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); 162 163 /* 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, 1); /*XXX*/ 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 void 1134 icmp6_mtudisc_update(struct ip6ctlparam *ip6cp, int validated) 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; /* will be necessary for scope issue */ 1139 u_int mtu = ntohl(icmp6->icmp6_mtu); 1140 struct in_conninfo inc; 1141 uint32_t max_mtu; 1142 1143 #if 0 1144 /* 1145 * RFC2460 section 5, last paragraph. 1146 * even though minimum link MTU for IPv6 is IPV6_MMTU, 1147 * we may see ICMPv6 too big with mtu < IPV6_MMTU 1148 * due to packet translator in the middle. 1149 * see ip6_output() and ip6_getpmtu() "alwaysfrag" case for 1150 * special handling. 1151 */ 1152 if (mtu < IPV6_MMTU) 1153 return; 1154 #endif 1155 1156 /* 1157 * we reject ICMPv6 too big with abnormally small value. 1158 * XXX what is the good definition of "abnormally small"? 1159 */ 1160 if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8) 1161 return; 1162 1163 if (!validated) 1164 return; 1165 1166 /* 1167 * In case the suggested mtu is less than IPV6_MMTU, we 1168 * only need to remember that it was for above mentioned 1169 * "alwaysfrag" case. 1170 * Try to be as close to the spec as possible. 1171 */ 1172 if (mtu < IPV6_MMTU) 1173 mtu = IPV6_MMTU - 8; 1174 1175 bzero(&inc, sizeof(inc)); 1176 inc.inc_fibnum = M_GETFIB(m); 1177 inc.inc_flags |= INC_ISIPV6; 1178 inc.inc6_faddr = *dst; 1179 if (in6_setscope(&inc.inc6_faddr, m->m_pkthdr.rcvif, NULL)) 1180 return; 1181 1182 max_mtu = tcp_hc_getmtu(&inc); 1183 if (max_mtu == 0) 1184 max_mtu = tcp_maxmtu6(&inc, NULL); 1185 1186 if (mtu < max_mtu) { 1187 tcp_hc_updatemtu(&inc, mtu); 1188 ICMP6STAT_INC(icp6s_pmtuchg); 1189 } 1190 } 1191 1192 /* 1193 * Process a Node Information Query packet, based on 1194 * draft-ietf-ipngwg-icmp-name-lookups-07. 1195 * 1196 * Spec incompatibilities: 1197 * - IPv6 Subject address handling 1198 * - IPv4 Subject address handling support missing 1199 * - Proxy reply (answer even if it's not for me) 1200 * - joins NI group address at in6_ifattach() time only, does not cope 1201 * with hostname changes by sethostname(3) 1202 */ 1203 static struct mbuf * 1204 ni6_input(struct mbuf *m, int off, struct prison *pr) 1205 { 1206 struct icmp6_nodeinfo *ni6, *nni6; 1207 struct mbuf *n = NULL; 1208 u_int16_t qtype; 1209 int subjlen; 1210 int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); 1211 struct ni_reply_fqdn *fqdn; 1212 int addrs; /* for NI_QTYPE_NODEADDR */ 1213 struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */ 1214 struct in6_addr in6_subj; /* subject address */ 1215 struct ip6_hdr *ip6; 1216 int oldfqdn = 0; /* if 1, return pascal string (03 draft) */ 1217 char *subj = NULL; 1218 struct in6_ifaddr *ia6 = NULL; 1219 1220 ip6 = mtod(m, struct ip6_hdr *); 1221 ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off); 1222 1223 /* 1224 * Validate IPv6 source address. 1225 * The default configuration MUST be to refuse answering queries from 1226 * global-scope addresses according to RFC4602. 1227 * Notes: 1228 * - it's not very clear what "refuse" means; this implementation 1229 * simply drops it. 1230 * - it's not very easy to identify global-scope (unicast) addresses 1231 * since there are many prefixes for them. It should be safer 1232 * and in practice sufficient to check "all" but loopback and 1233 * link-local (note that site-local unicast was deprecated and 1234 * ULA is defined as global scope-wise) 1235 */ 1236 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_GLOBALOK) == 0 && 1237 !IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) && 1238 !IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) 1239 goto bad; 1240 1241 /* 1242 * Validate IPv6 destination address. 1243 * 1244 * The Responder must discard the Query without further processing 1245 * unless it is one of the Responder's unicast or anycast addresses, or 1246 * a link-local scope multicast address which the Responder has joined. 1247 * [RFC4602, Section 5.] 1248 */ 1249 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 1250 if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst)) 1251 goto bad; 1252 /* else it's a link-local multicast, fine */ 1253 } else { /* unicast or anycast */ 1254 ia6 = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */, false); 1255 if (ia6 == NULL) 1256 goto bad; /* XXX impossible */ 1257 1258 if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) && 1259 !(V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK)) { 1260 nd6log((LOG_DEBUG, "ni6_input: ignore node info to " 1261 "a temporary address in %s:%d", 1262 __FILE__, __LINE__)); 1263 goto bad; 1264 } 1265 } 1266 1267 /* validate query Subject field. */ 1268 qtype = ntohs(ni6->ni_qtype); 1269 subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo); 1270 switch (qtype) { 1271 case NI_QTYPE_NOOP: 1272 case NI_QTYPE_SUPTYPES: 1273 /* 07 draft */ 1274 if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0) 1275 break; 1276 /* FALLTHROUGH */ 1277 case NI_QTYPE_FQDN: 1278 case NI_QTYPE_NODEADDR: 1279 case NI_QTYPE_IPV4ADDR: 1280 switch (ni6->ni_code) { 1281 case ICMP6_NI_SUBJ_IPV6: 1282 #if ICMP6_NI_SUBJ_IPV6 != 0 1283 case 0: 1284 #endif 1285 /* 1286 * backward compatibility - try to accept 03 draft 1287 * format, where no Subject is present. 1288 */ 1289 if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 && 1290 subjlen == 0) { 1291 oldfqdn++; 1292 break; 1293 } 1294 #if ICMP6_NI_SUBJ_IPV6 != 0 1295 if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6) 1296 goto bad; 1297 #endif 1298 1299 if (subjlen != sizeof(struct in6_addr)) 1300 goto bad; 1301 1302 /* 1303 * Validate Subject address. 1304 * 1305 * Not sure what exactly "address belongs to the node" 1306 * means in the spec, is it just unicast, or what? 1307 * 1308 * At this moment we consider Subject address as 1309 * "belong to the node" if the Subject address equals 1310 * to the IPv6 destination address; validation for 1311 * IPv6 destination address should have done enough 1312 * check for us. 1313 * 1314 * We do not do proxy at this moment. 1315 */ 1316 m_copydata(m, off + sizeof(struct icmp6_nodeinfo), 1317 subjlen, (caddr_t)&in6_subj); 1318 if (in6_setscope(&in6_subj, m->m_pkthdr.rcvif, NULL)) 1319 goto bad; 1320 1321 subj = (char *)&in6_subj; 1322 if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &in6_subj)) 1323 break; 1324 1325 /* 1326 * XXX if we are to allow other cases, we should really 1327 * be careful about scope here. 1328 * basically, we should disallow queries toward IPv6 1329 * destination X with subject Y, 1330 * if scope(X) > scope(Y). 1331 * if we allow scope(X) > scope(Y), it will result in 1332 * information leakage across scope boundary. 1333 */ 1334 goto bad; 1335 1336 case ICMP6_NI_SUBJ_FQDN: 1337 /* 1338 * Validate Subject name with gethostname(3). 1339 * 1340 * The behavior may need some debate, since: 1341 * - we are not sure if the node has FQDN as 1342 * hostname (returned by gethostname(3)). 1343 * - the code does wildcard match for truncated names. 1344 * however, we are not sure if we want to perform 1345 * wildcard match, if gethostname(3) side has 1346 * truncated hostname. 1347 */ 1348 mtx_lock(&pr->pr_mtx); 1349 n = ni6_nametodns(pr->pr_hostname, 1350 strlen(pr->pr_hostname), 0); 1351 mtx_unlock(&pr->pr_mtx); 1352 if (!n || n->m_next || n->m_len == 0) 1353 goto bad; 1354 if (m->m_len < off + sizeof(struct icmp6_nodeinfo) + 1355 subjlen) { 1356 m = m_pullup(m, off + 1357 sizeof(struct icmp6_nodeinfo) + subjlen); 1358 if (m == NULL) { 1359 IP6STAT_INC(ip6s_exthdrtoolong); 1360 goto bad; 1361 } 1362 } 1363 /* ip6 possibly invalid but not used after. */ 1364 ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off); 1365 subj = (char *)(mtod(m, caddr_t) + off + 1366 sizeof(struct icmp6_nodeinfo)); 1367 if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *), 1368 n->m_len)) { 1369 goto bad; 1370 } 1371 m_freem(n); 1372 n = NULL; 1373 break; 1374 1375 case ICMP6_NI_SUBJ_IPV4: /* XXX: to be implemented? */ 1376 default: 1377 goto bad; 1378 } 1379 break; 1380 } 1381 1382 /* refuse based on configuration. XXX ICMP6_NI_REFUSED? */ 1383 switch (qtype) { 1384 case NI_QTYPE_FQDN: 1385 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_FQDNOK) == 0) 1386 goto bad; 1387 break; 1388 case NI_QTYPE_NODEADDR: 1389 case NI_QTYPE_IPV4ADDR: 1390 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_NODEADDROK) == 0) 1391 goto bad; 1392 break; 1393 } 1394 1395 /* guess reply length */ 1396 switch (qtype) { 1397 case NI_QTYPE_NOOP: 1398 break; /* no reply data */ 1399 case NI_QTYPE_SUPTYPES: 1400 replylen += sizeof(u_int32_t); 1401 break; 1402 case NI_QTYPE_FQDN: 1403 /* XXX will append an mbuf */ 1404 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); 1405 break; 1406 case NI_QTYPE_NODEADDR: 1407 addrs = ni6_addrs(ni6, m, &ifp, (struct in6_addr *)subj); 1408 if ((replylen += addrs * (sizeof(struct in6_addr) + 1409 sizeof(u_int32_t))) > MCLBYTES) 1410 replylen = MCLBYTES; /* XXX: will truncate pkt later */ 1411 break; 1412 case NI_QTYPE_IPV4ADDR: 1413 /* unsupported - should respond with unknown Qtype? */ 1414 break; 1415 default: 1416 /* 1417 * XXX: We must return a reply with the ICMP6 code 1418 * `unknown Qtype' in this case. However we regard the case 1419 * as an FQDN query for backward compatibility. 1420 * Older versions set a random value to this field, 1421 * so it rarely varies in the defined qtypes. 1422 * But the mechanism is not reliable... 1423 * maybe we should obsolete older versions. 1424 */ 1425 qtype = NI_QTYPE_FQDN; 1426 /* XXX will append an mbuf */ 1427 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); 1428 oldfqdn++; 1429 break; 1430 } 1431 1432 /* Allocate an mbuf to reply. */ 1433 if (replylen > MCLBYTES) { 1434 /* 1435 * XXX: should we try to allocate more? But MCLBYTES 1436 * is probably much larger than IPV6_MMTU... 1437 */ 1438 goto bad; 1439 } 1440 if (replylen > MHLEN) 1441 n = m_getcl(M_NOWAIT, m->m_type, M_PKTHDR); 1442 else 1443 n = m_gethdr(M_NOWAIT, m->m_type); 1444 if (n == NULL) { 1445 m_freem(m); 1446 return (NULL); 1447 } 1448 m_move_pkthdr(n, m); /* just for recvif and FIB */ 1449 n->m_pkthdr.len = n->m_len = replylen; 1450 1451 /* copy mbuf header and IPv6 + Node Information base headers */ 1452 bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr)); 1453 nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1); 1454 bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo)); 1455 1456 /* qtype dependent procedure */ 1457 switch (qtype) { 1458 case NI_QTYPE_NOOP: 1459 nni6->ni_code = ICMP6_NI_SUCCESS; 1460 nni6->ni_flags = 0; 1461 break; 1462 case NI_QTYPE_SUPTYPES: 1463 { 1464 u_int32_t v; 1465 nni6->ni_code = ICMP6_NI_SUCCESS; 1466 nni6->ni_flags = htons(0x0000); /* raw bitmap */ 1467 /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */ 1468 v = (u_int32_t)htonl(0x0000000f); 1469 bcopy(&v, nni6 + 1, sizeof(u_int32_t)); 1470 break; 1471 } 1472 case NI_QTYPE_FQDN: 1473 nni6->ni_code = ICMP6_NI_SUCCESS; 1474 fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) + 1475 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo)); 1476 nni6->ni_flags = 0; /* XXX: meaningless TTL */ 1477 fqdn->ni_fqdn_ttl = 0; /* ditto. */ 1478 /* 1479 * XXX do we really have FQDN in hostname? 1480 */ 1481 mtx_lock(&pr->pr_mtx); 1482 n->m_next = ni6_nametodns(pr->pr_hostname, 1483 strlen(pr->pr_hostname), oldfqdn); 1484 mtx_unlock(&pr->pr_mtx); 1485 if (n->m_next == NULL) 1486 goto bad; 1487 /* XXX we assume that n->m_next is not a chain */ 1488 if (n->m_next->m_next != NULL) 1489 goto bad; 1490 n->m_pkthdr.len += n->m_next->m_len; 1491 break; 1492 case NI_QTYPE_NODEADDR: 1493 { 1494 int lenlim, copied; 1495 1496 nni6->ni_code = ICMP6_NI_SUCCESS; 1497 n->m_pkthdr.len = n->m_len = 1498 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); 1499 lenlim = M_TRAILINGSPACE(n); 1500 copied = ni6_store_addrs(ni6, nni6, ifp, lenlim); 1501 /* XXX: reset mbuf length */ 1502 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + 1503 sizeof(struct icmp6_nodeinfo) + copied; 1504 break; 1505 } 1506 default: 1507 break; /* XXX impossible! */ 1508 } 1509 1510 nni6->ni_type = ICMP6_NI_REPLY; 1511 m_freem(m); 1512 return (n); 1513 1514 bad: 1515 m_freem(m); 1516 if (n) 1517 m_freem(n); 1518 return (NULL); 1519 } 1520 1521 /* 1522 * make a mbuf with DNS-encoded string. no compression support. 1523 * 1524 * XXX names with less than 2 dots (like "foo" or "foo.section") will be 1525 * treated as truncated name (two \0 at the end). this is a wild guess. 1526 * 1527 * old - return pascal string if non-zero 1528 */ 1529 static struct mbuf * 1530 ni6_nametodns(const char *name, int namelen, int old) 1531 { 1532 struct mbuf *m; 1533 char *cp, *ep; 1534 const char *p, *q; 1535 int i, len, nterm; 1536 1537 if (old) 1538 len = namelen + 1; 1539 else 1540 len = MCLBYTES; 1541 1542 /* Because MAXHOSTNAMELEN is usually 256, we use cluster mbuf. */ 1543 if (len > MLEN) 1544 m = m_getcl(M_NOWAIT, MT_DATA, 0); 1545 else 1546 m = m_get(M_NOWAIT, MT_DATA); 1547 if (m == NULL) 1548 goto fail; 1549 1550 if (old) { 1551 m->m_len = len; 1552 *mtod(m, char *) = namelen; 1553 bcopy(name, mtod(m, char *) + 1, namelen); 1554 return m; 1555 } else { 1556 m->m_len = 0; 1557 cp = mtod(m, char *); 1558 ep = mtod(m, char *) + M_TRAILINGSPACE(m); 1559 1560 /* if not certain about my name, return empty buffer */ 1561 if (namelen == 0) 1562 return m; 1563 1564 /* 1565 * guess if it looks like shortened hostname, or FQDN. 1566 * shortened hostname needs two trailing "\0". 1567 */ 1568 i = 0; 1569 for (p = name; p < name + namelen; p++) { 1570 if (*p && *p == '.') 1571 i++; 1572 } 1573 if (i < 2) 1574 nterm = 2; 1575 else 1576 nterm = 1; 1577 1578 p = name; 1579 while (cp < ep && p < name + namelen) { 1580 i = 0; 1581 for (q = p; q < name + namelen && *q && *q != '.'; q++) 1582 i++; 1583 /* result does not fit into mbuf */ 1584 if (cp + i + 1 >= ep) 1585 goto fail; 1586 /* 1587 * DNS label length restriction, RFC1035 page 8. 1588 * "i == 0" case is included here to avoid returning 1589 * 0-length label on "foo..bar". 1590 */ 1591 if (i <= 0 || i >= 64) 1592 goto fail; 1593 *cp++ = i; 1594 bcopy(p, cp, i); 1595 cp += i; 1596 p = q; 1597 if (p < name + namelen && *p == '.') 1598 p++; 1599 } 1600 /* termination */ 1601 if (cp + nterm >= ep) 1602 goto fail; 1603 while (nterm-- > 0) 1604 *cp++ = '\0'; 1605 m->m_len = cp - mtod(m, char *); 1606 return m; 1607 } 1608 1609 panic("should not reach here"); 1610 /* NOTREACHED */ 1611 1612 fail: 1613 if (m) 1614 m_freem(m); 1615 return NULL; 1616 } 1617 1618 /* 1619 * check if two DNS-encoded string matches. takes care of truncated 1620 * form (with \0\0 at the end). no compression support. 1621 * XXX upper/lowercase match (see RFC2065) 1622 */ 1623 static int 1624 ni6_dnsmatch(const char *a, int alen, const char *b, int blen) 1625 { 1626 const char *a0, *b0; 1627 int l; 1628 1629 /* simplest case - need validation? */ 1630 if (alen == blen && bcmp(a, b, alen) == 0) 1631 return 1; 1632 1633 a0 = a; 1634 b0 = b; 1635 1636 /* termination is mandatory */ 1637 if (alen < 2 || blen < 2) 1638 return 0; 1639 if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0') 1640 return 0; 1641 alen--; 1642 blen--; 1643 1644 while (a - a0 < alen && b - b0 < blen) { 1645 if (a - a0 + 1 > alen || b - b0 + 1 > blen) 1646 return 0; 1647 1648 if ((signed char)a[0] < 0 || (signed char)b[0] < 0) 1649 return 0; 1650 /* we don't support compression yet */ 1651 if (a[0] >= 64 || b[0] >= 64) 1652 return 0; 1653 1654 /* truncated case */ 1655 if (a[0] == 0 && a - a0 == alen - 1) 1656 return 1; 1657 if (b[0] == 0 && b - b0 == blen - 1) 1658 return 1; 1659 if (a[0] == 0 || b[0] == 0) 1660 return 0; 1661 1662 if (a[0] != b[0]) 1663 return 0; 1664 l = a[0]; 1665 if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen) 1666 return 0; 1667 if (bcmp(a + 1, b + 1, l) != 0) 1668 return 0; 1669 1670 a += 1 + l; 1671 b += 1 + l; 1672 } 1673 1674 if (a - a0 == alen && b - b0 == blen) 1675 return 1; 1676 else 1677 return 0; 1678 } 1679 1680 /* 1681 * calculate the number of addresses to be returned in the node info reply. 1682 */ 1683 static int 1684 ni6_addrs(struct icmp6_nodeinfo *ni6, struct mbuf *m, struct ifnet **ifpp, 1685 struct in6_addr *subj) 1686 { 1687 struct ifnet *ifp; 1688 struct in6_ifaddr *ifa6; 1689 struct ifaddr *ifa; 1690 int addrs = 0, addrsofif, iffound = 0; 1691 int niflags = ni6->ni_flags; 1692 1693 NET_EPOCH_ASSERT(); 1694 1695 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) { 1696 switch (ni6->ni_code) { 1697 case ICMP6_NI_SUBJ_IPV6: 1698 if (subj == NULL) /* must be impossible... */ 1699 return (0); 1700 break; 1701 default: 1702 /* 1703 * XXX: we only support IPv6 subject address for 1704 * this Qtype. 1705 */ 1706 return (0); 1707 } 1708 } 1709 1710 CK_STAILQ_FOREACH(ifp, &V_ifnet, if_link) { 1711 addrsofif = 0; 1712 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 1713 if (ifa->ifa_addr->sa_family != AF_INET6) 1714 continue; 1715 ifa6 = (struct in6_ifaddr *)ifa; 1716 1717 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 && 1718 IN6_ARE_ADDR_EQUAL(subj, &ifa6->ia_addr.sin6_addr)) 1719 iffound = 1; 1720 1721 /* 1722 * IPv4-mapped addresses can only be returned by a 1723 * Node Information proxy, since they represent 1724 * addresses of IPv4-only nodes, which perforce do 1725 * not implement this protocol. 1726 * [icmp-name-lookups-07, Section 5.4] 1727 * So we don't support NI_NODEADDR_FLAG_COMPAT in 1728 * this function at this moment. 1729 */ 1730 1731 /* What do we have to do about ::1? */ 1732 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { 1733 case IPV6_ADDR_SCOPE_LINKLOCAL: 1734 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) 1735 continue; 1736 break; 1737 case IPV6_ADDR_SCOPE_SITELOCAL: 1738 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) 1739 continue; 1740 break; 1741 case IPV6_ADDR_SCOPE_GLOBAL: 1742 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) 1743 continue; 1744 break; 1745 default: 1746 continue; 1747 } 1748 1749 /* 1750 * check if anycast is okay. 1751 * XXX: just experimental. not in the spec. 1752 */ 1753 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && 1754 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) 1755 continue; /* we need only unicast addresses */ 1756 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && 1757 (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) { 1758 continue; 1759 } 1760 addrsofif++; /* count the address */ 1761 } 1762 if (iffound) { 1763 *ifpp = ifp; 1764 return (addrsofif); 1765 } 1766 1767 addrs += addrsofif; 1768 } 1769 1770 return (addrs); 1771 } 1772 1773 static int 1774 ni6_store_addrs(struct icmp6_nodeinfo *ni6, struct icmp6_nodeinfo *nni6, 1775 struct ifnet *ifp0, int resid) 1776 { 1777 struct ifnet *ifp; 1778 struct in6_ifaddr *ifa6; 1779 struct ifaddr *ifa; 1780 struct ifnet *ifp_dep = NULL; 1781 int copied = 0, allow_deprecated = 0; 1782 u_char *cp = (u_char *)(nni6 + 1); 1783 int niflags = ni6->ni_flags; 1784 u_int32_t ltime; 1785 1786 NET_EPOCH_ASSERT(); 1787 1788 if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL)) 1789 return (0); /* needless to copy */ 1790 1791 ifp = ifp0 ? ifp0 : CK_STAILQ_FIRST(&V_ifnet); 1792 again: 1793 1794 for (; ifp; ifp = CK_STAILQ_NEXT(ifp, if_link)) { 1795 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 1796 if (ifa->ifa_addr->sa_family != AF_INET6) 1797 continue; 1798 ifa6 = (struct in6_ifaddr *)ifa; 1799 1800 if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 && 1801 allow_deprecated == 0) { 1802 /* 1803 * prefererred address should be put before 1804 * deprecated addresses. 1805 */ 1806 1807 /* record the interface for later search */ 1808 if (ifp_dep == NULL) 1809 ifp_dep = ifp; 1810 1811 continue; 1812 } else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 && 1813 allow_deprecated != 0) 1814 continue; /* we now collect deprecated addrs */ 1815 1816 /* What do we have to do about ::1? */ 1817 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { 1818 case IPV6_ADDR_SCOPE_LINKLOCAL: 1819 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) 1820 continue; 1821 break; 1822 case IPV6_ADDR_SCOPE_SITELOCAL: 1823 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) 1824 continue; 1825 break; 1826 case IPV6_ADDR_SCOPE_GLOBAL: 1827 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) 1828 continue; 1829 break; 1830 default: 1831 continue; 1832 } 1833 1834 /* 1835 * check if anycast is okay. 1836 * XXX: just experimental. not in the spec. 1837 */ 1838 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && 1839 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) 1840 continue; 1841 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && 1842 (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) { 1843 continue; 1844 } 1845 1846 /* now we can copy the address */ 1847 if (resid < sizeof(struct in6_addr) + 1848 sizeof(u_int32_t)) { 1849 /* 1850 * We give up much more copy. 1851 * Set the truncate flag and return. 1852 */ 1853 nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE; 1854 return (copied); 1855 } 1856 1857 /* 1858 * Set the TTL of the address. 1859 * The TTL value should be one of the following 1860 * according to the specification: 1861 * 1862 * 1. The remaining lifetime of a DHCP lease on the 1863 * address, or 1864 * 2. The remaining Valid Lifetime of a prefix from 1865 * which the address was derived through Stateless 1866 * Autoconfiguration. 1867 * 1868 * Note that we currently do not support stateful 1869 * address configuration by DHCPv6, so the former 1870 * case can't happen. 1871 */ 1872 if (ifa6->ia6_lifetime.ia6t_expire == 0) 1873 ltime = ND6_INFINITE_LIFETIME; 1874 else { 1875 if (ifa6->ia6_lifetime.ia6t_expire > 1876 time_uptime) 1877 ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_uptime); 1878 else 1879 ltime = 0; 1880 } 1881 1882 bcopy(<ime, cp, sizeof(u_int32_t)); 1883 cp += sizeof(u_int32_t); 1884 1885 /* copy the address itself */ 1886 bcopy(&ifa6->ia_addr.sin6_addr, cp, 1887 sizeof(struct in6_addr)); 1888 in6_clearscope((struct in6_addr *)cp); /* XXX */ 1889 cp += sizeof(struct in6_addr); 1890 1891 resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t)); 1892 copied += (sizeof(struct in6_addr) + sizeof(u_int32_t)); 1893 } 1894 if (ifp0) /* we need search only on the specified IF */ 1895 break; 1896 } 1897 1898 if (allow_deprecated == 0 && ifp_dep != NULL) { 1899 ifp = ifp_dep; 1900 allow_deprecated = 1; 1901 1902 goto again; 1903 } 1904 1905 return (copied); 1906 } 1907 1908 static bool 1909 icmp6_rip6_match(const struct inpcb *inp, void *v) 1910 { 1911 struct ip6_hdr *ip6 = v; 1912 1913 if ((inp->inp_vflag & INP_IPV6) == 0) 1914 return (false); 1915 if (inp->inp_ip_p != IPPROTO_ICMPV6) 1916 return (false); 1917 if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr) && 1918 !IN6_ARE_ADDR_EQUAL(&inp->in6p_laddr, &ip6->ip6_dst)) 1919 return (false); 1920 if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr) && 1921 !IN6_ARE_ADDR_EQUAL(&inp->in6p_faddr, &ip6->ip6_src)) 1922 return (false); 1923 return (true); 1924 } 1925 1926 /* 1927 * XXX almost dup'ed code with rip6_input. 1928 */ 1929 static int 1930 icmp6_rip6_input(struct mbuf **mp, int off) 1931 { 1932 struct mbuf *n, *m = *mp; 1933 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1934 struct inpcb_iterator inpi = INP_ITERATOR(&V_ripcbinfo, 1935 INPLOOKUP_RLOCKPCB, icmp6_rip6_match, ip6); 1936 struct inpcb *inp; 1937 struct sockaddr_in6 fromsa; 1938 struct icmp6_hdr *icmp6; 1939 struct mbuf *opts = NULL; 1940 int delivered = 0, fib; 1941 1942 /* This is assumed to be safe; icmp6_input() does a pullup. */ 1943 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off); 1944 1945 /* 1946 * XXX: the address may have embedded scope zone ID, which should be 1947 * hidden from applications. 1948 */ 1949 bzero(&fromsa, sizeof(fromsa)); 1950 fromsa.sin6_family = AF_INET6; 1951 fromsa.sin6_len = sizeof(struct sockaddr_in6); 1952 fromsa.sin6_addr = ip6->ip6_src; 1953 if (sa6_recoverscope(&fromsa)) { 1954 m_freem(m); 1955 *mp = NULL; 1956 return (IPPROTO_DONE); 1957 } 1958 1959 fib = M_GETFIB(m); 1960 1961 while ((inp = inp_next(&inpi)) != NULL) { 1962 if (V_rip_bind_all_fibs == 0 && fib != inp->inp_inc.inc_fibnum) 1963 /* 1964 * Sockets bound to a specific FIB can only receive 1965 * packets from that FIB. 1966 */ 1967 continue; 1968 if (ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type, 1969 inp->in6p_icmp6filt)) 1970 continue; 1971 /* 1972 * Recent network drivers tend to allocate a single 1973 * mbuf cluster, rather than to make a couple of 1974 * mbufs without clusters. Also, since the IPv6 code 1975 * path tries to avoid m_pullup(), it is highly 1976 * probable that we still have an mbuf cluster here 1977 * even though the necessary length can be stored in an 1978 * mbuf's internal buffer. 1979 * Meanwhile, the default size of the receive socket 1980 * buffer for raw sockets is not so large. This means 1981 * the possibility of packet loss is relatively higher 1982 * than before. To avoid this scenario, we copy the 1983 * received data to a separate mbuf that does not use 1984 * a cluster, if possible. 1985 * XXX: it is better to copy the data after stripping 1986 * intermediate headers. 1987 */ 1988 if ((m->m_flags & M_EXT) && m->m_next == NULL && 1989 m->m_len <= MHLEN) { 1990 n = m_get(M_NOWAIT, m->m_type); 1991 if (n != NULL) { 1992 if (m_dup_pkthdr(n, m, M_NOWAIT)) { 1993 bcopy(m->m_data, n->m_data, m->m_len); 1994 n->m_len = m->m_len; 1995 } else { 1996 m_free(n); 1997 n = NULL; 1998 } 1999 } 2000 } else 2001 n = m_copym(m, 0, M_COPYALL, M_NOWAIT); 2002 if (n == NULL) 2003 continue; 2004 if (inp->inp_flags & INP_CONTROLOPTS) 2005 ip6_savecontrol(inp, n, &opts); 2006 /* strip intermediate headers */ 2007 m_adj(n, off); 2008 SOCKBUF_LOCK(&inp->inp_socket->so_rcv); 2009 if (sbappendaddr_locked(&inp->inp_socket->so_rcv, 2010 (struct sockaddr *)&fromsa, n, opts) == 0) { 2011 soroverflow_locked(inp->inp_socket); 2012 m_freem(n); 2013 if (opts) 2014 m_freem(opts); 2015 } else { 2016 sorwakeup_locked(inp->inp_socket); 2017 delivered++; 2018 } 2019 opts = NULL; 2020 } 2021 m_freem(m); 2022 *mp = NULL; 2023 if (delivered == 0) 2024 IP6STAT_DEC(ip6s_delivered); 2025 return (IPPROTO_DONE); 2026 } 2027 2028 /* 2029 * Reflect the ip6 packet back to the source. 2030 * OFF points to the icmp6 header, counted from the top of the mbuf. 2031 */ 2032 static void 2033 icmp6_reflect(struct mbuf *m, size_t off) 2034 { 2035 struct in6_addr src6, *srcp; 2036 struct ip6_hdr *ip6; 2037 struct icmp6_hdr *icmp6; 2038 struct in6_ifaddr *ia = NULL; 2039 struct ifnet *outif = NULL; 2040 int plen; 2041 int type, code, hlim; 2042 2043 /* too short to reflect */ 2044 if (off < sizeof(struct ip6_hdr)) { 2045 nd6log((LOG_DEBUG, 2046 "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n", 2047 (u_long)off, (u_long)sizeof(struct ip6_hdr), 2048 __FILE__, __LINE__)); 2049 goto bad; 2050 } 2051 2052 /* 2053 * If there are extra headers between IPv6 and ICMPv6, strip 2054 * off that header first. 2055 */ 2056 #ifdef DIAGNOSTIC 2057 if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN) 2058 panic("assumption failed in icmp6_reflect"); 2059 #endif 2060 if (off > sizeof(struct ip6_hdr)) { 2061 size_t l; 2062 struct ip6_hdr nip6; 2063 2064 l = off - sizeof(struct ip6_hdr); 2065 m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6); 2066 m_adj(m, l); 2067 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 2068 if (m->m_len < l) { 2069 if ((m = m_pullup(m, l)) == NULL) 2070 return; 2071 } 2072 bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6)); 2073 } else /* off == sizeof(struct ip6_hdr) */ { 2074 size_t l; 2075 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 2076 if (m->m_len < l) { 2077 if ((m = m_pullup(m, l)) == NULL) 2078 return; 2079 } 2080 } 2081 plen = m->m_pkthdr.len - sizeof(struct ip6_hdr); 2082 ip6 = mtod(m, struct ip6_hdr *); 2083 ip6->ip6_nxt = IPPROTO_ICMPV6; 2084 icmp6 = (struct icmp6_hdr *)(ip6 + 1); 2085 type = icmp6->icmp6_type; /* keep type for statistics */ 2086 code = icmp6->icmp6_code; /* ditto. */ 2087 hlim = 0; 2088 srcp = NULL; 2089 2090 /* 2091 * If the incoming packet was addressed directly to us (i.e. unicast), 2092 * use dst as the src for the reply. 2093 * The IN6_IFF_NOTREADY case should be VERY rare, but is possible 2094 * (for example) when we encounter an error while forwarding procedure 2095 * destined to a duplicated address of ours. 2096 */ 2097 if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 2098 ia = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */, false); 2099 if (ia != NULL && !(ia->ia6_flags & 2100 (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) { 2101 src6 = ia->ia_addr.sin6_addr; 2102 srcp = &src6; 2103 2104 if (m->m_pkthdr.rcvif != NULL) { 2105 /* XXX: This may not be the outgoing interface */ 2106 hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim; 2107 } else 2108 hlim = V_ip6_defhlim; 2109 } 2110 } 2111 2112 if (srcp == NULL) { 2113 int error; 2114 struct in6_addr dst6; 2115 uint32_t scopeid; 2116 2117 /* 2118 * This case matches to multicasts, our anycast, or unicasts 2119 * that we do not own. Select a source address based on the 2120 * source address of the erroneous packet. 2121 */ 2122 in6_splitscope(&ip6->ip6_src, &dst6, &scopeid); 2123 error = in6_selectsrc_addr(M_GETFIB(m), &dst6, 2124 scopeid, NULL, &src6, &hlim); 2125 2126 if (error) { 2127 char ip6buf[INET6_ADDRSTRLEN]; 2128 nd6log((LOG_DEBUG, 2129 "icmp6_reflect: source can't be determined: " 2130 "dst=%s, error=%d\n", 2131 ip6_sprintf(ip6buf, &ip6->ip6_dst), error)); 2132 goto bad; 2133 } 2134 srcp = &src6; 2135 } 2136 /* 2137 * ip6_input() drops a packet if its src is multicast. 2138 * So, the src is never multicast. 2139 */ 2140 ip6->ip6_dst = ip6->ip6_src; 2141 ip6->ip6_src = *srcp; 2142 ip6->ip6_flow = 0; 2143 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2144 ip6->ip6_vfc |= IPV6_VERSION; 2145 ip6->ip6_nxt = IPPROTO_ICMPV6; 2146 ip6->ip6_hlim = hlim; 2147 2148 icmp6->icmp6_cksum = 0; 2149 icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2150 sizeof(struct ip6_hdr), plen); 2151 2152 /* 2153 * XXX option handling 2154 */ 2155 2156 m->m_flags &= ~(M_BCAST|M_MCAST); 2157 m->m_pkthdr.rcvif = NULL; 2158 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2159 if (outif) 2160 icmp6_ifoutstat_inc(outif, type, code); 2161 2162 return; 2163 2164 bad: 2165 m_freem(m); 2166 return; 2167 } 2168 2169 static const char * 2170 icmp6_redirect_diag(struct in6_addr *src6, struct in6_addr *dst6, 2171 struct in6_addr *tgt6) 2172 { 2173 static char buf[1024]; 2174 char ip6bufs[INET6_ADDRSTRLEN]; 2175 char ip6bufd[INET6_ADDRSTRLEN]; 2176 char ip6buft[INET6_ADDRSTRLEN]; 2177 snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)", 2178 ip6_sprintf(ip6bufs, src6), ip6_sprintf(ip6bufd, dst6), 2179 ip6_sprintf(ip6buft, tgt6)); 2180 return buf; 2181 } 2182 2183 void 2184 icmp6_redirect_input(struct mbuf *m, int off) 2185 { 2186 struct ifnet *ifp; 2187 struct ip6_hdr *ip6; 2188 struct nd_redirect *nd_rd; 2189 struct in6_addr src6, redtgt6, reddst6; 2190 union nd_opts ndopts; 2191 char ip6buf[INET6_ADDRSTRLEN]; 2192 char *lladdr; 2193 int icmp6len, is_onlink, is_router, lladdrlen; 2194 2195 M_ASSERTPKTHDR(m); 2196 KASSERT(m->m_pkthdr.rcvif != NULL, ("%s: no rcvif", __func__)); 2197 2198 /* XXX if we are router, we don't update route by icmp6 redirect */ 2199 if (V_ip6_forwarding) 2200 goto freeit; 2201 if (!V_icmp6_rediraccept) 2202 goto freeit; 2203 2204 /* RFC 6980: Nodes MUST silently ignore fragments */ 2205 if(m->m_flags & M_FRAGMENTED) 2206 goto freeit; 2207 2208 ip6 = mtod(m, struct ip6_hdr *); 2209 icmp6len = ntohs(ip6->ip6_plen); 2210 if (m->m_len < off + icmp6len) { 2211 m = m_pullup(m, off + icmp6len); 2212 if (m == NULL) { 2213 IP6STAT_INC(ip6s_exthdrtoolong); 2214 return; 2215 } 2216 } 2217 ip6 = mtod(m, struct ip6_hdr *); 2218 nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off); 2219 2220 ifp = m->m_pkthdr.rcvif; 2221 redtgt6 = nd_rd->nd_rd_target; 2222 reddst6 = nd_rd->nd_rd_dst; 2223 2224 if (in6_setscope(&redtgt6, ifp, NULL) || 2225 in6_setscope(&reddst6, ifp, NULL)) { 2226 goto freeit; 2227 } 2228 2229 /* validation */ 2230 src6 = ip6->ip6_src; 2231 if (!IN6_IS_ADDR_LINKLOCAL(&src6)) { 2232 nd6log((LOG_ERR, 2233 "ICMP6 redirect sent from %s rejected; " 2234 "must be from linklocal\n", 2235 ip6_sprintf(ip6buf, &src6))); 2236 goto bad; 2237 } 2238 if (__predict_false(ip6->ip6_hlim != 255)) { 2239 ICMP6STAT_INC(icp6s_invlhlim); 2240 nd6log((LOG_ERR, 2241 "ICMP6 redirect sent from %s rejected; " 2242 "hlim=%d (must be 255)\n", 2243 ip6_sprintf(ip6buf, &src6), ip6->ip6_hlim)); 2244 goto bad; 2245 } 2246 { 2247 /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */ 2248 struct nhop_object *nh; 2249 struct in6_addr kdst; 2250 uint32_t scopeid; 2251 2252 in6_splitscope(&reddst6, &kdst, &scopeid); 2253 NET_EPOCH_ASSERT(); 2254 nh = fib6_lookup(ifp->if_fib, &kdst, scopeid, 0, 0); 2255 if (nh != NULL) { 2256 struct in6_addr nh_addr; 2257 nh_addr = ifatoia6(nh->nh_ifa)->ia_addr.sin6_addr; 2258 if ((nh->nh_flags & NHF_GATEWAY) == 0) { 2259 nd6log((LOG_ERR, 2260 "ICMP6 redirect rejected; no route " 2261 "with inet6 gateway found for redirect dst: %s\n", 2262 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2263 goto bad; 2264 } 2265 2266 /* 2267 * Embed scope zone id into next hop address. 2268 */ 2269 nh_addr = nh->gw6_sa.sin6_addr; 2270 2271 if (IN6_ARE_ADDR_EQUAL(&src6, &nh_addr) == 0) { 2272 nd6log((LOG_ERR, 2273 "ICMP6 redirect rejected; " 2274 "not equal to gw-for-src=%s (must be same): " 2275 "%s\n", 2276 ip6_sprintf(ip6buf, &nh_addr), 2277 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2278 goto bad; 2279 } 2280 } else { 2281 nd6log((LOG_ERR, 2282 "ICMP6 redirect rejected; " 2283 "no route found for redirect dst: %s\n", 2284 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2285 goto bad; 2286 } 2287 } 2288 if (IN6_IS_ADDR_MULTICAST(&reddst6)) { 2289 nd6log((LOG_ERR, 2290 "ICMP6 redirect rejected; " 2291 "redirect dst must be unicast: %s\n", 2292 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2293 goto bad; 2294 } 2295 2296 is_router = is_onlink = 0; 2297 if (IN6_IS_ADDR_LINKLOCAL(&redtgt6)) 2298 is_router = 1; /* router case */ 2299 if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0) 2300 is_onlink = 1; /* on-link destination case */ 2301 if (!is_router && !is_onlink) { 2302 nd6log((LOG_ERR, 2303 "ICMP6 redirect rejected; " 2304 "neither router case nor onlink case: %s\n", 2305 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2306 goto bad; 2307 } 2308 2309 icmp6len -= sizeof(*nd_rd); 2310 nd6_option_init(nd_rd + 1, icmp6len, &ndopts); 2311 if (nd6_options(&ndopts) < 0) { 2312 nd6log((LOG_INFO, "%s: invalid ND option, rejected: %s\n", 2313 __func__, icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2314 /* nd6_options have incremented stats */ 2315 goto freeit; 2316 } 2317 2318 lladdr = NULL; 2319 lladdrlen = 0; 2320 if (ndopts.nd_opts_tgt_lladdr) { 2321 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 2322 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 2323 } 2324 2325 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 2326 nd6log((LOG_INFO, "%s: lladdrlen mismatch for %s " 2327 "(if %d, icmp6 packet %d): %s\n", 2328 __func__, ip6_sprintf(ip6buf, &redtgt6), 2329 ifp->if_addrlen, lladdrlen - 2, 2330 icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 2331 goto bad; 2332 } 2333 2334 /* Validation passed. */ 2335 2336 /* RFC 2461 8.3 */ 2337 nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT, 2338 is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER); 2339 2340 /* 2341 * Install a gateway route in the better-router case or an interface 2342 * route in the on-link-destination case. 2343 */ 2344 { 2345 struct sockaddr_in6 sdst; 2346 struct sockaddr_in6 sgw; 2347 struct sockaddr_in6 ssrc; 2348 struct sockaddr *gw; 2349 int rt_flags; 2350 u_int fibnum; 2351 2352 bzero(&sdst, sizeof(sdst)); 2353 bzero(&ssrc, sizeof(ssrc)); 2354 sdst.sin6_family = ssrc.sin6_family = AF_INET6; 2355 sdst.sin6_len = ssrc.sin6_len = sizeof(struct sockaddr_in6); 2356 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr)); 2357 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr)); 2358 rt_flags = 0; 2359 if (is_router) { 2360 bzero(&sgw, sizeof(sgw)); 2361 sgw.sin6_family = AF_INET6; 2362 sgw.sin6_len = sizeof(struct sockaddr_in6); 2363 bcopy(&redtgt6, &sgw.sin6_addr, 2364 sizeof(struct in6_addr)); 2365 gw = (struct sockaddr *)&sgw; 2366 rt_flags |= RTF_GATEWAY; 2367 } else 2368 gw = ifp->if_addr->ifa_addr; 2369 for (fibnum = 0; fibnum < rt_numfibs; fibnum++) 2370 rib_add_redirect(fibnum, (struct sockaddr *)&sdst, gw, 2371 (struct sockaddr *)&ssrc, ifp, rt_flags, 2372 V_icmp6_redirtimeout); 2373 } 2374 2375 freeit: 2376 m_freem(m); 2377 return; 2378 2379 bad: 2380 ICMP6STAT_INC(icp6s_badredirect); 2381 m_freem(m); 2382 } 2383 2384 void 2385 icmp6_redirect_output(struct mbuf *m0, struct nhop_object *nh) 2386 { 2387 struct ifnet *ifp; /* my outgoing interface */ 2388 struct in6_addr *ifp_ll6; 2389 struct in6_addr *router_ll6; 2390 struct ip6_hdr *sip6; /* m0 as struct ip6_hdr */ 2391 struct mbuf *m = NULL; /* newly allocated one */ 2392 struct m_tag *mtag; 2393 struct ip6_hdr *ip6; /* m as struct ip6_hdr */ 2394 struct nd_redirect *nd_rd; 2395 struct llentry *ln = NULL; 2396 size_t maxlen; 2397 u_char *p; 2398 struct ifnet *outif = NULL; 2399 struct sockaddr_in6 src_sa; 2400 2401 icmp6_errcount(ND_REDIRECT, 0); 2402 2403 /* if we are not router, we don't send icmp6 redirect */ 2404 if (!V_ip6_forwarding) 2405 goto fail; 2406 2407 /* sanity check */ 2408 if (!m0 || !nh || !(NH_IS_VALID(nh)) || !(ifp = nh->nh_ifp)) 2409 goto fail; 2410 2411 /* 2412 * Address check: 2413 * the source address must identify a neighbor, and 2414 * the destination address must not be a multicast address 2415 * [RFC 2461, sec 8.2] 2416 */ 2417 sip6 = mtod(m0, struct ip6_hdr *); 2418 bzero(&src_sa, sizeof(src_sa)); 2419 src_sa.sin6_family = AF_INET6; 2420 src_sa.sin6_len = sizeof(src_sa); 2421 src_sa.sin6_addr = sip6->ip6_src; 2422 if (nd6_is_addr_neighbor(&src_sa, ifp) == 0) 2423 goto fail; 2424 if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst)) 2425 goto fail; /* what should we do here? */ 2426 2427 /* rate limit */ 2428 if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0)) 2429 goto fail; 2430 2431 /* 2432 * Since we are going to append up to 1280 bytes (= IPV6_MMTU), 2433 * we almost always ask for an mbuf cluster for simplicity. 2434 * (MHLEN < IPV6_MMTU is almost always true) 2435 */ 2436 #if IPV6_MMTU >= MCLBYTES 2437 # error assumption failed about IPV6_MMTU and MCLBYTES 2438 #endif 2439 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 2440 if (m == NULL) 2441 goto fail; 2442 M_SETFIB(m, M_GETFIB(m0)); 2443 maxlen = M_TRAILINGSPACE(m); 2444 maxlen = min(IPV6_MMTU, maxlen); 2445 /* just for safety */ 2446 if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) + 2447 ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) { 2448 goto fail; 2449 } 2450 2451 { 2452 /* get ip6 linklocal address for ifp(my outgoing interface). */ 2453 struct in6_ifaddr *ia; 2454 if ((ia = in6ifa_ifpforlinklocal(ifp, 2455 IN6_IFF_NOTREADY| 2456 IN6_IFF_ANYCAST)) == NULL) 2457 goto fail; 2458 ifp_ll6 = &ia->ia_addr.sin6_addr; 2459 /* XXXRW: reference released prematurely. */ 2460 ifa_free(&ia->ia_ifa); 2461 } 2462 2463 /* get ip6 linklocal address for the router. */ 2464 if (nh->nh_flags & NHF_GATEWAY) { 2465 struct sockaddr_in6 *sin6; 2466 sin6 = &nh->gw6_sa; 2467 router_ll6 = &sin6->sin6_addr; 2468 if (!IN6_IS_ADDR_LINKLOCAL(router_ll6)) 2469 router_ll6 = (struct in6_addr *)NULL; 2470 } else 2471 router_ll6 = (struct in6_addr *)NULL; 2472 2473 /* ip6 */ 2474 ip6 = mtod(m, struct ip6_hdr *); 2475 ip6->ip6_flow = 0; 2476 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2477 ip6->ip6_vfc |= IPV6_VERSION; 2478 /* ip6->ip6_plen will be set later */ 2479 ip6->ip6_nxt = IPPROTO_ICMPV6; 2480 ip6->ip6_hlim = 255; 2481 /* ip6->ip6_src must be linklocal addr for my outgoing if. */ 2482 bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr)); 2483 bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr)); 2484 2485 /* ND Redirect */ 2486 nd_rd = (struct nd_redirect *)(ip6 + 1); 2487 nd_rd->nd_rd_type = ND_REDIRECT; 2488 nd_rd->nd_rd_code = 0; 2489 nd_rd->nd_rd_reserved = 0; 2490 if (nh->nh_flags & NHF_GATEWAY) { 2491 /* 2492 * nd_rd->nd_rd_target must be a link-local address in 2493 * better router cases. 2494 */ 2495 if (!router_ll6) 2496 goto fail; 2497 bcopy(router_ll6, &nd_rd->nd_rd_target, 2498 sizeof(nd_rd->nd_rd_target)); 2499 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2500 sizeof(nd_rd->nd_rd_dst)); 2501 } else { 2502 /* make sure redtgt == reddst */ 2503 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target, 2504 sizeof(nd_rd->nd_rd_target)); 2505 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2506 sizeof(nd_rd->nd_rd_dst)); 2507 } 2508 2509 p = (u_char *)(nd_rd + 1); 2510 2511 if (!router_ll6) 2512 goto nolladdropt; 2513 2514 { 2515 /* target lladdr option */ 2516 int len; 2517 struct nd_opt_hdr *nd_opt; 2518 char *lladdr; 2519 2520 ln = nd6_lookup(router_ll6, LLE_SF(AF_INET6, 0), ifp); 2521 if (ln == NULL) 2522 goto nolladdropt; 2523 2524 len = sizeof(*nd_opt) + ifp->if_addrlen; 2525 len = (len + 7) & ~7; /* round by 8 */ 2526 /* safety check */ 2527 if (len + (p - (u_char *)ip6) > maxlen) 2528 goto nolladdropt; 2529 2530 if (ln->la_flags & LLE_VALID) { 2531 nd_opt = (struct nd_opt_hdr *)p; 2532 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 2533 nd_opt->nd_opt_len = len >> 3; 2534 lladdr = (char *)(nd_opt + 1); 2535 bcopy(ln->ll_addr, lladdr, ifp->if_addrlen); 2536 p += len; 2537 } 2538 } 2539 nolladdropt: 2540 if (ln != NULL) 2541 LLE_RUNLOCK(ln); 2542 2543 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2544 2545 /* just to be safe */ 2546 #ifdef M_DECRYPTED /*not openbsd*/ 2547 if (m0->m_flags & M_DECRYPTED) 2548 goto noredhdropt; 2549 #endif 2550 if (p - (u_char *)ip6 > maxlen) 2551 goto noredhdropt; 2552 2553 { 2554 /* redirected header option */ 2555 int len; 2556 struct nd_opt_rd_hdr *nd_opt_rh; 2557 2558 /* 2559 * compute the maximum size for icmp6 redirect header option. 2560 * XXX room for auth header? 2561 */ 2562 len = maxlen - (p - (u_char *)ip6); 2563 len &= ~7; 2564 2565 /* This is just for simplicity. */ 2566 if (m0->m_pkthdr.len != m0->m_len) { 2567 if (m0->m_next) { 2568 m_freem(m0->m_next); 2569 m0->m_next = NULL; 2570 } 2571 m0->m_pkthdr.len = m0->m_len; 2572 } 2573 2574 /* 2575 * Redirected header option spec (RFC2461 4.6.3) talks nothing 2576 * about padding/truncate rule for the original IP packet. 2577 * From the discussion on IPv6imp in Feb 1999, 2578 * the consensus was: 2579 * - "attach as much as possible" is the goal 2580 * - pad if not aligned (original size can be guessed by 2581 * original ip6 header) 2582 * Following code adds the padding if it is simple enough, 2583 * and truncates if not. 2584 */ 2585 if (m0->m_next || m0->m_pkthdr.len != m0->m_len) 2586 panic("assumption failed in %s:%d", __FILE__, 2587 __LINE__); 2588 2589 if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) { 2590 /* not enough room, truncate */ 2591 m0->m_pkthdr.len = m0->m_len = len - 2592 sizeof(*nd_opt_rh); 2593 } else { 2594 /* enough room, pad or truncate */ 2595 size_t extra; 2596 2597 extra = m0->m_pkthdr.len % 8; 2598 if (extra) { 2599 /* pad if easy enough, truncate if not */ 2600 if (8 - extra <= M_TRAILINGSPACE(m0)) { 2601 /* pad */ 2602 m0->m_len += (8 - extra); 2603 m0->m_pkthdr.len += (8 - extra); 2604 } else { 2605 /* truncate */ 2606 m0->m_pkthdr.len -= extra; 2607 m0->m_len -= extra; 2608 } 2609 } 2610 len = m0->m_pkthdr.len + sizeof(*nd_opt_rh); 2611 m0->m_pkthdr.len = m0->m_len = len - 2612 sizeof(*nd_opt_rh); 2613 } 2614 2615 nd_opt_rh = (struct nd_opt_rd_hdr *)p; 2616 bzero(nd_opt_rh, sizeof(*nd_opt_rh)); 2617 nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER; 2618 nd_opt_rh->nd_opt_rh_len = len >> 3; 2619 p += sizeof(*nd_opt_rh); 2620 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2621 2622 /* connect m0 to m */ 2623 m_tag_delete_chain(m0, NULL); 2624 m0->m_flags &= ~M_PKTHDR; 2625 m->m_next = m0; 2626 m->m_pkthdr.len = m->m_len + m0->m_len; 2627 m0 = NULL; 2628 } 2629 noredhdropt:; 2630 if (m0) { 2631 m_freem(m0); 2632 m0 = NULL; 2633 } 2634 2635 /* XXX: clear embedded link IDs in the inner header */ 2636 in6_clearscope(&sip6->ip6_src); 2637 in6_clearscope(&sip6->ip6_dst); 2638 in6_clearscope(&nd_rd->nd_rd_target); 2639 in6_clearscope(&nd_rd->nd_rd_dst); 2640 2641 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr)); 2642 2643 nd_rd->nd_rd_cksum = 0; 2644 nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2645 sizeof(*ip6), ntohs(ip6->ip6_plen)); 2646 2647 if (send_sendso_input_hook != NULL) { 2648 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, sizeof(unsigned short), 2649 M_NOWAIT); 2650 if (mtag == NULL) 2651 goto fail; 2652 *(unsigned short *)(mtag + 1) = nd_rd->nd_rd_type; 2653 m_tag_prepend(m, mtag); 2654 } 2655 2656 /* send the packet to outside... */ 2657 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); 2658 if (outif) { 2659 icmp6_ifstat_inc(outif, ifs6_out_msg); 2660 icmp6_ifstat_inc(outif, ifs6_out_redirect); 2661 } 2662 ICMP6STAT_INC2(icp6s_outhist, ND_REDIRECT); 2663 2664 return; 2665 2666 fail: 2667 if (m) 2668 m_freem(m); 2669 if (m0) 2670 m_freem(m0); 2671 } 2672 2673 /* 2674 * ICMPv6 socket option processing. 2675 */ 2676 int 2677 icmp6_ctloutput(struct socket *so, struct sockopt *sopt) 2678 { 2679 int error = 0; 2680 int optlen; 2681 struct inpcb *inp = sotoinpcb(so); 2682 int level, op, optname; 2683 2684 if (sopt) { 2685 level = sopt->sopt_level; 2686 op = sopt->sopt_dir; 2687 optname = sopt->sopt_name; 2688 optlen = sopt->sopt_valsize; 2689 } else 2690 level = op = optname = optlen = 0; 2691 2692 if (level != IPPROTO_ICMPV6) { 2693 return EINVAL; 2694 } 2695 2696 switch (op) { 2697 case SOPT_SET: 2698 switch (optname) { 2699 case ICMP6_FILTER: 2700 { 2701 struct icmp6_filter ic6f; 2702 2703 if (optlen != sizeof(ic6f)) { 2704 error = EMSGSIZE; 2705 break; 2706 } 2707 error = sooptcopyin(sopt, &ic6f, optlen, optlen); 2708 if (error == 0) { 2709 INP_WLOCK(inp); 2710 *inp->in6p_icmp6filt = ic6f; 2711 INP_WUNLOCK(inp); 2712 } 2713 break; 2714 } 2715 2716 default: 2717 error = ENOPROTOOPT; 2718 break; 2719 } 2720 break; 2721 2722 case SOPT_GET: 2723 switch (optname) { 2724 case ICMP6_FILTER: 2725 { 2726 struct icmp6_filter ic6f; 2727 2728 INP_RLOCK(inp); 2729 ic6f = *inp->in6p_icmp6filt; 2730 INP_RUNLOCK(inp); 2731 error = sooptcopyout(sopt, &ic6f, sizeof(ic6f)); 2732 break; 2733 } 2734 2735 default: 2736 error = ENOPROTOOPT; 2737 break; 2738 } 2739 break; 2740 } 2741 2742 return (error); 2743 } 2744 2745 static int sysctl_icmp6lim_and_jitter(SYSCTL_HANDLER_ARGS); 2746 VNET_DEFINE_STATIC(u_int, icmp6errppslim) = 100; 2747 #define V_icmp6errppslim VNET(icmp6errppslim) 2748 SYSCTL_PROC(_net_inet6_icmp6, ICMPV6CTL_ERRPPSLIMIT, errppslimit, 2749 CTLTYPE_UINT | CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(icmp6errppslim), 0, 2750 &sysctl_icmp6lim_and_jitter, "IU", 2751 "Maximum number of ICMPv6 error/reply messages per second"); 2752 2753 typedef enum { 2754 RATELIM_PARAM_PROB = 0, 2755 RATELIM_TOO_BIG, 2756 RATELIM_UNREACH, 2757 RATELIM_TEXCEED, 2758 RATELIM_REDIR, 2759 RATELIM_REPLY, 2760 RATELIM_OTHER, 2761 RATELIM_MAX 2762 } ratelim_which; 2763 2764 static const char *icmp6_rate_descrs[RATELIM_MAX] = { 2765 [RATELIM_PARAM_PROB] = "bad IPv6 header", 2766 [RATELIM_TOO_BIG] = "packet too big", 2767 [RATELIM_UNREACH] = "destination unreachable", 2768 [RATELIM_TEXCEED] = "time exceeded", 2769 [RATELIM_REPLY] = "echo reply", 2770 [RATELIM_REDIR] = "neighbor discovery redirect", 2771 [RATELIM_OTHER] = "(other)", 2772 }; 2773 2774 VNET_DEFINE_STATIC(int, icmp6lim_curr_jitter[RATELIM_MAX]) = {0}; 2775 #define V_icmp6lim_curr_jitter VNET(icmp6lim_curr_jitter) 2776 2777 VNET_DEFINE_STATIC(u_int, icmp6lim_jitter) = 8; 2778 #define V_icmp6lim_jitter VNET(icmp6lim_jitter) 2779 SYSCTL_PROC(_net_inet6_icmp6, OID_AUTO, icmp6lim_jitter, CTLTYPE_UINT | 2780 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(icmp6lim_jitter), 0, 2781 &sysctl_icmp6lim_and_jitter, "IU", 2782 "Random errppslimit jitter adjustment limit"); 2783 2784 VNET_DEFINE_STATIC(int, icmp6lim_output) = 1; 2785 #define V_icmp6lim_output VNET(icmp6lim_output) 2786 SYSCTL_INT(_net_inet6_icmp6, OID_AUTO, icmp6lim_output, 2787 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(icmp6lim_output), 0, 2788 "Enable logging of ICMPv6 response rate limiting"); 2789 2790 static void 2791 icmp6lim_new_jitter(int which) 2792 { 2793 /* 2794 * Adjust limit +/- to jitter the measurement to deny a side-channel 2795 * port scan as in https://dl.acm.org/doi/10.1145/3372297.3417280 2796 */ 2797 KASSERT(which >= 0 && which < RATELIM_MAX, 2798 ("%s: which %d", __func__, which)); 2799 if (V_icmp6lim_jitter > 0) 2800 V_icmp6lim_curr_jitter[which] = 2801 arc4random_uniform(V_icmp6lim_jitter * 2 + 1) - 2802 V_icmp6lim_jitter; 2803 } 2804 2805 static int 2806 sysctl_icmp6lim_and_jitter(SYSCTL_HANDLER_ARGS) 2807 { 2808 uint32_t new; 2809 int error; 2810 bool lim; 2811 2812 MPASS(oidp->oid_arg1 == &VNET_NAME(icmp6errppslim) || 2813 oidp->oid_arg1 == &VNET_NAME(icmp6lim_jitter)); 2814 2815 lim = (oidp->oid_arg1 == &VNET_NAME(icmp6errppslim)); 2816 new = lim ? V_icmp6errppslim : V_icmp6lim_jitter; 2817 error = sysctl_handle_int(oidp, &new, 0, req); 2818 if (error == 0 && req->newptr) { 2819 if (lim) { 2820 if (new != 0 && new <= V_icmp6lim_jitter) 2821 error = EINVAL; 2822 else 2823 V_icmp6errppslim = new; 2824 } else { 2825 if (new >= V_icmp6errppslim) 2826 error = EINVAL; 2827 else { 2828 V_icmp6lim_jitter = new; 2829 for (int i = 0; i < RATELIM_MAX; i++) { 2830 icmp6lim_new_jitter(i); 2831 } 2832 } 2833 } 2834 } 2835 MPASS(V_icmp6errppslim == 0 || V_icmp6errppslim > V_icmp6lim_jitter); 2836 2837 return (error); 2838 } 2839 2840 2841 VNET_DEFINE_STATIC(struct counter_rate, icmp6_rates[RATELIM_MAX]); 2842 #define V_icmp6_rates VNET(icmp6_rates) 2843 2844 static void 2845 icmp6_ratelimit_init(void) 2846 { 2847 2848 for (int i = 0; i < RATELIM_MAX; i++) { 2849 V_icmp6_rates[i].cr_rate = counter_u64_alloc(M_WAITOK); 2850 V_icmp6_rates[i].cr_ticks = ticks; 2851 icmp6lim_new_jitter(i); 2852 } 2853 } 2854 VNET_SYSINIT(icmp6_ratelimit, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY, 2855 icmp6_ratelimit_init, NULL); 2856 2857 #ifdef VIMAGE 2858 static void 2859 icmp6_ratelimit_uninit(void) 2860 { 2861 2862 for (int i = 0; i < RATELIM_MAX; i++) 2863 counter_u64_free(V_icmp6_rates[i].cr_rate); 2864 } 2865 VNET_SYSUNINIT(icmp6_ratelimit, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD, 2866 icmp6_ratelimit_uninit, NULL); 2867 #endif 2868 2869 /* 2870 * Perform rate limit check. 2871 * Returns 0 if it is okay to send the icmp6 packet. 2872 * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate 2873 * limitation. 2874 * 2875 * XXX per-destination/type check necessary? 2876 * 2877 * dst - not used at this moment 2878 * code - not used at this moment 2879 */ 2880 int 2881 icmp6_ratelimit(const struct in6_addr *dst, const int type, const int code) 2882 { 2883 ratelim_which which; 2884 int64_t pps; 2885 2886 if (V_icmp6errppslim == 0) 2887 return (0); 2888 2889 switch (type) { 2890 case ICMP6_PARAM_PROB: 2891 which = RATELIM_PARAM_PROB; 2892 break; 2893 case ICMP6_PACKET_TOO_BIG: 2894 which = RATELIM_TOO_BIG; 2895 break; 2896 case ICMP6_DST_UNREACH: 2897 which = RATELIM_UNREACH; 2898 break; 2899 case ICMP6_TIME_EXCEEDED: 2900 which = RATELIM_TEXCEED; 2901 break; 2902 case ND_REDIRECT: 2903 which = RATELIM_REDIR; 2904 break; 2905 case ICMP6_ECHO_REPLY: 2906 which = RATELIM_REPLY; 2907 break; 2908 default: 2909 which = RATELIM_OTHER; 2910 break; 2911 }; 2912 2913 pps = counter_ratecheck(&V_icmp6_rates[which], V_icmp6errppslim + 2914 V_icmp6lim_curr_jitter[which]); 2915 if (pps > 0) { 2916 if (V_icmp6lim_output) 2917 log(LOG_NOTICE, "Limiting ICMPv6 %s output from %jd " 2918 "to %d packets/sec\n", icmp6_rate_descrs[which], 2919 (intmax_t )pps, V_icmp6errppslim + 2920 V_icmp6lim_curr_jitter[which]); 2921 icmp6lim_new_jitter(which); 2922 } 2923 if (pps == -1) { 2924 ICMP6STAT_INC(icp6s_toofreq); 2925 return (-1); 2926 } 2927 2928 return (0); 2929 } 2930