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                 return;
 232         /* worker + event reference */
 233         worker->refcount = 2;
 234         worker->udev = event->udev;
 235
 236         pid = fork();
 237         switch (pid) {
 238         case 0: {
 239                 sigset_t sigmask;
 240                 struct udev_device *dev;
 241                 struct pollfd pmon = {
 242                         .fd = udev_monitor_get_fd(worker_monitor),
 243                         .events = POLLIN,
 244                 };
 245
 246                 udev_queue_export_unref(udev_queue_export);
 247                 udev_monitor_unref(monitor);
 248                 udev_ctrl_unref(udev_ctrl);
 249                 close(pfd[FD_SIGNAL].fd);
 250                 close(worker_watch[READ_END]);
 251                 udev_log_close();
 252                 udev_log_init("udevd-work");
 253                 setpriority(PRIO_PROCESS, 0, UDEV_PRIORITY);
 254
 255                 /* set signal handlers */
 256                 memset(&act, 0x00, sizeof(act));
 257                 act.sa_handler = event_sig_handler;
 258                 sigemptyset (&act.sa_mask);
 259                 act.sa_flags = 0;
 260                 sigaction(SIGTERM, &act, NULL);
 261                 sigaction(SIGALRM, &act, NULL);
 262
 263                 /* unblock SIGALRM */
 264                 sigfillset(&sigmask);
 265                 sigdelset(&sigmask, SIGALRM);
 266                 sigprocmask(SIG_SETMASK, &sigmask, NULL);
 267                 /* SIGTERM is unblocked in ppoll() */
 268                 sigdelset(&sigmask, SIGTERM);
 269
 270                 /* request TERM signal if parent exits */
 271                 prctl(PR_SET_PDEATHSIG, SIGTERM);
 272
 273                 /* initial device */
 274                 dev = event->dev;
 275
 276                 do {
 277                         struct udev_event *udev_event;
 278                         struct worker_message msg = {};
 279                         int err;
 280                         int failed = 0;
 281
 282                         info(event->udev, "seq %llu running\n", udev_device_get_seqnum(dev));
 283                         udev_event = udev_event_new(dev);
 284                         if (udev_event == NULL)
 285                                 _exit(3);
 286
 287                         /* set timeout to prevent hanging processes */
 288                         alarm(UDEV_EVENT_TIMEOUT);
 289
 290                         if (exec_delay > 0)
 291                                 udev_event->exec_delay = exec_delay;
 292
 293                         /* apply rules, create node, symlinks */
 294                         err = udev_event_execute_rules(udev_event, rules);
 295
 296                         /* rules may change/disable the timeout */
 297                         if (udev_device_get_event_timeout(dev) >= 0)
 298                                 alarm(udev_device_get_event_timeout(dev));
 299
 300                         if (err == 0)
 301                                 failed = udev_event_execute_run(udev_event, &orig_sigmask);
 302
 303                         alarm(0);
 304
 305                         /* apply/restore inotify watch */
 306                         if (err == 0 && udev_event->inotify_watch) {
 307                                 udev_watch_begin(udev_event->udev, dev);
 308                                 udev_device_update_db(dev);
 309                         }
 310
 311                         /* send processed event back to libudev listeners */
 312                         udev_monitor_send_device(worker_monitor, NULL, dev);
 313
 314                         /* send udevd the result of the event execution */
 315                         if (err != 0)
 316                                 msg.exitcode = err;
 317                         else if (failed != 0)
 318                                 msg.exitcode = failed;
 319                         msg.pid = getpid();
 320                         send(worker_watch[WRITE_END], &msg, sizeof(struct worker_message), 0);
 321
 322                         info(event->udev, "seq %llu processed with %i\n", udev_device_get_seqnum(dev), err);
 323                         udev_event_unref(udev_event);
 324                         udev_device_unref(dev);
 325                         dev = NULL;
 326
 327                         /* wait for more device messages or signal from udevd */
 328                         while (!worker_exit) {
 329                                 int fdcount;
 330
 331                                 fdcount = ppoll(&pmon, 1, NULL, &sigmask);
 332                                 if (fdcount < 0)
 333                                         continue;
 334
 335                                 if (pmon.revents & POLLIN) {
 336                                         dev = udev_monitor_receive_device(worker_monitor);
 337                                         if (dev != NULL)
 338                                                 break;
 339                                 }
 340                         }
 341                 } while (dev != NULL);
 342
 343                 udev_monitor_unref(worker_monitor);
 344                 udev_log_close();
 345                 exit(0);
 346         }
 347         case -1:
 348                 udev_monitor_unref(worker_monitor);
 349                 event->state = EVENT_QUEUED;
 350                 free(worker);
 351                 err(event->udev, "fork of child failed: %m\n");
 352                 break;
 353         default:
 354                 /* close monitor, but keep address around */
 355                 udev_monitor_disconnect(worker_monitor);
 356                 worker->monitor = worker_monitor;
 357                 worker->pid = pid;
 358                 worker->state = WORKER_RUNNING;
 359                 worker->event = event;
 360                 event->state = EVENT_RUNNING;
 361                 udev_list_node_append(&worker->node, &worker_list);
 362                 children++;
 363                 info(event->udev, "seq %llu forked new worker [%u]\n", udev_device_get_seqnum(event->dev), pid);
 364                 break;
 365         }
 366 }
 367
 368 static void event_run(struct event *event, bool force)
 369 {
 370         struct udev_list_node *loop;
 371
 372         udev_list_node_foreach(loop, &worker_list) {
 373                 struct worker *worker = node_to_worker(loop);
 374                 ssize_t count;
 375
 376                 if (worker->state != WORKER_IDLE)
 377                         continue;
 378
 379                 count = udev_monitor_send_device(monitor, worker->monitor, event->dev);
 380                 if (count < 0) {
 381                         err(event->udev, "worker [%u] did not accept message %zi (%m), kill it\n", worker->pid, count);
 382                         kill(worker->pid, SIGKILL);
 383                         worker->state = WORKER_KILLED;
 384                         continue;
 385                 }
 386                 worker_ref(worker);
 387                 worker->event = event;
 388                 worker->state = WORKER_RUNNING;
 389                 event->state = EVENT_RUNNING;
 390                 return;
 391         }
 392
 393         if (!force && children >= children_max) {
 394                 if (children_max > 1)
 395                         info(event->udev, "maximum number (%i) of children reached\n", children);
 396                 return;
 397         }
 398
 399         /* start new worker and pass initial device */
 400         worker_new(event);
 401 }
 402
 403 static void event_queue_insert(struct udev_device *dev)
 404 {
 405         struct event *event;
 406
 407         event = calloc(1, sizeof(struct event));
 408         if (event == NULL)
 409                 return;
 410
 411         event->udev = udev_device_get_udev(dev);
 412         event->dev = dev;
 413         event->seqnum = udev_device_get_seqnum(dev);
 414         event->devpath = udev_device_get_devpath(dev);
 415         event->devpath_len = strlen(event->devpath);
 416         event->devpath_old = udev_device_get_devpath_old(dev);
 417         event->devnum = udev_device_get_devnum(dev);
 418         event->is_block = (strcmp("block", udev_device_get_subsystem(dev)) == 0);
 419
 420         udev_queue_export_device_queued(udev_queue_export, dev);
 421         info(event->udev, "seq %llu queued, '%s' '%s'\n", udev_device_get_seqnum(dev),
 422              udev_device_get_action(dev), udev_device_get_subsystem(dev));
 423
 424         event->state = EVENT_QUEUED;
 425         udev_list_node_append(&event->node, &event_list);
 426
 427         /* run all events with a timeout set immediately */
 428         if (udev_device_get_timeout(dev) > 0) {
 429                 event_run(event, true);
 430                 return;
 431         }
 432 }
 433
 434 static void worker_kill(struct udev *udev, int retain)
 435 {
 436         struct udev_list_node *loop;
 437         int max;
 438
 439         if (children <= retain)
 440                 return;
 441
 442         max = children - retain;
 443
 444         udev_list_node_foreach(loop, &worker_list) {
 445                 struct worker *worker = node_to_worker(loop);
 446
 447                 if (max-- <= 0)
 448                         break;
 449
 450                 if (worker->state == WORKER_KILLED)
 451                         continue;
 452
 453                 worker->state = WORKER_KILLED;
 454                 kill(worker->pid, SIGTERM);
 455         }
 456 }
 457
 458 /* lookup event for identical, parent, child device */
 459 static bool is_devpath_busy(struct event *event)
 460 {
 461         struct udev_list_node *loop;
 462         size_t common;
 463
 464         /* check if queue contains events we depend on */
 465         udev_list_node_foreach(loop, &event_list) {
 466                 struct event *loop_event = node_to_event(loop);
 467
 468                 /* we already found a later event, earlier can not block us, no need to check again */
 469                 if (loop_event->seqnum < event->delaying_seqnum)
 470                         continue;
 471
 472                 /* event we checked earlier still exists, no need to check again */
 473                 if (loop_event->seqnum == event->delaying_seqnum)
 474                         return true;
 475
 476                 /* found ourself, no later event can block us */
 477                 if (loop_event->seqnum >= event->seqnum)
 478                         break;
 479
 480                 /* check major/minor */
 481                 if (major(event->devnum) != 0 && event->devnum == loop_event->devnum && event->is_block == loop_event->is_block)
 482                         return true;
 483
 484                 /* check our old name */
 485                 if (event->devpath_old != NULL && strcmp(loop_event->devpath, event->devpath_old) == 0) {
 486                         event->delaying_seqnum = loop_event->seqnum;
 487                         return true;
 488                 }
 489
 490                 /* compare devpath */
 491                 common = MIN(loop_event->devpath_len, event->devpath_len);
 492
 493                 /* one devpath is contained in the other? */
 494                 if (memcmp(loop_event->devpath, event->devpath, common) != 0)
 495                         continue;
 496
 497                 /* identical device event found */
 498                 if (loop_event->devpath_len == event->devpath_len) {
 499                         event->delaying_seqnum = loop_event->seqnum;
 500                         return true;
 501                 }
 502
 503                 /* parent device event found */
 504                 if (event->devpath[common] == '/') {
 505                         event->delaying_seqnum = loop_event->seqnum;
 506                         return true;
 507                 }
 508
 509                 /* child device event found */
 510                 if (loop_event->devpath[common] == '/') {
 511                         event->delaying_seqnum = loop_event->seqnum;
 512                         return true;
 513                 }
 514
 515                 /* no matching device */
 516                 continue;
 517         }
 518
 519         return false;
 520 }
 521
 522 static void events_start(struct udev *udev)
 523 {
 524         struct udev_list_node *loop;
 525
 526         udev_list_node_foreach(loop, &event_list) {
 527                 struct event *event = node_to_event(loop);
 528
 529                 if (event->state != EVENT_QUEUED)
 530                         continue;
 531
 532                 /* do not start event if parent or child event is still running */
 533                 if (is_devpath_busy(event)) {
 534                         dbg(udev, "delay seq %llu (%s)\n", event->seqnum, event->devpath);
 535                         continue;
 536                 }
 537
 538                 event_run(event, false);
 539         }
 540 }
 541
 542 static void worker_returned(void)
 543 {
 544         for (;;) {
 545                 struct worker_message msg;
 546                 ssize_t size;
 547                 struct udev_list_node *loop;
 548
 549                 size = recv(pfd[FD_WORKER].fd, &msg, sizeof(struct worker_message), MSG_DONTWAIT);
 550                 if (size != sizeof(struct worker_message))
 551                         break;
 552
 553                 /* lookup worker who sent the signal */
 554                 udev_list_node_foreach(loop, &worker_list) {
 555                         struct worker *worker = node_to_worker(loop);
 556
 557                         if (worker->pid != msg.pid)
 558                                 continue;
 559
 560                         /* worker returned */
 561                         worker->event->exitcode = msg.exitcode;
 562                         event_queue_delete(worker->event);
 563                         worker->event = NULL;
 564                         if (worker->state != WORKER_KILLED)
 565                                 worker->state = WORKER_IDLE;
 566                         worker_unref(worker);
 567                         break;
 568                 }
 569         }
 570 }
 571
 572 /* receive the udevd message from userspace */
 573 static void handle_ctrl_msg(struct udev_ctrl *uctrl)
 574 {
 575         struct udev *udev = udev_ctrl_get_udev(uctrl);
 576         struct udev_ctrl_msg *ctrl_msg;
 577         const char *str;
 578         int i;
 579
 580         ctrl_msg = udev_ctrl_receive_msg(uctrl);
 581         if (ctrl_msg == NULL)
 582                 return;
 583
 584         i = udev_ctrl_get_set_log_level(ctrl_msg);
 585         if (i >= 0) {
 586                 info(udev, "udevd message (SET_LOG_PRIORITY) received, log_priority=%i\n", i);
 587                 udev_set_log_priority(udev, i);
 588                 worker_kill(udev, 0);
 589         }
 590
 591         if (udev_ctrl_get_stop_exec_queue(ctrl_msg) > 0) {
 592                 info(udev, "udevd message (STOP_EXEC_QUEUE) received\n");
 593                 stop_exec_queue = true;
 594         }
 595
 596         if (udev_ctrl_get_start_exec_queue(ctrl_msg) > 0) {
 597                 info(udev, "udevd message (START_EXEC_QUEUE) received\n");
 598                 stop_exec_queue = false;
 599         }
 600
 601         if (udev_ctrl_get_reload_rules(ctrl_msg) > 0) {
 602                 info(udev, "udevd message (RELOAD_RULES) received\n");
 603                 reload_config = true;
 604         }
 605
 606         str = udev_ctrl_get_set_env(ctrl_msg);
 607         if (str != NULL) {
 608                 char *key;
 609
 610                 key = strdup(str);
 611                 if (key != NULL) {
 612                         char *val;
 613
 614                         val = strchr(key, '=');
 615                         if (val != NULL) {
 616                                 val[0] = '\0';
 617                                 val = &val[1];
 618                                 if (val[0] == '\0') {
 619                                         info(udev, "udevd message (ENV) received, unset '%s'\n", key);
 620                                         udev_add_property(udev, key, NULL);
 621                                 } else {
 622                                         info(udev, "udevd message (ENV) received, set '%s=%s'\n", key, val);
 623                                         udev_add_property(udev, key, val);
 624                                 }
 625                         } else {
 626                                 err(udev, "wrong key format '%s'\n", key);
 627                         }
 628                         free(key);
 629                 }
 630                 worker_kill(udev, 0);
 631         }
 632
 633         i = udev_ctrl_get_set_children_max(ctrl_msg);
 634         if (i >= 0) {
 635                 info(udev, "udevd message (SET_MAX_CHILDREN) received, children_max=%i\n", i);
 636                 children_max = i;
 637         }
 638
 639         settle_pid = udev_ctrl_get_settle(ctrl_msg);
 640         if (settle_pid > 0) {
 641                 info(udev, "udevd message (SETTLE) received\n");
 642                 kill(settle_pid, SIGUSR1);
 643                 settle_pid = 0;
 644         }
 645         udev_ctrl_msg_unref(ctrl_msg);
 646 }
 647
 648 /* read inotify messages */
 649 static int handle_inotify(struct udev *udev)
 650 {
 651         int nbytes, pos;
 652         char *buf;
 653         struct inotify_event *ev;
 654
 655         if ((ioctl(pfd[FD_INOTIFY].fd, FIONREAD, &nbytes) < 0) || (nbytes <= 0))
 656                 return 0;
 657
 658         buf = malloc(nbytes);
 659         if (buf == NULL) {
 660                 err(udev, "error getting buffer for inotify\n");
 661                 return -1;
 662         }
 663
 664         nbytes = read(pfd[FD_INOTIFY].fd, buf, nbytes);
 665
 666         for (pos = 0; pos < nbytes; pos += sizeof(struct inotify_event) + ev->len) {
 667                 struct udev_device *dev;
 668
 669                 ev = (struct inotify_event *)(buf + pos);
 670                 if (ev->len) {
 671                         const char *s;
 672
 673                         info(udev, "inotify event: %x for %s\n", ev->mask, ev->name);
 674                         s = strstr(ev->name, ".rules");
 675                         if (s == NULL)
 676                                 continue;
 677                         if (strlen(s) != strlen(".rules"))
 678                                 continue;
 679                         reload_config = true;
 680                         continue;
 681                 }
 682
 683                 dev = udev_watch_lookup(udev, ev->wd);
 684                 if (dev != NULL) {
 685                         info(udev, "inotify event: %x for %s\n", ev->mask, udev_device_get_devnode(dev));
 686                         if (ev->mask & IN_CLOSE_WRITE) {
 687                                 char filename[UTIL_PATH_SIZE];
 688                                 int fd;
 689
 690                                 info(udev, "device %s closed, synthesising 'change'\n", udev_device_get_devnode(dev));
 691                                 util_strscpyl(filename, sizeof(filename), udev_device_get_syspath(dev), "/uevent", NULL);
 692                                 fd = open(filename, O_WRONLY);
 693                                 if (fd < 0 || write(fd, "change", 6) < 0)
 694                                         info(udev, "error writing uevent: %m\n");
 695                                 close(fd);
 696                         }
 697                         if (ev->mask & IN_IGNORED)
 698                                 udev_watch_end(udev, dev);
 699
 700                         udev_device_unref(dev);
 701                 }
 702
 703         }
 704
 705         free(buf);
 706         return 0;
 707 }
 708
 709 static void handle_signal(struct udev *udev, int signo)
 710 {
 711         switch (signo) {
 712         case SIGINT:
 713         case SIGTERM:
 714                 udev_exit = true;
 715                 break;
 716         case SIGCHLD:
 717                 for (;;) {
 718                         pid_t pid;
 719                         int status;
 720                         struct udev_list_node *loop, *tmp;
 721
 722                         pid = waitpid(-1, &status, WNOHANG);
 723                         if (pid <= 0)
 724                                 break;
 725
 726                         udev_list_node_foreach_safe(loop, tmp, &worker_list) {
 727                                 struct worker *worker = node_to_worker(loop);
 728
 729                                 if (worker->pid != pid)
 730                                         continue;
 731
 732                                 info(udev, "worker [%u] exit\n", pid);
 733                                 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
 734                                         err(udev, "worker [%u] unexpectedly returned with status 0x%04x\n", pid, status);
 735                                         if (worker->event != NULL) {
 736                                                 err(udev, "worker [%u] failed while handling '%s'\n", pid, worker->event->devpath);
 737                                                 worker->event->exitcode = -32;
 738                                                 event_queue_delete(worker->event);
 739                                                 /* drop reference from running event */
 740                                                 worker_unref(worker);
 741                                         }
 742                                 }
 743                                 worker_unref(worker);
 744                                 break;
 745                         }
 746                 }
 747                 break;
 748         case SIGHUP:
 749                 reload_config = true;
 750                 break;
 751         }
 752 }
 753
 754 static void static_dev_create_from_modules(struct udev *udev)
 755 {
 756         struct utsname kernel;
 757         char modules[UTIL_PATH_SIZE];
 758         char buf[4096];
 759         FILE *f;
 760
 761         uname(&kernel);
 762         util_strscpyl(modules, sizeof(modules), "/lib/modules/", kernel.release, "/modules.devname", NULL);
 763         f = fopen(modules, "r");
 764         if (f == NULL)
 765                 return;
 766
 767         while (fgets(buf, sizeof(buf), f) != NULL) {
 768                 char *s;
 769                 const char *modname;
 770                 const char *devname;
 771                 const char *devno;
 772                 int maj, min;
 773                 char type;
 774                 mode_t mode;
 775                 char filename[UTIL_PATH_SIZE];
 776
 777                 if (buf[0] == '#')
 778                         continue;
 779
 780                 modname = buf;
 781                 s = strchr(modname, ' ');
 782                 if (s == NULL)
 783                         continue;
 784                 s[0] = '\0';
 785
 786                 devname = &s[1];
 787                 s = strchr(devname, ' ');
 788                 if (s == NULL)
 789                         continue;
 790                 s[0] = '\0';
 791
 792                 devno = &s[1];
 793                 s = strchr(devno, ' ');
 794                 if (s == NULL)
 795                         s = strchr(devno, '\n');
 796                 if (s != NULL)
 797                         s[0] = '\0';
 798                 if (sscanf(devno, "%c%u:%u", &type, &maj, &min) != 3)
 799                         continue;
 800
 801                 if (type == 'c')
 802                         mode = 0600 | S_IFCHR;
 803                 else if (type == 'b')
 804                         mode = 0600 | S_IFBLK;
 805                 else
 806                         continue;
 807
 808                 util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev), "/", devname, NULL);
 809                 util_create_path(udev, filename);
 810                 udev_selinux_setfscreatecon(udev, filename, mode);
 811                 info(udev, "mknod '%s' %c%u:%u\n", filename, type, maj, min);
 812                 if (mknod(filename, mode, makedev(maj, min)) < 0 && errno == EEXIST)
 813                         utimensat(AT_FDCWD, filename, NULL, 0);
 814                 udev_selinux_resetfscreatecon(udev);
 815         }
 816
 817         fclose(f);
 818 }
 819
 820 static int copy_dir(struct udev *udev, DIR *dir_from, DIR *dir_to, int maxdepth)
 821 {
 822         struct dirent *dent;
 823
 824         for (dent = readdir(dir_from); dent != NULL; dent = readdir(dir_from)) {
 825                 struct stat stats;
 826
 827                 if (dent->d_name[0] == '.')
 828                         continue;
 829                 if (fstatat(dirfd(dir_from), dent->d_name, &stats, AT_SYMLINK_NOFOLLOW) != 0)
 830                         continue;
 831
 832                 if (S_ISBLK(stats.st_mode) || S_ISCHR(stats.st_mode)) {
 833                         udev_selinux_setfscreateconat(udev, dirfd(dir_to), dent->d_name, stats.st_mode & 0777);
 834                         if (mknodat(dirfd(dir_to), dent->d_name, stats.st_mode, stats.st_rdev) == 0) {
 835                                 fchmodat(dirfd(dir_to), dent->d_name, stats.st_mode & 0777, 0);
 836                                 fchownat(dirfd(dir_to), dent->d_name, stats.st_uid, stats.st_gid, 0);
 837                         } else {
 838                                 utimensat(dirfd(dir_to), dent->d_name, NULL, 0);
 839                         }
 840                         udev_selinux_resetfscreatecon(udev);
 841                 } else if (S_ISLNK(stats.st_mode)) {
 842                         char target[UTIL_PATH_SIZE];
 843                         ssize_t len;
 844
 845                         len = readlinkat(dirfd(dir_from), dent->d_name, target, sizeof(target));
 846                         if (len <= 0 || len == (ssize_t)sizeof(target))
 847                                 continue;
 848                         target[len] = '\0';
 849                         udev_selinux_setfscreateconat(udev, dirfd(dir_to), dent->d_name, S_IFLNK);
 850                         if (symlinkat(target, dirfd(dir_to), dent->d_name) < 0 && errno == EEXIST)
 851                                 utimensat(dirfd(dir_to), dent->d_name, NULL, AT_SYMLINK_NOFOLLOW);
 852                         udev_selinux_resetfscreatecon(udev);
 853                 } else if (S_ISDIR(stats.st_mode)) {
 854                         DIR *dir2_from, *dir2_to;
 855
 856                         if (maxdepth == 0)
 857                                 continue;
 858
 859                         udev_selinux_setfscreateconat(udev, dirfd(dir_to), dent->d_name, S_IFDIR|0755);
 860                         mkdirat(dirfd(dir_to), dent->d_name, 0755);
 861                         udev_selinux_resetfscreatecon(udev);
 862
 863                         dir2_to = fdopendir(openat(dirfd(dir_to), dent->d_name, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC));
 864                         if (dir2_to == NULL)
 865                                 continue;
 866
 867                         dir2_from = fdopendir(openat(dirfd(dir_from), dent->d_name, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC));
 868                         if (dir2_from == NULL) {
 869                                 closedir(dir2_to);
 870                                 continue;
 871                         }
 872
 873                         copy_dir(udev, dir2_from, dir2_to, maxdepth-1);
 874
 875                         closedir(dir2_to);
 876                         closedir(dir2_from);
 877                 }
 878         }
 879
 880         return 0;
 881 }
 882
 883 static void static_dev_create_links(struct udev *udev, DIR *dir)
 884 {
 885         struct stdlinks {
 886                 const char *link;
 887                 const char *target;
 888         };
 889         static const struct stdlinks stdlinks[] = {
 890                 { "core", "/proc/kcore" },
 891                 { "fd", "/proc/self/fd" },
 892                 { "stdin", "/proc/self/fd/0" },
 893                 { "stdout", "/proc/self/fd/1" },
 894                 { "stderr", "/proc/self/fd/2" },
 895         };
 896         unsigned int i;
 897
 898         for (i = 0; i < ARRAY_SIZE(stdlinks); i++) {
 899                 udev_selinux_setfscreateconat(udev, dirfd(dir), stdlinks[i].link, S_IFLNK);
 900                 if (symlinkat(stdlinks[i].target, dirfd(dir), stdlinks[i].link) < 0 && errno == EEXIST)
 901                         utimensat(dirfd(dir), stdlinks[i].link, NULL, AT_SYMLINK_NOFOLLOW);
 902                 udev_selinux_resetfscreatecon(udev);
 903         }
 904 }
 905
 906 static void static_dev_create_from_devices(struct udev *udev, DIR *dir)
 907 {
 908         DIR *dir_from;
 909
 910         dir_from = opendir(LIBEXECDIR "/devices");
 911         if (dir_from == NULL)
 912                 return;
 913         copy_dir(udev, dir_from, dir, 8);
 914         closedir(dir_from);
 915 }
 916
 917 static void static_dev_create(struct udev *udev)
 918 {
 919         DIR *dir;
 920
 921         dir = opendir(udev_get_dev_path(udev));
 922         if (dir == NULL)
 923                 return;
 924
 925         static_dev_create_links(udev, dir);
 926         static_dev_create_from_devices(udev, dir);
 927
 928         closedir(dir);
 929 }
 930
 931 static int mem_size_mb(void)
 932 {
 933         FILE *f;
 934         char buf[4096];
 935         long int memsize = -1;
 936
 937         f = fopen("/proc/meminfo", "r");
 938         if (f == NULL)
 939                 return -1;
 940
 941         while (fgets(buf, sizeof(buf), f) != NULL) {
 942                 long int value;
 943
 944                 if (sscanf(buf, "MemTotal: %ld kB", &value) == 1) {
 945                         memsize = value / 1024;
 946                         break;
 947                 }
 948         }
 949
 950         fclose(f);
 951         return memsize;
 952 }
 953
 954 static int init_notify(const char *state)
 955 {
 956         int fd = -1, r;
 957         struct msghdr msghdr;
 958         struct iovec iovec;
 959         struct ucred *ucred;
 960         union {
 961                 struct sockaddr sa;
 962                 struct sockaddr_un un;
 963         } sockaddr;
 964         union {
 965                 struct cmsghdr cmsghdr;
 966                 uint8_t buf[CMSG_SPACE(sizeof(struct ucred))];
 967         } control;
 968         const char *e;
 969
 970         if (!(e = getenv("NOTIFY_SOCKET"))) {
 971                 r = 0;
 972                 goto finish;
 973         }
 974
 975         /* Must be an abstract socket, or an absolute path */
 976         if ((e[0] != '@' && e[0] != '/') || e[1] == 0) {
 977                 r = -EINVAL;
 978                 goto finish;
 979         }
 980
 981         if ((fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0)) < 0) {
 982                 r = -errno;
 983                 goto finish;
 984         }
 985
 986         memset(&sockaddr, 0, sizeof(sockaddr));
 987         sockaddr.sa.sa_family = AF_UNIX;
 988         strncpy(sockaddr.un.sun_path, e, sizeof(sockaddr.un.sun_path));
 989
 990         if (sockaddr.un.sun_path[0] == '@')
 991                 sockaddr.un.sun_path[0] = 0;
 992
 993         memset(&iovec, 0, sizeof(iovec));
 994         iovec.iov_base = (char*) state;
 995         iovec.iov_len = strlen(state);
 996
 997         memset(&control, 0, sizeof(control));
 998         control.cmsghdr.cmsg_level = SOL_SOCKET;
 999         control.cmsghdr.cmsg_type = SCM_CREDENTIALS;
1000         control.cmsghdr.cmsg_len = CMSG_LEN(sizeof(struct ucred));
1001
1002         ucred = (struct ucred*) CMSG_DATA(&control.cmsghdr);
1003         ucred->pid = getpid();
1004         ucred->uid = getuid();
1005         ucred->gid = getgid();
1006
1007         memset(&msghdr, 0, sizeof(msghdr));
1008         msghdr.msg_name = &sockaddr;
1009         msghdr.msg_namelen = sizeof(sa_family_t) + strlen(e);
1010         if (msghdr.msg_namelen > sizeof(struct sockaddr_un))
1011                 msghdr.msg_namelen = sizeof(struct sockaddr_un);
1012         msghdr.msg_iov = &iovec;
1013         msghdr.msg_iovlen = 1;
1014         msghdr.msg_control = &control;
1015         msghdr.msg_controllen = control.cmsghdr.cmsg_len;
1016
1017         if (sendmsg(fd, &msghdr, MSG_NOSIGNAL) < 0) {
1018                 r = -errno;
1019                 goto finish;
1020         }
1021
1022         r = 0;
1023
1024 finish:
1025         if (fd >= 0)
1026                 close(fd);
1027
1028         return r;
1029 }
1030
1031 int main(int argc, char *argv[])
1032 {
1033         struct udev *udev;
1034         int fd;
1035         FILE *f;
1036         sigset_t mask;
1037         int daemonize = false;
1038         int resolve_names = 1;
1039         static const struct option options[] = {
1040                 { "daemon", no_argument, NULL, 'd' },
1041                 { "debug", no_argument, NULL, 'D' },
1042                 { "children-max", required_argument, NULL, 'c' },
1043                 { "exec-delay", required_argument, NULL, 'e' },
1044                 { "resolve-names", required_argument, NULL, 'N' },
1045                 { "help", no_argument, NULL, 'h' },
1046                 { "version", no_argument, NULL, 'V' },
1047                 {}
1048         };
1049         int rc = 1;
1050
1051         udev = udev_new();
1052         if (udev == NULL)
1053                 goto exit;
1054
1055         udev_log_init("udevd");
1056         udev_set_log_fn(udev, log_fn);
1057         info(udev, "version %s\n", VERSION);
1058         udev_selinux_init(udev);
1059
1060         for (;;) {
1061                 int option;
1062
1063                 option = getopt_long(argc, argv, "cdeDthV", options, NULL);
1064                 if (option == -1)
1065                         break;
1066
1067                 switch (option) {
1068                 case 'd':
1069                         daemonize = true;
1070                         break;
1071                 case 'c':
1072                         children_max = strtoul(optarg, NULL, 0);
1073                         break;
1074                 case 'e':
1075                         exec_delay = strtoul(optarg, NULL, 0);
1076                         break;
1077                 case 'D':
1078                         debug = true;
1079                         if (udev_get_log_priority(udev) < LOG_INFO)
1080                                 udev_set_log_priority(udev, LOG_INFO);
1081                         break;
1082                 case 'N':
1083                         if (strcmp (optarg, "early") == 0) {
1084                                 resolve_names = 1;
1085                         } else if (strcmp (optarg, "late") == 0) {
1086                                 resolve_names = 0;
1087                         } else if (strcmp (optarg, "never") == 0) {
1088                                 resolve_names = -1;
1089                         } else {
1090                                 fprintf(stderr, "resolve-names must be early, late or never\n");
1091                                 err(udev, "resolve-names must be early, late or never\n");
1092                                 goto exit;
1093                         }
1094                         break;
1095                 case 'h':
1096                         printf("Usage: udevd OPTIONS\n"
1097                                "  --daemon\n"
1098                                "  --debug\n"
1099                                "  --children-max=<maximum number of workers>\n"
1100                                "  --exec-delay=<seconds to wait before executing RUN=>\n"
1101                                "  --resolve-names=early|late|never\n"
1102                                "  --version\n"
1103                                "  --help\n"
1104                                "\n");
1105                         goto exit;
1106                 case 'V':
1107                         printf("%s\n", VERSION);
1108                         goto exit;
1109                 default:
1110                         goto exit;
1111                 }
1112         }
1113
1114         /*
1115          * read the kernel commandline, in case we need to get into debug mode
1116          *   udev.log-priority=<level>              syslog priority
1117          *   udev.children-max=<number of workers>  events are fully serialized if set to 1
1118          *
1119          */
1120         f = fopen("/proc/cmdline", "r");
1121         if (f != NULL) {
1122                 char cmdline[4096];
1123
1124                 if (fgets(cmdline, sizeof(cmdline), f) != NULL) {
1125                         char *pos;
1126
1127                         pos = strstr(cmdline, "udev.log-priority=");
1128                         if (pos != NULL) {
1129                                 pos += strlen("udev.log-priority=");
1130                                 udev_set_log_priority(udev, util_log_priority(pos));
1131                         }
1132
1133                         pos = strstr(cmdline, "udev.children-max=");
1134                         if (pos != NULL) {
1135                                 pos += strlen("udev.children-max=");
1136                                 children_max = strtoul(pos, NULL, 0);
1137                         }
1138
1139                         pos = strstr(cmdline, "udev.exec-delay=");
1140                         if (pos != NULL) {
1141                                 pos += strlen("udev.exec-delay=");
1142                                 exec_delay = strtoul(pos, NULL, 0);
1143                         }
1144                 }
1145                 fclose(f);
1146         }
1147
1148         if (getuid() != 0) {
1149                 fprintf(stderr, "root privileges required\n");
1150                 err(udev, "root privileges required\n");
1151                 goto exit;
1152         }
1153
1154         /* set umask before creating any file/directory */
1155         chdir("/");
1156         umask(022);
1157
1158         /* before opening new files, make sure std{in,out,err} fds are in a sane state */
1159         fd = open("/dev/null", O_RDWR);
1160         if (fd < 0) {
1161                 fprintf(stderr, "cannot open /dev/null\n");
1162                 err(udev, "cannot open /dev/null\n");
1163         }
1164         if (write(STDOUT_FILENO, 0, 0) < 0)
1165                 dup2(fd, STDOUT_FILENO);
1166         if (write(STDERR_FILENO, 0, 0) < 0)
1167                 dup2(fd, STDERR_FILENO);
1168
1169         udev_ctrl = udev_ctrl_new_from_socket(udev, UDEV_CTRL_SOCK_PATH);
1170         if (udev_ctrl == NULL) {
1171                 fprintf(stderr, "error initializing control socket");
1172                 err(udev, "error initializing udevd socket");
1173                 rc = 1;
1174                 goto exit;
1175         }
1176         if (udev_ctrl_enable_receiving(udev_ctrl) < 0) {
1177                 fprintf(stderr, "error binding control socket, seems udevd is already running\n");
1178                 err(udev, "error binding control socket, seems udevd is already running\n");
1179                 rc = 1;
1180                 goto exit;
1181         }
1182         pfd[FD_CONTROL].fd = udev_ctrl_get_fd(udev_ctrl);
1183
1184         monitor = udev_monitor_new_from_netlink(udev, "kernel");
1185         if (monitor == NULL || udev_monitor_enable_receiving(monitor) < 0) {
1186                 fprintf(stderr, "error initializing netlink socket\n");
1187                 err(udev, "error initializing netlink socket\n");
1188                 rc = 3;
1189                 goto exit;
1190         }
1191         udev_monitor_set_receive_buffer_size(monitor, 128*1024*1024);
1192         pfd[FD_NETLINK].fd = udev_monitor_get_fd(monitor);
1193
1194         pfd[FD_INOTIFY].fd = udev_watch_init(udev);
1195         if (pfd[FD_INOTIFY].fd < 0) {
1196                 fprintf(stderr, "error initializing inotify\n");
1197                 err(udev, "error initializing inotify\n");
1198                 rc = 4;
1199                 goto exit;
1200         }
1201
1202         if (udev_get_rules_path(udev) != NULL) {
1203                 inotify_add_watch(pfd[FD_INOTIFY].fd, udev_get_rules_path(udev),
1204                                   IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
1205         } else {
1206                 char filename[UTIL_PATH_SIZE];
1207                 struct stat statbuf;
1208
1209                 inotify_add_watch(pfd[FD_INOTIFY].fd, LIBEXECDIR "/rules.d",
1210                                   IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
1211                 inotify_add_watch(pfd[FD_INOTIFY].fd, SYSCONFDIR "/udev/rules.d",
1212                                   IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
1213
1214                 /* watch dynamic rules directory */
1215                 util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev), "/.udev/rules.d", NULL);
1216                 if (stat(filename, &statbuf) != 0) {
1217                         util_create_path(udev, filename);
1218                         udev_selinux_setfscreatecon(udev, filename, S_IFDIR|0755);
1219                         mkdir(filename, 0755);
1220                         udev_selinux_resetfscreatecon(udev);
1221                 }
1222                 inotify_add_watch(pfd[FD_INOTIFY].fd, filename,
1223                                   IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
1224         }
1225         udev_watch_restore(udev);
1226
1227         /* block and listen to all signals on signalfd */
1228         sigfillset(&mask);
1229         sigprocmask(SIG_SETMASK, &mask, &orig_sigmask);
1230         pfd[FD_SIGNAL].fd = signalfd(-1, &mask, 0);
1231         if (pfd[FD_SIGNAL].fd < 0) {
1232                 fprintf(stderr, "error getting signalfd\n");
1233                 err(udev, "error getting signalfd\n");
1234                 rc = 5;
1235                 goto exit;
1236         }
1237
1238         /* unnamed socket from workers to the main daemon */
1239         if (socketpair(AF_LOCAL, SOCK_DGRAM|SOCK_CLOEXEC, 0, worker_watch) < 0) {
1240                 fprintf(stderr, "error getting socketpair\n");
1241                 err(udev, "error getting socketpair\n");
1242                 rc = 6;
1243                 goto exit;
1244         }
1245         pfd[FD_WORKER].fd = worker_watch[READ_END];
1246
1247         rules = udev_rules_new(udev, resolve_names);
1248         if (rules == NULL) {
1249                 err(udev, "error reading rules\n");
1250                 goto exit;
1251         }
1252
1253         udev_queue_export = udev_queue_export_new(udev);
1254         if (udev_queue_export == NULL) {
1255                 err(udev, "error creating queue file\n");
1256                 goto exit;
1257         }
1258
1259         if (!debug) {
1260                 dup2(fd, STDIN_FILENO);
1261                 dup2(fd, STDOUT_FILENO);
1262                 dup2(fd, STDERR_FILENO);
1263         }
1264         if (fd > STDERR_FILENO)
1265                 close(fd);
1266
1267         if (daemonize) {
1268                 pid_t pid;
1269
1270                 pid = fork();
1271                 switch (pid) {
1272                 case 0:
1273                         break;
1274                 case -1:
1275                         err(udev, "fork of daemon failed: %m\n");
1276                         rc = 4;
1277                         goto exit;
1278                 default:
1279                         rc = 0;
1280                         goto exit;
1281                 }
1282         } else {
1283                 init_notify("READY=1");
1284         }
1285
1286         /* set scheduling priority for the main daemon process */
1287         setpriority(PRIO_PROCESS, 0, UDEVD_PRIORITY);
1288
1289         setsid();
1290
1291         f = fopen("/dev/kmsg", "w");
1292         if (f != NULL) {
1293                 fprintf(f, "<6>udev: starting version " VERSION "\n");
1294                 fclose(f);
1295         }
1296
1297         /* OOM_DISABLE == -17 */
1298         fd = open("/proc/self/oom_adj", O_RDWR);
1299         if (fd < 0) {
1300                 err(udev, "error disabling OOM: %m\n");
1301         } else {
1302                 write(fd, "-17", 3);
1303                 close(fd);
1304         }
1305
1306         if (children_max <= 0) {
1307                 int memsize = mem_size_mb();
1308
1309                 /* set value depending on the amount of RAM */
1310                 if (memsize > 0)
1311                         children_max = 128 + (memsize / 8);
1312                 else
1313                         children_max = 128;
1314         }
1315         info(udev, "set children_max to %u\n", children_max);
1316
1317         static_dev_create(udev);
1318         static_dev_create_from_modules(udev);
1319         udev_rules_apply_static_dev_perms(rules);
1320
1321         udev_list_init(&event_list);
1322         udev_list_init(&worker_list);
1323
1324         while (!udev_exit) {
1325                 int fdcount;
1326                 int timeout;
1327
1328                 /* set timeout to kill idle workers */
1329                 if (udev_list_is_empty(&event_list) && children > 2)
1330                         timeout = 3 * 1000;
1331                 else
1332                         timeout = -1;
1333                 /* wait for events */
1334                 fdcount = poll(pfd, ARRAY_SIZE(pfd), timeout);
1335                 if (fdcount < 0)
1336                         continue;
1337
1338                 /* timeout - kill idle workers */
1339                 if (fdcount == 0)
1340                         worker_kill(udev, 2);
1341
1342                 /* event has finished */
1343                 if (pfd[FD_WORKER].revents & POLLIN)
1344                         worker_returned();
1345
1346                 /* get kernel uevent */
1347                 if (pfd[FD_NETLINK].revents & POLLIN) {
1348                         struct udev_device *dev;
1349
1350                         dev = udev_monitor_receive_device(monitor);
1351                         if (dev != NULL)
1352                                 event_queue_insert(dev);
1353                         else
1354                                 udev_device_unref(dev);
1355                 }
1356
1357                 /* start new events */
1358                 if (!udev_list_is_empty(&event_list) && !stop_exec_queue)
1359                         events_start(udev);
1360
1361                 /* get signal */
1362                 if (pfd[FD_SIGNAL].revents & POLLIN) {
1363                         struct signalfd_siginfo fdsi;
1364                         ssize_t size;
1365
1366                         size = read(pfd[FD_SIGNAL].fd, &fdsi, sizeof(struct signalfd_siginfo));
1367                         if (size == sizeof(struct signalfd_siginfo))
1368                                 handle_signal(udev, fdsi.ssi_signo);
1369                 }
1370
1371                 /* device node and rules directory inotify watch */
1372                 if (pfd[FD_INOTIFY].revents & POLLIN)
1373                         handle_inotify(udev);
1374
1375                 /*
1376                  * get control message
1377                  *
1378                  * This needs to be after the inotify handling, to make sure,
1379                  * that the settle signal is send back after the possibly generated
1380                  * "change" events by the inotify device node watch.
1381                  */
1382                 if (pfd[FD_CONTROL].revents & POLLIN)
1383                         handle_ctrl_msg(udev_ctrl);
1384
1385                 /* rules changed, set by inotify or a HUP signal */
1386                 if (reload_config) {
1387                         struct udev_rules *rules_new;
1388
1389                         worker_kill(udev, 0);
1390                         rules_new = udev_rules_new(udev, resolve_names);
1391                         if (rules_new != NULL) {
1392                                 udev_rules_unref(rules);
1393                                 rules = rules_new;
1394                         }
1395                         reload_config = 0;
1396                 }
1397         }
1398
1399         udev_queue_export_cleanup(udev_queue_export);
1400         rc = 0;
1401 exit:
1402         udev_queue_export_unref(udev_queue_export);
1403         udev_rules_unref(rules);
1404         udev_ctrl_unref(udev_ctrl);
1405         if (pfd[FD_SIGNAL].fd >= 0)
1406                 close(pfd[FD_SIGNAL].fd);
1407         if (worker_watch[READ_END] >= 0)
1408                 close(worker_watch[READ_END]);
1409         if (worker_watch[WRITE_END] >= 0)
1410                 close(worker_watch[WRITE_END]);
1411         udev_monitor_unref(monitor);
1412         udev_selinux_exit(udev);
1413         udev_unref(udev);
1414         udev_log_close();
1415         return rc;
1416 }