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 #include <sys/cdefs.h> 64 #define MBUF_PRIVATE /* XXXRW: Optimisation tries to avoid M_EXT mbufs */ 65 66 #include "opt_inet.h" 67 #include "opt_inet6.h" 68 69 #include <sys/param.h> 70 #include <sys/domain.h> 71 #include <sys/jail.h> 72 #include <sys/kernel.h> 73 #include <sys/lock.h> 74 #include <sys/malloc.h> 75 #include <sys/mbuf.h> 76 #include <sys/proc.h> 77 #include <sys/protosw.h> 78 #include <sys/signalvar.h> 79 #include <sys/socket.h> 80 #include <sys/socketvar.h> 81 #include <sys/sx.h> 82 #include <sys/syslog.h> 83 #include <sys/systm.h> 84 #include <sys/time.h> 85 86 #include <net/if.h> 87 #include <net/if_var.h> 88 #include <net/if_dl.h> 89 #include <net/if_llatbl.h> 90 #include <net/if_private.h> 91 #include <net/if_types.h> 92 #include <net/route.h> 93 #include <net/route/route_ctl.h> 94 #include <net/route/nhop.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_fib.h> 105 #include <netinet6/in6_ifattach.h> 106 #include <netinet6/in6_pcb.h> 107 #include <netinet6/ip6_var.h> 108 #include <netinet6/scope6_var.h> 109 #include <netinet6/mld6_var.h> 110 #include <netinet6/nd6.h> 111 #include <netinet6/send.h> 112 113 extern ip6proto_ctlinput_t *ip6_ctlprotox[]; 114 115 VNET_PCPUSTAT_DEFINE(struct icmp6stat, icmp6stat); 116 VNET_PCPUSTAT_SYSINIT(icmp6stat); 117 SYSCTL_VNET_PCPUSTAT(_net_inet6_icmp6, ICMPV6CTL_STATS, stats, 118 struct icmp6stat, icmp6stat, 119 "ICMPv6 statistics (struct icmp6stat, netinet/icmp6.h)"); 120 121 #ifdef VIMAGE 122 VNET_PCPUSTAT_SYSUNINIT(icmp6stat); 123 #endif /* VIMAGE */ 124 125 VNET_DEFINE_STATIC(int, icmp6_rediraccept) = 1; 126 #define V_icmp6_rediraccept VNET(icmp6_rediraccept) 127 SYSCTL_INT(_net_inet6_icmp6, ICMPV6CTL_REDIRACCEPT, rediraccept, 128 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(icmp6_rediraccept), 0, 129 "Accept ICMPv6 redirect messages"); 130 131 VNET_DEFINE_STATIC(int, icmp6_redirtimeout) = 10 * 60; /* 10 minutes */ 132 #define V_icmp6_redirtimeout VNET(icmp6_redirtimeout) 133 SYSCTL_INT(_net_inet6_icmp6, ICMPV6CTL_REDIRTIMEOUT, redirtimeout, 134 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(icmp6_redirtimeout), 0, 135 "Delay in seconds before expiring redirect route"); 136 137 VNET_DEFINE_STATIC(int, icmp6_nodeinfo) = 0; 138 #define V_icmp6_nodeinfo VNET(icmp6_nodeinfo) 139 SYSCTL_INT(_net_inet6_icmp6, ICMPV6CTL_NODEINFO, nodeinfo, 140 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(icmp6_nodeinfo), 0, 141 "Mask of enabled RFC4620 node information query types"); 142 143 VNET_DECLARE(struct inpcbinfo, ripcbinfo); 144 #define V_ripcbinfo VNET(ripcbinfo) 145 146 VNET_DECLARE(int, rip_bind_all_fibs); 147 #define V_rip_bind_all_fibs VNET(rip_bind_all_fibs) 148 149 static void icmp6_errcount(int, int); 150 static int icmp6_rip6_input(struct mbuf **, int); 151 static void icmp6_reflect(struct mbuf *, size_t); 152 static const char *icmp6_redirect_diag(struct in6_addr *, 153 struct in6_addr *, struct in6_addr *); 154 static struct mbuf *ni6_input(struct mbuf *, int, struct prison *); 155 static struct mbuf *ni6_nametodns(const char *, int, int); 156 static int ni6_dnsmatch(const char *, int, const char *, int); 157 static int ni6_addrs(struct icmp6_nodeinfo *, struct mbuf *, 158 struct ifnet **, struct in6_addr *); 159 static int ni6_store_addrs(struct icmp6_nodeinfo *, struct icmp6_nodeinfo *, 160 struct ifnet *, int); 161 static int icmp6_notify_error(struct mbuf **, int, int); 162 static void icmp6_mtudisc_update(struct ip6ctlparam *ip6cp); 163 164 /* 165 * Kernel module interface for updating icmp6stat. The argument is an index 166 * into icmp6stat treated as an array of u_quad_t. While this encodes the 167 * general layout of icmp6stat into the caller, it doesn't encode its 168 * location, so that future changes to add, for example, per-CPU stats 169 * support won't cause binary compatibility problems for kernel modules. 170 */ 171 void 172 kmod_icmp6stat_inc(int statnum) 173 { 174 175 counter_u64_add(VNET(icmp6stat)[statnum], 1); 176 } 177 178 static void 179 icmp6_errcount(int type, int code) 180 { 181 switch (type) { 182 case ICMP6_DST_UNREACH: 183 switch (code) { 184 case ICMP6_DST_UNREACH_NOROUTE: 185 ICMP6STAT_INC(icp6s_odst_unreach_noroute); 186 return; 187 case ICMP6_DST_UNREACH_ADMIN: 188 ICMP6STAT_INC(icp6s_odst_unreach_admin); 189 return; 190 case ICMP6_DST_UNREACH_BEYONDSCOPE: 191 ICMP6STAT_INC(icp6s_odst_unreach_beyondscope); 192 return; 193 case ICMP6_DST_UNREACH_ADDR: 194 ICMP6STAT_INC(icp6s_odst_unreach_addr); 195 return; 196 case ICMP6_DST_UNREACH_NOPORT: 197 ICMP6STAT_INC(icp6s_odst_unreach_noport); 198 return; 199 } 200 break; 201 case ICMP6_PACKET_TOO_BIG: 202 ICMP6STAT_INC(icp6s_opacket_too_big); 203 return; 204 case ICMP6_TIME_EXCEEDED: 205 switch (code) { 206 case ICMP6_TIME_EXCEED_TRANSIT: 207 ICMP6STAT_INC(icp6s_otime_exceed_transit); 208 return; 209 case ICMP6_TIME_EXCEED_REASSEMBLY: 210 ICMP6STAT_INC(icp6s_otime_exceed_reassembly); 211 return; 212 } 213 break; 214 case ICMP6_PARAM_PROB: 215 switch (code) { 216 case ICMP6_PARAMPROB_HEADER: 217 ICMP6STAT_INC(icp6s_oparamprob_header); 218 return; 219 case ICMP6_PARAMPROB_NEXTHEADER: 220 ICMP6STAT_INC(icp6s_oparamprob_nextheader); 221 return; 222 case ICMP6_PARAMPROB_OPTION: 223 ICMP6STAT_INC(icp6s_oparamprob_option); 224 return; 225 } 226 break; 227 case ND_REDIRECT: 228 ICMP6STAT_INC(icp6s_oredirect); 229 return; 230 } 231 ICMP6STAT_INC(icp6s_ounknown); 232 } 233 234 /* 235 * A wrapper function for icmp6_error() necessary when the erroneous packet 236 * may not contain enough scope zone information. 237 */ 238 void 239 icmp6_error2(struct mbuf *m, int type, int code, int param, 240 struct ifnet *ifp) 241 { 242 struct ip6_hdr *ip6; 243 244 if (ifp == NULL) 245 return; 246 247 if (m->m_len < sizeof(struct ip6_hdr)) { 248 m = m_pullup(m, sizeof(struct ip6_hdr)); 249 if (m == NULL) { 250 IP6STAT_INC(ip6s_exthdrtoolong); 251 return; 252 } 253 } 254 ip6 = mtod(m, struct ip6_hdr *); 255 256 if (in6_setscope(&ip6->ip6_src, ifp, NULL) != 0) 257 return; 258 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0) 259 return; 260 261 icmp6_error(m, type, code, param); 262 } 263 264 /* 265 * Generate an error packet of type error in response to bad IP6 packet. 266 */ 267 void 268 icmp6_error(struct mbuf *m, int type, int code, int param) 269 { 270 struct ip6_hdr *oip6, *nip6; 271 struct icmp6_hdr *icmp6; 272 struct epoch_tracker et; 273 u_int preplen; 274 int off; 275 int nxt; 276 277 ICMP6STAT_INC(icp6s_error); 278 279 /* count per-type-code statistics */ 280 icmp6_errcount(type, code); 281 282 #ifdef M_DECRYPTED /*not openbsd*/ 283 if (m->m_flags & M_DECRYPTED) { 284 ICMP6STAT_INC(icp6s_canterror); 285 goto freeit; 286 } 287 #endif 288 289 if (m->m_len < sizeof(struct ip6_hdr)) { 290 m = m_pullup(m, sizeof(struct ip6_hdr)); 291 if (m == NULL) { 292 IP6STAT_INC(ip6s_exthdrtoolong); 293 return; 294 } 295 } 296 oip6 = mtod(m, struct ip6_hdr *); 297 298 /* 299 * If the destination address of the erroneous packet is a multicast 300 * address, or the packet was sent using link-layer multicast, 301 * we should basically suppress sending an error (RFC 2463, Section 302 * 2.4). 303 * We have two exceptions (the item e.2 in that section): 304 * - the Packet Too Big message can be sent for path MTU discovery. 305 * - the Parameter Problem Message that can be allowed an icmp6 error 306 * in the option type field. This check has been done in 307 * ip6_unknown_opt(), so we can just check the type and code. 308 */ 309 if ((m->m_flags & (M_BCAST|M_MCAST) || 310 IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) && 311 (type != ICMP6_PACKET_TOO_BIG && 312 (type != ICMP6_PARAM_PROB || 313 code != ICMP6_PARAMPROB_OPTION))) 314 goto freeit; 315 316 /* 317 * RFC 2463, 2.4 (e.5): source address check. 318 * XXX: the case of anycast source? 319 */ 320 if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) || 321 IN6_IS_ADDR_MULTICAST(&oip6->ip6_src)) 322 goto freeit; 323 324 /* 325 * If we are about to send ICMPv6 against ICMPv6 error/redirect, 326 * don't do it. 327 */ 328 nxt = -1; 329 off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt); 330 if (off >= 0 && nxt == IPPROTO_ICMPV6) { 331 struct icmp6_hdr *icp; 332 333 if (m->m_len < off + sizeof(struct icmp6_hdr)) { 334 m = m_pullup(m, off + sizeof(struct icmp6_hdr)); 335 if (m == NULL) { 336 IP6STAT_INC(ip6s_exthdrtoolong); 337 return; 338 } 339 } 340 oip6 = mtod(m, struct ip6_hdr *); 341 icp = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 342 343 if (icp->icmp6_type < ICMP6_ECHO_REQUEST || 344 icp->icmp6_type == ND_REDIRECT) { 345 /* 346 * ICMPv6 error 347 * Special case: for redirect (which is 348 * informational) we must not send icmp6 error. 349 */ 350 ICMP6STAT_INC(icp6s_canterror); 351 goto freeit; 352 } else { 353 /* ICMPv6 informational - send the error */ 354 } 355 } else { 356 /* non-ICMPv6 - send the error */ 357 } 358 359 /* Finally, do rate limitation check. */ 360 if (icmp6_ratelimit(&oip6->ip6_src, type, code)) 361 goto freeit; 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 == NULL) { 373 nd6log((LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__)); 374 return; 375 } 376 377 nip6 = mtod(m, struct ip6_hdr *); 378 nip6->ip6_src = oip6->ip6_src; 379 nip6->ip6_dst = oip6->ip6_dst; 380 381 in6_clearscope(&oip6->ip6_src); 382 in6_clearscope(&oip6->ip6_dst); 383 384 icmp6 = (struct icmp6_hdr *)(nip6 + 1); 385 icmp6->icmp6_type = type; 386 icmp6->icmp6_code = code; 387 icmp6->icmp6_pptr = htonl((u_int32_t)param); 388 389 ICMP6STAT_INC2(icp6s_outhist, type); 390 NET_EPOCH_ENTER(et); 391 icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */ 392 NET_EPOCH_EXIT(et); 393 394 return; 395 396 freeit: 397 /* 398 * If we can't tell whether or not we can generate ICMP6, free it. 399 */ 400 m_freem(m); 401 } 402 403 int 404 icmp6_errmap(const struct icmp6_hdr *icmp6) 405 { 406 407 switch (icmp6->icmp6_type) { 408 case ICMP6_DST_UNREACH: 409 switch (icmp6->icmp6_code) { 410 case ICMP6_DST_UNREACH_NOROUTE: 411 case ICMP6_DST_UNREACH_ADDR: 412 return (EHOSTUNREACH); 413 case ICMP6_DST_UNREACH_NOPORT: 414 case ICMP6_DST_UNREACH_ADMIN: 415 return (ECONNREFUSED); 416 case ICMP6_DST_UNREACH_BEYONDSCOPE: 417 return (ENOPROTOOPT); 418 default: 419 return (0); /* Shouldn't happen. */ 420 } 421 case ICMP6_PACKET_TOO_BIG: 422 return (EMSGSIZE); 423 case ICMP6_TIME_EXCEEDED: 424 switch (icmp6->icmp6_code) { 425 case ICMP6_TIME_EXCEED_TRANSIT: 426 return (EHOSTUNREACH); 427 case ICMP6_TIME_EXCEED_REASSEMBLY: 428 return (0); 429 default: 430 return (0); /* Shouldn't happen. */ 431 } 432 case ICMP6_PARAM_PROB: 433 switch (icmp6->icmp6_code) { 434 case ICMP6_PARAMPROB_NEXTHEADER: 435 return (ECONNREFUSED); 436 case ICMP6_PARAMPROB_HEADER: 437 case ICMP6_PARAMPROB_OPTION: 438 return (ENOPROTOOPT); 439 default: 440 return (0); /* Shouldn't happen. */ 441 } 442 default: 443 return (0); 444 } 445 } 446 447 /* 448 * Process a received ICMP6 message. 449 */ 450 int 451 icmp6_input(struct mbuf **mp, int *offp, int proto) 452 { 453 struct mbuf *m, *n; 454 struct ifnet *ifp; 455 struct ip6_hdr *ip6, *nip6; 456 struct icmp6_hdr *icmp6, *nicmp6; 457 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 458 int code, error, icmp6len, ip6len, noff, off, sum; 459 460 NET_EPOCH_ASSERT(); 461 462 m = *mp; 463 off = *offp; 464 465 if (m->m_len < off + sizeof(struct icmp6_hdr)) { 466 m = m_pullup(m, off + sizeof(struct icmp6_hdr)); 467 if (m == NULL) { 468 IP6STAT_INC(ip6s_exthdrtoolong); 469 *mp = m; 470 return (IPPROTO_DONE); 471 } 472 } 473 474 /* 475 * Locate icmp6 structure in mbuf, and check 476 * that not corrupted and of at least minimum length 477 */ 478 479 icmp6len = m->m_pkthdr.len - off; 480 if (icmp6len < sizeof(struct icmp6_hdr)) { 481 ICMP6STAT_INC(icp6s_tooshort); 482 goto freeit; 483 } 484 485 ip6 = mtod(m, struct ip6_hdr *); 486 ifp = m->m_pkthdr.rcvif; 487 /* 488 * Check multicast group membership. 489 * Note: SSM filters are not applied for ICMPv6 traffic. 490 */ 491 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 492 struct in6_multi *inm; 493 494 inm = in6m_lookup(ifp, &ip6->ip6_dst); 495 if (inm == NULL) { 496 IP6STAT_INC(ip6s_notmember); 497 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 498 goto freeit; 499 } 500 } 501 502 /* Calculate the checksum. */ 503 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off); 504 code = icmp6->icmp6_code; 505 if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) { 506 nd6log((LOG_ERR, 507 "ICMP6 checksum error(%d|%x) %s\n", 508 icmp6->icmp6_type, sum, 509 ip6_sprintf(ip6bufs, &ip6->ip6_src))); 510 ICMP6STAT_INC(icp6s_checksum); 511 goto freeit; 512 } 513 514 ICMP6STAT_INC2(icp6s_inhist, icmp6->icmp6_type); 515 icmp6_ifstat_inc(ifp, ifs6_in_msg); 516 if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK) 517 icmp6_ifstat_inc(ifp, ifs6_in_error); 518 519 ip6len = sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen); 520 switch (icmp6->icmp6_type) { 521 case ICMP6_DST_UNREACH: 522 icmp6_ifstat_inc(ifp, ifs6_in_dstunreach); 523 switch (code) { 524 case ICMP6_DST_UNREACH_ADMIN: 525 icmp6_ifstat_inc(ifp, ifs6_in_adminprohib); 526 case ICMP6_DST_UNREACH_NOROUTE: 527 case ICMP6_DST_UNREACH_ADDR: 528 case ICMP6_DST_UNREACH_BEYONDSCOPE: 529 case ICMP6_DST_UNREACH_NOPORT: 530 goto deliver; 531 default: 532 goto badcode; 533 } 534 case ICMP6_PACKET_TOO_BIG: 535 icmp6_ifstat_inc(ifp, ifs6_in_pkttoobig); 536 /* 537 * Validation is made in icmp6_mtudisc_update. 538 * Updating the path MTU will be done after examining 539 * intermediate extension headers. 540 */ 541 goto deliver; 542 case ICMP6_TIME_EXCEEDED: 543 icmp6_ifstat_inc(ifp, ifs6_in_timeexceed); 544 switch (code) { 545 case ICMP6_TIME_EXCEED_TRANSIT: 546 case ICMP6_TIME_EXCEED_REASSEMBLY: 547 goto deliver; 548 default: 549 goto badcode; 550 } 551 case ICMP6_PARAM_PROB: 552 icmp6_ifstat_inc(ifp, ifs6_in_paramprob); 553 switch (code) { 554 case ICMP6_PARAMPROB_NEXTHEADER: 555 case ICMP6_PARAMPROB_HEADER: 556 case ICMP6_PARAMPROB_OPTION: 557 goto deliver; 558 default: 559 goto badcode; 560 } 561 case ICMP6_ECHO_REQUEST: 562 icmp6_ifstat_inc(ifp, ifs6_in_echo); 563 if (code != 0) 564 goto badcode; 565 if (icmp6_ratelimit(&ip6->ip6_src, ICMP6_ECHO_REPLY, 0)) 566 break; 567 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) { 568 /* Give up remote */ 569 break; 570 } 571 if (!M_WRITABLE(n) 572 || n->m_len < off + sizeof(struct icmp6_hdr)) { 573 struct mbuf *n0 = n; 574 int n0len; 575 576 CTASSERT(sizeof(*nip6) + sizeof(*nicmp6) <= MHLEN); 577 n = m_gethdr(M_NOWAIT, n0->m_type); 578 if (n == NULL) { 579 /* Give up remote */ 580 m_freem(n0); 581 break; 582 } 583 584 m_move_pkthdr(n, n0); /* FIB copied. */ 585 n0len = n0->m_pkthdr.len; /* save for use below */ 586 /* 587 * Copy IPv6 and ICMPv6 only. 588 */ 589 nip6 = mtod(n, struct ip6_hdr *); 590 bcopy(ip6, nip6, sizeof(struct ip6_hdr)); 591 nicmp6 = (struct icmp6_hdr *)(nip6 + 1); 592 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr)); 593 noff = sizeof(struct ip6_hdr); 594 /* new mbuf contains only ipv6+icmpv6 headers */ 595 n->m_len = noff + sizeof(struct icmp6_hdr); 596 /* 597 * Adjust mbuf. ip6_plen will be adjusted in 598 * ip6_output(). 599 */ 600 m_adj(n0, off + sizeof(struct icmp6_hdr)); 601 /* recalculate complete packet size */ 602 n->m_pkthdr.len = n0len + (noff - off); 603 n->m_next = n0; 604 } else { 605 if (n->m_len < off + sizeof(*nicmp6)) { 606 n = m_pullup(n, off + sizeof(*nicmp6)); 607 if (n == NULL) { 608 IP6STAT_INC(ip6s_exthdrtoolong); 609 break; 610 } 611 } 612 nicmp6 = (struct icmp6_hdr *)(mtod(n, caddr_t) + off); 613 noff = off; 614 } 615 if (n) { 616 nicmp6->icmp6_type = ICMP6_ECHO_REPLY; 617 nicmp6->icmp6_code = 0; 618 ICMP6STAT_INC(icp6s_reflect); 619 ICMP6STAT_INC2(icp6s_outhist, ICMP6_ECHO_REPLY); 620 icmp6_reflect(n, noff); 621 } 622 break; 623 624 case ICMP6_ECHO_REPLY: 625 icmp6_ifstat_inc(ifp, ifs6_in_echoreply); 626 if (code != 0) 627 goto badcode; 628 break; 629 630 case MLD_LISTENER_QUERY: 631 case MLD_LISTENER_REPORT: 632 case MLD_LISTENER_DONE: 633 case MLDV2_LISTENER_REPORT: 634 /* 635 * Drop MLD traffic which is not link-local, has a hop limit 636 * of greater than 1 hop, or which does not have the 637 * IPv6 HBH Router Alert option. 638 * As IPv6 HBH options are stripped in ip6_input() we must 639 * check an mbuf header flag. 640 * XXX Should we also sanity check that these messages 641 * were directed to a link-local multicast prefix? 642 */ 643 if ((ip6->ip6_hlim != 1) || (m->m_flags & M_RTALERT_MLD) == 0) 644 goto freeit; 645 if (mld_input(&m, off, icmp6len) != 0) { 646 *mp = NULL; 647 return (IPPROTO_DONE); 648 } 649 /* m stays. */ 650 break; 651 652 case ICMP6_WRUREQUEST: /* ICMP6_FQDN_QUERY */ 653 { 654 enum { WRU, FQDN } mode; 655 struct prison *pr; 656 657 if (!V_icmp6_nodeinfo) 658 break; 659 660 if (icmp6len == sizeof(struct icmp6_hdr) + 4) 661 mode = WRU; 662 else if (icmp6len >= sizeof(struct icmp6_nodeinfo)) 663 mode = FQDN; 664 else 665 goto badlen; 666 667 pr = NULL; 668 sx_slock(&allprison_lock); 669 TAILQ_FOREACH(pr, &allprison, pr_list) 670 if (pr->pr_vnet == ifp->if_vnet) 671 break; 672 sx_sunlock(&allprison_lock); 673 if (pr == NULL) 674 pr = curthread->td_ucred->cr_prison; 675 if (mode == FQDN) { 676 if (m->m_len < off + sizeof(struct icmp6_nodeinfo)) { 677 m = m_pullup(m, off + 678 sizeof(struct icmp6_nodeinfo)); 679 if (m == NULL) { 680 IP6STAT_INC(ip6s_exthdrtoolong); 681 *mp = m; 682 return (IPPROTO_DONE); 683 } 684 } 685 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 686 if (n) 687 n = ni6_input(n, off, pr); 688 /* XXX meaningless if n == NULL */ 689 noff = sizeof(struct ip6_hdr); 690 } else { 691 u_char *p; 692 int maxhlen, hlen; 693 694 /* 695 * XXX: this combination of flags is pointless, 696 * but should we keep this for compatibility? 697 */ 698 if ((V_icmp6_nodeinfo & (ICMP6_NODEINFO_FQDNOK | 699 ICMP6_NODEINFO_TMPADDROK)) != 700 (ICMP6_NODEINFO_FQDNOK | ICMP6_NODEINFO_TMPADDROK)) 701 break; 702 703 if (code != 0) 704 goto badcode; 705 706 CTASSERT(sizeof(*nip6) + sizeof(*nicmp6) + 4 <= MHLEN); 707 n = m_gethdr(M_NOWAIT, m->m_type); 708 if (n == NULL) { 709 /* Give up remote */ 710 break; 711 } 712 if (!m_dup_pkthdr(n, m, M_NOWAIT)) { 713 /* 714 * Previous code did a blind M_COPY_PKTHDR 715 * and said "just for rcvif". If true, then 716 * we could tolerate the dup failing (due to 717 * the deep copy of the tag chain). For now 718 * be conservative and just fail. 719 */ 720 m_free(n); 721 n = NULL; 722 break; 723 } 724 /* 725 * Copy IPv6 and ICMPv6 only. 726 */ 727 nip6 = mtod(n, struct ip6_hdr *); 728 bcopy(ip6, nip6, sizeof(struct ip6_hdr)); 729 nicmp6 = (struct icmp6_hdr *)(nip6 + 1); 730 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr)); 731 p = (u_char *)(nicmp6 + 1); 732 bzero(p, 4); 733 734 maxhlen = M_TRAILINGSPACE(n) - 735 (sizeof(*nip6) + sizeof(*nicmp6) + 4); 736 mtx_lock(&pr->pr_mtx); 737 hlen = strlen(pr->pr_hostname); 738 if (maxhlen > hlen) 739 maxhlen = hlen; 740 /* meaningless TTL */ 741 bcopy(pr->pr_hostname, p + 4, maxhlen); 742 mtx_unlock(&pr->pr_mtx); 743 noff = sizeof(struct ip6_hdr); 744 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + 745 sizeof(struct icmp6_hdr) + 4 + maxhlen; 746 nicmp6->icmp6_type = ICMP6_WRUREPLY; 747 nicmp6->icmp6_code = 0; 748 } 749 if (n) { 750 ICMP6STAT_INC(icp6s_reflect); 751 ICMP6STAT_INC2(icp6s_outhist, ICMP6_WRUREPLY); 752 icmp6_reflect(n, noff); 753 } 754 break; 755 } 756 757 case ICMP6_WRUREPLY: 758 if (code != 0) 759 goto badcode; 760 break; 761 762 case ND_ROUTER_SOLICIT: 763 icmp6_ifstat_inc(ifp, ifs6_in_routersolicit); 764 if (code != 0) 765 goto badcode; 766 if (icmp6len < sizeof(struct nd_router_solicit)) 767 goto badlen; 768 if (send_sendso_input_hook != NULL) { 769 if (m->m_len < off + icmp6len) { 770 m = m_pullup(m, off + icmp6len); 771 if (m == NULL) { 772 IP6STAT_INC(ip6s_exthdrtoolong); 773 *mp = NULL; 774 return (IPPROTO_DONE); 775 } 776 } 777 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 778 if (error == 0) { 779 m = NULL; 780 goto freeit; 781 } 782 } 783 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 784 nd6_rs_input(m, off, icmp6len); 785 m = n; 786 if (m == NULL) 787 goto freeit; 788 break; 789 790 case ND_ROUTER_ADVERT: 791 icmp6_ifstat_inc(ifp, ifs6_in_routeradvert); 792 if (code != 0) 793 goto badcode; 794 if (icmp6len < sizeof(struct nd_router_advert)) 795 goto badlen; 796 if (send_sendso_input_hook != NULL) { 797 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 798 if (error == 0) { 799 m = NULL; 800 goto freeit; 801 } 802 } 803 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 804 nd6_ra_input(m, off, icmp6len); 805 m = n; 806 if (m == NULL) 807 goto freeit; 808 break; 809 810 case ND_NEIGHBOR_SOLICIT: 811 icmp6_ifstat_inc(ifp, ifs6_in_neighborsolicit); 812 if (code != 0) 813 goto badcode; 814 if (icmp6len < sizeof(struct nd_neighbor_solicit)) 815 goto badlen; 816 if (send_sendso_input_hook != NULL) { 817 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 818 if (error == 0) { 819 m = NULL; 820 goto freeit; 821 } 822 } 823 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 824 nd6_ns_input(m, off, icmp6len); 825 m = n; 826 if (m == NULL) 827 goto freeit; 828 break; 829 830 case ND_NEIGHBOR_ADVERT: 831 icmp6_ifstat_inc(ifp, ifs6_in_neighboradvert); 832 if (code != 0) 833 goto badcode; 834 if (icmp6len < sizeof(struct nd_neighbor_advert)) 835 goto badlen; 836 if (send_sendso_input_hook != NULL) { 837 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 838 if (error == 0) { 839 m = NULL; 840 goto freeit; 841 } 842 } 843 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 844 nd6_na_input(m, off, icmp6len); 845 m = n; 846 if (m == NULL) 847 goto freeit; 848 break; 849 850 case ND_REDIRECT: 851 icmp6_ifstat_inc(ifp, ifs6_in_redirect); 852 if (code != 0) 853 goto badcode; 854 if (icmp6len < sizeof(struct nd_redirect)) 855 goto badlen; 856 if (send_sendso_input_hook != NULL) { 857 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); 858 if (error == 0) { 859 m = NULL; 860 goto freeit; 861 } 862 } 863 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 864 icmp6_redirect_input(m, off); 865 m = n; 866 if (m == NULL) 867 goto freeit; 868 break; 869 870 case ICMP6_ROUTER_RENUMBERING: 871 if (code != ICMP6_ROUTER_RENUMBERING_COMMAND && 872 code != ICMP6_ROUTER_RENUMBERING_RESULT) 873 goto badcode; 874 if (icmp6len < sizeof(struct icmp6_router_renum)) 875 goto badlen; 876 break; 877 878 default: 879 nd6log((LOG_DEBUG, 880 "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n", 881 icmp6->icmp6_type, ip6_sprintf(ip6bufs, &ip6->ip6_src), 882 ip6_sprintf(ip6bufd, &ip6->ip6_dst), 883 ifp ? ifp->if_index : 0)); 884 if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) { 885 /* ICMPv6 error: MUST deliver it by spec... */ 886 goto deliver; 887 } else { 888 /* ICMPv6 informational: MUST not deliver */ 889 break; 890 } 891 deliver: 892 if (icmp6_notify_error(&m, off, icmp6len) != 0) { 893 /* In this case, m should've been freed. */ 894 *mp = NULL; 895 return (IPPROTO_DONE); 896 } 897 break; 898 899 badcode: 900 ICMP6STAT_INC(icp6s_badcode); 901 break; 902 903 badlen: 904 ICMP6STAT_INC(icp6s_badlen); 905 break; 906 } 907 908 /* deliver the packet to appropriate sockets */ 909 icmp6_rip6_input(&m, *offp); 910 911 *mp = m; 912 return (IPPROTO_DONE); 913 914 freeit: 915 m_freem(m); 916 *mp = NULL; 917 return (IPPROTO_DONE); 918 } 919 920 static int 921 icmp6_notify_error(struct mbuf **mp, int off, int icmp6len) 922 { 923 struct mbuf *m; 924 struct icmp6_hdr *icmp6; 925 struct ip6_hdr *eip6; 926 u_int32_t notifymtu; 927 struct sockaddr_in6 icmp6src, icmp6dst; 928 929 m = *mp; 930 931 if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) { 932 ICMP6STAT_INC(icp6s_tooshort); 933 goto freeit; 934 } 935 936 if (m->m_len < off + sizeof(*icmp6) + sizeof(struct ip6_hdr)) { 937 m = m_pullup(m, off + sizeof(*icmp6) + sizeof(struct ip6_hdr)); 938 if (m == NULL) { 939 IP6STAT_INC(ip6s_exthdrtoolong); 940 *mp = m; 941 return (-1); 942 } 943 } 944 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 945 eip6 = (struct ip6_hdr *)(icmp6 + 1); 946 bzero(&icmp6dst, sizeof(icmp6dst)); 947 948 /* Detect the upper level protocol */ 949 { 950 u_int8_t nxt = eip6->ip6_nxt; 951 int eoff = off + sizeof(struct icmp6_hdr) + 952 sizeof(struct ip6_hdr); 953 struct ip6ctlparam ip6cp; 954 int icmp6type = icmp6->icmp6_type; 955 struct ip6_frag *fh; 956 struct ip6_rthdr *rth; 957 struct ip6_rthdr0 *rth0; 958 int rthlen; 959 960 while (1) { /* XXX: should avoid infinite loop explicitly? */ 961 struct ip6_ext *eh; 962 963 switch (nxt) { 964 case IPPROTO_HOPOPTS: 965 case IPPROTO_DSTOPTS: 966 case IPPROTO_AH: 967 if (m->m_len < eoff + sizeof(struct ip6_ext)) { 968 m = m_pullup(m, eoff + 969 sizeof(struct ip6_ext)); 970 if (m == NULL) { 971 IP6STAT_INC(ip6s_exthdrtoolong); 972 *mp = m; 973 return (-1); 974 } 975 } 976 eh = (struct ip6_ext *) 977 (mtod(m, caddr_t) + eoff); 978 if (nxt == IPPROTO_AH) 979 eoff += (eh->ip6e_len + 2) << 2; 980 else 981 eoff += (eh->ip6e_len + 1) << 3; 982 nxt = eh->ip6e_nxt; 983 break; 984 case IPPROTO_ROUTING: 985 /* 986 * When the erroneous packet contains a 987 * routing header, we should examine the 988 * header to determine the final destination. 989 * Otherwise, we can't properly update 990 * information that depends on the final 991 * destination (e.g. path MTU). 992 */ 993 if (m->m_len < eoff + sizeof(*rth)) { 994 m = m_pullup(m, eoff + sizeof(*rth)); 995 if (m == NULL) { 996 IP6STAT_INC(ip6s_exthdrtoolong); 997 *mp = m; 998 return (-1); 999 } 1000 } 1001 rth = (struct ip6_rthdr *) 1002 (mtod(m, caddr_t) + eoff); 1003 rthlen = (rth->ip6r_len + 1) << 3; 1004 /* 1005 * XXX: currently there is no 1006 * officially defined type other 1007 * than type-0. 1008 * Note that if the segment left field 1009 * is 0, all intermediate hops must 1010 * have been passed. 1011 */ 1012 if (rth->ip6r_segleft && 1013 rth->ip6r_type == IPV6_RTHDR_TYPE_0) { 1014 int hops; 1015 1016 if (m->m_len < eoff + rthlen) { 1017 m = m_pullup(m, eoff + rthlen); 1018 if (m == NULL) { 1019 IP6STAT_INC( 1020 ip6s_exthdrtoolong); 1021 *mp = m; 1022 return (-1); 1023 } 1024 } 1025 rth0 = (struct ip6_rthdr0 *) 1026 (mtod(m, caddr_t) + eoff); 1027 1028 /* just ignore a bogus header */ 1029 if ((rth0->ip6r0_len % 2) == 0 && 1030 (hops = rth0->ip6r0_len/2)) 1031 icmp6dst.sin6_addr = *((struct in6_addr *)(rth0 + 1) + (hops - 1)); 1032 } 1033 eoff += rthlen; 1034 nxt = rth->ip6r_nxt; 1035 break; 1036 case IPPROTO_FRAGMENT: 1037 if (m->m_len < eoff + sizeof(struct ip6_frag)) { 1038 m = m_pullup(m, eoff + 1039 sizeof(struct ip6_frag)); 1040 if (m == NULL) { 1041 IP6STAT_INC(ip6s_exthdrtoolong); 1042 *mp = m; 1043 return (-1); 1044 } 1045 } 1046 fh = (struct ip6_frag *)(mtod(m, caddr_t) + 1047 eoff); 1048 /* 1049 * Data after a fragment header is meaningless 1050 * unless it is the first fragment, but 1051 * we'll go to the notify label for path MTU 1052 * discovery. 1053 */ 1054 if (fh->ip6f_offlg & IP6F_OFF_MASK) 1055 goto notify; 1056 1057 eoff += sizeof(struct ip6_frag); 1058 nxt = fh->ip6f_nxt; 1059 break; 1060 default: 1061 /* 1062 * This case includes ESP and the No Next 1063 * Header. In such cases going to the notify 1064 * label does not have any meaning 1065 * (i.e. ctlfunc will be NULL), but we go 1066 * anyway since we might have to update 1067 * path MTU information. 1068 */ 1069 goto notify; 1070 } 1071 } 1072 notify: 1073 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 1074 1075 /* 1076 * retrieve parameters from the inner IPv6 header, and convert 1077 * them into sockaddr structures. 1078 * XXX: there is no guarantee that the source or destination 1079 * addresses of the inner packet are in the same scope as 1080 * the addresses of the icmp packet. But there is no other 1081 * way to determine the zone. 1082 */ 1083 eip6 = (struct ip6_hdr *)(icmp6 + 1); 1084 1085 /* 1086 * Protocol layers can't do anything useful with unspecified 1087 * addresses. 1088 */ 1089 if (IN6_IS_ADDR_UNSPECIFIED(&eip6->ip6_src) || 1090 IN6_IS_ADDR_UNSPECIFIED(&eip6->ip6_dst)) 1091 goto freeit; 1092 1093 icmp6dst.sin6_len = sizeof(struct sockaddr_in6); 1094 icmp6dst.sin6_family = AF_INET6; 1095 if (IN6_IS_ADDR_UNSPECIFIED(&icmp6dst.sin6_addr)) 1096 icmp6dst.sin6_addr = eip6->ip6_dst; 1097 if (in6_setscope(&icmp6dst.sin6_addr, m->m_pkthdr.rcvif, NULL)) 1098 goto freeit; 1099 bzero(&icmp6src, sizeof(icmp6src)); 1100 icmp6src.sin6_len = sizeof(struct sockaddr_in6); 1101 icmp6src.sin6_family = AF_INET6; 1102 icmp6src.sin6_addr = eip6->ip6_src; 1103 if (in6_setscope(&icmp6src.sin6_addr, m->m_pkthdr.rcvif, NULL)) 1104 goto freeit; 1105 icmp6src.sin6_flowinfo = 1106 (eip6->ip6_flow & IPV6_FLOWLABEL_MASK); 1107 1108 ip6cp.ip6c_m = m; 1109 ip6cp.ip6c_icmp6 = icmp6; 1110 ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1); 1111 ip6cp.ip6c_off = eoff; 1112 ip6cp.ip6c_finaldst = &icmp6dst; 1113 ip6cp.ip6c_src = &icmp6src; 1114 ip6cp.ip6c_nxt = nxt; 1115 1116 if (icmp6type == ICMP6_PACKET_TOO_BIG) { 1117 notifymtu = ntohl(icmp6->icmp6_mtu); 1118 ip6cp.ip6c_cmdarg = (void *)¬ifymtu; 1119 icmp6_mtudisc_update(&ip6cp); 1120 } 1121 1122 if (ip6_ctlprotox[nxt] != NULL) 1123 ip6_ctlprotox[nxt](&ip6cp); 1124 } 1125 *mp = m; 1126 return (0); 1127 1128 freeit: 1129 m_freem(m); 1130 *mp = NULL; 1131 return (-1); 1132 } 1133 1134 static void 1135 icmp6_mtudisc_update(struct ip6ctlparam *ip6cp) 1136 { 1137 struct in6_addr *dst = &ip6cp->ip6c_finaldst->sin6_addr; 1138 struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6; 1139 struct mbuf *m = ip6cp->ip6c_m; 1140 u_int mtu = ntohl(icmp6->icmp6_mtu); 1141 struct in_conninfo inc; 1142 uint32_t max_mtu; 1143 1144 if (mtu < IPV6_MMTU) 1145 return; 1146 1147 bzero(&inc, sizeof(inc)); 1148 inc.inc_fibnum = M_GETFIB(m); 1149 inc.inc_flags |= INC_ISIPV6; 1150 inc.inc6_faddr = *dst; 1151 if (in6_setscope(&inc.inc6_faddr, m->m_pkthdr.rcvif, NULL)) 1152 return; 1153 1154 max_mtu = tcp_hc_getmtu(&inc); 1155 if (max_mtu == 0) 1156 max_mtu = tcp_maxmtu6(&inc, NULL); 1157 1158 if (mtu < max_mtu) { 1159 tcp_hc_updatemtu(&inc, mtu); 1160 ICMP6STAT_INC(icp6s_pmtuchg); 1161 } 1162 } 1163 1164 /* 1165 * Process a Node Information Query packet, based on 1166 * draft-ietf-ipngwg-icmp-name-lookups-07. 1167 * 1168 * Spec incompatibilities: 1169 * - IPv6 Subject address handling 1170 * - IPv4 Subject address handling support missing 1171 * - Proxy reply (answer even if it's not for me) 1172 * - joins NI group address at in6_ifattach() time only, does not cope 1173 * with hostname changes by sethostname(3) 1174 */ 1175 static struct mbuf * 1176 ni6_input(struct mbuf *m, int off, struct prison *pr) 1177 { 1178 struct icmp6_nodeinfo *ni6, *nni6; 1179 struct mbuf *n = NULL; 1180 u_int16_t qtype; 1181 int subjlen; 1182 int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); 1183 struct ni_reply_fqdn *fqdn; 1184 int addrs; /* for NI_QTYPE_NODEADDR */ 1185 struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */ 1186 struct in6_addr in6_subj; /* subject address */ 1187 struct ip6_hdr *ip6; 1188 int oldfqdn = 0; /* if 1, return pascal string (03 draft) */ 1189 char *subj = NULL; 1190 struct in6_ifaddr *ia6 = NULL; 1191 1192 ip6 = mtod(m, struct ip6_hdr *); 1193 ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off); 1194 1195 /* 1196 * Validate IPv6 source address. 1197 * The default configuration MUST be to refuse answering queries from 1198 * global-scope addresses according to RFC4602. 1199 * Notes: 1200 * - it's not very clear what "refuse" means; this implementation 1201 * simply drops it. 1202 * - it's not very easy to identify global-scope (unicast) addresses 1203 * since there are many prefixes for them. It should be safer 1204 * and in practice sufficient to check "all" but loopback and 1205 * link-local (note that site-local unicast was deprecated and 1206 * ULA is defined as global scope-wise) 1207 */ 1208 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_GLOBALOK) == 0 && 1209 !IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) && 1210 !IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) 1211 goto bad; 1212 1213 /* 1214 * Validate IPv6 destination address. 1215 * 1216 * The Responder must discard the Query without further processing 1217 * unless it is one of the Responder's unicast or anycast addresses, or 1218 * a link-local scope multicast address which the Responder has joined. 1219 * [RFC4602, Section 5.] 1220 */ 1221 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 1222 if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst)) 1223 goto bad; 1224 /* else it's a link-local multicast, fine */ 1225 } else { /* unicast or anycast */ 1226 ia6 = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */, false); 1227 if (ia6 == NULL) 1228 goto bad; /* XXX impossible */ 1229 1230 if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) && 1231 !(V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK)) { 1232 nd6log((LOG_DEBUG, "ni6_input: ignore node info to " 1233 "a temporary address in %s:%d", 1234 __FILE__, __LINE__)); 1235 goto bad; 1236 } 1237 } 1238 1239 /* validate query Subject field. */ 1240 qtype = ntohs(ni6->ni_qtype); 1241 subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo); 1242 switch (qtype) { 1243 case NI_QTYPE_NOOP: 1244 case NI_QTYPE_SUPTYPES: 1245 /* 07 draft */ 1246 if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0) 1247 break; 1248 /* FALLTHROUGH */ 1249 case NI_QTYPE_FQDN: 1250 case NI_QTYPE_NODEADDR: 1251 case NI_QTYPE_IPV4ADDR: 1252 switch (ni6->ni_code) { 1253 case ICMP6_NI_SUBJ_IPV6: 1254 #if ICMP6_NI_SUBJ_IPV6 != 0 1255 case 0: 1256 #endif 1257 /* 1258 * backward compatibility - try to accept 03 draft 1259 * format, where no Subject is present. 1260 */ 1261 if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 && 1262 subjlen == 0) { 1263 oldfqdn++; 1264 break; 1265 } 1266 #if ICMP6_NI_SUBJ_IPV6 != 0 1267 if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6) 1268 goto bad; 1269 #endif 1270 1271 if (subjlen != sizeof(struct in6_addr)) 1272 goto bad; 1273 1274 /* 1275 * Validate Subject address. 1276 * 1277 * Not sure what exactly "address belongs to the node" 1278 * means in the spec, is it just unicast, or what? 1279 * 1280 * At this moment we consider Subject address as 1281 * "belong to the node" if the Subject address equals 1282 * to the IPv6 destination address; validation for 1283 * IPv6 destination address should have done enough 1284 * check for us. 1285 * 1286 * We do not do proxy at this moment. 1287 */ 1288 m_copydata(m, off + sizeof(struct icmp6_nodeinfo), 1289 subjlen, (caddr_t)&in6_subj); 1290 if (in6_setscope(&in6_subj, m->m_pkthdr.rcvif, NULL)) 1291 goto bad; 1292 1293 subj = (char *)&in6_subj; 1294 if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &in6_subj)) 1295 break; 1296 1297 /* 1298 * XXX if we are to allow other cases, we should really 1299 * be careful about scope here. 1300 * basically, we should disallow queries toward IPv6 1301 * destination X with subject Y, 1302 * if scope(X) > scope(Y). 1303 * if we allow scope(X) > scope(Y), it will result in 1304 * information leakage across scope boundary. 1305 */ 1306 goto bad; 1307 1308 case ICMP6_NI_SUBJ_FQDN: 1309 /* 1310 * Validate Subject name with gethostname(3). 1311 * 1312 * The behavior may need some debate, since: 1313 * - we are not sure if the node has FQDN as 1314 * hostname (returned by gethostname(3)). 1315 * - the code does wildcard match for truncated names. 1316 * however, we are not sure if we want to perform 1317 * wildcard match, if gethostname(3) side has 1318 * truncated hostname. 1319 */ 1320 mtx_lock(&pr->pr_mtx); 1321 n = ni6_nametodns(pr->pr_hostname, 1322 strlen(pr->pr_hostname), 0); 1323 mtx_unlock(&pr->pr_mtx); 1324 if (!n || n->m_next || n->m_len == 0) 1325 goto bad; 1326 if (m->m_len < off + sizeof(struct icmp6_nodeinfo) + 1327 subjlen) { 1328 m = m_pullup(m, off + 1329 sizeof(struct icmp6_nodeinfo) + subjlen); 1330 if (m == NULL) { 1331 IP6STAT_INC(ip6s_exthdrtoolong); 1332 goto bad; 1333 } 1334 } 1335 /* ip6 possibly invalid but not used after. */ 1336 ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off); 1337 subj = (char *)(mtod(m, caddr_t) + off + 1338 sizeof(struct icmp6_nodeinfo)); 1339 if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *), 1340 n->m_len)) { 1341 goto bad; 1342 } 1343 m_freem(n); 1344 n = NULL; 1345 break; 1346 1347 case ICMP6_NI_SUBJ_IPV4: /* XXX: to be implemented? */ 1348 default: 1349 goto bad; 1350 } 1351 break; 1352 } 1353 1354 /* refuse based on configuration. XXX ICMP6_NI_REFUSED? */ 1355 switch (qtype) { 1356 case NI_QTYPE_FQDN: 1357 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_FQDNOK) == 0) 1358 goto bad; 1359 break; 1360 case NI_QTYPE_NODEADDR: 1361 case NI_QTYPE_IPV4ADDR: 1362 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_NODEADDROK) == 0) 1363 goto bad; 1364 break; 1365 } 1366 1367 /* guess reply length */ 1368 switch (qtype) { 1369 case NI_QTYPE_NOOP: 1370 break; /* no reply data */ 1371 case NI_QTYPE_SUPTYPES: 1372 replylen += sizeof(u_int32_t); 1373 break; 1374 case NI_QTYPE_FQDN: 1375 /* XXX will append an mbuf */ 1376 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); 1377 break; 1378 case NI_QTYPE_NODEADDR: 1379 addrs = ni6_addrs(ni6, m, &ifp, (struct in6_addr *)subj); 1380 if ((replylen += addrs * (sizeof(struct in6_addr) + 1381 sizeof(u_int32_t))) > MCLBYTES) 1382 replylen = MCLBYTES; /* XXX: will truncate pkt later */ 1383 break; 1384 case NI_QTYPE_IPV4ADDR: 1385 /* unsupported - should respond with unknown Qtype? */ 1386 break; 1387 default: 1388 /* 1389 * XXX: We must return a reply with the ICMP6 code 1390 * `unknown Qtype' in this case. However we regard the case 1391 * as an FQDN query for backward compatibility. 1392 * Older versions set a random value to this field, 1393 * so it rarely varies in the defined qtypes. 1394 * But the mechanism is not reliable... 1395 * maybe we should obsolete older versions. 1396 */ 1397 qtype = NI_QTYPE_FQDN; 1398 /* XXX will append an mbuf */ 1399 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); 1400 oldfqdn++; 1401 break; 1402 } 1403 1404 /* Allocate an mbuf to reply. */ 1405 if (replylen > MCLBYTES) { 1406 /* 1407 * XXX: should we try to allocate more? But MCLBYTES 1408 * is probably much larger than IPV6_MMTU... 1409 */ 1410 goto bad; 1411 } 1412 if (replylen > MHLEN) 1413 n = m_getcl(M_NOWAIT, m->m_type, M_PKTHDR); 1414 else 1415 n = m_gethdr(M_NOWAIT, m->m_type); 1416 if (n == NULL) { 1417 m_freem(m); 1418 return (NULL); 1419 } 1420 m_move_pkthdr(n, m); /* just for recvif and FIB */ 1421 n->m_pkthdr.len = n->m_len = replylen; 1422 1423 /* copy mbuf header and IPv6 + Node Information base headers */ 1424 bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr)); 1425 nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1); 1426 bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo)); 1427 1428 /* qtype dependent procedure */ 1429 switch (qtype) { 1430 case NI_QTYPE_NOOP: 1431 nni6->ni_code = ICMP6_NI_SUCCESS; 1432 nni6->ni_flags = 0; 1433 break; 1434 case NI_QTYPE_SUPTYPES: 1435 { 1436 u_int32_t v; 1437 nni6->ni_code = ICMP6_NI_SUCCESS; 1438 nni6->ni_flags = htons(0x0000); /* raw bitmap */ 1439 /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */ 1440 v = (u_int32_t)htonl(0x0000000f); 1441 bcopy(&v, nni6 + 1, sizeof(u_int32_t)); 1442 break; 1443 } 1444 case NI_QTYPE_FQDN: 1445 nni6->ni_code = ICMP6_NI_SUCCESS; 1446 fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) + 1447 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo)); 1448 nni6->ni_flags = 0; /* XXX: meaningless TTL */ 1449 fqdn->ni_fqdn_ttl = 0; /* ditto. */ 1450 /* 1451 * XXX do we really have FQDN in hostname? 1452 */ 1453 mtx_lock(&pr->pr_mtx); 1454 n->m_next = ni6_nametodns(pr->pr_hostname, 1455 strlen(pr->pr_hostname), oldfqdn); 1456 mtx_unlock(&pr->pr_mtx); 1457 if (n->m_next == NULL) 1458 goto bad; 1459 /* XXX we assume that n->m_next is not a chain */ 1460 if (n->m_next->m_next != NULL) 1461 goto bad; 1462 n->m_pkthdr.len += n->m_next->m_len; 1463 break; 1464 case NI_QTYPE_NODEADDR: 1465 { 1466 int lenlim, copied; 1467 1468 nni6->ni_code = ICMP6_NI_SUCCESS; 1469 n->m_pkthdr.len = n->m_len = 1470 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); 1471 lenlim = M_TRAILINGSPACE(n); 1472 copied = ni6_store_addrs(ni6, nni6, ifp, lenlim); 1473 /* XXX: reset mbuf length */ 1474 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + 1475 sizeof(struct icmp6_nodeinfo) + copied; 1476 break; 1477 } 1478 default: 1479 break; /* XXX impossible! */ 1480 } 1481 1482 nni6->ni_type = ICMP6_NI_REPLY; 1483 m_freem(m); 1484 return (n); 1485 1486 bad: 1487 m_freem(m); 1488 if (n) 1489 m_freem(n); 1490 return (NULL); 1491 } 1492 1493 /* 1494 * make a mbuf with DNS-encoded string. no compression support. 1495 * 1496 * XXX names with less than 2 dots (like "foo" or "foo.section") will be 1497 * treated as truncated name (two \0 at the end). this is a wild guess. 1498 * 1499 * old - return pascal string if non-zero 1500 */ 1501 static struct mbuf * 1502 ni6_nametodns(const char *name, int namelen, int old) 1503 { 1504 struct mbuf *m; 1505 char *cp, *ep; 1506 const char *p, *q; 1507 int i, len, nterm; 1508 1509 if (old) 1510 len = namelen + 1; 1511 else 1512 len = MCLBYTES; 1513 1514 /* Because MAXHOSTNAMELEN is usually 256, we use cluster mbuf. */ 1515 if (len > MLEN) 1516 m = m_getcl(M_NOWAIT, MT_DATA, 0); 1517 else 1518 m = m_get(M_NOWAIT, MT_DATA); 1519 if (m == NULL) 1520 goto fail; 1521 1522 if (old) { 1523 m->m_len = len; 1524 *mtod(m, char *) = namelen; 1525 bcopy(name, mtod(m, char *) + 1, namelen); 1526 return m; 1527 } else { 1528 m->m_len = 0; 1529 cp = mtod(m, char *); 1530 ep = mtod(m, char *) + M_TRAILINGSPACE(m); 1531 1532 /* if not certain about my name, return empty buffer */ 1533 if (namelen == 0) 1534 return m; 1535 1536 /* 1537 * guess if it looks like shortened hostname, or FQDN. 1538 * shortened hostname needs two trailing "\0". 1539 */ 1540 i = 0; 1541 for (p = name; p < name + namelen; p++) { 1542 if (*p && *p == '.') 1543 i++; 1544 } 1545 if (i < 2) 1546 nterm = 2; 1547 else 1548 nterm = 1; 1549 1550 p = name; 1551 while (cp < ep && p < name + namelen) { 1552 i = 0; 1553 for (q = p; q < name + namelen && *q && *q != '.'; q++) 1554 i++; 1555 /* result does not fit into mbuf */ 1556 if (cp + i + 1 >= ep) 1557 goto fail; 1558 /* 1559 * DNS label length restriction, RFC1035 page 8. 1560 * "i == 0" case is included here to avoid returning 1561 * 0-length label on "foo..bar". 1562 */ 1563 if (i <= 0 || i >= 64) 1564 goto fail; 1565 *cp++ = i; 1566 bcopy(p, cp, i); 1567 cp += i; 1568 p = q; 1569 if (p < name + namelen && *p == '.') 1570 p++; 1571 } 1572 /* termination */ 1573 if (cp + nterm >= ep) 1574 goto fail; 1575 while (nterm-- > 0) 1576 *cp++ = '\0'; 1577 m->m_len = cp - mtod(m, char *); 1578 return m; 1579 } 1580 1581 panic("should not reach here"); 1582 /* NOTREACHED */ 1583 1584 fail: 1585 if (m) 1586 m_freem(m); 1587 return NULL; 1588 } 1589 1590 /* 1591 * check if two DNS-encoded string matches. takes care of truncated 1592 * form (with \0\0 at the end). no compression support. 1593 * XXX upper/lowercase match (see RFC2065) 1594 */ 1595 static int 1596 ni6_dnsmatch(const char *a, int alen, const char *b, int blen) 1597 { 1598 const char *a0, *b0; 1599 int l; 1600 1601 /* simplest case - need validation? */ 1602 if (alen == blen && bcmp(a, b, alen) == 0) 1603 return 1; 1604 1605 a0 = a; 1606 b0 = b; 1607 1608 /* termination is mandatory */ 1609 if (alen < 2 || blen < 2) 1610 return 0; 1611 if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0') 1612 return 0; 1613 alen--; 1614 blen--; 1615 1616 while (a - a0 < alen && b - b0 < blen) { 1617 if (a - a0 + 1 > alen || b - b0 + 1 > blen) 1618 return 0; 1619 1620 if ((signed char)a[0] < 0 || (signed char)b[0] < 0) 1621 return 0; 1622 /* we don't support compression yet */ 1623 if (a[0] >= 64 || b[0] >= 64) 1624 return 0; 1625 1626 /* truncated case */ 1627 if (a[0] == 0 && a - a0 == alen - 1) 1628 return 1; 1629 if (b[0] == 0 && b - b0 == blen - 1) 1630 return 1; 1631 if (a[0] == 0 || b[0] == 0) 1632 return 0; 1633 1634 if (a[0] != b[0]) 1635 return 0; 1636 l = a[0]; 1637 if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen) 1638 return 0; 1639 if (bcmp(a + 1, b + 1, l) != 0) 1640 return 0; 1641 1642 a += 1 + l; 1643 b += 1 + l; 1644 } 1645 1646 if (a - a0 == alen && b - b0 == blen) 1647 return 1; 1648 else 1649 return 0; 1650 } 1651 1652 /* 1653 * calculate the number of addresses to be returned in the node info reply. 1654 */ 1655 static int 1656 ni6_addrs(struct icmp6_nodeinfo *ni6, struct mbuf *m, struct ifnet **ifpp, 1657 struct in6_addr *subj) 1658 { 1659 struct ifnet *ifp; 1660 struct in6_ifaddr *ifa6; 1661 struct ifaddr *ifa; 1662 int addrs = 0, addrsofif, iffound = 0; 1663 int niflags = ni6->ni_flags; 1664 1665 NET_EPOCH_ASSERT(); 1666 1667 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) { 1668 switch (ni6->ni_code) { 1669 case ICMP6_NI_SUBJ_IPV6: 1670 if (subj == NULL) /* must be impossible... */ 1671 return (0); 1672 break; 1673 default: 1674 /* 1675 * XXX: we only support IPv6 subject address for 1676 * this Qtype. 1677 */ 1678 return (0); 1679 } 1680 } 1681 1682 CK_STAILQ_FOREACH(ifp, &V_ifnet, if_link) { 1683 addrsofif = 0; 1684 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 1685 if (ifa->ifa_addr->sa_family != AF_INET6) 1686 continue; 1687 ifa6 = (struct in6_ifaddr *)ifa; 1688 1689 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 && 1690 IN6_ARE_ADDR_EQUAL(subj, &ifa6->ia_addr.sin6_addr)) 1691 iffound = 1; 1692 1693 /* 1694 * IPv4-mapped addresses can only be returned by a 1695 * Node Information proxy, since they represent 1696 * addresses of IPv4-only nodes, which perforce do 1697 * not implement this protocol. 1698 * [icmp-name-lookups-07, Section 5.4] 1699 * So we don't support NI_NODEADDR_FLAG_COMPAT in 1700 * this function at this moment. 1701 */ 1702 1703 /* What do we have to do about ::1? */ 1704 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { 1705 case IPV6_ADDR_SCOPE_LINKLOCAL: 1706 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) 1707 continue; 1708 break; 1709 case IPV6_ADDR_SCOPE_SITELOCAL: 1710 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) 1711 continue; 1712 break; 1713 case IPV6_ADDR_SCOPE_GLOBAL: 1714 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) 1715 continue; 1716 break; 1717 default: 1718 continue; 1719 } 1720 1721 /* 1722 * check if anycast is okay. 1723 * XXX: just experimental. not in the spec. 1724 */ 1725 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && 1726 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) 1727 continue; /* we need only unicast addresses */ 1728 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && 1729 (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) { 1730 continue; 1731 } 1732 addrsofif++; /* count the address */ 1733 } 1734 if (iffound) { 1735 *ifpp = ifp; 1736 return (addrsofif); 1737 } 1738 1739 addrs += addrsofif; 1740 } 1741 1742 return (addrs); 1743 } 1744 1745 static int 1746 ni6_store_addrs(struct icmp6_nodeinfo *ni6, struct icmp6_nodeinfo *nni6, 1747 struct ifnet *ifp0, int resid) 1748 { 1749 struct ifnet *ifp; 1750 struct in6_ifaddr *ifa6; 1751 struct ifaddr *ifa; 1752 struct ifnet *ifp_dep = NULL; 1753 int copied = 0, allow_deprecated = 0; 1754 u_char *cp = (u_char *)(nni6 + 1); 1755 int niflags = ni6->ni_flags; 1756 u_int32_t ltime; 1757 1758 NET_EPOCH_ASSERT(); 1759 1760 if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL)) 1761 return (0); /* needless to copy */ 1762 1763 ifp = ifp0 ? ifp0 : CK_STAILQ_FIRST(&V_ifnet); 1764 again: 1765 1766 for (; ifp; ifp = CK_STAILQ_NEXT(ifp, if_link)) { 1767 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 1768 if (ifa->ifa_addr->sa_family != AF_INET6) 1769 continue; 1770 ifa6 = (struct in6_ifaddr *)ifa; 1771 1772 if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 && 1773 allow_deprecated == 0) { 1774 /* 1775 * prefererred address should be put before 1776 * deprecated addresses. 1777 */ 1778 1779 /* record the interface for later search */ 1780 if (ifp_dep == NULL) 1781 ifp_dep = ifp; 1782 1783 continue; 1784 } else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 && 1785 allow_deprecated != 0) 1786 continue; /* we now collect deprecated addrs */ 1787 1788 /* What do we have to do about ::1? */ 1789 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { 1790 case IPV6_ADDR_SCOPE_LINKLOCAL: 1791 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) 1792 continue; 1793 break; 1794 case IPV6_ADDR_SCOPE_SITELOCAL: 1795 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) 1796 continue; 1797 break; 1798 case IPV6_ADDR_SCOPE_GLOBAL: 1799 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) 1800 continue; 1801 break; 1802 default: 1803 continue; 1804 } 1805 1806 /* 1807 * check if anycast is okay. 1808 * XXX: just experimental. not in the spec. 1809 */ 1810 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && 1811 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) 1812 continue; 1813 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && 1814 (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) { 1815 continue; 1816 } 1817 1818 /* now we can copy the address */ 1819 if (resid < sizeof(struct in6_addr) + 1820 sizeof(u_int32_t)) { 1821 /* 1822 * We give up much more copy. 1823 * Set the truncate flag and return. 1824 */ 1825 nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE; 1826 return (copied); 1827 } 1828 1829 /* 1830 * Set the TTL of the address. 1831 * The TTL value should be one of the following 1832 * according to the specification: 1833 * 1834 * 1. The remaining lifetime of a DHCP lease on the 1835 * address, or 1836 * 2. The remaining Valid Lifetime of a prefix from 1837 * which the address was derived through Stateless 1838 * Autoconfiguration. 1839 * 1840 * Note that we currently do not support stateful 1841 * address configuration by DHCPv6, so the former 1842 * case can't happen. 1843 */ 1844 if (ifa6->ia6_lifetime.ia6t_expire == 0) 1845 ltime = ND6_INFINITE_LIFETIME; 1846 else { 1847 if (ifa6->ia6_lifetime.ia6t_expire > 1848 time_uptime) 1849 ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_uptime); 1850 else 1851 ltime = 0; 1852 } 1853 1854 bcopy(<ime, cp, sizeof(u_int32_t)); 1855 cp += sizeof(u_int32_t); 1856 1857 /* copy the address itself */ 1858 bcopy(&ifa6->ia_addr.sin6_addr, cp, 1859 sizeof(struct in6_addr)); 1860 in6_clearscope((struct in6_addr *)cp); /* XXX */ 1861 cp += sizeof(struct in6_addr); 1862 1863 resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t)); 1864 copied += (sizeof(struct in6_addr) + sizeof(u_int32_t)); 1865 } 1866 if (ifp0) /* we need search only on the specified IF */ 1867 break; 1868 } 1869 1870 if (allow_deprecated == 0 && ifp_dep != NULL) { 1871 ifp = ifp_dep; 1872 allow_deprecated = 1; 1873 1874 goto again; 1875 } 1876 1877 return (copied); 1878 } 1879 1880 static bool 1881 icmp6_rip6_match(const struct inpcb *inp, void *v) 1882 { 1883 struct ip6_hdr *ip6 = v; 1884 1885 if ((inp->inp_vflag & INP_IPV6) == 0) 1886 return (false); 1887 if (inp->inp_ip_p != IPPROTO_ICMPV6) 1888 return (false); 1889 if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr) && 1890 !IN6_ARE_ADDR_EQUAL(&inp->in6p_laddr, &ip6->ip6_dst)) 1891 return (false); 1892 if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr) && 1893 !IN6_ARE_ADDR_EQUAL(&inp->in6p_faddr, &ip6->ip6_src)) 1894 return (false); 1895 return (true); 1896 } 1897 1898 /* 1899 * XXX almost dup'ed code with rip6_input. 1900 */ 1901 static int 1902 icmp6_rip6_input(struct mbuf **mp, int off) 1903 { 1904 struct mbuf *n, *m = *mp; 1905 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1906 struct inpcb_iterator inpi = INP_ITERATOR(&V_ripcbinfo, 1907 INPLOOKUP_RLOCKPCB, icmp6_rip6_match, ip6); 1908 struct inpcb *inp; 1909 struct sockaddr_in6 fromsa; 1910 struct icmp6_hdr *icmp6; 1911 struct mbuf *opts = NULL; 1912 int delivered = 0, fib; 1913 1914 /* This is assumed to be safe; icmp6_input() does a pullup. */ 1915 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off); 1916 1917 /* 1918 * XXX: the address may have embedded scope zone ID, which should be 1919 * hidden from applications. 1920 */ 1921 bzero(&fromsa, sizeof(fromsa)); 1922 fromsa.sin6_family = AF_INET6; 1923 fromsa.sin6_len = sizeof(struct sockaddr_in6); 1924 fromsa.sin6_addr = ip6->ip6_src; 1925 if (sa6_recoverscope(&fromsa)) { 1926 m_freem(m); 1927 *mp = NULL; 1928 return (IPPROTO_DONE); 1929 } 1930 1931 fib = M_GETFIB(m); 1932 1933 while ((inp = inp_next(&inpi)) != NULL) { 1934 if (V_rip_bind_all_fibs == 0 && fib != inp->inp_inc.inc_fibnum) 1935 /* 1936 * Sockets bound to a specific FIB can only receive 1937 * packets from that FIB. 1938 */ 1939 continue; 1940 if (ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type, 1941 inp->in6p_icmp6filt)) 1942 continue; 1943 /* 1944 * Recent network drivers tend to allocate a single 1945 * mbuf cluster, rather than to make a couple of 1946 * mbufs without clusters. Also, since the IPv6 code 1947 * path tries to avoid m_pullup(), it is highly 1948 * probable that we still have an mbuf cluster here 1949 * even though the necessary length can be stored in an 1950 * mbuf's internal buffer. 1951 * Meanwhile, the default size of the receive socket 1952 * buffer for raw sockets is not so large. This means 1953 * the possibility of packet loss is relatively higher 1954 * than before. To avoid this scenario, we copy the 1955 * received data to a separate mbuf that does not use 1956 * a cluster, if possible. 1957 * XXX: it is better to copy the data after stripping 1958 * intermediate headers. 1959 */ 1960 if ((m->m_flags & M_EXT) && m->m_next == NULL && 1961 m->m_len <= MHLEN) { 1962 n = m_get(M_NOWAIT, m->m_type); 1963 if (n != NULL) { 1964 if (m_dup_pkthdr(n, m, M_NOWAIT)) { 1965 bcopy(m->m_data, n->m_data, m->m_len); 1966 n->m_len = m->m_len; 1967 } else { 1968 m_free(n); 1969 n = NULL; 1970 } 1971 } 1972 } else 1973 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 1974 if (n == NULL) 1975 continue; 1976 if (inp->inp_flags & INP_CONTROLOPTS) 1977 ip6_savecontrol(inp, n, &opts); 1978 /* strip intermediate headers */ 1979 m_adj(n, off); 1980 SOCKBUF_LOCK(&inp->inp_socket->so_rcv); 1981 if (sbappendaddr_locked(&inp->inp_socket->so_rcv, 1982 (struct sockaddr *)&fromsa, n, opts) == 0) { 1983 soroverflow_locked(inp->inp_socket); 1984 m_freem(n); 1985 if (opts) 1986 m_freem(opts); 1987 } else { 1988 sorwakeup_locked(inp->inp_socket); 1989 delivered++; 1990 } 1991 opts = NULL; 1992 } 1993 m_freem(m); 1994 *mp = NULL; 1995 if (delivered == 0) 1996 IP6STAT_DEC(ip6s_delivered); 1997 return (IPPROTO_DONE); 1998 } 1999 2000 /* 2001 * Reflect the ip6 packet back to the source. 2002 * OFF points to the icmp6 header, counted from the top of the mbuf. 2003 */ 2004 static void 2005 icmp6_reflect(struct mbuf *m, size_t off) 2006 { 2007 struct in6_addr src6, *srcp; 2008 struct ip6_hdr *ip6; 2009 struct icmp6_hdr *icmp6; 2010 struct in6_ifaddr *ia = NULL; 2011 struct ifnet *outif = NULL; 2012 int plen; 2013 int type, code, hlim; 2014 2015 /* too short to reflect */ 2016 if (off < sizeof(struct ip6_hdr)) { 2017 nd6log((LOG_DEBUG, 2018 "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n", 2019 (u_long)off, (u_long)sizeof(struct ip6_hdr), 2020 __FILE__, __LINE__)); 2021 goto bad; 2022 } 2023 2024 /* 2025 * If there are extra headers between IPv6 and ICMPv6, strip 2026 * off that header first. 2027 */ 2028 #ifdef DIAGNOSTIC 2029 if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN) 2030 panic("assumption failed in icmp6_reflect"); 2031 #endif 2032 if (off > sizeof(struct ip6_hdr)) { 2033 size_t l; 2034 struct ip6_hdr nip6; 2035 2036 l = off - sizeof(struct ip6_hdr); 2037 m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6); 2038 m_adj(m, l); 2039 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 2040 if (m->m_len < l) { 2041 if ((m = m_pullup(m, l)) == NULL) 2042 return; 2043 } 2044 bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6)); 2045 } else /* off == sizeof(struct ip6_hdr) */ { 2046 size_t l; 2047 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 2048 if (m->m_len < l) { 2049 if ((m = m_pullup(m, l)) == NULL) 2050 return; 2051 } 2052 } 2053 plen = m->m_pkthdr.len - sizeof(struct ip6_hdr); 2054 ip6 = mtod(m, struct ip6_hdr *); 2055 ip6->ip6_nxt = IPPROTO_ICMPV6; 2056 icmp6 = (struct icmp6_hdr *)(ip6 + 1); 2057 type = icmp6->icmp6_type; /* keep type for statistics */ 2058 code = icmp6->icmp6_code; /* ditto. */ 2059 hlim = 0; 2060 srcp = NULL; 2061 2062 if (__predict_false(IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src))) { 2063 nd6log((LOG_DEBUG, 2064 "icmp6_reflect: source address is unspecified\n")); 2065 goto bad; 2066 } 2067 2068 /* 2069 * If the incoming packet was addressed directly to us (i.e. unicast), 2070 * use dst as the src for the reply. 2071 * The IN6_IFF_NOTREADY case should be VERY rare, but is possible 2072 * (for example) when we encounter an error while forwarding procedure 2073 * destined to a duplicated address of ours. 2074 */ 2075 if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 2076 ia = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */, false); 2077 if (ia != NULL && !(ia->ia6_flags & 2078 (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) { 2079 src6 = ia->ia_addr.sin6_addr; 2080 srcp = &src6; 2081 2082 if (m->m_pkthdr.rcvif != NULL) { 2083 /* XXX: This may not be the outgoing interface */ 2084 hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim; 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 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2137 if (outif) 2138 icmp6_ifoutstat_inc(outif, type, code); 2139 2140 return; 2141 2142 bad: 2143 m_freem(m); 2144 return; 2145 } 2146 2147 static const char * 2148 icmp6_redirect_diag(struct in6_addr *src6, struct in6_addr *dst6, 2149 struct in6_addr *tgt6) 2150 { 2151 static char buf[1024]; 2152 char ip6bufs[INET6_ADDRSTRLEN]; 2153 char ip6bufd[INET6_ADDRSTRLEN]; 2154 char ip6buft[INET6_ADDRSTRLEN]; 2155 snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)", 2156 ip6_sprintf(ip6bufs, src6), ip6_sprintf(ip6bufd, dst6), 2157 ip6_sprintf(ip6buft, tgt6)); 2158 return buf; 2159 } 2160 2161 void 2162 icmp6_redirect_input(struct mbuf *m, int off) 2163 { 2164 struct ifnet *ifp; 2165 struct ip6_hdr *ip6; 2166 struct nd_redirect *nd_rd; 2167 struct in6_addr src6, redtgt6, reddst6; 2168 union nd_opts ndopts; 2169 char ip6buf[INET6_ADDRSTRLEN]; 2170 char *lladdr; 2171 int icmp6len, is_onlink, is_router, lladdrlen; 2172 2173 M_ASSERTPKTHDR(m); 2174 KASSERT(m->m_pkthdr.rcvif != NULL, ("%s: no rcvif", __func__)); 2175 2176 /* XXX if we are router, we don't update route by icmp6 redirect */ 2177 if (V_ip6_forwarding) 2178 goto freeit; 2179 if (!V_icmp6_rediraccept) 2180 goto freeit; 2181 2182 /* RFC 6980: Nodes MUST silently ignore fragments */ 2183 if(m->m_flags & M_FRAGMENTED) 2184 goto freeit; 2185 2186 ip6 = mtod(m, struct ip6_hdr *); 2187 icmp6len = ntohs(ip6->ip6_plen); 2188 if (m->m_len < off + icmp6len) { 2189 m = m_pullup(m, off + icmp6len); 2190 if (m == NULL) { 2191 IP6STAT_INC(ip6s_exthdrtoolong); 2192 return; 2193 } 2194 } 2195 ip6 = mtod(m, struct ip6_hdr *); 2196 nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off); 2197 2198 ifp = m->m_pkthdr.rcvif; 2199 redtgt6 = nd_rd->nd_rd_target; 2200 reddst6 = nd_rd->nd_rd_dst; 2201 2202 if (in6_setscope(&redtgt6, ifp, NULL) || 2203 in6_setscope(&reddst6, ifp, NULL)) { 2204 goto freeit; 2205 } 2206 2207 /* validation */ 2208 src6 = ip6->ip6_src; 2209 if (!IN6_IS_ADDR_LINKLOCAL(&src6)) { 2210 nd6log((LOG_ERR, 2211 "ICMP6 redirect sent from %s rejected; " 2212 "must be from linklocal\n", 2213 ip6_sprintf(ip6buf, &src6))); 2214 goto bad; 2215 } 2216 if (__predict_false(ip6->ip6_hlim != 255)) { 2217 ICMP6STAT_INC(icp6s_invlhlim); 2218 nd6log((LOG_ERR, 2219 "ICMP6 redirect sent from %s rejected; " 2220 "hlim=%d (must be 255)\n", 2221 ip6_sprintf(ip6buf, &src6), ip6->ip6_hlim)); 2222 goto bad; 2223 } 2224 { 2225 /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */ 2226 struct nhop_object *nh; 2227 struct in6_addr kdst; 2228 uint32_t scopeid; 2229 2230 in6_splitscope(&reddst6, &kdst, &scopeid); 2231 NET_EPOCH_ASSERT(); 2232 nh = fib6_lookup(ifp->if_fib, &kdst, scopeid, 0, 0); 2233 if (nh != NULL) { 2234 struct in6_addr nh_addr; 2235 nh_addr = ifatoia6(nh->nh_ifa)->ia_addr.sin6_addr; 2236 if ((nh->nh_flags & NHF_GATEWAY) == 0) { 2237 nd6log((LOG_ERR, 2238 "ICMP6 redirect rejected; no route " 2239 "with inet6 gateway found for redirect dst: %s\n", 2240 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2241 goto bad; 2242 } 2243 2244 /* 2245 * Embed scope zone id into next hop address. 2246 */ 2247 nh_addr = nh->gw6_sa.sin6_addr; 2248 2249 if (IN6_ARE_ADDR_EQUAL(&src6, &nh_addr) == 0) { 2250 nd6log((LOG_ERR, 2251 "ICMP6 redirect rejected; " 2252 "not equal to gw-for-src=%s (must be same): " 2253 "%s\n", 2254 ip6_sprintf(ip6buf, &nh_addr), 2255 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2256 goto bad; 2257 } 2258 } else { 2259 nd6log((LOG_ERR, 2260 "ICMP6 redirect rejected; " 2261 "no route found for redirect dst: %s\n", 2262 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2263 goto bad; 2264 } 2265 } 2266 if (IN6_IS_ADDR_MULTICAST(&reddst6)) { 2267 nd6log((LOG_ERR, 2268 "ICMP6 redirect rejected; " 2269 "redirect dst must be unicast: %s\n", 2270 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2271 goto bad; 2272 } 2273 2274 is_router = is_onlink = 0; 2275 if (IN6_IS_ADDR_LINKLOCAL(&redtgt6)) 2276 is_router = 1; /* router case */ 2277 if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0) 2278 is_onlink = 1; /* on-link destination case */ 2279 if (!is_router && !is_onlink) { 2280 nd6log((LOG_ERR, 2281 "ICMP6 redirect rejected; " 2282 "neither router case nor onlink case: %s\n", 2283 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2284 goto bad; 2285 } 2286 2287 icmp6len -= sizeof(*nd_rd); 2288 nd6_option_init(nd_rd + 1, icmp6len, &ndopts); 2289 if (nd6_options(&ndopts) < 0) { 2290 nd6log((LOG_INFO, "%s: invalid ND option, rejected: %s\n", 2291 __func__, icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2292 /* nd6_options have incremented stats */ 2293 goto freeit; 2294 } 2295 2296 lladdr = NULL; 2297 lladdrlen = 0; 2298 if (ndopts.nd_opts_tgt_lladdr) { 2299 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 2300 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 2301 } 2302 2303 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 2304 nd6log((LOG_INFO, "%s: lladdrlen mismatch for %s " 2305 "(if %d, icmp6 packet %d): %s\n", 2306 __func__, ip6_sprintf(ip6buf, &redtgt6), 2307 ifp->if_addrlen, lladdrlen - 2, 2308 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2309 goto bad; 2310 } 2311 2312 /* Validation passed. */ 2313 2314 /* RFC 2461 8.3 */ 2315 nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT, 2316 is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER); 2317 2318 /* 2319 * Install a gateway route in the better-router case or an interface 2320 * route in the on-link-destination case. 2321 */ 2322 { 2323 struct sockaddr_in6 sdst; 2324 struct sockaddr_in6 sgw; 2325 struct sockaddr_in6 ssrc; 2326 struct sockaddr *gw; 2327 int rt_flags; 2328 u_int fibnum; 2329 2330 bzero(&sdst, sizeof(sdst)); 2331 bzero(&ssrc, sizeof(ssrc)); 2332 sdst.sin6_family = ssrc.sin6_family = AF_INET6; 2333 sdst.sin6_len = ssrc.sin6_len = sizeof(struct sockaddr_in6); 2334 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr)); 2335 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr)); 2336 rt_flags = 0; 2337 if (is_router) { 2338 bzero(&sgw, sizeof(sgw)); 2339 sgw.sin6_family = AF_INET6; 2340 sgw.sin6_len = sizeof(struct sockaddr_in6); 2341 bcopy(&redtgt6, &sgw.sin6_addr, 2342 sizeof(struct in6_addr)); 2343 gw = (struct sockaddr *)&sgw; 2344 rt_flags |= RTF_GATEWAY; 2345 } else 2346 gw = ifp->if_addr->ifa_addr; 2347 for (fibnum = 0; fibnum < rt_numfibs; fibnum++) 2348 rib_add_redirect(fibnum, (struct sockaddr *)&sdst, gw, 2349 (struct sockaddr *)&ssrc, ifp, rt_flags, 2350 V_icmp6_redirtimeout); 2351 } 2352 2353 freeit: 2354 m_freem(m); 2355 return; 2356 2357 bad: 2358 ICMP6STAT_INC(icp6s_badredirect); 2359 m_freem(m); 2360 } 2361 2362 void 2363 icmp6_redirect_output(struct mbuf *m0, struct nhop_object *nh) 2364 { 2365 struct ifnet *ifp; /* my outgoing interface */ 2366 struct in6_addr ifp_ll6; 2367 struct in6_addr *router_ll6; 2368 struct ip6_hdr *sip6; /* m0 as struct ip6_hdr */ 2369 struct mbuf *m = NULL; /* newly allocated one */ 2370 struct m_tag *mtag; 2371 struct ip6_hdr *ip6; /* m as struct ip6_hdr */ 2372 struct nd_redirect *nd_rd; 2373 struct llentry *ln = NULL; 2374 size_t maxlen; 2375 u_char *p; 2376 struct ifnet *outif = NULL; 2377 struct sockaddr_in6 src_sa; 2378 2379 icmp6_errcount(ND_REDIRECT, 0); 2380 2381 /* if we are not router, we don't send icmp6 redirect */ 2382 if (!V_ip6_forwarding) 2383 goto fail; 2384 2385 /* sanity check */ 2386 if (!m0 || !nh || !(NH_IS_VALID(nh)) || !(ifp = nh->nh_ifp)) 2387 goto fail; 2388 2389 /* 2390 * Address check: 2391 * the source address must identify a neighbor, and 2392 * the destination address must not be a multicast address 2393 * [RFC 2461, sec 8.2] 2394 */ 2395 sip6 = mtod(m0, struct ip6_hdr *); 2396 bzero(&src_sa, sizeof(src_sa)); 2397 src_sa.sin6_family = AF_INET6; 2398 src_sa.sin6_len = sizeof(src_sa); 2399 src_sa.sin6_addr = sip6->ip6_src; 2400 if (nd6_is_addr_neighbor(&src_sa, ifp) == 0) 2401 goto fail; 2402 if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst)) 2403 goto fail; /* what should we do here? */ 2404 2405 /* rate limit */ 2406 if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0)) 2407 goto fail; 2408 2409 /* 2410 * Since we are going to append up to 1280 bytes (= IPV6_MMTU), 2411 * we almost always ask for an mbuf cluster for simplicity. 2412 * (MHLEN < IPV6_MMTU is almost always true) 2413 */ 2414 #if IPV6_MMTU >= MCLBYTES 2415 # error assumption failed about IPV6_MMTU and MCLBYTES 2416 #endif 2417 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 2418 if (m == NULL) 2419 goto fail; 2420 M_SETFIB(m, M_GETFIB(m0)); 2421 maxlen = M_TRAILINGSPACE(m); 2422 maxlen = min(IPV6_MMTU, maxlen); 2423 /* just for safety */ 2424 if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) + 2425 ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) { 2426 goto fail; 2427 } 2428 2429 { 2430 /* get ip6 linklocal address for ifp(my outgoing interface). */ 2431 struct in6_ifaddr *ia; 2432 if ((ia = in6ifa_ifpforlinklocal(ifp, 2433 IN6_IFF_NOTREADY| 2434 IN6_IFF_ANYCAST)) == NULL) 2435 goto fail; 2436 bcopy(&ia->ia_addr.sin6_addr, &ifp_ll6, sizeof(ifp_ll6)); 2437 ifa_free(&ia->ia_ifa); 2438 } 2439 2440 /* get ip6 linklocal address for the router. */ 2441 if (nh->nh_flags & NHF_GATEWAY) { 2442 struct sockaddr_in6 *sin6; 2443 sin6 = &nh->gw6_sa; 2444 router_ll6 = &sin6->sin6_addr; 2445 if (!IN6_IS_ADDR_LINKLOCAL(router_ll6)) 2446 router_ll6 = (struct in6_addr *)NULL; 2447 } else 2448 router_ll6 = (struct in6_addr *)NULL; 2449 2450 /* ip6 */ 2451 ip6 = mtod(m, struct ip6_hdr *); 2452 ip6->ip6_flow = 0; 2453 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2454 ip6->ip6_vfc |= IPV6_VERSION; 2455 /* ip6->ip6_plen will be set later */ 2456 ip6->ip6_nxt = IPPROTO_ICMPV6; 2457 ip6->ip6_hlim = 255; 2458 /* ip6->ip6_src must be linklocal addr for my outgoing if. */ 2459 bcopy(&ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr)); 2460 bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr)); 2461 2462 /* ND Redirect */ 2463 nd_rd = (struct nd_redirect *)(ip6 + 1); 2464 nd_rd->nd_rd_type = ND_REDIRECT; 2465 nd_rd->nd_rd_code = 0; 2466 nd_rd->nd_rd_reserved = 0; 2467 if (nh->nh_flags & NHF_GATEWAY) { 2468 /* 2469 * nd_rd->nd_rd_target must be a link-local address in 2470 * better router cases. 2471 */ 2472 if (!router_ll6) 2473 goto fail; 2474 bcopy(router_ll6, &nd_rd->nd_rd_target, 2475 sizeof(nd_rd->nd_rd_target)); 2476 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2477 sizeof(nd_rd->nd_rd_dst)); 2478 } else { 2479 /* make sure redtgt == reddst */ 2480 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target, 2481 sizeof(nd_rd->nd_rd_target)); 2482 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2483 sizeof(nd_rd->nd_rd_dst)); 2484 } 2485 2486 p = (u_char *)(nd_rd + 1); 2487 2488 if (!router_ll6) 2489 goto nolladdropt; 2490 2491 { 2492 /* target lladdr option */ 2493 int len; 2494 struct nd_opt_hdr *nd_opt; 2495 char *lladdr; 2496 2497 ln = nd6_lookup(router_ll6, LLE_SF(AF_INET6, 0), ifp); 2498 if (ln == NULL) 2499 goto nolladdropt; 2500 2501 len = sizeof(*nd_opt) + ifp->if_addrlen; 2502 len = (len + 7) & ~7; /* round by 8 */ 2503 /* safety check */ 2504 if (len + (p - (u_char *)ip6) > maxlen) 2505 goto nolladdropt; 2506 2507 if (ln->la_flags & LLE_VALID) { 2508 nd_opt = (struct nd_opt_hdr *)p; 2509 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 2510 nd_opt->nd_opt_len = len >> 3; 2511 lladdr = (char *)(nd_opt + 1); 2512 bcopy(ln->ll_addr, lladdr, ifp->if_addrlen); 2513 p += len; 2514 } 2515 } 2516 nolladdropt: 2517 if (ln != NULL) 2518 LLE_RUNLOCK(ln); 2519 2520 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2521 2522 /* just to be safe */ 2523 #ifdef M_DECRYPTED /*not openbsd*/ 2524 if (m0->m_flags & M_DECRYPTED) 2525 goto noredhdropt; 2526 #endif 2527 if (p - (u_char *)ip6 > maxlen) 2528 goto noredhdropt; 2529 2530 { 2531 /* redirected header option */ 2532 int len; 2533 struct nd_opt_rd_hdr *nd_opt_rh; 2534 2535 /* 2536 * compute the maximum size for icmp6 redirect header option. 2537 * XXX room for auth header? 2538 */ 2539 len = maxlen - (p - (u_char *)ip6); 2540 len &= ~7; 2541 2542 /* This is just for simplicity. */ 2543 if (m0->m_pkthdr.len != m0->m_len) { 2544 if (m0->m_next) { 2545 m_freem(m0->m_next); 2546 m0->m_next = NULL; 2547 } 2548 m0->m_pkthdr.len = m0->m_len; 2549 } 2550 2551 /* 2552 * Redirected header option spec (RFC2461 4.6.3) talks nothing 2553 * about padding/truncate rule for the original IP packet. 2554 * From the discussion on IPv6imp in Feb 1999, 2555 * the consensus was: 2556 * - "attach as much as possible" is the goal 2557 * - pad if not aligned (original size can be guessed by 2558 * original ip6 header) 2559 * Following code adds the padding if it is simple enough, 2560 * and truncates if not. 2561 */ 2562 if (m0->m_next || m0->m_pkthdr.len != m0->m_len) 2563 panic("assumption failed in %s:%d", __FILE__, 2564 __LINE__); 2565 2566 if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) { 2567 /* not enough room, truncate */ 2568 m0->m_pkthdr.len = m0->m_len = len - 2569 sizeof(*nd_opt_rh); 2570 } else { 2571 /* enough room, pad or truncate */ 2572 size_t extra; 2573 2574 extra = m0->m_pkthdr.len % 8; 2575 if (extra) { 2576 /* pad if easy enough, truncate if not */ 2577 if (8 - extra <= M_TRAILINGSPACE(m0)) { 2578 /* pad */ 2579 bzero(m0->m_data + m0->m_len, 8 - extra); 2580 m0->m_len += (8 - extra); 2581 m0->m_pkthdr.len += (8 - extra); 2582 } else { 2583 /* truncate */ 2584 m0->m_pkthdr.len -= extra; 2585 m0->m_len -= extra; 2586 } 2587 } 2588 len = m0->m_pkthdr.len + sizeof(*nd_opt_rh); 2589 m0->m_pkthdr.len = m0->m_len = len - 2590 sizeof(*nd_opt_rh); 2591 } 2592 2593 nd_opt_rh = (struct nd_opt_rd_hdr *)p; 2594 bzero(nd_opt_rh, sizeof(*nd_opt_rh)); 2595 nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER; 2596 nd_opt_rh->nd_opt_rh_len = len >> 3; 2597 p += sizeof(*nd_opt_rh); 2598 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2599 2600 /* connect m0 to m */ 2601 m_tag_delete_chain(m0, NULL); 2602 m0->m_flags &= ~M_PKTHDR; 2603 m->m_next = m0; 2604 m->m_pkthdr.len = m->m_len + m0->m_len; 2605 m0 = NULL; 2606 } 2607 noredhdropt:; 2608 if (m0) { 2609 m_freem(m0); 2610 m0 = NULL; 2611 } 2612 2613 /* XXX: clear embedded link IDs in the inner header */ 2614 in6_clearscope(&sip6->ip6_src); 2615 in6_clearscope(&sip6->ip6_dst); 2616 in6_clearscope(&nd_rd->nd_rd_target); 2617 in6_clearscope(&nd_rd->nd_rd_dst); 2618 2619 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr)); 2620 2621 nd_rd->nd_rd_cksum = 0; 2622 nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2623 sizeof(*ip6), ntohs(ip6->ip6_plen)); 2624 2625 if (send_sendso_input_hook != NULL) { 2626 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, sizeof(unsigned short), 2627 M_NOWAIT); 2628 if (mtag == NULL) 2629 goto fail; 2630 *(unsigned short *)(mtag + 1) = nd_rd->nd_rd_type; 2631 m_tag_prepend(m, mtag); 2632 } 2633 2634 /* send the packet to outside... */ 2635 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2636 if (outif) { 2637 icmp6_ifstat_inc(outif, ifs6_out_msg); 2638 icmp6_ifstat_inc(outif, ifs6_out_redirect); 2639 } 2640 ICMP6STAT_INC2(icp6s_outhist, ND_REDIRECT); 2641 2642 return; 2643 2644 fail: 2645 if (m) 2646 m_freem(m); 2647 if (m0) 2648 m_freem(m0); 2649 } 2650 2651 /* 2652 * ICMPv6 socket option processing. 2653 */ 2654 int 2655 icmp6_ctloutput(struct socket *so, struct sockopt *sopt) 2656 { 2657 int error = 0; 2658 int optlen; 2659 struct inpcb *inp = sotoinpcb(so); 2660 int level, op, optname; 2661 2662 if (sopt) { 2663 level = sopt->sopt_level; 2664 op = sopt->sopt_dir; 2665 optname = sopt->sopt_name; 2666 optlen = sopt->sopt_valsize; 2667 } else 2668 level = op = optname = optlen = 0; 2669 2670 if (level != IPPROTO_ICMPV6) { 2671 return EINVAL; 2672 } 2673 2674 switch (op) { 2675 case SOPT_SET: 2676 switch (optname) { 2677 case ICMP6_FILTER: 2678 { 2679 struct icmp6_filter ic6f; 2680 2681 if (optlen != sizeof(ic6f)) { 2682 error = EMSGSIZE; 2683 break; 2684 } 2685 error = sooptcopyin(sopt, &ic6f, optlen, optlen); 2686 if (error == 0) { 2687 INP_WLOCK(inp); 2688 *inp->in6p_icmp6filt = ic6f; 2689 INP_WUNLOCK(inp); 2690 } 2691 break; 2692 } 2693 2694 default: 2695 error = ENOPROTOOPT; 2696 break; 2697 } 2698 break; 2699 2700 case SOPT_GET: 2701 switch (optname) { 2702 case ICMP6_FILTER: 2703 { 2704 struct icmp6_filter ic6f; 2705 2706 INP_RLOCK(inp); 2707 ic6f = *inp->in6p_icmp6filt; 2708 INP_RUNLOCK(inp); 2709 error = sooptcopyout(sopt, &ic6f, sizeof(ic6f)); 2710 break; 2711 } 2712 2713 default: 2714 error = ENOPROTOOPT; 2715 break; 2716 } 2717 break; 2718 } 2719 2720 return (error); 2721 } 2722 2723 static int sysctl_icmp6lim_and_jitter(SYSCTL_HANDLER_ARGS); 2724 VNET_DEFINE_STATIC(u_int, icmp6errppslim) = 100; 2725 #define V_icmp6errppslim VNET(icmp6errppslim) 2726 SYSCTL_PROC(_net_inet6_icmp6, ICMPV6CTL_ERRPPSLIMIT, errppslimit, 2727 CTLTYPE_UINT | CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(icmp6errppslim), 0, 2728 &sysctl_icmp6lim_and_jitter, "IU", 2729 "Maximum number of ICMPv6 error/reply messages per second"); 2730 2731 typedef enum { 2732 RATELIM_PARAM_PROB = 0, 2733 RATELIM_TOO_BIG, 2734 RATELIM_UNREACH, 2735 RATELIM_TEXCEED, 2736 RATELIM_REDIR, 2737 RATELIM_REPLY, 2738 RATELIM_OTHER, 2739 RATELIM_MAX 2740 } ratelim_which; 2741 2742 static const char *icmp6_rate_descrs[RATELIM_MAX] = { 2743 [RATELIM_PARAM_PROB] = "bad IPv6 header", 2744 [RATELIM_TOO_BIG] = "packet too big", 2745 [RATELIM_UNREACH] = "destination unreachable", 2746 [RATELIM_TEXCEED] = "time exceeded", 2747 [RATELIM_REPLY] = "echo reply", 2748 [RATELIM_REDIR] = "neighbor discovery redirect", 2749 [RATELIM_OTHER] = "(other)", 2750 }; 2751 2752 VNET_DEFINE_STATIC(int, icmp6lim_curr_jitter[RATELIM_MAX]) = {0}; 2753 #define V_icmp6lim_curr_jitter VNET(icmp6lim_curr_jitter) 2754 2755 VNET_DEFINE_STATIC(u_int, icmp6lim_jitter) = 8; 2756 #define V_icmp6lim_jitter VNET(icmp6lim_jitter) 2757 SYSCTL_PROC(_net_inet6_icmp6, OID_AUTO, icmp6lim_jitter, CTLTYPE_UINT | 2758 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(icmp6lim_jitter), 0, 2759 &sysctl_icmp6lim_and_jitter, "IU", 2760 "Random errppslimit jitter adjustment limit"); 2761 2762 VNET_DEFINE_STATIC(int, icmp6lim_output) = 1; 2763 #define V_icmp6lim_output VNET(icmp6lim_output) 2764 SYSCTL_INT(_net_inet6_icmp6, OID_AUTO, icmp6lim_output, 2765 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(icmp6lim_output), 0, 2766 "Enable logging of ICMPv6 response rate limiting"); 2767 2768 static void 2769 icmp6lim_new_jitter(int which) 2770 { 2771 /* 2772 * Adjust limit +/- to jitter the measurement to deny a side-channel 2773 * port scan as in https://dl.acm.org/doi/10.1145/3372297.3417280 2774 */ 2775 KASSERT(which >= 0 && which < RATELIM_MAX, 2776 ("%s: which %d", __func__, which)); 2777 if (V_icmp6lim_jitter > 0) 2778 V_icmp6lim_curr_jitter[which] = 2779 arc4random_uniform(V_icmp6lim_jitter * 2 + 1) - 2780 V_icmp6lim_jitter; 2781 } 2782 2783 static int 2784 sysctl_icmp6lim_and_jitter(SYSCTL_HANDLER_ARGS) 2785 { 2786 uint32_t new; 2787 int error; 2788 bool lim; 2789 2790 MPASS(oidp->oid_arg1 == &VNET_NAME(icmp6errppslim) || 2791 oidp->oid_arg1 == &VNET_NAME(icmp6lim_jitter)); 2792 2793 lim = (oidp->oid_arg1 == &VNET_NAME(icmp6errppslim)); 2794 new = lim ? V_icmp6errppslim : V_icmp6lim_jitter; 2795 error = sysctl_handle_int(oidp, &new, 0, req); 2796 if (error == 0 && req->newptr) { 2797 if (lim) { 2798 if (new != 0 && new <= V_icmp6lim_jitter) 2799 error = EINVAL; 2800 else 2801 V_icmp6errppslim = new; 2802 } else { 2803 if (new >= V_icmp6errppslim) 2804 error = EINVAL; 2805 else { 2806 V_icmp6lim_jitter = new; 2807 for (int i = 0; i < RATELIM_MAX; i++) { 2808 icmp6lim_new_jitter(i); 2809 } 2810 } 2811 } 2812 } 2813 MPASS(V_icmp6errppslim == 0 || V_icmp6errppslim > V_icmp6lim_jitter); 2814 2815 return (error); 2816 } 2817 2818 2819 VNET_DEFINE_STATIC(struct counter_rate *, icmp6_rates[RATELIM_MAX]); 2820 #define V_icmp6_rates VNET(icmp6_rates) 2821 2822 static void 2823 icmp6_ratelimit_init(void) 2824 { 2825 2826 for (int i = 0; i < RATELIM_MAX; i++) { 2827 V_icmp6_rates[i] = counter_rate_alloc(M_WAITOK, 1); 2828 icmp6lim_new_jitter(i); 2829 } 2830 } 2831 VNET_SYSINIT(icmp6_ratelimit, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY, 2832 icmp6_ratelimit_init, NULL); 2833 2834 #ifdef VIMAGE 2835 static void 2836 icmp6_ratelimit_uninit(void) 2837 { 2838 2839 for (int i = 0; i < RATELIM_MAX; i++) 2840 counter_rate_free(V_icmp6_rates[i]); 2841 } 2842 VNET_SYSUNINIT(icmp6_ratelimit, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD, 2843 icmp6_ratelimit_uninit, NULL); 2844 #endif 2845 2846 /* 2847 * Perform rate limit check. 2848 * Returns 0 if it is okay to send the icmp6 packet. 2849 * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate 2850 * limitation. 2851 * 2852 * XXX per-destination/type check necessary? 2853 * 2854 * dst - not used at this moment 2855 * code - not used at this moment 2856 */ 2857 int 2858 icmp6_ratelimit(const struct in6_addr *dst, const int type, const int code) 2859 { 2860 ratelim_which which; 2861 int64_t pps; 2862 2863 if (V_icmp6errppslim == 0) 2864 return (0); 2865 2866 switch (type) { 2867 case ICMP6_PARAM_PROB: 2868 which = RATELIM_PARAM_PROB; 2869 break; 2870 case ICMP6_PACKET_TOO_BIG: 2871 which = RATELIM_TOO_BIG; 2872 break; 2873 case ICMP6_DST_UNREACH: 2874 which = RATELIM_UNREACH; 2875 break; 2876 case ICMP6_TIME_EXCEEDED: 2877 which = RATELIM_TEXCEED; 2878 break; 2879 case ND_REDIRECT: 2880 which = RATELIM_REDIR; 2881 break; 2882 case ICMP6_ECHO_REPLY: 2883 which = RATELIM_REPLY; 2884 break; 2885 default: 2886 which = RATELIM_OTHER; 2887 break; 2888 }; 2889 2890 pps = counter_ratecheck(V_icmp6_rates[which], V_icmp6errppslim + 2891 V_icmp6lim_curr_jitter[which]); 2892 if (pps > 0) { 2893 if (V_icmp6lim_output) 2894 log(LOG_NOTICE, "Limiting ICMPv6 %s output from %jd " 2895 "to %d packets/sec\n", icmp6_rate_descrs[which], 2896 (intmax_t )pps, V_icmp6errppslim + 2897 V_icmp6lim_curr_jitter[which]); 2898 icmp6lim_new_jitter(which); 2899 } 2900 if (pps == -1) { 2901 ICMP6STAT_INC(icp6s_toofreq); 2902 return (-1); 2903 } 2904 2905 return (0); 2906 } 2907