1 /* $NetBSD: nd6.c,v 1.284 2025/06/05 06:31:07 ozaki-r 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 1.284 2025/06/05 06:31:07 ozaki-r 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 ifa = in6ifa_first_lladdr(ifp); 1167 if (ifa != NULL) 1168 haslinklocal = true; 1169 pserialize_read_exit(s); 1170 if (!haslinklocal) 1171 in6_ifattach(ifp, NULL); 1172 } 1173 } 1174 1175 ndi->flags = flags; 1176 } 1177 1178 int 1179 nd6_ioctl(u_long cmd, void *data, struct ifnet *ifp) 1180 { 1181 #ifdef OSIOCGIFINFO_IN6_90 1182 struct in6_ndireq90 *ondi = (struct in6_ndireq90 *)data; 1183 struct in6_ndifreq90 *ndif = (struct in6_ndifreq90 *)data; 1184 #define OND ondi->ndi 1185 #endif 1186 struct in6_ndireq *ndi = (struct in6_ndireq *)data; 1187 struct in6_nbrinfo *nbi = (struct in6_nbrinfo *)data; 1188 struct nd_kifinfo *ifndi = ND_IFINFO(ifp); 1189 int error = 0; 1190 #define ND ndi->ndi 1191 1192 switch (cmd) { 1193 #ifdef OSIOCSRTRFLUSH_IN6 1194 case OSIOCGDRLST_IN6: /* FALLTHROUGH */ 1195 case OSIOCGPRLST_IN6: /* FALLTHROUGH */ 1196 case OSIOCSNDFLUSH_IN6: /* FALLTHROUGH */ 1197 case OSIOCSPFXFLUSH_IN6: /* FALLTHROUGH */ 1198 case OSIOCSRTRFLUSH_IN6: /* FALLTHROUGH */ 1199 break; 1200 case OSIOCGDEFIFACE_IN6: 1201 ndif->ifindex = 0; 1202 break; 1203 case OSIOCSDEFIFACE_IN6: 1204 error = ENOTSUP; 1205 break; 1206 #endif 1207 #ifdef OSIOCGIFINFO_IN6 1208 case OSIOCGIFINFO_IN6: /* FALLTHROUGH */ 1209 #endif 1210 #ifdef OSIOCGIFINFO_IN6_90 1211 case OSIOCGIFINFO_IN6_90: 1212 memset(&OND, 0, sizeof(OND)); 1213 OND.initialized = 1; 1214 OND.chlim = ifndi->chlim; 1215 OND.basereachable = ifndi->basereachable; 1216 OND.retrans = ifndi->retrans; 1217 OND.flags = ifndi->flags; 1218 break; 1219 case OSIOCSIFINFO_IN6_90: 1220 /* Allow userland to set Neighbor Unreachability Detection 1221 * timers. */ 1222 if (OND.chlim != 0) 1223 ifndi->chlim = OND.chlim; 1224 if (OND.basereachable != 0 && 1225 OND.basereachable != ifndi->basereachable) 1226 { 1227 ifndi->basereachable = OND.basereachable; 1228 ifndi->reachable = ND_COMPUTE_RTIME(OND.basereachable); 1229 } 1230 if (OND.retrans != 0) 1231 ifndi->retrans = OND.retrans; 1232 /* Retain the old behaviour .... */ 1233 /* FALLTHROUGH */ 1234 case OSIOCSIFINFO_FLAGS_90: 1235 nd6_setifflags(ifp, OND.flags); 1236 break; 1237 #undef OND 1238 #endif 1239 case SIOCGIFINFO_IN6: 1240 ND.chlim = ifndi->chlim; 1241 ND.basereachable = ifndi->basereachable; 1242 ND.retrans = ifndi->retrans; 1243 ND.flags = ifndi->flags; 1244 break; 1245 case SIOCSIFINFO_IN6: 1246 /* Allow userland to set Neighbor Unreachability Detection 1247 * timers. */ 1248 if (ND.chlim != 0) 1249 ifndi->chlim = ND.chlim; 1250 if (ND.basereachable != 0 && 1251 ND.basereachable != ifndi->basereachable) 1252 { 1253 ifndi->basereachable = ND.basereachable; 1254 ifndi->reachable = ND_COMPUTE_RTIME(ND.basereachable); 1255 } 1256 if (ND.retrans != 0) 1257 ifndi->retrans = ND.retrans; 1258 break; 1259 case SIOCSIFINFO_FLAGS: 1260 nd6_setifflags(ifp, ND.flags); 1261 break; 1262 #undef ND 1263 case SIOCGNBRINFO_IN6: 1264 { 1265 struct llentry *ln; 1266 struct in6_addr nb_addr = nbi->addr; /* make local for safety */ 1267 1268 if ((error = in6_setscope(&nb_addr, ifp, NULL)) != 0) 1269 return error; 1270 1271 ln = nd6_lookup(&nb_addr, ifp, false); 1272 if (ln == NULL) { 1273 error = EINVAL; 1274 break; 1275 } 1276 nbi->state = ln->ln_state; 1277 nbi->asked = ln->ln_asked; 1278 nbi->isrouter = ln->ln_router; 1279 nbi->expire = ln->ln_expire ? 1280 time_mono_to_wall(ln->ln_expire) : 0; 1281 LLE_RUNLOCK(ln); 1282 1283 break; 1284 } 1285 } 1286 return error; 1287 } 1288 1289 void 1290 nd6_llinfo_release_pkts(struct llentry *ln, struct ifnet *ifp) 1291 { 1292 struct mbuf *m_hold, *m_hold_next; 1293 struct sockaddr_in6 sin6; 1294 1295 LLE_WLOCK_ASSERT(ln); 1296 1297 sockaddr_in6_init(&sin6, &ln->r_l3addr.addr6, 0, 0, 0); 1298 1299 m_hold = ln->la_hold, ln->la_hold = NULL, ln->la_numheld = 0; 1300 1301 LLE_ADDREF(ln); 1302 LLE_WUNLOCK(ln); 1303 for (; m_hold != NULL; m_hold = m_hold_next) { 1304 m_hold_next = m_hold->m_nextpkt; 1305 m_hold->m_nextpkt = NULL; 1306 1307 /* 1308 * we assume ifp is not a p2p here, so 1309 * just set the 2nd argument as the 1310 * 1st one. 1311 */ 1312 ip6_if_output(ifp, ifp, m_hold, &sin6, NULL); 1313 } 1314 LLE_WLOCK(ln); 1315 LLE_REMREF(ln); 1316 } 1317 1318 /* 1319 * Create neighbor cache entry and cache link-layer address, 1320 * on reception of inbound ND6 packets. (RS/RA/NS/redirect) 1321 */ 1322 void 1323 nd6_cache_lladdr( 1324 struct ifnet *ifp, 1325 struct in6_addr *from, 1326 char *lladdr, 1327 int lladdrlen, 1328 int type, /* ICMP6 type */ 1329 int code /* type dependent information */ 1330 ) 1331 { 1332 struct llentry *ln = NULL; 1333 int is_newentry; 1334 int do_update; 1335 int olladdr; 1336 int llchange; 1337 int newstate = 0; 1338 1339 KASSERT(ifp != NULL); 1340 KASSERT(from != NULL); 1341 1342 /* nothing must be updated for unspecified address */ 1343 if (IN6_IS_ADDR_UNSPECIFIED(from)) 1344 return; 1345 1346 /* 1347 * Validation about ifp->if_addrlen and lladdrlen must be done in 1348 * the caller. 1349 * 1350 * XXX If the link does not have link-layer adderss, what should 1351 * we do? (ifp->if_addrlen == 0) 1352 * Spec says nothing in sections for RA, RS and NA. There's small 1353 * description on it in NS section (RFC 2461 7.2.3). 1354 */ 1355 1356 ln = nd6_lookup(from, ifp, true); 1357 if (ln == NULL) { 1358 #if 0 1359 /* nothing must be done if there's no lladdr */ 1360 if (!lladdr || !lladdrlen) 1361 return NULL; 1362 #endif 1363 1364 ln = nd6_create(from, ifp); 1365 is_newentry = 1; 1366 } else { 1367 /* do nothing if static ndp is set */ 1368 if (ln->la_flags & LLE_STATIC) { 1369 LLE_WUNLOCK(ln); 1370 return; 1371 } 1372 is_newentry = 0; 1373 } 1374 1375 if (ln == NULL) 1376 return; 1377 1378 olladdr = (ln->la_flags & LLE_VALID) ? 1 : 0; 1379 if (olladdr && lladdr) { 1380 llchange = memcmp(lladdr, &ln->ll_addr, ifp->if_addrlen); 1381 } else 1382 llchange = 0; 1383 1384 /* 1385 * newentry olladdr lladdr llchange (*=record) 1386 * 0 n n -- (1) 1387 * 0 y n -- (2) 1388 * 0 n y -- (3) * STALE 1389 * 0 y y n (4) * 1390 * 0 y y y (5) * STALE 1391 * 1 -- n -- (6) NOSTATE(= PASSIVE) 1392 * 1 -- y -- (7) * STALE 1393 */ 1394 1395 if (lladdr) { /* (3-5) and (7) */ 1396 /* 1397 * Record source link-layer address 1398 * XXX is it dependent to ifp->if_type? 1399 */ 1400 memcpy(&ln->ll_addr, lladdr, ifp->if_addrlen); 1401 ln->la_flags |= LLE_VALID; 1402 } 1403 1404 if (!is_newentry) { 1405 if ((!olladdr && lladdr) || /* (3) */ 1406 (olladdr && lladdr && llchange)) { /* (5) */ 1407 do_update = 1; 1408 newstate = ND_LLINFO_STALE; 1409 } else /* (1-2,4) */ 1410 do_update = 0; 1411 } else { 1412 do_update = 1; 1413 if (lladdr == NULL) /* (6) */ 1414 newstate = ND_LLINFO_NOSTATE; 1415 else /* (7) */ 1416 newstate = ND_LLINFO_STALE; 1417 } 1418 1419 if (do_update) { 1420 /* 1421 * Update the state of the neighbor cache. 1422 */ 1423 ln->ln_state = newstate; 1424 1425 if (ln->ln_state == ND_LLINFO_STALE) { 1426 /* 1427 * XXX: since nd6_output() below will cause 1428 * state tansition to DELAY and reset the timer, 1429 * we must set the timer now, although it is actually 1430 * meaningless. 1431 */ 1432 nd_set_timer(ln, ND_TIMER_GC); 1433 1434 nd6_llinfo_release_pkts(ln, ifp); 1435 } else if (ln->ln_state == ND_LLINFO_INCOMPLETE) { 1436 /* probe right away */ 1437 nd_set_timer(ln, ND_TIMER_IMMEDIATE); 1438 } 1439 } 1440 1441 /* 1442 * ICMP6 type dependent behavior. 1443 * 1444 * NS: clear IsRouter if new entry 1445 * RS: clear IsRouter 1446 * RA: set IsRouter if there's lladdr 1447 * redir: clear IsRouter if new entry 1448 * 1449 * RA case, (1): 1450 * The spec says that we must set IsRouter in the following cases: 1451 * - If lladdr exist, set IsRouter. This means (1-5). 1452 * - If it is old entry (!newentry), set IsRouter. This means (7). 1453 * So, based on the spec, in (1-5) and (7) cases we must set IsRouter. 1454 * A question arises for (1) case. (1) case has no lladdr in the 1455 * neighbor cache, this is similar to (6). 1456 * This case is rare but we figured that we MUST NOT set IsRouter. 1457 * 1458 * newentry olladdr lladdr llchange NS RS RA redir 1459 * D R 1460 * 0 n n -- (1) c ? s 1461 * 0 y n -- (2) c s s 1462 * 0 n y -- (3) c s s 1463 * 0 y y n (4) c s s 1464 * 0 y y y (5) c s s 1465 * 1 -- n -- (6) c c c s 1466 * 1 -- y -- (7) c c s c s 1467 * 1468 * (c=clear s=set) 1469 */ 1470 switch (type & 0xff) { 1471 case ND_NEIGHBOR_SOLICIT: 1472 /* 1473 * New entry must have is_router flag cleared. 1474 */ 1475 if (is_newentry) /* (6-7) */ 1476 ln->ln_router = 0; 1477 break; 1478 case ND_REDIRECT: 1479 /* 1480 * If the icmp is a redirect to a better router, always set the 1481 * is_router flag. Otherwise, if the entry is newly created, 1482 * clear the flag. [RFC 2461, sec 8.3] 1483 */ 1484 if (code == ND_REDIRECT_ROUTER) 1485 ln->ln_router = 1; 1486 else if (is_newentry) /* (6-7) */ 1487 ln->ln_router = 0; 1488 break; 1489 case ND_ROUTER_SOLICIT: 1490 /* 1491 * is_router flag must always be cleared. 1492 */ 1493 ln->ln_router = 0; 1494 break; 1495 case ND_ROUTER_ADVERT: 1496 /* 1497 * Mark an entry with lladdr as a router. 1498 */ 1499 if ((!is_newentry && (olladdr || lladdr)) || /* (2-5) */ 1500 (is_newentry && lladdr)) { /* (7) */ 1501 ln->ln_router = 1; 1502 } 1503 break; 1504 } 1505 1506 if (do_update && lladdr != NULL) { 1507 struct sockaddr_in6 sin6; 1508 1509 sockaddr_in6_init(&sin6, from, 0, 0, 0); 1510 rt_clonedmsg(is_newentry ? RTM_ADD : RTM_CHANGE, 1511 NULL, sin6tosa(&sin6), lladdr, ifp); 1512 } 1513 1514 if (ln != NULL) 1515 LLE_WUNLOCK(ln); 1516 1517 /* 1518 * If we have too many cache entries, initiate immediate 1519 * purging for some entries. 1520 */ 1521 if (is_newentry) 1522 nd6_gc_neighbors(LLTABLE6(ifp), &ln->r_l3addr.addr6); 1523 } 1524 1525 static void 1526 nd6_slowtimo(void *ignored_arg) 1527 { 1528 struct nd_kifinfo *ndi; 1529 struct ifnet *ifp; 1530 struct psref psref; 1531 int s; 1532 1533 SOFTNET_KERNEL_LOCK_UNLESS_NET_MPSAFE(); 1534 callout_reset(&nd6_slowtimo_ch, ND6_SLOWTIMER_INTERVAL * hz, 1535 nd6_slowtimo, NULL); 1536 1537 s = pserialize_read_enter(); 1538 IFNET_READER_FOREACH(ifp) { 1539 ndi = ND_IFINFO(ifp); 1540 if (ndi->basereachable && /* already initialized */ 1541 (ndi->recalctm -= ND6_SLOWTIMER_INTERVAL) <= 0) { 1542 if_acquire(ifp, &psref); 1543 pserialize_read_exit(s); 1544 /* 1545 * Since reachable time rarely changes by router 1546 * advertisements, we SHOULD insure that a new random 1547 * value gets recomputed at least once every few hours. 1548 * (RFC 2461, 6.3.4) 1549 */ 1550 ndi->recalctm = nd6_recalc_reachtm_interval; 1551 ndi->reachable = ND_COMPUTE_RTIME(ndi->basereachable); 1552 s = pserialize_read_enter(); 1553 if_release(ifp, &psref); 1554 } 1555 } 1556 pserialize_read_exit(s); 1557 1558 SOFTNET_KERNEL_UNLOCK_UNLESS_NET_MPSAFE(); 1559 } 1560 1561 /* 1562 * Return 0 if a neighbor cache is found. Return EWOULDBLOCK if a cache is not 1563 * found and trying to resolve a neighbor; in this case the mbuf is queued in 1564 * the list. Otherwise return errno after freeing the mbuf. 1565 */ 1566 int 1567 nd6_resolve(struct ifnet *ifp, const struct rtentry *rt, struct mbuf *m, 1568 const struct sockaddr *_dst, uint8_t *lldst, size_t dstsize) 1569 { 1570 struct llentry *ln = NULL; 1571 bool created = false; 1572 const struct sockaddr_in6 *dst = satocsin6(_dst); 1573 int error; 1574 struct nd_kifinfo *ndi = ND_IFINFO(ifp); 1575 1576 /* discard the packet if IPv6 operation is disabled on the interface */ 1577 if (ndi->flags & ND6_IFF_IFDISABLED) { 1578 m_freem(m); 1579 return ENETDOWN; /* better error? */ 1580 } 1581 1582 /* 1583 * Address resolution or Neighbor Unreachability Detection 1584 * for the next hop. 1585 * At this point, the destination of the packet must be a unicast 1586 * or an anycast address(i.e. not a multicast). 1587 */ 1588 1589 /* Look up the neighbor cache for the nexthop */ 1590 ln = nd6_lookup(&dst->sin6_addr, ifp, false); 1591 1592 if (ln != NULL && (ln->la_flags & LLE_VALID) != 0 && 1593 /* Only STALE needs to go the slow path to change its state. */ 1594 (ln->ln_state == ND_LLINFO_REACHABLE || 1595 ln->ln_state == ND_LLINFO_DELAY || 1596 ln->ln_state == ND_LLINFO_PROBE)) { 1597 /* Fast path */ 1598 memcpy(lldst, &ln->ll_addr, MIN(dstsize, ifp->if_addrlen)); 1599 LLE_RUNLOCK(ln); 1600 return 0; 1601 } 1602 if (ln != NULL) 1603 LLE_RUNLOCK(ln); 1604 1605 /* Slow path */ 1606 ln = nd6_lookup(&dst->sin6_addr, ifp, true); 1607 if (ln == NULL && nd6_is_addr_neighbor(dst, ifp)) { 1608 /* 1609 * Since nd6_is_addr_neighbor() internally calls nd6_lookup(), 1610 * the condition below is not very efficient. But we believe 1611 * it is tolerable, because this should be a rare case. 1612 */ 1613 ln = nd6_create(&dst->sin6_addr, ifp); 1614 if (ln == NULL) { 1615 char ip6buf[INET6_ADDRSTRLEN]; 1616 log(LOG_DEBUG, 1617 "%s: can't allocate llinfo for %s " 1618 "(ln=%p, rt=%p)\n", __func__, 1619 IN6_PRINT(ip6buf, &dst->sin6_addr), ln, rt); 1620 m_freem(m); 1621 return ENOBUFS; 1622 } 1623 created = true; 1624 } 1625 1626 if (ln == NULL) { 1627 m_freem(m); 1628 return ENETDOWN; /* better error? */ 1629 } 1630 1631 error = nd_resolve(ln, rt, m, lldst, dstsize); 1632 1633 if (created) 1634 nd6_gc_neighbors(LLTABLE6(ifp), &dst->sin6_addr); 1635 1636 return error; 1637 } 1638 1639 int 1640 nd6_need_cache(struct ifnet *ifp) 1641 { 1642 /* 1643 * XXX: we currently do not make neighbor cache on any interface 1644 * other than ARCnet, Ethernet, and GIF. 1645 * 1646 * RFC2893 says: 1647 * - unidirectional tunnels needs no ND 1648 */ 1649 switch (ifp->if_type) { 1650 case IFT_ARCNET: 1651 case IFT_ETHER: 1652 case IFT_IEEE1394: 1653 case IFT_CARP: 1654 case IFT_GIF: /* XXX need more cases? */ 1655 case IFT_IPSEC: 1656 case IFT_PPP: 1657 case IFT_TUNNEL: 1658 return 1; 1659 default: 1660 return 0; 1661 } 1662 } 1663 1664 int 1665 nd6_sysctl( 1666 int name, 1667 void *oldp, /* syscall arg, need copyout */ 1668 size_t *oldlenp, 1669 void *newp, /* syscall arg, need copyin */ 1670 size_t newlen 1671 ) 1672 { 1673 int error; 1674 1675 if (newp) 1676 return EPERM; 1677 1678 switch (name) { 1679 1680 /* call the nd6 compat_90 hook to validate the nd6-related names */ 1681 case OICMPV6CTL_ND6_DRLIST: /* FALLTHROUGH */ 1682 case OICMPV6CTL_ND6_PRLIST: 1683 MODULE_HOOK_CALL(net_inet6_nd_90_hook, (name), ENOPROTOOPT, 1684 error); 1685 if (error == 0) 1686 *oldlenp = 0; 1687 return error; 1688 1689 case ICMPV6CTL_ND6_MAXQLEN: 1690 return 0; 1691 default: 1692 return ENOPROTOOPT; 1693 } 1694 } 1695
Indexes created Sat Sep 20 22:09:52 GMT 2025