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 #include "opt_ipsec.h" 71 72 #include <sys/param.h> 73 #include <sys/domain.h> 74 #include <sys/jail.h> 75 #include <sys/kernel.h> 76 #include <sys/lock.h> 77 #include <sys/malloc.h> 78 #include <sys/mbuf.h> 79 #include <sys/proc.h> 80 #include <sys/protosw.h> 81 #include <sys/signalvar.h> 82 #include <sys/socket.h> 83 #include <sys/socketvar.h> 84 #include <sys/sx.h> 85 #include <sys/syslog.h> 86 #include <sys/systm.h> 87 #include <sys/time.h> 88 89 #include <net/if.h> 90 #include <net/if_var.h> 91 #include <net/if_dl.h> 92 #include <net/if_llatbl.h> 93 #include <net/if_types.h> 94 #include <net/route.h> 95 #include <net/vnet.h> 96 97 #include <netinet/in.h> 98 #include <netinet/in_pcb.h> 99 #include <netinet/in_var.h> 100 #include <netinet/ip6.h> 101 #include <netinet/icmp6.h> 102 #include <netinet/tcp_var.h> 103 104 #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 #ifdef IPSEC 114 #include <netipsec/ipsec.h> 115 #include <netipsec/key.h> 116 #endif 117 118 extern struct domain inet6domain; 119 120 VNET_PCPUSTAT_DEFINE(struct icmp6stat, icmp6stat); 121 VNET_PCPUSTAT_SYSINIT(icmp6stat); 122 123 #ifdef VIMAGE 124 VNET_PCPUSTAT_SYSUNINIT(icmp6stat); 125 #endif /* VIMAGE */ 126 127 VNET_DECLARE(struct inpcbinfo, ripcbinfo); 128 VNET_DECLARE(struct inpcbhead, ripcb); 129 VNET_DECLARE(int, icmp6errppslim); 130 static VNET_DEFINE(int, icmp6errpps_count) = 0; 131 static VNET_DEFINE(struct timeval, icmp6errppslim_last); 132 VNET_DECLARE(int, icmp6_nodeinfo); 133 134 #define V_ripcbinfo VNET(ripcbinfo) 135 #define V_ripcb VNET(ripcb) 136 #define V_icmp6errppslim VNET(icmp6errppslim) 137 #define V_icmp6errpps_count VNET(icmp6errpps_count) 138 #define V_icmp6errppslim_last VNET(icmp6errppslim_last) 139 #define V_icmp6_nodeinfo VNET(icmp6_nodeinfo) 140 141 static void icmp6_errcount(int, int); 142 static int icmp6_rip6_input(struct mbuf **, int); 143 static int icmp6_ratelimit(const struct in6_addr *, const int, const int); 144 static const char *icmp6_redirect_diag(struct in6_addr *, 145 struct in6_addr *, struct in6_addr *); 146 static struct mbuf *ni6_input(struct mbuf *, int); 147 static struct mbuf *ni6_nametodns(const char *, int, int); 148 static int ni6_dnsmatch(const char *, int, const char *, int); 149 static int ni6_addrs(struct icmp6_nodeinfo *, struct mbuf *, 150 struct ifnet **, struct in6_addr *); 151 static int ni6_store_addrs(struct icmp6_nodeinfo *, struct icmp6_nodeinfo *, 152 struct ifnet *, int); 153 static int icmp6_notify_error(struct mbuf **, int, int, int); 154 155 /* 156 * Kernel module interface for updating icmp6stat. The argument is an index 157 * into icmp6stat treated as an array of u_quad_t. While this encodes the 158 * general layout of icmp6stat into the caller, it doesn't encode its 159 * location, so that future changes to add, for example, per-CPU stats 160 * support won't cause binary compatibility problems for kernel modules. 161 */ 162 void 163 kmod_icmp6stat_inc(int statnum) 164 { 165 166 counter_u64_add(VNET(icmp6stat)[statnum], 1); 167 } 168 169 static void 170 icmp6_errcount(int type, int code) 171 { 172 switch (type) { 173 case ICMP6_DST_UNREACH: 174 switch (code) { 175 case ICMP6_DST_UNREACH_NOROUTE: 176 ICMP6STAT_INC(icp6s_odst_unreach_noroute); 177 return; 178 case ICMP6_DST_UNREACH_ADMIN: 179 ICMP6STAT_INC(icp6s_odst_unreach_admin); 180 return; 181 case ICMP6_DST_UNREACH_BEYONDSCOPE: 182 ICMP6STAT_INC(icp6s_odst_unreach_beyondscope); 183 return; 184 case ICMP6_DST_UNREACH_ADDR: 185 ICMP6STAT_INC(icp6s_odst_unreach_addr); 186 return; 187 case ICMP6_DST_UNREACH_NOPORT: 188 ICMP6STAT_INC(icp6s_odst_unreach_noport); 189 return; 190 } 191 break; 192 case ICMP6_PACKET_TOO_BIG: 193 ICMP6STAT_INC(icp6s_opacket_too_big); 194 return; 195 case ICMP6_TIME_EXCEEDED: 196 switch (code) { 197 case ICMP6_TIME_EXCEED_TRANSIT: 198 ICMP6STAT_INC(icp6s_otime_exceed_transit); 199 return; 200 case ICMP6_TIME_EXCEED_REASSEMBLY: 201 ICMP6STAT_INC(icp6s_otime_exceed_reassembly); 202 return; 203 } 204 break; 205 case ICMP6_PARAM_PROB: 206 switch (code) { 207 case ICMP6_PARAMPROB_HEADER: 208 ICMP6STAT_INC(icp6s_oparamprob_header); 209 return; 210 case ICMP6_PARAMPROB_NEXTHEADER: 211 ICMP6STAT_INC(icp6s_oparamprob_nextheader); 212 return; 213 case ICMP6_PARAMPROB_OPTION: 214 ICMP6STAT_INC(icp6s_oparamprob_option); 215 return; 216 } 217 break; 218 case ND_REDIRECT: 219 ICMP6STAT_INC(icp6s_oredirect); 220 return; 221 } 222 ICMP6STAT_INC(icp6s_ounknown); 223 } 224 225 /* 226 * A wrapper function for icmp6_error() necessary when the erroneous packet 227 * may not contain enough scope zone information. 228 */ 229 void 230 icmp6_error2(struct mbuf *m, int type, int code, int param, 231 struct ifnet *ifp) 232 { 233 struct ip6_hdr *ip6; 234 235 if (ifp == NULL) 236 return; 237 238 #ifndef PULLDOWN_TEST 239 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), ); 240 #else 241 if (m->m_len < sizeof(struct ip6_hdr)) { 242 m = m_pullup(m, sizeof(struct ip6_hdr)); 243 if (m == NULL) 244 return; 245 } 246 #endif 247 248 ip6 = mtod(m, struct ip6_hdr *); 249 250 if (in6_setscope(&ip6->ip6_src, ifp, NULL) != 0) 251 return; 252 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0) 253 return; 254 255 icmp6_error(m, type, code, param); 256 } 257 258 /* 259 * Generate an error packet of type error in response to bad IP6 packet. 260 */ 261 void 262 icmp6_error(struct mbuf *m, int type, int code, int param) 263 { 264 struct ip6_hdr *oip6, *nip6; 265 struct icmp6_hdr *icmp6; 266 u_int preplen; 267 int off; 268 int nxt; 269 270 ICMP6STAT_INC(icp6s_error); 271 272 /* count per-type-code statistics */ 273 icmp6_errcount(type, code); 274 275 #ifdef M_DECRYPTED /*not openbsd*/ 276 if (m->m_flags & M_DECRYPTED) { 277 ICMP6STAT_INC(icp6s_canterror); 278 goto freeit; 279 } 280 #endif 281 282 #ifndef PULLDOWN_TEST 283 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), ); 284 #else 285 if (m->m_len < sizeof(struct ip6_hdr)) { 286 m = m_pullup(m, sizeof(struct ip6_hdr)); 287 if (m == NULL) 288 return; 289 } 290 #endif 291 oip6 = mtod(m, struct ip6_hdr *); 292 293 /* 294 * If the destination address of the erroneous packet is a multicast 295 * address, or the packet was sent using link-layer multicast, 296 * we should basically suppress sending an error (RFC 2463, Section 297 * 2.4). 298 * We have two exceptions (the item e.2 in that section): 299 * - the Packet Too Big message can be sent for path MTU discovery. 300 * - the Parameter Problem Message that can be allowed an icmp6 error 301 * in the option type field. This check has been done in 302 * ip6_unknown_opt(), so we can just check the type and code. 303 */ 304 if ((m->m_flags & (M_BCAST|M_MCAST) || 305 IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) && 306 (type != ICMP6_PACKET_TOO_BIG && 307 (type != ICMP6_PARAM_PROB || 308 code != ICMP6_PARAMPROB_OPTION))) 309 goto freeit; 310 311 /* 312 * RFC 2463, 2.4 (e.5): source address check. 313 * XXX: the case of anycast source? 314 */ 315 if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) || 316 IN6_IS_ADDR_MULTICAST(&oip6->ip6_src)) 317 goto freeit; 318 319 /* 320 * If we are about to send ICMPv6 against ICMPv6 error/redirect, 321 * don't do it. 322 */ 323 nxt = -1; 324 off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt); 325 if (off >= 0 && nxt == IPPROTO_ICMPV6) { 326 struct icmp6_hdr *icp; 327 328 #ifndef PULLDOWN_TEST 329 IP6_EXTHDR_CHECK(m, 0, off + sizeof(struct icmp6_hdr), ); 330 icp = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 331 #else 332 IP6_EXTHDR_GET(icp, struct icmp6_hdr *, m, off, 333 sizeof(*icp)); 334 if (icp == NULL) { 335 ICMP6STAT_INC(icp6s_tooshort); 336 return; 337 } 338 #endif 339 if (icp->icmp6_type < ICMP6_ECHO_REQUEST || 340 icp->icmp6_type == ND_REDIRECT) { 341 /* 342 * ICMPv6 error 343 * Special case: for redirect (which is 344 * informational) we must not send icmp6 error. 345 */ 346 ICMP6STAT_INC(icp6s_canterror); 347 goto freeit; 348 } else { 349 /* ICMPv6 informational - send the error */ 350 } 351 } else { 352 /* non-ICMPv6 - send the error */ 353 } 354 355 oip6 = mtod(m, struct ip6_hdr *); /* adjust pointer */ 356 357 /* Finally, do rate limitation check. */ 358 if (icmp6_ratelimit(&oip6->ip6_src, type, code)) { 359 ICMP6STAT_INC(icp6s_toofreq); 360 goto freeit; 361 } 362 363 /* 364 * OK, ICMP6 can be generated. 365 */ 366 367 if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN) 368 m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len); 369 370 preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 371 M_PREPEND(m, preplen, M_NOWAIT); /* FIB is also copied over. */ 372 if (m && m->m_len < preplen) 373 m = m_pullup(m, preplen); 374 if (m == NULL) { 375 nd6log((LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__)); 376 return; 377 } 378 379 nip6 = mtod(m, struct ip6_hdr *); 380 nip6->ip6_src = oip6->ip6_src; 381 nip6->ip6_dst = oip6->ip6_dst; 382 383 in6_clearscope(&oip6->ip6_src); 384 in6_clearscope(&oip6->ip6_dst); 385 386 icmp6 = (struct icmp6_hdr *)(nip6 + 1); 387 icmp6->icmp6_type = type; 388 icmp6->icmp6_code = code; 389 icmp6->icmp6_pptr = htonl((u_int32_t)param); 390 391 /* 392 * icmp6_reflect() is designed to be in the input path. 393 * icmp6_error() can be called from both input and output path, 394 * and if we are in output path rcvif could contain bogus value. 395 * clear m->m_pkthdr.rcvif for safety, we should have enough scope 396 * information in ip header (nip6). 397 */ 398 m->m_pkthdr.rcvif = NULL; 399 400 ICMP6STAT_INC(icp6s_outhist[type]); 401 icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */ 402 403 return; 404 405 freeit: 406 /* 407 * If we can't tell whether or not we can generate ICMP6, free it. 408 */ 409 m_freem(m); 410 } 411 412 /* 413 * Process a received ICMP6 message. 414 */ 415 int 416 icmp6_input(struct mbuf **mp, int *offp, int proto) 417 { 418 struct mbuf *m = *mp, *n; 419 struct ifnet *ifp; 420 struct ip6_hdr *ip6, *nip6; 421 struct icmp6_hdr *icmp6, *nicmp6; 422 int off = *offp; 423 int icmp6len = m->m_pkthdr.len - *offp; 424 int code, sum, noff; 425 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 426 int ip6len, error; 427 428 ifp = m->m_pkthdr.rcvif; 429 430 #ifndef PULLDOWN_TEST 431 IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_hdr), IPPROTO_DONE); 432 /* m might change if M_LOOP. So, call mtod after this */ 433 #endif 434 435 /* 436 * Locate icmp6 structure in mbuf, and check 437 * that not corrupted and of at least minimum length 438 */ 439 440 ip6 = mtod(m, struct ip6_hdr *); 441 ip6len = sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen); 442 if (icmp6len < sizeof(struct icmp6_hdr)) { 443 ICMP6STAT_INC(icp6s_tooshort); 444 goto freeit; 445 } 446 447 /* 448 * Check multicast group membership. 449 * Note: SSM filters are not applied for ICMPv6 traffic. 450 */ 451 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 452 struct in6_multi *inm; 453 454 inm = in6m_lookup(ifp, &ip6->ip6_dst); 455 if (inm == NULL) { 456 IP6STAT_INC(ip6s_notmember); 457 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 458 goto freeit; 459 } 460 } 461 462 /* 463 * calculate the checksum 464 */ 465 #ifndef PULLDOWN_TEST 466 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off); 467 #else 468 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6)); 469 if (icmp6 == NULL) { 470 ICMP6STAT_INC(icp6s_tooshort); 471 return IPPROTO_DONE; 472 } 473 #endif 474 code = icmp6->icmp6_code; 475 476 if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) { 477 nd6log((LOG_ERR, 478 "ICMP6 checksum error(%d|%x) %s\n", 479 icmp6->icmp6_type, sum, 480 ip6_sprintf(ip6bufs, &ip6->ip6_src))); 481 ICMP6STAT_INC(icp6s_checksum); 482 goto freeit; 483 } 484 485 ICMP6STAT_INC(icp6s_inhist[icmp6->icmp6_type]); 486 icmp6_ifstat_inc(ifp, ifs6_in_msg); 487 if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK) 488 icmp6_ifstat_inc(ifp, ifs6_in_error); 489 490 switch (icmp6->icmp6_type) { 491 case ICMP6_DST_UNREACH: 492 icmp6_ifstat_inc(ifp, ifs6_in_dstunreach); 493 switch (code) { 494 case ICMP6_DST_UNREACH_NOROUTE: 495 code = PRC_UNREACH_NET; 496 break; 497 case ICMP6_DST_UNREACH_ADMIN: 498 icmp6_ifstat_inc(ifp, ifs6_in_adminprohib); 499 code = PRC_UNREACH_PROTOCOL; /* is this a good code? */ 500 break; 501 case ICMP6_DST_UNREACH_ADDR: 502 code = PRC_HOSTDEAD; 503 break; 504 case ICMP6_DST_UNREACH_BEYONDSCOPE: 505 /* I mean "source address was incorrect." */ 506 code = PRC_PARAMPROB; 507 break; 508 case ICMP6_DST_UNREACH_NOPORT: 509 code = PRC_UNREACH_PORT; 510 break; 511 default: 512 goto badcode; 513 } 514 goto deliver; 515 break; 516 517 case ICMP6_PACKET_TOO_BIG: 518 icmp6_ifstat_inc(ifp, ifs6_in_pkttoobig); 519 520 /* validation is made in icmp6_mtudisc_update */ 521 522 code = PRC_MSGSIZE; 523 524 /* 525 * Updating the path MTU will be done after examining 526 * intermediate extension headers. 527 */ 528 goto deliver; 529 break; 530 531 case ICMP6_TIME_EXCEEDED: 532 icmp6_ifstat_inc(ifp, ifs6_in_timeexceed); 533 switch (code) { 534 case ICMP6_TIME_EXCEED_TRANSIT: 535 code = PRC_TIMXCEED_INTRANS; 536 break; 537 case ICMP6_TIME_EXCEED_REASSEMBLY: 538 code = PRC_TIMXCEED_REASS; 539 break; 540 default: 541 goto badcode; 542 } 543 goto deliver; 544 break; 545 546 case ICMP6_PARAM_PROB: 547 icmp6_ifstat_inc(ifp, ifs6_in_paramprob); 548 switch (code) { 549 case ICMP6_PARAMPROB_NEXTHEADER: 550 code = PRC_UNREACH_PROTOCOL; 551 break; 552 case ICMP6_PARAMPROB_HEADER: 553 case ICMP6_PARAMPROB_OPTION: 554 code = PRC_PARAMPROB; 555 break; 556 default: 557 goto badcode; 558 } 559 goto deliver; 560 break; 561 562 case ICMP6_ECHO_REQUEST: 563 icmp6_ifstat_inc(ifp, ifs6_in_echo); 564 if (code != 0) 565 goto badcode; 566 if ((n = m_copy(m, 0, M_COPYALL)) == NULL) { 567 /* Give up remote */ 568 break; 569 } 570 if (!M_WRITABLE(n) 571 || n->m_len < off + sizeof(struct icmp6_hdr)) { 572 struct mbuf *n0 = n; 573 int n0len; 574 575 CTASSERT(sizeof(*nip6) + sizeof(*nicmp6) <= MHLEN); 576 n = m_gethdr(M_NOWAIT, n0->m_type); 577 if (n == NULL) { 578 /* Give up remote */ 579 m_freem(n0); 580 break; 581 } 582 583 m_move_pkthdr(n, n0); /* FIB copied. */ 584 n0len = n0->m_pkthdr.len; /* save for use below */ 585 /* 586 * Copy IPv6 and ICMPv6 only. 587 */ 588 nip6 = mtod(n, struct ip6_hdr *); 589 bcopy(ip6, nip6, sizeof(struct ip6_hdr)); 590 nicmp6 = (struct icmp6_hdr *)(nip6 + 1); 591 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr)); 592 noff = sizeof(struct ip6_hdr); 593 /* new mbuf contains only ipv6+icmpv6 headers */ 594 n->m_len = noff + sizeof(struct icmp6_hdr); 595 /* 596 * Adjust mbuf. ip6_plen will be adjusted in 597 * ip6_output(). 598 */ 599 m_adj(n0, off + sizeof(struct icmp6_hdr)); 600 /* recalculate complete packet size */ 601 n->m_pkthdr.len = n0len + (noff - off); 602 n->m_next = n0; 603 } else { 604 nip6 = mtod(n, struct ip6_hdr *); 605 IP6_EXTHDR_GET(nicmp6, struct icmp6_hdr *, n, off, 606 sizeof(*nicmp6)); 607 noff = off; 608 } 609 nicmp6->icmp6_type = ICMP6_ECHO_REPLY; 610 nicmp6->icmp6_code = 0; 611 if (n) { 612 ICMP6STAT_INC(icp6s_reflect); 613 ICMP6STAT_INC(icp6s_outhist[ICMP6_ECHO_REPLY]); 614 icmp6_reflect(n, noff); 615 } 616 break; 617 618 case ICMP6_ECHO_REPLY: 619 icmp6_ifstat_inc(ifp, ifs6_in_echoreply); 620 if (code != 0) 621 goto badcode; 622 break; 623 624 case MLD_LISTENER_QUERY: 625 case MLD_LISTENER_REPORT: 626 case MLD_LISTENER_DONE: 627 case MLDV2_LISTENER_REPORT: 628 /* 629 * Drop MLD traffic which is not link-local, has a hop limit 630 * of greater than 1 hop, or which does not have the 631 * IPv6 HBH Router Alert option. 632 * As IPv6 HBH options are stripped in ip6_input() we must 633 * check an mbuf header flag. 634 * XXX Should we also sanity check that these messages 635 * were directed to a link-local multicast prefix? 636 */ 637 if ((ip6->ip6_hlim != 1) || (m->m_flags & M_RTALERT_MLD) == 0) 638 goto freeit; 639 if (mld_input(m, off, icmp6len) != 0) 640 return (IPPROTO_DONE); 641 /* m stays. */ 642 break; 643 644 case ICMP6_WRUREQUEST: /* ICMP6_FQDN_QUERY */ 645 { 646 enum { WRU, FQDN } mode; 647 648 if (!V_icmp6_nodeinfo) 649 break; 650 651 if (icmp6len == sizeof(struct icmp6_hdr) + 4) 652 mode = WRU; 653 else if (icmp6len >= sizeof(struct icmp6_nodeinfo)) 654 mode = FQDN; 655 else 656 goto badlen; 657 658 if (mode == FQDN) { 659 #ifndef PULLDOWN_TEST 660 IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_nodeinfo), 661 IPPROTO_DONE); 662 #endif 663 n = m_copy(m, 0, M_COPYALL); 664 if (n) 665 n = ni6_input(n, off); 666 /* XXX meaningless if n == NULL */ 667 noff = sizeof(struct ip6_hdr); 668 } else { 669 struct prison *pr; 670 u_char *p; 671 int maxhlen, hlen; 672 673 /* 674 * XXX: this combination of flags is pointless, 675 * but should we keep this for compatibility? 676 */ 677 if ((V_icmp6_nodeinfo & 5) != 5) 678 break; 679 680 if (code != 0) 681 goto badcode; 682 683 CTASSERT(sizeof(*nip6) + sizeof(*nicmp6) + 4 <= MHLEN); 684 n = m_gethdr(M_NOWAIT, m->m_type); 685 if (n == NULL) { 686 /* Give up remote */ 687 break; 688 } 689 if (!m_dup_pkthdr(n, m, M_NOWAIT)) { 690 /* 691 * Previous code did a blind M_COPY_PKTHDR 692 * and said "just for rcvif". If true, then 693 * we could tolerate the dup failing (due to 694 * the deep copy of the tag chain). For now 695 * be conservative and just fail. 696 */ 697 m_free(n); 698 n = NULL; 699 } 700 maxhlen = M_TRAILINGSPACE(n) - 701 (sizeof(*nip6) + sizeof(*nicmp6) + 4); 702 pr = curthread->td_ucred->cr_prison; 703 mtx_lock(&pr->pr_mtx); 704 hlen = strlen(pr->pr_hostname); 705 if (maxhlen > hlen) 706 maxhlen = hlen; 707 /* 708 * Copy IPv6 and ICMPv6 only. 709 */ 710 nip6 = mtod(n, struct ip6_hdr *); 711 bcopy(ip6, nip6, sizeof(struct ip6_hdr)); 712 nicmp6 = (struct icmp6_hdr *)(nip6 + 1); 713 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr)); 714 p = (u_char *)(nicmp6 + 1); 715 bzero(p, 4); 716 /* meaningless TTL */ 717 bcopy(pr->pr_hostname, p + 4, maxhlen); 718 mtx_unlock(&pr->pr_mtx); 719 noff = sizeof(struct ip6_hdr); 720 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + 721 sizeof(struct icmp6_hdr) + 4 + maxhlen; 722 nicmp6->icmp6_type = ICMP6_WRUREPLY; 723 nicmp6->icmp6_code = 0; 724 } 725 if (n) { 726 ICMP6STAT_INC(icp6s_reflect); 727 ICMP6STAT_INC(icp6s_outhist[ICMP6_WRUREPLY]); 728 icmp6_reflect(n, noff); 729 } 730 break; 731 } 732 733 case ICMP6_WRUREPLY: 734 if (code != 0) 735 goto badcode; 736 break; 737 738 case ND_ROUTER_SOLICIT: 739 icmp6_ifstat_inc(ifp, ifs6_in_routersolicit); 740 if (code != 0) 741 goto badcode; 742 if (icmp6len < sizeof(struct nd_router_solicit)) 743 goto badlen; 744 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) { 745 /* give up local */ 746 747 /* Send incoming SeND packet to user space. */ 748 if (send_sendso_input_hook != NULL) { 749 IP6_EXTHDR_CHECK(m, off, 750 icmp6len, IPPROTO_DONE); 751 error = send_sendso_input_hook(m, ifp, 752 SND_IN, ip6len); 753 /* -1 == no app on SEND socket */ 754 if (error == 0) 755 return (IPPROTO_DONE); 756 nd6_rs_input(m, off, icmp6len); 757 } else 758 nd6_rs_input(m, off, icmp6len); 759 m = NULL; 760 goto freeit; 761 } 762 if (send_sendso_input_hook != NULL) { 763 IP6_EXTHDR_CHECK(n, off, 764 icmp6len, IPPROTO_DONE); 765 error = send_sendso_input_hook(n, ifp, 766 SND_IN, ip6len); 767 if (error == 0) 768 goto freeit; 769 /* -1 == no app on SEND socket */ 770 nd6_rs_input(n, off, icmp6len); 771 } else 772 nd6_rs_input(n, off, icmp6len); 773 /* m stays. */ 774 break; 775 776 case ND_ROUTER_ADVERT: 777 icmp6_ifstat_inc(ifp, ifs6_in_routeradvert); 778 if (code != 0) 779 goto badcode; 780 if (icmp6len < sizeof(struct nd_router_advert)) 781 goto badlen; 782 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) { 783 784 /* Send incoming SeND-protected/ND packet to user space. */ 785 if (send_sendso_input_hook != NULL) { 786 error = send_sendso_input_hook(m, ifp, 787 SND_IN, ip6len); 788 if (error == 0) 789 return (IPPROTO_DONE); 790 nd6_ra_input(m, off, icmp6len); 791 } else 792 nd6_ra_input(m, off, icmp6len); 793 m = NULL; 794 goto freeit; 795 } 796 if (send_sendso_input_hook != NULL) { 797 error = send_sendso_input_hook(n, ifp, 798 SND_IN, ip6len); 799 if (error == 0) 800 goto freeit; 801 nd6_ra_input(n, off, icmp6len); 802 } else 803 nd6_ra_input(n, off, icmp6len); 804 /* m stays. */ 805 break; 806 807 case ND_NEIGHBOR_SOLICIT: 808 icmp6_ifstat_inc(ifp, ifs6_in_neighborsolicit); 809 if (code != 0) 810 goto badcode; 811 if (icmp6len < sizeof(struct nd_neighbor_solicit)) 812 goto badlen; 813 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) { 814 if (send_sendso_input_hook != NULL) { 815 error = send_sendso_input_hook(m, ifp, 816 SND_IN, ip6len); 817 if (error == 0) 818 return (IPPROTO_DONE); 819 nd6_ns_input(m, off, icmp6len); 820 } else 821 nd6_ns_input(m, off, icmp6len); 822 m = NULL; 823 goto freeit; 824 } 825 if (send_sendso_input_hook != NULL) { 826 error = send_sendso_input_hook(n, ifp, 827 SND_IN, ip6len); 828 if (error == 0) 829 goto freeit; 830 nd6_ns_input(n, off, icmp6len); 831 } else 832 nd6_ns_input(n, off, icmp6len); 833 /* m stays. */ 834 break; 835 836 case ND_NEIGHBOR_ADVERT: 837 icmp6_ifstat_inc(ifp, ifs6_in_neighboradvert); 838 if (code != 0) 839 goto badcode; 840 if (icmp6len < sizeof(struct nd_neighbor_advert)) 841 goto badlen; 842 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) { 843 844 /* Send incoming SeND-protected/ND packet to user space. */ 845 if (send_sendso_input_hook != NULL) { 846 error = send_sendso_input_hook(m, ifp, 847 SND_IN, ip6len); 848 if (error == 0) 849 return (IPPROTO_DONE); 850 nd6_na_input(m, off, icmp6len); 851 } else 852 nd6_na_input(m, off, icmp6len); 853 m = NULL; 854 goto freeit; 855 } 856 if (send_sendso_input_hook != NULL) { 857 error = send_sendso_input_hook(n, ifp, 858 SND_IN, ip6len); 859 if (error == 0) 860 goto freeit; 861 nd6_na_input(n, off, icmp6len); 862 } else 863 nd6_na_input(n, off, icmp6len); 864 /* m stays. */ 865 break; 866 867 case ND_REDIRECT: 868 icmp6_ifstat_inc(ifp, ifs6_in_redirect); 869 if (code != 0) 870 goto badcode; 871 if (icmp6len < sizeof(struct nd_redirect)) 872 goto badlen; 873 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) { 874 if (send_sendso_input_hook != NULL) { 875 error = send_sendso_input_hook(m, ifp, 876 SND_IN, ip6len); 877 if (error == 0) 878 return (IPPROTO_DONE); 879 icmp6_redirect_input(m, off); 880 } else 881 icmp6_redirect_input(m, off); 882 m = NULL; 883 goto freeit; 884 } 885 if (send_sendso_input_hook != NULL) { 886 error = send_sendso_input_hook(n, ifp, 887 SND_IN, ip6len); 888 if (error == 0) 889 goto freeit; 890 icmp6_redirect_input(n, off); 891 } else 892 icmp6_redirect_input(n, off); 893 /* m stays. */ 894 break; 895 896 case ICMP6_ROUTER_RENUMBERING: 897 if (code != ICMP6_ROUTER_RENUMBERING_COMMAND && 898 code != ICMP6_ROUTER_RENUMBERING_RESULT) 899 goto badcode; 900 if (icmp6len < sizeof(struct icmp6_router_renum)) 901 goto badlen; 902 break; 903 904 default: 905 nd6log((LOG_DEBUG, 906 "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n", 907 icmp6->icmp6_type, ip6_sprintf(ip6bufs, &ip6->ip6_src), 908 ip6_sprintf(ip6bufd, &ip6->ip6_dst), 909 ifp ? ifp->if_index : 0)); 910 if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) { 911 /* ICMPv6 error: MUST deliver it by spec... */ 912 code = PRC_NCMDS; 913 /* deliver */ 914 } else { 915 /* ICMPv6 informational: MUST not deliver */ 916 break; 917 } 918 deliver: 919 if (icmp6_notify_error(&m, off, icmp6len, code) != 0) { 920 /* In this case, m should've been freed. */ 921 return (IPPROTO_DONE); 922 } 923 break; 924 925 badcode: 926 ICMP6STAT_INC(icp6s_badcode); 927 break; 928 929 badlen: 930 ICMP6STAT_INC(icp6s_badlen); 931 break; 932 } 933 934 /* deliver the packet to appropriate sockets */ 935 icmp6_rip6_input(&m, *offp); 936 937 return IPPROTO_DONE; 938 939 freeit: 940 m_freem(m); 941 return IPPROTO_DONE; 942 } 943 944 static int 945 icmp6_notify_error(struct mbuf **mp, int off, int icmp6len, int code) 946 { 947 struct mbuf *m = *mp; 948 struct icmp6_hdr *icmp6; 949 struct ip6_hdr *eip6; 950 u_int32_t notifymtu; 951 struct sockaddr_in6 icmp6src, icmp6dst; 952 953 if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) { 954 ICMP6STAT_INC(icp6s_tooshort); 955 goto freeit; 956 } 957 #ifndef PULLDOWN_TEST 958 IP6_EXTHDR_CHECK(m, off, 959 sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr), -1); 960 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 961 #else 962 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, 963 sizeof(*icmp6) + sizeof(struct ip6_hdr)); 964 if (icmp6 == NULL) { 965 ICMP6STAT_INC(icp6s_tooshort); 966 return (-1); 967 } 968 #endif 969 eip6 = (struct ip6_hdr *)(icmp6 + 1); 970 971 /* Detect the upper level protocol */ 972 { 973 void (*ctlfunc)(int, struct sockaddr *, void *); 974 u_int8_t nxt = eip6->ip6_nxt; 975 int eoff = off + sizeof(struct icmp6_hdr) + 976 sizeof(struct ip6_hdr); 977 struct ip6ctlparam ip6cp; 978 struct in6_addr *finaldst = NULL; 979 int icmp6type = icmp6->icmp6_type; 980 struct ip6_frag *fh; 981 struct ip6_rthdr *rth; 982 struct ip6_rthdr0 *rth0; 983 int rthlen; 984 985 while (1) { /* XXX: should avoid infinite loop explicitly? */ 986 struct ip6_ext *eh; 987 988 switch (nxt) { 989 case IPPROTO_HOPOPTS: 990 case IPPROTO_DSTOPTS: 991 case IPPROTO_AH: 992 #ifndef PULLDOWN_TEST 993 IP6_EXTHDR_CHECK(m, 0, 994 eoff + sizeof(struct ip6_ext), -1); 995 eh = (struct ip6_ext *)(mtod(m, caddr_t) + eoff); 996 #else 997 IP6_EXTHDR_GET(eh, struct ip6_ext *, m, 998 eoff, sizeof(*eh)); 999 if (eh == NULL) { 1000 ICMP6STAT_INC(icp6s_tooshort); 1001 return (-1); 1002 } 1003 #endif 1004 1005 if (nxt == IPPROTO_AH) 1006 eoff += (eh->ip6e_len + 2) << 2; 1007 else 1008 eoff += (eh->ip6e_len + 1) << 3; 1009 nxt = eh->ip6e_nxt; 1010 break; 1011 case IPPROTO_ROUTING: 1012 /* 1013 * When the erroneous packet contains a 1014 * routing header, we should examine the 1015 * header to determine the final destination. 1016 * Otherwise, we can't properly update 1017 * information that depends on the final 1018 * destination (e.g. path MTU). 1019 */ 1020 #ifndef PULLDOWN_TEST 1021 IP6_EXTHDR_CHECK(m, 0, eoff + sizeof(*rth), -1); 1022 rth = (struct ip6_rthdr *) 1023 (mtod(m, caddr_t) + eoff); 1024 #else 1025 IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m, 1026 eoff, sizeof(*rth)); 1027 if (rth == NULL) { 1028 ICMP6STAT_INC(icp6s_tooshort); 1029 return (-1); 1030 } 1031 #endif 1032 rthlen = (rth->ip6r_len + 1) << 3; 1033 /* 1034 * XXX: currently there is no 1035 * officially defined type other 1036 * than type-0. 1037 * Note that if the segment left field 1038 * is 0, all intermediate hops must 1039 * have been passed. 1040 */ 1041 if (rth->ip6r_segleft && 1042 rth->ip6r_type == IPV6_RTHDR_TYPE_0) { 1043 int hops; 1044 1045 #ifndef PULLDOWN_TEST 1046 IP6_EXTHDR_CHECK(m, 0, eoff + rthlen, -1); 1047 rth0 = (struct ip6_rthdr0 *) 1048 (mtod(m, caddr_t) + eoff); 1049 #else 1050 IP6_EXTHDR_GET(rth0, 1051 struct ip6_rthdr0 *, m, 1052 eoff, rthlen); 1053 if (rth0 == NULL) { 1054 ICMP6STAT_INC(icp6s_tooshort); 1055 return (-1); 1056 } 1057 #endif 1058 /* just ignore a bogus header */ 1059 if ((rth0->ip6r0_len % 2) == 0 && 1060 (hops = rth0->ip6r0_len/2)) 1061 finaldst = (struct in6_addr *)(rth0 + 1) + (hops - 1); 1062 } 1063 eoff += rthlen; 1064 nxt = rth->ip6r_nxt; 1065 break; 1066 case IPPROTO_FRAGMENT: 1067 #ifndef PULLDOWN_TEST 1068 IP6_EXTHDR_CHECK(m, 0, eoff + 1069 sizeof(struct ip6_frag), -1); 1070 fh = (struct ip6_frag *)(mtod(m, caddr_t) + 1071 eoff); 1072 #else 1073 IP6_EXTHDR_GET(fh, struct ip6_frag *, m, 1074 eoff, sizeof(*fh)); 1075 if (fh == NULL) { 1076 ICMP6STAT_INC(icp6s_tooshort); 1077 return (-1); 1078 } 1079 #endif 1080 /* 1081 * Data after a fragment header is meaningless 1082 * unless it is the first fragment, but 1083 * we'll go to the notify label for path MTU 1084 * discovery. 1085 */ 1086 if (fh->ip6f_offlg & IP6F_OFF_MASK) 1087 goto notify; 1088 1089 eoff += sizeof(struct ip6_frag); 1090 nxt = fh->ip6f_nxt; 1091 break; 1092 default: 1093 /* 1094 * This case includes ESP and the No Next 1095 * Header. In such cases going to the notify 1096 * label does not have any meaning 1097 * (i.e. ctlfunc will be NULL), but we go 1098 * anyway since we might have to update 1099 * path MTU information. 1100 */ 1101 goto notify; 1102 } 1103 } 1104 notify: 1105 #ifndef PULLDOWN_TEST 1106 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 1107 #else 1108 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, 1109 sizeof(*icmp6) + sizeof(struct ip6_hdr)); 1110 if (icmp6 == NULL) { 1111 ICMP6STAT_INC(icp6s_tooshort); 1112 return (-1); 1113 } 1114 #endif 1115 1116 /* 1117 * retrieve parameters from the inner IPv6 header, and convert 1118 * them into sockaddr structures. 1119 * XXX: there is no guarantee that the source or destination 1120 * addresses of the inner packet are in the same scope as 1121 * the addresses of the icmp packet. But there is no other 1122 * way to determine the zone. 1123 */ 1124 eip6 = (struct ip6_hdr *)(icmp6 + 1); 1125 1126 bzero(&icmp6dst, sizeof(icmp6dst)); 1127 icmp6dst.sin6_len = sizeof(struct sockaddr_in6); 1128 icmp6dst.sin6_family = AF_INET6; 1129 if (finaldst == NULL) 1130 icmp6dst.sin6_addr = eip6->ip6_dst; 1131 else 1132 icmp6dst.sin6_addr = *finaldst; 1133 if (in6_setscope(&icmp6dst.sin6_addr, m->m_pkthdr.rcvif, NULL)) 1134 goto freeit; 1135 bzero(&icmp6src, sizeof(icmp6src)); 1136 icmp6src.sin6_len = sizeof(struct sockaddr_in6); 1137 icmp6src.sin6_family = AF_INET6; 1138 icmp6src.sin6_addr = eip6->ip6_src; 1139 if (in6_setscope(&icmp6src.sin6_addr, m->m_pkthdr.rcvif, NULL)) 1140 goto freeit; 1141 icmp6src.sin6_flowinfo = 1142 (eip6->ip6_flow & IPV6_FLOWLABEL_MASK); 1143 1144 if (finaldst == NULL) 1145 finaldst = &eip6->ip6_dst; 1146 ip6cp.ip6c_m = m; 1147 ip6cp.ip6c_icmp6 = icmp6; 1148 ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1); 1149 ip6cp.ip6c_off = eoff; 1150 ip6cp.ip6c_finaldst = finaldst; 1151 ip6cp.ip6c_src = &icmp6src; 1152 ip6cp.ip6c_nxt = nxt; 1153 1154 if (icmp6type == ICMP6_PACKET_TOO_BIG) { 1155 notifymtu = ntohl(icmp6->icmp6_mtu); 1156 ip6cp.ip6c_cmdarg = (void *)¬ifymtu; 1157 icmp6_mtudisc_update(&ip6cp, 1); /*XXX*/ 1158 } 1159 1160 ctlfunc = (void (*)(int, struct sockaddr *, void *)) 1161 (inet6sw[ip6_protox[nxt]].pr_ctlinput); 1162 if (ctlfunc) { 1163 (void) (*ctlfunc)(code, (struct sockaddr *)&icmp6dst, 1164 &ip6cp); 1165 } 1166 } 1167 *mp = m; 1168 return (0); 1169 1170 freeit: 1171 m_freem(m); 1172 return (-1); 1173 } 1174 1175 void 1176 icmp6_mtudisc_update(struct ip6ctlparam *ip6cp, int validated) 1177 { 1178 struct in6_addr *dst = ip6cp->ip6c_finaldst; 1179 struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6; 1180 struct mbuf *m = ip6cp->ip6c_m; /* will be necessary for scope issue */ 1181 u_int mtu = ntohl(icmp6->icmp6_mtu); 1182 struct in_conninfo inc; 1183 1184 #if 0 1185 /* 1186 * RFC2460 section 5, last paragraph. 1187 * even though minimum link MTU for IPv6 is IPV6_MMTU, 1188 * we may see ICMPv6 too big with mtu < IPV6_MMTU 1189 * due to packet translator in the middle. 1190 * see ip6_output() and ip6_getpmtu() "alwaysfrag" case for 1191 * special handling. 1192 */ 1193 if (mtu < IPV6_MMTU) 1194 return; 1195 #endif 1196 1197 /* 1198 * we reject ICMPv6 too big with abnormally small value. 1199 * XXX what is the good definition of "abnormally small"? 1200 */ 1201 if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8) 1202 return; 1203 1204 if (!validated) 1205 return; 1206 1207 /* 1208 * In case the suggested mtu is less than IPV6_MMTU, we 1209 * only need to remember that it was for above mentioned 1210 * "alwaysfrag" case. 1211 * Try to be as close to the spec as possible. 1212 */ 1213 if (mtu < IPV6_MMTU) 1214 mtu = IPV6_MMTU - 8; 1215 1216 bzero(&inc, sizeof(inc)); 1217 inc.inc_fibnum = M_GETFIB(m); 1218 inc.inc_flags |= INC_ISIPV6; 1219 inc.inc6_faddr = *dst; 1220 if (in6_setscope(&inc.inc6_faddr, m->m_pkthdr.rcvif, NULL)) 1221 return; 1222 1223 if (mtu < tcp_maxmtu6(&inc, NULL)) { 1224 tcp_hc_updatemtu(&inc, mtu); 1225 ICMP6STAT_INC(icp6s_pmtuchg); 1226 } 1227 } 1228 1229 /* 1230 * Process a Node Information Query packet, based on 1231 * draft-ietf-ipngwg-icmp-name-lookups-07. 1232 * 1233 * Spec incompatibilities: 1234 * - IPv6 Subject address handling 1235 * - IPv4 Subject address handling support missing 1236 * - Proxy reply (answer even if it's not for me) 1237 * - joins NI group address at in6_ifattach() time only, does not cope 1238 * with hostname changes by sethostname(3) 1239 */ 1240 static struct mbuf * 1241 ni6_input(struct mbuf *m, int off) 1242 { 1243 struct icmp6_nodeinfo *ni6, *nni6; 1244 struct mbuf *n = NULL; 1245 struct prison *pr; 1246 u_int16_t qtype; 1247 int subjlen; 1248 int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); 1249 struct ni_reply_fqdn *fqdn; 1250 int addrs; /* for NI_QTYPE_NODEADDR */ 1251 struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */ 1252 struct in6_addr in6_subj; /* subject address */ 1253 struct ip6_hdr *ip6; 1254 int oldfqdn = 0; /* if 1, return pascal string (03 draft) */ 1255 char *subj = NULL; 1256 struct in6_ifaddr *ia6 = NULL; 1257 1258 ip6 = mtod(m, struct ip6_hdr *); 1259 #ifndef PULLDOWN_TEST 1260 ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off); 1261 #else 1262 IP6_EXTHDR_GET(ni6, struct icmp6_nodeinfo *, m, off, sizeof(*ni6)); 1263 if (ni6 == NULL) { 1264 /* m is already reclaimed */ 1265 return (NULL); 1266 } 1267 #endif 1268 1269 /* 1270 * Validate IPv6 source address. 1271 * The default configuration MUST be to refuse answering queries from 1272 * global-scope addresses according to RFC4602. 1273 * Notes: 1274 * - it's not very clear what "refuse" means; this implementation 1275 * simply drops it. 1276 * - it's not very easy to identify global-scope (unicast) addresses 1277 * since there are many prefixes for them. It should be safer 1278 * and in practice sufficient to check "all" but loopback and 1279 * link-local (note that site-local unicast was deprecated and 1280 * ULA is defined as global scope-wise) 1281 */ 1282 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_GLOBALOK) == 0 && 1283 !IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) && 1284 !IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) 1285 goto bad; 1286 1287 /* 1288 * Validate IPv6 destination address. 1289 * 1290 * The Responder must discard the Query without further processing 1291 * unless it is one of the Responder's unicast or anycast addresses, or 1292 * a link-local scope multicast address which the Responder has joined. 1293 * [RFC4602, Section 5.] 1294 */ 1295 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 1296 if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst)) 1297 goto bad; 1298 /* else it's a link-local multicast, fine */ 1299 } else { /* unicast or anycast */ 1300 ia6 = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */); 1301 if (ia6 == NULL) 1302 goto bad; /* XXX impossible */ 1303 1304 if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) && 1305 !(V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK)) { 1306 ifa_free(&ia6->ia_ifa); 1307 nd6log((LOG_DEBUG, "ni6_input: ignore node info to " 1308 "a temporary address in %s:%d", 1309 __FILE__, __LINE__)); 1310 goto bad; 1311 } 1312 ifa_free(&ia6->ia_ifa); 1313 } 1314 1315 /* validate query Subject field. */ 1316 qtype = ntohs(ni6->ni_qtype); 1317 subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo); 1318 switch (qtype) { 1319 case NI_QTYPE_NOOP: 1320 case NI_QTYPE_SUPTYPES: 1321 /* 07 draft */ 1322 if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0) 1323 break; 1324 /* FALLTHROUGH */ 1325 case NI_QTYPE_FQDN: 1326 case NI_QTYPE_NODEADDR: 1327 case NI_QTYPE_IPV4ADDR: 1328 switch (ni6->ni_code) { 1329 case ICMP6_NI_SUBJ_IPV6: 1330 #if ICMP6_NI_SUBJ_IPV6 != 0 1331 case 0: 1332 #endif 1333 /* 1334 * backward compatibility - try to accept 03 draft 1335 * format, where no Subject is present. 1336 */ 1337 if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 && 1338 subjlen == 0) { 1339 oldfqdn++; 1340 break; 1341 } 1342 #if ICMP6_NI_SUBJ_IPV6 != 0 1343 if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6) 1344 goto bad; 1345 #endif 1346 1347 if (subjlen != sizeof(struct in6_addr)) 1348 goto bad; 1349 1350 /* 1351 * Validate Subject address. 1352 * 1353 * Not sure what exactly "address belongs to the node" 1354 * means in the spec, is it just unicast, or what? 1355 * 1356 * At this moment we consider Subject address as 1357 * "belong to the node" if the Subject address equals 1358 * to the IPv6 destination address; validation for 1359 * IPv6 destination address should have done enough 1360 * check for us. 1361 * 1362 * We do not do proxy at this moment. 1363 */ 1364 /* m_pulldown instead of copy? */ 1365 m_copydata(m, off + sizeof(struct icmp6_nodeinfo), 1366 subjlen, (caddr_t)&in6_subj); 1367 if (in6_setscope(&in6_subj, m->m_pkthdr.rcvif, NULL)) 1368 goto bad; 1369 1370 subj = (char *)&in6_subj; 1371 if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &in6_subj)) 1372 break; 1373 1374 /* 1375 * XXX if we are to allow other cases, we should really 1376 * be careful about scope here. 1377 * basically, we should disallow queries toward IPv6 1378 * destination X with subject Y, 1379 * if scope(X) > scope(Y). 1380 * if we allow scope(X) > scope(Y), it will result in 1381 * information leakage across scope boundary. 1382 */ 1383 goto bad; 1384 1385 case ICMP6_NI_SUBJ_FQDN: 1386 /* 1387 * Validate Subject name with gethostname(3). 1388 * 1389 * The behavior may need some debate, since: 1390 * - we are not sure if the node has FQDN as 1391 * hostname (returned by gethostname(3)). 1392 * - the code does wildcard match for truncated names. 1393 * however, we are not sure if we want to perform 1394 * wildcard match, if gethostname(3) side has 1395 * truncated hostname. 1396 */ 1397 pr = curthread->td_ucred->cr_prison; 1398 mtx_lock(&pr->pr_mtx); 1399 n = ni6_nametodns(pr->pr_hostname, 1400 strlen(pr->pr_hostname), 0); 1401 mtx_unlock(&pr->pr_mtx); 1402 if (!n || n->m_next || n->m_len == 0) 1403 goto bad; 1404 IP6_EXTHDR_GET(subj, char *, m, 1405 off + sizeof(struct icmp6_nodeinfo), subjlen); 1406 if (subj == NULL) 1407 goto bad; 1408 if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *), 1409 n->m_len)) { 1410 goto bad; 1411 } 1412 m_freem(n); 1413 n = NULL; 1414 break; 1415 1416 case ICMP6_NI_SUBJ_IPV4: /* XXX: to be implemented? */ 1417 default: 1418 goto bad; 1419 } 1420 break; 1421 } 1422 1423 /* refuse based on configuration. XXX ICMP6_NI_REFUSED? */ 1424 switch (qtype) { 1425 case NI_QTYPE_FQDN: 1426 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_FQDNOK) == 0) 1427 goto bad; 1428 break; 1429 case NI_QTYPE_NODEADDR: 1430 case NI_QTYPE_IPV4ADDR: 1431 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_NODEADDROK) == 0) 1432 goto bad; 1433 break; 1434 } 1435 1436 /* guess reply length */ 1437 switch (qtype) { 1438 case NI_QTYPE_NOOP: 1439 break; /* no reply data */ 1440 case NI_QTYPE_SUPTYPES: 1441 replylen += sizeof(u_int32_t); 1442 break; 1443 case NI_QTYPE_FQDN: 1444 /* XXX will append an mbuf */ 1445 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); 1446 break; 1447 case NI_QTYPE_NODEADDR: 1448 addrs = ni6_addrs(ni6, m, &ifp, (struct in6_addr *)subj); 1449 if ((replylen += addrs * (sizeof(struct in6_addr) + 1450 sizeof(u_int32_t))) > MCLBYTES) 1451 replylen = MCLBYTES; /* XXX: will truncate pkt later */ 1452 break; 1453 case NI_QTYPE_IPV4ADDR: 1454 /* unsupported - should respond with unknown Qtype? */ 1455 break; 1456 default: 1457 /* 1458 * XXX: We must return a reply with the ICMP6 code 1459 * `unknown Qtype' in this case. However we regard the case 1460 * as an FQDN query for backward compatibility. 1461 * Older versions set a random value to this field, 1462 * so it rarely varies in the defined qtypes. 1463 * But the mechanism is not reliable... 1464 * maybe we should obsolete older versions. 1465 */ 1466 qtype = NI_QTYPE_FQDN; 1467 /* XXX will append an mbuf */ 1468 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); 1469 oldfqdn++; 1470 break; 1471 } 1472 1473 /* Allocate an mbuf to reply. */ 1474 if (replylen > MCLBYTES) { 1475 /* 1476 * XXX: should we try to allocate more? But MCLBYTES 1477 * is probably much larger than IPV6_MMTU... 1478 */ 1479 goto bad; 1480 } 1481 if (replylen > MHLEN) 1482 n = m_getcl(M_NOWAIT, m->m_type, M_PKTHDR); 1483 else 1484 n = m_gethdr(M_NOWAIT, m->m_type); 1485 if (n == NULL) { 1486 m_freem(m); 1487 return (NULL); 1488 } 1489 m_move_pkthdr(n, m); /* just for recvif and FIB */ 1490 n->m_pkthdr.len = n->m_len = replylen; 1491 1492 /* copy mbuf header and IPv6 + Node Information base headers */ 1493 bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr)); 1494 nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1); 1495 bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo)); 1496 1497 /* qtype dependent procedure */ 1498 switch (qtype) { 1499 case NI_QTYPE_NOOP: 1500 nni6->ni_code = ICMP6_NI_SUCCESS; 1501 nni6->ni_flags = 0; 1502 break; 1503 case NI_QTYPE_SUPTYPES: 1504 { 1505 u_int32_t v; 1506 nni6->ni_code = ICMP6_NI_SUCCESS; 1507 nni6->ni_flags = htons(0x0000); /* raw bitmap */ 1508 /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */ 1509 v = (u_int32_t)htonl(0x0000000f); 1510 bcopy(&v, nni6 + 1, sizeof(u_int32_t)); 1511 break; 1512 } 1513 case NI_QTYPE_FQDN: 1514 nni6->ni_code = ICMP6_NI_SUCCESS; 1515 fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) + 1516 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo)); 1517 nni6->ni_flags = 0; /* XXX: meaningless TTL */ 1518 fqdn->ni_fqdn_ttl = 0; /* ditto. */ 1519 /* 1520 * XXX do we really have FQDN in hostname? 1521 */ 1522 pr = curthread->td_ucred->cr_prison; 1523 mtx_lock(&pr->pr_mtx); 1524 n->m_next = ni6_nametodns(pr->pr_hostname, 1525 strlen(pr->pr_hostname), oldfqdn); 1526 mtx_unlock(&pr->pr_mtx); 1527 if (n->m_next == NULL) 1528 goto bad; 1529 /* XXX we assume that n->m_next is not a chain */ 1530 if (n->m_next->m_next != NULL) 1531 goto bad; 1532 n->m_pkthdr.len += n->m_next->m_len; 1533 break; 1534 case NI_QTYPE_NODEADDR: 1535 { 1536 int lenlim, copied; 1537 1538 nni6->ni_code = ICMP6_NI_SUCCESS; 1539 n->m_pkthdr.len = n->m_len = 1540 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); 1541 lenlim = M_TRAILINGSPACE(n); 1542 copied = ni6_store_addrs(ni6, nni6, ifp, lenlim); 1543 /* XXX: reset mbuf length */ 1544 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + 1545 sizeof(struct icmp6_nodeinfo) + copied; 1546 break; 1547 } 1548 default: 1549 break; /* XXX impossible! */ 1550 } 1551 1552 nni6->ni_type = ICMP6_NI_REPLY; 1553 m_freem(m); 1554 return (n); 1555 1556 bad: 1557 m_freem(m); 1558 if (n) 1559 m_freem(n); 1560 return (NULL); 1561 } 1562 1563 /* 1564 * make a mbuf with DNS-encoded string. no compression support. 1565 * 1566 * XXX names with less than 2 dots (like "foo" or "foo.section") will be 1567 * treated as truncated name (two \0 at the end). this is a wild guess. 1568 * 1569 * old - return pascal string if non-zero 1570 */ 1571 static struct mbuf * 1572 ni6_nametodns(const char *name, int namelen, int old) 1573 { 1574 struct mbuf *m; 1575 char *cp, *ep; 1576 const char *p, *q; 1577 int i, len, nterm; 1578 1579 if (old) 1580 len = namelen + 1; 1581 else 1582 len = MCLBYTES; 1583 1584 /* Because MAXHOSTNAMELEN is usually 256, we use cluster mbuf. */ 1585 if (len > MLEN) 1586 m = m_getcl(M_NOWAIT, MT_DATA, 0); 1587 else 1588 m = m_get(M_NOWAIT, MT_DATA); 1589 if (m == NULL) 1590 goto fail; 1591 1592 if (old) { 1593 m->m_len = len; 1594 *mtod(m, char *) = namelen; 1595 bcopy(name, mtod(m, char *) + 1, namelen); 1596 return m; 1597 } else { 1598 m->m_len = 0; 1599 cp = mtod(m, char *); 1600 ep = mtod(m, char *) + M_TRAILINGSPACE(m); 1601 1602 /* if not certain about my name, return empty buffer */ 1603 if (namelen == 0) 1604 return m; 1605 1606 /* 1607 * guess if it looks like shortened hostname, or FQDN. 1608 * shortened hostname needs two trailing "\0". 1609 */ 1610 i = 0; 1611 for (p = name; p < name + namelen; p++) { 1612 if (*p && *p == '.') 1613 i++; 1614 } 1615 if (i < 2) 1616 nterm = 2; 1617 else 1618 nterm = 1; 1619 1620 p = name; 1621 while (cp < ep && p < name + namelen) { 1622 i = 0; 1623 for (q = p; q < name + namelen && *q && *q != '.'; q++) 1624 i++; 1625 /* result does not fit into mbuf */ 1626 if (cp + i + 1 >= ep) 1627 goto fail; 1628 /* 1629 * DNS label length restriction, RFC1035 page 8. 1630 * "i == 0" case is included here to avoid returning 1631 * 0-length label on "foo..bar". 1632 */ 1633 if (i <= 0 || i >= 64) 1634 goto fail; 1635 *cp++ = i; 1636 bcopy(p, cp, i); 1637 cp += i; 1638 p = q; 1639 if (p < name + namelen && *p == '.') 1640 p++; 1641 } 1642 /* termination */ 1643 if (cp + nterm >= ep) 1644 goto fail; 1645 while (nterm-- > 0) 1646 *cp++ = '\0'; 1647 m->m_len = cp - mtod(m, char *); 1648 return m; 1649 } 1650 1651 panic("should not reach here"); 1652 /* NOTREACHED */ 1653 1654 fail: 1655 if (m) 1656 m_freem(m); 1657 return NULL; 1658 } 1659 1660 /* 1661 * check if two DNS-encoded string matches. takes care of truncated 1662 * form (with \0\0 at the end). no compression support. 1663 * XXX upper/lowercase match (see RFC2065) 1664 */ 1665 static int 1666 ni6_dnsmatch(const char *a, int alen, const char *b, int blen) 1667 { 1668 const char *a0, *b0; 1669 int l; 1670 1671 /* simplest case - need validation? */ 1672 if (alen == blen && bcmp(a, b, alen) == 0) 1673 return 1; 1674 1675 a0 = a; 1676 b0 = b; 1677 1678 /* termination is mandatory */ 1679 if (alen < 2 || blen < 2) 1680 return 0; 1681 if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0') 1682 return 0; 1683 alen--; 1684 blen--; 1685 1686 while (a - a0 < alen && b - b0 < blen) { 1687 if (a - a0 + 1 > alen || b - b0 + 1 > blen) 1688 return 0; 1689 1690 if ((signed char)a[0] < 0 || (signed char)b[0] < 0) 1691 return 0; 1692 /* we don't support compression yet */ 1693 if (a[0] >= 64 || b[0] >= 64) 1694 return 0; 1695 1696 /* truncated case */ 1697 if (a[0] == 0 && a - a0 == alen - 1) 1698 return 1; 1699 if (b[0] == 0 && b - b0 == blen - 1) 1700 return 1; 1701 if (a[0] == 0 || b[0] == 0) 1702 return 0; 1703 1704 if (a[0] != b[0]) 1705 return 0; 1706 l = a[0]; 1707 if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen) 1708 return 0; 1709 if (bcmp(a + 1, b + 1, l) != 0) 1710 return 0; 1711 1712 a += 1 + l; 1713 b += 1 + l; 1714 } 1715 1716 if (a - a0 == alen && b - b0 == blen) 1717 return 1; 1718 else 1719 return 0; 1720 } 1721 1722 /* 1723 * calculate the number of addresses to be returned in the node info reply. 1724 */ 1725 static int 1726 ni6_addrs(struct icmp6_nodeinfo *ni6, struct mbuf *m, struct ifnet **ifpp, 1727 struct in6_addr *subj) 1728 { 1729 struct ifnet *ifp; 1730 struct in6_ifaddr *ifa6; 1731 struct ifaddr *ifa; 1732 int addrs = 0, addrsofif, iffound = 0; 1733 int niflags = ni6->ni_flags; 1734 1735 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) { 1736 switch (ni6->ni_code) { 1737 case ICMP6_NI_SUBJ_IPV6: 1738 if (subj == NULL) /* must be impossible... */ 1739 return (0); 1740 break; 1741 default: 1742 /* 1743 * XXX: we only support IPv6 subject address for 1744 * this Qtype. 1745 */ 1746 return (0); 1747 } 1748 } 1749 1750 IFNET_RLOCK_NOSLEEP(); 1751 TAILQ_FOREACH(ifp, &V_ifnet, if_link) { 1752 addrsofif = 0; 1753 IF_ADDR_RLOCK(ifp); 1754 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 1755 if (ifa->ifa_addr->sa_family != AF_INET6) 1756 continue; 1757 ifa6 = (struct in6_ifaddr *)ifa; 1758 1759 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 && 1760 IN6_ARE_ADDR_EQUAL(subj, &ifa6->ia_addr.sin6_addr)) 1761 iffound = 1; 1762 1763 /* 1764 * IPv4-mapped addresses can only be returned by a 1765 * Node Information proxy, since they represent 1766 * addresses of IPv4-only nodes, which perforce do 1767 * not implement this protocol. 1768 * [icmp-name-lookups-07, Section 5.4] 1769 * So we don't support NI_NODEADDR_FLAG_COMPAT in 1770 * this function at this moment. 1771 */ 1772 1773 /* What do we have to do about ::1? */ 1774 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { 1775 case IPV6_ADDR_SCOPE_LINKLOCAL: 1776 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) 1777 continue; 1778 break; 1779 case IPV6_ADDR_SCOPE_SITELOCAL: 1780 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) 1781 continue; 1782 break; 1783 case IPV6_ADDR_SCOPE_GLOBAL: 1784 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) 1785 continue; 1786 break; 1787 default: 1788 continue; 1789 } 1790 1791 /* 1792 * check if anycast is okay. 1793 * XXX: just experimental. not in the spec. 1794 */ 1795 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && 1796 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) 1797 continue; /* we need only unicast addresses */ 1798 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && 1799 (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) { 1800 continue; 1801 } 1802 addrsofif++; /* count the address */ 1803 } 1804 IF_ADDR_RUNLOCK(ifp); 1805 if (iffound) { 1806 *ifpp = ifp; 1807 IFNET_RUNLOCK_NOSLEEP(); 1808 return (addrsofif); 1809 } 1810 1811 addrs += addrsofif; 1812 } 1813 IFNET_RUNLOCK_NOSLEEP(); 1814 1815 return (addrs); 1816 } 1817 1818 static int 1819 ni6_store_addrs(struct icmp6_nodeinfo *ni6, struct icmp6_nodeinfo *nni6, 1820 struct ifnet *ifp0, int resid) 1821 { 1822 struct ifnet *ifp; 1823 struct in6_ifaddr *ifa6; 1824 struct ifaddr *ifa; 1825 struct ifnet *ifp_dep = NULL; 1826 int copied = 0, allow_deprecated = 0; 1827 u_char *cp = (u_char *)(nni6 + 1); 1828 int niflags = ni6->ni_flags; 1829 u_int32_t ltime; 1830 1831 if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL)) 1832 return (0); /* needless to copy */ 1833 1834 IFNET_RLOCK_NOSLEEP(); 1835 ifp = ifp0 ? ifp0 : TAILQ_FIRST(&V_ifnet); 1836 again: 1837 1838 for (; ifp; ifp = TAILQ_NEXT(ifp, if_link)) { 1839 IF_ADDR_RLOCK(ifp); 1840 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 1841 if (ifa->ifa_addr->sa_family != AF_INET6) 1842 continue; 1843 ifa6 = (struct in6_ifaddr *)ifa; 1844 1845 if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 && 1846 allow_deprecated == 0) { 1847 /* 1848 * prefererred address should be put before 1849 * deprecated addresses. 1850 */ 1851 1852 /* record the interface for later search */ 1853 if (ifp_dep == NULL) 1854 ifp_dep = ifp; 1855 1856 continue; 1857 } else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 && 1858 allow_deprecated != 0) 1859 continue; /* we now collect deprecated addrs */ 1860 1861 /* What do we have to do about ::1? */ 1862 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { 1863 case IPV6_ADDR_SCOPE_LINKLOCAL: 1864 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) 1865 continue; 1866 break; 1867 case IPV6_ADDR_SCOPE_SITELOCAL: 1868 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) 1869 continue; 1870 break; 1871 case IPV6_ADDR_SCOPE_GLOBAL: 1872 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) 1873 continue; 1874 break; 1875 default: 1876 continue; 1877 } 1878 1879 /* 1880 * check if anycast is okay. 1881 * XXX: just experimental. not in the spec. 1882 */ 1883 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && 1884 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) 1885 continue; 1886 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && 1887 (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) { 1888 continue; 1889 } 1890 1891 /* now we can copy the address */ 1892 if (resid < sizeof(struct in6_addr) + 1893 sizeof(u_int32_t)) { 1894 IF_ADDR_RUNLOCK(ifp); 1895 /* 1896 * We give up much more copy. 1897 * Set the truncate flag and return. 1898 */ 1899 nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE; 1900 IFNET_RUNLOCK_NOSLEEP(); 1901 return (copied); 1902 } 1903 1904 /* 1905 * Set the TTL of the address. 1906 * The TTL value should be one of the following 1907 * according to the specification: 1908 * 1909 * 1. The remaining lifetime of a DHCP lease on the 1910 * address, or 1911 * 2. The remaining Valid Lifetime of a prefix from 1912 * which the address was derived through Stateless 1913 * Autoconfiguration. 1914 * 1915 * Note that we currently do not support stateful 1916 * address configuration by DHCPv6, so the former 1917 * case can't happen. 1918 */ 1919 if (ifa6->ia6_lifetime.ia6t_expire == 0) 1920 ltime = ND6_INFINITE_LIFETIME; 1921 else { 1922 if (ifa6->ia6_lifetime.ia6t_expire > 1923 time_uptime) 1924 ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_uptime); 1925 else 1926 ltime = 0; 1927 } 1928 1929 bcopy(<ime, cp, sizeof(u_int32_t)); 1930 cp += sizeof(u_int32_t); 1931 1932 /* copy the address itself */ 1933 bcopy(&ifa6->ia_addr.sin6_addr, cp, 1934 sizeof(struct in6_addr)); 1935 in6_clearscope((struct in6_addr *)cp); /* XXX */ 1936 cp += sizeof(struct in6_addr); 1937 1938 resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t)); 1939 copied += (sizeof(struct in6_addr) + sizeof(u_int32_t)); 1940 } 1941 IF_ADDR_RUNLOCK(ifp); 1942 if (ifp0) /* we need search only on the specified IF */ 1943 break; 1944 } 1945 1946 if (allow_deprecated == 0 && ifp_dep != NULL) { 1947 ifp = ifp_dep; 1948 allow_deprecated = 1; 1949 1950 goto again; 1951 } 1952 1953 IFNET_RUNLOCK_NOSLEEP(); 1954 1955 return (copied); 1956 } 1957 1958 /* 1959 * XXX almost dup'ed code with rip6_input. 1960 */ 1961 static int 1962 icmp6_rip6_input(struct mbuf **mp, int off) 1963 { 1964 struct mbuf *m = *mp; 1965 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1966 struct inpcb *in6p; 1967 struct inpcb *last = NULL; 1968 struct sockaddr_in6 fromsa; 1969 struct icmp6_hdr *icmp6; 1970 struct mbuf *opts = NULL; 1971 1972 #ifndef PULLDOWN_TEST 1973 /* this is assumed to be safe. */ 1974 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off); 1975 #else 1976 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6)); 1977 if (icmp6 == NULL) { 1978 /* m is already reclaimed */ 1979 return (IPPROTO_DONE); 1980 } 1981 #endif 1982 1983 /* 1984 * XXX: the address may have embedded scope zone ID, which should be 1985 * hidden from applications. 1986 */ 1987 bzero(&fromsa, sizeof(fromsa)); 1988 fromsa.sin6_family = AF_INET6; 1989 fromsa.sin6_len = sizeof(struct sockaddr_in6); 1990 fromsa.sin6_addr = ip6->ip6_src; 1991 if (sa6_recoverscope(&fromsa)) { 1992 m_freem(m); 1993 return (IPPROTO_DONE); 1994 } 1995 1996 INP_INFO_RLOCK(&V_ripcbinfo); 1997 LIST_FOREACH(in6p, &V_ripcb, inp_list) { 1998 if ((in6p->inp_vflag & INP_IPV6) == 0) 1999 continue; 2000 if (in6p->inp_ip_p != IPPROTO_ICMPV6) 2001 continue; 2002 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) && 2003 !IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &ip6->ip6_dst)) 2004 continue; 2005 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr) && 2006 !IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src)) 2007 continue; 2008 INP_RLOCK(in6p); 2009 if (ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type, 2010 in6p->in6p_icmp6filt)) { 2011 INP_RUNLOCK(in6p); 2012 continue; 2013 } 2014 if (last != NULL) { 2015 struct mbuf *n = NULL; 2016 2017 /* 2018 * Recent network drivers tend to allocate a single 2019 * mbuf cluster, rather than to make a couple of 2020 * mbufs without clusters. Also, since the IPv6 code 2021 * path tries to avoid m_pullup(), it is highly 2022 * probable that we still have an mbuf cluster here 2023 * even though the necessary length can be stored in an 2024 * mbuf's internal buffer. 2025 * Meanwhile, the default size of the receive socket 2026 * buffer for raw sockets is not so large. This means 2027 * the possibility of packet loss is relatively higher 2028 * than before. To avoid this scenario, we copy the 2029 * received data to a separate mbuf that does not use 2030 * a cluster, if possible. 2031 * XXX: it is better to copy the data after stripping 2032 * intermediate headers. 2033 */ 2034 if ((m->m_flags & M_EXT) && m->m_next == NULL && 2035 m->m_len <= MHLEN) { 2036 n = m_get(M_NOWAIT, m->m_type); 2037 if (n != NULL) { 2038 if (m_dup_pkthdr(n, m, M_NOWAIT)) { 2039 bcopy(m->m_data, n->m_data, 2040 m->m_len); 2041 n->m_len = m->m_len; 2042 } else { 2043 m_free(n); 2044 n = NULL; 2045 } 2046 } 2047 } 2048 if (n != NULL || 2049 (n = m_copy(m, 0, (int)M_COPYALL)) != NULL) { 2050 if (last->inp_flags & INP_CONTROLOPTS) 2051 ip6_savecontrol(last, n, &opts); 2052 /* strip intermediate headers */ 2053 m_adj(n, off); 2054 SOCKBUF_LOCK(&last->inp_socket->so_rcv); 2055 if (sbappendaddr_locked( 2056 &last->inp_socket->so_rcv, 2057 (struct sockaddr *)&fromsa, n, opts) 2058 == 0) { 2059 /* should notify about lost packet */ 2060 m_freem(n); 2061 if (opts) { 2062 m_freem(opts); 2063 } 2064 SOCKBUF_UNLOCK( 2065 &last->inp_socket->so_rcv); 2066 } else 2067 sorwakeup_locked(last->inp_socket); 2068 opts = NULL; 2069 } 2070 INP_RUNLOCK(last); 2071 } 2072 last = in6p; 2073 } 2074 INP_INFO_RUNLOCK(&V_ripcbinfo); 2075 if (last != NULL) { 2076 if (last->inp_flags & INP_CONTROLOPTS) 2077 ip6_savecontrol(last, m, &opts); 2078 /* strip intermediate headers */ 2079 m_adj(m, off); 2080 2081 /* avoid using mbuf clusters if possible (see above) */ 2082 if ((m->m_flags & M_EXT) && m->m_next == NULL && 2083 m->m_len <= MHLEN) { 2084 struct mbuf *n; 2085 2086 n = m_get(M_NOWAIT, m->m_type); 2087 if (n != NULL) { 2088 if (m_dup_pkthdr(n, m, M_NOWAIT)) { 2089 bcopy(m->m_data, n->m_data, m->m_len); 2090 n->m_len = m->m_len; 2091 2092 m_freem(m); 2093 m = n; 2094 } else { 2095 m_freem(n); 2096 n = NULL; 2097 } 2098 } 2099 } 2100 SOCKBUF_LOCK(&last->inp_socket->so_rcv); 2101 if (sbappendaddr_locked(&last->inp_socket->so_rcv, 2102 (struct sockaddr *)&fromsa, m, opts) == 0) { 2103 m_freem(m); 2104 if (opts) 2105 m_freem(opts); 2106 SOCKBUF_UNLOCK(&last->inp_socket->so_rcv); 2107 } else 2108 sorwakeup_locked(last->inp_socket); 2109 INP_RUNLOCK(last); 2110 } else { 2111 m_freem(m); 2112 IP6STAT_DEC(ip6s_delivered); 2113 } 2114 return IPPROTO_DONE; 2115 } 2116 2117 /* 2118 * Reflect the ip6 packet back to the source. 2119 * OFF points to the icmp6 header, counted from the top of the mbuf. 2120 */ 2121 void 2122 icmp6_reflect(struct mbuf *m, size_t off) 2123 { 2124 struct in6_addr src, *srcp = NULL; 2125 struct ip6_hdr *ip6; 2126 struct icmp6_hdr *icmp6; 2127 struct in6_ifaddr *ia = NULL; 2128 struct ifnet *outif = NULL; 2129 int plen; 2130 int type, code; 2131 2132 /* too short to reflect */ 2133 if (off < sizeof(struct ip6_hdr)) { 2134 nd6log((LOG_DEBUG, 2135 "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n", 2136 (u_long)off, (u_long)sizeof(struct ip6_hdr), 2137 __FILE__, __LINE__)); 2138 goto bad; 2139 } 2140 2141 /* 2142 * If there are extra headers between IPv6 and ICMPv6, strip 2143 * off that header first. 2144 */ 2145 #ifdef DIAGNOSTIC 2146 if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN) 2147 panic("assumption failed in icmp6_reflect"); 2148 #endif 2149 if (off > sizeof(struct ip6_hdr)) { 2150 size_t l; 2151 struct ip6_hdr nip6; 2152 2153 l = off - sizeof(struct ip6_hdr); 2154 m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6); 2155 m_adj(m, 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 bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6)); 2162 } else /* off == sizeof(struct ip6_hdr) */ { 2163 size_t l; 2164 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 2165 if (m->m_len < l) { 2166 if ((m = m_pullup(m, l)) == NULL) 2167 return; 2168 } 2169 } 2170 plen = m->m_pkthdr.len - sizeof(struct ip6_hdr); 2171 ip6 = mtod(m, struct ip6_hdr *); 2172 ip6->ip6_nxt = IPPROTO_ICMPV6; 2173 icmp6 = (struct icmp6_hdr *)(ip6 + 1); 2174 type = icmp6->icmp6_type; /* keep type for statistics */ 2175 code = icmp6->icmp6_code; /* ditto. */ 2176 2177 /* 2178 * If the incoming packet was addressed directly to us (i.e. unicast), 2179 * use dst as the src for the reply. 2180 * The IN6_IFF_NOTREADY case should be VERY rare, but is possible 2181 * (for example) when we encounter an error while forwarding procedure 2182 * destined to a duplicated address of ours. 2183 */ 2184 if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 2185 ia = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */); 2186 if (ia != NULL && !(ia->ia6_flags & 2187 (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) 2188 srcp = &ia->ia_addr.sin6_addr; 2189 } 2190 2191 if (srcp == NULL) { 2192 int e; 2193 struct sockaddr_in6 sin6; 2194 struct route_in6 ro; 2195 2196 /* 2197 * This case matches to multicasts, our anycast, or unicasts 2198 * that we do not own. Select a source address based on the 2199 * source address of the erroneous packet. 2200 */ 2201 bzero(&sin6, sizeof(sin6)); 2202 sin6.sin6_family = AF_INET6; 2203 sin6.sin6_len = sizeof(sin6); 2204 sin6.sin6_addr = ip6->ip6_dst; /* zone ID should be embedded */ 2205 2206 bzero(&ro, sizeof(ro)); 2207 e = in6_selectsrc(&sin6, NULL, NULL, &ro, NULL, &outif, &src); 2208 if (ro.ro_rt) 2209 RTFREE(ro.ro_rt); /* XXX: we could use this */ 2210 if (e) { 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, &sin6.sin6_addr), e)); 2216 goto bad; 2217 } 2218 srcp = &src; 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 if (outif) 2231 ip6->ip6_hlim = ND_IFINFO(outif)->chlim; 2232 else if (m->m_pkthdr.rcvif) { 2233 /* XXX: This may not be the outgoing interface */ 2234 ip6->ip6_hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim; 2235 } else 2236 ip6->ip6_hlim = V_ip6_defhlim; 2237 2238 icmp6->icmp6_cksum = 0; 2239 icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2240 sizeof(struct ip6_hdr), plen); 2241 2242 /* 2243 * XXX option handling 2244 */ 2245 2246 m->m_flags &= ~(M_BCAST|M_MCAST); 2247 2248 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2249 if (outif) 2250 icmp6_ifoutstat_inc(outif, type, code); 2251 2252 if (ia != NULL) 2253 ifa_free(&ia->ia_ifa); 2254 return; 2255 2256 bad: 2257 if (ia != NULL) 2258 ifa_free(&ia->ia_ifa); 2259 m_freem(m); 2260 return; 2261 } 2262 2263 void 2264 icmp6_fasttimo(void) 2265 { 2266 2267 mld_fasttimo(); 2268 } 2269 2270 void 2271 icmp6_slowtimo(void) 2272 { 2273 2274 mld_slowtimo(); 2275 } 2276 2277 static const char * 2278 icmp6_redirect_diag(struct in6_addr *src6, struct in6_addr *dst6, 2279 struct in6_addr *tgt6) 2280 { 2281 static char buf[1024]; 2282 char ip6bufs[INET6_ADDRSTRLEN]; 2283 char ip6bufd[INET6_ADDRSTRLEN]; 2284 char ip6buft[INET6_ADDRSTRLEN]; 2285 snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)", 2286 ip6_sprintf(ip6bufs, src6), ip6_sprintf(ip6bufd, dst6), 2287 ip6_sprintf(ip6buft, tgt6)); 2288 return buf; 2289 } 2290 2291 void 2292 icmp6_redirect_input(struct mbuf *m, int off) 2293 { 2294 struct ifnet *ifp; 2295 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 2296 struct nd_redirect *nd_rd; 2297 int icmp6len = ntohs(ip6->ip6_plen); 2298 char *lladdr = NULL; 2299 int lladdrlen = 0; 2300 struct rtentry *rt = NULL; 2301 int is_router; 2302 int is_onlink; 2303 struct in6_addr src6 = ip6->ip6_src; 2304 struct in6_addr redtgt6; 2305 struct in6_addr reddst6; 2306 union nd_opts ndopts; 2307 char ip6buf[INET6_ADDRSTRLEN]; 2308 2309 M_ASSERTPKTHDR(m); 2310 KASSERT(m->m_pkthdr.rcvif != NULL, ("%s: no rcvif", __func__)); 2311 2312 ifp = m->m_pkthdr.rcvif; 2313 2314 /* XXX if we are router, we don't update route by icmp6 redirect */ 2315 if (V_ip6_forwarding) 2316 goto freeit; 2317 if (!V_icmp6_rediraccept) 2318 goto freeit; 2319 2320 #ifndef PULLDOWN_TEST 2321 IP6_EXTHDR_CHECK(m, off, icmp6len,); 2322 nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off); 2323 #else 2324 IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len); 2325 if (nd_rd == NULL) { 2326 ICMP6STAT_INC(icp6s_tooshort); 2327 return; 2328 } 2329 #endif 2330 redtgt6 = nd_rd->nd_rd_target; 2331 reddst6 = nd_rd->nd_rd_dst; 2332 2333 if (in6_setscope(&redtgt6, m->m_pkthdr.rcvif, NULL) || 2334 in6_setscope(&reddst6, m->m_pkthdr.rcvif, NULL)) { 2335 goto freeit; 2336 } 2337 2338 /* validation */ 2339 if (!IN6_IS_ADDR_LINKLOCAL(&src6)) { 2340 nd6log((LOG_ERR, 2341 "ICMP6 redirect sent from %s rejected; " 2342 "must be from linklocal\n", 2343 ip6_sprintf(ip6buf, &src6))); 2344 goto bad; 2345 } 2346 if (ip6->ip6_hlim != 255) { 2347 nd6log((LOG_ERR, 2348 "ICMP6 redirect sent from %s rejected; " 2349 "hlim=%d (must be 255)\n", 2350 ip6_sprintf(ip6buf, &src6), ip6->ip6_hlim)); 2351 goto bad; 2352 } 2353 { 2354 /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */ 2355 struct sockaddr_in6 sin6; 2356 struct in6_addr *gw6; 2357 2358 bzero(&sin6, sizeof(sin6)); 2359 sin6.sin6_family = AF_INET6; 2360 sin6.sin6_len = sizeof(struct sockaddr_in6); 2361 bcopy(&reddst6, &sin6.sin6_addr, sizeof(reddst6)); 2362 rt = in6_rtalloc1((struct sockaddr *)&sin6, 0, 0UL, RT_DEFAULT_FIB); 2363 if (rt) { 2364 if (rt->rt_gateway == NULL || 2365 rt->rt_gateway->sa_family != AF_INET6) { 2366 RTFREE_LOCKED(rt); 2367 nd6log((LOG_ERR, 2368 "ICMP6 redirect rejected; no route " 2369 "with inet6 gateway found for redirect dst: %s\n", 2370 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2371 goto bad; 2372 } 2373 2374 gw6 = &(((struct sockaddr_in6 *)rt->rt_gateway)->sin6_addr); 2375 if (bcmp(&src6, gw6, sizeof(struct in6_addr)) != 0) { 2376 RTFREE_LOCKED(rt); 2377 nd6log((LOG_ERR, 2378 "ICMP6 redirect rejected; " 2379 "not equal to gw-for-src=%s (must be same): " 2380 "%s\n", 2381 ip6_sprintf(ip6buf, gw6), 2382 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2383 goto bad; 2384 } 2385 } else { 2386 nd6log((LOG_ERR, 2387 "ICMP6 redirect rejected; " 2388 "no route found for redirect dst: %s\n", 2389 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2390 goto bad; 2391 } 2392 RTFREE_LOCKED(rt); 2393 rt = NULL; 2394 } 2395 if (IN6_IS_ADDR_MULTICAST(&reddst6)) { 2396 nd6log((LOG_ERR, 2397 "ICMP6 redirect rejected; " 2398 "redirect dst must be unicast: %s\n", 2399 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2400 goto bad; 2401 } 2402 2403 is_router = is_onlink = 0; 2404 if (IN6_IS_ADDR_LINKLOCAL(&redtgt6)) 2405 is_router = 1; /* router case */ 2406 if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0) 2407 is_onlink = 1; /* on-link destination case */ 2408 if (!is_router && !is_onlink) { 2409 nd6log((LOG_ERR, 2410 "ICMP6 redirect rejected; " 2411 "neither router case nor onlink case: %s\n", 2412 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2413 goto bad; 2414 } 2415 /* validation passed */ 2416 2417 icmp6len -= sizeof(*nd_rd); 2418 nd6_option_init(nd_rd + 1, icmp6len, &ndopts); 2419 if (nd6_options(&ndopts) < 0) { 2420 nd6log((LOG_INFO, "%s: invalid ND option, rejected: %s\n", 2421 __func__, icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2422 /* nd6_options have incremented stats */ 2423 goto freeit; 2424 } 2425 2426 if (ndopts.nd_opts_tgt_lladdr) { 2427 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 2428 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 2429 } 2430 2431 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 2432 nd6log((LOG_INFO, "%s: lladdrlen mismatch for %s " 2433 "(if %d, icmp6 packet %d): %s\n", 2434 __func__, ip6_sprintf(ip6buf, &redtgt6), 2435 ifp->if_addrlen, lladdrlen - 2, 2436 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2437 goto bad; 2438 } 2439 2440 /* RFC 2461 8.3 */ 2441 nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT, 2442 is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER); 2443 2444 if (!is_onlink) { /* better router case. perform rtredirect. */ 2445 /* perform rtredirect */ 2446 struct sockaddr_in6 sdst; 2447 struct sockaddr_in6 sgw; 2448 struct sockaddr_in6 ssrc; 2449 u_int fibnum; 2450 2451 bzero(&sdst, sizeof(sdst)); 2452 bzero(&sgw, sizeof(sgw)); 2453 bzero(&ssrc, sizeof(ssrc)); 2454 sdst.sin6_family = sgw.sin6_family = ssrc.sin6_family = AF_INET6; 2455 sdst.sin6_len = sgw.sin6_len = ssrc.sin6_len = 2456 sizeof(struct sockaddr_in6); 2457 bcopy(&redtgt6, &sgw.sin6_addr, sizeof(struct in6_addr)); 2458 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr)); 2459 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr)); 2460 for (fibnum = 0; fibnum < rt_numfibs; fibnum++) 2461 in6_rtredirect((struct sockaddr *)&sdst, 2462 (struct sockaddr *)&sgw, (struct sockaddr *)NULL, 2463 RTF_GATEWAY | RTF_HOST, (struct sockaddr *)&ssrc, 2464 fibnum); 2465 } 2466 /* finally update cached route in each socket via pfctlinput */ 2467 { 2468 struct sockaddr_in6 sdst; 2469 2470 bzero(&sdst, sizeof(sdst)); 2471 sdst.sin6_family = AF_INET6; 2472 sdst.sin6_len = sizeof(struct sockaddr_in6); 2473 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr)); 2474 pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst); 2475 #ifdef IPSEC 2476 key_sa_routechange((struct sockaddr *)&sdst); 2477 #endif /* IPSEC */ 2478 } 2479 2480 freeit: 2481 m_freem(m); 2482 return; 2483 2484 bad: 2485 ICMP6STAT_INC(icp6s_badredirect); 2486 m_freem(m); 2487 } 2488 2489 void 2490 icmp6_redirect_output(struct mbuf *m0, struct rtentry *rt) 2491 { 2492 struct ifnet *ifp; /* my outgoing interface */ 2493 struct in6_addr *ifp_ll6; 2494 struct in6_addr *router_ll6; 2495 struct ip6_hdr *sip6; /* m0 as struct ip6_hdr */ 2496 struct mbuf *m = NULL; /* newly allocated one */ 2497 struct m_tag *mtag; 2498 struct ip6_hdr *ip6; /* m as struct ip6_hdr */ 2499 struct nd_redirect *nd_rd; 2500 struct llentry *ln = NULL; 2501 size_t maxlen; 2502 u_char *p; 2503 struct ifnet *outif = NULL; 2504 struct sockaddr_in6 src_sa; 2505 2506 icmp6_errcount(ND_REDIRECT, 0); 2507 2508 /* if we are not router, we don't send icmp6 redirect */ 2509 if (!V_ip6_forwarding) 2510 goto fail; 2511 2512 /* sanity check */ 2513 if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp)) 2514 goto fail; 2515 2516 /* 2517 * Address check: 2518 * the source address must identify a neighbor, and 2519 * the destination address must not be a multicast address 2520 * [RFC 2461, sec 8.2] 2521 */ 2522 sip6 = mtod(m0, struct ip6_hdr *); 2523 bzero(&src_sa, sizeof(src_sa)); 2524 src_sa.sin6_family = AF_INET6; 2525 src_sa.sin6_len = sizeof(src_sa); 2526 src_sa.sin6_addr = sip6->ip6_src; 2527 if (nd6_is_addr_neighbor(&src_sa, ifp) == 0) 2528 goto fail; 2529 if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst)) 2530 goto fail; /* what should we do here? */ 2531 2532 /* rate limit */ 2533 if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0)) 2534 goto fail; 2535 2536 /* 2537 * Since we are going to append up to 1280 bytes (= IPV6_MMTU), 2538 * we almost always ask for an mbuf cluster for simplicity. 2539 * (MHLEN < IPV6_MMTU is almost always true) 2540 */ 2541 #if IPV6_MMTU >= MCLBYTES 2542 # error assumption failed about IPV6_MMTU and MCLBYTES 2543 #endif 2544 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 2545 if (m == NULL) 2546 goto fail; 2547 M_SETFIB(m, rt->rt_fibnum); 2548 maxlen = M_TRAILINGSPACE(m); 2549 maxlen = min(IPV6_MMTU, maxlen); 2550 /* just for safety */ 2551 if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) + 2552 ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) { 2553 goto fail; 2554 } 2555 2556 { 2557 /* get ip6 linklocal address for ifp(my outgoing interface). */ 2558 struct in6_ifaddr *ia; 2559 if ((ia = in6ifa_ifpforlinklocal(ifp, 2560 IN6_IFF_NOTREADY| 2561 IN6_IFF_ANYCAST)) == NULL) 2562 goto fail; 2563 ifp_ll6 = &ia->ia_addr.sin6_addr; 2564 /* XXXRW: reference released prematurely. */ 2565 ifa_free(&ia->ia_ifa); 2566 } 2567 2568 /* get ip6 linklocal address for the router. */ 2569 if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) { 2570 struct sockaddr_in6 *sin6; 2571 sin6 = (struct sockaddr_in6 *)rt->rt_gateway; 2572 router_ll6 = &sin6->sin6_addr; 2573 if (!IN6_IS_ADDR_LINKLOCAL(router_ll6)) 2574 router_ll6 = (struct in6_addr *)NULL; 2575 } else 2576 router_ll6 = (struct in6_addr *)NULL; 2577 2578 /* ip6 */ 2579 ip6 = mtod(m, struct ip6_hdr *); 2580 ip6->ip6_flow = 0; 2581 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2582 ip6->ip6_vfc |= IPV6_VERSION; 2583 /* ip6->ip6_plen will be set later */ 2584 ip6->ip6_nxt = IPPROTO_ICMPV6; 2585 ip6->ip6_hlim = 255; 2586 /* ip6->ip6_src must be linklocal addr for my outgoing if. */ 2587 bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr)); 2588 bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr)); 2589 2590 /* ND Redirect */ 2591 nd_rd = (struct nd_redirect *)(ip6 + 1); 2592 nd_rd->nd_rd_type = ND_REDIRECT; 2593 nd_rd->nd_rd_code = 0; 2594 nd_rd->nd_rd_reserved = 0; 2595 if (rt->rt_flags & RTF_GATEWAY) { 2596 /* 2597 * nd_rd->nd_rd_target must be a link-local address in 2598 * better router cases. 2599 */ 2600 if (!router_ll6) 2601 goto fail; 2602 bcopy(router_ll6, &nd_rd->nd_rd_target, 2603 sizeof(nd_rd->nd_rd_target)); 2604 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2605 sizeof(nd_rd->nd_rd_dst)); 2606 } else { 2607 /* make sure redtgt == reddst */ 2608 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target, 2609 sizeof(nd_rd->nd_rd_target)); 2610 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2611 sizeof(nd_rd->nd_rd_dst)); 2612 } 2613 2614 p = (u_char *)(nd_rd + 1); 2615 2616 if (!router_ll6) 2617 goto nolladdropt; 2618 2619 { 2620 /* target lladdr option */ 2621 int len; 2622 struct nd_opt_hdr *nd_opt; 2623 char *lladdr; 2624 2625 IF_AFDATA_RLOCK(ifp); 2626 ln = nd6_lookup(router_ll6, 0, ifp); 2627 IF_AFDATA_RUNLOCK(ifp); 2628 if (ln == NULL) 2629 goto nolladdropt; 2630 2631 len = sizeof(*nd_opt) + ifp->if_addrlen; 2632 len = (len + 7) & ~7; /* round by 8 */ 2633 /* safety check */ 2634 if (len + (p - (u_char *)ip6) > maxlen) 2635 goto nolladdropt; 2636 2637 if (ln->la_flags & LLE_VALID) { 2638 nd_opt = (struct nd_opt_hdr *)p; 2639 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 2640 nd_opt->nd_opt_len = len >> 3; 2641 lladdr = (char *)(nd_opt + 1); 2642 bcopy(&ln->ll_addr, lladdr, ifp->if_addrlen); 2643 p += len; 2644 } 2645 } 2646 nolladdropt: 2647 if (ln != NULL) 2648 LLE_RUNLOCK(ln); 2649 2650 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2651 2652 /* just to be safe */ 2653 #ifdef M_DECRYPTED /*not openbsd*/ 2654 if (m0->m_flags & M_DECRYPTED) 2655 goto noredhdropt; 2656 #endif 2657 if (p - (u_char *)ip6 > maxlen) 2658 goto noredhdropt; 2659 2660 { 2661 /* redirected header option */ 2662 int len; 2663 struct nd_opt_rd_hdr *nd_opt_rh; 2664 2665 /* 2666 * compute the maximum size for icmp6 redirect header option. 2667 * XXX room for auth header? 2668 */ 2669 len = maxlen - (p - (u_char *)ip6); 2670 len &= ~7; 2671 2672 /* This is just for simplicity. */ 2673 if (m0->m_pkthdr.len != m0->m_len) { 2674 if (m0->m_next) { 2675 m_freem(m0->m_next); 2676 m0->m_next = NULL; 2677 } 2678 m0->m_pkthdr.len = m0->m_len; 2679 } 2680 2681 /* 2682 * Redirected header option spec (RFC2461 4.6.3) talks nothing 2683 * about padding/truncate rule for the original IP packet. 2684 * From the discussion on IPv6imp in Feb 1999, 2685 * the consensus was: 2686 * - "attach as much as possible" is the goal 2687 * - pad if not aligned (original size can be guessed by 2688 * original ip6 header) 2689 * Following code adds the padding if it is simple enough, 2690 * and truncates if not. 2691 */ 2692 if (m0->m_next || m0->m_pkthdr.len != m0->m_len) 2693 panic("assumption failed in %s:%d", __FILE__, 2694 __LINE__); 2695 2696 if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) { 2697 /* not enough room, truncate */ 2698 m0->m_pkthdr.len = m0->m_len = len - 2699 sizeof(*nd_opt_rh); 2700 } else { 2701 /* enough room, pad or truncate */ 2702 size_t extra; 2703 2704 extra = m0->m_pkthdr.len % 8; 2705 if (extra) { 2706 /* pad if easy enough, truncate if not */ 2707 if (8 - extra <= M_TRAILINGSPACE(m0)) { 2708 /* pad */ 2709 m0->m_len += (8 - extra); 2710 m0->m_pkthdr.len += (8 - extra); 2711 } else { 2712 /* truncate */ 2713 m0->m_pkthdr.len -= extra; 2714 m0->m_len -= extra; 2715 } 2716 } 2717 len = m0->m_pkthdr.len + sizeof(*nd_opt_rh); 2718 m0->m_pkthdr.len = m0->m_len = len - 2719 sizeof(*nd_opt_rh); 2720 } 2721 2722 nd_opt_rh = (struct nd_opt_rd_hdr *)p; 2723 bzero(nd_opt_rh, sizeof(*nd_opt_rh)); 2724 nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER; 2725 nd_opt_rh->nd_opt_rh_len = len >> 3; 2726 p += sizeof(*nd_opt_rh); 2727 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2728 2729 /* connect m0 to m */ 2730 m_tag_delete_chain(m0, NULL); 2731 m0->m_flags &= ~M_PKTHDR; 2732 m->m_next = m0; 2733 m->m_pkthdr.len = m->m_len + m0->m_len; 2734 m0 = NULL; 2735 } 2736 noredhdropt:; 2737 if (m0) { 2738 m_freem(m0); 2739 m0 = NULL; 2740 } 2741 2742 /* XXX: clear embedded link IDs in the inner header */ 2743 in6_clearscope(&sip6->ip6_src); 2744 in6_clearscope(&sip6->ip6_dst); 2745 in6_clearscope(&nd_rd->nd_rd_target); 2746 in6_clearscope(&nd_rd->nd_rd_dst); 2747 2748 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr)); 2749 2750 nd_rd->nd_rd_cksum = 0; 2751 nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2752 sizeof(*ip6), ntohs(ip6->ip6_plen)); 2753 2754 if (send_sendso_input_hook != NULL) { 2755 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, sizeof(unsigned short), 2756 M_NOWAIT); 2757 if (mtag == NULL) 2758 goto fail; 2759 *(unsigned short *)(mtag + 1) = nd_rd->nd_rd_type; 2760 m_tag_prepend(m, mtag); 2761 } 2762 2763 /* send the packet to outside... */ 2764 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2765 if (outif) { 2766 icmp6_ifstat_inc(outif, ifs6_out_msg); 2767 icmp6_ifstat_inc(outif, ifs6_out_redirect); 2768 } 2769 ICMP6STAT_INC(icp6s_outhist[ND_REDIRECT]); 2770 2771 return; 2772 2773 fail: 2774 if (m) 2775 m_freem(m); 2776 if (m0) 2777 m_freem(m0); 2778 } 2779 2780 /* 2781 * ICMPv6 socket option processing. 2782 */ 2783 int 2784 icmp6_ctloutput(struct socket *so, struct sockopt *sopt) 2785 { 2786 int error = 0; 2787 int optlen; 2788 struct inpcb *inp = sotoinpcb(so); 2789 int level, op, optname; 2790 2791 if (sopt) { 2792 level = sopt->sopt_level; 2793 op = sopt->sopt_dir; 2794 optname = sopt->sopt_name; 2795 optlen = sopt->sopt_valsize; 2796 } else 2797 level = op = optname = optlen = 0; 2798 2799 if (level != IPPROTO_ICMPV6) { 2800 return EINVAL; 2801 } 2802 2803 switch (op) { 2804 case PRCO_SETOPT: 2805 switch (optname) { 2806 case ICMP6_FILTER: 2807 { 2808 struct icmp6_filter ic6f; 2809 2810 if (optlen != sizeof(ic6f)) { 2811 error = EMSGSIZE; 2812 break; 2813 } 2814 error = sooptcopyin(sopt, &ic6f, optlen, optlen); 2815 if (error == 0) { 2816 INP_WLOCK(inp); 2817 *inp->in6p_icmp6filt = ic6f; 2818 INP_WUNLOCK(inp); 2819 } 2820 break; 2821 } 2822 2823 default: 2824 error = ENOPROTOOPT; 2825 break; 2826 } 2827 break; 2828 2829 case PRCO_GETOPT: 2830 switch (optname) { 2831 case ICMP6_FILTER: 2832 { 2833 struct icmp6_filter ic6f; 2834 2835 INP_RLOCK(inp); 2836 ic6f = *inp->in6p_icmp6filt; 2837 INP_RUNLOCK(inp); 2838 error = sooptcopyout(sopt, &ic6f, sizeof(ic6f)); 2839 break; 2840 } 2841 2842 default: 2843 error = ENOPROTOOPT; 2844 break; 2845 } 2846 break; 2847 } 2848 2849 return (error); 2850 } 2851 2852 /* 2853 * Perform rate limit check. 2854 * Returns 0 if it is okay to send the icmp6 packet. 2855 * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate 2856 * limitation. 2857 * 2858 * XXX per-destination/type check necessary? 2859 * 2860 * dst - not used at this moment 2861 * type - not used at this moment 2862 * code - not used at this moment 2863 */ 2864 static int 2865 icmp6_ratelimit(const struct in6_addr *dst, const int type, 2866 const int code) 2867 { 2868 int ret; 2869 2870 ret = 0; /* okay to send */ 2871 2872 /* PPS limit */ 2873 if (!ppsratecheck(&V_icmp6errppslim_last, &V_icmp6errpps_count, 2874 V_icmp6errppslim)) { 2875 /* The packet is subject to rate limit */ 2876 ret++; 2877 } 2878 2879 return ret; 2880 } 2881