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 #include <sys/vimage.h> 85 86 #include <net/if.h> 87 #include <net/if_dl.h> 88 #include <net/if_types.h> 89 #include <net/route.h> 90 #include <net/vnet.h> 91 92 #include <netinet/in.h> 93 #include <netinet/in_pcb.h> 94 #include <netinet/in_var.h> 95 #include <netinet/ip6.h> 96 #include <netinet/icmp6.h> 97 #include <netinet/tcp_var.h> 98 #include <netinet/vinet.h> 99 100 #include <netinet6/in6_ifattach.h> 101 #include <netinet6/in6_pcb.h> 102 #include <netinet6/ip6protosw.h> 103 #include <netinet6/ip6_var.h> 104 #include <netinet6/scope6_var.h> 105 #include <netinet6/mld6_var.h> 106 #include <netinet6/nd6.h> 107 #include <netinet6/vinet6.h> 108 109 #ifdef IPSEC 110 #include <netipsec/ipsec.h> 111 #include <netipsec/key.h> 112 #endif 113 114 extern struct domain inet6domain; 115 116 #ifdef VIMAGE_GLOBALS 117 extern struct inpcbinfo ripcbinfo; 118 extern struct inpcbhead ripcb; 119 extern int icmp6errppslim; 120 extern int icmp6_nodeinfo; 121 122 struct icmp6stat icmp6stat; 123 static int icmp6errpps_count; 124 static struct timeval icmp6errppslim_last; 125 #endif 126 127 static void icmp6_errcount(struct icmp6errstat *, int, int); 128 static int icmp6_rip6_input(struct mbuf **, int); 129 static int icmp6_ratelimit(const struct in6_addr *, const int, const int); 130 static const char *icmp6_redirect_diag __P((struct in6_addr *, 131 struct in6_addr *, struct in6_addr *)); 132 static struct mbuf *ni6_input(struct mbuf *, int); 133 static struct mbuf *ni6_nametodns(const char *, int, int); 134 static int ni6_dnsmatch(const char *, int, const char *, int); 135 static int ni6_addrs __P((struct icmp6_nodeinfo *, struct mbuf *, 136 struct ifnet **, struct in6_addr *)); 137 static int ni6_store_addrs __P((struct icmp6_nodeinfo *, struct icmp6_nodeinfo *, 138 struct ifnet *, int)); 139 static int icmp6_notify_error(struct mbuf **, int, int, int); 140 141 142 void 143 icmp6_init(void) 144 { 145 INIT_VNET_INET6(curvnet); 146 147 V_icmp6errpps_count = 0; 148 149 mld6_init(); 150 } 151 152 static void 153 icmp6_errcount(struct icmp6errstat *stat, int type, int code) 154 { 155 switch (type) { 156 case ICMP6_DST_UNREACH: 157 switch (code) { 158 case ICMP6_DST_UNREACH_NOROUTE: 159 stat->icp6errs_dst_unreach_noroute++; 160 return; 161 case ICMP6_DST_UNREACH_ADMIN: 162 stat->icp6errs_dst_unreach_admin++; 163 return; 164 case ICMP6_DST_UNREACH_BEYONDSCOPE: 165 stat->icp6errs_dst_unreach_beyondscope++; 166 return; 167 case ICMP6_DST_UNREACH_ADDR: 168 stat->icp6errs_dst_unreach_addr++; 169 return; 170 case ICMP6_DST_UNREACH_NOPORT: 171 stat->icp6errs_dst_unreach_noport++; 172 return; 173 } 174 break; 175 case ICMP6_PACKET_TOO_BIG: 176 stat->icp6errs_packet_too_big++; 177 return; 178 case ICMP6_TIME_EXCEEDED: 179 switch (code) { 180 case ICMP6_TIME_EXCEED_TRANSIT: 181 stat->icp6errs_time_exceed_transit++; 182 return; 183 case ICMP6_TIME_EXCEED_REASSEMBLY: 184 stat->icp6errs_time_exceed_reassembly++; 185 return; 186 } 187 break; 188 case ICMP6_PARAM_PROB: 189 switch (code) { 190 case ICMP6_PARAMPROB_HEADER: 191 stat->icp6errs_paramprob_header++; 192 return; 193 case ICMP6_PARAMPROB_NEXTHEADER: 194 stat->icp6errs_paramprob_nextheader++; 195 return; 196 case ICMP6_PARAMPROB_OPTION: 197 stat->icp6errs_paramprob_option++; 198 return; 199 } 200 break; 201 case ND_REDIRECT: 202 stat->icp6errs_redirect++; 203 return; 204 } 205 stat->icp6errs_unknown++; 206 } 207 208 /* 209 * A wrapper function for icmp6_error() necessary when the erroneous packet 210 * may not contain enough scope zone information. 211 */ 212 void 213 icmp6_error2(struct mbuf *m, int type, int code, int param, 214 struct ifnet *ifp) 215 { 216 INIT_VNET_INET6(curvnet); 217 struct ip6_hdr *ip6; 218 219 if (ifp == NULL) 220 return; 221 222 #ifndef PULLDOWN_TEST 223 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), ); 224 #else 225 if (m->m_len < sizeof(struct ip6_hdr)) { 226 m = m_pullup(m, sizeof(struct ip6_hdr)); 227 if (m == NULL) 228 return; 229 } 230 #endif 231 232 ip6 = mtod(m, struct ip6_hdr *); 233 234 if (in6_setscope(&ip6->ip6_src, ifp, NULL) != 0) 235 return; 236 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0) 237 return; 238 239 icmp6_error(m, type, code, param); 240 } 241 242 /* 243 * Generate an error packet of type error in response to bad IP6 packet. 244 */ 245 void 246 icmp6_error(struct mbuf *m, int type, int code, int param) 247 { 248 INIT_VNET_INET6(curvnet); 249 struct ip6_hdr *oip6, *nip6; 250 struct icmp6_hdr *icmp6; 251 u_int preplen; 252 int off; 253 int nxt; 254 255 V_icmp6stat.icp6s_error++; 256 257 /* count per-type-code statistics */ 258 icmp6_errcount(&V_icmp6stat.icp6s_outerrhist, type, code); 259 260 #ifdef M_DECRYPTED /*not openbsd*/ 261 if (m->m_flags & M_DECRYPTED) { 262 V_icmp6stat.icp6s_canterror++; 263 goto freeit; 264 } 265 #endif 266 267 #ifndef PULLDOWN_TEST 268 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), ); 269 #else 270 if (m->m_len < sizeof(struct ip6_hdr)) { 271 m = m_pullup(m, sizeof(struct ip6_hdr)); 272 if (m == NULL) 273 return; 274 } 275 #endif 276 oip6 = mtod(m, struct ip6_hdr *); 277 278 /* 279 * If the destination address of the erroneous packet is a multicast 280 * address, or the packet was sent using link-layer multicast, 281 * we should basically suppress sending an error (RFC 2463, Section 282 * 2.4). 283 * We have two exceptions (the item e.2 in that section): 284 * - the Pakcet Too Big message can be sent for path MTU discovery. 285 * - the Parameter Problem Message that can be allowed an icmp6 error 286 * in the option type field. This check has been done in 287 * ip6_unknown_opt(), so we can just check the type and code. 288 */ 289 if ((m->m_flags & (M_BCAST|M_MCAST) || 290 IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) && 291 (type != ICMP6_PACKET_TOO_BIG && 292 (type != ICMP6_PARAM_PROB || 293 code != ICMP6_PARAMPROB_OPTION))) 294 goto freeit; 295 296 /* 297 * RFC 2463, 2.4 (e.5): source address check. 298 * XXX: the case of anycast source? 299 */ 300 if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) || 301 IN6_IS_ADDR_MULTICAST(&oip6->ip6_src)) 302 goto freeit; 303 304 /* 305 * If we are about to send ICMPv6 against ICMPv6 error/redirect, 306 * don't do it. 307 */ 308 nxt = -1; 309 off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt); 310 if (off >= 0 && nxt == IPPROTO_ICMPV6) { 311 struct icmp6_hdr *icp; 312 313 #ifndef PULLDOWN_TEST 314 IP6_EXTHDR_CHECK(m, 0, off + sizeof(struct icmp6_hdr), ); 315 icp = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 316 #else 317 IP6_EXTHDR_GET(icp, struct icmp6_hdr *, m, off, 318 sizeof(*icp)); 319 if (icp == NULL) { 320 V_icmp6stat.icp6s_tooshort++; 321 return; 322 } 323 #endif 324 if (icp->icmp6_type < ICMP6_ECHO_REQUEST || 325 icp->icmp6_type == ND_REDIRECT) { 326 /* 327 * ICMPv6 error 328 * Special case: for redirect (which is 329 * informational) we must not send icmp6 error. 330 */ 331 V_icmp6stat.icp6s_canterror++; 332 goto freeit; 333 } else { 334 /* ICMPv6 informational - send the error */ 335 } 336 } else { 337 /* non-ICMPv6 - send the error */ 338 } 339 340 oip6 = mtod(m, struct ip6_hdr *); /* adjust pointer */ 341 342 /* Finally, do rate limitation check. */ 343 if (icmp6_ratelimit(&oip6->ip6_src, type, code)) { 344 V_icmp6stat.icp6s_toofreq++; 345 goto freeit; 346 } 347 348 /* 349 * OK, ICMP6 can be generated. 350 */ 351 352 if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN) 353 m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len); 354 355 preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 356 M_PREPEND(m, preplen, M_DONTWAIT); 357 if (m && m->m_len < preplen) 358 m = m_pullup(m, preplen); 359 if (m == NULL) { 360 nd6log((LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__)); 361 return; 362 } 363 364 nip6 = mtod(m, struct ip6_hdr *); 365 nip6->ip6_src = oip6->ip6_src; 366 nip6->ip6_dst = oip6->ip6_dst; 367 368 in6_clearscope(&oip6->ip6_src); 369 in6_clearscope(&oip6->ip6_dst); 370 371 icmp6 = (struct icmp6_hdr *)(nip6 + 1); 372 icmp6->icmp6_type = type; 373 icmp6->icmp6_code = code; 374 icmp6->icmp6_pptr = htonl((u_int32_t)param); 375 376 /* 377 * icmp6_reflect() is designed to be in the input path. 378 * icmp6_error() can be called from both input and output path, 379 * and if we are in output path rcvif could contain bogus value. 380 * clear m->m_pkthdr.rcvif for safety, we should have enough scope 381 * information in ip header (nip6). 382 */ 383 m->m_pkthdr.rcvif = NULL; 384 385 V_icmp6stat.icp6s_outhist[type]++; 386 icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */ 387 388 return; 389 390 freeit: 391 /* 392 * If we can't tell whether or not we can generate ICMP6, free it. 393 */ 394 m_freem(m); 395 } 396 397 /* 398 * Process a received ICMP6 message. 399 */ 400 int 401 icmp6_input(struct mbuf **mp, int *offp, int proto) 402 { 403 INIT_VNET_INET6(curvnet); 404 INIT_VPROCG(TD_TO_VPROCG(curthread)); /* XXX V_hostname needs this */ 405 struct mbuf *m = *mp, *n; 406 struct ip6_hdr *ip6, *nip6; 407 struct icmp6_hdr *icmp6, *nicmp6; 408 int off = *offp; 409 int icmp6len = m->m_pkthdr.len - *offp; 410 int code, sum, noff; 411 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 412 413 #ifndef PULLDOWN_TEST 414 IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_hdr), IPPROTO_DONE); 415 /* m might change if M_LOOP. So, call mtod after this */ 416 #endif 417 418 /* 419 * Locate icmp6 structure in mbuf, and check 420 * that not corrupted and of at least minimum length 421 */ 422 423 ip6 = mtod(m, struct ip6_hdr *); 424 if (icmp6len < sizeof(struct icmp6_hdr)) { 425 V_icmp6stat.icp6s_tooshort++; 426 goto freeit; 427 } 428 429 /* 430 * calculate the checksum 431 */ 432 #ifndef PULLDOWN_TEST 433 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off); 434 #else 435 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6)); 436 if (icmp6 == NULL) { 437 V_icmp6stat.icp6s_tooshort++; 438 return IPPROTO_DONE; 439 } 440 #endif 441 code = icmp6->icmp6_code; 442 443 if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) { 444 nd6log((LOG_ERR, 445 "ICMP6 checksum error(%d|%x) %s\n", 446 icmp6->icmp6_type, sum, 447 ip6_sprintf(ip6bufs, &ip6->ip6_src))); 448 V_icmp6stat.icp6s_checksum++; 449 goto freeit; 450 } 451 452 if (faithprefix_p != NULL && (*faithprefix_p)(&ip6->ip6_dst)) { 453 /* 454 * Deliver very specific ICMP6 type only. 455 * This is important to deliver TOOBIG. Otherwise PMTUD 456 * will not work. 457 */ 458 switch (icmp6->icmp6_type) { 459 case ICMP6_DST_UNREACH: 460 case ICMP6_PACKET_TOO_BIG: 461 case ICMP6_TIME_EXCEEDED: 462 break; 463 default: 464 goto freeit; 465 } 466 } 467 468 V_icmp6stat.icp6s_inhist[icmp6->icmp6_type]++; 469 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_msg); 470 if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK) 471 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_error); 472 473 switch (icmp6->icmp6_type) { 474 case ICMP6_DST_UNREACH: 475 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_dstunreach); 476 switch (code) { 477 case ICMP6_DST_UNREACH_NOROUTE: 478 code = PRC_UNREACH_NET; 479 break; 480 case ICMP6_DST_UNREACH_ADMIN: 481 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_adminprohib); 482 code = PRC_UNREACH_PROTOCOL; /* is this a good code? */ 483 break; 484 case ICMP6_DST_UNREACH_ADDR: 485 code = PRC_HOSTDEAD; 486 break; 487 case ICMP6_DST_UNREACH_BEYONDSCOPE: 488 /* I mean "source address was incorrect." */ 489 code = PRC_PARAMPROB; 490 break; 491 case ICMP6_DST_UNREACH_NOPORT: 492 code = PRC_UNREACH_PORT; 493 break; 494 default: 495 goto badcode; 496 } 497 goto deliver; 498 break; 499 500 case ICMP6_PACKET_TOO_BIG: 501 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_pkttoobig); 502 503 /* validation is made in icmp6_mtudisc_update */ 504 505 code = PRC_MSGSIZE; 506 507 /* 508 * Updating the path MTU will be done after examining 509 * intermediate extension headers. 510 */ 511 goto deliver; 512 break; 513 514 case ICMP6_TIME_EXCEEDED: 515 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_timeexceed); 516 switch (code) { 517 case ICMP6_TIME_EXCEED_TRANSIT: 518 code = PRC_TIMXCEED_INTRANS; 519 break; 520 case ICMP6_TIME_EXCEED_REASSEMBLY: 521 code = PRC_TIMXCEED_REASS; 522 break; 523 default: 524 goto badcode; 525 } 526 goto deliver; 527 break; 528 529 case ICMP6_PARAM_PROB: 530 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_paramprob); 531 switch (code) { 532 case ICMP6_PARAMPROB_NEXTHEADER: 533 code = PRC_UNREACH_PROTOCOL; 534 break; 535 case ICMP6_PARAMPROB_HEADER: 536 case ICMP6_PARAMPROB_OPTION: 537 code = PRC_PARAMPROB; 538 break; 539 default: 540 goto badcode; 541 } 542 goto deliver; 543 break; 544 545 case ICMP6_ECHO_REQUEST: 546 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_echo); 547 if (code != 0) 548 goto badcode; 549 if ((n = m_copy(m, 0, M_COPYALL)) == NULL) { 550 /* Give up remote */ 551 break; 552 } 553 if ((n->m_flags & M_EXT) != 0 554 || n->m_len < off + sizeof(struct icmp6_hdr)) { 555 struct mbuf *n0 = n; 556 const int maxlen = sizeof(*nip6) + sizeof(*nicmp6); 557 int n0len; 558 559 MGETHDR(n, M_DONTWAIT, n0->m_type); 560 n0len = n0->m_pkthdr.len; /* save for use below */ 561 if (n) 562 M_MOVE_PKTHDR(n, n0); 563 if (n && maxlen >= MHLEN) { 564 MCLGET(n, M_DONTWAIT); 565 if ((n->m_flags & M_EXT) == 0) { 566 m_free(n); 567 n = NULL; 568 } 569 } 570 if (n == NULL) { 571 /* Give up remote */ 572 m_freem(n0); 573 break; 574 } 575 /* 576 * Copy IPv6 and ICMPv6 only. 577 */ 578 nip6 = mtod(n, struct ip6_hdr *); 579 bcopy(ip6, nip6, sizeof(struct ip6_hdr)); 580 nicmp6 = (struct icmp6_hdr *)(nip6 + 1); 581 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr)); 582 noff = sizeof(struct ip6_hdr); 583 /* new mbuf contains only ipv6+icmpv6 headers */ 584 n->m_len = noff + sizeof(struct icmp6_hdr); 585 /* 586 * Adjust mbuf. ip6_plen will be adjusted in 587 * ip6_output(). 588 */ 589 m_adj(n0, off + sizeof(struct icmp6_hdr)); 590 /* recalculate complete packet size */ 591 n->m_pkthdr.len = n0len + (noff - off); 592 n->m_next = n0; 593 } else { 594 nip6 = mtod(n, struct ip6_hdr *); 595 IP6_EXTHDR_GET(nicmp6, struct icmp6_hdr *, n, off, 596 sizeof(*nicmp6)); 597 noff = off; 598 } 599 nicmp6->icmp6_type = ICMP6_ECHO_REPLY; 600 nicmp6->icmp6_code = 0; 601 if (n) { 602 V_icmp6stat.icp6s_reflect++; 603 V_icmp6stat.icp6s_outhist[ICMP6_ECHO_REPLY]++; 604 icmp6_reflect(n, noff); 605 } 606 break; 607 608 case ICMP6_ECHO_REPLY: 609 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_echoreply); 610 if (code != 0) 611 goto badcode; 612 break; 613 614 case MLD_LISTENER_QUERY: 615 case MLD_LISTENER_REPORT: 616 if (icmp6len < sizeof(struct mld_hdr)) 617 goto badlen; 618 if (icmp6->icmp6_type == MLD_LISTENER_QUERY) /* XXX: ugly... */ 619 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mldquery); 620 else 621 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mldreport); 622 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 623 /* give up local */ 624 mld6_input(m, off); 625 m = NULL; 626 goto freeit; 627 } 628 mld6_input(n, off); 629 /* m stays. */ 630 break; 631 632 case MLD_LISTENER_DONE: 633 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mlddone); 634 if (icmp6len < sizeof(struct mld_hdr)) /* necessary? */ 635 goto badlen; 636 break; /* nothing to be done in kernel */ 637 638 case MLD_MTRACE_RESP: 639 case MLD_MTRACE: 640 /* XXX: these two are experimental. not officially defined. */ 641 /* XXX: per-interface statistics? */ 642 break; /* just pass it to applications */ 643 644 case ICMP6_WRUREQUEST: /* ICMP6_FQDN_QUERY */ 645 { 646 enum { WRU, FQDN } mode; 647 648 if (!V_icmp6_nodeinfo) 649 break; 650 651 if (icmp6len == sizeof(struct icmp6_hdr) + 4) 652 mode = WRU; 653 else if (icmp6len >= sizeof(struct icmp6_nodeinfo)) 654 mode = FQDN; 655 else 656 goto badlen; 657 658 #define hostnamelen strlen(V_hostname) 659 if (mode == FQDN) { 660 #ifndef PULLDOWN_TEST 661 IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_nodeinfo), 662 IPPROTO_DONE); 663 #endif 664 n = m_copy(m, 0, M_COPYALL); 665 if (n) 666 n = ni6_input(n, off); 667 /* XXX meaningless if n == NULL */ 668 noff = sizeof(struct ip6_hdr); 669 } else { 670 u_char *p; 671 int maxlen, maxhlen; 672 673 /* 674 * XXX: this combination of flags is pointless, 675 * but should we keep this for compatibility? 676 */ 677 if ((V_icmp6_nodeinfo & 5) != 5) 678 break; 679 680 if (code != 0) 681 goto badcode; 682 maxlen = sizeof(*nip6) + sizeof(*nicmp6) + 4; 683 if (maxlen >= MCLBYTES) { 684 /* Give up remote */ 685 break; 686 } 687 MGETHDR(n, M_DONTWAIT, m->m_type); 688 if (n && maxlen > MHLEN) { 689 MCLGET(n, M_DONTWAIT); 690 if ((n->m_flags & M_EXT) == 0) { 691 m_free(n); 692 n = NULL; 693 } 694 } 695 if (n && !m_dup_pkthdr(n, m, M_DONTWAIT)) { 696 /* 697 * Previous code did a blind M_COPY_PKTHDR 698 * and said "just for rcvif". If true, then 699 * we could tolerate the dup failing (due to 700 * the deep copy of the tag chain). For now 701 * be conservative and just fail. 702 */ 703 m_free(n); 704 n = NULL; 705 } 706 if (n == NULL) { 707 /* Give up remote */ 708 break; 709 } 710 n->m_pkthdr.rcvif = NULL; 711 n->m_len = 0; 712 maxhlen = M_TRAILINGSPACE(n) - maxlen; 713 mtx_lock(&hostname_mtx); 714 if (maxhlen > hostnamelen) 715 maxhlen = hostnamelen; 716 /* 717 * Copy IPv6 and ICMPv6 only. 718 */ 719 nip6 = mtod(n, struct ip6_hdr *); 720 bcopy(ip6, nip6, sizeof(struct ip6_hdr)); 721 nicmp6 = (struct icmp6_hdr *)(nip6 + 1); 722 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr)); 723 p = (u_char *)(nicmp6 + 1); 724 bzero(p, 4); 725 bcopy(V_hostname, p + 4, maxhlen); /* meaningless TTL */ 726 mtx_unlock(&hostname_mtx); 727 noff = sizeof(struct ip6_hdr); 728 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + 729 sizeof(struct icmp6_hdr) + 4 + maxhlen; 730 nicmp6->icmp6_type = ICMP6_WRUREPLY; 731 nicmp6->icmp6_code = 0; 732 } 733 #undef hostnamelen 734 if (n) { 735 V_icmp6stat.icp6s_reflect++; 736 V_icmp6stat.icp6s_outhist[ICMP6_WRUREPLY]++; 737 icmp6_reflect(n, noff); 738 } 739 break; 740 } 741 742 case ICMP6_WRUREPLY: 743 if (code != 0) 744 goto badcode; 745 break; 746 747 case ND_ROUTER_SOLICIT: 748 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_routersolicit); 749 if (code != 0) 750 goto badcode; 751 if (icmp6len < sizeof(struct nd_router_solicit)) 752 goto badlen; 753 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 754 /* give up local */ 755 nd6_rs_input(m, off, icmp6len); 756 m = NULL; 757 goto freeit; 758 } 759 nd6_rs_input(n, off, icmp6len); 760 /* m stays. */ 761 break; 762 763 case ND_ROUTER_ADVERT: 764 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_routeradvert); 765 if (code != 0) 766 goto badcode; 767 if (icmp6len < sizeof(struct nd_router_advert)) 768 goto badlen; 769 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 770 /* give up local */ 771 nd6_ra_input(m, off, icmp6len); 772 m = NULL; 773 goto freeit; 774 } 775 nd6_ra_input(n, off, icmp6len); 776 /* m stays. */ 777 break; 778 779 case ND_NEIGHBOR_SOLICIT: 780 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_neighborsolicit); 781 if (code != 0) 782 goto badcode; 783 if (icmp6len < sizeof(struct nd_neighbor_solicit)) 784 goto badlen; 785 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 786 /* give up local */ 787 nd6_ns_input(m, off, icmp6len); 788 m = NULL; 789 goto freeit; 790 } 791 nd6_ns_input(n, off, icmp6len); 792 /* m stays. */ 793 break; 794 795 case ND_NEIGHBOR_ADVERT: 796 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_neighboradvert); 797 if (code != 0) 798 goto badcode; 799 if (icmp6len < sizeof(struct nd_neighbor_advert)) 800 goto badlen; 801 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 802 /* give up local */ 803 nd6_na_input(m, off, icmp6len); 804 m = NULL; 805 goto freeit; 806 } 807 nd6_na_input(n, off, icmp6len); 808 /* m stays. */ 809 break; 810 811 case ND_REDIRECT: 812 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_redirect); 813 if (code != 0) 814 goto badcode; 815 if (icmp6len < sizeof(struct nd_redirect)) 816 goto badlen; 817 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 818 /* give up local */ 819 icmp6_redirect_input(m, off); 820 m = NULL; 821 goto freeit; 822 } 823 icmp6_redirect_input(n, off); 824 /* m stays. */ 825 break; 826 827 case ICMP6_ROUTER_RENUMBERING: 828 if (code != ICMP6_ROUTER_RENUMBERING_COMMAND && 829 code != ICMP6_ROUTER_RENUMBERING_RESULT) 830 goto badcode; 831 if (icmp6len < sizeof(struct icmp6_router_renum)) 832 goto badlen; 833 break; 834 835 default: 836 nd6log((LOG_DEBUG, 837 "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n", 838 icmp6->icmp6_type, ip6_sprintf(ip6bufs, &ip6->ip6_src), 839 ip6_sprintf(ip6bufd, &ip6->ip6_dst), 840 m->m_pkthdr.rcvif ? m->m_pkthdr.rcvif->if_index : 0)); 841 if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) { 842 /* ICMPv6 error: MUST deliver it by spec... */ 843 code = PRC_NCMDS; 844 /* deliver */ 845 } else { 846 /* ICMPv6 informational: MUST not deliver */ 847 break; 848 } 849 deliver: 850 if (icmp6_notify_error(&m, off, icmp6len, code)) { 851 /* In this case, m should've been freed. */ 852 return (IPPROTO_DONE); 853 } 854 break; 855 856 badcode: 857 V_icmp6stat.icp6s_badcode++; 858 break; 859 860 badlen: 861 V_icmp6stat.icp6s_badlen++; 862 break; 863 } 864 865 /* deliver the packet to appropriate sockets */ 866 icmp6_rip6_input(&m, *offp); 867 868 return IPPROTO_DONE; 869 870 freeit: 871 m_freem(m); 872 return IPPROTO_DONE; 873 } 874 875 static int 876 icmp6_notify_error(struct mbuf **mp, int off, int icmp6len, int code) 877 { 878 INIT_VNET_INET6(curvnet); 879 struct mbuf *m = *mp; 880 struct icmp6_hdr *icmp6; 881 struct ip6_hdr *eip6; 882 u_int32_t notifymtu; 883 struct sockaddr_in6 icmp6src, icmp6dst; 884 885 if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) { 886 V_icmp6stat.icp6s_tooshort++; 887 goto freeit; 888 } 889 #ifndef PULLDOWN_TEST 890 IP6_EXTHDR_CHECK(m, off, 891 sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr), -1); 892 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 893 #else 894 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, 895 sizeof(*icmp6) + sizeof(struct ip6_hdr)); 896 if (icmp6 == NULL) { 897 V_icmp6stat.icp6s_tooshort++; 898 return (-1); 899 } 900 #endif 901 eip6 = (struct ip6_hdr *)(icmp6 + 1); 902 903 /* Detect the upper level protocol */ 904 { 905 void (*ctlfunc)(int, struct sockaddr *, void *); 906 u_int8_t nxt = eip6->ip6_nxt; 907 int eoff = off + sizeof(struct icmp6_hdr) + 908 sizeof(struct ip6_hdr); 909 struct ip6ctlparam ip6cp; 910 struct in6_addr *finaldst = NULL; 911 int icmp6type = icmp6->icmp6_type; 912 struct ip6_frag *fh; 913 struct ip6_rthdr *rth; 914 struct ip6_rthdr0 *rth0; 915 int rthlen; 916 917 while (1) { /* XXX: should avoid infinite loop explicitly? */ 918 struct ip6_ext *eh; 919 920 switch (nxt) { 921 case IPPROTO_HOPOPTS: 922 case IPPROTO_DSTOPTS: 923 case IPPROTO_AH: 924 #ifndef PULLDOWN_TEST 925 IP6_EXTHDR_CHECK(m, 0, 926 eoff + sizeof(struct ip6_ext), -1); 927 eh = (struct ip6_ext *)(mtod(m, caddr_t) + eoff); 928 #else 929 IP6_EXTHDR_GET(eh, struct ip6_ext *, m, 930 eoff, sizeof(*eh)); 931 if (eh == NULL) { 932 V_icmp6stat.icp6s_tooshort++; 933 return (-1); 934 } 935 #endif 936 937 if (nxt == IPPROTO_AH) 938 eoff += (eh->ip6e_len + 2) << 2; 939 else 940 eoff += (eh->ip6e_len + 1) << 3; 941 nxt = eh->ip6e_nxt; 942 break; 943 case IPPROTO_ROUTING: 944 /* 945 * When the erroneous packet contains a 946 * routing header, we should examine the 947 * header to determine the final destination. 948 * Otherwise, we can't properly update 949 * information that depends on the final 950 * destination (e.g. path MTU). 951 */ 952 #ifndef PULLDOWN_TEST 953 IP6_EXTHDR_CHECK(m, 0, eoff + sizeof(*rth), -1); 954 rth = (struct ip6_rthdr *) 955 (mtod(m, caddr_t) + eoff); 956 #else 957 IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m, 958 eoff, sizeof(*rth)); 959 if (rth == NULL) { 960 V_icmp6stat.icp6s_tooshort++; 961 return (-1); 962 } 963 #endif 964 rthlen = (rth->ip6r_len + 1) << 3; 965 /* 966 * XXX: currently there is no 967 * officially defined type other 968 * than type-0. 969 * Note that if the segment left field 970 * is 0, all intermediate hops must 971 * have been passed. 972 */ 973 if (rth->ip6r_segleft && 974 rth->ip6r_type == IPV6_RTHDR_TYPE_0) { 975 int hops; 976 977 #ifndef PULLDOWN_TEST 978 IP6_EXTHDR_CHECK(m, 0, eoff + rthlen, -1); 979 rth0 = (struct ip6_rthdr0 *) 980 (mtod(m, caddr_t) + eoff); 981 #else 982 IP6_EXTHDR_GET(rth0, 983 struct ip6_rthdr0 *, m, 984 eoff, rthlen); 985 if (rth0 == NULL) { 986 V_icmp6stat.icp6s_tooshort++; 987 return (-1); 988 } 989 #endif 990 /* just ignore a bogus header */ 991 if ((rth0->ip6r0_len % 2) == 0 && 992 (hops = rth0->ip6r0_len/2)) 993 finaldst = (struct in6_addr *)(rth0 + 1) + (hops - 1); 994 } 995 eoff += rthlen; 996 nxt = rth->ip6r_nxt; 997 break; 998 case IPPROTO_FRAGMENT: 999 #ifndef PULLDOWN_TEST 1000 IP6_EXTHDR_CHECK(m, 0, eoff + 1001 sizeof(struct ip6_frag), -1); 1002 fh = (struct ip6_frag *)(mtod(m, caddr_t) + 1003 eoff); 1004 #else 1005 IP6_EXTHDR_GET(fh, struct ip6_frag *, m, 1006 eoff, sizeof(*fh)); 1007 if (fh == NULL) { 1008 V_icmp6stat.icp6s_tooshort++; 1009 return (-1); 1010 } 1011 #endif 1012 /* 1013 * Data after a fragment header is meaningless 1014 * unless it is the first fragment, but 1015 * we'll go to the notify label for path MTU 1016 * discovery. 1017 */ 1018 if (fh->ip6f_offlg & IP6F_OFF_MASK) 1019 goto notify; 1020 1021 eoff += sizeof(struct ip6_frag); 1022 nxt = fh->ip6f_nxt; 1023 break; 1024 default: 1025 /* 1026 * This case includes ESP and the No Next 1027 * Header. In such cases going to the notify 1028 * label does not have any meaning 1029 * (i.e. ctlfunc will be NULL), but we go 1030 * anyway since we might have to update 1031 * path MTU information. 1032 */ 1033 goto notify; 1034 } 1035 } 1036 notify: 1037 #ifndef PULLDOWN_TEST 1038 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 1039 #else 1040 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, 1041 sizeof(*icmp6) + sizeof(struct ip6_hdr)); 1042 if (icmp6 == NULL) { 1043 V_icmp6stat.icp6s_tooshort++; 1044 return (-1); 1045 } 1046 #endif 1047 1048 /* 1049 * retrieve parameters from the inner IPv6 header, and convert 1050 * them into sockaddr structures. 1051 * XXX: there is no guarantee that the source or destination 1052 * addresses of the inner packet are in the same scope as 1053 * the addresses of the icmp packet. But there is no other 1054 * way to determine the zone. 1055 */ 1056 eip6 = (struct ip6_hdr *)(icmp6 + 1); 1057 1058 bzero(&icmp6dst, sizeof(icmp6dst)); 1059 icmp6dst.sin6_len = sizeof(struct sockaddr_in6); 1060 icmp6dst.sin6_family = AF_INET6; 1061 if (finaldst == NULL) 1062 icmp6dst.sin6_addr = eip6->ip6_dst; 1063 else 1064 icmp6dst.sin6_addr = *finaldst; 1065 if (in6_setscope(&icmp6dst.sin6_addr, m->m_pkthdr.rcvif, NULL)) 1066 goto freeit; 1067 bzero(&icmp6src, sizeof(icmp6src)); 1068 icmp6src.sin6_len = sizeof(struct sockaddr_in6); 1069 icmp6src.sin6_family = AF_INET6; 1070 icmp6src.sin6_addr = eip6->ip6_src; 1071 if (in6_setscope(&icmp6src.sin6_addr, m->m_pkthdr.rcvif, NULL)) 1072 goto freeit; 1073 icmp6src.sin6_flowinfo = 1074 (eip6->ip6_flow & IPV6_FLOWLABEL_MASK); 1075 1076 if (finaldst == NULL) 1077 finaldst = &eip6->ip6_dst; 1078 ip6cp.ip6c_m = m; 1079 ip6cp.ip6c_icmp6 = icmp6; 1080 ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1); 1081 ip6cp.ip6c_off = eoff; 1082 ip6cp.ip6c_finaldst = finaldst; 1083 ip6cp.ip6c_src = &icmp6src; 1084 ip6cp.ip6c_nxt = nxt; 1085 1086 if (icmp6type == ICMP6_PACKET_TOO_BIG) { 1087 notifymtu = ntohl(icmp6->icmp6_mtu); 1088 ip6cp.ip6c_cmdarg = (void *)¬ifymtu; 1089 icmp6_mtudisc_update(&ip6cp, 1); /*XXX*/ 1090 } 1091 1092 ctlfunc = (void (*)(int, struct sockaddr *, void *)) 1093 (inet6sw[ip6_protox[nxt]].pr_ctlinput); 1094 if (ctlfunc) { 1095 (void) (*ctlfunc)(code, (struct sockaddr *)&icmp6dst, 1096 &ip6cp); 1097 } 1098 } 1099 *mp = m; 1100 return (0); 1101 1102 freeit: 1103 m_freem(m); 1104 return (-1); 1105 } 1106 1107 void 1108 icmp6_mtudisc_update(struct ip6ctlparam *ip6cp, int validated) 1109 { 1110 INIT_VNET_INET6(curvnet); 1111 struct in6_addr *dst = ip6cp->ip6c_finaldst; 1112 struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6; 1113 struct mbuf *m = ip6cp->ip6c_m; /* will be necessary for scope issue */ 1114 u_int mtu = ntohl(icmp6->icmp6_mtu); 1115 struct in_conninfo inc; 1116 1117 #if 0 1118 /* 1119 * RFC2460 section 5, last paragraph. 1120 * even though minimum link MTU for IPv6 is IPV6_MMTU, 1121 * we may see ICMPv6 too big with mtu < IPV6_MMTU 1122 * due to packet translator in the middle. 1123 * see ip6_output() and ip6_getpmtu() "alwaysfrag" case for 1124 * special handling. 1125 */ 1126 if (mtu < IPV6_MMTU) 1127 return; 1128 #endif 1129 1130 /* 1131 * we reject ICMPv6 too big with abnormally small value. 1132 * XXX what is the good definition of "abnormally small"? 1133 */ 1134 if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8) 1135 return; 1136 1137 if (!validated) 1138 return; 1139 1140 /* 1141 * In case the suggested mtu is less than IPV6_MMTU, we 1142 * only need to remember that it was for above mentioned 1143 * "alwaysfrag" case. 1144 * Try to be as close to the spec as possible. 1145 */ 1146 if (mtu < IPV6_MMTU) 1147 mtu = IPV6_MMTU - 8; 1148 1149 bzero(&inc, sizeof(inc)); 1150 inc.inc_flags = 1; /* IPv6 */ 1151 inc.inc6_faddr = *dst; 1152 if (in6_setscope(&inc.inc6_faddr, m->m_pkthdr.rcvif, NULL)) 1153 return; 1154 1155 if (mtu < tcp_maxmtu6(&inc, NULL)) { 1156 tcp_hc_updatemtu(&inc, mtu); 1157 V_icmp6stat.icp6s_pmtuchg++; 1158 } 1159 } 1160 1161 /* 1162 * Process a Node Information Query packet, based on 1163 * draft-ietf-ipngwg-icmp-name-lookups-07. 1164 * 1165 * Spec incompatibilities: 1166 * - IPv6 Subject address handling 1167 * - IPv4 Subject address handling support missing 1168 * - Proxy reply (answer even if it's not for me) 1169 * - joins NI group address at in6_ifattach() time only, does not cope 1170 * with hostname changes by sethostname(3) 1171 */ 1172 #define hostnamelen strlen(V_hostname) 1173 static struct mbuf * 1174 ni6_input(struct mbuf *m, int off) 1175 { 1176 INIT_VNET_INET6(curvnet); 1177 INIT_VPROCG(TD_TO_VPROCG(curthread)); /* XXX V_hostname needs this */ 1178 struct icmp6_nodeinfo *ni6, *nni6; 1179 struct mbuf *n = NULL; 1180 u_int16_t qtype; 1181 int subjlen; 1182 int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); 1183 struct ni_reply_fqdn *fqdn; 1184 int addrs; /* for NI_QTYPE_NODEADDR */ 1185 struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */ 1186 struct in6_addr in6_subj; /* subject address */ 1187 struct ip6_hdr *ip6; 1188 int oldfqdn = 0; /* if 1, return pascal string (03 draft) */ 1189 char *subj = NULL; 1190 struct in6_ifaddr *ia6 = NULL; 1191 1192 ip6 = mtod(m, struct ip6_hdr *); 1193 #ifndef PULLDOWN_TEST 1194 ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off); 1195 #else 1196 IP6_EXTHDR_GET(ni6, struct icmp6_nodeinfo *, m, off, sizeof(*ni6)); 1197 if (ni6 == NULL) { 1198 /* m is already reclaimed */ 1199 return (NULL); 1200 } 1201 #endif 1202 1203 /* 1204 * Validate IPv6 source address. 1205 * The default configuration MUST be to refuse answering queries from 1206 * global-scope addresses according to RFC4602. 1207 * Notes: 1208 * - it's not very clear what "refuse" means; this implementation 1209 * simply drops it. 1210 * - it's not very easy to identify global-scope (unicast) addresses 1211 * since there are many prefixes for them. It should be safer 1212 * and in practice sufficient to check "all" but loopback and 1213 * link-local (note that site-local unicast was deprecated and 1214 * ULA is defined as global scope-wise) 1215 */ 1216 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_GLOBALOK) == 0 && 1217 !IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) && 1218 !IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) 1219 goto bad; 1220 1221 /* 1222 * Validate IPv6 destination address. 1223 * 1224 * The Responder must discard the Query without further processing 1225 * unless it is one of the Responder's unicast or anycast addresses, or 1226 * a link-local scope multicast address which the Responder has joined. 1227 * [RFC4602, Section 5.] 1228 */ 1229 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 1230 if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst)) 1231 goto bad; 1232 /* else it's a link-local multicast, fine */ 1233 } else { /* unicast or anycast */ 1234 if ((ia6 = ip6_getdstifaddr(m)) == NULL) 1235 goto bad; /* XXX impossible */ 1236 1237 if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) && 1238 !(V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK)) { 1239 nd6log((LOG_DEBUG, "ni6_input: ignore node info to " 1240 "a temporary address in %s:%d", 1241 __FILE__, __LINE__)); 1242 goto bad; 1243 } 1244 } 1245 1246 /* validate query Subject field. */ 1247 qtype = ntohs(ni6->ni_qtype); 1248 subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo); 1249 switch (qtype) { 1250 case NI_QTYPE_NOOP: 1251 case NI_QTYPE_SUPTYPES: 1252 /* 07 draft */ 1253 if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0) 1254 break; 1255 /* FALLTHROUGH */ 1256 case NI_QTYPE_FQDN: 1257 case NI_QTYPE_NODEADDR: 1258 case NI_QTYPE_IPV4ADDR: 1259 switch (ni6->ni_code) { 1260 case ICMP6_NI_SUBJ_IPV6: 1261 #if ICMP6_NI_SUBJ_IPV6 != 0 1262 case 0: 1263 #endif 1264 /* 1265 * backward compatibility - try to accept 03 draft 1266 * format, where no Subject is present. 1267 */ 1268 if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 && 1269 subjlen == 0) { 1270 oldfqdn++; 1271 break; 1272 } 1273 #if ICMP6_NI_SUBJ_IPV6 != 0 1274 if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6) 1275 goto bad; 1276 #endif 1277 1278 if (subjlen != sizeof(struct in6_addr)) 1279 goto bad; 1280 1281 /* 1282 * Validate Subject address. 1283 * 1284 * Not sure what exactly "address belongs to the node" 1285 * means in the spec, is it just unicast, or what? 1286 * 1287 * At this moment we consider Subject address as 1288 * "belong to the node" if the Subject address equals 1289 * to the IPv6 destination address; validation for 1290 * IPv6 destination address should have done enough 1291 * check for us. 1292 * 1293 * We do not do proxy at this moment. 1294 */ 1295 /* m_pulldown instead of copy? */ 1296 m_copydata(m, off + sizeof(struct icmp6_nodeinfo), 1297 subjlen, (caddr_t)&in6_subj); 1298 if (in6_setscope(&in6_subj, m->m_pkthdr.rcvif, NULL)) 1299 goto bad; 1300 1301 subj = (char *)&in6_subj; 1302 if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &in6_subj)) 1303 break; 1304 1305 /* 1306 * XXX if we are to allow other cases, we should really 1307 * be careful about scope here. 1308 * basically, we should disallow queries toward IPv6 1309 * destination X with subject Y, 1310 * if scope(X) > scope(Y). 1311 * if we allow scope(X) > scope(Y), it will result in 1312 * information leakage across scope boundary. 1313 */ 1314 goto bad; 1315 1316 case ICMP6_NI_SUBJ_FQDN: 1317 /* 1318 * Validate Subject name with gethostname(3). 1319 * 1320 * The behavior may need some debate, since: 1321 * - we are not sure if the node has FQDN as 1322 * hostname (returned by gethostname(3)). 1323 * - the code does wildcard match for truncated names. 1324 * however, we are not sure if we want to perform 1325 * wildcard match, if gethostname(3) side has 1326 * truncated hostname. 1327 */ 1328 mtx_lock(&hostname_mtx); 1329 n = ni6_nametodns(V_hostname, hostnamelen, 0); 1330 mtx_unlock(&hostname_mtx); 1331 if (!n || n->m_next || n->m_len == 0) 1332 goto bad; 1333 IP6_EXTHDR_GET(subj, char *, m, 1334 off + sizeof(struct icmp6_nodeinfo), subjlen); 1335 if (subj == NULL) 1336 goto bad; 1337 if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *), 1338 n->m_len)) { 1339 goto bad; 1340 } 1341 m_freem(n); 1342 n = NULL; 1343 break; 1344 1345 case ICMP6_NI_SUBJ_IPV4: /* XXX: to be implemented? */ 1346 default: 1347 goto bad; 1348 } 1349 break; 1350 } 1351 1352 /* refuse based on configuration. XXX ICMP6_NI_REFUSED? */ 1353 switch (qtype) { 1354 case NI_QTYPE_FQDN: 1355 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_FQDNOK) == 0) 1356 goto bad; 1357 break; 1358 case NI_QTYPE_NODEADDR: 1359 case NI_QTYPE_IPV4ADDR: 1360 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_NODEADDROK) == 0) 1361 goto bad; 1362 break; 1363 } 1364 1365 /* guess reply length */ 1366 switch (qtype) { 1367 case NI_QTYPE_NOOP: 1368 break; /* no reply data */ 1369 case NI_QTYPE_SUPTYPES: 1370 replylen += sizeof(u_int32_t); 1371 break; 1372 case NI_QTYPE_FQDN: 1373 /* XXX will append an mbuf */ 1374 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); 1375 break; 1376 case NI_QTYPE_NODEADDR: 1377 addrs = ni6_addrs(ni6, m, &ifp, (struct in6_addr *)subj); 1378 if ((replylen += addrs * (sizeof(struct in6_addr) + 1379 sizeof(u_int32_t))) > MCLBYTES) 1380 replylen = MCLBYTES; /* XXX: will truncate pkt later */ 1381 break; 1382 case NI_QTYPE_IPV4ADDR: 1383 /* unsupported - should respond with unknown Qtype? */ 1384 break; 1385 default: 1386 /* 1387 * XXX: We must return a reply with the ICMP6 code 1388 * `unknown Qtype' in this case. However we regard the case 1389 * as an FQDN query for backward compatibility. 1390 * Older versions set a random value to this field, 1391 * so it rarely varies in the defined qtypes. 1392 * But the mechanism is not reliable... 1393 * maybe we should obsolete older versions. 1394 */ 1395 qtype = NI_QTYPE_FQDN; 1396 /* XXX will append an mbuf */ 1397 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); 1398 oldfqdn++; 1399 break; 1400 } 1401 1402 /* allocate an mbuf to reply. */ 1403 MGETHDR(n, M_DONTWAIT, m->m_type); 1404 if (n == NULL) { 1405 m_freem(m); 1406 return (NULL); 1407 } 1408 M_MOVE_PKTHDR(n, m); /* just for recvif */ 1409 if (replylen > MHLEN) { 1410 if (replylen > MCLBYTES) { 1411 /* 1412 * XXX: should we try to allocate more? But MCLBYTES 1413 * is probably much larger than IPV6_MMTU... 1414 */ 1415 goto bad; 1416 } 1417 MCLGET(n, M_DONTWAIT); 1418 if ((n->m_flags & M_EXT) == 0) { 1419 goto bad; 1420 } 1421 } 1422 n->m_pkthdr.len = n->m_len = replylen; 1423 1424 /* copy mbuf header and IPv6 + Node Information base headers */ 1425 bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr)); 1426 nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1); 1427 bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo)); 1428 1429 /* qtype dependent procedure */ 1430 switch (qtype) { 1431 case NI_QTYPE_NOOP: 1432 nni6->ni_code = ICMP6_NI_SUCCESS; 1433 nni6->ni_flags = 0; 1434 break; 1435 case NI_QTYPE_SUPTYPES: 1436 { 1437 u_int32_t v; 1438 nni6->ni_code = ICMP6_NI_SUCCESS; 1439 nni6->ni_flags = htons(0x0000); /* raw bitmap */ 1440 /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */ 1441 v = (u_int32_t)htonl(0x0000000f); 1442 bcopy(&v, nni6 + 1, sizeof(u_int32_t)); 1443 break; 1444 } 1445 case NI_QTYPE_FQDN: 1446 nni6->ni_code = ICMP6_NI_SUCCESS; 1447 fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) + 1448 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo)); 1449 nni6->ni_flags = 0; /* XXX: meaningless TTL */ 1450 fqdn->ni_fqdn_ttl = 0; /* ditto. */ 1451 /* 1452 * XXX do we really have FQDN in variable "hostname"? 1453 */ 1454 mtx_lock(&hostname_mtx); 1455 n->m_next = ni6_nametodns(V_hostname, hostnamelen, oldfqdn); 1456 mtx_unlock(&hostname_mtx); 1457 if (n->m_next == NULL) 1458 goto bad; 1459 /* XXX we assume that n->m_next is not a chain */ 1460 if (n->m_next->m_next != NULL) 1461 goto bad; 1462 n->m_pkthdr.len += n->m_next->m_len; 1463 break; 1464 case NI_QTYPE_NODEADDR: 1465 { 1466 int lenlim, copied; 1467 1468 nni6->ni_code = ICMP6_NI_SUCCESS; 1469 n->m_pkthdr.len = n->m_len = 1470 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); 1471 lenlim = M_TRAILINGSPACE(n); 1472 copied = ni6_store_addrs(ni6, nni6, ifp, lenlim); 1473 /* XXX: reset mbuf length */ 1474 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + 1475 sizeof(struct icmp6_nodeinfo) + copied; 1476 break; 1477 } 1478 default: 1479 break; /* XXX impossible! */ 1480 } 1481 1482 nni6->ni_type = ICMP6_NI_REPLY; 1483 m_freem(m); 1484 return (n); 1485 1486 bad: 1487 m_freem(m); 1488 if (n) 1489 m_freem(n); 1490 return (NULL); 1491 } 1492 #undef hostnamelen 1493 1494 /* 1495 * make a mbuf with DNS-encoded string. no compression support. 1496 * 1497 * XXX names with less than 2 dots (like "foo" or "foo.section") will be 1498 * treated as truncated name (two \0 at the end). this is a wild guess. 1499 * 1500 * old - return pascal string if non-zero 1501 */ 1502 static struct mbuf * 1503 ni6_nametodns(const char *name, int namelen, int old) 1504 { 1505 struct mbuf *m; 1506 char *cp, *ep; 1507 const char *p, *q; 1508 int i, len, nterm; 1509 1510 if (old) 1511 len = namelen + 1; 1512 else 1513 len = MCLBYTES; 1514 1515 /* because MAXHOSTNAMELEN is usually 256, we use cluster mbuf */ 1516 MGET(m, M_DONTWAIT, MT_DATA); 1517 if (m && len > MLEN) { 1518 MCLGET(m, M_DONTWAIT); 1519 if ((m->m_flags & M_EXT) == 0) 1520 goto fail; 1521 } 1522 if (!m) 1523 goto fail; 1524 m->m_next = NULL; 1525 1526 if (old) { 1527 m->m_len = len; 1528 *mtod(m, char *) = namelen; 1529 bcopy(name, mtod(m, char *) + 1, namelen); 1530 return m; 1531 } else { 1532 m->m_len = 0; 1533 cp = mtod(m, char *); 1534 ep = mtod(m, char *) + M_TRAILINGSPACE(m); 1535 1536 /* if not certain about my name, return empty buffer */ 1537 if (namelen == 0) 1538 return m; 1539 1540 /* 1541 * guess if it looks like shortened hostname, or FQDN. 1542 * shortened hostname needs two trailing "\0". 1543 */ 1544 i = 0; 1545 for (p = name; p < name + namelen; p++) { 1546 if (*p && *p == '.') 1547 i++; 1548 } 1549 if (i < 2) 1550 nterm = 2; 1551 else 1552 nterm = 1; 1553 1554 p = name; 1555 while (cp < ep && p < name + namelen) { 1556 i = 0; 1557 for (q = p; q < name + namelen && *q && *q != '.'; q++) 1558 i++; 1559 /* result does not fit into mbuf */ 1560 if (cp + i + 1 >= ep) 1561 goto fail; 1562 /* 1563 * DNS label length restriction, RFC1035 page 8. 1564 * "i == 0" case is included here to avoid returning 1565 * 0-length label on "foo..bar". 1566 */ 1567 if (i <= 0 || i >= 64) 1568 goto fail; 1569 *cp++ = i; 1570 bcopy(p, cp, i); 1571 cp += i; 1572 p = q; 1573 if (p < name + namelen && *p == '.') 1574 p++; 1575 } 1576 /* termination */ 1577 if (cp + nterm >= ep) 1578 goto fail; 1579 while (nterm-- > 0) 1580 *cp++ = '\0'; 1581 m->m_len = cp - mtod(m, char *); 1582 return m; 1583 } 1584 1585 panic("should not reach here"); 1586 /* NOTREACHED */ 1587 1588 fail: 1589 if (m) 1590 m_freem(m); 1591 return NULL; 1592 } 1593 1594 /* 1595 * check if two DNS-encoded string matches. takes care of truncated 1596 * form (with \0\0 at the end). no compression support. 1597 * XXX upper/lowercase match (see RFC2065) 1598 */ 1599 static int 1600 ni6_dnsmatch(const char *a, int alen, const char *b, int blen) 1601 { 1602 const char *a0, *b0; 1603 int l; 1604 1605 /* simplest case - need validation? */ 1606 if (alen == blen && bcmp(a, b, alen) == 0) 1607 return 1; 1608 1609 a0 = a; 1610 b0 = b; 1611 1612 /* termination is mandatory */ 1613 if (alen < 2 || blen < 2) 1614 return 0; 1615 if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0') 1616 return 0; 1617 alen--; 1618 blen--; 1619 1620 while (a - a0 < alen && b - b0 < blen) { 1621 if (a - a0 + 1 > alen || b - b0 + 1 > blen) 1622 return 0; 1623 1624 if ((signed char)a[0] < 0 || (signed char)b[0] < 0) 1625 return 0; 1626 /* we don't support compression yet */ 1627 if (a[0] >= 64 || b[0] >= 64) 1628 return 0; 1629 1630 /* truncated case */ 1631 if (a[0] == 0 && a - a0 == alen - 1) 1632 return 1; 1633 if (b[0] == 0 && b - b0 == blen - 1) 1634 return 1; 1635 if (a[0] == 0 || b[0] == 0) 1636 return 0; 1637 1638 if (a[0] != b[0]) 1639 return 0; 1640 l = a[0]; 1641 if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen) 1642 return 0; 1643 if (bcmp(a + 1, b + 1, l) != 0) 1644 return 0; 1645 1646 a += 1 + l; 1647 b += 1 + l; 1648 } 1649 1650 if (a - a0 == alen && b - b0 == blen) 1651 return 1; 1652 else 1653 return 0; 1654 } 1655 1656 /* 1657 * calculate the number of addresses to be returned in the node info reply. 1658 */ 1659 static int 1660 ni6_addrs(struct icmp6_nodeinfo *ni6, struct mbuf *m, struct ifnet **ifpp, 1661 struct in6_addr *subj) 1662 { 1663 INIT_VNET_NET(curvnet); 1664 INIT_VNET_INET6(curvnet); 1665 struct ifnet *ifp; 1666 struct in6_ifaddr *ifa6; 1667 struct ifaddr *ifa; 1668 int addrs = 0, addrsofif, iffound = 0; 1669 int niflags = ni6->ni_flags; 1670 1671 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) { 1672 switch (ni6->ni_code) { 1673 case ICMP6_NI_SUBJ_IPV6: 1674 if (subj == NULL) /* must be impossible... */ 1675 return (0); 1676 break; 1677 default: 1678 /* 1679 * XXX: we only support IPv6 subject address for 1680 * this Qtype. 1681 */ 1682 return (0); 1683 } 1684 } 1685 1686 IFNET_RLOCK(); 1687 for (ifp = TAILQ_FIRST(&V_ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list)) { 1688 addrsofif = 0; 1689 TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) { 1690 if (ifa->ifa_addr->sa_family != AF_INET6) 1691 continue; 1692 ifa6 = (struct in6_ifaddr *)ifa; 1693 1694 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 && 1695 IN6_ARE_ADDR_EQUAL(subj, &ifa6->ia_addr.sin6_addr)) 1696 iffound = 1; 1697 1698 /* 1699 * IPv4-mapped addresses can only be returned by a 1700 * Node Information proxy, since they represent 1701 * addresses of IPv4-only nodes, which perforce do 1702 * not implement this protocol. 1703 * [icmp-name-lookups-07, Section 5.4] 1704 * So we don't support NI_NODEADDR_FLAG_COMPAT in 1705 * this function at this moment. 1706 */ 1707 1708 /* What do we have to do about ::1? */ 1709 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { 1710 case IPV6_ADDR_SCOPE_LINKLOCAL: 1711 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) 1712 continue; 1713 break; 1714 case IPV6_ADDR_SCOPE_SITELOCAL: 1715 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) 1716 continue; 1717 break; 1718 case IPV6_ADDR_SCOPE_GLOBAL: 1719 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) 1720 continue; 1721 break; 1722 default: 1723 continue; 1724 } 1725 1726 /* 1727 * check if anycast is okay. 1728 * XXX: just experimental. not in the spec. 1729 */ 1730 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && 1731 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) 1732 continue; /* we need only unicast addresses */ 1733 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && 1734 (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) { 1735 continue; 1736 } 1737 addrsofif++; /* count the address */ 1738 } 1739 if (iffound) { 1740 *ifpp = ifp; 1741 IFNET_RUNLOCK(); 1742 return (addrsofif); 1743 } 1744 1745 addrs += addrsofif; 1746 } 1747 IFNET_RUNLOCK(); 1748 1749 return (addrs); 1750 } 1751 1752 static int 1753 ni6_store_addrs(struct icmp6_nodeinfo *ni6, struct icmp6_nodeinfo *nni6, 1754 struct ifnet *ifp0, int resid) 1755 { 1756 INIT_VNET_NET(curvnet); 1757 INIT_VNET_INET6(curvnet); 1758 struct ifnet *ifp = ifp0 ? ifp0 : TAILQ_FIRST(&V_ifnet); 1759 struct in6_ifaddr *ifa6; 1760 struct ifaddr *ifa; 1761 struct ifnet *ifp_dep = NULL; 1762 int copied = 0, allow_deprecated = 0; 1763 u_char *cp = (u_char *)(nni6 + 1); 1764 int niflags = ni6->ni_flags; 1765 u_int32_t ltime; 1766 1767 if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL)) 1768 return (0); /* needless to copy */ 1769 1770 IFNET_RLOCK(); 1771 again: 1772 1773 for (; ifp; ifp = TAILQ_NEXT(ifp, if_list)) { 1774 for (ifa = ifp->if_addrlist.tqh_first; ifa; 1775 ifa = ifa->ifa_list.tqe_next) { 1776 if (ifa->ifa_addr->sa_family != AF_INET6) 1777 continue; 1778 ifa6 = (struct in6_ifaddr *)ifa; 1779 1780 if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 && 1781 allow_deprecated == 0) { 1782 /* 1783 * prefererred address should be put before 1784 * deprecated addresses. 1785 */ 1786 1787 /* record the interface for later search */ 1788 if (ifp_dep == NULL) 1789 ifp_dep = ifp; 1790 1791 continue; 1792 } else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 && 1793 allow_deprecated != 0) 1794 continue; /* we now collect deprecated addrs */ 1795 1796 /* What do we have to do about ::1? */ 1797 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { 1798 case IPV6_ADDR_SCOPE_LINKLOCAL: 1799 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) 1800 continue; 1801 break; 1802 case IPV6_ADDR_SCOPE_SITELOCAL: 1803 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) 1804 continue; 1805 break; 1806 case IPV6_ADDR_SCOPE_GLOBAL: 1807 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) 1808 continue; 1809 break; 1810 default: 1811 continue; 1812 } 1813 1814 /* 1815 * check if anycast is okay. 1816 * XXX: just experimental. not in the spec. 1817 */ 1818 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && 1819 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) 1820 continue; 1821 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && 1822 (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) { 1823 continue; 1824 } 1825 1826 /* now we can copy the address */ 1827 if (resid < sizeof(struct in6_addr) + 1828 sizeof(u_int32_t)) { 1829 /* 1830 * We give up much more copy. 1831 * Set the truncate flag and return. 1832 */ 1833 nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE; 1834 IFNET_RUNLOCK(); 1835 return (copied); 1836 } 1837 1838 /* 1839 * Set the TTL of the address. 1840 * The TTL value should be one of the following 1841 * according to the specification: 1842 * 1843 * 1. The remaining lifetime of a DHCP lease on the 1844 * address, or 1845 * 2. The remaining Valid Lifetime of a prefix from 1846 * which the address was derived through Stateless 1847 * Autoconfiguration. 1848 * 1849 * Note that we currently do not support stateful 1850 * address configuration by DHCPv6, so the former 1851 * case can't happen. 1852 */ 1853 if (ifa6->ia6_lifetime.ia6t_expire == 0) 1854 ltime = ND6_INFINITE_LIFETIME; 1855 else { 1856 if (ifa6->ia6_lifetime.ia6t_expire > 1857 time_second) 1858 ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_second); 1859 else 1860 ltime = 0; 1861 } 1862 1863 bcopy(<ime, cp, sizeof(u_int32_t)); 1864 cp += sizeof(u_int32_t); 1865 1866 /* copy the address itself */ 1867 bcopy(&ifa6->ia_addr.sin6_addr, cp, 1868 sizeof(struct in6_addr)); 1869 in6_clearscope((struct in6_addr *)cp); /* XXX */ 1870 cp += sizeof(struct in6_addr); 1871 1872 resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t)); 1873 copied += (sizeof(struct in6_addr) + sizeof(u_int32_t)); 1874 } 1875 if (ifp0) /* we need search only on the specified IF */ 1876 break; 1877 } 1878 1879 if (allow_deprecated == 0 && ifp_dep != NULL) { 1880 ifp = ifp_dep; 1881 allow_deprecated = 1; 1882 1883 goto again; 1884 } 1885 1886 IFNET_RUNLOCK(); 1887 1888 return (copied); 1889 } 1890 1891 /* 1892 * XXX almost dup'ed code with rip6_input. 1893 */ 1894 static int 1895 icmp6_rip6_input(struct mbuf **mp, int off) 1896 { 1897 INIT_VNET_INET(curvnet); 1898 INIT_VNET_INET6(curvnet); 1899 struct mbuf *m = *mp; 1900 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1901 struct in6pcb *in6p; 1902 struct in6pcb *last = NULL; 1903 struct sockaddr_in6 fromsa; 1904 struct icmp6_hdr *icmp6; 1905 struct mbuf *opts = NULL; 1906 1907 #ifndef PULLDOWN_TEST 1908 /* this is assumed to be safe. */ 1909 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off); 1910 #else 1911 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6)); 1912 if (icmp6 == NULL) { 1913 /* m is already reclaimed */ 1914 return (IPPROTO_DONE); 1915 } 1916 #endif 1917 1918 /* 1919 * XXX: the address may have embedded scope zone ID, which should be 1920 * hidden from applications. 1921 */ 1922 bzero(&fromsa, sizeof(fromsa)); 1923 fromsa.sin6_family = AF_INET6; 1924 fromsa.sin6_len = sizeof(struct sockaddr_in6); 1925 fromsa.sin6_addr = ip6->ip6_src; 1926 if (sa6_recoverscope(&fromsa)) { 1927 m_freem(m); 1928 return (IPPROTO_DONE); 1929 } 1930 1931 INP_INFO_RLOCK(&V_ripcbinfo); 1932 LIST_FOREACH(in6p, &V_ripcb, inp_list) { 1933 if ((in6p->inp_vflag & INP_IPV6) == 0) 1934 continue; 1935 if (in6p->in6p_ip6_nxt != IPPROTO_ICMPV6) 1936 continue; 1937 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) && 1938 !IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &ip6->ip6_dst)) 1939 continue; 1940 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr) && 1941 !IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src)) 1942 continue; 1943 INP_RLOCK(in6p); 1944 if (ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type, 1945 in6p->in6p_icmp6filt)) { 1946 INP_RUNLOCK(in6p); 1947 continue; 1948 } 1949 if (last) { 1950 struct mbuf *n = NULL; 1951 1952 /* 1953 * Recent network drivers tend to allocate a single 1954 * mbuf cluster, rather than to make a couple of 1955 * mbufs without clusters. Also, since the IPv6 code 1956 * path tries to avoid m_pullup(), it is highly 1957 * probable that we still have an mbuf cluster here 1958 * even though the necessary length can be stored in an 1959 * mbuf's internal buffer. 1960 * Meanwhile, the default size of the receive socket 1961 * buffer for raw sockets is not so large. This means 1962 * the possibility of packet loss is relatively higher 1963 * than before. To avoid this scenario, we copy the 1964 * received data to a separate mbuf that does not use 1965 * a cluster, if possible. 1966 * XXX: it is better to copy the data after stripping 1967 * intermediate headers. 1968 */ 1969 if ((m->m_flags & M_EXT) && m->m_next == NULL && 1970 m->m_len <= MHLEN) { 1971 MGET(n, M_DONTWAIT, m->m_type); 1972 if (n != NULL) { 1973 if (m_dup_pkthdr(n, m, M_NOWAIT)) { 1974 bcopy(m->m_data, n->m_data, 1975 m->m_len); 1976 n->m_len = m->m_len; 1977 } else { 1978 m_free(n); 1979 n = NULL; 1980 } 1981 } 1982 } 1983 if (n != NULL || 1984 (n = m_copy(m, 0, (int)M_COPYALL)) != NULL) { 1985 if (last->in6p_flags & IN6P_CONTROLOPTS) 1986 ip6_savecontrol(last, n, &opts); 1987 /* strip intermediate headers */ 1988 m_adj(n, off); 1989 SOCKBUF_LOCK(&last->in6p_socket->so_rcv); 1990 if (sbappendaddr_locked( 1991 &last->in6p_socket->so_rcv, 1992 (struct sockaddr *)&fromsa, n, opts) 1993 == 0) { 1994 /* should notify about lost packet */ 1995 m_freem(n); 1996 if (opts) { 1997 m_freem(opts); 1998 } 1999 SOCKBUF_UNLOCK( 2000 &last->in6p_socket->so_rcv); 2001 } else 2002 sorwakeup_locked(last->in6p_socket); 2003 opts = NULL; 2004 } 2005 INP_RUNLOCK(last); 2006 } 2007 last = in6p; 2008 } 2009 INP_INFO_RUNLOCK(&V_ripcbinfo); 2010 if (last) { 2011 if (last->in6p_flags & IN6P_CONTROLOPTS) 2012 ip6_savecontrol(last, m, &opts); 2013 /* strip intermediate headers */ 2014 m_adj(m, off); 2015 2016 /* avoid using mbuf clusters if possible (see above) */ 2017 if ((m->m_flags & M_EXT) && m->m_next == NULL && 2018 m->m_len <= MHLEN) { 2019 struct mbuf *n; 2020 2021 MGET(n, M_DONTWAIT, m->m_type); 2022 if (n != NULL) { 2023 if (m_dup_pkthdr(n, m, M_NOWAIT)) { 2024 bcopy(m->m_data, n->m_data, m->m_len); 2025 n->m_len = m->m_len; 2026 2027 m_freem(m); 2028 m = n; 2029 } else { 2030 m_freem(n); 2031 n = NULL; 2032 } 2033 } 2034 } 2035 SOCKBUF_LOCK(&last->in6p_socket->so_rcv); 2036 if (sbappendaddr_locked(&last->in6p_socket->so_rcv, 2037 (struct sockaddr *)&fromsa, m, opts) == 0) { 2038 m_freem(m); 2039 if (opts) 2040 m_freem(opts); 2041 SOCKBUF_UNLOCK(&last->in6p_socket->so_rcv); 2042 } else 2043 sorwakeup_locked(last->in6p_socket); 2044 INP_RUNLOCK(last); 2045 } else { 2046 m_freem(m); 2047 V_ip6stat.ip6s_delivered--; 2048 } 2049 return IPPROTO_DONE; 2050 } 2051 2052 /* 2053 * Reflect the ip6 packet back to the source. 2054 * OFF points to the icmp6 header, counted from the top of the mbuf. 2055 */ 2056 void 2057 icmp6_reflect(struct mbuf *m, size_t off) 2058 { 2059 INIT_VNET_INET6(curvnet); 2060 struct ip6_hdr *ip6; 2061 struct icmp6_hdr *icmp6; 2062 struct in6_ifaddr *ia; 2063 int plen; 2064 int type, code; 2065 struct ifnet *outif = NULL; 2066 struct in6_addr origdst, *src = NULL; 2067 2068 /* too short to reflect */ 2069 if (off < sizeof(struct ip6_hdr)) { 2070 nd6log((LOG_DEBUG, 2071 "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n", 2072 (u_long)off, (u_long)sizeof(struct ip6_hdr), 2073 __FILE__, __LINE__)); 2074 goto bad; 2075 } 2076 2077 /* 2078 * If there are extra headers between IPv6 and ICMPv6, strip 2079 * off that header first. 2080 */ 2081 #ifdef DIAGNOSTIC 2082 if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN) 2083 panic("assumption failed in icmp6_reflect"); 2084 #endif 2085 if (off > sizeof(struct ip6_hdr)) { 2086 size_t l; 2087 struct ip6_hdr nip6; 2088 2089 l = off - sizeof(struct ip6_hdr); 2090 m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6); 2091 m_adj(m, l); 2092 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 2093 if (m->m_len < l) { 2094 if ((m = m_pullup(m, l)) == NULL) 2095 return; 2096 } 2097 bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6)); 2098 } else /* off == sizeof(struct ip6_hdr) */ { 2099 size_t l; 2100 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 2101 if (m->m_len < l) { 2102 if ((m = m_pullup(m, l)) == NULL) 2103 return; 2104 } 2105 } 2106 plen = m->m_pkthdr.len - sizeof(struct ip6_hdr); 2107 ip6 = mtod(m, struct ip6_hdr *); 2108 ip6->ip6_nxt = IPPROTO_ICMPV6; 2109 icmp6 = (struct icmp6_hdr *)(ip6 + 1); 2110 type = icmp6->icmp6_type; /* keep type for statistics */ 2111 code = icmp6->icmp6_code; /* ditto. */ 2112 2113 origdst = ip6->ip6_dst; 2114 /* 2115 * ip6_input() drops a packet if its src is multicast. 2116 * So, the src is never multicast. 2117 */ 2118 ip6->ip6_dst = ip6->ip6_src; 2119 2120 /* 2121 * If the incoming packet was addressed directly to us (i.e. unicast), 2122 * use dst as the src for the reply. 2123 * The IN6_IFF_NOTREADY case should be VERY rare, but is possible 2124 * (for example) when we encounter an error while forwarding procedure 2125 * destined to a duplicated address of ours. 2126 * Note that ip6_getdstifaddr() may fail if we are in an error handling 2127 * procedure of an outgoing packet of our own, in which case we need 2128 * to search in the ifaddr list. 2129 */ 2130 if (!IN6_IS_ADDR_MULTICAST(&origdst)) { 2131 if ((ia = ip6_getdstifaddr(m))) { 2132 if (!(ia->ia6_flags & 2133 (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) 2134 src = &ia->ia_addr.sin6_addr; 2135 } else { 2136 struct sockaddr_in6 d; 2137 2138 bzero(&d, sizeof(d)); 2139 d.sin6_family = AF_INET6; 2140 d.sin6_len = sizeof(d); 2141 d.sin6_addr = origdst; 2142 ia = (struct in6_ifaddr *) 2143 ifa_ifwithaddr((struct sockaddr *)&d); 2144 if (ia && 2145 !(ia->ia6_flags & 2146 (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) { 2147 src = &ia->ia_addr.sin6_addr; 2148 } 2149 } 2150 } 2151 2152 if (src == NULL) { 2153 int e; 2154 struct sockaddr_in6 sin6; 2155 struct route_in6 ro; 2156 2157 /* 2158 * This case matches to multicasts, our anycast, or unicasts 2159 * that we do not own. Select a source address based on the 2160 * source address of the erroneous packet. 2161 */ 2162 bzero(&sin6, sizeof(sin6)); 2163 sin6.sin6_family = AF_INET6; 2164 sin6.sin6_len = sizeof(sin6); 2165 sin6.sin6_addr = ip6->ip6_dst; /* zone ID should be embedded */ 2166 2167 bzero(&ro, sizeof(ro)); 2168 src = in6_selectsrc(&sin6, NULL, NULL, &ro, NULL, &outif, &e); 2169 if (ro.ro_rt) 2170 RTFREE(ro.ro_rt); /* XXX: we could use this */ 2171 if (src == NULL) { 2172 char ip6buf[INET6_ADDRSTRLEN]; 2173 nd6log((LOG_DEBUG, 2174 "icmp6_reflect: source can't be determined: " 2175 "dst=%s, error=%d\n", 2176 ip6_sprintf(ip6buf, &sin6.sin6_addr), e)); 2177 goto bad; 2178 } 2179 } 2180 2181 ip6->ip6_src = *src; 2182 ip6->ip6_flow = 0; 2183 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2184 ip6->ip6_vfc |= IPV6_VERSION; 2185 ip6->ip6_nxt = IPPROTO_ICMPV6; 2186 if (outif) 2187 ip6->ip6_hlim = ND_IFINFO(outif)->chlim; 2188 else if (m->m_pkthdr.rcvif) { 2189 /* XXX: This may not be the outgoing interface */ 2190 ip6->ip6_hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim; 2191 } else 2192 ip6->ip6_hlim = V_ip6_defhlim; 2193 2194 icmp6->icmp6_cksum = 0; 2195 icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2196 sizeof(struct ip6_hdr), plen); 2197 2198 /* 2199 * XXX option handling 2200 */ 2201 2202 m->m_flags &= ~(M_BCAST|M_MCAST); 2203 2204 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2205 if (outif) 2206 icmp6_ifoutstat_inc(outif, type, code); 2207 2208 return; 2209 2210 bad: 2211 m_freem(m); 2212 return; 2213 } 2214 2215 void 2216 icmp6_fasttimo(void) 2217 { 2218 2219 return; 2220 } 2221 2222 static const char * 2223 icmp6_redirect_diag(struct in6_addr *src6, struct in6_addr *dst6, 2224 struct in6_addr *tgt6) 2225 { 2226 static char buf[1024]; 2227 char ip6bufs[INET6_ADDRSTRLEN]; 2228 char ip6bufd[INET6_ADDRSTRLEN]; 2229 char ip6buft[INET6_ADDRSTRLEN]; 2230 snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)", 2231 ip6_sprintf(ip6bufs, src6), ip6_sprintf(ip6bufd, dst6), 2232 ip6_sprintf(ip6buft, tgt6)); 2233 return buf; 2234 } 2235 2236 void 2237 icmp6_redirect_input(struct mbuf *m, int off) 2238 { 2239 INIT_VNET_INET6(curvnet); 2240 struct ifnet *ifp; 2241 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 2242 struct nd_redirect *nd_rd; 2243 int icmp6len = ntohs(ip6->ip6_plen); 2244 char *lladdr = NULL; 2245 int lladdrlen = 0; 2246 u_char *redirhdr = NULL; 2247 int redirhdrlen = 0; 2248 struct rtentry *rt = NULL; 2249 int is_router; 2250 int is_onlink; 2251 struct in6_addr src6 = ip6->ip6_src; 2252 struct in6_addr redtgt6; 2253 struct in6_addr reddst6; 2254 union nd_opts ndopts; 2255 char ip6buf[INET6_ADDRSTRLEN]; 2256 2257 if (!m) 2258 return; 2259 2260 ifp = m->m_pkthdr.rcvif; 2261 2262 if (!ifp) 2263 return; 2264 2265 /* XXX if we are router, we don't update route by icmp6 redirect */ 2266 if (V_ip6_forwarding) 2267 goto freeit; 2268 if (!V_icmp6_rediraccept) 2269 goto freeit; 2270 2271 #ifndef PULLDOWN_TEST 2272 IP6_EXTHDR_CHECK(m, off, icmp6len,); 2273 nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off); 2274 #else 2275 IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len); 2276 if (nd_rd == NULL) { 2277 V_icmp6stat.icp6s_tooshort++; 2278 return; 2279 } 2280 #endif 2281 redtgt6 = nd_rd->nd_rd_target; 2282 reddst6 = nd_rd->nd_rd_dst; 2283 2284 if (in6_setscope(&redtgt6, m->m_pkthdr.rcvif, NULL) || 2285 in6_setscope(&reddst6, m->m_pkthdr.rcvif, NULL)) { 2286 goto freeit; 2287 } 2288 2289 /* validation */ 2290 if (!IN6_IS_ADDR_LINKLOCAL(&src6)) { 2291 nd6log((LOG_ERR, 2292 "ICMP6 redirect sent from %s rejected; " 2293 "must be from linklocal\n", 2294 ip6_sprintf(ip6buf, &src6))); 2295 goto bad; 2296 } 2297 if (ip6->ip6_hlim != 255) { 2298 nd6log((LOG_ERR, 2299 "ICMP6 redirect sent from %s rejected; " 2300 "hlim=%d (must be 255)\n", 2301 ip6_sprintf(ip6buf, &src6), ip6->ip6_hlim)); 2302 goto bad; 2303 } 2304 { 2305 /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */ 2306 struct sockaddr_in6 sin6; 2307 struct in6_addr *gw6; 2308 2309 bzero(&sin6, sizeof(sin6)); 2310 sin6.sin6_family = AF_INET6; 2311 sin6.sin6_len = sizeof(struct sockaddr_in6); 2312 bcopy(&reddst6, &sin6.sin6_addr, sizeof(reddst6)); 2313 rt = rtalloc1((struct sockaddr *)&sin6, 0, 0UL); 2314 if (rt) { 2315 if (rt->rt_gateway == NULL || 2316 rt->rt_gateway->sa_family != AF_INET6) { 2317 nd6log((LOG_ERR, 2318 "ICMP6 redirect rejected; no route " 2319 "with inet6 gateway found for redirect dst: %s\n", 2320 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2321 RTFREE_LOCKED(rt); 2322 goto bad; 2323 } 2324 2325 gw6 = &(((struct sockaddr_in6 *)rt->rt_gateway)->sin6_addr); 2326 if (bcmp(&src6, gw6, sizeof(struct in6_addr)) != 0) { 2327 nd6log((LOG_ERR, 2328 "ICMP6 redirect rejected; " 2329 "not equal to gw-for-src=%s (must be same): " 2330 "%s\n", 2331 ip6_sprintf(ip6buf, gw6), 2332 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2333 RTFREE_LOCKED(rt); 2334 goto bad; 2335 } 2336 } else { 2337 nd6log((LOG_ERR, 2338 "ICMP6 redirect rejected; " 2339 "no route found for redirect dst: %s\n", 2340 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2341 goto bad; 2342 } 2343 RTFREE_LOCKED(rt); 2344 rt = NULL; 2345 } 2346 if (IN6_IS_ADDR_MULTICAST(&reddst6)) { 2347 nd6log((LOG_ERR, 2348 "ICMP6 redirect rejected; " 2349 "redirect dst must be unicast: %s\n", 2350 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2351 goto bad; 2352 } 2353 2354 is_router = is_onlink = 0; 2355 if (IN6_IS_ADDR_LINKLOCAL(&redtgt6)) 2356 is_router = 1; /* router case */ 2357 if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0) 2358 is_onlink = 1; /* on-link destination case */ 2359 if (!is_router && !is_onlink) { 2360 nd6log((LOG_ERR, 2361 "ICMP6 redirect rejected; " 2362 "neither router case nor onlink case: %s\n", 2363 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2364 goto bad; 2365 } 2366 /* validation passed */ 2367 2368 icmp6len -= sizeof(*nd_rd); 2369 nd6_option_init(nd_rd + 1, icmp6len, &ndopts); 2370 if (nd6_options(&ndopts) < 0) { 2371 nd6log((LOG_INFO, "icmp6_redirect_input: " 2372 "invalid ND option, rejected: %s\n", 2373 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2374 /* nd6_options have incremented stats */ 2375 goto freeit; 2376 } 2377 2378 if (ndopts.nd_opts_tgt_lladdr) { 2379 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 2380 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 2381 } 2382 2383 if (ndopts.nd_opts_rh) { 2384 redirhdrlen = ndopts.nd_opts_rh->nd_opt_rh_len; 2385 redirhdr = (u_char *)(ndopts.nd_opts_rh + 1); /* xxx */ 2386 } 2387 2388 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 2389 nd6log((LOG_INFO, 2390 "icmp6_redirect_input: lladdrlen mismatch for %s " 2391 "(if %d, icmp6 packet %d): %s\n", 2392 ip6_sprintf(ip6buf, &redtgt6), 2393 ifp->if_addrlen, lladdrlen - 2, 2394 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2395 goto bad; 2396 } 2397 2398 /* RFC 2461 8.3 */ 2399 nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT, 2400 is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER); 2401 2402 if (!is_onlink) { /* better router case. perform rtredirect. */ 2403 /* perform rtredirect */ 2404 struct sockaddr_in6 sdst; 2405 struct sockaddr_in6 sgw; 2406 struct sockaddr_in6 ssrc; 2407 2408 bzero(&sdst, sizeof(sdst)); 2409 bzero(&sgw, sizeof(sgw)); 2410 bzero(&ssrc, sizeof(ssrc)); 2411 sdst.sin6_family = sgw.sin6_family = ssrc.sin6_family = AF_INET6; 2412 sdst.sin6_len = sgw.sin6_len = ssrc.sin6_len = 2413 sizeof(struct sockaddr_in6); 2414 bcopy(&redtgt6, &sgw.sin6_addr, sizeof(struct in6_addr)); 2415 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr)); 2416 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr)); 2417 rtredirect((struct sockaddr *)&sdst, (struct sockaddr *)&sgw, 2418 (struct sockaddr *)NULL, RTF_GATEWAY | RTF_HOST, 2419 (struct sockaddr *)&ssrc); 2420 } 2421 /* finally update cached route in each socket via pfctlinput */ 2422 { 2423 struct sockaddr_in6 sdst; 2424 2425 bzero(&sdst, sizeof(sdst)); 2426 sdst.sin6_family = AF_INET6; 2427 sdst.sin6_len = sizeof(struct sockaddr_in6); 2428 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr)); 2429 pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst); 2430 #ifdef IPSEC 2431 key_sa_routechange((struct sockaddr *)&sdst); 2432 #endif /* IPSEC */ 2433 } 2434 2435 freeit: 2436 m_freem(m); 2437 return; 2438 2439 bad: 2440 V_icmp6stat.icp6s_badredirect++; 2441 m_freem(m); 2442 } 2443 2444 void 2445 icmp6_redirect_output(struct mbuf *m0, struct rtentry *rt) 2446 { 2447 INIT_VNET_INET6(curvnet); 2448 struct ifnet *ifp; /* my outgoing interface */ 2449 struct in6_addr *ifp_ll6; 2450 struct in6_addr *router_ll6; 2451 struct ip6_hdr *sip6; /* m0 as struct ip6_hdr */ 2452 struct mbuf *m = NULL; /* newly allocated one */ 2453 struct ip6_hdr *ip6; /* m as struct ip6_hdr */ 2454 struct nd_redirect *nd_rd; 2455 size_t maxlen; 2456 u_char *p; 2457 struct ifnet *outif = NULL; 2458 struct sockaddr_in6 src_sa; 2459 2460 icmp6_errcount(&V_icmp6stat.icp6s_outerrhist, ND_REDIRECT, 0); 2461 2462 /* if we are not router, we don't send icmp6 redirect */ 2463 if (!V_ip6_forwarding) 2464 goto fail; 2465 2466 /* sanity check */ 2467 if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp)) 2468 goto fail; 2469 2470 /* 2471 * Address check: 2472 * the source address must identify a neighbor, and 2473 * the destination address must not be a multicast address 2474 * [RFC 2461, sec 8.2] 2475 */ 2476 sip6 = mtod(m0, struct ip6_hdr *); 2477 bzero(&src_sa, sizeof(src_sa)); 2478 src_sa.sin6_family = AF_INET6; 2479 src_sa.sin6_len = sizeof(src_sa); 2480 src_sa.sin6_addr = sip6->ip6_src; 2481 if (nd6_is_addr_neighbor(&src_sa, ifp) == 0) 2482 goto fail; 2483 if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst)) 2484 goto fail; /* what should we do here? */ 2485 2486 /* rate limit */ 2487 if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0)) 2488 goto fail; 2489 2490 /* 2491 * Since we are going to append up to 1280 bytes (= IPV6_MMTU), 2492 * we almost always ask for an mbuf cluster for simplicity. 2493 * (MHLEN < IPV6_MMTU is almost always true) 2494 */ 2495 #if IPV6_MMTU >= MCLBYTES 2496 # error assumption failed about IPV6_MMTU and MCLBYTES 2497 #endif 2498 MGETHDR(m, M_DONTWAIT, MT_HEADER); 2499 if (m && IPV6_MMTU >= MHLEN) 2500 MCLGET(m, M_DONTWAIT); 2501 if (!m) 2502 goto fail; 2503 m->m_pkthdr.rcvif = NULL; 2504 m->m_len = 0; 2505 maxlen = M_TRAILINGSPACE(m); 2506 maxlen = min(IPV6_MMTU, maxlen); 2507 /* just for safety */ 2508 if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) + 2509 ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) { 2510 goto fail; 2511 } 2512 2513 { 2514 /* get ip6 linklocal address for ifp(my outgoing interface). */ 2515 struct in6_ifaddr *ia; 2516 if ((ia = in6ifa_ifpforlinklocal(ifp, 2517 IN6_IFF_NOTREADY| 2518 IN6_IFF_ANYCAST)) == NULL) 2519 goto fail; 2520 ifp_ll6 = &ia->ia_addr.sin6_addr; 2521 } 2522 2523 /* get ip6 linklocal address for the router. */ 2524 if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) { 2525 struct sockaddr_in6 *sin6; 2526 sin6 = (struct sockaddr_in6 *)rt->rt_gateway; 2527 router_ll6 = &sin6->sin6_addr; 2528 if (!IN6_IS_ADDR_LINKLOCAL(router_ll6)) 2529 router_ll6 = (struct in6_addr *)NULL; 2530 } else 2531 router_ll6 = (struct in6_addr *)NULL; 2532 2533 /* ip6 */ 2534 ip6 = mtod(m, struct ip6_hdr *); 2535 ip6->ip6_flow = 0; 2536 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2537 ip6->ip6_vfc |= IPV6_VERSION; 2538 /* ip6->ip6_plen will be set later */ 2539 ip6->ip6_nxt = IPPROTO_ICMPV6; 2540 ip6->ip6_hlim = 255; 2541 /* ip6->ip6_src must be linklocal addr for my outgoing if. */ 2542 bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr)); 2543 bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr)); 2544 2545 /* ND Redirect */ 2546 nd_rd = (struct nd_redirect *)(ip6 + 1); 2547 nd_rd->nd_rd_type = ND_REDIRECT; 2548 nd_rd->nd_rd_code = 0; 2549 nd_rd->nd_rd_reserved = 0; 2550 if (rt->rt_flags & RTF_GATEWAY) { 2551 /* 2552 * nd_rd->nd_rd_target must be a link-local address in 2553 * better router cases. 2554 */ 2555 if (!router_ll6) 2556 goto fail; 2557 bcopy(router_ll6, &nd_rd->nd_rd_target, 2558 sizeof(nd_rd->nd_rd_target)); 2559 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2560 sizeof(nd_rd->nd_rd_dst)); 2561 } else { 2562 /* make sure redtgt == reddst */ 2563 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target, 2564 sizeof(nd_rd->nd_rd_target)); 2565 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2566 sizeof(nd_rd->nd_rd_dst)); 2567 } 2568 2569 p = (u_char *)(nd_rd + 1); 2570 2571 if (!router_ll6) 2572 goto nolladdropt; 2573 2574 { 2575 /* target lladdr option */ 2576 struct rtentry *rt_router = NULL; 2577 int len; 2578 struct sockaddr_dl *sdl; 2579 struct nd_opt_hdr *nd_opt; 2580 char *lladdr; 2581 2582 rt_router = nd6_lookup(router_ll6, 0, ifp); 2583 if (!rt_router) 2584 goto nolladdropt; 2585 len = sizeof(*nd_opt) + ifp->if_addrlen; 2586 len = (len + 7) & ~7; /* round by 8 */ 2587 /* safety check */ 2588 if (len + (p - (u_char *)ip6) > maxlen) 2589 goto nolladdropt; 2590 if (!(rt_router->rt_flags & RTF_GATEWAY) && 2591 (rt_router->rt_flags & RTF_LLINFO) && 2592 (rt_router->rt_gateway->sa_family == AF_LINK) && 2593 (sdl = (struct sockaddr_dl *)rt_router->rt_gateway) && 2594 sdl->sdl_alen) { 2595 nd_opt = (struct nd_opt_hdr *)p; 2596 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 2597 nd_opt->nd_opt_len = len >> 3; 2598 lladdr = (char *)(nd_opt + 1); 2599 bcopy(LLADDR(sdl), lladdr, ifp->if_addrlen); 2600 p += len; 2601 } 2602 } 2603 nolladdropt:; 2604 2605 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2606 2607 /* just to be safe */ 2608 #ifdef M_DECRYPTED /*not openbsd*/ 2609 if (m0->m_flags & M_DECRYPTED) 2610 goto noredhdropt; 2611 #endif 2612 if (p - (u_char *)ip6 > maxlen) 2613 goto noredhdropt; 2614 2615 { 2616 /* redirected header option */ 2617 int len; 2618 struct nd_opt_rd_hdr *nd_opt_rh; 2619 2620 /* 2621 * compute the maximum size for icmp6 redirect header option. 2622 * XXX room for auth header? 2623 */ 2624 len = maxlen - (p - (u_char *)ip6); 2625 len &= ~7; 2626 2627 /* This is just for simplicity. */ 2628 if (m0->m_pkthdr.len != m0->m_len) { 2629 if (m0->m_next) { 2630 m_freem(m0->m_next); 2631 m0->m_next = NULL; 2632 } 2633 m0->m_pkthdr.len = m0->m_len; 2634 } 2635 2636 /* 2637 * Redirected header option spec (RFC2461 4.6.3) talks nothing 2638 * about padding/truncate rule for the original IP packet. 2639 * From the discussion on IPv6imp in Feb 1999, 2640 * the consensus was: 2641 * - "attach as much as possible" is the goal 2642 * - pad if not aligned (original size can be guessed by 2643 * original ip6 header) 2644 * Following code adds the padding if it is simple enough, 2645 * and truncates if not. 2646 */ 2647 if (m0->m_next || m0->m_pkthdr.len != m0->m_len) 2648 panic("assumption failed in %s:%d", __FILE__, 2649 __LINE__); 2650 2651 if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) { 2652 /* not enough room, truncate */ 2653 m0->m_pkthdr.len = m0->m_len = len - 2654 sizeof(*nd_opt_rh); 2655 } else { 2656 /* enough room, pad or truncate */ 2657 size_t extra; 2658 2659 extra = m0->m_pkthdr.len % 8; 2660 if (extra) { 2661 /* pad if easy enough, truncate if not */ 2662 if (8 - extra <= M_TRAILINGSPACE(m0)) { 2663 /* pad */ 2664 m0->m_len += (8 - extra); 2665 m0->m_pkthdr.len += (8 - extra); 2666 } else { 2667 /* truncate */ 2668 m0->m_pkthdr.len -= extra; 2669 m0->m_len -= extra; 2670 } 2671 } 2672 len = m0->m_pkthdr.len + sizeof(*nd_opt_rh); 2673 m0->m_pkthdr.len = m0->m_len = len - 2674 sizeof(*nd_opt_rh); 2675 } 2676 2677 nd_opt_rh = (struct nd_opt_rd_hdr *)p; 2678 bzero(nd_opt_rh, sizeof(*nd_opt_rh)); 2679 nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER; 2680 nd_opt_rh->nd_opt_rh_len = len >> 3; 2681 p += sizeof(*nd_opt_rh); 2682 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2683 2684 /* connect m0 to m */ 2685 m_tag_delete_chain(m0, NULL); 2686 m0->m_flags &= ~M_PKTHDR; 2687 m->m_next = m0; 2688 m->m_pkthdr.len = m->m_len + m0->m_len; 2689 m0 = NULL; 2690 } 2691 noredhdropt:; 2692 if (m0) { 2693 m_freem(m0); 2694 m0 = NULL; 2695 } 2696 2697 /* XXX: clear embedded link IDs in the inner header */ 2698 in6_clearscope(&sip6->ip6_src); 2699 in6_clearscope(&sip6->ip6_dst); 2700 in6_clearscope(&nd_rd->nd_rd_target); 2701 in6_clearscope(&nd_rd->nd_rd_dst); 2702 2703 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr)); 2704 2705 nd_rd->nd_rd_cksum = 0; 2706 nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2707 sizeof(*ip6), ntohs(ip6->ip6_plen)); 2708 2709 /* send the packet to outside... */ 2710 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2711 if (outif) { 2712 icmp6_ifstat_inc(outif, ifs6_out_msg); 2713 icmp6_ifstat_inc(outif, ifs6_out_redirect); 2714 } 2715 V_icmp6stat.icp6s_outhist[ND_REDIRECT]++; 2716 2717 return; 2718 2719 fail: 2720 if (m) 2721 m_freem(m); 2722 if (m0) 2723 m_freem(m0); 2724 } 2725 2726 /* 2727 * ICMPv6 socket option processing. 2728 */ 2729 int 2730 icmp6_ctloutput(struct socket *so, struct sockopt *sopt) 2731 { 2732 int error = 0; 2733 int optlen; 2734 struct inpcb *inp = sotoinpcb(so); 2735 int level, op, optname; 2736 2737 if (sopt) { 2738 level = sopt->sopt_level; 2739 op = sopt->sopt_dir; 2740 optname = sopt->sopt_name; 2741 optlen = sopt->sopt_valsize; 2742 } else 2743 level = op = optname = optlen = 0; 2744 2745 if (level != IPPROTO_ICMPV6) { 2746 return EINVAL; 2747 } 2748 2749 switch (op) { 2750 case PRCO_SETOPT: 2751 switch (optname) { 2752 case ICMP6_FILTER: 2753 { 2754 struct icmp6_filter ic6f; 2755 2756 if (optlen != sizeof(ic6f)) { 2757 error = EMSGSIZE; 2758 break; 2759 } 2760 error = sooptcopyin(sopt, &ic6f, optlen, optlen); 2761 if (error == 0) { 2762 INP_WLOCK(inp); 2763 *inp->in6p_icmp6filt = ic6f; 2764 INP_WUNLOCK(inp); 2765 } 2766 break; 2767 } 2768 2769 default: 2770 error = ENOPROTOOPT; 2771 break; 2772 } 2773 break; 2774 2775 case PRCO_GETOPT: 2776 switch (optname) { 2777 case ICMP6_FILTER: 2778 { 2779 struct icmp6_filter ic6f; 2780 2781 INP_RLOCK(inp); 2782 ic6f = *inp->in6p_icmp6filt; 2783 INP_RUNLOCK(inp); 2784 error = sooptcopyout(sopt, &ic6f, sizeof(ic6f)); 2785 break; 2786 } 2787 2788 default: 2789 error = ENOPROTOOPT; 2790 break; 2791 } 2792 break; 2793 } 2794 2795 return (error); 2796 } 2797 2798 /* 2799 * Perform rate limit check. 2800 * Returns 0 if it is okay to send the icmp6 packet. 2801 * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate 2802 * limitation. 2803 * 2804 * XXX per-destination/type check necessary? 2805 * 2806 * dst - not used at this moment 2807 * type - not used at this moment 2808 * code - not used at this moment 2809 */ 2810 static int 2811 icmp6_ratelimit(const struct in6_addr *dst, const int type, 2812 const int code) 2813 { 2814 INIT_VNET_INET6(curvnet); 2815 int ret; 2816 2817 ret = 0; /* okay to send */ 2818 2819 /* PPS limit */ 2820 if (!ppsratecheck(&V_icmp6errppslim_last, &V_icmp6errpps_count, 2821 V_icmp6errppslim)) { 2822 /* The packet is subject to rate limit */ 2823 ret++; 2824 } 2825 2826 return ret; 2827 } 2828