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 /* 156 * Kernel module interface for updating icmp6stat. The argument is an index 157 * into icmp6stat treated as an array of u_quad_t. While this encodes the 158 * general layout of icmp6stat into the caller, it doesn't encode its 159 * location, so that future changes to add, for example, per-CPU stats 160 * support won't cause binary compatibility problems for kernel modules. 161 */ 162 void 163 kmod_icmp6stat_inc(int statnum) 164 { 165 166 (*((u_quad_t *)&V_icmp6stat + statnum))++; 167 } 168 169 static void 170 icmp6_errcount(struct icmp6errstat *stat, int type, int code) 171 { 172 switch (type) { 173 case ICMP6_DST_UNREACH: 174 switch (code) { 175 case ICMP6_DST_UNREACH_NOROUTE: 176 stat->icp6errs_dst_unreach_noroute++; 177 return; 178 case ICMP6_DST_UNREACH_ADMIN: 179 stat->icp6errs_dst_unreach_admin++; 180 return; 181 case ICMP6_DST_UNREACH_BEYONDSCOPE: 182 stat->icp6errs_dst_unreach_beyondscope++; 183 return; 184 case ICMP6_DST_UNREACH_ADDR: 185 stat->icp6errs_dst_unreach_addr++; 186 return; 187 case ICMP6_DST_UNREACH_NOPORT: 188 stat->icp6errs_dst_unreach_noport++; 189 return; 190 } 191 break; 192 case ICMP6_PACKET_TOO_BIG: 193 stat->icp6errs_packet_too_big++; 194 return; 195 case ICMP6_TIME_EXCEEDED: 196 switch (code) { 197 case ICMP6_TIME_EXCEED_TRANSIT: 198 stat->icp6errs_time_exceed_transit++; 199 return; 200 case ICMP6_TIME_EXCEED_REASSEMBLY: 201 stat->icp6errs_time_exceed_reassembly++; 202 return; 203 } 204 break; 205 case ICMP6_PARAM_PROB: 206 switch (code) { 207 case ICMP6_PARAMPROB_HEADER: 208 stat->icp6errs_paramprob_header++; 209 return; 210 case ICMP6_PARAMPROB_NEXTHEADER: 211 stat->icp6errs_paramprob_nextheader++; 212 return; 213 case ICMP6_PARAMPROB_OPTION: 214 stat->icp6errs_paramprob_option++; 215 return; 216 } 217 break; 218 case ND_REDIRECT: 219 stat->icp6errs_redirect++; 220 return; 221 } 222 stat->icp6errs_unknown++; 223 } 224 225 /* 226 * A wrapper function for icmp6_error() necessary when the erroneous packet 227 * may not contain enough scope zone information. 228 */ 229 void 230 icmp6_error2(struct mbuf *m, int type, int code, int param, 231 struct ifnet *ifp) 232 { 233 struct ip6_hdr *ip6; 234 235 if (ifp == NULL) 236 return; 237 238 #ifndef PULLDOWN_TEST 239 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), ); 240 #else 241 if (m->m_len < sizeof(struct ip6_hdr)) { 242 m = m_pullup(m, sizeof(struct ip6_hdr)); 243 if (m == NULL) 244 return; 245 } 246 #endif 247 248 ip6 = mtod(m, struct ip6_hdr *); 249 250 if (in6_setscope(&ip6->ip6_src, ifp, NULL) != 0) 251 return; 252 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0) 253 return; 254 255 icmp6_error(m, type, code, param); 256 } 257 258 /* 259 * Generate an error packet of type error in response to bad IP6 packet. 260 */ 261 void 262 icmp6_error(struct mbuf *m, int type, int code, int param) 263 { 264 struct ip6_hdr *oip6, *nip6; 265 struct icmp6_hdr *icmp6; 266 u_int preplen; 267 int off; 268 int nxt; 269 270 ICMP6STAT_INC(icp6s_error); 271 272 /* count per-type-code statistics */ 273 icmp6_errcount(&V_icmp6stat.icp6s_outerrhist, type, code); 274 275 #ifdef M_DECRYPTED /*not openbsd*/ 276 if (m->m_flags & M_DECRYPTED) { 277 ICMP6STAT_INC(icp6s_canterror); 278 goto freeit; 279 } 280 #endif 281 282 #ifndef PULLDOWN_TEST 283 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), ); 284 #else 285 if (m->m_len < sizeof(struct ip6_hdr)) { 286 m = m_pullup(m, sizeof(struct ip6_hdr)); 287 if (m == NULL) 288 return; 289 } 290 #endif 291 oip6 = mtod(m, struct ip6_hdr *); 292 293 /* 294 * If the destination address of the erroneous packet is a multicast 295 * address, or the packet was sent using link-layer multicast, 296 * we should basically suppress sending an error (RFC 2463, Section 297 * 2.4). 298 * We have two exceptions (the item e.2 in that section): 299 * - the Packet Too Big message can be sent for path MTU discovery. 300 * - the Parameter Problem Message that can be allowed an icmp6 error 301 * in the option type field. This check has been done in 302 * ip6_unknown_opt(), so we can just check the type and code. 303 */ 304 if ((m->m_flags & (M_BCAST|M_MCAST) || 305 IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) && 306 (type != ICMP6_PACKET_TOO_BIG && 307 (type != ICMP6_PARAM_PROB || 308 code != ICMP6_PARAMPROB_OPTION))) 309 goto freeit; 310 311 /* 312 * RFC 2463, 2.4 (e.5): source address check. 313 * XXX: the case of anycast source? 314 */ 315 if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) || 316 IN6_IS_ADDR_MULTICAST(&oip6->ip6_src)) 317 goto freeit; 318 319 /* 320 * If we are about to send ICMPv6 against ICMPv6 error/redirect, 321 * don't do it. 322 */ 323 nxt = -1; 324 off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt); 325 if (off >= 0 && nxt == IPPROTO_ICMPV6) { 326 struct icmp6_hdr *icp; 327 328 #ifndef PULLDOWN_TEST 329 IP6_EXTHDR_CHECK(m, 0, off + sizeof(struct icmp6_hdr), ); 330 icp = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 331 #else 332 IP6_EXTHDR_GET(icp, struct icmp6_hdr *, m, off, 333 sizeof(*icp)); 334 if (icp == NULL) { 335 ICMP6STAT_INC(icp6s_tooshort); 336 return; 337 } 338 #endif 339 if (icp->icmp6_type < ICMP6_ECHO_REQUEST || 340 icp->icmp6_type == ND_REDIRECT) { 341 /* 342 * ICMPv6 error 343 * Special case: for redirect (which is 344 * informational) we must not send icmp6 error. 345 */ 346 ICMP6STAT_INC(icp6s_canterror); 347 goto freeit; 348 } else { 349 /* ICMPv6 informational - send the error */ 350 } 351 } else { 352 /* non-ICMPv6 - send the error */ 353 } 354 355 oip6 = mtod(m, struct ip6_hdr *); /* adjust pointer */ 356 357 /* Finally, do rate limitation check. */ 358 if (icmp6_ratelimit(&oip6->ip6_src, type, code)) { 359 ICMP6STAT_INC(icp6s_toofreq); 360 goto freeit; 361 } 362 363 /* 364 * OK, ICMP6 can be generated. 365 */ 366 367 if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN) 368 m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len); 369 370 preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 371 M_PREPEND(m, preplen, M_DONTWAIT); 372 if (m && m->m_len < preplen) 373 m = m_pullup(m, preplen); 374 if (m == NULL) { 375 nd6log((LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__)); 376 return; 377 } 378 379 nip6 = mtod(m, struct ip6_hdr *); 380 nip6->ip6_src = oip6->ip6_src; 381 nip6->ip6_dst = oip6->ip6_dst; 382 383 in6_clearscope(&oip6->ip6_src); 384 in6_clearscope(&oip6->ip6_dst); 385 386 icmp6 = (struct icmp6_hdr *)(nip6 + 1); 387 icmp6->icmp6_type = type; 388 icmp6->icmp6_code = code; 389 icmp6->icmp6_pptr = htonl((u_int32_t)param); 390 391 /* 392 * icmp6_reflect() is designed to be in the input path. 393 * icmp6_error() can be called from both input and output path, 394 * and if we are in output path rcvif could contain bogus value. 395 * clear m->m_pkthdr.rcvif for safety, we should have enough scope 396 * information in ip header (nip6). 397 */ 398 m->m_pkthdr.rcvif = NULL; 399 400 ICMP6STAT_INC(icp6s_outhist[type]); 401 icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */ 402 403 return; 404 405 freeit: 406 /* 407 * If we can't tell whether or not we can generate ICMP6, free it. 408 */ 409 m_freem(m); 410 } 411 412 /* 413 * Process a received ICMP6 message. 414 */ 415 int 416 icmp6_input(struct mbuf **mp, int *offp, int proto) 417 { 418 struct mbuf *m = *mp, *n; 419 struct ifnet *ifp; 420 struct ip6_hdr *ip6, *nip6; 421 struct icmp6_hdr *icmp6, *nicmp6; 422 int off = *offp; 423 int icmp6len = m->m_pkthdr.len - *offp; 424 int code, sum, noff; 425 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 426 427 ifp = m->m_pkthdr.rcvif; 428 429 #ifndef PULLDOWN_TEST 430 IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_hdr), IPPROTO_DONE); 431 /* m might change if M_LOOP. So, call mtod after this */ 432 #endif 433 434 /* 435 * Locate icmp6 structure in mbuf, and check 436 * that not corrupted and of at least minimum length 437 */ 438 439 ip6 = mtod(m, struct ip6_hdr *); 440 if (icmp6len < sizeof(struct icmp6_hdr)) { 441 ICMP6STAT_INC(icp6s_tooshort); 442 goto freeit; 443 } 444 445 /* 446 * Check multicast group membership. 447 * Note: SSM filters are not applied for ICMPv6 traffic. 448 */ 449 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 450 struct in6_multi *inm; 451 452 inm = in6m_lookup(ifp, &ip6->ip6_dst); 453 if (inm == NULL) { 454 IP6STAT_INC(ip6s_notmember); 455 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 456 goto freeit; 457 } 458 } 459 460 /* 461 * calculate the checksum 462 */ 463 #ifndef PULLDOWN_TEST 464 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off); 465 #else 466 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6)); 467 if (icmp6 == NULL) { 468 ICMP6STAT_INC(icp6s_tooshort); 469 return IPPROTO_DONE; 470 } 471 #endif 472 code = icmp6->icmp6_code; 473 474 if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) { 475 nd6log((LOG_ERR, 476 "ICMP6 checksum error(%d|%x) %s\n", 477 icmp6->icmp6_type, sum, 478 ip6_sprintf(ip6bufs, &ip6->ip6_src))); 479 ICMP6STAT_INC(icp6s_checksum); 480 goto freeit; 481 } 482 483 if (faithprefix_p != NULL && (*faithprefix_p)(&ip6->ip6_dst)) { 484 /* 485 * Deliver very specific ICMP6 type only. 486 * This is important to deliver TOOBIG. Otherwise PMTUD 487 * will not work. 488 */ 489 switch (icmp6->icmp6_type) { 490 case ICMP6_DST_UNREACH: 491 case ICMP6_PACKET_TOO_BIG: 492 case ICMP6_TIME_EXCEEDED: 493 break; 494 default: 495 goto freeit; 496 } 497 } 498 499 ICMP6STAT_INC(icp6s_inhist[icmp6->icmp6_type]); 500 icmp6_ifstat_inc(ifp, ifs6_in_msg); 501 if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK) 502 icmp6_ifstat_inc(ifp, ifs6_in_error); 503 504 switch (icmp6->icmp6_type) { 505 case ICMP6_DST_UNREACH: 506 icmp6_ifstat_inc(ifp, ifs6_in_dstunreach); 507 switch (code) { 508 case ICMP6_DST_UNREACH_NOROUTE: 509 code = PRC_UNREACH_NET; 510 break; 511 case ICMP6_DST_UNREACH_ADMIN: 512 icmp6_ifstat_inc(ifp, ifs6_in_adminprohib); 513 code = PRC_UNREACH_PROTOCOL; /* is this a good code? */ 514 break; 515 case ICMP6_DST_UNREACH_ADDR: 516 code = PRC_HOSTDEAD; 517 break; 518 case ICMP6_DST_UNREACH_BEYONDSCOPE: 519 /* I mean "source address was incorrect." */ 520 code = PRC_PARAMPROB; 521 break; 522 case ICMP6_DST_UNREACH_NOPORT: 523 code = PRC_UNREACH_PORT; 524 break; 525 default: 526 goto badcode; 527 } 528 goto deliver; 529 break; 530 531 case ICMP6_PACKET_TOO_BIG: 532 icmp6_ifstat_inc(ifp, ifs6_in_pkttoobig); 533 534 /* validation is made in icmp6_mtudisc_update */ 535 536 code = PRC_MSGSIZE; 537 538 /* 539 * Updating the path MTU will be done after examining 540 * intermediate extension headers. 541 */ 542 goto deliver; 543 break; 544 545 case ICMP6_TIME_EXCEEDED: 546 icmp6_ifstat_inc(ifp, ifs6_in_timeexceed); 547 switch (code) { 548 case ICMP6_TIME_EXCEED_TRANSIT: 549 code = PRC_TIMXCEED_INTRANS; 550 break; 551 case ICMP6_TIME_EXCEED_REASSEMBLY: 552 code = PRC_TIMXCEED_REASS; 553 break; 554 default: 555 goto badcode; 556 } 557 goto deliver; 558 break; 559 560 case ICMP6_PARAM_PROB: 561 icmp6_ifstat_inc(ifp, ifs6_in_paramprob); 562 switch (code) { 563 case ICMP6_PARAMPROB_NEXTHEADER: 564 code = PRC_UNREACH_PROTOCOL; 565 break; 566 case ICMP6_PARAMPROB_HEADER: 567 case ICMP6_PARAMPROB_OPTION: 568 code = PRC_PARAMPROB; 569 break; 570 default: 571 goto badcode; 572 } 573 goto deliver; 574 break; 575 576 case ICMP6_ECHO_REQUEST: 577 icmp6_ifstat_inc(ifp, ifs6_in_echo); 578 if (code != 0) 579 goto badcode; 580 if ((n = m_copy(m, 0, M_COPYALL)) == NULL) { 581 /* Give up remote */ 582 break; 583 } 584 if ((n->m_flags & M_EXT) != 0 585 || n->m_len < off + sizeof(struct icmp6_hdr)) { 586 struct mbuf *n0 = n; 587 const int maxlen = sizeof(*nip6) + sizeof(*nicmp6); 588 int n0len; 589 590 MGETHDR(n, M_DONTWAIT, n0->m_type); 591 n0len = n0->m_pkthdr.len; /* save for use below */ 592 if (n) 593 M_MOVE_PKTHDR(n, n0); 594 if (n && maxlen >= MHLEN) { 595 MCLGET(n, M_DONTWAIT); 596 if ((n->m_flags & M_EXT) == 0) { 597 m_free(n); 598 n = NULL; 599 } 600 } 601 if (n == NULL) { 602 /* Give up remote */ 603 m_freem(n0); 604 break; 605 } 606 /* 607 * Copy IPv6 and ICMPv6 only. 608 */ 609 nip6 = mtod(n, struct ip6_hdr *); 610 bcopy(ip6, nip6, sizeof(struct ip6_hdr)); 611 nicmp6 = (struct icmp6_hdr *)(nip6 + 1); 612 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr)); 613 noff = sizeof(struct ip6_hdr); 614 /* new mbuf contains only ipv6+icmpv6 headers */ 615 n->m_len = noff + sizeof(struct icmp6_hdr); 616 /* 617 * Adjust mbuf. ip6_plen will be adjusted in 618 * ip6_output(). 619 */ 620 m_adj(n0, off + sizeof(struct icmp6_hdr)); 621 /* recalculate complete packet size */ 622 n->m_pkthdr.len = n0len + (noff - off); 623 n->m_next = n0; 624 } else { 625 nip6 = mtod(n, struct ip6_hdr *); 626 IP6_EXTHDR_GET(nicmp6, struct icmp6_hdr *, n, off, 627 sizeof(*nicmp6)); 628 noff = off; 629 } 630 nicmp6->icmp6_type = ICMP6_ECHO_REPLY; 631 nicmp6->icmp6_code = 0; 632 if (n) { 633 ICMP6STAT_INC(icp6s_reflect); 634 ICMP6STAT_INC(icp6s_outhist[ICMP6_ECHO_REPLY]); 635 icmp6_reflect(n, noff); 636 } 637 break; 638 639 case ICMP6_ECHO_REPLY: 640 icmp6_ifstat_inc(ifp, ifs6_in_echoreply); 641 if (code != 0) 642 goto badcode; 643 break; 644 645 case MLD_LISTENER_QUERY: 646 case MLD_LISTENER_REPORT: 647 case MLD_LISTENER_DONE: 648 case MLDV2_LISTENER_REPORT: 649 /* 650 * Drop MLD traffic which is not link-local, has a hop limit 651 * of greater than 1 hop, or which does not have the 652 * IPv6 HBH Router Alert option. 653 * As IPv6 HBH options are stripped in ip6_input() we must 654 * check an mbuf header flag. 655 * XXX Should we also sanity check that these messages 656 * were directed to a link-local multicast prefix? 657 */ 658 if ((ip6->ip6_hlim != 1) || (m->m_flags & M_RTALERT_MLD) == 0) 659 goto freeit; 660 if (mld_input(m, off, icmp6len) != 0) 661 return (IPPROTO_DONE); 662 /* m stays. */ 663 break; 664 665 case ICMP6_WRUREQUEST: /* ICMP6_FQDN_QUERY */ 666 { 667 enum { WRU, FQDN } mode; 668 669 if (!V_icmp6_nodeinfo) 670 break; 671 672 if (icmp6len == sizeof(struct icmp6_hdr) + 4) 673 mode = WRU; 674 else if (icmp6len >= sizeof(struct icmp6_nodeinfo)) 675 mode = FQDN; 676 else 677 goto badlen; 678 679 if (mode == FQDN) { 680 #ifndef PULLDOWN_TEST 681 IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_nodeinfo), 682 IPPROTO_DONE); 683 #endif 684 n = m_copy(m, 0, M_COPYALL); 685 if (n) 686 n = ni6_input(n, off); 687 /* XXX meaningless if n == NULL */ 688 noff = sizeof(struct ip6_hdr); 689 } else { 690 struct prison *pr; 691 u_char *p; 692 int maxlen, maxhlen, hlen; 693 694 /* 695 * XXX: this combination of flags is pointless, 696 * but should we keep this for compatibility? 697 */ 698 if ((V_icmp6_nodeinfo & 5) != 5) 699 break; 700 701 if (code != 0) 702 goto badcode; 703 maxlen = sizeof(*nip6) + sizeof(*nicmp6) + 4; 704 if (maxlen >= MCLBYTES) { 705 /* Give up remote */ 706 break; 707 } 708 MGETHDR(n, M_DONTWAIT, m->m_type); 709 if (n && maxlen > MHLEN) { 710 MCLGET(n, M_DONTWAIT); 711 if ((n->m_flags & M_EXT) == 0) { 712 m_free(n); 713 n = NULL; 714 } 715 } 716 if (n && !m_dup_pkthdr(n, m, M_DONTWAIT)) { 717 /* 718 * Previous code did a blind M_COPY_PKTHDR 719 * and said "just for rcvif". If true, then 720 * we could tolerate the dup failing (due to 721 * the deep copy of the tag chain). For now 722 * be conservative and just fail. 723 */ 724 m_free(n); 725 n = NULL; 726 } 727 if (n == NULL) { 728 /* Give up remote */ 729 break; 730 } 731 n->m_pkthdr.rcvif = NULL; 732 n->m_len = 0; 733 maxhlen = M_TRAILINGSPACE(n) - maxlen; 734 pr = curthread->td_ucred->cr_prison; 735 mtx_lock(&pr->pr_mtx); 736 hlen = strlen(pr->pr_hostname); 737 if (maxhlen > hlen) 738 maxhlen = hlen; 739 /* 740 * Copy IPv6 and ICMPv6 only. 741 */ 742 nip6 = mtod(n, struct ip6_hdr *); 743 bcopy(ip6, nip6, sizeof(struct ip6_hdr)); 744 nicmp6 = (struct icmp6_hdr *)(nip6 + 1); 745 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr)); 746 p = (u_char *)(nicmp6 + 1); 747 bzero(p, 4); 748 /* meaningless TTL */ 749 bcopy(pr->pr_hostname, p + 4, maxhlen); 750 mtx_unlock(&pr->pr_mtx); 751 noff = sizeof(struct ip6_hdr); 752 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + 753 sizeof(struct icmp6_hdr) + 4 + maxhlen; 754 nicmp6->icmp6_type = ICMP6_WRUREPLY; 755 nicmp6->icmp6_code = 0; 756 } 757 if (n) { 758 ICMP6STAT_INC(icp6s_reflect); 759 ICMP6STAT_INC(icp6s_outhist[ICMP6_WRUREPLY]); 760 icmp6_reflect(n, noff); 761 } 762 break; 763 } 764 765 case ICMP6_WRUREPLY: 766 if (code != 0) 767 goto badcode; 768 break; 769 770 case ND_ROUTER_SOLICIT: 771 icmp6_ifstat_inc(ifp, ifs6_in_routersolicit); 772 if (code != 0) 773 goto badcode; 774 if (icmp6len < sizeof(struct nd_router_solicit)) 775 goto badlen; 776 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 777 /* give up local */ 778 nd6_rs_input(m, off, icmp6len); 779 m = NULL; 780 goto freeit; 781 } 782 nd6_rs_input(n, off, icmp6len); 783 /* m stays. */ 784 break; 785 786 case ND_ROUTER_ADVERT: 787 icmp6_ifstat_inc(ifp, ifs6_in_routeradvert); 788 if (code != 0) 789 goto badcode; 790 if (icmp6len < sizeof(struct nd_router_advert)) 791 goto badlen; 792 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 793 /* give up local */ 794 nd6_ra_input(m, off, icmp6len); 795 m = NULL; 796 goto freeit; 797 } 798 nd6_ra_input(n, off, icmp6len); 799 /* m stays. */ 800 break; 801 802 case ND_NEIGHBOR_SOLICIT: 803 icmp6_ifstat_inc(ifp, ifs6_in_neighborsolicit); 804 if (code != 0) 805 goto badcode; 806 if (icmp6len < sizeof(struct nd_neighbor_solicit)) 807 goto badlen; 808 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 809 /* give up local */ 810 nd6_ns_input(m, off, icmp6len); 811 m = NULL; 812 goto freeit; 813 } 814 nd6_ns_input(n, off, icmp6len); 815 /* m stays. */ 816 break; 817 818 case ND_NEIGHBOR_ADVERT: 819 icmp6_ifstat_inc(ifp, ifs6_in_neighboradvert); 820 if (code != 0) 821 goto badcode; 822 if (icmp6len < sizeof(struct nd_neighbor_advert)) 823 goto badlen; 824 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 825 /* give up local */ 826 nd6_na_input(m, off, icmp6len); 827 m = NULL; 828 goto freeit; 829 } 830 nd6_na_input(n, off, icmp6len); 831 /* m stays. */ 832 break; 833 834 case ND_REDIRECT: 835 icmp6_ifstat_inc(ifp, ifs6_in_redirect); 836 if (code != 0) 837 goto badcode; 838 if (icmp6len < sizeof(struct nd_redirect)) 839 goto badlen; 840 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 841 /* give up local */ 842 icmp6_redirect_input(m, off); 843 m = NULL; 844 goto freeit; 845 } 846 icmp6_redirect_input(n, off); 847 /* m stays. */ 848 break; 849 850 case ICMP6_ROUTER_RENUMBERING: 851 if (code != ICMP6_ROUTER_RENUMBERING_COMMAND && 852 code != ICMP6_ROUTER_RENUMBERING_RESULT) 853 goto badcode; 854 if (icmp6len < sizeof(struct icmp6_router_renum)) 855 goto badlen; 856 break; 857 858 default: 859 nd6log((LOG_DEBUG, 860 "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n", 861 icmp6->icmp6_type, ip6_sprintf(ip6bufs, &ip6->ip6_src), 862 ip6_sprintf(ip6bufd, &ip6->ip6_dst), 863 ifp ? ifp->if_index : 0)); 864 if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) { 865 /* ICMPv6 error: MUST deliver it by spec... */ 866 code = PRC_NCMDS; 867 /* deliver */ 868 } else { 869 /* ICMPv6 informational: MUST not deliver */ 870 break; 871 } 872 deliver: 873 if (icmp6_notify_error(&m, off, icmp6len, code) != 0) { 874 /* In this case, m should've been freed. */ 875 return (IPPROTO_DONE); 876 } 877 break; 878 879 badcode: 880 ICMP6STAT_INC(icp6s_badcode); 881 break; 882 883 badlen: 884 ICMP6STAT_INC(icp6s_badlen); 885 break; 886 } 887 888 /* deliver the packet to appropriate sockets */ 889 icmp6_rip6_input(&m, *offp); 890 891 return IPPROTO_DONE; 892 893 freeit: 894 m_freem(m); 895 return IPPROTO_DONE; 896 } 897 898 static int 899 icmp6_notify_error(struct mbuf **mp, int off, int icmp6len, int code) 900 { 901 struct mbuf *m = *mp; 902 struct icmp6_hdr *icmp6; 903 struct ip6_hdr *eip6; 904 u_int32_t notifymtu; 905 struct sockaddr_in6 icmp6src, icmp6dst; 906 907 if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) { 908 ICMP6STAT_INC(icp6s_tooshort); 909 goto freeit; 910 } 911 #ifndef PULLDOWN_TEST 912 IP6_EXTHDR_CHECK(m, off, 913 sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr), -1); 914 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 915 #else 916 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, 917 sizeof(*icmp6) + sizeof(struct ip6_hdr)); 918 if (icmp6 == NULL) { 919 ICMP6STAT_INC(icp6s_tooshort); 920 return (-1); 921 } 922 #endif 923 eip6 = (struct ip6_hdr *)(icmp6 + 1); 924 925 /* Detect the upper level protocol */ 926 { 927 void (*ctlfunc)(int, struct sockaddr *, void *); 928 u_int8_t nxt = eip6->ip6_nxt; 929 int eoff = off + sizeof(struct icmp6_hdr) + 930 sizeof(struct ip6_hdr); 931 struct ip6ctlparam ip6cp; 932 struct in6_addr *finaldst = NULL; 933 int icmp6type = icmp6->icmp6_type; 934 struct ip6_frag *fh; 935 struct ip6_rthdr *rth; 936 struct ip6_rthdr0 *rth0; 937 int rthlen; 938 939 while (1) { /* XXX: should avoid infinite loop explicitly? */ 940 struct ip6_ext *eh; 941 942 switch (nxt) { 943 case IPPROTO_HOPOPTS: 944 case IPPROTO_DSTOPTS: 945 case IPPROTO_AH: 946 #ifndef PULLDOWN_TEST 947 IP6_EXTHDR_CHECK(m, 0, 948 eoff + sizeof(struct ip6_ext), -1); 949 eh = (struct ip6_ext *)(mtod(m, caddr_t) + eoff); 950 #else 951 IP6_EXTHDR_GET(eh, struct ip6_ext *, m, 952 eoff, sizeof(*eh)); 953 if (eh == NULL) { 954 ICMP6STAT_INC(icp6s_tooshort); 955 return (-1); 956 } 957 #endif 958 959 if (nxt == IPPROTO_AH) 960 eoff += (eh->ip6e_len + 2) << 2; 961 else 962 eoff += (eh->ip6e_len + 1) << 3; 963 nxt = eh->ip6e_nxt; 964 break; 965 case IPPROTO_ROUTING: 966 /* 967 * When the erroneous packet contains a 968 * routing header, we should examine the 969 * header to determine the final destination. 970 * Otherwise, we can't properly update 971 * information that depends on the final 972 * destination (e.g. path MTU). 973 */ 974 #ifndef PULLDOWN_TEST 975 IP6_EXTHDR_CHECK(m, 0, eoff + sizeof(*rth), -1); 976 rth = (struct ip6_rthdr *) 977 (mtod(m, caddr_t) + eoff); 978 #else 979 IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m, 980 eoff, sizeof(*rth)); 981 if (rth == NULL) { 982 ICMP6STAT_INC(icp6s_tooshort); 983 return (-1); 984 } 985 #endif 986 rthlen = (rth->ip6r_len + 1) << 3; 987 /* 988 * XXX: currently there is no 989 * officially defined type other 990 * than type-0. 991 * Note that if the segment left field 992 * is 0, all intermediate hops must 993 * have been passed. 994 */ 995 if (rth->ip6r_segleft && 996 rth->ip6r_type == IPV6_RTHDR_TYPE_0) { 997 int hops; 998 999 #ifndef PULLDOWN_TEST 1000 IP6_EXTHDR_CHECK(m, 0, eoff + rthlen, -1); 1001 rth0 = (struct ip6_rthdr0 *) 1002 (mtod(m, caddr_t) + eoff); 1003 #else 1004 IP6_EXTHDR_GET(rth0, 1005 struct ip6_rthdr0 *, m, 1006 eoff, rthlen); 1007 if (rth0 == NULL) { 1008 ICMP6STAT_INC(icp6s_tooshort); 1009 return (-1); 1010 } 1011 #endif 1012 /* just ignore a bogus header */ 1013 if ((rth0->ip6r0_len % 2) == 0 && 1014 (hops = rth0->ip6r0_len/2)) 1015 finaldst = (struct in6_addr *)(rth0 + 1) + (hops - 1); 1016 } 1017 eoff += rthlen; 1018 nxt = rth->ip6r_nxt; 1019 break; 1020 case IPPROTO_FRAGMENT: 1021 #ifndef PULLDOWN_TEST 1022 IP6_EXTHDR_CHECK(m, 0, eoff + 1023 sizeof(struct ip6_frag), -1); 1024 fh = (struct ip6_frag *)(mtod(m, caddr_t) + 1025 eoff); 1026 #else 1027 IP6_EXTHDR_GET(fh, struct ip6_frag *, m, 1028 eoff, sizeof(*fh)); 1029 if (fh == NULL) { 1030 ICMP6STAT_INC(icp6s_tooshort); 1031 return (-1); 1032 } 1033 #endif 1034 /* 1035 * Data after a fragment header is meaningless 1036 * unless it is the first fragment, but 1037 * we'll go to the notify label for path MTU 1038 * discovery. 1039 */ 1040 if (fh->ip6f_offlg & IP6F_OFF_MASK) 1041 goto notify; 1042 1043 eoff += sizeof(struct ip6_frag); 1044 nxt = fh->ip6f_nxt; 1045 break; 1046 default: 1047 /* 1048 * This case includes ESP and the No Next 1049 * Header. In such cases going to the notify 1050 * label does not have any meaning 1051 * (i.e. ctlfunc will be NULL), but we go 1052 * anyway since we might have to update 1053 * path MTU information. 1054 */ 1055 goto notify; 1056 } 1057 } 1058 notify: 1059 #ifndef PULLDOWN_TEST 1060 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 1061 #else 1062 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, 1063 sizeof(*icmp6) + sizeof(struct ip6_hdr)); 1064 if (icmp6 == NULL) { 1065 ICMP6STAT_INC(icp6s_tooshort); 1066 return (-1); 1067 } 1068 #endif 1069 1070 /* 1071 * retrieve parameters from the inner IPv6 header, and convert 1072 * them into sockaddr structures. 1073 * XXX: there is no guarantee that the source or destination 1074 * addresses of the inner packet are in the same scope as 1075 * the addresses of the icmp packet. But there is no other 1076 * way to determine the zone. 1077 */ 1078 eip6 = (struct ip6_hdr *)(icmp6 + 1); 1079 1080 bzero(&icmp6dst, sizeof(icmp6dst)); 1081 icmp6dst.sin6_len = sizeof(struct sockaddr_in6); 1082 icmp6dst.sin6_family = AF_INET6; 1083 if (finaldst == NULL) 1084 icmp6dst.sin6_addr = eip6->ip6_dst; 1085 else 1086 icmp6dst.sin6_addr = *finaldst; 1087 if (in6_setscope(&icmp6dst.sin6_addr, m->m_pkthdr.rcvif, NULL)) 1088 goto freeit; 1089 bzero(&icmp6src, sizeof(icmp6src)); 1090 icmp6src.sin6_len = sizeof(struct sockaddr_in6); 1091 icmp6src.sin6_family = AF_INET6; 1092 icmp6src.sin6_addr = eip6->ip6_src; 1093 if (in6_setscope(&icmp6src.sin6_addr, m->m_pkthdr.rcvif, NULL)) 1094 goto freeit; 1095 icmp6src.sin6_flowinfo = 1096 (eip6->ip6_flow & IPV6_FLOWLABEL_MASK); 1097 1098 if (finaldst == NULL) 1099 finaldst = &eip6->ip6_dst; 1100 ip6cp.ip6c_m = m; 1101 ip6cp.ip6c_icmp6 = icmp6; 1102 ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1); 1103 ip6cp.ip6c_off = eoff; 1104 ip6cp.ip6c_finaldst = finaldst; 1105 ip6cp.ip6c_src = &icmp6src; 1106 ip6cp.ip6c_nxt = nxt; 1107 1108 if (icmp6type == ICMP6_PACKET_TOO_BIG) { 1109 notifymtu = ntohl(icmp6->icmp6_mtu); 1110 ip6cp.ip6c_cmdarg = (void *)¬ifymtu; 1111 icmp6_mtudisc_update(&ip6cp, 1); /*XXX*/ 1112 } 1113 1114 ctlfunc = (void (*)(int, struct sockaddr *, void *)) 1115 (inet6sw[ip6_protox[nxt]].pr_ctlinput); 1116 if (ctlfunc) { 1117 (void) (*ctlfunc)(code, (struct sockaddr *)&icmp6dst, 1118 &ip6cp); 1119 } 1120 } 1121 *mp = m; 1122 return (0); 1123 1124 freeit: 1125 m_freem(m); 1126 return (-1); 1127 } 1128 1129 void 1130 icmp6_mtudisc_update(struct ip6ctlparam *ip6cp, int validated) 1131 { 1132 struct in6_addr *dst = ip6cp->ip6c_finaldst; 1133 struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6; 1134 struct mbuf *m = ip6cp->ip6c_m; /* will be necessary for scope issue */ 1135 u_int mtu = ntohl(icmp6->icmp6_mtu); 1136 struct in_conninfo inc; 1137 1138 #if 0 1139 /* 1140 * RFC2460 section 5, last paragraph. 1141 * even though minimum link MTU for IPv6 is IPV6_MMTU, 1142 * we may see ICMPv6 too big with mtu < IPV6_MMTU 1143 * due to packet translator in the middle. 1144 * see ip6_output() and ip6_getpmtu() "alwaysfrag" case for 1145 * special handling. 1146 */ 1147 if (mtu < IPV6_MMTU) 1148 return; 1149 #endif 1150 1151 /* 1152 * we reject ICMPv6 too big with abnormally small value. 1153 * XXX what is the good definition of "abnormally small"? 1154 */ 1155 if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8) 1156 return; 1157 1158 if (!validated) 1159 return; 1160 1161 /* 1162 * In case the suggested mtu is less than IPV6_MMTU, we 1163 * only need to remember that it was for above mentioned 1164 * "alwaysfrag" case. 1165 * Try to be as close to the spec as possible. 1166 */ 1167 if (mtu < IPV6_MMTU) 1168 mtu = IPV6_MMTU - 8; 1169 1170 bzero(&inc, sizeof(inc)); 1171 inc.inc_flags |= INC_ISIPV6; 1172 inc.inc6_faddr = *dst; 1173 if (in6_setscope(&inc.inc6_faddr, m->m_pkthdr.rcvif, NULL)) 1174 return; 1175 1176 if (mtu < tcp_maxmtu6(&inc, NULL)) { 1177 tcp_hc_updatemtu(&inc, mtu); 1178 ICMP6STAT_INC(icp6s_pmtuchg); 1179 } 1180 } 1181 1182 /* 1183 * Process a Node Information Query packet, based on 1184 * draft-ietf-ipngwg-icmp-name-lookups-07. 1185 * 1186 * Spec incompatibilities: 1187 * - IPv6 Subject address handling 1188 * - IPv4 Subject address handling support missing 1189 * - Proxy reply (answer even if it's not for me) 1190 * - joins NI group address at in6_ifattach() time only, does not cope 1191 * with hostname changes by sethostname(3) 1192 */ 1193 static struct mbuf * 1194 ni6_input(struct mbuf *m, int off) 1195 { 1196 struct icmp6_nodeinfo *ni6, *nni6; 1197 struct mbuf *n = NULL; 1198 struct prison *pr; 1199 u_int16_t qtype; 1200 int subjlen; 1201 int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); 1202 struct ni_reply_fqdn *fqdn; 1203 int addrs; /* for NI_QTYPE_NODEADDR */ 1204 struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */ 1205 struct in6_addr in6_subj; /* subject address */ 1206 struct ip6_hdr *ip6; 1207 int oldfqdn = 0; /* if 1, return pascal string (03 draft) */ 1208 char *subj = NULL; 1209 struct in6_ifaddr *ia6 = NULL; 1210 1211 ip6 = mtod(m, struct ip6_hdr *); 1212 #ifndef PULLDOWN_TEST 1213 ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off); 1214 #else 1215 IP6_EXTHDR_GET(ni6, struct icmp6_nodeinfo *, m, off, sizeof(*ni6)); 1216 if (ni6 == NULL) { 1217 /* m is already reclaimed */ 1218 return (NULL); 1219 } 1220 #endif 1221 1222 /* 1223 * Validate IPv6 source address. 1224 * The default configuration MUST be to refuse answering queries from 1225 * global-scope addresses according to RFC4602. 1226 * Notes: 1227 * - it's not very clear what "refuse" means; this implementation 1228 * simply drops it. 1229 * - it's not very easy to identify global-scope (unicast) addresses 1230 * since there are many prefixes for them. It should be safer 1231 * and in practice sufficient to check "all" but loopback and 1232 * link-local (note that site-local unicast was deprecated and 1233 * ULA is defined as global scope-wise) 1234 */ 1235 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_GLOBALOK) == 0 && 1236 !IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) && 1237 !IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) 1238 goto bad; 1239 1240 /* 1241 * Validate IPv6 destination address. 1242 * 1243 * The Responder must discard the Query without further processing 1244 * unless it is one of the Responder's unicast or anycast addresses, or 1245 * a link-local scope multicast address which the Responder has joined. 1246 * [RFC4602, Section 5.] 1247 */ 1248 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 1249 if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst)) 1250 goto bad; 1251 /* else it's a link-local multicast, fine */ 1252 } else { /* unicast or anycast */ 1253 if ((ia6 = ip6_getdstifaddr(m)) == NULL) 1254 goto bad; /* XXX impossible */ 1255 1256 if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) && 1257 !(V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK)) { 1258 ifa_free(&ia6->ia_ifa); 1259 nd6log((LOG_DEBUG, "ni6_input: ignore node info to " 1260 "a temporary address in %s:%d", 1261 __FILE__, __LINE__)); 1262 goto bad; 1263 } 1264 ifa_free(&ia6->ia_ifa); 1265 } 1266 1267 /* validate query Subject field. */ 1268 qtype = ntohs(ni6->ni_qtype); 1269 subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo); 1270 switch (qtype) { 1271 case NI_QTYPE_NOOP: 1272 case NI_QTYPE_SUPTYPES: 1273 /* 07 draft */ 1274 if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0) 1275 break; 1276 /* FALLTHROUGH */ 1277 case NI_QTYPE_FQDN: 1278 case NI_QTYPE_NODEADDR: 1279 case NI_QTYPE_IPV4ADDR: 1280 switch (ni6->ni_code) { 1281 case ICMP6_NI_SUBJ_IPV6: 1282 #if ICMP6_NI_SUBJ_IPV6 != 0 1283 case 0: 1284 #endif 1285 /* 1286 * backward compatibility - try to accept 03 draft 1287 * format, where no Subject is present. 1288 */ 1289 if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 && 1290 subjlen == 0) { 1291 oldfqdn++; 1292 break; 1293 } 1294 #if ICMP6_NI_SUBJ_IPV6 != 0 1295 if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6) 1296 goto bad; 1297 #endif 1298 1299 if (subjlen != sizeof(struct in6_addr)) 1300 goto bad; 1301 1302 /* 1303 * Validate Subject address. 1304 * 1305 * Not sure what exactly "address belongs to the node" 1306 * means in the spec, is it just unicast, or what? 1307 * 1308 * At this moment we consider Subject address as 1309 * "belong to the node" if the Subject address equals 1310 * to the IPv6 destination address; validation for 1311 * IPv6 destination address should have done enough 1312 * check for us. 1313 * 1314 * We do not do proxy at this moment. 1315 */ 1316 /* m_pulldown instead of copy? */ 1317 m_copydata(m, off + sizeof(struct icmp6_nodeinfo), 1318 subjlen, (caddr_t)&in6_subj); 1319 if (in6_setscope(&in6_subj, m->m_pkthdr.rcvif, NULL)) 1320 goto bad; 1321 1322 subj = (char *)&in6_subj; 1323 if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &in6_subj)) 1324 break; 1325 1326 /* 1327 * XXX if we are to allow other cases, we should really 1328 * be careful about scope here. 1329 * basically, we should disallow queries toward IPv6 1330 * destination X with subject Y, 1331 * if scope(X) > scope(Y). 1332 * if we allow scope(X) > scope(Y), it will result in 1333 * information leakage across scope boundary. 1334 */ 1335 goto bad; 1336 1337 case ICMP6_NI_SUBJ_FQDN: 1338 /* 1339 * Validate Subject name with gethostname(3). 1340 * 1341 * The behavior may need some debate, since: 1342 * - we are not sure if the node has FQDN as 1343 * hostname (returned by gethostname(3)). 1344 * - the code does wildcard match for truncated names. 1345 * however, we are not sure if we want to perform 1346 * wildcard match, if gethostname(3) side has 1347 * truncated hostname. 1348 */ 1349 pr = curthread->td_ucred->cr_prison; 1350 mtx_lock(&pr->pr_mtx); 1351 n = ni6_nametodns(pr->pr_hostname, 1352 strlen(pr->pr_hostname), 0); 1353 mtx_unlock(&pr->pr_mtx); 1354 if (!n || n->m_next || n->m_len == 0) 1355 goto bad; 1356 IP6_EXTHDR_GET(subj, char *, m, 1357 off + sizeof(struct icmp6_nodeinfo), subjlen); 1358 if (subj == NULL) 1359 goto bad; 1360 if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *), 1361 n->m_len)) { 1362 goto bad; 1363 } 1364 m_freem(n); 1365 n = NULL; 1366 break; 1367 1368 case ICMP6_NI_SUBJ_IPV4: /* XXX: to be implemented? */ 1369 default: 1370 goto bad; 1371 } 1372 break; 1373 } 1374 1375 /* refuse based on configuration. XXX ICMP6_NI_REFUSED? */ 1376 switch (qtype) { 1377 case NI_QTYPE_FQDN: 1378 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_FQDNOK) == 0) 1379 goto bad; 1380 break; 1381 case NI_QTYPE_NODEADDR: 1382 case NI_QTYPE_IPV4ADDR: 1383 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_NODEADDROK) == 0) 1384 goto bad; 1385 break; 1386 } 1387 1388 /* guess reply length */ 1389 switch (qtype) { 1390 case NI_QTYPE_NOOP: 1391 break; /* no reply data */ 1392 case NI_QTYPE_SUPTYPES: 1393 replylen += sizeof(u_int32_t); 1394 break; 1395 case NI_QTYPE_FQDN: 1396 /* XXX will append an mbuf */ 1397 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); 1398 break; 1399 case NI_QTYPE_NODEADDR: 1400 addrs = ni6_addrs(ni6, m, &ifp, (struct in6_addr *)subj); 1401 if ((replylen += addrs * (sizeof(struct in6_addr) + 1402 sizeof(u_int32_t))) > MCLBYTES) 1403 replylen = MCLBYTES; /* XXX: will truncate pkt later */ 1404 break; 1405 case NI_QTYPE_IPV4ADDR: 1406 /* unsupported - should respond with unknown Qtype? */ 1407 break; 1408 default: 1409 /* 1410 * XXX: We must return a reply with the ICMP6 code 1411 * `unknown Qtype' in this case. However we regard the case 1412 * as an FQDN query for backward compatibility. 1413 * Older versions set a random value to this field, 1414 * so it rarely varies in the defined qtypes. 1415 * But the mechanism is not reliable... 1416 * maybe we should obsolete older versions. 1417 */ 1418 qtype = NI_QTYPE_FQDN; 1419 /* XXX will append an mbuf */ 1420 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); 1421 oldfqdn++; 1422 break; 1423 } 1424 1425 /* allocate an mbuf to reply. */ 1426 MGETHDR(n, M_DONTWAIT, m->m_type); 1427 if (n == NULL) { 1428 m_freem(m); 1429 return (NULL); 1430 } 1431 M_MOVE_PKTHDR(n, m); /* just for recvif */ 1432 if (replylen > MHLEN) { 1433 if (replylen > MCLBYTES) { 1434 /* 1435 * XXX: should we try to allocate more? But MCLBYTES 1436 * is probably much larger than IPV6_MMTU... 1437 */ 1438 goto bad; 1439 } 1440 MCLGET(n, M_DONTWAIT); 1441 if ((n->m_flags & M_EXT) == 0) { 1442 goto bad; 1443 } 1444 } 1445 n->m_pkthdr.len = n->m_len = replylen; 1446 1447 /* copy mbuf header and IPv6 + Node Information base headers */ 1448 bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr)); 1449 nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1); 1450 bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo)); 1451 1452 /* qtype dependent procedure */ 1453 switch (qtype) { 1454 case NI_QTYPE_NOOP: 1455 nni6->ni_code = ICMP6_NI_SUCCESS; 1456 nni6->ni_flags = 0; 1457 break; 1458 case NI_QTYPE_SUPTYPES: 1459 { 1460 u_int32_t v; 1461 nni6->ni_code = ICMP6_NI_SUCCESS; 1462 nni6->ni_flags = htons(0x0000); /* raw bitmap */ 1463 /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */ 1464 v = (u_int32_t)htonl(0x0000000f); 1465 bcopy(&v, nni6 + 1, sizeof(u_int32_t)); 1466 break; 1467 } 1468 case NI_QTYPE_FQDN: 1469 nni6->ni_code = ICMP6_NI_SUCCESS; 1470 fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) + 1471 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo)); 1472 nni6->ni_flags = 0; /* XXX: meaningless TTL */ 1473 fqdn->ni_fqdn_ttl = 0; /* ditto. */ 1474 /* 1475 * XXX do we really have FQDN in hostname? 1476 */ 1477 pr = curthread->td_ucred->cr_prison; 1478 mtx_lock(&pr->pr_mtx); 1479 n->m_next = ni6_nametodns(pr->pr_hostname, 1480 strlen(pr->pr_hostname), oldfqdn); 1481 mtx_unlock(&pr->pr_mtx); 1482 if (n->m_next == NULL) 1483 goto bad; 1484 /* XXX we assume that n->m_next is not a chain */ 1485 if (n->m_next->m_next != NULL) 1486 goto bad; 1487 n->m_pkthdr.len += n->m_next->m_len; 1488 break; 1489 case NI_QTYPE_NODEADDR: 1490 { 1491 int lenlim, copied; 1492 1493 nni6->ni_code = ICMP6_NI_SUCCESS; 1494 n->m_pkthdr.len = n->m_len = 1495 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); 1496 lenlim = M_TRAILINGSPACE(n); 1497 copied = ni6_store_addrs(ni6, nni6, ifp, lenlim); 1498 /* XXX: reset mbuf length */ 1499 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + 1500 sizeof(struct icmp6_nodeinfo) + copied; 1501 break; 1502 } 1503 default: 1504 break; /* XXX impossible! */ 1505 } 1506 1507 nni6->ni_type = ICMP6_NI_REPLY; 1508 m_freem(m); 1509 return (n); 1510 1511 bad: 1512 m_freem(m); 1513 if (n) 1514 m_freem(n); 1515 return (NULL); 1516 } 1517 1518 /* 1519 * make a mbuf with DNS-encoded string. no compression support. 1520 * 1521 * XXX names with less than 2 dots (like "foo" or "foo.section") will be 1522 * treated as truncated name (two \0 at the end). this is a wild guess. 1523 * 1524 * old - return pascal string if non-zero 1525 */ 1526 static struct mbuf * 1527 ni6_nametodns(const char *name, int namelen, int old) 1528 { 1529 struct mbuf *m; 1530 char *cp, *ep; 1531 const char *p, *q; 1532 int i, len, nterm; 1533 1534 if (old) 1535 len = namelen + 1; 1536 else 1537 len = MCLBYTES; 1538 1539 /* because MAXHOSTNAMELEN is usually 256, we use cluster mbuf */ 1540 MGET(m, M_DONTWAIT, MT_DATA); 1541 if (m && len > MLEN) { 1542 MCLGET(m, M_DONTWAIT); 1543 if ((m->m_flags & M_EXT) == 0) 1544 goto fail; 1545 } 1546 if (!m) 1547 goto fail; 1548 m->m_next = NULL; 1549 1550 if (old) { 1551 m->m_len = len; 1552 *mtod(m, char *) = namelen; 1553 bcopy(name, mtod(m, char *) + 1, namelen); 1554 return m; 1555 } else { 1556 m->m_len = 0; 1557 cp = mtod(m, char *); 1558 ep = mtod(m, char *) + M_TRAILINGSPACE(m); 1559 1560 /* if not certain about my name, return empty buffer */ 1561 if (namelen == 0) 1562 return m; 1563 1564 /* 1565 * guess if it looks like shortened hostname, or FQDN. 1566 * shortened hostname needs two trailing "\0". 1567 */ 1568 i = 0; 1569 for (p = name; p < name + namelen; p++) { 1570 if (*p && *p == '.') 1571 i++; 1572 } 1573 if (i < 2) 1574 nterm = 2; 1575 else 1576 nterm = 1; 1577 1578 p = name; 1579 while (cp < ep && p < name + namelen) { 1580 i = 0; 1581 for (q = p; q < name + namelen && *q && *q != '.'; q++) 1582 i++; 1583 /* result does not fit into mbuf */ 1584 if (cp + i + 1 >= ep) 1585 goto fail; 1586 /* 1587 * DNS label length restriction, RFC1035 page 8. 1588 * "i == 0" case is included here to avoid returning 1589 * 0-length label on "foo..bar". 1590 */ 1591 if (i <= 0 || i >= 64) 1592 goto fail; 1593 *cp++ = i; 1594 bcopy(p, cp, i); 1595 cp += i; 1596 p = q; 1597 if (p < name + namelen && *p == '.') 1598 p++; 1599 } 1600 /* termination */ 1601 if (cp + nterm >= ep) 1602 goto fail; 1603 while (nterm-- > 0) 1604 *cp++ = '\0'; 1605 m->m_len = cp - mtod(m, char *); 1606 return m; 1607 } 1608 1609 panic("should not reach here"); 1610 /* NOTREACHED */ 1611 1612 fail: 1613 if (m) 1614 m_freem(m); 1615 return NULL; 1616 } 1617 1618 /* 1619 * check if two DNS-encoded string matches. takes care of truncated 1620 * form (with \0\0 at the end). no compression support. 1621 * XXX upper/lowercase match (see RFC2065) 1622 */ 1623 static int 1624 ni6_dnsmatch(const char *a, int alen, const char *b, int blen) 1625 { 1626 const char *a0, *b0; 1627 int l; 1628 1629 /* simplest case - need validation? */ 1630 if (alen == blen && bcmp(a, b, alen) == 0) 1631 return 1; 1632 1633 a0 = a; 1634 b0 = b; 1635 1636 /* termination is mandatory */ 1637 if (alen < 2 || blen < 2) 1638 return 0; 1639 if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0') 1640 return 0; 1641 alen--; 1642 blen--; 1643 1644 while (a - a0 < alen && b - b0 < blen) { 1645 if (a - a0 + 1 > alen || b - b0 + 1 > blen) 1646 return 0; 1647 1648 if ((signed char)a[0] < 0 || (signed char)b[0] < 0) 1649 return 0; 1650 /* we don't support compression yet */ 1651 if (a[0] >= 64 || b[0] >= 64) 1652 return 0; 1653 1654 /* truncated case */ 1655 if (a[0] == 0 && a - a0 == alen - 1) 1656 return 1; 1657 if (b[0] == 0 && b - b0 == blen - 1) 1658 return 1; 1659 if (a[0] == 0 || b[0] == 0) 1660 return 0; 1661 1662 if (a[0] != b[0]) 1663 return 0; 1664 l = a[0]; 1665 if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen) 1666 return 0; 1667 if (bcmp(a + 1, b + 1, l) != 0) 1668 return 0; 1669 1670 a += 1 + l; 1671 b += 1 + l; 1672 } 1673 1674 if (a - a0 == alen && b - b0 == blen) 1675 return 1; 1676 else 1677 return 0; 1678 } 1679 1680 /* 1681 * calculate the number of addresses to be returned in the node info reply. 1682 */ 1683 static int 1684 ni6_addrs(struct icmp6_nodeinfo *ni6, struct mbuf *m, struct ifnet **ifpp, 1685 struct in6_addr *subj) 1686 { 1687 struct ifnet *ifp; 1688 struct in6_ifaddr *ifa6; 1689 struct ifaddr *ifa; 1690 int addrs = 0, addrsofif, iffound = 0; 1691 int niflags = ni6->ni_flags; 1692 1693 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) { 1694 switch (ni6->ni_code) { 1695 case ICMP6_NI_SUBJ_IPV6: 1696 if (subj == NULL) /* must be impossible... */ 1697 return (0); 1698 break; 1699 default: 1700 /* 1701 * XXX: we only support IPv6 subject address for 1702 * this Qtype. 1703 */ 1704 return (0); 1705 } 1706 } 1707 1708 IFNET_RLOCK_NOSLEEP(); 1709 for (ifp = TAILQ_FIRST(&V_ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list)) { 1710 addrsofif = 0; 1711 IF_ADDR_LOCK(ifp); 1712 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 1713 if (ifa->ifa_addr->sa_family != AF_INET6) 1714 continue; 1715 ifa6 = (struct in6_ifaddr *)ifa; 1716 1717 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 && 1718 IN6_ARE_ADDR_EQUAL(subj, &ifa6->ia_addr.sin6_addr)) 1719 iffound = 1; 1720 1721 /* 1722 * IPv4-mapped addresses can only be returned by a 1723 * Node Information proxy, since they represent 1724 * addresses of IPv4-only nodes, which perforce do 1725 * not implement this protocol. 1726 * [icmp-name-lookups-07, Section 5.4] 1727 * So we don't support NI_NODEADDR_FLAG_COMPAT in 1728 * this function at this moment. 1729 */ 1730 1731 /* What do we have to do about ::1? */ 1732 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { 1733 case IPV6_ADDR_SCOPE_LINKLOCAL: 1734 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) 1735 continue; 1736 break; 1737 case IPV6_ADDR_SCOPE_SITELOCAL: 1738 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) 1739 continue; 1740 break; 1741 case IPV6_ADDR_SCOPE_GLOBAL: 1742 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) 1743 continue; 1744 break; 1745 default: 1746 continue; 1747 } 1748 1749 /* 1750 * check if anycast is okay. 1751 * XXX: just experimental. not in the spec. 1752 */ 1753 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && 1754 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) 1755 continue; /* we need only unicast addresses */ 1756 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && 1757 (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) { 1758 continue; 1759 } 1760 addrsofif++; /* count the address */ 1761 } 1762 IF_ADDR_UNLOCK(ifp); 1763 if (iffound) { 1764 *ifpp = ifp; 1765 IFNET_RUNLOCK_NOSLEEP(); 1766 return (addrsofif); 1767 } 1768 1769 addrs += addrsofif; 1770 } 1771 IFNET_RUNLOCK_NOSLEEP(); 1772 1773 return (addrs); 1774 } 1775 1776 static int 1777 ni6_store_addrs(struct icmp6_nodeinfo *ni6, struct icmp6_nodeinfo *nni6, 1778 struct ifnet *ifp0, int resid) 1779 { 1780 struct ifnet *ifp = ifp0 ? ifp0 : TAILQ_FIRST(&V_ifnet); 1781 struct in6_ifaddr *ifa6; 1782 struct ifaddr *ifa; 1783 struct ifnet *ifp_dep = NULL; 1784 int copied = 0, allow_deprecated = 0; 1785 u_char *cp = (u_char *)(nni6 + 1); 1786 int niflags = ni6->ni_flags; 1787 u_int32_t ltime; 1788 1789 if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL)) 1790 return (0); /* needless to copy */ 1791 1792 IFNET_RLOCK_NOSLEEP(); 1793 again: 1794 1795 for (; ifp; ifp = TAILQ_NEXT(ifp, if_list)) { 1796 IF_ADDR_LOCK(ifp); 1797 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 1798 if (ifa->ifa_addr->sa_family != AF_INET6) 1799 continue; 1800 ifa6 = (struct in6_ifaddr *)ifa; 1801 1802 if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 && 1803 allow_deprecated == 0) { 1804 /* 1805 * prefererred address should be put before 1806 * deprecated addresses. 1807 */ 1808 1809 /* record the interface for later search */ 1810 if (ifp_dep == NULL) 1811 ifp_dep = ifp; 1812 1813 continue; 1814 } else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 && 1815 allow_deprecated != 0) 1816 continue; /* we now collect deprecated addrs */ 1817 1818 /* What do we have to do about ::1? */ 1819 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { 1820 case IPV6_ADDR_SCOPE_LINKLOCAL: 1821 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) 1822 continue; 1823 break; 1824 case IPV6_ADDR_SCOPE_SITELOCAL: 1825 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) 1826 continue; 1827 break; 1828 case IPV6_ADDR_SCOPE_GLOBAL: 1829 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) 1830 continue; 1831 break; 1832 default: 1833 continue; 1834 } 1835 1836 /* 1837 * check if anycast is okay. 1838 * XXX: just experimental. not in the spec. 1839 */ 1840 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && 1841 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) 1842 continue; 1843 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && 1844 (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) { 1845 continue; 1846 } 1847 1848 /* now we can copy the address */ 1849 if (resid < sizeof(struct in6_addr) + 1850 sizeof(u_int32_t)) { 1851 IF_ADDR_UNLOCK(ifp); 1852 /* 1853 * We give up much more copy. 1854 * Set the truncate flag and return. 1855 */ 1856 nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE; 1857 IFNET_RUNLOCK_NOSLEEP(); 1858 return (copied); 1859 } 1860 1861 /* 1862 * Set the TTL of the address. 1863 * The TTL value should be one of the following 1864 * according to the specification: 1865 * 1866 * 1. The remaining lifetime of a DHCP lease on the 1867 * address, or 1868 * 2. The remaining Valid Lifetime of a prefix from 1869 * which the address was derived through Stateless 1870 * Autoconfiguration. 1871 * 1872 * Note that we currently do not support stateful 1873 * address configuration by DHCPv6, so the former 1874 * case can't happen. 1875 */ 1876 if (ifa6->ia6_lifetime.ia6t_expire == 0) 1877 ltime = ND6_INFINITE_LIFETIME; 1878 else { 1879 if (ifa6->ia6_lifetime.ia6t_expire > 1880 time_second) 1881 ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_second); 1882 else 1883 ltime = 0; 1884 } 1885 1886 bcopy(<ime, cp, sizeof(u_int32_t)); 1887 cp += sizeof(u_int32_t); 1888 1889 /* copy the address itself */ 1890 bcopy(&ifa6->ia_addr.sin6_addr, cp, 1891 sizeof(struct in6_addr)); 1892 in6_clearscope((struct in6_addr *)cp); /* XXX */ 1893 cp += sizeof(struct in6_addr); 1894 1895 resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t)); 1896 copied += (sizeof(struct in6_addr) + sizeof(u_int32_t)); 1897 } 1898 IF_ADDR_UNLOCK(ifp); 1899 if (ifp0) /* we need search only on the specified IF */ 1900 break; 1901 } 1902 1903 if (allow_deprecated == 0 && ifp_dep != NULL) { 1904 ifp = ifp_dep; 1905 allow_deprecated = 1; 1906 1907 goto again; 1908 } 1909 1910 IFNET_RUNLOCK_NOSLEEP(); 1911 1912 return (copied); 1913 } 1914 1915 /* 1916 * XXX almost dup'ed code with rip6_input. 1917 */ 1918 static int 1919 icmp6_rip6_input(struct mbuf **mp, int off) 1920 { 1921 struct mbuf *m = *mp; 1922 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1923 struct inpcb *in6p; 1924 struct inpcb *last = NULL; 1925 struct sockaddr_in6 fromsa; 1926 struct icmp6_hdr *icmp6; 1927 struct mbuf *opts = NULL; 1928 1929 #ifndef PULLDOWN_TEST 1930 /* this is assumed to be safe. */ 1931 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off); 1932 #else 1933 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6)); 1934 if (icmp6 == NULL) { 1935 /* m is already reclaimed */ 1936 return (IPPROTO_DONE); 1937 } 1938 #endif 1939 1940 /* 1941 * XXX: the address may have embedded scope zone ID, which should be 1942 * hidden from applications. 1943 */ 1944 bzero(&fromsa, sizeof(fromsa)); 1945 fromsa.sin6_family = AF_INET6; 1946 fromsa.sin6_len = sizeof(struct sockaddr_in6); 1947 fromsa.sin6_addr = ip6->ip6_src; 1948 if (sa6_recoverscope(&fromsa)) { 1949 m_freem(m); 1950 return (IPPROTO_DONE); 1951 } 1952 1953 INP_INFO_RLOCK(&V_ripcbinfo); 1954 LIST_FOREACH(in6p, &V_ripcb, inp_list) { 1955 if ((in6p->inp_vflag & INP_IPV6) == 0) 1956 continue; 1957 if (in6p->inp_ip_p != IPPROTO_ICMPV6) 1958 continue; 1959 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) && 1960 !IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &ip6->ip6_dst)) 1961 continue; 1962 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr) && 1963 !IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src)) 1964 continue; 1965 INP_RLOCK(in6p); 1966 if (ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type, 1967 in6p->in6p_icmp6filt)) { 1968 INP_RUNLOCK(in6p); 1969 continue; 1970 } 1971 if (last != NULL) { 1972 struct mbuf *n = NULL; 1973 1974 /* 1975 * Recent network drivers tend to allocate a single 1976 * mbuf cluster, rather than to make a couple of 1977 * mbufs without clusters. Also, since the IPv6 code 1978 * path tries to avoid m_pullup(), it is highly 1979 * probable that we still have an mbuf cluster here 1980 * even though the necessary length can be stored in an 1981 * mbuf's internal buffer. 1982 * Meanwhile, the default size of the receive socket 1983 * buffer for raw sockets is not so large. This means 1984 * the possibility of packet loss is relatively higher 1985 * than before. To avoid this scenario, we copy the 1986 * received data to a separate mbuf that does not use 1987 * a cluster, if possible. 1988 * XXX: it is better to copy the data after stripping 1989 * intermediate headers. 1990 */ 1991 if ((m->m_flags & M_EXT) && m->m_next == NULL && 1992 m->m_len <= MHLEN) { 1993 MGET(n, M_DONTWAIT, m->m_type); 1994 if (n != NULL) { 1995 if (m_dup_pkthdr(n, m, M_NOWAIT)) { 1996 bcopy(m->m_data, n->m_data, 1997 m->m_len); 1998 n->m_len = m->m_len; 1999 } else { 2000 m_free(n); 2001 n = NULL; 2002 } 2003 } 2004 } 2005 if (n != NULL || 2006 (n = m_copy(m, 0, (int)M_COPYALL)) != NULL) { 2007 if (last->inp_flags & INP_CONTROLOPTS) 2008 ip6_savecontrol(last, n, &opts); 2009 /* strip intermediate headers */ 2010 m_adj(n, off); 2011 SOCKBUF_LOCK(&last->inp_socket->so_rcv); 2012 if (sbappendaddr_locked( 2013 &last->inp_socket->so_rcv, 2014 (struct sockaddr *)&fromsa, n, opts) 2015 == 0) { 2016 /* should notify about lost packet */ 2017 m_freem(n); 2018 if (opts) { 2019 m_freem(opts); 2020 } 2021 SOCKBUF_UNLOCK( 2022 &last->inp_socket->so_rcv); 2023 } else 2024 sorwakeup_locked(last->inp_socket); 2025 opts = NULL; 2026 } 2027 INP_RUNLOCK(last); 2028 } 2029 last = in6p; 2030 } 2031 INP_INFO_RUNLOCK(&V_ripcbinfo); 2032 if (last != NULL) { 2033 if (last->inp_flags & INP_CONTROLOPTS) 2034 ip6_savecontrol(last, m, &opts); 2035 /* strip intermediate headers */ 2036 m_adj(m, off); 2037 2038 /* avoid using mbuf clusters if possible (see above) */ 2039 if ((m->m_flags & M_EXT) && m->m_next == NULL && 2040 m->m_len <= MHLEN) { 2041 struct mbuf *n; 2042 2043 MGET(n, M_DONTWAIT, m->m_type); 2044 if (n != NULL) { 2045 if (m_dup_pkthdr(n, m, M_NOWAIT)) { 2046 bcopy(m->m_data, n->m_data, m->m_len); 2047 n->m_len = m->m_len; 2048 2049 m_freem(m); 2050 m = n; 2051 } else { 2052 m_freem(n); 2053 n = NULL; 2054 } 2055 } 2056 } 2057 SOCKBUF_LOCK(&last->inp_socket->so_rcv); 2058 if (sbappendaddr_locked(&last->inp_socket->so_rcv, 2059 (struct sockaddr *)&fromsa, m, opts) == 0) { 2060 m_freem(m); 2061 if (opts) 2062 m_freem(opts); 2063 SOCKBUF_UNLOCK(&last->inp_socket->so_rcv); 2064 } else 2065 sorwakeup_locked(last->inp_socket); 2066 INP_RUNLOCK(last); 2067 } else { 2068 m_freem(m); 2069 IP6STAT_DEC(ip6s_delivered); 2070 } 2071 return IPPROTO_DONE; 2072 } 2073 2074 /* 2075 * Reflect the ip6 packet back to the source. 2076 * OFF points to the icmp6 header, counted from the top of the mbuf. 2077 */ 2078 void 2079 icmp6_reflect(struct mbuf *m, size_t off) 2080 { 2081 struct ip6_hdr *ip6; 2082 struct icmp6_hdr *icmp6; 2083 struct in6_ifaddr *ia = NULL; 2084 int plen; 2085 int type, code; 2086 struct ifnet *outif = NULL; 2087 struct in6_addr origdst, src, *srcp = NULL; 2088 2089 /* too short to reflect */ 2090 if (off < sizeof(struct ip6_hdr)) { 2091 nd6log((LOG_DEBUG, 2092 "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n", 2093 (u_long)off, (u_long)sizeof(struct ip6_hdr), 2094 __FILE__, __LINE__)); 2095 goto bad; 2096 } 2097 2098 /* 2099 * If there are extra headers between IPv6 and ICMPv6, strip 2100 * off that header first. 2101 */ 2102 #ifdef DIAGNOSTIC 2103 if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN) 2104 panic("assumption failed in icmp6_reflect"); 2105 #endif 2106 if (off > sizeof(struct ip6_hdr)) { 2107 size_t l; 2108 struct ip6_hdr nip6; 2109 2110 l = off - sizeof(struct ip6_hdr); 2111 m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6); 2112 m_adj(m, l); 2113 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 2114 if (m->m_len < l) { 2115 if ((m = m_pullup(m, l)) == NULL) 2116 return; 2117 } 2118 bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6)); 2119 } else /* off == sizeof(struct ip6_hdr) */ { 2120 size_t l; 2121 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 2122 if (m->m_len < l) { 2123 if ((m = m_pullup(m, l)) == NULL) 2124 return; 2125 } 2126 } 2127 plen = m->m_pkthdr.len - sizeof(struct ip6_hdr); 2128 ip6 = mtod(m, struct ip6_hdr *); 2129 ip6->ip6_nxt = IPPROTO_ICMPV6; 2130 icmp6 = (struct icmp6_hdr *)(ip6 + 1); 2131 type = icmp6->icmp6_type; /* keep type for statistics */ 2132 code = icmp6->icmp6_code; /* ditto. */ 2133 2134 origdst = ip6->ip6_dst; 2135 /* 2136 * ip6_input() drops a packet if its src is multicast. 2137 * So, the src is never multicast. 2138 */ 2139 ip6->ip6_dst = ip6->ip6_src; 2140 2141 /* 2142 * If the incoming packet was addressed directly to us (i.e. unicast), 2143 * use dst as the src for the reply. 2144 * The IN6_IFF_NOTREADY case should be VERY rare, but is possible 2145 * (for example) when we encounter an error while forwarding procedure 2146 * destined to a duplicated address of ours. 2147 * Note that ip6_getdstifaddr() may fail if we are in an error handling 2148 * procedure of an outgoing packet of our own, in which case we need 2149 * to search in the ifaddr list. 2150 */ 2151 if (!IN6_IS_ADDR_MULTICAST(&origdst)) { 2152 if ((ia = ip6_getdstifaddr(m))) { 2153 if (!(ia->ia6_flags & 2154 (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) 2155 srcp = &ia->ia_addr.sin6_addr; 2156 } else { 2157 struct sockaddr_in6 d; 2158 2159 bzero(&d, sizeof(d)); 2160 d.sin6_family = AF_INET6; 2161 d.sin6_len = sizeof(d); 2162 d.sin6_addr = origdst; 2163 ia = (struct in6_ifaddr *) 2164 ifa_ifwithaddr((struct sockaddr *)&d); 2165 if (ia && 2166 !(ia->ia6_flags & 2167 (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) { 2168 srcp = &ia->ia_addr.sin6_addr; 2169 } 2170 } 2171 } 2172 2173 if ((srcp != NULL) && 2174 (in6_addrscope(srcp) != in6_addrscope(&ip6->ip6_src))) 2175 srcp = NULL; 2176 2177 if (srcp == NULL) { 2178 int e; 2179 struct sockaddr_in6 sin6; 2180 struct route_in6 ro; 2181 2182 /* 2183 * This case matches to multicasts, our anycast, or unicasts 2184 * that we do not own. Select a source address based on the 2185 * source address of the erroneous packet. 2186 */ 2187 bzero(&sin6, sizeof(sin6)); 2188 sin6.sin6_family = AF_INET6; 2189 sin6.sin6_len = sizeof(sin6); 2190 sin6.sin6_addr = ip6->ip6_dst; /* zone ID should be embedded */ 2191 2192 bzero(&ro, sizeof(ro)); 2193 e = in6_selectsrc(&sin6, NULL, NULL, &ro, NULL, &outif, &src); 2194 if (ro.ro_rt) 2195 RTFREE(ro.ro_rt); /* XXX: we could use this */ 2196 if (e) { 2197 char ip6buf[INET6_ADDRSTRLEN]; 2198 nd6log((LOG_DEBUG, 2199 "icmp6_reflect: source can't be determined: " 2200 "dst=%s, error=%d\n", 2201 ip6_sprintf(ip6buf, &sin6.sin6_addr), e)); 2202 goto bad; 2203 } 2204 srcp = &src; 2205 } 2206 2207 ip6->ip6_src = *srcp; 2208 ip6->ip6_flow = 0; 2209 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2210 ip6->ip6_vfc |= IPV6_VERSION; 2211 ip6->ip6_nxt = IPPROTO_ICMPV6; 2212 if (outif) 2213 ip6->ip6_hlim = ND_IFINFO(outif)->chlim; 2214 else if (m->m_pkthdr.rcvif) { 2215 /* XXX: This may not be the outgoing interface */ 2216 ip6->ip6_hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim; 2217 } else 2218 ip6->ip6_hlim = V_ip6_defhlim; 2219 2220 icmp6->icmp6_cksum = 0; 2221 icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2222 sizeof(struct ip6_hdr), plen); 2223 2224 /* 2225 * XXX option handling 2226 */ 2227 2228 m->m_flags &= ~(M_BCAST|M_MCAST); 2229 2230 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2231 if (outif) 2232 icmp6_ifoutstat_inc(outif, type, code); 2233 2234 if (ia != NULL) 2235 ifa_free(&ia->ia_ifa); 2236 return; 2237 2238 bad: 2239 if (ia != NULL) 2240 ifa_free(&ia->ia_ifa); 2241 m_freem(m); 2242 return; 2243 } 2244 2245 void 2246 icmp6_fasttimo(void) 2247 { 2248 2249 mld_fasttimo(); 2250 } 2251 2252 void 2253 icmp6_slowtimo(void) 2254 { 2255 2256 mld_slowtimo(); 2257 } 2258 2259 static const char * 2260 icmp6_redirect_diag(struct in6_addr *src6, struct in6_addr *dst6, 2261 struct in6_addr *tgt6) 2262 { 2263 static char buf[1024]; 2264 char ip6bufs[INET6_ADDRSTRLEN]; 2265 char ip6bufd[INET6_ADDRSTRLEN]; 2266 char ip6buft[INET6_ADDRSTRLEN]; 2267 snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)", 2268 ip6_sprintf(ip6bufs, src6), ip6_sprintf(ip6bufd, dst6), 2269 ip6_sprintf(ip6buft, tgt6)); 2270 return buf; 2271 } 2272 2273 void 2274 icmp6_redirect_input(struct mbuf *m, int off) 2275 { 2276 struct ifnet *ifp; 2277 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 2278 struct nd_redirect *nd_rd; 2279 int icmp6len = ntohs(ip6->ip6_plen); 2280 char *lladdr = NULL; 2281 int lladdrlen = 0; 2282 u_char *redirhdr = NULL; 2283 int redirhdrlen = 0; 2284 struct rtentry *rt = NULL; 2285 int is_router; 2286 int is_onlink; 2287 struct in6_addr src6 = ip6->ip6_src; 2288 struct in6_addr redtgt6; 2289 struct in6_addr reddst6; 2290 union nd_opts ndopts; 2291 char ip6buf[INET6_ADDRSTRLEN]; 2292 2293 if (!m) 2294 return; 2295 2296 ifp = m->m_pkthdr.rcvif; 2297 2298 if (!ifp) 2299 return; 2300 2301 /* XXX if we are router, we don't update route by icmp6 redirect */ 2302 if (V_ip6_forwarding) 2303 goto freeit; 2304 if (!V_icmp6_rediraccept) 2305 goto freeit; 2306 2307 #ifndef PULLDOWN_TEST 2308 IP6_EXTHDR_CHECK(m, off, icmp6len,); 2309 nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off); 2310 #else 2311 IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len); 2312 if (nd_rd == NULL) { 2313 ICMP6STAT_INC(icp6s_tooshort); 2314 return; 2315 } 2316 #endif 2317 redtgt6 = nd_rd->nd_rd_target; 2318 reddst6 = nd_rd->nd_rd_dst; 2319 2320 if (in6_setscope(&redtgt6, m->m_pkthdr.rcvif, NULL) || 2321 in6_setscope(&reddst6, m->m_pkthdr.rcvif, NULL)) { 2322 goto freeit; 2323 } 2324 2325 /* validation */ 2326 if (!IN6_IS_ADDR_LINKLOCAL(&src6)) { 2327 nd6log((LOG_ERR, 2328 "ICMP6 redirect sent from %s rejected; " 2329 "must be from linklocal\n", 2330 ip6_sprintf(ip6buf, &src6))); 2331 goto bad; 2332 } 2333 if (ip6->ip6_hlim != 255) { 2334 nd6log((LOG_ERR, 2335 "ICMP6 redirect sent from %s rejected; " 2336 "hlim=%d (must be 255)\n", 2337 ip6_sprintf(ip6buf, &src6), ip6->ip6_hlim)); 2338 goto bad; 2339 } 2340 { 2341 /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */ 2342 struct sockaddr_in6 sin6; 2343 struct in6_addr *gw6; 2344 2345 bzero(&sin6, sizeof(sin6)); 2346 sin6.sin6_family = AF_INET6; 2347 sin6.sin6_len = sizeof(struct sockaddr_in6); 2348 bcopy(&reddst6, &sin6.sin6_addr, sizeof(reddst6)); 2349 rt = rtalloc1((struct sockaddr *)&sin6, 0, 0UL); 2350 if (rt) { 2351 if (rt->rt_gateway == NULL || 2352 rt->rt_gateway->sa_family != AF_INET6) { 2353 nd6log((LOG_ERR, 2354 "ICMP6 redirect rejected; no route " 2355 "with inet6 gateway found for redirect dst: %s\n", 2356 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2357 RTFREE_LOCKED(rt); 2358 goto bad; 2359 } 2360 2361 gw6 = &(((struct sockaddr_in6 *)rt->rt_gateway)->sin6_addr); 2362 if (bcmp(&src6, gw6, sizeof(struct in6_addr)) != 0) { 2363 nd6log((LOG_ERR, 2364 "ICMP6 redirect rejected; " 2365 "not equal to gw-for-src=%s (must be same): " 2366 "%s\n", 2367 ip6_sprintf(ip6buf, gw6), 2368 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2369 RTFREE_LOCKED(rt); 2370 goto bad; 2371 } 2372 } else { 2373 nd6log((LOG_ERR, 2374 "ICMP6 redirect rejected; " 2375 "no route found for redirect dst: %s\n", 2376 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2377 goto bad; 2378 } 2379 RTFREE_LOCKED(rt); 2380 rt = NULL; 2381 } 2382 if (IN6_IS_ADDR_MULTICAST(&reddst6)) { 2383 nd6log((LOG_ERR, 2384 "ICMP6 redirect rejected; " 2385 "redirect dst must be unicast: %s\n", 2386 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2387 goto bad; 2388 } 2389 2390 is_router = is_onlink = 0; 2391 if (IN6_IS_ADDR_LINKLOCAL(&redtgt6)) 2392 is_router = 1; /* router case */ 2393 if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0) 2394 is_onlink = 1; /* on-link destination case */ 2395 if (!is_router && !is_onlink) { 2396 nd6log((LOG_ERR, 2397 "ICMP6 redirect rejected; " 2398 "neither router case nor onlink case: %s\n", 2399 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2400 goto bad; 2401 } 2402 /* validation passed */ 2403 2404 icmp6len -= sizeof(*nd_rd); 2405 nd6_option_init(nd_rd + 1, icmp6len, &ndopts); 2406 if (nd6_options(&ndopts) < 0) { 2407 nd6log((LOG_INFO, "icmp6_redirect_input: " 2408 "invalid ND option, rejected: %s\n", 2409 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2410 /* nd6_options have incremented stats */ 2411 goto freeit; 2412 } 2413 2414 if (ndopts.nd_opts_tgt_lladdr) { 2415 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 2416 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 2417 } 2418 2419 if (ndopts.nd_opts_rh) { 2420 redirhdrlen = ndopts.nd_opts_rh->nd_opt_rh_len; 2421 redirhdr = (u_char *)(ndopts.nd_opts_rh + 1); /* xxx */ 2422 } 2423 2424 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 2425 nd6log((LOG_INFO, 2426 "icmp6_redirect_input: lladdrlen mismatch for %s " 2427 "(if %d, icmp6 packet %d): %s\n", 2428 ip6_sprintf(ip6buf, &redtgt6), 2429 ifp->if_addrlen, lladdrlen - 2, 2430 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2431 goto bad; 2432 } 2433 2434 /* RFC 2461 8.3 */ 2435 nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT, 2436 is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER); 2437 2438 if (!is_onlink) { /* better router case. perform rtredirect. */ 2439 /* perform rtredirect */ 2440 struct sockaddr_in6 sdst; 2441 struct sockaddr_in6 sgw; 2442 struct sockaddr_in6 ssrc; 2443 2444 bzero(&sdst, sizeof(sdst)); 2445 bzero(&sgw, sizeof(sgw)); 2446 bzero(&ssrc, sizeof(ssrc)); 2447 sdst.sin6_family = sgw.sin6_family = ssrc.sin6_family = AF_INET6; 2448 sdst.sin6_len = sgw.sin6_len = ssrc.sin6_len = 2449 sizeof(struct sockaddr_in6); 2450 bcopy(&redtgt6, &sgw.sin6_addr, sizeof(struct in6_addr)); 2451 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr)); 2452 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr)); 2453 rtredirect((struct sockaddr *)&sdst, (struct sockaddr *)&sgw, 2454 (struct sockaddr *)NULL, RTF_GATEWAY | RTF_HOST, 2455 (struct sockaddr *)&ssrc); 2456 } 2457 /* finally update cached route in each socket via pfctlinput */ 2458 { 2459 struct sockaddr_in6 sdst; 2460 2461 bzero(&sdst, sizeof(sdst)); 2462 sdst.sin6_family = AF_INET6; 2463 sdst.sin6_len = sizeof(struct sockaddr_in6); 2464 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr)); 2465 pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst); 2466 #ifdef IPSEC 2467 key_sa_routechange((struct sockaddr *)&sdst); 2468 #endif /* IPSEC */ 2469 } 2470 2471 freeit: 2472 m_freem(m); 2473 return; 2474 2475 bad: 2476 ICMP6STAT_INC(icp6s_badredirect); 2477 m_freem(m); 2478 } 2479 2480 void 2481 icmp6_redirect_output(struct mbuf *m0, struct rtentry *rt) 2482 { 2483 struct ifnet *ifp; /* my outgoing interface */ 2484 struct in6_addr *ifp_ll6; 2485 struct in6_addr *router_ll6; 2486 struct ip6_hdr *sip6; /* m0 as struct ip6_hdr */ 2487 struct mbuf *m = NULL; /* newly allocated one */ 2488 struct ip6_hdr *ip6; /* m as struct ip6_hdr */ 2489 struct nd_redirect *nd_rd; 2490 struct llentry *ln = NULL; 2491 size_t maxlen; 2492 u_char *p; 2493 struct ifnet *outif = NULL; 2494 struct sockaddr_in6 src_sa; 2495 2496 icmp6_errcount(&V_icmp6stat.icp6s_outerrhist, ND_REDIRECT, 0); 2497 2498 /* if we are not router, we don't send icmp6 redirect */ 2499 if (!V_ip6_forwarding) 2500 goto fail; 2501 2502 /* sanity check */ 2503 if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp)) 2504 goto fail; 2505 2506 /* 2507 * Address check: 2508 * the source address must identify a neighbor, and 2509 * the destination address must not be a multicast address 2510 * [RFC 2461, sec 8.2] 2511 */ 2512 sip6 = mtod(m0, struct ip6_hdr *); 2513 bzero(&src_sa, sizeof(src_sa)); 2514 src_sa.sin6_family = AF_INET6; 2515 src_sa.sin6_len = sizeof(src_sa); 2516 src_sa.sin6_addr = sip6->ip6_src; 2517 if (nd6_is_addr_neighbor(&src_sa, ifp) == 0) 2518 goto fail; 2519 if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst)) 2520 goto fail; /* what should we do here? */ 2521 2522 /* rate limit */ 2523 if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0)) 2524 goto fail; 2525 2526 /* 2527 * Since we are going to append up to 1280 bytes (= IPV6_MMTU), 2528 * we almost always ask for an mbuf cluster for simplicity. 2529 * (MHLEN < IPV6_MMTU is almost always true) 2530 */ 2531 #if IPV6_MMTU >= MCLBYTES 2532 # error assumption failed about IPV6_MMTU and MCLBYTES 2533 #endif 2534 MGETHDR(m, M_DONTWAIT, MT_HEADER); 2535 if (m && IPV6_MMTU >= MHLEN) 2536 MCLGET(m, M_DONTWAIT); 2537 if (!m) 2538 goto fail; 2539 m->m_pkthdr.rcvif = NULL; 2540 m->m_len = 0; 2541 maxlen = M_TRAILINGSPACE(m); 2542 maxlen = min(IPV6_MMTU, maxlen); 2543 /* just for safety */ 2544 if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) + 2545 ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) { 2546 goto fail; 2547 } 2548 2549 { 2550 /* get ip6 linklocal address for ifp(my outgoing interface). */ 2551 struct in6_ifaddr *ia; 2552 if ((ia = in6ifa_ifpforlinklocal(ifp, 2553 IN6_IFF_NOTREADY| 2554 IN6_IFF_ANYCAST)) == NULL) 2555 goto fail; 2556 ifp_ll6 = &ia->ia_addr.sin6_addr; 2557 /* XXXRW: reference released prematurely. */ 2558 ifa_free(&ia->ia_ifa); 2559 } 2560 2561 /* get ip6 linklocal address for the router. */ 2562 if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) { 2563 struct sockaddr_in6 *sin6; 2564 sin6 = (struct sockaddr_in6 *)rt->rt_gateway; 2565 router_ll6 = &sin6->sin6_addr; 2566 if (!IN6_IS_ADDR_LINKLOCAL(router_ll6)) 2567 router_ll6 = (struct in6_addr *)NULL; 2568 } else 2569 router_ll6 = (struct in6_addr *)NULL; 2570 2571 /* ip6 */ 2572 ip6 = mtod(m, struct ip6_hdr *); 2573 ip6->ip6_flow = 0; 2574 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2575 ip6->ip6_vfc |= IPV6_VERSION; 2576 /* ip6->ip6_plen will be set later */ 2577 ip6->ip6_nxt = IPPROTO_ICMPV6; 2578 ip6->ip6_hlim = 255; 2579 /* ip6->ip6_src must be linklocal addr for my outgoing if. */ 2580 bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr)); 2581 bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr)); 2582 2583 /* ND Redirect */ 2584 nd_rd = (struct nd_redirect *)(ip6 + 1); 2585 nd_rd->nd_rd_type = ND_REDIRECT; 2586 nd_rd->nd_rd_code = 0; 2587 nd_rd->nd_rd_reserved = 0; 2588 if (rt->rt_flags & RTF_GATEWAY) { 2589 /* 2590 * nd_rd->nd_rd_target must be a link-local address in 2591 * better router cases. 2592 */ 2593 if (!router_ll6) 2594 goto fail; 2595 bcopy(router_ll6, &nd_rd->nd_rd_target, 2596 sizeof(nd_rd->nd_rd_target)); 2597 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2598 sizeof(nd_rd->nd_rd_dst)); 2599 } else { 2600 /* make sure redtgt == reddst */ 2601 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target, 2602 sizeof(nd_rd->nd_rd_target)); 2603 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2604 sizeof(nd_rd->nd_rd_dst)); 2605 } 2606 2607 p = (u_char *)(nd_rd + 1); 2608 2609 if (!router_ll6) 2610 goto nolladdropt; 2611 2612 { 2613 /* target lladdr option */ 2614 int len; 2615 struct nd_opt_hdr *nd_opt; 2616 char *lladdr; 2617 2618 IF_AFDATA_LOCK(ifp); 2619 ln = nd6_lookup(router_ll6, 0, ifp); 2620 IF_AFDATA_UNLOCK(ifp); 2621 if (ln == NULL) 2622 goto nolladdropt; 2623 2624 len = sizeof(*nd_opt) + ifp->if_addrlen; 2625 len = (len + 7) & ~7; /* round by 8 */ 2626 /* safety check */ 2627 if (len + (p - (u_char *)ip6) > maxlen) 2628 goto nolladdropt; 2629 2630 if (ln->la_flags & LLE_VALID) { 2631 nd_opt = (struct nd_opt_hdr *)p; 2632 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 2633 nd_opt->nd_opt_len = len >> 3; 2634 lladdr = (char *)(nd_opt + 1); 2635 bcopy(&ln->ll_addr, lladdr, ifp->if_addrlen); 2636 p += len; 2637 } 2638 } 2639 nolladdropt: 2640 if (ln != NULL) 2641 LLE_RUNLOCK(ln); 2642 2643 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2644 2645 /* just to be safe */ 2646 #ifdef M_DECRYPTED /*not openbsd*/ 2647 if (m0->m_flags & M_DECRYPTED) 2648 goto noredhdropt; 2649 #endif 2650 if (p - (u_char *)ip6 > maxlen) 2651 goto noredhdropt; 2652 2653 { 2654 /* redirected header option */ 2655 int len; 2656 struct nd_opt_rd_hdr *nd_opt_rh; 2657 2658 /* 2659 * compute the maximum size for icmp6 redirect header option. 2660 * XXX room for auth header? 2661 */ 2662 len = maxlen - (p - (u_char *)ip6); 2663 len &= ~7; 2664 2665 /* This is just for simplicity. */ 2666 if (m0->m_pkthdr.len != m0->m_len) { 2667 if (m0->m_next) { 2668 m_freem(m0->m_next); 2669 m0->m_next = NULL; 2670 } 2671 m0->m_pkthdr.len = m0->m_len; 2672 } 2673 2674 /* 2675 * Redirected header option spec (RFC2461 4.6.3) talks nothing 2676 * about padding/truncate rule for the original IP packet. 2677 * From the discussion on IPv6imp in Feb 1999, 2678 * the consensus was: 2679 * - "attach as much as possible" is the goal 2680 * - pad if not aligned (original size can be guessed by 2681 * original ip6 header) 2682 * Following code adds the padding if it is simple enough, 2683 * and truncates if not. 2684 */ 2685 if (m0->m_next || m0->m_pkthdr.len != m0->m_len) 2686 panic("assumption failed in %s:%d", __FILE__, 2687 __LINE__); 2688 2689 if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) { 2690 /* not enough room, truncate */ 2691 m0->m_pkthdr.len = m0->m_len = len - 2692 sizeof(*nd_opt_rh); 2693 } else { 2694 /* enough room, pad or truncate */ 2695 size_t extra; 2696 2697 extra = m0->m_pkthdr.len % 8; 2698 if (extra) { 2699 /* pad if easy enough, truncate if not */ 2700 if (8 - extra <= M_TRAILINGSPACE(m0)) { 2701 /* pad */ 2702 m0->m_len += (8 - extra); 2703 m0->m_pkthdr.len += (8 - extra); 2704 } else { 2705 /* truncate */ 2706 m0->m_pkthdr.len -= extra; 2707 m0->m_len -= extra; 2708 } 2709 } 2710 len = m0->m_pkthdr.len + sizeof(*nd_opt_rh); 2711 m0->m_pkthdr.len = m0->m_len = len - 2712 sizeof(*nd_opt_rh); 2713 } 2714 2715 nd_opt_rh = (struct nd_opt_rd_hdr *)p; 2716 bzero(nd_opt_rh, sizeof(*nd_opt_rh)); 2717 nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER; 2718 nd_opt_rh->nd_opt_rh_len = len >> 3; 2719 p += sizeof(*nd_opt_rh); 2720 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2721 2722 /* connect m0 to m */ 2723 m_tag_delete_chain(m0, NULL); 2724 m0->m_flags &= ~M_PKTHDR; 2725 m->m_next = m0; 2726 m->m_pkthdr.len = m->m_len + m0->m_len; 2727 m0 = NULL; 2728 } 2729 noredhdropt:; 2730 if (m0) { 2731 m_freem(m0); 2732 m0 = NULL; 2733 } 2734 2735 /* XXX: clear embedded link IDs in the inner header */ 2736 in6_clearscope(&sip6->ip6_src); 2737 in6_clearscope(&sip6->ip6_dst); 2738 in6_clearscope(&nd_rd->nd_rd_target); 2739 in6_clearscope(&nd_rd->nd_rd_dst); 2740 2741 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr)); 2742 2743 nd_rd->nd_rd_cksum = 0; 2744 nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2745 sizeof(*ip6), ntohs(ip6->ip6_plen)); 2746 2747 /* send the packet to outside... */ 2748 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2749 if (outif) { 2750 icmp6_ifstat_inc(outif, ifs6_out_msg); 2751 icmp6_ifstat_inc(outif, ifs6_out_redirect); 2752 } 2753 ICMP6STAT_INC(icp6s_outhist[ND_REDIRECT]); 2754 2755 return; 2756 2757 fail: 2758 if (m) 2759 m_freem(m); 2760 if (m0) 2761 m_freem(m0); 2762 } 2763 2764 /* 2765 * ICMPv6 socket option processing. 2766 */ 2767 int 2768 icmp6_ctloutput(struct socket *so, struct sockopt *sopt) 2769 { 2770 int error = 0; 2771 int optlen; 2772 struct inpcb *inp = sotoinpcb(so); 2773 int level, op, optname; 2774 2775 if (sopt) { 2776 level = sopt->sopt_level; 2777 op = sopt->sopt_dir; 2778 optname = sopt->sopt_name; 2779 optlen = sopt->sopt_valsize; 2780 } else 2781 level = op = optname = optlen = 0; 2782 2783 if (level != IPPROTO_ICMPV6) { 2784 return EINVAL; 2785 } 2786 2787 switch (op) { 2788 case PRCO_SETOPT: 2789 switch (optname) { 2790 case ICMP6_FILTER: 2791 { 2792 struct icmp6_filter ic6f; 2793 2794 if (optlen != sizeof(ic6f)) { 2795 error = EMSGSIZE; 2796 break; 2797 } 2798 error = sooptcopyin(sopt, &ic6f, optlen, optlen); 2799 if (error == 0) { 2800 INP_WLOCK(inp); 2801 *inp->in6p_icmp6filt = ic6f; 2802 INP_WUNLOCK(inp); 2803 } 2804 break; 2805 } 2806 2807 default: 2808 error = ENOPROTOOPT; 2809 break; 2810 } 2811 break; 2812 2813 case PRCO_GETOPT: 2814 switch (optname) { 2815 case ICMP6_FILTER: 2816 { 2817 struct icmp6_filter ic6f; 2818 2819 INP_RLOCK(inp); 2820 ic6f = *inp->in6p_icmp6filt; 2821 INP_RUNLOCK(inp); 2822 error = sooptcopyout(sopt, &ic6f, sizeof(ic6f)); 2823 break; 2824 } 2825 2826 default: 2827 error = ENOPROTOOPT; 2828 break; 2829 } 2830 break; 2831 } 2832 2833 return (error); 2834 } 2835 2836 /* 2837 * Perform rate limit check. 2838 * Returns 0 if it is okay to send the icmp6 packet. 2839 * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate 2840 * limitation. 2841 * 2842 * XXX per-destination/type check necessary? 2843 * 2844 * dst - not used at this moment 2845 * type - not used at this moment 2846 * code - not used at this moment 2847 */ 2848 static int 2849 icmp6_ratelimit(const struct in6_addr *dst, const int type, 2850 const int code) 2851 { 2852 int ret; 2853 2854 ret = 0; /* okay to send */ 2855 2856 /* PPS limit */ 2857 if (!ppsratecheck(&V_icmp6errppslim_last, &V_icmp6errpps_count, 2858 V_icmp6errppslim)) { 2859 /* The packet is subject to rate limit */ 2860 ret++; 2861 } 2862 2863 return ret; 2864 } 2865