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/11.0/sys/netinet6/icmp6.c 299829 2016-05-15 03:22:13Z markj $"); 65 66 #define MBUF_PRIVATE /* XXXRW: Optimisation tries to avoid M_EXT mbufs */ 67 68 #include "opt_inet.h" 69 #include "opt_inet6.h" 70 71 #include <sys/param.h> 72 #include <sys/domain.h> 73 #include <sys/jail.h> 74 #include <sys/kernel.h> 75 #include <sys/lock.h> 76 #include <sys/malloc.h> 77 #include <sys/mbuf.h> 78 #include <sys/proc.h> 79 #include <sys/protosw.h> 80 #include <sys/signalvar.h> 81 #include <sys/socket.h> 82 #include <sys/socketvar.h> 83 #include <sys/sx.h> 84 #include <sys/syslog.h> 85 #include <sys/systm.h> 86 #include <sys/time.h> 87 88 #include <net/if.h> 89 #include <net/if_var.h> 90 #include <net/if_dl.h> 91 #include <net/if_llatbl.h> 92 #include <net/if_types.h> 93 #include <net/route.h> 94 #include <net/vnet.h> 95 96 #include <netinet/in.h> 97 #include <netinet/in_pcb.h> 98 #include <netinet/in_var.h> 99 #include <netinet/ip6.h> 100 #include <netinet/icmp6.h> 101 #include <netinet/tcp_var.h> 102 103 #include <netinet6/in6_fib.h> 104 #include <netinet6/in6_ifattach.h> 105 #include <netinet6/in6_pcb.h> 106 #include <netinet6/ip6protosw.h> 107 #include <netinet6/ip6_var.h> 108 #include <netinet6/scope6_var.h> 109 #include <netinet6/mld6_var.h> 110 #include <netinet6/nd6.h> 111 #include <netinet6/send.h> 112 113 extern struct domain inet6domain; 114 115 VNET_PCPUSTAT_DEFINE(struct icmp6stat, icmp6stat); 116 VNET_PCPUSTAT_SYSINIT(icmp6stat); 117 118 #ifdef VIMAGE 119 VNET_PCPUSTAT_SYSUNINIT(icmp6stat); 120 #endif /* VIMAGE */ 121 122 VNET_DECLARE(struct inpcbinfo, ripcbinfo); 123 VNET_DECLARE(struct inpcbhead, ripcb); 124 VNET_DECLARE(int, icmp6errppslim); 125 static VNET_DEFINE(int, icmp6errpps_count) = 0; 126 static VNET_DEFINE(struct timeval, icmp6errppslim_last); 127 VNET_DECLARE(int, icmp6_nodeinfo); 128 129 #define V_ripcbinfo VNET(ripcbinfo) 130 #define V_ripcb VNET(ripcb) 131 #define V_icmp6errppslim VNET(icmp6errppslim) 132 #define V_icmp6errpps_count VNET(icmp6errpps_count) 133 #define V_icmp6errppslim_last VNET(icmp6errppslim_last) 134 #define V_icmp6_nodeinfo VNET(icmp6_nodeinfo) 135 136 static void icmp6_errcount(int, int); 137 static int icmp6_rip6_input(struct mbuf **, int); 138 static int icmp6_ratelimit(const struct in6_addr *, const int, const int); 139 static const char *icmp6_redirect_diag(struct in6_addr *, 140 struct in6_addr *, struct in6_addr *); 141 static struct mbuf *ni6_input(struct mbuf *, int); 142 static struct mbuf *ni6_nametodns(const char *, int, int); 143 static int ni6_dnsmatch(const char *, int, const char *, int); 144 static int ni6_addrs(struct icmp6_nodeinfo *, struct mbuf *, 145 struct ifnet **, struct in6_addr *); 146 static int ni6_store_addrs(struct icmp6_nodeinfo *, struct icmp6_nodeinfo *, 147 struct ifnet *, int); 148 static int icmp6_notify_error(struct mbuf **, int, int, int); 149 150 /* 151 * Kernel module interface for updating icmp6stat. The argument is an index 152 * into icmp6stat treated as an array of u_quad_t. While this encodes the 153 * general layout of icmp6stat into the caller, it doesn't encode its 154 * location, so that future changes to add, for example, per-CPU stats 155 * support won't cause binary compatibility problems for kernel modules. 156 */ 157 void 158 kmod_icmp6stat_inc(int statnum) 159 { 160 161 counter_u64_add(VNET(icmp6stat)[statnum], 1); 162 } 163 164 static void 165 icmp6_errcount(int type, int code) 166 { 167 switch (type) { 168 case ICMP6_DST_UNREACH: 169 switch (code) { 170 case ICMP6_DST_UNREACH_NOROUTE: 171 ICMP6STAT_INC(icp6s_odst_unreach_noroute); 172 return; 173 case ICMP6_DST_UNREACH_ADMIN: 174 ICMP6STAT_INC(icp6s_odst_unreach_admin); 175 return; 176 case ICMP6_DST_UNREACH_BEYONDSCOPE: 177 ICMP6STAT_INC(icp6s_odst_unreach_beyondscope); 178 return; 179 case ICMP6_DST_UNREACH_ADDR: 180 ICMP6STAT_INC(icp6s_odst_unreach_addr); 181 return; 182 case ICMP6_DST_UNREACH_NOPORT: 183 ICMP6STAT_INC(icp6s_odst_unreach_noport); 184 return; 185 } 186 break; 187 case ICMP6_PACKET_TOO_BIG: 188 ICMP6STAT_INC(icp6s_opacket_too_big); 189 return; 190 case ICMP6_TIME_EXCEEDED: 191 switch (code) { 192 case ICMP6_TIME_EXCEED_TRANSIT: 193 ICMP6STAT_INC(icp6s_otime_exceed_transit); 194 return; 195 case ICMP6_TIME_EXCEED_REASSEMBLY: 196 ICMP6STAT_INC(icp6s_otime_exceed_reassembly); 197 return; 198 } 199 break; 200 case ICMP6_PARAM_PROB: 201 switch (code) { 202 case ICMP6_PARAMPROB_HEADER: 203 ICMP6STAT_INC(icp6s_oparamprob_header); 204 return; 205 case ICMP6_PARAMPROB_NEXTHEADER: 206 ICMP6STAT_INC(icp6s_oparamprob_nextheader); 207 return; 208 case ICMP6_PARAMPROB_OPTION: 209 ICMP6STAT_INC(icp6s_oparamprob_option); 210 return; 211 } 212 break; 213 case ND_REDIRECT: 214 ICMP6STAT_INC(icp6s_oredirect); 215 return; 216 } 217 ICMP6STAT_INC(icp6s_ounknown); 218 } 219 220 /* 221 * A wrapper function for icmp6_error() necessary when the erroneous packet 222 * may not contain enough scope zone information. 223 */ 224 void 225 icmp6_error2(struct mbuf *m, int type, int code, int param, 226 struct ifnet *ifp) 227 { 228 struct ip6_hdr *ip6; 229 230 if (ifp == NULL) 231 return; 232 233 #ifndef PULLDOWN_TEST 234 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), ); 235 #else 236 if (m->m_len < sizeof(struct ip6_hdr)) { 237 m = m_pullup(m, sizeof(struct ip6_hdr)); 238 if (m == NULL) 239 return; 240 } 241 #endif 242 243 ip6 = mtod(m, struct ip6_hdr *); 244 245 if (in6_setscope(&ip6->ip6_src, ifp, NULL) != 0) 246 return; 247 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0) 248 return; 249 250 icmp6_error(m, type, code, param); 251 } 252 253 /* 254 * Generate an error packet of type error in response to bad IP6 packet. 255 */ 256 void 257 icmp6_error(struct mbuf *m, int type, int code, int param) 258 { 259 struct ip6_hdr *oip6, *nip6; 260 struct icmp6_hdr *icmp6; 261 u_int preplen; 262 int off; 263 int nxt; 264 265 ICMP6STAT_INC(icp6s_error); 266 267 /* count per-type-code statistics */ 268 icmp6_errcount(type, code); 269 270 #ifdef M_DECRYPTED /*not openbsd*/ 271 if (m->m_flags & M_DECRYPTED) { 272 ICMP6STAT_INC(icp6s_canterror); 273 goto freeit; 274 } 275 #endif 276 277 #ifndef PULLDOWN_TEST 278 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), ); 279 #else 280 if (m->m_len < sizeof(struct ip6_hdr)) { 281 m = m_pullup(m, sizeof(struct ip6_hdr)); 282 if (m == NULL) 283 return; 284 } 285 #endif 286 oip6 = mtod(m, struct ip6_hdr *); 287 288 /* 289 * If the destination address of the erroneous packet is a multicast 290 * address, or the packet was sent using link-layer multicast, 291 * we should basically suppress sending an error (RFC 2463, Section 292 * 2.4). 293 * We have two exceptions (the item e.2 in that section): 294 * - the Packet Too Big message can be sent for path MTU discovery. 295 * - the Parameter Problem Message that can be allowed an icmp6 error 296 * in the option type field. This check has been done in 297 * ip6_unknown_opt(), so we can just check the type and code. 298 */ 299 if ((m->m_flags & (M_BCAST|M_MCAST) || 300 IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) && 301 (type != ICMP6_PACKET_TOO_BIG && 302 (type != ICMP6_PARAM_PROB || 303 code != ICMP6_PARAMPROB_OPTION))) 304 goto freeit; 305 306 /* 307 * RFC 2463, 2.4 (e.5): source address check. 308 * XXX: the case of anycast source? 309 */ 310 if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) || 311 IN6_IS_ADDR_MULTICAST(&oip6->ip6_src)) 312 goto freeit; 313 314 /* 315 * If we are about to send ICMPv6 against ICMPv6 error/redirect, 316 * don't do it. 317 */ 318 nxt = -1; 319 off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt); 320 if (off >= 0 && nxt == IPPROTO_ICMPV6) { 321 struct icmp6_hdr *icp; 322 323 #ifndef PULLDOWN_TEST 324 IP6_EXTHDR_CHECK(m, 0, off + sizeof(struct icmp6_hdr), ); 325 icp = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 326 #else 327 IP6_EXTHDR_GET(icp, struct icmp6_hdr *, m, off, 328 sizeof(*icp)); 329 if (icp == NULL) { 330 ICMP6STAT_INC(icp6s_tooshort); 331 return; 332 } 333 #endif 334 if (icp->icmp6_type < ICMP6_ECHO_REQUEST || 335 icp->icmp6_type == ND_REDIRECT) { 336 /* 337 * ICMPv6 error 338 * Special case: for redirect (which is 339 * informational) we must not send icmp6 error. 340 */ 341 ICMP6STAT_INC(icp6s_canterror); 342 goto freeit; 343 } else { 344 /* ICMPv6 informational - send the error */ 345 } 346 } else { 347 /* non-ICMPv6 - send the error */ 348 } 349 350 oip6 = mtod(m, struct ip6_hdr *); /* adjust pointer */ 351 352 /* Finally, do rate limitation check. */ 353 if (icmp6_ratelimit(&oip6->ip6_src, type, code)) { 354 ICMP6STAT_INC(icp6s_toofreq); 355 goto freeit; 356 } 357 358 /* 359 * OK, ICMP6 can be generated. 360 */ 361 362 if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN) 363 m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len); 364 365 preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 366 M_PREPEND(m, preplen, M_NOWAIT); /* FIB is also copied over. */ 367 if (m == NULL) { 368 nd6log((LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__)); 369 return; 370 } 371 372 nip6 = mtod(m, struct ip6_hdr *); 373 nip6->ip6_src = oip6->ip6_src; 374 nip6->ip6_dst = oip6->ip6_dst; 375 376 in6_clearscope(&oip6->ip6_src); 377 in6_clearscope(&oip6->ip6_dst); 378 379 icmp6 = (struct icmp6_hdr *)(nip6 + 1); 380 icmp6->icmp6_type = type; 381 icmp6->icmp6_code = code; 382 icmp6->icmp6_pptr = htonl((u_int32_t)param); 383 384 /* 385 * icmp6_reflect() is designed to be in the input path. 386 * icmp6_error() can be called from both input and output path, 387 * and if we are in output path rcvif could contain bogus value. 388 * clear m->m_pkthdr.rcvif for safety, we should have enough scope 389 * information in ip header (nip6). 390 */ 391 m->m_pkthdr.rcvif = NULL; 392 393 ICMP6STAT_INC(icp6s_outhist[type]); 394 icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */ 395 396 return; 397 398 freeit: 399 /* 400 * If we can't tell whether or not we can generate ICMP6, free it. 401 */ 402 m_freem(m); 403 } 404 405 /* 406 * Process a received ICMP6 message. 407 */ 408 int 409 icmp6_input(struct mbuf **mp, int *offp, int proto) 410 { 411 struct mbuf *m = *mp, *n; 412 struct ifnet *ifp; 413 struct ip6_hdr *ip6, *nip6; 414 struct icmp6_hdr *icmp6, *nicmp6; 415 int off = *offp; 416 int icmp6len = m->m_pkthdr.len - *offp; 417 int code, sum, noff; 418 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 419 int ip6len, error; 420 421 ifp = m->m_pkthdr.rcvif; 422 423 #ifndef PULLDOWN_TEST 424 IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_hdr), IPPROTO_DONE); 425 /* m might change if M_LOOP. So, call mtod after this */ 426 #endif 427 428 /* 429 * Locate icmp6 structure in mbuf, and check 430 * that not corrupted and of at least minimum length 431 */ 432 433 ip6 = mtod(m, struct ip6_hdr *); 434 ip6len = sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen); 435 if (icmp6len < sizeof(struct icmp6_hdr)) { 436 ICMP6STAT_INC(icp6s_tooshort); 437 goto freeit; 438 } 439 440 /* 441 * Check multicast group membership. 442 * Note: SSM filters are not applied for ICMPv6 traffic. 443 */ 444 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 445 struct in6_multi *inm; 446 447 inm = in6m_lookup(ifp, &ip6->ip6_dst); 448 if (inm == NULL) { 449 IP6STAT_INC(ip6s_notmember); 450 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 451 goto freeit; 452 } 453 } 454 455 /* 456 * calculate the checksum 457 */ 458 #ifndef PULLDOWN_TEST 459 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off); 460 #else 461 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6)); 462 if (icmp6 == NULL) { 463 ICMP6STAT_INC(icp6s_tooshort); 464 return IPPROTO_DONE; 465 } 466 #endif 467 code = icmp6->icmp6_code; 468 469 if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) { 470 nd6log((LOG_ERR, 471 "ICMP6 checksum error(%d|%x) %s\n", 472 icmp6->icmp6_type, sum, 473 ip6_sprintf(ip6bufs, &ip6->ip6_src))); 474 ICMP6STAT_INC(icp6s_checksum); 475 goto freeit; 476 } 477 478 ICMP6STAT_INC(icp6s_inhist[icmp6->icmp6_type]); 479 icmp6_ifstat_inc(ifp, ifs6_in_msg); 480 if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK) 481 icmp6_ifstat_inc(ifp, ifs6_in_error); 482 483 switch (icmp6->icmp6_type) { 484 case ICMP6_DST_UNREACH: 485 icmp6_ifstat_inc(ifp, ifs6_in_dstunreach); 486 switch (code) { 487 case ICMP6_DST_UNREACH_NOROUTE: 488 code = PRC_UNREACH_NET; 489 break; 490 case ICMP6_DST_UNREACH_ADMIN: 491 icmp6_ifstat_inc(ifp, ifs6_in_adminprohib); 492 code = PRC_UNREACH_PROTOCOL; /* is this a good code? */ 493 break; 494 case ICMP6_DST_UNREACH_ADDR: 495 code = PRC_HOSTDEAD; 496 break; 497 case ICMP6_DST_UNREACH_BEYONDSCOPE: 498 /* I mean "source address was incorrect." */ 499 code = PRC_PARAMPROB; 500 break; 501 case ICMP6_DST_UNREACH_NOPORT: 502 code = PRC_UNREACH_PORT; 503 break; 504 default: 505 goto badcode; 506 } 507 goto deliver; 508 break; 509 510 case ICMP6_PACKET_TOO_BIG: 511 icmp6_ifstat_inc(ifp, ifs6_in_pkttoobig); 512 513 /* validation is made in icmp6_mtudisc_update */ 514 515 code = PRC_MSGSIZE; 516 517 /* 518 * Updating the path MTU will be done after examining 519 * intermediate extension headers. 520 */ 521 goto deliver; 522 break; 523 524 case ICMP6_TIME_EXCEEDED: 525 icmp6_ifstat_inc(ifp, ifs6_in_timeexceed); 526 switch (code) { 527 case ICMP6_TIME_EXCEED_TRANSIT: 528 code = PRC_TIMXCEED_INTRANS; 529 break; 530 case ICMP6_TIME_EXCEED_REASSEMBLY: 531 code = PRC_TIMXCEED_REASS; 532 break; 533 default: 534 goto badcode; 535 } 536 goto deliver; 537 break; 538 539 case ICMP6_PARAM_PROB: 540 icmp6_ifstat_inc(ifp, ifs6_in_paramprob); 541 switch (code) { 542 case ICMP6_PARAMPROB_NEXTHEADER: 543 code = PRC_UNREACH_PROTOCOL; 544 break; 545 case ICMP6_PARAMPROB_HEADER: 546 case ICMP6_PARAMPROB_OPTION: 547 code = PRC_PARAMPROB; 548 break; 549 default: 550 goto badcode; 551 } 552 goto deliver; 553 break; 554 555 case ICMP6_ECHO_REQUEST: 556 icmp6_ifstat_inc(ifp, ifs6_in_echo); 557 if (code != 0) 558 goto badcode; 559 if ((n = m_copy(m, 0, M_COPYALL)) == NULL) { 560 /* Give up remote */ 561 break; 562 } 563 if (!M_WRITABLE(n) 564 || n->m_len < off + sizeof(struct icmp6_hdr)) { 565 struct mbuf *n0 = n; 566 int n0len; 567 568 CTASSERT(sizeof(*nip6) + sizeof(*nicmp6) <= MHLEN); 569 n = m_gethdr(M_NOWAIT, n0->m_type); 570 if (n == NULL) { 571 /* Give up remote */ 572 m_freem(n0); 573 break; 574 } 575 576 m_move_pkthdr(n, n0); /* FIB copied. */ 577 n0len = n0->m_pkthdr.len; /* save for use below */ 578 /* 579 * Copy IPv6 and ICMPv6 only. 580 */ 581 nip6 = mtod(n, struct ip6_hdr *); 582 bcopy(ip6, nip6, sizeof(struct ip6_hdr)); 583 nicmp6 = (struct icmp6_hdr *)(nip6 + 1); 584 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr)); 585 noff = sizeof(struct ip6_hdr); 586 /* new mbuf contains only ipv6+icmpv6 headers */ 587 n->m_len = noff + sizeof(struct icmp6_hdr); 588 /* 589 * Adjust mbuf. ip6_plen will be adjusted in 590 * ip6_output(). 591 */ 592 m_adj(n0, off + sizeof(struct icmp6_hdr)); 593 /* recalculate complete packet size */ 594 n->m_pkthdr.len = n0len + (noff - off); 595 n->m_next = n0; 596 } else { 597 nip6 = mtod(n, struct ip6_hdr *); 598 IP6_EXTHDR_GET(nicmp6, struct icmp6_hdr *, n, off, 599 sizeof(*nicmp6)); 600 noff = off; 601 } 602 nicmp6->icmp6_type = ICMP6_ECHO_REPLY; 603 nicmp6->icmp6_code = 0; 604 if (n) { 605 ICMP6STAT_INC(icp6s_reflect); 606 ICMP6STAT_INC(icp6s_outhist[ICMP6_ECHO_REPLY]); 607 icmp6_reflect(n, noff); 608 } 609 break; 610 611 case ICMP6_ECHO_REPLY: 612 icmp6_ifstat_inc(ifp, ifs6_in_echoreply); 613 if (code != 0) 614 goto badcode; 615 break; 616 617 case MLD_LISTENER_QUERY: 618 case MLD_LISTENER_REPORT: 619 case MLD_LISTENER_DONE: 620 case MLDV2_LISTENER_REPORT: 621 /* 622 * Drop MLD traffic which is not link-local, has a hop limit 623 * of greater than 1 hop, or which does not have the 624 * IPv6 HBH Router Alert option. 625 * As IPv6 HBH options are stripped in ip6_input() we must 626 * check an mbuf header flag. 627 * XXX Should we also sanity check that these messages 628 * were directed to a link-local multicast prefix? 629 */ 630 if ((ip6->ip6_hlim != 1) || (m->m_flags & M_RTALERT_MLD) == 0) 631 goto freeit; 632 if (mld_input(m, off, icmp6len) != 0) 633 return (IPPROTO_DONE); 634 /* m stays. */ 635 break; 636 637 case ICMP6_WRUREQUEST: /* ICMP6_FQDN_QUERY */ 638 { 639 enum { WRU, FQDN } mode; 640 641 if (!V_icmp6_nodeinfo) 642 break; 643 644 if (icmp6len == sizeof(struct icmp6_hdr) + 4) 645 mode = WRU; 646 else if (icmp6len >= sizeof(struct icmp6_nodeinfo)) 647 mode = FQDN; 648 else 649 goto badlen; 650 651 if (mode == FQDN) { 652 #ifndef PULLDOWN_TEST 653 IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_nodeinfo), 654 IPPROTO_DONE); 655 #endif 656 n = m_copy(m, 0, M_COPYALL); 657 if (n) 658 n = ni6_input(n, off); 659 /* XXX meaningless if n == NULL */ 660 noff = sizeof(struct ip6_hdr); 661 } else { 662 struct prison *pr; 663 u_char *p; 664 int maxhlen, hlen; 665 666 /* 667 * XXX: this combination of flags is pointless, 668 * but should we keep this for compatibility? 669 */ 670 if ((V_icmp6_nodeinfo & (ICMP6_NODEINFO_FQDNOK | 671 ICMP6_NODEINFO_TMPADDROK)) != 672 (ICMP6_NODEINFO_FQDNOK | ICMP6_NODEINFO_TMPADDROK)) 673 break; 674 675 if (code != 0) 676 goto badcode; 677 678 CTASSERT(sizeof(*nip6) + sizeof(*nicmp6) + 4 <= MHLEN); 679 n = m_gethdr(M_NOWAIT, m->m_type); 680 if (n == NULL) { 681 /* Give up remote */ 682 break; 683 } 684 if (!m_dup_pkthdr(n, m, M_NOWAIT)) { 685 /* 686 * Previous code did a blind M_COPY_PKTHDR 687 * and said "just for rcvif". If true, then 688 * we could tolerate the dup failing (due to 689 * the deep copy of the tag chain). For now 690 * be conservative and just fail. 691 */ 692 m_free(n); 693 n = NULL; 694 } 695 maxhlen = M_TRAILINGSPACE(n) - 696 (sizeof(*nip6) + sizeof(*nicmp6) + 4); 697 pr = curthread->td_ucred->cr_prison; 698 mtx_lock(&pr->pr_mtx); 699 hlen = strlen(pr->pr_hostname); 700 if (maxhlen > hlen) 701 maxhlen = hlen; 702 /* 703 * Copy IPv6 and ICMPv6 only. 704 */ 705 nip6 = mtod(n, struct ip6_hdr *); 706 bcopy(ip6, nip6, sizeof(struct ip6_hdr)); 707 nicmp6 = (struct icmp6_hdr *)(nip6 + 1); 708 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr)); 709 p = (u_char *)(nicmp6 + 1); 710 bzero(p, 4); 711 /* meaningless TTL */ 712 bcopy(pr->pr_hostname, p + 4, maxhlen); 713 mtx_unlock(&pr->pr_mtx); 714 noff = sizeof(struct ip6_hdr); 715 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + 716 sizeof(struct icmp6_hdr) + 4 + maxhlen; 717 nicmp6->icmp6_type = ICMP6_WRUREPLY; 718 nicmp6->icmp6_code = 0; 719 } 720 if (n) { 721 ICMP6STAT_INC(icp6s_reflect); 722 ICMP6STAT_INC(icp6s_outhist[ICMP6_WRUREPLY]); 723 icmp6_reflect(n, noff); 724 } 725 break; 726 } 727 728 case ICMP6_WRUREPLY: 729 if (code != 0) 730 goto badcode; 731 break; 732 733 case ND_ROUTER_SOLICIT: 734 icmp6_ifstat_inc(ifp, ifs6_in_routersolicit); 735 if (code != 0) 736 goto badcode; 737 if (icmp6len < sizeof(struct nd_router_solicit)) 738 goto badlen; 739 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) { 740 /* give up local */ 741 742 /* Send incoming SeND packet to user space. */ 743 if (send_sendso_input_hook != NULL) { 744 IP6_EXTHDR_CHECK(m, off, 745 icmp6len, IPPROTO_DONE); 746 error = send_sendso_input_hook(m, ifp, 747 SND_IN, ip6len); 748 /* -1 == no app on SEND socket */ 749 if (error == 0) 750 return (IPPROTO_DONE); 751 nd6_rs_input(m, off, icmp6len); 752 } else 753 nd6_rs_input(m, off, icmp6len); 754 m = NULL; 755 goto freeit; 756 } 757 if (send_sendso_input_hook != NULL) { 758 IP6_EXTHDR_CHECK(n, off, 759 icmp6len, IPPROTO_DONE); 760 error = send_sendso_input_hook(n, ifp, 761 SND_IN, ip6len); 762 if (error == 0) 763 goto freeit; 764 /* -1 == no app on SEND socket */ 765 nd6_rs_input(n, off, icmp6len); 766 } else 767 nd6_rs_input(n, off, icmp6len); 768 /* m stays. */ 769 break; 770 771 case ND_ROUTER_ADVERT: 772 icmp6_ifstat_inc(ifp, ifs6_in_routeradvert); 773 if (code != 0) 774 goto badcode; 775 if (icmp6len < sizeof(struct nd_router_advert)) 776 goto badlen; 777 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) { 778 779 /* Send incoming SeND-protected/ND packet to user space. */ 780 if (send_sendso_input_hook != NULL) { 781 error = send_sendso_input_hook(m, ifp, 782 SND_IN, ip6len); 783 if (error == 0) 784 return (IPPROTO_DONE); 785 nd6_ra_input(m, off, icmp6len); 786 } else 787 nd6_ra_input(m, off, icmp6len); 788 m = NULL; 789 goto freeit; 790 } 791 if (send_sendso_input_hook != NULL) { 792 error = send_sendso_input_hook(n, ifp, 793 SND_IN, ip6len); 794 if (error == 0) 795 goto freeit; 796 nd6_ra_input(n, off, icmp6len); 797 } else 798 nd6_ra_input(n, off, icmp6len); 799 /* m stays. */ 800 break; 801 802 case ND_NEIGHBOR_SOLICIT: 803 icmp6_ifstat_inc(ifp, ifs6_in_neighborsolicit); 804 if (code != 0) 805 goto badcode; 806 if (icmp6len < sizeof(struct nd_neighbor_solicit)) 807 goto badlen; 808 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) { 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_ns_input(m, off, icmp6len); 815 } else 816 nd6_ns_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_ns_input(n, off, icmp6len); 826 } else 827 nd6_ns_input(n, off, icmp6len); 828 /* m stays. */ 829 break; 830 831 case ND_NEIGHBOR_ADVERT: 832 icmp6_ifstat_inc(ifp, ifs6_in_neighboradvert); 833 if (code != 0) 834 goto badcode; 835 if (icmp6len < sizeof(struct nd_neighbor_advert)) 836 goto badlen; 837 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) { 838 839 /* Send incoming SeND-protected/ND packet to user space. */ 840 if (send_sendso_input_hook != NULL) { 841 error = send_sendso_input_hook(m, ifp, 842 SND_IN, ip6len); 843 if (error == 0) 844 return (IPPROTO_DONE); 845 nd6_na_input(m, off, icmp6len); 846 } else 847 nd6_na_input(m, off, icmp6len); 848 m = NULL; 849 goto freeit; 850 } 851 if (send_sendso_input_hook != NULL) { 852 error = send_sendso_input_hook(n, ifp, 853 SND_IN, ip6len); 854 if (error == 0) 855 goto freeit; 856 nd6_na_input(n, off, icmp6len); 857 } else 858 nd6_na_input(n, off, icmp6len); 859 /* m stays. */ 860 break; 861 862 case ND_REDIRECT: 863 icmp6_ifstat_inc(ifp, ifs6_in_redirect); 864 if (code != 0) 865 goto badcode; 866 if (icmp6len < sizeof(struct nd_redirect)) 867 goto badlen; 868 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) { 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 icmp6_redirect_input(m, off); 875 } else 876 icmp6_redirect_input(m, off); 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 icmp6_redirect_input(n, off); 886 } else 887 icmp6_redirect_input(n, off); 888 /* m stays. */ 889 break; 890 891 case ICMP6_ROUTER_RENUMBERING: 892 if (code != ICMP6_ROUTER_RENUMBERING_COMMAND && 893 code != ICMP6_ROUTER_RENUMBERING_RESULT) 894 goto badcode; 895 if (icmp6len < sizeof(struct icmp6_router_renum)) 896 goto badlen; 897 break; 898 899 default: 900 nd6log((LOG_DEBUG, 901 "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n", 902 icmp6->icmp6_type, ip6_sprintf(ip6bufs, &ip6->ip6_src), 903 ip6_sprintf(ip6bufd, &ip6->ip6_dst), 904 ifp ? ifp->if_index : 0)); 905 if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) { 906 /* ICMPv6 error: MUST deliver it by spec... */ 907 code = PRC_NCMDS; 908 /* deliver */ 909 } else { 910 /* ICMPv6 informational: MUST not deliver */ 911 break; 912 } 913 deliver: 914 if (icmp6_notify_error(&m, off, icmp6len, code) != 0) { 915 /* In this case, m should've been freed. */ 916 return (IPPROTO_DONE); 917 } 918 break; 919 920 badcode: 921 ICMP6STAT_INC(icp6s_badcode); 922 break; 923 924 badlen: 925 ICMP6STAT_INC(icp6s_badlen); 926 break; 927 } 928 929 /* deliver the packet to appropriate sockets */ 930 icmp6_rip6_input(&m, *offp); 931 932 return IPPROTO_DONE; 933 934 freeit: 935 m_freem(m); 936 return IPPROTO_DONE; 937 } 938 939 static int 940 icmp6_notify_error(struct mbuf **mp, int off, int icmp6len, int code) 941 { 942 struct mbuf *m = *mp; 943 struct icmp6_hdr *icmp6; 944 struct ip6_hdr *eip6; 945 u_int32_t notifymtu; 946 struct sockaddr_in6 icmp6src, icmp6dst; 947 948 if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) { 949 ICMP6STAT_INC(icp6s_tooshort); 950 goto freeit; 951 } 952 #ifndef PULLDOWN_TEST 953 IP6_EXTHDR_CHECK(m, off, 954 sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr), -1); 955 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 956 #else 957 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, 958 sizeof(*icmp6) + sizeof(struct ip6_hdr)); 959 if (icmp6 == NULL) { 960 ICMP6STAT_INC(icp6s_tooshort); 961 return (-1); 962 } 963 #endif 964 eip6 = (struct ip6_hdr *)(icmp6 + 1); 965 966 /* Detect the upper level protocol */ 967 { 968 void (*ctlfunc)(int, struct sockaddr *, void *); 969 u_int8_t nxt = eip6->ip6_nxt; 970 int eoff = off + sizeof(struct icmp6_hdr) + 971 sizeof(struct ip6_hdr); 972 struct ip6ctlparam ip6cp; 973 struct in6_addr *finaldst = NULL; 974 int icmp6type = icmp6->icmp6_type; 975 struct ip6_frag *fh; 976 struct ip6_rthdr *rth; 977 struct ip6_rthdr0 *rth0; 978 int rthlen; 979 980 while (1) { /* XXX: should avoid infinite loop explicitly? */ 981 struct ip6_ext *eh; 982 983 switch (nxt) { 984 case IPPROTO_HOPOPTS: 985 case IPPROTO_DSTOPTS: 986 case IPPROTO_AH: 987 #ifndef PULLDOWN_TEST 988 IP6_EXTHDR_CHECK(m, 0, 989 eoff + sizeof(struct ip6_ext), -1); 990 eh = (struct ip6_ext *)(mtod(m, caddr_t) + eoff); 991 #else 992 IP6_EXTHDR_GET(eh, struct ip6_ext *, m, 993 eoff, sizeof(*eh)); 994 if (eh == NULL) { 995 ICMP6STAT_INC(icp6s_tooshort); 996 return (-1); 997 } 998 #endif 999 1000 if (nxt == IPPROTO_AH) 1001 eoff += (eh->ip6e_len + 2) << 2; 1002 else 1003 eoff += (eh->ip6e_len + 1) << 3; 1004 nxt = eh->ip6e_nxt; 1005 break; 1006 case IPPROTO_ROUTING: 1007 /* 1008 * When the erroneous packet contains a 1009 * routing header, we should examine the 1010 * header to determine the final destination. 1011 * Otherwise, we can't properly update 1012 * information that depends on the final 1013 * destination (e.g. path MTU). 1014 */ 1015 #ifndef PULLDOWN_TEST 1016 IP6_EXTHDR_CHECK(m, 0, eoff + sizeof(*rth), -1); 1017 rth = (struct ip6_rthdr *) 1018 (mtod(m, caddr_t) + eoff); 1019 #else 1020 IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m, 1021 eoff, sizeof(*rth)); 1022 if (rth == NULL) { 1023 ICMP6STAT_INC(icp6s_tooshort); 1024 return (-1); 1025 } 1026 #endif 1027 rthlen = (rth->ip6r_len + 1) << 3; 1028 /* 1029 * XXX: currently there is no 1030 * officially defined type other 1031 * than type-0. 1032 * Note that if the segment left field 1033 * is 0, all intermediate hops must 1034 * have been passed. 1035 */ 1036 if (rth->ip6r_segleft && 1037 rth->ip6r_type == IPV6_RTHDR_TYPE_0) { 1038 int hops; 1039 1040 #ifndef PULLDOWN_TEST 1041 IP6_EXTHDR_CHECK(m, 0, eoff + rthlen, -1); 1042 rth0 = (struct ip6_rthdr0 *) 1043 (mtod(m, caddr_t) + eoff); 1044 #else 1045 IP6_EXTHDR_GET(rth0, 1046 struct ip6_rthdr0 *, m, 1047 eoff, rthlen); 1048 if (rth0 == NULL) { 1049 ICMP6STAT_INC(icp6s_tooshort); 1050 return (-1); 1051 } 1052 #endif 1053 /* just ignore a bogus header */ 1054 if ((rth0->ip6r0_len % 2) == 0 && 1055 (hops = rth0->ip6r0_len/2)) 1056 finaldst = (struct in6_addr *)(rth0 + 1) + (hops - 1); 1057 } 1058 eoff += rthlen; 1059 nxt = rth->ip6r_nxt; 1060 break; 1061 case IPPROTO_FRAGMENT: 1062 #ifndef PULLDOWN_TEST 1063 IP6_EXTHDR_CHECK(m, 0, eoff + 1064 sizeof(struct ip6_frag), -1); 1065 fh = (struct ip6_frag *)(mtod(m, caddr_t) + 1066 eoff); 1067 #else 1068 IP6_EXTHDR_GET(fh, struct ip6_frag *, m, 1069 eoff, sizeof(*fh)); 1070 if (fh == NULL) { 1071 ICMP6STAT_INC(icp6s_tooshort); 1072 return (-1); 1073 } 1074 #endif 1075 /* 1076 * Data after a fragment header is meaningless 1077 * unless it is the first fragment, but 1078 * we'll go to the notify label for path MTU 1079 * discovery. 1080 */ 1081 if (fh->ip6f_offlg & IP6F_OFF_MASK) 1082 goto notify; 1083 1084 eoff += sizeof(struct ip6_frag); 1085 nxt = fh->ip6f_nxt; 1086 break; 1087 default: 1088 /* 1089 * This case includes ESP and the No Next 1090 * Header. In such cases going to the notify 1091 * label does not have any meaning 1092 * (i.e. ctlfunc will be NULL), but we go 1093 * anyway since we might have to update 1094 * path MTU information. 1095 */ 1096 goto notify; 1097 } 1098 } 1099 notify: 1100 #ifndef PULLDOWN_TEST 1101 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 1102 #else 1103 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, 1104 sizeof(*icmp6) + sizeof(struct ip6_hdr)); 1105 if (icmp6 == NULL) { 1106 ICMP6STAT_INC(icp6s_tooshort); 1107 return (-1); 1108 } 1109 #endif 1110 1111 /* 1112 * retrieve parameters from the inner IPv6 header, and convert 1113 * them into sockaddr structures. 1114 * XXX: there is no guarantee that the source or destination 1115 * addresses of the inner packet are in the same scope as 1116 * the addresses of the icmp packet. But there is no other 1117 * way to determine the zone. 1118 */ 1119 eip6 = (struct ip6_hdr *)(icmp6 + 1); 1120 1121 bzero(&icmp6dst, sizeof(icmp6dst)); 1122 icmp6dst.sin6_len = sizeof(struct sockaddr_in6); 1123 icmp6dst.sin6_family = AF_INET6; 1124 if (finaldst == NULL) 1125 icmp6dst.sin6_addr = eip6->ip6_dst; 1126 else 1127 icmp6dst.sin6_addr = *finaldst; 1128 if (in6_setscope(&icmp6dst.sin6_addr, m->m_pkthdr.rcvif, NULL)) 1129 goto freeit; 1130 bzero(&icmp6src, sizeof(icmp6src)); 1131 icmp6src.sin6_len = sizeof(struct sockaddr_in6); 1132 icmp6src.sin6_family = AF_INET6; 1133 icmp6src.sin6_addr = eip6->ip6_src; 1134 if (in6_setscope(&icmp6src.sin6_addr, m->m_pkthdr.rcvif, NULL)) 1135 goto freeit; 1136 icmp6src.sin6_flowinfo = 1137 (eip6->ip6_flow & IPV6_FLOWLABEL_MASK); 1138 1139 if (finaldst == NULL) 1140 finaldst = &eip6->ip6_dst; 1141 ip6cp.ip6c_m = m; 1142 ip6cp.ip6c_icmp6 = icmp6; 1143 ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1); 1144 ip6cp.ip6c_off = eoff; 1145 ip6cp.ip6c_finaldst = finaldst; 1146 ip6cp.ip6c_src = &icmp6src; 1147 ip6cp.ip6c_nxt = nxt; 1148 1149 if (icmp6type == ICMP6_PACKET_TOO_BIG) { 1150 notifymtu = ntohl(icmp6->icmp6_mtu); 1151 ip6cp.ip6c_cmdarg = (void *)¬ifymtu; 1152 icmp6_mtudisc_update(&ip6cp, 1); /*XXX*/ 1153 } 1154 1155 ctlfunc = (void (*)(int, struct sockaddr *, void *)) 1156 (inet6sw[ip6_protox[nxt]].pr_ctlinput); 1157 if (ctlfunc) { 1158 (void) (*ctlfunc)(code, (struct sockaddr *)&icmp6dst, 1159 &ip6cp); 1160 } 1161 } 1162 *mp = m; 1163 return (0); 1164 1165 freeit: 1166 m_freem(m); 1167 return (-1); 1168 } 1169 1170 void 1171 icmp6_mtudisc_update(struct ip6ctlparam *ip6cp, int validated) 1172 { 1173 struct in6_addr *dst = ip6cp->ip6c_finaldst; 1174 struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6; 1175 struct mbuf *m = ip6cp->ip6c_m; /* will be necessary for scope issue */ 1176 u_int mtu = ntohl(icmp6->icmp6_mtu); 1177 struct in_conninfo inc; 1178 1179 #if 0 1180 /* 1181 * RFC2460 section 5, last paragraph. 1182 * even though minimum link MTU for IPv6 is IPV6_MMTU, 1183 * we may see ICMPv6 too big with mtu < IPV6_MMTU 1184 * due to packet translator in the middle. 1185 * see ip6_output() and ip6_getpmtu() "alwaysfrag" case for 1186 * special handling. 1187 */ 1188 if (mtu < IPV6_MMTU) 1189 return; 1190 #endif 1191 1192 /* 1193 * we reject ICMPv6 too big with abnormally small value. 1194 * XXX what is the good definition of "abnormally small"? 1195 */ 1196 if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8) 1197 return; 1198 1199 if (!validated) 1200 return; 1201 1202 /* 1203 * In case the suggested mtu is less than IPV6_MMTU, we 1204 * only need to remember that it was for above mentioned 1205 * "alwaysfrag" case. 1206 * Try to be as close to the spec as possible. 1207 */ 1208 if (mtu < IPV6_MMTU) 1209 mtu = IPV6_MMTU - 8; 1210 1211 bzero(&inc, sizeof(inc)); 1212 inc.inc_fibnum = M_GETFIB(m); 1213 inc.inc_flags |= INC_ISIPV6; 1214 inc.inc6_faddr = *dst; 1215 if (in6_setscope(&inc.inc6_faddr, m->m_pkthdr.rcvif, NULL)) 1216 return; 1217 1218 if (mtu < tcp_maxmtu6(&inc, NULL)) { 1219 tcp_hc_updatemtu(&inc, mtu); 1220 ICMP6STAT_INC(icp6s_pmtuchg); 1221 } 1222 } 1223 1224 /* 1225 * Process a Node Information Query packet, based on 1226 * draft-ietf-ipngwg-icmp-name-lookups-07. 1227 * 1228 * Spec incompatibilities: 1229 * - IPv6 Subject address handling 1230 * - IPv4 Subject address handling support missing 1231 * - Proxy reply (answer even if it's not for me) 1232 * - joins NI group address at in6_ifattach() time only, does not cope 1233 * with hostname changes by sethostname(3) 1234 */ 1235 static struct mbuf * 1236 ni6_input(struct mbuf *m, int off) 1237 { 1238 struct icmp6_nodeinfo *ni6, *nni6; 1239 struct mbuf *n = NULL; 1240 struct prison *pr; 1241 u_int16_t qtype; 1242 int subjlen; 1243 int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); 1244 struct ni_reply_fqdn *fqdn; 1245 int addrs; /* for NI_QTYPE_NODEADDR */ 1246 struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */ 1247 struct in6_addr in6_subj; /* subject address */ 1248 struct ip6_hdr *ip6; 1249 int oldfqdn = 0; /* if 1, return pascal string (03 draft) */ 1250 char *subj = NULL; 1251 struct in6_ifaddr *ia6 = NULL; 1252 1253 ip6 = mtod(m, struct ip6_hdr *); 1254 #ifndef PULLDOWN_TEST 1255 ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off); 1256 #else 1257 IP6_EXTHDR_GET(ni6, struct icmp6_nodeinfo *, m, off, sizeof(*ni6)); 1258 if (ni6 == NULL) { 1259 /* m is already reclaimed */ 1260 return (NULL); 1261 } 1262 #endif 1263 1264 /* 1265 * Validate IPv6 source address. 1266 * The default configuration MUST be to refuse answering queries from 1267 * global-scope addresses according to RFC4602. 1268 * Notes: 1269 * - it's not very clear what "refuse" means; this implementation 1270 * simply drops it. 1271 * - it's not very easy to identify global-scope (unicast) addresses 1272 * since there are many prefixes for them. It should be safer 1273 * and in practice sufficient to check "all" but loopback and 1274 * link-local (note that site-local unicast was deprecated and 1275 * ULA is defined as global scope-wise) 1276 */ 1277 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_GLOBALOK) == 0 && 1278 !IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) && 1279 !IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) 1280 goto bad; 1281 1282 /* 1283 * Validate IPv6 destination address. 1284 * 1285 * The Responder must discard the Query without further processing 1286 * unless it is one of the Responder's unicast or anycast addresses, or 1287 * a link-local scope multicast address which the Responder has joined. 1288 * [RFC4602, Section 5.] 1289 */ 1290 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 1291 if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst)) 1292 goto bad; 1293 /* else it's a link-local multicast, fine */ 1294 } else { /* unicast or anycast */ 1295 ia6 = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */); 1296 if (ia6 == NULL) 1297 goto bad; /* XXX impossible */ 1298 1299 if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) && 1300 !(V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK)) { 1301 ifa_free(&ia6->ia_ifa); 1302 nd6log((LOG_DEBUG, "ni6_input: ignore node info to " 1303 "a temporary address in %s:%d", 1304 __FILE__, __LINE__)); 1305 goto bad; 1306 } 1307 ifa_free(&ia6->ia_ifa); 1308 } 1309 1310 /* validate query Subject field. */ 1311 qtype = ntohs(ni6->ni_qtype); 1312 subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo); 1313 switch (qtype) { 1314 case NI_QTYPE_NOOP: 1315 case NI_QTYPE_SUPTYPES: 1316 /* 07 draft */ 1317 if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0) 1318 break; 1319 /* FALLTHROUGH */ 1320 case NI_QTYPE_FQDN: 1321 case NI_QTYPE_NODEADDR: 1322 case NI_QTYPE_IPV4ADDR: 1323 switch (ni6->ni_code) { 1324 case ICMP6_NI_SUBJ_IPV6: 1325 #if ICMP6_NI_SUBJ_IPV6 != 0 1326 case 0: 1327 #endif 1328 /* 1329 * backward compatibility - try to accept 03 draft 1330 * format, where no Subject is present. 1331 */ 1332 if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 && 1333 subjlen == 0) { 1334 oldfqdn++; 1335 break; 1336 } 1337 #if ICMP6_NI_SUBJ_IPV6 != 0 1338 if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6) 1339 goto bad; 1340 #endif 1341 1342 if (subjlen != sizeof(struct in6_addr)) 1343 goto bad; 1344 1345 /* 1346 * Validate Subject address. 1347 * 1348 * Not sure what exactly "address belongs to the node" 1349 * means in the spec, is it just unicast, or what? 1350 * 1351 * At this moment we consider Subject address as 1352 * "belong to the node" if the Subject address equals 1353 * to the IPv6 destination address; validation for 1354 * IPv6 destination address should have done enough 1355 * check for us. 1356 * 1357 * We do not do proxy at this moment. 1358 */ 1359 /* m_pulldown instead of copy? */ 1360 m_copydata(m, off + sizeof(struct icmp6_nodeinfo), 1361 subjlen, (caddr_t)&in6_subj); 1362 if (in6_setscope(&in6_subj, m->m_pkthdr.rcvif, NULL)) 1363 goto bad; 1364 1365 subj = (char *)&in6_subj; 1366 if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &in6_subj)) 1367 break; 1368 1369 /* 1370 * XXX if we are to allow other cases, we should really 1371 * be careful about scope here. 1372 * basically, we should disallow queries toward IPv6 1373 * destination X with subject Y, 1374 * if scope(X) > scope(Y). 1375 * if we allow scope(X) > scope(Y), it will result in 1376 * information leakage across scope boundary. 1377 */ 1378 goto bad; 1379 1380 case ICMP6_NI_SUBJ_FQDN: 1381 /* 1382 * Validate Subject name with gethostname(3). 1383 * 1384 * The behavior may need some debate, since: 1385 * - we are not sure if the node has FQDN as 1386 * hostname (returned by gethostname(3)). 1387 * - the code does wildcard match for truncated names. 1388 * however, we are not sure if we want to perform 1389 * wildcard match, if gethostname(3) side has 1390 * truncated hostname. 1391 */ 1392 pr = curthread->td_ucred->cr_prison; 1393 mtx_lock(&pr->pr_mtx); 1394 n = ni6_nametodns(pr->pr_hostname, 1395 strlen(pr->pr_hostname), 0); 1396 mtx_unlock(&pr->pr_mtx); 1397 if (!n || n->m_next || n->m_len == 0) 1398 goto bad; 1399 IP6_EXTHDR_GET(subj, char *, m, 1400 off + sizeof(struct icmp6_nodeinfo), subjlen); 1401 if (subj == NULL) 1402 goto bad; 1403 if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *), 1404 n->m_len)) { 1405 goto bad; 1406 } 1407 m_freem(n); 1408 n = NULL; 1409 break; 1410 1411 case ICMP6_NI_SUBJ_IPV4: /* XXX: to be implemented? */ 1412 default: 1413 goto bad; 1414 } 1415 break; 1416 } 1417 1418 /* refuse based on configuration. XXX ICMP6_NI_REFUSED? */ 1419 switch (qtype) { 1420 case NI_QTYPE_FQDN: 1421 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_FQDNOK) == 0) 1422 goto bad; 1423 break; 1424 case NI_QTYPE_NODEADDR: 1425 case NI_QTYPE_IPV4ADDR: 1426 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_NODEADDROK) == 0) 1427 goto bad; 1428 break; 1429 } 1430 1431 /* guess reply length */ 1432 switch (qtype) { 1433 case NI_QTYPE_NOOP: 1434 break; /* no reply data */ 1435 case NI_QTYPE_SUPTYPES: 1436 replylen += sizeof(u_int32_t); 1437 break; 1438 case NI_QTYPE_FQDN: 1439 /* XXX will append an mbuf */ 1440 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); 1441 break; 1442 case NI_QTYPE_NODEADDR: 1443 addrs = ni6_addrs(ni6, m, &ifp, (struct in6_addr *)subj); 1444 if ((replylen += addrs * (sizeof(struct in6_addr) + 1445 sizeof(u_int32_t))) > MCLBYTES) 1446 replylen = MCLBYTES; /* XXX: will truncate pkt later */ 1447 break; 1448 case NI_QTYPE_IPV4ADDR: 1449 /* unsupported - should respond with unknown Qtype? */ 1450 break; 1451 default: 1452 /* 1453 * XXX: We must return a reply with the ICMP6 code 1454 * `unknown Qtype' in this case. However we regard the case 1455 * as an FQDN query for backward compatibility. 1456 * Older versions set a random value to this field, 1457 * so it rarely varies in the defined qtypes. 1458 * But the mechanism is not reliable... 1459 * maybe we should obsolete older versions. 1460 */ 1461 qtype = NI_QTYPE_FQDN; 1462 /* XXX will append an mbuf */ 1463 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); 1464 oldfqdn++; 1465 break; 1466 } 1467 1468 /* Allocate an mbuf to reply. */ 1469 if (replylen > MCLBYTES) { 1470 /* 1471 * XXX: should we try to allocate more? But MCLBYTES 1472 * is probably much larger than IPV6_MMTU... 1473 */ 1474 goto bad; 1475 } 1476 if (replylen > MHLEN) 1477 n = m_getcl(M_NOWAIT, m->m_type, M_PKTHDR); 1478 else 1479 n = m_gethdr(M_NOWAIT, m->m_type); 1480 if (n == NULL) { 1481 m_freem(m); 1482 return (NULL); 1483 } 1484 m_move_pkthdr(n, m); /* just for recvif and FIB */ 1485 n->m_pkthdr.len = n->m_len = replylen; 1486 1487 /* copy mbuf header and IPv6 + Node Information base headers */ 1488 bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr)); 1489 nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1); 1490 bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo)); 1491 1492 /* qtype dependent procedure */ 1493 switch (qtype) { 1494 case NI_QTYPE_NOOP: 1495 nni6->ni_code = ICMP6_NI_SUCCESS; 1496 nni6->ni_flags = 0; 1497 break; 1498 case NI_QTYPE_SUPTYPES: 1499 { 1500 u_int32_t v; 1501 nni6->ni_code = ICMP6_NI_SUCCESS; 1502 nni6->ni_flags = htons(0x0000); /* raw bitmap */ 1503 /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */ 1504 v = (u_int32_t)htonl(0x0000000f); 1505 bcopy(&v, nni6 + 1, sizeof(u_int32_t)); 1506 break; 1507 } 1508 case NI_QTYPE_FQDN: 1509 nni6->ni_code = ICMP6_NI_SUCCESS; 1510 fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) + 1511 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo)); 1512 nni6->ni_flags = 0; /* XXX: meaningless TTL */ 1513 fqdn->ni_fqdn_ttl = 0; /* ditto. */ 1514 /* 1515 * XXX do we really have FQDN in hostname? 1516 */ 1517 pr = curthread->td_ucred->cr_prison; 1518 mtx_lock(&pr->pr_mtx); 1519 n->m_next = ni6_nametodns(pr->pr_hostname, 1520 strlen(pr->pr_hostname), oldfqdn); 1521 mtx_unlock(&pr->pr_mtx); 1522 if (n->m_next == NULL) 1523 goto bad; 1524 /* XXX we assume that n->m_next is not a chain */ 1525 if (n->m_next->m_next != NULL) 1526 goto bad; 1527 n->m_pkthdr.len += n->m_next->m_len; 1528 break; 1529 case NI_QTYPE_NODEADDR: 1530 { 1531 int lenlim, copied; 1532 1533 nni6->ni_code = ICMP6_NI_SUCCESS; 1534 n->m_pkthdr.len = n->m_len = 1535 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); 1536 lenlim = M_TRAILINGSPACE(n); 1537 copied = ni6_store_addrs(ni6, nni6, ifp, lenlim); 1538 /* XXX: reset mbuf length */ 1539 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + 1540 sizeof(struct icmp6_nodeinfo) + copied; 1541 break; 1542 } 1543 default: 1544 break; /* XXX impossible! */ 1545 } 1546 1547 nni6->ni_type = ICMP6_NI_REPLY; 1548 m_freem(m); 1549 return (n); 1550 1551 bad: 1552 m_freem(m); 1553 if (n) 1554 m_freem(n); 1555 return (NULL); 1556 } 1557 1558 /* 1559 * make a mbuf with DNS-encoded string. no compression support. 1560 * 1561 * XXX names with less than 2 dots (like "foo" or "foo.section") will be 1562 * treated as truncated name (two \0 at the end). this is a wild guess. 1563 * 1564 * old - return pascal string if non-zero 1565 */ 1566 static struct mbuf * 1567 ni6_nametodns(const char *name, int namelen, int old) 1568 { 1569 struct mbuf *m; 1570 char *cp, *ep; 1571 const char *p, *q; 1572 int i, len, nterm; 1573 1574 if (old) 1575 len = namelen + 1; 1576 else 1577 len = MCLBYTES; 1578 1579 /* Because MAXHOSTNAMELEN is usually 256, we use cluster mbuf. */ 1580 if (len > MLEN) 1581 m = m_getcl(M_NOWAIT, MT_DATA, 0); 1582 else 1583 m = m_get(M_NOWAIT, MT_DATA); 1584 if (m == NULL) 1585 goto fail; 1586 1587 if (old) { 1588 m->m_len = len; 1589 *mtod(m, char *) = namelen; 1590 bcopy(name, mtod(m, char *) + 1, namelen); 1591 return m; 1592 } else { 1593 m->m_len = 0; 1594 cp = mtod(m, char *); 1595 ep = mtod(m, char *) + M_TRAILINGSPACE(m); 1596 1597 /* if not certain about my name, return empty buffer */ 1598 if (namelen == 0) 1599 return m; 1600 1601 /* 1602 * guess if it looks like shortened hostname, or FQDN. 1603 * shortened hostname needs two trailing "\0". 1604 */ 1605 i = 0; 1606 for (p = name; p < name + namelen; p++) { 1607 if (*p && *p == '.') 1608 i++; 1609 } 1610 if (i < 2) 1611 nterm = 2; 1612 else 1613 nterm = 1; 1614 1615 p = name; 1616 while (cp < ep && p < name + namelen) { 1617 i = 0; 1618 for (q = p; q < name + namelen && *q && *q != '.'; q++) 1619 i++; 1620 /* result does not fit into mbuf */ 1621 if (cp + i + 1 >= ep) 1622 goto fail; 1623 /* 1624 * DNS label length restriction, RFC1035 page 8. 1625 * "i == 0" case is included here to avoid returning 1626 * 0-length label on "foo..bar". 1627 */ 1628 if (i <= 0 || i >= 64) 1629 goto fail; 1630 *cp++ = i; 1631 bcopy(p, cp, i); 1632 cp += i; 1633 p = q; 1634 if (p < name + namelen && *p == '.') 1635 p++; 1636 } 1637 /* termination */ 1638 if (cp + nterm >= ep) 1639 goto fail; 1640 while (nterm-- > 0) 1641 *cp++ = '\0'; 1642 m->m_len = cp - mtod(m, char *); 1643 return m; 1644 } 1645 1646 panic("should not reach here"); 1647 /* NOTREACHED */ 1648 1649 fail: 1650 if (m) 1651 m_freem(m); 1652 return NULL; 1653 } 1654 1655 /* 1656 * check if two DNS-encoded string matches. takes care of truncated 1657 * form (with \0\0 at the end). no compression support. 1658 * XXX upper/lowercase match (see RFC2065) 1659 */ 1660 static int 1661 ni6_dnsmatch(const char *a, int alen, const char *b, int blen) 1662 { 1663 const char *a0, *b0; 1664 int l; 1665 1666 /* simplest case - need validation? */ 1667 if (alen == blen && bcmp(a, b, alen) == 0) 1668 return 1; 1669 1670 a0 = a; 1671 b0 = b; 1672 1673 /* termination is mandatory */ 1674 if (alen < 2 || blen < 2) 1675 return 0; 1676 if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0') 1677 return 0; 1678 alen--; 1679 blen--; 1680 1681 while (a - a0 < alen && b - b0 < blen) { 1682 if (a - a0 + 1 > alen || b - b0 + 1 > blen) 1683 return 0; 1684 1685 if ((signed char)a[0] < 0 || (signed char)b[0] < 0) 1686 return 0; 1687 /* we don't support compression yet */ 1688 if (a[0] >= 64 || b[0] >= 64) 1689 return 0; 1690 1691 /* truncated case */ 1692 if (a[0] == 0 && a - a0 == alen - 1) 1693 return 1; 1694 if (b[0] == 0 && b - b0 == blen - 1) 1695 return 1; 1696 if (a[0] == 0 || b[0] == 0) 1697 return 0; 1698 1699 if (a[0] != b[0]) 1700 return 0; 1701 l = a[0]; 1702 if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen) 1703 return 0; 1704 if (bcmp(a + 1, b + 1, l) != 0) 1705 return 0; 1706 1707 a += 1 + l; 1708 b += 1 + l; 1709 } 1710 1711 if (a - a0 == alen && b - b0 == blen) 1712 return 1; 1713 else 1714 return 0; 1715 } 1716 1717 /* 1718 * calculate the number of addresses to be returned in the node info reply. 1719 */ 1720 static int 1721 ni6_addrs(struct icmp6_nodeinfo *ni6, struct mbuf *m, struct ifnet **ifpp, 1722 struct in6_addr *subj) 1723 { 1724 struct ifnet *ifp; 1725 struct in6_ifaddr *ifa6; 1726 struct ifaddr *ifa; 1727 int addrs = 0, addrsofif, iffound = 0; 1728 int niflags = ni6->ni_flags; 1729 1730 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) { 1731 switch (ni6->ni_code) { 1732 case ICMP6_NI_SUBJ_IPV6: 1733 if (subj == NULL) /* must be impossible... */ 1734 return (0); 1735 break; 1736 default: 1737 /* 1738 * XXX: we only support IPv6 subject address for 1739 * this Qtype. 1740 */ 1741 return (0); 1742 } 1743 } 1744 1745 IFNET_RLOCK_NOSLEEP(); 1746 TAILQ_FOREACH(ifp, &V_ifnet, if_link) { 1747 addrsofif = 0; 1748 IF_ADDR_RLOCK(ifp); 1749 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 1750 if (ifa->ifa_addr->sa_family != AF_INET6) 1751 continue; 1752 ifa6 = (struct in6_ifaddr *)ifa; 1753 1754 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 && 1755 IN6_ARE_ADDR_EQUAL(subj, &ifa6->ia_addr.sin6_addr)) 1756 iffound = 1; 1757 1758 /* 1759 * IPv4-mapped addresses can only be returned by a 1760 * Node Information proxy, since they represent 1761 * addresses of IPv4-only nodes, which perforce do 1762 * not implement this protocol. 1763 * [icmp-name-lookups-07, Section 5.4] 1764 * So we don't support NI_NODEADDR_FLAG_COMPAT in 1765 * this function at this moment. 1766 */ 1767 1768 /* What do we have to do about ::1? */ 1769 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { 1770 case IPV6_ADDR_SCOPE_LINKLOCAL: 1771 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) 1772 continue; 1773 break; 1774 case IPV6_ADDR_SCOPE_SITELOCAL: 1775 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) 1776 continue; 1777 break; 1778 case IPV6_ADDR_SCOPE_GLOBAL: 1779 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) 1780 continue; 1781 break; 1782 default: 1783 continue; 1784 } 1785 1786 /* 1787 * check if anycast is okay. 1788 * XXX: just experimental. not in the spec. 1789 */ 1790 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && 1791 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) 1792 continue; /* we need only unicast addresses */ 1793 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && 1794 (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) { 1795 continue; 1796 } 1797 addrsofif++; /* count the address */ 1798 } 1799 IF_ADDR_RUNLOCK(ifp); 1800 if (iffound) { 1801 *ifpp = ifp; 1802 IFNET_RUNLOCK_NOSLEEP(); 1803 return (addrsofif); 1804 } 1805 1806 addrs += addrsofif; 1807 } 1808 IFNET_RUNLOCK_NOSLEEP(); 1809 1810 return (addrs); 1811 } 1812 1813 static int 1814 ni6_store_addrs(struct icmp6_nodeinfo *ni6, struct icmp6_nodeinfo *nni6, 1815 struct ifnet *ifp0, int resid) 1816 { 1817 struct ifnet *ifp; 1818 struct in6_ifaddr *ifa6; 1819 struct ifaddr *ifa; 1820 struct ifnet *ifp_dep = NULL; 1821 int copied = 0, allow_deprecated = 0; 1822 u_char *cp = (u_char *)(nni6 + 1); 1823 int niflags = ni6->ni_flags; 1824 u_int32_t ltime; 1825 1826 if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL)) 1827 return (0); /* needless to copy */ 1828 1829 IFNET_RLOCK_NOSLEEP(); 1830 ifp = ifp0 ? ifp0 : TAILQ_FIRST(&V_ifnet); 1831 again: 1832 1833 for (; ifp; ifp = TAILQ_NEXT(ifp, if_link)) { 1834 IF_ADDR_RLOCK(ifp); 1835 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 1836 if (ifa->ifa_addr->sa_family != AF_INET6) 1837 continue; 1838 ifa6 = (struct in6_ifaddr *)ifa; 1839 1840 if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 && 1841 allow_deprecated == 0) { 1842 /* 1843 * prefererred address should be put before 1844 * deprecated addresses. 1845 */ 1846 1847 /* record the interface for later search */ 1848 if (ifp_dep == NULL) 1849 ifp_dep = ifp; 1850 1851 continue; 1852 } else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 && 1853 allow_deprecated != 0) 1854 continue; /* we now collect deprecated addrs */ 1855 1856 /* What do we have to do about ::1? */ 1857 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { 1858 case IPV6_ADDR_SCOPE_LINKLOCAL: 1859 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) 1860 continue; 1861 break; 1862 case IPV6_ADDR_SCOPE_SITELOCAL: 1863 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) 1864 continue; 1865 break; 1866 case IPV6_ADDR_SCOPE_GLOBAL: 1867 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) 1868 continue; 1869 break; 1870 default: 1871 continue; 1872 } 1873 1874 /* 1875 * check if anycast is okay. 1876 * XXX: just experimental. not in the spec. 1877 */ 1878 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && 1879 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) 1880 continue; 1881 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && 1882 (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) { 1883 continue; 1884 } 1885 1886 /* now we can copy the address */ 1887 if (resid < sizeof(struct in6_addr) + 1888 sizeof(u_int32_t)) { 1889 IF_ADDR_RUNLOCK(ifp); 1890 /* 1891 * We give up much more copy. 1892 * Set the truncate flag and return. 1893 */ 1894 nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE; 1895 IFNET_RUNLOCK_NOSLEEP(); 1896 return (copied); 1897 } 1898 1899 /* 1900 * Set the TTL of the address. 1901 * The TTL value should be one of the following 1902 * according to the specification: 1903 * 1904 * 1. The remaining lifetime of a DHCP lease on the 1905 * address, or 1906 * 2. The remaining Valid Lifetime of a prefix from 1907 * which the address was derived through Stateless 1908 * Autoconfiguration. 1909 * 1910 * Note that we currently do not support stateful 1911 * address configuration by DHCPv6, so the former 1912 * case can't happen. 1913 */ 1914 if (ifa6->ia6_lifetime.ia6t_expire == 0) 1915 ltime = ND6_INFINITE_LIFETIME; 1916 else { 1917 if (ifa6->ia6_lifetime.ia6t_expire > 1918 time_uptime) 1919 ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_uptime); 1920 else 1921 ltime = 0; 1922 } 1923 1924 bcopy(<ime, cp, sizeof(u_int32_t)); 1925 cp += sizeof(u_int32_t); 1926 1927 /* copy the address itself */ 1928 bcopy(&ifa6->ia_addr.sin6_addr, cp, 1929 sizeof(struct in6_addr)); 1930 in6_clearscope((struct in6_addr *)cp); /* XXX */ 1931 cp += sizeof(struct in6_addr); 1932 1933 resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t)); 1934 copied += (sizeof(struct in6_addr) + sizeof(u_int32_t)); 1935 } 1936 IF_ADDR_RUNLOCK(ifp); 1937 if (ifp0) /* we need search only on the specified IF */ 1938 break; 1939 } 1940 1941 if (allow_deprecated == 0 && ifp_dep != NULL) { 1942 ifp = ifp_dep; 1943 allow_deprecated = 1; 1944 1945 goto again; 1946 } 1947 1948 IFNET_RUNLOCK_NOSLEEP(); 1949 1950 return (copied); 1951 } 1952 1953 /* 1954 * XXX almost dup'ed code with rip6_input. 1955 */ 1956 static int 1957 icmp6_rip6_input(struct mbuf **mp, int off) 1958 { 1959 struct mbuf *m = *mp; 1960 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1961 struct inpcb *in6p; 1962 struct inpcb *last = NULL; 1963 struct sockaddr_in6 fromsa; 1964 struct icmp6_hdr *icmp6; 1965 struct mbuf *opts = NULL; 1966 1967 #ifndef PULLDOWN_TEST 1968 /* this is assumed to be safe. */ 1969 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off); 1970 #else 1971 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6)); 1972 if (icmp6 == NULL) { 1973 /* m is already reclaimed */ 1974 return (IPPROTO_DONE); 1975 } 1976 #endif 1977 1978 /* 1979 * XXX: the address may have embedded scope zone ID, which should be 1980 * hidden from applications. 1981 */ 1982 bzero(&fromsa, sizeof(fromsa)); 1983 fromsa.sin6_family = AF_INET6; 1984 fromsa.sin6_len = sizeof(struct sockaddr_in6); 1985 fromsa.sin6_addr = ip6->ip6_src; 1986 if (sa6_recoverscope(&fromsa)) { 1987 m_freem(m); 1988 return (IPPROTO_DONE); 1989 } 1990 1991 INP_INFO_RLOCK(&V_ripcbinfo); 1992 LIST_FOREACH(in6p, &V_ripcb, inp_list) { 1993 if ((in6p->inp_vflag & INP_IPV6) == 0) 1994 continue; 1995 if (in6p->inp_ip_p != IPPROTO_ICMPV6) 1996 continue; 1997 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) && 1998 !IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &ip6->ip6_dst)) 1999 continue; 2000 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr) && 2001 !IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src)) 2002 continue; 2003 INP_RLOCK(in6p); 2004 if (ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type, 2005 in6p->in6p_icmp6filt)) { 2006 INP_RUNLOCK(in6p); 2007 continue; 2008 } 2009 if (last != NULL) { 2010 struct mbuf *n = NULL; 2011 2012 /* 2013 * Recent network drivers tend to allocate a single 2014 * mbuf cluster, rather than to make a couple of 2015 * mbufs without clusters. Also, since the IPv6 code 2016 * path tries to avoid m_pullup(), it is highly 2017 * probable that we still have an mbuf cluster here 2018 * even though the necessary length can be stored in an 2019 * mbuf's internal buffer. 2020 * Meanwhile, the default size of the receive socket 2021 * buffer for raw sockets is not so large. This means 2022 * the possibility of packet loss is relatively higher 2023 * than before. To avoid this scenario, we copy the 2024 * received data to a separate mbuf that does not use 2025 * a cluster, if possible. 2026 * XXX: it is better to copy the data after stripping 2027 * intermediate headers. 2028 */ 2029 if ((m->m_flags & M_EXT) && m->m_next == NULL && 2030 m->m_len <= MHLEN) { 2031 n = m_get(M_NOWAIT, m->m_type); 2032 if (n != NULL) { 2033 if (m_dup_pkthdr(n, m, M_NOWAIT)) { 2034 bcopy(m->m_data, n->m_data, 2035 m->m_len); 2036 n->m_len = m->m_len; 2037 } else { 2038 m_free(n); 2039 n = NULL; 2040 } 2041 } 2042 } 2043 if (n != NULL || 2044 (n = m_copy(m, 0, (int)M_COPYALL)) != NULL) { 2045 if (last->inp_flags & INP_CONTROLOPTS) 2046 ip6_savecontrol(last, n, &opts); 2047 /* strip intermediate headers */ 2048 m_adj(n, off); 2049 SOCKBUF_LOCK(&last->inp_socket->so_rcv); 2050 if (sbappendaddr_locked( 2051 &last->inp_socket->so_rcv, 2052 (struct sockaddr *)&fromsa, n, opts) 2053 == 0) { 2054 /* should notify about lost packet */ 2055 m_freem(n); 2056 if (opts) { 2057 m_freem(opts); 2058 } 2059 SOCKBUF_UNLOCK( 2060 &last->inp_socket->so_rcv); 2061 } else 2062 sorwakeup_locked(last->inp_socket); 2063 opts = NULL; 2064 } 2065 INP_RUNLOCK(last); 2066 } 2067 last = in6p; 2068 } 2069 INP_INFO_RUNLOCK(&V_ripcbinfo); 2070 if (last != NULL) { 2071 if (last->inp_flags & INP_CONTROLOPTS) 2072 ip6_savecontrol(last, m, &opts); 2073 /* strip intermediate headers */ 2074 m_adj(m, off); 2075 2076 /* avoid using mbuf clusters if possible (see above) */ 2077 if ((m->m_flags & M_EXT) && m->m_next == NULL && 2078 m->m_len <= MHLEN) { 2079 struct mbuf *n; 2080 2081 n = m_get(M_NOWAIT, m->m_type); 2082 if (n != NULL) { 2083 if (m_dup_pkthdr(n, m, M_NOWAIT)) { 2084 bcopy(m->m_data, n->m_data, m->m_len); 2085 n->m_len = m->m_len; 2086 2087 m_freem(m); 2088 m = n; 2089 } else { 2090 m_freem(n); 2091 n = NULL; 2092 } 2093 } 2094 } 2095 SOCKBUF_LOCK(&last->inp_socket->so_rcv); 2096 if (sbappendaddr_locked(&last->inp_socket->so_rcv, 2097 (struct sockaddr *)&fromsa, m, opts) == 0) { 2098 m_freem(m); 2099 if (opts) 2100 m_freem(opts); 2101 SOCKBUF_UNLOCK(&last->inp_socket->so_rcv); 2102 } else 2103 sorwakeup_locked(last->inp_socket); 2104 INP_RUNLOCK(last); 2105 } else { 2106 m_freem(m); 2107 IP6STAT_DEC(ip6s_delivered); 2108 } 2109 return IPPROTO_DONE; 2110 } 2111 2112 /* 2113 * Reflect the ip6 packet back to the source. 2114 * OFF points to the icmp6 header, counted from the top of the mbuf. 2115 */ 2116 void 2117 icmp6_reflect(struct mbuf *m, size_t off) 2118 { 2119 struct in6_addr src6, *srcp; 2120 struct ip6_hdr *ip6; 2121 struct icmp6_hdr *icmp6; 2122 struct in6_ifaddr *ia = NULL; 2123 struct ifnet *outif = NULL; 2124 int plen; 2125 int type, code, hlim; 2126 2127 /* too short to reflect */ 2128 if (off < sizeof(struct ip6_hdr)) { 2129 nd6log((LOG_DEBUG, 2130 "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n", 2131 (u_long)off, (u_long)sizeof(struct ip6_hdr), 2132 __FILE__, __LINE__)); 2133 goto bad; 2134 } 2135 2136 /* 2137 * If there are extra headers between IPv6 and ICMPv6, strip 2138 * off that header first. 2139 */ 2140 #ifdef DIAGNOSTIC 2141 if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN) 2142 panic("assumption failed in icmp6_reflect"); 2143 #endif 2144 if (off > sizeof(struct ip6_hdr)) { 2145 size_t l; 2146 struct ip6_hdr nip6; 2147 2148 l = off - sizeof(struct ip6_hdr); 2149 m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6); 2150 m_adj(m, l); 2151 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 2152 if (m->m_len < l) { 2153 if ((m = m_pullup(m, l)) == NULL) 2154 return; 2155 } 2156 bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6)); 2157 } else /* off == sizeof(struct ip6_hdr) */ { 2158 size_t l; 2159 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 2160 if (m->m_len < l) { 2161 if ((m = m_pullup(m, l)) == NULL) 2162 return; 2163 } 2164 } 2165 plen = m->m_pkthdr.len - sizeof(struct ip6_hdr); 2166 ip6 = mtod(m, struct ip6_hdr *); 2167 ip6->ip6_nxt = IPPROTO_ICMPV6; 2168 icmp6 = (struct icmp6_hdr *)(ip6 + 1); 2169 type = icmp6->icmp6_type; /* keep type for statistics */ 2170 code = icmp6->icmp6_code; /* ditto. */ 2171 hlim = 0; 2172 srcp = NULL; 2173 2174 /* 2175 * If the incoming packet was addressed directly to us (i.e. unicast), 2176 * use dst as the src for the reply. 2177 * The IN6_IFF_NOTREADY case should be VERY rare, but is possible 2178 * (for example) when we encounter an error while forwarding procedure 2179 * destined to a duplicated address of ours. 2180 */ 2181 if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 2182 ia = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */); 2183 if (ia != NULL && !(ia->ia6_flags & 2184 (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) { 2185 src6 = ia->ia_addr.sin6_addr; 2186 srcp = &src6; 2187 2188 if (m->m_pkthdr.rcvif != NULL) { 2189 /* XXX: This may not be the outgoing interface */ 2190 hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim; 2191 } else 2192 hlim = V_ip6_defhlim; 2193 } 2194 if (ia != NULL) 2195 ifa_free(&ia->ia_ifa); 2196 } 2197 2198 if (srcp == NULL) { 2199 int error; 2200 struct in6_addr dst6; 2201 uint32_t scopeid; 2202 2203 /* 2204 * This case matches to multicasts, our anycast, or unicasts 2205 * that we do not own. Select a source address based on the 2206 * source address of the erroneous packet. 2207 */ 2208 in6_splitscope(&ip6->ip6_dst, &dst6, &scopeid); 2209 error = in6_selectsrc_addr(RT_DEFAULT_FIB, &dst6, 2210 scopeid, NULL, &src6, &hlim); 2211 2212 if (error) { 2213 char ip6buf[INET6_ADDRSTRLEN]; 2214 nd6log((LOG_DEBUG, 2215 "icmp6_reflect: source can't be determined: " 2216 "dst=%s, error=%d\n", 2217 ip6_sprintf(ip6buf, &ip6->ip6_dst), error)); 2218 goto bad; 2219 } 2220 srcp = &src6; 2221 } 2222 /* 2223 * ip6_input() drops a packet if its src is multicast. 2224 * So, the src is never multicast. 2225 */ 2226 ip6->ip6_dst = ip6->ip6_src; 2227 ip6->ip6_src = *srcp; 2228 ip6->ip6_flow = 0; 2229 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2230 ip6->ip6_vfc |= IPV6_VERSION; 2231 ip6->ip6_nxt = IPPROTO_ICMPV6; 2232 ip6->ip6_hlim = hlim; 2233 2234 icmp6->icmp6_cksum = 0; 2235 icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2236 sizeof(struct ip6_hdr), plen); 2237 2238 /* 2239 * XXX option handling 2240 */ 2241 2242 m->m_flags &= ~(M_BCAST|M_MCAST); 2243 2244 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2245 if (outif) 2246 icmp6_ifoutstat_inc(outif, type, code); 2247 2248 return; 2249 2250 bad: 2251 m_freem(m); 2252 return; 2253 } 2254 2255 void 2256 icmp6_fasttimo(void) 2257 { 2258 2259 mld_fasttimo(); 2260 } 2261 2262 void 2263 icmp6_slowtimo(void) 2264 { 2265 2266 mld_slowtimo(); 2267 } 2268 2269 static const char * 2270 icmp6_redirect_diag(struct in6_addr *src6, struct in6_addr *dst6, 2271 struct in6_addr *tgt6) 2272 { 2273 static char buf[1024]; 2274 char ip6bufs[INET6_ADDRSTRLEN]; 2275 char ip6bufd[INET6_ADDRSTRLEN]; 2276 char ip6buft[INET6_ADDRSTRLEN]; 2277 snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)", 2278 ip6_sprintf(ip6bufs, src6), ip6_sprintf(ip6bufd, dst6), 2279 ip6_sprintf(ip6buft, tgt6)); 2280 return buf; 2281 } 2282 2283 void 2284 icmp6_redirect_input(struct mbuf *m, int off) 2285 { 2286 struct ifnet *ifp; 2287 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 2288 struct nd_redirect *nd_rd; 2289 int icmp6len = ntohs(ip6->ip6_plen); 2290 char *lladdr = NULL; 2291 int lladdrlen = 0; 2292 int is_router; 2293 int is_onlink; 2294 struct in6_addr src6 = ip6->ip6_src; 2295 struct in6_addr redtgt6; 2296 struct in6_addr reddst6; 2297 union nd_opts ndopts; 2298 char ip6buf[INET6_ADDRSTRLEN]; 2299 2300 M_ASSERTPKTHDR(m); 2301 KASSERT(m->m_pkthdr.rcvif != NULL, ("%s: no rcvif", __func__)); 2302 2303 ifp = m->m_pkthdr.rcvif; 2304 2305 /* XXX if we are router, we don't update route by icmp6 redirect */ 2306 if (V_ip6_forwarding) 2307 goto freeit; 2308 if (!V_icmp6_rediraccept) 2309 goto freeit; 2310 2311 #ifndef PULLDOWN_TEST 2312 IP6_EXTHDR_CHECK(m, off, icmp6len,); 2313 nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off); 2314 #else 2315 IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len); 2316 if (nd_rd == NULL) { 2317 ICMP6STAT_INC(icp6s_tooshort); 2318 return; 2319 } 2320 #endif 2321 redtgt6 = nd_rd->nd_rd_target; 2322 reddst6 = nd_rd->nd_rd_dst; 2323 2324 if (in6_setscope(&redtgt6, m->m_pkthdr.rcvif, NULL) || 2325 in6_setscope(&reddst6, m->m_pkthdr.rcvif, NULL)) { 2326 goto freeit; 2327 } 2328 2329 /* validation */ 2330 if (!IN6_IS_ADDR_LINKLOCAL(&src6)) { 2331 nd6log((LOG_ERR, 2332 "ICMP6 redirect sent from %s rejected; " 2333 "must be from linklocal\n", 2334 ip6_sprintf(ip6buf, &src6))); 2335 goto bad; 2336 } 2337 if (ip6->ip6_hlim != 255) { 2338 nd6log((LOG_ERR, 2339 "ICMP6 redirect sent from %s rejected; " 2340 "hlim=%d (must be 255)\n", 2341 ip6_sprintf(ip6buf, &src6), ip6->ip6_hlim)); 2342 goto bad; 2343 } 2344 { 2345 /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */ 2346 struct nhop6_basic nh6; 2347 struct in6_addr kdst; 2348 uint32_t scopeid; 2349 2350 in6_splitscope(&reddst6, &kdst, &scopeid); 2351 if (fib6_lookup_nh_basic(RT_DEFAULT_FIB, &kdst, scopeid, 0, 0,&nh6)==0){ 2352 if ((nh6.nh_flags & NHF_GATEWAY) == 0) { 2353 nd6log((LOG_ERR, 2354 "ICMP6 redirect rejected; no route " 2355 "with inet6 gateway found for redirect dst: %s\n", 2356 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2357 goto bad; 2358 } 2359 2360 if (IN6_ARE_ADDR_EQUAL(&src6, &nh6.nh_addr) == 0) { 2361 nd6log((LOG_ERR, 2362 "ICMP6 redirect rejected; " 2363 "not equal to gw-for-src=%s (must be same): " 2364 "%s\n", 2365 ip6_sprintf(ip6buf, &nh6.nh_addr), 2366 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2367 goto bad; 2368 } 2369 } else { 2370 nd6log((LOG_ERR, 2371 "ICMP6 redirect rejected; " 2372 "no route found for redirect dst: %s\n", 2373 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2374 goto bad; 2375 } 2376 } 2377 if (IN6_IS_ADDR_MULTICAST(&reddst6)) { 2378 nd6log((LOG_ERR, 2379 "ICMP6 redirect rejected; " 2380 "redirect dst must be unicast: %s\n", 2381 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2382 goto bad; 2383 } 2384 2385 is_router = is_onlink = 0; 2386 if (IN6_IS_ADDR_LINKLOCAL(&redtgt6)) 2387 is_router = 1; /* router case */ 2388 if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0) 2389 is_onlink = 1; /* on-link destination case */ 2390 if (!is_router && !is_onlink) { 2391 nd6log((LOG_ERR, 2392 "ICMP6 redirect rejected; " 2393 "neither router case nor onlink case: %s\n", 2394 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2395 goto bad; 2396 } 2397 2398 icmp6len -= sizeof(*nd_rd); 2399 nd6_option_init(nd_rd + 1, icmp6len, &ndopts); 2400 if (nd6_options(&ndopts) < 0) { 2401 nd6log((LOG_INFO, "%s: invalid ND option, rejected: %s\n", 2402 __func__, icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2403 /* nd6_options have incremented stats */ 2404 goto freeit; 2405 } 2406 2407 if (ndopts.nd_opts_tgt_lladdr) { 2408 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 2409 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 2410 } 2411 2412 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 2413 nd6log((LOG_INFO, "%s: lladdrlen mismatch for %s " 2414 "(if %d, icmp6 packet %d): %s\n", 2415 __func__, ip6_sprintf(ip6buf, &redtgt6), 2416 ifp->if_addrlen, lladdrlen - 2, 2417 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2418 goto bad; 2419 } 2420 2421 /* Validation passed. */ 2422 2423 /* RFC 2461 8.3 */ 2424 nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT, 2425 is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER); 2426 2427 /* 2428 * Install a gateway route in the better-router case or an interface 2429 * route in the on-link-destination case. 2430 */ 2431 { 2432 struct sockaddr_in6 sdst; 2433 struct sockaddr_in6 sgw; 2434 struct sockaddr_in6 ssrc; 2435 struct sockaddr *gw; 2436 int rt_flags; 2437 u_int fibnum; 2438 2439 bzero(&sdst, sizeof(sdst)); 2440 bzero(&ssrc, sizeof(ssrc)); 2441 sdst.sin6_family = ssrc.sin6_family = AF_INET6; 2442 sdst.sin6_len = ssrc.sin6_len = sizeof(struct sockaddr_in6); 2443 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr)); 2444 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr)); 2445 rt_flags = RTF_HOST; 2446 if (is_router) { 2447 bzero(&sgw, sizeof(sgw)); 2448 sgw.sin6_family = AF_INET6; 2449 sgw.sin6_len = sizeof(struct sockaddr_in6); 2450 bcopy(&redtgt6, &sgw.sin6_addr, 2451 sizeof(struct in6_addr)); 2452 gw = (struct sockaddr *)&sgw; 2453 rt_flags |= RTF_GATEWAY; 2454 } else 2455 gw = ifp->if_addr->ifa_addr; 2456 for (fibnum = 0; fibnum < rt_numfibs; fibnum++) 2457 in6_rtredirect((struct sockaddr *)&sdst, gw, 2458 (struct sockaddr *)NULL, rt_flags, 2459 (struct sockaddr *)&ssrc, fibnum); 2460 } 2461 /* finally update cached route in each socket via pfctlinput */ 2462 { 2463 struct sockaddr_in6 sdst; 2464 2465 bzero(&sdst, sizeof(sdst)); 2466 sdst.sin6_family = AF_INET6; 2467 sdst.sin6_len = sizeof(struct sockaddr_in6); 2468 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr)); 2469 pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst); 2470 } 2471 2472 freeit: 2473 m_freem(m); 2474 return; 2475 2476 bad: 2477 ICMP6STAT_INC(icp6s_badredirect); 2478 m_freem(m); 2479 } 2480 2481 void 2482 icmp6_redirect_output(struct mbuf *m0, struct rtentry *rt) 2483 { 2484 struct ifnet *ifp; /* my outgoing interface */ 2485 struct in6_addr *ifp_ll6; 2486 struct in6_addr *router_ll6; 2487 struct ip6_hdr *sip6; /* m0 as struct ip6_hdr */ 2488 struct mbuf *m = NULL; /* newly allocated one */ 2489 struct m_tag *mtag; 2490 struct ip6_hdr *ip6; /* m as struct ip6_hdr */ 2491 struct nd_redirect *nd_rd; 2492 struct llentry *ln = NULL; 2493 size_t maxlen; 2494 u_char *p; 2495 struct ifnet *outif = NULL; 2496 struct sockaddr_in6 src_sa; 2497 2498 icmp6_errcount(ND_REDIRECT, 0); 2499 2500 /* if we are not router, we don't send icmp6 redirect */ 2501 if (!V_ip6_forwarding) 2502 goto fail; 2503 2504 /* sanity check */ 2505 if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp)) 2506 goto fail; 2507 2508 /* 2509 * Address check: 2510 * the source address must identify a neighbor, and 2511 * the destination address must not be a multicast address 2512 * [RFC 2461, sec 8.2] 2513 */ 2514 sip6 = mtod(m0, struct ip6_hdr *); 2515 bzero(&src_sa, sizeof(src_sa)); 2516 src_sa.sin6_family = AF_INET6; 2517 src_sa.sin6_len = sizeof(src_sa); 2518 src_sa.sin6_addr = sip6->ip6_src; 2519 if (nd6_is_addr_neighbor(&src_sa, ifp) == 0) 2520 goto fail; 2521 if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst)) 2522 goto fail; /* what should we do here? */ 2523 2524 /* rate limit */ 2525 if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0)) 2526 goto fail; 2527 2528 /* 2529 * Since we are going to append up to 1280 bytes (= IPV6_MMTU), 2530 * we almost always ask for an mbuf cluster for simplicity. 2531 * (MHLEN < IPV6_MMTU is almost always true) 2532 */ 2533 #if IPV6_MMTU >= MCLBYTES 2534 # error assumption failed about IPV6_MMTU and MCLBYTES 2535 #endif 2536 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 2537 if (m == NULL) 2538 goto fail; 2539 M_SETFIB(m, rt->rt_fibnum); 2540 maxlen = M_TRAILINGSPACE(m); 2541 maxlen = min(IPV6_MMTU, maxlen); 2542 /* just for safety */ 2543 if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) + 2544 ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) { 2545 goto fail; 2546 } 2547 2548 { 2549 /* get ip6 linklocal address for ifp(my outgoing interface). */ 2550 struct in6_ifaddr *ia; 2551 if ((ia = in6ifa_ifpforlinklocal(ifp, 2552 IN6_IFF_NOTREADY| 2553 IN6_IFF_ANYCAST)) == NULL) 2554 goto fail; 2555 ifp_ll6 = &ia->ia_addr.sin6_addr; 2556 /* XXXRW: reference released prematurely. */ 2557 ifa_free(&ia->ia_ifa); 2558 } 2559 2560 /* get ip6 linklocal address for the router. */ 2561 if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) { 2562 struct sockaddr_in6 *sin6; 2563 sin6 = (struct sockaddr_in6 *)rt->rt_gateway; 2564 router_ll6 = &sin6->sin6_addr; 2565 if (!IN6_IS_ADDR_LINKLOCAL(router_ll6)) 2566 router_ll6 = (struct in6_addr *)NULL; 2567 } else 2568 router_ll6 = (struct in6_addr *)NULL; 2569 2570 /* ip6 */ 2571 ip6 = mtod(m, struct ip6_hdr *); 2572 ip6->ip6_flow = 0; 2573 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2574 ip6->ip6_vfc |= IPV6_VERSION; 2575 /* ip6->ip6_plen will be set later */ 2576 ip6->ip6_nxt = IPPROTO_ICMPV6; 2577 ip6->ip6_hlim = 255; 2578 /* ip6->ip6_src must be linklocal addr for my outgoing if. */ 2579 bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr)); 2580 bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr)); 2581 2582 /* ND Redirect */ 2583 nd_rd = (struct nd_redirect *)(ip6 + 1); 2584 nd_rd->nd_rd_type = ND_REDIRECT; 2585 nd_rd->nd_rd_code = 0; 2586 nd_rd->nd_rd_reserved = 0; 2587 if (rt->rt_flags & RTF_GATEWAY) { 2588 /* 2589 * nd_rd->nd_rd_target must be a link-local address in 2590 * better router cases. 2591 */ 2592 if (!router_ll6) 2593 goto fail; 2594 bcopy(router_ll6, &nd_rd->nd_rd_target, 2595 sizeof(nd_rd->nd_rd_target)); 2596 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2597 sizeof(nd_rd->nd_rd_dst)); 2598 } else { 2599 /* make sure redtgt == reddst */ 2600 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target, 2601 sizeof(nd_rd->nd_rd_target)); 2602 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2603 sizeof(nd_rd->nd_rd_dst)); 2604 } 2605 2606 p = (u_char *)(nd_rd + 1); 2607 2608 if (!router_ll6) 2609 goto nolladdropt; 2610 2611 { 2612 /* target lladdr option */ 2613 int len; 2614 struct nd_opt_hdr *nd_opt; 2615 char *lladdr; 2616 2617 IF_AFDATA_RLOCK(ifp); 2618 ln = nd6_lookup(router_ll6, 0, ifp); 2619 IF_AFDATA_RUNLOCK(ifp); 2620 if (ln == NULL) 2621 goto nolladdropt; 2622 2623 len = sizeof(*nd_opt) + ifp->if_addrlen; 2624 len = (len + 7) & ~7; /* round by 8 */ 2625 /* safety check */ 2626 if (len + (p - (u_char *)ip6) > maxlen) 2627 goto nolladdropt; 2628 2629 if (ln->la_flags & LLE_VALID) { 2630 nd_opt = (struct nd_opt_hdr *)p; 2631 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 2632 nd_opt->nd_opt_len = len >> 3; 2633 lladdr = (char *)(nd_opt + 1); 2634 bcopy(ln->ll_addr, lladdr, ifp->if_addrlen); 2635 p += len; 2636 } 2637 } 2638 nolladdropt: 2639 if (ln != NULL) 2640 LLE_RUNLOCK(ln); 2641 2642 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2643 2644 /* just to be safe */ 2645 #ifdef M_DECRYPTED /*not openbsd*/ 2646 if (m0->m_flags & M_DECRYPTED) 2647 goto noredhdropt; 2648 #endif 2649 if (p - (u_char *)ip6 > maxlen) 2650 goto noredhdropt; 2651 2652 { 2653 /* redirected header option */ 2654 int len; 2655 struct nd_opt_rd_hdr *nd_opt_rh; 2656 2657 /* 2658 * compute the maximum size for icmp6 redirect header option. 2659 * XXX room for auth header? 2660 */ 2661 len = maxlen - (p - (u_char *)ip6); 2662 len &= ~7; 2663 2664 /* This is just for simplicity. */ 2665 if (m0->m_pkthdr.len != m0->m_len) { 2666 if (m0->m_next) { 2667 m_freem(m0->m_next); 2668 m0->m_next = NULL; 2669 } 2670 m0->m_pkthdr.len = m0->m_len; 2671 } 2672 2673 /* 2674 * Redirected header option spec (RFC2461 4.6.3) talks nothing 2675 * about padding/truncate rule for the original IP packet. 2676 * From the discussion on IPv6imp in Feb 1999, 2677 * the consensus was: 2678 * - "attach as much as possible" is the goal 2679 * - pad if not aligned (original size can be guessed by 2680 * original ip6 header) 2681 * Following code adds the padding if it is simple enough, 2682 * and truncates if not. 2683 */ 2684 if (m0->m_next || m0->m_pkthdr.len != m0->m_len) 2685 panic("assumption failed in %s:%d", __FILE__, 2686 __LINE__); 2687 2688 if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) { 2689 /* not enough room, truncate */ 2690 m0->m_pkthdr.len = m0->m_len = len - 2691 sizeof(*nd_opt_rh); 2692 } else { 2693 /* enough room, pad or truncate */ 2694 size_t extra; 2695 2696 extra = m0->m_pkthdr.len % 8; 2697 if (extra) { 2698 /* pad if easy enough, truncate if not */ 2699 if (8 - extra <= M_TRAILINGSPACE(m0)) { 2700 /* pad */ 2701 m0->m_len += (8 - extra); 2702 m0->m_pkthdr.len += (8 - extra); 2703 } else { 2704 /* truncate */ 2705 m0->m_pkthdr.len -= extra; 2706 m0->m_len -= extra; 2707 } 2708 } 2709 len = m0->m_pkthdr.len + sizeof(*nd_opt_rh); 2710 m0->m_pkthdr.len = m0->m_len = len - 2711 sizeof(*nd_opt_rh); 2712 } 2713 2714 nd_opt_rh = (struct nd_opt_rd_hdr *)p; 2715 bzero(nd_opt_rh, sizeof(*nd_opt_rh)); 2716 nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER; 2717 nd_opt_rh->nd_opt_rh_len = len >> 3; 2718 p += sizeof(*nd_opt_rh); 2719 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2720 2721 /* connect m0 to m */ 2722 m_tag_delete_chain(m0, NULL); 2723 m0->m_flags &= ~M_PKTHDR; 2724 m->m_next = m0; 2725 m->m_pkthdr.len = m->m_len + m0->m_len; 2726 m0 = NULL; 2727 } 2728 noredhdropt:; 2729 if (m0) { 2730 m_freem(m0); 2731 m0 = NULL; 2732 } 2733 2734 /* XXX: clear embedded link IDs in the inner header */ 2735 in6_clearscope(&sip6->ip6_src); 2736 in6_clearscope(&sip6->ip6_dst); 2737 in6_clearscope(&nd_rd->nd_rd_target); 2738 in6_clearscope(&nd_rd->nd_rd_dst); 2739 2740 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr)); 2741 2742 nd_rd->nd_rd_cksum = 0; 2743 nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2744 sizeof(*ip6), ntohs(ip6->ip6_plen)); 2745 2746 if (send_sendso_input_hook != NULL) { 2747 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, sizeof(unsigned short), 2748 M_NOWAIT); 2749 if (mtag == NULL) 2750 goto fail; 2751 *(unsigned short *)(mtag + 1) = nd_rd->nd_rd_type; 2752 m_tag_prepend(m, mtag); 2753 } 2754 2755 /* send the packet to outside... */ 2756 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2757 if (outif) { 2758 icmp6_ifstat_inc(outif, ifs6_out_msg); 2759 icmp6_ifstat_inc(outif, ifs6_out_redirect); 2760 } 2761 ICMP6STAT_INC(icp6s_outhist[ND_REDIRECT]); 2762 2763 return; 2764 2765 fail: 2766 if (m) 2767 m_freem(m); 2768 if (m0) 2769 m_freem(m0); 2770 } 2771 2772 /* 2773 * ICMPv6 socket option processing. 2774 */ 2775 int 2776 icmp6_ctloutput(struct socket *so, struct sockopt *sopt) 2777 { 2778 int error = 0; 2779 int optlen; 2780 struct inpcb *inp = sotoinpcb(so); 2781 int level, op, optname; 2782 2783 if (sopt) { 2784 level = sopt->sopt_level; 2785 op = sopt->sopt_dir; 2786 optname = sopt->sopt_name; 2787 optlen = sopt->sopt_valsize; 2788 } else 2789 level = op = optname = optlen = 0; 2790 2791 if (level != IPPROTO_ICMPV6) { 2792 return EINVAL; 2793 } 2794 2795 switch (op) { 2796 case PRCO_SETOPT: 2797 switch (optname) { 2798 case ICMP6_FILTER: 2799 { 2800 struct icmp6_filter ic6f; 2801 2802 if (optlen != sizeof(ic6f)) { 2803 error = EMSGSIZE; 2804 break; 2805 } 2806 error = sooptcopyin(sopt, &ic6f, optlen, optlen); 2807 if (error == 0) { 2808 INP_WLOCK(inp); 2809 *inp->in6p_icmp6filt = ic6f; 2810 INP_WUNLOCK(inp); 2811 } 2812 break; 2813 } 2814 2815 default: 2816 error = ENOPROTOOPT; 2817 break; 2818 } 2819 break; 2820 2821 case PRCO_GETOPT: 2822 switch (optname) { 2823 case ICMP6_FILTER: 2824 { 2825 struct icmp6_filter ic6f; 2826 2827 INP_RLOCK(inp); 2828 ic6f = *inp->in6p_icmp6filt; 2829 INP_RUNLOCK(inp); 2830 error = sooptcopyout(sopt, &ic6f, sizeof(ic6f)); 2831 break; 2832 } 2833 2834 default: 2835 error = ENOPROTOOPT; 2836 break; 2837 } 2838 break; 2839 } 2840 2841 return (error); 2842 } 2843 2844 /* 2845 * Perform rate limit check. 2846 * Returns 0 if it is okay to send the icmp6 packet. 2847 * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate 2848 * limitation. 2849 * 2850 * XXX per-destination/type check necessary? 2851 * 2852 * dst - not used at this moment 2853 * type - not used at this moment 2854 * code - not used at this moment 2855 */ 2856 static int 2857 icmp6_ratelimit(const struct in6_addr *dst, const int type, 2858 const int code) 2859 { 2860 int ret; 2861 2862 ret = 0; /* okay to send */ 2863 2864 /* PPS limit */ 2865 if (!ppsratecheck(&V_icmp6errppslim_last, &V_icmp6errpps_count, 2866 V_icmp6errppslim)) { 2867 /* The packet is subject to rate limit */ 2868 ret++; 2869 } 2870 2871 return ret; 2872 }
Cache object: b3697f5eae08a8fe2ffcd4af4476f9bd
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