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 IP6_EXTHDR_GET(nicmp6, struct icmp6_hdr *, n, off, 598 sizeof(*nicmp6)); 599 noff = off; 600 } 601 if (n) { 602 nicmp6->icmp6_type = ICMP6_ECHO_REPLY; 603 nicmp6->icmp6_code = 0; 604 ICMP6STAT_INC(icp6s_reflect); 605 ICMP6STAT_INC(icp6s_outhist[ICMP6_ECHO_REPLY]); 606 icmp6_reflect(n, noff); 607 } 608 break; 609 610 case ICMP6_ECHO_REPLY: 611 icmp6_ifstat_inc(ifp, ifs6_in_echoreply); 612 if (code != 0) 613 goto badcode; 614 break; 615 616 case MLD_LISTENER_QUERY: 617 case MLD_LISTENER_REPORT: 618 case MLD_LISTENER_DONE: 619 case MLDV2_LISTENER_REPORT: 620 /* 621 * Drop MLD traffic which is not link-local, has a hop limit 622 * of greater than 1 hop, or which does not have the 623 * IPv6 HBH Router Alert option. 624 * As IPv6 HBH options are stripped in ip6_input() we must 625 * check an mbuf header flag. 626 * XXX Should we also sanity check that these messages 627 * were directed to a link-local multicast prefix? 628 */ 629 if ((ip6->ip6_hlim != 1) || (m->m_flags & M_RTALERT_MLD) == 0) 630 goto freeit; 631 if (mld_input(m, off, icmp6len) != 0) 632 return (IPPROTO_DONE); 633 /* m stays. */ 634 break; 635 636 case ICMP6_WRUREQUEST: /* ICMP6_FQDN_QUERY */ 637 { 638 enum { WRU, FQDN } mode; 639 640 if (!V_icmp6_nodeinfo) 641 break; 642 643 if (icmp6len == sizeof(struct icmp6_hdr) + 4) 644 mode = WRU; 645 else if (icmp6len >= sizeof(struct icmp6_nodeinfo)) 646 mode = FQDN; 647 else 648 goto badlen; 649 650 if (mode == FQDN) { 651 #ifndef PULLDOWN_TEST 652 IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_nodeinfo), 653 IPPROTO_DONE); 654 #endif 655 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 656 if (n) 657 n = ni6_input(n, off); 658 /* XXX meaningless if n == NULL */ 659 noff = sizeof(struct ip6_hdr); 660 } else { 661 struct prison *pr; 662 u_char *p; 663 int maxhlen, hlen; 664 665 /* 666 * XXX: this combination of flags is pointless, 667 * but should we keep this for compatibility? 668 */ 669 if ((V_icmp6_nodeinfo & (ICMP6_NODEINFO_FQDNOK | 670 ICMP6_NODEINFO_TMPADDROK)) != 671 (ICMP6_NODEINFO_FQDNOK | ICMP6_NODEINFO_TMPADDROK)) 672 break; 673 674 if (code != 0) 675 goto badcode; 676 677 CTASSERT(sizeof(*nip6) + sizeof(*nicmp6) + 4 <= MHLEN); 678 n = m_gethdr(M_NOWAIT, m->m_type); 679 if (n == NULL) { 680 /* Give up remote */ 681 break; 682 } 683 if (!m_dup_pkthdr(n, m, M_NOWAIT)) { 684 /* 685 * Previous code did a blind M_COPY_PKTHDR 686 * and said "just for rcvif". If true, then 687 * we could tolerate the dup failing (due to 688 * the deep copy of the tag chain). For now 689 * be conservative and just fail. 690 */ 691 m_free(n); 692 n = NULL; 693 break; 694 } 695 maxhlen = M_TRAILINGSPACE(n) - 696 (sizeof(*nip6) + sizeof(*nicmp6) + 4); 697 pr = curthread->td_ucred->cr_prison; 698 mtx_lock(&pr->pr_mtx); 699 hlen = strlen(pr->pr_hostname); 700 if (maxhlen > hlen) 701 maxhlen = hlen; 702 /* 703 * Copy IPv6 and ICMPv6 only. 704 */ 705 nip6 = mtod(n, struct ip6_hdr *); 706 bcopy(ip6, nip6, sizeof(struct ip6_hdr)); 707 nicmp6 = (struct icmp6_hdr *)(nip6 + 1); 708 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr)); 709 p = (u_char *)(nicmp6 + 1); 710 bzero(p, 4); 711 /* meaningless TTL */ 712 bcopy(pr->pr_hostname, p + 4, maxhlen); 713 mtx_unlock(&pr->pr_mtx); 714 noff = sizeof(struct ip6_hdr); 715 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + 716 sizeof(struct icmp6_hdr) + 4 + maxhlen; 717 nicmp6->icmp6_type = ICMP6_WRUREPLY; 718 nicmp6->icmp6_code = 0; 719 } 720 if (n) { 721 ICMP6STAT_INC(icp6s_reflect); 722 ICMP6STAT_INC(icp6s_outhist[ICMP6_WRUREPLY]); 723 icmp6_reflect(n, noff); 724 } 725 break; 726 } 727 728 case ICMP6_WRUREPLY: 729 if (code != 0) 730 goto badcode; 731 break; 732 733 case ND_ROUTER_SOLICIT: 734 icmp6_ifstat_inc(ifp, ifs6_in_routersolicit); 735 if (code != 0) 736 goto badcode; 737 if (icmp6len < sizeof(struct nd_router_solicit)) 738 goto badlen; 739 if (send_sendso_input_hook != NULL) { 740 IP6_EXTHDR_CHECK(m, off, icmp6len, IPPROTO_DONE); 741 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 742 if (error == 0) { 743 m = NULL; 744 goto freeit; 745 } 746 } 747 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 748 nd6_rs_input(m, off, icmp6len); 749 m = n; 750 if (m == NULL) 751 goto freeit; 752 break; 753 754 case ND_ROUTER_ADVERT: 755 icmp6_ifstat_inc(ifp, ifs6_in_routeradvert); 756 if (code != 0) 757 goto badcode; 758 if (icmp6len < sizeof(struct nd_router_advert)) 759 goto badlen; 760 if (send_sendso_input_hook != NULL) { 761 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 762 if (error == 0) { 763 m = NULL; 764 goto freeit; 765 } 766 } 767 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 768 nd6_ra_input(m, off, icmp6len); 769 m = n; 770 if (m == NULL) 771 goto freeit; 772 break; 773 774 case ND_NEIGHBOR_SOLICIT: 775 icmp6_ifstat_inc(ifp, ifs6_in_neighborsolicit); 776 if (code != 0) 777 goto badcode; 778 if (icmp6len < sizeof(struct nd_neighbor_solicit)) 779 goto badlen; 780 if (send_sendso_input_hook != NULL) { 781 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 782 if (error == 0) { 783 m = NULL; 784 goto freeit; 785 } 786 } 787 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 788 nd6_ns_input(m, off, icmp6len); 789 m = n; 790 if (m == NULL) 791 goto freeit; 792 break; 793 794 case ND_NEIGHBOR_ADVERT: 795 icmp6_ifstat_inc(ifp, ifs6_in_neighboradvert); 796 if (code != 0) 797 goto badcode; 798 if (icmp6len < sizeof(struct nd_neighbor_advert)) 799 goto badlen; 800 if (send_sendso_input_hook != NULL) { 801 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 802 if (error == 0) { 803 m = NULL; 804 goto freeit; 805 } 806 } 807 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 808 nd6_na_input(m, off, icmp6len); 809 m = n; 810 if (m == NULL) 811 goto freeit; 812 break; 813 814 case ND_REDIRECT: 815 icmp6_ifstat_inc(ifp, ifs6_in_redirect); 816 if (code != 0) 817 goto badcode; 818 if (icmp6len < sizeof(struct nd_redirect)) 819 goto badlen; 820 if (send_sendso_input_hook != NULL) { 821 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 822 if (error == 0) { 823 m = NULL; 824 goto freeit; 825 } 826 } 827 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 828 icmp6_redirect_input(m, off); 829 m = n; 830 if (m == NULL) 831 goto freeit; 832 break; 833 834 case ICMP6_ROUTER_RENUMBERING: 835 if (code != ICMP6_ROUTER_RENUMBERING_COMMAND && 836 code != ICMP6_ROUTER_RENUMBERING_RESULT) 837 goto badcode; 838 if (icmp6len < sizeof(struct icmp6_router_renum)) 839 goto badlen; 840 break; 841 842 default: 843 nd6log((LOG_DEBUG, 844 "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n", 845 icmp6->icmp6_type, ip6_sprintf(ip6bufs, &ip6->ip6_src), 846 ip6_sprintf(ip6bufd, &ip6->ip6_dst), 847 ifp ? ifp->if_index : 0)); 848 if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) { 849 /* ICMPv6 error: MUST deliver it by spec... */ 850 code = PRC_NCMDS; 851 /* deliver */ 852 } else { 853 /* ICMPv6 informational: MUST not deliver */ 854 break; 855 } 856 deliver: 857 if (icmp6_notify_error(&m, off, icmp6len, code) != 0) { 858 /* In this case, m should've been freed. */ 859 return (IPPROTO_DONE); 860 } 861 break; 862 863 badcode: 864 ICMP6STAT_INC(icp6s_badcode); 865 break; 866 867 badlen: 868 ICMP6STAT_INC(icp6s_badlen); 869 break; 870 } 871 872 /* deliver the packet to appropriate sockets */ 873 icmp6_rip6_input(&m, *offp); 874 875 return IPPROTO_DONE; 876 877 freeit: 878 m_freem(m); 879 return IPPROTO_DONE; 880 } 881 882 static int 883 icmp6_notify_error(struct mbuf **mp, int off, int icmp6len, int code) 884 { 885 struct mbuf *m = *mp; 886 struct icmp6_hdr *icmp6; 887 struct ip6_hdr *eip6; 888 u_int32_t notifymtu; 889 struct sockaddr_in6 icmp6src, icmp6dst; 890 891 if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) { 892 ICMP6STAT_INC(icp6s_tooshort); 893 goto freeit; 894 } 895 #ifndef PULLDOWN_TEST 896 IP6_EXTHDR_CHECK(m, off, 897 sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr), -1); 898 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 899 #else 900 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, 901 sizeof(*icmp6) + sizeof(struct ip6_hdr)); 902 if (icmp6 == NULL) { 903 ICMP6STAT_INC(icp6s_tooshort); 904 return (-1); 905 } 906 #endif 907 eip6 = (struct ip6_hdr *)(icmp6 + 1); 908 909 /* Detect the upper level protocol */ 910 { 911 void (*ctlfunc)(int, struct sockaddr *, void *); 912 u_int8_t nxt = eip6->ip6_nxt; 913 int eoff = off + sizeof(struct icmp6_hdr) + 914 sizeof(struct ip6_hdr); 915 struct ip6ctlparam ip6cp; 916 struct in6_addr *finaldst = NULL; 917 int icmp6type = icmp6->icmp6_type; 918 struct ip6_frag *fh; 919 struct ip6_rthdr *rth; 920 struct ip6_rthdr0 *rth0; 921 int rthlen; 922 923 while (1) { /* XXX: should avoid infinite loop explicitly? */ 924 struct ip6_ext *eh; 925 926 switch (nxt) { 927 case IPPROTO_HOPOPTS: 928 case IPPROTO_DSTOPTS: 929 case IPPROTO_AH: 930 #ifndef PULLDOWN_TEST 931 IP6_EXTHDR_CHECK(m, 0, 932 eoff + sizeof(struct ip6_ext), -1); 933 eh = (struct ip6_ext *)(mtod(m, caddr_t) + eoff); 934 #else 935 IP6_EXTHDR_GET(eh, struct ip6_ext *, m, 936 eoff, sizeof(*eh)); 937 if (eh == NULL) { 938 ICMP6STAT_INC(icp6s_tooshort); 939 return (-1); 940 } 941 #endif 942 943 if (nxt == IPPROTO_AH) 944 eoff += (eh->ip6e_len + 2) << 2; 945 else 946 eoff += (eh->ip6e_len + 1) << 3; 947 nxt = eh->ip6e_nxt; 948 break; 949 case IPPROTO_ROUTING: 950 /* 951 * When the erroneous packet contains a 952 * routing header, we should examine the 953 * header to determine the final destination. 954 * Otherwise, we can't properly update 955 * information that depends on the final 956 * destination (e.g. path MTU). 957 */ 958 #ifndef PULLDOWN_TEST 959 IP6_EXTHDR_CHECK(m, 0, eoff + sizeof(*rth), -1); 960 rth = (struct ip6_rthdr *) 961 (mtod(m, caddr_t) + eoff); 962 #else 963 IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m, 964 eoff, sizeof(*rth)); 965 if (rth == NULL) { 966 ICMP6STAT_INC(icp6s_tooshort); 967 return (-1); 968 } 969 #endif 970 rthlen = (rth->ip6r_len + 1) << 3; 971 /* 972 * XXX: currently there is no 973 * officially defined type other 974 * than type-0. 975 * Note that if the segment left field 976 * is 0, all intermediate hops must 977 * have been passed. 978 */ 979 if (rth->ip6r_segleft && 980 rth->ip6r_type == IPV6_RTHDR_TYPE_0) { 981 int hops; 982 983 #ifndef PULLDOWN_TEST 984 IP6_EXTHDR_CHECK(m, 0, eoff + rthlen, -1); 985 rth0 = (struct ip6_rthdr0 *) 986 (mtod(m, caddr_t) + eoff); 987 #else 988 IP6_EXTHDR_GET(rth0, 989 struct ip6_rthdr0 *, m, 990 eoff, rthlen); 991 if (rth0 == NULL) { 992 ICMP6STAT_INC(icp6s_tooshort); 993 return (-1); 994 } 995 #endif 996 /* just ignore a bogus header */ 997 if ((rth0->ip6r0_len % 2) == 0 && 998 (hops = rth0->ip6r0_len/2)) 999 finaldst = (struct in6_addr *)(rth0 + 1) + (hops - 1); 1000 } 1001 eoff += rthlen; 1002 nxt = rth->ip6r_nxt; 1003 break; 1004 case IPPROTO_FRAGMENT: 1005 #ifndef PULLDOWN_TEST 1006 IP6_EXTHDR_CHECK(m, 0, eoff + 1007 sizeof(struct ip6_frag), -1); 1008 fh = (struct ip6_frag *)(mtod(m, caddr_t) + 1009 eoff); 1010 #else 1011 IP6_EXTHDR_GET(fh, struct ip6_frag *, m, 1012 eoff, sizeof(*fh)); 1013 if (fh == NULL) { 1014 ICMP6STAT_INC(icp6s_tooshort); 1015 return (-1); 1016 } 1017 #endif 1018 /* 1019 * Data after a fragment header is meaningless 1020 * unless it is the first fragment, but 1021 * we'll go to the notify label for path MTU 1022 * discovery. 1023 */ 1024 if (fh->ip6f_offlg & IP6F_OFF_MASK) 1025 goto notify; 1026 1027 eoff += sizeof(struct ip6_frag); 1028 nxt = fh->ip6f_nxt; 1029 break; 1030 default: 1031 /* 1032 * This case includes ESP and the No Next 1033 * Header. In such cases going to the notify 1034 * label does not have any meaning 1035 * (i.e. ctlfunc will be NULL), but we go 1036 * anyway since we might have to update 1037 * path MTU information. 1038 */ 1039 goto notify; 1040 } 1041 } 1042 notify: 1043 #ifndef PULLDOWN_TEST 1044 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 1045 #else 1046 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, 1047 sizeof(*icmp6) + sizeof(struct ip6_hdr)); 1048 if (icmp6 == NULL) { 1049 ICMP6STAT_INC(icp6s_tooshort); 1050 return (-1); 1051 } 1052 #endif 1053 1054 /* 1055 * retrieve parameters from the inner IPv6 header, and convert 1056 * them into sockaddr structures. 1057 * XXX: there is no guarantee that the source or destination 1058 * addresses of the inner packet are in the same scope as 1059 * the addresses of the icmp packet. But there is no other 1060 * way to determine the zone. 1061 */ 1062 eip6 = (struct ip6_hdr *)(icmp6 + 1); 1063 1064 bzero(&icmp6dst, sizeof(icmp6dst)); 1065 icmp6dst.sin6_len = sizeof(struct sockaddr_in6); 1066 icmp6dst.sin6_family = AF_INET6; 1067 if (finaldst == NULL) 1068 icmp6dst.sin6_addr = eip6->ip6_dst; 1069 else 1070 icmp6dst.sin6_addr = *finaldst; 1071 if (in6_setscope(&icmp6dst.sin6_addr, m->m_pkthdr.rcvif, NULL)) 1072 goto freeit; 1073 bzero(&icmp6src, sizeof(icmp6src)); 1074 icmp6src.sin6_len = sizeof(struct sockaddr_in6); 1075 icmp6src.sin6_family = AF_INET6; 1076 icmp6src.sin6_addr = eip6->ip6_src; 1077 if (in6_setscope(&icmp6src.sin6_addr, m->m_pkthdr.rcvif, NULL)) 1078 goto freeit; 1079 icmp6src.sin6_flowinfo = 1080 (eip6->ip6_flow & IPV6_FLOWLABEL_MASK); 1081 1082 if (finaldst == NULL) 1083 finaldst = &eip6->ip6_dst; 1084 ip6cp.ip6c_m = m; 1085 ip6cp.ip6c_icmp6 = icmp6; 1086 ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1); 1087 ip6cp.ip6c_off = eoff; 1088 ip6cp.ip6c_finaldst = finaldst; 1089 ip6cp.ip6c_src = &icmp6src; 1090 ip6cp.ip6c_nxt = nxt; 1091 1092 if (icmp6type == ICMP6_PACKET_TOO_BIG) { 1093 notifymtu = ntohl(icmp6->icmp6_mtu); 1094 ip6cp.ip6c_cmdarg = (void *)¬ifymtu; 1095 icmp6_mtudisc_update(&ip6cp, 1); /*XXX*/ 1096 } 1097 1098 ctlfunc = (void (*)(int, struct sockaddr *, void *)) 1099 (inet6sw[ip6_protox[nxt]].pr_ctlinput); 1100 if (ctlfunc) { 1101 (void) (*ctlfunc)(code, (struct sockaddr *)&icmp6dst, 1102 &ip6cp); 1103 } 1104 } 1105 *mp = m; 1106 return (0); 1107 1108 freeit: 1109 m_freem(m); 1110 return (-1); 1111 } 1112 1113 void 1114 icmp6_mtudisc_update(struct ip6ctlparam *ip6cp, int validated) 1115 { 1116 struct in6_addr *dst = ip6cp->ip6c_finaldst; 1117 struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6; 1118 struct mbuf *m = ip6cp->ip6c_m; /* will be necessary for scope issue */ 1119 u_int mtu = ntohl(icmp6->icmp6_mtu); 1120 struct in_conninfo inc; 1121 1122 #if 0 1123 /* 1124 * RFC2460 section 5, last paragraph. 1125 * even though minimum link MTU for IPv6 is IPV6_MMTU, 1126 * we may see ICMPv6 too big with mtu < IPV6_MMTU 1127 * due to packet translator in the middle. 1128 * see ip6_output() and ip6_getpmtu() "alwaysfrag" case for 1129 * special handling. 1130 */ 1131 if (mtu < IPV6_MMTU) 1132 return; 1133 #endif 1134 1135 /* 1136 * we reject ICMPv6 too big with abnormally small value. 1137 * XXX what is the good definition of "abnormally small"? 1138 */ 1139 if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8) 1140 return; 1141 1142 if (!validated) 1143 return; 1144 1145 /* 1146 * In case the suggested mtu is less than IPV6_MMTU, we 1147 * only need to remember that it was for above mentioned 1148 * "alwaysfrag" case. 1149 * Try to be as close to the spec as possible. 1150 */ 1151 if (mtu < IPV6_MMTU) 1152 mtu = IPV6_MMTU - 8; 1153 1154 bzero(&inc, sizeof(inc)); 1155 inc.inc_fibnum = M_GETFIB(m); 1156 inc.inc_flags |= INC_ISIPV6; 1157 inc.inc6_faddr = *dst; 1158 if (in6_setscope(&inc.inc6_faddr, m->m_pkthdr.rcvif, NULL)) 1159 return; 1160 1161 if (mtu < tcp_maxmtu6(&inc, NULL)) { 1162 tcp_hc_updatemtu(&inc, mtu); 1163 ICMP6STAT_INC(icp6s_pmtuchg); 1164 } 1165 } 1166 1167 /* 1168 * Process a Node Information Query packet, based on 1169 * draft-ietf-ipngwg-icmp-name-lookups-07. 1170 * 1171 * Spec incompatibilities: 1172 * - IPv6 Subject address handling 1173 * - IPv4 Subject address handling support missing 1174 * - Proxy reply (answer even if it's not for me) 1175 * - joins NI group address at in6_ifattach() time only, does not cope 1176 * with hostname changes by sethostname(3) 1177 */ 1178 static struct mbuf * 1179 ni6_input(struct mbuf *m, int off) 1180 { 1181 struct icmp6_nodeinfo *ni6, *nni6; 1182 struct mbuf *n = NULL; 1183 struct prison *pr; 1184 u_int16_t qtype; 1185 int subjlen; 1186 int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); 1187 struct ni_reply_fqdn *fqdn; 1188 int addrs; /* for NI_QTYPE_NODEADDR */ 1189 struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */ 1190 struct in6_addr in6_subj; /* subject address */ 1191 struct ip6_hdr *ip6; 1192 int oldfqdn = 0; /* if 1, return pascal string (03 draft) */ 1193 char *subj = NULL; 1194 struct in6_ifaddr *ia6 = NULL; 1195 1196 ip6 = mtod(m, struct ip6_hdr *); 1197 #ifndef PULLDOWN_TEST 1198 ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off); 1199 #else 1200 IP6_EXTHDR_GET(ni6, struct icmp6_nodeinfo *, m, off, sizeof(*ni6)); 1201 if (ni6 == NULL) { 1202 /* m is already reclaimed */ 1203 return (NULL); 1204 } 1205 #endif 1206 1207 /* 1208 * Validate IPv6 source address. 1209 * The default configuration MUST be to refuse answering queries from 1210 * global-scope addresses according to RFC4602. 1211 * Notes: 1212 * - it's not very clear what "refuse" means; this implementation 1213 * simply drops it. 1214 * - it's not very easy to identify global-scope (unicast) addresses 1215 * since there are many prefixes for them. It should be safer 1216 * and in practice sufficient to check "all" but loopback and 1217 * link-local (note that site-local unicast was deprecated and 1218 * ULA is defined as global scope-wise) 1219 */ 1220 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_GLOBALOK) == 0 && 1221 !IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) && 1222 !IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) 1223 goto bad; 1224 1225 /* 1226 * Validate IPv6 destination address. 1227 * 1228 * The Responder must discard the Query without further processing 1229 * unless it is one of the Responder's unicast or anycast addresses, or 1230 * a link-local scope multicast address which the Responder has joined. 1231 * [RFC4602, Section 5.] 1232 */ 1233 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 1234 if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst)) 1235 goto bad; 1236 /* else it's a link-local multicast, fine */ 1237 } else { /* unicast or anycast */ 1238 ia6 = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */); 1239 if (ia6 == NULL) 1240 goto bad; /* XXX impossible */ 1241 1242 if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) && 1243 !(V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK)) { 1244 ifa_free(&ia6->ia_ifa); 1245 nd6log((LOG_DEBUG, "ni6_input: ignore node info to " 1246 "a temporary address in %s:%d", 1247 __FILE__, __LINE__)); 1248 goto bad; 1249 } 1250 ifa_free(&ia6->ia_ifa); 1251 } 1252 1253 /* validate query Subject field. */ 1254 qtype = ntohs(ni6->ni_qtype); 1255 subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo); 1256 switch (qtype) { 1257 case NI_QTYPE_NOOP: 1258 case NI_QTYPE_SUPTYPES: 1259 /* 07 draft */ 1260 if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0) 1261 break; 1262 /* FALLTHROUGH */ 1263 case NI_QTYPE_FQDN: 1264 case NI_QTYPE_NODEADDR: 1265 case NI_QTYPE_IPV4ADDR: 1266 switch (ni6->ni_code) { 1267 case ICMP6_NI_SUBJ_IPV6: 1268 #if ICMP6_NI_SUBJ_IPV6 != 0 1269 case 0: 1270 #endif 1271 /* 1272 * backward compatibility - try to accept 03 draft 1273 * format, where no Subject is present. 1274 */ 1275 if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 && 1276 subjlen == 0) { 1277 oldfqdn++; 1278 break; 1279 } 1280 #if ICMP6_NI_SUBJ_IPV6 != 0 1281 if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6) 1282 goto bad; 1283 #endif 1284 1285 if (subjlen != sizeof(struct in6_addr)) 1286 goto bad; 1287 1288 /* 1289 * Validate Subject address. 1290 * 1291 * Not sure what exactly "address belongs to the node" 1292 * means in the spec, is it just unicast, or what? 1293 * 1294 * At this moment we consider Subject address as 1295 * "belong to the node" if the Subject address equals 1296 * to the IPv6 destination address; validation for 1297 * IPv6 destination address should have done enough 1298 * check for us. 1299 * 1300 * We do not do proxy at this moment. 1301 */ 1302 /* m_pulldown instead of copy? */ 1303 m_copydata(m, off + sizeof(struct icmp6_nodeinfo), 1304 subjlen, (caddr_t)&in6_subj); 1305 if (in6_setscope(&in6_subj, m->m_pkthdr.rcvif, NULL)) 1306 goto bad; 1307 1308 subj = (char *)&in6_subj; 1309 if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &in6_subj)) 1310 break; 1311 1312 /* 1313 * XXX if we are to allow other cases, we should really 1314 * be careful about scope here. 1315 * basically, we should disallow queries toward IPv6 1316 * destination X with subject Y, 1317 * if scope(X) > scope(Y). 1318 * if we allow scope(X) > scope(Y), it will result in 1319 * information leakage across scope boundary. 1320 */ 1321 goto bad; 1322 1323 case ICMP6_NI_SUBJ_FQDN: 1324 /* 1325 * Validate Subject name with gethostname(3). 1326 * 1327 * The behavior may need some debate, since: 1328 * - we are not sure if the node has FQDN as 1329 * hostname (returned by gethostname(3)). 1330 * - the code does wildcard match for truncated names. 1331 * however, we are not sure if we want to perform 1332 * wildcard match, if gethostname(3) side has 1333 * truncated hostname. 1334 */ 1335 pr = curthread->td_ucred->cr_prison; 1336 mtx_lock(&pr->pr_mtx); 1337 n = ni6_nametodns(pr->pr_hostname, 1338 strlen(pr->pr_hostname), 0); 1339 mtx_unlock(&pr->pr_mtx); 1340 if (!n || n->m_next || n->m_len == 0) 1341 goto bad; 1342 IP6_EXTHDR_GET(subj, char *, m, 1343 off + sizeof(struct icmp6_nodeinfo), subjlen); 1344 if (subj == NULL) 1345 goto bad; 1346 if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *), 1347 n->m_len)) { 1348 goto bad; 1349 } 1350 m_freem(n); 1351 n = NULL; 1352 break; 1353 1354 case ICMP6_NI_SUBJ_IPV4: /* XXX: to be implemented? */ 1355 default: 1356 goto bad; 1357 } 1358 break; 1359 } 1360 1361 /* refuse based on configuration. XXX ICMP6_NI_REFUSED? */ 1362 switch (qtype) { 1363 case NI_QTYPE_FQDN: 1364 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_FQDNOK) == 0) 1365 goto bad; 1366 break; 1367 case NI_QTYPE_NODEADDR: 1368 case NI_QTYPE_IPV4ADDR: 1369 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_NODEADDROK) == 0) 1370 goto bad; 1371 break; 1372 } 1373 1374 /* guess reply length */ 1375 switch (qtype) { 1376 case NI_QTYPE_NOOP: 1377 break; /* no reply data */ 1378 case NI_QTYPE_SUPTYPES: 1379 replylen += sizeof(u_int32_t); 1380 break; 1381 case NI_QTYPE_FQDN: 1382 /* XXX will append an mbuf */ 1383 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); 1384 break; 1385 case NI_QTYPE_NODEADDR: 1386 addrs = ni6_addrs(ni6, m, &ifp, (struct in6_addr *)subj); 1387 if ((replylen += addrs * (sizeof(struct in6_addr) + 1388 sizeof(u_int32_t))) > MCLBYTES) 1389 replylen = MCLBYTES; /* XXX: will truncate pkt later */ 1390 break; 1391 case NI_QTYPE_IPV4ADDR: 1392 /* unsupported - should respond with unknown Qtype? */ 1393 break; 1394 default: 1395 /* 1396 * XXX: We must return a reply with the ICMP6 code 1397 * `unknown Qtype' in this case. However we regard the case 1398 * as an FQDN query for backward compatibility. 1399 * Older versions set a random value to this field, 1400 * so it rarely varies in the defined qtypes. 1401 * But the mechanism is not reliable... 1402 * maybe we should obsolete older versions. 1403 */ 1404 qtype = NI_QTYPE_FQDN; 1405 /* XXX will append an mbuf */ 1406 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); 1407 oldfqdn++; 1408 break; 1409 } 1410 1411 /* Allocate an mbuf to reply. */ 1412 if (replylen > MCLBYTES) { 1413 /* 1414 * XXX: should we try to allocate more? But MCLBYTES 1415 * is probably much larger than IPV6_MMTU... 1416 */ 1417 goto bad; 1418 } 1419 if (replylen > MHLEN) 1420 n = m_getcl(M_NOWAIT, m->m_type, M_PKTHDR); 1421 else 1422 n = m_gethdr(M_NOWAIT, m->m_type); 1423 if (n == NULL) { 1424 m_freem(m); 1425 return (NULL); 1426 } 1427 m_move_pkthdr(n, m); /* just for recvif and FIB */ 1428 n->m_pkthdr.len = n->m_len = replylen; 1429 1430 /* copy mbuf header and IPv6 + Node Information base headers */ 1431 bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr)); 1432 nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1); 1433 bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo)); 1434 1435 /* qtype dependent procedure */ 1436 switch (qtype) { 1437 case NI_QTYPE_NOOP: 1438 nni6->ni_code = ICMP6_NI_SUCCESS; 1439 nni6->ni_flags = 0; 1440 break; 1441 case NI_QTYPE_SUPTYPES: 1442 { 1443 u_int32_t v; 1444 nni6->ni_code = ICMP6_NI_SUCCESS; 1445 nni6->ni_flags = htons(0x0000); /* raw bitmap */ 1446 /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */ 1447 v = (u_int32_t)htonl(0x0000000f); 1448 bcopy(&v, nni6 + 1, sizeof(u_int32_t)); 1449 break; 1450 } 1451 case NI_QTYPE_FQDN: 1452 nni6->ni_code = ICMP6_NI_SUCCESS; 1453 fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) + 1454 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo)); 1455 nni6->ni_flags = 0; /* XXX: meaningless TTL */ 1456 fqdn->ni_fqdn_ttl = 0; /* ditto. */ 1457 /* 1458 * XXX do we really have FQDN in hostname? 1459 */ 1460 pr = curthread->td_ucred->cr_prison; 1461 mtx_lock(&pr->pr_mtx); 1462 n->m_next = ni6_nametodns(pr->pr_hostname, 1463 strlen(pr->pr_hostname), oldfqdn); 1464 mtx_unlock(&pr->pr_mtx); 1465 if (n->m_next == NULL) 1466 goto bad; 1467 /* XXX we assume that n->m_next is not a chain */ 1468 if (n->m_next->m_next != NULL) 1469 goto bad; 1470 n->m_pkthdr.len += n->m_next->m_len; 1471 break; 1472 case NI_QTYPE_NODEADDR: 1473 { 1474 int lenlim, copied; 1475 1476 nni6->ni_code = ICMP6_NI_SUCCESS; 1477 n->m_pkthdr.len = n->m_len = 1478 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); 1479 lenlim = M_TRAILINGSPACE(n); 1480 copied = ni6_store_addrs(ni6, nni6, ifp, lenlim); 1481 /* XXX: reset mbuf length */ 1482 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + 1483 sizeof(struct icmp6_nodeinfo) + copied; 1484 break; 1485 } 1486 default: 1487 break; /* XXX impossible! */ 1488 } 1489 1490 nni6->ni_type = ICMP6_NI_REPLY; 1491 m_freem(m); 1492 return (n); 1493 1494 bad: 1495 m_freem(m); 1496 if (n) 1497 m_freem(n); 1498 return (NULL); 1499 } 1500 1501 /* 1502 * make a mbuf with DNS-encoded string. no compression support. 1503 * 1504 * XXX names with less than 2 dots (like "foo" or "foo.section") will be 1505 * treated as truncated name (two \0 at the end). this is a wild guess. 1506 * 1507 * old - return pascal string if non-zero 1508 */ 1509 static struct mbuf * 1510 ni6_nametodns(const char *name, int namelen, int old) 1511 { 1512 struct mbuf *m; 1513 char *cp, *ep; 1514 const char *p, *q; 1515 int i, len, nterm; 1516 1517 if (old) 1518 len = namelen + 1; 1519 else 1520 len = MCLBYTES; 1521 1522 /* Because MAXHOSTNAMELEN is usually 256, we use cluster mbuf. */ 1523 if (len > MLEN) 1524 m = m_getcl(M_NOWAIT, MT_DATA, 0); 1525 else 1526 m = m_get(M_NOWAIT, MT_DATA); 1527 if (m == NULL) 1528 goto fail; 1529 1530 if (old) { 1531 m->m_len = len; 1532 *mtod(m, char *) = namelen; 1533 bcopy(name, mtod(m, char *) + 1, namelen); 1534 return m; 1535 } else { 1536 m->m_len = 0; 1537 cp = mtod(m, char *); 1538 ep = mtod(m, char *) + M_TRAILINGSPACE(m); 1539 1540 /* if not certain about my name, return empty buffer */ 1541 if (namelen == 0) 1542 return m; 1543 1544 /* 1545 * guess if it looks like shortened hostname, or FQDN. 1546 * shortened hostname needs two trailing "\0". 1547 */ 1548 i = 0; 1549 for (p = name; p < name + namelen; p++) { 1550 if (*p && *p == '.') 1551 i++; 1552 } 1553 if (i < 2) 1554 nterm = 2; 1555 else 1556 nterm = 1; 1557 1558 p = name; 1559 while (cp < ep && p < name + namelen) { 1560 i = 0; 1561 for (q = p; q < name + namelen && *q && *q != '.'; q++) 1562 i++; 1563 /* result does not fit into mbuf */ 1564 if (cp + i + 1 >= ep) 1565 goto fail; 1566 /* 1567 * DNS label length restriction, RFC1035 page 8. 1568 * "i == 0" case is included here to avoid returning 1569 * 0-length label on "foo..bar". 1570 */ 1571 if (i <= 0 || i >= 64) 1572 goto fail; 1573 *cp++ = i; 1574 bcopy(p, cp, i); 1575 cp += i; 1576 p = q; 1577 if (p < name + namelen && *p == '.') 1578 p++; 1579 } 1580 /* termination */ 1581 if (cp + nterm >= ep) 1582 goto fail; 1583 while (nterm-- > 0) 1584 *cp++ = '\0'; 1585 m->m_len = cp - mtod(m, char *); 1586 return m; 1587 } 1588 1589 panic("should not reach here"); 1590 /* NOTREACHED */ 1591 1592 fail: 1593 if (m) 1594 m_freem(m); 1595 return NULL; 1596 } 1597 1598 /* 1599 * check if two DNS-encoded string matches. takes care of truncated 1600 * form (with \0\0 at the end). no compression support. 1601 * XXX upper/lowercase match (see RFC2065) 1602 */ 1603 static int 1604 ni6_dnsmatch(const char *a, int alen, const char *b, int blen) 1605 { 1606 const char *a0, *b0; 1607 int l; 1608 1609 /* simplest case - need validation? */ 1610 if (alen == blen && bcmp(a, b, alen) == 0) 1611 return 1; 1612 1613 a0 = a; 1614 b0 = b; 1615 1616 /* termination is mandatory */ 1617 if (alen < 2 || blen < 2) 1618 return 0; 1619 if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0') 1620 return 0; 1621 alen--; 1622 blen--; 1623 1624 while (a - a0 < alen && b - b0 < blen) { 1625 if (a - a0 + 1 > alen || b - b0 + 1 > blen) 1626 return 0; 1627 1628 if ((signed char)a[0] < 0 || (signed char)b[0] < 0) 1629 return 0; 1630 /* we don't support compression yet */ 1631 if (a[0] >= 64 || b[0] >= 64) 1632 return 0; 1633 1634 /* truncated case */ 1635 if (a[0] == 0 && a - a0 == alen - 1) 1636 return 1; 1637 if (b[0] == 0 && b - b0 == blen - 1) 1638 return 1; 1639 if (a[0] == 0 || b[0] == 0) 1640 return 0; 1641 1642 if (a[0] != b[0]) 1643 return 0; 1644 l = a[0]; 1645 if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen) 1646 return 0; 1647 if (bcmp(a + 1, b + 1, l) != 0) 1648 return 0; 1649 1650 a += 1 + l; 1651 b += 1 + l; 1652 } 1653 1654 if (a - a0 == alen && b - b0 == blen) 1655 return 1; 1656 else 1657 return 0; 1658 } 1659 1660 /* 1661 * calculate the number of addresses to be returned in the node info reply. 1662 */ 1663 static int 1664 ni6_addrs(struct icmp6_nodeinfo *ni6, struct mbuf *m, struct ifnet **ifpp, 1665 struct in6_addr *subj) 1666 { 1667 struct ifnet *ifp; 1668 struct in6_ifaddr *ifa6; 1669 struct ifaddr *ifa; 1670 int addrs = 0, addrsofif, iffound = 0; 1671 int niflags = ni6->ni_flags; 1672 1673 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) { 1674 switch (ni6->ni_code) { 1675 case ICMP6_NI_SUBJ_IPV6: 1676 if (subj == NULL) /* must be impossible... */ 1677 return (0); 1678 break; 1679 default: 1680 /* 1681 * XXX: we only support IPv6 subject address for 1682 * this Qtype. 1683 */ 1684 return (0); 1685 } 1686 } 1687 1688 IFNET_RLOCK_NOSLEEP(); 1689 TAILQ_FOREACH(ifp, &V_ifnet, if_link) { 1690 addrsofif = 0; 1691 IF_ADDR_RLOCK(ifp); 1692 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 1693 if (ifa->ifa_addr->sa_family != AF_INET6) 1694 continue; 1695 ifa6 = (struct in6_ifaddr *)ifa; 1696 1697 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 && 1698 IN6_ARE_ADDR_EQUAL(subj, &ifa6->ia_addr.sin6_addr)) 1699 iffound = 1; 1700 1701 /* 1702 * IPv4-mapped addresses can only be returned by a 1703 * Node Information proxy, since they represent 1704 * addresses of IPv4-only nodes, which perforce do 1705 * not implement this protocol. 1706 * [icmp-name-lookups-07, Section 5.4] 1707 * So we don't support NI_NODEADDR_FLAG_COMPAT in 1708 * this function at this moment. 1709 */ 1710 1711 /* What do we have to do about ::1? */ 1712 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { 1713 case IPV6_ADDR_SCOPE_LINKLOCAL: 1714 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) 1715 continue; 1716 break; 1717 case IPV6_ADDR_SCOPE_SITELOCAL: 1718 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) 1719 continue; 1720 break; 1721 case IPV6_ADDR_SCOPE_GLOBAL: 1722 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) 1723 continue; 1724 break; 1725 default: 1726 continue; 1727 } 1728 1729 /* 1730 * check if anycast is okay. 1731 * XXX: just experimental. not in the spec. 1732 */ 1733 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && 1734 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) 1735 continue; /* we need only unicast addresses */ 1736 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && 1737 (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) { 1738 continue; 1739 } 1740 addrsofif++; /* count the address */ 1741 } 1742 IF_ADDR_RUNLOCK(ifp); 1743 if (iffound) { 1744 *ifpp = ifp; 1745 IFNET_RUNLOCK_NOSLEEP(); 1746 return (addrsofif); 1747 } 1748 1749 addrs += addrsofif; 1750 } 1751 IFNET_RUNLOCK_NOSLEEP(); 1752 1753 return (addrs); 1754 } 1755 1756 static int 1757 ni6_store_addrs(struct icmp6_nodeinfo *ni6, struct icmp6_nodeinfo *nni6, 1758 struct ifnet *ifp0, int resid) 1759 { 1760 struct ifnet *ifp; 1761 struct in6_ifaddr *ifa6; 1762 struct ifaddr *ifa; 1763 struct ifnet *ifp_dep = NULL; 1764 int copied = 0, allow_deprecated = 0; 1765 u_char *cp = (u_char *)(nni6 + 1); 1766 int niflags = ni6->ni_flags; 1767 u_int32_t ltime; 1768 1769 if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL)) 1770 return (0); /* needless to copy */ 1771 1772 IFNET_RLOCK_NOSLEEP(); 1773 ifp = ifp0 ? ifp0 : TAILQ_FIRST(&V_ifnet); 1774 again: 1775 1776 for (; ifp; ifp = TAILQ_NEXT(ifp, if_link)) { 1777 IF_ADDR_RLOCK(ifp); 1778 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 1779 if (ifa->ifa_addr->sa_family != AF_INET6) 1780 continue; 1781 ifa6 = (struct in6_ifaddr *)ifa; 1782 1783 if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 && 1784 allow_deprecated == 0) { 1785 /* 1786 * prefererred address should be put before 1787 * deprecated addresses. 1788 */ 1789 1790 /* record the interface for later search */ 1791 if (ifp_dep == NULL) 1792 ifp_dep = ifp; 1793 1794 continue; 1795 } else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 && 1796 allow_deprecated != 0) 1797 continue; /* we now collect deprecated addrs */ 1798 1799 /* What do we have to do about ::1? */ 1800 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { 1801 case IPV6_ADDR_SCOPE_LINKLOCAL: 1802 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) 1803 continue; 1804 break; 1805 case IPV6_ADDR_SCOPE_SITELOCAL: 1806 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) 1807 continue; 1808 break; 1809 case IPV6_ADDR_SCOPE_GLOBAL: 1810 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) 1811 continue; 1812 break; 1813 default: 1814 continue; 1815 } 1816 1817 /* 1818 * check if anycast is okay. 1819 * XXX: just experimental. not in the spec. 1820 */ 1821 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && 1822 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) 1823 continue; 1824 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && 1825 (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) { 1826 continue; 1827 } 1828 1829 /* now we can copy the address */ 1830 if (resid < sizeof(struct in6_addr) + 1831 sizeof(u_int32_t)) { 1832 IF_ADDR_RUNLOCK(ifp); 1833 /* 1834 * We give up much more copy. 1835 * Set the truncate flag and return. 1836 */ 1837 nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE; 1838 IFNET_RUNLOCK_NOSLEEP(); 1839 return (copied); 1840 } 1841 1842 /* 1843 * Set the TTL of the address. 1844 * The TTL value should be one of the following 1845 * according to the specification: 1846 * 1847 * 1. The remaining lifetime of a DHCP lease on the 1848 * address, or 1849 * 2. The remaining Valid Lifetime of a prefix from 1850 * which the address was derived through Stateless 1851 * Autoconfiguration. 1852 * 1853 * Note that we currently do not support stateful 1854 * address configuration by DHCPv6, so the former 1855 * case can't happen. 1856 */ 1857 if (ifa6->ia6_lifetime.ia6t_expire == 0) 1858 ltime = ND6_INFINITE_LIFETIME; 1859 else { 1860 if (ifa6->ia6_lifetime.ia6t_expire > 1861 time_uptime) 1862 ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_uptime); 1863 else 1864 ltime = 0; 1865 } 1866 1867 bcopy(<ime, cp, sizeof(u_int32_t)); 1868 cp += sizeof(u_int32_t); 1869 1870 /* copy the address itself */ 1871 bcopy(&ifa6->ia_addr.sin6_addr, cp, 1872 sizeof(struct in6_addr)); 1873 in6_clearscope((struct in6_addr *)cp); /* XXX */ 1874 cp += sizeof(struct in6_addr); 1875 1876 resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t)); 1877 copied += (sizeof(struct in6_addr) + sizeof(u_int32_t)); 1878 } 1879 IF_ADDR_RUNLOCK(ifp); 1880 if (ifp0) /* we need search only on the specified IF */ 1881 break; 1882 } 1883 1884 if (allow_deprecated == 0 && ifp_dep != NULL) { 1885 ifp = ifp_dep; 1886 allow_deprecated = 1; 1887 1888 goto again; 1889 } 1890 1891 IFNET_RUNLOCK_NOSLEEP(); 1892 1893 return (copied); 1894 } 1895 1896 /* 1897 * XXX almost dup'ed code with rip6_input. 1898 */ 1899 static int 1900 icmp6_rip6_input(struct mbuf **mp, int off) 1901 { 1902 struct mbuf *m = *mp; 1903 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1904 struct inpcb *in6p; 1905 struct inpcb *last = NULL; 1906 struct sockaddr_in6 fromsa; 1907 struct icmp6_hdr *icmp6; 1908 struct mbuf *opts = NULL; 1909 1910 #ifndef PULLDOWN_TEST 1911 /* this is assumed to be safe. */ 1912 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off); 1913 #else 1914 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6)); 1915 if (icmp6 == NULL) { 1916 /* m is already reclaimed */ 1917 return (IPPROTO_DONE); 1918 } 1919 #endif 1920 1921 /* 1922 * XXX: the address may have embedded scope zone ID, which should be 1923 * hidden from applications. 1924 */ 1925 bzero(&fromsa, sizeof(fromsa)); 1926 fromsa.sin6_family = AF_INET6; 1927 fromsa.sin6_len = sizeof(struct sockaddr_in6); 1928 fromsa.sin6_addr = ip6->ip6_src; 1929 if (sa6_recoverscope(&fromsa)) { 1930 m_freem(m); 1931 return (IPPROTO_DONE); 1932 } 1933 1934 INP_INFO_RLOCK(&V_ripcbinfo); 1935 LIST_FOREACH(in6p, &V_ripcb, inp_list) { 1936 if ((in6p->inp_vflag & INP_IPV6) == 0) 1937 continue; 1938 if (in6p->inp_ip_p != IPPROTO_ICMPV6) 1939 continue; 1940 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) && 1941 !IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &ip6->ip6_dst)) 1942 continue; 1943 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr) && 1944 !IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src)) 1945 continue; 1946 INP_RLOCK(in6p); 1947 if (ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type, 1948 in6p->in6p_icmp6filt)) { 1949 INP_RUNLOCK(in6p); 1950 continue; 1951 } 1952 if (last != NULL) { 1953 struct mbuf *n = NULL; 1954 1955 /* 1956 * Recent network drivers tend to allocate a single 1957 * mbuf cluster, rather than to make a couple of 1958 * mbufs without clusters. Also, since the IPv6 code 1959 * path tries to avoid m_pullup(), it is highly 1960 * probable that we still have an mbuf cluster here 1961 * even though the necessary length can be stored in an 1962 * mbuf's internal buffer. 1963 * Meanwhile, the default size of the receive socket 1964 * buffer for raw sockets is not so large. This means 1965 * the possibility of packet loss is relatively higher 1966 * than before. To avoid this scenario, we copy the 1967 * received data to a separate mbuf that does not use 1968 * a cluster, if possible. 1969 * XXX: it is better to copy the data after stripping 1970 * intermediate headers. 1971 */ 1972 if ((m->m_flags & M_EXT) && m->m_next == NULL && 1973 m->m_len <= MHLEN) { 1974 n = m_get(M_NOWAIT, m->m_type); 1975 if (n != NULL) { 1976 if (m_dup_pkthdr(n, m, M_NOWAIT)) { 1977 bcopy(m->m_data, n->m_data, 1978 m->m_len); 1979 n->m_len = m->m_len; 1980 } else { 1981 m_free(n); 1982 n = NULL; 1983 } 1984 } 1985 } 1986 if (n != NULL || 1987 (n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) != NULL) { 1988 if (last->inp_flags & INP_CONTROLOPTS) 1989 ip6_savecontrol(last, n, &opts); 1990 /* strip intermediate headers */ 1991 m_adj(n, off); 1992 SOCKBUF_LOCK(&last->inp_socket->so_rcv); 1993 if (sbappendaddr_locked( 1994 &last->inp_socket->so_rcv, 1995 (struct sockaddr *)&fromsa, n, opts) 1996 == 0) { 1997 /* should notify about lost packet */ 1998 m_freem(n); 1999 if (opts) { 2000 m_freem(opts); 2001 } 2002 SOCKBUF_UNLOCK( 2003 &last->inp_socket->so_rcv); 2004 } else 2005 sorwakeup_locked(last->inp_socket); 2006 opts = NULL; 2007 } 2008 INP_RUNLOCK(last); 2009 } 2010 last = in6p; 2011 } 2012 INP_INFO_RUNLOCK(&V_ripcbinfo); 2013 if (last != NULL) { 2014 if (last->inp_flags & INP_CONTROLOPTS) 2015 ip6_savecontrol(last, m, &opts); 2016 /* strip intermediate headers */ 2017 m_adj(m, off); 2018 2019 /* avoid using mbuf clusters if possible (see above) */ 2020 if ((m->m_flags & M_EXT) && m->m_next == NULL && 2021 m->m_len <= MHLEN) { 2022 struct mbuf *n; 2023 2024 n = m_get(M_NOWAIT, m->m_type); 2025 if (n != NULL) { 2026 if (m_dup_pkthdr(n, m, M_NOWAIT)) { 2027 bcopy(m->m_data, n->m_data, m->m_len); 2028 n->m_len = m->m_len; 2029 2030 m_freem(m); 2031 m = n; 2032 } else { 2033 m_freem(n); 2034 n = NULL; 2035 } 2036 } 2037 } 2038 SOCKBUF_LOCK(&last->inp_socket->so_rcv); 2039 if (sbappendaddr_locked(&last->inp_socket->so_rcv, 2040 (struct sockaddr *)&fromsa, m, opts) == 0) { 2041 m_freem(m); 2042 if (opts) 2043 m_freem(opts); 2044 SOCKBUF_UNLOCK(&last->inp_socket->so_rcv); 2045 } else 2046 sorwakeup_locked(last->inp_socket); 2047 INP_RUNLOCK(last); 2048 } else { 2049 m_freem(m); 2050 IP6STAT_DEC(ip6s_delivered); 2051 } 2052 return IPPROTO_DONE; 2053 } 2054 2055 /* 2056 * Reflect the ip6 packet back to the source. 2057 * OFF points to the icmp6 header, counted from the top of the mbuf. 2058 */ 2059 void 2060 icmp6_reflect(struct mbuf *m, size_t off) 2061 { 2062 struct in6_addr src6, *srcp; 2063 struct ip6_hdr *ip6; 2064 struct icmp6_hdr *icmp6; 2065 struct in6_ifaddr *ia = NULL; 2066 struct ifnet *outif = NULL; 2067 int plen; 2068 int type, code, hlim; 2069 2070 /* too short to reflect */ 2071 if (off < sizeof(struct ip6_hdr)) { 2072 nd6log((LOG_DEBUG, 2073 "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n", 2074 (u_long)off, (u_long)sizeof(struct ip6_hdr), 2075 __FILE__, __LINE__)); 2076 goto bad; 2077 } 2078 2079 /* 2080 * If there are extra headers between IPv6 and ICMPv6, strip 2081 * off that header first. 2082 */ 2083 #ifdef DIAGNOSTIC 2084 if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN) 2085 panic("assumption failed in icmp6_reflect"); 2086 #endif 2087 if (off > sizeof(struct ip6_hdr)) { 2088 size_t l; 2089 struct ip6_hdr nip6; 2090 2091 l = off - sizeof(struct ip6_hdr); 2092 m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6); 2093 m_adj(m, l); 2094 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 2095 if (m->m_len < l) { 2096 if ((m = m_pullup(m, l)) == NULL) 2097 return; 2098 } 2099 bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6)); 2100 } else /* off == sizeof(struct ip6_hdr) */ { 2101 size_t l; 2102 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 2103 if (m->m_len < l) { 2104 if ((m = m_pullup(m, l)) == NULL) 2105 return; 2106 } 2107 } 2108 plen = m->m_pkthdr.len - sizeof(struct ip6_hdr); 2109 ip6 = mtod(m, struct ip6_hdr *); 2110 ip6->ip6_nxt = IPPROTO_ICMPV6; 2111 icmp6 = (struct icmp6_hdr *)(ip6 + 1); 2112 type = icmp6->icmp6_type; /* keep type for statistics */ 2113 code = icmp6->icmp6_code; /* ditto. */ 2114 hlim = 0; 2115 srcp = NULL; 2116 2117 /* 2118 * If the incoming packet was addressed directly to us (i.e. unicast), 2119 * use dst as the src for the reply. 2120 * The IN6_IFF_NOTREADY case should be VERY rare, but is possible 2121 * (for example) when we encounter an error while forwarding procedure 2122 * destined to a duplicated address of ours. 2123 */ 2124 if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 2125 ia = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */); 2126 if (ia != NULL && !(ia->ia6_flags & 2127 (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) { 2128 src6 = ia->ia_addr.sin6_addr; 2129 srcp = &src6; 2130 2131 if (m->m_pkthdr.rcvif != NULL) { 2132 /* XXX: This may not be the outgoing interface */ 2133 hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim; 2134 } else 2135 hlim = V_ip6_defhlim; 2136 } 2137 if (ia != NULL) 2138 ifa_free(&ia->ia_ifa); 2139 } 2140 2141 if (srcp == NULL) { 2142 int error; 2143 struct in6_addr dst6; 2144 uint32_t scopeid; 2145 2146 /* 2147 * This case matches to multicasts, our anycast, or unicasts 2148 * that we do not own. Select a source address based on the 2149 * source address of the erroneous packet. 2150 */ 2151 in6_splitscope(&ip6->ip6_src, &dst6, &scopeid); 2152 error = in6_selectsrc_addr(M_GETFIB(m), &dst6, 2153 scopeid, NULL, &src6, &hlim); 2154 2155 if (error) { 2156 char ip6buf[INET6_ADDRSTRLEN]; 2157 nd6log((LOG_DEBUG, 2158 "icmp6_reflect: source can't be determined: " 2159 "dst=%s, error=%d\n", 2160 ip6_sprintf(ip6buf, &ip6->ip6_dst), error)); 2161 goto bad; 2162 } 2163 srcp = &src6; 2164 } 2165 /* 2166 * ip6_input() drops a packet if its src is multicast. 2167 * So, the src is never multicast. 2168 */ 2169 ip6->ip6_dst = ip6->ip6_src; 2170 ip6->ip6_src = *srcp; 2171 ip6->ip6_flow = 0; 2172 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2173 ip6->ip6_vfc |= IPV6_VERSION; 2174 ip6->ip6_nxt = IPPROTO_ICMPV6; 2175 ip6->ip6_hlim = hlim; 2176 2177 icmp6->icmp6_cksum = 0; 2178 icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2179 sizeof(struct ip6_hdr), plen); 2180 2181 /* 2182 * XXX option handling 2183 */ 2184 2185 m->m_flags &= ~(M_BCAST|M_MCAST); 2186 2187 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2188 if (outif) 2189 icmp6_ifoutstat_inc(outif, type, code); 2190 2191 return; 2192 2193 bad: 2194 m_freem(m); 2195 return; 2196 } 2197 2198 void 2199 icmp6_fasttimo(void) 2200 { 2201 2202 mld_fasttimo(); 2203 } 2204 2205 void 2206 icmp6_slowtimo(void) 2207 { 2208 2209 mld_slowtimo(); 2210 } 2211 2212 static const char * 2213 icmp6_redirect_diag(struct in6_addr *src6, struct in6_addr *dst6, 2214 struct in6_addr *tgt6) 2215 { 2216 static char buf[1024]; 2217 char ip6bufs[INET6_ADDRSTRLEN]; 2218 char ip6bufd[INET6_ADDRSTRLEN]; 2219 char ip6buft[INET6_ADDRSTRLEN]; 2220 snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)", 2221 ip6_sprintf(ip6bufs, src6), ip6_sprintf(ip6bufd, dst6), 2222 ip6_sprintf(ip6buft, tgt6)); 2223 return buf; 2224 } 2225 2226 void 2227 icmp6_redirect_input(struct mbuf *m, int off) 2228 { 2229 struct ifnet *ifp; 2230 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 2231 struct nd_redirect *nd_rd; 2232 int icmp6len = ntohs(ip6->ip6_plen); 2233 char *lladdr = NULL; 2234 int lladdrlen = 0; 2235 int is_router; 2236 int is_onlink; 2237 struct in6_addr src6 = ip6->ip6_src; 2238 struct in6_addr redtgt6; 2239 struct in6_addr reddst6; 2240 union nd_opts ndopts; 2241 char ip6buf[INET6_ADDRSTRLEN]; 2242 2243 M_ASSERTPKTHDR(m); 2244 KASSERT(m->m_pkthdr.rcvif != NULL, ("%s: no rcvif", __func__)); 2245 2246 ifp = m->m_pkthdr.rcvif; 2247 2248 /* XXX if we are router, we don't update route by icmp6 redirect */ 2249 if (V_ip6_forwarding) 2250 goto freeit; 2251 if (!V_icmp6_rediraccept) 2252 goto freeit; 2253 2254 /* RFC 6980: Nodes MUST silently ignore fragments */ 2255 if(m->m_flags & M_FRAGMENTED) 2256 goto freeit; 2257 2258 #ifndef PULLDOWN_TEST 2259 IP6_EXTHDR_CHECK(m, off, icmp6len,); 2260 nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off); 2261 #else 2262 IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len); 2263 if (nd_rd == NULL) { 2264 ICMP6STAT_INC(icp6s_tooshort); 2265 return; 2266 } 2267 #endif 2268 redtgt6 = nd_rd->nd_rd_target; 2269 reddst6 = nd_rd->nd_rd_dst; 2270 2271 if (in6_setscope(&redtgt6, m->m_pkthdr.rcvif, NULL) || 2272 in6_setscope(&reddst6, m->m_pkthdr.rcvif, NULL)) { 2273 goto freeit; 2274 } 2275 2276 /* validation */ 2277 if (!IN6_IS_ADDR_LINKLOCAL(&src6)) { 2278 nd6log((LOG_ERR, 2279 "ICMP6 redirect sent from %s rejected; " 2280 "must be from linklocal\n", 2281 ip6_sprintf(ip6buf, &src6))); 2282 goto bad; 2283 } 2284 if (ip6->ip6_hlim != 255) { 2285 nd6log((LOG_ERR, 2286 "ICMP6 redirect sent from %s rejected; " 2287 "hlim=%d (must be 255)\n", 2288 ip6_sprintf(ip6buf, &src6), ip6->ip6_hlim)); 2289 goto bad; 2290 } 2291 { 2292 /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */ 2293 struct nhop6_basic nh6; 2294 struct in6_addr kdst; 2295 uint32_t scopeid; 2296 2297 in6_splitscope(&reddst6, &kdst, &scopeid); 2298 if (fib6_lookup_nh_basic(ifp->if_fib, &kdst, scopeid, 0, 0,&nh6)==0){ 2299 if ((nh6.nh_flags & NHF_GATEWAY) == 0) { 2300 nd6log((LOG_ERR, 2301 "ICMP6 redirect rejected; no route " 2302 "with inet6 gateway found for redirect dst: %s\n", 2303 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2304 goto bad; 2305 } 2306 2307 /* 2308 * Embed scope zone id into next hop address, since 2309 * fib6_lookup_nh_basic() returns address without embedded 2310 * scope zone id. 2311 */ 2312 if (in6_setscope(&nh6.nh_addr, m->m_pkthdr.rcvif, NULL)) 2313 goto freeit; 2314 2315 if (IN6_ARE_ADDR_EQUAL(&src6, &nh6.nh_addr) == 0) { 2316 nd6log((LOG_ERR, 2317 "ICMP6 redirect rejected; " 2318 "not equal to gw-for-src=%s (must be same): " 2319 "%s\n", 2320 ip6_sprintf(ip6buf, &nh6.nh_addr), 2321 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2322 goto bad; 2323 } 2324 } else { 2325 nd6log((LOG_ERR, 2326 "ICMP6 redirect rejected; " 2327 "no route found for redirect dst: %s\n", 2328 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2329 goto bad; 2330 } 2331 } 2332 if (IN6_IS_ADDR_MULTICAST(&reddst6)) { 2333 nd6log((LOG_ERR, 2334 "ICMP6 redirect rejected; " 2335 "redirect dst must be unicast: %s\n", 2336 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2337 goto bad; 2338 } 2339 2340 is_router = is_onlink = 0; 2341 if (IN6_IS_ADDR_LINKLOCAL(&redtgt6)) 2342 is_router = 1; /* router case */ 2343 if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0) 2344 is_onlink = 1; /* on-link destination case */ 2345 if (!is_router && !is_onlink) { 2346 nd6log((LOG_ERR, 2347 "ICMP6 redirect rejected; " 2348 "neither router case nor onlink case: %s\n", 2349 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2350 goto bad; 2351 } 2352 2353 icmp6len -= sizeof(*nd_rd); 2354 nd6_option_init(nd_rd + 1, icmp6len, &ndopts); 2355 if (nd6_options(&ndopts) < 0) { 2356 nd6log((LOG_INFO, "%s: invalid ND option, rejected: %s\n", 2357 __func__, icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2358 /* nd6_options have incremented stats */ 2359 goto freeit; 2360 } 2361 2362 if (ndopts.nd_opts_tgt_lladdr) { 2363 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 2364 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 2365 } 2366 2367 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 2368 nd6log((LOG_INFO, "%s: lladdrlen mismatch for %s " 2369 "(if %d, icmp6 packet %d): %s\n", 2370 __func__, ip6_sprintf(ip6buf, &redtgt6), 2371 ifp->if_addrlen, lladdrlen - 2, 2372 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2373 goto bad; 2374 } 2375 2376 /* Validation passed. */ 2377 2378 /* RFC 2461 8.3 */ 2379 nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT, 2380 is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER); 2381 2382 /* 2383 * Install a gateway route in the better-router case or an interface 2384 * route in the on-link-destination case. 2385 */ 2386 { 2387 struct sockaddr_in6 sdst; 2388 struct sockaddr_in6 sgw; 2389 struct sockaddr_in6 ssrc; 2390 struct sockaddr *gw; 2391 int rt_flags; 2392 u_int fibnum; 2393 2394 bzero(&sdst, sizeof(sdst)); 2395 bzero(&ssrc, sizeof(ssrc)); 2396 sdst.sin6_family = ssrc.sin6_family = AF_INET6; 2397 sdst.sin6_len = ssrc.sin6_len = sizeof(struct sockaddr_in6); 2398 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr)); 2399 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr)); 2400 rt_flags = RTF_HOST; 2401 if (is_router) { 2402 bzero(&sgw, sizeof(sgw)); 2403 sgw.sin6_family = AF_INET6; 2404 sgw.sin6_len = sizeof(struct sockaddr_in6); 2405 bcopy(&redtgt6, &sgw.sin6_addr, 2406 sizeof(struct in6_addr)); 2407 gw = (struct sockaddr *)&sgw; 2408 rt_flags |= RTF_GATEWAY; 2409 } else 2410 gw = ifp->if_addr->ifa_addr; 2411 for (fibnum = 0; fibnum < rt_numfibs; fibnum++) 2412 in6_rtredirect((struct sockaddr *)&sdst, gw, 2413 (struct sockaddr *)NULL, rt_flags, 2414 (struct sockaddr *)&ssrc, fibnum); 2415 } 2416 /* finally update cached route in each socket via pfctlinput */ 2417 { 2418 struct sockaddr_in6 sdst; 2419 2420 bzero(&sdst, sizeof(sdst)); 2421 sdst.sin6_family = AF_INET6; 2422 sdst.sin6_len = sizeof(struct sockaddr_in6); 2423 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr)); 2424 pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst); 2425 } 2426 2427 freeit: 2428 m_freem(m); 2429 return; 2430 2431 bad: 2432 ICMP6STAT_INC(icp6s_badredirect); 2433 m_freem(m); 2434 } 2435 2436 void 2437 icmp6_redirect_output(struct mbuf *m0, struct rtentry *rt) 2438 { 2439 struct ifnet *ifp; /* my outgoing interface */ 2440 struct in6_addr *ifp_ll6; 2441 struct in6_addr *router_ll6; 2442 struct ip6_hdr *sip6; /* m0 as struct ip6_hdr */ 2443 struct mbuf *m = NULL; /* newly allocated one */ 2444 struct m_tag *mtag; 2445 struct ip6_hdr *ip6; /* m as struct ip6_hdr */ 2446 struct nd_redirect *nd_rd; 2447 struct llentry *ln = NULL; 2448 size_t maxlen; 2449 u_char *p; 2450 struct ifnet *outif = NULL; 2451 struct sockaddr_in6 src_sa; 2452 2453 icmp6_errcount(ND_REDIRECT, 0); 2454 2455 /* if we are not router, we don't send icmp6 redirect */ 2456 if (!V_ip6_forwarding) 2457 goto fail; 2458 2459 /* sanity check */ 2460 if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp)) 2461 goto fail; 2462 2463 /* 2464 * Address check: 2465 * the source address must identify a neighbor, and 2466 * the destination address must not be a multicast address 2467 * [RFC 2461, sec 8.2] 2468 */ 2469 sip6 = mtod(m0, struct ip6_hdr *); 2470 bzero(&src_sa, sizeof(src_sa)); 2471 src_sa.sin6_family = AF_INET6; 2472 src_sa.sin6_len = sizeof(src_sa); 2473 src_sa.sin6_addr = sip6->ip6_src; 2474 if (nd6_is_addr_neighbor(&src_sa, ifp) == 0) 2475 goto fail; 2476 if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst)) 2477 goto fail; /* what should we do here? */ 2478 2479 /* rate limit */ 2480 if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0)) 2481 goto fail; 2482 2483 /* 2484 * Since we are going to append up to 1280 bytes (= IPV6_MMTU), 2485 * we almost always ask for an mbuf cluster for simplicity. 2486 * (MHLEN < IPV6_MMTU is almost always true) 2487 */ 2488 #if IPV6_MMTU >= MCLBYTES 2489 # error assumption failed about IPV6_MMTU and MCLBYTES 2490 #endif 2491 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 2492 if (m == NULL) 2493 goto fail; 2494 M_SETFIB(m, rt->rt_fibnum); 2495 maxlen = M_TRAILINGSPACE(m); 2496 maxlen = min(IPV6_MMTU, maxlen); 2497 /* just for safety */ 2498 if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) + 2499 ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) { 2500 goto fail; 2501 } 2502 2503 { 2504 /* get ip6 linklocal address for ifp(my outgoing interface). */ 2505 struct in6_ifaddr *ia; 2506 if ((ia = in6ifa_ifpforlinklocal(ifp, 2507 IN6_IFF_NOTREADY| 2508 IN6_IFF_ANYCAST)) == NULL) 2509 goto fail; 2510 ifp_ll6 = &ia->ia_addr.sin6_addr; 2511 /* XXXRW: reference released prematurely. */ 2512 ifa_free(&ia->ia_ifa); 2513 } 2514 2515 /* get ip6 linklocal address for the router. */ 2516 if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) { 2517 struct sockaddr_in6 *sin6; 2518 sin6 = (struct sockaddr_in6 *)rt->rt_gateway; 2519 router_ll6 = &sin6->sin6_addr; 2520 if (!IN6_IS_ADDR_LINKLOCAL(router_ll6)) 2521 router_ll6 = (struct in6_addr *)NULL; 2522 } else 2523 router_ll6 = (struct in6_addr *)NULL; 2524 2525 /* ip6 */ 2526 ip6 = mtod(m, struct ip6_hdr *); 2527 ip6->ip6_flow = 0; 2528 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2529 ip6->ip6_vfc |= IPV6_VERSION; 2530 /* ip6->ip6_plen will be set later */ 2531 ip6->ip6_nxt = IPPROTO_ICMPV6; 2532 ip6->ip6_hlim = 255; 2533 /* ip6->ip6_src must be linklocal addr for my outgoing if. */ 2534 bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr)); 2535 bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr)); 2536 2537 /* ND Redirect */ 2538 nd_rd = (struct nd_redirect *)(ip6 + 1); 2539 nd_rd->nd_rd_type = ND_REDIRECT; 2540 nd_rd->nd_rd_code = 0; 2541 nd_rd->nd_rd_reserved = 0; 2542 if (rt->rt_flags & RTF_GATEWAY) { 2543 /* 2544 * nd_rd->nd_rd_target must be a link-local address in 2545 * better router cases. 2546 */ 2547 if (!router_ll6) 2548 goto fail; 2549 bcopy(router_ll6, &nd_rd->nd_rd_target, 2550 sizeof(nd_rd->nd_rd_target)); 2551 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2552 sizeof(nd_rd->nd_rd_dst)); 2553 } else { 2554 /* make sure redtgt == reddst */ 2555 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target, 2556 sizeof(nd_rd->nd_rd_target)); 2557 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2558 sizeof(nd_rd->nd_rd_dst)); 2559 } 2560 2561 p = (u_char *)(nd_rd + 1); 2562 2563 if (!router_ll6) 2564 goto nolladdropt; 2565 2566 { 2567 /* target lladdr option */ 2568 int len; 2569 struct nd_opt_hdr *nd_opt; 2570 char *lladdr; 2571 2572 IF_AFDATA_RLOCK(ifp); 2573 ln = nd6_lookup(router_ll6, 0, ifp); 2574 IF_AFDATA_RUNLOCK(ifp); 2575 if (ln == NULL) 2576 goto nolladdropt; 2577 2578 len = sizeof(*nd_opt) + ifp->if_addrlen; 2579 len = (len + 7) & ~7; /* round by 8 */ 2580 /* safety check */ 2581 if (len + (p - (u_char *)ip6) > maxlen) 2582 goto nolladdropt; 2583 2584 if (ln->la_flags & LLE_VALID) { 2585 nd_opt = (struct nd_opt_hdr *)p; 2586 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 2587 nd_opt->nd_opt_len = len >> 3; 2588 lladdr = (char *)(nd_opt + 1); 2589 bcopy(ln->ll_addr, lladdr, ifp->if_addrlen); 2590 p += len; 2591 } 2592 } 2593 nolladdropt: 2594 if (ln != NULL) 2595 LLE_RUNLOCK(ln); 2596 2597 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2598 2599 /* just to be safe */ 2600 #ifdef M_DECRYPTED /*not openbsd*/ 2601 if (m0->m_flags & M_DECRYPTED) 2602 goto noredhdropt; 2603 #endif 2604 if (p - (u_char *)ip6 > maxlen) 2605 goto noredhdropt; 2606 2607 { 2608 /* redirected header option */ 2609 int len; 2610 struct nd_opt_rd_hdr *nd_opt_rh; 2611 2612 /* 2613 * compute the maximum size for icmp6 redirect header option. 2614 * XXX room for auth header? 2615 */ 2616 len = maxlen - (p - (u_char *)ip6); 2617 len &= ~7; 2618 2619 /* This is just for simplicity. */ 2620 if (m0->m_pkthdr.len != m0->m_len) { 2621 if (m0->m_next) { 2622 m_freem(m0->m_next); 2623 m0->m_next = NULL; 2624 } 2625 m0->m_pkthdr.len = m0->m_len; 2626 } 2627 2628 /* 2629 * Redirected header option spec (RFC2461 4.6.3) talks nothing 2630 * about padding/truncate rule for the original IP packet. 2631 * From the discussion on IPv6imp in Feb 1999, 2632 * the consensus was: 2633 * - "attach as much as possible" is the goal 2634 * - pad if not aligned (original size can be guessed by 2635 * original ip6 header) 2636 * Following code adds the padding if it is simple enough, 2637 * and truncates if not. 2638 */ 2639 if (m0->m_next || m0->m_pkthdr.len != m0->m_len) 2640 panic("assumption failed in %s:%d", __FILE__, 2641 __LINE__); 2642 2643 if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) { 2644 /* not enough room, truncate */ 2645 m0->m_pkthdr.len = m0->m_len = len - 2646 sizeof(*nd_opt_rh); 2647 } else { 2648 /* enough room, pad or truncate */ 2649 size_t extra; 2650 2651 extra = m0->m_pkthdr.len % 8; 2652 if (extra) { 2653 /* pad if easy enough, truncate if not */ 2654 if (8 - extra <= M_TRAILINGSPACE(m0)) { 2655 /* pad */ 2656 m0->m_len += (8 - extra); 2657 m0->m_pkthdr.len += (8 - extra); 2658 } else { 2659 /* truncate */ 2660 m0->m_pkthdr.len -= extra; 2661 m0->m_len -= extra; 2662 } 2663 } 2664 len = m0->m_pkthdr.len + sizeof(*nd_opt_rh); 2665 m0->m_pkthdr.len = m0->m_len = len - 2666 sizeof(*nd_opt_rh); 2667 } 2668 2669 nd_opt_rh = (struct nd_opt_rd_hdr *)p; 2670 bzero(nd_opt_rh, sizeof(*nd_opt_rh)); 2671 nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER; 2672 nd_opt_rh->nd_opt_rh_len = len >> 3; 2673 p += sizeof(*nd_opt_rh); 2674 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2675 2676 /* connect m0 to m */ 2677 m_tag_delete_chain(m0, NULL); 2678 m0->m_flags &= ~M_PKTHDR; 2679 m->m_next = m0; 2680 m->m_pkthdr.len = m->m_len + m0->m_len; 2681 m0 = NULL; 2682 } 2683 noredhdropt:; 2684 if (m0) { 2685 m_freem(m0); 2686 m0 = NULL; 2687 } 2688 2689 /* XXX: clear embedded link IDs in the inner header */ 2690 in6_clearscope(&sip6->ip6_src); 2691 in6_clearscope(&sip6->ip6_dst); 2692 in6_clearscope(&nd_rd->nd_rd_target); 2693 in6_clearscope(&nd_rd->nd_rd_dst); 2694 2695 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr)); 2696 2697 nd_rd->nd_rd_cksum = 0; 2698 nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2699 sizeof(*ip6), ntohs(ip6->ip6_plen)); 2700 2701 if (send_sendso_input_hook != NULL) { 2702 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, sizeof(unsigned short), 2703 M_NOWAIT); 2704 if (mtag == NULL) 2705 goto fail; 2706 *(unsigned short *)(mtag + 1) = nd_rd->nd_rd_type; 2707 m_tag_prepend(m, mtag); 2708 } 2709 2710 /* send the packet to outside... */ 2711 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2712 if (outif) { 2713 icmp6_ifstat_inc(outif, ifs6_out_msg); 2714 icmp6_ifstat_inc(outif, ifs6_out_redirect); 2715 } 2716 ICMP6STAT_INC(icp6s_outhist[ND_REDIRECT]); 2717 2718 return; 2719 2720 fail: 2721 if (m) 2722 m_freem(m); 2723 if (m0) 2724 m_freem(m0); 2725 } 2726 2727 /* 2728 * ICMPv6 socket option processing. 2729 */ 2730 int 2731 icmp6_ctloutput(struct socket *so, struct sockopt *sopt) 2732 { 2733 int error = 0; 2734 int optlen; 2735 struct inpcb *inp = sotoinpcb(so); 2736 int level, op, optname; 2737 2738 if (sopt) { 2739 level = sopt->sopt_level; 2740 op = sopt->sopt_dir; 2741 optname = sopt->sopt_name; 2742 optlen = sopt->sopt_valsize; 2743 } else 2744 level = op = optname = optlen = 0; 2745 2746 if (level != IPPROTO_ICMPV6) { 2747 return EINVAL; 2748 } 2749 2750 switch (op) { 2751 case PRCO_SETOPT: 2752 switch (optname) { 2753 case ICMP6_FILTER: 2754 { 2755 struct icmp6_filter ic6f; 2756 2757 if (optlen != sizeof(ic6f)) { 2758 error = EMSGSIZE; 2759 break; 2760 } 2761 error = sooptcopyin(sopt, &ic6f, optlen, optlen); 2762 if (error == 0) { 2763 INP_WLOCK(inp); 2764 *inp->in6p_icmp6filt = ic6f; 2765 INP_WUNLOCK(inp); 2766 } 2767 break; 2768 } 2769 2770 default: 2771 error = ENOPROTOOPT; 2772 break; 2773 } 2774 break; 2775 2776 case PRCO_GETOPT: 2777 switch (optname) { 2778 case ICMP6_FILTER: 2779 { 2780 struct icmp6_filter ic6f; 2781 2782 INP_RLOCK(inp); 2783 ic6f = *inp->in6p_icmp6filt; 2784 INP_RUNLOCK(inp); 2785 error = sooptcopyout(sopt, &ic6f, sizeof(ic6f)); 2786 break; 2787 } 2788 2789 default: 2790 error = ENOPROTOOPT; 2791 break; 2792 } 2793 break; 2794 } 2795 2796 return (error); 2797 } 2798 2799 /* 2800 * Perform rate limit check. 2801 * Returns 0 if it is okay to send the icmp6 packet. 2802 * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate 2803 * limitation. 2804 * 2805 * XXX per-destination/type check necessary? 2806 * 2807 * dst - not used at this moment 2808 * type - not used at this moment 2809 * code - not used at this moment 2810 */ 2811 static int 2812 icmp6_ratelimit(const struct in6_addr *dst, const int type, 2813 const int code) 2814 { 2815 int ret; 2816 2817 ret = 0; /* okay to send */ 2818 2819 /* PPS limit */ 2820 if (!ppsratecheck(&V_icmp6errppslim_last, &V_icmp6errpps_count, 2821 V_icmp6errppslim)) { 2822 /* The packet is subject to rate limit */ 2823 ret++; 2824 } 2825 2826 return ret; 2827 } 2828