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 * 3. All advertising materials mentioning features or use of this software 46 * must display the following acknowledgement: 47 * This product includes software developed by the University of 48 * California, Berkeley and its contributors. 49 * 4. Neither the name of the University nor the names of its contributors 50 * may be used to endorse or promote products derived from this software 51 * without specific prior written permission. 52 * 53 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 54 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 55 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 56 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 57 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 58 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 59 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 60 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 61 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 62 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 63 * SUCH DAMAGE. 64 * 65 * @(#)ip_icmp.c 8.2 (Berkeley) 1/4/94 66 */ 67 68 #include "opt_inet.h" 69 #include "opt_inet6.h" 70 #include "opt_ipsec.h" 71 72 #include <sys/param.h> 73 #include <sys/domain.h> 74 #include <sys/kernel.h> 75 #include <sys/lock.h> 76 #include <sys/malloc.h> 77 #include <sys/mbuf.h> 78 #include <sys/protosw.h> 79 #include <sys/signalvar.h> 80 #include <sys/socket.h> 81 #include <sys/socketvar.h> 82 #include <sys/sx.h> 83 #include <sys/syslog.h> 84 #include <sys/systm.h> 85 #include <sys/time.h> 86 87 #include <net/if.h> 88 #include <net/if_dl.h> 89 #include <net/if_types.h> 90 #include <net/route.h> 91 92 #include <netinet/in.h> 93 #include <netinet/in_pcb.h> 94 #include <netinet/in_var.h> 95 #include <netinet/ip6.h> 96 #include <netinet/icmp6.h> 97 #include <netinet/tcp_var.h> 98 #include <netinet6/in6_ifattach.h> 99 #include <netinet6/in6_pcb.h> 100 #include <netinet6/ip6protosw.h> 101 #include <netinet6/ip6_var.h> 102 #include <netinet6/mld6_var.h> 103 #include <netinet6/nd6.h> 104 105 #ifdef IPSEC 106 #include <netinet6/ipsec.h> 107 #include <netkey/key.h> 108 #endif 109 110 #ifdef FAST_IPSEC 111 #include <netipsec/ipsec.h> 112 #include <netipsec/key.h> 113 #endif 114 115 #include <net/net_osdep.h> 116 117 extern struct domain inet6domain; 118 119 struct icmp6stat icmp6stat; 120 121 extern struct inpcbhead ripcb; 122 extern int icmp6errppslim; 123 static int icmp6errpps_count = 0; 124 static struct timeval icmp6errppslim_last; 125 extern int icmp6_nodeinfo; 126 127 static void icmp6_errcount __P((struct icmp6errstat *, int, int)); 128 static int icmp6_rip6_input __P((struct mbuf **, int)); 129 static int icmp6_ratelimit __P((const struct in6_addr *, const int, const int)); 130 static const char *icmp6_redirect_diag __P((struct in6_addr *, 131 struct in6_addr *, struct in6_addr *)); 132 static struct mbuf *ni6_input __P((struct mbuf *, int)); 133 static struct mbuf *ni6_nametodns __P((const char *, int, int)); 134 static int ni6_dnsmatch __P((const char *, int, const char *, int)); 135 static int ni6_addrs __P((struct icmp6_nodeinfo *, struct mbuf *, 136 struct ifnet **, char *)); 137 static int ni6_store_addrs __P((struct icmp6_nodeinfo *, struct icmp6_nodeinfo *, 138 struct ifnet *, int)); 139 static int icmp6_notify_error __P((struct mbuf *, int, int, int)); 140 141 #ifdef COMPAT_RFC1885 142 static struct route_in6 icmp6_reflect_rt; 143 #endif 144 145 146 void 147 icmp6_init() 148 { 149 mld6_init(); 150 } 151 152 static void 153 icmp6_errcount(stat, type, code) 154 struct icmp6errstat *stat; 155 int type, code; 156 { 157 switch (type) { 158 case ICMP6_DST_UNREACH: 159 switch (code) { 160 case ICMP6_DST_UNREACH_NOROUTE: 161 stat->icp6errs_dst_unreach_noroute++; 162 return; 163 case ICMP6_DST_UNREACH_ADMIN: 164 stat->icp6errs_dst_unreach_admin++; 165 return; 166 case ICMP6_DST_UNREACH_BEYONDSCOPE: 167 stat->icp6errs_dst_unreach_beyondscope++; 168 return; 169 case ICMP6_DST_UNREACH_ADDR: 170 stat->icp6errs_dst_unreach_addr++; 171 return; 172 case ICMP6_DST_UNREACH_NOPORT: 173 stat->icp6errs_dst_unreach_noport++; 174 return; 175 } 176 break; 177 case ICMP6_PACKET_TOO_BIG: 178 stat->icp6errs_packet_too_big++; 179 return; 180 case ICMP6_TIME_EXCEEDED: 181 switch (code) { 182 case ICMP6_TIME_EXCEED_TRANSIT: 183 stat->icp6errs_time_exceed_transit++; 184 return; 185 case ICMP6_TIME_EXCEED_REASSEMBLY: 186 stat->icp6errs_time_exceed_reassembly++; 187 return; 188 } 189 break; 190 case ICMP6_PARAM_PROB: 191 switch (code) { 192 case ICMP6_PARAMPROB_HEADER: 193 stat->icp6errs_paramprob_header++; 194 return; 195 case ICMP6_PARAMPROB_NEXTHEADER: 196 stat->icp6errs_paramprob_nextheader++; 197 return; 198 case ICMP6_PARAMPROB_OPTION: 199 stat->icp6errs_paramprob_option++; 200 return; 201 } 202 break; 203 case ND_REDIRECT: 204 stat->icp6errs_redirect++; 205 return; 206 } 207 stat->icp6errs_unknown++; 208 } 209 210 /* 211 * Generate an error packet of type error in response to bad IP6 packet. 212 */ 213 void 214 icmp6_error(m, type, code, param) 215 struct mbuf *m; 216 int type, code, param; 217 { 218 struct ip6_hdr *oip6, *nip6; 219 struct icmp6_hdr *icmp6; 220 u_int preplen; 221 int off; 222 int nxt; 223 224 icmp6stat.icp6s_error++; 225 226 /* count per-type-code statistics */ 227 icmp6_errcount(&icmp6stat.icp6s_outerrhist, type, code); 228 229 #ifdef M_DECRYPTED /*not openbsd*/ 230 if (m->m_flags & M_DECRYPTED) { 231 icmp6stat.icp6s_canterror++; 232 goto freeit; 233 } 234 #endif 235 236 #ifndef PULLDOWN_TEST 237 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), ); 238 #else 239 if (m->m_len < sizeof(struct ip6_hdr)) { 240 m = m_pullup(m, sizeof(struct ip6_hdr)); 241 if (m == NULL) 242 return; 243 } 244 #endif 245 oip6 = mtod(m, struct ip6_hdr *); 246 247 /* 248 * If the destination address of the erroneous packet is a multicast 249 * address, or the packet was sent using link-layer multicast, 250 * we should basically suppress sending an error (RFC 2463, Section 251 * 2.4). 252 * We have two exceptions (the item e.2 in that section): 253 * - the Pakcet Too Big message can be sent for path MTU discovery. 254 * - the Parameter Problem Message that can be allowed an icmp6 error 255 * in the option type field. This check has been done in 256 * ip6_unknown_opt(), so we can just check the type and code. 257 */ 258 if ((m->m_flags & (M_BCAST|M_MCAST) || 259 IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) && 260 (type != ICMP6_PACKET_TOO_BIG && 261 (type != ICMP6_PARAM_PROB || 262 code != ICMP6_PARAMPROB_OPTION))) 263 goto freeit; 264 265 /* 266 * RFC 2463, 2.4 (e.5): source address check. 267 * XXX: the case of anycast source? 268 */ 269 if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) || 270 IN6_IS_ADDR_MULTICAST(&oip6->ip6_src)) 271 goto freeit; 272 273 /* 274 * If we are about to send ICMPv6 against ICMPv6 error/redirect, 275 * don't do it. 276 */ 277 nxt = -1; 278 off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt); 279 if (off >= 0 && nxt == IPPROTO_ICMPV6) { 280 struct icmp6_hdr *icp; 281 282 #ifndef PULLDOWN_TEST 283 IP6_EXTHDR_CHECK(m, 0, off + sizeof(struct icmp6_hdr), ); 284 icp = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 285 #else 286 IP6_EXTHDR_GET(icp, struct icmp6_hdr *, m, off, 287 sizeof(*icp)); 288 if (icp == NULL) { 289 icmp6stat.icp6s_tooshort++; 290 return; 291 } 292 #endif 293 if (icp->icmp6_type < ICMP6_ECHO_REQUEST || 294 icp->icmp6_type == ND_REDIRECT) { 295 /* 296 * ICMPv6 error 297 * Special case: for redirect (which is 298 * informational) we must not send icmp6 error. 299 */ 300 icmp6stat.icp6s_canterror++; 301 goto freeit; 302 } else { 303 /* ICMPv6 informational - send the error */ 304 } 305 } else { 306 /* non-ICMPv6 - send the error */ 307 } 308 309 oip6 = mtod(m, struct ip6_hdr *); /* adjust pointer */ 310 311 /* Finally, do rate limitation check. */ 312 if (icmp6_ratelimit(&oip6->ip6_src, type, code)) { 313 icmp6stat.icp6s_toofreq++; 314 goto freeit; 315 } 316 317 /* 318 * OK, ICMP6 can be generated. 319 */ 320 321 if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN) 322 m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len); 323 324 preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 325 M_PREPEND(m, preplen, M_DONTWAIT); 326 if (m && m->m_len < preplen) 327 m = m_pullup(m, preplen); 328 if (m == NULL) { 329 nd6log((LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__)); 330 return; 331 } 332 333 nip6 = mtod(m, struct ip6_hdr *); 334 nip6->ip6_src = oip6->ip6_src; 335 nip6->ip6_dst = oip6->ip6_dst; 336 337 in6_clearscope(&oip6->ip6_src); 338 in6_clearscope(&oip6->ip6_dst); 339 340 icmp6 = (struct icmp6_hdr *)(nip6 + 1); 341 icmp6->icmp6_type = type; 342 icmp6->icmp6_code = code; 343 icmp6->icmp6_pptr = htonl((u_int32_t)param); 344 345 /* 346 * icmp6_reflect() is designed to be in the input path. 347 * icmp6_error() can be called from both input and outut path, 348 * and if we are in output path rcvif could contain bogus value. 349 * clear m->m_pkthdr.rcvif for safety, we should have enough scope 350 * information in ip header (nip6). 351 */ 352 m->m_pkthdr.rcvif = NULL; 353 354 icmp6stat.icp6s_outhist[type]++; 355 icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */ 356 357 return; 358 359 freeit: 360 /* 361 * If we can't tell wheter or not we can generate ICMP6, free it. 362 */ 363 m_freem(m); 364 } 365 366 /* 367 * Process a received ICMP6 message. 368 */ 369 int 370 icmp6_input(mp, offp, proto) 371 struct mbuf **mp; 372 int *offp, proto; 373 { 374 struct mbuf *m = *mp, *n; 375 struct ip6_hdr *ip6, *nip6; 376 struct icmp6_hdr *icmp6, *nicmp6; 377 int off = *offp; 378 int icmp6len = m->m_pkthdr.len - *offp; 379 int code, sum, noff; 380 381 #ifndef PULLDOWN_TEST 382 IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_hdr), IPPROTO_DONE); 383 /* m might change if M_LOOP. So, call mtod after this */ 384 #endif 385 386 /* 387 * Locate icmp6 structure in mbuf, and check 388 * that not corrupted and of at least minimum length 389 */ 390 391 ip6 = mtod(m, struct ip6_hdr *); 392 if (icmp6len < sizeof(struct icmp6_hdr)) { 393 icmp6stat.icp6s_tooshort++; 394 goto freeit; 395 } 396 397 /* 398 * calculate the checksum 399 */ 400 #ifndef PULLDOWN_TEST 401 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off); 402 #else 403 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6)); 404 if (icmp6 == NULL) { 405 icmp6stat.icp6s_tooshort++; 406 return IPPROTO_DONE; 407 } 408 #endif 409 code = icmp6->icmp6_code; 410 411 if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) { 412 nd6log((LOG_ERR, 413 "ICMP6 checksum error(%d|%x) %s\n", 414 icmp6->icmp6_type, sum, ip6_sprintf(&ip6->ip6_src))); 415 icmp6stat.icp6s_checksum++; 416 goto freeit; 417 } 418 419 if (faithprefix_p != NULL && (*faithprefix_p)(&ip6->ip6_dst)) { 420 /* 421 * Deliver very specific ICMP6 type only. 422 * This is important to deilver TOOBIG. Otherwise PMTUD 423 * will not work. 424 */ 425 switch (icmp6->icmp6_type) { 426 case ICMP6_DST_UNREACH: 427 case ICMP6_PACKET_TOO_BIG: 428 case ICMP6_TIME_EXCEEDED: 429 break; 430 default: 431 goto freeit; 432 } 433 } 434 435 icmp6stat.icp6s_inhist[icmp6->icmp6_type]++; 436 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_msg); 437 if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK) 438 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_error); 439 440 switch (icmp6->icmp6_type) { 441 case ICMP6_DST_UNREACH: 442 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_dstunreach); 443 switch (code) { 444 case ICMP6_DST_UNREACH_NOROUTE: 445 code = PRC_UNREACH_NET; 446 break; 447 case ICMP6_DST_UNREACH_ADMIN: 448 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_adminprohib); 449 code = PRC_UNREACH_PROTOCOL; /* is this a good code? */ 450 break; 451 case ICMP6_DST_UNREACH_ADDR: 452 code = PRC_HOSTDEAD; 453 break; 454 #ifdef COMPAT_RFC1885 455 case ICMP6_DST_UNREACH_NOTNEIGHBOR: 456 code = PRC_UNREACH_SRCFAIL; 457 break; 458 #else 459 case ICMP6_DST_UNREACH_BEYONDSCOPE: 460 /* I mean "source address was incorrect." */ 461 code = PRC_PARAMPROB; 462 break; 463 #endif 464 case ICMP6_DST_UNREACH_NOPORT: 465 code = PRC_UNREACH_PORT; 466 break; 467 default: 468 goto badcode; 469 } 470 goto deliver; 471 break; 472 473 case ICMP6_PACKET_TOO_BIG: 474 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_pkttoobig); 475 if (code != 0) 476 goto badcode; 477 478 /* validation is made in icmp6_mtudisc_update */ 479 480 code = PRC_MSGSIZE; 481 482 /* 483 * Updating the path MTU will be done after examining 484 * intermediate extension headers. 485 */ 486 goto deliver; 487 break; 488 489 case ICMP6_TIME_EXCEEDED: 490 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_timeexceed); 491 switch (code) { 492 case ICMP6_TIME_EXCEED_TRANSIT: 493 case ICMP6_TIME_EXCEED_REASSEMBLY: 494 code += PRC_TIMXCEED_INTRANS; 495 break; 496 default: 497 goto badcode; 498 } 499 goto deliver; 500 break; 501 502 case ICMP6_PARAM_PROB: 503 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_paramprob); 504 switch (code) { 505 case ICMP6_PARAMPROB_NEXTHEADER: 506 code = PRC_UNREACH_PROTOCOL; 507 break; 508 case ICMP6_PARAMPROB_HEADER: 509 case ICMP6_PARAMPROB_OPTION: 510 code = PRC_PARAMPROB; 511 break; 512 default: 513 goto badcode; 514 } 515 goto deliver; 516 break; 517 518 case ICMP6_ECHO_REQUEST: 519 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_echo); 520 if (code != 0) 521 goto badcode; 522 if ((n = m_copy(m, 0, M_COPYALL)) == NULL) { 523 /* Give up remote */ 524 break; 525 } 526 if ((n->m_flags & M_EXT) != 0 527 || n->m_len < off + sizeof(struct icmp6_hdr)) { 528 struct mbuf *n0 = n; 529 const int maxlen = sizeof(*nip6) + sizeof(*nicmp6); 530 int n0len; 531 532 /* 533 * Prepare an internal mbuf. m_pullup() doesn't 534 * always copy the length we specified. 535 */ 536 if (maxlen >= MCLBYTES) { 537 /* Give up remote */ 538 m_freem(n0); 539 break; 540 } 541 MGETHDR(n, M_DONTWAIT, n0->m_type); 542 n0len = n0->m_pkthdr.len; /* save for use below */ 543 if (n) 544 M_MOVE_PKTHDR(n, n0); 545 if (n && maxlen >= MHLEN) { 546 MCLGET(n, M_DONTWAIT); 547 if ((n->m_flags & M_EXT) == 0) { 548 m_free(n); 549 n = NULL; 550 } 551 } 552 if (n == NULL) { 553 /* Give up remote */ 554 m_freem(n0); 555 break; 556 } 557 /* 558 * Copy IPv6 and ICMPv6 only. 559 */ 560 nip6 = mtod(n, struct ip6_hdr *); 561 bcopy(ip6, nip6, sizeof(struct ip6_hdr)); 562 nicmp6 = (struct icmp6_hdr *)(nip6 + 1); 563 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr)); 564 noff = sizeof(struct ip6_hdr); 565 /* new mbuf contains only ipv6+icmpv6 headers */ 566 n->m_len = noff + sizeof(struct icmp6_hdr); 567 /* 568 * Adjust mbuf. ip6_plen will be adjusted in 569 * ip6_output(). 570 */ 571 m_adj(n0, off + sizeof(struct icmp6_hdr)); 572 /* recalculate complete packet size */ 573 n->m_pkthdr.len = n0len + (noff - off); 574 n->m_next = n0; 575 } else { 576 nip6 = mtod(n, struct ip6_hdr *); 577 nicmp6 = (struct icmp6_hdr *)((caddr_t)nip6 + off); 578 noff = off; 579 } 580 nicmp6->icmp6_type = ICMP6_ECHO_REPLY; 581 nicmp6->icmp6_code = 0; 582 if (n) { 583 icmp6stat.icp6s_reflect++; 584 icmp6stat.icp6s_outhist[ICMP6_ECHO_REPLY]++; 585 icmp6_reflect(n, noff); 586 } 587 break; 588 589 case ICMP6_ECHO_REPLY: 590 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_echoreply); 591 if (code != 0) 592 goto badcode; 593 break; 594 595 case MLD_LISTENER_QUERY: 596 case MLD_LISTENER_REPORT: 597 if (icmp6len < sizeof(struct mld_hdr)) 598 goto badlen; 599 if (icmp6->icmp6_type == MLD_LISTENER_QUERY) /* XXX: ugly... */ 600 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mldquery); 601 else 602 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mldreport); 603 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 604 /* give up local */ 605 mld6_input(m, off); 606 m = NULL; 607 goto freeit; 608 } 609 mld6_input(n, off); 610 /* m stays. */ 611 break; 612 613 case MLD_LISTENER_DONE: 614 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mlddone); 615 if (icmp6len < sizeof(struct mld_hdr)) /* necessary? */ 616 goto badlen; 617 break; /* nothing to be done in kernel */ 618 619 case MLD_MTRACE_RESP: 620 case MLD_MTRACE: 621 /* XXX: these two are experimental. not officially defined. */ 622 /* XXX: per-interface statistics? */ 623 break; /* just pass it to applications */ 624 625 case ICMP6_WRUREQUEST: /* ICMP6_FQDN_QUERY */ 626 { 627 enum { WRU, FQDN } mode; 628 629 if (!icmp6_nodeinfo) 630 break; 631 632 if (icmp6len == sizeof(struct icmp6_hdr) + 4) 633 mode = WRU; 634 else if (icmp6len >= sizeof(struct icmp6_nodeinfo)) 635 mode = FQDN; 636 else 637 goto badlen; 638 639 #define hostnamelen strlen(hostname) 640 if (mode == FQDN) { 641 #ifndef PULLDOWN_TEST 642 IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_nodeinfo), 643 IPPROTO_DONE); 644 #endif 645 n = m_copy(m, 0, M_COPYALL); 646 if (n) 647 n = ni6_input(n, off); 648 /* XXX meaningless if n == NULL */ 649 noff = sizeof(struct ip6_hdr); 650 } else { 651 u_char *p; 652 int maxlen, maxhlen; 653 654 if ((icmp6_nodeinfo & 5) != 5) 655 break; 656 657 if (code != 0) 658 goto badcode; 659 maxlen = sizeof(*nip6) + sizeof(*nicmp6) + 4; 660 if (maxlen >= MCLBYTES) { 661 /* Give up remote */ 662 break; 663 } 664 MGETHDR(n, M_DONTWAIT, m->m_type); 665 if (n && maxlen > MHLEN) { 666 MCLGET(n, M_DONTWAIT); 667 if ((n->m_flags & M_EXT) == 0) { 668 m_free(n); 669 n = NULL; 670 } 671 } 672 if (!m_dup_pkthdr(n, m, M_DONTWAIT)) { 673 /* 674 * Previous code did a blind M_COPY_PKTHDR 675 * and said "just for rcvif". If true, then 676 * we could tolerate the dup failing (due to 677 * the deep copy of the tag chain). For now 678 * be conservative and just fail. 679 */ 680 m_free(n); 681 n = NULL; 682 } 683 if (n == NULL) { 684 /* Give up remote */ 685 break; 686 } 687 n->m_pkthdr.rcvif = NULL; 688 n->m_len = 0; 689 maxhlen = M_TRAILINGSPACE(n) - maxlen; 690 if (maxhlen > hostnamelen) 691 maxhlen = hostnamelen; 692 /* 693 * Copy IPv6 and ICMPv6 only. 694 */ 695 nip6 = mtod(n, struct ip6_hdr *); 696 bcopy(ip6, nip6, sizeof(struct ip6_hdr)); 697 nicmp6 = (struct icmp6_hdr *)(nip6 + 1); 698 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr)); 699 p = (u_char *)(nicmp6 + 1); 700 bzero(p, 4); 701 bcopy(hostname, p + 4, maxhlen); /* meaningless TTL */ 702 noff = sizeof(struct ip6_hdr); 703 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + 704 sizeof(struct icmp6_hdr) + 4 + maxhlen; 705 nicmp6->icmp6_type = ICMP6_WRUREPLY; 706 nicmp6->icmp6_code = 0; 707 } 708 #undef hostnamelen 709 if (n) { 710 icmp6stat.icp6s_reflect++; 711 icmp6stat.icp6s_outhist[ICMP6_WRUREPLY]++; 712 icmp6_reflect(n, noff); 713 } 714 break; 715 } 716 717 case ICMP6_WRUREPLY: 718 if (code != 0) 719 goto badcode; 720 break; 721 722 case ND_ROUTER_SOLICIT: 723 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_routersolicit); 724 if (code != 0) 725 goto badcode; 726 if (icmp6len < sizeof(struct nd_router_solicit)) 727 goto badlen; 728 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 729 /* give up local */ 730 nd6_rs_input(m, off, icmp6len); 731 m = NULL; 732 goto freeit; 733 } 734 nd6_rs_input(n, off, icmp6len); 735 /* m stays. */ 736 break; 737 738 case ND_ROUTER_ADVERT: 739 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_routeradvert); 740 if (code != 0) 741 goto badcode; 742 if (icmp6len < sizeof(struct nd_router_advert)) 743 goto badlen; 744 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 745 /* give up local */ 746 nd6_ra_input(m, off, icmp6len); 747 m = NULL; 748 goto freeit; 749 } 750 nd6_ra_input(n, off, icmp6len); 751 /* m stays. */ 752 break; 753 754 case ND_NEIGHBOR_SOLICIT: 755 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_neighborsolicit); 756 if (code != 0) 757 goto badcode; 758 if (icmp6len < sizeof(struct nd_neighbor_solicit)) 759 goto badlen; 760 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 761 /* give up local */ 762 nd6_ns_input(m, off, icmp6len); 763 m = NULL; 764 goto freeit; 765 } 766 nd6_ns_input(n, off, icmp6len); 767 /* m stays. */ 768 break; 769 770 case ND_NEIGHBOR_ADVERT: 771 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_neighboradvert); 772 if (code != 0) 773 goto badcode; 774 if (icmp6len < sizeof(struct nd_neighbor_advert)) 775 goto badlen; 776 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 777 /* give up local */ 778 nd6_na_input(m, off, icmp6len); 779 m = NULL; 780 goto freeit; 781 } 782 nd6_na_input(n, off, icmp6len); 783 /* m stays. */ 784 break; 785 786 case ND_REDIRECT: 787 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_redirect); 788 if (code != 0) 789 goto badcode; 790 if (icmp6len < sizeof(struct nd_redirect)) 791 goto badlen; 792 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 793 /* give up local */ 794 icmp6_redirect_input(m, off); 795 m = NULL; 796 goto freeit; 797 } 798 icmp6_redirect_input(n, off); 799 /* m stays. */ 800 break; 801 802 case ICMP6_ROUTER_RENUMBERING: 803 if (code != ICMP6_ROUTER_RENUMBERING_COMMAND && 804 code != ICMP6_ROUTER_RENUMBERING_RESULT) 805 goto badcode; 806 if (icmp6len < sizeof(struct icmp6_router_renum)) 807 goto badlen; 808 break; 809 810 default: 811 nd6log((LOG_DEBUG, 812 "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n", 813 icmp6->icmp6_type, ip6_sprintf(&ip6->ip6_src), 814 ip6_sprintf(&ip6->ip6_dst), 815 m->m_pkthdr.rcvif ? m->m_pkthdr.rcvif->if_index : 0)); 816 if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) { 817 /* ICMPv6 error: MUST deliver it by spec... */ 818 code = PRC_NCMDS; 819 /* deliver */ 820 } else { 821 /* ICMPv6 informational: MUST not deliver */ 822 break; 823 } 824 deliver: 825 if (icmp6_notify_error(m, off, icmp6len, code)) { 826 /* In this case, m should've been freed. */ 827 return (IPPROTO_DONE); 828 } 829 break; 830 831 badcode: 832 icmp6stat.icp6s_badcode++; 833 break; 834 835 badlen: 836 icmp6stat.icp6s_badlen++; 837 break; 838 } 839 840 /* deliver the packet to appropriate sockets */ 841 icmp6_rip6_input(&m, *offp); 842 843 return IPPROTO_DONE; 844 845 freeit: 846 m_freem(m); 847 return IPPROTO_DONE; 848 } 849 850 static int 851 icmp6_notify_error(m, off, icmp6len, code) 852 struct mbuf *m; 853 int off, icmp6len, code; 854 { 855 struct icmp6_hdr *icmp6; 856 struct ip6_hdr *eip6; 857 u_int32_t notifymtu; 858 struct sockaddr_in6 icmp6src, icmp6dst; 859 860 if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) { 861 icmp6stat.icp6s_tooshort++; 862 goto freeit; 863 } 864 #ifndef PULLDOWN_TEST 865 IP6_EXTHDR_CHECK(m, off, 866 sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr), -1); 867 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 868 #else 869 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, 870 sizeof(*icmp6) + sizeof(struct ip6_hdr)); 871 if (icmp6 == NULL) { 872 icmp6stat.icp6s_tooshort++; 873 return (-1); 874 } 875 #endif 876 eip6 = (struct ip6_hdr *)(icmp6 + 1); 877 878 /* Detect the upper level protocol */ 879 { 880 void (*ctlfunc) __P((int, struct sockaddr *, void *)); 881 u_int8_t nxt = eip6->ip6_nxt; 882 int eoff = off + sizeof(struct icmp6_hdr) + 883 sizeof(struct ip6_hdr); 884 struct ip6ctlparam ip6cp; 885 struct in6_addr *finaldst = NULL; 886 int icmp6type = icmp6->icmp6_type; 887 struct ip6_frag *fh; 888 struct ip6_rthdr *rth; 889 struct ip6_rthdr0 *rth0; 890 int rthlen; 891 892 while (1) { /* XXX: should avoid infinite loop explicitly? */ 893 struct ip6_ext *eh; 894 895 switch (nxt) { 896 case IPPROTO_HOPOPTS: 897 case IPPROTO_DSTOPTS: 898 case IPPROTO_AH: 899 #ifndef PULLDOWN_TEST 900 IP6_EXTHDR_CHECK(m, 0, 901 eoff + sizeof(struct ip6_ext), -1); 902 eh = (struct ip6_ext *)(mtod(m, caddr_t) + eoff); 903 #else 904 IP6_EXTHDR_GET(eh, struct ip6_ext *, m, 905 eoff, sizeof(*eh)); 906 if (eh == NULL) { 907 icmp6stat.icp6s_tooshort++; 908 return (-1); 909 } 910 #endif 911 912 if (nxt == IPPROTO_AH) 913 eoff += (eh->ip6e_len + 2) << 2; 914 else 915 eoff += (eh->ip6e_len + 1) << 3; 916 nxt = eh->ip6e_nxt; 917 break; 918 case IPPROTO_ROUTING: 919 /* 920 * When the erroneous packet contains a 921 * routing header, we should examine the 922 * header to determine the final destination. 923 * Otherwise, we can't properly update 924 * information that depends on the final 925 * destination (e.g. path MTU). 926 */ 927 #ifndef PULLDOWN_TEST 928 IP6_EXTHDR_CHECK(m, 0, eoff + sizeof(*rth), -1); 929 rth = (struct ip6_rthdr *) 930 (mtod(m, caddr_t) + eoff); 931 #else 932 IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m, 933 eoff, sizeof(*rth)); 934 if (rth == NULL) { 935 icmp6stat.icp6s_tooshort++; 936 return (-1); 937 } 938 #endif 939 rthlen = (rth->ip6r_len + 1) << 3; 940 /* 941 * XXX: currently there is no 942 * officially defined type other 943 * than type-0. 944 * Note that if the segment left field 945 * is 0, all intermediate hops must 946 * have been passed. 947 */ 948 if (rth->ip6r_segleft && 949 rth->ip6r_type == IPV6_RTHDR_TYPE_0) { 950 int hops; 951 952 #ifndef PULLDOWN_TEST 953 IP6_EXTHDR_CHECK(m, 0, eoff + rthlen, -1); 954 rth0 = (struct ip6_rthdr0 *) 955 (mtod(m, caddr_t) + eoff); 956 #else 957 IP6_EXTHDR_GET(rth0, 958 struct ip6_rthdr0 *, m, 959 eoff, rthlen); 960 if (rth0 == NULL) { 961 icmp6stat.icp6s_tooshort++; 962 return (-1); 963 } 964 #endif 965 /* just ignore a bogus header */ 966 if ((rth0->ip6r0_len % 2) == 0 && 967 (hops = rth0->ip6r0_len/2)) 968 finaldst = (struct in6_addr *)(rth0 + 1) + (hops - 1); 969 } 970 eoff += rthlen; 971 nxt = rth->ip6r_nxt; 972 break; 973 case IPPROTO_FRAGMENT: 974 #ifndef PULLDOWN_TEST 975 IP6_EXTHDR_CHECK(m, 0, eoff + 976 sizeof(struct ip6_frag), -1); 977 fh = (struct ip6_frag *)(mtod(m, caddr_t) + 978 eoff); 979 #else 980 IP6_EXTHDR_GET(fh, struct ip6_frag *, m, 981 eoff, sizeof(*fh)); 982 if (fh == NULL) { 983 icmp6stat.icp6s_tooshort++; 984 return (-1); 985 } 986 #endif 987 /* 988 * Data after a fragment header is meaningless 989 * unless it is the first fragment, but 990 * we'll go to the notify label for path MTU 991 * discovery. 992 */ 993 if (fh->ip6f_offlg & IP6F_OFF_MASK) 994 goto notify; 995 996 eoff += sizeof(struct ip6_frag); 997 nxt = fh->ip6f_nxt; 998 break; 999 default: 1000 /* 1001 * This case includes ESP and the No Next 1002 * Header. In such cases going to the notify 1003 * label does not have any meaning 1004 * (i.e. ctlfunc will be NULL), but we go 1005 * anyway since we might have to update 1006 * path MTU information. 1007 */ 1008 goto notify; 1009 } 1010 } 1011 notify: 1012 #ifndef PULLDOWN_TEST 1013 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 1014 #else 1015 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, 1016 sizeof(*icmp6) + sizeof(struct ip6_hdr)); 1017 if (icmp6 == NULL) { 1018 icmp6stat.icp6s_tooshort++; 1019 return (-1); 1020 } 1021 #endif 1022 1023 /* 1024 * retrieve parameters from the inner IPv6 header, and convert 1025 * them into sockaddr structures. 1026 * XXX: there is no guarantee that the source or destination 1027 * addresses of the inner packet are in the same scope as 1028 * the addresses of the icmp packet. But there is no other 1029 * way to determine the zone. 1030 */ 1031 eip6 = (struct ip6_hdr *)(icmp6 + 1); 1032 1033 bzero(&icmp6dst, sizeof(icmp6dst)); 1034 icmp6dst.sin6_len = sizeof(struct sockaddr_in6); 1035 icmp6dst.sin6_family = AF_INET6; 1036 if (finaldst == NULL) 1037 icmp6dst.sin6_addr = eip6->ip6_dst; 1038 else 1039 icmp6dst.sin6_addr = *finaldst; 1040 if (in6_addr2zoneid(m->m_pkthdr.rcvif, &icmp6dst.sin6_addr, 1041 &icmp6dst.sin6_scope_id)) 1042 goto freeit; 1043 if (in6_embedscope(&icmp6dst.sin6_addr, &icmp6dst, 1044 NULL, NULL)) { 1045 /* should be impossbile */ 1046 nd6log((LOG_DEBUG, 1047 "icmp6_notify_error: in6_embedscope failed\n")); 1048 goto freeit; 1049 } 1050 1051 /* 1052 * retrieve parameters from the inner IPv6 header, and convert 1053 * them into sockaddr structures. 1054 */ 1055 bzero(&icmp6src, sizeof(icmp6src)); 1056 icmp6src.sin6_len = sizeof(struct sockaddr_in6); 1057 icmp6src.sin6_family = AF_INET6; 1058 icmp6src.sin6_addr = eip6->ip6_src; 1059 if (in6_addr2zoneid(m->m_pkthdr.rcvif, &icmp6src.sin6_addr, 1060 &icmp6src.sin6_scope_id)) { 1061 goto freeit; 1062 } 1063 if (in6_embedscope(&icmp6src.sin6_addr, &icmp6src, 1064 NULL, NULL)) { 1065 /* should be impossbile */ 1066 nd6log((LOG_DEBUG, 1067 "icmp6_notify_error: in6_embedscope failed\n")); 1068 goto freeit; 1069 } 1070 icmp6src.sin6_flowinfo = (eip6->ip6_flow & IPV6_FLOWLABEL_MASK); 1071 1072 if (finaldst == NULL) 1073 finaldst = &eip6->ip6_dst; 1074 ip6cp.ip6c_m = m; 1075 ip6cp.ip6c_icmp6 = icmp6; 1076 ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1); 1077 ip6cp.ip6c_off = eoff; 1078 ip6cp.ip6c_finaldst = finaldst; 1079 ip6cp.ip6c_src = &icmp6src; 1080 ip6cp.ip6c_nxt = nxt; 1081 1082 if (icmp6type == ICMP6_PACKET_TOO_BIG) { 1083 notifymtu = ntohl(icmp6->icmp6_mtu); 1084 ip6cp.ip6c_cmdarg = (void *)¬ifymtu; 1085 icmp6_mtudisc_update(&ip6cp, 1); /*XXX*/ 1086 } 1087 1088 ctlfunc = (void (*) __P((int, struct sockaddr *, void *))) 1089 (inet6sw[ip6_protox[nxt]].pr_ctlinput); 1090 if (ctlfunc) { 1091 (void) (*ctlfunc)(code, (struct sockaddr *)&icmp6dst, 1092 &ip6cp); 1093 } 1094 } 1095 return (0); 1096 1097 freeit: 1098 m_freem(m); 1099 return (-1); 1100 } 1101 1102 void 1103 icmp6_mtudisc_update(ip6cp, validated) 1104 struct ip6ctlparam *ip6cp; 1105 int validated; 1106 { 1107 struct in6_addr *dst = ip6cp->ip6c_finaldst; 1108 struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6; 1109 struct mbuf *m = ip6cp->ip6c_m; /* will be necessary for scope issue */ 1110 u_int mtu = ntohl(icmp6->icmp6_mtu); 1111 struct in_conninfo inc; 1112 1113 #if 0 1114 /* 1115 * RFC2460 section 5, last paragraph. 1116 * even though minimum link MTU for IPv6 is IPV6_MMTU, 1117 * we may see ICMPv6 too big with mtu < IPV6_MMTU 1118 * due to packet translator in the middle. 1119 * see ip6_output() and ip6_getpmtu() "alwaysfrag" case for 1120 * special handling. 1121 */ 1122 if (mtu < IPV6_MMTU) 1123 return; 1124 #endif 1125 1126 /* 1127 * we reject ICMPv6 too big with abnormally small value. 1128 * XXX what is the good definition of "abnormally small"? 1129 */ 1130 if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8) 1131 return; 1132 1133 if (!validated) 1134 return; 1135 1136 bzero(&inc, sizeof(inc)); 1137 inc.inc_flags = 1; /* IPv6 */ 1138 inc.inc6_faddr = *dst; 1139 /* XXX normally, this won't happen */ 1140 if (IN6_IS_ADDR_LINKLOCAL(dst)) { 1141 inc.inc6_faddr.s6_addr16[1] = 1142 htons(m->m_pkthdr.rcvif->if_index); 1143 } 1144 1145 if (mtu < tcp_maxmtu6(&inc)) { 1146 tcp_hc_updatemtu(&inc, mtu); 1147 icmp6stat.icp6s_pmtuchg++; 1148 } 1149 } 1150 1151 /* 1152 * Process a Node Information Query packet, based on 1153 * draft-ietf-ipngwg-icmp-name-lookups-07. 1154 * 1155 * Spec incompatibilities: 1156 * - IPv6 Subject address handling 1157 * - IPv4 Subject address handling support missing 1158 * - Proxy reply (answer even if it's not for me) 1159 * - joins NI group address at in6_ifattach() time only, does not cope 1160 * with hostname changes by sethostname(3) 1161 */ 1162 #define hostnamelen strlen(hostname) 1163 static struct mbuf * 1164 ni6_input(m, off) 1165 struct mbuf *m; 1166 int off; 1167 { 1168 struct icmp6_nodeinfo *ni6, *nni6; 1169 struct mbuf *n = NULL; 1170 u_int16_t qtype; 1171 int subjlen; 1172 int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); 1173 struct ni_reply_fqdn *fqdn; 1174 int addrs; /* for NI_QTYPE_NODEADDR */ 1175 struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */ 1176 struct sockaddr_in6 sin6_sbj; /* subject address */ 1177 struct sockaddr_in6 sin6_d; 1178 struct ip6_hdr *ip6; 1179 int oldfqdn = 0; /* if 1, return pascal string (03 draft) */ 1180 char *subj = NULL; 1181 struct in6_ifaddr *ia6 = NULL; 1182 1183 ip6 = mtod(m, struct ip6_hdr *); 1184 #ifndef PULLDOWN_TEST 1185 ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off); 1186 #else 1187 IP6_EXTHDR_GET(ni6, struct icmp6_nodeinfo *, m, off, sizeof(*ni6)); 1188 if (ni6 == NULL) { 1189 /* m is already reclaimed */ 1190 return (NULL); 1191 } 1192 #endif 1193 1194 bzero(&sin6_d, sizeof(sin6_d)); 1195 sin6_d.sin6_family = AF_INET6; /* not used, actually */ 1196 sin6_d.sin6_len = sizeof(sin6_d); /* ditto */ 1197 sin6_d.sin6_addr = ip6->ip6_dst; 1198 if (in6_addr2zoneid(m->m_pkthdr.rcvif, &ip6->ip6_dst, 1199 &sin6_d.sin6_scope_id)) { 1200 goto bad; 1201 } 1202 if (in6_embedscope(&sin6_d.sin6_addr, &sin6_d, NULL, NULL)) 1203 goto bad; /* XXX should not happen */ 1204 1205 /* 1206 * Validate IPv6 destination address. 1207 * 1208 * The Responder must discard the Query without further processing 1209 * unless it is one of the Responder's unicast or anycast addresses, or 1210 * a link-local scope multicast address which the Responder has joined. 1211 * [icmp-name-lookups-08, Section 4.] 1212 */ 1213 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 1214 if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst)) 1215 goto bad; 1216 /* else it's a link-local multicast, fine */ 1217 } else { /* unicast or anycast */ 1218 if ((ia6 = ip6_getdstifaddr(m)) == NULL) 1219 goto bad; /* XXX impossible */ 1220 1221 if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) && 1222 !(icmp6_nodeinfo & 4)) { 1223 nd6log((LOG_DEBUG, "ni6_input: ignore node info to " 1224 "a temporary address in %s:%d", 1225 __FILE__, __LINE__)); 1226 goto bad; 1227 } 1228 } 1229 1230 /* validate query Subject field. */ 1231 qtype = ntohs(ni6->ni_qtype); 1232 subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo); 1233 switch (qtype) { 1234 case NI_QTYPE_NOOP: 1235 case NI_QTYPE_SUPTYPES: 1236 /* 07 draft */ 1237 if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0) 1238 break; 1239 /* FALLTHROUGH */ 1240 case NI_QTYPE_FQDN: 1241 case NI_QTYPE_NODEADDR: 1242 switch (ni6->ni_code) { 1243 case ICMP6_NI_SUBJ_IPV6: 1244 #if ICMP6_NI_SUBJ_IPV6 != 0 1245 case 0: 1246 #endif 1247 /* 1248 * backward compatibility - try to accept 03 draft 1249 * format, where no Subject is present. 1250 */ 1251 if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 && 1252 subjlen == 0) { 1253 oldfqdn++; 1254 break; 1255 } 1256 #if ICMP6_NI_SUBJ_IPV6 != 0 1257 if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6) 1258 goto bad; 1259 #endif 1260 1261 if (subjlen != sizeof(struct in6_addr)) 1262 goto bad; 1263 1264 /* 1265 * Validate Subject address. 1266 * 1267 * Not sure what exactly "address belongs to the node" 1268 * means in the spec, is it just unicast, or what? 1269 * 1270 * At this moment we consider Subject address as 1271 * "belong to the node" if the Subject address equals 1272 * to the IPv6 destination address; validation for 1273 * IPv6 destination address should have done enough 1274 * check for us. 1275 * 1276 * We do not do proxy at this moment. 1277 */ 1278 /* m_pulldown instead of copy? */ 1279 bzero(&sin6_sbj, sizeof(sin6_sbj)); 1280 sin6_sbj.sin6_family = AF_INET6; 1281 sin6_sbj.sin6_len = sizeof(sin6_sbj); 1282 m_copydata(m, off + sizeof(struct icmp6_nodeinfo), 1283 subjlen, (caddr_t)&sin6_sbj.sin6_addr); 1284 if (in6_addr2zoneid(m->m_pkthdr.rcvif, 1285 &sin6_sbj.sin6_addr, &sin6_sbj.sin6_scope_id)) { 1286 goto bad; 1287 } 1288 if (in6_embedscope(&sin6_sbj.sin6_addr, &sin6_sbj, 1289 NULL, NULL)) 1290 goto bad; /* XXX should not happen */ 1291 1292 subj = (char *)&sin6_sbj; 1293 if (SA6_ARE_ADDR_EQUAL(&sin6_sbj, &sin6_d)) 1294 break; 1295 1296 /* 1297 * XXX if we are to allow other cases, we should really 1298 * be careful about scope here. 1299 * basically, we should disallow queries toward IPv6 1300 * destination X with subject Y, 1301 * if scope(X) > scope(Y). 1302 * if we allow scope(X) > scope(Y), it will result in 1303 * information leakage across scope boundary. 1304 */ 1305 goto bad; 1306 1307 case ICMP6_NI_SUBJ_FQDN: 1308 /* 1309 * Validate Subject name with gethostname(3). 1310 * 1311 * The behavior may need some debate, since: 1312 * - we are not sure if the node has FQDN as 1313 * hostname (returned by gethostname(3)). 1314 * - the code does wildcard match for truncated names. 1315 * however, we are not sure if we want to perform 1316 * wildcard match, if gethostname(3) side has 1317 * truncated hostname. 1318 */ 1319 n = ni6_nametodns(hostname, hostnamelen, 0); 1320 if (!n || n->m_next || n->m_len == 0) 1321 goto bad; 1322 IP6_EXTHDR_GET(subj, char *, m, 1323 off + sizeof(struct icmp6_nodeinfo), subjlen); 1324 if (subj == NULL) 1325 goto bad; 1326 if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *), 1327 n->m_len)) { 1328 goto bad; 1329 } 1330 m_freem(n); 1331 n = NULL; 1332 break; 1333 1334 case ICMP6_NI_SUBJ_IPV4: /* XXX: to be implemented? */ 1335 default: 1336 goto bad; 1337 } 1338 break; 1339 } 1340 1341 /* refuse based on configuration. XXX ICMP6_NI_REFUSED? */ 1342 switch (qtype) { 1343 case NI_QTYPE_FQDN: 1344 if ((icmp6_nodeinfo & 1) == 0) 1345 goto bad; 1346 break; 1347 case NI_QTYPE_NODEADDR: 1348 if ((icmp6_nodeinfo & 2) == 0) 1349 goto bad; 1350 break; 1351 } 1352 1353 /* guess reply length */ 1354 switch (qtype) { 1355 case NI_QTYPE_NOOP: 1356 break; /* no reply data */ 1357 case NI_QTYPE_SUPTYPES: 1358 replylen += sizeof(u_int32_t); 1359 break; 1360 case NI_QTYPE_FQDN: 1361 /* XXX will append an mbuf */ 1362 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); 1363 break; 1364 case NI_QTYPE_NODEADDR: 1365 addrs = ni6_addrs(ni6, m, &ifp, subj); 1366 if ((replylen += addrs * (sizeof(struct in6_addr) + 1367 sizeof(u_int32_t))) > MCLBYTES) 1368 replylen = MCLBYTES; /* XXX: will truncate pkt later */ 1369 break; 1370 default: 1371 /* 1372 * XXX: We must return a reply with the ICMP6 code 1373 * `unknown Qtype' in this case. However we regard the case 1374 * as an FQDN query for backward compatibility. 1375 * Older versions set a random value to this field, 1376 * so it rarely varies in the defined qtypes. 1377 * But the mechanism is not reliable... 1378 * maybe we should obsolete older versions. 1379 */ 1380 qtype = NI_QTYPE_FQDN; 1381 /* XXX will append an mbuf */ 1382 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); 1383 oldfqdn++; 1384 break; 1385 } 1386 1387 /* allocate an mbuf to reply. */ 1388 MGETHDR(n, M_DONTWAIT, m->m_type); 1389 if (n == NULL) { 1390 m_freem(m); 1391 return (NULL); 1392 } 1393 M_MOVE_PKTHDR(n, m); /* just for recvif */ 1394 if (replylen > MHLEN) { 1395 if (replylen > MCLBYTES) { 1396 /* 1397 * XXX: should we try to allocate more? But MCLBYTES 1398 * is probably much larger than IPV6_MMTU... 1399 */ 1400 goto bad; 1401 } 1402 MCLGET(n, M_DONTWAIT); 1403 if ((n->m_flags & M_EXT) == 0) { 1404 goto bad; 1405 } 1406 } 1407 n->m_pkthdr.len = n->m_len = replylen; 1408 1409 /* copy mbuf header and IPv6 + Node Information base headers */ 1410 bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr)); 1411 nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1); 1412 bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo)); 1413 1414 /* qtype dependent procedure */ 1415 switch (qtype) { 1416 case NI_QTYPE_NOOP: 1417 nni6->ni_code = ICMP6_NI_SUCCESS; 1418 nni6->ni_flags = 0; 1419 break; 1420 case NI_QTYPE_SUPTYPES: 1421 { 1422 u_int32_t v; 1423 nni6->ni_code = ICMP6_NI_SUCCESS; 1424 nni6->ni_flags = htons(0x0000); /* raw bitmap */ 1425 /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */ 1426 v = (u_int32_t)htonl(0x0000000f); 1427 bcopy(&v, nni6 + 1, sizeof(u_int32_t)); 1428 break; 1429 } 1430 case NI_QTYPE_FQDN: 1431 nni6->ni_code = ICMP6_NI_SUCCESS; 1432 fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) + 1433 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo)); 1434 nni6->ni_flags = 0; /* XXX: meaningless TTL */ 1435 fqdn->ni_fqdn_ttl = 0; /* ditto. */ 1436 /* 1437 * XXX do we really have FQDN in variable "hostname"? 1438 */ 1439 n->m_next = ni6_nametodns(hostname, hostnamelen, oldfqdn); 1440 if (n->m_next == NULL) 1441 goto bad; 1442 /* XXX we assume that n->m_next is not a chain */ 1443 if (n->m_next->m_next != NULL) 1444 goto bad; 1445 n->m_pkthdr.len += n->m_next->m_len; 1446 break; 1447 case NI_QTYPE_NODEADDR: 1448 { 1449 int lenlim, copied; 1450 1451 nni6->ni_code = ICMP6_NI_SUCCESS; 1452 n->m_pkthdr.len = n->m_len = 1453 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); 1454 lenlim = M_TRAILINGSPACE(n); 1455 copied = ni6_store_addrs(ni6, nni6, ifp, lenlim); 1456 /* XXX: reset mbuf length */ 1457 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + 1458 sizeof(struct icmp6_nodeinfo) + copied; 1459 break; 1460 } 1461 default: 1462 break; /* XXX impossible! */ 1463 } 1464 1465 nni6->ni_type = ICMP6_NI_REPLY; 1466 m_freem(m); 1467 return (n); 1468 1469 bad: 1470 m_freem(m); 1471 if (n) 1472 m_freem(n); 1473 return (NULL); 1474 } 1475 #undef hostnamelen 1476 1477 /* 1478 * make a mbuf with DNS-encoded string. no compression support. 1479 * 1480 * XXX names with less than 2 dots (like "foo" or "foo.section") will be 1481 * treated as truncated name (two \0 at the end). this is a wild guess. 1482 */ 1483 static struct mbuf * 1484 ni6_nametodns(name, namelen, old) 1485 const char *name; 1486 int namelen; 1487 int old; /* return pascal string if non-zero */ 1488 { 1489 struct mbuf *m; 1490 char *cp, *ep; 1491 const char *p, *q; 1492 int i, len, nterm; 1493 1494 if (old) 1495 len = namelen + 1; 1496 else 1497 len = MCLBYTES; 1498 1499 /* because MAXHOSTNAMELEN is usually 256, we use cluster mbuf */ 1500 MGET(m, M_DONTWAIT, MT_DATA); 1501 if (m && len > MLEN) { 1502 MCLGET(m, M_DONTWAIT); 1503 if ((m->m_flags & M_EXT) == 0) 1504 goto fail; 1505 } 1506 if (!m) 1507 goto fail; 1508 m->m_next = NULL; 1509 1510 if (old) { 1511 m->m_len = len; 1512 *mtod(m, char *) = namelen; 1513 bcopy(name, mtod(m, char *) + 1, namelen); 1514 return m; 1515 } else { 1516 m->m_len = 0; 1517 cp = mtod(m, char *); 1518 ep = mtod(m, char *) + M_TRAILINGSPACE(m); 1519 1520 /* if not certain about my name, return empty buffer */ 1521 if (namelen == 0) 1522 return m; 1523 1524 /* 1525 * guess if it looks like shortened hostname, or FQDN. 1526 * shortened hostname needs two trailing "\0". 1527 */ 1528 i = 0; 1529 for (p = name; p < name + namelen; p++) { 1530 if (*p && *p == '.') 1531 i++; 1532 } 1533 if (i < 2) 1534 nterm = 2; 1535 else 1536 nterm = 1; 1537 1538 p = name; 1539 while (cp < ep && p < name + namelen) { 1540 i = 0; 1541 for (q = p; q < name + namelen && *q && *q != '.'; q++) 1542 i++; 1543 /* result does not fit into mbuf */ 1544 if (cp + i + 1 >= ep) 1545 goto fail; 1546 /* 1547 * DNS label length restriction, RFC1035 page 8. 1548 * "i == 0" case is included here to avoid returning 1549 * 0-length label on "foo..bar". 1550 */ 1551 if (i <= 0 || i >= 64) 1552 goto fail; 1553 *cp++ = i; 1554 bcopy(p, cp, i); 1555 cp += i; 1556 p = q; 1557 if (p < name + namelen && *p == '.') 1558 p++; 1559 } 1560 /* termination */ 1561 if (cp + nterm >= ep) 1562 goto fail; 1563 while (nterm-- > 0) 1564 *cp++ = '\0'; 1565 m->m_len = cp - mtod(m, char *); 1566 return m; 1567 } 1568 1569 panic("should not reach here"); 1570 /* NOTREACHED */ 1571 1572 fail: 1573 if (m) 1574 m_freem(m); 1575 return NULL; 1576 } 1577 1578 /* 1579 * check if two DNS-encoded string matches. takes care of truncated 1580 * form (with \0\0 at the end). no compression support. 1581 * XXX upper/lowercase match (see RFC2065) 1582 */ 1583 static int 1584 ni6_dnsmatch(a, alen, b, blen) 1585 const char *a; 1586 int alen; 1587 const char *b; 1588 int blen; 1589 { 1590 const char *a0, *b0; 1591 int l; 1592 1593 /* simplest case - need validation? */ 1594 if (alen == blen && bcmp(a, b, alen) == 0) 1595 return 1; 1596 1597 a0 = a; 1598 b0 = b; 1599 1600 /* termination is mandatory */ 1601 if (alen < 2 || blen < 2) 1602 return 0; 1603 if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0') 1604 return 0; 1605 alen--; 1606 blen--; 1607 1608 while (a - a0 < alen && b - b0 < blen) { 1609 if (a - a0 + 1 > alen || b - b0 + 1 > blen) 1610 return 0; 1611 1612 if ((signed char)a[0] < 0 || (signed char)b[0] < 0) 1613 return 0; 1614 /* we don't support compression yet */ 1615 if (a[0] >= 64 || b[0] >= 64) 1616 return 0; 1617 1618 /* truncated case */ 1619 if (a[0] == 0 && a - a0 == alen - 1) 1620 return 1; 1621 if (b[0] == 0 && b - b0 == blen - 1) 1622 return 1; 1623 if (a[0] == 0 || b[0] == 0) 1624 return 0; 1625 1626 if (a[0] != b[0]) 1627 return 0; 1628 l = a[0]; 1629 if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen) 1630 return 0; 1631 if (bcmp(a + 1, b + 1, l) != 0) 1632 return 0; 1633 1634 a += 1 + l; 1635 b += 1 + l; 1636 } 1637 1638 if (a - a0 == alen && b - b0 == blen) 1639 return 1; 1640 else 1641 return 0; 1642 } 1643 1644 /* 1645 * calculate the number of addresses to be returned in the node info reply. 1646 */ 1647 static int 1648 ni6_addrs(ni6, m, ifpp, subj) 1649 struct icmp6_nodeinfo *ni6; 1650 struct mbuf *m; 1651 struct ifnet **ifpp; 1652 char *subj; 1653 { 1654 struct ifnet *ifp; 1655 struct in6_ifaddr *ifa6; 1656 struct ifaddr *ifa; 1657 struct sockaddr_in6 *subj_ip6 = NULL; /* XXX pedant */ 1658 int addrs = 0, addrsofif, iffound = 0; 1659 int niflags = ni6->ni_flags; 1660 1661 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) { 1662 switch (ni6->ni_code) { 1663 case ICMP6_NI_SUBJ_IPV6: 1664 if (subj == NULL) /* must be impossible... */ 1665 return (0); 1666 subj_ip6 = (struct sockaddr_in6 *)subj; 1667 break; 1668 default: 1669 /* 1670 * XXX: we only support IPv6 subject address for 1671 * this Qtype. 1672 */ 1673 return (0); 1674 } 1675 } 1676 1677 IFNET_RLOCK(); 1678 for (ifp = TAILQ_FIRST(&ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list)) { 1679 addrsofif = 0; 1680 TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) { 1681 if (ifa->ifa_addr->sa_family != AF_INET6) 1682 continue; 1683 ifa6 = (struct in6_ifaddr *)ifa; 1684 1685 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 && 1686 IN6_ARE_ADDR_EQUAL(&subj_ip6->sin6_addr, 1687 &ifa6->ia_addr.sin6_addr)) 1688 iffound = 1; 1689 1690 /* 1691 * IPv4-mapped addresses can only be returned by a 1692 * Node Information proxy, since they represent 1693 * addresses of IPv4-only nodes, which perforce do 1694 * not implement this protocol. 1695 * [icmp-name-lookups-07, Section 5.4] 1696 * So we don't support NI_NODEADDR_FLAG_COMPAT in 1697 * this function at this moment. 1698 */ 1699 1700 /* What do we have to do about ::1? */ 1701 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { 1702 case IPV6_ADDR_SCOPE_LINKLOCAL: 1703 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) 1704 continue; 1705 break; 1706 case IPV6_ADDR_SCOPE_SITELOCAL: 1707 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) 1708 continue; 1709 break; 1710 case IPV6_ADDR_SCOPE_GLOBAL: 1711 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) 1712 continue; 1713 break; 1714 default: 1715 continue; 1716 } 1717 1718 /* 1719 * check if anycast is okay. 1720 * XXX: just experimental. not in the spec. 1721 */ 1722 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && 1723 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) 1724 continue; /* we need only unicast addresses */ 1725 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && 1726 (icmp6_nodeinfo & 4) == 0) { 1727 continue; 1728 } 1729 addrsofif++; /* count the address */ 1730 } 1731 if (iffound) { 1732 *ifpp = ifp; 1733 IFNET_RUNLOCK(); 1734 return (addrsofif); 1735 } 1736 1737 addrs += addrsofif; 1738 } 1739 IFNET_RUNLOCK(); 1740 1741 return (addrs); 1742 } 1743 1744 static int 1745 ni6_store_addrs(ni6, nni6, ifp0, resid) 1746 struct icmp6_nodeinfo *ni6, *nni6; 1747 struct ifnet *ifp0; 1748 int resid; 1749 { 1750 struct ifnet *ifp = ifp0 ? ifp0 : TAILQ_FIRST(&ifnet); 1751 struct in6_ifaddr *ifa6; 1752 struct ifaddr *ifa; 1753 struct ifnet *ifp_dep = NULL; 1754 int copied = 0, allow_deprecated = 0; 1755 u_char *cp = (u_char *)(nni6 + 1); 1756 int niflags = ni6->ni_flags; 1757 u_int32_t ltime; 1758 1759 if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL)) 1760 return (0); /* needless to copy */ 1761 1762 IFNET_RLOCK(); 1763 again: 1764 1765 for (; ifp; ifp = TAILQ_NEXT(ifp, if_list)) { 1766 for (ifa = ifp->if_addrlist.tqh_first; ifa; 1767 ifa = ifa->ifa_list.tqe_next) { 1768 if (ifa->ifa_addr->sa_family != AF_INET6) 1769 continue; 1770 ifa6 = (struct in6_ifaddr *)ifa; 1771 1772 if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 && 1773 allow_deprecated == 0) { 1774 /* 1775 * prefererred address should be put before 1776 * deprecated addresses. 1777 */ 1778 1779 /* record the interface for later search */ 1780 if (ifp_dep == NULL) 1781 ifp_dep = ifp; 1782 1783 continue; 1784 } else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 && 1785 allow_deprecated != 0) 1786 continue; /* we now collect deprecated addrs */ 1787 1788 /* What do we have to do about ::1? */ 1789 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { 1790 case IPV6_ADDR_SCOPE_LINKLOCAL: 1791 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) 1792 continue; 1793 break; 1794 case IPV6_ADDR_SCOPE_SITELOCAL: 1795 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) 1796 continue; 1797 break; 1798 case IPV6_ADDR_SCOPE_GLOBAL: 1799 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) 1800 continue; 1801 break; 1802 default: 1803 continue; 1804 } 1805 1806 /* 1807 * check if anycast is okay. 1808 * XXX: just experimental. not in the spec. 1809 */ 1810 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && 1811 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) 1812 continue; 1813 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && 1814 (icmp6_nodeinfo & 4) == 0) { 1815 continue; 1816 } 1817 1818 /* now we can copy the address */ 1819 if (resid < sizeof(struct in6_addr) + 1820 sizeof(u_int32_t)) { 1821 /* 1822 * We give up much more copy. 1823 * Set the truncate flag and return. 1824 */ 1825 nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE; 1826 IFNET_RUNLOCK(); 1827 return (copied); 1828 } 1829 1830 /* 1831 * Set the TTL of the address. 1832 * The TTL value should be one of the following 1833 * according to the specification: 1834 * 1835 * 1. The remaining lifetime of a DHCP lease on the 1836 * address, or 1837 * 2. The remaining Valid Lifetime of a prefix from 1838 * which the address was derived through Stateless 1839 * Autoconfiguration. 1840 * 1841 * Note that we currently do not support stateful 1842 * address configuration by DHCPv6, so the former 1843 * case can't happen. 1844 */ 1845 if (ifa6->ia6_lifetime.ia6t_expire == 0) 1846 ltime = ND6_INFINITE_LIFETIME; 1847 else { 1848 if (ifa6->ia6_lifetime.ia6t_expire > 1849 time_second) 1850 ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_second); 1851 else 1852 ltime = 0; 1853 } 1854 1855 bcopy(<ime, cp, sizeof(u_int32_t)); 1856 cp += sizeof(u_int32_t); 1857 1858 /* copy the address itself */ 1859 bcopy(&ifa6->ia_addr.sin6_addr, cp, 1860 sizeof(struct in6_addr)); 1861 in6_clearscope((struct in6_addr *)cp); /* XXX */ 1862 cp += sizeof(struct in6_addr); 1863 1864 resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t)); 1865 copied += (sizeof(struct in6_addr) + sizeof(u_int32_t)); 1866 } 1867 if (ifp0) /* we need search only on the specified IF */ 1868 break; 1869 } 1870 1871 if (allow_deprecated == 0 && ifp_dep != NULL) { 1872 ifp = ifp_dep; 1873 allow_deprecated = 1; 1874 1875 goto again; 1876 } 1877 1878 IFNET_RUNLOCK(); 1879 1880 return (copied); 1881 } 1882 1883 /* 1884 * XXX almost dup'ed code with rip6_input. 1885 */ 1886 static int 1887 icmp6_rip6_input(mp, off) 1888 struct mbuf **mp; 1889 int off; 1890 { 1891 struct mbuf *m = *mp; 1892 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1893 struct in6pcb *in6p; 1894 struct in6pcb *last = NULL; 1895 struct sockaddr_in6 fromsa; 1896 struct icmp6_hdr *icmp6; 1897 struct mbuf *opts = NULL; 1898 1899 #ifndef PULLDOWN_TEST 1900 /* this is assumed to be safe. */ 1901 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off); 1902 #else 1903 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6)); 1904 if (icmp6 == NULL) { 1905 /* m is already reclaimed */ 1906 return (IPPROTO_DONE); 1907 } 1908 #endif 1909 1910 bzero(&fromsa, sizeof(fromsa)); 1911 fromsa.sin6_len = sizeof(struct sockaddr_in6); 1912 fromsa.sin6_family = AF_INET6; 1913 /* KAME hack: recover scopeid */ 1914 (void)in6_recoverscope(&fromsa, &ip6->ip6_src, m->m_pkthdr.rcvif); 1915 1916 LIST_FOREACH(in6p, &ripcb, inp_list) { 1917 if ((in6p->inp_vflag & INP_IPV6) == 0) 1918 continue; 1919 if (in6p->in6p_ip6_nxt != IPPROTO_ICMPV6) 1920 continue; 1921 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) && 1922 !IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &ip6->ip6_dst)) 1923 continue; 1924 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr) && 1925 !IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src)) 1926 continue; 1927 if (in6p->in6p_icmp6filt 1928 && ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type, 1929 in6p->in6p_icmp6filt)) 1930 continue; 1931 if (last) { 1932 struct mbuf *n = NULL; 1933 1934 /* 1935 * Recent network drivers tend to allocate a single 1936 * mbuf cluster, rather than to make a couple of 1937 * mbufs without clusters. Also, since the IPv6 code 1938 * path tries to avoid m_pullup(), it is highly 1939 * probable that we still have an mbuf cluster here 1940 * even though the necessary length can be stored in an 1941 * mbuf's internal buffer. 1942 * Meanwhile, the default size of the receive socket 1943 * buffer for raw sockets is not so large. This means 1944 * the possibility of packet loss is relatively higher 1945 * than before. To avoid this scenario, we copy the 1946 * received data to a separate mbuf that does not use 1947 * a cluster, if possible. 1948 * XXX: it is better to copy the data after stripping 1949 * intermediate headers. 1950 */ 1951 if ((m->m_flags & M_EXT) && m->m_next == NULL && 1952 m->m_len <= MHLEN) { 1953 MGET(n, M_DONTWAIT, m->m_type); 1954 if (n != NULL) { 1955 m_dup_pkthdr(n, m, M_NOWAIT); 1956 bcopy(m->m_data, n->m_data, m->m_len); 1957 n->m_len = m->m_len; 1958 } 1959 } 1960 if (n != NULL || 1961 (n = m_copy(m, 0, (int)M_COPYALL)) != NULL) { 1962 if (last->in6p_flags & IN6P_CONTROLOPTS) 1963 ip6_savecontrol(last, n, &opts); 1964 /* strip intermediate headers */ 1965 m_adj(n, off); 1966 if (sbappendaddr(&last->in6p_socket->so_rcv, 1967 (struct sockaddr *)&fromsa, n, opts) 1968 == 0) { 1969 /* should notify about lost packet */ 1970 m_freem(n); 1971 if (opts) { 1972 m_freem(opts); 1973 } 1974 } else 1975 sorwakeup(last->in6p_socket); 1976 opts = NULL; 1977 } 1978 } 1979 last = in6p; 1980 } 1981 if (last) { 1982 if (last->in6p_flags & IN6P_CONTROLOPTS) 1983 ip6_savecontrol(last, m, &opts); 1984 /* strip intermediate headers */ 1985 m_adj(m, off); 1986 1987 /* avoid using mbuf clusters if possible (see above) */ 1988 if ((m->m_flags & M_EXT) && m->m_next == NULL && 1989 m->m_len <= MHLEN) { 1990 struct mbuf *n; 1991 1992 MGET(n, M_DONTWAIT, m->m_type); 1993 if (n != NULL) { 1994 m_dup_pkthdr(n, m, M_NOWAIT); 1995 bcopy(m->m_data, n->m_data, m->m_len); 1996 n->m_len = m->m_len; 1997 1998 m_freem(m); 1999 m = n; 2000 } 2001 } 2002 if (sbappendaddr(&last->in6p_socket->so_rcv, 2003 (struct sockaddr *)&fromsa, m, opts) == 0) { 2004 m_freem(m); 2005 if (opts) 2006 m_freem(opts); 2007 } else 2008 sorwakeup(last->in6p_socket); 2009 } else { 2010 m_freem(m); 2011 ip6stat.ip6s_delivered--; 2012 } 2013 return IPPROTO_DONE; 2014 } 2015 2016 /* 2017 * Reflect the ip6 packet back to the source. 2018 * OFF points to the icmp6 header, counted from the top of the mbuf. 2019 */ 2020 void 2021 icmp6_reflect(m, off) 2022 struct mbuf *m; 2023 size_t off; 2024 { 2025 struct ip6_hdr *ip6; 2026 struct icmp6_hdr *icmp6; 2027 struct in6_ifaddr *ia; 2028 struct in6_addr t, *src = 0; 2029 int plen; 2030 int type, code; 2031 struct ifnet *outif = NULL; 2032 struct sockaddr_in6 sa6_src, sa6_dst; 2033 #ifdef COMPAT_RFC1885 2034 int mtu = IPV6_MMTU; 2035 struct sockaddr_in6 *sin6 = &icmp6_reflect_rt.ro_dst; 2036 #endif 2037 2038 /* too short to reflect */ 2039 if (off < sizeof(struct ip6_hdr)) { 2040 nd6log((LOG_DEBUG, 2041 "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n", 2042 (u_long)off, (u_long)sizeof(struct ip6_hdr), 2043 __FILE__, __LINE__)); 2044 goto bad; 2045 } 2046 2047 /* 2048 * If there are extra headers between IPv6 and ICMPv6, strip 2049 * off that header first. 2050 */ 2051 #ifdef DIAGNOSTIC 2052 if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN) 2053 panic("assumption failed in icmp6_reflect"); 2054 #endif 2055 if (off > sizeof(struct ip6_hdr)) { 2056 size_t l; 2057 struct ip6_hdr nip6; 2058 2059 l = off - sizeof(struct ip6_hdr); 2060 m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6); 2061 m_adj(m, l); 2062 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 2063 if (m->m_len < l) { 2064 if ((m = m_pullup(m, l)) == NULL) 2065 return; 2066 } 2067 bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6)); 2068 } else /* off == sizeof(struct ip6_hdr) */ { 2069 size_t l; 2070 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 2071 if (m->m_len < l) { 2072 if ((m = m_pullup(m, l)) == NULL) 2073 return; 2074 } 2075 } 2076 plen = m->m_pkthdr.len - sizeof(struct ip6_hdr); 2077 ip6 = mtod(m, struct ip6_hdr *); 2078 ip6->ip6_nxt = IPPROTO_ICMPV6; 2079 icmp6 = (struct icmp6_hdr *)(ip6 + 1); 2080 type = icmp6->icmp6_type; /* keep type for statistics */ 2081 code = icmp6->icmp6_code; /* ditto. */ 2082 2083 t = ip6->ip6_dst; 2084 /* 2085 * ip6_input() drops a packet if its src is multicast. 2086 * So, the src is never multicast. 2087 */ 2088 ip6->ip6_dst = ip6->ip6_src; 2089 2090 /* 2091 * XXX: make sure to embed scope zone information, using 2092 * already embedded IDs or the received interface (if any). 2093 * Note that rcvif may be NULL. 2094 * TODO: scoped routing case (XXX). 2095 */ 2096 bzero(&sa6_src, sizeof(sa6_src)); 2097 sa6_src.sin6_family = AF_INET6; 2098 sa6_src.sin6_len = sizeof(sa6_src); 2099 sa6_src.sin6_addr = ip6->ip6_dst; 2100 in6_recoverscope(&sa6_src, &ip6->ip6_dst, m->m_pkthdr.rcvif); 2101 in6_embedscope(&ip6->ip6_dst, &sa6_src, NULL, NULL); 2102 bzero(&sa6_dst, sizeof(sa6_dst)); 2103 sa6_dst.sin6_family = AF_INET6; 2104 sa6_dst.sin6_len = sizeof(sa6_dst); 2105 sa6_dst.sin6_addr = t; 2106 in6_recoverscope(&sa6_dst, &t, m->m_pkthdr.rcvif); 2107 in6_embedscope(&t, &sa6_dst, NULL, NULL); 2108 2109 #ifdef COMPAT_RFC1885 2110 /* 2111 * xxx guess MTU 2112 * RFC 1885 requires that echo reply should be truncated if it 2113 * does not fit in with (return) path MTU, but the description was 2114 * removed in the new spec. 2115 */ 2116 if (icmp6_reflect_rt.ro_rt == 0 || 2117 ! (IN6_ARE_ADDR_EQUAL(&sin6->sin6_addr, &ip6->ip6_dst))) { 2118 if (icmp6_reflect_rt.ro_rt) { 2119 RTFREE(icmp6_reflect_rt.ro_rt); 2120 icmp6_reflect_rt.ro_rt = 0; 2121 } 2122 bzero(sin6, sizeof(*sin6)); 2123 sin6->sin6_family = PF_INET6; 2124 sin6->sin6_len = sizeof(struct sockaddr_in6); 2125 sin6->sin6_addr = ip6->ip6_dst; 2126 2127 rtalloc((struct route *)&icmp6_reflect_rt.ro_rt); 2128 } 2129 2130 if (icmp6_reflect_rt.ro_rt == 0) 2131 goto bad; 2132 2133 if ((icmp6_reflect_rt.ro_rt->rt_flags & RTF_HOST) 2134 && mtu < icmp6_reflect_rt.ro_rt->rt_ifp->if_mtu) 2135 mtu = icmp6_reflect_rt.ro_rt->rt_rmx.rmx_mtu; 2136 2137 if (mtu < m->m_pkthdr.len) { 2138 plen -= (m->m_pkthdr.len - mtu); 2139 m_adj(m, mtu - m->m_pkthdr.len); 2140 } 2141 #endif 2142 /* 2143 * If the incoming packet was addressed directly to us (i.e. unicast), 2144 * use dst as the src for the reply. 2145 * The IN6_IFF_NOTREADY case should be VERY rare, but is possible 2146 * (for example) when we encounter an error while forwarding procedure 2147 * destined to a duplicated address of ours. 2148 */ 2149 for (ia = in6_ifaddr; ia; ia = ia->ia_next) 2150 if (IN6_ARE_ADDR_EQUAL(&t, &ia->ia_addr.sin6_addr) && 2151 (ia->ia6_flags & (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY)) == 0) { 2152 src = &t; 2153 break; 2154 } 2155 if (ia == NULL && IN6_IS_ADDR_LINKLOCAL(&t) && (m->m_flags & M_LOOP)) { 2156 /* 2157 * This is the case if the dst is our link-local address 2158 * and the sender is also ourselves. 2159 */ 2160 src = &t; 2161 } 2162 2163 if (src == 0) { 2164 int e; 2165 struct route_in6 ro; 2166 2167 /* 2168 * This case matches to multicasts, our anycast, or unicasts 2169 * that we do not own. Select a source address based on the 2170 * source address of the erroneous packet. 2171 */ 2172 bzero(&ro, sizeof(ro)); 2173 src = in6_selectsrc(&sa6_src, NULL, NULL, &ro, NULL, &e); 2174 if (ro.ro_rt) 2175 RTFREE(ro.ro_rt); /* XXX: we could use this */ 2176 if (src == NULL) { 2177 nd6log((LOG_DEBUG, 2178 "icmp6_reflect: source can't be determined: " 2179 "dst=%s, error=%d\n", 2180 ip6_sprintf(&sa6_src.sin6_addr), e)); 2181 goto bad; 2182 } 2183 } 2184 2185 ip6->ip6_src = *src; 2186 2187 ip6->ip6_flow = 0; 2188 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2189 ip6->ip6_vfc |= IPV6_VERSION; 2190 ip6->ip6_nxt = IPPROTO_ICMPV6; 2191 if (outif) 2192 ip6->ip6_hlim = ND_IFINFO(outif)->chlim; 2193 else if (m->m_pkthdr.rcvif) { 2194 /* XXX: This may not be the outgoing interface */ 2195 ip6->ip6_hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim; 2196 } else 2197 ip6->ip6_hlim = ip6_defhlim; 2198 2199 icmp6->icmp6_cksum = 0; 2200 icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2201 sizeof(struct ip6_hdr), plen); 2202 2203 /* 2204 * XXX option handling 2205 */ 2206 2207 m->m_flags &= ~(M_BCAST|M_MCAST); 2208 2209 #ifdef COMPAT_RFC1885 2210 ip6_output(m, NULL, &icmp6_reflect_rt, 0, NULL, &outif, NULL); 2211 #else 2212 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2213 #endif 2214 if (outif) 2215 icmp6_ifoutstat_inc(outif, type, code); 2216 2217 return; 2218 2219 bad: 2220 m_freem(m); 2221 return; 2222 } 2223 2224 void 2225 icmp6_fasttimo() 2226 { 2227 2228 mld6_fasttimeo(); 2229 } 2230 2231 static const char * 2232 icmp6_redirect_diag(src6, dst6, tgt6) 2233 struct in6_addr *src6; 2234 struct in6_addr *dst6; 2235 struct in6_addr *tgt6; 2236 { 2237 static char buf[1024]; 2238 snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)", 2239 ip6_sprintf(src6), ip6_sprintf(dst6), ip6_sprintf(tgt6)); 2240 return buf; 2241 } 2242 2243 void 2244 icmp6_redirect_input(m, off) 2245 struct mbuf *m; 2246 int off; 2247 { 2248 struct ifnet *ifp = m->m_pkthdr.rcvif; 2249 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 2250 struct nd_redirect *nd_rd; 2251 int icmp6len = ntohs(ip6->ip6_plen); 2252 char *lladdr = NULL; 2253 int lladdrlen = 0; 2254 u_char *redirhdr = NULL; 2255 int redirhdrlen = 0; 2256 struct rtentry *rt = NULL; 2257 int is_router; 2258 int is_onlink; 2259 struct in6_addr src6 = ip6->ip6_src; 2260 struct in6_addr redtgt6; 2261 struct in6_addr reddst6; 2262 union nd_opts ndopts; 2263 2264 if (!m || !ifp) 2265 return; 2266 2267 /* XXX if we are router, we don't update route by icmp6 redirect */ 2268 if (ip6_forwarding) 2269 goto freeit; 2270 if (!icmp6_rediraccept) 2271 goto freeit; 2272 2273 #ifndef PULLDOWN_TEST 2274 IP6_EXTHDR_CHECK(m, off, icmp6len,); 2275 nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off); 2276 #else 2277 IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len); 2278 if (nd_rd == NULL) { 2279 icmp6stat.icp6s_tooshort++; 2280 return; 2281 } 2282 #endif 2283 redtgt6 = nd_rd->nd_rd_target; 2284 reddst6 = nd_rd->nd_rd_dst; 2285 2286 if (IN6_IS_ADDR_LINKLOCAL(&redtgt6)) 2287 redtgt6.s6_addr16[1] = htons(ifp->if_index); 2288 if (IN6_IS_ADDR_LINKLOCAL(&reddst6)) 2289 reddst6.s6_addr16[1] = htons(ifp->if_index); 2290 2291 /* validation */ 2292 if (!IN6_IS_ADDR_LINKLOCAL(&src6)) { 2293 nd6log((LOG_ERR, 2294 "ICMP6 redirect sent from %s rejected; " 2295 "must be from linklocal\n", 2296 ip6_sprintf(&src6))); 2297 goto bad; 2298 } 2299 if (ip6->ip6_hlim != 255) { 2300 nd6log((LOG_ERR, 2301 "ICMP6 redirect sent from %s rejected; " 2302 "hlim=%d (must be 255)\n", 2303 ip6_sprintf(&src6), ip6->ip6_hlim)); 2304 goto bad; 2305 } 2306 { 2307 /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */ 2308 struct sockaddr_in6 sin6; 2309 struct in6_addr *gw6; 2310 2311 bzero(&sin6, sizeof(sin6)); 2312 sin6.sin6_family = AF_INET6; 2313 sin6.sin6_len = sizeof(struct sockaddr_in6); 2314 bcopy(&reddst6, &sin6.sin6_addr, sizeof(reddst6)); 2315 rt = rtalloc1((struct sockaddr *)&sin6, 0, 0UL); 2316 if (rt) { 2317 if (rt->rt_gateway == NULL || 2318 rt->rt_gateway->sa_family != AF_INET6) { 2319 nd6log((LOG_ERR, 2320 "ICMP6 redirect rejected; no route " 2321 "with inet6 gateway found for redirect dst: %s\n", 2322 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2323 RTFREE_LOCKED(rt); 2324 goto bad; 2325 } 2326 2327 gw6 = &(((struct sockaddr_in6 *)rt->rt_gateway)->sin6_addr); 2328 if (bcmp(&src6, gw6, sizeof(struct in6_addr)) != 0) { 2329 nd6log((LOG_ERR, 2330 "ICMP6 redirect rejected; " 2331 "not equal to gw-for-src=%s (must be same): " 2332 "%s\n", 2333 ip6_sprintf(gw6), 2334 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2335 RTFREE_LOCKED(rt); 2336 goto bad; 2337 } 2338 } else { 2339 nd6log((LOG_ERR, 2340 "ICMP6 redirect rejected; " 2341 "no route found for redirect dst: %s\n", 2342 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2343 goto bad; 2344 } 2345 RTFREE_LOCKED(rt); 2346 rt = NULL; 2347 } 2348 if (IN6_IS_ADDR_MULTICAST(&reddst6)) { 2349 nd6log((LOG_ERR, 2350 "ICMP6 redirect rejected; " 2351 "redirect dst must be unicast: %s\n", 2352 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2353 goto bad; 2354 } 2355 2356 is_router = is_onlink = 0; 2357 if (IN6_IS_ADDR_LINKLOCAL(&redtgt6)) 2358 is_router = 1; /* router case */ 2359 if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0) 2360 is_onlink = 1; /* on-link destination case */ 2361 if (!is_router && !is_onlink) { 2362 nd6log((LOG_ERR, 2363 "ICMP6 redirect rejected; " 2364 "neither router case nor onlink case: %s\n", 2365 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2366 goto bad; 2367 } 2368 /* validation passed */ 2369 2370 icmp6len -= sizeof(*nd_rd); 2371 nd6_option_init(nd_rd + 1, icmp6len, &ndopts); 2372 if (nd6_options(&ndopts) < 0) { 2373 nd6log((LOG_INFO, "icmp6_redirect_input: " 2374 "invalid ND option, rejected: %s\n", 2375 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2376 /* nd6_options have incremented stats */ 2377 goto freeit; 2378 } 2379 2380 if (ndopts.nd_opts_tgt_lladdr) { 2381 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 2382 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 2383 } 2384 2385 if (ndopts.nd_opts_rh) { 2386 redirhdrlen = ndopts.nd_opts_rh->nd_opt_rh_len; 2387 redirhdr = (u_char *)(ndopts.nd_opts_rh + 1); /* xxx */ 2388 } 2389 2390 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 2391 nd6log((LOG_INFO, 2392 "icmp6_redirect_input: lladdrlen mismatch for %s " 2393 "(if %d, icmp6 packet %d): %s\n", 2394 ip6_sprintf(&redtgt6), ifp->if_addrlen, lladdrlen - 2, 2395 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2396 goto bad; 2397 } 2398 2399 /* RFC 2461 8.3 */ 2400 nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT, 2401 is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER); 2402 2403 if (!is_onlink) { /* better router case. perform rtredirect. */ 2404 /* perform rtredirect */ 2405 struct sockaddr_in6 sdst; 2406 struct sockaddr_in6 sgw; 2407 struct sockaddr_in6 ssrc; 2408 2409 bzero(&sdst, sizeof(sdst)); 2410 bzero(&sgw, sizeof(sgw)); 2411 bzero(&ssrc, sizeof(ssrc)); 2412 sdst.sin6_family = sgw.sin6_family = ssrc.sin6_family = AF_INET6; 2413 sdst.sin6_len = sgw.sin6_len = ssrc.sin6_len = 2414 sizeof(struct sockaddr_in6); 2415 bcopy(&redtgt6, &sgw.sin6_addr, sizeof(struct in6_addr)); 2416 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr)); 2417 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr)); 2418 rtredirect((struct sockaddr *)&sdst, (struct sockaddr *)&sgw, 2419 (struct sockaddr *)NULL, RTF_GATEWAY | RTF_HOST, 2420 (struct sockaddr *)&ssrc); 2421 } 2422 /* finally update cached route in each socket via pfctlinput */ 2423 { 2424 struct sockaddr_in6 sdst; 2425 2426 bzero(&sdst, sizeof(sdst)); 2427 sdst.sin6_family = AF_INET6; 2428 sdst.sin6_len = sizeof(struct sockaddr_in6); 2429 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr)); 2430 pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst); 2431 #if defined(IPSEC) || defined(FAST_IPSEC) 2432 key_sa_routechange((struct sockaddr *)&sdst); 2433 #endif 2434 } 2435 2436 freeit: 2437 m_freem(m); 2438 return; 2439 2440 bad: 2441 icmp6stat.icp6s_badredirect++; 2442 m_freem(m); 2443 } 2444 2445 void 2446 icmp6_redirect_output(m0, rt) 2447 struct mbuf *m0; 2448 struct rtentry *rt; 2449 { 2450 struct ifnet *ifp; /* my outgoing interface */ 2451 struct in6_addr *ifp_ll6; 2452 struct in6_addr *router_ll6; 2453 struct ip6_hdr *sip6; /* m0 as struct ip6_hdr */ 2454 struct mbuf *m = NULL; /* newly allocated one */ 2455 struct ip6_hdr *ip6; /* m as struct ip6_hdr */ 2456 struct nd_redirect *nd_rd; 2457 size_t maxlen; 2458 u_char *p; 2459 struct ifnet *outif = NULL; 2460 struct sockaddr_in6 src_sa; 2461 2462 icmp6_errcount(&icmp6stat.icp6s_outerrhist, ND_REDIRECT, 0); 2463 2464 /* if we are not router, we don't send icmp6 redirect */ 2465 if (!ip6_forwarding || ip6_accept_rtadv) 2466 goto fail; 2467 2468 /* sanity check */ 2469 if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp)) 2470 goto fail; 2471 2472 /* 2473 * Address check: 2474 * the source address must identify a neighbor, and 2475 * the destination address must not be a multicast address 2476 * [RFC 2461, sec 8.2] 2477 */ 2478 sip6 = mtod(m0, struct ip6_hdr *); 2479 bzero(&src_sa, sizeof(src_sa)); 2480 src_sa.sin6_family = AF_INET6; 2481 src_sa.sin6_len = sizeof(src_sa); 2482 src_sa.sin6_addr = sip6->ip6_src; 2483 /* we don't currently use sin6_scope_id, but eventually use it */ 2484 if (in6_addr2zoneid(ifp, &sip6->ip6_src, &src_sa.sin6_scope_id)) 2485 goto fail; 2486 if (nd6_is_addr_neighbor(&src_sa, ifp) == 0) 2487 goto fail; 2488 if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst)) 2489 goto fail; /* what should we do here? */ 2490 2491 /* rate limit */ 2492 if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0)) 2493 goto fail; 2494 2495 /* 2496 * Since we are going to append up to 1280 bytes (= IPV6_MMTU), 2497 * we almost always ask for an mbuf cluster for simplicity. 2498 * (MHLEN < IPV6_MMTU is almost always true) 2499 */ 2500 #if IPV6_MMTU >= MCLBYTES 2501 # error assumption failed about IPV6_MMTU and MCLBYTES 2502 #endif 2503 MGETHDR(m, M_DONTWAIT, MT_HEADER); 2504 if (m && IPV6_MMTU >= MHLEN) 2505 MCLGET(m, M_DONTWAIT); 2506 if (!m) 2507 goto fail; 2508 m->m_pkthdr.rcvif = NULL; 2509 m->m_len = 0; 2510 maxlen = M_TRAILINGSPACE(m); 2511 maxlen = min(IPV6_MMTU, maxlen); 2512 /* just for safety */ 2513 if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) + 2514 ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) { 2515 goto fail; 2516 } 2517 2518 { 2519 /* get ip6 linklocal address for ifp(my outgoing interface). */ 2520 struct in6_ifaddr *ia; 2521 if ((ia = in6ifa_ifpforlinklocal(ifp, 2522 IN6_IFF_NOTREADY| 2523 IN6_IFF_ANYCAST)) == NULL) 2524 goto fail; 2525 ifp_ll6 = &ia->ia_addr.sin6_addr; 2526 } 2527 2528 /* get ip6 linklocal address for the router. */ 2529 if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) { 2530 struct sockaddr_in6 *sin6; 2531 sin6 = (struct sockaddr_in6 *)rt->rt_gateway; 2532 router_ll6 = &sin6->sin6_addr; 2533 if (!IN6_IS_ADDR_LINKLOCAL(router_ll6)) 2534 router_ll6 = (struct in6_addr *)NULL; 2535 } else 2536 router_ll6 = (struct in6_addr *)NULL; 2537 2538 /* ip6 */ 2539 ip6 = mtod(m, struct ip6_hdr *); 2540 ip6->ip6_flow = 0; 2541 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2542 ip6->ip6_vfc |= IPV6_VERSION; 2543 /* ip6->ip6_plen will be set later */ 2544 ip6->ip6_nxt = IPPROTO_ICMPV6; 2545 ip6->ip6_hlim = 255; 2546 /* ip6->ip6_src must be linklocal addr for my outgoing if. */ 2547 bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr)); 2548 bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr)); 2549 2550 /* ND Redirect */ 2551 nd_rd = (struct nd_redirect *)(ip6 + 1); 2552 nd_rd->nd_rd_type = ND_REDIRECT; 2553 nd_rd->nd_rd_code = 0; 2554 nd_rd->nd_rd_reserved = 0; 2555 if (rt->rt_flags & RTF_GATEWAY) { 2556 /* 2557 * nd_rd->nd_rd_target must be a link-local address in 2558 * better router cases. 2559 */ 2560 if (!router_ll6) 2561 goto fail; 2562 bcopy(router_ll6, &nd_rd->nd_rd_target, 2563 sizeof(nd_rd->nd_rd_target)); 2564 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2565 sizeof(nd_rd->nd_rd_dst)); 2566 } else { 2567 /* make sure redtgt == reddst */ 2568 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target, 2569 sizeof(nd_rd->nd_rd_target)); 2570 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2571 sizeof(nd_rd->nd_rd_dst)); 2572 } 2573 2574 p = (u_char *)(nd_rd + 1); 2575 2576 if (!router_ll6) 2577 goto nolladdropt; 2578 2579 { 2580 /* target lladdr option */ 2581 struct rtentry *rt_router = NULL; 2582 int len; 2583 struct sockaddr_dl *sdl; 2584 struct nd_opt_hdr *nd_opt; 2585 char *lladdr; 2586 2587 rt_router = nd6_lookup(router_ll6, 0, ifp); 2588 if (!rt_router) 2589 goto nolladdropt; 2590 len = sizeof(*nd_opt) + ifp->if_addrlen; 2591 len = (len + 7) & ~7; /* round by 8 */ 2592 /* safety check */ 2593 if (len + (p - (u_char *)ip6) > maxlen) 2594 goto nolladdropt; 2595 if (!(rt_router->rt_flags & RTF_GATEWAY) && 2596 (rt_router->rt_flags & RTF_LLINFO) && 2597 (rt_router->rt_gateway->sa_family == AF_LINK) && 2598 (sdl = (struct sockaddr_dl *)rt_router->rt_gateway) && 2599 sdl->sdl_alen) { 2600 nd_opt = (struct nd_opt_hdr *)p; 2601 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 2602 nd_opt->nd_opt_len = len >> 3; 2603 lladdr = (char *)(nd_opt + 1); 2604 bcopy(LLADDR(sdl), lladdr, ifp->if_addrlen); 2605 p += len; 2606 } 2607 } 2608 nolladdropt:; 2609 2610 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2611 2612 /* just to be safe */ 2613 #ifdef M_DECRYPTED /*not openbsd*/ 2614 if (m0->m_flags & M_DECRYPTED) 2615 goto noredhdropt; 2616 #endif 2617 if (p - (u_char *)ip6 > maxlen) 2618 goto noredhdropt; 2619 2620 { 2621 /* redirected header option */ 2622 int len; 2623 struct nd_opt_rd_hdr *nd_opt_rh; 2624 2625 /* 2626 * compute the maximum size for icmp6 redirect header option. 2627 * XXX room for auth header? 2628 */ 2629 len = maxlen - (p - (u_char *)ip6); 2630 len &= ~7; 2631 2632 /* This is just for simplicity. */ 2633 if (m0->m_pkthdr.len != m0->m_len) { 2634 if (m0->m_next) { 2635 m_freem(m0->m_next); 2636 m0->m_next = NULL; 2637 } 2638 m0->m_pkthdr.len = m0->m_len; 2639 } 2640 2641 /* 2642 * Redirected header option spec (RFC2461 4.6.3) talks nothing 2643 * about padding/truncate rule for the original IP packet. 2644 * From the discussion on IPv6imp in Feb 1999, 2645 * the consensus was: 2646 * - "attach as much as possible" is the goal 2647 * - pad if not aligned (original size can be guessed by 2648 * original ip6 header) 2649 * Following code adds the padding if it is simple enough, 2650 * and truncates if not. 2651 */ 2652 if (m0->m_next || m0->m_pkthdr.len != m0->m_len) 2653 panic("assumption failed in %s:%d", __FILE__, 2654 __LINE__); 2655 2656 if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) { 2657 /* not enough room, truncate */ 2658 m0->m_pkthdr.len = m0->m_len = len - 2659 sizeof(*nd_opt_rh); 2660 } else { 2661 /* enough room, pad or truncate */ 2662 size_t extra; 2663 2664 extra = m0->m_pkthdr.len % 8; 2665 if (extra) { 2666 /* pad if easy enough, truncate if not */ 2667 if (8 - extra <= M_TRAILINGSPACE(m0)) { 2668 /* pad */ 2669 m0->m_len += (8 - extra); 2670 m0->m_pkthdr.len += (8 - extra); 2671 } else { 2672 /* truncate */ 2673 m0->m_pkthdr.len -= extra; 2674 m0->m_len -= extra; 2675 } 2676 } 2677 len = m0->m_pkthdr.len + sizeof(*nd_opt_rh); 2678 m0->m_pkthdr.len = m0->m_len = len - 2679 sizeof(*nd_opt_rh); 2680 } 2681 2682 nd_opt_rh = (struct nd_opt_rd_hdr *)p; 2683 bzero(nd_opt_rh, sizeof(*nd_opt_rh)); 2684 nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER; 2685 nd_opt_rh->nd_opt_rh_len = len >> 3; 2686 p += sizeof(*nd_opt_rh); 2687 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2688 2689 /* connect m0 to m */ 2690 m_tag_delete_chain(m0, NULL); 2691 m0->m_flags &= ~M_PKTHDR; 2692 m->m_next = m0; 2693 m->m_pkthdr.len = m->m_len + m0->m_len; 2694 m0 = NULL; 2695 } 2696 noredhdropt:; 2697 if (m0) { 2698 m_freem(m0); 2699 m0 = NULL; 2700 } 2701 2702 /* XXX: clear embedded link IDs in the inner header */ 2703 in6_clearscope(&sip6->ip6_src); 2704 in6_clearscope(&sip6->ip6_dst); 2705 in6_clearscope(&nd_rd->nd_rd_target); 2706 in6_clearscope(&nd_rd->nd_rd_dst); 2707 2708 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr)); 2709 2710 nd_rd->nd_rd_cksum = 0; 2711 nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2712 sizeof(*ip6), ntohs(ip6->ip6_plen)); 2713 2714 /* send the packet to outside... */ 2715 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2716 if (outif) { 2717 icmp6_ifstat_inc(outif, ifs6_out_msg); 2718 icmp6_ifstat_inc(outif, ifs6_out_redirect); 2719 } 2720 icmp6stat.icp6s_outhist[ND_REDIRECT]++; 2721 2722 return; 2723 2724 fail: 2725 if (m) 2726 m_freem(m); 2727 if (m0) 2728 m_freem(m0); 2729 } 2730 2731 /* 2732 * ICMPv6 socket option processing. 2733 */ 2734 int 2735 icmp6_ctloutput(so, sopt) 2736 struct socket *so; 2737 struct sockopt *sopt; 2738 { 2739 int error = 0; 2740 int optlen; 2741 struct inpcb *inp = sotoinpcb(so); 2742 int level, op, optname; 2743 2744 if (sopt) { 2745 level = sopt->sopt_level; 2746 op = sopt->sopt_dir; 2747 optname = sopt->sopt_name; 2748 optlen = sopt->sopt_valsize; 2749 } else 2750 level = op = optname = optlen = 0; 2751 2752 if (level != IPPROTO_ICMPV6) { 2753 return EINVAL; 2754 } 2755 2756 switch (op) { 2757 case PRCO_SETOPT: 2758 switch (optname) { 2759 case ICMP6_FILTER: 2760 { 2761 struct icmp6_filter *p; 2762 2763 if (optlen != sizeof(*p)) { 2764 error = EMSGSIZE; 2765 break; 2766 } 2767 if (inp->in6p_icmp6filt == NULL) { 2768 error = EINVAL; 2769 break; 2770 } 2771 error = sooptcopyin(sopt, inp->in6p_icmp6filt, optlen, 2772 optlen); 2773 break; 2774 } 2775 2776 default: 2777 error = ENOPROTOOPT; 2778 break; 2779 } 2780 break; 2781 2782 case PRCO_GETOPT: 2783 switch (optname) { 2784 case ICMP6_FILTER: 2785 { 2786 if (inp->in6p_icmp6filt == NULL) { 2787 error = EINVAL; 2788 break; 2789 } 2790 error = sooptcopyout(sopt, inp->in6p_icmp6filt, 2791 sizeof(struct icmp6_filter)); 2792 break; 2793 } 2794 2795 default: 2796 error = ENOPROTOOPT; 2797 break; 2798 } 2799 break; 2800 } 2801 2802 return (error); 2803 } 2804 2805 /* 2806 * Perform rate limit check. 2807 * Returns 0 if it is okay to send the icmp6 packet. 2808 * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate 2809 * limitation. 2810 * 2811 * XXX per-destination/type check necessary? 2812 */ 2813 static int 2814 icmp6_ratelimit(dst, type, code) 2815 const struct in6_addr *dst; /* not used at this moment */ 2816 const int type; /* not used at this moment */ 2817 const int code; /* not used at this moment */ 2818 { 2819 int ret; 2820 2821 ret = 0; /* okay to send */ 2822 2823 /* PPS limit */ 2824 if (!ppsratecheck(&icmp6errppslim_last, &icmp6errpps_count, 2825 icmp6errppslim)) { 2826 /* The packet is subject to rate limit */ 2827 ret++; 2828 } 2829 2830 return ret; 2831 } 2832