icmp6.c revision 194777
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 194777 2009-06-23 22:08:55Z bz $"); 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/jail.h> 73#include <sys/kernel.h> 74#include <sys/lock.h> 75#include <sys/malloc.h> 76#include <sys/mbuf.h> 77#include <sys/protosw.h> 78#include <sys/signalvar.h> 79#include <sys/socket.h> 80#include <sys/socketvar.h> 81#include <sys/sx.h> 82#include <sys/syslog.h> 83#include <sys/systm.h> 84#include <sys/time.h> 85#include <sys/vimage.h> 86 87#include <net/if.h> 88#include <net/if_dl.h> 89#include <net/if_llatbl.h> 90#include <net/if_types.h> 91#include <net/route.h> 92#include <net/vnet.h> 93 94#include <netinet/in.h> 95#include <netinet/in_pcb.h> 96#include <netinet/in_var.h> 97#include <netinet/ip6.h> 98#include <netinet/icmp6.h> 99#include <netinet/tcp_var.h> 100#include <netinet/vinet.h> 101 102#include <netinet6/in6_ifattach.h> 103#include <netinet6/in6_pcb.h> 104#include <netinet6/ip6protosw.h> 105#include <netinet6/ip6_var.h> 106#include <netinet6/scope6_var.h> 107#include <netinet6/mld6_var.h> 108#include <netinet6/nd6.h> 109#include <netinet6/vinet6.h> 110 111#ifdef IPSEC 112#include <netipsec/ipsec.h> 113#include <netipsec/key.h> 114#endif 115 116extern struct domain inet6domain; 117 118#ifdef VIMAGE_GLOBALS 119extern struct inpcbinfo ripcbinfo; 120extern struct inpcbhead ripcb; 121extern int icmp6errppslim; 122extern int icmp6_nodeinfo; 123 124struct icmp6stat icmp6stat; 125static int icmp6errpps_count; 126static struct timeval icmp6errppslim_last; 127#endif 128 129static void icmp6_errcount(struct icmp6errstat *, int, int); 130static int icmp6_rip6_input(struct mbuf **, int); 131static int icmp6_ratelimit(const struct in6_addr *, const int, const int); 132static const char *icmp6_redirect_diag __P((struct in6_addr *, 133 struct in6_addr *, struct in6_addr *)); 134static struct mbuf *ni6_input(struct mbuf *, int); 135static struct mbuf *ni6_nametodns(const char *, int, int); 136static int ni6_dnsmatch(const char *, int, const char *, int); 137static int ni6_addrs __P((struct icmp6_nodeinfo *, struct mbuf *, 138 struct ifnet **, struct in6_addr *)); 139static int ni6_store_addrs __P((struct icmp6_nodeinfo *, struct icmp6_nodeinfo *, 140 struct ifnet *, int)); 141static int icmp6_notify_error(struct mbuf **, int, int, int); 142 143 144void 145icmp6_init(void) 146{ 147 INIT_VNET_INET6(curvnet); 148 149 V_icmp6errpps_count = 0; 150} 151 152static void 153icmp6_errcount(struct icmp6errstat *stat, int type, int code) 154{ 155 switch (type) { 156 case ICMP6_DST_UNREACH: 157 switch (code) { 158 case ICMP6_DST_UNREACH_NOROUTE: 159 stat->icp6errs_dst_unreach_noroute++; 160 return; 161 case ICMP6_DST_UNREACH_ADMIN: 162 stat->icp6errs_dst_unreach_admin++; 163 return; 164 case ICMP6_DST_UNREACH_BEYONDSCOPE: 165 stat->icp6errs_dst_unreach_beyondscope++; 166 return; 167 case ICMP6_DST_UNREACH_ADDR: 168 stat->icp6errs_dst_unreach_addr++; 169 return; 170 case ICMP6_DST_UNREACH_NOPORT: 171 stat->icp6errs_dst_unreach_noport++; 172 return; 173 } 174 break; 175 case ICMP6_PACKET_TOO_BIG: 176 stat->icp6errs_packet_too_big++; 177 return; 178 case ICMP6_TIME_EXCEEDED: 179 switch (code) { 180 case ICMP6_TIME_EXCEED_TRANSIT: 181 stat->icp6errs_time_exceed_transit++; 182 return; 183 case ICMP6_TIME_EXCEED_REASSEMBLY: 184 stat->icp6errs_time_exceed_reassembly++; 185 return; 186 } 187 break; 188 case ICMP6_PARAM_PROB: 189 switch (code) { 190 case ICMP6_PARAMPROB_HEADER: 191 stat->icp6errs_paramprob_header++; 192 return; 193 case ICMP6_PARAMPROB_NEXTHEADER: 194 stat->icp6errs_paramprob_nextheader++; 195 return; 196 case ICMP6_PARAMPROB_OPTION: 197 stat->icp6errs_paramprob_option++; 198 return; 199 } 200 break; 201 case ND_REDIRECT: 202 stat->icp6errs_redirect++; 203 return; 204 } 205 stat->icp6errs_unknown++; 206} 207 208/* 209 * A wrapper function for icmp6_error() necessary when the erroneous packet 210 * may not contain enough scope zone information. 211 */ 212void 213icmp6_error2(struct mbuf *m, int type, int code, int param, 214 struct ifnet *ifp) 215{ 216 INIT_VNET_INET6(curvnet); 217 struct ip6_hdr *ip6; 218 219 if (ifp == NULL) 220 return; 221 222#ifndef PULLDOWN_TEST 223 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), ); 224#else 225 if (m->m_len < sizeof(struct ip6_hdr)) { 226 m = m_pullup(m, sizeof(struct ip6_hdr)); 227 if (m == NULL) 228 return; 229 } 230#endif 231 232 ip6 = mtod(m, struct ip6_hdr *); 233 234 if (in6_setscope(&ip6->ip6_src, ifp, NULL) != 0) 235 return; 236 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0) 237 return; 238 239 icmp6_error(m, type, code, param); 240} 241 242/* 243 * Generate an error packet of type error in response to bad IP6 packet. 244 */ 245void 246icmp6_error(struct mbuf *m, int type, int code, int param) 247{ 248 INIT_VNET_INET6(curvnet); 249 struct ip6_hdr *oip6, *nip6; 250 struct icmp6_hdr *icmp6; 251 u_int preplen; 252 int off; 253 int nxt; 254 255 ICMP6STAT_INC(icp6s_error); 256 257 /* count per-type-code statistics */ 258 icmp6_errcount(&V_icmp6stat.icp6s_outerrhist, type, code); 259 260#ifdef M_DECRYPTED /*not openbsd*/ 261 if (m->m_flags & M_DECRYPTED) { 262 ICMP6STAT_INC(icp6s_canterror); 263 goto freeit; 264 } 265#endif 266 267#ifndef PULLDOWN_TEST 268 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), ); 269#else 270 if (m->m_len < sizeof(struct ip6_hdr)) { 271 m = m_pullup(m, sizeof(struct ip6_hdr)); 272 if (m == NULL) 273 return; 274 } 275#endif 276 oip6 = mtod(m, struct ip6_hdr *); 277 278 /* 279 * If the destination address of the erroneous packet is a multicast 280 * address, or the packet was sent using link-layer multicast, 281 * we should basically suppress sending an error (RFC 2463, Section 282 * 2.4). 283 * We have two exceptions (the item e.2 in that section): 284 * - the Pakcet Too Big message can be sent for path MTU discovery. 285 * - the Parameter Problem Message that can be allowed an icmp6 error 286 * in the option type field. This check has been done in 287 * ip6_unknown_opt(), so we can just check the type and code. 288 */ 289 if ((m->m_flags & (M_BCAST|M_MCAST) || 290 IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) && 291 (type != ICMP6_PACKET_TOO_BIG && 292 (type != ICMP6_PARAM_PROB || 293 code != ICMP6_PARAMPROB_OPTION))) 294 goto freeit; 295 296 /* 297 * RFC 2463, 2.4 (e.5): source address check. 298 * XXX: the case of anycast source? 299 */ 300 if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) || 301 IN6_IS_ADDR_MULTICAST(&oip6->ip6_src)) 302 goto freeit; 303 304 /* 305 * If we are about to send ICMPv6 against ICMPv6 error/redirect, 306 * don't do it. 307 */ 308 nxt = -1; 309 off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt); 310 if (off >= 0 && nxt == IPPROTO_ICMPV6) { 311 struct icmp6_hdr *icp; 312 313#ifndef PULLDOWN_TEST 314 IP6_EXTHDR_CHECK(m, 0, off + sizeof(struct icmp6_hdr), ); 315 icp = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 316#else 317 IP6_EXTHDR_GET(icp, struct icmp6_hdr *, m, off, 318 sizeof(*icp)); 319 if (icp == NULL) { 320 ICMP6STAT_INC(icp6s_tooshort); 321 return; 322 } 323#endif 324 if (icp->icmp6_type < ICMP6_ECHO_REQUEST || 325 icp->icmp6_type == ND_REDIRECT) { 326 /* 327 * ICMPv6 error 328 * Special case: for redirect (which is 329 * informational) we must not send icmp6 error. 330 */ 331 ICMP6STAT_INC(icp6s_canterror); 332 goto freeit; 333 } else { 334 /* ICMPv6 informational - send the error */ 335 } 336 } else { 337 /* non-ICMPv6 - send the error */ 338 } 339 340 oip6 = mtod(m, struct ip6_hdr *); /* adjust pointer */ 341 342 /* Finally, do rate limitation check. */ 343 if (icmp6_ratelimit(&oip6->ip6_src, type, code)) { 344 ICMP6STAT_INC(icp6s_toofreq); 345 goto freeit; 346 } 347 348 /* 349 * OK, ICMP6 can be generated. 350 */ 351 352 if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN) 353 m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len); 354 355 preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 356 M_PREPEND(m, preplen, M_DONTWAIT); 357 if (m && m->m_len < preplen) 358 m = m_pullup(m, preplen); 359 if (m == NULL) { 360 nd6log((LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__)); 361 return; 362 } 363 364 nip6 = mtod(m, struct ip6_hdr *); 365 nip6->ip6_src = oip6->ip6_src; 366 nip6->ip6_dst = oip6->ip6_dst; 367 368 in6_clearscope(&oip6->ip6_src); 369 in6_clearscope(&oip6->ip6_dst); 370 371 icmp6 = (struct icmp6_hdr *)(nip6 + 1); 372 icmp6->icmp6_type = type; 373 icmp6->icmp6_code = code; 374 icmp6->icmp6_pptr = htonl((u_int32_t)param); 375 376 /* 377 * icmp6_reflect() is designed to be in the input path. 378 * icmp6_error() can be called from both input and output path, 379 * and if we are in output path rcvif could contain bogus value. 380 * clear m->m_pkthdr.rcvif for safety, we should have enough scope 381 * information in ip header (nip6). 382 */ 383 m->m_pkthdr.rcvif = NULL; 384 385 ICMP6STAT_INC(icp6s_outhist[type]); 386 icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */ 387 388 return; 389 390 freeit: 391 /* 392 * If we can't tell whether or not we can generate ICMP6, free it. 393 */ 394 m_freem(m); 395} 396 397/* 398 * Process a received ICMP6 message. 399 */ 400int 401icmp6_input(struct mbuf **mp, int *offp, int proto) 402{ 403 INIT_VNET_INET6(curvnet); 404 struct mbuf *m = *mp, *n; 405 struct ifnet *ifp; 406 struct ip6_hdr *ip6, *nip6; 407 struct icmp6_hdr *icmp6, *nicmp6; 408 int off = *offp; 409 int icmp6len = m->m_pkthdr.len - *offp; 410 int code, sum, noff; 411 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 412 413 ifp = m->m_pkthdr.rcvif; 414 415#ifndef PULLDOWN_TEST 416 IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_hdr), IPPROTO_DONE); 417 /* m might change if M_LOOP. So, call mtod after this */ 418#endif 419 420 /* 421 * Locate icmp6 structure in mbuf, and check 422 * that not corrupted and of at least minimum length 423 */ 424 425 ip6 = mtod(m, struct ip6_hdr *); 426 if (icmp6len < sizeof(struct icmp6_hdr)) { 427 ICMP6STAT_INC(icp6s_tooshort); 428 goto freeit; 429 } 430 431 /* 432 * Check multicast group membership. 433 * Note: SSM filters are not applied for ICMPv6 traffic. 434 */ 435 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 436 struct in6_multi *inm; 437 438 inm = in6m_lookup(ifp, &ip6->ip6_dst); 439 if (inm == NULL) { 440 IP6STAT_INC(ip6s_notmember); 441 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 442 goto freeit; 443 } 444 } 445 446 /* 447 * calculate the checksum 448 */ 449#ifndef PULLDOWN_TEST 450 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off); 451#else 452 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6)); 453 if (icmp6 == NULL) { 454 ICMP6STAT_INC(icp6s_tooshort); 455 return IPPROTO_DONE; 456 } 457#endif 458 code = icmp6->icmp6_code; 459 460 if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) { 461 nd6log((LOG_ERR, 462 "ICMP6 checksum error(%d|%x) %s\n", 463 icmp6->icmp6_type, sum, 464 ip6_sprintf(ip6bufs, &ip6->ip6_src))); 465 ICMP6STAT_INC(icp6s_checksum); 466 goto freeit; 467 } 468 469 if (faithprefix_p != NULL && (*faithprefix_p)(&ip6->ip6_dst)) { 470 /* 471 * Deliver very specific ICMP6 type only. 472 * This is important to deliver TOOBIG. Otherwise PMTUD 473 * will not work. 474 */ 475 switch (icmp6->icmp6_type) { 476 case ICMP6_DST_UNREACH: 477 case ICMP6_PACKET_TOO_BIG: 478 case ICMP6_TIME_EXCEEDED: 479 break; 480 default: 481 goto freeit; 482 } 483 } 484 485 ICMP6STAT_INC(icp6s_inhist[icmp6->icmp6_type]); 486 icmp6_ifstat_inc(ifp, ifs6_in_msg); 487 if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK) 488 icmp6_ifstat_inc(ifp, ifs6_in_error); 489 490 switch (icmp6->icmp6_type) { 491 case ICMP6_DST_UNREACH: 492 icmp6_ifstat_inc(ifp, ifs6_in_dstunreach); 493 switch (code) { 494 case ICMP6_DST_UNREACH_NOROUTE: 495 code = PRC_UNREACH_NET; 496 break; 497 case ICMP6_DST_UNREACH_ADMIN: 498 icmp6_ifstat_inc(ifp, ifs6_in_adminprohib); 499 code = PRC_UNREACH_PROTOCOL; /* is this a good code? */ 500 break; 501 case ICMP6_DST_UNREACH_ADDR: 502 code = PRC_HOSTDEAD; 503 break; 504 case ICMP6_DST_UNREACH_BEYONDSCOPE: 505 /* I mean "source address was incorrect." */ 506 code = PRC_PARAMPROB; 507 break; 508 case ICMP6_DST_UNREACH_NOPORT: 509 code = PRC_UNREACH_PORT; 510 break; 511 default: 512 goto badcode; 513 } 514 goto deliver; 515 break; 516 517 case ICMP6_PACKET_TOO_BIG: 518 icmp6_ifstat_inc(ifp, ifs6_in_pkttoobig); 519 520 /* validation is made in icmp6_mtudisc_update */ 521 522 code = PRC_MSGSIZE; 523 524 /* 525 * Updating the path MTU will be done after examining 526 * intermediate extension headers. 527 */ 528 goto deliver; 529 break; 530 531 case ICMP6_TIME_EXCEEDED: 532 icmp6_ifstat_inc(ifp, ifs6_in_timeexceed); 533 switch (code) { 534 case ICMP6_TIME_EXCEED_TRANSIT: 535 code = PRC_TIMXCEED_INTRANS; 536 break; 537 case ICMP6_TIME_EXCEED_REASSEMBLY: 538 code = PRC_TIMXCEED_REASS; 539 break; 540 default: 541 goto badcode; 542 } 543 goto deliver; 544 break; 545 546 case ICMP6_PARAM_PROB: 547 icmp6_ifstat_inc(ifp, ifs6_in_paramprob); 548 switch (code) { 549 case ICMP6_PARAMPROB_NEXTHEADER: 550 code = PRC_UNREACH_PROTOCOL; 551 break; 552 case ICMP6_PARAMPROB_HEADER: 553 case ICMP6_PARAMPROB_OPTION: 554 code = PRC_PARAMPROB; 555 break; 556 default: 557 goto badcode; 558 } 559 goto deliver; 560 break; 561 562 case ICMP6_ECHO_REQUEST: 563 icmp6_ifstat_inc(ifp, ifs6_in_echo); 564 if (code != 0) 565 goto badcode; 566 if ((n = m_copy(m, 0, M_COPYALL)) == NULL) { 567 /* Give up remote */ 568 break; 569 } 570 if ((n->m_flags & M_EXT) != 0 571 || n->m_len < off + sizeof(struct icmp6_hdr)) { 572 struct mbuf *n0 = n; 573 const int maxlen = sizeof(*nip6) + sizeof(*nicmp6); 574 int n0len; 575 576 MGETHDR(n, M_DONTWAIT, n0->m_type); 577 n0len = n0->m_pkthdr.len; /* save for use below */ 578 if (n) 579 M_MOVE_PKTHDR(n, n0); 580 if (n && maxlen >= MHLEN) { 581 MCLGET(n, M_DONTWAIT); 582 if ((n->m_flags & M_EXT) == 0) { 583 m_free(n); 584 n = NULL; 585 } 586 } 587 if (n == NULL) { 588 /* Give up remote */ 589 m_freem(n0); 590 break; 591 } 592 /* 593 * Copy IPv6 and ICMPv6 only. 594 */ 595 nip6 = mtod(n, struct ip6_hdr *); 596 bcopy(ip6, nip6, sizeof(struct ip6_hdr)); 597 nicmp6 = (struct icmp6_hdr *)(nip6 + 1); 598 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr)); 599 noff = sizeof(struct ip6_hdr); 600 /* new mbuf contains only ipv6+icmpv6 headers */ 601 n->m_len = noff + sizeof(struct icmp6_hdr); 602 /* 603 * Adjust mbuf. ip6_plen will be adjusted in 604 * ip6_output(). 605 */ 606 m_adj(n0, off + sizeof(struct icmp6_hdr)); 607 /* recalculate complete packet size */ 608 n->m_pkthdr.len = n0len + (noff - off); 609 n->m_next = n0; 610 } else { 611 nip6 = mtod(n, struct ip6_hdr *); 612 IP6_EXTHDR_GET(nicmp6, struct icmp6_hdr *, n, off, 613 sizeof(*nicmp6)); 614 noff = off; 615 } 616 nicmp6->icmp6_type = ICMP6_ECHO_REPLY; 617 nicmp6->icmp6_code = 0; 618 if (n) { 619 ICMP6STAT_INC(icp6s_reflect); 620 ICMP6STAT_INC(icp6s_outhist[ICMP6_ECHO_REPLY]); 621 icmp6_reflect(n, noff); 622 } 623 break; 624 625 case ICMP6_ECHO_REPLY: 626 icmp6_ifstat_inc(ifp, ifs6_in_echoreply); 627 if (code != 0) 628 goto badcode; 629 break; 630 631 case MLD_LISTENER_QUERY: 632 case MLD_LISTENER_REPORT: 633 case MLD_LISTENER_DONE: 634 case MLDV2_LISTENER_REPORT: 635 /* 636 * Drop MLD traffic which is not link-local, has a hop limit 637 * of greater than 1 hop, or which does not have the 638 * IPv6 HBH Router Alert option. 639 * As IPv6 HBH options are stripped in ip6_input() we must 640 * check an mbuf header flag. 641 * XXX Should we also sanity check that these messages 642 * were directed to a link-local multicast prefix? 643 */ 644 if ((ip6->ip6_hlim != 1) || (m->m_flags & M_RTALERT_MLD) == 0) 645 goto freeit; 646 if (mld_input(m, off, icmp6len) != 0) 647 return (IPPROTO_DONE); 648 /* m stays. */ 649 break; 650 651 case ICMP6_WRUREQUEST: /* ICMP6_FQDN_QUERY */ 652 { 653 enum { WRU, FQDN } mode; 654 655 if (!V_icmp6_nodeinfo) 656 break; 657 658 if (icmp6len == sizeof(struct icmp6_hdr) + 4) 659 mode = WRU; 660 else if (icmp6len >= sizeof(struct icmp6_nodeinfo)) 661 mode = FQDN; 662 else 663 goto badlen; 664 665 if (mode == FQDN) { 666#ifndef PULLDOWN_TEST 667 IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_nodeinfo), 668 IPPROTO_DONE); 669#endif 670 n = m_copy(m, 0, M_COPYALL); 671 if (n) 672 n = ni6_input(n, off); 673 /* XXX meaningless if n == NULL */ 674 noff = sizeof(struct ip6_hdr); 675 } else { 676 struct prison *pr; 677 u_char *p; 678 int maxlen, maxhlen, hlen; 679 680 /* 681 * XXX: this combination of flags is pointless, 682 * but should we keep this for compatibility? 683 */ 684 if ((V_icmp6_nodeinfo & 5) != 5) 685 break; 686 687 if (code != 0) 688 goto badcode; 689 maxlen = sizeof(*nip6) + sizeof(*nicmp6) + 4; 690 if (maxlen >= MCLBYTES) { 691 /* Give up remote */ 692 break; 693 } 694 MGETHDR(n, M_DONTWAIT, m->m_type); 695 if (n && maxlen > MHLEN) { 696 MCLGET(n, M_DONTWAIT); 697 if ((n->m_flags & M_EXT) == 0) { 698 m_free(n); 699 n = NULL; 700 } 701 } 702 if (n && !m_dup_pkthdr(n, m, M_DONTWAIT)) { 703 /* 704 * Previous code did a blind M_COPY_PKTHDR 705 * and said "just for rcvif". If true, then 706 * we could tolerate the dup failing (due to 707 * the deep copy of the tag chain). For now 708 * be conservative and just fail. 709 */ 710 m_free(n); 711 n = NULL; 712 } 713 if (n == NULL) { 714 /* Give up remote */ 715 break; 716 } 717 n->m_pkthdr.rcvif = NULL; 718 n->m_len = 0; 719 maxhlen = M_TRAILINGSPACE(n) - maxlen; 720 pr = curthread->td_ucred->cr_prison; 721 mtx_lock(&pr->pr_mtx); 722 hlen = strlen(pr->pr_hostname); 723 if (maxhlen > hlen) 724 maxhlen = hlen; 725 /* 726 * Copy IPv6 and ICMPv6 only. 727 */ 728 nip6 = mtod(n, struct ip6_hdr *); 729 bcopy(ip6, nip6, sizeof(struct ip6_hdr)); 730 nicmp6 = (struct icmp6_hdr *)(nip6 + 1); 731 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr)); 732 p = (u_char *)(nicmp6 + 1); 733 bzero(p, 4); 734 /* meaningless TTL */ 735 bcopy(pr->pr_hostname, p + 4, maxhlen); 736 mtx_unlock(&pr->pr_mtx); 737 noff = sizeof(struct ip6_hdr); 738 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + 739 sizeof(struct icmp6_hdr) + 4 + maxhlen; 740 nicmp6->icmp6_type = ICMP6_WRUREPLY; 741 nicmp6->icmp6_code = 0; 742 } 743 if (n) { 744 ICMP6STAT_INC(icp6s_reflect); 745 ICMP6STAT_INC(icp6s_outhist[ICMP6_WRUREPLY]); 746 icmp6_reflect(n, noff); 747 } 748 break; 749 } 750 751 case ICMP6_WRUREPLY: 752 if (code != 0) 753 goto badcode; 754 break; 755 756 case ND_ROUTER_SOLICIT: 757 icmp6_ifstat_inc(ifp, ifs6_in_routersolicit); 758 if (code != 0) 759 goto badcode; 760 if (icmp6len < sizeof(struct nd_router_solicit)) 761 goto badlen; 762 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 763 /* give up local */ 764 nd6_rs_input(m, off, icmp6len); 765 m = NULL; 766 goto freeit; 767 } 768 nd6_rs_input(n, off, icmp6len); 769 /* m stays. */ 770 break; 771 772 case ND_ROUTER_ADVERT: 773 icmp6_ifstat_inc(ifp, ifs6_in_routeradvert); 774 if (code != 0) 775 goto badcode; 776 if (icmp6len < sizeof(struct nd_router_advert)) 777 goto badlen; 778 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 779 /* give up local */ 780 nd6_ra_input(m, off, icmp6len); 781 m = NULL; 782 goto freeit; 783 } 784 nd6_ra_input(n, off, icmp6len); 785 /* m stays. */ 786 break; 787 788 case ND_NEIGHBOR_SOLICIT: 789 icmp6_ifstat_inc(ifp, ifs6_in_neighborsolicit); 790 if (code != 0) 791 goto badcode; 792 if (icmp6len < sizeof(struct nd_neighbor_solicit)) 793 goto badlen; 794 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 795 /* give up local */ 796 nd6_ns_input(m, off, icmp6len); 797 m = NULL; 798 goto freeit; 799 } 800 nd6_ns_input(n, off, icmp6len); 801 /* m stays. */ 802 break; 803 804 case ND_NEIGHBOR_ADVERT: 805 icmp6_ifstat_inc(ifp, ifs6_in_neighboradvert); 806 if (code != 0) 807 goto badcode; 808 if (icmp6len < sizeof(struct nd_neighbor_advert)) 809 goto badlen; 810 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 811 /* give up local */ 812 nd6_na_input(m, off, icmp6len); 813 m = NULL; 814 goto freeit; 815 } 816 nd6_na_input(n, off, icmp6len); 817 /* m stays. */ 818 break; 819 820 case ND_REDIRECT: 821 icmp6_ifstat_inc(ifp, ifs6_in_redirect); 822 if (code != 0) 823 goto badcode; 824 if (icmp6len < sizeof(struct nd_redirect)) 825 goto badlen; 826 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 827 /* give up local */ 828 icmp6_redirect_input(m, off); 829 m = NULL; 830 goto freeit; 831 } 832 icmp6_redirect_input(n, off); 833 /* m stays. */ 834 break; 835 836 case ICMP6_ROUTER_RENUMBERING: 837 if (code != ICMP6_ROUTER_RENUMBERING_COMMAND && 838 code != ICMP6_ROUTER_RENUMBERING_RESULT) 839 goto badcode; 840 if (icmp6len < sizeof(struct icmp6_router_renum)) 841 goto badlen; 842 break; 843 844 default: 845 nd6log((LOG_DEBUG, 846 "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n", 847 icmp6->icmp6_type, ip6_sprintf(ip6bufs, &ip6->ip6_src), 848 ip6_sprintf(ip6bufd, &ip6->ip6_dst), 849 ifp ? ifp->if_index : 0)); 850 if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) { 851 /* ICMPv6 error: MUST deliver it by spec... */ 852 code = PRC_NCMDS; 853 /* deliver */ 854 } else { 855 /* ICMPv6 informational: MUST not deliver */ 856 break; 857 } 858 deliver: 859 if (icmp6_notify_error(&m, off, icmp6len, code)) { 860 /* In this case, m should've been freed. */ 861 return (IPPROTO_DONE); 862 } 863 break; 864 865 badcode: 866 ICMP6STAT_INC(icp6s_badcode); 867 break; 868 869 badlen: 870 ICMP6STAT_INC(icp6s_badlen); 871 break; 872 } 873 874 /* deliver the packet to appropriate sockets */ 875 icmp6_rip6_input(&m, *offp); 876 877 return IPPROTO_DONE; 878 879 freeit: 880 m_freem(m); 881 return IPPROTO_DONE; 882} 883 884static int 885icmp6_notify_error(struct mbuf **mp, int off, int icmp6len, int code) 886{ 887 INIT_VNET_INET6(curvnet); 888 struct mbuf *m = *mp; 889 struct icmp6_hdr *icmp6; 890 struct ip6_hdr *eip6; 891 u_int32_t notifymtu; 892 struct sockaddr_in6 icmp6src, icmp6dst; 893 894 if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) { 895 ICMP6STAT_INC(icp6s_tooshort); 896 goto freeit; 897 } 898#ifndef PULLDOWN_TEST 899 IP6_EXTHDR_CHECK(m, off, 900 sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr), -1); 901 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 902#else 903 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, 904 sizeof(*icmp6) + sizeof(struct ip6_hdr)); 905 if (icmp6 == NULL) { 906 ICMP6STAT_INC(icp6s_tooshort); 907 return (-1); 908 } 909#endif 910 eip6 = (struct ip6_hdr *)(icmp6 + 1); 911 912 /* Detect the upper level protocol */ 913 { 914 void (*ctlfunc)(int, struct sockaddr *, void *); 915 u_int8_t nxt = eip6->ip6_nxt; 916 int eoff = off + sizeof(struct icmp6_hdr) + 917 sizeof(struct ip6_hdr); 918 struct ip6ctlparam ip6cp; 919 struct in6_addr *finaldst = NULL; 920 int icmp6type = icmp6->icmp6_type; 921 struct ip6_frag *fh; 922 struct ip6_rthdr *rth; 923 struct ip6_rthdr0 *rth0; 924 int rthlen; 925 926 while (1) { /* XXX: should avoid infinite loop explicitly? */ 927 struct ip6_ext *eh; 928 929 switch (nxt) { 930 case IPPROTO_HOPOPTS: 931 case IPPROTO_DSTOPTS: 932 case IPPROTO_AH: 933#ifndef PULLDOWN_TEST 934 IP6_EXTHDR_CHECK(m, 0, 935 eoff + sizeof(struct ip6_ext), -1); 936 eh = (struct ip6_ext *)(mtod(m, caddr_t) + eoff); 937#else 938 IP6_EXTHDR_GET(eh, struct ip6_ext *, m, 939 eoff, sizeof(*eh)); 940 if (eh == NULL) { 941 ICMP6STAT_INC(icp6s_tooshort); 942 return (-1); 943 } 944#endif 945 946 if (nxt == IPPROTO_AH) 947 eoff += (eh->ip6e_len + 2) << 2; 948 else 949 eoff += (eh->ip6e_len + 1) << 3; 950 nxt = eh->ip6e_nxt; 951 break; 952 case IPPROTO_ROUTING: 953 /* 954 * When the erroneous packet contains a 955 * routing header, we should examine the 956 * header to determine the final destination. 957 * Otherwise, we can't properly update 958 * information that depends on the final 959 * destination (e.g. path MTU). 960 */ 961#ifndef PULLDOWN_TEST 962 IP6_EXTHDR_CHECK(m, 0, eoff + sizeof(*rth), -1); 963 rth = (struct ip6_rthdr *) 964 (mtod(m, caddr_t) + eoff); 965#else 966 IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m, 967 eoff, sizeof(*rth)); 968 if (rth == NULL) { 969 ICMP6STAT_INC(icp6s_tooshort); 970 return (-1); 971 } 972#endif 973 rthlen = (rth->ip6r_len + 1) << 3; 974 /* 975 * XXX: currently there is no 976 * officially defined type other 977 * than type-0. 978 * Note that if the segment left field 979 * is 0, all intermediate hops must 980 * have been passed. 981 */ 982 if (rth->ip6r_segleft && 983 rth->ip6r_type == IPV6_RTHDR_TYPE_0) { 984 int hops; 985 986#ifndef PULLDOWN_TEST 987 IP6_EXTHDR_CHECK(m, 0, eoff + rthlen, -1); 988 rth0 = (struct ip6_rthdr0 *) 989 (mtod(m, caddr_t) + eoff); 990#else 991 IP6_EXTHDR_GET(rth0, 992 struct ip6_rthdr0 *, m, 993 eoff, rthlen); 994 if (rth0 == NULL) { 995 ICMP6STAT_INC(icp6s_tooshort); 996 return (-1); 997 } 998#endif 999 /* just ignore a bogus header */ 1000 if ((rth0->ip6r0_len % 2) == 0 && 1001 (hops = rth0->ip6r0_len/2)) 1002 finaldst = (struct in6_addr *)(rth0 + 1) + (hops - 1); 1003 } 1004 eoff += rthlen; 1005 nxt = rth->ip6r_nxt; 1006 break; 1007 case IPPROTO_FRAGMENT: 1008#ifndef PULLDOWN_TEST 1009 IP6_EXTHDR_CHECK(m, 0, eoff + 1010 sizeof(struct ip6_frag), -1); 1011 fh = (struct ip6_frag *)(mtod(m, caddr_t) + 1012 eoff); 1013#else 1014 IP6_EXTHDR_GET(fh, struct ip6_frag *, m, 1015 eoff, sizeof(*fh)); 1016 if (fh == NULL) { 1017 ICMP6STAT_INC(icp6s_tooshort); 1018 return (-1); 1019 } 1020#endif 1021 /* 1022 * Data after a fragment header is meaningless 1023 * unless it is the first fragment, but 1024 * we'll go to the notify label for path MTU 1025 * discovery. 1026 */ 1027 if (fh->ip6f_offlg & IP6F_OFF_MASK) 1028 goto notify; 1029 1030 eoff += sizeof(struct ip6_frag); 1031 nxt = fh->ip6f_nxt; 1032 break; 1033 default: 1034 /* 1035 * This case includes ESP and the No Next 1036 * Header. In such cases going to the notify 1037 * label does not have any meaning 1038 * (i.e. ctlfunc will be NULL), but we go 1039 * anyway since we might have to update 1040 * path MTU information. 1041 */ 1042 goto notify; 1043 } 1044 } 1045 notify: 1046#ifndef PULLDOWN_TEST 1047 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 1048#else 1049 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, 1050 sizeof(*icmp6) + sizeof(struct ip6_hdr)); 1051 if (icmp6 == NULL) { 1052 ICMP6STAT_INC(icp6s_tooshort); 1053 return (-1); 1054 } 1055#endif 1056 1057 /* 1058 * retrieve parameters from the inner IPv6 header, and convert 1059 * them into sockaddr structures. 1060 * XXX: there is no guarantee that the source or destination 1061 * addresses of the inner packet are in the same scope as 1062 * the addresses of the icmp packet. But there is no other 1063 * way to determine the zone. 1064 */ 1065 eip6 = (struct ip6_hdr *)(icmp6 + 1); 1066 1067 bzero(&icmp6dst, sizeof(icmp6dst)); 1068 icmp6dst.sin6_len = sizeof(struct sockaddr_in6); 1069 icmp6dst.sin6_family = AF_INET6; 1070 if (finaldst == NULL) 1071 icmp6dst.sin6_addr = eip6->ip6_dst; 1072 else 1073 icmp6dst.sin6_addr = *finaldst; 1074 if (in6_setscope(&icmp6dst.sin6_addr, m->m_pkthdr.rcvif, NULL)) 1075 goto freeit; 1076 bzero(&icmp6src, sizeof(icmp6src)); 1077 icmp6src.sin6_len = sizeof(struct sockaddr_in6); 1078 icmp6src.sin6_family = AF_INET6; 1079 icmp6src.sin6_addr = eip6->ip6_src; 1080 if (in6_setscope(&icmp6src.sin6_addr, m->m_pkthdr.rcvif, NULL)) 1081 goto freeit; 1082 icmp6src.sin6_flowinfo = 1083 (eip6->ip6_flow & IPV6_FLOWLABEL_MASK); 1084 1085 if (finaldst == NULL) 1086 finaldst = &eip6->ip6_dst; 1087 ip6cp.ip6c_m = m; 1088 ip6cp.ip6c_icmp6 = icmp6; 1089 ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1); 1090 ip6cp.ip6c_off = eoff; 1091 ip6cp.ip6c_finaldst = finaldst; 1092 ip6cp.ip6c_src = &icmp6src; 1093 ip6cp.ip6c_nxt = nxt; 1094 1095 if (icmp6type == ICMP6_PACKET_TOO_BIG) { 1096 notifymtu = ntohl(icmp6->icmp6_mtu); 1097 ip6cp.ip6c_cmdarg = (void *)¬ifymtu; 1098 icmp6_mtudisc_update(&ip6cp, 1); /*XXX*/ 1099 } 1100 1101 ctlfunc = (void (*)(int, struct sockaddr *, void *)) 1102 (inet6sw[ip6_protox[nxt]].pr_ctlinput); 1103 if (ctlfunc) { 1104 (void) (*ctlfunc)(code, (struct sockaddr *)&icmp6dst, 1105 &ip6cp); 1106 } 1107 } 1108 *mp = m; 1109 return (0); 1110 1111 freeit: 1112 m_freem(m); 1113 return (-1); 1114} 1115 1116void 1117icmp6_mtudisc_update(struct ip6ctlparam *ip6cp, int validated) 1118{ 1119 INIT_VNET_INET6(curvnet); 1120 struct in6_addr *dst = ip6cp->ip6c_finaldst; 1121 struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6; 1122 struct mbuf *m = ip6cp->ip6c_m; /* will be necessary for scope issue */ 1123 u_int mtu = ntohl(icmp6->icmp6_mtu); 1124 struct in_conninfo inc; 1125 1126#if 0 1127 /* 1128 * RFC2460 section 5, last paragraph. 1129 * even though minimum link MTU for IPv6 is IPV6_MMTU, 1130 * we may see ICMPv6 too big with mtu < IPV6_MMTU 1131 * due to packet translator in the middle. 1132 * see ip6_output() and ip6_getpmtu() "alwaysfrag" case for 1133 * special handling. 1134 */ 1135 if (mtu < IPV6_MMTU) 1136 return; 1137#endif 1138 1139 /* 1140 * we reject ICMPv6 too big with abnormally small value. 1141 * XXX what is the good definition of "abnormally small"? 1142 */ 1143 if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8) 1144 return; 1145 1146 if (!validated) 1147 return; 1148 1149 /* 1150 * In case the suggested mtu is less than IPV6_MMTU, we 1151 * only need to remember that it was for above mentioned 1152 * "alwaysfrag" case. 1153 * Try to be as close to the spec as possible. 1154 */ 1155 if (mtu < IPV6_MMTU) 1156 mtu = IPV6_MMTU - 8; 1157 1158 bzero(&inc, sizeof(inc)); 1159 inc.inc_flags |= INC_ISIPV6; 1160 inc.inc6_faddr = *dst; 1161 if (in6_setscope(&inc.inc6_faddr, m->m_pkthdr.rcvif, NULL)) 1162 return; 1163 1164 if (mtu < tcp_maxmtu6(&inc, NULL)) { 1165 tcp_hc_updatemtu(&inc, mtu); 1166 ICMP6STAT_INC(icp6s_pmtuchg); 1167 } 1168} 1169 1170/* 1171 * Process a Node Information Query packet, based on 1172 * draft-ietf-ipngwg-icmp-name-lookups-07. 1173 * 1174 * Spec incompatibilities: 1175 * - IPv6 Subject address handling 1176 * - IPv4 Subject address handling support missing 1177 * - Proxy reply (answer even if it's not for me) 1178 * - joins NI group address at in6_ifattach() time only, does not cope 1179 * with hostname changes by sethostname(3) 1180 */ 1181static struct mbuf * 1182ni6_input(struct mbuf *m, int off) 1183{ 1184 INIT_VNET_INET6(curvnet); 1185 struct icmp6_nodeinfo *ni6, *nni6; 1186 struct mbuf *n = NULL; 1187 struct prison *pr; 1188 u_int16_t qtype; 1189 int subjlen; 1190 int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); 1191 struct ni_reply_fqdn *fqdn; 1192 int addrs; /* for NI_QTYPE_NODEADDR */ 1193 struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */ 1194 struct in6_addr in6_subj; /* subject address */ 1195 struct ip6_hdr *ip6; 1196 int oldfqdn = 0; /* if 1, return pascal string (03 draft) */ 1197 char *subj = NULL; 1198 struct in6_ifaddr *ia6 = NULL; 1199 1200 ip6 = mtod(m, struct ip6_hdr *); 1201#ifndef PULLDOWN_TEST 1202 ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off); 1203#else 1204 IP6_EXTHDR_GET(ni6, struct icmp6_nodeinfo *, m, off, sizeof(*ni6)); 1205 if (ni6 == NULL) { 1206 /* m is already reclaimed */ 1207 return (NULL); 1208 } 1209#endif 1210 1211 /* 1212 * Validate IPv6 source address. 1213 * The default configuration MUST be to refuse answering queries from 1214 * global-scope addresses according to RFC4602. 1215 * Notes: 1216 * - it's not very clear what "refuse" means; this implementation 1217 * simply drops it. 1218 * - it's not very easy to identify global-scope (unicast) addresses 1219 * since there are many prefixes for them. It should be safer 1220 * and in practice sufficient to check "all" but loopback and 1221 * link-local (note that site-local unicast was deprecated and 1222 * ULA is defined as global scope-wise) 1223 */ 1224 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_GLOBALOK) == 0 && 1225 !IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) && 1226 !IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) 1227 goto bad; 1228 1229 /* 1230 * Validate IPv6 destination address. 1231 * 1232 * The Responder must discard the Query without further processing 1233 * unless it is one of the Responder's unicast or anycast addresses, or 1234 * a link-local scope multicast address which the Responder has joined. 1235 * [RFC4602, Section 5.] 1236 */ 1237 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 1238 if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst)) 1239 goto bad; 1240 /* else it's a link-local multicast, fine */ 1241 } else { /* unicast or anycast */ 1242 if ((ia6 = ip6_getdstifaddr(m)) == NULL) 1243 goto bad; /* XXX impossible */ 1244 1245 if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) && 1246 !(V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK)) { 1247 ifa_free(&ia6->ia_ifa); 1248 nd6log((LOG_DEBUG, "ni6_input: ignore node info to " 1249 "a temporary address in %s:%d", 1250 __FILE__, __LINE__)); 1251 goto bad; 1252 } 1253 ifa_free(&ia6->ia_ifa); 1254 } 1255 1256 /* validate query Subject field. */ 1257 qtype = ntohs(ni6->ni_qtype); 1258 subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo); 1259 switch (qtype) { 1260 case NI_QTYPE_NOOP: 1261 case NI_QTYPE_SUPTYPES: 1262 /* 07 draft */ 1263 if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0) 1264 break; 1265 /* FALLTHROUGH */ 1266 case NI_QTYPE_FQDN: 1267 case NI_QTYPE_NODEADDR: 1268 case NI_QTYPE_IPV4ADDR: 1269 switch (ni6->ni_code) { 1270 case ICMP6_NI_SUBJ_IPV6: 1271#if ICMP6_NI_SUBJ_IPV6 != 0 1272 case 0: 1273#endif 1274 /* 1275 * backward compatibility - try to accept 03 draft 1276 * format, where no Subject is present. 1277 */ 1278 if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 && 1279 subjlen == 0) { 1280 oldfqdn++; 1281 break; 1282 } 1283#if ICMP6_NI_SUBJ_IPV6 != 0 1284 if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6) 1285 goto bad; 1286#endif 1287 1288 if (subjlen != sizeof(struct in6_addr)) 1289 goto bad; 1290 1291 /* 1292 * Validate Subject address. 1293 * 1294 * Not sure what exactly "address belongs to the node" 1295 * means in the spec, is it just unicast, or what? 1296 * 1297 * At this moment we consider Subject address as 1298 * "belong to the node" if the Subject address equals 1299 * to the IPv6 destination address; validation for 1300 * IPv6 destination address should have done enough 1301 * check for us. 1302 * 1303 * We do not do proxy at this moment. 1304 */ 1305 /* m_pulldown instead of copy? */ 1306 m_copydata(m, off + sizeof(struct icmp6_nodeinfo), 1307 subjlen, (caddr_t)&in6_subj); 1308 if (in6_setscope(&in6_subj, m->m_pkthdr.rcvif, NULL)) 1309 goto bad; 1310 1311 subj = (char *)&in6_subj; 1312 if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &in6_subj)) 1313 break; 1314 1315 /* 1316 * XXX if we are to allow other cases, we should really 1317 * be careful about scope here. 1318 * basically, we should disallow queries toward IPv6 1319 * destination X with subject Y, 1320 * if scope(X) > scope(Y). 1321 * if we allow scope(X) > scope(Y), it will result in 1322 * information leakage across scope boundary. 1323 */ 1324 goto bad; 1325 1326 case ICMP6_NI_SUBJ_FQDN: 1327 /* 1328 * Validate Subject name with gethostname(3). 1329 * 1330 * The behavior may need some debate, since: 1331 * - we are not sure if the node has FQDN as 1332 * hostname (returned by gethostname(3)). 1333 * - the code does wildcard match for truncated names. 1334 * however, we are not sure if we want to perform 1335 * wildcard match, if gethostname(3) side has 1336 * truncated hostname. 1337 */ 1338 pr = curthread->td_ucred->cr_prison; 1339 mtx_lock(&pr->pr_mtx); 1340 n = ni6_nametodns(pr->pr_hostname, 1341 strlen(pr->pr_hostname), 0); 1342 mtx_unlock(&pr->pr_mtx); 1343 if (!n || n->m_next || n->m_len == 0) 1344 goto bad; 1345 IP6_EXTHDR_GET(subj, char *, m, 1346 off + sizeof(struct icmp6_nodeinfo), subjlen); 1347 if (subj == NULL) 1348 goto bad; 1349 if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *), 1350 n->m_len)) { 1351 goto bad; 1352 } 1353 m_freem(n); 1354 n = NULL; 1355 break; 1356 1357 case ICMP6_NI_SUBJ_IPV4: /* XXX: to be implemented? */ 1358 default: 1359 goto bad; 1360 } 1361 break; 1362 } 1363 1364 /* refuse based on configuration. XXX ICMP6_NI_REFUSED? */ 1365 switch (qtype) { 1366 case NI_QTYPE_FQDN: 1367 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_FQDNOK) == 0) 1368 goto bad; 1369 break; 1370 case NI_QTYPE_NODEADDR: 1371 case NI_QTYPE_IPV4ADDR: 1372 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_NODEADDROK) == 0) 1373 goto bad; 1374 break; 1375 } 1376 1377 /* guess reply length */ 1378 switch (qtype) { 1379 case NI_QTYPE_NOOP: 1380 break; /* no reply data */ 1381 case NI_QTYPE_SUPTYPES: 1382 replylen += sizeof(u_int32_t); 1383 break; 1384 case NI_QTYPE_FQDN: 1385 /* XXX will append an mbuf */ 1386 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); 1387 break; 1388 case NI_QTYPE_NODEADDR: 1389 addrs = ni6_addrs(ni6, m, &ifp, (struct in6_addr *)subj); 1390 if ((replylen += addrs * (sizeof(struct in6_addr) + 1391 sizeof(u_int32_t))) > MCLBYTES) 1392 replylen = MCLBYTES; /* XXX: will truncate pkt later */ 1393 break; 1394 case NI_QTYPE_IPV4ADDR: 1395 /* unsupported - should respond with unknown Qtype? */ 1396 break; 1397 default: 1398 /* 1399 * XXX: We must return a reply with the ICMP6 code 1400 * `unknown Qtype' in this case. However we regard the case 1401 * as an FQDN query for backward compatibility. 1402 * Older versions set a random value to this field, 1403 * so it rarely varies in the defined qtypes. 1404 * But the mechanism is not reliable... 1405 * maybe we should obsolete older versions. 1406 */ 1407 qtype = NI_QTYPE_FQDN; 1408 /* XXX will append an mbuf */ 1409 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); 1410 oldfqdn++; 1411 break; 1412 } 1413 1414 /* allocate an mbuf to reply. */ 1415 MGETHDR(n, M_DONTWAIT, m->m_type); 1416 if (n == NULL) { 1417 m_freem(m); 1418 return (NULL); 1419 } 1420 M_MOVE_PKTHDR(n, m); /* just for recvif */ 1421 if (replylen > MHLEN) { 1422 if (replylen > MCLBYTES) { 1423 /* 1424 * XXX: should we try to allocate more? But MCLBYTES 1425 * is probably much larger than IPV6_MMTU... 1426 */ 1427 goto bad; 1428 } 1429 MCLGET(n, M_DONTWAIT); 1430 if ((n->m_flags & M_EXT) == 0) { 1431 goto bad; 1432 } 1433 } 1434 n->m_pkthdr.len = n->m_len = replylen; 1435 1436 /* copy mbuf header and IPv6 + Node Information base headers */ 1437 bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr)); 1438 nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1); 1439 bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo)); 1440 1441 /* qtype dependent procedure */ 1442 switch (qtype) { 1443 case NI_QTYPE_NOOP: 1444 nni6->ni_code = ICMP6_NI_SUCCESS; 1445 nni6->ni_flags = 0; 1446 break; 1447 case NI_QTYPE_SUPTYPES: 1448 { 1449 u_int32_t v; 1450 nni6->ni_code = ICMP6_NI_SUCCESS; 1451 nni6->ni_flags = htons(0x0000); /* raw bitmap */ 1452 /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */ 1453 v = (u_int32_t)htonl(0x0000000f); 1454 bcopy(&v, nni6 + 1, sizeof(u_int32_t)); 1455 break; 1456 } 1457 case NI_QTYPE_FQDN: 1458 nni6->ni_code = ICMP6_NI_SUCCESS; 1459 fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) + 1460 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo)); 1461 nni6->ni_flags = 0; /* XXX: meaningless TTL */ 1462 fqdn->ni_fqdn_ttl = 0; /* ditto. */ 1463 /* 1464 * XXX do we really have FQDN in hostname? 1465 */ 1466 pr = curthread->td_ucred->cr_prison; 1467 mtx_lock(&pr->pr_mtx); 1468 n->m_next = ni6_nametodns(pr->pr_hostname, 1469 strlen(pr->pr_hostname), oldfqdn); 1470 mtx_unlock(&pr->pr_mtx); 1471 if (n->m_next == NULL) 1472 goto bad; 1473 /* XXX we assume that n->m_next is not a chain */ 1474 if (n->m_next->m_next != NULL) 1475 goto bad; 1476 n->m_pkthdr.len += n->m_next->m_len; 1477 break; 1478 case NI_QTYPE_NODEADDR: 1479 { 1480 int lenlim, copied; 1481 1482 nni6->ni_code = ICMP6_NI_SUCCESS; 1483 n->m_pkthdr.len = n->m_len = 1484 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); 1485 lenlim = M_TRAILINGSPACE(n); 1486 copied = ni6_store_addrs(ni6, nni6, ifp, lenlim); 1487 /* XXX: reset mbuf length */ 1488 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + 1489 sizeof(struct icmp6_nodeinfo) + copied; 1490 break; 1491 } 1492 default: 1493 break; /* XXX impossible! */ 1494 } 1495 1496 nni6->ni_type = ICMP6_NI_REPLY; 1497 m_freem(m); 1498 return (n); 1499 1500 bad: 1501 m_freem(m); 1502 if (n) 1503 m_freem(n); 1504 return (NULL); 1505} 1506 1507/* 1508 * make a mbuf with DNS-encoded string. no compression support. 1509 * 1510 * XXX names with less than 2 dots (like "foo" or "foo.section") will be 1511 * treated as truncated name (two \0 at the end). this is a wild guess. 1512 * 1513 * old - return pascal string if non-zero 1514 */ 1515static struct mbuf * 1516ni6_nametodns(const char *name, int namelen, int old) 1517{ 1518 struct mbuf *m; 1519 char *cp, *ep; 1520 const char *p, *q; 1521 int i, len, nterm; 1522 1523 if (old) 1524 len = namelen + 1; 1525 else 1526 len = MCLBYTES; 1527 1528 /* because MAXHOSTNAMELEN is usually 256, we use cluster mbuf */ 1529 MGET(m, M_DONTWAIT, MT_DATA); 1530 if (m && len > MLEN) { 1531 MCLGET(m, M_DONTWAIT); 1532 if ((m->m_flags & M_EXT) == 0) 1533 goto fail; 1534 } 1535 if (!m) 1536 goto fail; 1537 m->m_next = NULL; 1538 1539 if (old) { 1540 m->m_len = len; 1541 *mtod(m, char *) = namelen; 1542 bcopy(name, mtod(m, char *) + 1, namelen); 1543 return m; 1544 } else { 1545 m->m_len = 0; 1546 cp = mtod(m, char *); 1547 ep = mtod(m, char *) + M_TRAILINGSPACE(m); 1548 1549 /* if not certain about my name, return empty buffer */ 1550 if (namelen == 0) 1551 return m; 1552 1553 /* 1554 * guess if it looks like shortened hostname, or FQDN. 1555 * shortened hostname needs two trailing "\0". 1556 */ 1557 i = 0; 1558 for (p = name; p < name + namelen; p++) { 1559 if (*p && *p == '.') 1560 i++; 1561 } 1562 if (i < 2) 1563 nterm = 2; 1564 else 1565 nterm = 1; 1566 1567 p = name; 1568 while (cp < ep && p < name + namelen) { 1569 i = 0; 1570 for (q = p; q < name + namelen && *q && *q != '.'; q++) 1571 i++; 1572 /* result does not fit into mbuf */ 1573 if (cp + i + 1 >= ep) 1574 goto fail; 1575 /* 1576 * DNS label length restriction, RFC1035 page 8. 1577 * "i == 0" case is included here to avoid returning 1578 * 0-length label on "foo..bar". 1579 */ 1580 if (i <= 0 || i >= 64) 1581 goto fail; 1582 *cp++ = i; 1583 bcopy(p, cp, i); 1584 cp += i; 1585 p = q; 1586 if (p < name + namelen && *p == '.') 1587 p++; 1588 } 1589 /* termination */ 1590 if (cp + nterm >= ep) 1591 goto fail; 1592 while (nterm-- > 0) 1593 *cp++ = '\0'; 1594 m->m_len = cp - mtod(m, char *); 1595 return m; 1596 } 1597 1598 panic("should not reach here"); 1599 /* NOTREACHED */ 1600 1601 fail: 1602 if (m) 1603 m_freem(m); 1604 return NULL; 1605} 1606 1607/* 1608 * check if two DNS-encoded string matches. takes care of truncated 1609 * form (with \0\0 at the end). no compression support. 1610 * XXX upper/lowercase match (see RFC2065) 1611 */ 1612static int 1613ni6_dnsmatch(const char *a, int alen, const char *b, int blen) 1614{ 1615 const char *a0, *b0; 1616 int l; 1617 1618 /* simplest case - need validation? */ 1619 if (alen == blen && bcmp(a, b, alen) == 0) 1620 return 1; 1621 1622 a0 = a; 1623 b0 = b; 1624 1625 /* termination is mandatory */ 1626 if (alen < 2 || blen < 2) 1627 return 0; 1628 if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0') 1629 return 0; 1630 alen--; 1631 blen--; 1632 1633 while (a - a0 < alen && b - b0 < blen) { 1634 if (a - a0 + 1 > alen || b - b0 + 1 > blen) 1635 return 0; 1636 1637 if ((signed char)a[0] < 0 || (signed char)b[0] < 0) 1638 return 0; 1639 /* we don't support compression yet */ 1640 if (a[0] >= 64 || b[0] >= 64) 1641 return 0; 1642 1643 /* truncated case */ 1644 if (a[0] == 0 && a - a0 == alen - 1) 1645 return 1; 1646 if (b[0] == 0 && b - b0 == blen - 1) 1647 return 1; 1648 if (a[0] == 0 || b[0] == 0) 1649 return 0; 1650 1651 if (a[0] != b[0]) 1652 return 0; 1653 l = a[0]; 1654 if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen) 1655 return 0; 1656 if (bcmp(a + 1, b + 1, l) != 0) 1657 return 0; 1658 1659 a += 1 + l; 1660 b += 1 + l; 1661 } 1662 1663 if (a - a0 == alen && b - b0 == blen) 1664 return 1; 1665 else 1666 return 0; 1667} 1668 1669/* 1670 * calculate the number of addresses to be returned in the node info reply. 1671 */ 1672static int 1673ni6_addrs(struct icmp6_nodeinfo *ni6, struct mbuf *m, struct ifnet **ifpp, 1674 struct in6_addr *subj) 1675{ 1676 INIT_VNET_NET(curvnet); 1677 INIT_VNET_INET6(curvnet); 1678 struct ifnet *ifp; 1679 struct in6_ifaddr *ifa6; 1680 struct ifaddr *ifa; 1681 int addrs = 0, addrsofif, iffound = 0; 1682 int niflags = ni6->ni_flags; 1683 1684 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) { 1685 switch (ni6->ni_code) { 1686 case ICMP6_NI_SUBJ_IPV6: 1687 if (subj == NULL) /* must be impossible... */ 1688 return (0); 1689 break; 1690 default: 1691 /* 1692 * XXX: we only support IPv6 subject address for 1693 * this Qtype. 1694 */ 1695 return (0); 1696 } 1697 } 1698 1699 IFNET_RLOCK(); 1700 for (ifp = TAILQ_FIRST(&V_ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list)) { 1701 addrsofif = 0; 1702 IF_ADDR_LOCK(ifp); 1703 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 1704 if (ifa->ifa_addr->sa_family != AF_INET6) 1705 continue; 1706 ifa6 = (struct in6_ifaddr *)ifa; 1707 1708 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 && 1709 IN6_ARE_ADDR_EQUAL(subj, &ifa6->ia_addr.sin6_addr)) 1710 iffound = 1; 1711 1712 /* 1713 * IPv4-mapped addresses can only be returned by a 1714 * Node Information proxy, since they represent 1715 * addresses of IPv4-only nodes, which perforce do 1716 * not implement this protocol. 1717 * [icmp-name-lookups-07, Section 5.4] 1718 * So we don't support NI_NODEADDR_FLAG_COMPAT in 1719 * this function at this moment. 1720 */ 1721 1722 /* What do we have to do about ::1? */ 1723 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { 1724 case IPV6_ADDR_SCOPE_LINKLOCAL: 1725 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) 1726 continue; 1727 break; 1728 case IPV6_ADDR_SCOPE_SITELOCAL: 1729 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) 1730 continue; 1731 break; 1732 case IPV6_ADDR_SCOPE_GLOBAL: 1733 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) 1734 continue; 1735 break; 1736 default: 1737 continue; 1738 } 1739 1740 /* 1741 * check if anycast is okay. 1742 * XXX: just experimental. not in the spec. 1743 */ 1744 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && 1745 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) 1746 continue; /* we need only unicast addresses */ 1747 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && 1748 (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) { 1749 continue; 1750 } 1751 addrsofif++; /* count the address */ 1752 } 1753 IF_ADDR_UNLOCK(ifp); 1754 if (iffound) { 1755 *ifpp = ifp; 1756 IFNET_RUNLOCK(); 1757 return (addrsofif); 1758 } 1759 1760 addrs += addrsofif; 1761 } 1762 IFNET_RUNLOCK(); 1763 1764 return (addrs); 1765} 1766 1767static int 1768ni6_store_addrs(struct icmp6_nodeinfo *ni6, struct icmp6_nodeinfo *nni6, 1769 struct ifnet *ifp0, int resid) 1770{ 1771 INIT_VNET_NET(curvnet); 1772 INIT_VNET_INET6(curvnet); 1773 struct ifnet *ifp = ifp0 ? ifp0 : TAILQ_FIRST(&V_ifnet); 1774 struct in6_ifaddr *ifa6; 1775 struct ifaddr *ifa; 1776 struct ifnet *ifp_dep = NULL; 1777 int copied = 0, allow_deprecated = 0; 1778 u_char *cp = (u_char *)(nni6 + 1); 1779 int niflags = ni6->ni_flags; 1780 u_int32_t ltime; 1781 1782 if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL)) 1783 return (0); /* needless to copy */ 1784 1785 IFNET_RLOCK(); 1786 again: 1787 1788 for (; ifp; ifp = TAILQ_NEXT(ifp, if_list)) { 1789 IF_ADDR_LOCK(ifp); 1790 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 1791 if (ifa->ifa_addr->sa_family != AF_INET6) 1792 continue; 1793 ifa6 = (struct in6_ifaddr *)ifa; 1794 1795 if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 && 1796 allow_deprecated == 0) { 1797 /* 1798 * prefererred address should be put before 1799 * deprecated addresses. 1800 */ 1801 1802 /* record the interface for later search */ 1803 if (ifp_dep == NULL) 1804 ifp_dep = ifp; 1805 1806 continue; 1807 } else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 && 1808 allow_deprecated != 0) 1809 continue; /* we now collect deprecated addrs */ 1810 1811 /* What do we have to do about ::1? */ 1812 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { 1813 case IPV6_ADDR_SCOPE_LINKLOCAL: 1814 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) 1815 continue; 1816 break; 1817 case IPV6_ADDR_SCOPE_SITELOCAL: 1818 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) 1819 continue; 1820 break; 1821 case IPV6_ADDR_SCOPE_GLOBAL: 1822 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) 1823 continue; 1824 break; 1825 default: 1826 continue; 1827 } 1828 1829 /* 1830 * check if anycast is okay. 1831 * XXX: just experimental. not in the spec. 1832 */ 1833 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && 1834 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) 1835 continue; 1836 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && 1837 (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) { 1838 continue; 1839 } 1840 1841 /* now we can copy the address */ 1842 if (resid < sizeof(struct in6_addr) + 1843 sizeof(u_int32_t)) { 1844 IF_ADDR_UNLOCK(ifp); 1845 /* 1846 * We give up much more copy. 1847 * Set the truncate flag and return. 1848 */ 1849 nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE; 1850 IFNET_RUNLOCK(); 1851 return (copied); 1852 } 1853 1854 /* 1855 * Set the TTL of the address. 1856 * The TTL value should be one of the following 1857 * according to the specification: 1858 * 1859 * 1. The remaining lifetime of a DHCP lease on the 1860 * address, or 1861 * 2. The remaining Valid Lifetime of a prefix from 1862 * which the address was derived through Stateless 1863 * Autoconfiguration. 1864 * 1865 * Note that we currently do not support stateful 1866 * address configuration by DHCPv6, so the former 1867 * case can't happen. 1868 */ 1869 if (ifa6->ia6_lifetime.ia6t_expire == 0) 1870 ltime = ND6_INFINITE_LIFETIME; 1871 else { 1872 if (ifa6->ia6_lifetime.ia6t_expire > 1873 time_second) 1874 ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_second); 1875 else 1876 ltime = 0; 1877 } 1878 1879 bcopy(<ime, cp, sizeof(u_int32_t)); 1880 cp += sizeof(u_int32_t); 1881 1882 /* copy the address itself */ 1883 bcopy(&ifa6->ia_addr.sin6_addr, cp, 1884 sizeof(struct in6_addr)); 1885 in6_clearscope((struct in6_addr *)cp); /* XXX */ 1886 cp += sizeof(struct in6_addr); 1887 1888 resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t)); 1889 copied += (sizeof(struct in6_addr) + sizeof(u_int32_t)); 1890 } 1891 IF_ADDR_UNLOCK(ifp); 1892 if (ifp0) /* we need search only on the specified IF */ 1893 break; 1894 } 1895 1896 if (allow_deprecated == 0 && ifp_dep != NULL) { 1897 ifp = ifp_dep; 1898 allow_deprecated = 1; 1899 1900 goto again; 1901 } 1902 1903 IFNET_RUNLOCK(); 1904 1905 return (copied); 1906} 1907 1908/* 1909 * XXX almost dup'ed code with rip6_input. 1910 */ 1911static int 1912icmp6_rip6_input(struct mbuf **mp, int off) 1913{ 1914 INIT_VNET_INET(curvnet); 1915 INIT_VNET_INET6(curvnet); 1916 struct mbuf *m = *mp; 1917 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1918 struct inpcb *in6p; 1919 struct inpcb *last = NULL; 1920 struct sockaddr_in6 fromsa; 1921 struct icmp6_hdr *icmp6; 1922 struct mbuf *opts = NULL; 1923 1924#ifndef PULLDOWN_TEST 1925 /* this is assumed to be safe. */ 1926 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off); 1927#else 1928 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6)); 1929 if (icmp6 == NULL) { 1930 /* m is already reclaimed */ 1931 return (IPPROTO_DONE); 1932 } 1933#endif 1934 1935 /* 1936 * XXX: the address may have embedded scope zone ID, which should be 1937 * hidden from applications. 1938 */ 1939 bzero(&fromsa, sizeof(fromsa)); 1940 fromsa.sin6_family = AF_INET6; 1941 fromsa.sin6_len = sizeof(struct sockaddr_in6); 1942 fromsa.sin6_addr = ip6->ip6_src; 1943 if (sa6_recoverscope(&fromsa)) { 1944 m_freem(m); 1945 return (IPPROTO_DONE); 1946 } 1947 1948 INP_INFO_RLOCK(&V_ripcbinfo); 1949 LIST_FOREACH(in6p, &V_ripcb, inp_list) { 1950 if ((in6p->inp_vflag & INP_IPV6) == 0) 1951 continue; 1952 if (in6p->inp_ip_p != IPPROTO_ICMPV6) 1953 continue; 1954 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) && 1955 !IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &ip6->ip6_dst)) 1956 continue; 1957 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr) && 1958 !IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src)) 1959 continue; 1960 INP_RLOCK(in6p); 1961 if (ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type, 1962 in6p->in6p_icmp6filt)) { 1963 INP_RUNLOCK(in6p); 1964 continue; 1965 } 1966 if (last != NULL) { 1967 struct mbuf *n = NULL; 1968 1969 /* 1970 * Recent network drivers tend to allocate a single 1971 * mbuf cluster, rather than to make a couple of 1972 * mbufs without clusters. Also, since the IPv6 code 1973 * path tries to avoid m_pullup(), it is highly 1974 * probable that we still have an mbuf cluster here 1975 * even though the necessary length can be stored in an 1976 * mbuf's internal buffer. 1977 * Meanwhile, the default size of the receive socket 1978 * buffer for raw sockets is not so large. This means 1979 * the possibility of packet loss is relatively higher 1980 * than before. To avoid this scenario, we copy the 1981 * received data to a separate mbuf that does not use 1982 * a cluster, if possible. 1983 * XXX: it is better to copy the data after stripping 1984 * intermediate headers. 1985 */ 1986 if ((m->m_flags & M_EXT) && m->m_next == NULL && 1987 m->m_len <= MHLEN) { 1988 MGET(n, M_DONTWAIT, m->m_type); 1989 if (n != NULL) { 1990 if (m_dup_pkthdr(n, m, M_NOWAIT)) { 1991 bcopy(m->m_data, n->m_data, 1992 m->m_len); 1993 n->m_len = m->m_len; 1994 } else { 1995 m_free(n); 1996 n = NULL; 1997 } 1998 } 1999 } 2000 if (n != NULL || 2001 (n = m_copy(m, 0, (int)M_COPYALL)) != NULL) { 2002 if (last->inp_flags & INP_CONTROLOPTS) 2003 ip6_savecontrol(last, n, &opts); 2004 /* strip intermediate headers */ 2005 m_adj(n, off); 2006 SOCKBUF_LOCK(&last->inp_socket->so_rcv); 2007 if (sbappendaddr_locked( 2008 &last->inp_socket->so_rcv, 2009 (struct sockaddr *)&fromsa, n, opts) 2010 == 0) { 2011 /* should notify about lost packet */ 2012 m_freem(n); 2013 if (opts) { 2014 m_freem(opts); 2015 } 2016 SOCKBUF_UNLOCK( 2017 &last->inp_socket->so_rcv); 2018 } else 2019 sorwakeup_locked(last->inp_socket); 2020 opts = NULL; 2021 } 2022 INP_RUNLOCK(last); 2023 } 2024 last = in6p; 2025 } 2026 INP_INFO_RUNLOCK(&V_ripcbinfo); 2027 if (last != NULL) { 2028 if (last->inp_flags & INP_CONTROLOPTS) 2029 ip6_savecontrol(last, m, &opts); 2030 /* strip intermediate headers */ 2031 m_adj(m, off); 2032 2033 /* avoid using mbuf clusters if possible (see above) */ 2034 if ((m->m_flags & M_EXT) && m->m_next == NULL && 2035 m->m_len <= MHLEN) { 2036 struct mbuf *n; 2037 2038 MGET(n, M_DONTWAIT, m->m_type); 2039 if (n != NULL) { 2040 if (m_dup_pkthdr(n, m, M_NOWAIT)) { 2041 bcopy(m->m_data, n->m_data, m->m_len); 2042 n->m_len = m->m_len; 2043 2044 m_freem(m); 2045 m = n; 2046 } else { 2047 m_freem(n); 2048 n = NULL; 2049 } 2050 } 2051 } 2052 SOCKBUF_LOCK(&last->inp_socket->so_rcv); 2053 if (sbappendaddr_locked(&last->inp_socket->so_rcv, 2054 (struct sockaddr *)&fromsa, m, opts) == 0) { 2055 m_freem(m); 2056 if (opts) 2057 m_freem(opts); 2058 SOCKBUF_UNLOCK(&last->inp_socket->so_rcv); 2059 } else 2060 sorwakeup_locked(last->inp_socket); 2061 INP_RUNLOCK(last); 2062 } else { 2063 m_freem(m); 2064 IP6STAT_DEC(ip6s_delivered); 2065 } 2066 return IPPROTO_DONE; 2067} 2068 2069/* 2070 * Reflect the ip6 packet back to the source. 2071 * OFF points to the icmp6 header, counted from the top of the mbuf. 2072 */ 2073void 2074icmp6_reflect(struct mbuf *m, size_t off) 2075{ 2076 INIT_VNET_INET6(curvnet); 2077 struct ip6_hdr *ip6; 2078 struct icmp6_hdr *icmp6; 2079 struct in6_ifaddr *ia = NULL; 2080 int plen; 2081 int type, code; 2082 struct ifnet *outif = NULL; 2083 struct in6_addr origdst, src, *srcp = NULL; 2084 2085 /* too short to reflect */ 2086 if (off < sizeof(struct ip6_hdr)) { 2087 nd6log((LOG_DEBUG, 2088 "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n", 2089 (u_long)off, (u_long)sizeof(struct ip6_hdr), 2090 __FILE__, __LINE__)); 2091 goto bad; 2092 } 2093 2094 /* 2095 * If there are extra headers between IPv6 and ICMPv6, strip 2096 * off that header first. 2097 */ 2098#ifdef DIAGNOSTIC 2099 if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN) 2100 panic("assumption failed in icmp6_reflect"); 2101#endif 2102 if (off > sizeof(struct ip6_hdr)) { 2103 size_t l; 2104 struct ip6_hdr nip6; 2105 2106 l = off - sizeof(struct ip6_hdr); 2107 m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6); 2108 m_adj(m, l); 2109 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 2110 if (m->m_len < l) { 2111 if ((m = m_pullup(m, l)) == NULL) 2112 return; 2113 } 2114 bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6)); 2115 } else /* off == sizeof(struct ip6_hdr) */ { 2116 size_t l; 2117 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 2118 if (m->m_len < l) { 2119 if ((m = m_pullup(m, l)) == NULL) 2120 return; 2121 } 2122 } 2123 plen = m->m_pkthdr.len - sizeof(struct ip6_hdr); 2124 ip6 = mtod(m, struct ip6_hdr *); 2125 ip6->ip6_nxt = IPPROTO_ICMPV6; 2126 icmp6 = (struct icmp6_hdr *)(ip6 + 1); 2127 type = icmp6->icmp6_type; /* keep type for statistics */ 2128 code = icmp6->icmp6_code; /* ditto. */ 2129 2130 origdst = ip6->ip6_dst; 2131 /* 2132 * ip6_input() drops a packet if its src is multicast. 2133 * So, the src is never multicast. 2134 */ 2135 ip6->ip6_dst = ip6->ip6_src; 2136 2137 /* 2138 * If the incoming packet was addressed directly to us (i.e. unicast), 2139 * use dst as the src for the reply. 2140 * The IN6_IFF_NOTREADY case should be VERY rare, but is possible 2141 * (for example) when we encounter an error while forwarding procedure 2142 * destined to a duplicated address of ours. 2143 * Note that ip6_getdstifaddr() may fail if we are in an error handling 2144 * procedure of an outgoing packet of our own, in which case we need 2145 * to search in the ifaddr list. 2146 */ 2147 if (!IN6_IS_ADDR_MULTICAST(&origdst)) { 2148 if ((ia = ip6_getdstifaddr(m))) { 2149 if (!(ia->ia6_flags & 2150 (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) 2151 srcp = &ia->ia_addr.sin6_addr; 2152 } else { 2153 struct sockaddr_in6 d; 2154 2155 bzero(&d, sizeof(d)); 2156 d.sin6_family = AF_INET6; 2157 d.sin6_len = sizeof(d); 2158 d.sin6_addr = origdst; 2159 ia = (struct in6_ifaddr *) 2160 ifa_ifwithaddr((struct sockaddr *)&d); 2161 if (ia && 2162 !(ia->ia6_flags & 2163 (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) { 2164 srcp = &ia->ia_addr.sin6_addr; 2165 } 2166 } 2167 } 2168 2169 if (srcp == NULL) { 2170 int e; 2171 struct sockaddr_in6 sin6; 2172 struct route_in6 ro; 2173 2174 /* 2175 * This case matches to multicasts, our anycast, or unicasts 2176 * that we do not own. Select a source address based on the 2177 * source address of the erroneous packet. 2178 */ 2179 bzero(&sin6, sizeof(sin6)); 2180 sin6.sin6_family = AF_INET6; 2181 sin6.sin6_len = sizeof(sin6); 2182 sin6.sin6_addr = ip6->ip6_dst; /* zone ID should be embedded */ 2183 2184 bzero(&ro, sizeof(ro)); 2185 e = in6_selectsrc(&sin6, NULL, NULL, &ro, NULL, &outif, &src); 2186 if (ro.ro_rt) 2187 RTFREE(ro.ro_rt); /* XXX: we could use this */ 2188 if (e) { 2189 char ip6buf[INET6_ADDRSTRLEN]; 2190 nd6log((LOG_DEBUG, 2191 "icmp6_reflect: source can't be determined: " 2192 "dst=%s, error=%d\n", 2193 ip6_sprintf(ip6buf, &sin6.sin6_addr), e)); 2194 goto bad; 2195 } 2196 srcp = &src; 2197 } 2198 2199 ip6->ip6_src = *srcp; 2200 ip6->ip6_flow = 0; 2201 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2202 ip6->ip6_vfc |= IPV6_VERSION; 2203 ip6->ip6_nxt = IPPROTO_ICMPV6; 2204 if (outif) 2205 ip6->ip6_hlim = ND_IFINFO(outif)->chlim; 2206 else if (m->m_pkthdr.rcvif) { 2207 /* XXX: This may not be the outgoing interface */ 2208 ip6->ip6_hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim; 2209 } else 2210 ip6->ip6_hlim = V_ip6_defhlim; 2211 2212 icmp6->icmp6_cksum = 0; 2213 icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2214 sizeof(struct ip6_hdr), plen); 2215 2216 /* 2217 * XXX option handling 2218 */ 2219 2220 m->m_flags &= ~(M_BCAST|M_MCAST); 2221 2222 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2223 if (outif) 2224 icmp6_ifoutstat_inc(outif, type, code); 2225 2226 if (ia != NULL) 2227 ifa_free(&ia->ia_ifa); 2228 return; 2229 2230 bad: 2231 if (ia != NULL) 2232 ifa_free(&ia->ia_ifa); 2233 m_freem(m); 2234 return; 2235} 2236 2237void 2238icmp6_fasttimo(void) 2239{ 2240 2241 mld_fasttimo(); 2242} 2243 2244void 2245icmp6_slowtimo(void) 2246{ 2247 2248 mld_slowtimo(); 2249} 2250 2251static const char * 2252icmp6_redirect_diag(struct in6_addr *src6, struct in6_addr *dst6, 2253 struct in6_addr *tgt6) 2254{ 2255 static char buf[1024]; 2256 char ip6bufs[INET6_ADDRSTRLEN]; 2257 char ip6bufd[INET6_ADDRSTRLEN]; 2258 char ip6buft[INET6_ADDRSTRLEN]; 2259 snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)", 2260 ip6_sprintf(ip6bufs, src6), ip6_sprintf(ip6bufd, dst6), 2261 ip6_sprintf(ip6buft, tgt6)); 2262 return buf; 2263} 2264 2265void 2266icmp6_redirect_input(struct mbuf *m, int off) 2267{ 2268 INIT_VNET_INET6(curvnet); 2269 struct ifnet *ifp; 2270 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 2271 struct nd_redirect *nd_rd; 2272 int icmp6len = ntohs(ip6->ip6_plen); 2273 char *lladdr = NULL; 2274 int lladdrlen = 0; 2275 u_char *redirhdr = NULL; 2276 int redirhdrlen = 0; 2277 struct rtentry *rt = NULL; 2278 int is_router; 2279 int is_onlink; 2280 struct in6_addr src6 = ip6->ip6_src; 2281 struct in6_addr redtgt6; 2282 struct in6_addr reddst6; 2283 union nd_opts ndopts; 2284 char ip6buf[INET6_ADDRSTRLEN]; 2285 2286 if (!m) 2287 return; 2288 2289 ifp = m->m_pkthdr.rcvif; 2290 2291 if (!ifp) 2292 return; 2293 2294 /* XXX if we are router, we don't update route by icmp6 redirect */ 2295 if (V_ip6_forwarding) 2296 goto freeit; 2297 if (!V_icmp6_rediraccept) 2298 goto freeit; 2299 2300#ifndef PULLDOWN_TEST 2301 IP6_EXTHDR_CHECK(m, off, icmp6len,); 2302 nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off); 2303#else 2304 IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len); 2305 if (nd_rd == NULL) { 2306 ICMP6STAT_INC(icp6s_tooshort); 2307 return; 2308 } 2309#endif 2310 redtgt6 = nd_rd->nd_rd_target; 2311 reddst6 = nd_rd->nd_rd_dst; 2312 2313 if (in6_setscope(&redtgt6, m->m_pkthdr.rcvif, NULL) || 2314 in6_setscope(&reddst6, m->m_pkthdr.rcvif, NULL)) { 2315 goto freeit; 2316 } 2317 2318 /* validation */ 2319 if (!IN6_IS_ADDR_LINKLOCAL(&src6)) { 2320 nd6log((LOG_ERR, 2321 "ICMP6 redirect sent from %s rejected; " 2322 "must be from linklocal\n", 2323 ip6_sprintf(ip6buf, &src6))); 2324 goto bad; 2325 } 2326 if (ip6->ip6_hlim != 255) { 2327 nd6log((LOG_ERR, 2328 "ICMP6 redirect sent from %s rejected; " 2329 "hlim=%d (must be 255)\n", 2330 ip6_sprintf(ip6buf, &src6), ip6->ip6_hlim)); 2331 goto bad; 2332 } 2333 { 2334 /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */ 2335 struct sockaddr_in6 sin6; 2336 struct in6_addr *gw6; 2337 2338 bzero(&sin6, sizeof(sin6)); 2339 sin6.sin6_family = AF_INET6; 2340 sin6.sin6_len = sizeof(struct sockaddr_in6); 2341 bcopy(&reddst6, &sin6.sin6_addr, sizeof(reddst6)); 2342 rt = rtalloc1((struct sockaddr *)&sin6, 0, 0UL); 2343 if (rt) { 2344 if (rt->rt_gateway == NULL || 2345 rt->rt_gateway->sa_family != AF_INET6) { 2346 nd6log((LOG_ERR, 2347 "ICMP6 redirect rejected; no route " 2348 "with inet6 gateway found for redirect dst: %s\n", 2349 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2350 RTFREE_LOCKED(rt); 2351 goto bad; 2352 } 2353 2354 gw6 = &(((struct sockaddr_in6 *)rt->rt_gateway)->sin6_addr); 2355 if (bcmp(&src6, gw6, sizeof(struct in6_addr)) != 0) { 2356 nd6log((LOG_ERR, 2357 "ICMP6 redirect rejected; " 2358 "not equal to gw-for-src=%s (must be same): " 2359 "%s\n", 2360 ip6_sprintf(ip6buf, gw6), 2361 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2362 RTFREE_LOCKED(rt); 2363 goto bad; 2364 } 2365 } else { 2366 nd6log((LOG_ERR, 2367 "ICMP6 redirect rejected; " 2368 "no route found for redirect dst: %s\n", 2369 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2370 goto bad; 2371 } 2372 RTFREE_LOCKED(rt); 2373 rt = NULL; 2374 } 2375 if (IN6_IS_ADDR_MULTICAST(&reddst6)) { 2376 nd6log((LOG_ERR, 2377 "ICMP6 redirect rejected; " 2378 "redirect dst must be unicast: %s\n", 2379 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2380 goto bad; 2381 } 2382 2383 is_router = is_onlink = 0; 2384 if (IN6_IS_ADDR_LINKLOCAL(&redtgt6)) 2385 is_router = 1; /* router case */ 2386 if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0) 2387 is_onlink = 1; /* on-link destination case */ 2388 if (!is_router && !is_onlink) { 2389 nd6log((LOG_ERR, 2390 "ICMP6 redirect rejected; " 2391 "neither router case nor onlink case: %s\n", 2392 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2393 goto bad; 2394 } 2395 /* validation passed */ 2396 2397 icmp6len -= sizeof(*nd_rd); 2398 nd6_option_init(nd_rd + 1, icmp6len, &ndopts); 2399 if (nd6_options(&ndopts) < 0) { 2400 nd6log((LOG_INFO, "icmp6_redirect_input: " 2401 "invalid ND option, rejected: %s\n", 2402 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2403 /* nd6_options have incremented stats */ 2404 goto freeit; 2405 } 2406 2407 if (ndopts.nd_opts_tgt_lladdr) { 2408 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 2409 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 2410 } 2411 2412 if (ndopts.nd_opts_rh) { 2413 redirhdrlen = ndopts.nd_opts_rh->nd_opt_rh_len; 2414 redirhdr = (u_char *)(ndopts.nd_opts_rh + 1); /* xxx */ 2415 } 2416 2417 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 2418 nd6log((LOG_INFO, 2419 "icmp6_redirect_input: lladdrlen mismatch for %s " 2420 "(if %d, icmp6 packet %d): %s\n", 2421 ip6_sprintf(ip6buf, &redtgt6), 2422 ifp->if_addrlen, lladdrlen - 2, 2423 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2424 goto bad; 2425 } 2426 2427 /* RFC 2461 8.3 */ 2428 nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT, 2429 is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER); 2430 2431 if (!is_onlink) { /* better router case. perform rtredirect. */ 2432 /* perform rtredirect */ 2433 struct sockaddr_in6 sdst; 2434 struct sockaddr_in6 sgw; 2435 struct sockaddr_in6 ssrc; 2436 2437 bzero(&sdst, sizeof(sdst)); 2438 bzero(&sgw, sizeof(sgw)); 2439 bzero(&ssrc, sizeof(ssrc)); 2440 sdst.sin6_family = sgw.sin6_family = ssrc.sin6_family = AF_INET6; 2441 sdst.sin6_len = sgw.sin6_len = ssrc.sin6_len = 2442 sizeof(struct sockaddr_in6); 2443 bcopy(&redtgt6, &sgw.sin6_addr, sizeof(struct in6_addr)); 2444 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr)); 2445 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr)); 2446 rtredirect((struct sockaddr *)&sdst, (struct sockaddr *)&sgw, 2447 (struct sockaddr *)NULL, RTF_GATEWAY | RTF_HOST, 2448 (struct sockaddr *)&ssrc); 2449 } 2450 /* finally update cached route in each socket via pfctlinput */ 2451 { 2452 struct sockaddr_in6 sdst; 2453 2454 bzero(&sdst, sizeof(sdst)); 2455 sdst.sin6_family = AF_INET6; 2456 sdst.sin6_len = sizeof(struct sockaddr_in6); 2457 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr)); 2458 pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst); 2459#ifdef IPSEC 2460 key_sa_routechange((struct sockaddr *)&sdst); 2461#endif /* IPSEC */ 2462 } 2463 2464 freeit: 2465 m_freem(m); 2466 return; 2467 2468 bad: 2469 ICMP6STAT_INC(icp6s_badredirect); 2470 m_freem(m); 2471} 2472 2473void 2474icmp6_redirect_output(struct mbuf *m0, struct rtentry *rt) 2475{ 2476 INIT_VNET_INET6(curvnet); 2477 struct ifnet *ifp; /* my outgoing interface */ 2478 struct in6_addr *ifp_ll6; 2479 struct in6_addr *router_ll6; 2480 struct ip6_hdr *sip6; /* m0 as struct ip6_hdr */ 2481 struct mbuf *m = NULL; /* newly allocated one */ 2482 struct ip6_hdr *ip6; /* m as struct ip6_hdr */ 2483 struct nd_redirect *nd_rd; 2484 struct llentry *ln = NULL; 2485 size_t maxlen; 2486 u_char *p; 2487 struct ifnet *outif = NULL; 2488 struct sockaddr_in6 src_sa; 2489 2490 icmp6_errcount(&V_icmp6stat.icp6s_outerrhist, ND_REDIRECT, 0); 2491 2492 /* if we are not router, we don't send icmp6 redirect */ 2493 if (!V_ip6_forwarding) 2494 goto fail; 2495 2496 /* sanity check */ 2497 if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp)) 2498 goto fail; 2499 2500 /* 2501 * Address check: 2502 * the source address must identify a neighbor, and 2503 * the destination address must not be a multicast address 2504 * [RFC 2461, sec 8.2] 2505 */ 2506 sip6 = mtod(m0, struct ip6_hdr *); 2507 bzero(&src_sa, sizeof(src_sa)); 2508 src_sa.sin6_family = AF_INET6; 2509 src_sa.sin6_len = sizeof(src_sa); 2510 src_sa.sin6_addr = sip6->ip6_src; 2511 if (nd6_is_addr_neighbor(&src_sa, ifp) == 0) 2512 goto fail; 2513 if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst)) 2514 goto fail; /* what should we do here? */ 2515 2516 /* rate limit */ 2517 if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0)) 2518 goto fail; 2519 2520 /* 2521 * Since we are going to append up to 1280 bytes (= IPV6_MMTU), 2522 * we almost always ask for an mbuf cluster for simplicity. 2523 * (MHLEN < IPV6_MMTU is almost always true) 2524 */ 2525#if IPV6_MMTU >= MCLBYTES 2526# error assumption failed about IPV6_MMTU and MCLBYTES 2527#endif 2528 MGETHDR(m, M_DONTWAIT, MT_HEADER); 2529 if (m && IPV6_MMTU >= MHLEN) 2530 MCLGET(m, M_DONTWAIT); 2531 if (!m) 2532 goto fail; 2533 m->m_pkthdr.rcvif = NULL; 2534 m->m_len = 0; 2535 maxlen = M_TRAILINGSPACE(m); 2536 maxlen = min(IPV6_MMTU, maxlen); 2537 /* just for safety */ 2538 if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) + 2539 ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) { 2540 goto fail; 2541 } 2542 2543 { 2544 /* get ip6 linklocal address for ifp(my outgoing interface). */ 2545 struct in6_ifaddr *ia; 2546 if ((ia = in6ifa_ifpforlinklocal(ifp, 2547 IN6_IFF_NOTREADY| 2548 IN6_IFF_ANYCAST)) == NULL) 2549 goto fail; 2550 ifp_ll6 = &ia->ia_addr.sin6_addr; 2551 /* XXXRW: reference released prematurely. */ 2552 ifa_free(&ia->ia_ifa); 2553 } 2554 2555 /* get ip6 linklocal address for the router. */ 2556 if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) { 2557 struct sockaddr_in6 *sin6; 2558 sin6 = (struct sockaddr_in6 *)rt->rt_gateway; 2559 router_ll6 = &sin6->sin6_addr; 2560 if (!IN6_IS_ADDR_LINKLOCAL(router_ll6)) 2561 router_ll6 = (struct in6_addr *)NULL; 2562 } else 2563 router_ll6 = (struct in6_addr *)NULL; 2564 2565 /* ip6 */ 2566 ip6 = mtod(m, struct ip6_hdr *); 2567 ip6->ip6_flow = 0; 2568 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2569 ip6->ip6_vfc |= IPV6_VERSION; 2570 /* ip6->ip6_plen will be set later */ 2571 ip6->ip6_nxt = IPPROTO_ICMPV6; 2572 ip6->ip6_hlim = 255; 2573 /* ip6->ip6_src must be linklocal addr for my outgoing if. */ 2574 bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr)); 2575 bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr)); 2576 2577 /* ND Redirect */ 2578 nd_rd = (struct nd_redirect *)(ip6 + 1); 2579 nd_rd->nd_rd_type = ND_REDIRECT; 2580 nd_rd->nd_rd_code = 0; 2581 nd_rd->nd_rd_reserved = 0; 2582 if (rt->rt_flags & RTF_GATEWAY) { 2583 /* 2584 * nd_rd->nd_rd_target must be a link-local address in 2585 * better router cases. 2586 */ 2587 if (!router_ll6) 2588 goto fail; 2589 bcopy(router_ll6, &nd_rd->nd_rd_target, 2590 sizeof(nd_rd->nd_rd_target)); 2591 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2592 sizeof(nd_rd->nd_rd_dst)); 2593 } else { 2594 /* make sure redtgt == reddst */ 2595 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target, 2596 sizeof(nd_rd->nd_rd_target)); 2597 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2598 sizeof(nd_rd->nd_rd_dst)); 2599 } 2600 2601 p = (u_char *)(nd_rd + 1); 2602 2603 if (!router_ll6) 2604 goto nolladdropt; 2605 2606 { 2607 /* target lladdr option */ 2608 int len; 2609 struct nd_opt_hdr *nd_opt; 2610 char *lladdr; 2611 2612 IF_AFDATA_LOCK(ifp); 2613 ln = nd6_lookup(router_ll6, 0, ifp); 2614 IF_AFDATA_UNLOCK(ifp); 2615 if (ln == NULL) 2616 goto nolladdropt; 2617 2618 len = sizeof(*nd_opt) + ifp->if_addrlen; 2619 len = (len + 7) & ~7; /* round by 8 */ 2620 /* safety check */ 2621 if (len + (p - (u_char *)ip6) > maxlen) 2622 goto nolladdropt; 2623 2624 if (ln->la_flags & LLE_VALID) { 2625 nd_opt = (struct nd_opt_hdr *)p; 2626 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 2627 nd_opt->nd_opt_len = len >> 3; 2628 lladdr = (char *)(nd_opt + 1); 2629 bcopy(&ln->ll_addr, lladdr, ifp->if_addrlen); 2630 p += len; 2631 } 2632 } 2633nolladdropt: 2634 if (ln != NULL) 2635 LLE_RUNLOCK(ln); 2636 2637 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2638 2639 /* just to be safe */ 2640#ifdef M_DECRYPTED /*not openbsd*/ 2641 if (m0->m_flags & M_DECRYPTED) 2642 goto noredhdropt; 2643#endif 2644 if (p - (u_char *)ip6 > maxlen) 2645 goto noredhdropt; 2646 2647 { 2648 /* redirected header option */ 2649 int len; 2650 struct nd_opt_rd_hdr *nd_opt_rh; 2651 2652 /* 2653 * compute the maximum size for icmp6 redirect header option. 2654 * XXX room for auth header? 2655 */ 2656 len = maxlen - (p - (u_char *)ip6); 2657 len &= ~7; 2658 2659 /* This is just for simplicity. */ 2660 if (m0->m_pkthdr.len != m0->m_len) { 2661 if (m0->m_next) { 2662 m_freem(m0->m_next); 2663 m0->m_next = NULL; 2664 } 2665 m0->m_pkthdr.len = m0->m_len; 2666 } 2667 2668 /* 2669 * Redirected header option spec (RFC2461 4.6.3) talks nothing 2670 * about padding/truncate rule for the original IP packet. 2671 * From the discussion on IPv6imp in Feb 1999, 2672 * the consensus was: 2673 * - "attach as much as possible" is the goal 2674 * - pad if not aligned (original size can be guessed by 2675 * original ip6 header) 2676 * Following code adds the padding if it is simple enough, 2677 * and truncates if not. 2678 */ 2679 if (m0->m_next || m0->m_pkthdr.len != m0->m_len) 2680 panic("assumption failed in %s:%d", __FILE__, 2681 __LINE__); 2682 2683 if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) { 2684 /* not enough room, truncate */ 2685 m0->m_pkthdr.len = m0->m_len = len - 2686 sizeof(*nd_opt_rh); 2687 } else { 2688 /* enough room, pad or truncate */ 2689 size_t extra; 2690 2691 extra = m0->m_pkthdr.len % 8; 2692 if (extra) { 2693 /* pad if easy enough, truncate if not */ 2694 if (8 - extra <= M_TRAILINGSPACE(m0)) { 2695 /* pad */ 2696 m0->m_len += (8 - extra); 2697 m0->m_pkthdr.len += (8 - extra); 2698 } else { 2699 /* truncate */ 2700 m0->m_pkthdr.len -= extra; 2701 m0->m_len -= extra; 2702 } 2703 } 2704 len = m0->m_pkthdr.len + sizeof(*nd_opt_rh); 2705 m0->m_pkthdr.len = m0->m_len = len - 2706 sizeof(*nd_opt_rh); 2707 } 2708 2709 nd_opt_rh = (struct nd_opt_rd_hdr *)p; 2710 bzero(nd_opt_rh, sizeof(*nd_opt_rh)); 2711 nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER; 2712 nd_opt_rh->nd_opt_rh_len = len >> 3; 2713 p += sizeof(*nd_opt_rh); 2714 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2715 2716 /* connect m0 to m */ 2717 m_tag_delete_chain(m0, NULL); 2718 m0->m_flags &= ~M_PKTHDR; 2719 m->m_next = m0; 2720 m->m_pkthdr.len = m->m_len + m0->m_len; 2721 m0 = NULL; 2722 } 2723noredhdropt:; 2724 if (m0) { 2725 m_freem(m0); 2726 m0 = NULL; 2727 } 2728 2729 /* XXX: clear embedded link IDs in the inner header */ 2730 in6_clearscope(&sip6->ip6_src); 2731 in6_clearscope(&sip6->ip6_dst); 2732 in6_clearscope(&nd_rd->nd_rd_target); 2733 in6_clearscope(&nd_rd->nd_rd_dst); 2734 2735 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr)); 2736 2737 nd_rd->nd_rd_cksum = 0; 2738 nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2739 sizeof(*ip6), ntohs(ip6->ip6_plen)); 2740 2741 /* send the packet to outside... */ 2742 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2743 if (outif) { 2744 icmp6_ifstat_inc(outif, ifs6_out_msg); 2745 icmp6_ifstat_inc(outif, ifs6_out_redirect); 2746 } 2747 ICMP6STAT_INC(icp6s_outhist[ND_REDIRECT]); 2748 2749 return; 2750 2751fail: 2752 if (m) 2753 m_freem(m); 2754 if (m0) 2755 m_freem(m0); 2756} 2757 2758/* 2759 * ICMPv6 socket option processing. 2760 */ 2761int 2762icmp6_ctloutput(struct socket *so, struct sockopt *sopt) 2763{ 2764 int error = 0; 2765 int optlen; 2766 struct inpcb *inp = sotoinpcb(so); 2767 int level, op, optname; 2768 2769 if (sopt) { 2770 level = sopt->sopt_level; 2771 op = sopt->sopt_dir; 2772 optname = sopt->sopt_name; 2773 optlen = sopt->sopt_valsize; 2774 } else 2775 level = op = optname = optlen = 0; 2776 2777 if (level != IPPROTO_ICMPV6) { 2778 return EINVAL; 2779 } 2780 2781 switch (op) { 2782 case PRCO_SETOPT: 2783 switch (optname) { 2784 case ICMP6_FILTER: 2785 { 2786 struct icmp6_filter ic6f; 2787 2788 if (optlen != sizeof(ic6f)) { 2789 error = EMSGSIZE; 2790 break; 2791 } 2792 error = sooptcopyin(sopt, &ic6f, optlen, optlen); 2793 if (error == 0) { 2794 INP_WLOCK(inp); 2795 *inp->in6p_icmp6filt = ic6f; 2796 INP_WUNLOCK(inp); 2797 } 2798 break; 2799 } 2800 2801 default: 2802 error = ENOPROTOOPT; 2803 break; 2804 } 2805 break; 2806 2807 case PRCO_GETOPT: 2808 switch (optname) { 2809 case ICMP6_FILTER: 2810 { 2811 struct icmp6_filter ic6f; 2812 2813 INP_RLOCK(inp); 2814 ic6f = *inp->in6p_icmp6filt; 2815 INP_RUNLOCK(inp); 2816 error = sooptcopyout(sopt, &ic6f, sizeof(ic6f)); 2817 break; 2818 } 2819 2820 default: 2821 error = ENOPROTOOPT; 2822 break; 2823 } 2824 break; 2825 } 2826 2827 return (error); 2828} 2829 2830/* 2831 * Perform rate limit check. 2832 * Returns 0 if it is okay to send the icmp6 packet. 2833 * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate 2834 * limitation. 2835 * 2836 * XXX per-destination/type check necessary? 2837 * 2838 * dst - not used at this moment 2839 * type - not used at this moment 2840 * code - not used at this moment 2841 */ 2842static int 2843icmp6_ratelimit(const struct in6_addr *dst, const int type, 2844 const int code) 2845{ 2846 INIT_VNET_INET6(curvnet); 2847 int ret; 2848 2849 ret = 0; /* okay to send */ 2850 2851 /* PPS limit */ 2852 if (!ppsratecheck(&V_icmp6errppslim_last, &V_icmp6errpps_count, 2853 V_icmp6errppslim)) { 2854 /* The packet is subject to rate limit */ 2855 ret++; 2856 } 2857 2858 return ret; 2859} 2860