1 /*- 2 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the project nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * $KAME: icmp6.c,v 1.211 2001/04/04 05:56:20 itojun Exp $ 30 */ 31 32 /*- 33 * Copyright (c) 1982, 1986, 1988, 1993 34 * The Regents of the University of California. All rights reserved. 35 * 36 * Redistribution and use in source and binary forms, with or without 37 * modification, are permitted provided that the following conditions 38 * are met: 39 * 1. Redistributions of source code must retain the above copyright 40 * notice, this list of conditions and the following disclaimer. 41 * 2. Redistributions in binary form must reproduce the above copyright 42 * notice, this list of conditions and the following disclaimer in the 43 * documentation and/or other materials provided with the distribution. 44 * 4. Neither the name of the University nor the names of its contributors 45 * may be used to endorse or promote products derived from this software 46 * without specific prior written permission. 47 * 48 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 49 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 50 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 51 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 52 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 53 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 54 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 55 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 56 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 57 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 58 * SUCH DAMAGE. 59 * 60 * @(#)ip_icmp.c 8.2 (Berkeley) 1/4/94 61 */ 62 63 #include <sys/cdefs.h> 64 __FBSDID("$FreeBSD$"); 65 66 #include "opt_inet.h" 67 #include "opt_inet6.h" 68 #include "opt_ipsec.h" 69 70 #include <sys/param.h> 71 #include <sys/domain.h> 72 #include <sys/kernel.h> 73 #include <sys/lock.h> 74 #include <sys/malloc.h> 75 #include <sys/mbuf.h> 76 #include <sys/protosw.h> 77 #include <sys/signalvar.h> 78 #include <sys/socket.h> 79 #include <sys/socketvar.h> 80 #include <sys/sx.h> 81 #include <sys/syslog.h> 82 #include <sys/systm.h> 83 #include <sys/time.h> 84 85 #include <net/if.h> 86 #include <net/if_dl.h> 87 #include <net/if_types.h> 88 #include <net/route.h> 89 90 #include <netinet/in.h> 91 #include <netinet/in_pcb.h> 92 #include <netinet/in_var.h> 93 #include <netinet/ip6.h> 94 #include <netinet/icmp6.h> 95 #include <netinet/tcp_var.h> 96 #include <netinet6/in6_ifattach.h> 97 #include <netinet6/in6_pcb.h> 98 #include <netinet6/ip6protosw.h> 99 #include <netinet6/ip6_var.h> 100 #include <netinet6/scope6_var.h> 101 #include <netinet6/mld6_var.h> 102 #include <netinet6/nd6.h> 103 104 #ifdef IPSEC 105 #include <netipsec/ipsec.h> 106 #include <netipsec/key.h> 107 #endif 108 109 extern struct domain inet6domain; 110 111 struct icmp6stat icmp6stat; 112 113 extern struct inpcbinfo ripcbinfo; 114 extern struct inpcbhead ripcb; 115 extern int icmp6errppslim; 116 static int icmp6errpps_count = 0; 117 static struct timeval icmp6errppslim_last; 118 extern int icmp6_nodeinfo; 119 120 static void icmp6_errcount(struct icmp6errstat *, int, int); 121 static int icmp6_rip6_input(struct mbuf **, int); 122 static int icmp6_ratelimit(const struct in6_addr *, const int, const int); 123 static const char *icmp6_redirect_diag __P((struct in6_addr *, 124 struct in6_addr *, struct in6_addr *)); 125 static struct mbuf *ni6_input(struct mbuf *, int); 126 static struct mbuf *ni6_nametodns(const char *, int, int); 127 static int ni6_dnsmatch(const char *, int, const char *, int); 128 static int ni6_addrs __P((struct icmp6_nodeinfo *, struct mbuf *, 129 struct ifnet **, struct in6_addr *)); 130 static int ni6_store_addrs __P((struct icmp6_nodeinfo *, struct icmp6_nodeinfo *, 131 struct ifnet *, int)); 132 static int icmp6_notify_error(struct mbuf **, int, int, int); 133 134 135 void 136 icmp6_init(void) 137 { 138 139 mld6_init(); 140 } 141 142 static void 143 icmp6_errcount(struct icmp6errstat *stat, int type, int code) 144 { 145 switch (type) { 146 case ICMP6_DST_UNREACH: 147 switch (code) { 148 case ICMP6_DST_UNREACH_NOROUTE: 149 stat->icp6errs_dst_unreach_noroute++; 150 return; 151 case ICMP6_DST_UNREACH_ADMIN: 152 stat->icp6errs_dst_unreach_admin++; 153 return; 154 case ICMP6_DST_UNREACH_BEYONDSCOPE: 155 stat->icp6errs_dst_unreach_beyondscope++; 156 return; 157 case ICMP6_DST_UNREACH_ADDR: 158 stat->icp6errs_dst_unreach_addr++; 159 return; 160 case ICMP6_DST_UNREACH_NOPORT: 161 stat->icp6errs_dst_unreach_noport++; 162 return; 163 } 164 break; 165 case ICMP6_PACKET_TOO_BIG: 166 stat->icp6errs_packet_too_big++; 167 return; 168 case ICMP6_TIME_EXCEEDED: 169 switch (code) { 170 case ICMP6_TIME_EXCEED_TRANSIT: 171 stat->icp6errs_time_exceed_transit++; 172 return; 173 case ICMP6_TIME_EXCEED_REASSEMBLY: 174 stat->icp6errs_time_exceed_reassembly++; 175 return; 176 } 177 break; 178 case ICMP6_PARAM_PROB: 179 switch (code) { 180 case ICMP6_PARAMPROB_HEADER: 181 stat->icp6errs_paramprob_header++; 182 return; 183 case ICMP6_PARAMPROB_NEXTHEADER: 184 stat->icp6errs_paramprob_nextheader++; 185 return; 186 case ICMP6_PARAMPROB_OPTION: 187 stat->icp6errs_paramprob_option++; 188 return; 189 } 190 break; 191 case ND_REDIRECT: 192 stat->icp6errs_redirect++; 193 return; 194 } 195 stat->icp6errs_unknown++; 196 } 197 198 /* 199 * A wrapper function for icmp6_error() necessary when the erroneous packet 200 * may not contain enough scope zone information. 201 */ 202 void 203 icmp6_error2(struct mbuf *m, int type, int code, int param, 204 struct ifnet *ifp) 205 { 206 struct ip6_hdr *ip6; 207 208 if (ifp == NULL) 209 return; 210 211 #ifndef PULLDOWN_TEST 212 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), ); 213 #else 214 if (m->m_len < sizeof(struct ip6_hdr)) { 215 m = m_pullup(m, sizeof(struct ip6_hdr)); 216 if (m == NULL) 217 return; 218 } 219 #endif 220 221 ip6 = mtod(m, struct ip6_hdr *); 222 223 if (in6_setscope(&ip6->ip6_src, ifp, NULL) != 0) 224 return; 225 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0) 226 return; 227 228 icmp6_error(m, type, code, param); 229 } 230 231 /* 232 * Generate an error packet of type error in response to bad IP6 packet. 233 */ 234 void 235 icmp6_error(struct mbuf *m, int type, int code, int param) 236 { 237 struct ip6_hdr *oip6, *nip6; 238 struct icmp6_hdr *icmp6; 239 u_int preplen; 240 int off; 241 int nxt; 242 243 icmp6stat.icp6s_error++; 244 245 /* count per-type-code statistics */ 246 icmp6_errcount(&icmp6stat.icp6s_outerrhist, type, code); 247 248 #ifdef M_DECRYPTED /*not openbsd*/ 249 if (m->m_flags & M_DECRYPTED) { 250 icmp6stat.icp6s_canterror++; 251 goto freeit; 252 } 253 #endif 254 255 #ifndef PULLDOWN_TEST 256 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), ); 257 #else 258 if (m->m_len < sizeof(struct ip6_hdr)) { 259 m = m_pullup(m, sizeof(struct ip6_hdr)); 260 if (m == NULL) 261 return; 262 } 263 #endif 264 oip6 = mtod(m, struct ip6_hdr *); 265 266 /* 267 * If the destination address of the erroneous packet is a multicast 268 * address, or the packet was sent using link-layer multicast, 269 * we should basically suppress sending an error (RFC 2463, Section 270 * 2.4). 271 * We have two exceptions (the item e.2 in that section): 272 * - the Pakcet Too Big message can be sent for path MTU discovery. 273 * - the Parameter Problem Message that can be allowed an icmp6 error 274 * in the option type field. This check has been done in 275 * ip6_unknown_opt(), so we can just check the type and code. 276 */ 277 if ((m->m_flags & (M_BCAST|M_MCAST) || 278 IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) && 279 (type != ICMP6_PACKET_TOO_BIG && 280 (type != ICMP6_PARAM_PROB || 281 code != ICMP6_PARAMPROB_OPTION))) 282 goto freeit; 283 284 /* 285 * RFC 2463, 2.4 (e.5): source address check. 286 * XXX: the case of anycast source? 287 */ 288 if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) || 289 IN6_IS_ADDR_MULTICAST(&oip6->ip6_src)) 290 goto freeit; 291 292 /* 293 * If we are about to send ICMPv6 against ICMPv6 error/redirect, 294 * don't do it. 295 */ 296 nxt = -1; 297 off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt); 298 if (off >= 0 && nxt == IPPROTO_ICMPV6) { 299 struct icmp6_hdr *icp; 300 301 #ifndef PULLDOWN_TEST 302 IP6_EXTHDR_CHECK(m, 0, off + sizeof(struct icmp6_hdr), ); 303 icp = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 304 #else 305 IP6_EXTHDR_GET(icp, struct icmp6_hdr *, m, off, 306 sizeof(*icp)); 307 if (icp == NULL) { 308 icmp6stat.icp6s_tooshort++; 309 return; 310 } 311 #endif 312 if (icp->icmp6_type < ICMP6_ECHO_REQUEST || 313 icp->icmp6_type == ND_REDIRECT) { 314 /* 315 * ICMPv6 error 316 * Special case: for redirect (which is 317 * informational) we must not send icmp6 error. 318 */ 319 icmp6stat.icp6s_canterror++; 320 goto freeit; 321 } else { 322 /* ICMPv6 informational - send the error */ 323 } 324 } else { 325 /* non-ICMPv6 - send the error */ 326 } 327 328 oip6 = mtod(m, struct ip6_hdr *); /* adjust pointer */ 329 330 /* Finally, do rate limitation check. */ 331 if (icmp6_ratelimit(&oip6->ip6_src, type, code)) { 332 icmp6stat.icp6s_toofreq++; 333 goto freeit; 334 } 335 336 /* 337 * OK, ICMP6 can be generated. 338 */ 339 340 if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN) 341 m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len); 342 343 preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 344 M_PREPEND(m, preplen, M_DONTWAIT); 345 if (m && m->m_len < preplen) 346 m = m_pullup(m, preplen); 347 if (m == NULL) { 348 nd6log((LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__)); 349 return; 350 } 351 352 nip6 = mtod(m, struct ip6_hdr *); 353 nip6->ip6_src = oip6->ip6_src; 354 nip6->ip6_dst = oip6->ip6_dst; 355 356 in6_clearscope(&oip6->ip6_src); 357 in6_clearscope(&oip6->ip6_dst); 358 359 icmp6 = (struct icmp6_hdr *)(nip6 + 1); 360 icmp6->icmp6_type = type; 361 icmp6->icmp6_code = code; 362 icmp6->icmp6_pptr = htonl((u_int32_t)param); 363 364 /* 365 * icmp6_reflect() is designed to be in the input path. 366 * icmp6_error() can be called from both input and output path, 367 * and if we are in output path rcvif could contain bogus value. 368 * clear m->m_pkthdr.rcvif for safety, we should have enough scope 369 * information in ip header (nip6). 370 */ 371 m->m_pkthdr.rcvif = NULL; 372 373 icmp6stat.icp6s_outhist[type]++; 374 icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */ 375 376 return; 377 378 freeit: 379 /* 380 * If we can't tell whether or not we can generate ICMP6, free it. 381 */ 382 m_freem(m); 383 } 384 385 /* 386 * Process a received ICMP6 message. 387 */ 388 int 389 icmp6_input(struct mbuf **mp, int *offp, int proto) 390 { 391 struct mbuf *m = *mp, *n; 392 struct ip6_hdr *ip6, *nip6; 393 struct icmp6_hdr *icmp6, *nicmp6; 394 int off = *offp; 395 int icmp6len = m->m_pkthdr.len - *offp; 396 int code, sum, noff; 397 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 398 399 #ifndef PULLDOWN_TEST 400 IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_hdr), IPPROTO_DONE); 401 /* m might change if M_LOOP. So, call mtod after this */ 402 #endif 403 404 /* 405 * Locate icmp6 structure in mbuf, and check 406 * that not corrupted and of at least minimum length 407 */ 408 409 ip6 = mtod(m, struct ip6_hdr *); 410 if (icmp6len < sizeof(struct icmp6_hdr)) { 411 icmp6stat.icp6s_tooshort++; 412 goto freeit; 413 } 414 415 /* 416 * calculate the checksum 417 */ 418 #ifndef PULLDOWN_TEST 419 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off); 420 #else 421 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6)); 422 if (icmp6 == NULL) { 423 icmp6stat.icp6s_tooshort++; 424 return IPPROTO_DONE; 425 } 426 #endif 427 code = icmp6->icmp6_code; 428 429 if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) { 430 nd6log((LOG_ERR, 431 "ICMP6 checksum error(%d|%x) %s\n", 432 icmp6->icmp6_type, sum, 433 ip6_sprintf(ip6bufs, &ip6->ip6_src))); 434 icmp6stat.icp6s_checksum++; 435 goto freeit; 436 } 437 438 if (faithprefix_p != NULL && (*faithprefix_p)(&ip6->ip6_dst)) { 439 /* 440 * Deliver very specific ICMP6 type only. 441 * This is important to deliver TOOBIG. Otherwise PMTUD 442 * will not work. 443 */ 444 switch (icmp6->icmp6_type) { 445 case ICMP6_DST_UNREACH: 446 case ICMP6_PACKET_TOO_BIG: 447 case ICMP6_TIME_EXCEEDED: 448 break; 449 default: 450 goto freeit; 451 } 452 } 453 454 icmp6stat.icp6s_inhist[icmp6->icmp6_type]++; 455 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_msg); 456 if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK) 457 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_error); 458 459 switch (icmp6->icmp6_type) { 460 case ICMP6_DST_UNREACH: 461 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_dstunreach); 462 switch (code) { 463 case ICMP6_DST_UNREACH_NOROUTE: 464 code = PRC_UNREACH_NET; 465 break; 466 case ICMP6_DST_UNREACH_ADMIN: 467 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_adminprohib); 468 code = PRC_UNREACH_PROTOCOL; /* is this a good code? */ 469 break; 470 case ICMP6_DST_UNREACH_ADDR: 471 code = PRC_HOSTDEAD; 472 break; 473 case ICMP6_DST_UNREACH_BEYONDSCOPE: 474 /* I mean "source address was incorrect." */ 475 code = PRC_PARAMPROB; 476 break; 477 case ICMP6_DST_UNREACH_NOPORT: 478 code = PRC_UNREACH_PORT; 479 break; 480 default: 481 goto badcode; 482 } 483 goto deliver; 484 break; 485 486 case ICMP6_PACKET_TOO_BIG: 487 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_pkttoobig); 488 489 /* validation is made in icmp6_mtudisc_update */ 490 491 code = PRC_MSGSIZE; 492 493 /* 494 * Updating the path MTU will be done after examining 495 * intermediate extension headers. 496 */ 497 goto deliver; 498 break; 499 500 case ICMP6_TIME_EXCEEDED: 501 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_timeexceed); 502 switch (code) { 503 case ICMP6_TIME_EXCEED_TRANSIT: 504 code = PRC_TIMXCEED_INTRANS; 505 break; 506 case ICMP6_TIME_EXCEED_REASSEMBLY: 507 code = PRC_TIMXCEED_REASS; 508 break; 509 default: 510 goto badcode; 511 } 512 goto deliver; 513 break; 514 515 case ICMP6_PARAM_PROB: 516 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_paramprob); 517 switch (code) { 518 case ICMP6_PARAMPROB_NEXTHEADER: 519 code = PRC_UNREACH_PROTOCOL; 520 break; 521 case ICMP6_PARAMPROB_HEADER: 522 case ICMP6_PARAMPROB_OPTION: 523 code = PRC_PARAMPROB; 524 break; 525 default: 526 goto badcode; 527 } 528 goto deliver; 529 break; 530 531 case ICMP6_ECHO_REQUEST: 532 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_echo); 533 if (code != 0) 534 goto badcode; 535 if ((n = m_copy(m, 0, M_COPYALL)) == NULL) { 536 /* Give up remote */ 537 break; 538 } 539 if ((n->m_flags & M_EXT) != 0 540 || n->m_len < off + sizeof(struct icmp6_hdr)) { 541 struct mbuf *n0 = n; 542 const int maxlen = sizeof(*nip6) + sizeof(*nicmp6); 543 int n0len; 544 545 MGETHDR(n, M_DONTWAIT, n0->m_type); 546 n0len = n0->m_pkthdr.len; /* save for use below */ 547 if (n) 548 M_MOVE_PKTHDR(n, n0); 549 if (n && maxlen >= MHLEN) { 550 MCLGET(n, M_DONTWAIT); 551 if ((n->m_flags & M_EXT) == 0) { 552 m_free(n); 553 n = NULL; 554 } 555 } 556 if (n == NULL) { 557 /* Give up remote */ 558 m_freem(n0); 559 break; 560 } 561 /* 562 * Copy IPv6 and ICMPv6 only. 563 */ 564 nip6 = mtod(n, struct ip6_hdr *); 565 bcopy(ip6, nip6, sizeof(struct ip6_hdr)); 566 nicmp6 = (struct icmp6_hdr *)(nip6 + 1); 567 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr)); 568 noff = sizeof(struct ip6_hdr); 569 /* new mbuf contains only ipv6+icmpv6 headers */ 570 n->m_len = noff + sizeof(struct icmp6_hdr); 571 /* 572 * Adjust mbuf. ip6_plen will be adjusted in 573 * ip6_output(). 574 */ 575 m_adj(n0, off + sizeof(struct icmp6_hdr)); 576 /* recalculate complete packet size */ 577 n->m_pkthdr.len = n0len + (noff - off); 578 n->m_next = n0; 579 } else { 580 nip6 = mtod(n, struct ip6_hdr *); 581 IP6_EXTHDR_GET(nicmp6, struct icmp6_hdr *, n, off, 582 sizeof(*nicmp6)); 583 noff = off; 584 } 585 nicmp6->icmp6_type = ICMP6_ECHO_REPLY; 586 nicmp6->icmp6_code = 0; 587 if (n) { 588 icmp6stat.icp6s_reflect++; 589 icmp6stat.icp6s_outhist[ICMP6_ECHO_REPLY]++; 590 icmp6_reflect(n, noff); 591 } 592 break; 593 594 case ICMP6_ECHO_REPLY: 595 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_echoreply); 596 if (code != 0) 597 goto badcode; 598 break; 599 600 case MLD_LISTENER_QUERY: 601 case MLD_LISTENER_REPORT: 602 if (icmp6len < sizeof(struct mld_hdr)) 603 goto badlen; 604 if (icmp6->icmp6_type == MLD_LISTENER_QUERY) /* XXX: ugly... */ 605 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mldquery); 606 else 607 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mldreport); 608 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 609 /* give up local */ 610 mld6_input(m, off); 611 m = NULL; 612 goto freeit; 613 } 614 mld6_input(n, off); 615 /* m stays. */ 616 break; 617 618 case MLD_LISTENER_DONE: 619 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mlddone); 620 if (icmp6len < sizeof(struct mld_hdr)) /* necessary? */ 621 goto badlen; 622 break; /* nothing to be done in kernel */ 623 624 case MLD_MTRACE_RESP: 625 case MLD_MTRACE: 626 /* XXX: these two are experimental. not officially defined. */ 627 /* XXX: per-interface statistics? */ 628 break; /* just pass it to applications */ 629 630 case ICMP6_WRUREQUEST: /* ICMP6_FQDN_QUERY */ 631 { 632 enum { WRU, FQDN } mode; 633 634 if (!icmp6_nodeinfo) 635 break; 636 637 if (icmp6len == sizeof(struct icmp6_hdr) + 4) 638 mode = WRU; 639 else if (icmp6len >= sizeof(struct icmp6_nodeinfo)) 640 mode = FQDN; 641 else 642 goto badlen; 643 644 #define hostnamelen strlen(hostname) 645 if (mode == FQDN) { 646 #ifndef PULLDOWN_TEST 647 IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_nodeinfo), 648 IPPROTO_DONE); 649 #endif 650 n = m_copy(m, 0, M_COPYALL); 651 if (n) 652 n = ni6_input(n, off); 653 /* XXX meaningless if n == NULL */ 654 noff = sizeof(struct ip6_hdr); 655 } else { 656 u_char *p; 657 int maxlen, maxhlen; 658 659 /* 660 * XXX: this combination of flags is pointless, 661 * but should we keep this for compatibility? 662 */ 663 if ((icmp6_nodeinfo & 5) != 5) 664 break; 665 666 if (code != 0) 667 goto badcode; 668 maxlen = sizeof(*nip6) + sizeof(*nicmp6) + 4; 669 if (maxlen >= MCLBYTES) { 670 /* Give up remote */ 671 break; 672 } 673 MGETHDR(n, M_DONTWAIT, m->m_type); 674 if (n && maxlen > MHLEN) { 675 MCLGET(n, M_DONTWAIT); 676 if ((n->m_flags & M_EXT) == 0) { 677 m_free(n); 678 n = NULL; 679 } 680 } 681 if (n && !m_dup_pkthdr(n, m, M_DONTWAIT)) { 682 /* 683 * Previous code did a blind M_COPY_PKTHDR 684 * and said "just for rcvif". If true, then 685 * we could tolerate the dup failing (due to 686 * the deep copy of the tag chain). For now 687 * be conservative and just fail. 688 */ 689 m_free(n); 690 n = NULL; 691 } 692 if (n == NULL) { 693 /* Give up remote */ 694 break; 695 } 696 n->m_pkthdr.rcvif = NULL; 697 n->m_len = 0; 698 maxhlen = M_TRAILINGSPACE(n) - maxlen; 699 if (maxhlen > hostnamelen) 700 maxhlen = hostnamelen; 701 /* 702 * Copy IPv6 and ICMPv6 only. 703 */ 704 nip6 = mtod(n, struct ip6_hdr *); 705 bcopy(ip6, nip6, sizeof(struct ip6_hdr)); 706 nicmp6 = (struct icmp6_hdr *)(nip6 + 1); 707 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr)); 708 p = (u_char *)(nicmp6 + 1); 709 bzero(p, 4); 710 bcopy(hostname, p + 4, maxhlen); /* meaningless TTL */ 711 noff = sizeof(struct ip6_hdr); 712 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + 713 sizeof(struct icmp6_hdr) + 4 + maxhlen; 714 nicmp6->icmp6_type = ICMP6_WRUREPLY; 715 nicmp6->icmp6_code = 0; 716 } 717 #undef hostnamelen 718 if (n) { 719 icmp6stat.icp6s_reflect++; 720 icmp6stat.icp6s_outhist[ICMP6_WRUREPLY]++; 721 icmp6_reflect(n, noff); 722 } 723 break; 724 } 725 726 case ICMP6_WRUREPLY: 727 if (code != 0) 728 goto badcode; 729 break; 730 731 case ND_ROUTER_SOLICIT: 732 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_routersolicit); 733 if (code != 0) 734 goto badcode; 735 if (icmp6len < sizeof(struct nd_router_solicit)) 736 goto badlen; 737 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 738 /* give up local */ 739 nd6_rs_input(m, off, icmp6len); 740 m = NULL; 741 goto freeit; 742 } 743 nd6_rs_input(n, off, icmp6len); 744 /* m stays. */ 745 break; 746 747 case ND_ROUTER_ADVERT: 748 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_routeradvert); 749 if (code != 0) 750 goto badcode; 751 if (icmp6len < sizeof(struct nd_router_advert)) 752 goto badlen; 753 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 754 /* give up local */ 755 nd6_ra_input(m, off, icmp6len); 756 m = NULL; 757 goto freeit; 758 } 759 nd6_ra_input(n, off, icmp6len); 760 /* m stays. */ 761 break; 762 763 case ND_NEIGHBOR_SOLICIT: 764 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_neighborsolicit); 765 if (code != 0) 766 goto badcode; 767 if (icmp6len < sizeof(struct nd_neighbor_solicit)) 768 goto badlen; 769 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 770 /* give up local */ 771 nd6_ns_input(m, off, icmp6len); 772 m = NULL; 773 goto freeit; 774 } 775 nd6_ns_input(n, off, icmp6len); 776 /* m stays. */ 777 break; 778 779 case ND_NEIGHBOR_ADVERT: 780 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_neighboradvert); 781 if (code != 0) 782 goto badcode; 783 if (icmp6len < sizeof(struct nd_neighbor_advert)) 784 goto badlen; 785 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 786 /* give up local */ 787 nd6_na_input(m, off, icmp6len); 788 m = NULL; 789 goto freeit; 790 } 791 nd6_na_input(n, off, icmp6len); 792 /* m stays. */ 793 break; 794 795 case ND_REDIRECT: 796 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_redirect); 797 if (code != 0) 798 goto badcode; 799 if (icmp6len < sizeof(struct nd_redirect)) 800 goto badlen; 801 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 802 /* give up local */ 803 icmp6_redirect_input(m, off); 804 m = NULL; 805 goto freeit; 806 } 807 icmp6_redirect_input(n, off); 808 /* m stays. */ 809 break; 810 811 case ICMP6_ROUTER_RENUMBERING: 812 if (code != ICMP6_ROUTER_RENUMBERING_COMMAND && 813 code != ICMP6_ROUTER_RENUMBERING_RESULT) 814 goto badcode; 815 if (icmp6len < sizeof(struct icmp6_router_renum)) 816 goto badlen; 817 break; 818 819 default: 820 nd6log((LOG_DEBUG, 821 "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n", 822 icmp6->icmp6_type, ip6_sprintf(ip6bufs, &ip6->ip6_src), 823 ip6_sprintf(ip6bufd, &ip6->ip6_dst), 824 m->m_pkthdr.rcvif ? m->m_pkthdr.rcvif->if_index : 0)); 825 if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) { 826 /* ICMPv6 error: MUST deliver it by spec... */ 827 code = PRC_NCMDS; 828 /* deliver */ 829 } else { 830 /* ICMPv6 informational: MUST not deliver */ 831 break; 832 } 833 deliver: 834 if (icmp6_notify_error(&m, off, icmp6len, code)) { 835 /* In this case, m should've been freed. */ 836 return (IPPROTO_DONE); 837 } 838 break; 839 840 badcode: 841 icmp6stat.icp6s_badcode++; 842 break; 843 844 badlen: 845 icmp6stat.icp6s_badlen++; 846 break; 847 } 848 849 /* deliver the packet to appropriate sockets */ 850 icmp6_rip6_input(&m, *offp); 851 852 return IPPROTO_DONE; 853 854 freeit: 855 m_freem(m); 856 return IPPROTO_DONE; 857 } 858 859 static int 860 icmp6_notify_error(struct mbuf **mp, int off, int icmp6len, int code) 861 { 862 struct mbuf *m = *mp; 863 struct icmp6_hdr *icmp6; 864 struct ip6_hdr *eip6; 865 u_int32_t notifymtu; 866 struct sockaddr_in6 icmp6src, icmp6dst; 867 868 if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) { 869 icmp6stat.icp6s_tooshort++; 870 goto freeit; 871 } 872 #ifndef PULLDOWN_TEST 873 IP6_EXTHDR_CHECK(m, off, 874 sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr), -1); 875 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 876 #else 877 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, 878 sizeof(*icmp6) + sizeof(struct ip6_hdr)); 879 if (icmp6 == NULL) { 880 icmp6stat.icp6s_tooshort++; 881 return (-1); 882 } 883 #endif 884 eip6 = (struct ip6_hdr *)(icmp6 + 1); 885 886 /* Detect the upper level protocol */ 887 { 888 void (*ctlfunc)(int, struct sockaddr *, void *); 889 u_int8_t nxt = eip6->ip6_nxt; 890 int eoff = off + sizeof(struct icmp6_hdr) + 891 sizeof(struct ip6_hdr); 892 struct ip6ctlparam ip6cp; 893 struct in6_addr *finaldst = NULL; 894 int icmp6type = icmp6->icmp6_type; 895 struct ip6_frag *fh; 896 struct ip6_rthdr *rth; 897 struct ip6_rthdr0 *rth0; 898 int rthlen; 899 900 while (1) { /* XXX: should avoid infinite loop explicitly? */ 901 struct ip6_ext *eh; 902 903 switch (nxt) { 904 case IPPROTO_HOPOPTS: 905 case IPPROTO_DSTOPTS: 906 case IPPROTO_AH: 907 #ifndef PULLDOWN_TEST 908 IP6_EXTHDR_CHECK(m, 0, 909 eoff + sizeof(struct ip6_ext), -1); 910 eh = (struct ip6_ext *)(mtod(m, caddr_t) + eoff); 911 #else 912 IP6_EXTHDR_GET(eh, struct ip6_ext *, m, 913 eoff, sizeof(*eh)); 914 if (eh == NULL) { 915 icmp6stat.icp6s_tooshort++; 916 return (-1); 917 } 918 #endif 919 920 if (nxt == IPPROTO_AH) 921 eoff += (eh->ip6e_len + 2) << 2; 922 else 923 eoff += (eh->ip6e_len + 1) << 3; 924 nxt = eh->ip6e_nxt; 925 break; 926 case IPPROTO_ROUTING: 927 /* 928 * When the erroneous packet contains a 929 * routing header, we should examine the 930 * header to determine the final destination. 931 * Otherwise, we can't properly update 932 * information that depends on the final 933 * destination (e.g. path MTU). 934 */ 935 #ifndef PULLDOWN_TEST 936 IP6_EXTHDR_CHECK(m, 0, eoff + sizeof(*rth), -1); 937 rth = (struct ip6_rthdr *) 938 (mtod(m, caddr_t) + eoff); 939 #else 940 IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m, 941 eoff, sizeof(*rth)); 942 if (rth == NULL) { 943 icmp6stat.icp6s_tooshort++; 944 return (-1); 945 } 946 #endif 947 rthlen = (rth->ip6r_len + 1) << 3; 948 /* 949 * XXX: currently there is no 950 * officially defined type other 951 * than type-0. 952 * Note that if the segment left field 953 * is 0, all intermediate hops must 954 * have been passed. 955 */ 956 if (rth->ip6r_segleft && 957 rth->ip6r_type == IPV6_RTHDR_TYPE_0) { 958 int hops; 959 960 #ifndef PULLDOWN_TEST 961 IP6_EXTHDR_CHECK(m, 0, eoff + rthlen, -1); 962 rth0 = (struct ip6_rthdr0 *) 963 (mtod(m, caddr_t) + eoff); 964 #else 965 IP6_EXTHDR_GET(rth0, 966 struct ip6_rthdr0 *, m, 967 eoff, rthlen); 968 if (rth0 == NULL) { 969 icmp6stat.icp6s_tooshort++; 970 return (-1); 971 } 972 #endif 973 /* just ignore a bogus header */ 974 if ((rth0->ip6r0_len % 2) == 0 && 975 (hops = rth0->ip6r0_len/2)) 976 finaldst = (struct in6_addr *)(rth0 + 1) + (hops - 1); 977 } 978 eoff += rthlen; 979 nxt = rth->ip6r_nxt; 980 break; 981 case IPPROTO_FRAGMENT: 982 #ifndef PULLDOWN_TEST 983 IP6_EXTHDR_CHECK(m, 0, eoff + 984 sizeof(struct ip6_frag), -1); 985 fh = (struct ip6_frag *)(mtod(m, caddr_t) + 986 eoff); 987 #else 988 IP6_EXTHDR_GET(fh, struct ip6_frag *, m, 989 eoff, sizeof(*fh)); 990 if (fh == NULL) { 991 icmp6stat.icp6s_tooshort++; 992 return (-1); 993 } 994 #endif 995 /* 996 * Data after a fragment header is meaningless 997 * unless it is the first fragment, but 998 * we'll go to the notify label for path MTU 999 * discovery. 1000 */ 1001 if (fh->ip6f_offlg & IP6F_OFF_MASK) 1002 goto notify; 1003 1004 eoff += sizeof(struct ip6_frag); 1005 nxt = fh->ip6f_nxt; 1006 break; 1007 default: 1008 /* 1009 * This case includes ESP and the No Next 1010 * Header. In such cases going to the notify 1011 * label does not have any meaning 1012 * (i.e. ctlfunc will be NULL), but we go 1013 * anyway since we might have to update 1014 * path MTU information. 1015 */ 1016 goto notify; 1017 } 1018 } 1019 notify: 1020 #ifndef PULLDOWN_TEST 1021 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 1022 #else 1023 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, 1024 sizeof(*icmp6) + sizeof(struct ip6_hdr)); 1025 if (icmp6 == NULL) { 1026 icmp6stat.icp6s_tooshort++; 1027 return (-1); 1028 } 1029 #endif 1030 1031 /* 1032 * retrieve parameters from the inner IPv6 header, and convert 1033 * them into sockaddr structures. 1034 * XXX: there is no guarantee that the source or destination 1035 * addresses of the inner packet are in the same scope as 1036 * the addresses of the icmp packet. But there is no other 1037 * way to determine the zone. 1038 */ 1039 eip6 = (struct ip6_hdr *)(icmp6 + 1); 1040 1041 bzero(&icmp6dst, sizeof(icmp6dst)); 1042 icmp6dst.sin6_len = sizeof(struct sockaddr_in6); 1043 icmp6dst.sin6_family = AF_INET6; 1044 if (finaldst == NULL) 1045 icmp6dst.sin6_addr = eip6->ip6_dst; 1046 else 1047 icmp6dst.sin6_addr = *finaldst; 1048 if (in6_setscope(&icmp6dst.sin6_addr, m->m_pkthdr.rcvif, NULL)) 1049 goto freeit; 1050 bzero(&icmp6src, sizeof(icmp6src)); 1051 icmp6src.sin6_len = sizeof(struct sockaddr_in6); 1052 icmp6src.sin6_family = AF_INET6; 1053 icmp6src.sin6_addr = eip6->ip6_src; 1054 if (in6_setscope(&icmp6src.sin6_addr, m->m_pkthdr.rcvif, NULL)) 1055 goto freeit; 1056 icmp6src.sin6_flowinfo = 1057 (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 (*)(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(struct ip6ctlparam *ip6cp, int validated) 1092 { 1093 struct in6_addr *dst = ip6cp->ip6c_finaldst; 1094 struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6; 1095 struct mbuf *m = ip6cp->ip6c_m; /* will be necessary for scope issue */ 1096 u_int mtu = ntohl(icmp6->icmp6_mtu); 1097 struct in_conninfo inc; 1098 1099 #if 0 1100 /* 1101 * RFC2460 section 5, last paragraph. 1102 * even though minimum link MTU for IPv6 is IPV6_MMTU, 1103 * we may see ICMPv6 too big with mtu < IPV6_MMTU 1104 * due to packet translator in the middle. 1105 * see ip6_output() and ip6_getpmtu() "alwaysfrag" case for 1106 * special handling. 1107 */ 1108 if (mtu < IPV6_MMTU) 1109 return; 1110 #endif 1111 1112 /* 1113 * we reject ICMPv6 too big with abnormally small value. 1114 * XXX what is the good definition of "abnormally small"? 1115 */ 1116 if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8) 1117 return; 1118 1119 if (!validated) 1120 return; 1121 1122 bzero(&inc, sizeof(inc)); 1123 inc.inc_flags = 1; /* IPv6 */ 1124 inc.inc6_faddr = *dst; 1125 if (in6_setscope(&inc.inc6_faddr, m->m_pkthdr.rcvif, NULL)) 1126 return; 1127 1128 if (mtu < tcp_maxmtu6(&inc, NULL)) { 1129 tcp_hc_updatemtu(&inc, mtu); 1130 icmp6stat.icp6s_pmtuchg++; 1131 } 1132 } 1133 1134 /* 1135 * Process a Node Information Query packet, based on 1136 * draft-ietf-ipngwg-icmp-name-lookups-07. 1137 * 1138 * Spec incompatibilities: 1139 * - IPv6 Subject address handling 1140 * - IPv4 Subject address handling support missing 1141 * - Proxy reply (answer even if it's not for me) 1142 * - joins NI group address at in6_ifattach() time only, does not cope 1143 * with hostname changes by sethostname(3) 1144 */ 1145 #define hostnamelen strlen(hostname) 1146 static struct mbuf * 1147 ni6_input(struct mbuf *m, int off) 1148 { 1149 struct icmp6_nodeinfo *ni6, *nni6; 1150 struct mbuf *n = NULL; 1151 u_int16_t qtype; 1152 int subjlen; 1153 int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); 1154 struct ni_reply_fqdn *fqdn; 1155 int addrs; /* for NI_QTYPE_NODEADDR */ 1156 struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */ 1157 struct in6_addr in6_subj; /* subject address */ 1158 struct ip6_hdr *ip6; 1159 int oldfqdn = 0; /* if 1, return pascal string (03 draft) */ 1160 char *subj = NULL; 1161 struct in6_ifaddr *ia6 = NULL; 1162 1163 ip6 = mtod(m, struct ip6_hdr *); 1164 #ifndef PULLDOWN_TEST 1165 ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off); 1166 #else 1167 IP6_EXTHDR_GET(ni6, struct icmp6_nodeinfo *, m, off, sizeof(*ni6)); 1168 if (ni6 == NULL) { 1169 /* m is already reclaimed */ 1170 return (NULL); 1171 } 1172 #endif 1173 1174 /* 1175 * Validate IPv6 source address. 1176 * The default configuration MUST be to refuse answering queries from 1177 * global-scope addresses according to RFC4602. 1178 * Notes: 1179 * - it's not very clear what "refuse" means; this implementation 1180 * simply drops it. 1181 * - it's not very easy to identify global-scope (unicast) addresses 1182 * since there are many prefixes for them. It should be safer 1183 * and in practice sufficient to check "all" but loopback and 1184 * link-local (note that site-local unicast was deprecated and 1185 * ULA is defined as global scope-wise) 1186 */ 1187 if ((icmp6_nodeinfo & ICMP6_NODEINFO_GLOBALOK) == 0 && 1188 !IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) && 1189 !IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) 1190 goto bad; 1191 1192 /* 1193 * Validate IPv6 destination address. 1194 * 1195 * The Responder must discard the Query without further processing 1196 * unless it is one of the Responder's unicast or anycast addresses, or 1197 * a link-local scope multicast address which the Responder has joined. 1198 * [RFC4602, Section 5.] 1199 */ 1200 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 1201 if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst)) 1202 goto bad; 1203 /* else it's a link-local multicast, fine */ 1204 } else { /* unicast or anycast */ 1205 if ((ia6 = ip6_getdstifaddr(m)) == NULL) 1206 goto bad; /* XXX impossible */ 1207 1208 if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) && 1209 !(icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK)) { 1210 nd6log((LOG_DEBUG, "ni6_input: ignore node info to " 1211 "a temporary address in %s:%d", 1212 __FILE__, __LINE__)); 1213 goto bad; 1214 } 1215 } 1216 1217 /* validate query Subject field. */ 1218 qtype = ntohs(ni6->ni_qtype); 1219 subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo); 1220 switch (qtype) { 1221 case NI_QTYPE_NOOP: 1222 case NI_QTYPE_SUPTYPES: 1223 /* 07 draft */ 1224 if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0) 1225 break; 1226 /* FALLTHROUGH */ 1227 case NI_QTYPE_FQDN: 1228 case NI_QTYPE_NODEADDR: 1229 case NI_QTYPE_IPV4ADDR: 1230 switch (ni6->ni_code) { 1231 case ICMP6_NI_SUBJ_IPV6: 1232 #if ICMP6_NI_SUBJ_IPV6 != 0 1233 case 0: 1234 #endif 1235 /* 1236 * backward compatibility - try to accept 03 draft 1237 * format, where no Subject is present. 1238 */ 1239 if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 && 1240 subjlen == 0) { 1241 oldfqdn++; 1242 break; 1243 } 1244 #if ICMP6_NI_SUBJ_IPV6 != 0 1245 if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6) 1246 goto bad; 1247 #endif 1248 1249 if (subjlen != sizeof(struct in6_addr)) 1250 goto bad; 1251 1252 /* 1253 * Validate Subject address. 1254 * 1255 * Not sure what exactly "address belongs to the node" 1256 * means in the spec, is it just unicast, or what? 1257 * 1258 * At this moment we consider Subject address as 1259 * "belong to the node" if the Subject address equals 1260 * to the IPv6 destination address; validation for 1261 * IPv6 destination address should have done enough 1262 * check for us. 1263 * 1264 * We do not do proxy at this moment. 1265 */ 1266 /* m_pulldown instead of copy? */ 1267 m_copydata(m, off + sizeof(struct icmp6_nodeinfo), 1268 subjlen, (caddr_t)&in6_subj); 1269 if (in6_setscope(&in6_subj, m->m_pkthdr.rcvif, NULL)) 1270 goto bad; 1271 1272 subj = (char *)&in6_subj; 1273 if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &in6_subj)) 1274 break; 1275 1276 /* 1277 * XXX if we are to allow other cases, we should really 1278 * be careful about scope here. 1279 * basically, we should disallow queries toward IPv6 1280 * destination X with subject Y, 1281 * if scope(X) > scope(Y). 1282 * if we allow scope(X) > scope(Y), it will result in 1283 * information leakage across scope boundary. 1284 */ 1285 goto bad; 1286 1287 case ICMP6_NI_SUBJ_FQDN: 1288 /* 1289 * Validate Subject name with gethostname(3). 1290 * 1291 * The behavior may need some debate, since: 1292 * - we are not sure if the node has FQDN as 1293 * hostname (returned by gethostname(3)). 1294 * - the code does wildcard match for truncated names. 1295 * however, we are not sure if we want to perform 1296 * wildcard match, if gethostname(3) side has 1297 * truncated hostname. 1298 */ 1299 n = ni6_nametodns(hostname, hostnamelen, 0); 1300 if (!n || n->m_next || n->m_len == 0) 1301 goto bad; 1302 IP6_EXTHDR_GET(subj, char *, m, 1303 off + sizeof(struct icmp6_nodeinfo), subjlen); 1304 if (subj == NULL) 1305 goto bad; 1306 if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *), 1307 n->m_len)) { 1308 goto bad; 1309 } 1310 m_freem(n); 1311 n = NULL; 1312 break; 1313 1314 case ICMP6_NI_SUBJ_IPV4: /* XXX: to be implemented? */ 1315 default: 1316 goto bad; 1317 } 1318 break; 1319 } 1320 1321 /* refuse based on configuration. XXX ICMP6_NI_REFUSED? */ 1322 switch (qtype) { 1323 case NI_QTYPE_FQDN: 1324 if ((icmp6_nodeinfo & ICMP6_NODEINFO_FQDNOK) == 0) 1325 goto bad; 1326 break; 1327 case NI_QTYPE_NODEADDR: 1328 case NI_QTYPE_IPV4ADDR: 1329 if ((icmp6_nodeinfo & ICMP6_NODEINFO_NODEADDROK) == 0) 1330 goto bad; 1331 break; 1332 } 1333 1334 /* guess reply length */ 1335 switch (qtype) { 1336 case NI_QTYPE_NOOP: 1337 break; /* no reply data */ 1338 case NI_QTYPE_SUPTYPES: 1339 replylen += sizeof(u_int32_t); 1340 break; 1341 case NI_QTYPE_FQDN: 1342 /* XXX will append an mbuf */ 1343 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); 1344 break; 1345 case NI_QTYPE_NODEADDR: 1346 addrs = ni6_addrs(ni6, m, &ifp, (struct in6_addr *)subj); 1347 if ((replylen += addrs * (sizeof(struct in6_addr) + 1348 sizeof(u_int32_t))) > MCLBYTES) 1349 replylen = MCLBYTES; /* XXX: will truncate pkt later */ 1350 break; 1351 case NI_QTYPE_IPV4ADDR: 1352 /* unsupported - should respond with unknown Qtype? */ 1353 break; 1354 default: 1355 /* 1356 * XXX: We must return a reply with the ICMP6 code 1357 * `unknown Qtype' in this case. However we regard the case 1358 * as an FQDN query for backward compatibility. 1359 * Older versions set a random value to this field, 1360 * so it rarely varies in the defined qtypes. 1361 * But the mechanism is not reliable... 1362 * maybe we should obsolete older versions. 1363 */ 1364 qtype = NI_QTYPE_FQDN; 1365 /* XXX will append an mbuf */ 1366 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); 1367 oldfqdn++; 1368 break; 1369 } 1370 1371 /* allocate an mbuf to reply. */ 1372 MGETHDR(n, M_DONTWAIT, m->m_type); 1373 if (n == NULL) { 1374 m_freem(m); 1375 return (NULL); 1376 } 1377 M_MOVE_PKTHDR(n, m); /* just for recvif */ 1378 if (replylen > MHLEN) { 1379 if (replylen > MCLBYTES) { 1380 /* 1381 * XXX: should we try to allocate more? But MCLBYTES 1382 * is probably much larger than IPV6_MMTU... 1383 */ 1384 goto bad; 1385 } 1386 MCLGET(n, M_DONTWAIT); 1387 if ((n->m_flags & M_EXT) == 0) { 1388 goto bad; 1389 } 1390 } 1391 n->m_pkthdr.len = n->m_len = replylen; 1392 1393 /* copy mbuf header and IPv6 + Node Information base headers */ 1394 bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr)); 1395 nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1); 1396 bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo)); 1397 1398 /* qtype dependent procedure */ 1399 switch (qtype) { 1400 case NI_QTYPE_NOOP: 1401 nni6->ni_code = ICMP6_NI_SUCCESS; 1402 nni6->ni_flags = 0; 1403 break; 1404 case NI_QTYPE_SUPTYPES: 1405 { 1406 u_int32_t v; 1407 nni6->ni_code = ICMP6_NI_SUCCESS; 1408 nni6->ni_flags = htons(0x0000); /* raw bitmap */ 1409 /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */ 1410 v = (u_int32_t)htonl(0x0000000f); 1411 bcopy(&v, nni6 + 1, sizeof(u_int32_t)); 1412 break; 1413 } 1414 case NI_QTYPE_FQDN: 1415 nni6->ni_code = ICMP6_NI_SUCCESS; 1416 fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) + 1417 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo)); 1418 nni6->ni_flags = 0; /* XXX: meaningless TTL */ 1419 fqdn->ni_fqdn_ttl = 0; /* ditto. */ 1420 /* 1421 * XXX do we really have FQDN in variable "hostname"? 1422 */ 1423 n->m_next = ni6_nametodns(hostname, hostnamelen, oldfqdn); 1424 if (n->m_next == NULL) 1425 goto bad; 1426 /* XXX we assume that n->m_next is not a chain */ 1427 if (n->m_next->m_next != NULL) 1428 goto bad; 1429 n->m_pkthdr.len += n->m_next->m_len; 1430 break; 1431 case NI_QTYPE_NODEADDR: 1432 { 1433 int lenlim, copied; 1434 1435 nni6->ni_code = ICMP6_NI_SUCCESS; 1436 n->m_pkthdr.len = n->m_len = 1437 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); 1438 lenlim = M_TRAILINGSPACE(n); 1439 copied = ni6_store_addrs(ni6, nni6, ifp, lenlim); 1440 /* XXX: reset mbuf length */ 1441 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + 1442 sizeof(struct icmp6_nodeinfo) + copied; 1443 break; 1444 } 1445 default: 1446 break; /* XXX impossible! */ 1447 } 1448 1449 nni6->ni_type = ICMP6_NI_REPLY; 1450 m_freem(m); 1451 return (n); 1452 1453 bad: 1454 m_freem(m); 1455 if (n) 1456 m_freem(n); 1457 return (NULL); 1458 } 1459 #undef hostnamelen 1460 1461 /* 1462 * make a mbuf with DNS-encoded string. no compression support. 1463 * 1464 * XXX names with less than 2 dots (like "foo" or "foo.section") will be 1465 * treated as truncated name (two \0 at the end). this is a wild guess. 1466 * 1467 * old - return pascal string if non-zero 1468 */ 1469 static struct mbuf * 1470 ni6_nametodns(const char *name, int namelen, int old) 1471 { 1472 struct mbuf *m; 1473 char *cp, *ep; 1474 const char *p, *q; 1475 int i, len, nterm; 1476 1477 if (old) 1478 len = namelen + 1; 1479 else 1480 len = MCLBYTES; 1481 1482 /* because MAXHOSTNAMELEN is usually 256, we use cluster mbuf */ 1483 MGET(m, M_DONTWAIT, MT_DATA); 1484 if (m && len > MLEN) { 1485 MCLGET(m, M_DONTWAIT); 1486 if ((m->m_flags & M_EXT) == 0) 1487 goto fail; 1488 } 1489 if (!m) 1490 goto fail; 1491 m->m_next = NULL; 1492 1493 if (old) { 1494 m->m_len = len; 1495 *mtod(m, char *) = namelen; 1496 bcopy(name, mtod(m, char *) + 1, namelen); 1497 return m; 1498 } else { 1499 m->m_len = 0; 1500 cp = mtod(m, char *); 1501 ep = mtod(m, char *) + M_TRAILINGSPACE(m); 1502 1503 /* if not certain about my name, return empty buffer */ 1504 if (namelen == 0) 1505 return m; 1506 1507 /* 1508 * guess if it looks like shortened hostname, or FQDN. 1509 * shortened hostname needs two trailing "\0". 1510 */ 1511 i = 0; 1512 for (p = name; p < name + namelen; p++) { 1513 if (*p && *p == '.') 1514 i++; 1515 } 1516 if (i < 2) 1517 nterm = 2; 1518 else 1519 nterm = 1; 1520 1521 p = name; 1522 while (cp < ep && p < name + namelen) { 1523 i = 0; 1524 for (q = p; q < name + namelen && *q && *q != '.'; q++) 1525 i++; 1526 /* result does not fit into mbuf */ 1527 if (cp + i + 1 >= ep) 1528 goto fail; 1529 /* 1530 * DNS label length restriction, RFC1035 page 8. 1531 * "i == 0" case is included here to avoid returning 1532 * 0-length label on "foo..bar". 1533 */ 1534 if (i <= 0 || i >= 64) 1535 goto fail; 1536 *cp++ = i; 1537 bcopy(p, cp, i); 1538 cp += i; 1539 p = q; 1540 if (p < name + namelen && *p == '.') 1541 p++; 1542 } 1543 /* termination */ 1544 if (cp + nterm >= ep) 1545 goto fail; 1546 while (nterm-- > 0) 1547 *cp++ = '\0'; 1548 m->m_len = cp - mtod(m, char *); 1549 return m; 1550 } 1551 1552 panic("should not reach here"); 1553 /* NOTREACHED */ 1554 1555 fail: 1556 if (m) 1557 m_freem(m); 1558 return NULL; 1559 } 1560 1561 /* 1562 * check if two DNS-encoded string matches. takes care of truncated 1563 * form (with \0\0 at the end). no compression support. 1564 * XXX upper/lowercase match (see RFC2065) 1565 */ 1566 static int 1567 ni6_dnsmatch(const char *a, int alen, const char *b, int blen) 1568 { 1569 const char *a0, *b0; 1570 int l; 1571 1572 /* simplest case - need validation? */ 1573 if (alen == blen && bcmp(a, b, alen) == 0) 1574 return 1; 1575 1576 a0 = a; 1577 b0 = b; 1578 1579 /* termination is mandatory */ 1580 if (alen < 2 || blen < 2) 1581 return 0; 1582 if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0') 1583 return 0; 1584 alen--; 1585 blen--; 1586 1587 while (a - a0 < alen && b - b0 < blen) { 1588 if (a - a0 + 1 > alen || b - b0 + 1 > blen) 1589 return 0; 1590 1591 if ((signed char)a[0] < 0 || (signed char)b[0] < 0) 1592 return 0; 1593 /* we don't support compression yet */ 1594 if (a[0] >= 64 || b[0] >= 64) 1595 return 0; 1596 1597 /* truncated case */ 1598 if (a[0] == 0 && a - a0 == alen - 1) 1599 return 1; 1600 if (b[0] == 0 && b - b0 == blen - 1) 1601 return 1; 1602 if (a[0] == 0 || b[0] == 0) 1603 return 0; 1604 1605 if (a[0] != b[0]) 1606 return 0; 1607 l = a[0]; 1608 if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen) 1609 return 0; 1610 if (bcmp(a + 1, b + 1, l) != 0) 1611 return 0; 1612 1613 a += 1 + l; 1614 b += 1 + l; 1615 } 1616 1617 if (a - a0 == alen && b - b0 == blen) 1618 return 1; 1619 else 1620 return 0; 1621 } 1622 1623 /* 1624 * calculate the number of addresses to be returned in the node info reply. 1625 */ 1626 static int 1627 ni6_addrs(struct icmp6_nodeinfo *ni6, struct mbuf *m, struct ifnet **ifpp, 1628 struct in6_addr *subj) 1629 { 1630 struct ifnet *ifp; 1631 struct in6_ifaddr *ifa6; 1632 struct ifaddr *ifa; 1633 int addrs = 0, addrsofif, iffound = 0; 1634 int niflags = ni6->ni_flags; 1635 1636 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) { 1637 switch (ni6->ni_code) { 1638 case ICMP6_NI_SUBJ_IPV6: 1639 if (subj == NULL) /* must be impossible... */ 1640 return (0); 1641 break; 1642 default: 1643 /* 1644 * XXX: we only support IPv6 subject address for 1645 * this Qtype. 1646 */ 1647 return (0); 1648 } 1649 } 1650 1651 IFNET_RLOCK(); 1652 for (ifp = TAILQ_FIRST(&ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list)) { 1653 addrsofif = 0; 1654 TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) { 1655 if (ifa->ifa_addr->sa_family != AF_INET6) 1656 continue; 1657 ifa6 = (struct in6_ifaddr *)ifa; 1658 1659 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 && 1660 IN6_ARE_ADDR_EQUAL(subj, &ifa6->ia_addr.sin6_addr)) 1661 iffound = 1; 1662 1663 /* 1664 * IPv4-mapped addresses can only be returned by a 1665 * Node Information proxy, since they represent 1666 * addresses of IPv4-only nodes, which perforce do 1667 * not implement this protocol. 1668 * [icmp-name-lookups-07, Section 5.4] 1669 * So we don't support NI_NODEADDR_FLAG_COMPAT in 1670 * this function at this moment. 1671 */ 1672 1673 /* What do we have to do about ::1? */ 1674 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { 1675 case IPV6_ADDR_SCOPE_LINKLOCAL: 1676 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) 1677 continue; 1678 break; 1679 case IPV6_ADDR_SCOPE_SITELOCAL: 1680 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) 1681 continue; 1682 break; 1683 case IPV6_ADDR_SCOPE_GLOBAL: 1684 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) 1685 continue; 1686 break; 1687 default: 1688 continue; 1689 } 1690 1691 /* 1692 * check if anycast is okay. 1693 * XXX: just experimental. not in the spec. 1694 */ 1695 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && 1696 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) 1697 continue; /* we need only unicast addresses */ 1698 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && 1699 (icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) { 1700 continue; 1701 } 1702 addrsofif++; /* count the address */ 1703 } 1704 if (iffound) { 1705 *ifpp = ifp; 1706 IFNET_RUNLOCK(); 1707 return (addrsofif); 1708 } 1709 1710 addrs += addrsofif; 1711 } 1712 IFNET_RUNLOCK(); 1713 1714 return (addrs); 1715 } 1716 1717 static int 1718 ni6_store_addrs(struct icmp6_nodeinfo *ni6, struct icmp6_nodeinfo *nni6, 1719 struct ifnet *ifp0, int resid) 1720 { 1721 struct ifnet *ifp = ifp0 ? ifp0 : TAILQ_FIRST(&ifnet); 1722 struct in6_ifaddr *ifa6; 1723 struct ifaddr *ifa; 1724 struct ifnet *ifp_dep = NULL; 1725 int copied = 0, allow_deprecated = 0; 1726 u_char *cp = (u_char *)(nni6 + 1); 1727 int niflags = ni6->ni_flags; 1728 u_int32_t ltime; 1729 1730 if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL)) 1731 return (0); /* needless to copy */ 1732 1733 IFNET_RLOCK(); 1734 again: 1735 1736 for (; ifp; ifp = TAILQ_NEXT(ifp, if_list)) { 1737 for (ifa = ifp->if_addrlist.tqh_first; ifa; 1738 ifa = ifa->ifa_list.tqe_next) { 1739 if (ifa->ifa_addr->sa_family != AF_INET6) 1740 continue; 1741 ifa6 = (struct in6_ifaddr *)ifa; 1742 1743 if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 && 1744 allow_deprecated == 0) { 1745 /* 1746 * prefererred address should be put before 1747 * deprecated addresses. 1748 */ 1749 1750 /* record the interface for later search */ 1751 if (ifp_dep == NULL) 1752 ifp_dep = ifp; 1753 1754 continue; 1755 } else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 && 1756 allow_deprecated != 0) 1757 continue; /* we now collect deprecated addrs */ 1758 1759 /* What do we have to do about ::1? */ 1760 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { 1761 case IPV6_ADDR_SCOPE_LINKLOCAL: 1762 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) 1763 continue; 1764 break; 1765 case IPV6_ADDR_SCOPE_SITELOCAL: 1766 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) 1767 continue; 1768 break; 1769 case IPV6_ADDR_SCOPE_GLOBAL: 1770 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) 1771 continue; 1772 break; 1773 default: 1774 continue; 1775 } 1776 1777 /* 1778 * check if anycast is okay. 1779 * XXX: just experimental. not in the spec. 1780 */ 1781 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && 1782 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) 1783 continue; 1784 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && 1785 (icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) { 1786 continue; 1787 } 1788 1789 /* now we can copy the address */ 1790 if (resid < sizeof(struct in6_addr) + 1791 sizeof(u_int32_t)) { 1792 /* 1793 * We give up much more copy. 1794 * Set the truncate flag and return. 1795 */ 1796 nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE; 1797 IFNET_RUNLOCK(); 1798 return (copied); 1799 } 1800 1801 /* 1802 * Set the TTL of the address. 1803 * The TTL value should be one of the following 1804 * according to the specification: 1805 * 1806 * 1. The remaining lifetime of a DHCP lease on the 1807 * address, or 1808 * 2. The remaining Valid Lifetime of a prefix from 1809 * which the address was derived through Stateless 1810 * Autoconfiguration. 1811 * 1812 * Note that we currently do not support stateful 1813 * address configuration by DHCPv6, so the former 1814 * case can't happen. 1815 */ 1816 if (ifa6->ia6_lifetime.ia6t_expire == 0) 1817 ltime = ND6_INFINITE_LIFETIME; 1818 else { 1819 if (ifa6->ia6_lifetime.ia6t_expire > 1820 time_second) 1821 ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_second); 1822 else 1823 ltime = 0; 1824 } 1825 1826 bcopy(<ime, cp, sizeof(u_int32_t)); 1827 cp += sizeof(u_int32_t); 1828 1829 /* copy the address itself */ 1830 bcopy(&ifa6->ia_addr.sin6_addr, cp, 1831 sizeof(struct in6_addr)); 1832 in6_clearscope((struct in6_addr *)cp); /* XXX */ 1833 cp += sizeof(struct in6_addr); 1834 1835 resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t)); 1836 copied += (sizeof(struct in6_addr) + sizeof(u_int32_t)); 1837 } 1838 if (ifp0) /* we need search only on the specified IF */ 1839 break; 1840 } 1841 1842 if (allow_deprecated == 0 && ifp_dep != NULL) { 1843 ifp = ifp_dep; 1844 allow_deprecated = 1; 1845 1846 goto again; 1847 } 1848 1849 IFNET_RUNLOCK(); 1850 1851 return (copied); 1852 } 1853 1854 /* 1855 * XXX almost dup'ed code with rip6_input. 1856 */ 1857 static int 1858 icmp6_rip6_input(struct mbuf **mp, int off) 1859 { 1860 struct mbuf *m = *mp; 1861 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1862 struct in6pcb *in6p; 1863 struct in6pcb *last = NULL; 1864 struct sockaddr_in6 fromsa; 1865 struct icmp6_hdr *icmp6; 1866 struct mbuf *opts = NULL; 1867 1868 #ifndef PULLDOWN_TEST 1869 /* this is assumed to be safe. */ 1870 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off); 1871 #else 1872 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6)); 1873 if (icmp6 == NULL) { 1874 /* m is already reclaimed */ 1875 return (IPPROTO_DONE); 1876 } 1877 #endif 1878 1879 /* 1880 * XXX: the address may have embedded scope zone ID, which should be 1881 * hidden from applications. 1882 */ 1883 bzero(&fromsa, sizeof(fromsa)); 1884 fromsa.sin6_family = AF_INET6; 1885 fromsa.sin6_len = sizeof(struct sockaddr_in6); 1886 fromsa.sin6_addr = ip6->ip6_src; 1887 if (sa6_recoverscope(&fromsa)) { 1888 m_freem(m); 1889 return (IPPROTO_DONE); 1890 } 1891 1892 INP_INFO_RLOCK(&ripcbinfo); 1893 LIST_FOREACH(in6p, &ripcb, inp_list) { 1894 INP_RLOCK(in6p); 1895 if ((in6p->inp_vflag & INP_IPV6) == 0) { 1896 docontinue: 1897 INP_RUNLOCK(in6p); 1898 continue; 1899 } 1900 if (in6p->in6p_ip6_nxt != IPPROTO_ICMPV6) 1901 goto docontinue; 1902 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) && 1903 !IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &ip6->ip6_dst)) 1904 goto docontinue; 1905 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr) && 1906 !IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src)) 1907 goto docontinue; 1908 if (in6p->in6p_icmp6filt 1909 && ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type, 1910 in6p->in6p_icmp6filt)) 1911 goto docontinue; 1912 if (last) { 1913 struct mbuf *n = NULL; 1914 1915 /* 1916 * Recent network drivers tend to allocate a single 1917 * mbuf cluster, rather than to make a couple of 1918 * mbufs without clusters. Also, since the IPv6 code 1919 * path tries to avoid m_pullup(), it is highly 1920 * probable that we still have an mbuf cluster here 1921 * even though the necessary length can be stored in an 1922 * mbuf's internal buffer. 1923 * Meanwhile, the default size of the receive socket 1924 * buffer for raw sockets is not so large. This means 1925 * the possibility of packet loss is relatively higher 1926 * than before. To avoid this scenario, we copy the 1927 * received data to a separate mbuf that does not use 1928 * a cluster, if possible. 1929 * XXX: it is better to copy the data after stripping 1930 * intermediate headers. 1931 */ 1932 if ((m->m_flags & M_EXT) && m->m_next == NULL && 1933 m->m_len <= MHLEN) { 1934 MGET(n, M_DONTWAIT, m->m_type); 1935 if (n != NULL) { 1936 if (m_dup_pkthdr(n, m, M_NOWAIT)) { 1937 bcopy(m->m_data, n->m_data, 1938 m->m_len); 1939 n->m_len = m->m_len; 1940 } else { 1941 m_free(n); 1942 n = NULL; 1943 } 1944 } 1945 } 1946 if (n != NULL || 1947 (n = m_copy(m, 0, (int)M_COPYALL)) != NULL) { 1948 if (last->in6p_flags & IN6P_CONTROLOPTS) 1949 ip6_savecontrol(last, n, &opts); 1950 /* strip intermediate headers */ 1951 m_adj(n, off); 1952 SOCKBUF_LOCK(&last->in6p_socket->so_rcv); 1953 if (sbappendaddr_locked( 1954 &last->in6p_socket->so_rcv, 1955 (struct sockaddr *)&fromsa, n, opts) 1956 == 0) { 1957 /* should notify about lost packet */ 1958 m_freem(n); 1959 if (opts) { 1960 m_freem(opts); 1961 } 1962 SOCKBUF_UNLOCK( 1963 &last->in6p_socket->so_rcv); 1964 } else 1965 sorwakeup_locked(last->in6p_socket); 1966 opts = NULL; 1967 } 1968 INP_RUNLOCK(last); 1969 } 1970 last = in6p; 1971 } 1972 if (last) { 1973 if (last->in6p_flags & IN6P_CONTROLOPTS) 1974 ip6_savecontrol(last, m, &opts); 1975 /* strip intermediate headers */ 1976 m_adj(m, off); 1977 1978 /* avoid using mbuf clusters if possible (see above) */ 1979 if ((m->m_flags & M_EXT) && m->m_next == NULL && 1980 m->m_len <= MHLEN) { 1981 struct mbuf *n; 1982 1983 MGET(n, M_DONTWAIT, m->m_type); 1984 if (n != NULL) { 1985 if (m_dup_pkthdr(n, m, M_NOWAIT)) { 1986 bcopy(m->m_data, n->m_data, m->m_len); 1987 n->m_len = m->m_len; 1988 1989 m_freem(m); 1990 m = n; 1991 } else { 1992 m_freem(n); 1993 n = NULL; 1994 } 1995 } 1996 } 1997 SOCKBUF_LOCK(&last->in6p_socket->so_rcv); 1998 if (sbappendaddr_locked(&last->in6p_socket->so_rcv, 1999 (struct sockaddr *)&fromsa, m, opts) == 0) { 2000 m_freem(m); 2001 if (opts) 2002 m_freem(opts); 2003 SOCKBUF_UNLOCK(&last->in6p_socket->so_rcv); 2004 } else 2005 sorwakeup_locked(last->in6p_socket); 2006 INP_RUNLOCK(last); 2007 } else { 2008 m_freem(m); 2009 ip6stat.ip6s_delivered--; 2010 } 2011 INP_INFO_RUNLOCK(&ripcbinfo); 2012 return IPPROTO_DONE; 2013 } 2014 2015 /* 2016 * Reflect the ip6 packet back to the source. 2017 * OFF points to the icmp6 header, counted from the top of the mbuf. 2018 */ 2019 void 2020 icmp6_reflect(struct mbuf *m, size_t off) 2021 { 2022 struct ip6_hdr *ip6; 2023 struct icmp6_hdr *icmp6; 2024 struct in6_ifaddr *ia; 2025 int plen; 2026 int type, code; 2027 struct ifnet *outif = NULL; 2028 struct in6_addr origdst, *src = NULL; 2029 2030 /* too short to reflect */ 2031 if (off < sizeof(struct ip6_hdr)) { 2032 nd6log((LOG_DEBUG, 2033 "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n", 2034 (u_long)off, (u_long)sizeof(struct ip6_hdr), 2035 __FILE__, __LINE__)); 2036 goto bad; 2037 } 2038 2039 /* 2040 * If there are extra headers between IPv6 and ICMPv6, strip 2041 * off that header first. 2042 */ 2043 #ifdef DIAGNOSTIC 2044 if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN) 2045 panic("assumption failed in icmp6_reflect"); 2046 #endif 2047 if (off > sizeof(struct ip6_hdr)) { 2048 size_t l; 2049 struct ip6_hdr nip6; 2050 2051 l = off - sizeof(struct ip6_hdr); 2052 m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6); 2053 m_adj(m, l); 2054 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 2055 if (m->m_len < l) { 2056 if ((m = m_pullup(m, l)) == NULL) 2057 return; 2058 } 2059 bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6)); 2060 } else /* off == sizeof(struct ip6_hdr) */ { 2061 size_t 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 } 2068 plen = m->m_pkthdr.len - sizeof(struct ip6_hdr); 2069 ip6 = mtod(m, struct ip6_hdr *); 2070 ip6->ip6_nxt = IPPROTO_ICMPV6; 2071 icmp6 = (struct icmp6_hdr *)(ip6 + 1); 2072 type = icmp6->icmp6_type; /* keep type for statistics */ 2073 code = icmp6->icmp6_code; /* ditto. */ 2074 2075 origdst = ip6->ip6_dst; 2076 /* 2077 * ip6_input() drops a packet if its src is multicast. 2078 * So, the src is never multicast. 2079 */ 2080 ip6->ip6_dst = ip6->ip6_src; 2081 2082 /* 2083 * If the incoming packet was addressed directly to us (i.e. unicast), 2084 * use dst as the src for the reply. 2085 * The IN6_IFF_NOTREADY case should be VERY rare, but is possible 2086 * (for example) when we encounter an error while forwarding procedure 2087 * destined to a duplicated address of ours. 2088 * Note that ip6_getdstifaddr() may fail if we are in an error handling 2089 * procedure of an outgoing packet of our own, in which case we need 2090 * to search in the ifaddr list. 2091 */ 2092 if (!IN6_IS_ADDR_MULTICAST(&origdst)) { 2093 if ((ia = ip6_getdstifaddr(m))) { 2094 if (!(ia->ia6_flags & 2095 (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) 2096 src = &ia->ia_addr.sin6_addr; 2097 } else { 2098 struct sockaddr_in6 d; 2099 2100 bzero(&d, sizeof(d)); 2101 d.sin6_family = AF_INET6; 2102 d.sin6_len = sizeof(d); 2103 d.sin6_addr = origdst; 2104 ia = (struct in6_ifaddr *) 2105 ifa_ifwithaddr((struct sockaddr *)&d); 2106 if (ia && 2107 !(ia->ia6_flags & 2108 (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) { 2109 src = &ia->ia_addr.sin6_addr; 2110 } 2111 } 2112 } 2113 2114 if (src == NULL) { 2115 int e; 2116 struct sockaddr_in6 sin6; 2117 struct route_in6 ro; 2118 2119 /* 2120 * This case matches to multicasts, our anycast, or unicasts 2121 * that we do not own. Select a source address based on the 2122 * source address of the erroneous packet. 2123 */ 2124 bzero(&sin6, sizeof(sin6)); 2125 sin6.sin6_family = AF_INET6; 2126 sin6.sin6_len = sizeof(sin6); 2127 sin6.sin6_addr = ip6->ip6_dst; /* zone ID should be embedded */ 2128 2129 bzero(&ro, sizeof(ro)); 2130 src = in6_selectsrc(&sin6, NULL, NULL, &ro, NULL, &outif, &e); 2131 if (ro.ro_rt) 2132 RTFREE(ro.ro_rt); /* XXX: we could use this */ 2133 if (src == NULL) { 2134 char ip6buf[INET6_ADDRSTRLEN]; 2135 nd6log((LOG_DEBUG, 2136 "icmp6_reflect: source can't be determined: " 2137 "dst=%s, error=%d\n", 2138 ip6_sprintf(ip6buf, &sin6.sin6_addr), e)); 2139 goto bad; 2140 } 2141 } 2142 2143 ip6->ip6_src = *src; 2144 ip6->ip6_flow = 0; 2145 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2146 ip6->ip6_vfc |= IPV6_VERSION; 2147 ip6->ip6_nxt = IPPROTO_ICMPV6; 2148 if (outif) 2149 ip6->ip6_hlim = ND_IFINFO(outif)->chlim; 2150 else if (m->m_pkthdr.rcvif) { 2151 /* XXX: This may not be the outgoing interface */ 2152 ip6->ip6_hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim; 2153 } else 2154 ip6->ip6_hlim = ip6_defhlim; 2155 2156 icmp6->icmp6_cksum = 0; 2157 icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2158 sizeof(struct ip6_hdr), plen); 2159 2160 /* 2161 * XXX option handling 2162 */ 2163 2164 m->m_flags &= ~(M_BCAST|M_MCAST); 2165 2166 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2167 if (outif) 2168 icmp6_ifoutstat_inc(outif, type, code); 2169 2170 return; 2171 2172 bad: 2173 m_freem(m); 2174 return; 2175 } 2176 2177 void 2178 icmp6_fasttimo(void) 2179 { 2180 2181 return; 2182 } 2183 2184 static const char * 2185 icmp6_redirect_diag(struct in6_addr *src6, struct in6_addr *dst6, 2186 struct in6_addr *tgt6) 2187 { 2188 static char buf[1024]; 2189 char ip6bufs[INET6_ADDRSTRLEN]; 2190 char ip6bufd[INET6_ADDRSTRLEN]; 2191 char ip6buft[INET6_ADDRSTRLEN]; 2192 snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)", 2193 ip6_sprintf(ip6bufs, src6), ip6_sprintf(ip6bufd, dst6), 2194 ip6_sprintf(ip6buft, tgt6)); 2195 return buf; 2196 } 2197 2198 void 2199 icmp6_redirect_input(struct mbuf *m, int off) 2200 { 2201 struct ifnet *ifp; 2202 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 2203 struct nd_redirect *nd_rd; 2204 int icmp6len = ntohs(ip6->ip6_plen); 2205 char *lladdr = NULL; 2206 int lladdrlen = 0; 2207 u_char *redirhdr = NULL; 2208 int redirhdrlen = 0; 2209 struct rtentry *rt = NULL; 2210 int is_router; 2211 int is_onlink; 2212 struct in6_addr src6 = ip6->ip6_src; 2213 struct in6_addr redtgt6; 2214 struct in6_addr reddst6; 2215 union nd_opts ndopts; 2216 char ip6buf[INET6_ADDRSTRLEN]; 2217 2218 if (!m) 2219 return; 2220 2221 ifp = m->m_pkthdr.rcvif; 2222 2223 if (!ifp) 2224 return; 2225 2226 /* XXX if we are router, we don't update route by icmp6 redirect */ 2227 if (ip6_forwarding) 2228 goto freeit; 2229 if (!icmp6_rediraccept) 2230 goto freeit; 2231 2232 #ifndef PULLDOWN_TEST 2233 IP6_EXTHDR_CHECK(m, off, icmp6len,); 2234 nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off); 2235 #else 2236 IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len); 2237 if (nd_rd == NULL) { 2238 icmp6stat.icp6s_tooshort++; 2239 return; 2240 } 2241 #endif 2242 redtgt6 = nd_rd->nd_rd_target; 2243 reddst6 = nd_rd->nd_rd_dst; 2244 2245 if (in6_setscope(&redtgt6, m->m_pkthdr.rcvif, NULL) || 2246 in6_setscope(&reddst6, m->m_pkthdr.rcvif, NULL)) { 2247 goto freeit; 2248 } 2249 2250 /* validation */ 2251 if (!IN6_IS_ADDR_LINKLOCAL(&src6)) { 2252 nd6log((LOG_ERR, 2253 "ICMP6 redirect sent from %s rejected; " 2254 "must be from linklocal\n", 2255 ip6_sprintf(ip6buf, &src6))); 2256 goto bad; 2257 } 2258 if (ip6->ip6_hlim != 255) { 2259 nd6log((LOG_ERR, 2260 "ICMP6 redirect sent from %s rejected; " 2261 "hlim=%d (must be 255)\n", 2262 ip6_sprintf(ip6buf, &src6), ip6->ip6_hlim)); 2263 goto bad; 2264 } 2265 { 2266 /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */ 2267 struct sockaddr_in6 sin6; 2268 struct in6_addr *gw6; 2269 2270 bzero(&sin6, sizeof(sin6)); 2271 sin6.sin6_family = AF_INET6; 2272 sin6.sin6_len = sizeof(struct sockaddr_in6); 2273 bcopy(&reddst6, &sin6.sin6_addr, sizeof(reddst6)); 2274 rt = rtalloc1((struct sockaddr *)&sin6, 0, 0UL); 2275 if (rt) { 2276 if (rt->rt_gateway == NULL || 2277 rt->rt_gateway->sa_family != AF_INET6) { 2278 nd6log((LOG_ERR, 2279 "ICMP6 redirect rejected; no route " 2280 "with inet6 gateway found for redirect dst: %s\n", 2281 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2282 RTFREE_LOCKED(rt); 2283 goto bad; 2284 } 2285 2286 gw6 = &(((struct sockaddr_in6 *)rt->rt_gateway)->sin6_addr); 2287 if (bcmp(&src6, gw6, sizeof(struct in6_addr)) != 0) { 2288 nd6log((LOG_ERR, 2289 "ICMP6 redirect rejected; " 2290 "not equal to gw-for-src=%s (must be same): " 2291 "%s\n", 2292 ip6_sprintf(ip6buf, gw6), 2293 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2294 RTFREE_LOCKED(rt); 2295 goto bad; 2296 } 2297 } else { 2298 nd6log((LOG_ERR, 2299 "ICMP6 redirect rejected; " 2300 "no route found for redirect dst: %s\n", 2301 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2302 goto bad; 2303 } 2304 RTFREE_LOCKED(rt); 2305 rt = NULL; 2306 } 2307 if (IN6_IS_ADDR_MULTICAST(&reddst6)) { 2308 nd6log((LOG_ERR, 2309 "ICMP6 redirect rejected; " 2310 "redirect dst must be unicast: %s\n", 2311 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2312 goto bad; 2313 } 2314 2315 is_router = is_onlink = 0; 2316 if (IN6_IS_ADDR_LINKLOCAL(&redtgt6)) 2317 is_router = 1; /* router case */ 2318 if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0) 2319 is_onlink = 1; /* on-link destination case */ 2320 if (!is_router && !is_onlink) { 2321 nd6log((LOG_ERR, 2322 "ICMP6 redirect rejected; " 2323 "neither router case nor onlink case: %s\n", 2324 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2325 goto bad; 2326 } 2327 /* validation passed */ 2328 2329 icmp6len -= sizeof(*nd_rd); 2330 nd6_option_init(nd_rd + 1, icmp6len, &ndopts); 2331 if (nd6_options(&ndopts) < 0) { 2332 nd6log((LOG_INFO, "icmp6_redirect_input: " 2333 "invalid ND option, rejected: %s\n", 2334 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2335 /* nd6_options have incremented stats */ 2336 goto freeit; 2337 } 2338 2339 if (ndopts.nd_opts_tgt_lladdr) { 2340 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 2341 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 2342 } 2343 2344 if (ndopts.nd_opts_rh) { 2345 redirhdrlen = ndopts.nd_opts_rh->nd_opt_rh_len; 2346 redirhdr = (u_char *)(ndopts.nd_opts_rh + 1); /* xxx */ 2347 } 2348 2349 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 2350 nd6log((LOG_INFO, 2351 "icmp6_redirect_input: lladdrlen mismatch for %s " 2352 "(if %d, icmp6 packet %d): %s\n", 2353 ip6_sprintf(ip6buf, &redtgt6), 2354 ifp->if_addrlen, lladdrlen - 2, 2355 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2356 goto bad; 2357 } 2358 2359 /* RFC 2461 8.3 */ 2360 nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT, 2361 is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER); 2362 2363 if (!is_onlink) { /* better router case. perform rtredirect. */ 2364 /* perform rtredirect */ 2365 struct sockaddr_in6 sdst; 2366 struct sockaddr_in6 sgw; 2367 struct sockaddr_in6 ssrc; 2368 2369 bzero(&sdst, sizeof(sdst)); 2370 bzero(&sgw, sizeof(sgw)); 2371 bzero(&ssrc, sizeof(ssrc)); 2372 sdst.sin6_family = sgw.sin6_family = ssrc.sin6_family = AF_INET6; 2373 sdst.sin6_len = sgw.sin6_len = ssrc.sin6_len = 2374 sizeof(struct sockaddr_in6); 2375 bcopy(&redtgt6, &sgw.sin6_addr, sizeof(struct in6_addr)); 2376 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr)); 2377 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr)); 2378 rtredirect((struct sockaddr *)&sdst, (struct sockaddr *)&sgw, 2379 (struct sockaddr *)NULL, RTF_GATEWAY | RTF_HOST, 2380 (struct sockaddr *)&ssrc); 2381 } 2382 /* finally update cached route in each socket via pfctlinput */ 2383 { 2384 struct sockaddr_in6 sdst; 2385 2386 bzero(&sdst, sizeof(sdst)); 2387 sdst.sin6_family = AF_INET6; 2388 sdst.sin6_len = sizeof(struct sockaddr_in6); 2389 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr)); 2390 pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst); 2391 #ifdef IPSEC 2392 key_sa_routechange((struct sockaddr *)&sdst); 2393 #endif /* IPSEC */ 2394 } 2395 2396 freeit: 2397 m_freem(m); 2398 return; 2399 2400 bad: 2401 icmp6stat.icp6s_badredirect++; 2402 m_freem(m); 2403 } 2404 2405 void 2406 icmp6_redirect_output(struct mbuf *m0, struct rtentry *rt) 2407 { 2408 struct ifnet *ifp; /* my outgoing interface */ 2409 struct in6_addr *ifp_ll6; 2410 struct in6_addr *router_ll6; 2411 struct ip6_hdr *sip6; /* m0 as struct ip6_hdr */ 2412 struct mbuf *m = NULL; /* newly allocated one */ 2413 struct ip6_hdr *ip6; /* m as struct ip6_hdr */ 2414 struct nd_redirect *nd_rd; 2415 size_t maxlen; 2416 u_char *p; 2417 struct ifnet *outif = NULL; 2418 struct sockaddr_in6 src_sa; 2419 2420 icmp6_errcount(&icmp6stat.icp6s_outerrhist, ND_REDIRECT, 0); 2421 2422 /* if we are not router, we don't send icmp6 redirect */ 2423 if (!ip6_forwarding) 2424 goto fail; 2425 2426 /* sanity check */ 2427 if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp)) 2428 goto fail; 2429 2430 /* 2431 * Address check: 2432 * the source address must identify a neighbor, and 2433 * the destination address must not be a multicast address 2434 * [RFC 2461, sec 8.2] 2435 */ 2436 sip6 = mtod(m0, struct ip6_hdr *); 2437 bzero(&src_sa, sizeof(src_sa)); 2438 src_sa.sin6_family = AF_INET6; 2439 src_sa.sin6_len = sizeof(src_sa); 2440 src_sa.sin6_addr = sip6->ip6_src; 2441 if (nd6_is_addr_neighbor(&src_sa, ifp) == 0) 2442 goto fail; 2443 if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst)) 2444 goto fail; /* what should we do here? */ 2445 2446 /* rate limit */ 2447 if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0)) 2448 goto fail; 2449 2450 /* 2451 * Since we are going to append up to 1280 bytes (= IPV6_MMTU), 2452 * we almost always ask for an mbuf cluster for simplicity. 2453 * (MHLEN < IPV6_MMTU is almost always true) 2454 */ 2455 #if IPV6_MMTU >= MCLBYTES 2456 # error assumption failed about IPV6_MMTU and MCLBYTES 2457 #endif 2458 MGETHDR(m, M_DONTWAIT, MT_HEADER); 2459 if (m && IPV6_MMTU >= MHLEN) 2460 MCLGET(m, M_DONTWAIT); 2461 if (!m) 2462 goto fail; 2463 m->m_pkthdr.rcvif = NULL; 2464 m->m_len = 0; 2465 maxlen = M_TRAILINGSPACE(m); 2466 maxlen = min(IPV6_MMTU, maxlen); 2467 /* just for safety */ 2468 if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) + 2469 ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) { 2470 goto fail; 2471 } 2472 2473 { 2474 /* get ip6 linklocal address for ifp(my outgoing interface). */ 2475 struct in6_ifaddr *ia; 2476 if ((ia = in6ifa_ifpforlinklocal(ifp, 2477 IN6_IFF_NOTREADY| 2478 IN6_IFF_ANYCAST)) == NULL) 2479 goto fail; 2480 ifp_ll6 = &ia->ia_addr.sin6_addr; 2481 } 2482 2483 /* get ip6 linklocal address for the router. */ 2484 if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) { 2485 struct sockaddr_in6 *sin6; 2486 sin6 = (struct sockaddr_in6 *)rt->rt_gateway; 2487 router_ll6 = &sin6->sin6_addr; 2488 if (!IN6_IS_ADDR_LINKLOCAL(router_ll6)) 2489 router_ll6 = (struct in6_addr *)NULL; 2490 } else 2491 router_ll6 = (struct in6_addr *)NULL; 2492 2493 /* ip6 */ 2494 ip6 = mtod(m, struct ip6_hdr *); 2495 ip6->ip6_flow = 0; 2496 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2497 ip6->ip6_vfc |= IPV6_VERSION; 2498 /* ip6->ip6_plen will be set later */ 2499 ip6->ip6_nxt = IPPROTO_ICMPV6; 2500 ip6->ip6_hlim = 255; 2501 /* ip6->ip6_src must be linklocal addr for my outgoing if. */ 2502 bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr)); 2503 bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr)); 2504 2505 /* ND Redirect */ 2506 nd_rd = (struct nd_redirect *)(ip6 + 1); 2507 nd_rd->nd_rd_type = ND_REDIRECT; 2508 nd_rd->nd_rd_code = 0; 2509 nd_rd->nd_rd_reserved = 0; 2510 if (rt->rt_flags & RTF_GATEWAY) { 2511 /* 2512 * nd_rd->nd_rd_target must be a link-local address in 2513 * better router cases. 2514 */ 2515 if (!router_ll6) 2516 goto fail; 2517 bcopy(router_ll6, &nd_rd->nd_rd_target, 2518 sizeof(nd_rd->nd_rd_target)); 2519 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2520 sizeof(nd_rd->nd_rd_dst)); 2521 } else { 2522 /* make sure redtgt == reddst */ 2523 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target, 2524 sizeof(nd_rd->nd_rd_target)); 2525 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2526 sizeof(nd_rd->nd_rd_dst)); 2527 } 2528 2529 p = (u_char *)(nd_rd + 1); 2530 2531 if (!router_ll6) 2532 goto nolladdropt; 2533 2534 { 2535 /* target lladdr option */ 2536 struct rtentry *rt_router = NULL; 2537 int len; 2538 struct sockaddr_dl *sdl; 2539 struct nd_opt_hdr *nd_opt; 2540 char *lladdr; 2541 2542 rt_router = nd6_lookup(router_ll6, 0, ifp); 2543 if (!rt_router) 2544 goto nolladdropt; 2545 len = sizeof(*nd_opt) + ifp->if_addrlen; 2546 len = (len + 7) & ~7; /* round by 8 */ 2547 /* safety check */ 2548 if (len + (p - (u_char *)ip6) > maxlen) 2549 goto nolladdropt; 2550 if (!(rt_router->rt_flags & RTF_GATEWAY) && 2551 (rt_router->rt_flags & RTF_LLINFO) && 2552 (rt_router->rt_gateway->sa_family == AF_LINK) && 2553 (sdl = (struct sockaddr_dl *)rt_router->rt_gateway) && 2554 sdl->sdl_alen) { 2555 nd_opt = (struct nd_opt_hdr *)p; 2556 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 2557 nd_opt->nd_opt_len = len >> 3; 2558 lladdr = (char *)(nd_opt + 1); 2559 bcopy(LLADDR(sdl), lladdr, ifp->if_addrlen); 2560 p += len; 2561 } 2562 } 2563 nolladdropt:; 2564 2565 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2566 2567 /* just to be safe */ 2568 #ifdef M_DECRYPTED /*not openbsd*/ 2569 if (m0->m_flags & M_DECRYPTED) 2570 goto noredhdropt; 2571 #endif 2572 if (p - (u_char *)ip6 > maxlen) 2573 goto noredhdropt; 2574 2575 { 2576 /* redirected header option */ 2577 int len; 2578 struct nd_opt_rd_hdr *nd_opt_rh; 2579 2580 /* 2581 * compute the maximum size for icmp6 redirect header option. 2582 * XXX room for auth header? 2583 */ 2584 len = maxlen - (p - (u_char *)ip6); 2585 len &= ~7; 2586 2587 /* This is just for simplicity. */ 2588 if (m0->m_pkthdr.len != m0->m_len) { 2589 if (m0->m_next) { 2590 m_freem(m0->m_next); 2591 m0->m_next = NULL; 2592 } 2593 m0->m_pkthdr.len = m0->m_len; 2594 } 2595 2596 /* 2597 * Redirected header option spec (RFC2461 4.6.3) talks nothing 2598 * about padding/truncate rule for the original IP packet. 2599 * From the discussion on IPv6imp in Feb 1999, 2600 * the consensus was: 2601 * - "attach as much as possible" is the goal 2602 * - pad if not aligned (original size can be guessed by 2603 * original ip6 header) 2604 * Following code adds the padding if it is simple enough, 2605 * and truncates if not. 2606 */ 2607 if (m0->m_next || m0->m_pkthdr.len != m0->m_len) 2608 panic("assumption failed in %s:%d", __FILE__, 2609 __LINE__); 2610 2611 if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) { 2612 /* not enough room, truncate */ 2613 m0->m_pkthdr.len = m0->m_len = len - 2614 sizeof(*nd_opt_rh); 2615 } else { 2616 /* enough room, pad or truncate */ 2617 size_t extra; 2618 2619 extra = m0->m_pkthdr.len % 8; 2620 if (extra) { 2621 /* pad if easy enough, truncate if not */ 2622 if (8 - extra <= M_TRAILINGSPACE(m0)) { 2623 /* pad */ 2624 m0->m_len += (8 - extra); 2625 m0->m_pkthdr.len += (8 - extra); 2626 } else { 2627 /* truncate */ 2628 m0->m_pkthdr.len -= extra; 2629 m0->m_len -= extra; 2630 } 2631 } 2632 len = m0->m_pkthdr.len + sizeof(*nd_opt_rh); 2633 m0->m_pkthdr.len = m0->m_len = len - 2634 sizeof(*nd_opt_rh); 2635 } 2636 2637 nd_opt_rh = (struct nd_opt_rd_hdr *)p; 2638 bzero(nd_opt_rh, sizeof(*nd_opt_rh)); 2639 nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER; 2640 nd_opt_rh->nd_opt_rh_len = len >> 3; 2641 p += sizeof(*nd_opt_rh); 2642 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2643 2644 /* connect m0 to m */ 2645 m_tag_delete_chain(m0, NULL); 2646 m0->m_flags &= ~M_PKTHDR; 2647 m->m_next = m0; 2648 m->m_pkthdr.len = m->m_len + m0->m_len; 2649 m0 = NULL; 2650 } 2651 noredhdropt:; 2652 if (m0) { 2653 m_freem(m0); 2654 m0 = NULL; 2655 } 2656 2657 /* XXX: clear embedded link IDs in the inner header */ 2658 in6_clearscope(&sip6->ip6_src); 2659 in6_clearscope(&sip6->ip6_dst); 2660 in6_clearscope(&nd_rd->nd_rd_target); 2661 in6_clearscope(&nd_rd->nd_rd_dst); 2662 2663 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr)); 2664 2665 nd_rd->nd_rd_cksum = 0; 2666 nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2667 sizeof(*ip6), ntohs(ip6->ip6_plen)); 2668 2669 /* send the packet to outside... */ 2670 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2671 if (outif) { 2672 icmp6_ifstat_inc(outif, ifs6_out_msg); 2673 icmp6_ifstat_inc(outif, ifs6_out_redirect); 2674 } 2675 icmp6stat.icp6s_outhist[ND_REDIRECT]++; 2676 2677 return; 2678 2679 fail: 2680 if (m) 2681 m_freem(m); 2682 if (m0) 2683 m_freem(m0); 2684 } 2685 2686 /* 2687 * ICMPv6 socket option processing. 2688 */ 2689 int 2690 icmp6_ctloutput(struct socket *so, struct sockopt *sopt) 2691 { 2692 int error = 0; 2693 int optlen; 2694 struct inpcb *inp = sotoinpcb(so); 2695 int level, op, optname; 2696 2697 if (sopt) { 2698 level = sopt->sopt_level; 2699 op = sopt->sopt_dir; 2700 optname = sopt->sopt_name; 2701 optlen = sopt->sopt_valsize; 2702 } else 2703 level = op = optname = optlen = 0; 2704 2705 if (level != IPPROTO_ICMPV6) { 2706 return EINVAL; 2707 } 2708 2709 switch (op) { 2710 case PRCO_SETOPT: 2711 switch (optname) { 2712 case ICMP6_FILTER: 2713 { 2714 struct icmp6_filter *p; 2715 2716 if (optlen != sizeof(*p)) { 2717 error = EMSGSIZE; 2718 break; 2719 } 2720 if (inp->in6p_icmp6filt == NULL) { 2721 error = EINVAL; 2722 break; 2723 } 2724 error = sooptcopyin(sopt, inp->in6p_icmp6filt, optlen, 2725 optlen); 2726 break; 2727 } 2728 2729 default: 2730 error = ENOPROTOOPT; 2731 break; 2732 } 2733 break; 2734 2735 case PRCO_GETOPT: 2736 switch (optname) { 2737 case ICMP6_FILTER: 2738 { 2739 if (inp->in6p_icmp6filt == NULL) { 2740 error = EINVAL; 2741 break; 2742 } 2743 error = sooptcopyout(sopt, inp->in6p_icmp6filt, 2744 sizeof(struct icmp6_filter)); 2745 break; 2746 } 2747 2748 default: 2749 error = ENOPROTOOPT; 2750 break; 2751 } 2752 break; 2753 } 2754 2755 return (error); 2756 } 2757 2758 /* 2759 * Perform rate limit check. 2760 * Returns 0 if it is okay to send the icmp6 packet. 2761 * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate 2762 * limitation. 2763 * 2764 * XXX per-destination/type check necessary? 2765 * 2766 * dst - not used at this moment 2767 * type - not used at this moment 2768 * code - not used at this moment 2769 */ 2770 static int 2771 icmp6_ratelimit(const struct in6_addr *dst, const int type, 2772 const int code) 2773 { 2774 int ret; 2775 2776 ret = 0; /* okay to send */ 2777 2778 /* PPS limit */ 2779 if (!ppsratecheck(&icmp6errppslim_last, &icmp6errpps_count, 2780 icmp6errppslim)) { 2781 /* The packet is subject to rate limit */ 2782 ret++; 2783 } 2784 2785 return ret; 2786 } 2787