ifwatchd.c revision 1.28
1 /* $NetBSD: ifwatchd.c,v 1.28 2016/09/21 14:46:55 roy Exp $ */ 2 3 /*- 4 * Copyright (c) 2002, 2003 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Martin Husemann <martin (at) NetBSD.org>. 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 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 /* 33 * Define this for special treatment of sys/net/if_spppsubr.c based interfaces. 34 */ 35 #define SPPP_IF_SUPPORT 36 37 #include <sys/types.h> 38 #include <sys/param.h> 39 #include <sys/ioctl.h> 40 #include <sys/socket.h> 41 #include <sys/queue.h> 42 #include <sys/wait.h> 43 #include <net/if.h> 44 #include <net/if_dl.h> 45 #include <net/if_media.h> 46 #ifdef SPPP_IF_SUPPORT 47 #include <net/if_sppp.h> 48 #endif 49 #include <net/route.h> 50 #include <netinet/in.h> 51 #include <arpa/inet.h> 52 53 #include <paths.h> 54 #include <stdio.h> 55 #include <stdlib.h> 56 #include <string.h> 57 #include <unistd.h> 58 #include <netdb.h> 59 #include <err.h> 60 #include <ifaddrs.h> 61 #include <syslog.h> 62 63 enum event { ARRIVAL, DEPARTURE, UP, DOWN, CARRIER, NO_CARRIER }; 64 65 /* local functions */ 66 __dead static void usage(void); 67 static void dispatch(void*, size_t); 68 static void check_addrs(char *cp, int addrs, enum event ev); 69 static void invoke_script(struct sockaddr *sa, struct sockaddr *dst, enum event ev, int ifindex, const char *ifname_hint); 70 static void list_interfaces(const char *ifnames); 71 static void check_announce(struct if_announcemsghdr *ifan); 72 static void check_carrier(int if_index, int carrier); 73 static void rescan_interfaces(void); 74 static void free_interfaces(void); 75 static int find_interface(int index); 76 static void run_initial_ups(void); 77 78 #ifdef SPPP_IF_SUPPORT 79 static int check_is_connected(const char * ifname, int def_retvalue); 80 #define if_is_connected(X) (check_is_connected((X), 1)) 81 #define if_is_not_connected(X) (!check_is_connected((X), 0)) 82 #else 83 #define if_is_connected(X) 1 84 #define if_is_not_connected(X) 1 85 #endif 86 87 /* global variables */ 88 static int verbose = 0, quiet = 0; 89 static int inhibit_initial = 0; 90 static const char *arrival_script = NULL; 91 static const char *departure_script = NULL; 92 static const char *up_script = NULL; 93 static const char *down_script = NULL; 94 static const char *carrier_script = NULL; 95 static const char *no_carrier_script = NULL; 96 static const char DummyTTY[] = _PATH_DEVNULL; 97 static const char DummySpeed[] = "9600"; 98 static const char **scripts[] = { 99 &arrival_script, 100 &departure_script, 101 &up_script, 102 &down_script, 103 &carrier_script, 104 &no_carrier_script 105 }; 106 107 struct interface_data { 108 SLIST_ENTRY(interface_data) next; 109 int index; 110 int last_carrier_status; 111 char * ifname; 112 }; 113 static SLIST_HEAD(,interface_data) ifs = SLIST_HEAD_INITIALIZER(ifs); 114 115 int 116 main(int argc, char **argv) 117 { 118 int c, s, n; 119 int errs = 0; 120 struct msghdr msg; 121 struct iovec iov[1]; 122 char buf[2048]; 123 124 openlog(argv[0], LOG_PID|LOG_CONS, LOG_DAEMON); 125 while ((c = getopt(argc, argv, "qvhic:n:u:d:A:D:")) != -1) { 126 switch (c) { 127 case 'h': 128 usage(); 129 return 0; 130 131 case 'i': 132 inhibit_initial = 1; 133 break; 134 135 case 'v': 136 verbose++; 137 break; 138 139 case 'q': 140 quiet = 1; 141 break; 142 143 case 'c': 144 carrier_script = optarg; 145 break; 146 147 case 'n': 148 no_carrier_script = optarg; 149 break; 150 151 case 'u': 152 up_script = optarg; 153 break; 154 155 case 'd': 156 down_script = optarg; 157 break; 158 159 case 'A': 160 arrival_script = optarg; 161 break; 162 163 case 'D': 164 departure_script = optarg; 165 break; 166 167 default: 168 errs++; 169 break; 170 } 171 } 172 173 if (errs) 174 usage(); 175 176 argv += optind; 177 argc -= optind; 178 179 if (argc <= 0) 180 usage(); 181 182 if (verbose) { 183 printf("up_script: %s\ndown_script: %s\n", 184 up_script, down_script); 185 printf("arrival_script: %s\ndeparture_script: %s\n", 186 arrival_script, departure_script); 187 printf("carrier_script: %s\nno_carrier_script: %s\n", 188 carrier_script, no_carrier_script); 189 printf("verbosity = %d\n", verbose); 190 } 191 192 while (argc > 0) { 193 list_interfaces(argv[0]); 194 argv++; 195 argc--; 196 } 197 198 if (!verbose) 199 daemon(0, 0); 200 201 s = socket(PF_ROUTE, SOCK_RAW, 0); 202 if (s < 0) { 203 syslog(LOG_ERR, "error opening routing socket: %m"); 204 perror("open routing socket"); 205 exit(EXIT_FAILURE); 206 } 207 208 if (!inhibit_initial) 209 run_initial_ups(); 210 211 iov[0].iov_base = buf; 212 iov[0].iov_len = sizeof(buf); 213 memset(&msg, 0, sizeof(msg)); 214 msg.msg_iov = iov; 215 msg.msg_iovlen = 1; 216 217 for (;;) { 218 n = recvmsg(s, &msg, 0); 219 if (n == -1) { 220 syslog(LOG_ERR, "recvmsg: %m"); 221 exit(EXIT_FAILURE); 222 } 223 if (n != 0) 224 dispatch(iov[0].iov_base, n); 225 } 226 227 close(s); 228 free_interfaces(); 229 closelog(); 230 231 return EXIT_SUCCESS; 232 } 233 234 static void 235 usage(void) 236 { 237 fprintf(stderr, 238 "usage:\n" 239 "\tifwatchd [-hiqv] [-A arrival-script] [-D departure-script]\n" 240 "\t\t [-d down-script] [-u up-script]\n" 241 "\t\t [-c carrier-script] [-n no-carrier-script] ifname(s)\n" 242 "\twhere:\n" 243 "\t -A <cmd> specify command to run on interface arrival event\n" 244 "\t -c <cmd> specify command to run on interface carrier-detect event\n" 245 "\t -D <cmd> specify command to run on interface departure event\n" 246 "\t -d <cmd> specify command to run on interface down event\n" 247 "\t -n <cmd> specify command to run on interface no-carrier-detect event\n" 248 "\t -h show this help message\n" 249 "\t -i no (!) initial run of the up script if the interface\n" 250 "\t is already up on ifwatchd startup\n" 251 "\t -q quiet mode, don't syslog informational messages\n" 252 "\t -u <cmd> specify command to run on interface up event\n" 253 "\t -v verbose/debug output, don't run in background\n"); 254 exit(EXIT_FAILURE); 255 } 256 257 static void 258 dispatch(void *msg, size_t len) 259 { 260 struct rt_msghdr *hd = msg; 261 struct if_msghdr *ifmp; 262 struct ifa_msghdr *ifam; 263 enum event ev; 264 265 switch (hd->rtm_type) { 266 case RTM_NEWADDR: 267 ev = UP; 268 goto work; 269 case RTM_DELADDR: 270 ev = DOWN; 271 goto work; 272 case RTM_IFANNOUNCE: 273 rescan_interfaces(); 274 check_announce((struct if_announcemsghdr *)msg); 275 return; 276 case RTM_IFINFO: 277 ifmp = (struct if_msghdr*)msg; 278 check_carrier(ifmp->ifm_index, ifmp->ifm_data.ifi_link_state); 279 return; 280 case RTM_ADD: 281 case RTM_DELETE: 282 case RTM_CHANGE: 283 case RTM_LOSING: 284 case RTM_REDIRECT: 285 case RTM_MISS: 286 case RTM_IEEE80211: 287 return; 288 } 289 if (verbose) 290 printf("unknown message ignored (%d)\n", hd->rtm_type); 291 return; 292 293 work: 294 ifam = (struct ifa_msghdr *)msg; 295 check_addrs((char *)(ifam + 1), ifam->ifam_addrs, ev); 296 } 297 298 static void 299 check_addrs(char *cp, int addrs, enum event ev) 300 { 301 struct sockaddr *sa, *ifa = NULL, *brd = NULL; 302 char ifname_buf[IFNAMSIZ]; 303 const char *ifname; 304 int ifndx = 0; 305 unsigned i; 306 307 if (addrs == 0) 308 return; 309 for (i = 1; i; i <<= 1) { 310 if ((i & addrs) == 0) 311 continue; 312 sa = (struct sockaddr *)cp; 313 if (i == RTA_IFP) { 314 struct sockaddr_dl * li = (struct sockaddr_dl*)sa; 315 ifndx = li->sdl_index; 316 if (!find_interface(ifndx)) { 317 if (verbose) 318 printf("ignoring change on interface #%d\n", ifndx); 319 return; 320 } 321 } else if (i == RTA_IFA) 322 ifa = sa; 323 else if (i == RTA_BRD) 324 brd = sa; 325 RT_ADVANCE(cp, sa); 326 } 327 if (ifa != NULL) { 328 ifname = if_indextoname(ifndx, ifname_buf); 329 if (ifname == NULL || ev < UP) 330 invoke_script(ifa, brd, ev, ifndx, ifname); 331 else if (ev == UP) { 332 if (if_is_connected(ifname)) 333 invoke_script(ifa, brd, ev, ifndx, ifname); 334 } else if (ev == DOWN) { 335 if (if_is_not_connected(ifname)) 336 invoke_script(ifa, brd, ev, ifndx, ifname); 337 } 338 } 339 } 340 341 static void 342 invoke_script(struct sockaddr *sa, struct sockaddr *dest, enum event ev, 343 int ifindex, const char *ifname_hint) 344 { 345 char addr[NI_MAXHOST], daddr[NI_MAXHOST], ifname_buf[IFNAMSIZ]; 346 const char * volatile ifname; 347 const char *script; 348 int status; 349 350 if (sa != NULL && sa->sa_len == 0) { 351 fprintf(stderr, "illegal socket address (sa_len == 0)\n"); 352 return; 353 } 354 if (sa != NULL && sa->sa_family == AF_INET6) { 355 struct sockaddr_in6 sin6; 356 357 (void) memcpy(&sin6, (struct sockaddr_in6 *)sa, sizeof (sin6)); 358 if (IN6_IS_ADDR_LINKLOCAL(&sin6.sin6_addr)) 359 return; 360 } 361 362 addr[0] = daddr[0] = 0; 363 ifname = if_indextoname(ifindex, ifname_buf); 364 ifname = ifname ? ifname : ifname_hint; 365 if (ifname == NULL) 366 return; 367 368 if (sa != NULL) { 369 if (getnameinfo(sa, sa->sa_len, addr, sizeof addr, NULL, 0, 370 NI_NUMERICHOST)) { 371 if (verbose) 372 printf("getnameinfo failed\n"); 373 return; /* this address can not be handled */ 374 } 375 } 376 if (dest != NULL) { 377 if (getnameinfo(dest, dest->sa_len, daddr, sizeof daddr, 378 NULL, 0, NI_NUMERICHOST)) { 379 if (verbose) 380 printf("getnameinfo failed\n"); 381 return; /* this address can not be handled */ 382 } 383 } 384 385 script = *scripts[ev]; 386 if (script == NULL) return; 387 388 if (verbose) 389 (void) printf("calling: %s %s %s %s %s %s\n", 390 script, ifname, DummyTTY, DummySpeed, addr, daddr); 391 if (!quiet) 392 syslog(LOG_INFO, "calling: %s %s %s %s %s %s\n", 393 script, ifname, DummyTTY, DummySpeed, addr, daddr); 394 395 switch (vfork()) { 396 case -1: 397 fprintf(stderr, "cannot fork\n"); 398 break; 399 case 0: 400 if (execl(script, script, ifname, DummyTTY, DummySpeed, 401 addr, daddr, NULL) == -1) { 402 syslog(LOG_ERR, "could not execute \"%s\": %m", 403 script); 404 perror(script); 405 } 406 _exit(EXIT_FAILURE); 407 default: 408 (void) wait(&status); 409 } 410 } 411 412 static void 413 list_interfaces(const char *ifnames) 414 { 415 char * names = strdup(ifnames); 416 char * name, *lasts; 417 static const char sep[] = " \t"; 418 struct interface_data * p; 419 420 for (name = strtok_r(names, sep, &lasts); 421 name != NULL; 422 name = strtok_r(NULL, sep, &lasts)) { 423 p = malloc(sizeof(*p)); 424 SLIST_INSERT_HEAD(&ifs, p, next); 425 p->last_carrier_status = -1; 426 p->ifname = strdup(name); 427 p->index = if_nametoindex(p->ifname); 428 if (!quiet) 429 syslog(LOG_INFO, "watching interface %s", p->ifname); 430 if (verbose) 431 printf("interface \"%s\" has index %d\n", 432 p->ifname, p->index); 433 } 434 free(names); 435 } 436 437 static void 438 check_carrier(int if_index, int carrier_status) 439 { 440 struct interface_data * p; 441 enum event ev; 442 443 SLIST_FOREACH(p, &ifs, next) 444 if (p->index == if_index) 445 break; 446 447 if (p == NULL) 448 return; 449 450 /* 451 * Treat it as an event worth handling if: 452 * - the carrier status changed, or 453 * - this is the first time we've been called, and 454 * inhibit_initial is not set 455 */ 456 457 if ((carrier_status != p->last_carrier_status) || 458 ((p->last_carrier_status == -1) && !inhibit_initial)) { 459 switch (carrier_status) { 460 case LINK_STATE_UP: 461 ev = CARRIER; 462 break; 463 case LINK_STATE_DOWN: 464 ev = NO_CARRIER; 465 break; 466 default: 467 if (verbose) 468 printf("unknown link status ignored\n"); 469 return; 470 } 471 invoke_script(NULL, NULL, ev, if_index, p->ifname); 472 p->last_carrier_status = carrier_status; 473 } 474 } 475 476 static void 477 check_announce(struct if_announcemsghdr *ifan) 478 { 479 struct interface_data * p; 480 const char *ifname = ifan->ifan_name; 481 482 SLIST_FOREACH(p, &ifs, next) { 483 if (strcmp(p->ifname, ifname) != 0) 484 continue; 485 486 switch (ifan->ifan_what) { 487 case IFAN_ARRIVAL: 488 invoke_script(NULL, NULL, ARRIVAL, p->index, 489 NULL); 490 break; 491 case IFAN_DEPARTURE: 492 invoke_script(NULL, NULL, DEPARTURE, p->index, 493 p->ifname); 494 break; 495 default: 496 if (verbose) 497 (void) printf("unknown announce: " 498 "what=%d\n", ifan->ifan_what); 499 break; 500 } 501 return; 502 } 503 } 504 505 static void 506 rescan_interfaces(void) 507 { 508 struct interface_data * p; 509 510 SLIST_FOREACH(p, &ifs, next) { 511 p->index = if_nametoindex(p->ifname); 512 if (verbose) 513 printf("interface \"%s\" has index %d\n", p->ifname, 514 p->index); 515 } 516 } 517 518 static void 519 free_interfaces(void) 520 { 521 struct interface_data * p; 522 523 while (!SLIST_EMPTY(&ifs)) { 524 p = SLIST_FIRST(&ifs); 525 SLIST_REMOVE_HEAD(&ifs, next); 526 free(p->ifname); 527 free(p); 528 } 529 } 530 531 static int 532 find_interface(int idx) 533 { 534 struct interface_data * p; 535 536 SLIST_FOREACH(p, &ifs, next) 537 if (p->index == idx) 538 return 1; 539 return 0; 540 } 541 542 static void 543 run_initial_ups(void) 544 { 545 struct interface_data * ifd; 546 struct ifaddrs *res = NULL, *p; 547 int s; 548 549 s = socket(AF_INET, SOCK_DGRAM, 0); 550 if (s < 0) 551 return; 552 553 if (getifaddrs(&res) != 0) 554 goto out; 555 556 for (p = res; p; p = p->ifa_next) { 557 SLIST_FOREACH(ifd, &ifs, next) { 558 if (strcmp(ifd->ifname, p->ifa_name) == 0) 559 break; 560 } 561 if (ifd == NULL) 562 continue; 563 564 if (p->ifa_addr && p->ifa_addr->sa_family == AF_LINK) 565 invoke_script(NULL, NULL, ARRIVAL, ifd->index, 566 NULL); 567 568 if ((p->ifa_flags & IFF_UP) == 0) 569 continue; 570 if (p->ifa_addr == NULL) 571 continue; 572 if (p->ifa_addr->sa_family == AF_LINK) { 573 struct ifmediareq ifmr; 574 575 memset(&ifmr, 0, sizeof(ifmr)); 576 strncpy(ifmr.ifm_name, ifd->ifname, 577 sizeof(ifmr.ifm_name)); 578 if (ioctl(s, SIOCGIFMEDIA, &ifmr) != -1 579 && (ifmr.ifm_status & IFM_AVALID) 580 && (ifmr.ifm_status & IFM_ACTIVE)) { 581 invoke_script(NULL, NULL, CARRIER, 582 ifd->index, ifd->ifname); 583 ifd->last_carrier_status = 584 LINK_STATE_UP; 585 } 586 continue; 587 } 588 if (if_is_connected(ifd->ifname)) 589 invoke_script(p->ifa_addr, p->ifa_dstaddr, UP, 590 ifd->index, ifd->ifname); 591 } 592 freeifaddrs(res); 593 out: 594 close(s); 595 } 596 597 #ifdef SPPP_IF_SUPPORT 598 /* 599 * Special case support for in-kernel PPP interfaces. 600 * If these are IFF_UP, but have not yet connected or completed authentication 601 * we don't want to call the up script in the initial interface scan (there 602 * will be an UP event generated later, when IPCP completes, anyway). 603 * 604 * If this is no if_spppsubr.c based interface, this ioctl just fails and we 605 * treat is as connected. 606 */ 607 static int 608 check_is_connected(const char *ifname, int def_retval) 609 { 610 int s, error; 611 struct spppstatus oldstatus; 612 struct spppstatusncp status; 613 614 memset(&status, 0, sizeof status); 615 strncpy(status.ifname, ifname, sizeof status.ifname); 616 memset(&oldstatus, 0, sizeof oldstatus); 617 strncpy(oldstatus.ifname, ifname, sizeof oldstatus.ifname); 618 619 s = socket(AF_INET, SOCK_DGRAM, 0); 620 if (s < 0) 621 return 1; /* no idea how to handle this... */ 622 error = ioctl(s, SPPPGETSTATUSNCP, &status); 623 if (error != 0) { 624 error = ioctl(s, SPPPGETSTATUS, &oldstatus); 625 if (error != 0) { 626 /* not if_spppsubr.c based - return default */ 627 close(s); 628 return def_retval; 629 } else { 630 /* can't query NCPs, so use default */ 631 status.phase = oldstatus.phase; 632 status.ncpup = def_retval; 633 } 634 } 635 close(s); 636 637 return status.phase == SPPP_PHASE_NETWORK && status.ncpup > 0; 638 } 639 #endif 640
Indexes created Mon Sep 29 21:09:56 GMT 2025