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: icmp6.c,v 1.211 2001/04/04 05:56:20 itojun Exp $ 32 */ 33 34 /*- 35 * Copyright (c) 1982, 1986, 1988, 1993 36 * The Regents of the University of California. All rights reserved. 37 * 38 * Redistribution and use in source and binary forms, with or without 39 * modification, are permitted provided that the following conditions 40 * are met: 41 * 1. Redistributions of source code must retain the above copyright 42 * notice, this list of conditions and the following disclaimer. 43 * 2. Redistributions in binary form must reproduce the above copyright 44 * notice, this list of conditions and the following disclaimer in the 45 * documentation and/or other materials provided with the distribution. 46 * 3. Neither the name of the University nor the names of its contributors 47 * may be used to endorse or promote products derived from this software 48 * without specific prior written permission. 49 * 50 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 51 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 52 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 53 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 54 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 55 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 56 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 57 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 58 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 59 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 60 * SUCH DAMAGE. 61 * 62 * @(#)ip_icmp.c 8.2 (Berkeley) 1/4/94 63 */ 64 65 #include <sys/cdefs.h> 66 __FBSDID("$FreeBSD$"); 67 68 #define MBUF_PRIVATE /* XXXRW: Optimisation tries to avoid M_EXT mbufs */ 69 70 #include "opt_inet.h" 71 #include "opt_inet6.h" 72 73 #include <sys/param.h> 74 #include <sys/domain.h> 75 #include <sys/jail.h> 76 #include <sys/kernel.h> 77 #include <sys/lock.h> 78 #include <sys/malloc.h> 79 #include <sys/mbuf.h> 80 #include <sys/proc.h> 81 #include <sys/protosw.h> 82 #include <sys/signalvar.h> 83 #include <sys/socket.h> 84 #include <sys/socketvar.h> 85 #include <sys/sx.h> 86 #include <sys/syslog.h> 87 #include <sys/systm.h> 88 #include <sys/time.h> 89 90 #include <net/if.h> 91 #include <net/if_var.h> 92 #include <net/if_dl.h> 93 #include <net/if_llatbl.h> 94 #include <net/if_types.h> 95 #include <net/route.h> 96 #include <net/route/route_ctl.h> 97 #include <net/route/nhop.h> 98 #include <net/vnet.h> 99 100 #include <netinet/in.h> 101 #include <netinet/in_pcb.h> 102 #include <netinet/in_var.h> 103 #include <netinet/ip6.h> 104 #include <netinet/icmp6.h> 105 #include <netinet/tcp_var.h> 106 107 #include <netinet6/in6_fib.h> 108 #include <netinet6/in6_ifattach.h> 109 #include <netinet6/in6_pcb.h> 110 #include <netinet6/ip6protosw.h> 111 #include <netinet6/ip6_var.h> 112 #include <netinet6/scope6_var.h> 113 #include <netinet6/mld6_var.h> 114 #include <netinet6/nd6.h> 115 #include <netinet6/send.h> 116 117 extern struct domain inet6domain; 118 119 VNET_PCPUSTAT_DEFINE(struct icmp6stat, icmp6stat); 120 VNET_PCPUSTAT_SYSINIT(icmp6stat); 121 122 #ifdef VIMAGE 123 VNET_PCPUSTAT_SYSUNINIT(icmp6stat); 124 #endif /* VIMAGE */ 125 126 VNET_DECLARE(struct inpcbinfo, ripcbinfo); 127 VNET_DECLARE(int, icmp6errppslim); 128 VNET_DEFINE_STATIC(int, icmp6errpps_count) = 0; 129 VNET_DEFINE_STATIC(struct timeval, icmp6errppslim_last); 130 VNET_DECLARE(int, icmp6_nodeinfo); 131 132 #define V_ripcbinfo VNET(ripcbinfo) 133 #define V_icmp6errppslim VNET(icmp6errppslim) 134 #define V_icmp6errpps_count VNET(icmp6errpps_count) 135 #define V_icmp6errppslim_last VNET(icmp6errppslim_last) 136 #define V_icmp6_nodeinfo VNET(icmp6_nodeinfo) 137 138 static void icmp6_errcount(int, int); 139 static int icmp6_rip6_input(struct mbuf **, int); 140 static void icmp6_reflect(struct mbuf *, size_t); 141 static int icmp6_ratelimit(const struct in6_addr *, const int, const int); 142 static const char *icmp6_redirect_diag(struct in6_addr *, 143 struct in6_addr *, struct in6_addr *); 144 static struct mbuf *ni6_input(struct mbuf *, int, struct prison *); 145 static struct mbuf *ni6_nametodns(const char *, int, int); 146 static int ni6_dnsmatch(const char *, int, const char *, int); 147 static int ni6_addrs(struct icmp6_nodeinfo *, struct mbuf *, 148 struct ifnet **, struct in6_addr *); 149 static int ni6_store_addrs(struct icmp6_nodeinfo *, struct icmp6_nodeinfo *, 150 struct ifnet *, int); 151 static int icmp6_notify_error(struct mbuf **, int, int, int); 152 153 /* 154 * Kernel module interface for updating icmp6stat. The argument is an index 155 * into icmp6stat treated as an array of u_quad_t. While this encodes the 156 * general layout of icmp6stat into the caller, it doesn't encode its 157 * location, so that future changes to add, for example, per-CPU stats 158 * support won't cause binary compatibility problems for kernel modules. 159 */ 160 void 161 kmod_icmp6stat_inc(int statnum) 162 { 163 164 counter_u64_add(VNET(icmp6stat)[statnum], 1); 165 } 166 167 static void 168 icmp6_errcount(int type, int code) 169 { 170 switch (type) { 171 case ICMP6_DST_UNREACH: 172 switch (code) { 173 case ICMP6_DST_UNREACH_NOROUTE: 174 ICMP6STAT_INC(icp6s_odst_unreach_noroute); 175 return; 176 case ICMP6_DST_UNREACH_ADMIN: 177 ICMP6STAT_INC(icp6s_odst_unreach_admin); 178 return; 179 case ICMP6_DST_UNREACH_BEYONDSCOPE: 180 ICMP6STAT_INC(icp6s_odst_unreach_beyondscope); 181 return; 182 case ICMP6_DST_UNREACH_ADDR: 183 ICMP6STAT_INC(icp6s_odst_unreach_addr); 184 return; 185 case ICMP6_DST_UNREACH_NOPORT: 186 ICMP6STAT_INC(icp6s_odst_unreach_noport); 187 return; 188 } 189 break; 190 case ICMP6_PACKET_TOO_BIG: 191 ICMP6STAT_INC(icp6s_opacket_too_big); 192 return; 193 case ICMP6_TIME_EXCEEDED: 194 switch (code) { 195 case ICMP6_TIME_EXCEED_TRANSIT: 196 ICMP6STAT_INC(icp6s_otime_exceed_transit); 197 return; 198 case ICMP6_TIME_EXCEED_REASSEMBLY: 199 ICMP6STAT_INC(icp6s_otime_exceed_reassembly); 200 return; 201 } 202 break; 203 case ICMP6_PARAM_PROB: 204 switch (code) { 205 case ICMP6_PARAMPROB_HEADER: 206 ICMP6STAT_INC(icp6s_oparamprob_header); 207 return; 208 case ICMP6_PARAMPROB_NEXTHEADER: 209 ICMP6STAT_INC(icp6s_oparamprob_nextheader); 210 return; 211 case ICMP6_PARAMPROB_OPTION: 212 ICMP6STAT_INC(icp6s_oparamprob_option); 213 return; 214 } 215 break; 216 case ND_REDIRECT: 217 ICMP6STAT_INC(icp6s_oredirect); 218 return; 219 } 220 ICMP6STAT_INC(icp6s_ounknown); 221 } 222 223 /* 224 * A wrapper function for icmp6_error() necessary when the erroneous packet 225 * may not contain enough scope zone information. 226 */ 227 void 228 icmp6_error2(struct mbuf *m, int type, int code, int param, 229 struct ifnet *ifp) 230 { 231 struct ip6_hdr *ip6; 232 233 if (ifp == NULL) 234 return; 235 236 if (m->m_len < sizeof(struct ip6_hdr)) { 237 m = m_pullup(m, sizeof(struct ip6_hdr)); 238 if (m == NULL) { 239 IP6STAT_INC(ip6s_exthdrtoolong); 240 return; 241 } 242 } 243 ip6 = mtod(m, struct ip6_hdr *); 244 245 if (in6_setscope(&ip6->ip6_src, ifp, NULL) != 0) 246 return; 247 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0) 248 return; 249 250 icmp6_error(m, type, code, param); 251 } 252 253 /* 254 * Generate an error packet of type error in response to bad IP6 packet. 255 */ 256 void 257 icmp6_error(struct mbuf *m, int type, int code, int param) 258 { 259 struct ip6_hdr *oip6, *nip6; 260 struct icmp6_hdr *icmp6; 261 struct epoch_tracker et; 262 u_int preplen; 263 int off; 264 int nxt; 265 266 ICMP6STAT_INC(icp6s_error); 267 268 /* count per-type-code statistics */ 269 icmp6_errcount(type, code); 270 271 #ifdef M_DECRYPTED /*not openbsd*/ 272 if (m->m_flags & M_DECRYPTED) { 273 ICMP6STAT_INC(icp6s_canterror); 274 goto freeit; 275 } 276 #endif 277 278 if (m->m_len < sizeof(struct ip6_hdr)) { 279 m = m_pullup(m, sizeof(struct ip6_hdr)); 280 if (m == NULL) { 281 IP6STAT_INC(ip6s_exthdrtoolong); 282 return; 283 } 284 } 285 oip6 = mtod(m, struct ip6_hdr *); 286 287 /* 288 * If the destination address of the erroneous packet is a multicast 289 * address, or the packet was sent using link-layer multicast, 290 * we should basically suppress sending an error (RFC 2463, Section 291 * 2.4). 292 * We have two exceptions (the item e.2 in that section): 293 * - the Packet Too Big message can be sent for path MTU discovery. 294 * - the Parameter Problem Message that can be allowed an icmp6 error 295 * in the option type field. This check has been done in 296 * ip6_unknown_opt(), so we can just check the type and code. 297 */ 298 if ((m->m_flags & (M_BCAST|M_MCAST) || 299 IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) && 300 (type != ICMP6_PACKET_TOO_BIG && 301 (type != ICMP6_PARAM_PROB || 302 code != ICMP6_PARAMPROB_OPTION))) 303 goto freeit; 304 305 /* 306 * RFC 2463, 2.4 (e.5): source address check. 307 * XXX: the case of anycast source? 308 */ 309 if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) || 310 IN6_IS_ADDR_MULTICAST(&oip6->ip6_src)) 311 goto freeit; 312 313 /* 314 * If we are about to send ICMPv6 against ICMPv6 error/redirect, 315 * don't do it. 316 */ 317 nxt = -1; 318 off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt); 319 if (off >= 0 && nxt == IPPROTO_ICMPV6) { 320 struct icmp6_hdr *icp; 321 322 if (m->m_len < off + sizeof(struct icmp6_hdr)) { 323 m = m_pullup(m, off + sizeof(struct icmp6_hdr)); 324 if (m == NULL) { 325 IP6STAT_INC(ip6s_exthdrtoolong); 326 return; 327 } 328 } 329 oip6 = mtod(m, struct ip6_hdr *); 330 icp = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 331 332 if (icp->icmp6_type < ICMP6_ECHO_REQUEST || 333 icp->icmp6_type == ND_REDIRECT) { 334 /* 335 * ICMPv6 error 336 * Special case: for redirect (which is 337 * informational) we must not send icmp6 error. 338 */ 339 ICMP6STAT_INC(icp6s_canterror); 340 goto freeit; 341 } else { 342 /* ICMPv6 informational - send the error */ 343 } 344 } else { 345 /* non-ICMPv6 - send the error */ 346 } 347 348 /* Finally, do rate limitation check. */ 349 if (icmp6_ratelimit(&oip6->ip6_src, type, code)) { 350 ICMP6STAT_INC(icp6s_toofreq); 351 goto freeit; 352 } 353 354 /* 355 * OK, ICMP6 can be generated. 356 */ 357 358 if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN) 359 m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len); 360 361 preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 362 M_PREPEND(m, preplen, M_NOWAIT); /* FIB is also copied over. */ 363 if (m == NULL) { 364 nd6log((LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__)); 365 return; 366 } 367 368 nip6 = mtod(m, struct ip6_hdr *); 369 nip6->ip6_src = oip6->ip6_src; 370 nip6->ip6_dst = oip6->ip6_dst; 371 372 in6_clearscope(&oip6->ip6_src); 373 in6_clearscope(&oip6->ip6_dst); 374 375 icmp6 = (struct icmp6_hdr *)(nip6 + 1); 376 icmp6->icmp6_type = type; 377 icmp6->icmp6_code = code; 378 icmp6->icmp6_pptr = htonl((u_int32_t)param); 379 380 ICMP6STAT_INC(icp6s_outhist[type]); 381 NET_EPOCH_ENTER(et); 382 icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */ 383 NET_EPOCH_EXIT(et); 384 385 return; 386 387 freeit: 388 /* 389 * If we can't tell whether or not we can generate ICMP6, free it. 390 */ 391 m_freem(m); 392 } 393 394 /* 395 * Process a received ICMP6 message. 396 */ 397 int 398 icmp6_input(struct mbuf **mp, int *offp, int proto) 399 { 400 struct mbuf *m, *n; 401 struct ifnet *ifp; 402 struct ip6_hdr *ip6, *nip6; 403 struct icmp6_hdr *icmp6, *nicmp6; 404 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 405 int code, error, icmp6len, ip6len, noff, off, sum; 406 407 NET_EPOCH_ASSERT(); 408 409 m = *mp; 410 off = *offp; 411 412 if (m->m_len < off + sizeof(struct icmp6_hdr)) { 413 m = m_pullup(m, off + sizeof(struct icmp6_hdr)); 414 if (m == NULL) { 415 IP6STAT_INC(ip6s_exthdrtoolong); 416 *mp = m; 417 return (IPPROTO_DONE); 418 } 419 } 420 421 /* 422 * Locate icmp6 structure in mbuf, and check 423 * that not corrupted and of at least minimum length 424 */ 425 426 icmp6len = m->m_pkthdr.len - off; 427 if (icmp6len < sizeof(struct icmp6_hdr)) { 428 ICMP6STAT_INC(icp6s_tooshort); 429 goto freeit; 430 } 431 432 ip6 = mtod(m, struct ip6_hdr *); 433 ifp = m->m_pkthdr.rcvif; 434 /* 435 * Check multicast group membership. 436 * Note: SSM filters are not applied for ICMPv6 traffic. 437 */ 438 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 439 struct in6_multi *inm; 440 441 inm = in6m_lookup(ifp, &ip6->ip6_dst); 442 if (inm == NULL) { 443 IP6STAT_INC(ip6s_notmember); 444 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 445 goto freeit; 446 } 447 } 448 449 /* Calculate the checksum. */ 450 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off); 451 code = icmp6->icmp6_code; 452 if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) { 453 nd6log((LOG_ERR, 454 "ICMP6 checksum error(%d|%x) %s\n", 455 icmp6->icmp6_type, sum, 456 ip6_sprintf(ip6bufs, &ip6->ip6_src))); 457 ICMP6STAT_INC(icp6s_checksum); 458 goto freeit; 459 } 460 461 ICMP6STAT_INC(icp6s_inhist[icmp6->icmp6_type]); 462 icmp6_ifstat_inc(ifp, ifs6_in_msg); 463 if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK) 464 icmp6_ifstat_inc(ifp, ifs6_in_error); 465 466 ip6len = sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen); 467 switch (icmp6->icmp6_type) { 468 case ICMP6_DST_UNREACH: 469 icmp6_ifstat_inc(ifp, ifs6_in_dstunreach); 470 switch (code) { 471 case ICMP6_DST_UNREACH_NOROUTE: 472 case ICMP6_DST_UNREACH_ADDR: /* PRC_HOSTDEAD is a DOS */ 473 code = PRC_UNREACH_NET; 474 break; 475 case ICMP6_DST_UNREACH_ADMIN: 476 icmp6_ifstat_inc(ifp, ifs6_in_adminprohib); 477 code = PRC_UNREACH_ADMIN_PROHIB; 478 break; 479 case ICMP6_DST_UNREACH_BEYONDSCOPE: 480 /* I mean "source address was incorrect." */ 481 code = PRC_PARAMPROB; 482 break; 483 case ICMP6_DST_UNREACH_NOPORT: 484 code = PRC_UNREACH_PORT; 485 break; 486 default: 487 goto badcode; 488 } 489 goto deliver; 490 break; 491 492 case ICMP6_PACKET_TOO_BIG: 493 icmp6_ifstat_inc(ifp, ifs6_in_pkttoobig); 494 495 /* validation is made in icmp6_mtudisc_update */ 496 497 code = PRC_MSGSIZE; 498 499 /* 500 * Updating the path MTU will be done after examining 501 * intermediate extension headers. 502 */ 503 goto deliver; 504 break; 505 506 case ICMP6_TIME_EXCEEDED: 507 icmp6_ifstat_inc(ifp, ifs6_in_timeexceed); 508 switch (code) { 509 case ICMP6_TIME_EXCEED_TRANSIT: 510 code = PRC_TIMXCEED_INTRANS; 511 break; 512 case ICMP6_TIME_EXCEED_REASSEMBLY: 513 code = PRC_TIMXCEED_REASS; 514 break; 515 default: 516 goto badcode; 517 } 518 goto deliver; 519 break; 520 521 case ICMP6_PARAM_PROB: 522 icmp6_ifstat_inc(ifp, ifs6_in_paramprob); 523 switch (code) { 524 case ICMP6_PARAMPROB_NEXTHEADER: 525 code = PRC_UNREACH_PROTOCOL; 526 break; 527 case ICMP6_PARAMPROB_HEADER: 528 case ICMP6_PARAMPROB_OPTION: 529 code = PRC_PARAMPROB; 530 break; 531 default: 532 goto badcode; 533 } 534 goto deliver; 535 break; 536 537 case ICMP6_ECHO_REQUEST: 538 icmp6_ifstat_inc(ifp, ifs6_in_echo); 539 if (code != 0) 540 goto badcode; 541 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) { 542 /* Give up remote */ 543 break; 544 } 545 if (!M_WRITABLE(n) 546 || n->m_len < off + sizeof(struct icmp6_hdr)) { 547 struct mbuf *n0 = n; 548 int n0len; 549 550 CTASSERT(sizeof(*nip6) + sizeof(*nicmp6) <= MHLEN); 551 n = m_gethdr(M_NOWAIT, n0->m_type); 552 if (n == NULL) { 553 /* Give up remote */ 554 m_freem(n0); 555 break; 556 } 557 558 m_move_pkthdr(n, n0); /* FIB copied. */ 559 n0len = n0->m_pkthdr.len; /* save for use below */ 560 /* 561 * Copy IPv6 and ICMPv6 only. 562 */ 563 nip6 = mtod(n, struct ip6_hdr *); 564 bcopy(ip6, nip6, sizeof(struct ip6_hdr)); 565 nicmp6 = (struct icmp6_hdr *)(nip6 + 1); 566 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr)); 567 noff = sizeof(struct ip6_hdr); 568 /* new mbuf contains only ipv6+icmpv6 headers */ 569 n->m_len = noff + sizeof(struct icmp6_hdr); 570 /* 571 * Adjust mbuf. ip6_plen will be adjusted in 572 * ip6_output(). 573 */ 574 m_adj(n0, off + sizeof(struct icmp6_hdr)); 575 /* recalculate complete packet size */ 576 n->m_pkthdr.len = n0len + (noff - off); 577 n->m_next = n0; 578 } else { 579 if (n->m_len < off + sizeof(*nicmp6)) { 580 n = m_pullup(n, off + sizeof(*nicmp6)); 581 if (n == NULL) { 582 IP6STAT_INC(ip6s_exthdrtoolong); 583 break; 584 } 585 } 586 nicmp6 = (struct icmp6_hdr *)(mtod(n, caddr_t) + off); 587 noff = off; 588 } 589 if (n) { 590 nicmp6->icmp6_type = ICMP6_ECHO_REPLY; 591 nicmp6->icmp6_code = 0; 592 ICMP6STAT_INC(icp6s_reflect); 593 ICMP6STAT_INC(icp6s_outhist[ICMP6_ECHO_REPLY]); 594 icmp6_reflect(n, noff); 595 } 596 break; 597 598 case ICMP6_ECHO_REPLY: 599 icmp6_ifstat_inc(ifp, ifs6_in_echoreply); 600 if (code != 0) 601 goto badcode; 602 break; 603 604 case MLD_LISTENER_QUERY: 605 case MLD_LISTENER_REPORT: 606 case MLD_LISTENER_DONE: 607 case MLDV2_LISTENER_REPORT: 608 /* 609 * Drop MLD traffic which is not link-local, has a hop limit 610 * of greater than 1 hop, or which does not have the 611 * IPv6 HBH Router Alert option. 612 * As IPv6 HBH options are stripped in ip6_input() we must 613 * check an mbuf header flag. 614 * XXX Should we also sanity check that these messages 615 * were directed to a link-local multicast prefix? 616 */ 617 if ((ip6->ip6_hlim != 1) || (m->m_flags & M_RTALERT_MLD) == 0) 618 goto freeit; 619 if (mld_input(&m, off, icmp6len) != 0) { 620 *mp = NULL; 621 return (IPPROTO_DONE); 622 } 623 /* m stays. */ 624 break; 625 626 case ICMP6_WRUREQUEST: /* ICMP6_FQDN_QUERY */ 627 { 628 enum { WRU, FQDN } mode; 629 struct prison *pr; 630 631 if (!V_icmp6_nodeinfo) 632 break; 633 634 if (icmp6len == sizeof(struct icmp6_hdr) + 4) 635 mode = WRU; 636 else if (icmp6len >= sizeof(struct icmp6_nodeinfo)) 637 mode = FQDN; 638 else 639 goto badlen; 640 641 pr = NULL; 642 sx_slock(&allprison_lock); 643 TAILQ_FOREACH(pr, &allprison, pr_list) 644 if (pr->pr_vnet == ifp->if_vnet) 645 break; 646 sx_sunlock(&allprison_lock); 647 if (pr == NULL) 648 pr = curthread->td_ucred->cr_prison; 649 if (mode == FQDN) { 650 if (m->m_len < off + sizeof(struct icmp6_nodeinfo)) { 651 m = m_pullup(m, off + 652 sizeof(struct icmp6_nodeinfo)); 653 if (m == NULL) { 654 IP6STAT_INC(ip6s_exthdrtoolong); 655 *mp = m; 656 return (IPPROTO_DONE); 657 } 658 } 659 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 660 if (n) 661 n = ni6_input(n, off, pr); 662 /* XXX meaningless if n == NULL */ 663 noff = sizeof(struct ip6_hdr); 664 } else { 665 u_char *p; 666 int maxhlen, hlen; 667 668 /* 669 * XXX: this combination of flags is pointless, 670 * but should we keep this for compatibility? 671 */ 672 if ((V_icmp6_nodeinfo & (ICMP6_NODEINFO_FQDNOK | 673 ICMP6_NODEINFO_TMPADDROK)) != 674 (ICMP6_NODEINFO_FQDNOK | ICMP6_NODEINFO_TMPADDROK)) 675 break; 676 677 if (code != 0) 678 goto badcode; 679 680 CTASSERT(sizeof(*nip6) + sizeof(*nicmp6) + 4 <= MHLEN); 681 n = m_gethdr(M_NOWAIT, m->m_type); 682 if (n == NULL) { 683 /* Give up remote */ 684 break; 685 } 686 if (!m_dup_pkthdr(n, m, M_NOWAIT)) { 687 /* 688 * Previous code did a blind M_COPY_PKTHDR 689 * and said "just for rcvif". If true, then 690 * we could tolerate the dup failing (due to 691 * the deep copy of the tag chain). For now 692 * be conservative and just fail. 693 */ 694 m_free(n); 695 n = NULL; 696 break; 697 } 698 /* 699 * Copy IPv6 and ICMPv6 only. 700 */ 701 nip6 = mtod(n, struct ip6_hdr *); 702 bcopy(ip6, nip6, sizeof(struct ip6_hdr)); 703 nicmp6 = (struct icmp6_hdr *)(nip6 + 1); 704 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr)); 705 p = (u_char *)(nicmp6 + 1); 706 bzero(p, 4); 707 708 maxhlen = M_TRAILINGSPACE(n) - 709 (sizeof(*nip6) + sizeof(*nicmp6) + 4); 710 mtx_lock(&pr->pr_mtx); 711 hlen = strlen(pr->pr_hostname); 712 if (maxhlen > hlen) 713 maxhlen = hlen; 714 /* meaningless TTL */ 715 bcopy(pr->pr_hostname, p + 4, maxhlen); 716 mtx_unlock(&pr->pr_mtx); 717 noff = sizeof(struct ip6_hdr); 718 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + 719 sizeof(struct icmp6_hdr) + 4 + maxhlen; 720 nicmp6->icmp6_type = ICMP6_WRUREPLY; 721 nicmp6->icmp6_code = 0; 722 } 723 if (n) { 724 ICMP6STAT_INC(icp6s_reflect); 725 ICMP6STAT_INC(icp6s_outhist[ICMP6_WRUREPLY]); 726 icmp6_reflect(n, noff); 727 } 728 break; 729 } 730 731 case ICMP6_WRUREPLY: 732 if (code != 0) 733 goto badcode; 734 break; 735 736 case ND_ROUTER_SOLICIT: 737 icmp6_ifstat_inc(ifp, ifs6_in_routersolicit); 738 if (code != 0) 739 goto badcode; 740 if (icmp6len < sizeof(struct nd_router_solicit)) 741 goto badlen; 742 if (send_sendso_input_hook != NULL) { 743 if (m->m_len < off + icmp6len) { 744 m = m_pullup(m, off + icmp6len); 745 if (m == NULL) { 746 IP6STAT_INC(ip6s_exthdrtoolong); 747 *mp = NULL; 748 return (IPPROTO_DONE); 749 } 750 } 751 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 752 if (error == 0) { 753 m = NULL; 754 goto freeit; 755 } 756 } 757 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 758 nd6_rs_input(m, off, icmp6len); 759 m = n; 760 if (m == NULL) 761 goto freeit; 762 break; 763 764 case ND_ROUTER_ADVERT: 765 icmp6_ifstat_inc(ifp, ifs6_in_routeradvert); 766 if (code != 0) 767 goto badcode; 768 if (icmp6len < sizeof(struct nd_router_advert)) 769 goto badlen; 770 if (send_sendso_input_hook != NULL) { 771 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 772 if (error == 0) { 773 m = NULL; 774 goto freeit; 775 } 776 } 777 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 778 nd6_ra_input(m, off, icmp6len); 779 m = n; 780 if (m == NULL) 781 goto freeit; 782 break; 783 784 case ND_NEIGHBOR_SOLICIT: 785 icmp6_ifstat_inc(ifp, ifs6_in_neighborsolicit); 786 if (code != 0) 787 goto badcode; 788 if (icmp6len < sizeof(struct nd_neighbor_solicit)) 789 goto badlen; 790 if (send_sendso_input_hook != NULL) { 791 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 792 if (error == 0) { 793 m = NULL; 794 goto freeit; 795 } 796 } 797 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 798 nd6_ns_input(m, off, icmp6len); 799 m = n; 800 if (m == NULL) 801 goto freeit; 802 break; 803 804 case ND_NEIGHBOR_ADVERT: 805 icmp6_ifstat_inc(ifp, ifs6_in_neighboradvert); 806 if (code != 0) 807 goto badcode; 808 if (icmp6len < sizeof(struct nd_neighbor_advert)) 809 goto badlen; 810 if (send_sendso_input_hook != NULL) { 811 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 812 if (error == 0) { 813 m = NULL; 814 goto freeit; 815 } 816 } 817 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 818 nd6_na_input(m, off, icmp6len); 819 m = n; 820 if (m == NULL) 821 goto freeit; 822 break; 823 824 case ND_REDIRECT: 825 icmp6_ifstat_inc(ifp, ifs6_in_redirect); 826 if (code != 0) 827 goto badcode; 828 if (icmp6len < sizeof(struct nd_redirect)) 829 goto badlen; 830 if (send_sendso_input_hook != NULL) { 831 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 832 if (error == 0) { 833 m = NULL; 834 goto freeit; 835 } 836 } 837 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 838 icmp6_redirect_input(m, off); 839 m = n; 840 if (m == NULL) 841 goto freeit; 842 break; 843 844 case ICMP6_ROUTER_RENUMBERING: 845 if (code != ICMP6_ROUTER_RENUMBERING_COMMAND && 846 code != ICMP6_ROUTER_RENUMBERING_RESULT) 847 goto badcode; 848 if (icmp6len < sizeof(struct icmp6_router_renum)) 849 goto badlen; 850 break; 851 852 default: 853 nd6log((LOG_DEBUG, 854 "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n", 855 icmp6->icmp6_type, ip6_sprintf(ip6bufs, &ip6->ip6_src), 856 ip6_sprintf(ip6bufd, &ip6->ip6_dst), 857 ifp ? ifp->if_index : 0)); 858 if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) { 859 /* ICMPv6 error: MUST deliver it by spec... */ 860 code = PRC_NCMDS; 861 /* deliver */ 862 } else { 863 /* ICMPv6 informational: MUST not deliver */ 864 break; 865 } 866 deliver: 867 if (icmp6_notify_error(&m, off, icmp6len, code) != 0) { 868 /* In this case, m should've been freed. */ 869 *mp = NULL; 870 return (IPPROTO_DONE); 871 } 872 break; 873 874 badcode: 875 ICMP6STAT_INC(icp6s_badcode); 876 break; 877 878 badlen: 879 ICMP6STAT_INC(icp6s_badlen); 880 break; 881 } 882 883 /* deliver the packet to appropriate sockets */ 884 icmp6_rip6_input(&m, *offp); 885 886 *mp = m; 887 return (IPPROTO_DONE); 888 889 freeit: 890 m_freem(m); 891 *mp = NULL; 892 return (IPPROTO_DONE); 893 } 894 895 static int 896 icmp6_notify_error(struct mbuf **mp, int off, int icmp6len, int code) 897 { 898 struct mbuf *m; 899 struct icmp6_hdr *icmp6; 900 struct ip6_hdr *eip6; 901 u_int32_t notifymtu; 902 struct sockaddr_in6 icmp6src, icmp6dst; 903 904 m = *mp; 905 906 if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) { 907 ICMP6STAT_INC(icp6s_tooshort); 908 goto freeit; 909 } 910 911 if (m->m_len < off + sizeof(*icmp6) + sizeof(struct ip6_hdr)) { 912 m = m_pullup(m, off + sizeof(*icmp6) + sizeof(struct ip6_hdr)); 913 if (m == NULL) { 914 IP6STAT_INC(ip6s_exthdrtoolong); 915 *mp = m; 916 return (-1); 917 } 918 } 919 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 920 eip6 = (struct ip6_hdr *)(icmp6 + 1); 921 bzero(&icmp6dst, sizeof(icmp6dst)); 922 923 /* Detect the upper level protocol */ 924 { 925 void (*ctlfunc)(int, struct sockaddr *, void *); 926 u_int8_t nxt = eip6->ip6_nxt; 927 int eoff = off + sizeof(struct icmp6_hdr) + 928 sizeof(struct ip6_hdr); 929 struct ip6ctlparam ip6cp; 930 int icmp6type = icmp6->icmp6_type; 931 struct ip6_frag *fh; 932 struct ip6_rthdr *rth; 933 struct ip6_rthdr0 *rth0; 934 int rthlen; 935 936 while (1) { /* XXX: should avoid infinite loop explicitly? */ 937 struct ip6_ext *eh; 938 939 switch (nxt) { 940 case IPPROTO_HOPOPTS: 941 case IPPROTO_DSTOPTS: 942 case IPPROTO_AH: 943 if (m->m_len < eoff + sizeof(struct ip6_ext)) { 944 m = m_pullup(m, eoff + 945 sizeof(struct ip6_ext)); 946 if (m == NULL) { 947 IP6STAT_INC(ip6s_exthdrtoolong); 948 *mp = m; 949 return (-1); 950 } 951 } 952 eh = (struct ip6_ext *) 953 (mtod(m, caddr_t) + eoff); 954 if (nxt == IPPROTO_AH) 955 eoff += (eh->ip6e_len + 2) << 2; 956 else 957 eoff += (eh->ip6e_len + 1) << 3; 958 nxt = eh->ip6e_nxt; 959 break; 960 case IPPROTO_ROUTING: 961 /* 962 * When the erroneous packet contains a 963 * routing header, we should examine the 964 * header to determine the final destination. 965 * Otherwise, we can't properly update 966 * information that depends on the final 967 * destination (e.g. path MTU). 968 */ 969 if (m->m_len < eoff + sizeof(*rth)) { 970 m = m_pullup(m, eoff + sizeof(*rth)); 971 if (m == NULL) { 972 IP6STAT_INC(ip6s_exthdrtoolong); 973 *mp = m; 974 return (-1); 975 } 976 } 977 rth = (struct ip6_rthdr *) 978 (mtod(m, caddr_t) + eoff); 979 rthlen = (rth->ip6r_len + 1) << 3; 980 /* 981 * XXX: currently there is no 982 * officially defined type other 983 * than type-0. 984 * Note that if the segment left field 985 * is 0, all intermediate hops must 986 * have been passed. 987 */ 988 if (rth->ip6r_segleft && 989 rth->ip6r_type == IPV6_RTHDR_TYPE_0) { 990 int hops; 991 992 if (m->m_len < eoff + rthlen) { 993 m = m_pullup(m, eoff + rthlen); 994 if (m == NULL) { 995 IP6STAT_INC( 996 ip6s_exthdrtoolong); 997 *mp = m; 998 return (-1); 999 } 1000 } 1001 rth0 = (struct ip6_rthdr0 *) 1002 (mtod(m, caddr_t) + eoff); 1003 1004 /* just ignore a bogus header */ 1005 if ((rth0->ip6r0_len % 2) == 0 && 1006 (hops = rth0->ip6r0_len/2)) 1007 icmp6dst.sin6_addr = *((struct in6_addr *)(rth0 + 1) + (hops - 1)); 1008 } 1009 eoff += rthlen; 1010 nxt = rth->ip6r_nxt; 1011 break; 1012 case IPPROTO_FRAGMENT: 1013 if (m->m_len < eoff + sizeof(struct ip6_frag)) { 1014 m = m_pullup(m, eoff + 1015 sizeof(struct ip6_frag)); 1016 if (m == NULL) { 1017 IP6STAT_INC(ip6s_exthdrtoolong); 1018 *mp = m; 1019 return (-1); 1020 } 1021 } 1022 fh = (struct ip6_frag *)(mtod(m, caddr_t) + 1023 eoff); 1024 /* 1025 * Data after a fragment header is meaningless 1026 * unless it is the first fragment, but 1027 * we'll go to the notify label for path MTU 1028 * discovery. 1029 */ 1030 if (fh->ip6f_offlg & IP6F_OFF_MASK) 1031 goto notify; 1032 1033 eoff += sizeof(struct ip6_frag); 1034 nxt = fh->ip6f_nxt; 1035 break; 1036 default: 1037 /* 1038 * This case includes ESP and the No Next 1039 * Header. In such cases going to the notify 1040 * label does not have any meaning 1041 * (i.e. ctlfunc will be NULL), but we go 1042 * anyway since we might have to update 1043 * path MTU information. 1044 */ 1045 goto notify; 1046 } 1047 } 1048 notify: 1049 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 1050 1051 /* 1052 * retrieve parameters from the inner IPv6 header, and convert 1053 * them into sockaddr structures. 1054 * XXX: there is no guarantee that the source or destination 1055 * addresses of the inner packet are in the same scope as 1056 * the addresses of the icmp packet. But there is no other 1057 * way to determine the zone. 1058 */ 1059 eip6 = (struct ip6_hdr *)(icmp6 + 1); 1060 1061 icmp6dst.sin6_len = sizeof(struct sockaddr_in6); 1062 icmp6dst.sin6_family = AF_INET6; 1063 if (IN6_IS_ADDR_UNSPECIFIED(&icmp6dst.sin6_addr)) 1064 icmp6dst.sin6_addr = eip6->ip6_dst; 1065 if (in6_setscope(&icmp6dst.sin6_addr, m->m_pkthdr.rcvif, NULL)) 1066 goto freeit; 1067 bzero(&icmp6src, sizeof(icmp6src)); 1068 icmp6src.sin6_len = sizeof(struct sockaddr_in6); 1069 icmp6src.sin6_family = AF_INET6; 1070 icmp6src.sin6_addr = eip6->ip6_src; 1071 if (in6_setscope(&icmp6src.sin6_addr, m->m_pkthdr.rcvif, NULL)) 1072 goto freeit; 1073 icmp6src.sin6_flowinfo = 1074 (eip6->ip6_flow & IPV6_FLOWLABEL_MASK); 1075 1076 ip6cp.ip6c_m = m; 1077 ip6cp.ip6c_icmp6 = icmp6; 1078 ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1); 1079 ip6cp.ip6c_off = eoff; 1080 ip6cp.ip6c_finaldst = &icmp6dst.sin6_addr; 1081 ip6cp.ip6c_src = &icmp6src; 1082 ip6cp.ip6c_nxt = nxt; 1083 1084 if (icmp6type == ICMP6_PACKET_TOO_BIG) { 1085 notifymtu = ntohl(icmp6->icmp6_mtu); 1086 ip6cp.ip6c_cmdarg = (void *)¬ifymtu; 1087 icmp6_mtudisc_update(&ip6cp, 1); /*XXX*/ 1088 } 1089 1090 ctlfunc = (void (*)(int, struct sockaddr *, void *)) 1091 (inet6sw[ip6_protox[nxt]].pr_ctlinput); 1092 if (ctlfunc) { 1093 (void) (*ctlfunc)(code, (struct sockaddr *)&icmp6dst, 1094 &ip6cp); 1095 } 1096 } 1097 *mp = m; 1098 return (0); 1099 1100 freeit: 1101 m_freem(m); 1102 *mp = NULL; 1103 return (-1); 1104 } 1105 1106 void 1107 icmp6_mtudisc_update(struct ip6ctlparam *ip6cp, int validated) 1108 { 1109 struct in6_addr *dst = ip6cp->ip6c_finaldst; 1110 struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6; 1111 struct mbuf *m = ip6cp->ip6c_m; /* will be necessary for scope issue */ 1112 u_int mtu = ntohl(icmp6->icmp6_mtu); 1113 struct in_conninfo inc; 1114 uint32_t max_mtu; 1115 1116 #if 0 1117 /* 1118 * RFC2460 section 5, last paragraph. 1119 * even though minimum link MTU for IPv6 is IPV6_MMTU, 1120 * we may see ICMPv6 too big with mtu < IPV6_MMTU 1121 * due to packet translator in the middle. 1122 * see ip6_output() and ip6_getpmtu() "alwaysfrag" case for 1123 * special handling. 1124 */ 1125 if (mtu < IPV6_MMTU) 1126 return; 1127 #endif 1128 1129 /* 1130 * we reject ICMPv6 too big with abnormally small value. 1131 * XXX what is the good definition of "abnormally small"? 1132 */ 1133 if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8) 1134 return; 1135 1136 if (!validated) 1137 return; 1138 1139 /* 1140 * In case the suggested mtu is less than IPV6_MMTU, we 1141 * only need to remember that it was for above mentioned 1142 * "alwaysfrag" case. 1143 * Try to be as close to the spec as possible. 1144 */ 1145 if (mtu < IPV6_MMTU) 1146 mtu = IPV6_MMTU - 8; 1147 1148 bzero(&inc, sizeof(inc)); 1149 inc.inc_fibnum = M_GETFIB(m); 1150 inc.inc_flags |= INC_ISIPV6; 1151 inc.inc6_faddr = *dst; 1152 if (in6_setscope(&inc.inc6_faddr, m->m_pkthdr.rcvif, NULL)) 1153 return; 1154 1155 max_mtu = tcp_hc_getmtu(&inc); 1156 if (max_mtu == 0) 1157 max_mtu = tcp_maxmtu6(&inc, NULL); 1158 1159 if (mtu < max_mtu) { 1160 tcp_hc_updatemtu(&inc, mtu); 1161 ICMP6STAT_INC(icp6s_pmtuchg); 1162 } 1163 } 1164 1165 /* 1166 * Process a Node Information Query packet, based on 1167 * draft-ietf-ipngwg-icmp-name-lookups-07. 1168 * 1169 * Spec incompatibilities: 1170 * - IPv6 Subject address handling 1171 * - IPv4 Subject address handling support missing 1172 * - Proxy reply (answer even if it's not for me) 1173 * - joins NI group address at in6_ifattach() time only, does not cope 1174 * with hostname changes by sethostname(3) 1175 */ 1176 static struct mbuf * 1177 ni6_input(struct mbuf *m, int off, struct prison *pr) 1178 { 1179 struct icmp6_nodeinfo *ni6, *nni6; 1180 struct mbuf *n = NULL; 1181 u_int16_t qtype; 1182 int subjlen; 1183 int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); 1184 struct ni_reply_fqdn *fqdn; 1185 int addrs; /* for NI_QTYPE_NODEADDR */ 1186 struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */ 1187 struct in6_addr in6_subj; /* subject address */ 1188 struct ip6_hdr *ip6; 1189 int oldfqdn = 0; /* if 1, return pascal string (03 draft) */ 1190 char *subj = NULL; 1191 struct in6_ifaddr *ia6 = NULL; 1192 1193 ip6 = mtod(m, struct ip6_hdr *); 1194 ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off); 1195 1196 /* 1197 * Validate IPv6 source address. 1198 * The default configuration MUST be to refuse answering queries from 1199 * global-scope addresses according to RFC4602. 1200 * Notes: 1201 * - it's not very clear what "refuse" means; this implementation 1202 * simply drops it. 1203 * - it's not very easy to identify global-scope (unicast) addresses 1204 * since there are many prefixes for them. It should be safer 1205 * and in practice sufficient to check "all" but loopback and 1206 * link-local (note that site-local unicast was deprecated and 1207 * ULA is defined as global scope-wise) 1208 */ 1209 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_GLOBALOK) == 0 && 1210 !IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) && 1211 !IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) 1212 goto bad; 1213 1214 /* 1215 * Validate IPv6 destination address. 1216 * 1217 * The Responder must discard the Query without further processing 1218 * unless it is one of the Responder's unicast or anycast addresses, or 1219 * a link-local scope multicast address which the Responder has joined. 1220 * [RFC4602, Section 5.] 1221 */ 1222 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 1223 if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst)) 1224 goto bad; 1225 /* else it's a link-local multicast, fine */ 1226 } else { /* unicast or anycast */ 1227 ia6 = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */, false); 1228 if (ia6 == NULL) 1229 goto bad; /* XXX impossible */ 1230 1231 if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) && 1232 !(V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK)) { 1233 nd6log((LOG_DEBUG, "ni6_input: ignore node info to " 1234 "a temporary address in %s:%d", 1235 __FILE__, __LINE__)); 1236 goto bad; 1237 } 1238 } 1239 1240 /* validate query Subject field. */ 1241 qtype = ntohs(ni6->ni_qtype); 1242 subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo); 1243 switch (qtype) { 1244 case NI_QTYPE_NOOP: 1245 case NI_QTYPE_SUPTYPES: 1246 /* 07 draft */ 1247 if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0) 1248 break; 1249 /* FALLTHROUGH */ 1250 case NI_QTYPE_FQDN: 1251 case NI_QTYPE_NODEADDR: 1252 case NI_QTYPE_IPV4ADDR: 1253 switch (ni6->ni_code) { 1254 case ICMP6_NI_SUBJ_IPV6: 1255 #if ICMP6_NI_SUBJ_IPV6 != 0 1256 case 0: 1257 #endif 1258 /* 1259 * backward compatibility - try to accept 03 draft 1260 * format, where no Subject is present. 1261 */ 1262 if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 && 1263 subjlen == 0) { 1264 oldfqdn++; 1265 break; 1266 } 1267 #if ICMP6_NI_SUBJ_IPV6 != 0 1268 if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6) 1269 goto bad; 1270 #endif 1271 1272 if (subjlen != sizeof(struct in6_addr)) 1273 goto bad; 1274 1275 /* 1276 * Validate Subject address. 1277 * 1278 * Not sure what exactly "address belongs to the node" 1279 * means in the spec, is it just unicast, or what? 1280 * 1281 * At this moment we consider Subject address as 1282 * "belong to the node" if the Subject address equals 1283 * to the IPv6 destination address; validation for 1284 * IPv6 destination address should have done enough 1285 * check for us. 1286 * 1287 * We do not do proxy at this moment. 1288 */ 1289 m_copydata(m, off + sizeof(struct icmp6_nodeinfo), 1290 subjlen, (caddr_t)&in6_subj); 1291 if (in6_setscope(&in6_subj, m->m_pkthdr.rcvif, NULL)) 1292 goto bad; 1293 1294 subj = (char *)&in6_subj; 1295 if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &in6_subj)) 1296 break; 1297 1298 /* 1299 * XXX if we are to allow other cases, we should really 1300 * be careful about scope here. 1301 * basically, we should disallow queries toward IPv6 1302 * destination X with subject Y, 1303 * if scope(X) > scope(Y). 1304 * if we allow scope(X) > scope(Y), it will result in 1305 * information leakage across scope boundary. 1306 */ 1307 goto bad; 1308 1309 case ICMP6_NI_SUBJ_FQDN: 1310 /* 1311 * Validate Subject name with gethostname(3). 1312 * 1313 * The behavior may need some debate, since: 1314 * - we are not sure if the node has FQDN as 1315 * hostname (returned by gethostname(3)). 1316 * - the code does wildcard match for truncated names. 1317 * however, we are not sure if we want to perform 1318 * wildcard match, if gethostname(3) side has 1319 * truncated hostname. 1320 */ 1321 mtx_lock(&pr->pr_mtx); 1322 n = ni6_nametodns(pr->pr_hostname, 1323 strlen(pr->pr_hostname), 0); 1324 mtx_unlock(&pr->pr_mtx); 1325 if (!n || n->m_next || n->m_len == 0) 1326 goto bad; 1327 if (m->m_len < off + sizeof(struct icmp6_nodeinfo) + 1328 subjlen) { 1329 m = m_pullup(m, off + 1330 sizeof(struct icmp6_nodeinfo) + subjlen); 1331 if (m == NULL) { 1332 IP6STAT_INC(ip6s_exthdrtoolong); 1333 goto bad; 1334 } 1335 } 1336 /* ip6 possibly invalid but not used after. */ 1337 ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off); 1338 subj = (char *)(mtod(m, caddr_t) + off + 1339 sizeof(struct icmp6_nodeinfo)); 1340 if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *), 1341 n->m_len)) { 1342 goto bad; 1343 } 1344 m_freem(n); 1345 n = NULL; 1346 break; 1347 1348 case ICMP6_NI_SUBJ_IPV4: /* XXX: to be implemented? */ 1349 default: 1350 goto bad; 1351 } 1352 break; 1353 } 1354 1355 /* refuse based on configuration. XXX ICMP6_NI_REFUSED? */ 1356 switch (qtype) { 1357 case NI_QTYPE_FQDN: 1358 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_FQDNOK) == 0) 1359 goto bad; 1360 break; 1361 case NI_QTYPE_NODEADDR: 1362 case NI_QTYPE_IPV4ADDR: 1363 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_NODEADDROK) == 0) 1364 goto bad; 1365 break; 1366 } 1367 1368 /* guess reply length */ 1369 switch (qtype) { 1370 case NI_QTYPE_NOOP: 1371 break; /* no reply data */ 1372 case NI_QTYPE_SUPTYPES: 1373 replylen += sizeof(u_int32_t); 1374 break; 1375 case NI_QTYPE_FQDN: 1376 /* XXX will append an mbuf */ 1377 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); 1378 break; 1379 case NI_QTYPE_NODEADDR: 1380 addrs = ni6_addrs(ni6, m, &ifp, (struct in6_addr *)subj); 1381 if ((replylen += addrs * (sizeof(struct in6_addr) + 1382 sizeof(u_int32_t))) > MCLBYTES) 1383 replylen = MCLBYTES; /* XXX: will truncate pkt later */ 1384 break; 1385 case NI_QTYPE_IPV4ADDR: 1386 /* unsupported - should respond with unknown Qtype? */ 1387 break; 1388 default: 1389 /* 1390 * XXX: We must return a reply with the ICMP6 code 1391 * `unknown Qtype' in this case. However we regard the case 1392 * as an FQDN query for backward compatibility. 1393 * Older versions set a random value to this field, 1394 * so it rarely varies in the defined qtypes. 1395 * But the mechanism is not reliable... 1396 * maybe we should obsolete older versions. 1397 */ 1398 qtype = NI_QTYPE_FQDN; 1399 /* XXX will append an mbuf */ 1400 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); 1401 oldfqdn++; 1402 break; 1403 } 1404 1405 /* Allocate an mbuf to reply. */ 1406 if (replylen > MCLBYTES) { 1407 /* 1408 * XXX: should we try to allocate more? But MCLBYTES 1409 * is probably much larger than IPV6_MMTU... 1410 */ 1411 goto bad; 1412 } 1413 if (replylen > MHLEN) 1414 n = m_getcl(M_NOWAIT, m->m_type, M_PKTHDR); 1415 else 1416 n = m_gethdr(M_NOWAIT, m->m_type); 1417 if (n == NULL) { 1418 m_freem(m); 1419 return (NULL); 1420 } 1421 m_move_pkthdr(n, m); /* just for recvif and FIB */ 1422 n->m_pkthdr.len = n->m_len = replylen; 1423 1424 /* copy mbuf header and IPv6 + Node Information base headers */ 1425 bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr)); 1426 nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1); 1427 bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo)); 1428 1429 /* qtype dependent procedure */ 1430 switch (qtype) { 1431 case NI_QTYPE_NOOP: 1432 nni6->ni_code = ICMP6_NI_SUCCESS; 1433 nni6->ni_flags = 0; 1434 break; 1435 case NI_QTYPE_SUPTYPES: 1436 { 1437 u_int32_t v; 1438 nni6->ni_code = ICMP6_NI_SUCCESS; 1439 nni6->ni_flags = htons(0x0000); /* raw bitmap */ 1440 /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */ 1441 v = (u_int32_t)htonl(0x0000000f); 1442 bcopy(&v, nni6 + 1, sizeof(u_int32_t)); 1443 break; 1444 } 1445 case NI_QTYPE_FQDN: 1446 nni6->ni_code = ICMP6_NI_SUCCESS; 1447 fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) + 1448 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo)); 1449 nni6->ni_flags = 0; /* XXX: meaningless TTL */ 1450 fqdn->ni_fqdn_ttl = 0; /* ditto. */ 1451 /* 1452 * XXX do we really have FQDN in hostname? 1453 */ 1454 mtx_lock(&pr->pr_mtx); 1455 n->m_next = ni6_nametodns(pr->pr_hostname, 1456 strlen(pr->pr_hostname), oldfqdn); 1457 mtx_unlock(&pr->pr_mtx); 1458 if (n->m_next == NULL) 1459 goto bad; 1460 /* XXX we assume that n->m_next is not a chain */ 1461 if (n->m_next->m_next != NULL) 1462 goto bad; 1463 n->m_pkthdr.len += n->m_next->m_len; 1464 break; 1465 case NI_QTYPE_NODEADDR: 1466 { 1467 int lenlim, copied; 1468 1469 nni6->ni_code = ICMP6_NI_SUCCESS; 1470 n->m_pkthdr.len = n->m_len = 1471 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); 1472 lenlim = M_TRAILINGSPACE(n); 1473 copied = ni6_store_addrs(ni6, nni6, ifp, lenlim); 1474 /* XXX: reset mbuf length */ 1475 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + 1476 sizeof(struct icmp6_nodeinfo) + copied; 1477 break; 1478 } 1479 default: 1480 break; /* XXX impossible! */ 1481 } 1482 1483 nni6->ni_type = ICMP6_NI_REPLY; 1484 m_freem(m); 1485 return (n); 1486 1487 bad: 1488 m_freem(m); 1489 if (n) 1490 m_freem(n); 1491 return (NULL); 1492 } 1493 1494 /* 1495 * make a mbuf with DNS-encoded string. no compression support. 1496 * 1497 * XXX names with less than 2 dots (like "foo" or "foo.section") will be 1498 * treated as truncated name (two \0 at the end). this is a wild guess. 1499 * 1500 * old - return pascal string if non-zero 1501 */ 1502 static struct mbuf * 1503 ni6_nametodns(const char *name, int namelen, int old) 1504 { 1505 struct mbuf *m; 1506 char *cp, *ep; 1507 const char *p, *q; 1508 int i, len, nterm; 1509 1510 if (old) 1511 len = namelen + 1; 1512 else 1513 len = MCLBYTES; 1514 1515 /* Because MAXHOSTNAMELEN is usually 256, we use cluster mbuf. */ 1516 if (len > MLEN) 1517 m = m_getcl(M_NOWAIT, MT_DATA, 0); 1518 else 1519 m = m_get(M_NOWAIT, MT_DATA); 1520 if (m == NULL) 1521 goto fail; 1522 1523 if (old) { 1524 m->m_len = len; 1525 *mtod(m, char *) = namelen; 1526 bcopy(name, mtod(m, char *) + 1, namelen); 1527 return m; 1528 } else { 1529 m->m_len = 0; 1530 cp = mtod(m, char *); 1531 ep = mtod(m, char *) + M_TRAILINGSPACE(m); 1532 1533 /* if not certain about my name, return empty buffer */ 1534 if (namelen == 0) 1535 return m; 1536 1537 /* 1538 * guess if it looks like shortened hostname, or FQDN. 1539 * shortened hostname needs two trailing "\0". 1540 */ 1541 i = 0; 1542 for (p = name; p < name + namelen; p++) { 1543 if (*p && *p == '.') 1544 i++; 1545 } 1546 if (i < 2) 1547 nterm = 2; 1548 else 1549 nterm = 1; 1550 1551 p = name; 1552 while (cp < ep && p < name + namelen) { 1553 i = 0; 1554 for (q = p; q < name + namelen && *q && *q != '.'; q++) 1555 i++; 1556 /* result does not fit into mbuf */ 1557 if (cp + i + 1 >= ep) 1558 goto fail; 1559 /* 1560 * DNS label length restriction, RFC1035 page 8. 1561 * "i == 0" case is included here to avoid returning 1562 * 0-length label on "foo..bar". 1563 */ 1564 if (i <= 0 || i >= 64) 1565 goto fail; 1566 *cp++ = i; 1567 bcopy(p, cp, i); 1568 cp += i; 1569 p = q; 1570 if (p < name + namelen && *p == '.') 1571 p++; 1572 } 1573 /* termination */ 1574 if (cp + nterm >= ep) 1575 goto fail; 1576 while (nterm-- > 0) 1577 *cp++ = '\0'; 1578 m->m_len = cp - mtod(m, char *); 1579 return m; 1580 } 1581 1582 panic("should not reach here"); 1583 /* NOTREACHED */ 1584 1585 fail: 1586 if (m) 1587 m_freem(m); 1588 return NULL; 1589 } 1590 1591 /* 1592 * check if two DNS-encoded string matches. takes care of truncated 1593 * form (with \0\0 at the end). no compression support. 1594 * XXX upper/lowercase match (see RFC2065) 1595 */ 1596 static int 1597 ni6_dnsmatch(const char *a, int alen, const char *b, int blen) 1598 { 1599 const char *a0, *b0; 1600 int l; 1601 1602 /* simplest case - need validation? */ 1603 if (alen == blen && bcmp(a, b, alen) == 0) 1604 return 1; 1605 1606 a0 = a; 1607 b0 = b; 1608 1609 /* termination is mandatory */ 1610 if (alen < 2 || blen < 2) 1611 return 0; 1612 if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0') 1613 return 0; 1614 alen--; 1615 blen--; 1616 1617 while (a - a0 < alen && b - b0 < blen) { 1618 if (a - a0 + 1 > alen || b - b0 + 1 > blen) 1619 return 0; 1620 1621 if ((signed char)a[0] < 0 || (signed char)b[0] < 0) 1622 return 0; 1623 /* we don't support compression yet */ 1624 if (a[0] >= 64 || b[0] >= 64) 1625 return 0; 1626 1627 /* truncated case */ 1628 if (a[0] == 0 && a - a0 == alen - 1) 1629 return 1; 1630 if (b[0] == 0 && b - b0 == blen - 1) 1631 return 1; 1632 if (a[0] == 0 || b[0] == 0) 1633 return 0; 1634 1635 if (a[0] != b[0]) 1636 return 0; 1637 l = a[0]; 1638 if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen) 1639 return 0; 1640 if (bcmp(a + 1, b + 1, l) != 0) 1641 return 0; 1642 1643 a += 1 + l; 1644 b += 1 + l; 1645 } 1646 1647 if (a - a0 == alen && b - b0 == blen) 1648 return 1; 1649 else 1650 return 0; 1651 } 1652 1653 /* 1654 * calculate the number of addresses to be returned in the node info reply. 1655 */ 1656 static int 1657 ni6_addrs(struct icmp6_nodeinfo *ni6, struct mbuf *m, struct ifnet **ifpp, 1658 struct in6_addr *subj) 1659 { 1660 struct ifnet *ifp; 1661 struct in6_ifaddr *ifa6; 1662 struct ifaddr *ifa; 1663 int addrs = 0, addrsofif, iffound = 0; 1664 int niflags = ni6->ni_flags; 1665 1666 NET_EPOCH_ASSERT(); 1667 1668 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) { 1669 switch (ni6->ni_code) { 1670 case ICMP6_NI_SUBJ_IPV6: 1671 if (subj == NULL) /* must be impossible... */ 1672 return (0); 1673 break; 1674 default: 1675 /* 1676 * XXX: we only support IPv6 subject address for 1677 * this Qtype. 1678 */ 1679 return (0); 1680 } 1681 } 1682 1683 CK_STAILQ_FOREACH(ifp, &V_ifnet, if_link) { 1684 addrsofif = 0; 1685 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 1686 if (ifa->ifa_addr->sa_family != AF_INET6) 1687 continue; 1688 ifa6 = (struct in6_ifaddr *)ifa; 1689 1690 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 && 1691 IN6_ARE_ADDR_EQUAL(subj, &ifa6->ia_addr.sin6_addr)) 1692 iffound = 1; 1693 1694 /* 1695 * IPv4-mapped addresses can only be returned by a 1696 * Node Information proxy, since they represent 1697 * addresses of IPv4-only nodes, which perforce do 1698 * not implement this protocol. 1699 * [icmp-name-lookups-07, Section 5.4] 1700 * So we don't support NI_NODEADDR_FLAG_COMPAT in 1701 * this function at this moment. 1702 */ 1703 1704 /* What do we have to do about ::1? */ 1705 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { 1706 case IPV6_ADDR_SCOPE_LINKLOCAL: 1707 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) 1708 continue; 1709 break; 1710 case IPV6_ADDR_SCOPE_SITELOCAL: 1711 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) 1712 continue; 1713 break; 1714 case IPV6_ADDR_SCOPE_GLOBAL: 1715 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) 1716 continue; 1717 break; 1718 default: 1719 continue; 1720 } 1721 1722 /* 1723 * check if anycast is okay. 1724 * XXX: just experimental. not in the spec. 1725 */ 1726 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && 1727 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) 1728 continue; /* we need only unicast addresses */ 1729 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && 1730 (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) { 1731 continue; 1732 } 1733 addrsofif++; /* count the address */ 1734 } 1735 if (iffound) { 1736 *ifpp = ifp; 1737 return (addrsofif); 1738 } 1739 1740 addrs += addrsofif; 1741 } 1742 1743 return (addrs); 1744 } 1745 1746 static int 1747 ni6_store_addrs(struct icmp6_nodeinfo *ni6, struct icmp6_nodeinfo *nni6, 1748 struct ifnet *ifp0, int resid) 1749 { 1750 struct ifnet *ifp; 1751 struct in6_ifaddr *ifa6; 1752 struct ifaddr *ifa; 1753 struct ifnet *ifp_dep = NULL; 1754 int copied = 0, allow_deprecated = 0; 1755 u_char *cp = (u_char *)(nni6 + 1); 1756 int niflags = ni6->ni_flags; 1757 u_int32_t ltime; 1758 1759 NET_EPOCH_ASSERT(); 1760 1761 if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL)) 1762 return (0); /* needless to copy */ 1763 1764 ifp = ifp0 ? ifp0 : CK_STAILQ_FIRST(&V_ifnet); 1765 again: 1766 1767 for (; ifp; ifp = CK_STAILQ_NEXT(ifp, if_link)) { 1768 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 1769 if (ifa->ifa_addr->sa_family != AF_INET6) 1770 continue; 1771 ifa6 = (struct in6_ifaddr *)ifa; 1772 1773 if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 && 1774 allow_deprecated == 0) { 1775 /* 1776 * prefererred address should be put before 1777 * deprecated addresses. 1778 */ 1779 1780 /* record the interface for later search */ 1781 if (ifp_dep == NULL) 1782 ifp_dep = ifp; 1783 1784 continue; 1785 } else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 && 1786 allow_deprecated != 0) 1787 continue; /* we now collect deprecated addrs */ 1788 1789 /* What do we have to do about ::1? */ 1790 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { 1791 case IPV6_ADDR_SCOPE_LINKLOCAL: 1792 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) 1793 continue; 1794 break; 1795 case IPV6_ADDR_SCOPE_SITELOCAL: 1796 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) 1797 continue; 1798 break; 1799 case IPV6_ADDR_SCOPE_GLOBAL: 1800 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) 1801 continue; 1802 break; 1803 default: 1804 continue; 1805 } 1806 1807 /* 1808 * check if anycast is okay. 1809 * XXX: just experimental. not in the spec. 1810 */ 1811 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && 1812 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) 1813 continue; 1814 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && 1815 (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) { 1816 continue; 1817 } 1818 1819 /* now we can copy the address */ 1820 if (resid < sizeof(struct in6_addr) + 1821 sizeof(u_int32_t)) { 1822 /* 1823 * We give up much more copy. 1824 * Set the truncate flag and return. 1825 */ 1826 nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE; 1827 return (copied); 1828 } 1829 1830 /* 1831 * Set the TTL of the address. 1832 * The TTL value should be one of the following 1833 * according to the specification: 1834 * 1835 * 1. The remaining lifetime of a DHCP lease on the 1836 * address, or 1837 * 2. The remaining Valid Lifetime of a prefix from 1838 * which the address was derived through Stateless 1839 * Autoconfiguration. 1840 * 1841 * Note that we currently do not support stateful 1842 * address configuration by DHCPv6, so the former 1843 * case can't happen. 1844 */ 1845 if (ifa6->ia6_lifetime.ia6t_expire == 0) 1846 ltime = ND6_INFINITE_LIFETIME; 1847 else { 1848 if (ifa6->ia6_lifetime.ia6t_expire > 1849 time_uptime) 1850 ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_uptime); 1851 else 1852 ltime = 0; 1853 } 1854 1855 bcopy(<ime, cp, sizeof(u_int32_t)); 1856 cp += sizeof(u_int32_t); 1857 1858 /* copy the address itself */ 1859 bcopy(&ifa6->ia_addr.sin6_addr, cp, 1860 sizeof(struct in6_addr)); 1861 in6_clearscope((struct in6_addr *)cp); /* XXX */ 1862 cp += sizeof(struct in6_addr); 1863 1864 resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t)); 1865 copied += (sizeof(struct in6_addr) + sizeof(u_int32_t)); 1866 } 1867 if (ifp0) /* we need search only on the specified IF */ 1868 break; 1869 } 1870 1871 if (allow_deprecated == 0 && ifp_dep != NULL) { 1872 ifp = ifp_dep; 1873 allow_deprecated = 1; 1874 1875 goto again; 1876 } 1877 1878 return (copied); 1879 } 1880 1881 static bool 1882 icmp6_rip6_match(const struct inpcb *inp, void *v) 1883 { 1884 struct ip6_hdr *ip6 = v; 1885 1886 if ((inp->inp_vflag & INP_IPV6) == 0) 1887 return (false); 1888 if (inp->inp_ip_p != IPPROTO_ICMPV6) 1889 return (false); 1890 if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr) && 1891 !IN6_ARE_ADDR_EQUAL(&inp->in6p_laddr, &ip6->ip6_dst)) 1892 return (false); 1893 if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr) && 1894 !IN6_ARE_ADDR_EQUAL(&inp->in6p_faddr, &ip6->ip6_src)) 1895 return (false); 1896 return (true); 1897 } 1898 1899 /* 1900 * XXX almost dup'ed code with rip6_input. 1901 */ 1902 static int 1903 icmp6_rip6_input(struct mbuf **mp, int off) 1904 { 1905 struct mbuf *n, *m = *mp; 1906 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1907 struct inpcb_iterator inpi = INP_ITERATOR(&V_ripcbinfo, 1908 INPLOOKUP_RLOCKPCB, icmp6_rip6_match, ip6); 1909 struct inpcb *inp; 1910 struct sockaddr_in6 fromsa; 1911 struct icmp6_hdr *icmp6; 1912 struct mbuf *opts = NULL; 1913 int delivered = 0; 1914 1915 /* This is assumed to be safe; icmp6_input() does a pullup. */ 1916 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off); 1917 1918 /* 1919 * XXX: the address may have embedded scope zone ID, which should be 1920 * hidden from applications. 1921 */ 1922 bzero(&fromsa, sizeof(fromsa)); 1923 fromsa.sin6_family = AF_INET6; 1924 fromsa.sin6_len = sizeof(struct sockaddr_in6); 1925 fromsa.sin6_addr = ip6->ip6_src; 1926 if (sa6_recoverscope(&fromsa)) { 1927 m_freem(m); 1928 *mp = NULL; 1929 return (IPPROTO_DONE); 1930 } 1931 1932 while ((inp = inp_next(&inpi)) != NULL) { 1933 if (ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type, 1934 inp->in6p_icmp6filt)) 1935 continue; 1936 /* 1937 * Recent network drivers tend to allocate a single 1938 * mbuf cluster, rather than to make a couple of 1939 * mbufs without clusters. Also, since the IPv6 code 1940 * path tries to avoid m_pullup(), it is highly 1941 * probable that we still have an mbuf cluster here 1942 * even though the necessary length can be stored in an 1943 * mbuf's internal buffer. 1944 * Meanwhile, the default size of the receive socket 1945 * buffer for raw sockets is not so large. This means 1946 * the possibility of packet loss is relatively higher 1947 * than before. To avoid this scenario, we copy the 1948 * received data to a separate mbuf that does not use 1949 * a cluster, if possible. 1950 * XXX: it is better to copy the data after stripping 1951 * intermediate headers. 1952 */ 1953 if ((m->m_flags & M_EXT) && m->m_next == NULL && 1954 m->m_len <= MHLEN) { 1955 n = m_get(M_NOWAIT, m->m_type); 1956 if (n != NULL) { 1957 if (m_dup_pkthdr(n, m, M_NOWAIT)) { 1958 bcopy(m->m_data, n->m_data, m->m_len); 1959 n->m_len = m->m_len; 1960 } else { 1961 m_free(n); 1962 n = NULL; 1963 } 1964 } 1965 } else 1966 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 1967 if (n == NULL) 1968 continue; 1969 if (inp->inp_flags & INP_CONTROLOPTS) 1970 ip6_savecontrol(inp, n, &opts); 1971 /* strip intermediate headers */ 1972 m_adj(n, off); 1973 SOCKBUF_LOCK(&inp->inp_socket->so_rcv); 1974 if (sbappendaddr_locked(&inp->inp_socket->so_rcv, 1975 (struct sockaddr *)&fromsa, n, opts) == 0) { 1976 soroverflow_locked(inp->inp_socket); 1977 m_freem(n); 1978 if (opts) 1979 m_freem(opts); 1980 } else { 1981 sorwakeup_locked(inp->inp_socket); 1982 delivered++; 1983 } 1984 opts = NULL; 1985 } 1986 m_freem(m); 1987 *mp = NULL; 1988 if (delivered == 0) 1989 IP6STAT_DEC(ip6s_delivered); 1990 return (IPPROTO_DONE); 1991 } 1992 1993 /* 1994 * Reflect the ip6 packet back to the source. 1995 * OFF points to the icmp6 header, counted from the top of the mbuf. 1996 */ 1997 static void 1998 icmp6_reflect(struct mbuf *m, size_t off) 1999 { 2000 struct in6_addr src6, *srcp; 2001 struct ip6_hdr *ip6; 2002 struct icmp6_hdr *icmp6; 2003 struct in6_ifaddr *ia = NULL; 2004 struct ifnet *outif = NULL; 2005 int plen; 2006 int type, code, hlim; 2007 2008 /* too short to reflect */ 2009 if (off < sizeof(struct ip6_hdr)) { 2010 nd6log((LOG_DEBUG, 2011 "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n", 2012 (u_long)off, (u_long)sizeof(struct ip6_hdr), 2013 __FILE__, __LINE__)); 2014 goto bad; 2015 } 2016 2017 /* 2018 * If there are extra headers between IPv6 and ICMPv6, strip 2019 * off that header first. 2020 */ 2021 #ifdef DIAGNOSTIC 2022 if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN) 2023 panic("assumption failed in icmp6_reflect"); 2024 #endif 2025 if (off > sizeof(struct ip6_hdr)) { 2026 size_t l; 2027 struct ip6_hdr nip6; 2028 2029 l = off - sizeof(struct ip6_hdr); 2030 m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6); 2031 m_adj(m, l); 2032 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 2033 if (m->m_len < l) { 2034 if ((m = m_pullup(m, l)) == NULL) 2035 return; 2036 } 2037 bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6)); 2038 } else /* off == sizeof(struct ip6_hdr) */ { 2039 size_t l; 2040 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 2041 if (m->m_len < l) { 2042 if ((m = m_pullup(m, l)) == NULL) 2043 return; 2044 } 2045 } 2046 plen = m->m_pkthdr.len - sizeof(struct ip6_hdr); 2047 ip6 = mtod(m, struct ip6_hdr *); 2048 ip6->ip6_nxt = IPPROTO_ICMPV6; 2049 icmp6 = (struct icmp6_hdr *)(ip6 + 1); 2050 type = icmp6->icmp6_type; /* keep type for statistics */ 2051 code = icmp6->icmp6_code; /* ditto. */ 2052 hlim = 0; 2053 srcp = NULL; 2054 2055 /* 2056 * If the incoming packet was addressed directly to us (i.e. unicast), 2057 * use dst as the src for the reply. 2058 * The IN6_IFF_NOTREADY case should be VERY rare, but is possible 2059 * (for example) when we encounter an error while forwarding procedure 2060 * destined to a duplicated address of ours. 2061 */ 2062 if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 2063 ia = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */, false); 2064 if (ia != NULL && !(ia->ia6_flags & 2065 (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) { 2066 src6 = ia->ia_addr.sin6_addr; 2067 srcp = &src6; 2068 2069 if (m->m_pkthdr.rcvif != NULL) { 2070 /* XXX: This may not be the outgoing interface */ 2071 hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim; 2072 } else 2073 hlim = V_ip6_defhlim; 2074 } 2075 } 2076 2077 if (srcp == NULL) { 2078 int error; 2079 struct in6_addr dst6; 2080 uint32_t scopeid; 2081 2082 /* 2083 * This case matches to multicasts, our anycast, or unicasts 2084 * that we do not own. Select a source address based on the 2085 * source address of the erroneous packet. 2086 */ 2087 in6_splitscope(&ip6->ip6_src, &dst6, &scopeid); 2088 error = in6_selectsrc_addr(M_GETFIB(m), &dst6, 2089 scopeid, NULL, &src6, &hlim); 2090 2091 if (error) { 2092 char ip6buf[INET6_ADDRSTRLEN]; 2093 nd6log((LOG_DEBUG, 2094 "icmp6_reflect: source can't be determined: " 2095 "dst=%s, error=%d\n", 2096 ip6_sprintf(ip6buf, &ip6->ip6_dst), error)); 2097 goto bad; 2098 } 2099 srcp = &src6; 2100 } 2101 /* 2102 * ip6_input() drops a packet if its src is multicast. 2103 * So, the src is never multicast. 2104 */ 2105 ip6->ip6_dst = ip6->ip6_src; 2106 ip6->ip6_src = *srcp; 2107 ip6->ip6_flow = 0; 2108 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2109 ip6->ip6_vfc |= IPV6_VERSION; 2110 ip6->ip6_nxt = IPPROTO_ICMPV6; 2111 ip6->ip6_hlim = hlim; 2112 2113 icmp6->icmp6_cksum = 0; 2114 icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2115 sizeof(struct ip6_hdr), plen); 2116 2117 /* 2118 * XXX option handling 2119 */ 2120 2121 m->m_flags &= ~(M_BCAST|M_MCAST); 2122 m->m_pkthdr.rcvif = NULL; 2123 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2124 if (outif) 2125 icmp6_ifoutstat_inc(outif, type, code); 2126 2127 return; 2128 2129 bad: 2130 m_freem(m); 2131 return; 2132 } 2133 2134 void 2135 icmp6_fasttimo(void) 2136 { 2137 2138 mld_fasttimo(); 2139 } 2140 2141 void 2142 icmp6_slowtimo(void) 2143 { 2144 2145 mld_slowtimo(); 2146 } 2147 2148 static const char * 2149 icmp6_redirect_diag(struct in6_addr *src6, struct in6_addr *dst6, 2150 struct in6_addr *tgt6) 2151 { 2152 static char buf[1024]; 2153 char ip6bufs[INET6_ADDRSTRLEN]; 2154 char ip6bufd[INET6_ADDRSTRLEN]; 2155 char ip6buft[INET6_ADDRSTRLEN]; 2156 snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)", 2157 ip6_sprintf(ip6bufs, src6), ip6_sprintf(ip6bufd, dst6), 2158 ip6_sprintf(ip6buft, tgt6)); 2159 return buf; 2160 } 2161 2162 void 2163 icmp6_redirect_input(struct mbuf *m, int off) 2164 { 2165 struct ifnet *ifp; 2166 struct ip6_hdr *ip6; 2167 struct nd_redirect *nd_rd; 2168 struct in6_addr src6, redtgt6, reddst6; 2169 union nd_opts ndopts; 2170 char ip6buf[INET6_ADDRSTRLEN]; 2171 char *lladdr; 2172 int icmp6len, is_onlink, is_router, lladdrlen; 2173 2174 M_ASSERTPKTHDR(m); 2175 KASSERT(m->m_pkthdr.rcvif != NULL, ("%s: no rcvif", __func__)); 2176 2177 /* XXX if we are router, we don't update route by icmp6 redirect */ 2178 if (V_ip6_forwarding) 2179 goto freeit; 2180 if (!V_icmp6_rediraccept) 2181 goto freeit; 2182 2183 /* RFC 6980: Nodes MUST silently ignore fragments */ 2184 if(m->m_flags & M_FRAGMENTED) 2185 goto freeit; 2186 2187 ip6 = mtod(m, struct ip6_hdr *); 2188 icmp6len = ntohs(ip6->ip6_plen); 2189 if (m->m_len < off + icmp6len) { 2190 m = m_pullup(m, off + icmp6len); 2191 if (m == NULL) { 2192 IP6STAT_INC(ip6s_exthdrtoolong); 2193 return; 2194 } 2195 } 2196 ip6 = mtod(m, struct ip6_hdr *); 2197 nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off); 2198 2199 ifp = m->m_pkthdr.rcvif; 2200 redtgt6 = nd_rd->nd_rd_target; 2201 reddst6 = nd_rd->nd_rd_dst; 2202 2203 if (in6_setscope(&redtgt6, ifp, NULL) || 2204 in6_setscope(&reddst6, ifp, NULL)) { 2205 goto freeit; 2206 } 2207 2208 /* validation */ 2209 src6 = ip6->ip6_src; 2210 if (!IN6_IS_ADDR_LINKLOCAL(&src6)) { 2211 nd6log((LOG_ERR, 2212 "ICMP6 redirect sent from %s rejected; " 2213 "must be from linklocal\n", 2214 ip6_sprintf(ip6buf, &src6))); 2215 goto bad; 2216 } 2217 if (__predict_false(ip6->ip6_hlim != 255)) { 2218 ICMP6STAT_INC(icp6s_invlhlim); 2219 nd6log((LOG_ERR, 2220 "ICMP6 redirect sent from %s rejected; " 2221 "hlim=%d (must be 255)\n", 2222 ip6_sprintf(ip6buf, &src6), ip6->ip6_hlim)); 2223 goto bad; 2224 } 2225 { 2226 /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */ 2227 struct nhop_object *nh; 2228 struct in6_addr kdst; 2229 uint32_t scopeid; 2230 2231 in6_splitscope(&reddst6, &kdst, &scopeid); 2232 NET_EPOCH_ASSERT(); 2233 nh = fib6_lookup(ifp->if_fib, &kdst, scopeid, 0, 0); 2234 if (nh != NULL) { 2235 struct in6_addr nh_addr; 2236 nh_addr = ifatoia6(nh->nh_ifa)->ia_addr.sin6_addr; 2237 if ((nh->nh_flags & NHF_GATEWAY) == 0) { 2238 nd6log((LOG_ERR, 2239 "ICMP6 redirect rejected; no route " 2240 "with inet6 gateway found for redirect dst: %s\n", 2241 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2242 goto bad; 2243 } 2244 2245 /* 2246 * Embed scope zone id into next hop address. 2247 */ 2248 nh_addr = nh->gw6_sa.sin6_addr; 2249 2250 if (IN6_ARE_ADDR_EQUAL(&src6, &nh_addr) == 0) { 2251 nd6log((LOG_ERR, 2252 "ICMP6 redirect rejected; " 2253 "not equal to gw-for-src=%s (must be same): " 2254 "%s\n", 2255 ip6_sprintf(ip6buf, &nh_addr), 2256 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2257 goto bad; 2258 } 2259 } else { 2260 nd6log((LOG_ERR, 2261 "ICMP6 redirect rejected; " 2262 "no route found for redirect dst: %s\n", 2263 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2264 goto bad; 2265 } 2266 } 2267 if (IN6_IS_ADDR_MULTICAST(&reddst6)) { 2268 nd6log((LOG_ERR, 2269 "ICMP6 redirect rejected; " 2270 "redirect dst must be unicast: %s\n", 2271 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2272 goto bad; 2273 } 2274 2275 is_router = is_onlink = 0; 2276 if (IN6_IS_ADDR_LINKLOCAL(&redtgt6)) 2277 is_router = 1; /* router case */ 2278 if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0) 2279 is_onlink = 1; /* on-link destination case */ 2280 if (!is_router && !is_onlink) { 2281 nd6log((LOG_ERR, 2282 "ICMP6 redirect rejected; " 2283 "neither router case nor onlink case: %s\n", 2284 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2285 goto bad; 2286 } 2287 2288 icmp6len -= sizeof(*nd_rd); 2289 nd6_option_init(nd_rd + 1, icmp6len, &ndopts); 2290 if (nd6_options(&ndopts) < 0) { 2291 nd6log((LOG_INFO, "%s: invalid ND option, rejected: %s\n", 2292 __func__, icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2293 /* nd6_options have incremented stats */ 2294 goto freeit; 2295 } 2296 2297 lladdr = NULL; 2298 lladdrlen = 0; 2299 if (ndopts.nd_opts_tgt_lladdr) { 2300 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 2301 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 2302 } 2303 2304 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 2305 nd6log((LOG_INFO, "%s: lladdrlen mismatch for %s " 2306 "(if %d, icmp6 packet %d): %s\n", 2307 __func__, ip6_sprintf(ip6buf, &redtgt6), 2308 ifp->if_addrlen, lladdrlen - 2, 2309 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2310 goto bad; 2311 } 2312 2313 /* Validation passed. */ 2314 2315 /* RFC 2461 8.3 */ 2316 nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT, 2317 is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER); 2318 2319 /* 2320 * Install a gateway route in the better-router case or an interface 2321 * route in the on-link-destination case. 2322 */ 2323 { 2324 struct sockaddr_in6 sdst; 2325 struct sockaddr_in6 sgw; 2326 struct sockaddr_in6 ssrc; 2327 struct sockaddr *gw; 2328 int rt_flags; 2329 u_int fibnum; 2330 2331 bzero(&sdst, sizeof(sdst)); 2332 bzero(&ssrc, sizeof(ssrc)); 2333 sdst.sin6_family = ssrc.sin6_family = AF_INET6; 2334 sdst.sin6_len = ssrc.sin6_len = sizeof(struct sockaddr_in6); 2335 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr)); 2336 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr)); 2337 rt_flags = 0; 2338 if (is_router) { 2339 bzero(&sgw, sizeof(sgw)); 2340 sgw.sin6_family = AF_INET6; 2341 sgw.sin6_len = sizeof(struct sockaddr_in6); 2342 bcopy(&redtgt6, &sgw.sin6_addr, 2343 sizeof(struct in6_addr)); 2344 gw = (struct sockaddr *)&sgw; 2345 rt_flags |= RTF_GATEWAY; 2346 } else 2347 gw = ifp->if_addr->ifa_addr; 2348 for (fibnum = 0; fibnum < rt_numfibs; fibnum++) 2349 rib_add_redirect(fibnum, (struct sockaddr *)&sdst, gw, 2350 (struct sockaddr *)&ssrc, ifp, rt_flags, 2351 V_icmp6_redirtimeout); 2352 } 2353 2354 freeit: 2355 m_freem(m); 2356 return; 2357 2358 bad: 2359 ICMP6STAT_INC(icp6s_badredirect); 2360 m_freem(m); 2361 } 2362 2363 void 2364 icmp6_redirect_output(struct mbuf *m0, struct nhop_object *nh) 2365 { 2366 struct ifnet *ifp; /* my outgoing interface */ 2367 struct in6_addr *ifp_ll6; 2368 struct in6_addr *router_ll6; 2369 struct ip6_hdr *sip6; /* m0 as struct ip6_hdr */ 2370 struct mbuf *m = NULL; /* newly allocated one */ 2371 struct m_tag *mtag; 2372 struct ip6_hdr *ip6; /* m as struct ip6_hdr */ 2373 struct nd_redirect *nd_rd; 2374 struct llentry *ln = NULL; 2375 size_t maxlen; 2376 u_char *p; 2377 struct ifnet *outif = NULL; 2378 struct sockaddr_in6 src_sa; 2379 2380 icmp6_errcount(ND_REDIRECT, 0); 2381 2382 /* if we are not router, we don't send icmp6 redirect */ 2383 if (!V_ip6_forwarding) 2384 goto fail; 2385 2386 /* sanity check */ 2387 if (!m0 || !nh || !(NH_IS_VALID(nh)) || !(ifp = nh->nh_ifp)) 2388 goto fail; 2389 2390 /* 2391 * Address check: 2392 * the source address must identify a neighbor, and 2393 * the destination address must not be a multicast address 2394 * [RFC 2461, sec 8.2] 2395 */ 2396 sip6 = mtod(m0, struct ip6_hdr *); 2397 bzero(&src_sa, sizeof(src_sa)); 2398 src_sa.sin6_family = AF_INET6; 2399 src_sa.sin6_len = sizeof(src_sa); 2400 src_sa.sin6_addr = sip6->ip6_src; 2401 if (nd6_is_addr_neighbor(&src_sa, ifp) == 0) 2402 goto fail; 2403 if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst)) 2404 goto fail; /* what should we do here? */ 2405 2406 /* rate limit */ 2407 if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0)) 2408 goto fail; 2409 2410 /* 2411 * Since we are going to append up to 1280 bytes (= IPV6_MMTU), 2412 * we almost always ask for an mbuf cluster for simplicity. 2413 * (MHLEN < IPV6_MMTU is almost always true) 2414 */ 2415 #if IPV6_MMTU >= MCLBYTES 2416 # error assumption failed about IPV6_MMTU and MCLBYTES 2417 #endif 2418 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 2419 if (m == NULL) 2420 goto fail; 2421 M_SETFIB(m, M_GETFIB(m0)); 2422 maxlen = M_TRAILINGSPACE(m); 2423 maxlen = min(IPV6_MMTU, maxlen); 2424 /* just for safety */ 2425 if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) + 2426 ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) { 2427 goto fail; 2428 } 2429 2430 { 2431 /* get ip6 linklocal address for ifp(my outgoing interface). */ 2432 struct in6_ifaddr *ia; 2433 if ((ia = in6ifa_ifpforlinklocal(ifp, 2434 IN6_IFF_NOTREADY| 2435 IN6_IFF_ANYCAST)) == NULL) 2436 goto fail; 2437 ifp_ll6 = &ia->ia_addr.sin6_addr; 2438 /* XXXRW: reference released prematurely. */ 2439 ifa_free(&ia->ia_ifa); 2440 } 2441 2442 /* get ip6 linklocal address for the router. */ 2443 if (nh->nh_flags & NHF_GATEWAY) { 2444 struct sockaddr_in6 *sin6; 2445 sin6 = &nh->gw6_sa; 2446 router_ll6 = &sin6->sin6_addr; 2447 if (!IN6_IS_ADDR_LINKLOCAL(router_ll6)) 2448 router_ll6 = (struct in6_addr *)NULL; 2449 } else 2450 router_ll6 = (struct in6_addr *)NULL; 2451 2452 /* ip6 */ 2453 ip6 = mtod(m, struct ip6_hdr *); 2454 ip6->ip6_flow = 0; 2455 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2456 ip6->ip6_vfc |= IPV6_VERSION; 2457 /* ip6->ip6_plen will be set later */ 2458 ip6->ip6_nxt = IPPROTO_ICMPV6; 2459 ip6->ip6_hlim = 255; 2460 /* ip6->ip6_src must be linklocal addr for my outgoing if. */ 2461 bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr)); 2462 bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr)); 2463 2464 /* ND Redirect */ 2465 nd_rd = (struct nd_redirect *)(ip6 + 1); 2466 nd_rd->nd_rd_type = ND_REDIRECT; 2467 nd_rd->nd_rd_code = 0; 2468 nd_rd->nd_rd_reserved = 0; 2469 if (nh->nh_flags & NHF_GATEWAY) { 2470 /* 2471 * nd_rd->nd_rd_target must be a link-local address in 2472 * better router cases. 2473 */ 2474 if (!router_ll6) 2475 goto fail; 2476 bcopy(router_ll6, &nd_rd->nd_rd_target, 2477 sizeof(nd_rd->nd_rd_target)); 2478 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2479 sizeof(nd_rd->nd_rd_dst)); 2480 } else { 2481 /* make sure redtgt == reddst */ 2482 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target, 2483 sizeof(nd_rd->nd_rd_target)); 2484 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2485 sizeof(nd_rd->nd_rd_dst)); 2486 } 2487 2488 p = (u_char *)(nd_rd + 1); 2489 2490 if (!router_ll6) 2491 goto nolladdropt; 2492 2493 { 2494 /* target lladdr option */ 2495 int len; 2496 struct nd_opt_hdr *nd_opt; 2497 char *lladdr; 2498 2499 ln = nd6_lookup(router_ll6, LLE_SF(AF_INET6, 0), ifp); 2500 if (ln == NULL) 2501 goto nolladdropt; 2502 2503 len = sizeof(*nd_opt) + ifp->if_addrlen; 2504 len = (len + 7) & ~7; /* round by 8 */ 2505 /* safety check */ 2506 if (len + (p - (u_char *)ip6) > maxlen) 2507 goto nolladdropt; 2508 2509 if (ln->la_flags & LLE_VALID) { 2510 nd_opt = (struct nd_opt_hdr *)p; 2511 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 2512 nd_opt->nd_opt_len = len >> 3; 2513 lladdr = (char *)(nd_opt + 1); 2514 bcopy(ln->ll_addr, lladdr, ifp->if_addrlen); 2515 p += len; 2516 } 2517 } 2518 nolladdropt: 2519 if (ln != NULL) 2520 LLE_RUNLOCK(ln); 2521 2522 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2523 2524 /* just to be safe */ 2525 #ifdef M_DECRYPTED /*not openbsd*/ 2526 if (m0->m_flags & M_DECRYPTED) 2527 goto noredhdropt; 2528 #endif 2529 if (p - (u_char *)ip6 > maxlen) 2530 goto noredhdropt; 2531 2532 { 2533 /* redirected header option */ 2534 int len; 2535 struct nd_opt_rd_hdr *nd_opt_rh; 2536 2537 /* 2538 * compute the maximum size for icmp6 redirect header option. 2539 * XXX room for auth header? 2540 */ 2541 len = maxlen - (p - (u_char *)ip6); 2542 len &= ~7; 2543 2544 /* This is just for simplicity. */ 2545 if (m0->m_pkthdr.len != m0->m_len) { 2546 if (m0->m_next) { 2547 m_freem(m0->m_next); 2548 m0->m_next = NULL; 2549 } 2550 m0->m_pkthdr.len = m0->m_len; 2551 } 2552 2553 /* 2554 * Redirected header option spec (RFC2461 4.6.3) talks nothing 2555 * about padding/truncate rule for the original IP packet. 2556 * From the discussion on IPv6imp in Feb 1999, 2557 * the consensus was: 2558 * - "attach as much as possible" is the goal 2559 * - pad if not aligned (original size can be guessed by 2560 * original ip6 header) 2561 * Following code adds the padding if it is simple enough, 2562 * and truncates if not. 2563 */ 2564 if (m0->m_next || m0->m_pkthdr.len != m0->m_len) 2565 panic("assumption failed in %s:%d", __FILE__, 2566 __LINE__); 2567 2568 if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) { 2569 /* not enough room, truncate */ 2570 m0->m_pkthdr.len = m0->m_len = len - 2571 sizeof(*nd_opt_rh); 2572 } else { 2573 /* enough room, pad or truncate */ 2574 size_t extra; 2575 2576 extra = m0->m_pkthdr.len % 8; 2577 if (extra) { 2578 /* pad if easy enough, truncate if not */ 2579 if (8 - extra <= M_TRAILINGSPACE(m0)) { 2580 /* pad */ 2581 m0->m_len += (8 - extra); 2582 m0->m_pkthdr.len += (8 - extra); 2583 } else { 2584 /* truncate */ 2585 m0->m_pkthdr.len -= extra; 2586 m0->m_len -= extra; 2587 } 2588 } 2589 len = m0->m_pkthdr.len + sizeof(*nd_opt_rh); 2590 m0->m_pkthdr.len = m0->m_len = len - 2591 sizeof(*nd_opt_rh); 2592 } 2593 2594 nd_opt_rh = (struct nd_opt_rd_hdr *)p; 2595 bzero(nd_opt_rh, sizeof(*nd_opt_rh)); 2596 nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER; 2597 nd_opt_rh->nd_opt_rh_len = len >> 3; 2598 p += sizeof(*nd_opt_rh); 2599 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2600 2601 /* connect m0 to m */ 2602 m_tag_delete_chain(m0, NULL); 2603 m0->m_flags &= ~M_PKTHDR; 2604 m->m_next = m0; 2605 m->m_pkthdr.len = m->m_len + m0->m_len; 2606 m0 = NULL; 2607 } 2608 noredhdropt:; 2609 if (m0) { 2610 m_freem(m0); 2611 m0 = NULL; 2612 } 2613 2614 /* XXX: clear embedded link IDs in the inner header */ 2615 in6_clearscope(&sip6->ip6_src); 2616 in6_clearscope(&sip6->ip6_dst); 2617 in6_clearscope(&nd_rd->nd_rd_target); 2618 in6_clearscope(&nd_rd->nd_rd_dst); 2619 2620 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr)); 2621 2622 nd_rd->nd_rd_cksum = 0; 2623 nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2624 sizeof(*ip6), ntohs(ip6->ip6_plen)); 2625 2626 if (send_sendso_input_hook != NULL) { 2627 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, sizeof(unsigned short), 2628 M_NOWAIT); 2629 if (mtag == NULL) 2630 goto fail; 2631 *(unsigned short *)(mtag + 1) = nd_rd->nd_rd_type; 2632 m_tag_prepend(m, mtag); 2633 } 2634 2635 /* send the packet to outside... */ 2636 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2637 if (outif) { 2638 icmp6_ifstat_inc(outif, ifs6_out_msg); 2639 icmp6_ifstat_inc(outif, ifs6_out_redirect); 2640 } 2641 ICMP6STAT_INC(icp6s_outhist[ND_REDIRECT]); 2642 2643 return; 2644 2645 fail: 2646 if (m) 2647 m_freem(m); 2648 if (m0) 2649 m_freem(m0); 2650 } 2651 2652 /* 2653 * ICMPv6 socket option processing. 2654 */ 2655 int 2656 icmp6_ctloutput(struct socket *so, struct sockopt *sopt) 2657 { 2658 int error = 0; 2659 int optlen; 2660 struct inpcb *inp = sotoinpcb(so); 2661 int level, op, optname; 2662 2663 if (sopt) { 2664 level = sopt->sopt_level; 2665 op = sopt->sopt_dir; 2666 optname = sopt->sopt_name; 2667 optlen = sopt->sopt_valsize; 2668 } else 2669 level = op = optname = optlen = 0; 2670 2671 if (level != IPPROTO_ICMPV6) { 2672 return EINVAL; 2673 } 2674 2675 switch (op) { 2676 case PRCO_SETOPT: 2677 switch (optname) { 2678 case ICMP6_FILTER: 2679 { 2680 struct icmp6_filter ic6f; 2681 2682 if (optlen != sizeof(ic6f)) { 2683 error = EMSGSIZE; 2684 break; 2685 } 2686 error = sooptcopyin(sopt, &ic6f, optlen, optlen); 2687 if (error == 0) { 2688 INP_WLOCK(inp); 2689 *inp->in6p_icmp6filt = ic6f; 2690 INP_WUNLOCK(inp); 2691 } 2692 break; 2693 } 2694 2695 default: 2696 error = ENOPROTOOPT; 2697 break; 2698 } 2699 break; 2700 2701 case PRCO_GETOPT: 2702 switch (optname) { 2703 case ICMP6_FILTER: 2704 { 2705 struct icmp6_filter ic6f; 2706 2707 INP_RLOCK(inp); 2708 ic6f = *inp->in6p_icmp6filt; 2709 INP_RUNLOCK(inp); 2710 error = sooptcopyout(sopt, &ic6f, sizeof(ic6f)); 2711 break; 2712 } 2713 2714 default: 2715 error = ENOPROTOOPT; 2716 break; 2717 } 2718 break; 2719 } 2720 2721 return (error); 2722 } 2723 2724 /* 2725 * Perform rate limit check. 2726 * Returns 0 if it is okay to send the icmp6 packet. 2727 * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate 2728 * limitation. 2729 * 2730 * XXX per-destination/type check necessary? 2731 * 2732 * dst - not used at this moment 2733 * type - not used at this moment 2734 * code - not used at this moment 2735 */ 2736 static int 2737 icmp6_ratelimit(const struct in6_addr *dst, const int type, 2738 const int code) 2739 { 2740 int ret; 2741 2742 ret = 0; /* okay to send */ 2743 2744 /* PPS limit */ 2745 if (!ppsratecheck(&V_icmp6errppslim_last, &V_icmp6errpps_count, 2746 V_icmp6errppslim)) { 2747 /* The packet is subject to rate limit */ 2748 ret++; 2749 } 2750 2751 return ret; 2752 } 2753