1 /* $NetBSD: icmp6.c,v 1.186 2016/05/18 08:40:51 ozaki-r Exp $ */ 2 /* $KAME: icmp6.c,v 1.217 2001/06/20 15:03:29 jinmei Exp $ */ 3 4 /* 5 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the project nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 /* 34 * Copyright (c) 1982, 1986, 1988, 1993 35 * The Regents of the University of California. All rights reserved. 36 * 37 * Redistribution and use in source and binary forms, with or without 38 * modification, are permitted provided that the following conditions 39 * are met: 40 * 1. Redistributions of source code must retain the above copyright 41 * notice, this list of conditions and the following disclaimer. 42 * 2. Redistributions in binary form must reproduce the above copyright 43 * notice, this list of conditions and the following disclaimer in the 44 * documentation and/or other materials provided with the distribution. 45 * 3. Neither the name of the University nor the names of its contributors 46 * may be used to endorse or promote products derived from this software 47 * without specific prior written permission. 48 * 49 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 50 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 51 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 52 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 53 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 54 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 55 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 56 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 57 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 58 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 59 * SUCH DAMAGE. 60 * 61 * @(#)ip_icmp.c 8.2 (Berkeley) 1/4/94 62 */ 63 64 #include <sys/cdefs.h> 65 __KERNEL_RCSID(0, "$NetBSD: icmp6.c,v 1.186 2016/05/18 08:40:51 ozaki-r Exp $"); 66 67 #ifdef _KERNEL_OPT 68 #include "opt_inet.h" 69 #include "opt_ipsec.h" 70 #endif 71 72 #include <sys/param.h> 73 #include <sys/systm.h> 74 #include <sys/kmem.h> 75 #include <sys/mbuf.h> 76 #include <sys/protosw.h> 77 #include <sys/socket.h> 78 #include <sys/socketvar.h> 79 #include <sys/time.h> 80 #include <sys/kernel.h> 81 #include <sys/syslog.h> 82 #include <sys/domain.h> 83 #include <sys/sysctl.h> 84 85 #include <net/if.h> 86 #include <net/route.h> 87 #include <net/if_dl.h> 88 #include <net/if_types.h> 89 90 #include <netinet/in.h> 91 #include <netinet/in_var.h> 92 #include <netinet/ip6.h> 93 #include <netinet6/ip6_var.h> 94 #include <netinet6/ip6_private.h> 95 #include <netinet/icmp6.h> 96 #include <netinet6/icmp6_private.h> 97 #include <netinet6/mld6_var.h> 98 #include <netinet6/in6_pcb.h> 99 #include <netinet6/nd6.h> 100 #include <netinet6/in6_ifattach.h> 101 #include <netinet6/ip6protosw.h> 102 #include <netinet6/scope6_var.h> 103 104 #ifdef IPSEC 105 #include <netipsec/ipsec.h> 106 #include <netipsec/key.h> 107 #endif 108 109 110 #include "faith.h" 111 #if defined(NFAITH) && 0 < NFAITH 112 #include <net/if_faith.h> 113 #endif 114 115 #include <net/net_osdep.h> 116 117 extern struct domain inet6domain; 118 119 percpu_t *icmp6stat_percpu; 120 121 extern struct inpcbtable raw6cbtable; 122 extern int icmp6errppslim; 123 static int icmp6errpps_count = 0; 124 static struct timeval icmp6errppslim_last; 125 extern int icmp6_nodeinfo; 126 127 /* 128 * List of callbacks to notify when Path MTU changes are made. 129 */ 130 struct icmp6_mtudisc_callback { 131 LIST_ENTRY(icmp6_mtudisc_callback) mc_list; 132 void (*mc_func)(struct in6_addr *); 133 }; 134 135 LIST_HEAD(, icmp6_mtudisc_callback) icmp6_mtudisc_callbacks = 136 LIST_HEAD_INITIALIZER(&icmp6_mtudisc_callbacks); 137 138 static struct rttimer_queue *icmp6_mtudisc_timeout_q = NULL; 139 extern int pmtu_expire; 140 141 /* XXX do these values make any sense? */ 142 static int icmp6_mtudisc_hiwat = 1280; 143 static int icmp6_mtudisc_lowat = 256; 144 145 /* 146 * keep track of # of redirect routes. 147 */ 148 static struct rttimer_queue *icmp6_redirect_timeout_q = NULL; 149 150 /* XXX experimental, turned off */ 151 static int icmp6_redirect_hiwat = -1; 152 static int icmp6_redirect_lowat = -1; 153 154 static void icmp6_errcount(u_int, int, int); 155 static int icmp6_rip6_input(struct mbuf **, int); 156 static int icmp6_ratelimit(const struct in6_addr *, const int, const int); 157 static const char *icmp6_redirect_diag(struct in6_addr *, 158 struct in6_addr *, struct in6_addr *); 159 static struct mbuf *ni6_input(struct mbuf *, int); 160 static struct mbuf *ni6_nametodns(const char *, int, int); 161 static int ni6_dnsmatch(const char *, int, const char *, int); 162 static int ni6_addrs(struct icmp6_nodeinfo *, struct mbuf *, 163 struct ifnet **, char *); 164 static int ni6_store_addrs(struct icmp6_nodeinfo *, struct icmp6_nodeinfo *, 165 struct ifnet *, int); 166 static int icmp6_notify_error(struct mbuf *, int, int, int); 167 static struct rtentry *icmp6_mtudisc_clone(struct sockaddr *); 168 static void icmp6_mtudisc_timeout(struct rtentry *, struct rttimer *); 169 static void icmp6_redirect_timeout(struct rtentry *, struct rttimer *); 170 static void sysctl_net_inet6_icmp6_setup(struct sysctllog **); 171 172 173 void 174 icmp6_init(void) 175 { 176 177 sysctl_net_inet6_icmp6_setup(NULL); 178 mld_init(); 179 icmp6_mtudisc_timeout_q = rt_timer_queue_create(pmtu_expire); 180 icmp6_redirect_timeout_q = rt_timer_queue_create(icmp6_redirtimeout); 181 182 icmp6stat_percpu = percpu_alloc(sizeof(uint64_t) * ICMP6_NSTATS); 183 } 184 185 static void 186 icmp6_errcount(u_int base, int type, int code) 187 { 188 switch (type) { 189 case ICMP6_DST_UNREACH: 190 switch (code) { 191 case ICMP6_DST_UNREACH_NOROUTE: 192 ICMP6_STATINC(base + ICMP6_ERRSTAT_DST_UNREACH_NOROUTE); 193 return; 194 case ICMP6_DST_UNREACH_ADMIN: 195 ICMP6_STATINC(base + ICMP6_ERRSTAT_DST_UNREACH_ADMIN); 196 return; 197 case ICMP6_DST_UNREACH_BEYONDSCOPE: 198 ICMP6_STATINC(base + 199 ICMP6_ERRSTAT_DST_UNREACH_BEYONDSCOPE); 200 return; 201 case ICMP6_DST_UNREACH_ADDR: 202 ICMP6_STATINC(base + ICMP6_ERRSTAT_DST_UNREACH_ADDR); 203 return; 204 case ICMP6_DST_UNREACH_NOPORT: 205 ICMP6_STATINC(base + ICMP6_ERRSTAT_DST_UNREACH_NOPORT); 206 return; 207 } 208 break; 209 case ICMP6_PACKET_TOO_BIG: 210 ICMP6_STATINC(base + ICMP6_ERRSTAT_PACKET_TOO_BIG); 211 return; 212 case ICMP6_TIME_EXCEEDED: 213 switch (code) { 214 case ICMP6_TIME_EXCEED_TRANSIT: 215 ICMP6_STATINC(base + ICMP6_ERRSTAT_TIME_EXCEED_TRANSIT); 216 return; 217 case ICMP6_TIME_EXCEED_REASSEMBLY: 218 ICMP6_STATINC(base + 219 ICMP6_ERRSTAT_TIME_EXCEED_REASSEMBLY); 220 return; 221 } 222 break; 223 case ICMP6_PARAM_PROB: 224 switch (code) { 225 case ICMP6_PARAMPROB_HEADER: 226 ICMP6_STATINC(base + ICMP6_ERRSTAT_PARAMPROB_HEADER); 227 return; 228 case ICMP6_PARAMPROB_NEXTHEADER: 229 ICMP6_STATINC(base + 230 ICMP6_ERRSTAT_PARAMPROB_NEXTHEADER); 231 return; 232 case ICMP6_PARAMPROB_OPTION: 233 ICMP6_STATINC(base + ICMP6_ERRSTAT_PARAMPROB_OPTION); 234 return; 235 } 236 break; 237 case ND_REDIRECT: 238 ICMP6_STATINC(base + ICMP6_ERRSTAT_REDIRECT); 239 return; 240 } 241 ICMP6_STATINC(base + ICMP6_ERRSTAT_UNKNOWN); 242 } 243 244 /* 245 * Register a Path MTU Discovery callback. 246 */ 247 void 248 icmp6_mtudisc_callback_register(void (*func)(struct in6_addr *)) 249 { 250 struct icmp6_mtudisc_callback *mc; 251 252 for (mc = LIST_FIRST(&icmp6_mtudisc_callbacks); mc != NULL; 253 mc = LIST_NEXT(mc, mc_list)) { 254 if (mc->mc_func == func) 255 return; 256 } 257 258 mc = kmem_alloc(sizeof(*mc), KM_SLEEP); 259 mc->mc_func = func; 260 LIST_INSERT_HEAD(&icmp6_mtudisc_callbacks, mc, mc_list); 261 } 262 263 /* 264 * A wrapper function for icmp6_error() necessary when the erroneous packet 265 * may not contain enough scope zone information. 266 */ 267 void 268 icmp6_error2(struct mbuf *m, int type, int code, int param, 269 struct ifnet *ifp) 270 { 271 struct ip6_hdr *ip6; 272 273 if (ifp == NULL) 274 return; 275 276 if (m->m_len < sizeof(struct ip6_hdr)) { 277 m = m_pullup(m, sizeof(struct ip6_hdr)); 278 if (m == NULL) 279 return; 280 } 281 282 ip6 = mtod(m, struct ip6_hdr *); 283 284 if (in6_setscope(&ip6->ip6_src, ifp, NULL) != 0) 285 return; 286 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0) 287 return; 288 289 icmp6_error(m, type, code, param); 290 } 291 292 /* 293 * Generate an error packet of type error in response to bad IP6 packet. 294 */ 295 void 296 icmp6_error(struct mbuf *m, int type, int code, int param) 297 { 298 struct ip6_hdr *oip6, *nip6; 299 struct icmp6_hdr *icmp6; 300 u_int preplen; 301 int off; 302 int nxt; 303 304 ICMP6_STATINC(ICMP6_STAT_ERROR); 305 306 /* count per-type-code statistics */ 307 icmp6_errcount(ICMP6_STAT_OUTERRHIST, type, code); 308 309 if (m->m_flags & M_DECRYPTED) { 310 ICMP6_STATINC(ICMP6_STAT_CANTERROR); 311 goto freeit; 312 } 313 314 if (M_UNWRITABLE(m, sizeof(struct ip6_hdr)) && 315 (m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) 316 return; 317 oip6 = mtod(m, struct ip6_hdr *); 318 319 /* 320 * If the destination address of the erroneous packet is a multicast 321 * address, or the packet was sent using link-layer multicast, 322 * we should basically suppress sending an error (RFC 2463, Section 323 * 2.4). 324 * We have two exceptions (the item e.2 in that section): 325 * - the Pakcet Too Big message can be sent for path MTU discovery. 326 * - the Parameter Problem Message that can be allowed an icmp6 error 327 * in the option type field. This check has been done in 328 * ip6_unknown_opt(), so we can just check the type and code. 329 */ 330 if ((m->m_flags & (M_BCAST|M_MCAST) || 331 IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) && 332 (type != ICMP6_PACKET_TOO_BIG && 333 (type != ICMP6_PARAM_PROB || 334 code != ICMP6_PARAMPROB_OPTION))) 335 goto freeit; 336 337 /* 338 * RFC 2463, 2.4 (e.5): source address check. 339 * XXX: the case of anycast source? 340 */ 341 if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) || 342 IN6_IS_ADDR_MULTICAST(&oip6->ip6_src)) 343 goto freeit; 344 345 /* 346 * If we are about to send ICMPv6 against ICMPv6 error/redirect, 347 * don't do it. 348 */ 349 nxt = -1; 350 off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt); 351 if (off >= 0 && nxt == IPPROTO_ICMPV6) { 352 struct icmp6_hdr *icp; 353 354 IP6_EXTHDR_GET(icp, struct icmp6_hdr *, m, off, 355 sizeof(*icp)); 356 if (icp == NULL) { 357 ICMP6_STATINC(ICMP6_STAT_TOOSHORT); 358 return; 359 } 360 if (icp->icmp6_type < ICMP6_ECHO_REQUEST || 361 icp->icmp6_type == ND_REDIRECT) { 362 /* 363 * ICMPv6 error 364 * Special case: for redirect (which is 365 * informational) we must not send icmp6 error. 366 */ 367 ICMP6_STATINC(ICMP6_STAT_CANTERROR); 368 goto freeit; 369 } else { 370 /* ICMPv6 informational - send the error */ 371 } 372 } 373 #if 0 /* controversial */ 374 else if (off >= 0 && nxt == IPPROTO_ESP) { 375 /* 376 * It could be ICMPv6 error inside ESP. Take a safer side, 377 * don't respond. 378 */ 379 ICMP6_STATINC(ICMP6_STAT_CANTERROR); 380 goto freeit; 381 } 382 #endif 383 else { 384 /* non-ICMPv6 - send the error */ 385 } 386 387 oip6 = mtod(m, struct ip6_hdr *); /* adjust pointer */ 388 389 /* Finally, do rate limitation check. */ 390 if (icmp6_ratelimit(&oip6->ip6_src, type, code)) { 391 ICMP6_STATINC(ICMP6_STAT_TOOFREQ); 392 goto freeit; 393 } 394 395 /* 396 * OK, ICMP6 can be generated. 397 */ 398 399 if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN) 400 m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len); 401 402 preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 403 M_PREPEND(m, preplen, M_DONTWAIT); 404 if (m && M_UNWRITABLE(m, preplen)) 405 m = m_pullup(m, preplen); 406 if (m == NULL) { 407 nd6log(LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__); 408 return; 409 } 410 411 nip6 = mtod(m, struct ip6_hdr *); 412 nip6->ip6_src = oip6->ip6_src; 413 nip6->ip6_dst = oip6->ip6_dst; 414 415 in6_clearscope(&oip6->ip6_src); 416 in6_clearscope(&oip6->ip6_dst); 417 418 icmp6 = (struct icmp6_hdr *)(nip6 + 1); 419 icmp6->icmp6_type = type; 420 icmp6->icmp6_code = code; 421 icmp6->icmp6_pptr = htonl((u_int32_t)param); 422 423 /* 424 * icmp6_reflect() is designed to be in the input path. 425 * icmp6_error() can be called from both input and output path, 426 * and if we are in output path rcvif could contain bogus value. 427 * clear m->m_pkthdr.rcvif for safety, we should have enough scope 428 * information in ip header (nip6). 429 */ 430 m->m_pkthdr.rcvif = NULL; 431 432 ICMP6_STATINC(ICMP6_STAT_OUTHIST + type); 433 icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */ 434 435 return; 436 437 freeit: 438 /* 439 * If we can't tell whether or not we can generate ICMP6, free it. 440 */ 441 m_freem(m); 442 } 443 444 /* 445 * Process a received ICMP6 message. 446 */ 447 int 448 icmp6_input(struct mbuf **mp, int *offp, int proto) 449 { 450 struct mbuf *m = *mp, *n; 451 struct ip6_hdr *ip6, *nip6; 452 struct icmp6_hdr *icmp6, *nicmp6; 453 int off = *offp; 454 int icmp6len = m->m_pkthdr.len - *offp; 455 int code, sum, noff, i; 456 struct ifnet *rcvif = m->m_pkthdr.rcvif; 457 458 #define ICMP6_MAXLEN (sizeof(*nip6) + sizeof(*nicmp6) + 4) 459 KASSERT(ICMP6_MAXLEN < MCLBYTES); 460 icmp6_ifstat_inc(rcvif, ifs6_in_msg); 461 462 /* 463 * Locate icmp6 structure in mbuf, and check 464 * that not corrupted and of at least minimum length 465 */ 466 467 if (icmp6len < sizeof(struct icmp6_hdr)) { 468 ICMP6_STATINC(ICMP6_STAT_TOOSHORT); 469 icmp6_ifstat_inc(rcvif, ifs6_in_error); 470 goto freeit; 471 } 472 473 i = off + sizeof(*icmp6); 474 if ((m->m_len < i || M_READONLY(m)) && (m = m_pullup(m, i)) == 0) { 475 ICMP6_STATINC(ICMP6_STAT_TOOSHORT); 476 #if 0 /* m is 0 here */ 477 icmp6_ifstat_inc(rcvif, ifs6_in_error); 478 #endif 479 goto freeit; 480 } 481 ip6 = mtod(m, struct ip6_hdr *); 482 /* 483 * calculate the checksum 484 */ 485 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6)); 486 if (icmp6 == NULL) { 487 ICMP6_STATINC(ICMP6_STAT_TOOSHORT); 488 /* m is invalid */ 489 /*icmp6_ifstat_inc(rcvif, ifs6_in_error);*/ 490 return IPPROTO_DONE; 491 } 492 KASSERT(IP6_HDR_ALIGNED_P(icmp6)); 493 code = icmp6->icmp6_code; 494 495 if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) { 496 nd6log(LOG_ERR, "ICMP6 checksum error(%d|%x) %s\n", 497 icmp6->icmp6_type, sum, ip6_sprintf(&ip6->ip6_src)); 498 ICMP6_STATINC(ICMP6_STAT_CHECKSUM); 499 icmp6_ifstat_inc(rcvif, ifs6_in_error); 500 goto freeit; 501 } 502 503 #if defined(NFAITH) && 0 < NFAITH 504 if (faithprefix(&ip6->ip6_dst)) { 505 /* 506 * Deliver very specific ICMP6 type only. 507 * This is important to deliver TOOBIG. Otherwise PMTUD 508 * will not work. 509 */ 510 switch (icmp6->icmp6_type) { 511 case ICMP6_DST_UNREACH: 512 case ICMP6_PACKET_TOO_BIG: 513 case ICMP6_TIME_EXCEEDED: 514 break; 515 default: 516 goto freeit; 517 } 518 } 519 #endif 520 521 ICMP6_STATINC(ICMP6_STAT_INHIST + icmp6->icmp6_type); 522 523 switch (icmp6->icmp6_type) { 524 case ICMP6_DST_UNREACH: 525 icmp6_ifstat_inc(rcvif, ifs6_in_dstunreach); 526 switch (code) { 527 case ICMP6_DST_UNREACH_NOROUTE: 528 code = PRC_UNREACH_NET; 529 break; 530 case ICMP6_DST_UNREACH_ADMIN: 531 icmp6_ifstat_inc(rcvif, ifs6_in_adminprohib); 532 code = PRC_UNREACH_PROTOCOL; /* is this a good code? */ 533 break; 534 case ICMP6_DST_UNREACH_ADDR: 535 code = PRC_HOSTDEAD; 536 break; 537 #ifdef COMPAT_RFC1885 538 case ICMP6_DST_UNREACH_NOTNEIGHBOR: 539 code = PRC_UNREACH_SRCFAIL; 540 break; 541 #else 542 case ICMP6_DST_UNREACH_BEYONDSCOPE: 543 /* I mean "source address was incorrect." */ 544 code = PRC_UNREACH_NET; 545 break; 546 #endif 547 case ICMP6_DST_UNREACH_NOPORT: 548 code = PRC_UNREACH_PORT; 549 break; 550 default: 551 goto badcode; 552 } 553 goto deliver; 554 555 case ICMP6_PACKET_TOO_BIG: 556 icmp6_ifstat_inc(rcvif, ifs6_in_pkttoobig); 557 558 /* 559 * MTU is checked in icmp6_mtudisc. 560 */ 561 code = PRC_MSGSIZE; 562 563 /* 564 * Updating the path MTU will be done after examining 565 * intermediate extension headers. 566 */ 567 goto deliver; 568 569 case ICMP6_TIME_EXCEEDED: 570 icmp6_ifstat_inc(rcvif, ifs6_in_timeexceed); 571 switch (code) { 572 case ICMP6_TIME_EXCEED_TRANSIT: 573 code = PRC_TIMXCEED_INTRANS; 574 break; 575 case ICMP6_TIME_EXCEED_REASSEMBLY: 576 code = PRC_TIMXCEED_REASS; 577 break; 578 default: 579 goto badcode; 580 } 581 goto deliver; 582 583 case ICMP6_PARAM_PROB: 584 icmp6_ifstat_inc(rcvif, ifs6_in_paramprob); 585 switch (code) { 586 case ICMP6_PARAMPROB_NEXTHEADER: 587 code = PRC_UNREACH_PROTOCOL; 588 break; 589 case ICMP6_PARAMPROB_HEADER: 590 case ICMP6_PARAMPROB_OPTION: 591 code = PRC_PARAMPROB; 592 break; 593 default: 594 goto badcode; 595 } 596 goto deliver; 597 598 case ICMP6_ECHO_REQUEST: 599 icmp6_ifstat_inc(rcvif, ifs6_in_echo); 600 if (code != 0) 601 goto badcode; 602 /* 603 * Copy mbuf to send to two data paths: userland socket(s), 604 * and to the querier (echo reply). 605 * m: a copy for socket, n: a copy for querier 606 * 607 * If the first mbuf is shared, or the first mbuf is too short, 608 * copy the first part of the data into a fresh mbuf. 609 * Otherwise, we will wrongly overwrite both copies. 610 */ 611 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 612 /* Give up local */ 613 n = m; 614 m = NULL; 615 } else if (M_READONLY(n) || 616 n->m_len < off + sizeof(struct icmp6_hdr)) { 617 struct mbuf *n0 = n; 618 619 /* 620 * Prepare an internal mbuf. m_pullup() doesn't 621 * always copy the length we specified. 622 */ 623 if ((n = m_dup(n0, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 624 /* Give up local */ 625 n = m; 626 m = NULL; 627 } 628 m_freem(n0); 629 } 630 IP6_EXTHDR_GET(nicmp6, struct icmp6_hdr *, n, off, 631 sizeof(*nicmp6)); 632 if (nicmp6 == NULL) 633 goto freeit; 634 nicmp6->icmp6_type = ICMP6_ECHO_REPLY; 635 nicmp6->icmp6_code = 0; 636 if (n) { 637 uint64_t *icmp6s = ICMP6_STAT_GETREF(); 638 icmp6s[ICMP6_STAT_REFLECT]++; 639 icmp6s[ICMP6_STAT_OUTHIST + ICMP6_ECHO_REPLY]++; 640 ICMP6_STAT_PUTREF(); 641 icmp6_reflect(n, off); 642 } 643 if (!m) 644 goto freeit; 645 break; 646 647 case ICMP6_ECHO_REPLY: 648 icmp6_ifstat_inc(rcvif, ifs6_in_echoreply); 649 if (code != 0) 650 goto badcode; 651 break; 652 653 case MLD_LISTENER_QUERY: 654 case MLD_LISTENER_REPORT: 655 if (icmp6len < sizeof(struct mld_hdr)) 656 goto badlen; 657 if (icmp6->icmp6_type == MLD_LISTENER_QUERY) /* XXX: ugly... */ 658 icmp6_ifstat_inc(rcvif, ifs6_in_mldquery); 659 else 660 icmp6_ifstat_inc(rcvif, ifs6_in_mldreport); 661 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 662 /* give up local */ 663 mld_input(m, off); 664 m = NULL; 665 goto freeit; 666 } 667 mld_input(n, off); 668 /* m stays. */ 669 break; 670 671 case MLD_LISTENER_DONE: 672 icmp6_ifstat_inc(rcvif, ifs6_in_mlddone); 673 if (icmp6len < sizeof(struct mld_hdr)) /* necessary? */ 674 goto badlen; 675 break; /* nothing to be done in kernel */ 676 677 case MLD_MTRACE_RESP: 678 case MLD_MTRACE: 679 /* XXX: these two are experimental. not officially defined. */ 680 /* XXX: per-interface statistics? */ 681 break; /* just pass it to applications */ 682 683 case ICMP6_WRUREQUEST: /* ICMP6_FQDN_QUERY */ 684 { 685 enum { WRU, FQDN } mode; 686 687 if (!icmp6_nodeinfo) 688 break; 689 690 if (icmp6len == sizeof(struct icmp6_hdr) + 4) 691 mode = WRU; 692 else if (icmp6len >= sizeof(struct icmp6_nodeinfo)) 693 mode = FQDN; 694 else 695 goto badlen; 696 697 if (mode == FQDN) { 698 n = m_copym(m, 0, M_COPYALL, M_DONTWAIT); 699 if (n) 700 n = ni6_input(n, off); 701 /* XXX meaningless if n == NULL */ 702 noff = sizeof(struct ip6_hdr); 703 } else { 704 u_char *p; 705 int maxhlen; 706 707 if ((icmp6_nodeinfo & 5) != 5) 708 break; 709 710 if (code != 0) 711 goto badcode; 712 MGETHDR(n, M_DONTWAIT, m->m_type); 713 if (n && ICMP6_MAXLEN > MHLEN) { 714 MCLGET(n, M_DONTWAIT); 715 if ((n->m_flags & M_EXT) == 0) { 716 m_free(n); 717 n = NULL; 718 } 719 } 720 if (n == NULL) { 721 /* Give up remote */ 722 break; 723 } 724 n->m_pkthdr.rcvif = NULL; 725 n->m_len = 0; 726 maxhlen = M_TRAILINGSPACE(n) - ICMP6_MAXLEN; 727 if (maxhlen < 0) 728 break; 729 if (maxhlen > hostnamelen) 730 maxhlen = hostnamelen; 731 /* 732 * Copy IPv6 and ICMPv6 only. 733 */ 734 nip6 = mtod(n, struct ip6_hdr *); 735 bcopy(ip6, nip6, sizeof(struct ip6_hdr)); 736 nicmp6 = (struct icmp6_hdr *)(nip6 + 1); 737 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr)); 738 p = (u_char *)(nicmp6 + 1); 739 memset(p, 0, 4); 740 bcopy(hostname, p + 4, maxhlen); /* meaningless TTL */ 741 noff = sizeof(struct ip6_hdr); 742 M_COPY_PKTHDR(n, m); /* just for rcvif */ 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 #undef hostnamelen 749 if (n) { 750 uint64_t *icmp6s = ICMP6_STAT_GETREF(); 751 icmp6s[ICMP6_STAT_REFLECT]++; 752 icmp6s[ICMP6_STAT_OUTHIST + ICMP6_WRUREPLY]++; 753 ICMP6_STAT_PUTREF(); 754 icmp6_reflect(n, noff); 755 } 756 break; 757 } 758 759 case ICMP6_WRUREPLY: 760 if (code != 0) 761 goto badcode; 762 break; 763 764 case ND_ROUTER_SOLICIT: 765 icmp6_ifstat_inc(rcvif, ifs6_in_routersolicit); 766 if (code != 0) 767 goto badcode; 768 if (icmp6len < sizeof(struct nd_router_solicit)) 769 goto badlen; 770 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 771 /* give up local */ 772 nd6_rs_input(m, off, icmp6len); 773 m = NULL; 774 goto freeit; 775 } 776 nd6_rs_input(n, off, icmp6len); 777 /* m stays. */ 778 break; 779 780 case ND_ROUTER_ADVERT: 781 icmp6_ifstat_inc(rcvif, ifs6_in_routeradvert); 782 if (code != 0) 783 goto badcode; 784 if (icmp6len < sizeof(struct nd_router_advert)) 785 goto badlen; 786 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 787 /* give up local */ 788 nd6_ra_input(m, off, icmp6len); 789 m = NULL; 790 goto freeit; 791 } 792 nd6_ra_input(n, off, icmp6len); 793 /* m stays. */ 794 break; 795 796 case ND_NEIGHBOR_SOLICIT: 797 icmp6_ifstat_inc(rcvif, ifs6_in_neighborsolicit); 798 if (code != 0) 799 goto badcode; 800 if (icmp6len < sizeof(struct nd_neighbor_solicit)) 801 goto badlen; 802 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 803 /* give up local */ 804 nd6_ns_input(m, off, icmp6len); 805 m = NULL; 806 goto freeit; 807 } 808 nd6_ns_input(n, off, icmp6len); 809 /* m stays. */ 810 break; 811 812 case ND_NEIGHBOR_ADVERT: 813 icmp6_ifstat_inc(rcvif, ifs6_in_neighboradvert); 814 if (code != 0) 815 goto badcode; 816 if (icmp6len < sizeof(struct nd_neighbor_advert)) 817 goto badlen; 818 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 819 /* give up local */ 820 nd6_na_input(m, off, icmp6len); 821 m = NULL; 822 goto freeit; 823 } 824 nd6_na_input(n, off, icmp6len); 825 /* m stays. */ 826 break; 827 828 case ND_REDIRECT: 829 icmp6_ifstat_inc(rcvif, ifs6_in_redirect); 830 if (code != 0) 831 goto badcode; 832 if (icmp6len < sizeof(struct nd_redirect)) 833 goto badlen; 834 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { 835 /* give up local */ 836 icmp6_redirect_input(m, off); 837 m = NULL; 838 goto freeit; 839 } 840 icmp6_redirect_input(n, off); 841 /* m stays. */ 842 break; 843 844 case ICMP6_ROUTER_RENUMBERING: 845 if (code != ICMP6_ROUTER_RENUMBERING_COMMAND && 846 code != ICMP6_ROUTER_RENUMBERING_RESULT) 847 goto badcode; 848 if (icmp6len < sizeof(struct icmp6_router_renum)) 849 goto badlen; 850 break; 851 852 default: 853 nd6log(LOG_DEBUG, "unknown type %d(src=%s, dst=%s, ifid=%d)\n", 854 icmp6->icmp6_type, ip6_sprintf(&ip6->ip6_src), 855 ip6_sprintf(&ip6->ip6_dst), 856 rcvif ? rcvif->if_index : 0); 857 if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) { 858 /* ICMPv6 error: MUST deliver it by spec... */ 859 code = PRC_NCMDS; 860 /* deliver */ 861 } else { 862 /* ICMPv6 informational: MUST not deliver */ 863 break; 864 } 865 deliver: 866 if (icmp6_notify_error(m, off, icmp6len, code)) { 867 /* In this case, m should've been freed. */ 868 return (IPPROTO_DONE); 869 } 870 break; 871 872 badcode: 873 ICMP6_STATINC(ICMP6_STAT_BADCODE); 874 break; 875 876 badlen: 877 ICMP6_STATINC(ICMP6_STAT_BADLEN); 878 break; 879 } 880 881 /* deliver the packet to appropriate sockets */ 882 icmp6_rip6_input(&m, *offp); 883 884 return IPPROTO_DONE; 885 886 freeit: 887 m_freem(m); 888 return IPPROTO_DONE; 889 } 890 891 static int 892 icmp6_notify_error(struct mbuf *m, int off, int icmp6len, int code) 893 { 894 struct icmp6_hdr *icmp6; 895 struct ip6_hdr *eip6; 896 u_int32_t notifymtu; 897 struct sockaddr_in6 icmp6src, icmp6dst; 898 899 if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) { 900 ICMP6_STATINC(ICMP6_STAT_TOOSHORT); 901 goto freeit; 902 } 903 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, 904 sizeof(*icmp6) + sizeof(struct ip6_hdr)); 905 if (icmp6 == NULL) { 906 ICMP6_STATINC(ICMP6_STAT_TOOSHORT); 907 return (-1); 908 } 909 eip6 = (struct ip6_hdr *)(icmp6 + 1); 910 911 /* Detect the upper level protocol */ 912 { 913 void (*ctlfunc)(int, struct sockaddr *, void *); 914 u_int8_t nxt = eip6->ip6_nxt; 915 int eoff = off + sizeof(struct icmp6_hdr) + 916 sizeof(struct ip6_hdr); 917 struct ip6ctlparam ip6cp; 918 struct in6_addr *finaldst = NULL; 919 int icmp6type = icmp6->icmp6_type; 920 struct ip6_frag *fh; 921 struct ip6_rthdr *rth; 922 struct ip6_rthdr0 *rth0; 923 int rthlen; 924 925 while (1) { /* XXX: should avoid infinite loop explicitly? */ 926 struct ip6_ext *eh; 927 928 switch (nxt) { 929 case IPPROTO_HOPOPTS: 930 case IPPROTO_DSTOPTS: 931 case IPPROTO_AH: 932 IP6_EXTHDR_GET(eh, struct ip6_ext *, m, 933 eoff, sizeof(*eh)); 934 if (eh == NULL) { 935 ICMP6_STATINC(ICMP6_STAT_TOOSHORT); 936 return (-1); 937 } 938 939 if (nxt == IPPROTO_AH) 940 eoff += (eh->ip6e_len + 2) << 2; 941 else 942 eoff += (eh->ip6e_len + 1) << 3; 943 nxt = eh->ip6e_nxt; 944 break; 945 case IPPROTO_ROUTING: 946 /* 947 * When the erroneous packet contains a 948 * routing header, we should examine the 949 * header to determine the final destination. 950 * Otherwise, we can't properly update 951 * information that depends on the final 952 * destination (e.g. path MTU). 953 */ 954 IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m, 955 eoff, sizeof(*rth)); 956 if (rth == NULL) { 957 ICMP6_STATINC(ICMP6_STAT_TOOSHORT); 958 return (-1); 959 } 960 rthlen = (rth->ip6r_len + 1) << 3; 961 /* 962 * XXX: currently there is no 963 * officially defined type other 964 * than type-0. 965 * Note that if the segment left field 966 * is 0, all intermediate hops must 967 * have been passed. 968 */ 969 if (rth->ip6r_segleft && 970 rth->ip6r_type == IPV6_RTHDR_TYPE_0) { 971 int hops; 972 973 IP6_EXTHDR_GET(rth0, 974 struct ip6_rthdr0 *, m, 975 eoff, rthlen); 976 if (rth0 == NULL) { 977 ICMP6_STATINC(ICMP6_STAT_TOOSHORT); 978 return (-1); 979 } 980 /* just ignore a bogus header */ 981 if ((rth0->ip6r0_len % 2) == 0 && 982 (hops = rth0->ip6r0_len/2)) 983 finaldst = (struct in6_addr *)(rth0 + 1) + (hops - 1); 984 } 985 eoff += rthlen; 986 nxt = rth->ip6r_nxt; 987 break; 988 case IPPROTO_FRAGMENT: 989 IP6_EXTHDR_GET(fh, struct ip6_frag *, m, 990 eoff, sizeof(*fh)); 991 if (fh == NULL) { 992 ICMP6_STATINC(ICMP6_STAT_TOOSHORT); 993 return (-1); 994 } 995 /* 996 * Data after a fragment header is meaningless 997 * unless it is the first fragment, but 998 * we'll go to the notify label for path MTU 999 * discovery. 1000 */ 1001 if (fh->ip6f_offlg & IP6F_OFF_MASK) 1002 goto notify; 1003 1004 eoff += sizeof(struct ip6_frag); 1005 nxt = fh->ip6f_nxt; 1006 break; 1007 default: 1008 /* 1009 * This case includes ESP and the No Next 1010 * Header. In such cases going to the notify 1011 * label does not have any meaning 1012 * (i.e. ctlfunc will be NULL), but we go 1013 * anyway since we might have to update 1014 * path MTU information. 1015 */ 1016 goto notify; 1017 } 1018 } 1019 notify: 1020 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, 1021 sizeof(*icmp6) + sizeof(struct ip6_hdr)); 1022 if (icmp6 == NULL) { 1023 ICMP6_STATINC(ICMP6_STAT_TOOSHORT); 1024 return (-1); 1025 } 1026 1027 /* 1028 * retrieve parameters from the inner IPv6 header, and convert 1029 * them into sockaddr structures. 1030 * XXX: there is no guarantee that the source or destination 1031 * addresses of the inner packet are in the same scope zone as 1032 * the addresses of the icmp packet. But there is no other 1033 * way to determine the zone. 1034 */ 1035 eip6 = (struct ip6_hdr *)(icmp6 + 1); 1036 1037 sockaddr_in6_init(&icmp6dst, 1038 (finaldst == NULL) ? &eip6->ip6_dst : finaldst, 0, 0, 0); 1039 if (in6_setscope(&icmp6dst.sin6_addr, m->m_pkthdr.rcvif, NULL)) 1040 goto freeit; 1041 sockaddr_in6_init(&icmp6src, &eip6->ip6_src, 0, 0, 0); 1042 if (in6_setscope(&icmp6src.sin6_addr, m->m_pkthdr.rcvif, NULL)) 1043 goto freeit; 1044 icmp6src.sin6_flowinfo = 1045 (eip6->ip6_flow & IPV6_FLOWLABEL_MASK); 1046 1047 if (finaldst == NULL) 1048 finaldst = &eip6->ip6_dst; 1049 ip6cp.ip6c_m = m; 1050 ip6cp.ip6c_icmp6 = icmp6; 1051 ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1); 1052 ip6cp.ip6c_off = eoff; 1053 ip6cp.ip6c_finaldst = finaldst; 1054 ip6cp.ip6c_src = &icmp6src; 1055 ip6cp.ip6c_nxt = nxt; 1056 1057 if (icmp6type == ICMP6_PACKET_TOO_BIG) { 1058 notifymtu = ntohl(icmp6->icmp6_mtu); 1059 ip6cp.ip6c_cmdarg = (void *)¬ifymtu; 1060 } 1061 1062 ctlfunc = (void (*)(int, struct sockaddr *, void *)) 1063 (inet6sw[ip6_protox[nxt]].pr_ctlinput); 1064 if (ctlfunc) { 1065 (void) (*ctlfunc)(code, (struct sockaddr *)&icmp6dst, 1066 &ip6cp); 1067 } 1068 } 1069 return (0); 1070 1071 freeit: 1072 m_freem(m); 1073 return (-1); 1074 } 1075 1076 void 1077 icmp6_mtudisc_update(struct ip6ctlparam *ip6cp, int validated) 1078 { 1079 unsigned long rtcount; 1080 struct icmp6_mtudisc_callback *mc; 1081 struct in6_addr *dst = ip6cp->ip6c_finaldst; 1082 struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6; 1083 struct mbuf *m = ip6cp->ip6c_m; /* will be necessary for scope issue */ 1084 u_int mtu = ntohl(icmp6->icmp6_mtu); 1085 struct rtentry *rt = NULL; 1086 struct sockaddr_in6 sin6; 1087 1088 /* 1089 * The MTU should not be less than the minimal IPv6 MTU except for the 1090 * hack in ip6_output/ip6_setpmtu where we always include a frag header. 1091 * In that one case, the MTU might be less than 1280. 1092 */ 1093 if (__predict_false(mtu < IPV6_MMTU - sizeof(struct ip6_frag))) { 1094 /* is the mtu even sane? */ 1095 if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8) 1096 return; 1097 if (!validated) 1098 return; 1099 mtu = IPV6_MMTU - sizeof(struct ip6_frag); 1100 } 1101 1102 /* 1103 * allow non-validated cases if memory is plenty, to make traffic 1104 * from non-connected pcb happy. 1105 */ 1106 rtcount = rt_timer_count(icmp6_mtudisc_timeout_q); 1107 if (validated) { 1108 if (0 <= icmp6_mtudisc_hiwat && rtcount > icmp6_mtudisc_hiwat) 1109 return; 1110 else if (0 <= icmp6_mtudisc_lowat && 1111 rtcount > icmp6_mtudisc_lowat) { 1112 /* 1113 * XXX nuke a victim, install the new one. 1114 */ 1115 } 1116 } else { 1117 if (0 <= icmp6_mtudisc_lowat && rtcount > icmp6_mtudisc_lowat) 1118 return; 1119 } 1120 1121 memset(&sin6, 0, sizeof(sin6)); 1122 sin6.sin6_family = PF_INET6; 1123 sin6.sin6_len = sizeof(struct sockaddr_in6); 1124 sin6.sin6_addr = *dst; 1125 if (in6_setscope(&sin6.sin6_addr, m->m_pkthdr.rcvif, NULL)) 1126 return; 1127 1128 rt = icmp6_mtudisc_clone((struct sockaddr *)&sin6); 1129 1130 if (rt && (rt->rt_flags & RTF_HOST) && 1131 !(rt->rt_rmx.rmx_locks & RTV_MTU) && 1132 (rt->rt_rmx.rmx_mtu > mtu || rt->rt_rmx.rmx_mtu == 0)) { 1133 if (mtu < IN6_LINKMTU(rt->rt_ifp)) { 1134 ICMP6_STATINC(ICMP6_STAT_PMTUCHG); 1135 rt->rt_rmx.rmx_mtu = mtu; 1136 } 1137 } 1138 if (rt) { 1139 rtfree(rt); 1140 } 1141 1142 /* 1143 * Notify protocols that the MTU for this destination 1144 * has changed. 1145 */ 1146 for (mc = LIST_FIRST(&icmp6_mtudisc_callbacks); mc != NULL; 1147 mc = LIST_NEXT(mc, mc_list)) 1148 (*mc->mc_func)(&sin6.sin6_addr); 1149 } 1150 1151 /* 1152 * Process a Node Information Query packet, based on 1153 * draft-ietf-ipngwg-icmp-name-lookups-07. 1154 * 1155 * Spec incompatibilities: 1156 * - IPv6 Subject address handling 1157 * - IPv4 Subject address handling support missing 1158 * - Proxy reply (answer even if it's not for me) 1159 * - joins NI group address at in6_ifattach() time only, does not cope 1160 * with hostname changes by sethostname(3) 1161 */ 1162 static struct mbuf * 1163 ni6_input(struct mbuf *m, int off) 1164 { 1165 struct icmp6_nodeinfo *ni6, *nni6; 1166 struct mbuf *n = NULL; 1167 u_int16_t qtype; 1168 int subjlen; 1169 int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); 1170 struct ni_reply_fqdn *fqdn; 1171 int addrs; /* for NI_QTYPE_NODEADDR */ 1172 struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */ 1173 struct sockaddr_in6 sin6; /* ip6_dst */ 1174 struct in6_addr in6_subj; /* subject address */ 1175 struct ip6_hdr *ip6; 1176 int oldfqdn = 0; /* if 1, return pascal string (03 draft) */ 1177 char *subj = NULL; 1178 1179 ip6 = mtod(m, struct ip6_hdr *); 1180 IP6_EXTHDR_GET(ni6, struct icmp6_nodeinfo *, m, off, sizeof(*ni6)); 1181 if (ni6 == NULL) { 1182 /* m is already reclaimed */ 1183 return NULL; 1184 } 1185 1186 /* 1187 * Validate IPv6 destination address. 1188 * 1189 * The Responder must discard the Query without further processing 1190 * unless it is one of the Responder's unicast or anycast addresses, or 1191 * a link-local scope multicast address which the Responder has joined. 1192 * [icmp-name-lookups-07, Section 4.] 1193 */ 1194 sockaddr_in6_init(&sin6, &ip6->ip6_dst, 0, 0, 0); 1195 /* XXX scopeid */ 1196 if (ifa_ifwithaddr((struct sockaddr *)&sin6)) 1197 ; /* unicast/anycast, fine */ 1198 else if (IN6_IS_ADDR_MC_LINKLOCAL(&sin6.sin6_addr)) 1199 ; /* link-local multicast, fine */ 1200 else 1201 goto bad; 1202 1203 /* validate query Subject field. */ 1204 qtype = ntohs(ni6->ni_qtype); 1205 subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo); 1206 switch (qtype) { 1207 case NI_QTYPE_NOOP: 1208 case NI_QTYPE_SUPTYPES: 1209 /* 07 draft */ 1210 if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0) 1211 break; 1212 /* FALLTHROUGH */ 1213 case NI_QTYPE_FQDN: 1214 case NI_QTYPE_NODEADDR: 1215 case NI_QTYPE_IPV4ADDR: 1216 switch (ni6->ni_code) { 1217 case ICMP6_NI_SUBJ_IPV6: 1218 #if ICMP6_NI_SUBJ_IPV6 != 0 1219 case 0: 1220 #endif 1221 /* 1222 * backward compatibility - try to accept 03 draft 1223 * format, where no Subject is present. 1224 */ 1225 if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 && 1226 subjlen == 0) { 1227 oldfqdn++; 1228 break; 1229 } 1230 #if ICMP6_NI_SUBJ_IPV6 != 0 1231 if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6) 1232 goto bad; 1233 #endif 1234 1235 if (subjlen != sizeof(sin6.sin6_addr)) 1236 goto bad; 1237 1238 /* 1239 * Validate Subject address. 1240 * 1241 * Not sure what exactly "address belongs to the node" 1242 * means in the spec, is it just unicast, or what? 1243 * 1244 * At this moment we consider Subject address as 1245 * "belong to the node" if the Subject address equals 1246 * to the IPv6 destination address; validation for 1247 * IPv6 destination address should have done enough 1248 * check for us. 1249 * 1250 * We do not do proxy at this moment. 1251 */ 1252 /* m_pulldown instead of copy? */ 1253 m_copydata(m, off + sizeof(struct icmp6_nodeinfo), 1254 subjlen, (void *)&in6_subj); 1255 if (in6_setscope(&in6_subj, m->m_pkthdr.rcvif, NULL)) 1256 goto bad; 1257 1258 subj = (char *)&in6_subj; 1259 if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &in6_subj)) 1260 break; 1261 1262 /* 1263 * XXX if we are to allow other cases, we should really 1264 * be careful about scope here. 1265 * basically, we should disallow queries toward IPv6 1266 * destination X with subject Y, if scope(X) > scope(Y). 1267 * if we allow scope(X) > scope(Y), it will result in 1268 * information leakage across scope boundary. 1269 */ 1270 goto bad; 1271 1272 case ICMP6_NI_SUBJ_FQDN: 1273 /* 1274 * Validate Subject name with gethostname(3). 1275 * 1276 * The behavior may need some debate, since: 1277 * - we are not sure if the node has FQDN as 1278 * hostname (returned by gethostname(3)). 1279 * - the code does wildcard match for truncated names. 1280 * however, we are not sure if we want to perform 1281 * wildcard match, if gethostname(3) side has 1282 * truncated hostname. 1283 */ 1284 n = ni6_nametodns(hostname, hostnamelen, 0); 1285 if (!n || n->m_next || n->m_len == 0) 1286 goto bad; 1287 IP6_EXTHDR_GET(subj, char *, m, 1288 off + sizeof(struct icmp6_nodeinfo), subjlen); 1289 if (subj == NULL) 1290 goto bad; 1291 if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *), 1292 n->m_len)) { 1293 goto bad; 1294 } 1295 m_freem(n); 1296 n = NULL; 1297 break; 1298 1299 case ICMP6_NI_SUBJ_IPV4: /* XXX: to be implemented? */ 1300 default: 1301 goto bad; 1302 } 1303 break; 1304 } 1305 1306 /* refuse based on configuration. XXX ICMP6_NI_REFUSED? */ 1307 switch (qtype) { 1308 case NI_QTYPE_FQDN: 1309 if ((icmp6_nodeinfo & 1) == 0) 1310 goto bad; 1311 break; 1312 case NI_QTYPE_NODEADDR: 1313 case NI_QTYPE_IPV4ADDR: 1314 if ((icmp6_nodeinfo & 2) == 0) 1315 goto bad; 1316 break; 1317 } 1318 1319 /* guess reply length */ 1320 switch (qtype) { 1321 case NI_QTYPE_NOOP: 1322 break; /* no reply data */ 1323 case NI_QTYPE_SUPTYPES: 1324 replylen += sizeof(u_int32_t); 1325 break; 1326 case NI_QTYPE_FQDN: 1327 /* XXX will append an mbuf */ 1328 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); 1329 break; 1330 case NI_QTYPE_NODEADDR: 1331 addrs = ni6_addrs(ni6, m, &ifp, subj); 1332 if ((replylen += addrs * (sizeof(struct in6_addr) + 1333 sizeof(u_int32_t))) > MCLBYTES) 1334 replylen = MCLBYTES; /* XXX: will truncate pkt later */ 1335 break; 1336 case NI_QTYPE_IPV4ADDR: 1337 /* unsupported - should respond with unknown Qtype? */ 1338 goto bad; 1339 default: 1340 /* 1341 * XXX: We must return a reply with the ICMP6 code 1342 * `unknown Qtype' in this case. However we regard the case 1343 * as an FQDN query for backward compatibility. 1344 * Older versions set a random value to this field, 1345 * so it rarely varies in the defined qtypes. 1346 * But the mechanism is not reliable... 1347 * maybe we should obsolete older versions. 1348 */ 1349 qtype = NI_QTYPE_FQDN; 1350 /* XXX will append an mbuf */ 1351 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); 1352 oldfqdn++; 1353 break; 1354 } 1355 1356 /* allocate an mbuf to reply. */ 1357 MGETHDR(n, M_DONTWAIT, m->m_type); 1358 if (n == NULL) { 1359 m_freem(m); 1360 return (NULL); 1361 } 1362 M_MOVE_PKTHDR(n, m); /* just for rcvif */ 1363 if (replylen > MHLEN) { 1364 if (replylen > MCLBYTES) { 1365 /* 1366 * XXX: should we try to allocate more? But MCLBYTES 1367 * is probably much larger than IPV6_MMTU... 1368 */ 1369 goto bad; 1370 } 1371 MCLGET(n, M_DONTWAIT); 1372 if ((n->m_flags & M_EXT) == 0) { 1373 goto bad; 1374 } 1375 } 1376 n->m_pkthdr.len = n->m_len = replylen; 1377 1378 /* copy mbuf header and IPv6 + Node Information base headers */ 1379 bcopy(mtod(m, void *), mtod(n, void *), sizeof(struct ip6_hdr)); 1380 nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1); 1381 bcopy((void *)ni6, (void *)nni6, sizeof(struct icmp6_nodeinfo)); 1382 1383 /* qtype dependent procedure */ 1384 switch (qtype) { 1385 case NI_QTYPE_NOOP: 1386 nni6->ni_code = ICMP6_NI_SUCCESS; 1387 nni6->ni_flags = 0; 1388 break; 1389 case NI_QTYPE_SUPTYPES: 1390 { 1391 u_int32_t v; 1392 nni6->ni_code = ICMP6_NI_SUCCESS; 1393 nni6->ni_flags = htons(0x0000); /* raw bitmap */ 1394 /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */ 1395 v = (u_int32_t)htonl(0x0000000f); 1396 bcopy(&v, nni6 + 1, sizeof(u_int32_t)); 1397 break; 1398 } 1399 case NI_QTYPE_FQDN: 1400 nni6->ni_code = ICMP6_NI_SUCCESS; 1401 fqdn = (struct ni_reply_fqdn *)(mtod(n, char *) + 1402 sizeof(struct ip6_hdr) + 1403 sizeof(struct icmp6_nodeinfo)); 1404 nni6->ni_flags = 0; /* XXX: meaningless TTL */ 1405 fqdn->ni_fqdn_ttl = 0; /* ditto. */ 1406 /* 1407 * XXX do we really have FQDN in variable "hostname"? 1408 */ 1409 n->m_next = ni6_nametodns(hostname, hostnamelen, oldfqdn); 1410 if (n->m_next == NULL) 1411 goto bad; 1412 /* XXX we assume that n->m_next is not a chain */ 1413 if (n->m_next->m_next != NULL) 1414 goto bad; 1415 n->m_pkthdr.len += n->m_next->m_len; 1416 break; 1417 case NI_QTYPE_NODEADDR: 1418 { 1419 int lenlim, copied; 1420 1421 nni6->ni_code = ICMP6_NI_SUCCESS; 1422 n->m_pkthdr.len = n->m_len = 1423 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); 1424 lenlim = M_TRAILINGSPACE(n); 1425 copied = ni6_store_addrs(ni6, nni6, ifp, lenlim); 1426 /* XXX: reset mbuf length */ 1427 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + 1428 sizeof(struct icmp6_nodeinfo) + copied; 1429 break; 1430 } 1431 default: 1432 break; /* XXX impossible! */ 1433 } 1434 1435 nni6->ni_type = ICMP6_NI_REPLY; 1436 m_freem(m); 1437 return (n); 1438 1439 bad: 1440 m_freem(m); 1441 if (n) 1442 m_freem(n); 1443 return (NULL); 1444 } 1445 #undef hostnamelen 1446 1447 #define isupper(x) ('A' <= (x) && (x) <= 'Z') 1448 #define isalpha(x) (('A' <= (x) && (x) <= 'Z') || ('a' <= (x) && (x) <= 'z')) 1449 #define isalnum(x) (isalpha(x) || ('0' <= (x) && (x) <= '9')) 1450 #define tolower(x) (isupper(x) ? (x) + 'a' - 'A' : (x)) 1451 1452 /* 1453 * make a mbuf with DNS-encoded string. no compression support. 1454 * 1455 * XXX names with less than 2 dots (like "foo" or "foo.section") will be 1456 * treated as truncated name (two \0 at the end). this is a wild guess. 1457 * 1458 * old - return pascal string if non-zero 1459 */ 1460 static struct mbuf * 1461 ni6_nametodns(const char *name, int namelen, int old) 1462 { 1463 struct mbuf *m; 1464 char *cp, *ep; 1465 const char *p, *q; 1466 int i, len, nterm; 1467 1468 if (old) 1469 len = namelen + 1; 1470 else 1471 len = MCLBYTES; 1472 1473 /* because MAXHOSTNAMELEN is usually 256, we use cluster mbuf */ 1474 MGET(m, M_DONTWAIT, MT_DATA); 1475 if (m && len > MLEN) { 1476 MCLGET(m, M_DONTWAIT); 1477 if ((m->m_flags & M_EXT) == 0) 1478 goto fail; 1479 } 1480 if (!m) 1481 goto fail; 1482 m->m_next = NULL; 1483 1484 if (old) { 1485 m->m_len = len; 1486 *mtod(m, char *) = namelen; 1487 bcopy(name, mtod(m, char *) + 1, namelen); 1488 return m; 1489 } else { 1490 m->m_len = 0; 1491 cp = mtod(m, char *); 1492 ep = mtod(m, char *) + M_TRAILINGSPACE(m); 1493 1494 /* if not certain about my name, return empty buffer */ 1495 if (namelen == 0) 1496 return m; 1497 1498 /* 1499 * guess if it looks like shortened hostname, or FQDN. 1500 * shortened hostname needs two trailing "\0". 1501 */ 1502 i = 0; 1503 for (p = name; p < name + namelen; p++) { 1504 if (*p && *p == '.') 1505 i++; 1506 } 1507 if (i < 2) 1508 nterm = 2; 1509 else 1510 nterm = 1; 1511 1512 p = name; 1513 while (cp < ep && p < name + namelen) { 1514 i = 0; 1515 for (q = p; q < name + namelen && *q && *q != '.'; q++) 1516 i++; 1517 /* result does not fit into mbuf */ 1518 if (cp + i + 1 >= ep) 1519 goto fail; 1520 /* 1521 * DNS label length restriction, RFC1035 page 8. 1522 * "i == 0" case is included here to avoid returning 1523 * 0-length label on "foo..bar". 1524 */ 1525 if (i <= 0 || i >= 64) 1526 goto fail; 1527 *cp++ = i; 1528 if (!isalpha(p[0]) || !isalnum(p[i - 1])) 1529 goto fail; 1530 while (i > 0) { 1531 if (!isalnum(*p) && *p != '-') 1532 goto fail; 1533 if (isupper(*p)) { 1534 *cp++ = tolower(*p); 1535 p++; 1536 } else 1537 *cp++ = *p++; 1538 i--; 1539 } 1540 p = q; 1541 if (p < name + namelen && *p == '.') 1542 p++; 1543 } 1544 /* termination */ 1545 if (cp + nterm >= ep) 1546 goto fail; 1547 while (nterm-- > 0) 1548 *cp++ = '\0'; 1549 m->m_len = cp - mtod(m, char *); 1550 return m; 1551 } 1552 1553 panic("should not reach here"); 1554 /* NOTREACHED */ 1555 1556 fail: 1557 if (m) 1558 m_freem(m); 1559 return NULL; 1560 } 1561 1562 /* 1563 * check if two DNS-encoded string matches. takes care of truncated 1564 * form (with \0\0 at the end). no compression support. 1565 * XXX upper/lowercase match (see RFC2065) 1566 */ 1567 static int 1568 ni6_dnsmatch(const char *a, int alen, const char *b, int blen) 1569 { 1570 const char *a0, *b0; 1571 int l; 1572 1573 /* simplest case - need validation? */ 1574 if (alen == blen && memcmp(a, b, alen) == 0) 1575 return 1; 1576 1577 a0 = a; 1578 b0 = b; 1579 1580 /* termination is mandatory */ 1581 if (alen < 2 || blen < 2) 1582 return 0; 1583 if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0') 1584 return 0; 1585 alen--; 1586 blen--; 1587 1588 while (a - a0 < alen && b - b0 < blen) { 1589 if (a - a0 + 1 > alen || b - b0 + 1 > blen) 1590 return 0; 1591 1592 if ((signed char)a[0] < 0 || (signed char)b[0] < 0) 1593 return 0; 1594 /* we don't support compression yet */ 1595 if (a[0] >= 64 || b[0] >= 64) 1596 return 0; 1597 1598 /* truncated case */ 1599 if (a[0] == 0 && a - a0 == alen - 1) 1600 return 1; 1601 if (b[0] == 0 && b - b0 == blen - 1) 1602 return 1; 1603 if (a[0] == 0 || b[0] == 0) 1604 return 0; 1605 1606 if (a[0] != b[0]) 1607 return 0; 1608 l = a[0]; 1609 if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen) 1610 return 0; 1611 if (memcmp(a + 1, b + 1, l) != 0) 1612 return 0; 1613 1614 a += 1 + l; 1615 b += 1 + l; 1616 } 1617 1618 if (a - a0 == alen && b - b0 == blen) 1619 return 1; 1620 else 1621 return 0; 1622 } 1623 1624 /* 1625 * calculate the number of addresses to be returned in the node info reply. 1626 */ 1627 static int 1628 ni6_addrs(struct icmp6_nodeinfo *ni6, struct mbuf *m, 1629 struct ifnet **ifpp, char *subj) 1630 { 1631 struct ifnet *ifp; 1632 struct in6_ifaddr *ifa6; 1633 struct ifaddr *ifa; 1634 struct sockaddr_in6 *subj_ip6 = NULL; /* XXX pedant */ 1635 int addrs = 0, addrsofif, iffound = 0; 1636 int niflags = ni6->ni_flags; 1637 1638 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) { 1639 switch (ni6->ni_code) { 1640 case ICMP6_NI_SUBJ_IPV6: 1641 if (subj == NULL) /* must be impossible... */ 1642 return (0); 1643 subj_ip6 = (struct sockaddr_in6 *)subj; 1644 break; 1645 default: 1646 /* 1647 * XXX: we only support IPv6 subject address for 1648 * this Qtype. 1649 */ 1650 return (0); 1651 } 1652 } 1653 1654 IFNET_READER_FOREACH(ifp) { 1655 addrsofif = 0; 1656 IFADDR_FOREACH(ifa, ifp) { 1657 if (ifa->ifa_addr->sa_family != AF_INET6) 1658 continue; 1659 ifa6 = (struct in6_ifaddr *)ifa; 1660 1661 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 && 1662 IN6_ARE_ADDR_EQUAL(&subj_ip6->sin6_addr, 1663 &ifa6->ia_addr.sin6_addr)) 1664 iffound = 1; 1665 1666 /* 1667 * IPv4-mapped addresses can only be returned by a 1668 * Node Information proxy, since they represent 1669 * addresses of IPv4-only nodes, which perforce do 1670 * not implement this protocol. 1671 * [icmp-name-lookups-07, Section 5.4] 1672 * So we don't support NI_NODEADDR_FLAG_COMPAT in 1673 * this function at this moment. 1674 */ 1675 1676 /* What do we have to do about ::1? */ 1677 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { 1678 case IPV6_ADDR_SCOPE_LINKLOCAL: 1679 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) 1680 continue; 1681 break; 1682 case IPV6_ADDR_SCOPE_SITELOCAL: 1683 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) 1684 continue; 1685 break; 1686 case IPV6_ADDR_SCOPE_GLOBAL: 1687 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) 1688 continue; 1689 break; 1690 default: 1691 continue; 1692 } 1693 1694 /* 1695 * check if anycast is okay. 1696 * XXX: just experimental. not in the spec. 1697 */ 1698 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && 1699 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) 1700 continue; /* we need only unicast addresses */ 1701 1702 addrsofif++; /* count the address */ 1703 } 1704 if (iffound) { 1705 *ifpp = ifp; 1706 return (addrsofif); 1707 } 1708 1709 addrs += addrsofif; 1710 } 1711 1712 return (addrs); 1713 } 1714 1715 static int 1716 ni6_store_addrs(struct icmp6_nodeinfo *ni6, 1717 struct icmp6_nodeinfo *nni6, struct ifnet *ifp0, 1718 int resid) 1719 { 1720 struct ifnet *ifp = ifp0 ? ifp0 : IFNET_READER_FIRST(); 1721 struct in6_ifaddr *ifa6; 1722 struct ifaddr *ifa; 1723 struct ifnet *ifp_dep = NULL; 1724 int copied = 0, allow_deprecated = 0; 1725 u_char *cp = (u_char *)(nni6 + 1); 1726 int niflags = ni6->ni_flags; 1727 u_int32_t ltime; 1728 1729 if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL)) 1730 return (0); /* needless to copy */ 1731 1732 again: 1733 1734 for (; ifp; ifp = IFNET_READER_NEXT(ifp)) 1735 { 1736 IFADDR_FOREACH(ifa, ifp) { 1737 if (ifa->ifa_addr->sa_family != AF_INET6) 1738 continue; 1739 ifa6 = (struct in6_ifaddr *)ifa; 1740 1741 if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 && 1742 allow_deprecated == 0) { 1743 /* 1744 * prefererred address should be put before 1745 * deprecated addresses. 1746 */ 1747 1748 /* record the interface for later search */ 1749 if (ifp_dep == NULL) 1750 ifp_dep = ifp; 1751 1752 continue; 1753 } 1754 else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 && 1755 allow_deprecated != 0) 1756 continue; /* we now collect deprecated addrs */ 1757 1758 /* What do we have to do about ::1? */ 1759 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { 1760 case IPV6_ADDR_SCOPE_LINKLOCAL: 1761 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) 1762 continue; 1763 break; 1764 case IPV6_ADDR_SCOPE_SITELOCAL: 1765 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) 1766 continue; 1767 break; 1768 case IPV6_ADDR_SCOPE_GLOBAL: 1769 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) 1770 continue; 1771 break; 1772 default: 1773 continue; 1774 } 1775 1776 /* 1777 * check if anycast is okay. 1778 * XXX: just experimental. not in the spec. 1779 */ 1780 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && 1781 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) 1782 continue; 1783 1784 /* now we can copy the address */ 1785 if (resid < sizeof(struct in6_addr) + 1786 sizeof(u_int32_t)) { 1787 /* 1788 * We give up much more copy. 1789 * Set the truncate flag and return. 1790 */ 1791 nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE; 1792 return (copied); 1793 } 1794 1795 /* 1796 * Set the TTL of the address. 1797 * The TTL value should be one of the following 1798 * according to the specification: 1799 * 1800 * 1. The remaining lifetime of a DHCP lease on the 1801 * address, or 1802 * 2. The remaining Valid Lifetime of a prefix from 1803 * which the address was derived through Stateless 1804 * Autoconfiguration. 1805 * 1806 * Note that we currently do not support stateful 1807 * address configuration by DHCPv6, so the former 1808 * case can't happen. 1809 * 1810 * TTL must be 2^31 > TTL >= 0. 1811 */ 1812 if (ifa6->ia6_lifetime.ia6t_expire == 0) 1813 ltime = ND6_INFINITE_LIFETIME; 1814 else { 1815 if (ifa6->ia6_lifetime.ia6t_expire > 1816 time_uptime) 1817 ltime = ifa6->ia6_lifetime.ia6t_expire - 1818 time_uptime; 1819 else 1820 ltime = 0; 1821 } 1822 if (ltime > 0x7fffffff) 1823 ltime = 0x7fffffff; 1824 ltime = htonl(ltime); 1825 1826 bcopy(<ime, cp, sizeof(u_int32_t)); 1827 cp += sizeof(u_int32_t); 1828 1829 /* copy the address itself */ 1830 bcopy(&ifa6->ia_addr.sin6_addr, cp, 1831 sizeof(struct in6_addr)); 1832 in6_clearscope((struct in6_addr *)cp); /* XXX */ 1833 cp += sizeof(struct in6_addr); 1834 1835 resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t)); 1836 copied += (sizeof(struct in6_addr) + sizeof(u_int32_t)); 1837 } 1838 if (ifp0) /* we need search only on the specified IF */ 1839 break; 1840 } 1841 1842 if (allow_deprecated == 0 && ifp_dep != NULL) { 1843 ifp = ifp_dep; 1844 allow_deprecated = 1; 1845 1846 goto again; 1847 } 1848 1849 return (copied); 1850 } 1851 1852 /* 1853 * XXX almost dup'ed code with rip6_input. 1854 */ 1855 static int 1856 icmp6_rip6_input(struct mbuf **mp, int off) 1857 { 1858 struct mbuf *m = *mp; 1859 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1860 struct inpcb_hdr *inph; 1861 struct in6pcb *in6p; 1862 struct in6pcb *last = NULL; 1863 struct sockaddr_in6 rip6src; 1864 struct icmp6_hdr *icmp6; 1865 struct mbuf *opts = NULL; 1866 1867 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6)); 1868 if (icmp6 == NULL) { 1869 /* m is already reclaimed */ 1870 return IPPROTO_DONE; 1871 } 1872 1873 /* 1874 * XXX: the address may have embedded scope zone ID, which should be 1875 * hidden from applications. 1876 */ 1877 sockaddr_in6_init(&rip6src, &ip6->ip6_src, 0, 0, 0); 1878 if (sa6_recoverscope(&rip6src)) { 1879 m_freem(m); 1880 return (IPPROTO_DONE); 1881 } 1882 1883 TAILQ_FOREACH(inph, &raw6cbtable.inpt_queue, inph_queue) { 1884 in6p = (struct in6pcb *)inph; 1885 if (in6p->in6p_af != AF_INET6) 1886 continue; 1887 if (in6p->in6p_ip6.ip6_nxt != IPPROTO_ICMPV6) 1888 continue; 1889 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) && 1890 !IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &ip6->ip6_dst)) 1891 continue; 1892 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr) && 1893 !IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src)) 1894 continue; 1895 if (in6p->in6p_icmp6filt 1896 && ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type, 1897 in6p->in6p_icmp6filt)) 1898 continue; 1899 if (last) { 1900 struct mbuf *n; 1901 if ((n = m_copy(m, 0, (int)M_COPYALL)) != NULL) { 1902 if (last->in6p_flags & IN6P_CONTROLOPTS) 1903 ip6_savecontrol(last, &opts, ip6, n); 1904 /* strip intermediate headers */ 1905 m_adj(n, off); 1906 if (sbappendaddr(&last->in6p_socket->so_rcv, 1907 (struct sockaddr *)&rip6src, 1908 n, opts) == 0) { 1909 /* should notify about lost packet */ 1910 m_freem(n); 1911 if (opts) 1912 m_freem(opts); 1913 } else 1914 sorwakeup(last->in6p_socket); 1915 opts = NULL; 1916 } 1917 } 1918 last = in6p; 1919 } 1920 if (last) { 1921 if (last->in6p_flags & IN6P_CONTROLOPTS) 1922 ip6_savecontrol(last, &opts, ip6, m); 1923 /* strip intermediate headers */ 1924 m_adj(m, off); 1925 if (sbappendaddr(&last->in6p_socket->so_rcv, 1926 (struct sockaddr *)&rip6src, m, opts) == 0) { 1927 m_freem(m); 1928 if (opts) 1929 m_freem(opts); 1930 } else 1931 sorwakeup(last->in6p_socket); 1932 } else { 1933 m_freem(m); 1934 IP6_STATDEC(IP6_STAT_DELIVERED); 1935 } 1936 return IPPROTO_DONE; 1937 } 1938 1939 /* 1940 * Reflect the ip6 packet back to the source. 1941 * OFF points to the icmp6 header, counted from the top of the mbuf. 1942 * 1943 * Note: RFC 1885 required that an echo reply should be truncated if it 1944 * did not fit in with (return) path MTU, and KAME code supported the 1945 * behavior. However, as a clarification after the RFC, this limitation 1946 * was removed in a revised version of the spec, RFC 2463. We had kept the 1947 * old behavior, with a (non-default) ifdef block, while the new version of 1948 * the spec was an internet-draft status, and even after the new RFC was 1949 * published. But it would rather make sense to clean the obsoleted part 1950 * up, and to make the code simpler at this stage. 1951 */ 1952 void 1953 icmp6_reflect(struct mbuf *m, size_t off) 1954 { 1955 struct ip6_hdr *ip6; 1956 struct icmp6_hdr *icmp6; 1957 const struct in6_ifaddr *ia; 1958 const struct ip6aux *ip6a; 1959 int plen; 1960 int type, code; 1961 struct ifnet *outif = NULL; 1962 struct in6_addr origdst; 1963 const struct in6_addr *src = NULL; 1964 1965 /* too short to reflect */ 1966 if (off < sizeof(struct ip6_hdr)) { 1967 nd6log(LOG_DEBUG, 1968 "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n", 1969 (u_long)off, (u_long)sizeof(struct ip6_hdr), 1970 __FILE__, __LINE__); 1971 goto bad; 1972 } 1973 1974 /* 1975 * If there are extra headers between IPv6 and ICMPv6, strip 1976 * off that header first. 1977 */ 1978 #ifdef DIAGNOSTIC 1979 if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN) 1980 panic("assumption failed in icmp6_reflect"); 1981 #endif 1982 if (off > sizeof(struct ip6_hdr)) { 1983 size_t l; 1984 struct ip6_hdr nip6; 1985 1986 l = off - sizeof(struct ip6_hdr); 1987 m_copydata(m, 0, sizeof(nip6), (void *)&nip6); 1988 m_adj(m, l); 1989 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 1990 if (m->m_len < l) { 1991 if ((m = m_pullup(m, l)) == NULL) 1992 return; 1993 } 1994 bcopy((void *)&nip6, mtod(m, void *), sizeof(nip6)); 1995 } else /* off == sizeof(struct ip6_hdr) */ { 1996 size_t l; 1997 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); 1998 if (m->m_len < l) { 1999 if ((m = m_pullup(m, l)) == NULL) 2000 return; 2001 } 2002 } 2003 plen = m->m_pkthdr.len - sizeof(struct ip6_hdr); 2004 ip6 = mtod(m, struct ip6_hdr *); 2005 ip6->ip6_nxt = IPPROTO_ICMPV6; 2006 icmp6 = (struct icmp6_hdr *)(ip6 + 1); 2007 type = icmp6->icmp6_type; /* keep type for statistics */ 2008 code = icmp6->icmp6_code; /* ditto. */ 2009 2010 origdst = ip6->ip6_dst; 2011 /* 2012 * ip6_input() drops a packet if its src is multicast. 2013 * So, the src is never multicast. 2014 */ 2015 ip6->ip6_dst = ip6->ip6_src; 2016 2017 /* 2018 * If the incoming packet was addressed directly to us (i.e. unicast), 2019 * use dst as the src for the reply. 2020 * The IN6_IFF_NOTREADY case should be VERY rare, but is possible 2021 * (for example) when we encounter an error while forwarding procedure 2022 * destined to a duplicated address of ours. 2023 * Note that ip6_getdstifaddr() may fail if we are in an error handling 2024 * procedure of an outgoing packet of our own, in which case we need 2025 * to search in the ifaddr list. 2026 */ 2027 if (IN6_IS_ADDR_MULTICAST(&origdst)) 2028 ; 2029 else if ((ip6a = ip6_getdstifaddr(m)) != NULL) { 2030 if ((ip6a->ip6a_flags & 2031 (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY)) == 0) 2032 src = &ip6a->ip6a_src; 2033 } else { 2034 union { 2035 struct sockaddr_in6 sin6; 2036 struct sockaddr sa; 2037 } u; 2038 2039 sockaddr_in6_init(&u.sin6, &origdst, 0, 0, 0); 2040 2041 ia = (struct in6_ifaddr *)ifa_ifwithaddr(&u.sa); 2042 2043 if (ia == NULL) 2044 ; 2045 else if ((ia->ia6_flags & 2046 (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY)) == 0) 2047 src = &ia->ia_addr.sin6_addr; 2048 } 2049 2050 if (src == NULL) { 2051 int e; 2052 struct sockaddr_in6 sin6; 2053 struct route ro; 2054 2055 /* 2056 * This case matches to multicasts, our anycast, or unicasts 2057 * that we do not own. Select a source address based on the 2058 * source address of the erroneous packet. 2059 */ 2060 /* zone ID should be embedded */ 2061 sockaddr_in6_init(&sin6, &ip6->ip6_dst, 0, 0, 0); 2062 2063 memset(&ro, 0, sizeof(ro)); 2064 src = in6_selectsrc(&sin6, NULL, NULL, &ro, NULL, NULL, &e); 2065 rtcache_free(&ro); 2066 if (src == NULL) { 2067 nd6log(LOG_DEBUG, 2068 "source can't be determined: " 2069 "dst=%s, error=%d\n", 2070 ip6_sprintf(&sin6.sin6_addr), e); 2071 goto bad; 2072 } 2073 } 2074 2075 ip6->ip6_src = *src; 2076 ip6->ip6_flow = 0; 2077 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2078 ip6->ip6_vfc |= IPV6_VERSION; 2079 ip6->ip6_nxt = IPPROTO_ICMPV6; 2080 if (m->m_pkthdr.rcvif) { 2081 /* XXX: This may not be the outgoing interface */ 2082 ip6->ip6_hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim; 2083 } else 2084 ip6->ip6_hlim = ip6_defhlim; 2085 2086 m->m_pkthdr.csum_flags = 0; 2087 icmp6->icmp6_cksum = 0; 2088 icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6, 2089 sizeof(struct ip6_hdr), plen); 2090 2091 /* 2092 * XXX option handling 2093 */ 2094 2095 m->m_flags &= ~(M_BCAST|M_MCAST); 2096 2097 /* 2098 * To avoid a "too big" situation at an intermediate router 2099 * and the path MTU discovery process, specify the IPV6_MINMTU flag. 2100 * Note that only echo and node information replies are affected, 2101 * since the length of ICMP6 errors is limited to the minimum MTU. 2102 */ 2103 if (ip6_output(m, NULL, NULL, IPV6_MINMTU, NULL, NULL, &outif) != 0 && 2104 outif) 2105 icmp6_ifstat_inc(outif, ifs6_out_error); 2106 2107 if (outif) 2108 icmp6_ifoutstat_inc(outif, type, code); 2109 2110 return; 2111 2112 bad: 2113 m_freem(m); 2114 return; 2115 } 2116 2117 static const char * 2118 icmp6_redirect_diag(struct in6_addr *src6, struct in6_addr *dst6, 2119 struct in6_addr *tgt6) 2120 { 2121 static char buf[1024]; 2122 snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)", 2123 ip6_sprintf(src6), ip6_sprintf(dst6), ip6_sprintf(tgt6)); 2124 return buf; 2125 } 2126 2127 void 2128 icmp6_redirect_input(struct mbuf *m, int off) 2129 { 2130 struct ifnet *ifp = m->m_pkthdr.rcvif; 2131 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 2132 struct nd_redirect *nd_rd; 2133 int icmp6len = ntohs(ip6->ip6_plen); 2134 char *lladdr = NULL; 2135 int lladdrlen = 0; 2136 struct rtentry *rt = NULL; 2137 int is_router; 2138 int is_onlink; 2139 struct in6_addr src6 = ip6->ip6_src; 2140 struct in6_addr redtgt6; 2141 struct in6_addr reddst6; 2142 union nd_opts ndopts; 2143 2144 if (ifp == NULL) 2145 goto freeit; 2146 2147 /* XXX if we are router, we don't update route by icmp6 redirect */ 2148 if (ip6_forwarding) 2149 goto freeit; 2150 if (!icmp6_rediraccept) 2151 goto freeit; 2152 2153 IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len); 2154 if (nd_rd == NULL) { 2155 ICMP6_STATINC(ICMP6_STAT_TOOSHORT); 2156 return; 2157 } 2158 redtgt6 = nd_rd->nd_rd_target; 2159 reddst6 = nd_rd->nd_rd_dst; 2160 2161 if (in6_setscope(&redtgt6, ifp, NULL) || 2162 in6_setscope(&reddst6, ifp, NULL)) { 2163 goto freeit; 2164 } 2165 2166 /* validation */ 2167 if (!IN6_IS_ADDR_LINKLOCAL(&src6)) { 2168 nd6log(LOG_ERR, 2169 "ICMP6 redirect sent from %s rejected; " 2170 "must be from linklocal\n", ip6_sprintf(&src6)); 2171 goto bad; 2172 } 2173 if (ip6->ip6_hlim != 255) { 2174 nd6log(LOG_ERR, 2175 "ICMP6 redirect sent from %s rejected; " 2176 "hlim=%d (must be 255)\n", 2177 ip6_sprintf(&src6), ip6->ip6_hlim); 2178 goto bad; 2179 } 2180 { 2181 /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */ 2182 struct sockaddr_in6 sin6; 2183 struct in6_addr *gw6; 2184 2185 sockaddr_in6_init(&sin6, &reddst6, 0, 0, 0); 2186 rt = rtalloc1((struct sockaddr *)&sin6, 0); 2187 if (rt) { 2188 if (rt->rt_gateway == NULL || 2189 rt->rt_gateway->sa_family != AF_INET6) { 2190 nd6log(LOG_ERR, 2191 "ICMP6 redirect rejected; no route " 2192 "with inet6 gateway found for redirect dst: %s\n", 2193 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)); 2194 rtfree(rt); 2195 goto bad; 2196 } 2197 2198 gw6 = &(((struct sockaddr_in6 *)rt->rt_gateway)->sin6_addr); 2199 if (memcmp(&src6, gw6, sizeof(struct in6_addr)) != 0) { 2200 nd6log(LOG_ERR, 2201 "ICMP6 redirect rejected; " 2202 "not equal to gw-for-src=%s (must be same): %s\n", 2203 ip6_sprintf(gw6), 2204 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)); 2205 rtfree(rt); 2206 goto bad; 2207 } 2208 } else { 2209 nd6log(LOG_ERR, "ICMP6 redirect rejected; " 2210 "no route found for redirect dst: %s\n", 2211 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)); 2212 goto bad; 2213 } 2214 rtfree(rt); 2215 rt = NULL; 2216 } 2217 if (IN6_IS_ADDR_MULTICAST(&reddst6)) { 2218 nd6log(LOG_ERR, "ICMP6 redirect rejected; " 2219 "redirect dst must be unicast: %s\n", 2220 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)); 2221 goto bad; 2222 } 2223 2224 is_router = is_onlink = 0; 2225 if (IN6_IS_ADDR_LINKLOCAL(&redtgt6)) 2226 is_router = 1; /* router case */ 2227 if (memcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0) 2228 is_onlink = 1; /* on-link destination case */ 2229 if (!is_router && !is_onlink) { 2230 nd6log(LOG_ERR, "ICMP6 redirect rejected; " 2231 "neither router case nor onlink case: %s\n", 2232 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)); 2233 goto bad; 2234 } 2235 /* validation passed */ 2236 2237 icmp6len -= sizeof(*nd_rd); 2238 nd6_option_init(nd_rd + 1, icmp6len, &ndopts); 2239 if (nd6_options(&ndopts) < 0) { 2240 nd6log(LOG_INFO, "invalid ND option, rejected: %s\n", 2241 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)); 2242 /* nd6_options have incremented stats */ 2243 goto freeit; 2244 } 2245 2246 if (ndopts.nd_opts_tgt_lladdr) { 2247 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 2248 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 2249 } 2250 2251 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 2252 nd6log(LOG_INFO, "lladdrlen mismatch for %s " 2253 "(if %d, icmp6 packet %d): %s\n", 2254 ip6_sprintf(&redtgt6), ifp->if_addrlen, lladdrlen - 2, 2255 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)); 2256 goto bad; 2257 } 2258 2259 /* RFC 2461 8.3 */ 2260 nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT, 2261 is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER); 2262 2263 if (!is_onlink) { /* better router case. perform rtredirect. */ 2264 /* perform rtredirect */ 2265 struct sockaddr_in6 sdst; 2266 struct sockaddr_in6 sgw; 2267 struct sockaddr_in6 ssrc; 2268 unsigned long rtcount; 2269 struct rtentry *newrt = NULL; 2270 2271 /* 2272 * do not install redirect route, if the number of entries 2273 * is too much (> hiwat). note that, the node (= host) will 2274 * work just fine even if we do not install redirect route 2275 * (there will be additional hops, though). 2276 */ 2277 rtcount = rt_timer_count(icmp6_redirect_timeout_q); 2278 if (0 <= ip6_maxdynroutes && rtcount >= ip6_maxdynroutes) 2279 goto freeit; 2280 if (0 <= icmp6_redirect_hiwat && rtcount > icmp6_redirect_hiwat) 2281 goto freeit; 2282 else if (0 <= icmp6_redirect_lowat && 2283 rtcount > icmp6_redirect_lowat) { 2284 /* 2285 * XXX nuke a victim, install the new one. 2286 */ 2287 } 2288 2289 memset(&sdst, 0, sizeof(sdst)); 2290 memset(&sgw, 0, sizeof(sgw)); 2291 memset(&ssrc, 0, sizeof(ssrc)); 2292 sdst.sin6_family = sgw.sin6_family = ssrc.sin6_family = AF_INET6; 2293 sdst.sin6_len = sgw.sin6_len = ssrc.sin6_len = 2294 sizeof(struct sockaddr_in6); 2295 bcopy(&redtgt6, &sgw.sin6_addr, sizeof(struct in6_addr)); 2296 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr)); 2297 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr)); 2298 rtredirect((struct sockaddr *)&sdst, (struct sockaddr *)&sgw, 2299 NULL, RTF_GATEWAY | RTF_HOST, 2300 (struct sockaddr *)&ssrc, 2301 &newrt); 2302 2303 if (newrt) { 2304 (void)rt_timer_add(newrt, icmp6_redirect_timeout, 2305 icmp6_redirect_timeout_q); 2306 rtfree(newrt); 2307 } 2308 } 2309 /* finally update cached route in each socket via pfctlinput */ 2310 { 2311 struct sockaddr_in6 sdst; 2312 2313 sockaddr_in6_init(&sdst, &reddst6, 0, 0, 0); 2314 pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst); 2315 #if defined(IPSEC) 2316 if (ipsec_used) 2317 key_sa_routechange((struct sockaddr *)&sdst); 2318 #endif 2319 } 2320 2321 freeit: 2322 m_freem(m); 2323 return; 2324 2325 bad: 2326 ICMP6_STATINC(ICMP6_STAT_BADREDIRECT); 2327 m_freem(m); 2328 } 2329 2330 void 2331 icmp6_redirect_output(struct mbuf *m0, struct rtentry *rt) 2332 { 2333 struct ifnet *ifp; /* my outgoing interface */ 2334 struct in6_addr *ifp_ll6; 2335 struct in6_addr *nexthop; 2336 struct ip6_hdr *sip6; /* m0 as struct ip6_hdr */ 2337 struct mbuf *m = NULL; /* newly allocated one */ 2338 struct ip6_hdr *ip6; /* m as struct ip6_hdr */ 2339 struct nd_redirect *nd_rd; 2340 size_t maxlen; 2341 u_char *p; 2342 struct sockaddr_in6 src_sa; 2343 2344 icmp6_errcount(ICMP6_STAT_OUTERRHIST, ND_REDIRECT, 0); 2345 2346 /* if we are not router, we don't send icmp6 redirect */ 2347 if (!ip6_forwarding) 2348 goto fail; 2349 2350 /* sanity check */ 2351 if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp)) 2352 goto fail; 2353 2354 /* 2355 * Address check: 2356 * the source address must identify a neighbor, and 2357 * the destination address must not be a multicast address 2358 * [RFC 2461, sec 8.2] 2359 */ 2360 sip6 = mtod(m0, struct ip6_hdr *); 2361 sockaddr_in6_init(&src_sa, &sip6->ip6_src, 0, 0, 0); 2362 if (nd6_is_addr_neighbor(&src_sa, ifp) == 0) 2363 goto fail; 2364 if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst)) 2365 goto fail; /* what should we do here? */ 2366 2367 /* rate limit */ 2368 if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0)) 2369 goto fail; 2370 2371 /* 2372 * Since we are going to append up to 1280 bytes (= IPV6_MMTU), 2373 * we almost always ask for an mbuf cluster for simplicity. 2374 * (MHLEN < IPV6_MMTU is almost always true) 2375 */ 2376 MGETHDR(m, M_DONTWAIT, MT_HEADER); 2377 if (m && IPV6_MMTU >= MHLEN) { 2378 #if IPV6_MMTU >= MCLBYTES 2379 _MCLGET(m, mcl_cache, IPV6_MMTU, M_DONTWAIT); 2380 #else 2381 MCLGET(m, M_DONTWAIT); 2382 #endif 2383 } 2384 2385 if (!m) 2386 goto fail; 2387 m->m_pkthdr.rcvif = NULL; 2388 m->m_len = 0; 2389 maxlen = M_TRAILINGSPACE(m); 2390 maxlen = min(IPV6_MMTU, maxlen); 2391 /* just for safety */ 2392 if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) + 2393 ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) { 2394 goto fail; 2395 } 2396 2397 { 2398 /* get ip6 linklocal address for ifp(my outgoing interface). */ 2399 struct in6_ifaddr *ia; 2400 if ((ia = in6ifa_ifpforlinklocal(ifp, 2401 IN6_IFF_NOTREADY| 2402 IN6_IFF_ANYCAST)) == NULL) 2403 goto fail; 2404 ifp_ll6 = &ia->ia_addr.sin6_addr; 2405 } 2406 2407 /* get ip6 linklocal address for the router. */ 2408 if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) { 2409 struct sockaddr_in6 *sin6; 2410 sin6 = (struct sockaddr_in6 *)rt->rt_gateway; 2411 nexthop = &sin6->sin6_addr; 2412 if (!IN6_IS_ADDR_LINKLOCAL(nexthop)) 2413 nexthop = NULL; 2414 } else 2415 nexthop = NULL; 2416 2417 /* ip6 */ 2418 ip6 = mtod(m, struct ip6_hdr *); 2419 ip6->ip6_flow = 0; 2420 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 2421 ip6->ip6_vfc |= IPV6_VERSION; 2422 /* ip6->ip6_plen will be set later */ 2423 ip6->ip6_nxt = IPPROTO_ICMPV6; 2424 ip6->ip6_hlim = 255; 2425 /* ip6->ip6_src must be linklocal addr for my outgoing if. */ 2426 bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr)); 2427 bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr)); 2428 2429 /* ND Redirect */ 2430 nd_rd = (struct nd_redirect *)(ip6 + 1); 2431 nd_rd->nd_rd_type = ND_REDIRECT; 2432 nd_rd->nd_rd_code = 0; 2433 nd_rd->nd_rd_reserved = 0; 2434 if (rt->rt_flags & RTF_GATEWAY) { 2435 /* 2436 * nd_rd->nd_rd_target must be a link-local address in 2437 * better router cases. 2438 */ 2439 if (!nexthop) 2440 goto fail; 2441 bcopy(nexthop, &nd_rd->nd_rd_target, 2442 sizeof(nd_rd->nd_rd_target)); 2443 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2444 sizeof(nd_rd->nd_rd_dst)); 2445 } else { 2446 /* make sure redtgt == reddst */ 2447 nexthop = &sip6->ip6_dst; 2448 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target, 2449 sizeof(nd_rd->nd_rd_target)); 2450 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, 2451 sizeof(nd_rd->nd_rd_dst)); 2452 } 2453 2454 p = (u_char *)(nd_rd + 1); 2455 2456 { 2457 /* target lladdr option */ 2458 struct llentry *ln = NULL; 2459 int len; 2460 struct nd_opt_hdr *nd_opt; 2461 char *lladdr; 2462 2463 ln = nd6_lookup(nexthop, ifp, false); 2464 if (ln == NULL) 2465 goto nolladdropt; 2466 len = sizeof(*nd_opt) + ifp->if_addrlen; 2467 len = (len + 7) & ~7; /* round by 8 */ 2468 /* safety check */ 2469 if (len + (p - (u_char *)ip6) > maxlen) { 2470 LLE_RUNLOCK(ln); 2471 goto nolladdropt; 2472 } 2473 if (ln->la_flags & LLE_VALID) { 2474 nd_opt = (struct nd_opt_hdr *)p; 2475 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 2476 nd_opt->nd_opt_len = len >> 3; 2477 lladdr = (char *)(nd_opt + 1); 2478 memcpy(lladdr, &ln->ll_addr, ifp->if_addrlen); 2479 p += len; 2480 } 2481 LLE_RUNLOCK(ln); 2482 } 2483 nolladdropt:; 2484 2485 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2486 2487 /* just to be safe */ 2488 if (m0->m_flags & M_DECRYPTED) 2489 goto noredhdropt; 2490 if (p - (u_char *)ip6 > maxlen) 2491 goto noredhdropt; 2492 2493 { 2494 /* redirected header option */ 2495 int len; 2496 struct nd_opt_rd_hdr *nd_opt_rh; 2497 2498 /* 2499 * compute the maximum size for icmp6 redirect header option. 2500 * XXX room for auth header? 2501 */ 2502 len = maxlen - (p - (u_char *)ip6); 2503 len &= ~7; 2504 2505 /* 2506 * Redirected header option spec (RFC2461 4.6.3) talks nothing 2507 * about padding/truncate rule for the original IP packet. 2508 * From the discussion on IPv6imp in Feb 1999, 2509 * the consensus was: 2510 * - "attach as much as possible" is the goal 2511 * - pad if not aligned (original size can be guessed by 2512 * original ip6 header) 2513 * Following code adds the padding if it is simple enough, 2514 * and truncates if not. 2515 */ 2516 if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) { 2517 /* not enough room, truncate */ 2518 m_adj(m0, (len - sizeof(*nd_opt_rh)) - 2519 m0->m_pkthdr.len); 2520 } else { 2521 /* 2522 * enough room, truncate if not aligned. 2523 * we don't pad here for simplicity. 2524 */ 2525 size_t extra; 2526 2527 extra = m0->m_pkthdr.len % 8; 2528 if (extra) { 2529 /* truncate */ 2530 m_adj(m0, -extra); 2531 } 2532 len = m0->m_pkthdr.len + sizeof(*nd_opt_rh); 2533 } 2534 2535 nd_opt_rh = (struct nd_opt_rd_hdr *)p; 2536 memset(nd_opt_rh, 0, sizeof(*nd_opt_rh)); 2537 nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER; 2538 nd_opt_rh->nd_opt_rh_len = len >> 3; 2539 p += sizeof(*nd_opt_rh); 2540 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; 2541 2542 /* connect m0 to m */ 2543 m->m_pkthdr.len += m0->m_pkthdr.len; 2544 m_cat(m, m0); 2545 m0 = NULL; 2546 } 2547 noredhdropt: 2548 if (m0) { 2549 m_freem(m0); 2550 m0 = NULL; 2551 } 2552 2553 /* XXX: clear embedded link IDs in the inner header */ 2554 in6_clearscope(&sip6->ip6_src); 2555 in6_clearscope(&sip6->ip6_dst); 2556 in6_clearscope(&nd_rd->nd_rd_target); 2557 in6_clearscope(&nd_rd->nd_rd_dst); 2558 2559 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr)); 2560 2561 nd_rd->nd_rd_cksum = 0; 2562 nd_rd->nd_rd_cksum 2563 = in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), ntohs(ip6->ip6_plen)); 2564 2565 /* send the packet to outside... */ 2566 if (ip6_output(m, NULL, NULL, 0, NULL, NULL, NULL) != 0) 2567 icmp6_ifstat_inc(ifp, ifs6_out_error); 2568 2569 icmp6_ifstat_inc(ifp, ifs6_out_msg); 2570 icmp6_ifstat_inc(ifp, ifs6_out_redirect); 2571 ICMP6_STATINC(ICMP6_STAT_OUTHIST + ND_REDIRECT); 2572 2573 return; 2574 2575 fail: 2576 if (m) 2577 m_freem(m); 2578 if (m0) 2579 m_freem(m0); 2580 } 2581 2582 /* 2583 * ICMPv6 socket option processing. 2584 */ 2585 int 2586 icmp6_ctloutput(int op, struct socket *so, struct sockopt *sopt) 2587 { 2588 int error = 0; 2589 struct in6pcb *in6p = sotoin6pcb(so); 2590 2591 if (sopt->sopt_level != IPPROTO_ICMPV6) 2592 return rip6_ctloutput(op, so, sopt); 2593 2594 switch (op) { 2595 case PRCO_SETOPT: 2596 switch (sopt->sopt_name) { 2597 case ICMP6_FILTER: 2598 { 2599 struct icmp6_filter fil; 2600 2601 error = sockopt_get(sopt, &fil, sizeof(fil)); 2602 if (error) 2603 break; 2604 memcpy(in6p->in6p_icmp6filt, &fil, 2605 sizeof(struct icmp6_filter)); 2606 error = 0; 2607 break; 2608 } 2609 2610 default: 2611 error = ENOPROTOOPT; 2612 break; 2613 } 2614 break; 2615 2616 case PRCO_GETOPT: 2617 switch (sopt->sopt_name) { 2618 case ICMP6_FILTER: 2619 { 2620 if (in6p->in6p_icmp6filt == NULL) { 2621 error = EINVAL; 2622 break; 2623 } 2624 error = sockopt_set(sopt, in6p->in6p_icmp6filt, 2625 sizeof(struct icmp6_filter)); 2626 break; 2627 } 2628 2629 default: 2630 error = ENOPROTOOPT; 2631 break; 2632 } 2633 break; 2634 } 2635 2636 return (error); 2637 } 2638 2639 /* 2640 * Perform rate limit check. 2641 * Returns 0 if it is okay to send the icmp6 packet. 2642 * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate 2643 * limitation. 2644 * 2645 * XXX per-destination/type check necessary? 2646 */ 2647 static int 2648 icmp6_ratelimit( 2649 const struct in6_addr *dst, /* not used at this moment */ 2650 const int type, /* not used at this moment */ 2651 const int code) /* not used at this moment */ 2652 { 2653 int ret; 2654 2655 ret = 0; /* okay to send */ 2656 2657 /* PPS limit */ 2658 if (!ppsratecheck(&icmp6errppslim_last, &icmp6errpps_count, 2659 icmp6errppslim)) { 2660 /* The packet is subject to rate limit */ 2661 ret++; 2662 } 2663 2664 return ret; 2665 } 2666 2667 static struct rtentry * 2668 icmp6_mtudisc_clone(struct sockaddr *dst) 2669 { 2670 struct rtentry *rt; 2671 int error; 2672 2673 rt = rtalloc1(dst, 1); 2674 if (rt == 0) 2675 return NULL; 2676 2677 /* If we didn't get a host route, allocate one */ 2678 if ((rt->rt_flags & RTF_HOST) == 0) { 2679 struct rtentry *nrt; 2680 2681 error = rtrequest(RTM_ADD, dst, rt->rt_gateway, NULL, 2682 RTF_GATEWAY | RTF_HOST | RTF_DYNAMIC, &nrt); 2683 if (error) { 2684 rtfree(rt); 2685 return NULL; 2686 } 2687 nrt->rt_rmx = rt->rt_rmx; 2688 rtfree(rt); 2689 rt = nrt; 2690 } 2691 error = rt_timer_add(rt, icmp6_mtudisc_timeout, 2692 icmp6_mtudisc_timeout_q); 2693 if (error) { 2694 rtfree(rt); 2695 return NULL; 2696 } 2697 2698 return rt; /* caller need to call rtfree() */ 2699 } 2700 2701 static void 2702 icmp6_mtudisc_timeout(struct rtentry *rt, struct rttimer *r) 2703 { 2704 2705 KASSERT(rt != NULL); 2706 rt_assert_referenced(rt); 2707 2708 if ((rt->rt_flags & (RTF_DYNAMIC | RTF_HOST)) == 2709 (RTF_DYNAMIC | RTF_HOST)) { 2710 rtrequest(RTM_DELETE, rt_getkey(rt), 2711 rt->rt_gateway, rt_mask(rt), rt->rt_flags, NULL); 2712 } else { 2713 if (!(rt->rt_rmx.rmx_locks & RTV_MTU)) 2714 rt->rt_rmx.rmx_mtu = 0; 2715 } 2716 } 2717 2718 static void 2719 icmp6_redirect_timeout(struct rtentry *rt, struct rttimer *r) 2720 { 2721 2722 KASSERT(rt != NULL); 2723 rt_assert_referenced(rt); 2724 2725 if ((rt->rt_flags & (RTF_GATEWAY | RTF_DYNAMIC | RTF_HOST)) == 2726 (RTF_GATEWAY | RTF_DYNAMIC | RTF_HOST)) { 2727 rtrequest(RTM_DELETE, rt_getkey(rt), 2728 rt->rt_gateway, rt_mask(rt), rt->rt_flags, NULL); 2729 } 2730 } 2731 2732 /* 2733 * sysctl helper routine for the net.inet6.icmp6.nd6 nodes. silly? 2734 */ 2735 static int 2736 sysctl_net_inet6_icmp6_nd6(SYSCTLFN_ARGS) 2737 { 2738 (void)&name; 2739 (void)&l; 2740 (void)&oname; 2741 2742 if (namelen != 0) 2743 return (EINVAL); 2744 2745 return (nd6_sysctl(rnode->sysctl_num, oldp, oldlenp, 2746 /*XXXUNCONST*/ 2747 __UNCONST(newp), newlen)); 2748 } 2749 2750 static int 2751 sysctl_net_inet6_icmp6_stats(SYSCTLFN_ARGS) 2752 { 2753 2754 return (NETSTAT_SYSCTL(icmp6stat_percpu, ICMP6_NSTATS)); 2755 } 2756 2757 static int 2758 sysctl_net_inet6_icmp6_redirtimeout(SYSCTLFN_ARGS) 2759 { 2760 int error, tmp; 2761 struct sysctlnode node; 2762 2763 node = *rnode; 2764 node.sysctl_data = &tmp; 2765 tmp = icmp6_redirtimeout; 2766 error = sysctl_lookup(SYSCTLFN_CALL(&node)); 2767 if (error || newp == NULL) 2768 return error; 2769 if (tmp < 0) 2770 return EINVAL; 2771 icmp6_redirtimeout = tmp; 2772 2773 if (icmp6_redirect_timeout_q != NULL) { 2774 if (icmp6_redirtimeout == 0) { 2775 rt_timer_queue_destroy(icmp6_redirect_timeout_q, 2776 true); 2777 } else { 2778 rt_timer_queue_change(icmp6_redirect_timeout_q, 2779 icmp6_redirtimeout); 2780 } 2781 } else if (icmp6_redirtimeout > 0) { 2782 icmp6_redirect_timeout_q = 2783 rt_timer_queue_create(icmp6_redirtimeout); 2784 } 2785 2786 return 0; 2787 } 2788 2789 static void 2790 sysctl_net_inet6_icmp6_setup(struct sysctllog **clog) 2791 { 2792 extern int nd6_maxqueuelen; /* defined in nd6.c */ 2793 2794 sysctl_createv(clog, 0, NULL, NULL, 2795 CTLFLAG_PERMANENT, 2796 CTLTYPE_NODE, "inet6", NULL, 2797 NULL, 0, NULL, 0, 2798 CTL_NET, PF_INET6, CTL_EOL); 2799 sysctl_createv(clog, 0, NULL, NULL, 2800 CTLFLAG_PERMANENT, 2801 CTLTYPE_NODE, "icmp6", 2802 SYSCTL_DESCR("ICMPv6 related settings"), 2803 NULL, 0, NULL, 0, 2804 CTL_NET, PF_INET6, IPPROTO_ICMPV6, CTL_EOL); 2805 2806 sysctl_createv(clog, 0, NULL, NULL, 2807 CTLFLAG_PERMANENT, 2808 CTLTYPE_STRUCT, "stats", 2809 SYSCTL_DESCR("ICMPv6 transmission statistics"), 2810 sysctl_net_inet6_icmp6_stats, 0, NULL, 0, 2811 CTL_NET, PF_INET6, IPPROTO_ICMPV6, 2812 ICMPV6CTL_STATS, CTL_EOL); 2813 sysctl_createv(clog, 0, NULL, NULL, 2814 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2815 CTLTYPE_INT, "rediraccept", 2816 SYSCTL_DESCR("Accept and process redirect messages"), 2817 NULL, 0, &icmp6_rediraccept, 0, 2818 CTL_NET, PF_INET6, IPPROTO_ICMPV6, 2819 ICMPV6CTL_REDIRACCEPT, CTL_EOL); 2820 sysctl_createv(clog, 0, NULL, NULL, 2821 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2822 CTLTYPE_INT, "redirtimeout", 2823 SYSCTL_DESCR("Redirect generated route lifetime"), 2824 sysctl_net_inet6_icmp6_redirtimeout, 0, 2825 &icmp6_redirtimeout, 0, 2826 CTL_NET, PF_INET6, IPPROTO_ICMPV6, 2827 ICMPV6CTL_REDIRTIMEOUT, CTL_EOL); 2828 #if 0 /* obsoleted */ 2829 sysctl_createv(clog, 0, NULL, NULL, 2830 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2831 CTLTYPE_INT, "errratelimit", NULL, 2832 NULL, 0, &icmp6_errratelimit, 0, 2833 CTL_NET, PF_INET6, IPPROTO_ICMPV6, 2834 ICMPV6CTL_ERRRATELIMIT, CTL_EOL); 2835 #endif 2836 sysctl_createv(clog, 0, NULL, NULL, 2837 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2838 CTLTYPE_INT, "nd6_prune", 2839 SYSCTL_DESCR("Neighbor discovery prune interval"), 2840 NULL, 0, &nd6_prune, 0, 2841 CTL_NET, PF_INET6, IPPROTO_ICMPV6, 2842 ICMPV6CTL_ND6_PRUNE, CTL_EOL); 2843 sysctl_createv(clog, 0, NULL, NULL, 2844 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2845 CTLTYPE_INT, "nd6_delay", 2846 SYSCTL_DESCR("First probe delay time"), 2847 NULL, 0, &nd6_delay, 0, 2848 CTL_NET, PF_INET6, IPPROTO_ICMPV6, 2849 ICMPV6CTL_ND6_DELAY, CTL_EOL); 2850 sysctl_createv(clog, 0, NULL, NULL, 2851 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2852 CTLTYPE_INT, "nd6_umaxtries", 2853 SYSCTL_DESCR("Number of unicast discovery attempts"), 2854 NULL, 0, &nd6_umaxtries, 0, 2855 CTL_NET, PF_INET6, IPPROTO_ICMPV6, 2856 ICMPV6CTL_ND6_UMAXTRIES, CTL_EOL); 2857 sysctl_createv(clog, 0, NULL, NULL, 2858 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2859 CTLTYPE_INT, "nd6_mmaxtries", 2860 SYSCTL_DESCR("Number of multicast discovery attempts"), 2861 NULL, 0, &nd6_mmaxtries, 0, 2862 CTL_NET, PF_INET6, IPPROTO_ICMPV6, 2863 ICMPV6CTL_ND6_MMAXTRIES, CTL_EOL); 2864 sysctl_createv(clog, 0, NULL, NULL, 2865 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2866 CTLTYPE_INT, "nd6_useloopback", 2867 SYSCTL_DESCR("Use loopback interface for local traffic"), 2868 NULL, 0, &nd6_useloopback, 0, 2869 CTL_NET, PF_INET6, IPPROTO_ICMPV6, 2870 ICMPV6CTL_ND6_USELOOPBACK, CTL_EOL); 2871 #if 0 /* obsoleted */ 2872 sysctl_createv(clog, 0, NULL, NULL, 2873 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2874 CTLTYPE_INT, "nd6_proxyall", NULL, 2875 NULL, 0, &nd6_proxyall, 0, 2876 CTL_NET, PF_INET6, IPPROTO_ICMPV6, 2877 ICMPV6CTL_ND6_PROXYALL, CTL_EOL); 2878 #endif 2879 sysctl_createv(clog, 0, NULL, NULL, 2880 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2881 CTLTYPE_INT, "nodeinfo", 2882 SYSCTL_DESCR("Respond to node information requests"), 2883 NULL, 0, &icmp6_nodeinfo, 0, 2884 CTL_NET, PF_INET6, IPPROTO_ICMPV6, 2885 ICMPV6CTL_NODEINFO, CTL_EOL); 2886 sysctl_createv(clog, 0, NULL, NULL, 2887 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2888 CTLTYPE_INT, "errppslimit", 2889 SYSCTL_DESCR("Maximum ICMP errors sent per second"), 2890 NULL, 0, &icmp6errppslim, 0, 2891 CTL_NET, PF_INET6, IPPROTO_ICMPV6, 2892 ICMPV6CTL_ERRPPSLIMIT, CTL_EOL); 2893 sysctl_createv(clog, 0, NULL, NULL, 2894 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2895 CTLTYPE_INT, "nd6_maxnudhint", 2896 SYSCTL_DESCR("Maximum neighbor unreachable hint count"), 2897 NULL, 0, &nd6_maxnudhint, 0, 2898 CTL_NET, PF_INET6, IPPROTO_ICMPV6, 2899 ICMPV6CTL_ND6_MAXNUDHINT, CTL_EOL); 2900 sysctl_createv(clog, 0, NULL, NULL, 2901 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2902 CTLTYPE_INT, "mtudisc_hiwat", 2903 SYSCTL_DESCR("Low mark on MTU Discovery route timers"), 2904 NULL, 0, &icmp6_mtudisc_hiwat, 0, 2905 CTL_NET, PF_INET6, IPPROTO_ICMPV6, 2906 ICMPV6CTL_MTUDISC_HIWAT, CTL_EOL); 2907 sysctl_createv(clog, 0, NULL, NULL, 2908 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2909 CTLTYPE_INT, "mtudisc_lowat", 2910 SYSCTL_DESCR("Low mark on MTU Discovery route timers"), 2911 NULL, 0, &icmp6_mtudisc_lowat, 0, 2912 CTL_NET, PF_INET6, IPPROTO_ICMPV6, 2913 ICMPV6CTL_MTUDISC_LOWAT, CTL_EOL); 2914 sysctl_createv(clog, 0, NULL, NULL, 2915 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2916 CTLTYPE_INT, "nd6_debug", 2917 SYSCTL_DESCR("Enable neighbor discovery debug output"), 2918 NULL, 0, &nd6_debug, 0, 2919 CTL_NET, PF_INET6, IPPROTO_ICMPV6, 2920 ICMPV6CTL_ND6_DEBUG, CTL_EOL); 2921 sysctl_createv(clog, 0, NULL, NULL, 2922 CTLFLAG_PERMANENT, 2923 CTLTYPE_STRUCT, "nd6_drlist", 2924 SYSCTL_DESCR("Default router list"), 2925 sysctl_net_inet6_icmp6_nd6, 0, NULL, 0, 2926 CTL_NET, PF_INET6, IPPROTO_ICMPV6, 2927 ICMPV6CTL_ND6_DRLIST, CTL_EOL); 2928 sysctl_createv(clog, 0, NULL, NULL, 2929 CTLFLAG_PERMANENT, 2930 CTLTYPE_STRUCT, "nd6_prlist", 2931 SYSCTL_DESCR("Prefix list"), 2932 sysctl_net_inet6_icmp6_nd6, 0, NULL, 0, 2933 CTL_NET, PF_INET6, IPPROTO_ICMPV6, 2934 ICMPV6CTL_ND6_PRLIST, CTL_EOL); 2935 sysctl_createv(clog, 0, NULL, NULL, 2936 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2937 CTLTYPE_INT, "maxqueuelen", 2938 SYSCTL_DESCR("max packet queue len for a unresolved ND"), 2939 NULL, 1, &nd6_maxqueuelen, 0, 2940 CTL_NET, PF_INET6, IPPROTO_ICMPV6, 2941 ICMPV6CTL_ND6_MAXQLEN, CTL_EOL); 2942 } 2943 2944 void 2945 icmp6_statinc(u_int stat) 2946 { 2947 2948 KASSERT(stat < ICMP6_NSTATS); 2949 ICMP6_STATINC(stat); 2950 } 2951