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 = *mp, *n; 405 struct ifnet *ifp; 406 struct ip6_hdr *ip6, *nip6; 407 struct icmp6_hdr *icmp6, *nicmp6; 408 int off = *offp; 409 int icmp6len = m->m_pkthdr.len - *offp; 410 int code, sum, noff; 411 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 412 int ip6len, error; 413 414 ifp = m->m_pkthdr.rcvif; 415 416 #ifndef PULLDOWN_TEST 417 IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_hdr), IPPROTO_DONE); 418 /* m might change if M_LOOP. So, call mtod after this */ 419 #endif 420 421 /* 422 * Locate icmp6 structure in mbuf, and check 423 * that not corrupted and of at least minimum length 424 */ 425 426 ip6 = mtod(m, struct ip6_hdr *); 427 ip6len = sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen); 428 if (icmp6len < sizeof(struct icmp6_hdr)) { 429 ICMP6STAT_INC(icp6s_tooshort); 430 goto freeit; 431 } 432 433 /* 434 * Check multicast group membership. 435 * Note: SSM filters are not applied for ICMPv6 traffic. 436 */ 437 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 438 struct in6_multi *inm; 439 440 inm = in6m_lookup(ifp, &ip6->ip6_dst); 441 if (inm == NULL) { 442 IP6STAT_INC(ip6s_notmember); 443 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 444 goto freeit; 445 } 446 } 447 448 /* 449 * calculate the checksum 450 */ 451 #ifndef PULLDOWN_TEST 452 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off); 453 #else 454 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6)); 455 if (icmp6 == NULL) { 456 ICMP6STAT_INC(icp6s_tooshort); 457 return IPPROTO_DONE; 458 } 459 #endif 460 code = icmp6->icmp6_code; 461 462 if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) { 463 nd6log((LOG_ERR, 464 "ICMP6 checksum error(%d|%x) %s\n", 465 icmp6->icmp6_type, sum, 466 ip6_sprintf(ip6bufs, &ip6->ip6_src))); 467 ICMP6STAT_INC(icp6s_checksum); 468 goto freeit; 469 } 470 471 ICMP6STAT_INC(icp6s_inhist[icmp6->icmp6_type]); 472 icmp6_ifstat_inc(ifp, ifs6_in_msg); 473 if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK) 474 icmp6_ifstat_inc(ifp, ifs6_in_error); 475 476 switch (icmp6->icmp6_type) { 477 case ICMP6_DST_UNREACH: 478 icmp6_ifstat_inc(ifp, ifs6_in_dstunreach); 479 switch (code) { 480 case ICMP6_DST_UNREACH_NOROUTE: 481 case ICMP6_DST_UNREACH_ADDR: /* PRC_HOSTDEAD is a DOS */ 482 code = PRC_UNREACH_NET; 483 break; 484 case ICMP6_DST_UNREACH_ADMIN: 485 icmp6_ifstat_inc(ifp, ifs6_in_adminprohib); 486 code = PRC_UNREACH_ADMIN_PROHIB; 487 break; 488 case ICMP6_DST_UNREACH_BEYONDSCOPE: 489 /* I mean "source address was incorrect." */ 490 code = PRC_PARAMPROB; 491 break; 492 case ICMP6_DST_UNREACH_NOPORT: 493 code = PRC_UNREACH_PORT; 494 break; 495 default: 496 goto badcode; 497 } 498 goto deliver; 499 break; 500 501 case ICMP6_PACKET_TOO_BIG: 502 icmp6_ifstat_inc(ifp, ifs6_in_pkttoobig); 503 504 /* validation is made in icmp6_mtudisc_update */ 505 506 code = PRC_MSGSIZE; 507 508 /* 509 * Updating the path MTU will be done after examining 510 * intermediate extension headers. 511 */ 512 goto deliver; 513 break; 514 515 case ICMP6_TIME_EXCEEDED: 516 icmp6_ifstat_inc(ifp, ifs6_in_timeexceed); 517 switch (code) { 518 case ICMP6_TIME_EXCEED_TRANSIT: 519 code = PRC_TIMXCEED_INTRANS; 520 break; 521 case ICMP6_TIME_EXCEED_REASSEMBLY: 522 code = PRC_TIMXCEED_REASS; 523 break; 524 default: 525 goto badcode; 526 } 527 goto deliver; 528 break; 529 530 case ICMP6_PARAM_PROB: 531 icmp6_ifstat_inc(ifp, ifs6_in_paramprob); 532 switch (code) { 533 case ICMP6_PARAMPROB_NEXTHEADER: 534 code = PRC_UNREACH_PROTOCOL; 535 break; 536 case ICMP6_PARAMPROB_HEADER: 537 case ICMP6_PARAMPROB_OPTION: 538 code = PRC_PARAMPROB; 539 break; 540 default: 541 goto badcode; 542 } 543 goto deliver; 544 break; 545 546 case ICMP6_ECHO_REQUEST: 547 icmp6_ifstat_inc(ifp, ifs6_in_echo); 548 if (code != 0) 549 goto badcode; 550 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) { 551 /* Give up remote */ 552 break; 553 } 554 if (!M_WRITABLE(n) 555 || n->m_len < off + sizeof(struct icmp6_hdr)) { 556 struct mbuf *n0 = n; 557 int n0len; 558 559 CTASSERT(sizeof(*nip6) + sizeof(*nicmp6) <= MHLEN); 560 n = m_gethdr(M_NOWAIT, n0->m_type); 561 if (n == NULL) { 562 /* Give up remote */ 563 m_freem(n0); 564 break; 565 } 566 567 m_move_pkthdr(n, n0); /* FIB copied. */ 568 n0len = n0->m_pkthdr.len; /* save for use below */ 569 /* 570 * Copy IPv6 and ICMPv6 only. 571 */ 572 nip6 = mtod(n, struct ip6_hdr *); 573 bcopy(ip6, nip6, sizeof(struct ip6_hdr)); 574 nicmp6 = (struct icmp6_hdr *)(nip6 + 1); 575 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr)); 576 noff = sizeof(struct ip6_hdr); 577 /* new mbuf contains only ipv6+icmpv6 headers */ 578 n->m_len = noff + sizeof(struct icmp6_hdr); 579 /* 580 * Adjust mbuf. ip6_plen will be adjusted in 581 * ip6_output(). 582 */ 583 m_adj(n0, off + sizeof(struct icmp6_hdr)); 584 /* recalculate complete packet size */ 585 n->m_pkthdr.len = n0len + (noff - off); 586 n->m_next = n0; 587 } else { 588 IP6_EXTHDR_GET(nicmp6, struct icmp6_hdr *, n, off, 589 sizeof(*nicmp6)); 590 noff = off; 591 } 592 if (n) { 593 nicmp6->icmp6_type = ICMP6_ECHO_REPLY; 594 nicmp6->icmp6_code = 0; 595 ICMP6STAT_INC(icp6s_reflect); 596 ICMP6STAT_INC(icp6s_outhist[ICMP6_ECHO_REPLY]); 597 icmp6_reflect(n, noff); 598 } 599 break; 600 601 case ICMP6_ECHO_REPLY: 602 icmp6_ifstat_inc(ifp, ifs6_in_echoreply); 603 if (code != 0) 604 goto badcode; 605 break; 606 607 case MLD_LISTENER_QUERY: 608 case MLD_LISTENER_REPORT: 609 case MLD_LISTENER_DONE: 610 case MLDV2_LISTENER_REPORT: 611 /* 612 * Drop MLD traffic which is not link-local, has a hop limit 613 * of greater than 1 hop, or which does not have the 614 * IPv6 HBH Router Alert option. 615 * As IPv6 HBH options are stripped in ip6_input() we must 616 * check an mbuf header flag. 617 * XXX Should we also sanity check that these messages 618 * were directed to a link-local multicast prefix? 619 */ 620 if ((ip6->ip6_hlim != 1) || (m->m_flags & M_RTALERT_MLD) == 0) 621 goto freeit; 622 if (mld_input(m, off, icmp6len) != 0) 623 return (IPPROTO_DONE); 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 return (IPPROTO_DONE); 859 } 860 break; 861 862 badcode: 863 ICMP6STAT_INC(icp6s_badcode); 864 break; 865 866 badlen: 867 ICMP6STAT_INC(icp6s_badlen); 868 break; 869 } 870 871 /* deliver the packet to appropriate sockets */ 872 icmp6_rip6_input(&m, *offp); 873 874 return IPPROTO_DONE; 875 876 freeit: 877 m_freem(m); 878 return IPPROTO_DONE; 879 } 880 881 static int 882 icmp6_notify_error(struct mbuf **mp, int off, int icmp6len, int code) 883 { 884 struct mbuf *m = *mp; 885 struct icmp6_hdr *icmp6; 886 struct ip6_hdr *eip6; 887 u_int32_t notifymtu; 888 struct sockaddr_in6 icmp6src, icmp6dst; 889 890 if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) { 891 ICMP6STAT_INC(icp6s_tooshort); 892 goto freeit; 893 } 894 #ifndef PULLDOWN_TEST 895 IP6_EXTHDR_CHECK(m, off, 896 sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr), -1); 897 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 898 #else 899 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, 900 sizeof(*icmp6) + sizeof(struct ip6_hdr)); 901 if (icmp6 == NULL) { 902 ICMP6STAT_INC(icp6s_tooshort); 903 return (-1); 904 } 905 #endif 906 eip6 = (struct ip6_hdr *)(icmp6 + 1); 907 908 /* Detect the upper level protocol */ 909 { 910 void (*ctlfunc)(int, struct sockaddr *, void *); 911 u_int8_t nxt = eip6->ip6_nxt; 912 int eoff = off + sizeof(struct icmp6_hdr) + 913 sizeof(struct ip6_hdr); 914 struct ip6ctlparam ip6cp; 915 struct in6_addr *finaldst = NULL; 916 int icmp6type = icmp6->icmp6_type; 917 struct ip6_frag *fh; 918 struct ip6_rthdr *rth; 919 struct ip6_rthdr0 *rth0; 920 int rthlen; 921 922 while (1) { /* XXX: should avoid infinite loop explicitly? */ 923 struct ip6_ext *eh; 924 925 switch (nxt) { 926 case IPPROTO_HOPOPTS: 927 case IPPROTO_DSTOPTS: 928 case IPPROTO_AH: 929 #ifndef PULLDOWN_TEST 930 IP6_EXTHDR_CHECK(m, 0, 931 eoff + sizeof(struct ip6_ext), -1); 932 eh = (struct ip6_ext *)(mtod(m, caddr_t) + eoff); 933 #else 934 IP6_EXTHDR_GET(eh, struct ip6_ext *, m, 935 eoff, sizeof(*eh)); 936 if (eh == NULL) { 937 ICMP6STAT_INC(icp6s_tooshort); 938 return (-1); 939 } 940 #endif 941 942 if (nxt == IPPROTO_AH) 943 eoff += (eh->ip6e_len + 2) << 2; 944 else 945 eoff += (eh->ip6e_len + 1) << 3; 946 nxt = eh->ip6e_nxt; 947 break; 948 case IPPROTO_ROUTING: 949 /* 950 * When the erroneous packet contains a 951 * routing header, we should examine the 952 * header to determine the final destination. 953 * Otherwise, we can't properly update 954 * information that depends on the final 955 * destination (e.g. path MTU). 956 */ 957 #ifndef PULLDOWN_TEST 958 IP6_EXTHDR_CHECK(m, 0, eoff + sizeof(*rth), -1); 959 rth = (struct ip6_rthdr *) 960 (mtod(m, caddr_t) + eoff); 961 #else 962 IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m, 963 eoff, sizeof(*rth)); 964 if (rth == NULL) { 965 ICMP6STAT_INC(icp6s_tooshort); 966 return (-1); 967 } 968 #endif 969 rthlen = (rth->ip6r_len + 1) << 3; 970 /* 971 * XXX: currently there is no 972 * officially defined type other 973 * than type-0. 974 * Note that if the segment left field 975 * is 0, all intermediate hops must 976 * have been passed. 977 */ 978 if (rth->ip6r_segleft && 979 rth->ip6r_type == IPV6_RTHDR_TYPE_0) { 980 int hops; 981 982 #ifndef PULLDOWN_TEST 983 IP6_EXTHDR_CHECK(m, 0, eoff + rthlen, -1); 984 rth0 = (struct ip6_rthdr0 *) 985 (mtod(m, caddr_t) + eoff); 986 #else 987 IP6_EXTHDR_GET(rth0, 988 struct ip6_rthdr0 *, m, 989 eoff, rthlen); 990 if (rth0 == NULL) { 991 ICMP6STAT_INC(icp6s_tooshort); 992 return (-1); 993 } 994 #endif 995 /* just ignore a bogus header */ 996 if ((rth0->ip6r0_len % 2) == 0 && 997 (hops = rth0->ip6r0_len/2)) 998 finaldst = (struct in6_addr *)(rth0 + 1) + (hops - 1); 999 } 1000 eoff += rthlen; 1001 nxt = rth->ip6r_nxt; 1002 break; 1003 case IPPROTO_FRAGMENT: 1004 #ifndef PULLDOWN_TEST 1005 IP6_EXTHDR_CHECK(m, 0, eoff + 1006 sizeof(struct ip6_frag), -1); 1007 fh = (struct ip6_frag *)(mtod(m, caddr_t) + 1008 eoff); 1009 #else 1010 IP6_EXTHDR_GET(fh, struct ip6_frag *, m, 1011 eoff, sizeof(*fh)); 1012 if (fh == NULL) { 1013 ICMP6STAT_INC(icp6s_tooshort); 1014 return (-1); 1015 } 1016 #endif 1017 /* 1018 * Data after a fragment header is meaningless 1019 * unless it is the first fragment, but 1020 * we'll go to the notify label for path MTU 1021 * discovery. 1022 */ 1023 if (fh->ip6f_offlg & IP6F_OFF_MASK) 1024 goto notify; 1025 1026 eoff += sizeof(struct ip6_frag); 1027 nxt = fh->ip6f_nxt; 1028 break; 1029 default: 1030 /* 1031 * This case includes ESP and the No Next 1032 * Header. In such cases going to the notify 1033 * label does not have any meaning 1034 * (i.e. ctlfunc will be NULL), but we go 1035 * anyway since we might have to update 1036 * path MTU information. 1037 */ 1038 goto notify; 1039 } 1040 } 1041 notify: 1042 #ifndef PULLDOWN_TEST 1043 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 1044 #else 1045 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, 1046 sizeof(*icmp6) + sizeof(struct ip6_hdr)); 1047 if (icmp6 == NULL) { 1048 ICMP6STAT_INC(icp6s_tooshort); 1049 return (-1); 1050 } 1051 #endif 1052 1053 /* 1054 * retrieve parameters from the inner IPv6 header, and convert 1055 * them into sockaddr structures. 1056 * XXX: there is no guarantee that the source or destination 1057 * addresses of the inner packet are in the same scope as 1058 * the addresses of the icmp packet. But there is no other 1059 * way to determine the zone. 1060 */ 1061 eip6 = (struct ip6_hdr *)(icmp6 + 1); 1062 1063 bzero(&icmp6dst, sizeof(icmp6dst)); 1064 icmp6dst.sin6_len = sizeof(struct sockaddr_in6); 1065 icmp6dst.sin6_family = AF_INET6; 1066 if (finaldst == NULL) 1067 icmp6dst.sin6_addr = eip6->ip6_dst; 1068 else 1069 icmp6dst.sin6_addr = *finaldst; 1070 if (in6_setscope(&icmp6dst.sin6_addr, m->m_pkthdr.rcvif, NULL)) 1071 goto freeit; 1072 bzero(&icmp6src, sizeof(icmp6src)); 1073 icmp6src.sin6_len = sizeof(struct sockaddr_in6); 1074 icmp6src.sin6_family = AF_INET6; 1075 icmp6src.sin6_addr = eip6->ip6_src; 1076 if (in6_setscope(&icmp6src.sin6_addr, m->m_pkthdr.rcvif, NULL)) 1077 goto freeit; 1078 icmp6src.sin6_flowinfo = 1079 (eip6->ip6_flow & IPV6_FLOWLABEL_MASK); 1080 1081 if (finaldst == NULL) 1082 finaldst = &eip6->ip6_dst; 1083 ip6cp.ip6c_m = m; 1084 ip6cp.ip6c_icmp6 = icmp6; 1085 ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1); 1086 ip6cp.ip6c_off = eoff; 1087 ip6cp.ip6c_finaldst = finaldst; 1088 ip6cp.ip6c_src = &icmp6src; 1089 ip6cp.ip6c_nxt = nxt; 1090 1091 if (icmp6type == ICMP6_PACKET_TOO_BIG) { 1092 notifymtu = ntohl(icmp6->icmp6_mtu); 1093 ip6cp.ip6c_cmdarg = (void *)¬ifymtu; 1094 icmp6_mtudisc_update(&ip6cp, 1); /*XXX*/ 1095 } 1096 1097 ctlfunc = (void (*)(int, struct sockaddr *, void *)) 1098 (inet6sw[ip6_protox[nxt]].pr_ctlinput); 1099 if (ctlfunc) { 1100 (void) (*ctlfunc)(code, (struct sockaddr *)&icmp6dst, 1101 &ip6cp); 1102 } 1103 } 1104 *mp = m; 1105 return (0); 1106 1107 freeit: 1108 m_freem(m); 1109 return (-1); 1110 } 1111 1112 void 1113 icmp6_mtudisc_update(struct ip6ctlparam *ip6cp, int validated) 1114 { 1115 struct in6_addr *dst = ip6cp->ip6c_finaldst; 1116 struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6; 1117 struct mbuf *m = ip6cp->ip6c_m; /* will be necessary for scope issue */ 1118 u_int mtu = ntohl(icmp6->icmp6_mtu); 1119 struct in_conninfo inc; 1120 1121 #if 0 1122 /* 1123 * RFC2460 section 5, last paragraph. 1124 * even though minimum link MTU for IPv6 is IPV6_MMTU, 1125 * we may see ICMPv6 too big with mtu < IPV6_MMTU 1126 * due to packet translator in the middle. 1127 * see ip6_output() and ip6_getpmtu() "alwaysfrag" case for 1128 * special handling. 1129 */ 1130 if (mtu < IPV6_MMTU) 1131 return; 1132 #endif 1133 1134 /* 1135 * we reject ICMPv6 too big with abnormally small value. 1136 * XXX what is the good definition of "abnormally small"? 1137 */ 1138 if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8) 1139 return; 1140 1141 if (!validated) 1142 return; 1143 1144 /* 1145 * In case the suggested mtu is less than IPV6_MMTU, we 1146 * only need to remember that it was for above mentioned 1147 * "alwaysfrag" case. 1148 * Try to be as close to the spec as possible. 1149 */ 1150 if (mtu < IPV6_MMTU) 1151 mtu = IPV6_MMTU - 8; 1152 1153 bzero(&inc, sizeof(inc)); 1154 inc.inc_fibnum = M_GETFIB(m); 1155 inc.inc_flags |= INC_ISIPV6; 1156 inc.inc6_faddr = *dst; 1157 if (in6_setscope(&inc.inc6_faddr, m->m_pkthdr.rcvif, NULL)) 1158 return; 1159 1160 if (mtu < tcp_maxmtu6(&inc, NULL)) { 1161 tcp_hc_updatemtu(&inc, mtu); 1162 ICMP6STAT_INC(icp6s_pmtuchg); 1163 } 1164 } 1165 1166 /* 1167 * Process a Node Information Query packet, based on 1168 * draft-ietf-ipngwg-icmp-name-lookups-07. 1169 * 1170 * Spec incompatibilities: 1171 * - IPv6 Subject address handling 1172 * - IPv4 Subject address handling support missing 1173 * - Proxy reply (answer even if it's not for me) 1174 * - joins NI group address at in6_ifattach() time only, does not cope 1175 * with hostname changes by sethostname(3) 1176 */ 1177 static struct mbuf * 1178 ni6_input(struct mbuf *m, int off, struct prison *pr) 1179 { 1180 struct icmp6_nodeinfo *ni6, *nni6; 1181 struct mbuf *n = NULL; 1182 u_int16_t qtype; 1183 int subjlen; 1184 int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); 1185 struct ni_reply_fqdn *fqdn; 1186 int addrs; /* for NI_QTYPE_NODEADDR */ 1187 struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */ 1188 struct in6_addr in6_subj; /* subject address */ 1189 struct ip6_hdr *ip6; 1190 int oldfqdn = 0; /* if 1, return pascal string (03 draft) */ 1191 char *subj = NULL; 1192 struct in6_ifaddr *ia6 = NULL; 1193 1194 ip6 = mtod(m, struct ip6_hdr *); 1195 #ifndef PULLDOWN_TEST 1196 ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off); 1197 #else 1198 IP6_EXTHDR_GET(ni6, struct icmp6_nodeinfo *, m, off, sizeof(*ni6)); 1199 if (ni6 == NULL) { 1200 /* m is already reclaimed */ 1201 return (NULL); 1202 } 1203 #endif 1204 1205 /* 1206 * Validate IPv6 source address. 1207 * The default configuration MUST be to refuse answering queries from 1208 * global-scope addresses according to RFC4602. 1209 * Notes: 1210 * - it's not very clear what "refuse" means; this implementation 1211 * simply drops it. 1212 * - it's not very easy to identify global-scope (unicast) addresses 1213 * since there are many prefixes for them. It should be safer 1214 * and in practice sufficient to check "all" but loopback and 1215 * link-local (note that site-local unicast was deprecated and 1216 * ULA is defined as global scope-wise) 1217 */ 1218 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_GLOBALOK) == 0 && 1219 !IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) && 1220 !IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) 1221 goto bad; 1222 1223 /* 1224 * Validate IPv6 destination address. 1225 * 1226 * The Responder must discard the Query without further processing 1227 * unless it is one of the Responder's unicast or anycast addresses, or 1228 * a link-local scope multicast address which the Responder has joined. 1229 * [RFC4602, Section 5.] 1230 */ 1231 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 1232 if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst)) 1233 goto bad; 1234 /* else it's a link-local multicast, fine */ 1235 } else { /* unicast or anycast */ 1236 ia6 = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */); 1237 if (ia6 == NULL) 1238 goto bad; /* XXX impossible */ 1239 1240 if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) && 1241 !(V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK)) { 1242 ifa_free(&ia6->ia_ifa); 1243 nd6log((LOG_DEBUG, "ni6_input: ignore node info to " 1244 "a temporary address in %s:%d", 1245 __FILE__, __LINE__)); 1246 goto bad; 1247 } 1248 ifa_free(&ia6->ia_ifa); 1249 } 1250 1251 /* validate query Subject field. */ 1252 qtype = ntohs(ni6->ni_qtype); 1253 subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo); 1254 switch (qtype) { 1255 case NI_QTYPE_NOOP: 1256 case NI_QTYPE_SUPTYPES: 1257 /* 07 draft */ 1258 if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0) 1259 break; 1260 /* FALLTHROUGH */ 1261 case NI_QTYPE_FQDN: 1262 case NI_QTYPE_NODEADDR: 1263 case NI_QTYPE_IPV4ADDR: 1264 switch (ni6->ni_code) { 1265 case ICMP6_NI_SUBJ_IPV6: 1266 #if ICMP6_NI_SUBJ_IPV6 != 0 1267 case 0: 1268 #endif 1269 /* 1270 * backward compatibility - try to accept 03 draft 1271 * format, where no Subject is present. 1272 */ 1273 if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 && 1274 subjlen == 0) { 1275 oldfqdn++; 1276 break; 1277 } 1278 #if ICMP6_NI_SUBJ_IPV6 != 0 1279 if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6) 1280 goto bad; 1281 #endif 1282 1283 if (subjlen != sizeof(struct in6_addr)) 1284 goto bad; 1285 1286 /* 1287 * Validate Subject address. 1288 * 1289 * Not sure what exactly "address belongs to the node" 1290 * means in the spec, is it just unicast, or what? 1291 * 1292 * At this moment we consider Subject address as 1293 * "belong to the node" if the Subject address equals 1294 * to the IPv6 destination address; validation for 1295 * IPv6 destination address should have done enough 1296 * check for us. 1297 * 1298 * We do not do proxy at this moment. 1299 */ 1300 /* m_pulldown instead of copy? */ 1301 m_copydata(m, off + sizeof(struct icmp6_nodeinfo), 1302 subjlen, (caddr_t)&in6_subj); 1303 if (in6_setscope(&in6_subj, m->m_pkthdr.rcvif, NULL)) 1304 goto bad; 1305 1306 subj = (char *)&in6_subj; 1307 if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &in6_subj)) 1308 break; 1309 1310 /* 1311 * XXX if we are to allow other cases, we should really 1312 * be careful about scope here. 1313 * basically, we should disallow queries toward IPv6 1314 * destination X with subject Y, 1315 * if scope(X) > scope(Y). 1316 * if we allow scope(X) > scope(Y), it will result in 1317 * information leakage across scope boundary. 1318 */ 1319 goto bad; 1320 1321 case ICMP6_NI_SUBJ_FQDN: 1322 /* 1323 * Validate Subject name with gethostname(3). 1324 * 1325 * The behavior may need some debate, since: 1326 * - we are not sure if the node has FQDN as 1327 * hostname (returned by gethostname(3)). 1328 * - the code does wildcard match for truncated names. 1329 * however, we are not sure if we want to perform 1330 * wildcard match, if gethostname(3) side has 1331 * truncated hostname. 1332 */ 1333 mtx_lock(&pr->pr_mtx); 1334 n = ni6_nametodns(pr->pr_hostname, 1335 strlen(pr->pr_hostname), 0); 1336 mtx_unlock(&pr->pr_mtx); 1337 if (!n || n->m_next || n->m_len == 0) 1338 goto bad; 1339 IP6_EXTHDR_GET(subj, char *, m, 1340 off + sizeof(struct icmp6_nodeinfo), subjlen); 1341 if (subj == NULL) 1342 goto bad; 1343 if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *), 1344 n->m_len)) { 1345 goto bad; 1346 } 1347 m_freem(n); 1348 n = NULL; 1349 break; 1350 1351 case ICMP6_NI_SUBJ_IPV4: /* XXX: to be implemented? */ 1352 default: 1353 goto bad; 1354 } 1355 break; 1356 } 1357 1358 /* refuse based on configuration. XXX ICMP6_NI_REFUSED? */ 1359 switch (qtype) { 1360 case NI_QTYPE_FQDN: 1361 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_FQDNOK) == 0) 1362 goto bad; 1363 break; 1364 case NI_QTYPE_NODEADDR: 1365 case NI_QTYPE_IPV4ADDR: 1366 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_NODEADDROK) == 0) 1367 goto bad; 1368 break; 1369 } 1370 1371 /* guess reply length */ 1372 switch (qtype) { 1373 case NI_QTYPE_NOOP: 1374 break; /* no reply data */ 1375 case NI_QTYPE_SUPTYPES: 1376 replylen += sizeof(u_int32_t); 1377 break; 1378 case NI_QTYPE_FQDN: 1379 /* XXX will append an mbuf */ 1380 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); 1381 break; 1382 case NI_QTYPE_NODEADDR: 1383 addrs = ni6_addrs(ni6, m, &ifp, (struct in6_addr *)subj); 1384 if ((replylen += addrs * (sizeof(struct in6_addr) + 1385 sizeof(u_int32_t))) > MCLBYTES) 1386 replylen = MCLBYTES; /* XXX: will truncate pkt later */ 1387 break; 1388 case NI_QTYPE_IPV4ADDR: 1389 /* unsupported - should respond with unknown Qtype? */ 1390 break; 1391 default: 1392 /* 1393 * XXX: We must return a reply with the ICMP6 code 1394 * `unknown Qtype' in this case. However we regard the case 1395 * as an FQDN query for backward compatibility. 1396 * Older versions set a random value to this field, 1397 * so it rarely varies in the defined qtypes. 1398 * But the mechanism is not reliable... 1399 * maybe we should obsolete older versions. 1400 */ 1401 qtype = NI_QTYPE_FQDN; 1402 /* XXX will append an mbuf */ 1403 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); 1404 oldfqdn++; 1405 break; 1406 } 1407 1408 /* Allocate an mbuf to reply. */ 1409 if (replylen > MCLBYTES) { 1410 /* 1411 * XXX: should we try to allocate more? But MCLBYTES 1412 * is probably much larger than IPV6_MMTU... 1413 */ 1414 goto bad; 1415 } 1416 if (replylen > MHLEN) 1417 n = m_getcl(M_NOWAIT, m->m_type, M_PKTHDR); 1418 else 1419 n = m_gethdr(M_NOWAIT, m->m_type); 1420 if (n == NULL) { 1421 m_freem(m); 1422 return (NULL); 1423 } 1424 m_move_pkthdr(n, m); /* just for recvif and FIB */ 1425 n->m_pkthdr.len = n->m_len = replylen; 1426 1427 /* copy mbuf header and IPv6 + Node Information base headers */ 1428 bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr)); 1429 nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1); 1430 bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo)); 1431 1432 /* qtype dependent procedure */ 1433 switch (qtype) { 1434 case NI_QTYPE_NOOP: 1435 nni6->ni_code = ICMP6_NI_SUCCESS; 1436 nni6->ni_flags = 0; 1437 break; 1438 case NI_QTYPE_SUPTYPES: 1439 { 1440 u_int32_t v; 1441 nni6->ni_code = ICMP6_NI_SUCCESS; 1442 nni6->ni_flags = htons(0x0000); /* raw bitmap */ 1443 /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */ 1444 v = (u_int32_t)htonl(0x0000000f); 1445 bcopy(&v, nni6 + 1, sizeof(u_int32_t)); 1446 break; 1447 } 1448 case NI_QTYPE_FQDN: 1449 nni6->ni_code = ICMP6_NI_SUCCESS; 1450 fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) + 1451 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo)); 1452 nni6->ni_flags = 0; /* XXX: meaningless TTL */ 1453 fqdn->ni_fqdn_ttl = 0; /* ditto. */ 1454 /* 1455 * XXX do we really have FQDN in hostname? 1456 */ 1457 mtx_lock(&pr->pr_mtx); 1458 n->m_next = ni6_nametodns(pr->pr_hostname, 1459 strlen(pr->pr_hostname), oldfqdn); 1460 mtx_unlock(&pr->pr_mtx); 1461 if (n->m_next == NULL) 1462 goto bad; 1463 /* XXX we assume that n->m_next is not a chain */ 1464 if (n->m_next->m_next != NULL) 1465 goto bad; 1466 n->m_pkthdr.len += n->m_next->m_len; 1467 break; 1468 case NI_QTYPE_NODEADDR: 1469 { 1470 int lenlim, copied; 1471 1472 nni6->ni_code = ICMP6_NI_SUCCESS; 1473 n->m_pkthdr.len = n->m_len = 1474 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); 1475 lenlim = M_TRAILINGSPACE(n); 1476 copied = ni6_store_addrs(ni6, nni6, ifp, lenlim); 1477 /* XXX: reset mbuf length */ 1478 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + 1479 sizeof(struct icmp6_nodeinfo) + copied; 1480 break; 1481 } 1482 default: 1483 break; /* XXX impossible! */ 1484 } 1485 1486 nni6->ni_type = ICMP6_NI_REPLY; 1487 m_freem(m); 1488 return (n); 1489 1490 bad: 1491 m_freem(m); 1492 if (n) 1493 m_freem(n); 1494 return (NULL); 1495 } 1496 1497 /* 1498 * make a mbuf with DNS-encoded string. no compression support. 1499 * 1500 * XXX names with less than 2 dots (like "foo" or "foo.section") will be 1501 * treated as truncated name (two \0 at the end). this is a wild guess. 1502 * 1503 * old - return pascal string if non-zero 1504 */ 1505 static struct mbuf * 1506 ni6_nametodns(const char *name, int namelen, int old) 1507 { 1508 struct mbuf *m; 1509 char *cp, *ep; 1510 const char *p, *q; 1511 int i, len, nterm; 1512 1513 if (old) 1514 len = namelen + 1; 1515 else 1516 len = MCLBYTES; 1517 1518 /* Because MAXHOSTNAMELEN is usually 256, we use cluster mbuf. */ 1519 if (len > MLEN) 1520 m = m_getcl(M_NOWAIT, MT_DATA, 0); 1521 else 1522 m = m_get(M_NOWAIT, MT_DATA); 1523 if (m == NULL) 1524 goto fail; 1525 1526 if (old) { 1527 m->m_len = len; 1528 *mtod(m, char *) = namelen; 1529 bcopy(name, mtod(m, char *) + 1, namelen); 1530 return m; 1531 } else { 1532 m->m_len = 0; 1533 cp = mtod(m, char *); 1534 ep = mtod(m, char *) + M_TRAILINGSPACE(m); 1535 1536 /* if not certain about my name, return empty buffer */ 1537 if (namelen == 0) 1538 return m; 1539 1540 /* 1541 * guess if it looks like shortened hostname, or FQDN. 1542 * shortened hostname needs two trailing "\0". 1543 */ 1544 i = 0; 1545 for (p = name; p < name + namelen; p++) { 1546 if (*p && *p == '.') 1547 i++; 1548 } 1549 if (i < 2) 1550 nterm = 2; 1551 else 1552 nterm = 1; 1553 1554 p = name; 1555 while (cp < ep && p < name + namelen) { 1556 i = 0; 1557 for (q = p; q < name + namelen && *q && *q != '.'; q++) 1558 i++; 1559 /* result does not fit into mbuf */ 1560 if (cp + i + 1 >= ep) 1561 goto fail; 1562 /* 1563 * DNS label length restriction, RFC1035 page 8. 1564 * "i == 0" case is included here to avoid returning 1565 * 0-length label on "foo..bar". 1566 */ 1567 if (i <= 0 || i >= 64) 1568 goto fail; 1569 *cp++ = i; 1570 bcopy(p, cp, i); 1571 cp += i; 1572 p = q; 1573 if (p < name + namelen && *p == '.') 1574 p++; 1575 } 1576 /* termination */ 1577 if (cp + nterm >= ep) 1578 goto fail; 1579 while (nterm-- > 0) 1580 *cp++ = '\0'; 1581 m->m_len = cp - mtod(m, char *); 1582 return m; 1583 } 1584 1585 panic("should not reach here"); 1586 /* NOTREACHED */ 1587 1588 fail: 1589 if (m) 1590 m_freem(m); 1591 return NULL; 1592 } 1593 1594 /* 1595 * check if two DNS-encoded string matches. takes care of truncated 1596 * form (with \0\0 at the end). no compression support. 1597 * XXX upper/lowercase match (see RFC2065) 1598 */ 1599 static int 1600 ni6_dnsmatch(const char *a, int alen, const char *b, int blen) 1601 { 1602 const char *a0, *b0; 1603 int l; 1604 1605 /* simplest case - need validation? */ 1606 if (alen == blen && bcmp(a, b, alen) == 0) 1607 return 1; 1608 1609 a0 = a; 1610 b0 = b; 1611 1612 /* termination is mandatory */ 1613 if (alen < 2 || blen < 2) 1614 return 0; 1615 if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0') 1616 return 0; 1617 alen--; 1618 blen--; 1619 1620 while (a - a0 < alen && b - b0 < blen) { 1621 if (a - a0 + 1 > alen || b - b0 + 1 > blen) 1622 return 0; 1623 1624 if ((signed char)a[0] < 0 || (signed char)b[0] < 0) 1625 return 0; 1626 /* we don't support compression yet */ 1627 if (a[0] >= 64 || b[0] >= 64) 1628 return 0; 1629 1630 /* truncated case */ 1631 if (a[0] == 0 && a - a0 == alen - 1) 1632 return 1; 1633 if (b[0] == 0 && b - b0 == blen - 1) 1634 return 1; 1635 if (a[0] == 0 || b[0] == 0) 1636 return 0; 1637 1638 if (a[0] != b[0]) 1639 return 0; 1640 l = a[0]; 1641 if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen) 1642 return 0; 1643 if (bcmp(a + 1, b + 1, l) != 0) 1644 return 0; 1645 1646 a += 1 + l; 1647 b += 1 + l; 1648 } 1649 1650 if (a - a0 == alen && b - b0 == blen) 1651 return 1; 1652 else 1653 return 0; 1654 } 1655 1656 /* 1657 * calculate the number of addresses to be returned in the node info reply. 1658 */ 1659 static int 1660 ni6_addrs(struct icmp6_nodeinfo *ni6, struct mbuf *m, struct ifnet **ifpp, 1661 struct in6_addr *subj) 1662 { 1663 struct epoch_tracker et; 1664 struct ifnet *ifp; 1665 struct in6_ifaddr *ifa6; 1666 struct ifaddr *ifa; 1667 int addrs = 0, addrsofif, iffound = 0; 1668 int niflags = ni6->ni_flags; 1669 1670 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) { 1671 switch (ni6->ni_code) { 1672 case ICMP6_NI_SUBJ_IPV6: 1673 if (subj == NULL) /* must be impossible... */ 1674 return (0); 1675 break; 1676 default: 1677 /* 1678 * XXX: we only support IPv6 subject address for 1679 * this Qtype. 1680 */ 1681 return (0); 1682 } 1683 } 1684 1685 NET_EPOCH_ENTER(et); 1686 CK_STAILQ_FOREACH(ifp, &V_ifnet, if_link) { 1687 addrsofif = 0; 1688 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 1689 if (ifa->ifa_addr->sa_family != AF_INET6) 1690 continue; 1691 ifa6 = (struct in6_ifaddr *)ifa; 1692 1693 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 && 1694 IN6_ARE_ADDR_EQUAL(subj, &ifa6->ia_addr.sin6_addr)) 1695 iffound = 1; 1696 1697 /* 1698 * IPv4-mapped addresses can only be returned by a 1699 * Node Information proxy, since they represent 1700 * addresses of IPv4-only nodes, which perforce do 1701 * not implement this protocol. 1702 * [icmp-name-lookups-07, Section 5.4] 1703 * So we don't support NI_NODEADDR_FLAG_COMPAT in 1704 * this function at this moment. 1705 */ 1706 1707 /* What do we have to do about ::1? */ 1708 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { 1709 case IPV6_ADDR_SCOPE_LINKLOCAL: 1710 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) 1711 continue; 1712 break; 1713 case IPV6_ADDR_SCOPE_SITELOCAL: 1714 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) 1715 continue; 1716 break; 1717 case IPV6_ADDR_SCOPE_GLOBAL: 1718 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) 1719 continue; 1720 break; 1721 default: 1722 continue; 1723 } 1724 1725 /* 1726 * check if anycast is okay. 1727 * XXX: just experimental. not in the spec. 1728 */ 1729 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && 1730 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) 1731 continue; /* we need only unicast addresses */ 1732 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && 1733 (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) { 1734 continue; 1735 } 1736 addrsofif++; /* count the address */ 1737 } 1738 if (iffound) { 1739 *ifpp = ifp; 1740 NET_EPOCH_EXIT(et); 1741 return (addrsofif); 1742 } 1743 1744 addrs += addrsofif; 1745 } 1746 NET_EPOCH_EXIT(et); 1747 1748 return (addrs); 1749 } 1750 1751 static int 1752 ni6_store_addrs(struct icmp6_nodeinfo *ni6, struct icmp6_nodeinfo *nni6, 1753 struct ifnet *ifp0, int resid) 1754 { 1755 struct epoch_tracker et; 1756 struct ifnet *ifp; 1757 struct in6_ifaddr *ifa6; 1758 struct ifaddr *ifa; 1759 struct ifnet *ifp_dep = NULL; 1760 int copied = 0, allow_deprecated = 0; 1761 u_char *cp = (u_char *)(nni6 + 1); 1762 int niflags = ni6->ni_flags; 1763 u_int32_t ltime; 1764 1765 if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL)) 1766 return (0); /* needless to copy */ 1767 1768 NET_EPOCH_ENTER(et); 1769 ifp = ifp0 ? ifp0 : CK_STAILQ_FIRST(&V_ifnet); 1770 again: 1771 1772 for (; ifp; ifp = CK_STAILQ_NEXT(ifp, if_link)) { 1773 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 1774 if (ifa->ifa_addr->sa_family != AF_INET6) 1775 continue; 1776 ifa6 = (struct in6_ifaddr *)ifa; 1777 1778 if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 && 1779 allow_deprecated == 0) { 1780 /* 1781 * prefererred address should be put before 1782 * deprecated addresses. 1783 */ 1784 1785 /* record the interface for later search */ 1786 if (ifp_dep == NULL) 1787 ifp_dep = ifp; 1788 1789 continue; 1790 } else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 && 1791 allow_deprecated != 0) 1792 continue; /* we now collect deprecated addrs */ 1793 1794 /* What do we have to do about ::1? */ 1795 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { 1796 case IPV6_ADDR_SCOPE_LINKLOCAL: 1797 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) 1798 continue; 1799 break; 1800 case IPV6_ADDR_SCOPE_SITELOCAL: 1801 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) 1802 continue; 1803 break; 1804 case IPV6_ADDR_SCOPE_GLOBAL: 1805 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) 1806 continue; 1807 break; 1808 default: 1809 continue; 1810 } 1811 1812 /* 1813 * check if anycast is okay. 1814 * XXX: just experimental. not in the spec. 1815 */ 1816 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && 1817 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) 1818 continue; 1819 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && 1820 (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) { 1821 continue; 1822 } 1823 1824 /* now we can copy the address */ 1825 if (resid < sizeof(struct in6_addr) + 1826 sizeof(u_int32_t)) { 1827 /* 1828 * We give up much more copy. 1829 * Set the truncate flag and return. 1830 */ 1831 nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE; 1832 NET_EPOCH_EXIT(et); 1833 return (copied); 1834 } 1835 1836 /* 1837 * Set the TTL of the address. 1838 * The TTL value should be one of the following 1839 * according to the specification: 1840 * 1841 * 1. The remaining lifetime of a DHCP lease on the 1842 * address, or 1843 * 2. The remaining Valid Lifetime of a prefix from 1844 * which the address was derived through Stateless 1845 * Autoconfiguration. 1846 * 1847 * Note that we currently do not support stateful 1848 * address configuration by DHCPv6, so the former 1849 * case can't happen. 1850 */ 1851 if (ifa6->ia6_lifetime.ia6t_expire == 0) 1852 ltime = ND6_INFINITE_LIFETIME; 1853 else { 1854 if (ifa6->ia6_lifetime.ia6t_expire > 1855 time_uptime) 1856 ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_uptime); 1857 else 1858 ltime = 0; 1859 } 1860 1861 bcopy(<ime, cp, sizeof(u_int32_t)); 1862 cp += sizeof(u_int32_t); 1863 1864 /* copy the address itself */ 1865 bcopy(&ifa6->ia_addr.sin6_addr, cp, 1866 sizeof(struct in6_addr)); 1867 in6_clearscope((struct in6_addr *)cp); /* XXX */ 1868 cp += sizeof(struct in6_addr); 1869 1870 resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t)); 1871 copied += (sizeof(struct in6_addr) + sizeof(u_int32_t)); 1872 } 1873 if (ifp0) /* we need search only on the specified IF */ 1874 break; 1875 } 1876 1877 if (allow_deprecated == 0 && ifp_dep != NULL) { 1878 ifp = ifp_dep; 1879 allow_deprecated = 1; 1880 1881 goto again; 1882 } 1883 1884 NET_EPOCH_EXIT(et); 1885 1886 return (copied); 1887 } 1888 1889 /* 1890 * XXX almost dup'ed code with rip6_input. 1891 */ 1892 static int 1893 icmp6_rip6_input(struct mbuf **mp, int off) 1894 { 1895 struct mbuf *m = *mp; 1896 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1897 struct inpcb *inp; 1898 struct inpcb *last = NULL; 1899 struct sockaddr_in6 fromsa; 1900 struct icmp6_hdr *icmp6; 1901 struct epoch_tracker et; 1902 struct mbuf *opts = NULL; 1903 1904 #ifndef PULLDOWN_TEST 1905 /* this is assumed to be safe. */ 1906 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off); 1907 #else 1908 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6)); 1909 if (icmp6 == NULL) { 1910 /* m is already reclaimed */ 1911 return (IPPROTO_DONE); 1912 } 1913 #endif 1914 1915 /* 1916 * XXX: the address may have embedded scope zone ID, which should be 1917 * hidden from applications. 1918 */ 1919 bzero(&fromsa, sizeof(fromsa)); 1920 fromsa.sin6_family = AF_INET6; 1921 fromsa.sin6_len = sizeof(struct sockaddr_in6); 1922 fromsa.sin6_addr = ip6->ip6_src; 1923 if (sa6_recoverscope(&fromsa)) { 1924 m_freem(m); 1925 return (IPPROTO_DONE); 1926 } 1927 1928 INP_INFO_RLOCK_ET(&V_ripcbinfo, et); 1929 CK_LIST_FOREACH(inp, &V_ripcb, inp_list) { 1930 if ((inp->inp_vflag & INP_IPV6) == 0) 1931 continue; 1932 if (inp->inp_ip_p != IPPROTO_ICMPV6) 1933 continue; 1934 if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr) && 1935 !IN6_ARE_ADDR_EQUAL(&inp->in6p_laddr, &ip6->ip6_dst)) 1936 continue; 1937 if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr) && 1938 !IN6_ARE_ADDR_EQUAL(&inp->in6p_faddr, &ip6->ip6_src)) 1939 continue; 1940 INP_RLOCK(inp); 1941 if (__predict_false(inp->inp_flags2 & INP_FREED)) { 1942 INP_RUNLOCK(inp); 1943 continue; 1944 } 1945 if (ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type, 1946 inp->in6p_icmp6filt)) { 1947 INP_RUNLOCK(inp); 1948 continue; 1949 } 1950 if (last != NULL) { 1951 struct mbuf *n = NULL; 1952 1953 /* 1954 * Recent network drivers tend to allocate a single 1955 * mbuf cluster, rather than to make a couple of 1956 * mbufs without clusters. Also, since the IPv6 code 1957 * path tries to avoid m_pullup(), it is highly 1958 * probable that we still have an mbuf cluster here 1959 * even though the necessary length can be stored in an 1960 * mbuf's internal buffer. 1961 * Meanwhile, the default size of the receive socket 1962 * buffer for raw sockets is not so large. This means 1963 * the possibility of packet loss is relatively higher 1964 * than before. To avoid this scenario, we copy the 1965 * received data to a separate mbuf that does not use 1966 * a cluster, if possible. 1967 * XXX: it is better to copy the data after stripping 1968 * intermediate headers. 1969 */ 1970 if ((m->m_flags & M_EXT) && m->m_next == NULL && 1971 m->m_len <= MHLEN) { 1972 n = m_get(M_NOWAIT, m->m_type); 1973 if (n != NULL) { 1974 if (m_dup_pkthdr(n, m, M_NOWAIT)) { 1975 bcopy(m->m_data, n->m_data, 1976 m->m_len); 1977 n->m_len = m->m_len; 1978 } else { 1979 m_free(n); 1980 n = NULL; 1981 } 1982 } 1983 } 1984 if (n != NULL || 1985 (n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) != NULL) { 1986 if (last->inp_flags & INP_CONTROLOPTS) 1987 ip6_savecontrol(last, n, &opts); 1988 /* strip intermediate headers */ 1989 m_adj(n, off); 1990 SOCKBUF_LOCK(&last->inp_socket->so_rcv); 1991 if (sbappendaddr_locked( 1992 &last->inp_socket->so_rcv, 1993 (struct sockaddr *)&fromsa, n, opts) 1994 == 0) { 1995 /* should notify about lost packet */ 1996 m_freem(n); 1997 if (opts) { 1998 m_freem(opts); 1999 } 2000 SOCKBUF_UNLOCK( 2001 &last->inp_socket->so_rcv); 2002 } else 2003 sorwakeup_locked(last->inp_socket); 2004 opts = NULL; 2005 } 2006 INP_RUNLOCK(last); 2007 } 2008 last = inp; 2009 } 2010 INP_INFO_RUNLOCK_ET(&V_ripcbinfo, et); 2011 if (last != NULL) { 2012 if (last->inp_flags & INP_CONTROLOPTS) 2013 ip6_savecontrol(last, m, &opts); 2014 /* strip intermediate headers */ 2015 m_adj(m, off); 2016 2017 /* avoid using mbuf clusters if possible (see above) */ 2018 if ((m->m_flags & M_EXT) && m->m_next == NULL && 2019 m->m_len <= MHLEN) { 2020 struct mbuf *n; 2021 2022 n = m_get(M_NOWAIT, m->m_type); 2023 if (n != NULL) { 2024 if (m_dup_pkthdr(n, m, M_NOWAIT)) { 2025 bcopy(m->m_data, n->m_data, m->m_len); 2026 n->m_len = m->m_len; 2027 2028 m_freem(m); 2029 m = n; 2030 } else { 2031 m_freem(n); 2032 n = NULL; 2033 } 2034 } 2035 } 2036 SOCKBUF_LOCK(&last->inp_socket->so_rcv); 2037 if (sbappendaddr_locked(&last->inp_socket->so_rcv, 2038 (struct sockaddr *)&fromsa, m, opts) == 0) { 2039 m_freem(m); 2040 if (opts) 2041 m_freem(opts); 2042 SOCKBUF_UNLOCK(&last->inp_socket->so_rcv); 2043 } else 2044 sorwakeup_locked(last->inp_socket); 2045 INP_RUNLOCK(last); 2046 } else { 2047 m_freem(m); 2048 IP6STAT_DEC(ip6s_delivered); 2049 } 2050 return IPPROTO_DONE; 2051 } 2052 2053 /* 2054 * Reflect the ip6 packet back to the source. 2055 * OFF points to the icmp6 header, counted from the top of the mbuf. 2056 */ 2057 void 2058 icmp6_reflect(struct mbuf *m, size_t off) 2059 { 2060 struct in6_addr src6, *srcp; 2061 struct ip6_hdr *ip6; 2062 struct icmp6_hdr *icmp6; 2063 struct in6_ifaddr *ia = NULL; 2064 struct ifnet *outif = NULL; 2065 int plen; 2066 int type, code, hlim; 2067 2068 /* too short to reflect */ 2069 if (off < sizeof(struct ip6_hdr)) { 2070 nd6log((LOG_DEBUG, 2071 "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n", 2072 (u_long)off, (u_long)sizeof(struct ip6_hdr), 2073 __FILE__, __LINE__)); 2074 goto bad; 2075 } 2076 2077 /* 2078 * If there are extra headers between IPv6 and ICMPv6, strip 2079 * off that header first. 2080 */ 2081 #ifdef DIAGNOSTIC 2082 if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN) 2083 panic("assumption failed in icmp6_reflect"); 2084 #endif 2085 if (off > sizeof(struct ip6_hdr)) { 2086 size_t l; 2087 struct ip6_hdr nip6; 2088 2089 l = off - sizeof(struct ip6_hdr); 2090 m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6); 2091 m_adj(m, l); 2092 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 2093 if (m->m_len < l) { 2094 if ((m = m_pullup(m, l)) == NULL) 2095 return; 2096 } 2097 bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6)); 2098 } else /* off == sizeof(struct ip6_hdr) */ { 2099 size_t l; 2100 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 2101 if (m->m_len < l) { 2102 if ((m = m_pullup(m, l)) == NULL) 2103 return; 2104 } 2105 } 2106 plen = m->m_pkthdr.len - sizeof(struct ip6_hdr); 2107 ip6 = mtod(m, struct ip6_hdr *); 2108 ip6->ip6_nxt = IPPROTO_ICMPV6; 2109 icmp6 = (struct icmp6_hdr *)(ip6 + 1); 2110 type = icmp6->icmp6_type; /* keep type for statistics */ 2111 code = icmp6->icmp6_code; /* ditto. */ 2112 hlim = 0; 2113 srcp = NULL; 2114 2115 /* 2116 * If the incoming packet was addressed directly to us (i.e. unicast), 2117 * use dst as the src for the reply. 2118 * The IN6_IFF_NOTREADY case should be VERY rare, but is possible 2119 * (for example) when we encounter an error while forwarding procedure 2120 * destined to a duplicated address of ours. 2121 */ 2122 if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 2123 ia = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */); 2124 if (ia != NULL && !(ia->ia6_flags & 2125 (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) { 2126 src6 = ia->ia_addr.sin6_addr; 2127 srcp = &src6; 2128 2129 if (m->m_pkthdr.rcvif != NULL) { 2130 /* XXX: This may not be the outgoing interface */ 2131 hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim; 2132 } else 2133 hlim = V_ip6_defhlim; 2134 } 2135 if (ia != NULL) 2136 ifa_free(&ia->ia_ifa); 2137 } 2138 2139 if (srcp == NULL) { 2140 int error; 2141 struct in6_addr dst6; 2142 uint32_t scopeid; 2143 2144 /* 2145 * This case matches to multicasts, our anycast, or unicasts 2146 * that we do not own. Select a source address based on the 2147 * source address of the erroneous packet. 2148 */ 2149 in6_splitscope(&ip6->ip6_src, &dst6, &scopeid); 2150 error = in6_selectsrc_addr(M_GETFIB(m), &dst6, 2151 scopeid, NULL, &src6, &hlim); 2152 2153 if (error) { 2154 char ip6buf[INET6_ADDRSTRLEN]; 2155 nd6log((LOG_DEBUG, 2156 "icmp6_reflect: source can't be determined: " 2157 "dst=%s, error=%d\n", 2158 ip6_sprintf(ip6buf, &ip6->ip6_dst), error)); 2159 goto bad; 2160 } 2161 srcp = &src6; 2162 } 2163 /* 2164 * ip6_input() drops a packet if its src is multicast. 2165 * So, the src is never multicast. 2166 */ 2167 ip6->ip6_dst = ip6->ip6_src; 2168 ip6->ip6_src = *srcp; 2169 ip6->ip6_flow = 0; 2170 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2171 ip6->ip6_vfc |= IPV6_VERSION; 2172 ip6->ip6_nxt = IPPROTO_ICMPV6; 2173 ip6->ip6_hlim = hlim; 2174 2175 icmp6->icmp6_cksum = 0; 2176 icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2177 sizeof(struct ip6_hdr), plen); 2178 2179 /* 2180 * XXX option handling 2181 */ 2182 2183 m->m_flags &= ~(M_BCAST|M_MCAST); 2184 m->m_pkthdr.rcvif = NULL; 2185 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2186 if (outif) 2187 icmp6_ifoutstat_inc(outif, type, code); 2188 2189 return; 2190 2191 bad: 2192 m_freem(m); 2193 return; 2194 } 2195 2196 void 2197 icmp6_fasttimo(void) 2198 { 2199 2200 mld_fasttimo(); 2201 } 2202 2203 void 2204 icmp6_slowtimo(void) 2205 { 2206 2207 mld_slowtimo(); 2208 } 2209 2210 static const char * 2211 icmp6_redirect_diag(struct in6_addr *src6, struct in6_addr *dst6, 2212 struct in6_addr *tgt6) 2213 { 2214 static char buf[1024]; 2215 char ip6bufs[INET6_ADDRSTRLEN]; 2216 char ip6bufd[INET6_ADDRSTRLEN]; 2217 char ip6buft[INET6_ADDRSTRLEN]; 2218 snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)", 2219 ip6_sprintf(ip6bufs, src6), ip6_sprintf(ip6bufd, dst6), 2220 ip6_sprintf(ip6buft, tgt6)); 2221 return buf; 2222 } 2223 2224 void 2225 icmp6_redirect_input(struct mbuf *m, int off) 2226 { 2227 struct ifnet *ifp; 2228 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 2229 struct nd_redirect *nd_rd; 2230 int icmp6len = ntohs(ip6->ip6_plen); 2231 char *lladdr = NULL; 2232 int lladdrlen = 0; 2233 int is_router; 2234 int is_onlink; 2235 struct in6_addr src6 = ip6->ip6_src; 2236 struct in6_addr redtgt6; 2237 struct in6_addr reddst6; 2238 union nd_opts ndopts; 2239 char ip6buf[INET6_ADDRSTRLEN]; 2240 2241 M_ASSERTPKTHDR(m); 2242 KASSERT(m->m_pkthdr.rcvif != NULL, ("%s: no rcvif", __func__)); 2243 2244 ifp = m->m_pkthdr.rcvif; 2245 2246 /* XXX if we are router, we don't update route by icmp6 redirect */ 2247 if (V_ip6_forwarding) 2248 goto freeit; 2249 if (!V_icmp6_rediraccept) 2250 goto freeit; 2251 2252 /* RFC 6980: Nodes MUST silently ignore fragments */ 2253 if(m->m_flags & M_FRAGMENTED) 2254 goto freeit; 2255 2256 #ifndef PULLDOWN_TEST 2257 IP6_EXTHDR_CHECK(m, off, icmp6len,); 2258 nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off); 2259 #else 2260 IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len); 2261 if (nd_rd == NULL) { 2262 ICMP6STAT_INC(icp6s_tooshort); 2263 return; 2264 } 2265 #endif 2266 redtgt6 = nd_rd->nd_rd_target; 2267 reddst6 = nd_rd->nd_rd_dst; 2268 2269 if (in6_setscope(&redtgt6, m->m_pkthdr.rcvif, NULL) || 2270 in6_setscope(&reddst6, m->m_pkthdr.rcvif, NULL)) { 2271 goto freeit; 2272 } 2273 2274 /* validation */ 2275 if (!IN6_IS_ADDR_LINKLOCAL(&src6)) { 2276 nd6log((LOG_ERR, 2277 "ICMP6 redirect sent from %s rejected; " 2278 "must be from linklocal\n", 2279 ip6_sprintf(ip6buf, &src6))); 2280 goto bad; 2281 } 2282 if (ip6->ip6_hlim != 255) { 2283 nd6log((LOG_ERR, 2284 "ICMP6 redirect sent from %s rejected; " 2285 "hlim=%d (must be 255)\n", 2286 ip6_sprintf(ip6buf, &src6), ip6->ip6_hlim)); 2287 goto bad; 2288 } 2289 { 2290 /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */ 2291 struct nhop6_basic nh6; 2292 struct in6_addr kdst; 2293 uint32_t scopeid; 2294 2295 in6_splitscope(&reddst6, &kdst, &scopeid); 2296 if (fib6_lookup_nh_basic(ifp->if_fib, &kdst, scopeid, 0, 0,&nh6)==0){ 2297 if ((nh6.nh_flags & NHF_GATEWAY) == 0) { 2298 nd6log((LOG_ERR, 2299 "ICMP6 redirect rejected; no route " 2300 "with inet6 gateway found for redirect dst: %s\n", 2301 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2302 goto bad; 2303 } 2304 2305 /* 2306 * Embed scope zone id into next hop address, since 2307 * fib6_lookup_nh_basic() returns address without embedded 2308 * scope zone id. 2309 */ 2310 if (in6_setscope(&nh6.nh_addr, m->m_pkthdr.rcvif, NULL)) 2311 goto freeit; 2312 2313 if (IN6_ARE_ADDR_EQUAL(&src6, &nh6.nh_addr) == 0) { 2314 nd6log((LOG_ERR, 2315 "ICMP6 redirect rejected; " 2316 "not equal to gw-for-src=%s (must be same): " 2317 "%s\n", 2318 ip6_sprintf(ip6buf, &nh6.nh_addr), 2319 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2320 goto bad; 2321 } 2322 } else { 2323 nd6log((LOG_ERR, 2324 "ICMP6 redirect rejected; " 2325 "no route found for redirect dst: %s\n", 2326 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2327 goto bad; 2328 } 2329 } 2330 if (IN6_IS_ADDR_MULTICAST(&reddst6)) { 2331 nd6log((LOG_ERR, 2332 "ICMP6 redirect rejected; " 2333 "redirect dst must be unicast: %s\n", 2334 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2335 goto bad; 2336 } 2337 2338 is_router = is_onlink = 0; 2339 if (IN6_IS_ADDR_LINKLOCAL(&redtgt6)) 2340 is_router = 1; /* router case */ 2341 if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0) 2342 is_onlink = 1; /* on-link destination case */ 2343 if (!is_router && !is_onlink) { 2344 nd6log((LOG_ERR, 2345 "ICMP6 redirect rejected; " 2346 "neither router case nor onlink case: %s\n", 2347 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2348 goto bad; 2349 } 2350 2351 icmp6len -= sizeof(*nd_rd); 2352 nd6_option_init(nd_rd + 1, icmp6len, &ndopts); 2353 if (nd6_options(&ndopts) < 0) { 2354 nd6log((LOG_INFO, "%s: invalid ND option, rejected: %s\n", 2355 __func__, icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2356 /* nd6_options have incremented stats */ 2357 goto freeit; 2358 } 2359 2360 if (ndopts.nd_opts_tgt_lladdr) { 2361 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 2362 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 2363 } 2364 2365 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 2366 nd6log((LOG_INFO, "%s: lladdrlen mismatch for %s " 2367 "(if %d, icmp6 packet %d): %s\n", 2368 __func__, ip6_sprintf(ip6buf, &redtgt6), 2369 ifp->if_addrlen, lladdrlen - 2, 2370 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2371 goto bad; 2372 } 2373 2374 /* Validation passed. */ 2375 2376 /* RFC 2461 8.3 */ 2377 nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT, 2378 is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER); 2379 2380 /* 2381 * Install a gateway route in the better-router case or an interface 2382 * route in the on-link-destination case. 2383 */ 2384 { 2385 struct sockaddr_in6 sdst; 2386 struct sockaddr_in6 sgw; 2387 struct sockaddr_in6 ssrc; 2388 struct sockaddr *gw; 2389 int rt_flags; 2390 u_int fibnum; 2391 2392 bzero(&sdst, sizeof(sdst)); 2393 bzero(&ssrc, sizeof(ssrc)); 2394 sdst.sin6_family = ssrc.sin6_family = AF_INET6; 2395 sdst.sin6_len = ssrc.sin6_len = sizeof(struct sockaddr_in6); 2396 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr)); 2397 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr)); 2398 rt_flags = RTF_HOST; 2399 if (is_router) { 2400 bzero(&sgw, sizeof(sgw)); 2401 sgw.sin6_family = AF_INET6; 2402 sgw.sin6_len = sizeof(struct sockaddr_in6); 2403 bcopy(&redtgt6, &sgw.sin6_addr, 2404 sizeof(struct in6_addr)); 2405 gw = (struct sockaddr *)&sgw; 2406 rt_flags |= RTF_GATEWAY; 2407 } else 2408 gw = ifp->if_addr->ifa_addr; 2409 for (fibnum = 0; fibnum < rt_numfibs; fibnum++) 2410 in6_rtredirect((struct sockaddr *)&sdst, gw, 2411 (struct sockaddr *)NULL, rt_flags, 2412 (struct sockaddr *)&ssrc, fibnum); 2413 } 2414 /* finally update cached route in each socket via pfctlinput */ 2415 { 2416 struct sockaddr_in6 sdst; 2417 2418 bzero(&sdst, sizeof(sdst)); 2419 sdst.sin6_family = AF_INET6; 2420 sdst.sin6_len = sizeof(struct sockaddr_in6); 2421 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr)); 2422 pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst); 2423 } 2424 2425 freeit: 2426 m_freem(m); 2427 return; 2428 2429 bad: 2430 ICMP6STAT_INC(icp6s_badredirect); 2431 m_freem(m); 2432 } 2433 2434 void 2435 icmp6_redirect_output(struct mbuf *m0, struct rtentry *rt) 2436 { 2437 struct ifnet *ifp; /* my outgoing interface */ 2438 struct in6_addr *ifp_ll6; 2439 struct in6_addr *router_ll6; 2440 struct ip6_hdr *sip6; /* m0 as struct ip6_hdr */ 2441 struct mbuf *m = NULL; /* newly allocated one */ 2442 struct m_tag *mtag; 2443 struct ip6_hdr *ip6; /* m as struct ip6_hdr */ 2444 struct nd_redirect *nd_rd; 2445 struct llentry *ln = NULL; 2446 size_t maxlen; 2447 u_char *p; 2448 struct ifnet *outif = NULL; 2449 struct sockaddr_in6 src_sa; 2450 2451 icmp6_errcount(ND_REDIRECT, 0); 2452 2453 /* if we are not router, we don't send icmp6 redirect */ 2454 if (!V_ip6_forwarding) 2455 goto fail; 2456 2457 /* sanity check */ 2458 if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp)) 2459 goto fail; 2460 2461 /* 2462 * Address check: 2463 * the source address must identify a neighbor, and 2464 * the destination address must not be a multicast address 2465 * [RFC 2461, sec 8.2] 2466 */ 2467 sip6 = mtod(m0, struct ip6_hdr *); 2468 bzero(&src_sa, sizeof(src_sa)); 2469 src_sa.sin6_family = AF_INET6; 2470 src_sa.sin6_len = sizeof(src_sa); 2471 src_sa.sin6_addr = sip6->ip6_src; 2472 if (nd6_is_addr_neighbor(&src_sa, ifp) == 0) 2473 goto fail; 2474 if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst)) 2475 goto fail; /* what should we do here? */ 2476 2477 /* rate limit */ 2478 if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0)) 2479 goto fail; 2480 2481 /* 2482 * Since we are going to append up to 1280 bytes (= IPV6_MMTU), 2483 * we almost always ask for an mbuf cluster for simplicity. 2484 * (MHLEN < IPV6_MMTU is almost always true) 2485 */ 2486 #if IPV6_MMTU >= MCLBYTES 2487 # error assumption failed about IPV6_MMTU and MCLBYTES 2488 #endif 2489 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 2490 if (m == NULL) 2491 goto fail; 2492 M_SETFIB(m, rt->rt_fibnum); 2493 maxlen = M_TRAILINGSPACE(m); 2494 maxlen = min(IPV6_MMTU, maxlen); 2495 /* just for safety */ 2496 if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) + 2497 ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) { 2498 goto fail; 2499 } 2500 2501 { 2502 /* get ip6 linklocal address for ifp(my outgoing interface). */ 2503 struct in6_ifaddr *ia; 2504 if ((ia = in6ifa_ifpforlinklocal(ifp, 2505 IN6_IFF_NOTREADY| 2506 IN6_IFF_ANYCAST)) == NULL) 2507 goto fail; 2508 ifp_ll6 = &ia->ia_addr.sin6_addr; 2509 /* XXXRW: reference released prematurely. */ 2510 ifa_free(&ia->ia_ifa); 2511 } 2512 2513 /* get ip6 linklocal address for the router. */ 2514 if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) { 2515 struct sockaddr_in6 *sin6; 2516 sin6 = (struct sockaddr_in6 *)rt->rt_gateway; 2517 router_ll6 = &sin6->sin6_addr; 2518 if (!IN6_IS_ADDR_LINKLOCAL(router_ll6)) 2519 router_ll6 = (struct in6_addr *)NULL; 2520 } else 2521 router_ll6 = (struct in6_addr *)NULL; 2522 2523 /* ip6 */ 2524 ip6 = mtod(m, struct ip6_hdr *); 2525 ip6->ip6_flow = 0; 2526 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2527 ip6->ip6_vfc |= IPV6_VERSION; 2528 /* ip6->ip6_plen will be set later */ 2529 ip6->ip6_nxt = IPPROTO_ICMPV6; 2530 ip6->ip6_hlim = 255; 2531 /* ip6->ip6_src must be linklocal addr for my outgoing if. */ 2532 bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr)); 2533 bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr)); 2534 2535 /* ND Redirect */ 2536 nd_rd = (struct nd_redirect *)(ip6 + 1); 2537 nd_rd->nd_rd_type = ND_REDIRECT; 2538 nd_rd->nd_rd_code = 0; 2539 nd_rd->nd_rd_reserved = 0; 2540 if (rt->rt_flags & RTF_GATEWAY) { 2541 /* 2542 * nd_rd->nd_rd_target must be a link-local address in 2543 * better router cases. 2544 */ 2545 if (!router_ll6) 2546 goto fail; 2547 bcopy(router_ll6, &nd_rd->nd_rd_target, 2548 sizeof(nd_rd->nd_rd_target)); 2549 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2550 sizeof(nd_rd->nd_rd_dst)); 2551 } else { 2552 /* make sure redtgt == reddst */ 2553 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target, 2554 sizeof(nd_rd->nd_rd_target)); 2555 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2556 sizeof(nd_rd->nd_rd_dst)); 2557 } 2558 2559 p = (u_char *)(nd_rd + 1); 2560 2561 if (!router_ll6) 2562 goto nolladdropt; 2563 2564 { 2565 /* target lladdr option */ 2566 struct epoch_tracker et; 2567 int len; 2568 struct nd_opt_hdr *nd_opt; 2569 char *lladdr; 2570 2571 NET_EPOCH_ENTER(et); 2572 ln = nd6_lookup(router_ll6, 0, ifp); 2573 NET_EPOCH_EXIT(et); 2574 if (ln == NULL) 2575 goto nolladdropt; 2576 2577 len = sizeof(*nd_opt) + ifp->if_addrlen; 2578 len = (len + 7) & ~7; /* round by 8 */ 2579 /* safety check */ 2580 if (len + (p - (u_char *)ip6) > maxlen) 2581 goto nolladdropt; 2582 2583 if (ln->la_flags & LLE_VALID) { 2584 nd_opt = (struct nd_opt_hdr *)p; 2585 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 2586 nd_opt->nd_opt_len = len >> 3; 2587 lladdr = (char *)(nd_opt + 1); 2588 bcopy(ln->ll_addr, lladdr, ifp->if_addrlen); 2589 p += len; 2590 } 2591 } 2592 nolladdropt: 2593 if (ln != NULL) 2594 LLE_RUNLOCK(ln); 2595 2596 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2597 2598 /* just to be safe */ 2599 #ifdef M_DECRYPTED /*not openbsd*/ 2600 if (m0->m_flags & M_DECRYPTED) 2601 goto noredhdropt; 2602 #endif 2603 if (p - (u_char *)ip6 > maxlen) 2604 goto noredhdropt; 2605 2606 { 2607 /* redirected header option */ 2608 int len; 2609 struct nd_opt_rd_hdr *nd_opt_rh; 2610 2611 /* 2612 * compute the maximum size for icmp6 redirect header option. 2613 * XXX room for auth header? 2614 */ 2615 len = maxlen - (p - (u_char *)ip6); 2616 len &= ~7; 2617 2618 /* This is just for simplicity. */ 2619 if (m0->m_pkthdr.len != m0->m_len) { 2620 if (m0->m_next) { 2621 m_freem(m0->m_next); 2622 m0->m_next = NULL; 2623 } 2624 m0->m_pkthdr.len = m0->m_len; 2625 } 2626 2627 /* 2628 * Redirected header option spec (RFC2461 4.6.3) talks nothing 2629 * about padding/truncate rule for the original IP packet. 2630 * From the discussion on IPv6imp in Feb 1999, 2631 * the consensus was: 2632 * - "attach as much as possible" is the goal 2633 * - pad if not aligned (original size can be guessed by 2634 * original ip6 header) 2635 * Following code adds the padding if it is simple enough, 2636 * and truncates if not. 2637 */ 2638 if (m0->m_next || m0->m_pkthdr.len != m0->m_len) 2639 panic("assumption failed in %s:%d", __FILE__, 2640 __LINE__); 2641 2642 if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) { 2643 /* not enough room, truncate */ 2644 m0->m_pkthdr.len = m0->m_len = len - 2645 sizeof(*nd_opt_rh); 2646 } else { 2647 /* enough room, pad or truncate */ 2648 size_t extra; 2649 2650 extra = m0->m_pkthdr.len % 8; 2651 if (extra) { 2652 /* pad if easy enough, truncate if not */ 2653 if (8 - extra <= M_TRAILINGSPACE(m0)) { 2654 /* pad */ 2655 m0->m_len += (8 - extra); 2656 m0->m_pkthdr.len += (8 - extra); 2657 } else { 2658 /* truncate */ 2659 m0->m_pkthdr.len -= extra; 2660 m0->m_len -= extra; 2661 } 2662 } 2663 len = m0->m_pkthdr.len + sizeof(*nd_opt_rh); 2664 m0->m_pkthdr.len = m0->m_len = len - 2665 sizeof(*nd_opt_rh); 2666 } 2667 2668 nd_opt_rh = (struct nd_opt_rd_hdr *)p; 2669 bzero(nd_opt_rh, sizeof(*nd_opt_rh)); 2670 nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER; 2671 nd_opt_rh->nd_opt_rh_len = len >> 3; 2672 p += sizeof(*nd_opt_rh); 2673 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2674 2675 /* connect m0 to m */ 2676 m_tag_delete_chain(m0, NULL); 2677 m0->m_flags &= ~M_PKTHDR; 2678 m->m_next = m0; 2679 m->m_pkthdr.len = m->m_len + m0->m_len; 2680 m0 = NULL; 2681 } 2682 noredhdropt:; 2683 if (m0) { 2684 m_freem(m0); 2685 m0 = NULL; 2686 } 2687 2688 /* XXX: clear embedded link IDs in the inner header */ 2689 in6_clearscope(&sip6->ip6_src); 2690 in6_clearscope(&sip6->ip6_dst); 2691 in6_clearscope(&nd_rd->nd_rd_target); 2692 in6_clearscope(&nd_rd->nd_rd_dst); 2693 2694 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr)); 2695 2696 nd_rd->nd_rd_cksum = 0; 2697 nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2698 sizeof(*ip6), ntohs(ip6->ip6_plen)); 2699 2700 if (send_sendso_input_hook != NULL) { 2701 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, sizeof(unsigned short), 2702 M_NOWAIT); 2703 if (mtag == NULL) 2704 goto fail; 2705 *(unsigned short *)(mtag + 1) = nd_rd->nd_rd_type; 2706 m_tag_prepend(m, mtag); 2707 } 2708 2709 /* send the packet to outside... */ 2710 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2711 if (outif) { 2712 icmp6_ifstat_inc(outif, ifs6_out_msg); 2713 icmp6_ifstat_inc(outif, ifs6_out_redirect); 2714 } 2715 ICMP6STAT_INC(icp6s_outhist[ND_REDIRECT]); 2716 2717 return; 2718 2719 fail: 2720 if (m) 2721 m_freem(m); 2722 if (m0) 2723 m_freem(m0); 2724 } 2725 2726 /* 2727 * ICMPv6 socket option processing. 2728 */ 2729 int 2730 icmp6_ctloutput(struct socket *so, struct sockopt *sopt) 2731 { 2732 int error = 0; 2733 int optlen; 2734 struct inpcb *inp = sotoinpcb(so); 2735 int level, op, optname; 2736 2737 if (sopt) { 2738 level = sopt->sopt_level; 2739 op = sopt->sopt_dir; 2740 optname = sopt->sopt_name; 2741 optlen = sopt->sopt_valsize; 2742 } else 2743 level = op = optname = optlen = 0; 2744 2745 if (level != IPPROTO_ICMPV6) { 2746 return EINVAL; 2747 } 2748 2749 switch (op) { 2750 case PRCO_SETOPT: 2751 switch (optname) { 2752 case ICMP6_FILTER: 2753 { 2754 struct icmp6_filter ic6f; 2755 2756 if (optlen != sizeof(ic6f)) { 2757 error = EMSGSIZE; 2758 break; 2759 } 2760 error = sooptcopyin(sopt, &ic6f, optlen, optlen); 2761 if (error == 0) { 2762 INP_WLOCK(inp); 2763 *inp->in6p_icmp6filt = ic6f; 2764 INP_WUNLOCK(inp); 2765 } 2766 break; 2767 } 2768 2769 default: 2770 error = ENOPROTOOPT; 2771 break; 2772 } 2773 break; 2774 2775 case PRCO_GETOPT: 2776 switch (optname) { 2777 case ICMP6_FILTER: 2778 { 2779 struct icmp6_filter ic6f; 2780 2781 INP_RLOCK(inp); 2782 ic6f = *inp->in6p_icmp6filt; 2783 INP_RUNLOCK(inp); 2784 error = sooptcopyout(sopt, &ic6f, sizeof(ic6f)); 2785 break; 2786 } 2787 2788 default: 2789 error = ENOPROTOOPT; 2790 break; 2791 } 2792 break; 2793 } 2794 2795 return (error); 2796 } 2797 2798 /* 2799 * Perform rate limit check. 2800 * Returns 0 if it is okay to send the icmp6 packet. 2801 * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate 2802 * limitation. 2803 * 2804 * XXX per-destination/type check necessary? 2805 * 2806 * dst - not used at this moment 2807 * type - not used at this moment 2808 * code - not used at this moment 2809 */ 2810 static int 2811 icmp6_ratelimit(const struct in6_addr *dst, const int type, 2812 const int code) 2813 { 2814 int ret; 2815 2816 ret = 0; /* okay to send */ 2817 2818 /* PPS limit */ 2819 if (!ppsratecheck(&V_icmp6errppslim_last, &V_icmp6errpps_count, 2820 V_icmp6errppslim)) { 2821 /* The packet is subject to rate limit */ 2822 ret++; 2823 } 2824 2825 return ret; 2826 } 2827