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 83 #define _ARGS_OTHER otherconf_script, ifi->ifname 84 #define _ARGS_RESADD resolvconf_script, "-a", rsid 85 #define _ARGS_RESDEL resolvconf_script, "-d", rsid 86 87 #define CALL_SCRIPT(name, sm_head) do { \ 88 const char *const sarg[] = { _ARGS_##name, NULL }; \ 89 call_script(sarg, sm_head); \ 90 } while (0) 91 92 #define ELM_MALLOC(p, error_action) do { \ 93 p = malloc(sizeof(*p)); \ 94 if (p == NULL) { \ 95 warnmsg(LOG_ERR, __func__, "malloc failed: %s", \ 96 strerror(errno)); \ 97 error_action; \ 98 } \ 99 memset(p, 0, sizeof(*p)); \ 100 } while (0) 101 102 int 103 recvsockopen(void) 104 { 105 struct icmp6_filter filt; 106 cap_rights_t rights; 107 int on, sock; 108 109 if ((sock = socket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6)) < 0) { 110 warnmsg(LOG_ERR, __func__, "socket: %s", strerror(errno)); 111 goto fail; 112 } 113 114 /* Provide info about the receiving interface. */ 115 on = 1; 116 if (setsockopt(sock, IPPROTO_IPV6, IPV6_RECVPKTINFO, &on, 117 sizeof(on)) < 0) { 118 warnmsg(LOG_ERR, __func__, "setsockopt(IPV6_RECVPKTINFO): %s", 119 strerror(errno)); 120 goto fail; 121 } 122 123 /* Include the hop limit from the received header. */ 124 on = 1; 125 if (setsockopt(sock, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &on, 126 sizeof(on)) < 0) { 127 warnmsg(LOG_ERR, __func__, "setsockopt(IPV6_RECVHOPLIMIT): %s", 128 strerror(errno)); 129 goto fail; 130 } 131 132 /* Filter out everything except for Router Advertisements. */ 133 ICMP6_FILTER_SETBLOCKALL(&filt); 134 ICMP6_FILTER_SETPASS(ND_ROUTER_ADVERT, &filt); 135 if (setsockopt(sock, IPPROTO_ICMPV6, ICMP6_FILTER, &filt, 136 sizeof(filt)) == -1) { 137 warnmsg(LOG_ERR, __func__, "setsockopt(ICMP6_FILTER): %s", 138 strerror(errno)); 139 goto fail; 140 } 141 142 cap_rights_init(&rights, CAP_EVENT, CAP_RECV); 143 if (caph_rights_limit(sock, &rights) < 0) { 144 warnmsg(LOG_ERR, __func__, "caph_rights_limit(): %s", 145 strerror(errno)); 146 goto fail; 147 } 148 149 return (sock); 150 151 fail: 152 if (sock >= 0) 153 (void)close(sock); 154 return (-1); 155 } 156 157 void 158 rtsol_input(int sock) 159 { 160 uint8_t cmsg[CMSG_SPACE(sizeof(struct in6_pktinfo)) + 161 CMSG_SPACE(sizeof(int))]; 162 struct iovec iov; 163 struct msghdr hdr; 164 struct sockaddr_in6 from; 165 char answer[1500], ntopbuf[INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ]; 166 int l, ifindex = 0, *hlimp = NULL; 167 ssize_t msglen; 168 struct in6_pktinfo *pi = NULL; 169 struct ifinfo *ifi = NULL; 170 struct ra_opt *rao = NULL; 171 struct icmp6_hdr *icp; 172 struct nd_router_advert *nd_ra; 173 struct cmsghdr *cm; 174 struct rainfo *rai; 175 char *p, *raoptp; 176 struct in6_addr *addr; 177 struct nd_opt_hdr *ndo; 178 struct nd_opt_rdnss *rdnss; 179 struct nd_opt_dnssl *dnssl; 180 size_t len; 181 char nsbuf[INET6_ADDRSTRLEN + 1 + IFNAMSIZ + 1]; 182 char dname[NI_MAXHOST]; 183 struct timespec lifetime, now; 184 int newent_rai, newent_rao; 185 186 memset(&hdr, 0, sizeof(hdr)); 187 hdr.msg_iov = &iov; 188 hdr.msg_iovlen = 1; 189 hdr.msg_name = &from; 190 hdr.msg_namelen = sizeof(from); 191 hdr.msg_control = cmsg; 192 hdr.msg_controllen = sizeof(cmsg); 193 194 iov.iov_base = (caddr_t)answer; 195 iov.iov_len = sizeof(answer); 196 197 if ((msglen = recvmsg(sock, &hdr, 0)) < 0) { 198 warnmsg(LOG_ERR, __func__, "recvmsg: %s", strerror(errno)); 199 return; 200 } 201 202 /* Extract control message info. */ 203 for (cm = (struct cmsghdr *)CMSG_FIRSTHDR(&hdr); cm != NULL; 204 cm = (struct cmsghdr *)CMSG_NXTHDR(&hdr, cm)) { 205 if (cm->cmsg_level == IPPROTO_IPV6 && 206 cm->cmsg_type == IPV6_PKTINFO && 207 cm->cmsg_len == CMSG_LEN(sizeof(struct in6_pktinfo))) { 208 pi = (struct in6_pktinfo *)(void *)(CMSG_DATA(cm)); 209 ifindex = pi->ipi6_ifindex; 210 } 211 if (cm->cmsg_level == IPPROTO_IPV6 && 212 cm->cmsg_type == IPV6_HOPLIMIT && 213 cm->cmsg_len == CMSG_LEN(sizeof(int))) 214 hlimp = (int *)(void *)CMSG_DATA(cm); 215 } 216 217 if (ifindex == 0) { 218 warnmsg(LOG_ERR, __func__, 219 "failed to get receiving interface"); 220 return; 221 } 222 if (hlimp == NULL) { 223 warnmsg(LOG_ERR, __func__, 224 "failed to get receiving hop limit"); 225 return; 226 } 227 228 if ((size_t)msglen < sizeof(struct nd_router_advert)) { 229 warnmsg(LOG_INFO, __func__, 230 "packet size(%zd) is too short", msglen); 231 return; 232 } 233 234 icp = (struct icmp6_hdr *)iov.iov_base; 235 if (icp->icmp6_type != ND_ROUTER_ADVERT) { 236 /* 237 * this should not happen because we configured a filter 238 * that only passes RAs on the receiving socket. 239 */ 240 warnmsg(LOG_ERR, __func__, 241 "invalid icmp type(%d) from %s on %s", icp->icmp6_type, 242 inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf, 243 sizeof(ntopbuf)), 244 if_indextoname(pi->ipi6_ifindex, ifnamebuf)); 245 return; 246 } 247 248 if (icp->icmp6_code != 0) { 249 warnmsg(LOG_INFO, __func__, 250 "invalid icmp code(%d) from %s on %s", icp->icmp6_code, 251 inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf, 252 sizeof(ntopbuf)), 253 if_indextoname(pi->ipi6_ifindex, ifnamebuf)); 254 return; 255 } 256 257 if (*hlimp != 255) { 258 warnmsg(LOG_INFO, __func__, 259 "invalid RA with hop limit(%d) from %s on %s", 260 *hlimp, 261 inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf, 262 sizeof(ntopbuf)), 263 if_indextoname(pi->ipi6_ifindex, ifnamebuf)); 264 return; 265 } 266 267 if (pi && !IN6_IS_ADDR_LINKLOCAL(&from.sin6_addr)) { 268 warnmsg(LOG_INFO, __func__, 269 "invalid RA with non link-local source from %s on %s", 270 inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf, 271 sizeof(ntopbuf)), 272 if_indextoname(pi->ipi6_ifindex, ifnamebuf)); 273 return; 274 } 275 276 /* xxx: more validation? */ 277 278 if ((ifi = find_ifinfo(pi->ipi6_ifindex)) == NULL) { 279 warnmsg(LOG_DEBUG, __func__, 280 "received RA from %s on an unexpected IF(%s)", 281 inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf, 282 sizeof(ntopbuf)), 283 if_indextoname(pi->ipi6_ifindex, ifnamebuf)); 284 return; 285 } 286 287 warnmsg(LOG_DEBUG, __func__, 288 "received RA from %s on %s, state is %d", 289 inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf, sizeof(ntopbuf)), 290 ifi->ifname, ifi->state); 291 292 nd_ra = (struct nd_router_advert *)icp; 293 294 /* 295 * Process the "M bit." 296 * If the value of ManagedConfigFlag changes from FALSE to TRUE, the 297 * host should invoke the stateful autoconfiguration protocol, 298 * requesting information. 299 * [RFC 4861 Section 4.2] 300 * XXX ??? [draft-ietf-v6ops-dhcpv6-slaac-problem-07] 301 */ 302 if (((nd_ra->nd_ra_flags_reserved) & ND_RA_FLAG_MANAGED) && 303 !ifi->managedconfig) { 304 warnmsg(LOG_DEBUG, __func__, 305 "ManagedConfigFlag on %s is turned on", ifi->ifname); 306 ifi->managedconfig = 1; 307 CALL_SCRIPT(MANAGED, NULL); 308 } 309 310 /* 311 * Process the "O bit." 312 * If the value of OtherConfigFlag changes from FALSE to TRUE, the 313 * host should invoke the stateful autoconfiguration protocol, 314 * requesting information unless the "M bit" was set as well in 315 * which case the "O bit" is redundant. 316 * [RFC 4861 Section 4.2] 317 */ 318 if (((nd_ra->nd_ra_flags_reserved) & ND_RA_FLAG_OTHER) && 319 !ifi->otherconfig) { 320 warnmsg(LOG_DEBUG, __func__, 321 "OtherConfigFlag on %s is turned on", ifi->ifname); 322 ifi->otherconfig = 1; 323 if (!ifi->managedconfig) 324 CALL_SCRIPT(OTHER, NULL); 325 } 326 clock_gettime(CLOCK_MONOTONIC_FAST, &now); 327 newent_rai = 0; 328 rai = find_rainfo(ifi, &from); 329 if (rai == NULL) { 330 ELM_MALLOC(rai, exit(1)); 331 rai->rai_ifinfo = ifi; 332 TAILQ_INIT(&rai->rai_ra_opt); 333 rai->rai_saddr.sin6_family = AF_INET6; 334 rai->rai_saddr.sin6_len = sizeof(rai->rai_saddr); 335 memcpy(&rai->rai_saddr.sin6_addr, &from.sin6_addr, 336 sizeof(rai->rai_saddr.sin6_addr)); 337 newent_rai = 1; 338 } 339 340 #define RA_OPT_NEXT_HDR(x) (struct nd_opt_hdr *)((char *)x + \ 341 (((struct nd_opt_hdr *)x)->nd_opt_len * 8)) 342 /* Process RA options. */ 343 warnmsg(LOG_DEBUG, __func__, "Processing RA"); 344 raoptp = (char *)icp + sizeof(struct nd_router_advert); 345 while (raoptp < (char *)icp + msglen) { 346 ndo = (struct nd_opt_hdr *)raoptp; 347 warnmsg(LOG_DEBUG, __func__, "ndo = %p", raoptp); 348 warnmsg(LOG_DEBUG, __func__, "ndo->nd_opt_type = %d", 349 ndo->nd_opt_type); 350 warnmsg(LOG_DEBUG, __func__, "ndo->nd_opt_len = %d", 351 ndo->nd_opt_len); 352 353 switch (ndo->nd_opt_type) { 354 case ND_OPT_RDNSS: 355 rdnss = (struct nd_opt_rdnss *)raoptp; 356 357 /* Optlen sanity check (Section 5.3.1 in RFC 6106) */ 358 if (rdnss->nd_opt_rdnss_len < 3) { 359 warnmsg(LOG_INFO, __func__, 360 "too short RDNSS option" 361 "in RA from %s was ignored.", 362 inet_ntop(AF_INET6, &from.sin6_addr, 363 ntopbuf, sizeof(ntopbuf))); 364 break; 365 } 366 367 addr = (struct in6_addr *)(void *)(raoptp + sizeof(*rdnss)); 368 while ((char *)addr < (char *)RA_OPT_NEXT_HDR(raoptp)) { 369 if (inet_ntop(AF_INET6, addr, ntopbuf, 370 sizeof(ntopbuf)) == NULL) { 371 warnmsg(LOG_INFO, __func__, 372 "an invalid address in RDNSS option" 373 " in RA from %s was ignored.", 374 inet_ntop(AF_INET6, &from.sin6_addr, 375 ntopbuf, sizeof(ntopbuf))); 376 addr++; 377 continue; 378 } 379 if (IN6_IS_ADDR_LINKLOCAL(addr)) 380 /* XXX: % has to be escaped here */ 381 l = snprintf(nsbuf, sizeof(nsbuf), 382 "%s%c%s", ntopbuf, 383 SCOPE_DELIMITER, 384 ifi->ifname); 385 else 386 l = snprintf(nsbuf, sizeof(nsbuf), 387 "%s", ntopbuf); 388 if (l < 0 || (size_t)l >= sizeof(nsbuf)) { 389 warnmsg(LOG_ERR, __func__, 390 "address copying error in " 391 "RDNSS option: %d.", l); 392 addr++; 393 continue; 394 } 395 warnmsg(LOG_DEBUG, __func__, "nsbuf = %s", 396 nsbuf); 397 398 newent_rao = 0; 399 rao = find_raopt(rai, ndo->nd_opt_type, nsbuf, 400 strlen(nsbuf)); 401 if (rao == NULL) { 402 ELM_MALLOC(rao, break); 403 rao->rao_type = ndo->nd_opt_type; 404 rao->rao_len = strlen(nsbuf); 405 rao->rao_msg = strdup(nsbuf); 406 if (rao->rao_msg == NULL) { 407 warnmsg(LOG_ERR, __func__, 408 "strdup failed: %s", 409 strerror(errno)); 410 free(rao); 411 addr++; 412 continue; 413 } 414 newent_rao = 1; 415 } 416 /* Set expiration timer */ 417 memset(&rao->rao_expire, 0, 418 sizeof(rao->rao_expire)); 419 memset(&lifetime, 0, sizeof(lifetime)); 420 lifetime.tv_sec = 421 ntohl(rdnss->nd_opt_rdnss_lifetime); 422 TS_ADD(&now, &lifetime, &rao->rao_expire); 423 424 if (newent_rao) 425 TAILQ_INSERT_TAIL(&rai->rai_ra_opt, 426 rao, rao_next); 427 addr++; 428 } 429 break; 430 case ND_OPT_DNSSL: 431 dnssl = (struct nd_opt_dnssl *)raoptp; 432 433 /* Optlen sanity check (Section 5.3.1 in RFC 6106) */ 434 if (dnssl->nd_opt_dnssl_len < 2) { 435 warnmsg(LOG_INFO, __func__, 436 "too short DNSSL option" 437 "in RA from %s was ignored.", 438 inet_ntop(AF_INET6, &from.sin6_addr, 439 ntopbuf, sizeof(ntopbuf))); 440 break; 441 } 442 443 /* 444 * Ensure NUL-termination in DNSSL in case of 445 * malformed field. 446 */ 447 p = (char *)RA_OPT_NEXT_HDR(raoptp); 448 *(p - 1) = '\0'; 449 450 p = raoptp + sizeof(*dnssl); 451 while (1 < (len = dname_labeldec(dname, sizeof(dname), 452 p))) { 453 /* length == 1 means empty string */ 454 warnmsg(LOG_DEBUG, __func__, "dname = %s", 455 dname); 456 457 newent_rao = 0; 458 rao = find_raopt(rai, ndo->nd_opt_type, dname, 459 strlen(dname)); 460 if (rao == NULL) { 461 ELM_MALLOC(rao, break); 462 rao->rao_type = ndo->nd_opt_type; 463 rao->rao_len = strlen(dname); 464 rao->rao_msg = strdup(dname); 465 if (rao->rao_msg == NULL) { 466 warnmsg(LOG_ERR, __func__, 467 "strdup failed: %s", 468 strerror(errno)); 469 free(rao); 470 addr++; 471 continue; 472 } 473 newent_rao = 1; 474 } 475 /* Set expiration timer */ 476 memset(&rao->rao_expire, 0, 477 sizeof(rao->rao_expire)); 478 memset(&lifetime, 0, sizeof(lifetime)); 479 lifetime.tv_sec = 480 ntohl(dnssl->nd_opt_dnssl_lifetime); 481 TS_ADD(&now, &lifetime, &rao->rao_expire); 482 483 if (newent_rao) 484 TAILQ_INSERT_TAIL(&rai->rai_ra_opt, 485 rao, rao_next); 486 p += len; 487 } 488 break; 489 default: 490 /* nothing to do for other options */ 491 break; 492 } 493 raoptp = (char *)RA_OPT_NEXT_HDR(raoptp); 494 } 495 if (newent_rai) 496 TAILQ_INSERT_TAIL(&ifi->ifi_rainfo, rai, rai_next); 497 498 ra_opt_handler(ifi); 499 ifi->racnt++; 500 501 switch (ifi->state) { 502 case IFS_IDLE: /* should be ignored */ 503 case IFS_DELAY: /* right? */ 504 break; 505 case IFS_PROBE: 506 ifi->state = IFS_IDLE; 507 ifi->probes = 0; 508 rtsol_timer_update(ifi); 509 break; 510 } 511 } 512 513 static char resstr_ns_prefix[] = "nameserver "; 514 static char resstr_sh_prefix[] = "search "; 515 static char resstr_nl[] = "\n"; 516 static char resstr_sp[] = " "; 517 518 int 519 ra_opt_handler(struct ifinfo *ifi) 520 { 521 struct ra_opt *rao; 522 struct rainfo *rai; 523 struct script_msg *smp1, *smp2, *smp3; 524 struct timespec now; 525 struct script_msg_head_t sm_rdnss_head = 526 TAILQ_HEAD_INITIALIZER(sm_rdnss_head); 527 struct script_msg_head_t sm_dnssl_head = 528 TAILQ_HEAD_INITIALIZER(sm_dnssl_head); 529 530 int dcount, dlen; 531 532 dcount = 0; 533 dlen = strlen(resstr_sh_prefix) + strlen(resstr_nl); 534 clock_gettime(CLOCK_MONOTONIC_FAST, &now); 535 536 /* 537 * All options from multiple RAs with the same or different 538 * source addresses on a single interface will be gathered and 539 * handled, not overridden. [RFC 4861 6.3.4] 540 */ 541 TAILQ_FOREACH(rai, &ifi->ifi_rainfo, rai_next) { 542 TAILQ_FOREACH(rao, &rai->rai_ra_opt, rao_next) { 543 switch (rao->rao_type) { 544 case ND_OPT_RDNSS: 545 if (TS_CMP(&now, &rao->rao_expire, >)) { 546 warnmsg(LOG_INFO, __func__, 547 "expired rdnss entry: %s", 548 (char *)rao->rao_msg); 549 break; 550 } 551 ELM_MALLOC(smp1, continue); 552 ELM_MALLOC(smp2, goto free1); 553 ELM_MALLOC(smp3, goto free2); 554 smp1->sm_msg = resstr_ns_prefix; 555 TAILQ_INSERT_TAIL(&sm_rdnss_head, smp1, 556 sm_next); 557 smp2->sm_msg = rao->rao_msg; 558 TAILQ_INSERT_TAIL(&sm_rdnss_head, smp2, 559 sm_next); 560 smp3->sm_msg = resstr_nl; 561 TAILQ_INSERT_TAIL(&sm_rdnss_head, smp3, 562 sm_next); 563 ifi->ifi_rdnss = IFI_DNSOPT_STATE_RECEIVED; 564 break; 565 case ND_OPT_DNSSL: 566 if (TS_CMP(&now, &rao->rao_expire, >)) { 567 warnmsg(LOG_INFO, __func__, 568 "expired dnssl entry: %s", 569 (char *)rao->rao_msg); 570 break; 571 } 572 dcount++; 573 /* Check resolv.conf(5) restrictions. */ 574 if (dcount > 6) { 575 warnmsg(LOG_INFO, __func__, 576 "dnssl entry exceeding maximum count (%d>6)" 577 ": %s", dcount, (char *)rao->rao_msg); 578 break; 579 } 580 if (256 < dlen + strlen(rao->rao_msg) + 581 strlen(resstr_sp)) { 582 warnmsg(LOG_INFO, __func__, 583 "dnssl entry exceeding maximum length " 584 "(>256): %s", (char *)rao->rao_msg); 585 break; 586 } 587 ELM_MALLOC(smp1, continue); 588 ELM_MALLOC(smp2, goto free1); 589 if (TAILQ_EMPTY(&sm_dnssl_head)) { 590 ELM_MALLOC(smp3, goto free2); 591 smp3->sm_msg = resstr_sh_prefix; 592 TAILQ_INSERT_TAIL(&sm_dnssl_head, smp3, 593 sm_next); 594 } 595 smp1->sm_msg = rao->rao_msg; 596 TAILQ_INSERT_TAIL(&sm_dnssl_head, smp1, 597 sm_next); 598 smp2->sm_msg = resstr_sp; 599 TAILQ_INSERT_TAIL(&sm_dnssl_head, smp2, 600 sm_next); 601 dlen += strlen(rao->rao_msg) + 602 strlen(resstr_sp); 603 ifi->ifi_dnssl = IFI_DNSOPT_STATE_RECEIVED; 604 break; 605 } 606 continue; 607 free2: 608 free(smp2); 609 free1: 610 free(smp1); 611 } 612 /* Call the script for each information source. */ 613 if (uflag) 614 ra_opt_rdnss_dispatch(ifi, rai, &sm_rdnss_head, 615 &sm_dnssl_head); 616 } 617 /* Call the script for each interface. */ 618 if (!uflag) 619 ra_opt_rdnss_dispatch(ifi, NULL, &sm_rdnss_head, 620 &sm_dnssl_head); 621 return (0); 622 } 623 624 char * 625 make_rsid(const char *ifname, const char *origin, struct rainfo *rai) 626 { 627 char hbuf[NI_MAXHOST]; 628 629 if (rai == NULL) 630 sprintf(rsid, "%s:%s", ifname, origin); 631 else { 632 if (!IN6_IS_ADDR_LINKLOCAL(&rai->rai_saddr.sin6_addr)) 633 return (NULL); 634 if (getnameinfo((struct sockaddr *)&rai->rai_saddr, 635 rai->rai_saddr.sin6_len, hbuf, sizeof(hbuf), NULL, 0, 636 NI_NUMERICHOST) != 0) 637 return (NULL); 638 sprintf(rsid, "%s:%s:[%s]", ifname, origin, hbuf); 639 } 640 warnmsg(LOG_DEBUG, __func__, "rsid = [%s]", rsid); 641 return (rsid); 642 } 643 644 int 645 ra_opt_rdnss_dispatch(struct ifinfo *ifi, struct rainfo *rai, 646 struct script_msg_head_t *sm_rdnss_head, 647 struct script_msg_head_t *sm_dnssl_head) 648 { 649 struct script_msg *smp1; 650 const char *r; 651 int error; 652 653 error = 0; 654 /* Add \n for DNSSL list. */ 655 if (!TAILQ_EMPTY(sm_dnssl_head)) { 656 ELM_MALLOC(smp1, goto ra_opt_rdnss_freeit); 657 smp1->sm_msg = resstr_nl; 658 TAILQ_INSERT_TAIL(sm_dnssl_head, smp1, sm_next); 659 } 660 TAILQ_CONCAT(sm_rdnss_head, sm_dnssl_head, sm_next); 661 662 r = make_rsid(ifi->ifname, DNSINFO_ORIGIN_LABEL, uflag ? rai : NULL); 663 if (r == NULL) { 664 warnmsg(LOG_ERR, __func__, "make_rsid() failed. " 665 "Script was not invoked."); 666 error = 1; 667 goto ra_opt_rdnss_freeit; 668 } 669 if (!TAILQ_EMPTY(sm_rdnss_head)) 670 CALL_SCRIPT(RESADD, sm_rdnss_head); 671 else if (ifi->ifi_rdnss == IFI_DNSOPT_STATE_RECEIVED || 672 ifi->ifi_dnssl == IFI_DNSOPT_STATE_RECEIVED) { 673 CALL_SCRIPT(RESDEL, NULL); 674 ifi->ifi_rdnss = IFI_DNSOPT_STATE_NOINFO; 675 ifi->ifi_dnssl = IFI_DNSOPT_STATE_NOINFO; 676 } 677 678 ra_opt_rdnss_freeit: 679 /* Clear script message queue. */ 680 if (!TAILQ_EMPTY(sm_rdnss_head)) { 681 while ((smp1 = TAILQ_FIRST(sm_rdnss_head)) != NULL) { 682 TAILQ_REMOVE(sm_rdnss_head, smp1, sm_next); 683 free(smp1); 684 } 685 } 686 if (!TAILQ_EMPTY(sm_dnssl_head)) { 687 while ((smp1 = TAILQ_FIRST(sm_dnssl_head)) != NULL) { 688 TAILQ_REMOVE(sm_dnssl_head, smp1, sm_next); 689 free(smp1); 690 } 691 } 692 return (error); 693 } 694 695 static struct ra_opt * 696 find_raopt(struct rainfo *rai, int type, void *msg, size_t len) 697 { 698 struct ra_opt *rao; 699 700 TAILQ_FOREACH(rao, &rai->rai_ra_opt, rao_next) { 701 if (rao->rao_type == type && 702 rao->rao_len == strlen(msg) && 703 memcmp(rao->rao_msg, msg, len) == 0) 704 break; 705 } 706 707 return (rao); 708 } 709 710 static void 711 call_script(const char *const argv[], struct script_msg_head_t *sm_head) 712 { 713 struct script_msg *smp; 714 ssize_t len; 715 int status, wfd; 716 717 if (argv[0] == NULL) 718 return; 719 720 wfd = cap_script_run(capscript, argv); 721 if (wfd == -1) { 722 warnmsg(LOG_ERR, __func__, 723 "failed to run %s: %s", argv[0], strerror(errno)); 724 return; 725 } 726 727 if (sm_head != NULL) { 728 TAILQ_FOREACH(smp, sm_head, sm_next) { 729 len = strlen(smp->sm_msg); 730 warnmsg(LOG_DEBUG, __func__, "write to child = %s(%zd)", 731 smp->sm_msg, len); 732 if (write(wfd, smp->sm_msg, len) != len) { 733 warnmsg(LOG_ERR, __func__, 734 "write to child failed: %s", 735 strerror(errno)); 736 break; 737 } 738 } 739 } 740 741 (void)close(wfd); 742 743 if (cap_script_wait(capscript, &status) != 0) 744 warnmsg(LOG_ERR, __func__, "wait(): %s", strerror(errno)); 745 else 746 warnmsg(LOG_DEBUG, __func__, "script \"%s\" status %d", 747 argv[0], status); 748 } 749 750 /* Decode domain name label encoding in RFC 1035 Section 3.1 */ 751 static size_t 752 dname_labeldec(char *dst, size_t dlen, const char *src) 753 { 754 size_t len; 755 const char *src_origin; 756 const char *src_last; 757 const char *dst_origin; 758 759 src_origin = src; 760 src_last = strchr(src, '\0'); 761 dst_origin = dst; 762 memset(dst, '\0', dlen); 763 while (src && (len = (uint8_t)(*src++) & 0x3f) && 764 (src + len) <= src_last && 765 (dst - dst_origin < (ssize_t)dlen)) { 766 if (dst != dst_origin) 767 *dst++ = '.'; 768 warnmsg(LOG_DEBUG, __func__, "labellen = %zd", len); 769 memcpy(dst, src, len); 770 src += len; 771 dst += len; 772 } 773 *dst = '\0'; 774 775 /* 776 * XXX validate that domain name only contains valid characters 777 * for two reasons: 1) correctness, 2) we do not want to pass 778 * possible malicious, unescaped characters like `` to a script 779 * or program that could be exploited that way. 780 */ 781 782 return (src - src_origin); 783 } 784