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 ifnet *ifp; 1664 struct in6_ifaddr *ifa6; 1665 struct ifaddr *ifa; 1666 int addrs = 0, addrsofif, iffound = 0; 1667 int niflags = ni6->ni_flags; 1668 1669 NET_EPOCH_ASSERT(); 1670 1671 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) { 1672 switch (ni6->ni_code) { 1673 case ICMP6_NI_SUBJ_IPV6: 1674 if (subj == NULL) /* must be impossible... */ 1675 return (0); 1676 break; 1677 default: 1678 /* 1679 * XXX: we only support IPv6 subject address for 1680 * this Qtype. 1681 */ 1682 return (0); 1683 } 1684 } 1685 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 return (addrsofif); 1741 } 1742 1743 addrs += addrsofif; 1744 } 1745 1746 return (addrs); 1747 } 1748 1749 static int 1750 ni6_store_addrs(struct icmp6_nodeinfo *ni6, struct icmp6_nodeinfo *nni6, 1751 struct ifnet *ifp0, int resid) 1752 { 1753 struct ifnet *ifp; 1754 struct in6_ifaddr *ifa6; 1755 struct ifaddr *ifa; 1756 struct ifnet *ifp_dep = NULL; 1757 int copied = 0, allow_deprecated = 0; 1758 u_char *cp = (u_char *)(nni6 + 1); 1759 int niflags = ni6->ni_flags; 1760 u_int32_t ltime; 1761 1762 NET_EPOCH_ASSERT(); 1763 1764 if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL)) 1765 return (0); /* needless to copy */ 1766 1767 ifp = ifp0 ? ifp0 : CK_STAILQ_FIRST(&V_ifnet); 1768 again: 1769 1770 for (; ifp; ifp = CK_STAILQ_NEXT(ifp, if_link)) { 1771 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 1772 if (ifa->ifa_addr->sa_family != AF_INET6) 1773 continue; 1774 ifa6 = (struct in6_ifaddr *)ifa; 1775 1776 if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 && 1777 allow_deprecated == 0) { 1778 /* 1779 * prefererred address should be put before 1780 * deprecated addresses. 1781 */ 1782 1783 /* record the interface for later search */ 1784 if (ifp_dep == NULL) 1785 ifp_dep = ifp; 1786 1787 continue; 1788 } else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 && 1789 allow_deprecated != 0) 1790 continue; /* we now collect deprecated addrs */ 1791 1792 /* What do we have to do about ::1? */ 1793 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { 1794 case IPV6_ADDR_SCOPE_LINKLOCAL: 1795 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) 1796 continue; 1797 break; 1798 case IPV6_ADDR_SCOPE_SITELOCAL: 1799 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) 1800 continue; 1801 break; 1802 case IPV6_ADDR_SCOPE_GLOBAL: 1803 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) 1804 continue; 1805 break; 1806 default: 1807 continue; 1808 } 1809 1810 /* 1811 * check if anycast is okay. 1812 * XXX: just experimental. not in the spec. 1813 */ 1814 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && 1815 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) 1816 continue; 1817 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && 1818 (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) { 1819 continue; 1820 } 1821 1822 /* now we can copy the address */ 1823 if (resid < sizeof(struct in6_addr) + 1824 sizeof(u_int32_t)) { 1825 /* 1826 * We give up much more copy. 1827 * Set the truncate flag and return. 1828 */ 1829 nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE; 1830 return (copied); 1831 } 1832 1833 /* 1834 * Set the TTL of the address. 1835 * The TTL value should be one of the following 1836 * according to the specification: 1837 * 1838 * 1. The remaining lifetime of a DHCP lease on the 1839 * address, or 1840 * 2. The remaining Valid Lifetime of a prefix from 1841 * which the address was derived through Stateless 1842 * Autoconfiguration. 1843 * 1844 * Note that we currently do not support stateful 1845 * address configuration by DHCPv6, so the former 1846 * case can't happen. 1847 */ 1848 if (ifa6->ia6_lifetime.ia6t_expire == 0) 1849 ltime = ND6_INFINITE_LIFETIME; 1850 else { 1851 if (ifa6->ia6_lifetime.ia6t_expire > 1852 time_uptime) 1853 ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_uptime); 1854 else 1855 ltime = 0; 1856 } 1857 1858 bcopy(<ime, cp, sizeof(u_int32_t)); 1859 cp += sizeof(u_int32_t); 1860 1861 /* copy the address itself */ 1862 bcopy(&ifa6->ia_addr.sin6_addr, cp, 1863 sizeof(struct in6_addr)); 1864 in6_clearscope((struct in6_addr *)cp); /* XXX */ 1865 cp += sizeof(struct in6_addr); 1866 1867 resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t)); 1868 copied += (sizeof(struct in6_addr) + sizeof(u_int32_t)); 1869 } 1870 if (ifp0) /* we need search only on the specified IF */ 1871 break; 1872 } 1873 1874 if (allow_deprecated == 0 && ifp_dep != NULL) { 1875 ifp = ifp_dep; 1876 allow_deprecated = 1; 1877 1878 goto again; 1879 } 1880 1881 return (copied); 1882 } 1883 1884 /* 1885 * XXX almost dup'ed code with rip6_input. 1886 */ 1887 static int 1888 icmp6_rip6_input(struct mbuf **mp, int off) 1889 { 1890 struct mbuf *m = *mp; 1891 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1892 struct inpcb *inp; 1893 struct inpcb *last = NULL; 1894 struct sockaddr_in6 fromsa; 1895 struct icmp6_hdr *icmp6; 1896 struct epoch_tracker et; 1897 struct mbuf *opts = NULL; 1898 1899 #ifndef PULLDOWN_TEST 1900 /* this is assumed to be safe. */ 1901 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off); 1902 #else 1903 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6)); 1904 if (icmp6 == NULL) { 1905 /* m is already reclaimed */ 1906 return (IPPROTO_DONE); 1907 } 1908 #endif 1909 1910 /* 1911 * XXX: the address may have embedded scope zone ID, which should be 1912 * hidden from applications. 1913 */ 1914 bzero(&fromsa, sizeof(fromsa)); 1915 fromsa.sin6_family = AF_INET6; 1916 fromsa.sin6_len = sizeof(struct sockaddr_in6); 1917 fromsa.sin6_addr = ip6->ip6_src; 1918 if (sa6_recoverscope(&fromsa)) { 1919 m_freem(m); 1920 return (IPPROTO_DONE); 1921 } 1922 1923 INP_INFO_RLOCK_ET(&V_ripcbinfo, et); 1924 CK_LIST_FOREACH(inp, &V_ripcb, inp_list) { 1925 if ((inp->inp_vflag & INP_IPV6) == 0) 1926 continue; 1927 if (inp->inp_ip_p != IPPROTO_ICMPV6) 1928 continue; 1929 if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr) && 1930 !IN6_ARE_ADDR_EQUAL(&inp->in6p_laddr, &ip6->ip6_dst)) 1931 continue; 1932 if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr) && 1933 !IN6_ARE_ADDR_EQUAL(&inp->in6p_faddr, &ip6->ip6_src)) 1934 continue; 1935 INP_RLOCK(inp); 1936 if (__predict_false(inp->inp_flags2 & INP_FREED)) { 1937 INP_RUNLOCK(inp); 1938 continue; 1939 } 1940 if (ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type, 1941 inp->in6p_icmp6filt)) { 1942 INP_RUNLOCK(inp); 1943 continue; 1944 } 1945 if (last != NULL) { 1946 struct mbuf *n = NULL; 1947 1948 /* 1949 * Recent network drivers tend to allocate a single 1950 * mbuf cluster, rather than to make a couple of 1951 * mbufs without clusters. Also, since the IPv6 code 1952 * path tries to avoid m_pullup(), it is highly 1953 * probable that we still have an mbuf cluster here 1954 * even though the necessary length can be stored in an 1955 * mbuf's internal buffer. 1956 * Meanwhile, the default size of the receive socket 1957 * buffer for raw sockets is not so large. This means 1958 * the possibility of packet loss is relatively higher 1959 * than before. To avoid this scenario, we copy the 1960 * received data to a separate mbuf that does not use 1961 * a cluster, if possible. 1962 * XXX: it is better to copy the data after stripping 1963 * intermediate headers. 1964 */ 1965 if ((m->m_flags & M_EXT) && m->m_next == NULL && 1966 m->m_len <= MHLEN) { 1967 n = m_get(M_NOWAIT, m->m_type); 1968 if (n != NULL) { 1969 if (m_dup_pkthdr(n, m, M_NOWAIT)) { 1970 bcopy(m->m_data, n->m_data, 1971 m->m_len); 1972 n->m_len = m->m_len; 1973 } else { 1974 m_free(n); 1975 n = NULL; 1976 } 1977 } 1978 } 1979 if (n != NULL || 1980 (n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) != NULL) { 1981 if (last->inp_flags & INP_CONTROLOPTS) 1982 ip6_savecontrol(last, n, &opts); 1983 /* strip intermediate headers */ 1984 m_adj(n, off); 1985 SOCKBUF_LOCK(&last->inp_socket->so_rcv); 1986 if (sbappendaddr_locked( 1987 &last->inp_socket->so_rcv, 1988 (struct sockaddr *)&fromsa, n, opts) 1989 == 0) { 1990 /* should notify about lost packet */ 1991 m_freem(n); 1992 if (opts) { 1993 m_freem(opts); 1994 } 1995 SOCKBUF_UNLOCK( 1996 &last->inp_socket->so_rcv); 1997 } else 1998 sorwakeup_locked(last->inp_socket); 1999 opts = NULL; 2000 } 2001 INP_RUNLOCK(last); 2002 } 2003 last = inp; 2004 } 2005 INP_INFO_RUNLOCK_ET(&V_ripcbinfo, et); 2006 if (last != NULL) { 2007 if (last->inp_flags & INP_CONTROLOPTS) 2008 ip6_savecontrol(last, m, &opts); 2009 /* strip intermediate headers */ 2010 m_adj(m, off); 2011 2012 /* avoid using mbuf clusters if possible (see above) */ 2013 if ((m->m_flags & M_EXT) && m->m_next == NULL && 2014 m->m_len <= MHLEN) { 2015 struct mbuf *n; 2016 2017 n = m_get(M_NOWAIT, m->m_type); 2018 if (n != NULL) { 2019 if (m_dup_pkthdr(n, m, M_NOWAIT)) { 2020 bcopy(m->m_data, n->m_data, m->m_len); 2021 n->m_len = m->m_len; 2022 2023 m_freem(m); 2024 m = n; 2025 } else { 2026 m_freem(n); 2027 n = NULL; 2028 } 2029 } 2030 } 2031 SOCKBUF_LOCK(&last->inp_socket->so_rcv); 2032 if (sbappendaddr_locked(&last->inp_socket->so_rcv, 2033 (struct sockaddr *)&fromsa, m, opts) == 0) { 2034 m_freem(m); 2035 if (opts) 2036 m_freem(opts); 2037 SOCKBUF_UNLOCK(&last->inp_socket->so_rcv); 2038 } else 2039 sorwakeup_locked(last->inp_socket); 2040 INP_RUNLOCK(last); 2041 } else { 2042 m_freem(m); 2043 IP6STAT_DEC(ip6s_delivered); 2044 } 2045 return IPPROTO_DONE; 2046 } 2047 2048 /* 2049 * Reflect the ip6 packet back to the source. 2050 * OFF points to the icmp6 header, counted from the top of the mbuf. 2051 */ 2052 void 2053 icmp6_reflect(struct mbuf *m, size_t off) 2054 { 2055 struct in6_addr src6, *srcp; 2056 struct ip6_hdr *ip6; 2057 struct icmp6_hdr *icmp6; 2058 struct in6_ifaddr *ia = NULL; 2059 struct ifnet *outif = NULL; 2060 int plen; 2061 int type, code, hlim; 2062 2063 /* too short to reflect */ 2064 if (off < sizeof(struct ip6_hdr)) { 2065 nd6log((LOG_DEBUG, 2066 "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n", 2067 (u_long)off, (u_long)sizeof(struct ip6_hdr), 2068 __FILE__, __LINE__)); 2069 goto bad; 2070 } 2071 2072 /* 2073 * If there are extra headers between IPv6 and ICMPv6, strip 2074 * off that header first. 2075 */ 2076 #ifdef DIAGNOSTIC 2077 if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN) 2078 panic("assumption failed in icmp6_reflect"); 2079 #endif 2080 if (off > sizeof(struct ip6_hdr)) { 2081 size_t l; 2082 struct ip6_hdr nip6; 2083 2084 l = off - sizeof(struct ip6_hdr); 2085 m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6); 2086 m_adj(m, l); 2087 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 2088 if (m->m_len < l) { 2089 if ((m = m_pullup(m, l)) == NULL) 2090 return; 2091 } 2092 bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6)); 2093 } else /* off == sizeof(struct ip6_hdr) */ { 2094 size_t l; 2095 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 2096 if (m->m_len < l) { 2097 if ((m = m_pullup(m, l)) == NULL) 2098 return; 2099 } 2100 } 2101 plen = m->m_pkthdr.len - sizeof(struct ip6_hdr); 2102 ip6 = mtod(m, struct ip6_hdr *); 2103 ip6->ip6_nxt = IPPROTO_ICMPV6; 2104 icmp6 = (struct icmp6_hdr *)(ip6 + 1); 2105 type = icmp6->icmp6_type; /* keep type for statistics */ 2106 code = icmp6->icmp6_code; /* ditto. */ 2107 hlim = 0; 2108 srcp = NULL; 2109 2110 /* 2111 * If the incoming packet was addressed directly to us (i.e. unicast), 2112 * use dst as the src for the reply. 2113 * The IN6_IFF_NOTREADY case should be VERY rare, but is possible 2114 * (for example) when we encounter an error while forwarding procedure 2115 * destined to a duplicated address of ours. 2116 */ 2117 if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 2118 ia = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */); 2119 if (ia != NULL && !(ia->ia6_flags & 2120 (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) { 2121 src6 = ia->ia_addr.sin6_addr; 2122 srcp = &src6; 2123 2124 if (m->m_pkthdr.rcvif != NULL) { 2125 /* XXX: This may not be the outgoing interface */ 2126 hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim; 2127 } else 2128 hlim = V_ip6_defhlim; 2129 } 2130 if (ia != NULL) 2131 ifa_free(&ia->ia_ifa); 2132 } 2133 2134 if (srcp == NULL) { 2135 int error; 2136 struct in6_addr dst6; 2137 uint32_t scopeid; 2138 2139 /* 2140 * This case matches to multicasts, our anycast, or unicasts 2141 * that we do not own. Select a source address based on the 2142 * source address of the erroneous packet. 2143 */ 2144 in6_splitscope(&ip6->ip6_src, &dst6, &scopeid); 2145 error = in6_selectsrc_addr(M_GETFIB(m), &dst6, 2146 scopeid, NULL, &src6, &hlim); 2147 2148 if (error) { 2149 char ip6buf[INET6_ADDRSTRLEN]; 2150 nd6log((LOG_DEBUG, 2151 "icmp6_reflect: source can't be determined: " 2152 "dst=%s, error=%d\n", 2153 ip6_sprintf(ip6buf, &ip6->ip6_dst), error)); 2154 goto bad; 2155 } 2156 srcp = &src6; 2157 } 2158 /* 2159 * ip6_input() drops a packet if its src is multicast. 2160 * So, the src is never multicast. 2161 */ 2162 ip6->ip6_dst = ip6->ip6_src; 2163 ip6->ip6_src = *srcp; 2164 ip6->ip6_flow = 0; 2165 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2166 ip6->ip6_vfc |= IPV6_VERSION; 2167 ip6->ip6_nxt = IPPROTO_ICMPV6; 2168 ip6->ip6_hlim = hlim; 2169 2170 icmp6->icmp6_cksum = 0; 2171 icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2172 sizeof(struct ip6_hdr), plen); 2173 2174 /* 2175 * XXX option handling 2176 */ 2177 2178 m->m_flags &= ~(M_BCAST|M_MCAST); 2179 m->m_pkthdr.rcvif = NULL; 2180 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2181 if (outif) 2182 icmp6_ifoutstat_inc(outif, type, code); 2183 2184 return; 2185 2186 bad: 2187 m_freem(m); 2188 return; 2189 } 2190 2191 void 2192 icmp6_fasttimo(void) 2193 { 2194 2195 mld_fasttimo(); 2196 } 2197 2198 void 2199 icmp6_slowtimo(void) 2200 { 2201 2202 mld_slowtimo(); 2203 } 2204 2205 static const char * 2206 icmp6_redirect_diag(struct in6_addr *src6, struct in6_addr *dst6, 2207 struct in6_addr *tgt6) 2208 { 2209 static char buf[1024]; 2210 char ip6bufs[INET6_ADDRSTRLEN]; 2211 char ip6bufd[INET6_ADDRSTRLEN]; 2212 char ip6buft[INET6_ADDRSTRLEN]; 2213 snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)", 2214 ip6_sprintf(ip6bufs, src6), ip6_sprintf(ip6bufd, dst6), 2215 ip6_sprintf(ip6buft, tgt6)); 2216 return buf; 2217 } 2218 2219 void 2220 icmp6_redirect_input(struct mbuf *m, int off) 2221 { 2222 struct ifnet *ifp; 2223 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 2224 struct nd_redirect *nd_rd; 2225 int icmp6len = ntohs(ip6->ip6_plen); 2226 char *lladdr = NULL; 2227 int lladdrlen = 0; 2228 int is_router; 2229 int is_onlink; 2230 struct in6_addr src6 = ip6->ip6_src; 2231 struct in6_addr redtgt6; 2232 struct in6_addr reddst6; 2233 union nd_opts ndopts; 2234 char ip6buf[INET6_ADDRSTRLEN]; 2235 2236 M_ASSERTPKTHDR(m); 2237 KASSERT(m->m_pkthdr.rcvif != NULL, ("%s: no rcvif", __func__)); 2238 2239 ifp = m->m_pkthdr.rcvif; 2240 2241 /* XXX if we are router, we don't update route by icmp6 redirect */ 2242 if (V_ip6_forwarding) 2243 goto freeit; 2244 if (!V_icmp6_rediraccept) 2245 goto freeit; 2246 2247 /* RFC 6980: Nodes MUST silently ignore fragments */ 2248 if(m->m_flags & M_FRAGMENTED) 2249 goto freeit; 2250 2251 #ifndef PULLDOWN_TEST 2252 IP6_EXTHDR_CHECK(m, off, icmp6len,); 2253 nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off); 2254 #else 2255 IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len); 2256 if (nd_rd == NULL) { 2257 ICMP6STAT_INC(icp6s_tooshort); 2258 return; 2259 } 2260 #endif 2261 redtgt6 = nd_rd->nd_rd_target; 2262 reddst6 = nd_rd->nd_rd_dst; 2263 2264 if (in6_setscope(&redtgt6, m->m_pkthdr.rcvif, NULL) || 2265 in6_setscope(&reddst6, m->m_pkthdr.rcvif, NULL)) { 2266 goto freeit; 2267 } 2268 2269 /* validation */ 2270 if (!IN6_IS_ADDR_LINKLOCAL(&src6)) { 2271 nd6log((LOG_ERR, 2272 "ICMP6 redirect sent from %s rejected; " 2273 "must be from linklocal\n", 2274 ip6_sprintf(ip6buf, &src6))); 2275 goto bad; 2276 } 2277 if (ip6->ip6_hlim != 255) { 2278 nd6log((LOG_ERR, 2279 "ICMP6 redirect sent from %s rejected; " 2280 "hlim=%d (must be 255)\n", 2281 ip6_sprintf(ip6buf, &src6), ip6->ip6_hlim)); 2282 goto bad; 2283 } 2284 { 2285 /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */ 2286 struct nhop6_basic nh6; 2287 struct in6_addr kdst; 2288 uint32_t scopeid; 2289 2290 in6_splitscope(&reddst6, &kdst, &scopeid); 2291 if (fib6_lookup_nh_basic(ifp->if_fib, &kdst, scopeid, 0, 0,&nh6)==0){ 2292 if ((nh6.nh_flags & NHF_GATEWAY) == 0) { 2293 nd6log((LOG_ERR, 2294 "ICMP6 redirect rejected; no route " 2295 "with inet6 gateway found for redirect dst: %s\n", 2296 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2297 goto bad; 2298 } 2299 2300 /* 2301 * Embed scope zone id into next hop address, since 2302 * fib6_lookup_nh_basic() returns address without embedded 2303 * scope zone id. 2304 */ 2305 if (in6_setscope(&nh6.nh_addr, m->m_pkthdr.rcvif, NULL)) 2306 goto freeit; 2307 2308 if (IN6_ARE_ADDR_EQUAL(&src6, &nh6.nh_addr) == 0) { 2309 nd6log((LOG_ERR, 2310 "ICMP6 redirect rejected; " 2311 "not equal to gw-for-src=%s (must be same): " 2312 "%s\n", 2313 ip6_sprintf(ip6buf, &nh6.nh_addr), 2314 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2315 goto bad; 2316 } 2317 } else { 2318 nd6log((LOG_ERR, 2319 "ICMP6 redirect rejected; " 2320 "no route found for redirect dst: %s\n", 2321 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2322 goto bad; 2323 } 2324 } 2325 if (IN6_IS_ADDR_MULTICAST(&reddst6)) { 2326 nd6log((LOG_ERR, 2327 "ICMP6 redirect rejected; " 2328 "redirect dst must be unicast: %s\n", 2329 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2330 goto bad; 2331 } 2332 2333 is_router = is_onlink = 0; 2334 if (IN6_IS_ADDR_LINKLOCAL(&redtgt6)) 2335 is_router = 1; /* router case */ 2336 if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0) 2337 is_onlink = 1; /* on-link destination case */ 2338 if (!is_router && !is_onlink) { 2339 nd6log((LOG_ERR, 2340 "ICMP6 redirect rejected; " 2341 "neither router case nor onlink case: %s\n", 2342 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2343 goto bad; 2344 } 2345 2346 icmp6len -= sizeof(*nd_rd); 2347 nd6_option_init(nd_rd + 1, icmp6len, &ndopts); 2348 if (nd6_options(&ndopts) < 0) { 2349 nd6log((LOG_INFO, "%s: invalid ND option, rejected: %s\n", 2350 __func__, icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2351 /* nd6_options have incremented stats */ 2352 goto freeit; 2353 } 2354 2355 if (ndopts.nd_opts_tgt_lladdr) { 2356 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 2357 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 2358 } 2359 2360 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 2361 nd6log((LOG_INFO, "%s: lladdrlen mismatch for %s " 2362 "(if %d, icmp6 packet %d): %s\n", 2363 __func__, ip6_sprintf(ip6buf, &redtgt6), 2364 ifp->if_addrlen, lladdrlen - 2, 2365 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2366 goto bad; 2367 } 2368 2369 /* Validation passed. */ 2370 2371 /* RFC 2461 8.3 */ 2372 nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT, 2373 is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER); 2374 2375 /* 2376 * Install a gateway route in the better-router case or an interface 2377 * route in the on-link-destination case. 2378 */ 2379 { 2380 struct sockaddr_in6 sdst; 2381 struct sockaddr_in6 sgw; 2382 struct sockaddr_in6 ssrc; 2383 struct sockaddr *gw; 2384 int rt_flags; 2385 u_int fibnum; 2386 2387 bzero(&sdst, sizeof(sdst)); 2388 bzero(&ssrc, sizeof(ssrc)); 2389 sdst.sin6_family = ssrc.sin6_family = AF_INET6; 2390 sdst.sin6_len = ssrc.sin6_len = sizeof(struct sockaddr_in6); 2391 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr)); 2392 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr)); 2393 rt_flags = RTF_HOST; 2394 if (is_router) { 2395 bzero(&sgw, sizeof(sgw)); 2396 sgw.sin6_family = AF_INET6; 2397 sgw.sin6_len = sizeof(struct sockaddr_in6); 2398 bcopy(&redtgt6, &sgw.sin6_addr, 2399 sizeof(struct in6_addr)); 2400 gw = (struct sockaddr *)&sgw; 2401 rt_flags |= RTF_GATEWAY; 2402 } else 2403 gw = ifp->if_addr->ifa_addr; 2404 for (fibnum = 0; fibnum < rt_numfibs; fibnum++) 2405 in6_rtredirect((struct sockaddr *)&sdst, gw, 2406 (struct sockaddr *)NULL, rt_flags, 2407 (struct sockaddr *)&ssrc, fibnum); 2408 } 2409 /* finally update cached route in each socket via pfctlinput */ 2410 { 2411 struct sockaddr_in6 sdst; 2412 2413 bzero(&sdst, sizeof(sdst)); 2414 sdst.sin6_family = AF_INET6; 2415 sdst.sin6_len = sizeof(struct sockaddr_in6); 2416 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr)); 2417 pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst); 2418 } 2419 2420 freeit: 2421 m_freem(m); 2422 return; 2423 2424 bad: 2425 ICMP6STAT_INC(icp6s_badredirect); 2426 m_freem(m); 2427 } 2428 2429 void 2430 icmp6_redirect_output(struct mbuf *m0, struct rtentry *rt) 2431 { 2432 struct ifnet *ifp; /* my outgoing interface */ 2433 struct in6_addr *ifp_ll6; 2434 struct in6_addr *router_ll6; 2435 struct ip6_hdr *sip6; /* m0 as struct ip6_hdr */ 2436 struct mbuf *m = NULL; /* newly allocated one */ 2437 struct m_tag *mtag; 2438 struct ip6_hdr *ip6; /* m as struct ip6_hdr */ 2439 struct nd_redirect *nd_rd; 2440 struct llentry *ln = NULL; 2441 size_t maxlen; 2442 u_char *p; 2443 struct ifnet *outif = NULL; 2444 struct sockaddr_in6 src_sa; 2445 2446 icmp6_errcount(ND_REDIRECT, 0); 2447 2448 /* if we are not router, we don't send icmp6 redirect */ 2449 if (!V_ip6_forwarding) 2450 goto fail; 2451 2452 /* sanity check */ 2453 if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp)) 2454 goto fail; 2455 2456 /* 2457 * Address check: 2458 * the source address must identify a neighbor, and 2459 * the destination address must not be a multicast address 2460 * [RFC 2461, sec 8.2] 2461 */ 2462 sip6 = mtod(m0, struct ip6_hdr *); 2463 bzero(&src_sa, sizeof(src_sa)); 2464 src_sa.sin6_family = AF_INET6; 2465 src_sa.sin6_len = sizeof(src_sa); 2466 src_sa.sin6_addr = sip6->ip6_src; 2467 if (nd6_is_addr_neighbor(&src_sa, ifp) == 0) 2468 goto fail; 2469 if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst)) 2470 goto fail; /* what should we do here? */ 2471 2472 /* rate limit */ 2473 if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0)) 2474 goto fail; 2475 2476 /* 2477 * Since we are going to append up to 1280 bytes (= IPV6_MMTU), 2478 * we almost always ask for an mbuf cluster for simplicity. 2479 * (MHLEN < IPV6_MMTU is almost always true) 2480 */ 2481 #if IPV6_MMTU >= MCLBYTES 2482 # error assumption failed about IPV6_MMTU and MCLBYTES 2483 #endif 2484 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 2485 if (m == NULL) 2486 goto fail; 2487 M_SETFIB(m, rt->rt_fibnum); 2488 maxlen = M_TRAILINGSPACE(m); 2489 maxlen = min(IPV6_MMTU, maxlen); 2490 /* just for safety */ 2491 if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) + 2492 ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) { 2493 goto fail; 2494 } 2495 2496 { 2497 /* get ip6 linklocal address for ifp(my outgoing interface). */ 2498 struct in6_ifaddr *ia; 2499 if ((ia = in6ifa_ifpforlinklocal(ifp, 2500 IN6_IFF_NOTREADY| 2501 IN6_IFF_ANYCAST)) == NULL) 2502 goto fail; 2503 ifp_ll6 = &ia->ia_addr.sin6_addr; 2504 /* XXXRW: reference released prematurely. */ 2505 ifa_free(&ia->ia_ifa); 2506 } 2507 2508 /* get ip6 linklocal address for the router. */ 2509 if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) { 2510 struct sockaddr_in6 *sin6; 2511 sin6 = (struct sockaddr_in6 *)rt->rt_gateway; 2512 router_ll6 = &sin6->sin6_addr; 2513 if (!IN6_IS_ADDR_LINKLOCAL(router_ll6)) 2514 router_ll6 = (struct in6_addr *)NULL; 2515 } else 2516 router_ll6 = (struct in6_addr *)NULL; 2517 2518 /* ip6 */ 2519 ip6 = mtod(m, struct ip6_hdr *); 2520 ip6->ip6_flow = 0; 2521 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2522 ip6->ip6_vfc |= IPV6_VERSION; 2523 /* ip6->ip6_plen will be set later */ 2524 ip6->ip6_nxt = IPPROTO_ICMPV6; 2525 ip6->ip6_hlim = 255; 2526 /* ip6->ip6_src must be linklocal addr for my outgoing if. */ 2527 bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr)); 2528 bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr)); 2529 2530 /* ND Redirect */ 2531 nd_rd = (struct nd_redirect *)(ip6 + 1); 2532 nd_rd->nd_rd_type = ND_REDIRECT; 2533 nd_rd->nd_rd_code = 0; 2534 nd_rd->nd_rd_reserved = 0; 2535 if (rt->rt_flags & RTF_GATEWAY) { 2536 /* 2537 * nd_rd->nd_rd_target must be a link-local address in 2538 * better router cases. 2539 */ 2540 if (!router_ll6) 2541 goto fail; 2542 bcopy(router_ll6, &nd_rd->nd_rd_target, 2543 sizeof(nd_rd->nd_rd_target)); 2544 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2545 sizeof(nd_rd->nd_rd_dst)); 2546 } else { 2547 /* make sure redtgt == reddst */ 2548 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target, 2549 sizeof(nd_rd->nd_rd_target)); 2550 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2551 sizeof(nd_rd->nd_rd_dst)); 2552 } 2553 2554 p = (u_char *)(nd_rd + 1); 2555 2556 if (!router_ll6) 2557 goto nolladdropt; 2558 2559 { 2560 /* target lladdr option */ 2561 int len; 2562 struct nd_opt_hdr *nd_opt; 2563 char *lladdr; 2564 2565 ln = nd6_lookup(router_ll6, 0, ifp); 2566 if (ln == NULL) 2567 goto nolladdropt; 2568 2569 len = sizeof(*nd_opt) + ifp->if_addrlen; 2570 len = (len + 7) & ~7; /* round by 8 */ 2571 /* safety check */ 2572 if (len + (p - (u_char *)ip6) > maxlen) 2573 goto nolladdropt; 2574 2575 if (ln->la_flags & LLE_VALID) { 2576 nd_opt = (struct nd_opt_hdr *)p; 2577 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 2578 nd_opt->nd_opt_len = len >> 3; 2579 lladdr = (char *)(nd_opt + 1); 2580 bcopy(ln->ll_addr, lladdr, ifp->if_addrlen); 2581 p += len; 2582 } 2583 } 2584 nolladdropt: 2585 if (ln != NULL) 2586 LLE_RUNLOCK(ln); 2587 2588 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2589 2590 /* just to be safe */ 2591 #ifdef M_DECRYPTED /*not openbsd*/ 2592 if (m0->m_flags & M_DECRYPTED) 2593 goto noredhdropt; 2594 #endif 2595 if (p - (u_char *)ip6 > maxlen) 2596 goto noredhdropt; 2597 2598 { 2599 /* redirected header option */ 2600 int len; 2601 struct nd_opt_rd_hdr *nd_opt_rh; 2602 2603 /* 2604 * compute the maximum size for icmp6 redirect header option. 2605 * XXX room for auth header? 2606 */ 2607 len = maxlen - (p - (u_char *)ip6); 2608 len &= ~7; 2609 2610 /* This is just for simplicity. */ 2611 if (m0->m_pkthdr.len != m0->m_len) { 2612 if (m0->m_next) { 2613 m_freem(m0->m_next); 2614 m0->m_next = NULL; 2615 } 2616 m0->m_pkthdr.len = m0->m_len; 2617 } 2618 2619 /* 2620 * Redirected header option spec (RFC2461 4.6.3) talks nothing 2621 * about padding/truncate rule for the original IP packet. 2622 * From the discussion on IPv6imp in Feb 1999, 2623 * the consensus was: 2624 * - "attach as much as possible" is the goal 2625 * - pad if not aligned (original size can be guessed by 2626 * original ip6 header) 2627 * Following code adds the padding if it is simple enough, 2628 * and truncates if not. 2629 */ 2630 if (m0->m_next || m0->m_pkthdr.len != m0->m_len) 2631 panic("assumption failed in %s:%d", __FILE__, 2632 __LINE__); 2633 2634 if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) { 2635 /* not enough room, truncate */ 2636 m0->m_pkthdr.len = m0->m_len = len - 2637 sizeof(*nd_opt_rh); 2638 } else { 2639 /* enough room, pad or truncate */ 2640 size_t extra; 2641 2642 extra = m0->m_pkthdr.len % 8; 2643 if (extra) { 2644 /* pad if easy enough, truncate if not */ 2645 if (8 - extra <= M_TRAILINGSPACE(m0)) { 2646 /* pad */ 2647 m0->m_len += (8 - extra); 2648 m0->m_pkthdr.len += (8 - extra); 2649 } else { 2650 /* truncate */ 2651 m0->m_pkthdr.len -= extra; 2652 m0->m_len -= extra; 2653 } 2654 } 2655 len = m0->m_pkthdr.len + sizeof(*nd_opt_rh); 2656 m0->m_pkthdr.len = m0->m_len = len - 2657 sizeof(*nd_opt_rh); 2658 } 2659 2660 nd_opt_rh = (struct nd_opt_rd_hdr *)p; 2661 bzero(nd_opt_rh, sizeof(*nd_opt_rh)); 2662 nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER; 2663 nd_opt_rh->nd_opt_rh_len = len >> 3; 2664 p += sizeof(*nd_opt_rh); 2665 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2666 2667 /* connect m0 to m */ 2668 m_tag_delete_chain(m0, NULL); 2669 m0->m_flags &= ~M_PKTHDR; 2670 m->m_next = m0; 2671 m->m_pkthdr.len = m->m_len + m0->m_len; 2672 m0 = NULL; 2673 } 2674 noredhdropt:; 2675 if (m0) { 2676 m_freem(m0); 2677 m0 = NULL; 2678 } 2679 2680 /* XXX: clear embedded link IDs in the inner header */ 2681 in6_clearscope(&sip6->ip6_src); 2682 in6_clearscope(&sip6->ip6_dst); 2683 in6_clearscope(&nd_rd->nd_rd_target); 2684 in6_clearscope(&nd_rd->nd_rd_dst); 2685 2686 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr)); 2687 2688 nd_rd->nd_rd_cksum = 0; 2689 nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2690 sizeof(*ip6), ntohs(ip6->ip6_plen)); 2691 2692 if (send_sendso_input_hook != NULL) { 2693 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, sizeof(unsigned short), 2694 M_NOWAIT); 2695 if (mtag == NULL) 2696 goto fail; 2697 *(unsigned short *)(mtag + 1) = nd_rd->nd_rd_type; 2698 m_tag_prepend(m, mtag); 2699 } 2700 2701 /* send the packet to outside... */ 2702 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2703 if (outif) { 2704 icmp6_ifstat_inc(outif, ifs6_out_msg); 2705 icmp6_ifstat_inc(outif, ifs6_out_redirect); 2706 } 2707 ICMP6STAT_INC(icp6s_outhist[ND_REDIRECT]); 2708 2709 return; 2710 2711 fail: 2712 if (m) 2713 m_freem(m); 2714 if (m0) 2715 m_freem(m0); 2716 } 2717 2718 /* 2719 * ICMPv6 socket option processing. 2720 */ 2721 int 2722 icmp6_ctloutput(struct socket *so, struct sockopt *sopt) 2723 { 2724 int error = 0; 2725 int optlen; 2726 struct inpcb *inp = sotoinpcb(so); 2727 int level, op, optname; 2728 2729 if (sopt) { 2730 level = sopt->sopt_level; 2731 op = sopt->sopt_dir; 2732 optname = sopt->sopt_name; 2733 optlen = sopt->sopt_valsize; 2734 } else 2735 level = op = optname = optlen = 0; 2736 2737 if (level != IPPROTO_ICMPV6) { 2738 return EINVAL; 2739 } 2740 2741 switch (op) { 2742 case PRCO_SETOPT: 2743 switch (optname) { 2744 case ICMP6_FILTER: 2745 { 2746 struct icmp6_filter ic6f; 2747 2748 if (optlen != sizeof(ic6f)) { 2749 error = EMSGSIZE; 2750 break; 2751 } 2752 error = sooptcopyin(sopt, &ic6f, optlen, optlen); 2753 if (error == 0) { 2754 INP_WLOCK(inp); 2755 *inp->in6p_icmp6filt = ic6f; 2756 INP_WUNLOCK(inp); 2757 } 2758 break; 2759 } 2760 2761 default: 2762 error = ENOPROTOOPT; 2763 break; 2764 } 2765 break; 2766 2767 case PRCO_GETOPT: 2768 switch (optname) { 2769 case ICMP6_FILTER: 2770 { 2771 struct icmp6_filter ic6f; 2772 2773 INP_RLOCK(inp); 2774 ic6f = *inp->in6p_icmp6filt; 2775 INP_RUNLOCK(inp); 2776 error = sooptcopyout(sopt, &ic6f, sizeof(ic6f)); 2777 break; 2778 } 2779 2780 default: 2781 error = ENOPROTOOPT; 2782 break; 2783 } 2784 break; 2785 } 2786 2787 return (error); 2788 } 2789 2790 /* 2791 * Perform rate limit check. 2792 * Returns 0 if it is okay to send the icmp6 packet. 2793 * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate 2794 * limitation. 2795 * 2796 * XXX per-destination/type check necessary? 2797 * 2798 * dst - not used at this moment 2799 * type - not used at this moment 2800 * code - not used at this moment 2801 */ 2802 static int 2803 icmp6_ratelimit(const struct in6_addr *dst, const int type, 2804 const int code) 2805 { 2806 int ret; 2807 2808 ret = 0; /* okay to send */ 2809 2810 /* PPS limit */ 2811 if (!ppsratecheck(&V_icmp6errppslim_last, &V_icmp6errpps_count, 2812 V_icmp6errppslim)) { 2813 /* The packet is subject to rate limit */ 2814 ret++; 2815 } 2816 2817 return ret; 2818 } 2819