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/socket.h> 39 #include <sys/uio.h> 40 #include <sys/queue.h> 41 #include <sys/wait.h> 42 #include <sys/stat.h> 43 44 #include <net/if.h> 45 #include <net/route.h> 46 #include <net/if_dl.h> 47 48 #define __BSD_VISIBLE 1 /* IN6ADDR_LINKLOCAL_ALLROUTERS_INIT */ 49 #include <netinet/in.h> 50 #undef __BSD_VISIBLE 51 #include <netinet/ip6.h> 52 #include <netinet6/ip6_var.h> 53 #include <netinet/icmp6.h> 54 55 #include <arpa/inet.h> 56 57 #include <netdb.h> 58 #include <time.h> 59 #include <fcntl.h> 60 #include <unistd.h> 61 #include <stdio.h> 62 #include <time.h> 63 #include <err.h> 64 #include <errno.h> 65 #include <string.h> 66 #include <stdlib.h> 67 #include <syslog.h> 68 #include "rtsold.h" 69 70 static struct msghdr rcvmhdr; 71 static struct msghdr sndmhdr; 72 static struct iovec rcviov[2]; 73 static struct iovec sndiov[2]; 74 static struct sockaddr_in6 from; 75 static int rcvcmsglen; 76 77 int rssock; 78 static char rsid[IFNAMSIZ + 1 + sizeof(DNSINFO_ORIGIN_LABEL) + 1 + NI_MAXHOST]; 79 struct ifinfo_head_t ifinfo_head = 80 TAILQ_HEAD_INITIALIZER(ifinfo_head); 81 82 static const struct sockaddr_in6 sin6_allrouters = { 83 .sin6_len = sizeof(sin6_allrouters), 84 .sin6_family = AF_INET6, 85 .sin6_addr = IN6ADDR_LINKLOCAL_ALLROUTERS_INIT, 86 }; 87 88 static void call_script(const int, const char *const *, 89 struct script_msg_head_t *); 90 static size_t dname_labeldec(char *, size_t, const char *); 91 static int safefile(const char *); 92 static struct ra_opt *find_raopt(struct rainfo *, int, void *, size_t); 93 static int ra_opt_rdnss_dispatch(struct ifinfo *, struct rainfo *, 94 struct script_msg_head_t *, struct script_msg_head_t *); 95 static char *make_rsid(const char *, const char *, struct rainfo *); 96 97 #define _ARGS_OTHER otherconf_script, ifi->ifname 98 #define _ARGS_RESADD resolvconf_script, "-a", rsid 99 #define _ARGS_RESDEL resolvconf_script, "-d", rsid 100 101 #define CALL_SCRIPT(name, sm_head) \ 102 do { \ 103 const char *const sarg[] = { _ARGS_##name, NULL }; \ 104 call_script(sizeof(sarg), sarg, sm_head); \ 105 } while(0) 106 107 #define ELM_MALLOC(p,error_action) \ 108 do { \ 109 p = malloc(sizeof(*p)); \ 110 if (p == NULL) { \ 111 warnmsg(LOG_ERR, __func__, "malloc failed: %s", \ 112 strerror(errno)); \ 113 error_action; \ 114 } \ 115 memset(p, 0, sizeof(*p)); \ 116 } while(0) 117 118 int 119 sockopen(void) 120 { 121 static u_char *rcvcmsgbuf = NULL, *sndcmsgbuf = NULL; 122 int sndcmsglen, on; 123 static u_char answer[1500]; 124 struct icmp6_filter filt; 125 126 sndcmsglen = rcvcmsglen = CMSG_SPACE(sizeof(struct in6_pktinfo)) + 127 CMSG_SPACE(sizeof(int)); 128 if (rcvcmsgbuf == NULL && (rcvcmsgbuf = malloc(rcvcmsglen)) == NULL) { 129 warnmsg(LOG_ERR, __func__, 130 "malloc for receive msghdr failed"); 131 return (-1); 132 } 133 if (sndcmsgbuf == NULL && (sndcmsgbuf = malloc(sndcmsglen)) == NULL) { 134 warnmsg(LOG_ERR, __func__, 135 "malloc for send msghdr failed"); 136 return (-1); 137 } 138 if ((rssock = socket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6)) < 0) { 139 warnmsg(LOG_ERR, __func__, "socket: %s", strerror(errno)); 140 return (-1); 141 } 142 143 /* specify to tell receiving interface */ 144 on = 1; 145 if (setsockopt(rssock, IPPROTO_IPV6, IPV6_RECVPKTINFO, &on, 146 sizeof(on)) < 0) { 147 warnmsg(LOG_ERR, __func__, "IPV6_RECVPKTINFO: %s", 148 strerror(errno)); 149 exit(1); 150 } 151 152 /* specify to tell value of hoplimit field of received IP6 hdr */ 153 on = 1; 154 if (setsockopt(rssock, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &on, 155 sizeof(on)) < 0) { 156 warnmsg(LOG_ERR, __func__, "IPV6_RECVHOPLIMIT: %s", 157 strerror(errno)); 158 exit(1); 159 } 160 161 /* specfiy to accept only router advertisements on the socket */ 162 ICMP6_FILTER_SETBLOCKALL(&filt); 163 ICMP6_FILTER_SETPASS(ND_ROUTER_ADVERT, &filt); 164 if (setsockopt(rssock, IPPROTO_ICMPV6, ICMP6_FILTER, &filt, 165 sizeof(filt)) == -1) { 166 warnmsg(LOG_ERR, __func__, "setsockopt(ICMP6_FILTER): %s", 167 strerror(errno)); 168 return(-1); 169 } 170 171 /* initialize msghdr for receiving packets */ 172 rcviov[0].iov_base = (caddr_t)answer; 173 rcviov[0].iov_len = sizeof(answer); 174 rcvmhdr.msg_name = (caddr_t)&from; 175 rcvmhdr.msg_iov = rcviov; 176 rcvmhdr.msg_iovlen = 1; 177 rcvmhdr.msg_control = (caddr_t) rcvcmsgbuf; 178 179 /* initialize msghdr for sending packets */ 180 sndmhdr.msg_namelen = sizeof(struct sockaddr_in6); 181 sndmhdr.msg_iov = sndiov; 182 sndmhdr.msg_iovlen = 1; 183 sndmhdr.msg_control = (caddr_t)sndcmsgbuf; 184 sndmhdr.msg_controllen = sndcmsglen; 185 186 return (rssock); 187 } 188 189 void 190 sendpacket(struct ifinfo *ifi) 191 { 192 struct in6_pktinfo *pi; 193 struct cmsghdr *cm; 194 int hoplimit = 255; 195 ssize_t i; 196 struct sockaddr_in6 dst; 197 198 dst = sin6_allrouters; 199 dst.sin6_scope_id = ifi->linkid; 200 201 sndmhdr.msg_name = (caddr_t)&dst; 202 sndmhdr.msg_iov[0].iov_base = (caddr_t)ifi->rs_data; 203 sndmhdr.msg_iov[0].iov_len = ifi->rs_datalen; 204 205 cm = CMSG_FIRSTHDR(&sndmhdr); 206 /* specify the outgoing interface */ 207 cm->cmsg_level = IPPROTO_IPV6; 208 cm->cmsg_type = IPV6_PKTINFO; 209 cm->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo)); 210 pi = (struct in6_pktinfo *)(void *)CMSG_DATA(cm); 211 memset(&pi->ipi6_addr, 0, sizeof(pi->ipi6_addr)); /*XXX*/ 212 pi->ipi6_ifindex = ifi->sdl->sdl_index; 213 214 /* specify the hop limit of the packet */ 215 cm = CMSG_NXTHDR(&sndmhdr, cm); 216 cm->cmsg_level = IPPROTO_IPV6; 217 cm->cmsg_type = IPV6_HOPLIMIT; 218 cm->cmsg_len = CMSG_LEN(sizeof(int)); 219 memcpy(CMSG_DATA(cm), &hoplimit, sizeof(int)); 220 221 warnmsg(LOG_DEBUG, __func__, 222 "send RS on %s, whose state is %d", 223 ifi->ifname, ifi->state); 224 i = sendmsg(rssock, &sndmhdr, 0); 225 if (i < 0 || (size_t)i != ifi->rs_datalen) { 226 /* 227 * ENETDOWN is not so serious, especially when using several 228 * network cards on a mobile node. We ignore it. 229 */ 230 if (errno != ENETDOWN || dflag > 0) 231 warnmsg(LOG_ERR, __func__, "sendmsg on %s: %s", 232 ifi->ifname, strerror(errno)); 233 } 234 235 /* update counter */ 236 ifi->probes++; 237 } 238 239 void 240 rtsol_input(int s) 241 { 242 char ntopbuf[INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ]; 243 int l, ifindex = 0, *hlimp = NULL; 244 ssize_t msglen; 245 struct in6_pktinfo *pi = NULL; 246 struct ifinfo *ifi = NULL; 247 struct ra_opt *rao = NULL; 248 struct icmp6_hdr *icp; 249 struct nd_router_advert *nd_ra; 250 struct cmsghdr *cm; 251 struct rainfo *rai; 252 char *raoptp; 253 char *p; 254 struct in6_addr *addr; 255 struct nd_opt_hdr *ndo; 256 struct nd_opt_rdnss *rdnss; 257 struct nd_opt_dnssl *dnssl; 258 size_t len; 259 char nsbuf[INET6_ADDRSTRLEN + 1 + IFNAMSIZ + 1]; 260 char dname[NI_MAXHOST]; 261 struct timespec now; 262 struct timespec lifetime; 263 int newent_rai; 264 int newent_rao; 265 266 /* get message. namelen and controllen must always be initialized. */ 267 rcvmhdr.msg_namelen = sizeof(from); 268 rcvmhdr.msg_controllen = rcvcmsglen; 269 if ((msglen = recvmsg(s, &rcvmhdr, 0)) < 0) { 270 warnmsg(LOG_ERR, __func__, "recvmsg: %s", strerror(errno)); 271 return; 272 } 273 274 /* extract optional information via Advanced API */ 275 for (cm = (struct cmsghdr *)CMSG_FIRSTHDR(&rcvmhdr); cm; 276 cm = (struct cmsghdr *)CMSG_NXTHDR(&rcvmhdr, cm)) { 277 if (cm->cmsg_level == IPPROTO_IPV6 && 278 cm->cmsg_type == IPV6_PKTINFO && 279 cm->cmsg_len == CMSG_LEN(sizeof(struct in6_pktinfo))) { 280 pi = (struct in6_pktinfo *)(void *)(CMSG_DATA(cm)); 281 ifindex = pi->ipi6_ifindex; 282 } 283 if (cm->cmsg_level == IPPROTO_IPV6 && 284 cm->cmsg_type == IPV6_HOPLIMIT && 285 cm->cmsg_len == CMSG_LEN(sizeof(int))) 286 hlimp = (int *)(void *)CMSG_DATA(cm); 287 } 288 289 if (ifindex == 0) { 290 warnmsg(LOG_ERR, __func__, 291 "failed to get receiving interface"); 292 return; 293 } 294 if (hlimp == NULL) { 295 warnmsg(LOG_ERR, __func__, 296 "failed to get receiving hop limit"); 297 return; 298 } 299 300 if ((size_t)msglen < sizeof(struct nd_router_advert)) { 301 warnmsg(LOG_INFO, __func__, 302 "packet size(%zd) is too short", msglen); 303 return; 304 } 305 306 icp = (struct icmp6_hdr *)rcvmhdr.msg_iov[0].iov_base; 307 308 if (icp->icmp6_type != ND_ROUTER_ADVERT) { 309 /* 310 * this should not happen because we configured a filter 311 * that only passes RAs on the receiving socket. 312 */ 313 warnmsg(LOG_ERR, __func__, 314 "invalid icmp type(%d) from %s on %s", icp->icmp6_type, 315 inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf, 316 sizeof(ntopbuf)), 317 if_indextoname(pi->ipi6_ifindex, ifnamebuf)); 318 return; 319 } 320 321 if (icp->icmp6_code != 0) { 322 warnmsg(LOG_INFO, __func__, 323 "invalid icmp code(%d) from %s on %s", icp->icmp6_code, 324 inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf, 325 sizeof(ntopbuf)), 326 if_indextoname(pi->ipi6_ifindex, ifnamebuf)); 327 return; 328 } 329 330 if (*hlimp != 255) { 331 warnmsg(LOG_INFO, __func__, 332 "invalid RA with hop limit(%d) from %s on %s", 333 *hlimp, 334 inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf, 335 sizeof(ntopbuf)), 336 if_indextoname(pi->ipi6_ifindex, ifnamebuf)); 337 return; 338 } 339 340 if (pi && !IN6_IS_ADDR_LINKLOCAL(&from.sin6_addr)) { 341 warnmsg(LOG_INFO, __func__, 342 "invalid RA with non link-local source from %s on %s", 343 inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf, 344 sizeof(ntopbuf)), 345 if_indextoname(pi->ipi6_ifindex, ifnamebuf)); 346 return; 347 } 348 349 /* xxx: more validation? */ 350 351 if ((ifi = find_ifinfo(pi->ipi6_ifindex)) == NULL) { 352 warnmsg(LOG_DEBUG, __func__, 353 "received RA from %s on an unexpected IF(%s)", 354 inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf, 355 sizeof(ntopbuf)), 356 if_indextoname(pi->ipi6_ifindex, ifnamebuf)); 357 return; 358 } 359 360 warnmsg(LOG_DEBUG, __func__, 361 "received RA from %s on %s, state is %d", 362 inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf, sizeof(ntopbuf)), 363 ifi->ifname, ifi->state); 364 365 nd_ra = (struct nd_router_advert *)icp; 366 367 /* 368 * Process the "O bit." 369 * If the value of OtherConfigFlag changes from FALSE to TRUE, the 370 * host should invoke the stateful autoconfiguration protocol, 371 * requesting information. 372 * [RFC 2462 Section 5.5.3] 373 */ 374 if (((nd_ra->nd_ra_flags_reserved) & ND_RA_FLAG_OTHER) && 375 !ifi->otherconfig) { 376 warnmsg(LOG_DEBUG, __func__, 377 "OtherConfigFlag on %s is turned on", ifi->ifname); 378 ifi->otherconfig = 1; 379 CALL_SCRIPT(OTHER, NULL); 380 } 381 clock_gettime(CLOCK_MONOTONIC_FAST, &now); 382 newent_rai = 0; 383 rai = find_rainfo(ifi, &from); 384 if (rai == NULL) { 385 ELM_MALLOC(rai, exit(1)); 386 rai->rai_ifinfo = ifi; 387 TAILQ_INIT(&rai->rai_ra_opt); 388 rai->rai_saddr.sin6_family = AF_INET6; 389 rai->rai_saddr.sin6_len = sizeof(rai->rai_saddr); 390 memcpy(&rai->rai_saddr.sin6_addr, &from.sin6_addr, 391 sizeof(rai->rai_saddr.sin6_addr)); 392 newent_rai = 1; 393 } 394 395 #define RA_OPT_NEXT_HDR(x) (struct nd_opt_hdr *)((char *)x + \ 396 (((struct nd_opt_hdr *)x)->nd_opt_len * 8)) 397 /* Process RA options. */ 398 warnmsg(LOG_DEBUG, __func__, "Processing RA"); 399 raoptp = (char *)icp + sizeof(struct nd_router_advert); 400 while (raoptp < (char *)icp + msglen) { 401 ndo = (struct nd_opt_hdr *)raoptp; 402 warnmsg(LOG_DEBUG, __func__, "ndo = %p", raoptp); 403 warnmsg(LOG_DEBUG, __func__, "ndo->nd_opt_type = %d", 404 ndo->nd_opt_type); 405 warnmsg(LOG_DEBUG, __func__, "ndo->nd_opt_len = %d", 406 ndo->nd_opt_len); 407 408 switch (ndo->nd_opt_type) { 409 case ND_OPT_RDNSS: 410 rdnss = (struct nd_opt_rdnss *)raoptp; 411 412 /* Optlen sanity check (Section 5.3.1 in RFC 6106) */ 413 if (rdnss->nd_opt_rdnss_len < 3) { 414 warnmsg(LOG_INFO, __func__, 415 "too short RDNSS option" 416 "in RA from %s was ignored.", 417 inet_ntop(AF_INET6, &from.sin6_addr, 418 ntopbuf, sizeof(ntopbuf))); 419 break; 420 } 421 422 addr = (struct in6_addr *)(void *)(raoptp + sizeof(*rdnss)); 423 while ((char *)addr < (char *)RA_OPT_NEXT_HDR(raoptp)) { 424 if (inet_ntop(AF_INET6, addr, ntopbuf, 425 sizeof(ntopbuf)) == NULL) { 426 warnmsg(LOG_INFO, __func__, 427 "an invalid address in RDNSS option" 428 " in RA from %s was ignored.", 429 inet_ntop(AF_INET6, &from.sin6_addr, 430 ntopbuf, sizeof(ntopbuf))); 431 addr++; 432 continue; 433 } 434 if (IN6_IS_ADDR_LINKLOCAL(addr)) 435 /* XXX: % has to be escaped here */ 436 l = snprintf(nsbuf, sizeof(nsbuf), 437 "%s%c%s", ntopbuf, 438 SCOPE_DELIMITER, 439 ifi->ifname); 440 else 441 l = snprintf(nsbuf, sizeof(nsbuf), 442 "%s", ntopbuf); 443 if (l < 0 || (size_t)l >= sizeof(nsbuf)) { 444 warnmsg(LOG_ERR, __func__, 445 "address copying error in " 446 "RDNSS option: %d.", l); 447 addr++; 448 continue; 449 } 450 warnmsg(LOG_DEBUG, __func__, "nsbuf = %s", 451 nsbuf); 452 453 newent_rao = 0; 454 rao = find_raopt(rai, ndo->nd_opt_type, nsbuf, 455 strlen(nsbuf)); 456 if (rao == NULL) { 457 ELM_MALLOC(rao, break); 458 rao->rao_type = ndo->nd_opt_type; 459 rao->rao_len = strlen(nsbuf); 460 rao->rao_msg = strdup(nsbuf); 461 if (rao->rao_msg == NULL) { 462 warnmsg(LOG_ERR, __func__, 463 "strdup failed: %s", 464 strerror(errno)); 465 free(rao); 466 addr++; 467 continue; 468 } 469 newent_rao = 1; 470 } 471 /* Set expiration timer */ 472 memset(&rao->rao_expire, 0, 473 sizeof(rao->rao_expire)); 474 memset(&lifetime, 0, sizeof(lifetime)); 475 lifetime.tv_sec = 476 ntohl(rdnss->nd_opt_rdnss_lifetime); 477 TS_ADD(&now, &lifetime, &rao->rao_expire); 478 479 if (newent_rao) 480 TAILQ_INSERT_TAIL(&rai->rai_ra_opt, 481 rao, rao_next); 482 addr++; 483 } 484 break; 485 case ND_OPT_DNSSL: 486 dnssl = (struct nd_opt_dnssl *)raoptp; 487 488 /* Optlen sanity check (Section 5.3.1 in RFC 6106) */ 489 if (dnssl->nd_opt_dnssl_len < 2) { 490 warnmsg(LOG_INFO, __func__, 491 "too short DNSSL option" 492 "in RA from %s was ignored.", 493 inet_ntop(AF_INET6, &from.sin6_addr, 494 ntopbuf, sizeof(ntopbuf))); 495 break; 496 } 497 498 /* 499 * Ensure NUL-termination in DNSSL in case of 500 * malformed field. 501 */ 502 p = (char *)RA_OPT_NEXT_HDR(raoptp); 503 *(p - 1) = '\0'; 504 505 p = raoptp + sizeof(*dnssl); 506 while (1 < (len = dname_labeldec(dname, sizeof(dname), 507 p))) { 508 /* length == 1 means empty string */ 509 warnmsg(LOG_DEBUG, __func__, "dname = %s", 510 dname); 511 512 newent_rao = 0; 513 rao = find_raopt(rai, ndo->nd_opt_type, dname, 514 strlen(dname)); 515 if (rao == NULL) { 516 ELM_MALLOC(rao, break); 517 rao->rao_type = ndo->nd_opt_type; 518 rao->rao_len = strlen(dname); 519 rao->rao_msg = strdup(dname); 520 if (rao->rao_msg == NULL) { 521 warnmsg(LOG_ERR, __func__, 522 "strdup failed: %s", 523 strerror(errno)); 524 free(rao); 525 addr++; 526 continue; 527 } 528 newent_rao = 1; 529 } 530 /* Set expiration timer */ 531 memset(&rao->rao_expire, 0, 532 sizeof(rao->rao_expire)); 533 memset(&lifetime, 0, sizeof(lifetime)); 534 lifetime.tv_sec = 535 ntohl(dnssl->nd_opt_dnssl_lifetime); 536 TS_ADD(&now, &lifetime, &rao->rao_expire); 537 538 if (newent_rao) 539 TAILQ_INSERT_TAIL(&rai->rai_ra_opt, 540 rao, rao_next); 541 p += len; 542 } 543 break; 544 default: 545 /* nothing to do for other options */ 546 break; 547 } 548 raoptp = (char *)RA_OPT_NEXT_HDR(raoptp); 549 } 550 if (newent_rai) 551 TAILQ_INSERT_TAIL(&ifi->ifi_rainfo, rai, rai_next); 552 553 ra_opt_handler(ifi); 554 ifi->racnt++; 555 556 switch (ifi->state) { 557 case IFS_IDLE: /* should be ignored */ 558 case IFS_DELAY: /* right? */ 559 break; 560 case IFS_PROBE: 561 ifi->state = IFS_IDLE; 562 ifi->probes = 0; 563 rtsol_timer_update(ifi); 564 break; 565 } 566 } 567 568 static char resstr_ns_prefix[] = "nameserver "; 569 static char resstr_sh_prefix[] = "search "; 570 static char resstr_nl[] = "\n"; 571 static char resstr_sp[] = " "; 572 573 int 574 ra_opt_handler(struct ifinfo *ifi) 575 { 576 struct ra_opt *rao; 577 struct rainfo *rai; 578 struct script_msg *smp1, *smp2, *smp3; 579 struct timespec now; 580 struct script_msg_head_t sm_rdnss_head = 581 TAILQ_HEAD_INITIALIZER(sm_rdnss_head); 582 struct script_msg_head_t sm_dnssl_head = 583 TAILQ_HEAD_INITIALIZER(sm_dnssl_head); 584 585 int dcount, dlen; 586 587 dcount = 0; 588 dlen = strlen(resstr_sh_prefix) + strlen(resstr_nl); 589 clock_gettime(CLOCK_MONOTONIC_FAST, &now); 590 591 /* 592 * All options from multiple RAs with the same or different 593 * source addresses on a single interface will be gathered and 594 * handled, not overridden. [RFC 4861 6.3.4] 595 */ 596 TAILQ_FOREACH(rai, &ifi->ifi_rainfo, rai_next) { 597 TAILQ_FOREACH(rao, &rai->rai_ra_opt, rao_next) { 598 switch (rao->rao_type) { 599 case ND_OPT_RDNSS: 600 if (TS_CMP(&now, &rao->rao_expire, >)) { 601 warnmsg(LOG_INFO, __func__, 602 "expired rdnss entry: %s", 603 (char *)rao->rao_msg); 604 break; 605 } 606 ELM_MALLOC(smp1, continue); 607 ELM_MALLOC(smp2, goto free1); 608 ELM_MALLOC(smp3, goto free2); 609 smp1->sm_msg = resstr_ns_prefix; 610 TAILQ_INSERT_TAIL(&sm_rdnss_head, smp1, 611 sm_next); 612 smp2->sm_msg = rao->rao_msg; 613 TAILQ_INSERT_TAIL(&sm_rdnss_head, smp2, 614 sm_next); 615 smp3->sm_msg = resstr_nl; 616 TAILQ_INSERT_TAIL(&sm_rdnss_head, smp3, 617 sm_next); 618 ifi->ifi_rdnss = IFI_DNSOPT_STATE_RECEIVED; 619 620 break; 621 case ND_OPT_DNSSL: 622 if (TS_CMP(&now, &rao->rao_expire, >)) { 623 warnmsg(LOG_INFO, __func__, 624 "expired dnssl entry: %s", 625 (char *)rao->rao_msg); 626 break; 627 } 628 dcount++; 629 /* Check resolv.conf(5) restrictions. */ 630 if (dcount > 6) { 631 warnmsg(LOG_INFO, __func__, 632 "dnssl entry exceeding maximum count (%d>6)" 633 ": %s", dcount, (char *)rao->rao_msg); 634 break; 635 } 636 if (256 < dlen + strlen(rao->rao_msg) + 637 strlen(resstr_sp)) { 638 warnmsg(LOG_INFO, __func__, 639 "dnssl entry exceeding maximum length " 640 "(>256): %s", (char *)rao->rao_msg); 641 break; 642 } 643 ELM_MALLOC(smp1, continue); 644 ELM_MALLOC(smp2, goto free1); 645 if (TAILQ_EMPTY(&sm_dnssl_head)) { 646 ELM_MALLOC(smp3, goto free2); 647 smp3->sm_msg = resstr_sh_prefix; 648 TAILQ_INSERT_TAIL(&sm_dnssl_head, smp3, 649 sm_next); 650 } 651 smp1->sm_msg = rao->rao_msg; 652 TAILQ_INSERT_TAIL(&sm_dnssl_head, smp1, 653 sm_next); 654 smp2->sm_msg = resstr_sp; 655 TAILQ_INSERT_TAIL(&sm_dnssl_head, smp2, 656 sm_next); 657 dlen += strlen(rao->rao_msg) + 658 strlen(resstr_sp); 659 break; 660 661 ifi->ifi_dnssl = IFI_DNSOPT_STATE_RECEIVED; 662 default: 663 break; 664 } 665 continue; 666 free2: 667 free(smp2); 668 free1: 669 free(smp1); 670 } 671 /* Call the script for each information source. */ 672 if (uflag) 673 ra_opt_rdnss_dispatch(ifi, rai, &sm_rdnss_head, 674 &sm_dnssl_head); 675 } 676 /* Call the script for each interface. */ 677 if (!uflag) 678 ra_opt_rdnss_dispatch(ifi, NULL, &sm_rdnss_head, 679 &sm_dnssl_head); 680 return (0); 681 } 682 683 char * 684 make_rsid(const char *ifname, const char *origin, struct rainfo *rai) 685 { 686 char hbuf[NI_MAXHOST]; 687 688 if (rai == NULL) 689 sprintf(rsid, "%s:%s", ifname, origin); 690 else { 691 if (!IN6_IS_ADDR_LINKLOCAL(&rai->rai_saddr.sin6_addr)) 692 return (NULL); 693 if (getnameinfo((struct sockaddr *)&rai->rai_saddr, 694 rai->rai_saddr.sin6_len, hbuf, sizeof(hbuf), NULL, 0, 695 NI_NUMERICHOST) != 0) 696 return (NULL); 697 sprintf(rsid, "%s:%s:[%s]", ifname, origin, hbuf); 698 } 699 warnmsg(LOG_DEBUG, __func__, "rsid = [%s]", rsid); 700 return (rsid); 701 } 702 703 int 704 ra_opt_rdnss_dispatch(struct ifinfo *ifi, 705 struct rainfo *rai, 706 struct script_msg_head_t *sm_rdnss_head, 707 struct script_msg_head_t *sm_dnssl_head) 708 { 709 const char *r; 710 struct script_msg *smp1; 711 int error; 712 713 error = 0; 714 /* Add \n for DNSSL list. */ 715 if (!TAILQ_EMPTY(sm_dnssl_head)) { 716 ELM_MALLOC(smp1, goto ra_opt_rdnss_freeit); 717 smp1->sm_msg = resstr_nl; 718 TAILQ_INSERT_TAIL(sm_dnssl_head, smp1, sm_next); 719 } 720 TAILQ_CONCAT(sm_rdnss_head, sm_dnssl_head, sm_next); 721 722 if (rai != NULL && uflag) 723 r = make_rsid(ifi->ifname, DNSINFO_ORIGIN_LABEL, rai); 724 else 725 r = make_rsid(ifi->ifname, DNSINFO_ORIGIN_LABEL, NULL); 726 if (r == NULL) { 727 warnmsg(LOG_ERR, __func__, "make_rsid() failed. " 728 "Script was not invoked."); 729 error = 1; 730 goto ra_opt_rdnss_freeit; 731 } 732 if (!TAILQ_EMPTY(sm_rdnss_head)) 733 CALL_SCRIPT(RESADD, sm_rdnss_head); 734 else if (ifi->ifi_rdnss == IFI_DNSOPT_STATE_RECEIVED || 735 ifi->ifi_dnssl == IFI_DNSOPT_STATE_RECEIVED) { 736 CALL_SCRIPT(RESDEL, NULL); 737 ifi->ifi_rdnss = IFI_DNSOPT_STATE_NOINFO; 738 ifi->ifi_dnssl = IFI_DNSOPT_STATE_NOINFO; 739 } 740 741 ra_opt_rdnss_freeit: 742 /* Clear script message queue. */ 743 if (!TAILQ_EMPTY(sm_rdnss_head)) { 744 while ((smp1 = TAILQ_FIRST(sm_rdnss_head)) != NULL) { 745 TAILQ_REMOVE(sm_rdnss_head, smp1, sm_next); 746 free(smp1); 747 } 748 } 749 if (!TAILQ_EMPTY(sm_dnssl_head)) { 750 while ((smp1 = TAILQ_FIRST(sm_dnssl_head)) != NULL) { 751 TAILQ_REMOVE(sm_dnssl_head, smp1, sm_next); 752 free(smp1); 753 } 754 } 755 return (error); 756 } 757 758 static struct ra_opt * 759 find_raopt(struct rainfo *rai, int type, void *msg, size_t len) 760 { 761 struct ra_opt *rao; 762 763 TAILQ_FOREACH(rao, &rai->rai_ra_opt, rao_next) { 764 if (rao->rao_type == type && 765 rao->rao_len == strlen(msg) && 766 memcmp(rao->rao_msg, msg, len) == 0) 767 break; 768 } 769 770 return (rao); 771 } 772 773 static void 774 call_script(const int argc, const char *const argv[], 775 struct script_msg_head_t *sm_head) 776 { 777 const char *scriptpath; 778 int fd[2]; 779 int error; 780 pid_t pid, wpid; 781 782 if ((scriptpath = argv[0]) == NULL) 783 return; 784 785 fd[0] = fd[1] = -1; 786 if (sm_head != NULL && !TAILQ_EMPTY(sm_head)) { 787 error = pipe(fd); 788 if (error) { 789 warnmsg(LOG_ERR, __func__, 790 "failed to create a pipe: %s", strerror(errno)); 791 return; 792 } 793 } 794 795 /* launch the script */ 796 pid = fork(); 797 if (pid < 0) { 798 warnmsg(LOG_ERR, __func__, 799 "failed to fork: %s", strerror(errno)); 800 return; 801 } else if (pid) { /* parent */ 802 int wstatus; 803 804 if (fd[0] != -1) { /* Send message to the child if any. */ 805 ssize_t len; 806 struct script_msg *smp; 807 808 close(fd[0]); 809 TAILQ_FOREACH(smp, sm_head, sm_next) { 810 len = strlen(smp->sm_msg); 811 warnmsg(LOG_DEBUG, __func__, 812 "write to child = %s(%zd)", 813 smp->sm_msg, len); 814 if (write(fd[1], smp->sm_msg, len) != len) { 815 warnmsg(LOG_ERR, __func__, 816 "write to child failed: %s", 817 strerror(errno)); 818 break; 819 } 820 } 821 close(fd[1]); 822 } 823 do { 824 wpid = wait(&wstatus); 825 } while (wpid != pid && wpid > 0); 826 827 if (wpid < 0) 828 warnmsg(LOG_ERR, __func__, 829 "wait: %s", strerror(errno)); 830 else 831 warnmsg(LOG_DEBUG, __func__, 832 "script \"%s\" terminated", scriptpath); 833 } else { /* child */ 834 int nullfd; 835 char **_argv; 836 837 if (safefile(scriptpath)) { 838 warnmsg(LOG_ERR, __func__, 839 "script \"%s\" cannot be executed safely", 840 scriptpath); 841 exit(1); 842 } 843 nullfd = open("/dev/null", O_RDWR); 844 if (nullfd < 0) { 845 warnmsg(LOG_ERR, __func__, 846 "open /dev/null: %s", strerror(errno)); 847 exit(1); 848 } 849 if (fd[0] != -1) { /* Receive message from STDIN if any. */ 850 close(fd[1]); 851 if (fd[0] != STDIN_FILENO) { 852 /* Connect a pipe read-end to child's STDIN. */ 853 if (dup2(fd[0], STDIN_FILENO) != STDIN_FILENO) { 854 warnmsg(LOG_ERR, __func__, 855 "dup2 STDIN: %s", strerror(errno)); 856 exit(1); 857 } 858 close(fd[0]); 859 } 860 } else 861 dup2(nullfd, STDIN_FILENO); 862 863 dup2(nullfd, STDOUT_FILENO); 864 dup2(nullfd, STDERR_FILENO); 865 if (nullfd > STDERR_FILENO) 866 close(nullfd); 867 868 _argv = malloc(sizeof(*_argv) * argc); 869 if (_argv == NULL) { 870 warnmsg(LOG_ERR, __func__, 871 "malloc: %s", strerror(errno)); 872 exit(1); 873 } 874 memcpy(_argv, argv, (size_t)argc); 875 execv(scriptpath, (char *const *)_argv); 876 warnmsg(LOG_ERR, __func__, "child: exec failed: %s", 877 strerror(errno)); 878 exit(1); 879 } 880 881 return; 882 } 883 884 static int 885 safefile(const char *path) 886 { 887 struct stat s; 888 uid_t myuid; 889 890 /* no setuid */ 891 if (getuid() != geteuid()) { 892 warnmsg(LOG_NOTICE, __func__, 893 "setuid'ed execution not allowed\n"); 894 return (-1); 895 } 896 897 if (lstat(path, &s) != 0) { 898 warnmsg(LOG_NOTICE, __func__, "lstat failed: %s", 899 strerror(errno)); 900 return (-1); 901 } 902 903 /* the file must be owned by the running uid */ 904 myuid = getuid(); 905 if (s.st_uid != myuid) { 906 warnmsg(LOG_NOTICE, __func__, 907 "%s has invalid owner uid\n", path); 908 return (-1); 909 } 910 911 switch (s.st_mode & S_IFMT) { 912 case S_IFREG: 913 break; 914 default: 915 warnmsg(LOG_NOTICE, __func__, 916 "%s is an invalid file type 0x%o\n", 917 path, (s.st_mode & S_IFMT)); 918 return (-1); 919 } 920 921 return (0); 922 } 923 924 /* Decode domain name label encoding in RFC 1035 Section 3.1 */ 925 static size_t 926 dname_labeldec(char *dst, size_t dlen, const char *src) 927 { 928 size_t len; 929 const char *src_origin; 930 const char *src_last; 931 const char *dst_origin; 932 933 src_origin = src; 934 src_last = strchr(src, '\0'); 935 dst_origin = dst; 936 memset(dst, '\0', dlen); 937 while (src && (len = (uint8_t)(*src++) & 0x3f) && 938 (src + len) <= src_last && 939 (dst - dst_origin < (ssize_t)dlen)) { 940 if (dst != dst_origin) 941 *dst++ = '.'; 942 warnmsg(LOG_DEBUG, __func__, "labellen = %zd", len); 943 memcpy(dst, src, len); 944 src += len; 945 dst += len; 946 } 947 *dst = '\0'; 948 949 /* 950 * XXX validate that domain name only contains valid characters 951 * for two reasons: 1) correctness, 2) we do not want to pass 952 * possible malicious, unescaped characters like `` to a script 953 * or program that could be exploited that way. 954 */ 955 956 return (src - src_origin); 957 } 958