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/jail.h> 73 #include <sys/kernel.h> 74 #include <sys/lock.h> 75 #include <sys/malloc.h> 76 #include <sys/mbuf.h> 77 #include <sys/proc.h> 78 #include <sys/protosw.h> 79 #include <sys/signalvar.h> 80 #include <sys/socket.h> 81 #include <sys/socketvar.h> 82 #include <sys/sx.h> 83 #include <sys/syslog.h> 84 #include <sys/systm.h> 85 #include <sys/time.h> 86 87 #include <net/if.h> 88 #include <net/if_dl.h> 89 #include <net/if_llatbl.h> 90 #include <net/if_types.h> 91 #include <net/route.h> 92 #include <net/vnet.h> 93 94 #include <netinet/in.h> 95 #include <netinet/in_pcb.h> 96 #include <netinet/in_var.h> 97 #include <netinet/ip6.h> 98 #include <netinet/icmp6.h> 99 #include <netinet/tcp_var.h> 100 101 #include <netinet6/in6_ifattach.h> 102 #include <netinet6/in6_pcb.h> 103 #include <netinet6/ip6protosw.h> 104 #include <netinet6/ip6_var.h> 105 #include <netinet6/scope6_var.h> 106 #include <netinet6/mld6_var.h> 107 #include <netinet6/nd6.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 VNET_DECLARE(struct inpcbinfo, ripcbinfo); 117 VNET_DECLARE(struct inpcbhead, ripcb); 118 VNET_DECLARE(int, icmp6errppslim); 119 VNET_DECLARE(int, icmp6_nodeinfo); 120 121 #define V_ripcbinfo VNET(ripcbinfo) 122 #define V_ripcb VNET(ripcb) 123 #define V_icmp6errppslim VNET(icmp6errppslim) 124 #define V_icmp6_nodeinfo VNET(icmp6_nodeinfo) 125 126 VNET_DEFINE(struct icmp6stat, icmp6stat); 127 static VNET_DEFINE(int, icmp6errpps_count); 128 static VNET_DEFINE(struct timeval, icmp6errppslim_last); 129 130 #define V_icmp6errpps_count VNET(icmp6errpps_count) 131 #define V_icmp6errppslim_last VNET(icmp6errppslim_last) 132 133 static void icmp6_errcount(struct icmp6errstat *, int, int); 134 static int icmp6_rip6_input(struct mbuf **, int); 135 static int icmp6_ratelimit(const struct in6_addr *, const int, const int); 136 static const char *icmp6_redirect_diag __P((struct in6_addr *, 137 struct in6_addr *, struct in6_addr *)); 138 static struct mbuf *ni6_input(struct mbuf *, int); 139 static struct mbuf *ni6_nametodns(const char *, int, int); 140 static int ni6_dnsmatch(const char *, int, const char *, int); 141 static int ni6_addrs __P((struct icmp6_nodeinfo *, struct mbuf *, 142 struct ifnet **, struct in6_addr *)); 143 static int ni6_store_addrs __P((struct icmp6_nodeinfo *, struct icmp6_nodeinfo *, 144 struct ifnet *, int)); 145 static int icmp6_notify_error(struct mbuf **, int, int, int); 146 147 148 void 149 icmp6_init(void) 150 { 151 152 V_icmp6errpps_count = 0; 153 } 154 155 static void 156 icmp6_errcount(struct icmp6errstat *stat, int type, int code) 157 { 158 switch (type) { 159 case ICMP6_DST_UNREACH: 160 switch (code) { 161 case ICMP6_DST_UNREACH_NOROUTE: 162 stat->icp6errs_dst_unreach_noroute++; 163 return; 164 case ICMP6_DST_UNREACH_ADMIN: 165 stat->icp6errs_dst_unreach_admin++; 166 return; 167 case ICMP6_DST_UNREACH_BEYONDSCOPE: 168 stat->icp6errs_dst_unreach_beyondscope++; 169 return; 170 case ICMP6_DST_UNREACH_ADDR: 171 stat->icp6errs_dst_unreach_addr++; 172 return; 173 case ICMP6_DST_UNREACH_NOPORT: 174 stat->icp6errs_dst_unreach_noport++; 175 return; 176 } 177 break; 178 case ICMP6_PACKET_TOO_BIG: 179 stat->icp6errs_packet_too_big++; 180 return; 181 case ICMP6_TIME_EXCEEDED: 182 switch (code) { 183 case ICMP6_TIME_EXCEED_TRANSIT: 184 stat->icp6errs_time_exceed_transit++; 185 return; 186 case ICMP6_TIME_EXCEED_REASSEMBLY: 187 stat->icp6errs_time_exceed_reassembly++; 188 return; 189 } 190 break; 191 case ICMP6_PARAM_PROB: 192 switch (code) { 193 case ICMP6_PARAMPROB_HEADER: 194 stat->icp6errs_paramprob_header++; 195 return; 196 case ICMP6_PARAMPROB_NEXTHEADER: 197 stat->icp6errs_paramprob_nextheader++; 198 return; 199 case ICMP6_PARAMPROB_OPTION: 200 stat->icp6errs_paramprob_option++; 201 return; 202 } 203 break; 204 case ND_REDIRECT: 205 stat->icp6errs_redirect++; 206 return; 207 } 208 stat->icp6errs_unknown++; 209 } 210 211 /* 212 * A wrapper function for icmp6_error() necessary when the erroneous packet 213 * may not contain enough scope zone information. 214 */ 215 void 216 icmp6_error2(struct mbuf *m, int type, int code, int param, 217 struct ifnet *ifp) 218 { 219 struct ip6_hdr *ip6; 220 221 if (ifp == NULL) 222 return; 223 224 #ifndef PULLDOWN_TEST 225 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), ); 226 #else 227 if (m->m_len < sizeof(struct ip6_hdr)) { 228 m = m_pullup(m, sizeof(struct ip6_hdr)); 229 if (m == NULL) 230 return; 231 } 232 #endif 233 234 ip6 = mtod(m, struct ip6_hdr *); 235 236 if (in6_setscope(&ip6->ip6_src, ifp, NULL) != 0) 237 return; 238 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0) 239 return; 240 241 icmp6_error(m, type, code, param); 242 } 243 244 /* 245 * Generate an error packet of type error in response to bad IP6 packet. 246 */ 247 void 248 icmp6_error(struct mbuf *m, int type, int code, int param) 249 { 250 struct ip6_hdr *oip6, *nip6; 251 struct icmp6_hdr *icmp6; 252 u_int preplen; 253 int off; 254 int nxt; 255 256 ICMP6STAT_INC(icp6s_error); 257 258 /* count per-type-code statistics */ 259 icmp6_errcount(&V_icmp6stat.icp6s_outerrhist, type, code); 260 261 #ifdef M_DECRYPTED /*not openbsd*/ 262 if (m->m_flags & M_DECRYPTED) { 263 ICMP6STAT_INC(icp6s_canterror); 264 goto freeit; 265 } 266 #endif 267 268 #ifndef PULLDOWN_TEST 269 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), ); 270 #else 271 if (m->m_len < sizeof(struct ip6_hdr)) { 272 m = m_pullup(m, sizeof(struct ip6_hdr)); 273 if (m == NULL) 274 return; 275 } 276 #endif 277 oip6 = mtod(m, struct ip6_hdr *); 278 279 /* 280 * If the destination address of the erroneous packet is a multicast 281 * address, or the packet was sent using link-layer multicast, 282 * we should basically suppress sending an error (RFC 2463, Section 283 * 2.4). 284 * We have two exceptions (the item e.2 in that section): 285 * - the Pakcet Too Big message can be sent for path MTU discovery. 286 * - the Parameter Problem Message that can be allowed an icmp6 error 287 * in the option type field. This check has been done in 288 * ip6_unknown_opt(), so we can just check the type and code. 289 */ 290 if ((m->m_flags & (M_BCAST|M_MCAST) || 291 IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) && 292 (type != ICMP6_PACKET_TOO_BIG && 293 (type != ICMP6_PARAM_PROB || 294 code != ICMP6_PARAMPROB_OPTION))) 295 goto freeit; 296 297 /* 298 * RFC 2463, 2.4 (e.5): source address check. 299 * XXX: the case of anycast source? 300 */ 301 if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) || 302 IN6_IS_ADDR_MULTICAST(&oip6->ip6_src)) 303 goto freeit; 304 305 /* 306 * If we are about to send ICMPv6 against ICMPv6 error/redirect, 307 * don't do it. 308 */ 309 nxt = -1; 310 off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt); 311 if (off >= 0 && nxt == IPPROTO_ICMPV6) { 312 struct icmp6_hdr *icp; 313 314 #ifndef PULLDOWN_TEST 315 IP6_EXTHDR_CHECK(m, 0, off + sizeof(struct icmp6_hdr), ); 316 icp = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 317 #else 318 IP6_EXTHDR_GET(icp, struct icmp6_hdr *, m, off, 319 sizeof(*icp)); 320 if (icp == NULL) { 321 ICMP6STAT_INC(icp6s_tooshort); 322 return; 323 } 324 #endif 325 if (icp->icmp6_type < ICMP6_ECHO_REQUEST || 326 icp->icmp6_type == ND_REDIRECT) { 327 /* 328 * ICMPv6 error 329 * Special case: for redirect (which is 330 * informational) we must not send icmp6 error. 331 */ 332 ICMP6STAT_INC(icp6s_canterror); 333 goto freeit; 334 } else { 335 /* ICMPv6 informational - send the error */ 336 } 337 } else { 338 /* non-ICMPv6 - send the error */ 339 } 340 341 oip6 = mtod(m, struct ip6_hdr *); /* adjust pointer */ 342 343 /* Finally, do rate limitation check. */ 344 if (icmp6_ratelimit(&oip6->ip6_src, type, code)) { 345 ICMP6STAT_INC(icp6s_toofreq); 346 goto freeit; 347 } 348 349 /* 350 * OK, ICMP6 can be generated. 351 */ 352 353 if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN) 354 m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len); 355 356 preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 357 M_PREPEND(m, preplen, M_DONTWAIT); 358 if (m && m->m_len < preplen) 359 m = m_pullup(m, preplen); 360 if (m == NULL) { 361 nd6log((LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__)); 362 return; 363 } 364 365 nip6 = mtod(m, struct ip6_hdr *); 366 nip6->ip6_src = oip6->ip6_src; 367 nip6->ip6_dst = oip6->ip6_dst; 368 369 in6_clearscope(&oip6->ip6_src); 370 in6_clearscope(&oip6->ip6_dst); 371 372 icmp6 = (struct icmp6_hdr *)(nip6 + 1); 373 icmp6->icmp6_type = type; 374 icmp6->icmp6_code = code; 375 icmp6->icmp6_pptr = htonl((u_int32_t)param); 376 377 /* 378 * icmp6_reflect() is designed to be in the input path. 379 * icmp6_error() can be called from both input and output path, 380 * and if we are in output path rcvif could contain bogus value. 381 * clear m->m_pkthdr.rcvif for safety, we should have enough scope 382 * information in ip header (nip6). 383 */ 384 m->m_pkthdr.rcvif = NULL; 385 386 ICMP6STAT_INC(icp6s_outhist[type]); 387 icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */ 388 389 return; 390 391 freeit: 392 /* 393 * If we can't tell whether or not we can generate ICMP6, free it. 394 */ 395 m_freem(m); 396 } 397 398 /* 399 * Process a received ICMP6 message. 400 */ 401 int 402 icmp6_input(struct mbuf **mp, int *offp, int proto) 403 { 404 struct mbuf *m = *mp, *n; 405 struct ifnet *ifp; 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 ifp = m->m_pkthdr.rcvif; 414 415 #ifndef PULLDOWN_TEST 416 IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_hdr), IPPROTO_DONE); 417 /* m might change if M_LOOP. So, call mtod after this */ 418 #endif 419 420 /* 421 * Locate icmp6 structure in mbuf, and check 422 * that not corrupted and of at least minimum length 423 */ 424 425 ip6 = mtod(m, struct ip6_hdr *); 426 if (icmp6len < sizeof(struct icmp6_hdr)) { 427 ICMP6STAT_INC(icp6s_tooshort); 428 goto freeit; 429 } 430 431 /* 432 * Check multicast group membership. 433 * Note: SSM filters are not applied for ICMPv6 traffic. 434 */ 435 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 436 struct in6_multi *inm; 437 438 inm = in6m_lookup(ifp, &ip6->ip6_dst); 439 if (inm == NULL) { 440 IP6STAT_INC(ip6s_notmember); 441 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 442 goto freeit; 443 } 444 } 445 446 /* 447 * calculate the checksum 448 */ 449 #ifndef PULLDOWN_TEST 450 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off); 451 #else 452 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6)); 453 if (icmp6 == NULL) { 454 ICMP6STAT_INC(icp6s_tooshort); 455 return IPPROTO_DONE; 456 } 457 #endif 458 code = icmp6->icmp6_code; 459 460 if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) { 461 nd6log((LOG_ERR, 462 "ICMP6 checksum error(%d|%x) %s\n", 463 icmp6->icmp6_type, sum, 464 ip6_sprintf(ip6bufs, &ip6->ip6_src))); 465 ICMP6STAT_INC(icp6s_checksum); 466 goto freeit; 467 } 468 469 if (faithprefix_p != NULL && (*faithprefix_p)(&ip6->ip6_dst)) { 470 /* 471 * Deliver very specific ICMP6 type only. 472 * This is important to deliver TOOBIG. Otherwise PMTUD 473 * will not work. 474 */ 475 switch (icmp6->icmp6_type) { 476 case ICMP6_DST_UNREACH: 477 case ICMP6_PACKET_TOO_BIG: 478 case ICMP6_TIME_EXCEEDED: 479 break; 480 default: 481 goto freeit; 482 } 483 } 484 485 ICMP6STAT_INC(icp6s_inhist[icmp6->icmp6_type]); 486 icmp6_ifstat_inc(ifp, ifs6_in_msg); 487 if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK) 488 icmp6_ifstat_inc(ifp, ifs6_in_error); 489 490 switch (icmp6->icmp6_type) { 491 case ICMP6_DST_UNREACH: 492 icmp6_ifstat_inc(ifp, ifs6_in_dstunreach); 493 switch (code) { 494 case ICMP6_DST_UNREACH_NOROUTE: 495 code = PRC_UNREACH_NET; 496 break; 497 case ICMP6_DST_UNREACH_ADMIN: 498 icmp6_ifstat_inc(ifp, ifs6_in_adminprohib); 499 code = PRC_UNREACH_PROTOCOL; /* is this a good code? */ 500 break; 501 case ICMP6_DST_UNREACH_ADDR: 502 code = PRC_HOSTDEAD; 503 break; 504 case ICMP6_DST_UNREACH_BEYONDSCOPE: 505 /* I mean "source address was incorrect." */ 506 code = PRC_PARAMPROB; 507 break; 508 case ICMP6_DST_UNREACH_NOPORT: 509 code = PRC_UNREACH_PORT; 510 break; 511 default: 512 goto badcode; 513 } 514 goto deliver; 515 break; 516 517 case ICMP6_PACKET_TOO_BIG: 518 icmp6_ifstat_inc(ifp, ifs6_in_pkttoobig); 519 520 /* validation is made in icmp6_mtudisc_update */ 521 522 code = PRC_MSGSIZE; 523 524 /* 525 * Updating the path MTU will be done after examining 526 * intermediate extension headers. 527 */ 528 goto deliver; 529 break; 530 531 case ICMP6_TIME_EXCEEDED: 532 icmp6_ifstat_inc(ifp, ifs6_in_timeexceed); 533 switch (code) { 534 case ICMP6_TIME_EXCEED_TRANSIT: 535 code = PRC_TIMXCEED_INTRANS; 536 break; 537 case ICMP6_TIME_EXCEED_REASSEMBLY: 538 code = PRC_TIMXCEED_REASS; 539 break; 540 default: 541 goto badcode; 542 } 543 goto deliver; 544 break; 545 546 case ICMP6_PARAM_PROB: 547 icmp6_ifstat_inc(ifp, ifs6_in_paramprob); 548 switch (code) { 549 case ICMP6_PARAMPROB_NEXTHEADER: 550 code = PRC_UNREACH_PROTOCOL; 551 break; 552 case ICMP6_PARAMPROB_HEADER: 553 case ICMP6_PARAMPROB_OPTION: 554 code = PRC_PARAMPROB; 555 break; 556 default: 557 goto badcode; 558 } 559 goto deliver; 560 break; 561 562 case ICMP6_ECHO_REQUEST: 563 icmp6_ifstat_inc(ifp, ifs6_in_echo); 564 if (code != 0) 565 goto badcode; 566 if ((n = m_copy(m, 0, M_COPYALL)) == NULL) { 567 /* Give up remote */ 568 break; 569 } 570 if ((n->m_flags & M_EXT) != 0 571 || n->m_len < off + sizeof(struct icmp6_hdr)) { 572 struct mbuf *n0 = n; 573 const int maxlen = sizeof(*nip6) + sizeof(*nicmp6); 574 int n0len; 575 576 MGETHDR(n, M_DONTWAIT, n0->m_type); 577 n0len = n0->m_pkthdr.len; /* save for use below */ 578 if (n) 579 M_MOVE_PKTHDR(n, n0); 580 if (n && maxlen >= MHLEN) { 581 MCLGET(n, M_DONTWAIT); 582 if ((n->m_flags & M_EXT) == 0) { 583 m_free(n); 584 n = NULL; 585 } 586 } 587 if (n == NULL) { 588 /* Give up remote */ 589 m_freem(n0); 590 break; 591 } 592 /* 593 * Copy IPv6 and ICMPv6 only. 594 */ 595 nip6 = mtod(n, struct ip6_hdr *); 596 bcopy(ip6, nip6, sizeof(struct ip6_hdr)); 597 nicmp6 = (struct icmp6_hdr *)(nip6 + 1); 598 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr)); 599 noff = sizeof(struct ip6_hdr); 600 /* new mbuf contains only ipv6+icmpv6 headers */ 601 n->m_len = noff + sizeof(struct icmp6_hdr); 602 /* 603 * Adjust mbuf. ip6_plen will be adjusted in 604 * ip6_output(). 605 */ 606 m_adj(n0, off + sizeof(struct icmp6_hdr)); 607 /* recalculate complete packet size */ 608 n->m_pkthdr.len = n0len + (noff - off); 609 n->m_next = n0; 610 } else { 611 nip6 = mtod(n, struct ip6_hdr *); 612 IP6_EXTHDR_GET(nicmp6, struct icmp6_hdr *, n, off, 613 sizeof(*nicmp6)); 614 noff = off; 615 } 616 nicmp6->icmp6_type = ICMP6_ECHO_REPLY; 617 nicmp6->icmp6_code = 0; 618 if (n) { 619 ICMP6STAT_INC(icp6s_reflect); 620 ICMP6STAT_INC(icp6s_outhist[ICMP6_ECHO_REPLY]); 621 icmp6_reflect(n, noff); 622 } 623 break; 624 625 case ICMP6_ECHO_REPLY: 626 icmp6_ifstat_inc(ifp, ifs6_in_echoreply); 627 if (code != 0) 628 goto badcode; 629 break; 630 631 case MLD_LISTENER_QUERY: 632 case MLD_LISTENER_REPORT: 633 case MLD_LISTENER_DONE: 634 case MLDV2_LISTENER_REPORT: 635 /* 636 * Drop MLD traffic which is not link-local, has a hop limit 637 * of greater than 1 hop, or which does not have the 638 * IPv6 HBH Router Alert option. 639 * As IPv6 HBH options are stripped in ip6_input() we must 640 * check an mbuf header flag. 641 * XXX Should we also sanity check that these messages 642 * were directed to a link-local multicast prefix? 643 */ 644 if ((ip6->ip6_hlim != 1) || (m->m_flags & M_RTALERT_MLD) == 0) 645 goto freeit; 646 if (mld_input(m, off, icmp6len) != 0) 647 return (IPPROTO_DONE); 648 /* m stays. */ 649 break; 650 651 case ICMP6_WRUREQUEST: /* ICMP6_FQDN_QUERY */ 652 { 653 enum { WRU, FQDN } mode; 654 655 if (!V_icmp6_nodeinfo) 656 break; 657 658 if (icmp6len == sizeof(struct icmp6_hdr) + 4) 659 mode = WRU; 660 else if (icmp6len >= sizeof(struct icmp6_nodeinfo)) 661 mode = FQDN; 662 else 663 goto badlen; 664 665 if (mode == FQDN) { 666 #ifndef PULLDOWN_TEST 667 IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_nodeinfo), 668 IPPROTO_DONE); 669 #endif 670 n = m_copy(m, 0, M_COPYALL); 671 if (n) 672 n = ni6_input(n, off); 673 /* XXX meaningless if n == NULL */ 674 noff = sizeof(struct ip6_hdr); 675 } else { 676 struct prison *pr; 677 u_char *p; 678 int maxlen, maxhlen, hlen; 679 680 /* 681 * XXX: this combination of flags is pointless, 682 * but should we keep this for compatibility? 683 */ 684 if ((V_icmp6_nodeinfo & 5) != 5) 685 break; 686 687 if (code != 0) 688 goto badcode; 689 maxlen = sizeof(*nip6) + sizeof(*nicmp6) + 4; 690 if (maxlen >= MCLBYTES) { 691 /* Give up remote */ 692 break; 693 } 694 MGETHDR(n, M_DONTWAIT, m->m_type); 695 if (n && maxlen > MHLEN) { 696 MCLGET(n, M_DONTWAIT); 697 if ((n->m_flags & M_EXT) == 0) { 698 m_free(n); 699 n = NULL; 700 } 701 } 702 if (n && !m_dup_pkthdr(n, m, M_DONTWAIT)) { 703 /* 704 * Previous code did a blind M_COPY_PKTHDR 705 * and said "just for rcvif". If true, then 706 * we could tolerate the dup failing (due to 707 * the deep copy of the tag chain). For now 708 * be conservative and just fail. 709 */ 710 m_free(n); 711 n = NULL; 712 } 713 if (n == NULL) { 714 /* Give up remote */ 715 break; 716 } 717 n->m_pkthdr.rcvif = NULL; 718 n->m_len = 0; 719 maxhlen = M_TRAILINGSPACE(n) - maxlen; 720 pr = curthread->td_ucred->cr_prison; 721 mtx_lock(&pr->pr_mtx); 722 hlen = strlen(pr->pr_hostname); 723 if (maxhlen > hlen) 724 maxhlen = hlen; 725 /* 726 * Copy IPv6 and ICMPv6 only. 727 */ 728 nip6 = mtod(n, struct ip6_hdr *); 729 bcopy(ip6, nip6, sizeof(struct ip6_hdr)); 730 nicmp6 = (struct icmp6_hdr *)(nip6 + 1); 731 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr)); 732 p = (u_char *)(nicmp6 + 1); 733 bzero(p, 4); 734 /* meaningless TTL */ 735 bcopy(pr->pr_hostname, p + 4, maxhlen); 736 mtx_unlock(&pr->pr_mtx); 737 noff = sizeof(struct ip6_hdr); 738 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + 739 sizeof(struct icmp6_hdr) + 4 + maxhlen; 740 nicmp6->icmp6_type = ICMP6_WRUREPLY; 741 nicmp6->icmp6_code = 0; 742 } 743 if (n) { 744 ICMP6STAT_INC(icp6s_reflect); 745 ICMP6STAT_INC(icp6s_outhist[ICMP6_WRUREPLY]); 746 icmp6_reflect(n, noff); 747 } 748 break; 749 } 750 751 case ICMP6_WRUREPLY: 752 if (code != 0) 753 goto badcode; 754 break; 755 756 case ND_ROUTER_SOLICIT: 757 icmp6_ifstat_inc(ifp, ifs6_in_routersolicit); 758 if (code != 0) 759 goto badcode; 760 if (icmp6len < sizeof(struct nd_router_solicit)) 761 goto badlen; 762 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 763 /* give up local */ 764 nd6_rs_input(m, off, icmp6len); 765 m = NULL; 766 goto freeit; 767 } 768 nd6_rs_input(n, off, icmp6len); 769 /* m stays. */ 770 break; 771 772 case ND_ROUTER_ADVERT: 773 icmp6_ifstat_inc(ifp, ifs6_in_routeradvert); 774 if (code != 0) 775 goto badcode; 776 if (icmp6len < sizeof(struct nd_router_advert)) 777 goto badlen; 778 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 779 /* give up local */ 780 nd6_ra_input(m, off, icmp6len); 781 m = NULL; 782 goto freeit; 783 } 784 nd6_ra_input(n, off, icmp6len); 785 /* m stays. */ 786 break; 787 788 case ND_NEIGHBOR_SOLICIT: 789 icmp6_ifstat_inc(ifp, ifs6_in_neighborsolicit); 790 if (code != 0) 791 goto badcode; 792 if (icmp6len < sizeof(struct nd_neighbor_solicit)) 793 goto badlen; 794 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 795 /* give up local */ 796 nd6_ns_input(m, off, icmp6len); 797 m = NULL; 798 goto freeit; 799 } 800 nd6_ns_input(n, off, icmp6len); 801 /* m stays. */ 802 break; 803 804 case ND_NEIGHBOR_ADVERT: 805 icmp6_ifstat_inc(ifp, ifs6_in_neighboradvert); 806 if (code != 0) 807 goto badcode; 808 if (icmp6len < sizeof(struct nd_neighbor_advert)) 809 goto badlen; 810 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 811 /* give up local */ 812 nd6_na_input(m, off, icmp6len); 813 m = NULL; 814 goto freeit; 815 } 816 nd6_na_input(n, off, icmp6len); 817 /* m stays. */ 818 break; 819 820 case ND_REDIRECT: 821 icmp6_ifstat_inc(ifp, ifs6_in_redirect); 822 if (code != 0) 823 goto badcode; 824 if (icmp6len < sizeof(struct nd_redirect)) 825 goto badlen; 826 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 827 /* give up local */ 828 icmp6_redirect_input(m, off); 829 m = NULL; 830 goto freeit; 831 } 832 icmp6_redirect_input(n, off); 833 /* m stays. */ 834 break; 835 836 case ICMP6_ROUTER_RENUMBERING: 837 if (code != ICMP6_ROUTER_RENUMBERING_COMMAND && 838 code != ICMP6_ROUTER_RENUMBERING_RESULT) 839 goto badcode; 840 if (icmp6len < sizeof(struct icmp6_router_renum)) 841 goto badlen; 842 break; 843 844 default: 845 nd6log((LOG_DEBUG, 846 "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n", 847 icmp6->icmp6_type, ip6_sprintf(ip6bufs, &ip6->ip6_src), 848 ip6_sprintf(ip6bufd, &ip6->ip6_dst), 849 ifp ? ifp->if_index : 0)); 850 if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) { 851 /* ICMPv6 error: MUST deliver it by spec... */ 852 code = PRC_NCMDS; 853 /* deliver */ 854 } else { 855 /* ICMPv6 informational: MUST not deliver */ 856 break; 857 } 858 deliver: 859 if (icmp6_notify_error(&m, off, icmp6len, code)) { 860 /* In this case, m should've been freed. */ 861 return (IPPROTO_DONE); 862 } 863 break; 864 865 badcode: 866 ICMP6STAT_INC(icp6s_badcode); 867 break; 868 869 badlen: 870 ICMP6STAT_INC(icp6s_badlen); 871 break; 872 } 873 874 /* deliver the packet to appropriate sockets */ 875 icmp6_rip6_input(&m, *offp); 876 877 return IPPROTO_DONE; 878 879 freeit: 880 m_freem(m); 881 return IPPROTO_DONE; 882 } 883 884 static int 885 icmp6_notify_error(struct mbuf **mp, int off, int icmp6len, int code) 886 { 887 struct mbuf *m = *mp; 888 struct icmp6_hdr *icmp6; 889 struct ip6_hdr *eip6; 890 u_int32_t notifymtu; 891 struct sockaddr_in6 icmp6src, icmp6dst; 892 893 if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) { 894 ICMP6STAT_INC(icp6s_tooshort); 895 goto freeit; 896 } 897 #ifndef PULLDOWN_TEST 898 IP6_EXTHDR_CHECK(m, off, 899 sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr), -1); 900 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 901 #else 902 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, 903 sizeof(*icmp6) + sizeof(struct ip6_hdr)); 904 if (icmp6 == NULL) { 905 ICMP6STAT_INC(icp6s_tooshort); 906 return (-1); 907 } 908 #endif 909 eip6 = (struct ip6_hdr *)(icmp6 + 1); 910 911 /* Detect the upper level protocol */ 912 { 913 void (*ctlfunc)(int, struct sockaddr *, void *); 914 u_int8_t nxt = eip6->ip6_nxt; 915 int eoff = off + sizeof(struct icmp6_hdr) + 916 sizeof(struct ip6_hdr); 917 struct ip6ctlparam ip6cp; 918 struct in6_addr *finaldst = NULL; 919 int icmp6type = icmp6->icmp6_type; 920 struct ip6_frag *fh; 921 struct ip6_rthdr *rth; 922 struct ip6_rthdr0 *rth0; 923 int rthlen; 924 925 while (1) { /* XXX: should avoid infinite loop explicitly? */ 926 struct ip6_ext *eh; 927 928 switch (nxt) { 929 case IPPROTO_HOPOPTS: 930 case IPPROTO_DSTOPTS: 931 case IPPROTO_AH: 932 #ifndef PULLDOWN_TEST 933 IP6_EXTHDR_CHECK(m, 0, 934 eoff + sizeof(struct ip6_ext), -1); 935 eh = (struct ip6_ext *)(mtod(m, caddr_t) + eoff); 936 #else 937 IP6_EXTHDR_GET(eh, struct ip6_ext *, m, 938 eoff, sizeof(*eh)); 939 if (eh == NULL) { 940 ICMP6STAT_INC(icp6s_tooshort); 941 return (-1); 942 } 943 #endif 944 945 if (nxt == IPPROTO_AH) 946 eoff += (eh->ip6e_len + 2) << 2; 947 else 948 eoff += (eh->ip6e_len + 1) << 3; 949 nxt = eh->ip6e_nxt; 950 break; 951 case IPPROTO_ROUTING: 952 /* 953 * When the erroneous packet contains a 954 * routing header, we should examine the 955 * header to determine the final destination. 956 * Otherwise, we can't properly update 957 * information that depends on the final 958 * destination (e.g. path MTU). 959 */ 960 #ifndef PULLDOWN_TEST 961 IP6_EXTHDR_CHECK(m, 0, eoff + sizeof(*rth), -1); 962 rth = (struct ip6_rthdr *) 963 (mtod(m, caddr_t) + eoff); 964 #else 965 IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m, 966 eoff, sizeof(*rth)); 967 if (rth == NULL) { 968 ICMP6STAT_INC(icp6s_tooshort); 969 return (-1); 970 } 971 #endif 972 rthlen = (rth->ip6r_len + 1) << 3; 973 /* 974 * XXX: currently there is no 975 * officially defined type other 976 * than type-0. 977 * Note that if the segment left field 978 * is 0, all intermediate hops must 979 * have been passed. 980 */ 981 if (rth->ip6r_segleft && 982 rth->ip6r_type == IPV6_RTHDR_TYPE_0) { 983 int hops; 984 985 #ifndef PULLDOWN_TEST 986 IP6_EXTHDR_CHECK(m, 0, eoff + rthlen, -1); 987 rth0 = (struct ip6_rthdr0 *) 988 (mtod(m, caddr_t) + eoff); 989 #else 990 IP6_EXTHDR_GET(rth0, 991 struct ip6_rthdr0 *, m, 992 eoff, rthlen); 993 if (rth0 == NULL) { 994 ICMP6STAT_INC(icp6s_tooshort); 995 return (-1); 996 } 997 #endif 998 /* just ignore a bogus header */ 999 if ((rth0->ip6r0_len % 2) == 0 && 1000 (hops = rth0->ip6r0_len/2)) 1001 finaldst = (struct in6_addr *)(rth0 + 1) + (hops - 1); 1002 } 1003 eoff += rthlen; 1004 nxt = rth->ip6r_nxt; 1005 break; 1006 case IPPROTO_FRAGMENT: 1007 #ifndef PULLDOWN_TEST 1008 IP6_EXTHDR_CHECK(m, 0, eoff + 1009 sizeof(struct ip6_frag), -1); 1010 fh = (struct ip6_frag *)(mtod(m, caddr_t) + 1011 eoff); 1012 #else 1013 IP6_EXTHDR_GET(fh, struct ip6_frag *, m, 1014 eoff, sizeof(*fh)); 1015 if (fh == NULL) { 1016 ICMP6STAT_INC(icp6s_tooshort); 1017 return (-1); 1018 } 1019 #endif 1020 /* 1021 * Data after a fragment header is meaningless 1022 * unless it is the first fragment, but 1023 * we'll go to the notify label for path MTU 1024 * discovery. 1025 */ 1026 if (fh->ip6f_offlg & IP6F_OFF_MASK) 1027 goto notify; 1028 1029 eoff += sizeof(struct ip6_frag); 1030 nxt = fh->ip6f_nxt; 1031 break; 1032 default: 1033 /* 1034 * This case includes ESP and the No Next 1035 * Header. In such cases going to the notify 1036 * label does not have any meaning 1037 * (i.e. ctlfunc will be NULL), but we go 1038 * anyway since we might have to update 1039 * path MTU information. 1040 */ 1041 goto notify; 1042 } 1043 } 1044 notify: 1045 #ifndef PULLDOWN_TEST 1046 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 1047 #else 1048 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, 1049 sizeof(*icmp6) + sizeof(struct ip6_hdr)); 1050 if (icmp6 == NULL) { 1051 ICMP6STAT_INC(icp6s_tooshort); 1052 return (-1); 1053 } 1054 #endif 1055 1056 /* 1057 * retrieve parameters from the inner IPv6 header, and convert 1058 * them into sockaddr structures. 1059 * XXX: there is no guarantee that the source or destination 1060 * addresses of the inner packet are in the same scope as 1061 * the addresses of the icmp packet. But there is no other 1062 * way to determine the zone. 1063 */ 1064 eip6 = (struct ip6_hdr *)(icmp6 + 1); 1065 1066 bzero(&icmp6dst, sizeof(icmp6dst)); 1067 icmp6dst.sin6_len = sizeof(struct sockaddr_in6); 1068 icmp6dst.sin6_family = AF_INET6; 1069 if (finaldst == NULL) 1070 icmp6dst.sin6_addr = eip6->ip6_dst; 1071 else 1072 icmp6dst.sin6_addr = *finaldst; 1073 if (in6_setscope(&icmp6dst.sin6_addr, m->m_pkthdr.rcvif, NULL)) 1074 goto freeit; 1075 bzero(&icmp6src, sizeof(icmp6src)); 1076 icmp6src.sin6_len = sizeof(struct sockaddr_in6); 1077 icmp6src.sin6_family = AF_INET6; 1078 icmp6src.sin6_addr = eip6->ip6_src; 1079 if (in6_setscope(&icmp6src.sin6_addr, m->m_pkthdr.rcvif, NULL)) 1080 goto freeit; 1081 icmp6src.sin6_flowinfo = 1082 (eip6->ip6_flow & IPV6_FLOWLABEL_MASK); 1083 1084 if (finaldst == NULL) 1085 finaldst = &eip6->ip6_dst; 1086 ip6cp.ip6c_m = m; 1087 ip6cp.ip6c_icmp6 = icmp6; 1088 ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1); 1089 ip6cp.ip6c_off = eoff; 1090 ip6cp.ip6c_finaldst = finaldst; 1091 ip6cp.ip6c_src = &icmp6src; 1092 ip6cp.ip6c_nxt = nxt; 1093 1094 if (icmp6type == ICMP6_PACKET_TOO_BIG) { 1095 notifymtu = ntohl(icmp6->icmp6_mtu); 1096 ip6cp.ip6c_cmdarg = (void *)¬ifymtu; 1097 icmp6_mtudisc_update(&ip6cp, 1); /*XXX*/ 1098 } 1099 1100 ctlfunc = (void (*)(int, struct sockaddr *, void *)) 1101 (inet6sw[ip6_protox[nxt]].pr_ctlinput); 1102 if (ctlfunc) { 1103 (void) (*ctlfunc)(code, (struct sockaddr *)&icmp6dst, 1104 &ip6cp); 1105 } 1106 } 1107 *mp = m; 1108 return (0); 1109 1110 freeit: 1111 m_freem(m); 1112 return (-1); 1113 } 1114 1115 void 1116 icmp6_mtudisc_update(struct ip6ctlparam *ip6cp, int validated) 1117 { 1118 struct in6_addr *dst = ip6cp->ip6c_finaldst; 1119 struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6; 1120 struct mbuf *m = ip6cp->ip6c_m; /* will be necessary for scope issue */ 1121 u_int mtu = ntohl(icmp6->icmp6_mtu); 1122 struct in_conninfo inc; 1123 1124 #if 0 1125 /* 1126 * RFC2460 section 5, last paragraph. 1127 * even though minimum link MTU for IPv6 is IPV6_MMTU, 1128 * we may see ICMPv6 too big with mtu < IPV6_MMTU 1129 * due to packet translator in the middle. 1130 * see ip6_output() and ip6_getpmtu() "alwaysfrag" case for 1131 * special handling. 1132 */ 1133 if (mtu < IPV6_MMTU) 1134 return; 1135 #endif 1136 1137 /* 1138 * we reject ICMPv6 too big with abnormally small value. 1139 * XXX what is the good definition of "abnormally small"? 1140 */ 1141 if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8) 1142 return; 1143 1144 if (!validated) 1145 return; 1146 1147 /* 1148 * In case the suggested mtu is less than IPV6_MMTU, we 1149 * only need to remember that it was for above mentioned 1150 * "alwaysfrag" case. 1151 * Try to be as close to the spec as possible. 1152 */ 1153 if (mtu < IPV6_MMTU) 1154 mtu = IPV6_MMTU - 8; 1155 1156 bzero(&inc, sizeof(inc)); 1157 inc.inc_flags |= INC_ISIPV6; 1158 inc.inc6_faddr = *dst; 1159 if (in6_setscope(&inc.inc6_faddr, m->m_pkthdr.rcvif, NULL)) 1160 return; 1161 1162 if (mtu < tcp_maxmtu6(&inc, NULL)) { 1163 tcp_hc_updatemtu(&inc, mtu); 1164 ICMP6STAT_INC(icp6s_pmtuchg); 1165 } 1166 } 1167 1168 /* 1169 * Process a Node Information Query packet, based on 1170 * draft-ietf-ipngwg-icmp-name-lookups-07. 1171 * 1172 * Spec incompatibilities: 1173 * - IPv6 Subject address handling 1174 * - IPv4 Subject address handling support missing 1175 * - Proxy reply (answer even if it's not for me) 1176 * - joins NI group address at in6_ifattach() time only, does not cope 1177 * with hostname changes by sethostname(3) 1178 */ 1179 static struct mbuf * 1180 ni6_input(struct mbuf *m, int off) 1181 { 1182 struct icmp6_nodeinfo *ni6, *nni6; 1183 struct mbuf *n = NULL; 1184 struct prison *pr; 1185 u_int16_t qtype; 1186 int subjlen; 1187 int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); 1188 struct ni_reply_fqdn *fqdn; 1189 int addrs; /* for NI_QTYPE_NODEADDR */ 1190 struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */ 1191 struct in6_addr in6_subj; /* subject address */ 1192 struct ip6_hdr *ip6; 1193 int oldfqdn = 0; /* if 1, return pascal string (03 draft) */ 1194 char *subj = NULL; 1195 struct in6_ifaddr *ia6 = NULL; 1196 1197 ip6 = mtod(m, struct ip6_hdr *); 1198 #ifndef PULLDOWN_TEST 1199 ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off); 1200 #else 1201 IP6_EXTHDR_GET(ni6, struct icmp6_nodeinfo *, m, off, sizeof(*ni6)); 1202 if (ni6 == NULL) { 1203 /* m is already reclaimed */ 1204 return (NULL); 1205 } 1206 #endif 1207 1208 /* 1209 * Validate IPv6 source address. 1210 * The default configuration MUST be to refuse answering queries from 1211 * global-scope addresses according to RFC4602. 1212 * Notes: 1213 * - it's not very clear what "refuse" means; this implementation 1214 * simply drops it. 1215 * - it's not very easy to identify global-scope (unicast) addresses 1216 * since there are many prefixes for them. It should be safer 1217 * and in practice sufficient to check "all" but loopback and 1218 * link-local (note that site-local unicast was deprecated and 1219 * ULA is defined as global scope-wise) 1220 */ 1221 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_GLOBALOK) == 0 && 1222 !IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) && 1223 !IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) 1224 goto bad; 1225 1226 /* 1227 * Validate IPv6 destination address. 1228 * 1229 * The Responder must discard the Query without further processing 1230 * unless it is one of the Responder's unicast or anycast addresses, or 1231 * a link-local scope multicast address which the Responder has joined. 1232 * [RFC4602, Section 5.] 1233 */ 1234 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 1235 if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst)) 1236 goto bad; 1237 /* else it's a link-local multicast, fine */ 1238 } else { /* unicast or anycast */ 1239 if ((ia6 = ip6_getdstifaddr(m)) == NULL) 1240 goto bad; /* XXX impossible */ 1241 1242 if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) && 1243 !(V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK)) { 1244 ifa_free(&ia6->ia_ifa); 1245 nd6log((LOG_DEBUG, "ni6_input: ignore node info to " 1246 "a temporary address in %s:%d", 1247 __FILE__, __LINE__)); 1248 goto bad; 1249 } 1250 ifa_free(&ia6->ia_ifa); 1251 } 1252 1253 /* validate query Subject field. */ 1254 qtype = ntohs(ni6->ni_qtype); 1255 subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo); 1256 switch (qtype) { 1257 case NI_QTYPE_NOOP: 1258 case NI_QTYPE_SUPTYPES: 1259 /* 07 draft */ 1260 if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0) 1261 break; 1262 /* FALLTHROUGH */ 1263 case NI_QTYPE_FQDN: 1264 case NI_QTYPE_NODEADDR: 1265 case NI_QTYPE_IPV4ADDR: 1266 switch (ni6->ni_code) { 1267 case ICMP6_NI_SUBJ_IPV6: 1268 #if ICMP6_NI_SUBJ_IPV6 != 0 1269 case 0: 1270 #endif 1271 /* 1272 * backward compatibility - try to accept 03 draft 1273 * format, where no Subject is present. 1274 */ 1275 if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 && 1276 subjlen == 0) { 1277 oldfqdn++; 1278 break; 1279 } 1280 #if ICMP6_NI_SUBJ_IPV6 != 0 1281 if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6) 1282 goto bad; 1283 #endif 1284 1285 if (subjlen != sizeof(struct in6_addr)) 1286 goto bad; 1287 1288 /* 1289 * Validate Subject address. 1290 * 1291 * Not sure what exactly "address belongs to the node" 1292 * means in the spec, is it just unicast, or what? 1293 * 1294 * At this moment we consider Subject address as 1295 * "belong to the node" if the Subject address equals 1296 * to the IPv6 destination address; validation for 1297 * IPv6 destination address should have done enough 1298 * check for us. 1299 * 1300 * We do not do proxy at this moment. 1301 */ 1302 /* m_pulldown instead of copy? */ 1303 m_copydata(m, off + sizeof(struct icmp6_nodeinfo), 1304 subjlen, (caddr_t)&in6_subj); 1305 if (in6_setscope(&in6_subj, m->m_pkthdr.rcvif, NULL)) 1306 goto bad; 1307 1308 subj = (char *)&in6_subj; 1309 if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &in6_subj)) 1310 break; 1311 1312 /* 1313 * XXX if we are to allow other cases, we should really 1314 * be careful about scope here. 1315 * basically, we should disallow queries toward IPv6 1316 * destination X with subject Y, 1317 * if scope(X) > scope(Y). 1318 * if we allow scope(X) > scope(Y), it will result in 1319 * information leakage across scope boundary. 1320 */ 1321 goto bad; 1322 1323 case ICMP6_NI_SUBJ_FQDN: 1324 /* 1325 * Validate Subject name with gethostname(3). 1326 * 1327 * The behavior may need some debate, since: 1328 * - we are not sure if the node has FQDN as 1329 * hostname (returned by gethostname(3)). 1330 * - the code does wildcard match for truncated names. 1331 * however, we are not sure if we want to perform 1332 * wildcard match, if gethostname(3) side has 1333 * truncated hostname. 1334 */ 1335 pr = curthread->td_ucred->cr_prison; 1336 mtx_lock(&pr->pr_mtx); 1337 n = ni6_nametodns(pr->pr_hostname, 1338 strlen(pr->pr_hostname), 0); 1339 mtx_unlock(&pr->pr_mtx); 1340 if (!n || n->m_next || n->m_len == 0) 1341 goto bad; 1342 IP6_EXTHDR_GET(subj, char *, m, 1343 off + sizeof(struct icmp6_nodeinfo), subjlen); 1344 if (subj == NULL) 1345 goto bad; 1346 if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *), 1347 n->m_len)) { 1348 goto bad; 1349 } 1350 m_freem(n); 1351 n = NULL; 1352 break; 1353 1354 case ICMP6_NI_SUBJ_IPV4: /* XXX: to be implemented? */ 1355 default: 1356 goto bad; 1357 } 1358 break; 1359 } 1360 1361 /* refuse based on configuration. XXX ICMP6_NI_REFUSED? */ 1362 switch (qtype) { 1363 case NI_QTYPE_FQDN: 1364 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_FQDNOK) == 0) 1365 goto bad; 1366 break; 1367 case NI_QTYPE_NODEADDR: 1368 case NI_QTYPE_IPV4ADDR: 1369 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_NODEADDROK) == 0) 1370 goto bad; 1371 break; 1372 } 1373 1374 /* guess reply length */ 1375 switch (qtype) { 1376 case NI_QTYPE_NOOP: 1377 break; /* no reply data */ 1378 case NI_QTYPE_SUPTYPES: 1379 replylen += sizeof(u_int32_t); 1380 break; 1381 case NI_QTYPE_FQDN: 1382 /* XXX will append an mbuf */ 1383 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); 1384 break; 1385 case NI_QTYPE_NODEADDR: 1386 addrs = ni6_addrs(ni6, m, &ifp, (struct in6_addr *)subj); 1387 if ((replylen += addrs * (sizeof(struct in6_addr) + 1388 sizeof(u_int32_t))) > MCLBYTES) 1389 replylen = MCLBYTES; /* XXX: will truncate pkt later */ 1390 break; 1391 case NI_QTYPE_IPV4ADDR: 1392 /* unsupported - should respond with unknown Qtype? */ 1393 break; 1394 default: 1395 /* 1396 * XXX: We must return a reply with the ICMP6 code 1397 * `unknown Qtype' in this case. However we regard the case 1398 * as an FQDN query for backward compatibility. 1399 * Older versions set a random value to this field, 1400 * so it rarely varies in the defined qtypes. 1401 * But the mechanism is not reliable... 1402 * maybe we should obsolete older versions. 1403 */ 1404 qtype = NI_QTYPE_FQDN; 1405 /* XXX will append an mbuf */ 1406 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); 1407 oldfqdn++; 1408 break; 1409 } 1410 1411 /* allocate an mbuf to reply. */ 1412 MGETHDR(n, M_DONTWAIT, m->m_type); 1413 if (n == NULL) { 1414 m_freem(m); 1415 return (NULL); 1416 } 1417 M_MOVE_PKTHDR(n, m); /* just for recvif */ 1418 if (replylen > MHLEN) { 1419 if (replylen > MCLBYTES) { 1420 /* 1421 * XXX: should we try to allocate more? But MCLBYTES 1422 * is probably much larger than IPV6_MMTU... 1423 */ 1424 goto bad; 1425 } 1426 MCLGET(n, M_DONTWAIT); 1427 if ((n->m_flags & M_EXT) == 0) { 1428 goto bad; 1429 } 1430 } 1431 n->m_pkthdr.len = n->m_len = replylen; 1432 1433 /* copy mbuf header and IPv6 + Node Information base headers */ 1434 bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr)); 1435 nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1); 1436 bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo)); 1437 1438 /* qtype dependent procedure */ 1439 switch (qtype) { 1440 case NI_QTYPE_NOOP: 1441 nni6->ni_code = ICMP6_NI_SUCCESS; 1442 nni6->ni_flags = 0; 1443 break; 1444 case NI_QTYPE_SUPTYPES: 1445 { 1446 u_int32_t v; 1447 nni6->ni_code = ICMP6_NI_SUCCESS; 1448 nni6->ni_flags = htons(0x0000); /* raw bitmap */ 1449 /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */ 1450 v = (u_int32_t)htonl(0x0000000f); 1451 bcopy(&v, nni6 + 1, sizeof(u_int32_t)); 1452 break; 1453 } 1454 case NI_QTYPE_FQDN: 1455 nni6->ni_code = ICMP6_NI_SUCCESS; 1456 fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) + 1457 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo)); 1458 nni6->ni_flags = 0; /* XXX: meaningless TTL */ 1459 fqdn->ni_fqdn_ttl = 0; /* ditto. */ 1460 /* 1461 * XXX do we really have FQDN in hostname? 1462 */ 1463 pr = curthread->td_ucred->cr_prison; 1464 mtx_lock(&pr->pr_mtx); 1465 n->m_next = ni6_nametodns(pr->pr_hostname, 1466 strlen(pr->pr_hostname), oldfqdn); 1467 mtx_unlock(&pr->pr_mtx); 1468 if (n->m_next == NULL) 1469 goto bad; 1470 /* XXX we assume that n->m_next is not a chain */ 1471 if (n->m_next->m_next != NULL) 1472 goto bad; 1473 n->m_pkthdr.len += n->m_next->m_len; 1474 break; 1475 case NI_QTYPE_NODEADDR: 1476 { 1477 int lenlim, copied; 1478 1479 nni6->ni_code = ICMP6_NI_SUCCESS; 1480 n->m_pkthdr.len = n->m_len = 1481 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); 1482 lenlim = M_TRAILINGSPACE(n); 1483 copied = ni6_store_addrs(ni6, nni6, ifp, lenlim); 1484 /* XXX: reset mbuf length */ 1485 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + 1486 sizeof(struct icmp6_nodeinfo) + copied; 1487 break; 1488 } 1489 default: 1490 break; /* XXX impossible! */ 1491 } 1492 1493 nni6->ni_type = ICMP6_NI_REPLY; 1494 m_freem(m); 1495 return (n); 1496 1497 bad: 1498 m_freem(m); 1499 if (n) 1500 m_freem(n); 1501 return (NULL); 1502 } 1503 1504 /* 1505 * make a mbuf with DNS-encoded string. no compression support. 1506 * 1507 * XXX names with less than 2 dots (like "foo" or "foo.section") will be 1508 * treated as truncated name (two \0 at the end). this is a wild guess. 1509 * 1510 * old - return pascal string if non-zero 1511 */ 1512 static struct mbuf * 1513 ni6_nametodns(const char *name, int namelen, int old) 1514 { 1515 struct mbuf *m; 1516 char *cp, *ep; 1517 const char *p, *q; 1518 int i, len, nterm; 1519 1520 if (old) 1521 len = namelen + 1; 1522 else 1523 len = MCLBYTES; 1524 1525 /* because MAXHOSTNAMELEN is usually 256, we use cluster mbuf */ 1526 MGET(m, M_DONTWAIT, MT_DATA); 1527 if (m && len > MLEN) { 1528 MCLGET(m, M_DONTWAIT); 1529 if ((m->m_flags & M_EXT) == 0) 1530 goto fail; 1531 } 1532 if (!m) 1533 goto fail; 1534 m->m_next = NULL; 1535 1536 if (old) { 1537 m->m_len = len; 1538 *mtod(m, char *) = namelen; 1539 bcopy(name, mtod(m, char *) + 1, namelen); 1540 return m; 1541 } else { 1542 m->m_len = 0; 1543 cp = mtod(m, char *); 1544 ep = mtod(m, char *) + M_TRAILINGSPACE(m); 1545 1546 /* if not certain about my name, return empty buffer */ 1547 if (namelen == 0) 1548 return m; 1549 1550 /* 1551 * guess if it looks like shortened hostname, or FQDN. 1552 * shortened hostname needs two trailing "\0". 1553 */ 1554 i = 0; 1555 for (p = name; p < name + namelen; p++) { 1556 if (*p && *p == '.') 1557 i++; 1558 } 1559 if (i < 2) 1560 nterm = 2; 1561 else 1562 nterm = 1; 1563 1564 p = name; 1565 while (cp < ep && p < name + namelen) { 1566 i = 0; 1567 for (q = p; q < name + namelen && *q && *q != '.'; q++) 1568 i++; 1569 /* result does not fit into mbuf */ 1570 if (cp + i + 1 >= ep) 1571 goto fail; 1572 /* 1573 * DNS label length restriction, RFC1035 page 8. 1574 * "i == 0" case is included here to avoid returning 1575 * 0-length label on "foo..bar". 1576 */ 1577 if (i <= 0 || i >= 64) 1578 goto fail; 1579 *cp++ = i; 1580 bcopy(p, cp, i); 1581 cp += i; 1582 p = q; 1583 if (p < name + namelen && *p == '.') 1584 p++; 1585 } 1586 /* termination */ 1587 if (cp + nterm >= ep) 1588 goto fail; 1589 while (nterm-- > 0) 1590 *cp++ = '\0'; 1591 m->m_len = cp - mtod(m, char *); 1592 return m; 1593 } 1594 1595 panic("should not reach here"); 1596 /* NOTREACHED */ 1597 1598 fail: 1599 if (m) 1600 m_freem(m); 1601 return NULL; 1602 } 1603 1604 /* 1605 * check if two DNS-encoded string matches. takes care of truncated 1606 * form (with \0\0 at the end). no compression support. 1607 * XXX upper/lowercase match (see RFC2065) 1608 */ 1609 static int 1610 ni6_dnsmatch(const char *a, int alen, const char *b, int blen) 1611 { 1612 const char *a0, *b0; 1613 int l; 1614 1615 /* simplest case - need validation? */ 1616 if (alen == blen && bcmp(a, b, alen) == 0) 1617 return 1; 1618 1619 a0 = a; 1620 b0 = b; 1621 1622 /* termination is mandatory */ 1623 if (alen < 2 || blen < 2) 1624 return 0; 1625 if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0') 1626 return 0; 1627 alen--; 1628 blen--; 1629 1630 while (a - a0 < alen && b - b0 < blen) { 1631 if (a - a0 + 1 > alen || b - b0 + 1 > blen) 1632 return 0; 1633 1634 if ((signed char)a[0] < 0 || (signed char)b[0] < 0) 1635 return 0; 1636 /* we don't support compression yet */ 1637 if (a[0] >= 64 || b[0] >= 64) 1638 return 0; 1639 1640 /* truncated case */ 1641 if (a[0] == 0 && a - a0 == alen - 1) 1642 return 1; 1643 if (b[0] == 0 && b - b0 == blen - 1) 1644 return 1; 1645 if (a[0] == 0 || b[0] == 0) 1646 return 0; 1647 1648 if (a[0] != b[0]) 1649 return 0; 1650 l = a[0]; 1651 if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen) 1652 return 0; 1653 if (bcmp(a + 1, b + 1, l) != 0) 1654 return 0; 1655 1656 a += 1 + l; 1657 b += 1 + l; 1658 } 1659 1660 if (a - a0 == alen && b - b0 == blen) 1661 return 1; 1662 else 1663 return 0; 1664 } 1665 1666 /* 1667 * calculate the number of addresses to be returned in the node info reply. 1668 */ 1669 static int 1670 ni6_addrs(struct icmp6_nodeinfo *ni6, struct mbuf *m, struct ifnet **ifpp, 1671 struct in6_addr *subj) 1672 { 1673 struct ifnet *ifp; 1674 struct in6_ifaddr *ifa6; 1675 struct ifaddr *ifa; 1676 int addrs = 0, addrsofif, iffound = 0; 1677 int niflags = ni6->ni_flags; 1678 1679 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) { 1680 switch (ni6->ni_code) { 1681 case ICMP6_NI_SUBJ_IPV6: 1682 if (subj == NULL) /* must be impossible... */ 1683 return (0); 1684 break; 1685 default: 1686 /* 1687 * XXX: we only support IPv6 subject address for 1688 * this Qtype. 1689 */ 1690 return (0); 1691 } 1692 } 1693 1694 IFNET_RLOCK(); 1695 for (ifp = TAILQ_FIRST(&V_ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list)) { 1696 addrsofif = 0; 1697 IF_ADDR_LOCK(ifp); 1698 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 1699 if (ifa->ifa_addr->sa_family != AF_INET6) 1700 continue; 1701 ifa6 = (struct in6_ifaddr *)ifa; 1702 1703 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 && 1704 IN6_ARE_ADDR_EQUAL(subj, &ifa6->ia_addr.sin6_addr)) 1705 iffound = 1; 1706 1707 /* 1708 * IPv4-mapped addresses can only be returned by a 1709 * Node Information proxy, since they represent 1710 * addresses of IPv4-only nodes, which perforce do 1711 * not implement this protocol. 1712 * [icmp-name-lookups-07, Section 5.4] 1713 * So we don't support NI_NODEADDR_FLAG_COMPAT in 1714 * this function at this moment. 1715 */ 1716 1717 /* What do we have to do about ::1? */ 1718 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { 1719 case IPV6_ADDR_SCOPE_LINKLOCAL: 1720 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) 1721 continue; 1722 break; 1723 case IPV6_ADDR_SCOPE_SITELOCAL: 1724 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) 1725 continue; 1726 break; 1727 case IPV6_ADDR_SCOPE_GLOBAL: 1728 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) 1729 continue; 1730 break; 1731 default: 1732 continue; 1733 } 1734 1735 /* 1736 * check if anycast is okay. 1737 * XXX: just experimental. not in the spec. 1738 */ 1739 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && 1740 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) 1741 continue; /* we need only unicast addresses */ 1742 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && 1743 (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) { 1744 continue; 1745 } 1746 addrsofif++; /* count the address */ 1747 } 1748 IF_ADDR_UNLOCK(ifp); 1749 if (iffound) { 1750 *ifpp = ifp; 1751 IFNET_RUNLOCK(); 1752 return (addrsofif); 1753 } 1754 1755 addrs += addrsofif; 1756 } 1757 IFNET_RUNLOCK(); 1758 1759 return (addrs); 1760 } 1761 1762 static int 1763 ni6_store_addrs(struct icmp6_nodeinfo *ni6, struct icmp6_nodeinfo *nni6, 1764 struct ifnet *ifp0, int resid) 1765 { 1766 struct ifnet *ifp = ifp0 ? ifp0 : TAILQ_FIRST(&V_ifnet); 1767 struct in6_ifaddr *ifa6; 1768 struct ifaddr *ifa; 1769 struct ifnet *ifp_dep = NULL; 1770 int copied = 0, allow_deprecated = 0; 1771 u_char *cp = (u_char *)(nni6 + 1); 1772 int niflags = ni6->ni_flags; 1773 u_int32_t ltime; 1774 1775 if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL)) 1776 return (0); /* needless to copy */ 1777 1778 IFNET_RLOCK(); 1779 again: 1780 1781 for (; ifp; ifp = TAILQ_NEXT(ifp, if_list)) { 1782 IF_ADDR_LOCK(ifp); 1783 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 1784 if (ifa->ifa_addr->sa_family != AF_INET6) 1785 continue; 1786 ifa6 = (struct in6_ifaddr *)ifa; 1787 1788 if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 && 1789 allow_deprecated == 0) { 1790 /* 1791 * prefererred address should be put before 1792 * deprecated addresses. 1793 */ 1794 1795 /* record the interface for later search */ 1796 if (ifp_dep == NULL) 1797 ifp_dep = ifp; 1798 1799 continue; 1800 } else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 && 1801 allow_deprecated != 0) 1802 continue; /* we now collect deprecated addrs */ 1803 1804 /* What do we have to do about ::1? */ 1805 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { 1806 case IPV6_ADDR_SCOPE_LINKLOCAL: 1807 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) 1808 continue; 1809 break; 1810 case IPV6_ADDR_SCOPE_SITELOCAL: 1811 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) 1812 continue; 1813 break; 1814 case IPV6_ADDR_SCOPE_GLOBAL: 1815 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) 1816 continue; 1817 break; 1818 default: 1819 continue; 1820 } 1821 1822 /* 1823 * check if anycast is okay. 1824 * XXX: just experimental. not in the spec. 1825 */ 1826 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && 1827 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) 1828 continue; 1829 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && 1830 (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) { 1831 continue; 1832 } 1833 1834 /* now we can copy the address */ 1835 if (resid < sizeof(struct in6_addr) + 1836 sizeof(u_int32_t)) { 1837 IF_ADDR_UNLOCK(ifp); 1838 /* 1839 * We give up much more copy. 1840 * Set the truncate flag and return. 1841 */ 1842 nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE; 1843 IFNET_RUNLOCK(); 1844 return (copied); 1845 } 1846 1847 /* 1848 * Set the TTL of the address. 1849 * The TTL value should be one of the following 1850 * according to the specification: 1851 * 1852 * 1. The remaining lifetime of a DHCP lease on the 1853 * address, or 1854 * 2. The remaining Valid Lifetime of a prefix from 1855 * which the address was derived through Stateless 1856 * Autoconfiguration. 1857 * 1858 * Note that we currently do not support stateful 1859 * address configuration by DHCPv6, so the former 1860 * case can't happen. 1861 */ 1862 if (ifa6->ia6_lifetime.ia6t_expire == 0) 1863 ltime = ND6_INFINITE_LIFETIME; 1864 else { 1865 if (ifa6->ia6_lifetime.ia6t_expire > 1866 time_second) 1867 ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_second); 1868 else 1869 ltime = 0; 1870 } 1871 1872 bcopy(<ime, cp, sizeof(u_int32_t)); 1873 cp += sizeof(u_int32_t); 1874 1875 /* copy the address itself */ 1876 bcopy(&ifa6->ia_addr.sin6_addr, cp, 1877 sizeof(struct in6_addr)); 1878 in6_clearscope((struct in6_addr *)cp); /* XXX */ 1879 cp += sizeof(struct in6_addr); 1880 1881 resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t)); 1882 copied += (sizeof(struct in6_addr) + sizeof(u_int32_t)); 1883 } 1884 IF_ADDR_UNLOCK(ifp); 1885 if (ifp0) /* we need search only on the specified IF */ 1886 break; 1887 } 1888 1889 if (allow_deprecated == 0 && ifp_dep != NULL) { 1890 ifp = ifp_dep; 1891 allow_deprecated = 1; 1892 1893 goto again; 1894 } 1895 1896 IFNET_RUNLOCK(); 1897 1898 return (copied); 1899 } 1900 1901 /* 1902 * XXX almost dup'ed code with rip6_input. 1903 */ 1904 static int 1905 icmp6_rip6_input(struct mbuf **mp, int off) 1906 { 1907 struct mbuf *m = *mp; 1908 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1909 struct inpcb *in6p; 1910 struct inpcb *last = NULL; 1911 struct sockaddr_in6 fromsa; 1912 struct icmp6_hdr *icmp6; 1913 struct mbuf *opts = NULL; 1914 1915 #ifndef PULLDOWN_TEST 1916 /* this is assumed to be safe. */ 1917 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off); 1918 #else 1919 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6)); 1920 if (icmp6 == NULL) { 1921 /* m is already reclaimed */ 1922 return (IPPROTO_DONE); 1923 } 1924 #endif 1925 1926 /* 1927 * XXX: the address may have embedded scope zone ID, which should be 1928 * hidden from applications. 1929 */ 1930 bzero(&fromsa, sizeof(fromsa)); 1931 fromsa.sin6_family = AF_INET6; 1932 fromsa.sin6_len = sizeof(struct sockaddr_in6); 1933 fromsa.sin6_addr = ip6->ip6_src; 1934 if (sa6_recoverscope(&fromsa)) { 1935 m_freem(m); 1936 return (IPPROTO_DONE); 1937 } 1938 1939 INP_INFO_RLOCK(&V_ripcbinfo); 1940 LIST_FOREACH(in6p, &V_ripcb, inp_list) { 1941 if ((in6p->inp_vflag & INP_IPV6) == 0) 1942 continue; 1943 if (in6p->inp_ip_p != IPPROTO_ICMPV6) 1944 continue; 1945 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) && 1946 !IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &ip6->ip6_dst)) 1947 continue; 1948 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr) && 1949 !IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src)) 1950 continue; 1951 INP_RLOCK(in6p); 1952 if (ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type, 1953 in6p->in6p_icmp6filt)) { 1954 INP_RUNLOCK(in6p); 1955 continue; 1956 } 1957 if (last != NULL) { 1958 struct mbuf *n = NULL; 1959 1960 /* 1961 * Recent network drivers tend to allocate a single 1962 * mbuf cluster, rather than to make a couple of 1963 * mbufs without clusters. Also, since the IPv6 code 1964 * path tries to avoid m_pullup(), it is highly 1965 * probable that we still have an mbuf cluster here 1966 * even though the necessary length can be stored in an 1967 * mbuf's internal buffer. 1968 * Meanwhile, the default size of the receive socket 1969 * buffer for raw sockets is not so large. This means 1970 * the possibility of packet loss is relatively higher 1971 * than before. To avoid this scenario, we copy the 1972 * received data to a separate mbuf that does not use 1973 * a cluster, if possible. 1974 * XXX: it is better to copy the data after stripping 1975 * intermediate headers. 1976 */ 1977 if ((m->m_flags & M_EXT) && m->m_next == NULL && 1978 m->m_len <= MHLEN) { 1979 MGET(n, M_DONTWAIT, m->m_type); 1980 if (n != NULL) { 1981 if (m_dup_pkthdr(n, m, M_NOWAIT)) { 1982 bcopy(m->m_data, n->m_data, 1983 m->m_len); 1984 n->m_len = m->m_len; 1985 } else { 1986 m_free(n); 1987 n = NULL; 1988 } 1989 } 1990 } 1991 if (n != NULL || 1992 (n = m_copy(m, 0, (int)M_COPYALL)) != NULL) { 1993 if (last->inp_flags & INP_CONTROLOPTS) 1994 ip6_savecontrol(last, n, &opts); 1995 /* strip intermediate headers */ 1996 m_adj(n, off); 1997 SOCKBUF_LOCK(&last->inp_socket->so_rcv); 1998 if (sbappendaddr_locked( 1999 &last->inp_socket->so_rcv, 2000 (struct sockaddr *)&fromsa, n, opts) 2001 == 0) { 2002 /* should notify about lost packet */ 2003 m_freem(n); 2004 if (opts) { 2005 m_freem(opts); 2006 } 2007 SOCKBUF_UNLOCK( 2008 &last->inp_socket->so_rcv); 2009 } else 2010 sorwakeup_locked(last->inp_socket); 2011 opts = NULL; 2012 } 2013 INP_RUNLOCK(last); 2014 } 2015 last = in6p; 2016 } 2017 INP_INFO_RUNLOCK(&V_ripcbinfo); 2018 if (last != NULL) { 2019 if (last->inp_flags & INP_CONTROLOPTS) 2020 ip6_savecontrol(last, m, &opts); 2021 /* strip intermediate headers */ 2022 m_adj(m, off); 2023 2024 /* avoid using mbuf clusters if possible (see above) */ 2025 if ((m->m_flags & M_EXT) && m->m_next == NULL && 2026 m->m_len <= MHLEN) { 2027 struct mbuf *n; 2028 2029 MGET(n, M_DONTWAIT, m->m_type); 2030 if (n != NULL) { 2031 if (m_dup_pkthdr(n, m, M_NOWAIT)) { 2032 bcopy(m->m_data, n->m_data, m->m_len); 2033 n->m_len = m->m_len; 2034 2035 m_freem(m); 2036 m = n; 2037 } else { 2038 m_freem(n); 2039 n = NULL; 2040 } 2041 } 2042 } 2043 SOCKBUF_LOCK(&last->inp_socket->so_rcv); 2044 if (sbappendaddr_locked(&last->inp_socket->so_rcv, 2045 (struct sockaddr *)&fromsa, m, opts) == 0) { 2046 m_freem(m); 2047 if (opts) 2048 m_freem(opts); 2049 SOCKBUF_UNLOCK(&last->inp_socket->so_rcv); 2050 } else 2051 sorwakeup_locked(last->inp_socket); 2052 INP_RUNLOCK(last); 2053 } else { 2054 m_freem(m); 2055 IP6STAT_DEC(ip6s_delivered); 2056 } 2057 return IPPROTO_DONE; 2058 } 2059 2060 /* 2061 * Reflect the ip6 packet back to the source. 2062 * OFF points to the icmp6 header, counted from the top of the mbuf. 2063 */ 2064 void 2065 icmp6_reflect(struct mbuf *m, size_t off) 2066 { 2067 struct ip6_hdr *ip6; 2068 struct icmp6_hdr *icmp6; 2069 struct in6_ifaddr *ia = NULL; 2070 int plen; 2071 int type, code; 2072 struct ifnet *outif = NULL; 2073 struct in6_addr origdst, src, *srcp = NULL; 2074 2075 /* too short to reflect */ 2076 if (off < sizeof(struct ip6_hdr)) { 2077 nd6log((LOG_DEBUG, 2078 "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n", 2079 (u_long)off, (u_long)sizeof(struct ip6_hdr), 2080 __FILE__, __LINE__)); 2081 goto bad; 2082 } 2083 2084 /* 2085 * If there are extra headers between IPv6 and ICMPv6, strip 2086 * off that header first. 2087 */ 2088 #ifdef DIAGNOSTIC 2089 if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN) 2090 panic("assumption failed in icmp6_reflect"); 2091 #endif 2092 if (off > sizeof(struct ip6_hdr)) { 2093 size_t l; 2094 struct ip6_hdr nip6; 2095 2096 l = off - sizeof(struct ip6_hdr); 2097 m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6); 2098 m_adj(m, l); 2099 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 2100 if (m->m_len < l) { 2101 if ((m = m_pullup(m, l)) == NULL) 2102 return; 2103 } 2104 bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6)); 2105 } else /* off == sizeof(struct ip6_hdr) */ { 2106 size_t l; 2107 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 2108 if (m->m_len < l) { 2109 if ((m = m_pullup(m, l)) == NULL) 2110 return; 2111 } 2112 } 2113 plen = m->m_pkthdr.len - sizeof(struct ip6_hdr); 2114 ip6 = mtod(m, struct ip6_hdr *); 2115 ip6->ip6_nxt = IPPROTO_ICMPV6; 2116 icmp6 = (struct icmp6_hdr *)(ip6 + 1); 2117 type = icmp6->icmp6_type; /* keep type for statistics */ 2118 code = icmp6->icmp6_code; /* ditto. */ 2119 2120 origdst = ip6->ip6_dst; 2121 /* 2122 * ip6_input() drops a packet if its src is multicast. 2123 * So, the src is never multicast. 2124 */ 2125 ip6->ip6_dst = ip6->ip6_src; 2126 2127 /* 2128 * If the incoming packet was addressed directly to us (i.e. unicast), 2129 * use dst as the src for the reply. 2130 * The IN6_IFF_NOTREADY case should be VERY rare, but is possible 2131 * (for example) when we encounter an error while forwarding procedure 2132 * destined to a duplicated address of ours. 2133 * Note that ip6_getdstifaddr() may fail if we are in an error handling 2134 * procedure of an outgoing packet of our own, in which case we need 2135 * to search in the ifaddr list. 2136 */ 2137 if (!IN6_IS_ADDR_MULTICAST(&origdst)) { 2138 if ((ia = ip6_getdstifaddr(m))) { 2139 if (!(ia->ia6_flags & 2140 (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) 2141 srcp = &ia->ia_addr.sin6_addr; 2142 } else { 2143 struct sockaddr_in6 d; 2144 2145 bzero(&d, sizeof(d)); 2146 d.sin6_family = AF_INET6; 2147 d.sin6_len = sizeof(d); 2148 d.sin6_addr = origdst; 2149 ia = (struct in6_ifaddr *) 2150 ifa_ifwithaddr((struct sockaddr *)&d); 2151 if (ia && 2152 !(ia->ia6_flags & 2153 (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) { 2154 srcp = &ia->ia_addr.sin6_addr; 2155 } 2156 } 2157 } 2158 2159 if (srcp == NULL) { 2160 int e; 2161 struct sockaddr_in6 sin6; 2162 struct route_in6 ro; 2163 2164 /* 2165 * This case matches to multicasts, our anycast, or unicasts 2166 * that we do not own. Select a source address based on the 2167 * source address of the erroneous packet. 2168 */ 2169 bzero(&sin6, sizeof(sin6)); 2170 sin6.sin6_family = AF_INET6; 2171 sin6.sin6_len = sizeof(sin6); 2172 sin6.sin6_addr = ip6->ip6_dst; /* zone ID should be embedded */ 2173 2174 bzero(&ro, sizeof(ro)); 2175 e = in6_selectsrc(&sin6, NULL, NULL, &ro, NULL, &outif, &src); 2176 if (ro.ro_rt) 2177 RTFREE(ro.ro_rt); /* XXX: we could use this */ 2178 if (e) { 2179 char ip6buf[INET6_ADDRSTRLEN]; 2180 nd6log((LOG_DEBUG, 2181 "icmp6_reflect: source can't be determined: " 2182 "dst=%s, error=%d\n", 2183 ip6_sprintf(ip6buf, &sin6.sin6_addr), e)); 2184 goto bad; 2185 } 2186 srcp = &src; 2187 } 2188 2189 ip6->ip6_src = *srcp; 2190 ip6->ip6_flow = 0; 2191 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2192 ip6->ip6_vfc |= IPV6_VERSION; 2193 ip6->ip6_nxt = IPPROTO_ICMPV6; 2194 if (outif) 2195 ip6->ip6_hlim = ND_IFINFO(outif)->chlim; 2196 else if (m->m_pkthdr.rcvif) { 2197 /* XXX: This may not be the outgoing interface */ 2198 ip6->ip6_hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim; 2199 } else 2200 ip6->ip6_hlim = V_ip6_defhlim; 2201 2202 icmp6->icmp6_cksum = 0; 2203 icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2204 sizeof(struct ip6_hdr), plen); 2205 2206 /* 2207 * XXX option handling 2208 */ 2209 2210 m->m_flags &= ~(M_BCAST|M_MCAST); 2211 2212 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2213 if (outif) 2214 icmp6_ifoutstat_inc(outif, type, code); 2215 2216 if (ia != NULL) 2217 ifa_free(&ia->ia_ifa); 2218 return; 2219 2220 bad: 2221 if (ia != NULL) 2222 ifa_free(&ia->ia_ifa); 2223 m_freem(m); 2224 return; 2225 } 2226 2227 void 2228 icmp6_fasttimo(void) 2229 { 2230 2231 mld_fasttimo(); 2232 } 2233 2234 void 2235 icmp6_slowtimo(void) 2236 { 2237 2238 mld_slowtimo(); 2239 } 2240 2241 static const char * 2242 icmp6_redirect_diag(struct in6_addr *src6, struct in6_addr *dst6, 2243 struct in6_addr *tgt6) 2244 { 2245 static char buf[1024]; 2246 char ip6bufs[INET6_ADDRSTRLEN]; 2247 char ip6bufd[INET6_ADDRSTRLEN]; 2248 char ip6buft[INET6_ADDRSTRLEN]; 2249 snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)", 2250 ip6_sprintf(ip6bufs, src6), ip6_sprintf(ip6bufd, dst6), 2251 ip6_sprintf(ip6buft, tgt6)); 2252 return buf; 2253 } 2254 2255 void 2256 icmp6_redirect_input(struct mbuf *m, int off) 2257 { 2258 struct ifnet *ifp; 2259 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 2260 struct nd_redirect *nd_rd; 2261 int icmp6len = ntohs(ip6->ip6_plen); 2262 char *lladdr = NULL; 2263 int lladdrlen = 0; 2264 u_char *redirhdr = NULL; 2265 int redirhdrlen = 0; 2266 struct rtentry *rt = NULL; 2267 int is_router; 2268 int is_onlink; 2269 struct in6_addr src6 = ip6->ip6_src; 2270 struct in6_addr redtgt6; 2271 struct in6_addr reddst6; 2272 union nd_opts ndopts; 2273 char ip6buf[INET6_ADDRSTRLEN]; 2274 2275 if (!m) 2276 return; 2277 2278 ifp = m->m_pkthdr.rcvif; 2279 2280 if (!ifp) 2281 return; 2282 2283 /* XXX if we are router, we don't update route by icmp6 redirect */ 2284 if (V_ip6_forwarding) 2285 goto freeit; 2286 if (!V_icmp6_rediraccept) 2287 goto freeit; 2288 2289 #ifndef PULLDOWN_TEST 2290 IP6_EXTHDR_CHECK(m, off, icmp6len,); 2291 nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off); 2292 #else 2293 IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len); 2294 if (nd_rd == NULL) { 2295 ICMP6STAT_INC(icp6s_tooshort); 2296 return; 2297 } 2298 #endif 2299 redtgt6 = nd_rd->nd_rd_target; 2300 reddst6 = nd_rd->nd_rd_dst; 2301 2302 if (in6_setscope(&redtgt6, m->m_pkthdr.rcvif, NULL) || 2303 in6_setscope(&reddst6, m->m_pkthdr.rcvif, NULL)) { 2304 goto freeit; 2305 } 2306 2307 /* validation */ 2308 if (!IN6_IS_ADDR_LINKLOCAL(&src6)) { 2309 nd6log((LOG_ERR, 2310 "ICMP6 redirect sent from %s rejected; " 2311 "must be from linklocal\n", 2312 ip6_sprintf(ip6buf, &src6))); 2313 goto bad; 2314 } 2315 if (ip6->ip6_hlim != 255) { 2316 nd6log((LOG_ERR, 2317 "ICMP6 redirect sent from %s rejected; " 2318 "hlim=%d (must be 255)\n", 2319 ip6_sprintf(ip6buf, &src6), ip6->ip6_hlim)); 2320 goto bad; 2321 } 2322 { 2323 /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */ 2324 struct sockaddr_in6 sin6; 2325 struct in6_addr *gw6; 2326 2327 bzero(&sin6, sizeof(sin6)); 2328 sin6.sin6_family = AF_INET6; 2329 sin6.sin6_len = sizeof(struct sockaddr_in6); 2330 bcopy(&reddst6, &sin6.sin6_addr, sizeof(reddst6)); 2331 rt = rtalloc1((struct sockaddr *)&sin6, 0, 0UL); 2332 if (rt) { 2333 if (rt->rt_gateway == NULL || 2334 rt->rt_gateway->sa_family != AF_INET6) { 2335 nd6log((LOG_ERR, 2336 "ICMP6 redirect rejected; no route " 2337 "with inet6 gateway found for redirect dst: %s\n", 2338 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2339 RTFREE_LOCKED(rt); 2340 goto bad; 2341 } 2342 2343 gw6 = &(((struct sockaddr_in6 *)rt->rt_gateway)->sin6_addr); 2344 if (bcmp(&src6, gw6, sizeof(struct in6_addr)) != 0) { 2345 nd6log((LOG_ERR, 2346 "ICMP6 redirect rejected; " 2347 "not equal to gw-for-src=%s (must be same): " 2348 "%s\n", 2349 ip6_sprintf(ip6buf, gw6), 2350 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2351 RTFREE_LOCKED(rt); 2352 goto bad; 2353 } 2354 } else { 2355 nd6log((LOG_ERR, 2356 "ICMP6 redirect rejected; " 2357 "no route found for redirect dst: %s\n", 2358 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2359 goto bad; 2360 } 2361 RTFREE_LOCKED(rt); 2362 rt = NULL; 2363 } 2364 if (IN6_IS_ADDR_MULTICAST(&reddst6)) { 2365 nd6log((LOG_ERR, 2366 "ICMP6 redirect rejected; " 2367 "redirect dst must be unicast: %s\n", 2368 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2369 goto bad; 2370 } 2371 2372 is_router = is_onlink = 0; 2373 if (IN6_IS_ADDR_LINKLOCAL(&redtgt6)) 2374 is_router = 1; /* router case */ 2375 if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0) 2376 is_onlink = 1; /* on-link destination case */ 2377 if (!is_router && !is_onlink) { 2378 nd6log((LOG_ERR, 2379 "ICMP6 redirect rejected; " 2380 "neither router case nor onlink case: %s\n", 2381 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2382 goto bad; 2383 } 2384 /* validation passed */ 2385 2386 icmp6len -= sizeof(*nd_rd); 2387 nd6_option_init(nd_rd + 1, icmp6len, &ndopts); 2388 if (nd6_options(&ndopts) < 0) { 2389 nd6log((LOG_INFO, "icmp6_redirect_input: " 2390 "invalid ND option, rejected: %s\n", 2391 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2392 /* nd6_options have incremented stats */ 2393 goto freeit; 2394 } 2395 2396 if (ndopts.nd_opts_tgt_lladdr) { 2397 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 2398 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 2399 } 2400 2401 if (ndopts.nd_opts_rh) { 2402 redirhdrlen = ndopts.nd_opts_rh->nd_opt_rh_len; 2403 redirhdr = (u_char *)(ndopts.nd_opts_rh + 1); /* xxx */ 2404 } 2405 2406 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 2407 nd6log((LOG_INFO, 2408 "icmp6_redirect_input: lladdrlen mismatch for %s " 2409 "(if %d, icmp6 packet %d): %s\n", 2410 ip6_sprintf(ip6buf, &redtgt6), 2411 ifp->if_addrlen, lladdrlen - 2, 2412 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2413 goto bad; 2414 } 2415 2416 /* RFC 2461 8.3 */ 2417 nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT, 2418 is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER); 2419 2420 if (!is_onlink) { /* better router case. perform rtredirect. */ 2421 /* perform rtredirect */ 2422 struct sockaddr_in6 sdst; 2423 struct sockaddr_in6 sgw; 2424 struct sockaddr_in6 ssrc; 2425 2426 bzero(&sdst, sizeof(sdst)); 2427 bzero(&sgw, sizeof(sgw)); 2428 bzero(&ssrc, sizeof(ssrc)); 2429 sdst.sin6_family = sgw.sin6_family = ssrc.sin6_family = AF_INET6; 2430 sdst.sin6_len = sgw.sin6_len = ssrc.sin6_len = 2431 sizeof(struct sockaddr_in6); 2432 bcopy(&redtgt6, &sgw.sin6_addr, sizeof(struct in6_addr)); 2433 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr)); 2434 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr)); 2435 rtredirect((struct sockaddr *)&sdst, (struct sockaddr *)&sgw, 2436 (struct sockaddr *)NULL, RTF_GATEWAY | RTF_HOST, 2437 (struct sockaddr *)&ssrc); 2438 } 2439 /* finally update cached route in each socket via pfctlinput */ 2440 { 2441 struct sockaddr_in6 sdst; 2442 2443 bzero(&sdst, sizeof(sdst)); 2444 sdst.sin6_family = AF_INET6; 2445 sdst.sin6_len = sizeof(struct sockaddr_in6); 2446 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr)); 2447 pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst); 2448 #ifdef IPSEC 2449 key_sa_routechange((struct sockaddr *)&sdst); 2450 #endif /* IPSEC */ 2451 } 2452 2453 freeit: 2454 m_freem(m); 2455 return; 2456 2457 bad: 2458 ICMP6STAT_INC(icp6s_badredirect); 2459 m_freem(m); 2460 } 2461 2462 void 2463 icmp6_redirect_output(struct mbuf *m0, struct rtentry *rt) 2464 { 2465 struct ifnet *ifp; /* my outgoing interface */ 2466 struct in6_addr *ifp_ll6; 2467 struct in6_addr *router_ll6; 2468 struct ip6_hdr *sip6; /* m0 as struct ip6_hdr */ 2469 struct mbuf *m = NULL; /* newly allocated one */ 2470 struct ip6_hdr *ip6; /* m as struct ip6_hdr */ 2471 struct nd_redirect *nd_rd; 2472 struct llentry *ln = NULL; 2473 size_t maxlen; 2474 u_char *p; 2475 struct ifnet *outif = NULL; 2476 struct sockaddr_in6 src_sa; 2477 2478 icmp6_errcount(&V_icmp6stat.icp6s_outerrhist, ND_REDIRECT, 0); 2479 2480 /* if we are not router, we don't send icmp6 redirect */ 2481 if (!V_ip6_forwarding) 2482 goto fail; 2483 2484 /* sanity check */ 2485 if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp)) 2486 goto fail; 2487 2488 /* 2489 * Address check: 2490 * the source address must identify a neighbor, and 2491 * the destination address must not be a multicast address 2492 * [RFC 2461, sec 8.2] 2493 */ 2494 sip6 = mtod(m0, struct ip6_hdr *); 2495 bzero(&src_sa, sizeof(src_sa)); 2496 src_sa.sin6_family = AF_INET6; 2497 src_sa.sin6_len = sizeof(src_sa); 2498 src_sa.sin6_addr = sip6->ip6_src; 2499 if (nd6_is_addr_neighbor(&src_sa, ifp) == 0) 2500 goto fail; 2501 if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst)) 2502 goto fail; /* what should we do here? */ 2503 2504 /* rate limit */ 2505 if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0)) 2506 goto fail; 2507 2508 /* 2509 * Since we are going to append up to 1280 bytes (= IPV6_MMTU), 2510 * we almost always ask for an mbuf cluster for simplicity. 2511 * (MHLEN < IPV6_MMTU is almost always true) 2512 */ 2513 #if IPV6_MMTU >= MCLBYTES 2514 # error assumption failed about IPV6_MMTU and MCLBYTES 2515 #endif 2516 MGETHDR(m, M_DONTWAIT, MT_HEADER); 2517 if (m && IPV6_MMTU >= MHLEN) 2518 MCLGET(m, M_DONTWAIT); 2519 if (!m) 2520 goto fail; 2521 m->m_pkthdr.rcvif = NULL; 2522 m->m_len = 0; 2523 maxlen = M_TRAILINGSPACE(m); 2524 maxlen = min(IPV6_MMTU, maxlen); 2525 /* just for safety */ 2526 if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) + 2527 ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) { 2528 goto fail; 2529 } 2530 2531 { 2532 /* get ip6 linklocal address for ifp(my outgoing interface). */ 2533 struct in6_ifaddr *ia; 2534 if ((ia = in6ifa_ifpforlinklocal(ifp, 2535 IN6_IFF_NOTREADY| 2536 IN6_IFF_ANYCAST)) == NULL) 2537 goto fail; 2538 ifp_ll6 = &ia->ia_addr.sin6_addr; 2539 /* XXXRW: reference released prematurely. */ 2540 ifa_free(&ia->ia_ifa); 2541 } 2542 2543 /* get ip6 linklocal address for the router. */ 2544 if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) { 2545 struct sockaddr_in6 *sin6; 2546 sin6 = (struct sockaddr_in6 *)rt->rt_gateway; 2547 router_ll6 = &sin6->sin6_addr; 2548 if (!IN6_IS_ADDR_LINKLOCAL(router_ll6)) 2549 router_ll6 = (struct in6_addr *)NULL; 2550 } else 2551 router_ll6 = (struct in6_addr *)NULL; 2552 2553 /* ip6 */ 2554 ip6 = mtod(m, struct ip6_hdr *); 2555 ip6->ip6_flow = 0; 2556 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2557 ip6->ip6_vfc |= IPV6_VERSION; 2558 /* ip6->ip6_plen will be set later */ 2559 ip6->ip6_nxt = IPPROTO_ICMPV6; 2560 ip6->ip6_hlim = 255; 2561 /* ip6->ip6_src must be linklocal addr for my outgoing if. */ 2562 bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr)); 2563 bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr)); 2564 2565 /* ND Redirect */ 2566 nd_rd = (struct nd_redirect *)(ip6 + 1); 2567 nd_rd->nd_rd_type = ND_REDIRECT; 2568 nd_rd->nd_rd_code = 0; 2569 nd_rd->nd_rd_reserved = 0; 2570 if (rt->rt_flags & RTF_GATEWAY) { 2571 /* 2572 * nd_rd->nd_rd_target must be a link-local address in 2573 * better router cases. 2574 */ 2575 if (!router_ll6) 2576 goto fail; 2577 bcopy(router_ll6, &nd_rd->nd_rd_target, 2578 sizeof(nd_rd->nd_rd_target)); 2579 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2580 sizeof(nd_rd->nd_rd_dst)); 2581 } else { 2582 /* make sure redtgt == reddst */ 2583 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target, 2584 sizeof(nd_rd->nd_rd_target)); 2585 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2586 sizeof(nd_rd->nd_rd_dst)); 2587 } 2588 2589 p = (u_char *)(nd_rd + 1); 2590 2591 if (!router_ll6) 2592 goto nolladdropt; 2593 2594 { 2595 /* target lladdr option */ 2596 int len; 2597 struct nd_opt_hdr *nd_opt; 2598 char *lladdr; 2599 2600 IF_AFDATA_LOCK(ifp); 2601 ln = nd6_lookup(router_ll6, 0, ifp); 2602 IF_AFDATA_UNLOCK(ifp); 2603 if (ln == NULL) 2604 goto nolladdropt; 2605 2606 len = sizeof(*nd_opt) + ifp->if_addrlen; 2607 len = (len + 7) & ~7; /* round by 8 */ 2608 /* safety check */ 2609 if (len + (p - (u_char *)ip6) > maxlen) 2610 goto nolladdropt; 2611 2612 if (ln->la_flags & LLE_VALID) { 2613 nd_opt = (struct nd_opt_hdr *)p; 2614 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 2615 nd_opt->nd_opt_len = len >> 3; 2616 lladdr = (char *)(nd_opt + 1); 2617 bcopy(&ln->ll_addr, lladdr, ifp->if_addrlen); 2618 p += len; 2619 } 2620 } 2621 nolladdropt: 2622 if (ln != NULL) 2623 LLE_RUNLOCK(ln); 2624 2625 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2626 2627 /* just to be safe */ 2628 #ifdef M_DECRYPTED /*not openbsd*/ 2629 if (m0->m_flags & M_DECRYPTED) 2630 goto noredhdropt; 2631 #endif 2632 if (p - (u_char *)ip6 > maxlen) 2633 goto noredhdropt; 2634 2635 { 2636 /* redirected header option */ 2637 int len; 2638 struct nd_opt_rd_hdr *nd_opt_rh; 2639 2640 /* 2641 * compute the maximum size for icmp6 redirect header option. 2642 * XXX room for auth header? 2643 */ 2644 len = maxlen - (p - (u_char *)ip6); 2645 len &= ~7; 2646 2647 /* This is just for simplicity. */ 2648 if (m0->m_pkthdr.len != m0->m_len) { 2649 if (m0->m_next) { 2650 m_freem(m0->m_next); 2651 m0->m_next = NULL; 2652 } 2653 m0->m_pkthdr.len = m0->m_len; 2654 } 2655 2656 /* 2657 * Redirected header option spec (RFC2461 4.6.3) talks nothing 2658 * about padding/truncate rule for the original IP packet. 2659 * From the discussion on IPv6imp in Feb 1999, 2660 * the consensus was: 2661 * - "attach as much as possible" is the goal 2662 * - pad if not aligned (original size can be guessed by 2663 * original ip6 header) 2664 * Following code adds the padding if it is simple enough, 2665 * and truncates if not. 2666 */ 2667 if (m0->m_next || m0->m_pkthdr.len != m0->m_len) 2668 panic("assumption failed in %s:%d", __FILE__, 2669 __LINE__); 2670 2671 if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) { 2672 /* not enough room, truncate */ 2673 m0->m_pkthdr.len = m0->m_len = len - 2674 sizeof(*nd_opt_rh); 2675 } else { 2676 /* enough room, pad or truncate */ 2677 size_t extra; 2678 2679 extra = m0->m_pkthdr.len % 8; 2680 if (extra) { 2681 /* pad if easy enough, truncate if not */ 2682 if (8 - extra <= M_TRAILINGSPACE(m0)) { 2683 /* pad */ 2684 m0->m_len += (8 - extra); 2685 m0->m_pkthdr.len += (8 - extra); 2686 } else { 2687 /* truncate */ 2688 m0->m_pkthdr.len -= extra; 2689 m0->m_len -= extra; 2690 } 2691 } 2692 len = m0->m_pkthdr.len + sizeof(*nd_opt_rh); 2693 m0->m_pkthdr.len = m0->m_len = len - 2694 sizeof(*nd_opt_rh); 2695 } 2696 2697 nd_opt_rh = (struct nd_opt_rd_hdr *)p; 2698 bzero(nd_opt_rh, sizeof(*nd_opt_rh)); 2699 nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER; 2700 nd_opt_rh->nd_opt_rh_len = len >> 3; 2701 p += sizeof(*nd_opt_rh); 2702 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2703 2704 /* connect m0 to m */ 2705 m_tag_delete_chain(m0, NULL); 2706 m0->m_flags &= ~M_PKTHDR; 2707 m->m_next = m0; 2708 m->m_pkthdr.len = m->m_len + m0->m_len; 2709 m0 = NULL; 2710 } 2711 noredhdropt:; 2712 if (m0) { 2713 m_freem(m0); 2714 m0 = NULL; 2715 } 2716 2717 /* XXX: clear embedded link IDs in the inner header */ 2718 in6_clearscope(&sip6->ip6_src); 2719 in6_clearscope(&sip6->ip6_dst); 2720 in6_clearscope(&nd_rd->nd_rd_target); 2721 in6_clearscope(&nd_rd->nd_rd_dst); 2722 2723 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr)); 2724 2725 nd_rd->nd_rd_cksum = 0; 2726 nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2727 sizeof(*ip6), ntohs(ip6->ip6_plen)); 2728 2729 /* send the packet to outside... */ 2730 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2731 if (outif) { 2732 icmp6_ifstat_inc(outif, ifs6_out_msg); 2733 icmp6_ifstat_inc(outif, ifs6_out_redirect); 2734 } 2735 ICMP6STAT_INC(icp6s_outhist[ND_REDIRECT]); 2736 2737 return; 2738 2739 fail: 2740 if (m) 2741 m_freem(m); 2742 if (m0) 2743 m_freem(m0); 2744 } 2745 2746 /* 2747 * ICMPv6 socket option processing. 2748 */ 2749 int 2750 icmp6_ctloutput(struct socket *so, struct sockopt *sopt) 2751 { 2752 int error = 0; 2753 int optlen; 2754 struct inpcb *inp = sotoinpcb(so); 2755 int level, op, optname; 2756 2757 if (sopt) { 2758 level = sopt->sopt_level; 2759 op = sopt->sopt_dir; 2760 optname = sopt->sopt_name; 2761 optlen = sopt->sopt_valsize; 2762 } else 2763 level = op = optname = optlen = 0; 2764 2765 if (level != IPPROTO_ICMPV6) { 2766 return EINVAL; 2767 } 2768 2769 switch (op) { 2770 case PRCO_SETOPT: 2771 switch (optname) { 2772 case ICMP6_FILTER: 2773 { 2774 struct icmp6_filter ic6f; 2775 2776 if (optlen != sizeof(ic6f)) { 2777 error = EMSGSIZE; 2778 break; 2779 } 2780 error = sooptcopyin(sopt, &ic6f, optlen, optlen); 2781 if (error == 0) { 2782 INP_WLOCK(inp); 2783 *inp->in6p_icmp6filt = ic6f; 2784 INP_WUNLOCK(inp); 2785 } 2786 break; 2787 } 2788 2789 default: 2790 error = ENOPROTOOPT; 2791 break; 2792 } 2793 break; 2794 2795 case PRCO_GETOPT: 2796 switch (optname) { 2797 case ICMP6_FILTER: 2798 { 2799 struct icmp6_filter ic6f; 2800 2801 INP_RLOCK(inp); 2802 ic6f = *inp->in6p_icmp6filt; 2803 INP_RUNLOCK(inp); 2804 error = sooptcopyout(sopt, &ic6f, sizeof(ic6f)); 2805 break; 2806 } 2807 2808 default: 2809 error = ENOPROTOOPT; 2810 break; 2811 } 2812 break; 2813 } 2814 2815 return (error); 2816 } 2817 2818 /* 2819 * Perform rate limit check. 2820 * Returns 0 if it is okay to send the icmp6 packet. 2821 * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate 2822 * limitation. 2823 * 2824 * XXX per-destination/type check necessary? 2825 * 2826 * dst - not used at this moment 2827 * type - not used at this moment 2828 * code - not used at this moment 2829 */ 2830 static int 2831 icmp6_ratelimit(const struct in6_addr *dst, const int type, 2832 const int code) 2833 { 2834 int ret; 2835 2836 ret = 0; /* okay to send */ 2837 2838 /* PPS limit */ 2839 if (!ppsratecheck(&V_icmp6errppslim_last, &V_icmp6errpps_count, 2840 V_icmp6errppslim)) { 2841 /* The packet is subject to rate limit */ 2842 ret++; 2843 } 2844 2845 return ret; 2846 } 2847