1 /* $KAME: rtsol.c,v 1.27 2003/10/05 00:09:36 itojun Exp $ */ 2 3 /*- 4 * SPDX-License-Identifier: BSD-3-Clause 5 * 6 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 7 * Copyright (C) 2011 Hiroki Sato 8 * All rights reserved. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the project nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * $FreeBSD$ 35 */ 36 37 #include <sys/param.h> 38 #include <sys/capsicum.h> 39 #include <sys/queue.h> 40 #include <sys/socket.h> 41 #include <sys/stat.h> 42 #include <sys/uio.h> 43 #include <sys/wait.h> 44 45 #include <net/if.h> 46 #include <net/route.h> 47 #include <net/if_dl.h> 48 49 #define __BSD_VISIBLE 1 /* IN6ADDR_LINKLOCAL_ALLROUTERS_INIT */ 50 #include <netinet/in.h> 51 #undef __BSD_VISIBLE 52 #include <netinet/ip6.h> 53 #include <netinet6/ip6_var.h> 54 #include <netinet/icmp6.h> 55 56 #include <arpa/inet.h> 57 58 #include <capsicum_helpers.h> 59 #include <netdb.h> 60 #include <time.h> 61 #include <fcntl.h> 62 #include <unistd.h> 63 #include <stdio.h> 64 #include <time.h> 65 #include <err.h> 66 #include <errno.h> 67 #include <string.h> 68 #include <stdlib.h> 69 #include <syslog.h> 70 #include "rtsold.h" 71 72 static char rsid[IFNAMSIZ + 1 + sizeof(DNSINFO_ORIGIN_LABEL) + 1 + NI_MAXHOST]; 73 struct ifinfo_head_t ifinfo_head = TAILQ_HEAD_INITIALIZER(ifinfo_head); 74 75 static void call_script(const char *const *, struct script_msg_head_t *); 76 static size_t dname_labeldec(char *, size_t, const char *); 77 static struct ra_opt *find_raopt(struct rainfo *, int, void *, size_t); 78 static int ra_opt_rdnss_dispatch(struct ifinfo *, struct rainfo *, 79 struct script_msg_head_t *, struct script_msg_head_t *); 80 static char *make_rsid(const char *, const char *, struct rainfo *); 81 82 #define _ARGS_MANAGED managedconf_script, ifi->ifname, rasender 83 #define _ARGS_OTHER otherconf_script, ifi->ifname, rasender 84 #define _ARGS_ALWAYS alwaysconf_script, ifi->ifname, rasender 85 #define _ARGS_RESADD resolvconf_script, "-a", rsid 86 #define _ARGS_RESDEL resolvconf_script, "-d", rsid 87 88 #define CALL_SCRIPT(name, sm_head) do { \ 89 const char *const sarg[] = { _ARGS_##name, NULL }; \ 90 call_script(sarg, sm_head); \ 91 } while (0) 92 93 #define ELM_MALLOC(p, error_action) do { \ 94 p = malloc(sizeof(*p)); \ 95 if (p == NULL) { \ 96 warnmsg(LOG_ERR, __func__, "malloc failed: %s", \ 97 strerror(errno)); \ 98 error_action; \ 99 } \ 100 memset(p, 0, sizeof(*p)); \ 101 } while (0) 102 103 int 104 recvsockopen(void) 105 { 106 struct icmp6_filter filt; 107 cap_rights_t rights; 108 int on, sock; 109 110 if ((sock = socket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6)) < 0) { 111 warnmsg(LOG_ERR, __func__, "socket: %s", strerror(errno)); 112 goto fail; 113 } 114 115 /* Provide info about the receiving interface. */ 116 on = 1; 117 if (setsockopt(sock, IPPROTO_IPV6, IPV6_RECVPKTINFO, &on, 118 sizeof(on)) < 0) { 119 warnmsg(LOG_ERR, __func__, "setsockopt(IPV6_RECVPKTINFO): %s", 120 strerror(errno)); 121 goto fail; 122 } 123 124 /* Include the hop limit from the received header. */ 125 on = 1; 126 if (setsockopt(sock, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &on, 127 sizeof(on)) < 0) { 128 warnmsg(LOG_ERR, __func__, "setsockopt(IPV6_RECVHOPLIMIT): %s", 129 strerror(errno)); 130 goto fail; 131 } 132 133 /* Filter out everything except for Router Advertisements. */ 134 ICMP6_FILTER_SETBLOCKALL(&filt); 135 ICMP6_FILTER_SETPASS(ND_ROUTER_ADVERT, &filt); 136 if (setsockopt(sock, IPPROTO_ICMPV6, ICMP6_FILTER, &filt, 137 sizeof(filt)) == -1) { 138 warnmsg(LOG_ERR, __func__, "setsockopt(ICMP6_FILTER): %s", 139 strerror(errno)); 140 goto fail; 141 } 142 143 cap_rights_init(&rights, CAP_EVENT, CAP_RECV); 144 if (caph_rights_limit(sock, &rights) < 0) { 145 warnmsg(LOG_ERR, __func__, "caph_rights_limit(): %s", 146 strerror(errno)); 147 goto fail; 148 } 149 150 return (sock); 151 152 fail: 153 if (sock >= 0) 154 (void)close(sock); 155 return (-1); 156 } 157 158 void 159 rtsol_input(int sock) 160 { 161 uint8_t cmsg[CMSG_SPACE(sizeof(struct in6_pktinfo)) + 162 CMSG_SPACE(sizeof(int))]; 163 struct iovec iov; 164 struct msghdr hdr; 165 struct sockaddr_in6 from; 166 char answer[1500], ntopbuf[INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ]; 167 int l, ifindex = 0, *hlimp = NULL; 168 ssize_t msglen; 169 struct in6_pktinfo *pi = NULL; 170 struct ifinfo *ifi = NULL; 171 struct ra_opt *rao = NULL; 172 struct icmp6_hdr *icp; 173 struct nd_router_advert *nd_ra; 174 struct cmsghdr *cm; 175 struct rainfo *rai; 176 char *p, *raoptp; 177 struct in6_addr *addr; 178 struct nd_opt_hdr *ndo; 179 struct nd_opt_rdnss *rdnss; 180 struct nd_opt_dnssl *dnssl; 181 size_t len; 182 char nsbuf[INET6_ADDRSTRLEN + 1 + IFNAMSIZ + 1]; 183 char dname[NI_MAXHOST]; 184 struct timespec lifetime, now; 185 int newent_rai, newent_rao; 186 187 memset(&hdr, 0, sizeof(hdr)); 188 hdr.msg_iov = &iov; 189 hdr.msg_iovlen = 1; 190 hdr.msg_name = &from; 191 hdr.msg_namelen = sizeof(from); 192 hdr.msg_control = cmsg; 193 hdr.msg_controllen = sizeof(cmsg); 194 195 iov.iov_base = (caddr_t)answer; 196 iov.iov_len = sizeof(answer); 197 198 if ((msglen = recvmsg(sock, &hdr, 0)) < 0) { 199 warnmsg(LOG_ERR, __func__, "recvmsg: %s", strerror(errno)); 200 return; 201 } 202 203 /* Extract control message info. */ 204 for (cm = (struct cmsghdr *)CMSG_FIRSTHDR(&hdr); cm != NULL; 205 cm = (struct cmsghdr *)CMSG_NXTHDR(&hdr, cm)) { 206 if (cm->cmsg_level == IPPROTO_IPV6 && 207 cm->cmsg_type == IPV6_PKTINFO && 208 cm->cmsg_len == CMSG_LEN(sizeof(struct in6_pktinfo))) { 209 pi = (struct in6_pktinfo *)(void *)(CMSG_DATA(cm)); 210 ifindex = pi->ipi6_ifindex; 211 } 212 if (cm->cmsg_level == IPPROTO_IPV6 && 213 cm->cmsg_type == IPV6_HOPLIMIT && 214 cm->cmsg_len == CMSG_LEN(sizeof(int))) 215 hlimp = (int *)(void *)CMSG_DATA(cm); 216 } 217 218 if (ifindex == 0) { 219 warnmsg(LOG_ERR, __func__, 220 "failed to get receiving interface"); 221 return; 222 } 223 if (hlimp == NULL) { 224 warnmsg(LOG_ERR, __func__, 225 "failed to get receiving hop limit"); 226 return; 227 } 228 229 if ((size_t)msglen < sizeof(struct nd_router_advert)) { 230 warnmsg(LOG_INFO, __func__, 231 "packet size(%zd) is too short", msglen); 232 return; 233 } 234 235 icp = (struct icmp6_hdr *)iov.iov_base; 236 if (icp->icmp6_type != ND_ROUTER_ADVERT) { 237 /* 238 * this should not happen because we configured a filter 239 * that only passes RAs on the receiving socket. 240 */ 241 warnmsg(LOG_ERR, __func__, 242 "invalid icmp type(%d) from %s on %s", icp->icmp6_type, 243 inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf, 244 sizeof(ntopbuf)), 245 if_indextoname(pi->ipi6_ifindex, ifnamebuf)); 246 return; 247 } 248 249 if (icp->icmp6_code != 0) { 250 warnmsg(LOG_INFO, __func__, 251 "invalid icmp code(%d) from %s on %s", icp->icmp6_code, 252 inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf, 253 sizeof(ntopbuf)), 254 if_indextoname(pi->ipi6_ifindex, ifnamebuf)); 255 return; 256 } 257 258 if (*hlimp != 255) { 259 warnmsg(LOG_INFO, __func__, 260 "invalid RA with hop limit(%d) from %s on %s", 261 *hlimp, 262 inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf, 263 sizeof(ntopbuf)), 264 if_indextoname(pi->ipi6_ifindex, ifnamebuf)); 265 return; 266 } 267 268 if (pi && !IN6_IS_ADDR_LINKLOCAL(&from.sin6_addr)) { 269 warnmsg(LOG_INFO, __func__, 270 "invalid RA with non link-local source from %s on %s", 271 inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf, 272 sizeof(ntopbuf)), 273 if_indextoname(pi->ipi6_ifindex, ifnamebuf)); 274 return; 275 } 276 277 /* xxx: more validation? */ 278 279 if ((ifi = find_ifinfo(pi->ipi6_ifindex)) == NULL) { 280 warnmsg(LOG_DEBUG, __func__, 281 "received RA from %s on an unexpected IF(%s)", 282 inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf, 283 sizeof(ntopbuf)), 284 if_indextoname(pi->ipi6_ifindex, ifnamebuf)); 285 return; 286 } 287 288 warnmsg(LOG_DEBUG, __func__, 289 "received RA from %s on %s, state is %d", 290 inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf, sizeof(ntopbuf)), 291 ifi->ifname, ifi->state); 292 293 nd_ra = (struct nd_router_advert *)icp; 294 295 /* 296 * Process the "M bit." 297 * If the value of ManagedConfigFlag changes from FALSE to TRUE, the 298 * host should invoke the stateful autoconfiguration protocol, 299 * requesting information. 300 * [RFC 4861 Section 4.2] 301 * XXX ??? [draft-ietf-v6ops-dhcpv6-slaac-problem-07] 302 */ 303 if (((nd_ra->nd_ra_flags_reserved) & ND_RA_FLAG_MANAGED) && 304 !ifi->managedconfig) { 305 const char *rasender = inet_ntop(AF_INET6, &from.sin6_addr, 306 ntopbuf, sizeof(ntopbuf)); 307 warnmsg(LOG_DEBUG, __func__, 308 "ManagedConfigFlag on %s is turned on", ifi->ifname); 309 ifi->managedconfig = 1; 310 CALL_SCRIPT(MANAGED, NULL); 311 } 312 313 /* 314 * Process the "O bit." 315 * If the value of OtherConfigFlag changes from FALSE to TRUE, the 316 * host should invoke the stateful autoconfiguration protocol, 317 * requesting information unless the "M bit" was set as well in 318 * which case the "O bit" is redundant. 319 * [RFC 4861 Section 4.2] 320 */ 321 if (((nd_ra->nd_ra_flags_reserved) & ND_RA_FLAG_OTHER) && 322 !ifi->otherconfig) { 323 const char *rasender = inet_ntop(AF_INET6, &from.sin6_addr, 324 ntopbuf, sizeof(ntopbuf)); 325 warnmsg(LOG_DEBUG, __func__, 326 "OtherConfigFlag on %s is turned on", ifi->ifname); 327 ifi->otherconfig = 1; 328 if (!ifi->managedconfig) 329 CALL_SCRIPT(OTHER, NULL); 330 } 331 332 /* 333 * "Always" script. 334 */ 335 if (!ifi->alwaysconfig) { 336 const char *rasender = inet_ntop(AF_INET6, &from.sin6_addr, 337 ntopbuf, sizeof(ntopbuf)); 338 ifi->alwaysconfig = 1; 339 CALL_SCRIPT(ALWAYS, NULL); 340 } 341 342 clock_gettime(CLOCK_MONOTONIC_FAST, &now); 343 newent_rai = 0; 344 rai = find_rainfo(ifi, &from); 345 if (rai == NULL) { 346 ELM_MALLOC(rai, exit(1)); 347 rai->rai_ifinfo = ifi; 348 TAILQ_INIT(&rai->rai_ra_opt); 349 rai->rai_saddr.sin6_family = AF_INET6; 350 rai->rai_saddr.sin6_len = sizeof(rai->rai_saddr); 351 memcpy(&rai->rai_saddr.sin6_addr, &from.sin6_addr, 352 sizeof(rai->rai_saddr.sin6_addr)); 353 newent_rai = 1; 354 } 355 356 #define RA_OPT_NEXT_HDR(x) (struct nd_opt_hdr *)((char *)(x) + \ 357 (((struct nd_opt_hdr *)(x))->nd_opt_len * 8)) 358 /* Process RA options. */ 359 warnmsg(LOG_DEBUG, __func__, "Processing RA"); 360 raoptp = (char *)icp + sizeof(struct nd_router_advert); 361 while (raoptp < (char *)icp + msglen) { 362 ndo = (struct nd_opt_hdr *)raoptp; 363 warnmsg(LOG_DEBUG, __func__, "ndo = %p", raoptp); 364 warnmsg(LOG_DEBUG, __func__, "ndo->nd_opt_type = %d", 365 ndo->nd_opt_type); 366 warnmsg(LOG_DEBUG, __func__, "ndo->nd_opt_len = %d", 367 ndo->nd_opt_len); 368 369 if (ndo->nd_opt_len == 0) { 370 warnmsg(LOG_INFO, __func__, "invalid option length 0."); 371 break; 372 } 373 if ((char *)RA_OPT_NEXT_HDR(raoptp) > (char *)icp + msglen) { 374 warnmsg(LOG_INFO, __func__, "option length overflow."); 375 break; 376 } 377 378 switch (ndo->nd_opt_type) { 379 case ND_OPT_RDNSS: 380 rdnss = (struct nd_opt_rdnss *)raoptp; 381 382 /* 383 * The option header is 8 bytes long and each address 384 * occupies 16 bytes, so the option length must be 385 * greater than or equal to 24 bytes and an odd multiple 386 * of 8 bytes. See section 5.1 in RFC 6106. 387 */ 388 if (rdnss->nd_opt_rdnss_len < 3 || 389 rdnss->nd_opt_rdnss_len % 2 == 0) { 390 warnmsg(LOG_INFO, __func__, 391 "too short RDNSS option in RA from %s " 392 "was ignored.", 393 inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf, 394 sizeof(ntopbuf))); 395 break; 396 } 397 398 addr = (struct in6_addr *)(void *)(raoptp + sizeof(*rdnss)); 399 while ((char *)addr < (char *)RA_OPT_NEXT_HDR(raoptp)) { 400 if (inet_ntop(AF_INET6, addr, ntopbuf, 401 sizeof(ntopbuf)) == NULL) { 402 warnmsg(LOG_INFO, __func__, 403 "an invalid address in RDNSS option" 404 " in RA from %s was ignored.", 405 inet_ntop(AF_INET6, &from.sin6_addr, 406 ntopbuf, sizeof(ntopbuf))); 407 addr++; 408 continue; 409 } 410 if (IN6_IS_ADDR_LINKLOCAL(addr)) 411 /* XXX: % has to be escaped here */ 412 l = snprintf(nsbuf, sizeof(nsbuf), 413 "%s%c%s", ntopbuf, 414 SCOPE_DELIMITER, 415 ifi->ifname); 416 else 417 l = snprintf(nsbuf, sizeof(nsbuf), 418 "%s", ntopbuf); 419 if (l < 0 || (size_t)l >= sizeof(nsbuf)) { 420 warnmsg(LOG_ERR, __func__, 421 "address copying error in " 422 "RDNSS option: %d.", l); 423 addr++; 424 continue; 425 } 426 warnmsg(LOG_DEBUG, __func__, "nsbuf = %s", 427 nsbuf); 428 429 newent_rao = 0; 430 rao = find_raopt(rai, ndo->nd_opt_type, nsbuf, 431 strlen(nsbuf)); 432 if (rao == NULL) { 433 ELM_MALLOC(rao, break); 434 rao->rao_type = ndo->nd_opt_type; 435 rao->rao_len = strlen(nsbuf); 436 rao->rao_msg = strdup(nsbuf); 437 if (rao->rao_msg == NULL) { 438 warnmsg(LOG_ERR, __func__, 439 "strdup failed: %s", 440 strerror(errno)); 441 free(rao); 442 addr++; 443 continue; 444 } 445 newent_rao = 1; 446 } 447 /* Set expiration timer */ 448 memset(&rao->rao_expire, 0, 449 sizeof(rao->rao_expire)); 450 memset(&lifetime, 0, sizeof(lifetime)); 451 lifetime.tv_sec = 452 ntohl(rdnss->nd_opt_rdnss_lifetime); 453 TS_ADD(&now, &lifetime, &rao->rao_expire); 454 455 if (newent_rao) 456 TAILQ_INSERT_TAIL(&rai->rai_ra_opt, 457 rao, rao_next); 458 addr++; 459 } 460 break; 461 case ND_OPT_DNSSL: 462 dnssl = (struct nd_opt_dnssl *)raoptp; 463 464 /* Optlen sanity check (Section 5.3.1 in RFC 6106) */ 465 if (dnssl->nd_opt_dnssl_len < 2) { 466 warnmsg(LOG_INFO, __func__, 467 "too short DNSSL option" 468 "in RA from %s was ignored.", 469 inet_ntop(AF_INET6, &from.sin6_addr, 470 ntopbuf, sizeof(ntopbuf))); 471 break; 472 } 473 474 /* 475 * Ensure NUL-termination in DNSSL in case of 476 * malformed field. 477 */ 478 p = (char *)RA_OPT_NEXT_HDR(raoptp); 479 *(p - 1) = '\0'; 480 481 p = raoptp + sizeof(*dnssl); 482 while (1 < (len = dname_labeldec(dname, sizeof(dname), 483 p))) { 484 /* length == 1 means empty string */ 485 warnmsg(LOG_DEBUG, __func__, "dname = %s", 486 dname); 487 488 newent_rao = 0; 489 rao = find_raopt(rai, ndo->nd_opt_type, dname, 490 strlen(dname)); 491 if (rao == NULL) { 492 ELM_MALLOC(rao, break); 493 rao->rao_type = ndo->nd_opt_type; 494 rao->rao_len = strlen(dname); 495 rao->rao_msg = strdup(dname); 496 if (rao->rao_msg == NULL) { 497 warnmsg(LOG_ERR, __func__, 498 "strdup failed: %s", 499 strerror(errno)); 500 free(rao); 501 addr++; 502 continue; 503 } 504 newent_rao = 1; 505 } 506 /* Set expiration timer */ 507 memset(&rao->rao_expire, 0, 508 sizeof(rao->rao_expire)); 509 memset(&lifetime, 0, sizeof(lifetime)); 510 lifetime.tv_sec = 511 ntohl(dnssl->nd_opt_dnssl_lifetime); 512 TS_ADD(&now, &lifetime, &rao->rao_expire); 513 514 if (newent_rao) 515 TAILQ_INSERT_TAIL(&rai->rai_ra_opt, 516 rao, rao_next); 517 p += len; 518 } 519 break; 520 default: 521 /* nothing to do for other options */ 522 break; 523 } 524 raoptp = (char *)RA_OPT_NEXT_HDR(raoptp); 525 } 526 if (newent_rai) 527 TAILQ_INSERT_TAIL(&ifi->ifi_rainfo, rai, rai_next); 528 529 ra_opt_handler(ifi); 530 ifi->racnt++; 531 532 switch (ifi->state) { 533 case IFS_IDLE: /* should be ignored */ 534 case IFS_DELAY: /* right? */ 535 break; 536 case IFS_PROBE: 537 ifi->state = IFS_IDLE; 538 ifi->probes = 0; 539 rtsol_timer_update(ifi); 540 break; 541 } 542 } 543 544 static char resstr_ns_prefix[] = "nameserver "; 545 static char resstr_sh_prefix[] = "search "; 546 static char resstr_nl[] = "\n"; 547 static char resstr_sp[] = " "; 548 549 int 550 ra_opt_handler(struct ifinfo *ifi) 551 { 552 struct ra_opt *rao; 553 struct rainfo *rai; 554 struct script_msg *smp1, *smp2, *smp3; 555 struct timespec now; 556 struct script_msg_head_t sm_rdnss_head = 557 TAILQ_HEAD_INITIALIZER(sm_rdnss_head); 558 struct script_msg_head_t sm_dnssl_head = 559 TAILQ_HEAD_INITIALIZER(sm_dnssl_head); 560 561 int dcount, dlen; 562 563 dcount = 0; 564 dlen = strlen(resstr_sh_prefix) + strlen(resstr_nl); 565 clock_gettime(CLOCK_MONOTONIC_FAST, &now); 566 567 /* 568 * All options from multiple RAs with the same or different 569 * source addresses on a single interface will be gathered and 570 * handled, not overridden. [RFC 4861 6.3.4] 571 */ 572 TAILQ_FOREACH(rai, &ifi->ifi_rainfo, rai_next) { 573 TAILQ_FOREACH(rao, &rai->rai_ra_opt, rao_next) { 574 switch (rao->rao_type) { 575 case ND_OPT_RDNSS: 576 if (TS_CMP(&now, &rao->rao_expire, >)) { 577 warnmsg(LOG_INFO, __func__, 578 "expired rdnss entry: %s", 579 (char *)rao->rao_msg); 580 break; 581 } 582 ELM_MALLOC(smp1, continue); 583 ELM_MALLOC(smp2, goto free1); 584 ELM_MALLOC(smp3, goto free2); 585 smp1->sm_msg = resstr_ns_prefix; 586 TAILQ_INSERT_TAIL(&sm_rdnss_head, smp1, 587 sm_next); 588 smp2->sm_msg = rao->rao_msg; 589 TAILQ_INSERT_TAIL(&sm_rdnss_head, smp2, 590 sm_next); 591 smp3->sm_msg = resstr_nl; 592 TAILQ_INSERT_TAIL(&sm_rdnss_head, smp3, 593 sm_next); 594 ifi->ifi_rdnss = IFI_DNSOPT_STATE_RECEIVED; 595 break; 596 case ND_OPT_DNSSL: 597 if (TS_CMP(&now, &rao->rao_expire, >)) { 598 warnmsg(LOG_INFO, __func__, 599 "expired dnssl entry: %s", 600 (char *)rao->rao_msg); 601 break; 602 } 603 dcount++; 604 /* Check resolv.conf(5) restrictions. */ 605 if (dcount > 6) { 606 warnmsg(LOG_INFO, __func__, 607 "dnssl entry exceeding maximum count (%d>6)" 608 ": %s", dcount, (char *)rao->rao_msg); 609 break; 610 } 611 if (256 < dlen + strlen(rao->rao_msg) + 612 strlen(resstr_sp)) { 613 warnmsg(LOG_INFO, __func__, 614 "dnssl entry exceeding maximum length " 615 "(>256): %s", (char *)rao->rao_msg); 616 break; 617 } 618 ELM_MALLOC(smp1, continue); 619 ELM_MALLOC(smp2, goto free1); 620 if (TAILQ_EMPTY(&sm_dnssl_head)) { 621 ELM_MALLOC(smp3, goto free2); 622 smp3->sm_msg = resstr_sh_prefix; 623 TAILQ_INSERT_TAIL(&sm_dnssl_head, smp3, 624 sm_next); 625 } 626 smp1->sm_msg = rao->rao_msg; 627 TAILQ_INSERT_TAIL(&sm_dnssl_head, smp1, 628 sm_next); 629 smp2->sm_msg = resstr_sp; 630 TAILQ_INSERT_TAIL(&sm_dnssl_head, smp2, 631 sm_next); 632 dlen += strlen(rao->rao_msg) + 633 strlen(resstr_sp); 634 ifi->ifi_dnssl = IFI_DNSOPT_STATE_RECEIVED; 635 break; 636 } 637 continue; 638 free2: 639 free(smp2); 640 free1: 641 free(smp1); 642 } 643 /* Call the script for each information source. */ 644 if (uflag) 645 ra_opt_rdnss_dispatch(ifi, rai, &sm_rdnss_head, 646 &sm_dnssl_head); 647 } 648 /* Call the script for each interface. */ 649 if (!uflag) 650 ra_opt_rdnss_dispatch(ifi, NULL, &sm_rdnss_head, 651 &sm_dnssl_head); 652 return (0); 653 } 654 655 char * 656 make_rsid(const char *ifname, const char *origin, struct rainfo *rai) 657 { 658 char hbuf[NI_MAXHOST]; 659 660 if (rai == NULL) 661 sprintf(rsid, "%s:%s", ifname, origin); 662 else { 663 if (!IN6_IS_ADDR_LINKLOCAL(&rai->rai_saddr.sin6_addr)) 664 return (NULL); 665 if (getnameinfo((struct sockaddr *)&rai->rai_saddr, 666 rai->rai_saddr.sin6_len, hbuf, sizeof(hbuf), NULL, 0, 667 NI_NUMERICHOST) != 0) 668 return (NULL); 669 sprintf(rsid, "%s:%s:[%s]", ifname, origin, hbuf); 670 } 671 warnmsg(LOG_DEBUG, __func__, "rsid = [%s]", rsid); 672 return (rsid); 673 } 674 675 int 676 ra_opt_rdnss_dispatch(struct ifinfo *ifi, struct rainfo *rai, 677 struct script_msg_head_t *sm_rdnss_head, 678 struct script_msg_head_t *sm_dnssl_head) 679 { 680 struct script_msg *smp1; 681 const char *r; 682 int error; 683 684 error = 0; 685 /* Add \n for DNSSL list. */ 686 if (!TAILQ_EMPTY(sm_dnssl_head)) { 687 ELM_MALLOC(smp1, goto ra_opt_rdnss_freeit); 688 smp1->sm_msg = resstr_nl; 689 TAILQ_INSERT_TAIL(sm_dnssl_head, smp1, sm_next); 690 } 691 TAILQ_CONCAT(sm_rdnss_head, sm_dnssl_head, sm_next); 692 693 r = make_rsid(ifi->ifname, DNSINFO_ORIGIN_LABEL, uflag ? rai : NULL); 694 if (r == NULL) { 695 warnmsg(LOG_ERR, __func__, "make_rsid() failed. " 696 "Script was not invoked."); 697 error = 1; 698 goto ra_opt_rdnss_freeit; 699 } 700 if (!TAILQ_EMPTY(sm_rdnss_head)) 701 CALL_SCRIPT(RESADD, sm_rdnss_head); 702 else if (ifi->ifi_rdnss == IFI_DNSOPT_STATE_RECEIVED || 703 ifi->ifi_dnssl == IFI_DNSOPT_STATE_RECEIVED) { 704 CALL_SCRIPT(RESDEL, NULL); 705 ifi->ifi_rdnss = IFI_DNSOPT_STATE_NOINFO; 706 ifi->ifi_dnssl = IFI_DNSOPT_STATE_NOINFO; 707 } 708 709 ra_opt_rdnss_freeit: 710 /* Clear script message queue. */ 711 if (!TAILQ_EMPTY(sm_rdnss_head)) { 712 while ((smp1 = TAILQ_FIRST(sm_rdnss_head)) != NULL) { 713 TAILQ_REMOVE(sm_rdnss_head, smp1, sm_next); 714 free(smp1); 715 } 716 } 717 if (!TAILQ_EMPTY(sm_dnssl_head)) { 718 while ((smp1 = TAILQ_FIRST(sm_dnssl_head)) != NULL) { 719 TAILQ_REMOVE(sm_dnssl_head, smp1, sm_next); 720 free(smp1); 721 } 722 } 723 return (error); 724 } 725 726 static struct ra_opt * 727 find_raopt(struct rainfo *rai, int type, void *msg, size_t len) 728 { 729 struct ra_opt *rao; 730 731 TAILQ_FOREACH(rao, &rai->rai_ra_opt, rao_next) { 732 if (rao->rao_type == type && 733 rao->rao_len == strlen(msg) && 734 memcmp(rao->rao_msg, msg, len) == 0) 735 break; 736 } 737 738 return (rao); 739 } 740 741 static void 742 call_script(const char *const argv[], struct script_msg_head_t *sm_head) 743 { 744 struct script_msg *smp; 745 ssize_t len; 746 int status, wfd; 747 748 if (argv[0] == NULL) 749 return; 750 751 wfd = cap_script_run(capscript, argv); 752 if (wfd == -1) { 753 warnmsg(LOG_ERR, __func__, 754 "failed to run %s: %s", argv[0], strerror(errno)); 755 return; 756 } 757 758 if (sm_head != NULL) { 759 TAILQ_FOREACH(smp, sm_head, sm_next) { 760 len = strlen(smp->sm_msg); 761 warnmsg(LOG_DEBUG, __func__, "write to child = %s(%zd)", 762 smp->sm_msg, len); 763 if (write(wfd, smp->sm_msg, len) != len) { 764 warnmsg(LOG_ERR, __func__, 765 "write to child failed: %s", 766 strerror(errno)); 767 break; 768 } 769 } 770 } 771 772 (void)close(wfd); 773 774 if (cap_script_wait(capscript, &status) != 0) 775 warnmsg(LOG_ERR, __func__, "wait(): %s", strerror(errno)); 776 else 777 warnmsg(LOG_DEBUG, __func__, "script \"%s\" status %d", 778 argv[0], status); 779 } 780 781 /* Decode domain name label encoding in RFC 1035 Section 3.1 */ 782 static size_t 783 dname_labeldec(char *dst, size_t dlen, const char *src) 784 { 785 size_t len; 786 const char *src_origin; 787 const char *src_last; 788 const char *dst_origin; 789 790 src_origin = src; 791 src_last = strchr(src, '\0'); 792 dst_origin = dst; 793 memset(dst, '\0', dlen); 794 while ((len = (*src++) & 0x3f) && 795 src + len <= src_last && 796 len + (dst == dst_origin ? 0 : 1) < dlen) { 797 if (dst != dst_origin) { 798 *dst++ = '.'; 799 dlen--; 800 } 801 warnmsg(LOG_DEBUG, __func__, "labellen = %zd", len); 802 memcpy(dst, src, len); 803 src += len; 804 dst += len; 805 dlen -= len; 806 } 807 *dst = '\0'; 808 809 /* 810 * XXX validate that domain name only contains valid characters 811 * for two reasons: 1) correctness, 2) we do not want to pass 812 * possible malicious, unescaped characters like `` to a script 813 * or program that could be exploited that way. 814 */ 815 816 return (src - src_origin); 817 } 818