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("$FreeBSD$"); 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 #include <netinet6/send.h> 109 110 #ifdef IPSEC 111 #include <netipsec/ipsec.h> 112 #include <netipsec/key.h> 113 #endif 114 115 extern struct domain inet6domain; 116 117 VNET_DEFINE(struct icmp6stat, icmp6stat); 118 119 VNET_DECLARE(struct inpcbinfo, ripcbinfo); 120 VNET_DECLARE(struct inpcbhead, ripcb); 121 VNET_DECLARE(int, icmp6errppslim); 122 static VNET_DEFINE(int, icmp6errpps_count) = 0; 123 static VNET_DEFINE(struct timeval, icmp6errppslim_last); 124 VNET_DECLARE(int, icmp6_nodeinfo); 125 126 #define V_ripcbinfo VNET(ripcbinfo) 127 #define V_ripcb VNET(ripcb) 128 #define V_icmp6errppslim VNET(icmp6errppslim) 129 #define V_icmp6errpps_count VNET(icmp6errpps_count) 130 #define V_icmp6errppslim_last VNET(icmp6errppslim_last) 131 #define V_icmp6_nodeinfo VNET(icmp6_nodeinfo) 132 133 static void icmp6_errcount(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(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(struct icmp6_nodeinfo *, struct mbuf *, 142 struct ifnet **, struct in6_addr *); 143 static int ni6_store_addrs(struct icmp6_nodeinfo *, struct icmp6_nodeinfo *, 144 struct ifnet *, int); 145 static int icmp6_notify_error(struct mbuf **, int, int, int); 146 147 /* 148 * Kernel module interface for updating icmp6stat. The argument is an index 149 * into icmp6stat treated as an array of u_quad_t. While this encodes the 150 * general layout of icmp6stat into the caller, it doesn't encode its 151 * location, so that future changes to add, for example, per-CPU stats 152 * support won't cause binary compatibility problems for kernel modules. 153 */ 154 void 155 kmod_icmp6stat_inc(int statnum) 156 { 157 158 (*((u_quad_t *)&V_icmp6stat + statnum))++; 159 } 160 161 static void 162 icmp6_errcount(int type, int code) 163 { 164 switch (type) { 165 case ICMP6_DST_UNREACH: 166 switch (code) { 167 case ICMP6_DST_UNREACH_NOROUTE: 168 ICMP6STAT_INC(icp6s_odst_unreach_noroute); 169 return; 170 case ICMP6_DST_UNREACH_ADMIN: 171 ICMP6STAT_INC(icp6s_odst_unreach_admin); 172 return; 173 case ICMP6_DST_UNREACH_BEYONDSCOPE: 174 ICMP6STAT_INC(icp6s_odst_unreach_beyondscope); 175 return; 176 case ICMP6_DST_UNREACH_ADDR: 177 ICMP6STAT_INC(icp6s_odst_unreach_addr); 178 return; 179 case ICMP6_DST_UNREACH_NOPORT: 180 ICMP6STAT_INC(icp6s_odst_unreach_noport); 181 return; 182 } 183 break; 184 case ICMP6_PACKET_TOO_BIG: 185 ICMP6STAT_INC(icp6s_opacket_too_big); 186 return; 187 case ICMP6_TIME_EXCEEDED: 188 switch (code) { 189 case ICMP6_TIME_EXCEED_TRANSIT: 190 ICMP6STAT_INC(icp6s_otime_exceed_transit); 191 return; 192 case ICMP6_TIME_EXCEED_REASSEMBLY: 193 ICMP6STAT_INC(icp6s_otime_exceed_reassembly); 194 return; 195 } 196 break; 197 case ICMP6_PARAM_PROB: 198 switch (code) { 199 case ICMP6_PARAMPROB_HEADER: 200 ICMP6STAT_INC(icp6s_oparamprob_header); 201 return; 202 case ICMP6_PARAMPROB_NEXTHEADER: 203 ICMP6STAT_INC(icp6s_oparamprob_nextheader); 204 return; 205 case ICMP6_PARAMPROB_OPTION: 206 ICMP6STAT_INC(icp6s_oparamprob_option); 207 return; 208 } 209 break; 210 case ND_REDIRECT: 211 ICMP6STAT_INC(icp6s_oredirect); 212 return; 213 } 214 ICMP6STAT_INC(icp6s_ounknown); 215 } 216 217 /* 218 * A wrapper function for icmp6_error() necessary when the erroneous packet 219 * may not contain enough scope zone information. 220 */ 221 void 222 icmp6_error2(struct mbuf *m, int type, int code, int param, 223 struct ifnet *ifp) 224 { 225 struct ip6_hdr *ip6; 226 227 if (ifp == NULL) 228 return; 229 230 #ifndef PULLDOWN_TEST 231 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), ); 232 #else 233 if (m->m_len < sizeof(struct ip6_hdr)) { 234 m = m_pullup(m, sizeof(struct ip6_hdr)); 235 if (m == NULL) 236 return; 237 } 238 #endif 239 240 ip6 = mtod(m, struct ip6_hdr *); 241 242 if (in6_setscope(&ip6->ip6_src, ifp, NULL) != 0) 243 return; 244 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0) 245 return; 246 247 icmp6_error(m, type, code, param); 248 } 249 250 /* 251 * Generate an error packet of type error in response to bad IP6 packet. 252 */ 253 void 254 icmp6_error(struct mbuf *m, int type, int code, int param) 255 { 256 struct ip6_hdr *oip6, *nip6; 257 struct icmp6_hdr *icmp6; 258 u_int preplen; 259 int off; 260 int nxt; 261 262 ICMP6STAT_INC(icp6s_error); 263 264 /* count per-type-code statistics */ 265 icmp6_errcount(type, code); 266 267 #ifdef M_DECRYPTED /*not openbsd*/ 268 if (m->m_flags & M_DECRYPTED) { 269 ICMP6STAT_INC(icp6s_canterror); 270 goto freeit; 271 } 272 #endif 273 274 #ifndef PULLDOWN_TEST 275 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), ); 276 #else 277 if (m->m_len < sizeof(struct ip6_hdr)) { 278 m = m_pullup(m, sizeof(struct ip6_hdr)); 279 if (m == NULL) 280 return; 281 } 282 #endif 283 oip6 = mtod(m, struct ip6_hdr *); 284 285 /* 286 * If the destination address of the erroneous packet is a multicast 287 * address, or the packet was sent using link-layer multicast, 288 * we should basically suppress sending an error (RFC 2463, Section 289 * 2.4). 290 * We have two exceptions (the item e.2 in that section): 291 * - the Packet Too Big message can be sent for path MTU discovery. 292 * - the Parameter Problem Message that can be allowed an icmp6 error 293 * in the option type field. This check has been done in 294 * ip6_unknown_opt(), so we can just check the type and code. 295 */ 296 if ((m->m_flags & (M_BCAST|M_MCAST) || 297 IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) && 298 (type != ICMP6_PACKET_TOO_BIG && 299 (type != ICMP6_PARAM_PROB || 300 code != ICMP6_PARAMPROB_OPTION))) 301 goto freeit; 302 303 /* 304 * RFC 2463, 2.4 (e.5): source address check. 305 * XXX: the case of anycast source? 306 */ 307 if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) || 308 IN6_IS_ADDR_MULTICAST(&oip6->ip6_src)) 309 goto freeit; 310 311 /* 312 * If we are about to send ICMPv6 against ICMPv6 error/redirect, 313 * don't do it. 314 */ 315 nxt = -1; 316 off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt); 317 if (off >= 0 && nxt == IPPROTO_ICMPV6) { 318 struct icmp6_hdr *icp; 319 320 #ifndef PULLDOWN_TEST 321 IP6_EXTHDR_CHECK(m, 0, off + sizeof(struct icmp6_hdr), ); 322 icp = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 323 #else 324 IP6_EXTHDR_GET(icp, struct icmp6_hdr *, m, off, 325 sizeof(*icp)); 326 if (icp == NULL) { 327 ICMP6STAT_INC(icp6s_tooshort); 328 return; 329 } 330 #endif 331 if (icp->icmp6_type < ICMP6_ECHO_REQUEST || 332 icp->icmp6_type == ND_REDIRECT) { 333 /* 334 * ICMPv6 error 335 * Special case: for redirect (which is 336 * informational) we must not send icmp6 error. 337 */ 338 ICMP6STAT_INC(icp6s_canterror); 339 goto freeit; 340 } else { 341 /* ICMPv6 informational - send the error */ 342 } 343 } else { 344 /* non-ICMPv6 - send the error */ 345 } 346 347 oip6 = mtod(m, struct ip6_hdr *); /* adjust pointer */ 348 349 /* Finally, do rate limitation check. */ 350 if (icmp6_ratelimit(&oip6->ip6_src, type, code)) { 351 ICMP6STAT_INC(icp6s_toofreq); 352 goto freeit; 353 } 354 355 /* 356 * OK, ICMP6 can be generated. 357 */ 358 359 if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN) 360 m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len); 361 362 preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 363 M_PREPEND(m, preplen, M_DONTWAIT); /* FIB is also copied over. */ 364 if (m == NULL) { 365 nd6log((LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__)); 366 return; 367 } 368 369 nip6 = mtod(m, struct ip6_hdr *); 370 nip6->ip6_src = oip6->ip6_src; 371 nip6->ip6_dst = oip6->ip6_dst; 372 373 in6_clearscope(&oip6->ip6_src); 374 in6_clearscope(&oip6->ip6_dst); 375 376 icmp6 = (struct icmp6_hdr *)(nip6 + 1); 377 icmp6->icmp6_type = type; 378 icmp6->icmp6_code = code; 379 icmp6->icmp6_pptr = htonl((u_int32_t)param); 380 381 /* 382 * icmp6_reflect() is designed to be in the input path. 383 * icmp6_error() can be called from both input and output path, 384 * and if we are in output path rcvif could contain bogus value. 385 * clear m->m_pkthdr.rcvif for safety, we should have enough scope 386 * information in ip header (nip6). 387 */ 388 m->m_pkthdr.rcvif = NULL; 389 390 ICMP6STAT_INC(icp6s_outhist[type]); 391 icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */ 392 393 return; 394 395 freeit: 396 /* 397 * If we can't tell whether or not we can generate ICMP6, free it. 398 */ 399 m_freem(m); 400 } 401 402 /* 403 * Process a received ICMP6 message. 404 */ 405 int 406 icmp6_input(struct mbuf **mp, int *offp, int proto) 407 { 408 struct mbuf *m = *mp, *n; 409 struct ifnet *ifp; 410 struct ip6_hdr *ip6, *nip6; 411 struct icmp6_hdr *icmp6, *nicmp6; 412 int off = *offp; 413 int icmp6len = m->m_pkthdr.len - *offp; 414 int code, sum, noff; 415 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 416 int ip6len, error; 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 ip6len = sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen); 432 if (icmp6len < sizeof(struct icmp6_hdr)) { 433 ICMP6STAT_INC(icp6s_tooshort); 434 goto freeit; 435 } 436 437 /* 438 * Check multicast group membership. 439 * Note: SSM filters are not applied for ICMPv6 traffic. 440 */ 441 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 442 struct in6_multi *inm; 443 444 inm = in6m_lookup(ifp, &ip6->ip6_dst); 445 if (inm == NULL) { 446 IP6STAT_INC(ip6s_notmember); 447 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 448 goto freeit; 449 } 450 } 451 452 /* 453 * calculate the checksum 454 */ 455 #ifndef PULLDOWN_TEST 456 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off); 457 #else 458 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6)); 459 if (icmp6 == NULL) { 460 ICMP6STAT_INC(icp6s_tooshort); 461 return IPPROTO_DONE; 462 } 463 #endif 464 code = icmp6->icmp6_code; 465 466 if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) { 467 nd6log((LOG_ERR, 468 "ICMP6 checksum error(%d|%x) %s\n", 469 icmp6->icmp6_type, sum, 470 ip6_sprintf(ip6bufs, &ip6->ip6_src))); 471 ICMP6STAT_INC(icp6s_checksum); 472 goto freeit; 473 } 474 475 if (faithprefix_p != NULL && (*faithprefix_p)(&ip6->ip6_dst)) { 476 /* 477 * Deliver very specific ICMP6 type only. 478 * This is important to deliver TOOBIG. Otherwise PMTUD 479 * will not work. 480 */ 481 switch (icmp6->icmp6_type) { 482 case ICMP6_DST_UNREACH: 483 case ICMP6_PACKET_TOO_BIG: 484 case ICMP6_TIME_EXCEEDED: 485 break; 486 default: 487 goto freeit; 488 } 489 } 490 491 ICMP6STAT_INC(icp6s_inhist[icmp6->icmp6_type]); 492 icmp6_ifstat_inc(ifp, ifs6_in_msg); 493 if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK) 494 icmp6_ifstat_inc(ifp, ifs6_in_error); 495 496 switch (icmp6->icmp6_type) { 497 case ICMP6_DST_UNREACH: 498 icmp6_ifstat_inc(ifp, ifs6_in_dstunreach); 499 switch (code) { 500 case ICMP6_DST_UNREACH_NOROUTE: 501 code = PRC_UNREACH_NET; 502 break; 503 case ICMP6_DST_UNREACH_ADMIN: 504 icmp6_ifstat_inc(ifp, ifs6_in_adminprohib); 505 code = PRC_UNREACH_PROTOCOL; /* is this a good code? */ 506 break; 507 case ICMP6_DST_UNREACH_ADDR: 508 code = PRC_HOSTDEAD; 509 break; 510 case ICMP6_DST_UNREACH_BEYONDSCOPE: 511 /* I mean "source address was incorrect." */ 512 code = PRC_PARAMPROB; 513 break; 514 case ICMP6_DST_UNREACH_NOPORT: 515 code = PRC_UNREACH_PORT; 516 break; 517 default: 518 goto badcode; 519 } 520 goto deliver; 521 break; 522 523 case ICMP6_PACKET_TOO_BIG: 524 icmp6_ifstat_inc(ifp, ifs6_in_pkttoobig); 525 526 /* validation is made in icmp6_mtudisc_update */ 527 528 code = PRC_MSGSIZE; 529 530 /* 531 * Updating the path MTU will be done after examining 532 * intermediate extension headers. 533 */ 534 goto deliver; 535 break; 536 537 case ICMP6_TIME_EXCEEDED: 538 icmp6_ifstat_inc(ifp, ifs6_in_timeexceed); 539 switch (code) { 540 case ICMP6_TIME_EXCEED_TRANSIT: 541 code = PRC_TIMXCEED_INTRANS; 542 break; 543 case ICMP6_TIME_EXCEED_REASSEMBLY: 544 code = PRC_TIMXCEED_REASS; 545 break; 546 default: 547 goto badcode; 548 } 549 goto deliver; 550 break; 551 552 case ICMP6_PARAM_PROB: 553 icmp6_ifstat_inc(ifp, ifs6_in_paramprob); 554 switch (code) { 555 case ICMP6_PARAMPROB_NEXTHEADER: 556 code = PRC_UNREACH_PROTOCOL; 557 break; 558 case ICMP6_PARAMPROB_HEADER: 559 case ICMP6_PARAMPROB_OPTION: 560 code = PRC_PARAMPROB; 561 break; 562 default: 563 goto badcode; 564 } 565 goto deliver; 566 break; 567 568 case ICMP6_ECHO_REQUEST: 569 icmp6_ifstat_inc(ifp, ifs6_in_echo); 570 if (code != 0) 571 goto badcode; 572 if ((n = m_copy(m, 0, M_COPYALL)) == NULL) { 573 /* Give up remote */ 574 break; 575 } 576 if ((n->m_flags & M_EXT) != 0 577 || n->m_len < off + sizeof(struct icmp6_hdr)) { 578 struct mbuf *n0 = n; 579 const int maxlen = sizeof(*nip6) + sizeof(*nicmp6); 580 int n0len; 581 582 MGETHDR(n, M_DONTWAIT, n0->m_type); 583 n0len = n0->m_pkthdr.len; /* save for use below */ 584 if (n) 585 M_MOVE_PKTHDR(n, n0); /* FIB copied. */ 586 if (n && maxlen >= MHLEN) { 587 MCLGET(n, M_DONTWAIT); 588 if ((n->m_flags & M_EXT) == 0) { 589 m_free(n); 590 n = NULL; 591 } 592 } 593 if (n == NULL) { 594 /* Give up remote */ 595 m_freem(n0); 596 break; 597 } 598 /* 599 * Copy IPv6 and ICMPv6 only. 600 */ 601 nip6 = mtod(n, struct ip6_hdr *); 602 bcopy(ip6, nip6, sizeof(struct ip6_hdr)); 603 nicmp6 = (struct icmp6_hdr *)(nip6 + 1); 604 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr)); 605 noff = sizeof(struct ip6_hdr); 606 /* new mbuf contains only ipv6+icmpv6 headers */ 607 n->m_len = noff + sizeof(struct icmp6_hdr); 608 /* 609 * Adjust mbuf. ip6_plen will be adjusted in 610 * ip6_output(). 611 */ 612 m_adj(n0, off + sizeof(struct icmp6_hdr)); 613 /* recalculate complete packet size */ 614 n->m_pkthdr.len = n0len + (noff - off); 615 n->m_next = n0; 616 } else { 617 nip6 = mtod(n, struct ip6_hdr *); 618 IP6_EXTHDR_GET(nicmp6, struct icmp6_hdr *, n, off, 619 sizeof(*nicmp6)); 620 noff = off; 621 } 622 nicmp6->icmp6_type = ICMP6_ECHO_REPLY; 623 nicmp6->icmp6_code = 0; 624 if (n) { 625 ICMP6STAT_INC(icp6s_reflect); 626 ICMP6STAT_INC(icp6s_outhist[ICMP6_ECHO_REPLY]); 627 icmp6_reflect(n, noff); 628 } 629 break; 630 631 case ICMP6_ECHO_REPLY: 632 icmp6_ifstat_inc(ifp, ifs6_in_echoreply); 633 if (code != 0) 634 goto badcode; 635 break; 636 637 case MLD_LISTENER_QUERY: 638 case MLD_LISTENER_REPORT: 639 case MLD_LISTENER_DONE: 640 case MLDV2_LISTENER_REPORT: 641 /* 642 * Drop MLD traffic which is not link-local, has a hop limit 643 * of greater than 1 hop, or which does not have the 644 * IPv6 HBH Router Alert option. 645 * As IPv6 HBH options are stripped in ip6_input() we must 646 * check an mbuf header flag. 647 * XXX Should we also sanity check that these messages 648 * were directed to a link-local multicast prefix? 649 */ 650 if ((ip6->ip6_hlim != 1) || (m->m_flags & M_RTALERT_MLD) == 0) 651 goto freeit; 652 if (mld_input(m, off, icmp6len) != 0) 653 return (IPPROTO_DONE); 654 /* m stays. */ 655 break; 656 657 case ICMP6_WRUREQUEST: /* ICMP6_FQDN_QUERY */ 658 { 659 enum { WRU, FQDN } mode; 660 661 if (!V_icmp6_nodeinfo) 662 break; 663 664 if (icmp6len == sizeof(struct icmp6_hdr) + 4) 665 mode = WRU; 666 else if (icmp6len >= sizeof(struct icmp6_nodeinfo)) 667 mode = FQDN; 668 else 669 goto badlen; 670 671 if (mode == FQDN) { 672 #ifndef PULLDOWN_TEST 673 IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_nodeinfo), 674 IPPROTO_DONE); 675 #endif 676 n = m_copy(m, 0, M_COPYALL); 677 if (n) 678 n = ni6_input(n, off); 679 /* XXX meaningless if n == NULL */ 680 noff = sizeof(struct ip6_hdr); 681 } else { 682 struct prison *pr; 683 u_char *p; 684 int maxlen, maxhlen, hlen; 685 686 /* 687 * XXX: this combination of flags is pointless, 688 * but should we keep this for compatibility? 689 */ 690 if ((V_icmp6_nodeinfo & 5) != 5) 691 break; 692 693 if (code != 0) 694 goto badcode; 695 maxlen = sizeof(*nip6) + sizeof(*nicmp6) + 4; 696 if (maxlen >= MCLBYTES) { 697 /* Give up remote */ 698 break; 699 } 700 MGETHDR(n, M_DONTWAIT, m->m_type); 701 if (n && maxlen > MHLEN) { 702 MCLGET(n, M_DONTWAIT); 703 if ((n->m_flags & M_EXT) == 0) { 704 m_free(n); 705 n = NULL; 706 } 707 } 708 if (n && !m_dup_pkthdr(n, m, M_DONTWAIT)) { 709 /* 710 * Previous code did a blind M_COPY_PKTHDR 711 * and said "just for rcvif". If true, then 712 * we could tolerate the dup failing (due to 713 * the deep copy of the tag chain). For now 714 * be conservative and just fail. 715 */ 716 m_free(n); 717 n = NULL; 718 } 719 if (n == NULL) { 720 /* Give up remote */ 721 break; 722 } 723 n->m_pkthdr.rcvif = NULL; 724 n->m_len = 0; 725 maxhlen = M_TRAILINGSPACE(n) - maxlen; 726 pr = curthread->td_ucred->cr_prison; 727 mtx_lock(&pr->pr_mtx); 728 hlen = strlen(pr->pr_hostname); 729 if (maxhlen > hlen) 730 maxhlen = hlen; 731 /* 732 * Copy IPv6 and ICMPv6 only. 733 */ 734 nip6 = mtod(n, struct ip6_hdr *); 735 bcopy(ip6, nip6, sizeof(struct ip6_hdr)); 736 nicmp6 = (struct icmp6_hdr *)(nip6 + 1); 737 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr)); 738 p = (u_char *)(nicmp6 + 1); 739 bzero(p, 4); 740 /* meaningless TTL */ 741 bcopy(pr->pr_hostname, p + 4, maxhlen); 742 mtx_unlock(&pr->pr_mtx); 743 noff = sizeof(struct ip6_hdr); 744 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + 745 sizeof(struct icmp6_hdr) + 4 + maxhlen; 746 nicmp6->icmp6_type = ICMP6_WRUREPLY; 747 nicmp6->icmp6_code = 0; 748 } 749 if (n) { 750 ICMP6STAT_INC(icp6s_reflect); 751 ICMP6STAT_INC(icp6s_outhist[ICMP6_WRUREPLY]); 752 icmp6_reflect(n, noff); 753 } 754 break; 755 } 756 757 case ICMP6_WRUREPLY: 758 if (code != 0) 759 goto badcode; 760 break; 761 762 case ND_ROUTER_SOLICIT: 763 icmp6_ifstat_inc(ifp, ifs6_in_routersolicit); 764 if (code != 0) 765 goto badcode; 766 if (icmp6len < sizeof(struct nd_router_solicit)) 767 goto badlen; 768 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 769 /* give up local */ 770 771 /* Send incoming SeND packet to user space. */ 772 if (send_sendso_input_hook != NULL) { 773 IP6_EXTHDR_CHECK(m, off, 774 icmp6len, IPPROTO_DONE); 775 error = send_sendso_input_hook(m, ifp, 776 SND_IN, ip6len); 777 /* -1 == no app on SEND socket */ 778 if (error == 0) 779 return (IPPROTO_DONE); 780 nd6_rs_input(m, off, icmp6len); 781 } else 782 nd6_rs_input(m, off, icmp6len); 783 m = NULL; 784 goto freeit; 785 } 786 if (send_sendso_input_hook != NULL) { 787 IP6_EXTHDR_CHECK(n, off, 788 icmp6len, IPPROTO_DONE); 789 error = send_sendso_input_hook(n, ifp, 790 SND_IN, ip6len); 791 if (error == 0) 792 goto freeit; 793 /* -1 == no app on SEND socket */ 794 nd6_rs_input(n, off, icmp6len); 795 } else 796 nd6_rs_input(n, off, icmp6len); 797 /* m stays. */ 798 break; 799 800 case ND_ROUTER_ADVERT: 801 icmp6_ifstat_inc(ifp, ifs6_in_routeradvert); 802 if (code != 0) 803 goto badcode; 804 if (icmp6len < sizeof(struct nd_router_advert)) 805 goto badlen; 806 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 807 808 /* Send incoming SeND-protected/ND packet to user space. */ 809 if (send_sendso_input_hook != NULL) { 810 error = send_sendso_input_hook(m, ifp, 811 SND_IN, ip6len); 812 if (error == 0) 813 return (IPPROTO_DONE); 814 nd6_ra_input(m, off, icmp6len); 815 } else 816 nd6_ra_input(m, off, icmp6len); 817 m = NULL; 818 goto freeit; 819 } 820 if (send_sendso_input_hook != NULL) { 821 error = send_sendso_input_hook(n, ifp, 822 SND_IN, ip6len); 823 if (error == 0) 824 goto freeit; 825 nd6_ra_input(n, off, icmp6len); 826 } else 827 nd6_ra_input(n, off, icmp6len); 828 /* m stays. */ 829 break; 830 831 case ND_NEIGHBOR_SOLICIT: 832 icmp6_ifstat_inc(ifp, ifs6_in_neighborsolicit); 833 if (code != 0) 834 goto badcode; 835 if (icmp6len < sizeof(struct nd_neighbor_solicit)) 836 goto badlen; 837 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 838 if (send_sendso_input_hook != NULL) { 839 error = send_sendso_input_hook(m, ifp, 840 SND_IN, ip6len); 841 if (error == 0) 842 return (IPPROTO_DONE); 843 nd6_ns_input(m, off, icmp6len); 844 } else 845 nd6_ns_input(m, off, icmp6len); 846 m = NULL; 847 goto freeit; 848 } 849 if (send_sendso_input_hook != NULL) { 850 error = send_sendso_input_hook(n, ifp, 851 SND_IN, ip6len); 852 if (error == 0) 853 goto freeit; 854 nd6_ns_input(n, off, icmp6len); 855 } else 856 nd6_ns_input(n, off, icmp6len); 857 /* m stays. */ 858 break; 859 860 case ND_NEIGHBOR_ADVERT: 861 icmp6_ifstat_inc(ifp, ifs6_in_neighboradvert); 862 if (code != 0) 863 goto badcode; 864 if (icmp6len < sizeof(struct nd_neighbor_advert)) 865 goto badlen; 866 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 867 868 /* Send incoming SeND-protected/ND packet to user space. */ 869 if (send_sendso_input_hook != NULL) { 870 error = send_sendso_input_hook(m, ifp, 871 SND_IN, ip6len); 872 if (error == 0) 873 return (IPPROTO_DONE); 874 nd6_na_input(m, off, icmp6len); 875 } else 876 nd6_na_input(m, off, icmp6len); 877 m = NULL; 878 goto freeit; 879 } 880 if (send_sendso_input_hook != NULL) { 881 error = send_sendso_input_hook(n, ifp, 882 SND_IN, ip6len); 883 if (error == 0) 884 goto freeit; 885 nd6_na_input(n, off, icmp6len); 886 } else 887 nd6_na_input(n, off, icmp6len); 888 /* m stays. */ 889 break; 890 891 case ND_REDIRECT: 892 icmp6_ifstat_inc(ifp, ifs6_in_redirect); 893 if (code != 0) 894 goto badcode; 895 if (icmp6len < sizeof(struct nd_redirect)) 896 goto badlen; 897 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 898 if (send_sendso_input_hook != NULL) { 899 error = send_sendso_input_hook(m, ifp, 900 SND_IN, ip6len); 901 if (error == 0) 902 return (IPPROTO_DONE); 903 icmp6_redirect_input(m, off); 904 } else 905 icmp6_redirect_input(m, off); 906 m = NULL; 907 goto freeit; 908 } 909 if (send_sendso_input_hook != NULL) { 910 error = send_sendso_input_hook(n, ifp, 911 SND_IN, ip6len); 912 if (error == 0) 913 goto freeit; 914 icmp6_redirect_input(n, off); 915 } else 916 icmp6_redirect_input(n, off); 917 /* m stays. */ 918 break; 919 920 case ICMP6_ROUTER_RENUMBERING: 921 if (code != ICMP6_ROUTER_RENUMBERING_COMMAND && 922 code != ICMP6_ROUTER_RENUMBERING_RESULT) 923 goto badcode; 924 if (icmp6len < sizeof(struct icmp6_router_renum)) 925 goto badlen; 926 break; 927 928 default: 929 nd6log((LOG_DEBUG, 930 "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n", 931 icmp6->icmp6_type, ip6_sprintf(ip6bufs, &ip6->ip6_src), 932 ip6_sprintf(ip6bufd, &ip6->ip6_dst), 933 ifp ? ifp->if_index : 0)); 934 if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) { 935 /* ICMPv6 error: MUST deliver it by spec... */ 936 code = PRC_NCMDS; 937 /* deliver */ 938 } else { 939 /* ICMPv6 informational: MUST not deliver */ 940 break; 941 } 942 deliver: 943 if (icmp6_notify_error(&m, off, icmp6len, code) != 0) { 944 /* In this case, m should've been freed. */ 945 return (IPPROTO_DONE); 946 } 947 break; 948 949 badcode: 950 ICMP6STAT_INC(icp6s_badcode); 951 break; 952 953 badlen: 954 ICMP6STAT_INC(icp6s_badlen); 955 break; 956 } 957 958 /* deliver the packet to appropriate sockets */ 959 icmp6_rip6_input(&m, *offp); 960 961 return IPPROTO_DONE; 962 963 freeit: 964 m_freem(m); 965 return IPPROTO_DONE; 966 } 967 968 static int 969 icmp6_notify_error(struct mbuf **mp, int off, int icmp6len, int code) 970 { 971 struct mbuf *m = *mp; 972 struct icmp6_hdr *icmp6; 973 struct ip6_hdr *eip6; 974 u_int32_t notifymtu; 975 struct sockaddr_in6 icmp6src, icmp6dst; 976 977 if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) { 978 ICMP6STAT_INC(icp6s_tooshort); 979 goto freeit; 980 } 981 #ifndef PULLDOWN_TEST 982 IP6_EXTHDR_CHECK(m, off, 983 sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr), -1); 984 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 985 #else 986 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, 987 sizeof(*icmp6) + sizeof(struct ip6_hdr)); 988 if (icmp6 == NULL) { 989 ICMP6STAT_INC(icp6s_tooshort); 990 return (-1); 991 } 992 #endif 993 eip6 = (struct ip6_hdr *)(icmp6 + 1); 994 995 /* Detect the upper level protocol */ 996 { 997 void (*ctlfunc)(int, struct sockaddr *, void *); 998 u_int8_t nxt = eip6->ip6_nxt; 999 int eoff = off + sizeof(struct icmp6_hdr) + 1000 sizeof(struct ip6_hdr); 1001 struct ip6ctlparam ip6cp; 1002 struct in6_addr *finaldst = NULL; 1003 int icmp6type = icmp6->icmp6_type; 1004 struct ip6_frag *fh; 1005 struct ip6_rthdr *rth; 1006 struct ip6_rthdr0 *rth0; 1007 int rthlen; 1008 1009 while (1) { /* XXX: should avoid infinite loop explicitly? */ 1010 struct ip6_ext *eh; 1011 1012 switch (nxt) { 1013 case IPPROTO_HOPOPTS: 1014 case IPPROTO_DSTOPTS: 1015 case IPPROTO_AH: 1016 #ifndef PULLDOWN_TEST 1017 IP6_EXTHDR_CHECK(m, 0, 1018 eoff + sizeof(struct ip6_ext), -1); 1019 eh = (struct ip6_ext *)(mtod(m, caddr_t) + eoff); 1020 #else 1021 IP6_EXTHDR_GET(eh, struct ip6_ext *, m, 1022 eoff, sizeof(*eh)); 1023 if (eh == NULL) { 1024 ICMP6STAT_INC(icp6s_tooshort); 1025 return (-1); 1026 } 1027 #endif 1028 1029 if (nxt == IPPROTO_AH) 1030 eoff += (eh->ip6e_len + 2) << 2; 1031 else 1032 eoff += (eh->ip6e_len + 1) << 3; 1033 nxt = eh->ip6e_nxt; 1034 break; 1035 case IPPROTO_ROUTING: 1036 /* 1037 * When the erroneous packet contains a 1038 * routing header, we should examine the 1039 * header to determine the final destination. 1040 * Otherwise, we can't properly update 1041 * information that depends on the final 1042 * destination (e.g. path MTU). 1043 */ 1044 #ifndef PULLDOWN_TEST 1045 IP6_EXTHDR_CHECK(m, 0, eoff + sizeof(*rth), -1); 1046 rth = (struct ip6_rthdr *) 1047 (mtod(m, caddr_t) + eoff); 1048 #else 1049 IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m, 1050 eoff, sizeof(*rth)); 1051 if (rth == NULL) { 1052 ICMP6STAT_INC(icp6s_tooshort); 1053 return (-1); 1054 } 1055 #endif 1056 rthlen = (rth->ip6r_len + 1) << 3; 1057 /* 1058 * XXX: currently there is no 1059 * officially defined type other 1060 * than type-0. 1061 * Note that if the segment left field 1062 * is 0, all intermediate hops must 1063 * have been passed. 1064 */ 1065 if (rth->ip6r_segleft && 1066 rth->ip6r_type == IPV6_RTHDR_TYPE_0) { 1067 int hops; 1068 1069 #ifndef PULLDOWN_TEST 1070 IP6_EXTHDR_CHECK(m, 0, eoff + rthlen, -1); 1071 rth0 = (struct ip6_rthdr0 *) 1072 (mtod(m, caddr_t) + eoff); 1073 #else 1074 IP6_EXTHDR_GET(rth0, 1075 struct ip6_rthdr0 *, m, 1076 eoff, rthlen); 1077 if (rth0 == NULL) { 1078 ICMP6STAT_INC(icp6s_tooshort); 1079 return (-1); 1080 } 1081 #endif 1082 /* just ignore a bogus header */ 1083 if ((rth0->ip6r0_len % 2) == 0 && 1084 (hops = rth0->ip6r0_len/2)) 1085 finaldst = (struct in6_addr *)(rth0 + 1) + (hops - 1); 1086 } 1087 eoff += rthlen; 1088 nxt = rth->ip6r_nxt; 1089 break; 1090 case IPPROTO_FRAGMENT: 1091 #ifndef PULLDOWN_TEST 1092 IP6_EXTHDR_CHECK(m, 0, eoff + 1093 sizeof(struct ip6_frag), -1); 1094 fh = (struct ip6_frag *)(mtod(m, caddr_t) + 1095 eoff); 1096 #else 1097 IP6_EXTHDR_GET(fh, struct ip6_frag *, m, 1098 eoff, sizeof(*fh)); 1099 if (fh == NULL) { 1100 ICMP6STAT_INC(icp6s_tooshort); 1101 return (-1); 1102 } 1103 #endif 1104 /* 1105 * Data after a fragment header is meaningless 1106 * unless it is the first fragment, but 1107 * we'll go to the notify label for path MTU 1108 * discovery. 1109 */ 1110 if (fh->ip6f_offlg & IP6F_OFF_MASK) 1111 goto notify; 1112 1113 eoff += sizeof(struct ip6_frag); 1114 nxt = fh->ip6f_nxt; 1115 break; 1116 default: 1117 /* 1118 * This case includes ESP and the No Next 1119 * Header. In such cases going to the notify 1120 * label does not have any meaning 1121 * (i.e. ctlfunc will be NULL), but we go 1122 * anyway since we might have to update 1123 * path MTU information. 1124 */ 1125 goto notify; 1126 } 1127 } 1128 notify: 1129 #ifndef PULLDOWN_TEST 1130 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 1131 #else 1132 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, 1133 sizeof(*icmp6) + sizeof(struct ip6_hdr)); 1134 if (icmp6 == NULL) { 1135 ICMP6STAT_INC(icp6s_tooshort); 1136 return (-1); 1137 } 1138 #endif 1139 1140 /* 1141 * retrieve parameters from the inner IPv6 header, and convert 1142 * them into sockaddr structures. 1143 * XXX: there is no guarantee that the source or destination 1144 * addresses of the inner packet are in the same scope as 1145 * the addresses of the icmp packet. But there is no other 1146 * way to determine the zone. 1147 */ 1148 eip6 = (struct ip6_hdr *)(icmp6 + 1); 1149 1150 bzero(&icmp6dst, sizeof(icmp6dst)); 1151 icmp6dst.sin6_len = sizeof(struct sockaddr_in6); 1152 icmp6dst.sin6_family = AF_INET6; 1153 if (finaldst == NULL) 1154 icmp6dst.sin6_addr = eip6->ip6_dst; 1155 else 1156 icmp6dst.sin6_addr = *finaldst; 1157 if (in6_setscope(&icmp6dst.sin6_addr, m->m_pkthdr.rcvif, NULL)) 1158 goto freeit; 1159 bzero(&icmp6src, sizeof(icmp6src)); 1160 icmp6src.sin6_len = sizeof(struct sockaddr_in6); 1161 icmp6src.sin6_family = AF_INET6; 1162 icmp6src.sin6_addr = eip6->ip6_src; 1163 if (in6_setscope(&icmp6src.sin6_addr, m->m_pkthdr.rcvif, NULL)) 1164 goto freeit; 1165 icmp6src.sin6_flowinfo = 1166 (eip6->ip6_flow & IPV6_FLOWLABEL_MASK); 1167 1168 if (finaldst == NULL) 1169 finaldst = &eip6->ip6_dst; 1170 ip6cp.ip6c_m = m; 1171 ip6cp.ip6c_icmp6 = icmp6; 1172 ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1); 1173 ip6cp.ip6c_off = eoff; 1174 ip6cp.ip6c_finaldst = finaldst; 1175 ip6cp.ip6c_src = &icmp6src; 1176 ip6cp.ip6c_nxt = nxt; 1177 1178 m_addr_changed(m); 1179 1180 if (icmp6type == ICMP6_PACKET_TOO_BIG) { 1181 notifymtu = ntohl(icmp6->icmp6_mtu); 1182 ip6cp.ip6c_cmdarg = (void *)¬ifymtu; 1183 icmp6_mtudisc_update(&ip6cp, 1); /*XXX*/ 1184 } 1185 1186 ctlfunc = (void (*)(int, struct sockaddr *, void *)) 1187 (inet6sw[ip6_protox[nxt]].pr_ctlinput); 1188 if (ctlfunc) { 1189 (void) (*ctlfunc)(code, (struct sockaddr *)&icmp6dst, 1190 &ip6cp); 1191 } 1192 } 1193 *mp = m; 1194 return (0); 1195 1196 freeit: 1197 m_freem(m); 1198 return (-1); 1199 } 1200 1201 void 1202 icmp6_mtudisc_update(struct ip6ctlparam *ip6cp, int validated) 1203 { 1204 struct in6_addr *dst = ip6cp->ip6c_finaldst; 1205 struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6; 1206 struct mbuf *m = ip6cp->ip6c_m; /* will be necessary for scope issue */ 1207 u_int mtu = ntohl(icmp6->icmp6_mtu); 1208 struct in_conninfo inc; 1209 1210 #if 0 1211 /* 1212 * RFC2460 section 5, last paragraph. 1213 * even though minimum link MTU for IPv6 is IPV6_MMTU, 1214 * we may see ICMPv6 too big with mtu < IPV6_MMTU 1215 * due to packet translator in the middle. 1216 * see ip6_output() and ip6_getpmtu() "alwaysfrag" case for 1217 * special handling. 1218 */ 1219 if (mtu < IPV6_MMTU) 1220 return; 1221 #endif 1222 1223 /* 1224 * we reject ICMPv6 too big with abnormally small value. 1225 * XXX what is the good definition of "abnormally small"? 1226 */ 1227 if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8) 1228 return; 1229 1230 if (!validated) 1231 return; 1232 1233 /* 1234 * In case the suggested mtu is less than IPV6_MMTU, we 1235 * only need to remember that it was for above mentioned 1236 * "alwaysfrag" case. 1237 * Try to be as close to the spec as possible. 1238 */ 1239 if (mtu < IPV6_MMTU) 1240 mtu = IPV6_MMTU - 8; 1241 1242 bzero(&inc, sizeof(inc)); 1243 inc.inc_fibnum = M_GETFIB(m); 1244 inc.inc_flags |= INC_ISIPV6; 1245 inc.inc6_faddr = *dst; 1246 if (in6_setscope(&inc.inc6_faddr, m->m_pkthdr.rcvif, NULL)) 1247 return; 1248 1249 if (mtu < tcp_maxmtu6(&inc, NULL)) { 1250 tcp_hc_updatemtu(&inc, mtu); 1251 ICMP6STAT_INC(icp6s_pmtuchg); 1252 } 1253 } 1254 1255 /* 1256 * Process a Node Information Query packet, based on 1257 * draft-ietf-ipngwg-icmp-name-lookups-07. 1258 * 1259 * Spec incompatibilities: 1260 * - IPv6 Subject address handling 1261 * - IPv4 Subject address handling support missing 1262 * - Proxy reply (answer even if it's not for me) 1263 * - joins NI group address at in6_ifattach() time only, does not cope 1264 * with hostname changes by sethostname(3) 1265 */ 1266 static struct mbuf * 1267 ni6_input(struct mbuf *m, int off) 1268 { 1269 struct icmp6_nodeinfo *ni6, *nni6; 1270 struct mbuf *n = NULL; 1271 struct prison *pr; 1272 u_int16_t qtype; 1273 int subjlen; 1274 int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); 1275 struct ni_reply_fqdn *fqdn; 1276 int addrs; /* for NI_QTYPE_NODEADDR */ 1277 struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */ 1278 struct in6_addr in6_subj; /* subject address */ 1279 struct ip6_hdr *ip6; 1280 int oldfqdn = 0; /* if 1, return pascal string (03 draft) */ 1281 char *subj = NULL; 1282 struct in6_ifaddr *ia6 = NULL; 1283 1284 ip6 = mtod(m, struct ip6_hdr *); 1285 #ifndef PULLDOWN_TEST 1286 ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off); 1287 #else 1288 IP6_EXTHDR_GET(ni6, struct icmp6_nodeinfo *, m, off, sizeof(*ni6)); 1289 if (ni6 == NULL) { 1290 /* m is already reclaimed */ 1291 return (NULL); 1292 } 1293 #endif 1294 1295 /* 1296 * Validate IPv6 source address. 1297 * The default configuration MUST be to refuse answering queries from 1298 * global-scope addresses according to RFC4602. 1299 * Notes: 1300 * - it's not very clear what "refuse" means; this implementation 1301 * simply drops it. 1302 * - it's not very easy to identify global-scope (unicast) addresses 1303 * since there are many prefixes for them. It should be safer 1304 * and in practice sufficient to check "all" but loopback and 1305 * link-local (note that site-local unicast was deprecated and 1306 * ULA is defined as global scope-wise) 1307 */ 1308 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_GLOBALOK) == 0 && 1309 !IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) && 1310 !IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) 1311 goto bad; 1312 1313 /* 1314 * Validate IPv6 destination address. 1315 * 1316 * The Responder must discard the Query without further processing 1317 * unless it is one of the Responder's unicast or anycast addresses, or 1318 * a link-local scope multicast address which the Responder has joined. 1319 * [RFC4602, Section 5.] 1320 */ 1321 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 1322 if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst)) 1323 goto bad; 1324 /* else it's a link-local multicast, fine */ 1325 } else { /* unicast or anycast */ 1326 if ((ia6 = ip6_getdstifaddr(m)) == NULL) 1327 goto bad; /* XXX impossible */ 1328 1329 if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) && 1330 !(V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK)) { 1331 ifa_free(&ia6->ia_ifa); 1332 nd6log((LOG_DEBUG, "ni6_input: ignore node info to " 1333 "a temporary address in %s:%d", 1334 __FILE__, __LINE__)); 1335 goto bad; 1336 } 1337 ifa_free(&ia6->ia_ifa); 1338 } 1339 1340 /* validate query Subject field. */ 1341 qtype = ntohs(ni6->ni_qtype); 1342 subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo); 1343 switch (qtype) { 1344 case NI_QTYPE_NOOP: 1345 case NI_QTYPE_SUPTYPES: 1346 /* 07 draft */ 1347 if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0) 1348 break; 1349 /* FALLTHROUGH */ 1350 case NI_QTYPE_FQDN: 1351 case NI_QTYPE_NODEADDR: 1352 case NI_QTYPE_IPV4ADDR: 1353 switch (ni6->ni_code) { 1354 case ICMP6_NI_SUBJ_IPV6: 1355 #if ICMP6_NI_SUBJ_IPV6 != 0 1356 case 0: 1357 #endif 1358 /* 1359 * backward compatibility - try to accept 03 draft 1360 * format, where no Subject is present. 1361 */ 1362 if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 && 1363 subjlen == 0) { 1364 oldfqdn++; 1365 break; 1366 } 1367 #if ICMP6_NI_SUBJ_IPV6 != 0 1368 if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6) 1369 goto bad; 1370 #endif 1371 1372 if (subjlen != sizeof(struct in6_addr)) 1373 goto bad; 1374 1375 /* 1376 * Validate Subject address. 1377 * 1378 * Not sure what exactly "address belongs to the node" 1379 * means in the spec, is it just unicast, or what? 1380 * 1381 * At this moment we consider Subject address as 1382 * "belong to the node" if the Subject address equals 1383 * to the IPv6 destination address; validation for 1384 * IPv6 destination address should have done enough 1385 * check for us. 1386 * 1387 * We do not do proxy at this moment. 1388 */ 1389 /* m_pulldown instead of copy? */ 1390 m_copydata(m, off + sizeof(struct icmp6_nodeinfo), 1391 subjlen, (caddr_t)&in6_subj); 1392 if (in6_setscope(&in6_subj, m->m_pkthdr.rcvif, NULL)) 1393 goto bad; 1394 1395 subj = (char *)&in6_subj; 1396 if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &in6_subj)) 1397 break; 1398 1399 /* 1400 * XXX if we are to allow other cases, we should really 1401 * be careful about scope here. 1402 * basically, we should disallow queries toward IPv6 1403 * destination X with subject Y, 1404 * if scope(X) > scope(Y). 1405 * if we allow scope(X) > scope(Y), it will result in 1406 * information leakage across scope boundary. 1407 */ 1408 goto bad; 1409 1410 case ICMP6_NI_SUBJ_FQDN: 1411 /* 1412 * Validate Subject name with gethostname(3). 1413 * 1414 * The behavior may need some debate, since: 1415 * - we are not sure if the node has FQDN as 1416 * hostname (returned by gethostname(3)). 1417 * - the code does wildcard match for truncated names. 1418 * however, we are not sure if we want to perform 1419 * wildcard match, if gethostname(3) side has 1420 * truncated hostname. 1421 */ 1422 pr = curthread->td_ucred->cr_prison; 1423 mtx_lock(&pr->pr_mtx); 1424 n = ni6_nametodns(pr->pr_hostname, 1425 strlen(pr->pr_hostname), 0); 1426 mtx_unlock(&pr->pr_mtx); 1427 if (!n || n->m_next || n->m_len == 0) 1428 goto bad; 1429 IP6_EXTHDR_GET(subj, char *, m, 1430 off + sizeof(struct icmp6_nodeinfo), subjlen); 1431 if (subj == NULL) 1432 goto bad; 1433 if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *), 1434 n->m_len)) { 1435 goto bad; 1436 } 1437 m_freem(n); 1438 n = NULL; 1439 break; 1440 1441 case ICMP6_NI_SUBJ_IPV4: /* XXX: to be implemented? */ 1442 default: 1443 goto bad; 1444 } 1445 break; 1446 } 1447 1448 /* refuse based on configuration. XXX ICMP6_NI_REFUSED? */ 1449 switch (qtype) { 1450 case NI_QTYPE_FQDN: 1451 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_FQDNOK) == 0) 1452 goto bad; 1453 break; 1454 case NI_QTYPE_NODEADDR: 1455 case NI_QTYPE_IPV4ADDR: 1456 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_NODEADDROK) == 0) 1457 goto bad; 1458 break; 1459 } 1460 1461 /* guess reply length */ 1462 switch (qtype) { 1463 case NI_QTYPE_NOOP: 1464 break; /* no reply data */ 1465 case NI_QTYPE_SUPTYPES: 1466 replylen += sizeof(u_int32_t); 1467 break; 1468 case NI_QTYPE_FQDN: 1469 /* XXX will append an mbuf */ 1470 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); 1471 break; 1472 case NI_QTYPE_NODEADDR: 1473 addrs = ni6_addrs(ni6, m, &ifp, (struct in6_addr *)subj); 1474 if ((replylen += addrs * (sizeof(struct in6_addr) + 1475 sizeof(u_int32_t))) > MCLBYTES) 1476 replylen = MCLBYTES; /* XXX: will truncate pkt later */ 1477 break; 1478 case NI_QTYPE_IPV4ADDR: 1479 /* unsupported - should respond with unknown Qtype? */ 1480 break; 1481 default: 1482 /* 1483 * XXX: We must return a reply with the ICMP6 code 1484 * `unknown Qtype' in this case. However we regard the case 1485 * as an FQDN query for backward compatibility. 1486 * Older versions set a random value to this field, 1487 * so it rarely varies in the defined qtypes. 1488 * But the mechanism is not reliable... 1489 * maybe we should obsolete older versions. 1490 */ 1491 qtype = NI_QTYPE_FQDN; 1492 /* XXX will append an mbuf */ 1493 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); 1494 oldfqdn++; 1495 break; 1496 } 1497 1498 /* allocate an mbuf to reply. */ 1499 MGETHDR(n, M_DONTWAIT, m->m_type); 1500 if (n == NULL) { 1501 m_freem(m); 1502 return (NULL); 1503 } 1504 M_MOVE_PKTHDR(n, m); /* just for recvif and FIB */ 1505 if (replylen > MHLEN) { 1506 if (replylen > MCLBYTES) { 1507 /* 1508 * XXX: should we try to allocate more? But MCLBYTES 1509 * is probably much larger than IPV6_MMTU... 1510 */ 1511 goto bad; 1512 } 1513 MCLGET(n, M_DONTWAIT); 1514 if ((n->m_flags & M_EXT) == 0) { 1515 goto bad; 1516 } 1517 } 1518 n->m_pkthdr.len = n->m_len = replylen; 1519 1520 /* copy mbuf header and IPv6 + Node Information base headers */ 1521 bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr)); 1522 nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1); 1523 bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo)); 1524 1525 /* qtype dependent procedure */ 1526 switch (qtype) { 1527 case NI_QTYPE_NOOP: 1528 nni6->ni_code = ICMP6_NI_SUCCESS; 1529 nni6->ni_flags = 0; 1530 break; 1531 case NI_QTYPE_SUPTYPES: 1532 { 1533 u_int32_t v; 1534 nni6->ni_code = ICMP6_NI_SUCCESS; 1535 nni6->ni_flags = htons(0x0000); /* raw bitmap */ 1536 /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */ 1537 v = (u_int32_t)htonl(0x0000000f); 1538 bcopy(&v, nni6 + 1, sizeof(u_int32_t)); 1539 break; 1540 } 1541 case NI_QTYPE_FQDN: 1542 nni6->ni_code = ICMP6_NI_SUCCESS; 1543 fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) + 1544 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo)); 1545 nni6->ni_flags = 0; /* XXX: meaningless TTL */ 1546 fqdn->ni_fqdn_ttl = 0; /* ditto. */ 1547 /* 1548 * XXX do we really have FQDN in hostname? 1549 */ 1550 pr = curthread->td_ucred->cr_prison; 1551 mtx_lock(&pr->pr_mtx); 1552 n->m_next = ni6_nametodns(pr->pr_hostname, 1553 strlen(pr->pr_hostname), oldfqdn); 1554 mtx_unlock(&pr->pr_mtx); 1555 if (n->m_next == NULL) 1556 goto bad; 1557 /* XXX we assume that n->m_next is not a chain */ 1558 if (n->m_next->m_next != NULL) 1559 goto bad; 1560 n->m_pkthdr.len += n->m_next->m_len; 1561 break; 1562 case NI_QTYPE_NODEADDR: 1563 { 1564 int lenlim, copied; 1565 1566 nni6->ni_code = ICMP6_NI_SUCCESS; 1567 n->m_pkthdr.len = n->m_len = 1568 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); 1569 lenlim = M_TRAILINGSPACE(n); 1570 copied = ni6_store_addrs(ni6, nni6, ifp, lenlim); 1571 /* XXX: reset mbuf length */ 1572 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + 1573 sizeof(struct icmp6_nodeinfo) + copied; 1574 break; 1575 } 1576 default: 1577 break; /* XXX impossible! */ 1578 } 1579 1580 nni6->ni_type = ICMP6_NI_REPLY; 1581 m_freem(m); 1582 return (n); 1583 1584 bad: 1585 m_freem(m); 1586 if (n) 1587 m_freem(n); 1588 return (NULL); 1589 } 1590 1591 /* 1592 * make a mbuf with DNS-encoded string. no compression support. 1593 * 1594 * XXX names with less than 2 dots (like "foo" or "foo.section") will be 1595 * treated as truncated name (two \0 at the end). this is a wild guess. 1596 * 1597 * old - return pascal string if non-zero 1598 */ 1599 static struct mbuf * 1600 ni6_nametodns(const char *name, int namelen, int old) 1601 { 1602 struct mbuf *m; 1603 char *cp, *ep; 1604 const char *p, *q; 1605 int i, len, nterm; 1606 1607 if (old) 1608 len = namelen + 1; 1609 else 1610 len = MCLBYTES; 1611 1612 /* because MAXHOSTNAMELEN is usually 256, we use cluster mbuf */ 1613 MGET(m, M_DONTWAIT, MT_DATA); 1614 if (m && len > MLEN) { 1615 MCLGET(m, M_DONTWAIT); 1616 if ((m->m_flags & M_EXT) == 0) 1617 goto fail; 1618 } 1619 if (!m) 1620 goto fail; 1621 m->m_next = NULL; 1622 1623 if (old) { 1624 m->m_len = len; 1625 *mtod(m, char *) = namelen; 1626 bcopy(name, mtod(m, char *) + 1, namelen); 1627 return m; 1628 } else { 1629 m->m_len = 0; 1630 cp = mtod(m, char *); 1631 ep = mtod(m, char *) + M_TRAILINGSPACE(m); 1632 1633 /* if not certain about my name, return empty buffer */ 1634 if (namelen == 0) 1635 return m; 1636 1637 /* 1638 * guess if it looks like shortened hostname, or FQDN. 1639 * shortened hostname needs two trailing "\0". 1640 */ 1641 i = 0; 1642 for (p = name; p < name + namelen; p++) { 1643 if (*p && *p == '.') 1644 i++; 1645 } 1646 if (i < 2) 1647 nterm = 2; 1648 else 1649 nterm = 1; 1650 1651 p = name; 1652 while (cp < ep && p < name + namelen) { 1653 i = 0; 1654 for (q = p; q < name + namelen && *q && *q != '.'; q++) 1655 i++; 1656 /* result does not fit into mbuf */ 1657 if (cp + i + 1 >= ep) 1658 goto fail; 1659 /* 1660 * DNS label length restriction, RFC1035 page 8. 1661 * "i == 0" case is included here to avoid returning 1662 * 0-length label on "foo..bar". 1663 */ 1664 if (i <= 0 || i >= 64) 1665 goto fail; 1666 *cp++ = i; 1667 bcopy(p, cp, i); 1668 cp += i; 1669 p = q; 1670 if (p < name + namelen && *p == '.') 1671 p++; 1672 } 1673 /* termination */ 1674 if (cp + nterm >= ep) 1675 goto fail; 1676 while (nterm-- > 0) 1677 *cp++ = '\0'; 1678 m->m_len = cp - mtod(m, char *); 1679 return m; 1680 } 1681 1682 panic("should not reach here"); 1683 /* NOTREACHED */ 1684 1685 fail: 1686 if (m) 1687 m_freem(m); 1688 return NULL; 1689 } 1690 1691 /* 1692 * check if two DNS-encoded string matches. takes care of truncated 1693 * form (with \0\0 at the end). no compression support. 1694 * XXX upper/lowercase match (see RFC2065) 1695 */ 1696 static int 1697 ni6_dnsmatch(const char *a, int alen, const char *b, int blen) 1698 { 1699 const char *a0, *b0; 1700 int l; 1701 1702 /* simplest case - need validation? */ 1703 if (alen == blen && bcmp(a, b, alen) == 0) 1704 return 1; 1705 1706 a0 = a; 1707 b0 = b; 1708 1709 /* termination is mandatory */ 1710 if (alen < 2 || blen < 2) 1711 return 0; 1712 if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0') 1713 return 0; 1714 alen--; 1715 blen--; 1716 1717 while (a - a0 < alen && b - b0 < blen) { 1718 if (a - a0 + 1 > alen || b - b0 + 1 > blen) 1719 return 0; 1720 1721 if ((signed char)a[0] < 0 || (signed char)b[0] < 0) 1722 return 0; 1723 /* we don't support compression yet */ 1724 if (a[0] >= 64 || b[0] >= 64) 1725 return 0; 1726 1727 /* truncated case */ 1728 if (a[0] == 0 && a - a0 == alen - 1) 1729 return 1; 1730 if (b[0] == 0 && b - b0 == blen - 1) 1731 return 1; 1732 if (a[0] == 0 || b[0] == 0) 1733 return 0; 1734 1735 if (a[0] != b[0]) 1736 return 0; 1737 l = a[0]; 1738 if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen) 1739 return 0; 1740 if (bcmp(a + 1, b + 1, l) != 0) 1741 return 0; 1742 1743 a += 1 + l; 1744 b += 1 + l; 1745 } 1746 1747 if (a - a0 == alen && b - b0 == blen) 1748 return 1; 1749 else 1750 return 0; 1751 } 1752 1753 /* 1754 * calculate the number of addresses to be returned in the node info reply. 1755 */ 1756 static int 1757 ni6_addrs(struct icmp6_nodeinfo *ni6, struct mbuf *m, struct ifnet **ifpp, 1758 struct in6_addr *subj) 1759 { 1760 struct ifnet *ifp; 1761 struct in6_ifaddr *ifa6; 1762 struct ifaddr *ifa; 1763 int addrs = 0, addrsofif, iffound = 0; 1764 int niflags = ni6->ni_flags; 1765 1766 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) { 1767 switch (ni6->ni_code) { 1768 case ICMP6_NI_SUBJ_IPV6: 1769 if (subj == NULL) /* must be impossible... */ 1770 return (0); 1771 break; 1772 default: 1773 /* 1774 * XXX: we only support IPv6 subject address for 1775 * this Qtype. 1776 */ 1777 return (0); 1778 } 1779 } 1780 1781 IFNET_RLOCK_NOSLEEP(); 1782 TAILQ_FOREACH(ifp, &V_ifnet, if_list) { 1783 addrsofif = 0; 1784 IF_ADDR_RLOCK(ifp); 1785 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 1786 if (ifa->ifa_addr->sa_family != AF_INET6) 1787 continue; 1788 ifa6 = (struct in6_ifaddr *)ifa; 1789 1790 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 && 1791 IN6_ARE_ADDR_EQUAL(subj, &ifa6->ia_addr.sin6_addr)) 1792 iffound = 1; 1793 1794 /* 1795 * IPv4-mapped addresses can only be returned by a 1796 * Node Information proxy, since they represent 1797 * addresses of IPv4-only nodes, which perforce do 1798 * not implement this protocol. 1799 * [icmp-name-lookups-07, Section 5.4] 1800 * So we don't support NI_NODEADDR_FLAG_COMPAT in 1801 * this function at this moment. 1802 */ 1803 1804 /* What do we have to do about ::1? */ 1805 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { 1806 case IPV6_ADDR_SCOPE_LINKLOCAL: 1807 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) 1808 continue; 1809 break; 1810 case IPV6_ADDR_SCOPE_SITELOCAL: 1811 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) 1812 continue; 1813 break; 1814 case IPV6_ADDR_SCOPE_GLOBAL: 1815 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) 1816 continue; 1817 break; 1818 default: 1819 continue; 1820 } 1821 1822 /* 1823 * check if anycast is okay. 1824 * XXX: just experimental. not in the spec. 1825 */ 1826 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && 1827 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) 1828 continue; /* we need only unicast addresses */ 1829 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && 1830 (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) { 1831 continue; 1832 } 1833 addrsofif++; /* count the address */ 1834 } 1835 IF_ADDR_RUNLOCK(ifp); 1836 if (iffound) { 1837 *ifpp = ifp; 1838 IFNET_RUNLOCK_NOSLEEP(); 1839 return (addrsofif); 1840 } 1841 1842 addrs += addrsofif; 1843 } 1844 IFNET_RUNLOCK_NOSLEEP(); 1845 1846 return (addrs); 1847 } 1848 1849 static int 1850 ni6_store_addrs(struct icmp6_nodeinfo *ni6, struct icmp6_nodeinfo *nni6, 1851 struct ifnet *ifp0, int resid) 1852 { 1853 struct ifnet *ifp; 1854 struct in6_ifaddr *ifa6; 1855 struct ifaddr *ifa; 1856 struct ifnet *ifp_dep = NULL; 1857 int copied = 0, allow_deprecated = 0; 1858 u_char *cp = (u_char *)(nni6 + 1); 1859 int niflags = ni6->ni_flags; 1860 u_int32_t ltime; 1861 1862 if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL)) 1863 return (0); /* needless to copy */ 1864 1865 IFNET_RLOCK_NOSLEEP(); 1866 ifp = ifp0 ? ifp0 : TAILQ_FIRST(&V_ifnet); 1867 again: 1868 1869 for (; ifp; ifp = TAILQ_NEXT(ifp, if_list)) { 1870 IF_ADDR_RLOCK(ifp); 1871 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 1872 if (ifa->ifa_addr->sa_family != AF_INET6) 1873 continue; 1874 ifa6 = (struct in6_ifaddr *)ifa; 1875 1876 if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 && 1877 allow_deprecated == 0) { 1878 /* 1879 * prefererred address should be put before 1880 * deprecated addresses. 1881 */ 1882 1883 /* record the interface for later search */ 1884 if (ifp_dep == NULL) 1885 ifp_dep = ifp; 1886 1887 continue; 1888 } else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 && 1889 allow_deprecated != 0) 1890 continue; /* we now collect deprecated addrs */ 1891 1892 /* What do we have to do about ::1? */ 1893 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { 1894 case IPV6_ADDR_SCOPE_LINKLOCAL: 1895 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) 1896 continue; 1897 break; 1898 case IPV6_ADDR_SCOPE_SITELOCAL: 1899 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) 1900 continue; 1901 break; 1902 case IPV6_ADDR_SCOPE_GLOBAL: 1903 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) 1904 continue; 1905 break; 1906 default: 1907 continue; 1908 } 1909 1910 /* 1911 * check if anycast is okay. 1912 * XXX: just experimental. not in the spec. 1913 */ 1914 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && 1915 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) 1916 continue; 1917 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && 1918 (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) { 1919 continue; 1920 } 1921 1922 /* now we can copy the address */ 1923 if (resid < sizeof(struct in6_addr) + 1924 sizeof(u_int32_t)) { 1925 IF_ADDR_RUNLOCK(ifp); 1926 /* 1927 * We give up much more copy. 1928 * Set the truncate flag and return. 1929 */ 1930 nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE; 1931 IFNET_RUNLOCK_NOSLEEP(); 1932 return (copied); 1933 } 1934 1935 /* 1936 * Set the TTL of the address. 1937 * The TTL value should be one of the following 1938 * according to the specification: 1939 * 1940 * 1. The remaining lifetime of a DHCP lease on the 1941 * address, or 1942 * 2. The remaining Valid Lifetime of a prefix from 1943 * which the address was derived through Stateless 1944 * Autoconfiguration. 1945 * 1946 * Note that we currently do not support stateful 1947 * address configuration by DHCPv6, so the former 1948 * case can't happen. 1949 */ 1950 if (ifa6->ia6_lifetime.ia6t_expire == 0) 1951 ltime = ND6_INFINITE_LIFETIME; 1952 else { 1953 if (ifa6->ia6_lifetime.ia6t_expire > 1954 time_second) 1955 ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_second); 1956 else 1957 ltime = 0; 1958 } 1959 1960 bcopy(<ime, cp, sizeof(u_int32_t)); 1961 cp += sizeof(u_int32_t); 1962 1963 /* copy the address itself */ 1964 bcopy(&ifa6->ia_addr.sin6_addr, cp, 1965 sizeof(struct in6_addr)); 1966 in6_clearscope((struct in6_addr *)cp); /* XXX */ 1967 cp += sizeof(struct in6_addr); 1968 1969 resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t)); 1970 copied += (sizeof(struct in6_addr) + sizeof(u_int32_t)); 1971 } 1972 IF_ADDR_RUNLOCK(ifp); 1973 if (ifp0) /* we need search only on the specified IF */ 1974 break; 1975 } 1976 1977 if (allow_deprecated == 0 && ifp_dep != NULL) { 1978 ifp = ifp_dep; 1979 allow_deprecated = 1; 1980 1981 goto again; 1982 } 1983 1984 IFNET_RUNLOCK_NOSLEEP(); 1985 1986 return (copied); 1987 } 1988 1989 /* 1990 * XXX almost dup'ed code with rip6_input. 1991 */ 1992 static int 1993 icmp6_rip6_input(struct mbuf **mp, int off) 1994 { 1995 struct mbuf *m = *mp; 1996 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1997 struct inpcb *in6p; 1998 struct inpcb *last = NULL; 1999 struct sockaddr_in6 fromsa; 2000 struct icmp6_hdr *icmp6; 2001 struct mbuf *opts = NULL; 2002 2003 #ifndef PULLDOWN_TEST 2004 /* this is assumed to be safe. */ 2005 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off); 2006 #else 2007 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6)); 2008 if (icmp6 == NULL) { 2009 /* m is already reclaimed */ 2010 return (IPPROTO_DONE); 2011 } 2012 #endif 2013 2014 /* 2015 * XXX: the address may have embedded scope zone ID, which should be 2016 * hidden from applications. 2017 */ 2018 bzero(&fromsa, sizeof(fromsa)); 2019 fromsa.sin6_family = AF_INET6; 2020 fromsa.sin6_len = sizeof(struct sockaddr_in6); 2021 fromsa.sin6_addr = ip6->ip6_src; 2022 if (sa6_recoverscope(&fromsa)) { 2023 m_freem(m); 2024 return (IPPROTO_DONE); 2025 } 2026 2027 INP_INFO_RLOCK(&V_ripcbinfo); 2028 LIST_FOREACH(in6p, &V_ripcb, inp_list) { 2029 if ((in6p->inp_vflag & INP_IPV6) == 0) 2030 continue; 2031 if (in6p->inp_ip_p != IPPROTO_ICMPV6) 2032 continue; 2033 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) && 2034 !IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &ip6->ip6_dst)) 2035 continue; 2036 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr) && 2037 !IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src)) 2038 continue; 2039 INP_RLOCK(in6p); 2040 if (ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type, 2041 in6p->in6p_icmp6filt)) { 2042 INP_RUNLOCK(in6p); 2043 continue; 2044 } 2045 if (last != NULL) { 2046 struct mbuf *n = NULL; 2047 2048 /* 2049 * Recent network drivers tend to allocate a single 2050 * mbuf cluster, rather than to make a couple of 2051 * mbufs without clusters. Also, since the IPv6 code 2052 * path tries to avoid m_pullup(), it is highly 2053 * probable that we still have an mbuf cluster here 2054 * even though the necessary length can be stored in an 2055 * mbuf's internal buffer. 2056 * Meanwhile, the default size of the receive socket 2057 * buffer for raw sockets is not so large. This means 2058 * the possibility of packet loss is relatively higher 2059 * than before. To avoid this scenario, we copy the 2060 * received data to a separate mbuf that does not use 2061 * a cluster, if possible. 2062 * XXX: it is better to copy the data after stripping 2063 * intermediate headers. 2064 */ 2065 if ((m->m_flags & M_EXT) && m->m_next == NULL && 2066 m->m_len <= MHLEN) { 2067 MGET(n, M_DONTWAIT, m->m_type); 2068 if (n != NULL) { 2069 if (m_dup_pkthdr(n, m, M_NOWAIT)) { 2070 bcopy(m->m_data, n->m_data, 2071 m->m_len); 2072 n->m_len = m->m_len; 2073 } else { 2074 m_free(n); 2075 n = NULL; 2076 } 2077 } 2078 } 2079 if (n != NULL || 2080 (n = m_copy(m, 0, (int)M_COPYALL)) != NULL) { 2081 if (last->inp_flags & INP_CONTROLOPTS) 2082 ip6_savecontrol(last, n, &opts); 2083 /* strip intermediate headers */ 2084 m_adj(n, off); 2085 SOCKBUF_LOCK(&last->inp_socket->so_rcv); 2086 if (sbappendaddr_locked( 2087 &last->inp_socket->so_rcv, 2088 (struct sockaddr *)&fromsa, n, opts) 2089 == 0) { 2090 /* should notify about lost packet */ 2091 m_freem(n); 2092 if (opts) { 2093 m_freem(opts); 2094 } 2095 SOCKBUF_UNLOCK( 2096 &last->inp_socket->so_rcv); 2097 } else 2098 sorwakeup_locked(last->inp_socket); 2099 opts = NULL; 2100 } 2101 INP_RUNLOCK(last); 2102 } 2103 last = in6p; 2104 } 2105 INP_INFO_RUNLOCK(&V_ripcbinfo); 2106 if (last != NULL) { 2107 if (last->inp_flags & INP_CONTROLOPTS) 2108 ip6_savecontrol(last, m, &opts); 2109 /* strip intermediate headers */ 2110 m_adj(m, off); 2111 2112 /* avoid using mbuf clusters if possible (see above) */ 2113 if ((m->m_flags & M_EXT) && m->m_next == NULL && 2114 m->m_len <= MHLEN) { 2115 struct mbuf *n; 2116 2117 MGET(n, M_DONTWAIT, m->m_type); 2118 if (n != NULL) { 2119 if (m_dup_pkthdr(n, m, M_NOWAIT)) { 2120 bcopy(m->m_data, n->m_data, m->m_len); 2121 n->m_len = m->m_len; 2122 2123 m_freem(m); 2124 m = n; 2125 } else { 2126 m_freem(n); 2127 n = NULL; 2128 } 2129 } 2130 } 2131 SOCKBUF_LOCK(&last->inp_socket->so_rcv); 2132 if (sbappendaddr_locked(&last->inp_socket->so_rcv, 2133 (struct sockaddr *)&fromsa, m, opts) == 0) { 2134 m_freem(m); 2135 if (opts) 2136 m_freem(opts); 2137 SOCKBUF_UNLOCK(&last->inp_socket->so_rcv); 2138 } else 2139 sorwakeup_locked(last->inp_socket); 2140 INP_RUNLOCK(last); 2141 } else { 2142 m_freem(m); 2143 IP6STAT_DEC(ip6s_delivered); 2144 } 2145 return IPPROTO_DONE; 2146 } 2147 2148 /* 2149 * Reflect the ip6 packet back to the source. 2150 * OFF points to the icmp6 header, counted from the top of the mbuf. 2151 */ 2152 void 2153 icmp6_reflect(struct mbuf *m, size_t off) 2154 { 2155 struct ip6_hdr *ip6; 2156 struct icmp6_hdr *icmp6; 2157 struct in6_ifaddr *ia = NULL; 2158 int plen; 2159 int type, code; 2160 struct ifnet *outif = NULL; 2161 struct in6_addr origdst, src, *srcp = NULL; 2162 2163 /* too short to reflect */ 2164 if (off < sizeof(struct ip6_hdr)) { 2165 nd6log((LOG_DEBUG, 2166 "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n", 2167 (u_long)off, (u_long)sizeof(struct ip6_hdr), 2168 __FILE__, __LINE__)); 2169 goto bad; 2170 } 2171 2172 /* 2173 * If there are extra headers between IPv6 and ICMPv6, strip 2174 * off that header first. 2175 */ 2176 #ifdef DIAGNOSTIC 2177 if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN) 2178 panic("assumption failed in icmp6_reflect"); 2179 #endif 2180 if (off > sizeof(struct ip6_hdr)) { 2181 size_t l; 2182 struct ip6_hdr nip6; 2183 2184 l = off - sizeof(struct ip6_hdr); 2185 m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6); 2186 m_adj(m, l); 2187 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 2188 if (m->m_len < l) { 2189 if ((m = m_pullup(m, l)) == NULL) 2190 return; 2191 } 2192 bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6)); 2193 } else /* off == sizeof(struct ip6_hdr) */ { 2194 size_t l; 2195 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 2196 if (m->m_len < l) { 2197 if ((m = m_pullup(m, l)) == NULL) 2198 return; 2199 } 2200 } 2201 plen = m->m_pkthdr.len - sizeof(struct ip6_hdr); 2202 ip6 = mtod(m, struct ip6_hdr *); 2203 ip6->ip6_nxt = IPPROTO_ICMPV6; 2204 icmp6 = (struct icmp6_hdr *)(ip6 + 1); 2205 type = icmp6->icmp6_type; /* keep type for statistics */ 2206 code = icmp6->icmp6_code; /* ditto. */ 2207 2208 origdst = ip6->ip6_dst; 2209 /* 2210 * ip6_input() drops a packet if its src is multicast. 2211 * So, the src is never multicast. 2212 */ 2213 ip6->ip6_dst = ip6->ip6_src; 2214 2215 /* 2216 * If the incoming packet was addressed directly to us (i.e. unicast), 2217 * use dst as the src for the reply. 2218 * The IN6_IFF_NOTREADY case should be VERY rare, but is possible 2219 * (for example) when we encounter an error while forwarding procedure 2220 * destined to a duplicated address of ours. 2221 * Note that ip6_getdstifaddr() may fail if we are in an error handling 2222 * procedure of an outgoing packet of our own, in which case we need 2223 * to search in the ifaddr list. 2224 */ 2225 if (!IN6_IS_ADDR_MULTICAST(&origdst)) { 2226 if ((ia = ip6_getdstifaddr(m))) { 2227 if (!(ia->ia6_flags & 2228 (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) 2229 srcp = &ia->ia_addr.sin6_addr; 2230 } else { 2231 struct sockaddr_in6 d; 2232 2233 bzero(&d, sizeof(d)); 2234 d.sin6_family = AF_INET6; 2235 d.sin6_len = sizeof(d); 2236 d.sin6_addr = origdst; 2237 ia = (struct in6_ifaddr *) 2238 ifa_ifwithaddr((struct sockaddr *)&d); 2239 if (ia && 2240 !(ia->ia6_flags & 2241 (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) { 2242 srcp = &ia->ia_addr.sin6_addr; 2243 } 2244 } 2245 } 2246 2247 if (srcp == NULL) { 2248 int e; 2249 struct sockaddr_in6 sin6; 2250 struct route_in6 ro; 2251 2252 /* 2253 * This case matches to multicasts, our anycast, or unicasts 2254 * that we do not own. Select a source address based on the 2255 * source address of the erroneous packet. 2256 */ 2257 bzero(&sin6, sizeof(sin6)); 2258 sin6.sin6_family = AF_INET6; 2259 sin6.sin6_len = sizeof(sin6); 2260 sin6.sin6_addr = ip6->ip6_dst; /* zone ID should be embedded */ 2261 2262 bzero(&ro, sizeof(ro)); 2263 e = in6_selectsrc(&sin6, NULL, NULL, &ro, NULL, &outif, &src); 2264 if (ro.ro_rt) 2265 RTFREE(ro.ro_rt); /* XXX: we could use this */ 2266 if (e) { 2267 char ip6buf[INET6_ADDRSTRLEN]; 2268 nd6log((LOG_DEBUG, 2269 "icmp6_reflect: source can't be determined: " 2270 "dst=%s, error=%d\n", 2271 ip6_sprintf(ip6buf, &sin6.sin6_addr), e)); 2272 goto bad; 2273 } 2274 srcp = &src; 2275 } 2276 2277 ip6->ip6_src = *srcp; 2278 ip6->ip6_flow = 0; 2279 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2280 ip6->ip6_vfc |= IPV6_VERSION; 2281 ip6->ip6_nxt = IPPROTO_ICMPV6; 2282 if (outif) 2283 ip6->ip6_hlim = ND_IFINFO(outif)->chlim; 2284 else if (m->m_pkthdr.rcvif) { 2285 /* XXX: This may not be the outgoing interface */ 2286 ip6->ip6_hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim; 2287 } else 2288 ip6->ip6_hlim = V_ip6_defhlim; 2289 2290 icmp6->icmp6_cksum = 0; 2291 icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2292 sizeof(struct ip6_hdr), plen); 2293 2294 /* 2295 * XXX option handling 2296 */ 2297 2298 m->m_flags &= ~(M_BCAST|M_MCAST); 2299 2300 m_addr_changed(m); 2301 2302 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2303 if (outif) 2304 icmp6_ifoutstat_inc(outif, type, code); 2305 2306 if (ia != NULL) 2307 ifa_free(&ia->ia_ifa); 2308 return; 2309 2310 bad: 2311 if (ia != NULL) 2312 ifa_free(&ia->ia_ifa); 2313 m_freem(m); 2314 return; 2315 } 2316 2317 void 2318 icmp6_fasttimo(void) 2319 { 2320 2321 mld_fasttimo(); 2322 } 2323 2324 void 2325 icmp6_slowtimo(void) 2326 { 2327 2328 mld_slowtimo(); 2329 } 2330 2331 static const char * 2332 icmp6_redirect_diag(struct in6_addr *src6, struct in6_addr *dst6, 2333 struct in6_addr *tgt6) 2334 { 2335 static char buf[1024]; 2336 char ip6bufs[INET6_ADDRSTRLEN]; 2337 char ip6bufd[INET6_ADDRSTRLEN]; 2338 char ip6buft[INET6_ADDRSTRLEN]; 2339 snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)", 2340 ip6_sprintf(ip6bufs, src6), ip6_sprintf(ip6bufd, dst6), 2341 ip6_sprintf(ip6buft, tgt6)); 2342 return buf; 2343 } 2344 2345 void 2346 icmp6_redirect_input(struct mbuf *m, int off) 2347 { 2348 struct ifnet *ifp; 2349 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 2350 struct nd_redirect *nd_rd; 2351 int icmp6len = ntohs(ip6->ip6_plen); 2352 char *lladdr = NULL; 2353 int lladdrlen = 0; 2354 struct rtentry *rt = NULL; 2355 int is_router; 2356 int is_onlink; 2357 struct in6_addr src6 = ip6->ip6_src; 2358 struct in6_addr redtgt6; 2359 struct in6_addr reddst6; 2360 union nd_opts ndopts; 2361 char ip6buf[INET6_ADDRSTRLEN]; 2362 2363 M_ASSERTPKTHDR(m); 2364 KASSERT(m->m_pkthdr.rcvif != NULL, ("%s: no rcvif", __func__)); 2365 2366 ifp = m->m_pkthdr.rcvif; 2367 2368 /* XXX if we are router, we don't update route by icmp6 redirect */ 2369 if (V_ip6_forwarding) 2370 goto freeit; 2371 if (!V_icmp6_rediraccept) 2372 goto freeit; 2373 2374 #ifndef PULLDOWN_TEST 2375 IP6_EXTHDR_CHECK(m, off, icmp6len,); 2376 nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off); 2377 #else 2378 IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len); 2379 if (nd_rd == NULL) { 2380 ICMP6STAT_INC(icp6s_tooshort); 2381 return; 2382 } 2383 #endif 2384 redtgt6 = nd_rd->nd_rd_target; 2385 reddst6 = nd_rd->nd_rd_dst; 2386 2387 if (in6_setscope(&redtgt6, m->m_pkthdr.rcvif, NULL) || 2388 in6_setscope(&reddst6, m->m_pkthdr.rcvif, NULL)) { 2389 goto freeit; 2390 } 2391 2392 /* validation */ 2393 if (!IN6_IS_ADDR_LINKLOCAL(&src6)) { 2394 nd6log((LOG_ERR, 2395 "ICMP6 redirect sent from %s rejected; " 2396 "must be from linklocal\n", 2397 ip6_sprintf(ip6buf, &src6))); 2398 goto bad; 2399 } 2400 if (ip6->ip6_hlim != 255) { 2401 nd6log((LOG_ERR, 2402 "ICMP6 redirect sent from %s rejected; " 2403 "hlim=%d (must be 255)\n", 2404 ip6_sprintf(ip6buf, &src6), ip6->ip6_hlim)); 2405 goto bad; 2406 } 2407 { 2408 /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */ 2409 struct sockaddr_in6 sin6; 2410 struct in6_addr *gw6; 2411 2412 bzero(&sin6, sizeof(sin6)); 2413 sin6.sin6_family = AF_INET6; 2414 sin6.sin6_len = sizeof(struct sockaddr_in6); 2415 bcopy(&reddst6, &sin6.sin6_addr, sizeof(reddst6)); 2416 rt = in6_rtalloc1((struct sockaddr *)&sin6, 0, 0UL, RT_DEFAULT_FIB); 2417 if (rt) { 2418 if (rt->rt_gateway == NULL || 2419 rt->rt_gateway->sa_family != AF_INET6) { 2420 RTFREE_LOCKED(rt); 2421 nd6log((LOG_ERR, 2422 "ICMP6 redirect rejected; no route " 2423 "with inet6 gateway found for redirect dst: %s\n", 2424 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2425 goto bad; 2426 } 2427 2428 gw6 = &(((struct sockaddr_in6 *)rt->rt_gateway)->sin6_addr); 2429 if (bcmp(&src6, gw6, sizeof(struct in6_addr)) != 0) { 2430 RTFREE_LOCKED(rt); 2431 nd6log((LOG_ERR, 2432 "ICMP6 redirect rejected; " 2433 "not equal to gw-for-src=%s (must be same): " 2434 "%s\n", 2435 ip6_sprintf(ip6buf, gw6), 2436 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2437 goto bad; 2438 } 2439 } else { 2440 nd6log((LOG_ERR, 2441 "ICMP6 redirect rejected; " 2442 "no route found for redirect dst: %s\n", 2443 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2444 goto bad; 2445 } 2446 RTFREE_LOCKED(rt); 2447 rt = NULL; 2448 } 2449 if (IN6_IS_ADDR_MULTICAST(&reddst6)) { 2450 nd6log((LOG_ERR, 2451 "ICMP6 redirect rejected; " 2452 "redirect dst must be unicast: %s\n", 2453 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2454 goto bad; 2455 } 2456 2457 is_router = is_onlink = 0; 2458 if (IN6_IS_ADDR_LINKLOCAL(&redtgt6)) 2459 is_router = 1; /* router case */ 2460 if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0) 2461 is_onlink = 1; /* on-link destination case */ 2462 if (!is_router && !is_onlink) { 2463 nd6log((LOG_ERR, 2464 "ICMP6 redirect rejected; " 2465 "neither router case nor onlink case: %s\n", 2466 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2467 goto bad; 2468 } 2469 /* validation passed */ 2470 2471 icmp6len -= sizeof(*nd_rd); 2472 nd6_option_init(nd_rd + 1, icmp6len, &ndopts); 2473 if (nd6_options(&ndopts) < 0) { 2474 nd6log((LOG_INFO, "%s: invalid ND option, rejected: %s\n", 2475 __func__, icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2476 /* nd6_options have incremented stats */ 2477 goto freeit; 2478 } 2479 2480 if (ndopts.nd_opts_tgt_lladdr) { 2481 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 2482 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 2483 } 2484 2485 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 2486 nd6log((LOG_INFO, "%s: lladdrlen mismatch for %s " 2487 "(if %d, icmp6 packet %d): %s\n", 2488 __func__, ip6_sprintf(ip6buf, &redtgt6), 2489 ifp->if_addrlen, lladdrlen - 2, 2490 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2491 goto bad; 2492 } 2493 2494 /* RFC 2461 8.3 */ 2495 nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT, 2496 is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER); 2497 2498 if (!is_onlink) { /* better router case. perform rtredirect. */ 2499 /* perform rtredirect */ 2500 struct sockaddr_in6 sdst; 2501 struct sockaddr_in6 sgw; 2502 struct sockaddr_in6 ssrc; 2503 u_int fibnum; 2504 2505 bzero(&sdst, sizeof(sdst)); 2506 bzero(&sgw, sizeof(sgw)); 2507 bzero(&ssrc, sizeof(ssrc)); 2508 sdst.sin6_family = sgw.sin6_family = ssrc.sin6_family = AF_INET6; 2509 sdst.sin6_len = sgw.sin6_len = ssrc.sin6_len = 2510 sizeof(struct sockaddr_in6); 2511 bcopy(&redtgt6, &sgw.sin6_addr, sizeof(struct in6_addr)); 2512 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr)); 2513 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr)); 2514 for (fibnum = 0; fibnum < rt_numfibs; fibnum++) 2515 in6_rtredirect((struct sockaddr *)&sdst, 2516 (struct sockaddr *)&sgw, (struct sockaddr *)NULL, 2517 RTF_GATEWAY | RTF_HOST, (struct sockaddr *)&ssrc, 2518 fibnum); 2519 } 2520 /* finally update cached route in each socket via pfctlinput */ 2521 { 2522 struct sockaddr_in6 sdst; 2523 2524 bzero(&sdst, sizeof(sdst)); 2525 sdst.sin6_family = AF_INET6; 2526 sdst.sin6_len = sizeof(struct sockaddr_in6); 2527 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr)); 2528 pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst); 2529 #ifdef IPSEC 2530 key_sa_routechange((struct sockaddr *)&sdst); 2531 #endif /* IPSEC */ 2532 } 2533 2534 freeit: 2535 m_freem(m); 2536 return; 2537 2538 bad: 2539 ICMP6STAT_INC(icp6s_badredirect); 2540 m_freem(m); 2541 } 2542 2543 void 2544 icmp6_redirect_output(struct mbuf *m0, struct rtentry *rt) 2545 { 2546 struct ifnet *ifp; /* my outgoing interface */ 2547 struct in6_addr *ifp_ll6; 2548 struct in6_addr *router_ll6; 2549 struct ip6_hdr *sip6; /* m0 as struct ip6_hdr */ 2550 struct mbuf *m = NULL; /* newly allocated one */ 2551 struct m_tag *mtag; 2552 struct ip6_hdr *ip6; /* m as struct ip6_hdr */ 2553 struct nd_redirect *nd_rd; 2554 struct llentry *ln = NULL; 2555 size_t maxlen; 2556 u_char *p; 2557 struct ifnet *outif = NULL; 2558 struct sockaddr_in6 src_sa; 2559 2560 icmp6_errcount(ND_REDIRECT, 0); 2561 2562 /* if we are not router, we don't send icmp6 redirect */ 2563 if (!V_ip6_forwarding) 2564 goto fail; 2565 2566 /* sanity check */ 2567 if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp)) 2568 goto fail; 2569 2570 /* 2571 * Address check: 2572 * the source address must identify a neighbor, and 2573 * the destination address must not be a multicast address 2574 * [RFC 2461, sec 8.2] 2575 */ 2576 sip6 = mtod(m0, struct ip6_hdr *); 2577 bzero(&src_sa, sizeof(src_sa)); 2578 src_sa.sin6_family = AF_INET6; 2579 src_sa.sin6_len = sizeof(src_sa); 2580 src_sa.sin6_addr = sip6->ip6_src; 2581 if (nd6_is_addr_neighbor(&src_sa, ifp) == 0) 2582 goto fail; 2583 if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst)) 2584 goto fail; /* what should we do here? */ 2585 2586 /* rate limit */ 2587 if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0)) 2588 goto fail; 2589 2590 /* 2591 * Since we are going to append up to 1280 bytes (= IPV6_MMTU), 2592 * we almost always ask for an mbuf cluster for simplicity. 2593 * (MHLEN < IPV6_MMTU is almost always true) 2594 */ 2595 #if IPV6_MMTU >= MCLBYTES 2596 # error assumption failed about IPV6_MMTU and MCLBYTES 2597 #endif 2598 MGETHDR(m, M_DONTWAIT, MT_HEADER); 2599 if (m && IPV6_MMTU >= MHLEN) 2600 MCLGET(m, M_DONTWAIT); 2601 if (!m) 2602 goto fail; 2603 M_SETFIB(m, rt->rt_fibnum); 2604 m->m_pkthdr.rcvif = NULL; 2605 m->m_len = 0; 2606 maxlen = M_TRAILINGSPACE(m); 2607 maxlen = min(IPV6_MMTU, maxlen); 2608 /* just for safety */ 2609 if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) + 2610 ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) { 2611 goto fail; 2612 } 2613 2614 { 2615 /* get ip6 linklocal address for ifp(my outgoing interface). */ 2616 struct in6_ifaddr *ia; 2617 if ((ia = in6ifa_ifpforlinklocal(ifp, 2618 IN6_IFF_NOTREADY| 2619 IN6_IFF_ANYCAST)) == NULL) 2620 goto fail; 2621 ifp_ll6 = &ia->ia_addr.sin6_addr; 2622 /* XXXRW: reference released prematurely. */ 2623 ifa_free(&ia->ia_ifa); 2624 } 2625 2626 /* get ip6 linklocal address for the router. */ 2627 if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) { 2628 struct sockaddr_in6 *sin6; 2629 sin6 = (struct sockaddr_in6 *)rt->rt_gateway; 2630 router_ll6 = &sin6->sin6_addr; 2631 if (!IN6_IS_ADDR_LINKLOCAL(router_ll6)) 2632 router_ll6 = (struct in6_addr *)NULL; 2633 } else 2634 router_ll6 = (struct in6_addr *)NULL; 2635 2636 /* ip6 */ 2637 ip6 = mtod(m, struct ip6_hdr *); 2638 ip6->ip6_flow = 0; 2639 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2640 ip6->ip6_vfc |= IPV6_VERSION; 2641 /* ip6->ip6_plen will be set later */ 2642 ip6->ip6_nxt = IPPROTO_ICMPV6; 2643 ip6->ip6_hlim = 255; 2644 /* ip6->ip6_src must be linklocal addr for my outgoing if. */ 2645 bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr)); 2646 bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr)); 2647 2648 /* ND Redirect */ 2649 nd_rd = (struct nd_redirect *)(ip6 + 1); 2650 nd_rd->nd_rd_type = ND_REDIRECT; 2651 nd_rd->nd_rd_code = 0; 2652 nd_rd->nd_rd_reserved = 0; 2653 if (rt->rt_flags & RTF_GATEWAY) { 2654 /* 2655 * nd_rd->nd_rd_target must be a link-local address in 2656 * better router cases. 2657 */ 2658 if (!router_ll6) 2659 goto fail; 2660 bcopy(router_ll6, &nd_rd->nd_rd_target, 2661 sizeof(nd_rd->nd_rd_target)); 2662 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2663 sizeof(nd_rd->nd_rd_dst)); 2664 } else { 2665 /* make sure redtgt == reddst */ 2666 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target, 2667 sizeof(nd_rd->nd_rd_target)); 2668 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2669 sizeof(nd_rd->nd_rd_dst)); 2670 } 2671 2672 p = (u_char *)(nd_rd + 1); 2673 2674 if (!router_ll6) 2675 goto nolladdropt; 2676 2677 { 2678 /* target lladdr option */ 2679 int len; 2680 struct nd_opt_hdr *nd_opt; 2681 char *lladdr; 2682 2683 IF_AFDATA_RLOCK(ifp); 2684 ln = nd6_lookup(router_ll6, 0, ifp); 2685 IF_AFDATA_RUNLOCK(ifp); 2686 if (ln == NULL) 2687 goto nolladdropt; 2688 2689 len = sizeof(*nd_opt) + ifp->if_addrlen; 2690 len = (len + 7) & ~7; /* round by 8 */ 2691 /* safety check */ 2692 if (len + (p - (u_char *)ip6) > maxlen) 2693 goto nolladdropt; 2694 2695 if (ln->la_flags & LLE_VALID) { 2696 nd_opt = (struct nd_opt_hdr *)p; 2697 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 2698 nd_opt->nd_opt_len = len >> 3; 2699 lladdr = (char *)(nd_opt + 1); 2700 bcopy(&ln->ll_addr, lladdr, ifp->if_addrlen); 2701 p += len; 2702 } 2703 } 2704 nolladdropt: 2705 if (ln != NULL) 2706 LLE_RUNLOCK(ln); 2707 2708 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2709 2710 /* just to be safe */ 2711 #ifdef M_DECRYPTED /*not openbsd*/ 2712 if (m0->m_flags & M_DECRYPTED) 2713 goto noredhdropt; 2714 #endif 2715 if (p - (u_char *)ip6 > maxlen) 2716 goto noredhdropt; 2717 2718 { 2719 /* redirected header option */ 2720 int len; 2721 struct nd_opt_rd_hdr *nd_opt_rh; 2722 2723 /* 2724 * compute the maximum size for icmp6 redirect header option. 2725 * XXX room for auth header? 2726 */ 2727 len = maxlen - (p - (u_char *)ip6); 2728 len &= ~7; 2729 2730 /* This is just for simplicity. */ 2731 if (m0->m_pkthdr.len != m0->m_len) { 2732 if (m0->m_next) { 2733 m_freem(m0->m_next); 2734 m0->m_next = NULL; 2735 } 2736 m0->m_pkthdr.len = m0->m_len; 2737 } 2738 2739 /* 2740 * Redirected header option spec (RFC2461 4.6.3) talks nothing 2741 * about padding/truncate rule for the original IP packet. 2742 * From the discussion on IPv6imp in Feb 1999, 2743 * the consensus was: 2744 * - "attach as much as possible" is the goal 2745 * - pad if not aligned (original size can be guessed by 2746 * original ip6 header) 2747 * Following code adds the padding if it is simple enough, 2748 * and truncates if not. 2749 */ 2750 if (m0->m_next || m0->m_pkthdr.len != m0->m_len) 2751 panic("assumption failed in %s:%d", __FILE__, 2752 __LINE__); 2753 2754 if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) { 2755 /* not enough room, truncate */ 2756 m0->m_pkthdr.len = m0->m_len = len - 2757 sizeof(*nd_opt_rh); 2758 } else { 2759 /* enough room, pad or truncate */ 2760 size_t extra; 2761 2762 extra = m0->m_pkthdr.len % 8; 2763 if (extra) { 2764 /* pad if easy enough, truncate if not */ 2765 if (8 - extra <= M_TRAILINGSPACE(m0)) { 2766 /* pad */ 2767 m0->m_len += (8 - extra); 2768 m0->m_pkthdr.len += (8 - extra); 2769 } else { 2770 /* truncate */ 2771 m0->m_pkthdr.len -= extra; 2772 m0->m_len -= extra; 2773 } 2774 } 2775 len = m0->m_pkthdr.len + sizeof(*nd_opt_rh); 2776 m0->m_pkthdr.len = m0->m_len = len - 2777 sizeof(*nd_opt_rh); 2778 } 2779 2780 nd_opt_rh = (struct nd_opt_rd_hdr *)p; 2781 bzero(nd_opt_rh, sizeof(*nd_opt_rh)); 2782 nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER; 2783 nd_opt_rh->nd_opt_rh_len = len >> 3; 2784 p += sizeof(*nd_opt_rh); 2785 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2786 2787 /* connect m0 to m */ 2788 m_tag_delete_chain(m0, NULL); 2789 m0->m_flags &= ~M_PKTHDR; 2790 m->m_next = m0; 2791 m->m_pkthdr.len = m->m_len + m0->m_len; 2792 m0 = NULL; 2793 } 2794 noredhdropt:; 2795 if (m0) { 2796 m_freem(m0); 2797 m0 = NULL; 2798 } 2799 2800 /* XXX: clear embedded link IDs in the inner header */ 2801 in6_clearscope(&sip6->ip6_src); 2802 in6_clearscope(&sip6->ip6_dst); 2803 in6_clearscope(&nd_rd->nd_rd_target); 2804 in6_clearscope(&nd_rd->nd_rd_dst); 2805 2806 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr)); 2807 2808 nd_rd->nd_rd_cksum = 0; 2809 nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2810 sizeof(*ip6), ntohs(ip6->ip6_plen)); 2811 2812 if (send_sendso_input_hook != NULL) { 2813 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, sizeof(unsigned short), 2814 M_NOWAIT); 2815 if (mtag == NULL) 2816 goto fail; 2817 *(unsigned short *)(mtag + 1) = nd_rd->nd_rd_type; 2818 m_tag_prepend(m, mtag); 2819 } 2820 2821 /* send the packet to outside... */ 2822 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2823 if (outif) { 2824 icmp6_ifstat_inc(outif, ifs6_out_msg); 2825 icmp6_ifstat_inc(outif, ifs6_out_redirect); 2826 } 2827 ICMP6STAT_INC(icp6s_outhist[ND_REDIRECT]); 2828 2829 return; 2830 2831 fail: 2832 if (m) 2833 m_freem(m); 2834 if (m0) 2835 m_freem(m0); 2836 } 2837 2838 /* 2839 * ICMPv6 socket option processing. 2840 */ 2841 int 2842 icmp6_ctloutput(struct socket *so, struct sockopt *sopt) 2843 { 2844 int error = 0; 2845 int optlen; 2846 struct inpcb *inp = sotoinpcb(so); 2847 int level, op, optname; 2848 2849 if (sopt) { 2850 level = sopt->sopt_level; 2851 op = sopt->sopt_dir; 2852 optname = sopt->sopt_name; 2853 optlen = sopt->sopt_valsize; 2854 } else 2855 level = op = optname = optlen = 0; 2856 2857 if (level != IPPROTO_ICMPV6) { 2858 return EINVAL; 2859 } 2860 2861 switch (op) { 2862 case PRCO_SETOPT: 2863 switch (optname) { 2864 case ICMP6_FILTER: 2865 { 2866 struct icmp6_filter ic6f; 2867 2868 if (optlen != sizeof(ic6f)) { 2869 error = EMSGSIZE; 2870 break; 2871 } 2872 error = sooptcopyin(sopt, &ic6f, optlen, optlen); 2873 if (error == 0) { 2874 INP_WLOCK(inp); 2875 *inp->in6p_icmp6filt = ic6f; 2876 INP_WUNLOCK(inp); 2877 } 2878 break; 2879 } 2880 2881 default: 2882 error = ENOPROTOOPT; 2883 break; 2884 } 2885 break; 2886 2887 case PRCO_GETOPT: 2888 switch (optname) { 2889 case ICMP6_FILTER: 2890 { 2891 struct icmp6_filter ic6f; 2892 2893 INP_RLOCK(inp); 2894 ic6f = *inp->in6p_icmp6filt; 2895 INP_RUNLOCK(inp); 2896 error = sooptcopyout(sopt, &ic6f, sizeof(ic6f)); 2897 break; 2898 } 2899 2900 default: 2901 error = ENOPROTOOPT; 2902 break; 2903 } 2904 break; 2905 } 2906 2907 return (error); 2908 } 2909 2910 /* 2911 * Perform rate limit check. 2912 * Returns 0 if it is okay to send the icmp6 packet. 2913 * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate 2914 * limitation. 2915 * 2916 * XXX per-destination/type check necessary? 2917 * 2918 * dst - not used at this moment 2919 * type - not used at this moment 2920 * code - not used at this moment 2921 */ 2922 static int 2923 icmp6_ratelimit(const struct in6_addr *dst, const int type, 2924 const int code) 2925 { 2926 int ret; 2927 2928 ret = 0; /* okay to send */ 2929 2930 /* PPS limit */ 2931 if (!ppsratecheck(&V_icmp6errppslim_last, &V_icmp6errpps_count, 2932 V_icmp6errppslim)) { 2933 /* The packet is subject to rate limit */ 2934 ret++; 2935 } 2936 2937 return ret; 2938 }
Cache object: cad3dccf0902741a077f730d643f7ea6
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