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 72static char rsid[IFNAMSIZ + 1 + sizeof(DNSINFO_ORIGIN_LABEL) + 1 + NI_MAXHOST]; 73struct ifinfo_head_t ifinfo_head = TAILQ_HEAD_INITIALIZER(ifinfo_head); 74 75static void call_script(const char *const *, struct script_msg_head_t *); 76static size_t dname_labeldec(char *, size_t, const char *); 77static struct ra_opt *find_raopt(struct rainfo *, int, void *, size_t); 78static int ra_opt_rdnss_dispatch(struct ifinfo *, struct rainfo *, 79 struct script_msg_head_t *, struct script_msg_head_t *); 80static 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 102int 103recvsockopen(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 151fail: 152 if (sock >= 0) 153 (void)close(sock); 154 return (-1); 155} 156 157void 158rtsol_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 if (ndo->nd_opt_len == 0) { 354 warnmsg(LOG_INFO, __func__, "invalid option length 0."); 355 break; 356 } 357 if ((char *)RA_OPT_NEXT_HDR(raoptp) > (char *)icp + msglen) { 358 warnmsg(LOG_INFO, __func__, "option length overflow."); 359 break; 360 } 361 362 switch (ndo->nd_opt_type) { 363 case ND_OPT_RDNSS: 364 rdnss = (struct nd_opt_rdnss *)raoptp; 365 366 /* 367 * The option header is 8 bytes long and each address 368 * occupies 16 bytes, so the option length must be 369 * greater than or equal to 24 bytes and an odd multiple 370 * of 8 bytes. See section 5.1 in RFC 6106. 371 */ 372 if (rdnss->nd_opt_rdnss_len < 3 || 373 rdnss->nd_opt_rdnss_len % 2 == 0) { 374 warnmsg(LOG_INFO, __func__, 375 "too short RDNSS option in RA from %s " 376 "was ignored.", 377 inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf, 378 sizeof(ntopbuf))); 379 break; 380 } 381 382 addr = (struct in6_addr *)(void *)(raoptp + sizeof(*rdnss)); 383 while ((char *)addr < (char *)RA_OPT_NEXT_HDR(raoptp)) { 384 if (inet_ntop(AF_INET6, addr, ntopbuf, 385 sizeof(ntopbuf)) == NULL) { 386 warnmsg(LOG_INFO, __func__, 387 "an invalid address in RDNSS option" 388 " in RA from %s was ignored.", 389 inet_ntop(AF_INET6, &from.sin6_addr, 390 ntopbuf, sizeof(ntopbuf))); 391 addr++; 392 continue; 393 } 394 if (IN6_IS_ADDR_LINKLOCAL(addr)) 395 /* XXX: % has to be escaped here */ 396 l = snprintf(nsbuf, sizeof(nsbuf), 397 "%s%c%s", ntopbuf, 398 SCOPE_DELIMITER, 399 ifi->ifname); 400 else 401 l = snprintf(nsbuf, sizeof(nsbuf), 402 "%s", ntopbuf); 403 if (l < 0 || (size_t)l >= sizeof(nsbuf)) { 404 warnmsg(LOG_ERR, __func__, 405 "address copying error in " 406 "RDNSS option: %d.", l); 407 addr++; 408 continue; 409 } 410 warnmsg(LOG_DEBUG, __func__, "nsbuf = %s", 411 nsbuf); 412 413 newent_rao = 0; 414 rao = find_raopt(rai, ndo->nd_opt_type, nsbuf, 415 strlen(nsbuf)); 416 if (rao == NULL) { 417 ELM_MALLOC(rao, break); 418 rao->rao_type = ndo->nd_opt_type; 419 rao->rao_len = strlen(nsbuf); 420 rao->rao_msg = strdup(nsbuf); 421 if (rao->rao_msg == NULL) { 422 warnmsg(LOG_ERR, __func__, 423 "strdup failed: %s", 424 strerror(errno)); 425 free(rao); 426 addr++; 427 continue; 428 } 429 newent_rao = 1; 430 } 431 /* Set expiration timer */ 432 memset(&rao->rao_expire, 0, 433 sizeof(rao->rao_expire)); 434 memset(&lifetime, 0, sizeof(lifetime)); 435 lifetime.tv_sec = 436 ntohl(rdnss->nd_opt_rdnss_lifetime); 437 TS_ADD(&now, &lifetime, &rao->rao_expire); 438 439 if (newent_rao) 440 TAILQ_INSERT_TAIL(&rai->rai_ra_opt, 441 rao, rao_next); 442 addr++; 443 } 444 break; 445 case ND_OPT_DNSSL: 446 dnssl = (struct nd_opt_dnssl *)raoptp; 447 448 /* Optlen sanity check (Section 5.3.1 in RFC 6106) */ 449 if (dnssl->nd_opt_dnssl_len < 2) { 450 warnmsg(LOG_INFO, __func__, 451 "too short DNSSL option" 452 "in RA from %s was ignored.", 453 inet_ntop(AF_INET6, &from.sin6_addr, 454 ntopbuf, sizeof(ntopbuf))); 455 break; 456 } 457 458 /* 459 * Ensure NUL-termination in DNSSL in case of 460 * malformed field. 461 */ 462 p = (char *)RA_OPT_NEXT_HDR(raoptp); 463 *(p - 1) = '\0'; 464 465 p = raoptp + sizeof(*dnssl); 466 while (1 < (len = dname_labeldec(dname, sizeof(dname), 467 p))) { 468 /* length == 1 means empty string */ 469 warnmsg(LOG_DEBUG, __func__, "dname = %s", 470 dname); 471 472 newent_rao = 0; 473 rao = find_raopt(rai, ndo->nd_opt_type, dname, 474 strlen(dname)); 475 if (rao == NULL) { 476 ELM_MALLOC(rao, break); 477 rao->rao_type = ndo->nd_opt_type; 478 rao->rao_len = strlen(dname); 479 rao->rao_msg = strdup(dname); 480 if (rao->rao_msg == NULL) { 481 warnmsg(LOG_ERR, __func__, 482 "strdup failed: %s", 483 strerror(errno)); 484 free(rao); 485 addr++; 486 continue; 487 } 488 newent_rao = 1; 489 } 490 /* Set expiration timer */ 491 memset(&rao->rao_expire, 0, 492 sizeof(rao->rao_expire)); 493 memset(&lifetime, 0, sizeof(lifetime)); 494 lifetime.tv_sec = 495 ntohl(dnssl->nd_opt_dnssl_lifetime); 496 TS_ADD(&now, &lifetime, &rao->rao_expire); 497 498 if (newent_rao) 499 TAILQ_INSERT_TAIL(&rai->rai_ra_opt, 500 rao, rao_next); 501 p += len; 502 } 503 break; 504 default: 505 /* nothing to do for other options */ 506 break; 507 } 508 raoptp = (char *)RA_OPT_NEXT_HDR(raoptp); 509 } 510 if (newent_rai) 511 TAILQ_INSERT_TAIL(&ifi->ifi_rainfo, rai, rai_next); 512 513 ra_opt_handler(ifi); 514 ifi->racnt++; 515 516 switch (ifi->state) { 517 case IFS_IDLE: /* should be ignored */ 518 case IFS_DELAY: /* right? */ 519 break; 520 case IFS_PROBE: 521 ifi->state = IFS_IDLE; 522 ifi->probes = 0; 523 rtsol_timer_update(ifi); 524 break; 525 } 526} 527 528static char resstr_ns_prefix[] = "nameserver "; 529static char resstr_sh_prefix[] = "search "; 530static char resstr_nl[] = "\n"; 531static char resstr_sp[] = " "; 532 533int 534ra_opt_handler(struct ifinfo *ifi) 535{ 536 struct ra_opt *rao; 537 struct rainfo *rai; 538 struct script_msg *smp1, *smp2, *smp3; 539 struct timespec now; 540 struct script_msg_head_t sm_rdnss_head = 541 TAILQ_HEAD_INITIALIZER(sm_rdnss_head); 542 struct script_msg_head_t sm_dnssl_head = 543 TAILQ_HEAD_INITIALIZER(sm_dnssl_head); 544 545 int dcount, dlen; 546 547 dcount = 0; 548 dlen = strlen(resstr_sh_prefix) + strlen(resstr_nl); 549 clock_gettime(CLOCK_MONOTONIC_FAST, &now); 550 551 /* 552 * All options from multiple RAs with the same or different 553 * source addresses on a single interface will be gathered and 554 * handled, not overridden. [RFC 4861 6.3.4] 555 */ 556 TAILQ_FOREACH(rai, &ifi->ifi_rainfo, rai_next) { 557 TAILQ_FOREACH(rao, &rai->rai_ra_opt, rao_next) { 558 switch (rao->rao_type) { 559 case ND_OPT_RDNSS: 560 if (TS_CMP(&now, &rao->rao_expire, >)) { 561 warnmsg(LOG_INFO, __func__, 562 "expired rdnss entry: %s", 563 (char *)rao->rao_msg); 564 break; 565 } 566 ELM_MALLOC(smp1, continue); 567 ELM_MALLOC(smp2, goto free1); 568 ELM_MALLOC(smp3, goto free2); 569 smp1->sm_msg = resstr_ns_prefix; 570 TAILQ_INSERT_TAIL(&sm_rdnss_head, smp1, 571 sm_next); 572 smp2->sm_msg = rao->rao_msg; 573 TAILQ_INSERT_TAIL(&sm_rdnss_head, smp2, 574 sm_next); 575 smp3->sm_msg = resstr_nl; 576 TAILQ_INSERT_TAIL(&sm_rdnss_head, smp3, 577 sm_next); 578 ifi->ifi_rdnss = IFI_DNSOPT_STATE_RECEIVED; 579 break; 580 case ND_OPT_DNSSL: 581 if (TS_CMP(&now, &rao->rao_expire, >)) { 582 warnmsg(LOG_INFO, __func__, 583 "expired dnssl entry: %s", 584 (char *)rao->rao_msg); 585 break; 586 } 587 dcount++; 588 /* Check resolv.conf(5) restrictions. */ 589 if (dcount > 6) { 590 warnmsg(LOG_INFO, __func__, 591 "dnssl entry exceeding maximum count (%d>6)" 592 ": %s", dcount, (char *)rao->rao_msg); 593 break; 594 } 595 if (256 < dlen + strlen(rao->rao_msg) + 596 strlen(resstr_sp)) { 597 warnmsg(LOG_INFO, __func__, 598 "dnssl entry exceeding maximum length " 599 "(>256): %s", (char *)rao->rao_msg); 600 break; 601 } 602 ELM_MALLOC(smp1, continue); 603 ELM_MALLOC(smp2, goto free1); 604 if (TAILQ_EMPTY(&sm_dnssl_head)) { 605 ELM_MALLOC(smp3, goto free2); 606 smp3->sm_msg = resstr_sh_prefix; 607 TAILQ_INSERT_TAIL(&sm_dnssl_head, smp3, 608 sm_next); 609 } 610 smp1->sm_msg = rao->rao_msg; 611 TAILQ_INSERT_TAIL(&sm_dnssl_head, smp1, 612 sm_next); 613 smp2->sm_msg = resstr_sp; 614 TAILQ_INSERT_TAIL(&sm_dnssl_head, smp2, 615 sm_next); 616 dlen += strlen(rao->rao_msg) + 617 strlen(resstr_sp); 618 ifi->ifi_dnssl = IFI_DNSOPT_STATE_RECEIVED; 619 break; 620 } 621 continue; 622free2: 623 free(smp2); 624free1: 625 free(smp1); 626 } 627 /* Call the script for each information source. */ 628 if (uflag) 629 ra_opt_rdnss_dispatch(ifi, rai, &sm_rdnss_head, 630 &sm_dnssl_head); 631 } 632 /* Call the script for each interface. */ 633 if (!uflag) 634 ra_opt_rdnss_dispatch(ifi, NULL, &sm_rdnss_head, 635 &sm_dnssl_head); 636 return (0); 637} 638 639char * 640make_rsid(const char *ifname, const char *origin, struct rainfo *rai) 641{ 642 char hbuf[NI_MAXHOST]; 643 644 if (rai == NULL) 645 sprintf(rsid, "%s:%s", ifname, origin); 646 else { 647 if (!IN6_IS_ADDR_LINKLOCAL(&rai->rai_saddr.sin6_addr)) 648 return (NULL); 649 if (getnameinfo((struct sockaddr *)&rai->rai_saddr, 650 rai->rai_saddr.sin6_len, hbuf, sizeof(hbuf), NULL, 0, 651 NI_NUMERICHOST) != 0) 652 return (NULL); 653 sprintf(rsid, "%s:%s:[%s]", ifname, origin, hbuf); 654 } 655 warnmsg(LOG_DEBUG, __func__, "rsid = [%s]", rsid); 656 return (rsid); 657} 658 659int 660ra_opt_rdnss_dispatch(struct ifinfo *ifi, struct rainfo *rai, 661 struct script_msg_head_t *sm_rdnss_head, 662 struct script_msg_head_t *sm_dnssl_head) 663{ 664 struct script_msg *smp1; 665 const char *r; 666 int error; 667 668 error = 0; 669 /* Add \n for DNSSL list. */ 670 if (!TAILQ_EMPTY(sm_dnssl_head)) { 671 ELM_MALLOC(smp1, goto ra_opt_rdnss_freeit); 672 smp1->sm_msg = resstr_nl; 673 TAILQ_INSERT_TAIL(sm_dnssl_head, smp1, sm_next); 674 } 675 TAILQ_CONCAT(sm_rdnss_head, sm_dnssl_head, sm_next); 676 677 r = make_rsid(ifi->ifname, DNSINFO_ORIGIN_LABEL, uflag ? rai : NULL); 678 if (r == NULL) { 679 warnmsg(LOG_ERR, __func__, "make_rsid() failed. " 680 "Script was not invoked."); 681 error = 1; 682 goto ra_opt_rdnss_freeit; 683 } 684 if (!TAILQ_EMPTY(sm_rdnss_head)) 685 CALL_SCRIPT(RESADD, sm_rdnss_head); 686 else if (ifi->ifi_rdnss == IFI_DNSOPT_STATE_RECEIVED || 687 ifi->ifi_dnssl == IFI_DNSOPT_STATE_RECEIVED) { 688 CALL_SCRIPT(RESDEL, NULL); 689 ifi->ifi_rdnss = IFI_DNSOPT_STATE_NOINFO; 690 ifi->ifi_dnssl = IFI_DNSOPT_STATE_NOINFO; 691 } 692 693ra_opt_rdnss_freeit: 694 /* Clear script message queue. */ 695 if (!TAILQ_EMPTY(sm_rdnss_head)) { 696 while ((smp1 = TAILQ_FIRST(sm_rdnss_head)) != NULL) { 697 TAILQ_REMOVE(sm_rdnss_head, smp1, sm_next); 698 free(smp1); 699 } 700 } 701 if (!TAILQ_EMPTY(sm_dnssl_head)) { 702 while ((smp1 = TAILQ_FIRST(sm_dnssl_head)) != NULL) { 703 TAILQ_REMOVE(sm_dnssl_head, smp1, sm_next); 704 free(smp1); 705 } 706 } 707 return (error); 708} 709 710static struct ra_opt * 711find_raopt(struct rainfo *rai, int type, void *msg, size_t len) 712{ 713 struct ra_opt *rao; 714 715 TAILQ_FOREACH(rao, &rai->rai_ra_opt, rao_next) { 716 if (rao->rao_type == type && 717 rao->rao_len == strlen(msg) && 718 memcmp(rao->rao_msg, msg, len) == 0) 719 break; 720 } 721 722 return (rao); 723} 724 725static void 726call_script(const char *const argv[], struct script_msg_head_t *sm_head) 727{ 728 struct script_msg *smp; 729 ssize_t len; 730 int status, wfd; 731 732 if (argv[0] == NULL) 733 return; 734 735 wfd = cap_script_run(capscript, argv); 736 if (wfd == -1) { 737 warnmsg(LOG_ERR, __func__, 738 "failed to run %s: %s", argv[0], strerror(errno)); 739 return; 740 } 741 742 if (sm_head != NULL) { 743 TAILQ_FOREACH(smp, sm_head, sm_next) { 744 len = strlen(smp->sm_msg); 745 warnmsg(LOG_DEBUG, __func__, "write to child = %s(%zd)", 746 smp->sm_msg, len); 747 if (write(wfd, smp->sm_msg, len) != len) { 748 warnmsg(LOG_ERR, __func__, 749 "write to child failed: %s", 750 strerror(errno)); 751 break; 752 } 753 } 754 } 755 756 (void)close(wfd); 757 758 if (cap_script_wait(capscript, &status) != 0) 759 warnmsg(LOG_ERR, __func__, "wait(): %s", strerror(errno)); 760 else 761 warnmsg(LOG_DEBUG, __func__, "script \"%s\" status %d", 762 argv[0], status); 763} 764 765/* Decode domain name label encoding in RFC 1035 Section 3.1 */ 766static size_t 767dname_labeldec(char *dst, size_t dlen, const char *src) 768{ 769 size_t len; 770 const char *src_origin; 771 const char *src_last; 772 const char *dst_origin; 773 774 src_origin = src; 775 src_last = strchr(src, '\0'); 776 dst_origin = dst; 777 memset(dst, '\0', dlen); 778 while ((len = (*src++) & 0x3f) && 779 src + len <= src_last && 780 len + (dst == dst_origin ? 0 : 1) < dlen) { 781 if (dst != dst_origin) { 782 *dst++ = '.'; 783 dlen--; 784 } 785 warnmsg(LOG_DEBUG, __func__, "labellen = %zd", len); 786 memcpy(dst, src, len); 787 src += len; 788 dst += len; 789 dlen -= len; 790 } 791 *dst = '\0'; 792 793 /* 794 * XXX validate that domain name only contains valid characters 795 * for two reasons: 1) correctness, 2) we do not want to pass 796 * possible malicious, unescaped characters like `` to a script 797 * or program that could be exploited that way. 798 */ 799 800 return (src - src_origin); 801} 802