Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/netinet6/icmp6.c
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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: releng/12.0/sys/netinet6/icmp6.c 338831 2018-09-20 15:45:53Z bz $"); 67 68 #define MBUF_PRIVATE /* XXXRW: Optimisation tries to avoid M_EXT mbufs */ 69 70 #include "opt_inet.h" 71 #include "opt_inet6.h" 72 73 #include <sys/param.h> 74 #include <sys/domain.h> 75 #include <sys/jail.h> 76 #include <sys/kernel.h> 77 #include <sys/lock.h> 78 #include <sys/malloc.h> 79 #include <sys/mbuf.h> 80 #include <sys/proc.h> 81 #include <sys/protosw.h> 82 #include <sys/signalvar.h> 83 #include <sys/socket.h> 84 #include <sys/socketvar.h> 85 #include <sys/sx.h> 86 #include <sys/syslog.h> 87 #include <sys/systm.h> 88 #include <sys/time.h> 89 90 #include <net/if.h> 91 #include <net/if_var.h> 92 #include <net/if_dl.h> 93 #include <net/if_llatbl.h> 94 #include <net/if_types.h> 95 #include <net/route.h> 96 #include <net/vnet.h> 97 98 #include <netinet/in.h> 99 #include <netinet/in_pcb.h> 100 #include <netinet/in_var.h> 101 #include <netinet/ip6.h> 102 #include <netinet/icmp6.h> 103 #include <netinet/tcp_var.h> 104 105 #include <netinet6/in6_fib.h> 106 #include <netinet6/in6_ifattach.h> 107 #include <netinet6/in6_pcb.h> 108 #include <netinet6/ip6protosw.h> 109 #include <netinet6/ip6_var.h> 110 #include <netinet6/scope6_var.h> 111 #include <netinet6/mld6_var.h> 112 #include <netinet6/nd6.h> 113 #include <netinet6/send.h> 114 115 extern struct domain inet6domain; 116 117 VNET_PCPUSTAT_DEFINE(struct icmp6stat, icmp6stat); 118 VNET_PCPUSTAT_SYSINIT(icmp6stat); 119 120 #ifdef VIMAGE 121 VNET_PCPUSTAT_SYSUNINIT(icmp6stat); 122 #endif /* VIMAGE */ 123 124 VNET_DECLARE(struct inpcbinfo, ripcbinfo); 125 VNET_DECLARE(struct inpcbhead, ripcb); 126 VNET_DECLARE(int, icmp6errppslim); 127 VNET_DEFINE_STATIC(int, icmp6errpps_count) = 0; 128 VNET_DEFINE_STATIC(struct timeval, icmp6errppslim_last); 129 VNET_DECLARE(int, icmp6_nodeinfo); 130 131 #define V_ripcbinfo VNET(ripcbinfo) 132 #define V_ripcb VNET(ripcb) 133 #define V_icmp6errppslim VNET(icmp6errppslim) 134 #define V_icmp6errpps_count VNET(icmp6errpps_count) 135 #define V_icmp6errppslim_last VNET(icmp6errppslim_last) 136 #define V_icmp6_nodeinfo VNET(icmp6_nodeinfo) 137 138 static void icmp6_errcount(int, int); 139 static int icmp6_rip6_input(struct mbuf **, int); 140 static int icmp6_ratelimit(const struct in6_addr *, const int, const int); 141 static const char *icmp6_redirect_diag(struct in6_addr *, 142 struct in6_addr *, struct in6_addr *); 143 static struct mbuf *ni6_input(struct mbuf *, int); 144 static struct mbuf *ni6_nametodns(const char *, int, int); 145 static int ni6_dnsmatch(const char *, int, const char *, int); 146 static int ni6_addrs(struct icmp6_nodeinfo *, struct mbuf *, 147 struct ifnet **, struct in6_addr *); 148 static int ni6_store_addrs(struct icmp6_nodeinfo *, struct icmp6_nodeinfo *, 149 struct ifnet *, int); 150 static int icmp6_notify_error(struct mbuf **, int, int, int); 151 152 /* 153 * Kernel module interface for updating icmp6stat. The argument is an index 154 * into icmp6stat treated as an array of u_quad_t. While this encodes the 155 * general layout of icmp6stat into the caller, it doesn't encode its 156 * location, so that future changes to add, for example, per-CPU stats 157 * support won't cause binary compatibility problems for kernel modules. 158 */ 159 void 160 kmod_icmp6stat_inc(int statnum) 161 { 162 163 counter_u64_add(VNET(icmp6stat)[statnum], 1); 164 } 165 166 static void 167 icmp6_errcount(int type, int code) 168 { 169 switch (type) { 170 case ICMP6_DST_UNREACH: 171 switch (code) { 172 case ICMP6_DST_UNREACH_NOROUTE: 173 ICMP6STAT_INC(icp6s_odst_unreach_noroute); 174 return; 175 case ICMP6_DST_UNREACH_ADMIN: 176 ICMP6STAT_INC(icp6s_odst_unreach_admin); 177 return; 178 case ICMP6_DST_UNREACH_BEYONDSCOPE: 179 ICMP6STAT_INC(icp6s_odst_unreach_beyondscope); 180 return; 181 case ICMP6_DST_UNREACH_ADDR: 182 ICMP6STAT_INC(icp6s_odst_unreach_addr); 183 return; 184 case ICMP6_DST_UNREACH_NOPORT: 185 ICMP6STAT_INC(icp6s_odst_unreach_noport); 186 return; 187 } 188 break; 189 case ICMP6_PACKET_TOO_BIG: 190 ICMP6STAT_INC(icp6s_opacket_too_big); 191 return; 192 case ICMP6_TIME_EXCEEDED: 193 switch (code) { 194 case ICMP6_TIME_EXCEED_TRANSIT: 195 ICMP6STAT_INC(icp6s_otime_exceed_transit); 196 return; 197 case ICMP6_TIME_EXCEED_REASSEMBLY: 198 ICMP6STAT_INC(icp6s_otime_exceed_reassembly); 199 return; 200 } 201 break; 202 case ICMP6_PARAM_PROB: 203 switch (code) { 204 case ICMP6_PARAMPROB_HEADER: 205 ICMP6STAT_INC(icp6s_oparamprob_header); 206 return; 207 case ICMP6_PARAMPROB_NEXTHEADER: 208 ICMP6STAT_INC(icp6s_oparamprob_nextheader); 209 return; 210 case ICMP6_PARAMPROB_OPTION: 211 ICMP6STAT_INC(icp6s_oparamprob_option); 212 return; 213 } 214 break; 215 case ND_REDIRECT: 216 ICMP6STAT_INC(icp6s_oredirect); 217 return; 218 } 219 ICMP6STAT_INC(icp6s_ounknown); 220 } 221 222 /* 223 * A wrapper function for icmp6_error() necessary when the erroneous packet 224 * may not contain enough scope zone information. 225 */ 226 void 227 icmp6_error2(struct mbuf *m, int type, int code, int param, 228 struct ifnet *ifp) 229 { 230 struct ip6_hdr *ip6; 231 232 if (ifp == NULL) 233 return; 234 235 #ifndef PULLDOWN_TEST 236 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), ); 237 #else 238 if (m->m_len < sizeof(struct ip6_hdr)) { 239 m = m_pullup(m, sizeof(struct ip6_hdr)); 240 if (m == NULL) 241 return; 242 } 243 #endif 244 245 ip6 = mtod(m, struct ip6_hdr *); 246 247 if (in6_setscope(&ip6->ip6_src, ifp, NULL) != 0) 248 return; 249 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0) 250 return; 251 252 icmp6_error(m, type, code, param); 253 } 254 255 /* 256 * Generate an error packet of type error in response to bad IP6 packet. 257 */ 258 void 259 icmp6_error(struct mbuf *m, int type, int code, int param) 260 { 261 struct ip6_hdr *oip6, *nip6; 262 struct icmp6_hdr *icmp6; 263 u_int preplen; 264 int off; 265 int nxt; 266 267 ICMP6STAT_INC(icp6s_error); 268 269 /* count per-type-code statistics */ 270 icmp6_errcount(type, code); 271 272 #ifdef M_DECRYPTED /*not openbsd*/ 273 if (m->m_flags & M_DECRYPTED) { 274 ICMP6STAT_INC(icp6s_canterror); 275 goto freeit; 276 } 277 #endif 278 279 #ifndef PULLDOWN_TEST 280 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), ); 281 #else 282 if (m->m_len < sizeof(struct ip6_hdr)) { 283 m = m_pullup(m, sizeof(struct ip6_hdr)); 284 if (m == NULL) 285 return; 286 } 287 #endif 288 oip6 = mtod(m, struct ip6_hdr *); 289 290 /* 291 * If the destination address of the erroneous packet is a multicast 292 * address, or the packet was sent using link-layer multicast, 293 * we should basically suppress sending an error (RFC 2463, Section 294 * 2.4). 295 * We have two exceptions (the item e.2 in that section): 296 * - the Packet Too Big message can be sent for path MTU discovery. 297 * - the Parameter Problem Message that can be allowed an icmp6 error 298 * in the option type field. This check has been done in 299 * ip6_unknown_opt(), so we can just check the type and code. 300 */ 301 if ((m->m_flags & (M_BCAST|M_MCAST) || 302 IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) && 303 (type != ICMP6_PACKET_TOO_BIG && 304 (type != ICMP6_PARAM_PROB || 305 code != ICMP6_PARAMPROB_OPTION))) 306 goto freeit; 307 308 /* 309 * RFC 2463, 2.4 (e.5): source address check. 310 * XXX: the case of anycast source? 311 */ 312 if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) || 313 IN6_IS_ADDR_MULTICAST(&oip6->ip6_src)) 314 goto freeit; 315 316 /* 317 * If we are about to send ICMPv6 against ICMPv6 error/redirect, 318 * don't do it. 319 */ 320 nxt = -1; 321 off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt); 322 if (off >= 0 && nxt == IPPROTO_ICMPV6) { 323 struct icmp6_hdr *icp; 324 325 #ifndef PULLDOWN_TEST 326 IP6_EXTHDR_CHECK(m, 0, off + sizeof(struct icmp6_hdr), ); 327 icp = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 328 #else 329 IP6_EXTHDR_GET(icp, struct icmp6_hdr *, m, off, 330 sizeof(*icp)); 331 if (icp == NULL) { 332 ICMP6STAT_INC(icp6s_tooshort); 333 return; 334 } 335 #endif 336 if (icp->icmp6_type < ICMP6_ECHO_REQUEST || 337 icp->icmp6_type == ND_REDIRECT) { 338 /* 339 * ICMPv6 error 340 * Special case: for redirect (which is 341 * informational) we must not send icmp6 error. 342 */ 343 ICMP6STAT_INC(icp6s_canterror); 344 goto freeit; 345 } else { 346 /* ICMPv6 informational - send the error */ 347 } 348 } else { 349 /* non-ICMPv6 - send the error */ 350 } 351 352 oip6 = mtod(m, struct ip6_hdr *); /* adjust pointer */ 353 354 /* Finally, do rate limitation check. */ 355 if (icmp6_ratelimit(&oip6->ip6_src, type, code)) { 356 ICMP6STAT_INC(icp6s_toofreq); 357 goto freeit; 358 } 359 360 /* 361 * OK, ICMP6 can be generated. 362 */ 363 364 if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN) 365 m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len); 366 367 preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 368 M_PREPEND(m, preplen, M_NOWAIT); /* FIB is also copied over. */ 369 if (m == NULL) { 370 nd6log((LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__)); 371 return; 372 } 373 374 nip6 = mtod(m, struct ip6_hdr *); 375 nip6->ip6_src = oip6->ip6_src; 376 nip6->ip6_dst = oip6->ip6_dst; 377 378 in6_clearscope(&oip6->ip6_src); 379 in6_clearscope(&oip6->ip6_dst); 380 381 icmp6 = (struct icmp6_hdr *)(nip6 + 1); 382 icmp6->icmp6_type = type; 383 icmp6->icmp6_code = code; 384 icmp6->icmp6_pptr = htonl((u_int32_t)param); 385 386 ICMP6STAT_INC(icp6s_outhist[type]); 387 icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */ 388 389 return; 390 391 freeit: 392 /* 393 * If we can't tell whether or not we can generate ICMP6, free it. 394 */ 395 m_freem(m); 396 } 397 398 /* 399 * Process a received ICMP6 message. 400 */ 401 int 402 icmp6_input(struct mbuf **mp, int *offp, int proto) 403 { 404 struct mbuf *m = *mp, *n; 405 struct ifnet *ifp; 406 struct ip6_hdr *ip6, *nip6; 407 struct icmp6_hdr *icmp6, *nicmp6; 408 int off = *offp; 409 int icmp6len = m->m_pkthdr.len - *offp; 410 int code, sum, noff; 411 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 412 int ip6len, error; 413 414 ifp = m->m_pkthdr.rcvif; 415 416 #ifndef PULLDOWN_TEST 417 IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_hdr), IPPROTO_DONE); 418 /* m might change if M_LOOP. So, call mtod after this */ 419 #endif 420 421 /* 422 * Locate icmp6 structure in mbuf, and check 423 * that not corrupted and of at least minimum length 424 */ 425 426 ip6 = mtod(m, struct ip6_hdr *); 427 ip6len = sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen); 428 if (icmp6len < sizeof(struct icmp6_hdr)) { 429 ICMP6STAT_INC(icp6s_tooshort); 430 goto freeit; 431 } 432 433 /* 434 * Check multicast group membership. 435 * Note: SSM filters are not applied for ICMPv6 traffic. 436 */ 437 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 438 struct in6_multi *inm; 439 440 inm = in6m_lookup(ifp, &ip6->ip6_dst); 441 if (inm == NULL) { 442 IP6STAT_INC(ip6s_notmember); 443 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 444 goto freeit; 445 } 446 } 447 448 /* 449 * calculate the checksum 450 */ 451 #ifndef PULLDOWN_TEST 452 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off); 453 #else 454 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6)); 455 if (icmp6 == NULL) { 456 ICMP6STAT_INC(icp6s_tooshort); 457 return IPPROTO_DONE; 458 } 459 #endif 460 code = icmp6->icmp6_code; 461 462 if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) { 463 nd6log((LOG_ERR, 464 "ICMP6 checksum error(%d|%x) %s\n", 465 icmp6->icmp6_type, sum, 466 ip6_sprintf(ip6bufs, &ip6->ip6_src))); 467 ICMP6STAT_INC(icp6s_checksum); 468 goto freeit; 469 } 470 471 ICMP6STAT_INC(icp6s_inhist[icmp6->icmp6_type]); 472 icmp6_ifstat_inc(ifp, ifs6_in_msg); 473 if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK) 474 icmp6_ifstat_inc(ifp, ifs6_in_error); 475 476 switch (icmp6->icmp6_type) { 477 case ICMP6_DST_UNREACH: 478 icmp6_ifstat_inc(ifp, ifs6_in_dstunreach); 479 switch (code) { 480 case ICMP6_DST_UNREACH_NOROUTE: 481 case ICMP6_DST_UNREACH_ADDR: /* PRC_HOSTDEAD is a DOS */ 482 code = PRC_UNREACH_NET; 483 break; 484 case ICMP6_DST_UNREACH_ADMIN: 485 icmp6_ifstat_inc(ifp, ifs6_in_adminprohib); 486 code = PRC_UNREACH_ADMIN_PROHIB; 487 break; 488 case ICMP6_DST_UNREACH_BEYONDSCOPE: 489 /* I mean "source address was incorrect." */ 490 code = PRC_PARAMPROB; 491 break; 492 case ICMP6_DST_UNREACH_NOPORT: 493 code = PRC_UNREACH_PORT; 494 break; 495 default: 496 goto badcode; 497 } 498 goto deliver; 499 break; 500 501 case ICMP6_PACKET_TOO_BIG: 502 icmp6_ifstat_inc(ifp, ifs6_in_pkttoobig); 503 504 /* validation is made in icmp6_mtudisc_update */ 505 506 code = PRC_MSGSIZE; 507 508 /* 509 * Updating the path MTU will be done after examining 510 * intermediate extension headers. 511 */ 512 goto deliver; 513 break; 514 515 case ICMP6_TIME_EXCEEDED: 516 icmp6_ifstat_inc(ifp, ifs6_in_timeexceed); 517 switch (code) { 518 case ICMP6_TIME_EXCEED_TRANSIT: 519 code = PRC_TIMXCEED_INTRANS; 520 break; 521 case ICMP6_TIME_EXCEED_REASSEMBLY: 522 code = PRC_TIMXCEED_REASS; 523 break; 524 default: 525 goto badcode; 526 } 527 goto deliver; 528 break; 529 530 case ICMP6_PARAM_PROB: 531 icmp6_ifstat_inc(ifp, ifs6_in_paramprob); 532 switch (code) { 533 case ICMP6_PARAMPROB_NEXTHEADER: 534 code = PRC_UNREACH_PROTOCOL; 535 break; 536 case ICMP6_PARAMPROB_HEADER: 537 case ICMP6_PARAMPROB_OPTION: 538 code = PRC_PARAMPROB; 539 break; 540 default: 541 goto badcode; 542 } 543 goto deliver; 544 break; 545 546 case ICMP6_ECHO_REQUEST: 547 icmp6_ifstat_inc(ifp, ifs6_in_echo); 548 if (code != 0) 549 goto badcode; 550 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) { 551 /* Give up remote */ 552 break; 553 } 554 if (!M_WRITABLE(n) 555 || n->m_len < off + sizeof(struct icmp6_hdr)) { 556 struct mbuf *n0 = n; 557 int n0len; 558 559 CTASSERT(sizeof(*nip6) + sizeof(*nicmp6) <= MHLEN); 560 n = m_gethdr(M_NOWAIT, n0->m_type); 561 if (n == NULL) { 562 /* Give up remote */ 563 m_freem(n0); 564 break; 565 } 566 567 m_move_pkthdr(n, n0); /* FIB copied. */ 568 n0len = n0->m_pkthdr.len; /* save for use below */ 569 /* 570 * Copy IPv6 and ICMPv6 only. 571 */ 572 nip6 = mtod(n, struct ip6_hdr *); 573 bcopy(ip6, nip6, sizeof(struct ip6_hdr)); 574 nicmp6 = (struct icmp6_hdr *)(nip6 + 1); 575 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr)); 576 noff = sizeof(struct ip6_hdr); 577 /* new mbuf contains only ipv6+icmpv6 headers */ 578 n->m_len = noff + sizeof(struct icmp6_hdr); 579 /* 580 * Adjust mbuf. ip6_plen will be adjusted in 581 * ip6_output(). 582 */ 583 m_adj(n0, off + sizeof(struct icmp6_hdr)); 584 /* recalculate complete packet size */ 585 n->m_pkthdr.len = n0len + (noff - off); 586 n->m_next = n0; 587 } else { 588 IP6_EXTHDR_GET(nicmp6, struct icmp6_hdr *, n, off, 589 sizeof(*nicmp6)); 590 noff = off; 591 } 592 if (n) { 593 nicmp6->icmp6_type = ICMP6_ECHO_REPLY; 594 nicmp6->icmp6_code = 0; 595 ICMP6STAT_INC(icp6s_reflect); 596 ICMP6STAT_INC(icp6s_outhist[ICMP6_ECHO_REPLY]); 597 icmp6_reflect(n, noff); 598 } 599 break; 600 601 case ICMP6_ECHO_REPLY: 602 icmp6_ifstat_inc(ifp, ifs6_in_echoreply); 603 if (code != 0) 604 goto badcode; 605 break; 606 607 case MLD_LISTENER_QUERY: 608 case MLD_LISTENER_REPORT: 609 case MLD_LISTENER_DONE: 610 case MLDV2_LISTENER_REPORT: 611 /* 612 * Drop MLD traffic which is not link-local, has a hop limit 613 * of greater than 1 hop, or which does not have the 614 * IPv6 HBH Router Alert option. 615 * As IPv6 HBH options are stripped in ip6_input() we must 616 * check an mbuf header flag. 617 * XXX Should we also sanity check that these messages 618 * were directed to a link-local multicast prefix? 619 */ 620 if ((ip6->ip6_hlim != 1) || (m->m_flags & M_RTALERT_MLD) == 0) 621 goto freeit; 622 if (mld_input(m, off, icmp6len) != 0) 623 return (IPPROTO_DONE); 624 /* m stays. */ 625 break; 626 627 case ICMP6_WRUREQUEST: /* ICMP6_FQDN_QUERY */ 628 { 629 enum { WRU, FQDN } mode; 630 631 if (!V_icmp6_nodeinfo) 632 break; 633 634 if (icmp6len == sizeof(struct icmp6_hdr) + 4) 635 mode = WRU; 636 else if (icmp6len >= sizeof(struct icmp6_nodeinfo)) 637 mode = FQDN; 638 else 639 goto badlen; 640 641 if (mode == FQDN) { 642 #ifndef PULLDOWN_TEST 643 IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_nodeinfo), 644 IPPROTO_DONE); 645 #endif 646 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 647 if (n) 648 n = ni6_input(n, off); 649 /* XXX meaningless if n == NULL */ 650 noff = sizeof(struct ip6_hdr); 651 } else { 652 struct prison *pr; 653 u_char *p; 654 int maxhlen, hlen; 655 656 /* 657 * XXX: this combination of flags is pointless, 658 * but should we keep this for compatibility? 659 */ 660 if ((V_icmp6_nodeinfo & (ICMP6_NODEINFO_FQDNOK | 661 ICMP6_NODEINFO_TMPADDROK)) != 662 (ICMP6_NODEINFO_FQDNOK | ICMP6_NODEINFO_TMPADDROK)) 663 break; 664 665 if (code != 0) 666 goto badcode; 667 668 CTASSERT(sizeof(*nip6) + sizeof(*nicmp6) + 4 <= MHLEN); 669 n = m_gethdr(M_NOWAIT, m->m_type); 670 if (n == NULL) { 671 /* Give up remote */ 672 break; 673 } 674 if (!m_dup_pkthdr(n, m, M_NOWAIT)) { 675 /* 676 * Previous code did a blind M_COPY_PKTHDR 677 * and said "just for rcvif". If true, then 678 * we could tolerate the dup failing (due to 679 * the deep copy of the tag chain). For now 680 * be conservative and just fail. 681 */ 682 m_free(n); 683 n = NULL; 684 break; 685 } 686 maxhlen = M_TRAILINGSPACE(n) - 687 (sizeof(*nip6) + sizeof(*nicmp6) + 4); 688 pr = curthread->td_ucred->cr_prison; 689 mtx_lock(&pr->pr_mtx); 690 hlen = strlen(pr->pr_hostname); 691 if (maxhlen > hlen) 692 maxhlen = hlen; 693 /* 694 * Copy IPv6 and ICMPv6 only. 695 */ 696 nip6 = mtod(n, struct ip6_hdr *); 697 bcopy(ip6, nip6, sizeof(struct ip6_hdr)); 698 nicmp6 = (struct icmp6_hdr *)(nip6 + 1); 699 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr)); 700 p = (u_char *)(nicmp6 + 1); 701 bzero(p, 4); 702 /* meaningless TTL */ 703 bcopy(pr->pr_hostname, p + 4, maxhlen); 704 mtx_unlock(&pr->pr_mtx); 705 noff = sizeof(struct ip6_hdr); 706 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + 707 sizeof(struct icmp6_hdr) + 4 + maxhlen; 708 nicmp6->icmp6_type = ICMP6_WRUREPLY; 709 nicmp6->icmp6_code = 0; 710 } 711 if (n) { 712 ICMP6STAT_INC(icp6s_reflect); 713 ICMP6STAT_INC(icp6s_outhist[ICMP6_WRUREPLY]); 714 icmp6_reflect(n, noff); 715 } 716 break; 717 } 718 719 case ICMP6_WRUREPLY: 720 if (code != 0) 721 goto badcode; 722 break; 723 724 case ND_ROUTER_SOLICIT: 725 icmp6_ifstat_inc(ifp, ifs6_in_routersolicit); 726 if (code != 0) 727 goto badcode; 728 if (icmp6len < sizeof(struct nd_router_solicit)) 729 goto badlen; 730 if (send_sendso_input_hook != NULL) { 731 IP6_EXTHDR_CHECK(m, off, icmp6len, IPPROTO_DONE); 732 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 733 if (error == 0) { 734 m = NULL; 735 goto freeit; 736 } 737 } 738 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 739 nd6_rs_input(m, off, icmp6len); 740 m = n; 741 if (m == NULL) 742 goto freeit; 743 break; 744 745 case ND_ROUTER_ADVERT: 746 icmp6_ifstat_inc(ifp, ifs6_in_routeradvert); 747 if (code != 0) 748 goto badcode; 749 if (icmp6len < sizeof(struct nd_router_advert)) 750 goto badlen; 751 if (send_sendso_input_hook != NULL) { 752 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 753 if (error == 0) { 754 m = NULL; 755 goto freeit; 756 } 757 } 758 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 759 nd6_ra_input(m, off, icmp6len); 760 m = n; 761 if (m == NULL) 762 goto freeit; 763 break; 764 765 case ND_NEIGHBOR_SOLICIT: 766 icmp6_ifstat_inc(ifp, ifs6_in_neighborsolicit); 767 if (code != 0) 768 goto badcode; 769 if (icmp6len < sizeof(struct nd_neighbor_solicit)) 770 goto badlen; 771 if (send_sendso_input_hook != NULL) { 772 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 773 if (error == 0) { 774 m = NULL; 775 goto freeit; 776 } 777 } 778 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 779 nd6_ns_input(m, off, icmp6len); 780 m = n; 781 if (m == NULL) 782 goto freeit; 783 break; 784 785 case ND_NEIGHBOR_ADVERT: 786 icmp6_ifstat_inc(ifp, ifs6_in_neighboradvert); 787 if (code != 0) 788 goto badcode; 789 if (icmp6len < sizeof(struct nd_neighbor_advert)) 790 goto badlen; 791 if (send_sendso_input_hook != NULL) { 792 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 793 if (error == 0) { 794 m = NULL; 795 goto freeit; 796 } 797 } 798 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 799 nd6_na_input(m, off, icmp6len); 800 m = n; 801 if (m == NULL) 802 goto freeit; 803 break; 804 805 case ND_REDIRECT: 806 icmp6_ifstat_inc(ifp, ifs6_in_redirect); 807 if (code != 0) 808 goto badcode; 809 if (icmp6len < sizeof(struct nd_redirect)) 810 goto badlen; 811 if (send_sendso_input_hook != NULL) { 812 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 813 if (error == 0) { 814 m = NULL; 815 goto freeit; 816 } 817 } 818 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 819 icmp6_redirect_input(m, off); 820 m = n; 821 if (m == NULL) 822 goto freeit; 823 break; 824 825 case ICMP6_ROUTER_RENUMBERING: 826 if (code != ICMP6_ROUTER_RENUMBERING_COMMAND && 827 code != ICMP6_ROUTER_RENUMBERING_RESULT) 828 goto badcode; 829 if (icmp6len < sizeof(struct icmp6_router_renum)) 830 goto badlen; 831 break; 832 833 default: 834 nd6log((LOG_DEBUG, 835 "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n", 836 icmp6->icmp6_type, ip6_sprintf(ip6bufs, &ip6->ip6_src), 837 ip6_sprintf(ip6bufd, &ip6->ip6_dst), 838 ifp ? ifp->if_index : 0)); 839 if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) { 840 /* ICMPv6 error: MUST deliver it by spec... */ 841 code = PRC_NCMDS; 842 /* deliver */ 843 } else { 844 /* ICMPv6 informational: MUST not deliver */ 845 break; 846 } 847 deliver: 848 if (icmp6_notify_error(&m, off, icmp6len, code) != 0) { 849 /* In this case, m should've been freed. */ 850 return (IPPROTO_DONE); 851 } 852 break; 853 854 badcode: 855 ICMP6STAT_INC(icp6s_badcode); 856 break; 857 858 badlen: 859 ICMP6STAT_INC(icp6s_badlen); 860 break; 861 } 862 863 /* deliver the packet to appropriate sockets */ 864 icmp6_rip6_input(&m, *offp); 865 866 return IPPROTO_DONE; 867 868 freeit: 869 m_freem(m); 870 return IPPROTO_DONE; 871 } 872 873 static int 874 icmp6_notify_error(struct mbuf **mp, int off, int icmp6len, int code) 875 { 876 struct mbuf *m = *mp; 877 struct icmp6_hdr *icmp6; 878 struct ip6_hdr *eip6; 879 u_int32_t notifymtu; 880 struct sockaddr_in6 icmp6src, icmp6dst; 881 882 if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) { 883 ICMP6STAT_INC(icp6s_tooshort); 884 goto freeit; 885 } 886 #ifndef PULLDOWN_TEST 887 IP6_EXTHDR_CHECK(m, off, 888 sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr), -1); 889 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 890 #else 891 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, 892 sizeof(*icmp6) + sizeof(struct ip6_hdr)); 893 if (icmp6 == NULL) { 894 ICMP6STAT_INC(icp6s_tooshort); 895 return (-1); 896 } 897 #endif 898 eip6 = (struct ip6_hdr *)(icmp6 + 1); 899 900 /* Detect the upper level protocol */ 901 { 902 void (*ctlfunc)(int, struct sockaddr *, void *); 903 u_int8_t nxt = eip6->ip6_nxt; 904 int eoff = off + sizeof(struct icmp6_hdr) + 905 sizeof(struct ip6_hdr); 906 struct ip6ctlparam ip6cp; 907 struct in6_addr *finaldst = NULL; 908 int icmp6type = icmp6->icmp6_type; 909 struct ip6_frag *fh; 910 struct ip6_rthdr *rth; 911 struct ip6_rthdr0 *rth0; 912 int rthlen; 913 914 while (1) { /* XXX: should avoid infinite loop explicitly? */ 915 struct ip6_ext *eh; 916 917 switch (nxt) { 918 case IPPROTO_HOPOPTS: 919 case IPPROTO_DSTOPTS: 920 case IPPROTO_AH: 921 #ifndef PULLDOWN_TEST 922 IP6_EXTHDR_CHECK(m, 0, 923 eoff + sizeof(struct ip6_ext), -1); 924 eh = (struct ip6_ext *)(mtod(m, caddr_t) + eoff); 925 #else 926 IP6_EXTHDR_GET(eh, struct ip6_ext *, m, 927 eoff, sizeof(*eh)); 928 if (eh == NULL) { 929 ICMP6STAT_INC(icp6s_tooshort); 930 return (-1); 931 } 932 #endif 933 934 if (nxt == IPPROTO_AH) 935 eoff += (eh->ip6e_len + 2) << 2; 936 else 937 eoff += (eh->ip6e_len + 1) << 3; 938 nxt = eh->ip6e_nxt; 939 break; 940 case IPPROTO_ROUTING: 941 /* 942 * When the erroneous packet contains a 943 * routing header, we should examine the 944 * header to determine the final destination. 945 * Otherwise, we can't properly update 946 * information that depends on the final 947 * destination (e.g. path MTU). 948 */ 949 #ifndef PULLDOWN_TEST 950 IP6_EXTHDR_CHECK(m, 0, eoff + sizeof(*rth), -1); 951 rth = (struct ip6_rthdr *) 952 (mtod(m, caddr_t) + eoff); 953 #else 954 IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m, 955 eoff, sizeof(*rth)); 956 if (rth == NULL) { 957 ICMP6STAT_INC(icp6s_tooshort); 958 return (-1); 959 } 960 #endif 961 rthlen = (rth->ip6r_len + 1) << 3; 962 /* 963 * XXX: currently there is no 964 * officially defined type other 965 * than type-0. 966 * Note that if the segment left field 967 * is 0, all intermediate hops must 968 * have been passed. 969 */ 970 if (rth->ip6r_segleft && 971 rth->ip6r_type == IPV6_RTHDR_TYPE_0) { 972 int hops; 973 974 #ifndef PULLDOWN_TEST 975 IP6_EXTHDR_CHECK(m, 0, eoff + rthlen, -1); 976 rth0 = (struct ip6_rthdr0 *) 977 (mtod(m, caddr_t) + eoff); 978 #else 979 IP6_EXTHDR_GET(rth0, 980 struct ip6_rthdr0 *, m, 981 eoff, rthlen); 982 if (rth0 == NULL) { 983 ICMP6STAT_INC(icp6s_tooshort); 984 return (-1); 985 } 986 #endif 987 /* just ignore a bogus header */ 988 if ((rth0->ip6r0_len % 2) == 0 && 989 (hops = rth0->ip6r0_len/2)) 990 finaldst = (struct in6_addr *)(rth0 + 1) + (hops - 1); 991 } 992 eoff += rthlen; 993 nxt = rth->ip6r_nxt; 994 break; 995 case IPPROTO_FRAGMENT: 996 #ifndef PULLDOWN_TEST 997 IP6_EXTHDR_CHECK(m, 0, eoff + 998 sizeof(struct ip6_frag), -1); 999 fh = (struct ip6_frag *)(mtod(m, caddr_t) + 1000 eoff); 1001 #else 1002 IP6_EXTHDR_GET(fh, struct ip6_frag *, m, 1003 eoff, sizeof(*fh)); 1004 if (fh == NULL) { 1005 ICMP6STAT_INC(icp6s_tooshort); 1006 return (-1); 1007 } 1008 #endif 1009 /* 1010 * Data after a fragment header is meaningless 1011 * unless it is the first fragment, but 1012 * we'll go to the notify label for path MTU 1013 * discovery. 1014 */ 1015 if (fh->ip6f_offlg & IP6F_OFF_MASK) 1016 goto notify; 1017 1018 eoff += sizeof(struct ip6_frag); 1019 nxt = fh->ip6f_nxt; 1020 break; 1021 default: 1022 /* 1023 * This case includes ESP and the No Next 1024 * Header. In such cases going to the notify 1025 * label does not have any meaning 1026 * (i.e. ctlfunc will be NULL), but we go 1027 * anyway since we might have to update 1028 * path MTU information. 1029 */ 1030 goto notify; 1031 } 1032 } 1033 notify: 1034 #ifndef PULLDOWN_TEST 1035 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 1036 #else 1037 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, 1038 sizeof(*icmp6) + sizeof(struct ip6_hdr)); 1039 if (icmp6 == NULL) { 1040 ICMP6STAT_INC(icp6s_tooshort); 1041 return (-1); 1042 } 1043 #endif 1044 1045 /* 1046 * retrieve parameters from the inner IPv6 header, and convert 1047 * them into sockaddr structures. 1048 * XXX: there is no guarantee that the source or destination 1049 * addresses of the inner packet are in the same scope as 1050 * the addresses of the icmp packet. But there is no other 1051 * way to determine the zone. 1052 */ 1053 eip6 = (struct ip6_hdr *)(icmp6 + 1); 1054 1055 bzero(&icmp6dst, sizeof(icmp6dst)); 1056 icmp6dst.sin6_len = sizeof(struct sockaddr_in6); 1057 icmp6dst.sin6_family = AF_INET6; 1058 if (finaldst == NULL) 1059 icmp6dst.sin6_addr = eip6->ip6_dst; 1060 else 1061 icmp6dst.sin6_addr = *finaldst; 1062 if (in6_setscope(&icmp6dst.sin6_addr, m->m_pkthdr.rcvif, NULL)) 1063 goto freeit; 1064 bzero(&icmp6src, sizeof(icmp6src)); 1065 icmp6src.sin6_len = sizeof(struct sockaddr_in6); 1066 icmp6src.sin6_family = AF_INET6; 1067 icmp6src.sin6_addr = eip6->ip6_src; 1068 if (in6_setscope(&icmp6src.sin6_addr, m->m_pkthdr.rcvif, NULL)) 1069 goto freeit; 1070 icmp6src.sin6_flowinfo = 1071 (eip6->ip6_flow & IPV6_FLOWLABEL_MASK); 1072 1073 if (finaldst == NULL) 1074 finaldst = &eip6->ip6_dst; 1075 ip6cp.ip6c_m = m; 1076 ip6cp.ip6c_icmp6 = icmp6; 1077 ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1); 1078 ip6cp.ip6c_off = eoff; 1079 ip6cp.ip6c_finaldst = finaldst; 1080 ip6cp.ip6c_src = &icmp6src; 1081 ip6cp.ip6c_nxt = nxt; 1082 1083 if (icmp6type == ICMP6_PACKET_TOO_BIG) { 1084 notifymtu = ntohl(icmp6->icmp6_mtu); 1085 ip6cp.ip6c_cmdarg = (void *)¬ifymtu; 1086 icmp6_mtudisc_update(&ip6cp, 1); /*XXX*/ 1087 } 1088 1089 ctlfunc = (void (*)(int, struct sockaddr *, void *)) 1090 (inet6sw[ip6_protox[nxt]].pr_ctlinput); 1091 if (ctlfunc) { 1092 (void) (*ctlfunc)(code, (struct sockaddr *)&icmp6dst, 1093 &ip6cp); 1094 } 1095 } 1096 *mp = m; 1097 return (0); 1098 1099 freeit: 1100 m_freem(m); 1101 return (-1); 1102 } 1103 1104 void 1105 icmp6_mtudisc_update(struct ip6ctlparam *ip6cp, int validated) 1106 { 1107 struct in6_addr *dst = ip6cp->ip6c_finaldst; 1108 struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6; 1109 struct mbuf *m = ip6cp->ip6c_m; /* will be necessary for scope issue */ 1110 u_int mtu = ntohl(icmp6->icmp6_mtu); 1111 struct in_conninfo inc; 1112 1113 #if 0 1114 /* 1115 * RFC2460 section 5, last paragraph. 1116 * even though minimum link MTU for IPv6 is IPV6_MMTU, 1117 * we may see ICMPv6 too big with mtu < IPV6_MMTU 1118 * due to packet translator in the middle. 1119 * see ip6_output() and ip6_getpmtu() "alwaysfrag" case for 1120 * special handling. 1121 */ 1122 if (mtu < IPV6_MMTU) 1123 return; 1124 #endif 1125 1126 /* 1127 * we reject ICMPv6 too big with abnormally small value. 1128 * XXX what is the good definition of "abnormally small"? 1129 */ 1130 if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8) 1131 return; 1132 1133 if (!validated) 1134 return; 1135 1136 /* 1137 * In case the suggested mtu is less than IPV6_MMTU, we 1138 * only need to remember that it was for above mentioned 1139 * "alwaysfrag" case. 1140 * Try to be as close to the spec as possible. 1141 */ 1142 if (mtu < IPV6_MMTU) 1143 mtu = IPV6_MMTU - 8; 1144 1145 bzero(&inc, sizeof(inc)); 1146 inc.inc_fibnum = M_GETFIB(m); 1147 inc.inc_flags |= INC_ISIPV6; 1148 inc.inc6_faddr = *dst; 1149 if (in6_setscope(&inc.inc6_faddr, m->m_pkthdr.rcvif, NULL)) 1150 return; 1151 1152 if (mtu < tcp_maxmtu6(&inc, NULL)) { 1153 tcp_hc_updatemtu(&inc, mtu); 1154 ICMP6STAT_INC(icp6s_pmtuchg); 1155 } 1156 } 1157 1158 /* 1159 * Process a Node Information Query packet, based on 1160 * draft-ietf-ipngwg-icmp-name-lookups-07. 1161 * 1162 * Spec incompatibilities: 1163 * - IPv6 Subject address handling 1164 * - IPv4 Subject address handling support missing 1165 * - Proxy reply (answer even if it's not for me) 1166 * - joins NI group address at in6_ifattach() time only, does not cope 1167 * with hostname changes by sethostname(3) 1168 */ 1169 static struct mbuf * 1170 ni6_input(struct mbuf *m, int off) 1171 { 1172 struct icmp6_nodeinfo *ni6, *nni6; 1173 struct mbuf *n = NULL; 1174 struct prison *pr; 1175 u_int16_t qtype; 1176 int subjlen; 1177 int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); 1178 struct ni_reply_fqdn *fqdn; 1179 int addrs; /* for NI_QTYPE_NODEADDR */ 1180 struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */ 1181 struct in6_addr in6_subj; /* subject address */ 1182 struct ip6_hdr *ip6; 1183 int oldfqdn = 0; /* if 1, return pascal string (03 draft) */ 1184 char *subj = NULL; 1185 struct in6_ifaddr *ia6 = NULL; 1186 1187 ip6 = mtod(m, struct ip6_hdr *); 1188 #ifndef PULLDOWN_TEST 1189 ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off); 1190 #else 1191 IP6_EXTHDR_GET(ni6, struct icmp6_nodeinfo *, m, off, sizeof(*ni6)); 1192 if (ni6 == NULL) { 1193 /* m is already reclaimed */ 1194 return (NULL); 1195 } 1196 #endif 1197 1198 /* 1199 * Validate IPv6 source address. 1200 * The default configuration MUST be to refuse answering queries from 1201 * global-scope addresses according to RFC4602. 1202 * Notes: 1203 * - it's not very clear what "refuse" means; this implementation 1204 * simply drops it. 1205 * - it's not very easy to identify global-scope (unicast) addresses 1206 * since there are many prefixes for them. It should be safer 1207 * and in practice sufficient to check "all" but loopback and 1208 * link-local (note that site-local unicast was deprecated and 1209 * ULA is defined as global scope-wise) 1210 */ 1211 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_GLOBALOK) == 0 && 1212 !IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) && 1213 !IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) 1214 goto bad; 1215 1216 /* 1217 * Validate IPv6 destination address. 1218 * 1219 * The Responder must discard the Query without further processing 1220 * unless it is one of the Responder's unicast or anycast addresses, or 1221 * a link-local scope multicast address which the Responder has joined. 1222 * [RFC4602, Section 5.] 1223 */ 1224 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 1225 if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst)) 1226 goto bad; 1227 /* else it's a link-local multicast, fine */ 1228 } else { /* unicast or anycast */ 1229 ia6 = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */); 1230 if (ia6 == NULL) 1231 goto bad; /* XXX impossible */ 1232 1233 if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) && 1234 !(V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK)) { 1235 ifa_free(&ia6->ia_ifa); 1236 nd6log((LOG_DEBUG, "ni6_input: ignore node info to " 1237 "a temporary address in %s:%d", 1238 __FILE__, __LINE__)); 1239 goto bad; 1240 } 1241 ifa_free(&ia6->ia_ifa); 1242 } 1243 1244 /* validate query Subject field. */ 1245 qtype = ntohs(ni6->ni_qtype); 1246 subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo); 1247 switch (qtype) { 1248 case NI_QTYPE_NOOP: 1249 case NI_QTYPE_SUPTYPES: 1250 /* 07 draft */ 1251 if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0) 1252 break; 1253 /* FALLTHROUGH */ 1254 case NI_QTYPE_FQDN: 1255 case NI_QTYPE_NODEADDR: 1256 case NI_QTYPE_IPV4ADDR: 1257 switch (ni6->ni_code) { 1258 case ICMP6_NI_SUBJ_IPV6: 1259 #if ICMP6_NI_SUBJ_IPV6 != 0 1260 case 0: 1261 #endif 1262 /* 1263 * backward compatibility - try to accept 03 draft 1264 * format, where no Subject is present. 1265 */ 1266 if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 && 1267 subjlen == 0) { 1268 oldfqdn++; 1269 break; 1270 } 1271 #if ICMP6_NI_SUBJ_IPV6 != 0 1272 if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6) 1273 goto bad; 1274 #endif 1275 1276 if (subjlen != sizeof(struct in6_addr)) 1277 goto bad; 1278 1279 /* 1280 * Validate Subject address. 1281 * 1282 * Not sure what exactly "address belongs to the node" 1283 * means in the spec, is it just unicast, or what? 1284 * 1285 * At this moment we consider Subject address as 1286 * "belong to the node" if the Subject address equals 1287 * to the IPv6 destination address; validation for 1288 * IPv6 destination address should have done enough 1289 * check for us. 1290 * 1291 * We do not do proxy at this moment. 1292 */ 1293 /* m_pulldown instead of copy? */ 1294 m_copydata(m, off + sizeof(struct icmp6_nodeinfo), 1295 subjlen, (caddr_t)&in6_subj); 1296 if (in6_setscope(&in6_subj, m->m_pkthdr.rcvif, NULL)) 1297 goto bad; 1298 1299 subj = (char *)&in6_subj; 1300 if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &in6_subj)) 1301 break; 1302 1303 /* 1304 * XXX if we are to allow other cases, we should really 1305 * be careful about scope here. 1306 * basically, we should disallow queries toward IPv6 1307 * destination X with subject Y, 1308 * if scope(X) > scope(Y). 1309 * if we allow scope(X) > scope(Y), it will result in 1310 * information leakage across scope boundary. 1311 */ 1312 goto bad; 1313 1314 case ICMP6_NI_SUBJ_FQDN: 1315 /* 1316 * Validate Subject name with gethostname(3). 1317 * 1318 * The behavior may need some debate, since: 1319 * - we are not sure if the node has FQDN as 1320 * hostname (returned by gethostname(3)). 1321 * - the code does wildcard match for truncated names. 1322 * however, we are not sure if we want to perform 1323 * wildcard match, if gethostname(3) side has 1324 * truncated hostname. 1325 */ 1326 pr = curthread->td_ucred->cr_prison; 1327 mtx_lock(&pr->pr_mtx); 1328 n = ni6_nametodns(pr->pr_hostname, 1329 strlen(pr->pr_hostname), 0); 1330 mtx_unlock(&pr->pr_mtx); 1331 if (!n || n->m_next || n->m_len == 0) 1332 goto bad; 1333 IP6_EXTHDR_GET(subj, char *, m, 1334 off + sizeof(struct icmp6_nodeinfo), subjlen); 1335 if (subj == NULL) 1336 goto bad; 1337 if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *), 1338 n->m_len)) { 1339 goto bad; 1340 } 1341 m_freem(n); 1342 n = NULL; 1343 break; 1344 1345 case ICMP6_NI_SUBJ_IPV4: /* XXX: to be implemented? */ 1346 default: 1347 goto bad; 1348 } 1349 break; 1350 } 1351 1352 /* refuse based on configuration. XXX ICMP6_NI_REFUSED? */ 1353 switch (qtype) { 1354 case NI_QTYPE_FQDN: 1355 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_FQDNOK) == 0) 1356 goto bad; 1357 break; 1358 case NI_QTYPE_NODEADDR: 1359 case NI_QTYPE_IPV4ADDR: 1360 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_NODEADDROK) == 0) 1361 goto bad; 1362 break; 1363 } 1364 1365 /* guess reply length */ 1366 switch (qtype) { 1367 case NI_QTYPE_NOOP: 1368 break; /* no reply data */ 1369 case NI_QTYPE_SUPTYPES: 1370 replylen += sizeof(u_int32_t); 1371 break; 1372 case NI_QTYPE_FQDN: 1373 /* XXX will append an mbuf */ 1374 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); 1375 break; 1376 case NI_QTYPE_NODEADDR: 1377 addrs = ni6_addrs(ni6, m, &ifp, (struct in6_addr *)subj); 1378 if ((replylen += addrs * (sizeof(struct in6_addr) + 1379 sizeof(u_int32_t))) > MCLBYTES) 1380 replylen = MCLBYTES; /* XXX: will truncate pkt later */ 1381 break; 1382 case NI_QTYPE_IPV4ADDR: 1383 /* unsupported - should respond with unknown Qtype? */ 1384 break; 1385 default: 1386 /* 1387 * XXX: We must return a reply with the ICMP6 code 1388 * `unknown Qtype' in this case. However we regard the case 1389 * as an FQDN query for backward compatibility. 1390 * Older versions set a random value to this field, 1391 * so it rarely varies in the defined qtypes. 1392 * But the mechanism is not reliable... 1393 * maybe we should obsolete older versions. 1394 */ 1395 qtype = NI_QTYPE_FQDN; 1396 /* XXX will append an mbuf */ 1397 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); 1398 oldfqdn++; 1399 break; 1400 } 1401 1402 /* Allocate an mbuf to reply. */ 1403 if (replylen > MCLBYTES) { 1404 /* 1405 * XXX: should we try to allocate more? But MCLBYTES 1406 * is probably much larger than IPV6_MMTU... 1407 */ 1408 goto bad; 1409 } 1410 if (replylen > MHLEN) 1411 n = m_getcl(M_NOWAIT, m->m_type, M_PKTHDR); 1412 else 1413 n = m_gethdr(M_NOWAIT, m->m_type); 1414 if (n == NULL) { 1415 m_freem(m); 1416 return (NULL); 1417 } 1418 m_move_pkthdr(n, m); /* just for recvif and FIB */ 1419 n->m_pkthdr.len = n->m_len = replylen; 1420 1421 /* copy mbuf header and IPv6 + Node Information base headers */ 1422 bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr)); 1423 nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1); 1424 bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo)); 1425 1426 /* qtype dependent procedure */ 1427 switch (qtype) { 1428 case NI_QTYPE_NOOP: 1429 nni6->ni_code = ICMP6_NI_SUCCESS; 1430 nni6->ni_flags = 0; 1431 break; 1432 case NI_QTYPE_SUPTYPES: 1433 { 1434 u_int32_t v; 1435 nni6->ni_code = ICMP6_NI_SUCCESS; 1436 nni6->ni_flags = htons(0x0000); /* raw bitmap */ 1437 /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */ 1438 v = (u_int32_t)htonl(0x0000000f); 1439 bcopy(&v, nni6 + 1, sizeof(u_int32_t)); 1440 break; 1441 } 1442 case NI_QTYPE_FQDN: 1443 nni6->ni_code = ICMP6_NI_SUCCESS; 1444 fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) + 1445 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo)); 1446 nni6->ni_flags = 0; /* XXX: meaningless TTL */ 1447 fqdn->ni_fqdn_ttl = 0; /* ditto. */ 1448 /* 1449 * XXX do we really have FQDN in hostname? 1450 */ 1451 pr = curthread->td_ucred->cr_prison; 1452 mtx_lock(&pr->pr_mtx); 1453 n->m_next = ni6_nametodns(pr->pr_hostname, 1454 strlen(pr->pr_hostname), oldfqdn); 1455 mtx_unlock(&pr->pr_mtx); 1456 if (n->m_next == NULL) 1457 goto bad; 1458 /* XXX we assume that n->m_next is not a chain */ 1459 if (n->m_next->m_next != NULL) 1460 goto bad; 1461 n->m_pkthdr.len += n->m_next->m_len; 1462 break; 1463 case NI_QTYPE_NODEADDR: 1464 { 1465 int lenlim, copied; 1466 1467 nni6->ni_code = ICMP6_NI_SUCCESS; 1468 n->m_pkthdr.len = n->m_len = 1469 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); 1470 lenlim = M_TRAILINGSPACE(n); 1471 copied = ni6_store_addrs(ni6, nni6, ifp, lenlim); 1472 /* XXX: reset mbuf length */ 1473 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + 1474 sizeof(struct icmp6_nodeinfo) + copied; 1475 break; 1476 } 1477 default: 1478 break; /* XXX impossible! */ 1479 } 1480 1481 nni6->ni_type = ICMP6_NI_REPLY; 1482 m_freem(m); 1483 return (n); 1484 1485 bad: 1486 m_freem(m); 1487 if (n) 1488 m_freem(n); 1489 return (NULL); 1490 } 1491 1492 /* 1493 * make a mbuf with DNS-encoded string. no compression support. 1494 * 1495 * XXX names with less than 2 dots (like "foo" or "foo.section") will be 1496 * treated as truncated name (two \0 at the end). this is a wild guess. 1497 * 1498 * old - return pascal string if non-zero 1499 */ 1500 static struct mbuf * 1501 ni6_nametodns(const char *name, int namelen, int old) 1502 { 1503 struct mbuf *m; 1504 char *cp, *ep; 1505 const char *p, *q; 1506 int i, len, nterm; 1507 1508 if (old) 1509 len = namelen + 1; 1510 else 1511 len = MCLBYTES; 1512 1513 /* Because MAXHOSTNAMELEN is usually 256, we use cluster mbuf. */ 1514 if (len > MLEN) 1515 m = m_getcl(M_NOWAIT, MT_DATA, 0); 1516 else 1517 m = m_get(M_NOWAIT, MT_DATA); 1518 if (m == NULL) 1519 goto fail; 1520 1521 if (old) { 1522 m->m_len = len; 1523 *mtod(m, char *) = namelen; 1524 bcopy(name, mtod(m, char *) + 1, namelen); 1525 return m; 1526 } else { 1527 m->m_len = 0; 1528 cp = mtod(m, char *); 1529 ep = mtod(m, char *) + M_TRAILINGSPACE(m); 1530 1531 /* if not certain about my name, return empty buffer */ 1532 if (namelen == 0) 1533 return m; 1534 1535 /* 1536 * guess if it looks like shortened hostname, or FQDN. 1537 * shortened hostname needs two trailing "\0". 1538 */ 1539 i = 0; 1540 for (p = name; p < name + namelen; p++) { 1541 if (*p && *p == '.') 1542 i++; 1543 } 1544 if (i < 2) 1545 nterm = 2; 1546 else 1547 nterm = 1; 1548 1549 p = name; 1550 while (cp < ep && p < name + namelen) { 1551 i = 0; 1552 for (q = p; q < name + namelen && *q && *q != '.'; q++) 1553 i++; 1554 /* result does not fit into mbuf */ 1555 if (cp + i + 1 >= ep) 1556 goto fail; 1557 /* 1558 * DNS label length restriction, RFC1035 page 8. 1559 * "i == 0" case is included here to avoid returning 1560 * 0-length label on "foo..bar". 1561 */ 1562 if (i <= 0 || i >= 64) 1563 goto fail; 1564 *cp++ = i; 1565 bcopy(p, cp, i); 1566 cp += i; 1567 p = q; 1568 if (p < name + namelen && *p == '.') 1569 p++; 1570 } 1571 /* termination */ 1572 if (cp + nterm >= ep) 1573 goto fail; 1574 while (nterm-- > 0) 1575 *cp++ = '\0'; 1576 m->m_len = cp - mtod(m, char *); 1577 return m; 1578 } 1579 1580 panic("should not reach here"); 1581 /* NOTREACHED */ 1582 1583 fail: 1584 if (m) 1585 m_freem(m); 1586 return NULL; 1587 } 1588 1589 /* 1590 * check if two DNS-encoded string matches. takes care of truncated 1591 * form (with \0\0 at the end). no compression support. 1592 * XXX upper/lowercase match (see RFC2065) 1593 */ 1594 static int 1595 ni6_dnsmatch(const char *a, int alen, const char *b, int blen) 1596 { 1597 const char *a0, *b0; 1598 int l; 1599 1600 /* simplest case - need validation? */ 1601 if (alen == blen && bcmp(a, b, alen) == 0) 1602 return 1; 1603 1604 a0 = a; 1605 b0 = b; 1606 1607 /* termination is mandatory */ 1608 if (alen < 2 || blen < 2) 1609 return 0; 1610 if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0') 1611 return 0; 1612 alen--; 1613 blen--; 1614 1615 while (a - a0 < alen && b - b0 < blen) { 1616 if (a - a0 + 1 > alen || b - b0 + 1 > blen) 1617 return 0; 1618 1619 if ((signed char)a[0] < 0 || (signed char)b[0] < 0) 1620 return 0; 1621 /* we don't support compression yet */ 1622 if (a[0] >= 64 || b[0] >= 64) 1623 return 0; 1624 1625 /* truncated case */ 1626 if (a[0] == 0 && a - a0 == alen - 1) 1627 return 1; 1628 if (b[0] == 0 && b - b0 == blen - 1) 1629 return 1; 1630 if (a[0] == 0 || b[0] == 0) 1631 return 0; 1632 1633 if (a[0] != b[0]) 1634 return 0; 1635 l = a[0]; 1636 if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen) 1637 return 0; 1638 if (bcmp(a + 1, b + 1, l) != 0) 1639 return 0; 1640 1641 a += 1 + l; 1642 b += 1 + l; 1643 } 1644 1645 if (a - a0 == alen && b - b0 == blen) 1646 return 1; 1647 else 1648 return 0; 1649 } 1650 1651 /* 1652 * calculate the number of addresses to be returned in the node info reply. 1653 */ 1654 static int 1655 ni6_addrs(struct icmp6_nodeinfo *ni6, struct mbuf *m, struct ifnet **ifpp, 1656 struct in6_addr *subj) 1657 { 1658 struct ifnet *ifp; 1659 struct in6_ifaddr *ifa6; 1660 struct ifaddr *ifa; 1661 int addrs = 0, addrsofif, iffound = 0; 1662 int niflags = ni6->ni_flags; 1663 1664 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) { 1665 switch (ni6->ni_code) { 1666 case ICMP6_NI_SUBJ_IPV6: 1667 if (subj == NULL) /* must be impossible... */ 1668 return (0); 1669 break; 1670 default: 1671 /* 1672 * XXX: we only support IPv6 subject address for 1673 * this Qtype. 1674 */ 1675 return (0); 1676 } 1677 } 1678 1679 IFNET_RLOCK_NOSLEEP(); 1680 CK_STAILQ_FOREACH(ifp, &V_ifnet, if_link) { 1681 addrsofif = 0; 1682 IF_ADDR_RLOCK(ifp); 1683 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 1684 if (ifa->ifa_addr->sa_family != AF_INET6) 1685 continue; 1686 ifa6 = (struct in6_ifaddr *)ifa; 1687 1688 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 && 1689 IN6_ARE_ADDR_EQUAL(subj, &ifa6->ia_addr.sin6_addr)) 1690 iffound = 1; 1691 1692 /* 1693 * IPv4-mapped addresses can only be returned by a 1694 * Node Information proxy, since they represent 1695 * addresses of IPv4-only nodes, which perforce do 1696 * not implement this protocol. 1697 * [icmp-name-lookups-07, Section 5.4] 1698 * So we don't support NI_NODEADDR_FLAG_COMPAT in 1699 * this function at this moment. 1700 */ 1701 1702 /* What do we have to do about ::1? */ 1703 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { 1704 case IPV6_ADDR_SCOPE_LINKLOCAL: 1705 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) 1706 continue; 1707 break; 1708 case IPV6_ADDR_SCOPE_SITELOCAL: 1709 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) 1710 continue; 1711 break; 1712 case IPV6_ADDR_SCOPE_GLOBAL: 1713 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) 1714 continue; 1715 break; 1716 default: 1717 continue; 1718 } 1719 1720 /* 1721 * check if anycast is okay. 1722 * XXX: just experimental. not in the spec. 1723 */ 1724 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && 1725 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) 1726 continue; /* we need only unicast addresses */ 1727 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && 1728 (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) { 1729 continue; 1730 } 1731 addrsofif++; /* count the address */ 1732 } 1733 IF_ADDR_RUNLOCK(ifp); 1734 if (iffound) { 1735 *ifpp = ifp; 1736 IFNET_RUNLOCK_NOSLEEP(); 1737 return (addrsofif); 1738 } 1739 1740 addrs += addrsofif; 1741 } 1742 IFNET_RUNLOCK_NOSLEEP(); 1743 1744 return (addrs); 1745 } 1746 1747 static int 1748 ni6_store_addrs(struct icmp6_nodeinfo *ni6, struct icmp6_nodeinfo *nni6, 1749 struct ifnet *ifp0, int resid) 1750 { 1751 struct ifnet *ifp; 1752 struct in6_ifaddr *ifa6; 1753 struct ifaddr *ifa; 1754 struct ifnet *ifp_dep = NULL; 1755 int copied = 0, allow_deprecated = 0; 1756 u_char *cp = (u_char *)(nni6 + 1); 1757 int niflags = ni6->ni_flags; 1758 u_int32_t ltime; 1759 1760 if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL)) 1761 return (0); /* needless to copy */ 1762 1763 IFNET_RLOCK_NOSLEEP(); 1764 ifp = ifp0 ? ifp0 : CK_STAILQ_FIRST(&V_ifnet); 1765 again: 1766 1767 for (; ifp; ifp = CK_STAILQ_NEXT(ifp, if_link)) { 1768 IF_ADDR_RLOCK(ifp); 1769 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 1770 if (ifa->ifa_addr->sa_family != AF_INET6) 1771 continue; 1772 ifa6 = (struct in6_ifaddr *)ifa; 1773 1774 if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 && 1775 allow_deprecated == 0) { 1776 /* 1777 * prefererred address should be put before 1778 * deprecated addresses. 1779 */ 1780 1781 /* record the interface for later search */ 1782 if (ifp_dep == NULL) 1783 ifp_dep = ifp; 1784 1785 continue; 1786 } else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 && 1787 allow_deprecated != 0) 1788 continue; /* we now collect deprecated addrs */ 1789 1790 /* What do we have to do about ::1? */ 1791 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { 1792 case IPV6_ADDR_SCOPE_LINKLOCAL: 1793 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) 1794 continue; 1795 break; 1796 case IPV6_ADDR_SCOPE_SITELOCAL: 1797 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) 1798 continue; 1799 break; 1800 case IPV6_ADDR_SCOPE_GLOBAL: 1801 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) 1802 continue; 1803 break; 1804 default: 1805 continue; 1806 } 1807 1808 /* 1809 * check if anycast is okay. 1810 * XXX: just experimental. not in the spec. 1811 */ 1812 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && 1813 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) 1814 continue; 1815 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && 1816 (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) { 1817 continue; 1818 } 1819 1820 /* now we can copy the address */ 1821 if (resid < sizeof(struct in6_addr) + 1822 sizeof(u_int32_t)) { 1823 IF_ADDR_RUNLOCK(ifp); 1824 /* 1825 * We give up much more copy. 1826 * Set the truncate flag and return. 1827 */ 1828 nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE; 1829 IFNET_RUNLOCK_NOSLEEP(); 1830 return (copied); 1831 } 1832 1833 /* 1834 * Set the TTL of the address. 1835 * The TTL value should be one of the following 1836 * according to the specification: 1837 * 1838 * 1. The remaining lifetime of a DHCP lease on the 1839 * address, or 1840 * 2. The remaining Valid Lifetime of a prefix from 1841 * which the address was derived through Stateless 1842 * Autoconfiguration. 1843 * 1844 * Note that we currently do not support stateful 1845 * address configuration by DHCPv6, so the former 1846 * case can't happen. 1847 */ 1848 if (ifa6->ia6_lifetime.ia6t_expire == 0) 1849 ltime = ND6_INFINITE_LIFETIME; 1850 else { 1851 if (ifa6->ia6_lifetime.ia6t_expire > 1852 time_uptime) 1853 ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_uptime); 1854 else 1855 ltime = 0; 1856 } 1857 1858 bcopy(<ime, cp, sizeof(u_int32_t)); 1859 cp += sizeof(u_int32_t); 1860 1861 /* copy the address itself */ 1862 bcopy(&ifa6->ia_addr.sin6_addr, cp, 1863 sizeof(struct in6_addr)); 1864 in6_clearscope((struct in6_addr *)cp); /* XXX */ 1865 cp += sizeof(struct in6_addr); 1866 1867 resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t)); 1868 copied += (sizeof(struct in6_addr) + sizeof(u_int32_t)); 1869 } 1870 IF_ADDR_RUNLOCK(ifp); 1871 if (ifp0) /* we need search only on the specified IF */ 1872 break; 1873 } 1874 1875 if (allow_deprecated == 0 && ifp_dep != NULL) { 1876 ifp = ifp_dep; 1877 allow_deprecated = 1; 1878 1879 goto again; 1880 } 1881 1882 IFNET_RUNLOCK_NOSLEEP(); 1883 1884 return (copied); 1885 } 1886 1887 /* 1888 * XXX almost dup'ed code with rip6_input. 1889 */ 1890 static int 1891 icmp6_rip6_input(struct mbuf **mp, int off) 1892 { 1893 struct mbuf *m = *mp; 1894 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1895 struct inpcb *in6p; 1896 struct inpcb *last = NULL; 1897 struct sockaddr_in6 fromsa; 1898 struct icmp6_hdr *icmp6; 1899 struct epoch_tracker et; 1900 struct mbuf *opts = NULL; 1901 1902 #ifndef PULLDOWN_TEST 1903 /* this is assumed to be safe. */ 1904 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off); 1905 #else 1906 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6)); 1907 if (icmp6 == NULL) { 1908 /* m is already reclaimed */ 1909 return (IPPROTO_DONE); 1910 } 1911 #endif 1912 1913 /* 1914 * XXX: the address may have embedded scope zone ID, which should be 1915 * hidden from applications. 1916 */ 1917 bzero(&fromsa, sizeof(fromsa)); 1918 fromsa.sin6_family = AF_INET6; 1919 fromsa.sin6_len = sizeof(struct sockaddr_in6); 1920 fromsa.sin6_addr = ip6->ip6_src; 1921 if (sa6_recoverscope(&fromsa)) { 1922 m_freem(m); 1923 return (IPPROTO_DONE); 1924 } 1925 1926 INP_INFO_RLOCK_ET(&V_ripcbinfo, et); 1927 CK_LIST_FOREACH(in6p, &V_ripcb, inp_list) { 1928 if ((in6p->inp_vflag & INP_IPV6) == 0) 1929 continue; 1930 if (in6p->inp_ip_p != IPPROTO_ICMPV6) 1931 continue; 1932 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) && 1933 !IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &ip6->ip6_dst)) 1934 continue; 1935 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr) && 1936 !IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src)) 1937 continue; 1938 INP_RLOCK(in6p); 1939 if (__predict_false(in6p->inp_flags2 & INP_FREED)) { 1940 INP_RUNLOCK(in6p); 1941 continue; 1942 } 1943 if (ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type, 1944 in6p->in6p_icmp6filt)) { 1945 INP_RUNLOCK(in6p); 1946 continue; 1947 } 1948 if (last != NULL) { 1949 struct mbuf *n = NULL; 1950 1951 /* 1952 * Recent network drivers tend to allocate a single 1953 * mbuf cluster, rather than to make a couple of 1954 * mbufs without clusters. Also, since the IPv6 code 1955 * path tries to avoid m_pullup(), it is highly 1956 * probable that we still have an mbuf cluster here 1957 * even though the necessary length can be stored in an 1958 * mbuf's internal buffer. 1959 * Meanwhile, the default size of the receive socket 1960 * buffer for raw sockets is not so large. This means 1961 * the possibility of packet loss is relatively higher 1962 * than before. To avoid this scenario, we copy the 1963 * received data to a separate mbuf that does not use 1964 * a cluster, if possible. 1965 * XXX: it is better to copy the data after stripping 1966 * intermediate headers. 1967 */ 1968 if ((m->m_flags & M_EXT) && m->m_next == NULL && 1969 m->m_len <= MHLEN) { 1970 n = m_get(M_NOWAIT, m->m_type); 1971 if (n != NULL) { 1972 if (m_dup_pkthdr(n, m, M_NOWAIT)) { 1973 bcopy(m->m_data, n->m_data, 1974 m->m_len); 1975 n->m_len = m->m_len; 1976 } else { 1977 m_free(n); 1978 n = NULL; 1979 } 1980 } 1981 } 1982 if (n != NULL || 1983 (n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) != NULL) { 1984 if (last->inp_flags & INP_CONTROLOPTS) 1985 ip6_savecontrol(last, n, &opts); 1986 /* strip intermediate headers */ 1987 m_adj(n, off); 1988 SOCKBUF_LOCK(&last->inp_socket->so_rcv); 1989 if (sbappendaddr_locked( 1990 &last->inp_socket->so_rcv, 1991 (struct sockaddr *)&fromsa, n, opts) 1992 == 0) { 1993 /* should notify about lost packet */ 1994 m_freem(n); 1995 if (opts) { 1996 m_freem(opts); 1997 } 1998 SOCKBUF_UNLOCK( 1999 &last->inp_socket->so_rcv); 2000 } else 2001 sorwakeup_locked(last->inp_socket); 2002 opts = NULL; 2003 } 2004 INP_RUNLOCK(last); 2005 } 2006 last = in6p; 2007 } 2008 INP_INFO_RUNLOCK_ET(&V_ripcbinfo, et); 2009 if (last != NULL) { 2010 if (last->inp_flags & INP_CONTROLOPTS) 2011 ip6_savecontrol(last, m, &opts); 2012 /* strip intermediate headers */ 2013 m_adj(m, off); 2014 2015 /* avoid using mbuf clusters if possible (see above) */ 2016 if ((m->m_flags & M_EXT) && m->m_next == NULL && 2017 m->m_len <= MHLEN) { 2018 struct mbuf *n; 2019 2020 n = m_get(M_NOWAIT, m->m_type); 2021 if (n != NULL) { 2022 if (m_dup_pkthdr(n, m, M_NOWAIT)) { 2023 bcopy(m->m_data, n->m_data, m->m_len); 2024 n->m_len = m->m_len; 2025 2026 m_freem(m); 2027 m = n; 2028 } else { 2029 m_freem(n); 2030 n = NULL; 2031 } 2032 } 2033 } 2034 SOCKBUF_LOCK(&last->inp_socket->so_rcv); 2035 if (sbappendaddr_locked(&last->inp_socket->so_rcv, 2036 (struct sockaddr *)&fromsa, m, opts) == 0) { 2037 m_freem(m); 2038 if (opts) 2039 m_freem(opts); 2040 SOCKBUF_UNLOCK(&last->inp_socket->so_rcv); 2041 } else 2042 sorwakeup_locked(last->inp_socket); 2043 INP_RUNLOCK(last); 2044 } else { 2045 m_freem(m); 2046 IP6STAT_DEC(ip6s_delivered); 2047 } 2048 return IPPROTO_DONE; 2049 } 2050 2051 /* 2052 * Reflect the ip6 packet back to the source. 2053 * OFF points to the icmp6 header, counted from the top of the mbuf. 2054 */ 2055 void 2056 icmp6_reflect(struct mbuf *m, size_t off) 2057 { 2058 struct in6_addr src6, *srcp; 2059 struct ip6_hdr *ip6; 2060 struct icmp6_hdr *icmp6; 2061 struct in6_ifaddr *ia = NULL; 2062 struct ifnet *outif = NULL; 2063 int plen; 2064 int type, code, hlim; 2065 2066 /* too short to reflect */ 2067 if (off < sizeof(struct ip6_hdr)) { 2068 nd6log((LOG_DEBUG, 2069 "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n", 2070 (u_long)off, (u_long)sizeof(struct ip6_hdr), 2071 __FILE__, __LINE__)); 2072 goto bad; 2073 } 2074 2075 /* 2076 * If there are extra headers between IPv6 and ICMPv6, strip 2077 * off that header first. 2078 */ 2079 #ifdef DIAGNOSTIC 2080 if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN) 2081 panic("assumption failed in icmp6_reflect"); 2082 #endif 2083 if (off > sizeof(struct ip6_hdr)) { 2084 size_t l; 2085 struct ip6_hdr nip6; 2086 2087 l = off - sizeof(struct ip6_hdr); 2088 m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6); 2089 m_adj(m, l); 2090 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 2091 if (m->m_len < l) { 2092 if ((m = m_pullup(m, l)) == NULL) 2093 return; 2094 } 2095 bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6)); 2096 } else /* off == sizeof(struct ip6_hdr) */ { 2097 size_t l; 2098 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 2099 if (m->m_len < l) { 2100 if ((m = m_pullup(m, l)) == NULL) 2101 return; 2102 } 2103 } 2104 plen = m->m_pkthdr.len - sizeof(struct ip6_hdr); 2105 ip6 = mtod(m, struct ip6_hdr *); 2106 ip6->ip6_nxt = IPPROTO_ICMPV6; 2107 icmp6 = (struct icmp6_hdr *)(ip6 + 1); 2108 type = icmp6->icmp6_type; /* keep type for statistics */ 2109 code = icmp6->icmp6_code; /* ditto. */ 2110 hlim = 0; 2111 srcp = NULL; 2112 2113 /* 2114 * If the incoming packet was addressed directly to us (i.e. unicast), 2115 * use dst as the src for the reply. 2116 * The IN6_IFF_NOTREADY case should be VERY rare, but is possible 2117 * (for example) when we encounter an error while forwarding procedure 2118 * destined to a duplicated address of ours. 2119 */ 2120 if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 2121 ia = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */); 2122 if (ia != NULL && !(ia->ia6_flags & 2123 (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) { 2124 src6 = ia->ia_addr.sin6_addr; 2125 srcp = &src6; 2126 2127 if (m->m_pkthdr.rcvif != NULL) { 2128 /* XXX: This may not be the outgoing interface */ 2129 hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim; 2130 } else 2131 hlim = V_ip6_defhlim; 2132 } 2133 if (ia != NULL) 2134 ifa_free(&ia->ia_ifa); 2135 } 2136 2137 if (srcp == NULL) { 2138 int error; 2139 struct in6_addr dst6; 2140 uint32_t scopeid; 2141 2142 /* 2143 * This case matches to multicasts, our anycast, or unicasts 2144 * that we do not own. Select a source address based on the 2145 * source address of the erroneous packet. 2146 */ 2147 in6_splitscope(&ip6->ip6_src, &dst6, &scopeid); 2148 error = in6_selectsrc_addr(M_GETFIB(m), &dst6, 2149 scopeid, NULL, &src6, &hlim); 2150 2151 if (error) { 2152 char ip6buf[INET6_ADDRSTRLEN]; 2153 nd6log((LOG_DEBUG, 2154 "icmp6_reflect: source can't be determined: " 2155 "dst=%s, error=%d\n", 2156 ip6_sprintf(ip6buf, &ip6->ip6_dst), error)); 2157 goto bad; 2158 } 2159 srcp = &src6; 2160 } 2161 /* 2162 * ip6_input() drops a packet if its src is multicast. 2163 * So, the src is never multicast. 2164 */ 2165 ip6->ip6_dst = ip6->ip6_src; 2166 ip6->ip6_src = *srcp; 2167 ip6->ip6_flow = 0; 2168 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2169 ip6->ip6_vfc |= IPV6_VERSION; 2170 ip6->ip6_nxt = IPPROTO_ICMPV6; 2171 ip6->ip6_hlim = hlim; 2172 2173 icmp6->icmp6_cksum = 0; 2174 icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2175 sizeof(struct ip6_hdr), plen); 2176 2177 /* 2178 * XXX option handling 2179 */ 2180 2181 m->m_flags &= ~(M_BCAST|M_MCAST); 2182 m->m_pkthdr.rcvif = NULL; 2183 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2184 if (outif) 2185 icmp6_ifoutstat_inc(outif, type, code); 2186 2187 return; 2188 2189 bad: 2190 m_freem(m); 2191 return; 2192 } 2193 2194 void 2195 icmp6_fasttimo(void) 2196 { 2197 2198 mld_fasttimo(); 2199 } 2200 2201 void 2202 icmp6_slowtimo(void) 2203 { 2204 2205 mld_slowtimo(); 2206 } 2207 2208 static const char * 2209 icmp6_redirect_diag(struct in6_addr *src6, struct in6_addr *dst6, 2210 struct in6_addr *tgt6) 2211 { 2212 static char buf[1024]; 2213 char ip6bufs[INET6_ADDRSTRLEN]; 2214 char ip6bufd[INET6_ADDRSTRLEN]; 2215 char ip6buft[INET6_ADDRSTRLEN]; 2216 snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)", 2217 ip6_sprintf(ip6bufs, src6), ip6_sprintf(ip6bufd, dst6), 2218 ip6_sprintf(ip6buft, tgt6)); 2219 return buf; 2220 } 2221 2222 void 2223 icmp6_redirect_input(struct mbuf *m, int off) 2224 { 2225 struct ifnet *ifp; 2226 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 2227 struct nd_redirect *nd_rd; 2228 int icmp6len = ntohs(ip6->ip6_plen); 2229 char *lladdr = NULL; 2230 int lladdrlen = 0; 2231 int is_router; 2232 int is_onlink; 2233 struct in6_addr src6 = ip6->ip6_src; 2234 struct in6_addr redtgt6; 2235 struct in6_addr reddst6; 2236 union nd_opts ndopts; 2237 char ip6buf[INET6_ADDRSTRLEN]; 2238 2239 M_ASSERTPKTHDR(m); 2240 KASSERT(m->m_pkthdr.rcvif != NULL, ("%s: no rcvif", __func__)); 2241 2242 ifp = m->m_pkthdr.rcvif; 2243 2244 /* XXX if we are router, we don't update route by icmp6 redirect */ 2245 if (V_ip6_forwarding) 2246 goto freeit; 2247 if (!V_icmp6_rediraccept) 2248 goto freeit; 2249 2250 /* RFC 6980: Nodes MUST silently ignore fragments */ 2251 if(m->m_flags & M_FRAGMENTED) 2252 goto freeit; 2253 2254 #ifndef PULLDOWN_TEST 2255 IP6_EXTHDR_CHECK(m, off, icmp6len,); 2256 nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off); 2257 #else 2258 IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len); 2259 if (nd_rd == NULL) { 2260 ICMP6STAT_INC(icp6s_tooshort); 2261 return; 2262 } 2263 #endif 2264 redtgt6 = nd_rd->nd_rd_target; 2265 reddst6 = nd_rd->nd_rd_dst; 2266 2267 if (in6_setscope(&redtgt6, m->m_pkthdr.rcvif, NULL) || 2268 in6_setscope(&reddst6, m->m_pkthdr.rcvif, NULL)) { 2269 goto freeit; 2270 } 2271 2272 /* validation */ 2273 if (!IN6_IS_ADDR_LINKLOCAL(&src6)) { 2274 nd6log((LOG_ERR, 2275 "ICMP6 redirect sent from %s rejected; " 2276 "must be from linklocal\n", 2277 ip6_sprintf(ip6buf, &src6))); 2278 goto bad; 2279 } 2280 if (ip6->ip6_hlim != 255) { 2281 nd6log((LOG_ERR, 2282 "ICMP6 redirect sent from %s rejected; " 2283 "hlim=%d (must be 255)\n", 2284 ip6_sprintf(ip6buf, &src6), ip6->ip6_hlim)); 2285 goto bad; 2286 } 2287 { 2288 /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */ 2289 struct nhop6_basic nh6; 2290 struct in6_addr kdst; 2291 uint32_t scopeid; 2292 2293 in6_splitscope(&reddst6, &kdst, &scopeid); 2294 if (fib6_lookup_nh_basic(ifp->if_fib, &kdst, scopeid, 0, 0,&nh6)==0){ 2295 if ((nh6.nh_flags & NHF_GATEWAY) == 0) { 2296 nd6log((LOG_ERR, 2297 "ICMP6 redirect rejected; no route " 2298 "with inet6 gateway found for redirect dst: %s\n", 2299 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2300 goto bad; 2301 } 2302 2303 /* 2304 * Embed scope zone id into next hop address, since 2305 * fib6_lookup_nh_basic() returns address without embedded 2306 * scope zone id. 2307 */ 2308 if (in6_setscope(&nh6.nh_addr, m->m_pkthdr.rcvif, NULL)) 2309 goto freeit; 2310 2311 if (IN6_ARE_ADDR_EQUAL(&src6, &nh6.nh_addr) == 0) { 2312 nd6log((LOG_ERR, 2313 "ICMP6 redirect rejected; " 2314 "not equal to gw-for-src=%s (must be same): " 2315 "%s\n", 2316 ip6_sprintf(ip6buf, &nh6.nh_addr), 2317 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2318 goto bad; 2319 } 2320 } else { 2321 nd6log((LOG_ERR, 2322 "ICMP6 redirect rejected; " 2323 "no route found for redirect dst: %s\n", 2324 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2325 goto bad; 2326 } 2327 } 2328 if (IN6_IS_ADDR_MULTICAST(&reddst6)) { 2329 nd6log((LOG_ERR, 2330 "ICMP6 redirect rejected; " 2331 "redirect dst must be unicast: %s\n", 2332 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2333 goto bad; 2334 } 2335 2336 is_router = is_onlink = 0; 2337 if (IN6_IS_ADDR_LINKLOCAL(&redtgt6)) 2338 is_router = 1; /* router case */ 2339 if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0) 2340 is_onlink = 1; /* on-link destination case */ 2341 if (!is_router && !is_onlink) { 2342 nd6log((LOG_ERR, 2343 "ICMP6 redirect rejected; " 2344 "neither router case nor onlink case: %s\n", 2345 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2346 goto bad; 2347 } 2348 2349 icmp6len -= sizeof(*nd_rd); 2350 nd6_option_init(nd_rd + 1, icmp6len, &ndopts); 2351 if (nd6_options(&ndopts) < 0) { 2352 nd6log((LOG_INFO, "%s: invalid ND option, rejected: %s\n", 2353 __func__, icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2354 /* nd6_options have incremented stats */ 2355 goto freeit; 2356 } 2357 2358 if (ndopts.nd_opts_tgt_lladdr) { 2359 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 2360 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 2361 } 2362 2363 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 2364 nd6log((LOG_INFO, "%s: lladdrlen mismatch for %s " 2365 "(if %d, icmp6 packet %d): %s\n", 2366 __func__, ip6_sprintf(ip6buf, &redtgt6), 2367 ifp->if_addrlen, lladdrlen - 2, 2368 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2369 goto bad; 2370 } 2371 2372 /* Validation passed. */ 2373 2374 /* RFC 2461 8.3 */ 2375 nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT, 2376 is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER); 2377 2378 /* 2379 * Install a gateway route in the better-router case or an interface 2380 * route in the on-link-destination case. 2381 */ 2382 { 2383 struct sockaddr_in6 sdst; 2384 struct sockaddr_in6 sgw; 2385 struct sockaddr_in6 ssrc; 2386 struct sockaddr *gw; 2387 int rt_flags; 2388 u_int fibnum; 2389 2390 bzero(&sdst, sizeof(sdst)); 2391 bzero(&ssrc, sizeof(ssrc)); 2392 sdst.sin6_family = ssrc.sin6_family = AF_INET6; 2393 sdst.sin6_len = ssrc.sin6_len = sizeof(struct sockaddr_in6); 2394 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr)); 2395 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr)); 2396 rt_flags = RTF_HOST; 2397 if (is_router) { 2398 bzero(&sgw, sizeof(sgw)); 2399 sgw.sin6_family = AF_INET6; 2400 sgw.sin6_len = sizeof(struct sockaddr_in6); 2401 bcopy(&redtgt6, &sgw.sin6_addr, 2402 sizeof(struct in6_addr)); 2403 gw = (struct sockaddr *)&sgw; 2404 rt_flags |= RTF_GATEWAY; 2405 } else 2406 gw = ifp->if_addr->ifa_addr; 2407 for (fibnum = 0; fibnum < rt_numfibs; fibnum++) 2408 in6_rtredirect((struct sockaddr *)&sdst, gw, 2409 (struct sockaddr *)NULL, rt_flags, 2410 (struct sockaddr *)&ssrc, fibnum); 2411 } 2412 /* finally update cached route in each socket via pfctlinput */ 2413 { 2414 struct sockaddr_in6 sdst; 2415 2416 bzero(&sdst, sizeof(sdst)); 2417 sdst.sin6_family = AF_INET6; 2418 sdst.sin6_len = sizeof(struct sockaddr_in6); 2419 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr)); 2420 pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst); 2421 } 2422 2423 freeit: 2424 m_freem(m); 2425 return; 2426 2427 bad: 2428 ICMP6STAT_INC(icp6s_badredirect); 2429 m_freem(m); 2430 } 2431 2432 void 2433 icmp6_redirect_output(struct mbuf *m0, struct rtentry *rt) 2434 { 2435 struct ifnet *ifp; /* my outgoing interface */ 2436 struct in6_addr *ifp_ll6; 2437 struct in6_addr *router_ll6; 2438 struct ip6_hdr *sip6; /* m0 as struct ip6_hdr */ 2439 struct mbuf *m = NULL; /* newly allocated one */ 2440 struct m_tag *mtag; 2441 struct ip6_hdr *ip6; /* m as struct ip6_hdr */ 2442 struct nd_redirect *nd_rd; 2443 struct llentry *ln = NULL; 2444 size_t maxlen; 2445 u_char *p; 2446 struct ifnet *outif = NULL; 2447 struct sockaddr_in6 src_sa; 2448 2449 icmp6_errcount(ND_REDIRECT, 0); 2450 2451 /* if we are not router, we don't send icmp6 redirect */ 2452 if (!V_ip6_forwarding) 2453 goto fail; 2454 2455 /* sanity check */ 2456 if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp)) 2457 goto fail; 2458 2459 /* 2460 * Address check: 2461 * the source address must identify a neighbor, and 2462 * the destination address must not be a multicast address 2463 * [RFC 2461, sec 8.2] 2464 */ 2465 sip6 = mtod(m0, struct ip6_hdr *); 2466 bzero(&src_sa, sizeof(src_sa)); 2467 src_sa.sin6_family = AF_INET6; 2468 src_sa.sin6_len = sizeof(src_sa); 2469 src_sa.sin6_addr = sip6->ip6_src; 2470 if (nd6_is_addr_neighbor(&src_sa, ifp) == 0) 2471 goto fail; 2472 if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst)) 2473 goto fail; /* what should we do here? */ 2474 2475 /* rate limit */ 2476 if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0)) 2477 goto fail; 2478 2479 /* 2480 * Since we are going to append up to 1280 bytes (= IPV6_MMTU), 2481 * we almost always ask for an mbuf cluster for simplicity. 2482 * (MHLEN < IPV6_MMTU is almost always true) 2483 */ 2484 #if IPV6_MMTU >= MCLBYTES 2485 # error assumption failed about IPV6_MMTU and MCLBYTES 2486 #endif 2487 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 2488 if (m == NULL) 2489 goto fail; 2490 M_SETFIB(m, rt->rt_fibnum); 2491 maxlen = M_TRAILINGSPACE(m); 2492 maxlen = min(IPV6_MMTU, maxlen); 2493 /* just for safety */ 2494 if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) + 2495 ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) { 2496 goto fail; 2497 } 2498 2499 { 2500 /* get ip6 linklocal address for ifp(my outgoing interface). */ 2501 struct in6_ifaddr *ia; 2502 if ((ia = in6ifa_ifpforlinklocal(ifp, 2503 IN6_IFF_NOTREADY| 2504 IN6_IFF_ANYCAST)) == NULL) 2505 goto fail; 2506 ifp_ll6 = &ia->ia_addr.sin6_addr; 2507 /* XXXRW: reference released prematurely. */ 2508 ifa_free(&ia->ia_ifa); 2509 } 2510 2511 /* get ip6 linklocal address for the router. */ 2512 if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) { 2513 struct sockaddr_in6 *sin6; 2514 sin6 = (struct sockaddr_in6 *)rt->rt_gateway; 2515 router_ll6 = &sin6->sin6_addr; 2516 if (!IN6_IS_ADDR_LINKLOCAL(router_ll6)) 2517 router_ll6 = (struct in6_addr *)NULL; 2518 } else 2519 router_ll6 = (struct in6_addr *)NULL; 2520 2521 /* ip6 */ 2522 ip6 = mtod(m, struct ip6_hdr *); 2523 ip6->ip6_flow = 0; 2524 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2525 ip6->ip6_vfc |= IPV6_VERSION; 2526 /* ip6->ip6_plen will be set later */ 2527 ip6->ip6_nxt = IPPROTO_ICMPV6; 2528 ip6->ip6_hlim = 255; 2529 /* ip6->ip6_src must be linklocal addr for my outgoing if. */ 2530 bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr)); 2531 bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr)); 2532 2533 /* ND Redirect */ 2534 nd_rd = (struct nd_redirect *)(ip6 + 1); 2535 nd_rd->nd_rd_type = ND_REDIRECT; 2536 nd_rd->nd_rd_code = 0; 2537 nd_rd->nd_rd_reserved = 0; 2538 if (rt->rt_flags & RTF_GATEWAY) { 2539 /* 2540 * nd_rd->nd_rd_target must be a link-local address in 2541 * better router cases. 2542 */ 2543 if (!router_ll6) 2544 goto fail; 2545 bcopy(router_ll6, &nd_rd->nd_rd_target, 2546 sizeof(nd_rd->nd_rd_target)); 2547 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2548 sizeof(nd_rd->nd_rd_dst)); 2549 } else { 2550 /* make sure redtgt == reddst */ 2551 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target, 2552 sizeof(nd_rd->nd_rd_target)); 2553 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2554 sizeof(nd_rd->nd_rd_dst)); 2555 } 2556 2557 p = (u_char *)(nd_rd + 1); 2558 2559 if (!router_ll6) 2560 goto nolladdropt; 2561 2562 { 2563 /* target lladdr option */ 2564 int len; 2565 struct nd_opt_hdr *nd_opt; 2566 char *lladdr; 2567 2568 IF_AFDATA_RLOCK(ifp); 2569 ln = nd6_lookup(router_ll6, 0, ifp); 2570 IF_AFDATA_RUNLOCK(ifp); 2571 if (ln == NULL) 2572 goto nolladdropt; 2573 2574 len = sizeof(*nd_opt) + ifp->if_addrlen; 2575 len = (len + 7) & ~7; /* round by 8 */ 2576 /* safety check */ 2577 if (len + (p - (u_char *)ip6) > maxlen) 2578 goto nolladdropt; 2579 2580 if (ln->la_flags & LLE_VALID) { 2581 nd_opt = (struct nd_opt_hdr *)p; 2582 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 2583 nd_opt->nd_opt_len = len >> 3; 2584 lladdr = (char *)(nd_opt + 1); 2585 bcopy(ln->ll_addr, lladdr, ifp->if_addrlen); 2586 p += len; 2587 } 2588 } 2589 nolladdropt: 2590 if (ln != NULL) 2591 LLE_RUNLOCK(ln); 2592 2593 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2594 2595 /* just to be safe */ 2596 #ifdef M_DECRYPTED /*not openbsd*/ 2597 if (m0->m_flags & M_DECRYPTED) 2598 goto noredhdropt; 2599 #endif 2600 if (p - (u_char *)ip6 > maxlen) 2601 goto noredhdropt; 2602 2603 { 2604 /* redirected header option */ 2605 int len; 2606 struct nd_opt_rd_hdr *nd_opt_rh; 2607 2608 /* 2609 * compute the maximum size for icmp6 redirect header option. 2610 * XXX room for auth header? 2611 */ 2612 len = maxlen - (p - (u_char *)ip6); 2613 len &= ~7; 2614 2615 /* This is just for simplicity. */ 2616 if (m0->m_pkthdr.len != m0->m_len) { 2617 if (m0->m_next) { 2618 m_freem(m0->m_next); 2619 m0->m_next = NULL; 2620 } 2621 m0->m_pkthdr.len = m0->m_len; 2622 } 2623 2624 /* 2625 * Redirected header option spec (RFC2461 4.6.3) talks nothing 2626 * about padding/truncate rule for the original IP packet. 2627 * From the discussion on IPv6imp in Feb 1999, 2628 * the consensus was: 2629 * - "attach as much as possible" is the goal 2630 * - pad if not aligned (original size can be guessed by 2631 * original ip6 header) 2632 * Following code adds the padding if it is simple enough, 2633 * and truncates if not. 2634 */ 2635 if (m0->m_next || m0->m_pkthdr.len != m0->m_len) 2636 panic("assumption failed in %s:%d", __FILE__, 2637 __LINE__); 2638 2639 if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) { 2640 /* not enough room, truncate */ 2641 m0->m_pkthdr.len = m0->m_len = len - 2642 sizeof(*nd_opt_rh); 2643 } else { 2644 /* enough room, pad or truncate */ 2645 size_t extra; 2646 2647 extra = m0->m_pkthdr.len % 8; 2648 if (extra) { 2649 /* pad if easy enough, truncate if not */ 2650 if (8 - extra <= M_TRAILINGSPACE(m0)) { 2651 /* pad */ 2652 m0->m_len += (8 - extra); 2653 m0->m_pkthdr.len += (8 - extra); 2654 } else { 2655 /* truncate */ 2656 m0->m_pkthdr.len -= extra; 2657 m0->m_len -= extra; 2658 } 2659 } 2660 len = m0->m_pkthdr.len + sizeof(*nd_opt_rh); 2661 m0->m_pkthdr.len = m0->m_len = len - 2662 sizeof(*nd_opt_rh); 2663 } 2664 2665 nd_opt_rh = (struct nd_opt_rd_hdr *)p; 2666 bzero(nd_opt_rh, sizeof(*nd_opt_rh)); 2667 nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER; 2668 nd_opt_rh->nd_opt_rh_len = len >> 3; 2669 p += sizeof(*nd_opt_rh); 2670 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2671 2672 /* connect m0 to m */ 2673 m_tag_delete_chain(m0, NULL); 2674 m0->m_flags &= ~M_PKTHDR; 2675 m->m_next = m0; 2676 m->m_pkthdr.len = m->m_len + m0->m_len; 2677 m0 = NULL; 2678 } 2679 noredhdropt:; 2680 if (m0) { 2681 m_freem(m0); 2682 m0 = NULL; 2683 } 2684 2685 /* XXX: clear embedded link IDs in the inner header */ 2686 in6_clearscope(&sip6->ip6_src); 2687 in6_clearscope(&sip6->ip6_dst); 2688 in6_clearscope(&nd_rd->nd_rd_target); 2689 in6_clearscope(&nd_rd->nd_rd_dst); 2690 2691 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr)); 2692 2693 nd_rd->nd_rd_cksum = 0; 2694 nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2695 sizeof(*ip6), ntohs(ip6->ip6_plen)); 2696 2697 if (send_sendso_input_hook != NULL) { 2698 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, sizeof(unsigned short), 2699 M_NOWAIT); 2700 if (mtag == NULL) 2701 goto fail; 2702 *(unsigned short *)(mtag + 1) = nd_rd->nd_rd_type; 2703 m_tag_prepend(m, mtag); 2704 } 2705 2706 /* send the packet to outside... */ 2707 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2708 if (outif) { 2709 icmp6_ifstat_inc(outif, ifs6_out_msg); 2710 icmp6_ifstat_inc(outif, ifs6_out_redirect); 2711 } 2712 ICMP6STAT_INC(icp6s_outhist[ND_REDIRECT]); 2713 2714 return; 2715 2716 fail: 2717 if (m) 2718 m_freem(m); 2719 if (m0) 2720 m_freem(m0); 2721 } 2722 2723 /* 2724 * ICMPv6 socket option processing. 2725 */ 2726 int 2727 icmp6_ctloutput(struct socket *so, struct sockopt *sopt) 2728 { 2729 int error = 0; 2730 int optlen; 2731 struct inpcb *inp = sotoinpcb(so); 2732 int level, op, optname; 2733 2734 if (sopt) { 2735 level = sopt->sopt_level; 2736 op = sopt->sopt_dir; 2737 optname = sopt->sopt_name; 2738 optlen = sopt->sopt_valsize; 2739 } else 2740 level = op = optname = optlen = 0; 2741 2742 if (level != IPPROTO_ICMPV6) { 2743 return EINVAL; 2744 } 2745 2746 switch (op) { 2747 case PRCO_SETOPT: 2748 switch (optname) { 2749 case ICMP6_FILTER: 2750 { 2751 struct icmp6_filter ic6f; 2752 2753 if (optlen != sizeof(ic6f)) { 2754 error = EMSGSIZE; 2755 break; 2756 } 2757 error = sooptcopyin(sopt, &ic6f, optlen, optlen); 2758 if (error == 0) { 2759 INP_WLOCK(inp); 2760 *inp->in6p_icmp6filt = ic6f; 2761 INP_WUNLOCK(inp); 2762 } 2763 break; 2764 } 2765 2766 default: 2767 error = ENOPROTOOPT; 2768 break; 2769 } 2770 break; 2771 2772 case PRCO_GETOPT: 2773 switch (optname) { 2774 case ICMP6_FILTER: 2775 { 2776 struct icmp6_filter ic6f; 2777 2778 INP_RLOCK(inp); 2779 ic6f = *inp->in6p_icmp6filt; 2780 INP_RUNLOCK(inp); 2781 error = sooptcopyout(sopt, &ic6f, sizeof(ic6f)); 2782 break; 2783 } 2784 2785 default: 2786 error = ENOPROTOOPT; 2787 break; 2788 } 2789 break; 2790 } 2791 2792 return (error); 2793 } 2794 2795 /* 2796 * Perform rate limit check. 2797 * Returns 0 if it is okay to send the icmp6 packet. 2798 * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate 2799 * limitation. 2800 * 2801 * XXX per-destination/type check necessary? 2802 * 2803 * dst - not used at this moment 2804 * type - not used at this moment 2805 * code - not used at this moment 2806 */ 2807 static int 2808 icmp6_ratelimit(const struct in6_addr *dst, const int type, 2809 const int code) 2810 { 2811 int ret; 2812 2813 ret = 0; /* okay to send */ 2814 2815 /* PPS limit */ 2816 if (!ppsratecheck(&V_icmp6errppslim_last, &V_icmp6errpps_count, 2817 V_icmp6errppslim)) { 2818 /* The packet is subject to rate limit */ 2819 ret++; 2820 } 2821 2822 return ret; 2823 }
Cache object: 7dbe1507dd1478298564490a1e182ea3
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