ifwatchd.c revision 1.36
1 /* $NetBSD: ifwatchd.c,v 1.36 2016/09/29 15:25:28 roy Exp $ */ 2 #include <sys/cdefs.h> 3 __RCSID("$NetBSD: ifwatchd.c,v 1.36 2016/09/29 15:25:28 roy Exp $"); 4 5 /*- 6 * Copyright (c) 2002, 2003 The NetBSD Foundation, Inc. 7 * All rights reserved. 8 * 9 * This code is derived from software contributed to The NetBSD Foundation 10 * by Martin Husemann <martin (at) NetBSD.org>. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 22 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 23 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 24 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 25 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 26 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 27 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 28 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 29 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 30 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 31 * POSSIBILITY OF SUCH DAMAGE. 32 */ 33 34 #include <sys/types.h> 35 #include <sys/param.h> 36 #include <sys/ioctl.h> 37 #include <sys/socket.h> 38 #include <sys/queue.h> 39 #include <sys/wait.h> 40 #include <net/if.h> 41 #include <net/if_dl.h> 42 #include <net/if_media.h> 43 #include <net/route.h> 44 #include <netinet/in.h> 45 #include <netinet/in_var.h> 46 #include <arpa/inet.h> 47 48 #include <paths.h> 49 #include <stdio.h> 50 #include <stdlib.h> 51 #include <string.h> 52 #include <unistd.h> 53 #include <netdb.h> 54 #include <err.h> 55 #include <ifaddrs.h> 56 #include <syslog.h> 57 58 enum event { ARRIVAL, DEPARTURE, UP, DOWN, CARRIER, NO_CARRIER }; 59 enum addrflag { NOTREADY, DETACHED, READY }; 60 61 /* local functions */ 62 __dead static void usage(void); 63 static void dispatch(const void *, size_t); 64 static enum addrflag check_addrflags(int af, int addrflags); 65 static void check_addrs(const struct ifa_msghdr *ifam); 66 static void invoke_script(const struct sockaddr *sa, const struct sockaddr *dst, 67 enum event ev, int ifindex, const char *ifname_hint); 68 static void list_interfaces(const char *ifnames); 69 static void check_announce(const struct if_announcemsghdr *ifan); 70 static void check_carrier(const struct if_msghdr *ifm); 71 static void rescan_interfaces(void); 72 static void free_interfaces(void); 73 static struct interface_data * find_interface(int index); 74 static void run_initial_ups(void); 75 76 /* global variables */ 77 static int verbose = 0, quiet = 0; 78 static int inhibit_initial = 0; 79 static const char *arrival_script = NULL; 80 static const char *departure_script = NULL; 81 static const char *up_script = NULL; 82 static const char *down_script = NULL; 83 static const char *carrier_script = NULL; 84 static const char *no_carrier_script = NULL; 85 static const char DummyTTY[] = _PATH_DEVNULL; 86 static const char DummySpeed[] = "9600"; 87 static const char **scripts[] = { 88 &arrival_script, 89 &departure_script, 90 &up_script, 91 &down_script, 92 &carrier_script, 93 &no_carrier_script 94 }; 95 96 struct interface_data { 97 SLIST_ENTRY(interface_data) next; 98 int index; 99 int last_carrier_status; 100 char * ifname; 101 }; 102 static SLIST_HEAD(,interface_data) ifs = SLIST_HEAD_INITIALIZER(ifs); 103 104 int 105 main(int argc, char **argv) 106 { 107 int c, s, n; 108 int errs = 0; 109 struct msghdr msg; 110 struct iovec iov[1]; 111 char buf[2048]; 112 113 openlog(argv[0], LOG_PID|LOG_CONS, LOG_DAEMON); 114 while ((c = getopt(argc, argv, "qvhic:n:u:d:A:D:")) != -1) { 115 switch (c) { 116 case 'h': 117 usage(); 118 return 0; 119 120 case 'i': 121 inhibit_initial = 1; 122 break; 123 124 case 'v': 125 verbose++; 126 break; 127 128 case 'q': 129 quiet = 1; 130 break; 131 132 case 'c': 133 carrier_script = optarg; 134 break; 135 136 case 'n': 137 no_carrier_script = optarg; 138 break; 139 140 case 'u': 141 up_script = optarg; 142 break; 143 144 case 'd': 145 down_script = optarg; 146 break; 147 148 case 'A': 149 arrival_script = optarg; 150 break; 151 152 case 'D': 153 departure_script = optarg; 154 break; 155 156 default: 157 errs++; 158 break; 159 } 160 } 161 162 if (errs) 163 usage(); 164 165 argv += optind; 166 argc -= optind; 167 168 if (argc <= 0) 169 usage(); 170 171 if (verbose) { 172 printf("up_script: %s\ndown_script: %s\n", 173 up_script, down_script); 174 printf("arrival_script: %s\ndeparture_script: %s\n", 175 arrival_script, departure_script); 176 printf("carrier_script: %s\nno_carrier_script: %s\n", 177 carrier_script, no_carrier_script); 178 printf("verbosity = %d\n", verbose); 179 } 180 181 while (argc > 0) { 182 list_interfaces(argv[0]); 183 argv++; 184 argc--; 185 } 186 187 if (!verbose) 188 daemon(0, 0); 189 190 s = socket(PF_ROUTE, SOCK_RAW, 0); 191 if (s < 0) { 192 syslog(LOG_ERR, "error opening routing socket: %m"); 193 perror("open routing socket"); 194 exit(EXIT_FAILURE); 195 } 196 197 if (!inhibit_initial) 198 run_initial_ups(); 199 200 iov[0].iov_base = buf; 201 iov[0].iov_len = sizeof(buf); 202 memset(&msg, 0, sizeof(msg)); 203 msg.msg_iov = iov; 204 msg.msg_iovlen = 1; 205 206 for (;;) { 207 n = recvmsg(s, &msg, 0); 208 if (n == -1) { 209 syslog(LOG_ERR, "recvmsg: %m"); 210 exit(EXIT_FAILURE); 211 } 212 if (n != 0) 213 dispatch(iov[0].iov_base, n); 214 } 215 216 close(s); 217 free_interfaces(); 218 closelog(); 219 220 return EXIT_SUCCESS; 221 } 222 223 static void 224 usage(void) 225 { 226 fprintf(stderr, 227 "usage:\n" 228 "\tifwatchd [-hiqv] [-A arrival-script] [-D departure-script]\n" 229 "\t\t [-d down-script] [-u up-script]\n" 230 "\t\t [-c carrier-script] [-n no-carrier-script] ifname(s)\n" 231 "\twhere:\n" 232 "\t -A <cmd> specify command to run on interface arrival event\n" 233 "\t -c <cmd> specify command to run on interface carrier-detect event\n" 234 "\t -D <cmd> specify command to run on interface departure event\n" 235 "\t -d <cmd> specify command to run on interface down event\n" 236 "\t -n <cmd> specify command to run on interface no-carrier-detect event\n" 237 "\t -h show this help message\n" 238 "\t -i no (!) initial run of the up script if the interface\n" 239 "\t is already up on ifwatchd startup\n" 240 "\t -q quiet mode, don't syslog informational messages\n" 241 "\t -u <cmd> specify command to run on interface up event\n" 242 "\t -v verbose/debug output, don't run in background\n"); 243 exit(EXIT_FAILURE); 244 } 245 246 static void 247 dispatch(const void *msg, size_t len) 248 { 249 const struct rt_msghdr *hd = msg; 250 251 if (hd->rtm_version != RTM_VERSION) 252 return; 253 254 switch (hd->rtm_type) { 255 case RTM_NEWADDR: 256 case RTM_DELADDR: 257 check_addrs(msg); 258 break; 259 case RTM_IFANNOUNCE: 260 rescan_interfaces(); 261 check_announce(msg); 262 break; 263 case RTM_IFINFO: 264 check_carrier(msg); 265 break; 266 case RTM_ADD: 267 case RTM_DELETE: 268 case RTM_CHANGE: 269 case RTM_LOSING: 270 case RTM_REDIRECT: 271 case RTM_MISS: 272 case RTM_IEEE80211: 273 case RTM_ONEWADDR: 274 case RTM_ODELADDR: 275 case RTM_OCHGADDR: 276 break; 277 default: 278 if (verbose) 279 printf("unknown message ignored (%d)\n", hd->rtm_type); 280 break; 281 } 282 } 283 284 static enum addrflag 285 check_addrflags(int af, int addrflags) 286 { 287 288 switch (af) { 289 case AF_INET: 290 if (addrflags & IN_IFF_NOTREADY) 291 return NOTREADY; 292 if (addrflags & IN_IFF_DETACHED) 293 return DETACHED; 294 break; 295 case AF_INET6: 296 if (addrflags & IN6_IFF_NOTREADY) 297 return NOTREADY; 298 if (addrflags & IN6_IFF_DETACHED) 299 return DETACHED; 300 break; 301 } 302 return READY; 303 } 304 305 static void 306 check_addrs(const struct ifa_msghdr *ifam) 307 { 308 const char *cp = (const char *)(ifam + 1); 309 const struct sockaddr *sa, *ifa = NULL, *brd = NULL; 310 unsigned i; 311 struct interface_data *ifd = NULL; 312 int aflag; 313 enum event ev; 314 315 if (ifam->ifam_addrs == 0) 316 return; 317 for (i = 1; i; i <<= 1) { 318 if ((i & ifam->ifam_addrs) == 0) 319 continue; 320 sa = (const struct sockaddr *)cp; 321 if (i == RTA_IFP) { 322 const struct sockaddr_dl *li; 323 324 li = (const struct sockaddr_dl *)sa; 325 if ((ifd = find_interface(li->sdl_index)) == NULL) { 326 if (verbose) 327 printf("ignoring change" 328 " on interface #%d\n", 329 li->sdl_index); 330 return; 331 } 332 } else if (i == RTA_IFA) 333 ifa = sa; 334 else if (i == RTA_BRD) 335 brd = sa; 336 RT_ADVANCE(cp, sa); 337 } 338 if (ifa != NULL && ifd != NULL) { 339 ev = ifam->ifam_type == RTM_DELADDR ? DOWN : UP; 340 aflag = check_addrflags(ifa->sa_family, ifam->ifam_addrflags); 341 if (ev == UP) { 342 if (aflag == NOTREADY) 343 return; 344 if (aflag == DETACHED) 345 return; /* XXX set ev to DOWN? */ 346 } 347 if ((ev == UP && aflag == READY) || 348 (ev == DOWN && aflag == DETACHED /* XXX why DETACHED? */)) 349 invoke_script(ifa, brd, ev, ifd->index, ifd->ifname); 350 } 351 } 352 353 static void 354 invoke_script(const struct sockaddr *sa, const struct sockaddr *dest, 355 enum event ev, int ifindex, const char *ifname_hint) 356 { 357 char addr[NI_MAXHOST], daddr[NI_MAXHOST], ifname_buf[IFNAMSIZ]; 358 const char * volatile ifname; 359 const char *script; 360 int status; 361 362 if (sa != NULL) { 363 if (sa->sa_len == 0) { 364 fprintf(stderr, 365 "illegal socket address (sa_len == 0)\n"); 366 return; 367 } 368 switch (sa->sa_family) { 369 case AF_INET: 370 { 371 const struct sockaddr_in *sin; 372 373 sin = (const struct sockaddr_in *)sa; 374 if (sin->sin_addr.s_addr == INADDR_ANY || 375 sin->sin_addr.s_addr == INADDR_BROADCAST) 376 return; 377 } 378 case AF_INET6: 379 { 380 const struct sockaddr_in6 *sin6; 381 382 sin6 = (const struct sockaddr_in6 *)sa; 383 if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) 384 return; 385 } 386 } 387 } 388 389 addr[0] = daddr[0] = 0; 390 ifname = if_indextoname(ifindex, ifname_buf); 391 ifname = ifname ? ifname : ifname_hint; 392 if (ifname == NULL) 393 return; 394 395 if (sa != NULL) { 396 if (getnameinfo(sa, sa->sa_len, addr, sizeof addr, NULL, 0, 397 NI_NUMERICHOST)) { 398 if (verbose) 399 printf("getnameinfo failed\n"); 400 return; /* this address can not be handled */ 401 } 402 } 403 if (dest != NULL) { 404 if (getnameinfo(dest, dest->sa_len, daddr, sizeof daddr, 405 NULL, 0, NI_NUMERICHOST)) { 406 if (verbose) 407 printf("getnameinfo failed\n"); 408 return; /* this address can not be handled */ 409 } 410 } 411 412 script = *scripts[ev]; 413 if (script == NULL) return; 414 415 if (verbose) 416 (void) printf("calling: %s %s %s %s %s %s\n", 417 script, ifname, DummyTTY, DummySpeed, addr, daddr); 418 if (!quiet) 419 syslog(LOG_INFO, "calling: %s %s %s %s %s %s\n", 420 script, ifname, DummyTTY, DummySpeed, addr, daddr); 421 422 switch (vfork()) { 423 case -1: 424 fprintf(stderr, "cannot fork\n"); 425 break; 426 case 0: 427 if (execl(script, script, ifname, DummyTTY, DummySpeed, 428 addr, daddr, NULL) == -1) { 429 syslog(LOG_ERR, "could not execute \"%s\": %m", 430 script); 431 perror(script); 432 } 433 _exit(EXIT_FAILURE); 434 default: 435 (void) wait(&status); 436 } 437 } 438 439 static void 440 list_interfaces(const char *ifnames) 441 { 442 char * names = strdup(ifnames); 443 char * name, *lasts; 444 static const char sep[] = " \t"; 445 struct interface_data * p; 446 447 for (name = strtok_r(names, sep, &lasts); 448 name != NULL; 449 name = strtok_r(NULL, sep, &lasts)) { 450 p = malloc(sizeof(*p)); 451 SLIST_INSERT_HEAD(&ifs, p, next); 452 p->last_carrier_status = -1; 453 p->ifname = strdup(name); 454 p->index = if_nametoindex(p->ifname); 455 if (!quiet) 456 syslog(LOG_INFO, "watching interface %s", p->ifname); 457 if (verbose) 458 printf("interface \"%s\" has index %d\n", 459 p->ifname, p->index); 460 } 461 free(names); 462 } 463 464 static void 465 check_carrier(const struct if_msghdr *ifm) 466 { 467 struct interface_data * p; 468 int carrier_status; 469 enum event ev; 470 471 SLIST_FOREACH(p, &ifs, next) 472 if (p->index == ifm->ifm_index) 473 break; 474 475 if (p == NULL) 476 return; 477 478 /* 479 * Treat it as an event worth handling if: 480 * - the carrier status changed, or 481 * - this is the first time we've been called, and 482 * inhibit_initial is not set 483 */ 484 carrier_status = ifm->ifm_data.ifi_link_state; 485 if ((carrier_status != p->last_carrier_status) || 486 ((p->last_carrier_status == -1) && !inhibit_initial)) { 487 switch (carrier_status) { 488 case LINK_STATE_UP: 489 ev = CARRIER; 490 break; 491 case LINK_STATE_DOWN: 492 ev = NO_CARRIER; 493 break; 494 default: 495 if (verbose) 496 printf("unknown link status ignored\n"); 497 return; 498 } 499 invoke_script(NULL, NULL, ev, ifm->ifm_index, p->ifname); 500 p->last_carrier_status = carrier_status; 501 } 502 } 503 504 static void 505 check_announce(const struct if_announcemsghdr *ifan) 506 { 507 struct interface_data * p; 508 const char *ifname = ifan->ifan_name; 509 510 SLIST_FOREACH(p, &ifs, next) { 511 if (strcmp(p->ifname, ifname) != 0) 512 continue; 513 514 switch (ifan->ifan_what) { 515 case IFAN_ARRIVAL: 516 invoke_script(NULL, NULL, ARRIVAL, p->index, 517 NULL); 518 break; 519 case IFAN_DEPARTURE: 520 invoke_script(NULL, NULL, DEPARTURE, p->index, 521 p->ifname); 522 break; 523 default: 524 if (verbose) 525 (void) printf("unknown announce: " 526 "what=%d\n", ifan->ifan_what); 527 break; 528 } 529 return; 530 } 531 } 532 533 static void 534 rescan_interfaces(void) 535 { 536 struct interface_data * p; 537 538 SLIST_FOREACH(p, &ifs, next) { 539 p->index = if_nametoindex(p->ifname); 540 if (verbose) 541 printf("interface \"%s\" has index %d\n", p->ifname, 542 p->index); 543 } 544 } 545 546 static void 547 free_interfaces(void) 548 { 549 struct interface_data * p; 550 551 while (!SLIST_EMPTY(&ifs)) { 552 p = SLIST_FIRST(&ifs); 553 SLIST_REMOVE_HEAD(&ifs, next); 554 free(p->ifname); 555 free(p); 556 } 557 } 558 559 static struct interface_data * 560 find_interface(int idx) 561 { 562 struct interface_data * p; 563 564 SLIST_FOREACH(p, &ifs, next) 565 if (p->index == idx) 566 return p; 567 return NULL; 568 } 569 570 static void 571 run_initial_ups(void) 572 { 573 struct interface_data * ifd; 574 struct ifaddrs *res = NULL, *p; 575 struct sockaddr *ifa; 576 int s, aflag; 577 578 s = socket(AF_INET, SOCK_DGRAM, 0); 579 if (s < 0) 580 return; 581 582 if (getifaddrs(&res) != 0) 583 goto out; 584 585 for (p = res; p; p = p->ifa_next) { 586 SLIST_FOREACH(ifd, &ifs, next) { 587 if (strcmp(ifd->ifname, p->ifa_name) == 0) 588 break; 589 } 590 if (ifd == NULL) 591 continue; 592 593 ifa = p->ifa_addr; 594 if (ifa != NULL && ifa->sa_family == AF_LINK) 595 invoke_script(NULL, NULL, ARRIVAL, ifd->index, 596 NULL); 597 598 if ((p->ifa_flags & IFF_UP) == 0) 599 continue; 600 if (ifa == NULL) 601 continue; 602 if (ifa->sa_family == AF_LINK) { 603 struct ifmediareq ifmr; 604 605 memset(&ifmr, 0, sizeof(ifmr)); 606 strncpy(ifmr.ifm_name, ifd->ifname, 607 sizeof(ifmr.ifm_name)); 608 if (ioctl(s, SIOCGIFMEDIA, &ifmr) != -1 609 && (ifmr.ifm_status & IFM_AVALID) 610 && (ifmr.ifm_status & IFM_ACTIVE)) { 611 invoke_script(NULL, NULL, CARRIER, 612 ifd->index, ifd->ifname); 613 ifd->last_carrier_status = 614 LINK_STATE_UP; 615 } 616 continue; 617 } 618 aflag = check_addrflags(ifa->sa_family, p->ifa_addrflags); 619 if (aflag != READY) 620 continue; 621 invoke_script(ifa, p->ifa_dstaddr, UP, ifd->index, ifd->ifname); 622 } 623 freeifaddrs(res); 624 out: 625 close(s); 626 } 627
Indexes created Mon Sep 29 15:09:53 GMT 2025