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_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 & 5) != 5) 671 break; 672 673 if (code != 0) 674 goto badcode; 675 676 CTASSERT(sizeof(*nip6) + sizeof(*nicmp6) + 4 <= MHLEN); 677 n = m_gethdr(M_NOWAIT, m->m_type); 678 if (n == NULL) { 679 /* Give up remote */ 680 break; 681 } 682 if (!m_dup_pkthdr(n, m, M_NOWAIT)) { 683 /* 684 * Previous code did a blind M_COPY_PKTHDR 685 * and said "just for rcvif". If true, then 686 * we could tolerate the dup failing (due to 687 * the deep copy of the tag chain). For now 688 * be conservative and just fail. 689 */ 690 m_free(n); 691 n = NULL; 692 } 693 maxhlen = M_TRAILINGSPACE(n) - 694 (sizeof(*nip6) + sizeof(*nicmp6) + 4); 695 pr = curthread->td_ucred->cr_prison; 696 mtx_lock(&pr->pr_mtx); 697 hlen = strlen(pr->pr_hostname); 698 if (maxhlen > hlen) 699 maxhlen = hlen; 700 /* 701 * Copy IPv6 and ICMPv6 only. 702 */ 703 nip6 = mtod(n, struct ip6_hdr *); 704 bcopy(ip6, nip6, sizeof(struct ip6_hdr)); 705 nicmp6 = (struct icmp6_hdr *)(nip6 + 1); 706 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr)); 707 p = (u_char *)(nicmp6 + 1); 708 bzero(p, 4); 709 /* meaningless TTL */ 710 bcopy(pr->pr_hostname, p + 4, maxhlen); 711 mtx_unlock(&pr->pr_mtx); 712 noff = sizeof(struct ip6_hdr); 713 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + 714 sizeof(struct icmp6_hdr) + 4 + maxhlen; 715 nicmp6->icmp6_type = ICMP6_WRUREPLY; 716 nicmp6->icmp6_code = 0; 717 } 718 if (n) { 719 ICMP6STAT_INC(icp6s_reflect); 720 ICMP6STAT_INC(icp6s_outhist[ICMP6_WRUREPLY]); 721 icmp6_reflect(n, noff); 722 } 723 break; 724 } 725 726 case ICMP6_WRUREPLY: 727 if (code != 0) 728 goto badcode; 729 break; 730 731 case ND_ROUTER_SOLICIT: 732 icmp6_ifstat_inc(ifp, ifs6_in_routersolicit); 733 if (code != 0) 734 goto badcode; 735 if (icmp6len < sizeof(struct nd_router_solicit)) 736 goto badlen; 737 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) { 738 /* give up local */ 739 740 /* Send incoming SeND packet to user space. */ 741 if (send_sendso_input_hook != NULL) { 742 IP6_EXTHDR_CHECK(m, off, 743 icmp6len, IPPROTO_DONE); 744 error = send_sendso_input_hook(m, ifp, 745 SND_IN, ip6len); 746 /* -1 == no app on SEND socket */ 747 if (error == 0) 748 return (IPPROTO_DONE); 749 nd6_rs_input(m, off, icmp6len); 750 } else 751 nd6_rs_input(m, off, icmp6len); 752 m = NULL; 753 goto freeit; 754 } 755 if (send_sendso_input_hook != NULL) { 756 IP6_EXTHDR_CHECK(n, off, 757 icmp6len, IPPROTO_DONE); 758 error = send_sendso_input_hook(n, ifp, 759 SND_IN, ip6len); 760 if (error == 0) 761 goto freeit; 762 /* -1 == no app on SEND socket */ 763 nd6_rs_input(n, off, icmp6len); 764 } else 765 nd6_rs_input(n, off, icmp6len); 766 /* m stays. */ 767 break; 768 769 case ND_ROUTER_ADVERT: 770 icmp6_ifstat_inc(ifp, ifs6_in_routeradvert); 771 if (code != 0) 772 goto badcode; 773 if (icmp6len < sizeof(struct nd_router_advert)) 774 goto badlen; 775 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) { 776 777 /* Send incoming SeND-protected/ND packet to user space. */ 778 if (send_sendso_input_hook != NULL) { 779 error = send_sendso_input_hook(m, ifp, 780 SND_IN, ip6len); 781 if (error == 0) 782 return (IPPROTO_DONE); 783 nd6_ra_input(m, off, icmp6len); 784 } else 785 nd6_ra_input(m, off, icmp6len); 786 m = NULL; 787 goto freeit; 788 } 789 if (send_sendso_input_hook != NULL) { 790 error = send_sendso_input_hook(n, ifp, 791 SND_IN, ip6len); 792 if (error == 0) 793 goto freeit; 794 nd6_ra_input(n, off, icmp6len); 795 } else 796 nd6_ra_input(n, off, icmp6len); 797 /* m stays. */ 798 break; 799 800 case ND_NEIGHBOR_SOLICIT: 801 icmp6_ifstat_inc(ifp, ifs6_in_neighborsolicit); 802 if (code != 0) 803 goto badcode; 804 if (icmp6len < sizeof(struct nd_neighbor_solicit)) 805 goto badlen; 806 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) { 807 if (send_sendso_input_hook != NULL) { 808 error = send_sendso_input_hook(m, ifp, 809 SND_IN, ip6len); 810 if (error == 0) 811 return (IPPROTO_DONE); 812 nd6_ns_input(m, off, icmp6len); 813 } else 814 nd6_ns_input(m, off, icmp6len); 815 m = NULL; 816 goto freeit; 817 } 818 if (send_sendso_input_hook != NULL) { 819 error = send_sendso_input_hook(n, ifp, 820 SND_IN, ip6len); 821 if (error == 0) 822 goto freeit; 823 nd6_ns_input(n, off, icmp6len); 824 } else 825 nd6_ns_input(n, off, icmp6len); 826 /* m stays. */ 827 break; 828 829 case ND_NEIGHBOR_ADVERT: 830 icmp6_ifstat_inc(ifp, ifs6_in_neighboradvert); 831 if (code != 0) 832 goto badcode; 833 if (icmp6len < sizeof(struct nd_neighbor_advert)) 834 goto badlen; 835 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) { 836 837 /* Send incoming SeND-protected/ND packet to user space. */ 838 if (send_sendso_input_hook != NULL) { 839 error = send_sendso_input_hook(m, ifp, 840 SND_IN, ip6len); 841 if (error == 0) 842 return (IPPROTO_DONE); 843 nd6_na_input(m, off, icmp6len); 844 } else 845 nd6_na_input(m, off, icmp6len); 846 m = NULL; 847 goto freeit; 848 } 849 if (send_sendso_input_hook != NULL) { 850 error = send_sendso_input_hook(n, ifp, 851 SND_IN, ip6len); 852 if (error == 0) 853 goto freeit; 854 nd6_na_input(n, off, icmp6len); 855 } else 856 nd6_na_input(n, off, icmp6len); 857 /* m stays. */ 858 break; 859 860 case ND_REDIRECT: 861 icmp6_ifstat_inc(ifp, ifs6_in_redirect); 862 if (code != 0) 863 goto badcode; 864 if (icmp6len < sizeof(struct nd_redirect)) 865 goto badlen; 866 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) { 867 if (send_sendso_input_hook != NULL) { 868 error = send_sendso_input_hook(m, ifp, 869 SND_IN, ip6len); 870 if (error == 0) 871 return (IPPROTO_DONE); 872 icmp6_redirect_input(m, off); 873 } else 874 icmp6_redirect_input(m, off); 875 m = NULL; 876 goto freeit; 877 } 878 if (send_sendso_input_hook != NULL) { 879 error = send_sendso_input_hook(n, ifp, 880 SND_IN, ip6len); 881 if (error == 0) 882 goto freeit; 883 icmp6_redirect_input(n, off); 884 } else 885 icmp6_redirect_input(n, off); 886 /* m stays. */ 887 break; 888 889 case ICMP6_ROUTER_RENUMBERING: 890 if (code != ICMP6_ROUTER_RENUMBERING_COMMAND && 891 code != ICMP6_ROUTER_RENUMBERING_RESULT) 892 goto badcode; 893 if (icmp6len < sizeof(struct icmp6_router_renum)) 894 goto badlen; 895 break; 896 897 default: 898 nd6log((LOG_DEBUG, 899 "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n", 900 icmp6->icmp6_type, ip6_sprintf(ip6bufs, &ip6->ip6_src), 901 ip6_sprintf(ip6bufd, &ip6->ip6_dst), 902 ifp ? ifp->if_index : 0)); 903 if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) { 904 /* ICMPv6 error: MUST deliver it by spec... */ 905 code = PRC_NCMDS; 906 /* deliver */ 907 } else { 908 /* ICMPv6 informational: MUST not deliver */ 909 break; 910 } 911 deliver: 912 if (icmp6_notify_error(&m, off, icmp6len, code) != 0) { 913 /* In this case, m should've been freed. */ 914 return (IPPROTO_DONE); 915 } 916 break; 917 918 badcode: 919 ICMP6STAT_INC(icp6s_badcode); 920 break; 921 922 badlen: 923 ICMP6STAT_INC(icp6s_badlen); 924 break; 925 } 926 927 /* deliver the packet to appropriate sockets */ 928 icmp6_rip6_input(&m, *offp); 929 930 return IPPROTO_DONE; 931 932 freeit: 933 m_freem(m); 934 return IPPROTO_DONE; 935 } 936 937 static int 938 icmp6_notify_error(struct mbuf **mp, int off, int icmp6len, int code) 939 { 940 struct mbuf *m = *mp; 941 struct icmp6_hdr *icmp6; 942 struct ip6_hdr *eip6; 943 u_int32_t notifymtu; 944 struct sockaddr_in6 icmp6src, icmp6dst; 945 946 if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) { 947 ICMP6STAT_INC(icp6s_tooshort); 948 goto freeit; 949 } 950 #ifndef PULLDOWN_TEST 951 IP6_EXTHDR_CHECK(m, off, 952 sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr), -1); 953 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 954 #else 955 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, 956 sizeof(*icmp6) + sizeof(struct ip6_hdr)); 957 if (icmp6 == NULL) { 958 ICMP6STAT_INC(icp6s_tooshort); 959 return (-1); 960 } 961 #endif 962 eip6 = (struct ip6_hdr *)(icmp6 + 1); 963 964 /* Detect the upper level protocol */ 965 { 966 void (*ctlfunc)(int, struct sockaddr *, void *); 967 u_int8_t nxt = eip6->ip6_nxt; 968 int eoff = off + sizeof(struct icmp6_hdr) + 969 sizeof(struct ip6_hdr); 970 struct ip6ctlparam ip6cp; 971 struct in6_addr *finaldst = NULL; 972 int icmp6type = icmp6->icmp6_type; 973 struct ip6_frag *fh; 974 struct ip6_rthdr *rth; 975 struct ip6_rthdr0 *rth0; 976 int rthlen; 977 978 while (1) { /* XXX: should avoid infinite loop explicitly? */ 979 struct ip6_ext *eh; 980 981 switch (nxt) { 982 case IPPROTO_HOPOPTS: 983 case IPPROTO_DSTOPTS: 984 case IPPROTO_AH: 985 #ifndef PULLDOWN_TEST 986 IP6_EXTHDR_CHECK(m, 0, 987 eoff + sizeof(struct ip6_ext), -1); 988 eh = (struct ip6_ext *)(mtod(m, caddr_t) + eoff); 989 #else 990 IP6_EXTHDR_GET(eh, struct ip6_ext *, m, 991 eoff, sizeof(*eh)); 992 if (eh == NULL) { 993 ICMP6STAT_INC(icp6s_tooshort); 994 return (-1); 995 } 996 #endif 997 998 if (nxt == IPPROTO_AH) 999 eoff += (eh->ip6e_len + 2) << 2; 1000 else 1001 eoff += (eh->ip6e_len + 1) << 3; 1002 nxt = eh->ip6e_nxt; 1003 break; 1004 case IPPROTO_ROUTING: 1005 /* 1006 * When the erroneous packet contains a 1007 * routing header, we should examine the 1008 * header to determine the final destination. 1009 * Otherwise, we can't properly update 1010 * information that depends on the final 1011 * destination (e.g. path MTU). 1012 */ 1013 #ifndef PULLDOWN_TEST 1014 IP6_EXTHDR_CHECK(m, 0, eoff + sizeof(*rth), -1); 1015 rth = (struct ip6_rthdr *) 1016 (mtod(m, caddr_t) + eoff); 1017 #else 1018 IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m, 1019 eoff, sizeof(*rth)); 1020 if (rth == NULL) { 1021 ICMP6STAT_INC(icp6s_tooshort); 1022 return (-1); 1023 } 1024 #endif 1025 rthlen = (rth->ip6r_len + 1) << 3; 1026 /* 1027 * XXX: currently there is no 1028 * officially defined type other 1029 * than type-0. 1030 * Note that if the segment left field 1031 * is 0, all intermediate hops must 1032 * have been passed. 1033 */ 1034 if (rth->ip6r_segleft && 1035 rth->ip6r_type == IPV6_RTHDR_TYPE_0) { 1036 int hops; 1037 1038 #ifndef PULLDOWN_TEST 1039 IP6_EXTHDR_CHECK(m, 0, eoff + rthlen, -1); 1040 rth0 = (struct ip6_rthdr0 *) 1041 (mtod(m, caddr_t) + eoff); 1042 #else 1043 IP6_EXTHDR_GET(rth0, 1044 struct ip6_rthdr0 *, m, 1045 eoff, rthlen); 1046 if (rth0 == NULL) { 1047 ICMP6STAT_INC(icp6s_tooshort); 1048 return (-1); 1049 } 1050 #endif 1051 /* just ignore a bogus header */ 1052 if ((rth0->ip6r0_len % 2) == 0 && 1053 (hops = rth0->ip6r0_len/2)) 1054 finaldst = (struct in6_addr *)(rth0 + 1) + (hops - 1); 1055 } 1056 eoff += rthlen; 1057 nxt = rth->ip6r_nxt; 1058 break; 1059 case IPPROTO_FRAGMENT: 1060 #ifndef PULLDOWN_TEST 1061 IP6_EXTHDR_CHECK(m, 0, eoff + 1062 sizeof(struct ip6_frag), -1); 1063 fh = (struct ip6_frag *)(mtod(m, caddr_t) + 1064 eoff); 1065 #else 1066 IP6_EXTHDR_GET(fh, struct ip6_frag *, m, 1067 eoff, sizeof(*fh)); 1068 if (fh == NULL) { 1069 ICMP6STAT_INC(icp6s_tooshort); 1070 return (-1); 1071 } 1072 #endif 1073 /* 1074 * Data after a fragment header is meaningless 1075 * unless it is the first fragment, but 1076 * we'll go to the notify label for path MTU 1077 * discovery. 1078 */ 1079 if (fh->ip6f_offlg & IP6F_OFF_MASK) 1080 goto notify; 1081 1082 eoff += sizeof(struct ip6_frag); 1083 nxt = fh->ip6f_nxt; 1084 break; 1085 default: 1086 /* 1087 * This case includes ESP and the No Next 1088 * Header. In such cases going to the notify 1089 * label does not have any meaning 1090 * (i.e. ctlfunc will be NULL), but we go 1091 * anyway since we might have to update 1092 * path MTU information. 1093 */ 1094 goto notify; 1095 } 1096 } 1097 notify: 1098 #ifndef PULLDOWN_TEST 1099 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 1100 #else 1101 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, 1102 sizeof(*icmp6) + sizeof(struct ip6_hdr)); 1103 if (icmp6 == NULL) { 1104 ICMP6STAT_INC(icp6s_tooshort); 1105 return (-1); 1106 } 1107 #endif 1108 1109 /* 1110 * retrieve parameters from the inner IPv6 header, and convert 1111 * them into sockaddr structures. 1112 * XXX: there is no guarantee that the source or destination 1113 * addresses of the inner packet are in the same scope as 1114 * the addresses of the icmp packet. But there is no other 1115 * way to determine the zone. 1116 */ 1117 eip6 = (struct ip6_hdr *)(icmp6 + 1); 1118 1119 bzero(&icmp6dst, sizeof(icmp6dst)); 1120 icmp6dst.sin6_len = sizeof(struct sockaddr_in6); 1121 icmp6dst.sin6_family = AF_INET6; 1122 if (finaldst == NULL) 1123 icmp6dst.sin6_addr = eip6->ip6_dst; 1124 else 1125 icmp6dst.sin6_addr = *finaldst; 1126 if (in6_setscope(&icmp6dst.sin6_addr, m->m_pkthdr.rcvif, NULL)) 1127 goto freeit; 1128 bzero(&icmp6src, sizeof(icmp6src)); 1129 icmp6src.sin6_len = sizeof(struct sockaddr_in6); 1130 icmp6src.sin6_family = AF_INET6; 1131 icmp6src.sin6_addr = eip6->ip6_src; 1132 if (in6_setscope(&icmp6src.sin6_addr, m->m_pkthdr.rcvif, NULL)) 1133 goto freeit; 1134 icmp6src.sin6_flowinfo = 1135 (eip6->ip6_flow & IPV6_FLOWLABEL_MASK); 1136 1137 if (finaldst == NULL) 1138 finaldst = &eip6->ip6_dst; 1139 ip6cp.ip6c_m = m; 1140 ip6cp.ip6c_icmp6 = icmp6; 1141 ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1); 1142 ip6cp.ip6c_off = eoff; 1143 ip6cp.ip6c_finaldst = finaldst; 1144 ip6cp.ip6c_src = &icmp6src; 1145 ip6cp.ip6c_nxt = nxt; 1146 1147 if (icmp6type == ICMP6_PACKET_TOO_BIG) { 1148 notifymtu = ntohl(icmp6->icmp6_mtu); 1149 ip6cp.ip6c_cmdarg = (void *)¬ifymtu; 1150 icmp6_mtudisc_update(&ip6cp, 1); /*XXX*/ 1151 } 1152 1153 ctlfunc = (void (*)(int, struct sockaddr *, void *)) 1154 (inet6sw[ip6_protox[nxt]].pr_ctlinput); 1155 if (ctlfunc) { 1156 (void) (*ctlfunc)(code, (struct sockaddr *)&icmp6dst, 1157 &ip6cp); 1158 } 1159 } 1160 *mp = m; 1161 return (0); 1162 1163 freeit: 1164 m_freem(m); 1165 return (-1); 1166 } 1167 1168 void 1169 icmp6_mtudisc_update(struct ip6ctlparam *ip6cp, int validated) 1170 { 1171 struct in6_addr *dst = ip6cp->ip6c_finaldst; 1172 struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6; 1173 struct mbuf *m = ip6cp->ip6c_m; /* will be necessary for scope issue */ 1174 u_int mtu = ntohl(icmp6->icmp6_mtu); 1175 struct in_conninfo inc; 1176 1177 #if 0 1178 /* 1179 * RFC2460 section 5, last paragraph. 1180 * even though minimum link MTU for IPv6 is IPV6_MMTU, 1181 * we may see ICMPv6 too big with mtu < IPV6_MMTU 1182 * due to packet translator in the middle. 1183 * see ip6_output() and ip6_getpmtu() "alwaysfrag" case for 1184 * special handling. 1185 */ 1186 if (mtu < IPV6_MMTU) 1187 return; 1188 #endif 1189 1190 /* 1191 * we reject ICMPv6 too big with abnormally small value. 1192 * XXX what is the good definition of "abnormally small"? 1193 */ 1194 if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8) 1195 return; 1196 1197 if (!validated) 1198 return; 1199 1200 /* 1201 * In case the suggested mtu is less than IPV6_MMTU, we 1202 * only need to remember that it was for above mentioned 1203 * "alwaysfrag" case. 1204 * Try to be as close to the spec as possible. 1205 */ 1206 if (mtu < IPV6_MMTU) 1207 mtu = IPV6_MMTU - 8; 1208 1209 bzero(&inc, sizeof(inc)); 1210 inc.inc_fibnum = M_GETFIB(m); 1211 inc.inc_flags |= INC_ISIPV6; 1212 inc.inc6_faddr = *dst; 1213 if (in6_setscope(&inc.inc6_faddr, m->m_pkthdr.rcvif, NULL)) 1214 return; 1215 1216 if (mtu < tcp_maxmtu6(&inc, NULL)) { 1217 tcp_hc_updatemtu(&inc, mtu); 1218 ICMP6STAT_INC(icp6s_pmtuchg); 1219 } 1220 } 1221 1222 /* 1223 * Process a Node Information Query packet, based on 1224 * draft-ietf-ipngwg-icmp-name-lookups-07. 1225 * 1226 * Spec incompatibilities: 1227 * - IPv6 Subject address handling 1228 * - IPv4 Subject address handling support missing 1229 * - Proxy reply (answer even if it's not for me) 1230 * - joins NI group address at in6_ifattach() time only, does not cope 1231 * with hostname changes by sethostname(3) 1232 */ 1233 static struct mbuf * 1234 ni6_input(struct mbuf *m, int off) 1235 { 1236 struct icmp6_nodeinfo *ni6, *nni6; 1237 struct mbuf *n = NULL; 1238 struct prison *pr; 1239 u_int16_t qtype; 1240 int subjlen; 1241 int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); 1242 struct ni_reply_fqdn *fqdn; 1243 int addrs; /* for NI_QTYPE_NODEADDR */ 1244 struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */ 1245 struct in6_addr in6_subj; /* subject address */ 1246 struct ip6_hdr *ip6; 1247 int oldfqdn = 0; /* if 1, return pascal string (03 draft) */ 1248 char *subj = NULL; 1249 struct in6_ifaddr *ia6 = NULL; 1250 1251 ip6 = mtod(m, struct ip6_hdr *); 1252 #ifndef PULLDOWN_TEST 1253 ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off); 1254 #else 1255 IP6_EXTHDR_GET(ni6, struct icmp6_nodeinfo *, m, off, sizeof(*ni6)); 1256 if (ni6 == NULL) { 1257 /* m is already reclaimed */ 1258 return (NULL); 1259 } 1260 #endif 1261 1262 /* 1263 * Validate IPv6 source address. 1264 * The default configuration MUST be to refuse answering queries from 1265 * global-scope addresses according to RFC4602. 1266 * Notes: 1267 * - it's not very clear what "refuse" means; this implementation 1268 * simply drops it. 1269 * - it's not very easy to identify global-scope (unicast) addresses 1270 * since there are many prefixes for them. It should be safer 1271 * and in practice sufficient to check "all" but loopback and 1272 * link-local (note that site-local unicast was deprecated and 1273 * ULA is defined as global scope-wise) 1274 */ 1275 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_GLOBALOK) == 0 && 1276 !IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) && 1277 !IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) 1278 goto bad; 1279 1280 /* 1281 * Validate IPv6 destination address. 1282 * 1283 * The Responder must discard the Query without further processing 1284 * unless it is one of the Responder's unicast or anycast addresses, or 1285 * a link-local scope multicast address which the Responder has joined. 1286 * [RFC4602, Section 5.] 1287 */ 1288 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 1289 if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst)) 1290 goto bad; 1291 /* else it's a link-local multicast, fine */ 1292 } else { /* unicast or anycast */ 1293 ia6 = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */); 1294 if (ia6 == NULL) 1295 goto bad; /* XXX impossible */ 1296 1297 if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) && 1298 !(V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK)) { 1299 ifa_free(&ia6->ia_ifa); 1300 nd6log((LOG_DEBUG, "ni6_input: ignore node info to " 1301 "a temporary address in %s:%d", 1302 __FILE__, __LINE__)); 1303 goto bad; 1304 } 1305 ifa_free(&ia6->ia_ifa); 1306 } 1307 1308 /* validate query Subject field. */ 1309 qtype = ntohs(ni6->ni_qtype); 1310 subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo); 1311 switch (qtype) { 1312 case NI_QTYPE_NOOP: 1313 case NI_QTYPE_SUPTYPES: 1314 /* 07 draft */ 1315 if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0) 1316 break; 1317 /* FALLTHROUGH */ 1318 case NI_QTYPE_FQDN: 1319 case NI_QTYPE_NODEADDR: 1320 case NI_QTYPE_IPV4ADDR: 1321 switch (ni6->ni_code) { 1322 case ICMP6_NI_SUBJ_IPV6: 1323 #if ICMP6_NI_SUBJ_IPV6 != 0 1324 case 0: 1325 #endif 1326 /* 1327 * backward compatibility - try to accept 03 draft 1328 * format, where no Subject is present. 1329 */ 1330 if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 && 1331 subjlen == 0) { 1332 oldfqdn++; 1333 break; 1334 } 1335 #if ICMP6_NI_SUBJ_IPV6 != 0 1336 if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6) 1337 goto bad; 1338 #endif 1339 1340 if (subjlen != sizeof(struct in6_addr)) 1341 goto bad; 1342 1343 /* 1344 * Validate Subject address. 1345 * 1346 * Not sure what exactly "address belongs to the node" 1347 * means in the spec, is it just unicast, or what? 1348 * 1349 * At this moment we consider Subject address as 1350 * "belong to the node" if the Subject address equals 1351 * to the IPv6 destination address; validation for 1352 * IPv6 destination address should have done enough 1353 * check for us. 1354 * 1355 * We do not do proxy at this moment. 1356 */ 1357 /* m_pulldown instead of copy? */ 1358 m_copydata(m, off + sizeof(struct icmp6_nodeinfo), 1359 subjlen, (caddr_t)&in6_subj); 1360 if (in6_setscope(&in6_subj, m->m_pkthdr.rcvif, NULL)) 1361 goto bad; 1362 1363 subj = (char *)&in6_subj; 1364 if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &in6_subj)) 1365 break; 1366 1367 /* 1368 * XXX if we are to allow other cases, we should really 1369 * be careful about scope here. 1370 * basically, we should disallow queries toward IPv6 1371 * destination X with subject Y, 1372 * if scope(X) > scope(Y). 1373 * if we allow scope(X) > scope(Y), it will result in 1374 * information leakage across scope boundary. 1375 */ 1376 goto bad; 1377 1378 case ICMP6_NI_SUBJ_FQDN: 1379 /* 1380 * Validate Subject name with gethostname(3). 1381 * 1382 * The behavior may need some debate, since: 1383 * - we are not sure if the node has FQDN as 1384 * hostname (returned by gethostname(3)). 1385 * - the code does wildcard match for truncated names. 1386 * however, we are not sure if we want to perform 1387 * wildcard match, if gethostname(3) side has 1388 * truncated hostname. 1389 */ 1390 pr = curthread->td_ucred->cr_prison; 1391 mtx_lock(&pr->pr_mtx); 1392 n = ni6_nametodns(pr->pr_hostname, 1393 strlen(pr->pr_hostname), 0); 1394 mtx_unlock(&pr->pr_mtx); 1395 if (!n || n->m_next || n->m_len == 0) 1396 goto bad; 1397 IP6_EXTHDR_GET(subj, char *, m, 1398 off + sizeof(struct icmp6_nodeinfo), subjlen); 1399 if (subj == NULL) 1400 goto bad; 1401 if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *), 1402 n->m_len)) { 1403 goto bad; 1404 } 1405 m_freem(n); 1406 n = NULL; 1407 break; 1408 1409 case ICMP6_NI_SUBJ_IPV4: /* XXX: to be implemented? */ 1410 default: 1411 goto bad; 1412 } 1413 break; 1414 } 1415 1416 /* refuse based on configuration. XXX ICMP6_NI_REFUSED? */ 1417 switch (qtype) { 1418 case NI_QTYPE_FQDN: 1419 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_FQDNOK) == 0) 1420 goto bad; 1421 break; 1422 case NI_QTYPE_NODEADDR: 1423 case NI_QTYPE_IPV4ADDR: 1424 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_NODEADDROK) == 0) 1425 goto bad; 1426 break; 1427 } 1428 1429 /* guess reply length */ 1430 switch (qtype) { 1431 case NI_QTYPE_NOOP: 1432 break; /* no reply data */ 1433 case NI_QTYPE_SUPTYPES: 1434 replylen += sizeof(u_int32_t); 1435 break; 1436 case NI_QTYPE_FQDN: 1437 /* XXX will append an mbuf */ 1438 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); 1439 break; 1440 case NI_QTYPE_NODEADDR: 1441 addrs = ni6_addrs(ni6, m, &ifp, (struct in6_addr *)subj); 1442 if ((replylen += addrs * (sizeof(struct in6_addr) + 1443 sizeof(u_int32_t))) > MCLBYTES) 1444 replylen = MCLBYTES; /* XXX: will truncate pkt later */ 1445 break; 1446 case NI_QTYPE_IPV4ADDR: 1447 /* unsupported - should respond with unknown Qtype? */ 1448 break; 1449 default: 1450 /* 1451 * XXX: We must return a reply with the ICMP6 code 1452 * `unknown Qtype' in this case. However we regard the case 1453 * as an FQDN query for backward compatibility. 1454 * Older versions set a random value to this field, 1455 * so it rarely varies in the defined qtypes. 1456 * But the mechanism is not reliable... 1457 * maybe we should obsolete older versions. 1458 */ 1459 qtype = NI_QTYPE_FQDN; 1460 /* XXX will append an mbuf */ 1461 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); 1462 oldfqdn++; 1463 break; 1464 } 1465 1466 /* Allocate an mbuf to reply. */ 1467 if (replylen > MCLBYTES) { 1468 /* 1469 * XXX: should we try to allocate more? But MCLBYTES 1470 * is probably much larger than IPV6_MMTU... 1471 */ 1472 goto bad; 1473 } 1474 if (replylen > MHLEN) 1475 n = m_getcl(M_NOWAIT, m->m_type, M_PKTHDR); 1476 else 1477 n = m_gethdr(M_NOWAIT, m->m_type); 1478 if (n == NULL) { 1479 m_freem(m); 1480 return (NULL); 1481 } 1482 m_move_pkthdr(n, m); /* just for recvif and FIB */ 1483 n->m_pkthdr.len = n->m_len = replylen; 1484 1485 /* copy mbuf header and IPv6 + Node Information base headers */ 1486 bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr)); 1487 nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1); 1488 bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo)); 1489 1490 /* qtype dependent procedure */ 1491 switch (qtype) { 1492 case NI_QTYPE_NOOP: 1493 nni6->ni_code = ICMP6_NI_SUCCESS; 1494 nni6->ni_flags = 0; 1495 break; 1496 case NI_QTYPE_SUPTYPES: 1497 { 1498 u_int32_t v; 1499 nni6->ni_code = ICMP6_NI_SUCCESS; 1500 nni6->ni_flags = htons(0x0000); /* raw bitmap */ 1501 /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */ 1502 v = (u_int32_t)htonl(0x0000000f); 1503 bcopy(&v, nni6 + 1, sizeof(u_int32_t)); 1504 break; 1505 } 1506 case NI_QTYPE_FQDN: 1507 nni6->ni_code = ICMP6_NI_SUCCESS; 1508 fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) + 1509 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo)); 1510 nni6->ni_flags = 0; /* XXX: meaningless TTL */ 1511 fqdn->ni_fqdn_ttl = 0; /* ditto. */ 1512 /* 1513 * XXX do we really have FQDN in hostname? 1514 */ 1515 pr = curthread->td_ucred->cr_prison; 1516 mtx_lock(&pr->pr_mtx); 1517 n->m_next = ni6_nametodns(pr->pr_hostname, 1518 strlen(pr->pr_hostname), oldfqdn); 1519 mtx_unlock(&pr->pr_mtx); 1520 if (n->m_next == NULL) 1521 goto bad; 1522 /* XXX we assume that n->m_next is not a chain */ 1523 if (n->m_next->m_next != NULL) 1524 goto bad; 1525 n->m_pkthdr.len += n->m_next->m_len; 1526 break; 1527 case NI_QTYPE_NODEADDR: 1528 { 1529 int lenlim, copied; 1530 1531 nni6->ni_code = ICMP6_NI_SUCCESS; 1532 n->m_pkthdr.len = n->m_len = 1533 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); 1534 lenlim = M_TRAILINGSPACE(n); 1535 copied = ni6_store_addrs(ni6, nni6, ifp, lenlim); 1536 /* XXX: reset mbuf length */ 1537 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + 1538 sizeof(struct icmp6_nodeinfo) + copied; 1539 break; 1540 } 1541 default: 1542 break; /* XXX impossible! */ 1543 } 1544 1545 nni6->ni_type = ICMP6_NI_REPLY; 1546 m_freem(m); 1547 return (n); 1548 1549 bad: 1550 m_freem(m); 1551 if (n) 1552 m_freem(n); 1553 return (NULL); 1554 } 1555 1556 /* 1557 * make a mbuf with DNS-encoded string. no compression support. 1558 * 1559 * XXX names with less than 2 dots (like "foo" or "foo.section") will be 1560 * treated as truncated name (two \0 at the end). this is a wild guess. 1561 * 1562 * old - return pascal string if non-zero 1563 */ 1564 static struct mbuf * 1565 ni6_nametodns(const char *name, int namelen, int old) 1566 { 1567 struct mbuf *m; 1568 char *cp, *ep; 1569 const char *p, *q; 1570 int i, len, nterm; 1571 1572 if (old) 1573 len = namelen + 1; 1574 else 1575 len = MCLBYTES; 1576 1577 /* Because MAXHOSTNAMELEN is usually 256, we use cluster mbuf. */ 1578 if (len > MLEN) 1579 m = m_getcl(M_NOWAIT, MT_DATA, 0); 1580 else 1581 m = m_get(M_NOWAIT, MT_DATA); 1582 if (m == NULL) 1583 goto fail; 1584 1585 if (old) { 1586 m->m_len = len; 1587 *mtod(m, char *) = namelen; 1588 bcopy(name, mtod(m, char *) + 1, namelen); 1589 return m; 1590 } else { 1591 m->m_len = 0; 1592 cp = mtod(m, char *); 1593 ep = mtod(m, char *) + M_TRAILINGSPACE(m); 1594 1595 /* if not certain about my name, return empty buffer */ 1596 if (namelen == 0) 1597 return m; 1598 1599 /* 1600 * guess if it looks like shortened hostname, or FQDN. 1601 * shortened hostname needs two trailing "\0". 1602 */ 1603 i = 0; 1604 for (p = name; p < name + namelen; p++) { 1605 if (*p && *p == '.') 1606 i++; 1607 } 1608 if (i < 2) 1609 nterm = 2; 1610 else 1611 nterm = 1; 1612 1613 p = name; 1614 while (cp < ep && p < name + namelen) { 1615 i = 0; 1616 for (q = p; q < name + namelen && *q && *q != '.'; q++) 1617 i++; 1618 /* result does not fit into mbuf */ 1619 if (cp + i + 1 >= ep) 1620 goto fail; 1621 /* 1622 * DNS label length restriction, RFC1035 page 8. 1623 * "i == 0" case is included here to avoid returning 1624 * 0-length label on "foo..bar". 1625 */ 1626 if (i <= 0 || i >= 64) 1627 goto fail; 1628 *cp++ = i; 1629 bcopy(p, cp, i); 1630 cp += i; 1631 p = q; 1632 if (p < name + namelen && *p == '.') 1633 p++; 1634 } 1635 /* termination */ 1636 if (cp + nterm >= ep) 1637 goto fail; 1638 while (nterm-- > 0) 1639 *cp++ = '\0'; 1640 m->m_len = cp - mtod(m, char *); 1641 return m; 1642 } 1643 1644 panic("should not reach here"); 1645 /* NOTREACHED */ 1646 1647 fail: 1648 if (m) 1649 m_freem(m); 1650 return NULL; 1651 } 1652 1653 /* 1654 * check if two DNS-encoded string matches. takes care of truncated 1655 * form (with \0\0 at the end). no compression support. 1656 * XXX upper/lowercase match (see RFC2065) 1657 */ 1658 static int 1659 ni6_dnsmatch(const char *a, int alen, const char *b, int blen) 1660 { 1661 const char *a0, *b0; 1662 int l; 1663 1664 /* simplest case - need validation? */ 1665 if (alen == blen && bcmp(a, b, alen) == 0) 1666 return 1; 1667 1668 a0 = a; 1669 b0 = b; 1670 1671 /* termination is mandatory */ 1672 if (alen < 2 || blen < 2) 1673 return 0; 1674 if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0') 1675 return 0; 1676 alen--; 1677 blen--; 1678 1679 while (a - a0 < alen && b - b0 < blen) { 1680 if (a - a0 + 1 > alen || b - b0 + 1 > blen) 1681 return 0; 1682 1683 if ((signed char)a[0] < 0 || (signed char)b[0] < 0) 1684 return 0; 1685 /* we don't support compression yet */ 1686 if (a[0] >= 64 || b[0] >= 64) 1687 return 0; 1688 1689 /* truncated case */ 1690 if (a[0] == 0 && a - a0 == alen - 1) 1691 return 1; 1692 if (b[0] == 0 && b - b0 == blen - 1) 1693 return 1; 1694 if (a[0] == 0 || b[0] == 0) 1695 return 0; 1696 1697 if (a[0] != b[0]) 1698 return 0; 1699 l = a[0]; 1700 if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen) 1701 return 0; 1702 if (bcmp(a + 1, b + 1, l) != 0) 1703 return 0; 1704 1705 a += 1 + l; 1706 b += 1 + l; 1707 } 1708 1709 if (a - a0 == alen && b - b0 == blen) 1710 return 1; 1711 else 1712 return 0; 1713 } 1714 1715 /* 1716 * calculate the number of addresses to be returned in the node info reply. 1717 */ 1718 static int 1719 ni6_addrs(struct icmp6_nodeinfo *ni6, struct mbuf *m, struct ifnet **ifpp, 1720 struct in6_addr *subj) 1721 { 1722 struct ifnet *ifp; 1723 struct in6_ifaddr *ifa6; 1724 struct ifaddr *ifa; 1725 int addrs = 0, addrsofif, iffound = 0; 1726 int niflags = ni6->ni_flags; 1727 1728 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) { 1729 switch (ni6->ni_code) { 1730 case ICMP6_NI_SUBJ_IPV6: 1731 if (subj == NULL) /* must be impossible... */ 1732 return (0); 1733 break; 1734 default: 1735 /* 1736 * XXX: we only support IPv6 subject address for 1737 * this Qtype. 1738 */ 1739 return (0); 1740 } 1741 } 1742 1743 IFNET_RLOCK_NOSLEEP(); 1744 TAILQ_FOREACH(ifp, &V_ifnet, if_link) { 1745 addrsofif = 0; 1746 IF_ADDR_RLOCK(ifp); 1747 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 1748 if (ifa->ifa_addr->sa_family != AF_INET6) 1749 continue; 1750 ifa6 = (struct in6_ifaddr *)ifa; 1751 1752 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 && 1753 IN6_ARE_ADDR_EQUAL(subj, &ifa6->ia_addr.sin6_addr)) 1754 iffound = 1; 1755 1756 /* 1757 * IPv4-mapped addresses can only be returned by a 1758 * Node Information proxy, since they represent 1759 * addresses of IPv4-only nodes, which perforce do 1760 * not implement this protocol. 1761 * [icmp-name-lookups-07, Section 5.4] 1762 * So we don't support NI_NODEADDR_FLAG_COMPAT in 1763 * this function at this moment. 1764 */ 1765 1766 /* What do we have to do about ::1? */ 1767 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { 1768 case IPV6_ADDR_SCOPE_LINKLOCAL: 1769 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) 1770 continue; 1771 break; 1772 case IPV6_ADDR_SCOPE_SITELOCAL: 1773 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) 1774 continue; 1775 break; 1776 case IPV6_ADDR_SCOPE_GLOBAL: 1777 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) 1778 continue; 1779 break; 1780 default: 1781 continue; 1782 } 1783 1784 /* 1785 * check if anycast is okay. 1786 * XXX: just experimental. not in the spec. 1787 */ 1788 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && 1789 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) 1790 continue; /* we need only unicast addresses */ 1791 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && 1792 (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) { 1793 continue; 1794 } 1795 addrsofif++; /* count the address */ 1796 } 1797 IF_ADDR_RUNLOCK(ifp); 1798 if (iffound) { 1799 *ifpp = ifp; 1800 IFNET_RUNLOCK_NOSLEEP(); 1801 return (addrsofif); 1802 } 1803 1804 addrs += addrsofif; 1805 } 1806 IFNET_RUNLOCK_NOSLEEP(); 1807 1808 return (addrs); 1809 } 1810 1811 static int 1812 ni6_store_addrs(struct icmp6_nodeinfo *ni6, struct icmp6_nodeinfo *nni6, 1813 struct ifnet *ifp0, int resid) 1814 { 1815 struct ifnet *ifp; 1816 struct in6_ifaddr *ifa6; 1817 struct ifaddr *ifa; 1818 struct ifnet *ifp_dep = NULL; 1819 int copied = 0, allow_deprecated = 0; 1820 u_char *cp = (u_char *)(nni6 + 1); 1821 int niflags = ni6->ni_flags; 1822 u_int32_t ltime; 1823 1824 if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL)) 1825 return (0); /* needless to copy */ 1826 1827 IFNET_RLOCK_NOSLEEP(); 1828 ifp = ifp0 ? ifp0 : TAILQ_FIRST(&V_ifnet); 1829 again: 1830 1831 for (; ifp; ifp = TAILQ_NEXT(ifp, if_link)) { 1832 IF_ADDR_RLOCK(ifp); 1833 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 1834 if (ifa->ifa_addr->sa_family != AF_INET6) 1835 continue; 1836 ifa6 = (struct in6_ifaddr *)ifa; 1837 1838 if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 && 1839 allow_deprecated == 0) { 1840 /* 1841 * prefererred address should be put before 1842 * deprecated addresses. 1843 */ 1844 1845 /* record the interface for later search */ 1846 if (ifp_dep == NULL) 1847 ifp_dep = ifp; 1848 1849 continue; 1850 } else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 && 1851 allow_deprecated != 0) 1852 continue; /* we now collect deprecated addrs */ 1853 1854 /* What do we have to do about ::1? */ 1855 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { 1856 case IPV6_ADDR_SCOPE_LINKLOCAL: 1857 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) 1858 continue; 1859 break; 1860 case IPV6_ADDR_SCOPE_SITELOCAL: 1861 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) 1862 continue; 1863 break; 1864 case IPV6_ADDR_SCOPE_GLOBAL: 1865 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) 1866 continue; 1867 break; 1868 default: 1869 continue; 1870 } 1871 1872 /* 1873 * check if anycast is okay. 1874 * XXX: just experimental. not in the spec. 1875 */ 1876 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && 1877 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) 1878 continue; 1879 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && 1880 (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) { 1881 continue; 1882 } 1883 1884 /* now we can copy the address */ 1885 if (resid < sizeof(struct in6_addr) + 1886 sizeof(u_int32_t)) { 1887 IF_ADDR_RUNLOCK(ifp); 1888 /* 1889 * We give up much more copy. 1890 * Set the truncate flag and return. 1891 */ 1892 nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE; 1893 IFNET_RUNLOCK_NOSLEEP(); 1894 return (copied); 1895 } 1896 1897 /* 1898 * Set the TTL of the address. 1899 * The TTL value should be one of the following 1900 * according to the specification: 1901 * 1902 * 1. The remaining lifetime of a DHCP lease on the 1903 * address, or 1904 * 2. The remaining Valid Lifetime of a prefix from 1905 * which the address was derived through Stateless 1906 * Autoconfiguration. 1907 * 1908 * Note that we currently do not support stateful 1909 * address configuration by DHCPv6, so the former 1910 * case can't happen. 1911 */ 1912 if (ifa6->ia6_lifetime.ia6t_expire == 0) 1913 ltime = ND6_INFINITE_LIFETIME; 1914 else { 1915 if (ifa6->ia6_lifetime.ia6t_expire > 1916 time_uptime) 1917 ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_uptime); 1918 else 1919 ltime = 0; 1920 } 1921 1922 bcopy(<ime, cp, sizeof(u_int32_t)); 1923 cp += sizeof(u_int32_t); 1924 1925 /* copy the address itself */ 1926 bcopy(&ifa6->ia_addr.sin6_addr, cp, 1927 sizeof(struct in6_addr)); 1928 in6_clearscope((struct in6_addr *)cp); /* XXX */ 1929 cp += sizeof(struct in6_addr); 1930 1931 resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t)); 1932 copied += (sizeof(struct in6_addr) + sizeof(u_int32_t)); 1933 } 1934 IF_ADDR_RUNLOCK(ifp); 1935 if (ifp0) /* we need search only on the specified IF */ 1936 break; 1937 } 1938 1939 if (allow_deprecated == 0 && ifp_dep != NULL) { 1940 ifp = ifp_dep; 1941 allow_deprecated = 1; 1942 1943 goto again; 1944 } 1945 1946 IFNET_RUNLOCK_NOSLEEP(); 1947 1948 return (copied); 1949 } 1950 1951 /* 1952 * XXX almost dup'ed code with rip6_input. 1953 */ 1954 static int 1955 icmp6_rip6_input(struct mbuf **mp, int off) 1956 { 1957 struct mbuf *m = *mp; 1958 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1959 struct inpcb *in6p; 1960 struct inpcb *last = NULL; 1961 struct sockaddr_in6 fromsa; 1962 struct icmp6_hdr *icmp6; 1963 struct mbuf *opts = NULL; 1964 1965 #ifndef PULLDOWN_TEST 1966 /* this is assumed to be safe. */ 1967 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off); 1968 #else 1969 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6)); 1970 if (icmp6 == NULL) { 1971 /* m is already reclaimed */ 1972 return (IPPROTO_DONE); 1973 } 1974 #endif 1975 1976 /* 1977 * XXX: the address may have embedded scope zone ID, which should be 1978 * hidden from applications. 1979 */ 1980 bzero(&fromsa, sizeof(fromsa)); 1981 fromsa.sin6_family = AF_INET6; 1982 fromsa.sin6_len = sizeof(struct sockaddr_in6); 1983 fromsa.sin6_addr = ip6->ip6_src; 1984 if (sa6_recoverscope(&fromsa)) { 1985 m_freem(m); 1986 return (IPPROTO_DONE); 1987 } 1988 1989 INP_INFO_RLOCK(&V_ripcbinfo); 1990 LIST_FOREACH(in6p, &V_ripcb, inp_list) { 1991 if ((in6p->inp_vflag & INP_IPV6) == 0) 1992 continue; 1993 if (in6p->inp_ip_p != IPPROTO_ICMPV6) 1994 continue; 1995 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) && 1996 !IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &ip6->ip6_dst)) 1997 continue; 1998 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr) && 1999 !IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src)) 2000 continue; 2001 INP_RLOCK(in6p); 2002 if (ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type, 2003 in6p->in6p_icmp6filt)) { 2004 INP_RUNLOCK(in6p); 2005 continue; 2006 } 2007 if (last != NULL) { 2008 struct mbuf *n = NULL; 2009 2010 /* 2011 * Recent network drivers tend to allocate a single 2012 * mbuf cluster, rather than to make a couple of 2013 * mbufs without clusters. Also, since the IPv6 code 2014 * path tries to avoid m_pullup(), it is highly 2015 * probable that we still have an mbuf cluster here 2016 * even though the necessary length can be stored in an 2017 * mbuf's internal buffer. 2018 * Meanwhile, the default size of the receive socket 2019 * buffer for raw sockets is not so large. This means 2020 * the possibility of packet loss is relatively higher 2021 * than before. To avoid this scenario, we copy the 2022 * received data to a separate mbuf that does not use 2023 * a cluster, if possible. 2024 * XXX: it is better to copy the data after stripping 2025 * intermediate headers. 2026 */ 2027 if ((m->m_flags & M_EXT) && m->m_next == NULL && 2028 m->m_len <= MHLEN) { 2029 n = m_get(M_NOWAIT, m->m_type); 2030 if (n != NULL) { 2031 if (m_dup_pkthdr(n, m, M_NOWAIT)) { 2032 bcopy(m->m_data, n->m_data, 2033 m->m_len); 2034 n->m_len = m->m_len; 2035 } else { 2036 m_free(n); 2037 n = NULL; 2038 } 2039 } 2040 } 2041 if (n != NULL || 2042 (n = m_copy(m, 0, (int)M_COPYALL)) != NULL) { 2043 if (last->inp_flags & INP_CONTROLOPTS) 2044 ip6_savecontrol(last, n, &opts); 2045 /* strip intermediate headers */ 2046 m_adj(n, off); 2047 SOCKBUF_LOCK(&last->inp_socket->so_rcv); 2048 if (sbappendaddr_locked( 2049 &last->inp_socket->so_rcv, 2050 (struct sockaddr *)&fromsa, n, opts) 2051 == 0) { 2052 /* should notify about lost packet */ 2053 m_freem(n); 2054 if (opts) { 2055 m_freem(opts); 2056 } 2057 SOCKBUF_UNLOCK( 2058 &last->inp_socket->so_rcv); 2059 } else 2060 sorwakeup_locked(last->inp_socket); 2061 opts = NULL; 2062 } 2063 INP_RUNLOCK(last); 2064 } 2065 last = in6p; 2066 } 2067 INP_INFO_RUNLOCK(&V_ripcbinfo); 2068 if (last != NULL) { 2069 if (last->inp_flags & INP_CONTROLOPTS) 2070 ip6_savecontrol(last, m, &opts); 2071 /* strip intermediate headers */ 2072 m_adj(m, off); 2073 2074 /* avoid using mbuf clusters if possible (see above) */ 2075 if ((m->m_flags & M_EXT) && m->m_next == NULL && 2076 m->m_len <= MHLEN) { 2077 struct mbuf *n; 2078 2079 n = m_get(M_NOWAIT, m->m_type); 2080 if (n != NULL) { 2081 if (m_dup_pkthdr(n, m, M_NOWAIT)) { 2082 bcopy(m->m_data, n->m_data, m->m_len); 2083 n->m_len = m->m_len; 2084 2085 m_freem(m); 2086 m = n; 2087 } else { 2088 m_freem(n); 2089 n = NULL; 2090 } 2091 } 2092 } 2093 SOCKBUF_LOCK(&last->inp_socket->so_rcv); 2094 if (sbappendaddr_locked(&last->inp_socket->so_rcv, 2095 (struct sockaddr *)&fromsa, m, opts) == 0) { 2096 m_freem(m); 2097 if (opts) 2098 m_freem(opts); 2099 SOCKBUF_UNLOCK(&last->inp_socket->so_rcv); 2100 } else 2101 sorwakeup_locked(last->inp_socket); 2102 INP_RUNLOCK(last); 2103 } else { 2104 m_freem(m); 2105 IP6STAT_DEC(ip6s_delivered); 2106 } 2107 return IPPROTO_DONE; 2108 } 2109 2110 /* 2111 * Reflect the ip6 packet back to the source. 2112 * OFF points to the icmp6 header, counted from the top of the mbuf. 2113 */ 2114 void 2115 icmp6_reflect(struct mbuf *m, size_t off) 2116 { 2117 struct in6_addr src6, *srcp; 2118 struct ip6_hdr *ip6; 2119 struct icmp6_hdr *icmp6; 2120 struct in6_ifaddr *ia = NULL; 2121 struct ifnet *outif = NULL; 2122 int plen; 2123 int type, code, hlim; 2124 2125 /* too short to reflect */ 2126 if (off < sizeof(struct ip6_hdr)) { 2127 nd6log((LOG_DEBUG, 2128 "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n", 2129 (u_long)off, (u_long)sizeof(struct ip6_hdr), 2130 __FILE__, __LINE__)); 2131 goto bad; 2132 } 2133 2134 /* 2135 * If there are extra headers between IPv6 and ICMPv6, strip 2136 * off that header first. 2137 */ 2138 #ifdef DIAGNOSTIC 2139 if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN) 2140 panic("assumption failed in icmp6_reflect"); 2141 #endif 2142 if (off > sizeof(struct ip6_hdr)) { 2143 size_t l; 2144 struct ip6_hdr nip6; 2145 2146 l = off - sizeof(struct ip6_hdr); 2147 m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6); 2148 m_adj(m, l); 2149 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 2150 if (m->m_len < l) { 2151 if ((m = m_pullup(m, l)) == NULL) 2152 return; 2153 } 2154 bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6)); 2155 } else /* off == sizeof(struct ip6_hdr) */ { 2156 size_t l; 2157 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 2158 if (m->m_len < l) { 2159 if ((m = m_pullup(m, l)) == NULL) 2160 return; 2161 } 2162 } 2163 plen = m->m_pkthdr.len - sizeof(struct ip6_hdr); 2164 ip6 = mtod(m, struct ip6_hdr *); 2165 ip6->ip6_nxt = IPPROTO_ICMPV6; 2166 icmp6 = (struct icmp6_hdr *)(ip6 + 1); 2167 type = icmp6->icmp6_type; /* keep type for statistics */ 2168 code = icmp6->icmp6_code; /* ditto. */ 2169 hlim = 0; 2170 srcp = NULL; 2171 2172 /* 2173 * If the incoming packet was addressed directly to us (i.e. unicast), 2174 * use dst as the src for the reply. 2175 * The IN6_IFF_NOTREADY case should be VERY rare, but is possible 2176 * (for example) when we encounter an error while forwarding procedure 2177 * destined to a duplicated address of ours. 2178 */ 2179 if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 2180 ia = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */); 2181 if (ia != NULL && !(ia->ia6_flags & 2182 (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) { 2183 src6 = ia->ia_addr.sin6_addr; 2184 srcp = &src6; 2185 2186 if (m->m_pkthdr.rcvif != NULL) { 2187 /* XXX: This may not be the outgoing interface */ 2188 hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim; 2189 } else 2190 hlim = V_ip6_defhlim; 2191 } 2192 if (ia != NULL) 2193 ifa_free(&ia->ia_ifa); 2194 } 2195 2196 if (srcp == NULL) { 2197 int error; 2198 struct in6_addr dst6; 2199 uint32_t scopeid; 2200 2201 /* 2202 * This case matches to multicasts, our anycast, or unicasts 2203 * that we do not own. Select a source address based on the 2204 * source address of the erroneous packet. 2205 */ 2206 in6_splitscope(&ip6->ip6_dst, &dst6, &scopeid); 2207 error = in6_selectsrc_addr(RT_DEFAULT_FIB, &dst6, 2208 scopeid, NULL, &src6, &hlim); 2209 2210 if (error) { 2211 char ip6buf[INET6_ADDRSTRLEN]; 2212 nd6log((LOG_DEBUG, 2213 "icmp6_reflect: source can't be determined: " 2214 "dst=%s, error=%d\n", 2215 ip6_sprintf(ip6buf, &ip6->ip6_dst), error)); 2216 goto bad; 2217 } 2218 srcp = &src6; 2219 } 2220 /* 2221 * ip6_input() drops a packet if its src is multicast. 2222 * So, the src is never multicast. 2223 */ 2224 ip6->ip6_dst = ip6->ip6_src; 2225 ip6->ip6_src = *srcp; 2226 ip6->ip6_flow = 0; 2227 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2228 ip6->ip6_vfc |= IPV6_VERSION; 2229 ip6->ip6_nxt = IPPROTO_ICMPV6; 2230 ip6->ip6_hlim = hlim; 2231 2232 icmp6->icmp6_cksum = 0; 2233 icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2234 sizeof(struct ip6_hdr), plen); 2235 2236 /* 2237 * XXX option handling 2238 */ 2239 2240 m->m_flags &= ~(M_BCAST|M_MCAST); 2241 2242 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2243 if (outif) 2244 icmp6_ifoutstat_inc(outif, type, code); 2245 2246 return; 2247 2248 bad: 2249 m_freem(m); 2250 return; 2251 } 2252 2253 void 2254 icmp6_fasttimo(void) 2255 { 2256 2257 mld_fasttimo(); 2258 } 2259 2260 void 2261 icmp6_slowtimo(void) 2262 { 2263 2264 mld_slowtimo(); 2265 } 2266 2267 static const char * 2268 icmp6_redirect_diag(struct in6_addr *src6, struct in6_addr *dst6, 2269 struct in6_addr *tgt6) 2270 { 2271 static char buf[1024]; 2272 char ip6bufs[INET6_ADDRSTRLEN]; 2273 char ip6bufd[INET6_ADDRSTRLEN]; 2274 char ip6buft[INET6_ADDRSTRLEN]; 2275 snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)", 2276 ip6_sprintf(ip6bufs, src6), ip6_sprintf(ip6bufd, dst6), 2277 ip6_sprintf(ip6buft, tgt6)); 2278 return buf; 2279 } 2280 2281 void 2282 icmp6_redirect_input(struct mbuf *m, int off) 2283 { 2284 struct ifnet *ifp; 2285 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 2286 struct nd_redirect *nd_rd; 2287 int icmp6len = ntohs(ip6->ip6_plen); 2288 char *lladdr = NULL; 2289 int lladdrlen = 0; 2290 int is_router; 2291 int is_onlink; 2292 struct in6_addr src6 = ip6->ip6_src; 2293 struct in6_addr redtgt6; 2294 struct in6_addr reddst6; 2295 union nd_opts ndopts; 2296 char ip6buf[INET6_ADDRSTRLEN]; 2297 2298 M_ASSERTPKTHDR(m); 2299 KASSERT(m->m_pkthdr.rcvif != NULL, ("%s: no rcvif", __func__)); 2300 2301 ifp = m->m_pkthdr.rcvif; 2302 2303 /* XXX if we are router, we don't update route by icmp6 redirect */ 2304 if (V_ip6_forwarding) 2305 goto freeit; 2306 if (!V_icmp6_rediraccept) 2307 goto freeit; 2308 2309 #ifndef PULLDOWN_TEST 2310 IP6_EXTHDR_CHECK(m, off, icmp6len,); 2311 nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off); 2312 #else 2313 IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len); 2314 if (nd_rd == NULL) { 2315 ICMP6STAT_INC(icp6s_tooshort); 2316 return; 2317 } 2318 #endif 2319 redtgt6 = nd_rd->nd_rd_target; 2320 reddst6 = nd_rd->nd_rd_dst; 2321 2322 if (in6_setscope(&redtgt6, m->m_pkthdr.rcvif, NULL) || 2323 in6_setscope(&reddst6, m->m_pkthdr.rcvif, NULL)) { 2324 goto freeit; 2325 } 2326 2327 /* validation */ 2328 if (!IN6_IS_ADDR_LINKLOCAL(&src6)) { 2329 nd6log((LOG_ERR, 2330 "ICMP6 redirect sent from %s rejected; " 2331 "must be from linklocal\n", 2332 ip6_sprintf(ip6buf, &src6))); 2333 goto bad; 2334 } 2335 if (ip6->ip6_hlim != 255) { 2336 nd6log((LOG_ERR, 2337 "ICMP6 redirect sent from %s rejected; " 2338 "hlim=%d (must be 255)\n", 2339 ip6_sprintf(ip6buf, &src6), ip6->ip6_hlim)); 2340 goto bad; 2341 } 2342 { 2343 /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */ 2344 struct nhop6_basic nh6; 2345 struct in6_addr kdst; 2346 uint32_t scopeid; 2347 2348 in6_splitscope(&reddst6, &kdst, &scopeid); 2349 if (fib6_lookup_nh_basic(RT_DEFAULT_FIB, &kdst, scopeid, 0, 0,&nh6)==0){ 2350 if ((nh6.nh_flags & NHF_GATEWAY) == 0) { 2351 nd6log((LOG_ERR, 2352 "ICMP6 redirect rejected; no route " 2353 "with inet6 gateway found for redirect dst: %s\n", 2354 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2355 goto bad; 2356 } 2357 2358 if (IN6_ARE_ADDR_EQUAL(&src6, &nh6.nh_addr) == 0) { 2359 nd6log((LOG_ERR, 2360 "ICMP6 redirect rejected; " 2361 "not equal to gw-for-src=%s (must be same): " 2362 "%s\n", 2363 ip6_sprintf(ip6buf, &nh6.nh_addr), 2364 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2365 goto bad; 2366 } 2367 } else { 2368 nd6log((LOG_ERR, 2369 "ICMP6 redirect rejected; " 2370 "no route found for redirect dst: %s\n", 2371 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2372 goto bad; 2373 } 2374 } 2375 if (IN6_IS_ADDR_MULTICAST(&reddst6)) { 2376 nd6log((LOG_ERR, 2377 "ICMP6 redirect rejected; " 2378 "redirect dst must be unicast: %s\n", 2379 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2380 goto bad; 2381 } 2382 2383 is_router = is_onlink = 0; 2384 if (IN6_IS_ADDR_LINKLOCAL(&redtgt6)) 2385 is_router = 1; /* router case */ 2386 if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0) 2387 is_onlink = 1; /* on-link destination case */ 2388 if (!is_router && !is_onlink) { 2389 nd6log((LOG_ERR, 2390 "ICMP6 redirect rejected; " 2391 "neither router case nor onlink case: %s\n", 2392 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2393 goto bad; 2394 } 2395 2396 icmp6len -= sizeof(*nd_rd); 2397 nd6_option_init(nd_rd + 1, icmp6len, &ndopts); 2398 if (nd6_options(&ndopts) < 0) { 2399 nd6log((LOG_INFO, "%s: invalid ND option, rejected: %s\n", 2400 __func__, icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2401 /* nd6_options have incremented stats */ 2402 goto freeit; 2403 } 2404 2405 if (ndopts.nd_opts_tgt_lladdr) { 2406 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 2407 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 2408 } 2409 2410 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 2411 nd6log((LOG_INFO, "%s: lladdrlen mismatch for %s " 2412 "(if %d, icmp6 packet %d): %s\n", 2413 __func__, ip6_sprintf(ip6buf, &redtgt6), 2414 ifp->if_addrlen, lladdrlen - 2, 2415 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2416 goto bad; 2417 } 2418 2419 /* Validation passed. */ 2420 2421 /* RFC 2461 8.3 */ 2422 nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT, 2423 is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER); 2424 2425 /* 2426 * Install a gateway route in the better-router case or an interface 2427 * route in the on-link-destination case. 2428 */ 2429 { 2430 struct sockaddr_in6 sdst; 2431 struct sockaddr_in6 sgw; 2432 struct sockaddr_in6 ssrc; 2433 struct sockaddr *gw; 2434 int rt_flags; 2435 u_int fibnum; 2436 2437 bzero(&sdst, sizeof(sdst)); 2438 bzero(&ssrc, sizeof(ssrc)); 2439 sdst.sin6_family = ssrc.sin6_family = AF_INET6; 2440 sdst.sin6_len = ssrc.sin6_len = sizeof(struct sockaddr_in6); 2441 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr)); 2442 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr)); 2443 rt_flags = RTF_HOST; 2444 if (is_router) { 2445 bzero(&sgw, sizeof(sgw)); 2446 sgw.sin6_family = AF_INET6; 2447 sgw.sin6_len = sizeof(struct sockaddr_in6); 2448 bcopy(&redtgt6, &sgw.sin6_addr, 2449 sizeof(struct in6_addr)); 2450 gw = (struct sockaddr *)&sgw; 2451 rt_flags |= RTF_GATEWAY; 2452 } else 2453 gw = ifp->if_addr->ifa_addr; 2454 for (fibnum = 0; fibnum < rt_numfibs; fibnum++) 2455 in6_rtredirect((struct sockaddr *)&sdst, gw, 2456 (struct sockaddr *)NULL, rt_flags, 2457 (struct sockaddr *)&ssrc, fibnum); 2458 } 2459 /* finally update cached route in each socket via pfctlinput */ 2460 { 2461 struct sockaddr_in6 sdst; 2462 2463 bzero(&sdst, sizeof(sdst)); 2464 sdst.sin6_family = AF_INET6; 2465 sdst.sin6_len = sizeof(struct sockaddr_in6); 2466 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr)); 2467 pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst); 2468 } 2469 2470 freeit: 2471 m_freem(m); 2472 return; 2473 2474 bad: 2475 ICMP6STAT_INC(icp6s_badredirect); 2476 m_freem(m); 2477 } 2478 2479 void 2480 icmp6_redirect_output(struct mbuf *m0, struct rtentry *rt) 2481 { 2482 struct ifnet *ifp; /* my outgoing interface */ 2483 struct in6_addr *ifp_ll6; 2484 struct in6_addr *router_ll6; 2485 struct ip6_hdr *sip6; /* m0 as struct ip6_hdr */ 2486 struct mbuf *m = NULL; /* newly allocated one */ 2487 struct m_tag *mtag; 2488 struct ip6_hdr *ip6; /* m as struct ip6_hdr */ 2489 struct nd_redirect *nd_rd; 2490 struct llentry *ln = NULL; 2491 size_t maxlen; 2492 u_char *p; 2493 struct ifnet *outif = NULL; 2494 struct sockaddr_in6 src_sa; 2495 2496 icmp6_errcount(ND_REDIRECT, 0); 2497 2498 /* if we are not router, we don't send icmp6 redirect */ 2499 if (!V_ip6_forwarding) 2500 goto fail; 2501 2502 /* sanity check */ 2503 if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp)) 2504 goto fail; 2505 2506 /* 2507 * Address check: 2508 * the source address must identify a neighbor, and 2509 * the destination address must not be a multicast address 2510 * [RFC 2461, sec 8.2] 2511 */ 2512 sip6 = mtod(m0, struct ip6_hdr *); 2513 bzero(&src_sa, sizeof(src_sa)); 2514 src_sa.sin6_family = AF_INET6; 2515 src_sa.sin6_len = sizeof(src_sa); 2516 src_sa.sin6_addr = sip6->ip6_src; 2517 if (nd6_is_addr_neighbor(&src_sa, ifp) == 0) 2518 goto fail; 2519 if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst)) 2520 goto fail; /* what should we do here? */ 2521 2522 /* rate limit */ 2523 if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0)) 2524 goto fail; 2525 2526 /* 2527 * Since we are going to append up to 1280 bytes (= IPV6_MMTU), 2528 * we almost always ask for an mbuf cluster for simplicity. 2529 * (MHLEN < IPV6_MMTU is almost always true) 2530 */ 2531 #if IPV6_MMTU >= MCLBYTES 2532 # error assumption failed about IPV6_MMTU and MCLBYTES 2533 #endif 2534 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 2535 if (m == NULL) 2536 goto fail; 2537 M_SETFIB(m, rt->rt_fibnum); 2538 maxlen = M_TRAILINGSPACE(m); 2539 maxlen = min(IPV6_MMTU, maxlen); 2540 /* just for safety */ 2541 if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) + 2542 ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) { 2543 goto fail; 2544 } 2545 2546 { 2547 /* get ip6 linklocal address for ifp(my outgoing interface). */ 2548 struct in6_ifaddr *ia; 2549 if ((ia = in6ifa_ifpforlinklocal(ifp, 2550 IN6_IFF_NOTREADY| 2551 IN6_IFF_ANYCAST)) == NULL) 2552 goto fail; 2553 ifp_ll6 = &ia->ia_addr.sin6_addr; 2554 /* XXXRW: reference released prematurely. */ 2555 ifa_free(&ia->ia_ifa); 2556 } 2557 2558 /* get ip6 linklocal address for the router. */ 2559 if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) { 2560 struct sockaddr_in6 *sin6; 2561 sin6 = (struct sockaddr_in6 *)rt->rt_gateway; 2562 router_ll6 = &sin6->sin6_addr; 2563 if (!IN6_IS_ADDR_LINKLOCAL(router_ll6)) 2564 router_ll6 = (struct in6_addr *)NULL; 2565 } else 2566 router_ll6 = (struct in6_addr *)NULL; 2567 2568 /* ip6 */ 2569 ip6 = mtod(m, struct ip6_hdr *); 2570 ip6->ip6_flow = 0; 2571 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2572 ip6->ip6_vfc |= IPV6_VERSION; 2573 /* ip6->ip6_plen will be set later */ 2574 ip6->ip6_nxt = IPPROTO_ICMPV6; 2575 ip6->ip6_hlim = 255; 2576 /* ip6->ip6_src must be linklocal addr for my outgoing if. */ 2577 bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr)); 2578 bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr)); 2579 2580 /* ND Redirect */ 2581 nd_rd = (struct nd_redirect *)(ip6 + 1); 2582 nd_rd->nd_rd_type = ND_REDIRECT; 2583 nd_rd->nd_rd_code = 0; 2584 nd_rd->nd_rd_reserved = 0; 2585 if (rt->rt_flags & RTF_GATEWAY) { 2586 /* 2587 * nd_rd->nd_rd_target must be a link-local address in 2588 * better router cases. 2589 */ 2590 if (!router_ll6) 2591 goto fail; 2592 bcopy(router_ll6, &nd_rd->nd_rd_target, 2593 sizeof(nd_rd->nd_rd_target)); 2594 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2595 sizeof(nd_rd->nd_rd_dst)); 2596 } else { 2597 /* make sure redtgt == reddst */ 2598 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target, 2599 sizeof(nd_rd->nd_rd_target)); 2600 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2601 sizeof(nd_rd->nd_rd_dst)); 2602 } 2603 2604 p = (u_char *)(nd_rd + 1); 2605 2606 if (!router_ll6) 2607 goto nolladdropt; 2608 2609 { 2610 /* target lladdr option */ 2611 int len; 2612 struct nd_opt_hdr *nd_opt; 2613 char *lladdr; 2614 2615 IF_AFDATA_RLOCK(ifp); 2616 ln = nd6_lookup(router_ll6, 0, ifp); 2617 IF_AFDATA_RUNLOCK(ifp); 2618 if (ln == NULL) 2619 goto nolladdropt; 2620 2621 len = sizeof(*nd_opt) + ifp->if_addrlen; 2622 len = (len + 7) & ~7; /* round by 8 */ 2623 /* safety check */ 2624 if (len + (p - (u_char *)ip6) > maxlen) 2625 goto nolladdropt; 2626 2627 if (ln->la_flags & LLE_VALID) { 2628 nd_opt = (struct nd_opt_hdr *)p; 2629 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 2630 nd_opt->nd_opt_len = len >> 3; 2631 lladdr = (char *)(nd_opt + 1); 2632 bcopy(ln->ll_addr, lladdr, ifp->if_addrlen); 2633 p += len; 2634 } 2635 } 2636 nolladdropt: 2637 if (ln != NULL) 2638 LLE_RUNLOCK(ln); 2639 2640 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2641 2642 /* just to be safe */ 2643 #ifdef M_DECRYPTED /*not openbsd*/ 2644 if (m0->m_flags & M_DECRYPTED) 2645 goto noredhdropt; 2646 #endif 2647 if (p - (u_char *)ip6 > maxlen) 2648 goto noredhdropt; 2649 2650 { 2651 /* redirected header option */ 2652 int len; 2653 struct nd_opt_rd_hdr *nd_opt_rh; 2654 2655 /* 2656 * compute the maximum size for icmp6 redirect header option. 2657 * XXX room for auth header? 2658 */ 2659 len = maxlen - (p - (u_char *)ip6); 2660 len &= ~7; 2661 2662 /* This is just for simplicity. */ 2663 if (m0->m_pkthdr.len != m0->m_len) { 2664 if (m0->m_next) { 2665 m_freem(m0->m_next); 2666 m0->m_next = NULL; 2667 } 2668 m0->m_pkthdr.len = m0->m_len; 2669 } 2670 2671 /* 2672 * Redirected header option spec (RFC2461 4.6.3) talks nothing 2673 * about padding/truncate rule for the original IP packet. 2674 * From the discussion on IPv6imp in Feb 1999, 2675 * the consensus was: 2676 * - "attach as much as possible" is the goal 2677 * - pad if not aligned (original size can be guessed by 2678 * original ip6 header) 2679 * Following code adds the padding if it is simple enough, 2680 * and truncates if not. 2681 */ 2682 if (m0->m_next || m0->m_pkthdr.len != m0->m_len) 2683 panic("assumption failed in %s:%d", __FILE__, 2684 __LINE__); 2685 2686 if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) { 2687 /* not enough room, truncate */ 2688 m0->m_pkthdr.len = m0->m_len = len - 2689 sizeof(*nd_opt_rh); 2690 } else { 2691 /* enough room, pad or truncate */ 2692 size_t extra; 2693 2694 extra = m0->m_pkthdr.len % 8; 2695 if (extra) { 2696 /* pad if easy enough, truncate if not */ 2697 if (8 - extra <= M_TRAILINGSPACE(m0)) { 2698 /* pad */ 2699 m0->m_len += (8 - extra); 2700 m0->m_pkthdr.len += (8 - extra); 2701 } else { 2702 /* truncate */ 2703 m0->m_pkthdr.len -= extra; 2704 m0->m_len -= extra; 2705 } 2706 } 2707 len = m0->m_pkthdr.len + sizeof(*nd_opt_rh); 2708 m0->m_pkthdr.len = m0->m_len = len - 2709 sizeof(*nd_opt_rh); 2710 } 2711 2712 nd_opt_rh = (struct nd_opt_rd_hdr *)p; 2713 bzero(nd_opt_rh, sizeof(*nd_opt_rh)); 2714 nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER; 2715 nd_opt_rh->nd_opt_rh_len = len >> 3; 2716 p += sizeof(*nd_opt_rh); 2717 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2718 2719 /* connect m0 to m */ 2720 m_tag_delete_chain(m0, NULL); 2721 m0->m_flags &= ~M_PKTHDR; 2722 m->m_next = m0; 2723 m->m_pkthdr.len = m->m_len + m0->m_len; 2724 m0 = NULL; 2725 } 2726 noredhdropt:; 2727 if (m0) { 2728 m_freem(m0); 2729 m0 = NULL; 2730 } 2731 2732 /* XXX: clear embedded link IDs in the inner header */ 2733 in6_clearscope(&sip6->ip6_src); 2734 in6_clearscope(&sip6->ip6_dst); 2735 in6_clearscope(&nd_rd->nd_rd_target); 2736 in6_clearscope(&nd_rd->nd_rd_dst); 2737 2738 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr)); 2739 2740 nd_rd->nd_rd_cksum = 0; 2741 nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2742 sizeof(*ip6), ntohs(ip6->ip6_plen)); 2743 2744 if (send_sendso_input_hook != NULL) { 2745 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, sizeof(unsigned short), 2746 M_NOWAIT); 2747 if (mtag == NULL) 2748 goto fail; 2749 *(unsigned short *)(mtag + 1) = nd_rd->nd_rd_type; 2750 m_tag_prepend(m, mtag); 2751 } 2752 2753 /* send the packet to outside... */ 2754 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2755 if (outif) { 2756 icmp6_ifstat_inc(outif, ifs6_out_msg); 2757 icmp6_ifstat_inc(outif, ifs6_out_redirect); 2758 } 2759 ICMP6STAT_INC(icp6s_outhist[ND_REDIRECT]); 2760 2761 return; 2762 2763 fail: 2764 if (m) 2765 m_freem(m); 2766 if (m0) 2767 m_freem(m0); 2768 } 2769 2770 /* 2771 * ICMPv6 socket option processing. 2772 */ 2773 int 2774 icmp6_ctloutput(struct socket *so, struct sockopt *sopt) 2775 { 2776 int error = 0; 2777 int optlen; 2778 struct inpcb *inp = sotoinpcb(so); 2779 int level, op, optname; 2780 2781 if (sopt) { 2782 level = sopt->sopt_level; 2783 op = sopt->sopt_dir; 2784 optname = sopt->sopt_name; 2785 optlen = sopt->sopt_valsize; 2786 } else 2787 level = op = optname = optlen = 0; 2788 2789 if (level != IPPROTO_ICMPV6) { 2790 return EINVAL; 2791 } 2792 2793 switch (op) { 2794 case PRCO_SETOPT: 2795 switch (optname) { 2796 case ICMP6_FILTER: 2797 { 2798 struct icmp6_filter ic6f; 2799 2800 if (optlen != sizeof(ic6f)) { 2801 error = EMSGSIZE; 2802 break; 2803 } 2804 error = sooptcopyin(sopt, &ic6f, optlen, optlen); 2805 if (error == 0) { 2806 INP_WLOCK(inp); 2807 *inp->in6p_icmp6filt = ic6f; 2808 INP_WUNLOCK(inp); 2809 } 2810 break; 2811 } 2812 2813 default: 2814 error = ENOPROTOOPT; 2815 break; 2816 } 2817 break; 2818 2819 case PRCO_GETOPT: 2820 switch (optname) { 2821 case ICMP6_FILTER: 2822 { 2823 struct icmp6_filter ic6f; 2824 2825 INP_RLOCK(inp); 2826 ic6f = *inp->in6p_icmp6filt; 2827 INP_RUNLOCK(inp); 2828 error = sooptcopyout(sopt, &ic6f, sizeof(ic6f)); 2829 break; 2830 } 2831 2832 default: 2833 error = ENOPROTOOPT; 2834 break; 2835 } 2836 break; 2837 } 2838 2839 return (error); 2840 } 2841 2842 /* 2843 * Perform rate limit check. 2844 * Returns 0 if it is okay to send the icmp6 packet. 2845 * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate 2846 * limitation. 2847 * 2848 * XXX per-destination/type check necessary? 2849 * 2850 * dst - not used at this moment 2851 * type - not used at this moment 2852 * code - not used at this moment 2853 */ 2854 static int 2855 icmp6_ratelimit(const struct in6_addr *dst, const int type, 2856 const int code) 2857 { 2858 int ret; 2859 2860 ret = 0; /* okay to send */ 2861 2862 /* PPS limit */ 2863 if (!ppsratecheck(&V_icmp6errppslim_last, &V_icmp6errpps_count, 2864 V_icmp6errppslim)) { 2865 /* The packet is subject to rate limit */ 2866 ret++; 2867 } 2868 2869 return ret; 2870 } 2871