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(struct inpcbhead, ripcb); 128 VNET_DECLARE(int, icmp6errppslim); 129 VNET_DEFINE_STATIC(int, icmp6errpps_count) = 0; 130 VNET_DEFINE_STATIC(struct timeval, icmp6errppslim_last); 131 VNET_DECLARE(int, icmp6_nodeinfo); 132 133 #define V_ripcbinfo VNET(ripcbinfo) 134 #define V_ripcb VNET(ripcb) 135 #define V_icmp6errppslim VNET(icmp6errppslim) 136 #define V_icmp6errpps_count VNET(icmp6errpps_count) 137 #define V_icmp6errppslim_last VNET(icmp6errppslim_last) 138 #define V_icmp6_nodeinfo VNET(icmp6_nodeinfo) 139 140 static void icmp6_errcount(int, int); 141 static int icmp6_rip6_input(struct mbuf **, int); 142 static void icmp6_reflect(struct mbuf *, size_t); 143 static int icmp6_ratelimit(const struct in6_addr *, const int, const int); 144 static const char *icmp6_redirect_diag(struct in6_addr *, 145 struct in6_addr *, struct in6_addr *); 146 static struct mbuf *ni6_input(struct mbuf *, int, struct prison *); 147 static struct mbuf *ni6_nametodns(const char *, int, int); 148 static int ni6_dnsmatch(const char *, int, const char *, int); 149 static int ni6_addrs(struct icmp6_nodeinfo *, struct mbuf *, 150 struct ifnet **, struct in6_addr *); 151 static int ni6_store_addrs(struct icmp6_nodeinfo *, struct icmp6_nodeinfo *, 152 struct ifnet *, int); 153 static int icmp6_notify_error(struct mbuf **, int, int, int); 154 155 /* 156 * Kernel module interface for updating icmp6stat. The argument is an index 157 * into icmp6stat treated as an array of u_quad_t. While this encodes the 158 * general layout of icmp6stat into the caller, it doesn't encode its 159 * location, so that future changes to add, for example, per-CPU stats 160 * support won't cause binary compatibility problems for kernel modules. 161 */ 162 void 163 kmod_icmp6stat_inc(int statnum) 164 { 165 166 counter_u64_add(VNET(icmp6stat)[statnum], 1); 167 } 168 169 static void 170 icmp6_errcount(int type, int code) 171 { 172 switch (type) { 173 case ICMP6_DST_UNREACH: 174 switch (code) { 175 case ICMP6_DST_UNREACH_NOROUTE: 176 ICMP6STAT_INC(icp6s_odst_unreach_noroute); 177 return; 178 case ICMP6_DST_UNREACH_ADMIN: 179 ICMP6STAT_INC(icp6s_odst_unreach_admin); 180 return; 181 case ICMP6_DST_UNREACH_BEYONDSCOPE: 182 ICMP6STAT_INC(icp6s_odst_unreach_beyondscope); 183 return; 184 case ICMP6_DST_UNREACH_ADDR: 185 ICMP6STAT_INC(icp6s_odst_unreach_addr); 186 return; 187 case ICMP6_DST_UNREACH_NOPORT: 188 ICMP6STAT_INC(icp6s_odst_unreach_noport); 189 return; 190 } 191 break; 192 case ICMP6_PACKET_TOO_BIG: 193 ICMP6STAT_INC(icp6s_opacket_too_big); 194 return; 195 case ICMP6_TIME_EXCEEDED: 196 switch (code) { 197 case ICMP6_TIME_EXCEED_TRANSIT: 198 ICMP6STAT_INC(icp6s_otime_exceed_transit); 199 return; 200 case ICMP6_TIME_EXCEED_REASSEMBLY: 201 ICMP6STAT_INC(icp6s_otime_exceed_reassembly); 202 return; 203 } 204 break; 205 case ICMP6_PARAM_PROB: 206 switch (code) { 207 case ICMP6_PARAMPROB_HEADER: 208 ICMP6STAT_INC(icp6s_oparamprob_header); 209 return; 210 case ICMP6_PARAMPROB_NEXTHEADER: 211 ICMP6STAT_INC(icp6s_oparamprob_nextheader); 212 return; 213 case ICMP6_PARAMPROB_OPTION: 214 ICMP6STAT_INC(icp6s_oparamprob_option); 215 return; 216 } 217 break; 218 case ND_REDIRECT: 219 ICMP6STAT_INC(icp6s_oredirect); 220 return; 221 } 222 ICMP6STAT_INC(icp6s_ounknown); 223 } 224 225 /* 226 * A wrapper function for icmp6_error() necessary when the erroneous packet 227 * may not contain enough scope zone information. 228 */ 229 void 230 icmp6_error2(struct mbuf *m, int type, int code, int param, 231 struct ifnet *ifp) 232 { 233 struct ip6_hdr *ip6; 234 235 if (ifp == NULL) 236 return; 237 238 if (m->m_len < sizeof(struct ip6_hdr)) { 239 m = m_pullup(m, sizeof(struct ip6_hdr)); 240 if (m == NULL) { 241 IP6STAT_INC(ip6s_exthdrtoolong); 242 return; 243 } 244 } 245 ip6 = mtod(m, struct ip6_hdr *); 246 247 if (in6_setscope(&ip6->ip6_src, ifp, NULL) != 0) 248 return; 249 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0) 250 return; 251 252 icmp6_error(m, type, code, param); 253 } 254 255 /* 256 * Generate an error packet of type error in response to bad IP6 packet. 257 */ 258 void 259 icmp6_error(struct mbuf *m, int type, int code, int param) 260 { 261 struct ip6_hdr *oip6, *nip6; 262 struct icmp6_hdr *icmp6; 263 struct epoch_tracker et; 264 u_int preplen; 265 int off; 266 int nxt; 267 268 ICMP6STAT_INC(icp6s_error); 269 270 /* count per-type-code statistics */ 271 icmp6_errcount(type, code); 272 273 #ifdef M_DECRYPTED /*not openbsd*/ 274 if (m->m_flags & M_DECRYPTED) { 275 ICMP6STAT_INC(icp6s_canterror); 276 goto freeit; 277 } 278 #endif 279 280 if (m->m_len < sizeof(struct ip6_hdr)) { 281 m = m_pullup(m, sizeof(struct ip6_hdr)); 282 if (m == NULL) { 283 IP6STAT_INC(ip6s_exthdrtoolong); 284 return; 285 } 286 } 287 oip6 = mtod(m, struct ip6_hdr *); 288 289 /* 290 * If the destination address of the erroneous packet is a multicast 291 * address, or the packet was sent using link-layer multicast, 292 * we should basically suppress sending an error (RFC 2463, Section 293 * 2.4). 294 * We have two exceptions (the item e.2 in that section): 295 * - the Packet Too Big message can be sent for path MTU discovery. 296 * - the Parameter Problem Message that can be allowed an icmp6 error 297 * in the option type field. This check has been done in 298 * ip6_unknown_opt(), so we can just check the type and code. 299 */ 300 if ((m->m_flags & (M_BCAST|M_MCAST) || 301 IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) && 302 (type != ICMP6_PACKET_TOO_BIG && 303 (type != ICMP6_PARAM_PROB || 304 code != ICMP6_PARAMPROB_OPTION))) 305 goto freeit; 306 307 /* 308 * RFC 2463, 2.4 (e.5): source address check. 309 * XXX: the case of anycast source? 310 */ 311 if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) || 312 IN6_IS_ADDR_MULTICAST(&oip6->ip6_src)) 313 goto freeit; 314 315 /* 316 * If we are about to send ICMPv6 against ICMPv6 error/redirect, 317 * don't do it. 318 */ 319 nxt = -1; 320 off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt); 321 if (off >= 0 && nxt == IPPROTO_ICMPV6) { 322 struct icmp6_hdr *icp; 323 324 if (m->m_len < off + sizeof(struct icmp6_hdr)) { 325 m = m_pullup(m, off + sizeof(struct icmp6_hdr)); 326 if (m == NULL) { 327 IP6STAT_INC(ip6s_exthdrtoolong); 328 return; 329 } 330 } 331 oip6 = mtod(m, struct ip6_hdr *); 332 icp = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 333 334 if (icp->icmp6_type < ICMP6_ECHO_REQUEST || 335 icp->icmp6_type == ND_REDIRECT) { 336 /* 337 * ICMPv6 error 338 * Special case: for redirect (which is 339 * informational) we must not send icmp6 error. 340 */ 341 ICMP6STAT_INC(icp6s_canterror); 342 goto freeit; 343 } else { 344 /* ICMPv6 informational - send the error */ 345 } 346 } else { 347 /* non-ICMPv6 - send the error */ 348 } 349 350 /* Finally, do rate limitation check. */ 351 if (icmp6_ratelimit(&oip6->ip6_src, type, code)) { 352 ICMP6STAT_INC(icp6s_toofreq); 353 goto freeit; 354 } 355 356 /* 357 * OK, ICMP6 can be generated. 358 */ 359 360 if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN) 361 m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len); 362 363 preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 364 M_PREPEND(m, preplen, M_NOWAIT); /* FIB is also copied over. */ 365 if (m == NULL) { 366 nd6log((LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__)); 367 return; 368 } 369 370 nip6 = mtod(m, struct ip6_hdr *); 371 nip6->ip6_src = oip6->ip6_src; 372 nip6->ip6_dst = oip6->ip6_dst; 373 374 in6_clearscope(&oip6->ip6_src); 375 in6_clearscope(&oip6->ip6_dst); 376 377 icmp6 = (struct icmp6_hdr *)(nip6 + 1); 378 icmp6->icmp6_type = type; 379 icmp6->icmp6_code = code; 380 icmp6->icmp6_pptr = htonl((u_int32_t)param); 381 382 ICMP6STAT_INC(icp6s_outhist[type]); 383 NET_EPOCH_ENTER(et); 384 icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */ 385 NET_EPOCH_EXIT(et); 386 387 return; 388 389 freeit: 390 /* 391 * If we can't tell whether or not we can generate ICMP6, free it. 392 */ 393 m_freem(m); 394 } 395 396 /* 397 * Process a received ICMP6 message. 398 */ 399 int 400 icmp6_input(struct mbuf **mp, int *offp, int proto) 401 { 402 struct mbuf *m, *n; 403 struct ifnet *ifp; 404 struct ip6_hdr *ip6, *nip6; 405 struct icmp6_hdr *icmp6, *nicmp6; 406 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 407 int code, error, icmp6len, ip6len, noff, off, sum; 408 409 NET_EPOCH_ASSERT(); 410 411 m = *mp; 412 off = *offp; 413 414 if (m->m_len < off + sizeof(struct icmp6_hdr)) { 415 m = m_pullup(m, off + sizeof(struct icmp6_hdr)); 416 if (m == NULL) { 417 IP6STAT_INC(ip6s_exthdrtoolong); 418 *mp = m; 419 return (IPPROTO_DONE); 420 } 421 } 422 423 /* 424 * Locate icmp6 structure in mbuf, and check 425 * that not corrupted and of at least minimum length 426 */ 427 428 icmp6len = m->m_pkthdr.len - off; 429 if (icmp6len < sizeof(struct icmp6_hdr)) { 430 ICMP6STAT_INC(icp6s_tooshort); 431 goto freeit; 432 } 433 434 ip6 = mtod(m, struct ip6_hdr *); 435 ifp = m->m_pkthdr.rcvif; 436 /* 437 * Check multicast group membership. 438 * Note: SSM filters are not applied for ICMPv6 traffic. 439 */ 440 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 441 struct in6_multi *inm; 442 443 inm = in6m_lookup(ifp, &ip6->ip6_dst); 444 if (inm == NULL) { 445 IP6STAT_INC(ip6s_notmember); 446 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 447 goto freeit; 448 } 449 } 450 451 /* Calculate the checksum. */ 452 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off); 453 code = icmp6->icmp6_code; 454 if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) { 455 nd6log((LOG_ERR, 456 "ICMP6 checksum error(%d|%x) %s\n", 457 icmp6->icmp6_type, sum, 458 ip6_sprintf(ip6bufs, &ip6->ip6_src))); 459 ICMP6STAT_INC(icp6s_checksum); 460 goto freeit; 461 } 462 463 ICMP6STAT_INC(icp6s_inhist[icmp6->icmp6_type]); 464 icmp6_ifstat_inc(ifp, ifs6_in_msg); 465 if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK) 466 icmp6_ifstat_inc(ifp, ifs6_in_error); 467 468 ip6len = sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen); 469 switch (icmp6->icmp6_type) { 470 case ICMP6_DST_UNREACH: 471 icmp6_ifstat_inc(ifp, ifs6_in_dstunreach); 472 switch (code) { 473 case ICMP6_DST_UNREACH_NOROUTE: 474 case ICMP6_DST_UNREACH_ADDR: /* PRC_HOSTDEAD is a DOS */ 475 code = PRC_UNREACH_NET; 476 break; 477 case ICMP6_DST_UNREACH_ADMIN: 478 icmp6_ifstat_inc(ifp, ifs6_in_adminprohib); 479 code = PRC_UNREACH_ADMIN_PROHIB; 480 break; 481 case ICMP6_DST_UNREACH_BEYONDSCOPE: 482 /* I mean "source address was incorrect." */ 483 code = PRC_PARAMPROB; 484 break; 485 case ICMP6_DST_UNREACH_NOPORT: 486 code = PRC_UNREACH_PORT; 487 break; 488 default: 489 goto badcode; 490 } 491 goto deliver; 492 break; 493 494 case ICMP6_PACKET_TOO_BIG: 495 icmp6_ifstat_inc(ifp, ifs6_in_pkttoobig); 496 497 /* validation is made in icmp6_mtudisc_update */ 498 499 code = PRC_MSGSIZE; 500 501 /* 502 * Updating the path MTU will be done after examining 503 * intermediate extension headers. 504 */ 505 goto deliver; 506 break; 507 508 case ICMP6_TIME_EXCEEDED: 509 icmp6_ifstat_inc(ifp, ifs6_in_timeexceed); 510 switch (code) { 511 case ICMP6_TIME_EXCEED_TRANSIT: 512 code = PRC_TIMXCEED_INTRANS; 513 break; 514 case ICMP6_TIME_EXCEED_REASSEMBLY: 515 code = PRC_TIMXCEED_REASS; 516 break; 517 default: 518 goto badcode; 519 } 520 goto deliver; 521 break; 522 523 case ICMP6_PARAM_PROB: 524 icmp6_ifstat_inc(ifp, ifs6_in_paramprob); 525 switch (code) { 526 case ICMP6_PARAMPROB_NEXTHEADER: 527 code = PRC_UNREACH_PROTOCOL; 528 break; 529 case ICMP6_PARAMPROB_HEADER: 530 case ICMP6_PARAMPROB_OPTION: 531 code = PRC_PARAMPROB; 532 break; 533 default: 534 goto badcode; 535 } 536 goto deliver; 537 break; 538 539 case ICMP6_ECHO_REQUEST: 540 icmp6_ifstat_inc(ifp, ifs6_in_echo); 541 if (code != 0) 542 goto badcode; 543 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) { 544 /* Give up remote */ 545 break; 546 } 547 if (!M_WRITABLE(n) 548 || n->m_len < off + sizeof(struct icmp6_hdr)) { 549 struct mbuf *n0 = n; 550 int n0len; 551 552 CTASSERT(sizeof(*nip6) + sizeof(*nicmp6) <= MHLEN); 553 n = m_gethdr(M_NOWAIT, n0->m_type); 554 if (n == NULL) { 555 /* Give up remote */ 556 m_freem(n0); 557 break; 558 } 559 560 m_move_pkthdr(n, n0); /* FIB copied. */ 561 n0len = n0->m_pkthdr.len; /* save for use below */ 562 /* 563 * Copy IPv6 and ICMPv6 only. 564 */ 565 nip6 = mtod(n, struct ip6_hdr *); 566 bcopy(ip6, nip6, sizeof(struct ip6_hdr)); 567 nicmp6 = (struct icmp6_hdr *)(nip6 + 1); 568 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr)); 569 noff = sizeof(struct ip6_hdr); 570 /* new mbuf contains only ipv6+icmpv6 headers */ 571 n->m_len = noff + sizeof(struct icmp6_hdr); 572 /* 573 * Adjust mbuf. ip6_plen will be adjusted in 574 * ip6_output(). 575 */ 576 m_adj(n0, off + sizeof(struct icmp6_hdr)); 577 /* recalculate complete packet size */ 578 n->m_pkthdr.len = n0len + (noff - off); 579 n->m_next = n0; 580 } else { 581 if (n->m_len < off + sizeof(*nicmp6)) { 582 n = m_pullup(n, off + sizeof(*nicmp6)); 583 if (n == NULL) { 584 IP6STAT_INC(ip6s_exthdrtoolong); 585 break; 586 } 587 } 588 nicmp6 = (struct icmp6_hdr *)(mtod(n, caddr_t) + off); 589 noff = off; 590 } 591 if (n) { 592 nicmp6->icmp6_type = ICMP6_ECHO_REPLY; 593 nicmp6->icmp6_code = 0; 594 ICMP6STAT_INC(icp6s_reflect); 595 ICMP6STAT_INC(icp6s_outhist[ICMP6_ECHO_REPLY]); 596 icmp6_reflect(n, noff); 597 } 598 break; 599 600 case ICMP6_ECHO_REPLY: 601 icmp6_ifstat_inc(ifp, ifs6_in_echoreply); 602 if (code != 0) 603 goto badcode; 604 break; 605 606 case MLD_LISTENER_QUERY: 607 case MLD_LISTENER_REPORT: 608 case MLD_LISTENER_DONE: 609 case MLDV2_LISTENER_REPORT: 610 /* 611 * Drop MLD traffic which is not link-local, has a hop limit 612 * of greater than 1 hop, or which does not have the 613 * IPv6 HBH Router Alert option. 614 * As IPv6 HBH options are stripped in ip6_input() we must 615 * check an mbuf header flag. 616 * XXX Should we also sanity check that these messages 617 * were directed to a link-local multicast prefix? 618 */ 619 if ((ip6->ip6_hlim != 1) || (m->m_flags & M_RTALERT_MLD) == 0) 620 goto freeit; 621 if (mld_input(&m, off, icmp6len) != 0) { 622 *mp = NULL; 623 return (IPPROTO_DONE); 624 } 625 /* m stays. */ 626 break; 627 628 case ICMP6_WRUREQUEST: /* ICMP6_FQDN_QUERY */ 629 { 630 enum { WRU, FQDN } mode; 631 struct prison *pr; 632 633 if (!V_icmp6_nodeinfo) 634 break; 635 636 if (icmp6len == sizeof(struct icmp6_hdr) + 4) 637 mode = WRU; 638 else if (icmp6len >= sizeof(struct icmp6_nodeinfo)) 639 mode = FQDN; 640 else 641 goto badlen; 642 643 pr = NULL; 644 sx_slock(&allprison_lock); 645 TAILQ_FOREACH(pr, &allprison, pr_list) 646 if (pr->pr_vnet == ifp->if_vnet) 647 break; 648 sx_sunlock(&allprison_lock); 649 if (pr == NULL) 650 pr = curthread->td_ucred->cr_prison; 651 if (mode == FQDN) { 652 if (m->m_len < off + sizeof(struct icmp6_nodeinfo)) { 653 m = m_pullup(m, off + 654 sizeof(struct icmp6_nodeinfo)); 655 if (m == NULL) { 656 IP6STAT_INC(ip6s_exthdrtoolong); 657 *mp = m; 658 return (IPPROTO_DONE); 659 } 660 } 661 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 662 if (n) 663 n = ni6_input(n, off, pr); 664 /* XXX meaningless if n == NULL */ 665 noff = sizeof(struct ip6_hdr); 666 } else { 667 u_char *p; 668 int maxhlen, hlen; 669 670 /* 671 * XXX: this combination of flags is pointless, 672 * but should we keep this for compatibility? 673 */ 674 if ((V_icmp6_nodeinfo & (ICMP6_NODEINFO_FQDNOK | 675 ICMP6_NODEINFO_TMPADDROK)) != 676 (ICMP6_NODEINFO_FQDNOK | ICMP6_NODEINFO_TMPADDROK)) 677 break; 678 679 if (code != 0) 680 goto badcode; 681 682 CTASSERT(sizeof(*nip6) + sizeof(*nicmp6) + 4 <= MHLEN); 683 n = m_gethdr(M_NOWAIT, m->m_type); 684 if (n == NULL) { 685 /* Give up remote */ 686 break; 687 } 688 if (!m_dup_pkthdr(n, m, M_NOWAIT)) { 689 /* 690 * Previous code did a blind M_COPY_PKTHDR 691 * and said "just for rcvif". If true, then 692 * we could tolerate the dup failing (due to 693 * the deep copy of the tag chain). For now 694 * be conservative and just fail. 695 */ 696 m_free(n); 697 n = NULL; 698 break; 699 } 700 /* 701 * Copy IPv6 and ICMPv6 only. 702 */ 703 nip6 = mtod(n, struct ip6_hdr *); 704 bcopy(ip6, nip6, sizeof(struct ip6_hdr)); 705 nicmp6 = (struct icmp6_hdr *)(nip6 + 1); 706 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr)); 707 p = (u_char *)(nicmp6 + 1); 708 bzero(p, 4); 709 710 maxhlen = M_TRAILINGSPACE(n) - 711 (sizeof(*nip6) + sizeof(*nicmp6) + 4); 712 mtx_lock(&pr->pr_mtx); 713 hlen = strlen(pr->pr_hostname); 714 if (maxhlen > hlen) 715 maxhlen = hlen; 716 /* meaningless TTL */ 717 bcopy(pr->pr_hostname, p + 4, maxhlen); 718 mtx_unlock(&pr->pr_mtx); 719 noff = sizeof(struct ip6_hdr); 720 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + 721 sizeof(struct icmp6_hdr) + 4 + maxhlen; 722 nicmp6->icmp6_type = ICMP6_WRUREPLY; 723 nicmp6->icmp6_code = 0; 724 } 725 if (n) { 726 ICMP6STAT_INC(icp6s_reflect); 727 ICMP6STAT_INC(icp6s_outhist[ICMP6_WRUREPLY]); 728 icmp6_reflect(n, noff); 729 } 730 break; 731 } 732 733 case ICMP6_WRUREPLY: 734 if (code != 0) 735 goto badcode; 736 break; 737 738 case ND_ROUTER_SOLICIT: 739 icmp6_ifstat_inc(ifp, ifs6_in_routersolicit); 740 if (code != 0) 741 goto badcode; 742 if (icmp6len < sizeof(struct nd_router_solicit)) 743 goto badlen; 744 if (send_sendso_input_hook != NULL) { 745 if (m->m_len < off + icmp6len) { 746 m = m_pullup(m, off + icmp6len); 747 if (m == NULL) { 748 IP6STAT_INC(ip6s_exthdrtoolong); 749 *mp = NULL; 750 return (IPPROTO_DONE); 751 } 752 } 753 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 754 if (error == 0) { 755 m = NULL; 756 goto freeit; 757 } 758 } 759 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 760 nd6_rs_input(m, off, icmp6len); 761 m = n; 762 if (m == NULL) 763 goto freeit; 764 break; 765 766 case ND_ROUTER_ADVERT: 767 icmp6_ifstat_inc(ifp, ifs6_in_routeradvert); 768 if (code != 0) 769 goto badcode; 770 if (icmp6len < sizeof(struct nd_router_advert)) 771 goto badlen; 772 if (send_sendso_input_hook != NULL) { 773 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 774 if (error == 0) { 775 m = NULL; 776 goto freeit; 777 } 778 } 779 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 780 nd6_ra_input(m, off, icmp6len); 781 m = n; 782 if (m == NULL) 783 goto freeit; 784 break; 785 786 case ND_NEIGHBOR_SOLICIT: 787 icmp6_ifstat_inc(ifp, ifs6_in_neighborsolicit); 788 if (code != 0) 789 goto badcode; 790 if (icmp6len < sizeof(struct nd_neighbor_solicit)) 791 goto badlen; 792 if (send_sendso_input_hook != NULL) { 793 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 794 if (error == 0) { 795 m = NULL; 796 goto freeit; 797 } 798 } 799 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 800 nd6_ns_input(m, off, icmp6len); 801 m = n; 802 if (m == NULL) 803 goto freeit; 804 break; 805 806 case ND_NEIGHBOR_ADVERT: 807 icmp6_ifstat_inc(ifp, ifs6_in_neighboradvert); 808 if (code != 0) 809 goto badcode; 810 if (icmp6len < sizeof(struct nd_neighbor_advert)) 811 goto badlen; 812 if (send_sendso_input_hook != NULL) { 813 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 814 if (error == 0) { 815 m = NULL; 816 goto freeit; 817 } 818 } 819 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 820 nd6_na_input(m, off, icmp6len); 821 m = n; 822 if (m == NULL) 823 goto freeit; 824 break; 825 826 case ND_REDIRECT: 827 icmp6_ifstat_inc(ifp, ifs6_in_redirect); 828 if (code != 0) 829 goto badcode; 830 if (icmp6len < sizeof(struct nd_redirect)) 831 goto badlen; 832 if (send_sendso_input_hook != NULL) { 833 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 834 if (error == 0) { 835 m = NULL; 836 goto freeit; 837 } 838 } 839 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 840 icmp6_redirect_input(m, off); 841 m = n; 842 if (m == NULL) 843 goto freeit; 844 break; 845 846 case ICMP6_ROUTER_RENUMBERING: 847 if (code != ICMP6_ROUTER_RENUMBERING_COMMAND && 848 code != ICMP6_ROUTER_RENUMBERING_RESULT) 849 goto badcode; 850 if (icmp6len < sizeof(struct icmp6_router_renum)) 851 goto badlen; 852 break; 853 854 default: 855 nd6log((LOG_DEBUG, 856 "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n", 857 icmp6->icmp6_type, ip6_sprintf(ip6bufs, &ip6->ip6_src), 858 ip6_sprintf(ip6bufd, &ip6->ip6_dst), 859 ifp ? ifp->if_index : 0)); 860 if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) { 861 /* ICMPv6 error: MUST deliver it by spec... */ 862 code = PRC_NCMDS; 863 /* deliver */ 864 } else { 865 /* ICMPv6 informational: MUST not deliver */ 866 break; 867 } 868 deliver: 869 if (icmp6_notify_error(&m, off, icmp6len, code) != 0) { 870 /* In this case, m should've been freed. */ 871 *mp = NULL; 872 return (IPPROTO_DONE); 873 } 874 break; 875 876 badcode: 877 ICMP6STAT_INC(icp6s_badcode); 878 break; 879 880 badlen: 881 ICMP6STAT_INC(icp6s_badlen); 882 break; 883 } 884 885 /* deliver the packet to appropriate sockets */ 886 icmp6_rip6_input(&m, *offp); 887 888 *mp = m; 889 return (IPPROTO_DONE); 890 891 freeit: 892 m_freem(m); 893 *mp = NULL; 894 return (IPPROTO_DONE); 895 } 896 897 static int 898 icmp6_notify_error(struct mbuf **mp, int off, int icmp6len, int code) 899 { 900 struct mbuf *m; 901 struct icmp6_hdr *icmp6; 902 struct ip6_hdr *eip6; 903 u_int32_t notifymtu; 904 struct sockaddr_in6 icmp6src, icmp6dst; 905 906 m = *mp; 907 908 if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) { 909 ICMP6STAT_INC(icp6s_tooshort); 910 goto freeit; 911 } 912 913 if (m->m_len < off + sizeof(*icmp6) + sizeof(struct ip6_hdr)) { 914 m = m_pullup(m, off + sizeof(*icmp6) + sizeof(struct ip6_hdr)); 915 if (m == NULL) { 916 IP6STAT_INC(ip6s_exthdrtoolong); 917 *mp = m; 918 return (-1); 919 } 920 } 921 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 922 eip6 = (struct ip6_hdr *)(icmp6 + 1); 923 bzero(&icmp6dst, sizeof(icmp6dst)); 924 925 /* Detect the upper level protocol */ 926 { 927 void (*ctlfunc)(int, struct sockaddr *, void *); 928 u_int8_t nxt = eip6->ip6_nxt; 929 int eoff = off + sizeof(struct icmp6_hdr) + 930 sizeof(struct ip6_hdr); 931 struct ip6ctlparam ip6cp; 932 int icmp6type = icmp6->icmp6_type; 933 struct ip6_frag *fh; 934 struct ip6_rthdr *rth; 935 struct ip6_rthdr0 *rth0; 936 int rthlen; 937 938 while (1) { /* XXX: should avoid infinite loop explicitly? */ 939 struct ip6_ext *eh; 940 941 switch (nxt) { 942 case IPPROTO_HOPOPTS: 943 case IPPROTO_DSTOPTS: 944 case IPPROTO_AH: 945 if (m->m_len < eoff + sizeof(struct ip6_ext)) { 946 m = m_pullup(m, eoff + 947 sizeof(struct ip6_ext)); 948 if (m == NULL) { 949 IP6STAT_INC(ip6s_exthdrtoolong); 950 *mp = m; 951 return (-1); 952 } 953 } 954 eh = (struct ip6_ext *) 955 (mtod(m, caddr_t) + eoff); 956 if (nxt == IPPROTO_AH) 957 eoff += (eh->ip6e_len + 2) << 2; 958 else 959 eoff += (eh->ip6e_len + 1) << 3; 960 nxt = eh->ip6e_nxt; 961 break; 962 case IPPROTO_ROUTING: 963 /* 964 * When the erroneous packet contains a 965 * routing header, we should examine the 966 * header to determine the final destination. 967 * Otherwise, we can't properly update 968 * information that depends on the final 969 * destination (e.g. path MTU). 970 */ 971 if (m->m_len < eoff + sizeof(*rth)) { 972 m = m_pullup(m, eoff + sizeof(*rth)); 973 if (m == NULL) { 974 IP6STAT_INC(ip6s_exthdrtoolong); 975 *mp = m; 976 return (-1); 977 } 978 } 979 rth = (struct ip6_rthdr *) 980 (mtod(m, caddr_t) + eoff); 981 rthlen = (rth->ip6r_len + 1) << 3; 982 /* 983 * XXX: currently there is no 984 * officially defined type other 985 * than type-0. 986 * Note that if the segment left field 987 * is 0, all intermediate hops must 988 * have been passed. 989 */ 990 if (rth->ip6r_segleft && 991 rth->ip6r_type == IPV6_RTHDR_TYPE_0) { 992 int hops; 993 994 if (m->m_len < eoff + rthlen) { 995 m = m_pullup(m, eoff + rthlen); 996 if (m == NULL) { 997 IP6STAT_INC( 998 ip6s_exthdrtoolong); 999 *mp = m; 1000 return (-1); 1001 } 1002 } 1003 rth0 = (struct ip6_rthdr0 *) 1004 (mtod(m, caddr_t) + eoff); 1005 1006 /* just ignore a bogus header */ 1007 if ((rth0->ip6r0_len % 2) == 0 && 1008 (hops = rth0->ip6r0_len/2)) 1009 icmp6dst.sin6_addr = *((struct in6_addr *)(rth0 + 1) + (hops - 1)); 1010 } 1011 eoff += rthlen; 1012 nxt = rth->ip6r_nxt; 1013 break; 1014 case IPPROTO_FRAGMENT: 1015 if (m->m_len < eoff + sizeof(struct ip6_frag)) { 1016 m = m_pullup(m, eoff + 1017 sizeof(struct ip6_frag)); 1018 if (m == NULL) { 1019 IP6STAT_INC(ip6s_exthdrtoolong); 1020 *mp = m; 1021 return (-1); 1022 } 1023 } 1024 fh = (struct ip6_frag *)(mtod(m, caddr_t) + 1025 eoff); 1026 /* 1027 * Data after a fragment header is meaningless 1028 * unless it is the first fragment, but 1029 * we'll go to the notify label for path MTU 1030 * discovery. 1031 */ 1032 if (fh->ip6f_offlg & IP6F_OFF_MASK) 1033 goto notify; 1034 1035 eoff += sizeof(struct ip6_frag); 1036 nxt = fh->ip6f_nxt; 1037 break; 1038 default: 1039 /* 1040 * This case includes ESP and the No Next 1041 * Header. In such cases going to the notify 1042 * label does not have any meaning 1043 * (i.e. ctlfunc will be NULL), but we go 1044 * anyway since we might have to update 1045 * path MTU information. 1046 */ 1047 goto notify; 1048 } 1049 } 1050 notify: 1051 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 1052 1053 /* 1054 * retrieve parameters from the inner IPv6 header, and convert 1055 * them into sockaddr structures. 1056 * XXX: there is no guarantee that the source or destination 1057 * addresses of the inner packet are in the same scope as 1058 * the addresses of the icmp packet. But there is no other 1059 * way to determine the zone. 1060 */ 1061 eip6 = (struct ip6_hdr *)(icmp6 + 1); 1062 1063 icmp6dst.sin6_len = sizeof(struct sockaddr_in6); 1064 icmp6dst.sin6_family = AF_INET6; 1065 if (IN6_IS_ADDR_UNSPECIFIED(&icmp6dst.sin6_addr)) 1066 icmp6dst.sin6_addr = eip6->ip6_dst; 1067 if (in6_setscope(&icmp6dst.sin6_addr, m->m_pkthdr.rcvif, NULL)) 1068 goto freeit; 1069 bzero(&icmp6src, sizeof(icmp6src)); 1070 icmp6src.sin6_len = sizeof(struct sockaddr_in6); 1071 icmp6src.sin6_family = AF_INET6; 1072 icmp6src.sin6_addr = eip6->ip6_src; 1073 if (in6_setscope(&icmp6src.sin6_addr, m->m_pkthdr.rcvif, NULL)) 1074 goto freeit; 1075 icmp6src.sin6_flowinfo = 1076 (eip6->ip6_flow & IPV6_FLOWLABEL_MASK); 1077 1078 ip6cp.ip6c_m = m; 1079 ip6cp.ip6c_icmp6 = icmp6; 1080 ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1); 1081 ip6cp.ip6c_off = eoff; 1082 ip6cp.ip6c_finaldst = &icmp6dst.sin6_addr; 1083 ip6cp.ip6c_src = &icmp6src; 1084 ip6cp.ip6c_nxt = nxt; 1085 1086 if (icmp6type == ICMP6_PACKET_TOO_BIG) { 1087 notifymtu = ntohl(icmp6->icmp6_mtu); 1088 ip6cp.ip6c_cmdarg = (void *)¬ifymtu; 1089 icmp6_mtudisc_update(&ip6cp, 1); /*XXX*/ 1090 } 1091 1092 ctlfunc = (void (*)(int, struct sockaddr *, void *)) 1093 (inet6sw[ip6_protox[nxt]].pr_ctlinput); 1094 if (ctlfunc) { 1095 (void) (*ctlfunc)(code, (struct sockaddr *)&icmp6dst, 1096 &ip6cp); 1097 } 1098 } 1099 *mp = m; 1100 return (0); 1101 1102 freeit: 1103 m_freem(m); 1104 *mp = NULL; 1105 return (-1); 1106 } 1107 1108 void 1109 icmp6_mtudisc_update(struct ip6ctlparam *ip6cp, int validated) 1110 { 1111 struct in6_addr *dst = ip6cp->ip6c_finaldst; 1112 struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6; 1113 struct mbuf *m = ip6cp->ip6c_m; /* will be necessary for scope issue */ 1114 u_int mtu = ntohl(icmp6->icmp6_mtu); 1115 struct in_conninfo inc; 1116 1117 #if 0 1118 /* 1119 * RFC2460 section 5, last paragraph. 1120 * even though minimum link MTU for IPv6 is IPV6_MMTU, 1121 * we may see ICMPv6 too big with mtu < IPV6_MMTU 1122 * due to packet translator in the middle. 1123 * see ip6_output() and ip6_getpmtu() "alwaysfrag" case for 1124 * special handling. 1125 */ 1126 if (mtu < IPV6_MMTU) 1127 return; 1128 #endif 1129 1130 /* 1131 * we reject ICMPv6 too big with abnormally small value. 1132 * XXX what is the good definition of "abnormally small"? 1133 */ 1134 if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8) 1135 return; 1136 1137 if (!validated) 1138 return; 1139 1140 /* 1141 * In case the suggested mtu is less than IPV6_MMTU, we 1142 * only need to remember that it was for above mentioned 1143 * "alwaysfrag" case. 1144 * Try to be as close to the spec as possible. 1145 */ 1146 if (mtu < IPV6_MMTU) 1147 mtu = IPV6_MMTU - 8; 1148 1149 bzero(&inc, sizeof(inc)); 1150 inc.inc_fibnum = M_GETFIB(m); 1151 inc.inc_flags |= INC_ISIPV6; 1152 inc.inc6_faddr = *dst; 1153 if (in6_setscope(&inc.inc6_faddr, m->m_pkthdr.rcvif, NULL)) 1154 return; 1155 1156 if (mtu < tcp_maxmtu6(&inc, NULL)) { 1157 tcp_hc_updatemtu(&inc, mtu); 1158 ICMP6STAT_INC(icp6s_pmtuchg); 1159 } 1160 } 1161 1162 /* 1163 * Process a Node Information Query packet, based on 1164 * draft-ietf-ipngwg-icmp-name-lookups-07. 1165 * 1166 * Spec incompatibilities: 1167 * - IPv6 Subject address handling 1168 * - IPv4 Subject address handling support missing 1169 * - Proxy reply (answer even if it's not for me) 1170 * - joins NI group address at in6_ifattach() time only, does not cope 1171 * with hostname changes by sethostname(3) 1172 */ 1173 static struct mbuf * 1174 ni6_input(struct mbuf *m, int off, struct prison *pr) 1175 { 1176 struct icmp6_nodeinfo *ni6, *nni6; 1177 struct mbuf *n = NULL; 1178 u_int16_t qtype; 1179 int subjlen; 1180 int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); 1181 struct ni_reply_fqdn *fqdn; 1182 int addrs; /* for NI_QTYPE_NODEADDR */ 1183 struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */ 1184 struct in6_addr in6_subj; /* subject address */ 1185 struct ip6_hdr *ip6; 1186 int oldfqdn = 0; /* if 1, return pascal string (03 draft) */ 1187 char *subj = NULL; 1188 struct in6_ifaddr *ia6 = NULL; 1189 1190 ip6 = mtod(m, struct ip6_hdr *); 1191 ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off); 1192 1193 /* 1194 * Validate IPv6 source address. 1195 * The default configuration MUST be to refuse answering queries from 1196 * global-scope addresses according to RFC4602. 1197 * Notes: 1198 * - it's not very clear what "refuse" means; this implementation 1199 * simply drops it. 1200 * - it's not very easy to identify global-scope (unicast) addresses 1201 * since there are many prefixes for them. It should be safer 1202 * and in practice sufficient to check "all" but loopback and 1203 * link-local (note that site-local unicast was deprecated and 1204 * ULA is defined as global scope-wise) 1205 */ 1206 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_GLOBALOK) == 0 && 1207 !IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) && 1208 !IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) 1209 goto bad; 1210 1211 /* 1212 * Validate IPv6 destination address. 1213 * 1214 * The Responder must discard the Query without further processing 1215 * unless it is one of the Responder's unicast or anycast addresses, or 1216 * a link-local scope multicast address which the Responder has joined. 1217 * [RFC4602, Section 5.] 1218 */ 1219 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 1220 if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst)) 1221 goto bad; 1222 /* else it's a link-local multicast, fine */ 1223 } else { /* unicast or anycast */ 1224 ia6 = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */, false); 1225 if (ia6 == NULL) 1226 goto bad; /* XXX impossible */ 1227 1228 if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) && 1229 !(V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK)) { 1230 nd6log((LOG_DEBUG, "ni6_input: ignore node info to " 1231 "a temporary address in %s:%d", 1232 __FILE__, __LINE__)); 1233 goto bad; 1234 } 1235 } 1236 1237 /* validate query Subject field. */ 1238 qtype = ntohs(ni6->ni_qtype); 1239 subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo); 1240 switch (qtype) { 1241 case NI_QTYPE_NOOP: 1242 case NI_QTYPE_SUPTYPES: 1243 /* 07 draft */ 1244 if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0) 1245 break; 1246 /* FALLTHROUGH */ 1247 case NI_QTYPE_FQDN: 1248 case NI_QTYPE_NODEADDR: 1249 case NI_QTYPE_IPV4ADDR: 1250 switch (ni6->ni_code) { 1251 case ICMP6_NI_SUBJ_IPV6: 1252 #if ICMP6_NI_SUBJ_IPV6 != 0 1253 case 0: 1254 #endif 1255 /* 1256 * backward compatibility - try to accept 03 draft 1257 * format, where no Subject is present. 1258 */ 1259 if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 && 1260 subjlen == 0) { 1261 oldfqdn++; 1262 break; 1263 } 1264 #if ICMP6_NI_SUBJ_IPV6 != 0 1265 if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6) 1266 goto bad; 1267 #endif 1268 1269 if (subjlen != sizeof(struct in6_addr)) 1270 goto bad; 1271 1272 /* 1273 * Validate Subject address. 1274 * 1275 * Not sure what exactly "address belongs to the node" 1276 * means in the spec, is it just unicast, or what? 1277 * 1278 * At this moment we consider Subject address as 1279 * "belong to the node" if the Subject address equals 1280 * to the IPv6 destination address; validation for 1281 * IPv6 destination address should have done enough 1282 * check for us. 1283 * 1284 * We do not do proxy at this moment. 1285 */ 1286 m_copydata(m, off + sizeof(struct icmp6_nodeinfo), 1287 subjlen, (caddr_t)&in6_subj); 1288 if (in6_setscope(&in6_subj, m->m_pkthdr.rcvif, NULL)) 1289 goto bad; 1290 1291 subj = (char *)&in6_subj; 1292 if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &in6_subj)) 1293 break; 1294 1295 /* 1296 * XXX if we are to allow other cases, we should really 1297 * be careful about scope here. 1298 * basically, we should disallow queries toward IPv6 1299 * destination X with subject Y, 1300 * if scope(X) > scope(Y). 1301 * if we allow scope(X) > scope(Y), it will result in 1302 * information leakage across scope boundary. 1303 */ 1304 goto bad; 1305 1306 case ICMP6_NI_SUBJ_FQDN: 1307 /* 1308 * Validate Subject name with gethostname(3). 1309 * 1310 * The behavior may need some debate, since: 1311 * - we are not sure if the node has FQDN as 1312 * hostname (returned by gethostname(3)). 1313 * - the code does wildcard match for truncated names. 1314 * however, we are not sure if we want to perform 1315 * wildcard match, if gethostname(3) side has 1316 * truncated hostname. 1317 */ 1318 mtx_lock(&pr->pr_mtx); 1319 n = ni6_nametodns(pr->pr_hostname, 1320 strlen(pr->pr_hostname), 0); 1321 mtx_unlock(&pr->pr_mtx); 1322 if (!n || n->m_next || n->m_len == 0) 1323 goto bad; 1324 if (m->m_len < off + sizeof(struct icmp6_nodeinfo) + 1325 subjlen) { 1326 m = m_pullup(m, off + 1327 sizeof(struct icmp6_nodeinfo) + subjlen); 1328 if (m == NULL) { 1329 IP6STAT_INC(ip6s_exthdrtoolong); 1330 goto bad; 1331 } 1332 } 1333 /* ip6 possibly invalid but not used after. */ 1334 ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off); 1335 subj = (char *)(mtod(m, caddr_t) + off + 1336 sizeof(struct icmp6_nodeinfo)); 1337 if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *), 1338 n->m_len)) { 1339 goto bad; 1340 } 1341 m_freem(n); 1342 n = NULL; 1343 break; 1344 1345 case ICMP6_NI_SUBJ_IPV4: /* XXX: to be implemented? */ 1346 default: 1347 goto bad; 1348 } 1349 break; 1350 } 1351 1352 /* refuse based on configuration. XXX ICMP6_NI_REFUSED? */ 1353 switch (qtype) { 1354 case NI_QTYPE_FQDN: 1355 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_FQDNOK) == 0) 1356 goto bad; 1357 break; 1358 case NI_QTYPE_NODEADDR: 1359 case NI_QTYPE_IPV4ADDR: 1360 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_NODEADDROK) == 0) 1361 goto bad; 1362 break; 1363 } 1364 1365 /* guess reply length */ 1366 switch (qtype) { 1367 case NI_QTYPE_NOOP: 1368 break; /* no reply data */ 1369 case NI_QTYPE_SUPTYPES: 1370 replylen += sizeof(u_int32_t); 1371 break; 1372 case NI_QTYPE_FQDN: 1373 /* XXX will append an mbuf */ 1374 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); 1375 break; 1376 case NI_QTYPE_NODEADDR: 1377 addrs = ni6_addrs(ni6, m, &ifp, (struct in6_addr *)subj); 1378 if ((replylen += addrs * (sizeof(struct in6_addr) + 1379 sizeof(u_int32_t))) > MCLBYTES) 1380 replylen = MCLBYTES; /* XXX: will truncate pkt later */ 1381 break; 1382 case NI_QTYPE_IPV4ADDR: 1383 /* unsupported - should respond with unknown Qtype? */ 1384 break; 1385 default: 1386 /* 1387 * XXX: We must return a reply with the ICMP6 code 1388 * `unknown Qtype' in this case. However we regard the case 1389 * as an FQDN query for backward compatibility. 1390 * Older versions set a random value to this field, 1391 * so it rarely varies in the defined qtypes. 1392 * But the mechanism is not reliable... 1393 * maybe we should obsolete older versions. 1394 */ 1395 qtype = NI_QTYPE_FQDN; 1396 /* XXX will append an mbuf */ 1397 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); 1398 oldfqdn++; 1399 break; 1400 } 1401 1402 /* Allocate an mbuf to reply. */ 1403 if (replylen > MCLBYTES) { 1404 /* 1405 * XXX: should we try to allocate more? But MCLBYTES 1406 * is probably much larger than IPV6_MMTU... 1407 */ 1408 goto bad; 1409 } 1410 if (replylen > MHLEN) 1411 n = m_getcl(M_NOWAIT, m->m_type, M_PKTHDR); 1412 else 1413 n = m_gethdr(M_NOWAIT, m->m_type); 1414 if (n == NULL) { 1415 m_freem(m); 1416 return (NULL); 1417 } 1418 m_move_pkthdr(n, m); /* just for recvif and FIB */ 1419 n->m_pkthdr.len = n->m_len = replylen; 1420 1421 /* copy mbuf header and IPv6 + Node Information base headers */ 1422 bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr)); 1423 nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1); 1424 bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo)); 1425 1426 /* qtype dependent procedure */ 1427 switch (qtype) { 1428 case NI_QTYPE_NOOP: 1429 nni6->ni_code = ICMP6_NI_SUCCESS; 1430 nni6->ni_flags = 0; 1431 break; 1432 case NI_QTYPE_SUPTYPES: 1433 { 1434 u_int32_t v; 1435 nni6->ni_code = ICMP6_NI_SUCCESS; 1436 nni6->ni_flags = htons(0x0000); /* raw bitmap */ 1437 /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */ 1438 v = (u_int32_t)htonl(0x0000000f); 1439 bcopy(&v, nni6 + 1, sizeof(u_int32_t)); 1440 break; 1441 } 1442 case NI_QTYPE_FQDN: 1443 nni6->ni_code = ICMP6_NI_SUCCESS; 1444 fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) + 1445 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo)); 1446 nni6->ni_flags = 0; /* XXX: meaningless TTL */ 1447 fqdn->ni_fqdn_ttl = 0; /* ditto. */ 1448 /* 1449 * XXX do we really have FQDN in hostname? 1450 */ 1451 mtx_lock(&pr->pr_mtx); 1452 n->m_next = ni6_nametodns(pr->pr_hostname, 1453 strlen(pr->pr_hostname), oldfqdn); 1454 mtx_unlock(&pr->pr_mtx); 1455 if (n->m_next == NULL) 1456 goto bad; 1457 /* XXX we assume that n->m_next is not a chain */ 1458 if (n->m_next->m_next != NULL) 1459 goto bad; 1460 n->m_pkthdr.len += n->m_next->m_len; 1461 break; 1462 case NI_QTYPE_NODEADDR: 1463 { 1464 int lenlim, copied; 1465 1466 nni6->ni_code = ICMP6_NI_SUCCESS; 1467 n->m_pkthdr.len = n->m_len = 1468 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); 1469 lenlim = M_TRAILINGSPACE(n); 1470 copied = ni6_store_addrs(ni6, nni6, ifp, lenlim); 1471 /* XXX: reset mbuf length */ 1472 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + 1473 sizeof(struct icmp6_nodeinfo) + copied; 1474 break; 1475 } 1476 default: 1477 break; /* XXX impossible! */ 1478 } 1479 1480 nni6->ni_type = ICMP6_NI_REPLY; 1481 m_freem(m); 1482 return (n); 1483 1484 bad: 1485 m_freem(m); 1486 if (n) 1487 m_freem(n); 1488 return (NULL); 1489 } 1490 1491 /* 1492 * make a mbuf with DNS-encoded string. no compression support. 1493 * 1494 * XXX names with less than 2 dots (like "foo" or "foo.section") will be 1495 * treated as truncated name (two \0 at the end). this is a wild guess. 1496 * 1497 * old - return pascal string if non-zero 1498 */ 1499 static struct mbuf * 1500 ni6_nametodns(const char *name, int namelen, int old) 1501 { 1502 struct mbuf *m; 1503 char *cp, *ep; 1504 const char *p, *q; 1505 int i, len, nterm; 1506 1507 if (old) 1508 len = namelen + 1; 1509 else 1510 len = MCLBYTES; 1511 1512 /* Because MAXHOSTNAMELEN is usually 256, we use cluster mbuf. */ 1513 if (len > MLEN) 1514 m = m_getcl(M_NOWAIT, MT_DATA, 0); 1515 else 1516 m = m_get(M_NOWAIT, MT_DATA); 1517 if (m == NULL) 1518 goto fail; 1519 1520 if (old) { 1521 m->m_len = len; 1522 *mtod(m, char *) = namelen; 1523 bcopy(name, mtod(m, char *) + 1, namelen); 1524 return m; 1525 } else { 1526 m->m_len = 0; 1527 cp = mtod(m, char *); 1528 ep = mtod(m, char *) + M_TRAILINGSPACE(m); 1529 1530 /* if not certain about my name, return empty buffer */ 1531 if (namelen == 0) 1532 return m; 1533 1534 /* 1535 * guess if it looks like shortened hostname, or FQDN. 1536 * shortened hostname needs two trailing "\0". 1537 */ 1538 i = 0; 1539 for (p = name; p < name + namelen; p++) { 1540 if (*p && *p == '.') 1541 i++; 1542 } 1543 if (i < 2) 1544 nterm = 2; 1545 else 1546 nterm = 1; 1547 1548 p = name; 1549 while (cp < ep && p < name + namelen) { 1550 i = 0; 1551 for (q = p; q < name + namelen && *q && *q != '.'; q++) 1552 i++; 1553 /* result does not fit into mbuf */ 1554 if (cp + i + 1 >= ep) 1555 goto fail; 1556 /* 1557 * DNS label length restriction, RFC1035 page 8. 1558 * "i == 0" case is included here to avoid returning 1559 * 0-length label on "foo..bar". 1560 */ 1561 if (i <= 0 || i >= 64) 1562 goto fail; 1563 *cp++ = i; 1564 bcopy(p, cp, i); 1565 cp += i; 1566 p = q; 1567 if (p < name + namelen && *p == '.') 1568 p++; 1569 } 1570 /* termination */ 1571 if (cp + nterm >= ep) 1572 goto fail; 1573 while (nterm-- > 0) 1574 *cp++ = '\0'; 1575 m->m_len = cp - mtod(m, char *); 1576 return m; 1577 } 1578 1579 panic("should not reach here"); 1580 /* NOTREACHED */ 1581 1582 fail: 1583 if (m) 1584 m_freem(m); 1585 return NULL; 1586 } 1587 1588 /* 1589 * check if two DNS-encoded string matches. takes care of truncated 1590 * form (with \0\0 at the end). no compression support. 1591 * XXX upper/lowercase match (see RFC2065) 1592 */ 1593 static int 1594 ni6_dnsmatch(const char *a, int alen, const char *b, int blen) 1595 { 1596 const char *a0, *b0; 1597 int l; 1598 1599 /* simplest case - need validation? */ 1600 if (alen == blen && bcmp(a, b, alen) == 0) 1601 return 1; 1602 1603 a0 = a; 1604 b0 = b; 1605 1606 /* termination is mandatory */ 1607 if (alen < 2 || blen < 2) 1608 return 0; 1609 if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0') 1610 return 0; 1611 alen--; 1612 blen--; 1613 1614 while (a - a0 < alen && b - b0 < blen) { 1615 if (a - a0 + 1 > alen || b - b0 + 1 > blen) 1616 return 0; 1617 1618 if ((signed char)a[0] < 0 || (signed char)b[0] < 0) 1619 return 0; 1620 /* we don't support compression yet */ 1621 if (a[0] >= 64 || b[0] >= 64) 1622 return 0; 1623 1624 /* truncated case */ 1625 if (a[0] == 0 && a - a0 == alen - 1) 1626 return 1; 1627 if (b[0] == 0 && b - b0 == blen - 1) 1628 return 1; 1629 if (a[0] == 0 || b[0] == 0) 1630 return 0; 1631 1632 if (a[0] != b[0]) 1633 return 0; 1634 l = a[0]; 1635 if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen) 1636 return 0; 1637 if (bcmp(a + 1, b + 1, l) != 0) 1638 return 0; 1639 1640 a += 1 + l; 1641 b += 1 + l; 1642 } 1643 1644 if (a - a0 == alen && b - b0 == blen) 1645 return 1; 1646 else 1647 return 0; 1648 } 1649 1650 /* 1651 * calculate the number of addresses to be returned in the node info reply. 1652 */ 1653 static int 1654 ni6_addrs(struct icmp6_nodeinfo *ni6, struct mbuf *m, struct ifnet **ifpp, 1655 struct in6_addr *subj) 1656 { 1657 struct ifnet *ifp; 1658 struct in6_ifaddr *ifa6; 1659 struct ifaddr *ifa; 1660 int addrs = 0, addrsofif, iffound = 0; 1661 int niflags = ni6->ni_flags; 1662 1663 NET_EPOCH_ASSERT(); 1664 1665 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) { 1666 switch (ni6->ni_code) { 1667 case ICMP6_NI_SUBJ_IPV6: 1668 if (subj == NULL) /* must be impossible... */ 1669 return (0); 1670 break; 1671 default: 1672 /* 1673 * XXX: we only support IPv6 subject address for 1674 * this Qtype. 1675 */ 1676 return (0); 1677 } 1678 } 1679 1680 CK_STAILQ_FOREACH(ifp, &V_ifnet, if_link) { 1681 addrsofif = 0; 1682 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 1683 if (ifa->ifa_addr->sa_family != AF_INET6) 1684 continue; 1685 ifa6 = (struct in6_ifaddr *)ifa; 1686 1687 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 && 1688 IN6_ARE_ADDR_EQUAL(subj, &ifa6->ia_addr.sin6_addr)) 1689 iffound = 1; 1690 1691 /* 1692 * IPv4-mapped addresses can only be returned by a 1693 * Node Information proxy, since they represent 1694 * addresses of IPv4-only nodes, which perforce do 1695 * not implement this protocol. 1696 * [icmp-name-lookups-07, Section 5.4] 1697 * So we don't support NI_NODEADDR_FLAG_COMPAT in 1698 * this function at this moment. 1699 */ 1700 1701 /* What do we have to do about ::1? */ 1702 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { 1703 case IPV6_ADDR_SCOPE_LINKLOCAL: 1704 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) 1705 continue; 1706 break; 1707 case IPV6_ADDR_SCOPE_SITELOCAL: 1708 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) 1709 continue; 1710 break; 1711 case IPV6_ADDR_SCOPE_GLOBAL: 1712 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) 1713 continue; 1714 break; 1715 default: 1716 continue; 1717 } 1718 1719 /* 1720 * check if anycast is okay. 1721 * XXX: just experimental. not in the spec. 1722 */ 1723 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && 1724 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) 1725 continue; /* we need only unicast addresses */ 1726 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && 1727 (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) { 1728 continue; 1729 } 1730 addrsofif++; /* count the address */ 1731 } 1732 if (iffound) { 1733 *ifpp = ifp; 1734 return (addrsofif); 1735 } 1736 1737 addrs += addrsofif; 1738 } 1739 1740 return (addrs); 1741 } 1742 1743 static int 1744 ni6_store_addrs(struct icmp6_nodeinfo *ni6, struct icmp6_nodeinfo *nni6, 1745 struct ifnet *ifp0, int resid) 1746 { 1747 struct ifnet *ifp; 1748 struct in6_ifaddr *ifa6; 1749 struct ifaddr *ifa; 1750 struct ifnet *ifp_dep = NULL; 1751 int copied = 0, allow_deprecated = 0; 1752 u_char *cp = (u_char *)(nni6 + 1); 1753 int niflags = ni6->ni_flags; 1754 u_int32_t ltime; 1755 1756 NET_EPOCH_ASSERT(); 1757 1758 if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL)) 1759 return (0); /* needless to copy */ 1760 1761 ifp = ifp0 ? ifp0 : CK_STAILQ_FIRST(&V_ifnet); 1762 again: 1763 1764 for (; ifp; ifp = CK_STAILQ_NEXT(ifp, if_link)) { 1765 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 1766 if (ifa->ifa_addr->sa_family != AF_INET6) 1767 continue; 1768 ifa6 = (struct in6_ifaddr *)ifa; 1769 1770 if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 && 1771 allow_deprecated == 0) { 1772 /* 1773 * prefererred address should be put before 1774 * deprecated addresses. 1775 */ 1776 1777 /* record the interface for later search */ 1778 if (ifp_dep == NULL) 1779 ifp_dep = ifp; 1780 1781 continue; 1782 } else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 && 1783 allow_deprecated != 0) 1784 continue; /* we now collect deprecated addrs */ 1785 1786 /* What do we have to do about ::1? */ 1787 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { 1788 case IPV6_ADDR_SCOPE_LINKLOCAL: 1789 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) 1790 continue; 1791 break; 1792 case IPV6_ADDR_SCOPE_SITELOCAL: 1793 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) 1794 continue; 1795 break; 1796 case IPV6_ADDR_SCOPE_GLOBAL: 1797 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) 1798 continue; 1799 break; 1800 default: 1801 continue; 1802 } 1803 1804 /* 1805 * check if anycast is okay. 1806 * XXX: just experimental. not in the spec. 1807 */ 1808 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && 1809 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) 1810 continue; 1811 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && 1812 (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) { 1813 continue; 1814 } 1815 1816 /* now we can copy the address */ 1817 if (resid < sizeof(struct in6_addr) + 1818 sizeof(u_int32_t)) { 1819 /* 1820 * We give up much more copy. 1821 * Set the truncate flag and return. 1822 */ 1823 nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE; 1824 return (copied); 1825 } 1826 1827 /* 1828 * Set the TTL of the address. 1829 * The TTL value should be one of the following 1830 * according to the specification: 1831 * 1832 * 1. The remaining lifetime of a DHCP lease on the 1833 * address, or 1834 * 2. The remaining Valid Lifetime of a prefix from 1835 * which the address was derived through Stateless 1836 * Autoconfiguration. 1837 * 1838 * Note that we currently do not support stateful 1839 * address configuration by DHCPv6, so the former 1840 * case can't happen. 1841 */ 1842 if (ifa6->ia6_lifetime.ia6t_expire == 0) 1843 ltime = ND6_INFINITE_LIFETIME; 1844 else { 1845 if (ifa6->ia6_lifetime.ia6t_expire > 1846 time_uptime) 1847 ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_uptime); 1848 else 1849 ltime = 0; 1850 } 1851 1852 bcopy(<ime, cp, sizeof(u_int32_t)); 1853 cp += sizeof(u_int32_t); 1854 1855 /* copy the address itself */ 1856 bcopy(&ifa6->ia_addr.sin6_addr, cp, 1857 sizeof(struct in6_addr)); 1858 in6_clearscope((struct in6_addr *)cp); /* XXX */ 1859 cp += sizeof(struct in6_addr); 1860 1861 resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t)); 1862 copied += (sizeof(struct in6_addr) + sizeof(u_int32_t)); 1863 } 1864 if (ifp0) /* we need search only on the specified IF */ 1865 break; 1866 } 1867 1868 if (allow_deprecated == 0 && ifp_dep != NULL) { 1869 ifp = ifp_dep; 1870 allow_deprecated = 1; 1871 1872 goto again; 1873 } 1874 1875 return (copied); 1876 } 1877 1878 /* 1879 * XXX almost dup'ed code with rip6_input. 1880 */ 1881 static int 1882 icmp6_rip6_input(struct mbuf **mp, int off) 1883 { 1884 struct mbuf *m = *mp; 1885 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1886 struct inpcb *inp; 1887 struct inpcb *last = NULL; 1888 struct sockaddr_in6 fromsa; 1889 struct icmp6_hdr *icmp6; 1890 struct mbuf *opts = NULL; 1891 1892 NET_EPOCH_ASSERT(); 1893 1894 /* This is assumed to be safe; icmp6_input() does a pullup. */ 1895 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off); 1896 1897 /* 1898 * XXX: the address may have embedded scope zone ID, which should be 1899 * hidden from applications. 1900 */ 1901 bzero(&fromsa, sizeof(fromsa)); 1902 fromsa.sin6_family = AF_INET6; 1903 fromsa.sin6_len = sizeof(struct sockaddr_in6); 1904 fromsa.sin6_addr = ip6->ip6_src; 1905 if (sa6_recoverscope(&fromsa)) { 1906 m_freem(m); 1907 *mp = NULL; 1908 return (IPPROTO_DONE); 1909 } 1910 1911 CK_LIST_FOREACH(inp, &V_ripcb, inp_list) { 1912 if ((inp->inp_vflag & INP_IPV6) == 0) 1913 continue; 1914 if (inp->inp_ip_p != IPPROTO_ICMPV6) 1915 continue; 1916 if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr) && 1917 !IN6_ARE_ADDR_EQUAL(&inp->in6p_laddr, &ip6->ip6_dst)) 1918 continue; 1919 if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr) && 1920 !IN6_ARE_ADDR_EQUAL(&inp->in6p_faddr, &ip6->ip6_src)) 1921 continue; 1922 INP_RLOCK(inp); 1923 if (__predict_false(inp->inp_flags2 & INP_FREED)) { 1924 INP_RUNLOCK(inp); 1925 continue; 1926 } 1927 if (ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type, 1928 inp->in6p_icmp6filt)) { 1929 INP_RUNLOCK(inp); 1930 continue; 1931 } 1932 if (last != NULL) { 1933 struct mbuf *n = NULL; 1934 1935 /* 1936 * Recent network drivers tend to allocate a single 1937 * mbuf cluster, rather than to make a couple of 1938 * mbufs without clusters. Also, since the IPv6 code 1939 * path tries to avoid m_pullup(), it is highly 1940 * probable that we still have an mbuf cluster here 1941 * even though the necessary length can be stored in an 1942 * mbuf's internal buffer. 1943 * Meanwhile, the default size of the receive socket 1944 * buffer for raw sockets is not so large. This means 1945 * the possibility of packet loss is relatively higher 1946 * than before. To avoid this scenario, we copy the 1947 * received data to a separate mbuf that does not use 1948 * a cluster, if possible. 1949 * XXX: it is better to copy the data after stripping 1950 * intermediate headers. 1951 */ 1952 if ((m->m_flags & M_EXT) && m->m_next == NULL && 1953 m->m_len <= MHLEN) { 1954 n = m_get(M_NOWAIT, m->m_type); 1955 if (n != NULL) { 1956 if (m_dup_pkthdr(n, m, M_NOWAIT)) { 1957 bcopy(m->m_data, n->m_data, 1958 m->m_len); 1959 n->m_len = m->m_len; 1960 } else { 1961 m_free(n); 1962 n = NULL; 1963 } 1964 } 1965 } 1966 if (n != NULL || 1967 (n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) != NULL) { 1968 if (last->inp_flags & INP_CONTROLOPTS) 1969 ip6_savecontrol(last, n, &opts); 1970 /* strip intermediate headers */ 1971 m_adj(n, off); 1972 SOCKBUF_LOCK(&last->inp_socket->so_rcv); 1973 if (sbappendaddr_locked( 1974 &last->inp_socket->so_rcv, 1975 (struct sockaddr *)&fromsa, n, opts) 1976 == 0) { 1977 soroverflow_locked(last->inp_socket); 1978 m_freem(n); 1979 if (opts) { 1980 m_freem(opts); 1981 } 1982 } else 1983 sorwakeup_locked(last->inp_socket); 1984 opts = NULL; 1985 } 1986 INP_RUNLOCK(last); 1987 } 1988 last = inp; 1989 } 1990 if (last != NULL) { 1991 if (last->inp_flags & INP_CONTROLOPTS) 1992 ip6_savecontrol(last, m, &opts); 1993 /* strip intermediate headers */ 1994 m_adj(m, off); 1995 1996 /* avoid using mbuf clusters if possible (see above) */ 1997 if ((m->m_flags & M_EXT) && m->m_next == NULL && 1998 m->m_len <= MHLEN) { 1999 struct mbuf *n; 2000 2001 n = m_get(M_NOWAIT, m->m_type); 2002 if (n != NULL) { 2003 if (m_dup_pkthdr(n, m, M_NOWAIT)) { 2004 bcopy(m->m_data, n->m_data, m->m_len); 2005 n->m_len = m->m_len; 2006 2007 m_freem(m); 2008 m = n; 2009 } else { 2010 m_freem(n); 2011 n = NULL; 2012 } 2013 } 2014 } 2015 SOCKBUF_LOCK(&last->inp_socket->so_rcv); 2016 if (sbappendaddr_locked(&last->inp_socket->so_rcv, 2017 (struct sockaddr *)&fromsa, m, opts) == 0) { 2018 m_freem(m); 2019 if (opts) 2020 m_freem(opts); 2021 soroverflow_locked(last->inp_socket); 2022 } else 2023 sorwakeup_locked(last->inp_socket); 2024 INP_RUNLOCK(last); 2025 } else { 2026 m_freem(m); 2027 IP6STAT_DEC(ip6s_delivered); 2028 } 2029 *mp = NULL; 2030 return (IPPROTO_DONE); 2031 } 2032 2033 /* 2034 * Reflect the ip6 packet back to the source. 2035 * OFF points to the icmp6 header, counted from the top of the mbuf. 2036 */ 2037 static void 2038 icmp6_reflect(struct mbuf *m, size_t off) 2039 { 2040 struct in6_addr src6, *srcp; 2041 struct ip6_hdr *ip6; 2042 struct icmp6_hdr *icmp6; 2043 struct in6_ifaddr *ia = NULL; 2044 struct ifnet *outif = NULL; 2045 int plen; 2046 int type, code, hlim; 2047 2048 /* too short to reflect */ 2049 if (off < sizeof(struct ip6_hdr)) { 2050 nd6log((LOG_DEBUG, 2051 "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n", 2052 (u_long)off, (u_long)sizeof(struct ip6_hdr), 2053 __FILE__, __LINE__)); 2054 goto bad; 2055 } 2056 2057 /* 2058 * If there are extra headers between IPv6 and ICMPv6, strip 2059 * off that header first. 2060 */ 2061 #ifdef DIAGNOSTIC 2062 if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN) 2063 panic("assumption failed in icmp6_reflect"); 2064 #endif 2065 if (off > sizeof(struct ip6_hdr)) { 2066 size_t l; 2067 struct ip6_hdr nip6; 2068 2069 l = off - sizeof(struct ip6_hdr); 2070 m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6); 2071 m_adj(m, l); 2072 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 2073 if (m->m_len < l) { 2074 if ((m = m_pullup(m, l)) == NULL) 2075 return; 2076 } 2077 bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6)); 2078 } else /* off == sizeof(struct ip6_hdr) */ { 2079 size_t l; 2080 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 2081 if (m->m_len < l) { 2082 if ((m = m_pullup(m, l)) == NULL) 2083 return; 2084 } 2085 } 2086 plen = m->m_pkthdr.len - sizeof(struct ip6_hdr); 2087 ip6 = mtod(m, struct ip6_hdr *); 2088 ip6->ip6_nxt = IPPROTO_ICMPV6; 2089 icmp6 = (struct icmp6_hdr *)(ip6 + 1); 2090 type = icmp6->icmp6_type; /* keep type for statistics */ 2091 code = icmp6->icmp6_code; /* ditto. */ 2092 hlim = 0; 2093 srcp = NULL; 2094 2095 /* 2096 * If the incoming packet was addressed directly to us (i.e. unicast), 2097 * use dst as the src for the reply. 2098 * The IN6_IFF_NOTREADY case should be VERY rare, but is possible 2099 * (for example) when we encounter an error while forwarding procedure 2100 * destined to a duplicated address of ours. 2101 */ 2102 if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 2103 ia = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */, false); 2104 if (ia != NULL && !(ia->ia6_flags & 2105 (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) { 2106 src6 = ia->ia_addr.sin6_addr; 2107 srcp = &src6; 2108 2109 if (m->m_pkthdr.rcvif != NULL) { 2110 /* XXX: This may not be the outgoing interface */ 2111 hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim; 2112 } else 2113 hlim = V_ip6_defhlim; 2114 } 2115 } 2116 2117 if (srcp == NULL) { 2118 int error; 2119 struct in6_addr dst6; 2120 uint32_t scopeid; 2121 2122 /* 2123 * This case matches to multicasts, our anycast, or unicasts 2124 * that we do not own. Select a source address based on the 2125 * source address of the erroneous packet. 2126 */ 2127 in6_splitscope(&ip6->ip6_src, &dst6, &scopeid); 2128 error = in6_selectsrc_addr(M_GETFIB(m), &dst6, 2129 scopeid, NULL, &src6, &hlim); 2130 2131 if (error) { 2132 char ip6buf[INET6_ADDRSTRLEN]; 2133 nd6log((LOG_DEBUG, 2134 "icmp6_reflect: source can't be determined: " 2135 "dst=%s, error=%d\n", 2136 ip6_sprintf(ip6buf, &ip6->ip6_dst), error)); 2137 goto bad; 2138 } 2139 srcp = &src6; 2140 } 2141 /* 2142 * ip6_input() drops a packet if its src is multicast. 2143 * So, the src is never multicast. 2144 */ 2145 ip6->ip6_dst = ip6->ip6_src; 2146 ip6->ip6_src = *srcp; 2147 ip6->ip6_flow = 0; 2148 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2149 ip6->ip6_vfc |= IPV6_VERSION; 2150 ip6->ip6_nxt = IPPROTO_ICMPV6; 2151 ip6->ip6_hlim = hlim; 2152 2153 icmp6->icmp6_cksum = 0; 2154 icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2155 sizeof(struct ip6_hdr), plen); 2156 2157 /* 2158 * XXX option handling 2159 */ 2160 2161 m->m_flags &= ~(M_BCAST|M_MCAST); 2162 m->m_pkthdr.rcvif = NULL; 2163 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2164 if (outif) 2165 icmp6_ifoutstat_inc(outif, type, code); 2166 2167 return; 2168 2169 bad: 2170 m_freem(m); 2171 return; 2172 } 2173 2174 void 2175 icmp6_fasttimo(void) 2176 { 2177 2178 mld_fasttimo(); 2179 } 2180 2181 void 2182 icmp6_slowtimo(void) 2183 { 2184 2185 mld_slowtimo(); 2186 } 2187 2188 static const char * 2189 icmp6_redirect_diag(struct in6_addr *src6, struct in6_addr *dst6, 2190 struct in6_addr *tgt6) 2191 { 2192 static char buf[1024]; 2193 char ip6bufs[INET6_ADDRSTRLEN]; 2194 char ip6bufd[INET6_ADDRSTRLEN]; 2195 char ip6buft[INET6_ADDRSTRLEN]; 2196 snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)", 2197 ip6_sprintf(ip6bufs, src6), ip6_sprintf(ip6bufd, dst6), 2198 ip6_sprintf(ip6buft, tgt6)); 2199 return buf; 2200 } 2201 2202 void 2203 icmp6_redirect_input(struct mbuf *m, int off) 2204 { 2205 struct ifnet *ifp; 2206 struct ip6_hdr *ip6; 2207 struct nd_redirect *nd_rd; 2208 struct in6_addr src6, redtgt6, reddst6; 2209 union nd_opts ndopts; 2210 char ip6buf[INET6_ADDRSTRLEN]; 2211 char *lladdr; 2212 int icmp6len, is_onlink, is_router, lladdrlen; 2213 2214 M_ASSERTPKTHDR(m); 2215 KASSERT(m->m_pkthdr.rcvif != NULL, ("%s: no rcvif", __func__)); 2216 2217 /* XXX if we are router, we don't update route by icmp6 redirect */ 2218 if (V_ip6_forwarding) 2219 goto freeit; 2220 if (!V_icmp6_rediraccept) 2221 goto freeit; 2222 2223 /* RFC 6980: Nodes MUST silently ignore fragments */ 2224 if(m->m_flags & M_FRAGMENTED) 2225 goto freeit; 2226 2227 ip6 = mtod(m, struct ip6_hdr *); 2228 icmp6len = ntohs(ip6->ip6_plen); 2229 if (m->m_len < off + icmp6len) { 2230 m = m_pullup(m, off + icmp6len); 2231 if (m == NULL) { 2232 IP6STAT_INC(ip6s_exthdrtoolong); 2233 return; 2234 } 2235 } 2236 ip6 = mtod(m, struct ip6_hdr *); 2237 nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off); 2238 2239 ifp = m->m_pkthdr.rcvif; 2240 redtgt6 = nd_rd->nd_rd_target; 2241 reddst6 = nd_rd->nd_rd_dst; 2242 2243 if (in6_setscope(&redtgt6, ifp, NULL) || 2244 in6_setscope(&reddst6, ifp, NULL)) { 2245 goto freeit; 2246 } 2247 2248 /* validation */ 2249 src6 = ip6->ip6_src; 2250 if (!IN6_IS_ADDR_LINKLOCAL(&src6)) { 2251 nd6log((LOG_ERR, 2252 "ICMP6 redirect sent from %s rejected; " 2253 "must be from linklocal\n", 2254 ip6_sprintf(ip6buf, &src6))); 2255 goto bad; 2256 } 2257 if (__predict_false(ip6->ip6_hlim != 255)) { 2258 ICMP6STAT_INC(icp6s_invlhlim); 2259 nd6log((LOG_ERR, 2260 "ICMP6 redirect sent from %s rejected; " 2261 "hlim=%d (must be 255)\n", 2262 ip6_sprintf(ip6buf, &src6), ip6->ip6_hlim)); 2263 goto bad; 2264 } 2265 { 2266 /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */ 2267 struct nhop_object *nh; 2268 struct in6_addr kdst; 2269 uint32_t scopeid; 2270 2271 in6_splitscope(&reddst6, &kdst, &scopeid); 2272 NET_EPOCH_ASSERT(); 2273 nh = fib6_lookup(ifp->if_fib, &kdst, scopeid, 0, 0); 2274 if (nh != NULL) { 2275 struct in6_addr nh_addr; 2276 nh_addr = ifatoia6(nh->nh_ifa)->ia_addr.sin6_addr; 2277 if ((nh->nh_flags & NHF_GATEWAY) == 0) { 2278 nd6log((LOG_ERR, 2279 "ICMP6 redirect rejected; no route " 2280 "with inet6 gateway found for redirect dst: %s\n", 2281 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2282 goto bad; 2283 } 2284 2285 /* 2286 * Embed scope zone id into next hop address. 2287 */ 2288 nh_addr = nh->gw6_sa.sin6_addr; 2289 2290 if (IN6_ARE_ADDR_EQUAL(&src6, &nh_addr) == 0) { 2291 nd6log((LOG_ERR, 2292 "ICMP6 redirect rejected; " 2293 "not equal to gw-for-src=%s (must be same): " 2294 "%s\n", 2295 ip6_sprintf(ip6buf, &nh_addr), 2296 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2297 goto bad; 2298 } 2299 } else { 2300 nd6log((LOG_ERR, 2301 "ICMP6 redirect rejected; " 2302 "no route found for redirect dst: %s\n", 2303 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2304 goto bad; 2305 } 2306 } 2307 if (IN6_IS_ADDR_MULTICAST(&reddst6)) { 2308 nd6log((LOG_ERR, 2309 "ICMP6 redirect rejected; " 2310 "redirect dst must be unicast: %s\n", 2311 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2312 goto bad; 2313 } 2314 2315 is_router = is_onlink = 0; 2316 if (IN6_IS_ADDR_LINKLOCAL(&redtgt6)) 2317 is_router = 1; /* router case */ 2318 if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0) 2319 is_onlink = 1; /* on-link destination case */ 2320 if (!is_router && !is_onlink) { 2321 nd6log((LOG_ERR, 2322 "ICMP6 redirect rejected; " 2323 "neither router case nor onlink case: %s\n", 2324 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2325 goto bad; 2326 } 2327 2328 icmp6len -= sizeof(*nd_rd); 2329 nd6_option_init(nd_rd + 1, icmp6len, &ndopts); 2330 if (nd6_options(&ndopts) < 0) { 2331 nd6log((LOG_INFO, "%s: invalid ND option, rejected: %s\n", 2332 __func__, icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2333 /* nd6_options have incremented stats */ 2334 goto freeit; 2335 } 2336 2337 lladdr = NULL; 2338 lladdrlen = 0; 2339 if (ndopts.nd_opts_tgt_lladdr) { 2340 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 2341 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 2342 } 2343 2344 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 2345 nd6log((LOG_INFO, "%s: lladdrlen mismatch for %s " 2346 "(if %d, icmp6 packet %d): %s\n", 2347 __func__, ip6_sprintf(ip6buf, &redtgt6), 2348 ifp->if_addrlen, lladdrlen - 2, 2349 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2350 goto bad; 2351 } 2352 2353 /* Validation passed. */ 2354 2355 /* RFC 2461 8.3 */ 2356 nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT, 2357 is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER); 2358 2359 /* 2360 * Install a gateway route in the better-router case or an interface 2361 * route in the on-link-destination case. 2362 */ 2363 { 2364 struct sockaddr_in6 sdst; 2365 struct sockaddr_in6 sgw; 2366 struct sockaddr_in6 ssrc; 2367 struct sockaddr *gw; 2368 int rt_flags; 2369 u_int fibnum; 2370 2371 bzero(&sdst, sizeof(sdst)); 2372 bzero(&ssrc, sizeof(ssrc)); 2373 sdst.sin6_family = ssrc.sin6_family = AF_INET6; 2374 sdst.sin6_len = ssrc.sin6_len = sizeof(struct sockaddr_in6); 2375 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr)); 2376 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr)); 2377 rt_flags = 0; 2378 if (is_router) { 2379 bzero(&sgw, sizeof(sgw)); 2380 sgw.sin6_family = AF_INET6; 2381 sgw.sin6_len = sizeof(struct sockaddr_in6); 2382 bcopy(&redtgt6, &sgw.sin6_addr, 2383 sizeof(struct in6_addr)); 2384 gw = (struct sockaddr *)&sgw; 2385 rt_flags |= RTF_GATEWAY; 2386 } else 2387 gw = ifp->if_addr->ifa_addr; 2388 for (fibnum = 0; fibnum < rt_numfibs; fibnum++) 2389 rib_add_redirect(fibnum, (struct sockaddr *)&sdst, gw, 2390 (struct sockaddr *)&ssrc, ifp, rt_flags, 2391 V_icmp6_redirtimeout); 2392 } 2393 /* finally update cached route in each socket via pfctlinput */ 2394 { 2395 struct sockaddr_in6 sdst; 2396 2397 bzero(&sdst, sizeof(sdst)); 2398 sdst.sin6_family = AF_INET6; 2399 sdst.sin6_len = sizeof(struct sockaddr_in6); 2400 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr)); 2401 pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst); 2402 } 2403 2404 freeit: 2405 m_freem(m); 2406 return; 2407 2408 bad: 2409 ICMP6STAT_INC(icp6s_badredirect); 2410 m_freem(m); 2411 } 2412 2413 void 2414 icmp6_redirect_output(struct mbuf *m0, struct nhop_object *nh) 2415 { 2416 struct ifnet *ifp; /* my outgoing interface */ 2417 struct in6_addr *ifp_ll6; 2418 struct in6_addr *router_ll6; 2419 struct ip6_hdr *sip6; /* m0 as struct ip6_hdr */ 2420 struct mbuf *m = NULL; /* newly allocated one */ 2421 struct m_tag *mtag; 2422 struct ip6_hdr *ip6; /* m as struct ip6_hdr */ 2423 struct nd_redirect *nd_rd; 2424 struct llentry *ln = NULL; 2425 size_t maxlen; 2426 u_char *p; 2427 struct ifnet *outif = NULL; 2428 struct sockaddr_in6 src_sa; 2429 2430 icmp6_errcount(ND_REDIRECT, 0); 2431 2432 /* if we are not router, we don't send icmp6 redirect */ 2433 if (!V_ip6_forwarding) 2434 goto fail; 2435 2436 /* sanity check */ 2437 if (!m0 || !nh || !(NH_IS_VALID(nh)) || !(ifp = nh->nh_ifp)) 2438 goto fail; 2439 2440 /* 2441 * Address check: 2442 * the source address must identify a neighbor, and 2443 * the destination address must not be a multicast address 2444 * [RFC 2461, sec 8.2] 2445 */ 2446 sip6 = mtod(m0, struct ip6_hdr *); 2447 bzero(&src_sa, sizeof(src_sa)); 2448 src_sa.sin6_family = AF_INET6; 2449 src_sa.sin6_len = sizeof(src_sa); 2450 src_sa.sin6_addr = sip6->ip6_src; 2451 if (nd6_is_addr_neighbor(&src_sa, ifp) == 0) 2452 goto fail; 2453 if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst)) 2454 goto fail; /* what should we do here? */ 2455 2456 /* rate limit */ 2457 if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0)) 2458 goto fail; 2459 2460 /* 2461 * Since we are going to append up to 1280 bytes (= IPV6_MMTU), 2462 * we almost always ask for an mbuf cluster for simplicity. 2463 * (MHLEN < IPV6_MMTU is almost always true) 2464 */ 2465 #if IPV6_MMTU >= MCLBYTES 2466 # error assumption failed about IPV6_MMTU and MCLBYTES 2467 #endif 2468 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 2469 if (m == NULL) 2470 goto fail; 2471 M_SETFIB(m, M_GETFIB(m0)); 2472 maxlen = M_TRAILINGSPACE(m); 2473 maxlen = min(IPV6_MMTU, maxlen); 2474 /* just for safety */ 2475 if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) + 2476 ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) { 2477 goto fail; 2478 } 2479 2480 { 2481 /* get ip6 linklocal address for ifp(my outgoing interface). */ 2482 struct in6_ifaddr *ia; 2483 if ((ia = in6ifa_ifpforlinklocal(ifp, 2484 IN6_IFF_NOTREADY| 2485 IN6_IFF_ANYCAST)) == NULL) 2486 goto fail; 2487 ifp_ll6 = &ia->ia_addr.sin6_addr; 2488 /* XXXRW: reference released prematurely. */ 2489 ifa_free(&ia->ia_ifa); 2490 } 2491 2492 /* get ip6 linklocal address for the router. */ 2493 if (nh->nh_flags & NHF_GATEWAY) { 2494 struct sockaddr_in6 *sin6; 2495 sin6 = &nh->gw6_sa; 2496 router_ll6 = &sin6->sin6_addr; 2497 if (!IN6_IS_ADDR_LINKLOCAL(router_ll6)) 2498 router_ll6 = (struct in6_addr *)NULL; 2499 } else 2500 router_ll6 = (struct in6_addr *)NULL; 2501 2502 /* ip6 */ 2503 ip6 = mtod(m, struct ip6_hdr *); 2504 ip6->ip6_flow = 0; 2505 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2506 ip6->ip6_vfc |= IPV6_VERSION; 2507 /* ip6->ip6_plen will be set later */ 2508 ip6->ip6_nxt = IPPROTO_ICMPV6; 2509 ip6->ip6_hlim = 255; 2510 /* ip6->ip6_src must be linklocal addr for my outgoing if. */ 2511 bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr)); 2512 bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr)); 2513 2514 /* ND Redirect */ 2515 nd_rd = (struct nd_redirect *)(ip6 + 1); 2516 nd_rd->nd_rd_type = ND_REDIRECT; 2517 nd_rd->nd_rd_code = 0; 2518 nd_rd->nd_rd_reserved = 0; 2519 if (nh->nh_flags & NHF_GATEWAY) { 2520 /* 2521 * nd_rd->nd_rd_target must be a link-local address in 2522 * better router cases. 2523 */ 2524 if (!router_ll6) 2525 goto fail; 2526 bcopy(router_ll6, &nd_rd->nd_rd_target, 2527 sizeof(nd_rd->nd_rd_target)); 2528 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2529 sizeof(nd_rd->nd_rd_dst)); 2530 } else { 2531 /* make sure redtgt == reddst */ 2532 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target, 2533 sizeof(nd_rd->nd_rd_target)); 2534 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2535 sizeof(nd_rd->nd_rd_dst)); 2536 } 2537 2538 p = (u_char *)(nd_rd + 1); 2539 2540 if (!router_ll6) 2541 goto nolladdropt; 2542 2543 { 2544 /* target lladdr option */ 2545 int len; 2546 struct nd_opt_hdr *nd_opt; 2547 char *lladdr; 2548 2549 ln = nd6_lookup(router_ll6, LLE_SF(AF_INET6, 0), ifp); 2550 if (ln == NULL) 2551 goto nolladdropt; 2552 2553 len = sizeof(*nd_opt) + ifp->if_addrlen; 2554 len = (len + 7) & ~7; /* round by 8 */ 2555 /* safety check */ 2556 if (len + (p - (u_char *)ip6) > maxlen) 2557 goto nolladdropt; 2558 2559 if (ln->la_flags & LLE_VALID) { 2560 nd_opt = (struct nd_opt_hdr *)p; 2561 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 2562 nd_opt->nd_opt_len = len >> 3; 2563 lladdr = (char *)(nd_opt + 1); 2564 bcopy(ln->ll_addr, lladdr, ifp->if_addrlen); 2565 p += len; 2566 } 2567 } 2568 nolladdropt: 2569 if (ln != NULL) 2570 LLE_RUNLOCK(ln); 2571 2572 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2573 2574 /* just to be safe */ 2575 #ifdef M_DECRYPTED /*not openbsd*/ 2576 if (m0->m_flags & M_DECRYPTED) 2577 goto noredhdropt; 2578 #endif 2579 if (p - (u_char *)ip6 > maxlen) 2580 goto noredhdropt; 2581 2582 { 2583 /* redirected header option */ 2584 int len; 2585 struct nd_opt_rd_hdr *nd_opt_rh; 2586 2587 /* 2588 * compute the maximum size for icmp6 redirect header option. 2589 * XXX room for auth header? 2590 */ 2591 len = maxlen - (p - (u_char *)ip6); 2592 len &= ~7; 2593 2594 /* This is just for simplicity. */ 2595 if (m0->m_pkthdr.len != m0->m_len) { 2596 if (m0->m_next) { 2597 m_freem(m0->m_next); 2598 m0->m_next = NULL; 2599 } 2600 m0->m_pkthdr.len = m0->m_len; 2601 } 2602 2603 /* 2604 * Redirected header option spec (RFC2461 4.6.3) talks nothing 2605 * about padding/truncate rule for the original IP packet. 2606 * From the discussion on IPv6imp in Feb 1999, 2607 * the consensus was: 2608 * - "attach as much as possible" is the goal 2609 * - pad if not aligned (original size can be guessed by 2610 * original ip6 header) 2611 * Following code adds the padding if it is simple enough, 2612 * and truncates if not. 2613 */ 2614 if (m0->m_next || m0->m_pkthdr.len != m0->m_len) 2615 panic("assumption failed in %s:%d", __FILE__, 2616 __LINE__); 2617 2618 if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) { 2619 /* not enough room, truncate */ 2620 m0->m_pkthdr.len = m0->m_len = len - 2621 sizeof(*nd_opt_rh); 2622 } else { 2623 /* enough room, pad or truncate */ 2624 size_t extra; 2625 2626 extra = m0->m_pkthdr.len % 8; 2627 if (extra) { 2628 /* pad if easy enough, truncate if not */ 2629 if (8 - extra <= M_TRAILINGSPACE(m0)) { 2630 /* pad */ 2631 m0->m_len += (8 - extra); 2632 m0->m_pkthdr.len += (8 - extra); 2633 } else { 2634 /* truncate */ 2635 m0->m_pkthdr.len -= extra; 2636 m0->m_len -= extra; 2637 } 2638 } 2639 len = m0->m_pkthdr.len + sizeof(*nd_opt_rh); 2640 m0->m_pkthdr.len = m0->m_len = len - 2641 sizeof(*nd_opt_rh); 2642 } 2643 2644 nd_opt_rh = (struct nd_opt_rd_hdr *)p; 2645 bzero(nd_opt_rh, sizeof(*nd_opt_rh)); 2646 nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER; 2647 nd_opt_rh->nd_opt_rh_len = len >> 3; 2648 p += sizeof(*nd_opt_rh); 2649 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2650 2651 /* connect m0 to m */ 2652 m_tag_delete_chain(m0, NULL); 2653 m0->m_flags &= ~M_PKTHDR; 2654 m->m_next = m0; 2655 m->m_pkthdr.len = m->m_len + m0->m_len; 2656 m0 = NULL; 2657 } 2658 noredhdropt:; 2659 if (m0) { 2660 m_freem(m0); 2661 m0 = NULL; 2662 } 2663 2664 /* XXX: clear embedded link IDs in the inner header */ 2665 in6_clearscope(&sip6->ip6_src); 2666 in6_clearscope(&sip6->ip6_dst); 2667 in6_clearscope(&nd_rd->nd_rd_target); 2668 in6_clearscope(&nd_rd->nd_rd_dst); 2669 2670 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr)); 2671 2672 nd_rd->nd_rd_cksum = 0; 2673 nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2674 sizeof(*ip6), ntohs(ip6->ip6_plen)); 2675 2676 if (send_sendso_input_hook != NULL) { 2677 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, sizeof(unsigned short), 2678 M_NOWAIT); 2679 if (mtag == NULL) 2680 goto fail; 2681 *(unsigned short *)(mtag + 1) = nd_rd->nd_rd_type; 2682 m_tag_prepend(m, mtag); 2683 } 2684 2685 /* send the packet to outside... */ 2686 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2687 if (outif) { 2688 icmp6_ifstat_inc(outif, ifs6_out_msg); 2689 icmp6_ifstat_inc(outif, ifs6_out_redirect); 2690 } 2691 ICMP6STAT_INC(icp6s_outhist[ND_REDIRECT]); 2692 2693 return; 2694 2695 fail: 2696 if (m) 2697 m_freem(m); 2698 if (m0) 2699 m_freem(m0); 2700 } 2701 2702 /* 2703 * ICMPv6 socket option processing. 2704 */ 2705 int 2706 icmp6_ctloutput(struct socket *so, struct sockopt *sopt) 2707 { 2708 int error = 0; 2709 int optlen; 2710 struct inpcb *inp = sotoinpcb(so); 2711 int level, op, optname; 2712 2713 if (sopt) { 2714 level = sopt->sopt_level; 2715 op = sopt->sopt_dir; 2716 optname = sopt->sopt_name; 2717 optlen = sopt->sopt_valsize; 2718 } else 2719 level = op = optname = optlen = 0; 2720 2721 if (level != IPPROTO_ICMPV6) { 2722 return EINVAL; 2723 } 2724 2725 switch (op) { 2726 case PRCO_SETOPT: 2727 switch (optname) { 2728 case ICMP6_FILTER: 2729 { 2730 struct icmp6_filter ic6f; 2731 2732 if (optlen != sizeof(ic6f)) { 2733 error = EMSGSIZE; 2734 break; 2735 } 2736 error = sooptcopyin(sopt, &ic6f, optlen, optlen); 2737 if (error == 0) { 2738 INP_WLOCK(inp); 2739 *inp->in6p_icmp6filt = ic6f; 2740 INP_WUNLOCK(inp); 2741 } 2742 break; 2743 } 2744 2745 default: 2746 error = ENOPROTOOPT; 2747 break; 2748 } 2749 break; 2750 2751 case PRCO_GETOPT: 2752 switch (optname) { 2753 case ICMP6_FILTER: 2754 { 2755 struct icmp6_filter ic6f; 2756 2757 INP_RLOCK(inp); 2758 ic6f = *inp->in6p_icmp6filt; 2759 INP_RUNLOCK(inp); 2760 error = sooptcopyout(sopt, &ic6f, sizeof(ic6f)); 2761 break; 2762 } 2763 2764 default: 2765 error = ENOPROTOOPT; 2766 break; 2767 } 2768 break; 2769 } 2770 2771 return (error); 2772 } 2773 2774 /* 2775 * Perform rate limit check. 2776 * Returns 0 if it is okay to send the icmp6 packet. 2777 * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate 2778 * limitation. 2779 * 2780 * XXX per-destination/type check necessary? 2781 * 2782 * dst - not used at this moment 2783 * type - not used at this moment 2784 * code - not used at this moment 2785 */ 2786 static int 2787 icmp6_ratelimit(const struct in6_addr *dst, const int type, 2788 const int code) 2789 { 2790 int ret; 2791 2792 ret = 0; /* okay to send */ 2793 2794 /* PPS limit */ 2795 if (!ppsratecheck(&V_icmp6errppslim_last, &V_icmp6errpps_count, 2796 V_icmp6errppslim)) { 2797 /* The packet is subject to rate limit */ 2798 ret++; 2799 } 2800 2801 return ret; 2802 } 2803