icmp6.c revision 180850
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: head/sys/netinet6/icmp6.c 180850 2008-07-27 20:30:34Z mav $"); 65 66#include "opt_inet.h" 67#include "opt_inet6.h" 68#include "opt_ipsec.h" 69 70#include <sys/param.h> 71#include <sys/domain.h> 72#include <sys/kernel.h> 73#include <sys/lock.h> 74#include <sys/malloc.h> 75#include <sys/mbuf.h> 76#include <sys/protosw.h> 77#include <sys/signalvar.h> 78#include <sys/socket.h> 79#include <sys/socketvar.h> 80#include <sys/sx.h> 81#include <sys/syslog.h> 82#include <sys/systm.h> 83#include <sys/time.h> 84 85#include <net/if.h> 86#include <net/if_dl.h> 87#include <net/if_types.h> 88#include <net/route.h> 89 90#include <netinet/in.h> 91#include <netinet/in_pcb.h> 92#include <netinet/in_var.h> 93#include <netinet/ip6.h> 94#include <netinet/icmp6.h> 95#include <netinet/tcp_var.h> 96#include <netinet6/in6_ifattach.h> 97#include <netinet6/in6_pcb.h> 98#include <netinet6/ip6protosw.h> 99#include <netinet6/ip6_var.h> 100#include <netinet6/scope6_var.h> 101#include <netinet6/mld6_var.h> 102#include <netinet6/nd6.h> 103 104#ifdef IPSEC 105#include <netipsec/ipsec.h> 106#include <netipsec/key.h> 107#endif 108 109extern struct domain inet6domain; 110 111struct icmp6stat icmp6stat; 112 113extern struct inpcbinfo ripcbinfo; 114extern struct inpcbhead ripcb; 115extern int icmp6errppslim; 116static int icmp6errpps_count = 0; 117static struct timeval icmp6errppslim_last; 118extern int icmp6_nodeinfo; 119 120static void icmp6_errcount(struct icmp6errstat *, int, int); 121static int icmp6_rip6_input(struct mbuf **, int); 122static int icmp6_ratelimit(const struct in6_addr *, const int, const int); 123static const char *icmp6_redirect_diag __P((struct in6_addr *, 124 struct in6_addr *, struct in6_addr *)); 125static struct mbuf *ni6_input(struct mbuf *, int); 126static struct mbuf *ni6_nametodns(const char *, int, int); 127static int ni6_dnsmatch(const char *, int, const char *, int); 128static int ni6_addrs __P((struct icmp6_nodeinfo *, struct mbuf *, 129 struct ifnet **, struct in6_addr *)); 130static int ni6_store_addrs __P((struct icmp6_nodeinfo *, struct icmp6_nodeinfo *, 131 struct ifnet *, int)); 132static int icmp6_notify_error(struct mbuf **, int, int, int); 133 134 135void 136icmp6_init(void) 137{ 138 139 mld6_init(); 140} 141 142static void 143icmp6_errcount(struct icmp6errstat *stat, int type, int code) 144{ 145 switch (type) { 146 case ICMP6_DST_UNREACH: 147 switch (code) { 148 case ICMP6_DST_UNREACH_NOROUTE: 149 stat->icp6errs_dst_unreach_noroute++; 150 return; 151 case ICMP6_DST_UNREACH_ADMIN: 152 stat->icp6errs_dst_unreach_admin++; 153 return; 154 case ICMP6_DST_UNREACH_BEYONDSCOPE: 155 stat->icp6errs_dst_unreach_beyondscope++; 156 return; 157 case ICMP6_DST_UNREACH_ADDR: 158 stat->icp6errs_dst_unreach_addr++; 159 return; 160 case ICMP6_DST_UNREACH_NOPORT: 161 stat->icp6errs_dst_unreach_noport++; 162 return; 163 } 164 break; 165 case ICMP6_PACKET_TOO_BIG: 166 stat->icp6errs_packet_too_big++; 167 return; 168 case ICMP6_TIME_EXCEEDED: 169 switch (code) { 170 case ICMP6_TIME_EXCEED_TRANSIT: 171 stat->icp6errs_time_exceed_transit++; 172 return; 173 case ICMP6_TIME_EXCEED_REASSEMBLY: 174 stat->icp6errs_time_exceed_reassembly++; 175 return; 176 } 177 break; 178 case ICMP6_PARAM_PROB: 179 switch (code) { 180 case ICMP6_PARAMPROB_HEADER: 181 stat->icp6errs_paramprob_header++; 182 return; 183 case ICMP6_PARAMPROB_NEXTHEADER: 184 stat->icp6errs_paramprob_nextheader++; 185 return; 186 case ICMP6_PARAMPROB_OPTION: 187 stat->icp6errs_paramprob_option++; 188 return; 189 } 190 break; 191 case ND_REDIRECT: 192 stat->icp6errs_redirect++; 193 return; 194 } 195 stat->icp6errs_unknown++; 196} 197 198/* 199 * A wrapper function for icmp6_error() necessary when the erroneous packet 200 * may not contain enough scope zone information. 201 */ 202void 203icmp6_error2(struct mbuf *m, int type, int code, int param, 204 struct ifnet *ifp) 205{ 206 struct ip6_hdr *ip6; 207 208 if (ifp == NULL) 209 return; 210 211#ifndef PULLDOWN_TEST 212 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), ); 213#else 214 if (m->m_len < sizeof(struct ip6_hdr)) { 215 m = m_pullup(m, sizeof(struct ip6_hdr)); 216 if (m == NULL) 217 return; 218 } 219#endif 220 221 ip6 = mtod(m, struct ip6_hdr *); 222 223 if (in6_setscope(&ip6->ip6_src, ifp, NULL) != 0) 224 return; 225 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0) 226 return; 227 228 icmp6_error(m, type, code, param); 229} 230 231/* 232 * Generate an error packet of type error in response to bad IP6 packet. 233 */ 234void 235icmp6_error(struct mbuf *m, int type, int code, int param) 236{ 237 struct ip6_hdr *oip6, *nip6; 238 struct icmp6_hdr *icmp6; 239 u_int preplen; 240 int off; 241 int nxt; 242 243 icmp6stat.icp6s_error++; 244 245 /* count per-type-code statistics */ 246 icmp6_errcount(&icmp6stat.icp6s_outerrhist, type, code); 247 248#ifdef M_DECRYPTED /*not openbsd*/ 249 if (m->m_flags & M_DECRYPTED) { 250 icmp6stat.icp6s_canterror++; 251 goto freeit; 252 } 253#endif 254 255#ifndef PULLDOWN_TEST 256 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), ); 257#else 258 if (m->m_len < sizeof(struct ip6_hdr)) { 259 m = m_pullup(m, sizeof(struct ip6_hdr)); 260 if (m == NULL) 261 return; 262 } 263#endif 264 oip6 = mtod(m, struct ip6_hdr *); 265 266 /* 267 * If the destination address of the erroneous packet is a multicast 268 * address, or the packet was sent using link-layer multicast, 269 * we should basically suppress sending an error (RFC 2463, Section 270 * 2.4). 271 * We have two exceptions (the item e.2 in that section): 272 * - the Pakcet Too Big message can be sent for path MTU discovery. 273 * - the Parameter Problem Message that can be allowed an icmp6 error 274 * in the option type field. This check has been done in 275 * ip6_unknown_opt(), so we can just check the type and code. 276 */ 277 if ((m->m_flags & (M_BCAST|M_MCAST) || 278 IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) && 279 (type != ICMP6_PACKET_TOO_BIG && 280 (type != ICMP6_PARAM_PROB || 281 code != ICMP6_PARAMPROB_OPTION))) 282 goto freeit; 283 284 /* 285 * RFC 2463, 2.4 (e.5): source address check. 286 * XXX: the case of anycast source? 287 */ 288 if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) || 289 IN6_IS_ADDR_MULTICAST(&oip6->ip6_src)) 290 goto freeit; 291 292 /* 293 * If we are about to send ICMPv6 against ICMPv6 error/redirect, 294 * don't do it. 295 */ 296 nxt = -1; 297 off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt); 298 if (off >= 0 && nxt == IPPROTO_ICMPV6) { 299 struct icmp6_hdr *icp; 300 301#ifndef PULLDOWN_TEST 302 IP6_EXTHDR_CHECK(m, 0, off + sizeof(struct icmp6_hdr), ); 303 icp = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 304#else 305 IP6_EXTHDR_GET(icp, struct icmp6_hdr *, m, off, 306 sizeof(*icp)); 307 if (icp == NULL) { 308 icmp6stat.icp6s_tooshort++; 309 return; 310 } 311#endif 312 if (icp->icmp6_type < ICMP6_ECHO_REQUEST || 313 icp->icmp6_type == ND_REDIRECT) { 314 /* 315 * ICMPv6 error 316 * Special case: for redirect (which is 317 * informational) we must not send icmp6 error. 318 */ 319 icmp6stat.icp6s_canterror++; 320 goto freeit; 321 } else { 322 /* ICMPv6 informational - send the error */ 323 } 324 } else { 325 /* non-ICMPv6 - send the error */ 326 } 327 328 oip6 = mtod(m, struct ip6_hdr *); /* adjust pointer */ 329 330 /* Finally, do rate limitation check. */ 331 if (icmp6_ratelimit(&oip6->ip6_src, type, code)) { 332 icmp6stat.icp6s_toofreq++; 333 goto freeit; 334 } 335 336 /* 337 * OK, ICMP6 can be generated. 338 */ 339 340 if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN) 341 m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len); 342 343 preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 344 M_PREPEND(m, preplen, M_DONTWAIT); 345 if (m && m->m_len < preplen) 346 m = m_pullup(m, preplen); 347 if (m == NULL) { 348 nd6log((LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__)); 349 return; 350 } 351 352 nip6 = mtod(m, struct ip6_hdr *); 353 nip6->ip6_src = oip6->ip6_src; 354 nip6->ip6_dst = oip6->ip6_dst; 355 356 in6_clearscope(&oip6->ip6_src); 357 in6_clearscope(&oip6->ip6_dst); 358 359 icmp6 = (struct icmp6_hdr *)(nip6 + 1); 360 icmp6->icmp6_type = type; 361 icmp6->icmp6_code = code; 362 icmp6->icmp6_pptr = htonl((u_int32_t)param); 363 364 /* 365 * icmp6_reflect() is designed to be in the input path. 366 * icmp6_error() can be called from both input and output path, 367 * and if we are in output path rcvif could contain bogus value. 368 * clear m->m_pkthdr.rcvif for safety, we should have enough scope 369 * information in ip header (nip6). 370 */ 371 m->m_pkthdr.rcvif = NULL; 372 373 icmp6stat.icp6s_outhist[type]++; 374 icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */ 375 376 return; 377 378 freeit: 379 /* 380 * If we can't tell whether or not we can generate ICMP6, free it. 381 */ 382 m_freem(m); 383} 384 385/* 386 * Process a received ICMP6 message. 387 */ 388int 389icmp6_input(struct mbuf **mp, int *offp, int proto) 390{ 391 struct mbuf *m = *mp, *n; 392 struct ip6_hdr *ip6, *nip6; 393 struct icmp6_hdr *icmp6, *nicmp6; 394 int off = *offp; 395 int icmp6len = m->m_pkthdr.len - *offp; 396 int code, sum, noff; 397 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 398 399#ifndef PULLDOWN_TEST 400 IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_hdr), IPPROTO_DONE); 401 /* m might change if M_LOOP. So, call mtod after this */ 402#endif 403 404 /* 405 * Locate icmp6 structure in mbuf, and check 406 * that not corrupted and of at least minimum length 407 */ 408 409 ip6 = mtod(m, struct ip6_hdr *); 410 if (icmp6len < sizeof(struct icmp6_hdr)) { 411 icmp6stat.icp6s_tooshort++; 412 goto freeit; 413 } 414 415 /* 416 * calculate the checksum 417 */ 418#ifndef PULLDOWN_TEST 419 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off); 420#else 421 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6)); 422 if (icmp6 == NULL) { 423 icmp6stat.icp6s_tooshort++; 424 return IPPROTO_DONE; 425 } 426#endif 427 code = icmp6->icmp6_code; 428 429 if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) { 430 nd6log((LOG_ERR, 431 "ICMP6 checksum error(%d|%x) %s\n", 432 icmp6->icmp6_type, sum, 433 ip6_sprintf(ip6bufs, &ip6->ip6_src))); 434 icmp6stat.icp6s_checksum++; 435 goto freeit; 436 } 437 438 if (faithprefix_p != NULL && (*faithprefix_p)(&ip6->ip6_dst)) { 439 /* 440 * Deliver very specific ICMP6 type only. 441 * This is important to deliver TOOBIG. Otherwise PMTUD 442 * will not work. 443 */ 444 switch (icmp6->icmp6_type) { 445 case ICMP6_DST_UNREACH: 446 case ICMP6_PACKET_TOO_BIG: 447 case ICMP6_TIME_EXCEEDED: 448 break; 449 default: 450 goto freeit; 451 } 452 } 453 454 icmp6stat.icp6s_inhist[icmp6->icmp6_type]++; 455 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_msg); 456 if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK) 457 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_error); 458 459 switch (icmp6->icmp6_type) { 460 case ICMP6_DST_UNREACH: 461 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_dstunreach); 462 switch (code) { 463 case ICMP6_DST_UNREACH_NOROUTE: 464 code = PRC_UNREACH_NET; 465 break; 466 case ICMP6_DST_UNREACH_ADMIN: 467 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_adminprohib); 468 code = PRC_UNREACH_PROTOCOL; /* is this a good code? */ 469 break; 470 case ICMP6_DST_UNREACH_ADDR: 471 code = PRC_HOSTDEAD; 472 break; 473 case ICMP6_DST_UNREACH_BEYONDSCOPE: 474 /* I mean "source address was incorrect." */ 475 code = PRC_PARAMPROB; 476 break; 477 case ICMP6_DST_UNREACH_NOPORT: 478 code = PRC_UNREACH_PORT; 479 break; 480 default: 481 goto badcode; 482 } 483 goto deliver; 484 break; 485 486 case ICMP6_PACKET_TOO_BIG: 487 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_pkttoobig); 488 489 /* validation is made in icmp6_mtudisc_update */ 490 491 code = PRC_MSGSIZE; 492 493 /* 494 * Updating the path MTU will be done after examining 495 * intermediate extension headers. 496 */ 497 goto deliver; 498 break; 499 500 case ICMP6_TIME_EXCEEDED: 501 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_timeexceed); 502 switch (code) { 503 case ICMP6_TIME_EXCEED_TRANSIT: 504 code = PRC_TIMXCEED_INTRANS; 505 break; 506 case ICMP6_TIME_EXCEED_REASSEMBLY: 507 code = PRC_TIMXCEED_REASS; 508 break; 509 default: 510 goto badcode; 511 } 512 goto deliver; 513 break; 514 515 case ICMP6_PARAM_PROB: 516 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_paramprob); 517 switch (code) { 518 case ICMP6_PARAMPROB_NEXTHEADER: 519 code = PRC_UNREACH_PROTOCOL; 520 break; 521 case ICMP6_PARAMPROB_HEADER: 522 case ICMP6_PARAMPROB_OPTION: 523 code = PRC_PARAMPROB; 524 break; 525 default: 526 goto badcode; 527 } 528 goto deliver; 529 break; 530 531 case ICMP6_ECHO_REQUEST: 532 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_echo); 533 if (code != 0) 534 goto badcode; 535 if ((n = m_copy(m, 0, M_COPYALL)) == NULL) { 536 /* Give up remote */ 537 break; 538 } 539 if ((n->m_flags & M_EXT) != 0 540 || n->m_len < off + sizeof(struct icmp6_hdr)) { 541 struct mbuf *n0 = n; 542 const int maxlen = sizeof(*nip6) + sizeof(*nicmp6); 543 int n0len; 544 545 MGETHDR(n, M_DONTWAIT, n0->m_type); 546 n0len = n0->m_pkthdr.len; /* save for use below */ 547 if (n) 548 M_MOVE_PKTHDR(n, n0); 549 if (n && maxlen >= MHLEN) { 550 MCLGET(n, M_DONTWAIT); 551 if ((n->m_flags & M_EXT) == 0) { 552 m_free(n); 553 n = NULL; 554 } 555 } 556 if (n == NULL) { 557 /* Give up remote */ 558 m_freem(n0); 559 break; 560 } 561 /* 562 * Copy IPv6 and ICMPv6 only. 563 */ 564 nip6 = mtod(n, struct ip6_hdr *); 565 bcopy(ip6, nip6, sizeof(struct ip6_hdr)); 566 nicmp6 = (struct icmp6_hdr *)(nip6 + 1); 567 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr)); 568 noff = sizeof(struct ip6_hdr); 569 /* new mbuf contains only ipv6+icmpv6 headers */ 570 n->m_len = noff + sizeof(struct icmp6_hdr); 571 /* 572 * Adjust mbuf. ip6_plen will be adjusted in 573 * ip6_output(). 574 */ 575 m_adj(n0, off + sizeof(struct icmp6_hdr)); 576 /* recalculate complete packet size */ 577 n->m_pkthdr.len = n0len + (noff - off); 578 n->m_next = n0; 579 } else { 580 nip6 = mtod(n, struct ip6_hdr *); 581 IP6_EXTHDR_GET(nicmp6, struct icmp6_hdr *, n, off, 582 sizeof(*nicmp6)); 583 noff = off; 584 } 585 nicmp6->icmp6_type = ICMP6_ECHO_REPLY; 586 nicmp6->icmp6_code = 0; 587 if (n) { 588 icmp6stat.icp6s_reflect++; 589 icmp6stat.icp6s_outhist[ICMP6_ECHO_REPLY]++; 590 icmp6_reflect(n, noff); 591 } 592 break; 593 594 case ICMP6_ECHO_REPLY: 595 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_echoreply); 596 if (code != 0) 597 goto badcode; 598 break; 599 600 case MLD_LISTENER_QUERY: 601 case MLD_LISTENER_REPORT: 602 if (icmp6len < sizeof(struct mld_hdr)) 603 goto badlen; 604 if (icmp6->icmp6_type == MLD_LISTENER_QUERY) /* XXX: ugly... */ 605 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mldquery); 606 else 607 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mldreport); 608 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 609 /* give up local */ 610 mld6_input(m, off); 611 m = NULL; 612 goto freeit; 613 } 614 mld6_input(n, off); 615 /* m stays. */ 616 break; 617 618 case MLD_LISTENER_DONE: 619 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mlddone); 620 if (icmp6len < sizeof(struct mld_hdr)) /* necessary? */ 621 goto badlen; 622 break; /* nothing to be done in kernel */ 623 624 case MLD_MTRACE_RESP: 625 case MLD_MTRACE: 626 /* XXX: these two are experimental. not officially defined. */ 627 /* XXX: per-interface statistics? */ 628 break; /* just pass it to applications */ 629 630 case ICMP6_WRUREQUEST: /* ICMP6_FQDN_QUERY */ 631 { 632 enum { WRU, FQDN } mode; 633 634 if (!icmp6_nodeinfo) 635 break; 636 637 if (icmp6len == sizeof(struct icmp6_hdr) + 4) 638 mode = WRU; 639 else if (icmp6len >= sizeof(struct icmp6_nodeinfo)) 640 mode = FQDN; 641 else 642 goto badlen; 643 644#define hostnamelen strlen(hostname) 645 if (mode == FQDN) { 646#ifndef PULLDOWN_TEST 647 IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_nodeinfo), 648 IPPROTO_DONE); 649#endif 650 n = m_copy(m, 0, M_COPYALL); 651 if (n) 652 n = ni6_input(n, off); 653 /* XXX meaningless if n == NULL */ 654 noff = sizeof(struct ip6_hdr); 655 } else { 656 u_char *p; 657 int maxlen, maxhlen; 658 659 /* 660 * XXX: this combination of flags is pointless, 661 * but should we keep this for compatibility? 662 */ 663 if ((icmp6_nodeinfo & 5) != 5) 664 break; 665 666 if (code != 0) 667 goto badcode; 668 maxlen = sizeof(*nip6) + sizeof(*nicmp6) + 4; 669 if (maxlen >= MCLBYTES) { 670 /* Give up remote */ 671 break; 672 } 673 MGETHDR(n, M_DONTWAIT, m->m_type); 674 if (n && maxlen > MHLEN) { 675 MCLGET(n, M_DONTWAIT); 676 if ((n->m_flags & M_EXT) == 0) { 677 m_free(n); 678 n = NULL; 679 } 680 } 681 if (n && !m_dup_pkthdr(n, m, M_DONTWAIT)) { 682 /* 683 * Previous code did a blind M_COPY_PKTHDR 684 * and said "just for rcvif". If true, then 685 * we could tolerate the dup failing (due to 686 * the deep copy of the tag chain). For now 687 * be conservative and just fail. 688 */ 689 m_free(n); 690 n = NULL; 691 } 692 if (n == NULL) { 693 /* Give up remote */ 694 break; 695 } 696 n->m_pkthdr.rcvif = NULL; 697 n->m_len = 0; 698 maxhlen = M_TRAILINGSPACE(n) - maxlen; 699 mtx_lock(&hostname_mtx); 700 if (maxhlen > hostnamelen) 701 maxhlen = hostnamelen; 702 /* 703 * Copy IPv6 and ICMPv6 only. 704 */ 705 nip6 = mtod(n, struct ip6_hdr *); 706 bcopy(ip6, nip6, sizeof(struct ip6_hdr)); 707 nicmp6 = (struct icmp6_hdr *)(nip6 + 1); 708 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr)); 709 p = (u_char *)(nicmp6 + 1); 710 bzero(p, 4); 711 bcopy(hostname, p + 4, maxhlen); /* meaningless TTL */ 712 mtx_unlock(&hostname_mtx); 713 noff = sizeof(struct ip6_hdr); 714 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + 715 sizeof(struct icmp6_hdr) + 4 + maxhlen; 716 nicmp6->icmp6_type = ICMP6_WRUREPLY; 717 nicmp6->icmp6_code = 0; 718 } 719#undef hostnamelen 720 if (n) { 721 icmp6stat.icp6s_reflect++; 722 icmp6stat.icp6s_outhist[ICMP6_WRUREPLY]++; 723 icmp6_reflect(n, noff); 724 } 725 break; 726 } 727 728 case ICMP6_WRUREPLY: 729 if (code != 0) 730 goto badcode; 731 break; 732 733 case ND_ROUTER_SOLICIT: 734 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_routersolicit); 735 if (code != 0) 736 goto badcode; 737 if (icmp6len < sizeof(struct nd_router_solicit)) 738 goto badlen; 739 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 740 /* give up local */ 741 nd6_rs_input(m, off, icmp6len); 742 m = NULL; 743 goto freeit; 744 } 745 nd6_rs_input(n, off, icmp6len); 746 /* m stays. */ 747 break; 748 749 case ND_ROUTER_ADVERT: 750 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_routeradvert); 751 if (code != 0) 752 goto badcode; 753 if (icmp6len < sizeof(struct nd_router_advert)) 754 goto badlen; 755 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 756 /* give up local */ 757 nd6_ra_input(m, off, icmp6len); 758 m = NULL; 759 goto freeit; 760 } 761 nd6_ra_input(n, off, icmp6len); 762 /* m stays. */ 763 break; 764 765 case ND_NEIGHBOR_SOLICIT: 766 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_neighborsolicit); 767 if (code != 0) 768 goto badcode; 769 if (icmp6len < sizeof(struct nd_neighbor_solicit)) 770 goto badlen; 771 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 772 /* give up local */ 773 nd6_ns_input(m, off, icmp6len); 774 m = NULL; 775 goto freeit; 776 } 777 nd6_ns_input(n, off, icmp6len); 778 /* m stays. */ 779 break; 780 781 case ND_NEIGHBOR_ADVERT: 782 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_neighboradvert); 783 if (code != 0) 784 goto badcode; 785 if (icmp6len < sizeof(struct nd_neighbor_advert)) 786 goto badlen; 787 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 788 /* give up local */ 789 nd6_na_input(m, off, icmp6len); 790 m = NULL; 791 goto freeit; 792 } 793 nd6_na_input(n, off, icmp6len); 794 /* m stays. */ 795 break; 796 797 case ND_REDIRECT: 798 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_redirect); 799 if (code != 0) 800 goto badcode; 801 if (icmp6len < sizeof(struct nd_redirect)) 802 goto badlen; 803 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 804 /* give up local */ 805 icmp6_redirect_input(m, off); 806 m = NULL; 807 goto freeit; 808 } 809 icmp6_redirect_input(n, off); 810 /* m stays. */ 811 break; 812 813 case ICMP6_ROUTER_RENUMBERING: 814 if (code != ICMP6_ROUTER_RENUMBERING_COMMAND && 815 code != ICMP6_ROUTER_RENUMBERING_RESULT) 816 goto badcode; 817 if (icmp6len < sizeof(struct icmp6_router_renum)) 818 goto badlen; 819 break; 820 821 default: 822 nd6log((LOG_DEBUG, 823 "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n", 824 icmp6->icmp6_type, ip6_sprintf(ip6bufs, &ip6->ip6_src), 825 ip6_sprintf(ip6bufd, &ip6->ip6_dst), 826 m->m_pkthdr.rcvif ? m->m_pkthdr.rcvif->if_index : 0)); 827 if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) { 828 /* ICMPv6 error: MUST deliver it by spec... */ 829 code = PRC_NCMDS; 830 /* deliver */ 831 } else { 832 /* ICMPv6 informational: MUST not deliver */ 833 break; 834 } 835 deliver: 836 if (icmp6_notify_error(&m, off, icmp6len, code)) { 837 /* In this case, m should've been freed. */ 838 return (IPPROTO_DONE); 839 } 840 break; 841 842 badcode: 843 icmp6stat.icp6s_badcode++; 844 break; 845 846 badlen: 847 icmp6stat.icp6s_badlen++; 848 break; 849 } 850 851 /* deliver the packet to appropriate sockets */ 852 icmp6_rip6_input(&m, *offp); 853 854 return IPPROTO_DONE; 855 856 freeit: 857 m_freem(m); 858 return IPPROTO_DONE; 859} 860 861static int 862icmp6_notify_error(struct mbuf **mp, int off, int icmp6len, int code) 863{ 864 struct mbuf *m = *mp; 865 struct icmp6_hdr *icmp6; 866 struct ip6_hdr *eip6; 867 u_int32_t notifymtu; 868 struct sockaddr_in6 icmp6src, icmp6dst; 869 870 if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) { 871 icmp6stat.icp6s_tooshort++; 872 goto freeit; 873 } 874#ifndef PULLDOWN_TEST 875 IP6_EXTHDR_CHECK(m, off, 876 sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr), -1); 877 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 878#else 879 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, 880 sizeof(*icmp6) + sizeof(struct ip6_hdr)); 881 if (icmp6 == NULL) { 882 icmp6stat.icp6s_tooshort++; 883 return (-1); 884 } 885#endif 886 eip6 = (struct ip6_hdr *)(icmp6 + 1); 887 888 /* Detect the upper level protocol */ 889 { 890 void (*ctlfunc)(int, struct sockaddr *, void *); 891 u_int8_t nxt = eip6->ip6_nxt; 892 int eoff = off + sizeof(struct icmp6_hdr) + 893 sizeof(struct ip6_hdr); 894 struct ip6ctlparam ip6cp; 895 struct in6_addr *finaldst = NULL; 896 int icmp6type = icmp6->icmp6_type; 897 struct ip6_frag *fh; 898 struct ip6_rthdr *rth; 899 struct ip6_rthdr0 *rth0; 900 int rthlen; 901 902 while (1) { /* XXX: should avoid infinite loop explicitly? */ 903 struct ip6_ext *eh; 904 905 switch (nxt) { 906 case IPPROTO_HOPOPTS: 907 case IPPROTO_DSTOPTS: 908 case IPPROTO_AH: 909#ifndef PULLDOWN_TEST 910 IP6_EXTHDR_CHECK(m, 0, 911 eoff + sizeof(struct ip6_ext), -1); 912 eh = (struct ip6_ext *)(mtod(m, caddr_t) + eoff); 913#else 914 IP6_EXTHDR_GET(eh, struct ip6_ext *, m, 915 eoff, sizeof(*eh)); 916 if (eh == NULL) { 917 icmp6stat.icp6s_tooshort++; 918 return (-1); 919 } 920#endif 921 922 if (nxt == IPPROTO_AH) 923 eoff += (eh->ip6e_len + 2) << 2; 924 else 925 eoff += (eh->ip6e_len + 1) << 3; 926 nxt = eh->ip6e_nxt; 927 break; 928 case IPPROTO_ROUTING: 929 /* 930 * When the erroneous packet contains a 931 * routing header, we should examine the 932 * header to determine the final destination. 933 * Otherwise, we can't properly update 934 * information that depends on the final 935 * destination (e.g. path MTU). 936 */ 937#ifndef PULLDOWN_TEST 938 IP6_EXTHDR_CHECK(m, 0, eoff + sizeof(*rth), -1); 939 rth = (struct ip6_rthdr *) 940 (mtod(m, caddr_t) + eoff); 941#else 942 IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m, 943 eoff, sizeof(*rth)); 944 if (rth == NULL) { 945 icmp6stat.icp6s_tooshort++; 946 return (-1); 947 } 948#endif 949 rthlen = (rth->ip6r_len + 1) << 3; 950 /* 951 * XXX: currently there is no 952 * officially defined type other 953 * than type-0. 954 * Note that if the segment left field 955 * is 0, all intermediate hops must 956 * have been passed. 957 */ 958 if (rth->ip6r_segleft && 959 rth->ip6r_type == IPV6_RTHDR_TYPE_0) { 960 int hops; 961 962#ifndef PULLDOWN_TEST 963 IP6_EXTHDR_CHECK(m, 0, eoff + rthlen, -1); 964 rth0 = (struct ip6_rthdr0 *) 965 (mtod(m, caddr_t) + eoff); 966#else 967 IP6_EXTHDR_GET(rth0, 968 struct ip6_rthdr0 *, m, 969 eoff, rthlen); 970 if (rth0 == NULL) { 971 icmp6stat.icp6s_tooshort++; 972 return (-1); 973 } 974#endif 975 /* just ignore a bogus header */ 976 if ((rth0->ip6r0_len % 2) == 0 && 977 (hops = rth0->ip6r0_len/2)) 978 finaldst = (struct in6_addr *)(rth0 + 1) + (hops - 1); 979 } 980 eoff += rthlen; 981 nxt = rth->ip6r_nxt; 982 break; 983 case IPPROTO_FRAGMENT: 984#ifndef PULLDOWN_TEST 985 IP6_EXTHDR_CHECK(m, 0, eoff + 986 sizeof(struct ip6_frag), -1); 987 fh = (struct ip6_frag *)(mtod(m, caddr_t) + 988 eoff); 989#else 990 IP6_EXTHDR_GET(fh, struct ip6_frag *, m, 991 eoff, sizeof(*fh)); 992 if (fh == NULL) { 993 icmp6stat.icp6s_tooshort++; 994 return (-1); 995 } 996#endif 997 /* 998 * Data after a fragment header is meaningless 999 * unless it is the first fragment, but 1000 * we'll go to the notify label for path MTU 1001 * discovery. 1002 */ 1003 if (fh->ip6f_offlg & IP6F_OFF_MASK) 1004 goto notify; 1005 1006 eoff += sizeof(struct ip6_frag); 1007 nxt = fh->ip6f_nxt; 1008 break; 1009 default: 1010 /* 1011 * This case includes ESP and the No Next 1012 * Header. In such cases going to the notify 1013 * label does not have any meaning 1014 * (i.e. ctlfunc will be NULL), but we go 1015 * anyway since we might have to update 1016 * path MTU information. 1017 */ 1018 goto notify; 1019 } 1020 } 1021 notify: 1022#ifndef PULLDOWN_TEST 1023 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 1024#else 1025 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, 1026 sizeof(*icmp6) + sizeof(struct ip6_hdr)); 1027 if (icmp6 == NULL) { 1028 icmp6stat.icp6s_tooshort++; 1029 return (-1); 1030 } 1031#endif 1032 1033 /* 1034 * retrieve parameters from the inner IPv6 header, and convert 1035 * them into sockaddr structures. 1036 * XXX: there is no guarantee that the source or destination 1037 * addresses of the inner packet are in the same scope as 1038 * the addresses of the icmp packet. But there is no other 1039 * way to determine the zone. 1040 */ 1041 eip6 = (struct ip6_hdr *)(icmp6 + 1); 1042 1043 bzero(&icmp6dst, sizeof(icmp6dst)); 1044 icmp6dst.sin6_len = sizeof(struct sockaddr_in6); 1045 icmp6dst.sin6_family = AF_INET6; 1046 if (finaldst == NULL) 1047 icmp6dst.sin6_addr = eip6->ip6_dst; 1048 else 1049 icmp6dst.sin6_addr = *finaldst; 1050 if (in6_setscope(&icmp6dst.sin6_addr, m->m_pkthdr.rcvif, NULL)) 1051 goto freeit; 1052 bzero(&icmp6src, sizeof(icmp6src)); 1053 icmp6src.sin6_len = sizeof(struct sockaddr_in6); 1054 icmp6src.sin6_family = AF_INET6; 1055 icmp6src.sin6_addr = eip6->ip6_src; 1056 if (in6_setscope(&icmp6src.sin6_addr, m->m_pkthdr.rcvif, NULL)) 1057 goto freeit; 1058 icmp6src.sin6_flowinfo = 1059 (eip6->ip6_flow & IPV6_FLOWLABEL_MASK); 1060 1061 if (finaldst == NULL) 1062 finaldst = &eip6->ip6_dst; 1063 ip6cp.ip6c_m = m; 1064 ip6cp.ip6c_icmp6 = icmp6; 1065 ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1); 1066 ip6cp.ip6c_off = eoff; 1067 ip6cp.ip6c_finaldst = finaldst; 1068 ip6cp.ip6c_src = &icmp6src; 1069 ip6cp.ip6c_nxt = nxt; 1070 1071 if (icmp6type == ICMP6_PACKET_TOO_BIG) { 1072 notifymtu = ntohl(icmp6->icmp6_mtu); 1073 ip6cp.ip6c_cmdarg = (void *)¬ifymtu; 1074 icmp6_mtudisc_update(&ip6cp, 1); /*XXX*/ 1075 } 1076 1077 ctlfunc = (void (*)(int, struct sockaddr *, void *)) 1078 (inet6sw[ip6_protox[nxt]].pr_ctlinput); 1079 if (ctlfunc) { 1080 (void) (*ctlfunc)(code, (struct sockaddr *)&icmp6dst, 1081 &ip6cp); 1082 } 1083 } 1084 *mp = m; 1085 return (0); 1086 1087 freeit: 1088 m_freem(m); 1089 return (-1); 1090} 1091 1092void 1093icmp6_mtudisc_update(struct ip6ctlparam *ip6cp, int validated) 1094{ 1095 struct in6_addr *dst = ip6cp->ip6c_finaldst; 1096 struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6; 1097 struct mbuf *m = ip6cp->ip6c_m; /* will be necessary for scope issue */ 1098 u_int mtu = ntohl(icmp6->icmp6_mtu); 1099 struct in_conninfo inc; 1100 1101#if 0 1102 /* 1103 * RFC2460 section 5, last paragraph. 1104 * even though minimum link MTU for IPv6 is IPV6_MMTU, 1105 * we may see ICMPv6 too big with mtu < IPV6_MMTU 1106 * due to packet translator in the middle. 1107 * see ip6_output() and ip6_getpmtu() "alwaysfrag" case for 1108 * special handling. 1109 */ 1110 if (mtu < IPV6_MMTU) 1111 return; 1112#endif 1113 1114 /* 1115 * we reject ICMPv6 too big with abnormally small value. 1116 * XXX what is the good definition of "abnormally small"? 1117 */ 1118 if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8) 1119 return; 1120 1121 if (!validated) 1122 return; 1123 1124 bzero(&inc, sizeof(inc)); 1125 inc.inc_flags = 1; /* IPv6 */ 1126 inc.inc6_faddr = *dst; 1127 if (in6_setscope(&inc.inc6_faddr, m->m_pkthdr.rcvif, NULL)) 1128 return; 1129 1130 if (mtu < tcp_maxmtu6(&inc, NULL)) { 1131 tcp_hc_updatemtu(&inc, mtu); 1132 icmp6stat.icp6s_pmtuchg++; 1133 } 1134} 1135 1136/* 1137 * Process a Node Information Query packet, based on 1138 * draft-ietf-ipngwg-icmp-name-lookups-07. 1139 * 1140 * Spec incompatibilities: 1141 * - IPv6 Subject address handling 1142 * - IPv4 Subject address handling support missing 1143 * - Proxy reply (answer even if it's not for me) 1144 * - joins NI group address at in6_ifattach() time only, does not cope 1145 * with hostname changes by sethostname(3) 1146 */ 1147#define hostnamelen strlen(hostname) 1148static struct mbuf * 1149ni6_input(struct mbuf *m, int off) 1150{ 1151 struct icmp6_nodeinfo *ni6, *nni6; 1152 struct mbuf *n = NULL; 1153 u_int16_t qtype; 1154 int subjlen; 1155 int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); 1156 struct ni_reply_fqdn *fqdn; 1157 int addrs; /* for NI_QTYPE_NODEADDR */ 1158 struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */ 1159 struct in6_addr in6_subj; /* subject address */ 1160 struct ip6_hdr *ip6; 1161 int oldfqdn = 0; /* if 1, return pascal string (03 draft) */ 1162 char *subj = NULL; 1163 struct in6_ifaddr *ia6 = NULL; 1164 1165 ip6 = mtod(m, struct ip6_hdr *); 1166#ifndef PULLDOWN_TEST 1167 ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off); 1168#else 1169 IP6_EXTHDR_GET(ni6, struct icmp6_nodeinfo *, m, off, sizeof(*ni6)); 1170 if (ni6 == NULL) { 1171 /* m is already reclaimed */ 1172 return (NULL); 1173 } 1174#endif 1175 1176 /* 1177 * Validate IPv6 source address. 1178 * The default configuration MUST be to refuse answering queries from 1179 * global-scope addresses according to RFC4602. 1180 * Notes: 1181 * - it's not very clear what "refuse" means; this implementation 1182 * simply drops it. 1183 * - it's not very easy to identify global-scope (unicast) addresses 1184 * since there are many prefixes for them. It should be safer 1185 * and in practice sufficient to check "all" but loopback and 1186 * link-local (note that site-local unicast was deprecated and 1187 * ULA is defined as global scope-wise) 1188 */ 1189 if ((icmp6_nodeinfo & ICMP6_NODEINFO_GLOBALOK) == 0 && 1190 !IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) && 1191 !IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) 1192 goto bad; 1193 1194 /* 1195 * Validate IPv6 destination address. 1196 * 1197 * The Responder must discard the Query without further processing 1198 * unless it is one of the Responder's unicast or anycast addresses, or 1199 * a link-local scope multicast address which the Responder has joined. 1200 * [RFC4602, Section 5.] 1201 */ 1202 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 1203 if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst)) 1204 goto bad; 1205 /* else it's a link-local multicast, fine */ 1206 } else { /* unicast or anycast */ 1207 if ((ia6 = ip6_getdstifaddr(m)) == NULL) 1208 goto bad; /* XXX impossible */ 1209 1210 if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) && 1211 !(icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK)) { 1212 nd6log((LOG_DEBUG, "ni6_input: ignore node info to " 1213 "a temporary address in %s:%d", 1214 __FILE__, __LINE__)); 1215 goto bad; 1216 } 1217 } 1218 1219 /* validate query Subject field. */ 1220 qtype = ntohs(ni6->ni_qtype); 1221 subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo); 1222 switch (qtype) { 1223 case NI_QTYPE_NOOP: 1224 case NI_QTYPE_SUPTYPES: 1225 /* 07 draft */ 1226 if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0) 1227 break; 1228 /* FALLTHROUGH */ 1229 case NI_QTYPE_FQDN: 1230 case NI_QTYPE_NODEADDR: 1231 case NI_QTYPE_IPV4ADDR: 1232 switch (ni6->ni_code) { 1233 case ICMP6_NI_SUBJ_IPV6: 1234#if ICMP6_NI_SUBJ_IPV6 != 0 1235 case 0: 1236#endif 1237 /* 1238 * backward compatibility - try to accept 03 draft 1239 * format, where no Subject is present. 1240 */ 1241 if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 && 1242 subjlen == 0) { 1243 oldfqdn++; 1244 break; 1245 } 1246#if ICMP6_NI_SUBJ_IPV6 != 0 1247 if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6) 1248 goto bad; 1249#endif 1250 1251 if (subjlen != sizeof(struct in6_addr)) 1252 goto bad; 1253 1254 /* 1255 * Validate Subject address. 1256 * 1257 * Not sure what exactly "address belongs to the node" 1258 * means in the spec, is it just unicast, or what? 1259 * 1260 * At this moment we consider Subject address as 1261 * "belong to the node" if the Subject address equals 1262 * to the IPv6 destination address; validation for 1263 * IPv6 destination address should have done enough 1264 * check for us. 1265 * 1266 * We do not do proxy at this moment. 1267 */ 1268 /* m_pulldown instead of copy? */ 1269 m_copydata(m, off + sizeof(struct icmp6_nodeinfo), 1270 subjlen, (caddr_t)&in6_subj); 1271 if (in6_setscope(&in6_subj, m->m_pkthdr.rcvif, NULL)) 1272 goto bad; 1273 1274 subj = (char *)&in6_subj; 1275 if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &in6_subj)) 1276 break; 1277 1278 /* 1279 * XXX if we are to allow other cases, we should really 1280 * be careful about scope here. 1281 * basically, we should disallow queries toward IPv6 1282 * destination X with subject Y, 1283 * if scope(X) > scope(Y). 1284 * if we allow scope(X) > scope(Y), it will result in 1285 * information leakage across scope boundary. 1286 */ 1287 goto bad; 1288 1289 case ICMP6_NI_SUBJ_FQDN: 1290 /* 1291 * Validate Subject name with gethostname(3). 1292 * 1293 * The behavior may need some debate, since: 1294 * - we are not sure if the node has FQDN as 1295 * hostname (returned by gethostname(3)). 1296 * - the code does wildcard match for truncated names. 1297 * however, we are not sure if we want to perform 1298 * wildcard match, if gethostname(3) side has 1299 * truncated hostname. 1300 */ 1301 mtx_lock(&hostname_mtx); 1302 n = ni6_nametodns(hostname, hostnamelen, 0); 1303 mtx_unlock(&hostname_mtx); 1304 if (!n || n->m_next || n->m_len == 0) 1305 goto bad; 1306 IP6_EXTHDR_GET(subj, char *, m, 1307 off + sizeof(struct icmp6_nodeinfo), subjlen); 1308 if (subj == NULL) 1309 goto bad; 1310 if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *), 1311 n->m_len)) { 1312 goto bad; 1313 } 1314 m_freem(n); 1315 n = NULL; 1316 break; 1317 1318 case ICMP6_NI_SUBJ_IPV4: /* XXX: to be implemented? */ 1319 default: 1320 goto bad; 1321 } 1322 break; 1323 } 1324 1325 /* refuse based on configuration. XXX ICMP6_NI_REFUSED? */ 1326 switch (qtype) { 1327 case NI_QTYPE_FQDN: 1328 if ((icmp6_nodeinfo & ICMP6_NODEINFO_FQDNOK) == 0) 1329 goto bad; 1330 break; 1331 case NI_QTYPE_NODEADDR: 1332 case NI_QTYPE_IPV4ADDR: 1333 if ((icmp6_nodeinfo & ICMP6_NODEINFO_NODEADDROK) == 0) 1334 goto bad; 1335 break; 1336 } 1337 1338 /* guess reply length */ 1339 switch (qtype) { 1340 case NI_QTYPE_NOOP: 1341 break; /* no reply data */ 1342 case NI_QTYPE_SUPTYPES: 1343 replylen += sizeof(u_int32_t); 1344 break; 1345 case NI_QTYPE_FQDN: 1346 /* XXX will append an mbuf */ 1347 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); 1348 break; 1349 case NI_QTYPE_NODEADDR: 1350 addrs = ni6_addrs(ni6, m, &ifp, (struct in6_addr *)subj); 1351 if ((replylen += addrs * (sizeof(struct in6_addr) + 1352 sizeof(u_int32_t))) > MCLBYTES) 1353 replylen = MCLBYTES; /* XXX: will truncate pkt later */ 1354 break; 1355 case NI_QTYPE_IPV4ADDR: 1356 /* unsupported - should respond with unknown Qtype? */ 1357 break; 1358 default: 1359 /* 1360 * XXX: We must return a reply with the ICMP6 code 1361 * `unknown Qtype' in this case. However we regard the case 1362 * as an FQDN query for backward compatibility. 1363 * Older versions set a random value to this field, 1364 * so it rarely varies in the defined qtypes. 1365 * But the mechanism is not reliable... 1366 * maybe we should obsolete older versions. 1367 */ 1368 qtype = NI_QTYPE_FQDN; 1369 /* XXX will append an mbuf */ 1370 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); 1371 oldfqdn++; 1372 break; 1373 } 1374 1375 /* allocate an mbuf to reply. */ 1376 MGETHDR(n, M_DONTWAIT, m->m_type); 1377 if (n == NULL) { 1378 m_freem(m); 1379 return (NULL); 1380 } 1381 M_MOVE_PKTHDR(n, m); /* just for recvif */ 1382 if (replylen > MHLEN) { 1383 if (replylen > MCLBYTES) { 1384 /* 1385 * XXX: should we try to allocate more? But MCLBYTES 1386 * is probably much larger than IPV6_MMTU... 1387 */ 1388 goto bad; 1389 } 1390 MCLGET(n, M_DONTWAIT); 1391 if ((n->m_flags & M_EXT) == 0) { 1392 goto bad; 1393 } 1394 } 1395 n->m_pkthdr.len = n->m_len = replylen; 1396 1397 /* copy mbuf header and IPv6 + Node Information base headers */ 1398 bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr)); 1399 nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1); 1400 bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo)); 1401 1402 /* qtype dependent procedure */ 1403 switch (qtype) { 1404 case NI_QTYPE_NOOP: 1405 nni6->ni_code = ICMP6_NI_SUCCESS; 1406 nni6->ni_flags = 0; 1407 break; 1408 case NI_QTYPE_SUPTYPES: 1409 { 1410 u_int32_t v; 1411 nni6->ni_code = ICMP6_NI_SUCCESS; 1412 nni6->ni_flags = htons(0x0000); /* raw bitmap */ 1413 /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */ 1414 v = (u_int32_t)htonl(0x0000000f); 1415 bcopy(&v, nni6 + 1, sizeof(u_int32_t)); 1416 break; 1417 } 1418 case NI_QTYPE_FQDN: 1419 nni6->ni_code = ICMP6_NI_SUCCESS; 1420 fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) + 1421 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo)); 1422 nni6->ni_flags = 0; /* XXX: meaningless TTL */ 1423 fqdn->ni_fqdn_ttl = 0; /* ditto. */ 1424 /* 1425 * XXX do we really have FQDN in variable "hostname"? 1426 */ 1427 mtx_lock(&hostname_mtx); 1428 n->m_next = ni6_nametodns(hostname, hostnamelen, oldfqdn); 1429 mtx_unlock(&hostname_mtx); 1430 if (n->m_next == NULL) 1431 goto bad; 1432 /* XXX we assume that n->m_next is not a chain */ 1433 if (n->m_next->m_next != NULL) 1434 goto bad; 1435 n->m_pkthdr.len += n->m_next->m_len; 1436 break; 1437 case NI_QTYPE_NODEADDR: 1438 { 1439 int lenlim, copied; 1440 1441 nni6->ni_code = ICMP6_NI_SUCCESS; 1442 n->m_pkthdr.len = n->m_len = 1443 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); 1444 lenlim = M_TRAILINGSPACE(n); 1445 copied = ni6_store_addrs(ni6, nni6, ifp, lenlim); 1446 /* XXX: reset mbuf length */ 1447 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + 1448 sizeof(struct icmp6_nodeinfo) + copied; 1449 break; 1450 } 1451 default: 1452 break; /* XXX impossible! */ 1453 } 1454 1455 nni6->ni_type = ICMP6_NI_REPLY; 1456 m_freem(m); 1457 return (n); 1458 1459 bad: 1460 m_freem(m); 1461 if (n) 1462 m_freem(n); 1463 return (NULL); 1464} 1465#undef hostnamelen 1466 1467/* 1468 * make a mbuf with DNS-encoded string. no compression support. 1469 * 1470 * XXX names with less than 2 dots (like "foo" or "foo.section") will be 1471 * treated as truncated name (two \0 at the end). this is a wild guess. 1472 * 1473 * old - return pascal string if non-zero 1474 */ 1475static struct mbuf * 1476ni6_nametodns(const char *name, int namelen, int old) 1477{ 1478 struct mbuf *m; 1479 char *cp, *ep; 1480 const char *p, *q; 1481 int i, len, nterm; 1482 1483 if (old) 1484 len = namelen + 1; 1485 else 1486 len = MCLBYTES; 1487 1488 /* because MAXHOSTNAMELEN is usually 256, we use cluster mbuf */ 1489 MGET(m, M_DONTWAIT, MT_DATA); 1490 if (m && len > MLEN) { 1491 MCLGET(m, M_DONTWAIT); 1492 if ((m->m_flags & M_EXT) == 0) 1493 goto fail; 1494 } 1495 if (!m) 1496 goto fail; 1497 m->m_next = NULL; 1498 1499 if (old) { 1500 m->m_len = len; 1501 *mtod(m, char *) = namelen; 1502 bcopy(name, mtod(m, char *) + 1, namelen); 1503 return m; 1504 } else { 1505 m->m_len = 0; 1506 cp = mtod(m, char *); 1507 ep = mtod(m, char *) + M_TRAILINGSPACE(m); 1508 1509 /* if not certain about my name, return empty buffer */ 1510 if (namelen == 0) 1511 return m; 1512 1513 /* 1514 * guess if it looks like shortened hostname, or FQDN. 1515 * shortened hostname needs two trailing "\0". 1516 */ 1517 i = 0; 1518 for (p = name; p < name + namelen; p++) { 1519 if (*p && *p == '.') 1520 i++; 1521 } 1522 if (i < 2) 1523 nterm = 2; 1524 else 1525 nterm = 1; 1526 1527 p = name; 1528 while (cp < ep && p < name + namelen) { 1529 i = 0; 1530 for (q = p; q < name + namelen && *q && *q != '.'; q++) 1531 i++; 1532 /* result does not fit into mbuf */ 1533 if (cp + i + 1 >= ep) 1534 goto fail; 1535 /* 1536 * DNS label length restriction, RFC1035 page 8. 1537 * "i == 0" case is included here to avoid returning 1538 * 0-length label on "foo..bar". 1539 */ 1540 if (i <= 0 || i >= 64) 1541 goto fail; 1542 *cp++ = i; 1543 bcopy(p, cp, i); 1544 cp += i; 1545 p = q; 1546 if (p < name + namelen && *p == '.') 1547 p++; 1548 } 1549 /* termination */ 1550 if (cp + nterm >= ep) 1551 goto fail; 1552 while (nterm-- > 0) 1553 *cp++ = '\0'; 1554 m->m_len = cp - mtod(m, char *); 1555 return m; 1556 } 1557 1558 panic("should not reach here"); 1559 /* NOTREACHED */ 1560 1561 fail: 1562 if (m) 1563 m_freem(m); 1564 return NULL; 1565} 1566 1567/* 1568 * check if two DNS-encoded string matches. takes care of truncated 1569 * form (with \0\0 at the end). no compression support. 1570 * XXX upper/lowercase match (see RFC2065) 1571 */ 1572static int 1573ni6_dnsmatch(const char *a, int alen, const char *b, int blen) 1574{ 1575 const char *a0, *b0; 1576 int l; 1577 1578 /* simplest case - need validation? */ 1579 if (alen == blen && bcmp(a, b, alen) == 0) 1580 return 1; 1581 1582 a0 = a; 1583 b0 = b; 1584 1585 /* termination is mandatory */ 1586 if (alen < 2 || blen < 2) 1587 return 0; 1588 if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0') 1589 return 0; 1590 alen--; 1591 blen--; 1592 1593 while (a - a0 < alen && b - b0 < blen) { 1594 if (a - a0 + 1 > alen || b - b0 + 1 > blen) 1595 return 0; 1596 1597 if ((signed char)a[0] < 0 || (signed char)b[0] < 0) 1598 return 0; 1599 /* we don't support compression yet */ 1600 if (a[0] >= 64 || b[0] >= 64) 1601 return 0; 1602 1603 /* truncated case */ 1604 if (a[0] == 0 && a - a0 == alen - 1) 1605 return 1; 1606 if (b[0] == 0 && b - b0 == blen - 1) 1607 return 1; 1608 if (a[0] == 0 || b[0] == 0) 1609 return 0; 1610 1611 if (a[0] != b[0]) 1612 return 0; 1613 l = a[0]; 1614 if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen) 1615 return 0; 1616 if (bcmp(a + 1, b + 1, l) != 0) 1617 return 0; 1618 1619 a += 1 + l; 1620 b += 1 + l; 1621 } 1622 1623 if (a - a0 == alen && b - b0 == blen) 1624 return 1; 1625 else 1626 return 0; 1627} 1628 1629/* 1630 * calculate the number of addresses to be returned in the node info reply. 1631 */ 1632static int 1633ni6_addrs(struct icmp6_nodeinfo *ni6, struct mbuf *m, struct ifnet **ifpp, 1634 struct in6_addr *subj) 1635{ 1636 struct ifnet *ifp; 1637 struct in6_ifaddr *ifa6; 1638 struct ifaddr *ifa; 1639 int addrs = 0, addrsofif, iffound = 0; 1640 int niflags = ni6->ni_flags; 1641 1642 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) { 1643 switch (ni6->ni_code) { 1644 case ICMP6_NI_SUBJ_IPV6: 1645 if (subj == NULL) /* must be impossible... */ 1646 return (0); 1647 break; 1648 default: 1649 /* 1650 * XXX: we only support IPv6 subject address for 1651 * this Qtype. 1652 */ 1653 return (0); 1654 } 1655 } 1656 1657 IFNET_RLOCK(); 1658 for (ifp = TAILQ_FIRST(&ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list)) { 1659 addrsofif = 0; 1660 TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) { 1661 if (ifa->ifa_addr->sa_family != AF_INET6) 1662 continue; 1663 ifa6 = (struct in6_ifaddr *)ifa; 1664 1665 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 && 1666 IN6_ARE_ADDR_EQUAL(subj, &ifa6->ia_addr.sin6_addr)) 1667 iffound = 1; 1668 1669 /* 1670 * IPv4-mapped addresses can only be returned by a 1671 * Node Information proxy, since they represent 1672 * addresses of IPv4-only nodes, which perforce do 1673 * not implement this protocol. 1674 * [icmp-name-lookups-07, Section 5.4] 1675 * So we don't support NI_NODEADDR_FLAG_COMPAT in 1676 * this function at this moment. 1677 */ 1678 1679 /* What do we have to do about ::1? */ 1680 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { 1681 case IPV6_ADDR_SCOPE_LINKLOCAL: 1682 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) 1683 continue; 1684 break; 1685 case IPV6_ADDR_SCOPE_SITELOCAL: 1686 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) 1687 continue; 1688 break; 1689 case IPV6_ADDR_SCOPE_GLOBAL: 1690 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) 1691 continue; 1692 break; 1693 default: 1694 continue; 1695 } 1696 1697 /* 1698 * check if anycast is okay. 1699 * XXX: just experimental. not in the spec. 1700 */ 1701 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && 1702 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) 1703 continue; /* we need only unicast addresses */ 1704 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && 1705 (icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) { 1706 continue; 1707 } 1708 addrsofif++; /* count the address */ 1709 } 1710 if (iffound) { 1711 *ifpp = ifp; 1712 IFNET_RUNLOCK(); 1713 return (addrsofif); 1714 } 1715 1716 addrs += addrsofif; 1717 } 1718 IFNET_RUNLOCK(); 1719 1720 return (addrs); 1721} 1722 1723static int 1724ni6_store_addrs(struct icmp6_nodeinfo *ni6, struct icmp6_nodeinfo *nni6, 1725 struct ifnet *ifp0, int resid) 1726{ 1727 struct ifnet *ifp = ifp0 ? ifp0 : TAILQ_FIRST(&ifnet); 1728 struct in6_ifaddr *ifa6; 1729 struct ifaddr *ifa; 1730 struct ifnet *ifp_dep = NULL; 1731 int copied = 0, allow_deprecated = 0; 1732 u_char *cp = (u_char *)(nni6 + 1); 1733 int niflags = ni6->ni_flags; 1734 u_int32_t ltime; 1735 1736 if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL)) 1737 return (0); /* needless to copy */ 1738 1739 IFNET_RLOCK(); 1740 again: 1741 1742 for (; ifp; ifp = TAILQ_NEXT(ifp, if_list)) { 1743 for (ifa = ifp->if_addrlist.tqh_first; ifa; 1744 ifa = ifa->ifa_list.tqe_next) { 1745 if (ifa->ifa_addr->sa_family != AF_INET6) 1746 continue; 1747 ifa6 = (struct in6_ifaddr *)ifa; 1748 1749 if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 && 1750 allow_deprecated == 0) { 1751 /* 1752 * prefererred address should be put before 1753 * deprecated addresses. 1754 */ 1755 1756 /* record the interface for later search */ 1757 if (ifp_dep == NULL) 1758 ifp_dep = ifp; 1759 1760 continue; 1761 } else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 && 1762 allow_deprecated != 0) 1763 continue; /* we now collect deprecated addrs */ 1764 1765 /* What do we have to do about ::1? */ 1766 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { 1767 case IPV6_ADDR_SCOPE_LINKLOCAL: 1768 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) 1769 continue; 1770 break; 1771 case IPV6_ADDR_SCOPE_SITELOCAL: 1772 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) 1773 continue; 1774 break; 1775 case IPV6_ADDR_SCOPE_GLOBAL: 1776 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) 1777 continue; 1778 break; 1779 default: 1780 continue; 1781 } 1782 1783 /* 1784 * check if anycast is okay. 1785 * XXX: just experimental. not in the spec. 1786 */ 1787 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && 1788 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) 1789 continue; 1790 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && 1791 (icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) { 1792 continue; 1793 } 1794 1795 /* now we can copy the address */ 1796 if (resid < sizeof(struct in6_addr) + 1797 sizeof(u_int32_t)) { 1798 /* 1799 * We give up much more copy. 1800 * Set the truncate flag and return. 1801 */ 1802 nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE; 1803 IFNET_RUNLOCK(); 1804 return (copied); 1805 } 1806 1807 /* 1808 * Set the TTL of the address. 1809 * The TTL value should be one of the following 1810 * according to the specification: 1811 * 1812 * 1. The remaining lifetime of a DHCP lease on the 1813 * address, or 1814 * 2. The remaining Valid Lifetime of a prefix from 1815 * which the address was derived through Stateless 1816 * Autoconfiguration. 1817 * 1818 * Note that we currently do not support stateful 1819 * address configuration by DHCPv6, so the former 1820 * case can't happen. 1821 */ 1822 if (ifa6->ia6_lifetime.ia6t_expire == 0) 1823 ltime = ND6_INFINITE_LIFETIME; 1824 else { 1825 if (ifa6->ia6_lifetime.ia6t_expire > 1826 time_second) 1827 ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_second); 1828 else 1829 ltime = 0; 1830 } 1831 1832 bcopy(<ime, cp, sizeof(u_int32_t)); 1833 cp += sizeof(u_int32_t); 1834 1835 /* copy the address itself */ 1836 bcopy(&ifa6->ia_addr.sin6_addr, cp, 1837 sizeof(struct in6_addr)); 1838 in6_clearscope((struct in6_addr *)cp); /* XXX */ 1839 cp += sizeof(struct in6_addr); 1840 1841 resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t)); 1842 copied += (sizeof(struct in6_addr) + sizeof(u_int32_t)); 1843 } 1844 if (ifp0) /* we need search only on the specified IF */ 1845 break; 1846 } 1847 1848 if (allow_deprecated == 0 && ifp_dep != NULL) { 1849 ifp = ifp_dep; 1850 allow_deprecated = 1; 1851 1852 goto again; 1853 } 1854 1855 IFNET_RUNLOCK(); 1856 1857 return (copied); 1858} 1859 1860/* 1861 * XXX almost dup'ed code with rip6_input. 1862 */ 1863static int 1864icmp6_rip6_input(struct mbuf **mp, int off) 1865{ 1866 struct mbuf *m = *mp; 1867 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1868 struct in6pcb *in6p; 1869 struct in6pcb *last = NULL; 1870 struct sockaddr_in6 fromsa; 1871 struct icmp6_hdr *icmp6; 1872 struct mbuf *opts = NULL; 1873 1874#ifndef PULLDOWN_TEST 1875 /* this is assumed to be safe. */ 1876 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off); 1877#else 1878 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6)); 1879 if (icmp6 == NULL) { 1880 /* m is already reclaimed */ 1881 return (IPPROTO_DONE); 1882 } 1883#endif 1884 1885 /* 1886 * XXX: the address may have embedded scope zone ID, which should be 1887 * hidden from applications. 1888 */ 1889 bzero(&fromsa, sizeof(fromsa)); 1890 fromsa.sin6_family = AF_INET6; 1891 fromsa.sin6_len = sizeof(struct sockaddr_in6); 1892 fromsa.sin6_addr = ip6->ip6_src; 1893 if (sa6_recoverscope(&fromsa)) { 1894 m_freem(m); 1895 return (IPPROTO_DONE); 1896 } 1897 1898 INP_INFO_RLOCK(&ripcbinfo); 1899 LIST_FOREACH(in6p, &ripcb, inp_list) { 1900 if ((in6p->inp_vflag & INP_IPV6) == 0) 1901 continue; 1902 if (in6p->in6p_ip6_nxt != IPPROTO_ICMPV6) 1903 continue; 1904 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) && 1905 !IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &ip6->ip6_dst)) 1906 continue; 1907 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr) && 1908 !IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src)) 1909 continue; 1910 if (in6p->in6p_icmp6filt 1911 && ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type, 1912 in6p->in6p_icmp6filt)) 1913 continue; 1914 if (last) { 1915 struct mbuf *n = NULL; 1916 1917 /* 1918 * Recent network drivers tend to allocate a single 1919 * mbuf cluster, rather than to make a couple of 1920 * mbufs without clusters. Also, since the IPv6 code 1921 * path tries to avoid m_pullup(), it is highly 1922 * probable that we still have an mbuf cluster here 1923 * even though the necessary length can be stored in an 1924 * mbuf's internal buffer. 1925 * Meanwhile, the default size of the receive socket 1926 * buffer for raw sockets is not so large. This means 1927 * the possibility of packet loss is relatively higher 1928 * than before. To avoid this scenario, we copy the 1929 * received data to a separate mbuf that does not use 1930 * a cluster, if possible. 1931 * XXX: it is better to copy the data after stripping 1932 * intermediate headers. 1933 */ 1934 if ((m->m_flags & M_EXT) && m->m_next == NULL && 1935 m->m_len <= MHLEN) { 1936 MGET(n, M_DONTWAIT, m->m_type); 1937 if (n != NULL) { 1938 if (m_dup_pkthdr(n, m, M_NOWAIT)) { 1939 bcopy(m->m_data, n->m_data, 1940 m->m_len); 1941 n->m_len = m->m_len; 1942 } else { 1943 m_free(n); 1944 n = NULL; 1945 } 1946 } 1947 } 1948 if (n != NULL || 1949 (n = m_copy(m, 0, (int)M_COPYALL)) != NULL) { 1950 if (last->in6p_flags & IN6P_CONTROLOPTS) 1951 ip6_savecontrol(last, n, &opts); 1952 /* strip intermediate headers */ 1953 m_adj(n, off); 1954 SOCKBUF_LOCK(&last->in6p_socket->so_rcv); 1955 if (sbappendaddr_locked( 1956 &last->in6p_socket->so_rcv, 1957 (struct sockaddr *)&fromsa, n, opts) 1958 == 0) { 1959 /* should notify about lost packet */ 1960 m_freem(n); 1961 if (opts) { 1962 m_freem(opts); 1963 } 1964 SOCKBUF_UNLOCK( 1965 &last->in6p_socket->so_rcv); 1966 } else 1967 sorwakeup_locked(last->in6p_socket); 1968 opts = NULL; 1969 } 1970 INP_RUNLOCK(last); 1971 } 1972 last = in6p; 1973 INP_RLOCK(last); 1974 } 1975 INP_INFO_RUNLOCK(&ripcbinfo); 1976 if (last) { 1977 if (last->in6p_flags & IN6P_CONTROLOPTS) 1978 ip6_savecontrol(last, m, &opts); 1979 /* strip intermediate headers */ 1980 m_adj(m, off); 1981 1982 /* avoid using mbuf clusters if possible (see above) */ 1983 if ((m->m_flags & M_EXT) && m->m_next == NULL && 1984 m->m_len <= MHLEN) { 1985 struct mbuf *n; 1986 1987 MGET(n, M_DONTWAIT, m->m_type); 1988 if (n != NULL) { 1989 if (m_dup_pkthdr(n, m, M_NOWAIT)) { 1990 bcopy(m->m_data, n->m_data, m->m_len); 1991 n->m_len = m->m_len; 1992 1993 m_freem(m); 1994 m = n; 1995 } else { 1996 m_freem(n); 1997 n = NULL; 1998 } 1999 } 2000 } 2001 SOCKBUF_LOCK(&last->in6p_socket->so_rcv); 2002 if (sbappendaddr_locked(&last->in6p_socket->so_rcv, 2003 (struct sockaddr *)&fromsa, m, opts) == 0) { 2004 m_freem(m); 2005 if (opts) 2006 m_freem(opts); 2007 SOCKBUF_UNLOCK(&last->in6p_socket->so_rcv); 2008 } else 2009 sorwakeup_locked(last->in6p_socket); 2010 INP_RUNLOCK(last); 2011 } else { 2012 m_freem(m); 2013 ip6stat.ip6s_delivered--; 2014 } 2015 return IPPROTO_DONE; 2016} 2017 2018/* 2019 * Reflect the ip6 packet back to the source. 2020 * OFF points to the icmp6 header, counted from the top of the mbuf. 2021 */ 2022void 2023icmp6_reflect(struct mbuf *m, size_t off) 2024{ 2025 struct ip6_hdr *ip6; 2026 struct icmp6_hdr *icmp6; 2027 struct in6_ifaddr *ia; 2028 int plen; 2029 int type, code; 2030 struct ifnet *outif = NULL; 2031 struct in6_addr origdst, *src = NULL; 2032 2033 /* too short to reflect */ 2034 if (off < sizeof(struct ip6_hdr)) { 2035 nd6log((LOG_DEBUG, 2036 "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n", 2037 (u_long)off, (u_long)sizeof(struct ip6_hdr), 2038 __FILE__, __LINE__)); 2039 goto bad; 2040 } 2041 2042 /* 2043 * If there are extra headers between IPv6 and ICMPv6, strip 2044 * off that header first. 2045 */ 2046#ifdef DIAGNOSTIC 2047 if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN) 2048 panic("assumption failed in icmp6_reflect"); 2049#endif 2050 if (off > sizeof(struct ip6_hdr)) { 2051 size_t l; 2052 struct ip6_hdr nip6; 2053 2054 l = off - sizeof(struct ip6_hdr); 2055 m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6); 2056 m_adj(m, l); 2057 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 2058 if (m->m_len < l) { 2059 if ((m = m_pullup(m, l)) == NULL) 2060 return; 2061 } 2062 bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6)); 2063 } else /* off == sizeof(struct ip6_hdr) */ { 2064 size_t l; 2065 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 2066 if (m->m_len < l) { 2067 if ((m = m_pullup(m, l)) == NULL) 2068 return; 2069 } 2070 } 2071 plen = m->m_pkthdr.len - sizeof(struct ip6_hdr); 2072 ip6 = mtod(m, struct ip6_hdr *); 2073 ip6->ip6_nxt = IPPROTO_ICMPV6; 2074 icmp6 = (struct icmp6_hdr *)(ip6 + 1); 2075 type = icmp6->icmp6_type; /* keep type for statistics */ 2076 code = icmp6->icmp6_code; /* ditto. */ 2077 2078 origdst = ip6->ip6_dst; 2079 /* 2080 * ip6_input() drops a packet if its src is multicast. 2081 * So, the src is never multicast. 2082 */ 2083 ip6->ip6_dst = ip6->ip6_src; 2084 2085 /* 2086 * If the incoming packet was addressed directly to us (i.e. unicast), 2087 * use dst as the src for the reply. 2088 * The IN6_IFF_NOTREADY case should be VERY rare, but is possible 2089 * (for example) when we encounter an error while forwarding procedure 2090 * destined to a duplicated address of ours. 2091 * Note that ip6_getdstifaddr() may fail if we are in an error handling 2092 * procedure of an outgoing packet of our own, in which case we need 2093 * to search in the ifaddr list. 2094 */ 2095 if (!IN6_IS_ADDR_MULTICAST(&origdst)) { 2096 if ((ia = ip6_getdstifaddr(m))) { 2097 if (!(ia->ia6_flags & 2098 (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) 2099 src = &ia->ia_addr.sin6_addr; 2100 } else { 2101 struct sockaddr_in6 d; 2102 2103 bzero(&d, sizeof(d)); 2104 d.sin6_family = AF_INET6; 2105 d.sin6_len = sizeof(d); 2106 d.sin6_addr = origdst; 2107 ia = (struct in6_ifaddr *) 2108 ifa_ifwithaddr((struct sockaddr *)&d); 2109 if (ia && 2110 !(ia->ia6_flags & 2111 (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) { 2112 src = &ia->ia_addr.sin6_addr; 2113 } 2114 } 2115 } 2116 2117 if (src == NULL) { 2118 int e; 2119 struct sockaddr_in6 sin6; 2120 struct route_in6 ro; 2121 2122 /* 2123 * This case matches to multicasts, our anycast, or unicasts 2124 * that we do not own. Select a source address based on the 2125 * source address of the erroneous packet. 2126 */ 2127 bzero(&sin6, sizeof(sin6)); 2128 sin6.sin6_family = AF_INET6; 2129 sin6.sin6_len = sizeof(sin6); 2130 sin6.sin6_addr = ip6->ip6_dst; /* zone ID should be embedded */ 2131 2132 bzero(&ro, sizeof(ro)); 2133 src = in6_selectsrc(&sin6, NULL, NULL, &ro, NULL, &outif, &e); 2134 if (ro.ro_rt) 2135 RTFREE(ro.ro_rt); /* XXX: we could use this */ 2136 if (src == NULL) { 2137 char ip6buf[INET6_ADDRSTRLEN]; 2138 nd6log((LOG_DEBUG, 2139 "icmp6_reflect: source can't be determined: " 2140 "dst=%s, error=%d\n", 2141 ip6_sprintf(ip6buf, &sin6.sin6_addr), e)); 2142 goto bad; 2143 } 2144 } 2145 2146 ip6->ip6_src = *src; 2147 ip6->ip6_flow = 0; 2148 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2149 ip6->ip6_vfc |= IPV6_VERSION; 2150 ip6->ip6_nxt = IPPROTO_ICMPV6; 2151 if (outif) 2152 ip6->ip6_hlim = ND_IFINFO(outif)->chlim; 2153 else if (m->m_pkthdr.rcvif) { 2154 /* XXX: This may not be the outgoing interface */ 2155 ip6->ip6_hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim; 2156 } else 2157 ip6->ip6_hlim = ip6_defhlim; 2158 2159 icmp6->icmp6_cksum = 0; 2160 icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2161 sizeof(struct ip6_hdr), plen); 2162 2163 /* 2164 * XXX option handling 2165 */ 2166 2167 m->m_flags &= ~(M_BCAST|M_MCAST); 2168 2169 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2170 if (outif) 2171 icmp6_ifoutstat_inc(outif, type, code); 2172 2173 return; 2174 2175 bad: 2176 m_freem(m); 2177 return; 2178} 2179 2180void 2181icmp6_fasttimo(void) 2182{ 2183 2184 return; 2185} 2186 2187static const char * 2188icmp6_redirect_diag(struct in6_addr *src6, struct in6_addr *dst6, 2189 struct in6_addr *tgt6) 2190{ 2191 static char buf[1024]; 2192 char ip6bufs[INET6_ADDRSTRLEN]; 2193 char ip6bufd[INET6_ADDRSTRLEN]; 2194 char ip6buft[INET6_ADDRSTRLEN]; 2195 snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)", 2196 ip6_sprintf(ip6bufs, src6), ip6_sprintf(ip6bufd, dst6), 2197 ip6_sprintf(ip6buft, tgt6)); 2198 return buf; 2199} 2200 2201void 2202icmp6_redirect_input(struct mbuf *m, int off) 2203{ 2204 struct ifnet *ifp; 2205 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 2206 struct nd_redirect *nd_rd; 2207 int icmp6len = ntohs(ip6->ip6_plen); 2208 char *lladdr = NULL; 2209 int lladdrlen = 0; 2210 u_char *redirhdr = NULL; 2211 int redirhdrlen = 0; 2212 struct rtentry *rt = NULL; 2213 int is_router; 2214 int is_onlink; 2215 struct in6_addr src6 = ip6->ip6_src; 2216 struct in6_addr redtgt6; 2217 struct in6_addr reddst6; 2218 union nd_opts ndopts; 2219 char ip6buf[INET6_ADDRSTRLEN]; 2220 2221 if (!m) 2222 return; 2223 2224 ifp = m->m_pkthdr.rcvif; 2225 2226 if (!ifp) 2227 return; 2228 2229 /* XXX if we are router, we don't update route by icmp6 redirect */ 2230 if (ip6_forwarding) 2231 goto freeit; 2232 if (!icmp6_rediraccept) 2233 goto freeit; 2234 2235#ifndef PULLDOWN_TEST 2236 IP6_EXTHDR_CHECK(m, off, icmp6len,); 2237 nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off); 2238#else 2239 IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len); 2240 if (nd_rd == NULL) { 2241 icmp6stat.icp6s_tooshort++; 2242 return; 2243 } 2244#endif 2245 redtgt6 = nd_rd->nd_rd_target; 2246 reddst6 = nd_rd->nd_rd_dst; 2247 2248 if (in6_setscope(&redtgt6, m->m_pkthdr.rcvif, NULL) || 2249 in6_setscope(&reddst6, m->m_pkthdr.rcvif, NULL)) { 2250 goto freeit; 2251 } 2252 2253 /* validation */ 2254 if (!IN6_IS_ADDR_LINKLOCAL(&src6)) { 2255 nd6log((LOG_ERR, 2256 "ICMP6 redirect sent from %s rejected; " 2257 "must be from linklocal\n", 2258 ip6_sprintf(ip6buf, &src6))); 2259 goto bad; 2260 } 2261 if (ip6->ip6_hlim != 255) { 2262 nd6log((LOG_ERR, 2263 "ICMP6 redirect sent from %s rejected; " 2264 "hlim=%d (must be 255)\n", 2265 ip6_sprintf(ip6buf, &src6), ip6->ip6_hlim)); 2266 goto bad; 2267 } 2268 { 2269 /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */ 2270 struct sockaddr_in6 sin6; 2271 struct in6_addr *gw6; 2272 2273 bzero(&sin6, sizeof(sin6)); 2274 sin6.sin6_family = AF_INET6; 2275 sin6.sin6_len = sizeof(struct sockaddr_in6); 2276 bcopy(&reddst6, &sin6.sin6_addr, sizeof(reddst6)); 2277 rt = rtalloc1((struct sockaddr *)&sin6, 0, 0UL); 2278 if (rt) { 2279 if (rt->rt_gateway == NULL || 2280 rt->rt_gateway->sa_family != AF_INET6) { 2281 nd6log((LOG_ERR, 2282 "ICMP6 redirect rejected; no route " 2283 "with inet6 gateway found for redirect dst: %s\n", 2284 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2285 RTFREE_LOCKED(rt); 2286 goto bad; 2287 } 2288 2289 gw6 = &(((struct sockaddr_in6 *)rt->rt_gateway)->sin6_addr); 2290 if (bcmp(&src6, gw6, sizeof(struct in6_addr)) != 0) { 2291 nd6log((LOG_ERR, 2292 "ICMP6 redirect rejected; " 2293 "not equal to gw-for-src=%s (must be same): " 2294 "%s\n", 2295 ip6_sprintf(ip6buf, gw6), 2296 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2297 RTFREE_LOCKED(rt); 2298 goto bad; 2299 } 2300 } else { 2301 nd6log((LOG_ERR, 2302 "ICMP6 redirect rejected; " 2303 "no route found for redirect dst: %s\n", 2304 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2305 goto bad; 2306 } 2307 RTFREE_LOCKED(rt); 2308 rt = NULL; 2309 } 2310 if (IN6_IS_ADDR_MULTICAST(&reddst6)) { 2311 nd6log((LOG_ERR, 2312 "ICMP6 redirect rejected; " 2313 "redirect dst must be unicast: %s\n", 2314 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2315 goto bad; 2316 } 2317 2318 is_router = is_onlink = 0; 2319 if (IN6_IS_ADDR_LINKLOCAL(&redtgt6)) 2320 is_router = 1; /* router case */ 2321 if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0) 2322 is_onlink = 1; /* on-link destination case */ 2323 if (!is_router && !is_onlink) { 2324 nd6log((LOG_ERR, 2325 "ICMP6 redirect rejected; " 2326 "neither router case nor onlink case: %s\n", 2327 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2328 goto bad; 2329 } 2330 /* validation passed */ 2331 2332 icmp6len -= sizeof(*nd_rd); 2333 nd6_option_init(nd_rd + 1, icmp6len, &ndopts); 2334 if (nd6_options(&ndopts) < 0) { 2335 nd6log((LOG_INFO, "icmp6_redirect_input: " 2336 "invalid ND option, rejected: %s\n", 2337 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2338 /* nd6_options have incremented stats */ 2339 goto freeit; 2340 } 2341 2342 if (ndopts.nd_opts_tgt_lladdr) { 2343 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 2344 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 2345 } 2346 2347 if (ndopts.nd_opts_rh) { 2348 redirhdrlen = ndopts.nd_opts_rh->nd_opt_rh_len; 2349 redirhdr = (u_char *)(ndopts.nd_opts_rh + 1); /* xxx */ 2350 } 2351 2352 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 2353 nd6log((LOG_INFO, 2354 "icmp6_redirect_input: lladdrlen mismatch for %s " 2355 "(if %d, icmp6 packet %d): %s\n", 2356 ip6_sprintf(ip6buf, &redtgt6), 2357 ifp->if_addrlen, lladdrlen - 2, 2358 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2359 goto bad; 2360 } 2361 2362 /* RFC 2461 8.3 */ 2363 nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT, 2364 is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER); 2365 2366 if (!is_onlink) { /* better router case. perform rtredirect. */ 2367 /* perform rtredirect */ 2368 struct sockaddr_in6 sdst; 2369 struct sockaddr_in6 sgw; 2370 struct sockaddr_in6 ssrc; 2371 2372 bzero(&sdst, sizeof(sdst)); 2373 bzero(&sgw, sizeof(sgw)); 2374 bzero(&ssrc, sizeof(ssrc)); 2375 sdst.sin6_family = sgw.sin6_family = ssrc.sin6_family = AF_INET6; 2376 sdst.sin6_len = sgw.sin6_len = ssrc.sin6_len = 2377 sizeof(struct sockaddr_in6); 2378 bcopy(&redtgt6, &sgw.sin6_addr, sizeof(struct in6_addr)); 2379 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr)); 2380 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr)); 2381 rtredirect((struct sockaddr *)&sdst, (struct sockaddr *)&sgw, 2382 (struct sockaddr *)NULL, RTF_GATEWAY | RTF_HOST, 2383 (struct sockaddr *)&ssrc); 2384 } 2385 /* finally update cached route in each socket via pfctlinput */ 2386 { 2387 struct sockaddr_in6 sdst; 2388 2389 bzero(&sdst, sizeof(sdst)); 2390 sdst.sin6_family = AF_INET6; 2391 sdst.sin6_len = sizeof(struct sockaddr_in6); 2392 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr)); 2393 pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst); 2394#ifdef IPSEC 2395 key_sa_routechange((struct sockaddr *)&sdst); 2396#endif /* IPSEC */ 2397 } 2398 2399 freeit: 2400 m_freem(m); 2401 return; 2402 2403 bad: 2404 icmp6stat.icp6s_badredirect++; 2405 m_freem(m); 2406} 2407 2408void 2409icmp6_redirect_output(struct mbuf *m0, struct rtentry *rt) 2410{ 2411 struct ifnet *ifp; /* my outgoing interface */ 2412 struct in6_addr *ifp_ll6; 2413 struct in6_addr *router_ll6; 2414 struct ip6_hdr *sip6; /* m0 as struct ip6_hdr */ 2415 struct mbuf *m = NULL; /* newly allocated one */ 2416 struct ip6_hdr *ip6; /* m as struct ip6_hdr */ 2417 struct nd_redirect *nd_rd; 2418 size_t maxlen; 2419 u_char *p; 2420 struct ifnet *outif = NULL; 2421 struct sockaddr_in6 src_sa; 2422 2423 icmp6_errcount(&icmp6stat.icp6s_outerrhist, ND_REDIRECT, 0); 2424 2425 /* if we are not router, we don't send icmp6 redirect */ 2426 if (!ip6_forwarding) 2427 goto fail; 2428 2429 /* sanity check */ 2430 if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp)) 2431 goto fail; 2432 2433 /* 2434 * Address check: 2435 * the source address must identify a neighbor, and 2436 * the destination address must not be a multicast address 2437 * [RFC 2461, sec 8.2] 2438 */ 2439 sip6 = mtod(m0, struct ip6_hdr *); 2440 bzero(&src_sa, sizeof(src_sa)); 2441 src_sa.sin6_family = AF_INET6; 2442 src_sa.sin6_len = sizeof(src_sa); 2443 src_sa.sin6_addr = sip6->ip6_src; 2444 if (nd6_is_addr_neighbor(&src_sa, ifp) == 0) 2445 goto fail; 2446 if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst)) 2447 goto fail; /* what should we do here? */ 2448 2449 /* rate limit */ 2450 if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0)) 2451 goto fail; 2452 2453 /* 2454 * Since we are going to append up to 1280 bytes (= IPV6_MMTU), 2455 * we almost always ask for an mbuf cluster for simplicity. 2456 * (MHLEN < IPV6_MMTU is almost always true) 2457 */ 2458#if IPV6_MMTU >= MCLBYTES 2459# error assumption failed about IPV6_MMTU and MCLBYTES 2460#endif 2461 MGETHDR(m, M_DONTWAIT, MT_HEADER); 2462 if (m && IPV6_MMTU >= MHLEN) 2463 MCLGET(m, M_DONTWAIT); 2464 if (!m) 2465 goto fail; 2466 m->m_pkthdr.rcvif = NULL; 2467 m->m_len = 0; 2468 maxlen = M_TRAILINGSPACE(m); 2469 maxlen = min(IPV6_MMTU, maxlen); 2470 /* just for safety */ 2471 if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) + 2472 ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) { 2473 goto fail; 2474 } 2475 2476 { 2477 /* get ip6 linklocal address for ifp(my outgoing interface). */ 2478 struct in6_ifaddr *ia; 2479 if ((ia = in6ifa_ifpforlinklocal(ifp, 2480 IN6_IFF_NOTREADY| 2481 IN6_IFF_ANYCAST)) == NULL) 2482 goto fail; 2483 ifp_ll6 = &ia->ia_addr.sin6_addr; 2484 } 2485 2486 /* get ip6 linklocal address for the router. */ 2487 if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) { 2488 struct sockaddr_in6 *sin6; 2489 sin6 = (struct sockaddr_in6 *)rt->rt_gateway; 2490 router_ll6 = &sin6->sin6_addr; 2491 if (!IN6_IS_ADDR_LINKLOCAL(router_ll6)) 2492 router_ll6 = (struct in6_addr *)NULL; 2493 } else 2494 router_ll6 = (struct in6_addr *)NULL; 2495 2496 /* ip6 */ 2497 ip6 = mtod(m, struct ip6_hdr *); 2498 ip6->ip6_flow = 0; 2499 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2500 ip6->ip6_vfc |= IPV6_VERSION; 2501 /* ip6->ip6_plen will be set later */ 2502 ip6->ip6_nxt = IPPROTO_ICMPV6; 2503 ip6->ip6_hlim = 255; 2504 /* ip6->ip6_src must be linklocal addr for my outgoing if. */ 2505 bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr)); 2506 bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr)); 2507 2508 /* ND Redirect */ 2509 nd_rd = (struct nd_redirect *)(ip6 + 1); 2510 nd_rd->nd_rd_type = ND_REDIRECT; 2511 nd_rd->nd_rd_code = 0; 2512 nd_rd->nd_rd_reserved = 0; 2513 if (rt->rt_flags & RTF_GATEWAY) { 2514 /* 2515 * nd_rd->nd_rd_target must be a link-local address in 2516 * better router cases. 2517 */ 2518 if (!router_ll6) 2519 goto fail; 2520 bcopy(router_ll6, &nd_rd->nd_rd_target, 2521 sizeof(nd_rd->nd_rd_target)); 2522 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2523 sizeof(nd_rd->nd_rd_dst)); 2524 } else { 2525 /* make sure redtgt == reddst */ 2526 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target, 2527 sizeof(nd_rd->nd_rd_target)); 2528 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2529 sizeof(nd_rd->nd_rd_dst)); 2530 } 2531 2532 p = (u_char *)(nd_rd + 1); 2533 2534 if (!router_ll6) 2535 goto nolladdropt; 2536 2537 { 2538 /* target lladdr option */ 2539 struct rtentry *rt_router = NULL; 2540 int len; 2541 struct sockaddr_dl *sdl; 2542 struct nd_opt_hdr *nd_opt; 2543 char *lladdr; 2544 2545 rt_router = nd6_lookup(router_ll6, 0, ifp); 2546 if (!rt_router) 2547 goto nolladdropt; 2548 len = sizeof(*nd_opt) + ifp->if_addrlen; 2549 len = (len + 7) & ~7; /* round by 8 */ 2550 /* safety check */ 2551 if (len + (p - (u_char *)ip6) > maxlen) 2552 goto nolladdropt; 2553 if (!(rt_router->rt_flags & RTF_GATEWAY) && 2554 (rt_router->rt_flags & RTF_LLINFO) && 2555 (rt_router->rt_gateway->sa_family == AF_LINK) && 2556 (sdl = (struct sockaddr_dl *)rt_router->rt_gateway) && 2557 sdl->sdl_alen) { 2558 nd_opt = (struct nd_opt_hdr *)p; 2559 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 2560 nd_opt->nd_opt_len = len >> 3; 2561 lladdr = (char *)(nd_opt + 1); 2562 bcopy(LLADDR(sdl), lladdr, ifp->if_addrlen); 2563 p += len; 2564 } 2565 } 2566nolladdropt:; 2567 2568 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2569 2570 /* just to be safe */ 2571#ifdef M_DECRYPTED /*not openbsd*/ 2572 if (m0->m_flags & M_DECRYPTED) 2573 goto noredhdropt; 2574#endif 2575 if (p - (u_char *)ip6 > maxlen) 2576 goto noredhdropt; 2577 2578 { 2579 /* redirected header option */ 2580 int len; 2581 struct nd_opt_rd_hdr *nd_opt_rh; 2582 2583 /* 2584 * compute the maximum size for icmp6 redirect header option. 2585 * XXX room for auth header? 2586 */ 2587 len = maxlen - (p - (u_char *)ip6); 2588 len &= ~7; 2589 2590 /* This is just for simplicity. */ 2591 if (m0->m_pkthdr.len != m0->m_len) { 2592 if (m0->m_next) { 2593 m_freem(m0->m_next); 2594 m0->m_next = NULL; 2595 } 2596 m0->m_pkthdr.len = m0->m_len; 2597 } 2598 2599 /* 2600 * Redirected header option spec (RFC2461 4.6.3) talks nothing 2601 * about padding/truncate rule for the original IP packet. 2602 * From the discussion on IPv6imp in Feb 1999, 2603 * the consensus was: 2604 * - "attach as much as possible" is the goal 2605 * - pad if not aligned (original size can be guessed by 2606 * original ip6 header) 2607 * Following code adds the padding if it is simple enough, 2608 * and truncates if not. 2609 */ 2610 if (m0->m_next || m0->m_pkthdr.len != m0->m_len) 2611 panic("assumption failed in %s:%d", __FILE__, 2612 __LINE__); 2613 2614 if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) { 2615 /* not enough room, truncate */ 2616 m0->m_pkthdr.len = m0->m_len = len - 2617 sizeof(*nd_opt_rh); 2618 } else { 2619 /* enough room, pad or truncate */ 2620 size_t extra; 2621 2622 extra = m0->m_pkthdr.len % 8; 2623 if (extra) { 2624 /* pad if easy enough, truncate if not */ 2625 if (8 - extra <= M_TRAILINGSPACE(m0)) { 2626 /* pad */ 2627 m0->m_len += (8 - extra); 2628 m0->m_pkthdr.len += (8 - extra); 2629 } else { 2630 /* truncate */ 2631 m0->m_pkthdr.len -= extra; 2632 m0->m_len -= extra; 2633 } 2634 } 2635 len = m0->m_pkthdr.len + sizeof(*nd_opt_rh); 2636 m0->m_pkthdr.len = m0->m_len = len - 2637 sizeof(*nd_opt_rh); 2638 } 2639 2640 nd_opt_rh = (struct nd_opt_rd_hdr *)p; 2641 bzero(nd_opt_rh, sizeof(*nd_opt_rh)); 2642 nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER; 2643 nd_opt_rh->nd_opt_rh_len = len >> 3; 2644 p += sizeof(*nd_opt_rh); 2645 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2646 2647 /* connect m0 to m */ 2648 m_tag_delete_chain(m0, NULL); 2649 m0->m_flags &= ~M_PKTHDR; 2650 m->m_next = m0; 2651 m->m_pkthdr.len = m->m_len + m0->m_len; 2652 m0 = NULL; 2653 } 2654noredhdropt:; 2655 if (m0) { 2656 m_freem(m0); 2657 m0 = NULL; 2658 } 2659 2660 /* XXX: clear embedded link IDs in the inner header */ 2661 in6_clearscope(&sip6->ip6_src); 2662 in6_clearscope(&sip6->ip6_dst); 2663 in6_clearscope(&nd_rd->nd_rd_target); 2664 in6_clearscope(&nd_rd->nd_rd_dst); 2665 2666 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr)); 2667 2668 nd_rd->nd_rd_cksum = 0; 2669 nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2670 sizeof(*ip6), ntohs(ip6->ip6_plen)); 2671 2672 /* send the packet to outside... */ 2673 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2674 if (outif) { 2675 icmp6_ifstat_inc(outif, ifs6_out_msg); 2676 icmp6_ifstat_inc(outif, ifs6_out_redirect); 2677 } 2678 icmp6stat.icp6s_outhist[ND_REDIRECT]++; 2679 2680 return; 2681 2682fail: 2683 if (m) 2684 m_freem(m); 2685 if (m0) 2686 m_freem(m0); 2687} 2688 2689/* 2690 * ICMPv6 socket option processing. 2691 */ 2692int 2693icmp6_ctloutput(struct socket *so, struct sockopt *sopt) 2694{ 2695 int error = 0; 2696 int optlen; 2697 struct inpcb *inp = sotoinpcb(so); 2698 int level, op, optname; 2699 2700 if (sopt) { 2701 level = sopt->sopt_level; 2702 op = sopt->sopt_dir; 2703 optname = sopt->sopt_name; 2704 optlen = sopt->sopt_valsize; 2705 } else 2706 level = op = optname = optlen = 0; 2707 2708 if (level != IPPROTO_ICMPV6) { 2709 return EINVAL; 2710 } 2711 2712 switch (op) { 2713 case PRCO_SETOPT: 2714 switch (optname) { 2715 case ICMP6_FILTER: 2716 { 2717 struct icmp6_filter *p; 2718 2719 if (optlen != sizeof(*p)) { 2720 error = EMSGSIZE; 2721 break; 2722 } 2723 if (inp->in6p_icmp6filt == NULL) { 2724 error = EINVAL; 2725 break; 2726 } 2727 error = sooptcopyin(sopt, inp->in6p_icmp6filt, optlen, 2728 optlen); 2729 break; 2730 } 2731 2732 default: 2733 error = ENOPROTOOPT; 2734 break; 2735 } 2736 break; 2737 2738 case PRCO_GETOPT: 2739 switch (optname) { 2740 case ICMP6_FILTER: 2741 { 2742 if (inp->in6p_icmp6filt == NULL) { 2743 error = EINVAL; 2744 break; 2745 } 2746 error = sooptcopyout(sopt, inp->in6p_icmp6filt, 2747 sizeof(struct icmp6_filter)); 2748 break; 2749 } 2750 2751 default: 2752 error = ENOPROTOOPT; 2753 break; 2754 } 2755 break; 2756 } 2757 2758 return (error); 2759} 2760 2761/* 2762 * Perform rate limit check. 2763 * Returns 0 if it is okay to send the icmp6 packet. 2764 * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate 2765 * limitation. 2766 * 2767 * XXX per-destination/type check necessary? 2768 * 2769 * dst - not used at this moment 2770 * type - not used at this moment 2771 * code - not used at this moment 2772 */ 2773static int 2774icmp6_ratelimit(const struct in6_addr *dst, const int type, 2775 const int code) 2776{ 2777 int ret; 2778 2779 ret = 0; /* okay to send */ 2780 2781 /* PPS limit */ 2782 if (!ppsratecheck(&icmp6errppslim_last, &icmp6errpps_count, 2783 icmp6errppslim)) { 2784 /* The packet is subject to rate limit */ 2785 ret++; 2786 } 2787 2788 return ret; 2789} 2790