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 <stdbool.h>
  28 #include <string.h>
  29 #include <ctype.h>
  30 #include <fcntl.h>
  31 #include <time.h>
  32 #include <getopt.h>
  33 #include <dirent.h>
  34 #include <sys/time.h>
  35 #include <sys/prctl.h>
  36 #include <sys/socket.h>
  37 #include <sys/un.h>
  38 #include <sys/signalfd.h>
  39 #include <sys/select.h>
  40 #include <sys/poll.h>
  41 #include <sys/wait.h>
  42 #include <sys/stat.h>
  43 #include <sys/ioctl.h>
  44 #include <sys/inotify.h>
  45 #include <sys/utsname.h>
  46
  47 #include "udev.h"
  48
  49 #define UDEVD_PRIORITY                  -4
  50 #define UDEV_PRIORITY                   -2
  51
  52 static bool debug;
  53
  54 static void log_fn(struct udev *udev, int priority,
  55                    const char *file, int line, const char *fn,
  56                    const char *format, va_list args)
  57 {
  58         if (debug) {
  59                 char buf[1024];
  60                 struct timeval tv;
  61                 struct timezone tz;
  62
  63                 vsnprintf(buf, sizeof(buf), format, args);
  64                 gettimeofday(&tv, &tz);
  65                 fprintf(stderr, "%llu.%06u [%u] %s: %s",
  66                         (unsigned long long) tv.tv_sec, (unsigned int) tv.tv_usec,
  67                         (int) getpid(), fn, buf);
  68         } else {
  69                 vsyslog(priority, format, args);
  70         }
  71 }
  72
  73 static struct udev_rules *rules;
  74 static struct udev_queue_export *udev_queue_export;
  75 static struct udev_ctrl *udev_ctrl;
  76 static struct udev_monitor *monitor;
  77 static int worker_watch[2];
  78 static pid_t settle_pid;
  79 static bool stop_exec_queue;
  80 static bool reload_config;
  81 static int children;
  82 static int children_max;
  83 static int exec_delay;
  84 static sigset_t orig_sigmask;
  85 static struct udev_list_node event_list;
  86 static struct udev_list_node worker_list;
  87 static bool udev_exit;
  88 static volatile sig_atomic_t worker_exit;
  89
  90 enum poll_fd {
  91         FD_CONTROL,
  92         FD_NETLINK,
  93         FD_INOTIFY,
  94         FD_SIGNAL,
  95         FD_WORKER,
  96 };
  97
  98 static struct pollfd pfd[] = {
  99         [FD_NETLINK] = { .events = POLLIN },
 100         [FD_WORKER] =  { .events = POLLIN },
 101         [FD_SIGNAL] =  { .events = POLLIN },
 102         [FD_INOTIFY] = { .events = POLLIN },
 103         [FD_CONTROL] = { .events = POLLIN },
 104 };
 105
 106 enum event_state {
 107         EVENT_UNDEF,
 108         EVENT_QUEUED,
 109         EVENT_RUNNING,
 110 };
 111
 112 struct event {
 113         struct udev_list_node node;
 114         struct udev *udev;
 115         struct udev_device *dev;
 116         enum event_state state;
 117         int exitcode;
 118         unsigned long long int delaying_seqnum;
 119         unsigned long long int seqnum;
 120         const char *devpath;
 121         size_t devpath_len;
 122         const char *devpath_old;
 123         dev_t devnum;
 124         bool is_block;
 125 };
 126
 127 static struct event *node_to_event(struct udev_list_node *node)
 128 {
 129         char *event;
 130
 131         event = (char *)node;
 132         event -= offsetof(struct event, node);
 133         return (struct event *)event;
 134 }
 135
 136 enum worker_state {
 137         WORKER_UNDEF,
 138         WORKER_RUNNING,
 139         WORKER_IDLE,
 140         WORKER_KILLED,
 141 };
 142
 143 struct worker {
 144         struct udev_list_node node;
 145         struct udev *udev;
 146         int refcount;
 147         pid_t pid;
 148         struct udev_monitor *monitor;
 149         enum worker_state state;
 150         struct event *event;
 151 };
 152
 153 /* passed from worker to main process */
 154 struct worker_message {
 155         pid_t pid;
 156         int exitcode;
 157 };
 158
 159 static struct worker *node_to_worker(struct udev_list_node *node)
 160 {
 161         char *worker;
 162
 163         worker = (char *)node;
 164         worker -= offsetof(struct worker, node);
 165         return (struct worker *)worker;
 166 }
 167
 168 static void event_queue_delete(struct event *event)
 169 {
 170         udev_list_node_remove(&event->node);
 171
 172         /* mark as failed, if "add" event returns non-zero */
 173         if (event->exitcode != 0 && strcmp(udev_device_get_action(event->dev), "remove") != 0)
 174                 udev_queue_export_device_failed(udev_queue_export, event->dev);
 175         else
 176                 udev_queue_export_device_finished(udev_queue_export, event->dev);
 177
 178         info(event->udev, "seq %llu done with %i\n", udev_device_get_seqnum(event->dev), event->exitcode);
 179         udev_device_unref(event->dev);
 180         free(event);
 181 }
 182
 183 static void event_sig_handler(int signum)
 184 {
 185         switch (signum) {
 186         case SIGALRM:
 187                 _exit(1);
 188                 break;
 189         case SIGTERM:
 190                 worker_exit = true;
 191                 break;
 192         }
 193 }
 194
 195 static struct worker *worker_ref(struct worker *worker)
 196 {
 197         worker->refcount++;
 198         return worker;
 199 }
 200
 201 static void worker_unref(struct worker *worker)
 202 {
 203         worker->refcount--;
 204         if (worker->refcount > 0)
 205                 return;
 206
 207         udev_list_node_remove(&worker->node);
 208         udev_monitor_unref(worker->monitor);
 209         children--;
 210         info(worker->udev, "worker [%u] cleaned up\n", worker->pid);
 211         free(worker);
 212 }
 213
 214 static void worker_new(struct event *event)
 215 {
 216         struct worker *worker;
 217         struct udev_monitor *worker_monitor;
 218         pid_t pid;
 219         struct sigaction act;
 220
 221         /* listen for new events */
 222         worker_monitor = udev_monitor_new_from_netlink(event->udev, NULL);
 223         if (worker_monitor == NULL)
 224                 return;
 225         /* allow the main daemon netlink address to send devices to the worker */
 226         udev_monitor_allow_unicast_sender(worker_monitor, monitor);
 227         udev_monitor_enable_receiving(worker_monitor);
 228
 229         worker = calloc(1, sizeof(struct worker));
 230         if (worker == NULL) {
 231                 udev_monitor_unref(worker_monitor);
 232                 return;
 233         }
 234         /* worker + event reference */
 235         worker->refcount = 2;
 236         worker->udev = event->udev;
 237
 238         pid = fork();
 239         switch (pid) {
 240         case 0: {
 241                 sigset_t sigmask;
 242                 struct udev_device *dev;
 243                 struct pollfd pmon = {
 244                         .fd = udev_monitor_get_fd(worker_monitor),
 245                         .events = POLLIN,
 246                 };
 247
 248                 udev_queue_export_unref(udev_queue_export);
 249                 udev_monitor_unref(monitor);
 250                 udev_ctrl_unref(udev_ctrl);
 251                 close(pfd[FD_SIGNAL].fd);
 252                 close(worker_watch[READ_END]);
 253                 udev_log_close();
 254                 udev_log_init("udevd-work");
 255                 setpriority(PRIO_PROCESS, 0, UDEV_PRIORITY);
 256
 257                 /* set signal handlers */
 258                 memset(&act, 0x00, sizeof(act));
 259                 act.sa_handler = event_sig_handler;
 260                 sigemptyset (&act.sa_mask);
 261                 act.sa_flags = 0;
 262                 sigaction(SIGTERM, &act, NULL);
 263                 sigaction(SIGALRM, &act, NULL);
 264
 265                 /* unblock SIGALRM */
 266                 sigfillset(&sigmask);
 267                 sigdelset(&sigmask, SIGALRM);
 268                 sigprocmask(SIG_SETMASK, &sigmask, NULL);
 269                 /* SIGTERM is unblocked in ppoll() */
 270                 sigdelset(&sigmask, SIGTERM);
 271
 272                 /* request TERM signal if parent exits */
 273                 prctl(PR_SET_PDEATHSIG, SIGTERM);
 274
 275                 /* initial device */
 276                 dev = event->dev;
 277
 278                 do {
 279                         struct udev_event *udev_event;
 280                         struct worker_message msg = {};
 281                         int err;
 282                         int failed = 0;
 283
 284                         info(event->udev, "seq %llu running\n", udev_device_get_seqnum(dev));
 285                         udev_event = udev_event_new(dev);
 286                         if (udev_event == NULL)
 287                                 _exit(3);
 288
 289                         /* set timeout to prevent hanging processes */
 290                         alarm(UDEV_EVENT_TIMEOUT);
 291
 292                         if (exec_delay > 0)
 293                                 udev_event->exec_delay = exec_delay;
 294
 295                         /* apply rules, create node, symlinks */
 296                         err = udev_event_execute_rules(udev_event, rules);
 297
 298                         /* rules may change/disable the timeout */
 299                         if (udev_device_get_event_timeout(dev) >= 0)
 300                                 alarm(udev_device_get_event_timeout(dev));
 301
 302                         if (err == 0)
 303                                 failed = udev_event_execute_run(udev_event, &orig_sigmask);
 304
 305                         alarm(0);
 306
 307                         /* apply/restore inotify watch */
 308                         if (err == 0 && udev_event->inotify_watch) {
 309                                 udev_watch_begin(udev_event->udev, dev);
 310                                 udev_device_update_db(dev);
 311                         }
 312
 313                         /* send processed event back to libudev listeners */
 314                         udev_monitor_send_device(worker_monitor, NULL, dev);
 315
 316                         /* send udevd the result of the event execution */
 317                         if (err != 0)
 318                                 msg.exitcode = err;
 319                         else if (failed != 0)
 320                                 msg.exitcode = failed;
 321                         msg.pid = getpid();
 322                         send(worker_watch[WRITE_END], &msg, sizeof(struct worker_message), 0);
 323
 324                         info(event->udev, "seq %llu processed with %i\n", udev_device_get_seqnum(dev), err);
 325                         udev_event_unref(udev_event);
 326                         udev_device_unref(dev);
 327                         dev = NULL;
 328
 329                         /* wait for more device messages or signal from udevd */
 330                         while (!worker_exit) {
 331                                 int fdcount;
 332
 333                                 fdcount = ppoll(&pmon, 1, NULL, &sigmask);
 334                                 if (fdcount < 0)
 335                                         continue;
 336
 337                                 if (pmon.revents & POLLIN) {
 338                                         dev = udev_monitor_receive_device(worker_monitor);
 339                                         if (dev != NULL)
 340                                                 break;
 341                                 }
 342                         }
 343                 } while (dev != NULL);
 344
 345                 udev_monitor_unref(worker_monitor);
 346                 udev_log_close();
 347                 exit(0);
 348         }
 349         case -1:
 350                 udev_monitor_unref(worker_monitor);
 351                 event->state = EVENT_QUEUED;
 352                 free(worker);
 353                 err(event->udev, "fork of child failed: %m\n");
 354                 break;
 355         default:
 356                 /* close monitor, but keep address around */
 357                 udev_monitor_disconnect(worker_monitor);
 358                 worker->monitor = worker_monitor;
 359                 worker->pid = pid;
 360                 worker->state = WORKER_RUNNING;
 361                 worker->event = event;
 362                 event->state = EVENT_RUNNING;
 363                 udev_list_node_append(&worker->node, &worker_list);
 364                 children++;
 365                 info(event->udev, "seq %llu forked new worker [%u]\n", udev_device_get_seqnum(event->dev), pid);
 366                 break;
 367         }
 368 }
 369
 370 static void event_run(struct event *event, bool force)
 371 {
 372         struct udev_list_node *loop;
 373
 374         udev_list_node_foreach(loop, &worker_list) {
 375                 struct worker *worker = node_to_worker(loop);
 376                 ssize_t count;
 377
 378                 if (worker->state != WORKER_IDLE)
 379                         continue;
 380
 381                 count = udev_monitor_send_device(monitor, worker->monitor, event->dev);
 382                 if (count < 0) {
 383                         err(event->udev, "worker [%u] did not accept message %zi (%m), kill it\n", worker->pid, count);
 384                         kill(worker->pid, SIGKILL);
 385                         worker->state = WORKER_KILLED;
 386                         continue;
 387                 }
 388                 worker_ref(worker);
 389                 worker->event = event;
 390                 worker->state = WORKER_RUNNING;
 391                 event->state = EVENT_RUNNING;
 392                 return;
 393         }
 394
 395         if (!force && children >= children_max) {
 396                 if (children_max > 1)
 397                         info(event->udev, "maximum number (%i) of children reached\n", children);
 398                 return;
 399         }
 400
 401         /* start new worker and pass initial device */
 402         worker_new(event);
 403 }
 404
 405 static int event_queue_insert(struct udev_device *dev)
 406 {
 407         struct event *event;
 408
 409         event = calloc(1, sizeof(struct event));
 410         if (event == NULL)
 411                 return -1;
 412
 413         event->udev = udev_device_get_udev(dev);
 414         event->dev = dev;
 415         event->seqnum = udev_device_get_seqnum(dev);
 416         event->devpath = udev_device_get_devpath(dev);
 417         event->devpath_len = strlen(event->devpath);
 418         event->devpath_old = udev_device_get_devpath_old(dev);
 419         event->devnum = udev_device_get_devnum(dev);
 420         event->is_block = (strcmp("block", udev_device_get_subsystem(dev)) == 0);
 421
 422         udev_queue_export_device_queued(udev_queue_export, dev);
 423         info(event->udev, "seq %llu queued, '%s' '%s'\n", udev_device_get_seqnum(dev),
 424              udev_device_get_action(dev), udev_device_get_subsystem(dev));
 425
 426         event->state = EVENT_QUEUED;
 427         udev_list_node_append(&event->node, &event_list);
 428
 429         /* run all events with a timeout set immediately */
 430         if (udev_device_get_timeout(dev) > 0) {
 431                 event_run(event, true);
 432                 return 0;
 433         }
 434
 435         return 0;
 436 }
 437
 438 static void worker_kill(struct udev *udev, int retain)
 439 {
 440         struct udev_list_node *loop;
 441         int max;
 442
 443         if (children <= retain)
 444                 return;
 445
 446         max = children - retain;
 447
 448         udev_list_node_foreach(loop, &worker_list) {
 449                 struct worker *worker = node_to_worker(loop);
 450
 451                 if (max-- <= 0)
 452                         break;
 453
 454                 if (worker->state == WORKER_KILLED)
 455                         continue;
 456
 457                 worker->state = WORKER_KILLED;
 458                 kill(worker->pid, SIGTERM);
 459         }
 460 }
 461
 462 /* lookup event for identical, parent, child device */
 463 static bool is_devpath_busy(struct event *event)
 464 {
 465         struct udev_list_node *loop;
 466         size_t common;
 467
 468         /* check if queue contains events we depend on */
 469         udev_list_node_foreach(loop, &event_list) {
 470                 struct event *loop_event = node_to_event(loop);
 471
 472                 /* we already found a later event, earlier can not block us, no need to check again */
 473                 if (loop_event->seqnum < event->delaying_seqnum)
 474                         continue;
 475
 476                 /* event we checked earlier still exists, no need to check again */
 477                 if (loop_event->seqnum == event->delaying_seqnum)
 478                         return true;
 479
 480                 /* found ourself, no later event can block us */
 481                 if (loop_event->seqnum >= event->seqnum)
 482                         break;
 483
 484                 /* check major/minor */
 485                 if (major(event->devnum) != 0 && event->devnum == loop_event->devnum && event->is_block == loop_event->is_block)
 486                         return true;
 487
 488                 /* check our old name */
 489                 if (event->devpath_old != NULL && strcmp(loop_event->devpath, event->devpath_old) == 0) {
 490                         event->delaying_seqnum = loop_event->seqnum;
 491                         return true;
 492                 }
 493
 494                 /* compare devpath */
 495                 common = MIN(loop_event->devpath_len, event->devpath_len);
 496
 497                 /* one devpath is contained in the other? */
 498                 if (memcmp(loop_event->devpath, event->devpath, common) != 0)
 499                         continue;
 500
 501                 /* identical device event found */
 502                 if (loop_event->devpath_len == event->devpath_len) {
 503                         event->delaying_seqnum = loop_event->seqnum;
 504                         return true;
 505                 }
 506
 507                 /* parent device event found */
 508                 if (event->devpath[common] == '/') {
 509                         event->delaying_seqnum = loop_event->seqnum;
 510                         return true;
 511                 }
 512
 513                 /* child device event found */
 514                 if (loop_event->devpath[common] == '/') {
 515                         event->delaying_seqnum = loop_event->seqnum;
 516                         return true;
 517                 }
 518
 519                 /* no matching device */
 520                 continue;
 521         }
 522
 523         return false;
 524 }
 525
 526 static void events_start(struct udev *udev)
 527 {
 528         struct udev_list_node *loop;
 529
 530         udev_list_node_foreach(loop, &event_list) {
 531                 struct event *event = node_to_event(loop);
 532
 533                 if (event->state != EVENT_QUEUED)
 534                         continue;
 535
 536                 /* do not start event if parent or child event is still running */
 537                 if (is_devpath_busy(event)) {
 538                         dbg(udev, "delay seq %llu (%s)\n", event->seqnum, event->devpath);
 539                         continue;
 540                 }
 541
 542                 event_run(event, false);
 543         }
 544 }
 545
 546 static void worker_returned(void)
 547 {
 548         for (;;) {
 549                 struct worker_message msg;
 550                 ssize_t size;
 551                 struct udev_list_node *loop;
 552
 553                 size = recv(pfd[FD_WORKER].fd, &msg, sizeof(struct worker_message), MSG_DONTWAIT);
 554                 if (size != sizeof(struct worker_message))
 555                         break;
 556
 557                 /* lookup worker who sent the signal */
 558                 udev_list_node_foreach(loop, &worker_list) {
 559                         struct worker *worker = node_to_worker(loop);
 560
 561                         if (worker->pid != msg.pid)
 562                                 continue;
 563
 564                         /* worker returned */
 565                         worker->event->exitcode = msg.exitcode;
 566                         event_queue_delete(worker->event);
 567                         worker->event = NULL;
 568                         if (worker->state != WORKER_KILLED)
 569                                 worker->state = WORKER_IDLE;
 570                         worker_unref(worker);
 571                         break;
 572                 }
 573         }
 574 }
 575
 576 /* receive the udevd message from userspace */
 577 static void handle_ctrl_msg(struct udev_ctrl *uctrl)
 578 {
 579         struct udev *udev = udev_ctrl_get_udev(uctrl);
 580         struct udev_ctrl_msg *ctrl_msg;
 581         const char *str;
 582         int i;
 583
 584         ctrl_msg = udev_ctrl_receive_msg(uctrl);
 585         if (ctrl_msg == NULL)
 586                 return;
 587
 588         i = udev_ctrl_get_set_log_level(ctrl_msg);
 589         if (i >= 0) {
 590                 info(udev, "udevd message (SET_LOG_PRIORITY) received, log_priority=%i\n", i);
 591                 udev_set_log_priority(udev, i);
 592                 worker_kill(udev, 0);
 593         }
 594
 595         if (udev_ctrl_get_stop_exec_queue(ctrl_msg) > 0) {
 596                 info(udev, "udevd message (STOP_EXEC_QUEUE) received\n");
 597                 stop_exec_queue = true;
 598         }
 599
 600         if (udev_ctrl_get_start_exec_queue(ctrl_msg) > 0) {
 601                 info(udev, "udevd message (START_EXEC_QUEUE) received\n");
 602                 stop_exec_queue = false;
 603         }
 604
 605         if (udev_ctrl_get_reload_rules(ctrl_msg) > 0) {
 606                 info(udev, "udevd message (RELOAD_RULES) received\n");
 607                 reload_config = true;
 608         }
 609
 610         str = udev_ctrl_get_set_env(ctrl_msg);
 611         if (str != NULL) {
 612                 char *key;
 613
 614                 key = strdup(str);
 615                 if (key != NULL) {
 616                         char *val;
 617
 618                         val = strchr(key, '=');
 619                         if (val != NULL) {
 620                                 val[0] = '\0';
 621                                 val = &val[1];
 622                                 if (val[0] == '\0') {
 623                                         info(udev, "udevd message (ENV) received, unset '%s'\n", key);
 624                                         udev_add_property(udev, key, NULL);
 625                                 } else {
 626                                         info(udev, "udevd message (ENV) received, set '%s=%s'\n", key, val);
 627                                         udev_add_property(udev, key, val);
 628                                 }
 629                         } else {
 630                                 err(udev, "wrong key format '%s'\n", key);
 631                         }
 632                         free(key);
 633                 }
 634                 worker_kill(udev, 0);
 635         }
 636
 637         i = udev_ctrl_get_set_children_max(ctrl_msg);
 638         if (i >= 0) {
 639                 info(udev, "udevd message (SET_MAX_CHILDREN) received, children_max=%i\n", i);
 640                 children_max = i;
 641         }
 642
 643         settle_pid = udev_ctrl_get_settle(ctrl_msg);
 644         if (settle_pid > 0) {
 645                 info(udev, "udevd message (SETTLE) received\n");
 646                 kill(settle_pid, SIGUSR1);
 647                 settle_pid = 0;
 648         }
 649         udev_ctrl_msg_unref(ctrl_msg);
 650 }
 651
 652 /* read inotify messages */
 653 static int handle_inotify(struct udev *udev)
 654 {
 655         int nbytes, pos;
 656         char *buf;
 657         struct inotify_event *ev;
 658
 659         if ((ioctl(pfd[FD_INOTIFY].fd, FIONREAD, &nbytes) < 0) || (nbytes <= 0))
 660                 return 0;
 661
 662         buf = malloc(nbytes);
 663         if (buf == NULL) {
 664                 err(udev, "error getting buffer for inotify\n");
 665                 return -1;
 666         }
 667
 668         nbytes = read(pfd[FD_INOTIFY].fd, buf, nbytes);
 669
 670         for (pos = 0; pos < nbytes; pos += sizeof(struct inotify_event) + ev->len) {
 671                 struct udev_device *dev;
 672
 673                 ev = (struct inotify_event *)(buf + pos);
 674                 if (ev->len) {
 675                         const char *s;
 676
 677                         info(udev, "inotify event: %x for %s\n", ev->mask, ev->name);
 678                         s = strstr(ev->name, ".rules");
 679                         if (s == NULL)
 680                                 continue;
 681                         if (strlen(s) != strlen(".rules"))
 682                                 continue;
 683                         reload_config = true;
 684                         continue;
 685                 }
 686
 687                 dev = udev_watch_lookup(udev, ev->wd);
 688                 if (dev != NULL) {
 689                         info(udev, "inotify event: %x for %s\n", ev->mask, udev_device_get_devnode(dev));
 690                         if (ev->mask & IN_CLOSE_WRITE) {
 691                                 char filename[UTIL_PATH_SIZE];
 692                                 int fd;
 693
 694                                 info(udev, "device %s closed, synthesising 'change'\n", udev_device_get_devnode(dev));
 695                                 util_strscpyl(filename, sizeof(filename), udev_device_get_syspath(dev), "/uevent", NULL);
 696                                 fd = open(filename, O_WRONLY);
 697                                 if (fd < 0 || write(fd, "change", 6) < 0)
 698                                         info(udev, "error writing uevent: %m\n");
 699                                 close(fd);
 700                         }
 701                         if (ev->mask & IN_IGNORED)
 702                                 udev_watch_end(udev, dev);
 703
 704                         udev_device_unref(dev);
 705                 }
 706
 707         }
 708
 709         free(buf);
 710         return 0;
 711 }
 712
 713 static void handle_signal(struct udev *udev, int signo)
 714 {
 715         switch (signo) {
 716         case SIGINT:
 717         case SIGTERM:
 718                 udev_exit = true;
 719                 break;
 720         case SIGCHLD:
 721                 for (;;) {
 722                         pid_t pid;
 723                         int status;
 724                         struct udev_list_node *loop, *tmp;
 725
 726                         pid = waitpid(-1, &status, WNOHANG);
 727                         if (pid <= 0)
 728                                 break;
 729
 730                         udev_list_node_foreach_safe(loop, tmp, &worker_list) {
 731                                 struct worker *worker = node_to_worker(loop);
 732
 733                                 if (worker->pid != pid)
 734                                         continue;
 735
 736                                 info(udev, "worker [%u] exit\n", pid);
 737                                 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
 738                                         err(udev, "worker [%u] unexpectedly returned with status 0x%04x\n", pid, status);
 739                                         if (worker->event != NULL) {
 740                                                 err(udev, "worker [%u] failed while handling '%s'\n", pid, worker->event->devpath);
 741                                                 worker->event->exitcode = -32;
 742                                                 event_queue_delete(worker->event);
 743                                                 /* drop reference from running event */
 744                                                 worker_unref(worker);
 745                                         }
 746                                 }
 747                                 worker_unref(worker);
 748                                 break;
 749                         }
 750                 }
 751                 break;
 752         case SIGHUP:
 753                 reload_config = true;
 754                 break;
 755         }
 756 }
 757
 758 static void static_dev_create_from_modules(struct udev *udev)
 759 {
 760         struct utsname kernel;
 761         char modules[UTIL_PATH_SIZE];
 762         char buf[4096];
 763         FILE *f;
 764
 765         uname(&kernel);
 766         util_strscpyl(modules, sizeof(modules), "/lib/modules/", kernel.release, "/modules.devname", NULL);
 767         f = fopen(modules, "r");
 768         if (f == NULL)
 769                 return;
 770
 771         while (fgets(buf, sizeof(buf), f) != NULL) {
 772                 char *s;
 773                 const char *modname;
 774                 const char *devname;
 775                 const char *devno;
 776                 int maj, min;
 777                 char type;
 778                 mode_t mode;
 779                 char filename[UTIL_PATH_SIZE];
 780
 781                 if (buf[0] == '#')
 782                         continue;
 783
 784                 modname = buf;
 785                 s = strchr(modname, ' ');
 786                 if (s == NULL)
 787                         continue;
 788                 s[0] = '\0';
 789
 790                 devname = &s[1];
 791                 s = strchr(devname, ' ');
 792                 if (s == NULL)
 793                         continue;
 794                 s[0] = '\0';
 795
 796                 devno = &s[1];
 797                 s = strchr(devno, ' ');
 798                 if (s == NULL)
 799                         s = strchr(devno, '\n');
 800                 if (s != NULL)
 801                         s[0] = '\0';
 802                 if (sscanf(devno, "%c%u:%u", &type, &maj, &min) != 3)
 803                         continue;
 804
 805                 if (type == 'c')
 806                         mode = 0600 | S_IFCHR;
 807                 else if (type == 'b')
 808                         mode = 0600 | S_IFBLK;
 809                 else
 810                         continue;
 811
 812                 util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev), "/", devname, NULL);
 813                 util_create_path(udev, filename);
 814                 udev_selinux_setfscreatecon(udev, filename, mode);
 815                 info(udev, "mknod '%s' %c%u:%u\n", filename, type, maj, min);
 816                 if (mknod(filename, mode, makedev(maj, min)) < 0 && errno == EEXIST)
 817                         utimensat(AT_FDCWD, filename, NULL, 0);
 818                 udev_selinux_resetfscreatecon(udev);
 819         }
 820
 821         fclose(f);
 822 }
 823
 824 static int copy_dir(struct udev *udev, DIR *dir_from, DIR *dir_to, int maxdepth)
 825 {
 826         struct dirent *dent;
 827
 828         for (dent = readdir(dir_from); dent != NULL; dent = readdir(dir_from)) {
 829                 struct stat stats;
 830
 831                 if (dent->d_name[0] == '.')
 832                         continue;
 833                 if (fstatat(dirfd(dir_from), dent->d_name, &stats, AT_SYMLINK_NOFOLLOW) != 0)
 834                         continue;
 835
 836                 if (S_ISBLK(stats.st_mode) || S_ISCHR(stats.st_mode)) {
 837                         udev_selinux_setfscreateconat(udev, dirfd(dir_to), dent->d_name, stats.st_mode & 0777);
 838                         if (mknodat(dirfd(dir_to), dent->d_name, stats.st_mode, stats.st_rdev) == 0) {
 839                                 fchmodat(dirfd(dir_to), dent->d_name, stats.st_mode & 0777, 0);
 840                                 fchownat(dirfd(dir_to), dent->d_name, stats.st_uid, stats.st_gid, 0);
 841                         } else {
 842                                 utimensat(dirfd(dir_to), dent->d_name, NULL, 0);
 843                         }
 844                         udev_selinux_resetfscreatecon(udev);
 845                 } else if (S_ISLNK(stats.st_mode)) {
 846                         char target[UTIL_PATH_SIZE];
 847                         ssize_t len;
 848
 849                         len = readlinkat(dirfd(dir_from), dent->d_name, target, sizeof(target));
 850                         if (len <= 0 || len == (ssize_t)sizeof(target))
 851                                 continue;
 852                         target[len] = '\0';
 853                         udev_selinux_setfscreateconat(udev, dirfd(dir_to), dent->d_name, S_IFLNK);
 854                         if (symlinkat(target, dirfd(dir_to), dent->d_name) < 0 && errno == EEXIST)
 855                                 utimensat(dirfd(dir_to), dent->d_name, NULL, AT_SYMLINK_NOFOLLOW);
 856                         udev_selinux_resetfscreatecon(udev);
 857                 } else if (S_ISDIR(stats.st_mode)) {
 858                         DIR *dir2_from, *dir2_to;
 859
 860                         if (maxdepth == 0)
 861                                 continue;
 862
 863                         udev_selinux_setfscreateconat(udev, dirfd(dir_to), dent->d_name, S_IFDIR|0755);
 864                         mkdirat(dirfd(dir_to), dent->d_name, 0755);
 865                         udev_selinux_resetfscreatecon(udev);
 866
 867                         dir2_to = fdopendir(openat(dirfd(dir_to), dent->d_name, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC));
 868                         if (dir2_to == NULL)
 869                                 continue;
 870
 871                         dir2_from = fdopendir(openat(dirfd(dir_from), dent->d_name, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC));
 872                         if (dir2_from == NULL) {
 873                                 closedir(dir2_to);
 874                                 continue;
 875                         }
 876
 877                         copy_dir(udev, dir2_from, dir2_to, maxdepth-1);
 878
 879                         closedir(dir2_to);
 880                         closedir(dir2_from);
 881                 }
 882         }
 883
 884         return 0;
 885 }
 886
 887 static void static_dev_create_links(struct udev *udev, DIR *dir)
 888 {
 889         struct stdlinks {
 890                 const char *link;
 891                 const char *target;
 892         };
 893         static const struct stdlinks stdlinks[] = {
 894                 { "core", "/proc/kcore" },
 895                 { "fd", "/proc/self/fd" },
 896                 { "stdin", "/proc/self/fd/0" },
 897                 { "stdout", "/proc/self/fd/1" },
 898                 { "stderr", "/proc/self/fd/2" },
 899         };
 900         unsigned int i;
 901
 902         for (i = 0; i < ARRAY_SIZE(stdlinks); i++) {
 903                 struct stat sb;
 904
 905                 if (stat(stdlinks[i].target, &sb) == 0) {
 906                         udev_selinux_setfscreateconat(udev, dirfd(dir), stdlinks[i].link, S_IFLNK);
 907                         if (symlinkat(stdlinks[i].target, dirfd(dir), stdlinks[i].link) < 0 && errno == EEXIST)
 908                                 utimensat(dirfd(dir), stdlinks[i].link, NULL, AT_SYMLINK_NOFOLLOW);
 909                         udev_selinux_resetfscreatecon(udev);
 910                 }
 911         }
 912 }
 913
 914 static void static_dev_create_from_devices(struct udev *udev, DIR *dir)
 915 {
 916         DIR *dir_from;
 917
 918         dir_from = opendir(LIBEXECDIR "/devices");
 919         if (dir_from == NULL)
 920                 return;
 921         copy_dir(udev, dir_from, dir, 8);
 922         closedir(dir_from);
 923 }
 924
 925 static void static_dev_create(struct udev *udev)
 926 {
 927         DIR *dir;
 928
 929         dir = opendir(udev_get_dev_path(udev));
 930         if (dir == NULL)
 931                 return;
 932
 933         static_dev_create_links(udev, dir);
 934         static_dev_create_from_devices(udev, dir);
 935
 936         closedir(dir);
 937 }
 938
 939 static int mem_size_mb(void)
 940 {
 941         FILE *f;
 942         char buf[4096];
 943         long int memsize = -1;
 944
 945         f = fopen("/proc/meminfo", "r");
 946         if (f == NULL)
 947                 return -1;
 948
 949         while (fgets(buf, sizeof(buf), f) != NULL) {
 950                 long int value;
 951
 952                 if (sscanf(buf, "MemTotal: %ld kB", &value) == 1) {
 953                         memsize = value / 1024;
 954                         break;
 955                 }
 956         }
 957
 958         fclose(f);
 959         return memsize;
 960 }
 961
 962 static int init_notify(const char *state)
 963 {
 964         int fd = -1, r;
 965         struct msghdr msghdr;
 966         struct iovec iovec;
 967         union {
 968                 struct sockaddr sa;
 969                 struct sockaddr_un un;
 970         } sockaddr;
 971         const char *e;
 972
 973         if (!(e = getenv("NOTIFY_SOCKET"))) {
 974                 r = 0;
 975                 goto finish;
 976         }
 977
 978         /* Must be an abstract socket, or an absolute path */
 979         if ((e[0] != '@' && e[0] != '/') || e[1] == 0) {
 980                 r = -EINVAL;
 981                 goto finish;
 982         }
 983
 984         if ((fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0)) < 0) {
 985                 r = -errno;
 986                 goto finish;
 987         }
 988
 989         memset(&sockaddr, 0, sizeof(sockaddr));
 990         sockaddr.sa.sa_family = AF_UNIX;
 991         strncpy(sockaddr.un.sun_path, e, sizeof(sockaddr.un.sun_path));
 992
 993         if (sockaddr.un.sun_path[0] == '@')
 994                 sockaddr.un.sun_path[0] = 0;
 995
 996         memset(&iovec, 0, sizeof(iovec));
 997         iovec.iov_base = (char*) state;
 998         iovec.iov_len = strlen(state);
 999
1000         memset(&msghdr, 0, sizeof(msghdr));
1001         msghdr.msg_name = &sockaddr;
1002         msghdr.msg_namelen = sizeof(sa_family_t) + strlen(e);
1003         if (msghdr.msg_namelen > sizeof(struct sockaddr_un))
1004                 msghdr.msg_namelen = sizeof(struct sockaddr_un);
1005         msghdr.msg_iov = &iovec;
1006         msghdr.msg_iovlen = 1;
1007
1008         if (sendmsg(fd, &msghdr, MSG_NOSIGNAL) < 0) {
1009                 r = -errno;
1010                 goto finish;
1011         }
1012
1013         r = 0;
1014
1015 finish:
1016         if (fd >= 0)
1017                 close(fd);
1018
1019         return r;
1020 }
1021
1022 int main(int argc, char *argv[])
1023 {
1024         struct udev *udev;
1025         int fd;
1026         FILE *f;
1027         sigset_t mask;
1028         int daemonize = false;
1029         int resolve_names = 1;
1030         static const struct option options[] = {
1031                 { "daemon", no_argument, NULL, 'd' },
1032                 { "debug", no_argument, NULL, 'D' },
1033                 { "children-max", required_argument, NULL, 'c' },
1034                 { "exec-delay", required_argument, NULL, 'e' },
1035                 { "resolve-names", required_argument, NULL, 'N' },
1036                 { "help", no_argument, NULL, 'h' },
1037                 { "version", no_argument, NULL, 'V' },
1038                 {}
1039         };
1040         int rc = 1;
1041
1042         udev = udev_new();
1043         if (udev == NULL)
1044                 goto exit;
1045
1046         udev_log_init("udevd");
1047         udev_set_log_fn(udev, log_fn);
1048         info(udev, "version %s\n", VERSION);
1049         udev_selinux_init(udev);
1050
1051         for (;;) {
1052                 int option;
1053
1054                 option = getopt_long(argc, argv, "c:deDthV", options, NULL);
1055                 if (option == -1)
1056                         break;
1057
1058                 switch (option) {
1059                 case 'd':
1060                         daemonize = true;
1061                         break;
1062                 case 'c':
1063                         children_max = strtoul(optarg, NULL, 0);
1064                         break;
1065                 case 'e':
1066                         exec_delay = strtoul(optarg, NULL, 0);
1067                         break;
1068                 case 'D':
1069                         debug = true;
1070                         if (udev_get_log_priority(udev) < LOG_INFO)
1071                                 udev_set_log_priority(udev, LOG_INFO);
1072                         break;
1073                 case 'N':
1074                         if (strcmp (optarg, "early") == 0) {
1075                                 resolve_names = 1;
1076                         } else if (strcmp (optarg, "late") == 0) {
1077                                 resolve_names = 0;
1078                         } else if (strcmp (optarg, "never") == 0) {
1079                                 resolve_names = -1;
1080                         } else {
1081                                 fprintf(stderr, "resolve-names must be early, late or never\n");
1082                                 err(udev, "resolve-names must be early, late or never\n");
1083                                 goto exit;
1084                         }
1085                         break;
1086                 case 'h':
1087                         printf("Usage: udevd OPTIONS\n"
1088                                "  --daemon\n"
1089                                "  --debug\n"
1090                                "  --children-max=<maximum number of workers>\n"
1091                                "  --exec-delay=<seconds to wait before executing RUN=>\n"
1092                                "  --resolve-names=early|late|never\n"
1093                                "  --version\n"
1094                                "  --help\n"
1095                                "\n");
1096                         goto exit;
1097                 case 'V':
1098                         printf("%s\n", VERSION);
1099                         goto exit;
1100                 default:
1101                         goto exit;
1102                 }
1103         }
1104
1105         /*
1106          * read the kernel commandline, in case we need to get into debug mode
1107          *   udev.log-priority=<level>              syslog priority
1108          *   udev.children-max=<number of workers>  events are fully serialized if set to 1
1109          *
1110          */
1111         f = fopen("/proc/cmdline", "r");
1112         if (f != NULL) {
1113                 char cmdline[4096];
1114
1115                 if (fgets(cmdline, sizeof(cmdline), f) != NULL) {
1116                         char *pos;
1117
1118                         pos = strstr(cmdline, "udev.log-priority=");
1119                         if (pos != NULL) {
1120                                 pos += strlen("udev.log-priority=");
1121                                 udev_set_log_priority(udev, util_log_priority(pos));
1122                         }
1123
1124                         pos = strstr(cmdline, "udev.children-max=");
1125                         if (pos != NULL) {
1126                                 pos += strlen("udev.children-max=");
1127                                 children_max = strtoul(pos, NULL, 0);
1128                         }
1129
1130                         pos = strstr(cmdline, "udev.exec-delay=");
1131                         if (pos != NULL) {
1132                                 pos += strlen("udev.exec-delay=");
1133                                 exec_delay = strtoul(pos, NULL, 0);
1134                         }
1135                 }
1136                 fclose(f);
1137         }
1138
1139         if (getuid() != 0) {
1140                 fprintf(stderr, "root privileges required\n");
1141                 err(udev, "root privileges required\n");
1142                 goto exit;
1143         }
1144
1145         /* set umask before creating any file/directory */
1146         chdir("/");
1147         umask(022);
1148
1149         /* before opening new files, make sure std{in,out,err} fds are in a sane state */
1150         fd = open("/dev/null", O_RDWR);
1151         if (fd < 0) {
1152                 fprintf(stderr, "cannot open /dev/null\n");
1153                 err(udev, "cannot open /dev/null\n");
1154         }
1155         if (write(STDOUT_FILENO, 0, 0) < 0)
1156                 dup2(fd, STDOUT_FILENO);
1157         if (write(STDERR_FILENO, 0, 0) < 0)
1158                 dup2(fd, STDERR_FILENO);
1159
1160         udev_ctrl = udev_ctrl_new_from_socket(udev, UDEV_CTRL_SOCK_PATH);
1161         if (udev_ctrl == NULL) {
1162                 fprintf(stderr, "error initializing control socket");
1163                 err(udev, "error initializing udevd socket");
1164                 rc = 1;
1165                 goto exit;
1166         }
1167         if (udev_ctrl_enable_receiving(udev_ctrl) < 0) {
1168                 fprintf(stderr, "error binding control socket, seems udevd is already running\n");
1169                 err(udev, "error binding control socket, seems udevd is already running\n");
1170                 rc = 1;
1171                 goto exit;
1172         }
1173         pfd[FD_CONTROL].fd = udev_ctrl_get_fd(udev_ctrl);
1174
1175         monitor = udev_monitor_new_from_netlink(udev, "kernel");
1176         if (monitor == NULL || udev_monitor_enable_receiving(monitor) < 0) {
1177                 fprintf(stderr, "error initializing netlink socket\n");
1178                 err(udev, "error initializing netlink socket\n");
1179                 rc = 3;
1180                 goto exit;
1181         }
1182         udev_monitor_set_receive_buffer_size(monitor, 128*1024*1024);
1183         pfd[FD_NETLINK].fd = udev_monitor_get_fd(monitor);
1184
1185         pfd[FD_INOTIFY].fd = udev_watch_init(udev);
1186         if (pfd[FD_INOTIFY].fd < 0) {
1187                 fprintf(stderr, "error initializing inotify\n");
1188                 err(udev, "error initializing inotify\n");
1189                 rc = 4;
1190                 goto exit;
1191         }
1192
1193         if (udev_get_rules_path(udev) != NULL) {
1194                 inotify_add_watch(pfd[FD_INOTIFY].fd, udev_get_rules_path(udev),
1195                                   IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
1196         } else {
1197                 char filename[UTIL_PATH_SIZE];
1198                 struct stat statbuf;
1199
1200                 inotify_add_watch(pfd[FD_INOTIFY].fd, LIBEXECDIR "/rules.d",
1201                                   IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
1202                 inotify_add_watch(pfd[FD_INOTIFY].fd, SYSCONFDIR "/udev/rules.d",
1203                                   IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
1204
1205                 /* watch dynamic rules directory */
1206                 util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev), "/.udev/rules.d", NULL);
1207                 if (stat(filename, &statbuf) != 0) {
1208                         util_create_path(udev, filename);
1209                         udev_selinux_setfscreatecon(udev, filename, S_IFDIR|0755);
1210                         mkdir(filename, 0755);
1211                         udev_selinux_resetfscreatecon(udev);
1212                 }
1213                 inotify_add_watch(pfd[FD_INOTIFY].fd, filename,
1214                                   IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
1215         }
1216         udev_watch_restore(udev);
1217
1218         /* block and listen to all signals on signalfd */
1219         sigfillset(&mask);
1220         sigprocmask(SIG_SETMASK, &mask, &orig_sigmask);
1221         pfd[FD_SIGNAL].fd = signalfd(-1, &mask, 0);
1222         if (pfd[FD_SIGNAL].fd < 0) {
1223                 fprintf(stderr, "error getting signalfd\n");
1224                 err(udev, "error getting signalfd\n");
1225                 rc = 5;
1226                 goto exit;
1227         }
1228
1229         /* unnamed socket from workers to the main daemon */
1230         if (socketpair(AF_LOCAL, SOCK_DGRAM|SOCK_CLOEXEC, 0, worker_watch) < 0) {
1231                 fprintf(stderr, "error getting socketpair\n");
1232                 err(udev, "error getting socketpair\n");
1233                 rc = 6;
1234                 goto exit;
1235         }
1236         pfd[FD_WORKER].fd = worker_watch[READ_END];
1237
1238         rules = udev_rules_new(udev, resolve_names);
1239         if (rules == NULL) {
1240                 err(udev, "error reading rules\n");
1241                 goto exit;
1242         }
1243
1244         udev_queue_export = udev_queue_export_new(udev);
1245         if (udev_queue_export == NULL) {
1246                 err(udev, "error creating queue file\n");
1247                 goto exit;
1248         }
1249
1250         if (!debug) {
1251                 dup2(fd, STDIN_FILENO);
1252                 dup2(fd, STDOUT_FILENO);
1253                 dup2(fd, STDERR_FILENO);
1254         }
1255         if (fd > STDERR_FILENO)
1256                 close(fd);
1257
1258         if (daemonize) {
1259                 pid_t pid;
1260
1261                 pid = fork();
1262                 switch (pid) {
1263                 case 0:
1264                         break;
1265                 case -1:
1266                         err(udev, "fork of daemon failed: %m\n");
1267                         rc = 4;
1268                         goto exit;
1269                 default:
1270                         rc = 0;
1271                         goto exit;
1272                 }
1273         } else {
1274                 init_notify("READY=1");
1275         }
1276
1277         /* set scheduling priority for the main daemon process */
1278         setpriority(PRIO_PROCESS, 0, UDEVD_PRIORITY);
1279
1280         setsid();
1281
1282         f = fopen("/dev/kmsg", "w");
1283         if (f != NULL) {
1284                 fprintf(f, "<6>udev[%u]: starting version " VERSION "\n", getpid());
1285                 fclose(f);
1286         }
1287
1288         fd = open("/proc/self/oom_score_adj", O_RDWR);
1289         if (fd < 0) {
1290                 /* Fallback to old interface */
1291                 fd = open("/proc/self/oom_adj", O_RDWR);
1292                 if (fd < 0) {
1293                         err(udev, "error disabling OOM: %m\n");
1294                 } else {
1295                         /* OOM_DISABLE == -17 */
1296                         write(fd, "-17", 3);
1297                         close(fd);
1298                 }
1299         } else {
1300                 write(fd, "-1000", 5);
1301                 close(fd);
1302         }
1303
1304         if (children_max <= 0) {
1305                 int memsize = mem_size_mb();
1306
1307                 /* set value depending on the amount of RAM */
1308                 if (memsize > 0)
1309                         children_max = 128 + (memsize / 8);
1310                 else
1311                         children_max = 128;
1312         }
1313         info(udev, "set children_max to %u\n", children_max);
1314
1315         static_dev_create(udev);
1316         static_dev_create_from_modules(udev);
1317         udev_rules_apply_static_dev_perms(rules);
1318
1319         udev_list_init(&event_list);
1320         udev_list_init(&worker_list);
1321
1322         while (!udev_exit) {
1323                 int fdcount;
1324                 int timeout;
1325
1326                 /* set timeout to kill idle workers */
1327                 if (udev_list_is_empty(&event_list) && children > 2)
1328                         timeout = 3 * 1000;
1329                 else
1330                         timeout = -1;
1331                 /* wait for events */
1332                 fdcount = poll(pfd, ARRAY_SIZE(pfd), timeout);
1333                 if (fdcount < 0)
1334                         continue;
1335
1336                 /* timeout - kill idle workers */
1337                 if (fdcount == 0)
1338                         worker_kill(udev, 2);
1339
1340                 /* event has finished */
1341                 if (pfd[FD_WORKER].revents & POLLIN)
1342                         worker_returned();
1343
1344                 /* get kernel uevent */
1345                 if (pfd[FD_NETLINK].revents & POLLIN) {
1346                         struct udev_device *dev;
1347
1348                         dev = udev_monitor_receive_device(monitor);
1349                         if (dev != NULL)
1350                                 if (event_queue_insert(dev) < 0)
1351                                         udev_device_unref(dev);
1352                 }
1353
1354                 /* start new events */
1355                 if (!udev_list_is_empty(&event_list) && !stop_exec_queue)
1356                         events_start(udev);
1357
1358                 /* get signal */
1359                 if (pfd[FD_SIGNAL].revents & POLLIN) {
1360                         struct signalfd_siginfo fdsi;
1361                         ssize_t size;
1362
1363                         size = read(pfd[FD_SIGNAL].fd, &fdsi, sizeof(struct signalfd_siginfo));
1364                         if (size == sizeof(struct signalfd_siginfo))
1365                                 handle_signal(udev, fdsi.ssi_signo);
1366                 }
1367
1368                 /* device node and rules directory inotify watch */
1369                 if (pfd[FD_INOTIFY].revents & POLLIN)
1370                         handle_inotify(udev);
1371
1372                 /*
1373                  * get control message
1374                  *
1375                  * This needs to be after the inotify handling, to make sure,
1376                  * that the settle signal is send back after the possibly generated
1377                  * "change" events by the inotify device node watch.
1378                  */
1379                 if (pfd[FD_CONTROL].revents & POLLIN)
1380                         handle_ctrl_msg(udev_ctrl);
1381
1382                 /* rules changed, set by inotify or a HUP signal */
1383                 if (reload_config) {
1384                         struct udev_rules *rules_new;
1385
1386                         worker_kill(udev, 0);
1387                         rules_new = udev_rules_new(udev, resolve_names);
1388                         if (rules_new != NULL) {
1389                                 udev_rules_unref(rules);
1390                                 rules = rules_new;
1391                         }
1392                         reload_config = 0;
1393                 }
1394         }
1395
1396         udev_queue_export_cleanup(udev_queue_export);
1397         rc = 0;
1398 exit:
1399         udev_queue_export_unref(udev_queue_export);
1400         udev_rules_unref(rules);
1401         udev_ctrl_unref(udev_ctrl);
1402         if (pfd[FD_SIGNAL].fd >= 0)
1403                 close(pfd[FD_SIGNAL].fd);
1404         if (worker_watch[READ_END] >= 0)
1405                 close(worker_watch[READ_END]);
1406         if (worker_watch[WRITE_END] >= 0)
1407                 close(worker_watch[WRITE_END]);
1408         udev_monitor_unref(monitor);
1409         udev_selinux_exit(udev);
1410         udev_unref(udev);
1411         udev_log_close();
1412         return rc;
1413 }