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sys/netinet6/nd6.c
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1 /* $OpenBSD: nd6.c,v 1.265 2023/01/24 20:06:16 claudio 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, *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 = opt; 157 last_opt = (struct nd_opt_hdr *)((u_char *)opt + icmp6len); 158 159 while (next_opt != NULL) { 160 int olen; 161 162 nd_opt = next_opt; 163 164 /* make sure nd_opt_len is inside the buffer */ 165 if ((caddr_t)&nd_opt->nd_opt_len >= (caddr_t)last_opt) 166 goto invalid; 167 168 /* every option must have a length greater than zero */ 169 olen = nd_opt->nd_opt_len << 3; 170 if (olen == 0) 171 goto invalid; 172 173 next_opt = (struct nd_opt_hdr *)((caddr_t)nd_opt + olen); 174 if (next_opt > last_opt) { 175 /* option overruns the end of buffer */ 176 goto invalid; 177 } else if (next_opt == last_opt) { 178 /* reached the end of options chain */ 179 next_opt = NULL; 180 } 181 182 switch (nd_opt->nd_opt_type) { 183 case ND_OPT_SOURCE_LINKADDR: 184 if (ndopts->nd_opts_src_lladdr != NULL) 185 nd6log((LOG_INFO, "duplicated ND6 option found " 186 "(type=%d)\n", nd_opt->nd_opt_type)); 187 else 188 ndopts->nd_opts_src_lladdr = nd_opt; 189 break; 190 case ND_OPT_TARGET_LINKADDR: 191 if (ndopts->nd_opts_tgt_lladdr != NULL) 192 nd6log((LOG_INFO, "duplicated ND6 option found " 193 "(type=%d)\n", nd_opt->nd_opt_type)); 194 else 195 ndopts->nd_opts_tgt_lladdr = nd_opt; 196 break; 197 case ND_OPT_MTU: 198 case ND_OPT_REDIRECTED_HEADER: 199 case ND_OPT_PREFIX_INFORMATION: 200 case ND_OPT_DNSSL: 201 case ND_OPT_RDNSS: 202 /* Don't warn, not used by kernel */ 203 break; 204 default: 205 /* 206 * Unknown options must be silently ignored, 207 * to accommodate future extension to the protocol. 208 */ 209 nd6log((LOG_DEBUG, 210 "nd6_options: unsupported option %d - " 211 "option ignored\n", nd_opt->nd_opt_type)); 212 break; 213 } 214 215 i++; 216 if (i > nd6_maxndopt) { 217 icmp6stat_inc(icp6s_nd_toomanyopt); 218 nd6log((LOG_INFO, "too many loop in nd opt\n")); 219 break; 220 } 221 } 222 223 return 0; 224 225 invalid: 226 bzero(ndopts, sizeof(*ndopts)); 227 icmp6stat_inc(icp6s_nd_badopt); 228 return -1; 229 } 230 231 /* 232 * ND6 timer routine to handle ND6 entries 233 */ 234 void 235 nd6_llinfo_settimer(const struct llinfo_nd6 *ln, unsigned int secs) 236 { 237 time_t expire = getuptime() + secs; 238 239 NET_ASSERT_LOCKED(); 240 KASSERT(!ISSET(ln->ln_rt->rt_flags, RTF_LOCAL)); 241 242 ln->ln_rt->rt_expire = expire; 243 if (!timeout_pending(&nd6_timer_to) || expire < nd6_timer_next) { 244 nd6_timer_next = expire; 245 timeout_add_sec(&nd6_timer_to, secs); 246 } 247 } 248 249 void 250 nd6_timer(void *unused) 251 { 252 struct llinfo_nd6 *ln, *nln; 253 time_t expire = getuptime() + nd6_gctimer; 254 int secs; 255 256 NET_LOCK(); 257 TAILQ_FOREACH_SAFE(ln, &nd6_list, ln_list, nln) { 258 struct rtentry *rt = ln->ln_rt; 259 260 if (rt->rt_expire && rt->rt_expire <= getuptime()) 261 if (nd6_llinfo_timer(rt)) 262 continue; 263 264 if (rt->rt_expire && rt->rt_expire < expire) 265 expire = rt->rt_expire; 266 } 267 268 secs = expire - getuptime(); 269 if (secs < 0) 270 secs = 0; 271 if (!TAILQ_EMPTY(&nd6_list)) { 272 nd6_timer_next = getuptime() + secs; 273 timeout_add_sec(&nd6_timer_to, secs); 274 } 275 276 NET_UNLOCK(); 277 } 278 279 /* 280 * ND timer state handling. 281 * 282 * Returns 1 if `rt' should no longer be used, 0 otherwise. 283 */ 284 int 285 nd6_llinfo_timer(struct rtentry *rt) 286 { 287 struct llinfo_nd6 *ln = (struct llinfo_nd6 *)rt->rt_llinfo; 288 struct sockaddr_in6 *dst = satosin6(rt_key(rt)); 289 struct ifnet *ifp; 290 291 NET_ASSERT_LOCKED(); 292 293 if ((ifp = if_get(rt->rt_ifidx)) == NULL) 294 return 1; 295 296 switch (ln->ln_state) { 297 case ND6_LLINFO_INCOMPLETE: 298 if (ln->ln_asked < nd6_mmaxtries) { 299 ln->ln_asked++; 300 nd6_llinfo_settimer(ln, RETRANS_TIMER / 1000); 301 nd6_ns_output(ifp, NULL, &dst->sin6_addr, ln, 0); 302 } else { 303 struct mbuf *m = ln->ln_hold; 304 if (m) { 305 ln->ln_hold = NULL; 306 /* 307 * Fake rcvif to make the ICMP error 308 * more helpful in diagnosing for the 309 * receiver. 310 * XXX: should we consider 311 * older rcvif? 312 */ 313 m->m_pkthdr.ph_ifidx = rt->rt_ifidx; 314 315 icmp6_error(m, ICMP6_DST_UNREACH, 316 ICMP6_DST_UNREACH_ADDR, 0); 317 if (ln->ln_hold == m) { 318 /* m is back in ln_hold. Discard. */ 319 m_freem(ln->ln_hold); 320 ln->ln_hold = NULL; 321 } 322 } 323 nd6_free(rt); 324 ln = NULL; 325 } 326 break; 327 case ND6_LLINFO_REACHABLE: 328 if (!ND6_LLINFO_PERMANENT(ln)) { 329 ln->ln_state = ND6_LLINFO_STALE; 330 nd6_llinfo_settimer(ln, nd6_gctimer); 331 } 332 break; 333 334 case ND6_LLINFO_STALE: 335 case ND6_LLINFO_PURGE: 336 /* Garbage Collection(RFC 2461 5.3) */ 337 if (!ND6_LLINFO_PERMANENT(ln)) { 338 nd6_free(rt); 339 ln = NULL; 340 } 341 break; 342 343 case ND6_LLINFO_DELAY: 344 /* We need NUD */ 345 ln->ln_asked = 1; 346 ln->ln_state = ND6_LLINFO_PROBE; 347 nd6_llinfo_settimer(ln, RETRANS_TIMER / 1000); 348 nd6_ns_output(ifp, &dst->sin6_addr, &dst->sin6_addr, ln, 0); 349 break; 350 case ND6_LLINFO_PROBE: 351 if (ln->ln_asked < nd6_umaxtries) { 352 ln->ln_asked++; 353 nd6_llinfo_settimer(ln, RETRANS_TIMER / 1000); 354 nd6_ns_output(ifp, &dst->sin6_addr, 355 &dst->sin6_addr, ln, 0); 356 } else { 357 nd6_free(rt); 358 ln = NULL; 359 } 360 break; 361 } 362 363 if_put(ifp); 364 365 return (ln == NULL); 366 } 367 368 void 369 nd6_expire_timer_update(struct in6_ifaddr *ia6) 370 { 371 time_t expire_time = INT64_MAX; 372 int secs; 373 374 if (ia6->ia6_lifetime.ia6t_vltime != ND6_INFINITE_LIFETIME) 375 expire_time = ia6->ia6_lifetime.ia6t_expire; 376 377 if (!(ia6->ia6_flags & IN6_IFF_DEPRECATED) && 378 ia6->ia6_lifetime.ia6t_pltime != ND6_INFINITE_LIFETIME && 379 expire_time > ia6->ia6_lifetime.ia6t_preferred) 380 expire_time = ia6->ia6_lifetime.ia6t_preferred; 381 382 if (expire_time == INT64_MAX) 383 return; 384 385 /* 386 * IFA6_IS_INVALID() and IFA6_IS_DEPRECATED() check for uptime 387 * greater than ia6t_expire or ia6t_preferred, not greater or equal. 388 * Schedule timeout one second later so that either IFA6_IS_INVALID() 389 * or IFA6_IS_DEPRECATED() is true. 390 */ 391 expire_time++; 392 393 if (!timeout_pending(&nd6_expire_timeout) || 394 nd6_expire_next > expire_time) { 395 secs = expire_time - getuptime(); 396 if (secs < 0) 397 secs = 0; 398 399 timeout_add_sec(&nd6_expire_timeout, secs); 400 nd6_expire_next = expire_time; 401 } 402 } 403 404 /* 405 * Expire interface addresses. 406 */ 407 void 408 nd6_expire(void *unused) 409 { 410 struct ifnet *ifp; 411 412 NET_LOCK(); 413 414 TAILQ_FOREACH(ifp, &ifnetlist, if_list) { 415 struct ifaddr *ifa, *nifa; 416 struct in6_ifaddr *ia6; 417 418 TAILQ_FOREACH_SAFE(ifa, &ifp->if_addrlist, ifa_list, nifa) { 419 if (ifa->ifa_addr->sa_family != AF_INET6) 420 continue; 421 ia6 = ifatoia6(ifa); 422 /* check address lifetime */ 423 if (IFA6_IS_INVALID(ia6)) { 424 in6_purgeaddr(&ia6->ia_ifa); 425 } else { 426 if (IFA6_IS_DEPRECATED(ia6)) 427 ia6->ia6_flags |= IN6_IFF_DEPRECATED; 428 nd6_expire_timer_update(ia6); 429 } 430 } 431 } 432 433 NET_UNLOCK(); 434 } 435 436 void 437 nd6_expire_timer(void *unused) 438 { 439 task_add(net_tq(0), &nd6_expire_task); 440 } 441 442 /* 443 * Nuke neighbor cache/prefix/default router management table, right before 444 * ifp goes away. 445 */ 446 void 447 nd6_purge(struct ifnet *ifp) 448 { 449 struct llinfo_nd6 *ln, *nln; 450 451 NET_ASSERT_LOCKED(); 452 453 /* 454 * Nuke neighbor cache entries for the ifp. 455 */ 456 TAILQ_FOREACH_SAFE(ln, &nd6_list, ln_list, nln) { 457 struct rtentry *rt; 458 struct sockaddr_dl *sdl; 459 460 rt = ln->ln_rt; 461 if (rt != NULL && rt->rt_gateway != NULL && 462 rt->rt_gateway->sa_family == AF_LINK) { 463 sdl = satosdl(rt->rt_gateway); 464 if (sdl->sdl_index == ifp->if_index) 465 nd6_free(rt); 466 } 467 } 468 } 469 470 struct rtentry * 471 nd6_lookup(const struct in6_addr *addr6, int create, struct ifnet *ifp, 472 u_int rtableid) 473 { 474 struct rtentry *rt; 475 struct sockaddr_in6 sin6; 476 int flags; 477 478 bzero(&sin6, sizeof(sin6)); 479 sin6.sin6_len = sizeof(struct sockaddr_in6); 480 sin6.sin6_family = AF_INET6; 481 sin6.sin6_addr = *addr6; 482 flags = (create) ? RT_RESOLVE : 0; 483 484 rt = rtalloc(sin6tosa(&sin6), flags, rtableid); 485 if (rt != NULL && (rt->rt_flags & RTF_LLINFO) == 0) { 486 /* 487 * This is the case for the default route. 488 * If we want to create a neighbor cache for the address, we 489 * should free the route for the destination and allocate an 490 * interface route. 491 */ 492 if (create) { 493 rtfree(rt); 494 rt = NULL; 495 } 496 } 497 if (rt == NULL) { 498 if (create && ifp) { 499 struct rt_addrinfo info; 500 struct ifaddr *ifa; 501 int error; 502 503 /* 504 * If no route is available and create is set, 505 * we allocate a host route for the destination 506 * and treat it like an interface route. 507 * This hack is necessary for a neighbor which can't 508 * be covered by our own prefix. 509 */ 510 ifa = ifaof_ifpforaddr(sin6tosa(&sin6), ifp); 511 if (ifa == NULL) 512 return (NULL); 513 514 /* 515 * Create a new route. RTF_LLINFO is necessary 516 * to create a Neighbor Cache entry for the 517 * destination in nd6_rtrequest which will be 518 * called in rtrequest. 519 */ 520 bzero(&info, sizeof(info)); 521 info.rti_ifa = ifa; 522 info.rti_flags = RTF_HOST | RTF_LLINFO; 523 info.rti_info[RTAX_DST] = sin6tosa(&sin6); 524 info.rti_info[RTAX_GATEWAY] = sdltosa(ifp->if_sadl); 525 error = rtrequest(RTM_ADD, &info, RTP_CONNECTED, &rt, 526 rtableid); 527 if (error) 528 return (NULL); 529 if (rt->rt_llinfo != NULL) { 530 struct llinfo_nd6 *ln = 531 (struct llinfo_nd6 *)rt->rt_llinfo; 532 ln->ln_state = ND6_LLINFO_NOSTATE; 533 } 534 } else 535 return (NULL); 536 } 537 /* 538 * Validation for the entry. 539 * Note that the check for rt_llinfo is necessary because a cloned 540 * route from a parent route that has the L flag (e.g. the default 541 * route to a p2p interface) may have the flag, too, while the 542 * destination is not actually a neighbor. 543 */ 544 if ((rt->rt_flags & RTF_GATEWAY) || (rt->rt_flags & RTF_LLINFO) == 0 || 545 rt->rt_gateway->sa_family != AF_LINK || rt->rt_llinfo == NULL || 546 (ifp != NULL && rt->rt_ifidx != ifp->if_index)) { 547 if (create) { 548 char addr[INET6_ADDRSTRLEN]; 549 nd6log((LOG_DEBUG, "%s: failed to lookup %s (if=%s)\n", 550 __func__, 551 inet_ntop(AF_INET6, addr6, addr, sizeof(addr)), 552 ifp ? ifp->if_xname : "unspec")); 553 } 554 rtfree(rt); 555 return (NULL); 556 } 557 return (rt); 558 } 559 560 /* 561 * Detect if a given IPv6 address identifies a neighbor on a given link. 562 * XXX: should take care of the destination of a p2p link? 563 */ 564 int 565 nd6_is_addr_neighbor(const struct sockaddr_in6 *addr, struct ifnet *ifp) 566 { 567 struct in6_ifaddr *ia6; 568 struct ifaddr *ifa; 569 struct rtentry *rt; 570 571 /* 572 * A link-local address is always a neighbor. 573 * XXX: we should use the sin6_scope_id field rather than the embedded 574 * interface index. 575 * XXX: a link does not necessarily specify a single interface. 576 */ 577 if (IN6_IS_ADDR_LINKLOCAL(&addr->sin6_addr) && 578 ntohs(*(u_int16_t *)&addr->sin6_addr.s6_addr[2]) == ifp->if_index) 579 return (1); 580 581 TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) { 582 if (ifa->ifa_addr->sa_family != AF_INET6) 583 continue; 584 585 ia6 = ifatoia6(ifa); 586 587 /* Prefix check down below. */ 588 if (ia6->ia6_flags & IN6_IFF_AUTOCONF) 589 continue; 590 591 if (IN6_ARE_MASKED_ADDR_EQUAL(&addr->sin6_addr, 592 &ia6->ia_addr.sin6_addr, 593 &ia6->ia_prefixmask.sin6_addr)) 594 return (1); 595 } 596 597 /* 598 * Even if the address matches none of our addresses, it might be 599 * in the neighbor cache. 600 */ 601 rt = nd6_lookup(&addr->sin6_addr, 0, ifp, ifp->if_rdomain); 602 if (rt != NULL) { 603 rtfree(rt); 604 return (1); 605 } 606 607 return (0); 608 } 609 610 void 611 nd6_invalidate(struct rtentry *rt) 612 { 613 struct llinfo_nd6 *ln = (struct llinfo_nd6 *)rt->rt_llinfo; 614 struct sockaddr_dl *sdl = satosdl(rt->rt_gateway); 615 616 m_freem(ln->ln_hold); 617 sdl->sdl_alen = 0; 618 ln->ln_hold = NULL; 619 ln->ln_state = ND6_LLINFO_INCOMPLETE; 620 ln->ln_asked = 0; 621 } 622 623 /* 624 * Free an nd6 llinfo entry. 625 */ 626 void 627 nd6_free(struct rtentry *rt) 628 { 629 struct llinfo_nd6 *ln = (struct llinfo_nd6 *)rt->rt_llinfo; 630 struct in6_addr in6 = satosin6(rt_key(rt))->sin6_addr; 631 struct ifnet *ifp; 632 633 NET_ASSERT_LOCKED(); 634 635 ifp = if_get(rt->rt_ifidx); 636 637 if (!ip6_forwarding) { 638 if (ln->ln_router) { 639 /* 640 * rt6_flush must be called whether or not the neighbor 641 * is in the Default Router List. 642 * See a corresponding comment in nd6_na_input(). 643 */ 644 rt6_flush(&in6, ifp); 645 } 646 } 647 648 KASSERT(!ISSET(rt->rt_flags, RTF_LOCAL)); 649 nd6_invalidate(rt); 650 651 /* 652 * Detach the route from the routing tree and the list of neighbor 653 * caches, and disable the route entry not to be used in already 654 * cached routes. 655 */ 656 if (!ISSET(rt->rt_flags, RTF_STATIC|RTF_CACHED)) 657 rtdeletemsg(rt, ifp, ifp->if_rdomain); 658 659 if_put(ifp); 660 } 661 662 /* 663 * Upper-layer reachability hint for Neighbor Unreachability Detection. 664 * 665 * XXX cost-effective methods? 666 */ 667 void 668 nd6_nud_hint(struct rtentry *rt) 669 { 670 struct llinfo_nd6 *ln; 671 struct ifnet *ifp; 672 673 ifp = if_get(rt->rt_ifidx); 674 if (ifp == NULL) 675 return; 676 677 if ((rt->rt_flags & RTF_GATEWAY) != 0 || 678 (rt->rt_flags & RTF_LLINFO) == 0 || 679 rt->rt_llinfo == NULL || rt->rt_gateway == NULL || 680 rt->rt_gateway->sa_family != AF_LINK) { 681 /* This is not a host route. */ 682 goto out; 683 } 684 685 ln = (struct llinfo_nd6 *)rt->rt_llinfo; 686 if (ln->ln_state < ND6_LLINFO_REACHABLE) 687 goto out; 688 689 /* 690 * if we get upper-layer reachability confirmation many times, 691 * it is possible we have false information. 692 */ 693 ln->ln_byhint++; 694 if (ln->ln_byhint > nd6_maxnudhint) 695 goto out; 696 697 ln->ln_state = ND6_LLINFO_REACHABLE; 698 if (!ND6_LLINFO_PERMANENT(ln)) 699 nd6_llinfo_settimer(ln, ifp->if_nd->reachable); 700 out: 701 if_put(ifp); 702 } 703 704 void 705 nd6_rtrequest(struct ifnet *ifp, int req, struct rtentry *rt) 706 { 707 struct sockaddr *gate = rt->rt_gateway; 708 struct llinfo_nd6 *ln = (struct llinfo_nd6 *)rt->rt_llinfo; 709 struct ifaddr *ifa; 710 struct in6_ifaddr *ifa6; 711 712 if (ISSET(rt->rt_flags, RTF_GATEWAY|RTF_MULTICAST|RTF_MPLS)) 713 return; 714 715 if (nd6_need_cache(ifp) == 0 && (rt->rt_flags & RTF_HOST) == 0) { 716 /* 717 * This is probably an interface direct route for a link 718 * which does not need neighbor caches (e.g. fe80::%lo0/64). 719 * We do not need special treatment below for such a route. 720 * Moreover, the RTF_LLINFO flag which would be set below 721 * would annoy the ndp(8) command. 722 */ 723 return; 724 } 725 726 if (req == RTM_RESOLVE && nd6_need_cache(ifp) == 0) { 727 /* 728 * For routing daemons like ospf6d we allow neighbor discovery 729 * based on the cloning route only. This allows us to send 730 * packets directly into a network without having an address 731 * with matching prefix on the interface. If the cloning 732 * route is used for an 6to4 interface, we would mistakenly 733 * make a neighbor cache for the host route, and would see 734 * strange neighbor solicitation for the corresponding 735 * destination. In order to avoid confusion, we check if the 736 * interface is suitable for neighbor discovery, and stop the 737 * process if not. Additionally, we remove the LLINFO flag 738 * so that ndp(8) will not try to get the neighbor information 739 * of the destination. 740 */ 741 rt->rt_flags &= ~RTF_LLINFO; 742 return; 743 } 744 745 switch (req) { 746 case RTM_ADD: 747 if ((rt->rt_flags & RTF_CLONING) || 748 ((rt->rt_flags & (RTF_LLINFO | RTF_LOCAL)) && ln == NULL)) { 749 if (ln != NULL) 750 nd6_llinfo_settimer(ln, 0); 751 if ((rt->rt_flags & RTF_CLONING) != 0) 752 break; 753 } 754 /* 755 * In IPv4 code, we try to announce new RTF_ANNOUNCE entry here. 756 * We don't do that here since llinfo is not ready yet. 757 * 758 * There are also couple of other things to be discussed: 759 * - unsolicited NA code needs improvement beforehand 760 * - RFC2461 says we MAY send multicast unsolicited NA 761 * (7.2.6 paragraph 4), however, it also says that we 762 * SHOULD provide a mechanism to prevent multicast NA storm. 763 * we don't have anything like it right now. 764 * note that the mechanism needs a mutual agreement 765 * between proxies, which means that we need to implement 766 * a new protocol, or a new kludge. 767 * - from RFC2461 6.2.4, host MUST NOT send an unsolicited NA. 768 * we need to check ip6forwarding before sending it. 769 * (or should we allow proxy ND configuration only for 770 * routers? there's no mention about proxy ND from hosts) 771 */ 772 #if 0 773 /* XXX it does not work */ 774 if (rt->rt_flags & RTF_ANNOUNCE) 775 nd6_na_output(ifp, 776 &satosin6(rt_key(rt))->sin6_addr, 777 &satosin6(rt_key(rt))->sin6_addr, 778 ip6_forwarding ? ND_NA_FLAG_ROUTER : 0, 779 1, NULL); 780 #endif 781 /* FALLTHROUGH */ 782 case RTM_RESOLVE: 783 if (gate->sa_family != AF_LINK || 784 gate->sa_len < sizeof(struct sockaddr_dl)) { 785 log(LOG_DEBUG, "%s: bad gateway value: %s\n", 786 __func__, ifp->if_xname); 787 break; 788 } 789 satosdl(gate)->sdl_type = ifp->if_type; 790 satosdl(gate)->sdl_index = ifp->if_index; 791 if (ln != NULL) 792 break; /* This happens on a route change */ 793 /* 794 * Case 2: This route may come from cloning, or a manual route 795 * add with a LL address. 796 */ 797 ln = pool_get(&nd6_pool, PR_NOWAIT | PR_ZERO); 798 rt->rt_llinfo = (caddr_t)ln; 799 if (ln == NULL) { 800 log(LOG_DEBUG, "%s: pool get failed\n", __func__); 801 break; 802 } 803 nd6_inuse++; 804 ln->ln_rt = rt; 805 /* this is required for "ndp" command. - shin */ 806 if (req == RTM_ADD) { 807 /* 808 * gate should have some valid AF_LINK entry, 809 * and ln expire should have some lifetime 810 * which is specified by ndp command. 811 */ 812 ln->ln_state = ND6_LLINFO_REACHABLE; 813 ln->ln_byhint = 0; 814 } else { 815 /* 816 * When req == RTM_RESOLVE, rt is created and 817 * initialized in rtrequest(), so rt_expire is 0. 818 */ 819 ln->ln_state = ND6_LLINFO_NOSTATE; 820 nd6_llinfo_settimer(ln, 0); 821 } 822 rt->rt_flags |= RTF_LLINFO; 823 TAILQ_INSERT_HEAD(&nd6_list, ln, ln_list); 824 825 /* 826 * If we have too many cache entries, initiate immediate 827 * purging for some "less recently used" entries. Note that 828 * we cannot directly call nd6_free() here because it would 829 * cause re-entering rtable related routines triggering 830 * lock-order-reversal problems. 831 */ 832 if (ip6_neighborgcthresh >= 0 && 833 nd6_inuse >= ip6_neighborgcthresh) { 834 int i; 835 836 for (i = 0; i < 10; i++) { 837 struct llinfo_nd6 *ln_end; 838 839 ln_end = TAILQ_LAST(&nd6_list, llinfo_nd6_head); 840 if (ln_end == ln) 841 break; 842 843 /* Move this entry to the head */ 844 TAILQ_REMOVE(&nd6_list, ln_end, ln_list); 845 TAILQ_INSERT_HEAD(&nd6_list, ln_end, ln_list); 846 847 if (ND6_LLINFO_PERMANENT(ln_end)) 848 continue; 849 850 if (ln_end->ln_state > ND6_LLINFO_INCOMPLETE) 851 ln_end->ln_state = ND6_LLINFO_STALE; 852 else 853 ln_end->ln_state = ND6_LLINFO_PURGE; 854 nd6_llinfo_settimer(ln_end, 0); 855 } 856 } 857 858 /* 859 * check if rt_key(rt) is one of my address assigned 860 * to the interface. 861 */ 862 ifa6 = in6ifa_ifpwithaddr(ifp, 863 &satosin6(rt_key(rt))->sin6_addr); 864 ifa = ifa6 ? &ifa6->ia_ifa : NULL; 865 if (ifa) { 866 ln->ln_state = ND6_LLINFO_REACHABLE; 867 ln->ln_byhint = 0; 868 rt->rt_expire = 0; 869 KASSERT(ifa == rt->rt_ifa); 870 } else if (rt->rt_flags & RTF_ANNOUNCE) { 871 ln->ln_state = ND6_LLINFO_REACHABLE; 872 ln->ln_byhint = 0; 873 rt->rt_expire = 0; 874 875 /* join solicited node multicast for proxy ND */ 876 if (ifp->if_flags & IFF_MULTICAST) { 877 struct in6_addr llsol; 878 int error; 879 880 llsol = satosin6(rt_key(rt))->sin6_addr; 881 llsol.s6_addr16[0] = htons(0xff02); 882 llsol.s6_addr16[1] = htons(ifp->if_index); 883 llsol.s6_addr32[1] = 0; 884 llsol.s6_addr32[2] = htonl(1); 885 llsol.s6_addr8[12] = 0xff; 886 887 if (in6_addmulti(&llsol, ifp, &error)) { 888 char addr[INET6_ADDRSTRLEN]; 889 nd6log((LOG_ERR, "%s: failed to join " 890 "%s (errno=%d)\n", ifp->if_xname, 891 inet_ntop(AF_INET6, &llsol, 892 addr, sizeof(addr)), 893 error)); 894 } 895 } 896 } 897 break; 898 899 case RTM_DELETE: 900 if (ln == NULL) 901 break; 902 /* leave from solicited node multicast for proxy ND */ 903 if ((rt->rt_flags & RTF_ANNOUNCE) != 0 && 904 (ifp->if_flags & IFF_MULTICAST) != 0) { 905 struct in6_addr llsol; 906 struct in6_multi *in6m; 907 908 llsol = satosin6(rt_key(rt))->sin6_addr; 909 llsol.s6_addr16[0] = htons(0xff02); 910 llsol.s6_addr16[1] = htons(ifp->if_index); 911 llsol.s6_addr32[1] = 0; 912 llsol.s6_addr32[2] = htonl(1); 913 llsol.s6_addr8[12] = 0xff; 914 915 IN6_LOOKUP_MULTI(llsol, ifp, in6m); 916 if (in6m) 917 in6_delmulti(in6m); 918 } 919 nd6_inuse--; 920 TAILQ_REMOVE(&nd6_list, ln, ln_list); 921 rt->rt_expire = 0; 922 rt->rt_llinfo = NULL; 923 rt->rt_flags &= ~RTF_LLINFO; 924 m_freem(ln->ln_hold); 925 pool_put(&nd6_pool, ln); 926 break; 927 928 case RTM_INVALIDATE: 929 if (ln == NULL) 930 break; 931 if (!ISSET(rt->rt_flags, RTF_LOCAL)) 932 nd6_invalidate(rt); 933 break; 934 } 935 } 936 937 int 938 nd6_ioctl(u_long cmd, caddr_t data, struct ifnet *ifp) 939 { 940 struct in6_ndireq *ndi = (struct in6_ndireq *)data; 941 struct in6_nbrinfo *nbi = (struct in6_nbrinfo *)data; 942 struct rtentry *rt; 943 944 switch (cmd) { 945 case SIOCGIFINFO_IN6: 946 NET_LOCK_SHARED(); 947 ndi->ndi = *ifp->if_nd; 948 NET_UNLOCK_SHARED(); 949 return (0); 950 case SIOCGNBRINFO_IN6: 951 { 952 struct llinfo_nd6 *ln; 953 struct in6_addr nb_addr = nbi->addr; /* make local for safety */ 954 time_t expire; 955 956 NET_LOCK_SHARED(); 957 /* 958 * XXX: KAME specific hack for scoped addresses 959 * XXXX: for other scopes than link-local? 960 */ 961 if (IN6_IS_ADDR_LINKLOCAL(&nb_addr) || 962 IN6_IS_ADDR_MC_LINKLOCAL(&nb_addr)) { 963 u_int16_t *idp = (u_int16_t *)&nb_addr.s6_addr[2]; 964 965 if (*idp == 0) 966 *idp = htons(ifp->if_index); 967 } 968 969 rt = nd6_lookup(&nb_addr, 0, ifp, ifp->if_rdomain); 970 if (rt == NULL || 971 (ln = (struct llinfo_nd6 *)rt->rt_llinfo) == NULL) { 972 rtfree(rt); 973 NET_UNLOCK_SHARED(); 974 return (EINVAL); 975 } 976 expire = ln->ln_rt->rt_expire; 977 if (expire != 0) { 978 expire -= getuptime(); 979 expire += gettime(); 980 } 981 982 nbi->state = ln->ln_state; 983 nbi->asked = ln->ln_asked; 984 nbi->isrouter = ln->ln_router; 985 nbi->expire = expire; 986 987 rtfree(rt); 988 NET_UNLOCK_SHARED(); 989 return (0); 990 } 991 } 992 return (0); 993 } 994 995 /* 996 * Create neighbor cache entry and cache link-layer address, 997 * on reception of inbound ND6 packets. (RS/RA/NS/redirect) 998 * 999 * type - ICMP6 type 1000 * code - type dependent information 1001 */ 1002 void 1003 nd6_cache_lladdr(struct ifnet *ifp, const struct in6_addr *from, char *lladdr, 1004 int lladdrlen, int type, int code) 1005 { 1006 struct rtentry *rt = NULL; 1007 struct llinfo_nd6 *ln = NULL; 1008 int is_newentry; 1009 struct sockaddr_dl *sdl = NULL; 1010 int do_update; 1011 int olladdr; 1012 int llchange; 1013 int newstate = 0; 1014 1015 if (!ifp) 1016 panic("%s: ifp == NULL", __func__); 1017 if (!from) 1018 panic("%s: from == NULL", __func__); 1019 1020 /* nothing must be updated for unspecified address */ 1021 if (IN6_IS_ADDR_UNSPECIFIED(from)) 1022 return; 1023 1024 /* 1025 * Validation about ifp->if_addrlen and lladdrlen must be done in 1026 * the caller. 1027 * 1028 * XXX If the link does not have link-layer address, what should 1029 * we do? (ifp->if_addrlen == 0) 1030 * Spec says nothing in sections for RA, RS and NA. There's small 1031 * description on it in NS section (RFC 2461 7.2.3). 1032 */ 1033 1034 rt = nd6_lookup(from, 0, ifp, ifp->if_rdomain); 1035 if (rt == NULL) { 1036 rt = nd6_lookup(from, 1, ifp, ifp->if_rdomain); 1037 is_newentry = 1; 1038 } else { 1039 /* do not overwrite local or static entry */ 1040 if (ISSET(rt->rt_flags, RTF_STATIC|RTF_LOCAL)) { 1041 rtfree(rt); 1042 return; 1043 } 1044 is_newentry = 0; 1045 } 1046 1047 if (!rt) 1048 return; 1049 if ((rt->rt_flags & (RTF_GATEWAY | RTF_LLINFO)) != RTF_LLINFO) { 1050 fail: 1051 nd6_free(rt); 1052 rtfree(rt); 1053 return; 1054 } 1055 ln = (struct llinfo_nd6 *)rt->rt_llinfo; 1056 if (ln == NULL) 1057 goto fail; 1058 if (rt->rt_gateway == NULL) 1059 goto fail; 1060 if (rt->rt_gateway->sa_family != AF_LINK) 1061 goto fail; 1062 sdl = satosdl(rt->rt_gateway); 1063 1064 olladdr = (sdl->sdl_alen) ? 1 : 0; 1065 if (olladdr && lladdr) { 1066 if (bcmp(lladdr, LLADDR(sdl), ifp->if_addrlen)) 1067 llchange = 1; 1068 else 1069 llchange = 0; 1070 } else 1071 llchange = 0; 1072 1073 /* 1074 * newentry olladdr lladdr llchange (*=record) 1075 * 0 n n -- (1) 1076 * 0 y n -- (2) 1077 * 0 n y -- (3) * STALE 1078 * 0 y y n (4) * 1079 * 0 y y y (5) * STALE 1080 * 1 -- n -- (6) NOSTATE(= PASSIVE) 1081 * 1 -- y -- (7) * STALE 1082 */ 1083 1084 if (llchange) { 1085 char addr[INET6_ADDRSTRLEN]; 1086 log(LOG_INFO, "ndp info overwritten for %s by %s on %s\n", 1087 inet_ntop(AF_INET6, from, addr, sizeof(addr)), 1088 ether_sprintf(lladdr), ifp->if_xname); 1089 } 1090 if (lladdr) { /* (3-5) and (7) */ 1091 /* 1092 * Record source link-layer address 1093 * XXX is it dependent to ifp->if_type? 1094 */ 1095 sdl->sdl_alen = ifp->if_addrlen; 1096 bcopy(lladdr, LLADDR(sdl), ifp->if_addrlen); 1097 } 1098 1099 if (!is_newentry) { 1100 if ((!olladdr && lladdr) || /* (3) */ 1101 (olladdr && lladdr && llchange)) { /* (5) */ 1102 do_update = 1; 1103 newstate = ND6_LLINFO_STALE; 1104 } else /* (1-2,4) */ 1105 do_update = 0; 1106 } else { 1107 do_update = 1; 1108 if (!lladdr) /* (6) */ 1109 newstate = ND6_LLINFO_NOSTATE; 1110 else /* (7) */ 1111 newstate = ND6_LLINFO_STALE; 1112 } 1113 1114 if (do_update) { 1115 /* 1116 * Update the state of the neighbor cache. 1117 */ 1118 ln->ln_state = newstate; 1119 1120 if (ln->ln_state == ND6_LLINFO_STALE) { 1121 /* 1122 * Since nd6_resolve() in ifp->if_output() will cause 1123 * state transition to DELAY and reset the timer, 1124 * we must set the timer now, although it is actually 1125 * meaningless. 1126 */ 1127 nd6_llinfo_settimer(ln, nd6_gctimer); 1128 1129 if (ln->ln_hold) { 1130 struct mbuf *n = ln->ln_hold; 1131 ln->ln_hold = NULL; 1132 /* 1133 * we assume ifp is not a p2p here, so just 1134 * set the 2nd argument as the 1st one. 1135 */ 1136 ifp->if_output(ifp, n, rt_key(rt), rt); 1137 if (ln->ln_hold == n) { 1138 /* n is back in ln_hold. Discard. */ 1139 m_freem(ln->ln_hold); 1140 ln->ln_hold = NULL; 1141 } 1142 } 1143 } else if (ln->ln_state == ND6_LLINFO_INCOMPLETE) { 1144 /* probe right away */ 1145 nd6_llinfo_settimer(ln, 0); 1146 } 1147 } 1148 1149 /* 1150 * ICMP6 type dependent behavior. 1151 * 1152 * NS: clear IsRouter if new entry 1153 * RS: clear IsRouter 1154 * RA: set IsRouter if there's lladdr 1155 * redir: clear IsRouter if new entry 1156 * 1157 * RA case, (1): 1158 * The spec says that we must set IsRouter in the following cases: 1159 * - If lladdr exist, set IsRouter. This means (1-5). 1160 * - If it is old entry (!newentry), set IsRouter. This means (7). 1161 * So, based on the spec, in (1-5) and (7) cases we must set IsRouter. 1162 * A question arises for (1) case. (1) case has no lladdr in the 1163 * neighbor cache, this is similar to (6). 1164 * This case is rare but we figured that we MUST NOT set IsRouter. 1165 * 1166 * newentry olladdr lladdr llchange NS RS RA redir 1167 * D R 1168 * 0 n n -- (1) c ? s 1169 * 0 y n -- (2) c s s 1170 * 0 n y -- (3) c s s 1171 * 0 y y n (4) c s s 1172 * 0 y y y (5) c s s 1173 * 1 -- n -- (6) c c c s 1174 * 1 -- y -- (7) c c s c s 1175 * 1176 * (c=clear s=set) 1177 */ 1178 switch (type & 0xff) { 1179 case ND_NEIGHBOR_SOLICIT: 1180 /* 1181 * New entry must have is_router flag cleared. 1182 */ 1183 if (is_newentry) /* (6-7) */ 1184 ln->ln_router = 0; 1185 break; 1186 case ND_REDIRECT: 1187 /* 1188 * If the icmp is a redirect to a better router, always set the 1189 * is_router flag. Otherwise, if the entry is newly created, 1190 * clear the flag. [RFC 2461, sec 8.3] 1191 */ 1192 if (code == ND_REDIRECT_ROUTER) 1193 ln->ln_router = 1; 1194 else if (is_newentry) /* (6-7) */ 1195 ln->ln_router = 0; 1196 break; 1197 case ND_ROUTER_SOLICIT: 1198 /* 1199 * is_router flag must always be cleared. 1200 */ 1201 ln->ln_router = 0; 1202 break; 1203 case ND_ROUTER_ADVERT: 1204 /* 1205 * Mark an entry with lladdr as a router. 1206 */ 1207 if ((!is_newentry && (olladdr || lladdr)) || /* (2-5) */ 1208 (is_newentry && lladdr)) { /* (7) */ 1209 ln->ln_router = 1; 1210 } 1211 break; 1212 } 1213 1214 rtfree(rt); 1215 } 1216 1217 void 1218 nd6_slowtimo(void *ignored_arg) 1219 { 1220 struct nd_ifinfo *nd6if; 1221 struct ifnet *ifp; 1222 1223 NET_LOCK(); 1224 1225 timeout_add_sec(&nd6_slowtimo_ch, ND6_SLOWTIMER_INTERVAL); 1226 1227 TAILQ_FOREACH(ifp, &ifnetlist, if_list) { 1228 nd6if = ifp->if_nd; 1229 if ((nd6if->recalctm -= ND6_SLOWTIMER_INTERVAL) <= 0) { 1230 /* 1231 * Since reachable time rarely changes by router 1232 * advertisements, we SHOULD insure that a new random 1233 * value gets recomputed at least once every few hours. 1234 * (RFC 2461, 6.3.4) 1235 */ 1236 nd6if->recalctm = ND6_RECALC_REACHTM_INTERVAL; 1237 nd6if->reachable = ND_COMPUTE_RTIME(REACHABLE_TIME); 1238 } 1239 } 1240 NET_UNLOCK(); 1241 } 1242 1243 int 1244 nd6_resolve(struct ifnet *ifp, struct rtentry *rt0, struct mbuf *m, 1245 struct sockaddr *dst, u_char *desten) 1246 { 1247 struct sockaddr_dl *sdl; 1248 struct rtentry *rt; 1249 struct llinfo_nd6 *ln = NULL; 1250 1251 if (m->m_flags & M_MCAST) { 1252 ETHER_MAP_IPV6_MULTICAST(&satosin6(dst)->sin6_addr, desten); 1253 return (0); 1254 } 1255 1256 rt = rt_getll(rt0); 1257 1258 if (ISSET(rt->rt_flags, RTF_REJECT) && 1259 (rt->rt_expire == 0 || getuptime() < rt->rt_expire)) { 1260 m_freem(m); 1261 return (rt == rt0 ? EHOSTDOWN : EHOSTUNREACH); 1262 } 1263 1264 /* 1265 * Address resolution or Neighbor Unreachability Detection 1266 * for the next hop. 1267 * At this point, the destination of the packet must be a unicast 1268 * or an anycast address(i.e. not a multicast). 1269 */ 1270 if (!ISSET(rt->rt_flags, RTF_LLINFO)) { 1271 char addr[INET6_ADDRSTRLEN]; 1272 log(LOG_DEBUG, "%s: %s: route contains no ND information\n", 1273 __func__, inet_ntop(AF_INET6, 1274 &satosin6(rt_key(rt))->sin6_addr, addr, sizeof(addr))); 1275 m_freem(m); 1276 return (EINVAL); 1277 } 1278 1279 if (rt->rt_gateway->sa_family != AF_LINK) { 1280 printf("%s: something odd happens\n", __func__); 1281 m_freem(m); 1282 return (EINVAL); 1283 } 1284 1285 ln = (struct llinfo_nd6 *)rt->rt_llinfo; 1286 KASSERT(ln != NULL); 1287 1288 /* 1289 * Move this entry to the head of the queue so that it is less likely 1290 * for this entry to be a target of forced garbage collection (see 1291 * nd6_rtrequest()). 1292 */ 1293 TAILQ_REMOVE(&nd6_list, ln, ln_list); 1294 TAILQ_INSERT_HEAD(&nd6_list, ln, ln_list); 1295 1296 /* 1297 * The first time we send a packet to a neighbor whose entry is 1298 * STALE, we have to change the state to DELAY and set a timer to 1299 * expire in DELAY_FIRST_PROBE_TIME seconds to ensure we do 1300 * neighbor unreachability detection on expiration. 1301 * (RFC 2461 7.3.3) 1302 */ 1303 if (ln->ln_state == ND6_LLINFO_STALE) { 1304 ln->ln_asked = 0; 1305 ln->ln_state = ND6_LLINFO_DELAY; 1306 nd6_llinfo_settimer(ln, nd6_delay); 1307 } 1308 1309 /* 1310 * If the neighbor cache entry has a state other than INCOMPLETE 1311 * (i.e. its link-layer address is already resolved), just 1312 * send the packet. 1313 */ 1314 if (ln->ln_state > ND6_LLINFO_INCOMPLETE) { 1315 sdl = satosdl(rt->rt_gateway); 1316 if (sdl->sdl_alen != ETHER_ADDR_LEN) { 1317 char addr[INET6_ADDRSTRLEN]; 1318 log(LOG_DEBUG, "%s: %s: incorrect nd6 information\n", 1319 __func__, 1320 inet_ntop(AF_INET6, &satosin6(dst)->sin6_addr, 1321 addr, sizeof(addr))); 1322 m_freem(m); 1323 return (EINVAL); 1324 } 1325 1326 bcopy(LLADDR(sdl), desten, sdl->sdl_alen); 1327 return (0); 1328 } 1329 1330 /* 1331 * There is a neighbor cache entry, but no ethernet address 1332 * response yet. Replace the held mbuf (if any) with this 1333 * latest one. 1334 */ 1335 if (ln->ln_state == ND6_LLINFO_NOSTATE) 1336 ln->ln_state = ND6_LLINFO_INCOMPLETE; 1337 m_freem(ln->ln_hold); 1338 ln->ln_hold = m; 1339 1340 /* 1341 * If there has been no NS for the neighbor after entering the 1342 * INCOMPLETE state, send the first solicitation. 1343 */ 1344 if (!ND6_LLINFO_PERMANENT(ln) && ln->ln_asked == 0) { 1345 ln->ln_asked++; 1346 nd6_llinfo_settimer(ln, RETRANS_TIMER / 1000); 1347 nd6_ns_output(ifp, NULL, &satosin6(dst)->sin6_addr, ln, 0); 1348 } 1349 return (EAGAIN); 1350 } 1351 1352 int 1353 nd6_need_cache(struct ifnet *ifp) 1354 { 1355 /* 1356 * RFC2893 says: 1357 * - unidirectional tunnels needs no ND 1358 */ 1359 switch (ifp->if_type) { 1360 case IFT_ETHER: 1361 case IFT_IEEE80211: 1362 case IFT_CARP: 1363 return (1); 1364 default: 1365 return (0); 1366 } 1367 }
Cache object: 607fb0ed049dd3c3824abfd1ef613491
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