Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/netinet6/icmp6.c
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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 if (m->m_len < off + sizeof(struct icmp6_hdr)) { 321 m = m_pullup(m, off + sizeof(struct icmp6_hdr)); 322 if (m == NULL) { 323 IP6STAT_INC(ip6s_exthdrtoolong); 324 return; 325 } 326 } 327 oip6 = mtod(m, struct ip6_hdr *); 328 icp = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 329 330 if (icp->icmp6_type < ICMP6_ECHO_REQUEST || 331 icp->icmp6_type == ND_REDIRECT) { 332 /* 333 * ICMPv6 error 334 * Special case: for redirect (which is 335 * informational) we must not send icmp6 error. 336 */ 337 ICMP6STAT_INC(icp6s_canterror); 338 goto freeit; 339 } else { 340 /* ICMPv6 informational - send the error */ 341 } 342 } else { 343 /* non-ICMPv6 - send the error */ 344 } 345 346 /* Finally, do rate limitation check. */ 347 if (icmp6_ratelimit(&oip6->ip6_src, type, code)) { 348 ICMP6STAT_INC(icp6s_toofreq); 349 goto freeit; 350 } 351 352 /* 353 * OK, ICMP6 can be generated. 354 */ 355 356 if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN) 357 m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len); 358 359 preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 360 M_PREPEND(m, preplen, M_NOWAIT); /* FIB is also copied over. */ 361 if (m == NULL) { 362 nd6log((LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__)); 363 return; 364 } 365 366 nip6 = mtod(m, struct ip6_hdr *); 367 nip6->ip6_src = oip6->ip6_src; 368 nip6->ip6_dst = oip6->ip6_dst; 369 370 in6_clearscope(&oip6->ip6_src); 371 in6_clearscope(&oip6->ip6_dst); 372 373 icmp6 = (struct icmp6_hdr *)(nip6 + 1); 374 icmp6->icmp6_type = type; 375 icmp6->icmp6_code = code; 376 icmp6->icmp6_pptr = htonl((u_int32_t)param); 377 378 ICMP6STAT_INC(icp6s_outhist[type]); 379 icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */ 380 381 return; 382 383 freeit: 384 /* 385 * If we can't tell whether or not we can generate ICMP6, free it. 386 */ 387 m_freem(m); 388 } 389 390 /* 391 * Process a received ICMP6 message. 392 */ 393 int 394 icmp6_input(struct mbuf **mp, int *offp, int proto) 395 { 396 struct mbuf *m, *n; 397 struct ifnet *ifp; 398 struct ip6_hdr *ip6, *nip6; 399 struct icmp6_hdr *icmp6, *nicmp6; 400 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 401 int code, error, icmp6len, ip6len, noff, off, sum; 402 403 m = *mp; 404 off = *offp; 405 406 if (m->m_len < off + sizeof(struct icmp6_hdr)) { 407 m = m_pullup(m, off + sizeof(struct icmp6_hdr)); 408 if (m == NULL) { 409 IP6STAT_INC(ip6s_exthdrtoolong); 410 *mp = m; 411 return (IPPROTO_DONE); 412 } 413 } 414 415 /* 416 * Locate icmp6 structure in mbuf, and check 417 * that not corrupted and of at least minimum length 418 */ 419 420 icmp6len = m->m_pkthdr.len - off; 421 if (icmp6len < sizeof(struct icmp6_hdr)) { 422 ICMP6STAT_INC(icp6s_tooshort); 423 goto freeit; 424 } 425 426 ip6 = mtod(m, struct ip6_hdr *); 427 ifp = m->m_pkthdr.rcvif; 428 /* 429 * Check multicast group membership. 430 * Note: SSM filters are not applied for ICMPv6 traffic. 431 */ 432 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 433 struct in6_multi *inm; 434 435 inm = in6m_lookup(ifp, &ip6->ip6_dst); 436 if (inm == NULL) { 437 IP6STAT_INC(ip6s_notmember); 438 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 439 goto freeit; 440 } 441 } 442 443 /* Calculate the checksum. */ 444 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off); 445 code = icmp6->icmp6_code; 446 if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) { 447 nd6log((LOG_ERR, 448 "ICMP6 checksum error(%d|%x) %s\n", 449 icmp6->icmp6_type, sum, 450 ip6_sprintf(ip6bufs, &ip6->ip6_src))); 451 ICMP6STAT_INC(icp6s_checksum); 452 goto freeit; 453 } 454 455 ICMP6STAT_INC(icp6s_inhist[icmp6->icmp6_type]); 456 icmp6_ifstat_inc(ifp, ifs6_in_msg); 457 if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK) 458 icmp6_ifstat_inc(ifp, ifs6_in_error); 459 460 ip6len = sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen); 461 switch (icmp6->icmp6_type) { 462 case ICMP6_DST_UNREACH: 463 icmp6_ifstat_inc(ifp, ifs6_in_dstunreach); 464 switch (code) { 465 case ICMP6_DST_UNREACH_NOROUTE: 466 case ICMP6_DST_UNREACH_ADDR: /* PRC_HOSTDEAD is a DOS */ 467 code = PRC_UNREACH_NET; 468 break; 469 case ICMP6_DST_UNREACH_ADMIN: 470 icmp6_ifstat_inc(ifp, ifs6_in_adminprohib); 471 code = PRC_UNREACH_ADMIN_PROHIB; 472 break; 473 case ICMP6_DST_UNREACH_BEYONDSCOPE: 474 /* I mean "source address was incorrect." */ 475 code = PRC_PARAMPROB; 476 break; 477 case ICMP6_DST_UNREACH_NOPORT: 478 code = PRC_UNREACH_PORT; 479 break; 480 default: 481 goto badcode; 482 } 483 goto deliver; 484 break; 485 486 case ICMP6_PACKET_TOO_BIG: 487 icmp6_ifstat_inc(ifp, ifs6_in_pkttoobig); 488 489 /* validation is made in icmp6_mtudisc_update */ 490 491 code = PRC_MSGSIZE; 492 493 /* 494 * Updating the path MTU will be done after examining 495 * intermediate extension headers. 496 */ 497 goto deliver; 498 break; 499 500 case ICMP6_TIME_EXCEEDED: 501 icmp6_ifstat_inc(ifp, ifs6_in_timeexceed); 502 switch (code) { 503 case ICMP6_TIME_EXCEED_TRANSIT: 504 code = PRC_TIMXCEED_INTRANS; 505 break; 506 case ICMP6_TIME_EXCEED_REASSEMBLY: 507 code = PRC_TIMXCEED_REASS; 508 break; 509 default: 510 goto badcode; 511 } 512 goto deliver; 513 break; 514 515 case ICMP6_PARAM_PROB: 516 icmp6_ifstat_inc(ifp, ifs6_in_paramprob); 517 switch (code) { 518 case ICMP6_PARAMPROB_NEXTHEADER: 519 code = PRC_UNREACH_PROTOCOL; 520 break; 521 case ICMP6_PARAMPROB_HEADER: 522 case ICMP6_PARAMPROB_OPTION: 523 code = PRC_PARAMPROB; 524 break; 525 default: 526 goto badcode; 527 } 528 goto deliver; 529 break; 530 531 case ICMP6_ECHO_REQUEST: 532 icmp6_ifstat_inc(ifp, ifs6_in_echo); 533 if (code != 0) 534 goto badcode; 535 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) { 536 /* Give up remote */ 537 break; 538 } 539 if (!M_WRITABLE(n) 540 || n->m_len < off + sizeof(struct icmp6_hdr)) { 541 struct mbuf *n0 = n; 542 int n0len; 543 544 CTASSERT(sizeof(*nip6) + sizeof(*nicmp6) <= MHLEN); 545 n = m_gethdr(M_NOWAIT, n0->m_type); 546 if (n == NULL) { 547 /* Give up remote */ 548 m_freem(n0); 549 break; 550 } 551 552 m_move_pkthdr(n, n0); /* FIB copied. */ 553 n0len = n0->m_pkthdr.len; /* save for use below */ 554 /* 555 * Copy IPv6 and ICMPv6 only. 556 */ 557 nip6 = mtod(n, struct ip6_hdr *); 558 bcopy(ip6, nip6, sizeof(struct ip6_hdr)); 559 nicmp6 = (struct icmp6_hdr *)(nip6 + 1); 560 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr)); 561 noff = sizeof(struct ip6_hdr); 562 /* new mbuf contains only ipv6+icmpv6 headers */ 563 n->m_len = noff + sizeof(struct icmp6_hdr); 564 /* 565 * Adjust mbuf. ip6_plen will be adjusted in 566 * ip6_output(). 567 */ 568 m_adj(n0, off + sizeof(struct icmp6_hdr)); 569 /* recalculate complete packet size */ 570 n->m_pkthdr.len = n0len + (noff - off); 571 n->m_next = n0; 572 } else { 573 if (n->m_len < off + sizeof(*nicmp6)) { 574 n = m_pullup(n, off + sizeof(*nicmp6)); 575 if (n == NULL) { 576 IP6STAT_INC(ip6s_exthdrtoolong); 577 break; 578 } 579 } 580 nicmp6 = (struct icmp6_hdr *)(mtod(n, caddr_t) + off); 581 noff = off; 582 } 583 if (n) { 584 nicmp6->icmp6_type = ICMP6_ECHO_REPLY; 585 nicmp6->icmp6_code = 0; 586 ICMP6STAT_INC(icp6s_reflect); 587 ICMP6STAT_INC(icp6s_outhist[ICMP6_ECHO_REPLY]); 588 icmp6_reflect(n, noff); 589 } 590 break; 591 592 case ICMP6_ECHO_REPLY: 593 icmp6_ifstat_inc(ifp, ifs6_in_echoreply); 594 if (code != 0) 595 goto badcode; 596 break; 597 598 case MLD_LISTENER_QUERY: 599 case MLD_LISTENER_REPORT: 600 case MLD_LISTENER_DONE: 601 case MLDV2_LISTENER_REPORT: 602 /* 603 * Drop MLD traffic which is not link-local, has a hop limit 604 * of greater than 1 hop, or which does not have the 605 * IPv6 HBH Router Alert option. 606 * As IPv6 HBH options are stripped in ip6_input() we must 607 * check an mbuf header flag. 608 * XXX Should we also sanity check that these messages 609 * were directed to a link-local multicast prefix? 610 */ 611 if ((ip6->ip6_hlim != 1) || (m->m_flags & M_RTALERT_MLD) == 0) 612 goto freeit; 613 if (mld_input(&m, off, icmp6len) != 0) { 614 *mp = NULL; 615 return (IPPROTO_DONE); 616 } 617 /* m stays. */ 618 break; 619 620 case ICMP6_WRUREQUEST: /* ICMP6_FQDN_QUERY */ 621 { 622 enum { WRU, FQDN } mode; 623 struct prison *pr; 624 625 if (!V_icmp6_nodeinfo) 626 break; 627 628 if (icmp6len == sizeof(struct icmp6_hdr) + 4) 629 mode = WRU; 630 else if (icmp6len >= sizeof(struct icmp6_nodeinfo)) 631 mode = FQDN; 632 else 633 goto badlen; 634 635 pr = NULL; 636 sx_slock(&allprison_lock); 637 TAILQ_FOREACH(pr, &allprison, pr_list) 638 if (pr->pr_vnet == ifp->if_vnet) 639 break; 640 sx_sunlock(&allprison_lock); 641 if (pr == NULL) 642 pr = curthread->td_ucred->cr_prison; 643 if (mode == FQDN) { 644 if (m->m_len < off + sizeof(struct icmp6_nodeinfo)) { 645 m = m_pullup(m, off + 646 sizeof(struct icmp6_nodeinfo)); 647 if (m == NULL) { 648 IP6STAT_INC(ip6s_exthdrtoolong); 649 *mp = m; 650 return (IPPROTO_DONE); 651 } 652 } 653 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 654 if (n) 655 n = ni6_input(n, off, pr); 656 /* XXX meaningless if n == NULL */ 657 noff = sizeof(struct ip6_hdr); 658 } else { 659 u_char *p; 660 int maxhlen, hlen; 661 662 /* 663 * XXX: this combination of flags is pointless, 664 * but should we keep this for compatibility? 665 */ 666 if ((V_icmp6_nodeinfo & (ICMP6_NODEINFO_FQDNOK | 667 ICMP6_NODEINFO_TMPADDROK)) != 668 (ICMP6_NODEINFO_FQDNOK | ICMP6_NODEINFO_TMPADDROK)) 669 break; 670 671 if (code != 0) 672 goto badcode; 673 674 CTASSERT(sizeof(*nip6) + sizeof(*nicmp6) + 4 <= MHLEN); 675 n = m_gethdr(M_NOWAIT, m->m_type); 676 if (n == NULL) { 677 /* Give up remote */ 678 break; 679 } 680 if (!m_dup_pkthdr(n, m, M_NOWAIT)) { 681 /* 682 * Previous code did a blind M_COPY_PKTHDR 683 * and said "just for rcvif". If true, then 684 * we could tolerate the dup failing (due to 685 * the deep copy of the tag chain). For now 686 * be conservative and just fail. 687 */ 688 m_free(n); 689 n = NULL; 690 break; 691 } 692 /* 693 * Copy IPv6 and ICMPv6 only. 694 */ 695 nip6 = mtod(n, struct ip6_hdr *); 696 bcopy(ip6, nip6, sizeof(struct ip6_hdr)); 697 nicmp6 = (struct icmp6_hdr *)(nip6 + 1); 698 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr)); 699 p = (u_char *)(nicmp6 + 1); 700 bzero(p, 4); 701 702 maxhlen = M_TRAILINGSPACE(n) - 703 (sizeof(*nip6) + sizeof(*nicmp6) + 4); 704 mtx_lock(&pr->pr_mtx); 705 hlen = strlen(pr->pr_hostname); 706 if (maxhlen > hlen) 707 maxhlen = hlen; 708 /* meaningless TTL */ 709 bcopy(pr->pr_hostname, p + 4, maxhlen); 710 mtx_unlock(&pr->pr_mtx); 711 noff = sizeof(struct ip6_hdr); 712 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + 713 sizeof(struct icmp6_hdr) + 4 + maxhlen; 714 nicmp6->icmp6_type = ICMP6_WRUREPLY; 715 nicmp6->icmp6_code = 0; 716 } 717 if (n) { 718 ICMP6STAT_INC(icp6s_reflect); 719 ICMP6STAT_INC(icp6s_outhist[ICMP6_WRUREPLY]); 720 icmp6_reflect(n, noff); 721 } 722 break; 723 } 724 725 case ICMP6_WRUREPLY: 726 if (code != 0) 727 goto badcode; 728 break; 729 730 case ND_ROUTER_SOLICIT: 731 icmp6_ifstat_inc(ifp, ifs6_in_routersolicit); 732 if (code != 0) 733 goto badcode; 734 if (icmp6len < sizeof(struct nd_router_solicit)) 735 goto badlen; 736 if (send_sendso_input_hook != NULL) { 737 if (m->m_len < off + icmp6len) { 738 m = m_pullup(m, off + icmp6len); 739 if (m == NULL) { 740 IP6STAT_INC(ip6s_exthdrtoolong); 741 *mp = NULL; 742 return (IPPROTO_DONE); 743 } 744 } 745 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 746 if (error == 0) { 747 m = NULL; 748 goto freeit; 749 } 750 } 751 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 752 nd6_rs_input(m, off, icmp6len); 753 m = n; 754 if (m == NULL) 755 goto freeit; 756 break; 757 758 case ND_ROUTER_ADVERT: 759 icmp6_ifstat_inc(ifp, ifs6_in_routeradvert); 760 if (code != 0) 761 goto badcode; 762 if (icmp6len < sizeof(struct nd_router_advert)) 763 goto badlen; 764 if (send_sendso_input_hook != NULL) { 765 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 766 if (error == 0) { 767 m = NULL; 768 goto freeit; 769 } 770 } 771 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 772 nd6_ra_input(m, off, icmp6len); 773 m = n; 774 if (m == NULL) 775 goto freeit; 776 break; 777 778 case ND_NEIGHBOR_SOLICIT: 779 icmp6_ifstat_inc(ifp, ifs6_in_neighborsolicit); 780 if (code != 0) 781 goto badcode; 782 if (icmp6len < sizeof(struct nd_neighbor_solicit)) 783 goto badlen; 784 if (send_sendso_input_hook != NULL) { 785 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 786 if (error == 0) { 787 m = NULL; 788 goto freeit; 789 } 790 } 791 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 792 nd6_ns_input(m, off, icmp6len); 793 m = n; 794 if (m == NULL) 795 goto freeit; 796 break; 797 798 case ND_NEIGHBOR_ADVERT: 799 icmp6_ifstat_inc(ifp, ifs6_in_neighboradvert); 800 if (code != 0) 801 goto badcode; 802 if (icmp6len < sizeof(struct nd_neighbor_advert)) 803 goto badlen; 804 if (send_sendso_input_hook != NULL) { 805 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 806 if (error == 0) { 807 m = NULL; 808 goto freeit; 809 } 810 } 811 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 812 nd6_na_input(m, off, icmp6len); 813 m = n; 814 if (m == NULL) 815 goto freeit; 816 break; 817 818 case ND_REDIRECT: 819 icmp6_ifstat_inc(ifp, ifs6_in_redirect); 820 if (code != 0) 821 goto badcode; 822 if (icmp6len < sizeof(struct nd_redirect)) 823 goto badlen; 824 if (send_sendso_input_hook != NULL) { 825 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 826 if (error == 0) { 827 m = NULL; 828 goto freeit; 829 } 830 } 831 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 832 icmp6_redirect_input(m, off); 833 m = n; 834 if (m == NULL) 835 goto freeit; 836 break; 837 838 case ICMP6_ROUTER_RENUMBERING: 839 if (code != ICMP6_ROUTER_RENUMBERING_COMMAND && 840 code != ICMP6_ROUTER_RENUMBERING_RESULT) 841 goto badcode; 842 if (icmp6len < sizeof(struct icmp6_router_renum)) 843 goto badlen; 844 break; 845 846 default: 847 nd6log((LOG_DEBUG, 848 "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n", 849 icmp6->icmp6_type, ip6_sprintf(ip6bufs, &ip6->ip6_src), 850 ip6_sprintf(ip6bufd, &ip6->ip6_dst), 851 ifp ? ifp->if_index : 0)); 852 if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) { 853 /* ICMPv6 error: MUST deliver it by spec... */ 854 code = PRC_NCMDS; 855 /* deliver */ 856 } else { 857 /* ICMPv6 informational: MUST not deliver */ 858 break; 859 } 860 deliver: 861 if (icmp6_notify_error(&m, off, icmp6len, code) != 0) { 862 /* In this case, m should've been freed. */ 863 *mp = NULL; 864 return (IPPROTO_DONE); 865 } 866 break; 867 868 badcode: 869 ICMP6STAT_INC(icp6s_badcode); 870 break; 871 872 badlen: 873 ICMP6STAT_INC(icp6s_badlen); 874 break; 875 } 876 877 /* deliver the packet to appropriate sockets */ 878 icmp6_rip6_input(&m, *offp); 879 880 *mp = m; 881 return (IPPROTO_DONE); 882 883 freeit: 884 m_freem(m); 885 *mp = NULL; 886 return (IPPROTO_DONE); 887 } 888 889 static int 890 icmp6_notify_error(struct mbuf **mp, int off, int icmp6len, int code) 891 { 892 struct mbuf *m; 893 struct icmp6_hdr *icmp6; 894 struct ip6_hdr *eip6; 895 u_int32_t notifymtu; 896 struct sockaddr_in6 icmp6src, icmp6dst; 897 898 m = *mp; 899 900 if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) { 901 ICMP6STAT_INC(icp6s_tooshort); 902 goto freeit; 903 } 904 905 if (m->m_len < off + sizeof(*icmp6) + sizeof(struct ip6_hdr)) { 906 m = m_pullup(m, off + sizeof(*icmp6) + sizeof(struct ip6_hdr)); 907 if (m == NULL) { 908 IP6STAT_INC(ip6s_exthdrtoolong); 909 *mp = m; 910 return (-1); 911 } 912 } 913 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 914 eip6 = (struct ip6_hdr *)(icmp6 + 1); 915 bzero(&icmp6dst, sizeof(icmp6dst)); 916 917 /* Detect the upper level protocol */ 918 { 919 void (*ctlfunc)(int, struct sockaddr *, void *); 920 u_int8_t nxt = eip6->ip6_nxt; 921 int eoff = off + sizeof(struct icmp6_hdr) + 922 sizeof(struct ip6_hdr); 923 struct ip6ctlparam ip6cp; 924 int icmp6type = icmp6->icmp6_type; 925 struct ip6_frag *fh; 926 struct ip6_rthdr *rth; 927 struct ip6_rthdr0 *rth0; 928 int rthlen; 929 930 while (1) { /* XXX: should avoid infinite loop explicitly? */ 931 struct ip6_ext *eh; 932 933 switch (nxt) { 934 case IPPROTO_HOPOPTS: 935 case IPPROTO_DSTOPTS: 936 case IPPROTO_AH: 937 if (m->m_len < eoff + sizeof(struct ip6_ext)) { 938 m = m_pullup(m, eoff + 939 sizeof(struct ip6_ext)); 940 if (m == NULL) { 941 IP6STAT_INC(ip6s_exthdrtoolong); 942 *mp = m; 943 return (-1); 944 } 945 } 946 eh = (struct ip6_ext *) 947 (mtod(m, caddr_t) + eoff); 948 if (nxt == IPPROTO_AH) 949 eoff += (eh->ip6e_len + 2) << 2; 950 else 951 eoff += (eh->ip6e_len + 1) << 3; 952 nxt = eh->ip6e_nxt; 953 break; 954 case IPPROTO_ROUTING: 955 /* 956 * When the erroneous packet contains a 957 * routing header, we should examine the 958 * header to determine the final destination. 959 * Otherwise, we can't properly update 960 * information that depends on the final 961 * destination (e.g. path MTU). 962 */ 963 if (m->m_len < eoff + sizeof(*rth)) { 964 m = m_pullup(m, eoff + sizeof(*rth)); 965 if (m == NULL) { 966 IP6STAT_INC(ip6s_exthdrtoolong); 967 *mp = m; 968 return (-1); 969 } 970 } 971 rth = (struct ip6_rthdr *) 972 (mtod(m, caddr_t) + eoff); 973 rthlen = (rth->ip6r_len + 1) << 3; 974 /* 975 * XXX: currently there is no 976 * officially defined type other 977 * than type-0. 978 * Note that if the segment left field 979 * is 0, all intermediate hops must 980 * have been passed. 981 */ 982 if (rth->ip6r_segleft && 983 rth->ip6r_type == IPV6_RTHDR_TYPE_0) { 984 int hops; 985 986 if (m->m_len < eoff + rthlen) { 987 m = m_pullup(m, eoff + rthlen); 988 if (m == NULL) { 989 IP6STAT_INC( 990 ip6s_exthdrtoolong); 991 *mp = m; 992 return (-1); 993 } 994 } 995 rth0 = (struct ip6_rthdr0 *) 996 (mtod(m, caddr_t) + eoff); 997 998 /* just ignore a bogus header */ 999 if ((rth0->ip6r0_len % 2) == 0 && 1000 (hops = rth0->ip6r0_len/2)) 1001 icmp6dst.sin6_addr = *((struct in6_addr *)(rth0 + 1) + (hops - 1)); 1002 } 1003 eoff += rthlen; 1004 nxt = rth->ip6r_nxt; 1005 break; 1006 case IPPROTO_FRAGMENT: 1007 if (m->m_len < eoff + sizeof(struct ip6_frag)) { 1008 m = m_pullup(m, eoff + 1009 sizeof(struct ip6_frag)); 1010 if (m == NULL) { 1011 IP6STAT_INC(ip6s_exthdrtoolong); 1012 *mp = m; 1013 return (-1); 1014 } 1015 } 1016 fh = (struct ip6_frag *)(mtod(m, caddr_t) + 1017 eoff); 1018 /* 1019 * Data after a fragment header is meaningless 1020 * unless it is the first fragment, but 1021 * we'll go to the notify label for path MTU 1022 * discovery. 1023 */ 1024 if (fh->ip6f_offlg & IP6F_OFF_MASK) 1025 goto notify; 1026 1027 eoff += sizeof(struct ip6_frag); 1028 nxt = fh->ip6f_nxt; 1029 break; 1030 default: 1031 /* 1032 * This case includes ESP and the No Next 1033 * Header. In such cases going to the notify 1034 * label does not have any meaning 1035 * (i.e. ctlfunc will be NULL), but we go 1036 * anyway since we might have to update 1037 * path MTU information. 1038 */ 1039 goto notify; 1040 } 1041 } 1042 notify: 1043 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 1044 1045 /* 1046 * retrieve parameters from the inner IPv6 header, and convert 1047 * them into sockaddr structures. 1048 * XXX: there is no guarantee that the source or destination 1049 * addresses of the inner packet are in the same scope as 1050 * the addresses of the icmp packet. But there is no other 1051 * way to determine the zone. 1052 */ 1053 eip6 = (struct ip6_hdr *)(icmp6 + 1); 1054 1055 icmp6dst.sin6_len = sizeof(struct sockaddr_in6); 1056 icmp6dst.sin6_family = AF_INET6; 1057 if (IN6_IS_ADDR_UNSPECIFIED(&icmp6dst.sin6_addr)) 1058 icmp6dst.sin6_addr = eip6->ip6_dst; 1059 if (in6_setscope(&icmp6dst.sin6_addr, m->m_pkthdr.rcvif, NULL)) 1060 goto freeit; 1061 bzero(&icmp6src, sizeof(icmp6src)); 1062 icmp6src.sin6_len = sizeof(struct sockaddr_in6); 1063 icmp6src.sin6_family = AF_INET6; 1064 icmp6src.sin6_addr = eip6->ip6_src; 1065 if (in6_setscope(&icmp6src.sin6_addr, m->m_pkthdr.rcvif, NULL)) 1066 goto freeit; 1067 icmp6src.sin6_flowinfo = 1068 (eip6->ip6_flow & IPV6_FLOWLABEL_MASK); 1069 1070 ip6cp.ip6c_m = m; 1071 ip6cp.ip6c_icmp6 = icmp6; 1072 ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1); 1073 ip6cp.ip6c_off = eoff; 1074 ip6cp.ip6c_finaldst = &icmp6dst.sin6_addr; 1075 ip6cp.ip6c_src = &icmp6src; 1076 ip6cp.ip6c_nxt = nxt; 1077 1078 if (icmp6type == ICMP6_PACKET_TOO_BIG) { 1079 notifymtu = ntohl(icmp6->icmp6_mtu); 1080 ip6cp.ip6c_cmdarg = (void *)¬ifymtu; 1081 icmp6_mtudisc_update(&ip6cp, 1); /*XXX*/ 1082 } 1083 1084 ctlfunc = (void (*)(int, struct sockaddr *, void *)) 1085 (inet6sw[ip6_protox[nxt]].pr_ctlinput); 1086 if (ctlfunc) { 1087 (void) (*ctlfunc)(code, (struct sockaddr *)&icmp6dst, 1088 &ip6cp); 1089 } 1090 } 1091 *mp = m; 1092 return (0); 1093 1094 freeit: 1095 m_freem(m); 1096 *mp = NULL; 1097 return (-1); 1098 } 1099 1100 void 1101 icmp6_mtudisc_update(struct ip6ctlparam *ip6cp, int validated) 1102 { 1103 struct in6_addr *dst = ip6cp->ip6c_finaldst; 1104 struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6; 1105 struct mbuf *m = ip6cp->ip6c_m; /* will be necessary for scope issue */ 1106 u_int mtu = ntohl(icmp6->icmp6_mtu); 1107 struct in_conninfo inc; 1108 1109 #if 0 1110 /* 1111 * RFC2460 section 5, last paragraph. 1112 * even though minimum link MTU for IPv6 is IPV6_MMTU, 1113 * we may see ICMPv6 too big with mtu < IPV6_MMTU 1114 * due to packet translator in the middle. 1115 * see ip6_output() and ip6_getpmtu() "alwaysfrag" case for 1116 * special handling. 1117 */ 1118 if (mtu < IPV6_MMTU) 1119 return; 1120 #endif 1121 1122 /* 1123 * we reject ICMPv6 too big with abnormally small value. 1124 * XXX what is the good definition of "abnormally small"? 1125 */ 1126 if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8) 1127 return; 1128 1129 if (!validated) 1130 return; 1131 1132 /* 1133 * In case the suggested mtu is less than IPV6_MMTU, we 1134 * only need to remember that it was for above mentioned 1135 * "alwaysfrag" case. 1136 * Try to be as close to the spec as possible. 1137 */ 1138 if (mtu < IPV6_MMTU) 1139 mtu = IPV6_MMTU - 8; 1140 1141 bzero(&inc, sizeof(inc)); 1142 inc.inc_fibnum = M_GETFIB(m); 1143 inc.inc_flags |= INC_ISIPV6; 1144 inc.inc6_faddr = *dst; 1145 if (in6_setscope(&inc.inc6_faddr, m->m_pkthdr.rcvif, NULL)) 1146 return; 1147 1148 if (mtu < tcp_maxmtu6(&inc, NULL)) { 1149 tcp_hc_updatemtu(&inc, mtu); 1150 ICMP6STAT_INC(icp6s_pmtuchg); 1151 } 1152 } 1153 1154 /* 1155 * Process a Node Information Query packet, based on 1156 * draft-ietf-ipngwg-icmp-name-lookups-07. 1157 * 1158 * Spec incompatibilities: 1159 * - IPv6 Subject address handling 1160 * - IPv4 Subject address handling support missing 1161 * - Proxy reply (answer even if it's not for me) 1162 * - joins NI group address at in6_ifattach() time only, does not cope 1163 * with hostname changes by sethostname(3) 1164 */ 1165 static struct mbuf * 1166 ni6_input(struct mbuf *m, int off, struct prison *pr) 1167 { 1168 struct icmp6_nodeinfo *ni6, *nni6; 1169 struct mbuf *n = NULL; 1170 u_int16_t qtype; 1171 int subjlen; 1172 int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); 1173 struct ni_reply_fqdn *fqdn; 1174 int addrs; /* for NI_QTYPE_NODEADDR */ 1175 struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */ 1176 struct in6_addr in6_subj; /* subject address */ 1177 struct ip6_hdr *ip6; 1178 int oldfqdn = 0; /* if 1, return pascal string (03 draft) */ 1179 char *subj = NULL; 1180 struct in6_ifaddr *ia6 = NULL; 1181 1182 ip6 = mtod(m, struct ip6_hdr *); 1183 ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off); 1184 1185 /* 1186 * Validate IPv6 source address. 1187 * The default configuration MUST be to refuse answering queries from 1188 * global-scope addresses according to RFC4602. 1189 * Notes: 1190 * - it's not very clear what "refuse" means; this implementation 1191 * simply drops it. 1192 * - it's not very easy to identify global-scope (unicast) addresses 1193 * since there are many prefixes for them. It should be safer 1194 * and in practice sufficient to check "all" but loopback and 1195 * link-local (note that site-local unicast was deprecated and 1196 * ULA is defined as global scope-wise) 1197 */ 1198 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_GLOBALOK) == 0 && 1199 !IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) && 1200 !IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) 1201 goto bad; 1202 1203 /* 1204 * Validate IPv6 destination address. 1205 * 1206 * The Responder must discard the Query without further processing 1207 * unless it is one of the Responder's unicast or anycast addresses, or 1208 * a link-local scope multicast address which the Responder has joined. 1209 * [RFC4602, Section 5.] 1210 */ 1211 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 1212 if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst)) 1213 goto bad; 1214 /* else it's a link-local multicast, fine */ 1215 } else { /* unicast or anycast */ 1216 ia6 = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */); 1217 if (ia6 == NULL) 1218 goto bad; /* XXX impossible */ 1219 1220 if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) && 1221 !(V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK)) { 1222 ifa_free(&ia6->ia_ifa); 1223 nd6log((LOG_DEBUG, "ni6_input: ignore node info to " 1224 "a temporary address in %s:%d", 1225 __FILE__, __LINE__)); 1226 goto bad; 1227 } 1228 ifa_free(&ia6->ia_ifa); 1229 } 1230 1231 /* validate query Subject field. */ 1232 qtype = ntohs(ni6->ni_qtype); 1233 subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo); 1234 switch (qtype) { 1235 case NI_QTYPE_NOOP: 1236 case NI_QTYPE_SUPTYPES: 1237 /* 07 draft */ 1238 if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0) 1239 break; 1240 /* FALLTHROUGH */ 1241 case NI_QTYPE_FQDN: 1242 case NI_QTYPE_NODEADDR: 1243 case NI_QTYPE_IPV4ADDR: 1244 switch (ni6->ni_code) { 1245 case ICMP6_NI_SUBJ_IPV6: 1246 #if ICMP6_NI_SUBJ_IPV6 != 0 1247 case 0: 1248 #endif 1249 /* 1250 * backward compatibility - try to accept 03 draft 1251 * format, where no Subject is present. 1252 */ 1253 if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 && 1254 subjlen == 0) { 1255 oldfqdn++; 1256 break; 1257 } 1258 #if ICMP6_NI_SUBJ_IPV6 != 0 1259 if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6) 1260 goto bad; 1261 #endif 1262 1263 if (subjlen != sizeof(struct in6_addr)) 1264 goto bad; 1265 1266 /* 1267 * Validate Subject address. 1268 * 1269 * Not sure what exactly "address belongs to the node" 1270 * means in the spec, is it just unicast, or what? 1271 * 1272 * At this moment we consider Subject address as 1273 * "belong to the node" if the Subject address equals 1274 * to the IPv6 destination address; validation for 1275 * IPv6 destination address should have done enough 1276 * check for us. 1277 * 1278 * We do not do proxy at this moment. 1279 */ 1280 m_copydata(m, off + sizeof(struct icmp6_nodeinfo), 1281 subjlen, (caddr_t)&in6_subj); 1282 if (in6_setscope(&in6_subj, m->m_pkthdr.rcvif, NULL)) 1283 goto bad; 1284 1285 subj = (char *)&in6_subj; 1286 if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &in6_subj)) 1287 break; 1288 1289 /* 1290 * XXX if we are to allow other cases, we should really 1291 * be careful about scope here. 1292 * basically, we should disallow queries toward IPv6 1293 * destination X with subject Y, 1294 * if scope(X) > scope(Y). 1295 * if we allow scope(X) > scope(Y), it will result in 1296 * information leakage across scope boundary. 1297 */ 1298 goto bad; 1299 1300 case ICMP6_NI_SUBJ_FQDN: 1301 /* 1302 * Validate Subject name with gethostname(3). 1303 * 1304 * The behavior may need some debate, since: 1305 * - we are not sure if the node has FQDN as 1306 * hostname (returned by gethostname(3)). 1307 * - the code does wildcard match for truncated names. 1308 * however, we are not sure if we want to perform 1309 * wildcard match, if gethostname(3) side has 1310 * truncated hostname. 1311 */ 1312 mtx_lock(&pr->pr_mtx); 1313 n = ni6_nametodns(pr->pr_hostname, 1314 strlen(pr->pr_hostname), 0); 1315 mtx_unlock(&pr->pr_mtx); 1316 if (!n || n->m_next || n->m_len == 0) 1317 goto bad; 1318 if (m->m_len < off + sizeof(struct icmp6_nodeinfo) + 1319 subjlen) { 1320 m = m_pullup(m, off + 1321 sizeof(struct icmp6_nodeinfo) + subjlen); 1322 if (m == NULL) { 1323 IP6STAT_INC(ip6s_exthdrtoolong); 1324 goto bad; 1325 } 1326 } 1327 /* ip6 possibly invalid but not used after. */ 1328 ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off); 1329 subj = (char *)(mtod(m, caddr_t) + off + 1330 sizeof(struct icmp6_nodeinfo)); 1331 if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *), 1332 n->m_len)) { 1333 goto bad; 1334 } 1335 m_freem(n); 1336 n = NULL; 1337 break; 1338 1339 case ICMP6_NI_SUBJ_IPV4: /* XXX: to be implemented? */ 1340 default: 1341 goto bad; 1342 } 1343 break; 1344 } 1345 1346 /* refuse based on configuration. XXX ICMP6_NI_REFUSED? */ 1347 switch (qtype) { 1348 case NI_QTYPE_FQDN: 1349 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_FQDNOK) == 0) 1350 goto bad; 1351 break; 1352 case NI_QTYPE_NODEADDR: 1353 case NI_QTYPE_IPV4ADDR: 1354 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_NODEADDROK) == 0) 1355 goto bad; 1356 break; 1357 } 1358 1359 /* guess reply length */ 1360 switch (qtype) { 1361 case NI_QTYPE_NOOP: 1362 break; /* no reply data */ 1363 case NI_QTYPE_SUPTYPES: 1364 replylen += sizeof(u_int32_t); 1365 break; 1366 case NI_QTYPE_FQDN: 1367 /* XXX will append an mbuf */ 1368 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); 1369 break; 1370 case NI_QTYPE_NODEADDR: 1371 addrs = ni6_addrs(ni6, m, &ifp, (struct in6_addr *)subj); 1372 if ((replylen += addrs * (sizeof(struct in6_addr) + 1373 sizeof(u_int32_t))) > MCLBYTES) 1374 replylen = MCLBYTES; /* XXX: will truncate pkt later */ 1375 break; 1376 case NI_QTYPE_IPV4ADDR: 1377 /* unsupported - should respond with unknown Qtype? */ 1378 break; 1379 default: 1380 /* 1381 * XXX: We must return a reply with the ICMP6 code 1382 * `unknown Qtype' in this case. However we regard the case 1383 * as an FQDN query for backward compatibility. 1384 * Older versions set a random value to this field, 1385 * so it rarely varies in the defined qtypes. 1386 * But the mechanism is not reliable... 1387 * maybe we should obsolete older versions. 1388 */ 1389 qtype = NI_QTYPE_FQDN; 1390 /* XXX will append an mbuf */ 1391 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); 1392 oldfqdn++; 1393 break; 1394 } 1395 1396 /* Allocate an mbuf to reply. */ 1397 if (replylen > MCLBYTES) { 1398 /* 1399 * XXX: should we try to allocate more? But MCLBYTES 1400 * is probably much larger than IPV6_MMTU... 1401 */ 1402 goto bad; 1403 } 1404 if (replylen > MHLEN) 1405 n = m_getcl(M_NOWAIT, m->m_type, M_PKTHDR); 1406 else 1407 n = m_gethdr(M_NOWAIT, m->m_type); 1408 if (n == NULL) { 1409 m_freem(m); 1410 return (NULL); 1411 } 1412 m_move_pkthdr(n, m); /* just for recvif and FIB */ 1413 n->m_pkthdr.len = n->m_len = replylen; 1414 1415 /* copy mbuf header and IPv6 + Node Information base headers */ 1416 bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr)); 1417 nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1); 1418 bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo)); 1419 1420 /* qtype dependent procedure */ 1421 switch (qtype) { 1422 case NI_QTYPE_NOOP: 1423 nni6->ni_code = ICMP6_NI_SUCCESS; 1424 nni6->ni_flags = 0; 1425 break; 1426 case NI_QTYPE_SUPTYPES: 1427 { 1428 u_int32_t v; 1429 nni6->ni_code = ICMP6_NI_SUCCESS; 1430 nni6->ni_flags = htons(0x0000); /* raw bitmap */ 1431 /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */ 1432 v = (u_int32_t)htonl(0x0000000f); 1433 bcopy(&v, nni6 + 1, sizeof(u_int32_t)); 1434 break; 1435 } 1436 case NI_QTYPE_FQDN: 1437 nni6->ni_code = ICMP6_NI_SUCCESS; 1438 fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) + 1439 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo)); 1440 nni6->ni_flags = 0; /* XXX: meaningless TTL */ 1441 fqdn->ni_fqdn_ttl = 0; /* ditto. */ 1442 /* 1443 * XXX do we really have FQDN in hostname? 1444 */ 1445 mtx_lock(&pr->pr_mtx); 1446 n->m_next = ni6_nametodns(pr->pr_hostname, 1447 strlen(pr->pr_hostname), oldfqdn); 1448 mtx_unlock(&pr->pr_mtx); 1449 if (n->m_next == NULL) 1450 goto bad; 1451 /* XXX we assume that n->m_next is not a chain */ 1452 if (n->m_next->m_next != NULL) 1453 goto bad; 1454 n->m_pkthdr.len += n->m_next->m_len; 1455 break; 1456 case NI_QTYPE_NODEADDR: 1457 { 1458 int lenlim, copied; 1459 1460 nni6->ni_code = ICMP6_NI_SUCCESS; 1461 n->m_pkthdr.len = n->m_len = 1462 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); 1463 lenlim = M_TRAILINGSPACE(n); 1464 copied = ni6_store_addrs(ni6, nni6, ifp, lenlim); 1465 /* XXX: reset mbuf length */ 1466 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + 1467 sizeof(struct icmp6_nodeinfo) + copied; 1468 break; 1469 } 1470 default: 1471 break; /* XXX impossible! */ 1472 } 1473 1474 nni6->ni_type = ICMP6_NI_REPLY; 1475 m_freem(m); 1476 return (n); 1477 1478 bad: 1479 m_freem(m); 1480 if (n) 1481 m_freem(n); 1482 return (NULL); 1483 } 1484 1485 /* 1486 * make a mbuf with DNS-encoded string. no compression support. 1487 * 1488 * XXX names with less than 2 dots (like "foo" or "foo.section") will be 1489 * treated as truncated name (two \0 at the end). this is a wild guess. 1490 * 1491 * old - return pascal string if non-zero 1492 */ 1493 static struct mbuf * 1494 ni6_nametodns(const char *name, int namelen, int old) 1495 { 1496 struct mbuf *m; 1497 char *cp, *ep; 1498 const char *p, *q; 1499 int i, len, nterm; 1500 1501 if (old) 1502 len = namelen + 1; 1503 else 1504 len = MCLBYTES; 1505 1506 /* Because MAXHOSTNAMELEN is usually 256, we use cluster mbuf. */ 1507 if (len > MLEN) 1508 m = m_getcl(M_NOWAIT, MT_DATA, 0); 1509 else 1510 m = m_get(M_NOWAIT, MT_DATA); 1511 if (m == NULL) 1512 goto fail; 1513 1514 if (old) { 1515 m->m_len = len; 1516 *mtod(m, char *) = namelen; 1517 bcopy(name, mtod(m, char *) + 1, namelen); 1518 return m; 1519 } else { 1520 m->m_len = 0; 1521 cp = mtod(m, char *); 1522 ep = mtod(m, char *) + M_TRAILINGSPACE(m); 1523 1524 /* if not certain about my name, return empty buffer */ 1525 if (namelen == 0) 1526 return m; 1527 1528 /* 1529 * guess if it looks like shortened hostname, or FQDN. 1530 * shortened hostname needs two trailing "\0". 1531 */ 1532 i = 0; 1533 for (p = name; p < name + namelen; p++) { 1534 if (*p && *p == '.') 1535 i++; 1536 } 1537 if (i < 2) 1538 nterm = 2; 1539 else 1540 nterm = 1; 1541 1542 p = name; 1543 while (cp < ep && p < name + namelen) { 1544 i = 0; 1545 for (q = p; q < name + namelen && *q && *q != '.'; q++) 1546 i++; 1547 /* result does not fit into mbuf */ 1548 if (cp + i + 1 >= ep) 1549 goto fail; 1550 /* 1551 * DNS label length restriction, RFC1035 page 8. 1552 * "i == 0" case is included here to avoid returning 1553 * 0-length label on "foo..bar". 1554 */ 1555 if (i <= 0 || i >= 64) 1556 goto fail; 1557 *cp++ = i; 1558 bcopy(p, cp, i); 1559 cp += i; 1560 p = q; 1561 if (p < name + namelen && *p == '.') 1562 p++; 1563 } 1564 /* termination */ 1565 if (cp + nterm >= ep) 1566 goto fail; 1567 while (nterm-- > 0) 1568 *cp++ = '\0'; 1569 m->m_len = cp - mtod(m, char *); 1570 return m; 1571 } 1572 1573 panic("should not reach here"); 1574 /* NOTREACHED */ 1575 1576 fail: 1577 if (m) 1578 m_freem(m); 1579 return NULL; 1580 } 1581 1582 /* 1583 * check if two DNS-encoded string matches. takes care of truncated 1584 * form (with \0\0 at the end). no compression support. 1585 * XXX upper/lowercase match (see RFC2065) 1586 */ 1587 static int 1588 ni6_dnsmatch(const char *a, int alen, const char *b, int blen) 1589 { 1590 const char *a0, *b0; 1591 int l; 1592 1593 /* simplest case - need validation? */ 1594 if (alen == blen && bcmp(a, b, alen) == 0) 1595 return 1; 1596 1597 a0 = a; 1598 b0 = b; 1599 1600 /* termination is mandatory */ 1601 if (alen < 2 || blen < 2) 1602 return 0; 1603 if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0') 1604 return 0; 1605 alen--; 1606 blen--; 1607 1608 while (a - a0 < alen && b - b0 < blen) { 1609 if (a - a0 + 1 > alen || b - b0 + 1 > blen) 1610 return 0; 1611 1612 if ((signed char)a[0] < 0 || (signed char)b[0] < 0) 1613 return 0; 1614 /* we don't support compression yet */ 1615 if (a[0] >= 64 || b[0] >= 64) 1616 return 0; 1617 1618 /* truncated case */ 1619 if (a[0] == 0 && a - a0 == alen - 1) 1620 return 1; 1621 if (b[0] == 0 && b - b0 == blen - 1) 1622 return 1; 1623 if (a[0] == 0 || b[0] == 0) 1624 return 0; 1625 1626 if (a[0] != b[0]) 1627 return 0; 1628 l = a[0]; 1629 if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen) 1630 return 0; 1631 if (bcmp(a + 1, b + 1, l) != 0) 1632 return 0; 1633 1634 a += 1 + l; 1635 b += 1 + l; 1636 } 1637 1638 if (a - a0 == alen && b - b0 == blen) 1639 return 1; 1640 else 1641 return 0; 1642 } 1643 1644 /* 1645 * calculate the number of addresses to be returned in the node info reply. 1646 */ 1647 static int 1648 ni6_addrs(struct icmp6_nodeinfo *ni6, struct mbuf *m, struct ifnet **ifpp, 1649 struct in6_addr *subj) 1650 { 1651 struct ifnet *ifp; 1652 struct in6_ifaddr *ifa6; 1653 struct ifaddr *ifa; 1654 int addrs = 0, addrsofif, iffound = 0; 1655 int niflags = ni6->ni_flags; 1656 1657 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) { 1658 switch (ni6->ni_code) { 1659 case ICMP6_NI_SUBJ_IPV6: 1660 if (subj == NULL) /* must be impossible... */ 1661 return (0); 1662 break; 1663 default: 1664 /* 1665 * XXX: we only support IPv6 subject address for 1666 * this Qtype. 1667 */ 1668 return (0); 1669 } 1670 } 1671 1672 IFNET_RLOCK_NOSLEEP(); 1673 CK_STAILQ_FOREACH(ifp, &V_ifnet, if_link) { 1674 addrsofif = 0; 1675 IF_ADDR_RLOCK(ifp); 1676 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 1677 if (ifa->ifa_addr->sa_family != AF_INET6) 1678 continue; 1679 ifa6 = (struct in6_ifaddr *)ifa; 1680 1681 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 && 1682 IN6_ARE_ADDR_EQUAL(subj, &ifa6->ia_addr.sin6_addr)) 1683 iffound = 1; 1684 1685 /* 1686 * IPv4-mapped addresses can only be returned by a 1687 * Node Information proxy, since they represent 1688 * addresses of IPv4-only nodes, which perforce do 1689 * not implement this protocol. 1690 * [icmp-name-lookups-07, Section 5.4] 1691 * So we don't support NI_NODEADDR_FLAG_COMPAT in 1692 * this function at this moment. 1693 */ 1694 1695 /* What do we have to do about ::1? */ 1696 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { 1697 case IPV6_ADDR_SCOPE_LINKLOCAL: 1698 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) 1699 continue; 1700 break; 1701 case IPV6_ADDR_SCOPE_SITELOCAL: 1702 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) 1703 continue; 1704 break; 1705 case IPV6_ADDR_SCOPE_GLOBAL: 1706 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) 1707 continue; 1708 break; 1709 default: 1710 continue; 1711 } 1712 1713 /* 1714 * check if anycast is okay. 1715 * XXX: just experimental. not in the spec. 1716 */ 1717 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && 1718 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) 1719 continue; /* we need only unicast addresses */ 1720 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && 1721 (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) { 1722 continue; 1723 } 1724 addrsofif++; /* count the address */ 1725 } 1726 IF_ADDR_RUNLOCK(ifp); 1727 if (iffound) { 1728 *ifpp = ifp; 1729 IFNET_RUNLOCK_NOSLEEP(); 1730 return (addrsofif); 1731 } 1732 1733 addrs += addrsofif; 1734 } 1735 IFNET_RUNLOCK_NOSLEEP(); 1736 1737 return (addrs); 1738 } 1739 1740 static int 1741 ni6_store_addrs(struct icmp6_nodeinfo *ni6, struct icmp6_nodeinfo *nni6, 1742 struct ifnet *ifp0, int resid) 1743 { 1744 struct ifnet *ifp; 1745 struct in6_ifaddr *ifa6; 1746 struct ifaddr *ifa; 1747 struct ifnet *ifp_dep = NULL; 1748 int copied = 0, allow_deprecated = 0; 1749 u_char *cp = (u_char *)(nni6 + 1); 1750 int niflags = ni6->ni_flags; 1751 u_int32_t ltime; 1752 1753 if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL)) 1754 return (0); /* needless to copy */ 1755 1756 IFNET_RLOCK_NOSLEEP(); 1757 ifp = ifp0 ? ifp0 : CK_STAILQ_FIRST(&V_ifnet); 1758 again: 1759 1760 for (; ifp; ifp = CK_STAILQ_NEXT(ifp, if_link)) { 1761 IF_ADDR_RLOCK(ifp); 1762 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 1763 if (ifa->ifa_addr->sa_family != AF_INET6) 1764 continue; 1765 ifa6 = (struct in6_ifaddr *)ifa; 1766 1767 if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 && 1768 allow_deprecated == 0) { 1769 /* 1770 * prefererred address should be put before 1771 * deprecated addresses. 1772 */ 1773 1774 /* record the interface for later search */ 1775 if (ifp_dep == NULL) 1776 ifp_dep = ifp; 1777 1778 continue; 1779 } else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 && 1780 allow_deprecated != 0) 1781 continue; /* we now collect deprecated addrs */ 1782 1783 /* What do we have to do about ::1? */ 1784 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { 1785 case IPV6_ADDR_SCOPE_LINKLOCAL: 1786 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) 1787 continue; 1788 break; 1789 case IPV6_ADDR_SCOPE_SITELOCAL: 1790 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) 1791 continue; 1792 break; 1793 case IPV6_ADDR_SCOPE_GLOBAL: 1794 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) 1795 continue; 1796 break; 1797 default: 1798 continue; 1799 } 1800 1801 /* 1802 * check if anycast is okay. 1803 * XXX: just experimental. not in the spec. 1804 */ 1805 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && 1806 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) 1807 continue; 1808 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && 1809 (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) { 1810 continue; 1811 } 1812 1813 /* now we can copy the address */ 1814 if (resid < sizeof(struct in6_addr) + 1815 sizeof(u_int32_t)) { 1816 IF_ADDR_RUNLOCK(ifp); 1817 /* 1818 * We give up much more copy. 1819 * Set the truncate flag and return. 1820 */ 1821 nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE; 1822 IFNET_RUNLOCK_NOSLEEP(); 1823 return (copied); 1824 } 1825 1826 /* 1827 * Set the TTL of the address. 1828 * The TTL value should be one of the following 1829 * according to the specification: 1830 * 1831 * 1. The remaining lifetime of a DHCP lease on the 1832 * address, or 1833 * 2. The remaining Valid Lifetime of a prefix from 1834 * which the address was derived through Stateless 1835 * Autoconfiguration. 1836 * 1837 * Note that we currently do not support stateful 1838 * address configuration by DHCPv6, so the former 1839 * case can't happen. 1840 */ 1841 if (ifa6->ia6_lifetime.ia6t_expire == 0) 1842 ltime = ND6_INFINITE_LIFETIME; 1843 else { 1844 if (ifa6->ia6_lifetime.ia6t_expire > 1845 time_uptime) 1846 ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_uptime); 1847 else 1848 ltime = 0; 1849 } 1850 1851 bcopy(<ime, cp, sizeof(u_int32_t)); 1852 cp += sizeof(u_int32_t); 1853 1854 /* copy the address itself */ 1855 bcopy(&ifa6->ia_addr.sin6_addr, cp, 1856 sizeof(struct in6_addr)); 1857 in6_clearscope((struct in6_addr *)cp); /* XXX */ 1858 cp += sizeof(struct in6_addr); 1859 1860 resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t)); 1861 copied += (sizeof(struct in6_addr) + sizeof(u_int32_t)); 1862 } 1863 IF_ADDR_RUNLOCK(ifp); 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 IFNET_RUNLOCK_NOSLEEP(); 1876 1877 return (copied); 1878 } 1879 1880 /* 1881 * XXX almost dup'ed code with rip6_input. 1882 */ 1883 static int 1884 icmp6_rip6_input(struct mbuf **mp, int off) 1885 { 1886 struct mbuf *m = *mp; 1887 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1888 struct inpcb *inp; 1889 struct inpcb *last = NULL; 1890 struct sockaddr_in6 fromsa; 1891 struct icmp6_hdr *icmp6; 1892 struct epoch_tracker et; 1893 struct mbuf *opts = NULL; 1894 1895 /* This is assumed to be safe; icmp6_input() does a pullup. */ 1896 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off); 1897 1898 /* 1899 * XXX: the address may have embedded scope zone ID, which should be 1900 * hidden from applications. 1901 */ 1902 bzero(&fromsa, sizeof(fromsa)); 1903 fromsa.sin6_family = AF_INET6; 1904 fromsa.sin6_len = sizeof(struct sockaddr_in6); 1905 fromsa.sin6_addr = ip6->ip6_src; 1906 if (sa6_recoverscope(&fromsa)) { 1907 m_freem(m); 1908 *mp = NULL; 1909 return (IPPROTO_DONE); 1910 } 1911 1912 INP_INFO_RLOCK_ET(&V_ripcbinfo, et); 1913 CK_LIST_FOREACH(inp, &V_ripcb, inp_list) { 1914 if ((inp->inp_vflag & INP_IPV6) == 0) 1915 continue; 1916 if (inp->inp_ip_p != IPPROTO_ICMPV6) 1917 continue; 1918 if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr) && 1919 !IN6_ARE_ADDR_EQUAL(&inp->in6p_laddr, &ip6->ip6_dst)) 1920 continue; 1921 if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr) && 1922 !IN6_ARE_ADDR_EQUAL(&inp->in6p_faddr, &ip6->ip6_src)) 1923 continue; 1924 INP_RLOCK(inp); 1925 if (__predict_false(inp->inp_flags2 & INP_FREED)) { 1926 INP_RUNLOCK(inp); 1927 continue; 1928 } 1929 if (ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type, 1930 inp->in6p_icmp6filt)) { 1931 INP_RUNLOCK(inp); 1932 continue; 1933 } 1934 if (last != NULL) { 1935 struct mbuf *n = NULL; 1936 1937 /* 1938 * Recent network drivers tend to allocate a single 1939 * mbuf cluster, rather than to make a couple of 1940 * mbufs without clusters. Also, since the IPv6 code 1941 * path tries to avoid m_pullup(), it is highly 1942 * probable that we still have an mbuf cluster here 1943 * even though the necessary length can be stored in an 1944 * mbuf's internal buffer. 1945 * Meanwhile, the default size of the receive socket 1946 * buffer for raw sockets is not so large. This means 1947 * the possibility of packet loss is relatively higher 1948 * than before. To avoid this scenario, we copy the 1949 * received data to a separate mbuf that does not use 1950 * a cluster, if possible. 1951 * XXX: it is better to copy the data after stripping 1952 * intermediate headers. 1953 */ 1954 if ((m->m_flags & M_EXT) && m->m_next == NULL && 1955 m->m_len <= MHLEN) { 1956 n = m_get(M_NOWAIT, m->m_type); 1957 if (n != NULL) { 1958 if (m_dup_pkthdr(n, m, M_NOWAIT)) { 1959 bcopy(m->m_data, n->m_data, 1960 m->m_len); 1961 n->m_len = m->m_len; 1962 } else { 1963 m_free(n); 1964 n = NULL; 1965 } 1966 } 1967 } 1968 if (n != NULL || 1969 (n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) != NULL) { 1970 if (last->inp_flags & INP_CONTROLOPTS) 1971 ip6_savecontrol(last, n, &opts); 1972 /* strip intermediate headers */ 1973 m_adj(n, off); 1974 SOCKBUF_LOCK(&last->inp_socket->so_rcv); 1975 if (sbappendaddr_locked( 1976 &last->inp_socket->so_rcv, 1977 (struct sockaddr *)&fromsa, n, opts) 1978 == 0) { 1979 soroverflow_locked(last->inp_socket); 1980 m_freem(n); 1981 if (opts) { 1982 m_freem(opts); 1983 } 1984 } else 1985 sorwakeup_locked(last->inp_socket); 1986 opts = NULL; 1987 } 1988 INP_RUNLOCK(last); 1989 } 1990 last = inp; 1991 } 1992 INP_INFO_RUNLOCK_ET(&V_ripcbinfo, et); 1993 if (last != NULL) { 1994 if (last->inp_flags & INP_CONTROLOPTS) 1995 ip6_savecontrol(last, m, &opts); 1996 /* strip intermediate headers */ 1997 m_adj(m, off); 1998 1999 /* avoid using mbuf clusters if possible (see above) */ 2000 if ((m->m_flags & M_EXT) && m->m_next == NULL && 2001 m->m_len <= MHLEN) { 2002 struct mbuf *n; 2003 2004 n = m_get(M_NOWAIT, m->m_type); 2005 if (n != NULL) { 2006 if (m_dup_pkthdr(n, m, M_NOWAIT)) { 2007 bcopy(m->m_data, n->m_data, m->m_len); 2008 n->m_len = m->m_len; 2009 2010 m_freem(m); 2011 m = n; 2012 } else { 2013 m_freem(n); 2014 n = NULL; 2015 } 2016 } 2017 } 2018 SOCKBUF_LOCK(&last->inp_socket->so_rcv); 2019 if (sbappendaddr_locked(&last->inp_socket->so_rcv, 2020 (struct sockaddr *)&fromsa, m, opts) == 0) { 2021 m_freem(m); 2022 if (opts) 2023 m_freem(opts); 2024 soroverflow_locked(last->inp_socket); 2025 } else 2026 sorwakeup_locked(last->inp_socket); 2027 INP_RUNLOCK(last); 2028 } else { 2029 m_freem(m); 2030 IP6STAT_DEC(ip6s_delivered); 2031 } 2032 *mp = NULL; 2033 return (IPPROTO_DONE); 2034 } 2035 2036 /* 2037 * Reflect the ip6 packet back to the source. 2038 * OFF points to the icmp6 header, counted from the top of the mbuf. 2039 */ 2040 void 2041 icmp6_reflect(struct mbuf *m, size_t off) 2042 { 2043 struct in6_addr src6, *srcp; 2044 struct ip6_hdr *ip6; 2045 struct icmp6_hdr *icmp6; 2046 struct in6_ifaddr *ia = NULL; 2047 struct ifnet *outif = NULL; 2048 int plen; 2049 int type, code, hlim; 2050 2051 /* too short to reflect */ 2052 if (off < sizeof(struct ip6_hdr)) { 2053 nd6log((LOG_DEBUG, 2054 "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n", 2055 (u_long)off, (u_long)sizeof(struct ip6_hdr), 2056 __FILE__, __LINE__)); 2057 goto bad; 2058 } 2059 2060 /* 2061 * If there are extra headers between IPv6 and ICMPv6, strip 2062 * off that header first. 2063 */ 2064 #ifdef DIAGNOSTIC 2065 if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN) 2066 panic("assumption failed in icmp6_reflect"); 2067 #endif 2068 if (off > sizeof(struct ip6_hdr)) { 2069 size_t l; 2070 struct ip6_hdr nip6; 2071 2072 l = off - sizeof(struct ip6_hdr); 2073 m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6); 2074 m_adj(m, l); 2075 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 2076 if (m->m_len < l) { 2077 if ((m = m_pullup(m, l)) == NULL) 2078 return; 2079 } 2080 bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6)); 2081 } else /* off == sizeof(struct ip6_hdr) */ { 2082 size_t l; 2083 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 2084 if (m->m_len < l) { 2085 if ((m = m_pullup(m, l)) == NULL) 2086 return; 2087 } 2088 } 2089 plen = m->m_pkthdr.len - sizeof(struct ip6_hdr); 2090 ip6 = mtod(m, struct ip6_hdr *); 2091 ip6->ip6_nxt = IPPROTO_ICMPV6; 2092 icmp6 = (struct icmp6_hdr *)(ip6 + 1); 2093 type = icmp6->icmp6_type; /* keep type for statistics */ 2094 code = icmp6->icmp6_code; /* ditto. */ 2095 hlim = 0; 2096 srcp = NULL; 2097 2098 /* 2099 * If the incoming packet was addressed directly to us (i.e. unicast), 2100 * use dst as the src for the reply. 2101 * The IN6_IFF_NOTREADY case should be VERY rare, but is possible 2102 * (for example) when we encounter an error while forwarding procedure 2103 * destined to a duplicated address of ours. 2104 */ 2105 if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 2106 ia = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */); 2107 if (ia != NULL && !(ia->ia6_flags & 2108 (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) { 2109 src6 = ia->ia_addr.sin6_addr; 2110 srcp = &src6; 2111 2112 if (m->m_pkthdr.rcvif != NULL) { 2113 /* XXX: This may not be the outgoing interface */ 2114 hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim; 2115 } else 2116 hlim = V_ip6_defhlim; 2117 } 2118 if (ia != NULL) 2119 ifa_free(&ia->ia_ifa); 2120 } 2121 2122 if (srcp == NULL) { 2123 int error; 2124 struct in6_addr dst6; 2125 uint32_t scopeid; 2126 2127 /* 2128 * This case matches to multicasts, our anycast, or unicasts 2129 * that we do not own. Select a source address based on the 2130 * source address of the erroneous packet. 2131 */ 2132 in6_splitscope(&ip6->ip6_src, &dst6, &scopeid); 2133 error = in6_selectsrc_addr(M_GETFIB(m), &dst6, 2134 scopeid, NULL, &src6, &hlim); 2135 2136 if (error) { 2137 char ip6buf[INET6_ADDRSTRLEN]; 2138 nd6log((LOG_DEBUG, 2139 "icmp6_reflect: source can't be determined: " 2140 "dst=%s, error=%d\n", 2141 ip6_sprintf(ip6buf, &ip6->ip6_dst), error)); 2142 goto bad; 2143 } 2144 srcp = &src6; 2145 } 2146 /* 2147 * ip6_input() drops a packet if its src is multicast. 2148 * So, the src is never multicast. 2149 */ 2150 ip6->ip6_dst = ip6->ip6_src; 2151 ip6->ip6_src = *srcp; 2152 ip6->ip6_flow = 0; 2153 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2154 ip6->ip6_vfc |= IPV6_VERSION; 2155 ip6->ip6_nxt = IPPROTO_ICMPV6; 2156 ip6->ip6_hlim = hlim; 2157 2158 icmp6->icmp6_cksum = 0; 2159 icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2160 sizeof(struct ip6_hdr), plen); 2161 2162 /* 2163 * XXX option handling 2164 */ 2165 2166 m->m_flags &= ~(M_BCAST|M_MCAST); 2167 m->m_pkthdr.rcvif = NULL; 2168 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2169 if (outif) 2170 icmp6_ifoutstat_inc(outif, type, code); 2171 2172 return; 2173 2174 bad: 2175 m_freem(m); 2176 return; 2177 } 2178 2179 void 2180 icmp6_fasttimo(void) 2181 { 2182 2183 mld_fasttimo(); 2184 } 2185 2186 void 2187 icmp6_slowtimo(void) 2188 { 2189 2190 mld_slowtimo(); 2191 } 2192 2193 static const char * 2194 icmp6_redirect_diag(struct in6_addr *src6, struct in6_addr *dst6, 2195 struct in6_addr *tgt6) 2196 { 2197 static char buf[1024]; 2198 char ip6bufs[INET6_ADDRSTRLEN]; 2199 char ip6bufd[INET6_ADDRSTRLEN]; 2200 char ip6buft[INET6_ADDRSTRLEN]; 2201 snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)", 2202 ip6_sprintf(ip6bufs, src6), ip6_sprintf(ip6bufd, dst6), 2203 ip6_sprintf(ip6buft, tgt6)); 2204 return buf; 2205 } 2206 2207 void 2208 icmp6_redirect_input(struct mbuf *m, int off) 2209 { 2210 struct ifnet *ifp; 2211 struct ip6_hdr *ip6; 2212 struct nd_redirect *nd_rd; 2213 struct in6_addr src6, redtgt6, reddst6; 2214 union nd_opts ndopts; 2215 char ip6buf[INET6_ADDRSTRLEN]; 2216 char *lladdr; 2217 int icmp6len, is_onlink, is_router, lladdrlen; 2218 2219 M_ASSERTPKTHDR(m); 2220 KASSERT(m->m_pkthdr.rcvif != NULL, ("%s: no rcvif", __func__)); 2221 2222 /* XXX if we are router, we don't update route by icmp6 redirect */ 2223 if (V_ip6_forwarding) 2224 goto freeit; 2225 if (!V_icmp6_rediraccept) 2226 goto freeit; 2227 2228 /* RFC 6980: Nodes MUST silently ignore fragments */ 2229 if(m->m_flags & M_FRAGMENTED) 2230 goto freeit; 2231 2232 ip6 = mtod(m, struct ip6_hdr *); 2233 icmp6len = ntohs(ip6->ip6_plen); 2234 if (m->m_len < off + icmp6len) { 2235 m = m_pullup(m, off + icmp6len); 2236 if (m == NULL) { 2237 IP6STAT_INC(ip6s_exthdrtoolong); 2238 return; 2239 } 2240 } 2241 ip6 = mtod(m, struct ip6_hdr *); 2242 nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off); 2243 2244 ifp = m->m_pkthdr.rcvif; 2245 redtgt6 = nd_rd->nd_rd_target; 2246 reddst6 = nd_rd->nd_rd_dst; 2247 2248 if (in6_setscope(&redtgt6, ifp, NULL) || 2249 in6_setscope(&reddst6, ifp, NULL)) { 2250 goto freeit; 2251 } 2252 2253 /* validation */ 2254 src6 = ip6->ip6_src; 2255 if (!IN6_IS_ADDR_LINKLOCAL(&src6)) { 2256 nd6log((LOG_ERR, 2257 "ICMP6 redirect sent from %s rejected; " 2258 "must be from linklocal\n", 2259 ip6_sprintf(ip6buf, &src6))); 2260 goto bad; 2261 } 2262 if (ip6->ip6_hlim != 255) { 2263 nd6log((LOG_ERR, 2264 "ICMP6 redirect sent from %s rejected; " 2265 "hlim=%d (must be 255)\n", 2266 ip6_sprintf(ip6buf, &src6), ip6->ip6_hlim)); 2267 goto bad; 2268 } 2269 { 2270 /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */ 2271 struct nhop6_basic nh6; 2272 struct in6_addr kdst; 2273 uint32_t scopeid; 2274 2275 in6_splitscope(&reddst6, &kdst, &scopeid); 2276 if (fib6_lookup_nh_basic(ifp->if_fib, &kdst, scopeid, 0, 0,&nh6)==0){ 2277 if ((nh6.nh_flags & NHF_GATEWAY) == 0) { 2278 nd6log((LOG_ERR, 2279 "ICMP6 redirect rejected; no route " 2280 "with inet6 gateway found for redirect dst: %s\n", 2281 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2282 goto bad; 2283 } 2284 2285 /* 2286 * Embed scope zone id into next hop address, since 2287 * fib6_lookup_nh_basic() returns address without embedded 2288 * scope zone id. 2289 */ 2290 if (in6_setscope(&nh6.nh_addr, m->m_pkthdr.rcvif, NULL)) 2291 goto freeit; 2292 2293 if (IN6_ARE_ADDR_EQUAL(&src6, &nh6.nh_addr) == 0) { 2294 nd6log((LOG_ERR, 2295 "ICMP6 redirect rejected; " 2296 "not equal to gw-for-src=%s (must be same): " 2297 "%s\n", 2298 ip6_sprintf(ip6buf, &nh6.nh_addr), 2299 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2300 goto bad; 2301 } 2302 } else { 2303 nd6log((LOG_ERR, 2304 "ICMP6 redirect rejected; " 2305 "no route found for redirect dst: %s\n", 2306 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2307 goto bad; 2308 } 2309 } 2310 if (IN6_IS_ADDR_MULTICAST(&reddst6)) { 2311 nd6log((LOG_ERR, 2312 "ICMP6 redirect rejected; " 2313 "redirect dst must be unicast: %s\n", 2314 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2315 goto bad; 2316 } 2317 2318 is_router = is_onlink = 0; 2319 if (IN6_IS_ADDR_LINKLOCAL(&redtgt6)) 2320 is_router = 1; /* router case */ 2321 if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0) 2322 is_onlink = 1; /* on-link destination case */ 2323 if (!is_router && !is_onlink) { 2324 nd6log((LOG_ERR, 2325 "ICMP6 redirect rejected; " 2326 "neither router case nor onlink case: %s\n", 2327 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2328 goto bad; 2329 } 2330 2331 icmp6len -= sizeof(*nd_rd); 2332 nd6_option_init(nd_rd + 1, icmp6len, &ndopts); 2333 if (nd6_options(&ndopts) < 0) { 2334 nd6log((LOG_INFO, "%s: invalid ND option, rejected: %s\n", 2335 __func__, icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2336 /* nd6_options have incremented stats */ 2337 goto freeit; 2338 } 2339 2340 lladdr = NULL; 2341 lladdrlen = 0; 2342 if (ndopts.nd_opts_tgt_lladdr) { 2343 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 2344 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 2345 } 2346 2347 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 2348 nd6log((LOG_INFO, "%s: lladdrlen mismatch for %s " 2349 "(if %d, icmp6 packet %d): %s\n", 2350 __func__, ip6_sprintf(ip6buf, &redtgt6), 2351 ifp->if_addrlen, lladdrlen - 2, 2352 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2353 goto bad; 2354 } 2355 2356 /* Validation passed. */ 2357 2358 /* RFC 2461 8.3 */ 2359 nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT, 2360 is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER); 2361 2362 /* 2363 * Install a gateway route in the better-router case or an interface 2364 * route in the on-link-destination case. 2365 */ 2366 { 2367 struct sockaddr_in6 sdst; 2368 struct sockaddr_in6 sgw; 2369 struct sockaddr_in6 ssrc; 2370 struct sockaddr *gw; 2371 int rt_flags; 2372 u_int fibnum; 2373 2374 bzero(&sdst, sizeof(sdst)); 2375 bzero(&ssrc, sizeof(ssrc)); 2376 sdst.sin6_family = ssrc.sin6_family = AF_INET6; 2377 sdst.sin6_len = ssrc.sin6_len = sizeof(struct sockaddr_in6); 2378 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr)); 2379 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr)); 2380 rt_flags = RTF_HOST; 2381 if (is_router) { 2382 bzero(&sgw, sizeof(sgw)); 2383 sgw.sin6_family = AF_INET6; 2384 sgw.sin6_len = sizeof(struct sockaddr_in6); 2385 bcopy(&redtgt6, &sgw.sin6_addr, 2386 sizeof(struct in6_addr)); 2387 gw = (struct sockaddr *)&sgw; 2388 rt_flags |= RTF_GATEWAY; 2389 } else 2390 gw = ifp->if_addr->ifa_addr; 2391 for (fibnum = 0; fibnum < rt_numfibs; fibnum++) 2392 in6_rtredirect((struct sockaddr *)&sdst, gw, 2393 (struct sockaddr *)NULL, rt_flags, 2394 (struct sockaddr *)&ssrc, fibnum); 2395 } 2396 /* finally update cached route in each socket via pfctlinput */ 2397 { 2398 struct sockaddr_in6 sdst; 2399 2400 bzero(&sdst, sizeof(sdst)); 2401 sdst.sin6_family = AF_INET6; 2402 sdst.sin6_len = sizeof(struct sockaddr_in6); 2403 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr)); 2404 pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst); 2405 } 2406 2407 freeit: 2408 m_freem(m); 2409 return; 2410 2411 bad: 2412 ICMP6STAT_INC(icp6s_badredirect); 2413 m_freem(m); 2414 } 2415 2416 void 2417 icmp6_redirect_output(struct mbuf *m0, struct rtentry *rt) 2418 { 2419 struct ifnet *ifp; /* my outgoing interface */ 2420 struct in6_addr *ifp_ll6; 2421 struct in6_addr *router_ll6; 2422 struct ip6_hdr *sip6; /* m0 as struct ip6_hdr */ 2423 struct mbuf *m = NULL; /* newly allocated one */ 2424 struct m_tag *mtag; 2425 struct ip6_hdr *ip6; /* m as struct ip6_hdr */ 2426 struct nd_redirect *nd_rd; 2427 struct llentry *ln = NULL; 2428 size_t maxlen; 2429 u_char *p; 2430 struct ifnet *outif = NULL; 2431 struct sockaddr_in6 src_sa; 2432 2433 icmp6_errcount(ND_REDIRECT, 0); 2434 2435 /* if we are not router, we don't send icmp6 redirect */ 2436 if (!V_ip6_forwarding) 2437 goto fail; 2438 2439 /* sanity check */ 2440 if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp)) 2441 goto fail; 2442 2443 /* 2444 * Address check: 2445 * the source address must identify a neighbor, and 2446 * the destination address must not be a multicast address 2447 * [RFC 2461, sec 8.2] 2448 */ 2449 sip6 = mtod(m0, struct ip6_hdr *); 2450 bzero(&src_sa, sizeof(src_sa)); 2451 src_sa.sin6_family = AF_INET6; 2452 src_sa.sin6_len = sizeof(src_sa); 2453 src_sa.sin6_addr = sip6->ip6_src; 2454 if (nd6_is_addr_neighbor(&src_sa, ifp) == 0) 2455 goto fail; 2456 if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst)) 2457 goto fail; /* what should we do here? */ 2458 2459 /* rate limit */ 2460 if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0)) 2461 goto fail; 2462 2463 /* 2464 * Since we are going to append up to 1280 bytes (= IPV6_MMTU), 2465 * we almost always ask for an mbuf cluster for simplicity. 2466 * (MHLEN < IPV6_MMTU is almost always true) 2467 */ 2468 #if IPV6_MMTU >= MCLBYTES 2469 # error assumption failed about IPV6_MMTU and MCLBYTES 2470 #endif 2471 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 2472 if (m == NULL) 2473 goto fail; 2474 M_SETFIB(m, rt->rt_fibnum); 2475 maxlen = M_TRAILINGSPACE(m); 2476 maxlen = min(IPV6_MMTU, maxlen); 2477 /* just for safety */ 2478 if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) + 2479 ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) { 2480 goto fail; 2481 } 2482 2483 { 2484 /* get ip6 linklocal address for ifp(my outgoing interface). */ 2485 struct in6_ifaddr *ia; 2486 if ((ia = in6ifa_ifpforlinklocal(ifp, 2487 IN6_IFF_NOTREADY| 2488 IN6_IFF_ANYCAST)) == NULL) 2489 goto fail; 2490 ifp_ll6 = &ia->ia_addr.sin6_addr; 2491 /* XXXRW: reference released prematurely. */ 2492 ifa_free(&ia->ia_ifa); 2493 } 2494 2495 /* get ip6 linklocal address for the router. */ 2496 if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) { 2497 struct sockaddr_in6 *sin6; 2498 sin6 = (struct sockaddr_in6 *)rt->rt_gateway; 2499 router_ll6 = &sin6->sin6_addr; 2500 if (!IN6_IS_ADDR_LINKLOCAL(router_ll6)) 2501 router_ll6 = (struct in6_addr *)NULL; 2502 } else 2503 router_ll6 = (struct in6_addr *)NULL; 2504 2505 /* ip6 */ 2506 ip6 = mtod(m, struct ip6_hdr *); 2507 ip6->ip6_flow = 0; 2508 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2509 ip6->ip6_vfc |= IPV6_VERSION; 2510 /* ip6->ip6_plen will be set later */ 2511 ip6->ip6_nxt = IPPROTO_ICMPV6; 2512 ip6->ip6_hlim = 255; 2513 /* ip6->ip6_src must be linklocal addr for my outgoing if. */ 2514 bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr)); 2515 bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr)); 2516 2517 /* ND Redirect */ 2518 nd_rd = (struct nd_redirect *)(ip6 + 1); 2519 nd_rd->nd_rd_type = ND_REDIRECT; 2520 nd_rd->nd_rd_code = 0; 2521 nd_rd->nd_rd_reserved = 0; 2522 if (rt->rt_flags & RTF_GATEWAY) { 2523 /* 2524 * nd_rd->nd_rd_target must be a link-local address in 2525 * better router cases. 2526 */ 2527 if (!router_ll6) 2528 goto fail; 2529 bcopy(router_ll6, &nd_rd->nd_rd_target, 2530 sizeof(nd_rd->nd_rd_target)); 2531 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2532 sizeof(nd_rd->nd_rd_dst)); 2533 } else { 2534 /* make sure redtgt == reddst */ 2535 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target, 2536 sizeof(nd_rd->nd_rd_target)); 2537 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2538 sizeof(nd_rd->nd_rd_dst)); 2539 } 2540 2541 p = (u_char *)(nd_rd + 1); 2542 2543 if (!router_ll6) 2544 goto nolladdropt; 2545 2546 { 2547 /* target lladdr option */ 2548 int len; 2549 struct nd_opt_hdr *nd_opt; 2550 char *lladdr; 2551 2552 IF_AFDATA_RLOCK(ifp); 2553 ln = nd6_lookup(router_ll6, 0, ifp); 2554 IF_AFDATA_RUNLOCK(ifp); 2555 if (ln == NULL) 2556 goto nolladdropt; 2557 2558 len = sizeof(*nd_opt) + ifp->if_addrlen; 2559 len = (len + 7) & ~7; /* round by 8 */ 2560 /* safety check */ 2561 if (len + (p - (u_char *)ip6) > maxlen) 2562 goto nolladdropt; 2563 2564 if (ln->la_flags & LLE_VALID) { 2565 nd_opt = (struct nd_opt_hdr *)p; 2566 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 2567 nd_opt->nd_opt_len = len >> 3; 2568 lladdr = (char *)(nd_opt + 1); 2569 bcopy(ln->ll_addr, lladdr, ifp->if_addrlen); 2570 p += len; 2571 } 2572 } 2573 nolladdropt: 2574 if (ln != NULL) 2575 LLE_RUNLOCK(ln); 2576 2577 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2578 2579 /* just to be safe */ 2580 #ifdef M_DECRYPTED /*not openbsd*/ 2581 if (m0->m_flags & M_DECRYPTED) 2582 goto noredhdropt; 2583 #endif 2584 if (p - (u_char *)ip6 > maxlen) 2585 goto noredhdropt; 2586 2587 { 2588 /* redirected header option */ 2589 int len; 2590 struct nd_opt_rd_hdr *nd_opt_rh; 2591 2592 /* 2593 * compute the maximum size for icmp6 redirect header option. 2594 * XXX room for auth header? 2595 */ 2596 len = maxlen - (p - (u_char *)ip6); 2597 len &= ~7; 2598 2599 /* This is just for simplicity. */ 2600 if (m0->m_pkthdr.len != m0->m_len) { 2601 if (m0->m_next) { 2602 m_freem(m0->m_next); 2603 m0->m_next = NULL; 2604 } 2605 m0->m_pkthdr.len = m0->m_len; 2606 } 2607 2608 /* 2609 * Redirected header option spec (RFC2461 4.6.3) talks nothing 2610 * about padding/truncate rule for the original IP packet. 2611 * From the discussion on IPv6imp in Feb 1999, 2612 * the consensus was: 2613 * - "attach as much as possible" is the goal 2614 * - pad if not aligned (original size can be guessed by 2615 * original ip6 header) 2616 * Following code adds the padding if it is simple enough, 2617 * and truncates if not. 2618 */ 2619 if (m0->m_next || m0->m_pkthdr.len != m0->m_len) 2620 panic("assumption failed in %s:%d", __FILE__, 2621 __LINE__); 2622 2623 if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) { 2624 /* not enough room, truncate */ 2625 m0->m_pkthdr.len = m0->m_len = len - 2626 sizeof(*nd_opt_rh); 2627 } else { 2628 /* enough room, pad or truncate */ 2629 size_t extra; 2630 2631 extra = m0->m_pkthdr.len % 8; 2632 if (extra) { 2633 /* pad if easy enough, truncate if not */ 2634 if (8 - extra <= M_TRAILINGSPACE(m0)) { 2635 /* pad */ 2636 m0->m_len += (8 - extra); 2637 m0->m_pkthdr.len += (8 - extra); 2638 } else { 2639 /* truncate */ 2640 m0->m_pkthdr.len -= extra; 2641 m0->m_len -= extra; 2642 } 2643 } 2644 len = m0->m_pkthdr.len + sizeof(*nd_opt_rh); 2645 m0->m_pkthdr.len = m0->m_len = len - 2646 sizeof(*nd_opt_rh); 2647 } 2648 2649 nd_opt_rh = (struct nd_opt_rd_hdr *)p; 2650 bzero(nd_opt_rh, sizeof(*nd_opt_rh)); 2651 nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER; 2652 nd_opt_rh->nd_opt_rh_len = len >> 3; 2653 p += sizeof(*nd_opt_rh); 2654 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2655 2656 /* connect m0 to m */ 2657 m_tag_delete_chain(m0, NULL); 2658 m0->m_flags &= ~M_PKTHDR; 2659 m->m_next = m0; 2660 m->m_pkthdr.len = m->m_len + m0->m_len; 2661 m0 = NULL; 2662 } 2663 noredhdropt:; 2664 if (m0) { 2665 m_freem(m0); 2666 m0 = NULL; 2667 } 2668 2669 /* XXX: clear embedded link IDs in the inner header */ 2670 in6_clearscope(&sip6->ip6_src); 2671 in6_clearscope(&sip6->ip6_dst); 2672 in6_clearscope(&nd_rd->nd_rd_target); 2673 in6_clearscope(&nd_rd->nd_rd_dst); 2674 2675 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr)); 2676 2677 nd_rd->nd_rd_cksum = 0; 2678 nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2679 sizeof(*ip6), ntohs(ip6->ip6_plen)); 2680 2681 if (send_sendso_input_hook != NULL) { 2682 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, sizeof(unsigned short), 2683 M_NOWAIT); 2684 if (mtag == NULL) 2685 goto fail; 2686 *(unsigned short *)(mtag + 1) = nd_rd->nd_rd_type; 2687 m_tag_prepend(m, mtag); 2688 } 2689 2690 /* send the packet to outside... */ 2691 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2692 if (outif) { 2693 icmp6_ifstat_inc(outif, ifs6_out_msg); 2694 icmp6_ifstat_inc(outif, ifs6_out_redirect); 2695 } 2696 ICMP6STAT_INC(icp6s_outhist[ND_REDIRECT]); 2697 2698 return; 2699 2700 fail: 2701 if (m) 2702 m_freem(m); 2703 if (m0) 2704 m_freem(m0); 2705 } 2706 2707 /* 2708 * ICMPv6 socket option processing. 2709 */ 2710 int 2711 icmp6_ctloutput(struct socket *so, struct sockopt *sopt) 2712 { 2713 int error = 0; 2714 int optlen; 2715 struct inpcb *inp = sotoinpcb(so); 2716 int level, op, optname; 2717 2718 if (sopt) { 2719 level = sopt->sopt_level; 2720 op = sopt->sopt_dir; 2721 optname = sopt->sopt_name; 2722 optlen = sopt->sopt_valsize; 2723 } else 2724 level = op = optname = optlen = 0; 2725 2726 if (level != IPPROTO_ICMPV6) { 2727 return EINVAL; 2728 } 2729 2730 switch (op) { 2731 case PRCO_SETOPT: 2732 switch (optname) { 2733 case ICMP6_FILTER: 2734 { 2735 struct icmp6_filter ic6f; 2736 2737 if (optlen != sizeof(ic6f)) { 2738 error = EMSGSIZE; 2739 break; 2740 } 2741 error = sooptcopyin(sopt, &ic6f, optlen, optlen); 2742 if (error == 0) { 2743 INP_WLOCK(inp); 2744 *inp->in6p_icmp6filt = ic6f; 2745 INP_WUNLOCK(inp); 2746 } 2747 break; 2748 } 2749 2750 default: 2751 error = ENOPROTOOPT; 2752 break; 2753 } 2754 break; 2755 2756 case PRCO_GETOPT: 2757 switch (optname) { 2758 case ICMP6_FILTER: 2759 { 2760 struct icmp6_filter ic6f; 2761 2762 INP_RLOCK(inp); 2763 ic6f = *inp->in6p_icmp6filt; 2764 INP_RUNLOCK(inp); 2765 error = sooptcopyout(sopt, &ic6f, sizeof(ic6f)); 2766 break; 2767 } 2768 2769 default: 2770 error = ENOPROTOOPT; 2771 break; 2772 } 2773 break; 2774 } 2775 2776 return (error); 2777 } 2778 2779 /* 2780 * Perform rate limit check. 2781 * Returns 0 if it is okay to send the icmp6 packet. 2782 * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate 2783 * limitation. 2784 * 2785 * XXX per-destination/type check necessary? 2786 * 2787 * dst - not used at this moment 2788 * type - not used at this moment 2789 * code - not used at this moment 2790 */ 2791 static int 2792 icmp6_ratelimit(const struct in6_addr *dst, const int type, 2793 const int code) 2794 { 2795 int ret; 2796 2797 ret = 0; /* okay to send */ 2798 2799 /* PPS limit */ 2800 if (!ppsratecheck(&V_icmp6errppslim_last, &V_icmp6errpps_count, 2801 V_icmp6errppslim)) { 2802 /* The packet is subject to rate limit */ 2803 ret++; 2804 } 2805 2806 return ret; 2807 }
Cache object: 03fc1a0efa9bebc1ebcb368c158c851c
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