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 #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_ifattach.h> 104 #include <netinet6/in6_pcb.h> 105 #include <netinet6/ip6protosw.h> 106 #include <netinet6/ip6_var.h> 107 #include <netinet6/scope6_var.h> 108 #include <netinet6/mld6_var.h> 109 #include <netinet6/nd6.h> 110 #include <netinet6/send.h> 111 112 extern struct domain inet6domain; 113 114 VNET_PCPUSTAT_DEFINE(struct icmp6stat, icmp6stat); 115 VNET_PCPUSTAT_SYSINIT(icmp6stat); 116 117 #ifdef VIMAGE 118 VNET_PCPUSTAT_SYSUNINIT(icmp6stat); 119 #endif /* VIMAGE */ 120 121 VNET_DECLARE(struct inpcbinfo, ripcbinfo); 122 VNET_DECLARE(struct inpcbhead, ripcb); 123 VNET_DECLARE(int, icmp6errppslim); 124 static VNET_DEFINE(int, icmp6errpps_count) = 0; 125 static VNET_DEFINE(struct timeval, icmp6errppslim_last); 126 VNET_DECLARE(int, icmp6_nodeinfo); 127 128 #define V_ripcbinfo VNET(ripcbinfo) 129 #define V_ripcb VNET(ripcb) 130 #define V_icmp6errppslim VNET(icmp6errppslim) 131 #define V_icmp6errpps_count VNET(icmp6errpps_count) 132 #define V_icmp6errppslim_last VNET(icmp6errppslim_last) 133 #define V_icmp6_nodeinfo VNET(icmp6_nodeinfo) 134 135 static void icmp6_errcount(int, int); 136 static int icmp6_rip6_input(struct mbuf **, int); 137 static int icmp6_ratelimit(const struct in6_addr *, const int, const int); 138 static const char *icmp6_redirect_diag(struct in6_addr *, 139 struct in6_addr *, struct in6_addr *); 140 static struct mbuf *ni6_input(struct mbuf *, int); 141 static struct mbuf *ni6_nametodns(const char *, int, int); 142 static int ni6_dnsmatch(const char *, int, const char *, int); 143 static int ni6_addrs(struct icmp6_nodeinfo *, struct mbuf *, 144 struct ifnet **, struct in6_addr *); 145 static int ni6_store_addrs(struct icmp6_nodeinfo *, struct icmp6_nodeinfo *, 146 struct ifnet *, int); 147 static int icmp6_notify_error(struct mbuf **, int, int, int); 148 149 /* 150 * Kernel module interface for updating icmp6stat. The argument is an index 151 * into icmp6stat treated as an array of u_quad_t. While this encodes the 152 * general layout of icmp6stat into the caller, it doesn't encode its 153 * location, so that future changes to add, for example, per-CPU stats 154 * support won't cause binary compatibility problems for kernel modules. 155 */ 156 void 157 kmod_icmp6stat_inc(int statnum) 158 { 159 160 counter_u64_add(VNET(icmp6stat)[statnum], 1); 161 } 162 163 static void 164 icmp6_errcount(int type, int code) 165 { 166 switch (type) { 167 case ICMP6_DST_UNREACH: 168 switch (code) { 169 case ICMP6_DST_UNREACH_NOROUTE: 170 ICMP6STAT_INC(icp6s_odst_unreach_noroute); 171 return; 172 case ICMP6_DST_UNREACH_ADMIN: 173 ICMP6STAT_INC(icp6s_odst_unreach_admin); 174 return; 175 case ICMP6_DST_UNREACH_BEYONDSCOPE: 176 ICMP6STAT_INC(icp6s_odst_unreach_beyondscope); 177 return; 178 case ICMP6_DST_UNREACH_ADDR: 179 ICMP6STAT_INC(icp6s_odst_unreach_addr); 180 return; 181 case ICMP6_DST_UNREACH_NOPORT: 182 ICMP6STAT_INC(icp6s_odst_unreach_noport); 183 return; 184 } 185 break; 186 case ICMP6_PACKET_TOO_BIG: 187 ICMP6STAT_INC(icp6s_opacket_too_big); 188 return; 189 case ICMP6_TIME_EXCEEDED: 190 switch (code) { 191 case ICMP6_TIME_EXCEED_TRANSIT: 192 ICMP6STAT_INC(icp6s_otime_exceed_transit); 193 return; 194 case ICMP6_TIME_EXCEED_REASSEMBLY: 195 ICMP6STAT_INC(icp6s_otime_exceed_reassembly); 196 return; 197 } 198 break; 199 case ICMP6_PARAM_PROB: 200 switch (code) { 201 case ICMP6_PARAMPROB_HEADER: 202 ICMP6STAT_INC(icp6s_oparamprob_header); 203 return; 204 case ICMP6_PARAMPROB_NEXTHEADER: 205 ICMP6STAT_INC(icp6s_oparamprob_nextheader); 206 return; 207 case ICMP6_PARAMPROB_OPTION: 208 ICMP6STAT_INC(icp6s_oparamprob_option); 209 return; 210 } 211 break; 212 case ND_REDIRECT: 213 ICMP6STAT_INC(icp6s_oredirect); 214 return; 215 } 216 ICMP6STAT_INC(icp6s_ounknown); 217 } 218 219 /* 220 * A wrapper function for icmp6_error() necessary when the erroneous packet 221 * may not contain enough scope zone information. 222 */ 223 void 224 icmp6_error2(struct mbuf *m, int type, int code, int param, 225 struct ifnet *ifp) 226 { 227 struct ip6_hdr *ip6; 228 229 if (ifp == NULL) 230 return; 231 232 #ifndef PULLDOWN_TEST 233 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), ); 234 #else 235 if (m->m_len < sizeof(struct ip6_hdr)) { 236 m = m_pullup(m, sizeof(struct ip6_hdr)); 237 if (m == NULL) 238 return; 239 } 240 #endif 241 242 ip6 = mtod(m, struct ip6_hdr *); 243 244 if (in6_setscope(&ip6->ip6_src, ifp, NULL) != 0) 245 return; 246 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0) 247 return; 248 249 icmp6_error(m, type, code, param); 250 } 251 252 /* 253 * Generate an error packet of type error in response to bad IP6 packet. 254 */ 255 void 256 icmp6_error(struct mbuf *m, int type, int code, int param) 257 { 258 struct ip6_hdr *oip6, *nip6; 259 struct icmp6_hdr *icmp6; 260 u_int preplen; 261 int off; 262 int nxt; 263 264 ICMP6STAT_INC(icp6s_error); 265 266 /* count per-type-code statistics */ 267 icmp6_errcount(type, code); 268 269 #ifdef M_DECRYPTED /*not openbsd*/ 270 if (m->m_flags & M_DECRYPTED) { 271 ICMP6STAT_INC(icp6s_canterror); 272 goto freeit; 273 } 274 #endif 275 276 #ifndef PULLDOWN_TEST 277 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), ); 278 #else 279 if (m->m_len < sizeof(struct ip6_hdr)) { 280 m = m_pullup(m, sizeof(struct ip6_hdr)); 281 if (m == NULL) 282 return; 283 } 284 #endif 285 oip6 = mtod(m, struct ip6_hdr *); 286 287 /* 288 * If the destination address of the erroneous packet is a multicast 289 * address, or the packet was sent using link-layer multicast, 290 * we should basically suppress sending an error (RFC 2463, Section 291 * 2.4). 292 * We have two exceptions (the item e.2 in that section): 293 * - the Packet Too Big message can be sent for path MTU discovery. 294 * - the Parameter Problem Message that can be allowed an icmp6 error 295 * in the option type field. This check has been done in 296 * ip6_unknown_opt(), so we can just check the type and code. 297 */ 298 if ((m->m_flags & (M_BCAST|M_MCAST) || 299 IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) && 300 (type != ICMP6_PACKET_TOO_BIG && 301 (type != ICMP6_PARAM_PROB || 302 code != ICMP6_PARAMPROB_OPTION))) 303 goto freeit; 304 305 /* 306 * RFC 2463, 2.4 (e.5): source address check. 307 * XXX: the case of anycast source? 308 */ 309 if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) || 310 IN6_IS_ADDR_MULTICAST(&oip6->ip6_src)) 311 goto freeit; 312 313 /* 314 * If we are about to send ICMPv6 against ICMPv6 error/redirect, 315 * don't do it. 316 */ 317 nxt = -1; 318 off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt); 319 if (off >= 0 && nxt == IPPROTO_ICMPV6) { 320 struct icmp6_hdr *icp; 321 322 #ifndef PULLDOWN_TEST 323 IP6_EXTHDR_CHECK(m, 0, off + sizeof(struct icmp6_hdr), ); 324 icp = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 325 #else 326 IP6_EXTHDR_GET(icp, struct icmp6_hdr *, m, off, 327 sizeof(*icp)); 328 if (icp == NULL) { 329 ICMP6STAT_INC(icp6s_tooshort); 330 return; 331 } 332 #endif 333 if (icp->icmp6_type < ICMP6_ECHO_REQUEST || 334 icp->icmp6_type == ND_REDIRECT) { 335 /* 336 * ICMPv6 error 337 * Special case: for redirect (which is 338 * informational) we must not send icmp6 error. 339 */ 340 ICMP6STAT_INC(icp6s_canterror); 341 goto freeit; 342 } else { 343 /* ICMPv6 informational - send the error */ 344 } 345 } else { 346 /* non-ICMPv6 - send the error */ 347 } 348 349 oip6 = mtod(m, struct ip6_hdr *); /* adjust pointer */ 350 351 /* Finally, do rate limitation check. */ 352 if (icmp6_ratelimit(&oip6->ip6_src, type, code)) { 353 ICMP6STAT_INC(icp6s_toofreq); 354 goto freeit; 355 } 356 357 /* 358 * OK, ICMP6 can be generated. 359 */ 360 361 if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN) 362 m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len); 363 364 preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 365 M_PREPEND(m, preplen, M_NOWAIT); /* FIB is also copied over. */ 366 if (m == NULL) { 367 nd6log((LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__)); 368 return; 369 } 370 371 nip6 = mtod(m, struct ip6_hdr *); 372 nip6->ip6_src = oip6->ip6_src; 373 nip6->ip6_dst = oip6->ip6_dst; 374 375 in6_clearscope(&oip6->ip6_src); 376 in6_clearscope(&oip6->ip6_dst); 377 378 icmp6 = (struct icmp6_hdr *)(nip6 + 1); 379 icmp6->icmp6_type = type; 380 icmp6->icmp6_code = code; 381 icmp6->icmp6_pptr = htonl((u_int32_t)param); 382 383 /* 384 * icmp6_reflect() is designed to be in the input path. 385 * icmp6_error() can be called from both input and output path, 386 * and if we are in output path rcvif could contain bogus value. 387 * clear m->m_pkthdr.rcvif for safety, we should have enough scope 388 * information in ip header (nip6). 389 */ 390 m->m_pkthdr.rcvif = NULL; 391 392 ICMP6STAT_INC(icp6s_outhist[type]); 393 icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */ 394 395 return; 396 397 freeit: 398 /* 399 * If we can't tell whether or not we can generate ICMP6, free it. 400 */ 401 m_freem(m); 402 } 403 404 /* 405 * Process a received ICMP6 message. 406 */ 407 int 408 icmp6_input(struct mbuf **mp, int *offp, int proto) 409 { 410 struct mbuf *m = *mp, *n; 411 struct ifnet *ifp; 412 struct ip6_hdr *ip6, *nip6; 413 struct icmp6_hdr *icmp6, *nicmp6; 414 int off = *offp; 415 int icmp6len = m->m_pkthdr.len - *offp; 416 int code, sum, noff; 417 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 418 int ip6len, error; 419 420 ifp = m->m_pkthdr.rcvif; 421 422 #ifndef PULLDOWN_TEST 423 IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_hdr), IPPROTO_DONE); 424 /* m might change if M_LOOP. So, call mtod after this */ 425 #endif 426 427 /* 428 * Locate icmp6 structure in mbuf, and check 429 * that not corrupted and of at least minimum length 430 */ 431 432 ip6 = mtod(m, struct ip6_hdr *); 433 ip6len = sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen); 434 if (icmp6len < sizeof(struct icmp6_hdr)) { 435 ICMP6STAT_INC(icp6s_tooshort); 436 goto freeit; 437 } 438 439 /* 440 * Check multicast group membership. 441 * Note: SSM filters are not applied for ICMPv6 traffic. 442 */ 443 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 444 struct in6_multi *inm; 445 446 inm = in6m_lookup(ifp, &ip6->ip6_dst); 447 if (inm == NULL) { 448 IP6STAT_INC(ip6s_notmember); 449 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 450 goto freeit; 451 } 452 } 453 454 /* 455 * calculate the checksum 456 */ 457 #ifndef PULLDOWN_TEST 458 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off); 459 #else 460 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6)); 461 if (icmp6 == NULL) { 462 ICMP6STAT_INC(icp6s_tooshort); 463 return IPPROTO_DONE; 464 } 465 #endif 466 code = icmp6->icmp6_code; 467 468 if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) { 469 nd6log((LOG_ERR, 470 "ICMP6 checksum error(%d|%x) %s\n", 471 icmp6->icmp6_type, sum, 472 ip6_sprintf(ip6bufs, &ip6->ip6_src))); 473 ICMP6STAT_INC(icp6s_checksum); 474 goto freeit; 475 } 476 477 ICMP6STAT_INC(icp6s_inhist[icmp6->icmp6_type]); 478 icmp6_ifstat_inc(ifp, ifs6_in_msg); 479 if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK) 480 icmp6_ifstat_inc(ifp, ifs6_in_error); 481 482 switch (icmp6->icmp6_type) { 483 case ICMP6_DST_UNREACH: 484 icmp6_ifstat_inc(ifp, ifs6_in_dstunreach); 485 switch (code) { 486 case ICMP6_DST_UNREACH_NOROUTE: 487 code = PRC_UNREACH_NET; 488 break; 489 case ICMP6_DST_UNREACH_ADMIN: 490 icmp6_ifstat_inc(ifp, ifs6_in_adminprohib); 491 code = PRC_UNREACH_PROTOCOL; /* is this a good code? */ 492 break; 493 case ICMP6_DST_UNREACH_ADDR: 494 code = PRC_HOSTDEAD; 495 break; 496 case ICMP6_DST_UNREACH_BEYONDSCOPE: 497 /* I mean "source address was incorrect." */ 498 code = PRC_PARAMPROB; 499 break; 500 case ICMP6_DST_UNREACH_NOPORT: 501 code = PRC_UNREACH_PORT; 502 break; 503 default: 504 goto badcode; 505 } 506 goto deliver; 507 break; 508 509 case ICMP6_PACKET_TOO_BIG: 510 icmp6_ifstat_inc(ifp, ifs6_in_pkttoobig); 511 512 /* validation is made in icmp6_mtudisc_update */ 513 514 code = PRC_MSGSIZE; 515 516 /* 517 * Updating the path MTU will be done after examining 518 * intermediate extension headers. 519 */ 520 goto deliver; 521 break; 522 523 case ICMP6_TIME_EXCEEDED: 524 icmp6_ifstat_inc(ifp, ifs6_in_timeexceed); 525 switch (code) { 526 case ICMP6_TIME_EXCEED_TRANSIT: 527 code = PRC_TIMXCEED_INTRANS; 528 break; 529 case ICMP6_TIME_EXCEED_REASSEMBLY: 530 code = PRC_TIMXCEED_REASS; 531 break; 532 default: 533 goto badcode; 534 } 535 goto deliver; 536 break; 537 538 case ICMP6_PARAM_PROB: 539 icmp6_ifstat_inc(ifp, ifs6_in_paramprob); 540 switch (code) { 541 case ICMP6_PARAMPROB_NEXTHEADER: 542 code = PRC_UNREACH_PROTOCOL; 543 break; 544 case ICMP6_PARAMPROB_HEADER: 545 case ICMP6_PARAMPROB_OPTION: 546 code = PRC_PARAMPROB; 547 break; 548 default: 549 goto badcode; 550 } 551 goto deliver; 552 break; 553 554 case ICMP6_ECHO_REQUEST: 555 icmp6_ifstat_inc(ifp, ifs6_in_echo); 556 if (code != 0) 557 goto badcode; 558 if ((n = m_copy(m, 0, M_COPYALL)) == NULL) { 559 /* Give up remote */ 560 break; 561 } 562 if (!M_WRITABLE(n) 563 || n->m_len < off + sizeof(struct icmp6_hdr)) { 564 struct mbuf *n0 = n; 565 int n0len; 566 567 CTASSERT(sizeof(*nip6) + sizeof(*nicmp6) <= MHLEN); 568 n = m_gethdr(M_NOWAIT, n0->m_type); 569 if (n == NULL) { 570 /* Give up remote */ 571 m_freem(n0); 572 break; 573 } 574 575 m_move_pkthdr(n, n0); /* FIB copied. */ 576 n0len = n0->m_pkthdr.len; /* save for use below */ 577 /* 578 * Copy IPv6 and ICMPv6 only. 579 */ 580 nip6 = mtod(n, struct ip6_hdr *); 581 bcopy(ip6, nip6, sizeof(struct ip6_hdr)); 582 nicmp6 = (struct icmp6_hdr *)(nip6 + 1); 583 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr)); 584 noff = sizeof(struct ip6_hdr); 585 /* new mbuf contains only ipv6+icmpv6 headers */ 586 n->m_len = noff + sizeof(struct icmp6_hdr); 587 /* 588 * Adjust mbuf. ip6_plen will be adjusted in 589 * ip6_output(). 590 */ 591 m_adj(n0, off + sizeof(struct icmp6_hdr)); 592 /* recalculate complete packet size */ 593 n->m_pkthdr.len = n0len + (noff - off); 594 n->m_next = n0; 595 } else { 596 nip6 = mtod(n, struct ip6_hdr *); 597 IP6_EXTHDR_GET(nicmp6, struct icmp6_hdr *, n, off, 598 sizeof(*nicmp6)); 599 noff = off; 600 } 601 nicmp6->icmp6_type = ICMP6_ECHO_REPLY; 602 nicmp6->icmp6_code = 0; 603 if (n) { 604 ICMP6STAT_INC(icp6s_reflect); 605 ICMP6STAT_INC(icp6s_outhist[ICMP6_ECHO_REPLY]); 606 icmp6_reflect(n, noff); 607 } 608 break; 609 610 case ICMP6_ECHO_REPLY: 611 icmp6_ifstat_inc(ifp, ifs6_in_echoreply); 612 if (code != 0) 613 goto badcode; 614 break; 615 616 case MLD_LISTENER_QUERY: 617 case MLD_LISTENER_REPORT: 618 case MLD_LISTENER_DONE: 619 case MLDV2_LISTENER_REPORT: 620 /* 621 * Drop MLD traffic which is not link-local, has a hop limit 622 * of greater than 1 hop, or which does not have the 623 * IPv6 HBH Router Alert option. 624 * As IPv6 HBH options are stripped in ip6_input() we must 625 * check an mbuf header flag. 626 * XXX Should we also sanity check that these messages 627 * were directed to a link-local multicast prefix? 628 */ 629 if ((ip6->ip6_hlim != 1) || (m->m_flags & M_RTALERT_MLD) == 0) 630 goto freeit; 631 if (mld_input(m, off, icmp6len) != 0) 632 return (IPPROTO_DONE); 633 /* m stays. */ 634 break; 635 636 case ICMP6_WRUREQUEST: /* ICMP6_FQDN_QUERY */ 637 { 638 enum { WRU, FQDN } mode; 639 640 if (!V_icmp6_nodeinfo) 641 break; 642 643 if (icmp6len == sizeof(struct icmp6_hdr) + 4) 644 mode = WRU; 645 else if (icmp6len >= sizeof(struct icmp6_nodeinfo)) 646 mode = FQDN; 647 else 648 goto badlen; 649 650 if (mode == FQDN) { 651 #ifndef PULLDOWN_TEST 652 IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_nodeinfo), 653 IPPROTO_DONE); 654 #endif 655 n = m_copy(m, 0, M_COPYALL); 656 if (n) 657 n = ni6_input(n, off); 658 /* XXX meaningless if n == NULL */ 659 noff = sizeof(struct ip6_hdr); 660 } else { 661 struct prison *pr; 662 u_char *p; 663 int maxhlen, hlen; 664 665 /* 666 * XXX: this combination of flags is pointless, 667 * but should we keep this for compatibility? 668 */ 669 if ((V_icmp6_nodeinfo & 5) != 5) 670 break; 671 672 if (code != 0) 673 goto badcode; 674 675 CTASSERT(sizeof(*nip6) + sizeof(*nicmp6) + 4 <= MHLEN); 676 n = m_gethdr(M_NOWAIT, m->m_type); 677 if (n == NULL) { 678 /* Give up remote */ 679 break; 680 } 681 if (!m_dup_pkthdr(n, m, M_NOWAIT)) { 682 /* 683 * Previous code did a blind M_COPY_PKTHDR 684 * and said "just for rcvif". If true, then 685 * we could tolerate the dup failing (due to 686 * the deep copy of the tag chain). For now 687 * be conservative and just fail. 688 */ 689 m_free(n); 690 n = NULL; 691 } 692 maxhlen = M_TRAILINGSPACE(n) - 693 (sizeof(*nip6) + sizeof(*nicmp6) + 4); 694 pr = curthread->td_ucred->cr_prison; 695 mtx_lock(&pr->pr_mtx); 696 hlen = strlen(pr->pr_hostname); 697 if (maxhlen > hlen) 698 maxhlen = hlen; 699 /* 700 * Copy IPv6 and ICMPv6 only. 701 */ 702 nip6 = mtod(n, struct ip6_hdr *); 703 bcopy(ip6, nip6, sizeof(struct ip6_hdr)); 704 nicmp6 = (struct icmp6_hdr *)(nip6 + 1); 705 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr)); 706 p = (u_char *)(nicmp6 + 1); 707 bzero(p, 4); 708 /* meaningless TTL */ 709 bcopy(pr->pr_hostname, p + 4, maxhlen); 710 mtx_unlock(&pr->pr_mtx); 711 noff = sizeof(struct ip6_hdr); 712 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + 713 sizeof(struct icmp6_hdr) + 4 + maxhlen; 714 nicmp6->icmp6_type = ICMP6_WRUREPLY; 715 nicmp6->icmp6_code = 0; 716 } 717 if (n) { 718 ICMP6STAT_INC(icp6s_reflect); 719 ICMP6STAT_INC(icp6s_outhist[ICMP6_WRUREPLY]); 720 icmp6_reflect(n, noff); 721 } 722 break; 723 } 724 725 case ICMP6_WRUREPLY: 726 if (code != 0) 727 goto badcode; 728 break; 729 730 case ND_ROUTER_SOLICIT: 731 icmp6_ifstat_inc(ifp, ifs6_in_routersolicit); 732 if (code != 0) 733 goto badcode; 734 if (icmp6len < sizeof(struct nd_router_solicit)) 735 goto badlen; 736 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) { 737 /* give up local */ 738 739 /* Send incoming SeND packet to user space. */ 740 if (send_sendso_input_hook != NULL) { 741 IP6_EXTHDR_CHECK(m, off, 742 icmp6len, IPPROTO_DONE); 743 error = send_sendso_input_hook(m, ifp, 744 SND_IN, ip6len); 745 /* -1 == no app on SEND socket */ 746 if (error == 0) 747 return (IPPROTO_DONE); 748 nd6_rs_input(m, off, icmp6len); 749 } else 750 nd6_rs_input(m, off, icmp6len); 751 m = NULL; 752 goto freeit; 753 } 754 if (send_sendso_input_hook != NULL) { 755 IP6_EXTHDR_CHECK(n, off, 756 icmp6len, IPPROTO_DONE); 757 error = send_sendso_input_hook(n, ifp, 758 SND_IN, ip6len); 759 if (error == 0) 760 goto freeit; 761 /* -1 == no app on SEND socket */ 762 nd6_rs_input(n, off, icmp6len); 763 } else 764 nd6_rs_input(n, off, icmp6len); 765 /* m stays. */ 766 break; 767 768 case ND_ROUTER_ADVERT: 769 icmp6_ifstat_inc(ifp, ifs6_in_routeradvert); 770 if (code != 0) 771 goto badcode; 772 if (icmp6len < sizeof(struct nd_router_advert)) 773 goto badlen; 774 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) { 775 776 /* Send incoming SeND-protected/ND packet to user space. */ 777 if (send_sendso_input_hook != NULL) { 778 error = send_sendso_input_hook(m, ifp, 779 SND_IN, ip6len); 780 if (error == 0) 781 return (IPPROTO_DONE); 782 nd6_ra_input(m, off, icmp6len); 783 } else 784 nd6_ra_input(m, off, icmp6len); 785 m = NULL; 786 goto freeit; 787 } 788 if (send_sendso_input_hook != NULL) { 789 error = send_sendso_input_hook(n, ifp, 790 SND_IN, ip6len); 791 if (error == 0) 792 goto freeit; 793 nd6_ra_input(n, off, icmp6len); 794 } else 795 nd6_ra_input(n, off, icmp6len); 796 /* m stays. */ 797 break; 798 799 case ND_NEIGHBOR_SOLICIT: 800 icmp6_ifstat_inc(ifp, ifs6_in_neighborsolicit); 801 if (code != 0) 802 goto badcode; 803 if (icmp6len < sizeof(struct nd_neighbor_solicit)) 804 goto badlen; 805 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) { 806 if (send_sendso_input_hook != NULL) { 807 error = send_sendso_input_hook(m, ifp, 808 SND_IN, ip6len); 809 if (error == 0) 810 return (IPPROTO_DONE); 811 nd6_ns_input(m, off, icmp6len); 812 } else 813 nd6_ns_input(m, off, icmp6len); 814 m = NULL; 815 goto freeit; 816 } 817 if (send_sendso_input_hook != NULL) { 818 error = send_sendso_input_hook(n, ifp, 819 SND_IN, ip6len); 820 if (error == 0) 821 goto freeit; 822 nd6_ns_input(n, off, icmp6len); 823 } else 824 nd6_ns_input(n, off, icmp6len); 825 /* m stays. */ 826 break; 827 828 case ND_NEIGHBOR_ADVERT: 829 icmp6_ifstat_inc(ifp, ifs6_in_neighboradvert); 830 if (code != 0) 831 goto badcode; 832 if (icmp6len < sizeof(struct nd_neighbor_advert)) 833 goto badlen; 834 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) { 835 836 /* Send incoming SeND-protected/ND packet to user space. */ 837 if (send_sendso_input_hook != NULL) { 838 error = send_sendso_input_hook(m, ifp, 839 SND_IN, ip6len); 840 if (error == 0) 841 return (IPPROTO_DONE); 842 nd6_na_input(m, off, icmp6len); 843 } else 844 nd6_na_input(m, off, icmp6len); 845 m = NULL; 846 goto freeit; 847 } 848 if (send_sendso_input_hook != NULL) { 849 error = send_sendso_input_hook(n, ifp, 850 SND_IN, ip6len); 851 if (error == 0) 852 goto freeit; 853 nd6_na_input(n, off, icmp6len); 854 } else 855 nd6_na_input(n, off, icmp6len); 856 /* m stays. */ 857 break; 858 859 case ND_REDIRECT: 860 icmp6_ifstat_inc(ifp, ifs6_in_redirect); 861 if (code != 0) 862 goto badcode; 863 if (icmp6len < sizeof(struct nd_redirect)) 864 goto badlen; 865 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) { 866 if (send_sendso_input_hook != NULL) { 867 error = send_sendso_input_hook(m, ifp, 868 SND_IN, ip6len); 869 if (error == 0) 870 return (IPPROTO_DONE); 871 icmp6_redirect_input(m, off); 872 } else 873 icmp6_redirect_input(m, off); 874 m = NULL; 875 goto freeit; 876 } 877 if (send_sendso_input_hook != NULL) { 878 error = send_sendso_input_hook(n, ifp, 879 SND_IN, ip6len); 880 if (error == 0) 881 goto freeit; 882 icmp6_redirect_input(n, off); 883 } else 884 icmp6_redirect_input(n, off); 885 /* m stays. */ 886 break; 887 888 case ICMP6_ROUTER_RENUMBERING: 889 if (code != ICMP6_ROUTER_RENUMBERING_COMMAND && 890 code != ICMP6_ROUTER_RENUMBERING_RESULT) 891 goto badcode; 892 if (icmp6len < sizeof(struct icmp6_router_renum)) 893 goto badlen; 894 break; 895 896 default: 897 nd6log((LOG_DEBUG, 898 "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n", 899 icmp6->icmp6_type, ip6_sprintf(ip6bufs, &ip6->ip6_src), 900 ip6_sprintf(ip6bufd, &ip6->ip6_dst), 901 ifp ? ifp->if_index : 0)); 902 if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) { 903 /* ICMPv6 error: MUST deliver it by spec... */ 904 code = PRC_NCMDS; 905 /* deliver */ 906 } else { 907 /* ICMPv6 informational: MUST not deliver */ 908 break; 909 } 910 deliver: 911 if (icmp6_notify_error(&m, off, icmp6len, code) != 0) { 912 /* In this case, m should've been freed. */ 913 return (IPPROTO_DONE); 914 } 915 break; 916 917 badcode: 918 ICMP6STAT_INC(icp6s_badcode); 919 break; 920 921 badlen: 922 ICMP6STAT_INC(icp6s_badlen); 923 break; 924 } 925 926 /* deliver the packet to appropriate sockets */ 927 icmp6_rip6_input(&m, *offp); 928 929 return IPPROTO_DONE; 930 931 freeit: 932 m_freem(m); 933 return IPPROTO_DONE; 934 } 935 936 static int 937 icmp6_notify_error(struct mbuf **mp, int off, int icmp6len, int code) 938 { 939 struct mbuf *m = *mp; 940 struct icmp6_hdr *icmp6; 941 struct ip6_hdr *eip6; 942 u_int32_t notifymtu; 943 struct sockaddr_in6 icmp6src, icmp6dst; 944 945 if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) { 946 ICMP6STAT_INC(icp6s_tooshort); 947 goto freeit; 948 } 949 #ifndef PULLDOWN_TEST 950 IP6_EXTHDR_CHECK(m, off, 951 sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr), -1); 952 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 953 #else 954 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, 955 sizeof(*icmp6) + sizeof(struct ip6_hdr)); 956 if (icmp6 == NULL) { 957 ICMP6STAT_INC(icp6s_tooshort); 958 return (-1); 959 } 960 #endif 961 eip6 = (struct ip6_hdr *)(icmp6 + 1); 962 963 /* Detect the upper level protocol */ 964 { 965 void (*ctlfunc)(int, struct sockaddr *, void *); 966 u_int8_t nxt = eip6->ip6_nxt; 967 int eoff = off + sizeof(struct icmp6_hdr) + 968 sizeof(struct ip6_hdr); 969 struct ip6ctlparam ip6cp; 970 struct in6_addr *finaldst = NULL; 971 int icmp6type = icmp6->icmp6_type; 972 struct ip6_frag *fh; 973 struct ip6_rthdr *rth; 974 struct ip6_rthdr0 *rth0; 975 int rthlen; 976 977 while (1) { /* XXX: should avoid infinite loop explicitly? */ 978 struct ip6_ext *eh; 979 980 switch (nxt) { 981 case IPPROTO_HOPOPTS: 982 case IPPROTO_DSTOPTS: 983 case IPPROTO_AH: 984 #ifndef PULLDOWN_TEST 985 IP6_EXTHDR_CHECK(m, 0, 986 eoff + sizeof(struct ip6_ext), -1); 987 eh = (struct ip6_ext *)(mtod(m, caddr_t) + eoff); 988 #else 989 IP6_EXTHDR_GET(eh, struct ip6_ext *, m, 990 eoff, sizeof(*eh)); 991 if (eh == NULL) { 992 ICMP6STAT_INC(icp6s_tooshort); 993 return (-1); 994 } 995 #endif 996 997 if (nxt == IPPROTO_AH) 998 eoff += (eh->ip6e_len + 2) << 2; 999 else 1000 eoff += (eh->ip6e_len + 1) << 3; 1001 nxt = eh->ip6e_nxt; 1002 break; 1003 case IPPROTO_ROUTING: 1004 /* 1005 * When the erroneous packet contains a 1006 * routing header, we should examine the 1007 * header to determine the final destination. 1008 * Otherwise, we can't properly update 1009 * information that depends on the final 1010 * destination (e.g. path MTU). 1011 */ 1012 #ifndef PULLDOWN_TEST 1013 IP6_EXTHDR_CHECK(m, 0, eoff + sizeof(*rth), -1); 1014 rth = (struct ip6_rthdr *) 1015 (mtod(m, caddr_t) + eoff); 1016 #else 1017 IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m, 1018 eoff, sizeof(*rth)); 1019 if (rth == NULL) { 1020 ICMP6STAT_INC(icp6s_tooshort); 1021 return (-1); 1022 } 1023 #endif 1024 rthlen = (rth->ip6r_len + 1) << 3; 1025 /* 1026 * XXX: currently there is no 1027 * officially defined type other 1028 * than type-0. 1029 * Note that if the segment left field 1030 * is 0, all intermediate hops must 1031 * have been passed. 1032 */ 1033 if (rth->ip6r_segleft && 1034 rth->ip6r_type == IPV6_RTHDR_TYPE_0) { 1035 int hops; 1036 1037 #ifndef PULLDOWN_TEST 1038 IP6_EXTHDR_CHECK(m, 0, eoff + rthlen, -1); 1039 rth0 = (struct ip6_rthdr0 *) 1040 (mtod(m, caddr_t) + eoff); 1041 #else 1042 IP6_EXTHDR_GET(rth0, 1043 struct ip6_rthdr0 *, m, 1044 eoff, rthlen); 1045 if (rth0 == NULL) { 1046 ICMP6STAT_INC(icp6s_tooshort); 1047 return (-1); 1048 } 1049 #endif 1050 /* just ignore a bogus header */ 1051 if ((rth0->ip6r0_len % 2) == 0 && 1052 (hops = rth0->ip6r0_len/2)) 1053 finaldst = (struct in6_addr *)(rth0 + 1) + (hops - 1); 1054 } 1055 eoff += rthlen; 1056 nxt = rth->ip6r_nxt; 1057 break; 1058 case IPPROTO_FRAGMENT: 1059 #ifndef PULLDOWN_TEST 1060 IP6_EXTHDR_CHECK(m, 0, eoff + 1061 sizeof(struct ip6_frag), -1); 1062 fh = (struct ip6_frag *)(mtod(m, caddr_t) + 1063 eoff); 1064 #else 1065 IP6_EXTHDR_GET(fh, struct ip6_frag *, m, 1066 eoff, sizeof(*fh)); 1067 if (fh == NULL) { 1068 ICMP6STAT_INC(icp6s_tooshort); 1069 return (-1); 1070 } 1071 #endif 1072 /* 1073 * Data after a fragment header is meaningless 1074 * unless it is the first fragment, but 1075 * we'll go to the notify label for path MTU 1076 * discovery. 1077 */ 1078 if (fh->ip6f_offlg & IP6F_OFF_MASK) 1079 goto notify; 1080 1081 eoff += sizeof(struct ip6_frag); 1082 nxt = fh->ip6f_nxt; 1083 break; 1084 default: 1085 /* 1086 * This case includes ESP and the No Next 1087 * Header. In such cases going to the notify 1088 * label does not have any meaning 1089 * (i.e. ctlfunc will be NULL), but we go 1090 * anyway since we might have to update 1091 * path MTU information. 1092 */ 1093 goto notify; 1094 } 1095 } 1096 notify: 1097 #ifndef PULLDOWN_TEST 1098 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 1099 #else 1100 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, 1101 sizeof(*icmp6) + sizeof(struct ip6_hdr)); 1102 if (icmp6 == NULL) { 1103 ICMP6STAT_INC(icp6s_tooshort); 1104 return (-1); 1105 } 1106 #endif 1107 1108 /* 1109 * retrieve parameters from the inner IPv6 header, and convert 1110 * them into sockaddr structures. 1111 * XXX: there is no guarantee that the source or destination 1112 * addresses of the inner packet are in the same scope as 1113 * the addresses of the icmp packet. But there is no other 1114 * way to determine the zone. 1115 */ 1116 eip6 = (struct ip6_hdr *)(icmp6 + 1); 1117 1118 bzero(&icmp6dst, sizeof(icmp6dst)); 1119 icmp6dst.sin6_len = sizeof(struct sockaddr_in6); 1120 icmp6dst.sin6_family = AF_INET6; 1121 if (finaldst == NULL) 1122 icmp6dst.sin6_addr = eip6->ip6_dst; 1123 else 1124 icmp6dst.sin6_addr = *finaldst; 1125 if (in6_setscope(&icmp6dst.sin6_addr, m->m_pkthdr.rcvif, NULL)) 1126 goto freeit; 1127 bzero(&icmp6src, sizeof(icmp6src)); 1128 icmp6src.sin6_len = sizeof(struct sockaddr_in6); 1129 icmp6src.sin6_family = AF_INET6; 1130 icmp6src.sin6_addr = eip6->ip6_src; 1131 if (in6_setscope(&icmp6src.sin6_addr, m->m_pkthdr.rcvif, NULL)) 1132 goto freeit; 1133 icmp6src.sin6_flowinfo = 1134 (eip6->ip6_flow & IPV6_FLOWLABEL_MASK); 1135 1136 if (finaldst == NULL) 1137 finaldst = &eip6->ip6_dst; 1138 ip6cp.ip6c_m = m; 1139 ip6cp.ip6c_icmp6 = icmp6; 1140 ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1); 1141 ip6cp.ip6c_off = eoff; 1142 ip6cp.ip6c_finaldst = finaldst; 1143 ip6cp.ip6c_src = &icmp6src; 1144 ip6cp.ip6c_nxt = nxt; 1145 1146 if (icmp6type == ICMP6_PACKET_TOO_BIG) { 1147 notifymtu = ntohl(icmp6->icmp6_mtu); 1148 ip6cp.ip6c_cmdarg = (void *)¬ifymtu; 1149 icmp6_mtudisc_update(&ip6cp, 1); /*XXX*/ 1150 } 1151 1152 ctlfunc = (void (*)(int, struct sockaddr *, void *)) 1153 (inet6sw[ip6_protox[nxt]].pr_ctlinput); 1154 if (ctlfunc) { 1155 (void) (*ctlfunc)(code, (struct sockaddr *)&icmp6dst, 1156 &ip6cp); 1157 } 1158 } 1159 *mp = m; 1160 return (0); 1161 1162 freeit: 1163 m_freem(m); 1164 return (-1); 1165 } 1166 1167 void 1168 icmp6_mtudisc_update(struct ip6ctlparam *ip6cp, int validated) 1169 { 1170 struct in6_addr *dst = ip6cp->ip6c_finaldst; 1171 struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6; 1172 struct mbuf *m = ip6cp->ip6c_m; /* will be necessary for scope issue */ 1173 u_int mtu = ntohl(icmp6->icmp6_mtu); 1174 struct in_conninfo inc; 1175 1176 #if 0 1177 /* 1178 * RFC2460 section 5, last paragraph. 1179 * even though minimum link MTU for IPv6 is IPV6_MMTU, 1180 * we may see ICMPv6 too big with mtu < IPV6_MMTU 1181 * due to packet translator in the middle. 1182 * see ip6_output() and ip6_getpmtu() "alwaysfrag" case for 1183 * special handling. 1184 */ 1185 if (mtu < IPV6_MMTU) 1186 return; 1187 #endif 1188 1189 /* 1190 * we reject ICMPv6 too big with abnormally small value. 1191 * XXX what is the good definition of "abnormally small"? 1192 */ 1193 if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8) 1194 return; 1195 1196 if (!validated) 1197 return; 1198 1199 /* 1200 * In case the suggested mtu is less than IPV6_MMTU, we 1201 * only need to remember that it was for above mentioned 1202 * "alwaysfrag" case. 1203 * Try to be as close to the spec as possible. 1204 */ 1205 if (mtu < IPV6_MMTU) 1206 mtu = IPV6_MMTU - 8; 1207 1208 bzero(&inc, sizeof(inc)); 1209 inc.inc_fibnum = M_GETFIB(m); 1210 inc.inc_flags |= INC_ISIPV6; 1211 inc.inc6_faddr = *dst; 1212 if (in6_setscope(&inc.inc6_faddr, m->m_pkthdr.rcvif, NULL)) 1213 return; 1214 1215 if (mtu < tcp_maxmtu6(&inc, NULL)) { 1216 tcp_hc_updatemtu(&inc, mtu); 1217 ICMP6STAT_INC(icp6s_pmtuchg); 1218 } 1219 } 1220 1221 /* 1222 * Process a Node Information Query packet, based on 1223 * draft-ietf-ipngwg-icmp-name-lookups-07. 1224 * 1225 * Spec incompatibilities: 1226 * - IPv6 Subject address handling 1227 * - IPv4 Subject address handling support missing 1228 * - Proxy reply (answer even if it's not for me) 1229 * - joins NI group address at in6_ifattach() time only, does not cope 1230 * with hostname changes by sethostname(3) 1231 */ 1232 static struct mbuf * 1233 ni6_input(struct mbuf *m, int off) 1234 { 1235 struct icmp6_nodeinfo *ni6, *nni6; 1236 struct mbuf *n = NULL; 1237 struct prison *pr; 1238 u_int16_t qtype; 1239 int subjlen; 1240 int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); 1241 struct ni_reply_fqdn *fqdn; 1242 int addrs; /* for NI_QTYPE_NODEADDR */ 1243 struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */ 1244 struct in6_addr in6_subj; /* subject address */ 1245 struct ip6_hdr *ip6; 1246 int oldfqdn = 0; /* if 1, return pascal string (03 draft) */ 1247 char *subj = NULL; 1248 struct in6_ifaddr *ia6 = NULL; 1249 1250 ip6 = mtod(m, struct ip6_hdr *); 1251 #ifndef PULLDOWN_TEST 1252 ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off); 1253 #else 1254 IP6_EXTHDR_GET(ni6, struct icmp6_nodeinfo *, m, off, sizeof(*ni6)); 1255 if (ni6 == NULL) { 1256 /* m is already reclaimed */ 1257 return (NULL); 1258 } 1259 #endif 1260 1261 /* 1262 * Validate IPv6 source address. 1263 * The default configuration MUST be to refuse answering queries from 1264 * global-scope addresses according to RFC4602. 1265 * Notes: 1266 * - it's not very clear what "refuse" means; this implementation 1267 * simply drops it. 1268 * - it's not very easy to identify global-scope (unicast) addresses 1269 * since there are many prefixes for them. It should be safer 1270 * and in practice sufficient to check "all" but loopback and 1271 * link-local (note that site-local unicast was deprecated and 1272 * ULA is defined as global scope-wise) 1273 */ 1274 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_GLOBALOK) == 0 && 1275 !IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) && 1276 !IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) 1277 goto bad; 1278 1279 /* 1280 * Validate IPv6 destination address. 1281 * 1282 * The Responder must discard the Query without further processing 1283 * unless it is one of the Responder's unicast or anycast addresses, or 1284 * a link-local scope multicast address which the Responder has joined. 1285 * [RFC4602, Section 5.] 1286 */ 1287 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 1288 if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst)) 1289 goto bad; 1290 /* else it's a link-local multicast, fine */ 1291 } else { /* unicast or anycast */ 1292 ia6 = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */); 1293 if (ia6 == NULL) 1294 goto bad; /* XXX impossible */ 1295 1296 if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) && 1297 !(V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK)) { 1298 ifa_free(&ia6->ia_ifa); 1299 nd6log((LOG_DEBUG, "ni6_input: ignore node info to " 1300 "a temporary address in %s:%d", 1301 __FILE__, __LINE__)); 1302 goto bad; 1303 } 1304 ifa_free(&ia6->ia_ifa); 1305 } 1306 1307 /* validate query Subject field. */ 1308 qtype = ntohs(ni6->ni_qtype); 1309 subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo); 1310 switch (qtype) { 1311 case NI_QTYPE_NOOP: 1312 case NI_QTYPE_SUPTYPES: 1313 /* 07 draft */ 1314 if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0) 1315 break; 1316 /* FALLTHROUGH */ 1317 case NI_QTYPE_FQDN: 1318 case NI_QTYPE_NODEADDR: 1319 case NI_QTYPE_IPV4ADDR: 1320 switch (ni6->ni_code) { 1321 case ICMP6_NI_SUBJ_IPV6: 1322 #if ICMP6_NI_SUBJ_IPV6 != 0 1323 case 0: 1324 #endif 1325 /* 1326 * backward compatibility - try to accept 03 draft 1327 * format, where no Subject is present. 1328 */ 1329 if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 && 1330 subjlen == 0) { 1331 oldfqdn++; 1332 break; 1333 } 1334 #if ICMP6_NI_SUBJ_IPV6 != 0 1335 if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6) 1336 goto bad; 1337 #endif 1338 1339 if (subjlen != sizeof(struct in6_addr)) 1340 goto bad; 1341 1342 /* 1343 * Validate Subject address. 1344 * 1345 * Not sure what exactly "address belongs to the node" 1346 * means in the spec, is it just unicast, or what? 1347 * 1348 * At this moment we consider Subject address as 1349 * "belong to the node" if the Subject address equals 1350 * to the IPv6 destination address; validation for 1351 * IPv6 destination address should have done enough 1352 * check for us. 1353 * 1354 * We do not do proxy at this moment. 1355 */ 1356 /* m_pulldown instead of copy? */ 1357 m_copydata(m, off + sizeof(struct icmp6_nodeinfo), 1358 subjlen, (caddr_t)&in6_subj); 1359 if (in6_setscope(&in6_subj, m->m_pkthdr.rcvif, NULL)) 1360 goto bad; 1361 1362 subj = (char *)&in6_subj; 1363 if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &in6_subj)) 1364 break; 1365 1366 /* 1367 * XXX if we are to allow other cases, we should really 1368 * be careful about scope here. 1369 * basically, we should disallow queries toward IPv6 1370 * destination X with subject Y, 1371 * if scope(X) > scope(Y). 1372 * if we allow scope(X) > scope(Y), it will result in 1373 * information leakage across scope boundary. 1374 */ 1375 goto bad; 1376 1377 case ICMP6_NI_SUBJ_FQDN: 1378 /* 1379 * Validate Subject name with gethostname(3). 1380 * 1381 * The behavior may need some debate, since: 1382 * - we are not sure if the node has FQDN as 1383 * hostname (returned by gethostname(3)). 1384 * - the code does wildcard match for truncated names. 1385 * however, we are not sure if we want to perform 1386 * wildcard match, if gethostname(3) side has 1387 * truncated hostname. 1388 */ 1389 pr = curthread->td_ucred->cr_prison; 1390 mtx_lock(&pr->pr_mtx); 1391 n = ni6_nametodns(pr->pr_hostname, 1392 strlen(pr->pr_hostname), 0); 1393 mtx_unlock(&pr->pr_mtx); 1394 if (!n || n->m_next || n->m_len == 0) 1395 goto bad; 1396 IP6_EXTHDR_GET(subj, char *, m, 1397 off + sizeof(struct icmp6_nodeinfo), subjlen); 1398 if (subj == NULL) 1399 goto bad; 1400 if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *), 1401 n->m_len)) { 1402 goto bad; 1403 } 1404 m_freem(n); 1405 n = NULL; 1406 break; 1407 1408 case ICMP6_NI_SUBJ_IPV4: /* XXX: to be implemented? */ 1409 default: 1410 goto bad; 1411 } 1412 break; 1413 } 1414 1415 /* refuse based on configuration. XXX ICMP6_NI_REFUSED? */ 1416 switch (qtype) { 1417 case NI_QTYPE_FQDN: 1418 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_FQDNOK) == 0) 1419 goto bad; 1420 break; 1421 case NI_QTYPE_NODEADDR: 1422 case NI_QTYPE_IPV4ADDR: 1423 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_NODEADDROK) == 0) 1424 goto bad; 1425 break; 1426 } 1427 1428 /* guess reply length */ 1429 switch (qtype) { 1430 case NI_QTYPE_NOOP: 1431 break; /* no reply data */ 1432 case NI_QTYPE_SUPTYPES: 1433 replylen += sizeof(u_int32_t); 1434 break; 1435 case NI_QTYPE_FQDN: 1436 /* XXX will append an mbuf */ 1437 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); 1438 break; 1439 case NI_QTYPE_NODEADDR: 1440 addrs = ni6_addrs(ni6, m, &ifp, (struct in6_addr *)subj); 1441 if ((replylen += addrs * (sizeof(struct in6_addr) + 1442 sizeof(u_int32_t))) > MCLBYTES) 1443 replylen = MCLBYTES; /* XXX: will truncate pkt later */ 1444 break; 1445 case NI_QTYPE_IPV4ADDR: 1446 /* unsupported - should respond with unknown Qtype? */ 1447 break; 1448 default: 1449 /* 1450 * XXX: We must return a reply with the ICMP6 code 1451 * `unknown Qtype' in this case. However we regard the case 1452 * as an FQDN query for backward compatibility. 1453 * Older versions set a random value to this field, 1454 * so it rarely varies in the defined qtypes. 1455 * But the mechanism is not reliable... 1456 * maybe we should obsolete older versions. 1457 */ 1458 qtype = NI_QTYPE_FQDN; 1459 /* XXX will append an mbuf */ 1460 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); 1461 oldfqdn++; 1462 break; 1463 } 1464 1465 /* Allocate an mbuf to reply. */ 1466 if (replylen > MCLBYTES) { 1467 /* 1468 * XXX: should we try to allocate more? But MCLBYTES 1469 * is probably much larger than IPV6_MMTU... 1470 */ 1471 goto bad; 1472 } 1473 if (replylen > MHLEN) 1474 n = m_getcl(M_NOWAIT, m->m_type, M_PKTHDR); 1475 else 1476 n = m_gethdr(M_NOWAIT, m->m_type); 1477 if (n == NULL) { 1478 m_freem(m); 1479 return (NULL); 1480 } 1481 m_move_pkthdr(n, m); /* just for recvif and FIB */ 1482 n->m_pkthdr.len = n->m_len = replylen; 1483 1484 /* copy mbuf header and IPv6 + Node Information base headers */ 1485 bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr)); 1486 nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1); 1487 bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo)); 1488 1489 /* qtype dependent procedure */ 1490 switch (qtype) { 1491 case NI_QTYPE_NOOP: 1492 nni6->ni_code = ICMP6_NI_SUCCESS; 1493 nni6->ni_flags = 0; 1494 break; 1495 case NI_QTYPE_SUPTYPES: 1496 { 1497 u_int32_t v; 1498 nni6->ni_code = ICMP6_NI_SUCCESS; 1499 nni6->ni_flags = htons(0x0000); /* raw bitmap */ 1500 /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */ 1501 v = (u_int32_t)htonl(0x0000000f); 1502 bcopy(&v, nni6 + 1, sizeof(u_int32_t)); 1503 break; 1504 } 1505 case NI_QTYPE_FQDN: 1506 nni6->ni_code = ICMP6_NI_SUCCESS; 1507 fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) + 1508 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo)); 1509 nni6->ni_flags = 0; /* XXX: meaningless TTL */ 1510 fqdn->ni_fqdn_ttl = 0; /* ditto. */ 1511 /* 1512 * XXX do we really have FQDN in hostname? 1513 */ 1514 pr = curthread->td_ucred->cr_prison; 1515 mtx_lock(&pr->pr_mtx); 1516 n->m_next = ni6_nametodns(pr->pr_hostname, 1517 strlen(pr->pr_hostname), oldfqdn); 1518 mtx_unlock(&pr->pr_mtx); 1519 if (n->m_next == NULL) 1520 goto bad; 1521 /* XXX we assume that n->m_next is not a chain */ 1522 if (n->m_next->m_next != NULL) 1523 goto bad; 1524 n->m_pkthdr.len += n->m_next->m_len; 1525 break; 1526 case NI_QTYPE_NODEADDR: 1527 { 1528 int lenlim, copied; 1529 1530 nni6->ni_code = ICMP6_NI_SUCCESS; 1531 n->m_pkthdr.len = n->m_len = 1532 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); 1533 lenlim = M_TRAILINGSPACE(n); 1534 copied = ni6_store_addrs(ni6, nni6, ifp, lenlim); 1535 /* XXX: reset mbuf length */ 1536 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + 1537 sizeof(struct icmp6_nodeinfo) + copied; 1538 break; 1539 } 1540 default: 1541 break; /* XXX impossible! */ 1542 } 1543 1544 nni6->ni_type = ICMP6_NI_REPLY; 1545 m_freem(m); 1546 return (n); 1547 1548 bad: 1549 m_freem(m); 1550 if (n) 1551 m_freem(n); 1552 return (NULL); 1553 } 1554 1555 /* 1556 * make a mbuf with DNS-encoded string. no compression support. 1557 * 1558 * XXX names with less than 2 dots (like "foo" or "foo.section") will be 1559 * treated as truncated name (two \0 at the end). this is a wild guess. 1560 * 1561 * old - return pascal string if non-zero 1562 */ 1563 static struct mbuf * 1564 ni6_nametodns(const char *name, int namelen, int old) 1565 { 1566 struct mbuf *m; 1567 char *cp, *ep; 1568 const char *p, *q; 1569 int i, len, nterm; 1570 1571 if (old) 1572 len = namelen + 1; 1573 else 1574 len = MCLBYTES; 1575 1576 /* Because MAXHOSTNAMELEN is usually 256, we use cluster mbuf. */ 1577 if (len > MLEN) 1578 m = m_getcl(M_NOWAIT, MT_DATA, 0); 1579 else 1580 m = m_get(M_NOWAIT, MT_DATA); 1581 if (m == NULL) 1582 goto fail; 1583 1584 if (old) { 1585 m->m_len = len; 1586 *mtod(m, char *) = namelen; 1587 bcopy(name, mtod(m, char *) + 1, namelen); 1588 return m; 1589 } else { 1590 m->m_len = 0; 1591 cp = mtod(m, char *); 1592 ep = mtod(m, char *) + M_TRAILINGSPACE(m); 1593 1594 /* if not certain about my name, return empty buffer */ 1595 if (namelen == 0) 1596 return m; 1597 1598 /* 1599 * guess if it looks like shortened hostname, or FQDN. 1600 * shortened hostname needs two trailing "\0". 1601 */ 1602 i = 0; 1603 for (p = name; p < name + namelen; p++) { 1604 if (*p && *p == '.') 1605 i++; 1606 } 1607 if (i < 2) 1608 nterm = 2; 1609 else 1610 nterm = 1; 1611 1612 p = name; 1613 while (cp < ep && p < name + namelen) { 1614 i = 0; 1615 for (q = p; q < name + namelen && *q && *q != '.'; q++) 1616 i++; 1617 /* result does not fit into mbuf */ 1618 if (cp + i + 1 >= ep) 1619 goto fail; 1620 /* 1621 * DNS label length restriction, RFC1035 page 8. 1622 * "i == 0" case is included here to avoid returning 1623 * 0-length label on "foo..bar". 1624 */ 1625 if (i <= 0 || i >= 64) 1626 goto fail; 1627 *cp++ = i; 1628 bcopy(p, cp, i); 1629 cp += i; 1630 p = q; 1631 if (p < name + namelen && *p == '.') 1632 p++; 1633 } 1634 /* termination */ 1635 if (cp + nterm >= ep) 1636 goto fail; 1637 while (nterm-- > 0) 1638 *cp++ = '\0'; 1639 m->m_len = cp - mtod(m, char *); 1640 return m; 1641 } 1642 1643 panic("should not reach here"); 1644 /* NOTREACHED */ 1645 1646 fail: 1647 if (m) 1648 m_freem(m); 1649 return NULL; 1650 } 1651 1652 /* 1653 * check if two DNS-encoded string matches. takes care of truncated 1654 * form (with \0\0 at the end). no compression support. 1655 * XXX upper/lowercase match (see RFC2065) 1656 */ 1657 static int 1658 ni6_dnsmatch(const char *a, int alen, const char *b, int blen) 1659 { 1660 const char *a0, *b0; 1661 int l; 1662 1663 /* simplest case - need validation? */ 1664 if (alen == blen && bcmp(a, b, alen) == 0) 1665 return 1; 1666 1667 a0 = a; 1668 b0 = b; 1669 1670 /* termination is mandatory */ 1671 if (alen < 2 || blen < 2) 1672 return 0; 1673 if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0') 1674 return 0; 1675 alen--; 1676 blen--; 1677 1678 while (a - a0 < alen && b - b0 < blen) { 1679 if (a - a0 + 1 > alen || b - b0 + 1 > blen) 1680 return 0; 1681 1682 if ((signed char)a[0] < 0 || (signed char)b[0] < 0) 1683 return 0; 1684 /* we don't support compression yet */ 1685 if (a[0] >= 64 || b[0] >= 64) 1686 return 0; 1687 1688 /* truncated case */ 1689 if (a[0] == 0 && a - a0 == alen - 1) 1690 return 1; 1691 if (b[0] == 0 && b - b0 == blen - 1) 1692 return 1; 1693 if (a[0] == 0 || b[0] == 0) 1694 return 0; 1695 1696 if (a[0] != b[0]) 1697 return 0; 1698 l = a[0]; 1699 if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen) 1700 return 0; 1701 if (bcmp(a + 1, b + 1, l) != 0) 1702 return 0; 1703 1704 a += 1 + l; 1705 b += 1 + l; 1706 } 1707 1708 if (a - a0 == alen && b - b0 == blen) 1709 return 1; 1710 else 1711 return 0; 1712 } 1713 1714 /* 1715 * calculate the number of addresses to be returned in the node info reply. 1716 */ 1717 static int 1718 ni6_addrs(struct icmp6_nodeinfo *ni6, struct mbuf *m, struct ifnet **ifpp, 1719 struct in6_addr *subj) 1720 { 1721 struct ifnet *ifp; 1722 struct in6_ifaddr *ifa6; 1723 struct ifaddr *ifa; 1724 int addrs = 0, addrsofif, iffound = 0; 1725 int niflags = ni6->ni_flags; 1726 1727 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) { 1728 switch (ni6->ni_code) { 1729 case ICMP6_NI_SUBJ_IPV6: 1730 if (subj == NULL) /* must be impossible... */ 1731 return (0); 1732 break; 1733 default: 1734 /* 1735 * XXX: we only support IPv6 subject address for 1736 * this Qtype. 1737 */ 1738 return (0); 1739 } 1740 } 1741 1742 IFNET_RLOCK_NOSLEEP(); 1743 TAILQ_FOREACH(ifp, &V_ifnet, if_link) { 1744 addrsofif = 0; 1745 IF_ADDR_RLOCK(ifp); 1746 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 1747 if (ifa->ifa_addr->sa_family != AF_INET6) 1748 continue; 1749 ifa6 = (struct in6_ifaddr *)ifa; 1750 1751 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 && 1752 IN6_ARE_ADDR_EQUAL(subj, &ifa6->ia_addr.sin6_addr)) 1753 iffound = 1; 1754 1755 /* 1756 * IPv4-mapped addresses can only be returned by a 1757 * Node Information proxy, since they represent 1758 * addresses of IPv4-only nodes, which perforce do 1759 * not implement this protocol. 1760 * [icmp-name-lookups-07, Section 5.4] 1761 * So we don't support NI_NODEADDR_FLAG_COMPAT in 1762 * this function at this moment. 1763 */ 1764 1765 /* What do we have to do about ::1? */ 1766 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { 1767 case IPV6_ADDR_SCOPE_LINKLOCAL: 1768 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) 1769 continue; 1770 break; 1771 case IPV6_ADDR_SCOPE_SITELOCAL: 1772 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) 1773 continue; 1774 break; 1775 case IPV6_ADDR_SCOPE_GLOBAL: 1776 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) 1777 continue; 1778 break; 1779 default: 1780 continue; 1781 } 1782 1783 /* 1784 * check if anycast is okay. 1785 * XXX: just experimental. not in the spec. 1786 */ 1787 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && 1788 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) 1789 continue; /* we need only unicast addresses */ 1790 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && 1791 (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) { 1792 continue; 1793 } 1794 addrsofif++; /* count the address */ 1795 } 1796 IF_ADDR_RUNLOCK(ifp); 1797 if (iffound) { 1798 *ifpp = ifp; 1799 IFNET_RUNLOCK_NOSLEEP(); 1800 return (addrsofif); 1801 } 1802 1803 addrs += addrsofif; 1804 } 1805 IFNET_RUNLOCK_NOSLEEP(); 1806 1807 return (addrs); 1808 } 1809 1810 static int 1811 ni6_store_addrs(struct icmp6_nodeinfo *ni6, struct icmp6_nodeinfo *nni6, 1812 struct ifnet *ifp0, int resid) 1813 { 1814 struct ifnet *ifp; 1815 struct in6_ifaddr *ifa6; 1816 struct ifaddr *ifa; 1817 struct ifnet *ifp_dep = NULL; 1818 int copied = 0, allow_deprecated = 0; 1819 u_char *cp = (u_char *)(nni6 + 1); 1820 int niflags = ni6->ni_flags; 1821 u_int32_t ltime; 1822 1823 if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL)) 1824 return (0); /* needless to copy */ 1825 1826 IFNET_RLOCK_NOSLEEP(); 1827 ifp = ifp0 ? ifp0 : TAILQ_FIRST(&V_ifnet); 1828 again: 1829 1830 for (; ifp; ifp = TAILQ_NEXT(ifp, if_link)) { 1831 IF_ADDR_RLOCK(ifp); 1832 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 1833 if (ifa->ifa_addr->sa_family != AF_INET6) 1834 continue; 1835 ifa6 = (struct in6_ifaddr *)ifa; 1836 1837 if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 && 1838 allow_deprecated == 0) { 1839 /* 1840 * prefererred address should be put before 1841 * deprecated addresses. 1842 */ 1843 1844 /* record the interface for later search */ 1845 if (ifp_dep == NULL) 1846 ifp_dep = ifp; 1847 1848 continue; 1849 } else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 && 1850 allow_deprecated != 0) 1851 continue; /* we now collect deprecated addrs */ 1852 1853 /* What do we have to do about ::1? */ 1854 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { 1855 case IPV6_ADDR_SCOPE_LINKLOCAL: 1856 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) 1857 continue; 1858 break; 1859 case IPV6_ADDR_SCOPE_SITELOCAL: 1860 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) 1861 continue; 1862 break; 1863 case IPV6_ADDR_SCOPE_GLOBAL: 1864 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) 1865 continue; 1866 break; 1867 default: 1868 continue; 1869 } 1870 1871 /* 1872 * check if anycast is okay. 1873 * XXX: just experimental. not in the spec. 1874 */ 1875 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && 1876 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) 1877 continue; 1878 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && 1879 (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) { 1880 continue; 1881 } 1882 1883 /* now we can copy the address */ 1884 if (resid < sizeof(struct in6_addr) + 1885 sizeof(u_int32_t)) { 1886 IF_ADDR_RUNLOCK(ifp); 1887 /* 1888 * We give up much more copy. 1889 * Set the truncate flag and return. 1890 */ 1891 nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE; 1892 IFNET_RUNLOCK_NOSLEEP(); 1893 return (copied); 1894 } 1895 1896 /* 1897 * Set the TTL of the address. 1898 * The TTL value should be one of the following 1899 * according to the specification: 1900 * 1901 * 1. The remaining lifetime of a DHCP lease on the 1902 * address, or 1903 * 2. The remaining Valid Lifetime of a prefix from 1904 * which the address was derived through Stateless 1905 * Autoconfiguration. 1906 * 1907 * Note that we currently do not support stateful 1908 * address configuration by DHCPv6, so the former 1909 * case can't happen. 1910 */ 1911 if (ifa6->ia6_lifetime.ia6t_expire == 0) 1912 ltime = ND6_INFINITE_LIFETIME; 1913 else { 1914 if (ifa6->ia6_lifetime.ia6t_expire > 1915 time_uptime) 1916 ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_uptime); 1917 else 1918 ltime = 0; 1919 } 1920 1921 bcopy(<ime, cp, sizeof(u_int32_t)); 1922 cp += sizeof(u_int32_t); 1923 1924 /* copy the address itself */ 1925 bcopy(&ifa6->ia_addr.sin6_addr, cp, 1926 sizeof(struct in6_addr)); 1927 in6_clearscope((struct in6_addr *)cp); /* XXX */ 1928 cp += sizeof(struct in6_addr); 1929 1930 resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t)); 1931 copied += (sizeof(struct in6_addr) + sizeof(u_int32_t)); 1932 } 1933 IF_ADDR_RUNLOCK(ifp); 1934 if (ifp0) /* we need search only on the specified IF */ 1935 break; 1936 } 1937 1938 if (allow_deprecated == 0 && ifp_dep != NULL) { 1939 ifp = ifp_dep; 1940 allow_deprecated = 1; 1941 1942 goto again; 1943 } 1944 1945 IFNET_RUNLOCK_NOSLEEP(); 1946 1947 return (copied); 1948 } 1949 1950 /* 1951 * XXX almost dup'ed code with rip6_input. 1952 */ 1953 static int 1954 icmp6_rip6_input(struct mbuf **mp, int off) 1955 { 1956 struct mbuf *m = *mp; 1957 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1958 struct inpcb *in6p; 1959 struct inpcb *last = NULL; 1960 struct sockaddr_in6 fromsa; 1961 struct icmp6_hdr *icmp6; 1962 struct mbuf *opts = NULL; 1963 1964 #ifndef PULLDOWN_TEST 1965 /* this is assumed to be safe. */ 1966 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off); 1967 #else 1968 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6)); 1969 if (icmp6 == NULL) { 1970 /* m is already reclaimed */ 1971 return (IPPROTO_DONE); 1972 } 1973 #endif 1974 1975 /* 1976 * XXX: the address may have embedded scope zone ID, which should be 1977 * hidden from applications. 1978 */ 1979 bzero(&fromsa, sizeof(fromsa)); 1980 fromsa.sin6_family = AF_INET6; 1981 fromsa.sin6_len = sizeof(struct sockaddr_in6); 1982 fromsa.sin6_addr = ip6->ip6_src; 1983 if (sa6_recoverscope(&fromsa)) { 1984 m_freem(m); 1985 return (IPPROTO_DONE); 1986 } 1987 1988 INP_INFO_RLOCK(&V_ripcbinfo); 1989 LIST_FOREACH(in6p, &V_ripcb, inp_list) { 1990 if ((in6p->inp_vflag & INP_IPV6) == 0) 1991 continue; 1992 if (in6p->inp_ip_p != IPPROTO_ICMPV6) 1993 continue; 1994 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) && 1995 !IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &ip6->ip6_dst)) 1996 continue; 1997 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr) && 1998 !IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src)) 1999 continue; 2000 INP_RLOCK(in6p); 2001 if (ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type, 2002 in6p->in6p_icmp6filt)) { 2003 INP_RUNLOCK(in6p); 2004 continue; 2005 } 2006 if (last != NULL) { 2007 struct mbuf *n = NULL; 2008 2009 /* 2010 * Recent network drivers tend to allocate a single 2011 * mbuf cluster, rather than to make a couple of 2012 * mbufs without clusters. Also, since the IPv6 code 2013 * path tries to avoid m_pullup(), it is highly 2014 * probable that we still have an mbuf cluster here 2015 * even though the necessary length can be stored in an 2016 * mbuf's internal buffer. 2017 * Meanwhile, the default size of the receive socket 2018 * buffer for raw sockets is not so large. This means 2019 * the possibility of packet loss is relatively higher 2020 * than before. To avoid this scenario, we copy the 2021 * received data to a separate mbuf that does not use 2022 * a cluster, if possible. 2023 * XXX: it is better to copy the data after stripping 2024 * intermediate headers. 2025 */ 2026 if ((m->m_flags & M_EXT) && m->m_next == NULL && 2027 m->m_len <= MHLEN) { 2028 n = m_get(M_NOWAIT, m->m_type); 2029 if (n != NULL) { 2030 if (m_dup_pkthdr(n, m, M_NOWAIT)) { 2031 bcopy(m->m_data, n->m_data, 2032 m->m_len); 2033 n->m_len = m->m_len; 2034 } else { 2035 m_free(n); 2036 n = NULL; 2037 } 2038 } 2039 } 2040 if (n != NULL || 2041 (n = m_copy(m, 0, (int)M_COPYALL)) != NULL) { 2042 if (last->inp_flags & INP_CONTROLOPTS) 2043 ip6_savecontrol(last, n, &opts); 2044 /* strip intermediate headers */ 2045 m_adj(n, off); 2046 SOCKBUF_LOCK(&last->inp_socket->so_rcv); 2047 if (sbappendaddr_locked( 2048 &last->inp_socket->so_rcv, 2049 (struct sockaddr *)&fromsa, n, opts) 2050 == 0) { 2051 /* should notify about lost packet */ 2052 m_freem(n); 2053 if (opts) { 2054 m_freem(opts); 2055 } 2056 SOCKBUF_UNLOCK( 2057 &last->inp_socket->so_rcv); 2058 } else 2059 sorwakeup_locked(last->inp_socket); 2060 opts = NULL; 2061 } 2062 INP_RUNLOCK(last); 2063 } 2064 last = in6p; 2065 } 2066 INP_INFO_RUNLOCK(&V_ripcbinfo); 2067 if (last != NULL) { 2068 if (last->inp_flags & INP_CONTROLOPTS) 2069 ip6_savecontrol(last, m, &opts); 2070 /* strip intermediate headers */ 2071 m_adj(m, off); 2072 2073 /* avoid using mbuf clusters if possible (see above) */ 2074 if ((m->m_flags & M_EXT) && m->m_next == NULL && 2075 m->m_len <= MHLEN) { 2076 struct mbuf *n; 2077 2078 n = m_get(M_NOWAIT, m->m_type); 2079 if (n != NULL) { 2080 if (m_dup_pkthdr(n, m, M_NOWAIT)) { 2081 bcopy(m->m_data, n->m_data, m->m_len); 2082 n->m_len = m->m_len; 2083 2084 m_freem(m); 2085 m = n; 2086 } else { 2087 m_freem(n); 2088 n = NULL; 2089 } 2090 } 2091 } 2092 SOCKBUF_LOCK(&last->inp_socket->so_rcv); 2093 if (sbappendaddr_locked(&last->inp_socket->so_rcv, 2094 (struct sockaddr *)&fromsa, m, opts) == 0) { 2095 m_freem(m); 2096 if (opts) 2097 m_freem(opts); 2098 SOCKBUF_UNLOCK(&last->inp_socket->so_rcv); 2099 } else 2100 sorwakeup_locked(last->inp_socket); 2101 INP_RUNLOCK(last); 2102 } else { 2103 m_freem(m); 2104 IP6STAT_DEC(ip6s_delivered); 2105 } 2106 return IPPROTO_DONE; 2107 } 2108 2109 /* 2110 * Reflect the ip6 packet back to the source. 2111 * OFF points to the icmp6 header, counted from the top of the mbuf. 2112 */ 2113 void 2114 icmp6_reflect(struct mbuf *m, size_t off) 2115 { 2116 struct in6_addr src, *srcp = NULL; 2117 struct ip6_hdr *ip6; 2118 struct icmp6_hdr *icmp6; 2119 struct in6_ifaddr *ia = NULL; 2120 struct ifnet *outif = NULL; 2121 int plen; 2122 int type, code; 2123 2124 /* too short to reflect */ 2125 if (off < sizeof(struct ip6_hdr)) { 2126 nd6log((LOG_DEBUG, 2127 "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n", 2128 (u_long)off, (u_long)sizeof(struct ip6_hdr), 2129 __FILE__, __LINE__)); 2130 goto bad; 2131 } 2132 2133 /* 2134 * If there are extra headers between IPv6 and ICMPv6, strip 2135 * off that header first. 2136 */ 2137 #ifdef DIAGNOSTIC 2138 if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN) 2139 panic("assumption failed in icmp6_reflect"); 2140 #endif 2141 if (off > sizeof(struct ip6_hdr)) { 2142 size_t l; 2143 struct ip6_hdr nip6; 2144 2145 l = off - sizeof(struct ip6_hdr); 2146 m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6); 2147 m_adj(m, l); 2148 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 2149 if (m->m_len < l) { 2150 if ((m = m_pullup(m, l)) == NULL) 2151 return; 2152 } 2153 bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6)); 2154 } else /* off == sizeof(struct ip6_hdr) */ { 2155 size_t l; 2156 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 2157 if (m->m_len < l) { 2158 if ((m = m_pullup(m, l)) == NULL) 2159 return; 2160 } 2161 } 2162 plen = m->m_pkthdr.len - sizeof(struct ip6_hdr); 2163 ip6 = mtod(m, struct ip6_hdr *); 2164 ip6->ip6_nxt = IPPROTO_ICMPV6; 2165 icmp6 = (struct icmp6_hdr *)(ip6 + 1); 2166 type = icmp6->icmp6_type; /* keep type for statistics */ 2167 code = icmp6->icmp6_code; /* ditto. */ 2168 2169 /* 2170 * If the incoming packet was addressed directly to us (i.e. unicast), 2171 * use dst as the src for the reply. 2172 * The IN6_IFF_NOTREADY case should be VERY rare, but is possible 2173 * (for example) when we encounter an error while forwarding procedure 2174 * destined to a duplicated address of ours. 2175 */ 2176 if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 2177 ia = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */); 2178 if (ia != NULL && !(ia->ia6_flags & 2179 (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) 2180 srcp = &ia->ia_addr.sin6_addr; 2181 } 2182 2183 if (srcp == NULL) { 2184 int e; 2185 struct sockaddr_in6 sin6; 2186 struct route_in6 ro; 2187 2188 /* 2189 * This case matches to multicasts, our anycast, or unicasts 2190 * that we do not own. Select a source address based on the 2191 * source address of the erroneous packet. 2192 */ 2193 bzero(&sin6, sizeof(sin6)); 2194 sin6.sin6_family = AF_INET6; 2195 sin6.sin6_len = sizeof(sin6); 2196 sin6.sin6_addr = ip6->ip6_dst; /* zone ID should be embedded */ 2197 2198 bzero(&ro, sizeof(ro)); 2199 e = in6_selectsrc(&sin6, NULL, NULL, &ro, NULL, &outif, &src); 2200 if (ro.ro_rt) 2201 RTFREE(ro.ro_rt); /* XXX: we could use this */ 2202 if (e) { 2203 char ip6buf[INET6_ADDRSTRLEN]; 2204 nd6log((LOG_DEBUG, 2205 "icmp6_reflect: source can't be determined: " 2206 "dst=%s, error=%d\n", 2207 ip6_sprintf(ip6buf, &sin6.sin6_addr), e)); 2208 goto bad; 2209 } 2210 srcp = &src; 2211 } 2212 /* 2213 * ip6_input() drops a packet if its src is multicast. 2214 * So, the src is never multicast. 2215 */ 2216 ip6->ip6_dst = ip6->ip6_src; 2217 ip6->ip6_src = *srcp; 2218 ip6->ip6_flow = 0; 2219 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2220 ip6->ip6_vfc |= IPV6_VERSION; 2221 ip6->ip6_nxt = IPPROTO_ICMPV6; 2222 if (outif) 2223 ip6->ip6_hlim = ND_IFINFO(outif)->chlim; 2224 else if (m->m_pkthdr.rcvif) { 2225 /* XXX: This may not be the outgoing interface */ 2226 ip6->ip6_hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim; 2227 } else 2228 ip6->ip6_hlim = V_ip6_defhlim; 2229 2230 icmp6->icmp6_cksum = 0; 2231 icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2232 sizeof(struct ip6_hdr), plen); 2233 2234 /* 2235 * XXX option handling 2236 */ 2237 2238 m->m_flags &= ~(M_BCAST|M_MCAST); 2239 2240 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2241 if (outif) 2242 icmp6_ifoutstat_inc(outif, type, code); 2243 2244 if (ia != NULL) 2245 ifa_free(&ia->ia_ifa); 2246 return; 2247 2248 bad: 2249 if (ia != NULL) 2250 ifa_free(&ia->ia_ifa); 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 struct rtentry *rt = NULL; 2293 int is_router; 2294 int is_onlink; 2295 struct in6_addr src6 = ip6->ip6_src; 2296 struct in6_addr redtgt6; 2297 struct in6_addr reddst6; 2298 union nd_opts ndopts; 2299 char ip6buf[INET6_ADDRSTRLEN]; 2300 2301 M_ASSERTPKTHDR(m); 2302 KASSERT(m->m_pkthdr.rcvif != NULL, ("%s: no rcvif", __func__)); 2303 2304 ifp = m->m_pkthdr.rcvif; 2305 2306 /* XXX if we are router, we don't update route by icmp6 redirect */ 2307 if (V_ip6_forwarding) 2308 goto freeit; 2309 if (!V_icmp6_rediraccept) 2310 goto freeit; 2311 2312 #ifndef PULLDOWN_TEST 2313 IP6_EXTHDR_CHECK(m, off, icmp6len,); 2314 nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off); 2315 #else 2316 IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len); 2317 if (nd_rd == NULL) { 2318 ICMP6STAT_INC(icp6s_tooshort); 2319 return; 2320 } 2321 #endif 2322 redtgt6 = nd_rd->nd_rd_target; 2323 reddst6 = nd_rd->nd_rd_dst; 2324 2325 if (in6_setscope(&redtgt6, m->m_pkthdr.rcvif, NULL) || 2326 in6_setscope(&reddst6, m->m_pkthdr.rcvif, NULL)) { 2327 goto freeit; 2328 } 2329 2330 /* validation */ 2331 if (!IN6_IS_ADDR_LINKLOCAL(&src6)) { 2332 nd6log((LOG_ERR, 2333 "ICMP6 redirect sent from %s rejected; " 2334 "must be from linklocal\n", 2335 ip6_sprintf(ip6buf, &src6))); 2336 goto bad; 2337 } 2338 if (ip6->ip6_hlim != 255) { 2339 nd6log((LOG_ERR, 2340 "ICMP6 redirect sent from %s rejected; " 2341 "hlim=%d (must be 255)\n", 2342 ip6_sprintf(ip6buf, &src6), ip6->ip6_hlim)); 2343 goto bad; 2344 } 2345 { 2346 /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */ 2347 struct sockaddr_in6 sin6; 2348 struct in6_addr *gw6; 2349 2350 bzero(&sin6, sizeof(sin6)); 2351 sin6.sin6_family = AF_INET6; 2352 sin6.sin6_len = sizeof(struct sockaddr_in6); 2353 bcopy(&reddst6, &sin6.sin6_addr, sizeof(reddst6)); 2354 rt = in6_rtalloc1((struct sockaddr *)&sin6, 0, 0UL, RT_DEFAULT_FIB); 2355 if (rt) { 2356 if (rt->rt_gateway == NULL || 2357 rt->rt_gateway->sa_family != AF_INET6) { 2358 RTFREE_LOCKED(rt); 2359 nd6log((LOG_ERR, 2360 "ICMP6 redirect rejected; no route " 2361 "with inet6 gateway found for redirect dst: %s\n", 2362 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2363 goto bad; 2364 } 2365 2366 gw6 = &(((struct sockaddr_in6 *)rt->rt_gateway)->sin6_addr); 2367 if (bcmp(&src6, gw6, sizeof(struct in6_addr)) != 0) { 2368 RTFREE_LOCKED(rt); 2369 nd6log((LOG_ERR, 2370 "ICMP6 redirect rejected; " 2371 "not equal to gw-for-src=%s (must be same): " 2372 "%s\n", 2373 ip6_sprintf(ip6buf, gw6), 2374 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2375 goto bad; 2376 } 2377 } else { 2378 nd6log((LOG_ERR, 2379 "ICMP6 redirect rejected; " 2380 "no route found for redirect dst: %s\n", 2381 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2382 goto bad; 2383 } 2384 RTFREE_LOCKED(rt); 2385 rt = NULL; 2386 } 2387 if (IN6_IS_ADDR_MULTICAST(&reddst6)) { 2388 nd6log((LOG_ERR, 2389 "ICMP6 redirect rejected; " 2390 "redirect dst must be unicast: %s\n", 2391 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2392 goto bad; 2393 } 2394 2395 is_router = is_onlink = 0; 2396 if (IN6_IS_ADDR_LINKLOCAL(&redtgt6)) 2397 is_router = 1; /* router case */ 2398 if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0) 2399 is_onlink = 1; /* on-link destination case */ 2400 if (!is_router && !is_onlink) { 2401 nd6log((LOG_ERR, 2402 "ICMP6 redirect rejected; " 2403 "neither router case nor onlink case: %s\n", 2404 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2405 goto bad; 2406 } 2407 2408 icmp6len -= sizeof(*nd_rd); 2409 nd6_option_init(nd_rd + 1, icmp6len, &ndopts); 2410 if (nd6_options(&ndopts) < 0) { 2411 nd6log((LOG_INFO, "%s: invalid ND option, rejected: %s\n", 2412 __func__, icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2413 /* nd6_options have incremented stats */ 2414 goto freeit; 2415 } 2416 2417 if (ndopts.nd_opts_tgt_lladdr) { 2418 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 2419 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 2420 } 2421 2422 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 2423 nd6log((LOG_INFO, "%s: lladdrlen mismatch for %s " 2424 "(if %d, icmp6 packet %d): %s\n", 2425 __func__, ip6_sprintf(ip6buf, &redtgt6), 2426 ifp->if_addrlen, lladdrlen - 2, 2427 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2428 goto bad; 2429 } 2430 2431 /* Validation passed. */ 2432 2433 /* RFC 2461 8.3 */ 2434 nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT, 2435 is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER); 2436 2437 /* 2438 * Install a gateway route in the better-router case or an interface 2439 * route in the on-link-destination case. 2440 */ 2441 { 2442 struct sockaddr_in6 sdst; 2443 struct sockaddr_in6 sgw; 2444 struct sockaddr_in6 ssrc; 2445 struct sockaddr *gw; 2446 int rt_flags; 2447 u_int fibnum; 2448 2449 bzero(&sdst, sizeof(sdst)); 2450 bzero(&ssrc, sizeof(ssrc)); 2451 sdst.sin6_family = ssrc.sin6_family = AF_INET6; 2452 sdst.sin6_len = ssrc.sin6_len = sizeof(struct sockaddr_in6); 2453 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr)); 2454 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr)); 2455 rt_flags = RTF_HOST; 2456 if (is_router) { 2457 bzero(&sgw, sizeof(sgw)); 2458 sgw.sin6_family = AF_INET6; 2459 sgw.sin6_len = sizeof(struct sockaddr_in6); 2460 bcopy(&redtgt6, &sgw.sin6_addr, 2461 sizeof(struct in6_addr)); 2462 gw = (struct sockaddr *)&sgw; 2463 rt_flags |= RTF_GATEWAY; 2464 } else 2465 gw = ifp->if_addr->ifa_addr; 2466 for (fibnum = 0; fibnum < rt_numfibs; fibnum++) 2467 in6_rtredirect((struct sockaddr *)&sdst, gw, 2468 (struct sockaddr *)NULL, rt_flags, 2469 (struct sockaddr *)&ssrc, fibnum); 2470 } 2471 /* finally update cached route in each socket via pfctlinput */ 2472 { 2473 struct sockaddr_in6 sdst; 2474 2475 bzero(&sdst, sizeof(sdst)); 2476 sdst.sin6_family = AF_INET6; 2477 sdst.sin6_len = sizeof(struct sockaddr_in6); 2478 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr)); 2479 pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst); 2480 } 2481 2482 freeit: 2483 m_freem(m); 2484 return; 2485 2486 bad: 2487 ICMP6STAT_INC(icp6s_badredirect); 2488 m_freem(m); 2489 } 2490 2491 void 2492 icmp6_redirect_output(struct mbuf *m0, struct rtentry *rt) 2493 { 2494 struct ifnet *ifp; /* my outgoing interface */ 2495 struct in6_addr *ifp_ll6; 2496 struct in6_addr *router_ll6; 2497 struct ip6_hdr *sip6; /* m0 as struct ip6_hdr */ 2498 struct mbuf *m = NULL; /* newly allocated one */ 2499 struct m_tag *mtag; 2500 struct ip6_hdr *ip6; /* m as struct ip6_hdr */ 2501 struct nd_redirect *nd_rd; 2502 struct llentry *ln = NULL; 2503 size_t maxlen; 2504 u_char *p; 2505 struct ifnet *outif = NULL; 2506 struct sockaddr_in6 src_sa; 2507 2508 icmp6_errcount(ND_REDIRECT, 0); 2509 2510 /* if we are not router, we don't send icmp6 redirect */ 2511 if (!V_ip6_forwarding) 2512 goto fail; 2513 2514 /* sanity check */ 2515 if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp)) 2516 goto fail; 2517 2518 /* 2519 * Address check: 2520 * the source address must identify a neighbor, and 2521 * the destination address must not be a multicast address 2522 * [RFC 2461, sec 8.2] 2523 */ 2524 sip6 = mtod(m0, struct ip6_hdr *); 2525 bzero(&src_sa, sizeof(src_sa)); 2526 src_sa.sin6_family = AF_INET6; 2527 src_sa.sin6_len = sizeof(src_sa); 2528 src_sa.sin6_addr = sip6->ip6_src; 2529 if (nd6_is_addr_neighbor(&src_sa, ifp) == 0) 2530 goto fail; 2531 if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst)) 2532 goto fail; /* what should we do here? */ 2533 2534 /* rate limit */ 2535 if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0)) 2536 goto fail; 2537 2538 /* 2539 * Since we are going to append up to 1280 bytes (= IPV6_MMTU), 2540 * we almost always ask for an mbuf cluster for simplicity. 2541 * (MHLEN < IPV6_MMTU is almost always true) 2542 */ 2543 #if IPV6_MMTU >= MCLBYTES 2544 # error assumption failed about IPV6_MMTU and MCLBYTES 2545 #endif 2546 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 2547 if (m == NULL) 2548 goto fail; 2549 M_SETFIB(m, rt->rt_fibnum); 2550 maxlen = M_TRAILINGSPACE(m); 2551 maxlen = min(IPV6_MMTU, maxlen); 2552 /* just for safety */ 2553 if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) + 2554 ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) { 2555 goto fail; 2556 } 2557 2558 { 2559 /* get ip6 linklocal address for ifp(my outgoing interface). */ 2560 struct in6_ifaddr *ia; 2561 if ((ia = in6ifa_ifpforlinklocal(ifp, 2562 IN6_IFF_NOTREADY| 2563 IN6_IFF_ANYCAST)) == NULL) 2564 goto fail; 2565 ifp_ll6 = &ia->ia_addr.sin6_addr; 2566 /* XXXRW: reference released prematurely. */ 2567 ifa_free(&ia->ia_ifa); 2568 } 2569 2570 /* get ip6 linklocal address for the router. */ 2571 if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) { 2572 struct sockaddr_in6 *sin6; 2573 sin6 = (struct sockaddr_in6 *)rt->rt_gateway; 2574 router_ll6 = &sin6->sin6_addr; 2575 if (!IN6_IS_ADDR_LINKLOCAL(router_ll6)) 2576 router_ll6 = (struct in6_addr *)NULL; 2577 } else 2578 router_ll6 = (struct in6_addr *)NULL; 2579 2580 /* ip6 */ 2581 ip6 = mtod(m, struct ip6_hdr *); 2582 ip6->ip6_flow = 0; 2583 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2584 ip6->ip6_vfc |= IPV6_VERSION; 2585 /* ip6->ip6_plen will be set later */ 2586 ip6->ip6_nxt = IPPROTO_ICMPV6; 2587 ip6->ip6_hlim = 255; 2588 /* ip6->ip6_src must be linklocal addr for my outgoing if. */ 2589 bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr)); 2590 bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr)); 2591 2592 /* ND Redirect */ 2593 nd_rd = (struct nd_redirect *)(ip6 + 1); 2594 nd_rd->nd_rd_type = ND_REDIRECT; 2595 nd_rd->nd_rd_code = 0; 2596 nd_rd->nd_rd_reserved = 0; 2597 if (rt->rt_flags & RTF_GATEWAY) { 2598 /* 2599 * nd_rd->nd_rd_target must be a link-local address in 2600 * better router cases. 2601 */ 2602 if (!router_ll6) 2603 goto fail; 2604 bcopy(router_ll6, &nd_rd->nd_rd_target, 2605 sizeof(nd_rd->nd_rd_target)); 2606 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2607 sizeof(nd_rd->nd_rd_dst)); 2608 } else { 2609 /* make sure redtgt == reddst */ 2610 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target, 2611 sizeof(nd_rd->nd_rd_target)); 2612 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2613 sizeof(nd_rd->nd_rd_dst)); 2614 } 2615 2616 p = (u_char *)(nd_rd + 1); 2617 2618 if (!router_ll6) 2619 goto nolladdropt; 2620 2621 { 2622 /* target lladdr option */ 2623 int len; 2624 struct nd_opt_hdr *nd_opt; 2625 char *lladdr; 2626 2627 IF_AFDATA_RLOCK(ifp); 2628 ln = nd6_lookup(router_ll6, 0, ifp); 2629 IF_AFDATA_RUNLOCK(ifp); 2630 if (ln == NULL) 2631 goto nolladdropt; 2632 2633 len = sizeof(*nd_opt) + ifp->if_addrlen; 2634 len = (len + 7) & ~7; /* round by 8 */ 2635 /* safety check */ 2636 if (len + (p - (u_char *)ip6) > maxlen) 2637 goto nolladdropt; 2638 2639 if (ln->la_flags & LLE_VALID) { 2640 nd_opt = (struct nd_opt_hdr *)p; 2641 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 2642 nd_opt->nd_opt_len = len >> 3; 2643 lladdr = (char *)(nd_opt + 1); 2644 bcopy(&ln->ll_addr, lladdr, ifp->if_addrlen); 2645 p += len; 2646 } 2647 } 2648 nolladdropt: 2649 if (ln != NULL) 2650 LLE_RUNLOCK(ln); 2651 2652 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2653 2654 /* just to be safe */ 2655 #ifdef M_DECRYPTED /*not openbsd*/ 2656 if (m0->m_flags & M_DECRYPTED) 2657 goto noredhdropt; 2658 #endif 2659 if (p - (u_char *)ip6 > maxlen) 2660 goto noredhdropt; 2661 2662 { 2663 /* redirected header option */ 2664 int len; 2665 struct nd_opt_rd_hdr *nd_opt_rh; 2666 2667 /* 2668 * compute the maximum size for icmp6 redirect header option. 2669 * XXX room for auth header? 2670 */ 2671 len = maxlen - (p - (u_char *)ip6); 2672 len &= ~7; 2673 2674 /* This is just for simplicity. */ 2675 if (m0->m_pkthdr.len != m0->m_len) { 2676 if (m0->m_next) { 2677 m_freem(m0->m_next); 2678 m0->m_next = NULL; 2679 } 2680 m0->m_pkthdr.len = m0->m_len; 2681 } 2682 2683 /* 2684 * Redirected header option spec (RFC2461 4.6.3) talks nothing 2685 * about padding/truncate rule for the original IP packet. 2686 * From the discussion on IPv6imp in Feb 1999, 2687 * the consensus was: 2688 * - "attach as much as possible" is the goal 2689 * - pad if not aligned (original size can be guessed by 2690 * original ip6 header) 2691 * Following code adds the padding if it is simple enough, 2692 * and truncates if not. 2693 */ 2694 if (m0->m_next || m0->m_pkthdr.len != m0->m_len) 2695 panic("assumption failed in %s:%d", __FILE__, 2696 __LINE__); 2697 2698 if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) { 2699 /* not enough room, truncate */ 2700 m0->m_pkthdr.len = m0->m_len = len - 2701 sizeof(*nd_opt_rh); 2702 } else { 2703 /* enough room, pad or truncate */ 2704 size_t extra; 2705 2706 extra = m0->m_pkthdr.len % 8; 2707 if (extra) { 2708 /* pad if easy enough, truncate if not */ 2709 if (8 - extra <= M_TRAILINGSPACE(m0)) { 2710 /* pad */ 2711 m0->m_len += (8 - extra); 2712 m0->m_pkthdr.len += (8 - extra); 2713 } else { 2714 /* truncate */ 2715 m0->m_pkthdr.len -= extra; 2716 m0->m_len -= extra; 2717 } 2718 } 2719 len = m0->m_pkthdr.len + sizeof(*nd_opt_rh); 2720 m0->m_pkthdr.len = m0->m_len = len - 2721 sizeof(*nd_opt_rh); 2722 } 2723 2724 nd_opt_rh = (struct nd_opt_rd_hdr *)p; 2725 bzero(nd_opt_rh, sizeof(*nd_opt_rh)); 2726 nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER; 2727 nd_opt_rh->nd_opt_rh_len = len >> 3; 2728 p += sizeof(*nd_opt_rh); 2729 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2730 2731 /* connect m0 to m */ 2732 m_tag_delete_chain(m0, NULL); 2733 m0->m_flags &= ~M_PKTHDR; 2734 m->m_next = m0; 2735 m->m_pkthdr.len = m->m_len + m0->m_len; 2736 m0 = NULL; 2737 } 2738 noredhdropt:; 2739 if (m0) { 2740 m_freem(m0); 2741 m0 = NULL; 2742 } 2743 2744 /* XXX: clear embedded link IDs in the inner header */ 2745 in6_clearscope(&sip6->ip6_src); 2746 in6_clearscope(&sip6->ip6_dst); 2747 in6_clearscope(&nd_rd->nd_rd_target); 2748 in6_clearscope(&nd_rd->nd_rd_dst); 2749 2750 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr)); 2751 2752 nd_rd->nd_rd_cksum = 0; 2753 nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2754 sizeof(*ip6), ntohs(ip6->ip6_plen)); 2755 2756 if (send_sendso_input_hook != NULL) { 2757 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, sizeof(unsigned short), 2758 M_NOWAIT); 2759 if (mtag == NULL) 2760 goto fail; 2761 *(unsigned short *)(mtag + 1) = nd_rd->nd_rd_type; 2762 m_tag_prepend(m, mtag); 2763 } 2764 2765 /* send the packet to outside... */ 2766 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2767 if (outif) { 2768 icmp6_ifstat_inc(outif, ifs6_out_msg); 2769 icmp6_ifstat_inc(outif, ifs6_out_redirect); 2770 } 2771 ICMP6STAT_INC(icp6s_outhist[ND_REDIRECT]); 2772 2773 return; 2774 2775 fail: 2776 if (m) 2777 m_freem(m); 2778 if (m0) 2779 m_freem(m0); 2780 } 2781 2782 /* 2783 * ICMPv6 socket option processing. 2784 */ 2785 int 2786 icmp6_ctloutput(struct socket *so, struct sockopt *sopt) 2787 { 2788 int error = 0; 2789 int optlen; 2790 struct inpcb *inp = sotoinpcb(so); 2791 int level, op, optname; 2792 2793 if (sopt) { 2794 level = sopt->sopt_level; 2795 op = sopt->sopt_dir; 2796 optname = sopt->sopt_name; 2797 optlen = sopt->sopt_valsize; 2798 } else 2799 level = op = optname = optlen = 0; 2800 2801 if (level != IPPROTO_ICMPV6) { 2802 return EINVAL; 2803 } 2804 2805 switch (op) { 2806 case PRCO_SETOPT: 2807 switch (optname) { 2808 case ICMP6_FILTER: 2809 { 2810 struct icmp6_filter ic6f; 2811 2812 if (optlen != sizeof(ic6f)) { 2813 error = EMSGSIZE; 2814 break; 2815 } 2816 error = sooptcopyin(sopt, &ic6f, optlen, optlen); 2817 if (error == 0) { 2818 INP_WLOCK(inp); 2819 *inp->in6p_icmp6filt = ic6f; 2820 INP_WUNLOCK(inp); 2821 } 2822 break; 2823 } 2824 2825 default: 2826 error = ENOPROTOOPT; 2827 break; 2828 } 2829 break; 2830 2831 case PRCO_GETOPT: 2832 switch (optname) { 2833 case ICMP6_FILTER: 2834 { 2835 struct icmp6_filter ic6f; 2836 2837 INP_RLOCK(inp); 2838 ic6f = *inp->in6p_icmp6filt; 2839 INP_RUNLOCK(inp); 2840 error = sooptcopyout(sopt, &ic6f, sizeof(ic6f)); 2841 break; 2842 } 2843 2844 default: 2845 error = ENOPROTOOPT; 2846 break; 2847 } 2848 break; 2849 } 2850 2851 return (error); 2852 } 2853 2854 /* 2855 * Perform rate limit check. 2856 * Returns 0 if it is okay to send the icmp6 packet. 2857 * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate 2858 * limitation. 2859 * 2860 * XXX per-destination/type check necessary? 2861 * 2862 * dst - not used at this moment 2863 * type - not used at this moment 2864 * code - not used at this moment 2865 */ 2866 static int 2867 icmp6_ratelimit(const struct in6_addr *dst, const int type, 2868 const int code) 2869 { 2870 int ret; 2871 2872 ret = 0; /* okay to send */ 2873 2874 /* PPS limit */ 2875 if (!ppsratecheck(&V_icmp6errppslim_last, &V_icmp6errpps_count, 2876 V_icmp6errppslim)) { 2877 /* The packet is subject to rate limit */ 2878 ret++; 2879 } 2880 2881 return ret; 2882 } 2883