sa_family != AF_LINK || rt->rt_llinfo == NULL || 635 (ifp != NULL && rt->rt_ifidx != ifp->if_index)) { 636 if (create) { 637 char addr[INET6_ADDRSTRLEN]; 638 nd6log((LOG_DEBUG, "%s: failed to lookup %s (if=%s)\n", 639 __func__, 640 inet_ntop(AF_INET6, addr6, addr, sizeof(addr)), 641 ifp ? ifp->if_xname : "unspec")); 642 } 643 rtfree(rt); 644 return (NULL); 645 } 646 return (rt); 647 } 648 649 /* 650 * Detect if a given IPv6 address identifies a neighbor on a given link. 651 * XXX: should take care of the destination of a p2p link? 652 */ 653 int 654 nd6_is_addr_neighbor(struct sockaddr_in6 *addr, struct ifnet *ifp) 655 { 656 struct nd_prefix *pr; 657 struct in6_ifaddr *ia6; 658 struct ifaddr *ifa; 659 struct rtentry *rt; 660 661 /* 662 * A link-local address is always a neighbor. 663 * XXX: we should use the sin6_scope_id field rather than the embedded 664 * interface index. 665 * XXX: a link does not necessarily specify a single interface. 666 */ 667 if (IN6_IS_ADDR_LINKLOCAL(&addr->sin6_addr) && 668 ntohs(*(u_int16_t *)&addr->sin6_addr.s6_addr[2]) == ifp->if_index) 669 return (1); 670 671 TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) { 672 if (ifa->ifa_addr->sa_family != AF_INET6) 673 continue; 674 675 ia6 = ifatoia6(ifa); 676 677 /* Prefix check down below. */ 678 if (ia6->ia6_flags & IN6_IFF_AUTOCONF) 679 continue; 680 681 if (IN6_ARE_MASKED_ADDR_EQUAL(&addr->sin6_addr, 682 &ia6->ia_addr.sin6_addr, 683 &ia6->ia_prefixmask.sin6_addr)) 684 return (1); 685 } 686 687 /* 688 * If the address matches one of our on-link prefixes, it should be a 689 * neighbor. 690 */ 691 LIST_FOREACH(pr, &nd_prefix, ndpr_entry) { 692 if (pr->ndpr_ifp != ifp) 693 continue; 694 695 if (!(pr->ndpr_stateflags & NDPRF_ONLINK)) 696 continue; 697 698 if (IN6_ARE_MASKED_ADDR_EQUAL(&pr->ndpr_prefix.sin6_addr, 699 &addr->sin6_addr, &pr->ndpr_mask)) 700 return (1); 701 } 702 703 /* 704 * Even if the address matches none of our addresses, it might be 705 * in the neighbor cache. 706 */ 707 rt = nd6_lookup(&addr->sin6_addr, 0, ifp, ifp->if_rdomain); 708 if (rt != NULL) { 709 rtfree(rt); 710 return (1); 711 } 712 713 return (0); 714 } 715 716 void 717 nd6_invalidate(struct rtentry *rt) 718 { 719 struct llinfo_nd6 *ln = (struct llinfo_nd6 *)rt->rt_llinfo; 720 721 m_freem(ln->ln_hold); 722 ln->ln_hold = NULL; 723 ln->ln_state = ND6_LLINFO_INCOMPLETE; 724 ln->ln_asked = 0; 725 } 726 727 /* 728 * Free an nd6 llinfo entry. 729 * Since the function would cause significant changes in the kernel, DO NOT 730 * make it global, unless you have a strong reason for the change, and are sure 731 * that the change is safe. 732 */ 733 struct llinfo_nd6 * 734 nd6_free(struct rtentry *rt, int gc) 735 { 736 struct llinfo_nd6 *ln = (struct llinfo_nd6 *)rt->rt_llinfo, *next; 737 struct in6_addr in6 = satosin6(rt_key(rt))->sin6_addr; 738 struct nd_defrouter *dr; 739 struct ifnet *ifp; 740 int s; 741 742 /* 743 * we used to have pfctlinput(PRC_HOSTDEAD) here. 744 * even though it is not harmful, it was not really necessary. 745 */ 746 ifp = if_get(rt->rt_ifidx); 747 748 s = splsoftnet(); 749 if (!ip6_forwarding) { 750 dr = defrouter_lookup(&satosin6(rt_key(rt))->sin6_addr, 751 rt->rt_ifidx); 752 753 if (dr != NULL && dr->expire && 754 ln->ln_state == ND6_LLINFO_STALE && gc) { 755 /* 756 * If the reason for the deletion is just garbage 757 * collection, and the neighbor is an active default 758 * router, do not delete it. Instead, reset the GC 759 * timer using the router's lifetime. 760 * Simply deleting the entry would affect default 761 * router selection, which is not necessarily a good 762 * thing, especially when we're using router preference 763 * values. 764 * XXX: the check for ln_state would be redundant, 765 * but we intentionally keep it just in case. 766 */ 767 if (dr->expire > time_second) { 768 nd6_llinfo_settimer(ln, 769 dr->expire - time_second); 770 } else 771 nd6_llinfo_settimer(ln, nd6_gctimer); 772 splx(s); 773 if_put(ifp); 774 return (TAILQ_NEXT(ln, ln_list)); 775 } 776 777 if (ln->ln_router || dr) { 778 /* 779 * rt6_flush must be called whether or not the neighbor 780 * is in the Default Router List. 781 * See a corresponding comment in nd6_na_input(). 782 */ 783 rt6_flush(&in6, ifp); 784 } 785 786 if (dr) { 787 /* 788 * Unreachability of a router might affect the default 789 * router selection and on-link detection of advertised 790 * prefixes. 791 */ 792 793 /* 794 * Temporarily fake the state to choose a new default 795 * router and to perform on-link determination of 796 * prefixes correctly. 797 * Below the state will be set correctly, 798 * or the entry itself will be deleted. 799 */ 800 ln->ln_state = ND6_LLINFO_INCOMPLETE; 801 802 /* 803 * Since defrouter_select() does not affect the 804 * on-link determination and MIP6 needs the check 805 * before the default router selection, we perform 806 * the check now. 807 */ 808 pfxlist_onlink_check(); 809 810 /* 811 * refresh default router list 812 */ 813 defrouter_select(); 814 } 815 } 816 817 /* 818 * Before deleting the entry, remember the next entry as the 819 * return value. We need this because pfxlist_onlink_check() above 820 * might have freed other entries (particularly the old next entry) as 821 * a side effect (XXX). 822 */ 823 next = TAILQ_NEXT(ln, ln_list); 824 825 /* 826 * Detach the route from the routing tree and the list of neighbor 827 * caches, and disable the route entry not to be used in already 828 * cached routes. 829 */ 830 if (!ISSET(rt->rt_flags, RTF_STATIC|RTF_CACHED)) 831 rtdeletemsg(rt, ifp, ifp->if_rdomain); 832 splx(s); 833 834 if_put(ifp); 835 836 return (next); 837 } 838 839 /* 840 * Upper-layer reachability hint for Neighbor Unreachability Detection. 841 * 842 * XXX cost-effective methods? 843 */ 844 void 845 nd6_nud_hint(struct rtentry *rt) 846 { 847 struct llinfo_nd6 *ln; 848 struct ifnet *ifp; 849 850 ifp = if_get(rt->rt_ifidx); 851 if (ifp == NULL) 852 return; 853 854 if ((rt->rt_flags & RTF_GATEWAY) != 0 || 855 (rt->rt_flags & RTF_LLINFO) == 0 || 856 rt->rt_llinfo == NULL || rt->rt_gateway == NULL || 857 rt->rt_gateway->sa_family != AF_LINK) { 858 /* This is not a host route. */ 859 goto out; 860 } 861 862 ln = (struct llinfo_nd6 *)rt->rt_llinfo; 863 if (ln->ln_state < ND6_LLINFO_REACHABLE) 864 goto out; 865 866 /* 867 * if we get upper-layer reachability confirmation many times, 868 * it is possible we have false information. 869 */ 870 ln->ln_byhint++; 871 if (ln->ln_byhint > nd6_maxnudhint) 872 goto out; 873 874 ln->ln_state = ND6_LLINFO_REACHABLE; 875 if (!ND6_LLINFO_PERMANENT(ln)) 876 nd6_llinfo_settimer(ln, ND_IFINFO(ifp)->reachable); 877 out: 878 if_put(ifp); 879 } 880 881 void 882 nd6_rtrequest(struct ifnet *ifp, int req, struct rtentry *rt) 883 { 884 struct sockaddr *gate = rt->rt_gateway; 885 struct llinfo_nd6 *ln = (struct llinfo_nd6 *)rt->rt_llinfo; 886 struct ifaddr *ifa; 887 struct nd_defrouter *dr; 888 889 if (req == RTM_DELETE && (rt->rt_flags & RTF_GATEWAY) && 890 (IN6_ARE_ADDR_EQUAL(&(satosin6(rt_key(rt)))->sin6_addr, 891 &in6addr_any) && rt_plen(rt) == 0)) { 892 dr = defrouter_lookup(&satosin6(gate)->sin6_addr, 893 ifp->if_index); 894 if (dr) 895 dr->installed = 0; 896 } 897 898 if (ISSET(rt->rt_flags, RTF_GATEWAY|RTF_MULTICAST)) 899 return; 900 901 if (nd6_need_cache(ifp) == 0 && (rt->rt_flags & RTF_HOST) == 0) { 902 /* 903 * This is probably an interface direct route for a link 904 * which does not need neighbor caches (e.g. fe80::%lo0/64). 905 * We do not need special treatment below for such a route. 906 * Moreover, the RTF_LLINFO flag which would be set below 907 * would annoy the ndp(8) command. 908 */ 909 return; 910 } 911 912 if (req == RTM_RESOLVE && nd6_need_cache(ifp) == 0) { 913 /* 914 * For routing daemons like ospf6d we allow neighbor discovery 915 * based on the cloning route only. This allows us to sent 916 * packets directly into a network without having an address 917 * with matching prefix on the interface. If the cloning 918 * route is used for an stf interface, we would mistakenly 919 * make a neighbor cache for the host route, and would see 920 * strange neighbor solicitation for the corresponding 921 * destination. In order to avoid confusion, we check if the 922 * interface is suitable for neighbor discovery, and stop the 923 * process if not. Additionally, we remove the LLINFO flag 924 * so that ndp(8) will not try to get the neighbor information 925 * of the destination. 926 */ 927 rt->rt_flags &= ~RTF_LLINFO; 928 return; 929 } 930 931 switch (req) { 932 case RTM_ADD: 933 if ((rt->rt_flags & RTF_CLONING) || 934 ((rt->rt_flags & (RTF_LLINFO | RTF_LOCAL)) && ln == NULL)) { 935 if (ln != NULL) 936 nd6_llinfo_settimer(ln, 0); 937 if ((rt->rt_flags & RTF_CLONING) != 0) 938 break; 939 } 940 /* 941 * In IPv4 code, we try to announce new RTF_ANNOUNCE entry here. 942 * We don't do that here since llinfo is not ready yet. 943 * 944 * There are also couple of other things to be discussed: 945 * - unsolicited NA code needs improvement beforehand 946 * - RFC2461 says we MAY send multicast unsolicited NA 947 * (7.2.6 paragraph 4), however, it also says that we 948 * SHOULD provide a mechanism to prevent multicast NA storm. 949 * we don't have anything like it right now. 950 * note that the mechanism needs a mutual agreement 951 * between proxies, which means that we need to implement 952 * a new protocol, or a new kludge. 953 * - from RFC2461 6.2.4, host MUST NOT send an unsolicited NA. 954 * we need to check ip6forwarding before sending it. 955 * (or should we allow proxy ND configuration only for 956 * routers? there's no mention about proxy ND from hosts) 957 */ 958 #if 0 959 /* XXX it does not work */ 960 if (rt->rt_flags & RTF_ANNOUNCE) 961 nd6_na_output(ifp, 962 &satosin6(rt_key(rt))->sin6_addr, 963 &satosin6(rt_key(rt))->sin6_addr, 964 ip6_forwarding ? ND_NA_FLAG_ROUTER : 0, 965 1, NULL); 966 #endif 967 /* FALLTHROUGH */ 968 case RTM_RESOLVE: 969 if (gate->sa_family != AF_LINK || 970 gate->sa_len < sizeof(struct sockaddr_dl)) { 971 log(LOG_DEBUG, "%s: bad gateway value: %s\n", 972 __func__, ifp->if_xname); 973 break; 974 } 975 satosdl(gate)->sdl_type = ifp->if_type; 976 satosdl(gate)->sdl_index = ifp->if_index; 977 if (ln != NULL) 978 break; /* This happens on a route change */ 979 /* 980 * Case 2: This route may come from cloning, or a manual route 981 * add with a LL address. 982 */ 983 ln = pool_get(&nd6_pool, PR_NOWAIT | PR_ZERO); 984 rt->rt_llinfo = (caddr_t)ln; 985 if (ln == NULL) { 986 log(LOG_DEBUG, "%s: pool get failed\n", __func__); 987 break; 988 } 989 nd6_inuse++; 990 nd6_allocated++; 991 ln->ln_rt = rt; 992 timeout_set(&ln->ln_timer_ch, nd6_llinfo_timer, ln); 993 /* this is required for "ndp" command. - shin */ 994 if (req == RTM_ADD) { 995 /* 996 * gate should have some valid AF_LINK entry, 997 * and ln expire should have some lifetime 998 * which is specified by ndp command. 999 */ 1000 ln->ln_state = ND6_LLINFO_REACHABLE; 1001 ln->ln_byhint = 0; 1002 } else { 1003 /* 1004 * When req == RTM_RESOLVE, rt is created and 1005 * initialized in rtrequest(), so rt_expire is 0. 1006 */ 1007 ln->ln_state = ND6_LLINFO_NOSTATE; 1008 nd6_llinfo_settimer(ln, 0); 1009 } 1010 rt->rt_flags |= RTF_LLINFO; 1011 TAILQ_INSERT_HEAD(&nd6_list, ln, ln_list); 1012 1013 /* 1014 * If we have too many cache entries, initiate immediate 1015 * purging for some "less recently used" entries. Note that 1016 * we cannot directly call nd6_free() here because it would 1017 * cause re-entering rtable related routines triggering an LOR 1018 * problem for FreeBSD. 1019 */ 1020 if (ip6_neighborgcthresh >= 0 && 1021 nd6_inuse >= ip6_neighborgcthresh) { 1022 int i; 1023 1024 for (i = 0; i < 10; i++) { 1025 struct llinfo_nd6 *ln_end; 1026 1027 ln_end = TAILQ_LAST(&nd6_list, llinfo_nd6_head); 1028 if (ln_end == ln) 1029 break; 1030 1031 /* Move this entry to the head */ 1032 TAILQ_REMOVE(&nd6_list, ln_end, ln_list); 1033 TAILQ_INSERT_HEAD(&nd6_list, ln_end, ln_list); 1034 1035 if (ND6_LLINFO_PERMANENT(ln_end)) 1036 continue; 1037 1038 if (ln_end->ln_state > ND6_LLINFO_INCOMPLETE) 1039 ln_end->ln_state = ND6_LLINFO_STALE; 1040 else 1041 ln_end->ln_state = ND6_LLINFO_PURGE; 1042 nd6_llinfo_settimer(ln_end, 0); 1043 } 1044 } 1045 1046 /* 1047 * check if rt_key(rt) is one of my address assigned 1048 * to the interface. 1049 */ 1050 ifa = &in6ifa_ifpwithaddr(ifp, 1051 &satosin6(rt_key(rt))->sin6_addr)->ia_ifa; 1052 if (ifa) { 1053 nd6_llinfo_settimer(ln, -1); 1054 ln->ln_state = ND6_LLINFO_REACHABLE; 1055 ln->ln_byhint = 0; 1056 KASSERT(ifa == rt->rt_ifa); 1057 } else if (rt->rt_flags & RTF_ANNOUNCE) { 1058 nd6_llinfo_settimer(ln, -1); 1059 ln->ln_state = ND6_LLINFO_REACHABLE; 1060 ln->ln_byhint = 0; 1061 1062 /* join solicited node multicast for proxy ND */ 1063 if (ifp->if_flags & IFF_MULTICAST) { 1064 struct in6_addr llsol; 1065 int error; 1066 1067 llsol = satosin6(rt_key(rt))->sin6_addr; 1068 llsol.s6_addr16[0] = htons(0xff02); 1069 llsol.s6_addr16[1] = htons(ifp->if_index); 1070 llsol.s6_addr32[1] = 0; 1071 llsol.s6_addr32[2] = htonl(1); 1072 llsol.s6_addr8[12] = 0xff; 1073 1074 if (in6_addmulti(&llsol, ifp, &error)) { 1075 char addr[INET6_ADDRSTRLEN]; 1076 nd6log((LOG_ERR, "%s: failed to join " 1077 "%s (errno=%d)\n", ifp->if_xname, 1078 inet_ntop(AF_INET6, &llsol, 1079 addr, sizeof(addr)), 1080 error)); 1081 } 1082 } 1083 } 1084 break; 1085 1086 case RTM_DELETE: 1087 if (ln == NULL) 1088 break; 1089 /* leave from solicited node multicast for proxy ND */ 1090 if ((rt->rt_flags & RTF_ANNOUNCE) != 0 && 1091 (ifp->if_flags & IFF_MULTICAST) != 0) { 1092 struct in6_addr llsol; 1093 struct in6_multi *in6m; 1094 1095 llsol = satosin6(rt_key(rt))->sin6_addr; 1096 llsol.s6_addr16[0] = htons(0xff02); 1097 llsol.s6_addr16[1] = htons(ifp->if_index); 1098 llsol.s6_addr32[1] = 0; 1099 llsol.s6_addr32[2] = htonl(1); 1100 llsol.s6_addr8[12] = 0xff; 1101 1102 IN6_LOOKUP_MULTI(llsol, ifp, in6m); 1103 if (in6m) 1104 in6_delmulti(in6m); 1105 } 1106 nd6_inuse--; 1107 TAILQ_REMOVE(&nd6_list, ln, ln_list); 1108 nd6_llinfo_settimer(ln, -1); 1109 rt->rt_llinfo = NULL; 1110 rt->rt_flags &= ~RTF_LLINFO; 1111 m_freem(ln->ln_hold); 1112 pool_put(&nd6_pool, ln); 1113 break; 1114 1115 case RTM_INVALIDATE: 1116 nd6_invalidate(rt); 1117 break; 1118 } 1119 } 1120 1121 int 1122 nd6_ioctl(u_long cmd, caddr_t data, struct ifnet *ifp) 1123 { 1124 struct in6_ndireq *ndi = (struct in6_ndireq *)data; 1125 struct in6_nbrinfo *nbi = (struct in6_nbrinfo *)data; 1126 struct rtentry *rt; 1127 int error = 0; 1128 int s; 1129 1130 switch (cmd) { 1131 case SIOCGIFINFO_IN6: 1132 ndi->ndi = *ND_IFINFO(ifp); 1133 memset(&ndi->ndi.randomseed0, 0, sizeof ndi->ndi.randomseed0); 1134 memset(&ndi->ndi.randomseed1, 0, sizeof ndi->ndi.randomseed1); 1135 memset(&ndi->ndi.randomid, 0, sizeof ndi->ndi.randomid); 1136 break; 1137 case SIOCSIFINFO_FLAGS: 1138 ND_IFINFO(ifp)->flags = ndi->ndi.flags; 1139 break; 1140 case SIOCSNDFLUSH_IN6: /* XXX: the ioctl name is confusing... */ 1141 /* sync kernel routing table with the default router list */ 1142 defrouter_reset(); 1143 defrouter_select(); 1144 break; 1145 case SIOCSPFXFLUSH_IN6: 1146 { 1147 /* flush all the prefix advertised by routers */ 1148 struct nd_prefix *pr, *npr; 1149 1150 s = splsoftnet(); 1151 /* First purge the addresses referenced by a prefix. */ 1152 LIST_FOREACH_SAFE(pr, &nd_prefix, ndpr_entry, npr) { 1153 struct in6_ifaddr *ia6, *ia6_next; 1154 1155 if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr)) 1156 continue; /* XXX */ 1157 1158 /* do we really have to remove addresses as well? */ 1159 TAILQ_FOREACH_SAFE(ia6, &in6_ifaddr, ia_list, ia6_next) { 1160 if ((ia6->ia6_flags & IN6_IFF_AUTOCONF) == 0) 1161 continue; 1162 1163 if (ia6->ia6_ndpr == pr) 1164 in6_purgeaddr(&ia6->ia_ifa); 1165 } 1166 } 1167 /* 1168 * Purging the addresses might remove the prefix as well. 1169 * So run the loop again to access only prefixes that have 1170 * not been freed already. 1171 */ 1172 LIST_FOREACH_SAFE(pr, &nd_prefix, ndpr_entry, npr) { 1173 if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr)) 1174 continue; /* XXX */ 1175 1176 prelist_remove(pr); 1177 } 1178 splx(s); 1179 break; 1180 } 1181 case SIOCSRTRFLUSH_IN6: 1182 { 1183 /* flush all the default routers */ 1184 struct nd_defrouter *dr, *ndr; 1185 1186 s = splsoftnet(); 1187 defrouter_reset(); 1188 TAILQ_FOREACH_SAFE(dr, &nd_defrouter, dr_entry, ndr) 1189 defrtrlist_del(dr); 1190 defrouter_select(); 1191 splx(s); 1192 break; 1193 } 1194 case SIOCGNBRINFO_IN6: 1195 { 1196 struct llinfo_nd6 *ln; 1197 struct in6_addr nb_addr = nbi->addr; /* make local for safety */ 1198 time_t expire; 1199 1200 /* 1201 * XXX: KAME specific hack for scoped addresses 1202 * XXXX: for other scopes than link-local? 1203 */ 1204 if (IN6_IS_ADDR_LINKLOCAL(&nbi->addr) || 1205 IN6_IS_ADDR_MC_LINKLOCAL(&nbi->addr)) { 1206 u_int16_t *idp = (u_int16_t *)&nb_addr.s6_addr[2]; 1207 1208 if (*idp == 0) 1209 *idp = htons(ifp->if_index); 1210 } 1211 1212 s = splsoftnet(); 1213 rt = nd6_lookup(&nb_addr, 0, ifp, ifp->if_rdomain); 1214 if (rt == NULL || 1215 (ln = (struct llinfo_nd6 *)rt->rt_llinfo) == NULL) { 1216 error = EINVAL; 1217 rtfree(rt); 1218 splx(s); 1219 break; 1220 } 1221 expire = ln->ln_rt->rt_expire; 1222 if (expire != 0) { 1223 expire -= time_uptime; 1224 expire += time_second; 1225 } 1226 1227 nbi->state = ln->ln_state; 1228 nbi->asked = ln->ln_asked; 1229 nbi->isrouter = ln->ln_router; 1230 nbi->expire = expire; 1231 rtfree(rt); 1232 splx(s); 1233 1234 break; 1235 } 1236 } 1237 return (error); 1238 } 1239 1240 /* 1241 * Create neighbor cache entry and cache link-layer address, 1242 * on reception of inbound ND6 packets. (RS/RA/NS/redirect) 1243 * 1244 * type - ICMP6 type 1245 * code - type dependent information 1246 */ 1247 void 1248 nd6_cache_lladdr(struct ifnet *ifp, struct in6_addr *from, char *lladdr, 1249 int lladdrlen, int type, int code) 1250 { 1251 struct rtentry *rt = NULL; 1252 struct llinfo_nd6 *ln = NULL; 1253 int is_newentry; 1254 struct sockaddr_dl *sdl = NULL; 1255 int do_update; 1256 int olladdr; 1257 int llchange; 1258 int newstate = 0; 1259 1260 if (!ifp) 1261 panic("ifp == NULL in nd6_cache_lladdr"); 1262 if (!from) 1263 panic("from == NULL in nd6_cache_lladdr"); 1264 1265 /* nothing must be updated for unspecified address */ 1266 if (IN6_IS_ADDR_UNSPECIFIED(from)) 1267 return; 1268 1269 /* 1270 * Validation about ifp->if_addrlen and lladdrlen must be done in 1271 * the caller. 1272 * 1273 * XXX If the link does not have link-layer address, what should 1274 * we do? (ifp->if_addrlen == 0) 1275 * Spec says nothing in sections for RA, RS and NA. There's small 1276 * description on it in NS section (RFC 2461 7.2.3). 1277 */ 1278 1279 rt = nd6_lookup(from, 0, ifp, ifp->if_rdomain); 1280 if (rt == NULL) { 1281 #if 0 1282 /* nothing must be done if there's no lladdr */ 1283 if (!lladdr || !lladdrlen) 1284 return NULL; 1285 #endif 1286 1287 rt = nd6_lookup(from, 1, ifp, ifp->if_rdomain); 1288 is_newentry = 1; 1289 } else { 1290 /* do nothing if static ndp is set */ 1291 if (rt->rt_flags & RTF_STATIC) { 1292 rtfree(rt); 1293 return; 1294 } 1295 is_newentry = 0; 1296 } 1297 1298 if (!rt) 1299 return; 1300 if ((rt->rt_flags & (RTF_GATEWAY | RTF_LLINFO)) != RTF_LLINFO) { 1301 fail: 1302 (void)nd6_free(rt, 0); 1303 rtfree(rt); 1304 return; 1305 } 1306 ln = (struct llinfo_nd6 *)rt->rt_llinfo; 1307 if (ln == NULL) 1308 goto fail; 1309 if (rt->rt_gateway == NULL) 1310 goto fail; 1311 if (rt->rt_gateway->sa_family != AF_LINK) 1312 goto fail; 1313 sdl = satosdl(rt->rt_gateway); 1314 1315 olladdr = (sdl->sdl_alen) ? 1 : 0; 1316 if (olladdr && lladdr) { 1317 if (bcmp(lladdr, LLADDR(sdl), ifp->if_addrlen)) 1318 llchange = 1; 1319 else 1320 llchange = 0; 1321 } else 1322 llchange = 0; 1323 1324 /* 1325 * newentry olladdr lladdr llchange (*=record) 1326 * 0 n n -- (1) 1327 * 0 y n -- (2) 1328 * 0 n y -- (3) * STALE 1329 * 0 y y n (4) * 1330 * 0 y y y (5) * STALE 1331 * 1 -- n -- (6) NOSTATE(= PASSIVE) 1332 * 1 -- y -- (7) * STALE 1333 */ 1334 1335 if (llchange) { 1336 char addr[INET6_ADDRSTRLEN]; 1337 log(LOG_INFO, "ndp info overwritten for %s by %s on %s\n", 1338 inet_ntop(AF_INET6, from, addr, sizeof(addr)), 1339 ether_sprintf(lladdr), ifp->if_xname); 1340 } 1341 if (lladdr) { /* (3-5) and (7) */ 1342 /* 1343 * Record source link-layer address 1344 * XXX is it dependent to ifp->if_type? 1345 */ 1346 sdl->sdl_alen = ifp->if_addrlen; 1347 bcopy(lladdr, LLADDR(sdl), ifp->if_addrlen); 1348 } 1349 1350 if (!is_newentry) { 1351 if ((!olladdr && lladdr) || /* (3) */ 1352 (olladdr && lladdr && llchange)) { /* (5) */ 1353 do_update = 1; 1354 newstate = ND6_LLINFO_STALE; 1355 } else /* (1-2,4) */ 1356 do_update = 0; 1357 } else { 1358 do_update = 1; 1359 if (!lladdr) /* (6) */ 1360 newstate = ND6_LLINFO_NOSTATE; 1361 else /* (7) */ 1362 newstate = ND6_LLINFO_STALE; 1363 } 1364 1365 if (do_update) { 1366 /* 1367 * Update the state of the neighbor cache. 1368 */ 1369 ln->ln_state = newstate; 1370 1371 if (ln->ln_state == ND6_LLINFO_STALE) { 1372 /* 1373 * Since nd6_resolve() in ifp->if_output() will cause 1374 * state transition to DELAY and reset the timer, 1375 * we must set the timer now, although it is actually 1376 * meaningless. 1377 */ 1378 nd6_llinfo_settimer(ln, nd6_gctimer); 1379 1380 if (ln->ln_hold) { 1381 struct mbuf *n = ln->ln_hold; 1382 ln->ln_hold = NULL; 1383 /* 1384 * we assume ifp is not a p2p here, so just 1385 * set the 2nd argument as the 1st one. 1386 */ 1387 ifp->if_output(ifp, n, rt_key(rt), rt); 1388 if (ln->ln_hold == n) { 1389 /* n is back in ln_hold. Discard. */ 1390 m_freem(ln->ln_hold); 1391 ln->ln_hold = NULL; 1392 } 1393 } 1394 } else if (ln->ln_state == ND6_LLINFO_INCOMPLETE) { 1395 /* probe right away */ 1396 nd6_llinfo_settimer((void *)ln, 0); 1397 } 1398 } 1399 1400 /* 1401 * ICMP6 type dependent behavior. 1402 * 1403 * NS: clear IsRouter if new entry 1404 * RS: clear IsRouter 1405 * RA: set IsRouter if there's lladdr 1406 * redir: clear IsRouter if new entry 1407 * 1408 * RA case, (1): 1409 * The spec says that we must set IsRouter in the following cases: 1410 * - If lladdr exist, set IsRouter. This means (1-5). 1411 * - If it is old entry (!newentry), set IsRouter. This means (7). 1412 * So, based on the spec, in (1-5) and (7) cases we must set IsRouter. 1413 * A question arises for (1) case. (1) case has no lladdr in the 1414 * neighbor cache, this is similar to (6). 1415 * This case is rare but we figured that we MUST NOT set IsRouter. 1416 * 1417 * newentry olladdr lladdr llchange NS RS RA redir 1418 * D R 1419 * 0 n n -- (1) c ? s 1420 * 0 y n -- (2) c s s 1421 * 0 n y -- (3) c s s 1422 * 0 y y n (4) c s s 1423 * 0 y y y (5) c s s 1424 * 1 -- n -- (6) c c c s 1425 * 1 -- y -- (7) c c s c s 1426 * 1427 * (c=clear s=set) 1428 */ 1429 switch (type & 0xff) { 1430 case ND_NEIGHBOR_SOLICIT: 1431 /* 1432 * New entry must have is_router flag cleared. 1433 */ 1434 if (is_newentry) /* (6-7) */ 1435 ln->ln_router = 0; 1436 break; 1437 case ND_REDIRECT: 1438 /* 1439 * If the icmp is a redirect to a better router, always set the 1440 * is_router flag. Otherwise, if the entry is newly created, 1441 * clear the flag. [RFC 2461, sec 8.3] 1442 */ 1443 if (code == ND_REDIRECT_ROUTER) 1444 ln->ln_router = 1; 1445 else if (is_newentry) /* (6-7) */ 1446 ln->ln_router = 0; 1447 break; 1448 case ND_ROUTER_SOLICIT: 1449 /* 1450 * is_router flag must always be cleared. 1451 */ 1452 ln->ln_router = 0; 1453 break; 1454 case ND_ROUTER_ADVERT: 1455 /* 1456 * Mark an entry with lladdr as a router. 1457 */ 1458 if ((!is_newentry && (olladdr || lladdr)) || /* (2-5) */ 1459 (is_newentry && lladdr)) { /* (7) */ 1460 ln->ln_router = 1; 1461 } 1462 break; 1463 } 1464 1465 /* 1466 * When the link-layer address of a router changes, select the 1467 * best router again. In particular, when the neighbor entry is newly 1468 * created, it might affect the selection policy. 1469 * Question: can we restrict the first condition to the "is_newentry" 1470 * case? 1471 * XXX: when we hear an RA from a new router with the link-layer 1472 * address option, defrouter_select() is called twice, since 1473 * defrtrlist_update called the function as well. However, I believe 1474 * we can compromise the overhead, since it only happens the first 1475 * time. 1476 */ 1477 if (do_update && ln->ln_router && (ifp->if_xflags & IFXF_AUTOCONF6)) 1478 defrouter_select(); 1479 1480 rtfree(rt); 1481 } 1482 1483 void 1484 nd6_slowtimo(void *ignored_arg) 1485 { 1486 int s = splsoftnet(); 1487 struct nd_ifinfo *nd6if; 1488 struct ifnet *ifp; 1489 1490 timeout_set(&nd6_slowtimo_ch, nd6_slowtimo, NULL); 1491 timeout_add_sec(&nd6_slowtimo_ch, ND6_SLOWTIMER_INTERVAL); 1492 TAILQ_FOREACH(ifp, &ifnet, if_list) { 1493 nd6if = ND_IFINFO(ifp); 1494 if (nd6if->basereachable && /* already initialized */ 1495 (nd6if->recalctm -= ND6_SLOWTIMER_INTERVAL) <= 0) { 1496 /* 1497 * Since reachable time rarely changes by router 1498 * advertisements, we SHOULD insure that a new random 1499 * value gets recomputed at least once every few hours. 1500 * (RFC 2461, 6.3.4) 1501 */ 1502 nd6if->recalctm = nd6_recalc_reachtm_interval; 1503 nd6if->reachable = ND_COMPUTE_RTIME(nd6if->basereachable); 1504 } 1505 } 1506 splx(s); 1507 } 1508 1509 int 1510 nd6_resolve(struct ifnet *ifp, struct rtentry *rt0, struct mbuf *m, 1511 struct sockaddr *dst, u_char *desten) 1512 { 1513 struct sockaddr_dl *sdl; 1514 struct rtentry *rt; 1515 struct llinfo_nd6 *ln = NULL; 1516 1517 if (m->m_flags & M_MCAST) { 1518 ETHER_MAP_IPV6_MULTICAST(&satosin6(dst)->sin6_addr, desten); 1519 return (0); 1520 } 1521 1522 rt = rt_getll(rt0); 1523 1524 if (ISSET(rt->rt_flags, RTF_REJECT) && 1525 (rt->rt_expire == 0 || time_uptime < rt->rt_expire)) { 1526 m_freem(m); 1527 return (rt == rt0 ? EHOSTDOWN : EHOSTUNREACH); 1528 } 1529 1530 /* 1531 * Address resolution or Neighbor Unreachability Detection 1532 * for the next hop. 1533 * At this point, the destination of the packet must be a unicast 1534 * or an anycast address(i.e. not a multicast). 1535 */ 1536 if (!ISSET(rt->rt_flags, RTF_LLINFO)) { 1537 char addr[INET6_ADDRSTRLEN]; 1538 log(LOG_DEBUG, "%s: %s: route contains no ND information\n", 1539 __func__, inet_ntop(AF_INET6, 1540 &satosin6(rt_key(rt))->sin6_addr, addr, sizeof(addr))); 1541 m_freem(m); 1542 return (EINVAL); 1543 } 1544 1545 if (rt->rt_gateway->sa_family != AF_LINK) { 1546 printf("%s: something odd happens\n", __func__); 1547 m_freem(m); 1548 return (EINVAL); 1549 } 1550 1551 ln = (struct llinfo_nd6 *)rt->rt_llinfo; 1552 KASSERT(ln != NULL); 1553 1554 /* 1555 * Move this entry to the head of the queue so that it is less likely 1556 * for this entry to be a target of forced garbage collection (see 1557 * nd6_rtrequest()). 1558 */ 1559 TAILQ_REMOVE(&nd6_list, ln, ln_list); 1560 TAILQ_INSERT_HEAD(&nd6_list, ln, ln_list); 1561 1562 /* 1563 * The first time we send a packet to a neighbor whose entry is 1564 * STALE, we have to change the state to DELAY and a sets a timer to 1565 * expire in DELAY_FIRST_PROBE_TIME seconds to ensure do 1566 * neighbor unreachability detection on expiration. 1567 * (RFC 2461 7.3.3) 1568 */ 1569 if (ln->ln_state == ND6_LLINFO_STALE) { 1570 ln->ln_asked = 0; 1571 ln->ln_state = ND6_LLINFO_DELAY; 1572 nd6_llinfo_settimer(ln, nd6_delay); 1573 } 1574 1575 /* 1576 * If the neighbor cache entry has a state other than INCOMPLETE 1577 * (i.e. its link-layer address is already resolved), just 1578 * send the packet. 1579 */ 1580 if (ln->ln_state > ND6_LLINFO_INCOMPLETE) { 1581 sdl = satosdl(rt->rt_gateway); 1582 if (sdl->sdl_alen != ETHER_ADDR_LEN) { 1583 char addr[INET6_ADDRSTRLEN]; 1584 log(LOG_DEBUG, "%s: %s: incorrect nd6 information\n", 1585 __func__, 1586 inet_ntop(AF_INET6, &satosin6(dst)->sin6_addr, 1587 addr, sizeof(addr))); 1588 m_freem(m); 1589 return (EINVAL); 1590 } 1591 1592 bcopy(LLADDR(sdl), desten, sdl->sdl_alen); 1593 return (0); 1594 } 1595 1596 /* 1597 * There is a neighbor cache entry, but no ethernet address 1598 * response yet. Replace the held mbuf (if any) with this 1599 * latest one. 1600 */ 1601 if (ln->ln_state == ND6_LLINFO_NOSTATE) 1602 ln->ln_state = ND6_LLINFO_INCOMPLETE; 1603 m_freem(ln->ln_hold); 1604 ln->ln_hold = m; 1605 1606 /* 1607 * If there has been no NS for the neighbor after entering the 1608 * INCOMPLETE state, send the first solicitation. 1609 */ 1610 if (!ND6_LLINFO_PERMANENT(ln) && ln->ln_asked == 0) { 1611 ln->ln_asked++; 1612 nd6_llinfo_settimer(ln, ND_IFINFO(ifp)->retrans / 1000); 1613 nd6_ns_output(ifp, NULL, &satosin6(dst)->sin6_addr, ln, 0); 1614 } 1615 return (EAGAIN); 1616 } 1617 1618 int 1619 nd6_need_cache(struct ifnet *ifp) 1620 { 1621 /* 1622 * RFC2893 says: 1623 * - unidirectional tunnels needs no ND 1624 */ 1625 switch (ifp->if_type) { 1626 case IFT_ETHER: 1627 case IFT_IEEE80211: 1628 case IFT_CARP: 1629 return (1); 1630 default: 1631 return (0); 1632 } 1633 } 1634 1635 /* 1636 * oldp - syscall arg, need copyout 1637 * newp - syscall arg, need copyin 1638 */ 1639 1640 int 1641 nd6_sysctl(int name, void *oldp, size_t *oldlenp, void *newp, size_t newlen) 1642 { 1643 void *p; 1644 size_t ol; 1645 int error; 1646 1647 error = 0; 1648 1649 if (newp) 1650 return EPERM; 1651 if (oldp && !oldlenp) 1652 return EINVAL; 1653 ol = oldlenp ? *oldlenp : 0; 1654 1655 if (oldp) { 1656 p = malloc(ol, M_TEMP, M_WAITOK | M_CANFAIL); 1657 if (!p) 1658 return ENOMEM; 1659 } else 1660 p = NULL; 1661 switch (name) { 1662 case ICMPV6CTL_ND6_DRLIST: 1663 error = fill_drlist(p, oldlenp, ol); 1664 if (!error && p && oldp) 1665 error = copyout(p, oldp, *oldlenp); 1666 break; 1667 1668 case ICMPV6CTL_ND6_PRLIST: 1669 error = fill_prlist(p, oldlenp, ol); 1670 if (!error && p && oldp) 1671 error = copyout(p, oldp, *oldlenp); 1672 break; 1673 1674 default: 1675 error = ENOPROTOOPT; 1676 break; 1677 } 1678 free(p, M_TEMP, ol); 1679 1680 return (error); 1681 } 1682 1683 int 1684 fill_drlist(void *oldp, size_t *oldlenp, size_t ol) 1685 { 1686 int error = 0, s; 1687 struct in6_defrouter *d = NULL, *de = NULL; 1688 struct nd_defrouter *dr; 1689 size_t l; 1690 1691 s = splsoftnet(); 1692 1693 if (oldp) { 1694 d = (struct in6_defrouter *)oldp; 1695 de = (struct in6_defrouter *)((caddr_t)oldp + *oldlenp); 1696 } 1697 l = 0; 1698 1699 TAILQ_FOREACH(dr, &nd_defrouter, dr_entry) { 1700 if (oldp && d + 1 <= de) { 1701 bzero(d, sizeof(*d)); 1702 d->rtaddr.sin6_family = AF_INET6; 1703 d->rtaddr.sin6_len = sizeof(struct sockaddr_in6); 1704 in6_recoverscope(&d->rtaddr, &dr->rtaddr); 1705 d->flags = dr->flags; 1706 d->rtlifetime = dr->rtlifetime; 1707 d->expire = dr->expire; 1708 d->if_index = dr->ifp->if_index; 1709 } 1710 1711 l += sizeof(*d); 1712 if (d) 1713 d++; 1714 } 1715 1716 if (oldp) { 1717 *oldlenp = l; /* (caddr_t)d - (caddr_t)oldp */ 1718 if (l > ol) 1719 error = ENOMEM; 1720 } else 1721 *oldlenp = l; 1722 1723 splx(s); 1724 1725 return (error); 1726 } 1727 1728 int 1729 fill_prlist(void *oldp, size_t *oldlenp, size_t ol) 1730 { 1731 int error = 0, s; 1732 struct nd_prefix *pr; 1733 char *p = NULL, *ps = NULL; 1734 char *pe = NULL; 1735 size_t l; 1736 1737 s = splsoftnet(); 1738 1739 if (oldp) { 1740 ps = p = (char *)oldp; 1741 pe = (char *)oldp + *oldlenp; 1742 } 1743 l = 0; 1744 1745 LIST_FOREACH(pr, &nd_prefix, ndpr_entry) { 1746 u_short advrtrs; 1747 struct sockaddr_in6 sin6; 1748 struct nd_pfxrouter *pfr; 1749 struct in6_prefix pfx; 1750 1751 if (oldp && p + sizeof(struct in6_prefix) <= pe) { 1752 memset(&pfx, 0, sizeof(pfx)); 1753 ps = p; 1754 1755 pfx.prefix = pr->ndpr_prefix; 1756 in6_recoverscope(&pfx.prefix, 1757 &pfx.prefix.sin6_addr); 1758 pfx.raflags = pr->ndpr_raf; 1759 pfx.prefixlen = pr->ndpr_plen; 1760 pfx.vltime = pr->ndpr_vltime; 1761 pfx.pltime = pr->ndpr_pltime; 1762 pfx.if_index = pr->ndpr_ifp->if_index; 1763 if (pr->ndpr_vltime == ND6_INFINITE_LIFETIME) 1764 pfx.expire = 0; 1765 else { 1766 time_t maxexpire; 1767 1768 /* XXX: we assume time_t is signed. */ 1769 maxexpire = (time_t)~(1ULL << 1770 ((sizeof(maxexpire) * 8) - 1)); 1771 if (pr->ndpr_vltime < 1772 maxexpire - pr->ndpr_lastupdate) { 1773 pfx.expire = pr->ndpr_lastupdate + 1774 pr->ndpr_vltime; 1775 } else 1776 pfx.expire = maxexpire; 1777 } 1778 pfx.refcnt = pr->ndpr_refcnt; 1779 pfx.flags = pr->ndpr_stateflags; 1780 pfx.origin = PR_ORIG_RA; 1781 1782 p += sizeof(pfx); l += sizeof(pfx); 1783 1784 advrtrs = 0; 1785 LIST_FOREACH(pfr, &pr->ndpr_advrtrs, pfr_entry) { 1786 if (p + sizeof(sin6) > pe) { 1787 advrtrs++; 1788 continue; 1789 } 1790 bzero(&sin6, sizeof(sin6)); 1791 sin6.sin6_family = AF_INET6; 1792 sin6.sin6_len = sizeof(struct sockaddr_in6); 1793 in6_recoverscope(&sin6, &pfr->router->rtaddr); 1794 advrtrs++; 1795 memcpy(p, &sin6, sizeof(sin6)); 1796 p += sizeof(sin6); 1797 l += sizeof(sin6); 1798 } 1799 pfx.advrtrs = advrtrs; 1800 memcpy(ps, &pfx, sizeof(pfx)); 1801 } 1802 else { 1803 l += sizeof(pfx); 1804 advrtrs = 0; 1805 LIST_FOREACH(pfr, &pr->ndpr_advrtrs, pfr_entry) { 1806 advrtrs++; 1807 l += sizeof(sin6); 1808 } 1809 } 1810 } 1811 1812 if (oldp) { 1813 *oldlenp = l; /* (caddr_t)d - (caddr_t)oldp */ 1814 if (l > ol) 1815 error = ENOMEM; 1816 } else 1817 *oldlenp = l; 1818 1819 splx(s); 1820 1821 return (error); 1822 } 1823