udev/udevd.c

   1 /*
   2  * Copyright (C) 2004-2009 Kay Sievers <kay.sievers@vrfy.org>
   3  * Copyright (C) 2004 Chris Friesen <chris_friesen@sympatico.ca>
   4  * Copyright (C) 2009 Canonical Ltd.
   5  * Copyright (C) 2009 Scott James Remnant <scott@netsplit.com>
   6  *
   7  * This program is free software: you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation, either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21 #include <stddef.h>
  22 #include <signal.h>
  23 #include <unistd.h>
  24 #include <errno.h>
  25 #include <stdio.h>
  26 #include <stdlib.h>
  27 #include <string.h>
  28 #include <ctype.h>
  29 #include <fcntl.h>
  30 #include <time.h>
  31 #include <getopt.h>
  32 #include <dirent.h>
  33 #include <sys/prctl.h>
  34 #include <sys/socket.h>
  35 #include <sys/signalfd.h>
  36 #include <sys/select.h>
  37 #include <sys/poll.h>
  38 #include <sys/wait.h>
  39 #include <sys/stat.h>
  40 #include <sys/ioctl.h>
  41 #include <sys/inotify.h>
  42
  43 #include "udev.h"
  44
  45 #define UDEVD_PRIORITY                  -4
  46 #define UDEV_PRIORITY                   -2
  47
  48 static int debug;
  49
  50 static void log_fn(struct udev *udev, int priority,
  51                    const char *file, int line, const char *fn,
  52                    const char *format, va_list args)
  53 {
  54         if (debug) {
  55                 fprintf(stderr, "[%d] %s: ", (int) getpid(), fn);
  56                 vfprintf(stderr, format, args);
  57         } else {
  58                 vsyslog(priority, format, args);
  59         }
  60 }
  61
  62 static int debug_trace;
  63 static struct udev_rules *rules;
  64 static struct udev_queue_export *udev_queue_export;
  65 static struct udev_ctrl *udev_ctrl;
  66 static struct udev_monitor *monitor;
  67 static int worker_watch[2];
  68 static pid_t settle_pid;
  69 static int stop_exec_queue;
  70 static int reload_config;
  71 static int max_childs;
  72 static int childs;
  73 static struct udev_list_node event_list;
  74 static struct udev_list_node worker_list;
  75 static int udev_exit;
  76 static volatile sig_atomic_t worker_exit;
  77
  78 enum poll_fd {
  79         FD_CONTROL,
  80         FD_NETLINK,
  81         FD_INOTIFY,
  82         FD_SIGNAL,
  83         FD_WORKER,
  84 };
  85
  86 static struct pollfd pfd[] = {
  87         [FD_NETLINK] = { .events = POLLIN },
  88         [FD_WORKER] =  { .events = POLLIN },
  89         [FD_SIGNAL] =  { .events = POLLIN },
  90         [FD_INOTIFY] = { .events = POLLIN },
  91         [FD_CONTROL] = { .events = POLLIN },
  92 };
  93
  94 enum event_state {
  95         EVENT_UNDEF,
  96         EVENT_QUEUED,
  97         EVENT_RUNNING,
  98 };
  99
 100 struct event {
 101         struct udev_list_node node;
 102         struct udev *udev;
 103         struct udev_device *dev;
 104         enum event_state state;
 105         int exitcode;
 106         unsigned long long int delaying_seqnum;
 107         unsigned long long int seqnum;
 108         const char *devpath;
 109         size_t devpath_len;
 110         const char *devpath_old;
 111 };
 112
 113 static struct event *node_to_event(struct udev_list_node *node)
 114 {
 115         char *event;
 116
 117         event = (char *)node;
 118         event -= offsetof(struct event, node);
 119         return (struct event *)event;
 120 }
 121
 122 enum worker_state {
 123         WORKER_UNDEF,
 124         WORKER_RUNNING,
 125         WORKER_IDLE,
 126         WORKER_KILLED,
 127 };
 128
 129 struct worker {
 130         struct udev_list_node node;
 131         pid_t pid;
 132         struct udev_monitor *monitor;
 133         enum worker_state state;
 134         struct event *event;
 135 };
 136
 137 /* passed from worker to main process */
 138 struct worker_message {
 139         pid_t pid;
 140         int exitcode;
 141 };
 142
 143 static struct worker *node_to_worker(struct udev_list_node *node)
 144 {
 145         char *worker;
 146
 147         worker = (char *)node;
 148         worker -= offsetof(struct worker, node);
 149         return (struct worker *)worker;
 150 }
 151
 152 static void event_queue_delete(struct event *event)
 153 {
 154         udev_list_node_remove(&event->node);
 155
 156         /* mark as failed, if "add" event returns non-zero */
 157         if (event->exitcode && strcmp(udev_device_get_action(event->dev), "add") == 0)
 158                 udev_queue_export_device_failed(udev_queue_export, event->dev);
 159         else
 160                 udev_queue_export_device_finished(udev_queue_export, event->dev);
 161
 162         udev_device_unref(event->dev);
 163         free(event);
 164 }
 165
 166 static void event_sig_handler(int signum)
 167 {
 168         switch (signum) {
 169         case SIGALRM:
 170                 _exit(1);
 171                 break;
 172         case SIGTERM:
 173                 worker_exit = 1;
 174                 break;
 175         }
 176 }
 177
 178 static void worker_unref(struct worker *worker)
 179 {
 180         udev_monitor_unref(worker->monitor);
 181         free(worker);
 182 }
 183
 184 static void worker_new(struct event *event)
 185 {
 186         struct worker *worker;
 187         struct udev_monitor *worker_monitor;
 188         pid_t pid;
 189         struct sigaction act;
 190
 191         /* listen for new events */
 192         worker_monitor = udev_monitor_new_from_netlink(event->udev, NULL);
 193         if (worker_monitor == NULL)
 194                 return;
 195         /* allow the main daemon netlink address to send devices to the worker */
 196         udev_monitor_allow_unicast_sender(worker_monitor, monitor);
 197         udev_monitor_enable_receiving(worker_monitor);
 198         util_set_fd_cloexec(udev_monitor_get_fd(worker_monitor));
 199
 200         worker = calloc(1, sizeof(struct worker));
 201         if (worker == NULL)
 202                 return;
 203
 204         pid = fork();
 205         switch (pid) {
 206         case 0: {
 207                 sigset_t mask;
 208                 struct udev_device *dev;
 209
 210                 udev_queue_export_unref(udev_queue_export);
 211                 udev_monitor_unref(monitor);
 212                 udev_ctrl_unref(udev_ctrl);
 213                 close(pfd[FD_SIGNAL].fd);
 214                 close(worker_watch[READ_END]);
 215                 logging_close();
 216                 logging_init("udevd-work");
 217                 setpriority(PRIO_PROCESS, 0, UDEV_PRIORITY);
 218
 219                 /* set signal handlers */
 220                 memset(&act, 0x00, sizeof(act));
 221                 act.sa_handler = event_sig_handler;
 222                 sigemptyset (&act.sa_mask);
 223                 act.sa_flags = 0;
 224                 sigaction(SIGTERM, &act, NULL);
 225                 sigaction(SIGALRM, &act, NULL);
 226
 227                 /* unblock signals */
 228                 sigfillset(&mask);
 229                 sigdelset(&mask, SIGTERM);
 230                 sigdelset(&mask, SIGALRM);
 231                 sigprocmask(SIG_SETMASK, &mask, NULL);
 232
 233                 /* request TERM signal if parent exits */
 234                 prctl(PR_SET_PDEATHSIG, SIGTERM);
 235
 236                 /* initial device */
 237                 dev = event->dev;
 238
 239                 while (!worker_exit) {
 240                         struct udev_event *udev_event;
 241                         struct worker_message msg;
 242                         int err;
 243
 244                         udev_event = udev_event_new(dev);
 245                         if (udev_event == NULL)
 246                                 _exit(3);
 247
 248                         /* set timeout to prevent hanging processes */
 249                         alarm(UDEV_EVENT_TIMEOUT);
 250
 251                         /* apply rules, create node, symlinks */
 252                         err = udev_event_execute_rules(udev_event, rules);
 253
 254                         /* rules may change/disable the timeout */
 255                         if (udev_device_get_event_timeout(dev) >= 0)
 256                                 alarm(udev_device_get_event_timeout(dev));
 257
 258                         /* execute RUN= */
 259                         if (err == 0 && !udev_event->ignore_device && udev_get_run(udev_event->udev))
 260                                 udev_event_execute_run(udev_event);
 261
 262                         /* reset alarm */
 263                         alarm(0);
 264
 265                         /* apply/restore inotify watch */
 266                         if (err == 0 && udev_event->inotify_watch) {
 267                                 udev_watch_begin(udev_event->udev, dev);
 268                                 udev_device_update_db(dev);
 269                         }
 270
 271                         /* send processed event back to libudev listeners */
 272                         udev_monitor_send_device(worker_monitor, NULL, dev);
 273
 274                         info(event->udev, "seq %llu finished with %i\n", udev_device_get_seqnum(dev), err);
 275                         udev_device_unref(dev);
 276                         udev_event_unref(udev_event);
 277
 278                         /* send back the result of the event execution */
 279                         msg.exitcode = err;
 280                         msg.pid = getpid();
 281                         send(worker_watch[WRITE_END], &msg, sizeof(struct worker_message), 0);
 282
 283                         /* wait for more device messages from udevd */
 284                         do
 285                                 dev = udev_monitor_receive_device(worker_monitor);
 286                         while (!worker_exit && dev == NULL);
 287                 }
 288
 289                 udev_monitor_unref(worker_monitor);
 290                 logging_close();
 291                 exit(0);
 292         }
 293         case -1:
 294                 udev_monitor_unref(worker_monitor);
 295                 event->state = EVENT_QUEUED;
 296                 free(worker);
 297                 err(event->udev, "fork of child failed: %m\n");
 298                 break;
 299         default:
 300                 /* close monitor, but keep address around */
 301                 udev_monitor_disconnect(worker_monitor);
 302                 worker->monitor = worker_monitor;
 303                 worker->pid = pid;
 304                 worker->state = WORKER_RUNNING;
 305                 worker->event = event;
 306                 event->state = EVENT_RUNNING;
 307                 udev_list_node_append(&worker->node, &worker_list);
 308                 childs++;
 309                 break;
 310         }
 311 }
 312
 313 static void event_run(struct event *event)
 314 {
 315         struct udev_list_node *loop;
 316
 317         udev_list_node_foreach(loop, &worker_list) {
 318                 struct worker *worker = node_to_worker(loop);
 319                 ssize_t count;
 320
 321                 if (worker->state != WORKER_IDLE)
 322                         continue;
 323
 324                 worker->event = event;
 325                 worker->state = WORKER_RUNNING;
 326                 event->state = EVENT_RUNNING;
 327                 count = udev_monitor_send_device(monitor, worker->monitor, event->dev);
 328                 if (count < 0) {
 329                         err(event->udev, "worker [%u] did not accept message, kill it\n", worker->pid);
 330                         event->state = EVENT_QUEUED;
 331                         worker->state = WORKER_KILLED;
 332                         kill(worker->pid, SIGKILL);
 333                         continue;
 334                 }
 335                 return;
 336         }
 337
 338         if (childs >= max_childs) {
 339                 info(event->udev, "maximum number (%i) of childs reached\n", childs);
 340                 return;
 341         }
 342
 343         /* start new worker and pass initial device */
 344         worker_new(event);
 345 }
 346
 347 static void event_queue_insert(struct udev_device *dev)
 348 {
 349         struct event *event;
 350
 351         event = calloc(1, sizeof(struct event));
 352         if (event == NULL)
 353                 return;
 354
 355         event->udev = udev_device_get_udev(dev);
 356         event->dev = dev;
 357         event->seqnum = udev_device_get_seqnum(dev);
 358         event->devpath = udev_device_get_devpath(dev);
 359         event->devpath_len = strlen(event->devpath);
 360         event->devpath_old = udev_device_get_devpath_old(dev);
 361
 362         udev_queue_export_device_queued(udev_queue_export, dev);
 363         info(event->udev, "seq %llu queued, '%s' '%s'\n", udev_device_get_seqnum(dev),
 364              udev_device_get_action(dev), udev_device_get_subsystem(dev));
 365
 366         event->state = EVENT_QUEUED;
 367         udev_list_node_append(&event->node, &event_list);
 368
 369         /* run all events with a timeout set immediately */
 370         if (udev_device_get_timeout(dev) > 0) {
 371                 worker_new(event);
 372                 return;
 373         }
 374 }
 375
 376 static void worker_kill(int retain)
 377 {
 378         struct udev_list_node *loop;
 379         int max;
 380
 381         if (childs <= retain)
 382                 return;
 383
 384         max = childs - retain;
 385
 386         udev_list_node_foreach(loop, &worker_list) {
 387                 struct worker *worker = node_to_worker(loop);
 388
 389                 if (max-- <= 0)
 390                         break;
 391
 392                 if (worker->state == WORKER_KILLED)
 393                         continue;
 394
 395                 worker->state = WORKER_KILLED;
 396                 kill(worker->pid, SIGTERM);
 397         }
 398 }
 399
 400 static int mem_size_mb(void)
 401 {
 402         FILE *f;
 403         char buf[4096];
 404         long int memsize = -1;
 405
 406         f = fopen("/proc/meminfo", "r");
 407         if (f == NULL)
 408                 return -1;
 409
 410         while (fgets(buf, sizeof(buf), f) != NULL) {
 411                 long int value;
 412
 413                 if (sscanf(buf, "MemTotal: %ld kB", &value) == 1) {
 414                         memsize = value / 1024;
 415                         break;
 416                 }
 417         }
 418
 419         fclose(f);
 420         return memsize;
 421 }
 422
 423 /* lookup event for identical, parent, child device */
 424 static int devpath_busy(struct event *event)
 425 {
 426         struct udev_list_node *loop;
 427         size_t common;
 428
 429         /* check if queue contains events we depend on */
 430         udev_list_node_foreach(loop, &event_list) {
 431                 struct event *loop_event = node_to_event(loop);
 432
 433                 /* we already found a later event, earlier can not block us, no need to check again */
 434                 if (loop_event->seqnum < event->delaying_seqnum)
 435                         continue;
 436
 437                 /* event we checked earlier still exists, no need to check again */
 438                 if (loop_event->seqnum == event->delaying_seqnum)
 439                         return 2;
 440
 441                 /* found ourself, no later event can block us */
 442                 if (loop_event->seqnum >= event->seqnum)
 443                         break;
 444
 445                 /* check our old name */
 446                 if (event->devpath_old != NULL)
 447                         if (strcmp(loop_event->devpath, event->devpath_old) == 0) {
 448                                 event->delaying_seqnum = loop_event->seqnum;
 449                                 return 3;
 450                         }
 451
 452                 /* compare devpath */
 453                 common = MIN(loop_event->devpath_len, event->devpath_len);
 454
 455                 /* one devpath is contained in the other? */
 456                 if (memcmp(loop_event->devpath, event->devpath, common) != 0)
 457                         continue;
 458
 459                 /* identical device event found */
 460                 if (loop_event->devpath_len == event->devpath_len) {
 461                         event->delaying_seqnum = loop_event->seqnum;
 462                         return 4;
 463                 }
 464
 465                 /* parent device event found */
 466                 if (event->devpath[common] == '/') {
 467                         event->delaying_seqnum = loop_event->seqnum;
 468                         return 5;
 469                 }
 470
 471                 /* child device event found */
 472                 if (loop_event->devpath[common] == '/') {
 473                         event->delaying_seqnum = loop_event->seqnum;
 474                         return 6;
 475                 }
 476
 477                 /* no matching device */
 478                 continue;
 479         }
 480
 481         return 0;
 482 }
 483
 484 static void events_start(struct udev *udev)
 485 {
 486         struct udev_list_node *loop;
 487
 488         udev_list_node_foreach(loop, &event_list) {
 489                 struct event *event = node_to_event(loop);
 490
 491                 if (event->state != EVENT_QUEUED)
 492                         continue;
 493
 494                 /* do not start event if parent or child event is still running */
 495                 if (devpath_busy(event) != 0) {
 496                         dbg(udev, "delay seq %llu (%s)\n", event->seqnum, event->devpath);
 497                         continue;
 498                 }
 499
 500                 event_run(event);
 501         }
 502 }
 503
 504 static void worker_returned(void)
 505 {
 506         while (1) {
 507                 struct worker_message msg;
 508                 ssize_t size;
 509                 struct udev_list_node *loop;
 510
 511                 size = recv(pfd[FD_WORKER].fd, &msg, sizeof(struct worker_message), MSG_DONTWAIT);
 512                 if (size != sizeof(struct worker_message))
 513                         break;
 514
 515                 /* lookup worker who sent the signal */
 516                 udev_list_node_foreach(loop, &worker_list) {
 517                         struct worker *worker = node_to_worker(loop);
 518
 519                         if (worker->pid != msg.pid)
 520                                 continue;
 521
 522                         /* worker returned */
 523                         worker->event->exitcode = msg.exitcode;
 524                         event_queue_delete(worker->event);
 525                         worker->event = NULL;
 526                         worker->state = WORKER_IDLE;
 527                         break;
 528                 }
 529         }
 530 }
 531
 532 /* receive the udevd message from userspace */
 533 static void handle_ctrl_msg(struct udev_ctrl *uctrl)
 534 {
 535         struct udev *udev = udev_ctrl_get_udev(uctrl);
 536         struct udev_ctrl_msg *ctrl_msg;
 537         const char *str;
 538         int i;
 539
 540         ctrl_msg = udev_ctrl_receive_msg(uctrl);
 541         if (ctrl_msg == NULL)
 542                 return;
 543
 544         i = udev_ctrl_get_set_log_level(ctrl_msg);
 545         if (i >= 0) {
 546                 info(udev, "udevd message (SET_LOG_PRIORITY) received, log_priority=%i\n", i);
 547                 udev_set_log_priority(udev, i);
 548                 worker_kill(0);
 549         }
 550
 551         if (udev_ctrl_get_stop_exec_queue(ctrl_msg) > 0) {
 552                 info(udev, "udevd message (STOP_EXEC_QUEUE) received\n");
 553                 stop_exec_queue = 1;
 554         }
 555
 556         if (udev_ctrl_get_start_exec_queue(ctrl_msg) > 0) {
 557                 info(udev, "udevd message (START_EXEC_QUEUE) received\n");
 558                 stop_exec_queue = 0;
 559         }
 560
 561         if (udev_ctrl_get_reload_rules(ctrl_msg) > 0) {
 562                 info(udev, "udevd message (RELOAD_RULES) received\n");
 563                 reload_config = 1;
 564         }
 565
 566         str = udev_ctrl_get_set_env(ctrl_msg);
 567         if (str != NULL) {
 568                 char *key;
 569
 570                 key = strdup(str);
 571                 if (key != NULL) {
 572                         char *val;
 573
 574                         val = strchr(key, '=');
 575                         if (val != NULL) {
 576                                 val[0] = '\0';
 577                                 val = &val[1];
 578                                 if (val[0] == '\0') {
 579                                         info(udev, "udevd message (ENV) received, unset '%s'\n", key);
 580                                         udev_add_property(udev, key, NULL);
 581                                 } else {
 582                                         info(udev, "udevd message (ENV) received, set '%s=%s'\n", key, val);
 583                                         udev_add_property(udev, key, val);
 584                                 }
 585                         } else {
 586                                 err(udev, "wrong key format '%s'\n", key);
 587                         }
 588                         free(key);
 589                 }
 590                 worker_kill(0);
 591         }
 592
 593         i = udev_ctrl_get_set_max_childs(ctrl_msg);
 594         if (i >= 0) {
 595                 info(udev, "udevd message (SET_MAX_CHILDS) received, max_childs=%i\n", i);
 596                 max_childs = i;
 597         }
 598
 599         settle_pid = udev_ctrl_get_settle(ctrl_msg);
 600         if (settle_pid > 0) {
 601                 info(udev, "udevd message (SETTLE) received\n");
 602                 kill(settle_pid, SIGUSR1);
 603                 settle_pid = 0;
 604         }
 605         udev_ctrl_msg_unref(ctrl_msg);
 606 }
 607
 608 /* read inotify messages */
 609 static int handle_inotify(struct udev *udev)
 610 {
 611         ssize_t nbytes, pos;
 612         char *buf;
 613         struct inotify_event *ev;
 614
 615         if ((ioctl(pfd[FD_INOTIFY].fd, FIONREAD, &nbytes) < 0) || (nbytes <= 0))
 616                 return 0;
 617
 618         buf = malloc(nbytes);
 619         if (buf == NULL) {
 620                 err(udev, "error getting buffer for inotify, disable watching\n");
 621                 return -1;
 622         }
 623
 624         nbytes = read(pfd[FD_INOTIFY].fd, buf, nbytes);
 625
 626         for (pos = 0; pos < nbytes; pos += sizeof(struct inotify_event) + ev->len) {
 627                 struct udev_device *dev;
 628
 629                 ev = (struct inotify_event *)(buf + pos);
 630                 if (ev->len) {
 631                         dbg(udev, "inotify event: %x for %s\n", ev->mask, ev->name);
 632                         reload_config = 1;
 633                         continue;
 634                 }
 635
 636                 dev = udev_watch_lookup(udev, ev->wd);
 637                 if (dev != NULL) {
 638                         dbg(udev, "inotify event: %x for %s\n", ev->mask, udev_device_get_devnode(dev));
 639                         if (ev->mask & IN_CLOSE_WRITE) {
 640                                 char filename[UTIL_PATH_SIZE];
 641                                 int fd;
 642
 643                                 info(udev, "device %s closed, synthesising 'change'\n", udev_device_get_devnode(dev));
 644                                 util_strscpyl(filename, sizeof(filename), udev_device_get_syspath(dev), "/uevent", NULL);
 645                                 fd = open(filename, O_WRONLY);
 646                                 if (fd < 0 || write(fd, "change", 6) < 0)
 647                                         info(udev, "error writing uevent: %m\n");
 648                                 close(fd);
 649                         }
 650                         if (ev->mask & IN_IGNORED)
 651                                 udev_watch_end(udev, dev);
 652
 653                         udev_device_unref(dev);
 654                 }
 655
 656         }
 657
 658         free(buf);
 659         return 0;
 660 }
 661
 662 static void handle_signal(int signo)
 663 {
 664         switch (signo) {
 665         case SIGINT:
 666         case SIGTERM:
 667                 udev_exit = 1;
 668                 break;
 669         case SIGCHLD:
 670                 while (1) {
 671                         pid_t pid;
 672                         struct udev_list_node *loop, *tmp;
 673
 674                         pid = waitpid(-1, NULL, WNOHANG);
 675                         if (pid <= 0)
 676                                 break;
 677
 678                         udev_list_node_foreach_safe(loop, tmp, &worker_list) {
 679                                 struct worker *worker = node_to_worker(loop);
 680
 681                                 if (worker->pid != pid)
 682                                         continue;
 683
 684                                 /* fail event, if worker died unexpectedly */
 685                                 if (worker->event != NULL) {
 686                                         worker->event->exitcode = 127;
 687                                         event_queue_delete(worker->event);
 688                                 }
 689
 690                                 udev_list_node_remove(&worker->node);
 691                                 worker_unref(worker);
 692                                 childs--;
 693                                 break;
 694                         }
 695                 }
 696                 break;
 697         case SIGHUP:
 698                 reload_config = 1;
 699                 break;
 700         }
 701 }
 702
 703 static void startup_log(struct udev *udev)
 704 {
 705         FILE *f;
 706         char path[UTIL_PATH_SIZE];
 707         struct stat statbuf;
 708
 709         f = fopen("/dev/kmsg", "w");
 710         if (f != NULL)
 711                 fprintf(f, "<6>udev: starting version " VERSION "\n");
 712
 713         util_strscpyl(path, sizeof(path), udev_get_sys_path(udev), "/class/mem/null", NULL);
 714         if (lstat(path, &statbuf) == 0 && S_ISDIR(statbuf.st_mode)) {
 715                 const char *depr_str =
 716                         "udev: missing sysfs features; please update the kernel "
 717                         "or disable the kernel's CONFIG_SYSFS_DEPRECATED option; "
 718                         "udev may fail to work correctly";
 719
 720                 if (f != NULL)
 721                         fprintf(f, "<3>%s\n", depr_str);
 722                 err(udev, "%s\n", depr_str);
 723                 sleep(3);
 724         }
 725
 726         if (f != NULL)
 727                 fclose(f);
 728 }
 729
 730 int main(int argc, char *argv[])
 731 {
 732         struct udev *udev;
 733         int fd;
 734         sigset_t mask;
 735         const char *value;
 736         int daemonize = 0;
 737         int resolve_names = 1;
 738         static const struct option options[] = {
 739                 { "daemon", no_argument, NULL, 'd' },
 740                 { "debug-trace", no_argument, NULL, 't' },
 741                 { "debug", no_argument, NULL, 'D' },
 742                 { "help", no_argument, NULL, 'h' },
 743                 { "version", no_argument, NULL, 'V' },
 744                 { "resolve-names", required_argument, NULL, 'N' },
 745                 {}
 746         };
 747         int rc = 1;
 748
 749         udev = udev_new();
 750         if (udev == NULL)
 751                 goto exit;
 752
 753         logging_init("udevd");
 754         udev_set_log_fn(udev, log_fn);
 755         info(udev, "version %s\n", VERSION);
 756         udev_selinux_init(udev);
 757
 758         while (1) {
 759                 int option;
 760
 761                 option = getopt_long(argc, argv, "dDthV", options, NULL);
 762                 if (option == -1)
 763                         break;
 764
 765                 switch (option) {
 766                 case 'd':
 767                         daemonize = 1;
 768                         break;
 769                 case 't':
 770                         debug_trace = 1;
 771                         break;
 772                 case 'D':
 773                         debug = 1;
 774                         if (udev_get_log_priority(udev) < LOG_INFO)
 775                                 udev_set_log_priority(udev, LOG_INFO);
 776                         break;
 777                 case 'N':
 778                         if (strcmp (optarg, "early") == 0) {
 779                                 resolve_names = 1;
 780                         } else if (strcmp (optarg, "late") == 0) {
 781                                 resolve_names = 0;
 782                         } else if (strcmp (optarg, "never") == 0) {
 783                                 resolve_names = -1;
 784                         } else {
 785                                 fprintf(stderr, "resolve-names must be early, late or never\n");
 786                                 err(udev, "resolve-names must be early, late or never\n");
 787                                 goto exit;
 788                         }
 789                         break;
 790                 case 'h':
 791                         printf("Usage: udevd [--help] [--daemon] [--debug-trace] [--debug] "
 792                                "[--resolve-names=early|late|never] [--version]\n");
 793                         goto exit;
 794                 case 'V':
 795                         printf("%s\n", VERSION);
 796                         goto exit;
 797                 default:
 798                         goto exit;
 799                 }
 800         }
 801
 802         if (getuid() != 0) {
 803                 fprintf(stderr, "root privileges required\n");
 804                 err(udev, "root privileges required\n");
 805                 goto exit;
 806         }
 807
 808         /* make sure std{in,out,err} fd's are in a sane state */
 809         fd = open("/dev/null", O_RDWR);
 810         if (fd < 0) {
 811                 fprintf(stderr, "cannot open /dev/null\n");
 812                 err(udev, "cannot open /dev/null\n");
 813         }
 814         if (write(STDOUT_FILENO, 0, 0) < 0)
 815                 dup2(fd, STDOUT_FILENO);
 816         if (write(STDERR_FILENO, 0, 0) < 0)
 817                 dup2(fd, STDERR_FILENO);
 818
 819         /* init control socket, bind() ensures, that only one udevd instance is running */
 820         udev_ctrl = udev_ctrl_new_from_socket(udev, UDEV_CTRL_SOCK_PATH);
 821         if (udev_ctrl == NULL) {
 822                 fprintf(stderr, "error initializing control socket");
 823                 err(udev, "error initializing udevd socket");
 824                 rc = 1;
 825                 goto exit;
 826         }
 827         if (udev_ctrl_enable_receiving(udev_ctrl) < 0) {
 828                 fprintf(stderr, "error binding control socket, seems udevd is already running\n");
 829                 err(udev, "error binding control socket, seems udevd is already running\n");
 830                 rc = 1;
 831                 goto exit;
 832         }
 833         pfd[FD_CONTROL].fd = udev_ctrl_get_fd(udev_ctrl);
 834
 835         monitor = udev_monitor_new_from_netlink(udev, "kernel");
 836         if (monitor == NULL || udev_monitor_enable_receiving(monitor) < 0) {
 837                 fprintf(stderr, "error initializing netlink socket\n");
 838                 err(udev, "error initializing netlink socket\n");
 839                 rc = 3;
 840                 goto exit;
 841         }
 842         udev_monitor_set_receive_buffer_size(monitor, 128*1024*1024);
 843         pfd[FD_NETLINK].fd = udev_monitor_get_fd(monitor);
 844
 845         pfd[FD_INOTIFY].fd = udev_watch_init(udev);
 846         if (pfd[FD_INOTIFY].fd < 0) {
 847                 fprintf(stderr, "error initializing inotify\n");
 848                 err(udev, "error initializing inotify\n");
 849                 rc = 4;
 850                 goto exit;
 851         }
 852
 853         if (udev_get_rules_path(udev) != NULL) {
 854                 inotify_add_watch(pfd[FD_INOTIFY].fd, udev_get_rules_path(udev),
 855                                   IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
 856         } else {
 857                 char filename[UTIL_PATH_SIZE];
 858
 859                 inotify_add_watch(pfd[FD_INOTIFY].fd, UDEV_PREFIX "/lib/udev/rules.d",
 860                                   IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
 861                 inotify_add_watch(pfd[FD_INOTIFY].fd, SYSCONFDIR "/udev/rules.d",
 862                                   IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
 863
 864                 /* watch dynamic rules directory */
 865                 util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev), "/.udev/rules.d", NULL);
 866                 inotify_add_watch(pfd[FD_INOTIFY].fd, filename,
 867                                   IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
 868         }
 869         udev_watch_restore(udev);
 870
 871         /* block and listen to all signals on signalfd */
 872         sigfillset(&mask);
 873         sigprocmask(SIG_SETMASK, &mask, NULL);
 874         pfd[FD_SIGNAL].fd = signalfd(-1, &mask, 0);
 875         if (pfd[FD_SIGNAL].fd < 0) {
 876                 fprintf(stderr, "error getting signalfd\n");
 877                 err(udev, "error getting signalfd\n");
 878                 rc = 5;
 879                 goto exit;
 880         }
 881
 882         /* unnamed socket from workers to the main daemon */
 883         if (socketpair(AF_LOCAL, SOCK_DGRAM, 0, worker_watch) < 0) {
 884                 fprintf(stderr, "error getting socketpair\n");
 885                 err(udev, "error getting socketpair\n");
 886                 rc = 6;
 887                 goto exit;
 888         }
 889         pfd[FD_WORKER].fd = worker_watch[READ_END];
 890         util_set_fd_cloexec(worker_watch[WRITE_END]);
 891
 892         rules = udev_rules_new(udev, resolve_names);
 893         if (rules == NULL) {
 894                 err(udev, "error reading rules\n");
 895                 goto exit;
 896         }
 897
 898         udev_queue_export = udev_queue_export_new(udev);
 899         if (udev_queue_export == NULL) {
 900                 err(udev, "error creating queue file\n");
 901                 goto exit;
 902         }
 903
 904         if (daemonize) {
 905                 pid_t pid;
 906
 907                 pid = fork();
 908                 switch (pid) {
 909                 case 0:
 910                         break;
 911                 case -1:
 912                         err(udev, "fork of daemon failed: %m\n");
 913                         rc = 4;
 914                         goto exit;
 915                 default:
 916                         rc = 0;
 917                         goto exit;
 918                 }
 919         }
 920
 921         startup_log(udev);
 922
 923         /* redirect std{out,err} */
 924         if (!debug && !debug_trace) {
 925                 dup2(fd, STDIN_FILENO);
 926                 dup2(fd, STDOUT_FILENO);
 927                 dup2(fd, STDERR_FILENO);
 928         }
 929         if (fd > STDERR_FILENO)
 930                 close(fd);
 931
 932         /* set scheduling priority for the daemon */
 933         setpriority(PRIO_PROCESS, 0, UDEVD_PRIORITY);
 934
 935         chdir("/");
 936         umask(022);
 937         setsid();
 938
 939         /* OOM_DISABLE == -17 */
 940         fd = open("/proc/self/oom_adj", O_RDWR);
 941         if (fd < 0)
 942                 err(udev, "error disabling OOM: %m\n");
 943         else {
 944                 write(fd, "-17", 3);
 945                 close(fd);
 946         }
 947
 948         /* in trace mode run one event after the other */
 949         if (debug_trace) {
 950                 max_childs = 1;
 951         } else {
 952                 int memsize = mem_size_mb();
 953
 954                 if (memsize > 0)
 955                         max_childs = 128 + (memsize / 8);
 956                 else
 957                         max_childs = 128;
 958         }
 959
 960         /* possibly overwrite maximum limit of executed events */
 961         value = getenv("UDEVD_MAX_CHILDS");
 962         if (value)
 963                 max_childs = strtoul(value, NULL, 10);
 964         info(udev, "initialize max_childs to %u\n", max_childs);
 965
 966         udev_list_init(&event_list);
 967         udev_list_init(&worker_list);
 968
 969         while (!udev_exit) {
 970                 int fdcount;
 971                 int timeout;
 972
 973                 /* set timeout to kill idle workers */
 974                 if (udev_list_is_empty(&event_list) && childs > 2)
 975                         timeout = 3 * 1000;
 976                 else
 977                         timeout = -1;
 978                 /* wait for events */
 979                 fdcount = poll(pfd, ARRAY_SIZE(pfd), timeout);
 980                 if (fdcount < 0)
 981                         continue;
 982
 983                 /* timeout - kill idle workers */
 984                 if (fdcount == 0)
 985                         worker_kill(2);
 986
 987                 /* event has finished */
 988                 if (pfd[FD_WORKER].revents & POLLIN)
 989                         worker_returned();
 990
 991                 /* get kernel uevent */
 992                 if (pfd[FD_NETLINK].revents & POLLIN) {
 993                         struct udev_device *dev;
 994
 995                         dev = udev_monitor_receive_device(monitor);
 996                         if (dev != NULL)
 997                                 event_queue_insert(dev);
 998                         else
 999                                 udev_device_unref(dev);
1000                 }
1001
1002                 /* start new events */
1003                 if (!udev_list_is_empty(&event_list) && !stop_exec_queue)
1004                         events_start(udev);
1005
1006                 /* get signal */
1007                 if (pfd[FD_SIGNAL].revents & POLLIN) {
1008                         struct signalfd_siginfo fdsi;
1009                         ssize_t size;
1010
1011                         size = read(pfd[FD_SIGNAL].fd, &fdsi, sizeof(struct signalfd_siginfo));
1012                         if (size == sizeof(struct signalfd_siginfo))
1013                                 handle_signal(fdsi.ssi_signo);
1014                 }
1015
1016                 /* device node and rules directory inotify watch */
1017                 if (pfd[FD_INOTIFY].revents & POLLIN)
1018                         handle_inotify(udev);
1019
1020                 /*
1021                  * get control message
1022                  *
1023                  * This needs to be after the inotify handling, to make sure,
1024                  * that the settle signal is send back after the possibly generated
1025                  * "change" events by the inotify device node watch.
1026                  */
1027                 if (pfd[FD_CONTROL].revents & POLLIN)
1028                         handle_ctrl_msg(udev_ctrl);
1029
1030                 /* rules changed, set by inotify or a HUP signal */
1031                 if (reload_config) {
1032                         struct udev_rules *rules_new;
1033
1034                         worker_kill(0);
1035                         rules_new = udev_rules_new(udev, resolve_names);
1036                         if (rules_new != NULL) {
1037                                 udev_rules_unref(rules);
1038                                 rules = rules_new;
1039                         }
1040                         reload_config = 0;
1041                 }
1042         }
1043
1044         udev_queue_export_cleanup(udev_queue_export);
1045         rc = 0;
1046 exit:
1047         udev_queue_export_unref(udev_queue_export);
1048         udev_rules_unref(rules);
1049         udev_ctrl_unref(udev_ctrl);
1050         if (pfd[FD_SIGNAL].fd >= 0)
1051                 close(pfd[FD_SIGNAL].fd);
1052         if (worker_watch[READ_END] >= 0)
1053                 close(worker_watch[READ_END]);
1054         if (worker_watch[WRITE_END] >= 0)
1055                 close(worker_watch[WRITE_END]);
1056         udev_monitor_unref(monitor);
1057         udev_selinux_exit(udev);
1058         udev_unref(udev);
1059         logging_close();
1060         return rc;
1061 }