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 #ifndef PULLDOWN_TEST 236 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), ); 237 #else 238 if (m->m_len < sizeof(struct ip6_hdr)) { 239 m = m_pullup(m, sizeof(struct ip6_hdr)); 240 if (m == NULL) 241 return; 242 } 243 #endif 244 245 ip6 = mtod(m, struct ip6_hdr *); 246 247 if (in6_setscope(&ip6->ip6_src, ifp, NULL) != 0) 248 return; 249 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0) 250 return; 251 252 icmp6_error(m, type, code, param); 253 } 254 255 /* 256 * Generate an error packet of type error in response to bad IP6 packet. 257 */ 258 void 259 icmp6_error(struct mbuf *m, int type, int code, int param) 260 { 261 struct ip6_hdr *oip6, *nip6; 262 struct icmp6_hdr *icmp6; 263 u_int preplen; 264 int off; 265 int nxt; 266 267 ICMP6STAT_INC(icp6s_error); 268 269 /* count per-type-code statistics */ 270 icmp6_errcount(type, code); 271 272 #ifdef M_DECRYPTED /*not openbsd*/ 273 if (m->m_flags & M_DECRYPTED) { 274 ICMP6STAT_INC(icp6s_canterror); 275 goto freeit; 276 } 277 #endif 278 279 #ifndef PULLDOWN_TEST 280 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), ); 281 #else 282 if (m->m_len < sizeof(struct ip6_hdr)) { 283 m = m_pullup(m, sizeof(struct ip6_hdr)); 284 if (m == NULL) 285 return; 286 } 287 #endif 288 oip6 = mtod(m, struct ip6_hdr *); 289 290 /* 291 * If the destination address of the erroneous packet is a multicast 292 * address, or the packet was sent using link-layer multicast, 293 * we should basically suppress sending an error (RFC 2463, Section 294 * 2.4). 295 * We have two exceptions (the item e.2 in that section): 296 * - the Packet Too Big message can be sent for path MTU discovery. 297 * - the Parameter Problem Message that can be allowed an icmp6 error 298 * in the option type field. This check has been done in 299 * ip6_unknown_opt(), so we can just check the type and code. 300 */ 301 if ((m->m_flags & (M_BCAST|M_MCAST) || 302 IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) && 303 (type != ICMP6_PACKET_TOO_BIG && 304 (type != ICMP6_PARAM_PROB || 305 code != ICMP6_PARAMPROB_OPTION))) 306 goto freeit; 307 308 /* 309 * RFC 2463, 2.4 (e.5): source address check. 310 * XXX: the case of anycast source? 311 */ 312 if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) || 313 IN6_IS_ADDR_MULTICAST(&oip6->ip6_src)) 314 goto freeit; 315 316 /* 317 * If we are about to send ICMPv6 against ICMPv6 error/redirect, 318 * don't do it. 319 */ 320 nxt = -1; 321 off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt); 322 if (off >= 0 && nxt == IPPROTO_ICMPV6) { 323 struct icmp6_hdr *icp; 324 325 #ifndef PULLDOWN_TEST 326 IP6_EXTHDR_CHECK(m, 0, off + sizeof(struct icmp6_hdr), ); 327 icp = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 328 #else 329 IP6_EXTHDR_GET(icp, struct icmp6_hdr *, m, off, 330 sizeof(*icp)); 331 if (icp == NULL) { 332 ICMP6STAT_INC(icp6s_tooshort); 333 return; 334 } 335 #endif 336 if (icp->icmp6_type < ICMP6_ECHO_REQUEST || 337 icp->icmp6_type == ND_REDIRECT) { 338 /* 339 * ICMPv6 error 340 * Special case: for redirect (which is 341 * informational) we must not send icmp6 error. 342 */ 343 ICMP6STAT_INC(icp6s_canterror); 344 goto freeit; 345 } else { 346 /* ICMPv6 informational - send the error */ 347 } 348 } else { 349 /* non-ICMPv6 - send the error */ 350 } 351 352 oip6 = mtod(m, struct ip6_hdr *); /* adjust pointer */ 353 354 /* Finally, do rate limitation check. */ 355 if (icmp6_ratelimit(&oip6->ip6_src, type, code)) { 356 ICMP6STAT_INC(icp6s_toofreq); 357 goto freeit; 358 } 359 360 /* 361 * OK, ICMP6 can be generated. 362 */ 363 364 if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN) 365 m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len); 366 367 preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 368 M_PREPEND(m, preplen, M_NOWAIT); /* FIB is also copied over. */ 369 if (m == NULL) { 370 nd6log((LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__)); 371 return; 372 } 373 374 nip6 = mtod(m, struct ip6_hdr *); 375 nip6->ip6_src = oip6->ip6_src; 376 nip6->ip6_dst = oip6->ip6_dst; 377 378 in6_clearscope(&oip6->ip6_src); 379 in6_clearscope(&oip6->ip6_dst); 380 381 icmp6 = (struct icmp6_hdr *)(nip6 + 1); 382 icmp6->icmp6_type = type; 383 icmp6->icmp6_code = code; 384 icmp6->icmp6_pptr = htonl((u_int32_t)param); 385 386 ICMP6STAT_INC(icp6s_outhist[type]); 387 icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */ 388 389 return; 390 391 freeit: 392 /* 393 * If we can't tell whether or not we can generate ICMP6, free it. 394 */ 395 m_freem(m); 396 } 397 398 /* 399 * Process a received ICMP6 message. 400 */ 401 int 402 icmp6_input(struct mbuf **mp, int *offp, int proto) 403 { 404 struct mbuf *m, *n; 405 struct ifnet *ifp; 406 struct ip6_hdr *ip6, *nip6; 407 struct icmp6_hdr *icmp6, *nicmp6; 408 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 409 int code, error, icmp6len, ip6len, noff, off, sum; 410 411 m = *mp; 412 off = *offp; 413 414 #ifndef PULLDOWN_TEST 415 IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_hdr), IPPROTO_DONE); 416 /* m might change if M_LOOP. So, call mtod after this */ 417 #endif 418 419 /* 420 * Locate icmp6 structure in mbuf, and check 421 * that not corrupted and of at least minimum length 422 */ 423 424 icmp6len = m->m_pkthdr.len - off; 425 if (icmp6len < sizeof(struct icmp6_hdr)) { 426 ICMP6STAT_INC(icp6s_tooshort); 427 goto freeit; 428 } 429 430 ip6 = mtod(m, struct ip6_hdr *); 431 ifp = m->m_pkthdr.rcvif; 432 /* 433 * Check multicast group membership. 434 * Note: SSM filters are not applied for ICMPv6 traffic. 435 */ 436 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 437 struct in6_multi *inm; 438 439 inm = in6m_lookup(ifp, &ip6->ip6_dst); 440 if (inm == NULL) { 441 IP6STAT_INC(ip6s_notmember); 442 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 443 goto freeit; 444 } 445 } 446 447 /* Calculate the checksum. */ 448 #ifndef PULLDOWN_TEST 449 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off); 450 #else 451 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6)); 452 if (icmp6 == NULL) { 453 ICMP6STAT_INC(icp6s_tooshort); 454 return IPPROTO_DONE; 455 } 456 #endif 457 code = icmp6->icmp6_code; 458 459 if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) { 460 nd6log((LOG_ERR, 461 "ICMP6 checksum error(%d|%x) %s\n", 462 icmp6->icmp6_type, sum, 463 ip6_sprintf(ip6bufs, &ip6->ip6_src))); 464 ICMP6STAT_INC(icp6s_checksum); 465 goto freeit; 466 } 467 468 ICMP6STAT_INC(icp6s_inhist[icmp6->icmp6_type]); 469 icmp6_ifstat_inc(ifp, ifs6_in_msg); 470 if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK) 471 icmp6_ifstat_inc(ifp, ifs6_in_error); 472 473 ip6len = sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen); 474 switch (icmp6->icmp6_type) { 475 case ICMP6_DST_UNREACH: 476 icmp6_ifstat_inc(ifp, ifs6_in_dstunreach); 477 switch (code) { 478 case ICMP6_DST_UNREACH_NOROUTE: 479 case ICMP6_DST_UNREACH_ADDR: /* PRC_HOSTDEAD is a DOS */ 480 code = PRC_UNREACH_NET; 481 break; 482 case ICMP6_DST_UNREACH_ADMIN: 483 icmp6_ifstat_inc(ifp, ifs6_in_adminprohib); 484 code = PRC_UNREACH_ADMIN_PROHIB; 485 break; 486 case ICMP6_DST_UNREACH_BEYONDSCOPE: 487 /* I mean "source address was incorrect." */ 488 code = PRC_PARAMPROB; 489 break; 490 case ICMP6_DST_UNREACH_NOPORT: 491 code = PRC_UNREACH_PORT; 492 break; 493 default: 494 goto badcode; 495 } 496 goto deliver; 497 break; 498 499 case ICMP6_PACKET_TOO_BIG: 500 icmp6_ifstat_inc(ifp, ifs6_in_pkttoobig); 501 502 /* validation is made in icmp6_mtudisc_update */ 503 504 code = PRC_MSGSIZE; 505 506 /* 507 * Updating the path MTU will be done after examining 508 * intermediate extension headers. 509 */ 510 goto deliver; 511 break; 512 513 case ICMP6_TIME_EXCEEDED: 514 icmp6_ifstat_inc(ifp, ifs6_in_timeexceed); 515 switch (code) { 516 case ICMP6_TIME_EXCEED_TRANSIT: 517 code = PRC_TIMXCEED_INTRANS; 518 break; 519 case ICMP6_TIME_EXCEED_REASSEMBLY: 520 code = PRC_TIMXCEED_REASS; 521 break; 522 default: 523 goto badcode; 524 } 525 goto deliver; 526 break; 527 528 case ICMP6_PARAM_PROB: 529 icmp6_ifstat_inc(ifp, ifs6_in_paramprob); 530 switch (code) { 531 case ICMP6_PARAMPROB_NEXTHEADER: 532 code = PRC_UNREACH_PROTOCOL; 533 break; 534 case ICMP6_PARAMPROB_HEADER: 535 case ICMP6_PARAMPROB_OPTION: 536 code = PRC_PARAMPROB; 537 break; 538 default: 539 goto badcode; 540 } 541 goto deliver; 542 break; 543 544 case ICMP6_ECHO_REQUEST: 545 icmp6_ifstat_inc(ifp, ifs6_in_echo); 546 if (code != 0) 547 goto badcode; 548 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) { 549 /* Give up remote */ 550 break; 551 } 552 if (!M_WRITABLE(n) 553 || n->m_len < off + sizeof(struct icmp6_hdr)) { 554 struct mbuf *n0 = n; 555 int n0len; 556 557 CTASSERT(sizeof(*nip6) + sizeof(*nicmp6) <= MHLEN); 558 n = m_gethdr(M_NOWAIT, n0->m_type); 559 if (n == NULL) { 560 /* Give up remote */ 561 m_freem(n0); 562 break; 563 } 564 565 m_move_pkthdr(n, n0); /* FIB copied. */ 566 n0len = n0->m_pkthdr.len; /* save for use below */ 567 /* 568 * Copy IPv6 and ICMPv6 only. 569 */ 570 nip6 = mtod(n, struct ip6_hdr *); 571 bcopy(ip6, nip6, sizeof(struct ip6_hdr)); 572 nicmp6 = (struct icmp6_hdr *)(nip6 + 1); 573 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr)); 574 noff = sizeof(struct ip6_hdr); 575 /* new mbuf contains only ipv6+icmpv6 headers */ 576 n->m_len = noff + sizeof(struct icmp6_hdr); 577 /* 578 * Adjust mbuf. ip6_plen will be adjusted in 579 * ip6_output(). 580 */ 581 m_adj(n0, off + sizeof(struct icmp6_hdr)); 582 /* recalculate complete packet size */ 583 n->m_pkthdr.len = n0len + (noff - off); 584 n->m_next = n0; 585 } else { 586 IP6_EXTHDR_GET(nicmp6, struct icmp6_hdr *, n, off, 587 sizeof(*nicmp6)); 588 noff = off; 589 } 590 if (n) { 591 nicmp6->icmp6_type = ICMP6_ECHO_REPLY; 592 nicmp6->icmp6_code = 0; 593 ICMP6STAT_INC(icp6s_reflect); 594 ICMP6STAT_INC(icp6s_outhist[ICMP6_ECHO_REPLY]); 595 icmp6_reflect(n, noff); 596 } 597 break; 598 599 case ICMP6_ECHO_REPLY: 600 icmp6_ifstat_inc(ifp, ifs6_in_echoreply); 601 if (code != 0) 602 goto badcode; 603 break; 604 605 case MLD_LISTENER_QUERY: 606 case MLD_LISTENER_REPORT: 607 case MLD_LISTENER_DONE: 608 case MLDV2_LISTENER_REPORT: 609 /* 610 * Drop MLD traffic which is not link-local, has a hop limit 611 * of greater than 1 hop, or which does not have the 612 * IPv6 HBH Router Alert option. 613 * As IPv6 HBH options are stripped in ip6_input() we must 614 * check an mbuf header flag. 615 * XXX Should we also sanity check that these messages 616 * were directed to a link-local multicast prefix? 617 */ 618 if ((ip6->ip6_hlim != 1) || (m->m_flags & M_RTALERT_MLD) == 0) 619 goto freeit; 620 if (mld_input(m, off, icmp6len) != 0) { 621 *mp = NULL; 622 return (IPPROTO_DONE); 623 } 624 /* m stays. */ 625 break; 626 627 case ICMP6_WRUREQUEST: /* ICMP6_FQDN_QUERY */ 628 { 629 enum { WRU, FQDN } mode; 630 struct prison *pr; 631 632 if (!V_icmp6_nodeinfo) 633 break; 634 635 if (icmp6len == sizeof(struct icmp6_hdr) + 4) 636 mode = WRU; 637 else if (icmp6len >= sizeof(struct icmp6_nodeinfo)) 638 mode = FQDN; 639 else 640 goto badlen; 641 642 pr = NULL; 643 sx_slock(&allprison_lock); 644 TAILQ_FOREACH(pr, &allprison, pr_list) 645 if (pr->pr_vnet == ifp->if_vnet) 646 break; 647 sx_sunlock(&allprison_lock); 648 if (pr == NULL) 649 pr = curthread->td_ucred->cr_prison; 650 if (mode == FQDN) { 651 #ifndef PULLDOWN_TEST 652 IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_nodeinfo), 653 IPPROTO_DONE); 654 #endif 655 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 656 if (n) 657 n = ni6_input(n, off, pr); 658 /* XXX meaningless if n == NULL */ 659 noff = sizeof(struct ip6_hdr); 660 } else { 661 u_char *p; 662 int maxhlen, hlen; 663 664 /* 665 * XXX: this combination of flags is pointless, 666 * but should we keep this for compatibility? 667 */ 668 if ((V_icmp6_nodeinfo & (ICMP6_NODEINFO_FQDNOK | 669 ICMP6_NODEINFO_TMPADDROK)) != 670 (ICMP6_NODEINFO_FQDNOK | ICMP6_NODEINFO_TMPADDROK)) 671 break; 672 673 if (code != 0) 674 goto badcode; 675 676 CTASSERT(sizeof(*nip6) + sizeof(*nicmp6) + 4 <= MHLEN); 677 n = m_gethdr(M_NOWAIT, m->m_type); 678 if (n == NULL) { 679 /* Give up remote */ 680 break; 681 } 682 if (!m_dup_pkthdr(n, m, M_NOWAIT)) { 683 /* 684 * Previous code did a blind M_COPY_PKTHDR 685 * and said "just for rcvif". If true, then 686 * we could tolerate the dup failing (due to 687 * the deep copy of the tag chain). For now 688 * be conservative and just fail. 689 */ 690 m_free(n); 691 n = NULL; 692 break; 693 } 694 /* 695 * Copy IPv6 and ICMPv6 only. 696 */ 697 nip6 = mtod(n, struct ip6_hdr *); 698 bcopy(ip6, nip6, sizeof(struct ip6_hdr)); 699 nicmp6 = (struct icmp6_hdr *)(nip6 + 1); 700 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr)); 701 p = (u_char *)(nicmp6 + 1); 702 bzero(p, 4); 703 704 maxhlen = M_TRAILINGSPACE(n) - 705 (sizeof(*nip6) + sizeof(*nicmp6) + 4); 706 mtx_lock(&pr->pr_mtx); 707 hlen = strlen(pr->pr_hostname); 708 if (maxhlen > hlen) 709 maxhlen = hlen; 710 /* meaningless TTL */ 711 bcopy(pr->pr_hostname, p + 4, maxhlen); 712 mtx_unlock(&pr->pr_mtx); 713 noff = sizeof(struct ip6_hdr); 714 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + 715 sizeof(struct icmp6_hdr) + 4 + maxhlen; 716 nicmp6->icmp6_type = ICMP6_WRUREPLY; 717 nicmp6->icmp6_code = 0; 718 } 719 if (n) { 720 ICMP6STAT_INC(icp6s_reflect); 721 ICMP6STAT_INC(icp6s_outhist[ICMP6_WRUREPLY]); 722 icmp6_reflect(n, noff); 723 } 724 break; 725 } 726 727 case ICMP6_WRUREPLY: 728 if (code != 0) 729 goto badcode; 730 break; 731 732 case ND_ROUTER_SOLICIT: 733 icmp6_ifstat_inc(ifp, ifs6_in_routersolicit); 734 if (code != 0) 735 goto badcode; 736 if (icmp6len < sizeof(struct nd_router_solicit)) 737 goto badlen; 738 if (send_sendso_input_hook != NULL) { 739 IP6_EXTHDR_CHECK(m, off, icmp6len, IPPROTO_DONE); 740 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 741 if (error == 0) { 742 m = NULL; 743 goto freeit; 744 } 745 } 746 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 747 nd6_rs_input(m, off, icmp6len); 748 m = n; 749 if (m == NULL) 750 goto freeit; 751 break; 752 753 case ND_ROUTER_ADVERT: 754 icmp6_ifstat_inc(ifp, ifs6_in_routeradvert); 755 if (code != 0) 756 goto badcode; 757 if (icmp6len < sizeof(struct nd_router_advert)) 758 goto badlen; 759 if (send_sendso_input_hook != NULL) { 760 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 761 if (error == 0) { 762 m = NULL; 763 goto freeit; 764 } 765 } 766 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 767 nd6_ra_input(m, off, icmp6len); 768 m = n; 769 if (m == NULL) 770 goto freeit; 771 break; 772 773 case ND_NEIGHBOR_SOLICIT: 774 icmp6_ifstat_inc(ifp, ifs6_in_neighborsolicit); 775 if (code != 0) 776 goto badcode; 777 if (icmp6len < sizeof(struct nd_neighbor_solicit)) 778 goto badlen; 779 if (send_sendso_input_hook != NULL) { 780 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 781 if (error == 0) { 782 m = NULL; 783 goto freeit; 784 } 785 } 786 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 787 nd6_ns_input(m, off, icmp6len); 788 m = n; 789 if (m == NULL) 790 goto freeit; 791 break; 792 793 case ND_NEIGHBOR_ADVERT: 794 icmp6_ifstat_inc(ifp, ifs6_in_neighboradvert); 795 if (code != 0) 796 goto badcode; 797 if (icmp6len < sizeof(struct nd_neighbor_advert)) 798 goto badlen; 799 if (send_sendso_input_hook != NULL) { 800 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 801 if (error == 0) { 802 m = NULL; 803 goto freeit; 804 } 805 } 806 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 807 nd6_na_input(m, off, icmp6len); 808 m = n; 809 if (m == NULL) 810 goto freeit; 811 break; 812 813 case ND_REDIRECT: 814 icmp6_ifstat_inc(ifp, ifs6_in_redirect); 815 if (code != 0) 816 goto badcode; 817 if (icmp6len < sizeof(struct nd_redirect)) 818 goto badlen; 819 if (send_sendso_input_hook != NULL) { 820 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 821 if (error == 0) { 822 m = NULL; 823 goto freeit; 824 } 825 } 826 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 827 icmp6_redirect_input(m, off); 828 m = n; 829 if (m == NULL) 830 goto freeit; 831 break; 832 833 case ICMP6_ROUTER_RENUMBERING: 834 if (code != ICMP6_ROUTER_RENUMBERING_COMMAND && 835 code != ICMP6_ROUTER_RENUMBERING_RESULT) 836 goto badcode; 837 if (icmp6len < sizeof(struct icmp6_router_renum)) 838 goto badlen; 839 break; 840 841 default: 842 nd6log((LOG_DEBUG, 843 "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n", 844 icmp6->icmp6_type, ip6_sprintf(ip6bufs, &ip6->ip6_src), 845 ip6_sprintf(ip6bufd, &ip6->ip6_dst), 846 ifp ? ifp->if_index : 0)); 847 if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) { 848 /* ICMPv6 error: MUST deliver it by spec... */ 849 code = PRC_NCMDS; 850 /* deliver */ 851 } else { 852 /* ICMPv6 informational: MUST not deliver */ 853 break; 854 } 855 deliver: 856 if (icmp6_notify_error(&m, off, icmp6len, code) != 0) { 857 /* In this case, m should've been freed. */ 858 *mp = NULL; 859 return (IPPROTO_DONE); 860 } 861 break; 862 863 badcode: 864 ICMP6STAT_INC(icp6s_badcode); 865 break; 866 867 badlen: 868 ICMP6STAT_INC(icp6s_badlen); 869 break; 870 } 871 872 /* deliver the packet to appropriate sockets */ 873 icmp6_rip6_input(&m, *offp); 874 875 *mp = m; 876 return (IPPROTO_DONE); 877 878 freeit: 879 m_freem(m); 880 *mp = NULL; 881 return (IPPROTO_DONE); 882 } 883 884 static int 885 icmp6_notify_error(struct mbuf **mp, int off, int icmp6len, int code) 886 { 887 struct mbuf *m; 888 struct icmp6_hdr *icmp6; 889 struct ip6_hdr *eip6; 890 u_int32_t notifymtu; 891 struct sockaddr_in6 icmp6src, icmp6dst; 892 893 m = *mp; 894 895 if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) { 896 ICMP6STAT_INC(icp6s_tooshort); 897 goto freeit; 898 } 899 #ifndef PULLDOWN_TEST 900 IP6_EXTHDR_CHECK(m, off, 901 sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr), -1); 902 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 903 #else 904 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, 905 sizeof(*icmp6) + sizeof(struct ip6_hdr)); 906 if (icmp6 == NULL) { 907 ICMP6STAT_INC(icp6s_tooshort); 908 return (-1); 909 } 910 #endif 911 eip6 = (struct ip6_hdr *)(icmp6 + 1); 912 913 /* Detect the upper level protocol */ 914 { 915 void (*ctlfunc)(int, struct sockaddr *, void *); 916 u_int8_t nxt = eip6->ip6_nxt; 917 int eoff = off + sizeof(struct icmp6_hdr) + 918 sizeof(struct ip6_hdr); 919 struct ip6ctlparam ip6cp; 920 struct in6_addr *finaldst = NULL; 921 int icmp6type = icmp6->icmp6_type; 922 struct ip6_frag *fh; 923 struct ip6_rthdr *rth; 924 struct ip6_rthdr0 *rth0; 925 int rthlen; 926 927 while (1) { /* XXX: should avoid infinite loop explicitly? */ 928 struct ip6_ext *eh; 929 930 switch (nxt) { 931 case IPPROTO_HOPOPTS: 932 case IPPROTO_DSTOPTS: 933 case IPPROTO_AH: 934 #ifndef PULLDOWN_TEST 935 IP6_EXTHDR_CHECK(m, 0, 936 eoff + sizeof(struct ip6_ext), -1); 937 eh = (struct ip6_ext *)(mtod(m, caddr_t) + eoff); 938 #else 939 IP6_EXTHDR_GET(eh, struct ip6_ext *, m, 940 eoff, sizeof(*eh)); 941 if (eh == NULL) { 942 ICMP6STAT_INC(icp6s_tooshort); 943 return (-1); 944 } 945 #endif 946 947 if (nxt == IPPROTO_AH) 948 eoff += (eh->ip6e_len + 2) << 2; 949 else 950 eoff += (eh->ip6e_len + 1) << 3; 951 nxt = eh->ip6e_nxt; 952 break; 953 case IPPROTO_ROUTING: 954 /* 955 * When the erroneous packet contains a 956 * routing header, we should examine the 957 * header to determine the final destination. 958 * Otherwise, we can't properly update 959 * information that depends on the final 960 * destination (e.g. path MTU). 961 */ 962 #ifndef PULLDOWN_TEST 963 IP6_EXTHDR_CHECK(m, 0, eoff + sizeof(*rth), -1); 964 rth = (struct ip6_rthdr *) 965 (mtod(m, caddr_t) + eoff); 966 #else 967 IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m, 968 eoff, sizeof(*rth)); 969 if (rth == NULL) { 970 ICMP6STAT_INC(icp6s_tooshort); 971 return (-1); 972 } 973 #endif 974 rthlen = (rth->ip6r_len + 1) << 3; 975 /* 976 * XXX: currently there is no 977 * officially defined type other 978 * than type-0. 979 * Note that if the segment left field 980 * is 0, all intermediate hops must 981 * have been passed. 982 */ 983 if (rth->ip6r_segleft && 984 rth->ip6r_type == IPV6_RTHDR_TYPE_0) { 985 int hops; 986 987 #ifndef PULLDOWN_TEST 988 IP6_EXTHDR_CHECK(m, 0, eoff + rthlen, -1); 989 rth0 = (struct ip6_rthdr0 *) 990 (mtod(m, caddr_t) + eoff); 991 #else 992 IP6_EXTHDR_GET(rth0, 993 struct ip6_rthdr0 *, m, 994 eoff, rthlen); 995 if (rth0 == NULL) { 996 ICMP6STAT_INC(icp6s_tooshort); 997 return (-1); 998 } 999 #endif 1000 /* just ignore a bogus header */ 1001 if ((rth0->ip6r0_len % 2) == 0 && 1002 (hops = rth0->ip6r0_len/2)) 1003 finaldst = (struct in6_addr *)(rth0 + 1) + (hops - 1); 1004 } 1005 eoff += rthlen; 1006 nxt = rth->ip6r_nxt; 1007 break; 1008 case IPPROTO_FRAGMENT: 1009 #ifndef PULLDOWN_TEST 1010 IP6_EXTHDR_CHECK(m, 0, eoff + 1011 sizeof(struct ip6_frag), -1); 1012 fh = (struct ip6_frag *)(mtod(m, caddr_t) + 1013 eoff); 1014 #else 1015 IP6_EXTHDR_GET(fh, struct ip6_frag *, m, 1016 eoff, sizeof(*fh)); 1017 if (fh == NULL) { 1018 ICMP6STAT_INC(icp6s_tooshort); 1019 return (-1); 1020 } 1021 #endif 1022 /* 1023 * Data after a fragment header is meaningless 1024 * unless it is the first fragment, but 1025 * we'll go to the notify label for path MTU 1026 * discovery. 1027 */ 1028 if (fh->ip6f_offlg & IP6F_OFF_MASK) 1029 goto notify; 1030 1031 eoff += sizeof(struct ip6_frag); 1032 nxt = fh->ip6f_nxt; 1033 break; 1034 default: 1035 /* 1036 * This case includes ESP and the No Next 1037 * Header. In such cases going to the notify 1038 * label does not have any meaning 1039 * (i.e. ctlfunc will be NULL), but we go 1040 * anyway since we might have to update 1041 * path MTU information. 1042 */ 1043 goto notify; 1044 } 1045 } 1046 notify: 1047 #ifndef PULLDOWN_TEST 1048 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 1049 #else 1050 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, 1051 sizeof(*icmp6) + sizeof(struct ip6_hdr)); 1052 if (icmp6 == NULL) { 1053 ICMP6STAT_INC(icp6s_tooshort); 1054 return (-1); 1055 } 1056 #endif 1057 1058 /* 1059 * retrieve parameters from the inner IPv6 header, and convert 1060 * them into sockaddr structures. 1061 * XXX: there is no guarantee that the source or destination 1062 * addresses of the inner packet are in the same scope as 1063 * the addresses of the icmp packet. But there is no other 1064 * way to determine the zone. 1065 */ 1066 eip6 = (struct ip6_hdr *)(icmp6 + 1); 1067 1068 bzero(&icmp6dst, sizeof(icmp6dst)); 1069 icmp6dst.sin6_len = sizeof(struct sockaddr_in6); 1070 icmp6dst.sin6_family = AF_INET6; 1071 if (finaldst == NULL) 1072 icmp6dst.sin6_addr = eip6->ip6_dst; 1073 else 1074 icmp6dst.sin6_addr = *finaldst; 1075 if (in6_setscope(&icmp6dst.sin6_addr, m->m_pkthdr.rcvif, NULL)) 1076 goto freeit; 1077 bzero(&icmp6src, sizeof(icmp6src)); 1078 icmp6src.sin6_len = sizeof(struct sockaddr_in6); 1079 icmp6src.sin6_family = AF_INET6; 1080 icmp6src.sin6_addr = eip6->ip6_src; 1081 if (in6_setscope(&icmp6src.sin6_addr, m->m_pkthdr.rcvif, NULL)) 1082 goto freeit; 1083 icmp6src.sin6_flowinfo = 1084 (eip6->ip6_flow & IPV6_FLOWLABEL_MASK); 1085 1086 if (finaldst == NULL) 1087 finaldst = &eip6->ip6_dst; 1088 ip6cp.ip6c_m = m; 1089 ip6cp.ip6c_icmp6 = icmp6; 1090 ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1); 1091 ip6cp.ip6c_off = eoff; 1092 ip6cp.ip6c_finaldst = finaldst; 1093 ip6cp.ip6c_src = &icmp6src; 1094 ip6cp.ip6c_nxt = nxt; 1095 1096 if (icmp6type == ICMP6_PACKET_TOO_BIG) { 1097 notifymtu = ntohl(icmp6->icmp6_mtu); 1098 ip6cp.ip6c_cmdarg = (void *)¬ifymtu; 1099 icmp6_mtudisc_update(&ip6cp, 1); /*XXX*/ 1100 } 1101 1102 ctlfunc = (void (*)(int, struct sockaddr *, void *)) 1103 (inet6sw[ip6_protox[nxt]].pr_ctlinput); 1104 if (ctlfunc) { 1105 (void) (*ctlfunc)(code, (struct sockaddr *)&icmp6dst, 1106 &ip6cp); 1107 } 1108 } 1109 *mp = m; 1110 return (0); 1111 1112 freeit: 1113 m_freem(m); 1114 *mp = NULL; 1115 return (-1); 1116 } 1117 1118 void 1119 icmp6_mtudisc_update(struct ip6ctlparam *ip6cp, int validated) 1120 { 1121 struct in6_addr *dst = ip6cp->ip6c_finaldst; 1122 struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6; 1123 struct mbuf *m = ip6cp->ip6c_m; /* will be necessary for scope issue */ 1124 u_int mtu = ntohl(icmp6->icmp6_mtu); 1125 struct in_conninfo inc; 1126 1127 #if 0 1128 /* 1129 * RFC2460 section 5, last paragraph. 1130 * even though minimum link MTU for IPv6 is IPV6_MMTU, 1131 * we may see ICMPv6 too big with mtu < IPV6_MMTU 1132 * due to packet translator in the middle. 1133 * see ip6_output() and ip6_getpmtu() "alwaysfrag" case for 1134 * special handling. 1135 */ 1136 if (mtu < IPV6_MMTU) 1137 return; 1138 #endif 1139 1140 /* 1141 * we reject ICMPv6 too big with abnormally small value. 1142 * XXX what is the good definition of "abnormally small"? 1143 */ 1144 if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8) 1145 return; 1146 1147 if (!validated) 1148 return; 1149 1150 /* 1151 * In case the suggested mtu is less than IPV6_MMTU, we 1152 * only need to remember that it was for above mentioned 1153 * "alwaysfrag" case. 1154 * Try to be as close to the spec as possible. 1155 */ 1156 if (mtu < IPV6_MMTU) 1157 mtu = IPV6_MMTU - 8; 1158 1159 bzero(&inc, sizeof(inc)); 1160 inc.inc_fibnum = M_GETFIB(m); 1161 inc.inc_flags |= INC_ISIPV6; 1162 inc.inc6_faddr = *dst; 1163 if (in6_setscope(&inc.inc6_faddr, m->m_pkthdr.rcvif, NULL)) 1164 return; 1165 1166 if (mtu < tcp_maxmtu6(&inc, NULL)) { 1167 tcp_hc_updatemtu(&inc, mtu); 1168 ICMP6STAT_INC(icp6s_pmtuchg); 1169 } 1170 } 1171 1172 /* 1173 * Process a Node Information Query packet, based on 1174 * draft-ietf-ipngwg-icmp-name-lookups-07. 1175 * 1176 * Spec incompatibilities: 1177 * - IPv6 Subject address handling 1178 * - IPv4 Subject address handling support missing 1179 * - Proxy reply (answer even if it's not for me) 1180 * - joins NI group address at in6_ifattach() time only, does not cope 1181 * with hostname changes by sethostname(3) 1182 */ 1183 static struct mbuf * 1184 ni6_input(struct mbuf *m, int off, struct prison *pr) 1185 { 1186 struct icmp6_nodeinfo *ni6, *nni6; 1187 struct mbuf *n = NULL; 1188 u_int16_t qtype; 1189 int subjlen; 1190 int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); 1191 struct ni_reply_fqdn *fqdn; 1192 int addrs; /* for NI_QTYPE_NODEADDR */ 1193 struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */ 1194 struct in6_addr in6_subj; /* subject address */ 1195 struct ip6_hdr *ip6; 1196 int oldfqdn = 0; /* if 1, return pascal string (03 draft) */ 1197 char *subj = NULL; 1198 struct in6_ifaddr *ia6 = NULL; 1199 1200 ip6 = mtod(m, struct ip6_hdr *); 1201 #ifndef PULLDOWN_TEST 1202 ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off); 1203 #else 1204 IP6_EXTHDR_GET(ni6, struct icmp6_nodeinfo *, m, off, sizeof(*ni6)); 1205 if (ni6 == NULL) { 1206 /* m is already reclaimed */ 1207 return (NULL); 1208 } 1209 #endif 1210 1211 /* 1212 * Validate IPv6 source address. 1213 * The default configuration MUST be to refuse answering queries from 1214 * global-scope addresses according to RFC4602. 1215 * Notes: 1216 * - it's not very clear what "refuse" means; this implementation 1217 * simply drops it. 1218 * - it's not very easy to identify global-scope (unicast) addresses 1219 * since there are many prefixes for them. It should be safer 1220 * and in practice sufficient to check "all" but loopback and 1221 * link-local (note that site-local unicast was deprecated and 1222 * ULA is defined as global scope-wise) 1223 */ 1224 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_GLOBALOK) == 0 && 1225 !IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) && 1226 !IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) 1227 goto bad; 1228 1229 /* 1230 * Validate IPv6 destination address. 1231 * 1232 * The Responder must discard the Query without further processing 1233 * unless it is one of the Responder's unicast or anycast addresses, or 1234 * a link-local scope multicast address which the Responder has joined. 1235 * [RFC4602, Section 5.] 1236 */ 1237 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 1238 if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst)) 1239 goto bad; 1240 /* else it's a link-local multicast, fine */ 1241 } else { /* unicast or anycast */ 1242 ia6 = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */); 1243 if (ia6 == NULL) 1244 goto bad; /* XXX impossible */ 1245 1246 if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) && 1247 !(V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK)) { 1248 ifa_free(&ia6->ia_ifa); 1249 nd6log((LOG_DEBUG, "ni6_input: ignore node info to " 1250 "a temporary address in %s:%d", 1251 __FILE__, __LINE__)); 1252 goto bad; 1253 } 1254 ifa_free(&ia6->ia_ifa); 1255 } 1256 1257 /* validate query Subject field. */ 1258 qtype = ntohs(ni6->ni_qtype); 1259 subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo); 1260 switch (qtype) { 1261 case NI_QTYPE_NOOP: 1262 case NI_QTYPE_SUPTYPES: 1263 /* 07 draft */ 1264 if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0) 1265 break; 1266 /* FALLTHROUGH */ 1267 case NI_QTYPE_FQDN: 1268 case NI_QTYPE_NODEADDR: 1269 case NI_QTYPE_IPV4ADDR: 1270 switch (ni6->ni_code) { 1271 case ICMP6_NI_SUBJ_IPV6: 1272 #if ICMP6_NI_SUBJ_IPV6 != 0 1273 case 0: 1274 #endif 1275 /* 1276 * backward compatibility - try to accept 03 draft 1277 * format, where no Subject is present. 1278 */ 1279 if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 && 1280 subjlen == 0) { 1281 oldfqdn++; 1282 break; 1283 } 1284 #if ICMP6_NI_SUBJ_IPV6 != 0 1285 if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6) 1286 goto bad; 1287 #endif 1288 1289 if (subjlen != sizeof(struct in6_addr)) 1290 goto bad; 1291 1292 /* 1293 * Validate Subject address. 1294 * 1295 * Not sure what exactly "address belongs to the node" 1296 * means in the spec, is it just unicast, or what? 1297 * 1298 * At this moment we consider Subject address as 1299 * "belong to the node" if the Subject address equals 1300 * to the IPv6 destination address; validation for 1301 * IPv6 destination address should have done enough 1302 * check for us. 1303 * 1304 * We do not do proxy at this moment. 1305 */ 1306 /* m_pulldown instead of copy? */ 1307 m_copydata(m, off + sizeof(struct icmp6_nodeinfo), 1308 subjlen, (caddr_t)&in6_subj); 1309 if (in6_setscope(&in6_subj, m->m_pkthdr.rcvif, NULL)) 1310 goto bad; 1311 1312 subj = (char *)&in6_subj; 1313 if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &in6_subj)) 1314 break; 1315 1316 /* 1317 * XXX if we are to allow other cases, we should really 1318 * be careful about scope here. 1319 * basically, we should disallow queries toward IPv6 1320 * destination X with subject Y, 1321 * if scope(X) > scope(Y). 1322 * if we allow scope(X) > scope(Y), it will result in 1323 * information leakage across scope boundary. 1324 */ 1325 goto bad; 1326 1327 case ICMP6_NI_SUBJ_FQDN: 1328 /* 1329 * Validate Subject name with gethostname(3). 1330 * 1331 * The behavior may need some debate, since: 1332 * - we are not sure if the node has FQDN as 1333 * hostname (returned by gethostname(3)). 1334 * - the code does wildcard match for truncated names. 1335 * however, we are not sure if we want to perform 1336 * wildcard match, if gethostname(3) side has 1337 * truncated hostname. 1338 */ 1339 mtx_lock(&pr->pr_mtx); 1340 n = ni6_nametodns(pr->pr_hostname, 1341 strlen(pr->pr_hostname), 0); 1342 mtx_unlock(&pr->pr_mtx); 1343 if (!n || n->m_next || n->m_len == 0) 1344 goto bad; 1345 IP6_EXTHDR_GET(subj, char *, m, 1346 off + sizeof(struct icmp6_nodeinfo), subjlen); 1347 if (subj == NULL) 1348 goto bad; 1349 if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *), 1350 n->m_len)) { 1351 goto bad; 1352 } 1353 m_freem(n); 1354 n = NULL; 1355 break; 1356 1357 case ICMP6_NI_SUBJ_IPV4: /* XXX: to be implemented? */ 1358 default: 1359 goto bad; 1360 } 1361 break; 1362 } 1363 1364 /* refuse based on configuration. XXX ICMP6_NI_REFUSED? */ 1365 switch (qtype) { 1366 case NI_QTYPE_FQDN: 1367 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_FQDNOK) == 0) 1368 goto bad; 1369 break; 1370 case NI_QTYPE_NODEADDR: 1371 case NI_QTYPE_IPV4ADDR: 1372 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_NODEADDROK) == 0) 1373 goto bad; 1374 break; 1375 } 1376 1377 /* guess reply length */ 1378 switch (qtype) { 1379 case NI_QTYPE_NOOP: 1380 break; /* no reply data */ 1381 case NI_QTYPE_SUPTYPES: 1382 replylen += sizeof(u_int32_t); 1383 break; 1384 case NI_QTYPE_FQDN: 1385 /* XXX will append an mbuf */ 1386 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); 1387 break; 1388 case NI_QTYPE_NODEADDR: 1389 addrs = ni6_addrs(ni6, m, &ifp, (struct in6_addr *)subj); 1390 if ((replylen += addrs * (sizeof(struct in6_addr) + 1391 sizeof(u_int32_t))) > MCLBYTES) 1392 replylen = MCLBYTES; /* XXX: will truncate pkt later */ 1393 break; 1394 case NI_QTYPE_IPV4ADDR: 1395 /* unsupported - should respond with unknown Qtype? */ 1396 break; 1397 default: 1398 /* 1399 * XXX: We must return a reply with the ICMP6 code 1400 * `unknown Qtype' in this case. However we regard the case 1401 * as an FQDN query for backward compatibility. 1402 * Older versions set a random value to this field, 1403 * so it rarely varies in the defined qtypes. 1404 * But the mechanism is not reliable... 1405 * maybe we should obsolete older versions. 1406 */ 1407 qtype = NI_QTYPE_FQDN; 1408 /* XXX will append an mbuf */ 1409 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); 1410 oldfqdn++; 1411 break; 1412 } 1413 1414 /* Allocate an mbuf to reply. */ 1415 if (replylen > MCLBYTES) { 1416 /* 1417 * XXX: should we try to allocate more? But MCLBYTES 1418 * is probably much larger than IPV6_MMTU... 1419 */ 1420 goto bad; 1421 } 1422 if (replylen > MHLEN) 1423 n = m_getcl(M_NOWAIT, m->m_type, M_PKTHDR); 1424 else 1425 n = m_gethdr(M_NOWAIT, m->m_type); 1426 if (n == NULL) { 1427 m_freem(m); 1428 return (NULL); 1429 } 1430 m_move_pkthdr(n, m); /* just for recvif and FIB */ 1431 n->m_pkthdr.len = n->m_len = replylen; 1432 1433 /* copy mbuf header and IPv6 + Node Information base headers */ 1434 bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr)); 1435 nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1); 1436 bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo)); 1437 1438 /* qtype dependent procedure */ 1439 switch (qtype) { 1440 case NI_QTYPE_NOOP: 1441 nni6->ni_code = ICMP6_NI_SUCCESS; 1442 nni6->ni_flags = 0; 1443 break; 1444 case NI_QTYPE_SUPTYPES: 1445 { 1446 u_int32_t v; 1447 nni6->ni_code = ICMP6_NI_SUCCESS; 1448 nni6->ni_flags = htons(0x0000); /* raw bitmap */ 1449 /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */ 1450 v = (u_int32_t)htonl(0x0000000f); 1451 bcopy(&v, nni6 + 1, sizeof(u_int32_t)); 1452 break; 1453 } 1454 case NI_QTYPE_FQDN: 1455 nni6->ni_code = ICMP6_NI_SUCCESS; 1456 fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) + 1457 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo)); 1458 nni6->ni_flags = 0; /* XXX: meaningless TTL */ 1459 fqdn->ni_fqdn_ttl = 0; /* ditto. */ 1460 /* 1461 * XXX do we really have FQDN in hostname? 1462 */ 1463 mtx_lock(&pr->pr_mtx); 1464 n->m_next = ni6_nametodns(pr->pr_hostname, 1465 strlen(pr->pr_hostname), oldfqdn); 1466 mtx_unlock(&pr->pr_mtx); 1467 if (n->m_next == NULL) 1468 goto bad; 1469 /* XXX we assume that n->m_next is not a chain */ 1470 if (n->m_next->m_next != NULL) 1471 goto bad; 1472 n->m_pkthdr.len += n->m_next->m_len; 1473 break; 1474 case NI_QTYPE_NODEADDR: 1475 { 1476 int lenlim, copied; 1477 1478 nni6->ni_code = ICMP6_NI_SUCCESS; 1479 n->m_pkthdr.len = n->m_len = 1480 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); 1481 lenlim = M_TRAILINGSPACE(n); 1482 copied = ni6_store_addrs(ni6, nni6, ifp, lenlim); 1483 /* XXX: reset mbuf length */ 1484 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + 1485 sizeof(struct icmp6_nodeinfo) + copied; 1486 break; 1487 } 1488 default: 1489 break; /* XXX impossible! */ 1490 } 1491 1492 nni6->ni_type = ICMP6_NI_REPLY; 1493 m_freem(m); 1494 return (n); 1495 1496 bad: 1497 m_freem(m); 1498 if (n) 1499 m_freem(n); 1500 return (NULL); 1501 } 1502 1503 /* 1504 * make a mbuf with DNS-encoded string. no compression support. 1505 * 1506 * XXX names with less than 2 dots (like "foo" or "foo.section") will be 1507 * treated as truncated name (two \0 at the end). this is a wild guess. 1508 * 1509 * old - return pascal string if non-zero 1510 */ 1511 static struct mbuf * 1512 ni6_nametodns(const char *name, int namelen, int old) 1513 { 1514 struct mbuf *m; 1515 char *cp, *ep; 1516 const char *p, *q; 1517 int i, len, nterm; 1518 1519 if (old) 1520 len = namelen + 1; 1521 else 1522 len = MCLBYTES; 1523 1524 /* Because MAXHOSTNAMELEN is usually 256, we use cluster mbuf. */ 1525 if (len > MLEN) 1526 m = m_getcl(M_NOWAIT, MT_DATA, 0); 1527 else 1528 m = m_get(M_NOWAIT, MT_DATA); 1529 if (m == NULL) 1530 goto fail; 1531 1532 if (old) { 1533 m->m_len = len; 1534 *mtod(m, char *) = namelen; 1535 bcopy(name, mtod(m, char *) + 1, namelen); 1536 return m; 1537 } else { 1538 m->m_len = 0; 1539 cp = mtod(m, char *); 1540 ep = mtod(m, char *) + M_TRAILINGSPACE(m); 1541 1542 /* if not certain about my name, return empty buffer */ 1543 if (namelen == 0) 1544 return m; 1545 1546 /* 1547 * guess if it looks like shortened hostname, or FQDN. 1548 * shortened hostname needs two trailing "\0". 1549 */ 1550 i = 0; 1551 for (p = name; p < name + namelen; p++) { 1552 if (*p && *p == '.') 1553 i++; 1554 } 1555 if (i < 2) 1556 nterm = 2; 1557 else 1558 nterm = 1; 1559 1560 p = name; 1561 while (cp < ep && p < name + namelen) { 1562 i = 0; 1563 for (q = p; q < name + namelen && *q && *q != '.'; q++) 1564 i++; 1565 /* result does not fit into mbuf */ 1566 if (cp + i + 1 >= ep) 1567 goto fail; 1568 /* 1569 * DNS label length restriction, RFC1035 page 8. 1570 * "i == 0" case is included here to avoid returning 1571 * 0-length label on "foo..bar". 1572 */ 1573 if (i <= 0 || i >= 64) 1574 goto fail; 1575 *cp++ = i; 1576 bcopy(p, cp, i); 1577 cp += i; 1578 p = q; 1579 if (p < name + namelen && *p == '.') 1580 p++; 1581 } 1582 /* termination */ 1583 if (cp + nterm >= ep) 1584 goto fail; 1585 while (nterm-- > 0) 1586 *cp++ = '\0'; 1587 m->m_len = cp - mtod(m, char *); 1588 return m; 1589 } 1590 1591 panic("should not reach here"); 1592 /* NOTREACHED */ 1593 1594 fail: 1595 if (m) 1596 m_freem(m); 1597 return NULL; 1598 } 1599 1600 /* 1601 * check if two DNS-encoded string matches. takes care of truncated 1602 * form (with \0\0 at the end). no compression support. 1603 * XXX upper/lowercase match (see RFC2065) 1604 */ 1605 static int 1606 ni6_dnsmatch(const char *a, int alen, const char *b, int blen) 1607 { 1608 const char *a0, *b0; 1609 int l; 1610 1611 /* simplest case - need validation? */ 1612 if (alen == blen && bcmp(a, b, alen) == 0) 1613 return 1; 1614 1615 a0 = a; 1616 b0 = b; 1617 1618 /* termination is mandatory */ 1619 if (alen < 2 || blen < 2) 1620 return 0; 1621 if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0') 1622 return 0; 1623 alen--; 1624 blen--; 1625 1626 while (a - a0 < alen && b - b0 < blen) { 1627 if (a - a0 + 1 > alen || b - b0 + 1 > blen) 1628 return 0; 1629 1630 if ((signed char)a[0] < 0 || (signed char)b[0] < 0) 1631 return 0; 1632 /* we don't support compression yet */ 1633 if (a[0] >= 64 || b[0] >= 64) 1634 return 0; 1635 1636 /* truncated case */ 1637 if (a[0] == 0 && a - a0 == alen - 1) 1638 return 1; 1639 if (b[0] == 0 && b - b0 == blen - 1) 1640 return 1; 1641 if (a[0] == 0 || b[0] == 0) 1642 return 0; 1643 1644 if (a[0] != b[0]) 1645 return 0; 1646 l = a[0]; 1647 if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen) 1648 return 0; 1649 if (bcmp(a + 1, b + 1, l) != 0) 1650 return 0; 1651 1652 a += 1 + l; 1653 b += 1 + l; 1654 } 1655 1656 if (a - a0 == alen && b - b0 == blen) 1657 return 1; 1658 else 1659 return 0; 1660 } 1661 1662 /* 1663 * calculate the number of addresses to be returned in the node info reply. 1664 */ 1665 static int 1666 ni6_addrs(struct icmp6_nodeinfo *ni6, struct mbuf *m, struct ifnet **ifpp, 1667 struct in6_addr *subj) 1668 { 1669 struct ifnet *ifp; 1670 struct in6_ifaddr *ifa6; 1671 struct ifaddr *ifa; 1672 int addrs = 0, addrsofif, iffound = 0; 1673 int niflags = ni6->ni_flags; 1674 1675 NET_EPOCH_ASSERT(); 1676 1677 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) { 1678 switch (ni6->ni_code) { 1679 case ICMP6_NI_SUBJ_IPV6: 1680 if (subj == NULL) /* must be impossible... */ 1681 return (0); 1682 break; 1683 default: 1684 /* 1685 * XXX: we only support IPv6 subject address for 1686 * this Qtype. 1687 */ 1688 return (0); 1689 } 1690 } 1691 1692 CK_STAILQ_FOREACH(ifp, &V_ifnet, if_link) { 1693 addrsofif = 0; 1694 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 1695 if (ifa->ifa_addr->sa_family != AF_INET6) 1696 continue; 1697 ifa6 = (struct in6_ifaddr *)ifa; 1698 1699 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 && 1700 IN6_ARE_ADDR_EQUAL(subj, &ifa6->ia_addr.sin6_addr)) 1701 iffound = 1; 1702 1703 /* 1704 * IPv4-mapped addresses can only be returned by a 1705 * Node Information proxy, since they represent 1706 * addresses of IPv4-only nodes, which perforce do 1707 * not implement this protocol. 1708 * [icmp-name-lookups-07, Section 5.4] 1709 * So we don't support NI_NODEADDR_FLAG_COMPAT in 1710 * this function at this moment. 1711 */ 1712 1713 /* What do we have to do about ::1? */ 1714 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { 1715 case IPV6_ADDR_SCOPE_LINKLOCAL: 1716 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) 1717 continue; 1718 break; 1719 case IPV6_ADDR_SCOPE_SITELOCAL: 1720 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) 1721 continue; 1722 break; 1723 case IPV6_ADDR_SCOPE_GLOBAL: 1724 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) 1725 continue; 1726 break; 1727 default: 1728 continue; 1729 } 1730 1731 /* 1732 * check if anycast is okay. 1733 * XXX: just experimental. not in the spec. 1734 */ 1735 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && 1736 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) 1737 continue; /* we need only unicast addresses */ 1738 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && 1739 (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) { 1740 continue; 1741 } 1742 addrsofif++; /* count the address */ 1743 } 1744 if (iffound) { 1745 *ifpp = ifp; 1746 return (addrsofif); 1747 } 1748 1749 addrs += addrsofif; 1750 } 1751 1752 return (addrs); 1753 } 1754 1755 static int 1756 ni6_store_addrs(struct icmp6_nodeinfo *ni6, struct icmp6_nodeinfo *nni6, 1757 struct ifnet *ifp0, int resid) 1758 { 1759 struct ifnet *ifp; 1760 struct in6_ifaddr *ifa6; 1761 struct ifaddr *ifa; 1762 struct ifnet *ifp_dep = NULL; 1763 int copied = 0, allow_deprecated = 0; 1764 u_char *cp = (u_char *)(nni6 + 1); 1765 int niflags = ni6->ni_flags; 1766 u_int32_t ltime; 1767 1768 NET_EPOCH_ASSERT(); 1769 1770 if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL)) 1771 return (0); /* needless to copy */ 1772 1773 ifp = ifp0 ? ifp0 : CK_STAILQ_FIRST(&V_ifnet); 1774 again: 1775 1776 for (; ifp; ifp = CK_STAILQ_NEXT(ifp, if_link)) { 1777 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 1778 if (ifa->ifa_addr->sa_family != AF_INET6) 1779 continue; 1780 ifa6 = (struct in6_ifaddr *)ifa; 1781 1782 if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 && 1783 allow_deprecated == 0) { 1784 /* 1785 * prefererred address should be put before 1786 * deprecated addresses. 1787 */ 1788 1789 /* record the interface for later search */ 1790 if (ifp_dep == NULL) 1791 ifp_dep = ifp; 1792 1793 continue; 1794 } else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 && 1795 allow_deprecated != 0) 1796 continue; /* we now collect deprecated addrs */ 1797 1798 /* What do we have to do about ::1? */ 1799 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { 1800 case IPV6_ADDR_SCOPE_LINKLOCAL: 1801 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) 1802 continue; 1803 break; 1804 case IPV6_ADDR_SCOPE_SITELOCAL: 1805 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) 1806 continue; 1807 break; 1808 case IPV6_ADDR_SCOPE_GLOBAL: 1809 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) 1810 continue; 1811 break; 1812 default: 1813 continue; 1814 } 1815 1816 /* 1817 * check if anycast is okay. 1818 * XXX: just experimental. not in the spec. 1819 */ 1820 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && 1821 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) 1822 continue; 1823 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && 1824 (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) { 1825 continue; 1826 } 1827 1828 /* now we can copy the address */ 1829 if (resid < sizeof(struct in6_addr) + 1830 sizeof(u_int32_t)) { 1831 /* 1832 * We give up much more copy. 1833 * Set the truncate flag and return. 1834 */ 1835 nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE; 1836 return (copied); 1837 } 1838 1839 /* 1840 * Set the TTL of the address. 1841 * The TTL value should be one of the following 1842 * according to the specification: 1843 * 1844 * 1. The remaining lifetime of a DHCP lease on the 1845 * address, or 1846 * 2. The remaining Valid Lifetime of a prefix from 1847 * which the address was derived through Stateless 1848 * Autoconfiguration. 1849 * 1850 * Note that we currently do not support stateful 1851 * address configuration by DHCPv6, so the former 1852 * case can't happen. 1853 */ 1854 if (ifa6->ia6_lifetime.ia6t_expire == 0) 1855 ltime = ND6_INFINITE_LIFETIME; 1856 else { 1857 if (ifa6->ia6_lifetime.ia6t_expire > 1858 time_uptime) 1859 ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_uptime); 1860 else 1861 ltime = 0; 1862 } 1863 1864 bcopy(<ime, cp, sizeof(u_int32_t)); 1865 cp += sizeof(u_int32_t); 1866 1867 /* copy the address itself */ 1868 bcopy(&ifa6->ia_addr.sin6_addr, cp, 1869 sizeof(struct in6_addr)); 1870 in6_clearscope((struct in6_addr *)cp); /* XXX */ 1871 cp += sizeof(struct in6_addr); 1872 1873 resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t)); 1874 copied += (sizeof(struct in6_addr) + sizeof(u_int32_t)); 1875 } 1876 if (ifp0) /* we need search only on the specified IF */ 1877 break; 1878 } 1879 1880 if (allow_deprecated == 0 && ifp_dep != NULL) { 1881 ifp = ifp_dep; 1882 allow_deprecated = 1; 1883 1884 goto again; 1885 } 1886 1887 return (copied); 1888 } 1889 1890 /* 1891 * XXX almost dup'ed code with rip6_input. 1892 */ 1893 static int 1894 icmp6_rip6_input(struct mbuf **mp, int off) 1895 { 1896 struct mbuf *m = *mp; 1897 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1898 struct inpcb *inp; 1899 struct inpcb *last = NULL; 1900 struct sockaddr_in6 fromsa; 1901 struct icmp6_hdr *icmp6; 1902 struct mbuf *opts = NULL; 1903 1904 NET_EPOCH_ASSERT(); 1905 1906 #ifndef PULLDOWN_TEST 1907 /* this is assumed to be safe. */ 1908 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off); 1909 #else 1910 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6)); 1911 if (icmp6 == NULL) { 1912 /* m is already reclaimed */ 1913 return (IPPROTO_DONE); 1914 } 1915 #endif 1916 1917 /* 1918 * XXX: the address may have embedded scope zone ID, which should be 1919 * hidden from applications. 1920 */ 1921 bzero(&fromsa, sizeof(fromsa)); 1922 fromsa.sin6_family = AF_INET6; 1923 fromsa.sin6_len = sizeof(struct sockaddr_in6); 1924 fromsa.sin6_addr = ip6->ip6_src; 1925 if (sa6_recoverscope(&fromsa)) { 1926 m_freem(m); 1927 *mp = NULL; 1928 return (IPPROTO_DONE); 1929 } 1930 1931 CK_LIST_FOREACH(inp, &V_ripcb, inp_list) { 1932 if ((inp->inp_vflag & INP_IPV6) == 0) 1933 continue; 1934 if (inp->inp_ip_p != IPPROTO_ICMPV6) 1935 continue; 1936 if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr) && 1937 !IN6_ARE_ADDR_EQUAL(&inp->in6p_laddr, &ip6->ip6_dst)) 1938 continue; 1939 if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr) && 1940 !IN6_ARE_ADDR_EQUAL(&inp->in6p_faddr, &ip6->ip6_src)) 1941 continue; 1942 INP_RLOCK(inp); 1943 if (__predict_false(inp->inp_flags2 & INP_FREED)) { 1944 INP_RUNLOCK(inp); 1945 continue; 1946 } 1947 if (ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type, 1948 inp->in6p_icmp6filt)) { 1949 INP_RUNLOCK(inp); 1950 continue; 1951 } 1952 if (last != NULL) { 1953 struct mbuf *n = NULL; 1954 1955 /* 1956 * Recent network drivers tend to allocate a single 1957 * mbuf cluster, rather than to make a couple of 1958 * mbufs without clusters. Also, since the IPv6 code 1959 * path tries to avoid m_pullup(), it is highly 1960 * probable that we still have an mbuf cluster here 1961 * even though the necessary length can be stored in an 1962 * mbuf's internal buffer. 1963 * Meanwhile, the default size of the receive socket 1964 * buffer for raw sockets is not so large. This means 1965 * the possibility of packet loss is relatively higher 1966 * than before. To avoid this scenario, we copy the 1967 * received data to a separate mbuf that does not use 1968 * a cluster, if possible. 1969 * XXX: it is better to copy the data after stripping 1970 * intermediate headers. 1971 */ 1972 if ((m->m_flags & M_EXT) && m->m_next == NULL && 1973 m->m_len <= MHLEN) { 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, 1978 m->m_len); 1979 n->m_len = m->m_len; 1980 } else { 1981 m_free(n); 1982 n = NULL; 1983 } 1984 } 1985 } 1986 if (n != NULL || 1987 (n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) != NULL) { 1988 if (last->inp_flags & INP_CONTROLOPTS) 1989 ip6_savecontrol(last, n, &opts); 1990 /* strip intermediate headers */ 1991 m_adj(n, off); 1992 SOCKBUF_LOCK(&last->inp_socket->so_rcv); 1993 if (sbappendaddr_locked( 1994 &last->inp_socket->so_rcv, 1995 (struct sockaddr *)&fromsa, n, opts) 1996 == 0) { 1997 /* should notify about lost packet */ 1998 m_freem(n); 1999 if (opts) { 2000 m_freem(opts); 2001 } 2002 SOCKBUF_UNLOCK( 2003 &last->inp_socket->so_rcv); 2004 } else 2005 sorwakeup_locked(last->inp_socket); 2006 opts = NULL; 2007 } 2008 INP_RUNLOCK(last); 2009 } 2010 last = inp; 2011 } 2012 if (last != NULL) { 2013 if (last->inp_flags & INP_CONTROLOPTS) 2014 ip6_savecontrol(last, m, &opts); 2015 /* strip intermediate headers */ 2016 m_adj(m, off); 2017 2018 /* avoid using mbuf clusters if possible (see above) */ 2019 if ((m->m_flags & M_EXT) && m->m_next == NULL && 2020 m->m_len <= MHLEN) { 2021 struct mbuf *n; 2022 2023 n = m_get(M_NOWAIT, m->m_type); 2024 if (n != NULL) { 2025 if (m_dup_pkthdr(n, m, M_NOWAIT)) { 2026 bcopy(m->m_data, n->m_data, m->m_len); 2027 n->m_len = m->m_len; 2028 2029 m_freem(m); 2030 m = n; 2031 } else { 2032 m_freem(n); 2033 n = NULL; 2034 } 2035 } 2036 } 2037 SOCKBUF_LOCK(&last->inp_socket->so_rcv); 2038 if (sbappendaddr_locked(&last->inp_socket->so_rcv, 2039 (struct sockaddr *)&fromsa, m, opts) == 0) { 2040 m_freem(m); 2041 if (opts) 2042 m_freem(opts); 2043 SOCKBUF_UNLOCK(&last->inp_socket->so_rcv); 2044 } else 2045 sorwakeup_locked(last->inp_socket); 2046 INP_RUNLOCK(last); 2047 } else { 2048 m_freem(m); 2049 IP6STAT_DEC(ip6s_delivered); 2050 } 2051 *mp = NULL; 2052 return (IPPROTO_DONE); 2053 } 2054 2055 /* 2056 * Reflect the ip6 packet back to the source. 2057 * OFF points to the icmp6 header, counted from the top of the mbuf. 2058 */ 2059 void 2060 icmp6_reflect(struct mbuf *m, size_t off) 2061 { 2062 struct in6_addr src6, *srcp; 2063 struct ip6_hdr *ip6; 2064 struct icmp6_hdr *icmp6; 2065 struct in6_ifaddr *ia = NULL; 2066 struct ifnet *outif = NULL; 2067 int plen; 2068 int type, code, hlim; 2069 2070 /* too short to reflect */ 2071 if (off < sizeof(struct ip6_hdr)) { 2072 nd6log((LOG_DEBUG, 2073 "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n", 2074 (u_long)off, (u_long)sizeof(struct ip6_hdr), 2075 __FILE__, __LINE__)); 2076 goto bad; 2077 } 2078 2079 /* 2080 * If there are extra headers between IPv6 and ICMPv6, strip 2081 * off that header first. 2082 */ 2083 #ifdef DIAGNOSTIC 2084 if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN) 2085 panic("assumption failed in icmp6_reflect"); 2086 #endif 2087 if (off > sizeof(struct ip6_hdr)) { 2088 size_t l; 2089 struct ip6_hdr nip6; 2090 2091 l = off - sizeof(struct ip6_hdr); 2092 m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6); 2093 m_adj(m, l); 2094 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 2095 if (m->m_len < l) { 2096 if ((m = m_pullup(m, l)) == NULL) 2097 return; 2098 } 2099 bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6)); 2100 } else /* off == sizeof(struct ip6_hdr) */ { 2101 size_t l; 2102 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 2103 if (m->m_len < l) { 2104 if ((m = m_pullup(m, l)) == NULL) 2105 return; 2106 } 2107 } 2108 plen = m->m_pkthdr.len - sizeof(struct ip6_hdr); 2109 ip6 = mtod(m, struct ip6_hdr *); 2110 ip6->ip6_nxt = IPPROTO_ICMPV6; 2111 icmp6 = (struct icmp6_hdr *)(ip6 + 1); 2112 type = icmp6->icmp6_type; /* keep type for statistics */ 2113 code = icmp6->icmp6_code; /* ditto. */ 2114 hlim = 0; 2115 srcp = NULL; 2116 2117 /* 2118 * If the incoming packet was addressed directly to us (i.e. unicast), 2119 * use dst as the src for the reply. 2120 * The IN6_IFF_NOTREADY case should be VERY rare, but is possible 2121 * (for example) when we encounter an error while forwarding procedure 2122 * destined to a duplicated address of ours. 2123 */ 2124 if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 2125 ia = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */); 2126 if (ia != NULL && !(ia->ia6_flags & 2127 (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) { 2128 src6 = ia->ia_addr.sin6_addr; 2129 srcp = &src6; 2130 2131 if (m->m_pkthdr.rcvif != NULL) { 2132 /* XXX: This may not be the outgoing interface */ 2133 hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim; 2134 } else 2135 hlim = V_ip6_defhlim; 2136 } 2137 if (ia != NULL) 2138 ifa_free(&ia->ia_ifa); 2139 } 2140 2141 if (srcp == NULL) { 2142 int error; 2143 struct in6_addr dst6; 2144 uint32_t scopeid; 2145 2146 /* 2147 * This case matches to multicasts, our anycast, or unicasts 2148 * that we do not own. Select a source address based on the 2149 * source address of the erroneous packet. 2150 */ 2151 in6_splitscope(&ip6->ip6_src, &dst6, &scopeid); 2152 error = in6_selectsrc_addr(M_GETFIB(m), &dst6, 2153 scopeid, NULL, &src6, &hlim); 2154 2155 if (error) { 2156 char ip6buf[INET6_ADDRSTRLEN]; 2157 nd6log((LOG_DEBUG, 2158 "icmp6_reflect: source can't be determined: " 2159 "dst=%s, error=%d\n", 2160 ip6_sprintf(ip6buf, &ip6->ip6_dst), error)); 2161 goto bad; 2162 } 2163 srcp = &src6; 2164 } 2165 /* 2166 * ip6_input() drops a packet if its src is multicast. 2167 * So, the src is never multicast. 2168 */ 2169 ip6->ip6_dst = ip6->ip6_src; 2170 ip6->ip6_src = *srcp; 2171 ip6->ip6_flow = 0; 2172 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2173 ip6->ip6_vfc |= IPV6_VERSION; 2174 ip6->ip6_nxt = IPPROTO_ICMPV6; 2175 ip6->ip6_hlim = hlim; 2176 2177 icmp6->icmp6_cksum = 0; 2178 icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2179 sizeof(struct ip6_hdr), plen); 2180 2181 /* 2182 * XXX option handling 2183 */ 2184 2185 m->m_flags &= ~(M_BCAST|M_MCAST); 2186 m->m_pkthdr.rcvif = NULL; 2187 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2188 if (outif) 2189 icmp6_ifoutstat_inc(outif, type, code); 2190 2191 return; 2192 2193 bad: 2194 m_freem(m); 2195 return; 2196 } 2197 2198 void 2199 icmp6_fasttimo(void) 2200 { 2201 2202 mld_fasttimo(); 2203 } 2204 2205 void 2206 icmp6_slowtimo(void) 2207 { 2208 2209 mld_slowtimo(); 2210 } 2211 2212 static const char * 2213 icmp6_redirect_diag(struct in6_addr *src6, struct in6_addr *dst6, 2214 struct in6_addr *tgt6) 2215 { 2216 static char buf[1024]; 2217 char ip6bufs[INET6_ADDRSTRLEN]; 2218 char ip6bufd[INET6_ADDRSTRLEN]; 2219 char ip6buft[INET6_ADDRSTRLEN]; 2220 snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)", 2221 ip6_sprintf(ip6bufs, src6), ip6_sprintf(ip6bufd, dst6), 2222 ip6_sprintf(ip6buft, tgt6)); 2223 return buf; 2224 } 2225 2226 void 2227 icmp6_redirect_input(struct mbuf *m, int off) 2228 { 2229 struct ifnet *ifp; 2230 struct ip6_hdr *ip6; 2231 struct nd_redirect *nd_rd; 2232 struct in6_addr src6; 2233 struct in6_addr redtgt6; 2234 struct in6_addr reddst6; 2235 union nd_opts ndopts; 2236 char ip6buf[INET6_ADDRSTRLEN]; 2237 char *lladdr; 2238 int icmp6len, is_onlink, is_router, lladdrlen; 2239 2240 M_ASSERTPKTHDR(m); 2241 KASSERT(m->m_pkthdr.rcvif != NULL, ("%s: no rcvif", __func__)); 2242 2243 /* XXX if we are router, we don't update route by icmp6 redirect */ 2244 if (V_ip6_forwarding) 2245 goto freeit; 2246 if (!V_icmp6_rediraccept) 2247 goto freeit; 2248 2249 /* RFC 6980: Nodes MUST silently ignore fragments */ 2250 if(m->m_flags & M_FRAGMENTED) 2251 goto freeit; 2252 2253 ip6 = mtod(m, struct ip6_hdr *); 2254 icmp6len = ntohs(ip6->ip6_plen); 2255 #ifndef PULLDOWN_TEST 2256 IP6_EXTHDR_CHECK(m, off, icmp6len,); 2257 nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off); 2258 #else 2259 IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len); 2260 if (nd_rd == NULL) { 2261 ICMP6STAT_INC(icp6s_tooshort); 2262 return; 2263 } 2264 #endif 2265 2266 ifp = m->m_pkthdr.rcvif; 2267 redtgt6 = nd_rd->nd_rd_target; 2268 reddst6 = nd_rd->nd_rd_dst; 2269 2270 if (in6_setscope(&redtgt6, ifp, NULL) || 2271 in6_setscope(&reddst6, ifp, NULL)) { 2272 goto freeit; 2273 } 2274 2275 /* validation */ 2276 src6 = ip6->ip6_src; 2277 if (!IN6_IS_ADDR_LINKLOCAL(&src6)) { 2278 nd6log((LOG_ERR, 2279 "ICMP6 redirect sent from %s rejected; " 2280 "must be from linklocal\n", 2281 ip6_sprintf(ip6buf, &src6))); 2282 goto bad; 2283 } 2284 if (ip6->ip6_hlim != 255) { 2285 nd6log((LOG_ERR, 2286 "ICMP6 redirect sent from %s rejected; " 2287 "hlim=%d (must be 255)\n", 2288 ip6_sprintf(ip6buf, &src6), ip6->ip6_hlim)); 2289 goto bad; 2290 } 2291 { 2292 /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */ 2293 struct nhop6_basic nh6; 2294 struct in6_addr kdst; 2295 uint32_t scopeid; 2296 2297 in6_splitscope(&reddst6, &kdst, &scopeid); 2298 if (fib6_lookup_nh_basic(ifp->if_fib, &kdst, scopeid, 0, 0,&nh6)==0){ 2299 if ((nh6.nh_flags & NHF_GATEWAY) == 0) { 2300 nd6log((LOG_ERR, 2301 "ICMP6 redirect rejected; no route " 2302 "with inet6 gateway found for redirect dst: %s\n", 2303 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2304 goto bad; 2305 } 2306 2307 /* 2308 * Embed scope zone id into next hop address, since 2309 * fib6_lookup_nh_basic() returns address without embedded 2310 * scope zone id. 2311 */ 2312 if (in6_setscope(&nh6.nh_addr, m->m_pkthdr.rcvif, NULL)) 2313 goto freeit; 2314 2315 if (IN6_ARE_ADDR_EQUAL(&src6, &nh6.nh_addr) == 0) { 2316 nd6log((LOG_ERR, 2317 "ICMP6 redirect rejected; " 2318 "not equal to gw-for-src=%s (must be same): " 2319 "%s\n", 2320 ip6_sprintf(ip6buf, &nh6.nh_addr), 2321 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2322 goto bad; 2323 } 2324 } else { 2325 nd6log((LOG_ERR, 2326 "ICMP6 redirect rejected; " 2327 "no route found for redirect dst: %s\n", 2328 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2329 goto bad; 2330 } 2331 } 2332 if (IN6_IS_ADDR_MULTICAST(&reddst6)) { 2333 nd6log((LOG_ERR, 2334 "ICMP6 redirect rejected; " 2335 "redirect dst must be unicast: %s\n", 2336 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2337 goto bad; 2338 } 2339 2340 is_router = is_onlink = 0; 2341 if (IN6_IS_ADDR_LINKLOCAL(&redtgt6)) 2342 is_router = 1; /* router case */ 2343 if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0) 2344 is_onlink = 1; /* on-link destination case */ 2345 if (!is_router && !is_onlink) { 2346 nd6log((LOG_ERR, 2347 "ICMP6 redirect rejected; " 2348 "neither router case nor onlink case: %s\n", 2349 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2350 goto bad; 2351 } 2352 2353 icmp6len -= sizeof(*nd_rd); 2354 nd6_option_init(nd_rd + 1, icmp6len, &ndopts); 2355 if (nd6_options(&ndopts) < 0) { 2356 nd6log((LOG_INFO, "%s: invalid ND option, rejected: %s\n", 2357 __func__, icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2358 /* nd6_options have incremented stats */ 2359 goto freeit; 2360 } 2361 2362 lladdr = NULL; 2363 lladdrlen = 0; 2364 if (ndopts.nd_opts_tgt_lladdr) { 2365 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 2366 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 2367 } 2368 2369 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 2370 nd6log((LOG_INFO, "%s: lladdrlen mismatch for %s " 2371 "(if %d, icmp6 packet %d): %s\n", 2372 __func__, ip6_sprintf(ip6buf, &redtgt6), 2373 ifp->if_addrlen, lladdrlen - 2, 2374 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2375 goto bad; 2376 } 2377 2378 /* Validation passed. */ 2379 2380 /* RFC 2461 8.3 */ 2381 nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT, 2382 is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER); 2383 2384 /* 2385 * Install a gateway route in the better-router case or an interface 2386 * route in the on-link-destination case. 2387 */ 2388 { 2389 struct sockaddr_in6 sdst; 2390 struct sockaddr_in6 sgw; 2391 struct sockaddr_in6 ssrc; 2392 struct sockaddr *gw; 2393 int rt_flags; 2394 u_int fibnum; 2395 2396 bzero(&sdst, sizeof(sdst)); 2397 bzero(&ssrc, sizeof(ssrc)); 2398 sdst.sin6_family = ssrc.sin6_family = AF_INET6; 2399 sdst.sin6_len = ssrc.sin6_len = sizeof(struct sockaddr_in6); 2400 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr)); 2401 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr)); 2402 rt_flags = RTF_HOST; 2403 if (is_router) { 2404 bzero(&sgw, sizeof(sgw)); 2405 sgw.sin6_family = AF_INET6; 2406 sgw.sin6_len = sizeof(struct sockaddr_in6); 2407 bcopy(&redtgt6, &sgw.sin6_addr, 2408 sizeof(struct in6_addr)); 2409 gw = (struct sockaddr *)&sgw; 2410 rt_flags |= RTF_GATEWAY; 2411 } else 2412 gw = ifp->if_addr->ifa_addr; 2413 for (fibnum = 0; fibnum < rt_numfibs; fibnum++) 2414 in6_rtredirect((struct sockaddr *)&sdst, gw, 2415 (struct sockaddr *)NULL, rt_flags, 2416 (struct sockaddr *)&ssrc, fibnum); 2417 } 2418 /* finally update cached route in each socket via pfctlinput */ 2419 { 2420 struct sockaddr_in6 sdst; 2421 2422 bzero(&sdst, sizeof(sdst)); 2423 sdst.sin6_family = AF_INET6; 2424 sdst.sin6_len = sizeof(struct sockaddr_in6); 2425 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr)); 2426 pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst); 2427 } 2428 2429 freeit: 2430 m_freem(m); 2431 return; 2432 2433 bad: 2434 ICMP6STAT_INC(icp6s_badredirect); 2435 m_freem(m); 2436 } 2437 2438 void 2439 icmp6_redirect_output(struct mbuf *m0, struct rtentry *rt) 2440 { 2441 struct ifnet *ifp; /* my outgoing interface */ 2442 struct in6_addr *ifp_ll6; 2443 struct in6_addr *router_ll6; 2444 struct ip6_hdr *sip6; /* m0 as struct ip6_hdr */ 2445 struct mbuf *m = NULL; /* newly allocated one */ 2446 struct m_tag *mtag; 2447 struct ip6_hdr *ip6; /* m as struct ip6_hdr */ 2448 struct nd_redirect *nd_rd; 2449 struct llentry *ln = NULL; 2450 size_t maxlen; 2451 u_char *p; 2452 struct ifnet *outif = NULL; 2453 struct sockaddr_in6 src_sa; 2454 2455 icmp6_errcount(ND_REDIRECT, 0); 2456 2457 /* if we are not router, we don't send icmp6 redirect */ 2458 if (!V_ip6_forwarding) 2459 goto fail; 2460 2461 /* sanity check */ 2462 if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp)) 2463 goto fail; 2464 2465 /* 2466 * Address check: 2467 * the source address must identify a neighbor, and 2468 * the destination address must not be a multicast address 2469 * [RFC 2461, sec 8.2] 2470 */ 2471 sip6 = mtod(m0, struct ip6_hdr *); 2472 bzero(&src_sa, sizeof(src_sa)); 2473 src_sa.sin6_family = AF_INET6; 2474 src_sa.sin6_len = sizeof(src_sa); 2475 src_sa.sin6_addr = sip6->ip6_src; 2476 if (nd6_is_addr_neighbor(&src_sa, ifp) == 0) 2477 goto fail; 2478 if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst)) 2479 goto fail; /* what should we do here? */ 2480 2481 /* rate limit */ 2482 if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0)) 2483 goto fail; 2484 2485 /* 2486 * Since we are going to append up to 1280 bytes (= IPV6_MMTU), 2487 * we almost always ask for an mbuf cluster for simplicity. 2488 * (MHLEN < IPV6_MMTU is almost always true) 2489 */ 2490 #if IPV6_MMTU >= MCLBYTES 2491 # error assumption failed about IPV6_MMTU and MCLBYTES 2492 #endif 2493 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 2494 if (m == NULL) 2495 goto fail; 2496 M_SETFIB(m, rt->rt_fibnum); 2497 maxlen = M_TRAILINGSPACE(m); 2498 maxlen = min(IPV6_MMTU, maxlen); 2499 /* just for safety */ 2500 if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) + 2501 ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) { 2502 goto fail; 2503 } 2504 2505 { 2506 /* get ip6 linklocal address for ifp(my outgoing interface). */ 2507 struct in6_ifaddr *ia; 2508 if ((ia = in6ifa_ifpforlinklocal(ifp, 2509 IN6_IFF_NOTREADY| 2510 IN6_IFF_ANYCAST)) == NULL) 2511 goto fail; 2512 ifp_ll6 = &ia->ia_addr.sin6_addr; 2513 /* XXXRW: reference released prematurely. */ 2514 ifa_free(&ia->ia_ifa); 2515 } 2516 2517 /* get ip6 linklocal address for the router. */ 2518 if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) { 2519 struct sockaddr_in6 *sin6; 2520 sin6 = (struct sockaddr_in6 *)rt->rt_gateway; 2521 router_ll6 = &sin6->sin6_addr; 2522 if (!IN6_IS_ADDR_LINKLOCAL(router_ll6)) 2523 router_ll6 = (struct in6_addr *)NULL; 2524 } else 2525 router_ll6 = (struct in6_addr *)NULL; 2526 2527 /* ip6 */ 2528 ip6 = mtod(m, struct ip6_hdr *); 2529 ip6->ip6_flow = 0; 2530 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2531 ip6->ip6_vfc |= IPV6_VERSION; 2532 /* ip6->ip6_plen will be set later */ 2533 ip6->ip6_nxt = IPPROTO_ICMPV6; 2534 ip6->ip6_hlim = 255; 2535 /* ip6->ip6_src must be linklocal addr for my outgoing if. */ 2536 bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr)); 2537 bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr)); 2538 2539 /* ND Redirect */ 2540 nd_rd = (struct nd_redirect *)(ip6 + 1); 2541 nd_rd->nd_rd_type = ND_REDIRECT; 2542 nd_rd->nd_rd_code = 0; 2543 nd_rd->nd_rd_reserved = 0; 2544 if (rt->rt_flags & RTF_GATEWAY) { 2545 /* 2546 * nd_rd->nd_rd_target must be a link-local address in 2547 * better router cases. 2548 */ 2549 if (!router_ll6) 2550 goto fail; 2551 bcopy(router_ll6, &nd_rd->nd_rd_target, 2552 sizeof(nd_rd->nd_rd_target)); 2553 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2554 sizeof(nd_rd->nd_rd_dst)); 2555 } else { 2556 /* make sure redtgt == reddst */ 2557 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target, 2558 sizeof(nd_rd->nd_rd_target)); 2559 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2560 sizeof(nd_rd->nd_rd_dst)); 2561 } 2562 2563 p = (u_char *)(nd_rd + 1); 2564 2565 if (!router_ll6) 2566 goto nolladdropt; 2567 2568 { 2569 /* target lladdr option */ 2570 int len; 2571 struct nd_opt_hdr *nd_opt; 2572 char *lladdr; 2573 2574 ln = nd6_lookup(router_ll6, 0, ifp); 2575 if (ln == NULL) 2576 goto nolladdropt; 2577 2578 len = sizeof(*nd_opt) + ifp->if_addrlen; 2579 len = (len + 7) & ~7; /* round by 8 */ 2580 /* safety check */ 2581 if (len + (p - (u_char *)ip6) > maxlen) 2582 goto nolladdropt; 2583 2584 if (ln->la_flags & LLE_VALID) { 2585 nd_opt = (struct nd_opt_hdr *)p; 2586 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 2587 nd_opt->nd_opt_len = len >> 3; 2588 lladdr = (char *)(nd_opt + 1); 2589 bcopy(ln->ll_addr, lladdr, ifp->if_addrlen); 2590 p += len; 2591 } 2592 } 2593 nolladdropt: 2594 if (ln != NULL) 2595 LLE_RUNLOCK(ln); 2596 2597 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2598 2599 /* just to be safe */ 2600 #ifdef M_DECRYPTED /*not openbsd*/ 2601 if (m0->m_flags & M_DECRYPTED) 2602 goto noredhdropt; 2603 #endif 2604 if (p - (u_char *)ip6 > maxlen) 2605 goto noredhdropt; 2606 2607 { 2608 /* redirected header option */ 2609 int len; 2610 struct nd_opt_rd_hdr *nd_opt_rh; 2611 2612 /* 2613 * compute the maximum size for icmp6 redirect header option. 2614 * XXX room for auth header? 2615 */ 2616 len = maxlen - (p - (u_char *)ip6); 2617 len &= ~7; 2618 2619 /* This is just for simplicity. */ 2620 if (m0->m_pkthdr.len != m0->m_len) { 2621 if (m0->m_next) { 2622 m_freem(m0->m_next); 2623 m0->m_next = NULL; 2624 } 2625 m0->m_pkthdr.len = m0->m_len; 2626 } 2627 2628 /* 2629 * Redirected header option spec (RFC2461 4.6.3) talks nothing 2630 * about padding/truncate rule for the original IP packet. 2631 * From the discussion on IPv6imp in Feb 1999, 2632 * the consensus was: 2633 * - "attach as much as possible" is the goal 2634 * - pad if not aligned (original size can be guessed by 2635 * original ip6 header) 2636 * Following code adds the padding if it is simple enough, 2637 * and truncates if not. 2638 */ 2639 if (m0->m_next || m0->m_pkthdr.len != m0->m_len) 2640 panic("assumption failed in %s:%d", __FILE__, 2641 __LINE__); 2642 2643 if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) { 2644 /* not enough room, truncate */ 2645 m0->m_pkthdr.len = m0->m_len = len - 2646 sizeof(*nd_opt_rh); 2647 } else { 2648 /* enough room, pad or truncate */ 2649 size_t extra; 2650 2651 extra = m0->m_pkthdr.len % 8; 2652 if (extra) { 2653 /* pad if easy enough, truncate if not */ 2654 if (8 - extra <= M_TRAILINGSPACE(m0)) { 2655 /* pad */ 2656 m0->m_len += (8 - extra); 2657 m0->m_pkthdr.len += (8 - extra); 2658 } else { 2659 /* truncate */ 2660 m0->m_pkthdr.len -= extra; 2661 m0->m_len -= extra; 2662 } 2663 } 2664 len = m0->m_pkthdr.len + sizeof(*nd_opt_rh); 2665 m0->m_pkthdr.len = m0->m_len = len - 2666 sizeof(*nd_opt_rh); 2667 } 2668 2669 nd_opt_rh = (struct nd_opt_rd_hdr *)p; 2670 bzero(nd_opt_rh, sizeof(*nd_opt_rh)); 2671 nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER; 2672 nd_opt_rh->nd_opt_rh_len = len >> 3; 2673 p += sizeof(*nd_opt_rh); 2674 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2675 2676 /* connect m0 to m */ 2677 m_tag_delete_chain(m0, NULL); 2678 m0->m_flags &= ~M_PKTHDR; 2679 m->m_next = m0; 2680 m->m_pkthdr.len = m->m_len + m0->m_len; 2681 m0 = NULL; 2682 } 2683 noredhdropt:; 2684 if (m0) { 2685 m_freem(m0); 2686 m0 = NULL; 2687 } 2688 2689 /* XXX: clear embedded link IDs in the inner header */ 2690 in6_clearscope(&sip6->ip6_src); 2691 in6_clearscope(&sip6->ip6_dst); 2692 in6_clearscope(&nd_rd->nd_rd_target); 2693 in6_clearscope(&nd_rd->nd_rd_dst); 2694 2695 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr)); 2696 2697 nd_rd->nd_rd_cksum = 0; 2698 nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2699 sizeof(*ip6), ntohs(ip6->ip6_plen)); 2700 2701 if (send_sendso_input_hook != NULL) { 2702 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, sizeof(unsigned short), 2703 M_NOWAIT); 2704 if (mtag == NULL) 2705 goto fail; 2706 *(unsigned short *)(mtag + 1) = nd_rd->nd_rd_type; 2707 m_tag_prepend(m, mtag); 2708 } 2709 2710 /* send the packet to outside... */ 2711 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2712 if (outif) { 2713 icmp6_ifstat_inc(outif, ifs6_out_msg); 2714 icmp6_ifstat_inc(outif, ifs6_out_redirect); 2715 } 2716 ICMP6STAT_INC(icp6s_outhist[ND_REDIRECT]); 2717 2718 return; 2719 2720 fail: 2721 if (m) 2722 m_freem(m); 2723 if (m0) 2724 m_freem(m0); 2725 } 2726 2727 /* 2728 * ICMPv6 socket option processing. 2729 */ 2730 int 2731 icmp6_ctloutput(struct socket *so, struct sockopt *sopt) 2732 { 2733 int error = 0; 2734 int optlen; 2735 struct inpcb *inp = sotoinpcb(so); 2736 int level, op, optname; 2737 2738 if (sopt) { 2739 level = sopt->sopt_level; 2740 op = sopt->sopt_dir; 2741 optname = sopt->sopt_name; 2742 optlen = sopt->sopt_valsize; 2743 } else 2744 level = op = optname = optlen = 0; 2745 2746 if (level != IPPROTO_ICMPV6) { 2747 return EINVAL; 2748 } 2749 2750 switch (op) { 2751 case PRCO_SETOPT: 2752 switch (optname) { 2753 case ICMP6_FILTER: 2754 { 2755 struct icmp6_filter ic6f; 2756 2757 if (optlen != sizeof(ic6f)) { 2758 error = EMSGSIZE; 2759 break; 2760 } 2761 error = sooptcopyin(sopt, &ic6f, optlen, optlen); 2762 if (error == 0) { 2763 INP_WLOCK(inp); 2764 *inp->in6p_icmp6filt = ic6f; 2765 INP_WUNLOCK(inp); 2766 } 2767 break; 2768 } 2769 2770 default: 2771 error = ENOPROTOOPT; 2772 break; 2773 } 2774 break; 2775 2776 case PRCO_GETOPT: 2777 switch (optname) { 2778 case ICMP6_FILTER: 2779 { 2780 struct icmp6_filter ic6f; 2781 2782 INP_RLOCK(inp); 2783 ic6f = *inp->in6p_icmp6filt; 2784 INP_RUNLOCK(inp); 2785 error = sooptcopyout(sopt, &ic6f, sizeof(ic6f)); 2786 break; 2787 } 2788 2789 default: 2790 error = ENOPROTOOPT; 2791 break; 2792 } 2793 break; 2794 } 2795 2796 return (error); 2797 } 2798 2799 /* 2800 * Perform rate limit check. 2801 * Returns 0 if it is okay to send the icmp6 packet. 2802 * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate 2803 * limitation. 2804 * 2805 * XXX per-destination/type check necessary? 2806 * 2807 * dst - not used at this moment 2808 * type - not used at this moment 2809 * code - not used at this moment 2810 */ 2811 static int 2812 icmp6_ratelimit(const struct in6_addr *dst, const int type, 2813 const int code) 2814 { 2815 int ret; 2816 2817 ret = 0; /* okay to send */ 2818 2819 /* PPS limit */ 2820 if (!ppsratecheck(&V_icmp6errppslim_last, &V_icmp6errpps_count, 2821 V_icmp6errppslim)) { 2822 /* The packet is subject to rate limit */ 2823 ret++; 2824 } 2825 2826 return ret; 2827 } 2828