src/udev/udevd.c

   1 /*
   2  * Copyright (C) 2004-2012 Kay Sievers <kay@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/file.h>
  35 #include <sys/time.h>
  36 #include <sys/prctl.h>
  37 #include <sys/socket.h>
  38 #include <sys/un.h>
  39 #include <sys/signalfd.h>
  40 #include <sys/epoll.h>
  41 #include <sys/poll.h>
  42 #include <sys/wait.h>
  43 #include <sys/stat.h>
  44 #include <sys/ioctl.h>
  45 #include <sys/inotify.h>
  46 #include <sys/utsname.h>
  47
  48 #include "udev.h"
  49 #include "sd-daemon.h"
  50 #include "cgroup-util.h"
  51 #include "dev-setup.h"
  52 #include "fileio.h"
  53
  54 static bool debug;
  55
  56 void udev_main_log(struct udev *udev, int priority,
  57                    const char *file, int line, const char *fn,
  58                    const char *format, va_list args)
  59 {
  60         log_metav(priority, file, line, fn, format, args);
  61 }
  62
  63 static struct udev_rules *rules;
  64 static struct udev_ctrl *udev_ctrl;
  65 static struct udev_monitor *monitor;
  66 static int worker_watch[2] = { -1, -1 };
  67 static int fd_signal = -1;
  68 static int fd_ep = -1;
  69 static int fd_inotify = -1;
  70 static bool stop_exec_queue;
  71 static bool reload;
  72 static int children;
  73 static int children_max;
  74 static int exec_delay;
  75 static sigset_t sigmask_orig;
  76 static UDEV_LIST(event_list);
  77 static UDEV_LIST(worker_list);
  78 static char *udev_cgroup;
  79 static bool udev_exit;
  80
  81 enum event_state {
  82         EVENT_UNDEF,
  83         EVENT_QUEUED,
  84         EVENT_RUNNING,
  85 };
  86
  87 struct event {
  88         struct udev_list_node node;
  89         struct udev *udev;
  90         struct udev_device *dev;
  91         enum event_state state;
  92         int exitcode;
  93         unsigned long long int delaying_seqnum;
  94         unsigned long long int seqnum;
  95         const char *devpath;
  96         size_t devpath_len;
  97         const char *devpath_old;
  98         dev_t devnum;
  99         int ifindex;
 100         bool is_block;
 101 #ifdef HAVE_FIRMWARE
 102         bool nodelay;
 103 #endif
 104 };
 105
 106 static inline struct event *node_to_event(struct udev_list_node *node)
 107 {
 108         return container_of(node, struct event, node);
 109 }
 110
 111 static void event_queue_cleanup(struct udev *udev, enum event_state type);
 112
 113 enum worker_state {
 114         WORKER_UNDEF,
 115         WORKER_RUNNING,
 116         WORKER_IDLE,
 117         WORKER_KILLED,
 118 };
 119
 120 struct worker {
 121         struct udev_list_node node;
 122         struct udev *udev;
 123         int refcount;
 124         pid_t pid;
 125         struct udev_monitor *monitor;
 126         enum worker_state state;
 127         struct event *event;
 128         usec_t event_start_usec;
 129 };
 130
 131 /* passed from worker to main process */
 132 struct worker_message {
 133         pid_t pid;
 134         int exitcode;
 135 };
 136
 137 static inline struct worker *node_to_worker(struct udev_list_node *node)
 138 {
 139         return container_of(node, struct worker, node);
 140 }
 141
 142 static void event_queue_delete(struct event *event)
 143 {
 144         udev_list_node_remove(&event->node);
 145         udev_device_unref(event->dev);
 146         free(event);
 147 }
 148
 149 static struct worker *worker_ref(struct worker *worker)
 150 {
 151         worker->refcount++;
 152         return worker;
 153 }
 154
 155 static void worker_cleanup(struct worker *worker)
 156 {
 157         udev_list_node_remove(&worker->node);
 158         udev_monitor_unref(worker->monitor);
 159         children--;
 160         free(worker);
 161 }
 162
 163 static void worker_unref(struct worker *worker)
 164 {
 165         worker->refcount--;
 166         if (worker->refcount > 0)
 167                 return;
 168         log_debug("worker [%u] cleaned up", worker->pid);
 169         worker_cleanup(worker);
 170 }
 171
 172 static void worker_list_cleanup(struct udev *udev)
 173 {
 174         struct udev_list_node *loop, *tmp;
 175
 176         udev_list_node_foreach_safe(loop, tmp, &worker_list) {
 177                 struct worker *worker = node_to_worker(loop);
 178
 179                 worker_cleanup(worker);
 180         }
 181 }
 182
 183 static void worker_new(struct event *event)
 184 {
 185         struct udev *udev = event->udev;
 186         struct worker *worker;
 187         struct udev_monitor *worker_monitor;
 188         pid_t pid;
 189
 190         /* listen for new events */
 191         worker_monitor = udev_monitor_new_from_netlink(udev, NULL);
 192         if (worker_monitor == NULL)
 193                 return;
 194         /* allow the main daemon netlink address to send devices to the worker */
 195         udev_monitor_allow_unicast_sender(worker_monitor, monitor);
 196         udev_monitor_enable_receiving(worker_monitor);
 197
 198         worker = new0(struct worker, 1);
 199         if (worker == NULL) {
 200                 udev_monitor_unref(worker_monitor);
 201                 return;
 202         }
 203         /* worker + event reference */
 204         worker->refcount = 2;
 205         worker->udev = udev;
 206
 207         pid = fork();
 208         switch (pid) {
 209         case 0: {
 210                 struct udev_device *dev = NULL;
 211                 int fd_monitor;
 212                 struct epoll_event ep_signal, ep_monitor;
 213                 sigset_t mask;
 214                 int rc = EXIT_SUCCESS;
 215
 216                 /* take initial device from queue */
 217                 dev = event->dev;
 218                 event->dev = NULL;
 219
 220                 free(worker);
 221                 worker_list_cleanup(udev);
 222                 event_queue_cleanup(udev, EVENT_UNDEF);
 223                 udev_monitor_unref(monitor);
 224                 udev_ctrl_unref(udev_ctrl);
 225                 close(fd_signal);
 226                 close(fd_ep);
 227                 close(worker_watch[READ_END]);
 228
 229                 sigfillset(&mask);
 230                 fd_signal = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC);
 231                 if (fd_signal < 0) {
 232                         log_error("error creating signalfd %m");
 233                         rc = 2;
 234                         goto out;
 235                 }
 236
 237                 fd_ep = epoll_create1(EPOLL_CLOEXEC);
 238                 if (fd_ep < 0) {
 239                         log_error("error creating epoll fd: %m");
 240                         rc = 3;
 241                         goto out;
 242                 }
 243
 244                 memzero(&ep_signal, sizeof(struct epoll_event));
 245                 ep_signal.events = EPOLLIN;
 246                 ep_signal.data.fd = fd_signal;
 247
 248                 fd_monitor = udev_monitor_get_fd(worker_monitor);
 249                 memzero(&ep_monitor, sizeof(struct epoll_event));
 250                 ep_monitor.events = EPOLLIN;
 251                 ep_monitor.data.fd = fd_monitor;
 252
 253                 if (epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_signal, &ep_signal) < 0 ||
 254                     epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_monitor, &ep_monitor) < 0) {
 255                         log_error("fail to add fds to epoll: %m");
 256                         rc = 4;
 257                         goto out;
 258                 }
 259
 260                 /* request TERM signal if parent exits */
 261                 prctl(PR_SET_PDEATHSIG, SIGTERM);
 262
 263                 /* reset OOM score, we only protect the main daemon */
 264                 write_string_file("/proc/self/oom_score_adj", "0");
 265
 266                 for (;;) {
 267                         struct udev_event *udev_event;
 268                         struct worker_message msg;
 269                         int fd_lock = -1;
 270                         int err;
 271
 272                         log_debug("seq %llu running", udev_device_get_seqnum(dev));
 273                         udev_event = udev_event_new(dev);
 274                         if (udev_event == NULL) {
 275                                 rc = 5;
 276                                 goto out;
 277                         }
 278
 279                         /* needed for SIGCHLD/SIGTERM in spawn() */
 280                         udev_event->fd_signal = fd_signal;
 281
 282                         if (exec_delay > 0)
 283                                 udev_event->exec_delay = exec_delay;
 284
 285                         /*
 286                          * Take a "read lock" on the device node; this establishes
 287                          * a concept of device "ownership" to serialize device
 288                          * access. External processes holding a "write lock" will
 289                          * cause udev to skip the event handling; in the case udev
 290                          * acquired the lock, the external process will block until
 291                          * udev has finished its event handling.
 292                          */
 293                         if (streq_ptr("block", udev_device_get_subsystem(dev))) {
 294                                 struct udev_device *d = dev;
 295
 296                                 if (streq_ptr("partition", udev_device_get_devtype(d)))
 297                                         d = udev_device_get_parent(d);
 298
 299                                 if (d) {
 300                                         fd_lock = open(udev_device_get_devnode(d), O_RDONLY|O_CLOEXEC|O_NOFOLLOW|O_NONBLOCK);
 301                                         if (fd_lock >= 0 && flock(fd_lock, LOCK_SH|LOCK_NB) < 0) {
 302                                                 log_debug("Unable to flock(%s), skipping event handling: %m", udev_device_get_devnode(d));
 303                                                 err = -EWOULDBLOCK;
 304                                                 goto skip;
 305                                         }
 306                                 }
 307                         }
 308
 309                         /* apply rules, create node, symlinks */
 310                         udev_event_execute_rules(udev_event, rules, &sigmask_orig);
 311
 312                         udev_event_execute_run(udev_event, &sigmask_orig);
 313
 314                         /* apply/restore inotify watch */
 315                         if (err == 0 && udev_event->inotify_watch) {
 316                                 udev_watch_begin(udev, dev);
 317                                 udev_device_update_db(dev);
 318                         }
 319
 320                         if (fd_lock >= 0)
 321                                 close(fd_lock);
 322
 323                         /* send processed event back to libudev listeners */
 324                         udev_monitor_send_device(worker_monitor, NULL, dev);
 325
 326 skip:
 327                         /* send udevd the result of the event execution */
 328                         memzero(&msg, sizeof(struct worker_message));
 329                         msg.exitcode = err;
 330                         msg.pid = getpid();
 331                         send(worker_watch[WRITE_END], &msg, sizeof(struct worker_message), 0);
 332
 333                         log_debug("seq %llu processed with %i", udev_device_get_seqnum(dev), err);
 334
 335                         udev_device_unref(dev);
 336                         dev = NULL;
 337
 338                         if (udev_event->sigterm) {
 339                                 udev_event_unref(udev_event);
 340                                 goto out;
 341                         }
 342
 343                         udev_event_unref(udev_event);
 344
 345                         /* wait for more device messages from main udevd, or term signal */
 346                         while (dev == NULL) {
 347                                 struct epoll_event ev[4];
 348                                 int fdcount;
 349                                 int i;
 350
 351                                 fdcount = epoll_wait(fd_ep, ev, ELEMENTSOF(ev), -1);
 352                                 if (fdcount < 0) {
 353                                         if (errno == EINTR)
 354                                                 continue;
 355                                         log_error("failed to poll: %m");
 356                                         goto out;
 357                                 }
 358
 359                                 for (i = 0; i < fdcount; i++) {
 360                                         if (ev[i].data.fd == fd_monitor && ev[i].events & EPOLLIN) {
 361                                                 dev = udev_monitor_receive_device(worker_monitor);
 362                                                 break;
 363                                         } else if (ev[i].data.fd == fd_signal && ev[i].events & EPOLLIN) {
 364                                                 struct signalfd_siginfo fdsi;
 365                                                 ssize_t size;
 366
 367                                                 size = read(fd_signal, &fdsi, sizeof(struct signalfd_siginfo));
 368                                                 if (size != sizeof(struct signalfd_siginfo))
 369                                                         continue;
 370                                                 switch (fdsi.ssi_signo) {
 371                                                 case SIGTERM:
 372                                                         goto out;
 373                                                 }
 374                                         }
 375                                 }
 376                         }
 377                 }
 378 out:
 379                 udev_device_unref(dev);
 380                 if (fd_signal >= 0)
 381                         close(fd_signal);
 382                 if (fd_ep >= 0)
 383                         close(fd_ep);
 384                 close(fd_inotify);
 385                 close(worker_watch[WRITE_END]);
 386                 udev_rules_unref(rules);
 387                 udev_builtin_exit(udev);
 388                 udev_monitor_unref(worker_monitor);
 389                 udev_unref(udev);
 390                 log_close();
 391                 exit(rc);
 392         }
 393         case -1:
 394                 udev_monitor_unref(worker_monitor);
 395                 event->state = EVENT_QUEUED;
 396                 free(worker);
 397                 log_error("fork of child failed: %m");
 398                 break;
 399         default:
 400                 /* close monitor, but keep address around */
 401                 udev_monitor_disconnect(worker_monitor);
 402                 worker->monitor = worker_monitor;
 403                 worker->pid = pid;
 404                 worker->state = WORKER_RUNNING;
 405                 worker->event_start_usec = now(CLOCK_MONOTONIC);
 406                 worker->event = event;
 407                 event->state = EVENT_RUNNING;
 408                 udev_list_node_append(&worker->node, &worker_list);
 409                 children++;
 410                 log_debug("seq %llu forked new worker [%u]", udev_device_get_seqnum(event->dev), pid);
 411                 break;
 412         }
 413 }
 414
 415 static void event_run(struct event *event)
 416 {
 417         struct udev_list_node *loop;
 418
 419         udev_list_node_foreach(loop, &worker_list) {
 420                 struct worker *worker = node_to_worker(loop);
 421                 ssize_t count;
 422
 423                 if (worker->state != WORKER_IDLE)
 424                         continue;
 425
 426                 count = udev_monitor_send_device(monitor, worker->monitor, event->dev);
 427                 if (count < 0) {
 428                         log_error("worker [%u] did not accept message %zi (%m), kill it", worker->pid, count);
 429                         kill(worker->pid, SIGKILL);
 430                         worker->state = WORKER_KILLED;
 431                         continue;
 432                 }
 433                 worker_ref(worker);
 434                 worker->event = event;
 435                 worker->state = WORKER_RUNNING;
 436                 worker->event_start_usec = now(CLOCK_MONOTONIC);
 437                 event->state = EVENT_RUNNING;
 438                 return;
 439         }
 440
 441         if (children >= children_max) {
 442                 if (children_max > 1)
 443                         log_debug("maximum number (%i) of children reached", children);
 444                 return;
 445         }
 446
 447         /* start new worker and pass initial device */
 448         worker_new(event);
 449 }
 450
 451 static int event_queue_insert(struct udev_device *dev)
 452 {
 453         struct event *event;
 454
 455         event = new0(struct event, 1);
 456         if (event == NULL)
 457                 return -1;
 458
 459         event->udev = udev_device_get_udev(dev);
 460         event->dev = dev;
 461         event->seqnum = udev_device_get_seqnum(dev);
 462         event->devpath = udev_device_get_devpath(dev);
 463         event->devpath_len = strlen(event->devpath);
 464         event->devpath_old = udev_device_get_devpath_old(dev);
 465         event->devnum = udev_device_get_devnum(dev);
 466         event->is_block = streq("block", udev_device_get_subsystem(dev));
 467         event->ifindex = udev_device_get_ifindex(dev);
 468 #ifdef HAVE_FIRMWARE
 469         if (streq(udev_device_get_subsystem(dev), "firmware"))
 470                 event->nodelay = true;
 471 #endif
 472
 473         log_debug("seq %llu queued, '%s' '%s'", udev_device_get_seqnum(dev),
 474              udev_device_get_action(dev), udev_device_get_subsystem(dev));
 475
 476         event->state = EVENT_QUEUED;
 477         udev_list_node_append(&event->node, &event_list);
 478         return 0;
 479 }
 480
 481 static void worker_kill(struct udev *udev)
 482 {
 483         struct udev_list_node *loop;
 484
 485         udev_list_node_foreach(loop, &worker_list) {
 486                 struct worker *worker = node_to_worker(loop);
 487
 488                 if (worker->state == WORKER_KILLED)
 489                         continue;
 490
 491                 worker->state = WORKER_KILLED;
 492                 kill(worker->pid, SIGTERM);
 493         }
 494 }
 495
 496 /* lookup event for identical, parent, child device */
 497 static bool is_devpath_busy(struct event *event)
 498 {
 499         struct udev_list_node *loop;
 500         size_t common;
 501
 502         /* check if queue contains events we depend on */
 503         udev_list_node_foreach(loop, &event_list) {
 504                 struct event *loop_event = node_to_event(loop);
 505
 506                 /* we already found a later event, earlier can not block us, no need to check again */
 507                 if (loop_event->seqnum < event->delaying_seqnum)
 508                         continue;
 509
 510                 /* event we checked earlier still exists, no need to check again */
 511                 if (loop_event->seqnum == event->delaying_seqnum)
 512                         return true;
 513
 514                 /* found ourself, no later event can block us */
 515                 if (loop_event->seqnum >= event->seqnum)
 516                         break;
 517
 518                 /* check major/minor */
 519                 if (major(event->devnum) != 0 && event->devnum == loop_event->devnum && event->is_block == loop_event->is_block)
 520                         return true;
 521
 522                 /* check network device ifindex */
 523                 if (event->ifindex != 0 && event->ifindex == loop_event->ifindex)
 524                         return true;
 525
 526                 /* check our old name */
 527                 if (event->devpath_old != NULL && streq(loop_event->devpath, event->devpath_old)) {
 528                         event->delaying_seqnum = loop_event->seqnum;
 529                         return true;
 530                 }
 531
 532                 /* compare devpath */
 533                 common = MIN(loop_event->devpath_len, event->devpath_len);
 534
 535                 /* one devpath is contained in the other? */
 536                 if (memcmp(loop_event->devpath, event->devpath, common) != 0)
 537                         continue;
 538
 539                 /* identical device event found */
 540                 if (loop_event->devpath_len == event->devpath_len) {
 541                         /* devices names might have changed/swapped in the meantime */
 542                         if (major(event->devnum) != 0 && (event->devnum != loop_event->devnum || event->is_block != loop_event->is_block))
 543                                 continue;
 544                         if (event->ifindex != 0 && event->ifindex != loop_event->ifindex)
 545                                 continue;
 546                         event->delaying_seqnum = loop_event->seqnum;
 547                         return true;
 548                 }
 549
 550 #ifdef HAVE_FIRMWARE
 551                 /* allow to bypass the dependency tracking */
 552                 if (event->nodelay)
 553                         continue;
 554 #endif
 555
 556                 /* parent device event found */
 557                 if (event->devpath[common] == '/') {
 558                         event->delaying_seqnum = loop_event->seqnum;
 559                         return true;
 560                 }
 561
 562                 /* child device event found */
 563                 if (loop_event->devpath[common] == '/') {
 564                         event->delaying_seqnum = loop_event->seqnum;
 565                         return true;
 566                 }
 567
 568                 /* no matching device */
 569                 continue;
 570         }
 571
 572         return false;
 573 }
 574
 575 static void event_queue_start(struct udev *udev)
 576 {
 577         struct udev_list_node *loop;
 578
 579         udev_list_node_foreach(loop, &event_list) {
 580                 struct event *event = node_to_event(loop);
 581
 582                 if (event->state != EVENT_QUEUED)
 583                         continue;
 584
 585                 /* do not start event if parent or child event is still running */
 586                 if (is_devpath_busy(event))
 587                         continue;
 588
 589                 event_run(event);
 590         }
 591 }
 592
 593 static void event_queue_cleanup(struct udev *udev, enum event_state match_type)
 594 {
 595         struct udev_list_node *loop, *tmp;
 596
 597         udev_list_node_foreach_safe(loop, tmp, &event_list) {
 598                 struct event *event = node_to_event(loop);
 599
 600                 if (match_type != EVENT_UNDEF && match_type != event->state)
 601                         continue;
 602
 603                 event_queue_delete(event);
 604         }
 605 }
 606
 607 static void worker_returned(int fd_worker)
 608 {
 609         for (;;) {
 610                 struct worker_message msg;
 611                 ssize_t size;
 612                 struct udev_list_node *loop;
 613
 614                 size = recv(fd_worker, &msg, sizeof(struct worker_message), MSG_DONTWAIT);
 615                 if (size != sizeof(struct worker_message))
 616                         break;
 617
 618                 /* lookup worker who sent the signal */
 619                 udev_list_node_foreach(loop, &worker_list) {
 620                         struct worker *worker = node_to_worker(loop);
 621
 622                         if (worker->pid != msg.pid)
 623                                 continue;
 624
 625                         /* worker returned */
 626                         if (worker->event) {
 627                                 worker->event->exitcode = msg.exitcode;
 628                                 event_queue_delete(worker->event);
 629                                 worker->event = NULL;
 630                         }
 631                         if (worker->state != WORKER_KILLED)
 632                                 worker->state = WORKER_IDLE;
 633                         worker_unref(worker);
 634                         break;
 635                 }
 636         }
 637 }
 638
 639 /* receive the udevd message from userspace */
 640 static struct udev_ctrl_connection *handle_ctrl_msg(struct udev_ctrl *uctrl)
 641 {
 642         struct udev *udev = udev_ctrl_get_udev(uctrl);
 643         struct udev_ctrl_connection *ctrl_conn;
 644         struct udev_ctrl_msg *ctrl_msg = NULL;
 645         const char *str;
 646         int i;
 647
 648         ctrl_conn = udev_ctrl_get_connection(uctrl);
 649         if (ctrl_conn == NULL)
 650                 goto out;
 651
 652         ctrl_msg = udev_ctrl_receive_msg(ctrl_conn);
 653         if (ctrl_msg == NULL)
 654                 goto out;
 655
 656         i = udev_ctrl_get_set_log_level(ctrl_msg);
 657         if (i >= 0) {
 658                 log_debug("udevd message (SET_LOG_LEVEL) received, log_priority=%i", i);
 659                 log_set_max_level(i);
 660                 udev_set_log_priority(udev, i);
 661                 worker_kill(udev);
 662         }
 663
 664         if (udev_ctrl_get_stop_exec_queue(ctrl_msg) > 0) {
 665                 log_debug("udevd message (STOP_EXEC_QUEUE) received");
 666                 stop_exec_queue = true;
 667         }
 668
 669         if (udev_ctrl_get_start_exec_queue(ctrl_msg) > 0) {
 670                 log_debug("udevd message (START_EXEC_QUEUE) received");
 671                 stop_exec_queue = false;
 672         }
 673
 674         if (udev_ctrl_get_reload(ctrl_msg) > 0) {
 675                 log_debug("udevd message (RELOAD) received");
 676                 reload = true;
 677         }
 678
 679         str = udev_ctrl_get_set_env(ctrl_msg);
 680         if (str != NULL) {
 681                 char *key;
 682
 683                 key = strdup(str);
 684                 if (key != NULL) {
 685                         char *val;
 686
 687                         val = strchr(key, '=');
 688                         if (val != NULL) {
 689                                 val[0] = '\0';
 690                                 val = &val[1];
 691                                 if (val[0] == '\0') {
 692                                         log_debug("udevd message (ENV) received, unset '%s'", key);
 693                                         udev_add_property(udev, key, NULL);
 694                                 } else {
 695                                         log_debug("udevd message (ENV) received, set '%s=%s'", key, val);
 696                                         udev_add_property(udev, key, val);
 697                                 }
 698                         } else {
 699                                 log_error("wrong key format '%s'", key);
 700                         }
 701                         free(key);
 702                 }
 703                 worker_kill(udev);
 704         }
 705
 706         i = udev_ctrl_get_set_children_max(ctrl_msg);
 707         if (i >= 0) {
 708                 log_debug("udevd message (SET_MAX_CHILDREN) received, children_max=%i", i);
 709                 children_max = i;
 710         }
 711
 712         if (udev_ctrl_get_ping(ctrl_msg) > 0)
 713                 log_debug("udevd message (SYNC) received");
 714
 715         if (udev_ctrl_get_exit(ctrl_msg) > 0) {
 716                 log_debug("udevd message (EXIT) received");
 717                 udev_exit = true;
 718                 /* keep reference to block the client until we exit */
 719                 udev_ctrl_connection_ref(ctrl_conn);
 720         }
 721 out:
 722         udev_ctrl_msg_unref(ctrl_msg);
 723         return udev_ctrl_connection_unref(ctrl_conn);
 724 }
 725
 726 /* read inotify messages */
 727 static int handle_inotify(struct udev *udev)
 728 {
 729         int nbytes, pos;
 730         char *buf;
 731         struct inotify_event *ev;
 732
 733         if ((ioctl(fd_inotify, FIONREAD, &nbytes) < 0) || (nbytes <= 0))
 734                 return 0;
 735
 736         buf = malloc(nbytes);
 737         if (buf == NULL) {
 738                 log_error("error getting buffer for inotify");
 739                 return -1;
 740         }
 741
 742         nbytes = read(fd_inotify, buf, nbytes);
 743
 744         for (pos = 0; pos < nbytes; pos += sizeof(struct inotify_event) + ev->len) {
 745                 struct udev_device *dev;
 746
 747                 ev = (struct inotify_event *)(buf + pos);
 748                 dev = udev_watch_lookup(udev, ev->wd);
 749                 if (dev != NULL) {
 750                         log_debug("inotify event: %x for %s", ev->mask, udev_device_get_devnode(dev));
 751                         if (ev->mask & IN_CLOSE_WRITE) {
 752                                 char filename[UTIL_PATH_SIZE];
 753                                 int fd;
 754
 755                                 log_debug("device %s closed, synthesising 'change'", udev_device_get_devnode(dev));
 756                                 strscpyl(filename, sizeof(filename), udev_device_get_syspath(dev), "/uevent", NULL);
 757                                 fd = open(filename, O_WRONLY|O_CLOEXEC);
 758                                 if (fd >= 0) {
 759                                         if (write(fd, "change", 6) < 0)
 760                                                 log_debug("error writing uevent: %m");
 761                                         close(fd);
 762                                 }
 763                         }
 764                         if (ev->mask & IN_IGNORED)
 765                                 udev_watch_end(udev, dev);
 766
 767                         udev_device_unref(dev);
 768                 }
 769
 770         }
 771
 772         free(buf);
 773         return 0;
 774 }
 775
 776 static void handle_signal(struct udev *udev, int signo)
 777 {
 778         switch (signo) {
 779         case SIGINT:
 780         case SIGTERM:
 781                 udev_exit = true;
 782                 break;
 783         case SIGCHLD:
 784                 for (;;) {
 785                         pid_t pid;
 786                         int status;
 787                         struct udev_list_node *loop, *tmp;
 788
 789                         pid = waitpid(-1, &status, WNOHANG);
 790                         if (pid <= 0)
 791                                 break;
 792
 793                         udev_list_node_foreach_safe(loop, tmp, &worker_list) {
 794                                 struct worker *worker = node_to_worker(loop);
 795
 796                                 if (worker->pid != pid)
 797                                         continue;
 798                                 log_debug("worker [%u] exit", pid);
 799
 800                                 if (WIFEXITED(status)) {
 801                                         if (WEXITSTATUS(status) != 0)
 802                                                 log_error("worker [%u] exit with return code %i",
 803                                                           pid, WEXITSTATUS(status));
 804                                 } else if (WIFSIGNALED(status)) {
 805                                         log_error("worker [%u] terminated by signal %i (%s)",
 806                                                   pid, WTERMSIG(status), strsignal(WTERMSIG(status)));
 807                                 } else if (WIFSTOPPED(status)) {
 808                                         log_error("worker [%u] stopped", pid);
 809                                 } else if (WIFCONTINUED(status)) {
 810                                         log_error("worker [%u] continued", pid);
 811                                 } else {
 812                                         log_error("worker [%u] exit with status 0x%04x", pid, status);
 813                                 }
 814
 815                                 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
 816                                         if (worker->event) {
 817                                                 log_error("worker [%u] failed while handling '%s'",
 818                                                           pid, worker->event->devpath);
 819                                                 worker->event->exitcode = -32;
 820                                                 event_queue_delete(worker->event);
 821
 822                                                 /* drop reference taken for state 'running' */
 823                                                 worker_unref(worker);
 824                                         }
 825                                 }
 826                                 worker_unref(worker);
 827                                 break;
 828                         }
 829                 }
 830                 break;
 831         case SIGHUP:
 832                 reload = true;
 833                 break;
 834         }
 835 }
 836
 837 static int systemd_fds(struct udev *udev, int *rctrl, int *rnetlink)
 838 {
 839         int ctrl = -1, netlink = -1;
 840         int fd, n;
 841
 842         n = sd_listen_fds(true);
 843         if (n <= 0)
 844                 return -1;
 845
 846         for (fd = SD_LISTEN_FDS_START; fd < n + SD_LISTEN_FDS_START; fd++) {
 847                 if (sd_is_socket(fd, AF_LOCAL, SOCK_SEQPACKET, -1)) {
 848                         if (ctrl >= 0)
 849                                 return -1;
 850                         ctrl = fd;
 851                         continue;
 852                 }
 853
 854                 if (sd_is_socket(fd, AF_NETLINK, SOCK_RAW, -1)) {
 855                         if (netlink >= 0)
 856                                 return -1;
 857                         netlink = fd;
 858                         continue;
 859                 }
 860
 861                 return -1;
 862         }
 863
 864         if (ctrl < 0 || netlink < 0)
 865                 return -1;
 866
 867         log_debug("ctrl=%i netlink=%i", ctrl, netlink);
 868         *rctrl = ctrl;
 869         *rnetlink = netlink;
 870         return 0;
 871 }
 872
 873 /*
 874  * read the kernel commandline, in case we need to get into debug mode
 875  *   udev.log-priority=<level>              syslog priority
 876  *   udev.children-max=<number of workers>  events are fully serialized if set to 1
 877  *   udev.exec-delay=<number of seconds>    delay execution of every executed program
 878  */
 879 static void kernel_cmdline_options(struct udev *udev)
 880 {
 881         _cleanup_free_ char *line = NULL;
 882         char *w, *state;
 883         size_t l;
 884         int r;
 885
 886         r = proc_cmdline(&line);
 887         if (r < 0)
 888                 log_warning("Failed to read /proc/cmdline, ignoring: %s", strerror(-r));
 889         if (r <= 0)
 890                 return;
 891
 892         FOREACH_WORD_QUOTED(w, l, line, state) {
 893                 char *s, *opt;
 894
 895                 s = strndup(w, l);
 896                 if (!s)
 897                         break;
 898
 899                 /* accept the same options for the initrd, prefixed with "rd." */
 900                 if (in_initrd() && startswith(s, "rd."))
 901                         opt = s + 3;
 902                 else
 903                         opt = s;
 904
 905                 if (startswith(opt, "udev.log-priority=")) {
 906                         int prio;
 907
 908                         prio = util_log_priority(opt + 18);
 909                         log_set_max_level(prio);
 910                         udev_set_log_priority(udev, prio);
 911                 } else if (startswith(opt, "udev.children-max=")) {
 912                         children_max = strtoul(opt + 18, NULL, 0);
 913                 } else if (startswith(opt, "udev.exec-delay=")) {
 914                         exec_delay = strtoul(opt + 16, NULL, 0);
 915                 }
 916
 917                 free(s);
 918         }
 919 }
 920
 921 int main(int argc, char *argv[])
 922 {
 923         struct udev *udev;
 924         sigset_t mask;
 925         int daemonize = false;
 926         int resolve_names = 1;
 927         static const struct option options[] = {
 928                 { "daemon", no_argument, NULL, 'd' },
 929                 { "debug", no_argument, NULL, 'D' },
 930                 { "children-max", required_argument, NULL, 'c' },
 931                 { "exec-delay", required_argument, NULL, 'e' },
 932                 { "resolve-names", required_argument, NULL, 'N' },
 933                 { "help", no_argument, NULL, 'h' },
 934                 { "version", no_argument, NULL, 'V' },
 935                 {}
 936         };
 937         int fd_ctrl = -1;
 938         int fd_netlink = -1;
 939         int fd_worker = -1;
 940         struct epoll_event ep_ctrl, ep_inotify, ep_signal, ep_netlink, ep_worker;
 941         struct udev_ctrl_connection *ctrl_conn = NULL;
 942         int rc = 1;
 943
 944         udev = udev_new();
 945         if (udev == NULL)
 946                 goto exit;
 947
 948         log_set_target(LOG_TARGET_AUTO);
 949         log_parse_environment();
 950         log_open();
 951
 952         udev_set_log_fn(udev, udev_main_log);
 953         log_set_max_level(udev_get_log_priority(udev));
 954
 955         log_debug("version %s", VERSION);
 956         label_init("/dev");
 957
 958         for (;;) {
 959                 int option;
 960
 961                 option = getopt_long(argc, argv, "c:de:DtN:hV", options, NULL);
 962                 if (option == -1)
 963                         break;
 964
 965                 switch (option) {
 966                 case 'd':
 967                         daemonize = true;
 968                         break;
 969                 case 'c':
 970                         children_max = strtoul(optarg, NULL, 0);
 971                         break;
 972                 case 'e':
 973                         exec_delay = strtoul(optarg, NULL, 0);
 974                         break;
 975                 case 'D':
 976                         debug = true;
 977                         log_set_max_level(LOG_DEBUG);
 978                         udev_set_log_priority(udev, LOG_DEBUG);
 979                         break;
 980                 case 'N':
 981                         if (streq(optarg, "early")) {
 982                                 resolve_names = 1;
 983                         } else if (streq(optarg, "late")) {
 984                                 resolve_names = 0;
 985                         } else if (streq(optarg, "never")) {
 986                                 resolve_names = -1;
 987                         } else {
 988                                 fprintf(stderr, "resolve-names must be early, late or never\n");
 989                                 log_error("resolve-names must be early, late or never");
 990                                 goto exit;
 991                         }
 992                         break;
 993                 case 'h':
 994                         printf("Usage: udevd OPTIONS\n"
 995                                "  --daemon\n"
 996                                "  --debug\n"
 997                                "  --children-max=<maximum number of workers>\n"
 998                                "  --exec-delay=<seconds to wait before executing RUN=>\n"
 999                                "  --resolve-names=early|late|never\n"
1000                                "  --version\n"
1001                                "  --help\n"
1002                                "\n");
1003                         goto exit;
1004                 case 'V':
1005                         printf("%s\n", VERSION);
1006                         goto exit;
1007                 default:
1008                         goto exit;
1009                 }
1010         }
1011
1012         kernel_cmdline_options(udev);
1013
1014         if (getuid() != 0) {
1015                 fprintf(stderr, "root privileges required\n");
1016                 log_error("root privileges required");
1017                 goto exit;
1018         }
1019
1020         /* set umask before creating any file/directory */
1021         chdir("/");
1022         umask(022);
1023
1024         mkdir("/run/udev", 0755);
1025
1026         dev_setup(NULL);
1027
1028         /* before opening new files, make sure std{in,out,err} fds are in a sane state */
1029         if (daemonize) {
1030                 int fd;
1031
1032                 fd = open("/dev/null", O_RDWR);
1033                 if (fd >= 0) {
1034                         if (write(STDOUT_FILENO, 0, 0) < 0)
1035                                 dup2(fd, STDOUT_FILENO);
1036                         if (write(STDERR_FILENO, 0, 0) < 0)
1037                                 dup2(fd, STDERR_FILENO);
1038                         if (fd > STDERR_FILENO)
1039                                 close(fd);
1040                 } else {
1041                         fprintf(stderr, "cannot open /dev/null\n");
1042                         log_error("cannot open /dev/null");
1043                 }
1044         }
1045
1046         if (systemd_fds(udev, &fd_ctrl, &fd_netlink) >= 0) {
1047                 /* get control and netlink socket from systemd */
1048                 udev_ctrl = udev_ctrl_new_from_fd(udev, fd_ctrl);
1049                 if (udev_ctrl == NULL) {
1050                         log_error("error taking over udev control socket");
1051                         rc = 1;
1052                         goto exit;
1053                 }
1054
1055                 monitor = udev_monitor_new_from_netlink_fd(udev, "kernel", fd_netlink);
1056                 if (monitor == NULL) {
1057                         log_error("error taking over netlink socket");
1058                         rc = 3;
1059                         goto exit;
1060                 }
1061
1062                 /* get our own cgroup, we regularly kill everything udev has left behind */
1063                 if (cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, 0, &udev_cgroup) < 0)
1064                         udev_cgroup = NULL;
1065         } else {
1066                 /* open control and netlink socket */
1067                 udev_ctrl = udev_ctrl_new(udev);
1068                 if (udev_ctrl == NULL) {
1069                         fprintf(stderr, "error initializing udev control socket");
1070                         log_error("error initializing udev control socket");
1071                         rc = 1;
1072                         goto exit;
1073                 }
1074                 fd_ctrl = udev_ctrl_get_fd(udev_ctrl);
1075
1076                 monitor = udev_monitor_new_from_netlink(udev, "kernel");
1077                 if (monitor == NULL) {
1078                         fprintf(stderr, "error initializing netlink socket\n");
1079                         log_error("error initializing netlink socket");
1080                         rc = 3;
1081                         goto exit;
1082                 }
1083                 fd_netlink = udev_monitor_get_fd(monitor);
1084         }
1085
1086         if (udev_monitor_enable_receiving(monitor) < 0) {
1087                 fprintf(stderr, "error binding netlink socket\n");
1088                 log_error("error binding netlink socket");
1089                 rc = 3;
1090                 goto exit;
1091         }
1092
1093         if (udev_ctrl_enable_receiving(udev_ctrl) < 0) {
1094                 fprintf(stderr, "error binding udev control socket\n");
1095                 log_error("error binding udev control socket");
1096                 rc = 1;
1097                 goto exit;
1098         }
1099
1100         udev_monitor_set_receive_buffer_size(monitor, 128 * 1024 * 1024);
1101
1102         if (daemonize) {
1103                 pid_t pid;
1104
1105                 pid = fork();
1106                 switch (pid) {
1107                 case 0:
1108                         break;
1109                 case -1:
1110                         log_error("fork of daemon failed: %m");
1111                         rc = 4;
1112                         goto exit;
1113                 default:
1114                         rc = EXIT_SUCCESS;
1115                         goto exit_daemonize;
1116                 }
1117
1118                 setsid();
1119
1120                 write_string_file("/proc/self/oom_score_adj", "-1000");
1121         } else {
1122                 sd_notify(1, "READY=1");
1123         }
1124
1125         print_kmsg("starting version " VERSION "\n");
1126
1127         if (!debug) {
1128                 int fd;
1129
1130                 fd = open("/dev/null", O_RDWR);
1131                 if (fd >= 0) {
1132                         dup2(fd, STDIN_FILENO);
1133                         dup2(fd, STDOUT_FILENO);
1134                         dup2(fd, STDERR_FILENO);
1135                         close(fd);
1136                 }
1137         }
1138
1139         fd_inotify = udev_watch_init(udev);
1140         if (fd_inotify < 0) {
1141                 fprintf(stderr, "error initializing inotify\n");
1142                 log_error("error initializing inotify");
1143                 rc = 4;
1144                 goto exit;
1145         }
1146         udev_watch_restore(udev);
1147
1148         /* block and listen to all signals on signalfd */
1149         sigfillset(&mask);
1150         sigprocmask(SIG_SETMASK, &mask, &sigmask_orig);
1151         fd_signal = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC);
1152         if (fd_signal < 0) {
1153                 fprintf(stderr, "error creating signalfd\n");
1154                 log_error("error creating signalfd");
1155                 rc = 5;
1156                 goto exit;
1157         }
1158
1159         /* unnamed socket from workers to the main daemon */
1160         if (socketpair(AF_LOCAL, SOCK_DGRAM|SOCK_CLOEXEC, 0, worker_watch) < 0) {
1161                 fprintf(stderr, "error creating socketpair\n");
1162                 log_error("error creating socketpair");
1163                 rc = 6;
1164                 goto exit;
1165         }
1166         fd_worker = worker_watch[READ_END];
1167
1168         udev_builtin_init(udev);
1169
1170         rules = udev_rules_new(udev, resolve_names);
1171         if (rules == NULL) {
1172                 log_error("error reading rules");
1173                 goto exit;
1174         }
1175
1176         memzero(&ep_ctrl, sizeof(struct epoll_event));
1177         ep_ctrl.events = EPOLLIN;
1178         ep_ctrl.data.fd = fd_ctrl;
1179
1180         memzero(&ep_inotify, sizeof(struct epoll_event));
1181         ep_inotify.events = EPOLLIN;
1182         ep_inotify.data.fd = fd_inotify;
1183
1184         memzero(&ep_signal, sizeof(struct epoll_event));
1185         ep_signal.events = EPOLLIN;
1186         ep_signal.data.fd = fd_signal;
1187
1188         memzero(&ep_netlink, sizeof(struct epoll_event));
1189         ep_netlink.events = EPOLLIN;
1190         ep_netlink.data.fd = fd_netlink;
1191
1192         memzero(&ep_worker, sizeof(struct epoll_event));
1193         ep_worker.events = EPOLLIN;
1194         ep_worker.data.fd = fd_worker;
1195
1196         fd_ep = epoll_create1(EPOLL_CLOEXEC);
1197         if (fd_ep < 0) {
1198                 log_error("error creating epoll fd: %m");
1199                 goto exit;
1200         }
1201         if (epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_ctrl, &ep_ctrl) < 0 ||
1202             epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_inotify, &ep_inotify) < 0 ||
1203             epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_signal, &ep_signal) < 0 ||
1204             epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_netlink, &ep_netlink) < 0 ||
1205             epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_worker, &ep_worker) < 0) {
1206                 log_error("fail to add fds to epoll: %m");
1207                 goto exit;
1208         }
1209
1210         if (children_max <= 0) {
1211                 cpu_set_t cpu_set;
1212
1213                 children_max = 8;
1214
1215                 if (sched_getaffinity(0, sizeof (cpu_set), &cpu_set) == 0) {
1216                         children_max +=  CPU_COUNT(&cpu_set) * 2;
1217                 }
1218         }
1219         log_debug("set children_max to %u", children_max);
1220
1221         rc = udev_rules_apply_static_dev_perms(rules);
1222         if (rc < 0)
1223                 log_error("failed to apply permissions on static device nodes - %s", strerror(-rc));
1224
1225         udev_list_node_init(&event_list);
1226         udev_list_node_init(&worker_list);
1227
1228         for (;;) {
1229                 static usec_t last_usec;
1230                 struct epoll_event ev[8];
1231                 int fdcount;
1232                 int timeout;
1233                 bool is_worker, is_signal, is_inotify, is_netlink, is_ctrl;
1234                 int i;
1235
1236                 if (udev_exit) {
1237                         /* close sources of new events and discard buffered events */
1238                         if (fd_ctrl >= 0) {
1239                                 epoll_ctl(fd_ep, EPOLL_CTL_DEL, fd_ctrl, NULL);
1240                                 fd_ctrl = -1;
1241                         }
1242                         if (monitor != NULL) {
1243                                 epoll_ctl(fd_ep, EPOLL_CTL_DEL, fd_netlink, NULL);
1244                                 udev_monitor_unref(monitor);
1245                                 monitor = NULL;
1246                         }
1247                         if (fd_inotify >= 0) {
1248                                 epoll_ctl(fd_ep, EPOLL_CTL_DEL, fd_inotify, NULL);
1249                                 close(fd_inotify);
1250                                 fd_inotify = -1;
1251                         }
1252
1253                         /* discard queued events and kill workers */
1254                         event_queue_cleanup(udev, EVENT_QUEUED);
1255                         worker_kill(udev);
1256
1257                         /* exit after all has cleaned up */
1258                         if (udev_list_node_is_empty(&event_list) && children == 0)
1259                                 break;
1260
1261                         /* timeout at exit for workers to finish */
1262                         timeout = 30 * MSEC_PER_SEC;
1263                 } else if (udev_list_node_is_empty(&event_list) && children == 0) {
1264                         /* we are idle */
1265                         timeout = -1;
1266
1267                         /* cleanup possible left-over processes in our cgroup */
1268                         if (udev_cgroup)
1269                                 cg_kill(SYSTEMD_CGROUP_CONTROLLER, udev_cgroup, SIGKILL, false, true, NULL);
1270                 } else {
1271                         /* kill idle or hanging workers */
1272                         timeout = 3 * MSEC_PER_SEC;
1273                 }
1274
1275                 /* tell settle that we are busy or idle */
1276                 if (!udev_list_node_is_empty(&event_list)) {
1277                         int fd;
1278
1279                         fd = open("/run/udev/queue", O_WRONLY|O_CREAT|O_CLOEXEC|O_TRUNC|O_NOFOLLOW, 0444);
1280                         if (fd >= 0)
1281                                 close(fd);
1282                 } else {
1283                         unlink("/run/udev/queue");
1284                 }
1285
1286                 fdcount = epoll_wait(fd_ep, ev, ELEMENTSOF(ev), timeout);
1287                 if (fdcount < 0)
1288                         continue;
1289
1290                 if (fdcount == 0) {
1291                         struct udev_list_node *loop;
1292
1293                         /* timeout */
1294                         if (udev_exit) {
1295                                 log_error("timeout, giving up waiting for workers to finish");
1296                                 break;
1297                         }
1298
1299                         /* kill idle workers */
1300                         if (udev_list_node_is_empty(&event_list)) {
1301                                 log_debug("cleanup idle workers");
1302                                 worker_kill(udev);
1303                         }
1304
1305                         /* check for hanging events */
1306                         udev_list_node_foreach(loop, &worker_list) {
1307                                 struct worker *worker = node_to_worker(loop);
1308
1309                                 if (worker->state != WORKER_RUNNING)
1310                                         continue;
1311
1312                                 if ((now(CLOCK_MONOTONIC) - worker->event_start_usec) > 30 * USEC_PER_SEC) {
1313                                         log_error("worker [%u] %s timeout; kill it", worker->pid,
1314                                             worker->event ? worker->event->devpath : "<idle>");
1315                                         kill(worker->pid, SIGKILL);
1316                                         worker->state = WORKER_KILLED;
1317
1318                                         /* drop reference taken for state 'running' */
1319                                         worker_unref(worker);
1320                                         if (worker->event) {
1321                                                 log_error("seq %llu '%s' killed", udev_device_get_seqnum(worker->event->dev), worker->event->devpath);
1322                                                 worker->event->exitcode = -64;
1323                                                 event_queue_delete(worker->event);
1324                                                 worker->event = NULL;
1325                                         }
1326                                 }
1327                         }
1328
1329                 }
1330
1331                 is_worker = is_signal = is_inotify = is_netlink = is_ctrl = false;
1332                 for (i = 0; i < fdcount; i++) {
1333                         if (ev[i].data.fd == fd_worker && ev[i].events & EPOLLIN)
1334                                 is_worker = true;
1335                         else if (ev[i].data.fd == fd_netlink && ev[i].events & EPOLLIN)
1336                                 is_netlink = true;
1337                         else if (ev[i].data.fd == fd_signal && ev[i].events & EPOLLIN)
1338                                 is_signal = true;
1339                         else if (ev[i].data.fd == fd_inotify && ev[i].events & EPOLLIN)
1340                                 is_inotify = true;
1341                         else if (ev[i].data.fd == fd_ctrl && ev[i].events & EPOLLIN)
1342                                 is_ctrl = true;
1343                 }
1344
1345                 /* check for changed config, every 3 seconds at most */
1346                 if ((now(CLOCK_MONOTONIC) - last_usec) > 3 * USEC_PER_SEC) {
1347                         if (udev_rules_check_timestamp(rules))
1348                                 reload = true;
1349                         if (udev_builtin_validate(udev))
1350                                 reload = true;
1351
1352                         last_usec = now(CLOCK_MONOTONIC);
1353                 }
1354
1355                 /* reload requested, HUP signal received, rules changed, builtin changed */
1356                 if (reload) {
1357                         worker_kill(udev);
1358                         rules = udev_rules_unref(rules);
1359                         udev_builtin_exit(udev);
1360                         reload = false;
1361                 }
1362
1363                 /* event has finished */
1364                 if (is_worker)
1365                         worker_returned(fd_worker);
1366
1367                 if (is_netlink) {
1368                         struct udev_device *dev;
1369
1370                         dev = udev_monitor_receive_device(monitor);
1371                         if (dev != NULL) {
1372                                 udev_device_set_usec_initialized(dev, now(CLOCK_MONOTONIC));
1373                                 if (event_queue_insert(dev) < 0)
1374                                         udev_device_unref(dev);
1375                         }
1376                 }
1377
1378                 /* start new events */
1379                 if (!udev_list_node_is_empty(&event_list) && !udev_exit && !stop_exec_queue) {
1380                         udev_builtin_init(udev);
1381                         if (rules == NULL)
1382                                 rules = udev_rules_new(udev, resolve_names);
1383                         if (rules != NULL)
1384                                 event_queue_start(udev);
1385                 }
1386
1387                 if (is_signal) {
1388                         struct signalfd_siginfo fdsi;
1389                         ssize_t size;
1390
1391                         size = read(fd_signal, &fdsi, sizeof(struct signalfd_siginfo));
1392                         if (size == sizeof(struct signalfd_siginfo))
1393                                 handle_signal(udev, fdsi.ssi_signo);
1394                 }
1395
1396                 /* we are shutting down, the events below are not handled anymore */
1397                 if (udev_exit)
1398                         continue;
1399
1400                 /* device node watch */
1401                 if (is_inotify)
1402                         handle_inotify(udev);
1403
1404                 /*
1405                  * This needs to be after the inotify handling, to make sure,
1406                  * that the ping is send back after the possibly generated
1407                  * "change" events by the inotify device node watch.
1408                  *
1409                  * A single time we may receive a client connection which we need to
1410                  * keep open to block the client. It will be closed right before we
1411                  * exit.
1412                  */
1413                 if (is_ctrl)
1414                         ctrl_conn = handle_ctrl_msg(udev_ctrl);
1415         }
1416
1417         rc = EXIT_SUCCESS;
1418 exit:
1419         udev_ctrl_cleanup(udev_ctrl);
1420         unlink("/run/udev/queue");
1421 exit_daemonize:
1422         if (fd_ep >= 0)
1423                 close(fd_ep);
1424         worker_list_cleanup(udev);
1425         event_queue_cleanup(udev, EVENT_UNDEF);
1426         udev_rules_unref(rules);
1427         udev_builtin_exit(udev);
1428         if (fd_signal >= 0)
1429                 close(fd_signal);
1430         if (worker_watch[READ_END] >= 0)
1431                 close(worker_watch[READ_END]);
1432         if (worker_watch[WRITE_END] >= 0)
1433                 close(worker_watch[WRITE_END]);
1434         udev_monitor_unref(monitor);
1435         udev_ctrl_connection_unref(ctrl_conn);
1436         udev_ctrl_unref(udev_ctrl);
1437         label_finish();
1438         udev_unref(udev);
1439         log_close();
1440         return rc;
1441 }