Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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sys/netinet6/icmp6.c
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1 /* $FreeBSD$ */ 2 /* $KAME: icmp6.c,v 1.211 2001/04/04 05:56:20 itojun Exp $ */ 3 4 /*- 5 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the project nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 /*- 34 * Copyright (c) 1982, 1986, 1988, 1993 35 * The Regents of the University of California. All rights reserved. 36 * 37 * Redistribution and use in source and binary forms, with or without 38 * modification, are permitted provided that the following conditions 39 * are met: 40 * 1. Redistributions of source code must retain the above copyright 41 * notice, this list of conditions and the following disclaimer. 42 * 2. Redistributions in binary form must reproduce the above copyright 43 * notice, this list of conditions and the following disclaimer in the 44 * documentation and/or other materials provided with the distribution. 45 * 4. Neither the name of the University nor the names of its contributors 46 * may be used to endorse or promote products derived from this software 47 * without specific prior written permission. 48 * 49 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 50 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 51 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 52 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 53 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 54 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 55 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 56 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 57 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 58 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 59 * SUCH DAMAGE. 60 * 61 * @(#)ip_icmp.c 8.2 (Berkeley) 1/4/94 62 */ 63 64 #include "opt_inet.h" 65 #include "opt_inet6.h" 66 #include "opt_ipsec.h" 67 68 #include <sys/param.h> 69 #include <sys/domain.h> 70 #include <sys/kernel.h> 71 #include <sys/lock.h> 72 #include <sys/malloc.h> 73 #include <sys/mbuf.h> 74 #include <sys/protosw.h> 75 #include <sys/signalvar.h> 76 #include <sys/socket.h> 77 #include <sys/socketvar.h> 78 #include <sys/sx.h> 79 #include <sys/syslog.h> 80 #include <sys/systm.h> 81 #include <sys/time.h> 82 83 #include <net/if.h> 84 #include <net/if_dl.h> 85 #include <net/if_types.h> 86 #include <net/route.h> 87 88 #include <netinet/in.h> 89 #include <netinet/in_pcb.h> 90 #include <netinet/in_var.h> 91 #include <netinet/ip6.h> 92 #include <netinet/icmp6.h> 93 #include <netinet/tcp_var.h> 94 #include <netinet6/in6_ifattach.h> 95 #include <netinet6/in6_pcb.h> 96 #include <netinet6/ip6protosw.h> 97 #include <netinet6/ip6_var.h> 98 #include <netinet6/scope6_var.h> 99 #include <netinet6/mld6_var.h> 100 #include <netinet6/nd6.h> 101 102 #ifdef IPSEC 103 #include <netipsec/ipsec.h> 104 #include <netipsec/key.h> 105 #endif 106 107 extern struct domain inet6domain; 108 109 struct icmp6stat icmp6stat; 110 111 extern struct inpcbinfo ripcbinfo; 112 extern struct inpcbhead ripcb; 113 extern int icmp6errppslim; 114 static int icmp6errpps_count = 0; 115 static struct timeval icmp6errppslim_last; 116 extern int icmp6_nodeinfo; 117 118 static void icmp6_errcount __P((struct icmp6errstat *, int, int)); 119 static int icmp6_rip6_input __P((struct mbuf **, int)); 120 static int icmp6_ratelimit __P((const struct in6_addr *, const int, const int)); 121 static const char *icmp6_redirect_diag __P((struct in6_addr *, 122 struct in6_addr *, struct in6_addr *)); 123 static struct mbuf *ni6_input __P((struct mbuf *, int)); 124 static struct mbuf *ni6_nametodns __P((const char *, int, int)); 125 static int ni6_dnsmatch __P((const char *, int, const char *, int)); 126 static int ni6_addrs __P((struct icmp6_nodeinfo *, struct mbuf *, 127 struct ifnet **, struct in6_addr *)); 128 static int ni6_store_addrs __P((struct icmp6_nodeinfo *, struct icmp6_nodeinfo *, 129 struct ifnet *, int)); 130 static int icmp6_notify_error __P((struct mbuf **, int, int, int)); 131 132 133 void 134 icmp6_init(void) 135 { 136 137 mld6_init(); 138 } 139 140 static void 141 icmp6_errcount(struct icmp6errstat *stat, int type, int code) 142 { 143 switch (type) { 144 case ICMP6_DST_UNREACH: 145 switch (code) { 146 case ICMP6_DST_UNREACH_NOROUTE: 147 stat->icp6errs_dst_unreach_noroute++; 148 return; 149 case ICMP6_DST_UNREACH_ADMIN: 150 stat->icp6errs_dst_unreach_admin++; 151 return; 152 case ICMP6_DST_UNREACH_BEYONDSCOPE: 153 stat->icp6errs_dst_unreach_beyondscope++; 154 return; 155 case ICMP6_DST_UNREACH_ADDR: 156 stat->icp6errs_dst_unreach_addr++; 157 return; 158 case ICMP6_DST_UNREACH_NOPORT: 159 stat->icp6errs_dst_unreach_noport++; 160 return; 161 } 162 break; 163 case ICMP6_PACKET_TOO_BIG: 164 stat->icp6errs_packet_too_big++; 165 return; 166 case ICMP6_TIME_EXCEEDED: 167 switch (code) { 168 case ICMP6_TIME_EXCEED_TRANSIT: 169 stat->icp6errs_time_exceed_transit++; 170 return; 171 case ICMP6_TIME_EXCEED_REASSEMBLY: 172 stat->icp6errs_time_exceed_reassembly++; 173 return; 174 } 175 break; 176 case ICMP6_PARAM_PROB: 177 switch (code) { 178 case ICMP6_PARAMPROB_HEADER: 179 stat->icp6errs_paramprob_header++; 180 return; 181 case ICMP6_PARAMPROB_NEXTHEADER: 182 stat->icp6errs_paramprob_nextheader++; 183 return; 184 case ICMP6_PARAMPROB_OPTION: 185 stat->icp6errs_paramprob_option++; 186 return; 187 } 188 break; 189 case ND_REDIRECT: 190 stat->icp6errs_redirect++; 191 return; 192 } 193 stat->icp6errs_unknown++; 194 } 195 196 /* 197 * A wrapper function for icmp6_error() necessary when the erroneous packet 198 * may not contain enough scope zone information. 199 */ 200 void 201 icmp6_error2(struct mbuf *m, int type, int code, int param, 202 struct ifnet *ifp) 203 { 204 struct ip6_hdr *ip6; 205 206 if (ifp == NULL) 207 return; 208 209 #ifndef PULLDOWN_TEST 210 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), ); 211 #else 212 if (m->m_len < sizeof(struct ip6_hdr)) { 213 m = m_pullup(m, sizeof(struct ip6_hdr)); 214 if (m == NULL) 215 return; 216 } 217 #endif 218 219 ip6 = mtod(m, struct ip6_hdr *); 220 221 if (in6_setscope(&ip6->ip6_src, ifp, NULL) != 0) 222 return; 223 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0) 224 return; 225 226 icmp6_error(m, type, code, param); 227 } 228 229 /* 230 * Generate an error packet of type error in response to bad IP6 packet. 231 */ 232 void 233 icmp6_error(struct mbuf *m, int type, int code, int param) 234 { 235 struct ip6_hdr *oip6, *nip6; 236 struct icmp6_hdr *icmp6; 237 u_int preplen; 238 int off; 239 int nxt; 240 241 icmp6stat.icp6s_error++; 242 243 /* count per-type-code statistics */ 244 icmp6_errcount(&icmp6stat.icp6s_outerrhist, type, code); 245 246 #ifdef M_DECRYPTED /*not openbsd*/ 247 if (m->m_flags & M_DECRYPTED) { 248 icmp6stat.icp6s_canterror++; 249 goto freeit; 250 } 251 #endif 252 253 #ifndef PULLDOWN_TEST 254 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), ); 255 #else 256 if (m->m_len < sizeof(struct ip6_hdr)) { 257 m = m_pullup(m, sizeof(struct ip6_hdr)); 258 if (m == NULL) 259 return; 260 } 261 #endif 262 oip6 = mtod(m, struct ip6_hdr *); 263 264 /* 265 * If the destination address of the erroneous packet is a multicast 266 * address, or the packet was sent using link-layer multicast, 267 * we should basically suppress sending an error (RFC 2463, Section 268 * 2.4). 269 * We have two exceptions (the item e.2 in that section): 270 * - the Pakcet Too Big message can be sent for path MTU discovery. 271 * - the Parameter Problem Message that can be allowed an icmp6 error 272 * in the option type field. This check has been done in 273 * ip6_unknown_opt(), so we can just check the type and code. 274 */ 275 if ((m->m_flags & (M_BCAST|M_MCAST) || 276 IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) && 277 (type != ICMP6_PACKET_TOO_BIG && 278 (type != ICMP6_PARAM_PROB || 279 code != ICMP6_PARAMPROB_OPTION))) 280 goto freeit; 281 282 /* 283 * RFC 2463, 2.4 (e.5): source address check. 284 * XXX: the case of anycast source? 285 */ 286 if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) || 287 IN6_IS_ADDR_MULTICAST(&oip6->ip6_src)) 288 goto freeit; 289 290 /* 291 * If we are about to send ICMPv6 against ICMPv6 error/redirect, 292 * don't do it. 293 */ 294 nxt = -1; 295 off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt); 296 if (off >= 0 && nxt == IPPROTO_ICMPV6) { 297 struct icmp6_hdr *icp; 298 299 #ifndef PULLDOWN_TEST 300 IP6_EXTHDR_CHECK(m, 0, off + sizeof(struct icmp6_hdr), ); 301 icp = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 302 #else 303 IP6_EXTHDR_GET(icp, struct icmp6_hdr *, m, off, 304 sizeof(*icp)); 305 if (icp == NULL) { 306 icmp6stat.icp6s_tooshort++; 307 return; 308 } 309 #endif 310 if (icp->icmp6_type < ICMP6_ECHO_REQUEST || 311 icp->icmp6_type == ND_REDIRECT) { 312 /* 313 * ICMPv6 error 314 * Special case: for redirect (which is 315 * informational) we must not send icmp6 error. 316 */ 317 icmp6stat.icp6s_canterror++; 318 goto freeit; 319 } else { 320 /* ICMPv6 informational - send the error */ 321 } 322 } else { 323 /* non-ICMPv6 - send the error */ 324 } 325 326 oip6 = mtod(m, struct ip6_hdr *); /* adjust pointer */ 327 328 /* Finally, do rate limitation check. */ 329 if (icmp6_ratelimit(&oip6->ip6_src, type, code)) { 330 icmp6stat.icp6s_toofreq++; 331 goto freeit; 332 } 333 334 /* 335 * OK, ICMP6 can be generated. 336 */ 337 338 if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN) 339 m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len); 340 341 preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 342 M_PREPEND(m, preplen, M_DONTWAIT); 343 if (m && m->m_len < preplen) 344 m = m_pullup(m, preplen); 345 if (m == NULL) { 346 nd6log((LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__)); 347 return; 348 } 349 350 nip6 = mtod(m, struct ip6_hdr *); 351 nip6->ip6_src = oip6->ip6_src; 352 nip6->ip6_dst = oip6->ip6_dst; 353 354 in6_clearscope(&oip6->ip6_src); 355 in6_clearscope(&oip6->ip6_dst); 356 357 icmp6 = (struct icmp6_hdr *)(nip6 + 1); 358 icmp6->icmp6_type = type; 359 icmp6->icmp6_code = code; 360 icmp6->icmp6_pptr = htonl((u_int32_t)param); 361 362 /* 363 * icmp6_reflect() is designed to be in the input path. 364 * icmp6_error() can be called from both input and output path, 365 * and if we are in output path rcvif could contain bogus value. 366 * clear m->m_pkthdr.rcvif for safety, we should have enough scope 367 * information in ip header (nip6). 368 */ 369 m->m_pkthdr.rcvif = NULL; 370 371 icmp6stat.icp6s_outhist[type]++; 372 icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */ 373 374 return; 375 376 freeit: 377 /* 378 * If we can't tell whether or not we can generate ICMP6, free it. 379 */ 380 m_freem(m); 381 } 382 383 /* 384 * Process a received ICMP6 message. 385 */ 386 int 387 icmp6_input(struct mbuf **mp, int *offp, int proto) 388 { 389 struct mbuf *m = *mp, *n; 390 struct ip6_hdr *ip6, *nip6; 391 struct icmp6_hdr *icmp6, *nicmp6; 392 int off = *offp; 393 int icmp6len = m->m_pkthdr.len - *offp; 394 int code, sum, noff; 395 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 396 397 #ifndef PULLDOWN_TEST 398 IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_hdr), IPPROTO_DONE); 399 /* m might change if M_LOOP. So, call mtod after this */ 400 #endif 401 402 /* 403 * Locate icmp6 structure in mbuf, and check 404 * that not corrupted and of at least minimum length 405 */ 406 407 ip6 = mtod(m, struct ip6_hdr *); 408 if (icmp6len < sizeof(struct icmp6_hdr)) { 409 icmp6stat.icp6s_tooshort++; 410 goto freeit; 411 } 412 413 /* 414 * calculate the checksum 415 */ 416 #ifndef PULLDOWN_TEST 417 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off); 418 #else 419 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6)); 420 if (icmp6 == NULL) { 421 icmp6stat.icp6s_tooshort++; 422 return IPPROTO_DONE; 423 } 424 #endif 425 code = icmp6->icmp6_code; 426 427 if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) { 428 nd6log((LOG_ERR, 429 "ICMP6 checksum error(%d|%x) %s\n", 430 icmp6->icmp6_type, sum, 431 ip6_sprintf(ip6bufs, &ip6->ip6_src))); 432 icmp6stat.icp6s_checksum++; 433 goto freeit; 434 } 435 436 if (faithprefix_p != NULL && (*faithprefix_p)(&ip6->ip6_dst)) { 437 /* 438 * Deliver very specific ICMP6 type only. 439 * This is important to deliver TOOBIG. Otherwise PMTUD 440 * will not work. 441 */ 442 switch (icmp6->icmp6_type) { 443 case ICMP6_DST_UNREACH: 444 case ICMP6_PACKET_TOO_BIG: 445 case ICMP6_TIME_EXCEEDED: 446 break; 447 default: 448 goto freeit; 449 } 450 } 451 452 icmp6stat.icp6s_inhist[icmp6->icmp6_type]++; 453 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_msg); 454 if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK) 455 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_error); 456 457 switch (icmp6->icmp6_type) { 458 case ICMP6_DST_UNREACH: 459 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_dstunreach); 460 switch (code) { 461 case ICMP6_DST_UNREACH_NOROUTE: 462 code = PRC_UNREACH_NET; 463 break; 464 case ICMP6_DST_UNREACH_ADMIN: 465 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_adminprohib); 466 code = PRC_UNREACH_PROTOCOL; /* is this a good code? */ 467 break; 468 case ICMP6_DST_UNREACH_ADDR: 469 code = PRC_HOSTDEAD; 470 break; 471 case ICMP6_DST_UNREACH_BEYONDSCOPE: 472 /* I mean "source address was incorrect." */ 473 code = PRC_PARAMPROB; 474 break; 475 case ICMP6_DST_UNREACH_NOPORT: 476 code = PRC_UNREACH_PORT; 477 break; 478 default: 479 goto badcode; 480 } 481 goto deliver; 482 break; 483 484 case ICMP6_PACKET_TOO_BIG: 485 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_pkttoobig); 486 487 /* validation is made in icmp6_mtudisc_update */ 488 489 code = PRC_MSGSIZE; 490 491 /* 492 * Updating the path MTU will be done after examining 493 * intermediate extension headers. 494 */ 495 goto deliver; 496 break; 497 498 case ICMP6_TIME_EXCEEDED: 499 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_timeexceed); 500 switch (code) { 501 case ICMP6_TIME_EXCEED_TRANSIT: 502 code = PRC_TIMXCEED_INTRANS; 503 break; 504 case ICMP6_TIME_EXCEED_REASSEMBLY: 505 code = PRC_TIMXCEED_REASS; 506 break; 507 default: 508 goto badcode; 509 } 510 goto deliver; 511 break; 512 513 case ICMP6_PARAM_PROB: 514 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_paramprob); 515 switch (code) { 516 case ICMP6_PARAMPROB_NEXTHEADER: 517 code = PRC_UNREACH_PROTOCOL; 518 break; 519 case ICMP6_PARAMPROB_HEADER: 520 case ICMP6_PARAMPROB_OPTION: 521 code = PRC_PARAMPROB; 522 break; 523 default: 524 goto badcode; 525 } 526 goto deliver; 527 break; 528 529 case ICMP6_ECHO_REQUEST: 530 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_echo); 531 if (code != 0) 532 goto badcode; 533 if ((n = m_copy(m, 0, M_COPYALL)) == NULL) { 534 /* Give up remote */ 535 break; 536 } 537 if ((n->m_flags & M_EXT) != 0 538 || n->m_len < off + sizeof(struct icmp6_hdr)) { 539 struct mbuf *n0 = n; 540 const int maxlen = sizeof(*nip6) + sizeof(*nicmp6); 541 int n0len; 542 543 MGETHDR(n, M_DONTWAIT, n0->m_type); 544 n0len = n0->m_pkthdr.len; /* save for use below */ 545 if (n) 546 M_MOVE_PKTHDR(n, n0); 547 if (n && maxlen >= MHLEN) { 548 MCLGET(n, M_DONTWAIT); 549 if ((n->m_flags & M_EXT) == 0) { 550 m_free(n); 551 n = NULL; 552 } 553 } 554 if (n == NULL) { 555 /* Give up remote */ 556 m_freem(n0); 557 break; 558 } 559 /* 560 * Copy IPv6 and ICMPv6 only. 561 */ 562 nip6 = mtod(n, struct ip6_hdr *); 563 bcopy(ip6, nip6, sizeof(struct ip6_hdr)); 564 nicmp6 = (struct icmp6_hdr *)(nip6 + 1); 565 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr)); 566 noff = sizeof(struct ip6_hdr); 567 /* new mbuf contains only ipv6+icmpv6 headers */ 568 n->m_len = noff + sizeof(struct icmp6_hdr); 569 /* 570 * Adjust mbuf. ip6_plen will be adjusted in 571 * ip6_output(). 572 */ 573 m_adj(n0, off + sizeof(struct icmp6_hdr)); 574 /* recalculate complete packet size */ 575 n->m_pkthdr.len = n0len + (noff - off); 576 n->m_next = n0; 577 } else { 578 nip6 = mtod(n, struct ip6_hdr *); 579 IP6_EXTHDR_GET(nicmp6, struct icmp6_hdr *, n, off, 580 sizeof(*nicmp6)); 581 noff = off; 582 } 583 nicmp6->icmp6_type = ICMP6_ECHO_REPLY; 584 nicmp6->icmp6_code = 0; 585 if (n) { 586 icmp6stat.icp6s_reflect++; 587 icmp6stat.icp6s_outhist[ICMP6_ECHO_REPLY]++; 588 icmp6_reflect(n, noff); 589 } 590 break; 591 592 case ICMP6_ECHO_REPLY: 593 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_echoreply); 594 if (code != 0) 595 goto badcode; 596 break; 597 598 case MLD_LISTENER_QUERY: 599 case MLD_LISTENER_REPORT: 600 if (icmp6len < sizeof(struct mld_hdr)) 601 goto badlen; 602 if (icmp6->icmp6_type == MLD_LISTENER_QUERY) /* XXX: ugly... */ 603 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mldquery); 604 else 605 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mldreport); 606 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 607 /* give up local */ 608 mld6_input(m, off); 609 m = NULL; 610 goto freeit; 611 } 612 mld6_input(n, off); 613 /* m stays. */ 614 break; 615 616 case MLD_LISTENER_DONE: 617 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mlddone); 618 if (icmp6len < sizeof(struct mld_hdr)) /* necessary? */ 619 goto badlen; 620 break; /* nothing to be done in kernel */ 621 622 case MLD_MTRACE_RESP: 623 case MLD_MTRACE: 624 /* XXX: these two are experimental. not officially defined. */ 625 /* XXX: per-interface statistics? */ 626 break; /* just pass it to applications */ 627 628 case ICMP6_WRUREQUEST: /* ICMP6_FQDN_QUERY */ 629 { 630 enum { WRU, FQDN } mode; 631 632 if (!icmp6_nodeinfo) 633 break; 634 635 if (icmp6len == sizeof(struct icmp6_hdr) + 4) 636 mode = WRU; 637 else if (icmp6len >= sizeof(struct icmp6_nodeinfo)) 638 mode = FQDN; 639 else 640 goto badlen; 641 642 #define hostnamelen strlen(hostname) 643 if (mode == FQDN) { 644 #ifndef PULLDOWN_TEST 645 IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_nodeinfo), 646 IPPROTO_DONE); 647 #endif 648 n = m_copy(m, 0, M_COPYALL); 649 if (n) 650 n = ni6_input(n, off); 651 /* XXX meaningless if n == NULL */ 652 noff = sizeof(struct ip6_hdr); 653 } else { 654 u_char *p; 655 int maxlen, maxhlen; 656 657 /* 658 * XXX: this combination of flags is pointless, 659 * but should we keep this for compatibility? 660 */ 661 if ((icmp6_nodeinfo & 5) != 5) 662 break; 663 664 if (code != 0) 665 goto badcode; 666 maxlen = sizeof(*nip6) + sizeof(*nicmp6) + 4; 667 if (maxlen >= MCLBYTES) { 668 /* Give up remote */ 669 break; 670 } 671 MGETHDR(n, M_DONTWAIT, m->m_type); 672 if (n && maxlen > MHLEN) { 673 MCLGET(n, M_DONTWAIT); 674 if ((n->m_flags & M_EXT) == 0) { 675 m_free(n); 676 n = NULL; 677 } 678 } 679 if (n && !m_dup_pkthdr(n, m, M_DONTWAIT)) { 680 /* 681 * Previous code did a blind M_COPY_PKTHDR 682 * and said "just for rcvif". If true, then 683 * we could tolerate the dup failing (due to 684 * the deep copy of the tag chain). For now 685 * be conservative and just fail. 686 */ 687 m_free(n); 688 n = NULL; 689 } 690 if (n == NULL) { 691 /* Give up remote */ 692 break; 693 } 694 n->m_pkthdr.rcvif = NULL; 695 n->m_len = 0; 696 maxhlen = M_TRAILINGSPACE(n) - maxlen; 697 if (maxhlen > hostnamelen) 698 maxhlen = hostnamelen; 699 /* 700 * Copy IPv6 and ICMPv6 only. 701 */ 702 nip6 = mtod(n, struct ip6_hdr *); 703 bcopy(ip6, nip6, sizeof(struct ip6_hdr)); 704 nicmp6 = (struct icmp6_hdr *)(nip6 + 1); 705 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr)); 706 p = (u_char *)(nicmp6 + 1); 707 bzero(p, 4); 708 bcopy(hostname, p + 4, maxhlen); /* meaningless TTL */ 709 noff = sizeof(struct ip6_hdr); 710 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + 711 sizeof(struct icmp6_hdr) + 4 + maxhlen; 712 nicmp6->icmp6_type = ICMP6_WRUREPLY; 713 nicmp6->icmp6_code = 0; 714 } 715 #undef hostnamelen 716 if (n) { 717 icmp6stat.icp6s_reflect++; 718 icmp6stat.icp6s_outhist[ICMP6_WRUREPLY]++; 719 icmp6_reflect(n, noff); 720 } 721 break; 722 } 723 724 case ICMP6_WRUREPLY: 725 if (code != 0) 726 goto badcode; 727 break; 728 729 case ND_ROUTER_SOLICIT: 730 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_routersolicit); 731 if (code != 0) 732 goto badcode; 733 if (icmp6len < sizeof(struct nd_router_solicit)) 734 goto badlen; 735 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 736 /* give up local */ 737 nd6_rs_input(m, off, icmp6len); 738 m = NULL; 739 goto freeit; 740 } 741 nd6_rs_input(n, off, icmp6len); 742 /* m stays. */ 743 break; 744 745 case ND_ROUTER_ADVERT: 746 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_routeradvert); 747 if (code != 0) 748 goto badcode; 749 if (icmp6len < sizeof(struct nd_router_advert)) 750 goto badlen; 751 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 752 /* give up local */ 753 nd6_ra_input(m, off, icmp6len); 754 m = NULL; 755 goto freeit; 756 } 757 nd6_ra_input(n, off, icmp6len); 758 /* m stays. */ 759 break; 760 761 case ND_NEIGHBOR_SOLICIT: 762 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_neighborsolicit); 763 if (code != 0) 764 goto badcode; 765 if (icmp6len < sizeof(struct nd_neighbor_solicit)) 766 goto badlen; 767 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 768 /* give up local */ 769 nd6_ns_input(m, off, icmp6len); 770 m = NULL; 771 goto freeit; 772 } 773 nd6_ns_input(n, off, icmp6len); 774 /* m stays. */ 775 break; 776 777 case ND_NEIGHBOR_ADVERT: 778 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_neighboradvert); 779 if (code != 0) 780 goto badcode; 781 if (icmp6len < sizeof(struct nd_neighbor_advert)) 782 goto badlen; 783 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 784 /* give up local */ 785 nd6_na_input(m, off, icmp6len); 786 m = NULL; 787 goto freeit; 788 } 789 nd6_na_input(n, off, icmp6len); 790 /* m stays. */ 791 break; 792 793 case ND_REDIRECT: 794 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_redirect); 795 if (code != 0) 796 goto badcode; 797 if (icmp6len < sizeof(struct nd_redirect)) 798 goto badlen; 799 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 800 /* give up local */ 801 icmp6_redirect_input(m, off); 802 m = NULL; 803 goto freeit; 804 } 805 icmp6_redirect_input(n, off); 806 /* m stays. */ 807 break; 808 809 case ICMP6_ROUTER_RENUMBERING: 810 if (code != ICMP6_ROUTER_RENUMBERING_COMMAND && 811 code != ICMP6_ROUTER_RENUMBERING_RESULT) 812 goto badcode; 813 if (icmp6len < sizeof(struct icmp6_router_renum)) 814 goto badlen; 815 break; 816 817 default: 818 nd6log((LOG_DEBUG, 819 "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n", 820 icmp6->icmp6_type, ip6_sprintf(ip6bufs, &ip6->ip6_src), 821 ip6_sprintf(ip6bufd, &ip6->ip6_dst), 822 m->m_pkthdr.rcvif ? m->m_pkthdr.rcvif->if_index : 0)); 823 if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) { 824 /* ICMPv6 error: MUST deliver it by spec... */ 825 code = PRC_NCMDS; 826 /* deliver */ 827 } else { 828 /* ICMPv6 informational: MUST not deliver */ 829 break; 830 } 831 deliver: 832 if (icmp6_notify_error(&m, off, icmp6len, code)) { 833 /* In this case, m should've been freed. */ 834 return (IPPROTO_DONE); 835 } 836 break; 837 838 badcode: 839 icmp6stat.icp6s_badcode++; 840 break; 841 842 badlen: 843 icmp6stat.icp6s_badlen++; 844 break; 845 } 846 847 /* deliver the packet to appropriate sockets */ 848 icmp6_rip6_input(&m, *offp); 849 850 return IPPROTO_DONE; 851 852 freeit: 853 m_freem(m); 854 return IPPROTO_DONE; 855 } 856 857 static int 858 icmp6_notify_error(struct mbuf **mp, int off, int icmp6len, int code) 859 { 860 struct mbuf *m = *mp; 861 struct icmp6_hdr *icmp6; 862 struct ip6_hdr *eip6; 863 u_int32_t notifymtu; 864 struct sockaddr_in6 icmp6src, icmp6dst; 865 866 if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) { 867 icmp6stat.icp6s_tooshort++; 868 goto freeit; 869 } 870 #ifndef PULLDOWN_TEST 871 IP6_EXTHDR_CHECK(m, off, 872 sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr), -1); 873 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 874 #else 875 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, 876 sizeof(*icmp6) + sizeof(struct ip6_hdr)); 877 if (icmp6 == NULL) { 878 icmp6stat.icp6s_tooshort++; 879 return (-1); 880 } 881 #endif 882 eip6 = (struct ip6_hdr *)(icmp6 + 1); 883 884 /* Detect the upper level protocol */ 885 { 886 void (*ctlfunc) __P((int, struct sockaddr *, void *)); 887 u_int8_t nxt = eip6->ip6_nxt; 888 int eoff = off + sizeof(struct icmp6_hdr) + 889 sizeof(struct ip6_hdr); 890 struct ip6ctlparam ip6cp; 891 struct in6_addr *finaldst = NULL; 892 int icmp6type = icmp6->icmp6_type; 893 struct ip6_frag *fh; 894 struct ip6_rthdr *rth; 895 struct ip6_rthdr0 *rth0; 896 int rthlen; 897 898 while (1) { /* XXX: should avoid infinite loop explicitly? */ 899 struct ip6_ext *eh; 900 901 switch (nxt) { 902 case IPPROTO_HOPOPTS: 903 case IPPROTO_DSTOPTS: 904 case IPPROTO_AH: 905 #ifndef PULLDOWN_TEST 906 IP6_EXTHDR_CHECK(m, 0, 907 eoff + sizeof(struct ip6_ext), -1); 908 eh = (struct ip6_ext *)(mtod(m, caddr_t) + eoff); 909 #else 910 IP6_EXTHDR_GET(eh, struct ip6_ext *, m, 911 eoff, sizeof(*eh)); 912 if (eh == NULL) { 913 icmp6stat.icp6s_tooshort++; 914 return (-1); 915 } 916 #endif 917 918 if (nxt == IPPROTO_AH) 919 eoff += (eh->ip6e_len + 2) << 2; 920 else 921 eoff += (eh->ip6e_len + 1) << 3; 922 nxt = eh->ip6e_nxt; 923 break; 924 case IPPROTO_ROUTING: 925 /* 926 * When the erroneous packet contains a 927 * routing header, we should examine the 928 * header to determine the final destination. 929 * Otherwise, we can't properly update 930 * information that depends on the final 931 * destination (e.g. path MTU). 932 */ 933 #ifndef PULLDOWN_TEST 934 IP6_EXTHDR_CHECK(m, 0, eoff + sizeof(*rth), -1); 935 rth = (struct ip6_rthdr *) 936 (mtod(m, caddr_t) + eoff); 937 #else 938 IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m, 939 eoff, sizeof(*rth)); 940 if (rth == NULL) { 941 icmp6stat.icp6s_tooshort++; 942 return (-1); 943 } 944 #endif 945 rthlen = (rth->ip6r_len + 1) << 3; 946 /* 947 * XXX: currently there is no 948 * officially defined type other 949 * than type-0. 950 * Note that if the segment left field 951 * is 0, all intermediate hops must 952 * have been passed. 953 */ 954 if (rth->ip6r_segleft && 955 rth->ip6r_type == IPV6_RTHDR_TYPE_0) { 956 int hops; 957 958 #ifndef PULLDOWN_TEST 959 IP6_EXTHDR_CHECK(m, 0, eoff + rthlen, -1); 960 rth0 = (struct ip6_rthdr0 *) 961 (mtod(m, caddr_t) + eoff); 962 #else 963 IP6_EXTHDR_GET(rth0, 964 struct ip6_rthdr0 *, m, 965 eoff, rthlen); 966 if (rth0 == NULL) { 967 icmp6stat.icp6s_tooshort++; 968 return (-1); 969 } 970 #endif 971 /* just ignore a bogus header */ 972 if ((rth0->ip6r0_len % 2) == 0 && 973 (hops = rth0->ip6r0_len/2)) 974 finaldst = (struct in6_addr *)(rth0 + 1) + (hops - 1); 975 } 976 eoff += rthlen; 977 nxt = rth->ip6r_nxt; 978 break; 979 case IPPROTO_FRAGMENT: 980 #ifndef PULLDOWN_TEST 981 IP6_EXTHDR_CHECK(m, 0, eoff + 982 sizeof(struct ip6_frag), -1); 983 fh = (struct ip6_frag *)(mtod(m, caddr_t) + 984 eoff); 985 #else 986 IP6_EXTHDR_GET(fh, struct ip6_frag *, m, 987 eoff, sizeof(*fh)); 988 if (fh == NULL) { 989 icmp6stat.icp6s_tooshort++; 990 return (-1); 991 } 992 #endif 993 /* 994 * Data after a fragment header is meaningless 995 * unless it is the first fragment, but 996 * we'll go to the notify label for path MTU 997 * discovery. 998 */ 999 if (fh->ip6f_offlg & IP6F_OFF_MASK) 1000 goto notify; 1001 1002 eoff += sizeof(struct ip6_frag); 1003 nxt = fh->ip6f_nxt; 1004 break; 1005 default: 1006 /* 1007 * This case includes ESP and the No Next 1008 * Header. In such cases going to the notify 1009 * label does not have any meaning 1010 * (i.e. ctlfunc will be NULL), but we go 1011 * anyway since we might have to update 1012 * path MTU information. 1013 */ 1014 goto notify; 1015 } 1016 } 1017 notify: 1018 #ifndef PULLDOWN_TEST 1019 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 1020 #else 1021 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, 1022 sizeof(*icmp6) + sizeof(struct ip6_hdr)); 1023 if (icmp6 == NULL) { 1024 icmp6stat.icp6s_tooshort++; 1025 return (-1); 1026 } 1027 #endif 1028 1029 /* 1030 * retrieve parameters from the inner IPv6 header, and convert 1031 * them into sockaddr structures. 1032 * XXX: there is no guarantee that the source or destination 1033 * addresses of the inner packet are in the same scope as 1034 * the addresses of the icmp packet. But there is no other 1035 * way to determine the zone. 1036 */ 1037 eip6 = (struct ip6_hdr *)(icmp6 + 1); 1038 1039 bzero(&icmp6dst, sizeof(icmp6dst)); 1040 icmp6dst.sin6_len = sizeof(struct sockaddr_in6); 1041 icmp6dst.sin6_family = AF_INET6; 1042 if (finaldst == NULL) 1043 icmp6dst.sin6_addr = eip6->ip6_dst; 1044 else 1045 icmp6dst.sin6_addr = *finaldst; 1046 if (in6_setscope(&icmp6dst.sin6_addr, m->m_pkthdr.rcvif, NULL)) 1047 goto freeit; 1048 bzero(&icmp6src, sizeof(icmp6src)); 1049 icmp6src.sin6_len = sizeof(struct sockaddr_in6); 1050 icmp6src.sin6_family = AF_INET6; 1051 icmp6src.sin6_addr = eip6->ip6_src; 1052 if (in6_setscope(&icmp6src.sin6_addr, m->m_pkthdr.rcvif, NULL)) 1053 goto freeit; 1054 icmp6src.sin6_flowinfo = 1055 (eip6->ip6_flow & IPV6_FLOWLABEL_MASK); 1056 1057 if (finaldst == NULL) 1058 finaldst = &eip6->ip6_dst; 1059 ip6cp.ip6c_m = m; 1060 ip6cp.ip6c_icmp6 = icmp6; 1061 ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1); 1062 ip6cp.ip6c_off = eoff; 1063 ip6cp.ip6c_finaldst = finaldst; 1064 ip6cp.ip6c_src = &icmp6src; 1065 ip6cp.ip6c_nxt = nxt; 1066 1067 if (icmp6type == ICMP6_PACKET_TOO_BIG) { 1068 notifymtu = ntohl(icmp6->icmp6_mtu); 1069 ip6cp.ip6c_cmdarg = (void *)¬ifymtu; 1070 icmp6_mtudisc_update(&ip6cp, 1); /*XXX*/ 1071 } 1072 1073 ctlfunc = (void (*) __P((int, struct sockaddr *, void *))) 1074 (inet6sw[ip6_protox[nxt]].pr_ctlinput); 1075 if (ctlfunc) { 1076 (void) (*ctlfunc)(code, (struct sockaddr *)&icmp6dst, 1077 &ip6cp); 1078 } 1079 } 1080 *mp = m; 1081 return (0); 1082 1083 freeit: 1084 m_freem(m); 1085 return (-1); 1086 } 1087 1088 void 1089 icmp6_mtudisc_update(struct ip6ctlparam *ip6cp, int validated) 1090 { 1091 struct in6_addr *dst = ip6cp->ip6c_finaldst; 1092 struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6; 1093 struct mbuf *m = ip6cp->ip6c_m; /* will be necessary for scope issue */ 1094 u_int mtu = ntohl(icmp6->icmp6_mtu); 1095 struct in_conninfo inc; 1096 1097 #if 0 1098 /* 1099 * RFC2460 section 5, last paragraph. 1100 * even though minimum link MTU for IPv6 is IPV6_MMTU, 1101 * we may see ICMPv6 too big with mtu < IPV6_MMTU 1102 * due to packet translator in the middle. 1103 * see ip6_output() and ip6_getpmtu() "alwaysfrag" case for 1104 * special handling. 1105 */ 1106 if (mtu < IPV6_MMTU) 1107 return; 1108 #endif 1109 1110 /* 1111 * we reject ICMPv6 too big with abnormally small value. 1112 * XXX what is the good definition of "abnormally small"? 1113 */ 1114 if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8) 1115 return; 1116 1117 if (!validated) 1118 return; 1119 1120 /* 1121 * In case the suggested mtu is less than IPV6_MMTU, we 1122 * only need to remember that it was for above mentioned 1123 * "alwaysfrag" case. 1124 * Try to be as close to the spec as possible. 1125 */ 1126 if (mtu < IPV6_MMTU) 1127 mtu = IPV6_MMTU - 8; 1128 1129 bzero(&inc, sizeof(inc)); 1130 inc.inc_flags = 1; /* IPv6 */ 1131 inc.inc6_faddr = *dst; 1132 if (in6_setscope(&inc.inc6_faddr, m->m_pkthdr.rcvif, NULL)) 1133 return; 1134 1135 if (mtu < tcp_maxmtu6(&inc, NULL)) { 1136 tcp_hc_updatemtu(&inc, mtu); 1137 icmp6stat.icp6s_pmtuchg++; 1138 } 1139 } 1140 1141 /* 1142 * Process a Node Information Query packet, based on 1143 * draft-ietf-ipngwg-icmp-name-lookups-07. 1144 * 1145 * Spec incompatibilities: 1146 * - IPv6 Subject address handling 1147 * - IPv4 Subject address handling support missing 1148 * - Proxy reply (answer even if it's not for me) 1149 * - joins NI group address at in6_ifattach() time only, does not cope 1150 * with hostname changes by sethostname(3) 1151 */ 1152 #define hostnamelen strlen(hostname) 1153 static struct mbuf * 1154 ni6_input(struct mbuf *m, int off) 1155 { 1156 struct icmp6_nodeinfo *ni6, *nni6; 1157 struct mbuf *n = NULL; 1158 u_int16_t qtype; 1159 int subjlen; 1160 int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); 1161 struct ni_reply_fqdn *fqdn; 1162 int addrs; /* for NI_QTYPE_NODEADDR */ 1163 struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */ 1164 struct in6_addr in6_subj; /* subject address */ 1165 struct ip6_hdr *ip6; 1166 int oldfqdn = 0; /* if 1, return pascal string (03 draft) */ 1167 char *subj = NULL; 1168 struct in6_ifaddr *ia6 = NULL; 1169 1170 ip6 = mtod(m, struct ip6_hdr *); 1171 #ifndef PULLDOWN_TEST 1172 ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off); 1173 #else 1174 IP6_EXTHDR_GET(ni6, struct icmp6_nodeinfo *, m, off, sizeof(*ni6)); 1175 if (ni6 == NULL) { 1176 /* m is already reclaimed */ 1177 return (NULL); 1178 } 1179 #endif 1180 1181 /* 1182 * Validate IPv6 source address. 1183 * The default configuration MUST be to refuse answering queries from 1184 * global-scope addresses according to RFC4602. 1185 * Notes: 1186 * - it's not very clear what "refuse" means; this implementation 1187 * simply drops it. 1188 * - it's not very easy to identify global-scope (unicast) addresses 1189 * since there are many prefixes for them. It should be safer 1190 * and in practice sufficient to check "all" but loopback and 1191 * link-local (note that site-local unicast was deprecated and 1192 * ULA is defined as global scope-wise) 1193 */ 1194 if ((icmp6_nodeinfo & ICMP6_NODEINFO_GLOBALOK) == 0 && 1195 !IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) && 1196 !IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) 1197 goto bad; 1198 1199 /* 1200 * Validate IPv6 destination address. 1201 * 1202 * The Responder must discard the Query without further processing 1203 * unless it is one of the Responder's unicast or anycast addresses, or 1204 * a link-local scope multicast address which the Responder has joined. 1205 * [RFC4602, Section 5.] 1206 */ 1207 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 1208 if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst)) 1209 goto bad; 1210 /* else it's a link-local multicast, fine */ 1211 } else { /* unicast or anycast */ 1212 if ((ia6 = ip6_getdstifaddr(m)) == NULL) 1213 goto bad; /* XXX impossible */ 1214 1215 if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) && 1216 !(icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK)) { 1217 nd6log((LOG_DEBUG, "ni6_input: ignore node info to " 1218 "a temporary address in %s:%d", 1219 __FILE__, __LINE__)); 1220 goto bad; 1221 } 1222 } 1223 1224 /* validate query Subject field. */ 1225 qtype = ntohs(ni6->ni_qtype); 1226 subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo); 1227 switch (qtype) { 1228 case NI_QTYPE_NOOP: 1229 case NI_QTYPE_SUPTYPES: 1230 /* 07 draft */ 1231 if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0) 1232 break; 1233 /* FALLTHROUGH */ 1234 case NI_QTYPE_FQDN: 1235 case NI_QTYPE_NODEADDR: 1236 case NI_QTYPE_IPV4ADDR: 1237 switch (ni6->ni_code) { 1238 case ICMP6_NI_SUBJ_IPV6: 1239 #if ICMP6_NI_SUBJ_IPV6 != 0 1240 case 0: 1241 #endif 1242 /* 1243 * backward compatibility - try to accept 03 draft 1244 * format, where no Subject is present. 1245 */ 1246 if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 && 1247 subjlen == 0) { 1248 oldfqdn++; 1249 break; 1250 } 1251 #if ICMP6_NI_SUBJ_IPV6 != 0 1252 if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6) 1253 goto bad; 1254 #endif 1255 1256 if (subjlen != sizeof(struct in6_addr)) 1257 goto bad; 1258 1259 /* 1260 * Validate Subject address. 1261 * 1262 * Not sure what exactly "address belongs to the node" 1263 * means in the spec, is it just unicast, or what? 1264 * 1265 * At this moment we consider Subject address as 1266 * "belong to the node" if the Subject address equals 1267 * to the IPv6 destination address; validation for 1268 * IPv6 destination address should have done enough 1269 * check for us. 1270 * 1271 * We do not do proxy at this moment. 1272 */ 1273 /* m_pulldown instead of copy? */ 1274 m_copydata(m, off + sizeof(struct icmp6_nodeinfo), 1275 subjlen, (caddr_t)&in6_subj); 1276 if (in6_setscope(&in6_subj, m->m_pkthdr.rcvif, NULL)) 1277 goto bad; 1278 1279 subj = (char *)&in6_subj; 1280 if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &in6_subj)) 1281 break; 1282 1283 /* 1284 * XXX if we are to allow other cases, we should really 1285 * be careful about scope here. 1286 * basically, we should disallow queries toward IPv6 1287 * destination X with subject Y, 1288 * if scope(X) > scope(Y). 1289 * if we allow scope(X) > scope(Y), it will result in 1290 * information leakage across scope boundary. 1291 */ 1292 goto bad; 1293 1294 case ICMP6_NI_SUBJ_FQDN: 1295 /* 1296 * Validate Subject name with gethostname(3). 1297 * 1298 * The behavior may need some debate, since: 1299 * - we are not sure if the node has FQDN as 1300 * hostname (returned by gethostname(3)). 1301 * - the code does wildcard match for truncated names. 1302 * however, we are not sure if we want to perform 1303 * wildcard match, if gethostname(3) side has 1304 * truncated hostname. 1305 */ 1306 n = ni6_nametodns(hostname, hostnamelen, 0); 1307 if (!n || n->m_next || n->m_len == 0) 1308 goto bad; 1309 IP6_EXTHDR_GET(subj, char *, m, 1310 off + sizeof(struct icmp6_nodeinfo), subjlen); 1311 if (subj == NULL) 1312 goto bad; 1313 if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *), 1314 n->m_len)) { 1315 goto bad; 1316 } 1317 m_freem(n); 1318 n = NULL; 1319 break; 1320 1321 case ICMP6_NI_SUBJ_IPV4: /* XXX: to be implemented? */ 1322 default: 1323 goto bad; 1324 } 1325 break; 1326 } 1327 1328 /* refuse based on configuration. XXX ICMP6_NI_REFUSED? */ 1329 switch (qtype) { 1330 case NI_QTYPE_FQDN: 1331 if ((icmp6_nodeinfo & ICMP6_NODEINFO_FQDNOK) == 0) 1332 goto bad; 1333 break; 1334 case NI_QTYPE_NODEADDR: 1335 case NI_QTYPE_IPV4ADDR: 1336 if ((icmp6_nodeinfo & ICMP6_NODEINFO_NODEADDROK) == 0) 1337 goto bad; 1338 break; 1339 } 1340 1341 /* guess reply length */ 1342 switch (qtype) { 1343 case NI_QTYPE_NOOP: 1344 break; /* no reply data */ 1345 case NI_QTYPE_SUPTYPES: 1346 replylen += sizeof(u_int32_t); 1347 break; 1348 case NI_QTYPE_FQDN: 1349 /* XXX will append an mbuf */ 1350 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); 1351 break; 1352 case NI_QTYPE_NODEADDR: 1353 addrs = ni6_addrs(ni6, m, &ifp, (struct in6_addr *)subj); 1354 if ((replylen += addrs * (sizeof(struct in6_addr) + 1355 sizeof(u_int32_t))) > MCLBYTES) 1356 replylen = MCLBYTES; /* XXX: will truncate pkt later */ 1357 break; 1358 case NI_QTYPE_IPV4ADDR: 1359 /* unsupported - should respond with unknown Qtype? */ 1360 break; 1361 default: 1362 /* 1363 * XXX: We must return a reply with the ICMP6 code 1364 * `unknown Qtype' in this case. However we regard the case 1365 * as an FQDN query for backward compatibility. 1366 * Older versions set a random value to this field, 1367 * so it rarely varies in the defined qtypes. 1368 * But the mechanism is not reliable... 1369 * maybe we should obsolete older versions. 1370 */ 1371 qtype = NI_QTYPE_FQDN; 1372 /* XXX will append an mbuf */ 1373 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); 1374 oldfqdn++; 1375 break; 1376 } 1377 1378 /* allocate an mbuf to reply. */ 1379 MGETHDR(n, M_DONTWAIT, m->m_type); 1380 if (n == NULL) { 1381 m_freem(m); 1382 return (NULL); 1383 } 1384 M_MOVE_PKTHDR(n, m); /* just for recvif */ 1385 if (replylen > MHLEN) { 1386 if (replylen > MCLBYTES) { 1387 /* 1388 * XXX: should we try to allocate more? But MCLBYTES 1389 * is probably much larger than IPV6_MMTU... 1390 */ 1391 goto bad; 1392 } 1393 MCLGET(n, M_DONTWAIT); 1394 if ((n->m_flags & M_EXT) == 0) { 1395 goto bad; 1396 } 1397 } 1398 n->m_pkthdr.len = n->m_len = replylen; 1399 1400 /* copy mbuf header and IPv6 + Node Information base headers */ 1401 bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr)); 1402 nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1); 1403 bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo)); 1404 1405 /* qtype dependent procedure */ 1406 switch (qtype) { 1407 case NI_QTYPE_NOOP: 1408 nni6->ni_code = ICMP6_NI_SUCCESS; 1409 nni6->ni_flags = 0; 1410 break; 1411 case NI_QTYPE_SUPTYPES: 1412 { 1413 u_int32_t v; 1414 nni6->ni_code = ICMP6_NI_SUCCESS; 1415 nni6->ni_flags = htons(0x0000); /* raw bitmap */ 1416 /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */ 1417 v = (u_int32_t)htonl(0x0000000f); 1418 bcopy(&v, nni6 + 1, sizeof(u_int32_t)); 1419 break; 1420 } 1421 case NI_QTYPE_FQDN: 1422 nni6->ni_code = ICMP6_NI_SUCCESS; 1423 fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) + 1424 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo)); 1425 nni6->ni_flags = 0; /* XXX: meaningless TTL */ 1426 fqdn->ni_fqdn_ttl = 0; /* ditto. */ 1427 /* 1428 * XXX do we really have FQDN in variable "hostname"? 1429 */ 1430 n->m_next = ni6_nametodns(hostname, hostnamelen, oldfqdn); 1431 if (n->m_next == NULL) 1432 goto bad; 1433 /* XXX we assume that n->m_next is not a chain */ 1434 if (n->m_next->m_next != NULL) 1435 goto bad; 1436 n->m_pkthdr.len += n->m_next->m_len; 1437 break; 1438 case NI_QTYPE_NODEADDR: 1439 { 1440 int lenlim, copied; 1441 1442 nni6->ni_code = ICMP6_NI_SUCCESS; 1443 n->m_pkthdr.len = n->m_len = 1444 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); 1445 lenlim = M_TRAILINGSPACE(n); 1446 copied = ni6_store_addrs(ni6, nni6, ifp, lenlim); 1447 /* XXX: reset mbuf length */ 1448 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + 1449 sizeof(struct icmp6_nodeinfo) + copied; 1450 break; 1451 } 1452 default: 1453 break; /* XXX impossible! */ 1454 } 1455 1456 nni6->ni_type = ICMP6_NI_REPLY; 1457 m_freem(m); 1458 return (n); 1459 1460 bad: 1461 m_freem(m); 1462 if (n) 1463 m_freem(n); 1464 return (NULL); 1465 } 1466 #undef hostnamelen 1467 1468 /* 1469 * make a mbuf with DNS-encoded string. no compression support. 1470 * 1471 * XXX names with less than 2 dots (like "foo" or "foo.section") will be 1472 * treated as truncated name (two \0 at the end). this is a wild guess. 1473 * 1474 * old - return pascal string if non-zero 1475 */ 1476 static struct mbuf * 1477 ni6_nametodns(const char *name, int namelen, int old) 1478 { 1479 struct mbuf *m; 1480 char *cp, *ep; 1481 const char *p, *q; 1482 int i, len, nterm; 1483 1484 if (old) 1485 len = namelen + 1; 1486 else 1487 len = MCLBYTES; 1488 1489 /* because MAXHOSTNAMELEN is usually 256, we use cluster mbuf */ 1490 MGET(m, M_DONTWAIT, MT_DATA); 1491 if (m && len > MLEN) { 1492 MCLGET(m, M_DONTWAIT); 1493 if ((m->m_flags & M_EXT) == 0) 1494 goto fail; 1495 } 1496 if (!m) 1497 goto fail; 1498 m->m_next = NULL; 1499 1500 if (old) { 1501 m->m_len = len; 1502 *mtod(m, char *) = namelen; 1503 bcopy(name, mtod(m, char *) + 1, namelen); 1504 return m; 1505 } else { 1506 m->m_len = 0; 1507 cp = mtod(m, char *); 1508 ep = mtod(m, char *) + M_TRAILINGSPACE(m); 1509 1510 /* if not certain about my name, return empty buffer */ 1511 if (namelen == 0) 1512 return m; 1513 1514 /* 1515 * guess if it looks like shortened hostname, or FQDN. 1516 * shortened hostname needs two trailing "\0". 1517 */ 1518 i = 0; 1519 for (p = name; p < name + namelen; p++) { 1520 if (*p && *p == '.') 1521 i++; 1522 } 1523 if (i < 2) 1524 nterm = 2; 1525 else 1526 nterm = 1; 1527 1528 p = name; 1529 while (cp < ep && p < name + namelen) { 1530 i = 0; 1531 for (q = p; q < name + namelen && *q && *q != '.'; q++) 1532 i++; 1533 /* result does not fit into mbuf */ 1534 if (cp + i + 1 >= ep) 1535 goto fail; 1536 /* 1537 * DNS label length restriction, RFC1035 page 8. 1538 * "i == 0" case is included here to avoid returning 1539 * 0-length label on "foo..bar". 1540 */ 1541 if (i <= 0 || i >= 64) 1542 goto fail; 1543 *cp++ = i; 1544 bcopy(p, cp, i); 1545 cp += i; 1546 p = q; 1547 if (p < name + namelen && *p == '.') 1548 p++; 1549 } 1550 /* termination */ 1551 if (cp + nterm >= ep) 1552 goto fail; 1553 while (nterm-- > 0) 1554 *cp++ = '\0'; 1555 m->m_len = cp - mtod(m, char *); 1556 return m; 1557 } 1558 1559 panic("should not reach here"); 1560 /* NOTREACHED */ 1561 1562 fail: 1563 if (m) 1564 m_freem(m); 1565 return NULL; 1566 } 1567 1568 /* 1569 * check if two DNS-encoded string matches. takes care of truncated 1570 * form (with \0\0 at the end). no compression support. 1571 * XXX upper/lowercase match (see RFC2065) 1572 */ 1573 static int 1574 ni6_dnsmatch(const char *a, int alen, const char *b, int blen) 1575 { 1576 const char *a0, *b0; 1577 int l; 1578 1579 /* simplest case - need validation? */ 1580 if (alen == blen && bcmp(a, b, alen) == 0) 1581 return 1; 1582 1583 a0 = a; 1584 b0 = b; 1585 1586 /* termination is mandatory */ 1587 if (alen < 2 || blen < 2) 1588 return 0; 1589 if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0') 1590 return 0; 1591 alen--; 1592 blen--; 1593 1594 while (a - a0 < alen && b - b0 < blen) { 1595 if (a - a0 + 1 > alen || b - b0 + 1 > blen) 1596 return 0; 1597 1598 if ((signed char)a[0] < 0 || (signed char)b[0] < 0) 1599 return 0; 1600 /* we don't support compression yet */ 1601 if (a[0] >= 64 || b[0] >= 64) 1602 return 0; 1603 1604 /* truncated case */ 1605 if (a[0] == 0 && a - a0 == alen - 1) 1606 return 1; 1607 if (b[0] == 0 && b - b0 == blen - 1) 1608 return 1; 1609 if (a[0] == 0 || b[0] == 0) 1610 return 0; 1611 1612 if (a[0] != b[0]) 1613 return 0; 1614 l = a[0]; 1615 if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen) 1616 return 0; 1617 if (bcmp(a + 1, b + 1, l) != 0) 1618 return 0; 1619 1620 a += 1 + l; 1621 b += 1 + l; 1622 } 1623 1624 if (a - a0 == alen && b - b0 == blen) 1625 return 1; 1626 else 1627 return 0; 1628 } 1629 1630 /* 1631 * calculate the number of addresses to be returned in the node info reply. 1632 */ 1633 static int 1634 ni6_addrs(struct icmp6_nodeinfo *ni6, struct mbuf *m, struct ifnet **ifpp, 1635 struct in6_addr *subj) 1636 { 1637 struct ifnet *ifp; 1638 struct in6_ifaddr *ifa6; 1639 struct ifaddr *ifa; 1640 int addrs = 0, addrsofif, iffound = 0; 1641 int niflags = ni6->ni_flags; 1642 1643 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) { 1644 switch (ni6->ni_code) { 1645 case ICMP6_NI_SUBJ_IPV6: 1646 if (subj == NULL) /* must be impossible... */ 1647 return (0); 1648 break; 1649 default: 1650 /* 1651 * XXX: we only support IPv6 subject address for 1652 * this Qtype. 1653 */ 1654 return (0); 1655 } 1656 } 1657 1658 IFNET_RLOCK(); 1659 for (ifp = TAILQ_FIRST(&ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list)) { 1660 addrsofif = 0; 1661 TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) { 1662 if (ifa->ifa_addr->sa_family != AF_INET6) 1663 continue; 1664 ifa6 = (struct in6_ifaddr *)ifa; 1665 1666 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 && 1667 IN6_ARE_ADDR_EQUAL(subj, &ifa6->ia_addr.sin6_addr)) 1668 iffound = 1; 1669 1670 /* 1671 * IPv4-mapped addresses can only be returned by a 1672 * Node Information proxy, since they represent 1673 * addresses of IPv4-only nodes, which perforce do 1674 * not implement this protocol. 1675 * [icmp-name-lookups-07, Section 5.4] 1676 * So we don't support NI_NODEADDR_FLAG_COMPAT in 1677 * this function at this moment. 1678 */ 1679 1680 /* What do we have to do about ::1? */ 1681 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { 1682 case IPV6_ADDR_SCOPE_LINKLOCAL: 1683 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) 1684 continue; 1685 break; 1686 case IPV6_ADDR_SCOPE_SITELOCAL: 1687 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) 1688 continue; 1689 break; 1690 case IPV6_ADDR_SCOPE_GLOBAL: 1691 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) 1692 continue; 1693 break; 1694 default: 1695 continue; 1696 } 1697 1698 /* 1699 * check if anycast is okay. 1700 * XXX: just experimental. not in the spec. 1701 */ 1702 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && 1703 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) 1704 continue; /* we need only unicast addresses */ 1705 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && 1706 (icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) { 1707 continue; 1708 } 1709 addrsofif++; /* count the address */ 1710 } 1711 if (iffound) { 1712 *ifpp = ifp; 1713 IFNET_RUNLOCK(); 1714 return (addrsofif); 1715 } 1716 1717 addrs += addrsofif; 1718 } 1719 IFNET_RUNLOCK(); 1720 1721 return (addrs); 1722 } 1723 1724 static int 1725 ni6_store_addrs(struct icmp6_nodeinfo *ni6, struct icmp6_nodeinfo *nni6, 1726 struct ifnet *ifp0, int resid) 1727 { 1728 struct ifnet *ifp = ifp0 ? ifp0 : TAILQ_FIRST(&ifnet); 1729 struct in6_ifaddr *ifa6; 1730 struct ifaddr *ifa; 1731 struct ifnet *ifp_dep = NULL; 1732 int copied = 0, allow_deprecated = 0; 1733 u_char *cp = (u_char *)(nni6 + 1); 1734 int niflags = ni6->ni_flags; 1735 u_int32_t ltime; 1736 1737 if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL)) 1738 return (0); /* needless to copy */ 1739 1740 IFNET_RLOCK(); 1741 again: 1742 1743 for (; ifp; ifp = TAILQ_NEXT(ifp, if_list)) { 1744 for (ifa = ifp->if_addrlist.tqh_first; ifa; 1745 ifa = ifa->ifa_list.tqe_next) { 1746 if (ifa->ifa_addr->sa_family != AF_INET6) 1747 continue; 1748 ifa6 = (struct in6_ifaddr *)ifa; 1749 1750 if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 && 1751 allow_deprecated == 0) { 1752 /* 1753 * prefererred address should be put before 1754 * deprecated addresses. 1755 */ 1756 1757 /* record the interface for later search */ 1758 if (ifp_dep == NULL) 1759 ifp_dep = ifp; 1760 1761 continue; 1762 } else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 && 1763 allow_deprecated != 0) 1764 continue; /* we now collect deprecated addrs */ 1765 1766 /* What do we have to do about ::1? */ 1767 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { 1768 case IPV6_ADDR_SCOPE_LINKLOCAL: 1769 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) 1770 continue; 1771 break; 1772 case IPV6_ADDR_SCOPE_SITELOCAL: 1773 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) 1774 continue; 1775 break; 1776 case IPV6_ADDR_SCOPE_GLOBAL: 1777 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) 1778 continue; 1779 break; 1780 default: 1781 continue; 1782 } 1783 1784 /* 1785 * check if anycast is okay. 1786 * XXX: just experimental. not in the spec. 1787 */ 1788 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && 1789 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) 1790 continue; 1791 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && 1792 (icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) { 1793 continue; 1794 } 1795 1796 /* now we can copy the address */ 1797 if (resid < sizeof(struct in6_addr) + 1798 sizeof(u_int32_t)) { 1799 /* 1800 * We give up much more copy. 1801 * Set the truncate flag and return. 1802 */ 1803 nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE; 1804 IFNET_RUNLOCK(); 1805 return (copied); 1806 } 1807 1808 /* 1809 * Set the TTL of the address. 1810 * The TTL value should be one of the following 1811 * according to the specification: 1812 * 1813 * 1. The remaining lifetime of a DHCP lease on the 1814 * address, or 1815 * 2. The remaining Valid Lifetime of a prefix from 1816 * which the address was derived through Stateless 1817 * Autoconfiguration. 1818 * 1819 * Note that we currently do not support stateful 1820 * address configuration by DHCPv6, so the former 1821 * case can't happen. 1822 */ 1823 if (ifa6->ia6_lifetime.ia6t_expire == 0) 1824 ltime = ND6_INFINITE_LIFETIME; 1825 else { 1826 if (ifa6->ia6_lifetime.ia6t_expire > 1827 time_second) 1828 ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_second); 1829 else 1830 ltime = 0; 1831 } 1832 1833 bcopy(<ime, cp, sizeof(u_int32_t)); 1834 cp += sizeof(u_int32_t); 1835 1836 /* copy the address itself */ 1837 bcopy(&ifa6->ia_addr.sin6_addr, cp, 1838 sizeof(struct in6_addr)); 1839 in6_clearscope((struct in6_addr *)cp); /* XXX */ 1840 cp += sizeof(struct in6_addr); 1841 1842 resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t)); 1843 copied += (sizeof(struct in6_addr) + sizeof(u_int32_t)); 1844 } 1845 if (ifp0) /* we need search only on the specified IF */ 1846 break; 1847 } 1848 1849 if (allow_deprecated == 0 && ifp_dep != NULL) { 1850 ifp = ifp_dep; 1851 allow_deprecated = 1; 1852 1853 goto again; 1854 } 1855 1856 IFNET_RUNLOCK(); 1857 1858 return (copied); 1859 } 1860 1861 /* 1862 * XXX almost dup'ed code with rip6_input. 1863 */ 1864 static int 1865 icmp6_rip6_input(struct mbuf **mp, int off) 1866 { 1867 struct mbuf *m = *mp; 1868 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1869 struct in6pcb *in6p; 1870 struct in6pcb *last = NULL; 1871 struct sockaddr_in6 fromsa; 1872 struct icmp6_hdr *icmp6; 1873 struct mbuf *opts = NULL; 1874 1875 #ifndef PULLDOWN_TEST 1876 /* this is assumed to be safe. */ 1877 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off); 1878 #else 1879 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6)); 1880 if (icmp6 == NULL) { 1881 /* m is already reclaimed */ 1882 return (IPPROTO_DONE); 1883 } 1884 #endif 1885 1886 /* 1887 * XXX: the address may have embedded scope zone ID, which should be 1888 * hidden from applications. 1889 */ 1890 bzero(&fromsa, sizeof(fromsa)); 1891 fromsa.sin6_family = AF_INET6; 1892 fromsa.sin6_len = sizeof(struct sockaddr_in6); 1893 fromsa.sin6_addr = ip6->ip6_src; 1894 if (sa6_recoverscope(&fromsa)) { 1895 m_freem(m); 1896 return (IPPROTO_DONE); 1897 } 1898 1899 INP_INFO_RLOCK(&ripcbinfo); 1900 LIST_FOREACH(in6p, &ripcb, inp_list) { 1901 INP_LOCK(in6p); 1902 if ((in6p->inp_vflag & INP_IPV6) == 0) { 1903 docontinue: 1904 INP_UNLOCK(in6p); 1905 continue; 1906 } 1907 if (in6p->in6p_ip6_nxt != IPPROTO_ICMPV6) 1908 goto docontinue; 1909 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) && 1910 !IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &ip6->ip6_dst)) 1911 goto docontinue; 1912 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr) && 1913 !IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src)) 1914 goto docontinue; 1915 if (in6p->in6p_icmp6filt 1916 && ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type, 1917 in6p->in6p_icmp6filt)) 1918 goto docontinue; 1919 if (last) { 1920 struct mbuf *n = NULL; 1921 1922 /* 1923 * Recent network drivers tend to allocate a single 1924 * mbuf cluster, rather than to make a couple of 1925 * mbufs without clusters. Also, since the IPv6 code 1926 * path tries to avoid m_pullup(), it is highly 1927 * probable that we still have an mbuf cluster here 1928 * even though the necessary length can be stored in an 1929 * mbuf's internal buffer. 1930 * Meanwhile, the default size of the receive socket 1931 * buffer for raw sockets is not so large. This means 1932 * the possibility of packet loss is relatively higher 1933 * than before. To avoid this scenario, we copy the 1934 * received data to a separate mbuf that does not use 1935 * a cluster, if possible. 1936 * XXX: it is better to copy the data after stripping 1937 * intermediate headers. 1938 */ 1939 if ((m->m_flags & M_EXT) && m->m_next == NULL && 1940 m->m_len <= MHLEN) { 1941 MGET(n, M_DONTWAIT, m->m_type); 1942 if (n != NULL) { 1943 if (m_dup_pkthdr(n, m, M_NOWAIT)) { 1944 bcopy(m->m_data, n->m_data, 1945 m->m_len); 1946 n->m_len = m->m_len; 1947 } else { 1948 m_free(n); 1949 n = NULL; 1950 } 1951 } 1952 } 1953 if (n != NULL || 1954 (n = m_copy(m, 0, (int)M_COPYALL)) != NULL) { 1955 if (last->in6p_flags & IN6P_CONTROLOPTS) 1956 ip6_savecontrol(last, n, &opts); 1957 /* strip intermediate headers */ 1958 m_adj(n, off); 1959 SOCKBUF_LOCK(&last->in6p_socket->so_rcv); 1960 if (sbappendaddr_locked( 1961 &last->in6p_socket->so_rcv, 1962 (struct sockaddr *)&fromsa, n, opts) 1963 == 0) { 1964 /* should notify about lost packet */ 1965 m_freem(n); 1966 if (opts) { 1967 m_freem(opts); 1968 } 1969 SOCKBUF_UNLOCK( 1970 &last->in6p_socket->so_rcv); 1971 } else 1972 sorwakeup_locked(last->in6p_socket); 1973 opts = NULL; 1974 } 1975 INP_UNLOCK(last); 1976 } 1977 last = in6p; 1978 } 1979 if (last) { 1980 if (last->in6p_flags & IN6P_CONTROLOPTS) 1981 ip6_savecontrol(last, m, &opts); 1982 /* strip intermediate headers */ 1983 m_adj(m, off); 1984 1985 /* avoid using mbuf clusters if possible (see above) */ 1986 if ((m->m_flags & M_EXT) && m->m_next == NULL && 1987 m->m_len <= MHLEN) { 1988 struct mbuf *n; 1989 1990 MGET(n, M_DONTWAIT, m->m_type); 1991 if (n != NULL) { 1992 if (m_dup_pkthdr(n, m, M_NOWAIT)) { 1993 bcopy(m->m_data, n->m_data, m->m_len); 1994 n->m_len = m->m_len; 1995 1996 m_freem(m); 1997 m = n; 1998 } else { 1999 m_freem(n); 2000 n = NULL; 2001 } 2002 } 2003 } 2004 SOCKBUF_LOCK(&last->in6p_socket->so_rcv); 2005 if (sbappendaddr_locked(&last->in6p_socket->so_rcv, 2006 (struct sockaddr *)&fromsa, m, opts) == 0) { 2007 m_freem(m); 2008 if (opts) 2009 m_freem(opts); 2010 SOCKBUF_UNLOCK(&last->in6p_socket->so_rcv); 2011 } else 2012 sorwakeup_locked(last->in6p_socket); 2013 INP_UNLOCK(last); 2014 } else { 2015 m_freem(m); 2016 ip6stat.ip6s_delivered--; 2017 } 2018 INP_INFO_RUNLOCK(&ripcbinfo); 2019 return IPPROTO_DONE; 2020 } 2021 2022 /* 2023 * Reflect the ip6 packet back to the source. 2024 * OFF points to the icmp6 header, counted from the top of the mbuf. 2025 */ 2026 void 2027 icmp6_reflect(struct mbuf *m, size_t off) 2028 { 2029 struct ip6_hdr *ip6; 2030 struct icmp6_hdr *icmp6; 2031 struct in6_ifaddr *ia; 2032 int plen; 2033 int type, code; 2034 struct ifnet *outif = NULL; 2035 struct in6_addr origdst, *src = NULL; 2036 2037 /* too short to reflect */ 2038 if (off < sizeof(struct ip6_hdr)) { 2039 nd6log((LOG_DEBUG, 2040 "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n", 2041 (u_long)off, (u_long)sizeof(struct ip6_hdr), 2042 __FILE__, __LINE__)); 2043 goto bad; 2044 } 2045 2046 /* 2047 * If there are extra headers between IPv6 and ICMPv6, strip 2048 * off that header first. 2049 */ 2050 #ifdef DIAGNOSTIC 2051 if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN) 2052 panic("assumption failed in icmp6_reflect"); 2053 #endif 2054 if (off > sizeof(struct ip6_hdr)) { 2055 size_t l; 2056 struct ip6_hdr nip6; 2057 2058 l = off - sizeof(struct ip6_hdr); 2059 m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6); 2060 m_adj(m, l); 2061 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 2062 if (m->m_len < l) { 2063 if ((m = m_pullup(m, l)) == NULL) 2064 return; 2065 } 2066 bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6)); 2067 } else /* off == sizeof(struct ip6_hdr) */ { 2068 size_t l; 2069 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 2070 if (m->m_len < l) { 2071 if ((m = m_pullup(m, l)) == NULL) 2072 return; 2073 } 2074 } 2075 plen = m->m_pkthdr.len - sizeof(struct ip6_hdr); 2076 ip6 = mtod(m, struct ip6_hdr *); 2077 ip6->ip6_nxt = IPPROTO_ICMPV6; 2078 icmp6 = (struct icmp6_hdr *)(ip6 + 1); 2079 type = icmp6->icmp6_type; /* keep type for statistics */ 2080 code = icmp6->icmp6_code; /* ditto. */ 2081 2082 origdst = ip6->ip6_dst; 2083 /* 2084 * ip6_input() drops a packet if its src is multicast. 2085 * So, the src is never multicast. 2086 */ 2087 ip6->ip6_dst = ip6->ip6_src; 2088 2089 /* 2090 * If the incoming packet was addressed directly to us (i.e. unicast), 2091 * use dst as the src for the reply. 2092 * The IN6_IFF_NOTREADY case should be VERY rare, but is possible 2093 * (for example) when we encounter an error while forwarding procedure 2094 * destined to a duplicated address of ours. 2095 * Note that ip6_getdstifaddr() may fail if we are in an error handling 2096 * procedure of an outgoing packet of our own, in which case we need 2097 * to search in the ifaddr list. 2098 */ 2099 if (!IN6_IS_ADDR_MULTICAST(&origdst)) { 2100 if ((ia = ip6_getdstifaddr(m))) { 2101 if (!(ia->ia6_flags & 2102 (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) 2103 src = &ia->ia_addr.sin6_addr; 2104 } else { 2105 struct sockaddr_in6 d; 2106 2107 bzero(&d, sizeof(d)); 2108 d.sin6_family = AF_INET6; 2109 d.sin6_len = sizeof(d); 2110 d.sin6_addr = origdst; 2111 ia = (struct in6_ifaddr *) 2112 ifa_ifwithaddr((struct sockaddr *)&d); 2113 if (ia && 2114 !(ia->ia6_flags & 2115 (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) { 2116 src = &ia->ia_addr.sin6_addr; 2117 } 2118 } 2119 } 2120 2121 if (src == NULL) { 2122 int e; 2123 struct sockaddr_in6 sin6; 2124 struct route_in6 ro; 2125 2126 /* 2127 * This case matches to multicasts, our anycast, or unicasts 2128 * that we do not own. Select a source address based on the 2129 * source address of the erroneous packet. 2130 */ 2131 bzero(&sin6, sizeof(sin6)); 2132 sin6.sin6_family = AF_INET6; 2133 sin6.sin6_len = sizeof(sin6); 2134 sin6.sin6_addr = ip6->ip6_dst; /* zone ID should be embedded */ 2135 2136 bzero(&ro, sizeof(ro)); 2137 src = in6_selectsrc(&sin6, NULL, NULL, &ro, NULL, &outif, &e); 2138 if (ro.ro_rt) 2139 RTFREE(ro.ro_rt); /* XXX: we could use this */ 2140 if (src == NULL) { 2141 char ip6buf[INET6_ADDRSTRLEN]; 2142 nd6log((LOG_DEBUG, 2143 "icmp6_reflect: source can't be determined: " 2144 "dst=%s, error=%d\n", 2145 ip6_sprintf(ip6buf, &sin6.sin6_addr), e)); 2146 goto bad; 2147 } 2148 } 2149 2150 ip6->ip6_src = *src; 2151 ip6->ip6_flow = 0; 2152 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2153 ip6->ip6_vfc |= IPV6_VERSION; 2154 ip6->ip6_nxt = IPPROTO_ICMPV6; 2155 if (outif) 2156 ip6->ip6_hlim = ND_IFINFO(outif)->chlim; 2157 else if (m->m_pkthdr.rcvif) { 2158 /* XXX: This may not be the outgoing interface */ 2159 ip6->ip6_hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim; 2160 } else 2161 ip6->ip6_hlim = ip6_defhlim; 2162 2163 icmp6->icmp6_cksum = 0; 2164 icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2165 sizeof(struct ip6_hdr), plen); 2166 2167 /* 2168 * XXX option handling 2169 */ 2170 2171 m->m_flags &= ~(M_BCAST|M_MCAST); 2172 2173 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2174 if (outif) 2175 icmp6_ifoutstat_inc(outif, type, code); 2176 2177 return; 2178 2179 bad: 2180 m_freem(m); 2181 return; 2182 } 2183 2184 void 2185 icmp6_fasttimo(void) 2186 { 2187 2188 return; 2189 } 2190 2191 static const char * 2192 icmp6_redirect_diag(struct in6_addr *src6, struct in6_addr *dst6, 2193 struct in6_addr *tgt6) 2194 { 2195 static char buf[1024]; 2196 char ip6bufs[INET6_ADDRSTRLEN]; 2197 char ip6bufd[INET6_ADDRSTRLEN]; 2198 char ip6buft[INET6_ADDRSTRLEN]; 2199 snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)", 2200 ip6_sprintf(ip6bufs, src6), ip6_sprintf(ip6bufd, dst6), 2201 ip6_sprintf(ip6buft, tgt6)); 2202 return buf; 2203 } 2204 2205 void 2206 icmp6_redirect_input(struct mbuf *m, int off) 2207 { 2208 struct ifnet *ifp; 2209 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 2210 struct nd_redirect *nd_rd; 2211 int icmp6len = ntohs(ip6->ip6_plen); 2212 char *lladdr = NULL; 2213 int lladdrlen = 0; 2214 u_char *redirhdr = NULL; 2215 int redirhdrlen = 0; 2216 struct rtentry *rt = NULL; 2217 int is_router; 2218 int is_onlink; 2219 struct in6_addr src6 = ip6->ip6_src; 2220 struct in6_addr redtgt6; 2221 struct in6_addr reddst6; 2222 union nd_opts ndopts; 2223 char ip6buf[INET6_ADDRSTRLEN]; 2224 2225 if (!m) 2226 return; 2227 2228 ifp = m->m_pkthdr.rcvif; 2229 2230 if (!ifp) 2231 return; 2232 2233 /* XXX if we are router, we don't update route by icmp6 redirect */ 2234 if (ip6_forwarding) 2235 goto freeit; 2236 if (!icmp6_rediraccept) 2237 goto freeit; 2238 2239 #ifndef PULLDOWN_TEST 2240 IP6_EXTHDR_CHECK(m, off, icmp6len,); 2241 nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off); 2242 #else 2243 IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len); 2244 if (nd_rd == NULL) { 2245 icmp6stat.icp6s_tooshort++; 2246 return; 2247 } 2248 #endif 2249 redtgt6 = nd_rd->nd_rd_target; 2250 reddst6 = nd_rd->nd_rd_dst; 2251 2252 if (in6_setscope(&redtgt6, m->m_pkthdr.rcvif, NULL) || 2253 in6_setscope(&reddst6, m->m_pkthdr.rcvif, NULL)) { 2254 goto freeit; 2255 } 2256 2257 /* validation */ 2258 if (!IN6_IS_ADDR_LINKLOCAL(&src6)) { 2259 nd6log((LOG_ERR, 2260 "ICMP6 redirect sent from %s rejected; " 2261 "must be from linklocal\n", 2262 ip6_sprintf(ip6buf, &src6))); 2263 goto bad; 2264 } 2265 if (ip6->ip6_hlim != 255) { 2266 nd6log((LOG_ERR, 2267 "ICMP6 redirect sent from %s rejected; " 2268 "hlim=%d (must be 255)\n", 2269 ip6_sprintf(ip6buf, &src6), ip6->ip6_hlim)); 2270 goto bad; 2271 } 2272 { 2273 /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */ 2274 struct sockaddr_in6 sin6; 2275 struct in6_addr *gw6; 2276 2277 bzero(&sin6, sizeof(sin6)); 2278 sin6.sin6_family = AF_INET6; 2279 sin6.sin6_len = sizeof(struct sockaddr_in6); 2280 bcopy(&reddst6, &sin6.sin6_addr, sizeof(reddst6)); 2281 rt = rtalloc1((struct sockaddr *)&sin6, 0, 0UL); 2282 if (rt) { 2283 if (rt->rt_gateway == NULL || 2284 rt->rt_gateway->sa_family != AF_INET6) { 2285 nd6log((LOG_ERR, 2286 "ICMP6 redirect rejected; no route " 2287 "with inet6 gateway found for redirect dst: %s\n", 2288 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2289 RTFREE_LOCKED(rt); 2290 goto bad; 2291 } 2292 2293 gw6 = &(((struct sockaddr_in6 *)rt->rt_gateway)->sin6_addr); 2294 if (bcmp(&src6, gw6, sizeof(struct in6_addr)) != 0) { 2295 nd6log((LOG_ERR, 2296 "ICMP6 redirect rejected; " 2297 "not equal to gw-for-src=%s (must be same): " 2298 "%s\n", 2299 ip6_sprintf(ip6buf, gw6), 2300 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2301 RTFREE_LOCKED(rt); 2302 goto bad; 2303 } 2304 } else { 2305 nd6log((LOG_ERR, 2306 "ICMP6 redirect rejected; " 2307 "no route found for redirect dst: %s\n", 2308 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2309 goto bad; 2310 } 2311 RTFREE_LOCKED(rt); 2312 rt = NULL; 2313 } 2314 if (IN6_IS_ADDR_MULTICAST(&reddst6)) { 2315 nd6log((LOG_ERR, 2316 "ICMP6 redirect rejected; " 2317 "redirect dst must be unicast: %s\n", 2318 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2319 goto bad; 2320 } 2321 2322 is_router = is_onlink = 0; 2323 if (IN6_IS_ADDR_LINKLOCAL(&redtgt6)) 2324 is_router = 1; /* router case */ 2325 if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0) 2326 is_onlink = 1; /* on-link destination case */ 2327 if (!is_router && !is_onlink) { 2328 nd6log((LOG_ERR, 2329 "ICMP6 redirect rejected; " 2330 "neither router case nor onlink case: %s\n", 2331 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2332 goto bad; 2333 } 2334 /* validation passed */ 2335 2336 icmp6len -= sizeof(*nd_rd); 2337 nd6_option_init(nd_rd + 1, icmp6len, &ndopts); 2338 if (nd6_options(&ndopts) < 0) { 2339 nd6log((LOG_INFO, "icmp6_redirect_input: " 2340 "invalid ND option, rejected: %s\n", 2341 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2342 /* nd6_options have incremented stats */ 2343 goto freeit; 2344 } 2345 2346 if (ndopts.nd_opts_tgt_lladdr) { 2347 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 2348 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 2349 } 2350 2351 if (ndopts.nd_opts_rh) { 2352 redirhdrlen = ndopts.nd_opts_rh->nd_opt_rh_len; 2353 redirhdr = (u_char *)(ndopts.nd_opts_rh + 1); /* xxx */ 2354 } 2355 2356 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 2357 nd6log((LOG_INFO, 2358 "icmp6_redirect_input: lladdrlen mismatch for %s " 2359 "(if %d, icmp6 packet %d): %s\n", 2360 ip6_sprintf(ip6buf, &redtgt6), 2361 ifp->if_addrlen, lladdrlen - 2, 2362 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2363 goto bad; 2364 } 2365 2366 /* RFC 2461 8.3 */ 2367 nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT, 2368 is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER); 2369 2370 if (!is_onlink) { /* better router case. perform rtredirect. */ 2371 /* perform rtredirect */ 2372 struct sockaddr_in6 sdst; 2373 struct sockaddr_in6 sgw; 2374 struct sockaddr_in6 ssrc; 2375 2376 bzero(&sdst, sizeof(sdst)); 2377 bzero(&sgw, sizeof(sgw)); 2378 bzero(&ssrc, sizeof(ssrc)); 2379 sdst.sin6_family = sgw.sin6_family = ssrc.sin6_family = AF_INET6; 2380 sdst.sin6_len = sgw.sin6_len = ssrc.sin6_len = 2381 sizeof(struct sockaddr_in6); 2382 bcopy(&redtgt6, &sgw.sin6_addr, sizeof(struct in6_addr)); 2383 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr)); 2384 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr)); 2385 rtredirect((struct sockaddr *)&sdst, (struct sockaddr *)&sgw, 2386 (struct sockaddr *)NULL, RTF_GATEWAY | RTF_HOST, 2387 (struct sockaddr *)&ssrc); 2388 } 2389 /* finally update cached route in each socket via pfctlinput */ 2390 { 2391 struct sockaddr_in6 sdst; 2392 2393 bzero(&sdst, sizeof(sdst)); 2394 sdst.sin6_family = AF_INET6; 2395 sdst.sin6_len = sizeof(struct sockaddr_in6); 2396 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr)); 2397 pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst); 2398 #ifdef IPSEC 2399 key_sa_routechange((struct sockaddr *)&sdst); 2400 #endif /* IPSEC */ 2401 } 2402 2403 freeit: 2404 m_freem(m); 2405 return; 2406 2407 bad: 2408 icmp6stat.icp6s_badredirect++; 2409 m_freem(m); 2410 } 2411 2412 void 2413 icmp6_redirect_output(struct mbuf *m0, struct rtentry *rt) 2414 { 2415 struct ifnet *ifp; /* my outgoing interface */ 2416 struct in6_addr *ifp_ll6; 2417 struct in6_addr *router_ll6; 2418 struct ip6_hdr *sip6; /* m0 as struct ip6_hdr */ 2419 struct mbuf *m = NULL; /* newly allocated one */ 2420 struct ip6_hdr *ip6; /* m as struct ip6_hdr */ 2421 struct nd_redirect *nd_rd; 2422 size_t maxlen; 2423 u_char *p; 2424 struct ifnet *outif = NULL; 2425 struct sockaddr_in6 src_sa; 2426 2427 icmp6_errcount(&icmp6stat.icp6s_outerrhist, ND_REDIRECT, 0); 2428 2429 /* if we are not router, we don't send icmp6 redirect */ 2430 if (!ip6_forwarding) 2431 goto fail; 2432 2433 /* sanity check */ 2434 if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp)) 2435 goto fail; 2436 2437 /* 2438 * Address check: 2439 * the source address must identify a neighbor, and 2440 * the destination address must not be a multicast address 2441 * [RFC 2461, sec 8.2] 2442 */ 2443 sip6 = mtod(m0, struct ip6_hdr *); 2444 bzero(&src_sa, sizeof(src_sa)); 2445 src_sa.sin6_family = AF_INET6; 2446 src_sa.sin6_len = sizeof(src_sa); 2447 src_sa.sin6_addr = sip6->ip6_src; 2448 if (nd6_is_addr_neighbor(&src_sa, ifp) == 0) 2449 goto fail; 2450 if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst)) 2451 goto fail; /* what should we do here? */ 2452 2453 /* rate limit */ 2454 if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0)) 2455 goto fail; 2456 2457 /* 2458 * Since we are going to append up to 1280 bytes (= IPV6_MMTU), 2459 * we almost always ask for an mbuf cluster for simplicity. 2460 * (MHLEN < IPV6_MMTU is almost always true) 2461 */ 2462 #if IPV6_MMTU >= MCLBYTES 2463 # error assumption failed about IPV6_MMTU and MCLBYTES 2464 #endif 2465 MGETHDR(m, M_DONTWAIT, MT_HEADER); 2466 if (m && IPV6_MMTU >= MHLEN) 2467 MCLGET(m, M_DONTWAIT); 2468 if (!m) 2469 goto fail; 2470 m->m_pkthdr.rcvif = NULL; 2471 m->m_len = 0; 2472 maxlen = M_TRAILINGSPACE(m); 2473 maxlen = min(IPV6_MMTU, maxlen); 2474 /* just for safety */ 2475 if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) + 2476 ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) { 2477 goto fail; 2478 } 2479 2480 { 2481 /* get ip6 linklocal address for ifp(my outgoing interface). */ 2482 struct in6_ifaddr *ia; 2483 if ((ia = in6ifa_ifpforlinklocal(ifp, 2484 IN6_IFF_NOTREADY| 2485 IN6_IFF_ANYCAST)) == NULL) 2486 goto fail; 2487 ifp_ll6 = &ia->ia_addr.sin6_addr; 2488 } 2489 2490 /* get ip6 linklocal address for the router. */ 2491 if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) { 2492 struct sockaddr_in6 *sin6; 2493 sin6 = (struct sockaddr_in6 *)rt->rt_gateway; 2494 router_ll6 = &sin6->sin6_addr; 2495 if (!IN6_IS_ADDR_LINKLOCAL(router_ll6)) 2496 router_ll6 = (struct in6_addr *)NULL; 2497 } else 2498 router_ll6 = (struct in6_addr *)NULL; 2499 2500 /* ip6 */ 2501 ip6 = mtod(m, struct ip6_hdr *); 2502 ip6->ip6_flow = 0; 2503 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2504 ip6->ip6_vfc |= IPV6_VERSION; 2505 /* ip6->ip6_plen will be set later */ 2506 ip6->ip6_nxt = IPPROTO_ICMPV6; 2507 ip6->ip6_hlim = 255; 2508 /* ip6->ip6_src must be linklocal addr for my outgoing if. */ 2509 bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr)); 2510 bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr)); 2511 2512 /* ND Redirect */ 2513 nd_rd = (struct nd_redirect *)(ip6 + 1); 2514 nd_rd->nd_rd_type = ND_REDIRECT; 2515 nd_rd->nd_rd_code = 0; 2516 nd_rd->nd_rd_reserved = 0; 2517 if (rt->rt_flags & RTF_GATEWAY) { 2518 /* 2519 * nd_rd->nd_rd_target must be a link-local address in 2520 * better router cases. 2521 */ 2522 if (!router_ll6) 2523 goto fail; 2524 bcopy(router_ll6, &nd_rd->nd_rd_target, 2525 sizeof(nd_rd->nd_rd_target)); 2526 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2527 sizeof(nd_rd->nd_rd_dst)); 2528 } else { 2529 /* make sure redtgt == reddst */ 2530 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target, 2531 sizeof(nd_rd->nd_rd_target)); 2532 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2533 sizeof(nd_rd->nd_rd_dst)); 2534 } 2535 2536 p = (u_char *)(nd_rd + 1); 2537 2538 if (!router_ll6) 2539 goto nolladdropt; 2540 2541 { 2542 /* target lladdr option */ 2543 struct rtentry *rt_router = NULL; 2544 int len; 2545 struct sockaddr_dl *sdl; 2546 struct nd_opt_hdr *nd_opt; 2547 char *lladdr; 2548 2549 rt_router = nd6_lookup(router_ll6, 0, ifp); 2550 if (!rt_router) 2551 goto nolladdropt; 2552 len = sizeof(*nd_opt) + ifp->if_addrlen; 2553 len = (len + 7) & ~7; /* round by 8 */ 2554 /* safety check */ 2555 if (len + (p - (u_char *)ip6) > maxlen) 2556 goto nolladdropt; 2557 if (!(rt_router->rt_flags & RTF_GATEWAY) && 2558 (rt_router->rt_flags & RTF_LLINFO) && 2559 (rt_router->rt_gateway->sa_family == AF_LINK) && 2560 (sdl = (struct sockaddr_dl *)rt_router->rt_gateway) && 2561 sdl->sdl_alen) { 2562 nd_opt = (struct nd_opt_hdr *)p; 2563 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 2564 nd_opt->nd_opt_len = len >> 3; 2565 lladdr = (char *)(nd_opt + 1); 2566 bcopy(LLADDR(sdl), lladdr, ifp->if_addrlen); 2567 p += len; 2568 } 2569 } 2570 nolladdropt:; 2571 2572 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2573 2574 /* just to be safe */ 2575 #ifdef M_DECRYPTED /*not openbsd*/ 2576 if (m0->m_flags & M_DECRYPTED) 2577 goto noredhdropt; 2578 #endif 2579 if (p - (u_char *)ip6 > maxlen) 2580 goto noredhdropt; 2581 2582 { 2583 /* redirected header option */ 2584 int len; 2585 struct nd_opt_rd_hdr *nd_opt_rh; 2586 2587 /* 2588 * compute the maximum size for icmp6 redirect header option. 2589 * XXX room for auth header? 2590 */ 2591 len = maxlen - (p - (u_char *)ip6); 2592 len &= ~7; 2593 2594 /* This is just for simplicity. */ 2595 if (m0->m_pkthdr.len != m0->m_len) { 2596 if (m0->m_next) { 2597 m_freem(m0->m_next); 2598 m0->m_next = NULL; 2599 } 2600 m0->m_pkthdr.len = m0->m_len; 2601 } 2602 2603 /* 2604 * Redirected header option spec (RFC2461 4.6.3) talks nothing 2605 * about padding/truncate rule for the original IP packet. 2606 * From the discussion on IPv6imp in Feb 1999, 2607 * the consensus was: 2608 * - "attach as much as possible" is the goal 2609 * - pad if not aligned (original size can be guessed by 2610 * original ip6 header) 2611 * Following code adds the padding if it is simple enough, 2612 * and truncates if not. 2613 */ 2614 if (m0->m_next || m0->m_pkthdr.len != m0->m_len) 2615 panic("assumption failed in %s:%d", __FILE__, 2616 __LINE__); 2617 2618 if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) { 2619 /* not enough room, truncate */ 2620 m0->m_pkthdr.len = m0->m_len = len - 2621 sizeof(*nd_opt_rh); 2622 } else { 2623 /* enough room, pad or truncate */ 2624 size_t extra; 2625 2626 extra = m0->m_pkthdr.len % 8; 2627 if (extra) { 2628 /* pad if easy enough, truncate if not */ 2629 if (8 - extra <= M_TRAILINGSPACE(m0)) { 2630 /* pad */ 2631 m0->m_len += (8 - extra); 2632 m0->m_pkthdr.len += (8 - extra); 2633 } else { 2634 /* truncate */ 2635 m0->m_pkthdr.len -= extra; 2636 m0->m_len -= extra; 2637 } 2638 } 2639 len = m0->m_pkthdr.len + sizeof(*nd_opt_rh); 2640 m0->m_pkthdr.len = m0->m_len = len - 2641 sizeof(*nd_opt_rh); 2642 } 2643 2644 nd_opt_rh = (struct nd_opt_rd_hdr *)p; 2645 bzero(nd_opt_rh, sizeof(*nd_opt_rh)); 2646 nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER; 2647 nd_opt_rh->nd_opt_rh_len = len >> 3; 2648 p += sizeof(*nd_opt_rh); 2649 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2650 2651 /* connect m0 to m */ 2652 m_tag_delete_chain(m0, NULL); 2653 m0->m_flags &= ~M_PKTHDR; 2654 m->m_next = m0; 2655 m->m_pkthdr.len = m->m_len + m0->m_len; 2656 m0 = NULL; 2657 } 2658 noredhdropt:; 2659 if (m0) { 2660 m_freem(m0); 2661 m0 = NULL; 2662 } 2663 2664 /* XXX: clear embedded link IDs in the inner header */ 2665 in6_clearscope(&sip6->ip6_src); 2666 in6_clearscope(&sip6->ip6_dst); 2667 in6_clearscope(&nd_rd->nd_rd_target); 2668 in6_clearscope(&nd_rd->nd_rd_dst); 2669 2670 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr)); 2671 2672 nd_rd->nd_rd_cksum = 0; 2673 nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2674 sizeof(*ip6), ntohs(ip6->ip6_plen)); 2675 2676 /* send the packet to outside... */ 2677 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2678 if (outif) { 2679 icmp6_ifstat_inc(outif, ifs6_out_msg); 2680 icmp6_ifstat_inc(outif, ifs6_out_redirect); 2681 } 2682 icmp6stat.icp6s_outhist[ND_REDIRECT]++; 2683 2684 return; 2685 2686 fail: 2687 if (m) 2688 m_freem(m); 2689 if (m0) 2690 m_freem(m0); 2691 } 2692 2693 /* 2694 * ICMPv6 socket option processing. 2695 */ 2696 int 2697 icmp6_ctloutput(struct socket *so, struct sockopt *sopt) 2698 { 2699 int error = 0; 2700 int optlen; 2701 struct inpcb *inp = sotoinpcb(so); 2702 int level, op, optname; 2703 2704 if (sopt) { 2705 level = sopt->sopt_level; 2706 op = sopt->sopt_dir; 2707 optname = sopt->sopt_name; 2708 optlen = sopt->sopt_valsize; 2709 } else 2710 level = op = optname = optlen = 0; 2711 2712 if (level != IPPROTO_ICMPV6) { 2713 return EINVAL; 2714 } 2715 2716 switch (op) { 2717 case PRCO_SETOPT: 2718 switch (optname) { 2719 case ICMP6_FILTER: 2720 { 2721 struct icmp6_filter *p; 2722 2723 if (optlen != sizeof(*p)) { 2724 error = EMSGSIZE; 2725 break; 2726 } 2727 if (inp->in6p_icmp6filt == NULL) { 2728 error = EINVAL; 2729 break; 2730 } 2731 error = sooptcopyin(sopt, inp->in6p_icmp6filt, optlen, 2732 optlen); 2733 break; 2734 } 2735 2736 default: 2737 error = ENOPROTOOPT; 2738 break; 2739 } 2740 break; 2741 2742 case PRCO_GETOPT: 2743 switch (optname) { 2744 case ICMP6_FILTER: 2745 { 2746 if (inp->in6p_icmp6filt == NULL) { 2747 error = EINVAL; 2748 break; 2749 } 2750 error = sooptcopyout(sopt, inp->in6p_icmp6filt, 2751 sizeof(struct icmp6_filter)); 2752 break; 2753 } 2754 2755 default: 2756 error = ENOPROTOOPT; 2757 break; 2758 } 2759 break; 2760 } 2761 2762 return (error); 2763 } 2764 2765 /* 2766 * Perform rate limit check. 2767 * Returns 0 if it is okay to send the icmp6 packet. 2768 * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate 2769 * limitation. 2770 * 2771 * XXX per-destination/type check necessary? 2772 * 2773 * dst - not used at this moment 2774 * type - not used at this moment 2775 * code - not used at this moment 2776 */ 2777 static int 2778 icmp6_ratelimit(const struct in6_addr *dst, const int type, 2779 const int code) 2780 { 2781 int ret; 2782 2783 ret = 0; /* okay to send */ 2784 2785 /* PPS limit */ 2786 if (!ppsratecheck(&icmp6errppslim_last, &icmp6errpps_count, 2787 icmp6errppslim)) { 2788 /* The packet is subject to rate limit */ 2789 ret++; 2790 } 2791 2792 return ret; 2793 }
Cache object: 3d6f4f937bb7f28241556faa6ece16d0
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