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/nhop.h> 97 #include <net/vnet.h> 98 99 #include <netinet/in.h> 100 #include <netinet/in_pcb.h> 101 #include <netinet/in_var.h> 102 #include <netinet/ip6.h> 103 #include <netinet/icmp6.h> 104 #include <netinet/tcp_var.h> 105 106 #include <netinet6/in6_fib.h> 107 #include <netinet6/in6_ifattach.h> 108 #include <netinet6/in6_pcb.h> 109 #include <netinet6/ip6protosw.h> 110 #include <netinet6/ip6_var.h> 111 #include <netinet6/scope6_var.h> 112 #include <netinet6/mld6_var.h> 113 #include <netinet6/nd6.h> 114 #include <netinet6/send.h> 115 116 extern struct domain inet6domain; 117 118 VNET_PCPUSTAT_DEFINE(struct icmp6stat, icmp6stat); 119 VNET_PCPUSTAT_SYSINIT(icmp6stat); 120 121 #ifdef VIMAGE 122 VNET_PCPUSTAT_SYSUNINIT(icmp6stat); 123 #endif /* VIMAGE */ 124 125 VNET_DECLARE(struct inpcbinfo, ripcbinfo); 126 VNET_DECLARE(struct inpcbhead, ripcb); 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_ripcb VNET(ripcb) 134 #define V_icmp6errppslim VNET(icmp6errppslim) 135 #define V_icmp6errpps_count VNET(icmp6errpps_count) 136 #define V_icmp6errppslim_last VNET(icmp6errppslim_last) 137 #define V_icmp6_nodeinfo VNET(icmp6_nodeinfo) 138 139 static void icmp6_errcount(int, int); 140 static int icmp6_rip6_input(struct mbuf **, int); 141 static void icmp6_reflect(struct mbuf *, size_t); 142 static int icmp6_ratelimit(const struct in6_addr *, const int, const int); 143 static const char *icmp6_redirect_diag(struct in6_addr *, 144 struct in6_addr *, struct in6_addr *); 145 static struct mbuf *ni6_input(struct mbuf *, int, struct prison *); 146 static struct mbuf *ni6_nametodns(const char *, int, int); 147 static int ni6_dnsmatch(const char *, int, const char *, int); 148 static int ni6_addrs(struct icmp6_nodeinfo *, struct mbuf *, 149 struct ifnet **, struct in6_addr *); 150 static int ni6_store_addrs(struct icmp6_nodeinfo *, struct icmp6_nodeinfo *, 151 struct ifnet *, int); 152 static int icmp6_notify_error(struct mbuf **, int, int, int); 153 154 /* 155 * Kernel module interface for updating icmp6stat. The argument is an index 156 * into icmp6stat treated as an array of u_quad_t. While this encodes the 157 * general layout of icmp6stat into the caller, it doesn't encode its 158 * location, so that future changes to add, for example, per-CPU stats 159 * support won't cause binary compatibility problems for kernel modules. 160 */ 161 void 162 kmod_icmp6stat_inc(int statnum) 163 { 164 165 counter_u64_add(VNET(icmp6stat)[statnum], 1); 166 } 167 168 static void 169 icmp6_errcount(int type, int code) 170 { 171 switch (type) { 172 case ICMP6_DST_UNREACH: 173 switch (code) { 174 case ICMP6_DST_UNREACH_NOROUTE: 175 ICMP6STAT_INC(icp6s_odst_unreach_noroute); 176 return; 177 case ICMP6_DST_UNREACH_ADMIN: 178 ICMP6STAT_INC(icp6s_odst_unreach_admin); 179 return; 180 case ICMP6_DST_UNREACH_BEYONDSCOPE: 181 ICMP6STAT_INC(icp6s_odst_unreach_beyondscope); 182 return; 183 case ICMP6_DST_UNREACH_ADDR: 184 ICMP6STAT_INC(icp6s_odst_unreach_addr); 185 return; 186 case ICMP6_DST_UNREACH_NOPORT: 187 ICMP6STAT_INC(icp6s_odst_unreach_noport); 188 return; 189 } 190 break; 191 case ICMP6_PACKET_TOO_BIG: 192 ICMP6STAT_INC(icp6s_opacket_too_big); 193 return; 194 case ICMP6_TIME_EXCEEDED: 195 switch (code) { 196 case ICMP6_TIME_EXCEED_TRANSIT: 197 ICMP6STAT_INC(icp6s_otime_exceed_transit); 198 return; 199 case ICMP6_TIME_EXCEED_REASSEMBLY: 200 ICMP6STAT_INC(icp6s_otime_exceed_reassembly); 201 return; 202 } 203 break; 204 case ICMP6_PARAM_PROB: 205 switch (code) { 206 case ICMP6_PARAMPROB_HEADER: 207 ICMP6STAT_INC(icp6s_oparamprob_header); 208 return; 209 case ICMP6_PARAMPROB_NEXTHEADER: 210 ICMP6STAT_INC(icp6s_oparamprob_nextheader); 211 return; 212 case ICMP6_PARAMPROB_OPTION: 213 ICMP6STAT_INC(icp6s_oparamprob_option); 214 return; 215 } 216 break; 217 case ND_REDIRECT: 218 ICMP6STAT_INC(icp6s_oredirect); 219 return; 220 } 221 ICMP6STAT_INC(icp6s_ounknown); 222 } 223 224 /* 225 * A wrapper function for icmp6_error() necessary when the erroneous packet 226 * may not contain enough scope zone information. 227 */ 228 void 229 icmp6_error2(struct mbuf *m, int type, int code, int param, 230 struct ifnet *ifp) 231 { 232 struct ip6_hdr *ip6; 233 234 if (ifp == NULL) 235 return; 236 237 if (m->m_len < sizeof(struct ip6_hdr)) { 238 m = m_pullup(m, sizeof(struct ip6_hdr)); 239 if (m == NULL) { 240 IP6STAT_INC(ip6s_exthdrtoolong); 241 return; 242 } 243 } 244 ip6 = mtod(m, struct ip6_hdr *); 245 246 if (in6_setscope(&ip6->ip6_src, ifp, NULL) != 0) 247 return; 248 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0) 249 return; 250 251 icmp6_error(m, type, code, param); 252 } 253 254 /* 255 * Generate an error packet of type error in response to bad IP6 packet. 256 */ 257 void 258 icmp6_error(struct mbuf *m, int type, int code, int param) 259 { 260 struct ip6_hdr *oip6, *nip6; 261 struct icmp6_hdr *icmp6; 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 icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */ 382 383 return; 384 385 freeit: 386 /* 387 * If we can't tell whether or not we can generate ICMP6, free it. 388 */ 389 m_freem(m); 390 } 391 392 /* 393 * Process a received ICMP6 message. 394 */ 395 int 396 icmp6_input(struct mbuf **mp, int *offp, int proto) 397 { 398 struct mbuf *m, *n; 399 struct ifnet *ifp; 400 struct ip6_hdr *ip6, *nip6; 401 struct icmp6_hdr *icmp6, *nicmp6; 402 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 403 int code, error, icmp6len, ip6len, noff, off, sum; 404 405 m = *mp; 406 off = *offp; 407 408 if (m->m_len < off + sizeof(struct icmp6_hdr)) { 409 m = m_pullup(m, off + sizeof(struct icmp6_hdr)); 410 if (m == NULL) { 411 IP6STAT_INC(ip6s_exthdrtoolong); 412 *mp = m; 413 return (IPPROTO_DONE); 414 } 415 } 416 417 /* 418 * Locate icmp6 structure in mbuf, and check 419 * that not corrupted and of at least minimum length 420 */ 421 422 icmp6len = m->m_pkthdr.len - off; 423 if (icmp6len < sizeof(struct icmp6_hdr)) { 424 ICMP6STAT_INC(icp6s_tooshort); 425 goto freeit; 426 } 427 428 ip6 = mtod(m, struct ip6_hdr *); 429 ifp = m->m_pkthdr.rcvif; 430 /* 431 * Check multicast group membership. 432 * Note: SSM filters are not applied for ICMPv6 traffic. 433 */ 434 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 435 struct in6_multi *inm; 436 437 inm = in6m_lookup(ifp, &ip6->ip6_dst); 438 if (inm == NULL) { 439 IP6STAT_INC(ip6s_notmember); 440 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 441 goto freeit; 442 } 443 } 444 445 /* Calculate the checksum. */ 446 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off); 447 code = icmp6->icmp6_code; 448 if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) { 449 nd6log((LOG_ERR, 450 "ICMP6 checksum error(%d|%x) %s\n", 451 icmp6->icmp6_type, sum, 452 ip6_sprintf(ip6bufs, &ip6->ip6_src))); 453 ICMP6STAT_INC(icp6s_checksum); 454 goto freeit; 455 } 456 457 ICMP6STAT_INC(icp6s_inhist[icmp6->icmp6_type]); 458 icmp6_ifstat_inc(ifp, ifs6_in_msg); 459 if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK) 460 icmp6_ifstat_inc(ifp, ifs6_in_error); 461 462 ip6len = sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen); 463 switch (icmp6->icmp6_type) { 464 case ICMP6_DST_UNREACH: 465 icmp6_ifstat_inc(ifp, ifs6_in_dstunreach); 466 switch (code) { 467 case ICMP6_DST_UNREACH_NOROUTE: 468 case ICMP6_DST_UNREACH_ADDR: /* PRC_HOSTDEAD is a DOS */ 469 code = PRC_UNREACH_NET; 470 break; 471 case ICMP6_DST_UNREACH_ADMIN: 472 icmp6_ifstat_inc(ifp, ifs6_in_adminprohib); 473 code = PRC_UNREACH_ADMIN_PROHIB; 474 break; 475 case ICMP6_DST_UNREACH_BEYONDSCOPE: 476 /* I mean "source address was incorrect." */ 477 code = PRC_PARAMPROB; 478 break; 479 case ICMP6_DST_UNREACH_NOPORT: 480 code = PRC_UNREACH_PORT; 481 break; 482 default: 483 goto badcode; 484 } 485 goto deliver; 486 break; 487 488 case ICMP6_PACKET_TOO_BIG: 489 icmp6_ifstat_inc(ifp, ifs6_in_pkttoobig); 490 491 /* validation is made in icmp6_mtudisc_update */ 492 493 code = PRC_MSGSIZE; 494 495 /* 496 * Updating the path MTU will be done after examining 497 * intermediate extension headers. 498 */ 499 goto deliver; 500 break; 501 502 case ICMP6_TIME_EXCEEDED: 503 icmp6_ifstat_inc(ifp, ifs6_in_timeexceed); 504 switch (code) { 505 case ICMP6_TIME_EXCEED_TRANSIT: 506 code = PRC_TIMXCEED_INTRANS; 507 break; 508 case ICMP6_TIME_EXCEED_REASSEMBLY: 509 code = PRC_TIMXCEED_REASS; 510 break; 511 default: 512 goto badcode; 513 } 514 goto deliver; 515 break; 516 517 case ICMP6_PARAM_PROB: 518 icmp6_ifstat_inc(ifp, ifs6_in_paramprob); 519 switch (code) { 520 case ICMP6_PARAMPROB_NEXTHEADER: 521 code = PRC_UNREACH_PROTOCOL; 522 break; 523 case ICMP6_PARAMPROB_HEADER: 524 case ICMP6_PARAMPROB_OPTION: 525 code = PRC_PARAMPROB; 526 break; 527 default: 528 goto badcode; 529 } 530 goto deliver; 531 break; 532 533 case ICMP6_ECHO_REQUEST: 534 icmp6_ifstat_inc(ifp, ifs6_in_echo); 535 if (code != 0) 536 goto badcode; 537 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) { 538 /* Give up remote */ 539 break; 540 } 541 if (!M_WRITABLE(n) 542 || n->m_len < off + sizeof(struct icmp6_hdr)) { 543 struct mbuf *n0 = n; 544 int n0len; 545 546 CTASSERT(sizeof(*nip6) + sizeof(*nicmp6) <= MHLEN); 547 n = m_gethdr(M_NOWAIT, n0->m_type); 548 if (n == NULL) { 549 /* Give up remote */ 550 m_freem(n0); 551 break; 552 } 553 554 m_move_pkthdr(n, n0); /* FIB copied. */ 555 n0len = n0->m_pkthdr.len; /* save for use below */ 556 /* 557 * Copy IPv6 and ICMPv6 only. 558 */ 559 nip6 = mtod(n, struct ip6_hdr *); 560 bcopy(ip6, nip6, sizeof(struct ip6_hdr)); 561 nicmp6 = (struct icmp6_hdr *)(nip6 + 1); 562 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr)); 563 noff = sizeof(struct ip6_hdr); 564 /* new mbuf contains only ipv6+icmpv6 headers */ 565 n->m_len = noff + sizeof(struct icmp6_hdr); 566 /* 567 * Adjust mbuf. ip6_plen will be adjusted in 568 * ip6_output(). 569 */ 570 m_adj(n0, off + sizeof(struct icmp6_hdr)); 571 /* recalculate complete packet size */ 572 n->m_pkthdr.len = n0len + (noff - off); 573 n->m_next = n0; 574 } else { 575 if (n->m_len < off + sizeof(*nicmp6)) { 576 n = m_pullup(n, off + sizeof(*nicmp6)); 577 if (n == NULL) { 578 IP6STAT_INC(ip6s_exthdrtoolong); 579 break; 580 } 581 } 582 nicmp6 = (struct icmp6_hdr *)(mtod(n, caddr_t) + off); 583 noff = off; 584 } 585 if (n) { 586 nicmp6->icmp6_type = ICMP6_ECHO_REPLY; 587 nicmp6->icmp6_code = 0; 588 ICMP6STAT_INC(icp6s_reflect); 589 ICMP6STAT_INC(icp6s_outhist[ICMP6_ECHO_REPLY]); 590 icmp6_reflect(n, noff); 591 } 592 break; 593 594 case ICMP6_ECHO_REPLY: 595 icmp6_ifstat_inc(ifp, ifs6_in_echoreply); 596 if (code != 0) 597 goto badcode; 598 break; 599 600 case MLD_LISTENER_QUERY: 601 case MLD_LISTENER_REPORT: 602 case MLD_LISTENER_DONE: 603 case MLDV2_LISTENER_REPORT: 604 /* 605 * Drop MLD traffic which is not link-local, has a hop limit 606 * of greater than 1 hop, or which does not have the 607 * IPv6 HBH Router Alert option. 608 * As IPv6 HBH options are stripped in ip6_input() we must 609 * check an mbuf header flag. 610 * XXX Should we also sanity check that these messages 611 * were directed to a link-local multicast prefix? 612 */ 613 if ((ip6->ip6_hlim != 1) || (m->m_flags & M_RTALERT_MLD) == 0) 614 goto freeit; 615 if (mld_input(&m, off, icmp6len) != 0) { 616 *mp = NULL; 617 return (IPPROTO_DONE); 618 } 619 /* m stays. */ 620 break; 621 622 case ICMP6_WRUREQUEST: /* ICMP6_FQDN_QUERY */ 623 { 624 enum { WRU, FQDN } mode; 625 struct prison *pr; 626 627 if (!V_icmp6_nodeinfo) 628 break; 629 630 if (icmp6len == sizeof(struct icmp6_hdr) + 4) 631 mode = WRU; 632 else if (icmp6len >= sizeof(struct icmp6_nodeinfo)) 633 mode = FQDN; 634 else 635 goto badlen; 636 637 pr = NULL; 638 sx_slock(&allprison_lock); 639 TAILQ_FOREACH(pr, &allprison, pr_list) 640 if (pr->pr_vnet == ifp->if_vnet) 641 break; 642 sx_sunlock(&allprison_lock); 643 if (pr == NULL) 644 pr = curthread->td_ucred->cr_prison; 645 if (mode == FQDN) { 646 if (m->m_len < off + sizeof(struct icmp6_nodeinfo)) { 647 m = m_pullup(m, off + 648 sizeof(struct icmp6_nodeinfo)); 649 if (m == NULL) { 650 IP6STAT_INC(ip6s_exthdrtoolong); 651 *mp = m; 652 return (IPPROTO_DONE); 653 } 654 } 655 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 656 if (n) 657 n = ni6_input(n, off, pr); 658 /* XXX meaningless if n == NULL */ 659 noff = sizeof(struct ip6_hdr); 660 } else { 661 u_char *p; 662 int maxhlen, hlen; 663 664 /* 665 * XXX: this combination of flags is pointless, 666 * but should we keep this for compatibility? 667 */ 668 if ((V_icmp6_nodeinfo & (ICMP6_NODEINFO_FQDNOK | 669 ICMP6_NODEINFO_TMPADDROK)) != 670 (ICMP6_NODEINFO_FQDNOK | ICMP6_NODEINFO_TMPADDROK)) 671 break; 672 673 if (code != 0) 674 goto badcode; 675 676 CTASSERT(sizeof(*nip6) + sizeof(*nicmp6) + 4 <= MHLEN); 677 n = m_gethdr(M_NOWAIT, m->m_type); 678 if (n == NULL) { 679 /* Give up remote */ 680 break; 681 } 682 if (!m_dup_pkthdr(n, m, M_NOWAIT)) { 683 /* 684 * Previous code did a blind M_COPY_PKTHDR 685 * and said "just for rcvif". If true, then 686 * we could tolerate the dup failing (due to 687 * the deep copy of the tag chain). For now 688 * be conservative and just fail. 689 */ 690 m_free(n); 691 n = NULL; 692 break; 693 } 694 /* 695 * Copy IPv6 and ICMPv6 only. 696 */ 697 nip6 = mtod(n, struct ip6_hdr *); 698 bcopy(ip6, nip6, sizeof(struct ip6_hdr)); 699 nicmp6 = (struct icmp6_hdr *)(nip6 + 1); 700 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr)); 701 p = (u_char *)(nicmp6 + 1); 702 bzero(p, 4); 703 704 maxhlen = M_TRAILINGSPACE(n) - 705 (sizeof(*nip6) + sizeof(*nicmp6) + 4); 706 mtx_lock(&pr->pr_mtx); 707 hlen = strlen(pr->pr_hostname); 708 if (maxhlen > hlen) 709 maxhlen = hlen; 710 /* meaningless TTL */ 711 bcopy(pr->pr_hostname, p + 4, maxhlen); 712 mtx_unlock(&pr->pr_mtx); 713 noff = sizeof(struct ip6_hdr); 714 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + 715 sizeof(struct icmp6_hdr) + 4 + maxhlen; 716 nicmp6->icmp6_type = ICMP6_WRUREPLY; 717 nicmp6->icmp6_code = 0; 718 } 719 if (n) { 720 ICMP6STAT_INC(icp6s_reflect); 721 ICMP6STAT_INC(icp6s_outhist[ICMP6_WRUREPLY]); 722 icmp6_reflect(n, noff); 723 } 724 break; 725 } 726 727 case ICMP6_WRUREPLY: 728 if (code != 0) 729 goto badcode; 730 break; 731 732 case ND_ROUTER_SOLICIT: 733 icmp6_ifstat_inc(ifp, ifs6_in_routersolicit); 734 if (code != 0) 735 goto badcode; 736 if (icmp6len < sizeof(struct nd_router_solicit)) 737 goto badlen; 738 if (send_sendso_input_hook != NULL) { 739 if (m->m_len < off + icmp6len) { 740 m = m_pullup(m, off + icmp6len); 741 if (m == NULL) { 742 IP6STAT_INC(ip6s_exthdrtoolong); 743 *mp = NULL; 744 return (IPPROTO_DONE); 745 } 746 } 747 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 748 if (error == 0) { 749 m = NULL; 750 goto freeit; 751 } 752 } 753 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 754 nd6_rs_input(m, off, icmp6len); 755 m = n; 756 if (m == NULL) 757 goto freeit; 758 break; 759 760 case ND_ROUTER_ADVERT: 761 icmp6_ifstat_inc(ifp, ifs6_in_routeradvert); 762 if (code != 0) 763 goto badcode; 764 if (icmp6len < sizeof(struct nd_router_advert)) 765 goto badlen; 766 if (send_sendso_input_hook != NULL) { 767 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 768 if (error == 0) { 769 m = NULL; 770 goto freeit; 771 } 772 } 773 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 774 nd6_ra_input(m, off, icmp6len); 775 m = n; 776 if (m == NULL) 777 goto freeit; 778 break; 779 780 case ND_NEIGHBOR_SOLICIT: 781 icmp6_ifstat_inc(ifp, ifs6_in_neighborsolicit); 782 if (code != 0) 783 goto badcode; 784 if (icmp6len < sizeof(struct nd_neighbor_solicit)) 785 goto badlen; 786 if (send_sendso_input_hook != NULL) { 787 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 788 if (error == 0) { 789 m = NULL; 790 goto freeit; 791 } 792 } 793 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 794 nd6_ns_input(m, off, icmp6len); 795 m = n; 796 if (m == NULL) 797 goto freeit; 798 break; 799 800 case ND_NEIGHBOR_ADVERT: 801 icmp6_ifstat_inc(ifp, ifs6_in_neighboradvert); 802 if (code != 0) 803 goto badcode; 804 if (icmp6len < sizeof(struct nd_neighbor_advert)) 805 goto badlen; 806 if (send_sendso_input_hook != NULL) { 807 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 808 if (error == 0) { 809 m = NULL; 810 goto freeit; 811 } 812 } 813 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 814 nd6_na_input(m, off, icmp6len); 815 m = n; 816 if (m == NULL) 817 goto freeit; 818 break; 819 820 case ND_REDIRECT: 821 icmp6_ifstat_inc(ifp, ifs6_in_redirect); 822 if (code != 0) 823 goto badcode; 824 if (icmp6len < sizeof(struct nd_redirect)) 825 goto badlen; 826 if (send_sendso_input_hook != NULL) { 827 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 828 if (error == 0) { 829 m = NULL; 830 goto freeit; 831 } 832 } 833 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 834 icmp6_redirect_input(m, off); 835 m = n; 836 if (m == NULL) 837 goto freeit; 838 break; 839 840 case ICMP6_ROUTER_RENUMBERING: 841 if (code != ICMP6_ROUTER_RENUMBERING_COMMAND && 842 code != ICMP6_ROUTER_RENUMBERING_RESULT) 843 goto badcode; 844 if (icmp6len < sizeof(struct icmp6_router_renum)) 845 goto badlen; 846 break; 847 848 default: 849 nd6log((LOG_DEBUG, 850 "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n", 851 icmp6->icmp6_type, ip6_sprintf(ip6bufs, &ip6->ip6_src), 852 ip6_sprintf(ip6bufd, &ip6->ip6_dst), 853 ifp ? ifp->if_index : 0)); 854 if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) { 855 /* ICMPv6 error: MUST deliver it by spec... */ 856 code = PRC_NCMDS; 857 /* deliver */ 858 } else { 859 /* ICMPv6 informational: MUST not deliver */ 860 break; 861 } 862 deliver: 863 if (icmp6_notify_error(&m, off, icmp6len, code) != 0) { 864 /* In this case, m should've been freed. */ 865 *mp = NULL; 866 return (IPPROTO_DONE); 867 } 868 break; 869 870 badcode: 871 ICMP6STAT_INC(icp6s_badcode); 872 break; 873 874 badlen: 875 ICMP6STAT_INC(icp6s_badlen); 876 break; 877 } 878 879 /* deliver the packet to appropriate sockets */ 880 icmp6_rip6_input(&m, *offp); 881 882 *mp = m; 883 return (IPPROTO_DONE); 884 885 freeit: 886 m_freem(m); 887 *mp = NULL; 888 return (IPPROTO_DONE); 889 } 890 891 static int 892 icmp6_notify_error(struct mbuf **mp, int off, int icmp6len, int code) 893 { 894 struct mbuf *m; 895 struct icmp6_hdr *icmp6; 896 struct ip6_hdr *eip6; 897 u_int32_t notifymtu; 898 struct sockaddr_in6 icmp6src, icmp6dst; 899 900 m = *mp; 901 902 if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) { 903 ICMP6STAT_INC(icp6s_tooshort); 904 goto freeit; 905 } 906 907 if (m->m_len < off + sizeof(*icmp6) + sizeof(struct ip6_hdr)) { 908 m = m_pullup(m, off + sizeof(*icmp6) + sizeof(struct ip6_hdr)); 909 if (m == NULL) { 910 IP6STAT_INC(ip6s_exthdrtoolong); 911 *mp = m; 912 return (-1); 913 } 914 } 915 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 916 eip6 = (struct ip6_hdr *)(icmp6 + 1); 917 918 /* Detect the upper level protocol */ 919 { 920 void (*ctlfunc)(int, struct sockaddr *, void *); 921 u_int8_t nxt = eip6->ip6_nxt; 922 int eoff = off + sizeof(struct icmp6_hdr) + 923 sizeof(struct ip6_hdr); 924 struct ip6ctlparam ip6cp; 925 struct in6_addr *finaldst = NULL; 926 int icmp6type = icmp6->icmp6_type; 927 struct ip6_frag *fh; 928 struct ip6_rthdr *rth; 929 struct ip6_rthdr0 *rth0; 930 int rthlen; 931 932 while (1) { /* XXX: should avoid infinite loop explicitly? */ 933 struct ip6_ext *eh; 934 935 switch (nxt) { 936 case IPPROTO_HOPOPTS: 937 case IPPROTO_DSTOPTS: 938 case IPPROTO_AH: 939 if (m->m_len < eoff + sizeof(struct ip6_ext)) { 940 m = m_pullup(m, eoff + 941 sizeof(struct ip6_ext)); 942 if (m == NULL) { 943 IP6STAT_INC(ip6s_exthdrtoolong); 944 *mp = m; 945 return (-1); 946 } 947 } 948 eh = (struct ip6_ext *) 949 (mtod(m, caddr_t) + eoff); 950 if (nxt == IPPROTO_AH) 951 eoff += (eh->ip6e_len + 2) << 2; 952 else 953 eoff += (eh->ip6e_len + 1) << 3; 954 nxt = eh->ip6e_nxt; 955 break; 956 case IPPROTO_ROUTING: 957 /* 958 * When the erroneous packet contains a 959 * routing header, we should examine the 960 * header to determine the final destination. 961 * Otherwise, we can't properly update 962 * information that depends on the final 963 * destination (e.g. path MTU). 964 */ 965 if (m->m_len < eoff + sizeof(*rth)) { 966 m = m_pullup(m, eoff + sizeof(*rth)); 967 if (m == NULL) { 968 IP6STAT_INC(ip6s_exthdrtoolong); 969 *mp = m; 970 return (-1); 971 } 972 } 973 rth = (struct ip6_rthdr *) 974 (mtod(m, caddr_t) + eoff); 975 rthlen = (rth->ip6r_len + 1) << 3; 976 /* 977 * XXX: currently there is no 978 * officially defined type other 979 * than type-0. 980 * Note that if the segment left field 981 * is 0, all intermediate hops must 982 * have been passed. 983 */ 984 if (rth->ip6r_segleft && 985 rth->ip6r_type == IPV6_RTHDR_TYPE_0) { 986 int hops; 987 988 if (m->m_len < eoff + rthlen) { 989 m = m_pullup(m, eoff + rthlen); 990 if (m == NULL) { 991 IP6STAT_INC( 992 ip6s_exthdrtoolong); 993 *mp = m; 994 return (-1); 995 } 996 } 997 rth0 = (struct ip6_rthdr0 *) 998 (mtod(m, caddr_t) + eoff); 999 /* just ignore a bogus header */ 1000 if ((rth0->ip6r0_len % 2) == 0 && 1001 (hops = rth0->ip6r0_len/2)) 1002 finaldst = (struct in6_addr *)(rth0 + 1) + (hops - 1); 1003 } 1004 eoff += rthlen; 1005 nxt = rth->ip6r_nxt; 1006 break; 1007 case IPPROTO_FRAGMENT: 1008 if (m->m_len < eoff + sizeof(struct ip6_frag)) { 1009 m = m_pullup(m, eoff + 1010 sizeof(struct ip6_frag)); 1011 if (m == NULL) { 1012 IP6STAT_INC(ip6s_exthdrtoolong); 1013 *mp = m; 1014 return (-1); 1015 } 1016 } 1017 fh = (struct ip6_frag *)(mtod(m, caddr_t) + 1018 eoff); 1019 /* 1020 * Data after a fragment header is meaningless 1021 * unless it is the first fragment, but 1022 * we'll go to the notify label for path MTU 1023 * discovery. 1024 */ 1025 if (fh->ip6f_offlg & IP6F_OFF_MASK) 1026 goto notify; 1027 1028 eoff += sizeof(struct ip6_frag); 1029 nxt = fh->ip6f_nxt; 1030 break; 1031 default: 1032 /* 1033 * This case includes ESP and the No Next 1034 * Header. In such cases going to the notify 1035 * label does not have any meaning 1036 * (i.e. ctlfunc will be NULL), but we go 1037 * anyway since we might have to update 1038 * path MTU information. 1039 */ 1040 goto notify; 1041 } 1042 } 1043 notify: 1044 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 1045 1046 /* 1047 * retrieve parameters from the inner IPv6 header, and convert 1048 * them into sockaddr structures. 1049 * XXX: there is no guarantee that the source or destination 1050 * addresses of the inner packet are in the same scope as 1051 * the addresses of the icmp packet. But there is no other 1052 * way to determine the zone. 1053 */ 1054 eip6 = (struct ip6_hdr *)(icmp6 + 1); 1055 1056 bzero(&icmp6dst, sizeof(icmp6dst)); 1057 icmp6dst.sin6_len = sizeof(struct sockaddr_in6); 1058 icmp6dst.sin6_family = AF_INET6; 1059 if (finaldst == NULL) 1060 icmp6dst.sin6_addr = eip6->ip6_dst; 1061 else 1062 icmp6dst.sin6_addr = *finaldst; 1063 if (in6_setscope(&icmp6dst.sin6_addr, m->m_pkthdr.rcvif, NULL)) 1064 goto freeit; 1065 bzero(&icmp6src, sizeof(icmp6src)); 1066 icmp6src.sin6_len = sizeof(struct sockaddr_in6); 1067 icmp6src.sin6_family = AF_INET6; 1068 icmp6src.sin6_addr = eip6->ip6_src; 1069 if (in6_setscope(&icmp6src.sin6_addr, m->m_pkthdr.rcvif, NULL)) 1070 goto freeit; 1071 icmp6src.sin6_flowinfo = 1072 (eip6->ip6_flow & IPV6_FLOWLABEL_MASK); 1073 1074 if (finaldst == NULL) 1075 finaldst = &eip6->ip6_dst; 1076 ip6cp.ip6c_m = m; 1077 ip6cp.ip6c_icmp6 = icmp6; 1078 ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1); 1079 ip6cp.ip6c_off = eoff; 1080 ip6cp.ip6c_finaldst = finaldst; 1081 ip6cp.ip6c_src = &icmp6src; 1082 ip6cp.ip6c_nxt = nxt; 1083 1084 if (icmp6type == ICMP6_PACKET_TOO_BIG) { 1085 notifymtu = ntohl(icmp6->icmp6_mtu); 1086 ip6cp.ip6c_cmdarg = (void *)¬ifymtu; 1087 icmp6_mtudisc_update(&ip6cp, 1); /*XXX*/ 1088 } 1089 1090 ctlfunc = (void (*)(int, struct sockaddr *, void *)) 1091 (inet6sw[ip6_protox[nxt]].pr_ctlinput); 1092 if (ctlfunc) { 1093 (void) (*ctlfunc)(code, (struct sockaddr *)&icmp6dst, 1094 &ip6cp); 1095 } 1096 } 1097 *mp = m; 1098 return (0); 1099 1100 freeit: 1101 m_freem(m); 1102 *mp = NULL; 1103 return (-1); 1104 } 1105 1106 void 1107 icmp6_mtudisc_update(struct ip6ctlparam *ip6cp, int validated) 1108 { 1109 struct in6_addr *dst = ip6cp->ip6c_finaldst; 1110 struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6; 1111 struct mbuf *m = ip6cp->ip6c_m; /* will be necessary for scope issue */ 1112 u_int mtu = ntohl(icmp6->icmp6_mtu); 1113 struct in_conninfo inc; 1114 1115 #if 0 1116 /* 1117 * RFC2460 section 5, last paragraph. 1118 * even though minimum link MTU for IPv6 is IPV6_MMTU, 1119 * we may see ICMPv6 too big with mtu < IPV6_MMTU 1120 * due to packet translator in the middle. 1121 * see ip6_output() and ip6_getpmtu() "alwaysfrag" case for 1122 * special handling. 1123 */ 1124 if (mtu < IPV6_MMTU) 1125 return; 1126 #endif 1127 1128 /* 1129 * we reject ICMPv6 too big with abnormally small value. 1130 * XXX what is the good definition of "abnormally small"? 1131 */ 1132 if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8) 1133 return; 1134 1135 if (!validated) 1136 return; 1137 1138 /* 1139 * In case the suggested mtu is less than IPV6_MMTU, we 1140 * only need to remember that it was for above mentioned 1141 * "alwaysfrag" case. 1142 * Try to be as close to the spec as possible. 1143 */ 1144 if (mtu < IPV6_MMTU) 1145 mtu = IPV6_MMTU - 8; 1146 1147 bzero(&inc, sizeof(inc)); 1148 inc.inc_fibnum = M_GETFIB(m); 1149 inc.inc_flags |= INC_ISIPV6; 1150 inc.inc6_faddr = *dst; 1151 if (in6_setscope(&inc.inc6_faddr, m->m_pkthdr.rcvif, NULL)) 1152 return; 1153 1154 if (mtu < tcp_maxmtu6(&inc, NULL)) { 1155 tcp_hc_updatemtu(&inc, mtu); 1156 ICMP6STAT_INC(icp6s_pmtuchg); 1157 } 1158 } 1159 1160 /* 1161 * Process a Node Information Query packet, based on 1162 * draft-ietf-ipngwg-icmp-name-lookups-07. 1163 * 1164 * Spec incompatibilities: 1165 * - IPv6 Subject address handling 1166 * - IPv4 Subject address handling support missing 1167 * - Proxy reply (answer even if it's not for me) 1168 * - joins NI group address at in6_ifattach() time only, does not cope 1169 * with hostname changes by sethostname(3) 1170 */ 1171 static struct mbuf * 1172 ni6_input(struct mbuf *m, int off, struct prison *pr) 1173 { 1174 struct icmp6_nodeinfo *ni6, *nni6; 1175 struct mbuf *n = NULL; 1176 u_int16_t qtype; 1177 int subjlen; 1178 int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); 1179 struct ni_reply_fqdn *fqdn; 1180 int addrs; /* for NI_QTYPE_NODEADDR */ 1181 struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */ 1182 struct in6_addr in6_subj; /* subject address */ 1183 struct ip6_hdr *ip6; 1184 int oldfqdn = 0; /* if 1, return pascal string (03 draft) */ 1185 char *subj = NULL; 1186 struct in6_ifaddr *ia6 = NULL; 1187 1188 ip6 = mtod(m, struct ip6_hdr *); 1189 ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off); 1190 1191 /* 1192 * Validate IPv6 source address. 1193 * The default configuration MUST be to refuse answering queries from 1194 * global-scope addresses according to RFC4602. 1195 * Notes: 1196 * - it's not very clear what "refuse" means; this implementation 1197 * simply drops it. 1198 * - it's not very easy to identify global-scope (unicast) addresses 1199 * since there are many prefixes for them. It should be safer 1200 * and in practice sufficient to check "all" but loopback and 1201 * link-local (note that site-local unicast was deprecated and 1202 * ULA is defined as global scope-wise) 1203 */ 1204 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_GLOBALOK) == 0 && 1205 !IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) && 1206 !IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) 1207 goto bad; 1208 1209 /* 1210 * Validate IPv6 destination address. 1211 * 1212 * The Responder must discard the Query without further processing 1213 * unless it is one of the Responder's unicast or anycast addresses, or 1214 * a link-local scope multicast address which the Responder has joined. 1215 * [RFC4602, Section 5.] 1216 */ 1217 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 1218 if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst)) 1219 goto bad; 1220 /* else it's a link-local multicast, fine */ 1221 } else { /* unicast or anycast */ 1222 ia6 = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */); 1223 if (ia6 == NULL) 1224 goto bad; /* XXX impossible */ 1225 1226 if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) && 1227 !(V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK)) { 1228 ifa_free(&ia6->ia_ifa); 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 ifa_free(&ia6->ia_ifa); 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 /* should notify about lost packet */ 1978 m_freem(n); 1979 if (opts) { 1980 m_freem(opts); 1981 } 1982 SOCKBUF_UNLOCK( 1983 &last->inp_socket->so_rcv); 1984 } else 1985 sorwakeup_locked(last->inp_socket); 1986 opts = NULL; 1987 } 1988 INP_RUNLOCK(last); 1989 } 1990 last = inp; 1991 } 1992 if (last != NULL) { 1993 if (last->inp_flags & INP_CONTROLOPTS) 1994 ip6_savecontrol(last, m, &opts); 1995 /* strip intermediate headers */ 1996 m_adj(m, off); 1997 1998 /* avoid using mbuf clusters if possible (see above) */ 1999 if ((m->m_flags & M_EXT) && m->m_next == NULL && 2000 m->m_len <= MHLEN) { 2001 struct mbuf *n; 2002 2003 n = m_get(M_NOWAIT, m->m_type); 2004 if (n != NULL) { 2005 if (m_dup_pkthdr(n, m, M_NOWAIT)) { 2006 bcopy(m->m_data, n->m_data, m->m_len); 2007 n->m_len = m->m_len; 2008 2009 m_freem(m); 2010 m = n; 2011 } else { 2012 m_freem(n); 2013 n = NULL; 2014 } 2015 } 2016 } 2017 SOCKBUF_LOCK(&last->inp_socket->so_rcv); 2018 if (sbappendaddr_locked(&last->inp_socket->so_rcv, 2019 (struct sockaddr *)&fromsa, m, opts) == 0) { 2020 m_freem(m); 2021 if (opts) 2022 m_freem(opts); 2023 SOCKBUF_UNLOCK(&last->inp_socket->so_rcv); 2024 } else 2025 sorwakeup_locked(last->inp_socket); 2026 INP_RUNLOCK(last); 2027 } else { 2028 m_freem(m); 2029 IP6STAT_DEC(ip6s_delivered); 2030 } 2031 *mp = NULL; 2032 return (IPPROTO_DONE); 2033 } 2034 2035 /* 2036 * Reflect the ip6 packet back to the source. 2037 * OFF points to the icmp6 header, counted from the top of the mbuf. 2038 */ 2039 static void 2040 icmp6_reflect(struct mbuf *m, size_t off) 2041 { 2042 struct in6_addr src6, *srcp; 2043 struct ip6_hdr *ip6; 2044 struct icmp6_hdr *icmp6; 2045 struct in6_ifaddr *ia = NULL; 2046 struct ifnet *outif = NULL; 2047 int plen; 2048 int type, code, hlim; 2049 2050 /* too short to reflect */ 2051 if (off < sizeof(struct ip6_hdr)) { 2052 nd6log((LOG_DEBUG, 2053 "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n", 2054 (u_long)off, (u_long)sizeof(struct ip6_hdr), 2055 __FILE__, __LINE__)); 2056 goto bad; 2057 } 2058 2059 /* 2060 * If there are extra headers between IPv6 and ICMPv6, strip 2061 * off that header first. 2062 */ 2063 #ifdef DIAGNOSTIC 2064 if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN) 2065 panic("assumption failed in icmp6_reflect"); 2066 #endif 2067 if (off > sizeof(struct ip6_hdr)) { 2068 size_t l; 2069 struct ip6_hdr nip6; 2070 2071 l = off - sizeof(struct ip6_hdr); 2072 m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6); 2073 m_adj(m, l); 2074 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 2075 if (m->m_len < l) { 2076 if ((m = m_pullup(m, l)) == NULL) 2077 return; 2078 } 2079 bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6)); 2080 } else /* off == sizeof(struct ip6_hdr) */ { 2081 size_t l; 2082 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 2083 if (m->m_len < l) { 2084 if ((m = m_pullup(m, l)) == NULL) 2085 return; 2086 } 2087 } 2088 plen = m->m_pkthdr.len - sizeof(struct ip6_hdr); 2089 ip6 = mtod(m, struct ip6_hdr *); 2090 ip6->ip6_nxt = IPPROTO_ICMPV6; 2091 icmp6 = (struct icmp6_hdr *)(ip6 + 1); 2092 type = icmp6->icmp6_type; /* keep type for statistics */ 2093 code = icmp6->icmp6_code; /* ditto. */ 2094 hlim = 0; 2095 srcp = NULL; 2096 2097 /* 2098 * If the incoming packet was addressed directly to us (i.e. unicast), 2099 * use dst as the src for the reply. 2100 * The IN6_IFF_NOTREADY case should be VERY rare, but is possible 2101 * (for example) when we encounter an error while forwarding procedure 2102 * destined to a duplicated address of ours. 2103 */ 2104 if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 2105 ia = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */); 2106 if (ia != NULL && !(ia->ia6_flags & 2107 (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) { 2108 src6 = ia->ia_addr.sin6_addr; 2109 srcp = &src6; 2110 2111 if (m->m_pkthdr.rcvif != NULL) { 2112 /* XXX: This may not be the outgoing interface */ 2113 hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim; 2114 } else 2115 hlim = V_ip6_defhlim; 2116 } 2117 if (ia != NULL) 2118 ifa_free(&ia->ia_ifa); 2119 } 2120 2121 if (srcp == NULL) { 2122 int error; 2123 struct in6_addr dst6; 2124 uint32_t scopeid; 2125 2126 /* 2127 * This case matches to multicasts, our anycast, or unicasts 2128 * that we do not own. Select a source address based on the 2129 * source address of the erroneous packet. 2130 */ 2131 in6_splitscope(&ip6->ip6_src, &dst6, &scopeid); 2132 error = in6_selectsrc_addr(M_GETFIB(m), &dst6, 2133 scopeid, NULL, &src6, &hlim); 2134 2135 if (error) { 2136 char ip6buf[INET6_ADDRSTRLEN]; 2137 nd6log((LOG_DEBUG, 2138 "icmp6_reflect: source can't be determined: " 2139 "dst=%s, error=%d\n", 2140 ip6_sprintf(ip6buf, &ip6->ip6_dst), error)); 2141 goto bad; 2142 } 2143 srcp = &src6; 2144 } 2145 /* 2146 * ip6_input() drops a packet if its src is multicast. 2147 * So, the src is never multicast. 2148 */ 2149 ip6->ip6_dst = ip6->ip6_src; 2150 ip6->ip6_src = *srcp; 2151 ip6->ip6_flow = 0; 2152 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2153 ip6->ip6_vfc |= IPV6_VERSION; 2154 ip6->ip6_nxt = IPPROTO_ICMPV6; 2155 ip6->ip6_hlim = hlim; 2156 2157 icmp6->icmp6_cksum = 0; 2158 icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2159 sizeof(struct ip6_hdr), plen); 2160 2161 /* 2162 * XXX option handling 2163 */ 2164 2165 m->m_flags &= ~(M_BCAST|M_MCAST); 2166 m->m_pkthdr.rcvif = NULL; 2167 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2168 if (outif) 2169 icmp6_ifoutstat_inc(outif, type, code); 2170 2171 return; 2172 2173 bad: 2174 m_freem(m); 2175 return; 2176 } 2177 2178 void 2179 icmp6_fasttimo(void) 2180 { 2181 2182 mld_fasttimo(); 2183 } 2184 2185 void 2186 icmp6_slowtimo(void) 2187 { 2188 2189 mld_slowtimo(); 2190 } 2191 2192 static const char * 2193 icmp6_redirect_diag(struct in6_addr *src6, struct in6_addr *dst6, 2194 struct in6_addr *tgt6) 2195 { 2196 static char buf[1024]; 2197 char ip6bufs[INET6_ADDRSTRLEN]; 2198 char ip6bufd[INET6_ADDRSTRLEN]; 2199 char ip6buft[INET6_ADDRSTRLEN]; 2200 snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)", 2201 ip6_sprintf(ip6bufs, src6), ip6_sprintf(ip6bufd, dst6), 2202 ip6_sprintf(ip6buft, tgt6)); 2203 return buf; 2204 } 2205 2206 void 2207 icmp6_redirect_input(struct mbuf *m, int off) 2208 { 2209 struct ifnet *ifp; 2210 struct ip6_hdr *ip6; 2211 struct nd_redirect *nd_rd; 2212 struct in6_addr src6, redtgt6, reddst6; 2213 union nd_opts ndopts; 2214 char ip6buf[INET6_ADDRSTRLEN]; 2215 char *lladdr; 2216 int icmp6len, is_onlink, is_router, lladdrlen; 2217 2218 M_ASSERTPKTHDR(m); 2219 KASSERT(m->m_pkthdr.rcvif != NULL, ("%s: no rcvif", __func__)); 2220 2221 /* XXX if we are router, we don't update route by icmp6 redirect */ 2222 if (V_ip6_forwarding) 2223 goto freeit; 2224 if (!V_icmp6_rediraccept) 2225 goto freeit; 2226 2227 /* RFC 6980: Nodes MUST silently ignore fragments */ 2228 if(m->m_flags & M_FRAGMENTED) 2229 goto freeit; 2230 2231 ip6 = mtod(m, struct ip6_hdr *); 2232 icmp6len = ntohs(ip6->ip6_plen); 2233 if (m->m_len < off + icmp6len) { 2234 m = m_pullup(m, off + icmp6len); 2235 if (m == NULL) { 2236 IP6STAT_INC(ip6s_exthdrtoolong); 2237 return; 2238 } 2239 } 2240 ip6 = mtod(m, struct ip6_hdr *); 2241 nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off); 2242 2243 ifp = m->m_pkthdr.rcvif; 2244 redtgt6 = nd_rd->nd_rd_target; 2245 reddst6 = nd_rd->nd_rd_dst; 2246 2247 if (in6_setscope(&redtgt6, ifp, NULL) || 2248 in6_setscope(&reddst6, ifp, NULL)) { 2249 goto freeit; 2250 } 2251 2252 /* validation */ 2253 src6 = ip6->ip6_src; 2254 if (!IN6_IS_ADDR_LINKLOCAL(&src6)) { 2255 nd6log((LOG_ERR, 2256 "ICMP6 redirect sent from %s rejected; " 2257 "must be from linklocal\n", 2258 ip6_sprintf(ip6buf, &src6))); 2259 goto bad; 2260 } 2261 if (ip6->ip6_hlim != 255) { 2262 nd6log((LOG_ERR, 2263 "ICMP6 redirect sent from %s rejected; " 2264 "hlim=%d (must be 255)\n", 2265 ip6_sprintf(ip6buf, &src6), ip6->ip6_hlim)); 2266 goto bad; 2267 } 2268 { 2269 /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */ 2270 struct nhop6_basic nh6; 2271 struct in6_addr kdst; 2272 uint32_t scopeid; 2273 2274 in6_splitscope(&reddst6, &kdst, &scopeid); 2275 if (fib6_lookup_nh_basic(ifp->if_fib, &kdst, scopeid, 0, 0,&nh6)==0){ 2276 if ((nh6.nh_flags & NHF_GATEWAY) == 0) { 2277 nd6log((LOG_ERR, 2278 "ICMP6 redirect rejected; no route " 2279 "with inet6 gateway found for redirect dst: %s\n", 2280 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2281 goto bad; 2282 } 2283 2284 /* 2285 * Embed scope zone id into next hop address, since 2286 * fib6_lookup_nh_basic() returns address without embedded 2287 * scope zone id. 2288 */ 2289 if (in6_setscope(&nh6.nh_addr, m->m_pkthdr.rcvif, NULL)) 2290 goto freeit; 2291 2292 if (IN6_ARE_ADDR_EQUAL(&src6, &nh6.nh_addr) == 0) { 2293 nd6log((LOG_ERR, 2294 "ICMP6 redirect rejected; " 2295 "not equal to gw-for-src=%s (must be same): " 2296 "%s\n", 2297 ip6_sprintf(ip6buf, &nh6.nh_addr), 2298 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2299 goto bad; 2300 } 2301 } else { 2302 nd6log((LOG_ERR, 2303 "ICMP6 redirect rejected; " 2304 "no route found for redirect dst: %s\n", 2305 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2306 goto bad; 2307 } 2308 } 2309 if (IN6_IS_ADDR_MULTICAST(&reddst6)) { 2310 nd6log((LOG_ERR, 2311 "ICMP6 redirect rejected; " 2312 "redirect dst must be unicast: %s\n", 2313 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2314 goto bad; 2315 } 2316 2317 is_router = is_onlink = 0; 2318 if (IN6_IS_ADDR_LINKLOCAL(&redtgt6)) 2319 is_router = 1; /* router case */ 2320 if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0) 2321 is_onlink = 1; /* on-link destination case */ 2322 if (!is_router && !is_onlink) { 2323 nd6log((LOG_ERR, 2324 "ICMP6 redirect rejected; " 2325 "neither router case nor onlink case: %s\n", 2326 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2327 goto bad; 2328 } 2329 2330 icmp6len -= sizeof(*nd_rd); 2331 nd6_option_init(nd_rd + 1, icmp6len, &ndopts); 2332 if (nd6_options(&ndopts) < 0) { 2333 nd6log((LOG_INFO, "%s: invalid ND option, rejected: %s\n", 2334 __func__, icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2335 /* nd6_options have incremented stats */ 2336 goto freeit; 2337 } 2338 2339 lladdr = NULL; 2340 lladdrlen = 0; 2341 if (ndopts.nd_opts_tgt_lladdr) { 2342 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 2343 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 2344 } 2345 2346 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 2347 nd6log((LOG_INFO, "%s: lladdrlen mismatch for %s " 2348 "(if %d, icmp6 packet %d): %s\n", 2349 __func__, ip6_sprintf(ip6buf, &redtgt6), 2350 ifp->if_addrlen, lladdrlen - 2, 2351 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2352 goto bad; 2353 } 2354 2355 /* Validation passed. */ 2356 2357 /* RFC 2461 8.3 */ 2358 nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT, 2359 is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER); 2360 2361 /* 2362 * Install a gateway route in the better-router case or an interface 2363 * route in the on-link-destination case. 2364 */ 2365 { 2366 struct sockaddr_in6 sdst; 2367 struct sockaddr_in6 sgw; 2368 struct sockaddr_in6 ssrc; 2369 struct sockaddr *gw; 2370 int rt_flags; 2371 u_int fibnum; 2372 2373 bzero(&sdst, sizeof(sdst)); 2374 bzero(&ssrc, sizeof(ssrc)); 2375 sdst.sin6_family = ssrc.sin6_family = AF_INET6; 2376 sdst.sin6_len = ssrc.sin6_len = sizeof(struct sockaddr_in6); 2377 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr)); 2378 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr)); 2379 rt_flags = 0; 2380 if (is_router) { 2381 bzero(&sgw, sizeof(sgw)); 2382 sgw.sin6_family = AF_INET6; 2383 sgw.sin6_len = sizeof(struct sockaddr_in6); 2384 bcopy(&redtgt6, &sgw.sin6_addr, 2385 sizeof(struct in6_addr)); 2386 gw = (struct sockaddr *)&sgw; 2387 rt_flags |= RTF_GATEWAY; 2388 } else 2389 gw = ifp->if_addr->ifa_addr; 2390 for (fibnum = 0; fibnum < rt_numfibs; fibnum++) 2391 rib_add_redirect(fibnum, (struct sockaddr *)&sdst, gw, 2392 (struct sockaddr *)&ssrc, ifp, rt_flags, 2393 V_icmp6_redirtimeout); 2394 } 2395 /* finally update cached route in each socket via pfctlinput */ 2396 { 2397 struct sockaddr_in6 sdst; 2398 2399 bzero(&sdst, sizeof(sdst)); 2400 sdst.sin6_family = AF_INET6; 2401 sdst.sin6_len = sizeof(struct sockaddr_in6); 2402 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr)); 2403 pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst); 2404 } 2405 2406 freeit: 2407 m_freem(m); 2408 return; 2409 2410 bad: 2411 ICMP6STAT_INC(icp6s_badredirect); 2412 m_freem(m); 2413 } 2414 2415 void 2416 icmp6_redirect_output(struct mbuf *m0, struct nhop_object *nh) 2417 { 2418 struct ifnet *ifp; /* my outgoing interface */ 2419 struct in6_addr *ifp_ll6; 2420 struct in6_addr *router_ll6; 2421 struct ip6_hdr *sip6; /* m0 as struct ip6_hdr */ 2422 struct mbuf *m = NULL; /* newly allocated one */ 2423 struct m_tag *mtag; 2424 struct ip6_hdr *ip6; /* m as struct ip6_hdr */ 2425 struct nd_redirect *nd_rd; 2426 struct llentry *ln = NULL; 2427 size_t maxlen; 2428 u_char *p; 2429 struct ifnet *outif = NULL; 2430 struct sockaddr_in6 src_sa; 2431 2432 icmp6_errcount(ND_REDIRECT, 0); 2433 2434 /* if we are not router, we don't send icmp6 redirect */ 2435 if (!V_ip6_forwarding) 2436 goto fail; 2437 2438 /* sanity check */ 2439 if (!m0 || !nh || !(NH_IS_VALID(nh)) || !(ifp = nh->nh_ifp)) 2440 goto fail; 2441 2442 /* 2443 * Address check: 2444 * the source address must identify a neighbor, and 2445 * the destination address must not be a multicast address 2446 * [RFC 2461, sec 8.2] 2447 */ 2448 sip6 = mtod(m0, struct ip6_hdr *); 2449 bzero(&src_sa, sizeof(src_sa)); 2450 src_sa.sin6_family = AF_INET6; 2451 src_sa.sin6_len = sizeof(src_sa); 2452 src_sa.sin6_addr = sip6->ip6_src; 2453 if (nd6_is_addr_neighbor(&src_sa, ifp) == 0) 2454 goto fail; 2455 if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst)) 2456 goto fail; /* what should we do here? */ 2457 2458 /* rate limit */ 2459 if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0)) 2460 goto fail; 2461 2462 /* 2463 * Since we are going to append up to 1280 bytes (= IPV6_MMTU), 2464 * we almost always ask for an mbuf cluster for simplicity. 2465 * (MHLEN < IPV6_MMTU is almost always true) 2466 */ 2467 #if IPV6_MMTU >= MCLBYTES 2468 # error assumption failed about IPV6_MMTU and MCLBYTES 2469 #endif 2470 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 2471 if (m == NULL) 2472 goto fail; 2473 M_SETFIB(m, M_GETFIB(m0)); 2474 maxlen = M_TRAILINGSPACE(m); 2475 maxlen = min(IPV6_MMTU, maxlen); 2476 /* just for safety */ 2477 if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) + 2478 ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) { 2479 goto fail; 2480 } 2481 2482 { 2483 /* get ip6 linklocal address for ifp(my outgoing interface). */ 2484 struct in6_ifaddr *ia; 2485 if ((ia = in6ifa_ifpforlinklocal(ifp, 2486 IN6_IFF_NOTREADY| 2487 IN6_IFF_ANYCAST)) == NULL) 2488 goto fail; 2489 ifp_ll6 = &ia->ia_addr.sin6_addr; 2490 /* XXXRW: reference released prematurely. */ 2491 ifa_free(&ia->ia_ifa); 2492 } 2493 2494 /* get ip6 linklocal address for the router. */ 2495 if (nh->nh_flags & NHF_GATEWAY) { 2496 struct sockaddr_in6 *sin6; 2497 sin6 = &nh->gw6_sa; 2498 router_ll6 = &sin6->sin6_addr; 2499 if (!IN6_IS_ADDR_LINKLOCAL(router_ll6)) 2500 router_ll6 = (struct in6_addr *)NULL; 2501 } else 2502 router_ll6 = (struct in6_addr *)NULL; 2503 2504 /* ip6 */ 2505 ip6 = mtod(m, struct ip6_hdr *); 2506 ip6->ip6_flow = 0; 2507 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2508 ip6->ip6_vfc |= IPV6_VERSION; 2509 /* ip6->ip6_plen will be set later */ 2510 ip6->ip6_nxt = IPPROTO_ICMPV6; 2511 ip6->ip6_hlim = 255; 2512 /* ip6->ip6_src must be linklocal addr for my outgoing if. */ 2513 bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr)); 2514 bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr)); 2515 2516 /* ND Redirect */ 2517 nd_rd = (struct nd_redirect *)(ip6 + 1); 2518 nd_rd->nd_rd_type = ND_REDIRECT; 2519 nd_rd->nd_rd_code = 0; 2520 nd_rd->nd_rd_reserved = 0; 2521 if (nh->nh_flags & NHF_GATEWAY) { 2522 /* 2523 * nd_rd->nd_rd_target must be a link-local address in 2524 * better router cases. 2525 */ 2526 if (!router_ll6) 2527 goto fail; 2528 bcopy(router_ll6, &nd_rd->nd_rd_target, 2529 sizeof(nd_rd->nd_rd_target)); 2530 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2531 sizeof(nd_rd->nd_rd_dst)); 2532 } else { 2533 /* make sure redtgt == reddst */ 2534 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target, 2535 sizeof(nd_rd->nd_rd_target)); 2536 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2537 sizeof(nd_rd->nd_rd_dst)); 2538 } 2539 2540 p = (u_char *)(nd_rd + 1); 2541 2542 if (!router_ll6) 2543 goto nolladdropt; 2544 2545 { 2546 /* target lladdr option */ 2547 int len; 2548 struct nd_opt_hdr *nd_opt; 2549 char *lladdr; 2550 2551 ln = nd6_lookup(router_ll6, 0, ifp); 2552 if (ln == NULL) 2553 goto nolladdropt; 2554 2555 len = sizeof(*nd_opt) + ifp->if_addrlen; 2556 len = (len + 7) & ~7; /* round by 8 */ 2557 /* safety check */ 2558 if (len + (p - (u_char *)ip6) > maxlen) 2559 goto nolladdropt; 2560 2561 if (ln->la_flags & LLE_VALID) { 2562 nd_opt = (struct nd_opt_hdr *)p; 2563 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 2564 nd_opt->nd_opt_len = len >> 3; 2565 lladdr = (char *)(nd_opt + 1); 2566 bcopy(ln->ll_addr, lladdr, ifp->if_addrlen); 2567 p += len; 2568 } 2569 } 2570 nolladdropt: 2571 if (ln != NULL) 2572 LLE_RUNLOCK(ln); 2573 2574 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2575 2576 /* just to be safe */ 2577 #ifdef M_DECRYPTED /*not openbsd*/ 2578 if (m0->m_flags & M_DECRYPTED) 2579 goto noredhdropt; 2580 #endif 2581 if (p - (u_char *)ip6 > maxlen) 2582 goto noredhdropt; 2583 2584 { 2585 /* redirected header option */ 2586 int len; 2587 struct nd_opt_rd_hdr *nd_opt_rh; 2588 2589 /* 2590 * compute the maximum size for icmp6 redirect header option. 2591 * XXX room for auth header? 2592 */ 2593 len = maxlen - (p - (u_char *)ip6); 2594 len &= ~7; 2595 2596 /* This is just for simplicity. */ 2597 if (m0->m_pkthdr.len != m0->m_len) { 2598 if (m0->m_next) { 2599 m_freem(m0->m_next); 2600 m0->m_next = NULL; 2601 } 2602 m0->m_pkthdr.len = m0->m_len; 2603 } 2604 2605 /* 2606 * Redirected header option spec (RFC2461 4.6.3) talks nothing 2607 * about padding/truncate rule for the original IP packet. 2608 * From the discussion on IPv6imp in Feb 1999, 2609 * the consensus was: 2610 * - "attach as much as possible" is the goal 2611 * - pad if not aligned (original size can be guessed by 2612 * original ip6 header) 2613 * Following code adds the padding if it is simple enough, 2614 * and truncates if not. 2615 */ 2616 if (m0->m_next || m0->m_pkthdr.len != m0->m_len) 2617 panic("assumption failed in %s:%d", __FILE__, 2618 __LINE__); 2619 2620 if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) { 2621 /* not enough room, truncate */ 2622 m0->m_pkthdr.len = m0->m_len = len - 2623 sizeof(*nd_opt_rh); 2624 } else { 2625 /* enough room, pad or truncate */ 2626 size_t extra; 2627 2628 extra = m0->m_pkthdr.len % 8; 2629 if (extra) { 2630 /* pad if easy enough, truncate if not */ 2631 if (8 - extra <= M_TRAILINGSPACE(m0)) { 2632 /* pad */ 2633 m0->m_len += (8 - extra); 2634 m0->m_pkthdr.len += (8 - extra); 2635 } else { 2636 /* truncate */ 2637 m0->m_pkthdr.len -= extra; 2638 m0->m_len -= extra; 2639 } 2640 } 2641 len = m0->m_pkthdr.len + sizeof(*nd_opt_rh); 2642 m0->m_pkthdr.len = m0->m_len = len - 2643 sizeof(*nd_opt_rh); 2644 } 2645 2646 nd_opt_rh = (struct nd_opt_rd_hdr *)p; 2647 bzero(nd_opt_rh, sizeof(*nd_opt_rh)); 2648 nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER; 2649 nd_opt_rh->nd_opt_rh_len = len >> 3; 2650 p += sizeof(*nd_opt_rh); 2651 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2652 2653 /* connect m0 to m */ 2654 m_tag_delete_chain(m0, NULL); 2655 m0->m_flags &= ~M_PKTHDR; 2656 m->m_next = m0; 2657 m->m_pkthdr.len = m->m_len + m0->m_len; 2658 m0 = NULL; 2659 } 2660 noredhdropt:; 2661 if (m0) { 2662 m_freem(m0); 2663 m0 = NULL; 2664 } 2665 2666 /* XXX: clear embedded link IDs in the inner header */ 2667 in6_clearscope(&sip6->ip6_src); 2668 in6_clearscope(&sip6->ip6_dst); 2669 in6_clearscope(&nd_rd->nd_rd_target); 2670 in6_clearscope(&nd_rd->nd_rd_dst); 2671 2672 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr)); 2673 2674 nd_rd->nd_rd_cksum = 0; 2675 nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2676 sizeof(*ip6), ntohs(ip6->ip6_plen)); 2677 2678 if (send_sendso_input_hook != NULL) { 2679 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, sizeof(unsigned short), 2680 M_NOWAIT); 2681 if (mtag == NULL) 2682 goto fail; 2683 *(unsigned short *)(mtag + 1) = nd_rd->nd_rd_type; 2684 m_tag_prepend(m, mtag); 2685 } 2686 2687 /* send the packet to outside... */ 2688 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2689 if (outif) { 2690 icmp6_ifstat_inc(outif, ifs6_out_msg); 2691 icmp6_ifstat_inc(outif, ifs6_out_redirect); 2692 } 2693 ICMP6STAT_INC(icp6s_outhist[ND_REDIRECT]); 2694 2695 return; 2696 2697 fail: 2698 if (m) 2699 m_freem(m); 2700 if (m0) 2701 m_freem(m0); 2702 } 2703 2704 /* 2705 * ICMPv6 socket option processing. 2706 */ 2707 int 2708 icmp6_ctloutput(struct socket *so, struct sockopt *sopt) 2709 { 2710 int error = 0; 2711 int optlen; 2712 struct inpcb *inp = sotoinpcb(so); 2713 int level, op, optname; 2714 2715 if (sopt) { 2716 level = sopt->sopt_level; 2717 op = sopt->sopt_dir; 2718 optname = sopt->sopt_name; 2719 optlen = sopt->sopt_valsize; 2720 } else 2721 level = op = optname = optlen = 0; 2722 2723 if (level != IPPROTO_ICMPV6) { 2724 return EINVAL; 2725 } 2726 2727 switch (op) { 2728 case PRCO_SETOPT: 2729 switch (optname) { 2730 case ICMP6_FILTER: 2731 { 2732 struct icmp6_filter ic6f; 2733 2734 if (optlen != sizeof(ic6f)) { 2735 error = EMSGSIZE; 2736 break; 2737 } 2738 error = sooptcopyin(sopt, &ic6f, optlen, optlen); 2739 if (error == 0) { 2740 INP_WLOCK(inp); 2741 *inp->in6p_icmp6filt = ic6f; 2742 INP_WUNLOCK(inp); 2743 } 2744 break; 2745 } 2746 2747 default: 2748 error = ENOPROTOOPT; 2749 break; 2750 } 2751 break; 2752 2753 case PRCO_GETOPT: 2754 switch (optname) { 2755 case ICMP6_FILTER: 2756 { 2757 struct icmp6_filter ic6f; 2758 2759 INP_RLOCK(inp); 2760 ic6f = *inp->in6p_icmp6filt; 2761 INP_RUNLOCK(inp); 2762 error = sooptcopyout(sopt, &ic6f, sizeof(ic6f)); 2763 break; 2764 } 2765 2766 default: 2767 error = ENOPROTOOPT; 2768 break; 2769 } 2770 break; 2771 } 2772 2773 return (error); 2774 } 2775 2776 /* 2777 * Perform rate limit check. 2778 * Returns 0 if it is okay to send the icmp6 packet. 2779 * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate 2780 * limitation. 2781 * 2782 * XXX per-destination/type check necessary? 2783 * 2784 * dst - not used at this moment 2785 * type - not used at this moment 2786 * code - not used at this moment 2787 */ 2788 static int 2789 icmp6_ratelimit(const struct in6_addr *dst, const int type, 2790 const int code) 2791 { 2792 int ret; 2793 2794 ret = 0; /* okay to send */ 2795 2796 /* PPS limit */ 2797 if (!ppsratecheck(&V_icmp6errppslim_last, &V_icmp6errpps_count, 2798 V_icmp6errppslim)) { 2799 /* The packet is subject to rate limit */ 2800 ret++; 2801 } 2802 2803 return ret; 2804 } 2805