src/udev/udevd.c

   1 /*
   2  * Copyright (C) 2004-2012 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/epoll.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 #include "sd-daemon.h"
  49 #include "cgroup-util.h"
  50 #include "dev-setup.h"
  51
  52 static bool debug;
  53
  54 void udev_main_log(struct udev *udev, int priority,
  55                    const char *file, int line, const char *fn,
  56                    const char *format, va_list args)
  57 {
  58         log_metav(priority, file, line, fn, format, args);
  59 }
  60
  61 static struct udev_rules *rules;
  62 static struct udev_queue_export *udev_queue_export;
  63 static struct udev_ctrl *udev_ctrl;
  64 static struct udev_monitor *monitor;
  65 static int worker_watch[2] = { -1, -1 };
  66 static int fd_signal = -1;
  67 static int fd_ep = -1;
  68 static int fd_inotify = -1;
  69 static bool stop_exec_queue;
  70 static bool reload;
  71 static int children;
  72 static int children_max;
  73 static int exec_delay;
  74 static sigset_t sigmask_orig;
  75 static UDEV_LIST(event_list);
  76 static UDEV_LIST(worker_list);
  77 char *udev_cgroup;
  78 static bool udev_exit;
  79
  80 enum event_state {
  81         EVENT_UNDEF,
  82         EVENT_QUEUED,
  83         EVENT_RUNNING,
  84 };
  85
  86 struct event {
  87         struct udev_list_node node;
  88         struct udev *udev;
  89         struct udev_device *dev;
  90         enum event_state state;
  91         int exitcode;
  92         unsigned long long int delaying_seqnum;
  93         unsigned long long int seqnum;
  94         const char *devpath;
  95         size_t devpath_len;
  96         const char *devpath_old;
  97         dev_t devnum;
  98         bool is_block;
  99         int ifindex;
 100 };
 101
 102 static inline struct event *node_to_event(struct udev_list_node *node)
 103 {
 104         return container_of(node, struct event, node);
 105 }
 106
 107 static void event_queue_cleanup(struct udev *udev, enum event_state type);
 108
 109 enum worker_state {
 110         WORKER_UNDEF,
 111         WORKER_RUNNING,
 112         WORKER_IDLE,
 113         WORKER_KILLED,
 114 };
 115
 116 struct worker {
 117         struct udev_list_node node;
 118         struct udev *udev;
 119         int refcount;
 120         pid_t pid;
 121         struct udev_monitor *monitor;
 122         enum worker_state state;
 123         struct event *event;
 124         unsigned long long event_start_usec;
 125 };
 126
 127 /* passed from worker to main process */
 128 struct worker_message {
 129         pid_t pid;
 130         int exitcode;
 131 };
 132
 133 static inline struct worker *node_to_worker(struct udev_list_node *node)
 134 {
 135         return container_of(node, struct worker, node);
 136 }
 137
 138 static void event_queue_delete(struct event *event, bool export)
 139 {
 140         udev_list_node_remove(&event->node);
 141
 142         if (export) {
 143                 udev_queue_export_device_finished(udev_queue_export, event->dev);
 144                 log_debug("seq %llu done with %i\n", udev_device_get_seqnum(event->dev), event->exitcode);
 145         }
 146         udev_device_unref(event->dev);
 147         free(event);
 148 }
 149
 150 static struct worker *worker_ref(struct worker *worker)
 151 {
 152         worker->refcount++;
 153         return worker;
 154 }
 155
 156 static void worker_cleanup(struct worker *worker)
 157 {
 158         udev_list_node_remove(&worker->node);
 159         udev_monitor_unref(worker->monitor);
 160         children--;
 161         free(worker);
 162 }
 163
 164 static void worker_unref(struct worker *worker)
 165 {
 166         worker->refcount--;
 167         if (worker->refcount > 0)
 168                 return;
 169         log_debug("worker [%u] cleaned up\n", worker->pid);
 170         worker_cleanup(worker);
 171 }
 172
 173 static void worker_list_cleanup(struct udev *udev)
 174 {
 175         struct udev_list_node *loop, *tmp;
 176
 177         udev_list_node_foreach_safe(loop, tmp, &worker_list) {
 178                 struct worker *worker = node_to_worker(loop);
 179
 180                 worker_cleanup(worker);
 181         }
 182 }
 183
 184 static void worker_new(struct event *event)
 185 {
 186         struct udev *udev = event->udev;
 187         struct worker *worker;
 188         struct udev_monitor *worker_monitor;
 189         pid_t pid;
 190
 191         /* listen for new events */
 192         worker_monitor = udev_monitor_new_from_netlink(udev, NULL);
 193         if (worker_monitor == NULL)
 194                 return;
 195         /* allow the main daemon netlink address to send devices to the worker */
 196         udev_monitor_allow_unicast_sender(worker_monitor, monitor);
 197         udev_monitor_enable_receiving(worker_monitor);
 198
 199         worker = calloc(1, sizeof(struct worker));
 200         if (worker == NULL) {
 201                 udev_monitor_unref(worker_monitor);
 202                 return;
 203         }
 204         /* worker + event reference */
 205         worker->refcount = 2;
 206         worker->udev = udev;
 207
 208         pid = fork();
 209         switch (pid) {
 210         case 0: {
 211                 struct udev_device *dev = NULL;
 212                 int fd_monitor;
 213                 struct epoll_event ep_signal, ep_monitor;
 214                 sigset_t mask;
 215                 int rc = EXIT_SUCCESS;
 216
 217                 /* take initial device from queue */
 218                 dev = event->dev;
 219                 event->dev = NULL;
 220
 221                 free(worker);
 222                 worker_list_cleanup(udev);
 223                 event_queue_cleanup(udev, EVENT_UNDEF);
 224                 udev_queue_export_unref(udev_queue_export);
 225                 udev_monitor_unref(monitor);
 226                 udev_ctrl_unref(udev_ctrl);
 227                 close(fd_signal);
 228                 close(fd_ep);
 229                 close(worker_watch[READ_END]);
 230
 231                 sigfillset(&mask);
 232                 fd_signal = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC);
 233                 if (fd_signal < 0) {
 234                         log_error("error creating signalfd %m\n");
 235                         rc = 2;
 236                         goto out;
 237                 }
 238
 239                 fd_ep = epoll_create1(EPOLL_CLOEXEC);
 240                 if (fd_ep < 0) {
 241                         log_error("error creating epoll fd: %m\n");
 242                         rc = 3;
 243                         goto out;
 244                 }
 245
 246                 memset(&ep_signal, 0, sizeof(struct epoll_event));
 247                 ep_signal.events = EPOLLIN;
 248                 ep_signal.data.fd = fd_signal;
 249
 250                 fd_monitor = udev_monitor_get_fd(worker_monitor);
 251                 memset(&ep_monitor, 0, sizeof(struct epoll_event));
 252                 ep_monitor.events = EPOLLIN;
 253                 ep_monitor.data.fd = fd_monitor;
 254
 255                 if (epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_signal, &ep_signal) < 0 ||
 256                     epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_monitor, &ep_monitor) < 0) {
 257                         log_error("fail to add fds to epoll: %m\n");
 258                         rc = 4;
 259                         goto out;
 260                 }
 261
 262                 /* request TERM signal if parent exits */
 263                 prctl(PR_SET_PDEATHSIG, SIGTERM);
 264
 265                 for (;;) {
 266                         struct udev_event *udev_event;
 267                         struct worker_message msg;
 268                         int err;
 269
 270                         log_debug("seq %llu running\n", udev_device_get_seqnum(dev));
 271                         udev_event = udev_event_new(dev);
 272                         if (udev_event == NULL) {
 273                                 rc = 5;
 274                                 goto out;
 275                         }
 276
 277                         /* needed for SIGCHLD/SIGTERM in spawn() */
 278                         udev_event->fd_signal = fd_signal;
 279
 280                         if (exec_delay > 0)
 281                                 udev_event->exec_delay = exec_delay;
 282
 283                         /* apply rules, create node, symlinks */
 284                         err = udev_event_execute_rules(udev_event, rules, &sigmask_orig);
 285
 286                         if (err == 0)
 287                                 udev_event_execute_run(udev_event, &sigmask_orig);
 288
 289                         /* apply/restore inotify watch */
 290                         if (err == 0 && udev_event->inotify_watch) {
 291                                 udev_watch_begin(udev, dev);
 292                                 udev_device_update_db(dev);
 293                         }
 294
 295                         /* send processed event back to libudev listeners */
 296                         udev_monitor_send_device(worker_monitor, NULL, dev);
 297
 298                         /* send udevd the result of the event execution */
 299                         memset(&msg, 0, sizeof(struct worker_message));
 300                         if (err != 0)
 301                                 msg.exitcode = err;
 302                         msg.pid = getpid();
 303                         send(worker_watch[WRITE_END], &msg, sizeof(struct worker_message), 0);
 304
 305                         log_debug("seq %llu processed with %i\n", udev_device_get_seqnum(dev), err);
 306
 307                         udev_device_unref(dev);
 308                         dev = NULL;
 309
 310                         if (udev_event->sigterm) {
 311                                 udev_event_unref(udev_event);
 312                                 goto out;
 313                         }
 314
 315                         udev_event_unref(udev_event);
 316
 317                         /* wait for more device messages from main udevd, or term signal */
 318                         while (dev == NULL) {
 319                                 struct epoll_event ev[4];
 320                                 int fdcount;
 321                                 int i;
 322
 323                                 fdcount = epoll_wait(fd_ep, ev, ELEMENTSOF(ev), -1);
 324                                 if (fdcount < 0) {
 325                                         if (errno == EINTR)
 326                                                 continue;
 327                                         log_error("failed to poll: %m\n");
 328                                         goto out;
 329                                 }
 330
 331                                 for (i = 0; i < fdcount; i++) {
 332                                         if (ev[i].data.fd == fd_monitor && ev[i].events & EPOLLIN) {
 333                                                 dev = udev_monitor_receive_device(worker_monitor);
 334                                                 break;
 335                                         } else if (ev[i].data.fd == fd_signal && ev[i].events & EPOLLIN) {
 336                                                 struct signalfd_siginfo fdsi;
 337                                                 ssize_t size;
 338
 339                                                 size = read(fd_signal, &fdsi, sizeof(struct signalfd_siginfo));
 340                                                 if (size != sizeof(struct signalfd_siginfo))
 341                                                         continue;
 342                                                 switch (fdsi.ssi_signo) {
 343                                                 case SIGTERM:
 344                                                         goto out;
 345                                                 }
 346                                         }
 347                                 }
 348                         }
 349                 }
 350 out:
 351                 udev_device_unref(dev);
 352                 if (fd_signal >= 0)
 353                         close(fd_signal);
 354                 if (fd_ep >= 0)
 355                         close(fd_ep);
 356                 close(fd_inotify);
 357                 close(worker_watch[WRITE_END]);
 358                 udev_rules_unref(rules);
 359                 udev_builtin_exit(udev);
 360                 udev_monitor_unref(worker_monitor);
 361                 udev_unref(udev);
 362                 log_close();
 363                 exit(rc);
 364         }
 365         case -1:
 366                 udev_monitor_unref(worker_monitor);
 367                 event->state = EVENT_QUEUED;
 368                 free(worker);
 369                 log_error("fork of child failed: %m\n");
 370                 break;
 371         default:
 372                 /* close monitor, but keep address around */
 373                 udev_monitor_disconnect(worker_monitor);
 374                 worker->monitor = worker_monitor;
 375                 worker->pid = pid;
 376                 worker->state = WORKER_RUNNING;
 377                 worker->event_start_usec = now_usec();
 378                 worker->event = event;
 379                 event->state = EVENT_RUNNING;
 380                 udev_list_node_append(&worker->node, &worker_list);
 381                 children++;
 382                 log_debug("seq %llu forked new worker [%u]\n", udev_device_get_seqnum(event->dev), pid);
 383                 break;
 384         }
 385 }
 386
 387 static void event_run(struct event *event)
 388 {
 389         struct udev_list_node *loop;
 390
 391         udev_list_node_foreach(loop, &worker_list) {
 392                 struct worker *worker = node_to_worker(loop);
 393                 ssize_t count;
 394
 395                 if (worker->state != WORKER_IDLE)
 396                         continue;
 397
 398                 count = udev_monitor_send_device(monitor, worker->monitor, event->dev);
 399                 if (count < 0) {
 400                         log_error("worker [%u] did not accept message %zi (%m), kill it\n", worker->pid, count);
 401                         kill(worker->pid, SIGKILL);
 402                         worker->state = WORKER_KILLED;
 403                         continue;
 404                 }
 405                 worker_ref(worker);
 406                 worker->event = event;
 407                 worker->state = WORKER_RUNNING;
 408                 worker->event_start_usec = now_usec();
 409                 event->state = EVENT_RUNNING;
 410                 return;
 411         }
 412
 413         if (children >= children_max) {
 414                 if (children_max > 1)
 415                         log_debug("maximum number (%i) of children reached\n", children);
 416                 return;
 417         }
 418
 419         /* start new worker and pass initial device */
 420         worker_new(event);
 421 }
 422
 423 static int event_queue_insert(struct udev_device *dev)
 424 {
 425         struct event *event;
 426
 427         event = calloc(1, sizeof(struct event));
 428         if (event == NULL)
 429                 return -1;
 430
 431         event->udev = udev_device_get_udev(dev);
 432         event->dev = dev;
 433         event->seqnum = udev_device_get_seqnum(dev);
 434         event->devpath = udev_device_get_devpath(dev);
 435         event->devpath_len = strlen(event->devpath);
 436         event->devpath_old = udev_device_get_devpath_old(dev);
 437         event->devnum = udev_device_get_devnum(dev);
 438         event->is_block = (strcmp("block", udev_device_get_subsystem(dev)) == 0);
 439         event->ifindex = udev_device_get_ifindex(dev);
 440
 441         udev_queue_export_device_queued(udev_queue_export, dev);
 442         log_debug("seq %llu queued, '%s' '%s'\n", udev_device_get_seqnum(dev),
 443              udev_device_get_action(dev), udev_device_get_subsystem(dev));
 444
 445         event->state = EVENT_QUEUED;
 446         udev_list_node_append(&event->node, &event_list);
 447         return 0;
 448 }
 449
 450 static void worker_kill(struct udev *udev)
 451 {
 452         struct udev_list_node *loop;
 453
 454         udev_list_node_foreach(loop, &worker_list) {
 455                 struct worker *worker = node_to_worker(loop);
 456
 457                 if (worker->state == WORKER_KILLED)
 458                         continue;
 459
 460                 worker->state = WORKER_KILLED;
 461                 kill(worker->pid, SIGTERM);
 462         }
 463 }
 464
 465 /* lookup event for identical, parent, child device */
 466 static bool is_devpath_busy(struct event *event)
 467 {
 468         struct udev_list_node *loop;
 469         size_t common;
 470
 471         /* check if queue contains events we depend on */
 472         udev_list_node_foreach(loop, &event_list) {
 473                 struct event *loop_event = node_to_event(loop);
 474
 475                 /* we already found a later event, earlier can not block us, no need to check again */
 476                 if (loop_event->seqnum < event->delaying_seqnum)
 477                         continue;
 478
 479                 /* event we checked earlier still exists, no need to check again */
 480                 if (loop_event->seqnum == event->delaying_seqnum)
 481                         return true;
 482
 483                 /* found ourself, no later event can block us */
 484                 if (loop_event->seqnum >= event->seqnum)
 485                         break;
 486
 487                 /* check major/minor */
 488                 if (major(event->devnum) != 0 && event->devnum == loop_event->devnum && event->is_block == loop_event->is_block)
 489                         return true;
 490
 491                 /* check network device ifindex */
 492                 if (event->ifindex != 0 && event->ifindex == loop_event->ifindex)
 493                         return true;
 494
 495                 /* check our old name */
 496                 if (event->devpath_old != NULL && strcmp(loop_event->devpath, event->devpath_old) == 0) {
 497                         event->delaying_seqnum = loop_event->seqnum;
 498                         return true;
 499                 }
 500
 501                 /* compare devpath */
 502                 common = MIN(loop_event->devpath_len, event->devpath_len);
 503
 504                 /* one devpath is contained in the other? */
 505                 if (memcmp(loop_event->devpath, event->devpath, common) != 0)
 506                         continue;
 507
 508                 /* identical device event found */
 509                 if (loop_event->devpath_len == event->devpath_len) {
 510                         /* devices names might have changed/swapped in the meantime */
 511                         if (major(event->devnum) != 0 && (event->devnum != loop_event->devnum || event->is_block != loop_event->is_block))
 512                                 continue;
 513                         if (event->ifindex != 0 && event->ifindex != loop_event->ifindex)
 514                                 continue;
 515                         event->delaying_seqnum = loop_event->seqnum;
 516                         return true;
 517                 }
 518
 519                 /* parent device event found */
 520                 if (event->devpath[common] == '/') {
 521                         event->delaying_seqnum = loop_event->seqnum;
 522                         return true;
 523                 }
 524
 525                 /* child device event found */
 526                 if (loop_event->devpath[common] == '/') {
 527                         event->delaying_seqnum = loop_event->seqnum;
 528                         return true;
 529                 }
 530
 531                 /* no matching device */
 532                 continue;
 533         }
 534
 535         return false;
 536 }
 537
 538 static void event_queue_start(struct udev *udev)
 539 {
 540         struct udev_list_node *loop;
 541
 542         udev_list_node_foreach(loop, &event_list) {
 543                 struct event *event = node_to_event(loop);
 544
 545                 if (event->state != EVENT_QUEUED)
 546                         continue;
 547
 548                 /* do not start event if parent or child event is still running */
 549                 if (is_devpath_busy(event))
 550                         continue;
 551
 552                 event_run(event);
 553         }
 554 }
 555
 556 static void event_queue_cleanup(struct udev *udev, enum event_state match_type)
 557 {
 558         struct udev_list_node *loop, *tmp;
 559
 560         udev_list_node_foreach_safe(loop, tmp, &event_list) {
 561                 struct event *event = node_to_event(loop);
 562
 563                 if (match_type != EVENT_UNDEF && match_type != event->state)
 564                         continue;
 565
 566                 event_queue_delete(event, false);
 567         }
 568 }
 569
 570 static void worker_returned(int fd_worker)
 571 {
 572         for (;;) {
 573                 struct worker_message msg;
 574                 ssize_t size;
 575                 struct udev_list_node *loop;
 576
 577                 size = recv(fd_worker, &msg, sizeof(struct worker_message), MSG_DONTWAIT);
 578                 if (size != sizeof(struct worker_message))
 579                         break;
 580
 581                 /* lookup worker who sent the signal */
 582                 udev_list_node_foreach(loop, &worker_list) {
 583                         struct worker *worker = node_to_worker(loop);
 584
 585                         if (worker->pid != msg.pid)
 586                                 continue;
 587
 588                         /* worker returned */
 589                         if (worker->event) {
 590                                 worker->event->exitcode = msg.exitcode;
 591                                 event_queue_delete(worker->event, true);
 592                                 worker->event = NULL;
 593                         }
 594                         if (worker->state != WORKER_KILLED)
 595                                 worker->state = WORKER_IDLE;
 596                         worker_unref(worker);
 597                         break;
 598                 }
 599         }
 600 }
 601
 602 /* receive the udevd message from userspace */
 603 static struct udev_ctrl_connection *handle_ctrl_msg(struct udev_ctrl *uctrl)
 604 {
 605         struct udev *udev = udev_ctrl_get_udev(uctrl);
 606         struct udev_ctrl_connection *ctrl_conn;
 607         struct udev_ctrl_msg *ctrl_msg = NULL;
 608         const char *str;
 609         int i;
 610
 611         ctrl_conn = udev_ctrl_get_connection(uctrl);
 612         if (ctrl_conn == NULL)
 613                 goto out;
 614
 615         ctrl_msg = udev_ctrl_receive_msg(ctrl_conn);
 616         if (ctrl_msg == NULL)
 617                 goto out;
 618
 619         i = udev_ctrl_get_set_log_level(ctrl_msg);
 620         if (i >= 0) {
 621                 log_debug("udevd message (SET_LOG_PRIORITY) received, log_priority=%i\n", i);
 622                 log_set_max_level(i);
 623                 udev_set_log_priority(udev, i);
 624                 worker_kill(udev);
 625         }
 626
 627         if (udev_ctrl_get_stop_exec_queue(ctrl_msg) > 0) {
 628                 log_debug("udevd message (STOP_EXEC_QUEUE) received\n");
 629                 stop_exec_queue = true;
 630         }
 631
 632         if (udev_ctrl_get_start_exec_queue(ctrl_msg) > 0) {
 633                 log_debug("udevd message (START_EXEC_QUEUE) received\n");
 634                 stop_exec_queue = false;
 635         }
 636
 637         if (udev_ctrl_get_reload(ctrl_msg) > 0) {
 638                 log_debug("udevd message (RELOAD) received\n");
 639                 reload = true;
 640         }
 641
 642         str = udev_ctrl_get_set_env(ctrl_msg);
 643         if (str != NULL) {
 644                 char *key;
 645
 646                 key = strdup(str);
 647                 if (key != NULL) {
 648                         char *val;
 649
 650                         val = strchr(key, '=');
 651                         if (val != NULL) {
 652                                 val[0] = '\0';
 653                                 val = &val[1];
 654                                 if (val[0] == '\0') {
 655                                         log_debug("udevd message (ENV) received, unset '%s'\n", key);
 656                                         udev_add_property(udev, key, NULL);
 657                                 } else {
 658                                         log_debug("udevd message (ENV) received, set '%s=%s'\n", key, val);
 659                                         udev_add_property(udev, key, val);
 660                                 }
 661                         } else {
 662                                 log_error("wrong key format '%s'\n", key);
 663                         }
 664                         free(key);
 665                 }
 666                 worker_kill(udev);
 667         }
 668
 669         i = udev_ctrl_get_set_children_max(ctrl_msg);
 670         if (i >= 0) {
 671                 log_debug("udevd message (SET_MAX_CHILDREN) received, children_max=%i\n", i);
 672                 children_max = i;
 673         }
 674
 675         if (udev_ctrl_get_ping(ctrl_msg) > 0)
 676                 log_debug("udevd message (SYNC) received\n");
 677
 678         if (udev_ctrl_get_exit(ctrl_msg) > 0) {
 679                 log_debug("udevd message (EXIT) received\n");
 680                 udev_exit = true;
 681                 /* keep reference to block the client until we exit */
 682                 udev_ctrl_connection_ref(ctrl_conn);
 683         }
 684 out:
 685         udev_ctrl_msg_unref(ctrl_msg);
 686         return udev_ctrl_connection_unref(ctrl_conn);
 687 }
 688
 689 /* read inotify messages */
 690 static int handle_inotify(struct udev *udev)
 691 {
 692         int nbytes, pos;
 693         char *buf;
 694         struct inotify_event *ev;
 695
 696         if ((ioctl(fd_inotify, FIONREAD, &nbytes) < 0) || (nbytes <= 0))
 697                 return 0;
 698
 699         buf = malloc(nbytes);
 700         if (buf == NULL) {
 701                 log_error("error getting buffer for inotify\n");
 702                 return -1;
 703         }
 704
 705         nbytes = read(fd_inotify, buf, nbytes);
 706
 707         for (pos = 0; pos < nbytes; pos += sizeof(struct inotify_event) + ev->len) {
 708                 struct udev_device *dev;
 709
 710                 ev = (struct inotify_event *)(buf + pos);
 711                 dev = udev_watch_lookup(udev, ev->wd);
 712                 if (dev != NULL) {
 713                         log_debug("inotify event: %x for %s\n", ev->mask, udev_device_get_devnode(dev));
 714                         if (ev->mask & IN_CLOSE_WRITE) {
 715                                 char filename[UTIL_PATH_SIZE];
 716                                 int fd;
 717
 718                                 log_debug("device %s closed, synthesising 'change'\n", udev_device_get_devnode(dev));
 719                                 util_strscpyl(filename, sizeof(filename), udev_device_get_syspath(dev), "/uevent", NULL);
 720                                 fd = open(filename, O_WRONLY);
 721                                 if (fd >= 0) {
 722                                         if (write(fd, "change", 6) < 0)
 723                                                 log_debug("error writing uevent: %m\n");
 724                                         close(fd);
 725                                 }
 726                         }
 727                         if (ev->mask & IN_IGNORED)
 728                                 udev_watch_end(udev, dev);
 729
 730                         udev_device_unref(dev);
 731                 }
 732
 733         }
 734
 735         free(buf);
 736         return 0;
 737 }
 738
 739 static void handle_signal(struct udev *udev, int signo)
 740 {
 741         switch (signo) {
 742         case SIGINT:
 743         case SIGTERM:
 744                 udev_exit = true;
 745                 break;
 746         case SIGCHLD:
 747                 for (;;) {
 748                         pid_t pid;
 749                         int status;
 750                         struct udev_list_node *loop, *tmp;
 751
 752                         pid = waitpid(-1, &status, WNOHANG);
 753                         if (pid <= 0)
 754                                 break;
 755
 756                         udev_list_node_foreach_safe(loop, tmp, &worker_list) {
 757                                 struct worker *worker = node_to_worker(loop);
 758
 759                                 if (worker->pid != pid)
 760                                         continue;
 761                                 log_debug("worker [%u] exit\n", pid);
 762
 763                                 if (WIFEXITED(status)) {
 764                                         if (WEXITSTATUS(status) != 0)
 765                                                 log_error("worker [%u] exit with return code %i\n", pid, WEXITSTATUS(status));
 766                                 } else if (WIFSIGNALED(status)) {
 767                                         log_error("worker [%u] terminated by signal %i (%s)\n",
 768                                             pid, WTERMSIG(status), strsignal(WTERMSIG(status)));
 769                                 } else if (WIFSTOPPED(status)) {
 770                                         log_error("worker [%u] stopped\n", pid);
 771                                 } else if (WIFCONTINUED(status)) {
 772                                         log_error("worker [%u] continued\n", pid);
 773                                 } else {
 774                                         log_error("worker [%u] exit with status 0x%04x\n", pid, status);
 775                                 }
 776
 777                                 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
 778                                         if (worker->event) {
 779                                                 log_error("worker [%u] failed while handling '%s'\n",
 780                                                           pid, worker->event->devpath);
 781                                                 worker->event->exitcode = -32;
 782                                                 event_queue_delete(worker->event, true);
 783                                                 /* drop reference taken for state 'running' */
 784                                                 worker_unref(worker);
 785                                         }
 786                                 }
 787                                 worker_unref(worker);
 788                                 break;
 789                         }
 790                 }
 791                 break;
 792         case SIGHUP:
 793                 reload = true;
 794                 break;
 795         }
 796 }
 797
 798 static void static_dev_create_from_modules(struct udev *udev)
 799 {
 800         struct utsname kernel;
 801         char modules[UTIL_PATH_SIZE];
 802         char buf[4096];
 803         FILE *f;
 804
 805         uname(&kernel);
 806         util_strscpyl(modules, sizeof(modules), "/lib/modules/", kernel.release, "/modules.devname", NULL);
 807         f = fopen(modules, "r");
 808         if (f == NULL)
 809                 return;
 810
 811         while (fgets(buf, sizeof(buf), f) != NULL) {
 812                 char *s;
 813                 const char *modname;
 814                 const char *devname;
 815                 const char *devno;
 816                 int maj, min;
 817                 char type;
 818                 mode_t mode;
 819                 char filename[UTIL_PATH_SIZE];
 820
 821                 if (buf[0] == '#')
 822                         continue;
 823
 824                 modname = buf;
 825                 s = strchr(modname, ' ');
 826                 if (s == NULL)
 827                         continue;
 828                 s[0] = '\0';
 829
 830                 devname = &s[1];
 831                 s = strchr(devname, ' ');
 832                 if (s == NULL)
 833                         continue;
 834                 s[0] = '\0';
 835
 836                 devno = &s[1];
 837                 s = strchr(devno, ' ');
 838                 if (s == NULL)
 839                         s = strchr(devno, '\n');
 840                 if (s != NULL)
 841                         s[0] = '\0';
 842                 if (sscanf(devno, "%c%u:%u", &type, &maj, &min) != 3)
 843                         continue;
 844
 845                 if (type == 'c')
 846                         mode = S_IFCHR;
 847                 else if (type == 'b')
 848                         mode = S_IFBLK;
 849                 else
 850                         continue;
 851
 852                 util_strscpyl(filename, sizeof(filename), "/dev/", devname, NULL);
 853                 mkdir_parents_label(filename, 0755);
 854                 label_context_set(filename, mode);
 855                 log_debug("mknod '%s' %c%u:%u\n", filename, type, maj, min);
 856                 if (mknod(filename, mode, makedev(maj, min)) < 0 && errno == EEXIST)
 857                         utimensat(AT_FDCWD, filename, NULL, 0);
 858                 label_context_clear();
 859         }
 860
 861         fclose(f);
 862 }
 863
 864 static int mem_size_mb(void)
 865 {
 866         FILE *f;
 867         char buf[4096];
 868         long int memsize = -1;
 869
 870         f = fopen("/proc/meminfo", "r");
 871         if (f == NULL)
 872                 return -1;
 873
 874         while (fgets(buf, sizeof(buf), f) != NULL) {
 875                 long int value;
 876
 877                 if (sscanf(buf, "MemTotal: %ld kB", &value) == 1) {
 878                         memsize = value / 1024;
 879                         break;
 880                 }
 881         }
 882
 883         fclose(f);
 884         return memsize;
 885 }
 886
 887 static int convert_db(struct udev *udev)
 888 {
 889         char filename[UTIL_PATH_SIZE];
 890         FILE *f;
 891         struct udev_enumerate *udev_enumerate;
 892         struct udev_list_entry *list_entry;
 893
 894         /* current database */
 895         if (access("/run/udev/data", F_OK) >= 0)
 896                 return 0;
 897
 898         /* make sure we do not get here again */
 899         mkdir_parents("/run/udev/data", 0755);
 900         mkdir(filename, 0755);
 901
 902         /* old database */
 903         util_strscpyl(filename, sizeof(filename), "/dev/.udev/db", NULL);
 904         if (access(filename, F_OK) < 0)
 905                 return 0;
 906
 907         f = fopen("/dev/kmsg", "w");
 908         if (f != NULL) {
 909                 fprintf(f, "<30>udevd[%u]: converting old udev database\n", getpid());
 910                 fclose(f);
 911         }
 912
 913         udev_enumerate = udev_enumerate_new(udev);
 914         if (udev_enumerate == NULL)
 915                 return -1;
 916         udev_enumerate_scan_devices(udev_enumerate);
 917         udev_list_entry_foreach(list_entry, udev_enumerate_get_list_entry(udev_enumerate)) {
 918                 struct udev_device *device;
 919
 920                 device = udev_device_new_from_syspath(udev, udev_list_entry_get_name(list_entry));
 921                 if (device == NULL)
 922                         continue;
 923
 924                 /* try to find the old database for devices without a current one */
 925                 if (udev_device_read_db(device, NULL) < 0) {
 926                         bool have_db;
 927                         const char *id;
 928                         struct stat stats;
 929                         char devpath[UTIL_PATH_SIZE];
 930                         char from[UTIL_PATH_SIZE];
 931
 932                         have_db = false;
 933
 934                         /* find database in old location */
 935                         id = udev_device_get_id_filename(device);
 936                         util_strscpyl(from, sizeof(from), "/dev/.udev/db/", id, NULL);
 937                         if (lstat(from, &stats) == 0) {
 938                                 if (!have_db) {
 939                                         udev_device_read_db(device, from);
 940                                         have_db = true;
 941                                 }
 942                                 unlink(from);
 943                         }
 944
 945                         /* find old database with $subsys:$sysname name */
 946                         util_strscpyl(from, sizeof(from), "/dev/.udev/db/",
 947                                       udev_device_get_subsystem(device), ":", udev_device_get_sysname(device), NULL);
 948                         if (lstat(from, &stats) == 0) {
 949                                 if (!have_db) {
 950                                         udev_device_read_db(device, from);
 951                                         have_db = true;
 952                                 }
 953                                 unlink(from);
 954                         }
 955
 956                         /* find old database with the encoded devpath name */
 957                         util_path_encode(udev_device_get_devpath(device), devpath, sizeof(devpath));
 958                         util_strscpyl(from, sizeof(from), "/dev/.udev/db/", devpath, NULL);
 959                         if (lstat(from, &stats) == 0) {
 960                                 if (!have_db) {
 961                                         udev_device_read_db(device, from);
 962                                         have_db = true;
 963                                 }
 964                                 unlink(from);
 965                         }
 966
 967                         /* write out new database */
 968                         if (have_db)
 969                                 udev_device_update_db(device);
 970                 }
 971                 udev_device_unref(device);
 972         }
 973         udev_enumerate_unref(udev_enumerate);
 974         return 0;
 975 }
 976
 977 static int systemd_fds(struct udev *udev, int *rctrl, int *rnetlink)
 978 {
 979         int ctrl = -1, netlink = -1;
 980         int fd, n;
 981
 982         n = sd_listen_fds(true);
 983         if (n <= 0)
 984                 return -1;
 985
 986         for (fd = SD_LISTEN_FDS_START; fd < n + SD_LISTEN_FDS_START; fd++) {
 987                 if (sd_is_socket(fd, AF_LOCAL, SOCK_SEQPACKET, -1)) {
 988                         if (ctrl >= 0)
 989                                 return -1;
 990                         ctrl = fd;
 991                         continue;
 992                 }
 993
 994                 if (sd_is_socket(fd, AF_NETLINK, SOCK_RAW, -1)) {
 995                         if (netlink >= 0)
 996                                 return -1;
 997                         netlink = fd;
 998                         continue;
 999                 }
1000
1001                 return -1;
1002         }
1003
1004         if (ctrl < 0 || netlink < 0)
1005                 return -1;
1006
1007         log_debug("ctrl=%i netlink=%i\n", ctrl, netlink);
1008         *rctrl = ctrl;
1009         *rnetlink = netlink;
1010         return 0;
1011 }
1012
1013 int main(int argc, char *argv[])
1014 {
1015         struct udev *udev;
1016         FILE *f;
1017         sigset_t mask;
1018         int daemonize = false;
1019         int resolve_names = 1;
1020         static const struct option options[] = {
1021                 { "daemon", no_argument, NULL, 'd' },
1022                 { "debug", no_argument, NULL, 'D' },
1023                 { "children-max", required_argument, NULL, 'c' },
1024                 { "exec-delay", required_argument, NULL, 'e' },
1025                 { "resolve-names", required_argument, NULL, 'N' },
1026                 { "help", no_argument, NULL, 'h' },
1027                 { "version", no_argument, NULL, 'V' },
1028                 {}
1029         };
1030         int fd_ctrl = -1;
1031         int fd_netlink = -1;
1032         int fd_worker = -1;
1033         const char *prefixes[] = { "/dev", "/run", NULL };
1034         struct epoll_event ep_ctrl, ep_inotify, ep_signal, ep_netlink, ep_worker;
1035         struct udev_ctrl_connection *ctrl_conn = NULL;
1036         int rc = 1;
1037
1038         udev = udev_new();
1039         if (udev == NULL)
1040                 goto exit;
1041
1042         log_open();
1043         log_parse_environment();
1044         udev_set_log_fn(udev, udev_main_log);
1045         log_debug("version %s\n", VERSION);
1046         label_init(prefixes);
1047
1048         for (;;) {
1049                 int option;
1050
1051                 option = getopt_long(argc, argv, "c:deDtN:hV", options, NULL);
1052                 if (option == -1)
1053                         break;
1054
1055                 switch (option) {
1056                 case 'd':
1057                         daemonize = true;
1058                         break;
1059                 case 'c':
1060                         children_max = strtoul(optarg, NULL, 0);
1061                         break;
1062                 case 'e':
1063                         exec_delay = strtoul(optarg, NULL, 0);
1064                         break;
1065                 case 'D':
1066                         debug = true;
1067                         log_set_max_level(LOG_DEBUG);
1068                         udev_set_log_priority(udev, LOG_INFO);
1069                         break;
1070                 case 'N':
1071                         if (strcmp (optarg, "early") == 0) {
1072                                 resolve_names = 1;
1073                         } else if (strcmp (optarg, "late") == 0) {
1074                                 resolve_names = 0;
1075                         } else if (strcmp (optarg, "never") == 0) {
1076                                 resolve_names = -1;
1077                         } else {
1078                                 fprintf(stderr, "resolve-names must be early, late or never\n");
1079                                 log_error("resolve-names must be early, late or never\n");
1080                                 goto exit;
1081                         }
1082                         break;
1083                 case 'h':
1084                         printf("Usage: udevd OPTIONS\n"
1085                                "  --daemon\n"
1086                                "  --debug\n"
1087                                "  --children-max=<maximum number of workers>\n"
1088                                "  --exec-delay=<seconds to wait before executing RUN=>\n"
1089                                "  --resolve-names=early|late|never\n"
1090                                "  --version\n"
1091                                "  --help\n"
1092                                "\n");
1093                         goto exit;
1094                 case 'V':
1095                         printf("%s\n", VERSION);
1096                         goto exit;
1097                 default:
1098                         goto exit;
1099                 }
1100         }
1101
1102         /*
1103          * read the kernel commandline, in case we need to get into debug mode
1104          *   udev.log-priority=<level>              syslog priority
1105          *   udev.children-max=<number of workers>  events are fully serialized if set to 1
1106          *
1107          */
1108         f = fopen("/proc/cmdline", "r");
1109         if (f != NULL) {
1110                 char cmdline[4096];
1111
1112                 if (fgets(cmdline, sizeof(cmdline), f) != NULL) {
1113                         char *pos;
1114
1115                         pos = strstr(cmdline, "udev.log-priority=");
1116                         if (pos != NULL) {
1117                                 pos += strlen("udev.log-priority=");
1118                                 udev_set_log_priority(udev, util_log_priority(pos));
1119                         }
1120
1121                         pos = strstr(cmdline, "udev.children-max=");
1122                         if (pos != NULL) {
1123                                 pos += strlen("udev.children-max=");
1124                                 children_max = strtoul(pos, NULL, 0);
1125                         }
1126
1127                         pos = strstr(cmdline, "udev.exec-delay=");
1128                         if (pos != NULL) {
1129                                 pos += strlen("udev.exec-delay=");
1130                                 exec_delay = strtoul(pos, NULL, 0);
1131                         }
1132                 }
1133                 fclose(f);
1134         }
1135
1136         if (getuid() != 0) {
1137                 fprintf(stderr, "root privileges required\n");
1138                 log_error("root privileges required\n");
1139                 goto exit;
1140         }
1141
1142         /* set umask before creating any file/directory */
1143         chdir("/");
1144         umask(022);
1145
1146         mkdir("/run/udev", 0755);
1147
1148         dev_setup();
1149         static_dev_create_from_modules(udev);
1150
1151         /* before opening new files, make sure std{in,out,err} fds are in a sane state */
1152         if (daemonize) {
1153                 int fd;
1154
1155                 fd = open("/dev/null", O_RDWR);
1156                 if (fd >= 0) {
1157                         if (write(STDOUT_FILENO, 0, 0) < 0)
1158                                 dup2(fd, STDOUT_FILENO);
1159                         if (write(STDERR_FILENO, 0, 0) < 0)
1160                                 dup2(fd, STDERR_FILENO);
1161                         if (fd > STDERR_FILENO)
1162                                 close(fd);
1163                 } else {
1164                         fprintf(stderr, "cannot open /dev/null\n");
1165                         log_error("cannot open /dev/null\n");
1166                 }
1167         }
1168
1169         if (systemd_fds(udev, &fd_ctrl, &fd_netlink) >= 0) {
1170                 /* get control and netlink socket from from systemd */
1171                 udev_ctrl = udev_ctrl_new_from_fd(udev, fd_ctrl);
1172                 if (udev_ctrl == NULL) {
1173                         log_error("error taking over udev control socket");
1174                         rc = 1;
1175                         goto exit;
1176                 }
1177
1178                 monitor = udev_monitor_new_from_netlink_fd(udev, "kernel", fd_netlink);
1179                 if (monitor == NULL) {
1180                         log_error("error taking over netlink socket\n");
1181                         rc = 3;
1182                         goto exit;
1183                 }
1184
1185                 /* get our own cgroup, we regularly kill everything udev has left behind */
1186                 if (cg_get_by_pid(SYSTEMD_CGROUP_CONTROLLER, 0, &udev_cgroup) < 0)
1187                         udev_cgroup = NULL;
1188         } else {
1189                 /* open control and netlink socket */
1190                 udev_ctrl = udev_ctrl_new(udev);
1191                 if (udev_ctrl == NULL) {
1192                         fprintf(stderr, "error initializing udev control socket");
1193                         log_error("error initializing udev control socket");
1194                         rc = 1;
1195                         goto exit;
1196                 }
1197                 fd_ctrl = udev_ctrl_get_fd(udev_ctrl);
1198
1199                 monitor = udev_monitor_new_from_netlink(udev, "kernel");
1200                 if (monitor == NULL) {
1201                         fprintf(stderr, "error initializing netlink socket\n");
1202                         log_error("error initializing netlink socket\n");
1203                         rc = 3;
1204                         goto exit;
1205                 }
1206                 fd_netlink = udev_monitor_get_fd(monitor);
1207         }
1208
1209         if (udev_monitor_enable_receiving(monitor) < 0) {
1210                 fprintf(stderr, "error binding netlink socket\n");
1211                 log_error("error binding netlink socket\n");
1212                 rc = 3;
1213                 goto exit;
1214         }
1215
1216         if (udev_ctrl_enable_receiving(udev_ctrl) < 0) {
1217                 fprintf(stderr, "error binding udev control socket\n");
1218                 log_error("error binding udev control socket\n");
1219                 rc = 1;
1220                 goto exit;
1221         }
1222
1223         udev_monitor_set_receive_buffer_size(monitor, 128*1024*1024);
1224
1225         /* create queue file before signalling 'ready', to make sure we block 'settle' */
1226         udev_queue_export = udev_queue_export_new(udev);
1227         if (udev_queue_export == NULL) {
1228                 log_error("error creating queue file\n");
1229                 goto exit;
1230         }
1231
1232         if (daemonize) {
1233                 pid_t pid;
1234                 int fd;
1235
1236                 pid = fork();
1237                 switch (pid) {
1238                 case 0:
1239                         break;
1240                 case -1:
1241                         log_error("fork of daemon failed: %m\n");
1242                         rc = 4;
1243                         goto exit;
1244                 default:
1245                         rc = EXIT_SUCCESS;
1246                         goto exit_daemonize;
1247                 }
1248
1249                 setsid();
1250
1251                 fd = open("/proc/self/oom_score_adj", O_RDWR|O_CLOEXEC);
1252                 if (fd >= 0) {
1253                         write(fd, "-1000", 5);
1254                         close(fd);
1255                 }
1256         } else {
1257                 sd_notify(1, "READY=1");
1258         }
1259
1260         f = fopen("/dev/kmsg", "w");
1261         if (f != NULL) {
1262                 fprintf(f, "<30>udevd[%u]: starting version " VERSION "\n", getpid());
1263                 fclose(f);
1264         }
1265
1266         if (!debug) {
1267                 int fd;
1268
1269                 fd = open("/dev/null", O_RDWR);
1270                 if (fd >= 0) {
1271                         dup2(fd, STDIN_FILENO);
1272                         dup2(fd, STDOUT_FILENO);
1273                         dup2(fd, STDERR_FILENO);
1274                         close(fd);
1275                 }
1276         }
1277
1278         fd_inotify = udev_watch_init(udev);
1279         if (fd_inotify < 0) {
1280                 fprintf(stderr, "error initializing inotify\n");
1281                 log_error("error initializing inotify\n");
1282                 rc = 4;
1283                 goto exit;
1284         }
1285         udev_watch_restore(udev);
1286
1287         /* block and listen to all signals on signalfd */
1288         sigfillset(&mask);
1289         sigprocmask(SIG_SETMASK, &mask, &sigmask_orig);
1290         fd_signal = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC);
1291         if (fd_signal < 0) {
1292                 fprintf(stderr, "error creating signalfd\n");
1293                 log_error("error creating signalfd\n");
1294                 rc = 5;
1295                 goto exit;
1296         }
1297
1298         /* unnamed socket from workers to the main daemon */
1299         if (socketpair(AF_LOCAL, SOCK_DGRAM|SOCK_CLOEXEC, 0, worker_watch) < 0) {
1300                 fprintf(stderr, "error creating socketpair\n");
1301                 log_error("error creating socketpair\n");
1302                 rc = 6;
1303                 goto exit;
1304         }
1305         fd_worker = worker_watch[READ_END];
1306
1307         udev_builtin_init(udev);
1308
1309         rules = udev_rules_new(udev, resolve_names);
1310         if (rules == NULL) {
1311                 log_error("error reading rules\n");
1312                 goto exit;
1313         }
1314
1315         memset(&ep_ctrl, 0, sizeof(struct epoll_event));
1316         ep_ctrl.events = EPOLLIN;
1317         ep_ctrl.data.fd = fd_ctrl;
1318
1319         memset(&ep_inotify, 0, sizeof(struct epoll_event));
1320         ep_inotify.events = EPOLLIN;
1321         ep_inotify.data.fd = fd_inotify;
1322
1323         memset(&ep_signal, 0, sizeof(struct epoll_event));
1324         ep_signal.events = EPOLLIN;
1325         ep_signal.data.fd = fd_signal;
1326
1327         memset(&ep_netlink, 0, sizeof(struct epoll_event));
1328         ep_netlink.events = EPOLLIN;
1329         ep_netlink.data.fd = fd_netlink;
1330
1331         memset(&ep_worker, 0, sizeof(struct epoll_event));
1332         ep_worker.events = EPOLLIN;
1333         ep_worker.data.fd = fd_worker;
1334
1335         fd_ep = epoll_create1(EPOLL_CLOEXEC);
1336         if (fd_ep < 0) {
1337                 log_error("error creating epoll fd: %m\n");
1338                 goto exit;
1339         }
1340         if (epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_ctrl, &ep_ctrl) < 0 ||
1341             epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_inotify, &ep_inotify) < 0 ||
1342             epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_signal, &ep_signal) < 0 ||
1343             epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_netlink, &ep_netlink) < 0 ||
1344             epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_worker, &ep_worker) < 0) {
1345                 log_error("fail to add fds to epoll: %m\n");
1346                 goto exit;
1347         }
1348
1349         /* if needed, convert old database from earlier udev version */
1350         convert_db(udev);
1351
1352         if (children_max <= 0) {
1353                 int memsize = mem_size_mb();
1354
1355                 /* set value depending on the amount of RAM */
1356                 if (memsize > 0)
1357                         children_max = 128 + (memsize / 8);
1358                 else
1359                         children_max = 128;
1360         }
1361         log_debug("set children_max to %u\n", children_max);
1362
1363         udev_rules_apply_static_dev_perms(rules);
1364
1365         udev_list_node_init(&event_list);
1366         udev_list_node_init(&worker_list);
1367
1368         for (;;) {
1369                 static unsigned long long last_usec;
1370                 struct epoll_event ev[8];
1371                 int fdcount;
1372                 int timeout;
1373                 bool is_worker, is_signal, is_inotify, is_netlink, is_ctrl;
1374                 int i;
1375
1376                 if (udev_exit) {
1377                         /* close sources of new events and discard buffered events */
1378                         if (fd_ctrl >= 0) {
1379                                 epoll_ctl(fd_ep, EPOLL_CTL_DEL, fd_ctrl, NULL);
1380                                 fd_ctrl = -1;
1381                         }
1382                         if (monitor != NULL) {
1383                                 epoll_ctl(fd_ep, EPOLL_CTL_DEL, fd_netlink, NULL);
1384                                 udev_monitor_unref(monitor);
1385                                 monitor = NULL;
1386                         }
1387                         if (fd_inotify >= 0) {
1388                                 epoll_ctl(fd_ep, EPOLL_CTL_DEL, fd_inotify, NULL);
1389                                 close(fd_inotify);
1390                                 fd_inotify = -1;
1391                         }
1392
1393                         /* discard queued events and kill workers */
1394                         event_queue_cleanup(udev, EVENT_QUEUED);
1395                         worker_kill(udev);
1396
1397                         /* exit after all has cleaned up */
1398                         if (udev_list_node_is_empty(&event_list) && udev_list_node_is_empty(&worker_list))
1399                                 break;
1400
1401                         /* timeout at exit for workers to finish */
1402                         timeout = 30 * 1000;
1403                 } else if (udev_list_node_is_empty(&event_list) && !children) {
1404                         /* we are idle */
1405                         timeout = -1;
1406
1407                         /* cleanup possible left-over processes in our cgroup */
1408                         if (udev_cgroup)
1409                                 cg_kill(SYSTEMD_CGROUP_CONTROLLER, udev_cgroup, SIGKILL, false, true, NULL);
1410                 } else {
1411                         /* kill idle or hanging workers */
1412                         timeout = 3 * 1000;
1413                 }
1414                 fdcount = epoll_wait(fd_ep, ev, ELEMENTSOF(ev), timeout);
1415                 if (fdcount < 0)
1416                         continue;
1417
1418                 if (fdcount == 0) {
1419                         struct udev_list_node *loop;
1420
1421                         /* timeout */
1422                         if (udev_exit) {
1423                                 log_error("timeout, giving up waiting for workers to finish\n");
1424                                 break;
1425                         }
1426
1427                         /* kill idle workers */
1428                         if (udev_list_node_is_empty(&event_list)) {
1429                                 log_debug("cleanup idle workers\n");
1430                                 worker_kill(udev);
1431                         }
1432
1433                         /* check for hanging events */
1434                         udev_list_node_foreach(loop, &worker_list) {
1435                                 struct worker *worker = node_to_worker(loop);
1436
1437                                 if (worker->state != WORKER_RUNNING)
1438                                         continue;
1439
1440                                 if ((now_usec() - worker->event_start_usec) > 30 * 1000 * 1000) {
1441                                         log_error("worker [%u] %s timeout; kill it\n", worker->pid,
1442                                             worker->event ? worker->event->devpath : "<idle>");
1443                                         kill(worker->pid, SIGKILL);
1444                                         worker->state = WORKER_KILLED;
1445                                         /* drop reference taken for state 'running' */
1446                                         worker_unref(worker);
1447                                         if (worker->event) {
1448                                                 log_error("seq %llu '%s' killed\n",
1449                                                           udev_device_get_seqnum(worker->event->dev), worker->event->devpath);
1450                                                 worker->event->exitcode = -64;
1451                                                 event_queue_delete(worker->event, true);
1452                                                 worker->event = NULL;
1453                                         }
1454                                 }
1455                         }
1456
1457                 }
1458
1459                 is_worker = is_signal = is_inotify = is_netlink = is_ctrl = false;
1460                 for (i = 0; i < fdcount; i++) {
1461                         if (ev[i].data.fd == fd_worker && ev[i].events & EPOLLIN)
1462                                 is_worker = true;
1463                         else if (ev[i].data.fd == fd_netlink && ev[i].events & EPOLLIN)
1464                                 is_netlink = true;
1465                         else if (ev[i].data.fd == fd_signal && ev[i].events & EPOLLIN)
1466                                 is_signal = true;
1467                         else if (ev[i].data.fd == fd_inotify && ev[i].events & EPOLLIN)
1468                                 is_inotify = true;
1469                         else if (ev[i].data.fd == fd_ctrl && ev[i].events & EPOLLIN)
1470                                 is_ctrl = true;
1471                 }
1472
1473                 /* check for changed config, every 3 seconds at most */
1474                 if ((now_usec() - last_usec) > 3 * 1000 * 1000) {
1475                         if (udev_rules_check_timestamp(rules))
1476                                 reload = true;
1477                         if (udev_builtin_validate(udev))
1478                                 reload = true;
1479
1480                         last_usec = now_usec();
1481                 }
1482
1483                 /* reload requested, HUP signal received, rules changed, builtin changed */
1484                 if (reload) {
1485                         worker_kill(udev);
1486                         rules = udev_rules_unref(rules);
1487                         udev_builtin_exit(udev);
1488                         reload = 0;
1489                 }
1490
1491                 /* event has finished */
1492                 if (is_worker)
1493                         worker_returned(fd_worker);
1494
1495                 if (is_netlink) {
1496                         struct udev_device *dev;
1497
1498                         dev = udev_monitor_receive_device(monitor);
1499                         if (dev != NULL) {
1500                                 udev_device_set_usec_initialized(dev, now_usec());
1501                                 if (event_queue_insert(dev) < 0)
1502                                         udev_device_unref(dev);
1503                         }
1504                 }
1505
1506                 /* start new events */
1507                 if (!udev_list_node_is_empty(&event_list) && !udev_exit && !stop_exec_queue) {
1508                         if (rules == NULL)
1509                                 rules = udev_rules_new(udev, resolve_names);
1510                         if (rules != NULL)
1511                                 event_queue_start(udev);
1512                 }
1513
1514                 if (is_signal) {
1515                         struct signalfd_siginfo fdsi;
1516                         ssize_t size;
1517
1518                         size = read(fd_signal, &fdsi, sizeof(struct signalfd_siginfo));
1519                         if (size == sizeof(struct signalfd_siginfo))
1520                                 handle_signal(udev, fdsi.ssi_signo);
1521                 }
1522
1523                 /* we are shutting down, the events below are not handled anymore */
1524                 if (udev_exit)
1525                         continue;
1526
1527                 /* device node watch */
1528                 if (is_inotify)
1529                         handle_inotify(udev);
1530
1531                 /*
1532                  * This needs to be after the inotify handling, to make sure,
1533                  * that the ping is send back after the possibly generated
1534                  * "change" events by the inotify device node watch.
1535                  *
1536                  * A single time we may receive a client connection which we need to
1537                  * keep open to block the client. It will be closed right before we
1538                  * exit.
1539                  */
1540                 if (is_ctrl)
1541                         ctrl_conn = handle_ctrl_msg(udev_ctrl);
1542         }
1543
1544         rc = EXIT_SUCCESS;
1545 exit:
1546         udev_queue_export_cleanup(udev_queue_export);
1547         udev_ctrl_cleanup(udev_ctrl);
1548 exit_daemonize:
1549         if (fd_ep >= 0)
1550                 close(fd_ep);
1551         worker_list_cleanup(udev);
1552         event_queue_cleanup(udev, EVENT_UNDEF);
1553         udev_rules_unref(rules);
1554         udev_builtin_exit(udev);
1555         if (fd_signal >= 0)
1556                 close(fd_signal);
1557         if (worker_watch[READ_END] >= 0)
1558                 close(worker_watch[READ_END]);
1559         if (worker_watch[WRITE_END] >= 0)
1560                 close(worker_watch[WRITE_END]);
1561         udev_monitor_unref(monitor);
1562         udev_queue_export_unref(udev_queue_export);
1563         udev_ctrl_connection_unref(ctrl_conn);
1564         udev_ctrl_unref(udev_ctrl);
1565         label_finish();
1566         udev_unref(udev);
1567         log_close();
1568         return rc;
1569 }