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 ipproto_ctlinput_t *ip6_ctlprotox[]; 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 u_int8_t nxt = eip6->ip6_nxt; 926 int eoff = off + sizeof(struct icmp6_hdr) + 927 sizeof(struct ip6_hdr); 928 struct ip6ctlparam ip6cp; 929 int icmp6type = icmp6->icmp6_type; 930 struct ip6_frag *fh; 931 struct ip6_rthdr *rth; 932 struct ip6_rthdr0 *rth0; 933 int rthlen; 934 935 while (1) { /* XXX: should avoid infinite loop explicitly? */ 936 struct ip6_ext *eh; 937 938 switch (nxt) { 939 case IPPROTO_HOPOPTS: 940 case IPPROTO_DSTOPTS: 941 case IPPROTO_AH: 942 if (m->m_len < eoff + sizeof(struct ip6_ext)) { 943 m = m_pullup(m, eoff + 944 sizeof(struct ip6_ext)); 945 if (m == NULL) { 946 IP6STAT_INC(ip6s_exthdrtoolong); 947 *mp = m; 948 return (-1); 949 } 950 } 951 eh = (struct ip6_ext *) 952 (mtod(m, caddr_t) + eoff); 953 if (nxt == IPPROTO_AH) 954 eoff += (eh->ip6e_len + 2) << 2; 955 else 956 eoff += (eh->ip6e_len + 1) << 3; 957 nxt = eh->ip6e_nxt; 958 break; 959 case IPPROTO_ROUTING: 960 /* 961 * When the erroneous packet contains a 962 * routing header, we should examine the 963 * header to determine the final destination. 964 * Otherwise, we can't properly update 965 * information that depends on the final 966 * destination (e.g. path MTU). 967 */ 968 if (m->m_len < eoff + sizeof(*rth)) { 969 m = m_pullup(m, eoff + sizeof(*rth)); 970 if (m == NULL) { 971 IP6STAT_INC(ip6s_exthdrtoolong); 972 *mp = m; 973 return (-1); 974 } 975 } 976 rth = (struct ip6_rthdr *) 977 (mtod(m, caddr_t) + eoff); 978 rthlen = (rth->ip6r_len + 1) << 3; 979 /* 980 * XXX: currently there is no 981 * officially defined type other 982 * than type-0. 983 * Note that if the segment left field 984 * is 0, all intermediate hops must 985 * have been passed. 986 */ 987 if (rth->ip6r_segleft && 988 rth->ip6r_type == IPV6_RTHDR_TYPE_0) { 989 int hops; 990 991 if (m->m_len < eoff + rthlen) { 992 m = m_pullup(m, eoff + rthlen); 993 if (m == NULL) { 994 IP6STAT_INC( 995 ip6s_exthdrtoolong); 996 *mp = m; 997 return (-1); 998 } 999 } 1000 rth0 = (struct ip6_rthdr0 *) 1001 (mtod(m, caddr_t) + eoff); 1002 1003 /* just ignore a bogus header */ 1004 if ((rth0->ip6r0_len % 2) == 0 && 1005 (hops = rth0->ip6r0_len/2)) 1006 icmp6dst.sin6_addr = *((struct in6_addr *)(rth0 + 1) + (hops - 1)); 1007 } 1008 eoff += rthlen; 1009 nxt = rth->ip6r_nxt; 1010 break; 1011 case IPPROTO_FRAGMENT: 1012 if (m->m_len < eoff + sizeof(struct ip6_frag)) { 1013 m = m_pullup(m, eoff + 1014 sizeof(struct ip6_frag)); 1015 if (m == NULL) { 1016 IP6STAT_INC(ip6s_exthdrtoolong); 1017 *mp = m; 1018 return (-1); 1019 } 1020 } 1021 fh = (struct ip6_frag *)(mtod(m, caddr_t) + 1022 eoff); 1023 /* 1024 * Data after a fragment header is meaningless 1025 * unless it is the first fragment, but 1026 * we'll go to the notify label for path MTU 1027 * discovery. 1028 */ 1029 if (fh->ip6f_offlg & IP6F_OFF_MASK) 1030 goto notify; 1031 1032 eoff += sizeof(struct ip6_frag); 1033 nxt = fh->ip6f_nxt; 1034 break; 1035 default: 1036 /* 1037 * This case includes ESP and the No Next 1038 * Header. In such cases going to the notify 1039 * label does not have any meaning 1040 * (i.e. ctlfunc will be NULL), but we go 1041 * anyway since we might have to update 1042 * path MTU information. 1043 */ 1044 goto notify; 1045 } 1046 } 1047 notify: 1048 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 1049 1050 /* 1051 * retrieve parameters from the inner IPv6 header, and convert 1052 * them into sockaddr structures. 1053 * XXX: there is no guarantee that the source or destination 1054 * addresses of the inner packet are in the same scope as 1055 * the addresses of the icmp packet. But there is no other 1056 * way to determine the zone. 1057 */ 1058 eip6 = (struct ip6_hdr *)(icmp6 + 1); 1059 1060 icmp6dst.sin6_len = sizeof(struct sockaddr_in6); 1061 icmp6dst.sin6_family = AF_INET6; 1062 if (IN6_IS_ADDR_UNSPECIFIED(&icmp6dst.sin6_addr)) 1063 icmp6dst.sin6_addr = eip6->ip6_dst; 1064 if (in6_setscope(&icmp6dst.sin6_addr, m->m_pkthdr.rcvif, NULL)) 1065 goto freeit; 1066 bzero(&icmp6src, sizeof(icmp6src)); 1067 icmp6src.sin6_len = sizeof(struct sockaddr_in6); 1068 icmp6src.sin6_family = AF_INET6; 1069 icmp6src.sin6_addr = eip6->ip6_src; 1070 if (in6_setscope(&icmp6src.sin6_addr, m->m_pkthdr.rcvif, NULL)) 1071 goto freeit; 1072 icmp6src.sin6_flowinfo = 1073 (eip6->ip6_flow & IPV6_FLOWLABEL_MASK); 1074 1075 ip6cp.ip6c_m = m; 1076 ip6cp.ip6c_icmp6 = icmp6; 1077 ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1); 1078 ip6cp.ip6c_off = eoff; 1079 ip6cp.ip6c_finaldst = &icmp6dst.sin6_addr; 1080 ip6cp.ip6c_src = &icmp6src; 1081 ip6cp.ip6c_nxt = nxt; 1082 1083 if (icmp6type == ICMP6_PACKET_TOO_BIG) { 1084 notifymtu = ntohl(icmp6->icmp6_mtu); 1085 ip6cp.ip6c_cmdarg = (void *)¬ifymtu; 1086 icmp6_mtudisc_update(&ip6cp, 1); /*XXX*/ 1087 } 1088 1089 if (ip6_ctlprotox[nxt] != NULL) 1090 ip6_ctlprotox[nxt](code, (struct sockaddr *)&icmp6dst, 1091 &ip6cp); 1092 } 1093 *mp = m; 1094 return (0); 1095 1096 freeit: 1097 m_freem(m); 1098 *mp = NULL; 1099 return (-1); 1100 } 1101 1102 void 1103 icmp6_mtudisc_update(struct ip6ctlparam *ip6cp, int validated) 1104 { 1105 struct in6_addr *dst = ip6cp->ip6c_finaldst; 1106 struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6; 1107 struct mbuf *m = ip6cp->ip6c_m; /* will be necessary for scope issue */ 1108 u_int mtu = ntohl(icmp6->icmp6_mtu); 1109 struct in_conninfo inc; 1110 uint32_t max_mtu; 1111 1112 #if 0 1113 /* 1114 * RFC2460 section 5, last paragraph. 1115 * even though minimum link MTU for IPv6 is IPV6_MMTU, 1116 * we may see ICMPv6 too big with mtu < IPV6_MMTU 1117 * due to packet translator in the middle. 1118 * see ip6_output() and ip6_getpmtu() "alwaysfrag" case for 1119 * special handling. 1120 */ 1121 if (mtu < IPV6_MMTU) 1122 return; 1123 #endif 1124 1125 /* 1126 * we reject ICMPv6 too big with abnormally small value. 1127 * XXX what is the good definition of "abnormally small"? 1128 */ 1129 if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8) 1130 return; 1131 1132 if (!validated) 1133 return; 1134 1135 /* 1136 * In case the suggested mtu is less than IPV6_MMTU, we 1137 * only need to remember that it was for above mentioned 1138 * "alwaysfrag" case. 1139 * Try to be as close to the spec as possible. 1140 */ 1141 if (mtu < IPV6_MMTU) 1142 mtu = IPV6_MMTU - 8; 1143 1144 bzero(&inc, sizeof(inc)); 1145 inc.inc_fibnum = M_GETFIB(m); 1146 inc.inc_flags |= INC_ISIPV6; 1147 inc.inc6_faddr = *dst; 1148 if (in6_setscope(&inc.inc6_faddr, m->m_pkthdr.rcvif, NULL)) 1149 return; 1150 1151 max_mtu = tcp_hc_getmtu(&inc); 1152 if (max_mtu == 0) 1153 max_mtu = tcp_maxmtu6(&inc, NULL); 1154 1155 if (mtu < max_mtu) { 1156 tcp_hc_updatemtu(&inc, mtu); 1157 ICMP6STAT_INC(icp6s_pmtuchg); 1158 } 1159 } 1160 1161 /* 1162 * Process a Node Information Query packet, based on 1163 * draft-ietf-ipngwg-icmp-name-lookups-07. 1164 * 1165 * Spec incompatibilities: 1166 * - IPv6 Subject address handling 1167 * - IPv4 Subject address handling support missing 1168 * - Proxy reply (answer even if it's not for me) 1169 * - joins NI group address at in6_ifattach() time only, does not cope 1170 * with hostname changes by sethostname(3) 1171 */ 1172 static struct mbuf * 1173 ni6_input(struct mbuf *m, int off, struct prison *pr) 1174 { 1175 struct icmp6_nodeinfo *ni6, *nni6; 1176 struct mbuf *n = NULL; 1177 u_int16_t qtype; 1178 int subjlen; 1179 int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); 1180 struct ni_reply_fqdn *fqdn; 1181 int addrs; /* for NI_QTYPE_NODEADDR */ 1182 struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */ 1183 struct in6_addr in6_subj; /* subject address */ 1184 struct ip6_hdr *ip6; 1185 int oldfqdn = 0; /* if 1, return pascal string (03 draft) */ 1186 char *subj = NULL; 1187 struct in6_ifaddr *ia6 = NULL; 1188 1189 ip6 = mtod(m, struct ip6_hdr *); 1190 ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off); 1191 1192 /* 1193 * Validate IPv6 source address. 1194 * The default configuration MUST be to refuse answering queries from 1195 * global-scope addresses according to RFC4602. 1196 * Notes: 1197 * - it's not very clear what "refuse" means; this implementation 1198 * simply drops it. 1199 * - it's not very easy to identify global-scope (unicast) addresses 1200 * since there are many prefixes for them. It should be safer 1201 * and in practice sufficient to check "all" but loopback and 1202 * link-local (note that site-local unicast was deprecated and 1203 * ULA is defined as global scope-wise) 1204 */ 1205 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_GLOBALOK) == 0 && 1206 !IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) && 1207 !IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) 1208 goto bad; 1209 1210 /* 1211 * Validate IPv6 destination address. 1212 * 1213 * The Responder must discard the Query without further processing 1214 * unless it is one of the Responder's unicast or anycast addresses, or 1215 * a link-local scope multicast address which the Responder has joined. 1216 * [RFC4602, Section 5.] 1217 */ 1218 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 1219 if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst)) 1220 goto bad; 1221 /* else it's a link-local multicast, fine */ 1222 } else { /* unicast or anycast */ 1223 ia6 = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */, false); 1224 if (ia6 == NULL) 1225 goto bad; /* XXX impossible */ 1226 1227 if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) && 1228 !(V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK)) { 1229 nd6log((LOG_DEBUG, "ni6_input: ignore node info to " 1230 "a temporary address in %s:%d", 1231 __FILE__, __LINE__)); 1232 goto bad; 1233 } 1234 } 1235 1236 /* validate query Subject field. */ 1237 qtype = ntohs(ni6->ni_qtype); 1238 subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo); 1239 switch (qtype) { 1240 case NI_QTYPE_NOOP: 1241 case NI_QTYPE_SUPTYPES: 1242 /* 07 draft */ 1243 if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0) 1244 break; 1245 /* FALLTHROUGH */ 1246 case NI_QTYPE_FQDN: 1247 case NI_QTYPE_NODEADDR: 1248 case NI_QTYPE_IPV4ADDR: 1249 switch (ni6->ni_code) { 1250 case ICMP6_NI_SUBJ_IPV6: 1251 #if ICMP6_NI_SUBJ_IPV6 != 0 1252 case 0: 1253 #endif 1254 /* 1255 * backward compatibility - try to accept 03 draft 1256 * format, where no Subject is present. 1257 */ 1258 if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 && 1259 subjlen == 0) { 1260 oldfqdn++; 1261 break; 1262 } 1263 #if ICMP6_NI_SUBJ_IPV6 != 0 1264 if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6) 1265 goto bad; 1266 #endif 1267 1268 if (subjlen != sizeof(struct in6_addr)) 1269 goto bad; 1270 1271 /* 1272 * Validate Subject address. 1273 * 1274 * Not sure what exactly "address belongs to the node" 1275 * means in the spec, is it just unicast, or what? 1276 * 1277 * At this moment we consider Subject address as 1278 * "belong to the node" if the Subject address equals 1279 * to the IPv6 destination address; validation for 1280 * IPv6 destination address should have done enough 1281 * check for us. 1282 * 1283 * We do not do proxy at this moment. 1284 */ 1285 m_copydata(m, off + sizeof(struct icmp6_nodeinfo), 1286 subjlen, (caddr_t)&in6_subj); 1287 if (in6_setscope(&in6_subj, m->m_pkthdr.rcvif, NULL)) 1288 goto bad; 1289 1290 subj = (char *)&in6_subj; 1291 if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &in6_subj)) 1292 break; 1293 1294 /* 1295 * XXX if we are to allow other cases, we should really 1296 * be careful about scope here. 1297 * basically, we should disallow queries toward IPv6 1298 * destination X with subject Y, 1299 * if scope(X) > scope(Y). 1300 * if we allow scope(X) > scope(Y), it will result in 1301 * information leakage across scope boundary. 1302 */ 1303 goto bad; 1304 1305 case ICMP6_NI_SUBJ_FQDN: 1306 /* 1307 * Validate Subject name with gethostname(3). 1308 * 1309 * The behavior may need some debate, since: 1310 * - we are not sure if the node has FQDN as 1311 * hostname (returned by gethostname(3)). 1312 * - the code does wildcard match for truncated names. 1313 * however, we are not sure if we want to perform 1314 * wildcard match, if gethostname(3) side has 1315 * truncated hostname. 1316 */ 1317 mtx_lock(&pr->pr_mtx); 1318 n = ni6_nametodns(pr->pr_hostname, 1319 strlen(pr->pr_hostname), 0); 1320 mtx_unlock(&pr->pr_mtx); 1321 if (!n || n->m_next || n->m_len == 0) 1322 goto bad; 1323 if (m->m_len < off + sizeof(struct icmp6_nodeinfo) + 1324 subjlen) { 1325 m = m_pullup(m, off + 1326 sizeof(struct icmp6_nodeinfo) + subjlen); 1327 if (m == NULL) { 1328 IP6STAT_INC(ip6s_exthdrtoolong); 1329 goto bad; 1330 } 1331 } 1332 /* ip6 possibly invalid but not used after. */ 1333 ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off); 1334 subj = (char *)(mtod(m, caddr_t) + off + 1335 sizeof(struct icmp6_nodeinfo)); 1336 if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *), 1337 n->m_len)) { 1338 goto bad; 1339 } 1340 m_freem(n); 1341 n = NULL; 1342 break; 1343 1344 case ICMP6_NI_SUBJ_IPV4: /* XXX: to be implemented? */ 1345 default: 1346 goto bad; 1347 } 1348 break; 1349 } 1350 1351 /* refuse based on configuration. XXX ICMP6_NI_REFUSED? */ 1352 switch (qtype) { 1353 case NI_QTYPE_FQDN: 1354 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_FQDNOK) == 0) 1355 goto bad; 1356 break; 1357 case NI_QTYPE_NODEADDR: 1358 case NI_QTYPE_IPV4ADDR: 1359 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_NODEADDROK) == 0) 1360 goto bad; 1361 break; 1362 } 1363 1364 /* guess reply length */ 1365 switch (qtype) { 1366 case NI_QTYPE_NOOP: 1367 break; /* no reply data */ 1368 case NI_QTYPE_SUPTYPES: 1369 replylen += sizeof(u_int32_t); 1370 break; 1371 case NI_QTYPE_FQDN: 1372 /* XXX will append an mbuf */ 1373 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); 1374 break; 1375 case NI_QTYPE_NODEADDR: 1376 addrs = ni6_addrs(ni6, m, &ifp, (struct in6_addr *)subj); 1377 if ((replylen += addrs * (sizeof(struct in6_addr) + 1378 sizeof(u_int32_t))) > MCLBYTES) 1379 replylen = MCLBYTES; /* XXX: will truncate pkt later */ 1380 break; 1381 case NI_QTYPE_IPV4ADDR: 1382 /* unsupported - should respond with unknown Qtype? */ 1383 break; 1384 default: 1385 /* 1386 * XXX: We must return a reply with the ICMP6 code 1387 * `unknown Qtype' in this case. However we regard the case 1388 * as an FQDN query for backward compatibility. 1389 * Older versions set a random value to this field, 1390 * so it rarely varies in the defined qtypes. 1391 * But the mechanism is not reliable... 1392 * maybe we should obsolete older versions. 1393 */ 1394 qtype = NI_QTYPE_FQDN; 1395 /* XXX will append an mbuf */ 1396 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); 1397 oldfqdn++; 1398 break; 1399 } 1400 1401 /* Allocate an mbuf to reply. */ 1402 if (replylen > MCLBYTES) { 1403 /* 1404 * XXX: should we try to allocate more? But MCLBYTES 1405 * is probably much larger than IPV6_MMTU... 1406 */ 1407 goto bad; 1408 } 1409 if (replylen > MHLEN) 1410 n = m_getcl(M_NOWAIT, m->m_type, M_PKTHDR); 1411 else 1412 n = m_gethdr(M_NOWAIT, m->m_type); 1413 if (n == NULL) { 1414 m_freem(m); 1415 return (NULL); 1416 } 1417 m_move_pkthdr(n, m); /* just for recvif and FIB */ 1418 n->m_pkthdr.len = n->m_len = replylen; 1419 1420 /* copy mbuf header and IPv6 + Node Information base headers */ 1421 bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr)); 1422 nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1); 1423 bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo)); 1424 1425 /* qtype dependent procedure */ 1426 switch (qtype) { 1427 case NI_QTYPE_NOOP: 1428 nni6->ni_code = ICMP6_NI_SUCCESS; 1429 nni6->ni_flags = 0; 1430 break; 1431 case NI_QTYPE_SUPTYPES: 1432 { 1433 u_int32_t v; 1434 nni6->ni_code = ICMP6_NI_SUCCESS; 1435 nni6->ni_flags = htons(0x0000); /* raw bitmap */ 1436 /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */ 1437 v = (u_int32_t)htonl(0x0000000f); 1438 bcopy(&v, nni6 + 1, sizeof(u_int32_t)); 1439 break; 1440 } 1441 case NI_QTYPE_FQDN: 1442 nni6->ni_code = ICMP6_NI_SUCCESS; 1443 fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) + 1444 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo)); 1445 nni6->ni_flags = 0; /* XXX: meaningless TTL */ 1446 fqdn->ni_fqdn_ttl = 0; /* ditto. */ 1447 /* 1448 * XXX do we really have FQDN in hostname? 1449 */ 1450 mtx_lock(&pr->pr_mtx); 1451 n->m_next = ni6_nametodns(pr->pr_hostname, 1452 strlen(pr->pr_hostname), oldfqdn); 1453 mtx_unlock(&pr->pr_mtx); 1454 if (n->m_next == NULL) 1455 goto bad; 1456 /* XXX we assume that n->m_next is not a chain */ 1457 if (n->m_next->m_next != NULL) 1458 goto bad; 1459 n->m_pkthdr.len += n->m_next->m_len; 1460 break; 1461 case NI_QTYPE_NODEADDR: 1462 { 1463 int lenlim, copied; 1464 1465 nni6->ni_code = ICMP6_NI_SUCCESS; 1466 n->m_pkthdr.len = n->m_len = 1467 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); 1468 lenlim = M_TRAILINGSPACE(n); 1469 copied = ni6_store_addrs(ni6, nni6, ifp, lenlim); 1470 /* XXX: reset mbuf length */ 1471 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + 1472 sizeof(struct icmp6_nodeinfo) + copied; 1473 break; 1474 } 1475 default: 1476 break; /* XXX impossible! */ 1477 } 1478 1479 nni6->ni_type = ICMP6_NI_REPLY; 1480 m_freem(m); 1481 return (n); 1482 1483 bad: 1484 m_freem(m); 1485 if (n) 1486 m_freem(n); 1487 return (NULL); 1488 } 1489 1490 /* 1491 * make a mbuf with DNS-encoded string. no compression support. 1492 * 1493 * XXX names with less than 2 dots (like "foo" or "foo.section") will be 1494 * treated as truncated name (two \0 at the end). this is a wild guess. 1495 * 1496 * old - return pascal string if non-zero 1497 */ 1498 static struct mbuf * 1499 ni6_nametodns(const char *name, int namelen, int old) 1500 { 1501 struct mbuf *m; 1502 char *cp, *ep; 1503 const char *p, *q; 1504 int i, len, nterm; 1505 1506 if (old) 1507 len = namelen + 1; 1508 else 1509 len = MCLBYTES; 1510 1511 /* Because MAXHOSTNAMELEN is usually 256, we use cluster mbuf. */ 1512 if (len > MLEN) 1513 m = m_getcl(M_NOWAIT, MT_DATA, 0); 1514 else 1515 m = m_get(M_NOWAIT, MT_DATA); 1516 if (m == NULL) 1517 goto fail; 1518 1519 if (old) { 1520 m->m_len = len; 1521 *mtod(m, char *) = namelen; 1522 bcopy(name, mtod(m, char *) + 1, namelen); 1523 return m; 1524 } else { 1525 m->m_len = 0; 1526 cp = mtod(m, char *); 1527 ep = mtod(m, char *) + M_TRAILINGSPACE(m); 1528 1529 /* if not certain about my name, return empty buffer */ 1530 if (namelen == 0) 1531 return m; 1532 1533 /* 1534 * guess if it looks like shortened hostname, or FQDN. 1535 * shortened hostname needs two trailing "\0". 1536 */ 1537 i = 0; 1538 for (p = name; p < name + namelen; p++) { 1539 if (*p && *p == '.') 1540 i++; 1541 } 1542 if (i < 2) 1543 nterm = 2; 1544 else 1545 nterm = 1; 1546 1547 p = name; 1548 while (cp < ep && p < name + namelen) { 1549 i = 0; 1550 for (q = p; q < name + namelen && *q && *q != '.'; q++) 1551 i++; 1552 /* result does not fit into mbuf */ 1553 if (cp + i + 1 >= ep) 1554 goto fail; 1555 /* 1556 * DNS label length restriction, RFC1035 page 8. 1557 * "i == 0" case is included here to avoid returning 1558 * 0-length label on "foo..bar". 1559 */ 1560 if (i <= 0 || i >= 64) 1561 goto fail; 1562 *cp++ = i; 1563 bcopy(p, cp, i); 1564 cp += i; 1565 p = q; 1566 if (p < name + namelen && *p == '.') 1567 p++; 1568 } 1569 /* termination */ 1570 if (cp + nterm >= ep) 1571 goto fail; 1572 while (nterm-- > 0) 1573 *cp++ = '\0'; 1574 m->m_len = cp - mtod(m, char *); 1575 return m; 1576 } 1577 1578 panic("should not reach here"); 1579 /* NOTREACHED */ 1580 1581 fail: 1582 if (m) 1583 m_freem(m); 1584 return NULL; 1585 } 1586 1587 /* 1588 * check if two DNS-encoded string matches. takes care of truncated 1589 * form (with \0\0 at the end). no compression support. 1590 * XXX upper/lowercase match (see RFC2065) 1591 */ 1592 static int 1593 ni6_dnsmatch(const char *a, int alen, const char *b, int blen) 1594 { 1595 const char *a0, *b0; 1596 int l; 1597 1598 /* simplest case - need validation? */ 1599 if (alen == blen && bcmp(a, b, alen) == 0) 1600 return 1; 1601 1602 a0 = a; 1603 b0 = b; 1604 1605 /* termination is mandatory */ 1606 if (alen < 2 || blen < 2) 1607 return 0; 1608 if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0') 1609 return 0; 1610 alen--; 1611 blen--; 1612 1613 while (a - a0 < alen && b - b0 < blen) { 1614 if (a - a0 + 1 > alen || b - b0 + 1 > blen) 1615 return 0; 1616 1617 if ((signed char)a[0] < 0 || (signed char)b[0] < 0) 1618 return 0; 1619 /* we don't support compression yet */ 1620 if (a[0] >= 64 || b[0] >= 64) 1621 return 0; 1622 1623 /* truncated case */ 1624 if (a[0] == 0 && a - a0 == alen - 1) 1625 return 1; 1626 if (b[0] == 0 && b - b0 == blen - 1) 1627 return 1; 1628 if (a[0] == 0 || b[0] == 0) 1629 return 0; 1630 1631 if (a[0] != b[0]) 1632 return 0; 1633 l = a[0]; 1634 if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen) 1635 return 0; 1636 if (bcmp(a + 1, b + 1, l) != 0) 1637 return 0; 1638 1639 a += 1 + l; 1640 b += 1 + l; 1641 } 1642 1643 if (a - a0 == alen && b - b0 == blen) 1644 return 1; 1645 else 1646 return 0; 1647 } 1648 1649 /* 1650 * calculate the number of addresses to be returned in the node info reply. 1651 */ 1652 static int 1653 ni6_addrs(struct icmp6_nodeinfo *ni6, struct mbuf *m, struct ifnet **ifpp, 1654 struct in6_addr *subj) 1655 { 1656 struct ifnet *ifp; 1657 struct in6_ifaddr *ifa6; 1658 struct ifaddr *ifa; 1659 int addrs = 0, addrsofif, iffound = 0; 1660 int niflags = ni6->ni_flags; 1661 1662 NET_EPOCH_ASSERT(); 1663 1664 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) { 1665 switch (ni6->ni_code) { 1666 case ICMP6_NI_SUBJ_IPV6: 1667 if (subj == NULL) /* must be impossible... */ 1668 return (0); 1669 break; 1670 default: 1671 /* 1672 * XXX: we only support IPv6 subject address for 1673 * this Qtype. 1674 */ 1675 return (0); 1676 } 1677 } 1678 1679 CK_STAILQ_FOREACH(ifp, &V_ifnet, if_link) { 1680 addrsofif = 0; 1681 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 1682 if (ifa->ifa_addr->sa_family != AF_INET6) 1683 continue; 1684 ifa6 = (struct in6_ifaddr *)ifa; 1685 1686 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 && 1687 IN6_ARE_ADDR_EQUAL(subj, &ifa6->ia_addr.sin6_addr)) 1688 iffound = 1; 1689 1690 /* 1691 * IPv4-mapped addresses can only be returned by a 1692 * Node Information proxy, since they represent 1693 * addresses of IPv4-only nodes, which perforce do 1694 * not implement this protocol. 1695 * [icmp-name-lookups-07, Section 5.4] 1696 * So we don't support NI_NODEADDR_FLAG_COMPAT in 1697 * this function at this moment. 1698 */ 1699 1700 /* What do we have to do about ::1? */ 1701 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { 1702 case IPV6_ADDR_SCOPE_LINKLOCAL: 1703 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) 1704 continue; 1705 break; 1706 case IPV6_ADDR_SCOPE_SITELOCAL: 1707 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) 1708 continue; 1709 break; 1710 case IPV6_ADDR_SCOPE_GLOBAL: 1711 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) 1712 continue; 1713 break; 1714 default: 1715 continue; 1716 } 1717 1718 /* 1719 * check if anycast is okay. 1720 * XXX: just experimental. not in the spec. 1721 */ 1722 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && 1723 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) 1724 continue; /* we need only unicast addresses */ 1725 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && 1726 (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) { 1727 continue; 1728 } 1729 addrsofif++; /* count the address */ 1730 } 1731 if (iffound) { 1732 *ifpp = ifp; 1733 return (addrsofif); 1734 } 1735 1736 addrs += addrsofif; 1737 } 1738 1739 return (addrs); 1740 } 1741 1742 static int 1743 ni6_store_addrs(struct icmp6_nodeinfo *ni6, struct icmp6_nodeinfo *nni6, 1744 struct ifnet *ifp0, int resid) 1745 { 1746 struct ifnet *ifp; 1747 struct in6_ifaddr *ifa6; 1748 struct ifaddr *ifa; 1749 struct ifnet *ifp_dep = NULL; 1750 int copied = 0, allow_deprecated = 0; 1751 u_char *cp = (u_char *)(nni6 + 1); 1752 int niflags = ni6->ni_flags; 1753 u_int32_t ltime; 1754 1755 NET_EPOCH_ASSERT(); 1756 1757 if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL)) 1758 return (0); /* needless to copy */ 1759 1760 ifp = ifp0 ? ifp0 : CK_STAILQ_FIRST(&V_ifnet); 1761 again: 1762 1763 for (; ifp; ifp = CK_STAILQ_NEXT(ifp, if_link)) { 1764 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 1765 if (ifa->ifa_addr->sa_family != AF_INET6) 1766 continue; 1767 ifa6 = (struct in6_ifaddr *)ifa; 1768 1769 if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 && 1770 allow_deprecated == 0) { 1771 /* 1772 * prefererred address should be put before 1773 * deprecated addresses. 1774 */ 1775 1776 /* record the interface for later search */ 1777 if (ifp_dep == NULL) 1778 ifp_dep = ifp; 1779 1780 continue; 1781 } else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 && 1782 allow_deprecated != 0) 1783 continue; /* we now collect deprecated addrs */ 1784 1785 /* What do we have to do about ::1? */ 1786 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { 1787 case IPV6_ADDR_SCOPE_LINKLOCAL: 1788 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) 1789 continue; 1790 break; 1791 case IPV6_ADDR_SCOPE_SITELOCAL: 1792 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) 1793 continue; 1794 break; 1795 case IPV6_ADDR_SCOPE_GLOBAL: 1796 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) 1797 continue; 1798 break; 1799 default: 1800 continue; 1801 } 1802 1803 /* 1804 * check if anycast is okay. 1805 * XXX: just experimental. not in the spec. 1806 */ 1807 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && 1808 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) 1809 continue; 1810 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && 1811 (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) { 1812 continue; 1813 } 1814 1815 /* now we can copy the address */ 1816 if (resid < sizeof(struct in6_addr) + 1817 sizeof(u_int32_t)) { 1818 /* 1819 * We give up much more copy. 1820 * Set the truncate flag and return. 1821 */ 1822 nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE; 1823 return (copied); 1824 } 1825 1826 /* 1827 * Set the TTL of the address. 1828 * The TTL value should be one of the following 1829 * according to the specification: 1830 * 1831 * 1. The remaining lifetime of a DHCP lease on the 1832 * address, or 1833 * 2. The remaining Valid Lifetime of a prefix from 1834 * which the address was derived through Stateless 1835 * Autoconfiguration. 1836 * 1837 * Note that we currently do not support stateful 1838 * address configuration by DHCPv6, so the former 1839 * case can't happen. 1840 */ 1841 if (ifa6->ia6_lifetime.ia6t_expire == 0) 1842 ltime = ND6_INFINITE_LIFETIME; 1843 else { 1844 if (ifa6->ia6_lifetime.ia6t_expire > 1845 time_uptime) 1846 ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_uptime); 1847 else 1848 ltime = 0; 1849 } 1850 1851 bcopy(<ime, cp, sizeof(u_int32_t)); 1852 cp += sizeof(u_int32_t); 1853 1854 /* copy the address itself */ 1855 bcopy(&ifa6->ia_addr.sin6_addr, cp, 1856 sizeof(struct in6_addr)); 1857 in6_clearscope((struct in6_addr *)cp); /* XXX */ 1858 cp += sizeof(struct in6_addr); 1859 1860 resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t)); 1861 copied += (sizeof(struct in6_addr) + sizeof(u_int32_t)); 1862 } 1863 if (ifp0) /* we need search only on the specified IF */ 1864 break; 1865 } 1866 1867 if (allow_deprecated == 0 && ifp_dep != NULL) { 1868 ifp = ifp_dep; 1869 allow_deprecated = 1; 1870 1871 goto again; 1872 } 1873 1874 return (copied); 1875 } 1876 1877 static bool 1878 icmp6_rip6_match(const struct inpcb *inp, void *v) 1879 { 1880 struct ip6_hdr *ip6 = v; 1881 1882 if ((inp->inp_vflag & INP_IPV6) == 0) 1883 return (false); 1884 if (inp->inp_ip_p != IPPROTO_ICMPV6) 1885 return (false); 1886 if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr) && 1887 !IN6_ARE_ADDR_EQUAL(&inp->in6p_laddr, &ip6->ip6_dst)) 1888 return (false); 1889 if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr) && 1890 !IN6_ARE_ADDR_EQUAL(&inp->in6p_faddr, &ip6->ip6_src)) 1891 return (false); 1892 return (true); 1893 } 1894 1895 /* 1896 * XXX almost dup'ed code with rip6_input. 1897 */ 1898 static int 1899 icmp6_rip6_input(struct mbuf **mp, int off) 1900 { 1901 struct mbuf *n, *m = *mp; 1902 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1903 struct inpcb_iterator inpi = INP_ITERATOR(&V_ripcbinfo, 1904 INPLOOKUP_RLOCKPCB, icmp6_rip6_match, ip6); 1905 struct inpcb *inp; 1906 struct sockaddr_in6 fromsa; 1907 struct icmp6_hdr *icmp6; 1908 struct mbuf *opts = NULL; 1909 int delivered = 0; 1910 1911 /* This is assumed to be safe; icmp6_input() does a pullup. */ 1912 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off); 1913 1914 /* 1915 * XXX: the address may have embedded scope zone ID, which should be 1916 * hidden from applications. 1917 */ 1918 bzero(&fromsa, sizeof(fromsa)); 1919 fromsa.sin6_family = AF_INET6; 1920 fromsa.sin6_len = sizeof(struct sockaddr_in6); 1921 fromsa.sin6_addr = ip6->ip6_src; 1922 if (sa6_recoverscope(&fromsa)) { 1923 m_freem(m); 1924 *mp = NULL; 1925 return (IPPROTO_DONE); 1926 } 1927 1928 while ((inp = inp_next(&inpi)) != NULL) { 1929 if (ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type, 1930 inp->in6p_icmp6filt)) 1931 continue; 1932 /* 1933 * Recent network drivers tend to allocate a single 1934 * mbuf cluster, rather than to make a couple of 1935 * mbufs without clusters. Also, since the IPv6 code 1936 * path tries to avoid m_pullup(), it is highly 1937 * probable that we still have an mbuf cluster here 1938 * even though the necessary length can be stored in an 1939 * mbuf's internal buffer. 1940 * Meanwhile, the default size of the receive socket 1941 * buffer for raw sockets is not so large. This means 1942 * the possibility of packet loss is relatively higher 1943 * than before. To avoid this scenario, we copy the 1944 * received data to a separate mbuf that does not use 1945 * a cluster, if possible. 1946 * XXX: it is better to copy the data after stripping 1947 * intermediate headers. 1948 */ 1949 if ((m->m_flags & M_EXT) && m->m_next == NULL && 1950 m->m_len <= MHLEN) { 1951 n = m_get(M_NOWAIT, m->m_type); 1952 if (n != NULL) { 1953 if (m_dup_pkthdr(n, m, M_NOWAIT)) { 1954 bcopy(m->m_data, n->m_data, m->m_len); 1955 n->m_len = m->m_len; 1956 } else { 1957 m_free(n); 1958 n = NULL; 1959 } 1960 } 1961 } else 1962 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 1963 if (n == NULL) 1964 continue; 1965 if (inp->inp_flags & INP_CONTROLOPTS) 1966 ip6_savecontrol(inp, n, &opts); 1967 /* strip intermediate headers */ 1968 m_adj(n, off); 1969 SOCKBUF_LOCK(&inp->inp_socket->so_rcv); 1970 if (sbappendaddr_locked(&inp->inp_socket->so_rcv, 1971 (struct sockaddr *)&fromsa, n, opts) == 0) { 1972 soroverflow_locked(inp->inp_socket); 1973 m_freem(n); 1974 if (opts) 1975 m_freem(opts); 1976 } else { 1977 sorwakeup_locked(inp->inp_socket); 1978 delivered++; 1979 } 1980 opts = NULL; 1981 } 1982 m_freem(m); 1983 *mp = NULL; 1984 if (delivered == 0) 1985 IP6STAT_DEC(ip6s_delivered); 1986 return (IPPROTO_DONE); 1987 } 1988 1989 /* 1990 * Reflect the ip6 packet back to the source. 1991 * OFF points to the icmp6 header, counted from the top of the mbuf. 1992 */ 1993 static void 1994 icmp6_reflect(struct mbuf *m, size_t off) 1995 { 1996 struct in6_addr src6, *srcp; 1997 struct ip6_hdr *ip6; 1998 struct icmp6_hdr *icmp6; 1999 struct in6_ifaddr *ia = NULL; 2000 struct ifnet *outif = NULL; 2001 int plen; 2002 int type, code, hlim; 2003 2004 /* too short to reflect */ 2005 if (off < sizeof(struct ip6_hdr)) { 2006 nd6log((LOG_DEBUG, 2007 "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n", 2008 (u_long)off, (u_long)sizeof(struct ip6_hdr), 2009 __FILE__, __LINE__)); 2010 goto bad; 2011 } 2012 2013 /* 2014 * If there are extra headers between IPv6 and ICMPv6, strip 2015 * off that header first. 2016 */ 2017 #ifdef DIAGNOSTIC 2018 if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN) 2019 panic("assumption failed in icmp6_reflect"); 2020 #endif 2021 if (off > sizeof(struct ip6_hdr)) { 2022 size_t l; 2023 struct ip6_hdr nip6; 2024 2025 l = off - sizeof(struct ip6_hdr); 2026 m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6); 2027 m_adj(m, l); 2028 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 2029 if (m->m_len < l) { 2030 if ((m = m_pullup(m, l)) == NULL) 2031 return; 2032 } 2033 bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6)); 2034 } else /* off == sizeof(struct ip6_hdr) */ { 2035 size_t l; 2036 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 2037 if (m->m_len < l) { 2038 if ((m = m_pullup(m, l)) == NULL) 2039 return; 2040 } 2041 } 2042 plen = m->m_pkthdr.len - sizeof(struct ip6_hdr); 2043 ip6 = mtod(m, struct ip6_hdr *); 2044 ip6->ip6_nxt = IPPROTO_ICMPV6; 2045 icmp6 = (struct icmp6_hdr *)(ip6 + 1); 2046 type = icmp6->icmp6_type; /* keep type for statistics */ 2047 code = icmp6->icmp6_code; /* ditto. */ 2048 hlim = 0; 2049 srcp = NULL; 2050 2051 /* 2052 * If the incoming packet was addressed directly to us (i.e. unicast), 2053 * use dst as the src for the reply. 2054 * The IN6_IFF_NOTREADY case should be VERY rare, but is possible 2055 * (for example) when we encounter an error while forwarding procedure 2056 * destined to a duplicated address of ours. 2057 */ 2058 if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 2059 ia = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */, false); 2060 if (ia != NULL && !(ia->ia6_flags & 2061 (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) { 2062 src6 = ia->ia_addr.sin6_addr; 2063 srcp = &src6; 2064 2065 if (m->m_pkthdr.rcvif != NULL) { 2066 /* XXX: This may not be the outgoing interface */ 2067 hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim; 2068 } else 2069 hlim = V_ip6_defhlim; 2070 } 2071 } 2072 2073 if (srcp == NULL) { 2074 int error; 2075 struct in6_addr dst6; 2076 uint32_t scopeid; 2077 2078 /* 2079 * This case matches to multicasts, our anycast, or unicasts 2080 * that we do not own. Select a source address based on the 2081 * source address of the erroneous packet. 2082 */ 2083 in6_splitscope(&ip6->ip6_src, &dst6, &scopeid); 2084 error = in6_selectsrc_addr(M_GETFIB(m), &dst6, 2085 scopeid, NULL, &src6, &hlim); 2086 2087 if (error) { 2088 char ip6buf[INET6_ADDRSTRLEN]; 2089 nd6log((LOG_DEBUG, 2090 "icmp6_reflect: source can't be determined: " 2091 "dst=%s, error=%d\n", 2092 ip6_sprintf(ip6buf, &ip6->ip6_dst), error)); 2093 goto bad; 2094 } 2095 srcp = &src6; 2096 } 2097 /* 2098 * ip6_input() drops a packet if its src is multicast. 2099 * So, the src is never multicast. 2100 */ 2101 ip6->ip6_dst = ip6->ip6_src; 2102 ip6->ip6_src = *srcp; 2103 ip6->ip6_flow = 0; 2104 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2105 ip6->ip6_vfc |= IPV6_VERSION; 2106 ip6->ip6_nxt = IPPROTO_ICMPV6; 2107 ip6->ip6_hlim = hlim; 2108 2109 icmp6->icmp6_cksum = 0; 2110 icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2111 sizeof(struct ip6_hdr), plen); 2112 2113 /* 2114 * XXX option handling 2115 */ 2116 2117 m->m_flags &= ~(M_BCAST|M_MCAST); 2118 m->m_pkthdr.rcvif = NULL; 2119 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2120 if (outif) 2121 icmp6_ifoutstat_inc(outif, type, code); 2122 2123 return; 2124 2125 bad: 2126 m_freem(m); 2127 return; 2128 } 2129 2130 static const char * 2131 icmp6_redirect_diag(struct in6_addr *src6, struct in6_addr *dst6, 2132 struct in6_addr *tgt6) 2133 { 2134 static char buf[1024]; 2135 char ip6bufs[INET6_ADDRSTRLEN]; 2136 char ip6bufd[INET6_ADDRSTRLEN]; 2137 char ip6buft[INET6_ADDRSTRLEN]; 2138 snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)", 2139 ip6_sprintf(ip6bufs, src6), ip6_sprintf(ip6bufd, dst6), 2140 ip6_sprintf(ip6buft, tgt6)); 2141 return buf; 2142 } 2143 2144 void 2145 icmp6_redirect_input(struct mbuf *m, int off) 2146 { 2147 struct ifnet *ifp; 2148 struct ip6_hdr *ip6; 2149 struct nd_redirect *nd_rd; 2150 struct in6_addr src6, redtgt6, reddst6; 2151 union nd_opts ndopts; 2152 char ip6buf[INET6_ADDRSTRLEN]; 2153 char *lladdr; 2154 int icmp6len, is_onlink, is_router, lladdrlen; 2155 2156 M_ASSERTPKTHDR(m); 2157 KASSERT(m->m_pkthdr.rcvif != NULL, ("%s: no rcvif", __func__)); 2158 2159 /* XXX if we are router, we don't update route by icmp6 redirect */ 2160 if (V_ip6_forwarding) 2161 goto freeit; 2162 if (!V_icmp6_rediraccept) 2163 goto freeit; 2164 2165 /* RFC 6980: Nodes MUST silently ignore fragments */ 2166 if(m->m_flags & M_FRAGMENTED) 2167 goto freeit; 2168 2169 ip6 = mtod(m, struct ip6_hdr *); 2170 icmp6len = ntohs(ip6->ip6_plen); 2171 if (m->m_len < off + icmp6len) { 2172 m = m_pullup(m, off + icmp6len); 2173 if (m == NULL) { 2174 IP6STAT_INC(ip6s_exthdrtoolong); 2175 return; 2176 } 2177 } 2178 ip6 = mtod(m, struct ip6_hdr *); 2179 nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off); 2180 2181 ifp = m->m_pkthdr.rcvif; 2182 redtgt6 = nd_rd->nd_rd_target; 2183 reddst6 = nd_rd->nd_rd_dst; 2184 2185 if (in6_setscope(&redtgt6, ifp, NULL) || 2186 in6_setscope(&reddst6, ifp, NULL)) { 2187 goto freeit; 2188 } 2189 2190 /* validation */ 2191 src6 = ip6->ip6_src; 2192 if (!IN6_IS_ADDR_LINKLOCAL(&src6)) { 2193 nd6log((LOG_ERR, 2194 "ICMP6 redirect sent from %s rejected; " 2195 "must be from linklocal\n", 2196 ip6_sprintf(ip6buf, &src6))); 2197 goto bad; 2198 } 2199 if (__predict_false(ip6->ip6_hlim != 255)) { 2200 ICMP6STAT_INC(icp6s_invlhlim); 2201 nd6log((LOG_ERR, 2202 "ICMP6 redirect sent from %s rejected; " 2203 "hlim=%d (must be 255)\n", 2204 ip6_sprintf(ip6buf, &src6), ip6->ip6_hlim)); 2205 goto bad; 2206 } 2207 { 2208 /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */ 2209 struct nhop_object *nh; 2210 struct in6_addr kdst; 2211 uint32_t scopeid; 2212 2213 in6_splitscope(&reddst6, &kdst, &scopeid); 2214 NET_EPOCH_ASSERT(); 2215 nh = fib6_lookup(ifp->if_fib, &kdst, scopeid, 0, 0); 2216 if (nh != NULL) { 2217 struct in6_addr nh_addr; 2218 nh_addr = ifatoia6(nh->nh_ifa)->ia_addr.sin6_addr; 2219 if ((nh->nh_flags & NHF_GATEWAY) == 0) { 2220 nd6log((LOG_ERR, 2221 "ICMP6 redirect rejected; no route " 2222 "with inet6 gateway found for redirect dst: %s\n", 2223 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2224 goto bad; 2225 } 2226 2227 /* 2228 * Embed scope zone id into next hop address. 2229 */ 2230 nh_addr = nh->gw6_sa.sin6_addr; 2231 2232 if (IN6_ARE_ADDR_EQUAL(&src6, &nh_addr) == 0) { 2233 nd6log((LOG_ERR, 2234 "ICMP6 redirect rejected; " 2235 "not equal to gw-for-src=%s (must be same): " 2236 "%s\n", 2237 ip6_sprintf(ip6buf, &nh_addr), 2238 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2239 goto bad; 2240 } 2241 } else { 2242 nd6log((LOG_ERR, 2243 "ICMP6 redirect rejected; " 2244 "no route found for redirect dst: %s\n", 2245 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2246 goto bad; 2247 } 2248 } 2249 if (IN6_IS_ADDR_MULTICAST(&reddst6)) { 2250 nd6log((LOG_ERR, 2251 "ICMP6 redirect rejected; " 2252 "redirect dst must be unicast: %s\n", 2253 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2254 goto bad; 2255 } 2256 2257 is_router = is_onlink = 0; 2258 if (IN6_IS_ADDR_LINKLOCAL(&redtgt6)) 2259 is_router = 1; /* router case */ 2260 if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0) 2261 is_onlink = 1; /* on-link destination case */ 2262 if (!is_router && !is_onlink) { 2263 nd6log((LOG_ERR, 2264 "ICMP6 redirect rejected; " 2265 "neither router case nor onlink case: %s\n", 2266 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2267 goto bad; 2268 } 2269 2270 icmp6len -= sizeof(*nd_rd); 2271 nd6_option_init(nd_rd + 1, icmp6len, &ndopts); 2272 if (nd6_options(&ndopts) < 0) { 2273 nd6log((LOG_INFO, "%s: invalid ND option, rejected: %s\n", 2274 __func__, icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2275 /* nd6_options have incremented stats */ 2276 goto freeit; 2277 } 2278 2279 lladdr = NULL; 2280 lladdrlen = 0; 2281 if (ndopts.nd_opts_tgt_lladdr) { 2282 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 2283 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 2284 } 2285 2286 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 2287 nd6log((LOG_INFO, "%s: lladdrlen mismatch for %s " 2288 "(if %d, icmp6 packet %d): %s\n", 2289 __func__, ip6_sprintf(ip6buf, &redtgt6), 2290 ifp->if_addrlen, lladdrlen - 2, 2291 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2292 goto bad; 2293 } 2294 2295 /* Validation passed. */ 2296 2297 /* RFC 2461 8.3 */ 2298 nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT, 2299 is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER); 2300 2301 /* 2302 * Install a gateway route in the better-router case or an interface 2303 * route in the on-link-destination case. 2304 */ 2305 { 2306 struct sockaddr_in6 sdst; 2307 struct sockaddr_in6 sgw; 2308 struct sockaddr_in6 ssrc; 2309 struct sockaddr *gw; 2310 int rt_flags; 2311 u_int fibnum; 2312 2313 bzero(&sdst, sizeof(sdst)); 2314 bzero(&ssrc, sizeof(ssrc)); 2315 sdst.sin6_family = ssrc.sin6_family = AF_INET6; 2316 sdst.sin6_len = ssrc.sin6_len = sizeof(struct sockaddr_in6); 2317 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr)); 2318 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr)); 2319 rt_flags = 0; 2320 if (is_router) { 2321 bzero(&sgw, sizeof(sgw)); 2322 sgw.sin6_family = AF_INET6; 2323 sgw.sin6_len = sizeof(struct sockaddr_in6); 2324 bcopy(&redtgt6, &sgw.sin6_addr, 2325 sizeof(struct in6_addr)); 2326 gw = (struct sockaddr *)&sgw; 2327 rt_flags |= RTF_GATEWAY; 2328 } else 2329 gw = ifp->if_addr->ifa_addr; 2330 for (fibnum = 0; fibnum < rt_numfibs; fibnum++) 2331 rib_add_redirect(fibnum, (struct sockaddr *)&sdst, gw, 2332 (struct sockaddr *)&ssrc, ifp, rt_flags, 2333 V_icmp6_redirtimeout); 2334 } 2335 2336 freeit: 2337 m_freem(m); 2338 return; 2339 2340 bad: 2341 ICMP6STAT_INC(icp6s_badredirect); 2342 m_freem(m); 2343 } 2344 2345 void 2346 icmp6_redirect_output(struct mbuf *m0, struct nhop_object *nh) 2347 { 2348 struct ifnet *ifp; /* my outgoing interface */ 2349 struct in6_addr *ifp_ll6; 2350 struct in6_addr *router_ll6; 2351 struct ip6_hdr *sip6; /* m0 as struct ip6_hdr */ 2352 struct mbuf *m = NULL; /* newly allocated one */ 2353 struct m_tag *mtag; 2354 struct ip6_hdr *ip6; /* m as struct ip6_hdr */ 2355 struct nd_redirect *nd_rd; 2356 struct llentry *ln = NULL; 2357 size_t maxlen; 2358 u_char *p; 2359 struct ifnet *outif = NULL; 2360 struct sockaddr_in6 src_sa; 2361 2362 icmp6_errcount(ND_REDIRECT, 0); 2363 2364 /* if we are not router, we don't send icmp6 redirect */ 2365 if (!V_ip6_forwarding) 2366 goto fail; 2367 2368 /* sanity check */ 2369 if (!m0 || !nh || !(NH_IS_VALID(nh)) || !(ifp = nh->nh_ifp)) 2370 goto fail; 2371 2372 /* 2373 * Address check: 2374 * the source address must identify a neighbor, and 2375 * the destination address must not be a multicast address 2376 * [RFC 2461, sec 8.2] 2377 */ 2378 sip6 = mtod(m0, struct ip6_hdr *); 2379 bzero(&src_sa, sizeof(src_sa)); 2380 src_sa.sin6_family = AF_INET6; 2381 src_sa.sin6_len = sizeof(src_sa); 2382 src_sa.sin6_addr = sip6->ip6_src; 2383 if (nd6_is_addr_neighbor(&src_sa, ifp) == 0) 2384 goto fail; 2385 if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst)) 2386 goto fail; /* what should we do here? */ 2387 2388 /* rate limit */ 2389 if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0)) 2390 goto fail; 2391 2392 /* 2393 * Since we are going to append up to 1280 bytes (= IPV6_MMTU), 2394 * we almost always ask for an mbuf cluster for simplicity. 2395 * (MHLEN < IPV6_MMTU is almost always true) 2396 */ 2397 #if IPV6_MMTU >= MCLBYTES 2398 # error assumption failed about IPV6_MMTU and MCLBYTES 2399 #endif 2400 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 2401 if (m == NULL) 2402 goto fail; 2403 M_SETFIB(m, M_GETFIB(m0)); 2404 maxlen = M_TRAILINGSPACE(m); 2405 maxlen = min(IPV6_MMTU, maxlen); 2406 /* just for safety */ 2407 if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) + 2408 ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) { 2409 goto fail; 2410 } 2411 2412 { 2413 /* get ip6 linklocal address for ifp(my outgoing interface). */ 2414 struct in6_ifaddr *ia; 2415 if ((ia = in6ifa_ifpforlinklocal(ifp, 2416 IN6_IFF_NOTREADY| 2417 IN6_IFF_ANYCAST)) == NULL) 2418 goto fail; 2419 ifp_ll6 = &ia->ia_addr.sin6_addr; 2420 /* XXXRW: reference released prematurely. */ 2421 ifa_free(&ia->ia_ifa); 2422 } 2423 2424 /* get ip6 linklocal address for the router. */ 2425 if (nh->nh_flags & NHF_GATEWAY) { 2426 struct sockaddr_in6 *sin6; 2427 sin6 = &nh->gw6_sa; 2428 router_ll6 = &sin6->sin6_addr; 2429 if (!IN6_IS_ADDR_LINKLOCAL(router_ll6)) 2430 router_ll6 = (struct in6_addr *)NULL; 2431 } else 2432 router_ll6 = (struct in6_addr *)NULL; 2433 2434 /* ip6 */ 2435 ip6 = mtod(m, struct ip6_hdr *); 2436 ip6->ip6_flow = 0; 2437 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2438 ip6->ip6_vfc |= IPV6_VERSION; 2439 /* ip6->ip6_plen will be set later */ 2440 ip6->ip6_nxt = IPPROTO_ICMPV6; 2441 ip6->ip6_hlim = 255; 2442 /* ip6->ip6_src must be linklocal addr for my outgoing if. */ 2443 bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr)); 2444 bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr)); 2445 2446 /* ND Redirect */ 2447 nd_rd = (struct nd_redirect *)(ip6 + 1); 2448 nd_rd->nd_rd_type = ND_REDIRECT; 2449 nd_rd->nd_rd_code = 0; 2450 nd_rd->nd_rd_reserved = 0; 2451 if (nh->nh_flags & NHF_GATEWAY) { 2452 /* 2453 * nd_rd->nd_rd_target must be a link-local address in 2454 * better router cases. 2455 */ 2456 if (!router_ll6) 2457 goto fail; 2458 bcopy(router_ll6, &nd_rd->nd_rd_target, 2459 sizeof(nd_rd->nd_rd_target)); 2460 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2461 sizeof(nd_rd->nd_rd_dst)); 2462 } else { 2463 /* make sure redtgt == reddst */ 2464 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target, 2465 sizeof(nd_rd->nd_rd_target)); 2466 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2467 sizeof(nd_rd->nd_rd_dst)); 2468 } 2469 2470 p = (u_char *)(nd_rd + 1); 2471 2472 if (!router_ll6) 2473 goto nolladdropt; 2474 2475 { 2476 /* target lladdr option */ 2477 int len; 2478 struct nd_opt_hdr *nd_opt; 2479 char *lladdr; 2480 2481 ln = nd6_lookup(router_ll6, LLE_SF(AF_INET6, 0), ifp); 2482 if (ln == NULL) 2483 goto nolladdropt; 2484 2485 len = sizeof(*nd_opt) + ifp->if_addrlen; 2486 len = (len + 7) & ~7; /* round by 8 */ 2487 /* safety check */ 2488 if (len + (p - (u_char *)ip6) > maxlen) 2489 goto nolladdropt; 2490 2491 if (ln->la_flags & LLE_VALID) { 2492 nd_opt = (struct nd_opt_hdr *)p; 2493 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 2494 nd_opt->nd_opt_len = len >> 3; 2495 lladdr = (char *)(nd_opt + 1); 2496 bcopy(ln->ll_addr, lladdr, ifp->if_addrlen); 2497 p += len; 2498 } 2499 } 2500 nolladdropt: 2501 if (ln != NULL) 2502 LLE_RUNLOCK(ln); 2503 2504 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2505 2506 /* just to be safe */ 2507 #ifdef M_DECRYPTED /*not openbsd*/ 2508 if (m0->m_flags & M_DECRYPTED) 2509 goto noredhdropt; 2510 #endif 2511 if (p - (u_char *)ip6 > maxlen) 2512 goto noredhdropt; 2513 2514 { 2515 /* redirected header option */ 2516 int len; 2517 struct nd_opt_rd_hdr *nd_opt_rh; 2518 2519 /* 2520 * compute the maximum size for icmp6 redirect header option. 2521 * XXX room for auth header? 2522 */ 2523 len = maxlen - (p - (u_char *)ip6); 2524 len &= ~7; 2525 2526 /* This is just for simplicity. */ 2527 if (m0->m_pkthdr.len != m0->m_len) { 2528 if (m0->m_next) { 2529 m_freem(m0->m_next); 2530 m0->m_next = NULL; 2531 } 2532 m0->m_pkthdr.len = m0->m_len; 2533 } 2534 2535 /* 2536 * Redirected header option spec (RFC2461 4.6.3) talks nothing 2537 * about padding/truncate rule for the original IP packet. 2538 * From the discussion on IPv6imp in Feb 1999, 2539 * the consensus was: 2540 * - "attach as much as possible" is the goal 2541 * - pad if not aligned (original size can be guessed by 2542 * original ip6 header) 2543 * Following code adds the padding if it is simple enough, 2544 * and truncates if not. 2545 */ 2546 if (m0->m_next || m0->m_pkthdr.len != m0->m_len) 2547 panic("assumption failed in %s:%d", __FILE__, 2548 __LINE__); 2549 2550 if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) { 2551 /* not enough room, truncate */ 2552 m0->m_pkthdr.len = m0->m_len = len - 2553 sizeof(*nd_opt_rh); 2554 } else { 2555 /* enough room, pad or truncate */ 2556 size_t extra; 2557 2558 extra = m0->m_pkthdr.len % 8; 2559 if (extra) { 2560 /* pad if easy enough, truncate if not */ 2561 if (8 - extra <= M_TRAILINGSPACE(m0)) { 2562 /* pad */ 2563 m0->m_len += (8 - extra); 2564 m0->m_pkthdr.len += (8 - extra); 2565 } else { 2566 /* truncate */ 2567 m0->m_pkthdr.len -= extra; 2568 m0->m_len -= extra; 2569 } 2570 } 2571 len = m0->m_pkthdr.len + sizeof(*nd_opt_rh); 2572 m0->m_pkthdr.len = m0->m_len = len - 2573 sizeof(*nd_opt_rh); 2574 } 2575 2576 nd_opt_rh = (struct nd_opt_rd_hdr *)p; 2577 bzero(nd_opt_rh, sizeof(*nd_opt_rh)); 2578 nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER; 2579 nd_opt_rh->nd_opt_rh_len = len >> 3; 2580 p += sizeof(*nd_opt_rh); 2581 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2582 2583 /* connect m0 to m */ 2584 m_tag_delete_chain(m0, NULL); 2585 m0->m_flags &= ~M_PKTHDR; 2586 m->m_next = m0; 2587 m->m_pkthdr.len = m->m_len + m0->m_len; 2588 m0 = NULL; 2589 } 2590 noredhdropt:; 2591 if (m0) { 2592 m_freem(m0); 2593 m0 = NULL; 2594 } 2595 2596 /* XXX: clear embedded link IDs in the inner header */ 2597 in6_clearscope(&sip6->ip6_src); 2598 in6_clearscope(&sip6->ip6_dst); 2599 in6_clearscope(&nd_rd->nd_rd_target); 2600 in6_clearscope(&nd_rd->nd_rd_dst); 2601 2602 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr)); 2603 2604 nd_rd->nd_rd_cksum = 0; 2605 nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2606 sizeof(*ip6), ntohs(ip6->ip6_plen)); 2607 2608 if (send_sendso_input_hook != NULL) { 2609 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, sizeof(unsigned short), 2610 M_NOWAIT); 2611 if (mtag == NULL) 2612 goto fail; 2613 *(unsigned short *)(mtag + 1) = nd_rd->nd_rd_type; 2614 m_tag_prepend(m, mtag); 2615 } 2616 2617 /* send the packet to outside... */ 2618 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2619 if (outif) { 2620 icmp6_ifstat_inc(outif, ifs6_out_msg); 2621 icmp6_ifstat_inc(outif, ifs6_out_redirect); 2622 } 2623 ICMP6STAT_INC(icp6s_outhist[ND_REDIRECT]); 2624 2625 return; 2626 2627 fail: 2628 if (m) 2629 m_freem(m); 2630 if (m0) 2631 m_freem(m0); 2632 } 2633 2634 /* 2635 * ICMPv6 socket option processing. 2636 */ 2637 int 2638 icmp6_ctloutput(struct socket *so, struct sockopt *sopt) 2639 { 2640 int error = 0; 2641 int optlen; 2642 struct inpcb *inp = sotoinpcb(so); 2643 int level, op, optname; 2644 2645 if (sopt) { 2646 level = sopt->sopt_level; 2647 op = sopt->sopt_dir; 2648 optname = sopt->sopt_name; 2649 optlen = sopt->sopt_valsize; 2650 } else 2651 level = op = optname = optlen = 0; 2652 2653 if (level != IPPROTO_ICMPV6) { 2654 return EINVAL; 2655 } 2656 2657 switch (op) { 2658 case PRCO_SETOPT: 2659 switch (optname) { 2660 case ICMP6_FILTER: 2661 { 2662 struct icmp6_filter ic6f; 2663 2664 if (optlen != sizeof(ic6f)) { 2665 error = EMSGSIZE; 2666 break; 2667 } 2668 error = sooptcopyin(sopt, &ic6f, optlen, optlen); 2669 if (error == 0) { 2670 INP_WLOCK(inp); 2671 *inp->in6p_icmp6filt = ic6f; 2672 INP_WUNLOCK(inp); 2673 } 2674 break; 2675 } 2676 2677 default: 2678 error = ENOPROTOOPT; 2679 break; 2680 } 2681 break; 2682 2683 case PRCO_GETOPT: 2684 switch (optname) { 2685 case ICMP6_FILTER: 2686 { 2687 struct icmp6_filter ic6f; 2688 2689 INP_RLOCK(inp); 2690 ic6f = *inp->in6p_icmp6filt; 2691 INP_RUNLOCK(inp); 2692 error = sooptcopyout(sopt, &ic6f, sizeof(ic6f)); 2693 break; 2694 } 2695 2696 default: 2697 error = ENOPROTOOPT; 2698 break; 2699 } 2700 break; 2701 } 2702 2703 return (error); 2704 } 2705 2706 /* 2707 * Perform rate limit check. 2708 * Returns 0 if it is okay to send the icmp6 packet. 2709 * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate 2710 * limitation. 2711 * 2712 * XXX per-destination/type check necessary? 2713 * 2714 * dst - not used at this moment 2715 * type - not used at this moment 2716 * code - not used at this moment 2717 */ 2718 static int 2719 icmp6_ratelimit(const struct in6_addr *dst, const int type, 2720 const int code) 2721 { 2722 int ret; 2723 2724 ret = 0; /* okay to send */ 2725 2726 /* PPS limit */ 2727 if (!ppsratecheck(&V_icmp6errppslim_last, &V_icmp6errpps_count, 2728 V_icmp6errppslim)) { 2729 /* The packet is subject to rate limit */ 2730 ret++; 2731 } 2732 2733 return ret; 2734 } 2735