Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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sys/netinet6/icmp6.c
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1 /*- 2 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the project nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * $KAME: icmp6.c,v 1.211 2001/04/04 05:56:20 itojun Exp $ 30 */ 31 32 /*- 33 * Copyright (c) 1982, 1986, 1988, 1993 34 * The Regents of the University of California. All rights reserved. 35 * 36 * Redistribution and use in source and binary forms, with or without 37 * modification, are permitted provided that the following conditions 38 * are met: 39 * 1. Redistributions of source code must retain the above copyright 40 * notice, this list of conditions and the following disclaimer. 41 * 2. Redistributions in binary form must reproduce the above copyright 42 * notice, this list of conditions and the following disclaimer in the 43 * documentation and/or other materials provided with the distribution. 44 * 4. Neither the name of the University nor the names of its contributors 45 * may be used to endorse or promote products derived from this software 46 * without specific prior written permission. 47 * 48 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 49 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 50 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 51 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 52 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 53 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 54 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 55 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 56 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 57 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 58 * SUCH DAMAGE. 59 * 60 * @(#)ip_icmp.c 8.2 (Berkeley) 1/4/94 61 */ 62 63 #include <sys/cdefs.h> 64 __FBSDID("$FreeBSD: releng/11.2/sys/netinet6/icmp6.c 333206 2018-05-03 08:15:32Z ae $"); 65 66 #define MBUF_PRIVATE /* XXXRW: Optimisation tries to avoid M_EXT mbufs */ 67 68 #include "opt_inet.h" 69 #include "opt_inet6.h" 70 71 #include <sys/param.h> 72 #include <sys/domain.h> 73 #include <sys/jail.h> 74 #include <sys/kernel.h> 75 #include <sys/lock.h> 76 #include <sys/malloc.h> 77 #include <sys/mbuf.h> 78 #include <sys/proc.h> 79 #include <sys/protosw.h> 80 #include <sys/signalvar.h> 81 #include <sys/socket.h> 82 #include <sys/socketvar.h> 83 #include <sys/sx.h> 84 #include <sys/syslog.h> 85 #include <sys/systm.h> 86 #include <sys/time.h> 87 88 #include <net/if.h> 89 #include <net/if_var.h> 90 #include <net/if_dl.h> 91 #include <net/if_llatbl.h> 92 #include <net/if_types.h> 93 #include <net/route.h> 94 #include <net/vnet.h> 95 96 #include <netinet/in.h> 97 #include <netinet/in_pcb.h> 98 #include <netinet/in_var.h> 99 #include <netinet/ip6.h> 100 #include <netinet/icmp6.h> 101 #include <netinet/tcp_var.h> 102 103 #include <netinet6/in6_fib.h> 104 #include <netinet6/in6_ifattach.h> 105 #include <netinet6/in6_pcb.h> 106 #include <netinet6/ip6protosw.h> 107 #include <netinet6/ip6_var.h> 108 #include <netinet6/scope6_var.h> 109 #include <netinet6/mld6_var.h> 110 #include <netinet6/nd6.h> 111 #include <netinet6/send.h> 112 113 extern struct domain inet6domain; 114 115 VNET_PCPUSTAT_DEFINE(struct icmp6stat, icmp6stat); 116 VNET_PCPUSTAT_SYSINIT(icmp6stat); 117 118 #ifdef VIMAGE 119 VNET_PCPUSTAT_SYSUNINIT(icmp6stat); 120 #endif /* VIMAGE */ 121 122 VNET_DECLARE(struct inpcbinfo, ripcbinfo); 123 VNET_DECLARE(struct inpcbhead, ripcb); 124 VNET_DECLARE(int, icmp6errppslim); 125 static VNET_DEFINE(int, icmp6errpps_count) = 0; 126 static VNET_DEFINE(struct timeval, icmp6errppslim_last); 127 VNET_DECLARE(int, icmp6_nodeinfo); 128 129 #define V_ripcbinfo VNET(ripcbinfo) 130 #define V_ripcb VNET(ripcb) 131 #define V_icmp6errppslim VNET(icmp6errppslim) 132 #define V_icmp6errpps_count VNET(icmp6errpps_count) 133 #define V_icmp6errppslim_last VNET(icmp6errppslim_last) 134 #define V_icmp6_nodeinfo VNET(icmp6_nodeinfo) 135 136 static void icmp6_errcount(int, int); 137 static int icmp6_rip6_input(struct mbuf **, int); 138 static int icmp6_ratelimit(const struct in6_addr *, const int, const int); 139 static const char *icmp6_redirect_diag(struct in6_addr *, 140 struct in6_addr *, struct in6_addr *); 141 static struct mbuf *ni6_input(struct mbuf *, int); 142 static struct mbuf *ni6_nametodns(const char *, int, int); 143 static int ni6_dnsmatch(const char *, int, const char *, int); 144 static int ni6_addrs(struct icmp6_nodeinfo *, struct mbuf *, 145 struct ifnet **, struct in6_addr *); 146 static int ni6_store_addrs(struct icmp6_nodeinfo *, struct icmp6_nodeinfo *, 147 struct ifnet *, int); 148 static int icmp6_notify_error(struct mbuf **, int, int, int); 149 150 /* 151 * Kernel module interface for updating icmp6stat. The argument is an index 152 * into icmp6stat treated as an array of u_quad_t. While this encodes the 153 * general layout of icmp6stat into the caller, it doesn't encode its 154 * location, so that future changes to add, for example, per-CPU stats 155 * support won't cause binary compatibility problems for kernel modules. 156 */ 157 void 158 kmod_icmp6stat_inc(int statnum) 159 { 160 161 counter_u64_add(VNET(icmp6stat)[statnum], 1); 162 } 163 164 static void 165 icmp6_errcount(int type, int code) 166 { 167 switch (type) { 168 case ICMP6_DST_UNREACH: 169 switch (code) { 170 case ICMP6_DST_UNREACH_NOROUTE: 171 ICMP6STAT_INC(icp6s_odst_unreach_noroute); 172 return; 173 case ICMP6_DST_UNREACH_ADMIN: 174 ICMP6STAT_INC(icp6s_odst_unreach_admin); 175 return; 176 case ICMP6_DST_UNREACH_BEYONDSCOPE: 177 ICMP6STAT_INC(icp6s_odst_unreach_beyondscope); 178 return; 179 case ICMP6_DST_UNREACH_ADDR: 180 ICMP6STAT_INC(icp6s_odst_unreach_addr); 181 return; 182 case ICMP6_DST_UNREACH_NOPORT: 183 ICMP6STAT_INC(icp6s_odst_unreach_noport); 184 return; 185 } 186 break; 187 case ICMP6_PACKET_TOO_BIG: 188 ICMP6STAT_INC(icp6s_opacket_too_big); 189 return; 190 case ICMP6_TIME_EXCEEDED: 191 switch (code) { 192 case ICMP6_TIME_EXCEED_TRANSIT: 193 ICMP6STAT_INC(icp6s_otime_exceed_transit); 194 return; 195 case ICMP6_TIME_EXCEED_REASSEMBLY: 196 ICMP6STAT_INC(icp6s_otime_exceed_reassembly); 197 return; 198 } 199 break; 200 case ICMP6_PARAM_PROB: 201 switch (code) { 202 case ICMP6_PARAMPROB_HEADER: 203 ICMP6STAT_INC(icp6s_oparamprob_header); 204 return; 205 case ICMP6_PARAMPROB_NEXTHEADER: 206 ICMP6STAT_INC(icp6s_oparamprob_nextheader); 207 return; 208 case ICMP6_PARAMPROB_OPTION: 209 ICMP6STAT_INC(icp6s_oparamprob_option); 210 return; 211 } 212 break; 213 case ND_REDIRECT: 214 ICMP6STAT_INC(icp6s_oredirect); 215 return; 216 } 217 ICMP6STAT_INC(icp6s_ounknown); 218 } 219 220 /* 221 * A wrapper function for icmp6_error() necessary when the erroneous packet 222 * may not contain enough scope zone information. 223 */ 224 void 225 icmp6_error2(struct mbuf *m, int type, int code, int param, 226 struct ifnet *ifp) 227 { 228 struct ip6_hdr *ip6; 229 230 if (ifp == NULL) 231 return; 232 233 #ifndef PULLDOWN_TEST 234 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), ); 235 #else 236 if (m->m_len < sizeof(struct ip6_hdr)) { 237 m = m_pullup(m, sizeof(struct ip6_hdr)); 238 if (m == NULL) 239 return; 240 } 241 #endif 242 243 ip6 = mtod(m, struct ip6_hdr *); 244 245 if (in6_setscope(&ip6->ip6_src, ifp, NULL) != 0) 246 return; 247 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0) 248 return; 249 250 icmp6_error(m, type, code, param); 251 } 252 253 /* 254 * Generate an error packet of type error in response to bad IP6 packet. 255 */ 256 void 257 icmp6_error(struct mbuf *m, int type, int code, int param) 258 { 259 struct ip6_hdr *oip6, *nip6; 260 struct icmp6_hdr *icmp6; 261 u_int preplen; 262 int off; 263 int nxt; 264 265 ICMP6STAT_INC(icp6s_error); 266 267 /* count per-type-code statistics */ 268 icmp6_errcount(type, code); 269 270 #ifdef M_DECRYPTED /*not openbsd*/ 271 if (m->m_flags & M_DECRYPTED) { 272 ICMP6STAT_INC(icp6s_canterror); 273 goto freeit; 274 } 275 #endif 276 277 #ifndef PULLDOWN_TEST 278 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), ); 279 #else 280 if (m->m_len < sizeof(struct ip6_hdr)) { 281 m = m_pullup(m, sizeof(struct ip6_hdr)); 282 if (m == NULL) 283 return; 284 } 285 #endif 286 oip6 = mtod(m, struct ip6_hdr *); 287 288 /* 289 * If the destination address of the erroneous packet is a multicast 290 * address, or the packet was sent using link-layer multicast, 291 * we should basically suppress sending an error (RFC 2463, Section 292 * 2.4). 293 * We have two exceptions (the item e.2 in that section): 294 * - the Packet Too Big message can be sent for path MTU discovery. 295 * - the Parameter Problem Message that can be allowed an icmp6 error 296 * in the option type field. This check has been done in 297 * ip6_unknown_opt(), so we can just check the type and code. 298 */ 299 if ((m->m_flags & (M_BCAST|M_MCAST) || 300 IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) && 301 (type != ICMP6_PACKET_TOO_BIG && 302 (type != ICMP6_PARAM_PROB || 303 code != ICMP6_PARAMPROB_OPTION))) 304 goto freeit; 305 306 /* 307 * RFC 2463, 2.4 (e.5): source address check. 308 * XXX: the case of anycast source? 309 */ 310 if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) || 311 IN6_IS_ADDR_MULTICAST(&oip6->ip6_src)) 312 goto freeit; 313 314 /* 315 * If we are about to send ICMPv6 against ICMPv6 error/redirect, 316 * don't do it. 317 */ 318 nxt = -1; 319 off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt); 320 if (off >= 0 && nxt == IPPROTO_ICMPV6) { 321 struct icmp6_hdr *icp; 322 323 #ifndef PULLDOWN_TEST 324 IP6_EXTHDR_CHECK(m, 0, off + sizeof(struct icmp6_hdr), ); 325 icp = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 326 #else 327 IP6_EXTHDR_GET(icp, struct icmp6_hdr *, m, off, 328 sizeof(*icp)); 329 if (icp == NULL) { 330 ICMP6STAT_INC(icp6s_tooshort); 331 return; 332 } 333 #endif 334 if (icp->icmp6_type < ICMP6_ECHO_REQUEST || 335 icp->icmp6_type == ND_REDIRECT) { 336 /* 337 * ICMPv6 error 338 * Special case: for redirect (which is 339 * informational) we must not send icmp6 error. 340 */ 341 ICMP6STAT_INC(icp6s_canterror); 342 goto freeit; 343 } else { 344 /* ICMPv6 informational - send the error */ 345 } 346 } else { 347 /* non-ICMPv6 - send the error */ 348 } 349 350 oip6 = mtod(m, struct ip6_hdr *); /* adjust pointer */ 351 352 /* Finally, do rate limitation check. */ 353 if (icmp6_ratelimit(&oip6->ip6_src, type, code)) { 354 ICMP6STAT_INC(icp6s_toofreq); 355 goto freeit; 356 } 357 358 /* 359 * OK, ICMP6 can be generated. 360 */ 361 362 if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN) 363 m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len); 364 365 preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 366 M_PREPEND(m, preplen, M_NOWAIT); /* FIB is also copied over. */ 367 if (m == NULL) { 368 nd6log((LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__)); 369 return; 370 } 371 372 nip6 = mtod(m, struct ip6_hdr *); 373 nip6->ip6_src = oip6->ip6_src; 374 nip6->ip6_dst = oip6->ip6_dst; 375 376 in6_clearscope(&oip6->ip6_src); 377 in6_clearscope(&oip6->ip6_dst); 378 379 icmp6 = (struct icmp6_hdr *)(nip6 + 1); 380 icmp6->icmp6_type = type; 381 icmp6->icmp6_code = code; 382 icmp6->icmp6_pptr = htonl((u_int32_t)param); 383 384 ICMP6STAT_INC(icp6s_outhist[type]); 385 icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */ 386 387 return; 388 389 freeit: 390 /* 391 * If we can't tell whether or not we can generate ICMP6, free it. 392 */ 393 m_freem(m); 394 } 395 396 /* 397 * Process a received ICMP6 message. 398 */ 399 int 400 icmp6_input(struct mbuf **mp, int *offp, int proto) 401 { 402 struct mbuf *m = *mp, *n; 403 struct ifnet *ifp; 404 struct ip6_hdr *ip6, *nip6; 405 struct icmp6_hdr *icmp6, *nicmp6; 406 int off = *offp; 407 int icmp6len = m->m_pkthdr.len - *offp; 408 int code, sum, noff; 409 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 410 int ip6len, error; 411 412 ifp = m->m_pkthdr.rcvif; 413 414 #ifndef PULLDOWN_TEST 415 IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_hdr), IPPROTO_DONE); 416 /* m might change if M_LOOP. So, call mtod after this */ 417 #endif 418 419 /* 420 * Locate icmp6 structure in mbuf, and check 421 * that not corrupted and of at least minimum length 422 */ 423 424 ip6 = mtod(m, struct ip6_hdr *); 425 ip6len = sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen); 426 if (icmp6len < sizeof(struct icmp6_hdr)) { 427 ICMP6STAT_INC(icp6s_tooshort); 428 goto freeit; 429 } 430 431 /* 432 * Check multicast group membership. 433 * Note: SSM filters are not applied for ICMPv6 traffic. 434 */ 435 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 436 struct in6_multi *inm; 437 438 inm = in6m_lookup(ifp, &ip6->ip6_dst); 439 if (inm == NULL) { 440 IP6STAT_INC(ip6s_notmember); 441 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 442 goto freeit; 443 } 444 } 445 446 /* 447 * calculate the checksum 448 */ 449 #ifndef PULLDOWN_TEST 450 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off); 451 #else 452 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6)); 453 if (icmp6 == NULL) { 454 ICMP6STAT_INC(icp6s_tooshort); 455 return IPPROTO_DONE; 456 } 457 #endif 458 code = icmp6->icmp6_code; 459 460 if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) { 461 nd6log((LOG_ERR, 462 "ICMP6 checksum error(%d|%x) %s\n", 463 icmp6->icmp6_type, sum, 464 ip6_sprintf(ip6bufs, &ip6->ip6_src))); 465 ICMP6STAT_INC(icp6s_checksum); 466 goto freeit; 467 } 468 469 ICMP6STAT_INC(icp6s_inhist[icmp6->icmp6_type]); 470 icmp6_ifstat_inc(ifp, ifs6_in_msg); 471 if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK) 472 icmp6_ifstat_inc(ifp, ifs6_in_error); 473 474 switch (icmp6->icmp6_type) { 475 case ICMP6_DST_UNREACH: 476 icmp6_ifstat_inc(ifp, ifs6_in_dstunreach); 477 switch (code) { 478 case ICMP6_DST_UNREACH_NOROUTE: 479 case ICMP6_DST_UNREACH_ADDR: /* PRC_HOSTDEAD is a DOS */ 480 code = PRC_UNREACH_NET; 481 break; 482 case ICMP6_DST_UNREACH_ADMIN: 483 icmp6_ifstat_inc(ifp, ifs6_in_adminprohib); 484 code = PRC_UNREACH_ADMIN_PROHIB; 485 break; 486 case ICMP6_DST_UNREACH_BEYONDSCOPE: 487 /* I mean "source address was incorrect." */ 488 code = PRC_PARAMPROB; 489 break; 490 case ICMP6_DST_UNREACH_NOPORT: 491 code = PRC_UNREACH_PORT; 492 break; 493 default: 494 goto badcode; 495 } 496 goto deliver; 497 break; 498 499 case ICMP6_PACKET_TOO_BIG: 500 icmp6_ifstat_inc(ifp, ifs6_in_pkttoobig); 501 502 /* validation is made in icmp6_mtudisc_update */ 503 504 code = PRC_MSGSIZE; 505 506 /* 507 * Updating the path MTU will be done after examining 508 * intermediate extension headers. 509 */ 510 goto deliver; 511 break; 512 513 case ICMP6_TIME_EXCEEDED: 514 icmp6_ifstat_inc(ifp, ifs6_in_timeexceed); 515 switch (code) { 516 case ICMP6_TIME_EXCEED_TRANSIT: 517 code = PRC_TIMXCEED_INTRANS; 518 break; 519 case ICMP6_TIME_EXCEED_REASSEMBLY: 520 code = PRC_TIMXCEED_REASS; 521 break; 522 default: 523 goto badcode; 524 } 525 goto deliver; 526 break; 527 528 case ICMP6_PARAM_PROB: 529 icmp6_ifstat_inc(ifp, ifs6_in_paramprob); 530 switch (code) { 531 case ICMP6_PARAMPROB_NEXTHEADER: 532 code = PRC_UNREACH_PROTOCOL; 533 break; 534 case ICMP6_PARAMPROB_HEADER: 535 case ICMP6_PARAMPROB_OPTION: 536 code = PRC_PARAMPROB; 537 break; 538 default: 539 goto badcode; 540 } 541 goto deliver; 542 break; 543 544 case ICMP6_ECHO_REQUEST: 545 icmp6_ifstat_inc(ifp, ifs6_in_echo); 546 if (code != 0) 547 goto badcode; 548 if ((n = m_copy(m, 0, M_COPYALL)) == NULL) { 549 /* Give up remote */ 550 break; 551 } 552 if (!M_WRITABLE(n) 553 || n->m_len < off + sizeof(struct icmp6_hdr)) { 554 struct mbuf *n0 = n; 555 int n0len; 556 557 CTASSERT(sizeof(*nip6) + sizeof(*nicmp6) <= MHLEN); 558 n = m_gethdr(M_NOWAIT, n0->m_type); 559 if (n == NULL) { 560 /* Give up remote */ 561 m_freem(n0); 562 break; 563 } 564 565 m_move_pkthdr(n, n0); /* FIB copied. */ 566 n0len = n0->m_pkthdr.len; /* save for use below */ 567 /* 568 * Copy IPv6 and ICMPv6 only. 569 */ 570 nip6 = mtod(n, struct ip6_hdr *); 571 bcopy(ip6, nip6, sizeof(struct ip6_hdr)); 572 nicmp6 = (struct icmp6_hdr *)(nip6 + 1); 573 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr)); 574 noff = sizeof(struct ip6_hdr); 575 /* new mbuf contains only ipv6+icmpv6 headers */ 576 n->m_len = noff + sizeof(struct icmp6_hdr); 577 /* 578 * Adjust mbuf. ip6_plen will be adjusted in 579 * ip6_output(). 580 */ 581 m_adj(n0, off + sizeof(struct icmp6_hdr)); 582 /* recalculate complete packet size */ 583 n->m_pkthdr.len = n0len + (noff - off); 584 n->m_next = n0; 585 } else { 586 IP6_EXTHDR_GET(nicmp6, struct icmp6_hdr *, n, off, 587 sizeof(*nicmp6)); 588 noff = off; 589 } 590 if (n) { 591 nicmp6->icmp6_type = ICMP6_ECHO_REPLY; 592 nicmp6->icmp6_code = 0; 593 ICMP6STAT_INC(icp6s_reflect); 594 ICMP6STAT_INC(icp6s_outhist[ICMP6_ECHO_REPLY]); 595 icmp6_reflect(n, noff); 596 } 597 break; 598 599 case ICMP6_ECHO_REPLY: 600 icmp6_ifstat_inc(ifp, ifs6_in_echoreply); 601 if (code != 0) 602 goto badcode; 603 break; 604 605 case MLD_LISTENER_QUERY: 606 case MLD_LISTENER_REPORT: 607 case MLD_LISTENER_DONE: 608 case MLDV2_LISTENER_REPORT: 609 /* 610 * Drop MLD traffic which is not link-local, has a hop limit 611 * of greater than 1 hop, or which does not have the 612 * IPv6 HBH Router Alert option. 613 * As IPv6 HBH options are stripped in ip6_input() we must 614 * check an mbuf header flag. 615 * XXX Should we also sanity check that these messages 616 * were directed to a link-local multicast prefix? 617 */ 618 if ((ip6->ip6_hlim != 1) || (m->m_flags & M_RTALERT_MLD) == 0) 619 goto freeit; 620 if (mld_input(m, off, icmp6len) != 0) 621 return (IPPROTO_DONE); 622 /* m stays. */ 623 break; 624 625 case ICMP6_WRUREQUEST: /* ICMP6_FQDN_QUERY */ 626 { 627 enum { WRU, FQDN } mode; 628 629 if (!V_icmp6_nodeinfo) 630 break; 631 632 if (icmp6len == sizeof(struct icmp6_hdr) + 4) 633 mode = WRU; 634 else if (icmp6len >= sizeof(struct icmp6_nodeinfo)) 635 mode = FQDN; 636 else 637 goto badlen; 638 639 if (mode == FQDN) { 640 #ifndef PULLDOWN_TEST 641 IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_nodeinfo), 642 IPPROTO_DONE); 643 #endif 644 n = m_copy(m, 0, M_COPYALL); 645 if (n) 646 n = ni6_input(n, off); 647 /* XXX meaningless if n == NULL */ 648 noff = sizeof(struct ip6_hdr); 649 } else { 650 struct prison *pr; 651 u_char *p; 652 int maxhlen, hlen; 653 654 /* 655 * XXX: this combination of flags is pointless, 656 * but should we keep this for compatibility? 657 */ 658 if ((V_icmp6_nodeinfo & (ICMP6_NODEINFO_FQDNOK | 659 ICMP6_NODEINFO_TMPADDROK)) != 660 (ICMP6_NODEINFO_FQDNOK | ICMP6_NODEINFO_TMPADDROK)) 661 break; 662 663 if (code != 0) 664 goto badcode; 665 666 CTASSERT(sizeof(*nip6) + sizeof(*nicmp6) + 4 <= MHLEN); 667 n = m_gethdr(M_NOWAIT, m->m_type); 668 if (n == NULL) { 669 /* Give up remote */ 670 break; 671 } 672 if (!m_dup_pkthdr(n, m, M_NOWAIT)) { 673 /* 674 * Previous code did a blind M_COPY_PKTHDR 675 * and said "just for rcvif". If true, then 676 * we could tolerate the dup failing (due to 677 * the deep copy of the tag chain). For now 678 * be conservative and just fail. 679 */ 680 m_free(n); 681 n = NULL; 682 break; 683 } 684 maxhlen = M_TRAILINGSPACE(n) - 685 (sizeof(*nip6) + sizeof(*nicmp6) + 4); 686 pr = curthread->td_ucred->cr_prison; 687 mtx_lock(&pr->pr_mtx); 688 hlen = strlen(pr->pr_hostname); 689 if (maxhlen > hlen) 690 maxhlen = hlen; 691 /* 692 * Copy IPv6 and ICMPv6 only. 693 */ 694 nip6 = mtod(n, struct ip6_hdr *); 695 bcopy(ip6, nip6, sizeof(struct ip6_hdr)); 696 nicmp6 = (struct icmp6_hdr *)(nip6 + 1); 697 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr)); 698 p = (u_char *)(nicmp6 + 1); 699 bzero(p, 4); 700 /* meaningless TTL */ 701 bcopy(pr->pr_hostname, p + 4, maxhlen); 702 mtx_unlock(&pr->pr_mtx); 703 noff = sizeof(struct ip6_hdr); 704 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + 705 sizeof(struct icmp6_hdr) + 4 + maxhlen; 706 nicmp6->icmp6_type = ICMP6_WRUREPLY; 707 nicmp6->icmp6_code = 0; 708 } 709 if (n) { 710 ICMP6STAT_INC(icp6s_reflect); 711 ICMP6STAT_INC(icp6s_outhist[ICMP6_WRUREPLY]); 712 icmp6_reflect(n, noff); 713 } 714 break; 715 } 716 717 case ICMP6_WRUREPLY: 718 if (code != 0) 719 goto badcode; 720 break; 721 722 case ND_ROUTER_SOLICIT: 723 icmp6_ifstat_inc(ifp, ifs6_in_routersolicit); 724 if (code != 0) 725 goto badcode; 726 if (icmp6len < sizeof(struct nd_router_solicit)) 727 goto badlen; 728 if (send_sendso_input_hook != NULL) { 729 IP6_EXTHDR_CHECK(m, off, icmp6len, IPPROTO_DONE); 730 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 731 if (error == 0) { 732 m = NULL; 733 goto freeit; 734 } 735 } 736 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 737 nd6_rs_input(m, off, icmp6len); 738 m = n; 739 if (m == NULL) 740 goto freeit; 741 break; 742 743 case ND_ROUTER_ADVERT: 744 icmp6_ifstat_inc(ifp, ifs6_in_routeradvert); 745 if (code != 0) 746 goto badcode; 747 if (icmp6len < sizeof(struct nd_router_advert)) 748 goto badlen; 749 if (send_sendso_input_hook != NULL) { 750 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 751 if (error == 0) { 752 m = NULL; 753 goto freeit; 754 } 755 } 756 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 757 nd6_ra_input(m, off, icmp6len); 758 m = n; 759 if (m == NULL) 760 goto freeit; 761 break; 762 763 case ND_NEIGHBOR_SOLICIT: 764 icmp6_ifstat_inc(ifp, ifs6_in_neighborsolicit); 765 if (code != 0) 766 goto badcode; 767 if (icmp6len < sizeof(struct nd_neighbor_solicit)) 768 goto badlen; 769 if (send_sendso_input_hook != NULL) { 770 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 771 if (error == 0) { 772 m = NULL; 773 goto freeit; 774 } 775 } 776 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 777 nd6_ns_input(m, off, icmp6len); 778 m = n; 779 if (m == NULL) 780 goto freeit; 781 break; 782 783 case ND_NEIGHBOR_ADVERT: 784 icmp6_ifstat_inc(ifp, ifs6_in_neighboradvert); 785 if (code != 0) 786 goto badcode; 787 if (icmp6len < sizeof(struct nd_neighbor_advert)) 788 goto badlen; 789 if (send_sendso_input_hook != NULL) { 790 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 791 if (error == 0) { 792 m = NULL; 793 goto freeit; 794 } 795 } 796 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 797 nd6_na_input(m, off, icmp6len); 798 m = n; 799 if (m == NULL) 800 goto freeit; 801 break; 802 803 case ND_REDIRECT: 804 icmp6_ifstat_inc(ifp, ifs6_in_redirect); 805 if (code != 0) 806 goto badcode; 807 if (icmp6len < sizeof(struct nd_redirect)) 808 goto badlen; 809 if (send_sendso_input_hook != NULL) { 810 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 811 if (error == 0) { 812 m = NULL; 813 goto freeit; 814 } 815 } 816 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 817 icmp6_redirect_input(m, off); 818 m = n; 819 if (m == NULL) 820 goto freeit; 821 break; 822 823 case ICMP6_ROUTER_RENUMBERING: 824 if (code != ICMP6_ROUTER_RENUMBERING_COMMAND && 825 code != ICMP6_ROUTER_RENUMBERING_RESULT) 826 goto badcode; 827 if (icmp6len < sizeof(struct icmp6_router_renum)) 828 goto badlen; 829 break; 830 831 default: 832 nd6log((LOG_DEBUG, 833 "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n", 834 icmp6->icmp6_type, ip6_sprintf(ip6bufs, &ip6->ip6_src), 835 ip6_sprintf(ip6bufd, &ip6->ip6_dst), 836 ifp ? ifp->if_index : 0)); 837 if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) { 838 /* ICMPv6 error: MUST deliver it by spec... */ 839 code = PRC_NCMDS; 840 /* deliver */ 841 } else { 842 /* ICMPv6 informational: MUST not deliver */ 843 break; 844 } 845 deliver: 846 if (icmp6_notify_error(&m, off, icmp6len, code) != 0) { 847 /* In this case, m should've been freed. */ 848 return (IPPROTO_DONE); 849 } 850 break; 851 852 badcode: 853 ICMP6STAT_INC(icp6s_badcode); 854 break; 855 856 badlen: 857 ICMP6STAT_INC(icp6s_badlen); 858 break; 859 } 860 861 /* deliver the packet to appropriate sockets */ 862 icmp6_rip6_input(&m, *offp); 863 864 return IPPROTO_DONE; 865 866 freeit: 867 m_freem(m); 868 return IPPROTO_DONE; 869 } 870 871 static int 872 icmp6_notify_error(struct mbuf **mp, int off, int icmp6len, int code) 873 { 874 struct mbuf *m = *mp; 875 struct icmp6_hdr *icmp6; 876 struct ip6_hdr *eip6; 877 u_int32_t notifymtu; 878 struct sockaddr_in6 icmp6src, icmp6dst; 879 880 if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) { 881 ICMP6STAT_INC(icp6s_tooshort); 882 goto freeit; 883 } 884 #ifndef PULLDOWN_TEST 885 IP6_EXTHDR_CHECK(m, off, 886 sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr), -1); 887 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 888 #else 889 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, 890 sizeof(*icmp6) + sizeof(struct ip6_hdr)); 891 if (icmp6 == NULL) { 892 ICMP6STAT_INC(icp6s_tooshort); 893 return (-1); 894 } 895 #endif 896 eip6 = (struct ip6_hdr *)(icmp6 + 1); 897 898 /* Detect the upper level protocol */ 899 { 900 void (*ctlfunc)(int, struct sockaddr *, void *); 901 u_int8_t nxt = eip6->ip6_nxt; 902 int eoff = off + sizeof(struct icmp6_hdr) + 903 sizeof(struct ip6_hdr); 904 struct ip6ctlparam ip6cp; 905 struct in6_addr *finaldst = NULL; 906 int icmp6type = icmp6->icmp6_type; 907 struct ip6_frag *fh; 908 struct ip6_rthdr *rth; 909 struct ip6_rthdr0 *rth0; 910 int rthlen; 911 912 while (1) { /* XXX: should avoid infinite loop explicitly? */ 913 struct ip6_ext *eh; 914 915 switch (nxt) { 916 case IPPROTO_HOPOPTS: 917 case IPPROTO_DSTOPTS: 918 case IPPROTO_AH: 919 #ifndef PULLDOWN_TEST 920 IP6_EXTHDR_CHECK(m, 0, 921 eoff + sizeof(struct ip6_ext), -1); 922 eh = (struct ip6_ext *)(mtod(m, caddr_t) + eoff); 923 #else 924 IP6_EXTHDR_GET(eh, struct ip6_ext *, m, 925 eoff, sizeof(*eh)); 926 if (eh == NULL) { 927 ICMP6STAT_INC(icp6s_tooshort); 928 return (-1); 929 } 930 #endif 931 932 if (nxt == IPPROTO_AH) 933 eoff += (eh->ip6e_len + 2) << 2; 934 else 935 eoff += (eh->ip6e_len + 1) << 3; 936 nxt = eh->ip6e_nxt; 937 break; 938 case IPPROTO_ROUTING: 939 /* 940 * When the erroneous packet contains a 941 * routing header, we should examine the 942 * header to determine the final destination. 943 * Otherwise, we can't properly update 944 * information that depends on the final 945 * destination (e.g. path MTU). 946 */ 947 #ifndef PULLDOWN_TEST 948 IP6_EXTHDR_CHECK(m, 0, eoff + sizeof(*rth), -1); 949 rth = (struct ip6_rthdr *) 950 (mtod(m, caddr_t) + eoff); 951 #else 952 IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m, 953 eoff, sizeof(*rth)); 954 if (rth == NULL) { 955 ICMP6STAT_INC(icp6s_tooshort); 956 return (-1); 957 } 958 #endif 959 rthlen = (rth->ip6r_len + 1) << 3; 960 /* 961 * XXX: currently there is no 962 * officially defined type other 963 * than type-0. 964 * Note that if the segment left field 965 * is 0, all intermediate hops must 966 * have been passed. 967 */ 968 if (rth->ip6r_segleft && 969 rth->ip6r_type == IPV6_RTHDR_TYPE_0) { 970 int hops; 971 972 #ifndef PULLDOWN_TEST 973 IP6_EXTHDR_CHECK(m, 0, eoff + rthlen, -1); 974 rth0 = (struct ip6_rthdr0 *) 975 (mtod(m, caddr_t) + eoff); 976 #else 977 IP6_EXTHDR_GET(rth0, 978 struct ip6_rthdr0 *, m, 979 eoff, rthlen); 980 if (rth0 == NULL) { 981 ICMP6STAT_INC(icp6s_tooshort); 982 return (-1); 983 } 984 #endif 985 /* just ignore a bogus header */ 986 if ((rth0->ip6r0_len % 2) == 0 && 987 (hops = rth0->ip6r0_len/2)) 988 finaldst = (struct in6_addr *)(rth0 + 1) + (hops - 1); 989 } 990 eoff += rthlen; 991 nxt = rth->ip6r_nxt; 992 break; 993 case IPPROTO_FRAGMENT: 994 #ifndef PULLDOWN_TEST 995 IP6_EXTHDR_CHECK(m, 0, eoff + 996 sizeof(struct ip6_frag), -1); 997 fh = (struct ip6_frag *)(mtod(m, caddr_t) + 998 eoff); 999 #else 1000 IP6_EXTHDR_GET(fh, struct ip6_frag *, m, 1001 eoff, sizeof(*fh)); 1002 if (fh == NULL) { 1003 ICMP6STAT_INC(icp6s_tooshort); 1004 return (-1); 1005 } 1006 #endif 1007 /* 1008 * Data after a fragment header is meaningless 1009 * unless it is the first fragment, but 1010 * we'll go to the notify label for path MTU 1011 * discovery. 1012 */ 1013 if (fh->ip6f_offlg & IP6F_OFF_MASK) 1014 goto notify; 1015 1016 eoff += sizeof(struct ip6_frag); 1017 nxt = fh->ip6f_nxt; 1018 break; 1019 default: 1020 /* 1021 * This case includes ESP and the No Next 1022 * Header. In such cases going to the notify 1023 * label does not have any meaning 1024 * (i.e. ctlfunc will be NULL), but we go 1025 * anyway since we might have to update 1026 * path MTU information. 1027 */ 1028 goto notify; 1029 } 1030 } 1031 notify: 1032 #ifndef PULLDOWN_TEST 1033 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 1034 #else 1035 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, 1036 sizeof(*icmp6) + sizeof(struct ip6_hdr)); 1037 if (icmp6 == NULL) { 1038 ICMP6STAT_INC(icp6s_tooshort); 1039 return (-1); 1040 } 1041 #endif 1042 1043 /* 1044 * retrieve parameters from the inner IPv6 header, and convert 1045 * them into sockaddr structures. 1046 * XXX: there is no guarantee that the source or destination 1047 * addresses of the inner packet are in the same scope as 1048 * the addresses of the icmp packet. But there is no other 1049 * way to determine the zone. 1050 */ 1051 eip6 = (struct ip6_hdr *)(icmp6 + 1); 1052 1053 bzero(&icmp6dst, sizeof(icmp6dst)); 1054 icmp6dst.sin6_len = sizeof(struct sockaddr_in6); 1055 icmp6dst.sin6_family = AF_INET6; 1056 if (finaldst == NULL) 1057 icmp6dst.sin6_addr = eip6->ip6_dst; 1058 else 1059 icmp6dst.sin6_addr = *finaldst; 1060 if (in6_setscope(&icmp6dst.sin6_addr, m->m_pkthdr.rcvif, NULL)) 1061 goto freeit; 1062 bzero(&icmp6src, sizeof(icmp6src)); 1063 icmp6src.sin6_len = sizeof(struct sockaddr_in6); 1064 icmp6src.sin6_family = AF_INET6; 1065 icmp6src.sin6_addr = eip6->ip6_src; 1066 if (in6_setscope(&icmp6src.sin6_addr, m->m_pkthdr.rcvif, NULL)) 1067 goto freeit; 1068 icmp6src.sin6_flowinfo = 1069 (eip6->ip6_flow & IPV6_FLOWLABEL_MASK); 1070 1071 if (finaldst == NULL) 1072 finaldst = &eip6->ip6_dst; 1073 ip6cp.ip6c_m = m; 1074 ip6cp.ip6c_icmp6 = icmp6; 1075 ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1); 1076 ip6cp.ip6c_off = eoff; 1077 ip6cp.ip6c_finaldst = finaldst; 1078 ip6cp.ip6c_src = &icmp6src; 1079 ip6cp.ip6c_nxt = nxt; 1080 1081 if (icmp6type == ICMP6_PACKET_TOO_BIG) { 1082 notifymtu = ntohl(icmp6->icmp6_mtu); 1083 ip6cp.ip6c_cmdarg = (void *)¬ifymtu; 1084 icmp6_mtudisc_update(&ip6cp, 1); /*XXX*/ 1085 } 1086 1087 ctlfunc = (void (*)(int, struct sockaddr *, void *)) 1088 (inet6sw[ip6_protox[nxt]].pr_ctlinput); 1089 if (ctlfunc) { 1090 (void) (*ctlfunc)(code, (struct sockaddr *)&icmp6dst, 1091 &ip6cp); 1092 } 1093 } 1094 *mp = m; 1095 return (0); 1096 1097 freeit: 1098 m_freem(m); 1099 return (-1); 1100 } 1101 1102 void 1103 icmp6_mtudisc_update(struct ip6ctlparam *ip6cp, int validated) 1104 { 1105 struct in6_addr *dst = ip6cp->ip6c_finaldst; 1106 struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6; 1107 struct mbuf *m = ip6cp->ip6c_m; /* will be necessary for scope issue */ 1108 u_int mtu = ntohl(icmp6->icmp6_mtu); 1109 struct in_conninfo inc; 1110 1111 #if 0 1112 /* 1113 * RFC2460 section 5, last paragraph. 1114 * even though minimum link MTU for IPv6 is IPV6_MMTU, 1115 * we may see ICMPv6 too big with mtu < IPV6_MMTU 1116 * due to packet translator in the middle. 1117 * see ip6_output() and ip6_getpmtu() "alwaysfrag" case for 1118 * special handling. 1119 */ 1120 if (mtu < IPV6_MMTU) 1121 return; 1122 #endif 1123 1124 /* 1125 * we reject ICMPv6 too big with abnormally small value. 1126 * XXX what is the good definition of "abnormally small"? 1127 */ 1128 if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8) 1129 return; 1130 1131 if (!validated) 1132 return; 1133 1134 /* 1135 * In case the suggested mtu is less than IPV6_MMTU, we 1136 * only need to remember that it was for above mentioned 1137 * "alwaysfrag" case. 1138 * Try to be as close to the spec as possible. 1139 */ 1140 if (mtu < IPV6_MMTU) 1141 mtu = IPV6_MMTU - 8; 1142 1143 bzero(&inc, sizeof(inc)); 1144 inc.inc_fibnum = M_GETFIB(m); 1145 inc.inc_flags |= INC_ISIPV6; 1146 inc.inc6_faddr = *dst; 1147 if (in6_setscope(&inc.inc6_faddr, m->m_pkthdr.rcvif, NULL)) 1148 return; 1149 1150 if (mtu < tcp_maxmtu6(&inc, NULL)) { 1151 tcp_hc_updatemtu(&inc, mtu); 1152 ICMP6STAT_INC(icp6s_pmtuchg); 1153 } 1154 } 1155 1156 /* 1157 * Process a Node Information Query packet, based on 1158 * draft-ietf-ipngwg-icmp-name-lookups-07. 1159 * 1160 * Spec incompatibilities: 1161 * - IPv6 Subject address handling 1162 * - IPv4 Subject address handling support missing 1163 * - Proxy reply (answer even if it's not for me) 1164 * - joins NI group address at in6_ifattach() time only, does not cope 1165 * with hostname changes by sethostname(3) 1166 */ 1167 static struct mbuf * 1168 ni6_input(struct mbuf *m, int off) 1169 { 1170 struct icmp6_nodeinfo *ni6, *nni6; 1171 struct mbuf *n = NULL; 1172 struct prison *pr; 1173 u_int16_t qtype; 1174 int subjlen; 1175 int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); 1176 struct ni_reply_fqdn *fqdn; 1177 int addrs; /* for NI_QTYPE_NODEADDR */ 1178 struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */ 1179 struct in6_addr in6_subj; /* subject address */ 1180 struct ip6_hdr *ip6; 1181 int oldfqdn = 0; /* if 1, return pascal string (03 draft) */ 1182 char *subj = NULL; 1183 struct in6_ifaddr *ia6 = NULL; 1184 1185 ip6 = mtod(m, struct ip6_hdr *); 1186 #ifndef PULLDOWN_TEST 1187 ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off); 1188 #else 1189 IP6_EXTHDR_GET(ni6, struct icmp6_nodeinfo *, m, off, sizeof(*ni6)); 1190 if (ni6 == NULL) { 1191 /* m is already reclaimed */ 1192 return (NULL); 1193 } 1194 #endif 1195 1196 /* 1197 * Validate IPv6 source address. 1198 * The default configuration MUST be to refuse answering queries from 1199 * global-scope addresses according to RFC4602. 1200 * Notes: 1201 * - it's not very clear what "refuse" means; this implementation 1202 * simply drops it. 1203 * - it's not very easy to identify global-scope (unicast) addresses 1204 * since there are many prefixes for them. It should be safer 1205 * and in practice sufficient to check "all" but loopback and 1206 * link-local (note that site-local unicast was deprecated and 1207 * ULA is defined as global scope-wise) 1208 */ 1209 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_GLOBALOK) == 0 && 1210 !IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) && 1211 !IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) 1212 goto bad; 1213 1214 /* 1215 * Validate IPv6 destination address. 1216 * 1217 * The Responder must discard the Query without further processing 1218 * unless it is one of the Responder's unicast or anycast addresses, or 1219 * a link-local scope multicast address which the Responder has joined. 1220 * [RFC4602, Section 5.] 1221 */ 1222 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 1223 if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst)) 1224 goto bad; 1225 /* else it's a link-local multicast, fine */ 1226 } else { /* unicast or anycast */ 1227 ia6 = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */); 1228 if (ia6 == NULL) 1229 goto bad; /* XXX impossible */ 1230 1231 if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) && 1232 !(V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK)) { 1233 ifa_free(&ia6->ia_ifa); 1234 nd6log((LOG_DEBUG, "ni6_input: ignore node info to " 1235 "a temporary address in %s:%d", 1236 __FILE__, __LINE__)); 1237 goto bad; 1238 } 1239 ifa_free(&ia6->ia_ifa); 1240 } 1241 1242 /* validate query Subject field. */ 1243 qtype = ntohs(ni6->ni_qtype); 1244 subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo); 1245 switch (qtype) { 1246 case NI_QTYPE_NOOP: 1247 case NI_QTYPE_SUPTYPES: 1248 /* 07 draft */ 1249 if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0) 1250 break; 1251 /* FALLTHROUGH */ 1252 case NI_QTYPE_FQDN: 1253 case NI_QTYPE_NODEADDR: 1254 case NI_QTYPE_IPV4ADDR: 1255 switch (ni6->ni_code) { 1256 case ICMP6_NI_SUBJ_IPV6: 1257 #if ICMP6_NI_SUBJ_IPV6 != 0 1258 case 0: 1259 #endif 1260 /* 1261 * backward compatibility - try to accept 03 draft 1262 * format, where no Subject is present. 1263 */ 1264 if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 && 1265 subjlen == 0) { 1266 oldfqdn++; 1267 break; 1268 } 1269 #if ICMP6_NI_SUBJ_IPV6 != 0 1270 if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6) 1271 goto bad; 1272 #endif 1273 1274 if (subjlen != sizeof(struct in6_addr)) 1275 goto bad; 1276 1277 /* 1278 * Validate Subject address. 1279 * 1280 * Not sure what exactly "address belongs to the node" 1281 * means in the spec, is it just unicast, or what? 1282 * 1283 * At this moment we consider Subject address as 1284 * "belong to the node" if the Subject address equals 1285 * to the IPv6 destination address; validation for 1286 * IPv6 destination address should have done enough 1287 * check for us. 1288 * 1289 * We do not do proxy at this moment. 1290 */ 1291 /* m_pulldown instead of copy? */ 1292 m_copydata(m, off + sizeof(struct icmp6_nodeinfo), 1293 subjlen, (caddr_t)&in6_subj); 1294 if (in6_setscope(&in6_subj, m->m_pkthdr.rcvif, NULL)) 1295 goto bad; 1296 1297 subj = (char *)&in6_subj; 1298 if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &in6_subj)) 1299 break; 1300 1301 /* 1302 * XXX if we are to allow other cases, we should really 1303 * be careful about scope here. 1304 * basically, we should disallow queries toward IPv6 1305 * destination X with subject Y, 1306 * if scope(X) > scope(Y). 1307 * if we allow scope(X) > scope(Y), it will result in 1308 * information leakage across scope boundary. 1309 */ 1310 goto bad; 1311 1312 case ICMP6_NI_SUBJ_FQDN: 1313 /* 1314 * Validate Subject name with gethostname(3). 1315 * 1316 * The behavior may need some debate, since: 1317 * - we are not sure if the node has FQDN as 1318 * hostname (returned by gethostname(3)). 1319 * - the code does wildcard match for truncated names. 1320 * however, we are not sure if we want to perform 1321 * wildcard match, if gethostname(3) side has 1322 * truncated hostname. 1323 */ 1324 pr = curthread->td_ucred->cr_prison; 1325 mtx_lock(&pr->pr_mtx); 1326 n = ni6_nametodns(pr->pr_hostname, 1327 strlen(pr->pr_hostname), 0); 1328 mtx_unlock(&pr->pr_mtx); 1329 if (!n || n->m_next || n->m_len == 0) 1330 goto bad; 1331 IP6_EXTHDR_GET(subj, char *, m, 1332 off + sizeof(struct icmp6_nodeinfo), subjlen); 1333 if (subj == NULL) 1334 goto bad; 1335 if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *), 1336 n->m_len)) { 1337 goto bad; 1338 } 1339 m_freem(n); 1340 n = NULL; 1341 break; 1342 1343 case ICMP6_NI_SUBJ_IPV4: /* XXX: to be implemented? */ 1344 default: 1345 goto bad; 1346 } 1347 break; 1348 } 1349 1350 /* refuse based on configuration. XXX ICMP6_NI_REFUSED? */ 1351 switch (qtype) { 1352 case NI_QTYPE_FQDN: 1353 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_FQDNOK) == 0) 1354 goto bad; 1355 break; 1356 case NI_QTYPE_NODEADDR: 1357 case NI_QTYPE_IPV4ADDR: 1358 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_NODEADDROK) == 0) 1359 goto bad; 1360 break; 1361 } 1362 1363 /* guess reply length */ 1364 switch (qtype) { 1365 case NI_QTYPE_NOOP: 1366 break; /* no reply data */ 1367 case NI_QTYPE_SUPTYPES: 1368 replylen += sizeof(u_int32_t); 1369 break; 1370 case NI_QTYPE_FQDN: 1371 /* XXX will append an mbuf */ 1372 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); 1373 break; 1374 case NI_QTYPE_NODEADDR: 1375 addrs = ni6_addrs(ni6, m, &ifp, (struct in6_addr *)subj); 1376 if ((replylen += addrs * (sizeof(struct in6_addr) + 1377 sizeof(u_int32_t))) > MCLBYTES) 1378 replylen = MCLBYTES; /* XXX: will truncate pkt later */ 1379 break; 1380 case NI_QTYPE_IPV4ADDR: 1381 /* unsupported - should respond with unknown Qtype? */ 1382 break; 1383 default: 1384 /* 1385 * XXX: We must return a reply with the ICMP6 code 1386 * `unknown Qtype' in this case. However we regard the case 1387 * as an FQDN query for backward compatibility. 1388 * Older versions set a random value to this field, 1389 * so it rarely varies in the defined qtypes. 1390 * But the mechanism is not reliable... 1391 * maybe we should obsolete older versions. 1392 */ 1393 qtype = NI_QTYPE_FQDN; 1394 /* XXX will append an mbuf */ 1395 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); 1396 oldfqdn++; 1397 break; 1398 } 1399 1400 /* Allocate an mbuf to reply. */ 1401 if (replylen > MCLBYTES) { 1402 /* 1403 * XXX: should we try to allocate more? But MCLBYTES 1404 * is probably much larger than IPV6_MMTU... 1405 */ 1406 goto bad; 1407 } 1408 if (replylen > MHLEN) 1409 n = m_getcl(M_NOWAIT, m->m_type, M_PKTHDR); 1410 else 1411 n = m_gethdr(M_NOWAIT, m->m_type); 1412 if (n == NULL) { 1413 m_freem(m); 1414 return (NULL); 1415 } 1416 m_move_pkthdr(n, m); /* just for recvif and FIB */ 1417 n->m_pkthdr.len = n->m_len = replylen; 1418 1419 /* copy mbuf header and IPv6 + Node Information base headers */ 1420 bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr)); 1421 nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1); 1422 bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo)); 1423 1424 /* qtype dependent procedure */ 1425 switch (qtype) { 1426 case NI_QTYPE_NOOP: 1427 nni6->ni_code = ICMP6_NI_SUCCESS; 1428 nni6->ni_flags = 0; 1429 break; 1430 case NI_QTYPE_SUPTYPES: 1431 { 1432 u_int32_t v; 1433 nni6->ni_code = ICMP6_NI_SUCCESS; 1434 nni6->ni_flags = htons(0x0000); /* raw bitmap */ 1435 /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */ 1436 v = (u_int32_t)htonl(0x0000000f); 1437 bcopy(&v, nni6 + 1, sizeof(u_int32_t)); 1438 break; 1439 } 1440 case NI_QTYPE_FQDN: 1441 nni6->ni_code = ICMP6_NI_SUCCESS; 1442 fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) + 1443 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo)); 1444 nni6->ni_flags = 0; /* XXX: meaningless TTL */ 1445 fqdn->ni_fqdn_ttl = 0; /* ditto. */ 1446 /* 1447 * XXX do we really have FQDN in hostname? 1448 */ 1449 pr = curthread->td_ucred->cr_prison; 1450 mtx_lock(&pr->pr_mtx); 1451 n->m_next = ni6_nametodns(pr->pr_hostname, 1452 strlen(pr->pr_hostname), oldfqdn); 1453 mtx_unlock(&pr->pr_mtx); 1454 if (n->m_next == NULL) 1455 goto bad; 1456 /* XXX we assume that n->m_next is not a chain */ 1457 if (n->m_next->m_next != NULL) 1458 goto bad; 1459 n->m_pkthdr.len += n->m_next->m_len; 1460 break; 1461 case NI_QTYPE_NODEADDR: 1462 { 1463 int lenlim, copied; 1464 1465 nni6->ni_code = ICMP6_NI_SUCCESS; 1466 n->m_pkthdr.len = n->m_len = 1467 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); 1468 lenlim = M_TRAILINGSPACE(n); 1469 copied = ni6_store_addrs(ni6, nni6, ifp, lenlim); 1470 /* XXX: reset mbuf length */ 1471 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + 1472 sizeof(struct icmp6_nodeinfo) + copied; 1473 break; 1474 } 1475 default: 1476 break; /* XXX impossible! */ 1477 } 1478 1479 nni6->ni_type = ICMP6_NI_REPLY; 1480 m_freem(m); 1481 return (n); 1482 1483 bad: 1484 m_freem(m); 1485 if (n) 1486 m_freem(n); 1487 return (NULL); 1488 } 1489 1490 /* 1491 * make a mbuf with DNS-encoded string. no compression support. 1492 * 1493 * XXX names with less than 2 dots (like "foo" or "foo.section") will be 1494 * treated as truncated name (two \0 at the end). this is a wild guess. 1495 * 1496 * old - return pascal string if non-zero 1497 */ 1498 static struct mbuf * 1499 ni6_nametodns(const char *name, int namelen, int old) 1500 { 1501 struct mbuf *m; 1502 char *cp, *ep; 1503 const char *p, *q; 1504 int i, len, nterm; 1505 1506 if (old) 1507 len = namelen + 1; 1508 else 1509 len = MCLBYTES; 1510 1511 /* Because MAXHOSTNAMELEN is usually 256, we use cluster mbuf. */ 1512 if (len > MLEN) 1513 m = m_getcl(M_NOWAIT, MT_DATA, 0); 1514 else 1515 m = m_get(M_NOWAIT, MT_DATA); 1516 if (m == NULL) 1517 goto fail; 1518 1519 if (old) { 1520 m->m_len = len; 1521 *mtod(m, char *) = namelen; 1522 bcopy(name, mtod(m, char *) + 1, namelen); 1523 return m; 1524 } else { 1525 m->m_len = 0; 1526 cp = mtod(m, char *); 1527 ep = mtod(m, char *) + M_TRAILINGSPACE(m); 1528 1529 /* if not certain about my name, return empty buffer */ 1530 if (namelen == 0) 1531 return m; 1532 1533 /* 1534 * guess if it looks like shortened hostname, or FQDN. 1535 * shortened hostname needs two trailing "\0". 1536 */ 1537 i = 0; 1538 for (p = name; p < name + namelen; p++) { 1539 if (*p && *p == '.') 1540 i++; 1541 } 1542 if (i < 2) 1543 nterm = 2; 1544 else 1545 nterm = 1; 1546 1547 p = name; 1548 while (cp < ep && p < name + namelen) { 1549 i = 0; 1550 for (q = p; q < name + namelen && *q && *q != '.'; q++) 1551 i++; 1552 /* result does not fit into mbuf */ 1553 if (cp + i + 1 >= ep) 1554 goto fail; 1555 /* 1556 * DNS label length restriction, RFC1035 page 8. 1557 * "i == 0" case is included here to avoid returning 1558 * 0-length label on "foo..bar". 1559 */ 1560 if (i <= 0 || i >= 64) 1561 goto fail; 1562 *cp++ = i; 1563 bcopy(p, cp, i); 1564 cp += i; 1565 p = q; 1566 if (p < name + namelen && *p == '.') 1567 p++; 1568 } 1569 /* termination */ 1570 if (cp + nterm >= ep) 1571 goto fail; 1572 while (nterm-- > 0) 1573 *cp++ = '\0'; 1574 m->m_len = cp - mtod(m, char *); 1575 return m; 1576 } 1577 1578 panic("should not reach here"); 1579 /* NOTREACHED */ 1580 1581 fail: 1582 if (m) 1583 m_freem(m); 1584 return NULL; 1585 } 1586 1587 /* 1588 * check if two DNS-encoded string matches. takes care of truncated 1589 * form (with \0\0 at the end). no compression support. 1590 * XXX upper/lowercase match (see RFC2065) 1591 */ 1592 static int 1593 ni6_dnsmatch(const char *a, int alen, const char *b, int blen) 1594 { 1595 const char *a0, *b0; 1596 int l; 1597 1598 /* simplest case - need validation? */ 1599 if (alen == blen && bcmp(a, b, alen) == 0) 1600 return 1; 1601 1602 a0 = a; 1603 b0 = b; 1604 1605 /* termination is mandatory */ 1606 if (alen < 2 || blen < 2) 1607 return 0; 1608 if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0') 1609 return 0; 1610 alen--; 1611 blen--; 1612 1613 while (a - a0 < alen && b - b0 < blen) { 1614 if (a - a0 + 1 > alen || b - b0 + 1 > blen) 1615 return 0; 1616 1617 if ((signed char)a[0] < 0 || (signed char)b[0] < 0) 1618 return 0; 1619 /* we don't support compression yet */ 1620 if (a[0] >= 64 || b[0] >= 64) 1621 return 0; 1622 1623 /* truncated case */ 1624 if (a[0] == 0 && a - a0 == alen - 1) 1625 return 1; 1626 if (b[0] == 0 && b - b0 == blen - 1) 1627 return 1; 1628 if (a[0] == 0 || b[0] == 0) 1629 return 0; 1630 1631 if (a[0] != b[0]) 1632 return 0; 1633 l = a[0]; 1634 if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen) 1635 return 0; 1636 if (bcmp(a + 1, b + 1, l) != 0) 1637 return 0; 1638 1639 a += 1 + l; 1640 b += 1 + l; 1641 } 1642 1643 if (a - a0 == alen && b - b0 == blen) 1644 return 1; 1645 else 1646 return 0; 1647 } 1648 1649 /* 1650 * calculate the number of addresses to be returned in the node info reply. 1651 */ 1652 static int 1653 ni6_addrs(struct icmp6_nodeinfo *ni6, struct mbuf *m, struct ifnet **ifpp, 1654 struct in6_addr *subj) 1655 { 1656 struct ifnet *ifp; 1657 struct in6_ifaddr *ifa6; 1658 struct ifaddr *ifa; 1659 int addrs = 0, addrsofif, iffound = 0; 1660 int niflags = ni6->ni_flags; 1661 1662 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) { 1663 switch (ni6->ni_code) { 1664 case ICMP6_NI_SUBJ_IPV6: 1665 if (subj == NULL) /* must be impossible... */ 1666 return (0); 1667 break; 1668 default: 1669 /* 1670 * XXX: we only support IPv6 subject address for 1671 * this Qtype. 1672 */ 1673 return (0); 1674 } 1675 } 1676 1677 IFNET_RLOCK_NOSLEEP(); 1678 TAILQ_FOREACH(ifp, &V_ifnet, if_link) { 1679 addrsofif = 0; 1680 IF_ADDR_RLOCK(ifp); 1681 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 1682 if (ifa->ifa_addr->sa_family != AF_INET6) 1683 continue; 1684 ifa6 = (struct in6_ifaddr *)ifa; 1685 1686 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 && 1687 IN6_ARE_ADDR_EQUAL(subj, &ifa6->ia_addr.sin6_addr)) 1688 iffound = 1; 1689 1690 /* 1691 * IPv4-mapped addresses can only be returned by a 1692 * Node Information proxy, since they represent 1693 * addresses of IPv4-only nodes, which perforce do 1694 * not implement this protocol. 1695 * [icmp-name-lookups-07, Section 5.4] 1696 * So we don't support NI_NODEADDR_FLAG_COMPAT in 1697 * this function at this moment. 1698 */ 1699 1700 /* What do we have to do about ::1? */ 1701 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { 1702 case IPV6_ADDR_SCOPE_LINKLOCAL: 1703 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) 1704 continue; 1705 break; 1706 case IPV6_ADDR_SCOPE_SITELOCAL: 1707 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) 1708 continue; 1709 break; 1710 case IPV6_ADDR_SCOPE_GLOBAL: 1711 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) 1712 continue; 1713 break; 1714 default: 1715 continue; 1716 } 1717 1718 /* 1719 * check if anycast is okay. 1720 * XXX: just experimental. not in the spec. 1721 */ 1722 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && 1723 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) 1724 continue; /* we need only unicast addresses */ 1725 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && 1726 (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) { 1727 continue; 1728 } 1729 addrsofif++; /* count the address */ 1730 } 1731 IF_ADDR_RUNLOCK(ifp); 1732 if (iffound) { 1733 *ifpp = ifp; 1734 IFNET_RUNLOCK_NOSLEEP(); 1735 return (addrsofif); 1736 } 1737 1738 addrs += addrsofif; 1739 } 1740 IFNET_RUNLOCK_NOSLEEP(); 1741 1742 return (addrs); 1743 } 1744 1745 static int 1746 ni6_store_addrs(struct icmp6_nodeinfo *ni6, struct icmp6_nodeinfo *nni6, 1747 struct ifnet *ifp0, int resid) 1748 { 1749 struct ifnet *ifp; 1750 struct in6_ifaddr *ifa6; 1751 struct ifaddr *ifa; 1752 struct ifnet *ifp_dep = NULL; 1753 int copied = 0, allow_deprecated = 0; 1754 u_char *cp = (u_char *)(nni6 + 1); 1755 int niflags = ni6->ni_flags; 1756 u_int32_t ltime; 1757 1758 if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL)) 1759 return (0); /* needless to copy */ 1760 1761 IFNET_RLOCK_NOSLEEP(); 1762 ifp = ifp0 ? ifp0 : TAILQ_FIRST(&V_ifnet); 1763 again: 1764 1765 for (; ifp; ifp = TAILQ_NEXT(ifp, if_link)) { 1766 IF_ADDR_RLOCK(ifp); 1767 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 1768 if (ifa->ifa_addr->sa_family != AF_INET6) 1769 continue; 1770 ifa6 = (struct in6_ifaddr *)ifa; 1771 1772 if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 && 1773 allow_deprecated == 0) { 1774 /* 1775 * prefererred address should be put before 1776 * deprecated addresses. 1777 */ 1778 1779 /* record the interface for later search */ 1780 if (ifp_dep == NULL) 1781 ifp_dep = ifp; 1782 1783 continue; 1784 } else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 && 1785 allow_deprecated != 0) 1786 continue; /* we now collect deprecated addrs */ 1787 1788 /* What do we have to do about ::1? */ 1789 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { 1790 case IPV6_ADDR_SCOPE_LINKLOCAL: 1791 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) 1792 continue; 1793 break; 1794 case IPV6_ADDR_SCOPE_SITELOCAL: 1795 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) 1796 continue; 1797 break; 1798 case IPV6_ADDR_SCOPE_GLOBAL: 1799 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) 1800 continue; 1801 break; 1802 default: 1803 continue; 1804 } 1805 1806 /* 1807 * check if anycast is okay. 1808 * XXX: just experimental. not in the spec. 1809 */ 1810 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && 1811 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) 1812 continue; 1813 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && 1814 (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) { 1815 continue; 1816 } 1817 1818 /* now we can copy the address */ 1819 if (resid < sizeof(struct in6_addr) + 1820 sizeof(u_int32_t)) { 1821 IF_ADDR_RUNLOCK(ifp); 1822 /* 1823 * We give up much more copy. 1824 * Set the truncate flag and return. 1825 */ 1826 nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE; 1827 IFNET_RUNLOCK_NOSLEEP(); 1828 return (copied); 1829 } 1830 1831 /* 1832 * Set the TTL of the address. 1833 * The TTL value should be one of the following 1834 * according to the specification: 1835 * 1836 * 1. The remaining lifetime of a DHCP lease on the 1837 * address, or 1838 * 2. The remaining Valid Lifetime of a prefix from 1839 * which the address was derived through Stateless 1840 * Autoconfiguration. 1841 * 1842 * Note that we currently do not support stateful 1843 * address configuration by DHCPv6, so the former 1844 * case can't happen. 1845 */ 1846 if (ifa6->ia6_lifetime.ia6t_expire == 0) 1847 ltime = ND6_INFINITE_LIFETIME; 1848 else { 1849 if (ifa6->ia6_lifetime.ia6t_expire > 1850 time_uptime) 1851 ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_uptime); 1852 else 1853 ltime = 0; 1854 } 1855 1856 bcopy(<ime, cp, sizeof(u_int32_t)); 1857 cp += sizeof(u_int32_t); 1858 1859 /* copy the address itself */ 1860 bcopy(&ifa6->ia_addr.sin6_addr, cp, 1861 sizeof(struct in6_addr)); 1862 in6_clearscope((struct in6_addr *)cp); /* XXX */ 1863 cp += sizeof(struct in6_addr); 1864 1865 resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t)); 1866 copied += (sizeof(struct in6_addr) + sizeof(u_int32_t)); 1867 } 1868 IF_ADDR_RUNLOCK(ifp); 1869 if (ifp0) /* we need search only on the specified IF */ 1870 break; 1871 } 1872 1873 if (allow_deprecated == 0 && ifp_dep != NULL) { 1874 ifp = ifp_dep; 1875 allow_deprecated = 1; 1876 1877 goto again; 1878 } 1879 1880 IFNET_RUNLOCK_NOSLEEP(); 1881 1882 return (copied); 1883 } 1884 1885 /* 1886 * XXX almost dup'ed code with rip6_input. 1887 */ 1888 static int 1889 icmp6_rip6_input(struct mbuf **mp, int off) 1890 { 1891 struct mbuf *m = *mp; 1892 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1893 struct inpcb *in6p; 1894 struct inpcb *last = NULL; 1895 struct sockaddr_in6 fromsa; 1896 struct icmp6_hdr *icmp6; 1897 struct mbuf *opts = NULL; 1898 1899 #ifndef PULLDOWN_TEST 1900 /* this is assumed to be safe. */ 1901 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off); 1902 #else 1903 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6)); 1904 if (icmp6 == NULL) { 1905 /* m is already reclaimed */ 1906 return (IPPROTO_DONE); 1907 } 1908 #endif 1909 1910 /* 1911 * XXX: the address may have embedded scope zone ID, which should be 1912 * hidden from applications. 1913 */ 1914 bzero(&fromsa, sizeof(fromsa)); 1915 fromsa.sin6_family = AF_INET6; 1916 fromsa.sin6_len = sizeof(struct sockaddr_in6); 1917 fromsa.sin6_addr = ip6->ip6_src; 1918 if (sa6_recoverscope(&fromsa)) { 1919 m_freem(m); 1920 return (IPPROTO_DONE); 1921 } 1922 1923 INP_INFO_RLOCK(&V_ripcbinfo); 1924 LIST_FOREACH(in6p, &V_ripcb, inp_list) { 1925 if ((in6p->inp_vflag & INP_IPV6) == 0) 1926 continue; 1927 if (in6p->inp_ip_p != IPPROTO_ICMPV6) 1928 continue; 1929 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) && 1930 !IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &ip6->ip6_dst)) 1931 continue; 1932 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr) && 1933 !IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src)) 1934 continue; 1935 INP_RLOCK(in6p); 1936 if (ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type, 1937 in6p->in6p_icmp6filt)) { 1938 INP_RUNLOCK(in6p); 1939 continue; 1940 } 1941 if (last != NULL) { 1942 struct mbuf *n = NULL; 1943 1944 /* 1945 * Recent network drivers tend to allocate a single 1946 * mbuf cluster, rather than to make a couple of 1947 * mbufs without clusters. Also, since the IPv6 code 1948 * path tries to avoid m_pullup(), it is highly 1949 * probable that we still have an mbuf cluster here 1950 * even though the necessary length can be stored in an 1951 * mbuf's internal buffer. 1952 * Meanwhile, the default size of the receive socket 1953 * buffer for raw sockets is not so large. This means 1954 * the possibility of packet loss is relatively higher 1955 * than before. To avoid this scenario, we copy the 1956 * received data to a separate mbuf that does not use 1957 * a cluster, if possible. 1958 * XXX: it is better to copy the data after stripping 1959 * intermediate headers. 1960 */ 1961 if ((m->m_flags & M_EXT) && m->m_next == NULL && 1962 m->m_len <= MHLEN) { 1963 n = m_get(M_NOWAIT, m->m_type); 1964 if (n != NULL) { 1965 if (m_dup_pkthdr(n, m, M_NOWAIT)) { 1966 bcopy(m->m_data, n->m_data, 1967 m->m_len); 1968 n->m_len = m->m_len; 1969 } else { 1970 m_free(n); 1971 n = NULL; 1972 } 1973 } 1974 } 1975 if (n != NULL || 1976 (n = m_copy(m, 0, (int)M_COPYALL)) != NULL) { 1977 if (last->inp_flags & INP_CONTROLOPTS) 1978 ip6_savecontrol(last, n, &opts); 1979 /* strip intermediate headers */ 1980 m_adj(n, off); 1981 SOCKBUF_LOCK(&last->inp_socket->so_rcv); 1982 if (sbappendaddr_locked( 1983 &last->inp_socket->so_rcv, 1984 (struct sockaddr *)&fromsa, n, opts) 1985 == 0) { 1986 /* should notify about lost packet */ 1987 m_freem(n); 1988 if (opts) { 1989 m_freem(opts); 1990 } 1991 SOCKBUF_UNLOCK( 1992 &last->inp_socket->so_rcv); 1993 } else 1994 sorwakeup_locked(last->inp_socket); 1995 opts = NULL; 1996 } 1997 INP_RUNLOCK(last); 1998 } 1999 last = in6p; 2000 } 2001 INP_INFO_RUNLOCK(&V_ripcbinfo); 2002 if (last != NULL) { 2003 if (last->inp_flags & INP_CONTROLOPTS) 2004 ip6_savecontrol(last, m, &opts); 2005 /* strip intermediate headers */ 2006 m_adj(m, off); 2007 2008 /* avoid using mbuf clusters if possible (see above) */ 2009 if ((m->m_flags & M_EXT) && m->m_next == NULL && 2010 m->m_len <= MHLEN) { 2011 struct mbuf *n; 2012 2013 n = m_get(M_NOWAIT, m->m_type); 2014 if (n != NULL) { 2015 if (m_dup_pkthdr(n, m, M_NOWAIT)) { 2016 bcopy(m->m_data, n->m_data, m->m_len); 2017 n->m_len = m->m_len; 2018 2019 m_freem(m); 2020 m = n; 2021 } else { 2022 m_freem(n); 2023 n = NULL; 2024 } 2025 } 2026 } 2027 SOCKBUF_LOCK(&last->inp_socket->so_rcv); 2028 if (sbappendaddr_locked(&last->inp_socket->so_rcv, 2029 (struct sockaddr *)&fromsa, m, opts) == 0) { 2030 m_freem(m); 2031 if (opts) 2032 m_freem(opts); 2033 SOCKBUF_UNLOCK(&last->inp_socket->so_rcv); 2034 } else 2035 sorwakeup_locked(last->inp_socket); 2036 INP_RUNLOCK(last); 2037 } else { 2038 m_freem(m); 2039 IP6STAT_DEC(ip6s_delivered); 2040 } 2041 return IPPROTO_DONE; 2042 } 2043 2044 /* 2045 * Reflect the ip6 packet back to the source. 2046 * OFF points to the icmp6 header, counted from the top of the mbuf. 2047 */ 2048 void 2049 icmp6_reflect(struct mbuf *m, size_t off) 2050 { 2051 struct in6_addr src6, *srcp; 2052 struct ip6_hdr *ip6; 2053 struct icmp6_hdr *icmp6; 2054 struct in6_ifaddr *ia = NULL; 2055 struct ifnet *outif = NULL; 2056 int plen; 2057 int type, code, hlim; 2058 2059 /* too short to reflect */ 2060 if (off < sizeof(struct ip6_hdr)) { 2061 nd6log((LOG_DEBUG, 2062 "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n", 2063 (u_long)off, (u_long)sizeof(struct ip6_hdr), 2064 __FILE__, __LINE__)); 2065 goto bad; 2066 } 2067 2068 /* 2069 * If there are extra headers between IPv6 and ICMPv6, strip 2070 * off that header first. 2071 */ 2072 #ifdef DIAGNOSTIC 2073 if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN) 2074 panic("assumption failed in icmp6_reflect"); 2075 #endif 2076 if (off > sizeof(struct ip6_hdr)) { 2077 size_t l; 2078 struct ip6_hdr nip6; 2079 2080 l = off - sizeof(struct ip6_hdr); 2081 m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6); 2082 m_adj(m, l); 2083 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 2084 if (m->m_len < l) { 2085 if ((m = m_pullup(m, l)) == NULL) 2086 return; 2087 } 2088 bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6)); 2089 } else /* off == sizeof(struct ip6_hdr) */ { 2090 size_t l; 2091 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 2092 if (m->m_len < l) { 2093 if ((m = m_pullup(m, l)) == NULL) 2094 return; 2095 } 2096 } 2097 plen = m->m_pkthdr.len - sizeof(struct ip6_hdr); 2098 ip6 = mtod(m, struct ip6_hdr *); 2099 ip6->ip6_nxt = IPPROTO_ICMPV6; 2100 icmp6 = (struct icmp6_hdr *)(ip6 + 1); 2101 type = icmp6->icmp6_type; /* keep type for statistics */ 2102 code = icmp6->icmp6_code; /* ditto. */ 2103 hlim = 0; 2104 srcp = NULL; 2105 2106 /* 2107 * If the incoming packet was addressed directly to us (i.e. unicast), 2108 * use dst as the src for the reply. 2109 * The IN6_IFF_NOTREADY case should be VERY rare, but is possible 2110 * (for example) when we encounter an error while forwarding procedure 2111 * destined to a duplicated address of ours. 2112 */ 2113 if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 2114 ia = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */); 2115 if (ia != NULL && !(ia->ia6_flags & 2116 (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) { 2117 src6 = ia->ia_addr.sin6_addr; 2118 srcp = &src6; 2119 2120 if (m->m_pkthdr.rcvif != NULL) { 2121 /* XXX: This may not be the outgoing interface */ 2122 hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim; 2123 } else 2124 hlim = V_ip6_defhlim; 2125 } 2126 if (ia != NULL) 2127 ifa_free(&ia->ia_ifa); 2128 } 2129 2130 if (srcp == NULL) { 2131 int error; 2132 struct in6_addr dst6; 2133 uint32_t scopeid; 2134 2135 /* 2136 * This case matches to multicasts, our anycast, or unicasts 2137 * that we do not own. Select a source address based on the 2138 * source address of the erroneous packet. 2139 */ 2140 in6_splitscope(&ip6->ip6_src, &dst6, &scopeid); 2141 error = in6_selectsrc_addr(M_GETFIB(m), &dst6, 2142 scopeid, NULL, &src6, &hlim); 2143 2144 if (error) { 2145 char ip6buf[INET6_ADDRSTRLEN]; 2146 nd6log((LOG_DEBUG, 2147 "icmp6_reflect: source can't be determined: " 2148 "dst=%s, error=%d\n", 2149 ip6_sprintf(ip6buf, &ip6->ip6_dst), error)); 2150 goto bad; 2151 } 2152 srcp = &src6; 2153 } 2154 /* 2155 * ip6_input() drops a packet if its src is multicast. 2156 * So, the src is never multicast. 2157 */ 2158 ip6->ip6_dst = ip6->ip6_src; 2159 ip6->ip6_src = *srcp; 2160 ip6->ip6_flow = 0; 2161 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2162 ip6->ip6_vfc |= IPV6_VERSION; 2163 ip6->ip6_nxt = IPPROTO_ICMPV6; 2164 ip6->ip6_hlim = hlim; 2165 2166 icmp6->icmp6_cksum = 0; 2167 icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2168 sizeof(struct ip6_hdr), plen); 2169 2170 /* 2171 * XXX option handling 2172 */ 2173 2174 m->m_flags &= ~(M_BCAST|M_MCAST); 2175 m->m_pkthdr.rcvif = NULL; 2176 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2177 if (outif) 2178 icmp6_ifoutstat_inc(outif, type, code); 2179 2180 return; 2181 2182 bad: 2183 m_freem(m); 2184 return; 2185 } 2186 2187 void 2188 icmp6_fasttimo(void) 2189 { 2190 2191 mld_fasttimo(); 2192 } 2193 2194 void 2195 icmp6_slowtimo(void) 2196 { 2197 2198 mld_slowtimo(); 2199 } 2200 2201 static const char * 2202 icmp6_redirect_diag(struct in6_addr *src6, struct in6_addr *dst6, 2203 struct in6_addr *tgt6) 2204 { 2205 static char buf[1024]; 2206 char ip6bufs[INET6_ADDRSTRLEN]; 2207 char ip6bufd[INET6_ADDRSTRLEN]; 2208 char ip6buft[INET6_ADDRSTRLEN]; 2209 snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)", 2210 ip6_sprintf(ip6bufs, src6), ip6_sprintf(ip6bufd, dst6), 2211 ip6_sprintf(ip6buft, tgt6)); 2212 return buf; 2213 } 2214 2215 void 2216 icmp6_redirect_input(struct mbuf *m, int off) 2217 { 2218 struct ifnet *ifp; 2219 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 2220 struct nd_redirect *nd_rd; 2221 int icmp6len = ntohs(ip6->ip6_plen); 2222 char *lladdr = NULL; 2223 int lladdrlen = 0; 2224 int is_router; 2225 int is_onlink; 2226 struct in6_addr src6 = ip6->ip6_src; 2227 struct in6_addr redtgt6; 2228 struct in6_addr reddst6; 2229 union nd_opts ndopts; 2230 char ip6buf[INET6_ADDRSTRLEN]; 2231 2232 M_ASSERTPKTHDR(m); 2233 KASSERT(m->m_pkthdr.rcvif != NULL, ("%s: no rcvif", __func__)); 2234 2235 ifp = m->m_pkthdr.rcvif; 2236 2237 /* XXX if we are router, we don't update route by icmp6 redirect */ 2238 if (V_ip6_forwarding) 2239 goto freeit; 2240 if (!V_icmp6_rediraccept) 2241 goto freeit; 2242 2243 /* RFC 6980: Nodes MUST silently ignore fragments */ 2244 if(m->m_flags & M_FRAGMENTED) 2245 goto freeit; 2246 2247 #ifndef PULLDOWN_TEST 2248 IP6_EXTHDR_CHECK(m, off, icmp6len,); 2249 nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off); 2250 #else 2251 IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len); 2252 if (nd_rd == NULL) { 2253 ICMP6STAT_INC(icp6s_tooshort); 2254 return; 2255 } 2256 #endif 2257 redtgt6 = nd_rd->nd_rd_target; 2258 reddst6 = nd_rd->nd_rd_dst; 2259 2260 if (in6_setscope(&redtgt6, m->m_pkthdr.rcvif, NULL) || 2261 in6_setscope(&reddst6, m->m_pkthdr.rcvif, NULL)) { 2262 goto freeit; 2263 } 2264 2265 /* validation */ 2266 if (!IN6_IS_ADDR_LINKLOCAL(&src6)) { 2267 nd6log((LOG_ERR, 2268 "ICMP6 redirect sent from %s rejected; " 2269 "must be from linklocal\n", 2270 ip6_sprintf(ip6buf, &src6))); 2271 goto bad; 2272 } 2273 if (ip6->ip6_hlim != 255) { 2274 nd6log((LOG_ERR, 2275 "ICMP6 redirect sent from %s rejected; " 2276 "hlim=%d (must be 255)\n", 2277 ip6_sprintf(ip6buf, &src6), ip6->ip6_hlim)); 2278 goto bad; 2279 } 2280 { 2281 /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */ 2282 struct nhop6_basic nh6; 2283 struct in6_addr kdst; 2284 uint32_t scopeid; 2285 2286 in6_splitscope(&reddst6, &kdst, &scopeid); 2287 if (fib6_lookup_nh_basic(ifp->if_fib, &kdst, scopeid, 0, 0,&nh6)==0){ 2288 if ((nh6.nh_flags & NHF_GATEWAY) == 0) { 2289 nd6log((LOG_ERR, 2290 "ICMP6 redirect rejected; no route " 2291 "with inet6 gateway found for redirect dst: %s\n", 2292 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2293 goto bad; 2294 } 2295 2296 /* 2297 * Embed scope zone id into next hop address, since 2298 * fib6_lookup_nh_basic() returns address without embedded 2299 * scope zone id. 2300 */ 2301 if (in6_setscope(&nh6.nh_addr, m->m_pkthdr.rcvif, NULL)) 2302 goto freeit; 2303 2304 if (IN6_ARE_ADDR_EQUAL(&src6, &nh6.nh_addr) == 0) { 2305 nd6log((LOG_ERR, 2306 "ICMP6 redirect rejected; " 2307 "not equal to gw-for-src=%s (must be same): " 2308 "%s\n", 2309 ip6_sprintf(ip6buf, &nh6.nh_addr), 2310 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2311 goto bad; 2312 } 2313 } else { 2314 nd6log((LOG_ERR, 2315 "ICMP6 redirect rejected; " 2316 "no route found for redirect dst: %s\n", 2317 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2318 goto bad; 2319 } 2320 } 2321 if (IN6_IS_ADDR_MULTICAST(&reddst6)) { 2322 nd6log((LOG_ERR, 2323 "ICMP6 redirect rejected; " 2324 "redirect dst must be unicast: %s\n", 2325 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2326 goto bad; 2327 } 2328 2329 is_router = is_onlink = 0; 2330 if (IN6_IS_ADDR_LINKLOCAL(&redtgt6)) 2331 is_router = 1; /* router case */ 2332 if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0) 2333 is_onlink = 1; /* on-link destination case */ 2334 if (!is_router && !is_onlink) { 2335 nd6log((LOG_ERR, 2336 "ICMP6 redirect rejected; " 2337 "neither router case nor onlink case: %s\n", 2338 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2339 goto bad; 2340 } 2341 2342 icmp6len -= sizeof(*nd_rd); 2343 nd6_option_init(nd_rd + 1, icmp6len, &ndopts); 2344 if (nd6_options(&ndopts) < 0) { 2345 nd6log((LOG_INFO, "%s: invalid ND option, rejected: %s\n", 2346 __func__, icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2347 /* nd6_options have incremented stats */ 2348 goto freeit; 2349 } 2350 2351 if (ndopts.nd_opts_tgt_lladdr) { 2352 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 2353 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 2354 } 2355 2356 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 2357 nd6log((LOG_INFO, "%s: lladdrlen mismatch for %s " 2358 "(if %d, icmp6 packet %d): %s\n", 2359 __func__, ip6_sprintf(ip6buf, &redtgt6), 2360 ifp->if_addrlen, lladdrlen - 2, 2361 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2362 goto bad; 2363 } 2364 2365 /* Validation passed. */ 2366 2367 /* RFC 2461 8.3 */ 2368 nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT, 2369 is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER); 2370 2371 /* 2372 * Install a gateway route in the better-router case or an interface 2373 * route in the on-link-destination case. 2374 */ 2375 { 2376 struct sockaddr_in6 sdst; 2377 struct sockaddr_in6 sgw; 2378 struct sockaddr_in6 ssrc; 2379 struct sockaddr *gw; 2380 int rt_flags; 2381 u_int fibnum; 2382 2383 bzero(&sdst, sizeof(sdst)); 2384 bzero(&ssrc, sizeof(ssrc)); 2385 sdst.sin6_family = ssrc.sin6_family = AF_INET6; 2386 sdst.sin6_len = ssrc.sin6_len = sizeof(struct sockaddr_in6); 2387 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr)); 2388 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr)); 2389 rt_flags = RTF_HOST; 2390 if (is_router) { 2391 bzero(&sgw, sizeof(sgw)); 2392 sgw.sin6_family = AF_INET6; 2393 sgw.sin6_len = sizeof(struct sockaddr_in6); 2394 bcopy(&redtgt6, &sgw.sin6_addr, 2395 sizeof(struct in6_addr)); 2396 gw = (struct sockaddr *)&sgw; 2397 rt_flags |= RTF_GATEWAY; 2398 } else 2399 gw = ifp->if_addr->ifa_addr; 2400 for (fibnum = 0; fibnum < rt_numfibs; fibnum++) 2401 in6_rtredirect((struct sockaddr *)&sdst, gw, 2402 (struct sockaddr *)NULL, rt_flags, 2403 (struct sockaddr *)&ssrc, fibnum); 2404 } 2405 /* finally update cached route in each socket via pfctlinput */ 2406 { 2407 struct sockaddr_in6 sdst; 2408 2409 bzero(&sdst, sizeof(sdst)); 2410 sdst.sin6_family = AF_INET6; 2411 sdst.sin6_len = sizeof(struct sockaddr_in6); 2412 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr)); 2413 pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst); 2414 } 2415 2416 freeit: 2417 m_freem(m); 2418 return; 2419 2420 bad: 2421 ICMP6STAT_INC(icp6s_badredirect); 2422 m_freem(m); 2423 } 2424 2425 void 2426 icmp6_redirect_output(struct mbuf *m0, struct rtentry *rt) 2427 { 2428 struct ifnet *ifp; /* my outgoing interface */ 2429 struct in6_addr *ifp_ll6; 2430 struct in6_addr *router_ll6; 2431 struct ip6_hdr *sip6; /* m0 as struct ip6_hdr */ 2432 struct mbuf *m = NULL; /* newly allocated one */ 2433 struct m_tag *mtag; 2434 struct ip6_hdr *ip6; /* m as struct ip6_hdr */ 2435 struct nd_redirect *nd_rd; 2436 struct llentry *ln = NULL; 2437 size_t maxlen; 2438 u_char *p; 2439 struct ifnet *outif = NULL; 2440 struct sockaddr_in6 src_sa; 2441 2442 icmp6_errcount(ND_REDIRECT, 0); 2443 2444 /* if we are not router, we don't send icmp6 redirect */ 2445 if (!V_ip6_forwarding) 2446 goto fail; 2447 2448 /* sanity check */ 2449 if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp)) 2450 goto fail; 2451 2452 /* 2453 * Address check: 2454 * the source address must identify a neighbor, and 2455 * the destination address must not be a multicast address 2456 * [RFC 2461, sec 8.2] 2457 */ 2458 sip6 = mtod(m0, struct ip6_hdr *); 2459 bzero(&src_sa, sizeof(src_sa)); 2460 src_sa.sin6_family = AF_INET6; 2461 src_sa.sin6_len = sizeof(src_sa); 2462 src_sa.sin6_addr = sip6->ip6_src; 2463 if (nd6_is_addr_neighbor(&src_sa, ifp) == 0) 2464 goto fail; 2465 if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst)) 2466 goto fail; /* what should we do here? */ 2467 2468 /* rate limit */ 2469 if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0)) 2470 goto fail; 2471 2472 /* 2473 * Since we are going to append up to 1280 bytes (= IPV6_MMTU), 2474 * we almost always ask for an mbuf cluster for simplicity. 2475 * (MHLEN < IPV6_MMTU is almost always true) 2476 */ 2477 #if IPV6_MMTU >= MCLBYTES 2478 # error assumption failed about IPV6_MMTU and MCLBYTES 2479 #endif 2480 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 2481 if (m == NULL) 2482 goto fail; 2483 M_SETFIB(m, rt->rt_fibnum); 2484 maxlen = M_TRAILINGSPACE(m); 2485 maxlen = min(IPV6_MMTU, maxlen); 2486 /* just for safety */ 2487 if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) + 2488 ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) { 2489 goto fail; 2490 } 2491 2492 { 2493 /* get ip6 linklocal address for ifp(my outgoing interface). */ 2494 struct in6_ifaddr *ia; 2495 if ((ia = in6ifa_ifpforlinklocal(ifp, 2496 IN6_IFF_NOTREADY| 2497 IN6_IFF_ANYCAST)) == NULL) 2498 goto fail; 2499 ifp_ll6 = &ia->ia_addr.sin6_addr; 2500 /* XXXRW: reference released prematurely. */ 2501 ifa_free(&ia->ia_ifa); 2502 } 2503 2504 /* get ip6 linklocal address for the router. */ 2505 if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) { 2506 struct sockaddr_in6 *sin6; 2507 sin6 = (struct sockaddr_in6 *)rt->rt_gateway; 2508 router_ll6 = &sin6->sin6_addr; 2509 if (!IN6_IS_ADDR_LINKLOCAL(router_ll6)) 2510 router_ll6 = (struct in6_addr *)NULL; 2511 } else 2512 router_ll6 = (struct in6_addr *)NULL; 2513 2514 /* ip6 */ 2515 ip6 = mtod(m, struct ip6_hdr *); 2516 ip6->ip6_flow = 0; 2517 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2518 ip6->ip6_vfc |= IPV6_VERSION; 2519 /* ip6->ip6_plen will be set later */ 2520 ip6->ip6_nxt = IPPROTO_ICMPV6; 2521 ip6->ip6_hlim = 255; 2522 /* ip6->ip6_src must be linklocal addr for my outgoing if. */ 2523 bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr)); 2524 bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr)); 2525 2526 /* ND Redirect */ 2527 nd_rd = (struct nd_redirect *)(ip6 + 1); 2528 nd_rd->nd_rd_type = ND_REDIRECT; 2529 nd_rd->nd_rd_code = 0; 2530 nd_rd->nd_rd_reserved = 0; 2531 if (rt->rt_flags & RTF_GATEWAY) { 2532 /* 2533 * nd_rd->nd_rd_target must be a link-local address in 2534 * better router cases. 2535 */ 2536 if (!router_ll6) 2537 goto fail; 2538 bcopy(router_ll6, &nd_rd->nd_rd_target, 2539 sizeof(nd_rd->nd_rd_target)); 2540 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2541 sizeof(nd_rd->nd_rd_dst)); 2542 } else { 2543 /* make sure redtgt == reddst */ 2544 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target, 2545 sizeof(nd_rd->nd_rd_target)); 2546 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2547 sizeof(nd_rd->nd_rd_dst)); 2548 } 2549 2550 p = (u_char *)(nd_rd + 1); 2551 2552 if (!router_ll6) 2553 goto nolladdropt; 2554 2555 { 2556 /* target lladdr option */ 2557 int len; 2558 struct nd_opt_hdr *nd_opt; 2559 char *lladdr; 2560 2561 IF_AFDATA_RLOCK(ifp); 2562 ln = nd6_lookup(router_ll6, 0, ifp); 2563 IF_AFDATA_RUNLOCK(ifp); 2564 if (ln == NULL) 2565 goto nolladdropt; 2566 2567 len = sizeof(*nd_opt) + ifp->if_addrlen; 2568 len = (len + 7) & ~7; /* round by 8 */ 2569 /* safety check */ 2570 if (len + (p - (u_char *)ip6) > maxlen) 2571 goto nolladdropt; 2572 2573 if (ln->la_flags & LLE_VALID) { 2574 nd_opt = (struct nd_opt_hdr *)p; 2575 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 2576 nd_opt->nd_opt_len = len >> 3; 2577 lladdr = (char *)(nd_opt + 1); 2578 bcopy(ln->ll_addr, lladdr, ifp->if_addrlen); 2579 p += len; 2580 } 2581 } 2582 nolladdropt: 2583 if (ln != NULL) 2584 LLE_RUNLOCK(ln); 2585 2586 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2587 2588 /* just to be safe */ 2589 #ifdef M_DECRYPTED /*not openbsd*/ 2590 if (m0->m_flags & M_DECRYPTED) 2591 goto noredhdropt; 2592 #endif 2593 if (p - (u_char *)ip6 > maxlen) 2594 goto noredhdropt; 2595 2596 { 2597 /* redirected header option */ 2598 int len; 2599 struct nd_opt_rd_hdr *nd_opt_rh; 2600 2601 /* 2602 * compute the maximum size for icmp6 redirect header option. 2603 * XXX room for auth header? 2604 */ 2605 len = maxlen - (p - (u_char *)ip6); 2606 len &= ~7; 2607 2608 /* This is just for simplicity. */ 2609 if (m0->m_pkthdr.len != m0->m_len) { 2610 if (m0->m_next) { 2611 m_freem(m0->m_next); 2612 m0->m_next = NULL; 2613 } 2614 m0->m_pkthdr.len = m0->m_len; 2615 } 2616 2617 /* 2618 * Redirected header option spec (RFC2461 4.6.3) talks nothing 2619 * about padding/truncate rule for the original IP packet. 2620 * From the discussion on IPv6imp in Feb 1999, 2621 * the consensus was: 2622 * - "attach as much as possible" is the goal 2623 * - pad if not aligned (original size can be guessed by 2624 * original ip6 header) 2625 * Following code adds the padding if it is simple enough, 2626 * and truncates if not. 2627 */ 2628 if (m0->m_next || m0->m_pkthdr.len != m0->m_len) 2629 panic("assumption failed in %s:%d", __FILE__, 2630 __LINE__); 2631 2632 if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) { 2633 /* not enough room, truncate */ 2634 m0->m_pkthdr.len = m0->m_len = len - 2635 sizeof(*nd_opt_rh); 2636 } else { 2637 /* enough room, pad or truncate */ 2638 size_t extra; 2639 2640 extra = m0->m_pkthdr.len % 8; 2641 if (extra) { 2642 /* pad if easy enough, truncate if not */ 2643 if (8 - extra <= M_TRAILINGSPACE(m0)) { 2644 /* pad */ 2645 m0->m_len += (8 - extra); 2646 m0->m_pkthdr.len += (8 - extra); 2647 } else { 2648 /* truncate */ 2649 m0->m_pkthdr.len -= extra; 2650 m0->m_len -= extra; 2651 } 2652 } 2653 len = m0->m_pkthdr.len + sizeof(*nd_opt_rh); 2654 m0->m_pkthdr.len = m0->m_len = len - 2655 sizeof(*nd_opt_rh); 2656 } 2657 2658 nd_opt_rh = (struct nd_opt_rd_hdr *)p; 2659 bzero(nd_opt_rh, sizeof(*nd_opt_rh)); 2660 nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER; 2661 nd_opt_rh->nd_opt_rh_len = len >> 3; 2662 p += sizeof(*nd_opt_rh); 2663 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2664 2665 /* connect m0 to m */ 2666 m_tag_delete_chain(m0, NULL); 2667 m0->m_flags &= ~M_PKTHDR; 2668 m->m_next = m0; 2669 m->m_pkthdr.len = m->m_len + m0->m_len; 2670 m0 = NULL; 2671 } 2672 noredhdropt:; 2673 if (m0) { 2674 m_freem(m0); 2675 m0 = NULL; 2676 } 2677 2678 /* XXX: clear embedded link IDs in the inner header */ 2679 in6_clearscope(&sip6->ip6_src); 2680 in6_clearscope(&sip6->ip6_dst); 2681 in6_clearscope(&nd_rd->nd_rd_target); 2682 in6_clearscope(&nd_rd->nd_rd_dst); 2683 2684 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr)); 2685 2686 nd_rd->nd_rd_cksum = 0; 2687 nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2688 sizeof(*ip6), ntohs(ip6->ip6_plen)); 2689 2690 if (send_sendso_input_hook != NULL) { 2691 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, sizeof(unsigned short), 2692 M_NOWAIT); 2693 if (mtag == NULL) 2694 goto fail; 2695 *(unsigned short *)(mtag + 1) = nd_rd->nd_rd_type; 2696 m_tag_prepend(m, mtag); 2697 } 2698 2699 /* send the packet to outside... */ 2700 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2701 if (outif) { 2702 icmp6_ifstat_inc(outif, ifs6_out_msg); 2703 icmp6_ifstat_inc(outif, ifs6_out_redirect); 2704 } 2705 ICMP6STAT_INC(icp6s_outhist[ND_REDIRECT]); 2706 2707 return; 2708 2709 fail: 2710 if (m) 2711 m_freem(m); 2712 if (m0) 2713 m_freem(m0); 2714 } 2715 2716 /* 2717 * ICMPv6 socket option processing. 2718 */ 2719 int 2720 icmp6_ctloutput(struct socket *so, struct sockopt *sopt) 2721 { 2722 int error = 0; 2723 int optlen; 2724 struct inpcb *inp = sotoinpcb(so); 2725 int level, op, optname; 2726 2727 if (sopt) { 2728 level = sopt->sopt_level; 2729 op = sopt->sopt_dir; 2730 optname = sopt->sopt_name; 2731 optlen = sopt->sopt_valsize; 2732 } else 2733 level = op = optname = optlen = 0; 2734 2735 if (level != IPPROTO_ICMPV6) { 2736 return EINVAL; 2737 } 2738 2739 switch (op) { 2740 case PRCO_SETOPT: 2741 switch (optname) { 2742 case ICMP6_FILTER: 2743 { 2744 struct icmp6_filter ic6f; 2745 2746 if (optlen != sizeof(ic6f)) { 2747 error = EMSGSIZE; 2748 break; 2749 } 2750 error = sooptcopyin(sopt, &ic6f, optlen, optlen); 2751 if (error == 0) { 2752 INP_WLOCK(inp); 2753 *inp->in6p_icmp6filt = ic6f; 2754 INP_WUNLOCK(inp); 2755 } 2756 break; 2757 } 2758 2759 default: 2760 error = ENOPROTOOPT; 2761 break; 2762 } 2763 break; 2764 2765 case PRCO_GETOPT: 2766 switch (optname) { 2767 case ICMP6_FILTER: 2768 { 2769 struct icmp6_filter ic6f; 2770 2771 INP_RLOCK(inp); 2772 ic6f = *inp->in6p_icmp6filt; 2773 INP_RUNLOCK(inp); 2774 error = sooptcopyout(sopt, &ic6f, sizeof(ic6f)); 2775 break; 2776 } 2777 2778 default: 2779 error = ENOPROTOOPT; 2780 break; 2781 } 2782 break; 2783 } 2784 2785 return (error); 2786 } 2787 2788 /* 2789 * Perform rate limit check. 2790 * Returns 0 if it is okay to send the icmp6 packet. 2791 * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate 2792 * limitation. 2793 * 2794 * XXX per-destination/type check necessary? 2795 * 2796 * dst - not used at this moment 2797 * type - not used at this moment 2798 * code - not used at this moment 2799 */ 2800 static int 2801 icmp6_ratelimit(const struct in6_addr *dst, const int type, 2802 const int code) 2803 { 2804 int ret; 2805 2806 ret = 0; /* okay to send */ 2807 2808 /* PPS limit */ 2809 if (!ppsratecheck(&V_icmp6errppslim_last, &V_icmp6errpps_count, 2810 V_icmp6errppslim)) { 2811 /* The packet is subject to rate limit */ 2812 ret++; 2813 } 2814 2815 return ret; 2816 }
Cache object: 5b6f9daf85d26389ce6d31e66389dc01
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