1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the project nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * $KAME: nd6_nbr.c,v 1.86 2002/01/21 02:33:04 jinmei Exp $ 32 */ 33 34 #include "opt_inet.h" 35 #include "opt_inet6.h" 36 #include "opt_ipsec.h" 37 38 #include <sys/param.h> 39 #include <sys/systm.h> 40 #include <sys/counter.h> 41 #include <sys/eventhandler.h> 42 #include <sys/malloc.h> 43 #include <sys/libkern.h> 44 #include <sys/lock.h> 45 #include <sys/rwlock.h> 46 #include <sys/mbuf.h> 47 #include <sys/socket.h> 48 #include <sys/sockio.h> 49 #include <sys/time.h> 50 #include <sys/kernel.h> 51 #include <sys/errno.h> 52 #include <sys/sysctl.h> 53 #include <sys/syslog.h> 54 #include <sys/queue.h> 55 #include <sys/callout.h> 56 #include <sys/refcount.h> 57 58 #include <net/if.h> 59 #include <net/if_types.h> 60 #include <net/if_dl.h> 61 #include <net/if_var.h> 62 #include <net/if_private.h> 63 #include <net/route.h> 64 #include <net/vnet.h> 65 66 #include <netinet/in.h> 67 #include <netinet/in_var.h> 68 #include <net/if_llatbl.h> 69 #include <netinet6/in6_var.h> 70 #include <netinet6/in6_ifattach.h> 71 #include <netinet/ip6.h> 72 #include <netinet6/ip6_var.h> 73 #include <netinet6/scope6_var.h> 74 #include <netinet6/nd6.h> 75 #include <netinet/icmp6.h> 76 #include <netinet/ip_carp.h> 77 #include <netinet6/send.h> 78 79 #include <machine/atomic.h> 80 81 #define SDL(s) ((struct sockaddr_dl *)s) 82 83 MALLOC_DECLARE(M_IP6NDP); 84 85 struct dadq; 86 static struct dadq *nd6_dad_find(struct ifaddr *, struct nd_opt_nonce *); 87 static void nd6_dad_add(struct dadq *dp); 88 static void nd6_dad_del(struct dadq *dp); 89 static void nd6_dad_rele(struct dadq *); 90 static void nd6_dad_starttimer(struct dadq *, int); 91 static void nd6_dad_stoptimer(struct dadq *); 92 static void nd6_dad_timer(void *); 93 static void nd6_dad_duplicated(struct ifaddr *, struct dadq *); 94 static void nd6_dad_ns_output(struct dadq *); 95 static void nd6_dad_ns_input(struct ifaddr *, struct nd_opt_nonce *); 96 static void nd6_dad_na_input(struct ifaddr *); 97 static void nd6_na_output_fib(struct ifnet *, const struct in6_addr *, 98 const struct in6_addr *, u_long, int, struct sockaddr *, u_int); 99 static void nd6_ns_output_fib(struct ifnet *, const struct in6_addr *, 100 const struct in6_addr *, const struct in6_addr *, uint8_t *, u_int); 101 static void nd6_queue_add(struct ifaddr *, struct in6_addr *, 102 struct in6_addr *, struct sockaddr_dl *, int, uint32_t); 103 104 static struct ifaddr *nd6_proxy_fill_sdl(struct ifnet *, 105 const struct in6_addr *, struct sockaddr_dl *); 106 107 VNET_DEFINE_STATIC(int, dad_enhanced) = 1; 108 #define V_dad_enhanced VNET(dad_enhanced) 109 110 SYSCTL_DECL(_net_inet6_ip6); 111 SYSCTL_INT(_net_inet6_ip6, OID_AUTO, dad_enhanced, CTLFLAG_VNET | CTLFLAG_RW, 112 &VNET_NAME(dad_enhanced), 0, 113 "Enable Enhanced DAD, which adds a random nonce to NS messages for DAD."); 114 115 VNET_DEFINE_STATIC(int, dad_maxtry) = 15; /* max # of *tries* to 116 transmit DAD packet */ 117 #define V_dad_maxtry VNET(dad_maxtry) 118 119 VNET_DEFINE_STATIC(int, nd6_onlink_ns_rfc4861) = 0; 120 #define V_nd6_onlink_ns_rfc4861 VNET(nd6_onlink_ns_rfc4861) 121 SYSCTL_INT(_net_inet6_icmp6, ICMPV6CTL_ND6_ONLINKNSRFC4861, 122 nd6_onlink_ns_rfc4861, CTLFLAG_VNET | CTLFLAG_RW, 123 &VNET_NAME(nd6_onlink_ns_rfc4861), 0, 124 "Accept 'on-link' ICMPv6 NS messages in compliance with RFC 4861"); 125 126 struct nd_queue { 127 TAILQ_ENTRY(nd_queue) ndq_list; 128 struct ifaddr *ndq_ifa; 129 struct in6_addr ndq_daddr; 130 struct in6_addr ndq_taddr; 131 struct sockaddr_dl ndq_sdl; 132 uint32_t ndq_flags; 133 struct callout ndq_callout; 134 }; 135 136 /* 137 * Input a Neighbor Solicitation Message. 138 * 139 * Based on RFC 2461 140 * Based on RFC 2462 (duplicate address detection) 141 */ 142 void 143 nd6_ns_input(struct mbuf *m, int off, int icmp6len) 144 { 145 struct ifnet *ifp; 146 struct ip6_hdr *ip6; 147 struct nd_neighbor_solicit *nd_ns; 148 struct in6_addr daddr6, myaddr6, saddr6, taddr6; 149 struct ifaddr *ifa; 150 struct sockaddr_dl proxydl; 151 union nd_opts ndopts; 152 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 153 char *lladdr; 154 int lladdrlen, rflag, tentative, tlladdr; 155 uint32_t dflags; 156 157 ifa = NULL; 158 159 /* RFC 6980: Nodes MUST silently ignore fragments */ 160 if(m->m_flags & M_FRAGMENTED) 161 goto freeit; 162 163 ifp = m->m_pkthdr.rcvif; 164 ip6 = mtod(m, struct ip6_hdr *); 165 if (__predict_false(ip6->ip6_hlim != 255)) { 166 ICMP6STAT_INC(icp6s_invlhlim); 167 nd6log((LOG_ERR, 168 "nd6_ns_input: invalid hlim (%d) from %s to %s on %s\n", 169 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src), 170 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp))); 171 goto bads; 172 } 173 174 if (m->m_len < off + icmp6len) { 175 m = m_pullup(m, off + icmp6len); 176 if (m == NULL) { 177 IP6STAT_INC(ip6s_exthdrtoolong); 178 return; 179 } 180 } 181 ip6 = mtod(m, struct ip6_hdr *); 182 nd_ns = (struct nd_neighbor_solicit *)((caddr_t)ip6 + off); 183 184 saddr6 = ip6->ip6_src; 185 daddr6 = ip6->ip6_dst; 186 taddr6 = nd_ns->nd_ns_target; 187 if (in6_setscope(&taddr6, ifp, NULL) != 0) 188 goto bad; 189 190 rflag = (V_ip6_forwarding) ? ND_NA_FLAG_ROUTER : 0; 191 if (ifp->if_inet6->nd_flags & ND6_IFF_ACCEPT_RTADV && V_ip6_norbit_raif) 192 rflag = 0; 193 194 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) { 195 /* dst has to be a solicited node multicast address. */ 196 if (daddr6.s6_addr16[0] == IPV6_ADDR_INT16_MLL && 197 /* don't check ifindex portion */ 198 daddr6.s6_addr32[1] == 0 && 199 daddr6.s6_addr32[2] == IPV6_ADDR_INT32_ONE && 200 daddr6.s6_addr8[12] == 0xff) { 201 ; /* good */ 202 } else { 203 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet " 204 "(wrong ip6 dst)\n")); 205 goto bad; 206 } 207 } else if (!V_nd6_onlink_ns_rfc4861) { 208 struct sockaddr_in6 src_sa6; 209 210 /* 211 * According to recent IETF discussions, it is not a good idea 212 * to accept a NS from an address which would not be deemed 213 * to be a neighbor otherwise. This point is expected to be 214 * clarified in future revisions of the specification. 215 */ 216 bzero(&src_sa6, sizeof(src_sa6)); 217 src_sa6.sin6_family = AF_INET6; 218 src_sa6.sin6_len = sizeof(src_sa6); 219 src_sa6.sin6_addr = saddr6; 220 if (nd6_is_addr_neighbor(&src_sa6, ifp) == 0) { 221 nd6log((LOG_INFO, "nd6_ns_input: " 222 "NS packet from non-neighbor\n")); 223 goto bad; 224 } 225 } 226 227 if (IN6_IS_ADDR_MULTICAST(&taddr6)) { 228 nd6log((LOG_INFO, "nd6_ns_input: bad NS target (multicast)\n")); 229 goto bad; 230 } 231 232 icmp6len -= sizeof(*nd_ns); 233 nd6_option_init(nd_ns + 1, icmp6len, &ndopts); 234 if (nd6_options(&ndopts) < 0) { 235 nd6log((LOG_INFO, 236 "nd6_ns_input: invalid ND option, ignored\n")); 237 /* nd6_options have incremented stats */ 238 goto freeit; 239 } 240 241 lladdr = NULL; 242 lladdrlen = 0; 243 if (ndopts.nd_opts_src_lladdr) { 244 lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1); 245 lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3; 246 } 247 248 if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) && lladdr) { 249 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet " 250 "(link-layer address option)\n")); 251 goto bad; 252 } 253 254 /* 255 * Attaching target link-layer address to the NA? 256 * (RFC 2461 7.2.4) 257 * 258 * NS IP dst is unicast/anycast MUST NOT add 259 * NS IP dst is solicited-node multicast MUST add 260 * 261 * In implementation, we add target link-layer address by default. 262 * We do not add one in MUST NOT cases. 263 */ 264 tlladdr = 0; 265 if (IN6_IS_ADDR_MULTICAST(&daddr6)) 266 tlladdr |= ND6_NA_OPT_LLA; 267 268 /* 269 * Target address (taddr6) must be either: 270 * (1) Valid unicast/anycast address for my receiving interface, 271 * (2) Unicast address for which I'm offering proxy service, or 272 * (3) "tentative" address on which DAD is being performed. 273 */ 274 /* (1) and (3) check. */ 275 if (ifp->if_carp) { 276 ifa = (*carp_iamatch6_p)(ifp, &taddr6); 277 if (ifa != NULL) 278 tlladdr |= ND6_NA_CARP_MASTER; 279 } else 280 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6); 281 282 /* (2) check. */ 283 dflags = 0; 284 if (ifa == NULL) { 285 if ((ifa = nd6_proxy_fill_sdl(ifp, &taddr6, &proxydl)) != NULL) 286 dflags |= ND6_QUEUE_FLAG_PROXY; 287 } 288 if (ifa == NULL) { 289 /* 290 * We've got an NS packet, and we don't have that address 291 * assigned for us. We MUST silently ignore it. 292 * See RFC2461 7.2.3. 293 */ 294 goto freeit; 295 } 296 if ((((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST) != 0) 297 dflags |= ND6_QUEUE_FLAG_ANYCAST; 298 myaddr6 = *IFA_IN6(ifa); 299 tentative = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE; 300 if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DUPLICATED) 301 goto freeit; 302 303 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 304 nd6log((LOG_INFO, "nd6_ns_input: lladdrlen mismatch for %s " 305 "(if %d, NS packet %d)\n", 306 ip6_sprintf(ip6bufs, &taddr6), 307 ifp->if_addrlen, lladdrlen - 2)); 308 goto bad; 309 } 310 311 if (IN6_ARE_ADDR_EQUAL(&myaddr6, &saddr6)) { 312 nd6log((LOG_INFO, "nd6_ns_input: duplicate IP6 address %s\n", 313 ip6_sprintf(ip6bufs, &saddr6))); 314 goto freeit; 315 } 316 317 /* 318 * We have neighbor solicitation packet, with target address equals to 319 * one of my tentative address. 320 * 321 * src addr how to process? 322 * --- --- 323 * multicast of course, invalid (rejected in ip6_input) 324 * unicast somebody is doing address resolution -> ignore 325 * unspec dup address detection 326 * 327 * The processing is defined in RFC 2462. 328 */ 329 if (tentative) { 330 /* 331 * If source address is unspecified address, it is for 332 * duplicate address detection. 333 * 334 * If not, the packet is for addess resolution; 335 * silently ignore it. 336 */ 337 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) 338 nd6_dad_ns_input(ifa, ndopts.nd_opts_nonce); 339 340 goto freeit; 341 } 342 343 /* 344 * If the Target Address is either an anycast address or a unicast 345 * address for which the node is providing proxy service, or the Target 346 * Link-Layer Address option is not included, the Override flag SHOULD 347 * be set to zero. Otherwise, the Override flag SHOULD be set to one. 348 */ 349 if (dflags == 0 && (tlladdr & ND6_NA_OPT_LLA) != 0) 350 rflag |= ND_NA_FLAG_OVERRIDE; 351 /* 352 * If the source address is unspecified address, entries must not 353 * be created or updated. 354 * It looks that sender is performing DAD. nd6_na_output() will 355 * send NA toward all-node multicast address, to tell the sender 356 * that I'm using the address. 357 * S bit ("solicited") must be zero. 358 */ 359 if (!IN6_IS_ADDR_UNSPECIFIED(&saddr6)) { 360 nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, 361 ND_NEIGHBOR_SOLICIT, 0); 362 rflag |= ND_NA_FLAG_SOLICITED; 363 } 364 365 /* 366 * RFC 4861, anycast or proxy NA sent in response to a NS SHOULD 367 * be delayed by a random time between 0 and MAX_ANYCAST_DELAY_TIME 368 * to reduce the probability of network congestion. 369 */ 370 if (dflags == 0) 371 nd6_na_output_fib(ifp, &saddr6, &taddr6, rflag, tlladdr, NULL, M_GETFIB(m)); 372 else 373 nd6_queue_add(ifa, &saddr6, &taddr6, &proxydl, arc4random() % 374 (MAX_ANYCAST_DELAY_TIME * hz), dflags); 375 freeit: 376 if (ifa != NULL) 377 ifa_free(ifa); 378 m_freem(m); 379 return; 380 381 bad: 382 nd6log((LOG_ERR, "nd6_ns_input: src=%s\n", 383 ip6_sprintf(ip6bufs, &saddr6))); 384 nd6log((LOG_ERR, "nd6_ns_input: dst=%s\n", 385 ip6_sprintf(ip6bufs, &daddr6))); 386 nd6log((LOG_ERR, "nd6_ns_input: tgt=%s\n", 387 ip6_sprintf(ip6bufs, &taddr6))); 388 bads: 389 ICMP6STAT_INC(icp6s_badns); 390 if (ifa != NULL) 391 ifa_free(ifa); 392 m_freem(m); 393 } 394 395 static struct ifaddr * 396 nd6_proxy_fill_sdl(struct ifnet *ifp, const struct in6_addr *taddr6, 397 struct sockaddr_dl *sdl) 398 { 399 struct ifaddr *ifa; 400 struct llentry *ln; 401 402 ifa = NULL; 403 ln = nd6_lookup(taddr6, LLE_SF(AF_INET6, 0), ifp); 404 if (ln == NULL) 405 return (ifa); 406 if ((ln->la_flags & (LLE_PUB | LLE_VALID)) == (LLE_PUB | LLE_VALID)) { 407 link_init_sdl(ifp, (struct sockaddr *)sdl, ifp->if_type); 408 sdl->sdl_alen = ifp->if_addrlen; 409 bcopy(ln->ll_addr, &sdl->sdl_data, ifp->if_addrlen); 410 LLE_RUNLOCK(ln); 411 ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp, 412 IN6_IFF_NOTREADY|IN6_IFF_ANYCAST); 413 } else 414 LLE_RUNLOCK(ln); 415 416 return (ifa); 417 } 418 419 /* 420 * Output a Neighbor Solicitation Message. Caller specifies: 421 * - ICMP6 header source IP6 address 422 * - ND6 header target IP6 address 423 * - ND6 header source datalink address 424 * 425 * Based on RFC 2461 426 * Based on RFC 2462 (duplicate address detection) 427 * 428 * ln - for source address determination 429 * nonce - If non-NULL, NS is used for duplicate address detection and 430 * the value (length is ND_OPT_NONCE_LEN) is used as a random nonce. 431 */ 432 static void 433 nd6_ns_output_fib(struct ifnet *ifp, const struct in6_addr *saddr6, 434 const struct in6_addr *daddr6, const struct in6_addr *taddr6, 435 uint8_t *nonce, u_int fibnum) 436 { 437 struct mbuf *m; 438 struct m_tag *mtag; 439 struct ip6_hdr *ip6; 440 struct nd_neighbor_solicit *nd_ns; 441 struct ip6_moptions im6o; 442 int icmp6len; 443 int maxlen; 444 445 NET_EPOCH_ASSERT(); 446 447 if (IN6_IS_ADDR_MULTICAST(taddr6)) 448 return; 449 450 /* estimate the size of message */ 451 maxlen = sizeof(*ip6) + sizeof(*nd_ns); 452 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; 453 KASSERT(max_linkhdr + maxlen <= MCLBYTES, ( 454 "%s: max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)", 455 __func__, max_linkhdr, maxlen, MCLBYTES)); 456 457 if (max_linkhdr + maxlen > MHLEN) 458 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 459 else 460 m = m_gethdr(M_NOWAIT, MT_DATA); 461 if (m == NULL) 462 return; 463 M_SETFIB(m, fibnum); 464 465 icmp6len = sizeof(*nd_ns); 466 m->m_pkthdr.len = m->m_len = sizeof(*ip6) + icmp6len; 467 m->m_data += max_linkhdr; /* or M_ALIGN() equivalent? */ 468 469 /* fill neighbor solicitation packet */ 470 ip6 = mtod(m, struct ip6_hdr *); 471 ip6->ip6_flow = 0; 472 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 473 ip6->ip6_vfc |= IPV6_VERSION; 474 /* ip6->ip6_plen will be set later */ 475 ip6->ip6_nxt = IPPROTO_ICMPV6; 476 ip6->ip6_hlim = 255; 477 if (daddr6) 478 ip6->ip6_dst = *daddr6; 479 else { 480 ip6->ip6_dst.s6_addr16[0] = IPV6_ADDR_INT16_MLL; 481 ip6->ip6_dst.s6_addr16[1] = 0; 482 ip6->ip6_dst.s6_addr32[1] = 0; 483 ip6->ip6_dst.s6_addr32[2] = IPV6_ADDR_INT32_ONE; 484 ip6->ip6_dst.s6_addr32[3] = taddr6->s6_addr32[3]; 485 ip6->ip6_dst.s6_addr8[12] = 0xff; 486 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0) 487 goto bad; 488 } 489 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 490 m->m_flags |= M_MCAST; 491 im6o.im6o_multicast_ifp = ifp; 492 im6o.im6o_multicast_hlim = 255; 493 im6o.im6o_multicast_loop = 0; 494 } 495 if (nonce == NULL) { 496 char ip6buf[INET6_ADDRSTRLEN]; 497 struct ifaddr *ifa = NULL; 498 499 /* 500 * RFC2461 7.2.2: 501 * "If the source address of the packet prompting the 502 * solicitation is the same as one of the addresses assigned 503 * to the outgoing interface, that address SHOULD be placed 504 * in the IP Source Address of the outgoing solicitation. 505 * Otherwise, any one of the addresses assigned to the 506 * interface should be used." 507 * 508 * We use the source address for the prompting packet 509 * (saddr6), if saddr6 belongs to the outgoing interface. 510 * Otherwise, we perform the source address selection as usual. 511 */ 512 if (saddr6 != NULL) 513 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, saddr6); 514 if (ifa == NULL) { 515 int error; 516 517 error = in6_selectsrc_nbr(fibnum, &ip6->ip6_dst, &im6o, 518 ifp, &ip6->ip6_src); 519 if (error) { 520 nd6log((LOG_DEBUG, "%s: source can't be " 521 "determined: dst=%s, error=%d\n", __func__, 522 ip6_sprintf(ip6buf, &ip6->ip6_dst), 523 error)); 524 goto bad; 525 } 526 } else 527 ip6->ip6_src = *saddr6; 528 529 if (ifp->if_carp != NULL) { 530 /* 531 * Check that selected source address belongs to 532 * CARP addresses. 533 */ 534 if (ifa == NULL) 535 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, 536 &ip6->ip6_src); 537 /* 538 * Do not send NS for CARP address if we are not 539 * the CARP master. 540 */ 541 if (ifa != NULL && ifa->ifa_carp != NULL && 542 !(*carp_master_p)(ifa)) { 543 nd6log((LOG_DEBUG, 544 "nd6_ns_output: NS from BACKUP CARP address %s\n", 545 ip6_sprintf(ip6buf, &ip6->ip6_src))); 546 ifa_free(ifa); 547 goto bad; 548 } 549 } 550 if (ifa != NULL) 551 ifa_free(ifa); 552 } else { 553 /* 554 * Source address for DAD packet must always be IPv6 555 * unspecified address. (0::0) 556 * We actually don't have to 0-clear the address (we did it 557 * above), but we do so here explicitly to make the intention 558 * clearer. 559 */ 560 bzero(&ip6->ip6_src, sizeof(ip6->ip6_src)); 561 } 562 nd_ns = (struct nd_neighbor_solicit *)(ip6 + 1); 563 nd_ns->nd_ns_type = ND_NEIGHBOR_SOLICIT; 564 nd_ns->nd_ns_code = 0; 565 nd_ns->nd_ns_reserved = 0; 566 nd_ns->nd_ns_target = *taddr6; 567 in6_clearscope(&nd_ns->nd_ns_target); /* XXX */ 568 569 /* 570 * Add source link-layer address option. 571 * 572 * spec implementation 573 * --- --- 574 * DAD packet MUST NOT do not add the option 575 * there's no link layer address: 576 * impossible do not add the option 577 * there's link layer address: 578 * Multicast NS MUST add one add the option 579 * Unicast NS SHOULD add one add the option 580 */ 581 if (nonce == NULL) { 582 struct nd_opt_hdr *nd_opt; 583 char *mac; 584 int optlen; 585 586 mac = NULL; 587 if (ifp->if_carp) 588 mac = (*carp_macmatch6_p)(ifp, m, &ip6->ip6_src); 589 if (mac == NULL) 590 mac = nd6_ifptomac(ifp); 591 592 if (mac != NULL) { 593 nd_opt = (struct nd_opt_hdr *)(nd_ns + 1); 594 optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 595 /* 8 byte alignments... */ 596 optlen = (optlen + 7) & ~7; 597 m->m_pkthdr.len += optlen; 598 m->m_len += optlen; 599 icmp6len += optlen; 600 bzero(nd_opt, optlen); 601 nd_opt->nd_opt_type = ND_OPT_SOURCE_LINKADDR; 602 nd_opt->nd_opt_len = optlen >> 3; 603 bcopy(mac, nd_opt + 1, ifp->if_addrlen); 604 } 605 } 606 /* 607 * Add a Nonce option (RFC 3971) to detect looped back NS messages. 608 * This behavior is documented as Enhanced Duplicate Address 609 * Detection in RFC 7527. 610 * net.inet6.ip6.dad_enhanced=0 disables this. 611 */ 612 if (V_dad_enhanced != 0 && nonce != NULL) { 613 int optlen = sizeof(struct nd_opt_hdr) + ND_OPT_NONCE_LEN; 614 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1); 615 /* 8-byte alignment is required. */ 616 optlen = (optlen + 7) & ~7; 617 618 m->m_pkthdr.len += optlen; 619 m->m_len += optlen; 620 icmp6len += optlen; 621 bzero((caddr_t)nd_opt, optlen); 622 nd_opt->nd_opt_type = ND_OPT_NONCE; 623 nd_opt->nd_opt_len = optlen >> 3; 624 bcopy(nonce, (caddr_t)(nd_opt + 1), ND_OPT_NONCE_LEN); 625 } 626 ip6->ip6_plen = htons((u_short)icmp6len); 627 nd_ns->nd_ns_cksum = 0; 628 nd_ns->nd_ns_cksum = 629 in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), icmp6len); 630 631 if (send_sendso_input_hook != NULL) { 632 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, 633 sizeof(unsigned short), M_NOWAIT); 634 if (mtag == NULL) 635 goto bad; 636 *(unsigned short *)(mtag + 1) = nd_ns->nd_ns_type; 637 m_tag_prepend(m, mtag); 638 } 639 640 ip6_output(m, NULL, NULL, (nonce != NULL) ? IPV6_UNSPECSRC : 0, 641 &im6o, NULL, NULL); 642 icmp6_ifstat_inc(ifp, ifs6_out_msg); 643 icmp6_ifstat_inc(ifp, ifs6_out_neighborsolicit); 644 ICMP6STAT_INC2(icp6s_outhist, ND_NEIGHBOR_SOLICIT); 645 646 return; 647 648 bad: 649 m_freem(m); 650 } 651 652 #ifndef BURN_BRIDGES 653 void 654 nd6_ns_output(struct ifnet *ifp, const struct in6_addr *saddr6, 655 const struct in6_addr *daddr6, const struct in6_addr *taddr6,uint8_t *nonce) 656 { 657 658 nd6_ns_output_fib(ifp, saddr6, daddr6, taddr6, nonce, RT_DEFAULT_FIB); 659 } 660 #endif 661 /* 662 * Neighbor advertisement input handling. 663 * 664 * Based on RFC 2461 665 * Based on RFC 2462 (duplicate address detection) 666 */ 667 void 668 nd6_na_input(struct mbuf *m, int off, int icmp6len) 669 { 670 struct ifnet *ifp; 671 struct ip6_hdr *ip6; 672 struct ifaddr *ifa; 673 struct llentry *ln; 674 struct mbuf *chain; 675 struct nd_neighbor_advert *nd_na; 676 struct in6_addr daddr6, taddr6; 677 union nd_opts ndopts; 678 u_char linkhdr[LLE_MAX_LINKHDR]; 679 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 680 char *lladdr; 681 size_t linkhdrsize; 682 int flags, is_override, is_router, is_solicited; 683 int lladdr_off, lladdrlen, checklink; 684 bool flush_holdchain = false; 685 686 NET_EPOCH_ASSERT(); 687 688 chain = NULL; 689 ln = NULL; 690 checklink = 0; 691 692 /* RFC 6980: Nodes MUST silently ignore fragments */ 693 if(m->m_flags & M_FRAGMENTED) 694 goto freeit; 695 696 ifp = m->m_pkthdr.rcvif; 697 ip6 = mtod(m, struct ip6_hdr *); 698 if (__predict_false(ip6->ip6_hlim != 255)) { 699 ICMP6STAT_INC(icp6s_invlhlim); 700 nd6log((LOG_ERR, 701 "nd6_na_input: invalid hlim (%d) from %s to %s on %s\n", 702 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src), 703 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp))); 704 goto bad; 705 } 706 707 if (m->m_len < off + icmp6len) { 708 m = m_pullup(m, off + icmp6len); 709 if (m == NULL) { 710 IP6STAT_INC(ip6s_exthdrtoolong); 711 return; 712 } 713 } 714 ip6 = mtod(m, struct ip6_hdr *); 715 nd_na = (struct nd_neighbor_advert *)((caddr_t)ip6 + off); 716 717 flags = nd_na->nd_na_flags_reserved; 718 is_router = ((flags & ND_NA_FLAG_ROUTER) != 0); 719 is_solicited = ((flags & ND_NA_FLAG_SOLICITED) != 0); 720 is_override = ((flags & ND_NA_FLAG_OVERRIDE) != 0); 721 722 taddr6 = nd_na->nd_na_target; 723 if (in6_setscope(&taddr6, ifp, NULL)) 724 goto bad; /* XXX: impossible */ 725 726 if (IN6_IS_ADDR_MULTICAST(&taddr6)) { 727 nd6log((LOG_ERR, 728 "nd6_na_input: invalid target address %s\n", 729 ip6_sprintf(ip6bufs, &taddr6))); 730 goto bad; 731 } 732 733 daddr6 = ip6->ip6_dst; 734 if (IN6_IS_ADDR_MULTICAST(&daddr6)) 735 if (is_solicited) { 736 nd6log((LOG_ERR, 737 "nd6_na_input: a solicited adv is multicasted\n")); 738 goto bad; 739 } 740 741 icmp6len -= sizeof(*nd_na); 742 nd6_option_init(nd_na + 1, icmp6len, &ndopts); 743 if (nd6_options(&ndopts) < 0) { 744 nd6log((LOG_INFO, 745 "nd6_na_input: invalid ND option, ignored\n")); 746 /* nd6_options have incremented stats */ 747 goto freeit; 748 } 749 750 lladdr = NULL; 751 lladdrlen = 0; 752 if (ndopts.nd_opts_tgt_lladdr) { 753 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 754 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 755 } 756 757 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6); 758 if (ifa != NULL && ifa->ifa_carp != NULL) { 759 /* 760 * Silently ignore NAs for CARP addresses if we are not 761 * the CARP master. 762 */ 763 if (!(*carp_master_p)(ifa)) { 764 nd6log((LOG_DEBUG, 765 "nd6_na_input: NA for BACKUP CARP address %s\n", 766 ip6_sprintf(ip6bufs, &taddr6))); 767 ifa_free(ifa); 768 goto freeit; 769 } 770 } 771 /* 772 * Target address matches one of my interface address. 773 * 774 * If my address is tentative, this means that there's somebody 775 * already using the same address as mine. This indicates DAD failure. 776 * This is defined in RFC 2462. 777 * 778 * Otherwise, process as defined in RFC 2461. 779 */ 780 if (ifa 781 && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE)) { 782 nd6_dad_na_input(ifa); 783 ifa_free(ifa); 784 goto freeit; 785 } 786 787 /* Just for safety, maybe unnecessary. */ 788 if (ifa) { 789 ifa_free(ifa); 790 log(LOG_ERR, 791 "nd6_na_input: duplicate IP6 address %s\n", 792 ip6_sprintf(ip6bufs, &taddr6)); 793 goto freeit; 794 } 795 796 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 797 nd6log((LOG_INFO, "nd6_na_input: lladdrlen mismatch for %s " 798 "(if %d, NA packet %d)\n", ip6_sprintf(ip6bufs, &taddr6), 799 ifp->if_addrlen, lladdrlen - 2)); 800 goto bad; 801 } 802 803 /* 804 * If no neighbor cache entry is found, NA SHOULD silently be 805 * discarded. 806 */ 807 ln = nd6_lookup(&taddr6, LLE_SF(AF_INET6, LLE_EXCLUSIVE), ifp); 808 if (ln == NULL) { 809 goto freeit; 810 } 811 812 /* 813 * Do not try to override static entry. 814 */ 815 if (ln->la_flags & LLE_STATIC) 816 goto freeit; 817 818 if (ln->ln_state == ND6_LLINFO_INCOMPLETE) { 819 /* 820 * If the link-layer has address, and no lladdr option came, 821 * discard the packet. 822 */ 823 if (ifp->if_addrlen && lladdr == NULL) { 824 goto freeit; 825 } 826 827 /* 828 * Record link-layer address, and update the state. 829 */ 830 if (!nd6_try_set_entry_addr(ifp, ln, lladdr)) 831 goto freeit; 832 833 flush_holdchain = true; 834 if (is_solicited) 835 nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE); 836 else 837 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 838 EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED); 839 if ((ln->ln_router = is_router) != 0) { 840 /* 841 * This means a router's state has changed from 842 * non-reachable to probably reachable, and might 843 * affect the status of associated prefixes.. 844 */ 845 checklink = 1; 846 } 847 } else { 848 int llchange; 849 850 /* 851 * Check if the link-layer address has changed or not. 852 */ 853 if (lladdr == NULL) 854 llchange = 0; 855 else { 856 if (ln->la_flags & LLE_VALID) { 857 if (bcmp(lladdr, ln->ll_addr, ifp->if_addrlen)) 858 llchange = 1; 859 else 860 llchange = 0; 861 } else 862 llchange = 1; 863 } 864 865 /* 866 * This is VERY complex. Look at it with care. 867 * 868 * override solicit lladdr llchange action 869 * (L: record lladdr) 870 * 871 * 0 0 n -- (2c) 872 * 0 0 y n (2b) L 873 * 0 0 y y (1) REACHABLE->STALE 874 * 0 1 n -- (2c) *->REACHABLE 875 * 0 1 y n (2b) L *->REACHABLE 876 * 0 1 y y (1) REACHABLE->STALE 877 * 1 0 n -- (2a) 878 * 1 0 y n (2a) L 879 * 1 0 y y (2a) L *->STALE 880 * 1 1 n -- (2a) *->REACHABLE 881 * 1 1 y n (2a) L *->REACHABLE 882 * 1 1 y y (2a) L *->REACHABLE 883 */ 884 if (!is_override && (lladdr != NULL && llchange)) { /* (1) */ 885 /* 886 * If state is REACHABLE, make it STALE. 887 * no other updates should be done. 888 */ 889 if (ln->ln_state == ND6_LLINFO_REACHABLE) 890 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 891 goto freeit; 892 } else if (is_override /* (2a) */ 893 || (!is_override && (lladdr != NULL && !llchange)) /* (2b) */ 894 || lladdr == NULL) { /* (2c) */ 895 /* 896 * Update link-local address, if any. 897 */ 898 if (lladdr != NULL) { 899 linkhdrsize = sizeof(linkhdr); 900 if (lltable_calc_llheader(ifp, AF_INET6, lladdr, 901 linkhdr, &linkhdrsize, &lladdr_off) != 0) 902 goto freeit; 903 if (lltable_try_set_entry_addr(ifp, ln, linkhdr, 904 linkhdrsize, lladdr_off) == 0) 905 goto freeit; 906 EVENTHANDLER_INVOKE(lle_event, ln, 907 LLENTRY_RESOLVED); 908 } 909 910 /* 911 * If solicited, make the state REACHABLE. 912 * If not solicited and the link-layer address was 913 * changed, make it STALE. 914 */ 915 if (is_solicited) 916 nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE); 917 else { 918 if (lladdr != NULL && llchange) 919 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 920 } 921 } 922 923 if (ln->ln_router && !is_router) { 924 /* 925 * The peer dropped the router flag. 926 * Remove the sender from the Default Router List and 927 * update the Destination Cache entries. 928 */ 929 struct ifnet *nd6_ifp; 930 931 nd6_ifp = lltable_get_ifp(ln->lle_tbl); 932 if (!defrouter_remove(&ln->r_l3addr.addr6, nd6_ifp) && 933 (nd6_ifp->if_inet6->nd_flags & 934 ND6_IFF_ACCEPT_RTADV) != 0) 935 /* 936 * Even if the neighbor is not in the default 937 * router list, the neighbor may be used as a 938 * next hop for some destinations (e.g. redirect 939 * case). So we must call rt6_flush explicitly. 940 */ 941 rt6_flush(&ip6->ip6_src, ifp); 942 } 943 ln->ln_router = is_router; 944 } 945 /* XXX - QL 946 * Does this matter? 947 * rt->rt_flags &= ~RTF_REJECT; 948 */ 949 ln->la_asked = 0; 950 if (ln->la_hold != NULL) 951 chain = nd6_grab_holdchain(ln); 952 freeit: 953 if (ln != NULL) 954 LLE_WUNLOCK(ln); 955 956 if (chain != NULL) 957 nd6_flush_holdchain(ifp, ln, chain); 958 if (flush_holdchain) 959 nd6_flush_children_holdchain(ifp, ln); 960 961 if (checklink) 962 pfxlist_onlink_check(); 963 964 m_freem(m); 965 return; 966 967 bad: 968 if (ln != NULL) 969 LLE_WUNLOCK(ln); 970 971 ICMP6STAT_INC(icp6s_badna); 972 m_freem(m); 973 } 974 975 /* 976 * Neighbor advertisement output handling. 977 * 978 * Based on RFC 2461 979 * 980 * tlladdr: 981 * - 0x01 if include target link-layer address 982 * - 0x02 if target address is CARP MASTER 983 * sdl0 - sockaddr_dl (= proxy NA) or NULL 984 */ 985 static void 986 nd6_na_output_fib(struct ifnet *ifp, const struct in6_addr *daddr6_0, 987 const struct in6_addr *taddr6, u_long flags, int tlladdr, 988 struct sockaddr *sdl0, u_int fibnum) 989 { 990 struct mbuf *m; 991 struct m_tag *mtag; 992 struct ip6_hdr *ip6; 993 struct nd_neighbor_advert *nd_na; 994 struct ip6_moptions im6o; 995 struct in6_addr daddr6; 996 997 NET_EPOCH_ASSERT(); 998 999 int icmp6len, maxlen, error; 1000 caddr_t mac = NULL; 1001 1002 daddr6 = *daddr6_0; /* make a local copy for modification */ 1003 1004 /* estimate the size of message */ 1005 maxlen = sizeof(*ip6) + sizeof(*nd_na); 1006 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; 1007 KASSERT(max_linkhdr + maxlen <= MCLBYTES, ( 1008 "%s: max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)", 1009 __func__, max_linkhdr, maxlen, MCLBYTES)); 1010 1011 if (max_linkhdr + maxlen > MHLEN) 1012 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 1013 else 1014 m = m_gethdr(M_NOWAIT, MT_DATA); 1015 if (m == NULL) 1016 return; 1017 M_SETFIB(m, fibnum); 1018 1019 icmp6len = sizeof(*nd_na); 1020 m->m_pkthdr.len = m->m_len = sizeof(struct ip6_hdr) + icmp6len; 1021 m->m_data += max_linkhdr; /* or M_ALIGN() equivalent? */ 1022 1023 /* fill neighbor advertisement packet */ 1024 ip6 = mtod(m, struct ip6_hdr *); 1025 ip6->ip6_flow = 0; 1026 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 1027 ip6->ip6_vfc |= IPV6_VERSION; 1028 ip6->ip6_nxt = IPPROTO_ICMPV6; 1029 ip6->ip6_hlim = 255; 1030 1031 if (IN6_IS_ADDR_UNSPECIFIED(&daddr6)) { 1032 /* reply to DAD */ 1033 daddr6 = in6addr_linklocal_allnodes; 1034 if (in6_setscope(&daddr6, ifp, NULL)) 1035 goto bad; 1036 1037 flags &= ~ND_NA_FLAG_SOLICITED; 1038 } 1039 if (IN6_IS_ADDR_MULTICAST(&daddr6)) { 1040 m->m_flags |= M_MCAST; 1041 im6o.im6o_multicast_ifp = ifp; 1042 im6o.im6o_multicast_hlim = 255; 1043 im6o.im6o_multicast_loop = 0; 1044 } 1045 1046 ip6->ip6_dst = daddr6; 1047 error = in6_selectsrc_nbr(fibnum, &daddr6, &im6o, ifp, &ip6->ip6_src); 1048 if (error) { 1049 char ip6buf[INET6_ADDRSTRLEN]; 1050 nd6log((LOG_DEBUG, "nd6_na_output: source can't be " 1051 "determined: dst=%s, error=%d\n", 1052 ip6_sprintf(ip6buf, &daddr6), error)); 1053 goto bad; 1054 } 1055 nd_na = (struct nd_neighbor_advert *)(ip6 + 1); 1056 nd_na->nd_na_type = ND_NEIGHBOR_ADVERT; 1057 nd_na->nd_na_code = 0; 1058 nd_na->nd_na_target = *taddr6; 1059 in6_clearscope(&nd_na->nd_na_target); /* XXX */ 1060 1061 /* 1062 * If we respond from CARP address, we need to prepare mac address 1063 * for carp_output(). 1064 */ 1065 if (ifp->if_carp && (tlladdr & ND6_NA_CARP_MASTER)) 1066 mac = (*carp_macmatch6_p)(ifp, m, taddr6); 1067 /* 1068 * "tlladdr" indicates NS's condition for adding tlladdr or not. 1069 * see nd6_ns_input() for details. 1070 * Basically, if NS packet is sent to unicast/anycast addr, 1071 * target lladdr option SHOULD NOT be included. 1072 */ 1073 if (tlladdr & ND6_NA_OPT_LLA) { 1074 /* 1075 * sdl0 != NULL indicates proxy NA. If we do proxy, use 1076 * lladdr in sdl0. If we are not proxying (sending NA for 1077 * my address) use lladdr configured for the interface. 1078 */ 1079 if (sdl0 == NULL) { 1080 if (mac == NULL) 1081 mac = nd6_ifptomac(ifp); 1082 } else if (sdl0->sa_family == AF_LINK) { 1083 struct sockaddr_dl *sdl; 1084 sdl = (struct sockaddr_dl *)sdl0; 1085 if (sdl->sdl_alen == ifp->if_addrlen) 1086 mac = LLADDR(sdl); 1087 } 1088 } 1089 if ((tlladdr & ND6_NA_OPT_LLA) && mac != NULL) { 1090 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 1091 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_na + 1); 1092 1093 /* roundup to 8 bytes alignment! */ 1094 optlen = (optlen + 7) & ~7; 1095 1096 m->m_pkthdr.len += optlen; 1097 m->m_len += optlen; 1098 icmp6len += optlen; 1099 bzero((caddr_t)nd_opt, optlen); 1100 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 1101 nd_opt->nd_opt_len = optlen >> 3; 1102 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen); 1103 } else 1104 flags &= ~ND_NA_FLAG_OVERRIDE; 1105 1106 ip6->ip6_plen = htons((u_short)icmp6len); 1107 nd_na->nd_na_flags_reserved = flags; 1108 nd_na->nd_na_cksum = 0; 1109 nd_na->nd_na_cksum = 1110 in6_cksum(m, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), icmp6len); 1111 1112 if (send_sendso_input_hook != NULL) { 1113 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, 1114 sizeof(unsigned short), M_NOWAIT); 1115 if (mtag == NULL) 1116 goto bad; 1117 *(unsigned short *)(mtag + 1) = nd_na->nd_na_type; 1118 m_tag_prepend(m, mtag); 1119 } 1120 1121 ip6_output(m, NULL, NULL, 0, &im6o, NULL, NULL); 1122 icmp6_ifstat_inc(ifp, ifs6_out_msg); 1123 icmp6_ifstat_inc(ifp, ifs6_out_neighboradvert); 1124 ICMP6STAT_INC2(icp6s_outhist, ND_NEIGHBOR_ADVERT); 1125 1126 return; 1127 1128 bad: 1129 m_freem(m); 1130 } 1131 1132 #ifndef BURN_BRIDGES 1133 void 1134 nd6_na_output(struct ifnet *ifp, const struct in6_addr *daddr6_0, 1135 const struct in6_addr *taddr6, u_long flags, int tlladdr, 1136 struct sockaddr *sdl0) 1137 { 1138 1139 nd6_na_output_fib(ifp, daddr6_0, taddr6, flags, tlladdr, sdl0, 1140 RT_DEFAULT_FIB); 1141 } 1142 #endif 1143 1144 caddr_t 1145 nd6_ifptomac(struct ifnet *ifp) 1146 { 1147 switch (ifp->if_type) { 1148 case IFT_ETHER: 1149 case IFT_IEEE1394: 1150 case IFT_L2VLAN: 1151 case IFT_INFINIBAND: 1152 case IFT_BRIDGE: 1153 return IF_LLADDR(ifp); 1154 default: 1155 return NULL; 1156 } 1157 } 1158 1159 struct dadq { 1160 TAILQ_ENTRY(dadq) dad_list; 1161 struct ifaddr *dad_ifa; 1162 int dad_count; /* max NS to send */ 1163 int dad_ns_tcount; /* # of trials to send NS */ 1164 int dad_ns_ocount; /* NS sent so far */ 1165 int dad_ns_icount; 1166 int dad_na_icount; 1167 int dad_ns_lcount; /* looped back NS */ 1168 int dad_loopbackprobe; /* probing state for loopback detection */ 1169 struct callout dad_timer_ch; 1170 struct vnet *dad_vnet; 1171 u_int dad_refcnt; 1172 #define ND_OPT_NONCE_LEN32 \ 1173 ((ND_OPT_NONCE_LEN + sizeof(uint32_t) - 1)/sizeof(uint32_t)) 1174 uint32_t dad_nonce[ND_OPT_NONCE_LEN32]; 1175 bool dad_ondadq; /* on dadq? Protected by DADQ_WLOCK. */ 1176 }; 1177 1178 VNET_DEFINE_STATIC(TAILQ_HEAD(, dadq), dadq); 1179 VNET_DEFINE_STATIC(struct rwlock, dad_rwlock); 1180 #define V_dadq VNET(dadq) 1181 #define V_dad_rwlock VNET(dad_rwlock) 1182 1183 #define DADQ_LOCKPTR() (&V_dad_rwlock) 1184 #define DADQ_LOCK_INIT() rw_init(DADQ_LOCKPTR(), "nd6 DAD queue") 1185 #define DADQ_RLOCK() rw_rlock(DADQ_LOCKPTR()) 1186 #define DADQ_RUNLOCK() rw_runlock(DADQ_LOCKPTR()) 1187 #define DADQ_WLOCK() rw_wlock(DADQ_LOCKPTR()) 1188 #define DADQ_WUNLOCK() rw_wunlock(DADQ_LOCKPTR()) 1189 1190 #define DADQ_LOCK_ASSERT() rw_assert(DADQ_LOCKPTR(), RA_LOCKED); 1191 #define DADQ_RLOCK_ASSERT() rw_assert(DADQ_LOCKPTR(), RA_RLOCKED); 1192 #define DADQ_WLOCK_ASSERT() rw_assert(DADQ_LOCKPTR(), RA_WLOCKED); 1193 1194 static void 1195 nd6_dad_add(struct dadq *dp) 1196 { 1197 DADQ_WLOCK_ASSERT(); 1198 1199 TAILQ_INSERT_TAIL(&V_dadq, dp, dad_list); 1200 dp->dad_ondadq = true; 1201 } 1202 1203 static void 1204 nd6_dad_del(struct dadq *dp) 1205 { 1206 DADQ_WLOCK_ASSERT(); 1207 1208 if (dp->dad_ondadq) { 1209 /* 1210 * Remove dp from the dadq and release the dadq's 1211 * reference. 1212 */ 1213 TAILQ_REMOVE(&V_dadq, dp, dad_list); 1214 dp->dad_ondadq = false; 1215 nd6_dad_rele(dp); 1216 } 1217 } 1218 1219 static struct dadq * 1220 nd6_dad_find(struct ifaddr *ifa, struct nd_opt_nonce *n) 1221 { 1222 struct dadq *dp; 1223 1224 DADQ_LOCK_ASSERT(); 1225 1226 TAILQ_FOREACH(dp, &V_dadq, dad_list) { 1227 if (dp->dad_ifa != ifa) 1228 continue; 1229 1230 /* 1231 * Skip if the nonce matches the received one. 1232 * +2 in the length is required because of type and 1233 * length fields are included in a header. 1234 */ 1235 if (n != NULL && 1236 n->nd_opt_nonce_len == (ND_OPT_NONCE_LEN + 2) / 8 && 1237 memcmp(&n->nd_opt_nonce[0], &dp->dad_nonce[0], 1238 ND_OPT_NONCE_LEN) == 0) { 1239 dp->dad_ns_lcount++; 1240 continue; 1241 } 1242 break; 1243 } 1244 1245 return (dp); 1246 } 1247 1248 static void 1249 nd6_dad_starttimer(struct dadq *dp, int ticks) 1250 { 1251 DADQ_WLOCK_ASSERT(); 1252 1253 callout_reset(&dp->dad_timer_ch, ticks, nd6_dad_timer, dp); 1254 } 1255 1256 static void 1257 nd6_dad_stoptimer(struct dadq *dp) 1258 { 1259 callout_drain(&dp->dad_timer_ch); 1260 } 1261 1262 static void 1263 nd6_dad_rele(struct dadq *dp) 1264 { 1265 if (refcount_release(&dp->dad_refcnt)) { 1266 KASSERT(!dp->dad_ondadq, ("dp %p still on DAD queue", dp)); 1267 ifa_free(dp->dad_ifa); 1268 free(dp, M_IP6NDP); 1269 } 1270 } 1271 1272 void 1273 nd6_dad_init(void) 1274 { 1275 DADQ_LOCK_INIT(); 1276 TAILQ_INIT(&V_dadq); 1277 } 1278 1279 /* 1280 * Start Duplicate Address Detection (DAD) for specified interface address. 1281 */ 1282 void 1283 nd6_dad_start(struct ifaddr *ifa, int delay) 1284 { 1285 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1286 struct dadq *dp; 1287 char ip6buf[INET6_ADDRSTRLEN]; 1288 1289 KASSERT((ia->ia6_flags & IN6_IFF_TENTATIVE) != 0, 1290 ("starting DAD on non-tentative address %p", ifa)); 1291 1292 /* 1293 * If we don't need DAD, don't do it. 1294 * There are several cases: 1295 * - DAD is disabled globally or on the interface 1296 * - the interface address is anycast 1297 */ 1298 if ((ia->ia6_flags & IN6_IFF_ANYCAST) != 0 || 1299 V_ip6_dad_count == 0 || 1300 (ifa->ifa_ifp->if_inet6->nd_flags & ND6_IFF_NO_DAD) != 0) { 1301 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1302 return; 1303 } 1304 if ((ifa->ifa_ifp->if_flags & IFF_UP) == 0 || 1305 (ifa->ifa_ifp->if_drv_flags & IFF_DRV_RUNNING) == 0 || 1306 (ifa->ifa_ifp->if_inet6->nd_flags & ND6_IFF_IFDISABLED) != 0) 1307 return; 1308 1309 DADQ_WLOCK(); 1310 if ((dp = nd6_dad_find(ifa, NULL)) != NULL) { 1311 /* 1312 * DAD is already in progress. Let the existing entry 1313 * finish it. 1314 */ 1315 DADQ_WUNLOCK(); 1316 return; 1317 } 1318 1319 dp = malloc(sizeof(*dp), M_IP6NDP, M_NOWAIT | M_ZERO); 1320 if (dp == NULL) { 1321 log(LOG_ERR, "nd6_dad_start: memory allocation failed for " 1322 "%s(%s)\n", 1323 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1324 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1325 return; 1326 } 1327 callout_init_rw(&dp->dad_timer_ch, DADQ_LOCKPTR(), 1328 CALLOUT_RETURNUNLOCKED); 1329 #ifdef VIMAGE 1330 dp->dad_vnet = curvnet; 1331 #endif 1332 nd6log((LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp), 1333 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr))); 1334 1335 /* 1336 * Send NS packet for DAD, ip6_dad_count times. 1337 * Note that we must delay the first transmission, if this is the 1338 * first packet to be sent from the interface after interface 1339 * (re)initialization. 1340 */ 1341 dp->dad_ifa = ifa; 1342 ifa_ref(dp->dad_ifa); 1343 dp->dad_count = V_ip6_dad_count; 1344 dp->dad_ns_icount = dp->dad_na_icount = 0; 1345 dp->dad_ns_ocount = dp->dad_ns_tcount = 0; 1346 dp->dad_ns_lcount = dp->dad_loopbackprobe = 0; 1347 1348 /* Add this to the dadq and add a reference for the dadq. */ 1349 refcount_init(&dp->dad_refcnt, 1); 1350 nd6_dad_add(dp); 1351 nd6_dad_starttimer(dp, delay); 1352 DADQ_WUNLOCK(); 1353 } 1354 1355 /* 1356 * terminate DAD unconditionally. used for address removals. 1357 */ 1358 void 1359 nd6_dad_stop(struct ifaddr *ifa) 1360 { 1361 struct dadq *dp; 1362 1363 DADQ_WLOCK(); 1364 dp = nd6_dad_find(ifa, NULL); 1365 if (dp == NULL) { 1366 DADQ_WUNLOCK(); 1367 /* DAD wasn't started yet */ 1368 return; 1369 } 1370 1371 /* 1372 * Acquire a temporary reference so that we can safely stop the callout. 1373 */ 1374 (void)refcount_acquire(&dp->dad_refcnt); 1375 nd6_dad_del(dp); 1376 DADQ_WUNLOCK(); 1377 1378 nd6_dad_stoptimer(dp); 1379 nd6_dad_rele(dp); 1380 } 1381 1382 static void 1383 nd6_dad_timer(void *arg) 1384 { 1385 struct dadq *dp = arg; 1386 struct ifaddr *ifa = dp->dad_ifa; 1387 struct ifnet *ifp = dp->dad_ifa->ifa_ifp; 1388 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1389 char ip6buf[INET6_ADDRSTRLEN]; 1390 struct epoch_tracker et; 1391 1392 CURVNET_SET(dp->dad_vnet); 1393 KASSERT(ia != NULL, ("DAD entry %p with no address", dp)); 1394 1395 NET_EPOCH_ENTER(et); 1396 if (ifp->if_inet6->nd_flags & ND6_IFF_IFDISABLED) { 1397 /* Do not need DAD for ifdisabled interface. */ 1398 log(LOG_ERR, "nd6_dad_timer: cancel DAD on %s because of " 1399 "ND6_IFF_IFDISABLED.\n", ifp->if_xname); 1400 goto err; 1401 } 1402 if (ia->ia6_flags & IN6_IFF_DUPLICATED) { 1403 log(LOG_ERR, "nd6_dad_timer: called with duplicated address " 1404 "%s(%s)\n", 1405 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1406 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1407 goto err; 1408 } 1409 if ((ia->ia6_flags & IN6_IFF_TENTATIVE) == 0) { 1410 log(LOG_ERR, "nd6_dad_timer: called with non-tentative address " 1411 "%s(%s)\n", 1412 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1413 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1414 goto err; 1415 } 1416 1417 /* Stop DAD if the interface is down even after dad_maxtry attempts. */ 1418 if ((dp->dad_ns_tcount > V_dad_maxtry) && 1419 (((ifp->if_flags & IFF_UP) == 0) || 1420 ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0))) { 1421 nd6log((LOG_INFO, "%s: could not run DAD " 1422 "because the interface was down or not running.\n", 1423 if_name(ifa->ifa_ifp))); 1424 goto err; 1425 } 1426 1427 /* Need more checks? */ 1428 if (dp->dad_ns_ocount < dp->dad_count) { 1429 /* 1430 * We have more NS to go. Send NS packet for DAD. 1431 */ 1432 nd6_dad_starttimer(dp, 1433 (long)ifa->ifa_ifp->if_inet6->nd_retrans * hz / 1000); 1434 nd6_dad_ns_output(dp); 1435 goto done; 1436 } else { 1437 /* 1438 * We have transmitted sufficient number of DAD packets. 1439 * See what we've got. 1440 */ 1441 if (dp->dad_ns_icount > 0 || dp->dad_na_icount > 0) { 1442 /* We've seen NS or NA, means DAD has failed. */ 1443 nd6_dad_duplicated(ifa, dp); 1444 } else if (V_dad_enhanced != 0 && 1445 dp->dad_ns_lcount > 0 && 1446 dp->dad_ns_lcount > dp->dad_loopbackprobe) { 1447 /* 1448 * Sec. 4.1 in RFC 7527 requires transmission of 1449 * additional probes until the loopback condition 1450 * becomes clear when a looped back probe is detected. 1451 */ 1452 log(LOG_ERR, "%s: a looped back NS message is " 1453 "detected during DAD for %s. " 1454 "Another DAD probes are being sent.\n", 1455 if_name(ifa->ifa_ifp), 1456 ip6_sprintf(ip6buf, IFA_IN6(ifa))); 1457 dp->dad_loopbackprobe = dp->dad_ns_lcount; 1458 /* 1459 * Send an NS immediately and increase dad_count by 1460 * V_nd6_mmaxtries - 1. 1461 */ 1462 dp->dad_count = 1463 dp->dad_ns_ocount + V_nd6_mmaxtries - 1; 1464 nd6_dad_starttimer(dp, 1465 (long)ifa->ifa_ifp->if_inet6->nd_retrans * hz / 1000); 1466 nd6_dad_ns_output(dp); 1467 goto done; 1468 } else { 1469 /* 1470 * We are done with DAD. No NA came, no NS came. 1471 * No duplicate address found. Check IFDISABLED flag 1472 * again in case that it is changed between the 1473 * beginning of this function and here. 1474 * 1475 * Reset DAD failures counter if using stable addresses. 1476 */ 1477 if ((ifp->if_inet6->nd_flags & ND6_IFF_IFDISABLED) == 0) { 1478 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1479 if ((ifp->if_inet6->nd_flags & ND6_IFF_STABLEADDR) && !(ia->ia6_flags & IN6_IFF_TEMPORARY)) 1480 atomic_store_int(&DAD_FAILURES(ifp), 0); 1481 /* 1482 * RFC 9131 Section 6.1.2: The first advertisement 1483 * SHOULD be sent as soon as an address changes the 1484 * state from tentative to preferred. 1485 */ 1486 nd6_grand_start(ifa, ND6_QUEUE_FLAG_NEWGUA); 1487 } 1488 1489 nd6log((LOG_DEBUG, 1490 "%s: DAD complete for %s - no duplicates found\n", 1491 if_name(ifa->ifa_ifp), 1492 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr))); 1493 if (dp->dad_ns_lcount > 0) 1494 log(LOG_ERR, "%s: DAD completed while " 1495 "a looped back NS message is detected " 1496 "during DAD for %s.\n", 1497 if_name(ifa->ifa_ifp), 1498 ip6_sprintf(ip6buf, IFA_IN6(ifa))); 1499 } 1500 } 1501 err: 1502 nd6_dad_del(dp); 1503 DADQ_WUNLOCK(); 1504 done: 1505 NET_EPOCH_EXIT(et); 1506 CURVNET_RESTORE(); 1507 } 1508 1509 static void 1510 nd6_dad_duplicated(struct ifaddr *ifa, struct dadq *dp) 1511 { 1512 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1513 struct ifnet *ifp; 1514 char ip6buf[INET6_ADDRSTRLEN]; 1515 1516 ifp = ifa->ifa_ifp; 1517 1518 log(LOG_ERR, "%s: DAD detected duplicate IPv6 address %s: " 1519 "NS in/out/loopback=%d/%d/%d, NA in=%d\n", 1520 if_name(ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1521 dp->dad_ns_icount, dp->dad_ns_ocount, dp->dad_ns_lcount, 1522 dp->dad_na_icount); 1523 1524 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1525 ia->ia6_flags |= IN6_IFF_DUPLICATED; 1526 1527 log(LOG_ERR, "%s: DAD complete for %s - duplicate found\n", 1528 if_name(ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)); 1529 1530 /* 1531 * For RFC 7217 stable addresses, increment failure counter here if we still have retries. 1532 * More addresses will be generated as long as retries are not exhausted. 1533 */ 1534 if ((ifp->if_inet6->nd_flags & ND6_IFF_STABLEADDR) && !(ia->ia6_flags & IN6_IFF_TEMPORARY)) { 1535 u_int dad_failures = atomic_load_int(&DAD_FAILURES(ifp)); 1536 1537 if (dad_failures <= V_ip6_stableaddr_maxretries) { 1538 atomic_add_int(&DAD_FAILURES(ifp), 1); 1539 /* if retries exhausted, output an informative error message */ 1540 if (dad_failures == V_ip6_stableaddr_maxretries) 1541 log(LOG_ERR, "%s: manual intervention required, consider disabling \"stableaddr\" on the interface" 1542 " or checking hostuuid for uniqueness\n", 1543 if_name(ifp)); 1544 } 1545 } else { 1546 log(LOG_ERR, "%s: manual intervention required\n", 1547 if_name(ifp)); 1548 } 1549 1550 /* 1551 * If the address is a link-local address formed from an interface 1552 * identifier based on the hardware address which is supposed to be 1553 * uniquely assigned (e.g., EUI-64 for an Ethernet interface), IP 1554 * operation on the interface SHOULD be disabled. 1555 * [RFC 4862, Section 5.4.5] 1556 */ 1557 if (IN6_IS_ADDR_LINKLOCAL(&ia->ia_addr.sin6_addr)) { 1558 struct in6_addr in6; 1559 1560 /* 1561 * To avoid over-reaction, we only apply this logic when we are 1562 * very sure that hardware addresses are supposed to be unique. 1563 */ 1564 switch (ifp->if_type) { 1565 case IFT_ETHER: 1566 case IFT_ATM: 1567 case IFT_IEEE1394: 1568 case IFT_INFINIBAND: 1569 in6 = ia->ia_addr.sin6_addr; 1570 if (in6_get_hw_ifid(ifp, &in6) == 0 && 1571 IN6_ARE_ADDR_EQUAL(&ia->ia_addr.sin6_addr, &in6)) { 1572 ifp->if_inet6->nd_flags |= ND6_IFF_IFDISABLED; 1573 log(LOG_ERR, "%s: possible hardware address " 1574 "duplication detected, disable IPv6\n", 1575 if_name(ifp)); 1576 } 1577 break; 1578 } 1579 } 1580 } 1581 1582 /* 1583 * Transmit a neighbour solicitation for the purpose of DAD. Returns with the 1584 * DAD queue unlocked. 1585 */ 1586 static void 1587 nd6_dad_ns_output(struct dadq *dp) 1588 { 1589 struct in6_ifaddr *ia = (struct in6_ifaddr *)dp->dad_ifa; 1590 struct ifnet *ifp = dp->dad_ifa->ifa_ifp; 1591 int i; 1592 1593 DADQ_WLOCK_ASSERT(); 1594 1595 dp->dad_ns_tcount++; 1596 if ((ifp->if_flags & IFF_UP) == 0) { 1597 DADQ_WUNLOCK(); 1598 return; 1599 } 1600 if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) { 1601 DADQ_WUNLOCK(); 1602 return; 1603 } 1604 1605 dp->dad_ns_ocount++; 1606 if (V_dad_enhanced != 0) { 1607 for (i = 0; i < ND_OPT_NONCE_LEN32; i++) 1608 dp->dad_nonce[i] = arc4random(); 1609 /* 1610 * XXXHRS: Note that in the case that 1611 * DupAddrDetectTransmits > 1, multiple NS messages with 1612 * different nonces can be looped back in an unexpected 1613 * order. The current implementation recognizes only 1614 * the latest nonce on the sender side. Practically it 1615 * should work well in almost all cases. 1616 */ 1617 } 1618 DADQ_WUNLOCK(); 1619 nd6_ns_output(ifp, NULL, NULL, &ia->ia_addr.sin6_addr, 1620 (uint8_t *)&dp->dad_nonce[0]); 1621 } 1622 1623 static void 1624 nd6_dad_ns_input(struct ifaddr *ifa, struct nd_opt_nonce *ndopt_nonce) 1625 { 1626 struct dadq *dp; 1627 1628 if (ifa == NULL) 1629 panic("ifa == NULL in nd6_dad_ns_input"); 1630 1631 /* Ignore Nonce option when Enhanced DAD is disabled. */ 1632 if (V_dad_enhanced == 0) 1633 ndopt_nonce = NULL; 1634 DADQ_RLOCK(); 1635 dp = nd6_dad_find(ifa, ndopt_nonce); 1636 if (dp != NULL) 1637 dp->dad_ns_icount++; 1638 DADQ_RUNLOCK(); 1639 } 1640 1641 static void 1642 nd6_dad_na_input(struct ifaddr *ifa) 1643 { 1644 struct dadq *dp; 1645 1646 if (ifa == NULL) 1647 panic("ifa == NULL in nd6_dad_na_input"); 1648 1649 DADQ_RLOCK(); 1650 dp = nd6_dad_find(ifa, NULL); 1651 if (dp != NULL) 1652 dp->dad_na_icount++; 1653 DADQ_RUNLOCK(); 1654 } 1655 1656 static void 1657 nd6_queue_rel(void *arg) 1658 { 1659 struct nd_queue *ndq = arg; 1660 struct ifaddr *ifa; 1661 1662 ifa = ndq->ndq_ifa; 1663 IF_ADDR_WLOCK_ASSERT(ifa->ifa_ifp); 1664 1665 /* Remove ndq from the nd_queue list and free it */ 1666 TAILQ_REMOVE(&ifa->ifa_ifp->if_inet6->nd_queue, ndq, ndq_list); 1667 IF_ADDR_WUNLOCK(ifa->ifa_ifp); 1668 1669 free(ndq, M_IP6NDP); 1670 ifa_free(ifa); 1671 } 1672 1673 static void 1674 nd6_queue_timer(void *arg) 1675 { 1676 struct nd_queue *ndq = arg; 1677 struct ifaddr *ifa = ndq->ndq_ifa; 1678 struct ifnet *ifp; 1679 struct in6_addr daddr, taddr; 1680 struct sockaddr_dl sdl; 1681 struct epoch_tracker et; 1682 int delay, tlladdr; 1683 u_long flags; 1684 bool proxy; 1685 1686 KASSERT(ifa != NULL, ("ND6 queue entry %p with no address", ndq)); 1687 1688 ifp = ifa->ifa_ifp; 1689 CURVNET_SET(ifp->if_vnet); 1690 NET_EPOCH_ENTER(et); 1691 1692 daddr = ndq->ndq_daddr; 1693 taddr = ndq->ndq_taddr; 1694 tlladdr = ND6_NA_OPT_LLA; 1695 flags = (V_ip6_forwarding) ? ND_NA_FLAG_ROUTER : 0; 1696 if ((ifp->if_inet6->nd_flags & ND6_IFF_ACCEPT_RTADV) != 0 && V_ip6_norbit_raif) 1697 flags &= ~ND_NA_FLAG_ROUTER; 1698 1699 /* 1700 * RFC 9131 Section 6.1.2: If the address is preferred, 1701 * then the Override flag SHOULD NOT be set. 1702 */ 1703 if ((ndq->ndq_flags & ND6_QUEUE_FLAG_NEWGUA) != 0) { 1704 /* 1705 * XXX: If the address is in the Optimistic state, 1706 * then the Override flag MUST NOT be set. 1707 * We don't support RFC 4429 yet. 1708 */ 1709 if ((ifp->if_inet6->nd_flags & ND6_IFF_PREFER_SOURCE) == 0) 1710 flags |= ND_NA_FLAG_OVERRIDE; 1711 } 1712 /* 1713 * RFC 4861 Section 7.2.6: if link-layer address changed, 1714 * The Override flag MAY be set to either zero or one. 1715 */ 1716 if ((ndq->ndq_flags & ND6_QUEUE_FLAG_LLADDR) != 0) 1717 flags |= ND_NA_FLAG_OVERRIDE; 1718 /* anycast advertisement delay rule (RFC 4861 7.2.7, SHOULD) */ 1719 if ((ndq->ndq_flags & ND6_QUEUE_FLAG_ANYCAST) != 0) 1720 flags |= ND_NA_FLAG_SOLICITED; 1721 /* proxy advertisement delay rule (RFC 4861 7.2.8, SHOULD) */ 1722 proxy = false; 1723 if ((ndq->ndq_flags & ND6_QUEUE_FLAG_PROXY) != 0) { 1724 flags |= ND_NA_FLAG_SOLICITED; 1725 sdl = ndq->ndq_sdl; 1726 proxy = true; 1727 } 1728 1729 /* 1730 * if it was GRAND, wait at least a RetransTimer 1731 * before removing from queue. 1732 */ 1733 if ((ndq->ndq_flags & ND6_QUEUE_GRAND_MASK) != 0) { 1734 delay = ifp->if_inet6->nd_retrans * hz / 1000; 1735 callout_reset(&ndq->ndq_callout, delay, nd6_queue_rel, ndq); 1736 IF_ADDR_WUNLOCK(ifp); 1737 } else 1738 nd6_queue_rel(ndq); 1739 1740 if (__predict_true(in6_setscope(&daddr, ifp, NULL) == 0)) 1741 nd6_na_output_fib(ifp, &daddr, &taddr, flags, tlladdr, 1742 proxy ? (struct sockaddr *)&sdl : NULL, ifp->if_fib); 1743 1744 NET_EPOCH_EXIT(et); 1745 CURVNET_RESTORE(); 1746 } 1747 1748 /* 1749 * Queue a delayed IPv6 Neighbor Advertisement. 1750 * 1751 * daddr: destination address (who the NA is sent to) 1752 * taddr: target address being advertised (used for proxy NAs) 1753 * sdl: link-layer address (used for proxy NAs) 1754 */ 1755 static void 1756 nd6_queue_add(struct ifaddr *ifa, struct in6_addr *daddr, 1757 struct in6_addr *taddr, struct sockaddr_dl *sdl, int delay, uint32_t flags) 1758 { 1759 struct nd_queue *ndq = NULL; 1760 struct ifnet *ifp; 1761 struct in6_ifextra *ext; 1762 char ip6buf[INET6_ADDRSTRLEN]; 1763 1764 NET_EPOCH_ASSERT(); 1765 1766 ifp = ifa->ifa_ifp; 1767 ext = ifp->if_inet6; 1768 IF_ADDR_WLOCK(ifp); 1769 /* 1770 * if request comes from GRAND, check whether another delayed 1771 * GRAND NA exists in the queue. 1772 * If it exists, cancel previous one and reuse its ndq. 1773 */ 1774 if ((flags & ND6_QUEUE_GRAND_MASK) != 0) { 1775 TAILQ_FOREACH(ndq, &ext->nd_queue, ndq_list) { 1776 if (ndq->ndq_ifa == ifa && 1777 (flags & ND6_QUEUE_GRAND_MASK) != 0) 1778 break; 1779 } 1780 } 1781 if (ndq == NULL) { 1782 ndq = malloc(sizeof(*ndq), M_IP6NDP, M_NOWAIT | M_ZERO); 1783 if (ndq == NULL) { 1784 log(LOG_ERR, "%s: memory allocation failed for %s(%s)\n", 1785 __func__, ip6_sprintf(ip6buf, IFA_IN6(ifa)), 1786 ifp ? if_name(ifp) : "???"); 1787 IF_ADDR_WUNLOCK(ifp); 1788 return; 1789 } 1790 1791 callout_init_mtx(&ndq->ndq_callout, &ifp->if_addr_lock, 1792 CALLOUT_TRYLOCK | CALLOUT_RETURNUNLOCKED); 1793 ifa_ref(ifa); 1794 ndq->ndq_ifa = ifa; 1795 TAILQ_INSERT_TAIL(&ext->nd_queue, ndq, ndq_list); 1796 } 1797 1798 memcpy(&ndq->ndq_daddr, daddr, sizeof(struct in6_addr)); 1799 /* 1800 * For proxy NAs, the target address (taddr) being advertised differs from 1801 * the interface address (ifa), so we must explicitly store both the proxy 1802 * target address and its link-layer address (sdl). 1803 * For non-proxy NAs, use the interface address (ifa) itself as the target. 1804 */ 1805 if ((flags & ND6_QUEUE_FLAG_PROXY) != 0) { 1806 memcpy(&ndq->ndq_taddr, taddr, sizeof(struct in6_addr)); 1807 memcpy(&ndq->ndq_sdl, sdl, sizeof(struct sockaddr_dl)); 1808 } else 1809 memcpy(&ndq->ndq_taddr, IFA_IN6(ifa), sizeof(struct in6_addr)); 1810 ndq->ndq_flags = flags; 1811 1812 nd6log((LOG_DEBUG, "%s: delay IPv6 NA for %s\n", if_name(ifp), 1813 ip6_sprintf(ip6buf, IFA_IN6(ifa)))); 1814 callout_reset(&ndq->ndq_callout, delay, nd6_queue_timer, ndq); 1815 IF_ADDR_WUNLOCK(ifp); 1816 } 1817 1818 /* 1819 * Start Gratuitous Neighbor Discovery (GRAND) for specified address. 1820 * Called after DAD completes and by interface link layer change event. 1821 */ 1822 void 1823 nd6_grand_start(struct ifaddr *ifa, uint32_t flags) 1824 { 1825 struct nd_queue *ndq; 1826 struct in6_ifextra *ext = ifa->ifa_ifp->if_inet6; 1827 struct in6_addr daddr = IN6ADDR_ANY_INIT; 1828 int delay, count = 0; 1829 1830 NET_EPOCH_ASSERT(); 1831 /* If we don't need GRAND, don't do it. */ 1832 if (V_ip6_grand_count == 0 || 1833 ifa->ifa_carp != NULL) 1834 return; 1835 1836 /* Check if new address is global */ 1837 if ((flags & ND6_QUEUE_FLAG_NEWGUA) != 0 && 1838 in6_addrscope(IFA_IN6(ifa)) != IPV6_ADDR_SCOPE_GLOBAL) 1839 return; 1840 1841 /* 1842 * RFC 9131 Section 6.1.2: These advertisements MUST be 1843 * separated by at least RetransTimer seconds. 1844 */ 1845 TAILQ_FOREACH(ndq, &ext->nd_queue, ndq_list) { 1846 /* 1847 * RFC 9131 Section 6.1.2: a node SHOULD send 1848 * up to MAX_NEIGHBOR_ADVERTISEMENT Neighbor Advertisement messages. 1849 * Make sure we don't queue GRAND more than V_ip6_grand_count 1850 * per interface. 1851 * Since this limitation only applies to GRAND, don't 1852 * count non-GRAND ndq. 1853 */ 1854 if ((ndq->ndq_flags & ND6_QUEUE_GRAND_MASK) == 0) 1855 continue; 1856 1857 count++; 1858 if (count >= V_ip6_grand_count) 1859 return; 1860 } 1861 1862 /* 1863 * RFC 9131 Section 6.1.2: if new global address added, 1864 * use the all-routers multicast address. 1865 */ 1866 if ((flags & ND6_QUEUE_FLAG_NEWGUA) != 0) 1867 daddr = in6addr_linklocal_allrouters; 1868 1869 /* 1870 * RFC 4861 Section 7.2.6: if link-layer address changed, 1871 * use the all-nodes multicast address. 1872 */ 1873 if ((flags & ND6_QUEUE_FLAG_LLADDR) != 0) 1874 daddr = in6addr_linklocal_allnodes; 1875 1876 delay = ext->nd_retrans * hz / 1000; 1877 nd6_queue_add(ifa, &daddr, NULL, NULL, count * delay, flags); 1878 } 1879 1880 /* 1881 * drain nd6 queue. used for address removals. 1882 */ 1883 void 1884 nd6_queue_stop(struct ifaddr *ifa) 1885 { 1886 struct nd_queue *ndq, *dndq; 1887 struct ifnet *ifp; 1888 1889 ifp = ifa->ifa_ifp; 1890 IF_ADDR_WLOCK(ifp); 1891 TAILQ_FOREACH_SAFE(ndq, &ifp->if_inet6->nd_queue, ndq_list, dndq) { 1892 if (ndq->ndq_ifa != ifa) 1893 continue; 1894 1895 callout_stop(&ndq->ndq_callout); 1896 1897 /* Remove ndq from the nd_queue list and free it */ 1898 TAILQ_REMOVE(&ifa->ifa_ifp->if_inet6->nd_queue, ndq, ndq_list); 1899 free(ndq, M_IP6NDP); 1900 ifa_free(ifa); 1901 } 1902 IF_ADDR_WUNLOCK(ifp); 1903 } 1904