1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the project nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * $KAME: icmp6.c,v 1.211 2001/04/04 05:56:20 itojun Exp $ 32 */ 33 34 /*- 35 * Copyright (c) 1982, 1986, 1988, 1993 36 * The Regents of the University of California. All rights reserved. 37 * 38 * Redistribution and use in source and binary forms, with or without 39 * modification, are permitted provided that the following conditions 40 * are met: 41 * 1. Redistributions of source code must retain the above copyright 42 * notice, this list of conditions and the following disclaimer. 43 * 2. Redistributions in binary form must reproduce the above copyright 44 * notice, this list of conditions and the following disclaimer in the 45 * documentation and/or other materials provided with the distribution. 46 * 3. Neither the name of the University nor the names of its contributors 47 * may be used to endorse or promote products derived from this software 48 * without specific prior written permission. 49 * 50 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 51 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 52 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 53 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 54 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 55 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 56 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 57 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 58 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 59 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 60 * SUCH DAMAGE. 61 */ 62 63 #define MBUF_PRIVATE /* XXXRW: Optimisation tries to avoid M_EXT mbufs */ 64 65 #include "opt_inet.h" 66 #include "opt_inet6.h" 67 68 #include <sys/param.h> 69 #include <sys/domain.h> 70 #include <sys/jail.h> 71 #include <sys/kernel.h> 72 #include <sys/lock.h> 73 #include <sys/malloc.h> 74 #include <sys/mbuf.h> 75 #include <sys/proc.h> 76 #include <sys/protosw.h> 77 #include <sys/signalvar.h> 78 #include <sys/socket.h> 79 #include <sys/socketvar.h> 80 #include <sys/sx.h> 81 #include <sys/syslog.h> 82 #include <sys/systm.h> 83 #include <sys/time.h> 84 85 #include <net/if.h> 86 #include <net/if_var.h> 87 #include <net/if_dl.h> 88 #include <net/if_llatbl.h> 89 #include <net/if_private.h> 90 #include <net/if_types.h> 91 #include <net/route.h> 92 #include <net/route/route_ctl.h> 93 #include <net/route/nhop.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/ip6_var.h> 107 #include <netinet6/scope6_var.h> 108 #include <netinet6/mld6_var.h> 109 #include <netinet6/nd6.h> 110 #include <netinet6/send.h> 111 112 extern ip6proto_ctlinput_t *ip6_ctlprotox[]; 113 114 VNET_PCPUSTAT_DEFINE(struct icmp6stat, icmp6stat); 115 VNET_PCPUSTAT_SYSINIT(icmp6stat); 116 SYSCTL_VNET_PCPUSTAT(_net_inet6_icmp6, ICMPV6CTL_STATS, stats, 117 struct icmp6stat, icmp6stat, 118 "ICMPv6 statistics (struct icmp6stat, netinet/icmp6.h)"); 119 120 #ifdef VIMAGE 121 VNET_PCPUSTAT_SYSUNINIT(icmp6stat); 122 #endif /* VIMAGE */ 123 124 VNET_DEFINE_STATIC(int, icmp6_rediraccept) = 1; 125 #define V_icmp6_rediraccept VNET(icmp6_rediraccept) 126 SYSCTL_INT(_net_inet6_icmp6, ICMPV6CTL_REDIRACCEPT, rediraccept, 127 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(icmp6_rediraccept), 0, 128 "Accept ICMPv6 redirect messages"); 129 130 VNET_DEFINE_STATIC(int, icmp6_redirtimeout) = 10 * 60; /* 10 minutes */ 131 #define V_icmp6_redirtimeout VNET(icmp6_redirtimeout) 132 SYSCTL_INT(_net_inet6_icmp6, ICMPV6CTL_REDIRTIMEOUT, redirtimeout, 133 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(icmp6_redirtimeout), 0, 134 "Delay in seconds before expiring redirect route"); 135 136 VNET_DEFINE_STATIC(int, icmp6_nodeinfo) = 0; 137 #define V_icmp6_nodeinfo VNET(icmp6_nodeinfo) 138 SYSCTL_INT(_net_inet6_icmp6, ICMPV6CTL_NODEINFO, nodeinfo, 139 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(icmp6_nodeinfo), 0, 140 "Mask of enabled RFC4620 node information query types"); 141 142 VNET_DECLARE(struct inpcbinfo, ripcbinfo); 143 #define V_ripcbinfo VNET(ripcbinfo) 144 145 VNET_DECLARE(int, rip_bind_all_fibs); 146 #define V_rip_bind_all_fibs VNET(rip_bind_all_fibs) 147 148 static void icmp6_errcount(int, int); 149 static int icmp6_rip6_input(struct mbuf **, int); 150 static void icmp6_reflect(struct mbuf *, size_t); 151 static const char *icmp6_redirect_diag(struct in6_addr *, 152 struct in6_addr *, struct in6_addr *); 153 static struct mbuf *ni6_input(struct mbuf *, int, struct prison *); 154 static struct mbuf *ni6_nametodns(const char *, int, int); 155 static int ni6_dnsmatch(const char *, int, const char *, int); 156 static int ni6_addrs(struct icmp6_nodeinfo *, struct mbuf *, 157 struct ifnet **, struct in6_addr *); 158 static int ni6_store_addrs(struct icmp6_nodeinfo *, struct icmp6_nodeinfo *, 159 struct ifnet *, int); 160 static int icmp6_notify_error(struct mbuf **, int, int); 161 static void icmp6_mtudisc_update(struct ip6ctlparam *ip6cp); 162 163 /* 164 * Kernel module interface for updating icmp6stat. The argument is an index 165 * into icmp6stat treated as an array of u_quad_t. While this encodes the 166 * general layout of icmp6stat into the caller, it doesn't encode its 167 * location, so that future changes to add, for example, per-CPU stats 168 * support won't cause binary compatibility problems for kernel modules. 169 */ 170 void 171 kmod_icmp6stat_inc(int statnum) 172 { 173 174 counter_u64_add(VNET(icmp6stat)[statnum], 1); 175 } 176 177 static void 178 icmp6_errcount(int type, int code) 179 { 180 switch (type) { 181 case ICMP6_DST_UNREACH: 182 switch (code) { 183 case ICMP6_DST_UNREACH_NOROUTE: 184 ICMP6STAT_INC(icp6s_odst_unreach_noroute); 185 return; 186 case ICMP6_DST_UNREACH_ADMIN: 187 ICMP6STAT_INC(icp6s_odst_unreach_admin); 188 return; 189 case ICMP6_DST_UNREACH_BEYONDSCOPE: 190 ICMP6STAT_INC(icp6s_odst_unreach_beyondscope); 191 return; 192 case ICMP6_DST_UNREACH_ADDR: 193 ICMP6STAT_INC(icp6s_odst_unreach_addr); 194 return; 195 case ICMP6_DST_UNREACH_NOPORT: 196 ICMP6STAT_INC(icp6s_odst_unreach_noport); 197 return; 198 } 199 break; 200 case ICMP6_PACKET_TOO_BIG: 201 ICMP6STAT_INC(icp6s_opacket_too_big); 202 return; 203 case ICMP6_TIME_EXCEEDED: 204 switch (code) { 205 case ICMP6_TIME_EXCEED_TRANSIT: 206 ICMP6STAT_INC(icp6s_otime_exceed_transit); 207 return; 208 case ICMP6_TIME_EXCEED_REASSEMBLY: 209 ICMP6STAT_INC(icp6s_otime_exceed_reassembly); 210 return; 211 } 212 break; 213 case ICMP6_PARAM_PROB: 214 switch (code) { 215 case ICMP6_PARAMPROB_HEADER: 216 ICMP6STAT_INC(icp6s_oparamprob_header); 217 return; 218 case ICMP6_PARAMPROB_NEXTHEADER: 219 ICMP6STAT_INC(icp6s_oparamprob_nextheader); 220 return; 221 case ICMP6_PARAMPROB_OPTION: 222 ICMP6STAT_INC(icp6s_oparamprob_option); 223 return; 224 } 225 break; 226 case ND_REDIRECT: 227 ICMP6STAT_INC(icp6s_oredirect); 228 return; 229 } 230 ICMP6STAT_INC(icp6s_ounknown); 231 } 232 233 /* 234 * A wrapper function for icmp6_error() necessary when the erroneous packet 235 * may not contain enough scope zone information. 236 */ 237 void 238 icmp6_error2(struct mbuf *m, int type, int code, int param, 239 struct ifnet *ifp) 240 { 241 struct ip6_hdr *ip6; 242 243 if (ifp == NULL) 244 return; 245 246 if (m->m_len < sizeof(struct ip6_hdr)) { 247 m = m_pullup(m, sizeof(struct ip6_hdr)); 248 if (m == NULL) { 249 IP6STAT_INC(ip6s_exthdrtoolong); 250 return; 251 } 252 } 253 ip6 = mtod(m, struct ip6_hdr *); 254 255 if (in6_setscope(&ip6->ip6_src, ifp, NULL) != 0) 256 return; 257 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0) 258 return; 259 260 icmp6_error(m, type, code, param); 261 } 262 263 /* 264 * Generate an error packet of type error in response to bad IP6 packet. 265 */ 266 void 267 icmp6_error(struct mbuf *m, int type, int code, int param) 268 { 269 struct ip6_hdr *oip6, *nip6; 270 struct icmp6_hdr *icmp6; 271 struct epoch_tracker et; 272 u_int preplen; 273 int off; 274 int nxt; 275 276 ICMP6STAT_INC(icp6s_error); 277 278 /* count per-type-code statistics */ 279 icmp6_errcount(type, code); 280 281 #ifdef M_DECRYPTED /*not openbsd*/ 282 if (m->m_flags & M_DECRYPTED) { 283 ICMP6STAT_INC(icp6s_canterror); 284 goto freeit; 285 } 286 #endif 287 288 if (m->m_len < sizeof(struct ip6_hdr)) { 289 m = m_pullup(m, sizeof(struct ip6_hdr)); 290 if (m == NULL) { 291 IP6STAT_INC(ip6s_exthdrtoolong); 292 return; 293 } 294 } 295 oip6 = mtod(m, struct ip6_hdr *); 296 297 /* 298 * If the destination address of the erroneous packet is a multicast 299 * address, or the packet was sent using link-layer multicast, 300 * we should basically suppress sending an error (RFC 2463, Section 301 * 2.4). 302 * We have two exceptions (the item e.2 in that section): 303 * - the Packet Too Big message can be sent for path MTU discovery. 304 * - the Parameter Problem Message that can be allowed an icmp6 error 305 * in the option type field. This check has been done in 306 * ip6_unknown_opt(), so we can just check the type and code. 307 */ 308 if ((m->m_flags & (M_BCAST|M_MCAST) || 309 IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) && 310 (type != ICMP6_PACKET_TOO_BIG && 311 (type != ICMP6_PARAM_PROB || 312 code != ICMP6_PARAMPROB_OPTION))) 313 goto freeit; 314 315 /* 316 * RFC 2463, 2.4 (e.5): source address check. 317 * XXX: the case of anycast source? 318 */ 319 if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) || 320 IN6_IS_ADDR_MULTICAST(&oip6->ip6_src)) 321 goto freeit; 322 323 /* 324 * If we are about to send ICMPv6 against ICMPv6 error/redirect, 325 * don't do it. 326 */ 327 nxt = -1; 328 off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt); 329 if (off >= 0 && nxt == IPPROTO_ICMPV6) { 330 struct icmp6_hdr *icp; 331 332 if (m->m_len < off + sizeof(struct icmp6_hdr)) { 333 m = m_pullup(m, off + sizeof(struct icmp6_hdr)); 334 if (m == NULL) { 335 IP6STAT_INC(ip6s_exthdrtoolong); 336 return; 337 } 338 } 339 oip6 = mtod(m, struct ip6_hdr *); 340 icp = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 341 342 if (icp->icmp6_type < ICMP6_ECHO_REQUEST || 343 icp->icmp6_type == ND_REDIRECT) { 344 /* 345 * ICMPv6 error 346 * Special case: for redirect (which is 347 * informational) we must not send icmp6 error. 348 */ 349 ICMP6STAT_INC(icp6s_canterror); 350 goto freeit; 351 } else { 352 /* ICMPv6 informational - send the error */ 353 } 354 } else { 355 /* non-ICMPv6 - send the error */ 356 } 357 358 /* Finally, do rate limitation check. */ 359 if (icmp6_ratelimit(&oip6->ip6_src, type, code)) 360 goto freeit; 361 362 /* 363 * OK, ICMP6 can be generated. 364 */ 365 366 if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN) 367 m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len); 368 369 preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 370 M_PREPEND(m, preplen, M_NOWAIT); /* FIB is also copied over. */ 371 if (m == NULL) { 372 nd6log((LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__)); 373 return; 374 } 375 376 nip6 = mtod(m, struct ip6_hdr *); 377 nip6->ip6_src = oip6->ip6_src; 378 nip6->ip6_dst = oip6->ip6_dst; 379 380 in6_clearscope(&oip6->ip6_src); 381 in6_clearscope(&oip6->ip6_dst); 382 383 icmp6 = (struct icmp6_hdr *)(nip6 + 1); 384 icmp6->icmp6_type = type; 385 icmp6->icmp6_code = code; 386 icmp6->icmp6_pptr = htonl((u_int32_t)param); 387 388 ICMP6STAT_INC2(icp6s_outhist, type); 389 NET_EPOCH_ENTER(et); 390 icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */ 391 NET_EPOCH_EXIT(et); 392 393 return; 394 395 freeit: 396 /* 397 * If we can't tell whether or not we can generate ICMP6, free it. 398 */ 399 m_freem(m); 400 } 401 402 int 403 icmp6_errmap(const struct icmp6_hdr *icmp6) 404 { 405 406 switch (icmp6->icmp6_type) { 407 case ICMP6_DST_UNREACH: 408 switch (icmp6->icmp6_code) { 409 case ICMP6_DST_UNREACH_NOROUTE: 410 case ICMP6_DST_UNREACH_ADDR: 411 return (EHOSTUNREACH); 412 case ICMP6_DST_UNREACH_NOPORT: 413 case ICMP6_DST_UNREACH_ADMIN: 414 return (ECONNREFUSED); 415 case ICMP6_DST_UNREACH_BEYONDSCOPE: 416 return (ENOPROTOOPT); 417 default: 418 return (0); /* Shouldn't happen. */ 419 } 420 case ICMP6_PACKET_TOO_BIG: 421 return (EMSGSIZE); 422 case ICMP6_TIME_EXCEEDED: 423 switch (icmp6->icmp6_code) { 424 case ICMP6_TIME_EXCEED_TRANSIT: 425 return (EHOSTUNREACH); 426 case ICMP6_TIME_EXCEED_REASSEMBLY: 427 return (0); 428 default: 429 return (0); /* Shouldn't happen. */ 430 } 431 case ICMP6_PARAM_PROB: 432 switch (icmp6->icmp6_code) { 433 case ICMP6_PARAMPROB_NEXTHEADER: 434 return (ECONNREFUSED); 435 case ICMP6_PARAMPROB_HEADER: 436 case ICMP6_PARAMPROB_OPTION: 437 return (ENOPROTOOPT); 438 default: 439 return (0); /* Shouldn't happen. */ 440 } 441 default: 442 return (0); 443 } 444 } 445 446 /* 447 * Process a received ICMP6 message. 448 */ 449 int 450 icmp6_input(struct mbuf **mp, int *offp, int proto) 451 { 452 struct mbuf *m, *n; 453 struct ifnet *ifp; 454 struct ip6_hdr *ip6, *nip6; 455 struct icmp6_hdr *icmp6, *nicmp6; 456 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 457 int code, error, icmp6len, ip6len, noff, off, sum; 458 459 NET_EPOCH_ASSERT(); 460 461 m = *mp; 462 off = *offp; 463 464 if (m->m_len < off + sizeof(struct icmp6_hdr)) { 465 m = m_pullup(m, off + sizeof(struct icmp6_hdr)); 466 if (m == NULL) { 467 IP6STAT_INC(ip6s_exthdrtoolong); 468 *mp = m; 469 return (IPPROTO_DONE); 470 } 471 } 472 473 /* 474 * Locate icmp6 structure in mbuf, and check 475 * that not corrupted and of at least minimum length 476 */ 477 478 icmp6len = m->m_pkthdr.len - off; 479 if (icmp6len < sizeof(struct icmp6_hdr)) { 480 ICMP6STAT_INC(icp6s_tooshort); 481 goto freeit; 482 } 483 484 ip6 = mtod(m, struct ip6_hdr *); 485 ifp = m->m_pkthdr.rcvif; 486 /* 487 * Check multicast group membership. 488 * Note: SSM filters are not applied for ICMPv6 traffic. 489 */ 490 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 491 struct in6_multi *inm; 492 493 inm = in6m_lookup(ifp, &ip6->ip6_dst); 494 if (inm == NULL) { 495 IP6STAT_INC(ip6s_notmember); 496 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 497 goto freeit; 498 } 499 } 500 501 /* Calculate the checksum. */ 502 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off); 503 code = icmp6->icmp6_code; 504 if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) { 505 nd6log((LOG_ERR, 506 "ICMP6 checksum error(%d|%x) %s\n", 507 icmp6->icmp6_type, sum, 508 ip6_sprintf(ip6bufs, &ip6->ip6_src))); 509 ICMP6STAT_INC(icp6s_checksum); 510 goto freeit; 511 } 512 513 ICMP6STAT_INC2(icp6s_inhist, icmp6->icmp6_type); 514 icmp6_ifstat_inc(ifp, ifs6_in_msg); 515 if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK) 516 icmp6_ifstat_inc(ifp, ifs6_in_error); 517 518 ip6len = sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen); 519 switch (icmp6->icmp6_type) { 520 case ICMP6_DST_UNREACH: 521 icmp6_ifstat_inc(ifp, ifs6_in_dstunreach); 522 switch (code) { 523 case ICMP6_DST_UNREACH_ADMIN: 524 icmp6_ifstat_inc(ifp, ifs6_in_adminprohib); 525 case ICMP6_DST_UNREACH_NOROUTE: 526 case ICMP6_DST_UNREACH_ADDR: 527 case ICMP6_DST_UNREACH_BEYONDSCOPE: 528 case ICMP6_DST_UNREACH_NOPORT: 529 goto deliver; 530 default: 531 goto badcode; 532 } 533 case ICMP6_PACKET_TOO_BIG: 534 icmp6_ifstat_inc(ifp, ifs6_in_pkttoobig); 535 /* 536 * Validation is made in icmp6_mtudisc_update. 537 * Updating the path MTU will be done after examining 538 * intermediate extension headers. 539 */ 540 goto deliver; 541 case ICMP6_TIME_EXCEEDED: 542 icmp6_ifstat_inc(ifp, ifs6_in_timeexceed); 543 switch (code) { 544 case ICMP6_TIME_EXCEED_TRANSIT: 545 case ICMP6_TIME_EXCEED_REASSEMBLY: 546 goto deliver; 547 default: 548 goto badcode; 549 } 550 case ICMP6_PARAM_PROB: 551 icmp6_ifstat_inc(ifp, ifs6_in_paramprob); 552 switch (code) { 553 case ICMP6_PARAMPROB_NEXTHEADER: 554 case ICMP6_PARAMPROB_HEADER: 555 case ICMP6_PARAMPROB_OPTION: 556 goto deliver; 557 default: 558 goto badcode; 559 } 560 case ICMP6_ECHO_REQUEST: 561 icmp6_ifstat_inc(ifp, ifs6_in_echo); 562 if (code != 0) 563 goto badcode; 564 if (icmp6_ratelimit(&ip6->ip6_src, ICMP6_ECHO_REPLY, 0)) 565 break; 566 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == 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 if (n->m_len < off + sizeof(*nicmp6)) { 605 n = m_pullup(n, off + sizeof(*nicmp6)); 606 if (n == NULL) { 607 IP6STAT_INC(ip6s_exthdrtoolong); 608 break; 609 } 610 } 611 nicmp6 = (struct icmp6_hdr *)(mtod(n, caddr_t) + off); 612 noff = off; 613 } 614 if (n) { 615 nicmp6->icmp6_type = ICMP6_ECHO_REPLY; 616 nicmp6->icmp6_code = 0; 617 ICMP6STAT_INC(icp6s_reflect); 618 ICMP6STAT_INC2(icp6s_outhist, ICMP6_ECHO_REPLY); 619 icmp6_reflect(n, noff); 620 } 621 break; 622 623 case ICMP6_ECHO_REPLY: 624 icmp6_ifstat_inc(ifp, ifs6_in_echoreply); 625 if (code != 0) 626 goto badcode; 627 break; 628 629 case MLD_LISTENER_QUERY: 630 case MLD_LISTENER_REPORT: 631 case MLD_LISTENER_DONE: 632 case MLDV2_LISTENER_REPORT: 633 /* 634 * Drop MLD traffic which is not link-local, has a hop limit 635 * of greater than 1 hop, or which does not have the 636 * IPv6 HBH Router Alert option. 637 * As IPv6 HBH options are stripped in ip6_input() we must 638 * check an mbuf header flag. 639 * XXX Should we also sanity check that these messages 640 * were directed to a link-local multicast prefix? 641 */ 642 if ((ip6->ip6_hlim != 1) || (m->m_flags & M_RTALERT_MLD) == 0) 643 goto freeit; 644 if (mld_input(&m, off, icmp6len) != 0) { 645 *mp = NULL; 646 return (IPPROTO_DONE); 647 } 648 /* m stays. */ 649 break; 650 651 case ICMP6_WRUREQUEST: /* ICMP6_FQDN_QUERY */ 652 { 653 enum { WRU, FQDN } mode; 654 struct prison *pr; 655 656 if (!V_icmp6_nodeinfo) 657 break; 658 659 if (icmp6len == sizeof(struct icmp6_hdr) + 4) 660 mode = WRU; 661 else if (icmp6len >= sizeof(struct icmp6_nodeinfo)) 662 mode = FQDN; 663 else 664 goto badlen; 665 666 pr = NULL; 667 sx_slock(&allprison_lock); 668 TAILQ_FOREACH(pr, &allprison, pr_list) 669 if (pr->pr_vnet == ifp->if_vnet) 670 break; 671 sx_sunlock(&allprison_lock); 672 if (pr == NULL) 673 pr = curthread->td_ucred->cr_prison; 674 if (mode == FQDN) { 675 if (m->m_len < off + sizeof(struct icmp6_nodeinfo)) { 676 m = m_pullup(m, off + 677 sizeof(struct icmp6_nodeinfo)); 678 if (m == NULL) { 679 IP6STAT_INC(ip6s_exthdrtoolong); 680 *mp = m; 681 return (IPPROTO_DONE); 682 } 683 } 684 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 685 if (n) 686 n = ni6_input(n, off, pr); 687 /* XXX meaningless if n == NULL */ 688 noff = sizeof(struct ip6_hdr); 689 } else { 690 u_char *p; 691 int maxhlen, hlen; 692 693 /* 694 * XXX: this combination of flags is pointless, 695 * but should we keep this for compatibility? 696 */ 697 if ((V_icmp6_nodeinfo & (ICMP6_NODEINFO_FQDNOK | 698 ICMP6_NODEINFO_TMPADDROK)) != 699 (ICMP6_NODEINFO_FQDNOK | ICMP6_NODEINFO_TMPADDROK)) 700 break; 701 702 if (code != 0) 703 goto badcode; 704 705 CTASSERT(sizeof(*nip6) + sizeof(*nicmp6) + 4 <= MHLEN); 706 n = m_gethdr(M_NOWAIT, m->m_type); 707 if (n == NULL) { 708 /* Give up remote */ 709 break; 710 } 711 if (!m_dup_pkthdr(n, m, M_NOWAIT)) { 712 /* 713 * Previous code did a blind M_COPY_PKTHDR 714 * and said "just for rcvif". If true, then 715 * we could tolerate the dup failing (due to 716 * the deep copy of the tag chain). For now 717 * be conservative and just fail. 718 */ 719 m_free(n); 720 n = NULL; 721 break; 722 } 723 /* 724 * Copy IPv6 and ICMPv6 only. 725 */ 726 nip6 = mtod(n, struct ip6_hdr *); 727 bcopy(ip6, nip6, sizeof(struct ip6_hdr)); 728 nicmp6 = (struct icmp6_hdr *)(nip6 + 1); 729 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr)); 730 p = (u_char *)(nicmp6 + 1); 731 bzero(p, 4); 732 733 maxhlen = M_TRAILINGSPACE(n) - 734 (sizeof(*nip6) + sizeof(*nicmp6) + 4); 735 mtx_lock(&pr->pr_mtx); 736 hlen = strlen(pr->pr_hostname); 737 if (maxhlen > hlen) 738 maxhlen = hlen; 739 /* meaningless TTL */ 740 bcopy(pr->pr_hostname, p + 4, maxhlen); 741 mtx_unlock(&pr->pr_mtx); 742 noff = sizeof(struct ip6_hdr); 743 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + 744 sizeof(struct icmp6_hdr) + 4 + maxhlen; 745 nicmp6->icmp6_type = ICMP6_WRUREPLY; 746 nicmp6->icmp6_code = 0; 747 } 748 if (n) { 749 ICMP6STAT_INC(icp6s_reflect); 750 ICMP6STAT_INC2(icp6s_outhist, ICMP6_WRUREPLY); 751 icmp6_reflect(n, noff); 752 } 753 break; 754 } 755 756 case ICMP6_WRUREPLY: 757 if (code != 0) 758 goto badcode; 759 break; 760 761 case ND_ROUTER_SOLICIT: 762 icmp6_ifstat_inc(ifp, ifs6_in_routersolicit); 763 if (code != 0) 764 goto badcode; 765 if (icmp6len < sizeof(struct nd_router_solicit)) 766 goto badlen; 767 if (send_sendso_input_hook != NULL) { 768 if (m->m_len < off + icmp6len) { 769 m = m_pullup(m, off + icmp6len); 770 if (m == NULL) { 771 IP6STAT_INC(ip6s_exthdrtoolong); 772 *mp = NULL; 773 return (IPPROTO_DONE); 774 } 775 } 776 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 777 if (error == 0) { 778 m = NULL; 779 goto freeit; 780 } 781 } 782 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 783 nd6_rs_input(m, off, icmp6len); 784 m = n; 785 if (m == NULL) 786 goto freeit; 787 break; 788 789 case ND_ROUTER_ADVERT: 790 icmp6_ifstat_inc(ifp, ifs6_in_routeradvert); 791 if (code != 0) 792 goto badcode; 793 if (icmp6len < sizeof(struct nd_router_advert)) 794 goto badlen; 795 if (send_sendso_input_hook != NULL) { 796 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 797 if (error == 0) { 798 m = NULL; 799 goto freeit; 800 } 801 } 802 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 803 nd6_ra_input(m, off, icmp6len); 804 m = n; 805 if (m == NULL) 806 goto freeit; 807 break; 808 809 case ND_NEIGHBOR_SOLICIT: 810 icmp6_ifstat_inc(ifp, ifs6_in_neighborsolicit); 811 if (code != 0) 812 goto badcode; 813 if (icmp6len < sizeof(struct nd_neighbor_solicit)) 814 goto badlen; 815 if (send_sendso_input_hook != NULL) { 816 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 817 if (error == 0) { 818 m = NULL; 819 goto freeit; 820 } 821 } 822 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 823 nd6_ns_input(m, off, icmp6len); 824 m = n; 825 if (m == NULL) 826 goto freeit; 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 (send_sendso_input_hook != NULL) { 836 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 837 if (error == 0) { 838 m = NULL; 839 goto freeit; 840 } 841 } 842 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 843 nd6_na_input(m, off, icmp6len); 844 m = n; 845 if (m == NULL) 846 goto freeit; 847 break; 848 849 case ND_REDIRECT: 850 icmp6_ifstat_inc(ifp, ifs6_in_redirect); 851 if (code != 0) 852 goto badcode; 853 if (icmp6len < sizeof(struct nd_redirect)) 854 goto badlen; 855 if (send_sendso_input_hook != NULL) { 856 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 857 if (error == 0) { 858 m = NULL; 859 goto freeit; 860 } 861 } 862 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 863 icmp6_redirect_input(m, off); 864 m = n; 865 if (m == NULL) 866 goto freeit; 867 break; 868 869 case ICMP6_ROUTER_RENUMBERING: 870 if (code != ICMP6_ROUTER_RENUMBERING_COMMAND && 871 code != ICMP6_ROUTER_RENUMBERING_RESULT) 872 goto badcode; 873 if (icmp6len < sizeof(struct icmp6_router_renum)) 874 goto badlen; 875 break; 876 877 default: 878 nd6log((LOG_DEBUG, 879 "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n", 880 icmp6->icmp6_type, ip6_sprintf(ip6bufs, &ip6->ip6_src), 881 ip6_sprintf(ip6bufd, &ip6->ip6_dst), 882 ifp ? ifp->if_index : 0)); 883 if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) { 884 /* ICMPv6 error: MUST deliver it by spec... */ 885 goto deliver; 886 } else { 887 /* ICMPv6 informational: MUST not deliver */ 888 break; 889 } 890 deliver: 891 if (icmp6_notify_error(&m, off, icmp6len) != 0) { 892 /* In this case, m should've been freed. */ 893 *mp = NULL; 894 return (IPPROTO_DONE); 895 } 896 break; 897 898 badcode: 899 ICMP6STAT_INC(icp6s_badcode); 900 break; 901 902 badlen: 903 ICMP6STAT_INC(icp6s_badlen); 904 break; 905 } 906 907 /* deliver the packet to appropriate sockets */ 908 icmp6_rip6_input(&m, *offp); 909 910 *mp = m; 911 return (IPPROTO_DONE); 912 913 freeit: 914 m_freem(m); 915 *mp = NULL; 916 return (IPPROTO_DONE); 917 } 918 919 static int 920 icmp6_notify_error(struct mbuf **mp, int off, int icmp6len) 921 { 922 struct mbuf *m; 923 struct icmp6_hdr *icmp6; 924 struct ip6_hdr *eip6; 925 u_int32_t notifymtu; 926 struct sockaddr_in6 icmp6src, icmp6dst; 927 928 m = *mp; 929 930 if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) { 931 ICMP6STAT_INC(icp6s_tooshort); 932 goto freeit; 933 } 934 935 if (m->m_len < off + sizeof(*icmp6) + sizeof(struct ip6_hdr)) { 936 m = m_pullup(m, off + sizeof(*icmp6) + sizeof(struct ip6_hdr)); 937 if (m == NULL) { 938 IP6STAT_INC(ip6s_exthdrtoolong); 939 *mp = m; 940 return (-1); 941 } 942 } 943 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 944 eip6 = (struct ip6_hdr *)(icmp6 + 1); 945 bzero(&icmp6dst, sizeof(icmp6dst)); 946 947 /* Detect the upper level protocol */ 948 { 949 u_int8_t nxt = eip6->ip6_nxt; 950 int eoff = off + sizeof(struct icmp6_hdr) + 951 sizeof(struct ip6_hdr); 952 struct ip6ctlparam ip6cp; 953 int icmp6type = icmp6->icmp6_type; 954 struct ip6_frag *fh; 955 struct ip6_rthdr *rth; 956 struct ip6_rthdr0 *rth0; 957 int rthlen; 958 959 while (1) { /* XXX: should avoid infinite loop explicitly? */ 960 struct ip6_ext *eh; 961 962 switch (nxt) { 963 case IPPROTO_HOPOPTS: 964 case IPPROTO_DSTOPTS: 965 case IPPROTO_AH: 966 if (m->m_len < eoff + sizeof(struct ip6_ext)) { 967 m = m_pullup(m, eoff + 968 sizeof(struct ip6_ext)); 969 if (m == NULL) { 970 IP6STAT_INC(ip6s_exthdrtoolong); 971 *mp = m; 972 return (-1); 973 } 974 } 975 eh = (struct ip6_ext *) 976 (mtod(m, caddr_t) + eoff); 977 if (nxt == IPPROTO_AH) 978 eoff += (eh->ip6e_len + 2) << 2; 979 else 980 eoff += (eh->ip6e_len + 1) << 3; 981 nxt = eh->ip6e_nxt; 982 break; 983 case IPPROTO_ROUTING: 984 /* 985 * When the erroneous packet contains a 986 * routing header, we should examine the 987 * header to determine the final destination. 988 * Otherwise, we can't properly update 989 * information that depends on the final 990 * destination (e.g. path MTU). 991 */ 992 if (m->m_len < eoff + sizeof(*rth)) { 993 m = m_pullup(m, eoff + sizeof(*rth)); 994 if (m == NULL) { 995 IP6STAT_INC(ip6s_exthdrtoolong); 996 *mp = m; 997 return (-1); 998 } 999 } 1000 rth = (struct ip6_rthdr *) 1001 (mtod(m, caddr_t) + eoff); 1002 rthlen = (rth->ip6r_len + 1) << 3; 1003 /* 1004 * XXX: currently there is no 1005 * officially defined type other 1006 * than type-0. 1007 * Note that if the segment left field 1008 * is 0, all intermediate hops must 1009 * have been passed. 1010 */ 1011 if (rth->ip6r_segleft && 1012 rth->ip6r_type == IPV6_RTHDR_TYPE_0) { 1013 int hops; 1014 1015 if (m->m_len < eoff + rthlen) { 1016 m = m_pullup(m, eoff + rthlen); 1017 if (m == NULL) { 1018 IP6STAT_INC( 1019 ip6s_exthdrtoolong); 1020 *mp = m; 1021 return (-1); 1022 } 1023 } 1024 rth0 = (struct ip6_rthdr0 *) 1025 (mtod(m, caddr_t) + eoff); 1026 1027 /* just ignore a bogus header */ 1028 if ((rth0->ip6r0_len % 2) == 0 && 1029 (hops = rth0->ip6r0_len/2)) 1030 icmp6dst.sin6_addr = *((struct in6_addr *)(rth0 + 1) + (hops - 1)); 1031 } 1032 eoff += rthlen; 1033 nxt = rth->ip6r_nxt; 1034 break; 1035 case IPPROTO_FRAGMENT: 1036 if (m->m_len < eoff + sizeof(struct ip6_frag)) { 1037 m = m_pullup(m, eoff + 1038 sizeof(struct ip6_frag)); 1039 if (m == NULL) { 1040 IP6STAT_INC(ip6s_exthdrtoolong); 1041 *mp = m; 1042 return (-1); 1043 } 1044 } 1045 fh = (struct ip6_frag *)(mtod(m, caddr_t) + 1046 eoff); 1047 /* 1048 * Data after a fragment header is meaningless 1049 * unless it is the first fragment, but 1050 * we'll go to the notify label for path MTU 1051 * discovery. 1052 */ 1053 if (fh->ip6f_offlg & IP6F_OFF_MASK) 1054 goto notify; 1055 1056 eoff += sizeof(struct ip6_frag); 1057 nxt = fh->ip6f_nxt; 1058 break; 1059 default: 1060 /* 1061 * This case includes ESP and the No Next 1062 * Header. In such cases going to the notify 1063 * label does not have any meaning 1064 * (i.e. ctlfunc will be NULL), but we go 1065 * anyway since we might have to update 1066 * path MTU information. 1067 */ 1068 goto notify; 1069 } 1070 } 1071 notify: 1072 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 1073 1074 /* 1075 * retrieve parameters from the inner IPv6 header, and convert 1076 * them into sockaddr structures. 1077 * XXX: there is no guarantee that the source or destination 1078 * addresses of the inner packet are in the same scope as 1079 * the addresses of the icmp packet. But there is no other 1080 * way to determine the zone. 1081 */ 1082 eip6 = (struct ip6_hdr *)(icmp6 + 1); 1083 1084 /* 1085 * Protocol layers can't do anything useful with unspecified 1086 * addresses. 1087 */ 1088 if (IN6_IS_ADDR_UNSPECIFIED(&eip6->ip6_src) || 1089 IN6_IS_ADDR_UNSPECIFIED(&eip6->ip6_dst)) 1090 goto freeit; 1091 1092 icmp6dst.sin6_len = sizeof(struct sockaddr_in6); 1093 icmp6dst.sin6_family = AF_INET6; 1094 if (IN6_IS_ADDR_UNSPECIFIED(&icmp6dst.sin6_addr)) 1095 icmp6dst.sin6_addr = eip6->ip6_dst; 1096 if (in6_setscope(&icmp6dst.sin6_addr, m->m_pkthdr.rcvif, NULL)) 1097 goto freeit; 1098 bzero(&icmp6src, sizeof(icmp6src)); 1099 icmp6src.sin6_len = sizeof(struct sockaddr_in6); 1100 icmp6src.sin6_family = AF_INET6; 1101 icmp6src.sin6_addr = eip6->ip6_src; 1102 if (in6_setscope(&icmp6src.sin6_addr, m->m_pkthdr.rcvif, NULL)) 1103 goto freeit; 1104 icmp6src.sin6_flowinfo = 1105 (eip6->ip6_flow & IPV6_FLOWLABEL_MASK); 1106 1107 ip6cp.ip6c_m = m; 1108 ip6cp.ip6c_icmp6 = icmp6; 1109 ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1); 1110 ip6cp.ip6c_off = eoff; 1111 ip6cp.ip6c_finaldst = &icmp6dst; 1112 ip6cp.ip6c_src = &icmp6src; 1113 ip6cp.ip6c_nxt = nxt; 1114 1115 if (icmp6type == ICMP6_PACKET_TOO_BIG) { 1116 notifymtu = ntohl(icmp6->icmp6_mtu); 1117 ip6cp.ip6c_cmdarg = (void *)¬ifymtu; 1118 icmp6_mtudisc_update(&ip6cp); 1119 } 1120 1121 if (ip6_ctlprotox[nxt] != NULL) 1122 ip6_ctlprotox[nxt](&ip6cp); 1123 } 1124 *mp = m; 1125 return (0); 1126 1127 freeit: 1128 m_freem(m); 1129 *mp = NULL; 1130 return (-1); 1131 } 1132 1133 static void 1134 icmp6_mtudisc_update(struct ip6ctlparam *ip6cp) 1135 { 1136 struct in6_addr *dst = &ip6cp->ip6c_finaldst->sin6_addr; 1137 struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6; 1138 struct mbuf *m = ip6cp->ip6c_m; 1139 u_int mtu = ntohl(icmp6->icmp6_mtu); 1140 struct in_conninfo inc; 1141 uint32_t max_mtu; 1142 1143 if (mtu < IPV6_MMTU) 1144 return; 1145 1146 bzero(&inc, sizeof(inc)); 1147 inc.inc_fibnum = M_GETFIB(m); 1148 inc.inc_flags |= INC_ISIPV6; 1149 inc.inc6_faddr = *dst; 1150 if (in6_setscope(&inc.inc6_faddr, m->m_pkthdr.rcvif, NULL)) 1151 return; 1152 1153 max_mtu = tcp_hc_getmtu(&inc); 1154 if (max_mtu == 0) 1155 max_mtu = tcp_maxmtu6(&inc, NULL); 1156 1157 if (mtu < max_mtu) { 1158 tcp_hc_updatemtu(&inc, mtu); 1159 ICMP6STAT_INC(icp6s_pmtuchg); 1160 } 1161 } 1162 1163 /* 1164 * Process a Node Information Query packet, based on 1165 * draft-ietf-ipngwg-icmp-name-lookups-07. 1166 * 1167 * Spec incompatibilities: 1168 * - IPv6 Subject address handling 1169 * - IPv4 Subject address handling support missing 1170 * - Proxy reply (answer even if it's not for me) 1171 * - joins NI group address at in6_ifattach() time only, does not cope 1172 * with hostname changes by sethostname(3) 1173 */ 1174 static struct mbuf * 1175 ni6_input(struct mbuf *m, int off, struct prison *pr) 1176 { 1177 struct icmp6_nodeinfo *ni6, *nni6; 1178 struct mbuf *n = NULL; 1179 u_int16_t qtype; 1180 int subjlen; 1181 int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); 1182 struct ni_reply_fqdn *fqdn; 1183 int addrs; /* for NI_QTYPE_NODEADDR */ 1184 struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */ 1185 struct in6_addr in6_subj; /* subject address */ 1186 struct ip6_hdr *ip6; 1187 int oldfqdn = 0; /* if 1, return pascal string (03 draft) */ 1188 char *subj = NULL; 1189 struct in6_ifaddr *ia6 = NULL; 1190 1191 ip6 = mtod(m, struct ip6_hdr *); 1192 ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off); 1193 1194 /* 1195 * Validate IPv6 source address. 1196 * The default configuration MUST be to refuse answering queries from 1197 * global-scope addresses according to RFC4602. 1198 * Notes: 1199 * - it's not very clear what "refuse" means; this implementation 1200 * simply drops it. 1201 * - it's not very easy to identify global-scope (unicast) addresses 1202 * since there are many prefixes for them. It should be safer 1203 * and in practice sufficient to check "all" but loopback and 1204 * link-local (note that site-local unicast was deprecated and 1205 * ULA is defined as global scope-wise) 1206 */ 1207 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_GLOBALOK) == 0 && 1208 !IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) && 1209 !IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) 1210 goto bad; 1211 1212 /* 1213 * Validate IPv6 destination address. 1214 * 1215 * The Responder must discard the Query without further processing 1216 * unless it is one of the Responder's unicast or anycast addresses, or 1217 * a link-local scope multicast address which the Responder has joined. 1218 * [RFC4602, Section 5.] 1219 */ 1220 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 1221 if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst)) 1222 goto bad; 1223 /* else it's a link-local multicast, fine */ 1224 } else { /* unicast or anycast */ 1225 ia6 = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */, false); 1226 if (ia6 == NULL) 1227 goto bad; /* XXX impossible */ 1228 1229 if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) && 1230 !(V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK)) { 1231 nd6log((LOG_DEBUG, "ni6_input: ignore node info to " 1232 "a temporary address in %s:%d", 1233 __FILE__, __LINE__)); 1234 goto bad; 1235 } 1236 } 1237 1238 /* validate query Subject field. */ 1239 qtype = ntohs(ni6->ni_qtype); 1240 subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo); 1241 switch (qtype) { 1242 case NI_QTYPE_NOOP: 1243 case NI_QTYPE_SUPTYPES: 1244 /* 07 draft */ 1245 if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0) 1246 break; 1247 /* FALLTHROUGH */ 1248 case NI_QTYPE_FQDN: 1249 case NI_QTYPE_NODEADDR: 1250 case NI_QTYPE_IPV4ADDR: 1251 switch (ni6->ni_code) { 1252 case ICMP6_NI_SUBJ_IPV6: 1253 #if ICMP6_NI_SUBJ_IPV6 != 0 1254 case 0: 1255 #endif 1256 /* 1257 * backward compatibility - try to accept 03 draft 1258 * format, where no Subject is present. 1259 */ 1260 if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 && 1261 subjlen == 0) { 1262 oldfqdn++; 1263 break; 1264 } 1265 #if ICMP6_NI_SUBJ_IPV6 != 0 1266 if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6) 1267 goto bad; 1268 #endif 1269 1270 if (subjlen != sizeof(struct in6_addr)) 1271 goto bad; 1272 1273 /* 1274 * Validate Subject address. 1275 * 1276 * Not sure what exactly "address belongs to the node" 1277 * means in the spec, is it just unicast, or what? 1278 * 1279 * At this moment we consider Subject address as 1280 * "belong to the node" if the Subject address equals 1281 * to the IPv6 destination address; validation for 1282 * IPv6 destination address should have done enough 1283 * check for us. 1284 * 1285 * We do not do proxy at this moment. 1286 */ 1287 m_copydata(m, off + sizeof(struct icmp6_nodeinfo), 1288 subjlen, (caddr_t)&in6_subj); 1289 if (in6_setscope(&in6_subj, m->m_pkthdr.rcvif, NULL)) 1290 goto bad; 1291 1292 subj = (char *)&in6_subj; 1293 if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &in6_subj)) 1294 break; 1295 1296 /* 1297 * XXX if we are to allow other cases, we should really 1298 * be careful about scope here. 1299 * basically, we should disallow queries toward IPv6 1300 * destination X with subject Y, 1301 * if scope(X) > scope(Y). 1302 * if we allow scope(X) > scope(Y), it will result in 1303 * information leakage across scope boundary. 1304 */ 1305 goto bad; 1306 1307 case ICMP6_NI_SUBJ_FQDN: 1308 /* 1309 * Validate Subject name with gethostname(3). 1310 * 1311 * The behavior may need some debate, since: 1312 * - we are not sure if the node has FQDN as 1313 * hostname (returned by gethostname(3)). 1314 * - the code does wildcard match for truncated names. 1315 * however, we are not sure if we want to perform 1316 * wildcard match, if gethostname(3) side has 1317 * truncated hostname. 1318 */ 1319 mtx_lock(&pr->pr_mtx); 1320 n = ni6_nametodns(pr->pr_hostname, 1321 strlen(pr->pr_hostname), 0); 1322 mtx_unlock(&pr->pr_mtx); 1323 if (!n || n->m_next || n->m_len == 0) 1324 goto bad; 1325 if (m->m_len < off + sizeof(struct icmp6_nodeinfo) + 1326 subjlen) { 1327 m = m_pullup(m, off + 1328 sizeof(struct icmp6_nodeinfo) + subjlen); 1329 if (m == NULL) { 1330 IP6STAT_INC(ip6s_exthdrtoolong); 1331 goto bad; 1332 } 1333 } 1334 /* ip6 possibly invalid but not used after. */ 1335 ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off); 1336 subj = (char *)(mtod(m, caddr_t) + off + 1337 sizeof(struct icmp6_nodeinfo)); 1338 if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *), 1339 n->m_len)) { 1340 goto bad; 1341 } 1342 m_freem(n); 1343 n = NULL; 1344 break; 1345 1346 case ICMP6_NI_SUBJ_IPV4: /* XXX: to be implemented? */ 1347 default: 1348 goto bad; 1349 } 1350 break; 1351 } 1352 1353 /* refuse based on configuration. XXX ICMP6_NI_REFUSED? */ 1354 switch (qtype) { 1355 case NI_QTYPE_FQDN: 1356 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_FQDNOK) == 0) 1357 goto bad; 1358 break; 1359 case NI_QTYPE_NODEADDR: 1360 case NI_QTYPE_IPV4ADDR: 1361 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_NODEADDROK) == 0) 1362 goto bad; 1363 break; 1364 } 1365 1366 /* guess reply length */ 1367 switch (qtype) { 1368 case NI_QTYPE_NOOP: 1369 break; /* no reply data */ 1370 case NI_QTYPE_SUPTYPES: 1371 replylen += sizeof(u_int32_t); 1372 break; 1373 case NI_QTYPE_FQDN: 1374 /* XXX will append an mbuf */ 1375 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); 1376 break; 1377 case NI_QTYPE_NODEADDR: 1378 addrs = ni6_addrs(ni6, m, &ifp, (struct in6_addr *)subj); 1379 if ((replylen += addrs * (sizeof(struct in6_addr) + 1380 sizeof(u_int32_t))) > MCLBYTES) 1381 replylen = MCLBYTES; /* XXX: will truncate pkt later */ 1382 break; 1383 case NI_QTYPE_IPV4ADDR: 1384 /* unsupported - should respond with unknown Qtype? */ 1385 break; 1386 default: 1387 /* 1388 * XXX: We must return a reply with the ICMP6 code 1389 * `unknown Qtype' in this case. However we regard the case 1390 * as an FQDN query for backward compatibility. 1391 * Older versions set a random value to this field, 1392 * so it rarely varies in the defined qtypes. 1393 * But the mechanism is not reliable... 1394 * maybe we should obsolete older versions. 1395 */ 1396 qtype = NI_QTYPE_FQDN; 1397 /* XXX will append an mbuf */ 1398 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); 1399 oldfqdn++; 1400 break; 1401 } 1402 1403 /* Allocate an mbuf to reply. */ 1404 if (replylen > MCLBYTES) { 1405 /* 1406 * XXX: should we try to allocate more? But MCLBYTES 1407 * is probably much larger than IPV6_MMTU... 1408 */ 1409 goto bad; 1410 } 1411 if (replylen > MHLEN) 1412 n = m_getcl(M_NOWAIT, m->m_type, M_PKTHDR); 1413 else 1414 n = m_gethdr(M_NOWAIT, m->m_type); 1415 if (n == NULL) { 1416 m_freem(m); 1417 return (NULL); 1418 } 1419 m_move_pkthdr(n, m); /* just for recvif and FIB */ 1420 n->m_pkthdr.len = n->m_len = replylen; 1421 1422 /* copy mbuf header and IPv6 + Node Information base headers */ 1423 bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr)); 1424 nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1); 1425 bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo)); 1426 1427 /* qtype dependent procedure */ 1428 switch (qtype) { 1429 case NI_QTYPE_NOOP: 1430 nni6->ni_code = ICMP6_NI_SUCCESS; 1431 nni6->ni_flags = 0; 1432 break; 1433 case NI_QTYPE_SUPTYPES: 1434 { 1435 u_int32_t v; 1436 nni6->ni_code = ICMP6_NI_SUCCESS; 1437 nni6->ni_flags = htons(0x0000); /* raw bitmap */ 1438 /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */ 1439 v = (u_int32_t)htonl(0x0000000f); 1440 bcopy(&v, nni6 + 1, sizeof(u_int32_t)); 1441 break; 1442 } 1443 case NI_QTYPE_FQDN: 1444 nni6->ni_code = ICMP6_NI_SUCCESS; 1445 fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) + 1446 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo)); 1447 nni6->ni_flags = 0; /* XXX: meaningless TTL */ 1448 fqdn->ni_fqdn_ttl = 0; /* ditto. */ 1449 /* 1450 * XXX do we really have FQDN in hostname? 1451 */ 1452 mtx_lock(&pr->pr_mtx); 1453 n->m_next = ni6_nametodns(pr->pr_hostname, 1454 strlen(pr->pr_hostname), oldfqdn); 1455 mtx_unlock(&pr->pr_mtx); 1456 if (n->m_next == NULL) 1457 goto bad; 1458 /* XXX we assume that n->m_next is not a chain */ 1459 if (n->m_next->m_next != NULL) 1460 goto bad; 1461 n->m_pkthdr.len += n->m_next->m_len; 1462 break; 1463 case NI_QTYPE_NODEADDR: 1464 { 1465 int lenlim, copied; 1466 1467 nni6->ni_code = ICMP6_NI_SUCCESS; 1468 n->m_pkthdr.len = n->m_len = 1469 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); 1470 lenlim = M_TRAILINGSPACE(n); 1471 copied = ni6_store_addrs(ni6, nni6, ifp, lenlim); 1472 /* XXX: reset mbuf length */ 1473 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + 1474 sizeof(struct icmp6_nodeinfo) + copied; 1475 break; 1476 } 1477 default: 1478 break; /* XXX impossible! */ 1479 } 1480 1481 nni6->ni_type = ICMP6_NI_REPLY; 1482 m_freem(m); 1483 return (n); 1484 1485 bad: 1486 m_freem(m); 1487 if (n) 1488 m_freem(n); 1489 return (NULL); 1490 } 1491 1492 /* 1493 * make a mbuf with DNS-encoded string. no compression support. 1494 * 1495 * XXX names with less than 2 dots (like "foo" or "foo.section") will be 1496 * treated as truncated name (two \0 at the end). this is a wild guess. 1497 * 1498 * old - return pascal string if non-zero 1499 */ 1500 static struct mbuf * 1501 ni6_nametodns(const char *name, int namelen, int old) 1502 { 1503 struct mbuf *m; 1504 char *cp, *ep; 1505 const char *p, *q; 1506 int i, len, nterm; 1507 1508 if (old) 1509 len = namelen + 1; 1510 else 1511 len = MCLBYTES; 1512 1513 /* Because MAXHOSTNAMELEN is usually 256, we use cluster mbuf. */ 1514 if (len > MLEN) 1515 m = m_getcl(M_NOWAIT, MT_DATA, 0); 1516 else 1517 m = m_get(M_NOWAIT, MT_DATA); 1518 if (m == NULL) 1519 goto fail; 1520 1521 if (old) { 1522 m->m_len = len; 1523 *mtod(m, char *) = namelen; 1524 bcopy(name, mtod(m, char *) + 1, namelen); 1525 return m; 1526 } else { 1527 m->m_len = 0; 1528 cp = mtod(m, char *); 1529 ep = mtod(m, char *) + M_TRAILINGSPACE(m); 1530 1531 /* if not certain about my name, return empty buffer */ 1532 if (namelen == 0) 1533 return m; 1534 1535 /* 1536 * guess if it looks like shortened hostname, or FQDN. 1537 * shortened hostname needs two trailing "\0". 1538 */ 1539 i = 0; 1540 for (p = name; p < name + namelen; p++) { 1541 if (*p && *p == '.') 1542 i++; 1543 } 1544 if (i < 2) 1545 nterm = 2; 1546 else 1547 nterm = 1; 1548 1549 p = name; 1550 while (cp < ep && p < name + namelen) { 1551 i = 0; 1552 for (q = p; q < name + namelen && *q && *q != '.'; q++) 1553 i++; 1554 /* result does not fit into mbuf */ 1555 if (cp + i + 1 >= ep) 1556 goto fail; 1557 /* 1558 * DNS label length restriction, RFC1035 page 8. 1559 * "i == 0" case is included here to avoid returning 1560 * 0-length label on "foo..bar". 1561 */ 1562 if (i <= 0 || i >= 64) 1563 goto fail; 1564 *cp++ = i; 1565 bcopy(p, cp, i); 1566 cp += i; 1567 p = q; 1568 if (p < name + namelen && *p == '.') 1569 p++; 1570 } 1571 /* termination */ 1572 if (cp + nterm >= ep) 1573 goto fail; 1574 while (nterm-- > 0) 1575 *cp++ = '\0'; 1576 m->m_len = cp - mtod(m, char *); 1577 return m; 1578 } 1579 1580 panic("should not reach here"); 1581 /* NOTREACHED */ 1582 1583 fail: 1584 if (m) 1585 m_freem(m); 1586 return NULL; 1587 } 1588 1589 /* 1590 * check if two DNS-encoded string matches. takes care of truncated 1591 * form (with \0\0 at the end). no compression support. 1592 * XXX upper/lowercase match (see RFC2065) 1593 */ 1594 static int 1595 ni6_dnsmatch(const char *a, int alen, const char *b, int blen) 1596 { 1597 const char *a0, *b0; 1598 int l; 1599 1600 /* simplest case - need validation? */ 1601 if (alen == blen && bcmp(a, b, alen) == 0) 1602 return 1; 1603 1604 a0 = a; 1605 b0 = b; 1606 1607 /* termination is mandatory */ 1608 if (alen < 2 || blen < 2) 1609 return 0; 1610 if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0') 1611 return 0; 1612 alen--; 1613 blen--; 1614 1615 while (a - a0 < alen && b - b0 < blen) { 1616 if (a - a0 + 1 > alen || b - b0 + 1 > blen) 1617 return 0; 1618 1619 if ((signed char)a[0] < 0 || (signed char)b[0] < 0) 1620 return 0; 1621 /* we don't support compression yet */ 1622 if (a[0] >= 64 || b[0] >= 64) 1623 return 0; 1624 1625 /* truncated case */ 1626 if (a[0] == 0 && a - a0 == alen - 1) 1627 return 1; 1628 if (b[0] == 0 && b - b0 == blen - 1) 1629 return 1; 1630 if (a[0] == 0 || b[0] == 0) 1631 return 0; 1632 1633 if (a[0] != b[0]) 1634 return 0; 1635 l = a[0]; 1636 if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen) 1637 return 0; 1638 if (bcmp(a + 1, b + 1, l) != 0) 1639 return 0; 1640 1641 a += 1 + l; 1642 b += 1 + l; 1643 } 1644 1645 if (a - a0 == alen && b - b0 == blen) 1646 return 1; 1647 else 1648 return 0; 1649 } 1650 1651 /* 1652 * calculate the number of addresses to be returned in the node info reply. 1653 */ 1654 static int 1655 ni6_addrs(struct icmp6_nodeinfo *ni6, struct mbuf *m, struct ifnet **ifpp, 1656 struct in6_addr *subj) 1657 { 1658 struct ifnet *ifp; 1659 struct in6_ifaddr *ifa6; 1660 struct ifaddr *ifa; 1661 int addrs = 0, addrsofif, iffound = 0; 1662 int niflags = ni6->ni_flags; 1663 1664 NET_EPOCH_ASSERT(); 1665 1666 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) { 1667 switch (ni6->ni_code) { 1668 case ICMP6_NI_SUBJ_IPV6: 1669 if (subj == NULL) /* must be impossible... */ 1670 return (0); 1671 break; 1672 default: 1673 /* 1674 * XXX: we only support IPv6 subject address for 1675 * this Qtype. 1676 */ 1677 return (0); 1678 } 1679 } 1680 1681 CK_STAILQ_FOREACH(ifp, &V_ifnet, if_link) { 1682 addrsofif = 0; 1683 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 1684 if (ifa->ifa_addr->sa_family != AF_INET6) 1685 continue; 1686 ifa6 = (struct in6_ifaddr *)ifa; 1687 1688 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 && 1689 IN6_ARE_ADDR_EQUAL(subj, &ifa6->ia_addr.sin6_addr)) 1690 iffound = 1; 1691 1692 /* 1693 * IPv4-mapped addresses can only be returned by a 1694 * Node Information proxy, since they represent 1695 * addresses of IPv4-only nodes, which perforce do 1696 * not implement this protocol. 1697 * [icmp-name-lookups-07, Section 5.4] 1698 * So we don't support NI_NODEADDR_FLAG_COMPAT in 1699 * this function at this moment. 1700 */ 1701 1702 /* What do we have to do about ::1? */ 1703 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { 1704 case IPV6_ADDR_SCOPE_LINKLOCAL: 1705 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) 1706 continue; 1707 break; 1708 case IPV6_ADDR_SCOPE_SITELOCAL: 1709 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) 1710 continue; 1711 break; 1712 case IPV6_ADDR_SCOPE_GLOBAL: 1713 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) 1714 continue; 1715 break; 1716 default: 1717 continue; 1718 } 1719 1720 /* 1721 * check if anycast is okay. 1722 * XXX: just experimental. not in the spec. 1723 */ 1724 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && 1725 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) 1726 continue; /* we need only unicast addresses */ 1727 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && 1728 (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) { 1729 continue; 1730 } 1731 addrsofif++; /* count the address */ 1732 } 1733 if (iffound) { 1734 *ifpp = ifp; 1735 return (addrsofif); 1736 } 1737 1738 addrs += addrsofif; 1739 } 1740 1741 return (addrs); 1742 } 1743 1744 static int 1745 ni6_store_addrs(struct icmp6_nodeinfo *ni6, struct icmp6_nodeinfo *nni6, 1746 struct ifnet *ifp0, int resid) 1747 { 1748 struct ifnet *ifp; 1749 struct in6_ifaddr *ifa6; 1750 struct ifaddr *ifa; 1751 struct ifnet *ifp_dep = NULL; 1752 int copied = 0, allow_deprecated = 0; 1753 u_char *cp = (u_char *)(nni6 + 1); 1754 int niflags = ni6->ni_flags; 1755 u_int32_t ltime; 1756 1757 NET_EPOCH_ASSERT(); 1758 1759 if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL)) 1760 return (0); /* needless to copy */ 1761 1762 ifp = ifp0 ? ifp0 : CK_STAILQ_FIRST(&V_ifnet); 1763 again: 1764 1765 for (; ifp; ifp = CK_STAILQ_NEXT(ifp, if_link)) { 1766 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 1767 if (ifa->ifa_addr->sa_family != AF_INET6) 1768 continue; 1769 ifa6 = (struct in6_ifaddr *)ifa; 1770 1771 if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 && 1772 allow_deprecated == 0) { 1773 /* 1774 * prefererred address should be put before 1775 * deprecated addresses. 1776 */ 1777 1778 /* record the interface for later search */ 1779 if (ifp_dep == NULL) 1780 ifp_dep = ifp; 1781 1782 continue; 1783 } else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 && 1784 allow_deprecated != 0) 1785 continue; /* we now collect deprecated addrs */ 1786 1787 /* What do we have to do about ::1? */ 1788 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { 1789 case IPV6_ADDR_SCOPE_LINKLOCAL: 1790 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) 1791 continue; 1792 break; 1793 case IPV6_ADDR_SCOPE_SITELOCAL: 1794 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) 1795 continue; 1796 break; 1797 case IPV6_ADDR_SCOPE_GLOBAL: 1798 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) 1799 continue; 1800 break; 1801 default: 1802 continue; 1803 } 1804 1805 /* 1806 * check if anycast is okay. 1807 * XXX: just experimental. not in the spec. 1808 */ 1809 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && 1810 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) 1811 continue; 1812 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && 1813 (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) { 1814 continue; 1815 } 1816 1817 /* now we can copy the address */ 1818 if (resid < sizeof(struct in6_addr) + 1819 sizeof(u_int32_t)) { 1820 /* 1821 * We give up much more copy. 1822 * Set the truncate flag and return. 1823 */ 1824 nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE; 1825 return (copied); 1826 } 1827 1828 /* 1829 * Set the TTL of the address. 1830 * The TTL value should be one of the following 1831 * according to the specification: 1832 * 1833 * 1. The remaining lifetime of a DHCP lease on the 1834 * address, or 1835 * 2. The remaining Valid Lifetime of a prefix from 1836 * which the address was derived through Stateless 1837 * Autoconfiguration. 1838 * 1839 * Note that we currently do not support stateful 1840 * address configuration by DHCPv6, so the former 1841 * case can't happen. 1842 */ 1843 if (ifa6->ia6_lifetime.ia6t_expire == 0) 1844 ltime = ND6_INFINITE_LIFETIME; 1845 else { 1846 if (ifa6->ia6_lifetime.ia6t_expire > 1847 time_uptime) 1848 ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_uptime); 1849 else 1850 ltime = 0; 1851 } 1852 1853 bcopy(<ime, cp, sizeof(u_int32_t)); 1854 cp += sizeof(u_int32_t); 1855 1856 /* copy the address itself */ 1857 bcopy(&ifa6->ia_addr.sin6_addr, cp, 1858 sizeof(struct in6_addr)); 1859 in6_clearscope((struct in6_addr *)cp); /* XXX */ 1860 cp += sizeof(struct in6_addr); 1861 1862 resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t)); 1863 copied += (sizeof(struct in6_addr) + sizeof(u_int32_t)); 1864 } 1865 if (ifp0) /* we need search only on the specified IF */ 1866 break; 1867 } 1868 1869 if (allow_deprecated == 0 && ifp_dep != NULL) { 1870 ifp = ifp_dep; 1871 allow_deprecated = 1; 1872 1873 goto again; 1874 } 1875 1876 return (copied); 1877 } 1878 1879 static bool 1880 icmp6_rip6_match(const struct inpcb *inp, void *v) 1881 { 1882 struct ip6_hdr *ip6 = v; 1883 1884 if ((inp->inp_vflag & INP_IPV6) == 0) 1885 return (false); 1886 if (inp->inp_ip_p != IPPROTO_ICMPV6) 1887 return (false); 1888 if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr) && 1889 !IN6_ARE_ADDR_EQUAL(&inp->in6p_laddr, &ip6->ip6_dst)) 1890 return (false); 1891 if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr) && 1892 !IN6_ARE_ADDR_EQUAL(&inp->in6p_faddr, &ip6->ip6_src)) 1893 return (false); 1894 return (true); 1895 } 1896 1897 /* 1898 * XXX almost dup'ed code with rip6_input. 1899 */ 1900 static int 1901 icmp6_rip6_input(struct mbuf **mp, int off) 1902 { 1903 struct mbuf *n, *m = *mp; 1904 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1905 struct inpcb_iterator inpi = INP_ITERATOR(&V_ripcbinfo, 1906 INPLOOKUP_RLOCKPCB, icmp6_rip6_match, ip6); 1907 struct inpcb *inp; 1908 struct sockaddr_in6 fromsa; 1909 struct icmp6_hdr *icmp6; 1910 struct mbuf *opts = NULL; 1911 int delivered = 0, fib; 1912 1913 /* This is assumed to be safe; icmp6_input() does a pullup. */ 1914 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off); 1915 1916 /* 1917 * XXX: the address may have embedded scope zone ID, which should be 1918 * hidden from applications. 1919 */ 1920 bzero(&fromsa, sizeof(fromsa)); 1921 fromsa.sin6_family = AF_INET6; 1922 fromsa.sin6_len = sizeof(struct sockaddr_in6); 1923 fromsa.sin6_addr = ip6->ip6_src; 1924 if (sa6_recoverscope(&fromsa)) { 1925 m_freem(m); 1926 *mp = NULL; 1927 return (IPPROTO_DONE); 1928 } 1929 1930 fib = M_GETFIB(m); 1931 1932 while ((inp = inp_next(&inpi)) != NULL) { 1933 if (V_rip_bind_all_fibs == 0 && fib != inp->inp_inc.inc_fibnum) 1934 /* 1935 * Sockets bound to a specific FIB can only receive 1936 * packets from that FIB. 1937 */ 1938 continue; 1939 if (ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type, 1940 inp->in6p_icmp6filt)) 1941 continue; 1942 /* 1943 * Recent network drivers tend to allocate a single 1944 * mbuf cluster, rather than to make a couple of 1945 * mbufs without clusters. Also, since the IPv6 code 1946 * path tries to avoid m_pullup(), it is highly 1947 * probable that we still have an mbuf cluster here 1948 * even though the necessary length can be stored in an 1949 * mbuf's internal buffer. 1950 * Meanwhile, the default size of the receive socket 1951 * buffer for raw sockets is not so large. This means 1952 * the possibility of packet loss is relatively higher 1953 * than before. To avoid this scenario, we copy the 1954 * received data to a separate mbuf that does not use 1955 * a cluster, if possible. 1956 * XXX: it is better to copy the data after stripping 1957 * intermediate headers. 1958 */ 1959 if ((m->m_flags & M_EXT) && m->m_next == NULL && 1960 m->m_len <= MHLEN) { 1961 n = m_get(M_NOWAIT, m->m_type); 1962 if (n != NULL) { 1963 if (m_dup_pkthdr(n, m, M_NOWAIT)) { 1964 bcopy(m->m_data, n->m_data, m->m_len); 1965 n->m_len = m->m_len; 1966 } else { 1967 m_free(n); 1968 n = NULL; 1969 } 1970 } 1971 } else 1972 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 1973 if (n == NULL) 1974 continue; 1975 if (inp->inp_flags & INP_CONTROLOPTS) 1976 ip6_savecontrol(inp, n, &opts); 1977 /* strip intermediate headers */ 1978 m_adj(n, off); 1979 SOCKBUF_LOCK(&inp->inp_socket->so_rcv); 1980 if (sbappendaddr_locked(&inp->inp_socket->so_rcv, 1981 (struct sockaddr *)&fromsa, n, opts) == 0) { 1982 soroverflow_locked(inp->inp_socket); 1983 m_freem(n); 1984 if (opts) 1985 m_freem(opts); 1986 } else { 1987 sorwakeup_locked(inp->inp_socket); 1988 delivered++; 1989 } 1990 opts = NULL; 1991 } 1992 m_freem(m); 1993 *mp = NULL; 1994 if (delivered == 0) 1995 IP6STAT_DEC(ip6s_delivered); 1996 return (IPPROTO_DONE); 1997 } 1998 1999 /* 2000 * Reflect the ip6 packet back to the source. 2001 * OFF points to the icmp6 header, counted from the top of the mbuf. 2002 */ 2003 static void 2004 icmp6_reflect(struct mbuf *m, size_t off) 2005 { 2006 struct in6_addr src6, *srcp; 2007 struct ip6_hdr *ip6; 2008 struct icmp6_hdr *icmp6; 2009 struct in6_ifaddr *ia = NULL; 2010 struct ifnet *outif = NULL; 2011 int plen; 2012 int type, code, hlim; 2013 2014 /* too short to reflect */ 2015 if (off < sizeof(struct ip6_hdr)) { 2016 nd6log((LOG_DEBUG, 2017 "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n", 2018 (u_long)off, (u_long)sizeof(struct ip6_hdr), 2019 __FILE__, __LINE__)); 2020 goto bad; 2021 } 2022 2023 /* 2024 * If there are extra headers between IPv6 and ICMPv6, strip 2025 * off that header first. 2026 */ 2027 #ifdef DIAGNOSTIC 2028 if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN) 2029 panic("assumption failed in icmp6_reflect"); 2030 #endif 2031 if (off > sizeof(struct ip6_hdr)) { 2032 size_t l; 2033 struct ip6_hdr nip6; 2034 2035 l = off - sizeof(struct ip6_hdr); 2036 m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6); 2037 m_adj(m, l); 2038 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 2039 if (m->m_len < l) { 2040 if ((m = m_pullup(m, l)) == NULL) 2041 return; 2042 } 2043 bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6)); 2044 } else /* off == sizeof(struct ip6_hdr) */ { 2045 size_t l; 2046 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 2047 if (m->m_len < l) { 2048 if ((m = m_pullup(m, l)) == NULL) 2049 return; 2050 } 2051 } 2052 plen = m->m_pkthdr.len - sizeof(struct ip6_hdr); 2053 ip6 = mtod(m, struct ip6_hdr *); 2054 ip6->ip6_nxt = IPPROTO_ICMPV6; 2055 icmp6 = (struct icmp6_hdr *)(ip6 + 1); 2056 type = icmp6->icmp6_type; /* keep type for statistics */ 2057 code = icmp6->icmp6_code; /* ditto. */ 2058 hlim = 0; 2059 srcp = NULL; 2060 2061 if (__predict_false(IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src))) { 2062 nd6log((LOG_DEBUG, 2063 "icmp6_reflect: source address is unspecified\n")); 2064 goto bad; 2065 } 2066 2067 /* 2068 * If the incoming packet was addressed directly to us (i.e. unicast), 2069 * use dst as the src for the reply. 2070 * The IN6_IFF_NOTREADY case should be VERY rare, but is possible 2071 * (for example) when we encounter an error while forwarding procedure 2072 * destined to a duplicated address of ours. 2073 */ 2074 if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 2075 ia = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */, false); 2076 if (ia != NULL && !(ia->ia6_flags & 2077 (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) { 2078 src6 = ia->ia_addr.sin6_addr; 2079 srcp = &src6; 2080 2081 if (m->m_pkthdr.rcvif != NULL) { 2082 /* XXX: This may not be the outgoing interface */ 2083 hlim = 2084 m->m_pkthdr.rcvif->if_inet6->nd_curhoplimit; 2085 } else 2086 hlim = V_ip6_defhlim; 2087 } 2088 } 2089 2090 if (srcp == NULL) { 2091 int error; 2092 struct in6_addr dst6; 2093 uint32_t scopeid; 2094 2095 /* 2096 * This case matches to multicasts, our anycast, or unicasts 2097 * that we do not own. Select a source address based on the 2098 * source address of the erroneous packet. 2099 */ 2100 in6_splitscope(&ip6->ip6_src, &dst6, &scopeid); 2101 error = in6_selectsrc_addr(M_GETFIB(m), &dst6, 2102 scopeid, NULL, &src6, &hlim); 2103 2104 if (error) { 2105 char ip6buf[INET6_ADDRSTRLEN]; 2106 nd6log((LOG_DEBUG, 2107 "icmp6_reflect: source can't be determined: " 2108 "dst=%s, error=%d\n", 2109 ip6_sprintf(ip6buf, &ip6->ip6_dst), error)); 2110 goto bad; 2111 } 2112 srcp = &src6; 2113 } 2114 /* 2115 * ip6_input() drops a packet if its src is multicast. 2116 * So, the src is never multicast. 2117 */ 2118 ip6->ip6_dst = ip6->ip6_src; 2119 ip6->ip6_src = *srcp; 2120 ip6->ip6_flow = 0; 2121 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2122 ip6->ip6_vfc |= IPV6_VERSION; 2123 ip6->ip6_nxt = IPPROTO_ICMPV6; 2124 ip6->ip6_hlim = hlim; 2125 2126 icmp6->icmp6_cksum = 0; 2127 icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2128 sizeof(struct ip6_hdr), plen); 2129 2130 /* 2131 * XXX option handling 2132 */ 2133 2134 m->m_flags &= ~(M_BCAST|M_MCAST); 2135 m->m_pkthdr.rcvif = NULL; 2136 m->m_pkthdr.csum_flags = 0; 2137 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2138 if (outif) 2139 icmp6_ifoutstat_inc(outif, type, code); 2140 2141 return; 2142 2143 bad: 2144 m_freem(m); 2145 return; 2146 } 2147 2148 static const char * 2149 icmp6_redirect_diag(struct in6_addr *src6, struct in6_addr *dst6, 2150 struct in6_addr *tgt6) 2151 { 2152 static char buf[1024]; 2153 char ip6bufs[INET6_ADDRSTRLEN]; 2154 char ip6bufd[INET6_ADDRSTRLEN]; 2155 char ip6buft[INET6_ADDRSTRLEN]; 2156 snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)", 2157 ip6_sprintf(ip6bufs, src6), ip6_sprintf(ip6bufd, dst6), 2158 ip6_sprintf(ip6buft, tgt6)); 2159 return buf; 2160 } 2161 2162 void 2163 icmp6_redirect_input(struct mbuf *m, int off) 2164 { 2165 struct ifnet *ifp; 2166 struct ip6_hdr *ip6; 2167 struct nd_redirect *nd_rd; 2168 struct in6_addr src6, redtgt6, reddst6; 2169 union nd_opts ndopts; 2170 char ip6buf[INET6_ADDRSTRLEN]; 2171 char *lladdr; 2172 int icmp6len, is_onlink, is_router, lladdrlen; 2173 2174 M_ASSERTPKTHDR(m); 2175 KASSERT(m->m_pkthdr.rcvif != NULL, ("%s: no rcvif", __func__)); 2176 2177 /* XXX if we are router, we don't update route by icmp6 redirect */ 2178 if (V_ip6_forwarding) 2179 goto freeit; 2180 if (!V_icmp6_rediraccept) 2181 goto freeit; 2182 2183 /* RFC 6980: Nodes MUST silently ignore fragments */ 2184 if(m->m_flags & M_FRAGMENTED) 2185 goto freeit; 2186 2187 ip6 = mtod(m, struct ip6_hdr *); 2188 icmp6len = ntohs(ip6->ip6_plen); 2189 if (m->m_len < off + icmp6len) { 2190 m = m_pullup(m, off + icmp6len); 2191 if (m == NULL) { 2192 IP6STAT_INC(ip6s_exthdrtoolong); 2193 return; 2194 } 2195 } 2196 ip6 = mtod(m, struct ip6_hdr *); 2197 nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off); 2198 2199 ifp = m->m_pkthdr.rcvif; 2200 redtgt6 = nd_rd->nd_rd_target; 2201 reddst6 = nd_rd->nd_rd_dst; 2202 2203 if (in6_setscope(&redtgt6, ifp, NULL) || 2204 in6_setscope(&reddst6, ifp, NULL)) { 2205 goto freeit; 2206 } 2207 2208 /* validation */ 2209 src6 = ip6->ip6_src; 2210 if (!IN6_IS_ADDR_LINKLOCAL(&src6)) { 2211 nd6log((LOG_ERR, 2212 "ICMP6 redirect sent from %s rejected; " 2213 "must be from linklocal\n", 2214 ip6_sprintf(ip6buf, &src6))); 2215 goto bad; 2216 } 2217 if (__predict_false(ip6->ip6_hlim != 255)) { 2218 ICMP6STAT_INC(icp6s_invlhlim); 2219 nd6log((LOG_ERR, 2220 "ICMP6 redirect sent from %s rejected; " 2221 "hlim=%d (must be 255)\n", 2222 ip6_sprintf(ip6buf, &src6), ip6->ip6_hlim)); 2223 goto bad; 2224 } 2225 { 2226 /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */ 2227 struct nhop_object *nh; 2228 struct in6_addr kdst; 2229 uint32_t scopeid; 2230 2231 in6_splitscope(&reddst6, &kdst, &scopeid); 2232 NET_EPOCH_ASSERT(); 2233 nh = fib6_lookup(ifp->if_fib, &kdst, scopeid, 0, 0); 2234 if (nh != NULL) { 2235 struct in6_addr nh_addr; 2236 nh_addr = ifatoia6(nh->nh_ifa)->ia_addr.sin6_addr; 2237 if ((nh->nh_flags & NHF_GATEWAY) == 0) { 2238 nd6log((LOG_ERR, 2239 "ICMP6 redirect rejected; no route " 2240 "with inet6 gateway found for redirect dst: %s\n", 2241 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2242 goto bad; 2243 } 2244 2245 /* 2246 * Embed scope zone id into next hop address. 2247 */ 2248 nh_addr = nh->gw6_sa.sin6_addr; 2249 2250 if (IN6_ARE_ADDR_EQUAL(&src6, &nh_addr) == 0) { 2251 nd6log((LOG_ERR, 2252 "ICMP6 redirect rejected; " 2253 "not equal to gw-for-src=%s (must be same): " 2254 "%s\n", 2255 ip6_sprintf(ip6buf, &nh_addr), 2256 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2257 goto bad; 2258 } 2259 } else { 2260 nd6log((LOG_ERR, 2261 "ICMP6 redirect rejected; " 2262 "no route found for redirect dst: %s\n", 2263 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2264 goto bad; 2265 } 2266 } 2267 if (IN6_IS_ADDR_MULTICAST(&reddst6)) { 2268 nd6log((LOG_ERR, 2269 "ICMP6 redirect rejected; " 2270 "redirect dst must be unicast: %s\n", 2271 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2272 goto bad; 2273 } 2274 2275 is_router = is_onlink = 0; 2276 if (IN6_IS_ADDR_LINKLOCAL(&redtgt6)) 2277 is_router = 1; /* router case */ 2278 if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0) 2279 is_onlink = 1; /* on-link destination case */ 2280 if (!is_router && !is_onlink) { 2281 nd6log((LOG_ERR, 2282 "ICMP6 redirect rejected; " 2283 "neither router case nor onlink case: %s\n", 2284 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2285 goto bad; 2286 } 2287 2288 icmp6len -= sizeof(*nd_rd); 2289 nd6_option_init(nd_rd + 1, icmp6len, &ndopts); 2290 if (nd6_options(&ndopts) < 0) { 2291 nd6log((LOG_INFO, "%s: invalid ND option, rejected: %s\n", 2292 __func__, icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2293 /* nd6_options have incremented stats */ 2294 goto freeit; 2295 } 2296 2297 lladdr = NULL; 2298 lladdrlen = 0; 2299 if (ndopts.nd_opts_tgt_lladdr) { 2300 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 2301 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 2302 } 2303 2304 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 2305 nd6log((LOG_INFO, "%s: lladdrlen mismatch for %s " 2306 "(if %d, icmp6 packet %d): %s\n", 2307 __func__, ip6_sprintf(ip6buf, &redtgt6), 2308 ifp->if_addrlen, lladdrlen - 2, 2309 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2310 goto bad; 2311 } 2312 2313 /* Validation passed. */ 2314 2315 /* RFC 2461 8.3 */ 2316 nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT, 2317 is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER); 2318 2319 /* 2320 * Install a gateway route in the better-router case or an interface 2321 * route in the on-link-destination case. 2322 */ 2323 { 2324 struct sockaddr_in6 sdst; 2325 struct sockaddr_in6 sgw; 2326 struct sockaddr_in6 ssrc; 2327 struct sockaddr *gw; 2328 int rt_flags; 2329 u_int fibnum; 2330 2331 bzero(&sdst, sizeof(sdst)); 2332 bzero(&ssrc, sizeof(ssrc)); 2333 sdst.sin6_family = ssrc.sin6_family = AF_INET6; 2334 sdst.sin6_len = ssrc.sin6_len = sizeof(struct sockaddr_in6); 2335 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr)); 2336 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr)); 2337 rt_flags = 0; 2338 if (is_router) { 2339 bzero(&sgw, sizeof(sgw)); 2340 sgw.sin6_family = AF_INET6; 2341 sgw.sin6_len = sizeof(struct sockaddr_in6); 2342 bcopy(&redtgt6, &sgw.sin6_addr, 2343 sizeof(struct in6_addr)); 2344 gw = (struct sockaddr *)&sgw; 2345 rt_flags |= RTF_GATEWAY; 2346 } else 2347 gw = ifp->if_addr->ifa_addr; 2348 for (fibnum = 0; fibnum < rt_numfibs; fibnum++) 2349 rib_add_redirect(fibnum, (struct sockaddr *)&sdst, gw, 2350 (struct sockaddr *)&ssrc, ifp, rt_flags, 2351 V_icmp6_redirtimeout); 2352 } 2353 2354 freeit: 2355 m_freem(m); 2356 return; 2357 2358 bad: 2359 ICMP6STAT_INC(icp6s_badredirect); 2360 m_freem(m); 2361 } 2362 2363 void 2364 icmp6_redirect_output(struct mbuf *m0, struct nhop_object *nh) 2365 { 2366 struct ifnet *ifp; /* my outgoing interface */ 2367 struct in6_addr ifp_ll6; 2368 struct in6_addr *router_ll6; 2369 struct ip6_hdr *sip6; /* m0 as struct ip6_hdr */ 2370 struct mbuf *m = NULL; /* newly allocated one */ 2371 struct m_tag *mtag; 2372 struct ip6_hdr *ip6; /* m as struct ip6_hdr */ 2373 struct nd_redirect *nd_rd; 2374 struct llentry *ln = NULL; 2375 size_t maxlen; 2376 u_char *p; 2377 struct ifnet *outif = NULL; 2378 struct sockaddr_in6 src_sa; 2379 2380 icmp6_errcount(ND_REDIRECT, 0); 2381 2382 /* if we are not router, we don't send icmp6 redirect */ 2383 if (!V_ip6_forwarding) 2384 goto fail; 2385 2386 /* sanity check */ 2387 if (!m0 || !nh || !(NH_IS_VALID(nh)) || !(ifp = nh->nh_ifp)) 2388 goto fail; 2389 2390 /* 2391 * Address check: 2392 * the source address must identify a neighbor, and 2393 * the destination address must not be a multicast address 2394 * [RFC 2461, sec 8.2] 2395 */ 2396 sip6 = mtod(m0, struct ip6_hdr *); 2397 bzero(&src_sa, sizeof(src_sa)); 2398 src_sa.sin6_family = AF_INET6; 2399 src_sa.sin6_len = sizeof(src_sa); 2400 src_sa.sin6_addr = sip6->ip6_src; 2401 if (nd6_is_addr_neighbor(&src_sa, ifp) == 0) 2402 goto fail; 2403 if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst)) 2404 goto fail; /* what should we do here? */ 2405 2406 /* rate limit */ 2407 if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0)) 2408 goto fail; 2409 2410 /* 2411 * Since we are going to append up to 1280 bytes (= IPV6_MMTU), 2412 * we almost always ask for an mbuf cluster for simplicity. 2413 * (MHLEN < IPV6_MMTU is almost always true) 2414 */ 2415 #if IPV6_MMTU >= MCLBYTES 2416 # error assumption failed about IPV6_MMTU and MCLBYTES 2417 #endif 2418 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 2419 if (m == NULL) 2420 goto fail; 2421 M_SETFIB(m, M_GETFIB(m0)); 2422 maxlen = M_TRAILINGSPACE(m); 2423 maxlen = min(IPV6_MMTU, maxlen); 2424 /* just for safety */ 2425 if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) + 2426 ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) { 2427 goto fail; 2428 } 2429 2430 { 2431 /* get ip6 linklocal address for ifp(my outgoing interface). */ 2432 struct in6_ifaddr *ia; 2433 if ((ia = in6ifa_ifpforlinklocal(ifp, 2434 IN6_IFF_NOTREADY| 2435 IN6_IFF_ANYCAST)) == NULL) 2436 goto fail; 2437 bcopy(&ia->ia_addr.sin6_addr, &ifp_ll6, sizeof(ifp_ll6)); 2438 ifa_free(&ia->ia_ifa); 2439 } 2440 2441 /* get ip6 linklocal address for the router. */ 2442 if (nh->nh_flags & NHF_GATEWAY) { 2443 struct sockaddr_in6 *sin6; 2444 sin6 = &nh->gw6_sa; 2445 router_ll6 = &sin6->sin6_addr; 2446 if (!IN6_IS_ADDR_LINKLOCAL(router_ll6)) 2447 router_ll6 = (struct in6_addr *)NULL; 2448 } else 2449 router_ll6 = (struct in6_addr *)NULL; 2450 2451 /* ip6 */ 2452 ip6 = mtod(m, struct ip6_hdr *); 2453 ip6->ip6_flow = 0; 2454 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2455 ip6->ip6_vfc |= IPV6_VERSION; 2456 /* ip6->ip6_plen will be set later */ 2457 ip6->ip6_nxt = IPPROTO_ICMPV6; 2458 ip6->ip6_hlim = 255; 2459 /* ip6->ip6_src must be linklocal addr for my outgoing if. */ 2460 bcopy(&ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr)); 2461 bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr)); 2462 2463 /* ND Redirect */ 2464 nd_rd = (struct nd_redirect *)(ip6 + 1); 2465 nd_rd->nd_rd_type = ND_REDIRECT; 2466 nd_rd->nd_rd_code = 0; 2467 nd_rd->nd_rd_reserved = 0; 2468 if (nh->nh_flags & NHF_GATEWAY) { 2469 /* 2470 * nd_rd->nd_rd_target must be a link-local address in 2471 * better router cases. 2472 */ 2473 if (!router_ll6) 2474 goto fail; 2475 bcopy(router_ll6, &nd_rd->nd_rd_target, 2476 sizeof(nd_rd->nd_rd_target)); 2477 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2478 sizeof(nd_rd->nd_rd_dst)); 2479 } else { 2480 /* make sure redtgt == reddst */ 2481 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target, 2482 sizeof(nd_rd->nd_rd_target)); 2483 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2484 sizeof(nd_rd->nd_rd_dst)); 2485 } 2486 2487 p = (u_char *)(nd_rd + 1); 2488 2489 if (!router_ll6) 2490 goto nolladdropt; 2491 2492 { 2493 /* target lladdr option */ 2494 int len; 2495 struct nd_opt_hdr *nd_opt; 2496 char *lladdr; 2497 2498 ln = nd6_lookup(router_ll6, LLE_SF(AF_INET6, 0), ifp); 2499 if (ln == NULL) 2500 goto nolladdropt; 2501 2502 len = sizeof(*nd_opt) + ifp->if_addrlen; 2503 len = (len + 7) & ~7; /* round by 8 */ 2504 /* safety check */ 2505 if (len + (p - (u_char *)ip6) > maxlen) 2506 goto nolladdropt; 2507 2508 if (ln->la_flags & LLE_VALID) { 2509 nd_opt = (struct nd_opt_hdr *)p; 2510 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 2511 nd_opt->nd_opt_len = len >> 3; 2512 lladdr = (char *)(nd_opt + 1); 2513 bcopy(ln->ll_addr, lladdr, ifp->if_addrlen); 2514 p += len; 2515 } 2516 } 2517 nolladdropt: 2518 if (ln != NULL) 2519 LLE_RUNLOCK(ln); 2520 2521 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2522 2523 /* just to be safe */ 2524 #ifdef M_DECRYPTED /*not openbsd*/ 2525 if (m0->m_flags & M_DECRYPTED) 2526 goto noredhdropt; 2527 #endif 2528 if (p - (u_char *)ip6 > maxlen) 2529 goto noredhdropt; 2530 2531 { 2532 /* redirected header option */ 2533 int len; 2534 struct nd_opt_rd_hdr *nd_opt_rh; 2535 2536 /* 2537 * compute the maximum size for icmp6 redirect header option. 2538 * XXX room for auth header? 2539 */ 2540 len = maxlen - (p - (u_char *)ip6); 2541 len &= ~7; 2542 2543 /* This is just for simplicity. */ 2544 if (m0->m_pkthdr.len != m0->m_len) { 2545 if (m0->m_next) { 2546 m_freem(m0->m_next); 2547 m0->m_next = NULL; 2548 } 2549 m0->m_pkthdr.len = m0->m_len; 2550 } 2551 2552 /* 2553 * Redirected header option spec (RFC2461 4.6.3) talks nothing 2554 * about padding/truncate rule for the original IP packet. 2555 * From the discussion on IPv6imp in Feb 1999, 2556 * the consensus was: 2557 * - "attach as much as possible" is the goal 2558 * - pad if not aligned (original size can be guessed by 2559 * original ip6 header) 2560 * Following code adds the padding if it is simple enough, 2561 * and truncates if not. 2562 */ 2563 if (m0->m_next || m0->m_pkthdr.len != m0->m_len) 2564 panic("assumption failed in %s:%d", __FILE__, 2565 __LINE__); 2566 2567 if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) { 2568 /* not enough room, truncate */ 2569 m0->m_pkthdr.len = m0->m_len = len - 2570 sizeof(*nd_opt_rh); 2571 } else { 2572 /* enough room, pad or truncate */ 2573 size_t extra; 2574 2575 extra = m0->m_pkthdr.len % 8; 2576 if (extra) { 2577 /* pad if easy enough, truncate if not */ 2578 if (8 - extra <= M_TRAILINGSPACE(m0)) { 2579 /* pad */ 2580 bzero(m0->m_data + m0->m_len, 8 - extra); 2581 m0->m_len += (8 - extra); 2582 m0->m_pkthdr.len += (8 - extra); 2583 } else { 2584 /* truncate */ 2585 m0->m_pkthdr.len -= extra; 2586 m0->m_len -= extra; 2587 } 2588 } 2589 len = m0->m_pkthdr.len + sizeof(*nd_opt_rh); 2590 m0->m_pkthdr.len = m0->m_len = len - 2591 sizeof(*nd_opt_rh); 2592 } 2593 2594 nd_opt_rh = (struct nd_opt_rd_hdr *)p; 2595 bzero(nd_opt_rh, sizeof(*nd_opt_rh)); 2596 nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER; 2597 nd_opt_rh->nd_opt_rh_len = len >> 3; 2598 p += sizeof(*nd_opt_rh); 2599 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2600 2601 /* connect m0 to m */ 2602 m_tag_delete_chain(m0, NULL); 2603 m0->m_flags &= ~M_PKTHDR; 2604 m->m_next = m0; 2605 m->m_pkthdr.len = m->m_len + m0->m_len; 2606 m0 = NULL; 2607 } 2608 noredhdropt:; 2609 if (m0) { 2610 m_freem(m0); 2611 m0 = NULL; 2612 } 2613 2614 /* XXX: clear embedded link IDs in the inner header */ 2615 in6_clearscope(&sip6->ip6_src); 2616 in6_clearscope(&sip6->ip6_dst); 2617 in6_clearscope(&nd_rd->nd_rd_target); 2618 in6_clearscope(&nd_rd->nd_rd_dst); 2619 2620 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr)); 2621 2622 nd_rd->nd_rd_cksum = 0; 2623 nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2624 sizeof(*ip6), ntohs(ip6->ip6_plen)); 2625 2626 if (send_sendso_input_hook != NULL) { 2627 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, sizeof(unsigned short), 2628 M_NOWAIT); 2629 if (mtag == NULL) 2630 goto fail; 2631 *(unsigned short *)(mtag + 1) = nd_rd->nd_rd_type; 2632 m_tag_prepend(m, mtag); 2633 } 2634 2635 /* send the packet to outside... */ 2636 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2637 if (outif) { 2638 icmp6_ifstat_inc(outif, ifs6_out_msg); 2639 icmp6_ifstat_inc(outif, ifs6_out_redirect); 2640 } 2641 ICMP6STAT_INC2(icp6s_outhist, ND_REDIRECT); 2642 2643 return; 2644 2645 fail: 2646 if (m) 2647 m_freem(m); 2648 if (m0) 2649 m_freem(m0); 2650 } 2651 2652 /* 2653 * ICMPv6 socket option processing. 2654 */ 2655 int 2656 icmp6_ctloutput(struct socket *so, struct sockopt *sopt) 2657 { 2658 int error = 0; 2659 int optlen; 2660 struct inpcb *inp = sotoinpcb(so); 2661 int level, op, optname; 2662 2663 if (sopt) { 2664 level = sopt->sopt_level; 2665 op = sopt->sopt_dir; 2666 optname = sopt->sopt_name; 2667 optlen = sopt->sopt_valsize; 2668 } else 2669 level = op = optname = optlen = 0; 2670 2671 if (level != IPPROTO_ICMPV6) { 2672 return EINVAL; 2673 } 2674 2675 switch (op) { 2676 case SOPT_SET: 2677 switch (optname) { 2678 case ICMP6_FILTER: 2679 { 2680 struct icmp6_filter ic6f; 2681 2682 if (optlen != sizeof(ic6f)) { 2683 error = EMSGSIZE; 2684 break; 2685 } 2686 error = sooptcopyin(sopt, &ic6f, optlen, optlen); 2687 if (error == 0) { 2688 INP_WLOCK(inp); 2689 *inp->in6p_icmp6filt = ic6f; 2690 INP_WUNLOCK(inp); 2691 } 2692 break; 2693 } 2694 2695 default: 2696 error = ENOPROTOOPT; 2697 break; 2698 } 2699 break; 2700 2701 case SOPT_GET: 2702 switch (optname) { 2703 case ICMP6_FILTER: 2704 { 2705 struct icmp6_filter ic6f; 2706 2707 INP_RLOCK(inp); 2708 ic6f = *inp->in6p_icmp6filt; 2709 INP_RUNLOCK(inp); 2710 error = sooptcopyout(sopt, &ic6f, sizeof(ic6f)); 2711 break; 2712 } 2713 2714 default: 2715 error = ENOPROTOOPT; 2716 break; 2717 } 2718 break; 2719 } 2720 2721 return (error); 2722 } 2723 2724 static int sysctl_icmp6lim_and_jitter(SYSCTL_HANDLER_ARGS); 2725 VNET_DEFINE_STATIC(u_int, icmp6errppslim) = 100; 2726 #define V_icmp6errppslim VNET(icmp6errppslim) 2727 SYSCTL_PROC(_net_inet6_icmp6, ICMPV6CTL_ERRPPSLIMIT, errppslimit, 2728 CTLTYPE_UINT | CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(icmp6errppslim), 0, 2729 &sysctl_icmp6lim_and_jitter, "IU", 2730 "Maximum number of ICMPv6 error/reply messages per second"); 2731 2732 typedef enum { 2733 RATELIM_PARAM_PROB = 0, 2734 RATELIM_TOO_BIG, 2735 RATELIM_UNREACH, 2736 RATELIM_TEXCEED, 2737 RATELIM_REDIR, 2738 RATELIM_REPLY, 2739 RATELIM_OTHER, 2740 RATELIM_MAX 2741 } ratelim_which; 2742 2743 static const char *icmp6_rate_descrs[RATELIM_MAX] = { 2744 [RATELIM_PARAM_PROB] = "bad IPv6 header", 2745 [RATELIM_TOO_BIG] = "packet too big", 2746 [RATELIM_UNREACH] = "destination unreachable", 2747 [RATELIM_TEXCEED] = "time exceeded", 2748 [RATELIM_REPLY] = "echo reply", 2749 [RATELIM_REDIR] = "neighbor discovery redirect", 2750 [RATELIM_OTHER] = "(other)", 2751 }; 2752 2753 VNET_DEFINE_STATIC(int, icmp6lim_curr_jitter[RATELIM_MAX]) = {0}; 2754 #define V_icmp6lim_curr_jitter VNET(icmp6lim_curr_jitter) 2755 2756 VNET_DEFINE_STATIC(u_int, icmp6lim_jitter) = 8; 2757 #define V_icmp6lim_jitter VNET(icmp6lim_jitter) 2758 SYSCTL_PROC(_net_inet6_icmp6, OID_AUTO, icmp6lim_jitter, CTLTYPE_UINT | 2759 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(icmp6lim_jitter), 0, 2760 &sysctl_icmp6lim_and_jitter, "IU", 2761 "Random errppslimit jitter adjustment limit"); 2762 2763 VNET_DEFINE_STATIC(int, icmp6lim_output) = 1; 2764 #define V_icmp6lim_output VNET(icmp6lim_output) 2765 SYSCTL_INT(_net_inet6_icmp6, OID_AUTO, icmp6lim_output, 2766 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(icmp6lim_output), 0, 2767 "Enable logging of ICMPv6 response rate limiting"); 2768 2769 static void 2770 icmp6lim_new_jitter(int which) 2771 { 2772 /* 2773 * Adjust limit +/- to jitter the measurement to deny a side-channel 2774 * port scan as in https://dl.acm.org/doi/10.1145/3372297.3417280 2775 */ 2776 KASSERT(which >= 0 && which < RATELIM_MAX, 2777 ("%s: which %d", __func__, which)); 2778 if (V_icmp6lim_jitter > 0) 2779 V_icmp6lim_curr_jitter[which] = 2780 arc4random_uniform(V_icmp6lim_jitter * 2 + 1) - 2781 V_icmp6lim_jitter; 2782 } 2783 2784 static int 2785 sysctl_icmp6lim_and_jitter(SYSCTL_HANDLER_ARGS) 2786 { 2787 uint32_t new; 2788 int error; 2789 bool lim; 2790 2791 MPASS(oidp->oid_arg1 == &VNET_NAME(icmp6errppslim) || 2792 oidp->oid_arg1 == &VNET_NAME(icmp6lim_jitter)); 2793 2794 lim = (oidp->oid_arg1 == &VNET_NAME(icmp6errppslim)); 2795 new = lim ? V_icmp6errppslim : V_icmp6lim_jitter; 2796 error = sysctl_handle_int(oidp, &new, 0, req); 2797 if (error == 0 && req->newptr) { 2798 if (lim) { 2799 if (new != 0 && new <= V_icmp6lim_jitter) 2800 error = EINVAL; 2801 else 2802 V_icmp6errppslim = new; 2803 } else { 2804 if (new >= V_icmp6errppslim) 2805 error = EINVAL; 2806 else { 2807 V_icmp6lim_jitter = new; 2808 for (int i = 0; i < RATELIM_MAX; i++) { 2809 icmp6lim_new_jitter(i); 2810 } 2811 } 2812 } 2813 } 2814 MPASS(V_icmp6errppslim == 0 || V_icmp6errppslim > V_icmp6lim_jitter); 2815 2816 return (error); 2817 } 2818 2819 2820 VNET_DEFINE_STATIC(struct counter_rate *, icmp6_rates[RATELIM_MAX]); 2821 #define V_icmp6_rates VNET(icmp6_rates) 2822 2823 static void 2824 icmp6_ratelimit_init(void) 2825 { 2826 2827 for (int i = 0; i < RATELIM_MAX; i++) { 2828 V_icmp6_rates[i] = counter_rate_alloc(M_WAITOK, 1); 2829 icmp6lim_new_jitter(i); 2830 } 2831 } 2832 VNET_SYSINIT(icmp6_ratelimit, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY, 2833 icmp6_ratelimit_init, NULL); 2834 2835 #ifdef VIMAGE 2836 static void 2837 icmp6_ratelimit_uninit(void) 2838 { 2839 2840 for (int i = 0; i < RATELIM_MAX; i++) 2841 counter_rate_free(V_icmp6_rates[i]); 2842 } 2843 VNET_SYSUNINIT(icmp6_ratelimit, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD, 2844 icmp6_ratelimit_uninit, NULL); 2845 #endif 2846 2847 /* 2848 * Perform rate limit check. 2849 * Returns 0 if it is okay to send the icmp6 packet. 2850 * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate 2851 * limitation. 2852 * 2853 * XXX per-destination/type check necessary? 2854 * 2855 * dst - not used at this moment 2856 * code - not used at this moment 2857 */ 2858 int 2859 icmp6_ratelimit(const struct in6_addr *dst, const int type, const int code) 2860 { 2861 ratelim_which which; 2862 int64_t pps; 2863 2864 if (V_icmp6errppslim == 0) 2865 return (0); 2866 2867 switch (type) { 2868 case ICMP6_PARAM_PROB: 2869 which = RATELIM_PARAM_PROB; 2870 break; 2871 case ICMP6_PACKET_TOO_BIG: 2872 which = RATELIM_TOO_BIG; 2873 break; 2874 case ICMP6_DST_UNREACH: 2875 which = RATELIM_UNREACH; 2876 break; 2877 case ICMP6_TIME_EXCEEDED: 2878 which = RATELIM_TEXCEED; 2879 break; 2880 case ND_REDIRECT: 2881 which = RATELIM_REDIR; 2882 break; 2883 case ICMP6_ECHO_REPLY: 2884 which = RATELIM_REPLY; 2885 break; 2886 default: 2887 which = RATELIM_OTHER; 2888 break; 2889 }; 2890 2891 pps = counter_ratecheck(V_icmp6_rates[which], V_icmp6errppslim + 2892 V_icmp6lim_curr_jitter[which]); 2893 if (pps > 0) { 2894 if (V_icmp6lim_output) 2895 log(LOG_NOTICE, "Limiting ICMPv6 %s output from %jd " 2896 "to %d packets/sec\n", icmp6_rate_descrs[which], 2897 (intmax_t )pps, V_icmp6errppslim + 2898 V_icmp6lim_curr_jitter[which]); 2899 icmp6lim_new_jitter(which); 2900 } 2901 if (pps == -1) { 2902 ICMP6STAT_INC(icp6s_toofreq); 2903 return (-1); 2904 } 2905 2906 return (0); 2907 } 2908