nd6.c revision 1.274
1 /* $NetBSD: nd6.c,v 1.274 2020/09/15 10:05:36 roy 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 1.274 2020/09/15 10:05:36 roy 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 61 #include <net/if.h> 62 #include <net/if_dl.h> 63 #include <net/if_llatbl.h> 64 #include <net/if_types.h> 65 #include <net/nd.h> 66 #include <net/route.h> 67 #include <net/if_ether.h> 68 #include <net/if_arc.h> 69 70 #include <netinet/in.h> 71 #include <netinet6/in6_var.h> 72 #include <netinet/ip6.h> 73 #include <netinet6/ip6_var.h> 74 #include <netinet6/scope6_var.h> 75 #include <netinet6/nd6.h> 76 #include <netinet6/in6_ifattach.h> 77 #include <netinet/icmp6.h> 78 #include <netinet6/icmp6_private.h> 79 80 #ifdef COMPAT_90 81 #include <compat/netinet6/in6_var.h> 82 #include <compat/netinet6/nd6.h> 83 #endif 84 85 #define ND6_SLOWTIMER_INTERVAL (60 * 60) /* 1 hour */ 86 #define ND6_RECALC_REACHTM_INTERVAL (60 * 120) /* 2 hours */ 87 88 /* timer values */ 89 int nd6_prune = 1; /* walk list every 1 seconds */ 90 int nd6_useloopback = 1; /* use loopback interface for local traffic */ 91 92 /* preventing too many loops in ND option parsing */ 93 int nd6_maxndopt = 10; /* max # of ND options allowed */ 94 95 #ifdef ND6_DEBUG 96 int nd6_debug = 1; 97 #else 98 int nd6_debug = 0; 99 #endif 100 101 krwlock_t nd6_lock __cacheline_aligned; 102 103 int nd6_recalc_reachtm_interval = ND6_RECALC_REACHTM_INTERVAL; 104 105 static void nd6_slowtimo(void *); 106 static void nd6_free(struct llentry *, int); 107 static bool nd6_nud_enabled(struct ifnet *); 108 static unsigned int nd6_llinfo_reachable(struct ifnet *); 109 static unsigned int nd6_llinfo_retrans(struct ifnet *); 110 static union l3addr *nd6_llinfo_holdsrc(struct llentry *, union l3addr *); 111 static void nd6_llinfo_output(struct ifnet *, const union l3addr *, 112 const union l3addr *, const uint8_t *, const union l3addr *); 113 static void nd6_llinfo_missed(struct ifnet *, const union l3addr *, 114 int16_t, struct mbuf *); 115 static void nd6_timer(void *); 116 static void nd6_timer_work(struct work *, void *); 117 static struct nd_opt_hdr *nd6_option(union nd_opts *); 118 119 static callout_t nd6_slowtimo_ch; 120 static callout_t nd6_timer_ch; 121 static struct workqueue *nd6_timer_wq; 122 static struct work nd6_timer_wk; 123 124 struct nd_domain nd6_nd_domain = { 125 .nd_family = AF_INET6, 126 .nd_delay = 5, /* delay first probe time 5 second */ 127 .nd_mmaxtries = 3, /* maximum unicast query */ 128 .nd_umaxtries = 3, /* maximum multicast query */ 129 .nd_retransmultiple = BACKOFF_MULTIPLE, 130 .nd_maxretrans = MAX_RETRANS_TIMER, 131 .nd_maxnudhint = 0, /* max # of subsequent upper layer hints */ 132 .nd_maxqueuelen = 1, /* max # of packets in unresolved ND entries */ 133 .nd_nud_enabled = nd6_nud_enabled, 134 .nd_reachable = nd6_llinfo_reachable, 135 .nd_retrans = nd6_llinfo_retrans, 136 .nd_holdsrc = nd6_llinfo_holdsrc, 137 .nd_output = nd6_llinfo_output, 138 .nd_missed = nd6_llinfo_missed, 139 .nd_free = nd6_free, 140 }; 141 142 MALLOC_DEFINE(M_IP6NDP, "NDP", "IPv6 Neighbour Discovery"); 143 144 void 145 nd6_init(void) 146 { 147 int error; 148 149 nd_attach_domain(&nd6_nd_domain); 150 nd6_nbr_init(); 151 152 rw_init(&nd6_lock); 153 154 callout_init(&nd6_slowtimo_ch, CALLOUT_MPSAFE); 155 callout_init(&nd6_timer_ch, CALLOUT_MPSAFE); 156 157 error = workqueue_create(&nd6_timer_wq, "nd6_timer", 158 nd6_timer_work, NULL, PRI_SOFTNET, IPL_SOFTNET, WQ_MPSAFE); 159 if (error) 160 panic("%s: workqueue_create failed (%d)\n", __func__, error); 161 162 /* start timer */ 163 callout_reset(&nd6_slowtimo_ch, ND6_SLOWTIMER_INTERVAL * hz, 164 nd6_slowtimo, NULL); 165 callout_reset(&nd6_timer_ch, hz, nd6_timer, NULL); 166 } 167 168 struct nd_kifinfo * 169 nd6_ifattach(struct ifnet *ifp) 170 { 171 struct nd_kifinfo *nd; 172 173 nd = kmem_zalloc(sizeof(*nd), KM_SLEEP); 174 175 nd->chlim = IPV6_DEFHLIM; 176 nd->basereachable = REACHABLE_TIME; 177 nd->reachable = ND_COMPUTE_RTIME(nd->basereachable); 178 nd->retrans = RETRANS_TIMER; 179 180 nd->flags = ND6_IFF_PERFORMNUD; 181 182 /* A loopback interface always has ND6_IFF_AUTO_LINKLOCAL. 183 * A bridge interface should not have ND6_IFF_AUTO_LINKLOCAL 184 * because one of its members should. */ 185 if ((ip6_auto_linklocal && ifp->if_type != IFT_BRIDGE) || 186 (ifp->if_flags & IFF_LOOPBACK)) 187 nd->flags |= ND6_IFF_AUTO_LINKLOCAL; 188 189 return nd; 190 } 191 192 void 193 nd6_ifdetach(struct ifnet *ifp, struct in6_ifextra *ext) 194 { 195 196 /* Ensure all IPv6 addresses are purged before calling nd6_purge */ 197 if_purgeaddrs(ifp, AF_INET6, in6_purgeaddr); 198 nd6_purge(ifp, ext); 199 kmem_free(ext->nd_ifinfo, sizeof(struct nd_kifinfo)); 200 } 201 202 void 203 nd6_option_init(void *opt, int icmp6len, union nd_opts *ndopts) 204 { 205 206 memset(ndopts, 0, sizeof(*ndopts)); 207 ndopts->nd_opts_search = (struct nd_opt_hdr *)opt; 208 ndopts->nd_opts_last 209 = (struct nd_opt_hdr *)(((u_char *)opt) + icmp6len); 210 211 if (icmp6len == 0) { 212 ndopts->nd_opts_done = 1; 213 ndopts->nd_opts_search = NULL; 214 } 215 } 216 217 /* 218 * Take one ND option. 219 */ 220 static struct nd_opt_hdr * 221 nd6_option(union nd_opts *ndopts) 222 { 223 struct nd_opt_hdr *nd_opt; 224 int olen; 225 226 KASSERT(ndopts != NULL); 227 KASSERT(ndopts->nd_opts_last != NULL); 228 229 if (ndopts->nd_opts_search == NULL) 230 return NULL; 231 if (ndopts->nd_opts_done) 232 return NULL; 233 234 nd_opt = ndopts->nd_opts_search; 235 236 /* make sure nd_opt_len is inside the buffer */ 237 if ((void *)&nd_opt->nd_opt_len >= (void *)ndopts->nd_opts_last) { 238 memset(ndopts, 0, sizeof(*ndopts)); 239 return NULL; 240 } 241 242 olen = nd_opt->nd_opt_len << 3; 243 if (olen == 0) { 244 /* 245 * Message validation requires that all included 246 * options have a length that is greater than zero. 247 */ 248 memset(ndopts, 0, sizeof(*ndopts)); 249 return NULL; 250 } 251 252 ndopts->nd_opts_search = (struct nd_opt_hdr *)((char *)nd_opt + olen); 253 if (ndopts->nd_opts_search > ndopts->nd_opts_last) { 254 /* option overruns the end of buffer, invalid */ 255 memset(ndopts, 0, sizeof(*ndopts)); 256 return NULL; 257 } else if (ndopts->nd_opts_search == ndopts->nd_opts_last) { 258 /* reached the end of options chain */ 259 ndopts->nd_opts_done = 1; 260 ndopts->nd_opts_search = NULL; 261 } 262 return nd_opt; 263 } 264 265 /* 266 * Parse multiple ND options. 267 * This function is much easier to use, for ND routines that do not need 268 * multiple options of the same type. 269 */ 270 int 271 nd6_options(union nd_opts *ndopts) 272 { 273 struct nd_opt_hdr *nd_opt; 274 int i = 0; 275 276 KASSERT(ndopts != NULL); 277 KASSERT(ndopts->nd_opts_last != NULL); 278 279 if (ndopts->nd_opts_search == NULL) 280 return 0; 281 282 while (1) { 283 nd_opt = nd6_option(ndopts); 284 if (nd_opt == NULL && ndopts->nd_opts_last == NULL) { 285 /* 286 * Message validation requires that all included 287 * options have a length that is greater than zero. 288 */ 289 ICMP6_STATINC(ICMP6_STAT_ND_BADOPT); 290 memset(ndopts, 0, sizeof(*ndopts)); 291 return -1; 292 } 293 294 if (nd_opt == NULL) 295 goto skip1; 296 297 switch (nd_opt->nd_opt_type) { 298 case ND_OPT_SOURCE_LINKADDR: 299 case ND_OPT_TARGET_LINKADDR: 300 case ND_OPT_MTU: 301 case ND_OPT_REDIRECTED_HEADER: 302 case ND_OPT_NONCE: 303 if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) { 304 nd6log(LOG_INFO, 305 "duplicated ND6 option found (type=%d)\n", 306 nd_opt->nd_opt_type); 307 /* XXX bark? */ 308 } else { 309 ndopts->nd_opt_array[nd_opt->nd_opt_type] 310 = nd_opt; 311 } 312 break; 313 case ND_OPT_PREFIX_INFORMATION: 314 if (ndopts->nd_opt_array[nd_opt->nd_opt_type] == 0) { 315 ndopts->nd_opt_array[nd_opt->nd_opt_type] 316 = nd_opt; 317 } 318 ndopts->nd_opts_pi_end = 319 (struct nd_opt_prefix_info *)nd_opt; 320 break; 321 default: 322 /* 323 * Unknown options must be silently ignored, 324 * to accommodate future extension to the protocol. 325 */ 326 nd6log(LOG_DEBUG, 327 "nd6_options: unsupported option %d - " 328 "option ignored\n", nd_opt->nd_opt_type); 329 } 330 331 skip1: 332 i++; 333 if (i > nd6_maxndopt) { 334 ICMP6_STATINC(ICMP6_STAT_ND_TOOMANYOPT); 335 nd6log(LOG_INFO, "too many loop in nd opt\n"); 336 break; 337 } 338 339 if (ndopts->nd_opts_done) 340 break; 341 } 342 343 return 0; 344 } 345 346 /* 347 * Gets source address of the first packet in hold queue 348 * and stores it in @src. 349 * Returns pointer to @src (if hold queue is not empty) or NULL. 350 */ 351 static struct in6_addr * 352 nd6_llinfo_get_holdsrc(struct llentry *ln, struct in6_addr *src) 353 { 354 struct ip6_hdr *hip6; 355 356 if (ln == NULL || ln->ln_hold == NULL) 357 return NULL; 358 359 /* 360 * assuming every packet in ln_hold has the same IP header 361 */ 362 hip6 = mtod(ln->ln_hold, struct ip6_hdr *); 363 /* XXX pullup? */ 364 if (sizeof(*hip6) < ln->ln_hold->m_len) 365 *src = hip6->ip6_src; 366 else 367 src = NULL; 368 369 return src; 370 } 371 372 static union l3addr * 373 nd6_llinfo_holdsrc(struct llentry *ln, union l3addr *src) 374 { 375 376 if (nd6_llinfo_get_holdsrc(ln, &src->addr6) == NULL) 377 return NULL; 378 return src; 379 } 380 381 static void 382 nd6_llinfo_output(struct ifnet *ifp, const union l3addr *daddr, 383 const union l3addr *taddr, __unused const uint8_t *tlladdr, 384 const union l3addr *hsrc) 385 { 386 387 nd6_ns_output(ifp, &daddr->addr6, &taddr->addr6, 388 &hsrc->addr6, NULL); 389 } 390 391 static bool 392 nd6_nud_enabled(struct ifnet *ifp) 393 { 394 struct nd_kifinfo *ndi = ND_IFINFO(ifp); 395 396 return ndi->flags & ND6_IFF_PERFORMNUD; 397 } 398 399 static unsigned int 400 nd6_llinfo_reachable(struct ifnet *ifp) 401 { 402 struct nd_kifinfo *ndi = ND_IFINFO(ifp); 403 404 return ndi->reachable; 405 } 406 407 static unsigned int 408 nd6_llinfo_retrans(struct ifnet *ifp) 409 { 410 struct nd_kifinfo *ndi = ND_IFINFO(ifp); 411 412 return ndi->retrans; 413 } 414 415 static void 416 nd6_llinfo_missed(struct ifnet *ifp, const union l3addr *taddr, 417 int16_t type, struct mbuf *m) 418 { 419 struct in6_addr mdaddr6 = zeroin6_addr; 420 struct sockaddr_in6 dsin6, tsin6; 421 struct sockaddr *sa; 422 423 if (m != NULL) { 424 if (type == ND_LLINFO_PROBE) { 425 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 426 427 /* XXX pullup? */ 428 if (sizeof(*ip6) < m->m_len) 429 mdaddr6 = ip6->ip6_src; 430 m_freem(m); 431 } else 432 icmp6_error2(m, ICMP6_DST_UNREACH, 433 ICMP6_DST_UNREACH_ADDR, 0, ifp, &mdaddr6); 434 } 435 if (!IN6_IS_ADDR_UNSPECIFIED(&mdaddr6)) { 436 sockaddr_in6_init(&dsin6, &mdaddr6, 0, 0, 0); 437 sa = sin6tosa(&dsin6); 438 } else 439 sa = NULL; 440 441 sockaddr_in6_init(&tsin6, &taddr->addr6, 0, 0, 0); 442 rt_clonedmsg(RTM_MISS, sa, sin6tosa(&tsin6), NULL, ifp); 443 } 444 445 /* 446 * ND6 timer routine to expire default route list and prefix list 447 */ 448 static void 449 nd6_timer_work(struct work *wk, void *arg) 450 { 451 struct in6_ifaddr *ia6, *nia6; 452 int s, bound; 453 struct psref psref; 454 455 callout_reset(&nd6_timer_ch, nd6_prune * hz, 456 nd6_timer, NULL); 457 458 SOFTNET_KERNEL_LOCK_UNLESS_NET_MPSAFE(); 459 460 /* expire interface addresses */ 461 bound = curlwp_bind(); 462 s = pserialize_read_enter(); 463 for (ia6 = IN6_ADDRLIST_READER_FIRST(); ia6; ia6 = nia6) { 464 nia6 = IN6_ADDRLIST_READER_NEXT(ia6); 465 466 ia6_acquire(ia6, &psref); 467 pserialize_read_exit(s); 468 469 /* check address lifetime */ 470 if (IFA6_IS_INVALID(ia6)) { 471 struct ifnet *ifp; 472 473 ifp = ia6->ia_ifa.ifa_ifp; 474 IFNET_LOCK(ifp); 475 /* 476 * Need to take the lock first to prevent if_detach 477 * from running in6_purgeaddr concurrently. 478 */ 479 if (!if_is_deactivated(ifp)) { 480 ia6_release(ia6, &psref); 481 in6_purgeaddr(&ia6->ia_ifa); 482 } else { 483 /* 484 * ifp is being destroyed, ia6 will be destroyed 485 * by if_detach. 486 */ 487 ia6_release(ia6, &psref); 488 } 489 ia6 = NULL; 490 IFNET_UNLOCK(ifp); 491 } else if (IFA6_IS_DEPRECATED(ia6)) { 492 int oldflags = ia6->ia6_flags; 493 494 if ((oldflags & IN6_IFF_DEPRECATED) == 0) { 495 ia6->ia6_flags |= IN6_IFF_DEPRECATED; 496 rt_addrmsg(RTM_NEWADDR, (struct ifaddr *)ia6); 497 } 498 } else { 499 /* 500 * A new RA might have made a deprecated address 501 * preferred. 502 */ 503 if (ia6->ia6_flags & IN6_IFF_DEPRECATED) { 504 ia6->ia6_flags &= ~IN6_IFF_DEPRECATED; 505 rt_addrmsg(RTM_NEWADDR, (struct ifaddr *)ia6); 506 } 507 } 508 s = pserialize_read_enter(); 509 ia6_release(ia6, &psref); 510 } 511 pserialize_read_exit(s); 512 curlwp_bindx(bound); 513 514 SOFTNET_KERNEL_UNLOCK_UNLESS_NET_MPSAFE(); 515 } 516 517 static void 518 nd6_timer(void *ignored_arg) 519 { 520 521 workqueue_enqueue(nd6_timer_wq, &nd6_timer_wk, NULL); 522 } 523 524 /* 525 * Nuke neighbor cache/prefix/default router management table, right before 526 * ifp goes away. 527 */ 528 void 529 nd6_purge(struct ifnet *ifp, struct in6_ifextra *ext) 530 { 531 532 /* 533 * During detach, the ND info might be already removed, but 534 * then is explitly passed as argument. 535 * Otherwise get it from ifp->if_afdata. 536 */ 537 if (ext == NULL) 538 ext = ifp->if_afdata[AF_INET6]; 539 if (ext == NULL) 540 return; 541 542 /* 543 * We may not need to nuke the neighbor cache entries here 544 * because the neighbor cache is kept in if_afdata[AF_INET6]. 545 * nd6_purge() is invoked by in6_ifdetach() which is called 546 * from if_detach() where everything gets purged. However 547 * in6_ifdetach is directly called from vlan(4), so we still 548 * need to purge entries here. 549 */ 550 if (ext->lltable != NULL) 551 lltable_purge_entries(ext->lltable); 552 } 553 554 struct llentry * 555 nd6_lookup(const struct in6_addr *addr6, const struct ifnet *ifp, bool wlock) 556 { 557 struct sockaddr_in6 sin6; 558 struct llentry *ln; 559 560 sockaddr_in6_init(&sin6, addr6, 0, 0, 0); 561 562 IF_AFDATA_RLOCK(ifp); 563 ln = lla_lookup(LLTABLE6(ifp), wlock ? LLE_EXCLUSIVE : 0, 564 sin6tosa(&sin6)); 565 IF_AFDATA_RUNLOCK(ifp); 566 567 return ln; 568 } 569 570 struct llentry * 571 nd6_create(const struct in6_addr *addr6, const struct ifnet *ifp) 572 { 573 struct sockaddr_in6 sin6; 574 struct llentry *ln; 575 struct rtentry *rt; 576 577 sockaddr_in6_init(&sin6, addr6, 0, 0, 0); 578 rt = rtalloc1(sin6tosa(&sin6), 0); 579 580 IF_AFDATA_WLOCK(ifp); 581 ln = lla_create(LLTABLE6(ifp), LLE_EXCLUSIVE, sin6tosa(&sin6), rt); 582 IF_AFDATA_WUNLOCK(ifp); 583 584 if (rt != NULL) 585 rt_unref(rt); 586 if (ln != NULL) 587 ln->ln_state = ND_LLINFO_NOSTATE; 588 589 return ln; 590 } 591 592 /* 593 * Test whether a given IPv6 address is a neighbor or not, ignoring 594 * the actual neighbor cache. The neighbor cache is ignored in order 595 * to not reenter the routing code from within itself. 596 */ 597 static int 598 nd6_is_new_addr_neighbor(const struct sockaddr_in6 *addr, struct ifnet *ifp) 599 { 600 struct ifaddr *dstaddr; 601 int s; 602 603 /* 604 * A link-local address is always a neighbor. 605 * XXX: a link does not necessarily specify a single interface. 606 */ 607 if (IN6_IS_ADDR_LINKLOCAL(&addr->sin6_addr)) { 608 struct sockaddr_in6 sin6_copy; 609 u_int32_t zone; 610 611 /* 612 * We need sin6_copy since sa6_recoverscope() may modify the 613 * content (XXX). 614 */ 615 sin6_copy = *addr; 616 if (sa6_recoverscope(&sin6_copy)) 617 return 0; /* XXX: should be impossible */ 618 if (in6_setscope(&sin6_copy.sin6_addr, ifp, &zone)) 619 return 0; 620 if (sin6_copy.sin6_scope_id == zone) 621 return 1; 622 else 623 return 0; 624 } 625 626 /* 627 * If the address is assigned on the node of the other side of 628 * a p2p interface, the address should be a neighbor. 629 */ 630 s = pserialize_read_enter(); 631 dstaddr = ifa_ifwithdstaddr(sin6tocsa(addr)); 632 if (dstaddr != NULL) { 633 if (dstaddr->ifa_ifp == ifp) { 634 pserialize_read_exit(s); 635 return 1; 636 } 637 } 638 pserialize_read_exit(s); 639 640 return 0; 641 } 642 643 /* 644 * Detect if a given IPv6 address identifies a neighbor on a given link. 645 * XXX: should take care of the destination of a p2p link? 646 */ 647 int 648 nd6_is_addr_neighbor(const struct sockaddr_in6 *addr, struct ifnet *ifp) 649 { 650 struct llentry *ln; 651 struct rtentry *rt; 652 653 /* 654 * A link-local address is always a neighbor. 655 * XXX: a link does not necessarily specify a single interface. 656 */ 657 if (IN6_IS_ADDR_LINKLOCAL(&addr->sin6_addr)) { 658 struct sockaddr_in6 sin6_copy; 659 u_int32_t zone; 660 661 /* 662 * We need sin6_copy since sa6_recoverscope() may modify the 663 * content (XXX). 664 */ 665 sin6_copy = *addr; 666 if (sa6_recoverscope(&sin6_copy)) 667 return 0; /* XXX: should be impossible */ 668 if (in6_setscope(&sin6_copy.sin6_addr, ifp, &zone)) 669 return 0; 670 if (sin6_copy.sin6_scope_id == zone) 671 return 1; 672 else 673 return 0; 674 } 675 676 if (nd6_is_new_addr_neighbor(addr, ifp)) 677 return 1; 678 679 /* 680 * Even if the address matches none of our addresses, it might be 681 * in the neighbor cache or a connected route. 682 */ 683 ln = nd6_lookup(&addr->sin6_addr, ifp, false); 684 if (ln != NULL) { 685 LLE_RUNLOCK(ln); 686 return 1; 687 } 688 689 rt = rtalloc1(sin6tocsa(addr), 0); 690 if (rt == NULL) 691 return 0; 692 693 if ((rt->rt_flags & RTF_CONNECTED) && (rt->rt_ifp == ifp 694 #if NBRIDGE > 0 695 || rt->rt_ifp->if_bridge == ifp->if_bridge 696 #endif 697 #if NCARP > 0 698 || (ifp->if_type == IFT_CARP && rt->rt_ifp == ifp->if_carpdev) || 699 (rt->rt_ifp->if_type == IFT_CARP && rt->rt_ifp->if_carpdev == ifp)|| 700 (ifp->if_type == IFT_CARP && rt->rt_ifp->if_type == IFT_CARP && 701 rt->rt_ifp->if_carpdev == ifp->if_carpdev) 702 #endif 703 )) { 704 rt_unref(rt); 705 return 1; 706 } 707 rt_unref(rt); 708 709 return 0; 710 } 711 712 /* 713 * Free an nd6 llinfo entry. 714 * Since the function would cause significant changes in the kernel, DO NOT 715 * make it global, unless you have a strong reason for the change, and are sure 716 * that the change is safe. 717 */ 718 static void 719 nd6_free(struct llentry *ln, int gc) 720 { 721 struct ifnet *ifp; 722 723 KASSERT(ln != NULL); 724 LLE_WLOCK_ASSERT(ln); 725 726 /* 727 * If the reason for the deletion is just garbage collection, 728 * and the neighbor is an active router, do not delete it. 729 * Instead, reset the GC timer using the router's lifetime. 730 * XXX: the check for ln_state should be redundant, 731 * but we intentionally keep it just in case. 732 */ 733 if (!ip6_forwarding && ln->ln_router && 734 ln->ln_state == ND_LLINFO_STALE && gc) 735 { 736 nd_set_timer(ln, ND_TIMER_EXPIRE); 737 LLE_WUNLOCK(ln); 738 return; 739 } 740 741 ifp = ln->lle_tbl->llt_ifp; 742 743 if (ln->la_flags & LLE_VALID || gc) { 744 struct sockaddr_in6 sin6; 745 const char *lladdr; 746 747 sockaddr_in6_init(&sin6, &ln->r_l3addr.addr6, 0, 0, 0); 748 lladdr = ln->la_flags & LLE_VALID ? 749 (const char *)&ln->ll_addr : NULL; 750 rt_clonedmsg(RTM_DELETE, NULL, sin6tosa(&sin6), lladdr, ifp); 751 } 752 753 /* 754 * Save to unlock. We still hold an extra reference and will not 755 * free(9) in llentry_free() if someone else holds one as well. 756 */ 757 LLE_WUNLOCK(ln); 758 IF_AFDATA_LOCK(ifp); 759 LLE_WLOCK(ln); 760 761 lltable_free_entry(LLTABLE6(ifp), ln); 762 763 IF_AFDATA_UNLOCK(ifp); 764 } 765 766 /* 767 * Upper-layer reachability hint for Neighbor Unreachability Detection. 768 * 769 * XXX cost-effective methods? 770 */ 771 void 772 nd6_nud_hint(struct rtentry *rt) 773 { 774 struct llentry *ln; 775 struct ifnet *ifp; 776 777 if (rt == NULL) 778 return; 779 780 ifp = rt->rt_ifp; 781 ln = nd6_lookup(&(satocsin6(rt_getkey(rt)))->sin6_addr, ifp, true); 782 nd_nud_hint(ln); 783 } 784 785 struct gc_args { 786 int gc_entries; 787 const struct in6_addr *skip_in6; 788 }; 789 790 static int 791 nd6_purge_entry(struct lltable *llt, struct llentry *ln, void *farg) 792 { 793 struct gc_args *args = farg; 794 int *n = &args->gc_entries; 795 const struct in6_addr *skip_in6 = args->skip_in6; 796 797 if (*n <= 0) 798 return 0; 799 800 if (ND_IS_LLINFO_PERMANENT(ln)) 801 return 0; 802 803 if (IN6_ARE_ADDR_EQUAL(&ln->r_l3addr.addr6, skip_in6)) 804 return 0; 805 806 LLE_WLOCK(ln); 807 if (ln->ln_state > ND_LLINFO_INCOMPLETE) 808 ln->ln_state = ND_LLINFO_STALE; 809 else 810 ln->ln_state = ND_LLINFO_PURGE; 811 nd_set_timer(ln, ND_TIMER_IMMEDIATE); 812 LLE_WUNLOCK(ln); 813 814 (*n)--; 815 return 0; 816 } 817 818 static void 819 nd6_gc_neighbors(struct lltable *llt, const struct in6_addr *in6) 820 { 821 822 if (ip6_neighborgcthresh >= 0 && 823 lltable_get_entry_count(llt) >= ip6_neighborgcthresh) { 824 struct gc_args gc_args = {10, in6}; 825 /* 826 * XXX entries that are "less recently used" should be 827 * freed first. 828 */ 829 lltable_foreach_lle(llt, nd6_purge_entry, &gc_args); 830 } 831 } 832 833 void 834 nd6_rtrequest(int req, struct rtentry *rt, const struct rt_addrinfo *info) 835 { 836 struct sockaddr *gate = rt->rt_gateway; 837 struct ifnet *ifp = rt->rt_ifp; 838 uint8_t namelen = strlen(ifp->if_xname), addrlen = ifp->if_addrlen; 839 struct ifaddr *ifa; 840 841 RT_DPRINTF("rt_getkey(rt) = %p\n", rt_getkey(rt)); 842 843 if (req == RTM_LLINFO_UPD) { 844 int rc; 845 struct in6_addr *in6; 846 struct in6_addr in6_all; 847 int anycast; 848 849 if ((ifa = info->rti_ifa) == NULL) 850 return; 851 852 in6 = &ifatoia6(ifa)->ia_addr.sin6_addr; 853 anycast = ifatoia6(ifa)->ia6_flags & IN6_IFF_ANYCAST; 854 855 in6_all = in6addr_linklocal_allnodes; 856 if ((rc = in6_setscope(&in6_all, ifa->ifa_ifp, NULL)) != 0) { 857 log(LOG_ERR, "%s: failed to set scope %s " 858 "(errno=%d)\n", __func__, if_name(ifp), rc); 859 return; 860 } 861 862 /* XXX don't set Override for proxy addresses */ 863 nd6_na_output(ifa->ifa_ifp, &in6_all, in6, 864 (anycast ? 0 : ND_NA_FLAG_OVERRIDE) 865 #if 0 866 | (ip6_forwarding ? ND_NA_FLAG_ROUTER : 0) 867 #endif 868 , 1, NULL); 869 return; 870 } 871 872 if ((rt->rt_flags & RTF_GATEWAY) != 0) { 873 if (req != RTM_ADD) 874 return; 875 /* 876 * linklayers with particular MTU limitation. 877 */ 878 switch(ifp->if_type) { 879 #if NARCNET > 0 880 case IFT_ARCNET: 881 if (rt->rt_rmx.rmx_mtu > ARC_PHDS_MAXMTU) /* RFC2497 */ 882 rt->rt_rmx.rmx_mtu = ARC_PHDS_MAXMTU; 883 break; 884 #endif 885 } 886 return; 887 } 888 889 if (nd6_need_cache(ifp) == 0 && (rt->rt_flags & RTF_HOST) == 0) { 890 RT_DPRINTF("rt_getkey(rt) = %p\n", rt_getkey(rt)); 891 /* 892 * This is probably an interface direct route for a link 893 * which does not need neighbor caches (e.g. fe80::%lo0/64). 894 * We do not need special treatment below for such a route. 895 * Moreover, the RTF_LLINFO flag which would be set below 896 * would annoy the ndp(8) command. 897 */ 898 return; 899 } 900 901 switch (req) { 902 case RTM_ADD: { 903 struct psref psref; 904 905 RT_DPRINTF("rt_getkey(rt) = %p\n", rt_getkey(rt)); 906 /* 907 * There is no backward compatibility :) 908 * 909 * if ((rt->rt_flags & RTF_HOST) == 0 && 910 * SIN(rt_mask(rt))->sin_addr.s_addr != 0xffffffff) 911 * rt->rt_flags |= RTF_CLONING; 912 */ 913 /* XXX should move to route.c? */ 914 if (rt->rt_flags & (RTF_CONNECTED | RTF_LOCAL)) { 915 union { 916 struct sockaddr sa; 917 struct sockaddr_dl sdl; 918 struct sockaddr_storage ss; 919 } u; 920 /* 921 * Case 1: This route should come from a route to 922 * interface (RTF_CLONING case) or the route should be 923 * treated as on-link but is currently not 924 * (RTF_LLINFO && ln == NULL case). 925 */ 926 if (sockaddr_dl_init(&u.sdl, sizeof(u.ss), 927 ifp->if_index, ifp->if_type, 928 NULL, namelen, NULL, addrlen) == NULL) { 929 printf("%s.%d: sockaddr_dl_init(, %zu, ) " 930 "failed on %s\n", __func__, __LINE__, 931 sizeof(u.ss), if_name(ifp)); 932 } 933 rt_setgate(rt, &u.sa); 934 gate = rt->rt_gateway; 935 RT_DPRINTF("rt_getkey(rt) = %p\n", rt_getkey(rt)); 936 if (gate == NULL) { 937 log(LOG_ERR, 938 "%s: rt_setgate failed on %s\n", __func__, 939 if_name(ifp)); 940 break; 941 } 942 943 RT_DPRINTF("rt_getkey(rt) = %p\n", rt_getkey(rt)); 944 if ((rt->rt_flags & RTF_CONNECTED) != 0) 945 break; 946 } 947 RT_DPRINTF("rt_getkey(rt) = %p\n", rt_getkey(rt)); 948 /* 949 * In IPv4 code, we try to annonuce new RTF_ANNOUNCE entry here. 950 * We don't do that here since llinfo is not ready yet. 951 * 952 * There are also couple of other things to be discussed: 953 * - unsolicited NA code needs improvement beforehand 954 * - RFC2461 says we MAY send multicast unsolicited NA 955 * (7.2.6 paragraph 4), however, it also says that we 956 * SHOULD provide a mechanism to prevent multicast NA storm. 957 * we don't have anything like it right now. 958 * note that the mechanism needs a mutual agreement 959 * between proxies, which means that we need to implement 960 * a new protocol, or a new kludge. 961 * - from RFC2461 6.2.4, host MUST NOT send an unsolicited NA. 962 * we need to check ip6forwarding before sending it. 963 * (or should we allow proxy ND configuration only for 964 * routers? there's no mention about proxy ND from hosts) 965 */ 966 #if 0 967 /* XXX it does not work */ 968 if (rt->rt_flags & RTF_ANNOUNCE) 969 nd6_na_output(ifp, 970 &satocsin6(rt_getkey(rt))->sin6_addr, 971 &satocsin6(rt_getkey(rt))->sin6_addr, 972 ip6_forwarding ? ND_NA_FLAG_ROUTER : 0, 973 1, NULL); 974 #endif 975 976 if ((ifp->if_flags & (IFF_POINTOPOINT | IFF_LOOPBACK)) == 0) { 977 RT_DPRINTF("rt_getkey(rt) = %p\n", rt_getkey(rt)); 978 /* 979 * Address resolution isn't necessary for a point to 980 * point link, so we can skip this test for a p2p link. 981 */ 982 if (gate->sa_family != AF_LINK || 983 gate->sa_len < 984 sockaddr_dl_measure(namelen, addrlen)) { 985 log(LOG_DEBUG, 986 "nd6_rtrequest: bad gateway value: %s\n", 987 if_name(ifp)); 988 break; 989 } 990 satosdl(gate)->sdl_type = ifp->if_type; 991 satosdl(gate)->sdl_index = ifp->if_index; 992 RT_DPRINTF("rt_getkey(rt) = %p\n", rt_getkey(rt)); 993 } 994 RT_DPRINTF("rt_getkey(rt) = %p\n", rt_getkey(rt)); 995 996 /* 997 * When called from rt_ifa_addlocal, we cannot depend on that 998 * the address (rt_getkey(rt)) exits in the address list of the 999 * interface. So check RTF_LOCAL instead. 1000 */ 1001 if (rt->rt_flags & RTF_LOCAL) { 1002 if (nd6_useloopback) 1003 rt->rt_ifp = lo0ifp; /* XXX */ 1004 break; 1005 } 1006 1007 /* 1008 * check if rt_getkey(rt) is an address assigned 1009 * to the interface. 1010 */ 1011 ifa = (struct ifaddr *)in6ifa_ifpwithaddr_psref(ifp, 1012 &satocsin6(rt_getkey(rt))->sin6_addr, &psref); 1013 if (ifa != NULL) { 1014 if (nd6_useloopback) { 1015 rt->rt_ifp = lo0ifp; /* XXX */ 1016 /* 1017 * Make sure rt_ifa be equal to the ifaddr 1018 * corresponding to the address. 1019 * We need this because when we refer 1020 * rt_ifa->ia6_flags in ip6_input, we assume 1021 * that the rt_ifa points to the address instead 1022 * of the loopback address. 1023 */ 1024 if (!ISSET(info->rti_flags, RTF_DONTCHANGEIFA) 1025 && ifa != rt->rt_ifa) 1026 rt_replace_ifa(rt, ifa); 1027 } 1028 } else if (rt->rt_flags & RTF_ANNOUNCE) { 1029 /* join solicited node multicast for proxy ND */ 1030 if (ifp->if_flags & IFF_MULTICAST) { 1031 struct in6_addr llsol; 1032 int error; 1033 1034 llsol = satocsin6(rt_getkey(rt))->sin6_addr; 1035 llsol.s6_addr32[0] = htonl(0xff020000); 1036 llsol.s6_addr32[1] = 0; 1037 llsol.s6_addr32[2] = htonl(1); 1038 llsol.s6_addr8[12] = 0xff; 1039 if (in6_setscope(&llsol, ifp, NULL)) 1040 goto out; 1041 if (!in6_addmulti(&llsol, ifp, &error, 0)) { 1042 char ip6buf[INET6_ADDRSTRLEN]; 1043 nd6log(LOG_ERR, "%s: failed to join " 1044 "%s (errno=%d)\n", if_name(ifp), 1045 IN6_PRINT(ip6buf, &llsol), error); 1046 } 1047 } 1048 } 1049 out: 1050 ifa_release(ifa, &psref); 1051 /* 1052 * If we have too many cache entries, initiate immediate 1053 * purging for some entries. 1054 */ 1055 if (rt->rt_ifp != NULL) 1056 nd6_gc_neighbors(LLTABLE6(rt->rt_ifp), NULL); 1057 break; 1058 } 1059 1060 case RTM_DELETE: 1061 /* leave from solicited node multicast for proxy ND */ 1062 if ((rt->rt_flags & RTF_ANNOUNCE) != 0 && 1063 (ifp->if_flags & IFF_MULTICAST) != 0) { 1064 struct in6_addr llsol; 1065 1066 llsol = satocsin6(rt_getkey(rt))->sin6_addr; 1067 llsol.s6_addr32[0] = htonl(0xff020000); 1068 llsol.s6_addr32[1] = 0; 1069 llsol.s6_addr32[2] = htonl(1); 1070 llsol.s6_addr8[12] = 0xff; 1071 if (in6_setscope(&llsol, ifp, NULL) == 0) 1072 in6_lookup_and_delete_multi(&llsol, ifp); 1073 } 1074 break; 1075 } 1076 } 1077 1078 static void 1079 nd6_setifflags(struct ifnet *ifp, uint32_t flags) 1080 { 1081 struct nd_kifinfo *ndi = ND_IFINFO(ifp); 1082 struct ifaddr *ifa; 1083 struct in6_ifaddr *ia; 1084 int s; 1085 1086 if (ndi->flags & ND6_IFF_IFDISABLED && !(flags & ND6_IFF_IFDISABLED)) { 1087 /* 1088 * If the interface is marked as ND6_IFF_IFDISABLED and 1089 * has a link-local address with IN6_IFF_DUPLICATED, 1090 * do not clear ND6_IFF_IFDISABLED. 1091 * See RFC 4862, section 5.4.5. 1092 */ 1093 bool duplicated_linklocal = false; 1094 1095 s = pserialize_read_enter(); 1096 IFADDR_READER_FOREACH(ifa, ifp) { 1097 if (ifa->ifa_addr->sa_family != AF_INET6) 1098 continue; 1099 ia = (struct in6_ifaddr *)ifa; 1100 if ((ia->ia6_flags & IN6_IFF_DUPLICATED) && 1101 IN6_IS_ADDR_LINKLOCAL(IA6_IN6(ia))) 1102 { 1103 duplicated_linklocal = true; 1104 break; 1105 } 1106 } 1107 pserialize_read_exit(s); 1108 1109 if (duplicated_linklocal) { 1110 flags |= ND6_IFF_IFDISABLED; 1111 log(LOG_ERR, "%s: Cannot enable an interface" 1112 " with a link-local address marked" 1113 " duplicate.\n", if_name(ifp)); 1114 } else { 1115 ndi->flags &= ~ND6_IFF_IFDISABLED; 1116 if (ifp->if_flags & IFF_UP) 1117 in6_if_up(ifp); 1118 } 1119 } else if (!(ndi->flags & ND6_IFF_IFDISABLED) && 1120 (flags & ND6_IFF_IFDISABLED)) 1121 { 1122 struct psref psref; 1123 int bound = curlwp_bind(); 1124 1125 /* Mark all IPv6 addresses as tentative. */ 1126 1127 ndi->flags |= ND6_IFF_IFDISABLED; 1128 s = pserialize_read_enter(); 1129 IFADDR_READER_FOREACH(ifa, ifp) { 1130 if (ifa->ifa_addr->sa_family != AF_INET6) 1131 continue; 1132 ifa_acquire(ifa, &psref); 1133 pserialize_read_exit(s); 1134 1135 nd6_dad_stop(ifa); 1136 1137 ia = (struct in6_ifaddr *)ifa; 1138 ia->ia6_flags |= IN6_IFF_TENTATIVE; 1139 1140 s = pserialize_read_enter(); 1141 ifa_release(ifa, &psref); 1142 } 1143 pserialize_read_exit(s); 1144 curlwp_bindx(bound); 1145 } 1146 1147 if (flags & ND6_IFF_AUTO_LINKLOCAL) { 1148 if (!(ndi->flags & ND6_IFF_AUTO_LINKLOCAL)) { 1149 /* auto_linklocal 0->1 transition */ 1150 1151 ndi->flags |= ND6_IFF_AUTO_LINKLOCAL; 1152 in6_ifattach(ifp, NULL); 1153 } else if (!(flags & ND6_IFF_IFDISABLED) && 1154 ifp->if_flags & IFF_UP) 1155 { 1156 /* 1157 * When the IF already has 1158 * ND6_IFF_AUTO_LINKLOCAL, no link-local 1159 * address is assigned, and IFF_UP, try to 1160 * assign one. 1161 */ 1162 bool haslinklocal = 0; 1163 1164 s = pserialize_read_enter(); 1165 IFADDR_READER_FOREACH(ifa, ifp) { 1166 if (ifa->ifa_addr->sa_family !=AF_INET6) 1167 continue; 1168 ia = (struct in6_ifaddr *)ifa; 1169 if (IN6_IS_ADDR_LINKLOCAL(IA6_IN6(ia))){ 1170 haslinklocal = true; 1171 break; 1172 } 1173 } 1174 pserialize_read_exit(s); 1175 if (!haslinklocal) 1176 in6_ifattach(ifp, NULL); 1177 } 1178 } 1179 1180 ndi->flags = flags; 1181 } 1182 1183 int 1184 nd6_ioctl(u_long cmd, void *data, struct ifnet *ifp) 1185 { 1186 #ifdef OSIOCGIFINFO_IN6_90 1187 struct in6_ndireq90 *ondi = (struct in6_ndireq90 *)data; 1188 struct in6_ndifreq90 *ndif = (struct in6_ndifreq90 *)data; 1189 #define OND ondi->ndi 1190 #endif 1191 struct in6_ndireq *ndi = (struct in6_ndireq *)data; 1192 struct in6_nbrinfo *nbi = (struct in6_nbrinfo *)data; 1193 struct nd_kifinfo *ifndi = ND_IFINFO(ifp); 1194 int error = 0; 1195 #define ND ndi->ndi 1196 1197 switch (cmd) { 1198 #ifdef OSIOCSRTRFLUSH_IN6 1199 case OSIOCGDRLST_IN6: /* FALLTHROUGH */ 1200 case OSIOCGPRLST_IN6: /* FALLTHROUGH */ 1201 case OSIOCSNDFLUSH_IN6: /* FALLTHROUGH */ 1202 case OSIOCSPFXFLUSH_IN6: /* FALLTHROUGH */ 1203 case OSIOCSRTRFLUSH_IN6: /* FALLTHROUGH */ 1204 break; 1205 case OSIOCGDEFIFACE_IN6: 1206 ndif->ifindex = 0; 1207 break; 1208 case OSIOCSDEFIFACE_IN6: 1209 error = ENOTSUP; 1210 break; 1211 #endif 1212 #ifdef OSIOCGIFINFO_IN6 1213 case OSIOCGIFINFO_IN6: /* FALLTHROUGH */ 1214 #endif 1215 #ifdef OSIOCGIFINFO_IN6_90 1216 case OSIOCGIFINFO_IN6_90: 1217 memset(&OND, 0, sizeof(OND)); 1218 OND.initialized = 1; 1219 OND.chlim = ifndi->chlim; 1220 OND.basereachable = ifndi->basereachable; 1221 OND.retrans = ifndi->retrans; 1222 OND.flags = ifndi->flags; 1223 break; 1224 case OSIOCSIFINFO_IN6_90: 1225 /* Allow userland to set Neighour Unreachability Detection 1226 * timers. */ 1227 if (OND.chlim != 0) 1228 ifndi->chlim = OND.chlim; 1229 if (OND.basereachable != 0 && 1230 OND.basereachable != ifndi->basereachable) 1231 { 1232 ifndi->basereachable = OND.basereachable; 1233 ifndi->reachable = ND_COMPUTE_RTIME(OND.basereachable); 1234 } 1235 if (OND.retrans != 0) 1236 ifndi->retrans = OND.retrans; 1237 /* Retain the old behaviour .... */ 1238 /* FALLTHROUGH */ 1239 case OSIOCSIFINFO_FLAGS_90: 1240 nd6_setifflags(ifp, OND.flags); 1241 break; 1242 #undef OND 1243 #endif 1244 case SIOCGIFINFO_IN6: 1245 ND.chlim = ifndi->chlim; 1246 ND.basereachable = ifndi->basereachable; 1247 ND.retrans = ifndi->retrans; 1248 ND.flags = ifndi->flags; 1249 break; 1250 case SIOCSIFINFO_IN6: 1251 /* Allow userland to set Neighour Unreachability Detection 1252 * timers. */ 1253 if (ND.chlim != 0) 1254 ifndi->chlim = ND.chlim; 1255 if (ND.basereachable != 0 && 1256 ND.basereachable != ifndi->basereachable) 1257 { 1258 ifndi->basereachable = ND.basereachable; 1259 ifndi->reachable = ND_COMPUTE_RTIME(ND.basereachable); 1260 } 1261 if (ND.retrans != 0) 1262 ifndi->retrans = ND.retrans; 1263 break; 1264 case SIOCSIFINFO_FLAGS: 1265 nd6_setifflags(ifp, ND.flags); 1266 break; 1267 #undef ND 1268 case SIOCGNBRINFO_IN6: 1269 { 1270 struct llentry *ln; 1271 struct in6_addr nb_addr = nbi->addr; /* make local for safety */ 1272 1273 if ((error = in6_setscope(&nb_addr, ifp, NULL)) != 0) 1274 return error; 1275 1276 ln = nd6_lookup(&nb_addr, ifp, false); 1277 if (ln == NULL) { 1278 error = EINVAL; 1279 break; 1280 } 1281 nbi->state = ln->ln_state; 1282 nbi->asked = ln->ln_asked; 1283 nbi->isrouter = ln->ln_router; 1284 nbi->expire = ln->ln_expire ? 1285 time_mono_to_wall(ln->ln_expire) : 0; 1286 LLE_RUNLOCK(ln); 1287 1288 break; 1289 } 1290 } 1291 return error; 1292 } 1293 1294 void 1295 nd6_llinfo_release_pkts(struct llentry *ln, struct ifnet *ifp) 1296 { 1297 struct mbuf *m_hold, *m_hold_next; 1298 struct sockaddr_in6 sin6; 1299 1300 LLE_WLOCK_ASSERT(ln); 1301 1302 sockaddr_in6_init(&sin6, &ln->r_l3addr.addr6, 0, 0, 0); 1303 1304 m_hold = ln->la_hold, ln->la_hold = NULL, ln->la_numheld = 0; 1305 1306 LLE_WUNLOCK(ln); 1307 for (; m_hold != NULL; m_hold = m_hold_next) { 1308 m_hold_next = m_hold->m_nextpkt; 1309 m_hold->m_nextpkt = NULL; 1310 1311 /* 1312 * we assume ifp is not a p2p here, so 1313 * just set the 2nd argument as the 1314 * 1st one. 1315 */ 1316 ip6_if_output(ifp, ifp, m_hold, &sin6, NULL); 1317 } 1318 LLE_WLOCK(ln); 1319 } 1320 1321 /* 1322 * Create neighbor cache entry and cache link-layer address, 1323 * on reception of inbound ND6 packets. (RS/RA/NS/redirect) 1324 */ 1325 void 1326 nd6_cache_lladdr( 1327 struct ifnet *ifp, 1328 struct in6_addr *from, 1329 char *lladdr, 1330 int lladdrlen, 1331 int type, /* ICMP6 type */ 1332 int code /* type dependent information */ 1333 ) 1334 { 1335 struct llentry *ln = NULL; 1336 int is_newentry; 1337 int do_update; 1338 int olladdr; 1339 int llchange; 1340 int newstate = 0; 1341 1342 KASSERT(ifp != NULL); 1343 KASSERT(from != NULL); 1344 1345 /* nothing must be updated for unspecified address */ 1346 if (IN6_IS_ADDR_UNSPECIFIED(from)) 1347 return; 1348 1349 /* 1350 * Validation about ifp->if_addrlen and lladdrlen must be done in 1351 * the caller. 1352 * 1353 * XXX If the link does not have link-layer adderss, what should 1354 * we do? (ifp->if_addrlen == 0) 1355 * Spec says nothing in sections for RA, RS and NA. There's small 1356 * description on it in NS section (RFC 2461 7.2.3). 1357 */ 1358 1359 ln = nd6_lookup(from, ifp, true); 1360 if (ln == NULL) { 1361 #if 0 1362 /* nothing must be done if there's no lladdr */ 1363 if (!lladdr || !lladdrlen) 1364 return NULL; 1365 #endif 1366 1367 ln = nd6_create(from, ifp); 1368 is_newentry = 1; 1369 } else { 1370 /* do nothing if static ndp is set */ 1371 if (ln->la_flags & LLE_STATIC) { 1372 LLE_WUNLOCK(ln); 1373 return; 1374 } 1375 is_newentry = 0; 1376 } 1377 1378 if (ln == NULL) 1379 return; 1380 1381 olladdr = (ln->la_flags & LLE_VALID) ? 1 : 0; 1382 if (olladdr && lladdr) { 1383 llchange = memcmp(lladdr, &ln->ll_addr, ifp->if_addrlen); 1384 } else 1385 llchange = 0; 1386 1387 /* 1388 * newentry olladdr lladdr llchange (*=record) 1389 * 0 n n -- (1) 1390 * 0 y n -- (2) 1391 * 0 n y -- (3) * STALE 1392 * 0 y y n (4) * 1393 * 0 y y y (5) * STALE 1394 * 1 -- n -- (6) NOSTATE(= PASSIVE) 1395 * 1 -- y -- (7) * STALE 1396 */ 1397 1398 if (lladdr) { /* (3-5) and (7) */ 1399 /* 1400 * Record source link-layer address 1401 * XXX is it dependent to ifp->if_type? 1402 */ 1403 memcpy(&ln->ll_addr, lladdr, ifp->if_addrlen); 1404 ln->la_flags |= LLE_VALID; 1405 } 1406 1407 if (!is_newentry) { 1408 if ((!olladdr && lladdr) || /* (3) */ 1409 (olladdr && lladdr && llchange)) { /* (5) */ 1410 do_update = 1; 1411 newstate = ND_LLINFO_STALE; 1412 } else /* (1-2,4) */ 1413 do_update = 0; 1414 } else { 1415 do_update = 1; 1416 if (lladdr == NULL) /* (6) */ 1417 newstate = ND_LLINFO_NOSTATE; 1418 else /* (7) */ 1419 newstate = ND_LLINFO_STALE; 1420 } 1421 1422 if (do_update) { 1423 /* 1424 * Update the state of the neighbor cache. 1425 */ 1426 ln->ln_state = newstate; 1427 1428 if (ln->ln_state == ND_LLINFO_STALE) { 1429 /* 1430 * XXX: since nd6_output() below will cause 1431 * state tansition to DELAY and reset the timer, 1432 * we must set the timer now, although it is actually 1433 * meaningless. 1434 */ 1435 nd_set_timer(ln, ND_TIMER_GC); 1436 1437 nd6_llinfo_release_pkts(ln, ifp); 1438 } else if (ln->ln_state == ND_LLINFO_INCOMPLETE) { 1439 /* probe right away */ 1440 nd_set_timer(ln, ND_TIMER_IMMEDIATE); 1441 } 1442 } 1443 1444 /* 1445 * ICMP6 type dependent behavior. 1446 * 1447 * NS: clear IsRouter if new entry 1448 * RS: clear IsRouter 1449 * RA: set IsRouter if there's lladdr 1450 * redir: clear IsRouter if new entry 1451 * 1452 * RA case, (1): 1453 * The spec says that we must set IsRouter in the following cases: 1454 * - If lladdr exist, set IsRouter. This means (1-5). 1455 * - If it is old entry (!newentry), set IsRouter. This means (7). 1456 * So, based on the spec, in (1-5) and (7) cases we must set IsRouter. 1457 * A quetion arises for (1) case. (1) case has no lladdr in the 1458 * neighbor cache, this is similar to (6). 1459 * This case is rare but we figured that we MUST NOT set IsRouter. 1460 * 1461 * newentry olladdr lladdr llchange NS RS RA redir 1462 * D R 1463 * 0 n n -- (1) c ? s 1464 * 0 y n -- (2) c s s 1465 * 0 n y -- (3) c s s 1466 * 0 y y n (4) c s s 1467 * 0 y y y (5) c s s 1468 * 1 -- n -- (6) c c c s 1469 * 1 -- y -- (7) c c s c s 1470 * 1471 * (c=clear s=set) 1472 */ 1473 switch (type & 0xff) { 1474 case ND_NEIGHBOR_SOLICIT: 1475 /* 1476 * New entry must have is_router flag cleared. 1477 */ 1478 if (is_newentry) /* (6-7) */ 1479 ln->ln_router = 0; 1480 break; 1481 case ND_REDIRECT: 1482 /* 1483 * If the icmp is a redirect to a better router, always set the 1484 * is_router flag. Otherwise, if the entry is newly created, 1485 * clear the flag. [RFC 2461, sec 8.3] 1486 */ 1487 if (code == ND_REDIRECT_ROUTER) 1488 ln->ln_router = 1; 1489 else if (is_newentry) /* (6-7) */ 1490 ln->ln_router = 0; 1491 break; 1492 case ND_ROUTER_SOLICIT: 1493 /* 1494 * is_router flag must always be cleared. 1495 */ 1496 ln->ln_router = 0; 1497 break; 1498 case ND_ROUTER_ADVERT: 1499 /* 1500 * Mark an entry with lladdr as a router. 1501 */ 1502 if ((!is_newentry && (olladdr || lladdr)) || /* (2-5) */ 1503 (is_newentry && lladdr)) { /* (7) */ 1504 ln->ln_router = 1; 1505 } 1506 break; 1507 } 1508 1509 if (do_update && lladdr != NULL) { 1510 struct sockaddr_in6 sin6; 1511 1512 sockaddr_in6_init(&sin6, from, 0, 0, 0); 1513 rt_clonedmsg(is_newentry ? RTM_ADD : RTM_CHANGE, 1514 NULL, sin6tosa(&sin6), lladdr, ifp); 1515 } 1516 1517 if (ln != NULL) 1518 LLE_WUNLOCK(ln); 1519 1520 /* 1521 * If we have too many cache entries, initiate immediate 1522 * purging for some entries. 1523 */ 1524 if (is_newentry) 1525 nd6_gc_neighbors(LLTABLE6(ifp), &ln->r_l3addr.addr6); 1526 } 1527 1528 static void 1529 nd6_slowtimo(void *ignored_arg) 1530 { 1531 struct nd_kifinfo *ndi; 1532 struct ifnet *ifp; 1533 int s; 1534 1535 SOFTNET_KERNEL_LOCK_UNLESS_NET_MPSAFE(); 1536 callout_reset(&nd6_slowtimo_ch, ND6_SLOWTIMER_INTERVAL * hz, 1537 nd6_slowtimo, NULL); 1538 1539 s = pserialize_read_enter(); 1540 IFNET_READER_FOREACH(ifp) { 1541 ndi = ND_IFINFO(ifp); 1542 if (ndi->basereachable && /* already initialized */ 1543 (ndi->recalctm -= ND6_SLOWTIMER_INTERVAL) <= 0) { 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 } 1553 } 1554 pserialize_read_exit(s); 1555 1556 SOFTNET_KERNEL_UNLOCK_UNLESS_NET_MPSAFE(); 1557 } 1558 1559 /* 1560 * Return 0 if a neighbor cache is found. Return EWOULDBLOCK if a cache is not 1561 * found and trying to resolve a neighbor; in this case the mbuf is queued in 1562 * the list. Otherwise return errno after freeing the mbuf. 1563 */ 1564 int 1565 nd6_resolve(struct ifnet *ifp, const struct rtentry *rt, struct mbuf *m, 1566 const struct sockaddr *_dst, uint8_t *lldst, size_t dstsize) 1567 { 1568 struct llentry *ln = NULL; 1569 bool created = false; 1570 const struct sockaddr_in6 *dst = satocsin6(_dst); 1571 int error; 1572 struct nd_kifinfo *ndi = ND_IFINFO(ifp); 1573 1574 /* discard the packet if IPv6 operation is disabled on the interface */ 1575 if (ndi->flags & ND6_IFF_IFDISABLED) { 1576 m_freem(m); 1577 return ENETDOWN; /* better error? */ 1578 } 1579 1580 /* 1581 * Address resolution or Neighbor Unreachability Detection 1582 * for the next hop. 1583 * At this point, the destination of the packet must be a unicast 1584 * or an anycast address(i.e. not a multicast). 1585 */ 1586 1587 /* Look up the neighbor cache for the nexthop */ 1588 ln = nd6_lookup(&dst->sin6_addr, ifp, false); 1589 1590 if (ln != NULL && (ln->la_flags & LLE_VALID) != 0 && 1591 ln->ln_state == ND_LLINFO_REACHABLE) { 1592 /* Fast path */ 1593 memcpy(lldst, &ln->ll_addr, MIN(dstsize, ifp->if_addrlen)); 1594 LLE_RUNLOCK(ln); 1595 return 0; 1596 } 1597 if (ln != NULL) 1598 LLE_RUNLOCK(ln); 1599 1600 /* Slow path */ 1601 ln = nd6_lookup(&dst->sin6_addr, ifp, true); 1602 if (ln == NULL && nd6_is_addr_neighbor(dst, ifp)) { 1603 /* 1604 * Since nd6_is_addr_neighbor() internally calls nd6_lookup(), 1605 * the condition below is not very efficient. But we believe 1606 * it is tolerable, because this should be a rare case. 1607 */ 1608 ln = nd6_create(&dst->sin6_addr, ifp); 1609 if (ln == NULL) { 1610 char ip6buf[INET6_ADDRSTRLEN]; 1611 log(LOG_DEBUG, 1612 "%s: can't allocate llinfo for %s " 1613 "(ln=%p, rt=%p)\n", __func__, 1614 IN6_PRINT(ip6buf, &dst->sin6_addr), ln, rt); 1615 m_freem(m); 1616 return ENOBUFS; 1617 } 1618 created = true; 1619 } 1620 1621 if (ln == NULL) { 1622 m_freem(m); 1623 return ENETDOWN; /* better error? */ 1624 } 1625 1626 error = nd_resolve(ln, rt, m, lldst, dstsize); 1627 1628 if (created) 1629 nd6_gc_neighbors(LLTABLE6(ifp), &dst->sin6_addr); 1630 1631 return error; 1632 } 1633 1634 int 1635 nd6_need_cache(struct ifnet *ifp) 1636 { 1637 /* 1638 * XXX: we currently do not make neighbor cache on any interface 1639 * other than ARCnet, Ethernet, and GIF. 1640 * 1641 * RFC2893 says: 1642 * - unidirectional tunnels needs no ND 1643 */ 1644 switch (ifp->if_type) { 1645 case IFT_ARCNET: 1646 case IFT_ETHER: 1647 case IFT_IEEE1394: 1648 case IFT_CARP: 1649 case IFT_GIF: /* XXX need more cases? */ 1650 case IFT_PPP: 1651 case IFT_TUNNEL: 1652 return 1; 1653 default: 1654 return 0; 1655 } 1656 } 1657 1658 int 1659 nd6_sysctl( 1660 int name, 1661 void *oldp, /* syscall arg, need copyout */ 1662 size_t *oldlenp, 1663 void *newp, /* syscall arg, need copyin */ 1664 size_t newlen 1665 ) 1666 { 1667 1668 if (newp) 1669 return EPERM; 1670 1671 switch (name) { 1672 #ifdef COMPAT_90 1673 case OICMPV6CTL_ND6_DRLIST: /* FALLTHROUGH */ 1674 case OICMPV6CTL_ND6_PRLIST: 1675 *oldlenp = 0; 1676 return 0; 1677 #endif 1678 case ICMPV6CTL_ND6_MAXQLEN: 1679 return 0; 1680 default: 1681 return ENOPROTOOPT; 1682 } 1683 } 1684
Indexes created Mon Sep 22 13:09:51 GMT 2025