1 /* $NetBSD: nd6.c,v 1.282 2024/04/11 07:34:37 knakahara Exp $ */ 2 /* $KAME: nd6.c,v 1.279 2002/06/08 11:16:51 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/cdefs.h> 34 __KERNEL_RCSID(0, "$NetBSD: nd6.c,v 1.282 2024/04/11 07:34:37 knakahara Exp $"); 35 36 #ifdef _KERNEL_OPT 37 #include "opt_compat_netbsd.h" 38 #include "opt_net_mpsafe.h" 39 #endif 40 41 #include "bridge.h" 42 #include "carp.h" 43 44 #include <sys/param.h> 45 #include <sys/systm.h> 46 #include <sys/callout.h> 47 #include <sys/kmem.h> 48 #include <sys/mbuf.h> 49 #include <sys/socket.h> 50 #include <sys/socketvar.h> 51 #include <sys/sockio.h> 52 #include <sys/time.h> 53 #include <sys/kernel.h> 54 #include <sys/errno.h> 55 #include <sys/ioctl.h> 56 #include <sys/syslog.h> 57 #include <sys/queue.h> 58 #include <sys/cprng.h> 59 #include <sys/workqueue.h> 60 #include <sys/compat_stub.h> 61 62 #include <net/if.h> 63 #include <net/if_dl.h> 64 #include <net/if_llatbl.h> 65 #include <net/if_types.h> 66 #include <net/nd.h> 67 #include <net/route.h> 68 #include <net/if_ether.h> 69 #include <net/if_arc.h> 70 71 #include <netinet/in.h> 72 #include <netinet6/in6_var.h> 73 #include <netinet/ip6.h> 74 #include <netinet6/ip6_var.h> 75 #include <netinet6/scope6_var.h> 76 #include <netinet6/nd6.h> 77 #include <netinet6/in6_ifattach.h> 78 #include <netinet/icmp6.h> 79 #include <netinet6/icmp6_private.h> 80 81 #include <compat/netinet6/in6_var.h> 82 #include <compat/netinet6/nd6.h> 83 84 #define ND6_SLOWTIMER_INTERVAL (60 * 60) /* 1 hour */ 85 #define ND6_RECALC_REACHTM_INTERVAL (60 * 120) /* 2 hours */ 86 87 /* timer values */ 88 int nd6_prune = 1; /* walk list every 1 seconds */ 89 int nd6_useloopback = 1; /* use loopback interface for local traffic */ 90 91 /* preventing too many loops in ND option parsing */ 92 int nd6_maxndopt = 10; /* max # of ND options allowed */ 93 94 #ifdef ND6_DEBUG 95 int nd6_debug = 1; 96 #else 97 int nd6_debug = 0; 98 #endif 99 100 krwlock_t nd6_lock __cacheline_aligned; 101 102 int nd6_recalc_reachtm_interval = ND6_RECALC_REACHTM_INTERVAL; 103 104 static void nd6_slowtimo(void *); 105 static void nd6_free(struct llentry *, int); 106 static bool nd6_nud_enabled(struct ifnet *); 107 static unsigned int nd6_llinfo_reachable(struct ifnet *); 108 static unsigned int nd6_llinfo_retrans(struct ifnet *); 109 static union l3addr *nd6_llinfo_holdsrc(struct llentry *, union l3addr *); 110 static void nd6_llinfo_output(struct ifnet *, const union l3addr *, 111 const union l3addr *, const uint8_t *, const union l3addr *); 112 static void nd6_llinfo_missed(struct ifnet *, const union l3addr *, 113 int16_t, struct mbuf *); 114 static void nd6_timer(void *); 115 static void nd6_timer_work(struct work *, void *); 116 static struct nd_opt_hdr *nd6_option(union nd_opts *); 117 118 static callout_t nd6_slowtimo_ch; 119 static callout_t nd6_timer_ch; 120 static struct workqueue *nd6_timer_wq; 121 static struct work nd6_timer_wk; 122 123 struct nd_domain nd6_nd_domain = { 124 .nd_family = AF_INET6, 125 .nd_delay = 5, /* delay first probe time 5 second */ 126 .nd_mmaxtries = 3, /* maximum unicast query */ 127 .nd_umaxtries = 3, /* maximum multicast query */ 128 .nd_retransmultiple = BACKOFF_MULTIPLE, 129 .nd_maxretrans = MAX_RETRANS_TIMER, 130 .nd_maxnudhint = 0, /* max # of subsequent upper layer hints */ 131 .nd_maxqueuelen = 1, /* max # of packets in unresolved ND entries */ 132 .nd_nud_enabled = nd6_nud_enabled, 133 .nd_reachable = nd6_llinfo_reachable, 134 .nd_retrans = nd6_llinfo_retrans, 135 .nd_holdsrc = nd6_llinfo_holdsrc, 136 .nd_output = nd6_llinfo_output, 137 .nd_missed = nd6_llinfo_missed, 138 .nd_free = nd6_free, 139 }; 140 141 MALLOC_DEFINE(M_IP6NDP, "NDP", "IPv6 Neighbour Discovery"); 142 143 void 144 nd6_init(void) 145 { 146 int error; 147 148 nd_attach_domain(&nd6_nd_domain); 149 nd6_nbr_init(); 150 151 rw_init(&nd6_lock); 152 153 callout_init(&nd6_slowtimo_ch, CALLOUT_MPSAFE); 154 callout_init(&nd6_timer_ch, CALLOUT_MPSAFE); 155 156 error = workqueue_create(&nd6_timer_wq, "nd6_timer", 157 nd6_timer_work, NULL, PRI_SOFTNET, IPL_SOFTNET, WQ_MPSAFE); 158 if (error) 159 panic("%s: workqueue_create failed (%d)\n", __func__, error); 160 161 /* start timer */ 162 callout_reset(&nd6_slowtimo_ch, ND6_SLOWTIMER_INTERVAL * hz, 163 nd6_slowtimo, NULL); 164 callout_reset(&nd6_timer_ch, hz, nd6_timer, NULL); 165 } 166 167 struct nd_kifinfo * 168 nd6_ifattach(struct ifnet *ifp) 169 { 170 struct nd_kifinfo *nd; 171 172 nd = kmem_zalloc(sizeof(*nd), KM_SLEEP); 173 174 nd->chlim = IPV6_DEFHLIM; 175 nd->basereachable = REACHABLE_TIME; 176 nd->reachable = ND_COMPUTE_RTIME(nd->basereachable); 177 nd->retrans = RETRANS_TIMER; 178 179 nd->flags = ND6_IFF_PERFORMNUD; 180 181 /* A loopback interface always has ND6_IFF_AUTO_LINKLOCAL. 182 * A bridge interface should not have ND6_IFF_AUTO_LINKLOCAL 183 * because one of its members should. */ 184 if ((ip6_auto_linklocal && ifp->if_type != IFT_BRIDGE) || 185 (ifp->if_flags & IFF_LOOPBACK)) 186 nd->flags |= ND6_IFF_AUTO_LINKLOCAL; 187 188 return nd; 189 } 190 191 void 192 nd6_ifdetach(struct ifnet *ifp, struct in6_ifextra *ext) 193 { 194 195 /* Ensure all IPv6 addresses are purged before calling nd6_purge */ 196 if_purgeaddrs(ifp, AF_INET6, in6_purgeaddr); 197 nd6_purge(ifp, ext); 198 kmem_free(ext->nd_ifinfo, sizeof(struct nd_kifinfo)); 199 } 200 201 void 202 nd6_option_init(void *opt, int icmp6len, union nd_opts *ndopts) 203 { 204 205 memset(ndopts, 0, sizeof(*ndopts)); 206 ndopts->nd_opts_search = (struct nd_opt_hdr *)opt; 207 ndopts->nd_opts_last 208 = (struct nd_opt_hdr *)(((u_char *)opt) + icmp6len); 209 210 if (icmp6len == 0) { 211 ndopts->nd_opts_done = 1; 212 ndopts->nd_opts_search = NULL; 213 } 214 } 215 216 /* 217 * Take one ND option. 218 */ 219 static struct nd_opt_hdr * 220 nd6_option(union nd_opts *ndopts) 221 { 222 struct nd_opt_hdr *nd_opt; 223 int olen; 224 225 KASSERT(ndopts != NULL); 226 KASSERT(ndopts->nd_opts_last != NULL); 227 228 if (ndopts->nd_opts_search == NULL) 229 return NULL; 230 if (ndopts->nd_opts_done) 231 return NULL; 232 233 nd_opt = ndopts->nd_opts_search; 234 235 /* make sure nd_opt_len is inside the buffer */ 236 if ((void *)&nd_opt->nd_opt_len >= (void *)ndopts->nd_opts_last) { 237 memset(ndopts, 0, sizeof(*ndopts)); 238 return NULL; 239 } 240 241 olen = nd_opt->nd_opt_len << 3; 242 if (olen == 0) { 243 /* 244 * Message validation requires that all included 245 * options have a length that is greater than zero. 246 */ 247 memset(ndopts, 0, sizeof(*ndopts)); 248 return NULL; 249 } 250 251 ndopts->nd_opts_search = (struct nd_opt_hdr *)((char *)nd_opt + olen); 252 if (ndopts->nd_opts_search > ndopts->nd_opts_last) { 253 /* option overruns the end of buffer, invalid */ 254 memset(ndopts, 0, sizeof(*ndopts)); 255 return NULL; 256 } else if (ndopts->nd_opts_search == ndopts->nd_opts_last) { 257 /* reached the end of options chain */ 258 ndopts->nd_opts_done = 1; 259 ndopts->nd_opts_search = NULL; 260 } 261 return nd_opt; 262 } 263 264 /* 265 * Parse multiple ND options. 266 * This function is much easier to use, for ND routines that do not need 267 * multiple options of the same type. 268 */ 269 int 270 nd6_options(union nd_opts *ndopts) 271 { 272 struct nd_opt_hdr *nd_opt; 273 int i = 0; 274 275 KASSERT(ndopts != NULL); 276 KASSERT(ndopts->nd_opts_last != NULL); 277 278 if (ndopts->nd_opts_search == NULL) 279 return 0; 280 281 while (1) { 282 nd_opt = nd6_option(ndopts); 283 if (nd_opt == NULL && ndopts->nd_opts_last == NULL) { 284 /* 285 * Message validation requires that all included 286 * options have a length that is greater than zero. 287 */ 288 ICMP6_STATINC(ICMP6_STAT_ND_BADOPT); 289 memset(ndopts, 0, sizeof(*ndopts)); 290 return -1; 291 } 292 293 if (nd_opt == NULL) 294 goto skip1; 295 296 switch (nd_opt->nd_opt_type) { 297 case ND_OPT_SOURCE_LINKADDR: 298 case ND_OPT_TARGET_LINKADDR: 299 case ND_OPT_MTU: 300 case ND_OPT_REDIRECTED_HEADER: 301 case ND_OPT_NONCE: 302 if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) { 303 nd6log(LOG_INFO, 304 "duplicated ND6 option found (type=%d)\n", 305 nd_opt->nd_opt_type); 306 /* XXX bark? */ 307 } else { 308 ndopts->nd_opt_array[nd_opt->nd_opt_type] 309 = nd_opt; 310 } 311 break; 312 case ND_OPT_PREFIX_INFORMATION: 313 if (ndopts->nd_opt_array[nd_opt->nd_opt_type] == 0) { 314 ndopts->nd_opt_array[nd_opt->nd_opt_type] 315 = nd_opt; 316 } 317 ndopts->nd_opts_pi_end = 318 (struct nd_opt_prefix_info *)nd_opt; 319 break; 320 default: 321 /* 322 * Unknown options must be silently ignored, 323 * to accommodate future extension to the protocol. 324 */ 325 nd6log(LOG_DEBUG, 326 "nd6_options: unsupported option %d - " 327 "option ignored\n", nd_opt->nd_opt_type); 328 } 329 330 skip1: 331 i++; 332 if (i > nd6_maxndopt) { 333 ICMP6_STATINC(ICMP6_STAT_ND_TOOMANYOPT); 334 nd6log(LOG_INFO, "too many loop in nd opt\n"); 335 break; 336 } 337 338 if (ndopts->nd_opts_done) 339 break; 340 } 341 342 return 0; 343 } 344 345 /* 346 * Gets source address of the first packet in hold queue 347 * and stores it in @src. 348 * Returns pointer to @src (if hold queue is not empty) or NULL. 349 */ 350 static struct in6_addr * 351 nd6_llinfo_get_holdsrc(struct llentry *ln, struct in6_addr *src) 352 { 353 struct ip6_hdr *hip6; 354 355 if (ln == NULL || ln->ln_hold == NULL) 356 return NULL; 357 358 /* 359 * assuming every packet in ln_hold has the same IP header 360 */ 361 hip6 = mtod(ln->ln_hold, struct ip6_hdr *); 362 /* XXX pullup? */ 363 if (sizeof(*hip6) < ln->ln_hold->m_len) 364 *src = hip6->ip6_src; 365 else 366 src = NULL; 367 368 return src; 369 } 370 371 static union l3addr * 372 nd6_llinfo_holdsrc(struct llentry *ln, union l3addr *src) 373 { 374 375 if (nd6_llinfo_get_holdsrc(ln, &src->addr6) == NULL) 376 return NULL; 377 return src; 378 } 379 380 static void 381 nd6_llinfo_output(struct ifnet *ifp, const union l3addr *daddr, 382 const union l3addr *taddr, __unused const uint8_t *tlladdr, 383 const union l3addr *hsrc) 384 { 385 386 nd6_ns_output(ifp, 387 daddr != NULL ? &daddr->addr6 : NULL, 388 taddr != NULL ? &taddr->addr6 : NULL, 389 hsrc != NULL ? &hsrc->addr6 : NULL, NULL); 390 } 391 392 static bool 393 nd6_nud_enabled(struct ifnet *ifp) 394 { 395 struct nd_kifinfo *ndi = ND_IFINFO(ifp); 396 397 return ndi->flags & ND6_IFF_PERFORMNUD; 398 } 399 400 static unsigned int 401 nd6_llinfo_reachable(struct ifnet *ifp) 402 { 403 struct nd_kifinfo *ndi = ND_IFINFO(ifp); 404 405 return ndi->reachable; 406 } 407 408 static unsigned int 409 nd6_llinfo_retrans(struct ifnet *ifp) 410 { 411 struct nd_kifinfo *ndi = ND_IFINFO(ifp); 412 413 return ndi->retrans; 414 } 415 416 static void 417 nd6_llinfo_missed(struct ifnet *ifp, const union l3addr *taddr, 418 int16_t type, struct mbuf *m) 419 { 420 struct in6_addr mdaddr6 = zeroin6_addr; 421 struct sockaddr_in6 dsin6, tsin6; 422 struct sockaddr *sa; 423 424 if (m != NULL) { 425 if (type == ND_LLINFO_PROBE) { 426 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 427 428 /* XXX pullup? */ 429 if (sizeof(*ip6) < m->m_len) 430 mdaddr6 = ip6->ip6_src; 431 m_freem(m); 432 } else 433 icmp6_error2(m, ICMP6_DST_UNREACH, 434 ICMP6_DST_UNREACH_ADDR, 0, ifp, &mdaddr6); 435 } 436 if (!IN6_IS_ADDR_UNSPECIFIED(&mdaddr6)) { 437 sockaddr_in6_init(&dsin6, &mdaddr6, 0, 0, 0); 438 sa = sin6tosa(&dsin6); 439 } else 440 sa = NULL; 441 442 sockaddr_in6_init(&tsin6, &taddr->addr6, 0, 0, 0); 443 rt_clonedmsg(RTM_MISS, sa, sin6tosa(&tsin6), NULL, ifp); 444 } 445 446 /* 447 * ND6 timer routine to expire default route list and prefix list 448 */ 449 static void 450 nd6_timer_work(struct work *wk, void *arg) 451 { 452 struct in6_ifaddr *ia6, *nia6; 453 int s, bound; 454 struct psref psref; 455 456 callout_reset(&nd6_timer_ch, nd6_prune * hz, 457 nd6_timer, NULL); 458 459 SOFTNET_KERNEL_LOCK_UNLESS_NET_MPSAFE(); 460 461 /* expire interface addresses */ 462 bound = curlwp_bind(); 463 s = pserialize_read_enter(); 464 for (ia6 = IN6_ADDRLIST_READER_FIRST(); ia6; ia6 = nia6) { 465 nia6 = IN6_ADDRLIST_READER_NEXT(ia6); 466 467 ia6_acquire(ia6, &psref); 468 pserialize_read_exit(s); 469 470 /* check address lifetime */ 471 if (IFA6_IS_INVALID(ia6)) { 472 struct ifnet *ifp; 473 474 ifp = ia6->ia_ifa.ifa_ifp; 475 IFNET_LOCK(ifp); 476 /* 477 * Need to take the lock first to prevent if_detach 478 * from running in6_purgeaddr concurrently. 479 */ 480 if (!if_is_deactivated(ifp)) { 481 ia6_release(ia6, &psref); 482 in6_purgeaddr(&ia6->ia_ifa); 483 } else { 484 /* 485 * ifp is being destroyed, ia6 will be destroyed 486 * by if_detach. 487 */ 488 ia6_release(ia6, &psref); 489 } 490 ia6 = NULL; 491 IFNET_UNLOCK(ifp); 492 } else if (IFA6_IS_DEPRECATED(ia6)) { 493 int oldflags = ia6->ia6_flags; 494 495 if ((oldflags & IN6_IFF_DEPRECATED) == 0) { 496 ia6->ia6_flags |= IN6_IFF_DEPRECATED; 497 rt_addrmsg(RTM_NEWADDR, (struct ifaddr *)ia6); 498 } 499 } else { 500 /* 501 * A new RA might have made a deprecated address 502 * preferred. 503 */ 504 if (ia6->ia6_flags & IN6_IFF_DEPRECATED) { 505 ia6->ia6_flags &= ~IN6_IFF_DEPRECATED; 506 rt_addrmsg(RTM_NEWADDR, (struct ifaddr *)ia6); 507 } 508 } 509 s = pserialize_read_enter(); 510 ia6_release(ia6, &psref); 511 } 512 pserialize_read_exit(s); 513 curlwp_bindx(bound); 514 515 SOFTNET_KERNEL_UNLOCK_UNLESS_NET_MPSAFE(); 516 } 517 518 static void 519 nd6_timer(void *ignored_arg) 520 { 521 522 workqueue_enqueue(nd6_timer_wq, &nd6_timer_wk, NULL); 523 } 524 525 /* 526 * Nuke neighbor cache/prefix/default router management table, right before 527 * ifp goes away. 528 */ 529 void 530 nd6_purge(struct ifnet *ifp, struct in6_ifextra *ext) 531 { 532 533 /* 534 * During detach, the ND info might be already removed, but 535 * then is explitly passed as argument. 536 * Otherwise get it from ifp->if_afdata. 537 */ 538 if (ext == NULL) 539 ext = ifp->if_afdata[AF_INET6]; 540 if (ext == NULL) 541 return; 542 543 /* 544 * We may not need to nuke the neighbor cache entries here 545 * because the neighbor cache is kept in if_afdata[AF_INET6]. 546 * nd6_purge() is invoked by in6_ifdetach() which is called 547 * from if_detach() where everything gets purged. However 548 * in6_ifdetach is directly called from vlan(4), so we still 549 * need to purge entries here. 550 */ 551 if (ext->lltable != NULL) 552 lltable_purge_entries(ext->lltable); 553 } 554 555 struct llentry * 556 nd6_lookup(const struct in6_addr *addr6, const struct ifnet *ifp, bool wlock) 557 { 558 struct sockaddr_in6 sin6; 559 struct llentry *ln; 560 561 sockaddr_in6_init(&sin6, addr6, 0, 0, 0); 562 563 IF_AFDATA_RLOCK(ifp); 564 ln = lla_lookup(LLTABLE6(ifp), wlock ? LLE_EXCLUSIVE : 0, 565 sin6tosa(&sin6)); 566 IF_AFDATA_RUNLOCK(ifp); 567 568 return ln; 569 } 570 571 struct llentry * 572 nd6_create(const struct in6_addr *addr6, const struct ifnet *ifp) 573 { 574 struct sockaddr_in6 sin6; 575 struct llentry *ln; 576 struct rtentry *rt; 577 578 sockaddr_in6_init(&sin6, addr6, 0, 0, 0); 579 rt = rtalloc1(sin6tosa(&sin6), 0); 580 581 IF_AFDATA_WLOCK(ifp); 582 ln = lla_create(LLTABLE6(ifp), LLE_EXCLUSIVE, sin6tosa(&sin6), rt); 583 IF_AFDATA_WUNLOCK(ifp); 584 585 if (rt != NULL) 586 rt_unref(rt); 587 if (ln != NULL) 588 ln->ln_state = ND_LLINFO_NOSTATE; 589 590 return ln; 591 } 592 593 /* 594 * Test whether a given IPv6 address is a neighbor or not, ignoring 595 * the actual neighbor cache. The neighbor cache is ignored in order 596 * to not reenter the routing code from within itself. 597 */ 598 static int 599 nd6_is_new_addr_neighbor(const struct sockaddr_in6 *addr, struct ifnet *ifp) 600 { 601 struct ifaddr *dstaddr; 602 int s; 603 604 /* 605 * A link-local address is always a neighbor. 606 * XXX: a link does not necessarily specify a single interface. 607 */ 608 if (IN6_IS_ADDR_LINKLOCAL(&addr->sin6_addr)) { 609 struct sockaddr_in6 sin6_copy; 610 u_int32_t zone; 611 612 /* 613 * We need sin6_copy since sa6_recoverscope() may modify the 614 * content (XXX). 615 */ 616 sin6_copy = *addr; 617 if (sa6_recoverscope(&sin6_copy)) 618 return 0; /* XXX: should be impossible */ 619 if (in6_setscope(&sin6_copy.sin6_addr, ifp, &zone)) 620 return 0; 621 if (sin6_copy.sin6_scope_id == zone) 622 return 1; 623 else 624 return 0; 625 } 626 627 /* 628 * If the address is assigned on the node of the other side of 629 * a p2p interface, the address should be a neighbor. 630 */ 631 s = pserialize_read_enter(); 632 dstaddr = ifa_ifwithdstaddr(sin6tocsa(addr)); 633 if (dstaddr != NULL) { 634 if (dstaddr->ifa_ifp == ifp) { 635 pserialize_read_exit(s); 636 return 1; 637 } 638 } 639 pserialize_read_exit(s); 640 641 return 0; 642 } 643 644 /* 645 * Detect if a given IPv6 address identifies a neighbor on a given link. 646 * XXX: should take care of the destination of a p2p link? 647 */ 648 int 649 nd6_is_addr_neighbor(const struct sockaddr_in6 *addr, struct ifnet *ifp) 650 { 651 struct llentry *ln; 652 struct rtentry *rt; 653 654 /* 655 * A link-local address is always a neighbor. 656 * XXX: a link does not necessarily specify a single interface. 657 */ 658 if (IN6_IS_ADDR_LINKLOCAL(&addr->sin6_addr)) { 659 struct sockaddr_in6 sin6_copy; 660 u_int32_t zone; 661 662 /* 663 * We need sin6_copy since sa6_recoverscope() may modify the 664 * content (XXX). 665 */ 666 sin6_copy = *addr; 667 if (sa6_recoverscope(&sin6_copy)) 668 return 0; /* XXX: should be impossible */ 669 if (in6_setscope(&sin6_copy.sin6_addr, ifp, &zone)) 670 return 0; 671 if (sin6_copy.sin6_scope_id == zone) 672 return 1; 673 else 674 return 0; 675 } 676 677 if (nd6_is_new_addr_neighbor(addr, ifp)) 678 return 1; 679 680 /* 681 * Even if the address matches none of our addresses, it might be 682 * in the neighbor cache or a connected route. 683 */ 684 ln = nd6_lookup(&addr->sin6_addr, ifp, false); 685 if (ln != NULL) { 686 LLE_RUNLOCK(ln); 687 return 1; 688 } 689 690 rt = rtalloc1(sin6tocsa(addr), 0); 691 if (rt == NULL) 692 return 0; 693 694 if ((rt->rt_flags & RTF_CONNECTED) && (rt->rt_ifp == ifp 695 #if NBRIDGE > 0 696 || rt->rt_ifp->if_bridge == ifp->if_bridge 697 #endif 698 #if NCARP > 0 699 || (ifp->if_type == IFT_CARP && rt->rt_ifp == ifp->if_carpdev) || 700 (rt->rt_ifp->if_type == IFT_CARP && rt->rt_ifp->if_carpdev == ifp)|| 701 (ifp->if_type == IFT_CARP && rt->rt_ifp->if_type == IFT_CARP && 702 rt->rt_ifp->if_carpdev == ifp->if_carpdev) 703 #endif 704 )) { 705 rt_unref(rt); 706 return 1; 707 } 708 rt_unref(rt); 709 710 return 0; 711 } 712 713 /* 714 * Free an nd6 llinfo entry. 715 * Since the function would cause significant changes in the kernel, DO NOT 716 * make it global, unless you have a strong reason for the change, and are sure 717 * that the change is safe. 718 */ 719 static void 720 nd6_free(struct llentry *ln, int gc) 721 { 722 struct ifnet *ifp; 723 724 KASSERT(ln != NULL); 725 LLE_WLOCK_ASSERT(ln); 726 727 /* 728 * If the reason for the deletion is just garbage collection, 729 * and the neighbor is an active router, do not delete it. 730 * Instead, reset the GC timer using the router's lifetime. 731 * XXX: the check for ln_state should be redundant, 732 * but we intentionally keep it just in case. 733 */ 734 if (!ip6_forwarding && ln->ln_router && 735 ln->ln_state == ND_LLINFO_STALE && gc) 736 { 737 nd_set_timer(ln, ND_TIMER_EXPIRE); 738 LLE_WUNLOCK(ln); 739 return; 740 } 741 742 ifp = ln->lle_tbl->llt_ifp; 743 744 if (ln->la_flags & LLE_VALID || gc) { 745 struct sockaddr_in6 sin6; 746 const char *lladdr; 747 748 sockaddr_in6_init(&sin6, &ln->r_l3addr.addr6, 0, 0, 0); 749 lladdr = ln->la_flags & LLE_VALID ? 750 (const char *)&ln->ll_addr : NULL; 751 rt_clonedmsg(RTM_DELETE, NULL, sin6tosa(&sin6), lladdr, ifp); 752 } 753 754 /* 755 * Save to unlock. We still hold an extra reference and will not 756 * free(9) in llentry_free() if someone else holds one as well. 757 */ 758 LLE_WUNLOCK(ln); 759 IF_AFDATA_LOCK(ifp); 760 LLE_WLOCK(ln); 761 762 lltable_free_entry(LLTABLE6(ifp), ln); 763 764 IF_AFDATA_UNLOCK(ifp); 765 } 766 767 /* 768 * Upper-layer reachability hint for Neighbor Unreachability Detection. 769 * 770 * XXX cost-effective methods? 771 */ 772 void 773 nd6_nud_hint(struct rtentry *rt) 774 { 775 struct llentry *ln; 776 struct ifnet *ifp; 777 778 if (rt == NULL) 779 return; 780 781 ifp = rt->rt_ifp; 782 ln = nd6_lookup(&(satocsin6(rt_getkey(rt)))->sin6_addr, ifp, true); 783 nd_nud_hint(ln); 784 } 785 786 struct gc_args { 787 int gc_entries; 788 const struct in6_addr *skip_in6; 789 }; 790 791 static int 792 nd6_purge_entry(struct lltable *llt, struct llentry *ln, void *farg) 793 { 794 struct gc_args *args = farg; 795 int *n = &args->gc_entries; 796 const struct in6_addr *skip_in6 = args->skip_in6; 797 798 if (*n <= 0) 799 return 0; 800 801 if (ND_IS_LLINFO_PERMANENT(ln)) 802 return 0; 803 804 if (IN6_ARE_ADDR_EQUAL(&ln->r_l3addr.addr6, skip_in6)) 805 return 0; 806 807 LLE_WLOCK(ln); 808 if (ln->ln_state > ND_LLINFO_INCOMPLETE) 809 ln->ln_state = ND_LLINFO_STALE; 810 else 811 ln->ln_state = ND_LLINFO_PURGE; 812 nd_set_timer(ln, ND_TIMER_IMMEDIATE); 813 LLE_WUNLOCK(ln); 814 815 (*n)--; 816 return 0; 817 } 818 819 static void 820 nd6_gc_neighbors(struct lltable *llt, const struct in6_addr *in6) 821 { 822 823 if (ip6_neighborgcthresh >= 0 && 824 lltable_get_entry_count(llt) >= ip6_neighborgcthresh) { 825 struct gc_args gc_args = {10, in6}; 826 /* 827 * XXX entries that are "less recently used" should be 828 * freed first. 829 */ 830 lltable_foreach_lle(llt, nd6_purge_entry, &gc_args); 831 } 832 } 833 834 void 835 nd6_rtrequest(int req, struct rtentry *rt, const struct rt_addrinfo *info) 836 { 837 struct sockaddr *gate = rt->rt_gateway; 838 struct ifnet *ifp = rt->rt_ifp; 839 uint8_t namelen = strlen(ifp->if_xname), addrlen = ifp->if_addrlen; 840 struct ifaddr *ifa; 841 842 RT_DPRINTF("rt_getkey(rt) = %p\n", rt_getkey(rt)); 843 844 if (req == RTM_LLINFO_UPD) { 845 int rc; 846 struct in6_addr *in6; 847 struct in6_addr in6_all; 848 int anycast; 849 850 if ((ifa = info->rti_ifa) == NULL) 851 return; 852 853 in6 = &ifatoia6(ifa)->ia_addr.sin6_addr; 854 anycast = ifatoia6(ifa)->ia6_flags & IN6_IFF_ANYCAST; 855 856 in6_all = in6addr_linklocal_allnodes; 857 if ((rc = in6_setscope(&in6_all, ifa->ifa_ifp, NULL)) != 0) { 858 log(LOG_ERR, "%s: failed to set scope %s " 859 "(errno=%d)\n", __func__, if_name(ifp), rc); 860 return; 861 } 862 863 /* XXX don't set Override for proxy addresses */ 864 nd6_na_output(ifa->ifa_ifp, &in6_all, in6, 865 (anycast ? 0 : ND_NA_FLAG_OVERRIDE) 866 #if 0 867 | (ip6_forwarding ? ND_NA_FLAG_ROUTER : 0) 868 #endif 869 , 1, NULL); 870 return; 871 } 872 873 if ((rt->rt_flags & RTF_GATEWAY) != 0) { 874 if (req != RTM_ADD) 875 return; 876 /* 877 * linklayers with particular MTU limitation. 878 */ 879 switch(ifp->if_type) { 880 #if NARCNET > 0 881 case IFT_ARCNET: 882 if (rt->rt_rmx.rmx_mtu > ARC_PHDS_MAXMTU) /* RFC2497 */ 883 rt->rt_rmx.rmx_mtu = ARC_PHDS_MAXMTU; 884 break; 885 #endif 886 } 887 return; 888 } 889 890 if (nd6_need_cache(ifp) == 0 && (rt->rt_flags & RTF_HOST) == 0) { 891 RT_DPRINTF("rt_getkey(rt) = %p\n", rt_getkey(rt)); 892 /* 893 * This is probably an interface direct route for a link 894 * which does not need neighbor caches (e.g. fe80::%lo0/64). 895 * We do not need special treatment below for such a route. 896 * Moreover, the RTF_LLINFO flag which would be set below 897 * would annoy the ndp(8) command. 898 */ 899 return; 900 } 901 902 switch (req) { 903 case RTM_ADD: { 904 struct psref psref; 905 906 RT_DPRINTF("rt_getkey(rt) = %p\n", rt_getkey(rt)); 907 /* 908 * There is no backward compatibility :) 909 * 910 * if ((rt->rt_flags & RTF_HOST) == 0 && 911 * SIN(rt_mask(rt))->sin_addr.s_addr != 0xffffffff) 912 * rt->rt_flags |= RTF_CLONING; 913 */ 914 /* XXX should move to route.c? */ 915 if (rt->rt_flags & (RTF_CONNECTED | RTF_LOCAL)) { 916 union { 917 struct sockaddr sa; 918 struct sockaddr_dl sdl; 919 struct sockaddr_storage ss; 920 } u; 921 /* 922 * Case 1: This route should come from a route to 923 * interface (RTF_CLONING case) or the route should be 924 * treated as on-link but is currently not 925 * (RTF_LLINFO && ln == NULL case). 926 */ 927 if (sockaddr_dl_init(&u.sdl, sizeof(u.ss), 928 ifp->if_index, ifp->if_type, 929 NULL, namelen, NULL, addrlen) == NULL) { 930 printf("%s.%d: sockaddr_dl_init(, %zu, ) " 931 "failed on %s\n", __func__, __LINE__, 932 sizeof(u.ss), if_name(ifp)); 933 } 934 rt_setgate(rt, &u.sa); 935 gate = rt->rt_gateway; 936 RT_DPRINTF("rt_getkey(rt) = %p\n", rt_getkey(rt)); 937 if (gate == NULL) { 938 log(LOG_ERR, 939 "%s: rt_setgate failed on %s\n", __func__, 940 if_name(ifp)); 941 break; 942 } 943 944 RT_DPRINTF("rt_getkey(rt) = %p\n", rt_getkey(rt)); 945 if ((rt->rt_flags & RTF_CONNECTED) != 0) 946 break; 947 } 948 RT_DPRINTF("rt_getkey(rt) = %p\n", rt_getkey(rt)); 949 /* 950 * In IPv4 code, we try to annonuce new RTF_ANNOUNCE entry here. 951 * We don't do that here since llinfo is not ready yet. 952 * 953 * There are also couple of other things to be discussed: 954 * - unsolicited NA code needs improvement beforehand 955 * - RFC2461 says we MAY send multicast unsolicited NA 956 * (7.2.6 paragraph 4), however, it also says that we 957 * SHOULD provide a mechanism to prevent multicast NA storm. 958 * we don't have anything like it right now. 959 * note that the mechanism needs a mutual agreement 960 * between proxies, which means that we need to implement 961 * a new protocol, or a new kludge. 962 * - from RFC2461 6.2.4, host MUST NOT send an unsolicited NA. 963 * we need to check ip6forwarding before sending it. 964 * (or should we allow proxy ND configuration only for 965 * routers? there's no mention about proxy ND from hosts) 966 */ 967 #if 0 968 /* XXX it does not work */ 969 if (rt->rt_flags & RTF_ANNOUNCE) 970 nd6_na_output(ifp, 971 &satocsin6(rt_getkey(rt))->sin6_addr, 972 &satocsin6(rt_getkey(rt))->sin6_addr, 973 ip6_forwarding ? ND_NA_FLAG_ROUTER : 0, 974 1, NULL); 975 #endif 976 977 if ((ifp->if_flags & (IFF_POINTOPOINT | IFF_LOOPBACK)) == 0) { 978 RT_DPRINTF("rt_getkey(rt) = %p\n", rt_getkey(rt)); 979 /* 980 * Address resolution isn't necessary for a point to 981 * point link, so we can skip this test for a p2p link. 982 */ 983 if (gate->sa_family != AF_LINK || 984 gate->sa_len < 985 sockaddr_dl_measure(namelen, addrlen)) { 986 log(LOG_DEBUG, 987 "nd6_rtrequest: bad gateway value: %s\n", 988 if_name(ifp)); 989 break; 990 } 991 satosdl(gate)->sdl_type = ifp->if_type; 992 satosdl(gate)->sdl_index = ifp->if_index; 993 RT_DPRINTF("rt_getkey(rt) = %p\n", rt_getkey(rt)); 994 } 995 RT_DPRINTF("rt_getkey(rt) = %p\n", rt_getkey(rt)); 996 997 /* 998 * When called from rt_ifa_addlocal, we cannot depend on that 999 * the address (rt_getkey(rt)) exits in the address list of the 1000 * interface. So check RTF_LOCAL instead. 1001 */ 1002 if (rt->rt_flags & RTF_LOCAL) { 1003 if (nd6_useloopback) 1004 rt->rt_ifp = lo0ifp; /* XXX */ 1005 break; 1006 } 1007 1008 /* 1009 * check if rt_getkey(rt) is an address assigned 1010 * to the interface. 1011 */ 1012 ifa = (struct ifaddr *)in6ifa_ifpwithaddr_psref(ifp, 1013 &satocsin6(rt_getkey(rt))->sin6_addr, &psref); 1014 if (ifa != NULL) { 1015 if (nd6_useloopback) { 1016 rt->rt_ifp = lo0ifp; /* XXX */ 1017 /* 1018 * Make sure rt_ifa be equal to the ifaddr 1019 * corresponding to the address. 1020 * We need this because when we refer 1021 * rt_ifa->ia6_flags in ip6_input, we assume 1022 * that the rt_ifa points to the address instead 1023 * of the loopback address. 1024 */ 1025 if (!ISSET(info->rti_flags, RTF_DONTCHANGEIFA) 1026 && ifa != rt->rt_ifa) 1027 rt_replace_ifa(rt, ifa); 1028 } 1029 } else if (rt->rt_flags & RTF_ANNOUNCE) { 1030 /* join solicited node multicast for proxy ND */ 1031 if (ifp->if_flags & IFF_MULTICAST) { 1032 struct in6_addr llsol; 1033 int error; 1034 1035 llsol = satocsin6(rt_getkey(rt))->sin6_addr; 1036 llsol.s6_addr32[0] = htonl(0xff020000); 1037 llsol.s6_addr32[1] = 0; 1038 llsol.s6_addr32[2] = htonl(1); 1039 llsol.s6_addr8[12] = 0xff; 1040 if (in6_setscope(&llsol, ifp, NULL)) 1041 goto out; 1042 if (!in6_addmulti(&llsol, ifp, &error, 0)) { 1043 char ip6buf[INET6_ADDRSTRLEN]; 1044 nd6log(LOG_ERR, "%s: failed to join " 1045 "%s (errno=%d)\n", if_name(ifp), 1046 IN6_PRINT(ip6buf, &llsol), error); 1047 } 1048 } 1049 } 1050 out: 1051 ifa_release(ifa, &psref); 1052 /* 1053 * If we have too many cache entries, initiate immediate 1054 * purging for some entries. 1055 */ 1056 if (rt->rt_ifp != NULL) 1057 nd6_gc_neighbors(LLTABLE6(rt->rt_ifp), NULL); 1058 break; 1059 } 1060 1061 case RTM_DELETE: 1062 /* leave from solicited node multicast for proxy ND */ 1063 if ((rt->rt_flags & RTF_ANNOUNCE) != 0 && 1064 (ifp->if_flags & IFF_MULTICAST) != 0) { 1065 struct in6_addr llsol; 1066 1067 llsol = satocsin6(rt_getkey(rt))->sin6_addr; 1068 llsol.s6_addr32[0] = htonl(0xff020000); 1069 llsol.s6_addr32[1] = 0; 1070 llsol.s6_addr32[2] = htonl(1); 1071 llsol.s6_addr8[12] = 0xff; 1072 if (in6_setscope(&llsol, ifp, NULL) == 0) 1073 in6_lookup_and_delete_multi(&llsol, ifp); 1074 } 1075 break; 1076 } 1077 } 1078 1079 static void 1080 nd6_setifflags(struct ifnet *ifp, uint32_t flags) 1081 { 1082 struct nd_kifinfo *ndi = ND_IFINFO(ifp); 1083 struct ifaddr *ifa; 1084 struct in6_ifaddr *ia; 1085 int s; 1086 1087 if (ndi->flags & ND6_IFF_IFDISABLED && !(flags & ND6_IFF_IFDISABLED)) { 1088 /* 1089 * If the interface is marked as ND6_IFF_IFDISABLED and 1090 * has a link-local address with IN6_IFF_DUPLICATED, 1091 * do not clear ND6_IFF_IFDISABLED. 1092 * See RFC 4862, section 5.4.5. 1093 */ 1094 bool duplicated_linklocal = false; 1095 1096 s = pserialize_read_enter(); 1097 IFADDR_READER_FOREACH(ifa, ifp) { 1098 if (ifa->ifa_addr->sa_family != AF_INET6) 1099 continue; 1100 ia = (struct in6_ifaddr *)ifa; 1101 if ((ia->ia6_flags & IN6_IFF_DUPLICATED) && 1102 IN6_IS_ADDR_LINKLOCAL(IA6_IN6(ia))) 1103 { 1104 duplicated_linklocal = true; 1105 break; 1106 } 1107 } 1108 pserialize_read_exit(s); 1109 1110 if (duplicated_linklocal) { 1111 flags |= ND6_IFF_IFDISABLED; 1112 log(LOG_ERR, "%s: Cannot enable an interface" 1113 " with a link-local address marked" 1114 " duplicate.\n", if_name(ifp)); 1115 } else { 1116 ndi->flags &= ~ND6_IFF_IFDISABLED; 1117 if (ifp->if_flags & IFF_UP) 1118 in6_if_up(ifp); 1119 } 1120 } else if (!(ndi->flags & ND6_IFF_IFDISABLED) && 1121 (flags & ND6_IFF_IFDISABLED)) 1122 { 1123 struct psref psref; 1124 int bound = curlwp_bind(); 1125 1126 /* Mark all IPv6 addresses as tentative. */ 1127 1128 ndi->flags |= ND6_IFF_IFDISABLED; 1129 s = pserialize_read_enter(); 1130 IFADDR_READER_FOREACH(ifa, ifp) { 1131 if (ifa->ifa_addr->sa_family != AF_INET6) 1132 continue; 1133 ifa_acquire(ifa, &psref); 1134 pserialize_read_exit(s); 1135 1136 nd6_dad_stop(ifa); 1137 1138 ia = (struct in6_ifaddr *)ifa; 1139 ia->ia6_flags |= IN6_IFF_TENTATIVE; 1140 1141 s = pserialize_read_enter(); 1142 ifa_release(ifa, &psref); 1143 } 1144 pserialize_read_exit(s); 1145 curlwp_bindx(bound); 1146 } 1147 1148 if (flags & ND6_IFF_AUTO_LINKLOCAL) { 1149 if (!(ndi->flags & ND6_IFF_AUTO_LINKLOCAL)) { 1150 /* auto_linklocal 0->1 transition */ 1151 1152 ndi->flags |= ND6_IFF_AUTO_LINKLOCAL; 1153 in6_ifattach(ifp, NULL); 1154 } else if (!(flags & ND6_IFF_IFDISABLED) && 1155 ifp->if_flags & IFF_UP) 1156 { 1157 /* 1158 * When the IF already has 1159 * ND6_IFF_AUTO_LINKLOCAL, no link-local 1160 * address is assigned, and IFF_UP, try to 1161 * assign one. 1162 */ 1163 bool haslinklocal = 0; 1164 1165 s = pserialize_read_enter(); 1166 IFADDR_READER_FOREACH(ifa, ifp) { 1167 if (ifa->ifa_addr->sa_family !=AF_INET6) 1168 continue; 1169 ia = (struct in6_ifaddr *)ifa; 1170 if (IN6_IS_ADDR_LINKLOCAL(IA6_IN6(ia))){ 1171 haslinklocal = true; 1172 break; 1173 } 1174 } 1175 pserialize_read_exit(s); 1176 if (!haslinklocal) 1177 in6_ifattach(ifp, NULL); 1178 } 1179 } 1180 1181 ndi->flags = flags; 1182 } 1183 1184 int 1185 nd6_ioctl(u_long cmd, void *data, struct ifnet *ifp) 1186 { 1187 #ifdef OSIOCGIFINFO_IN6_90 1188 struct in6_ndireq90 *ondi = (struct in6_ndireq90 *)data; 1189 struct in6_ndifreq90 *ndif = (struct in6_ndifreq90 *)data; 1190 #define OND ondi->ndi 1191 #endif 1192 struct in6_ndireq *ndi = (struct in6_ndireq *)data; 1193 struct in6_nbrinfo *nbi = (struct in6_nbrinfo *)data; 1194 struct nd_kifinfo *ifndi = ND_IFINFO(ifp); 1195 int error = 0; 1196 #define ND ndi->ndi 1197 1198 switch (cmd) { 1199 #ifdef OSIOCSRTRFLUSH_IN6 1200 case OSIOCGDRLST_IN6: /* FALLTHROUGH */ 1201 case OSIOCGPRLST_IN6: /* FALLTHROUGH */ 1202 case OSIOCSNDFLUSH_IN6: /* FALLTHROUGH */ 1203 case OSIOCSPFXFLUSH_IN6: /* FALLTHROUGH */ 1204 case OSIOCSRTRFLUSH_IN6: /* FALLTHROUGH */ 1205 break; 1206 case OSIOCGDEFIFACE_IN6: 1207 ndif->ifindex = 0; 1208 break; 1209 case OSIOCSDEFIFACE_IN6: 1210 error = ENOTSUP; 1211 break; 1212 #endif 1213 #ifdef OSIOCGIFINFO_IN6 1214 case OSIOCGIFINFO_IN6: /* FALLTHROUGH */ 1215 #endif 1216 #ifdef OSIOCGIFINFO_IN6_90 1217 case OSIOCGIFINFO_IN6_90: 1218 memset(&OND, 0, sizeof(OND)); 1219 OND.initialized = 1; 1220 OND.chlim = ifndi->chlim; 1221 OND.basereachable = ifndi->basereachable; 1222 OND.retrans = ifndi->retrans; 1223 OND.flags = ifndi->flags; 1224 break; 1225 case OSIOCSIFINFO_IN6_90: 1226 /* Allow userland to set Neighbor Unreachability Detection 1227 * timers. */ 1228 if (OND.chlim != 0) 1229 ifndi->chlim = OND.chlim; 1230 if (OND.basereachable != 0 && 1231 OND.basereachable != ifndi->basereachable) 1232 { 1233 ifndi->basereachable = OND.basereachable; 1234 ifndi->reachable = ND_COMPUTE_RTIME(OND.basereachable); 1235 } 1236 if (OND.retrans != 0) 1237 ifndi->retrans = OND.retrans; 1238 /* Retain the old behaviour .... */ 1239 /* FALLTHROUGH */ 1240 case OSIOCSIFINFO_FLAGS_90: 1241 nd6_setifflags(ifp, OND.flags); 1242 break; 1243 #undef OND 1244 #endif 1245 case SIOCGIFINFO_IN6: 1246 ND.chlim = ifndi->chlim; 1247 ND.basereachable = ifndi->basereachable; 1248 ND.retrans = ifndi->retrans; 1249 ND.flags = ifndi->flags; 1250 break; 1251 case SIOCSIFINFO_IN6: 1252 /* Allow userland to set Neighbor Unreachability Detection 1253 * timers. */ 1254 if (ND.chlim != 0) 1255 ifndi->chlim = ND.chlim; 1256 if (ND.basereachable != 0 && 1257 ND.basereachable != ifndi->basereachable) 1258 { 1259 ifndi->basereachable = ND.basereachable; 1260 ifndi->reachable = ND_COMPUTE_RTIME(ND.basereachable); 1261 } 1262 if (ND.retrans != 0) 1263 ifndi->retrans = ND.retrans; 1264 break; 1265 case SIOCSIFINFO_FLAGS: 1266 nd6_setifflags(ifp, ND.flags); 1267 break; 1268 #undef ND 1269 case SIOCGNBRINFO_IN6: 1270 { 1271 struct llentry *ln; 1272 struct in6_addr nb_addr = nbi->addr; /* make local for safety */ 1273 1274 if ((error = in6_setscope(&nb_addr, ifp, NULL)) != 0) 1275 return error; 1276 1277 ln = nd6_lookup(&nb_addr, ifp, false); 1278 if (ln == NULL) { 1279 error = EINVAL; 1280 break; 1281 } 1282 nbi->state = ln->ln_state; 1283 nbi->asked = ln->ln_asked; 1284 nbi->isrouter = ln->ln_router; 1285 nbi->expire = ln->ln_expire ? 1286 time_mono_to_wall(ln->ln_expire) : 0; 1287 LLE_RUNLOCK(ln); 1288 1289 break; 1290 } 1291 } 1292 return error; 1293 } 1294 1295 void 1296 nd6_llinfo_release_pkts(struct llentry *ln, struct ifnet *ifp) 1297 { 1298 struct mbuf *m_hold, *m_hold_next; 1299 struct sockaddr_in6 sin6; 1300 1301 LLE_WLOCK_ASSERT(ln); 1302 1303 sockaddr_in6_init(&sin6, &ln->r_l3addr.addr6, 0, 0, 0); 1304 1305 m_hold = ln->la_hold, ln->la_hold = NULL, ln->la_numheld = 0; 1306 1307 LLE_ADDREF(ln); 1308 LLE_WUNLOCK(ln); 1309 for (; m_hold != NULL; m_hold = m_hold_next) { 1310 m_hold_next = m_hold->m_nextpkt; 1311 m_hold->m_nextpkt = NULL; 1312 1313 /* 1314 * we assume ifp is not a p2p here, so 1315 * just set the 2nd argument as the 1316 * 1st one. 1317 */ 1318 ip6_if_output(ifp, ifp, m_hold, &sin6, NULL); 1319 } 1320 LLE_WLOCK(ln); 1321 LLE_REMREF(ln); 1322 } 1323 1324 /* 1325 * Create neighbor cache entry and cache link-layer address, 1326 * on reception of inbound ND6 packets. (RS/RA/NS/redirect) 1327 */ 1328 void 1329 nd6_cache_lladdr( 1330 struct ifnet *ifp, 1331 struct in6_addr *from, 1332 char *lladdr, 1333 int lladdrlen, 1334 int type, /* ICMP6 type */ 1335 int code /* type dependent information */ 1336 ) 1337 { 1338 struct llentry *ln = NULL; 1339 int is_newentry; 1340 int do_update; 1341 int olladdr; 1342 int llchange; 1343 int newstate = 0; 1344 1345 KASSERT(ifp != NULL); 1346 KASSERT(from != NULL); 1347 1348 /* nothing must be updated for unspecified address */ 1349 if (IN6_IS_ADDR_UNSPECIFIED(from)) 1350 return; 1351 1352 /* 1353 * Validation about ifp->if_addrlen and lladdrlen must be done in 1354 * the caller. 1355 * 1356 * XXX If the link does not have link-layer adderss, what should 1357 * we do? (ifp->if_addrlen == 0) 1358 * Spec says nothing in sections for RA, RS and NA. There's small 1359 * description on it in NS section (RFC 2461 7.2.3). 1360 */ 1361 1362 ln = nd6_lookup(from, ifp, true); 1363 if (ln == NULL) { 1364 #if 0 1365 /* nothing must be done if there's no lladdr */ 1366 if (!lladdr || !lladdrlen) 1367 return NULL; 1368 #endif 1369 1370 ln = nd6_create(from, ifp); 1371 is_newentry = 1; 1372 } else { 1373 /* do nothing if static ndp is set */ 1374 if (ln->la_flags & LLE_STATIC) { 1375 LLE_WUNLOCK(ln); 1376 return; 1377 } 1378 is_newentry = 0; 1379 } 1380 1381 if (ln == NULL) 1382 return; 1383 1384 olladdr = (ln->la_flags & LLE_VALID) ? 1 : 0; 1385 if (olladdr && lladdr) { 1386 llchange = memcmp(lladdr, &ln->ll_addr, ifp->if_addrlen); 1387 } else 1388 llchange = 0; 1389 1390 /* 1391 * newentry olladdr lladdr llchange (*=record) 1392 * 0 n n -- (1) 1393 * 0 y n -- (2) 1394 * 0 n y -- (3) * STALE 1395 * 0 y y n (4) * 1396 * 0 y y y (5) * STALE 1397 * 1 -- n -- (6) NOSTATE(= PASSIVE) 1398 * 1 -- y -- (7) * STALE 1399 */ 1400 1401 if (lladdr) { /* (3-5) and (7) */ 1402 /* 1403 * Record source link-layer address 1404 * XXX is it dependent to ifp->if_type? 1405 */ 1406 memcpy(&ln->ll_addr, lladdr, ifp->if_addrlen); 1407 ln->la_flags |= LLE_VALID; 1408 } 1409 1410 if (!is_newentry) { 1411 if ((!olladdr && lladdr) || /* (3) */ 1412 (olladdr && lladdr && llchange)) { /* (5) */ 1413 do_update = 1; 1414 newstate = ND_LLINFO_STALE; 1415 } else /* (1-2,4) */ 1416 do_update = 0; 1417 } else { 1418 do_update = 1; 1419 if (lladdr == NULL) /* (6) */ 1420 newstate = ND_LLINFO_NOSTATE; 1421 else /* (7) */ 1422 newstate = ND_LLINFO_STALE; 1423 } 1424 1425 if (do_update) { 1426 /* 1427 * Update the state of the neighbor cache. 1428 */ 1429 ln->ln_state = newstate; 1430 1431 if (ln->ln_state == ND_LLINFO_STALE) { 1432 /* 1433 * XXX: since nd6_output() below will cause 1434 * state tansition to DELAY and reset the timer, 1435 * we must set the timer now, although it is actually 1436 * meaningless. 1437 */ 1438 nd_set_timer(ln, ND_TIMER_GC); 1439 1440 nd6_llinfo_release_pkts(ln, ifp); 1441 } else if (ln->ln_state == ND_LLINFO_INCOMPLETE) { 1442 /* probe right away */ 1443 nd_set_timer(ln, ND_TIMER_IMMEDIATE); 1444 } 1445 } 1446 1447 /* 1448 * ICMP6 type dependent behavior. 1449 * 1450 * NS: clear IsRouter if new entry 1451 * RS: clear IsRouter 1452 * RA: set IsRouter if there's lladdr 1453 * redir: clear IsRouter if new entry 1454 * 1455 * RA case, (1): 1456 * The spec says that we must set IsRouter in the following cases: 1457 * - If lladdr exist, set IsRouter. This means (1-5). 1458 * - If it is old entry (!newentry), set IsRouter. This means (7). 1459 * So, based on the spec, in (1-5) and (7) cases we must set IsRouter. 1460 * A question arises for (1) case. (1) case has no lladdr in the 1461 * neighbor cache, this is similar to (6). 1462 * This case is rare but we figured that we MUST NOT set IsRouter. 1463 * 1464 * newentry olladdr lladdr llchange NS RS RA redir 1465 * D R 1466 * 0 n n -- (1) c ? s 1467 * 0 y n -- (2) c s s 1468 * 0 n y -- (3) c s s 1469 * 0 y y n (4) c s s 1470 * 0 y y y (5) c s s 1471 * 1 -- n -- (6) c c c s 1472 * 1 -- y -- (7) c c s c s 1473 * 1474 * (c=clear s=set) 1475 */ 1476 switch (type & 0xff) { 1477 case ND_NEIGHBOR_SOLICIT: 1478 /* 1479 * New entry must have is_router flag cleared. 1480 */ 1481 if (is_newentry) /* (6-7) */ 1482 ln->ln_router = 0; 1483 break; 1484 case ND_REDIRECT: 1485 /* 1486 * If the icmp is a redirect to a better router, always set the 1487 * is_router flag. Otherwise, if the entry is newly created, 1488 * clear the flag. [RFC 2461, sec 8.3] 1489 */ 1490 if (code == ND_REDIRECT_ROUTER) 1491 ln->ln_router = 1; 1492 else if (is_newentry) /* (6-7) */ 1493 ln->ln_router = 0; 1494 break; 1495 case ND_ROUTER_SOLICIT: 1496 /* 1497 * is_router flag must always be cleared. 1498 */ 1499 ln->ln_router = 0; 1500 break; 1501 case ND_ROUTER_ADVERT: 1502 /* 1503 * Mark an entry with lladdr as a router. 1504 */ 1505 if ((!is_newentry && (olladdr || lladdr)) || /* (2-5) */ 1506 (is_newentry && lladdr)) { /* (7) */ 1507 ln->ln_router = 1; 1508 } 1509 break; 1510 } 1511 1512 if (do_update && lladdr != NULL) { 1513 struct sockaddr_in6 sin6; 1514 1515 sockaddr_in6_init(&sin6, from, 0, 0, 0); 1516 rt_clonedmsg(is_newentry ? RTM_ADD : RTM_CHANGE, 1517 NULL, sin6tosa(&sin6), lladdr, ifp); 1518 } 1519 1520 if (ln != NULL) 1521 LLE_WUNLOCK(ln); 1522 1523 /* 1524 * If we have too many cache entries, initiate immediate 1525 * purging for some entries. 1526 */ 1527 if (is_newentry) 1528 nd6_gc_neighbors(LLTABLE6(ifp), &ln->r_l3addr.addr6); 1529 } 1530 1531 static void 1532 nd6_slowtimo(void *ignored_arg) 1533 { 1534 struct nd_kifinfo *ndi; 1535 struct ifnet *ifp; 1536 struct psref psref; 1537 int s; 1538 1539 SOFTNET_KERNEL_LOCK_UNLESS_NET_MPSAFE(); 1540 callout_reset(&nd6_slowtimo_ch, ND6_SLOWTIMER_INTERVAL * hz, 1541 nd6_slowtimo, NULL); 1542 1543 s = pserialize_read_enter(); 1544 IFNET_READER_FOREACH(ifp) { 1545 ndi = ND_IFINFO(ifp); 1546 if (ndi->basereachable && /* already initialized */ 1547 (ndi->recalctm -= ND6_SLOWTIMER_INTERVAL) <= 0) { 1548 if_acquire(ifp, &psref); 1549 pserialize_read_exit(s); 1550 /* 1551 * Since reachable time rarely changes by router 1552 * advertisements, we SHOULD insure that a new random 1553 * value gets recomputed at least once every few hours. 1554 * (RFC 2461, 6.3.4) 1555 */ 1556 ndi->recalctm = nd6_recalc_reachtm_interval; 1557 ndi->reachable = ND_COMPUTE_RTIME(ndi->basereachable); 1558 s = pserialize_read_enter(); 1559 if_release(ifp, &psref); 1560 } 1561 } 1562 pserialize_read_exit(s); 1563 1564 SOFTNET_KERNEL_UNLOCK_UNLESS_NET_MPSAFE(); 1565 } 1566 1567 /* 1568 * Return 0 if a neighbor cache is found. Return EWOULDBLOCK if a cache is not 1569 * found and trying to resolve a neighbor; in this case the mbuf is queued in 1570 * the list. Otherwise return errno after freeing the mbuf. 1571 */ 1572 int 1573 nd6_resolve(struct ifnet *ifp, const struct rtentry *rt, struct mbuf *m, 1574 const struct sockaddr *_dst, uint8_t *lldst, size_t dstsize) 1575 { 1576 struct llentry *ln = NULL; 1577 bool created = false; 1578 const struct sockaddr_in6 *dst = satocsin6(_dst); 1579 int error; 1580 struct nd_kifinfo *ndi = ND_IFINFO(ifp); 1581 1582 /* discard the packet if IPv6 operation is disabled on the interface */ 1583 if (ndi->flags & ND6_IFF_IFDISABLED) { 1584 m_freem(m); 1585 return ENETDOWN; /* better error? */ 1586 } 1587 1588 /* 1589 * Address resolution or Neighbor Unreachability Detection 1590 * for the next hop. 1591 * At this point, the destination of the packet must be a unicast 1592 * or an anycast address(i.e. not a multicast). 1593 */ 1594 1595 /* Look up the neighbor cache for the nexthop */ 1596 ln = nd6_lookup(&dst->sin6_addr, ifp, false); 1597 1598 if (ln != NULL && (ln->la_flags & LLE_VALID) != 0 && 1599 ln->ln_state == ND_LLINFO_REACHABLE) { 1600 /* Fast path */ 1601 memcpy(lldst, &ln->ll_addr, MIN(dstsize, ifp->if_addrlen)); 1602 LLE_RUNLOCK(ln); 1603 return 0; 1604 } 1605 if (ln != NULL) 1606 LLE_RUNLOCK(ln); 1607 1608 /* Slow path */ 1609 ln = nd6_lookup(&dst->sin6_addr, ifp, true); 1610 if (ln == NULL && nd6_is_addr_neighbor(dst, ifp)) { 1611 /* 1612 * Since nd6_is_addr_neighbor() internally calls nd6_lookup(), 1613 * the condition below is not very efficient. But we believe 1614 * it is tolerable, because this should be a rare case. 1615 */ 1616 ln = nd6_create(&dst->sin6_addr, ifp); 1617 if (ln == NULL) { 1618 char ip6buf[INET6_ADDRSTRLEN]; 1619 log(LOG_DEBUG, 1620 "%s: can't allocate llinfo for %s " 1621 "(ln=%p, rt=%p)\n", __func__, 1622 IN6_PRINT(ip6buf, &dst->sin6_addr), ln, rt); 1623 m_freem(m); 1624 return ENOBUFS; 1625 } 1626 created = true; 1627 } 1628 1629 if (ln == NULL) { 1630 m_freem(m); 1631 return ENETDOWN; /* better error? */ 1632 } 1633 1634 error = nd_resolve(ln, rt, m, lldst, dstsize); 1635 1636 if (created) 1637 nd6_gc_neighbors(LLTABLE6(ifp), &dst->sin6_addr); 1638 1639 return error; 1640 } 1641 1642 int 1643 nd6_need_cache(struct ifnet *ifp) 1644 { 1645 /* 1646 * XXX: we currently do not make neighbor cache on any interface 1647 * other than ARCnet, Ethernet, and GIF. 1648 * 1649 * RFC2893 says: 1650 * - unidirectional tunnels needs no ND 1651 */ 1652 switch (ifp->if_type) { 1653 case IFT_ARCNET: 1654 case IFT_ETHER: 1655 case IFT_IEEE1394: 1656 case IFT_CARP: 1657 case IFT_GIF: /* XXX need more cases? */ 1658 case IFT_IPSEC: 1659 case IFT_PPP: 1660 case IFT_TUNNEL: 1661 return 1; 1662 default: 1663 return 0; 1664 } 1665 } 1666 1667 int 1668 nd6_sysctl( 1669 int name, 1670 void *oldp, /* syscall arg, need copyout */ 1671 size_t *oldlenp, 1672 void *newp, /* syscall arg, need copyin */ 1673 size_t newlen 1674 ) 1675 { 1676 int error; 1677 1678 if (newp) 1679 return EPERM; 1680 1681 switch (name) { 1682 1683 /* call the nd6 compat_90 hook to validate the nd6-related names */ 1684 case OICMPV6CTL_ND6_DRLIST: /* FALLTHROUGH */ 1685 case OICMPV6CTL_ND6_PRLIST: 1686 MODULE_HOOK_CALL(net_inet6_nd_90_hook, (name), ENOPROTOOPT, 1687 error); 1688 if (error == 0) 1689 *oldlenp = 0; 1690 return error; 1691 1692 case ICMPV6CTL_ND6_MAXQLEN: 1693 return 0; 1694 default: 1695 return ENOPROTOOPT; 1696 } 1697 } 1698