1 /* $OpenBSD: nd6.c,v 1.235 2021/03/08 16:49:07 florian 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/stdint.h> 49 #include <sys/task.h> 50 51 #include <net/if.h> 52 #include <net/if_dl.h> 53 #include <net/if_types.h> 54 #include <net/route.h> 55 56 #include <netinet/in.h> 57 #include <netinet/if_ether.h> 58 #include <netinet/ip_ipsp.h> 59 60 #include <netinet6/in6_var.h> 61 #include <netinet/ip6.h> 62 #include <netinet6/ip6_var.h> 63 #include <netinet6/nd6.h> 64 #include <netinet/icmp6.h> 65 66 #define ND6_SLOWTIMER_INTERVAL (60 * 60) /* 1 hour */ 67 #define ND6_RECALC_REACHTM_INTERVAL (60 * 120) /* 2 hours */ 68 69 /* timer values */ 70 int nd6_timer_next = -1; /* at which uptime nd6_timer runs */ 71 time_t nd6_expire_next = -1; /* at which uptime nd6_expire runs */ 72 int nd6_delay = 5; /* delay first probe time 5 second */ 73 int nd6_umaxtries = 3; /* maximum unicast query */ 74 int nd6_mmaxtries = 3; /* maximum multicast query */ 75 int nd6_gctimer = (60 * 60 * 24); /* 1 day: garbage collection timer */ 76 77 /* preventing too many loops in ND option parsing */ 78 int nd6_maxndopt = 10; /* max # of ND options allowed */ 79 80 int nd6_maxnudhint = 0; /* max # of subsequent upper layer hints */ 81 82 #ifdef ND6_DEBUG 83 int nd6_debug = 1; 84 #else 85 int nd6_debug = 0; 86 #endif 87 88 TAILQ_HEAD(llinfo_nd6_head, llinfo_nd6) nd6_list; 89 struct pool nd6_pool; /* pool for llinfo_nd6 structures */ 90 int nd6_inuse, nd6_allocated; 91 92 int nd6_recalc_reachtm_interval = ND6_RECALC_REACHTM_INTERVAL; 93 94 void nd6_timer(void *); 95 void nd6_slowtimo(void *); 96 void nd6_expire(void *); 97 void nd6_expire_timer(void *); 98 void nd6_invalidate(struct rtentry *); 99 void nd6_free(struct rtentry *); 100 int nd6_llinfo_timer(struct rtentry *); 101 102 struct timeout nd6_timer_to; 103 struct timeout nd6_slowtimo_ch; 104 struct timeout nd6_expire_timeout; 105 struct task nd6_expire_task; 106 107 void 108 nd6_init(void) 109 { 110 static int nd6_init_done = 0; 111 112 if (nd6_init_done) { 113 log(LOG_NOTICE, "%s called more than once\n", __func__); 114 return; 115 } 116 117 TAILQ_INIT(&nd6_list); 118 pool_init(&nd6_pool, sizeof(struct llinfo_nd6), 0, 119 IPL_SOFTNET, 0, "nd6", NULL); 120 121 task_set(&nd6_expire_task, nd6_expire, NULL); 122 123 nd6_init_done = 1; 124 125 /* start timer */ 126 timeout_set_proc(&nd6_timer_to, nd6_timer, &nd6_timer_to); 127 timeout_set_proc(&nd6_slowtimo_ch, nd6_slowtimo, NULL); 128 timeout_add_sec(&nd6_slowtimo_ch, ND6_SLOWTIMER_INTERVAL); 129 timeout_set(&nd6_expire_timeout, nd6_expire_timer, NULL); 130 } 131 132 struct nd_ifinfo * 133 nd6_ifattach(struct ifnet *ifp) 134 { 135 struct nd_ifinfo *nd; 136 137 nd = malloc(sizeof(*nd), M_IP6NDP, M_WAITOK | M_ZERO); 138 139 nd->initialized = 1; 140 141 nd->basereachable = REACHABLE_TIME; 142 nd->reachable = ND_COMPUTE_RTIME(nd->basereachable); 143 nd->retrans = RETRANS_TIMER; 144 145 return nd; 146 } 147 148 void 149 nd6_ifdetach(struct nd_ifinfo *nd) 150 { 151 152 free(nd, M_IP6NDP, sizeof(*nd)); 153 } 154 155 void 156 nd6_option_init(void *opt, int icmp6len, union nd_opts *ndopts) 157 { 158 bzero(ndopts, sizeof(*ndopts)); 159 ndopts->nd_opts_search = (struct nd_opt_hdr *)opt; 160 ndopts->nd_opts_last 161 = (struct nd_opt_hdr *)(((u_char *)opt) + icmp6len); 162 163 if (icmp6len == 0) { 164 ndopts->nd_opts_done = 1; 165 ndopts->nd_opts_search = NULL; 166 } 167 } 168 169 /* 170 * Take one ND option. 171 */ 172 struct nd_opt_hdr * 173 nd6_option(union nd_opts *ndopts) 174 { 175 struct nd_opt_hdr *nd_opt; 176 int olen; 177 178 if (!ndopts) 179 panic("%s: ndopts == NULL", __func__); 180 if (!ndopts->nd_opts_last) 181 panic("%s: uninitialized ndopts", __func__); 182 if (!ndopts->nd_opts_search) 183 return NULL; 184 if (ndopts->nd_opts_done) 185 return NULL; 186 187 nd_opt = ndopts->nd_opts_search; 188 189 /* make sure nd_opt_len is inside the buffer */ 190 if ((caddr_t)&nd_opt->nd_opt_len >= (caddr_t)ndopts->nd_opts_last) { 191 bzero(ndopts, sizeof(*ndopts)); 192 return NULL; 193 } 194 195 olen = nd_opt->nd_opt_len << 3; 196 if (olen == 0) { 197 /* 198 * Message validation requires that all included 199 * options have a length that is greater than zero. 200 */ 201 bzero(ndopts, sizeof(*ndopts)); 202 return NULL; 203 } 204 205 ndopts->nd_opts_search = (struct nd_opt_hdr *)((caddr_t)nd_opt + olen); 206 if (ndopts->nd_opts_search > ndopts->nd_opts_last) { 207 /* option overruns the end of buffer, invalid */ 208 bzero(ndopts, sizeof(*ndopts)); 209 return NULL; 210 } else if (ndopts->nd_opts_search == ndopts->nd_opts_last) { 211 /* reached the end of options chain */ 212 ndopts->nd_opts_done = 1; 213 ndopts->nd_opts_search = NULL; 214 } 215 return nd_opt; 216 } 217 218 /* 219 * Parse multiple ND options. 220 * This function is much easier to use, for ND routines that do not need 221 * multiple options of the same type. 222 */ 223 int 224 nd6_options(union nd_opts *ndopts) 225 { 226 struct nd_opt_hdr *nd_opt; 227 int i = 0; 228 229 if (!ndopts) 230 panic("%s: ndopts == NULL", __func__); 231 if (!ndopts->nd_opts_last) 232 panic("%s: uninitialized ndopts", __func__); 233 if (!ndopts->nd_opts_search) 234 return 0; 235 236 while (1) { 237 nd_opt = nd6_option(ndopts); 238 if (!nd_opt && !ndopts->nd_opts_last) { 239 /* 240 * Message validation requires that all included 241 * options have a length that is greater than zero. 242 */ 243 icmp6stat_inc(icp6s_nd_badopt); 244 bzero(ndopts, sizeof(*ndopts)); 245 return -1; 246 } 247 248 if (!nd_opt) 249 goto skip1; 250 251 switch (nd_opt->nd_opt_type) { 252 case ND_OPT_SOURCE_LINKADDR: 253 case ND_OPT_TARGET_LINKADDR: 254 case ND_OPT_MTU: 255 case ND_OPT_REDIRECTED_HEADER: 256 if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) { 257 nd6log((LOG_INFO, 258 "duplicated ND6 option found (type=%d)\n", 259 nd_opt->nd_opt_type)); 260 /* XXX bark? */ 261 } else { 262 ndopts->nd_opt_array[nd_opt->nd_opt_type] 263 = nd_opt; 264 } 265 break; 266 case ND_OPT_PREFIX_INFORMATION: 267 if (ndopts->nd_opt_array[nd_opt->nd_opt_type] == 0) { 268 ndopts->nd_opt_array[nd_opt->nd_opt_type] 269 = nd_opt; 270 } 271 ndopts->nd_opts_pi_end = 272 (struct nd_opt_prefix_info *)nd_opt; 273 break; 274 default: 275 /* 276 * Unknown options must be silently ignored, 277 * to accommodate future extension to the protocol. 278 */ 279 nd6log((LOG_DEBUG, 280 "nd6_options: unsupported option %d - " 281 "option ignored\n", nd_opt->nd_opt_type)); 282 } 283 284 skip1: 285 i++; 286 if (i > nd6_maxndopt) { 287 icmp6stat_inc(icp6s_nd_toomanyopt); 288 nd6log((LOG_INFO, "too many loop in nd opt\n")); 289 break; 290 } 291 292 if (ndopts->nd_opts_done) 293 break; 294 } 295 296 return 0; 297 } 298 299 /* 300 * ND6 timer routine to handle ND6 entries 301 */ 302 void 303 nd6_llinfo_settimer(struct llinfo_nd6 *ln, unsigned int secs) 304 { 305 time_t expire = getuptime() + secs; 306 307 NET_ASSERT_LOCKED(); 308 KASSERT(!ISSET(ln->ln_rt->rt_flags, RTF_LOCAL)); 309 310 ln->ln_rt->rt_expire = expire; 311 if (!timeout_pending(&nd6_timer_to) || expire < nd6_timer_next) { 312 nd6_timer_next = expire; 313 timeout_add_sec(&nd6_timer_to, secs); 314 } 315 } 316 317 void 318 nd6_timer(void *arg) 319 { 320 struct llinfo_nd6 *ln, *nln; 321 time_t expire = getuptime() + nd6_gctimer; 322 int secs; 323 324 NET_LOCK(); 325 TAILQ_FOREACH_SAFE(ln, &nd6_list, ln_list, nln) { 326 struct rtentry *rt = ln->ln_rt; 327 328 if (rt->rt_expire && rt->rt_expire <= getuptime()) 329 if (nd6_llinfo_timer(rt)) 330 continue; 331 332 if (rt->rt_expire && rt->rt_expire < expire) 333 expire = rt->rt_expire; 334 } 335 336 secs = expire - getuptime(); 337 if (secs < 0) 338 secs = 0; 339 if (!TAILQ_EMPTY(&nd6_list)) { 340 nd6_timer_next = getuptime() + secs; 341 timeout_add_sec(&nd6_timer_to, secs); 342 } 343 344 NET_UNLOCK(); 345 } 346 347 /* 348 * ND timer state handling. 349 * 350 * Returns 1 if `rt' should no longer be used, 0 otherwise. 351 */ 352 int 353 nd6_llinfo_timer(struct rtentry *rt) 354 { 355 struct llinfo_nd6 *ln = (struct llinfo_nd6 *)rt->rt_llinfo; 356 struct sockaddr_in6 *dst = satosin6(rt_key(rt)); 357 struct ifnet *ifp; 358 struct nd_ifinfo *ndi = NULL; 359 360 NET_ASSERT_LOCKED(); 361 362 if ((ifp = if_get(rt->rt_ifidx)) == NULL) 363 return 1; 364 365 ndi = ND_IFINFO(ifp); 366 367 switch (ln->ln_state) { 368 case ND6_LLINFO_INCOMPLETE: 369 if (ln->ln_asked < nd6_mmaxtries) { 370 ln->ln_asked++; 371 nd6_llinfo_settimer(ln, ndi->retrans / 1000); 372 nd6_ns_output(ifp, NULL, &dst->sin6_addr, ln, 0); 373 } else { 374 struct mbuf *m = ln->ln_hold; 375 if (m) { 376 ln->ln_hold = NULL; 377 /* 378 * Fake rcvif to make the ICMP error 379 * more helpful in diagnosing for the 380 * receiver. 381 * XXX: should we consider 382 * older rcvif? 383 */ 384 m->m_pkthdr.ph_ifidx = rt->rt_ifidx; 385 386 icmp6_error(m, ICMP6_DST_UNREACH, 387 ICMP6_DST_UNREACH_ADDR, 0); 388 if (ln->ln_hold == m) { 389 /* m is back in ln_hold. Discard. */ 390 m_freem(ln->ln_hold); 391 ln->ln_hold = NULL; 392 } 393 } 394 nd6_free(rt); 395 ln = NULL; 396 } 397 break; 398 case ND6_LLINFO_REACHABLE: 399 if (!ND6_LLINFO_PERMANENT(ln)) { 400 ln->ln_state = ND6_LLINFO_STALE; 401 nd6_llinfo_settimer(ln, nd6_gctimer); 402 } 403 break; 404 405 case ND6_LLINFO_STALE: 406 case ND6_LLINFO_PURGE: 407 /* Garbage Collection(RFC 2461 5.3) */ 408 if (!ND6_LLINFO_PERMANENT(ln)) { 409 nd6_free(rt); 410 ln = NULL; 411 } 412 break; 413 414 case ND6_LLINFO_DELAY: 415 if (ndi) { 416 /* We need NUD */ 417 ln->ln_asked = 1; 418 ln->ln_state = ND6_LLINFO_PROBE; 419 nd6_llinfo_settimer(ln, ndi->retrans / 1000); 420 nd6_ns_output(ifp, &dst->sin6_addr, 421 &dst->sin6_addr, ln, 0); 422 } 423 break; 424 case ND6_LLINFO_PROBE: 425 if (ln->ln_asked < nd6_umaxtries) { 426 ln->ln_asked++; 427 nd6_llinfo_settimer(ln, ndi->retrans / 1000); 428 nd6_ns_output(ifp, &dst->sin6_addr, 429 &dst->sin6_addr, ln, 0); 430 } else { 431 nd6_free(rt); 432 ln = NULL; 433 } 434 break; 435 } 436 437 if_put(ifp); 438 439 return (ln == NULL); 440 } 441 442 void 443 nd6_expire_timer_update(struct in6_ifaddr *ia6) 444 { 445 time_t expire_time = INT64_MAX; 446 int secs; 447 448 KERNEL_ASSERT_LOCKED(); 449 450 if (ia6->ia6_lifetime.ia6t_vltime != ND6_INFINITE_LIFETIME) 451 expire_time = ia6->ia6_lifetime.ia6t_expire; 452 453 if (!(ia6->ia6_flags & IN6_IFF_DEPRECATED) && 454 ia6->ia6_lifetime.ia6t_pltime != ND6_INFINITE_LIFETIME && 455 expire_time > ia6->ia6_lifetime.ia6t_preferred) 456 expire_time = ia6->ia6_lifetime.ia6t_preferred; 457 458 if (expire_time == INT64_MAX) 459 return; 460 461 /* 462 * IFA6_IS_INVALID() and IFA6_IS_DEPRECATED() check for uptime 463 * greater than ia6t_expire or ia6t_preferred, not greater or equal. 464 * Schedule timeout one second later so that either IFA6_IS_INVALID() 465 * or IFA6_IS_DEPRECATED() is true. 466 */ 467 expire_time++; 468 469 if (!timeout_pending(&nd6_expire_timeout) || 470 nd6_expire_next > expire_time) { 471 secs = expire_time - getuptime(); 472 if (secs < 0) 473 secs = 0; 474 475 timeout_add_sec(&nd6_expire_timeout, secs); 476 nd6_expire_next = expire_time; 477 } 478 } 479 480 /* 481 * Expire interface addresses. 482 */ 483 void 484 nd6_expire(void *unused) 485 { 486 struct ifnet *ifp; 487 488 KERNEL_LOCK(); 489 NET_LOCK(); 490 491 TAILQ_FOREACH(ifp, &ifnet, if_list) { 492 struct ifaddr *ifa, *nifa; 493 struct in6_ifaddr *ia6; 494 495 TAILQ_FOREACH_SAFE(ifa, &ifp->if_addrlist, ifa_list, nifa) { 496 if (ifa->ifa_addr->sa_family != AF_INET6) 497 continue; 498 ia6 = ifatoia6(ifa); 499 /* check address lifetime */ 500 if (IFA6_IS_INVALID(ia6)) { 501 in6_purgeaddr(&ia6->ia_ifa); 502 } else { 503 if (IFA6_IS_DEPRECATED(ia6)) 504 ia6->ia6_flags |= IN6_IFF_DEPRECATED; 505 nd6_expire_timer_update(ia6); 506 } 507 } 508 } 509 510 NET_UNLOCK(); 511 KERNEL_UNLOCK(); 512 } 513 514 void 515 nd6_expire_timer(void *unused) 516 { 517 task_add(net_tq(0), &nd6_expire_task); 518 } 519 520 /* 521 * Nuke neighbor cache/prefix/default router management table, right before 522 * ifp goes away. 523 */ 524 void 525 nd6_purge(struct ifnet *ifp) 526 { 527 struct llinfo_nd6 *ln, *nln; 528 529 NET_ASSERT_LOCKED(); 530 531 /* 532 * Nuke neighbor cache entries for the ifp. 533 */ 534 TAILQ_FOREACH_SAFE(ln, &nd6_list, ln_list, nln) { 535 struct rtentry *rt; 536 struct sockaddr_dl *sdl; 537 538 rt = ln->ln_rt; 539 if (rt != NULL && rt->rt_gateway != NULL && 540 rt->rt_gateway->sa_family == AF_LINK) { 541 sdl = satosdl(rt->rt_gateway); 542 if (sdl->sdl_index == ifp->if_index) 543 nd6_free(rt); 544 } 545 } 546 } 547 548 struct rtentry * 549 nd6_lookup(struct in6_addr *addr6, int create, struct ifnet *ifp, 550 u_int rtableid) 551 { 552 struct rtentry *rt; 553 struct sockaddr_in6 sin6; 554 int flags; 555 556 bzero(&sin6, sizeof(sin6)); 557 sin6.sin6_len = sizeof(struct sockaddr_in6); 558 sin6.sin6_family = AF_INET6; 559 sin6.sin6_addr = *addr6; 560 flags = (create) ? RT_RESOLVE : 0; 561 562 rt = rtalloc(sin6tosa(&sin6), flags, rtableid); 563 if (rt != NULL && (rt->rt_flags & RTF_LLINFO) == 0) { 564 /* 565 * This is the case for the default route. 566 * If we want to create a neighbor cache for the address, we 567 * should free the route for the destination and allocate an 568 * interface route. 569 */ 570 if (create) { 571 rtfree(rt); 572 rt = NULL; 573 } 574 } 575 if (rt == NULL) { 576 if (create && ifp) { 577 struct rt_addrinfo info; 578 struct ifaddr *ifa; 579 int error; 580 581 /* 582 * If no route is available and create is set, 583 * we allocate a host route for the destination 584 * and treat it like an interface route. 585 * This hack is necessary for a neighbor which can't 586 * be covered by our own prefix. 587 */ 588 ifa = ifaof_ifpforaddr(sin6tosa(&sin6), ifp); 589 if (ifa == NULL) 590 return (NULL); 591 592 /* 593 * Create a new route. RTF_LLINFO is necessary 594 * to create a Neighbor Cache entry for the 595 * destination in nd6_rtrequest which will be 596 * called in rtrequest. 597 */ 598 bzero(&info, sizeof(info)); 599 info.rti_ifa = ifa; 600 info.rti_flags = RTF_HOST | RTF_LLINFO; 601 info.rti_info[RTAX_DST] = sin6tosa(&sin6); 602 info.rti_info[RTAX_GATEWAY] = sdltosa(ifp->if_sadl); 603 error = rtrequest(RTM_ADD, &info, RTP_CONNECTED, &rt, 604 rtableid); 605 if (error) 606 return (NULL); 607 if (rt->rt_llinfo != NULL) { 608 struct llinfo_nd6 *ln = 609 (struct llinfo_nd6 *)rt->rt_llinfo; 610 ln->ln_state = ND6_LLINFO_NOSTATE; 611 } 612 } else 613 return (NULL); 614 } 615 /* 616 * Validation for the entry. 617 * Note that the check for rt_llinfo is necessary because a cloned 618 * route from a parent route that has the L flag (e.g. the default 619 * route to a p2p interface) may have the flag, too, while the 620 * destination is not actually a neighbor. 621 */ 622 if ((rt->rt_flags & RTF_GATEWAY) || (rt->rt_flags & RTF_LLINFO) == 0 || 623 rt->rt_gateway->sa_family != AF_LINK || rt->rt_llinfo == NULL || 624 (ifp != NULL && rt->rt_ifidx != ifp->if_index)) { 625 if (create) { 626 char addr[INET6_ADDRSTRLEN]; 627 nd6log((LOG_DEBUG, "%s: failed to lookup %s (if=%s)\n", 628 __func__, 629 inet_ntop(AF_INET6, addr6, addr, sizeof(addr)), 630 ifp ? ifp->if_xname : "unspec")); 631 } 632 rtfree(rt); 633 return (NULL); 634 } 635 return (rt); 636 } 637 638 /* 639 * Detect if a given IPv6 address identifies a neighbor on a given link. 640 * XXX: should take care of the destination of a p2p link? 641 */ 642 int 643 nd6_is_addr_neighbor(struct sockaddr_in6 *addr, struct ifnet *ifp) 644 { 645 struct in6_ifaddr *ia6; 646 struct ifaddr *ifa; 647 struct rtentry *rt; 648 649 /* 650 * A link-local address is always a neighbor. 651 * XXX: we should use the sin6_scope_id field rather than the embedded 652 * interface index. 653 * XXX: a link does not necessarily specify a single interface. 654 */ 655 if (IN6_IS_ADDR_LINKLOCAL(&addr->sin6_addr) && 656 ntohs(*(u_int16_t *)&addr->sin6_addr.s6_addr[2]) == ifp->if_index) 657 return (1); 658 659 TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) { 660 if (ifa->ifa_addr->sa_family != AF_INET6) 661 continue; 662 663 ia6 = ifatoia6(ifa); 664 665 /* Prefix check down below. */ 666 if (ia6->ia6_flags & IN6_IFF_AUTOCONF) 667 continue; 668 669 if (IN6_ARE_MASKED_ADDR_EQUAL(&addr->sin6_addr, 670 &ia6->ia_addr.sin6_addr, 671 &ia6->ia_prefixmask.sin6_addr)) 672 return (1); 673 } 674 675 /* 676 * Even if the address matches none of our addresses, it might be 677 * in the neighbor cache. 678 */ 679 rt = nd6_lookup(&addr->sin6_addr, 0, ifp, ifp->if_rdomain); 680 if (rt != NULL) { 681 rtfree(rt); 682 return (1); 683 } 684 685 return (0); 686 } 687 688 void 689 nd6_invalidate(struct rtentry *rt) 690 { 691 struct llinfo_nd6 *ln = (struct llinfo_nd6 *)rt->rt_llinfo; 692 struct sockaddr_dl *sdl = satosdl(rt->rt_gateway); 693 694 m_freem(ln->ln_hold); 695 sdl->sdl_alen = 0; 696 ln->ln_hold = NULL; 697 ln->ln_state = ND6_LLINFO_INCOMPLETE; 698 ln->ln_asked = 0; 699 } 700 701 /* 702 * Free an nd6 llinfo entry. 703 * Since the function would cause significant changes in the kernel, DO NOT 704 * make it global, unless you have a strong reason for the change, and are sure 705 * that the change is safe. 706 */ 707 void 708 nd6_free(struct rtentry *rt) 709 { 710 struct llinfo_nd6 *ln = (struct llinfo_nd6 *)rt->rt_llinfo; 711 struct in6_addr in6 = satosin6(rt_key(rt))->sin6_addr; 712 struct ifnet *ifp; 713 714 NET_ASSERT_LOCKED(); 715 716 ifp = if_get(rt->rt_ifidx); 717 718 if (!ip6_forwarding) { 719 if (ln->ln_router) { 720 /* 721 * rt6_flush must be called whether or not the neighbor 722 * is in the Default Router List. 723 * See a corresponding comment in nd6_na_input(). 724 */ 725 rt6_flush(&in6, ifp); 726 } 727 } 728 729 KASSERT(!ISSET(rt->rt_flags, RTF_LOCAL)); 730 nd6_invalidate(rt); 731 732 /* 733 * Detach the route from the routing tree and the list of neighbor 734 * caches, and disable the route entry not to be used in already 735 * cached routes. 736 */ 737 if (!ISSET(rt->rt_flags, RTF_STATIC|RTF_CACHED)) 738 rtdeletemsg(rt, ifp, ifp->if_rdomain); 739 740 if_put(ifp); 741 } 742 743 /* 744 * Upper-layer reachability hint for Neighbor Unreachability Detection. 745 * 746 * XXX cost-effective methods? 747 */ 748 void 749 nd6_nud_hint(struct rtentry *rt) 750 { 751 struct llinfo_nd6 *ln; 752 struct ifnet *ifp; 753 754 ifp = if_get(rt->rt_ifidx); 755 if (ifp == NULL) 756 return; 757 758 if ((rt->rt_flags & RTF_GATEWAY) != 0 || 759 (rt->rt_flags & RTF_LLINFO) == 0 || 760 rt->rt_llinfo == NULL || rt->rt_gateway == NULL || 761 rt->rt_gateway->sa_family != AF_LINK) { 762 /* This is not a host route. */ 763 goto out; 764 } 765 766 ln = (struct llinfo_nd6 *)rt->rt_llinfo; 767 if (ln->ln_state < ND6_LLINFO_REACHABLE) 768 goto out; 769 770 /* 771 * if we get upper-layer reachability confirmation many times, 772 * it is possible we have false information. 773 */ 774 ln->ln_byhint++; 775 if (ln->ln_byhint > nd6_maxnudhint) 776 goto out; 777 778 ln->ln_state = ND6_LLINFO_REACHABLE; 779 if (!ND6_LLINFO_PERMANENT(ln)) 780 nd6_llinfo_settimer(ln, ND_IFINFO(ifp)->reachable); 781 out: 782 if_put(ifp); 783 } 784 785 void 786 nd6_rtrequest(struct ifnet *ifp, int req, struct rtentry *rt) 787 { 788 struct sockaddr *gate = rt->rt_gateway; 789 struct llinfo_nd6 *ln = (struct llinfo_nd6 *)rt->rt_llinfo; 790 struct ifaddr *ifa; 791 792 if (ISSET(rt->rt_flags, RTF_GATEWAY|RTF_MULTICAST|RTF_MPLS)) 793 return; 794 795 if (nd6_need_cache(ifp) == 0 && (rt->rt_flags & RTF_HOST) == 0) { 796 /* 797 * This is probably an interface direct route for a link 798 * which does not need neighbor caches (e.g. fe80::%lo0/64). 799 * We do not need special treatment below for such a route. 800 * Moreover, the RTF_LLINFO flag which would be set below 801 * would annoy the ndp(8) command. 802 */ 803 return; 804 } 805 806 if (req == RTM_RESOLVE && nd6_need_cache(ifp) == 0) { 807 /* 808 * For routing daemons like ospf6d we allow neighbor discovery 809 * based on the cloning route only. This allows us to sent 810 * packets directly into a network without having an address 811 * with matching prefix on the interface. If the cloning 812 * route is used for an stf interface, we would mistakenly 813 * make a neighbor cache for the host route, and would see 814 * strange neighbor solicitation for the corresponding 815 * destination. In order to avoid confusion, we check if the 816 * interface is suitable for neighbor discovery, and stop the 817 * process if not. Additionally, we remove the LLINFO flag 818 * so that ndp(8) will not try to get the neighbor information 819 * of the destination. 820 */ 821 rt->rt_flags &= ~RTF_LLINFO; 822 return; 823 } 824 825 switch (req) { 826 case RTM_ADD: 827 if ((rt->rt_flags & RTF_CLONING) || 828 ((rt->rt_flags & (RTF_LLINFO | RTF_LOCAL)) && ln == NULL)) { 829 if (ln != NULL) 830 nd6_llinfo_settimer(ln, 0); 831 if ((rt->rt_flags & RTF_CLONING) != 0) 832 break; 833 } 834 /* 835 * In IPv4 code, we try to announce new RTF_ANNOUNCE entry here. 836 * We don't do that here since llinfo is not ready yet. 837 * 838 * There are also couple of other things to be discussed: 839 * - unsolicited NA code needs improvement beforehand 840 * - RFC2461 says we MAY send multicast unsolicited NA 841 * (7.2.6 paragraph 4), however, it also says that we 842 * SHOULD provide a mechanism to prevent multicast NA storm. 843 * we don't have anything like it right now. 844 * note that the mechanism needs a mutual agreement 845 * between proxies, which means that we need to implement 846 * a new protocol, or a new kludge. 847 * - from RFC2461 6.2.4, host MUST NOT send an unsolicited NA. 848 * we need to check ip6forwarding before sending it. 849 * (or should we allow proxy ND configuration only for 850 * routers? there's no mention about proxy ND from hosts) 851 */ 852 #if 0 853 /* XXX it does not work */ 854 if (rt->rt_flags & RTF_ANNOUNCE) 855 nd6_na_output(ifp, 856 &satosin6(rt_key(rt))->sin6_addr, 857 &satosin6(rt_key(rt))->sin6_addr, 858 ip6_forwarding ? ND_NA_FLAG_ROUTER : 0, 859 1, NULL); 860 #endif 861 /* FALLTHROUGH */ 862 case RTM_RESOLVE: 863 if (gate->sa_family != AF_LINK || 864 gate->sa_len < sizeof(struct sockaddr_dl)) { 865 log(LOG_DEBUG, "%s: bad gateway value: %s\n", 866 __func__, ifp->if_xname); 867 break; 868 } 869 satosdl(gate)->sdl_type = ifp->if_type; 870 satosdl(gate)->sdl_index = ifp->if_index; 871 if (ln != NULL) 872 break; /* This happens on a route change */ 873 /* 874 * Case 2: This route may come from cloning, or a manual route 875 * add with a LL address. 876 */ 877 ln = pool_get(&nd6_pool, PR_NOWAIT | PR_ZERO); 878 rt->rt_llinfo = (caddr_t)ln; 879 if (ln == NULL) { 880 log(LOG_DEBUG, "%s: pool get failed\n", __func__); 881 break; 882 } 883 nd6_inuse++; 884 nd6_allocated++; 885 ln->ln_rt = rt; 886 /* this is required for "ndp" command. - shin */ 887 if (req == RTM_ADD) { 888 /* 889 * gate should have some valid AF_LINK entry, 890 * and ln expire should have some lifetime 891 * which is specified by ndp command. 892 */ 893 ln->ln_state = ND6_LLINFO_REACHABLE; 894 ln->ln_byhint = 0; 895 } else { 896 /* 897 * When req == RTM_RESOLVE, rt is created and 898 * initialized in rtrequest(), so rt_expire is 0. 899 */ 900 ln->ln_state = ND6_LLINFO_NOSTATE; 901 nd6_llinfo_settimer(ln, 0); 902 } 903 rt->rt_flags |= RTF_LLINFO; 904 TAILQ_INSERT_HEAD(&nd6_list, ln, ln_list); 905 906 /* 907 * If we have too many cache entries, initiate immediate 908 * purging for some "less recently used" entries. Note that 909 * we cannot directly call nd6_free() here because it would 910 * cause re-entering rtable related routines triggering an LOR 911 * problem for FreeBSD. 912 */ 913 if (ip6_neighborgcthresh >= 0 && 914 nd6_inuse >= ip6_neighborgcthresh) { 915 int i; 916 917 for (i = 0; i < 10; i++) { 918 struct llinfo_nd6 *ln_end; 919 920 ln_end = TAILQ_LAST(&nd6_list, llinfo_nd6_head); 921 if (ln_end == ln) 922 break; 923 924 /* Move this entry to the head */ 925 TAILQ_REMOVE(&nd6_list, ln_end, ln_list); 926 TAILQ_INSERT_HEAD(&nd6_list, ln_end, ln_list); 927 928 if (ND6_LLINFO_PERMANENT(ln_end)) 929 continue; 930 931 if (ln_end->ln_state > ND6_LLINFO_INCOMPLETE) 932 ln_end->ln_state = ND6_LLINFO_STALE; 933 else 934 ln_end->ln_state = ND6_LLINFO_PURGE; 935 nd6_llinfo_settimer(ln_end, 0); 936 } 937 } 938 939 /* 940 * check if rt_key(rt) is one of my address assigned 941 * to the interface. 942 */ 943 ifa = &in6ifa_ifpwithaddr(ifp, 944 &satosin6(rt_key(rt))->sin6_addr)->ia_ifa; 945 if (ifa) { 946 ln->ln_state = ND6_LLINFO_REACHABLE; 947 ln->ln_byhint = 0; 948 rt->rt_expire = 0; 949 KASSERT(ifa == rt->rt_ifa); 950 } else if (rt->rt_flags & RTF_ANNOUNCE) { 951 ln->ln_state = ND6_LLINFO_REACHABLE; 952 ln->ln_byhint = 0; 953 rt->rt_expire = 0; 954 955 /* join solicited node multicast for proxy ND */ 956 if (ifp->if_flags & IFF_MULTICAST) { 957 struct in6_addr llsol; 958 int error; 959 960 llsol = satosin6(rt_key(rt))->sin6_addr; 961 llsol.s6_addr16[0] = htons(0xff02); 962 llsol.s6_addr16[1] = htons(ifp->if_index); 963 llsol.s6_addr32[1] = 0; 964 llsol.s6_addr32[2] = htonl(1); 965 llsol.s6_addr8[12] = 0xff; 966 967 if (in6_addmulti(&llsol, ifp, &error)) { 968 char addr[INET6_ADDRSTRLEN]; 969 nd6log((LOG_ERR, "%s: failed to join " 970 "%s (errno=%d)\n", ifp->if_xname, 971 inet_ntop(AF_INET6, &llsol, 972 addr, sizeof(addr)), 973 error)); 974 } 975 } 976 } 977 break; 978 979 case RTM_DELETE: 980 if (ln == NULL) 981 break; 982 /* leave from solicited node multicast for proxy ND */ 983 if ((rt->rt_flags & RTF_ANNOUNCE) != 0 && 984 (ifp->if_flags & IFF_MULTICAST) != 0) { 985 struct in6_addr llsol; 986 struct in6_multi *in6m; 987 988 llsol = satosin6(rt_key(rt))->sin6_addr; 989 llsol.s6_addr16[0] = htons(0xff02); 990 llsol.s6_addr16[1] = htons(ifp->if_index); 991 llsol.s6_addr32[1] = 0; 992 llsol.s6_addr32[2] = htonl(1); 993 llsol.s6_addr8[12] = 0xff; 994 995 IN6_LOOKUP_MULTI(llsol, ifp, in6m); 996 if (in6m) 997 in6_delmulti(in6m); 998 } 999 nd6_inuse--; 1000 TAILQ_REMOVE(&nd6_list, ln, ln_list); 1001 rt->rt_expire = 0; 1002 rt->rt_llinfo = NULL; 1003 rt->rt_flags &= ~RTF_LLINFO; 1004 m_freem(ln->ln_hold); 1005 pool_put(&nd6_pool, ln); 1006 break; 1007 1008 case RTM_INVALIDATE: 1009 if (ln == NULL) 1010 break; 1011 if (!ISSET(rt->rt_flags, RTF_LOCAL)) 1012 nd6_invalidate(rt); 1013 break; 1014 } 1015 } 1016 1017 int 1018 nd6_ioctl(u_long cmd, caddr_t data, struct ifnet *ifp) 1019 { 1020 struct in6_ndireq *ndi = (struct in6_ndireq *)data; 1021 struct in6_nbrinfo *nbi = (struct in6_nbrinfo *)data; 1022 struct rtentry *rt; 1023 1024 switch (cmd) { 1025 case SIOCGIFINFO_IN6: 1026 NET_RLOCK_IN_IOCTL(); 1027 ndi->ndi = *ND_IFINFO(ifp); 1028 NET_RUNLOCK_IN_IOCTL(); 1029 return (0); 1030 case SIOCGNBRINFO_IN6: 1031 { 1032 struct llinfo_nd6 *ln; 1033 struct in6_addr nb_addr = nbi->addr; /* make local for safety */ 1034 time_t expire; 1035 1036 NET_RLOCK_IN_IOCTL(); 1037 /* 1038 * XXX: KAME specific hack for scoped addresses 1039 * XXXX: for other scopes than link-local? 1040 */ 1041 if (IN6_IS_ADDR_LINKLOCAL(&nbi->addr) || 1042 IN6_IS_ADDR_MC_LINKLOCAL(&nbi->addr)) { 1043 u_int16_t *idp = (u_int16_t *)&nb_addr.s6_addr[2]; 1044 1045 if (*idp == 0) 1046 *idp = htons(ifp->if_index); 1047 } 1048 1049 rt = nd6_lookup(&nb_addr, 0, ifp, ifp->if_rdomain); 1050 if (rt == NULL || 1051 (ln = (struct llinfo_nd6 *)rt->rt_llinfo) == NULL) { 1052 rtfree(rt); 1053 NET_RUNLOCK_IN_IOCTL(); 1054 return (EINVAL); 1055 } 1056 expire = ln->ln_rt->rt_expire; 1057 if (expire != 0) { 1058 expire -= getuptime(); 1059 expire += gettime(); 1060 } 1061 1062 nbi->state = ln->ln_state; 1063 nbi->asked = ln->ln_asked; 1064 nbi->isrouter = ln->ln_router; 1065 nbi->expire = expire; 1066 1067 rtfree(rt); 1068 NET_RUNLOCK_IN_IOCTL(); 1069 return (0); 1070 } 1071 } 1072 return (0); 1073 } 1074 1075 /* 1076 * Create neighbor cache entry and cache link-layer address, 1077 * on reception of inbound ND6 packets. (RS/RA/NS/redirect) 1078 * 1079 * type - ICMP6 type 1080 * code - type dependent information 1081 */ 1082 void 1083 nd6_cache_lladdr(struct ifnet *ifp, struct in6_addr *from, char *lladdr, 1084 int lladdrlen, int type, int code) 1085 { 1086 struct rtentry *rt = NULL; 1087 struct llinfo_nd6 *ln = NULL; 1088 int is_newentry; 1089 struct sockaddr_dl *sdl = NULL; 1090 int do_update; 1091 int olladdr; 1092 int llchange; 1093 int newstate = 0; 1094 1095 if (!ifp) 1096 panic("%s: ifp == NULL", __func__); 1097 if (!from) 1098 panic("%s: from == NULL", __func__); 1099 1100 /* nothing must be updated for unspecified address */ 1101 if (IN6_IS_ADDR_UNSPECIFIED(from)) 1102 return; 1103 1104 /* 1105 * Validation about ifp->if_addrlen and lladdrlen must be done in 1106 * the caller. 1107 * 1108 * XXX If the link does not have link-layer address, what should 1109 * we do? (ifp->if_addrlen == 0) 1110 * Spec says nothing in sections for RA, RS and NA. There's small 1111 * description on it in NS section (RFC 2461 7.2.3). 1112 */ 1113 1114 rt = nd6_lookup(from, 0, ifp, ifp->if_rdomain); 1115 if (rt == NULL) { 1116 rt = nd6_lookup(from, 1, ifp, ifp->if_rdomain); 1117 is_newentry = 1; 1118 } else { 1119 /* do not overwrite local or static entry */ 1120 if (ISSET(rt->rt_flags, RTF_STATIC|RTF_LOCAL)) { 1121 rtfree(rt); 1122 return; 1123 } 1124 is_newentry = 0; 1125 } 1126 1127 if (!rt) 1128 return; 1129 if ((rt->rt_flags & (RTF_GATEWAY | RTF_LLINFO)) != RTF_LLINFO) { 1130 fail: 1131 nd6_free(rt); 1132 rtfree(rt); 1133 return; 1134 } 1135 ln = (struct llinfo_nd6 *)rt->rt_llinfo; 1136 if (ln == NULL) 1137 goto fail; 1138 if (rt->rt_gateway == NULL) 1139 goto fail; 1140 if (rt->rt_gateway->sa_family != AF_LINK) 1141 goto fail; 1142 sdl = satosdl(rt->rt_gateway); 1143 1144 olladdr = (sdl->sdl_alen) ? 1 : 0; 1145 if (olladdr && lladdr) { 1146 if (bcmp(lladdr, LLADDR(sdl), ifp->if_addrlen)) 1147 llchange = 1; 1148 else 1149 llchange = 0; 1150 } else 1151 llchange = 0; 1152 1153 /* 1154 * newentry olladdr lladdr llchange (*=record) 1155 * 0 n n -- (1) 1156 * 0 y n -- (2) 1157 * 0 n y -- (3) * STALE 1158 * 0 y y n (4) * 1159 * 0 y y y (5) * STALE 1160 * 1 -- n -- (6) NOSTATE(= PASSIVE) 1161 * 1 -- y -- (7) * STALE 1162 */ 1163 1164 if (llchange) { 1165 char addr[INET6_ADDRSTRLEN]; 1166 log(LOG_INFO, "ndp info overwritten for %s by %s on %s\n", 1167 inet_ntop(AF_INET6, from, addr, sizeof(addr)), 1168 ether_sprintf(lladdr), ifp->if_xname); 1169 } 1170 if (lladdr) { /* (3-5) and (7) */ 1171 /* 1172 * Record source link-layer address 1173 * XXX is it dependent to ifp->if_type? 1174 */ 1175 sdl->sdl_alen = ifp->if_addrlen; 1176 bcopy(lladdr, LLADDR(sdl), ifp->if_addrlen); 1177 } 1178 1179 if (!is_newentry) { 1180 if ((!olladdr && lladdr) || /* (3) */ 1181 (olladdr && lladdr && llchange)) { /* (5) */ 1182 do_update = 1; 1183 newstate = ND6_LLINFO_STALE; 1184 } else /* (1-2,4) */ 1185 do_update = 0; 1186 } else { 1187 do_update = 1; 1188 if (!lladdr) /* (6) */ 1189 newstate = ND6_LLINFO_NOSTATE; 1190 else /* (7) */ 1191 newstate = ND6_LLINFO_STALE; 1192 } 1193 1194 if (do_update) { 1195 /* 1196 * Update the state of the neighbor cache. 1197 */ 1198 ln->ln_state = newstate; 1199 1200 if (ln->ln_state == ND6_LLINFO_STALE) { 1201 /* 1202 * Since nd6_resolve() in ifp->if_output() will cause 1203 * state transition to DELAY and reset the timer, 1204 * we must set the timer now, although it is actually 1205 * meaningless. 1206 */ 1207 nd6_llinfo_settimer(ln, nd6_gctimer); 1208 1209 if (ln->ln_hold) { 1210 struct mbuf *n = ln->ln_hold; 1211 ln->ln_hold = NULL; 1212 /* 1213 * we assume ifp is not a p2p here, so just 1214 * set the 2nd argument as the 1st one. 1215 */ 1216 ifp->if_output(ifp, n, rt_key(rt), rt); 1217 if (ln->ln_hold == n) { 1218 /* n is back in ln_hold. Discard. */ 1219 m_freem(ln->ln_hold); 1220 ln->ln_hold = NULL; 1221 } 1222 } 1223 } else if (ln->ln_state == ND6_LLINFO_INCOMPLETE) { 1224 /* probe right away */ 1225 nd6_llinfo_settimer(ln, 0); 1226 } 1227 } 1228 1229 /* 1230 * ICMP6 type dependent behavior. 1231 * 1232 * NS: clear IsRouter if new entry 1233 * RS: clear IsRouter 1234 * RA: set IsRouter if there's lladdr 1235 * redir: clear IsRouter if new entry 1236 * 1237 * RA case, (1): 1238 * The spec says that we must set IsRouter in the following cases: 1239 * - If lladdr exist, set IsRouter. This means (1-5). 1240 * - If it is old entry (!newentry), set IsRouter. This means (7). 1241 * So, based on the spec, in (1-5) and (7) cases we must set IsRouter. 1242 * A question arises for (1) case. (1) case has no lladdr in the 1243 * neighbor cache, this is similar to (6). 1244 * This case is rare but we figured that we MUST NOT set IsRouter. 1245 * 1246 * newentry olladdr lladdr llchange NS RS RA redir 1247 * D R 1248 * 0 n n -- (1) c ? s 1249 * 0 y n -- (2) c s s 1250 * 0 n y -- (3) c s s 1251 * 0 y y n (4) c s s 1252 * 0 y y y (5) c s s 1253 * 1 -- n -- (6) c c c s 1254 * 1 -- y -- (7) c c s c s 1255 * 1256 * (c=clear s=set) 1257 */ 1258 switch (type & 0xff) { 1259 case ND_NEIGHBOR_SOLICIT: 1260 /* 1261 * New entry must have is_router flag cleared. 1262 */ 1263 if (is_newentry) /* (6-7) */ 1264 ln->ln_router = 0; 1265 break; 1266 case ND_REDIRECT: 1267 /* 1268 * If the icmp is a redirect to a better router, always set the 1269 * is_router flag. Otherwise, if the entry is newly created, 1270 * clear the flag. [RFC 2461, sec 8.3] 1271 */ 1272 if (code == ND_REDIRECT_ROUTER) 1273 ln->ln_router = 1; 1274 else if (is_newentry) /* (6-7) */ 1275 ln->ln_router = 0; 1276 break; 1277 case ND_ROUTER_SOLICIT: 1278 /* 1279 * is_router flag must always be cleared. 1280 */ 1281 ln->ln_router = 0; 1282 break; 1283 case ND_ROUTER_ADVERT: 1284 /* 1285 * Mark an entry with lladdr as a router. 1286 */ 1287 if ((!is_newentry && (olladdr || lladdr)) || /* (2-5) */ 1288 (is_newentry && lladdr)) { /* (7) */ 1289 ln->ln_router = 1; 1290 } 1291 break; 1292 } 1293 1294 rtfree(rt); 1295 } 1296 1297 void 1298 nd6_slowtimo(void *ignored_arg) 1299 { 1300 struct nd_ifinfo *nd6if; 1301 struct ifnet *ifp; 1302 1303 NET_LOCK(); 1304 1305 timeout_add_sec(&nd6_slowtimo_ch, ND6_SLOWTIMER_INTERVAL); 1306 1307 TAILQ_FOREACH(ifp, &ifnet, if_list) { 1308 nd6if = ND_IFINFO(ifp); 1309 if (nd6if->basereachable && /* already initialized */ 1310 (nd6if->recalctm -= ND6_SLOWTIMER_INTERVAL) <= 0) { 1311 /* 1312 * Since reachable time rarely changes by router 1313 * advertisements, we SHOULD insure that a new random 1314 * value gets recomputed at least once every few hours. 1315 * (RFC 2461, 6.3.4) 1316 */ 1317 nd6if->recalctm = nd6_recalc_reachtm_interval; 1318 nd6if->reachable = ND_COMPUTE_RTIME(nd6if->basereachable); 1319 } 1320 } 1321 NET_UNLOCK(); 1322 } 1323 1324 int 1325 nd6_resolve(struct ifnet *ifp, struct rtentry *rt0, struct mbuf *m, 1326 struct sockaddr *dst, u_char *desten) 1327 { 1328 struct sockaddr_dl *sdl; 1329 struct rtentry *rt; 1330 struct llinfo_nd6 *ln = NULL; 1331 1332 if (m->m_flags & M_MCAST) { 1333 ETHER_MAP_IPV6_MULTICAST(&satosin6(dst)->sin6_addr, desten); 1334 return (0); 1335 } 1336 1337 rt = rt_getll(rt0); 1338 1339 if (ISSET(rt->rt_flags, RTF_REJECT) && 1340 (rt->rt_expire == 0 || getuptime() < rt->rt_expire)) { 1341 m_freem(m); 1342 return (rt == rt0 ? EHOSTDOWN : EHOSTUNREACH); 1343 } 1344 1345 /* 1346 * Address resolution or Neighbor Unreachability Detection 1347 * for the next hop. 1348 * At this point, the destination of the packet must be a unicast 1349 * or an anycast address(i.e. not a multicast). 1350 */ 1351 if (!ISSET(rt->rt_flags, RTF_LLINFO)) { 1352 char addr[INET6_ADDRSTRLEN]; 1353 log(LOG_DEBUG, "%s: %s: route contains no ND information\n", 1354 __func__, inet_ntop(AF_INET6, 1355 &satosin6(rt_key(rt))->sin6_addr, addr, sizeof(addr))); 1356 m_freem(m); 1357 return (EINVAL); 1358 } 1359 1360 if (rt->rt_gateway->sa_family != AF_LINK) { 1361 printf("%s: something odd happens\n", __func__); 1362 m_freem(m); 1363 return (EINVAL); 1364 } 1365 1366 ln = (struct llinfo_nd6 *)rt->rt_llinfo; 1367 KASSERT(ln != NULL); 1368 1369 /* 1370 * Move this entry to the head of the queue so that it is less likely 1371 * for this entry to be a target of forced garbage collection (see 1372 * nd6_rtrequest()). 1373 */ 1374 TAILQ_REMOVE(&nd6_list, ln, ln_list); 1375 TAILQ_INSERT_HEAD(&nd6_list, ln, ln_list); 1376 1377 /* 1378 * The first time we send a packet to a neighbor whose entry is 1379 * STALE, we have to change the state to DELAY and a sets a timer to 1380 * expire in DELAY_FIRST_PROBE_TIME seconds to ensure do 1381 * neighbor unreachability detection on expiration. 1382 * (RFC 2461 7.3.3) 1383 */ 1384 if (ln->ln_state == ND6_LLINFO_STALE) { 1385 ln->ln_asked = 0; 1386 ln->ln_state = ND6_LLINFO_DELAY; 1387 nd6_llinfo_settimer(ln, nd6_delay); 1388 } 1389 1390 /* 1391 * If the neighbor cache entry has a state other than INCOMPLETE 1392 * (i.e. its link-layer address is already resolved), just 1393 * send the packet. 1394 */ 1395 if (ln->ln_state > ND6_LLINFO_INCOMPLETE) { 1396 sdl = satosdl(rt->rt_gateway); 1397 if (sdl->sdl_alen != ETHER_ADDR_LEN) { 1398 char addr[INET6_ADDRSTRLEN]; 1399 log(LOG_DEBUG, "%s: %s: incorrect nd6 information\n", 1400 __func__, 1401 inet_ntop(AF_INET6, &satosin6(dst)->sin6_addr, 1402 addr, sizeof(addr))); 1403 m_freem(m); 1404 return (EINVAL); 1405 } 1406 1407 bcopy(LLADDR(sdl), desten, sdl->sdl_alen); 1408 return (0); 1409 } 1410 1411 /* 1412 * There is a neighbor cache entry, but no ethernet address 1413 * response yet. Replace the held mbuf (if any) with this 1414 * latest one. 1415 */ 1416 if (ln->ln_state == ND6_LLINFO_NOSTATE) 1417 ln->ln_state = ND6_LLINFO_INCOMPLETE; 1418 m_freem(ln->ln_hold); 1419 ln->ln_hold = m; 1420 1421 /* 1422 * If there has been no NS for the neighbor after entering the 1423 * INCOMPLETE state, send the first solicitation. 1424 */ 1425 if (!ND6_LLINFO_PERMANENT(ln) && ln->ln_asked == 0) { 1426 ln->ln_asked++; 1427 nd6_llinfo_settimer(ln, ND_IFINFO(ifp)->retrans / 1000); 1428 nd6_ns_output(ifp, NULL, &satosin6(dst)->sin6_addr, ln, 0); 1429 } 1430 return (EAGAIN); 1431 } 1432 1433 int 1434 nd6_need_cache(struct ifnet *ifp) 1435 { 1436 /* 1437 * RFC2893 says: 1438 * - unidirectional tunnels needs no ND 1439 */ 1440 switch (ifp->if_type) { 1441 case IFT_ETHER: 1442 case IFT_IEEE80211: 1443 case IFT_CARP: 1444 return (1); 1445 default: 1446 return (0); 1447 } 1448 } 1449