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/route/route_ctl.h> 97 #include <net/route/nhop.h> 98 #include <net/vnet.h> 99 100 #include <netinet/in.h> 101 #include <netinet/in_pcb.h> 102 #include <netinet/in_var.h> 103 #include <netinet/ip6.h> 104 #include <netinet/icmp6.h> 105 #include <netinet/tcp_var.h> 106 107 #include <netinet6/in6_fib.h> 108 #include <netinet6/in6_ifattach.h> 109 #include <netinet6/in6_pcb.h> 110 #include <netinet6/ip6_var.h> 111 #include <netinet6/scope6_var.h> 112 #include <netinet6/mld6_var.h> 113 #include <netinet6/nd6.h> 114 #include <netinet6/send.h> 115 116 extern ip6proto_ctlinput_t *ip6_ctlprotox[]; 117 118 VNET_PCPUSTAT_DEFINE(struct icmp6stat, icmp6stat); 119 VNET_PCPUSTAT_SYSINIT(icmp6stat); 120 121 #ifdef VIMAGE 122 VNET_PCPUSTAT_SYSUNINIT(icmp6stat); 123 #endif /* VIMAGE */ 124 125 VNET_DECLARE(struct inpcbinfo, ripcbinfo); 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_icmp6errppslim VNET(icmp6errppslim) 133 #define V_icmp6errpps_count VNET(icmp6errpps_count) 134 #define V_icmp6errppslim_last VNET(icmp6errppslim_last) 135 #define V_icmp6_nodeinfo VNET(icmp6_nodeinfo) 136 137 static void icmp6_errcount(int, int); 138 static int icmp6_rip6_input(struct mbuf **, int); 139 static void icmp6_reflect(struct mbuf *, size_t); 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); 151 152 /* 153 * Kernel module interface for updating icmp6stat. The argument is an index 154 * into icmp6stat treated as an array of u_quad_t. While this encodes the 155 * general layout of icmp6stat into the caller, it doesn't encode its 156 * location, so that future changes to add, for example, per-CPU stats 157 * support won't cause binary compatibility problems for kernel modules. 158 */ 159 void 160 kmod_icmp6stat_inc(int statnum) 161 { 162 163 counter_u64_add(VNET(icmp6stat)[statnum], 1); 164 } 165 166 static void 167 icmp6_errcount(int type, int code) 168 { 169 switch (type) { 170 case ICMP6_DST_UNREACH: 171 switch (code) { 172 case ICMP6_DST_UNREACH_NOROUTE: 173 ICMP6STAT_INC(icp6s_odst_unreach_noroute); 174 return; 175 case ICMP6_DST_UNREACH_ADMIN: 176 ICMP6STAT_INC(icp6s_odst_unreach_admin); 177 return; 178 case ICMP6_DST_UNREACH_BEYONDSCOPE: 179 ICMP6STAT_INC(icp6s_odst_unreach_beyondscope); 180 return; 181 case ICMP6_DST_UNREACH_ADDR: 182 ICMP6STAT_INC(icp6s_odst_unreach_addr); 183 return; 184 case ICMP6_DST_UNREACH_NOPORT: 185 ICMP6STAT_INC(icp6s_odst_unreach_noport); 186 return; 187 } 188 break; 189 case ICMP6_PACKET_TOO_BIG: 190 ICMP6STAT_INC(icp6s_opacket_too_big); 191 return; 192 case ICMP6_TIME_EXCEEDED: 193 switch (code) { 194 case ICMP6_TIME_EXCEED_TRANSIT: 195 ICMP6STAT_INC(icp6s_otime_exceed_transit); 196 return; 197 case ICMP6_TIME_EXCEED_REASSEMBLY: 198 ICMP6STAT_INC(icp6s_otime_exceed_reassembly); 199 return; 200 } 201 break; 202 case ICMP6_PARAM_PROB: 203 switch (code) { 204 case ICMP6_PARAMPROB_HEADER: 205 ICMP6STAT_INC(icp6s_oparamprob_header); 206 return; 207 case ICMP6_PARAMPROB_NEXTHEADER: 208 ICMP6STAT_INC(icp6s_oparamprob_nextheader); 209 return; 210 case ICMP6_PARAMPROB_OPTION: 211 ICMP6STAT_INC(icp6s_oparamprob_option); 212 return; 213 } 214 break; 215 case ND_REDIRECT: 216 ICMP6STAT_INC(icp6s_oredirect); 217 return; 218 } 219 ICMP6STAT_INC(icp6s_ounknown); 220 } 221 222 /* 223 * A wrapper function for icmp6_error() necessary when the erroneous packet 224 * may not contain enough scope zone information. 225 */ 226 void 227 icmp6_error2(struct mbuf *m, int type, int code, int param, 228 struct ifnet *ifp) 229 { 230 struct ip6_hdr *ip6; 231 232 if (ifp == NULL) 233 return; 234 235 if (m->m_len < sizeof(struct ip6_hdr)) { 236 m = m_pullup(m, sizeof(struct ip6_hdr)); 237 if (m == NULL) { 238 IP6STAT_INC(ip6s_exthdrtoolong); 239 return; 240 } 241 } 242 ip6 = mtod(m, struct ip6_hdr *); 243 244 if (in6_setscope(&ip6->ip6_src, ifp, NULL) != 0) 245 return; 246 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0) 247 return; 248 249 icmp6_error(m, type, code, param); 250 } 251 252 /* 253 * Generate an error packet of type error in response to bad IP6 packet. 254 */ 255 void 256 icmp6_error(struct mbuf *m, int type, int code, int param) 257 { 258 struct ip6_hdr *oip6, *nip6; 259 struct icmp6_hdr *icmp6; 260 struct epoch_tracker et; 261 u_int preplen; 262 int off; 263 int nxt; 264 265 ICMP6STAT_INC(icp6s_error); 266 267 /* count per-type-code statistics */ 268 icmp6_errcount(type, code); 269 270 #ifdef M_DECRYPTED /*not openbsd*/ 271 if (m->m_flags & M_DECRYPTED) { 272 ICMP6STAT_INC(icp6s_canterror); 273 goto freeit; 274 } 275 #endif 276 277 if (m->m_len < sizeof(struct ip6_hdr)) { 278 m = m_pullup(m, sizeof(struct ip6_hdr)); 279 if (m == NULL) { 280 IP6STAT_INC(ip6s_exthdrtoolong); 281 return; 282 } 283 } 284 oip6 = mtod(m, struct ip6_hdr *); 285 286 /* 287 * If the destination address of the erroneous packet is a multicast 288 * address, or the packet was sent using link-layer multicast, 289 * we should basically suppress sending an error (RFC 2463, Section 290 * 2.4). 291 * We have two exceptions (the item e.2 in that section): 292 * - the Packet Too Big message can be sent for path MTU discovery. 293 * - the Parameter Problem Message that can be allowed an icmp6 error 294 * in the option type field. This check has been done in 295 * ip6_unknown_opt(), so we can just check the type and code. 296 */ 297 if ((m->m_flags & (M_BCAST|M_MCAST) || 298 IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) && 299 (type != ICMP6_PACKET_TOO_BIG && 300 (type != ICMP6_PARAM_PROB || 301 code != ICMP6_PARAMPROB_OPTION))) 302 goto freeit; 303 304 /* 305 * RFC 2463, 2.4 (e.5): source address check. 306 * XXX: the case of anycast source? 307 */ 308 if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) || 309 IN6_IS_ADDR_MULTICAST(&oip6->ip6_src)) 310 goto freeit; 311 312 /* 313 * If we are about to send ICMPv6 against ICMPv6 error/redirect, 314 * don't do it. 315 */ 316 nxt = -1; 317 off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt); 318 if (off >= 0 && nxt == IPPROTO_ICMPV6) { 319 struct icmp6_hdr *icp; 320 321 if (m->m_len < off + sizeof(struct icmp6_hdr)) { 322 m = m_pullup(m, off + sizeof(struct icmp6_hdr)); 323 if (m == NULL) { 324 IP6STAT_INC(ip6s_exthdrtoolong); 325 return; 326 } 327 } 328 oip6 = mtod(m, struct ip6_hdr *); 329 icp = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 330 331 if (icp->icmp6_type < ICMP6_ECHO_REQUEST || 332 icp->icmp6_type == ND_REDIRECT) { 333 /* 334 * ICMPv6 error 335 * Special case: for redirect (which is 336 * informational) we must not send icmp6 error. 337 */ 338 ICMP6STAT_INC(icp6s_canterror); 339 goto freeit; 340 } else { 341 /* ICMPv6 informational - send the error */ 342 } 343 } else { 344 /* non-ICMPv6 - send the error */ 345 } 346 347 /* Finally, do rate limitation check. */ 348 if (icmp6_ratelimit(&oip6->ip6_src, type, code)) { 349 ICMP6STAT_INC(icp6s_toofreq); 350 goto freeit; 351 } 352 353 /* 354 * OK, ICMP6 can be generated. 355 */ 356 357 if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN) 358 m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len); 359 360 preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 361 M_PREPEND(m, preplen, M_NOWAIT); /* FIB is also copied over. */ 362 if (m == NULL) { 363 nd6log((LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__)); 364 return; 365 } 366 367 nip6 = mtod(m, struct ip6_hdr *); 368 nip6->ip6_src = oip6->ip6_src; 369 nip6->ip6_dst = oip6->ip6_dst; 370 371 in6_clearscope(&oip6->ip6_src); 372 in6_clearscope(&oip6->ip6_dst); 373 374 icmp6 = (struct icmp6_hdr *)(nip6 + 1); 375 icmp6->icmp6_type = type; 376 icmp6->icmp6_code = code; 377 icmp6->icmp6_pptr = htonl((u_int32_t)param); 378 379 ICMP6STAT_INC(icp6s_outhist[type]); 380 NET_EPOCH_ENTER(et); 381 icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */ 382 NET_EPOCH_EXIT(et); 383 384 return; 385 386 freeit: 387 /* 388 * If we can't tell whether or not we can generate ICMP6, free it. 389 */ 390 m_freem(m); 391 } 392 393 int 394 icmp6_errmap(const struct icmp6_hdr *icmp6) 395 { 396 397 switch (icmp6->icmp6_type) { 398 case ICMP6_DST_UNREACH: 399 switch (icmp6->icmp6_code) { 400 case ICMP6_DST_UNREACH_NOROUTE: 401 case ICMP6_DST_UNREACH_ADDR: 402 return (EHOSTUNREACH); 403 case ICMP6_DST_UNREACH_NOPORT: 404 case ICMP6_DST_UNREACH_ADMIN: 405 return (ECONNREFUSED); 406 case ICMP6_DST_UNREACH_BEYONDSCOPE: 407 return (ENOPROTOOPT); 408 default: 409 return (0); /* Shouldn't happen. */ 410 } 411 case ICMP6_PACKET_TOO_BIG: 412 return (EMSGSIZE); 413 case ICMP6_TIME_EXCEEDED: 414 switch (icmp6->icmp6_code) { 415 case ICMP6_TIME_EXCEED_TRANSIT: 416 return (EHOSTUNREACH); 417 case ICMP6_TIME_EXCEED_REASSEMBLY: 418 return (0); 419 default: 420 return (0); /* Shouldn't happen. */ 421 } 422 case ICMP6_PARAM_PROB: 423 switch (icmp6->icmp6_code) { 424 case ICMP6_PARAMPROB_NEXTHEADER: 425 return (ECONNREFUSED); 426 case ICMP6_PARAMPROB_HEADER: 427 case ICMP6_PARAMPROB_OPTION: 428 return (ENOPROTOOPT); 429 default: 430 return (0); /* Shouldn't happen. */ 431 } 432 default: 433 return (0); 434 } 435 } 436 437 /* 438 * Process a received ICMP6 message. 439 */ 440 int 441 icmp6_input(struct mbuf **mp, int *offp, int proto) 442 { 443 struct mbuf *m, *n; 444 struct ifnet *ifp; 445 struct ip6_hdr *ip6, *nip6; 446 struct icmp6_hdr *icmp6, *nicmp6; 447 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 448 int code, error, icmp6len, ip6len, noff, off, sum; 449 450 NET_EPOCH_ASSERT(); 451 452 m = *mp; 453 off = *offp; 454 455 if (m->m_len < off + sizeof(struct icmp6_hdr)) { 456 m = m_pullup(m, off + sizeof(struct icmp6_hdr)); 457 if (m == NULL) { 458 IP6STAT_INC(ip6s_exthdrtoolong); 459 *mp = m; 460 return (IPPROTO_DONE); 461 } 462 } 463 464 /* 465 * Locate icmp6 structure in mbuf, and check 466 * that not corrupted and of at least minimum length 467 */ 468 469 icmp6len = m->m_pkthdr.len - off; 470 if (icmp6len < sizeof(struct icmp6_hdr)) { 471 ICMP6STAT_INC(icp6s_tooshort); 472 goto freeit; 473 } 474 475 ip6 = mtod(m, struct ip6_hdr *); 476 ifp = m->m_pkthdr.rcvif; 477 /* 478 * Check multicast group membership. 479 * Note: SSM filters are not applied for ICMPv6 traffic. 480 */ 481 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 482 struct in6_multi *inm; 483 484 inm = in6m_lookup(ifp, &ip6->ip6_dst); 485 if (inm == NULL) { 486 IP6STAT_INC(ip6s_notmember); 487 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 488 goto freeit; 489 } 490 } 491 492 /* Calculate the checksum. */ 493 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off); 494 code = icmp6->icmp6_code; 495 if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) { 496 nd6log((LOG_ERR, 497 "ICMP6 checksum error(%d|%x) %s\n", 498 icmp6->icmp6_type, sum, 499 ip6_sprintf(ip6bufs, &ip6->ip6_src))); 500 ICMP6STAT_INC(icp6s_checksum); 501 goto freeit; 502 } 503 504 ICMP6STAT_INC(icp6s_inhist[icmp6->icmp6_type]); 505 icmp6_ifstat_inc(ifp, ifs6_in_msg); 506 if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK) 507 icmp6_ifstat_inc(ifp, ifs6_in_error); 508 509 ip6len = sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen); 510 switch (icmp6->icmp6_type) { 511 case ICMP6_DST_UNREACH: 512 icmp6_ifstat_inc(ifp, ifs6_in_dstunreach); 513 switch (code) { 514 case ICMP6_DST_UNREACH_ADMIN: 515 icmp6_ifstat_inc(ifp, ifs6_in_adminprohib); 516 case ICMP6_DST_UNREACH_NOROUTE: 517 case ICMP6_DST_UNREACH_ADDR: 518 case ICMP6_DST_UNREACH_BEYONDSCOPE: 519 case ICMP6_DST_UNREACH_NOPORT: 520 goto deliver; 521 default: 522 goto badcode; 523 } 524 case ICMP6_PACKET_TOO_BIG: 525 icmp6_ifstat_inc(ifp, ifs6_in_pkttoobig); 526 /* 527 * Validation is made in icmp6_mtudisc_update. 528 * Updating the path MTU will be done after examining 529 * intermediate extension headers. 530 */ 531 goto deliver; 532 case ICMP6_TIME_EXCEEDED: 533 icmp6_ifstat_inc(ifp, ifs6_in_timeexceed); 534 switch (code) { 535 case ICMP6_TIME_EXCEED_TRANSIT: 536 case ICMP6_TIME_EXCEED_REASSEMBLY: 537 goto deliver; 538 default: 539 goto badcode; 540 } 541 case ICMP6_PARAM_PROB: 542 icmp6_ifstat_inc(ifp, ifs6_in_paramprob); 543 switch (code) { 544 case ICMP6_PARAMPROB_NEXTHEADER: 545 case ICMP6_PARAMPROB_HEADER: 546 case ICMP6_PARAMPROB_OPTION: 547 goto deliver; 548 default: 549 goto badcode; 550 } 551 case ICMP6_ECHO_REQUEST: 552 icmp6_ifstat_inc(ifp, ifs6_in_echo); 553 if (code != 0) 554 goto badcode; 555 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) { 556 /* Give up remote */ 557 break; 558 } 559 if (!M_WRITABLE(n) 560 || n->m_len < off + sizeof(struct icmp6_hdr)) { 561 struct mbuf *n0 = n; 562 int n0len; 563 564 CTASSERT(sizeof(*nip6) + sizeof(*nicmp6) <= MHLEN); 565 n = m_gethdr(M_NOWAIT, n0->m_type); 566 if (n == NULL) { 567 /* Give up remote */ 568 m_freem(n0); 569 break; 570 } 571 572 m_move_pkthdr(n, n0); /* FIB copied. */ 573 n0len = n0->m_pkthdr.len; /* save for use below */ 574 /* 575 * Copy IPv6 and ICMPv6 only. 576 */ 577 nip6 = mtod(n, struct ip6_hdr *); 578 bcopy(ip6, nip6, sizeof(struct ip6_hdr)); 579 nicmp6 = (struct icmp6_hdr *)(nip6 + 1); 580 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr)); 581 noff = sizeof(struct ip6_hdr); 582 /* new mbuf contains only ipv6+icmpv6 headers */ 583 n->m_len = noff + sizeof(struct icmp6_hdr); 584 /* 585 * Adjust mbuf. ip6_plen will be adjusted in 586 * ip6_output(). 587 */ 588 m_adj(n0, off + sizeof(struct icmp6_hdr)); 589 /* recalculate complete packet size */ 590 n->m_pkthdr.len = n0len + (noff - off); 591 n->m_next = n0; 592 } else { 593 if (n->m_len < off + sizeof(*nicmp6)) { 594 n = m_pullup(n, off + sizeof(*nicmp6)); 595 if (n == NULL) { 596 IP6STAT_INC(ip6s_exthdrtoolong); 597 break; 598 } 599 } 600 nicmp6 = (struct icmp6_hdr *)(mtod(n, caddr_t) + off); 601 noff = off; 602 } 603 if (n) { 604 nicmp6->icmp6_type = ICMP6_ECHO_REPLY; 605 nicmp6->icmp6_code = 0; 606 ICMP6STAT_INC(icp6s_reflect); 607 ICMP6STAT_INC(icp6s_outhist[ICMP6_ECHO_REPLY]); 608 icmp6_reflect(n, noff); 609 } 610 break; 611 612 case ICMP6_ECHO_REPLY: 613 icmp6_ifstat_inc(ifp, ifs6_in_echoreply); 614 if (code != 0) 615 goto badcode; 616 break; 617 618 case MLD_LISTENER_QUERY: 619 case MLD_LISTENER_REPORT: 620 case MLD_LISTENER_DONE: 621 case MLDV2_LISTENER_REPORT: 622 /* 623 * Drop MLD traffic which is not link-local, has a hop limit 624 * of greater than 1 hop, or which does not have the 625 * IPv6 HBH Router Alert option. 626 * As IPv6 HBH options are stripped in ip6_input() we must 627 * check an mbuf header flag. 628 * XXX Should we also sanity check that these messages 629 * were directed to a link-local multicast prefix? 630 */ 631 if ((ip6->ip6_hlim != 1) || (m->m_flags & M_RTALERT_MLD) == 0) 632 goto freeit; 633 if (mld_input(&m, off, icmp6len) != 0) { 634 *mp = NULL; 635 return (IPPROTO_DONE); 636 } 637 /* m stays. */ 638 break; 639 640 case ICMP6_WRUREQUEST: /* ICMP6_FQDN_QUERY */ 641 { 642 enum { WRU, FQDN } mode; 643 struct prison *pr; 644 645 if (!V_icmp6_nodeinfo) 646 break; 647 648 if (icmp6len == sizeof(struct icmp6_hdr) + 4) 649 mode = WRU; 650 else if (icmp6len >= sizeof(struct icmp6_nodeinfo)) 651 mode = FQDN; 652 else 653 goto badlen; 654 655 pr = NULL; 656 sx_slock(&allprison_lock); 657 TAILQ_FOREACH(pr, &allprison, pr_list) 658 if (pr->pr_vnet == ifp->if_vnet) 659 break; 660 sx_sunlock(&allprison_lock); 661 if (pr == NULL) 662 pr = curthread->td_ucred->cr_prison; 663 if (mode == FQDN) { 664 if (m->m_len < off + sizeof(struct icmp6_nodeinfo)) { 665 m = m_pullup(m, off + 666 sizeof(struct icmp6_nodeinfo)); 667 if (m == NULL) { 668 IP6STAT_INC(ip6s_exthdrtoolong); 669 *mp = m; 670 return (IPPROTO_DONE); 671 } 672 } 673 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 674 if (n) 675 n = ni6_input(n, off, pr); 676 /* XXX meaningless if n == NULL */ 677 noff = sizeof(struct ip6_hdr); 678 } else { 679 u_char *p; 680 int maxhlen, hlen; 681 682 /* 683 * XXX: this combination of flags is pointless, 684 * but should we keep this for compatibility? 685 */ 686 if ((V_icmp6_nodeinfo & (ICMP6_NODEINFO_FQDNOK | 687 ICMP6_NODEINFO_TMPADDROK)) != 688 (ICMP6_NODEINFO_FQDNOK | ICMP6_NODEINFO_TMPADDROK)) 689 break; 690 691 if (code != 0) 692 goto badcode; 693 694 CTASSERT(sizeof(*nip6) + sizeof(*nicmp6) + 4 <= MHLEN); 695 n = m_gethdr(M_NOWAIT, m->m_type); 696 if (n == NULL) { 697 /* Give up remote */ 698 break; 699 } 700 if (!m_dup_pkthdr(n, m, M_NOWAIT)) { 701 /* 702 * Previous code did a blind M_COPY_PKTHDR 703 * and said "just for rcvif". If true, then 704 * we could tolerate the dup failing (due to 705 * the deep copy of the tag chain). For now 706 * be conservative and just fail. 707 */ 708 m_free(n); 709 n = NULL; 710 break; 711 } 712 /* 713 * Copy IPv6 and ICMPv6 only. 714 */ 715 nip6 = mtod(n, struct ip6_hdr *); 716 bcopy(ip6, nip6, sizeof(struct ip6_hdr)); 717 nicmp6 = (struct icmp6_hdr *)(nip6 + 1); 718 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr)); 719 p = (u_char *)(nicmp6 + 1); 720 bzero(p, 4); 721 722 maxhlen = M_TRAILINGSPACE(n) - 723 (sizeof(*nip6) + sizeof(*nicmp6) + 4); 724 mtx_lock(&pr->pr_mtx); 725 hlen = strlen(pr->pr_hostname); 726 if (maxhlen > hlen) 727 maxhlen = hlen; 728 /* meaningless TTL */ 729 bcopy(pr->pr_hostname, p + 4, maxhlen); 730 mtx_unlock(&pr->pr_mtx); 731 noff = sizeof(struct ip6_hdr); 732 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + 733 sizeof(struct icmp6_hdr) + 4 + maxhlen; 734 nicmp6->icmp6_type = ICMP6_WRUREPLY; 735 nicmp6->icmp6_code = 0; 736 } 737 if (n) { 738 ICMP6STAT_INC(icp6s_reflect); 739 ICMP6STAT_INC(icp6s_outhist[ICMP6_WRUREPLY]); 740 icmp6_reflect(n, noff); 741 } 742 break; 743 } 744 745 case ICMP6_WRUREPLY: 746 if (code != 0) 747 goto badcode; 748 break; 749 750 case ND_ROUTER_SOLICIT: 751 icmp6_ifstat_inc(ifp, ifs6_in_routersolicit); 752 if (code != 0) 753 goto badcode; 754 if (icmp6len < sizeof(struct nd_router_solicit)) 755 goto badlen; 756 if (send_sendso_input_hook != NULL) { 757 if (m->m_len < off + icmp6len) { 758 m = m_pullup(m, off + icmp6len); 759 if (m == NULL) { 760 IP6STAT_INC(ip6s_exthdrtoolong); 761 *mp = NULL; 762 return (IPPROTO_DONE); 763 } 764 } 765 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 766 if (error == 0) { 767 m = NULL; 768 goto freeit; 769 } 770 } 771 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 772 nd6_rs_input(m, off, icmp6len); 773 m = n; 774 if (m == NULL) 775 goto freeit; 776 break; 777 778 case ND_ROUTER_ADVERT: 779 icmp6_ifstat_inc(ifp, ifs6_in_routeradvert); 780 if (code != 0) 781 goto badcode; 782 if (icmp6len < sizeof(struct nd_router_advert)) 783 goto badlen; 784 if (send_sendso_input_hook != NULL) { 785 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 786 if (error == 0) { 787 m = NULL; 788 goto freeit; 789 } 790 } 791 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 792 nd6_ra_input(m, off, icmp6len); 793 m = n; 794 if (m == NULL) 795 goto freeit; 796 break; 797 798 case ND_NEIGHBOR_SOLICIT: 799 icmp6_ifstat_inc(ifp, ifs6_in_neighborsolicit); 800 if (code != 0) 801 goto badcode; 802 if (icmp6len < sizeof(struct nd_neighbor_solicit)) 803 goto badlen; 804 if (send_sendso_input_hook != NULL) { 805 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 806 if (error == 0) { 807 m = NULL; 808 goto freeit; 809 } 810 } 811 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 812 nd6_ns_input(m, off, icmp6len); 813 m = n; 814 if (m == NULL) 815 goto freeit; 816 break; 817 818 case ND_NEIGHBOR_ADVERT: 819 icmp6_ifstat_inc(ifp, ifs6_in_neighboradvert); 820 if (code != 0) 821 goto badcode; 822 if (icmp6len < sizeof(struct nd_neighbor_advert)) 823 goto badlen; 824 if (send_sendso_input_hook != NULL) { 825 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 826 if (error == 0) { 827 m = NULL; 828 goto freeit; 829 } 830 } 831 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 832 nd6_na_input(m, off, icmp6len); 833 m = n; 834 if (m == NULL) 835 goto freeit; 836 break; 837 838 case ND_REDIRECT: 839 icmp6_ifstat_inc(ifp, ifs6_in_redirect); 840 if (code != 0) 841 goto badcode; 842 if (icmp6len < sizeof(struct nd_redirect)) 843 goto badlen; 844 if (send_sendso_input_hook != NULL) { 845 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 846 if (error == 0) { 847 m = NULL; 848 goto freeit; 849 } 850 } 851 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 852 icmp6_redirect_input(m, off); 853 m = n; 854 if (m == NULL) 855 goto freeit; 856 break; 857 858 case ICMP6_ROUTER_RENUMBERING: 859 if (code != ICMP6_ROUTER_RENUMBERING_COMMAND && 860 code != ICMP6_ROUTER_RENUMBERING_RESULT) 861 goto badcode; 862 if (icmp6len < sizeof(struct icmp6_router_renum)) 863 goto badlen; 864 break; 865 866 default: 867 nd6log((LOG_DEBUG, 868 "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n", 869 icmp6->icmp6_type, ip6_sprintf(ip6bufs, &ip6->ip6_src), 870 ip6_sprintf(ip6bufd, &ip6->ip6_dst), 871 ifp ? ifp->if_index : 0)); 872 if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) { 873 /* ICMPv6 error: MUST deliver it by spec... */ 874 goto deliver; 875 } else { 876 /* ICMPv6 informational: MUST not deliver */ 877 break; 878 } 879 deliver: 880 if (icmp6_notify_error(&m, off, icmp6len) != 0) { 881 /* In this case, m should've been freed. */ 882 *mp = NULL; 883 return (IPPROTO_DONE); 884 } 885 break; 886 887 badcode: 888 ICMP6STAT_INC(icp6s_badcode); 889 break; 890 891 badlen: 892 ICMP6STAT_INC(icp6s_badlen); 893 break; 894 } 895 896 /* deliver the packet to appropriate sockets */ 897 icmp6_rip6_input(&m, *offp); 898 899 *mp = m; 900 return (IPPROTO_DONE); 901 902 freeit: 903 m_freem(m); 904 *mp = NULL; 905 return (IPPROTO_DONE); 906 } 907 908 static int 909 icmp6_notify_error(struct mbuf **mp, int off, int icmp6len) 910 { 911 struct mbuf *m; 912 struct icmp6_hdr *icmp6; 913 struct ip6_hdr *eip6; 914 u_int32_t notifymtu; 915 struct sockaddr_in6 icmp6src, icmp6dst; 916 917 m = *mp; 918 919 if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) { 920 ICMP6STAT_INC(icp6s_tooshort); 921 goto freeit; 922 } 923 924 if (m->m_len < off + sizeof(*icmp6) + sizeof(struct ip6_hdr)) { 925 m = m_pullup(m, off + sizeof(*icmp6) + sizeof(struct ip6_hdr)); 926 if (m == NULL) { 927 IP6STAT_INC(ip6s_exthdrtoolong); 928 *mp = m; 929 return (-1); 930 } 931 } 932 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 933 eip6 = (struct ip6_hdr *)(icmp6 + 1); 934 bzero(&icmp6dst, sizeof(icmp6dst)); 935 936 /* Detect the upper level protocol */ 937 { 938 u_int8_t nxt = eip6->ip6_nxt; 939 int eoff = off + sizeof(struct icmp6_hdr) + 940 sizeof(struct ip6_hdr); 941 struct ip6ctlparam ip6cp; 942 int icmp6type = icmp6->icmp6_type; 943 struct ip6_frag *fh; 944 struct ip6_rthdr *rth; 945 struct ip6_rthdr0 *rth0; 946 int rthlen; 947 948 while (1) { /* XXX: should avoid infinite loop explicitly? */ 949 struct ip6_ext *eh; 950 951 switch (nxt) { 952 case IPPROTO_HOPOPTS: 953 case IPPROTO_DSTOPTS: 954 case IPPROTO_AH: 955 if (m->m_len < eoff + sizeof(struct ip6_ext)) { 956 m = m_pullup(m, eoff + 957 sizeof(struct ip6_ext)); 958 if (m == NULL) { 959 IP6STAT_INC(ip6s_exthdrtoolong); 960 *mp = m; 961 return (-1); 962 } 963 } 964 eh = (struct ip6_ext *) 965 (mtod(m, caddr_t) + eoff); 966 if (nxt == IPPROTO_AH) 967 eoff += (eh->ip6e_len + 2) << 2; 968 else 969 eoff += (eh->ip6e_len + 1) << 3; 970 nxt = eh->ip6e_nxt; 971 break; 972 case IPPROTO_ROUTING: 973 /* 974 * When the erroneous packet contains a 975 * routing header, we should examine the 976 * header to determine the final destination. 977 * Otherwise, we can't properly update 978 * information that depends on the final 979 * destination (e.g. path MTU). 980 */ 981 if (m->m_len < eoff + sizeof(*rth)) { 982 m = m_pullup(m, eoff + sizeof(*rth)); 983 if (m == NULL) { 984 IP6STAT_INC(ip6s_exthdrtoolong); 985 *mp = m; 986 return (-1); 987 } 988 } 989 rth = (struct ip6_rthdr *) 990 (mtod(m, caddr_t) + eoff); 991 rthlen = (rth->ip6r_len + 1) << 3; 992 /* 993 * XXX: currently there is no 994 * officially defined type other 995 * than type-0. 996 * Note that if the segment left field 997 * is 0, all intermediate hops must 998 * have been passed. 999 */ 1000 if (rth->ip6r_segleft && 1001 rth->ip6r_type == IPV6_RTHDR_TYPE_0) { 1002 int hops; 1003 1004 if (m->m_len < eoff + rthlen) { 1005 m = m_pullup(m, eoff + rthlen); 1006 if (m == NULL) { 1007 IP6STAT_INC( 1008 ip6s_exthdrtoolong); 1009 *mp = m; 1010 return (-1); 1011 } 1012 } 1013 rth0 = (struct ip6_rthdr0 *) 1014 (mtod(m, caddr_t) + eoff); 1015 1016 /* just ignore a bogus header */ 1017 if ((rth0->ip6r0_len % 2) == 0 && 1018 (hops = rth0->ip6r0_len/2)) 1019 icmp6dst.sin6_addr = *((struct in6_addr *)(rth0 + 1) + (hops - 1)); 1020 } 1021 eoff += rthlen; 1022 nxt = rth->ip6r_nxt; 1023 break; 1024 case IPPROTO_FRAGMENT: 1025 if (m->m_len < eoff + sizeof(struct ip6_frag)) { 1026 m = m_pullup(m, eoff + 1027 sizeof(struct ip6_frag)); 1028 if (m == NULL) { 1029 IP6STAT_INC(ip6s_exthdrtoolong); 1030 *mp = m; 1031 return (-1); 1032 } 1033 } 1034 fh = (struct ip6_frag *)(mtod(m, caddr_t) + 1035 eoff); 1036 /* 1037 * Data after a fragment header is meaningless 1038 * unless it is the first fragment, but 1039 * we'll go to the notify label for path MTU 1040 * discovery. 1041 */ 1042 if (fh->ip6f_offlg & IP6F_OFF_MASK) 1043 goto notify; 1044 1045 eoff += sizeof(struct ip6_frag); 1046 nxt = fh->ip6f_nxt; 1047 break; 1048 default: 1049 /* 1050 * This case includes ESP and the No Next 1051 * Header. In such cases going to the notify 1052 * label does not have any meaning 1053 * (i.e. ctlfunc will be NULL), but we go 1054 * anyway since we might have to update 1055 * path MTU information. 1056 */ 1057 goto notify; 1058 } 1059 } 1060 notify: 1061 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 1062 1063 /* 1064 * retrieve parameters from the inner IPv6 header, and convert 1065 * them into sockaddr structures. 1066 * XXX: there is no guarantee that the source or destination 1067 * addresses of the inner packet are in the same scope as 1068 * the addresses of the icmp packet. But there is no other 1069 * way to determine the zone. 1070 */ 1071 eip6 = (struct ip6_hdr *)(icmp6 + 1); 1072 1073 icmp6dst.sin6_len = sizeof(struct sockaddr_in6); 1074 icmp6dst.sin6_family = AF_INET6; 1075 if (IN6_IS_ADDR_UNSPECIFIED(&icmp6dst.sin6_addr)) 1076 icmp6dst.sin6_addr = eip6->ip6_dst; 1077 if (in6_setscope(&icmp6dst.sin6_addr, m->m_pkthdr.rcvif, NULL)) 1078 goto freeit; 1079 bzero(&icmp6src, sizeof(icmp6src)); 1080 icmp6src.sin6_len = sizeof(struct sockaddr_in6); 1081 icmp6src.sin6_family = AF_INET6; 1082 icmp6src.sin6_addr = eip6->ip6_src; 1083 if (in6_setscope(&icmp6src.sin6_addr, m->m_pkthdr.rcvif, NULL)) 1084 goto freeit; 1085 icmp6src.sin6_flowinfo = 1086 (eip6->ip6_flow & IPV6_FLOWLABEL_MASK); 1087 1088 ip6cp.ip6c_m = m; 1089 ip6cp.ip6c_icmp6 = icmp6; 1090 ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1); 1091 ip6cp.ip6c_off = eoff; 1092 ip6cp.ip6c_finaldst = &icmp6dst; 1093 ip6cp.ip6c_src = &icmp6src; 1094 ip6cp.ip6c_nxt = nxt; 1095 1096 if (icmp6type == ICMP6_PACKET_TOO_BIG) { 1097 notifymtu = ntohl(icmp6->icmp6_mtu); 1098 ip6cp.ip6c_cmdarg = (void *)¬ifymtu; 1099 icmp6_mtudisc_update(&ip6cp, 1); /*XXX*/ 1100 } 1101 1102 if (ip6_ctlprotox[nxt] != NULL) 1103 ip6_ctlprotox[nxt](&ip6cp); 1104 } 1105 *mp = m; 1106 return (0); 1107 1108 freeit: 1109 m_freem(m); 1110 *mp = NULL; 1111 return (-1); 1112 } 1113 1114 void 1115 icmp6_mtudisc_update(struct ip6ctlparam *ip6cp, int validated) 1116 { 1117 struct in6_addr *dst = &ip6cp->ip6c_finaldst->sin6_addr; 1118 struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6; 1119 struct mbuf *m = ip6cp->ip6c_m; /* will be necessary for scope issue */ 1120 u_int mtu = ntohl(icmp6->icmp6_mtu); 1121 struct in_conninfo inc; 1122 uint32_t max_mtu; 1123 1124 #if 0 1125 /* 1126 * RFC2460 section 5, last paragraph. 1127 * even though minimum link MTU for IPv6 is IPV6_MMTU, 1128 * we may see ICMPv6 too big with mtu < IPV6_MMTU 1129 * due to packet translator in the middle. 1130 * see ip6_output() and ip6_getpmtu() "alwaysfrag" case for 1131 * special handling. 1132 */ 1133 if (mtu < IPV6_MMTU) 1134 return; 1135 #endif 1136 1137 /* 1138 * we reject ICMPv6 too big with abnormally small value. 1139 * XXX what is the good definition of "abnormally small"? 1140 */ 1141 if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8) 1142 return; 1143 1144 if (!validated) 1145 return; 1146 1147 /* 1148 * In case the suggested mtu is less than IPV6_MMTU, we 1149 * only need to remember that it was for above mentioned 1150 * "alwaysfrag" case. 1151 * Try to be as close to the spec as possible. 1152 */ 1153 if (mtu < IPV6_MMTU) 1154 mtu = IPV6_MMTU - 8; 1155 1156 bzero(&inc, sizeof(inc)); 1157 inc.inc_fibnum = M_GETFIB(m); 1158 inc.inc_flags |= INC_ISIPV6; 1159 inc.inc6_faddr = *dst; 1160 if (in6_setscope(&inc.inc6_faddr, m->m_pkthdr.rcvif, NULL)) 1161 return; 1162 1163 max_mtu = tcp_hc_getmtu(&inc); 1164 if (max_mtu == 0) 1165 max_mtu = tcp_maxmtu6(&inc, NULL); 1166 1167 if (mtu < max_mtu) { 1168 tcp_hc_updatemtu(&inc, mtu); 1169 ICMP6STAT_INC(icp6s_pmtuchg); 1170 } 1171 } 1172 1173 /* 1174 * Process a Node Information Query packet, based on 1175 * draft-ietf-ipngwg-icmp-name-lookups-07. 1176 * 1177 * Spec incompatibilities: 1178 * - IPv6 Subject address handling 1179 * - IPv4 Subject address handling support missing 1180 * - Proxy reply (answer even if it's not for me) 1181 * - joins NI group address at in6_ifattach() time only, does not cope 1182 * with hostname changes by sethostname(3) 1183 */ 1184 static struct mbuf * 1185 ni6_input(struct mbuf *m, int off, struct prison *pr) 1186 { 1187 struct icmp6_nodeinfo *ni6, *nni6; 1188 struct mbuf *n = NULL; 1189 u_int16_t qtype; 1190 int subjlen; 1191 int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); 1192 struct ni_reply_fqdn *fqdn; 1193 int addrs; /* for NI_QTYPE_NODEADDR */ 1194 struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */ 1195 struct in6_addr in6_subj; /* subject address */ 1196 struct ip6_hdr *ip6; 1197 int oldfqdn = 0; /* if 1, return pascal string (03 draft) */ 1198 char *subj = NULL; 1199 struct in6_ifaddr *ia6 = NULL; 1200 1201 ip6 = mtod(m, struct ip6_hdr *); 1202 ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off); 1203 1204 /* 1205 * Validate IPv6 source address. 1206 * The default configuration MUST be to refuse answering queries from 1207 * global-scope addresses according to RFC4602. 1208 * Notes: 1209 * - it's not very clear what "refuse" means; this implementation 1210 * simply drops it. 1211 * - it's not very easy to identify global-scope (unicast) addresses 1212 * since there are many prefixes for them. It should be safer 1213 * and in practice sufficient to check "all" but loopback and 1214 * link-local (note that site-local unicast was deprecated and 1215 * ULA is defined as global scope-wise) 1216 */ 1217 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_GLOBALOK) == 0 && 1218 !IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) && 1219 !IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) 1220 goto bad; 1221 1222 /* 1223 * Validate IPv6 destination address. 1224 * 1225 * The Responder must discard the Query without further processing 1226 * unless it is one of the Responder's unicast or anycast addresses, or 1227 * a link-local scope multicast address which the Responder has joined. 1228 * [RFC4602, Section 5.] 1229 */ 1230 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 1231 if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst)) 1232 goto bad; 1233 /* else it's a link-local multicast, fine */ 1234 } else { /* unicast or anycast */ 1235 ia6 = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */, false); 1236 if (ia6 == NULL) 1237 goto bad; /* XXX impossible */ 1238 1239 if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) && 1240 !(V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK)) { 1241 nd6log((LOG_DEBUG, "ni6_input: ignore node info to " 1242 "a temporary address in %s:%d", 1243 __FILE__, __LINE__)); 1244 goto bad; 1245 } 1246 } 1247 1248 /* validate query Subject field. */ 1249 qtype = ntohs(ni6->ni_qtype); 1250 subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo); 1251 switch (qtype) { 1252 case NI_QTYPE_NOOP: 1253 case NI_QTYPE_SUPTYPES: 1254 /* 07 draft */ 1255 if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0) 1256 break; 1257 /* FALLTHROUGH */ 1258 case NI_QTYPE_FQDN: 1259 case NI_QTYPE_NODEADDR: 1260 case NI_QTYPE_IPV4ADDR: 1261 switch (ni6->ni_code) { 1262 case ICMP6_NI_SUBJ_IPV6: 1263 #if ICMP6_NI_SUBJ_IPV6 != 0 1264 case 0: 1265 #endif 1266 /* 1267 * backward compatibility - try to accept 03 draft 1268 * format, where no Subject is present. 1269 */ 1270 if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 && 1271 subjlen == 0) { 1272 oldfqdn++; 1273 break; 1274 } 1275 #if ICMP6_NI_SUBJ_IPV6 != 0 1276 if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6) 1277 goto bad; 1278 #endif 1279 1280 if (subjlen != sizeof(struct in6_addr)) 1281 goto bad; 1282 1283 /* 1284 * Validate Subject address. 1285 * 1286 * Not sure what exactly "address belongs to the node" 1287 * means in the spec, is it just unicast, or what? 1288 * 1289 * At this moment we consider Subject address as 1290 * "belong to the node" if the Subject address equals 1291 * to the IPv6 destination address; validation for 1292 * IPv6 destination address should have done enough 1293 * check for us. 1294 * 1295 * We do not do proxy at this moment. 1296 */ 1297 m_copydata(m, off + sizeof(struct icmp6_nodeinfo), 1298 subjlen, (caddr_t)&in6_subj); 1299 if (in6_setscope(&in6_subj, m->m_pkthdr.rcvif, NULL)) 1300 goto bad; 1301 1302 subj = (char *)&in6_subj; 1303 if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &in6_subj)) 1304 break; 1305 1306 /* 1307 * XXX if we are to allow other cases, we should really 1308 * be careful about scope here. 1309 * basically, we should disallow queries toward IPv6 1310 * destination X with subject Y, 1311 * if scope(X) > scope(Y). 1312 * if we allow scope(X) > scope(Y), it will result in 1313 * information leakage across scope boundary. 1314 */ 1315 goto bad; 1316 1317 case ICMP6_NI_SUBJ_FQDN: 1318 /* 1319 * Validate Subject name with gethostname(3). 1320 * 1321 * The behavior may need some debate, since: 1322 * - we are not sure if the node has FQDN as 1323 * hostname (returned by gethostname(3)). 1324 * - the code does wildcard match for truncated names. 1325 * however, we are not sure if we want to perform 1326 * wildcard match, if gethostname(3) side has 1327 * truncated hostname. 1328 */ 1329 mtx_lock(&pr->pr_mtx); 1330 n = ni6_nametodns(pr->pr_hostname, 1331 strlen(pr->pr_hostname), 0); 1332 mtx_unlock(&pr->pr_mtx); 1333 if (!n || n->m_next || n->m_len == 0) 1334 goto bad; 1335 if (m->m_len < off + sizeof(struct icmp6_nodeinfo) + 1336 subjlen) { 1337 m = m_pullup(m, off + 1338 sizeof(struct icmp6_nodeinfo) + subjlen); 1339 if (m == NULL) { 1340 IP6STAT_INC(ip6s_exthdrtoolong); 1341 goto bad; 1342 } 1343 } 1344 /* ip6 possibly invalid but not used after. */ 1345 ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off); 1346 subj = (char *)(mtod(m, caddr_t) + off + 1347 sizeof(struct icmp6_nodeinfo)); 1348 if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *), 1349 n->m_len)) { 1350 goto bad; 1351 } 1352 m_freem(n); 1353 n = NULL; 1354 break; 1355 1356 case ICMP6_NI_SUBJ_IPV4: /* XXX: to be implemented? */ 1357 default: 1358 goto bad; 1359 } 1360 break; 1361 } 1362 1363 /* refuse based on configuration. XXX ICMP6_NI_REFUSED? */ 1364 switch (qtype) { 1365 case NI_QTYPE_FQDN: 1366 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_FQDNOK) == 0) 1367 goto bad; 1368 break; 1369 case NI_QTYPE_NODEADDR: 1370 case NI_QTYPE_IPV4ADDR: 1371 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_NODEADDROK) == 0) 1372 goto bad; 1373 break; 1374 } 1375 1376 /* guess reply length */ 1377 switch (qtype) { 1378 case NI_QTYPE_NOOP: 1379 break; /* no reply data */ 1380 case NI_QTYPE_SUPTYPES: 1381 replylen += sizeof(u_int32_t); 1382 break; 1383 case NI_QTYPE_FQDN: 1384 /* XXX will append an mbuf */ 1385 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); 1386 break; 1387 case NI_QTYPE_NODEADDR: 1388 addrs = ni6_addrs(ni6, m, &ifp, (struct in6_addr *)subj); 1389 if ((replylen += addrs * (sizeof(struct in6_addr) + 1390 sizeof(u_int32_t))) > MCLBYTES) 1391 replylen = MCLBYTES; /* XXX: will truncate pkt later */ 1392 break; 1393 case NI_QTYPE_IPV4ADDR: 1394 /* unsupported - should respond with unknown Qtype? */ 1395 break; 1396 default: 1397 /* 1398 * XXX: We must return a reply with the ICMP6 code 1399 * `unknown Qtype' in this case. However we regard the case 1400 * as an FQDN query for backward compatibility. 1401 * Older versions set a random value to this field, 1402 * so it rarely varies in the defined qtypes. 1403 * But the mechanism is not reliable... 1404 * maybe we should obsolete older versions. 1405 */ 1406 qtype = NI_QTYPE_FQDN; 1407 /* XXX will append an mbuf */ 1408 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); 1409 oldfqdn++; 1410 break; 1411 } 1412 1413 /* Allocate an mbuf to reply. */ 1414 if (replylen > MCLBYTES) { 1415 /* 1416 * XXX: should we try to allocate more? But MCLBYTES 1417 * is probably much larger than IPV6_MMTU... 1418 */ 1419 goto bad; 1420 } 1421 if (replylen > MHLEN) 1422 n = m_getcl(M_NOWAIT, m->m_type, M_PKTHDR); 1423 else 1424 n = m_gethdr(M_NOWAIT, m->m_type); 1425 if (n == NULL) { 1426 m_freem(m); 1427 return (NULL); 1428 } 1429 m_move_pkthdr(n, m); /* just for recvif and FIB */ 1430 n->m_pkthdr.len = n->m_len = replylen; 1431 1432 /* copy mbuf header and IPv6 + Node Information base headers */ 1433 bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr)); 1434 nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1); 1435 bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo)); 1436 1437 /* qtype dependent procedure */ 1438 switch (qtype) { 1439 case NI_QTYPE_NOOP: 1440 nni6->ni_code = ICMP6_NI_SUCCESS; 1441 nni6->ni_flags = 0; 1442 break; 1443 case NI_QTYPE_SUPTYPES: 1444 { 1445 u_int32_t v; 1446 nni6->ni_code = ICMP6_NI_SUCCESS; 1447 nni6->ni_flags = htons(0x0000); /* raw bitmap */ 1448 /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */ 1449 v = (u_int32_t)htonl(0x0000000f); 1450 bcopy(&v, nni6 + 1, sizeof(u_int32_t)); 1451 break; 1452 } 1453 case NI_QTYPE_FQDN: 1454 nni6->ni_code = ICMP6_NI_SUCCESS; 1455 fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) + 1456 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo)); 1457 nni6->ni_flags = 0; /* XXX: meaningless TTL */ 1458 fqdn->ni_fqdn_ttl = 0; /* ditto. */ 1459 /* 1460 * XXX do we really have FQDN in hostname? 1461 */ 1462 mtx_lock(&pr->pr_mtx); 1463 n->m_next = ni6_nametodns(pr->pr_hostname, 1464 strlen(pr->pr_hostname), oldfqdn); 1465 mtx_unlock(&pr->pr_mtx); 1466 if (n->m_next == NULL) 1467 goto bad; 1468 /* XXX we assume that n->m_next is not a chain */ 1469 if (n->m_next->m_next != NULL) 1470 goto bad; 1471 n->m_pkthdr.len += n->m_next->m_len; 1472 break; 1473 case NI_QTYPE_NODEADDR: 1474 { 1475 int lenlim, copied; 1476 1477 nni6->ni_code = ICMP6_NI_SUCCESS; 1478 n->m_pkthdr.len = n->m_len = 1479 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); 1480 lenlim = M_TRAILINGSPACE(n); 1481 copied = ni6_store_addrs(ni6, nni6, ifp, lenlim); 1482 /* XXX: reset mbuf length */ 1483 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + 1484 sizeof(struct icmp6_nodeinfo) + copied; 1485 break; 1486 } 1487 default: 1488 break; /* XXX impossible! */ 1489 } 1490 1491 nni6->ni_type = ICMP6_NI_REPLY; 1492 m_freem(m); 1493 return (n); 1494 1495 bad: 1496 m_freem(m); 1497 if (n) 1498 m_freem(n); 1499 return (NULL); 1500 } 1501 1502 /* 1503 * make a mbuf with DNS-encoded string. no compression support. 1504 * 1505 * XXX names with less than 2 dots (like "foo" or "foo.section") will be 1506 * treated as truncated name (two \0 at the end). this is a wild guess. 1507 * 1508 * old - return pascal string if non-zero 1509 */ 1510 static struct mbuf * 1511 ni6_nametodns(const char *name, int namelen, int old) 1512 { 1513 struct mbuf *m; 1514 char *cp, *ep; 1515 const char *p, *q; 1516 int i, len, nterm; 1517 1518 if (old) 1519 len = namelen + 1; 1520 else 1521 len = MCLBYTES; 1522 1523 /* Because MAXHOSTNAMELEN is usually 256, we use cluster mbuf. */ 1524 if (len > MLEN) 1525 m = m_getcl(M_NOWAIT, MT_DATA, 0); 1526 else 1527 m = m_get(M_NOWAIT, MT_DATA); 1528 if (m == NULL) 1529 goto fail; 1530 1531 if (old) { 1532 m->m_len = len; 1533 *mtod(m, char *) = namelen; 1534 bcopy(name, mtod(m, char *) + 1, namelen); 1535 return m; 1536 } else { 1537 m->m_len = 0; 1538 cp = mtod(m, char *); 1539 ep = mtod(m, char *) + M_TRAILINGSPACE(m); 1540 1541 /* if not certain about my name, return empty buffer */ 1542 if (namelen == 0) 1543 return m; 1544 1545 /* 1546 * guess if it looks like shortened hostname, or FQDN. 1547 * shortened hostname needs two trailing "\0". 1548 */ 1549 i = 0; 1550 for (p = name; p < name + namelen; p++) { 1551 if (*p && *p == '.') 1552 i++; 1553 } 1554 if (i < 2) 1555 nterm = 2; 1556 else 1557 nterm = 1; 1558 1559 p = name; 1560 while (cp < ep && p < name + namelen) { 1561 i = 0; 1562 for (q = p; q < name + namelen && *q && *q != '.'; q++) 1563 i++; 1564 /* result does not fit into mbuf */ 1565 if (cp + i + 1 >= ep) 1566 goto fail; 1567 /* 1568 * DNS label length restriction, RFC1035 page 8. 1569 * "i == 0" case is included here to avoid returning 1570 * 0-length label on "foo..bar". 1571 */ 1572 if (i <= 0 || i >= 64) 1573 goto fail; 1574 *cp++ = i; 1575 bcopy(p, cp, i); 1576 cp += i; 1577 p = q; 1578 if (p < name + namelen && *p == '.') 1579 p++; 1580 } 1581 /* termination */ 1582 if (cp + nterm >= ep) 1583 goto fail; 1584 while (nterm-- > 0) 1585 *cp++ = '\0'; 1586 m->m_len = cp - mtod(m, char *); 1587 return m; 1588 } 1589 1590 panic("should not reach here"); 1591 /* NOTREACHED */ 1592 1593 fail: 1594 if (m) 1595 m_freem(m); 1596 return NULL; 1597 } 1598 1599 /* 1600 * check if two DNS-encoded string matches. takes care of truncated 1601 * form (with \0\0 at the end). no compression support. 1602 * XXX upper/lowercase match (see RFC2065) 1603 */ 1604 static int 1605 ni6_dnsmatch(const char *a, int alen, const char *b, int blen) 1606 { 1607 const char *a0, *b0; 1608 int l; 1609 1610 /* simplest case - need validation? */ 1611 if (alen == blen && bcmp(a, b, alen) == 0) 1612 return 1; 1613 1614 a0 = a; 1615 b0 = b; 1616 1617 /* termination is mandatory */ 1618 if (alen < 2 || blen < 2) 1619 return 0; 1620 if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0') 1621 return 0; 1622 alen--; 1623 blen--; 1624 1625 while (a - a0 < alen && b - b0 < blen) { 1626 if (a - a0 + 1 > alen || b - b0 + 1 > blen) 1627 return 0; 1628 1629 if ((signed char)a[0] < 0 || (signed char)b[0] < 0) 1630 return 0; 1631 /* we don't support compression yet */ 1632 if (a[0] >= 64 || b[0] >= 64) 1633 return 0; 1634 1635 /* truncated case */ 1636 if (a[0] == 0 && a - a0 == alen - 1) 1637 return 1; 1638 if (b[0] == 0 && b - b0 == blen - 1) 1639 return 1; 1640 if (a[0] == 0 || b[0] == 0) 1641 return 0; 1642 1643 if (a[0] != b[0]) 1644 return 0; 1645 l = a[0]; 1646 if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen) 1647 return 0; 1648 if (bcmp(a + 1, b + 1, l) != 0) 1649 return 0; 1650 1651 a += 1 + l; 1652 b += 1 + l; 1653 } 1654 1655 if (a - a0 == alen && b - b0 == blen) 1656 return 1; 1657 else 1658 return 0; 1659 } 1660 1661 /* 1662 * calculate the number of addresses to be returned in the node info reply. 1663 */ 1664 static int 1665 ni6_addrs(struct icmp6_nodeinfo *ni6, struct mbuf *m, struct ifnet **ifpp, 1666 struct in6_addr *subj) 1667 { 1668 struct ifnet *ifp; 1669 struct in6_ifaddr *ifa6; 1670 struct ifaddr *ifa; 1671 int addrs = 0, addrsofif, iffound = 0; 1672 int niflags = ni6->ni_flags; 1673 1674 NET_EPOCH_ASSERT(); 1675 1676 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) { 1677 switch (ni6->ni_code) { 1678 case ICMP6_NI_SUBJ_IPV6: 1679 if (subj == NULL) /* must be impossible... */ 1680 return (0); 1681 break; 1682 default: 1683 /* 1684 * XXX: we only support IPv6 subject address for 1685 * this Qtype. 1686 */ 1687 return (0); 1688 } 1689 } 1690 1691 CK_STAILQ_FOREACH(ifp, &V_ifnet, if_link) { 1692 addrsofif = 0; 1693 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 1694 if (ifa->ifa_addr->sa_family != AF_INET6) 1695 continue; 1696 ifa6 = (struct in6_ifaddr *)ifa; 1697 1698 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 && 1699 IN6_ARE_ADDR_EQUAL(subj, &ifa6->ia_addr.sin6_addr)) 1700 iffound = 1; 1701 1702 /* 1703 * IPv4-mapped addresses can only be returned by a 1704 * Node Information proxy, since they represent 1705 * addresses of IPv4-only nodes, which perforce do 1706 * not implement this protocol. 1707 * [icmp-name-lookups-07, Section 5.4] 1708 * So we don't support NI_NODEADDR_FLAG_COMPAT in 1709 * this function at this moment. 1710 */ 1711 1712 /* What do we have to do about ::1? */ 1713 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { 1714 case IPV6_ADDR_SCOPE_LINKLOCAL: 1715 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) 1716 continue; 1717 break; 1718 case IPV6_ADDR_SCOPE_SITELOCAL: 1719 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) 1720 continue; 1721 break; 1722 case IPV6_ADDR_SCOPE_GLOBAL: 1723 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) 1724 continue; 1725 break; 1726 default: 1727 continue; 1728 } 1729 1730 /* 1731 * check if anycast is okay. 1732 * XXX: just experimental. not in the spec. 1733 */ 1734 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && 1735 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) 1736 continue; /* we need only unicast addresses */ 1737 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && 1738 (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) { 1739 continue; 1740 } 1741 addrsofif++; /* count the address */ 1742 } 1743 if (iffound) { 1744 *ifpp = ifp; 1745 return (addrsofif); 1746 } 1747 1748 addrs += addrsofif; 1749 } 1750 1751 return (addrs); 1752 } 1753 1754 static int 1755 ni6_store_addrs(struct icmp6_nodeinfo *ni6, struct icmp6_nodeinfo *nni6, 1756 struct ifnet *ifp0, int resid) 1757 { 1758 struct ifnet *ifp; 1759 struct in6_ifaddr *ifa6; 1760 struct ifaddr *ifa; 1761 struct ifnet *ifp_dep = NULL; 1762 int copied = 0, allow_deprecated = 0; 1763 u_char *cp = (u_char *)(nni6 + 1); 1764 int niflags = ni6->ni_flags; 1765 u_int32_t ltime; 1766 1767 NET_EPOCH_ASSERT(); 1768 1769 if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL)) 1770 return (0); /* needless to copy */ 1771 1772 ifp = ifp0 ? ifp0 : CK_STAILQ_FIRST(&V_ifnet); 1773 again: 1774 1775 for (; ifp; ifp = CK_STAILQ_NEXT(ifp, if_link)) { 1776 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 1777 if (ifa->ifa_addr->sa_family != AF_INET6) 1778 continue; 1779 ifa6 = (struct in6_ifaddr *)ifa; 1780 1781 if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 && 1782 allow_deprecated == 0) { 1783 /* 1784 * prefererred address should be put before 1785 * deprecated addresses. 1786 */ 1787 1788 /* record the interface for later search */ 1789 if (ifp_dep == NULL) 1790 ifp_dep = ifp; 1791 1792 continue; 1793 } else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 && 1794 allow_deprecated != 0) 1795 continue; /* we now collect deprecated addrs */ 1796 1797 /* What do we have to do about ::1? */ 1798 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { 1799 case IPV6_ADDR_SCOPE_LINKLOCAL: 1800 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) 1801 continue; 1802 break; 1803 case IPV6_ADDR_SCOPE_SITELOCAL: 1804 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) 1805 continue; 1806 break; 1807 case IPV6_ADDR_SCOPE_GLOBAL: 1808 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) 1809 continue; 1810 break; 1811 default: 1812 continue; 1813 } 1814 1815 /* 1816 * check if anycast is okay. 1817 * XXX: just experimental. not in the spec. 1818 */ 1819 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && 1820 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) 1821 continue; 1822 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && 1823 (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) { 1824 continue; 1825 } 1826 1827 /* now we can copy the address */ 1828 if (resid < sizeof(struct in6_addr) + 1829 sizeof(u_int32_t)) { 1830 /* 1831 * We give up much more copy. 1832 * Set the truncate flag and return. 1833 */ 1834 nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE; 1835 return (copied); 1836 } 1837 1838 /* 1839 * Set the TTL of the address. 1840 * The TTL value should be one of the following 1841 * according to the specification: 1842 * 1843 * 1. The remaining lifetime of a DHCP lease on the 1844 * address, or 1845 * 2. The remaining Valid Lifetime of a prefix from 1846 * which the address was derived through Stateless 1847 * Autoconfiguration. 1848 * 1849 * Note that we currently do not support stateful 1850 * address configuration by DHCPv6, so the former 1851 * case can't happen. 1852 */ 1853 if (ifa6->ia6_lifetime.ia6t_expire == 0) 1854 ltime = ND6_INFINITE_LIFETIME; 1855 else { 1856 if (ifa6->ia6_lifetime.ia6t_expire > 1857 time_uptime) 1858 ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_uptime); 1859 else 1860 ltime = 0; 1861 } 1862 1863 bcopy(<ime, cp, sizeof(u_int32_t)); 1864 cp += sizeof(u_int32_t); 1865 1866 /* copy the address itself */ 1867 bcopy(&ifa6->ia_addr.sin6_addr, cp, 1868 sizeof(struct in6_addr)); 1869 in6_clearscope((struct in6_addr *)cp); /* XXX */ 1870 cp += sizeof(struct in6_addr); 1871 1872 resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t)); 1873 copied += (sizeof(struct in6_addr) + sizeof(u_int32_t)); 1874 } 1875 if (ifp0) /* we need search only on the specified IF */ 1876 break; 1877 } 1878 1879 if (allow_deprecated == 0 && ifp_dep != NULL) { 1880 ifp = ifp_dep; 1881 allow_deprecated = 1; 1882 1883 goto again; 1884 } 1885 1886 return (copied); 1887 } 1888 1889 static bool 1890 icmp6_rip6_match(const struct inpcb *inp, void *v) 1891 { 1892 struct ip6_hdr *ip6 = v; 1893 1894 if ((inp->inp_vflag & INP_IPV6) == 0) 1895 return (false); 1896 if (inp->inp_ip_p != IPPROTO_ICMPV6) 1897 return (false); 1898 if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr) && 1899 !IN6_ARE_ADDR_EQUAL(&inp->in6p_laddr, &ip6->ip6_dst)) 1900 return (false); 1901 if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr) && 1902 !IN6_ARE_ADDR_EQUAL(&inp->in6p_faddr, &ip6->ip6_src)) 1903 return (false); 1904 return (true); 1905 } 1906 1907 /* 1908 * XXX almost dup'ed code with rip6_input. 1909 */ 1910 static int 1911 icmp6_rip6_input(struct mbuf **mp, int off) 1912 { 1913 struct mbuf *n, *m = *mp; 1914 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1915 struct inpcb_iterator inpi = INP_ITERATOR(&V_ripcbinfo, 1916 INPLOOKUP_RLOCKPCB, icmp6_rip6_match, ip6); 1917 struct inpcb *inp; 1918 struct sockaddr_in6 fromsa; 1919 struct icmp6_hdr *icmp6; 1920 struct mbuf *opts = NULL; 1921 int delivered = 0; 1922 1923 /* This is assumed to be safe; icmp6_input() does a pullup. */ 1924 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off); 1925 1926 /* 1927 * XXX: the address may have embedded scope zone ID, which should be 1928 * hidden from applications. 1929 */ 1930 bzero(&fromsa, sizeof(fromsa)); 1931 fromsa.sin6_family = AF_INET6; 1932 fromsa.sin6_len = sizeof(struct sockaddr_in6); 1933 fromsa.sin6_addr = ip6->ip6_src; 1934 if (sa6_recoverscope(&fromsa)) { 1935 m_freem(m); 1936 *mp = NULL; 1937 return (IPPROTO_DONE); 1938 } 1939 1940 while ((inp = inp_next(&inpi)) != NULL) { 1941 if (ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type, 1942 inp->in6p_icmp6filt)) 1943 continue; 1944 /* 1945 * Recent network drivers tend to allocate a single 1946 * mbuf cluster, rather than to make a couple of 1947 * mbufs without clusters. Also, since the IPv6 code 1948 * path tries to avoid m_pullup(), it is highly 1949 * probable that we still have an mbuf cluster here 1950 * even though the necessary length can be stored in an 1951 * mbuf's internal buffer. 1952 * Meanwhile, the default size of the receive socket 1953 * buffer for raw sockets is not so large. This means 1954 * the possibility of packet loss is relatively higher 1955 * than before. To avoid this scenario, we copy the 1956 * received data to a separate mbuf that does not use 1957 * a cluster, if possible. 1958 * XXX: it is better to copy the data after stripping 1959 * intermediate headers. 1960 */ 1961 if ((m->m_flags & M_EXT) && m->m_next == NULL && 1962 m->m_len <= MHLEN) { 1963 n = m_get(M_NOWAIT, m->m_type); 1964 if (n != NULL) { 1965 if (m_dup_pkthdr(n, m, M_NOWAIT)) { 1966 bcopy(m->m_data, n->m_data, m->m_len); 1967 n->m_len = m->m_len; 1968 } else { 1969 m_free(n); 1970 n = NULL; 1971 } 1972 } 1973 } else 1974 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 1975 if (n == NULL) 1976 continue; 1977 if (inp->inp_flags & INP_CONTROLOPTS) 1978 ip6_savecontrol(inp, n, &opts); 1979 /* strip intermediate headers */ 1980 m_adj(n, off); 1981 SOCKBUF_LOCK(&inp->inp_socket->so_rcv); 1982 if (sbappendaddr_locked(&inp->inp_socket->so_rcv, 1983 (struct sockaddr *)&fromsa, n, opts) == 0) { 1984 soroverflow_locked(inp->inp_socket); 1985 m_freem(n); 1986 if (opts) 1987 m_freem(opts); 1988 } else { 1989 sorwakeup_locked(inp->inp_socket); 1990 delivered++; 1991 } 1992 opts = NULL; 1993 } 1994 m_freem(m); 1995 *mp = NULL; 1996 if (delivered == 0) 1997 IP6STAT_DEC(ip6s_delivered); 1998 return (IPPROTO_DONE); 1999 } 2000 2001 /* 2002 * Reflect the ip6 packet back to the source. 2003 * OFF points to the icmp6 header, counted from the top of the mbuf. 2004 */ 2005 static void 2006 icmp6_reflect(struct mbuf *m, size_t off) 2007 { 2008 struct in6_addr src6, *srcp; 2009 struct ip6_hdr *ip6; 2010 struct icmp6_hdr *icmp6; 2011 struct in6_ifaddr *ia = NULL; 2012 struct ifnet *outif = NULL; 2013 int plen; 2014 int type, code, hlim; 2015 2016 /* too short to reflect */ 2017 if (off < sizeof(struct ip6_hdr)) { 2018 nd6log((LOG_DEBUG, 2019 "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n", 2020 (u_long)off, (u_long)sizeof(struct ip6_hdr), 2021 __FILE__, __LINE__)); 2022 goto bad; 2023 } 2024 2025 /* 2026 * If there are extra headers between IPv6 and ICMPv6, strip 2027 * off that header first. 2028 */ 2029 #ifdef DIAGNOSTIC 2030 if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN) 2031 panic("assumption failed in icmp6_reflect"); 2032 #endif 2033 if (off > sizeof(struct ip6_hdr)) { 2034 size_t l; 2035 struct ip6_hdr nip6; 2036 2037 l = off - sizeof(struct ip6_hdr); 2038 m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6); 2039 m_adj(m, l); 2040 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 2041 if (m->m_len < l) { 2042 if ((m = m_pullup(m, l)) == NULL) 2043 return; 2044 } 2045 bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6)); 2046 } else /* off == sizeof(struct ip6_hdr) */ { 2047 size_t l; 2048 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 2049 if (m->m_len < l) { 2050 if ((m = m_pullup(m, l)) == NULL) 2051 return; 2052 } 2053 } 2054 plen = m->m_pkthdr.len - sizeof(struct ip6_hdr); 2055 ip6 = mtod(m, struct ip6_hdr *); 2056 ip6->ip6_nxt = IPPROTO_ICMPV6; 2057 icmp6 = (struct icmp6_hdr *)(ip6 + 1); 2058 type = icmp6->icmp6_type; /* keep type for statistics */ 2059 code = icmp6->icmp6_code; /* ditto. */ 2060 hlim = 0; 2061 srcp = NULL; 2062 2063 /* 2064 * If the incoming packet was addressed directly to us (i.e. unicast), 2065 * use dst as the src for the reply. 2066 * The IN6_IFF_NOTREADY case should be VERY rare, but is possible 2067 * (for example) when we encounter an error while forwarding procedure 2068 * destined to a duplicated address of ours. 2069 */ 2070 if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 2071 ia = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */, false); 2072 if (ia != NULL && !(ia->ia6_flags & 2073 (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) { 2074 src6 = ia->ia_addr.sin6_addr; 2075 srcp = &src6; 2076 2077 if (m->m_pkthdr.rcvif != NULL) { 2078 /* XXX: This may not be the outgoing interface */ 2079 hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim; 2080 } else 2081 hlim = V_ip6_defhlim; 2082 } 2083 } 2084 2085 if (srcp == NULL) { 2086 int error; 2087 struct in6_addr dst6; 2088 uint32_t scopeid; 2089 2090 /* 2091 * This case matches to multicasts, our anycast, or unicasts 2092 * that we do not own. Select a source address based on the 2093 * source address of the erroneous packet. 2094 */ 2095 in6_splitscope(&ip6->ip6_src, &dst6, &scopeid); 2096 error = in6_selectsrc_addr(M_GETFIB(m), &dst6, 2097 scopeid, NULL, &src6, &hlim); 2098 2099 if (error) { 2100 char ip6buf[INET6_ADDRSTRLEN]; 2101 nd6log((LOG_DEBUG, 2102 "icmp6_reflect: source can't be determined: " 2103 "dst=%s, error=%d\n", 2104 ip6_sprintf(ip6buf, &ip6->ip6_dst), error)); 2105 goto bad; 2106 } 2107 srcp = &src6; 2108 } 2109 /* 2110 * ip6_input() drops a packet if its src is multicast. 2111 * So, the src is never multicast. 2112 */ 2113 ip6->ip6_dst = ip6->ip6_src; 2114 ip6->ip6_src = *srcp; 2115 ip6->ip6_flow = 0; 2116 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2117 ip6->ip6_vfc |= IPV6_VERSION; 2118 ip6->ip6_nxt = IPPROTO_ICMPV6; 2119 ip6->ip6_hlim = hlim; 2120 2121 icmp6->icmp6_cksum = 0; 2122 icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2123 sizeof(struct ip6_hdr), plen); 2124 2125 /* 2126 * XXX option handling 2127 */ 2128 2129 m->m_flags &= ~(M_BCAST|M_MCAST); 2130 m->m_pkthdr.rcvif = NULL; 2131 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2132 if (outif) 2133 icmp6_ifoutstat_inc(outif, type, code); 2134 2135 return; 2136 2137 bad: 2138 m_freem(m); 2139 return; 2140 } 2141 2142 static const char * 2143 icmp6_redirect_diag(struct in6_addr *src6, struct in6_addr *dst6, 2144 struct in6_addr *tgt6) 2145 { 2146 static char buf[1024]; 2147 char ip6bufs[INET6_ADDRSTRLEN]; 2148 char ip6bufd[INET6_ADDRSTRLEN]; 2149 char ip6buft[INET6_ADDRSTRLEN]; 2150 snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)", 2151 ip6_sprintf(ip6bufs, src6), ip6_sprintf(ip6bufd, dst6), 2152 ip6_sprintf(ip6buft, tgt6)); 2153 return buf; 2154 } 2155 2156 void 2157 icmp6_redirect_input(struct mbuf *m, int off) 2158 { 2159 struct ifnet *ifp; 2160 struct ip6_hdr *ip6; 2161 struct nd_redirect *nd_rd; 2162 struct in6_addr src6, redtgt6, reddst6; 2163 union nd_opts ndopts; 2164 char ip6buf[INET6_ADDRSTRLEN]; 2165 char *lladdr; 2166 int icmp6len, is_onlink, is_router, lladdrlen; 2167 2168 M_ASSERTPKTHDR(m); 2169 KASSERT(m->m_pkthdr.rcvif != NULL, ("%s: no rcvif", __func__)); 2170 2171 /* XXX if we are router, we don't update route by icmp6 redirect */ 2172 if (V_ip6_forwarding) 2173 goto freeit; 2174 if (!V_icmp6_rediraccept) 2175 goto freeit; 2176 2177 /* RFC 6980: Nodes MUST silently ignore fragments */ 2178 if(m->m_flags & M_FRAGMENTED) 2179 goto freeit; 2180 2181 ip6 = mtod(m, struct ip6_hdr *); 2182 icmp6len = ntohs(ip6->ip6_plen); 2183 if (m->m_len < off + icmp6len) { 2184 m = m_pullup(m, off + icmp6len); 2185 if (m == NULL) { 2186 IP6STAT_INC(ip6s_exthdrtoolong); 2187 return; 2188 } 2189 } 2190 ip6 = mtod(m, struct ip6_hdr *); 2191 nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off); 2192 2193 ifp = m->m_pkthdr.rcvif; 2194 redtgt6 = nd_rd->nd_rd_target; 2195 reddst6 = nd_rd->nd_rd_dst; 2196 2197 if (in6_setscope(&redtgt6, ifp, NULL) || 2198 in6_setscope(&reddst6, ifp, NULL)) { 2199 goto freeit; 2200 } 2201 2202 /* validation */ 2203 src6 = ip6->ip6_src; 2204 if (!IN6_IS_ADDR_LINKLOCAL(&src6)) { 2205 nd6log((LOG_ERR, 2206 "ICMP6 redirect sent from %s rejected; " 2207 "must be from linklocal\n", 2208 ip6_sprintf(ip6buf, &src6))); 2209 goto bad; 2210 } 2211 if (__predict_false(ip6->ip6_hlim != 255)) { 2212 ICMP6STAT_INC(icp6s_invlhlim); 2213 nd6log((LOG_ERR, 2214 "ICMP6 redirect sent from %s rejected; " 2215 "hlim=%d (must be 255)\n", 2216 ip6_sprintf(ip6buf, &src6), ip6->ip6_hlim)); 2217 goto bad; 2218 } 2219 { 2220 /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */ 2221 struct nhop_object *nh; 2222 struct in6_addr kdst; 2223 uint32_t scopeid; 2224 2225 in6_splitscope(&reddst6, &kdst, &scopeid); 2226 NET_EPOCH_ASSERT(); 2227 nh = fib6_lookup(ifp->if_fib, &kdst, scopeid, 0, 0); 2228 if (nh != NULL) { 2229 struct in6_addr nh_addr; 2230 nh_addr = ifatoia6(nh->nh_ifa)->ia_addr.sin6_addr; 2231 if ((nh->nh_flags & NHF_GATEWAY) == 0) { 2232 nd6log((LOG_ERR, 2233 "ICMP6 redirect rejected; no route " 2234 "with inet6 gateway found for redirect dst: %s\n", 2235 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2236 goto bad; 2237 } 2238 2239 /* 2240 * Embed scope zone id into next hop address. 2241 */ 2242 nh_addr = nh->gw6_sa.sin6_addr; 2243 2244 if (IN6_ARE_ADDR_EQUAL(&src6, &nh_addr) == 0) { 2245 nd6log((LOG_ERR, 2246 "ICMP6 redirect rejected; " 2247 "not equal to gw-for-src=%s (must be same): " 2248 "%s\n", 2249 ip6_sprintf(ip6buf, &nh_addr), 2250 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2251 goto bad; 2252 } 2253 } else { 2254 nd6log((LOG_ERR, 2255 "ICMP6 redirect rejected; " 2256 "no route found for redirect dst: %s\n", 2257 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2258 goto bad; 2259 } 2260 } 2261 if (IN6_IS_ADDR_MULTICAST(&reddst6)) { 2262 nd6log((LOG_ERR, 2263 "ICMP6 redirect rejected; " 2264 "redirect dst must be unicast: %s\n", 2265 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2266 goto bad; 2267 } 2268 2269 is_router = is_onlink = 0; 2270 if (IN6_IS_ADDR_LINKLOCAL(&redtgt6)) 2271 is_router = 1; /* router case */ 2272 if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0) 2273 is_onlink = 1; /* on-link destination case */ 2274 if (!is_router && !is_onlink) { 2275 nd6log((LOG_ERR, 2276 "ICMP6 redirect rejected; " 2277 "neither router case nor onlink case: %s\n", 2278 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2279 goto bad; 2280 } 2281 2282 icmp6len -= sizeof(*nd_rd); 2283 nd6_option_init(nd_rd + 1, icmp6len, &ndopts); 2284 if (nd6_options(&ndopts) < 0) { 2285 nd6log((LOG_INFO, "%s: invalid ND option, rejected: %s\n", 2286 __func__, icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2287 /* nd6_options have incremented stats */ 2288 goto freeit; 2289 } 2290 2291 lladdr = NULL; 2292 lladdrlen = 0; 2293 if (ndopts.nd_opts_tgt_lladdr) { 2294 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 2295 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 2296 } 2297 2298 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 2299 nd6log((LOG_INFO, "%s: lladdrlen mismatch for %s " 2300 "(if %d, icmp6 packet %d): %s\n", 2301 __func__, ip6_sprintf(ip6buf, &redtgt6), 2302 ifp->if_addrlen, lladdrlen - 2, 2303 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2304 goto bad; 2305 } 2306 2307 /* Validation passed. */ 2308 2309 /* RFC 2461 8.3 */ 2310 nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT, 2311 is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER); 2312 2313 /* 2314 * Install a gateway route in the better-router case or an interface 2315 * route in the on-link-destination case. 2316 */ 2317 { 2318 struct sockaddr_in6 sdst; 2319 struct sockaddr_in6 sgw; 2320 struct sockaddr_in6 ssrc; 2321 struct sockaddr *gw; 2322 int rt_flags; 2323 u_int fibnum; 2324 2325 bzero(&sdst, sizeof(sdst)); 2326 bzero(&ssrc, sizeof(ssrc)); 2327 sdst.sin6_family = ssrc.sin6_family = AF_INET6; 2328 sdst.sin6_len = ssrc.sin6_len = sizeof(struct sockaddr_in6); 2329 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr)); 2330 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr)); 2331 rt_flags = 0; 2332 if (is_router) { 2333 bzero(&sgw, sizeof(sgw)); 2334 sgw.sin6_family = AF_INET6; 2335 sgw.sin6_len = sizeof(struct sockaddr_in6); 2336 bcopy(&redtgt6, &sgw.sin6_addr, 2337 sizeof(struct in6_addr)); 2338 gw = (struct sockaddr *)&sgw; 2339 rt_flags |= RTF_GATEWAY; 2340 } else 2341 gw = ifp->if_addr->ifa_addr; 2342 for (fibnum = 0; fibnum < rt_numfibs; fibnum++) 2343 rib_add_redirect(fibnum, (struct sockaddr *)&sdst, gw, 2344 (struct sockaddr *)&ssrc, ifp, rt_flags, 2345 V_icmp6_redirtimeout); 2346 } 2347 2348 freeit: 2349 m_freem(m); 2350 return; 2351 2352 bad: 2353 ICMP6STAT_INC(icp6s_badredirect); 2354 m_freem(m); 2355 } 2356 2357 void 2358 icmp6_redirect_output(struct mbuf *m0, struct nhop_object *nh) 2359 { 2360 struct ifnet *ifp; /* my outgoing interface */ 2361 struct in6_addr *ifp_ll6; 2362 struct in6_addr *router_ll6; 2363 struct ip6_hdr *sip6; /* m0 as struct ip6_hdr */ 2364 struct mbuf *m = NULL; /* newly allocated one */ 2365 struct m_tag *mtag; 2366 struct ip6_hdr *ip6; /* m as struct ip6_hdr */ 2367 struct nd_redirect *nd_rd; 2368 struct llentry *ln = NULL; 2369 size_t maxlen; 2370 u_char *p; 2371 struct ifnet *outif = NULL; 2372 struct sockaddr_in6 src_sa; 2373 2374 icmp6_errcount(ND_REDIRECT, 0); 2375 2376 /* if we are not router, we don't send icmp6 redirect */ 2377 if (!V_ip6_forwarding) 2378 goto fail; 2379 2380 /* sanity check */ 2381 if (!m0 || !nh || !(NH_IS_VALID(nh)) || !(ifp = nh->nh_ifp)) 2382 goto fail; 2383 2384 /* 2385 * Address check: 2386 * the source address must identify a neighbor, and 2387 * the destination address must not be a multicast address 2388 * [RFC 2461, sec 8.2] 2389 */ 2390 sip6 = mtod(m0, struct ip6_hdr *); 2391 bzero(&src_sa, sizeof(src_sa)); 2392 src_sa.sin6_family = AF_INET6; 2393 src_sa.sin6_len = sizeof(src_sa); 2394 src_sa.sin6_addr = sip6->ip6_src; 2395 if (nd6_is_addr_neighbor(&src_sa, ifp) == 0) 2396 goto fail; 2397 if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst)) 2398 goto fail; /* what should we do here? */ 2399 2400 /* rate limit */ 2401 if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0)) 2402 goto fail; 2403 2404 /* 2405 * Since we are going to append up to 1280 bytes (= IPV6_MMTU), 2406 * we almost always ask for an mbuf cluster for simplicity. 2407 * (MHLEN < IPV6_MMTU is almost always true) 2408 */ 2409 #if IPV6_MMTU >= MCLBYTES 2410 # error assumption failed about IPV6_MMTU and MCLBYTES 2411 #endif 2412 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 2413 if (m == NULL) 2414 goto fail; 2415 M_SETFIB(m, M_GETFIB(m0)); 2416 maxlen = M_TRAILINGSPACE(m); 2417 maxlen = min(IPV6_MMTU, maxlen); 2418 /* just for safety */ 2419 if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) + 2420 ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) { 2421 goto fail; 2422 } 2423 2424 { 2425 /* get ip6 linklocal address for ifp(my outgoing interface). */ 2426 struct in6_ifaddr *ia; 2427 if ((ia = in6ifa_ifpforlinklocal(ifp, 2428 IN6_IFF_NOTREADY| 2429 IN6_IFF_ANYCAST)) == NULL) 2430 goto fail; 2431 ifp_ll6 = &ia->ia_addr.sin6_addr; 2432 /* XXXRW: reference released prematurely. */ 2433 ifa_free(&ia->ia_ifa); 2434 } 2435 2436 /* get ip6 linklocal address for the router. */ 2437 if (nh->nh_flags & NHF_GATEWAY) { 2438 struct sockaddr_in6 *sin6; 2439 sin6 = &nh->gw6_sa; 2440 router_ll6 = &sin6->sin6_addr; 2441 if (!IN6_IS_ADDR_LINKLOCAL(router_ll6)) 2442 router_ll6 = (struct in6_addr *)NULL; 2443 } else 2444 router_ll6 = (struct in6_addr *)NULL; 2445 2446 /* ip6 */ 2447 ip6 = mtod(m, struct ip6_hdr *); 2448 ip6->ip6_flow = 0; 2449 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2450 ip6->ip6_vfc |= IPV6_VERSION; 2451 /* ip6->ip6_plen will be set later */ 2452 ip6->ip6_nxt = IPPROTO_ICMPV6; 2453 ip6->ip6_hlim = 255; 2454 /* ip6->ip6_src must be linklocal addr for my outgoing if. */ 2455 bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr)); 2456 bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr)); 2457 2458 /* ND Redirect */ 2459 nd_rd = (struct nd_redirect *)(ip6 + 1); 2460 nd_rd->nd_rd_type = ND_REDIRECT; 2461 nd_rd->nd_rd_code = 0; 2462 nd_rd->nd_rd_reserved = 0; 2463 if (nh->nh_flags & NHF_GATEWAY) { 2464 /* 2465 * nd_rd->nd_rd_target must be a link-local address in 2466 * better router cases. 2467 */ 2468 if (!router_ll6) 2469 goto fail; 2470 bcopy(router_ll6, &nd_rd->nd_rd_target, 2471 sizeof(nd_rd->nd_rd_target)); 2472 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2473 sizeof(nd_rd->nd_rd_dst)); 2474 } else { 2475 /* make sure redtgt == reddst */ 2476 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target, 2477 sizeof(nd_rd->nd_rd_target)); 2478 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2479 sizeof(nd_rd->nd_rd_dst)); 2480 } 2481 2482 p = (u_char *)(nd_rd + 1); 2483 2484 if (!router_ll6) 2485 goto nolladdropt; 2486 2487 { 2488 /* target lladdr option */ 2489 int len; 2490 struct nd_opt_hdr *nd_opt; 2491 char *lladdr; 2492 2493 ln = nd6_lookup(router_ll6, LLE_SF(AF_INET6, 0), ifp); 2494 if (ln == NULL) 2495 goto nolladdropt; 2496 2497 len = sizeof(*nd_opt) + ifp->if_addrlen; 2498 len = (len + 7) & ~7; /* round by 8 */ 2499 /* safety check */ 2500 if (len + (p - (u_char *)ip6) > maxlen) 2501 goto nolladdropt; 2502 2503 if (ln->la_flags & LLE_VALID) { 2504 nd_opt = (struct nd_opt_hdr *)p; 2505 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 2506 nd_opt->nd_opt_len = len >> 3; 2507 lladdr = (char *)(nd_opt + 1); 2508 bcopy(ln->ll_addr, lladdr, ifp->if_addrlen); 2509 p += len; 2510 } 2511 } 2512 nolladdropt: 2513 if (ln != NULL) 2514 LLE_RUNLOCK(ln); 2515 2516 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2517 2518 /* just to be safe */ 2519 #ifdef M_DECRYPTED /*not openbsd*/ 2520 if (m0->m_flags & M_DECRYPTED) 2521 goto noredhdropt; 2522 #endif 2523 if (p - (u_char *)ip6 > maxlen) 2524 goto noredhdropt; 2525 2526 { 2527 /* redirected header option */ 2528 int len; 2529 struct nd_opt_rd_hdr *nd_opt_rh; 2530 2531 /* 2532 * compute the maximum size for icmp6 redirect header option. 2533 * XXX room for auth header? 2534 */ 2535 len = maxlen - (p - (u_char *)ip6); 2536 len &= ~7; 2537 2538 /* This is just for simplicity. */ 2539 if (m0->m_pkthdr.len != m0->m_len) { 2540 if (m0->m_next) { 2541 m_freem(m0->m_next); 2542 m0->m_next = NULL; 2543 } 2544 m0->m_pkthdr.len = m0->m_len; 2545 } 2546 2547 /* 2548 * Redirected header option spec (RFC2461 4.6.3) talks nothing 2549 * about padding/truncate rule for the original IP packet. 2550 * From the discussion on IPv6imp in Feb 1999, 2551 * the consensus was: 2552 * - "attach as much as possible" is the goal 2553 * - pad if not aligned (original size can be guessed by 2554 * original ip6 header) 2555 * Following code adds the padding if it is simple enough, 2556 * and truncates if not. 2557 */ 2558 if (m0->m_next || m0->m_pkthdr.len != m0->m_len) 2559 panic("assumption failed in %s:%d", __FILE__, 2560 __LINE__); 2561 2562 if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) { 2563 /* not enough room, truncate */ 2564 m0->m_pkthdr.len = m0->m_len = len - 2565 sizeof(*nd_opt_rh); 2566 } else { 2567 /* enough room, pad or truncate */ 2568 size_t extra; 2569 2570 extra = m0->m_pkthdr.len % 8; 2571 if (extra) { 2572 /* pad if easy enough, truncate if not */ 2573 if (8 - extra <= M_TRAILINGSPACE(m0)) { 2574 /* pad */ 2575 m0->m_len += (8 - extra); 2576 m0->m_pkthdr.len += (8 - extra); 2577 } else { 2578 /* truncate */ 2579 m0->m_pkthdr.len -= extra; 2580 m0->m_len -= extra; 2581 } 2582 } 2583 len = m0->m_pkthdr.len + sizeof(*nd_opt_rh); 2584 m0->m_pkthdr.len = m0->m_len = len - 2585 sizeof(*nd_opt_rh); 2586 } 2587 2588 nd_opt_rh = (struct nd_opt_rd_hdr *)p; 2589 bzero(nd_opt_rh, sizeof(*nd_opt_rh)); 2590 nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER; 2591 nd_opt_rh->nd_opt_rh_len = len >> 3; 2592 p += sizeof(*nd_opt_rh); 2593 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2594 2595 /* connect m0 to m */ 2596 m_tag_delete_chain(m0, NULL); 2597 m0->m_flags &= ~M_PKTHDR; 2598 m->m_next = m0; 2599 m->m_pkthdr.len = m->m_len + m0->m_len; 2600 m0 = NULL; 2601 } 2602 noredhdropt:; 2603 if (m0) { 2604 m_freem(m0); 2605 m0 = NULL; 2606 } 2607 2608 /* XXX: clear embedded link IDs in the inner header */ 2609 in6_clearscope(&sip6->ip6_src); 2610 in6_clearscope(&sip6->ip6_dst); 2611 in6_clearscope(&nd_rd->nd_rd_target); 2612 in6_clearscope(&nd_rd->nd_rd_dst); 2613 2614 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr)); 2615 2616 nd_rd->nd_rd_cksum = 0; 2617 nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2618 sizeof(*ip6), ntohs(ip6->ip6_plen)); 2619 2620 if (send_sendso_input_hook != NULL) { 2621 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, sizeof(unsigned short), 2622 M_NOWAIT); 2623 if (mtag == NULL) 2624 goto fail; 2625 *(unsigned short *)(mtag + 1) = nd_rd->nd_rd_type; 2626 m_tag_prepend(m, mtag); 2627 } 2628 2629 /* send the packet to outside... */ 2630 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2631 if (outif) { 2632 icmp6_ifstat_inc(outif, ifs6_out_msg); 2633 icmp6_ifstat_inc(outif, ifs6_out_redirect); 2634 } 2635 ICMP6STAT_INC(icp6s_outhist[ND_REDIRECT]); 2636 2637 return; 2638 2639 fail: 2640 if (m) 2641 m_freem(m); 2642 if (m0) 2643 m_freem(m0); 2644 } 2645 2646 /* 2647 * ICMPv6 socket option processing. 2648 */ 2649 int 2650 icmp6_ctloutput(struct socket *so, struct sockopt *sopt) 2651 { 2652 int error = 0; 2653 int optlen; 2654 struct inpcb *inp = sotoinpcb(so); 2655 int level, op, optname; 2656 2657 if (sopt) { 2658 level = sopt->sopt_level; 2659 op = sopt->sopt_dir; 2660 optname = sopt->sopt_name; 2661 optlen = sopt->sopt_valsize; 2662 } else 2663 level = op = optname = optlen = 0; 2664 2665 if (level != IPPROTO_ICMPV6) { 2666 return EINVAL; 2667 } 2668 2669 switch (op) { 2670 case PRCO_SETOPT: 2671 switch (optname) { 2672 case ICMP6_FILTER: 2673 { 2674 struct icmp6_filter ic6f; 2675 2676 if (optlen != sizeof(ic6f)) { 2677 error = EMSGSIZE; 2678 break; 2679 } 2680 error = sooptcopyin(sopt, &ic6f, optlen, optlen); 2681 if (error == 0) { 2682 INP_WLOCK(inp); 2683 *inp->in6p_icmp6filt = ic6f; 2684 INP_WUNLOCK(inp); 2685 } 2686 break; 2687 } 2688 2689 default: 2690 error = ENOPROTOOPT; 2691 break; 2692 } 2693 break; 2694 2695 case PRCO_GETOPT: 2696 switch (optname) { 2697 case ICMP6_FILTER: 2698 { 2699 struct icmp6_filter ic6f; 2700 2701 INP_RLOCK(inp); 2702 ic6f = *inp->in6p_icmp6filt; 2703 INP_RUNLOCK(inp); 2704 error = sooptcopyout(sopt, &ic6f, sizeof(ic6f)); 2705 break; 2706 } 2707 2708 default: 2709 error = ENOPROTOOPT; 2710 break; 2711 } 2712 break; 2713 } 2714 2715 return (error); 2716 } 2717 2718 /* 2719 * Perform rate limit check. 2720 * Returns 0 if it is okay to send the icmp6 packet. 2721 * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate 2722 * limitation. 2723 * 2724 * XXX per-destination/type check necessary? 2725 * 2726 * dst - not used at this moment 2727 * type - not used at this moment 2728 * code - not used at this moment 2729 */ 2730 static int 2731 icmp6_ratelimit(const struct in6_addr *dst, const int type, 2732 const int code) 2733 { 2734 int ret; 2735 2736 ret = 0; /* okay to send */ 2737 2738 /* PPS limit */ 2739 if (!ppsratecheck(&V_icmp6errppslim_last, &V_icmp6errpps_count, 2740 V_icmp6errppslim)) { 2741 /* The packet is subject to rate limit */ 2742 ret++; 2743 } 2744 2745 return ret; 2746 } 2747