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/vnet.h> 97 98 #include <netinet/in.h> 99 #include <netinet/in_pcb.h> 100 #include <netinet/in_var.h> 101 #include <netinet/ip6.h> 102 #include <netinet/icmp6.h> 103 #include <netinet/tcp_var.h> 104 105 #include <netinet6/in6_fib.h> 106 #include <netinet6/in6_ifattach.h> 107 #include <netinet6/in6_pcb.h> 108 #include <netinet6/ip6protosw.h> 109 #include <netinet6/ip6_var.h> 110 #include <netinet6/scope6_var.h> 111 #include <netinet6/mld6_var.h> 112 #include <netinet6/nd6.h> 113 #include <netinet6/send.h> 114 115 extern struct domain inet6domain; 116 117 VNET_PCPUSTAT_DEFINE(struct icmp6stat, icmp6stat); 118 VNET_PCPUSTAT_SYSINIT(icmp6stat); 119 120 #ifdef VIMAGE 121 VNET_PCPUSTAT_SYSUNINIT(icmp6stat); 122 #endif /* VIMAGE */ 123 124 VNET_DECLARE(struct inpcbinfo, ripcbinfo); 125 VNET_DECLARE(struct inpcbhead, ripcb); 126 VNET_DECLARE(int, icmp6errppslim); 127 VNET_DEFINE_STATIC(int, icmp6errpps_count) = 0; 128 VNET_DEFINE_STATIC(struct timeval, icmp6errppslim_last); 129 VNET_DECLARE(int, icmp6_nodeinfo); 130 131 #define V_ripcbinfo VNET(ripcbinfo) 132 #define V_ripcb VNET(ripcb) 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 int icmp6_ratelimit(const struct in6_addr *, const int, const int); 141 static const char *icmp6_redirect_diag(struct in6_addr *, 142 struct in6_addr *, struct in6_addr *); 143 static struct mbuf *ni6_input(struct mbuf *, int, struct prison *); 144 static struct mbuf *ni6_nametodns(const char *, int, int); 145 static int ni6_dnsmatch(const char *, int, const char *, int); 146 static int ni6_addrs(struct icmp6_nodeinfo *, struct mbuf *, 147 struct ifnet **, struct in6_addr *); 148 static int ni6_store_addrs(struct icmp6_nodeinfo *, struct icmp6_nodeinfo *, 149 struct ifnet *, int); 150 static int icmp6_notify_error(struct mbuf **, int, int, int); 151 152 /* 153 * Kernel module interface for updating icmp6stat. The argument is an index 154 * into icmp6stat treated as an array of u_quad_t. While this encodes the 155 * general layout of icmp6stat into the caller, it doesn't encode its 156 * location, so that future changes to add, for example, per-CPU stats 157 * support won't cause binary compatibility problems for kernel modules. 158 */ 159 void 160 kmod_icmp6stat_inc(int statnum) 161 { 162 163 counter_u64_add(VNET(icmp6stat)[statnum], 1); 164 } 165 166 static void 167 icmp6_errcount(int type, int code) 168 { 169 switch (type) { 170 case ICMP6_DST_UNREACH: 171 switch (code) { 172 case ICMP6_DST_UNREACH_NOROUTE: 173 ICMP6STAT_INC(icp6s_odst_unreach_noroute); 174 return; 175 case ICMP6_DST_UNREACH_ADMIN: 176 ICMP6STAT_INC(icp6s_odst_unreach_admin); 177 return; 178 case ICMP6_DST_UNREACH_BEYONDSCOPE: 179 ICMP6STAT_INC(icp6s_odst_unreach_beyondscope); 180 return; 181 case ICMP6_DST_UNREACH_ADDR: 182 ICMP6STAT_INC(icp6s_odst_unreach_addr); 183 return; 184 case ICMP6_DST_UNREACH_NOPORT: 185 ICMP6STAT_INC(icp6s_odst_unreach_noport); 186 return; 187 } 188 break; 189 case ICMP6_PACKET_TOO_BIG: 190 ICMP6STAT_INC(icp6s_opacket_too_big); 191 return; 192 case ICMP6_TIME_EXCEEDED: 193 switch (code) { 194 case ICMP6_TIME_EXCEED_TRANSIT: 195 ICMP6STAT_INC(icp6s_otime_exceed_transit); 196 return; 197 case ICMP6_TIME_EXCEED_REASSEMBLY: 198 ICMP6STAT_INC(icp6s_otime_exceed_reassembly); 199 return; 200 } 201 break; 202 case ICMP6_PARAM_PROB: 203 switch (code) { 204 case ICMP6_PARAMPROB_HEADER: 205 ICMP6STAT_INC(icp6s_oparamprob_header); 206 return; 207 case ICMP6_PARAMPROB_NEXTHEADER: 208 ICMP6STAT_INC(icp6s_oparamprob_nextheader); 209 return; 210 case ICMP6_PARAMPROB_OPTION: 211 ICMP6STAT_INC(icp6s_oparamprob_option); 212 return; 213 } 214 break; 215 case ND_REDIRECT: 216 ICMP6STAT_INC(icp6s_oredirect); 217 return; 218 } 219 ICMP6STAT_INC(icp6s_ounknown); 220 } 221 222 /* 223 * A wrapper function for icmp6_error() necessary when the erroneous packet 224 * may not contain enough scope zone information. 225 */ 226 void 227 icmp6_error2(struct mbuf *m, int type, int code, int param, 228 struct ifnet *ifp) 229 { 230 struct ip6_hdr *ip6; 231 232 if (ifp == NULL) 233 return; 234 235 if (m->m_len < sizeof(struct ip6_hdr)) { 236 m = m_pullup(m, sizeof(struct ip6_hdr)); 237 if (m == NULL) { 238 IP6STAT_INC(ip6s_exthdrtoolong); 239 return; 240 } 241 } 242 ip6 = mtod(m, struct ip6_hdr *); 243 244 if (in6_setscope(&ip6->ip6_src, ifp, NULL) != 0) 245 return; 246 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0) 247 return; 248 249 icmp6_error(m, type, code, param); 250 } 251 252 /* 253 * Generate an error packet of type error in response to bad IP6 packet. 254 */ 255 void 256 icmp6_error(struct mbuf *m, int type, int code, int param) 257 { 258 struct ip6_hdr *oip6, *nip6; 259 struct icmp6_hdr *icmp6; 260 u_int preplen; 261 int off; 262 int nxt; 263 264 ICMP6STAT_INC(icp6s_error); 265 266 /* count per-type-code statistics */ 267 icmp6_errcount(type, code); 268 269 #ifdef M_DECRYPTED /*not openbsd*/ 270 if (m->m_flags & M_DECRYPTED) { 271 ICMP6STAT_INC(icp6s_canterror); 272 goto freeit; 273 } 274 #endif 275 276 if (m->m_len < sizeof(struct ip6_hdr)) { 277 m = m_pullup(m, sizeof(struct ip6_hdr)); 278 if (m == NULL) { 279 IP6STAT_INC(ip6s_exthdrtoolong); 280 return; 281 } 282 } 283 oip6 = mtod(m, struct ip6_hdr *); 284 285 /* 286 * If the destination address of the erroneous packet is a multicast 287 * address, or the packet was sent using link-layer multicast, 288 * we should basically suppress sending an error (RFC 2463, Section 289 * 2.4). 290 * We have two exceptions (the item e.2 in that section): 291 * - the Packet Too Big message can be sent for path MTU discovery. 292 * - the Parameter Problem Message that can be allowed an icmp6 error 293 * in the option type field. This check has been done in 294 * ip6_unknown_opt(), so we can just check the type and code. 295 */ 296 if ((m->m_flags & (M_BCAST|M_MCAST) || 297 IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) && 298 (type != ICMP6_PACKET_TOO_BIG && 299 (type != ICMP6_PARAM_PROB || 300 code != ICMP6_PARAMPROB_OPTION))) 301 goto freeit; 302 303 /* 304 * RFC 2463, 2.4 (e.5): source address check. 305 * XXX: the case of anycast source? 306 */ 307 if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) || 308 IN6_IS_ADDR_MULTICAST(&oip6->ip6_src)) 309 goto freeit; 310 311 /* 312 * If we are about to send ICMPv6 against ICMPv6 error/redirect, 313 * don't do it. 314 */ 315 nxt = -1; 316 off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt); 317 if (off >= 0 && nxt == IPPROTO_ICMPV6) { 318 struct icmp6_hdr *icp; 319 320 m = m_pullup(m, off + sizeof(struct icmp6_hdr)); 321 if (m == NULL) { 322 IP6STAT_INC(ip6s_exthdrtoolong); 323 return; 324 } 325 oip6 = mtod(m, struct ip6_hdr *); 326 icp = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 327 328 if (icp->icmp6_type < ICMP6_ECHO_REQUEST || 329 icp->icmp6_type == ND_REDIRECT) { 330 /* 331 * ICMPv6 error 332 * Special case: for redirect (which is 333 * informational) we must not send icmp6 error. 334 */ 335 ICMP6STAT_INC(icp6s_canterror); 336 goto freeit; 337 } else { 338 /* ICMPv6 informational - send the error */ 339 } 340 } else { 341 /* non-ICMPv6 - send the error */ 342 } 343 344 /* Finally, do rate limitation check. */ 345 if (icmp6_ratelimit(&oip6->ip6_src, type, code)) { 346 ICMP6STAT_INC(icp6s_toofreq); 347 goto freeit; 348 } 349 350 /* 351 * OK, ICMP6 can be generated. 352 */ 353 354 if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN) 355 m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len); 356 357 preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 358 M_PREPEND(m, preplen, M_NOWAIT); /* FIB is also copied over. */ 359 if (m == NULL) { 360 nd6log((LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__)); 361 return; 362 } 363 364 nip6 = mtod(m, struct ip6_hdr *); 365 nip6->ip6_src = oip6->ip6_src; 366 nip6->ip6_dst = oip6->ip6_dst; 367 368 in6_clearscope(&oip6->ip6_src); 369 in6_clearscope(&oip6->ip6_dst); 370 371 icmp6 = (struct icmp6_hdr *)(nip6 + 1); 372 icmp6->icmp6_type = type; 373 icmp6->icmp6_code = code; 374 icmp6->icmp6_pptr = htonl((u_int32_t)param); 375 376 ICMP6STAT_INC(icp6s_outhist[type]); 377 icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */ 378 379 return; 380 381 freeit: 382 /* 383 * If we can't tell whether or not we can generate ICMP6, free it. 384 */ 385 m_freem(m); 386 } 387 388 /* 389 * Process a received ICMP6 message. 390 */ 391 int 392 icmp6_input(struct mbuf **mp, int *offp, int proto) 393 { 394 struct mbuf *m, *n; 395 struct ifnet *ifp; 396 struct ip6_hdr *ip6, *nip6; 397 struct icmp6_hdr *icmp6, *nicmp6; 398 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 399 int code, error, icmp6len, ip6len, noff, off, sum; 400 401 m = *mp; 402 off = *offp; 403 404 m = m_pullup(m, off + sizeof(struct icmp6_hdr)); 405 if (m == NULL) { 406 IP6STAT_INC(ip6s_exthdrtoolong); 407 *mp = m; 408 return (IPPROTO_DONE); 409 } 410 411 /* 412 * Locate icmp6 structure in mbuf, and check 413 * that not corrupted and of at least minimum length 414 */ 415 416 icmp6len = m->m_pkthdr.len - off; 417 if (icmp6len < sizeof(struct icmp6_hdr)) { 418 ICMP6STAT_INC(icp6s_tooshort); 419 goto freeit; 420 } 421 422 ip6 = mtod(m, struct ip6_hdr *); 423 ifp = m->m_pkthdr.rcvif; 424 /* 425 * Check multicast group membership. 426 * Note: SSM filters are not applied for ICMPv6 traffic. 427 */ 428 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 429 struct in6_multi *inm; 430 431 inm = in6m_lookup(ifp, &ip6->ip6_dst); 432 if (inm == NULL) { 433 IP6STAT_INC(ip6s_notmember); 434 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 435 goto freeit; 436 } 437 } 438 439 /* Calculate the checksum. */ 440 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off); 441 code = icmp6->icmp6_code; 442 if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) { 443 nd6log((LOG_ERR, 444 "ICMP6 checksum error(%d|%x) %s\n", 445 icmp6->icmp6_type, sum, 446 ip6_sprintf(ip6bufs, &ip6->ip6_src))); 447 ICMP6STAT_INC(icp6s_checksum); 448 goto freeit; 449 } 450 451 ICMP6STAT_INC(icp6s_inhist[icmp6->icmp6_type]); 452 icmp6_ifstat_inc(ifp, ifs6_in_msg); 453 if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK) 454 icmp6_ifstat_inc(ifp, ifs6_in_error); 455 456 ip6len = sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen); 457 switch (icmp6->icmp6_type) { 458 case ICMP6_DST_UNREACH: 459 icmp6_ifstat_inc(ifp, ifs6_in_dstunreach); 460 switch (code) { 461 case ICMP6_DST_UNREACH_NOROUTE: 462 case ICMP6_DST_UNREACH_ADDR: /* PRC_HOSTDEAD is a DOS */ 463 code = PRC_UNREACH_NET; 464 break; 465 case ICMP6_DST_UNREACH_ADMIN: 466 icmp6_ifstat_inc(ifp, ifs6_in_adminprohib); 467 code = PRC_UNREACH_ADMIN_PROHIB; 468 break; 469 case ICMP6_DST_UNREACH_BEYONDSCOPE: 470 /* I mean "source address was incorrect." */ 471 code = PRC_PARAMPROB; 472 break; 473 case ICMP6_DST_UNREACH_NOPORT: 474 code = PRC_UNREACH_PORT; 475 break; 476 default: 477 goto badcode; 478 } 479 goto deliver; 480 break; 481 482 case ICMP6_PACKET_TOO_BIG: 483 icmp6_ifstat_inc(ifp, ifs6_in_pkttoobig); 484 485 /* validation is made in icmp6_mtudisc_update */ 486 487 code = PRC_MSGSIZE; 488 489 /* 490 * Updating the path MTU will be done after examining 491 * intermediate extension headers. 492 */ 493 goto deliver; 494 break; 495 496 case ICMP6_TIME_EXCEEDED: 497 icmp6_ifstat_inc(ifp, ifs6_in_timeexceed); 498 switch (code) { 499 case ICMP6_TIME_EXCEED_TRANSIT: 500 code = PRC_TIMXCEED_INTRANS; 501 break; 502 case ICMP6_TIME_EXCEED_REASSEMBLY: 503 code = PRC_TIMXCEED_REASS; 504 break; 505 default: 506 goto badcode; 507 } 508 goto deliver; 509 break; 510 511 case ICMP6_PARAM_PROB: 512 icmp6_ifstat_inc(ifp, ifs6_in_paramprob); 513 switch (code) { 514 case ICMP6_PARAMPROB_NEXTHEADER: 515 code = PRC_UNREACH_PROTOCOL; 516 break; 517 case ICMP6_PARAMPROB_HEADER: 518 case ICMP6_PARAMPROB_OPTION: 519 code = PRC_PARAMPROB; 520 break; 521 default: 522 goto badcode; 523 } 524 goto deliver; 525 break; 526 527 case ICMP6_ECHO_REQUEST: 528 icmp6_ifstat_inc(ifp, ifs6_in_echo); 529 if (code != 0) 530 goto badcode; 531 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) { 532 /* Give up remote */ 533 break; 534 } 535 if (!M_WRITABLE(n) 536 || n->m_len < off + sizeof(struct icmp6_hdr)) { 537 struct mbuf *n0 = n; 538 int n0len; 539 540 CTASSERT(sizeof(*nip6) + sizeof(*nicmp6) <= MHLEN); 541 n = m_gethdr(M_NOWAIT, n0->m_type); 542 if (n == NULL) { 543 /* Give up remote */ 544 m_freem(n0); 545 break; 546 } 547 548 m_move_pkthdr(n, n0); /* FIB copied. */ 549 n0len = n0->m_pkthdr.len; /* save for use below */ 550 /* 551 * Copy IPv6 and ICMPv6 only. 552 */ 553 nip6 = mtod(n, struct ip6_hdr *); 554 bcopy(ip6, nip6, sizeof(struct ip6_hdr)); 555 nicmp6 = (struct icmp6_hdr *)(nip6 + 1); 556 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr)); 557 noff = sizeof(struct ip6_hdr); 558 /* new mbuf contains only ipv6+icmpv6 headers */ 559 n->m_len = noff + sizeof(struct icmp6_hdr); 560 /* 561 * Adjust mbuf. ip6_plen will be adjusted in 562 * ip6_output(). 563 */ 564 m_adj(n0, off + sizeof(struct icmp6_hdr)); 565 /* recalculate complete packet size */ 566 n->m_pkthdr.len = n0len + (noff - off); 567 n->m_next = n0; 568 } else { 569 n = m_pullup(n, off + sizeof(*nicmp6)); 570 if (n == NULL) { 571 IP6STAT_INC(ip6s_exthdrtoolong); 572 break; 573 } 574 nicmp6 = (struct icmp6_hdr *)(mtod(n, caddr_t) + off); 575 noff = off; 576 } 577 if (n) { 578 nicmp6->icmp6_type = ICMP6_ECHO_REPLY; 579 nicmp6->icmp6_code = 0; 580 ICMP6STAT_INC(icp6s_reflect); 581 ICMP6STAT_INC(icp6s_outhist[ICMP6_ECHO_REPLY]); 582 icmp6_reflect(n, noff); 583 } 584 break; 585 586 case ICMP6_ECHO_REPLY: 587 icmp6_ifstat_inc(ifp, ifs6_in_echoreply); 588 if (code != 0) 589 goto badcode; 590 break; 591 592 case MLD_LISTENER_QUERY: 593 case MLD_LISTENER_REPORT: 594 case MLD_LISTENER_DONE: 595 case MLDV2_LISTENER_REPORT: 596 /* 597 * Drop MLD traffic which is not link-local, has a hop limit 598 * of greater than 1 hop, or which does not have the 599 * IPv6 HBH Router Alert option. 600 * As IPv6 HBH options are stripped in ip6_input() we must 601 * check an mbuf header flag. 602 * XXX Should we also sanity check that these messages 603 * were directed to a link-local multicast prefix? 604 */ 605 if ((ip6->ip6_hlim != 1) || (m->m_flags & M_RTALERT_MLD) == 0) 606 goto freeit; 607 if (mld_input(&m, off, icmp6len) != 0) { 608 *mp = NULL; 609 return (IPPROTO_DONE); 610 } 611 /* m stays. */ 612 break; 613 614 case ICMP6_WRUREQUEST: /* ICMP6_FQDN_QUERY */ 615 { 616 enum { WRU, FQDN } mode; 617 struct prison *pr; 618 619 if (!V_icmp6_nodeinfo) 620 break; 621 622 if (icmp6len == sizeof(struct icmp6_hdr) + 4) 623 mode = WRU; 624 else if (icmp6len >= sizeof(struct icmp6_nodeinfo)) 625 mode = FQDN; 626 else 627 goto badlen; 628 629 pr = NULL; 630 sx_slock(&allprison_lock); 631 TAILQ_FOREACH(pr, &allprison, pr_list) 632 if (pr->pr_vnet == ifp->if_vnet) 633 break; 634 sx_sunlock(&allprison_lock); 635 if (pr == NULL) 636 pr = curthread->td_ucred->cr_prison; 637 if (mode == FQDN) { 638 m = m_pullup(m, off + sizeof(struct icmp6_nodeinfo)); 639 if (m == NULL) { 640 IP6STAT_INC(ip6s_exthdrtoolong); 641 *mp = m; 642 return (IPPROTO_DONE); 643 } 644 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 645 if (n) 646 n = ni6_input(n, off, pr); 647 /* XXX meaningless if n == NULL */ 648 noff = sizeof(struct ip6_hdr); 649 } else { 650 u_char *p; 651 int maxhlen, hlen; 652 653 /* 654 * XXX: this combination of flags is pointless, 655 * but should we keep this for compatibility? 656 */ 657 if ((V_icmp6_nodeinfo & (ICMP6_NODEINFO_FQDNOK | 658 ICMP6_NODEINFO_TMPADDROK)) != 659 (ICMP6_NODEINFO_FQDNOK | ICMP6_NODEINFO_TMPADDROK)) 660 break; 661 662 if (code != 0) 663 goto badcode; 664 665 CTASSERT(sizeof(*nip6) + sizeof(*nicmp6) + 4 <= MHLEN); 666 n = m_gethdr(M_NOWAIT, m->m_type); 667 if (n == NULL) { 668 /* Give up remote */ 669 break; 670 } 671 if (!m_dup_pkthdr(n, m, M_NOWAIT)) { 672 /* 673 * Previous code did a blind M_COPY_PKTHDR 674 * and said "just for rcvif". If true, then 675 * we could tolerate the dup failing (due to 676 * the deep copy of the tag chain). For now 677 * be conservative and just fail. 678 */ 679 m_free(n); 680 n = NULL; 681 break; 682 } 683 /* 684 * Copy IPv6 and ICMPv6 only. 685 */ 686 nip6 = mtod(n, struct ip6_hdr *); 687 bcopy(ip6, nip6, sizeof(struct ip6_hdr)); 688 nicmp6 = (struct icmp6_hdr *)(nip6 + 1); 689 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr)); 690 p = (u_char *)(nicmp6 + 1); 691 bzero(p, 4); 692 693 maxhlen = M_TRAILINGSPACE(n) - 694 (sizeof(*nip6) + sizeof(*nicmp6) + 4); 695 mtx_lock(&pr->pr_mtx); 696 hlen = strlen(pr->pr_hostname); 697 if (maxhlen > hlen) 698 maxhlen = hlen; 699 /* meaningless TTL */ 700 bcopy(pr->pr_hostname, p + 4, maxhlen); 701 mtx_unlock(&pr->pr_mtx); 702 noff = sizeof(struct ip6_hdr); 703 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + 704 sizeof(struct icmp6_hdr) + 4 + maxhlen; 705 nicmp6->icmp6_type = ICMP6_WRUREPLY; 706 nicmp6->icmp6_code = 0; 707 } 708 if (n) { 709 ICMP6STAT_INC(icp6s_reflect); 710 ICMP6STAT_INC(icp6s_outhist[ICMP6_WRUREPLY]); 711 icmp6_reflect(n, noff); 712 } 713 break; 714 } 715 716 case ICMP6_WRUREPLY: 717 if (code != 0) 718 goto badcode; 719 break; 720 721 case ND_ROUTER_SOLICIT: 722 icmp6_ifstat_inc(ifp, ifs6_in_routersolicit); 723 if (code != 0) 724 goto badcode; 725 if (icmp6len < sizeof(struct nd_router_solicit)) 726 goto badlen; 727 if (send_sendso_input_hook != NULL) { 728 m = m_pullup(m, off + icmp6len); 729 if (m == NULL) { 730 IP6STAT_INC(ip6s_exthdrtoolong); 731 *mp = NULL; 732 return (IPPROTO_DONE); 733 } 734 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 735 if (error == 0) { 736 m = NULL; 737 goto freeit; 738 } 739 } 740 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 741 nd6_rs_input(m, off, icmp6len); 742 m = n; 743 if (m == NULL) 744 goto freeit; 745 break; 746 747 case ND_ROUTER_ADVERT: 748 icmp6_ifstat_inc(ifp, ifs6_in_routeradvert); 749 if (code != 0) 750 goto badcode; 751 if (icmp6len < sizeof(struct nd_router_advert)) 752 goto badlen; 753 if (send_sendso_input_hook != NULL) { 754 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 755 if (error == 0) { 756 m = NULL; 757 goto freeit; 758 } 759 } 760 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 761 nd6_ra_input(m, off, icmp6len); 762 m = n; 763 if (m == NULL) 764 goto freeit; 765 break; 766 767 case ND_NEIGHBOR_SOLICIT: 768 icmp6_ifstat_inc(ifp, ifs6_in_neighborsolicit); 769 if (code != 0) 770 goto badcode; 771 if (icmp6len < sizeof(struct nd_neighbor_solicit)) 772 goto badlen; 773 if (send_sendso_input_hook != NULL) { 774 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 775 if (error == 0) { 776 m = NULL; 777 goto freeit; 778 } 779 } 780 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 781 nd6_ns_input(m, off, icmp6len); 782 m = n; 783 if (m == NULL) 784 goto freeit; 785 break; 786 787 case ND_NEIGHBOR_ADVERT: 788 icmp6_ifstat_inc(ifp, ifs6_in_neighboradvert); 789 if (code != 0) 790 goto badcode; 791 if (icmp6len < sizeof(struct nd_neighbor_advert)) 792 goto badlen; 793 if (send_sendso_input_hook != NULL) { 794 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 795 if (error == 0) { 796 m = NULL; 797 goto freeit; 798 } 799 } 800 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 801 nd6_na_input(m, off, icmp6len); 802 m = n; 803 if (m == NULL) 804 goto freeit; 805 break; 806 807 case ND_REDIRECT: 808 icmp6_ifstat_inc(ifp, ifs6_in_redirect); 809 if (code != 0) 810 goto badcode; 811 if (icmp6len < sizeof(struct nd_redirect)) 812 goto badlen; 813 if (send_sendso_input_hook != NULL) { 814 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 815 if (error == 0) { 816 m = NULL; 817 goto freeit; 818 } 819 } 820 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 821 icmp6_redirect_input(m, off); 822 m = n; 823 if (m == NULL) 824 goto freeit; 825 break; 826 827 case ICMP6_ROUTER_RENUMBERING: 828 if (code != ICMP6_ROUTER_RENUMBERING_COMMAND && 829 code != ICMP6_ROUTER_RENUMBERING_RESULT) 830 goto badcode; 831 if (icmp6len < sizeof(struct icmp6_router_renum)) 832 goto badlen; 833 break; 834 835 default: 836 nd6log((LOG_DEBUG, 837 "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n", 838 icmp6->icmp6_type, ip6_sprintf(ip6bufs, &ip6->ip6_src), 839 ip6_sprintf(ip6bufd, &ip6->ip6_dst), 840 ifp ? ifp->if_index : 0)); 841 if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) { 842 /* ICMPv6 error: MUST deliver it by spec... */ 843 code = PRC_NCMDS; 844 /* deliver */ 845 } else { 846 /* ICMPv6 informational: MUST not deliver */ 847 break; 848 } 849 deliver: 850 if (icmp6_notify_error(&m, off, icmp6len, code) != 0) { 851 /* In this case, m should've been freed. */ 852 *mp = NULL; 853 return (IPPROTO_DONE); 854 } 855 break; 856 857 badcode: 858 ICMP6STAT_INC(icp6s_badcode); 859 break; 860 861 badlen: 862 ICMP6STAT_INC(icp6s_badlen); 863 break; 864 } 865 866 /* deliver the packet to appropriate sockets */ 867 icmp6_rip6_input(&m, *offp); 868 869 *mp = m; 870 return (IPPROTO_DONE); 871 872 freeit: 873 m_freem(m); 874 *mp = NULL; 875 return (IPPROTO_DONE); 876 } 877 878 static int 879 icmp6_notify_error(struct mbuf **mp, int off, int icmp6len, int code) 880 { 881 struct mbuf *m; 882 struct icmp6_hdr *icmp6; 883 struct ip6_hdr *eip6; 884 u_int32_t notifymtu; 885 struct sockaddr_in6 icmp6src, icmp6dst; 886 887 m = *mp; 888 889 if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) { 890 ICMP6STAT_INC(icp6s_tooshort); 891 goto freeit; 892 } 893 894 m = m_pullup(m, off + sizeof(*icmp6) + sizeof(struct ip6_hdr)); 895 if (m == NULL) { 896 IP6STAT_INC(ip6s_exthdrtoolong); 897 *mp = m; 898 return (-1); 899 } 900 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 901 eip6 = (struct ip6_hdr *)(icmp6 + 1); 902 903 /* Detect the upper level protocol */ 904 { 905 void (*ctlfunc)(int, struct sockaddr *, void *); 906 u_int8_t nxt = eip6->ip6_nxt; 907 int eoff = off + sizeof(struct icmp6_hdr) + 908 sizeof(struct ip6_hdr); 909 struct ip6ctlparam ip6cp; 910 struct in6_addr *finaldst = NULL; 911 int icmp6type = icmp6->icmp6_type; 912 struct ip6_frag *fh; 913 struct ip6_rthdr *rth; 914 struct ip6_rthdr0 *rth0; 915 int rthlen; 916 917 while (1) { /* XXX: should avoid infinite loop explicitly? */ 918 struct ip6_ext *eh; 919 920 switch (nxt) { 921 case IPPROTO_HOPOPTS: 922 case IPPROTO_DSTOPTS: 923 case IPPROTO_AH: 924 m = m_pullup(m, eoff + sizeof(struct ip6_ext)); 925 if (m == NULL) { 926 IP6STAT_INC(ip6s_exthdrtoolong); 927 *mp = m; 928 return (-1); 929 } 930 eh = (struct ip6_ext *) 931 (mtod(m, caddr_t) + eoff); 932 if (nxt == IPPROTO_AH) 933 eoff += (eh->ip6e_len + 2) << 2; 934 else 935 eoff += (eh->ip6e_len + 1) << 3; 936 nxt = eh->ip6e_nxt; 937 break; 938 case IPPROTO_ROUTING: 939 /* 940 * When the erroneous packet contains a 941 * routing header, we should examine the 942 * header to determine the final destination. 943 * Otherwise, we can't properly update 944 * information that depends on the final 945 * destination (e.g. path MTU). 946 */ 947 m = m_pullup(m, eoff + sizeof(*rth)); 948 if (m == NULL) { 949 IP6STAT_INC(ip6s_exthdrtoolong); 950 *mp = m; 951 return (-1); 952 } 953 rth = (struct ip6_rthdr *) 954 (mtod(m, caddr_t) + eoff); 955 rthlen = (rth->ip6r_len + 1) << 3; 956 /* 957 * XXX: currently there is no 958 * officially defined type other 959 * than type-0. 960 * Note that if the segment left field 961 * is 0, all intermediate hops must 962 * have been passed. 963 */ 964 if (rth->ip6r_segleft && 965 rth->ip6r_type == IPV6_RTHDR_TYPE_0) { 966 int hops; 967 968 m = m_pullup(m, eoff + rthlen); 969 if (m == NULL) { 970 IP6STAT_INC(ip6s_exthdrtoolong); 971 *mp = m; 972 return (-1); 973 } 974 rth0 = (struct ip6_rthdr0 *) 975 (mtod(m, caddr_t) + eoff); 976 /* just ignore a bogus header */ 977 if ((rth0->ip6r0_len % 2) == 0 && 978 (hops = rth0->ip6r0_len/2)) 979 finaldst = (struct in6_addr *)(rth0 + 1) + (hops - 1); 980 } 981 eoff += rthlen; 982 nxt = rth->ip6r_nxt; 983 break; 984 case IPPROTO_FRAGMENT: 985 m = m_pullup(m, eoff + sizeof(struct ip6_frag)); 986 if (m == NULL) { 987 IP6STAT_INC(ip6s_exthdrtoolong); 988 *mp = m; 989 return (-1); 990 } 991 fh = (struct ip6_frag *)(mtod(m, caddr_t) + 992 eoff); 993 /* 994 * Data after a fragment header is meaningless 995 * unless it is the first fragment, but 996 * we'll go to the notify label for path MTU 997 * discovery. 998 */ 999 if (fh->ip6f_offlg & IP6F_OFF_MASK) 1000 goto notify; 1001 1002 eoff += sizeof(struct ip6_frag); 1003 nxt = fh->ip6f_nxt; 1004 break; 1005 default: 1006 /* 1007 * This case includes ESP and the No Next 1008 * Header. In such cases going to the notify 1009 * label does not have any meaning 1010 * (i.e. ctlfunc will be NULL), but we go 1011 * anyway since we might have to update 1012 * path MTU information. 1013 */ 1014 goto notify; 1015 } 1016 } 1017 notify: 1018 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 1019 1020 /* 1021 * retrieve parameters from the inner IPv6 header, and convert 1022 * them into sockaddr structures. 1023 * XXX: there is no guarantee that the source or destination 1024 * addresses of the inner packet are in the same scope as 1025 * the addresses of the icmp packet. But there is no other 1026 * way to determine the zone. 1027 */ 1028 eip6 = (struct ip6_hdr *)(icmp6 + 1); 1029 1030 bzero(&icmp6dst, sizeof(icmp6dst)); 1031 icmp6dst.sin6_len = sizeof(struct sockaddr_in6); 1032 icmp6dst.sin6_family = AF_INET6; 1033 if (finaldst == NULL) 1034 icmp6dst.sin6_addr = eip6->ip6_dst; 1035 else 1036 icmp6dst.sin6_addr = *finaldst; 1037 if (in6_setscope(&icmp6dst.sin6_addr, m->m_pkthdr.rcvif, NULL)) 1038 goto freeit; 1039 bzero(&icmp6src, sizeof(icmp6src)); 1040 icmp6src.sin6_len = sizeof(struct sockaddr_in6); 1041 icmp6src.sin6_family = AF_INET6; 1042 icmp6src.sin6_addr = eip6->ip6_src; 1043 if (in6_setscope(&icmp6src.sin6_addr, m->m_pkthdr.rcvif, NULL)) 1044 goto freeit; 1045 icmp6src.sin6_flowinfo = 1046 (eip6->ip6_flow & IPV6_FLOWLABEL_MASK); 1047 1048 if (finaldst == NULL) 1049 finaldst = &eip6->ip6_dst; 1050 ip6cp.ip6c_m = m; 1051 ip6cp.ip6c_icmp6 = icmp6; 1052 ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1); 1053 ip6cp.ip6c_off = eoff; 1054 ip6cp.ip6c_finaldst = finaldst; 1055 ip6cp.ip6c_src = &icmp6src; 1056 ip6cp.ip6c_nxt = nxt; 1057 1058 if (icmp6type == ICMP6_PACKET_TOO_BIG) { 1059 notifymtu = ntohl(icmp6->icmp6_mtu); 1060 ip6cp.ip6c_cmdarg = (void *)¬ifymtu; 1061 icmp6_mtudisc_update(&ip6cp, 1); /*XXX*/ 1062 } 1063 1064 ctlfunc = (void (*)(int, struct sockaddr *, void *)) 1065 (inet6sw[ip6_protox[nxt]].pr_ctlinput); 1066 if (ctlfunc) { 1067 (void) (*ctlfunc)(code, (struct sockaddr *)&icmp6dst, 1068 &ip6cp); 1069 } 1070 } 1071 *mp = m; 1072 return (0); 1073 1074 freeit: 1075 m_freem(m); 1076 *mp = NULL; 1077 return (-1); 1078 } 1079 1080 void 1081 icmp6_mtudisc_update(struct ip6ctlparam *ip6cp, int validated) 1082 { 1083 struct in6_addr *dst = ip6cp->ip6c_finaldst; 1084 struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6; 1085 struct mbuf *m = ip6cp->ip6c_m; /* will be necessary for scope issue */ 1086 u_int mtu = ntohl(icmp6->icmp6_mtu); 1087 struct in_conninfo inc; 1088 1089 #if 0 1090 /* 1091 * RFC2460 section 5, last paragraph. 1092 * even though minimum link MTU for IPv6 is IPV6_MMTU, 1093 * we may see ICMPv6 too big with mtu < IPV6_MMTU 1094 * due to packet translator in the middle. 1095 * see ip6_output() and ip6_getpmtu() "alwaysfrag" case for 1096 * special handling. 1097 */ 1098 if (mtu < IPV6_MMTU) 1099 return; 1100 #endif 1101 1102 /* 1103 * we reject ICMPv6 too big with abnormally small value. 1104 * XXX what is the good definition of "abnormally small"? 1105 */ 1106 if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8) 1107 return; 1108 1109 if (!validated) 1110 return; 1111 1112 /* 1113 * In case the suggested mtu is less than IPV6_MMTU, we 1114 * only need to remember that it was for above mentioned 1115 * "alwaysfrag" case. 1116 * Try to be as close to the spec as possible. 1117 */ 1118 if (mtu < IPV6_MMTU) 1119 mtu = IPV6_MMTU - 8; 1120 1121 bzero(&inc, sizeof(inc)); 1122 inc.inc_fibnum = M_GETFIB(m); 1123 inc.inc_flags |= INC_ISIPV6; 1124 inc.inc6_faddr = *dst; 1125 if (in6_setscope(&inc.inc6_faddr, m->m_pkthdr.rcvif, NULL)) 1126 return; 1127 1128 if (mtu < tcp_maxmtu6(&inc, NULL)) { 1129 tcp_hc_updatemtu(&inc, mtu); 1130 ICMP6STAT_INC(icp6s_pmtuchg); 1131 } 1132 } 1133 1134 /* 1135 * Process a Node Information Query packet, based on 1136 * draft-ietf-ipngwg-icmp-name-lookups-07. 1137 * 1138 * Spec incompatibilities: 1139 * - IPv6 Subject address handling 1140 * - IPv4 Subject address handling support missing 1141 * - Proxy reply (answer even if it's not for me) 1142 * - joins NI group address at in6_ifattach() time only, does not cope 1143 * with hostname changes by sethostname(3) 1144 */ 1145 static struct mbuf * 1146 ni6_input(struct mbuf *m, int off, struct prison *pr) 1147 { 1148 struct icmp6_nodeinfo *ni6, *nni6; 1149 struct mbuf *n = NULL; 1150 u_int16_t qtype; 1151 int subjlen; 1152 int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); 1153 struct ni_reply_fqdn *fqdn; 1154 int addrs; /* for NI_QTYPE_NODEADDR */ 1155 struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */ 1156 struct in6_addr in6_subj; /* subject address */ 1157 struct ip6_hdr *ip6; 1158 int oldfqdn = 0; /* if 1, return pascal string (03 draft) */ 1159 char *subj = NULL; 1160 struct in6_ifaddr *ia6 = NULL; 1161 1162 ip6 = mtod(m, struct ip6_hdr *); 1163 ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off); 1164 1165 /* 1166 * Validate IPv6 source address. 1167 * The default configuration MUST be to refuse answering queries from 1168 * global-scope addresses according to RFC4602. 1169 * Notes: 1170 * - it's not very clear what "refuse" means; this implementation 1171 * simply drops it. 1172 * - it's not very easy to identify global-scope (unicast) addresses 1173 * since there are many prefixes for them. It should be safer 1174 * and in practice sufficient to check "all" but loopback and 1175 * link-local (note that site-local unicast was deprecated and 1176 * ULA is defined as global scope-wise) 1177 */ 1178 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_GLOBALOK) == 0 && 1179 !IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) && 1180 !IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) 1181 goto bad; 1182 1183 /* 1184 * Validate IPv6 destination address. 1185 * 1186 * The Responder must discard the Query without further processing 1187 * unless it is one of the Responder's unicast or anycast addresses, or 1188 * a link-local scope multicast address which the Responder has joined. 1189 * [RFC4602, Section 5.] 1190 */ 1191 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 1192 if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst)) 1193 goto bad; 1194 /* else it's a link-local multicast, fine */ 1195 } else { /* unicast or anycast */ 1196 ia6 = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */); 1197 if (ia6 == NULL) 1198 goto bad; /* XXX impossible */ 1199 1200 if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) && 1201 !(V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK)) { 1202 ifa_free(&ia6->ia_ifa); 1203 nd6log((LOG_DEBUG, "ni6_input: ignore node info to " 1204 "a temporary address in %s:%d", 1205 __FILE__, __LINE__)); 1206 goto bad; 1207 } 1208 ifa_free(&ia6->ia_ifa); 1209 } 1210 1211 /* validate query Subject field. */ 1212 qtype = ntohs(ni6->ni_qtype); 1213 subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo); 1214 switch (qtype) { 1215 case NI_QTYPE_NOOP: 1216 case NI_QTYPE_SUPTYPES: 1217 /* 07 draft */ 1218 if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0) 1219 break; 1220 /* FALLTHROUGH */ 1221 case NI_QTYPE_FQDN: 1222 case NI_QTYPE_NODEADDR: 1223 case NI_QTYPE_IPV4ADDR: 1224 switch (ni6->ni_code) { 1225 case ICMP6_NI_SUBJ_IPV6: 1226 #if ICMP6_NI_SUBJ_IPV6 != 0 1227 case 0: 1228 #endif 1229 /* 1230 * backward compatibility - try to accept 03 draft 1231 * format, where no Subject is present. 1232 */ 1233 if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 && 1234 subjlen == 0) { 1235 oldfqdn++; 1236 break; 1237 } 1238 #if ICMP6_NI_SUBJ_IPV6 != 0 1239 if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6) 1240 goto bad; 1241 #endif 1242 1243 if (subjlen != sizeof(struct in6_addr)) 1244 goto bad; 1245 1246 /* 1247 * Validate Subject address. 1248 * 1249 * Not sure what exactly "address belongs to the node" 1250 * means in the spec, is it just unicast, or what? 1251 * 1252 * At this moment we consider Subject address as 1253 * "belong to the node" if the Subject address equals 1254 * to the IPv6 destination address; validation for 1255 * IPv6 destination address should have done enough 1256 * check for us. 1257 * 1258 * We do not do proxy at this moment. 1259 */ 1260 m_copydata(m, off + sizeof(struct icmp6_nodeinfo), 1261 subjlen, (caddr_t)&in6_subj); 1262 if (in6_setscope(&in6_subj, m->m_pkthdr.rcvif, NULL)) 1263 goto bad; 1264 1265 subj = (char *)&in6_subj; 1266 if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &in6_subj)) 1267 break; 1268 1269 /* 1270 * XXX if we are to allow other cases, we should really 1271 * be careful about scope here. 1272 * basically, we should disallow queries toward IPv6 1273 * destination X with subject Y, 1274 * if scope(X) > scope(Y). 1275 * if we allow scope(X) > scope(Y), it will result in 1276 * information leakage across scope boundary. 1277 */ 1278 goto bad; 1279 1280 case ICMP6_NI_SUBJ_FQDN: 1281 /* 1282 * Validate Subject name with gethostname(3). 1283 * 1284 * The behavior may need some debate, since: 1285 * - we are not sure if the node has FQDN as 1286 * hostname (returned by gethostname(3)). 1287 * - the code does wildcard match for truncated names. 1288 * however, we are not sure if we want to perform 1289 * wildcard match, if gethostname(3) side has 1290 * truncated hostname. 1291 */ 1292 mtx_lock(&pr->pr_mtx); 1293 n = ni6_nametodns(pr->pr_hostname, 1294 strlen(pr->pr_hostname), 0); 1295 mtx_unlock(&pr->pr_mtx); 1296 if (!n || n->m_next || n->m_len == 0) 1297 goto bad; 1298 m = m_pullup(m, off + sizeof(struct icmp6_nodeinfo) + 1299 subjlen); 1300 if (m == NULL) { 1301 IP6STAT_INC(ip6s_exthdrtoolong); 1302 goto bad; 1303 } 1304 /* ip6 possibly invalid but not used after. */ 1305 ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off); 1306 subj = (char *)(mtod(m, caddr_t) + off + 1307 sizeof(struct icmp6_nodeinfo)); 1308 if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *), 1309 n->m_len)) { 1310 goto bad; 1311 } 1312 m_freem(n); 1313 n = NULL; 1314 break; 1315 1316 case ICMP6_NI_SUBJ_IPV4: /* XXX: to be implemented? */ 1317 default: 1318 goto bad; 1319 } 1320 break; 1321 } 1322 1323 /* refuse based on configuration. XXX ICMP6_NI_REFUSED? */ 1324 switch (qtype) { 1325 case NI_QTYPE_FQDN: 1326 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_FQDNOK) == 0) 1327 goto bad; 1328 break; 1329 case NI_QTYPE_NODEADDR: 1330 case NI_QTYPE_IPV4ADDR: 1331 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_NODEADDROK) == 0) 1332 goto bad; 1333 break; 1334 } 1335 1336 /* guess reply length */ 1337 switch (qtype) { 1338 case NI_QTYPE_NOOP: 1339 break; /* no reply data */ 1340 case NI_QTYPE_SUPTYPES: 1341 replylen += sizeof(u_int32_t); 1342 break; 1343 case NI_QTYPE_FQDN: 1344 /* XXX will append an mbuf */ 1345 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); 1346 break; 1347 case NI_QTYPE_NODEADDR: 1348 addrs = ni6_addrs(ni6, m, &ifp, (struct in6_addr *)subj); 1349 if ((replylen += addrs * (sizeof(struct in6_addr) + 1350 sizeof(u_int32_t))) > MCLBYTES) 1351 replylen = MCLBYTES; /* XXX: will truncate pkt later */ 1352 break; 1353 case NI_QTYPE_IPV4ADDR: 1354 /* unsupported - should respond with unknown Qtype? */ 1355 break; 1356 default: 1357 /* 1358 * XXX: We must return a reply with the ICMP6 code 1359 * `unknown Qtype' in this case. However we regard the case 1360 * as an FQDN query for backward compatibility. 1361 * Older versions set a random value to this field, 1362 * so it rarely varies in the defined qtypes. 1363 * But the mechanism is not reliable... 1364 * maybe we should obsolete older versions. 1365 */ 1366 qtype = NI_QTYPE_FQDN; 1367 /* XXX will append an mbuf */ 1368 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); 1369 oldfqdn++; 1370 break; 1371 } 1372 1373 /* Allocate an mbuf to reply. */ 1374 if (replylen > MCLBYTES) { 1375 /* 1376 * XXX: should we try to allocate more? But MCLBYTES 1377 * is probably much larger than IPV6_MMTU... 1378 */ 1379 goto bad; 1380 } 1381 if (replylen > MHLEN) 1382 n = m_getcl(M_NOWAIT, m->m_type, M_PKTHDR); 1383 else 1384 n = m_gethdr(M_NOWAIT, m->m_type); 1385 if (n == NULL) { 1386 m_freem(m); 1387 return (NULL); 1388 } 1389 m_move_pkthdr(n, m); /* just for recvif and FIB */ 1390 n->m_pkthdr.len = n->m_len = replylen; 1391 1392 /* copy mbuf header and IPv6 + Node Information base headers */ 1393 bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr)); 1394 nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1); 1395 bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo)); 1396 1397 /* qtype dependent procedure */ 1398 switch (qtype) { 1399 case NI_QTYPE_NOOP: 1400 nni6->ni_code = ICMP6_NI_SUCCESS; 1401 nni6->ni_flags = 0; 1402 break; 1403 case NI_QTYPE_SUPTYPES: 1404 { 1405 u_int32_t v; 1406 nni6->ni_code = ICMP6_NI_SUCCESS; 1407 nni6->ni_flags = htons(0x0000); /* raw bitmap */ 1408 /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */ 1409 v = (u_int32_t)htonl(0x0000000f); 1410 bcopy(&v, nni6 + 1, sizeof(u_int32_t)); 1411 break; 1412 } 1413 case NI_QTYPE_FQDN: 1414 nni6->ni_code = ICMP6_NI_SUCCESS; 1415 fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) + 1416 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo)); 1417 nni6->ni_flags = 0; /* XXX: meaningless TTL */ 1418 fqdn->ni_fqdn_ttl = 0; /* ditto. */ 1419 /* 1420 * XXX do we really have FQDN in hostname? 1421 */ 1422 mtx_lock(&pr->pr_mtx); 1423 n->m_next = ni6_nametodns(pr->pr_hostname, 1424 strlen(pr->pr_hostname), oldfqdn); 1425 mtx_unlock(&pr->pr_mtx); 1426 if (n->m_next == NULL) 1427 goto bad; 1428 /* XXX we assume that n->m_next is not a chain */ 1429 if (n->m_next->m_next != NULL) 1430 goto bad; 1431 n->m_pkthdr.len += n->m_next->m_len; 1432 break; 1433 case NI_QTYPE_NODEADDR: 1434 { 1435 int lenlim, copied; 1436 1437 nni6->ni_code = ICMP6_NI_SUCCESS; 1438 n->m_pkthdr.len = n->m_len = 1439 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); 1440 lenlim = M_TRAILINGSPACE(n); 1441 copied = ni6_store_addrs(ni6, nni6, ifp, lenlim); 1442 /* XXX: reset mbuf length */ 1443 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + 1444 sizeof(struct icmp6_nodeinfo) + copied; 1445 break; 1446 } 1447 default: 1448 break; /* XXX impossible! */ 1449 } 1450 1451 nni6->ni_type = ICMP6_NI_REPLY; 1452 m_freem(m); 1453 return (n); 1454 1455 bad: 1456 m_freem(m); 1457 if (n) 1458 m_freem(n); 1459 return (NULL); 1460 } 1461 1462 /* 1463 * make a mbuf with DNS-encoded string. no compression support. 1464 * 1465 * XXX names with less than 2 dots (like "foo" or "foo.section") will be 1466 * treated as truncated name (two \0 at the end). this is a wild guess. 1467 * 1468 * old - return pascal string if non-zero 1469 */ 1470 static struct mbuf * 1471 ni6_nametodns(const char *name, int namelen, int old) 1472 { 1473 struct mbuf *m; 1474 char *cp, *ep; 1475 const char *p, *q; 1476 int i, len, nterm; 1477 1478 if (old) 1479 len = namelen + 1; 1480 else 1481 len = MCLBYTES; 1482 1483 /* Because MAXHOSTNAMELEN is usually 256, we use cluster mbuf. */ 1484 if (len > MLEN) 1485 m = m_getcl(M_NOWAIT, MT_DATA, 0); 1486 else 1487 m = m_get(M_NOWAIT, MT_DATA); 1488 if (m == NULL) 1489 goto fail; 1490 1491 if (old) { 1492 m->m_len = len; 1493 *mtod(m, char *) = namelen; 1494 bcopy(name, mtod(m, char *) + 1, namelen); 1495 return m; 1496 } else { 1497 m->m_len = 0; 1498 cp = mtod(m, char *); 1499 ep = mtod(m, char *) + M_TRAILINGSPACE(m); 1500 1501 /* if not certain about my name, return empty buffer */ 1502 if (namelen == 0) 1503 return m; 1504 1505 /* 1506 * guess if it looks like shortened hostname, or FQDN. 1507 * shortened hostname needs two trailing "\0". 1508 */ 1509 i = 0; 1510 for (p = name; p < name + namelen; p++) { 1511 if (*p && *p == '.') 1512 i++; 1513 } 1514 if (i < 2) 1515 nterm = 2; 1516 else 1517 nterm = 1; 1518 1519 p = name; 1520 while (cp < ep && p < name + namelen) { 1521 i = 0; 1522 for (q = p; q < name + namelen && *q && *q != '.'; q++) 1523 i++; 1524 /* result does not fit into mbuf */ 1525 if (cp + i + 1 >= ep) 1526 goto fail; 1527 /* 1528 * DNS label length restriction, RFC1035 page 8. 1529 * "i == 0" case is included here to avoid returning 1530 * 0-length label on "foo..bar". 1531 */ 1532 if (i <= 0 || i >= 64) 1533 goto fail; 1534 *cp++ = i; 1535 bcopy(p, cp, i); 1536 cp += i; 1537 p = q; 1538 if (p < name + namelen && *p == '.') 1539 p++; 1540 } 1541 /* termination */ 1542 if (cp + nterm >= ep) 1543 goto fail; 1544 while (nterm-- > 0) 1545 *cp++ = '\0'; 1546 m->m_len = cp - mtod(m, char *); 1547 return m; 1548 } 1549 1550 panic("should not reach here"); 1551 /* NOTREACHED */ 1552 1553 fail: 1554 if (m) 1555 m_freem(m); 1556 return NULL; 1557 } 1558 1559 /* 1560 * check if two DNS-encoded string matches. takes care of truncated 1561 * form (with \0\0 at the end). no compression support. 1562 * XXX upper/lowercase match (see RFC2065) 1563 */ 1564 static int 1565 ni6_dnsmatch(const char *a, int alen, const char *b, int blen) 1566 { 1567 const char *a0, *b0; 1568 int l; 1569 1570 /* simplest case - need validation? */ 1571 if (alen == blen && bcmp(a, b, alen) == 0) 1572 return 1; 1573 1574 a0 = a; 1575 b0 = b; 1576 1577 /* termination is mandatory */ 1578 if (alen < 2 || blen < 2) 1579 return 0; 1580 if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0') 1581 return 0; 1582 alen--; 1583 blen--; 1584 1585 while (a - a0 < alen && b - b0 < blen) { 1586 if (a - a0 + 1 > alen || b - b0 + 1 > blen) 1587 return 0; 1588 1589 if ((signed char)a[0] < 0 || (signed char)b[0] < 0) 1590 return 0; 1591 /* we don't support compression yet */ 1592 if (a[0] >= 64 || b[0] >= 64) 1593 return 0; 1594 1595 /* truncated case */ 1596 if (a[0] == 0 && a - a0 == alen - 1) 1597 return 1; 1598 if (b[0] == 0 && b - b0 == blen - 1) 1599 return 1; 1600 if (a[0] == 0 || b[0] == 0) 1601 return 0; 1602 1603 if (a[0] != b[0]) 1604 return 0; 1605 l = a[0]; 1606 if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen) 1607 return 0; 1608 if (bcmp(a + 1, b + 1, l) != 0) 1609 return 0; 1610 1611 a += 1 + l; 1612 b += 1 + l; 1613 } 1614 1615 if (a - a0 == alen && b - b0 == blen) 1616 return 1; 1617 else 1618 return 0; 1619 } 1620 1621 /* 1622 * calculate the number of addresses to be returned in the node info reply. 1623 */ 1624 static int 1625 ni6_addrs(struct icmp6_nodeinfo *ni6, struct mbuf *m, struct ifnet **ifpp, 1626 struct in6_addr *subj) 1627 { 1628 struct ifnet *ifp; 1629 struct in6_ifaddr *ifa6; 1630 struct ifaddr *ifa; 1631 int addrs = 0, addrsofif, iffound = 0; 1632 int niflags = ni6->ni_flags; 1633 1634 NET_EPOCH_ASSERT(); 1635 1636 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) { 1637 switch (ni6->ni_code) { 1638 case ICMP6_NI_SUBJ_IPV6: 1639 if (subj == NULL) /* must be impossible... */ 1640 return (0); 1641 break; 1642 default: 1643 /* 1644 * XXX: we only support IPv6 subject address for 1645 * this Qtype. 1646 */ 1647 return (0); 1648 } 1649 } 1650 1651 CK_STAILQ_FOREACH(ifp, &V_ifnet, if_link) { 1652 addrsofif = 0; 1653 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 1654 if (ifa->ifa_addr->sa_family != AF_INET6) 1655 continue; 1656 ifa6 = (struct in6_ifaddr *)ifa; 1657 1658 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 && 1659 IN6_ARE_ADDR_EQUAL(subj, &ifa6->ia_addr.sin6_addr)) 1660 iffound = 1; 1661 1662 /* 1663 * IPv4-mapped addresses can only be returned by a 1664 * Node Information proxy, since they represent 1665 * addresses of IPv4-only nodes, which perforce do 1666 * not implement this protocol. 1667 * [icmp-name-lookups-07, Section 5.4] 1668 * So we don't support NI_NODEADDR_FLAG_COMPAT in 1669 * this function at this moment. 1670 */ 1671 1672 /* What do we have to do about ::1? */ 1673 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { 1674 case IPV6_ADDR_SCOPE_LINKLOCAL: 1675 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) 1676 continue; 1677 break; 1678 case IPV6_ADDR_SCOPE_SITELOCAL: 1679 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) 1680 continue; 1681 break; 1682 case IPV6_ADDR_SCOPE_GLOBAL: 1683 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) 1684 continue; 1685 break; 1686 default: 1687 continue; 1688 } 1689 1690 /* 1691 * check if anycast is okay. 1692 * XXX: just experimental. not in the spec. 1693 */ 1694 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && 1695 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) 1696 continue; /* we need only unicast addresses */ 1697 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && 1698 (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) { 1699 continue; 1700 } 1701 addrsofif++; /* count the address */ 1702 } 1703 if (iffound) { 1704 *ifpp = ifp; 1705 return (addrsofif); 1706 } 1707 1708 addrs += addrsofif; 1709 } 1710 1711 return (addrs); 1712 } 1713 1714 static int 1715 ni6_store_addrs(struct icmp6_nodeinfo *ni6, struct icmp6_nodeinfo *nni6, 1716 struct ifnet *ifp0, int resid) 1717 { 1718 struct ifnet *ifp; 1719 struct in6_ifaddr *ifa6; 1720 struct ifaddr *ifa; 1721 struct ifnet *ifp_dep = NULL; 1722 int copied = 0, allow_deprecated = 0; 1723 u_char *cp = (u_char *)(nni6 + 1); 1724 int niflags = ni6->ni_flags; 1725 u_int32_t ltime; 1726 1727 NET_EPOCH_ASSERT(); 1728 1729 if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL)) 1730 return (0); /* needless to copy */ 1731 1732 ifp = ifp0 ? ifp0 : CK_STAILQ_FIRST(&V_ifnet); 1733 again: 1734 1735 for (; ifp; ifp = CK_STAILQ_NEXT(ifp, if_link)) { 1736 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 1737 if (ifa->ifa_addr->sa_family != AF_INET6) 1738 continue; 1739 ifa6 = (struct in6_ifaddr *)ifa; 1740 1741 if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 && 1742 allow_deprecated == 0) { 1743 /* 1744 * prefererred address should be put before 1745 * deprecated addresses. 1746 */ 1747 1748 /* record the interface for later search */ 1749 if (ifp_dep == NULL) 1750 ifp_dep = ifp; 1751 1752 continue; 1753 } else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 && 1754 allow_deprecated != 0) 1755 continue; /* we now collect deprecated addrs */ 1756 1757 /* What do we have to do about ::1? */ 1758 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { 1759 case IPV6_ADDR_SCOPE_LINKLOCAL: 1760 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) 1761 continue; 1762 break; 1763 case IPV6_ADDR_SCOPE_SITELOCAL: 1764 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) 1765 continue; 1766 break; 1767 case IPV6_ADDR_SCOPE_GLOBAL: 1768 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) 1769 continue; 1770 break; 1771 default: 1772 continue; 1773 } 1774 1775 /* 1776 * check if anycast is okay. 1777 * XXX: just experimental. not in the spec. 1778 */ 1779 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && 1780 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) 1781 continue; 1782 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && 1783 (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) { 1784 continue; 1785 } 1786 1787 /* now we can copy the address */ 1788 if (resid < sizeof(struct in6_addr) + 1789 sizeof(u_int32_t)) { 1790 /* 1791 * We give up much more copy. 1792 * Set the truncate flag and return. 1793 */ 1794 nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE; 1795 return (copied); 1796 } 1797 1798 /* 1799 * Set the TTL of the address. 1800 * The TTL value should be one of the following 1801 * according to the specification: 1802 * 1803 * 1. The remaining lifetime of a DHCP lease on the 1804 * address, or 1805 * 2. The remaining Valid Lifetime of a prefix from 1806 * which the address was derived through Stateless 1807 * Autoconfiguration. 1808 * 1809 * Note that we currently do not support stateful 1810 * address configuration by DHCPv6, so the former 1811 * case can't happen. 1812 */ 1813 if (ifa6->ia6_lifetime.ia6t_expire == 0) 1814 ltime = ND6_INFINITE_LIFETIME; 1815 else { 1816 if (ifa6->ia6_lifetime.ia6t_expire > 1817 time_uptime) 1818 ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_uptime); 1819 else 1820 ltime = 0; 1821 } 1822 1823 bcopy(<ime, cp, sizeof(u_int32_t)); 1824 cp += sizeof(u_int32_t); 1825 1826 /* copy the address itself */ 1827 bcopy(&ifa6->ia_addr.sin6_addr, cp, 1828 sizeof(struct in6_addr)); 1829 in6_clearscope((struct in6_addr *)cp); /* XXX */ 1830 cp += sizeof(struct in6_addr); 1831 1832 resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t)); 1833 copied += (sizeof(struct in6_addr) + sizeof(u_int32_t)); 1834 } 1835 if (ifp0) /* we need search only on the specified IF */ 1836 break; 1837 } 1838 1839 if (allow_deprecated == 0 && ifp_dep != NULL) { 1840 ifp = ifp_dep; 1841 allow_deprecated = 1; 1842 1843 goto again; 1844 } 1845 1846 return (copied); 1847 } 1848 1849 /* 1850 * XXX almost dup'ed code with rip6_input. 1851 */ 1852 static int 1853 icmp6_rip6_input(struct mbuf **mp, int off) 1854 { 1855 struct mbuf *m = *mp; 1856 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1857 struct inpcb *inp; 1858 struct inpcb *last = NULL; 1859 struct sockaddr_in6 fromsa; 1860 struct icmp6_hdr *icmp6; 1861 struct mbuf *opts = NULL; 1862 1863 NET_EPOCH_ASSERT(); 1864 1865 /* This is assumed to be safe; icmp6_input() does a pullup. */ 1866 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off); 1867 1868 /* 1869 * XXX: the address may have embedded scope zone ID, which should be 1870 * hidden from applications. 1871 */ 1872 bzero(&fromsa, sizeof(fromsa)); 1873 fromsa.sin6_family = AF_INET6; 1874 fromsa.sin6_len = sizeof(struct sockaddr_in6); 1875 fromsa.sin6_addr = ip6->ip6_src; 1876 if (sa6_recoverscope(&fromsa)) { 1877 m_freem(m); 1878 *mp = NULL; 1879 return (IPPROTO_DONE); 1880 } 1881 1882 CK_LIST_FOREACH(inp, &V_ripcb, inp_list) { 1883 if ((inp->inp_vflag & INP_IPV6) == 0) 1884 continue; 1885 if (inp->inp_ip_p != IPPROTO_ICMPV6) 1886 continue; 1887 if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr) && 1888 !IN6_ARE_ADDR_EQUAL(&inp->in6p_laddr, &ip6->ip6_dst)) 1889 continue; 1890 if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr) && 1891 !IN6_ARE_ADDR_EQUAL(&inp->in6p_faddr, &ip6->ip6_src)) 1892 continue; 1893 INP_RLOCK(inp); 1894 if (__predict_false(inp->inp_flags2 & INP_FREED)) { 1895 INP_RUNLOCK(inp); 1896 continue; 1897 } 1898 if (ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type, 1899 inp->in6p_icmp6filt)) { 1900 INP_RUNLOCK(inp); 1901 continue; 1902 } 1903 if (last != NULL) { 1904 struct mbuf *n = NULL; 1905 1906 /* 1907 * Recent network drivers tend to allocate a single 1908 * mbuf cluster, rather than to make a couple of 1909 * mbufs without clusters. Also, since the IPv6 code 1910 * path tries to avoid m_pullup(), it is highly 1911 * probable that we still have an mbuf cluster here 1912 * even though the necessary length can be stored in an 1913 * mbuf's internal buffer. 1914 * Meanwhile, the default size of the receive socket 1915 * buffer for raw sockets is not so large. This means 1916 * the possibility of packet loss is relatively higher 1917 * than before. To avoid this scenario, we copy the 1918 * received data to a separate mbuf that does not use 1919 * a cluster, if possible. 1920 * XXX: it is better to copy the data after stripping 1921 * intermediate headers. 1922 */ 1923 if ((m->m_flags & M_EXT) && m->m_next == NULL && 1924 m->m_len <= MHLEN) { 1925 n = m_get(M_NOWAIT, m->m_type); 1926 if (n != NULL) { 1927 if (m_dup_pkthdr(n, m, M_NOWAIT)) { 1928 bcopy(m->m_data, n->m_data, 1929 m->m_len); 1930 n->m_len = m->m_len; 1931 } else { 1932 m_free(n); 1933 n = NULL; 1934 } 1935 } 1936 } 1937 if (n != NULL || 1938 (n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) != NULL) { 1939 if (last->inp_flags & INP_CONTROLOPTS) 1940 ip6_savecontrol(last, n, &opts); 1941 /* strip intermediate headers */ 1942 m_adj(n, off); 1943 SOCKBUF_LOCK(&last->inp_socket->so_rcv); 1944 if (sbappendaddr_locked( 1945 &last->inp_socket->so_rcv, 1946 (struct sockaddr *)&fromsa, n, opts) 1947 == 0) { 1948 /* should notify about lost packet */ 1949 m_freem(n); 1950 if (opts) { 1951 m_freem(opts); 1952 } 1953 SOCKBUF_UNLOCK( 1954 &last->inp_socket->so_rcv); 1955 } else 1956 sorwakeup_locked(last->inp_socket); 1957 opts = NULL; 1958 } 1959 INP_RUNLOCK(last); 1960 } 1961 last = inp; 1962 } 1963 if (last != NULL) { 1964 if (last->inp_flags & INP_CONTROLOPTS) 1965 ip6_savecontrol(last, m, &opts); 1966 /* strip intermediate headers */ 1967 m_adj(m, off); 1968 1969 /* avoid using mbuf clusters if possible (see above) */ 1970 if ((m->m_flags & M_EXT) && m->m_next == NULL && 1971 m->m_len <= MHLEN) { 1972 struct mbuf *n; 1973 1974 n = m_get(M_NOWAIT, m->m_type); 1975 if (n != NULL) { 1976 if (m_dup_pkthdr(n, m, M_NOWAIT)) { 1977 bcopy(m->m_data, n->m_data, m->m_len); 1978 n->m_len = m->m_len; 1979 1980 m_freem(m); 1981 m = n; 1982 } else { 1983 m_freem(n); 1984 n = NULL; 1985 } 1986 } 1987 } 1988 SOCKBUF_LOCK(&last->inp_socket->so_rcv); 1989 if (sbappendaddr_locked(&last->inp_socket->so_rcv, 1990 (struct sockaddr *)&fromsa, m, opts) == 0) { 1991 m_freem(m); 1992 if (opts) 1993 m_freem(opts); 1994 SOCKBUF_UNLOCK(&last->inp_socket->so_rcv); 1995 } else 1996 sorwakeup_locked(last->inp_socket); 1997 INP_RUNLOCK(last); 1998 } else { 1999 m_freem(m); 2000 IP6STAT_DEC(ip6s_delivered); 2001 } 2002 *mp = NULL; 2003 return (IPPROTO_DONE); 2004 } 2005 2006 /* 2007 * Reflect the ip6 packet back to the source. 2008 * OFF points to the icmp6 header, counted from the top of the mbuf. 2009 */ 2010 void 2011 icmp6_reflect(struct mbuf *m, size_t off) 2012 { 2013 struct in6_addr src6, *srcp; 2014 struct ip6_hdr *ip6; 2015 struct icmp6_hdr *icmp6; 2016 struct in6_ifaddr *ia = NULL; 2017 struct ifnet *outif = NULL; 2018 int plen; 2019 int type, code, hlim; 2020 2021 /* too short to reflect */ 2022 if (off < sizeof(struct ip6_hdr)) { 2023 nd6log((LOG_DEBUG, 2024 "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n", 2025 (u_long)off, (u_long)sizeof(struct ip6_hdr), 2026 __FILE__, __LINE__)); 2027 goto bad; 2028 } 2029 2030 /* 2031 * If there are extra headers between IPv6 and ICMPv6, strip 2032 * off that header first. 2033 */ 2034 #ifdef DIAGNOSTIC 2035 if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN) 2036 panic("assumption failed in icmp6_reflect"); 2037 #endif 2038 if (off > sizeof(struct ip6_hdr)) { 2039 size_t l; 2040 struct ip6_hdr nip6; 2041 2042 l = off - sizeof(struct ip6_hdr); 2043 m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6); 2044 m_adj(m, l); 2045 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 2046 if (m->m_len < l) { 2047 if ((m = m_pullup(m, l)) == NULL) 2048 return; 2049 } 2050 bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6)); 2051 } else /* off == sizeof(struct ip6_hdr) */ { 2052 size_t l; 2053 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 2054 if (m->m_len < l) { 2055 if ((m = m_pullup(m, l)) == NULL) 2056 return; 2057 } 2058 } 2059 plen = m->m_pkthdr.len - sizeof(struct ip6_hdr); 2060 ip6 = mtod(m, struct ip6_hdr *); 2061 ip6->ip6_nxt = IPPROTO_ICMPV6; 2062 icmp6 = (struct icmp6_hdr *)(ip6 + 1); 2063 type = icmp6->icmp6_type; /* keep type for statistics */ 2064 code = icmp6->icmp6_code; /* ditto. */ 2065 hlim = 0; 2066 srcp = NULL; 2067 2068 /* 2069 * If the incoming packet was addressed directly to us (i.e. unicast), 2070 * use dst as the src for the reply. 2071 * The IN6_IFF_NOTREADY case should be VERY rare, but is possible 2072 * (for example) when we encounter an error while forwarding procedure 2073 * destined to a duplicated address of ours. 2074 */ 2075 if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 2076 ia = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */); 2077 if (ia != NULL && !(ia->ia6_flags & 2078 (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) { 2079 src6 = ia->ia_addr.sin6_addr; 2080 srcp = &src6; 2081 2082 if (m->m_pkthdr.rcvif != NULL) { 2083 /* XXX: This may not be the outgoing interface */ 2084 hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim; 2085 } else 2086 hlim = V_ip6_defhlim; 2087 } 2088 if (ia != NULL) 2089 ifa_free(&ia->ia_ifa); 2090 } 2091 2092 if (srcp == NULL) { 2093 int error; 2094 struct in6_addr dst6; 2095 uint32_t scopeid; 2096 2097 /* 2098 * This case matches to multicasts, our anycast, or unicasts 2099 * that we do not own. Select a source address based on the 2100 * source address of the erroneous packet. 2101 */ 2102 in6_splitscope(&ip6->ip6_src, &dst6, &scopeid); 2103 error = in6_selectsrc_addr(M_GETFIB(m), &dst6, 2104 scopeid, NULL, &src6, &hlim); 2105 2106 if (error) { 2107 char ip6buf[INET6_ADDRSTRLEN]; 2108 nd6log((LOG_DEBUG, 2109 "icmp6_reflect: source can't be determined: " 2110 "dst=%s, error=%d\n", 2111 ip6_sprintf(ip6buf, &ip6->ip6_dst), error)); 2112 goto bad; 2113 } 2114 srcp = &src6; 2115 } 2116 /* 2117 * ip6_input() drops a packet if its src is multicast. 2118 * So, the src is never multicast. 2119 */ 2120 ip6->ip6_dst = ip6->ip6_src; 2121 ip6->ip6_src = *srcp; 2122 ip6->ip6_flow = 0; 2123 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2124 ip6->ip6_vfc |= IPV6_VERSION; 2125 ip6->ip6_nxt = IPPROTO_ICMPV6; 2126 ip6->ip6_hlim = hlim; 2127 2128 icmp6->icmp6_cksum = 0; 2129 icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2130 sizeof(struct ip6_hdr), plen); 2131 2132 /* 2133 * XXX option handling 2134 */ 2135 2136 m->m_flags &= ~(M_BCAST|M_MCAST); 2137 m->m_pkthdr.rcvif = NULL; 2138 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2139 if (outif) 2140 icmp6_ifoutstat_inc(outif, type, code); 2141 2142 return; 2143 2144 bad: 2145 m_freem(m); 2146 return; 2147 } 2148 2149 void 2150 icmp6_fasttimo(void) 2151 { 2152 2153 mld_fasttimo(); 2154 } 2155 2156 void 2157 icmp6_slowtimo(void) 2158 { 2159 2160 mld_slowtimo(); 2161 } 2162 2163 static const char * 2164 icmp6_redirect_diag(struct in6_addr *src6, struct in6_addr *dst6, 2165 struct in6_addr *tgt6) 2166 { 2167 static char buf[1024]; 2168 char ip6bufs[INET6_ADDRSTRLEN]; 2169 char ip6bufd[INET6_ADDRSTRLEN]; 2170 char ip6buft[INET6_ADDRSTRLEN]; 2171 snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)", 2172 ip6_sprintf(ip6bufs, src6), ip6_sprintf(ip6bufd, dst6), 2173 ip6_sprintf(ip6buft, tgt6)); 2174 return buf; 2175 } 2176 2177 void 2178 icmp6_redirect_input(struct mbuf *m, int off) 2179 { 2180 struct ifnet *ifp; 2181 struct ip6_hdr *ip6; 2182 struct nd_redirect *nd_rd; 2183 struct in6_addr src6, redtgt6, reddst6; 2184 union nd_opts ndopts; 2185 char ip6buf[INET6_ADDRSTRLEN]; 2186 char *lladdr; 2187 int icmp6len, is_onlink, is_router, lladdrlen; 2188 2189 M_ASSERTPKTHDR(m); 2190 KASSERT(m->m_pkthdr.rcvif != NULL, ("%s: no rcvif", __func__)); 2191 2192 /* XXX if we are router, we don't update route by icmp6 redirect */ 2193 if (V_ip6_forwarding) 2194 goto freeit; 2195 if (!V_icmp6_rediraccept) 2196 goto freeit; 2197 2198 /* RFC 6980: Nodes MUST silently ignore fragments */ 2199 if(m->m_flags & M_FRAGMENTED) 2200 goto freeit; 2201 2202 ip6 = mtod(m, struct ip6_hdr *); 2203 icmp6len = ntohs(ip6->ip6_plen); 2204 m = m_pullup(m, off + icmp6len); 2205 if (m == NULL) { 2206 IP6STAT_INC(ip6s_exthdrtoolong); 2207 return; 2208 } 2209 ip6 = mtod(m, struct ip6_hdr *); 2210 nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off); 2211 2212 ifp = m->m_pkthdr.rcvif; 2213 redtgt6 = nd_rd->nd_rd_target; 2214 reddst6 = nd_rd->nd_rd_dst; 2215 2216 if (in6_setscope(&redtgt6, ifp, NULL) || 2217 in6_setscope(&reddst6, ifp, NULL)) { 2218 goto freeit; 2219 } 2220 2221 /* validation */ 2222 src6 = ip6->ip6_src; 2223 if (!IN6_IS_ADDR_LINKLOCAL(&src6)) { 2224 nd6log((LOG_ERR, 2225 "ICMP6 redirect sent from %s rejected; " 2226 "must be from linklocal\n", 2227 ip6_sprintf(ip6buf, &src6))); 2228 goto bad; 2229 } 2230 if (ip6->ip6_hlim != 255) { 2231 nd6log((LOG_ERR, 2232 "ICMP6 redirect sent from %s rejected; " 2233 "hlim=%d (must be 255)\n", 2234 ip6_sprintf(ip6buf, &src6), ip6->ip6_hlim)); 2235 goto bad; 2236 } 2237 { 2238 /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */ 2239 struct nhop6_basic nh6; 2240 struct in6_addr kdst; 2241 uint32_t scopeid; 2242 2243 in6_splitscope(&reddst6, &kdst, &scopeid); 2244 if (fib6_lookup_nh_basic(ifp->if_fib, &kdst, scopeid, 0, 0,&nh6)==0){ 2245 if ((nh6.nh_flags & NHF_GATEWAY) == 0) { 2246 nd6log((LOG_ERR, 2247 "ICMP6 redirect rejected; no route " 2248 "with inet6 gateway found for redirect dst: %s\n", 2249 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2250 goto bad; 2251 } 2252 2253 /* 2254 * Embed scope zone id into next hop address, since 2255 * fib6_lookup_nh_basic() returns address without embedded 2256 * scope zone id. 2257 */ 2258 if (in6_setscope(&nh6.nh_addr, m->m_pkthdr.rcvif, NULL)) 2259 goto freeit; 2260 2261 if (IN6_ARE_ADDR_EQUAL(&src6, &nh6.nh_addr) == 0) { 2262 nd6log((LOG_ERR, 2263 "ICMP6 redirect rejected; " 2264 "not equal to gw-for-src=%s (must be same): " 2265 "%s\n", 2266 ip6_sprintf(ip6buf, &nh6.nh_addr), 2267 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2268 goto bad; 2269 } 2270 } else { 2271 nd6log((LOG_ERR, 2272 "ICMP6 redirect rejected; " 2273 "no route found for redirect dst: %s\n", 2274 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2275 goto bad; 2276 } 2277 } 2278 if (IN6_IS_ADDR_MULTICAST(&reddst6)) { 2279 nd6log((LOG_ERR, 2280 "ICMP6 redirect rejected; " 2281 "redirect dst must be unicast: %s\n", 2282 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2283 goto bad; 2284 } 2285 2286 is_router = is_onlink = 0; 2287 if (IN6_IS_ADDR_LINKLOCAL(&redtgt6)) 2288 is_router = 1; /* router case */ 2289 if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0) 2290 is_onlink = 1; /* on-link destination case */ 2291 if (!is_router && !is_onlink) { 2292 nd6log((LOG_ERR, 2293 "ICMP6 redirect rejected; " 2294 "neither router case nor onlink case: %s\n", 2295 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2296 goto bad; 2297 } 2298 2299 icmp6len -= sizeof(*nd_rd); 2300 nd6_option_init(nd_rd + 1, icmp6len, &ndopts); 2301 if (nd6_options(&ndopts) < 0) { 2302 nd6log((LOG_INFO, "%s: invalid ND option, rejected: %s\n", 2303 __func__, icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2304 /* nd6_options have incremented stats */ 2305 goto freeit; 2306 } 2307 2308 lladdr = NULL; 2309 lladdrlen = 0; 2310 if (ndopts.nd_opts_tgt_lladdr) { 2311 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 2312 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 2313 } 2314 2315 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 2316 nd6log((LOG_INFO, "%s: lladdrlen mismatch for %s " 2317 "(if %d, icmp6 packet %d): %s\n", 2318 __func__, ip6_sprintf(ip6buf, &redtgt6), 2319 ifp->if_addrlen, lladdrlen - 2, 2320 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2321 goto bad; 2322 } 2323 2324 /* Validation passed. */ 2325 2326 /* RFC 2461 8.3 */ 2327 nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT, 2328 is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER); 2329 2330 /* 2331 * Install a gateway route in the better-router case or an interface 2332 * route in the on-link-destination case. 2333 */ 2334 { 2335 struct sockaddr_in6 sdst; 2336 struct sockaddr_in6 sgw; 2337 struct sockaddr_in6 ssrc; 2338 struct sockaddr *gw; 2339 int rt_flags; 2340 u_int fibnum; 2341 2342 bzero(&sdst, sizeof(sdst)); 2343 bzero(&ssrc, sizeof(ssrc)); 2344 sdst.sin6_family = ssrc.sin6_family = AF_INET6; 2345 sdst.sin6_len = ssrc.sin6_len = sizeof(struct sockaddr_in6); 2346 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr)); 2347 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr)); 2348 rt_flags = RTF_HOST; 2349 if (is_router) { 2350 bzero(&sgw, sizeof(sgw)); 2351 sgw.sin6_family = AF_INET6; 2352 sgw.sin6_len = sizeof(struct sockaddr_in6); 2353 bcopy(&redtgt6, &sgw.sin6_addr, 2354 sizeof(struct in6_addr)); 2355 gw = (struct sockaddr *)&sgw; 2356 rt_flags |= RTF_GATEWAY; 2357 } else 2358 gw = ifp->if_addr->ifa_addr; 2359 for (fibnum = 0; fibnum < rt_numfibs; fibnum++) 2360 in6_rtredirect((struct sockaddr *)&sdst, gw, 2361 (struct sockaddr *)NULL, rt_flags, 2362 (struct sockaddr *)&ssrc, fibnum); 2363 } 2364 /* finally update cached route in each socket via pfctlinput */ 2365 { 2366 struct sockaddr_in6 sdst; 2367 2368 bzero(&sdst, sizeof(sdst)); 2369 sdst.sin6_family = AF_INET6; 2370 sdst.sin6_len = sizeof(struct sockaddr_in6); 2371 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr)); 2372 pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst); 2373 } 2374 2375 freeit: 2376 m_freem(m); 2377 return; 2378 2379 bad: 2380 ICMP6STAT_INC(icp6s_badredirect); 2381 m_freem(m); 2382 } 2383 2384 void 2385 icmp6_redirect_output(struct mbuf *m0, struct rtentry *rt) 2386 { 2387 struct ifnet *ifp; /* my outgoing interface */ 2388 struct in6_addr *ifp_ll6; 2389 struct in6_addr *router_ll6; 2390 struct ip6_hdr *sip6; /* m0 as struct ip6_hdr */ 2391 struct mbuf *m = NULL; /* newly allocated one */ 2392 struct m_tag *mtag; 2393 struct ip6_hdr *ip6; /* m as struct ip6_hdr */ 2394 struct nd_redirect *nd_rd; 2395 struct llentry *ln = NULL; 2396 size_t maxlen; 2397 u_char *p; 2398 struct ifnet *outif = NULL; 2399 struct sockaddr_in6 src_sa; 2400 2401 icmp6_errcount(ND_REDIRECT, 0); 2402 2403 /* if we are not router, we don't send icmp6 redirect */ 2404 if (!V_ip6_forwarding) 2405 goto fail; 2406 2407 /* sanity check */ 2408 if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp)) 2409 goto fail; 2410 2411 /* 2412 * Address check: 2413 * the source address must identify a neighbor, and 2414 * the destination address must not be a multicast address 2415 * [RFC 2461, sec 8.2] 2416 */ 2417 sip6 = mtod(m0, struct ip6_hdr *); 2418 bzero(&src_sa, sizeof(src_sa)); 2419 src_sa.sin6_family = AF_INET6; 2420 src_sa.sin6_len = sizeof(src_sa); 2421 src_sa.sin6_addr = sip6->ip6_src; 2422 if (nd6_is_addr_neighbor(&src_sa, ifp) == 0) 2423 goto fail; 2424 if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst)) 2425 goto fail; /* what should we do here? */ 2426 2427 /* rate limit */ 2428 if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0)) 2429 goto fail; 2430 2431 /* 2432 * Since we are going to append up to 1280 bytes (= IPV6_MMTU), 2433 * we almost always ask for an mbuf cluster for simplicity. 2434 * (MHLEN < IPV6_MMTU is almost always true) 2435 */ 2436 #if IPV6_MMTU >= MCLBYTES 2437 # error assumption failed about IPV6_MMTU and MCLBYTES 2438 #endif 2439 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 2440 if (m == NULL) 2441 goto fail; 2442 M_SETFIB(m, rt->rt_fibnum); 2443 maxlen = M_TRAILINGSPACE(m); 2444 maxlen = min(IPV6_MMTU, maxlen); 2445 /* just for safety */ 2446 if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) + 2447 ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) { 2448 goto fail; 2449 } 2450 2451 { 2452 /* get ip6 linklocal address for ifp(my outgoing interface). */ 2453 struct in6_ifaddr *ia; 2454 if ((ia = in6ifa_ifpforlinklocal(ifp, 2455 IN6_IFF_NOTREADY| 2456 IN6_IFF_ANYCAST)) == NULL) 2457 goto fail; 2458 ifp_ll6 = &ia->ia_addr.sin6_addr; 2459 /* XXXRW: reference released prematurely. */ 2460 ifa_free(&ia->ia_ifa); 2461 } 2462 2463 /* get ip6 linklocal address for the router. */ 2464 if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) { 2465 struct sockaddr_in6 *sin6; 2466 sin6 = (struct sockaddr_in6 *)rt->rt_gateway; 2467 router_ll6 = &sin6->sin6_addr; 2468 if (!IN6_IS_ADDR_LINKLOCAL(router_ll6)) 2469 router_ll6 = (struct in6_addr *)NULL; 2470 } else 2471 router_ll6 = (struct in6_addr *)NULL; 2472 2473 /* ip6 */ 2474 ip6 = mtod(m, struct ip6_hdr *); 2475 ip6->ip6_flow = 0; 2476 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2477 ip6->ip6_vfc |= IPV6_VERSION; 2478 /* ip6->ip6_plen will be set later */ 2479 ip6->ip6_nxt = IPPROTO_ICMPV6; 2480 ip6->ip6_hlim = 255; 2481 /* ip6->ip6_src must be linklocal addr for my outgoing if. */ 2482 bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr)); 2483 bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr)); 2484 2485 /* ND Redirect */ 2486 nd_rd = (struct nd_redirect *)(ip6 + 1); 2487 nd_rd->nd_rd_type = ND_REDIRECT; 2488 nd_rd->nd_rd_code = 0; 2489 nd_rd->nd_rd_reserved = 0; 2490 if (rt->rt_flags & RTF_GATEWAY) { 2491 /* 2492 * nd_rd->nd_rd_target must be a link-local address in 2493 * better router cases. 2494 */ 2495 if (!router_ll6) 2496 goto fail; 2497 bcopy(router_ll6, &nd_rd->nd_rd_target, 2498 sizeof(nd_rd->nd_rd_target)); 2499 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2500 sizeof(nd_rd->nd_rd_dst)); 2501 } else { 2502 /* make sure redtgt == reddst */ 2503 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target, 2504 sizeof(nd_rd->nd_rd_target)); 2505 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2506 sizeof(nd_rd->nd_rd_dst)); 2507 } 2508 2509 p = (u_char *)(nd_rd + 1); 2510 2511 if (!router_ll6) 2512 goto nolladdropt; 2513 2514 { 2515 /* target lladdr option */ 2516 int len; 2517 struct nd_opt_hdr *nd_opt; 2518 char *lladdr; 2519 2520 ln = nd6_lookup(router_ll6, 0, ifp); 2521 if (ln == NULL) 2522 goto nolladdropt; 2523 2524 len = sizeof(*nd_opt) + ifp->if_addrlen; 2525 len = (len + 7) & ~7; /* round by 8 */ 2526 /* safety check */ 2527 if (len + (p - (u_char *)ip6) > maxlen) 2528 goto nolladdropt; 2529 2530 if (ln->la_flags & LLE_VALID) { 2531 nd_opt = (struct nd_opt_hdr *)p; 2532 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 2533 nd_opt->nd_opt_len = len >> 3; 2534 lladdr = (char *)(nd_opt + 1); 2535 bcopy(ln->ll_addr, lladdr, ifp->if_addrlen); 2536 p += len; 2537 } 2538 } 2539 nolladdropt: 2540 if (ln != NULL) 2541 LLE_RUNLOCK(ln); 2542 2543 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2544 2545 /* just to be safe */ 2546 #ifdef M_DECRYPTED /*not openbsd*/ 2547 if (m0->m_flags & M_DECRYPTED) 2548 goto noredhdropt; 2549 #endif 2550 if (p - (u_char *)ip6 > maxlen) 2551 goto noredhdropt; 2552 2553 { 2554 /* redirected header option */ 2555 int len; 2556 struct nd_opt_rd_hdr *nd_opt_rh; 2557 2558 /* 2559 * compute the maximum size for icmp6 redirect header option. 2560 * XXX room for auth header? 2561 */ 2562 len = maxlen - (p - (u_char *)ip6); 2563 len &= ~7; 2564 2565 /* This is just for simplicity. */ 2566 if (m0->m_pkthdr.len != m0->m_len) { 2567 if (m0->m_next) { 2568 m_freem(m0->m_next); 2569 m0->m_next = NULL; 2570 } 2571 m0->m_pkthdr.len = m0->m_len; 2572 } 2573 2574 /* 2575 * Redirected header option spec (RFC2461 4.6.3) talks nothing 2576 * about padding/truncate rule for the original IP packet. 2577 * From the discussion on IPv6imp in Feb 1999, 2578 * the consensus was: 2579 * - "attach as much as possible" is the goal 2580 * - pad if not aligned (original size can be guessed by 2581 * original ip6 header) 2582 * Following code adds the padding if it is simple enough, 2583 * and truncates if not. 2584 */ 2585 if (m0->m_next || m0->m_pkthdr.len != m0->m_len) 2586 panic("assumption failed in %s:%d", __FILE__, 2587 __LINE__); 2588 2589 if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) { 2590 /* not enough room, truncate */ 2591 m0->m_pkthdr.len = m0->m_len = len - 2592 sizeof(*nd_opt_rh); 2593 } else { 2594 /* enough room, pad or truncate */ 2595 size_t extra; 2596 2597 extra = m0->m_pkthdr.len % 8; 2598 if (extra) { 2599 /* pad if easy enough, truncate if not */ 2600 if (8 - extra <= M_TRAILINGSPACE(m0)) { 2601 /* pad */ 2602 m0->m_len += (8 - extra); 2603 m0->m_pkthdr.len += (8 - extra); 2604 } else { 2605 /* truncate */ 2606 m0->m_pkthdr.len -= extra; 2607 m0->m_len -= extra; 2608 } 2609 } 2610 len = m0->m_pkthdr.len + sizeof(*nd_opt_rh); 2611 m0->m_pkthdr.len = m0->m_len = len - 2612 sizeof(*nd_opt_rh); 2613 } 2614 2615 nd_opt_rh = (struct nd_opt_rd_hdr *)p; 2616 bzero(nd_opt_rh, sizeof(*nd_opt_rh)); 2617 nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER; 2618 nd_opt_rh->nd_opt_rh_len = len >> 3; 2619 p += sizeof(*nd_opt_rh); 2620 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2621 2622 /* connect m0 to m */ 2623 m_tag_delete_chain(m0, NULL); 2624 m0->m_flags &= ~M_PKTHDR; 2625 m->m_next = m0; 2626 m->m_pkthdr.len = m->m_len + m0->m_len; 2627 m0 = NULL; 2628 } 2629 noredhdropt:; 2630 if (m0) { 2631 m_freem(m0); 2632 m0 = NULL; 2633 } 2634 2635 /* XXX: clear embedded link IDs in the inner header */ 2636 in6_clearscope(&sip6->ip6_src); 2637 in6_clearscope(&sip6->ip6_dst); 2638 in6_clearscope(&nd_rd->nd_rd_target); 2639 in6_clearscope(&nd_rd->nd_rd_dst); 2640 2641 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr)); 2642 2643 nd_rd->nd_rd_cksum = 0; 2644 nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2645 sizeof(*ip6), ntohs(ip6->ip6_plen)); 2646 2647 if (send_sendso_input_hook != NULL) { 2648 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, sizeof(unsigned short), 2649 M_NOWAIT); 2650 if (mtag == NULL) 2651 goto fail; 2652 *(unsigned short *)(mtag + 1) = nd_rd->nd_rd_type; 2653 m_tag_prepend(m, mtag); 2654 } 2655 2656 /* send the packet to outside... */ 2657 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2658 if (outif) { 2659 icmp6_ifstat_inc(outif, ifs6_out_msg); 2660 icmp6_ifstat_inc(outif, ifs6_out_redirect); 2661 } 2662 ICMP6STAT_INC(icp6s_outhist[ND_REDIRECT]); 2663 2664 return; 2665 2666 fail: 2667 if (m) 2668 m_freem(m); 2669 if (m0) 2670 m_freem(m0); 2671 } 2672 2673 /* 2674 * ICMPv6 socket option processing. 2675 */ 2676 int 2677 icmp6_ctloutput(struct socket *so, struct sockopt *sopt) 2678 { 2679 int error = 0; 2680 int optlen; 2681 struct inpcb *inp = sotoinpcb(so); 2682 int level, op, optname; 2683 2684 if (sopt) { 2685 level = sopt->sopt_level; 2686 op = sopt->sopt_dir; 2687 optname = sopt->sopt_name; 2688 optlen = sopt->sopt_valsize; 2689 } else 2690 level = op = optname = optlen = 0; 2691 2692 if (level != IPPROTO_ICMPV6) { 2693 return EINVAL; 2694 } 2695 2696 switch (op) { 2697 case PRCO_SETOPT: 2698 switch (optname) { 2699 case ICMP6_FILTER: 2700 { 2701 struct icmp6_filter ic6f; 2702 2703 if (optlen != sizeof(ic6f)) { 2704 error = EMSGSIZE; 2705 break; 2706 } 2707 error = sooptcopyin(sopt, &ic6f, optlen, optlen); 2708 if (error == 0) { 2709 INP_WLOCK(inp); 2710 *inp->in6p_icmp6filt = ic6f; 2711 INP_WUNLOCK(inp); 2712 } 2713 break; 2714 } 2715 2716 default: 2717 error = ENOPROTOOPT; 2718 break; 2719 } 2720 break; 2721 2722 case PRCO_GETOPT: 2723 switch (optname) { 2724 case ICMP6_FILTER: 2725 { 2726 struct icmp6_filter ic6f; 2727 2728 INP_RLOCK(inp); 2729 ic6f = *inp->in6p_icmp6filt; 2730 INP_RUNLOCK(inp); 2731 error = sooptcopyout(sopt, &ic6f, sizeof(ic6f)); 2732 break; 2733 } 2734 2735 default: 2736 error = ENOPROTOOPT; 2737 break; 2738 } 2739 break; 2740 } 2741 2742 return (error); 2743 } 2744 2745 /* 2746 * Perform rate limit check. 2747 * Returns 0 if it is okay to send the icmp6 packet. 2748 * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate 2749 * limitation. 2750 * 2751 * XXX per-destination/type check necessary? 2752 * 2753 * dst - not used at this moment 2754 * type - not used at this moment 2755 * code - not used at this moment 2756 */ 2757 static int 2758 icmp6_ratelimit(const struct in6_addr *dst, const int type, 2759 const int code) 2760 { 2761 int ret; 2762 2763 ret = 0; /* okay to send */ 2764 2765 /* PPS limit */ 2766 if (!ppsratecheck(&V_icmp6errppslim_last, &V_icmp6errpps_count, 2767 V_icmp6errppslim)) { 2768 /* The packet is subject to rate limit */ 2769 ret++; 2770 } 2771 2772 return ret; 2773 } 2774