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