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 static VNET_DEFINE(int, icmp6errpps_count) = 0; 128 static VNET_DEFINE(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); 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 /* 387 * icmp6_reflect() is designed to be in the input path. 388 * icmp6_error() can be called from both input and output path, 389 * and if we are in output path rcvif could contain bogus value. 390 * clear m->m_pkthdr.rcvif for safety, we should have enough scope 391 * information in ip header (nip6). 392 */ 393 m->m_pkthdr.rcvif = NULL; 394 395 ICMP6STAT_INC(icp6s_outhist[type]); 396 icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */ 397 398 return; 399 400 freeit: 401 /* 402 * If we can't tell whether or not we can generate ICMP6, free it. 403 */ 404 m_freem(m); 405 } 406 407 /* 408 * Process a received ICMP6 message. 409 */ 410 int 411 icmp6_input(struct mbuf **mp, int *offp, int proto) 412 { 413 struct mbuf *m = *mp, *n; 414 struct ifnet *ifp; 415 struct ip6_hdr *ip6, *nip6; 416 struct icmp6_hdr *icmp6, *nicmp6; 417 int off = *offp; 418 int icmp6len = m->m_pkthdr.len - *offp; 419 int code, sum, noff; 420 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 421 int ip6len, error; 422 423 ifp = m->m_pkthdr.rcvif; 424 425 #ifndef PULLDOWN_TEST 426 IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_hdr), IPPROTO_DONE); 427 /* m might change if M_LOOP. So, call mtod after this */ 428 #endif 429 430 /* 431 * Locate icmp6 structure in mbuf, and check 432 * that not corrupted and of at least minimum length 433 */ 434 435 ip6 = mtod(m, struct ip6_hdr *); 436 ip6len = sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen); 437 if (icmp6len < sizeof(struct icmp6_hdr)) { 438 ICMP6STAT_INC(icp6s_tooshort); 439 goto freeit; 440 } 441 442 /* 443 * Check multicast group membership. 444 * Note: SSM filters are not applied for ICMPv6 traffic. 445 */ 446 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 447 struct in6_multi *inm; 448 449 inm = in6m_lookup(ifp, &ip6->ip6_dst); 450 if (inm == NULL) { 451 IP6STAT_INC(ip6s_notmember); 452 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 453 goto freeit; 454 } 455 } 456 457 /* 458 * calculate the checksum 459 */ 460 #ifndef PULLDOWN_TEST 461 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off); 462 #else 463 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6)); 464 if (icmp6 == NULL) { 465 ICMP6STAT_INC(icp6s_tooshort); 466 return IPPROTO_DONE; 467 } 468 #endif 469 code = icmp6->icmp6_code; 470 471 if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) { 472 nd6log((LOG_ERR, 473 "ICMP6 checksum error(%d|%x) %s\n", 474 icmp6->icmp6_type, sum, 475 ip6_sprintf(ip6bufs, &ip6->ip6_src))); 476 ICMP6STAT_INC(icp6s_checksum); 477 goto freeit; 478 } 479 480 ICMP6STAT_INC(icp6s_inhist[icmp6->icmp6_type]); 481 icmp6_ifstat_inc(ifp, ifs6_in_msg); 482 if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK) 483 icmp6_ifstat_inc(ifp, ifs6_in_error); 484 485 switch (icmp6->icmp6_type) { 486 case ICMP6_DST_UNREACH: 487 icmp6_ifstat_inc(ifp, ifs6_in_dstunreach); 488 switch (code) { 489 case ICMP6_DST_UNREACH_NOROUTE: 490 case ICMP6_DST_UNREACH_ADDR: /* PRC_HOSTDEAD is a DOS */ 491 code = PRC_UNREACH_NET; 492 break; 493 case ICMP6_DST_UNREACH_ADMIN: 494 icmp6_ifstat_inc(ifp, ifs6_in_adminprohib); 495 code = PRC_UNREACH_ADMIN_PROHIB; 496 break; 497 case ICMP6_DST_UNREACH_BEYONDSCOPE: 498 /* I mean "source address was incorrect." */ 499 code = PRC_PARAMPROB; 500 break; 501 case ICMP6_DST_UNREACH_NOPORT: 502 code = PRC_UNREACH_PORT; 503 break; 504 default: 505 goto badcode; 506 } 507 goto deliver; 508 break; 509 510 case ICMP6_PACKET_TOO_BIG: 511 icmp6_ifstat_inc(ifp, ifs6_in_pkttoobig); 512 513 /* validation is made in icmp6_mtudisc_update */ 514 515 code = PRC_MSGSIZE; 516 517 /* 518 * Updating the path MTU will be done after examining 519 * intermediate extension headers. 520 */ 521 goto deliver; 522 break; 523 524 case ICMP6_TIME_EXCEEDED: 525 icmp6_ifstat_inc(ifp, ifs6_in_timeexceed); 526 switch (code) { 527 case ICMP6_TIME_EXCEED_TRANSIT: 528 code = PRC_TIMXCEED_INTRANS; 529 break; 530 case ICMP6_TIME_EXCEED_REASSEMBLY: 531 code = PRC_TIMXCEED_REASS; 532 break; 533 default: 534 goto badcode; 535 } 536 goto deliver; 537 break; 538 539 case ICMP6_PARAM_PROB: 540 icmp6_ifstat_inc(ifp, ifs6_in_paramprob); 541 switch (code) { 542 case ICMP6_PARAMPROB_NEXTHEADER: 543 code = PRC_UNREACH_PROTOCOL; 544 break; 545 case ICMP6_PARAMPROB_HEADER: 546 case ICMP6_PARAMPROB_OPTION: 547 code = PRC_PARAMPROB; 548 break; 549 default: 550 goto badcode; 551 } 552 goto deliver; 553 break; 554 555 case ICMP6_ECHO_REQUEST: 556 icmp6_ifstat_inc(ifp, ifs6_in_echo); 557 if (code != 0) 558 goto badcode; 559 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) { 560 /* Give up remote */ 561 break; 562 } 563 if (!M_WRITABLE(n) 564 || n->m_len < off + sizeof(struct icmp6_hdr)) { 565 struct mbuf *n0 = n; 566 int n0len; 567 568 CTASSERT(sizeof(*nip6) + sizeof(*nicmp6) <= MHLEN); 569 n = m_gethdr(M_NOWAIT, n0->m_type); 570 if (n == NULL) { 571 /* Give up remote */ 572 m_freem(n0); 573 break; 574 } 575 576 m_move_pkthdr(n, n0); /* FIB copied. */ 577 n0len = n0->m_pkthdr.len; /* save for use below */ 578 /* 579 * Copy IPv6 and ICMPv6 only. 580 */ 581 nip6 = mtod(n, struct ip6_hdr *); 582 bcopy(ip6, nip6, sizeof(struct ip6_hdr)); 583 nicmp6 = (struct icmp6_hdr *)(nip6 + 1); 584 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr)); 585 noff = sizeof(struct ip6_hdr); 586 /* new mbuf contains only ipv6+icmpv6 headers */ 587 n->m_len = noff + sizeof(struct icmp6_hdr); 588 /* 589 * Adjust mbuf. ip6_plen will be adjusted in 590 * ip6_output(). 591 */ 592 m_adj(n0, off + sizeof(struct icmp6_hdr)); 593 /* recalculate complete packet size */ 594 n->m_pkthdr.len = n0len + (noff - off); 595 n->m_next = n0; 596 } else { 597 nip6 = mtod(n, struct ip6_hdr *); 598 IP6_EXTHDR_GET(nicmp6, struct icmp6_hdr *, n, off, 599 sizeof(*nicmp6)); 600 noff = off; 601 } 602 if (n) { 603 nicmp6->icmp6_type = ICMP6_ECHO_REPLY; 604 nicmp6->icmp6_code = 0; 605 ICMP6STAT_INC(icp6s_reflect); 606 ICMP6STAT_INC(icp6s_outhist[ICMP6_ECHO_REPLY]); 607 icmp6_reflect(n, noff); 608 } 609 break; 610 611 case ICMP6_ECHO_REPLY: 612 icmp6_ifstat_inc(ifp, ifs6_in_echoreply); 613 if (code != 0) 614 goto badcode; 615 break; 616 617 case MLD_LISTENER_QUERY: 618 case MLD_LISTENER_REPORT: 619 case MLD_LISTENER_DONE: 620 case MLDV2_LISTENER_REPORT: 621 /* 622 * Drop MLD traffic which is not link-local, has a hop limit 623 * of greater than 1 hop, or which does not have the 624 * IPv6 HBH Router Alert option. 625 * As IPv6 HBH options are stripped in ip6_input() we must 626 * check an mbuf header flag. 627 * XXX Should we also sanity check that these messages 628 * were directed to a link-local multicast prefix? 629 */ 630 if ((ip6->ip6_hlim != 1) || (m->m_flags & M_RTALERT_MLD) == 0) 631 goto freeit; 632 if (mld_input(m, off, icmp6len) != 0) 633 return (IPPROTO_DONE); 634 /* m stays. */ 635 break; 636 637 case ICMP6_WRUREQUEST: /* ICMP6_FQDN_QUERY */ 638 { 639 enum { WRU, FQDN } mode; 640 641 if (!V_icmp6_nodeinfo) 642 break; 643 644 if (icmp6len == sizeof(struct icmp6_hdr) + 4) 645 mode = WRU; 646 else if (icmp6len >= sizeof(struct icmp6_nodeinfo)) 647 mode = FQDN; 648 else 649 goto badlen; 650 651 if (mode == FQDN) { 652 #ifndef PULLDOWN_TEST 653 IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_nodeinfo), 654 IPPROTO_DONE); 655 #endif 656 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 657 if (n) 658 n = ni6_input(n, off); 659 /* XXX meaningless if n == NULL */ 660 noff = sizeof(struct ip6_hdr); 661 } else { 662 struct prison *pr; 663 u_char *p; 664 int maxhlen, hlen; 665 666 /* 667 * XXX: this combination of flags is pointless, 668 * but should we keep this for compatibility? 669 */ 670 if ((V_icmp6_nodeinfo & (ICMP6_NODEINFO_FQDNOK | 671 ICMP6_NODEINFO_TMPADDROK)) != 672 (ICMP6_NODEINFO_FQDNOK | ICMP6_NODEINFO_TMPADDROK)) 673 break; 674 675 if (code != 0) 676 goto badcode; 677 678 CTASSERT(sizeof(*nip6) + sizeof(*nicmp6) + 4 <= MHLEN); 679 n = m_gethdr(M_NOWAIT, m->m_type); 680 if (n == NULL) { 681 /* Give up remote */ 682 break; 683 } 684 if (!m_dup_pkthdr(n, m, M_NOWAIT)) { 685 /* 686 * Previous code did a blind M_COPY_PKTHDR 687 * and said "just for rcvif". If true, then 688 * we could tolerate the dup failing (due to 689 * the deep copy of the tag chain). For now 690 * be conservative and just fail. 691 */ 692 m_free(n); 693 n = NULL; 694 break; 695 } 696 maxhlen = M_TRAILINGSPACE(n) - 697 (sizeof(*nip6) + sizeof(*nicmp6) + 4); 698 pr = curthread->td_ucred->cr_prison; 699 mtx_lock(&pr->pr_mtx); 700 hlen = strlen(pr->pr_hostname); 701 if (maxhlen > hlen) 702 maxhlen = hlen; 703 /* 704 * Copy IPv6 and ICMPv6 only. 705 */ 706 nip6 = mtod(n, struct ip6_hdr *); 707 bcopy(ip6, nip6, sizeof(struct ip6_hdr)); 708 nicmp6 = (struct icmp6_hdr *)(nip6 + 1); 709 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr)); 710 p = (u_char *)(nicmp6 + 1); 711 bzero(p, 4); 712 /* meaningless TTL */ 713 bcopy(pr->pr_hostname, p + 4, maxhlen); 714 mtx_unlock(&pr->pr_mtx); 715 noff = sizeof(struct ip6_hdr); 716 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + 717 sizeof(struct icmp6_hdr) + 4 + maxhlen; 718 nicmp6->icmp6_type = ICMP6_WRUREPLY; 719 nicmp6->icmp6_code = 0; 720 } 721 if (n) { 722 ICMP6STAT_INC(icp6s_reflect); 723 ICMP6STAT_INC(icp6s_outhist[ICMP6_WRUREPLY]); 724 icmp6_reflect(n, noff); 725 } 726 break; 727 } 728 729 case ICMP6_WRUREPLY: 730 if (code != 0) 731 goto badcode; 732 break; 733 734 case ND_ROUTER_SOLICIT: 735 icmp6_ifstat_inc(ifp, ifs6_in_routersolicit); 736 if (code != 0) 737 goto badcode; 738 if (icmp6len < sizeof(struct nd_router_solicit)) 739 goto badlen; 740 if (send_sendso_input_hook != NULL) { 741 IP6_EXTHDR_CHECK(m, off, icmp6len, IPPROTO_DONE); 742 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 743 if (error == 0) { 744 m = NULL; 745 goto freeit; 746 } 747 } 748 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 749 nd6_rs_input(m, off, icmp6len); 750 m = n; 751 if (m == NULL) 752 goto freeit; 753 break; 754 755 case ND_ROUTER_ADVERT: 756 icmp6_ifstat_inc(ifp, ifs6_in_routeradvert); 757 if (code != 0) 758 goto badcode; 759 if (icmp6len < sizeof(struct nd_router_advert)) 760 goto badlen; 761 if (send_sendso_input_hook != NULL) { 762 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 763 if (error == 0) { 764 m = NULL; 765 goto freeit; 766 } 767 } 768 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 769 nd6_ra_input(m, off, icmp6len); 770 m = n; 771 if (m == NULL) 772 goto freeit; 773 break; 774 775 case ND_NEIGHBOR_SOLICIT: 776 icmp6_ifstat_inc(ifp, ifs6_in_neighborsolicit); 777 if (code != 0) 778 goto badcode; 779 if (icmp6len < sizeof(struct nd_neighbor_solicit)) 780 goto badlen; 781 if (send_sendso_input_hook != NULL) { 782 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 783 if (error == 0) { 784 m = NULL; 785 goto freeit; 786 } 787 } 788 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 789 nd6_ns_input(m, off, icmp6len); 790 m = n; 791 if (m == NULL) 792 goto freeit; 793 break; 794 795 case ND_NEIGHBOR_ADVERT: 796 icmp6_ifstat_inc(ifp, ifs6_in_neighboradvert); 797 if (code != 0) 798 goto badcode; 799 if (icmp6len < sizeof(struct nd_neighbor_advert)) 800 goto badlen; 801 if (send_sendso_input_hook != NULL) { 802 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 803 if (error == 0) { 804 m = NULL; 805 goto freeit; 806 } 807 } 808 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 809 nd6_na_input(m, off, icmp6len); 810 m = n; 811 if (m == NULL) 812 goto freeit; 813 break; 814 815 case ND_REDIRECT: 816 icmp6_ifstat_inc(ifp, ifs6_in_redirect); 817 if (code != 0) 818 goto badcode; 819 if (icmp6len < sizeof(struct nd_redirect)) 820 goto badlen; 821 if (send_sendso_input_hook != NULL) { 822 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 823 if (error == 0) { 824 m = NULL; 825 goto freeit; 826 } 827 } 828 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 829 icmp6_redirect_input(m, off); 830 m = n; 831 if (m == NULL) 832 goto freeit; 833 break; 834 835 case ICMP6_ROUTER_RENUMBERING: 836 if (code != ICMP6_ROUTER_RENUMBERING_COMMAND && 837 code != ICMP6_ROUTER_RENUMBERING_RESULT) 838 goto badcode; 839 if (icmp6len < sizeof(struct icmp6_router_renum)) 840 goto badlen; 841 break; 842 843 default: 844 nd6log((LOG_DEBUG, 845 "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n", 846 icmp6->icmp6_type, ip6_sprintf(ip6bufs, &ip6->ip6_src), 847 ip6_sprintf(ip6bufd, &ip6->ip6_dst), 848 ifp ? ifp->if_index : 0)); 849 if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) { 850 /* ICMPv6 error: MUST deliver it by spec... */ 851 code = PRC_NCMDS; 852 /* deliver */ 853 } else { 854 /* ICMPv6 informational: MUST not deliver */ 855 break; 856 } 857 deliver: 858 if (icmp6_notify_error(&m, off, icmp6len, code) != 0) { 859 /* In this case, m should've been freed. */ 860 return (IPPROTO_DONE); 861 } 862 break; 863 864 badcode: 865 ICMP6STAT_INC(icp6s_badcode); 866 break; 867 868 badlen: 869 ICMP6STAT_INC(icp6s_badlen); 870 break; 871 } 872 873 /* deliver the packet to appropriate sockets */ 874 icmp6_rip6_input(&m, *offp); 875 876 return IPPROTO_DONE; 877 878 freeit: 879 m_freem(m); 880 return IPPROTO_DONE; 881 } 882 883 static int 884 icmp6_notify_error(struct mbuf **mp, int off, int icmp6len, int code) 885 { 886 struct mbuf *m = *mp; 887 struct icmp6_hdr *icmp6; 888 struct ip6_hdr *eip6; 889 u_int32_t notifymtu; 890 struct sockaddr_in6 icmp6src, icmp6dst; 891 892 if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) { 893 ICMP6STAT_INC(icp6s_tooshort); 894 goto freeit; 895 } 896 #ifndef PULLDOWN_TEST 897 IP6_EXTHDR_CHECK(m, off, 898 sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr), -1); 899 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 900 #else 901 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, 902 sizeof(*icmp6) + sizeof(struct ip6_hdr)); 903 if (icmp6 == NULL) { 904 ICMP6STAT_INC(icp6s_tooshort); 905 return (-1); 906 } 907 #endif 908 eip6 = (struct ip6_hdr *)(icmp6 + 1); 909 910 /* Detect the upper level protocol */ 911 { 912 void (*ctlfunc)(int, struct sockaddr *, void *); 913 u_int8_t nxt = eip6->ip6_nxt; 914 int eoff = off + sizeof(struct icmp6_hdr) + 915 sizeof(struct ip6_hdr); 916 struct ip6ctlparam ip6cp; 917 struct in6_addr *finaldst = NULL; 918 int icmp6type = icmp6->icmp6_type; 919 struct ip6_frag *fh; 920 struct ip6_rthdr *rth; 921 struct ip6_rthdr0 *rth0; 922 int rthlen; 923 924 while (1) { /* XXX: should avoid infinite loop explicitly? */ 925 struct ip6_ext *eh; 926 927 switch (nxt) { 928 case IPPROTO_HOPOPTS: 929 case IPPROTO_DSTOPTS: 930 case IPPROTO_AH: 931 #ifndef PULLDOWN_TEST 932 IP6_EXTHDR_CHECK(m, 0, 933 eoff + sizeof(struct ip6_ext), -1); 934 eh = (struct ip6_ext *)(mtod(m, caddr_t) + eoff); 935 #else 936 IP6_EXTHDR_GET(eh, struct ip6_ext *, m, 937 eoff, sizeof(*eh)); 938 if (eh == NULL) { 939 ICMP6STAT_INC(icp6s_tooshort); 940 return (-1); 941 } 942 #endif 943 944 if (nxt == IPPROTO_AH) 945 eoff += (eh->ip6e_len + 2) << 2; 946 else 947 eoff += (eh->ip6e_len + 1) << 3; 948 nxt = eh->ip6e_nxt; 949 break; 950 case IPPROTO_ROUTING: 951 /* 952 * When the erroneous packet contains a 953 * routing header, we should examine the 954 * header to determine the final destination. 955 * Otherwise, we can't properly update 956 * information that depends on the final 957 * destination (e.g. path MTU). 958 */ 959 #ifndef PULLDOWN_TEST 960 IP6_EXTHDR_CHECK(m, 0, eoff + sizeof(*rth), -1); 961 rth = (struct ip6_rthdr *) 962 (mtod(m, caddr_t) + eoff); 963 #else 964 IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m, 965 eoff, sizeof(*rth)); 966 if (rth == NULL) { 967 ICMP6STAT_INC(icp6s_tooshort); 968 return (-1); 969 } 970 #endif 971 rthlen = (rth->ip6r_len + 1) << 3; 972 /* 973 * XXX: currently there is no 974 * officially defined type other 975 * than type-0. 976 * Note that if the segment left field 977 * is 0, all intermediate hops must 978 * have been passed. 979 */ 980 if (rth->ip6r_segleft && 981 rth->ip6r_type == IPV6_RTHDR_TYPE_0) { 982 int hops; 983 984 #ifndef PULLDOWN_TEST 985 IP6_EXTHDR_CHECK(m, 0, eoff + rthlen, -1); 986 rth0 = (struct ip6_rthdr0 *) 987 (mtod(m, caddr_t) + eoff); 988 #else 989 IP6_EXTHDR_GET(rth0, 990 struct ip6_rthdr0 *, m, 991 eoff, rthlen); 992 if (rth0 == NULL) { 993 ICMP6STAT_INC(icp6s_tooshort); 994 return (-1); 995 } 996 #endif 997 /* just ignore a bogus header */ 998 if ((rth0->ip6r0_len % 2) == 0 && 999 (hops = rth0->ip6r0_len/2)) 1000 finaldst = (struct in6_addr *)(rth0 + 1) + (hops - 1); 1001 } 1002 eoff += rthlen; 1003 nxt = rth->ip6r_nxt; 1004 break; 1005 case IPPROTO_FRAGMENT: 1006 #ifndef PULLDOWN_TEST 1007 IP6_EXTHDR_CHECK(m, 0, eoff + 1008 sizeof(struct ip6_frag), -1); 1009 fh = (struct ip6_frag *)(mtod(m, caddr_t) + 1010 eoff); 1011 #else 1012 IP6_EXTHDR_GET(fh, struct ip6_frag *, m, 1013 eoff, sizeof(*fh)); 1014 if (fh == NULL) { 1015 ICMP6STAT_INC(icp6s_tooshort); 1016 return (-1); 1017 } 1018 #endif 1019 /* 1020 * Data after a fragment header is meaningless 1021 * unless it is the first fragment, but 1022 * we'll go to the notify label for path MTU 1023 * discovery. 1024 */ 1025 if (fh->ip6f_offlg & IP6F_OFF_MASK) 1026 goto notify; 1027 1028 eoff += sizeof(struct ip6_frag); 1029 nxt = fh->ip6f_nxt; 1030 break; 1031 default: 1032 /* 1033 * This case includes ESP and the No Next 1034 * Header. In such cases going to the notify 1035 * label does not have any meaning 1036 * (i.e. ctlfunc will be NULL), but we go 1037 * anyway since we might have to update 1038 * path MTU information. 1039 */ 1040 goto notify; 1041 } 1042 } 1043 notify: 1044 #ifndef PULLDOWN_TEST 1045 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 1046 #else 1047 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, 1048 sizeof(*icmp6) + sizeof(struct ip6_hdr)); 1049 if (icmp6 == NULL) { 1050 ICMP6STAT_INC(icp6s_tooshort); 1051 return (-1); 1052 } 1053 #endif 1054 1055 /* 1056 * retrieve parameters from the inner IPv6 header, and convert 1057 * them into sockaddr structures. 1058 * XXX: there is no guarantee that the source or destination 1059 * addresses of the inner packet are in the same scope as 1060 * the addresses of the icmp packet. But there is no other 1061 * way to determine the zone. 1062 */ 1063 eip6 = (struct ip6_hdr *)(icmp6 + 1); 1064 1065 bzero(&icmp6dst, sizeof(icmp6dst)); 1066 icmp6dst.sin6_len = sizeof(struct sockaddr_in6); 1067 icmp6dst.sin6_family = AF_INET6; 1068 if (finaldst == NULL) 1069 icmp6dst.sin6_addr = eip6->ip6_dst; 1070 else 1071 icmp6dst.sin6_addr = *finaldst; 1072 if (in6_setscope(&icmp6dst.sin6_addr, m->m_pkthdr.rcvif, NULL)) 1073 goto freeit; 1074 bzero(&icmp6src, sizeof(icmp6src)); 1075 icmp6src.sin6_len = sizeof(struct sockaddr_in6); 1076 icmp6src.sin6_family = AF_INET6; 1077 icmp6src.sin6_addr = eip6->ip6_src; 1078 if (in6_setscope(&icmp6src.sin6_addr, m->m_pkthdr.rcvif, NULL)) 1079 goto freeit; 1080 icmp6src.sin6_flowinfo = 1081 (eip6->ip6_flow & IPV6_FLOWLABEL_MASK); 1082 1083 if (finaldst == NULL) 1084 finaldst = &eip6->ip6_dst; 1085 ip6cp.ip6c_m = m; 1086 ip6cp.ip6c_icmp6 = icmp6; 1087 ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1); 1088 ip6cp.ip6c_off = eoff; 1089 ip6cp.ip6c_finaldst = finaldst; 1090 ip6cp.ip6c_src = &icmp6src; 1091 ip6cp.ip6c_nxt = nxt; 1092 1093 if (icmp6type == ICMP6_PACKET_TOO_BIG) { 1094 notifymtu = ntohl(icmp6->icmp6_mtu); 1095 ip6cp.ip6c_cmdarg = (void *)¬ifymtu; 1096 icmp6_mtudisc_update(&ip6cp, 1); /*XXX*/ 1097 } 1098 1099 ctlfunc = (void (*)(int, struct sockaddr *, void *)) 1100 (inet6sw[ip6_protox[nxt]].pr_ctlinput); 1101 if (ctlfunc) { 1102 (void) (*ctlfunc)(code, (struct sockaddr *)&icmp6dst, 1103 &ip6cp); 1104 } 1105 } 1106 *mp = m; 1107 return (0); 1108 1109 freeit: 1110 m_freem(m); 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; 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 1123 #if 0 1124 /* 1125 * RFC2460 section 5, last paragraph. 1126 * even though minimum link MTU for IPv6 is IPV6_MMTU, 1127 * we may see ICMPv6 too big with mtu < IPV6_MMTU 1128 * due to packet translator in the middle. 1129 * see ip6_output() and ip6_getpmtu() "alwaysfrag" case for 1130 * special handling. 1131 */ 1132 if (mtu < IPV6_MMTU) 1133 return; 1134 #endif 1135 1136 /* 1137 * we reject ICMPv6 too big with abnormally small value. 1138 * XXX what is the good definition of "abnormally small"? 1139 */ 1140 if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8) 1141 return; 1142 1143 if (!validated) 1144 return; 1145 1146 /* 1147 * In case the suggested mtu is less than IPV6_MMTU, we 1148 * only need to remember that it was for above mentioned 1149 * "alwaysfrag" case. 1150 * Try to be as close to the spec as possible. 1151 */ 1152 if (mtu < IPV6_MMTU) 1153 mtu = IPV6_MMTU - 8; 1154 1155 bzero(&inc, sizeof(inc)); 1156 inc.inc_fibnum = M_GETFIB(m); 1157 inc.inc_flags |= INC_ISIPV6; 1158 inc.inc6_faddr = *dst; 1159 if (in6_setscope(&inc.inc6_faddr, m->m_pkthdr.rcvif, NULL)) 1160 return; 1161 1162 if (mtu < tcp_maxmtu6(&inc, NULL)) { 1163 tcp_hc_updatemtu(&inc, mtu); 1164 ICMP6STAT_INC(icp6s_pmtuchg); 1165 } 1166 } 1167 1168 /* 1169 * Process a Node Information Query packet, based on 1170 * draft-ietf-ipngwg-icmp-name-lookups-07. 1171 * 1172 * Spec incompatibilities: 1173 * - IPv6 Subject address handling 1174 * - IPv4 Subject address handling support missing 1175 * - Proxy reply (answer even if it's not for me) 1176 * - joins NI group address at in6_ifattach() time only, does not cope 1177 * with hostname changes by sethostname(3) 1178 */ 1179 static struct mbuf * 1180 ni6_input(struct mbuf *m, int off) 1181 { 1182 struct icmp6_nodeinfo *ni6, *nni6; 1183 struct mbuf *n = NULL; 1184 struct prison *pr; 1185 u_int16_t qtype; 1186 int subjlen; 1187 int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); 1188 struct ni_reply_fqdn *fqdn; 1189 int addrs; /* for NI_QTYPE_NODEADDR */ 1190 struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */ 1191 struct in6_addr in6_subj; /* subject address */ 1192 struct ip6_hdr *ip6; 1193 int oldfqdn = 0; /* if 1, return pascal string (03 draft) */ 1194 char *subj = NULL; 1195 struct in6_ifaddr *ia6 = NULL; 1196 1197 ip6 = mtod(m, struct ip6_hdr *); 1198 #ifndef PULLDOWN_TEST 1199 ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off); 1200 #else 1201 IP6_EXTHDR_GET(ni6, struct icmp6_nodeinfo *, m, off, sizeof(*ni6)); 1202 if (ni6 == NULL) { 1203 /* m is already reclaimed */ 1204 return (NULL); 1205 } 1206 #endif 1207 1208 /* 1209 * Validate IPv6 source address. 1210 * The default configuration MUST be to refuse answering queries from 1211 * global-scope addresses according to RFC4602. 1212 * Notes: 1213 * - it's not very clear what "refuse" means; this implementation 1214 * simply drops it. 1215 * - it's not very easy to identify global-scope (unicast) addresses 1216 * since there are many prefixes for them. It should be safer 1217 * and in practice sufficient to check "all" but loopback and 1218 * link-local (note that site-local unicast was deprecated and 1219 * ULA is defined as global scope-wise) 1220 */ 1221 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_GLOBALOK) == 0 && 1222 !IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) && 1223 !IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) 1224 goto bad; 1225 1226 /* 1227 * Validate IPv6 destination address. 1228 * 1229 * The Responder must discard the Query without further processing 1230 * unless it is one of the Responder's unicast or anycast addresses, or 1231 * a link-local scope multicast address which the Responder has joined. 1232 * [RFC4602, Section 5.] 1233 */ 1234 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 1235 if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst)) 1236 goto bad; 1237 /* else it's a link-local multicast, fine */ 1238 } else { /* unicast or anycast */ 1239 ia6 = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */); 1240 if (ia6 == NULL) 1241 goto bad; /* XXX impossible */ 1242 1243 if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) && 1244 !(V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK)) { 1245 ifa_free(&ia6->ia_ifa); 1246 nd6log((LOG_DEBUG, "ni6_input: ignore node info to " 1247 "a temporary address in %s:%d", 1248 __FILE__, __LINE__)); 1249 goto bad; 1250 } 1251 ifa_free(&ia6->ia_ifa); 1252 } 1253 1254 /* validate query Subject field. */ 1255 qtype = ntohs(ni6->ni_qtype); 1256 subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo); 1257 switch (qtype) { 1258 case NI_QTYPE_NOOP: 1259 case NI_QTYPE_SUPTYPES: 1260 /* 07 draft */ 1261 if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0) 1262 break; 1263 /* FALLTHROUGH */ 1264 case NI_QTYPE_FQDN: 1265 case NI_QTYPE_NODEADDR: 1266 case NI_QTYPE_IPV4ADDR: 1267 switch (ni6->ni_code) { 1268 case ICMP6_NI_SUBJ_IPV6: 1269 #if ICMP6_NI_SUBJ_IPV6 != 0 1270 case 0: 1271 #endif 1272 /* 1273 * backward compatibility - try to accept 03 draft 1274 * format, where no Subject is present. 1275 */ 1276 if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 && 1277 subjlen == 0) { 1278 oldfqdn++; 1279 break; 1280 } 1281 #if ICMP6_NI_SUBJ_IPV6 != 0 1282 if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6) 1283 goto bad; 1284 #endif 1285 1286 if (subjlen != sizeof(struct in6_addr)) 1287 goto bad; 1288 1289 /* 1290 * Validate Subject address. 1291 * 1292 * Not sure what exactly "address belongs to the node" 1293 * means in the spec, is it just unicast, or what? 1294 * 1295 * At this moment we consider Subject address as 1296 * "belong to the node" if the Subject address equals 1297 * to the IPv6 destination address; validation for 1298 * IPv6 destination address should have done enough 1299 * check for us. 1300 * 1301 * We do not do proxy at this moment. 1302 */ 1303 /* m_pulldown instead of copy? */ 1304 m_copydata(m, off + sizeof(struct icmp6_nodeinfo), 1305 subjlen, (caddr_t)&in6_subj); 1306 if (in6_setscope(&in6_subj, m->m_pkthdr.rcvif, NULL)) 1307 goto bad; 1308 1309 subj = (char *)&in6_subj; 1310 if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &in6_subj)) 1311 break; 1312 1313 /* 1314 * XXX if we are to allow other cases, we should really 1315 * be careful about scope here. 1316 * basically, we should disallow queries toward IPv6 1317 * destination X with subject Y, 1318 * if scope(X) > scope(Y). 1319 * if we allow scope(X) > scope(Y), it will result in 1320 * information leakage across scope boundary. 1321 */ 1322 goto bad; 1323 1324 case ICMP6_NI_SUBJ_FQDN: 1325 /* 1326 * Validate Subject name with gethostname(3). 1327 * 1328 * The behavior may need some debate, since: 1329 * - we are not sure if the node has FQDN as 1330 * hostname (returned by gethostname(3)). 1331 * - the code does wildcard match for truncated names. 1332 * however, we are not sure if we want to perform 1333 * wildcard match, if gethostname(3) side has 1334 * truncated hostname. 1335 */ 1336 pr = curthread->td_ucred->cr_prison; 1337 mtx_lock(&pr->pr_mtx); 1338 n = ni6_nametodns(pr->pr_hostname, 1339 strlen(pr->pr_hostname), 0); 1340 mtx_unlock(&pr->pr_mtx); 1341 if (!n || n->m_next || n->m_len == 0) 1342 goto bad; 1343 IP6_EXTHDR_GET(subj, char *, m, 1344 off + sizeof(struct icmp6_nodeinfo), subjlen); 1345 if (subj == NULL) 1346 goto bad; 1347 if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *), 1348 n->m_len)) { 1349 goto bad; 1350 } 1351 m_freem(n); 1352 n = NULL; 1353 break; 1354 1355 case ICMP6_NI_SUBJ_IPV4: /* XXX: to be implemented? */ 1356 default: 1357 goto bad; 1358 } 1359 break; 1360 } 1361 1362 /* refuse based on configuration. XXX ICMP6_NI_REFUSED? */ 1363 switch (qtype) { 1364 case NI_QTYPE_FQDN: 1365 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_FQDNOK) == 0) 1366 goto bad; 1367 break; 1368 case NI_QTYPE_NODEADDR: 1369 case NI_QTYPE_IPV4ADDR: 1370 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_NODEADDROK) == 0) 1371 goto bad; 1372 break; 1373 } 1374 1375 /* guess reply length */ 1376 switch (qtype) { 1377 case NI_QTYPE_NOOP: 1378 break; /* no reply data */ 1379 case NI_QTYPE_SUPTYPES: 1380 replylen += sizeof(u_int32_t); 1381 break; 1382 case NI_QTYPE_FQDN: 1383 /* XXX will append an mbuf */ 1384 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); 1385 break; 1386 case NI_QTYPE_NODEADDR: 1387 addrs = ni6_addrs(ni6, m, &ifp, (struct in6_addr *)subj); 1388 if ((replylen += addrs * (sizeof(struct in6_addr) + 1389 sizeof(u_int32_t))) > MCLBYTES) 1390 replylen = MCLBYTES; /* XXX: will truncate pkt later */ 1391 break; 1392 case NI_QTYPE_IPV4ADDR: 1393 /* unsupported - should respond with unknown Qtype? */ 1394 break; 1395 default: 1396 /* 1397 * XXX: We must return a reply with the ICMP6 code 1398 * `unknown Qtype' in this case. However we regard the case 1399 * as an FQDN query for backward compatibility. 1400 * Older versions set a random value to this field, 1401 * so it rarely varies in the defined qtypes. 1402 * But the mechanism is not reliable... 1403 * maybe we should obsolete older versions. 1404 */ 1405 qtype = NI_QTYPE_FQDN; 1406 /* XXX will append an mbuf */ 1407 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); 1408 oldfqdn++; 1409 break; 1410 } 1411 1412 /* Allocate an mbuf to reply. */ 1413 if (replylen > MCLBYTES) { 1414 /* 1415 * XXX: should we try to allocate more? But MCLBYTES 1416 * is probably much larger than IPV6_MMTU... 1417 */ 1418 goto bad; 1419 } 1420 if (replylen > MHLEN) 1421 n = m_getcl(M_NOWAIT, m->m_type, M_PKTHDR); 1422 else 1423 n = m_gethdr(M_NOWAIT, m->m_type); 1424 if (n == NULL) { 1425 m_freem(m); 1426 return (NULL); 1427 } 1428 m_move_pkthdr(n, m); /* just for recvif and FIB */ 1429 n->m_pkthdr.len = n->m_len = replylen; 1430 1431 /* copy mbuf header and IPv6 + Node Information base headers */ 1432 bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr)); 1433 nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1); 1434 bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo)); 1435 1436 /* qtype dependent procedure */ 1437 switch (qtype) { 1438 case NI_QTYPE_NOOP: 1439 nni6->ni_code = ICMP6_NI_SUCCESS; 1440 nni6->ni_flags = 0; 1441 break; 1442 case NI_QTYPE_SUPTYPES: 1443 { 1444 u_int32_t v; 1445 nni6->ni_code = ICMP6_NI_SUCCESS; 1446 nni6->ni_flags = htons(0x0000); /* raw bitmap */ 1447 /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */ 1448 v = (u_int32_t)htonl(0x0000000f); 1449 bcopy(&v, nni6 + 1, sizeof(u_int32_t)); 1450 break; 1451 } 1452 case NI_QTYPE_FQDN: 1453 nni6->ni_code = ICMP6_NI_SUCCESS; 1454 fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) + 1455 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo)); 1456 nni6->ni_flags = 0; /* XXX: meaningless TTL */ 1457 fqdn->ni_fqdn_ttl = 0; /* ditto. */ 1458 /* 1459 * XXX do we really have FQDN in hostname? 1460 */ 1461 pr = curthread->td_ucred->cr_prison; 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 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) { 1675 switch (ni6->ni_code) { 1676 case ICMP6_NI_SUBJ_IPV6: 1677 if (subj == NULL) /* must be impossible... */ 1678 return (0); 1679 break; 1680 default: 1681 /* 1682 * XXX: we only support IPv6 subject address for 1683 * this Qtype. 1684 */ 1685 return (0); 1686 } 1687 } 1688 1689 IFNET_RLOCK_NOSLEEP(); 1690 TAILQ_FOREACH(ifp, &V_ifnet, if_link) { 1691 addrsofif = 0; 1692 IF_ADDR_RLOCK(ifp); 1693 TAILQ_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_ADDR_RUNLOCK(ifp); 1744 if (iffound) { 1745 *ifpp = ifp; 1746 IFNET_RUNLOCK_NOSLEEP(); 1747 return (addrsofif); 1748 } 1749 1750 addrs += addrsofif; 1751 } 1752 IFNET_RUNLOCK_NOSLEEP(); 1753 1754 return (addrs); 1755 } 1756 1757 static int 1758 ni6_store_addrs(struct icmp6_nodeinfo *ni6, struct icmp6_nodeinfo *nni6, 1759 struct ifnet *ifp0, int resid) 1760 { 1761 struct ifnet *ifp; 1762 struct in6_ifaddr *ifa6; 1763 struct ifaddr *ifa; 1764 struct ifnet *ifp_dep = NULL; 1765 int copied = 0, allow_deprecated = 0; 1766 u_char *cp = (u_char *)(nni6 + 1); 1767 int niflags = ni6->ni_flags; 1768 u_int32_t ltime; 1769 1770 if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL)) 1771 return (0); /* needless to copy */ 1772 1773 IFNET_RLOCK_NOSLEEP(); 1774 ifp = ifp0 ? ifp0 : TAILQ_FIRST(&V_ifnet); 1775 again: 1776 1777 for (; ifp; ifp = TAILQ_NEXT(ifp, if_link)) { 1778 IF_ADDR_RLOCK(ifp); 1779 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 1780 if (ifa->ifa_addr->sa_family != AF_INET6) 1781 continue; 1782 ifa6 = (struct in6_ifaddr *)ifa; 1783 1784 if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 && 1785 allow_deprecated == 0) { 1786 /* 1787 * prefererred address should be put before 1788 * deprecated addresses. 1789 */ 1790 1791 /* record the interface for later search */ 1792 if (ifp_dep == NULL) 1793 ifp_dep = ifp; 1794 1795 continue; 1796 } else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 && 1797 allow_deprecated != 0) 1798 continue; /* we now collect deprecated addrs */ 1799 1800 /* What do we have to do about ::1? */ 1801 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { 1802 case IPV6_ADDR_SCOPE_LINKLOCAL: 1803 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) 1804 continue; 1805 break; 1806 case IPV6_ADDR_SCOPE_SITELOCAL: 1807 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) 1808 continue; 1809 break; 1810 case IPV6_ADDR_SCOPE_GLOBAL: 1811 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) 1812 continue; 1813 break; 1814 default: 1815 continue; 1816 } 1817 1818 /* 1819 * check if anycast is okay. 1820 * XXX: just experimental. not in the spec. 1821 */ 1822 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && 1823 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) 1824 continue; 1825 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && 1826 (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) { 1827 continue; 1828 } 1829 1830 /* now we can copy the address */ 1831 if (resid < sizeof(struct in6_addr) + 1832 sizeof(u_int32_t)) { 1833 IF_ADDR_RUNLOCK(ifp); 1834 /* 1835 * We give up much more copy. 1836 * Set the truncate flag and return. 1837 */ 1838 nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE; 1839 IFNET_RUNLOCK_NOSLEEP(); 1840 return (copied); 1841 } 1842 1843 /* 1844 * Set the TTL of the address. 1845 * The TTL value should be one of the following 1846 * according to the specification: 1847 * 1848 * 1. The remaining lifetime of a DHCP lease on the 1849 * address, or 1850 * 2. The remaining Valid Lifetime of a prefix from 1851 * which the address was derived through Stateless 1852 * Autoconfiguration. 1853 * 1854 * Note that we currently do not support stateful 1855 * address configuration by DHCPv6, so the former 1856 * case can't happen. 1857 */ 1858 if (ifa6->ia6_lifetime.ia6t_expire == 0) 1859 ltime = ND6_INFINITE_LIFETIME; 1860 else { 1861 if (ifa6->ia6_lifetime.ia6t_expire > 1862 time_uptime) 1863 ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_uptime); 1864 else 1865 ltime = 0; 1866 } 1867 1868 bcopy(<ime, cp, sizeof(u_int32_t)); 1869 cp += sizeof(u_int32_t); 1870 1871 /* copy the address itself */ 1872 bcopy(&ifa6->ia_addr.sin6_addr, cp, 1873 sizeof(struct in6_addr)); 1874 in6_clearscope((struct in6_addr *)cp); /* XXX */ 1875 cp += sizeof(struct in6_addr); 1876 1877 resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t)); 1878 copied += (sizeof(struct in6_addr) + sizeof(u_int32_t)); 1879 } 1880 IF_ADDR_RUNLOCK(ifp); 1881 if (ifp0) /* we need search only on the specified IF */ 1882 break; 1883 } 1884 1885 if (allow_deprecated == 0 && ifp_dep != NULL) { 1886 ifp = ifp_dep; 1887 allow_deprecated = 1; 1888 1889 goto again; 1890 } 1891 1892 IFNET_RUNLOCK_NOSLEEP(); 1893 1894 return (copied); 1895 } 1896 1897 /* 1898 * XXX almost dup'ed code with rip6_input. 1899 */ 1900 static int 1901 icmp6_rip6_input(struct mbuf **mp, int off) 1902 { 1903 struct mbuf *m = *mp; 1904 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1905 struct inpcb *in6p; 1906 struct inpcb *last = NULL; 1907 struct sockaddr_in6 fromsa; 1908 struct icmp6_hdr *icmp6; 1909 struct mbuf *opts = NULL; 1910 1911 #ifndef PULLDOWN_TEST 1912 /* this is assumed to be safe. */ 1913 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off); 1914 #else 1915 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6)); 1916 if (icmp6 == NULL) { 1917 /* m is already reclaimed */ 1918 return (IPPROTO_DONE); 1919 } 1920 #endif 1921 1922 /* 1923 * XXX: the address may have embedded scope zone ID, which should be 1924 * hidden from applications. 1925 */ 1926 bzero(&fromsa, sizeof(fromsa)); 1927 fromsa.sin6_family = AF_INET6; 1928 fromsa.sin6_len = sizeof(struct sockaddr_in6); 1929 fromsa.sin6_addr = ip6->ip6_src; 1930 if (sa6_recoverscope(&fromsa)) { 1931 m_freem(m); 1932 return (IPPROTO_DONE); 1933 } 1934 1935 INP_INFO_RLOCK(&V_ripcbinfo); 1936 LIST_FOREACH(in6p, &V_ripcb, inp_list) { 1937 if ((in6p->inp_vflag & INP_IPV6) == 0) 1938 continue; 1939 if (in6p->inp_ip_p != IPPROTO_ICMPV6) 1940 continue; 1941 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) && 1942 !IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &ip6->ip6_dst)) 1943 continue; 1944 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr) && 1945 !IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src)) 1946 continue; 1947 INP_RLOCK(in6p); 1948 if (ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type, 1949 in6p->in6p_icmp6filt)) { 1950 INP_RUNLOCK(in6p); 1951 continue; 1952 } 1953 if (last != NULL) { 1954 struct mbuf *n = NULL; 1955 1956 /* 1957 * Recent network drivers tend to allocate a single 1958 * mbuf cluster, rather than to make a couple of 1959 * mbufs without clusters. Also, since the IPv6 code 1960 * path tries to avoid m_pullup(), it is highly 1961 * probable that we still have an mbuf cluster here 1962 * even though the necessary length can be stored in an 1963 * mbuf's internal buffer. 1964 * Meanwhile, the default size of the receive socket 1965 * buffer for raw sockets is not so large. This means 1966 * the possibility of packet loss is relatively higher 1967 * than before. To avoid this scenario, we copy the 1968 * received data to a separate mbuf that does not use 1969 * a cluster, if possible. 1970 * XXX: it is better to copy the data after stripping 1971 * intermediate headers. 1972 */ 1973 if ((m->m_flags & M_EXT) && m->m_next == NULL && 1974 m->m_len <= MHLEN) { 1975 n = m_get(M_NOWAIT, m->m_type); 1976 if (n != NULL) { 1977 if (m_dup_pkthdr(n, m, M_NOWAIT)) { 1978 bcopy(m->m_data, n->m_data, 1979 m->m_len); 1980 n->m_len = m->m_len; 1981 } else { 1982 m_free(n); 1983 n = NULL; 1984 } 1985 } 1986 } 1987 if (n != NULL || 1988 (n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) != NULL) { 1989 if (last->inp_flags & INP_CONTROLOPTS) 1990 ip6_savecontrol(last, n, &opts); 1991 /* strip intermediate headers */ 1992 m_adj(n, off); 1993 SOCKBUF_LOCK(&last->inp_socket->so_rcv); 1994 if (sbappendaddr_locked( 1995 &last->inp_socket->so_rcv, 1996 (struct sockaddr *)&fromsa, n, opts) 1997 == 0) { 1998 /* should notify about lost packet */ 1999 m_freem(n); 2000 if (opts) { 2001 m_freem(opts); 2002 } 2003 SOCKBUF_UNLOCK( 2004 &last->inp_socket->so_rcv); 2005 } else 2006 sorwakeup_locked(last->inp_socket); 2007 opts = NULL; 2008 } 2009 INP_RUNLOCK(last); 2010 } 2011 last = in6p; 2012 } 2013 INP_INFO_RUNLOCK(&V_ripcbinfo); 2014 if (last != NULL) { 2015 if (last->inp_flags & INP_CONTROLOPTS) 2016 ip6_savecontrol(last, m, &opts); 2017 /* strip intermediate headers */ 2018 m_adj(m, off); 2019 2020 /* avoid using mbuf clusters if possible (see above) */ 2021 if ((m->m_flags & M_EXT) && m->m_next == NULL && 2022 m->m_len <= MHLEN) { 2023 struct mbuf *n; 2024 2025 n = m_get(M_NOWAIT, m->m_type); 2026 if (n != NULL) { 2027 if (m_dup_pkthdr(n, m, M_NOWAIT)) { 2028 bcopy(m->m_data, n->m_data, m->m_len); 2029 n->m_len = m->m_len; 2030 2031 m_freem(m); 2032 m = n; 2033 } else { 2034 m_freem(n); 2035 n = NULL; 2036 } 2037 } 2038 } 2039 SOCKBUF_LOCK(&last->inp_socket->so_rcv); 2040 if (sbappendaddr_locked(&last->inp_socket->so_rcv, 2041 (struct sockaddr *)&fromsa, m, opts) == 0) { 2042 m_freem(m); 2043 if (opts) 2044 m_freem(opts); 2045 SOCKBUF_UNLOCK(&last->inp_socket->so_rcv); 2046 } else 2047 sorwakeup_locked(last->inp_socket); 2048 INP_RUNLOCK(last); 2049 } else { 2050 m_freem(m); 2051 IP6STAT_DEC(ip6s_delivered); 2052 } 2053 return IPPROTO_DONE; 2054 } 2055 2056 /* 2057 * Reflect the ip6 packet back to the source. 2058 * OFF points to the icmp6 header, counted from the top of the mbuf. 2059 */ 2060 void 2061 icmp6_reflect(struct mbuf *m, size_t off) 2062 { 2063 struct in6_addr src6, *srcp; 2064 struct ip6_hdr *ip6; 2065 struct icmp6_hdr *icmp6; 2066 struct in6_ifaddr *ia = NULL; 2067 struct ifnet *outif = NULL; 2068 int plen; 2069 int type, code, hlim; 2070 2071 /* too short to reflect */ 2072 if (off < sizeof(struct ip6_hdr)) { 2073 nd6log((LOG_DEBUG, 2074 "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n", 2075 (u_long)off, (u_long)sizeof(struct ip6_hdr), 2076 __FILE__, __LINE__)); 2077 goto bad; 2078 } 2079 2080 /* 2081 * If there are extra headers between IPv6 and ICMPv6, strip 2082 * off that header first. 2083 */ 2084 #ifdef DIAGNOSTIC 2085 if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN) 2086 panic("assumption failed in icmp6_reflect"); 2087 #endif 2088 if (off > sizeof(struct ip6_hdr)) { 2089 size_t l; 2090 struct ip6_hdr nip6; 2091 2092 l = off - sizeof(struct ip6_hdr); 2093 m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6); 2094 m_adj(m, 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 bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6)); 2101 } else /* off == sizeof(struct ip6_hdr) */ { 2102 size_t l; 2103 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 2104 if (m->m_len < l) { 2105 if ((m = m_pullup(m, l)) == NULL) 2106 return; 2107 } 2108 } 2109 plen = m->m_pkthdr.len - sizeof(struct ip6_hdr); 2110 ip6 = mtod(m, struct ip6_hdr *); 2111 ip6->ip6_nxt = IPPROTO_ICMPV6; 2112 icmp6 = (struct icmp6_hdr *)(ip6 + 1); 2113 type = icmp6->icmp6_type; /* keep type for statistics */ 2114 code = icmp6->icmp6_code; /* ditto. */ 2115 hlim = 0; 2116 srcp = NULL; 2117 2118 /* 2119 * If the incoming packet was addressed directly to us (i.e. unicast), 2120 * use dst as the src for the reply. 2121 * The IN6_IFF_NOTREADY case should be VERY rare, but is possible 2122 * (for example) when we encounter an error while forwarding procedure 2123 * destined to a duplicated address of ours. 2124 */ 2125 if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 2126 ia = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */); 2127 if (ia != NULL && !(ia->ia6_flags & 2128 (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) { 2129 src6 = ia->ia_addr.sin6_addr; 2130 srcp = &src6; 2131 2132 if (m->m_pkthdr.rcvif != NULL) { 2133 /* XXX: This may not be the outgoing interface */ 2134 hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim; 2135 } else 2136 hlim = V_ip6_defhlim; 2137 } 2138 if (ia != NULL) 2139 ifa_free(&ia->ia_ifa); 2140 } 2141 2142 if (srcp == NULL) { 2143 int error; 2144 struct in6_addr dst6; 2145 uint32_t scopeid; 2146 2147 /* 2148 * This case matches to multicasts, our anycast, or unicasts 2149 * that we do not own. Select a source address based on the 2150 * source address of the erroneous packet. 2151 */ 2152 in6_splitscope(&ip6->ip6_src, &dst6, &scopeid); 2153 error = in6_selectsrc_addr(M_GETFIB(m), &dst6, 2154 scopeid, NULL, &src6, &hlim); 2155 2156 if (error) { 2157 char ip6buf[INET6_ADDRSTRLEN]; 2158 nd6log((LOG_DEBUG, 2159 "icmp6_reflect: source can't be determined: " 2160 "dst=%s, error=%d\n", 2161 ip6_sprintf(ip6buf, &ip6->ip6_dst), error)); 2162 goto bad; 2163 } 2164 srcp = &src6; 2165 } 2166 /* 2167 * ip6_input() drops a packet if its src is multicast. 2168 * So, the src is never multicast. 2169 */ 2170 ip6->ip6_dst = ip6->ip6_src; 2171 ip6->ip6_src = *srcp; 2172 ip6->ip6_flow = 0; 2173 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2174 ip6->ip6_vfc |= IPV6_VERSION; 2175 ip6->ip6_nxt = IPPROTO_ICMPV6; 2176 ip6->ip6_hlim = hlim; 2177 2178 icmp6->icmp6_cksum = 0; 2179 icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2180 sizeof(struct ip6_hdr), plen); 2181 2182 /* 2183 * XXX option handling 2184 */ 2185 2186 m->m_flags &= ~(M_BCAST|M_MCAST); 2187 2188 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2189 if (outif) 2190 icmp6_ifoutstat_inc(outif, type, code); 2191 2192 return; 2193 2194 bad: 2195 m_freem(m); 2196 return; 2197 } 2198 2199 void 2200 icmp6_fasttimo(void) 2201 { 2202 2203 mld_fasttimo(); 2204 } 2205 2206 void 2207 icmp6_slowtimo(void) 2208 { 2209 2210 mld_slowtimo(); 2211 } 2212 2213 static const char * 2214 icmp6_redirect_diag(struct in6_addr *src6, struct in6_addr *dst6, 2215 struct in6_addr *tgt6) 2216 { 2217 static char buf[1024]; 2218 char ip6bufs[INET6_ADDRSTRLEN]; 2219 char ip6bufd[INET6_ADDRSTRLEN]; 2220 char ip6buft[INET6_ADDRSTRLEN]; 2221 snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)", 2222 ip6_sprintf(ip6bufs, src6), ip6_sprintf(ip6bufd, dst6), 2223 ip6_sprintf(ip6buft, tgt6)); 2224 return buf; 2225 } 2226 2227 void 2228 icmp6_redirect_input(struct mbuf *m, int off) 2229 { 2230 struct ifnet *ifp; 2231 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 2232 struct nd_redirect *nd_rd; 2233 int icmp6len = ntohs(ip6->ip6_plen); 2234 char *lladdr = NULL; 2235 int lladdrlen = 0; 2236 int is_router; 2237 int is_onlink; 2238 struct in6_addr src6 = ip6->ip6_src; 2239 struct in6_addr redtgt6; 2240 struct in6_addr reddst6; 2241 union nd_opts ndopts; 2242 char ip6buf[INET6_ADDRSTRLEN]; 2243 2244 M_ASSERTPKTHDR(m); 2245 KASSERT(m->m_pkthdr.rcvif != NULL, ("%s: no rcvif", __func__)); 2246 2247 ifp = m->m_pkthdr.rcvif; 2248 2249 /* XXX if we are router, we don't update route by icmp6 redirect */ 2250 if (V_ip6_forwarding) 2251 goto freeit; 2252 if (!V_icmp6_rediraccept) 2253 goto freeit; 2254 2255 /* RFC 6980: Nodes MUST silently ignore fragments */ 2256 if(m->m_flags & M_FRAGMENTED) 2257 goto freeit; 2258 2259 #ifndef PULLDOWN_TEST 2260 IP6_EXTHDR_CHECK(m, off, icmp6len,); 2261 nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off); 2262 #else 2263 IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len); 2264 if (nd_rd == NULL) { 2265 ICMP6STAT_INC(icp6s_tooshort); 2266 return; 2267 } 2268 #endif 2269 redtgt6 = nd_rd->nd_rd_target; 2270 reddst6 = nd_rd->nd_rd_dst; 2271 2272 if (in6_setscope(&redtgt6, m->m_pkthdr.rcvif, NULL) || 2273 in6_setscope(&reddst6, m->m_pkthdr.rcvif, NULL)) { 2274 goto freeit; 2275 } 2276 2277 /* validation */ 2278 if (!IN6_IS_ADDR_LINKLOCAL(&src6)) { 2279 nd6log((LOG_ERR, 2280 "ICMP6 redirect sent from %s rejected; " 2281 "must be from linklocal\n", 2282 ip6_sprintf(ip6buf, &src6))); 2283 goto bad; 2284 } 2285 if (ip6->ip6_hlim != 255) { 2286 nd6log((LOG_ERR, 2287 "ICMP6 redirect sent from %s rejected; " 2288 "hlim=%d (must be 255)\n", 2289 ip6_sprintf(ip6buf, &src6), ip6->ip6_hlim)); 2290 goto bad; 2291 } 2292 { 2293 /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */ 2294 struct nhop6_basic nh6; 2295 struct in6_addr kdst; 2296 uint32_t scopeid; 2297 2298 in6_splitscope(&reddst6, &kdst, &scopeid); 2299 if (fib6_lookup_nh_basic(ifp->if_fib, &kdst, scopeid, 0, 0,&nh6)==0){ 2300 if ((nh6.nh_flags & NHF_GATEWAY) == 0) { 2301 nd6log((LOG_ERR, 2302 "ICMP6 redirect rejected; no route " 2303 "with inet6 gateway found for redirect dst: %s\n", 2304 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2305 goto bad; 2306 } 2307 2308 /* 2309 * Embed scope zone id into next hop address, since 2310 * fib6_lookup_nh_basic() returns address without embedded 2311 * scope zone id. 2312 */ 2313 if (in6_setscope(&nh6.nh_addr, m->m_pkthdr.rcvif, NULL)) 2314 goto freeit; 2315 2316 if (IN6_ARE_ADDR_EQUAL(&src6, &nh6.nh_addr) == 0) { 2317 nd6log((LOG_ERR, 2318 "ICMP6 redirect rejected; " 2319 "not equal to gw-for-src=%s (must be same): " 2320 "%s\n", 2321 ip6_sprintf(ip6buf, &nh6.nh_addr), 2322 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2323 goto bad; 2324 } 2325 } else { 2326 nd6log((LOG_ERR, 2327 "ICMP6 redirect rejected; " 2328 "no route found for redirect dst: %s\n", 2329 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2330 goto bad; 2331 } 2332 } 2333 if (IN6_IS_ADDR_MULTICAST(&reddst6)) { 2334 nd6log((LOG_ERR, 2335 "ICMP6 redirect rejected; " 2336 "redirect dst must be unicast: %s\n", 2337 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2338 goto bad; 2339 } 2340 2341 is_router = is_onlink = 0; 2342 if (IN6_IS_ADDR_LINKLOCAL(&redtgt6)) 2343 is_router = 1; /* router case */ 2344 if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0) 2345 is_onlink = 1; /* on-link destination case */ 2346 if (!is_router && !is_onlink) { 2347 nd6log((LOG_ERR, 2348 "ICMP6 redirect rejected; " 2349 "neither router case nor onlink case: %s\n", 2350 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2351 goto bad; 2352 } 2353 2354 icmp6len -= sizeof(*nd_rd); 2355 nd6_option_init(nd_rd + 1, icmp6len, &ndopts); 2356 if (nd6_options(&ndopts) < 0) { 2357 nd6log((LOG_INFO, "%s: invalid ND option, rejected: %s\n", 2358 __func__, icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2359 /* nd6_options have incremented stats */ 2360 goto freeit; 2361 } 2362 2363 if (ndopts.nd_opts_tgt_lladdr) { 2364 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 2365 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 2366 } 2367 2368 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 2369 nd6log((LOG_INFO, "%s: lladdrlen mismatch for %s " 2370 "(if %d, icmp6 packet %d): %s\n", 2371 __func__, ip6_sprintf(ip6buf, &redtgt6), 2372 ifp->if_addrlen, lladdrlen - 2, 2373 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2374 goto bad; 2375 } 2376 2377 /* Validation passed. */ 2378 2379 /* RFC 2461 8.3 */ 2380 nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT, 2381 is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER); 2382 2383 /* 2384 * Install a gateway route in the better-router case or an interface 2385 * route in the on-link-destination case. 2386 */ 2387 { 2388 struct sockaddr_in6 sdst; 2389 struct sockaddr_in6 sgw; 2390 struct sockaddr_in6 ssrc; 2391 struct sockaddr *gw; 2392 int rt_flags; 2393 u_int fibnum; 2394 2395 bzero(&sdst, sizeof(sdst)); 2396 bzero(&ssrc, sizeof(ssrc)); 2397 sdst.sin6_family = ssrc.sin6_family = AF_INET6; 2398 sdst.sin6_len = ssrc.sin6_len = sizeof(struct sockaddr_in6); 2399 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr)); 2400 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr)); 2401 rt_flags = RTF_HOST; 2402 if (is_router) { 2403 bzero(&sgw, sizeof(sgw)); 2404 sgw.sin6_family = AF_INET6; 2405 sgw.sin6_len = sizeof(struct sockaddr_in6); 2406 bcopy(&redtgt6, &sgw.sin6_addr, 2407 sizeof(struct in6_addr)); 2408 gw = (struct sockaddr *)&sgw; 2409 rt_flags |= RTF_GATEWAY; 2410 } else 2411 gw = ifp->if_addr->ifa_addr; 2412 for (fibnum = 0; fibnum < rt_numfibs; fibnum++) 2413 in6_rtredirect((struct sockaddr *)&sdst, gw, 2414 (struct sockaddr *)NULL, rt_flags, 2415 (struct sockaddr *)&ssrc, fibnum); 2416 } 2417 /* finally update cached route in each socket via pfctlinput */ 2418 { 2419 struct sockaddr_in6 sdst; 2420 2421 bzero(&sdst, sizeof(sdst)); 2422 sdst.sin6_family = AF_INET6; 2423 sdst.sin6_len = sizeof(struct sockaddr_in6); 2424 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr)); 2425 pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst); 2426 } 2427 2428 freeit: 2429 m_freem(m); 2430 return; 2431 2432 bad: 2433 ICMP6STAT_INC(icp6s_badredirect); 2434 m_freem(m); 2435 } 2436 2437 void 2438 icmp6_redirect_output(struct mbuf *m0, struct rtentry *rt) 2439 { 2440 struct ifnet *ifp; /* my outgoing interface */ 2441 struct in6_addr *ifp_ll6; 2442 struct in6_addr *router_ll6; 2443 struct ip6_hdr *sip6; /* m0 as struct ip6_hdr */ 2444 struct mbuf *m = NULL; /* newly allocated one */ 2445 struct m_tag *mtag; 2446 struct ip6_hdr *ip6; /* m as struct ip6_hdr */ 2447 struct nd_redirect *nd_rd; 2448 struct llentry *ln = NULL; 2449 size_t maxlen; 2450 u_char *p; 2451 struct ifnet *outif = NULL; 2452 struct sockaddr_in6 src_sa; 2453 2454 icmp6_errcount(ND_REDIRECT, 0); 2455 2456 /* if we are not router, we don't send icmp6 redirect */ 2457 if (!V_ip6_forwarding) 2458 goto fail; 2459 2460 /* sanity check */ 2461 if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp)) 2462 goto fail; 2463 2464 /* 2465 * Address check: 2466 * the source address must identify a neighbor, and 2467 * the destination address must not be a multicast address 2468 * [RFC 2461, sec 8.2] 2469 */ 2470 sip6 = mtod(m0, struct ip6_hdr *); 2471 bzero(&src_sa, sizeof(src_sa)); 2472 src_sa.sin6_family = AF_INET6; 2473 src_sa.sin6_len = sizeof(src_sa); 2474 src_sa.sin6_addr = sip6->ip6_src; 2475 if (nd6_is_addr_neighbor(&src_sa, ifp) == 0) 2476 goto fail; 2477 if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst)) 2478 goto fail; /* what should we do here? */ 2479 2480 /* rate limit */ 2481 if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0)) 2482 goto fail; 2483 2484 /* 2485 * Since we are going to append up to 1280 bytes (= IPV6_MMTU), 2486 * we almost always ask for an mbuf cluster for simplicity. 2487 * (MHLEN < IPV6_MMTU is almost always true) 2488 */ 2489 #if IPV6_MMTU >= MCLBYTES 2490 # error assumption failed about IPV6_MMTU and MCLBYTES 2491 #endif 2492 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 2493 if (m == NULL) 2494 goto fail; 2495 M_SETFIB(m, rt->rt_fibnum); 2496 maxlen = M_TRAILINGSPACE(m); 2497 maxlen = min(IPV6_MMTU, maxlen); 2498 /* just for safety */ 2499 if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) + 2500 ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) { 2501 goto fail; 2502 } 2503 2504 { 2505 /* get ip6 linklocal address for ifp(my outgoing interface). */ 2506 struct in6_ifaddr *ia; 2507 if ((ia = in6ifa_ifpforlinklocal(ifp, 2508 IN6_IFF_NOTREADY| 2509 IN6_IFF_ANYCAST)) == NULL) 2510 goto fail; 2511 ifp_ll6 = &ia->ia_addr.sin6_addr; 2512 /* XXXRW: reference released prematurely. */ 2513 ifa_free(&ia->ia_ifa); 2514 } 2515 2516 /* get ip6 linklocal address for the router. */ 2517 if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) { 2518 struct sockaddr_in6 *sin6; 2519 sin6 = (struct sockaddr_in6 *)rt->rt_gateway; 2520 router_ll6 = &sin6->sin6_addr; 2521 if (!IN6_IS_ADDR_LINKLOCAL(router_ll6)) 2522 router_ll6 = (struct in6_addr *)NULL; 2523 } else 2524 router_ll6 = (struct in6_addr *)NULL; 2525 2526 /* ip6 */ 2527 ip6 = mtod(m, struct ip6_hdr *); 2528 ip6->ip6_flow = 0; 2529 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2530 ip6->ip6_vfc |= IPV6_VERSION; 2531 /* ip6->ip6_plen will be set later */ 2532 ip6->ip6_nxt = IPPROTO_ICMPV6; 2533 ip6->ip6_hlim = 255; 2534 /* ip6->ip6_src must be linklocal addr for my outgoing if. */ 2535 bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr)); 2536 bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr)); 2537 2538 /* ND Redirect */ 2539 nd_rd = (struct nd_redirect *)(ip6 + 1); 2540 nd_rd->nd_rd_type = ND_REDIRECT; 2541 nd_rd->nd_rd_code = 0; 2542 nd_rd->nd_rd_reserved = 0; 2543 if (rt->rt_flags & RTF_GATEWAY) { 2544 /* 2545 * nd_rd->nd_rd_target must be a link-local address in 2546 * better router cases. 2547 */ 2548 if (!router_ll6) 2549 goto fail; 2550 bcopy(router_ll6, &nd_rd->nd_rd_target, 2551 sizeof(nd_rd->nd_rd_target)); 2552 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2553 sizeof(nd_rd->nd_rd_dst)); 2554 } else { 2555 /* make sure redtgt == reddst */ 2556 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target, 2557 sizeof(nd_rd->nd_rd_target)); 2558 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2559 sizeof(nd_rd->nd_rd_dst)); 2560 } 2561 2562 p = (u_char *)(nd_rd + 1); 2563 2564 if (!router_ll6) 2565 goto nolladdropt; 2566 2567 { 2568 /* target lladdr option */ 2569 int len; 2570 struct nd_opt_hdr *nd_opt; 2571 char *lladdr; 2572 2573 IF_AFDATA_RLOCK(ifp); 2574 ln = nd6_lookup(router_ll6, 0, ifp); 2575 IF_AFDATA_RUNLOCK(ifp); 2576 if (ln == NULL) 2577 goto nolladdropt; 2578 2579 len = sizeof(*nd_opt) + ifp->if_addrlen; 2580 len = (len + 7) & ~7; /* round by 8 */ 2581 /* safety check */ 2582 if (len + (p - (u_char *)ip6) > maxlen) 2583 goto nolladdropt; 2584 2585 if (ln->la_flags & LLE_VALID) { 2586 nd_opt = (struct nd_opt_hdr *)p; 2587 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 2588 nd_opt->nd_opt_len = len >> 3; 2589 lladdr = (char *)(nd_opt + 1); 2590 bcopy(ln->ll_addr, lladdr, ifp->if_addrlen); 2591 p += len; 2592 } 2593 } 2594 nolladdropt: 2595 if (ln != NULL) 2596 LLE_RUNLOCK(ln); 2597 2598 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2599 2600 /* just to be safe */ 2601 #ifdef M_DECRYPTED /*not openbsd*/ 2602 if (m0->m_flags & M_DECRYPTED) 2603 goto noredhdropt; 2604 #endif 2605 if (p - (u_char *)ip6 > maxlen) 2606 goto noredhdropt; 2607 2608 { 2609 /* redirected header option */ 2610 int len; 2611 struct nd_opt_rd_hdr *nd_opt_rh; 2612 2613 /* 2614 * compute the maximum size for icmp6 redirect header option. 2615 * XXX room for auth header? 2616 */ 2617 len = maxlen - (p - (u_char *)ip6); 2618 len &= ~7; 2619 2620 /* This is just for simplicity. */ 2621 if (m0->m_pkthdr.len != m0->m_len) { 2622 if (m0->m_next) { 2623 m_freem(m0->m_next); 2624 m0->m_next = NULL; 2625 } 2626 m0->m_pkthdr.len = m0->m_len; 2627 } 2628 2629 /* 2630 * Redirected header option spec (RFC2461 4.6.3) talks nothing 2631 * about padding/truncate rule for the original IP packet. 2632 * From the discussion on IPv6imp in Feb 1999, 2633 * the consensus was: 2634 * - "attach as much as possible" is the goal 2635 * - pad if not aligned (original size can be guessed by 2636 * original ip6 header) 2637 * Following code adds the padding if it is simple enough, 2638 * and truncates if not. 2639 */ 2640 if (m0->m_next || m0->m_pkthdr.len != m0->m_len) 2641 panic("assumption failed in %s:%d", __FILE__, 2642 __LINE__); 2643 2644 if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) { 2645 /* not enough room, truncate */ 2646 m0->m_pkthdr.len = m0->m_len = len - 2647 sizeof(*nd_opt_rh); 2648 } else { 2649 /* enough room, pad or truncate */ 2650 size_t extra; 2651 2652 extra = m0->m_pkthdr.len % 8; 2653 if (extra) { 2654 /* pad if easy enough, truncate if not */ 2655 if (8 - extra <= M_TRAILINGSPACE(m0)) { 2656 /* pad */ 2657 m0->m_len += (8 - extra); 2658 m0->m_pkthdr.len += (8 - extra); 2659 } else { 2660 /* truncate */ 2661 m0->m_pkthdr.len -= extra; 2662 m0->m_len -= extra; 2663 } 2664 } 2665 len = m0->m_pkthdr.len + sizeof(*nd_opt_rh); 2666 m0->m_pkthdr.len = m0->m_len = len - 2667 sizeof(*nd_opt_rh); 2668 } 2669 2670 nd_opt_rh = (struct nd_opt_rd_hdr *)p; 2671 bzero(nd_opt_rh, sizeof(*nd_opt_rh)); 2672 nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER; 2673 nd_opt_rh->nd_opt_rh_len = len >> 3; 2674 p += sizeof(*nd_opt_rh); 2675 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2676 2677 /* connect m0 to m */ 2678 m_tag_delete_chain(m0, NULL); 2679 m0->m_flags &= ~M_PKTHDR; 2680 m->m_next = m0; 2681 m->m_pkthdr.len = m->m_len + m0->m_len; 2682 m0 = NULL; 2683 } 2684 noredhdropt:; 2685 if (m0) { 2686 m_freem(m0); 2687 m0 = NULL; 2688 } 2689 2690 /* XXX: clear embedded link IDs in the inner header */ 2691 in6_clearscope(&sip6->ip6_src); 2692 in6_clearscope(&sip6->ip6_dst); 2693 in6_clearscope(&nd_rd->nd_rd_target); 2694 in6_clearscope(&nd_rd->nd_rd_dst); 2695 2696 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr)); 2697 2698 nd_rd->nd_rd_cksum = 0; 2699 nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2700 sizeof(*ip6), ntohs(ip6->ip6_plen)); 2701 2702 if (send_sendso_input_hook != NULL) { 2703 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, sizeof(unsigned short), 2704 M_NOWAIT); 2705 if (mtag == NULL) 2706 goto fail; 2707 *(unsigned short *)(mtag + 1) = nd_rd->nd_rd_type; 2708 m_tag_prepend(m, mtag); 2709 } 2710 2711 /* send the packet to outside... */ 2712 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2713 if (outif) { 2714 icmp6_ifstat_inc(outif, ifs6_out_msg); 2715 icmp6_ifstat_inc(outif, ifs6_out_redirect); 2716 } 2717 ICMP6STAT_INC(icp6s_outhist[ND_REDIRECT]); 2718 2719 return; 2720 2721 fail: 2722 if (m) 2723 m_freem(m); 2724 if (m0) 2725 m_freem(m0); 2726 } 2727 2728 /* 2729 * ICMPv6 socket option processing. 2730 */ 2731 int 2732 icmp6_ctloutput(struct socket *so, struct sockopt *sopt) 2733 { 2734 int error = 0; 2735 int optlen; 2736 struct inpcb *inp = sotoinpcb(so); 2737 int level, op, optname; 2738 2739 if (sopt) { 2740 level = sopt->sopt_level; 2741 op = sopt->sopt_dir; 2742 optname = sopt->sopt_name; 2743 optlen = sopt->sopt_valsize; 2744 } else 2745 level = op = optname = optlen = 0; 2746 2747 if (level != IPPROTO_ICMPV6) { 2748 return EINVAL; 2749 } 2750 2751 switch (op) { 2752 case PRCO_SETOPT: 2753 switch (optname) { 2754 case ICMP6_FILTER: 2755 { 2756 struct icmp6_filter ic6f; 2757 2758 if (optlen != sizeof(ic6f)) { 2759 error = EMSGSIZE; 2760 break; 2761 } 2762 error = sooptcopyin(sopt, &ic6f, optlen, optlen); 2763 if (error == 0) { 2764 INP_WLOCK(inp); 2765 *inp->in6p_icmp6filt = ic6f; 2766 INP_WUNLOCK(inp); 2767 } 2768 break; 2769 } 2770 2771 default: 2772 error = ENOPROTOOPT; 2773 break; 2774 } 2775 break; 2776 2777 case PRCO_GETOPT: 2778 switch (optname) { 2779 case ICMP6_FILTER: 2780 { 2781 struct icmp6_filter ic6f; 2782 2783 INP_RLOCK(inp); 2784 ic6f = *inp->in6p_icmp6filt; 2785 INP_RUNLOCK(inp); 2786 error = sooptcopyout(sopt, &ic6f, sizeof(ic6f)); 2787 break; 2788 } 2789 2790 default: 2791 error = ENOPROTOOPT; 2792 break; 2793 } 2794 break; 2795 } 2796 2797 return (error); 2798 } 2799 2800 /* 2801 * Perform rate limit check. 2802 * Returns 0 if it is okay to send the icmp6 packet. 2803 * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate 2804 * limitation. 2805 * 2806 * XXX per-destination/type check necessary? 2807 * 2808 * dst - not used at this moment 2809 * type - not used at this moment 2810 * code - not used at this moment 2811 */ 2812 static int 2813 icmp6_ratelimit(const struct in6_addr *dst, const int type, 2814 const int code) 2815 { 2816 int ret; 2817 2818 ret = 0; /* okay to send */ 2819 2820 /* PPS limit */ 2821 if (!ppsratecheck(&V_icmp6errppslim_last, &V_icmp6errpps_count, 2822 V_icmp6errppslim)) { 2823 /* The packet is subject to rate limit */ 2824 ret++; 2825 } 2826 2827 return ret; 2828 } 2829