1 /* $FreeBSD$ */ 2 /* $KAME: icmp6.c,v 1.211 2001/04/04 05:56:20 itojun Exp $ */ 3 4 /*- 5 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the project nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 /*- 34 * Copyright (c) 1982, 1986, 1988, 1993 35 * The Regents of the University of California. All rights reserved. 36 * 37 * Redistribution and use in source and binary forms, with or without 38 * modification, are permitted provided that the following conditions 39 * are met: 40 * 1. Redistributions of source code must retain the above copyright 41 * notice, this list of conditions and the following disclaimer. 42 * 2. Redistributions in binary form must reproduce the above copyright 43 * notice, this list of conditions and the following disclaimer in the 44 * documentation and/or other materials provided with the distribution. 45 * 4. Neither the name of the University nor the names of its contributors 46 * may be used to endorse or promote products derived from this software 47 * without specific prior written permission. 48 * 49 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 50 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 51 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 52 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 53 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 54 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 55 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 56 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 57 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 58 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 59 * SUCH DAMAGE. 60 * 61 * @(#)ip_icmp.c 8.2 (Berkeley) 1/4/94 62 */ 63 64 #include "opt_inet.h" 65 #include "opt_inet6.h" 66 #include "opt_ipsec.h" 67 68 #include <sys/param.h> 69 #include <sys/domain.h> 70 #include <sys/kernel.h> 71 #include <sys/lock.h> 72 #include <sys/malloc.h> 73 #include <sys/mbuf.h> 74 #include <sys/protosw.h> 75 #include <sys/signalvar.h> 76 #include <sys/socket.h> 77 #include <sys/socketvar.h> 78 #include <sys/sx.h> 79 #include <sys/syslog.h> 80 #include <sys/systm.h> 81 #include <sys/time.h> 82 83 #include <net/if.h> 84 #include <net/if_dl.h> 85 #include <net/if_types.h> 86 #include <net/route.h> 87 88 #include <netinet/in.h> 89 #include <netinet/in_pcb.h> 90 #include <netinet/in_var.h> 91 #include <netinet/ip6.h> 92 #include <netinet/icmp6.h> 93 #include <netinet/tcp_var.h> 94 #include <netinet6/in6_ifattach.h> 95 #include <netinet6/in6_pcb.h> 96 #include <netinet6/ip6protosw.h> 97 #include <netinet6/ip6_var.h> 98 #include <netinet6/mld6_var.h> 99 #include <netinet6/nd6.h> 100 101 #ifdef IPSEC 102 #include <netinet6/ipsec.h> 103 #include <netkey/key.h> 104 #endif 105 106 #ifdef FAST_IPSEC 107 #include <netipsec/ipsec.h> 108 #include <netipsec/key.h> 109 #endif 110 111 #include <net/net_osdep.h> 112 113 extern struct domain inet6domain; 114 115 struct icmp6stat icmp6stat; 116 117 extern struct inpcbinfo ripcbinfo; 118 extern struct inpcbhead ripcb; 119 extern int icmp6errppslim; 120 static int icmp6errpps_count = 0; 121 static struct timeval icmp6errppslim_last; 122 extern int icmp6_nodeinfo; 123 124 static void icmp6_errcount __P((struct icmp6errstat *, int, int)); 125 static int icmp6_rip6_input __P((struct mbuf **, int)); 126 static int icmp6_ratelimit __P((const struct in6_addr *, const int, const int)); 127 static const char *icmp6_redirect_diag __P((struct in6_addr *, 128 struct in6_addr *, struct in6_addr *)); 129 static struct mbuf *ni6_input __P((struct mbuf *, int)); 130 static struct mbuf *ni6_nametodns __P((const char *, int, int)); 131 static int ni6_dnsmatch __P((const char *, int, const char *, int)); 132 static int ni6_addrs __P((struct icmp6_nodeinfo *, struct mbuf *, 133 struct ifnet **, char *)); 134 static int ni6_store_addrs __P((struct icmp6_nodeinfo *, struct icmp6_nodeinfo *, 135 struct ifnet *, int)); 136 static int icmp6_notify_error __P((struct mbuf **, int, int, int)); 137 138 #ifdef COMPAT_RFC1885 139 static struct route_in6 icmp6_reflect_rt; 140 #endif 141 142 143 void 144 icmp6_init() 145 { 146 mld6_init(); 147 } 148 149 static void 150 icmp6_errcount(stat, type, code) 151 struct icmp6errstat *stat; 152 int type, code; 153 { 154 switch (type) { 155 case ICMP6_DST_UNREACH: 156 switch (code) { 157 case ICMP6_DST_UNREACH_NOROUTE: 158 stat->icp6errs_dst_unreach_noroute++; 159 return; 160 case ICMP6_DST_UNREACH_ADMIN: 161 stat->icp6errs_dst_unreach_admin++; 162 return; 163 case ICMP6_DST_UNREACH_BEYONDSCOPE: 164 stat->icp6errs_dst_unreach_beyondscope++; 165 return; 166 case ICMP6_DST_UNREACH_ADDR: 167 stat->icp6errs_dst_unreach_addr++; 168 return; 169 case ICMP6_DST_UNREACH_NOPORT: 170 stat->icp6errs_dst_unreach_noport++; 171 return; 172 } 173 break; 174 case ICMP6_PACKET_TOO_BIG: 175 stat->icp6errs_packet_too_big++; 176 return; 177 case ICMP6_TIME_EXCEEDED: 178 switch (code) { 179 case ICMP6_TIME_EXCEED_TRANSIT: 180 stat->icp6errs_time_exceed_transit++; 181 return; 182 case ICMP6_TIME_EXCEED_REASSEMBLY: 183 stat->icp6errs_time_exceed_reassembly++; 184 return; 185 } 186 break; 187 case ICMP6_PARAM_PROB: 188 switch (code) { 189 case ICMP6_PARAMPROB_HEADER: 190 stat->icp6errs_paramprob_header++; 191 return; 192 case ICMP6_PARAMPROB_NEXTHEADER: 193 stat->icp6errs_paramprob_nextheader++; 194 return; 195 case ICMP6_PARAMPROB_OPTION: 196 stat->icp6errs_paramprob_option++; 197 return; 198 } 199 break; 200 case ND_REDIRECT: 201 stat->icp6errs_redirect++; 202 return; 203 } 204 stat->icp6errs_unknown++; 205 } 206 207 /* 208 * Generate an error packet of type error in response to bad IP6 packet. 209 */ 210 void 211 icmp6_error(m, type, code, param) 212 struct mbuf *m; 213 int type, code, param; 214 { 215 struct ip6_hdr *oip6, *nip6; 216 struct icmp6_hdr *icmp6; 217 u_int preplen; 218 int off; 219 int nxt; 220 221 icmp6stat.icp6s_error++; 222 223 /* count per-type-code statistics */ 224 icmp6_errcount(&icmp6stat.icp6s_outerrhist, type, code); 225 226 #ifdef M_DECRYPTED /*not openbsd*/ 227 if (m->m_flags & M_DECRYPTED) { 228 icmp6stat.icp6s_canterror++; 229 goto freeit; 230 } 231 #endif 232 233 #ifndef PULLDOWN_TEST 234 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), ); 235 #else 236 if (m->m_len < sizeof(struct ip6_hdr)) { 237 m = m_pullup(m, sizeof(struct ip6_hdr)); 238 if (m == NULL) 239 return; 240 } 241 #endif 242 oip6 = mtod(m, struct ip6_hdr *); 243 244 /* 245 * If the destination address of the erroneous packet is a multicast 246 * address, or the packet was sent using link-layer multicast, 247 * we should basically suppress sending an error (RFC 2463, Section 248 * 2.4). 249 * We have two exceptions (the item e.2 in that section): 250 * - the Pakcet Too Big message can be sent for path MTU discovery. 251 * - the Parameter Problem Message that can be allowed an icmp6 error 252 * in the option type field. This check has been done in 253 * ip6_unknown_opt(), so we can just check the type and code. 254 */ 255 if ((m->m_flags & (M_BCAST|M_MCAST) || 256 IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) && 257 (type != ICMP6_PACKET_TOO_BIG && 258 (type != ICMP6_PARAM_PROB || 259 code != ICMP6_PARAMPROB_OPTION))) 260 goto freeit; 261 262 /* 263 * RFC 2463, 2.4 (e.5): source address check. 264 * XXX: the case of anycast source? 265 */ 266 if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) || 267 IN6_IS_ADDR_MULTICAST(&oip6->ip6_src)) 268 goto freeit; 269 270 /* 271 * If we are about to send ICMPv6 against ICMPv6 error/redirect, 272 * don't do it. 273 */ 274 nxt = -1; 275 off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt); 276 if (off >= 0 && nxt == IPPROTO_ICMPV6) { 277 struct icmp6_hdr *icp; 278 279 #ifndef PULLDOWN_TEST 280 IP6_EXTHDR_CHECK(m, 0, off + sizeof(struct icmp6_hdr), ); 281 icp = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 282 #else 283 IP6_EXTHDR_GET(icp, struct icmp6_hdr *, m, off, 284 sizeof(*icp)); 285 if (icp == NULL) { 286 icmp6stat.icp6s_tooshort++; 287 return; 288 } 289 #endif 290 if (icp->icmp6_type < ICMP6_ECHO_REQUEST || 291 icp->icmp6_type == ND_REDIRECT) { 292 /* 293 * ICMPv6 error 294 * Special case: for redirect (which is 295 * informational) we must not send icmp6 error. 296 */ 297 icmp6stat.icp6s_canterror++; 298 goto freeit; 299 } else { 300 /* ICMPv6 informational - send the error */ 301 } 302 } else { 303 /* non-ICMPv6 - send the error */ 304 } 305 306 oip6 = mtod(m, struct ip6_hdr *); /* adjust pointer */ 307 308 /* Finally, do rate limitation check. */ 309 if (icmp6_ratelimit(&oip6->ip6_src, type, code)) { 310 icmp6stat.icp6s_toofreq++; 311 goto freeit; 312 } 313 314 /* 315 * OK, ICMP6 can be generated. 316 */ 317 318 if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN) 319 m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len); 320 321 preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 322 M_PREPEND(m, preplen, M_DONTWAIT); 323 if (m && m->m_len < preplen) 324 m = m_pullup(m, preplen); 325 if (m == NULL) { 326 nd6log((LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__)); 327 return; 328 } 329 330 nip6 = mtod(m, struct ip6_hdr *); 331 nip6->ip6_src = oip6->ip6_src; 332 nip6->ip6_dst = oip6->ip6_dst; 333 334 in6_clearscope(&oip6->ip6_src); 335 in6_clearscope(&oip6->ip6_dst); 336 337 icmp6 = (struct icmp6_hdr *)(nip6 + 1); 338 icmp6->icmp6_type = type; 339 icmp6->icmp6_code = code; 340 icmp6->icmp6_pptr = htonl((u_int32_t)param); 341 342 /* 343 * icmp6_reflect() is designed to be in the input path. 344 * icmp6_error() can be called from both input and outut path, 345 * and if we are in output path rcvif could contain bogus value. 346 * clear m->m_pkthdr.rcvif for safety, we should have enough scope 347 * information in ip header (nip6). 348 */ 349 m->m_pkthdr.rcvif = NULL; 350 351 icmp6stat.icp6s_outhist[type]++; 352 icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */ 353 354 return; 355 356 freeit: 357 /* 358 * If we can't tell wheter or not we can generate ICMP6, free it. 359 */ 360 m_freem(m); 361 } 362 363 /* 364 * Process a received ICMP6 message. 365 */ 366 int 367 icmp6_input(mp, offp, proto) 368 struct mbuf **mp; 369 int *offp, proto; 370 { 371 struct mbuf *m = *mp, *n; 372 struct ip6_hdr *ip6, *nip6; 373 struct icmp6_hdr *icmp6, *nicmp6; 374 int off = *offp; 375 int icmp6len = m->m_pkthdr.len - *offp; 376 int code, sum, noff; 377 378 #ifndef PULLDOWN_TEST 379 IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_hdr), IPPROTO_DONE); 380 /* m might change if M_LOOP. So, call mtod after this */ 381 #endif 382 383 /* 384 * Locate icmp6 structure in mbuf, and check 385 * that not corrupted and of at least minimum length 386 */ 387 388 ip6 = mtod(m, struct ip6_hdr *); 389 if (icmp6len < sizeof(struct icmp6_hdr)) { 390 icmp6stat.icp6s_tooshort++; 391 goto freeit; 392 } 393 394 /* 395 * calculate the checksum 396 */ 397 #ifndef PULLDOWN_TEST 398 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off); 399 #else 400 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6)); 401 if (icmp6 == NULL) { 402 icmp6stat.icp6s_tooshort++; 403 return IPPROTO_DONE; 404 } 405 #endif 406 code = icmp6->icmp6_code; 407 408 if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) { 409 nd6log((LOG_ERR, 410 "ICMP6 checksum error(%d|%x) %s\n", 411 icmp6->icmp6_type, sum, ip6_sprintf(&ip6->ip6_src))); 412 icmp6stat.icp6s_checksum++; 413 goto freeit; 414 } 415 416 if (faithprefix_p != NULL && (*faithprefix_p)(&ip6->ip6_dst)) { 417 /* 418 * Deliver very specific ICMP6 type only. 419 * This is important to deilver TOOBIG. Otherwise PMTUD 420 * will not work. 421 */ 422 switch (icmp6->icmp6_type) { 423 case ICMP6_DST_UNREACH: 424 case ICMP6_PACKET_TOO_BIG: 425 case ICMP6_TIME_EXCEEDED: 426 break; 427 default: 428 goto freeit; 429 } 430 } 431 432 icmp6stat.icp6s_inhist[icmp6->icmp6_type]++; 433 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_msg); 434 if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK) 435 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_error); 436 437 switch (icmp6->icmp6_type) { 438 case ICMP6_DST_UNREACH: 439 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_dstunreach); 440 switch (code) { 441 case ICMP6_DST_UNREACH_NOROUTE: 442 code = PRC_UNREACH_NET; 443 break; 444 case ICMP6_DST_UNREACH_ADMIN: 445 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_adminprohib); 446 code = PRC_UNREACH_PROTOCOL; /* is this a good code? */ 447 break; 448 case ICMP6_DST_UNREACH_ADDR: 449 code = PRC_HOSTDEAD; 450 break; 451 #ifdef COMPAT_RFC1885 452 case ICMP6_DST_UNREACH_NOTNEIGHBOR: 453 code = PRC_UNREACH_SRCFAIL; 454 break; 455 #else 456 case ICMP6_DST_UNREACH_BEYONDSCOPE: 457 /* I mean "source address was incorrect." */ 458 code = PRC_PARAMPROB; 459 break; 460 #endif 461 case ICMP6_DST_UNREACH_NOPORT: 462 code = PRC_UNREACH_PORT; 463 break; 464 default: 465 goto badcode; 466 } 467 goto deliver; 468 break; 469 470 case ICMP6_PACKET_TOO_BIG: 471 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_pkttoobig); 472 473 /* validation is made in icmp6_mtudisc_update */ 474 475 code = PRC_MSGSIZE; 476 477 /* 478 * Updating the path MTU will be done after examining 479 * intermediate extension headers. 480 */ 481 goto deliver; 482 break; 483 484 case ICMP6_TIME_EXCEEDED: 485 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_timeexceed); 486 switch (code) { 487 case ICMP6_TIME_EXCEED_TRANSIT: 488 case ICMP6_TIME_EXCEED_REASSEMBLY: 489 code += PRC_TIMXCEED_INTRANS; 490 break; 491 default: 492 goto badcode; 493 } 494 goto deliver; 495 break; 496 497 case ICMP6_PARAM_PROB: 498 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_paramprob); 499 switch (code) { 500 case ICMP6_PARAMPROB_NEXTHEADER: 501 code = PRC_UNREACH_PROTOCOL; 502 break; 503 case ICMP6_PARAMPROB_HEADER: 504 case ICMP6_PARAMPROB_OPTION: 505 code = PRC_PARAMPROB; 506 break; 507 default: 508 goto badcode; 509 } 510 goto deliver; 511 break; 512 513 case ICMP6_ECHO_REQUEST: 514 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_echo); 515 if (code != 0) 516 goto badcode; 517 if ((n = m_copy(m, 0, M_COPYALL)) == NULL) { 518 /* Give up remote */ 519 break; 520 } 521 if ((n->m_flags & M_EXT) != 0 522 || n->m_len < off + sizeof(struct icmp6_hdr)) { 523 struct mbuf *n0 = n; 524 const int maxlen = sizeof(*nip6) + sizeof(*nicmp6); 525 int n0len; 526 527 MGETHDR(n, M_DONTWAIT, n0->m_type); 528 n0len = n0->m_pkthdr.len; /* save for use below */ 529 if (n) 530 M_MOVE_PKTHDR(n, n0); 531 if (n && maxlen >= MHLEN) { 532 MCLGET(n, M_DONTWAIT); 533 if ((n->m_flags & M_EXT) == 0) { 534 m_free(n); 535 n = NULL; 536 } 537 } 538 if (n == NULL) { 539 /* Give up remote */ 540 m_freem(n0); 541 break; 542 } 543 /* 544 * Copy IPv6 and ICMPv6 only. 545 */ 546 nip6 = mtod(n, struct ip6_hdr *); 547 bcopy(ip6, nip6, sizeof(struct ip6_hdr)); 548 nicmp6 = (struct icmp6_hdr *)(nip6 + 1); 549 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr)); 550 noff = sizeof(struct ip6_hdr); 551 /* new mbuf contains only ipv6+icmpv6 headers */ 552 n->m_len = noff + sizeof(struct icmp6_hdr); 553 /* 554 * Adjust mbuf. ip6_plen will be adjusted in 555 * ip6_output(). 556 */ 557 m_adj(n0, off + sizeof(struct icmp6_hdr)); 558 /* recalculate complete packet size */ 559 n->m_pkthdr.len = n0len + (noff - off); 560 n->m_next = n0; 561 } else { 562 nip6 = mtod(n, struct ip6_hdr *); 563 nicmp6 = (struct icmp6_hdr *)((caddr_t)nip6 + off); 564 noff = off; 565 } 566 nicmp6->icmp6_type = ICMP6_ECHO_REPLY; 567 nicmp6->icmp6_code = 0; 568 if (n) { 569 icmp6stat.icp6s_reflect++; 570 icmp6stat.icp6s_outhist[ICMP6_ECHO_REPLY]++; 571 icmp6_reflect(n, noff); 572 } 573 break; 574 575 case ICMP6_ECHO_REPLY: 576 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_echoreply); 577 if (code != 0) 578 goto badcode; 579 break; 580 581 case MLD_LISTENER_QUERY: 582 case MLD_LISTENER_REPORT: 583 if (icmp6len < sizeof(struct mld_hdr)) 584 goto badlen; 585 if (icmp6->icmp6_type == MLD_LISTENER_QUERY) /* XXX: ugly... */ 586 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mldquery); 587 else 588 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mldreport); 589 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 590 /* give up local */ 591 mld6_input(m, off); 592 m = NULL; 593 goto freeit; 594 } 595 mld6_input(n, off); 596 /* m stays. */ 597 break; 598 599 case MLD_LISTENER_DONE: 600 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mlddone); 601 if (icmp6len < sizeof(struct mld_hdr)) /* necessary? */ 602 goto badlen; 603 break; /* nothing to be done in kernel */ 604 605 case MLD_MTRACE_RESP: 606 case MLD_MTRACE: 607 /* XXX: these two are experimental. not officially defined. */ 608 /* XXX: per-interface statistics? */ 609 break; /* just pass it to applications */ 610 611 case ICMP6_WRUREQUEST: /* ICMP6_FQDN_QUERY */ 612 { 613 enum { WRU, FQDN } mode; 614 615 if (!icmp6_nodeinfo) 616 break; 617 618 if (icmp6len == sizeof(struct icmp6_hdr) + 4) 619 mode = WRU; 620 else if (icmp6len >= sizeof(struct icmp6_nodeinfo)) 621 mode = FQDN; 622 else 623 goto badlen; 624 625 #define hostnamelen strlen(hostname) 626 if (mode == FQDN) { 627 #ifndef PULLDOWN_TEST 628 IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_nodeinfo), 629 IPPROTO_DONE); 630 #endif 631 n = m_copy(m, 0, M_COPYALL); 632 if (n) 633 n = ni6_input(n, off); 634 /* XXX meaningless if n == NULL */ 635 noff = sizeof(struct ip6_hdr); 636 } else { 637 u_char *p; 638 int maxlen, maxhlen; 639 640 if ((icmp6_nodeinfo & 5) != 5) 641 break; 642 643 if (code != 0) 644 goto badcode; 645 maxlen = sizeof(*nip6) + sizeof(*nicmp6) + 4; 646 if (maxlen >= MCLBYTES) { 647 /* Give up remote */ 648 break; 649 } 650 MGETHDR(n, M_DONTWAIT, m->m_type); 651 if (n && maxlen > MHLEN) { 652 MCLGET(n, M_DONTWAIT); 653 if ((n->m_flags & M_EXT) == 0) { 654 m_free(n); 655 n = NULL; 656 } 657 } 658 if (!m_dup_pkthdr(n, m, M_DONTWAIT)) { 659 /* 660 * Previous code did a blind M_COPY_PKTHDR 661 * and said "just for rcvif". If true, then 662 * we could tolerate the dup failing (due to 663 * the deep copy of the tag chain). For now 664 * be conservative and just fail. 665 */ 666 m_free(n); 667 n = NULL; 668 } 669 if (n == NULL) { 670 /* Give up remote */ 671 break; 672 } 673 n->m_pkthdr.rcvif = NULL; 674 n->m_len = 0; 675 maxhlen = M_TRAILINGSPACE(n) - maxlen; 676 if (maxhlen > hostnamelen) 677 maxhlen = hostnamelen; 678 /* 679 * Copy IPv6 and ICMPv6 only. 680 */ 681 nip6 = mtod(n, struct ip6_hdr *); 682 bcopy(ip6, nip6, sizeof(struct ip6_hdr)); 683 nicmp6 = (struct icmp6_hdr *)(nip6 + 1); 684 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr)); 685 p = (u_char *)(nicmp6 + 1); 686 bzero(p, 4); 687 bcopy(hostname, p + 4, maxhlen); /* meaningless TTL */ 688 noff = sizeof(struct ip6_hdr); 689 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + 690 sizeof(struct icmp6_hdr) + 4 + maxhlen; 691 nicmp6->icmp6_type = ICMP6_WRUREPLY; 692 nicmp6->icmp6_code = 0; 693 } 694 #undef hostnamelen 695 if (n) { 696 icmp6stat.icp6s_reflect++; 697 icmp6stat.icp6s_outhist[ICMP6_WRUREPLY]++; 698 icmp6_reflect(n, noff); 699 } 700 break; 701 } 702 703 case ICMP6_WRUREPLY: 704 if (code != 0) 705 goto badcode; 706 break; 707 708 case ND_ROUTER_SOLICIT: 709 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_routersolicit); 710 if (code != 0) 711 goto badcode; 712 if (icmp6len < sizeof(struct nd_router_solicit)) 713 goto badlen; 714 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 715 /* give up local */ 716 nd6_rs_input(m, off, icmp6len); 717 m = NULL; 718 goto freeit; 719 } 720 nd6_rs_input(n, off, icmp6len); 721 /* m stays. */ 722 break; 723 724 case ND_ROUTER_ADVERT: 725 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_routeradvert); 726 if (code != 0) 727 goto badcode; 728 if (icmp6len < sizeof(struct nd_router_advert)) 729 goto badlen; 730 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 731 /* give up local */ 732 nd6_ra_input(m, off, icmp6len); 733 m = NULL; 734 goto freeit; 735 } 736 nd6_ra_input(n, off, icmp6len); 737 /* m stays. */ 738 break; 739 740 case ND_NEIGHBOR_SOLICIT: 741 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_neighborsolicit); 742 if (code != 0) 743 goto badcode; 744 if (icmp6len < sizeof(struct nd_neighbor_solicit)) 745 goto badlen; 746 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 747 /* give up local */ 748 nd6_ns_input(m, off, icmp6len); 749 m = NULL; 750 goto freeit; 751 } 752 nd6_ns_input(n, off, icmp6len); 753 /* m stays. */ 754 break; 755 756 case ND_NEIGHBOR_ADVERT: 757 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_neighboradvert); 758 if (code != 0) 759 goto badcode; 760 if (icmp6len < sizeof(struct nd_neighbor_advert)) 761 goto badlen; 762 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 763 /* give up local */ 764 nd6_na_input(m, off, icmp6len); 765 m = NULL; 766 goto freeit; 767 } 768 nd6_na_input(n, off, icmp6len); 769 /* m stays. */ 770 break; 771 772 case ND_REDIRECT: 773 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_redirect); 774 if (code != 0) 775 goto badcode; 776 if (icmp6len < sizeof(struct nd_redirect)) 777 goto badlen; 778 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 779 /* give up local */ 780 icmp6_redirect_input(m, off); 781 m = NULL; 782 goto freeit; 783 } 784 icmp6_redirect_input(n, off); 785 /* m stays. */ 786 break; 787 788 case ICMP6_ROUTER_RENUMBERING: 789 if (code != ICMP6_ROUTER_RENUMBERING_COMMAND && 790 code != ICMP6_ROUTER_RENUMBERING_RESULT) 791 goto badcode; 792 if (icmp6len < sizeof(struct icmp6_router_renum)) 793 goto badlen; 794 break; 795 796 default: 797 nd6log((LOG_DEBUG, 798 "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n", 799 icmp6->icmp6_type, ip6_sprintf(&ip6->ip6_src), 800 ip6_sprintf(&ip6->ip6_dst), 801 m->m_pkthdr.rcvif ? m->m_pkthdr.rcvif->if_index : 0)); 802 if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) { 803 /* ICMPv6 error: MUST deliver it by spec... */ 804 code = PRC_NCMDS; 805 /* deliver */ 806 } else { 807 /* ICMPv6 informational: MUST not deliver */ 808 break; 809 } 810 deliver: 811 if (icmp6_notify_error(&m, off, icmp6len, code)) { 812 /* In this case, m should've been freed. */ 813 return (IPPROTO_DONE); 814 } 815 break; 816 817 badcode: 818 icmp6stat.icp6s_badcode++; 819 break; 820 821 badlen: 822 icmp6stat.icp6s_badlen++; 823 break; 824 } 825 826 /* deliver the packet to appropriate sockets */ 827 icmp6_rip6_input(&m, *offp); 828 829 return IPPROTO_DONE; 830 831 freeit: 832 m_freem(m); 833 return IPPROTO_DONE; 834 } 835 836 static int 837 icmp6_notify_error(mp, off, icmp6len, code) 838 struct mbuf **mp; 839 int off, icmp6len, code; 840 { 841 struct mbuf *m = *mp; 842 struct icmp6_hdr *icmp6; 843 struct ip6_hdr *eip6; 844 u_int32_t notifymtu; 845 struct sockaddr_in6 icmp6src, icmp6dst; 846 847 if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) { 848 icmp6stat.icp6s_tooshort++; 849 goto freeit; 850 } 851 #ifndef PULLDOWN_TEST 852 IP6_EXTHDR_CHECK(m, off, 853 sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr), -1); 854 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 855 #else 856 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, 857 sizeof(*icmp6) + sizeof(struct ip6_hdr)); 858 if (icmp6 == NULL) { 859 icmp6stat.icp6s_tooshort++; 860 return (-1); 861 } 862 #endif 863 eip6 = (struct ip6_hdr *)(icmp6 + 1); 864 865 /* Detect the upper level protocol */ 866 { 867 void (*ctlfunc) __P((int, struct sockaddr *, void *)); 868 u_int8_t nxt = eip6->ip6_nxt; 869 int eoff = off + sizeof(struct icmp6_hdr) + 870 sizeof(struct ip6_hdr); 871 struct ip6ctlparam ip6cp; 872 struct in6_addr *finaldst = NULL; 873 int icmp6type = icmp6->icmp6_type; 874 struct ip6_frag *fh; 875 struct ip6_rthdr *rth; 876 struct ip6_rthdr0 *rth0; 877 int rthlen; 878 879 while (1) { /* XXX: should avoid infinite loop explicitly? */ 880 struct ip6_ext *eh; 881 882 switch (nxt) { 883 case IPPROTO_HOPOPTS: 884 case IPPROTO_DSTOPTS: 885 case IPPROTO_AH: 886 #ifndef PULLDOWN_TEST 887 IP6_EXTHDR_CHECK(m, 0, 888 eoff + sizeof(struct ip6_ext), -1); 889 eh = (struct ip6_ext *)(mtod(m, caddr_t) + eoff); 890 #else 891 IP6_EXTHDR_GET(eh, struct ip6_ext *, m, 892 eoff, sizeof(*eh)); 893 if (eh == NULL) { 894 icmp6stat.icp6s_tooshort++; 895 return (-1); 896 } 897 #endif 898 899 if (nxt == IPPROTO_AH) 900 eoff += (eh->ip6e_len + 2) << 2; 901 else 902 eoff += (eh->ip6e_len + 1) << 3; 903 nxt = eh->ip6e_nxt; 904 break; 905 case IPPROTO_ROUTING: 906 /* 907 * When the erroneous packet contains a 908 * routing header, we should examine the 909 * header to determine the final destination. 910 * Otherwise, we can't properly update 911 * information that depends on the final 912 * destination (e.g. path MTU). 913 */ 914 #ifndef PULLDOWN_TEST 915 IP6_EXTHDR_CHECK(m, 0, eoff + sizeof(*rth), -1); 916 rth = (struct ip6_rthdr *) 917 (mtod(m, caddr_t) + eoff); 918 #else 919 IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m, 920 eoff, sizeof(*rth)); 921 if (rth == NULL) { 922 icmp6stat.icp6s_tooshort++; 923 return (-1); 924 } 925 #endif 926 rthlen = (rth->ip6r_len + 1) << 3; 927 /* 928 * XXX: currently there is no 929 * officially defined type other 930 * than type-0. 931 * Note that if the segment left field 932 * is 0, all intermediate hops must 933 * have been passed. 934 */ 935 if (rth->ip6r_segleft && 936 rth->ip6r_type == IPV6_RTHDR_TYPE_0) { 937 int hops; 938 939 #ifndef PULLDOWN_TEST 940 IP6_EXTHDR_CHECK(m, 0, eoff + rthlen, -1); 941 rth0 = (struct ip6_rthdr0 *) 942 (mtod(m, caddr_t) + eoff); 943 #else 944 IP6_EXTHDR_GET(rth0, 945 struct ip6_rthdr0 *, m, 946 eoff, rthlen); 947 if (rth0 == NULL) { 948 icmp6stat.icp6s_tooshort++; 949 return (-1); 950 } 951 #endif 952 /* just ignore a bogus header */ 953 if ((rth0->ip6r0_len % 2) == 0 && 954 (hops = rth0->ip6r0_len/2)) 955 finaldst = (struct in6_addr *)(rth0 + 1) + (hops - 1); 956 } 957 eoff += rthlen; 958 nxt = rth->ip6r_nxt; 959 break; 960 case IPPROTO_FRAGMENT: 961 #ifndef PULLDOWN_TEST 962 IP6_EXTHDR_CHECK(m, 0, eoff + 963 sizeof(struct ip6_frag), -1); 964 fh = (struct ip6_frag *)(mtod(m, caddr_t) + 965 eoff); 966 #else 967 IP6_EXTHDR_GET(fh, struct ip6_frag *, m, 968 eoff, sizeof(*fh)); 969 if (fh == NULL) { 970 icmp6stat.icp6s_tooshort++; 971 return (-1); 972 } 973 #endif 974 /* 975 * Data after a fragment header is meaningless 976 * unless it is the first fragment, but 977 * we'll go to the notify label for path MTU 978 * discovery. 979 */ 980 if (fh->ip6f_offlg & IP6F_OFF_MASK) 981 goto notify; 982 983 eoff += sizeof(struct ip6_frag); 984 nxt = fh->ip6f_nxt; 985 break; 986 default: 987 /* 988 * This case includes ESP and the No Next 989 * Header. In such cases going to the notify 990 * label does not have any meaning 991 * (i.e. ctlfunc will be NULL), but we go 992 * anyway since we might have to update 993 * path MTU information. 994 */ 995 goto notify; 996 } 997 } 998 notify: 999 #ifndef PULLDOWN_TEST 1000 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 1001 #else 1002 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, 1003 sizeof(*icmp6) + sizeof(struct ip6_hdr)); 1004 if (icmp6 == NULL) { 1005 icmp6stat.icp6s_tooshort++; 1006 return (-1); 1007 } 1008 #endif 1009 1010 /* 1011 * retrieve parameters from the inner IPv6 header, and convert 1012 * them into sockaddr structures. 1013 * XXX: there is no guarantee that the source or destination 1014 * addresses of the inner packet are in the same scope as 1015 * the addresses of the icmp packet. But there is no other 1016 * way to determine the zone. 1017 */ 1018 eip6 = (struct ip6_hdr *)(icmp6 + 1); 1019 1020 bzero(&icmp6dst, sizeof(icmp6dst)); 1021 icmp6dst.sin6_len = sizeof(struct sockaddr_in6); 1022 icmp6dst.sin6_family = AF_INET6; 1023 if (finaldst == NULL) 1024 icmp6dst.sin6_addr = eip6->ip6_dst; 1025 else 1026 icmp6dst.sin6_addr = *finaldst; 1027 if (in6_addr2zoneid(m->m_pkthdr.rcvif, &icmp6dst.sin6_addr, 1028 &icmp6dst.sin6_scope_id)) 1029 goto freeit; 1030 if (in6_embedscope(&icmp6dst.sin6_addr, &icmp6dst, 1031 NULL, NULL)) { 1032 /* should be impossible */ 1033 nd6log((LOG_DEBUG, 1034 "icmp6_notify_error: in6_embedscope failed\n")); 1035 goto freeit; 1036 } 1037 1038 /* 1039 * retrieve parameters from the inner IPv6 header, and convert 1040 * them into sockaddr structures. 1041 */ 1042 bzero(&icmp6src, sizeof(icmp6src)); 1043 icmp6src.sin6_len = sizeof(struct sockaddr_in6); 1044 icmp6src.sin6_family = AF_INET6; 1045 icmp6src.sin6_addr = eip6->ip6_src; 1046 if (in6_addr2zoneid(m->m_pkthdr.rcvif, &icmp6src.sin6_addr, 1047 &icmp6src.sin6_scope_id)) { 1048 goto freeit; 1049 } 1050 if (in6_embedscope(&icmp6src.sin6_addr, &icmp6src, 1051 NULL, NULL)) { 1052 /* should be impossible */ 1053 nd6log((LOG_DEBUG, 1054 "icmp6_notify_error: in6_embedscope failed\n")); 1055 goto freeit; 1056 } 1057 icmp6src.sin6_flowinfo = (eip6->ip6_flow & IPV6_FLOWLABEL_MASK); 1058 1059 if (finaldst == NULL) 1060 finaldst = &eip6->ip6_dst; 1061 ip6cp.ip6c_m = m; 1062 ip6cp.ip6c_icmp6 = icmp6; 1063 ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1); 1064 ip6cp.ip6c_off = eoff; 1065 ip6cp.ip6c_finaldst = finaldst; 1066 ip6cp.ip6c_src = &icmp6src; 1067 ip6cp.ip6c_nxt = nxt; 1068 1069 if (icmp6type == ICMP6_PACKET_TOO_BIG) { 1070 notifymtu = ntohl(icmp6->icmp6_mtu); 1071 ip6cp.ip6c_cmdarg = (void *)¬ifymtu; 1072 icmp6_mtudisc_update(&ip6cp, 1); /*XXX*/ 1073 } 1074 1075 ctlfunc = (void (*) __P((int, struct sockaddr *, void *))) 1076 (inet6sw[ip6_protox[nxt]].pr_ctlinput); 1077 if (ctlfunc) { 1078 (void) (*ctlfunc)(code, (struct sockaddr *)&icmp6dst, 1079 &ip6cp); 1080 } 1081 } 1082 *mp = m; 1083 return (0); 1084 1085 freeit: 1086 m_freem(m); 1087 return (-1); 1088 } 1089 1090 void 1091 icmp6_mtudisc_update(ip6cp, validated) 1092 struct ip6ctlparam *ip6cp; 1093 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 /* XXX normally, this won't happen */ 1128 if (IN6_IS_ADDR_LINKLOCAL(dst)) { 1129 inc.inc6_faddr.s6_addr16[1] = 1130 htons(m->m_pkthdr.rcvif->if_index); 1131 } 1132 1133 if (mtu < tcp_maxmtu6(&inc)) { 1134 tcp_hc_updatemtu(&inc, mtu); 1135 icmp6stat.icp6s_pmtuchg++; 1136 } 1137 } 1138 1139 /* 1140 * Process a Node Information Query packet, based on 1141 * draft-ietf-ipngwg-icmp-name-lookups-07. 1142 * 1143 * Spec incompatibilities: 1144 * - IPv6 Subject address handling 1145 * - IPv4 Subject address handling support missing 1146 * - Proxy reply (answer even if it's not for me) 1147 * - joins NI group address at in6_ifattach() time only, does not cope 1148 * with hostname changes by sethostname(3) 1149 */ 1150 #define hostnamelen strlen(hostname) 1151 static struct mbuf * 1152 ni6_input(m, off) 1153 struct mbuf *m; 1154 int off; 1155 { 1156 struct icmp6_nodeinfo *ni6, *nni6; 1157 struct mbuf *n = NULL; 1158 u_int16_t qtype; 1159 int subjlen; 1160 int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); 1161 struct ni_reply_fqdn *fqdn; 1162 int addrs; /* for NI_QTYPE_NODEADDR */ 1163 struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */ 1164 struct sockaddr_in6 sin6_sbj; /* subject address */ 1165 struct ip6_hdr *ip6; 1166 int oldfqdn = 0; /* if 1, return pascal string (03 draft) */ 1167 char *subj = NULL; 1168 struct in6_ifaddr *ia6 = NULL; 1169 1170 ip6 = mtod(m, struct ip6_hdr *); 1171 #ifndef PULLDOWN_TEST 1172 ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off); 1173 #else 1174 IP6_EXTHDR_GET(ni6, struct icmp6_nodeinfo *, m, off, sizeof(*ni6)); 1175 if (ni6 == NULL) { 1176 /* m is already reclaimed */ 1177 return (NULL); 1178 } 1179 #endif 1180 1181 /* 1182 * Validate IPv6 destination address. 1183 * 1184 * The Responder must discard the Query without further processing 1185 * unless it is one of the Responder's unicast or anycast addresses, or 1186 * a link-local scope multicast address which the Responder has joined. 1187 * [icmp-name-lookups-08, Section 4.] 1188 */ 1189 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 1190 if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst)) 1191 goto bad; 1192 /* else it's a link-local multicast, fine */ 1193 } else { /* unicast or anycast */ 1194 if ((ia6 = ip6_getdstifaddr(m)) == NULL) 1195 goto bad; /* XXX impossible */ 1196 1197 if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) && 1198 !(icmp6_nodeinfo & 4)) { 1199 nd6log((LOG_DEBUG, "ni6_input: ignore node info to " 1200 "a temporary address in %s:%d", 1201 __FILE__, __LINE__)); 1202 goto bad; 1203 } 1204 } 1205 1206 /* validate query Subject field. */ 1207 qtype = ntohs(ni6->ni_qtype); 1208 subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo); 1209 switch (qtype) { 1210 case NI_QTYPE_NOOP: 1211 case NI_QTYPE_SUPTYPES: 1212 /* 07 draft */ 1213 if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0) 1214 break; 1215 /* FALLTHROUGH */ 1216 case NI_QTYPE_FQDN: 1217 case NI_QTYPE_NODEADDR: 1218 switch (ni6->ni_code) { 1219 case ICMP6_NI_SUBJ_IPV6: 1220 #if ICMP6_NI_SUBJ_IPV6 != 0 1221 case 0: 1222 #endif 1223 /* 1224 * backward compatibility - try to accept 03 draft 1225 * format, where no Subject is present. 1226 */ 1227 if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 && 1228 subjlen == 0) { 1229 oldfqdn++; 1230 break; 1231 } 1232 #if ICMP6_NI_SUBJ_IPV6 != 0 1233 if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6) 1234 goto bad; 1235 #endif 1236 1237 if (subjlen != sizeof(struct in6_addr)) 1238 goto bad; 1239 1240 /* 1241 * Validate Subject address. 1242 * 1243 * Not sure what exactly "address belongs to the node" 1244 * means in the spec, is it just unicast, or what? 1245 * 1246 * At this moment we consider Subject address as 1247 * "belong to the node" if the Subject address equals 1248 * to the IPv6 destination address; validation for 1249 * IPv6 destination address should have done enough 1250 * check for us. 1251 * 1252 * We do not do proxy at this moment. 1253 */ 1254 /* m_pulldown instead of copy? */ 1255 bzero(&sin6_sbj, sizeof(sin6_sbj)); 1256 sin6_sbj.sin6_family = AF_INET6; 1257 sin6_sbj.sin6_len = sizeof(sin6_sbj); 1258 m_copydata(m, off + sizeof(struct icmp6_nodeinfo), 1259 subjlen, (caddr_t)&sin6_sbj.sin6_addr); 1260 if (in6_addr2zoneid(m->m_pkthdr.rcvif, 1261 &sin6_sbj.sin6_addr, &sin6_sbj.sin6_scope_id)) { 1262 goto bad; 1263 } 1264 if (in6_embedscope(&sin6_sbj.sin6_addr, &sin6_sbj, 1265 NULL, NULL)) 1266 goto bad; /* XXX should not happen */ 1267 1268 subj = (char *)&sin6_sbj; 1269 if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 1270 &sin6_sbj.sin6_addr)) 1271 break; 1272 1273 /* 1274 * XXX if we are to allow other cases, we should really 1275 * be careful about scope here. 1276 * basically, we should disallow queries toward IPv6 1277 * destination X with subject Y, 1278 * if scope(X) > scope(Y). 1279 * if we allow scope(X) > scope(Y), it will result in 1280 * information leakage across scope boundary. 1281 */ 1282 goto bad; 1283 1284 case ICMP6_NI_SUBJ_FQDN: 1285 /* 1286 * Validate Subject name with gethostname(3). 1287 * 1288 * The behavior may need some debate, since: 1289 * - we are not sure if the node has FQDN as 1290 * hostname (returned by gethostname(3)). 1291 * - the code does wildcard match for truncated names. 1292 * however, we are not sure if we want to perform 1293 * wildcard match, if gethostname(3) side has 1294 * truncated hostname. 1295 */ 1296 n = ni6_nametodns(hostname, hostnamelen, 0); 1297 if (!n || n->m_next || n->m_len == 0) 1298 goto bad; 1299 IP6_EXTHDR_GET(subj, char *, m, 1300 off + sizeof(struct icmp6_nodeinfo), subjlen); 1301 if (subj == NULL) 1302 goto bad; 1303 if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *), 1304 n->m_len)) { 1305 goto bad; 1306 } 1307 m_freem(n); 1308 n = NULL; 1309 break; 1310 1311 case ICMP6_NI_SUBJ_IPV4: /* XXX: to be implemented? */ 1312 default: 1313 goto bad; 1314 } 1315 break; 1316 } 1317 1318 /* refuse based on configuration. XXX ICMP6_NI_REFUSED? */ 1319 switch (qtype) { 1320 case NI_QTYPE_FQDN: 1321 if ((icmp6_nodeinfo & 1) == 0) 1322 goto bad; 1323 break; 1324 case NI_QTYPE_NODEADDR: 1325 if ((icmp6_nodeinfo & 2) == 0) 1326 goto bad; 1327 break; 1328 } 1329 1330 /* guess reply length */ 1331 switch (qtype) { 1332 case NI_QTYPE_NOOP: 1333 break; /* no reply data */ 1334 case NI_QTYPE_SUPTYPES: 1335 replylen += sizeof(u_int32_t); 1336 break; 1337 case NI_QTYPE_FQDN: 1338 /* XXX will append an mbuf */ 1339 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); 1340 break; 1341 case NI_QTYPE_NODEADDR: 1342 addrs = ni6_addrs(ni6, m, &ifp, subj); 1343 if ((replylen += addrs * (sizeof(struct in6_addr) + 1344 sizeof(u_int32_t))) > MCLBYTES) 1345 replylen = MCLBYTES; /* XXX: will truncate pkt later */ 1346 break; 1347 default: 1348 /* 1349 * XXX: We must return a reply with the ICMP6 code 1350 * `unknown Qtype' in this case. However we regard the case 1351 * as an FQDN query for backward compatibility. 1352 * Older versions set a random value to this field, 1353 * so it rarely varies in the defined qtypes. 1354 * But the mechanism is not reliable... 1355 * maybe we should obsolete older versions. 1356 */ 1357 qtype = NI_QTYPE_FQDN; 1358 /* XXX will append an mbuf */ 1359 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); 1360 oldfqdn++; 1361 break; 1362 } 1363 1364 /* allocate an mbuf to reply. */ 1365 MGETHDR(n, M_DONTWAIT, m->m_type); 1366 if (n == NULL) { 1367 m_freem(m); 1368 return (NULL); 1369 } 1370 M_MOVE_PKTHDR(n, m); /* just for recvif */ 1371 if (replylen > MHLEN) { 1372 if (replylen > MCLBYTES) { 1373 /* 1374 * XXX: should we try to allocate more? But MCLBYTES 1375 * is probably much larger than IPV6_MMTU... 1376 */ 1377 goto bad; 1378 } 1379 MCLGET(n, M_DONTWAIT); 1380 if ((n->m_flags & M_EXT) == 0) { 1381 goto bad; 1382 } 1383 } 1384 n->m_pkthdr.len = n->m_len = replylen; 1385 1386 /* copy mbuf header and IPv6 + Node Information base headers */ 1387 bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr)); 1388 nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1); 1389 bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo)); 1390 1391 /* qtype dependent procedure */ 1392 switch (qtype) { 1393 case NI_QTYPE_NOOP: 1394 nni6->ni_code = ICMP6_NI_SUCCESS; 1395 nni6->ni_flags = 0; 1396 break; 1397 case NI_QTYPE_SUPTYPES: 1398 { 1399 u_int32_t v; 1400 nni6->ni_code = ICMP6_NI_SUCCESS; 1401 nni6->ni_flags = htons(0x0000); /* raw bitmap */ 1402 /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */ 1403 v = (u_int32_t)htonl(0x0000000f); 1404 bcopy(&v, nni6 + 1, sizeof(u_int32_t)); 1405 break; 1406 } 1407 case NI_QTYPE_FQDN: 1408 nni6->ni_code = ICMP6_NI_SUCCESS; 1409 fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) + 1410 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo)); 1411 nni6->ni_flags = 0; /* XXX: meaningless TTL */ 1412 fqdn->ni_fqdn_ttl = 0; /* ditto. */ 1413 /* 1414 * XXX do we really have FQDN in variable "hostname"? 1415 */ 1416 n->m_next = ni6_nametodns(hostname, hostnamelen, oldfqdn); 1417 if (n->m_next == NULL) 1418 goto bad; 1419 /* XXX we assume that n->m_next is not a chain */ 1420 if (n->m_next->m_next != NULL) 1421 goto bad; 1422 n->m_pkthdr.len += n->m_next->m_len; 1423 break; 1424 case NI_QTYPE_NODEADDR: 1425 { 1426 int lenlim, copied; 1427 1428 nni6->ni_code = ICMP6_NI_SUCCESS; 1429 n->m_pkthdr.len = n->m_len = 1430 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); 1431 lenlim = M_TRAILINGSPACE(n); 1432 copied = ni6_store_addrs(ni6, nni6, ifp, lenlim); 1433 /* XXX: reset mbuf length */ 1434 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + 1435 sizeof(struct icmp6_nodeinfo) + copied; 1436 break; 1437 } 1438 default: 1439 break; /* XXX impossible! */ 1440 } 1441 1442 nni6->ni_type = ICMP6_NI_REPLY; 1443 m_freem(m); 1444 return (n); 1445 1446 bad: 1447 m_freem(m); 1448 if (n) 1449 m_freem(n); 1450 return (NULL); 1451 } 1452 #undef hostnamelen 1453 1454 /* 1455 * make a mbuf with DNS-encoded string. no compression support. 1456 * 1457 * XXX names with less than 2 dots (like "foo" or "foo.section") will be 1458 * treated as truncated name (two \0 at the end). this is a wild guess. 1459 */ 1460 static struct mbuf * 1461 ni6_nametodns(name, namelen, old) 1462 const char *name; 1463 int namelen; 1464 int old; /* return pascal string if non-zero */ 1465 { 1466 struct mbuf *m; 1467 char *cp, *ep; 1468 const char *p, *q; 1469 int i, len, nterm; 1470 1471 if (old) 1472 len = namelen + 1; 1473 else 1474 len = MCLBYTES; 1475 1476 /* because MAXHOSTNAMELEN is usually 256, we use cluster mbuf */ 1477 MGET(m, M_DONTWAIT, MT_DATA); 1478 if (m && len > MLEN) { 1479 MCLGET(m, M_DONTWAIT); 1480 if ((m->m_flags & M_EXT) == 0) 1481 goto fail; 1482 } 1483 if (!m) 1484 goto fail; 1485 m->m_next = NULL; 1486 1487 if (old) { 1488 m->m_len = len; 1489 *mtod(m, char *) = namelen; 1490 bcopy(name, mtod(m, char *) + 1, namelen); 1491 return m; 1492 } else { 1493 m->m_len = 0; 1494 cp = mtod(m, char *); 1495 ep = mtod(m, char *) + M_TRAILINGSPACE(m); 1496 1497 /* if not certain about my name, return empty buffer */ 1498 if (namelen == 0) 1499 return m; 1500 1501 /* 1502 * guess if it looks like shortened hostname, or FQDN. 1503 * shortened hostname needs two trailing "\0". 1504 */ 1505 i = 0; 1506 for (p = name; p < name + namelen; p++) { 1507 if (*p && *p == '.') 1508 i++; 1509 } 1510 if (i < 2) 1511 nterm = 2; 1512 else 1513 nterm = 1; 1514 1515 p = name; 1516 while (cp < ep && p < name + namelen) { 1517 i = 0; 1518 for (q = p; q < name + namelen && *q && *q != '.'; q++) 1519 i++; 1520 /* result does not fit into mbuf */ 1521 if (cp + i + 1 >= ep) 1522 goto fail; 1523 /* 1524 * DNS label length restriction, RFC1035 page 8. 1525 * "i == 0" case is included here to avoid returning 1526 * 0-length label on "foo..bar". 1527 */ 1528 if (i <= 0 || i >= 64) 1529 goto fail; 1530 *cp++ = i; 1531 bcopy(p, cp, i); 1532 cp += i; 1533 p = q; 1534 if (p < name + namelen && *p == '.') 1535 p++; 1536 } 1537 /* termination */ 1538 if (cp + nterm >= ep) 1539 goto fail; 1540 while (nterm-- > 0) 1541 *cp++ = '\0'; 1542 m->m_len = cp - mtod(m, char *); 1543 return m; 1544 } 1545 1546 panic("should not reach here"); 1547 /* NOTREACHED */ 1548 1549 fail: 1550 if (m) 1551 m_freem(m); 1552 return NULL; 1553 } 1554 1555 /* 1556 * check if two DNS-encoded string matches. takes care of truncated 1557 * form (with \0\0 at the end). no compression support. 1558 * XXX upper/lowercase match (see RFC2065) 1559 */ 1560 static int 1561 ni6_dnsmatch(a, alen, b, blen) 1562 const char *a; 1563 int alen; 1564 const char *b; 1565 int blen; 1566 { 1567 const char *a0, *b0; 1568 int l; 1569 1570 /* simplest case - need validation? */ 1571 if (alen == blen && bcmp(a, b, alen) == 0) 1572 return 1; 1573 1574 a0 = a; 1575 b0 = b; 1576 1577 /* termination is mandatory */ 1578 if (alen < 2 || blen < 2) 1579 return 0; 1580 if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0') 1581 return 0; 1582 alen--; 1583 blen--; 1584 1585 while (a - a0 < alen && b - b0 < blen) { 1586 if (a - a0 + 1 > alen || b - b0 + 1 > blen) 1587 return 0; 1588 1589 if ((signed char)a[0] < 0 || (signed char)b[0] < 0) 1590 return 0; 1591 /* we don't support compression yet */ 1592 if (a[0] >= 64 || b[0] >= 64) 1593 return 0; 1594 1595 /* truncated case */ 1596 if (a[0] == 0 && a - a0 == alen - 1) 1597 return 1; 1598 if (b[0] == 0 && b - b0 == blen - 1) 1599 return 1; 1600 if (a[0] == 0 || b[0] == 0) 1601 return 0; 1602 1603 if (a[0] != b[0]) 1604 return 0; 1605 l = a[0]; 1606 if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen) 1607 return 0; 1608 if (bcmp(a + 1, b + 1, l) != 0) 1609 return 0; 1610 1611 a += 1 + l; 1612 b += 1 + l; 1613 } 1614 1615 if (a - a0 == alen && b - b0 == blen) 1616 return 1; 1617 else 1618 return 0; 1619 } 1620 1621 /* 1622 * calculate the number of addresses to be returned in the node info reply. 1623 */ 1624 static int 1625 ni6_addrs(ni6, m, ifpp, subj) 1626 struct icmp6_nodeinfo *ni6; 1627 struct mbuf *m; 1628 struct ifnet **ifpp; 1629 char *subj; 1630 { 1631 struct ifnet *ifp; 1632 struct in6_ifaddr *ifa6; 1633 struct ifaddr *ifa; 1634 struct sockaddr_in6 *subj_ip6 = NULL; /* XXX pedant */ 1635 int addrs = 0, addrsofif, iffound = 0; 1636 int niflags = ni6->ni_flags; 1637 1638 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) { 1639 switch (ni6->ni_code) { 1640 case ICMP6_NI_SUBJ_IPV6: 1641 if (subj == NULL) /* must be impossible... */ 1642 return (0); 1643 subj_ip6 = (struct sockaddr_in6 *)subj; 1644 break; 1645 default: 1646 /* 1647 * XXX: we only support IPv6 subject address for 1648 * this Qtype. 1649 */ 1650 return (0); 1651 } 1652 } 1653 1654 IFNET_RLOCK(); 1655 for (ifp = TAILQ_FIRST(&ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list)) { 1656 addrsofif = 0; 1657 TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) { 1658 if (ifa->ifa_addr->sa_family != AF_INET6) 1659 continue; 1660 ifa6 = (struct in6_ifaddr *)ifa; 1661 1662 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 && 1663 IN6_ARE_ADDR_EQUAL(&subj_ip6->sin6_addr, 1664 &ifa6->ia_addr.sin6_addr)) 1665 iffound = 1; 1666 1667 /* 1668 * IPv4-mapped addresses can only be returned by a 1669 * Node Information proxy, since they represent 1670 * addresses of IPv4-only nodes, which perforce do 1671 * not implement this protocol. 1672 * [icmp-name-lookups-07, Section 5.4] 1673 * So we don't support NI_NODEADDR_FLAG_COMPAT in 1674 * this function at this moment. 1675 */ 1676 1677 /* What do we have to do about ::1? */ 1678 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { 1679 case IPV6_ADDR_SCOPE_LINKLOCAL: 1680 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) 1681 continue; 1682 break; 1683 case IPV6_ADDR_SCOPE_SITELOCAL: 1684 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) 1685 continue; 1686 break; 1687 case IPV6_ADDR_SCOPE_GLOBAL: 1688 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) 1689 continue; 1690 break; 1691 default: 1692 continue; 1693 } 1694 1695 /* 1696 * check if anycast is okay. 1697 * XXX: just experimental. not in the spec. 1698 */ 1699 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && 1700 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) 1701 continue; /* we need only unicast addresses */ 1702 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && 1703 (icmp6_nodeinfo & 4) == 0) { 1704 continue; 1705 } 1706 addrsofif++; /* count the address */ 1707 } 1708 if (iffound) { 1709 *ifpp = ifp; 1710 IFNET_RUNLOCK(); 1711 return (addrsofif); 1712 } 1713 1714 addrs += addrsofif; 1715 } 1716 IFNET_RUNLOCK(); 1717 1718 return (addrs); 1719 } 1720 1721 static int 1722 ni6_store_addrs(ni6, nni6, ifp0, resid) 1723 struct icmp6_nodeinfo *ni6, *nni6; 1724 struct ifnet *ifp0; 1725 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 & 4) == 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 */ 1863 static int 1864 icmp6_rip6_input(mp, off) 1865 struct mbuf **mp; 1866 int off; 1867 { 1868 struct mbuf *m = *mp; 1869 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1870 struct in6pcb *in6p; 1871 struct in6pcb *last = NULL; 1872 struct sockaddr_in6 fromsa; 1873 struct icmp6_hdr *icmp6; 1874 struct mbuf *opts = NULL; 1875 1876 #ifndef PULLDOWN_TEST 1877 /* this is assumed to be safe. */ 1878 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off); 1879 #else 1880 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6)); 1881 if (icmp6 == NULL) { 1882 /* m is already reclaimed */ 1883 return (IPPROTO_DONE); 1884 } 1885 #endif 1886 1887 bzero(&fromsa, sizeof(fromsa)); 1888 fromsa.sin6_len = sizeof(struct sockaddr_in6); 1889 fromsa.sin6_family = AF_INET6; 1890 /* KAME hack: recover scopeid */ 1891 (void)in6_recoverscope(&fromsa, &ip6->ip6_src, m->m_pkthdr.rcvif); 1892 1893 INP_INFO_RLOCK(&ripcbinfo); 1894 LIST_FOREACH(in6p, &ripcb, inp_list) { 1895 INP_LOCK(in6p); 1896 if ((in6p->inp_vflag & INP_IPV6) == 0) { 1897 docontinue: 1898 INP_UNLOCK(in6p); 1899 continue; 1900 } 1901 if (in6p->in6p_ip6_nxt != IPPROTO_ICMPV6) 1902 goto docontinue; 1903 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) && 1904 !IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &ip6->ip6_dst)) 1905 goto docontinue; 1906 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr) && 1907 !IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src)) 1908 goto docontinue; 1909 if (in6p->in6p_icmp6filt 1910 && ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type, 1911 in6p->in6p_icmp6filt)) 1912 goto docontinue; 1913 if (last) { 1914 struct mbuf *n = NULL; 1915 1916 /* 1917 * Recent network drivers tend to allocate a single 1918 * mbuf cluster, rather than to make a couple of 1919 * mbufs without clusters. Also, since the IPv6 code 1920 * path tries to avoid m_pullup(), it is highly 1921 * probable that we still have an mbuf cluster here 1922 * even though the necessary length can be stored in an 1923 * mbuf's internal buffer. 1924 * Meanwhile, the default size of the receive socket 1925 * buffer for raw sockets is not so large. This means 1926 * the possibility of packet loss is relatively higher 1927 * than before. To avoid this scenario, we copy the 1928 * received data to a separate mbuf that does not use 1929 * a cluster, if possible. 1930 * XXX: it is better to copy the data after stripping 1931 * intermediate headers. 1932 */ 1933 if ((m->m_flags & M_EXT) && m->m_next == NULL && 1934 m->m_len <= MHLEN) { 1935 MGET(n, M_DONTWAIT, m->m_type); 1936 if (n != NULL) { 1937 if (m_dup_pkthdr(n, m, M_NOWAIT)) { 1938 bcopy(m->m_data, n->m_data, 1939 m->m_len); 1940 n->m_len = m->m_len; 1941 } else { 1942 m_free(n); 1943 n = NULL; 1944 } 1945 } 1946 } 1947 if (n != NULL || 1948 (n = m_copy(m, 0, (int)M_COPYALL)) != NULL) { 1949 if (last->in6p_flags & IN6P_CONTROLOPTS) 1950 ip6_savecontrol(last, n, &opts); 1951 /* strip intermediate headers */ 1952 m_adj(n, off); 1953 if (sbappendaddr(&last->in6p_socket->so_rcv, 1954 (struct sockaddr *)&fromsa, n, opts) 1955 == 0) { 1956 /* should notify about lost packet */ 1957 m_freem(n); 1958 if (opts) { 1959 m_freem(opts); 1960 } 1961 } else 1962 sorwakeup(last->in6p_socket); 1963 opts = NULL; 1964 } 1965 INP_UNLOCK(last); 1966 } 1967 last = in6p; 1968 } 1969 if (last) { 1970 if (last->in6p_flags & IN6P_CONTROLOPTS) 1971 ip6_savecontrol(last, m, &opts); 1972 /* strip intermediate headers */ 1973 m_adj(m, off); 1974 1975 /* avoid using mbuf clusters if possible (see above) */ 1976 if ((m->m_flags & M_EXT) && m->m_next == NULL && 1977 m->m_len <= MHLEN) { 1978 struct mbuf *n; 1979 1980 MGET(n, M_DONTWAIT, m->m_type); 1981 if (n != NULL) { 1982 if (m_dup_pkthdr(n, m, M_NOWAIT)) { 1983 bcopy(m->m_data, n->m_data, m->m_len); 1984 n->m_len = m->m_len; 1985 1986 m_freem(m); 1987 m = n; 1988 } else { 1989 m_freem(n); 1990 n = NULL; 1991 } 1992 } 1993 } 1994 if (sbappendaddr(&last->in6p_socket->so_rcv, 1995 (struct sockaddr *)&fromsa, m, opts) == 0) { 1996 m_freem(m); 1997 if (opts) 1998 m_freem(opts); 1999 } else 2000 sorwakeup(last->in6p_socket); 2001 INP_UNLOCK(last); 2002 } else { 2003 m_freem(m); 2004 ip6stat.ip6s_delivered--; 2005 } 2006 INP_INFO_RUNLOCK(&ripcbinfo); 2007 return IPPROTO_DONE; 2008 } 2009 2010 /* 2011 * Reflect the ip6 packet back to the source. 2012 * OFF points to the icmp6 header, counted from the top of the mbuf. 2013 */ 2014 void 2015 icmp6_reflect(m, off) 2016 struct mbuf *m; 2017 size_t off; 2018 { 2019 struct ip6_hdr *ip6; 2020 struct icmp6_hdr *icmp6; 2021 struct in6_ifaddr *ia; 2022 struct in6_addr t, *src = 0; 2023 int plen; 2024 int type, code; 2025 struct ifnet *outif = NULL; 2026 struct sockaddr_in6 sa6_src, sa6_dst; 2027 #ifdef COMPAT_RFC1885 2028 int mtu = IPV6_MMTU; 2029 struct sockaddr_in6 *sin6 = &icmp6_reflect_rt.ro_dst; 2030 #endif 2031 2032 /* too short to reflect */ 2033 if (off < sizeof(struct ip6_hdr)) { 2034 nd6log((LOG_DEBUG, 2035 "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n", 2036 (u_long)off, (u_long)sizeof(struct ip6_hdr), 2037 __FILE__, __LINE__)); 2038 goto bad; 2039 } 2040 2041 /* 2042 * If there are extra headers between IPv6 and ICMPv6, strip 2043 * off that header first. 2044 */ 2045 #ifdef DIAGNOSTIC 2046 if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN) 2047 panic("assumption failed in icmp6_reflect"); 2048 #endif 2049 if (off > sizeof(struct ip6_hdr)) { 2050 size_t l; 2051 struct ip6_hdr nip6; 2052 2053 l = off - sizeof(struct ip6_hdr); 2054 m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6); 2055 m_adj(m, l); 2056 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 2057 if (m->m_len < l) { 2058 if ((m = m_pullup(m, l)) == NULL) 2059 return; 2060 } 2061 bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6)); 2062 } else /* off == sizeof(struct ip6_hdr) */ { 2063 size_t l; 2064 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 2065 if (m->m_len < l) { 2066 if ((m = m_pullup(m, l)) == NULL) 2067 return; 2068 } 2069 } 2070 plen = m->m_pkthdr.len - sizeof(struct ip6_hdr); 2071 ip6 = mtod(m, struct ip6_hdr *); 2072 ip6->ip6_nxt = IPPROTO_ICMPV6; 2073 icmp6 = (struct icmp6_hdr *)(ip6 + 1); 2074 type = icmp6->icmp6_type; /* keep type for statistics */ 2075 code = icmp6->icmp6_code; /* ditto. */ 2076 2077 t = ip6->ip6_dst; 2078 /* 2079 * ip6_input() drops a packet if its src is multicast. 2080 * So, the src is never multicast. 2081 */ 2082 ip6->ip6_dst = ip6->ip6_src; 2083 2084 /* 2085 * XXX: make sure to embed scope zone information, using 2086 * already embedded IDs or the received interface (if any). 2087 * Note that rcvif may be NULL. 2088 * TODO: scoped routing case (XXX). 2089 */ 2090 bzero(&sa6_src, sizeof(sa6_src)); 2091 sa6_src.sin6_family = AF_INET6; 2092 sa6_src.sin6_len = sizeof(sa6_src); 2093 sa6_src.sin6_addr = ip6->ip6_dst; 2094 in6_recoverscope(&sa6_src, &ip6->ip6_dst, m->m_pkthdr.rcvif); 2095 if (in6_embedscope(&ip6->ip6_dst, &sa6_src, NULL, NULL)) 2096 goto bad; 2097 2098 bzero(&sa6_dst, sizeof(sa6_dst)); 2099 sa6_dst.sin6_family = AF_INET6; 2100 sa6_dst.sin6_len = sizeof(sa6_dst); 2101 sa6_dst.sin6_addr = t; 2102 in6_recoverscope(&sa6_dst, &t, m->m_pkthdr.rcvif); 2103 if (in6_embedscope(&t, &sa6_dst, NULL, NULL)) 2104 goto bad; 2105 2106 #ifdef COMPAT_RFC1885 2107 /* 2108 * xxx guess MTU 2109 * RFC 1885 requires that echo reply should be truncated if it 2110 * does not fit in with (return) path MTU, but the description was 2111 * removed in the new spec. 2112 */ 2113 if (icmp6_reflect_rt.ro_rt == 0 || 2114 ! (IN6_ARE_ADDR_EQUAL(&sin6->sin6_addr, &ip6->ip6_dst))) { 2115 if (icmp6_reflect_rt.ro_rt) { 2116 RTFREE(icmp6_reflect_rt.ro_rt); 2117 icmp6_reflect_rt.ro_rt = 0; 2118 } 2119 bzero(sin6, sizeof(*sin6)); 2120 sin6->sin6_family = PF_INET6; 2121 sin6->sin6_len = sizeof(struct sockaddr_in6); 2122 sin6->sin6_addr = ip6->ip6_dst; 2123 2124 rtalloc((struct route *)&icmp6_reflect_rt.ro_rt); 2125 } 2126 2127 if (icmp6_reflect_rt.ro_rt == 0) 2128 goto bad; 2129 2130 if ((icmp6_reflect_rt.ro_rt->rt_flags & RTF_HOST) 2131 && mtu < icmp6_reflect_rt.ro_rt->rt_ifp->if_mtu) 2132 mtu = icmp6_reflect_rt.ro_rt->rt_rmx.rmx_mtu; 2133 2134 if (mtu < m->m_pkthdr.len) { 2135 plen -= (m->m_pkthdr.len - mtu); 2136 m_adj(m, mtu - m->m_pkthdr.len); 2137 } 2138 #endif 2139 /* 2140 * If the incoming packet was addressed directly to us (i.e. unicast), 2141 * use dst as the src for the reply. 2142 * The IN6_IFF_NOTREADY case should be VERY rare, but is possible 2143 * (for example) when we encounter an error while forwarding procedure 2144 * destined to a duplicated address of ours. 2145 */ 2146 for (ia = in6_ifaddr; ia; ia = ia->ia_next) 2147 if (IN6_ARE_ADDR_EQUAL(&t, &ia->ia_addr.sin6_addr) && 2148 (ia->ia6_flags & (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY)) == 0) { 2149 src = &t; 2150 break; 2151 } 2152 if (ia == NULL && IN6_IS_ADDR_LINKLOCAL(&t) && (m->m_flags & M_LOOP)) { 2153 /* 2154 * This is the case if the dst is our link-local address 2155 * and the sender is also ourselves. 2156 */ 2157 src = &t; 2158 } 2159 2160 if (src == 0) { 2161 int e; 2162 struct route_in6 ro; 2163 2164 /* 2165 * This case matches to multicasts, our anycast, or unicasts 2166 * that we do not own. Select a source address based on the 2167 * source address of the erroneous packet. 2168 */ 2169 bzero(&ro, sizeof(ro)); 2170 src = in6_selectsrc(&sa6_src, NULL, NULL, &ro, NULL, &e); 2171 if (ro.ro_rt) 2172 RTFREE(ro.ro_rt); /* XXX: we could use this */ 2173 if (src == NULL) { 2174 nd6log((LOG_DEBUG, 2175 "icmp6_reflect: source can't be determined: " 2176 "dst=%s, error=%d\n", 2177 ip6_sprintf(&sa6_src.sin6_addr), e)); 2178 goto bad; 2179 } 2180 } 2181 2182 ip6->ip6_src = *src; 2183 2184 ip6->ip6_flow = 0; 2185 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2186 ip6->ip6_vfc |= IPV6_VERSION; 2187 ip6->ip6_nxt = IPPROTO_ICMPV6; 2188 if (outif) 2189 ip6->ip6_hlim = ND_IFINFO(outif)->chlim; 2190 else if (m->m_pkthdr.rcvif) { 2191 /* XXX: This may not be the outgoing interface */ 2192 ip6->ip6_hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim; 2193 } else 2194 ip6->ip6_hlim = ip6_defhlim; 2195 2196 icmp6->icmp6_cksum = 0; 2197 icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2198 sizeof(struct ip6_hdr), plen); 2199 2200 /* 2201 * XXX option handling 2202 */ 2203 2204 m->m_flags &= ~(M_BCAST|M_MCAST); 2205 2206 #ifdef COMPAT_RFC1885 2207 ip6_output(m, NULL, &icmp6_reflect_rt, 0, NULL, &outif, NULL); 2208 #else 2209 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2210 #endif 2211 if (outif) 2212 icmp6_ifoutstat_inc(outif, type, code); 2213 2214 return; 2215 2216 bad: 2217 m_freem(m); 2218 return; 2219 } 2220 2221 void 2222 icmp6_fasttimo() 2223 { 2224 2225 mld6_fasttimeo(); 2226 } 2227 2228 static const char * 2229 icmp6_redirect_diag(src6, dst6, tgt6) 2230 struct in6_addr *src6; 2231 struct in6_addr *dst6; 2232 struct in6_addr *tgt6; 2233 { 2234 static char buf[1024]; 2235 snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)", 2236 ip6_sprintf(src6), ip6_sprintf(dst6), ip6_sprintf(tgt6)); 2237 return buf; 2238 } 2239 2240 void 2241 icmp6_redirect_input(m, off) 2242 struct mbuf *m; 2243 int off; 2244 { 2245 struct ifnet *ifp = m->m_pkthdr.rcvif; 2246 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 2247 struct nd_redirect *nd_rd; 2248 int icmp6len = ntohs(ip6->ip6_plen); 2249 char *lladdr = NULL; 2250 int lladdrlen = 0; 2251 u_char *redirhdr = NULL; 2252 int redirhdrlen = 0; 2253 struct rtentry *rt = NULL; 2254 int is_router; 2255 int is_onlink; 2256 struct in6_addr src6 = ip6->ip6_src; 2257 struct in6_addr redtgt6; 2258 struct in6_addr reddst6; 2259 union nd_opts ndopts; 2260 2261 if (!m || !ifp) 2262 return; 2263 2264 /* XXX if we are router, we don't update route by icmp6 redirect */ 2265 if (ip6_forwarding) 2266 goto freeit; 2267 if (!icmp6_rediraccept) 2268 goto freeit; 2269 2270 #ifndef PULLDOWN_TEST 2271 IP6_EXTHDR_CHECK(m, off, icmp6len,); 2272 nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off); 2273 #else 2274 IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len); 2275 if (nd_rd == NULL) { 2276 icmp6stat.icp6s_tooshort++; 2277 return; 2278 } 2279 #endif 2280 redtgt6 = nd_rd->nd_rd_target; 2281 reddst6 = nd_rd->nd_rd_dst; 2282 2283 if (IN6_IS_ADDR_LINKLOCAL(&redtgt6)) 2284 redtgt6.s6_addr16[1] = htons(ifp->if_index); 2285 if (IN6_IS_ADDR_LINKLOCAL(&reddst6)) 2286 reddst6.s6_addr16[1] = htons(ifp->if_index); 2287 2288 /* validation */ 2289 if (!IN6_IS_ADDR_LINKLOCAL(&src6)) { 2290 nd6log((LOG_ERR, 2291 "ICMP6 redirect sent from %s rejected; " 2292 "must be from linklocal\n", 2293 ip6_sprintf(&src6))); 2294 goto bad; 2295 } 2296 if (ip6->ip6_hlim != 255) { 2297 nd6log((LOG_ERR, 2298 "ICMP6 redirect sent from %s rejected; " 2299 "hlim=%d (must be 255)\n", 2300 ip6_sprintf(&src6), ip6->ip6_hlim)); 2301 goto bad; 2302 } 2303 { 2304 /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */ 2305 struct sockaddr_in6 sin6; 2306 struct in6_addr *gw6; 2307 2308 bzero(&sin6, sizeof(sin6)); 2309 sin6.sin6_family = AF_INET6; 2310 sin6.sin6_len = sizeof(struct sockaddr_in6); 2311 bcopy(&reddst6, &sin6.sin6_addr, sizeof(reddst6)); 2312 rt = rtalloc1((struct sockaddr *)&sin6, 0, 0UL); 2313 if (rt) { 2314 if (rt->rt_gateway == NULL || 2315 rt->rt_gateway->sa_family != AF_INET6) { 2316 nd6log((LOG_ERR, 2317 "ICMP6 redirect rejected; no route " 2318 "with inet6 gateway found for redirect dst: %s\n", 2319 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2320 RTFREE_LOCKED(rt); 2321 goto bad; 2322 } 2323 2324 gw6 = &(((struct sockaddr_in6 *)rt->rt_gateway)->sin6_addr); 2325 if (bcmp(&src6, gw6, sizeof(struct in6_addr)) != 0) { 2326 nd6log((LOG_ERR, 2327 "ICMP6 redirect rejected; " 2328 "not equal to gw-for-src=%s (must be same): " 2329 "%s\n", 2330 ip6_sprintf(gw6), 2331 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2332 RTFREE_LOCKED(rt); 2333 goto bad; 2334 } 2335 } else { 2336 nd6log((LOG_ERR, 2337 "ICMP6 redirect rejected; " 2338 "no route found for redirect dst: %s\n", 2339 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2340 goto bad; 2341 } 2342 RTFREE_LOCKED(rt); 2343 rt = NULL; 2344 } 2345 if (IN6_IS_ADDR_MULTICAST(&reddst6)) { 2346 nd6log((LOG_ERR, 2347 "ICMP6 redirect rejected; " 2348 "redirect dst must be unicast: %s\n", 2349 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2350 goto bad; 2351 } 2352 2353 is_router = is_onlink = 0; 2354 if (IN6_IS_ADDR_LINKLOCAL(&redtgt6)) 2355 is_router = 1; /* router case */ 2356 if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0) 2357 is_onlink = 1; /* on-link destination case */ 2358 if (!is_router && !is_onlink) { 2359 nd6log((LOG_ERR, 2360 "ICMP6 redirect rejected; " 2361 "neither router case nor onlink case: %s\n", 2362 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2363 goto bad; 2364 } 2365 /* validation passed */ 2366 2367 icmp6len -= sizeof(*nd_rd); 2368 nd6_option_init(nd_rd + 1, icmp6len, &ndopts); 2369 if (nd6_options(&ndopts) < 0) { 2370 nd6log((LOG_INFO, "icmp6_redirect_input: " 2371 "invalid ND option, rejected: %s\n", 2372 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2373 /* nd6_options have incremented stats */ 2374 goto freeit; 2375 } 2376 2377 if (ndopts.nd_opts_tgt_lladdr) { 2378 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 2379 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 2380 } 2381 2382 if (ndopts.nd_opts_rh) { 2383 redirhdrlen = ndopts.nd_opts_rh->nd_opt_rh_len; 2384 redirhdr = (u_char *)(ndopts.nd_opts_rh + 1); /* xxx */ 2385 } 2386 2387 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 2388 nd6log((LOG_INFO, 2389 "icmp6_redirect_input: lladdrlen mismatch for %s " 2390 "(if %d, icmp6 packet %d): %s\n", 2391 ip6_sprintf(&redtgt6), ifp->if_addrlen, lladdrlen - 2, 2392 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2393 goto bad; 2394 } 2395 2396 /* RFC 2461 8.3 */ 2397 nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT, 2398 is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER); 2399 2400 if (!is_onlink) { /* better router case. perform rtredirect. */ 2401 /* perform rtredirect */ 2402 struct sockaddr_in6 sdst; 2403 struct sockaddr_in6 sgw; 2404 struct sockaddr_in6 ssrc; 2405 2406 bzero(&sdst, sizeof(sdst)); 2407 bzero(&sgw, sizeof(sgw)); 2408 bzero(&ssrc, sizeof(ssrc)); 2409 sdst.sin6_family = sgw.sin6_family = ssrc.sin6_family = AF_INET6; 2410 sdst.sin6_len = sgw.sin6_len = ssrc.sin6_len = 2411 sizeof(struct sockaddr_in6); 2412 bcopy(&redtgt6, &sgw.sin6_addr, sizeof(struct in6_addr)); 2413 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr)); 2414 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr)); 2415 rtredirect((struct sockaddr *)&sdst, (struct sockaddr *)&sgw, 2416 (struct sockaddr *)NULL, RTF_GATEWAY | RTF_HOST, 2417 (struct sockaddr *)&ssrc); 2418 } 2419 /* finally update cached route in each socket via pfctlinput */ 2420 { 2421 struct sockaddr_in6 sdst; 2422 2423 bzero(&sdst, sizeof(sdst)); 2424 sdst.sin6_family = AF_INET6; 2425 sdst.sin6_len = sizeof(struct sockaddr_in6); 2426 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr)); 2427 pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst); 2428 #if defined(IPSEC) || defined(FAST_IPSEC) 2429 key_sa_routechange((struct sockaddr *)&sdst); 2430 #endif 2431 } 2432 2433 freeit: 2434 m_freem(m); 2435 return; 2436 2437 bad: 2438 icmp6stat.icp6s_badredirect++; 2439 m_freem(m); 2440 } 2441 2442 void 2443 icmp6_redirect_output(m0, rt) 2444 struct mbuf *m0; 2445 struct rtentry *rt; 2446 { 2447 struct ifnet *ifp; /* my outgoing interface */ 2448 struct in6_addr *ifp_ll6; 2449 struct in6_addr *router_ll6; 2450 struct ip6_hdr *sip6; /* m0 as struct ip6_hdr */ 2451 struct mbuf *m = NULL; /* newly allocated one */ 2452 struct ip6_hdr *ip6; /* m as struct ip6_hdr */ 2453 struct nd_redirect *nd_rd; 2454 size_t maxlen; 2455 u_char *p; 2456 struct ifnet *outif = NULL; 2457 struct sockaddr_in6 src_sa; 2458 2459 icmp6_errcount(&icmp6stat.icp6s_outerrhist, ND_REDIRECT, 0); 2460 2461 /* if we are not router, we don't send icmp6 redirect */ 2462 if (!ip6_forwarding || ip6_accept_rtadv) 2463 goto fail; 2464 2465 /* sanity check */ 2466 if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp)) 2467 goto fail; 2468 2469 /* 2470 * Address check: 2471 * the source address must identify a neighbor, and 2472 * the destination address must not be a multicast address 2473 * [RFC 2461, sec 8.2] 2474 */ 2475 sip6 = mtod(m0, struct ip6_hdr *); 2476 bzero(&src_sa, sizeof(src_sa)); 2477 src_sa.sin6_family = AF_INET6; 2478 src_sa.sin6_len = sizeof(src_sa); 2479 src_sa.sin6_addr = sip6->ip6_src; 2480 /* we don't currently use sin6_scope_id, but eventually use it */ 2481 if (in6_addr2zoneid(ifp, &sip6->ip6_src, &src_sa.sin6_scope_id)) 2482 goto fail; 2483 if (nd6_is_addr_neighbor(&src_sa, ifp) == 0) 2484 goto fail; 2485 if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst)) 2486 goto fail; /* what should we do here? */ 2487 2488 /* rate limit */ 2489 if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0)) 2490 goto fail; 2491 2492 /* 2493 * Since we are going to append up to 1280 bytes (= IPV6_MMTU), 2494 * we almost always ask for an mbuf cluster for simplicity. 2495 * (MHLEN < IPV6_MMTU is almost always true) 2496 */ 2497 #if IPV6_MMTU >= MCLBYTES 2498 # error assumption failed about IPV6_MMTU and MCLBYTES 2499 #endif 2500 MGETHDR(m, M_DONTWAIT, MT_HEADER); 2501 if (m && IPV6_MMTU >= MHLEN) 2502 MCLGET(m, M_DONTWAIT); 2503 if (!m) 2504 goto fail; 2505 m->m_pkthdr.rcvif = NULL; 2506 m->m_len = 0; 2507 maxlen = M_TRAILINGSPACE(m); 2508 maxlen = min(IPV6_MMTU, maxlen); 2509 /* just for safety */ 2510 if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) + 2511 ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) { 2512 goto fail; 2513 } 2514 2515 { 2516 /* get ip6 linklocal address for ifp(my outgoing interface). */ 2517 struct in6_ifaddr *ia; 2518 if ((ia = in6ifa_ifpforlinklocal(ifp, 2519 IN6_IFF_NOTREADY| 2520 IN6_IFF_ANYCAST)) == NULL) 2521 goto fail; 2522 ifp_ll6 = &ia->ia_addr.sin6_addr; 2523 } 2524 2525 /* get ip6 linklocal address for the router. */ 2526 if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) { 2527 struct sockaddr_in6 *sin6; 2528 sin6 = (struct sockaddr_in6 *)rt->rt_gateway; 2529 router_ll6 = &sin6->sin6_addr; 2530 if (!IN6_IS_ADDR_LINKLOCAL(router_ll6)) 2531 router_ll6 = (struct in6_addr *)NULL; 2532 } else 2533 router_ll6 = (struct in6_addr *)NULL; 2534 2535 /* ip6 */ 2536 ip6 = mtod(m, struct ip6_hdr *); 2537 ip6->ip6_flow = 0; 2538 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2539 ip6->ip6_vfc |= IPV6_VERSION; 2540 /* ip6->ip6_plen will be set later */ 2541 ip6->ip6_nxt = IPPROTO_ICMPV6; 2542 ip6->ip6_hlim = 255; 2543 /* ip6->ip6_src must be linklocal addr for my outgoing if. */ 2544 bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr)); 2545 bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr)); 2546 2547 /* ND Redirect */ 2548 nd_rd = (struct nd_redirect *)(ip6 + 1); 2549 nd_rd->nd_rd_type = ND_REDIRECT; 2550 nd_rd->nd_rd_code = 0; 2551 nd_rd->nd_rd_reserved = 0; 2552 if (rt->rt_flags & RTF_GATEWAY) { 2553 /* 2554 * nd_rd->nd_rd_target must be a link-local address in 2555 * better router cases. 2556 */ 2557 if (!router_ll6) 2558 goto fail; 2559 bcopy(router_ll6, &nd_rd->nd_rd_target, 2560 sizeof(nd_rd->nd_rd_target)); 2561 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2562 sizeof(nd_rd->nd_rd_dst)); 2563 } else { 2564 /* make sure redtgt == reddst */ 2565 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target, 2566 sizeof(nd_rd->nd_rd_target)); 2567 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2568 sizeof(nd_rd->nd_rd_dst)); 2569 } 2570 2571 p = (u_char *)(nd_rd + 1); 2572 2573 if (!router_ll6) 2574 goto nolladdropt; 2575 2576 { 2577 /* target lladdr option */ 2578 struct rtentry *rt_router = NULL; 2579 int len; 2580 struct sockaddr_dl *sdl; 2581 struct nd_opt_hdr *nd_opt; 2582 char *lladdr; 2583 2584 rt_router = nd6_lookup(router_ll6, 0, ifp); 2585 if (!rt_router) 2586 goto nolladdropt; 2587 len = sizeof(*nd_opt) + ifp->if_addrlen; 2588 len = (len + 7) & ~7; /* round by 8 */ 2589 /* safety check */ 2590 if (len + (p - (u_char *)ip6) > maxlen) 2591 goto nolladdropt; 2592 if (!(rt_router->rt_flags & RTF_GATEWAY) && 2593 (rt_router->rt_flags & RTF_LLINFO) && 2594 (rt_router->rt_gateway->sa_family == AF_LINK) && 2595 (sdl = (struct sockaddr_dl *)rt_router->rt_gateway) && 2596 sdl->sdl_alen) { 2597 nd_opt = (struct nd_opt_hdr *)p; 2598 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 2599 nd_opt->nd_opt_len = len >> 3; 2600 lladdr = (char *)(nd_opt + 1); 2601 bcopy(LLADDR(sdl), lladdr, ifp->if_addrlen); 2602 p += len; 2603 } 2604 } 2605 nolladdropt:; 2606 2607 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2608 2609 /* just to be safe */ 2610 #ifdef M_DECRYPTED /*not openbsd*/ 2611 if (m0->m_flags & M_DECRYPTED) 2612 goto noredhdropt; 2613 #endif 2614 if (p - (u_char *)ip6 > maxlen) 2615 goto noredhdropt; 2616 2617 { 2618 /* redirected header option */ 2619 int len; 2620 struct nd_opt_rd_hdr *nd_opt_rh; 2621 2622 /* 2623 * compute the maximum size for icmp6 redirect header option. 2624 * XXX room for auth header? 2625 */ 2626 len = maxlen - (p - (u_char *)ip6); 2627 len &= ~7; 2628 2629 /* This is just for simplicity. */ 2630 if (m0->m_pkthdr.len != m0->m_len) { 2631 if (m0->m_next) { 2632 m_freem(m0->m_next); 2633 m0->m_next = NULL; 2634 } 2635 m0->m_pkthdr.len = m0->m_len; 2636 } 2637 2638 /* 2639 * Redirected header option spec (RFC2461 4.6.3) talks nothing 2640 * about padding/truncate rule for the original IP packet. 2641 * From the discussion on IPv6imp in Feb 1999, 2642 * the consensus was: 2643 * - "attach as much as possible" is the goal 2644 * - pad if not aligned (original size can be guessed by 2645 * original ip6 header) 2646 * Following code adds the padding if it is simple enough, 2647 * and truncates if not. 2648 */ 2649 if (m0->m_next || m0->m_pkthdr.len != m0->m_len) 2650 panic("assumption failed in %s:%d", __FILE__, 2651 __LINE__); 2652 2653 if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) { 2654 /* not enough room, truncate */ 2655 m0->m_pkthdr.len = m0->m_len = len - 2656 sizeof(*nd_opt_rh); 2657 } else { 2658 /* enough room, pad or truncate */ 2659 size_t extra; 2660 2661 extra = m0->m_pkthdr.len % 8; 2662 if (extra) { 2663 /* pad if easy enough, truncate if not */ 2664 if (8 - extra <= M_TRAILINGSPACE(m0)) { 2665 /* pad */ 2666 m0->m_len += (8 - extra); 2667 m0->m_pkthdr.len += (8 - extra); 2668 } else { 2669 /* truncate */ 2670 m0->m_pkthdr.len -= extra; 2671 m0->m_len -= extra; 2672 } 2673 } 2674 len = m0->m_pkthdr.len + sizeof(*nd_opt_rh); 2675 m0->m_pkthdr.len = m0->m_len = len - 2676 sizeof(*nd_opt_rh); 2677 } 2678 2679 nd_opt_rh = (struct nd_opt_rd_hdr *)p; 2680 bzero(nd_opt_rh, sizeof(*nd_opt_rh)); 2681 nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER; 2682 nd_opt_rh->nd_opt_rh_len = len >> 3; 2683 p += sizeof(*nd_opt_rh); 2684 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2685 2686 /* connect m0 to m */ 2687 m_tag_delete_chain(m0, NULL); 2688 m0->m_flags &= ~M_PKTHDR; 2689 m->m_next = m0; 2690 m->m_pkthdr.len = m->m_len + m0->m_len; 2691 m0 = NULL; 2692 } 2693 noredhdropt:; 2694 if (m0) { 2695 m_freem(m0); 2696 m0 = NULL; 2697 } 2698 2699 /* XXX: clear embedded link IDs in the inner header */ 2700 in6_clearscope(&sip6->ip6_src); 2701 in6_clearscope(&sip6->ip6_dst); 2702 in6_clearscope(&nd_rd->nd_rd_target); 2703 in6_clearscope(&nd_rd->nd_rd_dst); 2704 2705 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr)); 2706 2707 nd_rd->nd_rd_cksum = 0; 2708 nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2709 sizeof(*ip6), ntohs(ip6->ip6_plen)); 2710 2711 /* send the packet to outside... */ 2712 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2713 if (outif) { 2714 icmp6_ifstat_inc(outif, ifs6_out_msg); 2715 icmp6_ifstat_inc(outif, ifs6_out_redirect); 2716 } 2717 icmp6stat.icp6s_outhist[ND_REDIRECT]++; 2718 2719 return; 2720 2721 fail: 2722 if (m) 2723 m_freem(m); 2724 if (m0) 2725 m_freem(m0); 2726 } 2727 2728 /* 2729 * ICMPv6 socket option processing. 2730 */ 2731 int 2732 icmp6_ctloutput(so, sopt) 2733 struct socket *so; 2734 struct sockopt *sopt; 2735 { 2736 int error = 0; 2737 int optlen; 2738 struct inpcb *inp = sotoinpcb(so); 2739 int level, op, optname; 2740 2741 if (sopt) { 2742 level = sopt->sopt_level; 2743 op = sopt->sopt_dir; 2744 optname = sopt->sopt_name; 2745 optlen = sopt->sopt_valsize; 2746 } else 2747 level = op = optname = optlen = 0; 2748 2749 if (level != IPPROTO_ICMPV6) { 2750 return EINVAL; 2751 } 2752 2753 switch (op) { 2754 case PRCO_SETOPT: 2755 switch (optname) { 2756 case ICMP6_FILTER: 2757 { 2758 struct icmp6_filter *p; 2759 2760 if (optlen != sizeof(*p)) { 2761 error = EMSGSIZE; 2762 break; 2763 } 2764 if (inp->in6p_icmp6filt == NULL) { 2765 error = EINVAL; 2766 break; 2767 } 2768 error = sooptcopyin(sopt, inp->in6p_icmp6filt, optlen, 2769 optlen); 2770 break; 2771 } 2772 2773 default: 2774 error = ENOPROTOOPT; 2775 break; 2776 } 2777 break; 2778 2779 case PRCO_GETOPT: 2780 switch (optname) { 2781 case ICMP6_FILTER: 2782 { 2783 if (inp->in6p_icmp6filt == NULL) { 2784 error = EINVAL; 2785 break; 2786 } 2787 error = sooptcopyout(sopt, inp->in6p_icmp6filt, 2788 sizeof(struct icmp6_filter)); 2789 break; 2790 } 2791 2792 default: 2793 error = ENOPROTOOPT; 2794 break; 2795 } 2796 break; 2797 } 2798 2799 return (error); 2800 } 2801 2802 /* 2803 * Perform rate limit check. 2804 * Returns 0 if it is okay to send the icmp6 packet. 2805 * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate 2806 * limitation. 2807 * 2808 * XXX per-destination/type check necessary? 2809 */ 2810 static int 2811 icmp6_ratelimit(dst, type, code) 2812 const struct in6_addr *dst; /* not used at this moment */ 2813 const int type; /* not used at this moment */ 2814 const int code; /* not used at this moment */ 2815 { 2816 int ret; 2817 2818 ret = 0; /* okay to send */ 2819 2820 /* PPS limit */ 2821 if (!ppsratecheck(&icmp6errppslim_last, &icmp6errpps_count, 2822 icmp6errppslim)) { 2823 /* The packet is subject to rate limit */ 2824 ret++; 2825 } 2826 2827 return ret; 2828 } 2829