Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/netinet6/icmp6.c
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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: releng/8.3/sys/netinet6/icmp6.c 229638 2012-01-05 19:56:54Z jhb $"); 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_DEFINE(struct icmp6stat, icmp6stat); 117 118 VNET_DECLARE(struct inpcbinfo, ripcbinfo); 119 VNET_DECLARE(struct inpcbhead, ripcb); 120 VNET_DECLARE(int, icmp6errppslim); 121 static VNET_DEFINE(int, icmp6errpps_count) = 0; 122 static VNET_DEFINE(struct timeval, icmp6errppslim_last); 123 VNET_DECLARE(int, icmp6_nodeinfo); 124 125 #define V_ripcbinfo VNET(ripcbinfo) 126 #define V_ripcb VNET(ripcb) 127 #define V_icmp6errppslim VNET(icmp6errppslim) 128 #define V_icmp6errpps_count VNET(icmp6errpps_count) 129 #define V_icmp6errppslim_last VNET(icmp6errppslim_last) 130 #define V_icmp6_nodeinfo VNET(icmp6_nodeinfo) 131 132 static void icmp6_errcount(struct icmp6errstat *, int, int); 133 static int icmp6_rip6_input(struct mbuf **, int); 134 static int icmp6_ratelimit(const struct in6_addr *, const int, const int); 135 static const char *icmp6_redirect_diag __P((struct in6_addr *, 136 struct in6_addr *, struct in6_addr *)); 137 static struct mbuf *ni6_input(struct mbuf *, int); 138 static struct mbuf *ni6_nametodns(const char *, int, int); 139 static int ni6_dnsmatch(const char *, int, const char *, int); 140 static int ni6_addrs __P((struct icmp6_nodeinfo *, struct mbuf *, 141 struct ifnet **, struct in6_addr *)); 142 static int ni6_store_addrs __P((struct icmp6_nodeinfo *, struct icmp6_nodeinfo *, 143 struct ifnet *, int)); 144 static int icmp6_notify_error(struct mbuf **, int, int, int); 145 146 /* 147 * Kernel module interface for updating icmp6stat. The argument is an index 148 * into icmp6stat treated as an array of u_quad_t. While this encodes the 149 * general layout of icmp6stat into the caller, it doesn't encode its 150 * location, so that future changes to add, for example, per-CPU stats 151 * support won't cause binary compatibility problems for kernel modules. 152 */ 153 void 154 kmod_icmp6stat_inc(int statnum) 155 { 156 157 (*((u_quad_t *)&V_icmp6stat + statnum))++; 158 } 159 160 static void 161 icmp6_errcount(struct icmp6errstat *stat, int type, int code) 162 { 163 switch (type) { 164 case ICMP6_DST_UNREACH: 165 switch (code) { 166 case ICMP6_DST_UNREACH_NOROUTE: 167 stat->icp6errs_dst_unreach_noroute++; 168 return; 169 case ICMP6_DST_UNREACH_ADMIN: 170 stat->icp6errs_dst_unreach_admin++; 171 return; 172 case ICMP6_DST_UNREACH_BEYONDSCOPE: 173 stat->icp6errs_dst_unreach_beyondscope++; 174 return; 175 case ICMP6_DST_UNREACH_ADDR: 176 stat->icp6errs_dst_unreach_addr++; 177 return; 178 case ICMP6_DST_UNREACH_NOPORT: 179 stat->icp6errs_dst_unreach_noport++; 180 return; 181 } 182 break; 183 case ICMP6_PACKET_TOO_BIG: 184 stat->icp6errs_packet_too_big++; 185 return; 186 case ICMP6_TIME_EXCEEDED: 187 switch (code) { 188 case ICMP6_TIME_EXCEED_TRANSIT: 189 stat->icp6errs_time_exceed_transit++; 190 return; 191 case ICMP6_TIME_EXCEED_REASSEMBLY: 192 stat->icp6errs_time_exceed_reassembly++; 193 return; 194 } 195 break; 196 case ICMP6_PARAM_PROB: 197 switch (code) { 198 case ICMP6_PARAMPROB_HEADER: 199 stat->icp6errs_paramprob_header++; 200 return; 201 case ICMP6_PARAMPROB_NEXTHEADER: 202 stat->icp6errs_paramprob_nextheader++; 203 return; 204 case ICMP6_PARAMPROB_OPTION: 205 stat->icp6errs_paramprob_option++; 206 return; 207 } 208 break; 209 case ND_REDIRECT: 210 stat->icp6errs_redirect++; 211 return; 212 } 213 stat->icp6errs_unknown++; 214 } 215 216 /* 217 * A wrapper function for icmp6_error() necessary when the erroneous packet 218 * may not contain enough scope zone information. 219 */ 220 void 221 icmp6_error2(struct mbuf *m, int type, int code, int param, 222 struct ifnet *ifp) 223 { 224 struct ip6_hdr *ip6; 225 226 if (ifp == NULL) 227 return; 228 229 #ifndef PULLDOWN_TEST 230 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), ); 231 #else 232 if (m->m_len < sizeof(struct ip6_hdr)) { 233 m = m_pullup(m, sizeof(struct ip6_hdr)); 234 if (m == NULL) 235 return; 236 } 237 #endif 238 239 ip6 = mtod(m, struct ip6_hdr *); 240 241 if (in6_setscope(&ip6->ip6_src, ifp, NULL) != 0) 242 return; 243 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0) 244 return; 245 246 icmp6_error(m, type, code, param); 247 } 248 249 /* 250 * Generate an error packet of type error in response to bad IP6 packet. 251 */ 252 void 253 icmp6_error(struct mbuf *m, int type, int code, int param) 254 { 255 struct ip6_hdr *oip6, *nip6; 256 struct icmp6_hdr *icmp6; 257 u_int preplen; 258 int off; 259 int nxt; 260 261 ICMP6STAT_INC(icp6s_error); 262 263 /* count per-type-code statistics */ 264 icmp6_errcount(&V_icmp6stat.icp6s_outerrhist, type, code); 265 266 #ifdef M_DECRYPTED /*not openbsd*/ 267 if (m->m_flags & M_DECRYPTED) { 268 ICMP6STAT_INC(icp6s_canterror); 269 goto freeit; 270 } 271 #endif 272 273 #ifndef PULLDOWN_TEST 274 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), ); 275 #else 276 if (m->m_len < sizeof(struct ip6_hdr)) { 277 m = m_pullup(m, sizeof(struct ip6_hdr)); 278 if (m == NULL) 279 return; 280 } 281 #endif 282 oip6 = mtod(m, struct ip6_hdr *); 283 284 /* 285 * If the destination address of the erroneous packet is a multicast 286 * address, or the packet was sent using link-layer multicast, 287 * we should basically suppress sending an error (RFC 2463, Section 288 * 2.4). 289 * We have two exceptions (the item e.2 in that section): 290 * - the Packet Too Big message can be sent for path MTU discovery. 291 * - the Parameter Problem Message that can be allowed an icmp6 error 292 * in the option type field. This check has been done in 293 * ip6_unknown_opt(), so we can just check the type and code. 294 */ 295 if ((m->m_flags & (M_BCAST|M_MCAST) || 296 IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) && 297 (type != ICMP6_PACKET_TOO_BIG && 298 (type != ICMP6_PARAM_PROB || 299 code != ICMP6_PARAMPROB_OPTION))) 300 goto freeit; 301 302 /* 303 * RFC 2463, 2.4 (e.5): source address check. 304 * XXX: the case of anycast source? 305 */ 306 if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) || 307 IN6_IS_ADDR_MULTICAST(&oip6->ip6_src)) 308 goto freeit; 309 310 /* 311 * If we are about to send ICMPv6 against ICMPv6 error/redirect, 312 * don't do it. 313 */ 314 nxt = -1; 315 off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt); 316 if (off >= 0 && nxt == IPPROTO_ICMPV6) { 317 struct icmp6_hdr *icp; 318 319 #ifndef PULLDOWN_TEST 320 IP6_EXTHDR_CHECK(m, 0, off + sizeof(struct icmp6_hdr), ); 321 icp = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 322 #else 323 IP6_EXTHDR_GET(icp, struct icmp6_hdr *, m, off, 324 sizeof(*icp)); 325 if (icp == NULL) { 326 ICMP6STAT_INC(icp6s_tooshort); 327 return; 328 } 329 #endif 330 if (icp->icmp6_type < ICMP6_ECHO_REQUEST || 331 icp->icmp6_type == ND_REDIRECT) { 332 /* 333 * ICMPv6 error 334 * Special case: for redirect (which is 335 * informational) we must not send icmp6 error. 336 */ 337 ICMP6STAT_INC(icp6s_canterror); 338 goto freeit; 339 } else { 340 /* ICMPv6 informational - send the error */ 341 } 342 } else { 343 /* non-ICMPv6 - send the error */ 344 } 345 346 oip6 = mtod(m, struct ip6_hdr *); /* adjust pointer */ 347 348 /* Finally, do rate limitation check. */ 349 if (icmp6_ratelimit(&oip6->ip6_src, type, code)) { 350 ICMP6STAT_INC(icp6s_toofreq); 351 goto freeit; 352 } 353 354 /* 355 * OK, ICMP6 can be generated. 356 */ 357 358 if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN) 359 m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len); 360 361 preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 362 M_PREPEND(m, preplen, M_DONTWAIT); 363 if (m && m->m_len < preplen) 364 m = m_pullup(m, preplen); 365 if (m == NULL) { 366 nd6log((LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__)); 367 return; 368 } 369 370 nip6 = mtod(m, struct ip6_hdr *); 371 nip6->ip6_src = oip6->ip6_src; 372 nip6->ip6_dst = oip6->ip6_dst; 373 374 in6_clearscope(&oip6->ip6_src); 375 in6_clearscope(&oip6->ip6_dst); 376 377 icmp6 = (struct icmp6_hdr *)(nip6 + 1); 378 icmp6->icmp6_type = type; 379 icmp6->icmp6_code = code; 380 icmp6->icmp6_pptr = htonl((u_int32_t)param); 381 382 /* 383 * icmp6_reflect() is designed to be in the input path. 384 * icmp6_error() can be called from both input and output path, 385 * and if we are in output path rcvif could contain bogus value. 386 * clear m->m_pkthdr.rcvif for safety, we should have enough scope 387 * information in ip header (nip6). 388 */ 389 m->m_pkthdr.rcvif = NULL; 390 391 ICMP6STAT_INC(icp6s_outhist[type]); 392 icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */ 393 394 return; 395 396 freeit: 397 /* 398 * If we can't tell whether or not we can generate ICMP6, free it. 399 */ 400 m_freem(m); 401 } 402 403 /* 404 * Process a received ICMP6 message. 405 */ 406 int 407 icmp6_input(struct mbuf **mp, int *offp, int proto) 408 { 409 struct mbuf *m = *mp, *n; 410 struct ifnet *ifp; 411 struct ip6_hdr *ip6, *nip6; 412 struct icmp6_hdr *icmp6, *nicmp6; 413 int off = *offp; 414 int icmp6len = m->m_pkthdr.len - *offp; 415 int code, sum, noff; 416 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 417 418 ifp = m->m_pkthdr.rcvif; 419 420 #ifndef PULLDOWN_TEST 421 IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_hdr), IPPROTO_DONE); 422 /* m might change if M_LOOP. So, call mtod after this */ 423 #endif 424 425 /* 426 * Locate icmp6 structure in mbuf, and check 427 * that not corrupted and of at least minimum length 428 */ 429 430 ip6 = mtod(m, struct ip6_hdr *); 431 if (icmp6len < sizeof(struct icmp6_hdr)) { 432 ICMP6STAT_INC(icp6s_tooshort); 433 goto freeit; 434 } 435 436 /* 437 * Check multicast group membership. 438 * Note: SSM filters are not applied for ICMPv6 traffic. 439 */ 440 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 441 struct in6_multi *inm; 442 443 inm = in6m_lookup(ifp, &ip6->ip6_dst); 444 if (inm == NULL) { 445 IP6STAT_INC(ip6s_notmember); 446 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 447 goto freeit; 448 } 449 } 450 451 /* 452 * calculate the checksum 453 */ 454 #ifndef PULLDOWN_TEST 455 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off); 456 #else 457 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6)); 458 if (icmp6 == NULL) { 459 ICMP6STAT_INC(icp6s_tooshort); 460 return IPPROTO_DONE; 461 } 462 #endif 463 code = icmp6->icmp6_code; 464 465 if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) { 466 nd6log((LOG_ERR, 467 "ICMP6 checksum error(%d|%x) %s\n", 468 icmp6->icmp6_type, sum, 469 ip6_sprintf(ip6bufs, &ip6->ip6_src))); 470 ICMP6STAT_INC(icp6s_checksum); 471 goto freeit; 472 } 473 474 if (faithprefix_p != NULL && (*faithprefix_p)(&ip6->ip6_dst)) { 475 /* 476 * Deliver very specific ICMP6 type only. 477 * This is important to deliver TOOBIG. Otherwise PMTUD 478 * will not work. 479 */ 480 switch (icmp6->icmp6_type) { 481 case ICMP6_DST_UNREACH: 482 case ICMP6_PACKET_TOO_BIG: 483 case ICMP6_TIME_EXCEEDED: 484 break; 485 default: 486 goto freeit; 487 } 488 } 489 490 ICMP6STAT_INC(icp6s_inhist[icmp6->icmp6_type]); 491 icmp6_ifstat_inc(ifp, ifs6_in_msg); 492 if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK) 493 icmp6_ifstat_inc(ifp, ifs6_in_error); 494 495 switch (icmp6->icmp6_type) { 496 case ICMP6_DST_UNREACH: 497 icmp6_ifstat_inc(ifp, ifs6_in_dstunreach); 498 switch (code) { 499 case ICMP6_DST_UNREACH_NOROUTE: 500 code = PRC_UNREACH_NET; 501 break; 502 case ICMP6_DST_UNREACH_ADMIN: 503 icmp6_ifstat_inc(ifp, ifs6_in_adminprohib); 504 code = PRC_UNREACH_PROTOCOL; /* is this a good code? */ 505 break; 506 case ICMP6_DST_UNREACH_ADDR: 507 code = PRC_HOSTDEAD; 508 break; 509 case ICMP6_DST_UNREACH_BEYONDSCOPE: 510 /* I mean "source address was incorrect." */ 511 code = PRC_PARAMPROB; 512 break; 513 case ICMP6_DST_UNREACH_NOPORT: 514 code = PRC_UNREACH_PORT; 515 break; 516 default: 517 goto badcode; 518 } 519 goto deliver; 520 break; 521 522 case ICMP6_PACKET_TOO_BIG: 523 icmp6_ifstat_inc(ifp, ifs6_in_pkttoobig); 524 525 /* validation is made in icmp6_mtudisc_update */ 526 527 code = PRC_MSGSIZE; 528 529 /* 530 * Updating the path MTU will be done after examining 531 * intermediate extension headers. 532 */ 533 goto deliver; 534 break; 535 536 case ICMP6_TIME_EXCEEDED: 537 icmp6_ifstat_inc(ifp, ifs6_in_timeexceed); 538 switch (code) { 539 case ICMP6_TIME_EXCEED_TRANSIT: 540 code = PRC_TIMXCEED_INTRANS; 541 break; 542 case ICMP6_TIME_EXCEED_REASSEMBLY: 543 code = PRC_TIMXCEED_REASS; 544 break; 545 default: 546 goto badcode; 547 } 548 goto deliver; 549 break; 550 551 case ICMP6_PARAM_PROB: 552 icmp6_ifstat_inc(ifp, ifs6_in_paramprob); 553 switch (code) { 554 case ICMP6_PARAMPROB_NEXTHEADER: 555 code = PRC_UNREACH_PROTOCOL; 556 break; 557 case ICMP6_PARAMPROB_HEADER: 558 case ICMP6_PARAMPROB_OPTION: 559 code = PRC_PARAMPROB; 560 break; 561 default: 562 goto badcode; 563 } 564 goto deliver; 565 break; 566 567 case ICMP6_ECHO_REQUEST: 568 icmp6_ifstat_inc(ifp, ifs6_in_echo); 569 if (code != 0) 570 goto badcode; 571 if ((n = m_copy(m, 0, M_COPYALL)) == NULL) { 572 /* Give up remote */ 573 break; 574 } 575 if ((n->m_flags & M_EXT) != 0 576 || n->m_len < off + sizeof(struct icmp6_hdr)) { 577 struct mbuf *n0 = n; 578 const int maxlen = sizeof(*nip6) + sizeof(*nicmp6); 579 int n0len; 580 581 MGETHDR(n, M_DONTWAIT, n0->m_type); 582 n0len = n0->m_pkthdr.len; /* save for use below */ 583 if (n) 584 M_MOVE_PKTHDR(n, n0); 585 if (n && maxlen >= MHLEN) { 586 MCLGET(n, M_DONTWAIT); 587 if ((n->m_flags & M_EXT) == 0) { 588 m_free(n); 589 n = NULL; 590 } 591 } 592 if (n == NULL) { 593 /* Give up remote */ 594 m_freem(n0); 595 break; 596 } 597 /* 598 * Copy IPv6 and ICMPv6 only. 599 */ 600 nip6 = mtod(n, struct ip6_hdr *); 601 bcopy(ip6, nip6, sizeof(struct ip6_hdr)); 602 nicmp6 = (struct icmp6_hdr *)(nip6 + 1); 603 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr)); 604 noff = sizeof(struct ip6_hdr); 605 /* new mbuf contains only ipv6+icmpv6 headers */ 606 n->m_len = noff + sizeof(struct icmp6_hdr); 607 /* 608 * Adjust mbuf. ip6_plen will be adjusted in 609 * ip6_output(). 610 */ 611 m_adj(n0, off + sizeof(struct icmp6_hdr)); 612 /* recalculate complete packet size */ 613 n->m_pkthdr.len = n0len + (noff - off); 614 n->m_next = n0; 615 } else { 616 nip6 = mtod(n, struct ip6_hdr *); 617 IP6_EXTHDR_GET(nicmp6, struct icmp6_hdr *, n, off, 618 sizeof(*nicmp6)); 619 noff = off; 620 } 621 nicmp6->icmp6_type = ICMP6_ECHO_REPLY; 622 nicmp6->icmp6_code = 0; 623 if (n) { 624 ICMP6STAT_INC(icp6s_reflect); 625 ICMP6STAT_INC(icp6s_outhist[ICMP6_ECHO_REPLY]); 626 icmp6_reflect(n, noff); 627 } 628 break; 629 630 case ICMP6_ECHO_REPLY: 631 icmp6_ifstat_inc(ifp, ifs6_in_echoreply); 632 if (code != 0) 633 goto badcode; 634 break; 635 636 case MLD_LISTENER_QUERY: 637 case MLD_LISTENER_REPORT: 638 case MLD_LISTENER_DONE: 639 case MLDV2_LISTENER_REPORT: 640 /* 641 * Drop MLD traffic which is not link-local, has a hop limit 642 * of greater than 1 hop, or which does not have the 643 * IPv6 HBH Router Alert option. 644 * As IPv6 HBH options are stripped in ip6_input() we must 645 * check an mbuf header flag. 646 * XXX Should we also sanity check that these messages 647 * were directed to a link-local multicast prefix? 648 */ 649 if ((ip6->ip6_hlim != 1) || (m->m_flags & M_RTALERT_MLD) == 0) 650 goto freeit; 651 if (mld_input(m, off, icmp6len) != 0) 652 return (IPPROTO_DONE); 653 /* m stays. */ 654 break; 655 656 case ICMP6_WRUREQUEST: /* ICMP6_FQDN_QUERY */ 657 { 658 enum { WRU, FQDN } mode; 659 660 if (!V_icmp6_nodeinfo) 661 break; 662 663 if (icmp6len == sizeof(struct icmp6_hdr) + 4) 664 mode = WRU; 665 else if (icmp6len >= sizeof(struct icmp6_nodeinfo)) 666 mode = FQDN; 667 else 668 goto badlen; 669 670 if (mode == FQDN) { 671 #ifndef PULLDOWN_TEST 672 IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_nodeinfo), 673 IPPROTO_DONE); 674 #endif 675 n = m_copy(m, 0, M_COPYALL); 676 if (n) 677 n = ni6_input(n, off); 678 /* XXX meaningless if n == NULL */ 679 noff = sizeof(struct ip6_hdr); 680 } else { 681 struct prison *pr; 682 u_char *p; 683 int maxlen, maxhlen, hlen; 684 685 /* 686 * XXX: this combination of flags is pointless, 687 * but should we keep this for compatibility? 688 */ 689 if ((V_icmp6_nodeinfo & 5) != 5) 690 break; 691 692 if (code != 0) 693 goto badcode; 694 maxlen = sizeof(*nip6) + sizeof(*nicmp6) + 4; 695 if (maxlen >= MCLBYTES) { 696 /* Give up remote */ 697 break; 698 } 699 MGETHDR(n, M_DONTWAIT, m->m_type); 700 if (n && maxlen > MHLEN) { 701 MCLGET(n, M_DONTWAIT); 702 if ((n->m_flags & M_EXT) == 0) { 703 m_free(n); 704 n = NULL; 705 } 706 } 707 if (n && !m_dup_pkthdr(n, m, M_DONTWAIT)) { 708 /* 709 * Previous code did a blind M_COPY_PKTHDR 710 * and said "just for rcvif". If true, then 711 * we could tolerate the dup failing (due to 712 * the deep copy of the tag chain). For now 713 * be conservative and just fail. 714 */ 715 m_free(n); 716 n = NULL; 717 } 718 if (n == NULL) { 719 /* Give up remote */ 720 break; 721 } 722 n->m_pkthdr.rcvif = NULL; 723 n->m_len = 0; 724 maxhlen = M_TRAILINGSPACE(n) - maxlen; 725 pr = curthread->td_ucred->cr_prison; 726 mtx_lock(&pr->pr_mtx); 727 hlen = strlen(pr->pr_hostname); 728 if (maxhlen > hlen) 729 maxhlen = hlen; 730 /* 731 * Copy IPv6 and ICMPv6 only. 732 */ 733 nip6 = mtod(n, struct ip6_hdr *); 734 bcopy(ip6, nip6, sizeof(struct ip6_hdr)); 735 nicmp6 = (struct icmp6_hdr *)(nip6 + 1); 736 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr)); 737 p = (u_char *)(nicmp6 + 1); 738 bzero(p, 4); 739 /* meaningless TTL */ 740 bcopy(pr->pr_hostname, p + 4, maxhlen); 741 mtx_unlock(&pr->pr_mtx); 742 noff = sizeof(struct ip6_hdr); 743 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + 744 sizeof(struct icmp6_hdr) + 4 + maxhlen; 745 nicmp6->icmp6_type = ICMP6_WRUREPLY; 746 nicmp6->icmp6_code = 0; 747 } 748 if (n) { 749 ICMP6STAT_INC(icp6s_reflect); 750 ICMP6STAT_INC(icp6s_outhist[ICMP6_WRUREPLY]); 751 icmp6_reflect(n, noff); 752 } 753 break; 754 } 755 756 case ICMP6_WRUREPLY: 757 if (code != 0) 758 goto badcode; 759 break; 760 761 case ND_ROUTER_SOLICIT: 762 icmp6_ifstat_inc(ifp, ifs6_in_routersolicit); 763 if (code != 0) 764 goto badcode; 765 if (icmp6len < sizeof(struct nd_router_solicit)) 766 goto badlen; 767 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 768 /* give up local */ 769 nd6_rs_input(m, off, icmp6len); 770 m = NULL; 771 goto freeit; 772 } 773 nd6_rs_input(n, off, icmp6len); 774 /* m stays. */ 775 break; 776 777 case ND_ROUTER_ADVERT: 778 icmp6_ifstat_inc(ifp, ifs6_in_routeradvert); 779 if (code != 0) 780 goto badcode; 781 if (icmp6len < sizeof(struct nd_router_advert)) 782 goto badlen; 783 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 784 /* give up local */ 785 nd6_ra_input(m, off, icmp6len); 786 m = NULL; 787 goto freeit; 788 } 789 nd6_ra_input(n, off, icmp6len); 790 /* m stays. */ 791 break; 792 793 case ND_NEIGHBOR_SOLICIT: 794 icmp6_ifstat_inc(ifp, ifs6_in_neighborsolicit); 795 if (code != 0) 796 goto badcode; 797 if (icmp6len < sizeof(struct nd_neighbor_solicit)) 798 goto badlen; 799 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 800 /* give up local */ 801 nd6_ns_input(m, off, icmp6len); 802 m = NULL; 803 goto freeit; 804 } 805 nd6_ns_input(n, off, icmp6len); 806 /* m stays. */ 807 break; 808 809 case ND_NEIGHBOR_ADVERT: 810 icmp6_ifstat_inc(ifp, ifs6_in_neighboradvert); 811 if (code != 0) 812 goto badcode; 813 if (icmp6len < sizeof(struct nd_neighbor_advert)) 814 goto badlen; 815 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 816 /* give up local */ 817 nd6_na_input(m, off, icmp6len); 818 m = NULL; 819 goto freeit; 820 } 821 nd6_na_input(n, off, icmp6len); 822 /* m stays. */ 823 break; 824 825 case ND_REDIRECT: 826 icmp6_ifstat_inc(ifp, ifs6_in_redirect); 827 if (code != 0) 828 goto badcode; 829 if (icmp6len < sizeof(struct nd_redirect)) 830 goto badlen; 831 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 832 /* give up local */ 833 icmp6_redirect_input(m, off); 834 m = NULL; 835 goto freeit; 836 } 837 icmp6_redirect_input(n, off); 838 /* m stays. */ 839 break; 840 841 case ICMP6_ROUTER_RENUMBERING: 842 if (code != ICMP6_ROUTER_RENUMBERING_COMMAND && 843 code != ICMP6_ROUTER_RENUMBERING_RESULT) 844 goto badcode; 845 if (icmp6len < sizeof(struct icmp6_router_renum)) 846 goto badlen; 847 break; 848 849 default: 850 nd6log((LOG_DEBUG, 851 "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n", 852 icmp6->icmp6_type, ip6_sprintf(ip6bufs, &ip6->ip6_src), 853 ip6_sprintf(ip6bufd, &ip6->ip6_dst), 854 ifp ? ifp->if_index : 0)); 855 if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) { 856 /* ICMPv6 error: MUST deliver it by spec... */ 857 code = PRC_NCMDS; 858 /* deliver */ 859 } else { 860 /* ICMPv6 informational: MUST not deliver */ 861 break; 862 } 863 deliver: 864 if (icmp6_notify_error(&m, off, icmp6len, code) != 0) { 865 /* In this case, m should've been freed. */ 866 return (IPPROTO_DONE); 867 } 868 break; 869 870 badcode: 871 ICMP6STAT_INC(icp6s_badcode); 872 break; 873 874 badlen: 875 ICMP6STAT_INC(icp6s_badlen); 876 break; 877 } 878 879 /* deliver the packet to appropriate sockets */ 880 icmp6_rip6_input(&m, *offp); 881 882 return IPPROTO_DONE; 883 884 freeit: 885 m_freem(m); 886 return IPPROTO_DONE; 887 } 888 889 static int 890 icmp6_notify_error(struct mbuf **mp, int off, int icmp6len, int code) 891 { 892 struct mbuf *m = *mp; 893 struct icmp6_hdr *icmp6; 894 struct ip6_hdr *eip6; 895 u_int32_t notifymtu; 896 struct sockaddr_in6 icmp6src, icmp6dst; 897 898 if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) { 899 ICMP6STAT_INC(icp6s_tooshort); 900 goto freeit; 901 } 902 #ifndef PULLDOWN_TEST 903 IP6_EXTHDR_CHECK(m, off, 904 sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr), -1); 905 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 906 #else 907 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, 908 sizeof(*icmp6) + sizeof(struct ip6_hdr)); 909 if (icmp6 == NULL) { 910 ICMP6STAT_INC(icp6s_tooshort); 911 return (-1); 912 } 913 #endif 914 eip6 = (struct ip6_hdr *)(icmp6 + 1); 915 916 /* Detect the upper level protocol */ 917 { 918 void (*ctlfunc)(int, struct sockaddr *, void *); 919 u_int8_t nxt = eip6->ip6_nxt; 920 int eoff = off + sizeof(struct icmp6_hdr) + 921 sizeof(struct ip6_hdr); 922 struct ip6ctlparam ip6cp; 923 struct in6_addr *finaldst = NULL; 924 int icmp6type = icmp6->icmp6_type; 925 struct ip6_frag *fh; 926 struct ip6_rthdr *rth; 927 struct ip6_rthdr0 *rth0; 928 int rthlen; 929 930 while (1) { /* XXX: should avoid infinite loop explicitly? */ 931 struct ip6_ext *eh; 932 933 switch (nxt) { 934 case IPPROTO_HOPOPTS: 935 case IPPROTO_DSTOPTS: 936 case IPPROTO_AH: 937 #ifndef PULLDOWN_TEST 938 IP6_EXTHDR_CHECK(m, 0, 939 eoff + sizeof(struct ip6_ext), -1); 940 eh = (struct ip6_ext *)(mtod(m, caddr_t) + eoff); 941 #else 942 IP6_EXTHDR_GET(eh, struct ip6_ext *, m, 943 eoff, sizeof(*eh)); 944 if (eh == NULL) { 945 ICMP6STAT_INC(icp6s_tooshort); 946 return (-1); 947 } 948 #endif 949 950 if (nxt == IPPROTO_AH) 951 eoff += (eh->ip6e_len + 2) << 2; 952 else 953 eoff += (eh->ip6e_len + 1) << 3; 954 nxt = eh->ip6e_nxt; 955 break; 956 case IPPROTO_ROUTING: 957 /* 958 * When the erroneous packet contains a 959 * routing header, we should examine the 960 * header to determine the final destination. 961 * Otherwise, we can't properly update 962 * information that depends on the final 963 * destination (e.g. path MTU). 964 */ 965 #ifndef PULLDOWN_TEST 966 IP6_EXTHDR_CHECK(m, 0, eoff + sizeof(*rth), -1); 967 rth = (struct ip6_rthdr *) 968 (mtod(m, caddr_t) + eoff); 969 #else 970 IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m, 971 eoff, sizeof(*rth)); 972 if (rth == NULL) { 973 ICMP6STAT_INC(icp6s_tooshort); 974 return (-1); 975 } 976 #endif 977 rthlen = (rth->ip6r_len + 1) << 3; 978 /* 979 * XXX: currently there is no 980 * officially defined type other 981 * than type-0. 982 * Note that if the segment left field 983 * is 0, all intermediate hops must 984 * have been passed. 985 */ 986 if (rth->ip6r_segleft && 987 rth->ip6r_type == IPV6_RTHDR_TYPE_0) { 988 int hops; 989 990 #ifndef PULLDOWN_TEST 991 IP6_EXTHDR_CHECK(m, 0, eoff + rthlen, -1); 992 rth0 = (struct ip6_rthdr0 *) 993 (mtod(m, caddr_t) + eoff); 994 #else 995 IP6_EXTHDR_GET(rth0, 996 struct ip6_rthdr0 *, m, 997 eoff, rthlen); 998 if (rth0 == NULL) { 999 ICMP6STAT_INC(icp6s_tooshort); 1000 return (-1); 1001 } 1002 #endif 1003 /* just ignore a bogus header */ 1004 if ((rth0->ip6r0_len % 2) == 0 && 1005 (hops = rth0->ip6r0_len/2)) 1006 finaldst = (struct in6_addr *)(rth0 + 1) + (hops - 1); 1007 } 1008 eoff += rthlen; 1009 nxt = rth->ip6r_nxt; 1010 break; 1011 case IPPROTO_FRAGMENT: 1012 #ifndef PULLDOWN_TEST 1013 IP6_EXTHDR_CHECK(m, 0, eoff + 1014 sizeof(struct ip6_frag), -1); 1015 fh = (struct ip6_frag *)(mtod(m, caddr_t) + 1016 eoff); 1017 #else 1018 IP6_EXTHDR_GET(fh, struct ip6_frag *, m, 1019 eoff, sizeof(*fh)); 1020 if (fh == NULL) { 1021 ICMP6STAT_INC(icp6s_tooshort); 1022 return (-1); 1023 } 1024 #endif 1025 /* 1026 * Data after a fragment header is meaningless 1027 * unless it is the first fragment, but 1028 * we'll go to the notify label for path MTU 1029 * discovery. 1030 */ 1031 if (fh->ip6f_offlg & IP6F_OFF_MASK) 1032 goto notify; 1033 1034 eoff += sizeof(struct ip6_frag); 1035 nxt = fh->ip6f_nxt; 1036 break; 1037 default: 1038 /* 1039 * This case includes ESP and the No Next 1040 * Header. In such cases going to the notify 1041 * label does not have any meaning 1042 * (i.e. ctlfunc will be NULL), but we go 1043 * anyway since we might have to update 1044 * path MTU information. 1045 */ 1046 goto notify; 1047 } 1048 } 1049 notify: 1050 #ifndef PULLDOWN_TEST 1051 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 1052 #else 1053 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, 1054 sizeof(*icmp6) + sizeof(struct ip6_hdr)); 1055 if (icmp6 == NULL) { 1056 ICMP6STAT_INC(icp6s_tooshort); 1057 return (-1); 1058 } 1059 #endif 1060 1061 /* 1062 * retrieve parameters from the inner IPv6 header, and convert 1063 * them into sockaddr structures. 1064 * XXX: there is no guarantee that the source or destination 1065 * addresses of the inner packet are in the same scope as 1066 * the addresses of the icmp packet. But there is no other 1067 * way to determine the zone. 1068 */ 1069 eip6 = (struct ip6_hdr *)(icmp6 + 1); 1070 1071 bzero(&icmp6dst, sizeof(icmp6dst)); 1072 icmp6dst.sin6_len = sizeof(struct sockaddr_in6); 1073 icmp6dst.sin6_family = AF_INET6; 1074 if (finaldst == NULL) 1075 icmp6dst.sin6_addr = eip6->ip6_dst; 1076 else 1077 icmp6dst.sin6_addr = *finaldst; 1078 if (in6_setscope(&icmp6dst.sin6_addr, m->m_pkthdr.rcvif, NULL)) 1079 goto freeit; 1080 bzero(&icmp6src, sizeof(icmp6src)); 1081 icmp6src.sin6_len = sizeof(struct sockaddr_in6); 1082 icmp6src.sin6_family = AF_INET6; 1083 icmp6src.sin6_addr = eip6->ip6_src; 1084 if (in6_setscope(&icmp6src.sin6_addr, m->m_pkthdr.rcvif, NULL)) 1085 goto freeit; 1086 icmp6src.sin6_flowinfo = 1087 (eip6->ip6_flow & IPV6_FLOWLABEL_MASK); 1088 1089 if (finaldst == NULL) 1090 finaldst = &eip6->ip6_dst; 1091 ip6cp.ip6c_m = m; 1092 ip6cp.ip6c_icmp6 = icmp6; 1093 ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1); 1094 ip6cp.ip6c_off = eoff; 1095 ip6cp.ip6c_finaldst = finaldst; 1096 ip6cp.ip6c_src = &icmp6src; 1097 ip6cp.ip6c_nxt = nxt; 1098 1099 if (icmp6type == ICMP6_PACKET_TOO_BIG) { 1100 notifymtu = ntohl(icmp6->icmp6_mtu); 1101 ip6cp.ip6c_cmdarg = (void *)¬ifymtu; 1102 icmp6_mtudisc_update(&ip6cp, 1); /*XXX*/ 1103 } 1104 1105 ctlfunc = (void (*)(int, struct sockaddr *, void *)) 1106 (inet6sw[ip6_protox[nxt]].pr_ctlinput); 1107 if (ctlfunc) { 1108 (void) (*ctlfunc)(code, (struct sockaddr *)&icmp6dst, 1109 &ip6cp); 1110 } 1111 } 1112 *mp = m; 1113 return (0); 1114 1115 freeit: 1116 m_freem(m); 1117 return (-1); 1118 } 1119 1120 void 1121 icmp6_mtudisc_update(struct ip6ctlparam *ip6cp, int validated) 1122 { 1123 struct in6_addr *dst = ip6cp->ip6c_finaldst; 1124 struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6; 1125 struct mbuf *m = ip6cp->ip6c_m; /* will be necessary for scope issue */ 1126 u_int mtu = ntohl(icmp6->icmp6_mtu); 1127 struct in_conninfo inc; 1128 1129 #if 0 1130 /* 1131 * RFC2460 section 5, last paragraph. 1132 * even though minimum link MTU for IPv6 is IPV6_MMTU, 1133 * we may see ICMPv6 too big with mtu < IPV6_MMTU 1134 * due to packet translator in the middle. 1135 * see ip6_output() and ip6_getpmtu() "alwaysfrag" case for 1136 * special handling. 1137 */ 1138 if (mtu < IPV6_MMTU) 1139 return; 1140 #endif 1141 1142 /* 1143 * we reject ICMPv6 too big with abnormally small value. 1144 * XXX what is the good definition of "abnormally small"? 1145 */ 1146 if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8) 1147 return; 1148 1149 if (!validated) 1150 return; 1151 1152 /* 1153 * In case the suggested mtu is less than IPV6_MMTU, we 1154 * only need to remember that it was for above mentioned 1155 * "alwaysfrag" case. 1156 * Try to be as close to the spec as possible. 1157 */ 1158 if (mtu < IPV6_MMTU) 1159 mtu = IPV6_MMTU - 8; 1160 1161 bzero(&inc, sizeof(inc)); 1162 inc.inc_flags |= INC_ISIPV6; 1163 inc.inc6_faddr = *dst; 1164 if (in6_setscope(&inc.inc6_faddr, m->m_pkthdr.rcvif, NULL)) 1165 return; 1166 1167 if (mtu < tcp_maxmtu6(&inc, NULL)) { 1168 tcp_hc_updatemtu(&inc, mtu); 1169 ICMP6STAT_INC(icp6s_pmtuchg); 1170 } 1171 } 1172 1173 /* 1174 * Process a Node Information Query packet, based on 1175 * draft-ietf-ipngwg-icmp-name-lookups-07. 1176 * 1177 * Spec incompatibilities: 1178 * - IPv6 Subject address handling 1179 * - IPv4 Subject address handling support missing 1180 * - Proxy reply (answer even if it's not for me) 1181 * - joins NI group address at in6_ifattach() time only, does not cope 1182 * with hostname changes by sethostname(3) 1183 */ 1184 static struct mbuf * 1185 ni6_input(struct mbuf *m, int off) 1186 { 1187 struct icmp6_nodeinfo *ni6, *nni6; 1188 struct mbuf *n = NULL; 1189 struct prison *pr; 1190 u_int16_t qtype; 1191 int subjlen; 1192 int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); 1193 struct ni_reply_fqdn *fqdn; 1194 int addrs; /* for NI_QTYPE_NODEADDR */ 1195 struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */ 1196 struct in6_addr in6_subj; /* subject address */ 1197 struct ip6_hdr *ip6; 1198 int oldfqdn = 0; /* if 1, return pascal string (03 draft) */ 1199 char *subj = NULL; 1200 struct in6_ifaddr *ia6 = NULL; 1201 1202 ip6 = mtod(m, struct ip6_hdr *); 1203 #ifndef PULLDOWN_TEST 1204 ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off); 1205 #else 1206 IP6_EXTHDR_GET(ni6, struct icmp6_nodeinfo *, m, off, sizeof(*ni6)); 1207 if (ni6 == NULL) { 1208 /* m is already reclaimed */ 1209 return (NULL); 1210 } 1211 #endif 1212 1213 /* 1214 * Validate IPv6 source address. 1215 * The default configuration MUST be to refuse answering queries from 1216 * global-scope addresses according to RFC4602. 1217 * Notes: 1218 * - it's not very clear what "refuse" means; this implementation 1219 * simply drops it. 1220 * - it's not very easy to identify global-scope (unicast) addresses 1221 * since there are many prefixes for them. It should be safer 1222 * and in practice sufficient to check "all" but loopback and 1223 * link-local (note that site-local unicast was deprecated and 1224 * ULA is defined as global scope-wise) 1225 */ 1226 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_GLOBALOK) == 0 && 1227 !IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) && 1228 !IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) 1229 goto bad; 1230 1231 /* 1232 * Validate IPv6 destination address. 1233 * 1234 * The Responder must discard the Query without further processing 1235 * unless it is one of the Responder's unicast or anycast addresses, or 1236 * a link-local scope multicast address which the Responder has joined. 1237 * [RFC4602, Section 5.] 1238 */ 1239 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 1240 if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst)) 1241 goto bad; 1242 /* else it's a link-local multicast, fine */ 1243 } else { /* unicast or anycast */ 1244 if ((ia6 = ip6_getdstifaddr(m)) == NULL) 1245 goto bad; /* XXX impossible */ 1246 1247 if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) && 1248 !(V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK)) { 1249 ifa_free(&ia6->ia_ifa); 1250 nd6log((LOG_DEBUG, "ni6_input: ignore node info to " 1251 "a temporary address in %s:%d", 1252 __FILE__, __LINE__)); 1253 goto bad; 1254 } 1255 ifa_free(&ia6->ia_ifa); 1256 } 1257 1258 /* validate query Subject field. */ 1259 qtype = ntohs(ni6->ni_qtype); 1260 subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo); 1261 switch (qtype) { 1262 case NI_QTYPE_NOOP: 1263 case NI_QTYPE_SUPTYPES: 1264 /* 07 draft */ 1265 if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0) 1266 break; 1267 /* FALLTHROUGH */ 1268 case NI_QTYPE_FQDN: 1269 case NI_QTYPE_NODEADDR: 1270 case NI_QTYPE_IPV4ADDR: 1271 switch (ni6->ni_code) { 1272 case ICMP6_NI_SUBJ_IPV6: 1273 #if ICMP6_NI_SUBJ_IPV6 != 0 1274 case 0: 1275 #endif 1276 /* 1277 * backward compatibility - try to accept 03 draft 1278 * format, where no Subject is present. 1279 */ 1280 if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 && 1281 subjlen == 0) { 1282 oldfqdn++; 1283 break; 1284 } 1285 #if ICMP6_NI_SUBJ_IPV6 != 0 1286 if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6) 1287 goto bad; 1288 #endif 1289 1290 if (subjlen != sizeof(struct in6_addr)) 1291 goto bad; 1292 1293 /* 1294 * Validate Subject address. 1295 * 1296 * Not sure what exactly "address belongs to the node" 1297 * means in the spec, is it just unicast, or what? 1298 * 1299 * At this moment we consider Subject address as 1300 * "belong to the node" if the Subject address equals 1301 * to the IPv6 destination address; validation for 1302 * IPv6 destination address should have done enough 1303 * check for us. 1304 * 1305 * We do not do proxy at this moment. 1306 */ 1307 /* m_pulldown instead of copy? */ 1308 m_copydata(m, off + sizeof(struct icmp6_nodeinfo), 1309 subjlen, (caddr_t)&in6_subj); 1310 if (in6_setscope(&in6_subj, m->m_pkthdr.rcvif, NULL)) 1311 goto bad; 1312 1313 subj = (char *)&in6_subj; 1314 if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &in6_subj)) 1315 break; 1316 1317 /* 1318 * XXX if we are to allow other cases, we should really 1319 * be careful about scope here. 1320 * basically, we should disallow queries toward IPv6 1321 * destination X with subject Y, 1322 * if scope(X) > scope(Y). 1323 * if we allow scope(X) > scope(Y), it will result in 1324 * information leakage across scope boundary. 1325 */ 1326 goto bad; 1327 1328 case ICMP6_NI_SUBJ_FQDN: 1329 /* 1330 * Validate Subject name with gethostname(3). 1331 * 1332 * The behavior may need some debate, since: 1333 * - we are not sure if the node has FQDN as 1334 * hostname (returned by gethostname(3)). 1335 * - the code does wildcard match for truncated names. 1336 * however, we are not sure if we want to perform 1337 * wildcard match, if gethostname(3) side has 1338 * truncated hostname. 1339 */ 1340 pr = curthread->td_ucred->cr_prison; 1341 mtx_lock(&pr->pr_mtx); 1342 n = ni6_nametodns(pr->pr_hostname, 1343 strlen(pr->pr_hostname), 0); 1344 mtx_unlock(&pr->pr_mtx); 1345 if (!n || n->m_next || n->m_len == 0) 1346 goto bad; 1347 IP6_EXTHDR_GET(subj, char *, m, 1348 off + sizeof(struct icmp6_nodeinfo), subjlen); 1349 if (subj == NULL) 1350 goto bad; 1351 if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *), 1352 n->m_len)) { 1353 goto bad; 1354 } 1355 m_freem(n); 1356 n = NULL; 1357 break; 1358 1359 case ICMP6_NI_SUBJ_IPV4: /* XXX: to be implemented? */ 1360 default: 1361 goto bad; 1362 } 1363 break; 1364 } 1365 1366 /* refuse based on configuration. XXX ICMP6_NI_REFUSED? */ 1367 switch (qtype) { 1368 case NI_QTYPE_FQDN: 1369 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_FQDNOK) == 0) 1370 goto bad; 1371 break; 1372 case NI_QTYPE_NODEADDR: 1373 case NI_QTYPE_IPV4ADDR: 1374 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_NODEADDROK) == 0) 1375 goto bad; 1376 break; 1377 } 1378 1379 /* guess reply length */ 1380 switch (qtype) { 1381 case NI_QTYPE_NOOP: 1382 break; /* no reply data */ 1383 case NI_QTYPE_SUPTYPES: 1384 replylen += sizeof(u_int32_t); 1385 break; 1386 case NI_QTYPE_FQDN: 1387 /* XXX will append an mbuf */ 1388 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); 1389 break; 1390 case NI_QTYPE_NODEADDR: 1391 addrs = ni6_addrs(ni6, m, &ifp, (struct in6_addr *)subj); 1392 if ((replylen += addrs * (sizeof(struct in6_addr) + 1393 sizeof(u_int32_t))) > MCLBYTES) 1394 replylen = MCLBYTES; /* XXX: will truncate pkt later */ 1395 break; 1396 case NI_QTYPE_IPV4ADDR: 1397 /* unsupported - should respond with unknown Qtype? */ 1398 break; 1399 default: 1400 /* 1401 * XXX: We must return a reply with the ICMP6 code 1402 * `unknown Qtype' in this case. However we regard the case 1403 * as an FQDN query for backward compatibility. 1404 * Older versions set a random value to this field, 1405 * so it rarely varies in the defined qtypes. 1406 * But the mechanism is not reliable... 1407 * maybe we should obsolete older versions. 1408 */ 1409 qtype = NI_QTYPE_FQDN; 1410 /* XXX will append an mbuf */ 1411 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); 1412 oldfqdn++; 1413 break; 1414 } 1415 1416 /* allocate an mbuf to reply. */ 1417 MGETHDR(n, M_DONTWAIT, m->m_type); 1418 if (n == NULL) { 1419 m_freem(m); 1420 return (NULL); 1421 } 1422 M_MOVE_PKTHDR(n, m); /* just for recvif */ 1423 if (replylen > MHLEN) { 1424 if (replylen > MCLBYTES) { 1425 /* 1426 * XXX: should we try to allocate more? But MCLBYTES 1427 * is probably much larger than IPV6_MMTU... 1428 */ 1429 goto bad; 1430 } 1431 MCLGET(n, M_DONTWAIT); 1432 if ((n->m_flags & M_EXT) == 0) { 1433 goto bad; 1434 } 1435 } 1436 n->m_pkthdr.len = n->m_len = replylen; 1437 1438 /* copy mbuf header and IPv6 + Node Information base headers */ 1439 bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr)); 1440 nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1); 1441 bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo)); 1442 1443 /* qtype dependent procedure */ 1444 switch (qtype) { 1445 case NI_QTYPE_NOOP: 1446 nni6->ni_code = ICMP6_NI_SUCCESS; 1447 nni6->ni_flags = 0; 1448 break; 1449 case NI_QTYPE_SUPTYPES: 1450 { 1451 u_int32_t v; 1452 nni6->ni_code = ICMP6_NI_SUCCESS; 1453 nni6->ni_flags = htons(0x0000); /* raw bitmap */ 1454 /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */ 1455 v = (u_int32_t)htonl(0x0000000f); 1456 bcopy(&v, nni6 + 1, sizeof(u_int32_t)); 1457 break; 1458 } 1459 case NI_QTYPE_FQDN: 1460 nni6->ni_code = ICMP6_NI_SUCCESS; 1461 fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) + 1462 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo)); 1463 nni6->ni_flags = 0; /* XXX: meaningless TTL */ 1464 fqdn->ni_fqdn_ttl = 0; /* ditto. */ 1465 /* 1466 * XXX do we really have FQDN in hostname? 1467 */ 1468 pr = curthread->td_ucred->cr_prison; 1469 mtx_lock(&pr->pr_mtx); 1470 n->m_next = ni6_nametodns(pr->pr_hostname, 1471 strlen(pr->pr_hostname), oldfqdn); 1472 mtx_unlock(&pr->pr_mtx); 1473 if (n->m_next == NULL) 1474 goto bad; 1475 /* XXX we assume that n->m_next is not a chain */ 1476 if (n->m_next->m_next != NULL) 1477 goto bad; 1478 n->m_pkthdr.len += n->m_next->m_len; 1479 break; 1480 case NI_QTYPE_NODEADDR: 1481 { 1482 int lenlim, copied; 1483 1484 nni6->ni_code = ICMP6_NI_SUCCESS; 1485 n->m_pkthdr.len = n->m_len = 1486 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); 1487 lenlim = M_TRAILINGSPACE(n); 1488 copied = ni6_store_addrs(ni6, nni6, ifp, lenlim); 1489 /* XXX: reset mbuf length */ 1490 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + 1491 sizeof(struct icmp6_nodeinfo) + copied; 1492 break; 1493 } 1494 default: 1495 break; /* XXX impossible! */ 1496 } 1497 1498 nni6->ni_type = ICMP6_NI_REPLY; 1499 m_freem(m); 1500 return (n); 1501 1502 bad: 1503 m_freem(m); 1504 if (n) 1505 m_freem(n); 1506 return (NULL); 1507 } 1508 1509 /* 1510 * make a mbuf with DNS-encoded string. no compression support. 1511 * 1512 * XXX names with less than 2 dots (like "foo" or "foo.section") will be 1513 * treated as truncated name (two \0 at the end). this is a wild guess. 1514 * 1515 * old - return pascal string if non-zero 1516 */ 1517 static struct mbuf * 1518 ni6_nametodns(const char *name, int namelen, int old) 1519 { 1520 struct mbuf *m; 1521 char *cp, *ep; 1522 const char *p, *q; 1523 int i, len, nterm; 1524 1525 if (old) 1526 len = namelen + 1; 1527 else 1528 len = MCLBYTES; 1529 1530 /* because MAXHOSTNAMELEN is usually 256, we use cluster mbuf */ 1531 MGET(m, M_DONTWAIT, MT_DATA); 1532 if (m && len > MLEN) { 1533 MCLGET(m, M_DONTWAIT); 1534 if ((m->m_flags & M_EXT) == 0) 1535 goto fail; 1536 } 1537 if (!m) 1538 goto fail; 1539 m->m_next = NULL; 1540 1541 if (old) { 1542 m->m_len = len; 1543 *mtod(m, char *) = namelen; 1544 bcopy(name, mtod(m, char *) + 1, namelen); 1545 return m; 1546 } else { 1547 m->m_len = 0; 1548 cp = mtod(m, char *); 1549 ep = mtod(m, char *) + M_TRAILINGSPACE(m); 1550 1551 /* if not certain about my name, return empty buffer */ 1552 if (namelen == 0) 1553 return m; 1554 1555 /* 1556 * guess if it looks like shortened hostname, or FQDN. 1557 * shortened hostname needs two trailing "\0". 1558 */ 1559 i = 0; 1560 for (p = name; p < name + namelen; p++) { 1561 if (*p && *p == '.') 1562 i++; 1563 } 1564 if (i < 2) 1565 nterm = 2; 1566 else 1567 nterm = 1; 1568 1569 p = name; 1570 while (cp < ep && p < name + namelen) { 1571 i = 0; 1572 for (q = p; q < name + namelen && *q && *q != '.'; q++) 1573 i++; 1574 /* result does not fit into mbuf */ 1575 if (cp + i + 1 >= ep) 1576 goto fail; 1577 /* 1578 * DNS label length restriction, RFC1035 page 8. 1579 * "i == 0" case is included here to avoid returning 1580 * 0-length label on "foo..bar". 1581 */ 1582 if (i <= 0 || i >= 64) 1583 goto fail; 1584 *cp++ = i; 1585 bcopy(p, cp, i); 1586 cp += i; 1587 p = q; 1588 if (p < name + namelen && *p == '.') 1589 p++; 1590 } 1591 /* termination */ 1592 if (cp + nterm >= ep) 1593 goto fail; 1594 while (nterm-- > 0) 1595 *cp++ = '\0'; 1596 m->m_len = cp - mtod(m, char *); 1597 return m; 1598 } 1599 1600 panic("should not reach here"); 1601 /* NOTREACHED */ 1602 1603 fail: 1604 if (m) 1605 m_freem(m); 1606 return NULL; 1607 } 1608 1609 /* 1610 * check if two DNS-encoded string matches. takes care of truncated 1611 * form (with \0\0 at the end). no compression support. 1612 * XXX upper/lowercase match (see RFC2065) 1613 */ 1614 static int 1615 ni6_dnsmatch(const char *a, int alen, const char *b, int blen) 1616 { 1617 const char *a0, *b0; 1618 int l; 1619 1620 /* simplest case - need validation? */ 1621 if (alen == blen && bcmp(a, b, alen) == 0) 1622 return 1; 1623 1624 a0 = a; 1625 b0 = b; 1626 1627 /* termination is mandatory */ 1628 if (alen < 2 || blen < 2) 1629 return 0; 1630 if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0') 1631 return 0; 1632 alen--; 1633 blen--; 1634 1635 while (a - a0 < alen && b - b0 < blen) { 1636 if (a - a0 + 1 > alen || b - b0 + 1 > blen) 1637 return 0; 1638 1639 if ((signed char)a[0] < 0 || (signed char)b[0] < 0) 1640 return 0; 1641 /* we don't support compression yet */ 1642 if (a[0] >= 64 || b[0] >= 64) 1643 return 0; 1644 1645 /* truncated case */ 1646 if (a[0] == 0 && a - a0 == alen - 1) 1647 return 1; 1648 if (b[0] == 0 && b - b0 == blen - 1) 1649 return 1; 1650 if (a[0] == 0 || b[0] == 0) 1651 return 0; 1652 1653 if (a[0] != b[0]) 1654 return 0; 1655 l = a[0]; 1656 if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen) 1657 return 0; 1658 if (bcmp(a + 1, b + 1, l) != 0) 1659 return 0; 1660 1661 a += 1 + l; 1662 b += 1 + l; 1663 } 1664 1665 if (a - a0 == alen && b - b0 == blen) 1666 return 1; 1667 else 1668 return 0; 1669 } 1670 1671 /* 1672 * calculate the number of addresses to be returned in the node info reply. 1673 */ 1674 static int 1675 ni6_addrs(struct icmp6_nodeinfo *ni6, struct mbuf *m, struct ifnet **ifpp, 1676 struct in6_addr *subj) 1677 { 1678 struct ifnet *ifp; 1679 struct in6_ifaddr *ifa6; 1680 struct ifaddr *ifa; 1681 int addrs = 0, addrsofif, iffound = 0; 1682 int niflags = ni6->ni_flags; 1683 1684 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) { 1685 switch (ni6->ni_code) { 1686 case ICMP6_NI_SUBJ_IPV6: 1687 if (subj == NULL) /* must be impossible... */ 1688 return (0); 1689 break; 1690 default: 1691 /* 1692 * XXX: we only support IPv6 subject address for 1693 * this Qtype. 1694 */ 1695 return (0); 1696 } 1697 } 1698 1699 IFNET_RLOCK_NOSLEEP(); 1700 for (ifp = TAILQ_FIRST(&V_ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list)) { 1701 addrsofif = 0; 1702 IF_ADDR_LOCK(ifp); 1703 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 1704 if (ifa->ifa_addr->sa_family != AF_INET6) 1705 continue; 1706 ifa6 = (struct in6_ifaddr *)ifa; 1707 1708 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 && 1709 IN6_ARE_ADDR_EQUAL(subj, &ifa6->ia_addr.sin6_addr)) 1710 iffound = 1; 1711 1712 /* 1713 * IPv4-mapped addresses can only be returned by a 1714 * Node Information proxy, since they represent 1715 * addresses of IPv4-only nodes, which perforce do 1716 * not implement this protocol. 1717 * [icmp-name-lookups-07, Section 5.4] 1718 * So we don't support NI_NODEADDR_FLAG_COMPAT in 1719 * this function at this moment. 1720 */ 1721 1722 /* What do we have to do about ::1? */ 1723 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { 1724 case IPV6_ADDR_SCOPE_LINKLOCAL: 1725 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) 1726 continue; 1727 break; 1728 case IPV6_ADDR_SCOPE_SITELOCAL: 1729 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) 1730 continue; 1731 break; 1732 case IPV6_ADDR_SCOPE_GLOBAL: 1733 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) 1734 continue; 1735 break; 1736 default: 1737 continue; 1738 } 1739 1740 /* 1741 * check if anycast is okay. 1742 * XXX: just experimental. not in the spec. 1743 */ 1744 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && 1745 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) 1746 continue; /* we need only unicast addresses */ 1747 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && 1748 (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) { 1749 continue; 1750 } 1751 addrsofif++; /* count the address */ 1752 } 1753 IF_ADDR_UNLOCK(ifp); 1754 if (iffound) { 1755 *ifpp = ifp; 1756 IFNET_RUNLOCK_NOSLEEP(); 1757 return (addrsofif); 1758 } 1759 1760 addrs += addrsofif; 1761 } 1762 IFNET_RUNLOCK_NOSLEEP(); 1763 1764 return (addrs); 1765 } 1766 1767 static int 1768 ni6_store_addrs(struct icmp6_nodeinfo *ni6, struct icmp6_nodeinfo *nni6, 1769 struct ifnet *ifp0, int resid) 1770 { 1771 struct ifnet *ifp; 1772 struct in6_ifaddr *ifa6; 1773 struct ifaddr *ifa; 1774 struct ifnet *ifp_dep = NULL; 1775 int copied = 0, allow_deprecated = 0; 1776 u_char *cp = (u_char *)(nni6 + 1); 1777 int niflags = ni6->ni_flags; 1778 u_int32_t ltime; 1779 1780 if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL)) 1781 return (0); /* needless to copy */ 1782 1783 IFNET_RLOCK_NOSLEEP(); 1784 ifp = ifp0 ? ifp0 : TAILQ_FIRST(&V_ifnet); 1785 again: 1786 1787 for (; ifp; ifp = TAILQ_NEXT(ifp, if_list)) { 1788 IF_ADDR_LOCK(ifp); 1789 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 1790 if (ifa->ifa_addr->sa_family != AF_INET6) 1791 continue; 1792 ifa6 = (struct in6_ifaddr *)ifa; 1793 1794 if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 && 1795 allow_deprecated == 0) { 1796 /* 1797 * prefererred address should be put before 1798 * deprecated addresses. 1799 */ 1800 1801 /* record the interface for later search */ 1802 if (ifp_dep == NULL) 1803 ifp_dep = ifp; 1804 1805 continue; 1806 } else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 && 1807 allow_deprecated != 0) 1808 continue; /* we now collect deprecated addrs */ 1809 1810 /* What do we have to do about ::1? */ 1811 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { 1812 case IPV6_ADDR_SCOPE_LINKLOCAL: 1813 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) 1814 continue; 1815 break; 1816 case IPV6_ADDR_SCOPE_SITELOCAL: 1817 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) 1818 continue; 1819 break; 1820 case IPV6_ADDR_SCOPE_GLOBAL: 1821 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) 1822 continue; 1823 break; 1824 default: 1825 continue; 1826 } 1827 1828 /* 1829 * check if anycast is okay. 1830 * XXX: just experimental. not in the spec. 1831 */ 1832 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && 1833 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) 1834 continue; 1835 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && 1836 (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) { 1837 continue; 1838 } 1839 1840 /* now we can copy the address */ 1841 if (resid < sizeof(struct in6_addr) + 1842 sizeof(u_int32_t)) { 1843 IF_ADDR_UNLOCK(ifp); 1844 /* 1845 * We give up much more copy. 1846 * Set the truncate flag and return. 1847 */ 1848 nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE; 1849 IFNET_RUNLOCK_NOSLEEP(); 1850 return (copied); 1851 } 1852 1853 /* 1854 * Set the TTL of the address. 1855 * The TTL value should be one of the following 1856 * according to the specification: 1857 * 1858 * 1. The remaining lifetime of a DHCP lease on the 1859 * address, or 1860 * 2. The remaining Valid Lifetime of a prefix from 1861 * which the address was derived through Stateless 1862 * Autoconfiguration. 1863 * 1864 * Note that we currently do not support stateful 1865 * address configuration by DHCPv6, so the former 1866 * case can't happen. 1867 */ 1868 if (ifa6->ia6_lifetime.ia6t_expire == 0) 1869 ltime = ND6_INFINITE_LIFETIME; 1870 else { 1871 if (ifa6->ia6_lifetime.ia6t_expire > 1872 time_second) 1873 ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_second); 1874 else 1875 ltime = 0; 1876 } 1877 1878 bcopy(<ime, cp, sizeof(u_int32_t)); 1879 cp += sizeof(u_int32_t); 1880 1881 /* copy the address itself */ 1882 bcopy(&ifa6->ia_addr.sin6_addr, cp, 1883 sizeof(struct in6_addr)); 1884 in6_clearscope((struct in6_addr *)cp); /* XXX */ 1885 cp += sizeof(struct in6_addr); 1886 1887 resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t)); 1888 copied += (sizeof(struct in6_addr) + sizeof(u_int32_t)); 1889 } 1890 IF_ADDR_UNLOCK(ifp); 1891 if (ifp0) /* we need search only on the specified IF */ 1892 break; 1893 } 1894 1895 if (allow_deprecated == 0 && ifp_dep != NULL) { 1896 ifp = ifp_dep; 1897 allow_deprecated = 1; 1898 1899 goto again; 1900 } 1901 1902 IFNET_RUNLOCK_NOSLEEP(); 1903 1904 return (copied); 1905 } 1906 1907 /* 1908 * XXX almost dup'ed code with rip6_input. 1909 */ 1910 static int 1911 icmp6_rip6_input(struct mbuf **mp, int off) 1912 { 1913 struct mbuf *m = *mp; 1914 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1915 struct inpcb *in6p; 1916 struct inpcb *last = NULL; 1917 struct sockaddr_in6 fromsa; 1918 struct icmp6_hdr *icmp6; 1919 struct mbuf *opts = NULL; 1920 1921 #ifndef PULLDOWN_TEST 1922 /* this is assumed to be safe. */ 1923 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off); 1924 #else 1925 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6)); 1926 if (icmp6 == NULL) { 1927 /* m is already reclaimed */ 1928 return (IPPROTO_DONE); 1929 } 1930 #endif 1931 1932 /* 1933 * XXX: the address may have embedded scope zone ID, which should be 1934 * hidden from applications. 1935 */ 1936 bzero(&fromsa, sizeof(fromsa)); 1937 fromsa.sin6_family = AF_INET6; 1938 fromsa.sin6_len = sizeof(struct sockaddr_in6); 1939 fromsa.sin6_addr = ip6->ip6_src; 1940 if (sa6_recoverscope(&fromsa)) { 1941 m_freem(m); 1942 return (IPPROTO_DONE); 1943 } 1944 1945 INP_INFO_RLOCK(&V_ripcbinfo); 1946 LIST_FOREACH(in6p, &V_ripcb, inp_list) { 1947 if ((in6p->inp_vflag & INP_IPV6) == 0) 1948 continue; 1949 if (in6p->inp_ip_p != IPPROTO_ICMPV6) 1950 continue; 1951 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) && 1952 !IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &ip6->ip6_dst)) 1953 continue; 1954 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr) && 1955 !IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src)) 1956 continue; 1957 INP_RLOCK(in6p); 1958 if (ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type, 1959 in6p->in6p_icmp6filt)) { 1960 INP_RUNLOCK(in6p); 1961 continue; 1962 } 1963 if (last != NULL) { 1964 struct mbuf *n = NULL; 1965 1966 /* 1967 * Recent network drivers tend to allocate a single 1968 * mbuf cluster, rather than to make a couple of 1969 * mbufs without clusters. Also, since the IPv6 code 1970 * path tries to avoid m_pullup(), it is highly 1971 * probable that we still have an mbuf cluster here 1972 * even though the necessary length can be stored in an 1973 * mbuf's internal buffer. 1974 * Meanwhile, the default size of the receive socket 1975 * buffer for raw sockets is not so large. This means 1976 * the possibility of packet loss is relatively higher 1977 * than before. To avoid this scenario, we copy the 1978 * received data to a separate mbuf that does not use 1979 * a cluster, if possible. 1980 * XXX: it is better to copy the data after stripping 1981 * intermediate headers. 1982 */ 1983 if ((m->m_flags & M_EXT) && m->m_next == NULL && 1984 m->m_len <= MHLEN) { 1985 MGET(n, M_DONTWAIT, m->m_type); 1986 if (n != NULL) { 1987 if (m_dup_pkthdr(n, m, M_NOWAIT)) { 1988 bcopy(m->m_data, n->m_data, 1989 m->m_len); 1990 n->m_len = m->m_len; 1991 } else { 1992 m_free(n); 1993 n = NULL; 1994 } 1995 } 1996 } 1997 if (n != NULL || 1998 (n = m_copy(m, 0, (int)M_COPYALL)) != NULL) { 1999 if (last->inp_flags & INP_CONTROLOPTS) 2000 ip6_savecontrol(last, n, &opts); 2001 /* strip intermediate headers */ 2002 m_adj(n, off); 2003 SOCKBUF_LOCK(&last->inp_socket->so_rcv); 2004 if (sbappendaddr_locked( 2005 &last->inp_socket->so_rcv, 2006 (struct sockaddr *)&fromsa, n, opts) 2007 == 0) { 2008 /* should notify about lost packet */ 2009 m_freem(n); 2010 if (opts) { 2011 m_freem(opts); 2012 } 2013 SOCKBUF_UNLOCK( 2014 &last->inp_socket->so_rcv); 2015 } else 2016 sorwakeup_locked(last->inp_socket); 2017 opts = NULL; 2018 } 2019 INP_RUNLOCK(last); 2020 } 2021 last = in6p; 2022 } 2023 INP_INFO_RUNLOCK(&V_ripcbinfo); 2024 if (last != NULL) { 2025 if (last->inp_flags & INP_CONTROLOPTS) 2026 ip6_savecontrol(last, m, &opts); 2027 /* strip intermediate headers */ 2028 m_adj(m, off); 2029 2030 /* avoid using mbuf clusters if possible (see above) */ 2031 if ((m->m_flags & M_EXT) && m->m_next == NULL && 2032 m->m_len <= MHLEN) { 2033 struct mbuf *n; 2034 2035 MGET(n, M_DONTWAIT, m->m_type); 2036 if (n != NULL) { 2037 if (m_dup_pkthdr(n, m, M_NOWAIT)) { 2038 bcopy(m->m_data, n->m_data, m->m_len); 2039 n->m_len = m->m_len; 2040 2041 m_freem(m); 2042 m = n; 2043 } else { 2044 m_freem(n); 2045 n = NULL; 2046 } 2047 } 2048 } 2049 SOCKBUF_LOCK(&last->inp_socket->so_rcv); 2050 if (sbappendaddr_locked(&last->inp_socket->so_rcv, 2051 (struct sockaddr *)&fromsa, m, opts) == 0) { 2052 m_freem(m); 2053 if (opts) 2054 m_freem(opts); 2055 SOCKBUF_UNLOCK(&last->inp_socket->so_rcv); 2056 } else 2057 sorwakeup_locked(last->inp_socket); 2058 INP_RUNLOCK(last); 2059 } else { 2060 m_freem(m); 2061 IP6STAT_DEC(ip6s_delivered); 2062 } 2063 return IPPROTO_DONE; 2064 } 2065 2066 /* 2067 * Reflect the ip6 packet back to the source. 2068 * OFF points to the icmp6 header, counted from the top of the mbuf. 2069 */ 2070 void 2071 icmp6_reflect(struct mbuf *m, size_t off) 2072 { 2073 struct ip6_hdr *ip6; 2074 struct icmp6_hdr *icmp6; 2075 struct in6_ifaddr *ia = NULL; 2076 int plen; 2077 int type, code; 2078 struct ifnet *outif = NULL; 2079 struct in6_addr origdst, src, *srcp = NULL; 2080 2081 /* too short to reflect */ 2082 if (off < sizeof(struct ip6_hdr)) { 2083 nd6log((LOG_DEBUG, 2084 "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n", 2085 (u_long)off, (u_long)sizeof(struct ip6_hdr), 2086 __FILE__, __LINE__)); 2087 goto bad; 2088 } 2089 2090 /* 2091 * If there are extra headers between IPv6 and ICMPv6, strip 2092 * off that header first. 2093 */ 2094 #ifdef DIAGNOSTIC 2095 if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN) 2096 panic("assumption failed in icmp6_reflect"); 2097 #endif 2098 if (off > sizeof(struct ip6_hdr)) { 2099 size_t l; 2100 struct ip6_hdr nip6; 2101 2102 l = off - sizeof(struct ip6_hdr); 2103 m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6); 2104 m_adj(m, l); 2105 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 2106 if (m->m_len < l) { 2107 if ((m = m_pullup(m, l)) == NULL) 2108 return; 2109 } 2110 bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6)); 2111 } else /* off == sizeof(struct ip6_hdr) */ { 2112 size_t 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 } 2119 plen = m->m_pkthdr.len - sizeof(struct ip6_hdr); 2120 ip6 = mtod(m, struct ip6_hdr *); 2121 ip6->ip6_nxt = IPPROTO_ICMPV6; 2122 icmp6 = (struct icmp6_hdr *)(ip6 + 1); 2123 type = icmp6->icmp6_type; /* keep type for statistics */ 2124 code = icmp6->icmp6_code; /* ditto. */ 2125 2126 origdst = ip6->ip6_dst; 2127 /* 2128 * ip6_input() drops a packet if its src is multicast. 2129 * So, the src is never multicast. 2130 */ 2131 ip6->ip6_dst = ip6->ip6_src; 2132 2133 /* 2134 * If the incoming packet was addressed directly to us (i.e. unicast), 2135 * use dst as the src for the reply. 2136 * The IN6_IFF_NOTREADY case should be VERY rare, but is possible 2137 * (for example) when we encounter an error while forwarding procedure 2138 * destined to a duplicated address of ours. 2139 * Note that ip6_getdstifaddr() may fail if we are in an error handling 2140 * procedure of an outgoing packet of our own, in which case we need 2141 * to search in the ifaddr list. 2142 */ 2143 if (!IN6_IS_ADDR_MULTICAST(&origdst)) { 2144 if ((ia = ip6_getdstifaddr(m))) { 2145 if (!(ia->ia6_flags & 2146 (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) 2147 srcp = &ia->ia_addr.sin6_addr; 2148 } else { 2149 struct sockaddr_in6 d; 2150 2151 bzero(&d, sizeof(d)); 2152 d.sin6_family = AF_INET6; 2153 d.sin6_len = sizeof(d); 2154 d.sin6_addr = origdst; 2155 ia = (struct in6_ifaddr *) 2156 ifa_ifwithaddr((struct sockaddr *)&d); 2157 if (ia && 2158 !(ia->ia6_flags & 2159 (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) { 2160 srcp = &ia->ia_addr.sin6_addr; 2161 } 2162 } 2163 } 2164 2165 if (srcp == NULL) { 2166 int e; 2167 struct sockaddr_in6 sin6; 2168 struct route_in6 ro; 2169 2170 /* 2171 * This case matches to multicasts, our anycast, or unicasts 2172 * that we do not own. Select a source address based on the 2173 * source address of the erroneous packet. 2174 */ 2175 bzero(&sin6, sizeof(sin6)); 2176 sin6.sin6_family = AF_INET6; 2177 sin6.sin6_len = sizeof(sin6); 2178 sin6.sin6_addr = ip6->ip6_dst; /* zone ID should be embedded */ 2179 2180 bzero(&ro, sizeof(ro)); 2181 e = in6_selectsrc(&sin6, NULL, NULL, &ro, NULL, &outif, &src); 2182 if (ro.ro_rt) 2183 RTFREE(ro.ro_rt); /* XXX: we could use this */ 2184 if (e) { 2185 char ip6buf[INET6_ADDRSTRLEN]; 2186 nd6log((LOG_DEBUG, 2187 "icmp6_reflect: source can't be determined: " 2188 "dst=%s, error=%d\n", 2189 ip6_sprintf(ip6buf, &sin6.sin6_addr), e)); 2190 goto bad; 2191 } 2192 srcp = &src; 2193 } 2194 2195 ip6->ip6_src = *srcp; 2196 ip6->ip6_flow = 0; 2197 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2198 ip6->ip6_vfc |= IPV6_VERSION; 2199 ip6->ip6_nxt = IPPROTO_ICMPV6; 2200 if (outif) 2201 ip6->ip6_hlim = ND_IFINFO(outif)->chlim; 2202 else if (m->m_pkthdr.rcvif) { 2203 /* XXX: This may not be the outgoing interface */ 2204 ip6->ip6_hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim; 2205 } else 2206 ip6->ip6_hlim = V_ip6_defhlim; 2207 2208 icmp6->icmp6_cksum = 0; 2209 icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2210 sizeof(struct ip6_hdr), plen); 2211 2212 /* 2213 * XXX option handling 2214 */ 2215 2216 m->m_flags &= ~(M_BCAST|M_MCAST); 2217 2218 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2219 if (outif) 2220 icmp6_ifoutstat_inc(outif, type, code); 2221 2222 if (ia != NULL) 2223 ifa_free(&ia->ia_ifa); 2224 return; 2225 2226 bad: 2227 if (ia != NULL) 2228 ifa_free(&ia->ia_ifa); 2229 m_freem(m); 2230 return; 2231 } 2232 2233 void 2234 icmp6_fasttimo(void) 2235 { 2236 2237 mld_fasttimo(); 2238 } 2239 2240 void 2241 icmp6_slowtimo(void) 2242 { 2243 2244 mld_slowtimo(); 2245 } 2246 2247 static const char * 2248 icmp6_redirect_diag(struct in6_addr *src6, struct in6_addr *dst6, 2249 struct in6_addr *tgt6) 2250 { 2251 static char buf[1024]; 2252 char ip6bufs[INET6_ADDRSTRLEN]; 2253 char ip6bufd[INET6_ADDRSTRLEN]; 2254 char ip6buft[INET6_ADDRSTRLEN]; 2255 snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)", 2256 ip6_sprintf(ip6bufs, src6), ip6_sprintf(ip6bufd, dst6), 2257 ip6_sprintf(ip6buft, tgt6)); 2258 return buf; 2259 } 2260 2261 void 2262 icmp6_redirect_input(struct mbuf *m, int off) 2263 { 2264 struct ifnet *ifp; 2265 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 2266 struct nd_redirect *nd_rd; 2267 int icmp6len = ntohs(ip6->ip6_plen); 2268 char *lladdr = NULL; 2269 int lladdrlen = 0; 2270 struct rtentry *rt = NULL; 2271 int is_router; 2272 int is_onlink; 2273 struct in6_addr src6 = ip6->ip6_src; 2274 struct in6_addr redtgt6; 2275 struct in6_addr reddst6; 2276 union nd_opts ndopts; 2277 char ip6buf[INET6_ADDRSTRLEN]; 2278 2279 if (!m) 2280 return; 2281 2282 ifp = m->m_pkthdr.rcvif; 2283 2284 if (!ifp) 2285 return; 2286 2287 /* XXX if we are router, we don't update route by icmp6 redirect */ 2288 if (V_ip6_forwarding) 2289 goto freeit; 2290 if (!V_icmp6_rediraccept) 2291 goto freeit; 2292 2293 #ifndef PULLDOWN_TEST 2294 IP6_EXTHDR_CHECK(m, off, icmp6len,); 2295 nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off); 2296 #else 2297 IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len); 2298 if (nd_rd == NULL) { 2299 ICMP6STAT_INC(icp6s_tooshort); 2300 return; 2301 } 2302 #endif 2303 redtgt6 = nd_rd->nd_rd_target; 2304 reddst6 = nd_rd->nd_rd_dst; 2305 2306 if (in6_setscope(&redtgt6, m->m_pkthdr.rcvif, NULL) || 2307 in6_setscope(&reddst6, m->m_pkthdr.rcvif, NULL)) { 2308 goto freeit; 2309 } 2310 2311 /* validation */ 2312 if (!IN6_IS_ADDR_LINKLOCAL(&src6)) { 2313 nd6log((LOG_ERR, 2314 "ICMP6 redirect sent from %s rejected; " 2315 "must be from linklocal\n", 2316 ip6_sprintf(ip6buf, &src6))); 2317 goto bad; 2318 } 2319 if (ip6->ip6_hlim != 255) { 2320 nd6log((LOG_ERR, 2321 "ICMP6 redirect sent from %s rejected; " 2322 "hlim=%d (must be 255)\n", 2323 ip6_sprintf(ip6buf, &src6), ip6->ip6_hlim)); 2324 goto bad; 2325 } 2326 { 2327 /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */ 2328 struct sockaddr_in6 sin6; 2329 struct in6_addr *gw6; 2330 2331 bzero(&sin6, sizeof(sin6)); 2332 sin6.sin6_family = AF_INET6; 2333 sin6.sin6_len = sizeof(struct sockaddr_in6); 2334 bcopy(&reddst6, &sin6.sin6_addr, sizeof(reddst6)); 2335 rt = rtalloc1((struct sockaddr *)&sin6, 0, 0UL); 2336 if (rt) { 2337 if (rt->rt_gateway == NULL || 2338 rt->rt_gateway->sa_family != AF_INET6) { 2339 nd6log((LOG_ERR, 2340 "ICMP6 redirect rejected; no route " 2341 "with inet6 gateway found for redirect dst: %s\n", 2342 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2343 RTFREE_LOCKED(rt); 2344 goto bad; 2345 } 2346 2347 gw6 = &(((struct sockaddr_in6 *)rt->rt_gateway)->sin6_addr); 2348 if (bcmp(&src6, gw6, sizeof(struct in6_addr)) != 0) { 2349 nd6log((LOG_ERR, 2350 "ICMP6 redirect rejected; " 2351 "not equal to gw-for-src=%s (must be same): " 2352 "%s\n", 2353 ip6_sprintf(ip6buf, gw6), 2354 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2355 RTFREE_LOCKED(rt); 2356 goto bad; 2357 } 2358 } else { 2359 nd6log((LOG_ERR, 2360 "ICMP6 redirect rejected; " 2361 "no route found for redirect dst: %s\n", 2362 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2363 goto bad; 2364 } 2365 RTFREE_LOCKED(rt); 2366 rt = NULL; 2367 } 2368 if (IN6_IS_ADDR_MULTICAST(&reddst6)) { 2369 nd6log((LOG_ERR, 2370 "ICMP6 redirect rejected; " 2371 "redirect dst must be unicast: %s\n", 2372 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2373 goto bad; 2374 } 2375 2376 is_router = is_onlink = 0; 2377 if (IN6_IS_ADDR_LINKLOCAL(&redtgt6)) 2378 is_router = 1; /* router case */ 2379 if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0) 2380 is_onlink = 1; /* on-link destination case */ 2381 if (!is_router && !is_onlink) { 2382 nd6log((LOG_ERR, 2383 "ICMP6 redirect rejected; " 2384 "neither router case nor onlink case: %s\n", 2385 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2386 goto bad; 2387 } 2388 /* validation passed */ 2389 2390 icmp6len -= sizeof(*nd_rd); 2391 nd6_option_init(nd_rd + 1, icmp6len, &ndopts); 2392 if (nd6_options(&ndopts) < 0) { 2393 nd6log((LOG_INFO, "icmp6_redirect_input: " 2394 "invalid ND option, rejected: %s\n", 2395 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2396 /* nd6_options have incremented stats */ 2397 goto freeit; 2398 } 2399 2400 if (ndopts.nd_opts_tgt_lladdr) { 2401 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 2402 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 2403 } 2404 2405 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 2406 nd6log((LOG_INFO, 2407 "icmp6_redirect_input: lladdrlen mismatch for %s " 2408 "(if %d, icmp6 packet %d): %s\n", 2409 ip6_sprintf(ip6buf, &redtgt6), 2410 ifp->if_addrlen, lladdrlen - 2, 2411 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2412 goto bad; 2413 } 2414 2415 /* RFC 2461 8.3 */ 2416 nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT, 2417 is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER); 2418 2419 if (!is_onlink) { /* better router case. perform rtredirect. */ 2420 /* perform rtredirect */ 2421 struct sockaddr_in6 sdst; 2422 struct sockaddr_in6 sgw; 2423 struct sockaddr_in6 ssrc; 2424 2425 bzero(&sdst, sizeof(sdst)); 2426 bzero(&sgw, sizeof(sgw)); 2427 bzero(&ssrc, sizeof(ssrc)); 2428 sdst.sin6_family = sgw.sin6_family = ssrc.sin6_family = AF_INET6; 2429 sdst.sin6_len = sgw.sin6_len = ssrc.sin6_len = 2430 sizeof(struct sockaddr_in6); 2431 bcopy(&redtgt6, &sgw.sin6_addr, sizeof(struct in6_addr)); 2432 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr)); 2433 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr)); 2434 rtredirect((struct sockaddr *)&sdst, (struct sockaddr *)&sgw, 2435 (struct sockaddr *)NULL, RTF_GATEWAY | RTF_HOST, 2436 (struct sockaddr *)&ssrc); 2437 } 2438 /* finally update cached route in each socket via pfctlinput */ 2439 { 2440 struct sockaddr_in6 sdst; 2441 2442 bzero(&sdst, sizeof(sdst)); 2443 sdst.sin6_family = AF_INET6; 2444 sdst.sin6_len = sizeof(struct sockaddr_in6); 2445 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr)); 2446 pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst); 2447 #ifdef IPSEC 2448 key_sa_routechange((struct sockaddr *)&sdst); 2449 #endif /* IPSEC */ 2450 } 2451 2452 freeit: 2453 m_freem(m); 2454 return; 2455 2456 bad: 2457 ICMP6STAT_INC(icp6s_badredirect); 2458 m_freem(m); 2459 } 2460 2461 void 2462 icmp6_redirect_output(struct mbuf *m0, struct rtentry *rt) 2463 { 2464 struct ifnet *ifp; /* my outgoing interface */ 2465 struct in6_addr *ifp_ll6; 2466 struct in6_addr *router_ll6; 2467 struct ip6_hdr *sip6; /* m0 as struct ip6_hdr */ 2468 struct mbuf *m = NULL; /* newly allocated one */ 2469 struct ip6_hdr *ip6; /* m as struct ip6_hdr */ 2470 struct nd_redirect *nd_rd; 2471 struct llentry *ln = NULL; 2472 size_t maxlen; 2473 u_char *p; 2474 struct ifnet *outif = NULL; 2475 struct sockaddr_in6 src_sa; 2476 2477 icmp6_errcount(&V_icmp6stat.icp6s_outerrhist, ND_REDIRECT, 0); 2478 2479 /* if we are not router, we don't send icmp6 redirect */ 2480 if (!V_ip6_forwarding) 2481 goto fail; 2482 2483 /* sanity check */ 2484 if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp)) 2485 goto fail; 2486 2487 /* 2488 * Address check: 2489 * the source address must identify a neighbor, and 2490 * the destination address must not be a multicast address 2491 * [RFC 2461, sec 8.2] 2492 */ 2493 sip6 = mtod(m0, struct ip6_hdr *); 2494 bzero(&src_sa, sizeof(src_sa)); 2495 src_sa.sin6_family = AF_INET6; 2496 src_sa.sin6_len = sizeof(src_sa); 2497 src_sa.sin6_addr = sip6->ip6_src; 2498 if (nd6_is_addr_neighbor(&src_sa, ifp) == 0) 2499 goto fail; 2500 if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst)) 2501 goto fail; /* what should we do here? */ 2502 2503 /* rate limit */ 2504 if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0)) 2505 goto fail; 2506 2507 /* 2508 * Since we are going to append up to 1280 bytes (= IPV6_MMTU), 2509 * we almost always ask for an mbuf cluster for simplicity. 2510 * (MHLEN < IPV6_MMTU is almost always true) 2511 */ 2512 #if IPV6_MMTU >= MCLBYTES 2513 # error assumption failed about IPV6_MMTU and MCLBYTES 2514 #endif 2515 MGETHDR(m, M_DONTWAIT, MT_HEADER); 2516 if (m && IPV6_MMTU >= MHLEN) 2517 MCLGET(m, M_DONTWAIT); 2518 if (!m) 2519 goto fail; 2520 m->m_pkthdr.rcvif = NULL; 2521 m->m_len = 0; 2522 maxlen = M_TRAILINGSPACE(m); 2523 maxlen = min(IPV6_MMTU, maxlen); 2524 /* just for safety */ 2525 if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) + 2526 ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) { 2527 goto fail; 2528 } 2529 2530 { 2531 /* get ip6 linklocal address for ifp(my outgoing interface). */ 2532 struct in6_ifaddr *ia; 2533 if ((ia = in6ifa_ifpforlinklocal(ifp, 2534 IN6_IFF_NOTREADY| 2535 IN6_IFF_ANYCAST)) == NULL) 2536 goto fail; 2537 ifp_ll6 = &ia->ia_addr.sin6_addr; 2538 /* XXXRW: reference released prematurely. */ 2539 ifa_free(&ia->ia_ifa); 2540 } 2541 2542 /* get ip6 linklocal address for the router. */ 2543 if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) { 2544 struct sockaddr_in6 *sin6; 2545 sin6 = (struct sockaddr_in6 *)rt->rt_gateway; 2546 router_ll6 = &sin6->sin6_addr; 2547 if (!IN6_IS_ADDR_LINKLOCAL(router_ll6)) 2548 router_ll6 = (struct in6_addr *)NULL; 2549 } else 2550 router_ll6 = (struct in6_addr *)NULL; 2551 2552 /* ip6 */ 2553 ip6 = mtod(m, struct ip6_hdr *); 2554 ip6->ip6_flow = 0; 2555 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2556 ip6->ip6_vfc |= IPV6_VERSION; 2557 /* ip6->ip6_plen will be set later */ 2558 ip6->ip6_nxt = IPPROTO_ICMPV6; 2559 ip6->ip6_hlim = 255; 2560 /* ip6->ip6_src must be linklocal addr for my outgoing if. */ 2561 bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr)); 2562 bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr)); 2563 2564 /* ND Redirect */ 2565 nd_rd = (struct nd_redirect *)(ip6 + 1); 2566 nd_rd->nd_rd_type = ND_REDIRECT; 2567 nd_rd->nd_rd_code = 0; 2568 nd_rd->nd_rd_reserved = 0; 2569 if (rt->rt_flags & RTF_GATEWAY) { 2570 /* 2571 * nd_rd->nd_rd_target must be a link-local address in 2572 * better router cases. 2573 */ 2574 if (!router_ll6) 2575 goto fail; 2576 bcopy(router_ll6, &nd_rd->nd_rd_target, 2577 sizeof(nd_rd->nd_rd_target)); 2578 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2579 sizeof(nd_rd->nd_rd_dst)); 2580 } else { 2581 /* make sure redtgt == reddst */ 2582 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target, 2583 sizeof(nd_rd->nd_rd_target)); 2584 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2585 sizeof(nd_rd->nd_rd_dst)); 2586 } 2587 2588 p = (u_char *)(nd_rd + 1); 2589 2590 if (!router_ll6) 2591 goto nolladdropt; 2592 2593 { 2594 /* target lladdr option */ 2595 int len; 2596 struct nd_opt_hdr *nd_opt; 2597 char *lladdr; 2598 2599 IF_AFDATA_LOCK(ifp); 2600 ln = nd6_lookup(router_ll6, 0, ifp); 2601 IF_AFDATA_UNLOCK(ifp); 2602 if (ln == NULL) 2603 goto nolladdropt; 2604 2605 len = sizeof(*nd_opt) + ifp->if_addrlen; 2606 len = (len + 7) & ~7; /* round by 8 */ 2607 /* safety check */ 2608 if (len + (p - (u_char *)ip6) > maxlen) 2609 goto nolladdropt; 2610 2611 if (ln->la_flags & LLE_VALID) { 2612 nd_opt = (struct nd_opt_hdr *)p; 2613 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 2614 nd_opt->nd_opt_len = len >> 3; 2615 lladdr = (char *)(nd_opt + 1); 2616 bcopy(&ln->ll_addr, lladdr, ifp->if_addrlen); 2617 p += len; 2618 } 2619 } 2620 nolladdropt: 2621 if (ln != NULL) 2622 LLE_RUNLOCK(ln); 2623 2624 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2625 2626 /* just to be safe */ 2627 #ifdef M_DECRYPTED /*not openbsd*/ 2628 if (m0->m_flags & M_DECRYPTED) 2629 goto noredhdropt; 2630 #endif 2631 if (p - (u_char *)ip6 > maxlen) 2632 goto noredhdropt; 2633 2634 { 2635 /* redirected header option */ 2636 int len; 2637 struct nd_opt_rd_hdr *nd_opt_rh; 2638 2639 /* 2640 * compute the maximum size for icmp6 redirect header option. 2641 * XXX room for auth header? 2642 */ 2643 len = maxlen - (p - (u_char *)ip6); 2644 len &= ~7; 2645 2646 /* This is just for simplicity. */ 2647 if (m0->m_pkthdr.len != m0->m_len) { 2648 if (m0->m_next) { 2649 m_freem(m0->m_next); 2650 m0->m_next = NULL; 2651 } 2652 m0->m_pkthdr.len = m0->m_len; 2653 } 2654 2655 /* 2656 * Redirected header option spec (RFC2461 4.6.3) talks nothing 2657 * about padding/truncate rule for the original IP packet. 2658 * From the discussion on IPv6imp in Feb 1999, 2659 * the consensus was: 2660 * - "attach as much as possible" is the goal 2661 * - pad if not aligned (original size can be guessed by 2662 * original ip6 header) 2663 * Following code adds the padding if it is simple enough, 2664 * and truncates if not. 2665 */ 2666 if (m0->m_next || m0->m_pkthdr.len != m0->m_len) 2667 panic("assumption failed in %s:%d", __FILE__, 2668 __LINE__); 2669 2670 if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) { 2671 /* not enough room, truncate */ 2672 m0->m_pkthdr.len = m0->m_len = len - 2673 sizeof(*nd_opt_rh); 2674 } else { 2675 /* enough room, pad or truncate */ 2676 size_t extra; 2677 2678 extra = m0->m_pkthdr.len % 8; 2679 if (extra) { 2680 /* pad if easy enough, truncate if not */ 2681 if (8 - extra <= M_TRAILINGSPACE(m0)) { 2682 /* pad */ 2683 m0->m_len += (8 - extra); 2684 m0->m_pkthdr.len += (8 - extra); 2685 } else { 2686 /* truncate */ 2687 m0->m_pkthdr.len -= extra; 2688 m0->m_len -= extra; 2689 } 2690 } 2691 len = m0->m_pkthdr.len + sizeof(*nd_opt_rh); 2692 m0->m_pkthdr.len = m0->m_len = len - 2693 sizeof(*nd_opt_rh); 2694 } 2695 2696 nd_opt_rh = (struct nd_opt_rd_hdr *)p; 2697 bzero(nd_opt_rh, sizeof(*nd_opt_rh)); 2698 nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER; 2699 nd_opt_rh->nd_opt_rh_len = len >> 3; 2700 p += sizeof(*nd_opt_rh); 2701 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2702 2703 /* connect m0 to m */ 2704 m_tag_delete_chain(m0, NULL); 2705 m0->m_flags &= ~M_PKTHDR; 2706 m->m_next = m0; 2707 m->m_pkthdr.len = m->m_len + m0->m_len; 2708 m0 = NULL; 2709 } 2710 noredhdropt:; 2711 if (m0) { 2712 m_freem(m0); 2713 m0 = NULL; 2714 } 2715 2716 /* XXX: clear embedded link IDs in the inner header */ 2717 in6_clearscope(&sip6->ip6_src); 2718 in6_clearscope(&sip6->ip6_dst); 2719 in6_clearscope(&nd_rd->nd_rd_target); 2720 in6_clearscope(&nd_rd->nd_rd_dst); 2721 2722 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr)); 2723 2724 nd_rd->nd_rd_cksum = 0; 2725 nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2726 sizeof(*ip6), ntohs(ip6->ip6_plen)); 2727 2728 /* send the packet to outside... */ 2729 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2730 if (outif) { 2731 icmp6_ifstat_inc(outif, ifs6_out_msg); 2732 icmp6_ifstat_inc(outif, ifs6_out_redirect); 2733 } 2734 ICMP6STAT_INC(icp6s_outhist[ND_REDIRECT]); 2735 2736 return; 2737 2738 fail: 2739 if (m) 2740 m_freem(m); 2741 if (m0) 2742 m_freem(m0); 2743 } 2744 2745 /* 2746 * ICMPv6 socket option processing. 2747 */ 2748 int 2749 icmp6_ctloutput(struct socket *so, struct sockopt *sopt) 2750 { 2751 int error = 0; 2752 int optlen; 2753 struct inpcb *inp = sotoinpcb(so); 2754 int level, op, optname; 2755 2756 if (sopt) { 2757 level = sopt->sopt_level; 2758 op = sopt->sopt_dir; 2759 optname = sopt->sopt_name; 2760 optlen = sopt->sopt_valsize; 2761 } else 2762 level = op = optname = optlen = 0; 2763 2764 if (level != IPPROTO_ICMPV6) { 2765 return EINVAL; 2766 } 2767 2768 switch (op) { 2769 case PRCO_SETOPT: 2770 switch (optname) { 2771 case ICMP6_FILTER: 2772 { 2773 struct icmp6_filter ic6f; 2774 2775 if (optlen != sizeof(ic6f)) { 2776 error = EMSGSIZE; 2777 break; 2778 } 2779 error = sooptcopyin(sopt, &ic6f, optlen, optlen); 2780 if (error == 0) { 2781 INP_WLOCK(inp); 2782 *inp->in6p_icmp6filt = ic6f; 2783 INP_WUNLOCK(inp); 2784 } 2785 break; 2786 } 2787 2788 default: 2789 error = ENOPROTOOPT; 2790 break; 2791 } 2792 break; 2793 2794 case PRCO_GETOPT: 2795 switch (optname) { 2796 case ICMP6_FILTER: 2797 { 2798 struct icmp6_filter ic6f; 2799 2800 INP_RLOCK(inp); 2801 ic6f = *inp->in6p_icmp6filt; 2802 INP_RUNLOCK(inp); 2803 error = sooptcopyout(sopt, &ic6f, sizeof(ic6f)); 2804 break; 2805 } 2806 2807 default: 2808 error = ENOPROTOOPT; 2809 break; 2810 } 2811 break; 2812 } 2813 2814 return (error); 2815 } 2816 2817 /* 2818 * Perform rate limit check. 2819 * Returns 0 if it is okay to send the icmp6 packet. 2820 * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate 2821 * limitation. 2822 * 2823 * XXX per-destination/type check necessary? 2824 * 2825 * dst - not used at this moment 2826 * type - not used at this moment 2827 * code - not used at this moment 2828 */ 2829 static int 2830 icmp6_ratelimit(const struct in6_addr *dst, const int type, 2831 const int code) 2832 { 2833 int ret; 2834 2835 ret = 0; /* okay to send */ 2836 2837 /* PPS limit */ 2838 if (!ppsratecheck(&V_icmp6errppslim_last, &V_icmp6errpps_count, 2839 V_icmp6errppslim)) { 2840 /* The packet is subject to rate limit */ 2841 ret++; 2842 } 2843 2844 return ret; 2845 }
Cache object: 7b134af9f53dc17c88bf37b6035b8b34
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