1 /* $OpenBSD: nd6.c,v 1.264 2023/01/06 14:35:34 kn 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/errno.h> 44 #include <sys/ioctl.h> 45 #include <sys/syslog.h> 46 #include <sys/queue.h> 47 #include <sys/stdint.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_timer_next = -1; /* at which uptime nd6_timer runs */ 70 time_t nd6_expire_next = -1; /* at which uptime nd6_expire runs */ 71 int nd6_delay = 5; /* delay first probe time 5 second */ 72 int nd6_umaxtries = 3; /* maximum unicast query */ 73 int nd6_mmaxtries = 3; /* maximum multicast query */ 74 int nd6_gctimer = (60 * 60 * 24); /* 1 day: garbage collection timer */ 75 76 /* preventing too many loops in ND option parsing */ 77 int nd6_maxndopt = 10; /* max # of ND options allowed */ 78 79 int nd6_maxnudhint = 0; /* max # of subsequent upper layer hints */ 80 81 #ifdef ND6_DEBUG 82 int nd6_debug = 1; 83 #else 84 int nd6_debug = 0; 85 #endif 86 87 TAILQ_HEAD(llinfo_nd6_head, llinfo_nd6) nd6_list; 88 struct pool nd6_pool; /* pool for llinfo_nd6 structures */ 89 int nd6_inuse; 90 91 void nd6_timer(void *); 92 void nd6_slowtimo(void *); 93 void nd6_expire(void *); 94 void nd6_expire_timer(void *); 95 void nd6_invalidate(struct rtentry *); 96 void nd6_free(struct rtentry *); 97 int nd6_llinfo_timer(struct rtentry *); 98 99 struct timeout nd6_timer_to; 100 struct timeout nd6_slowtimo_ch; 101 struct timeout nd6_expire_timeout; 102 struct task nd6_expire_task; 103 104 void 105 nd6_init(void) 106 { 107 TAILQ_INIT(&nd6_list); 108 pool_init(&nd6_pool, sizeof(struct llinfo_nd6), 0, 109 IPL_SOFTNET, 0, "nd6", NULL); 110 111 task_set(&nd6_expire_task, nd6_expire, NULL); 112 113 /* start timer */ 114 timeout_set_proc(&nd6_timer_to, nd6_timer, NULL); 115 timeout_set_proc(&nd6_slowtimo_ch, nd6_slowtimo, NULL); 116 timeout_add_sec(&nd6_slowtimo_ch, ND6_SLOWTIMER_INTERVAL); 117 timeout_set(&nd6_expire_timeout, nd6_expire_timer, NULL); 118 } 119 120 void 121 nd6_ifattach(struct ifnet *ifp) 122 { 123 struct nd_ifinfo *nd; 124 125 nd = malloc(sizeof(*nd), M_IP6NDP, M_WAITOK | M_ZERO); 126 127 nd->reachable = ND_COMPUTE_RTIME(REACHABLE_TIME); 128 129 ifp->if_nd = nd; 130 } 131 132 void 133 nd6_ifdetach(struct ifnet *ifp) 134 { 135 struct nd_ifinfo *nd = ifp->if_nd; 136 137 free(nd, M_IP6NDP, sizeof(*nd)); 138 } 139 140 /* 141 * Parse multiple ND options. 142 * This function is much easier to use, for ND routines that do not need 143 * multiple options of the same type. 144 */ 145 int 146 nd6_options(void *opt, int icmp6len, struct nd_opts *ndopts) 147 { 148 struct nd_opt_hdr *nd_opt = opt, *next_opt, *last_opt; 149 int i = 0; 150 151 bzero(ndopts, sizeof(*ndopts)); 152 153 if (icmp6len == 0) 154 return 0; 155 156 next_opt = nd_opt; 157 last_opt = (struct nd_opt_hdr *)((u_char *)nd_opt + icmp6len); 158 159 while (1) { 160 int olen; 161 162 if (next_opt == NULL) 163 goto skip1; 164 165 nd_opt = next_opt; 166 167 /* make sure nd_opt_len is inside the buffer */ 168 if ((caddr_t)&nd_opt->nd_opt_len >= (caddr_t)last_opt) 169 goto invalid; 170 171 /* every option must have a length greater than zero */ 172 olen = nd_opt->nd_opt_len << 3; 173 if (olen == 0) 174 goto invalid; 175 176 next_opt = (struct nd_opt_hdr *)((caddr_t)nd_opt + olen); 177 if (next_opt > last_opt) { 178 /* option overruns the end of buffer */ 179 goto invalid; 180 } else if (next_opt == last_opt) { 181 /* reached the end of options chain */ 182 next_opt = NULL; 183 } 184 185 switch (nd_opt->nd_opt_type) { 186 case ND_OPT_SOURCE_LINKADDR: 187 if (ndopts->nd_opts_src_lladdr != NULL) 188 nd6log((LOG_INFO, "duplicated ND6 option found " 189 "(type=%d)\n", nd_opt->nd_opt_type)); 190 else 191 ndopts->nd_opts_src_lladdr = nd_opt; 192 break; 193 case ND_OPT_TARGET_LINKADDR: 194 if (ndopts->nd_opts_tgt_lladdr != NULL) 195 nd6log((LOG_INFO, "duplicated ND6 option found " 196 "(type=%d)\n", nd_opt->nd_opt_type)); 197 else 198 ndopts->nd_opts_tgt_lladdr = nd_opt; 199 break; 200 case ND_OPT_MTU: 201 case ND_OPT_REDIRECTED_HEADER: 202 case ND_OPT_PREFIX_INFORMATION: 203 case ND_OPT_DNSSL: 204 case ND_OPT_RDNSS: 205 /* Don't warn, not used by kernel */ 206 break; 207 default: 208 /* 209 * Unknown options must be silently ignored, 210 * to accommodate future extension to the protocol. 211 */ 212 nd6log((LOG_DEBUG, 213 "nd6_options: unsupported option %d - " 214 "option ignored\n", nd_opt->nd_opt_type)); 215 break; 216 } 217 218 skip1: 219 i++; 220 if (i > nd6_maxndopt) { 221 icmp6stat_inc(icp6s_nd_toomanyopt); 222 nd6log((LOG_INFO, "too many loop in nd opt\n")); 223 break; 224 } 225 226 if (next_opt == NULL) 227 break; 228 } 229 230 return 0; 231 232 invalid: 233 bzero(ndopts, sizeof(*ndopts)); 234 icmp6stat_inc(icp6s_nd_badopt); 235 return -1; 236 } 237 238 /* 239 * ND6 timer routine to handle ND6 entries 240 */ 241 void 242 nd6_llinfo_settimer(const struct llinfo_nd6 *ln, unsigned int secs) 243 { 244 time_t expire = getuptime() + secs; 245 246 NET_ASSERT_LOCKED(); 247 KASSERT(!ISSET(ln->ln_rt->rt_flags, RTF_LOCAL)); 248 249 ln->ln_rt->rt_expire = expire; 250 if (!timeout_pending(&nd6_timer_to) || expire < nd6_timer_next) { 251 nd6_timer_next = expire; 252 timeout_add_sec(&nd6_timer_to, secs); 253 } 254 } 255 256 void 257 nd6_timer(void *unused) 258 { 259 struct llinfo_nd6 *ln, *nln; 260 time_t expire = getuptime() + nd6_gctimer; 261 int secs; 262 263 NET_LOCK(); 264 TAILQ_FOREACH_SAFE(ln, &nd6_list, ln_list, nln) { 265 struct rtentry *rt = ln->ln_rt; 266 267 if (rt->rt_expire && rt->rt_expire <= getuptime()) 268 if (nd6_llinfo_timer(rt)) 269 continue; 270 271 if (rt->rt_expire && rt->rt_expire < expire) 272 expire = rt->rt_expire; 273 } 274 275 secs = expire - getuptime(); 276 if (secs < 0) 277 secs = 0; 278 if (!TAILQ_EMPTY(&nd6_list)) { 279 nd6_timer_next = getuptime() + secs; 280 timeout_add_sec(&nd6_timer_to, secs); 281 } 282 283 NET_UNLOCK(); 284 } 285 286 /* 287 * ND timer state handling. 288 * 289 * Returns 1 if `rt' should no longer be used, 0 otherwise. 290 */ 291 int 292 nd6_llinfo_timer(struct rtentry *rt) 293 { 294 struct llinfo_nd6 *ln = (struct llinfo_nd6 *)rt->rt_llinfo; 295 struct sockaddr_in6 *dst = satosin6(rt_key(rt)); 296 struct ifnet *ifp; 297 298 NET_ASSERT_LOCKED(); 299 300 if ((ifp = if_get(rt->rt_ifidx)) == NULL) 301 return 1; 302 303 switch (ln->ln_state) { 304 case ND6_LLINFO_INCOMPLETE: 305 if (ln->ln_asked < nd6_mmaxtries) { 306 ln->ln_asked++; 307 nd6_llinfo_settimer(ln, RETRANS_TIMER / 1000); 308 nd6_ns_output(ifp, NULL, &dst->sin6_addr, ln, 0); 309 } else { 310 struct mbuf *m = ln->ln_hold; 311 if (m) { 312 ln->ln_hold = NULL; 313 /* 314 * Fake rcvif to make the ICMP error 315 * more helpful in diagnosing for the 316 * receiver. 317 * XXX: should we consider 318 * older rcvif? 319 */ 320 m->m_pkthdr.ph_ifidx = rt->rt_ifidx; 321 322 icmp6_error(m, ICMP6_DST_UNREACH, 323 ICMP6_DST_UNREACH_ADDR, 0); 324 if (ln->ln_hold == m) { 325 /* m is back in ln_hold. Discard. */ 326 m_freem(ln->ln_hold); 327 ln->ln_hold = NULL; 328 } 329 } 330 nd6_free(rt); 331 ln = NULL; 332 } 333 break; 334 case ND6_LLINFO_REACHABLE: 335 if (!ND6_LLINFO_PERMANENT(ln)) { 336 ln->ln_state = ND6_LLINFO_STALE; 337 nd6_llinfo_settimer(ln, nd6_gctimer); 338 } 339 break; 340 341 case ND6_LLINFO_STALE: 342 case ND6_LLINFO_PURGE: 343 /* Garbage Collection(RFC 2461 5.3) */ 344 if (!ND6_LLINFO_PERMANENT(ln)) { 345 nd6_free(rt); 346 ln = NULL; 347 } 348 break; 349 350 case ND6_LLINFO_DELAY: 351 /* We need NUD */ 352 ln->ln_asked = 1; 353 ln->ln_state = ND6_LLINFO_PROBE; 354 nd6_llinfo_settimer(ln, RETRANS_TIMER / 1000); 355 nd6_ns_output(ifp, &dst->sin6_addr, &dst->sin6_addr, ln, 0); 356 break; 357 case ND6_LLINFO_PROBE: 358 if (ln->ln_asked < nd6_umaxtries) { 359 ln->ln_asked++; 360 nd6_llinfo_settimer(ln, RETRANS_TIMER / 1000); 361 nd6_ns_output(ifp, &dst->sin6_addr, 362 &dst->sin6_addr, ln, 0); 363 } else { 364 nd6_free(rt); 365 ln = NULL; 366 } 367 break; 368 } 369 370 if_put(ifp); 371 372 return (ln == NULL); 373 } 374 375 void 376 nd6_expire_timer_update(struct in6_ifaddr *ia6) 377 { 378 time_t expire_time = INT64_MAX; 379 int secs; 380 381 if (ia6->ia6_lifetime.ia6t_vltime != ND6_INFINITE_LIFETIME) 382 expire_time = ia6->ia6_lifetime.ia6t_expire; 383 384 if (!(ia6->ia6_flags & IN6_IFF_DEPRECATED) && 385 ia6->ia6_lifetime.ia6t_pltime != ND6_INFINITE_LIFETIME && 386 expire_time > ia6->ia6_lifetime.ia6t_preferred) 387 expire_time = ia6->ia6_lifetime.ia6t_preferred; 388 389 if (expire_time == INT64_MAX) 390 return; 391 392 /* 393 * IFA6_IS_INVALID() and IFA6_IS_DEPRECATED() check for uptime 394 * greater than ia6t_expire or ia6t_preferred, not greater or equal. 395 * Schedule timeout one second later so that either IFA6_IS_INVALID() 396 * or IFA6_IS_DEPRECATED() is true. 397 */ 398 expire_time++; 399 400 if (!timeout_pending(&nd6_expire_timeout) || 401 nd6_expire_next > expire_time) { 402 secs = expire_time - getuptime(); 403 if (secs < 0) 404 secs = 0; 405 406 timeout_add_sec(&nd6_expire_timeout, secs); 407 nd6_expire_next = expire_time; 408 } 409 } 410 411 /* 412 * Expire interface addresses. 413 */ 414 void 415 nd6_expire(void *unused) 416 { 417 struct ifnet *ifp; 418 419 NET_LOCK(); 420 421 TAILQ_FOREACH(ifp, &ifnetlist, if_list) { 422 struct ifaddr *ifa, *nifa; 423 struct in6_ifaddr *ia6; 424 425 TAILQ_FOREACH_SAFE(ifa, &ifp->if_addrlist, ifa_list, nifa) { 426 if (ifa->ifa_addr->sa_family != AF_INET6) 427 continue; 428 ia6 = ifatoia6(ifa); 429 /* check address lifetime */ 430 if (IFA6_IS_INVALID(ia6)) { 431 in6_purgeaddr(&ia6->ia_ifa); 432 } else { 433 if (IFA6_IS_DEPRECATED(ia6)) 434 ia6->ia6_flags |= IN6_IFF_DEPRECATED; 435 nd6_expire_timer_update(ia6); 436 } 437 } 438 } 439 440 NET_UNLOCK(); 441 } 442 443 void 444 nd6_expire_timer(void *unused) 445 { 446 task_add(net_tq(0), &nd6_expire_task); 447 } 448 449 /* 450 * Nuke neighbor cache/prefix/default router management table, right before 451 * ifp goes away. 452 */ 453 void 454 nd6_purge(struct ifnet *ifp) 455 { 456 struct llinfo_nd6 *ln, *nln; 457 458 NET_ASSERT_LOCKED(); 459 460 /* 461 * Nuke neighbor cache entries for the ifp. 462 */ 463 TAILQ_FOREACH_SAFE(ln, &nd6_list, ln_list, nln) { 464 struct rtentry *rt; 465 struct sockaddr_dl *sdl; 466 467 rt = ln->ln_rt; 468 if (rt != NULL && rt->rt_gateway != NULL && 469 rt->rt_gateway->sa_family == AF_LINK) { 470 sdl = satosdl(rt->rt_gateway); 471 if (sdl->sdl_index == ifp->if_index) 472 nd6_free(rt); 473 } 474 } 475 } 476 477 struct rtentry * 478 nd6_lookup(const struct in6_addr *addr6, int create, struct ifnet *ifp, 479 u_int rtableid) 480 { 481 struct rtentry *rt; 482 struct sockaddr_in6 sin6; 483 int flags; 484 485 bzero(&sin6, sizeof(sin6)); 486 sin6.sin6_len = sizeof(struct sockaddr_in6); 487 sin6.sin6_family = AF_INET6; 488 sin6.sin6_addr = *addr6; 489 flags = (create) ? RT_RESOLVE : 0; 490 491 rt = rtalloc(sin6tosa(&sin6), flags, rtableid); 492 if (rt != NULL && (rt->rt_flags & RTF_LLINFO) == 0) { 493 /* 494 * This is the case for the default route. 495 * If we want to create a neighbor cache for the address, we 496 * should free the route for the destination and allocate an 497 * interface route. 498 */ 499 if (create) { 500 rtfree(rt); 501 rt = NULL; 502 } 503 } 504 if (rt == NULL) { 505 if (create && ifp) { 506 struct rt_addrinfo info; 507 struct ifaddr *ifa; 508 int error; 509 510 /* 511 * If no route is available and create is set, 512 * we allocate a host route for the destination 513 * and treat it like an interface route. 514 * This hack is necessary for a neighbor which can't 515 * be covered by our own prefix. 516 */ 517 ifa = ifaof_ifpforaddr(sin6tosa(&sin6), ifp); 518 if (ifa == NULL) 519 return (NULL); 520 521 /* 522 * Create a new route. RTF_LLINFO is necessary 523 * to create a Neighbor Cache entry for the 524 * destination in nd6_rtrequest which will be 525 * called in rtrequest. 526 */ 527 bzero(&info, sizeof(info)); 528 info.rti_ifa = ifa; 529 info.rti_flags = RTF_HOST | RTF_LLINFO; 530 info.rti_info[RTAX_DST] = sin6tosa(&sin6); 531 info.rti_info[RTAX_GATEWAY] = sdltosa(ifp->if_sadl); 532 error = rtrequest(RTM_ADD, &info, RTP_CONNECTED, &rt, 533 rtableid); 534 if (error) 535 return (NULL); 536 if (rt->rt_llinfo != NULL) { 537 struct llinfo_nd6 *ln = 538 (struct llinfo_nd6 *)rt->rt_llinfo; 539 ln->ln_state = ND6_LLINFO_NOSTATE; 540 } 541 } else 542 return (NULL); 543 } 544 /* 545 * Validation for the entry. 546 * Note that the check for rt_llinfo is necessary because a cloned 547 * route from a parent route that has the L flag (e.g. the default 548 * route to a p2p interface) may have the flag, too, while the 549 * destination is not actually a neighbor. 550 */ 551 if ((rt->rt_flags & RTF_GATEWAY) || (rt->rt_flags & RTF_LLINFO) == 0 || 552 rt->rt_gateway->sa_family != AF_LINK || rt->rt_llinfo == NULL || 553 (ifp != NULL && rt->rt_ifidx != ifp->if_index)) { 554 if (create) { 555 char addr[INET6_ADDRSTRLEN]; 556 nd6log((LOG_DEBUG, "%s: failed to lookup %s (if=%s)\n", 557 __func__, 558 inet_ntop(AF_INET6, addr6, addr, sizeof(addr)), 559 ifp ? ifp->if_xname : "unspec")); 560 } 561 rtfree(rt); 562 return (NULL); 563 } 564 return (rt); 565 } 566 567 /* 568 * Detect if a given IPv6 address identifies a neighbor on a given link. 569 * XXX: should take care of the destination of a p2p link? 570 */ 571 int 572 nd6_is_addr_neighbor(const struct sockaddr_in6 *addr, struct ifnet *ifp) 573 { 574 struct in6_ifaddr *ia6; 575 struct ifaddr *ifa; 576 struct rtentry *rt; 577 578 /* 579 * A link-local address is always a neighbor. 580 * XXX: we should use the sin6_scope_id field rather than the embedded 581 * interface index. 582 * XXX: a link does not necessarily specify a single interface. 583 */ 584 if (IN6_IS_ADDR_LINKLOCAL(&addr->sin6_addr) && 585 ntohs(*(u_int16_t *)&addr->sin6_addr.s6_addr[2]) == ifp->if_index) 586 return (1); 587 588 TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) { 589 if (ifa->ifa_addr->sa_family != AF_INET6) 590 continue; 591 592 ia6 = ifatoia6(ifa); 593 594 /* Prefix check down below. */ 595 if (ia6->ia6_flags & IN6_IFF_AUTOCONF) 596 continue; 597 598 if (IN6_ARE_MASKED_ADDR_EQUAL(&addr->sin6_addr, 599 &ia6->ia_addr.sin6_addr, 600 &ia6->ia_prefixmask.sin6_addr)) 601 return (1); 602 } 603 604 /* 605 * Even if the address matches none of our addresses, it might be 606 * in the neighbor cache. 607 */ 608 rt = nd6_lookup(&addr->sin6_addr, 0, ifp, ifp->if_rdomain); 609 if (rt != NULL) { 610 rtfree(rt); 611 return (1); 612 } 613 614 return (0); 615 } 616 617 void 618 nd6_invalidate(struct rtentry *rt) 619 { 620 struct llinfo_nd6 *ln = (struct llinfo_nd6 *)rt->rt_llinfo; 621 struct sockaddr_dl *sdl = satosdl(rt->rt_gateway); 622 623 m_freem(ln->ln_hold); 624 sdl->sdl_alen = 0; 625 ln->ln_hold = NULL; 626 ln->ln_state = ND6_LLINFO_INCOMPLETE; 627 ln->ln_asked = 0; 628 } 629 630 /* 631 * Free an nd6 llinfo entry. 632 */ 633 void 634 nd6_free(struct rtentry *rt) 635 { 636 struct llinfo_nd6 *ln = (struct llinfo_nd6 *)rt->rt_llinfo; 637 struct in6_addr in6 = satosin6(rt_key(rt))->sin6_addr; 638 struct ifnet *ifp; 639 640 NET_ASSERT_LOCKED(); 641 642 ifp = if_get(rt->rt_ifidx); 643 644 if (!ip6_forwarding) { 645 if (ln->ln_router) { 646 /* 647 * rt6_flush must be called whether or not the neighbor 648 * is in the Default Router List. 649 * See a corresponding comment in nd6_na_input(). 650 */ 651 rt6_flush(&in6, ifp); 652 } 653 } 654 655 KASSERT(!ISSET(rt->rt_flags, RTF_LOCAL)); 656 nd6_invalidate(rt); 657 658 /* 659 * Detach the route from the routing tree and the list of neighbor 660 * caches, and disable the route entry not to be used in already 661 * cached routes. 662 */ 663 if (!ISSET(rt->rt_flags, RTF_STATIC|RTF_CACHED)) 664 rtdeletemsg(rt, ifp, ifp->if_rdomain); 665 666 if_put(ifp); 667 } 668 669 /* 670 * Upper-layer reachability hint for Neighbor Unreachability Detection. 671 * 672 * XXX cost-effective methods? 673 */ 674 void 675 nd6_nud_hint(struct rtentry *rt) 676 { 677 struct llinfo_nd6 *ln; 678 struct ifnet *ifp; 679 680 ifp = if_get(rt->rt_ifidx); 681 if (ifp == NULL) 682 return; 683 684 if ((rt->rt_flags & RTF_GATEWAY) != 0 || 685 (rt->rt_flags & RTF_LLINFO) == 0 || 686 rt->rt_llinfo == NULL || rt->rt_gateway == NULL || 687 rt->rt_gateway->sa_family != AF_LINK) { 688 /* This is not a host route. */ 689 goto out; 690 } 691 692 ln = (struct llinfo_nd6 *)rt->rt_llinfo; 693 if (ln->ln_state < ND6_LLINFO_REACHABLE) 694 goto out; 695 696 /* 697 * if we get upper-layer reachability confirmation many times, 698 * it is possible we have false information. 699 */ 700 ln->ln_byhint++; 701 if (ln->ln_byhint > nd6_maxnudhint) 702 goto out; 703 704 ln->ln_state = ND6_LLINFO_REACHABLE; 705 if (!ND6_LLINFO_PERMANENT(ln)) 706 nd6_llinfo_settimer(ln, ifp->if_nd->reachable); 707 out: 708 if_put(ifp); 709 } 710 711 void 712 nd6_rtrequest(struct ifnet *ifp, int req, struct rtentry *rt) 713 { 714 struct sockaddr *gate = rt->rt_gateway; 715 struct llinfo_nd6 *ln = (struct llinfo_nd6 *)rt->rt_llinfo; 716 struct ifaddr *ifa; 717 struct in6_ifaddr *ifa6; 718 719 if (ISSET(rt->rt_flags, RTF_GATEWAY|RTF_MULTICAST|RTF_MPLS)) 720 return; 721 722 if (nd6_need_cache(ifp) == 0 && (rt->rt_flags & RTF_HOST) == 0) { 723 /* 724 * This is probably an interface direct route for a link 725 * which does not need neighbor caches (e.g. fe80::%lo0/64). 726 * We do not need special treatment below for such a route. 727 * Moreover, the RTF_LLINFO flag which would be set below 728 * would annoy the ndp(8) command. 729 */ 730 return; 731 } 732 733 if (req == RTM_RESOLVE && nd6_need_cache(ifp) == 0) { 734 /* 735 * For routing daemons like ospf6d we allow neighbor discovery 736 * based on the cloning route only. This allows us to send 737 * packets directly into a network without having an address 738 * with matching prefix on the interface. If the cloning 739 * route is used for an 6to4 interface, we would mistakenly 740 * make a neighbor cache for the host route, and would see 741 * strange neighbor solicitation for the corresponding 742 * destination. In order to avoid confusion, we check if the 743 * interface is suitable for neighbor discovery, and stop the 744 * process if not. Additionally, we remove the LLINFO flag 745 * so that ndp(8) will not try to get the neighbor information 746 * of the destination. 747 */ 748 rt->rt_flags &= ~RTF_LLINFO; 749 return; 750 } 751 752 switch (req) { 753 case RTM_ADD: 754 if ((rt->rt_flags & RTF_CLONING) || 755 ((rt->rt_flags & (RTF_LLINFO | RTF_LOCAL)) && ln == NULL)) { 756 if (ln != NULL) 757 nd6_llinfo_settimer(ln, 0); 758 if ((rt->rt_flags & RTF_CLONING) != 0) 759 break; 760 } 761 /* 762 * In IPv4 code, we try to announce new RTF_ANNOUNCE entry here. 763 * We don't do that here since llinfo is not ready yet. 764 * 765 * There are also couple of other things to be discussed: 766 * - unsolicited NA code needs improvement beforehand 767 * - RFC2461 says we MAY send multicast unsolicited NA 768 * (7.2.6 paragraph 4), however, it also says that we 769 * SHOULD provide a mechanism to prevent multicast NA storm. 770 * we don't have anything like it right now. 771 * note that the mechanism needs a mutual agreement 772 * between proxies, which means that we need to implement 773 * a new protocol, or a new kludge. 774 * - from RFC2461 6.2.4, host MUST NOT send an unsolicited NA. 775 * we need to check ip6forwarding before sending it. 776 * (or should we allow proxy ND configuration only for 777 * routers? there's no mention about proxy ND from hosts) 778 */ 779 #if 0 780 /* XXX it does not work */ 781 if (rt->rt_flags & RTF_ANNOUNCE) 782 nd6_na_output(ifp, 783 &satosin6(rt_key(rt))->sin6_addr, 784 &satosin6(rt_key(rt))->sin6_addr, 785 ip6_forwarding ? ND_NA_FLAG_ROUTER : 0, 786 1, NULL); 787 #endif 788 /* FALLTHROUGH */ 789 case RTM_RESOLVE: 790 if (gate->sa_family != AF_LINK || 791 gate->sa_len < sizeof(struct sockaddr_dl)) { 792 log(LOG_DEBUG, "%s: bad gateway value: %s\n", 793 __func__, ifp->if_xname); 794 break; 795 } 796 satosdl(gate)->sdl_type = ifp->if_type; 797 satosdl(gate)->sdl_index = ifp->if_index; 798 if (ln != NULL) 799 break; /* This happens on a route change */ 800 /* 801 * Case 2: This route may come from cloning, or a manual route 802 * add with a LL address. 803 */ 804 ln = pool_get(&nd6_pool, PR_NOWAIT | PR_ZERO); 805 rt->rt_llinfo = (caddr_t)ln; 806 if (ln == NULL) { 807 log(LOG_DEBUG, "%s: pool get failed\n", __func__); 808 break; 809 } 810 nd6_inuse++; 811 ln->ln_rt = rt; 812 /* this is required for "ndp" command. - shin */ 813 if (req == RTM_ADD) { 814 /* 815 * gate should have some valid AF_LINK entry, 816 * and ln expire should have some lifetime 817 * which is specified by ndp command. 818 */ 819 ln->ln_state = ND6_LLINFO_REACHABLE; 820 ln->ln_byhint = 0; 821 } else { 822 /* 823 * When req == RTM_RESOLVE, rt is created and 824 * initialized in rtrequest(), so rt_expire is 0. 825 */ 826 ln->ln_state = ND6_LLINFO_NOSTATE; 827 nd6_llinfo_settimer(ln, 0); 828 } 829 rt->rt_flags |= RTF_LLINFO; 830 TAILQ_INSERT_HEAD(&nd6_list, ln, ln_list); 831 832 /* 833 * If we have too many cache entries, initiate immediate 834 * purging for some "less recently used" entries. Note that 835 * we cannot directly call nd6_free() here because it would 836 * cause re-entering rtable related routines triggering 837 * lock-order-reversal problems. 838 */ 839 if (ip6_neighborgcthresh >= 0 && 840 nd6_inuse >= ip6_neighborgcthresh) { 841 int i; 842 843 for (i = 0; i < 10; i++) { 844 struct llinfo_nd6 *ln_end; 845 846 ln_end = TAILQ_LAST(&nd6_list, llinfo_nd6_head); 847 if (ln_end == ln) 848 break; 849 850 /* Move this entry to the head */ 851 TAILQ_REMOVE(&nd6_list, ln_end, ln_list); 852 TAILQ_INSERT_HEAD(&nd6_list, ln_end, ln_list); 853 854 if (ND6_LLINFO_PERMANENT(ln_end)) 855 continue; 856 857 if (ln_end->ln_state > ND6_LLINFO_INCOMPLETE) 858 ln_end->ln_state = ND6_LLINFO_STALE; 859 else 860 ln_end->ln_state = ND6_LLINFO_PURGE; 861 nd6_llinfo_settimer(ln_end, 0); 862 } 863 } 864 865 /* 866 * check if rt_key(rt) is one of my address assigned 867 * to the interface. 868 */ 869 ifa6 = in6ifa_ifpwithaddr(ifp, 870 &satosin6(rt_key(rt))->sin6_addr); 871 ifa = ifa6 ? &ifa6->ia_ifa : NULL; 872 if (ifa) { 873 ln->ln_state = ND6_LLINFO_REACHABLE; 874 ln->ln_byhint = 0; 875 rt->rt_expire = 0; 876 KASSERT(ifa == rt->rt_ifa); 877 } else if (rt->rt_flags & RTF_ANNOUNCE) { 878 ln->ln_state = ND6_LLINFO_REACHABLE; 879 ln->ln_byhint = 0; 880 rt->rt_expire = 0; 881 882 /* join solicited node multicast for proxy ND */ 883 if (ifp->if_flags & IFF_MULTICAST) { 884 struct in6_addr llsol; 885 int error; 886 887 llsol = satosin6(rt_key(rt))->sin6_addr; 888 llsol.s6_addr16[0] = htons(0xff02); 889 llsol.s6_addr16[1] = htons(ifp->if_index); 890 llsol.s6_addr32[1] = 0; 891 llsol.s6_addr32[2] = htonl(1); 892 llsol.s6_addr8[12] = 0xff; 893 894 if (in6_addmulti(&llsol, ifp, &error)) { 895 char addr[INET6_ADDRSTRLEN]; 896 nd6log((LOG_ERR, "%s: failed to join " 897 "%s (errno=%d)\n", ifp->if_xname, 898 inet_ntop(AF_INET6, &llsol, 899 addr, sizeof(addr)), 900 error)); 901 } 902 } 903 } 904 break; 905 906 case RTM_DELETE: 907 if (ln == NULL) 908 break; 909 /* leave from solicited node multicast for proxy ND */ 910 if ((rt->rt_flags & RTF_ANNOUNCE) != 0 && 911 (ifp->if_flags & IFF_MULTICAST) != 0) { 912 struct in6_addr llsol; 913 struct in6_multi *in6m; 914 915 llsol = satosin6(rt_key(rt))->sin6_addr; 916 llsol.s6_addr16[0] = htons(0xff02); 917 llsol.s6_addr16[1] = htons(ifp->if_index); 918 llsol.s6_addr32[1] = 0; 919 llsol.s6_addr32[2] = htonl(1); 920 llsol.s6_addr8[12] = 0xff; 921 922 IN6_LOOKUP_MULTI(llsol, ifp, in6m); 923 if (in6m) 924 in6_delmulti(in6m); 925 } 926 nd6_inuse--; 927 TAILQ_REMOVE(&nd6_list, ln, ln_list); 928 rt->rt_expire = 0; 929 rt->rt_llinfo = NULL; 930 rt->rt_flags &= ~RTF_LLINFO; 931 m_freem(ln->ln_hold); 932 pool_put(&nd6_pool, ln); 933 break; 934 935 case RTM_INVALIDATE: 936 if (ln == NULL) 937 break; 938 if (!ISSET(rt->rt_flags, RTF_LOCAL)) 939 nd6_invalidate(rt); 940 break; 941 } 942 } 943 944 int 945 nd6_ioctl(u_long cmd, caddr_t data, struct ifnet *ifp) 946 { 947 struct in6_ndireq *ndi = (struct in6_ndireq *)data; 948 struct in6_nbrinfo *nbi = (struct in6_nbrinfo *)data; 949 struct rtentry *rt; 950 951 switch (cmd) { 952 case SIOCGIFINFO_IN6: 953 NET_LOCK_SHARED(); 954 ndi->ndi = *ifp->if_nd; 955 NET_UNLOCK_SHARED(); 956 return (0); 957 case SIOCGNBRINFO_IN6: 958 { 959 struct llinfo_nd6 *ln; 960 struct in6_addr nb_addr = nbi->addr; /* make local for safety */ 961 time_t expire; 962 963 NET_LOCK_SHARED(); 964 /* 965 * XXX: KAME specific hack for scoped addresses 966 * XXXX: for other scopes than link-local? 967 */ 968 if (IN6_IS_ADDR_LINKLOCAL(&nb_addr) || 969 IN6_IS_ADDR_MC_LINKLOCAL(&nb_addr)) { 970 u_int16_t *idp = (u_int16_t *)&nb_addr.s6_addr[2]; 971 972 if (*idp == 0) 973 *idp = htons(ifp->if_index); 974 } 975 976 rt = nd6_lookup(&nb_addr, 0, ifp, ifp->if_rdomain); 977 if (rt == NULL || 978 (ln = (struct llinfo_nd6 *)rt->rt_llinfo) == NULL) { 979 rtfree(rt); 980 NET_UNLOCK_SHARED(); 981 return (EINVAL); 982 } 983 expire = ln->ln_rt->rt_expire; 984 if (expire != 0) { 985 expire -= getuptime(); 986 expire += gettime(); 987 } 988 989 nbi->state = ln->ln_state; 990 nbi->asked = ln->ln_asked; 991 nbi->isrouter = ln->ln_router; 992 nbi->expire = expire; 993 994 rtfree(rt); 995 NET_UNLOCK_SHARED(); 996 return (0); 997 } 998 } 999 return (0); 1000 } 1001 1002 /* 1003 * Create neighbor cache entry and cache link-layer address, 1004 * on reception of inbound ND6 packets. (RS/RA/NS/redirect) 1005 * 1006 * type - ICMP6 type 1007 * code - type dependent information 1008 */ 1009 void 1010 nd6_cache_lladdr(struct ifnet *ifp, const struct in6_addr *from, char *lladdr, 1011 int lladdrlen, int type, int code) 1012 { 1013 struct rtentry *rt = NULL; 1014 struct llinfo_nd6 *ln = NULL; 1015 int is_newentry; 1016 struct sockaddr_dl *sdl = NULL; 1017 int do_update; 1018 int olladdr; 1019 int llchange; 1020 int newstate = 0; 1021 1022 if (!ifp) 1023 panic("%s: ifp == NULL", __func__); 1024 if (!from) 1025 panic("%s: from == NULL", __func__); 1026 1027 /* nothing must be updated for unspecified address */ 1028 if (IN6_IS_ADDR_UNSPECIFIED(from)) 1029 return; 1030 1031 /* 1032 * Validation about ifp->if_addrlen and lladdrlen must be done in 1033 * the caller. 1034 * 1035 * XXX If the link does not have link-layer address, what should 1036 * we do? (ifp->if_addrlen == 0) 1037 * Spec says nothing in sections for RA, RS and NA. There's small 1038 * description on it in NS section (RFC 2461 7.2.3). 1039 */ 1040 1041 rt = nd6_lookup(from, 0, ifp, ifp->if_rdomain); 1042 if (rt == NULL) { 1043 rt = nd6_lookup(from, 1, ifp, ifp->if_rdomain); 1044 is_newentry = 1; 1045 } else { 1046 /* do not overwrite local or static entry */ 1047 if (ISSET(rt->rt_flags, RTF_STATIC|RTF_LOCAL)) { 1048 rtfree(rt); 1049 return; 1050 } 1051 is_newentry = 0; 1052 } 1053 1054 if (!rt) 1055 return; 1056 if ((rt->rt_flags & (RTF_GATEWAY | RTF_LLINFO)) != RTF_LLINFO) { 1057 fail: 1058 nd6_free(rt); 1059 rtfree(rt); 1060 return; 1061 } 1062 ln = (struct llinfo_nd6 *)rt->rt_llinfo; 1063 if (ln == NULL) 1064 goto fail; 1065 if (rt->rt_gateway == NULL) 1066 goto fail; 1067 if (rt->rt_gateway->sa_family != AF_LINK) 1068 goto fail; 1069 sdl = satosdl(rt->rt_gateway); 1070 1071 olladdr = (sdl->sdl_alen) ? 1 : 0; 1072 if (olladdr && lladdr) { 1073 if (bcmp(lladdr, LLADDR(sdl), ifp->if_addrlen)) 1074 llchange = 1; 1075 else 1076 llchange = 0; 1077 } else 1078 llchange = 0; 1079 1080 /* 1081 * newentry olladdr lladdr llchange (*=record) 1082 * 0 n n -- (1) 1083 * 0 y n -- (2) 1084 * 0 n y -- (3) * STALE 1085 * 0 y y n (4) * 1086 * 0 y y y (5) * STALE 1087 * 1 -- n -- (6) NOSTATE(= PASSIVE) 1088 * 1 -- y -- (7) * STALE 1089 */ 1090 1091 if (llchange) { 1092 char addr[INET6_ADDRSTRLEN]; 1093 log(LOG_INFO, "ndp info overwritten for %s by %s on %s\n", 1094 inet_ntop(AF_INET6, from, addr, sizeof(addr)), 1095 ether_sprintf(lladdr), ifp->if_xname); 1096 } 1097 if (lladdr) { /* (3-5) and (7) */ 1098 /* 1099 * Record source link-layer address 1100 * XXX is it dependent to ifp->if_type? 1101 */ 1102 sdl->sdl_alen = ifp->if_addrlen; 1103 bcopy(lladdr, LLADDR(sdl), ifp->if_addrlen); 1104 } 1105 1106 if (!is_newentry) { 1107 if ((!olladdr && lladdr) || /* (3) */ 1108 (olladdr && lladdr && llchange)) { /* (5) */ 1109 do_update = 1; 1110 newstate = ND6_LLINFO_STALE; 1111 } else /* (1-2,4) */ 1112 do_update = 0; 1113 } else { 1114 do_update = 1; 1115 if (!lladdr) /* (6) */ 1116 newstate = ND6_LLINFO_NOSTATE; 1117 else /* (7) */ 1118 newstate = ND6_LLINFO_STALE; 1119 } 1120 1121 if (do_update) { 1122 /* 1123 * Update the state of the neighbor cache. 1124 */ 1125 ln->ln_state = newstate; 1126 1127 if (ln->ln_state == ND6_LLINFO_STALE) { 1128 /* 1129 * Since nd6_resolve() in ifp->if_output() will cause 1130 * state transition to DELAY and reset the timer, 1131 * we must set the timer now, although it is actually 1132 * meaningless. 1133 */ 1134 nd6_llinfo_settimer(ln, nd6_gctimer); 1135 1136 if (ln->ln_hold) { 1137 struct mbuf *n = ln->ln_hold; 1138 ln->ln_hold = NULL; 1139 /* 1140 * we assume ifp is not a p2p here, so just 1141 * set the 2nd argument as the 1st one. 1142 */ 1143 ifp->if_output(ifp, n, rt_key(rt), rt); 1144 if (ln->ln_hold == n) { 1145 /* n is back in ln_hold. Discard. */ 1146 m_freem(ln->ln_hold); 1147 ln->ln_hold = NULL; 1148 } 1149 } 1150 } else if (ln->ln_state == ND6_LLINFO_INCOMPLETE) { 1151 /* probe right away */ 1152 nd6_llinfo_settimer(ln, 0); 1153 } 1154 } 1155 1156 /* 1157 * ICMP6 type dependent behavior. 1158 * 1159 * NS: clear IsRouter if new entry 1160 * RS: clear IsRouter 1161 * RA: set IsRouter if there's lladdr 1162 * redir: clear IsRouter if new entry 1163 * 1164 * RA case, (1): 1165 * The spec says that we must set IsRouter in the following cases: 1166 * - If lladdr exist, set IsRouter. This means (1-5). 1167 * - If it is old entry (!newentry), set IsRouter. This means (7). 1168 * So, based on the spec, in (1-5) and (7) cases we must set IsRouter. 1169 * A question arises for (1) case. (1) case has no lladdr in the 1170 * neighbor cache, this is similar to (6). 1171 * This case is rare but we figured that we MUST NOT set IsRouter. 1172 * 1173 * newentry olladdr lladdr llchange NS RS RA redir 1174 * D R 1175 * 0 n n -- (1) c ? s 1176 * 0 y n -- (2) c s s 1177 * 0 n y -- (3) c s s 1178 * 0 y y n (4) c s s 1179 * 0 y y y (5) c s s 1180 * 1 -- n -- (6) c c c s 1181 * 1 -- y -- (7) c c s c s 1182 * 1183 * (c=clear s=set) 1184 */ 1185 switch (type & 0xff) { 1186 case ND_NEIGHBOR_SOLICIT: 1187 /* 1188 * New entry must have is_router flag cleared. 1189 */ 1190 if (is_newentry) /* (6-7) */ 1191 ln->ln_router = 0; 1192 break; 1193 case ND_REDIRECT: 1194 /* 1195 * If the icmp is a redirect to a better router, always set the 1196 * is_router flag. Otherwise, if the entry is newly created, 1197 * clear the flag. [RFC 2461, sec 8.3] 1198 */ 1199 if (code == ND_REDIRECT_ROUTER) 1200 ln->ln_router = 1; 1201 else if (is_newentry) /* (6-7) */ 1202 ln->ln_router = 0; 1203 break; 1204 case ND_ROUTER_SOLICIT: 1205 /* 1206 * is_router flag must always be cleared. 1207 */ 1208 ln->ln_router = 0; 1209 break; 1210 case ND_ROUTER_ADVERT: 1211 /* 1212 * Mark an entry with lladdr as a router. 1213 */ 1214 if ((!is_newentry && (olladdr || lladdr)) || /* (2-5) */ 1215 (is_newentry && lladdr)) { /* (7) */ 1216 ln->ln_router = 1; 1217 } 1218 break; 1219 } 1220 1221 rtfree(rt); 1222 } 1223 1224 void 1225 nd6_slowtimo(void *ignored_arg) 1226 { 1227 struct nd_ifinfo *nd6if; 1228 struct ifnet *ifp; 1229 1230 NET_LOCK(); 1231 1232 timeout_add_sec(&nd6_slowtimo_ch, ND6_SLOWTIMER_INTERVAL); 1233 1234 TAILQ_FOREACH(ifp, &ifnetlist, if_list) { 1235 nd6if = ifp->if_nd; 1236 if ((nd6if->recalctm -= ND6_SLOWTIMER_INTERVAL) <= 0) { 1237 /* 1238 * Since reachable time rarely changes by router 1239 * advertisements, we SHOULD insure that a new random 1240 * value gets recomputed at least once every few hours. 1241 * (RFC 2461, 6.3.4) 1242 */ 1243 nd6if->recalctm = ND6_RECALC_REACHTM_INTERVAL; 1244 nd6if->reachable = ND_COMPUTE_RTIME(REACHABLE_TIME); 1245 } 1246 } 1247 NET_UNLOCK(); 1248 } 1249 1250 int 1251 nd6_resolve(struct ifnet *ifp, struct rtentry *rt0, struct mbuf *m, 1252 struct sockaddr *dst, u_char *desten) 1253 { 1254 struct sockaddr_dl *sdl; 1255 struct rtentry *rt; 1256 struct llinfo_nd6 *ln = NULL; 1257 1258 if (m->m_flags & M_MCAST) { 1259 ETHER_MAP_IPV6_MULTICAST(&satosin6(dst)->sin6_addr, desten); 1260 return (0); 1261 } 1262 1263 rt = rt_getll(rt0); 1264 1265 if (ISSET(rt->rt_flags, RTF_REJECT) && 1266 (rt->rt_expire == 0 || getuptime() < rt->rt_expire)) { 1267 m_freem(m); 1268 return (rt == rt0 ? EHOSTDOWN : EHOSTUNREACH); 1269 } 1270 1271 /* 1272 * Address resolution or Neighbor Unreachability Detection 1273 * for the next hop. 1274 * At this point, the destination of the packet must be a unicast 1275 * or an anycast address(i.e. not a multicast). 1276 */ 1277 if (!ISSET(rt->rt_flags, RTF_LLINFO)) { 1278 char addr[INET6_ADDRSTRLEN]; 1279 log(LOG_DEBUG, "%s: %s: route contains no ND information\n", 1280 __func__, inet_ntop(AF_INET6, 1281 &satosin6(rt_key(rt))->sin6_addr, addr, sizeof(addr))); 1282 m_freem(m); 1283 return (EINVAL); 1284 } 1285 1286 if (rt->rt_gateway->sa_family != AF_LINK) { 1287 printf("%s: something odd happens\n", __func__); 1288 m_freem(m); 1289 return (EINVAL); 1290 } 1291 1292 ln = (struct llinfo_nd6 *)rt->rt_llinfo; 1293 KASSERT(ln != NULL); 1294 1295 /* 1296 * Move this entry to the head of the queue so that it is less likely 1297 * for this entry to be a target of forced garbage collection (see 1298 * nd6_rtrequest()). 1299 */ 1300 TAILQ_REMOVE(&nd6_list, ln, ln_list); 1301 TAILQ_INSERT_HEAD(&nd6_list, ln, ln_list); 1302 1303 /* 1304 * The first time we send a packet to a neighbor whose entry is 1305 * STALE, we have to change the state to DELAY and set a timer to 1306 * expire in DELAY_FIRST_PROBE_TIME seconds to ensure we do 1307 * neighbor unreachability detection on expiration. 1308 * (RFC 2461 7.3.3) 1309 */ 1310 if (ln->ln_state == ND6_LLINFO_STALE) { 1311 ln->ln_asked = 0; 1312 ln->ln_state = ND6_LLINFO_DELAY; 1313 nd6_llinfo_settimer(ln, nd6_delay); 1314 } 1315 1316 /* 1317 * If the neighbor cache entry has a state other than INCOMPLETE 1318 * (i.e. its link-layer address is already resolved), just 1319 * send the packet. 1320 */ 1321 if (ln->ln_state > ND6_LLINFO_INCOMPLETE) { 1322 sdl = satosdl(rt->rt_gateway); 1323 if (sdl->sdl_alen != ETHER_ADDR_LEN) { 1324 char addr[INET6_ADDRSTRLEN]; 1325 log(LOG_DEBUG, "%s: %s: incorrect nd6 information\n", 1326 __func__, 1327 inet_ntop(AF_INET6, &satosin6(dst)->sin6_addr, 1328 addr, sizeof(addr))); 1329 m_freem(m); 1330 return (EINVAL); 1331 } 1332 1333 bcopy(LLADDR(sdl), desten, sdl->sdl_alen); 1334 return (0); 1335 } 1336 1337 /* 1338 * There is a neighbor cache entry, but no ethernet address 1339 * response yet. Replace the held mbuf (if any) with this 1340 * latest one. 1341 */ 1342 if (ln->ln_state == ND6_LLINFO_NOSTATE) 1343 ln->ln_state = ND6_LLINFO_INCOMPLETE; 1344 m_freem(ln->ln_hold); 1345 ln->ln_hold = m; 1346 1347 /* 1348 * If there has been no NS for the neighbor after entering the 1349 * INCOMPLETE state, send the first solicitation. 1350 */ 1351 if (!ND6_LLINFO_PERMANENT(ln) && ln->ln_asked == 0) { 1352 ln->ln_asked++; 1353 nd6_llinfo_settimer(ln, RETRANS_TIMER / 1000); 1354 nd6_ns_output(ifp, NULL, &satosin6(dst)->sin6_addr, ln, 0); 1355 } 1356 return (EAGAIN); 1357 } 1358 1359 int 1360 nd6_need_cache(struct ifnet *ifp) 1361 { 1362 /* 1363 * RFC2893 says: 1364 * - unidirectional tunnels needs no ND 1365 */ 1366 switch (ifp->if_type) { 1367 case IFT_ETHER: 1368 case IFT_IEEE80211: 1369 case IFT_CARP: 1370 return (1); 1371 default: 1372 return (0); 1373 } 1374 } 1375