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 struct event *node_to_event(struct udev_list_node *node)
 103 {
 104         char *event;
 105
 106         event = (char *)node;
 107         event -= offsetof(struct event, node);
 108         return (struct event *)event;
 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         unsigned long long 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 struct worker *node_to_worker(struct udev_list_node *node)
 138 {
 139         char *worker;
 140
 141         worker = (char *)node;
 142         worker -= offsetof(struct worker, node);
 143         return (struct worker *)worker;
 144 }
 145
 146 static void event_queue_delete(struct event *event, bool export)
 147 {
 148         udev_list_node_remove(&event->node);
 149
 150         if (export) {
 151                 udev_queue_export_device_finished(udev_queue_export, event->dev);
 152                 log_debug("seq %llu done with %i\n", udev_device_get_seqnum(event->dev), event->exitcode);
 153         }
 154         udev_device_unref(event->dev);
 155         free(event);
 156 }
 157
 158 static struct worker *worker_ref(struct worker *worker)
 159 {
 160         worker->refcount++;
 161         return worker;
 162 }
 163
 164 static void worker_cleanup(struct worker *worker)
 165 {
 166         udev_list_node_remove(&worker->node);
 167         udev_monitor_unref(worker->monitor);
 168         children--;
 169         free(worker);
 170 }
 171
 172 static void worker_unref(struct worker *worker)
 173 {
 174         worker->refcount--;
 175         if (worker->refcount > 0)
 176                 return;
 177         log_debug("worker [%u] cleaned up\n", worker->pid);
 178         worker_cleanup(worker);
 179 }
 180
 181 static void worker_list_cleanup(struct udev *udev)
 182 {
 183         struct udev_list_node *loop, *tmp;
 184
 185         udev_list_node_foreach_safe(loop, tmp, &worker_list) {
 186                 struct worker *worker = node_to_worker(loop);
 187
 188                 worker_cleanup(worker);
 189         }
 190 }
 191
 192 static void worker_new(struct event *event)
 193 {
 194         struct udev *udev = event->udev;
 195         struct worker *worker;
 196         struct udev_monitor *worker_monitor;
 197         pid_t pid;
 198
 199         /* listen for new events */
 200         worker_monitor = udev_monitor_new_from_netlink(udev, NULL);
 201         if (worker_monitor == NULL)
 202                 return;
 203         /* allow the main daemon netlink address to send devices to the worker */
 204         udev_monitor_allow_unicast_sender(worker_monitor, monitor);
 205         udev_monitor_enable_receiving(worker_monitor);
 206
 207         worker = calloc(1, sizeof(struct worker));
 208         if (worker == NULL) {
 209                 udev_monitor_unref(worker_monitor);
 210                 return;
 211         }
 212         /* worker + event reference */
 213         worker->refcount = 2;
 214         worker->udev = udev;
 215
 216         pid = fork();
 217         switch (pid) {
 218         case 0: {
 219                 struct udev_device *dev = NULL;
 220                 int fd_monitor;
 221                 struct epoll_event ep_signal, ep_monitor;
 222                 sigset_t mask;
 223                 int rc = EXIT_SUCCESS;
 224
 225                 /* take initial device from queue */
 226                 dev = event->dev;
 227                 event->dev = NULL;
 228
 229                 free(worker);
 230                 worker_list_cleanup(udev);
 231                 event_queue_cleanup(udev, EVENT_UNDEF);
 232                 udev_queue_export_unref(udev_queue_export);
 233                 udev_monitor_unref(monitor);
 234                 udev_ctrl_unref(udev_ctrl);
 235                 close(fd_signal);
 236                 close(fd_ep);
 237                 close(worker_watch[READ_END]);
 238
 239                 sigfillset(&mask);
 240                 fd_signal = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC);
 241                 if (fd_signal < 0) {
 242                         log_error("error creating signalfd %m\n");
 243                         rc = 2;
 244                         goto out;
 245                 }
 246
 247                 fd_ep = epoll_create1(EPOLL_CLOEXEC);
 248                 if (fd_ep < 0) {
 249                         log_error("error creating epoll fd: %m\n");
 250                         rc = 3;
 251                         goto out;
 252                 }
 253
 254                 memset(&ep_signal, 0, sizeof(struct epoll_event));
 255                 ep_signal.events = EPOLLIN;
 256                 ep_signal.data.fd = fd_signal;
 257
 258                 fd_monitor = udev_monitor_get_fd(worker_monitor);
 259                 memset(&ep_monitor, 0, sizeof(struct epoll_event));
 260                 ep_monitor.events = EPOLLIN;
 261                 ep_monitor.data.fd = fd_monitor;
 262
 263                 if (epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_signal, &ep_signal) < 0 ||
 264                     epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_monitor, &ep_monitor) < 0) {
 265                         log_error("fail to add fds to epoll: %m\n");
 266                         rc = 4;
 267                         goto out;
 268                 }
 269
 270                 /* request TERM signal if parent exits */
 271                 prctl(PR_SET_PDEATHSIG, SIGTERM);
 272
 273                 for (;;) {
 274                         struct udev_event *udev_event;
 275                         struct worker_message msg;
 276                         int err;
 277
 278                         log_debug("seq %llu running\n", udev_device_get_seqnum(dev));
 279                         udev_event = udev_event_new(dev);
 280                         if (udev_event == NULL) {
 281                                 rc = 5;
 282                                 goto out;
 283                         }
 284
 285                         /* needed for SIGCHLD/SIGTERM in spawn() */
 286                         udev_event->fd_signal = fd_signal;
 287
 288                         if (exec_delay > 0)
 289                                 udev_event->exec_delay = exec_delay;
 290
 291                         /* apply rules, create node, symlinks */
 292                         err = udev_event_execute_rules(udev_event, rules, &sigmask_orig);
 293
 294                         if (err == 0)
 295                                 udev_event_execute_run(udev_event, &sigmask_orig);
 296
 297                         /* apply/restore inotify watch */
 298                         if (err == 0 && udev_event->inotify_watch) {
 299                                 udev_watch_begin(udev, dev);
 300                                 udev_device_update_db(dev);
 301                         }
 302
 303                         /* send processed event back to libudev listeners */
 304                         udev_monitor_send_device(worker_monitor, NULL, dev);
 305
 306                         /* send udevd the result of the event execution */
 307                         memset(&msg, 0, sizeof(struct worker_message));
 308                         if (err != 0)
 309                                 msg.exitcode = err;
 310                         msg.pid = getpid();
 311                         send(worker_watch[WRITE_END], &msg, sizeof(struct worker_message), 0);
 312
 313                         log_debug("seq %llu processed with %i\n", udev_device_get_seqnum(dev), err);
 314
 315                         udev_device_unref(dev);
 316                         dev = NULL;
 317
 318                         if (udev_event->sigterm) {
 319                                 udev_event_unref(udev_event);
 320                                 goto out;
 321                         }
 322
 323                         udev_event_unref(udev_event);
 324
 325                         /* wait for more device messages from main udevd, or term signal */
 326                         while (dev == NULL) {
 327                                 struct epoll_event ev[4];
 328                                 int fdcount;
 329                                 int i;
 330
 331                                 fdcount = epoll_wait(fd_ep, ev, ELEMENTSOF(ev), -1);
 332                                 if (fdcount < 0) {
 333                                         if (errno == EINTR)
 334                                                 continue;
 335                                         log_error("failed to poll: %m\n");
 336                                         goto out;
 337                                 }
 338
 339                                 for (i = 0; i < fdcount; i++) {
 340                                         if (ev[i].data.fd == fd_monitor && ev[i].events & EPOLLIN) {
 341                                                 dev = udev_monitor_receive_device(worker_monitor);
 342                                                 break;
 343                                         } else if (ev[i].data.fd == fd_signal && ev[i].events & EPOLLIN) {
 344                                                 struct signalfd_siginfo fdsi;
 345                                                 ssize_t size;
 346
 347                                                 size = read(fd_signal, &fdsi, sizeof(struct signalfd_siginfo));
 348                                                 if (size != sizeof(struct signalfd_siginfo))
 349                                                         continue;
 350                                                 switch (fdsi.ssi_signo) {
 351                                                 case SIGTERM:
 352                                                         goto out;
 353                                                 }
 354                                         }
 355                                 }
 356                         }
 357                 }
 358 out:
 359                 udev_device_unref(dev);
 360                 if (fd_signal >= 0)
 361                         close(fd_signal);
 362                 if (fd_ep >= 0)
 363                         close(fd_ep);
 364                 close(fd_inotify);
 365                 close(worker_watch[WRITE_END]);
 366                 udev_rules_unref(rules);
 367                 udev_builtin_exit(udev);
 368                 udev_monitor_unref(worker_monitor);
 369                 udev_unref(udev);
 370                 log_close();
 371                 exit(rc);
 372         }
 373         case -1:
 374                 udev_monitor_unref(worker_monitor);
 375                 event->state = EVENT_QUEUED;
 376                 free(worker);
 377                 log_error("fork of child failed: %m\n");
 378                 break;
 379         default:
 380                 /* close monitor, but keep address around */
 381                 udev_monitor_disconnect(worker_monitor);
 382                 worker->monitor = worker_monitor;
 383                 worker->pid = pid;
 384                 worker->state = WORKER_RUNNING;
 385                 worker->event_start_usec = now_usec();
 386                 worker->event = event;
 387                 event->state = EVENT_RUNNING;
 388                 udev_list_node_append(&worker->node, &worker_list);
 389                 children++;
 390                 log_debug("seq %llu forked new worker [%u]\n", udev_device_get_seqnum(event->dev), pid);
 391                 break;
 392         }
 393 }
 394
 395 static void event_run(struct event *event)
 396 {
 397         struct udev_list_node *loop;
 398
 399         udev_list_node_foreach(loop, &worker_list) {
 400                 struct worker *worker = node_to_worker(loop);
 401                 ssize_t count;
 402
 403                 if (worker->state != WORKER_IDLE)
 404                         continue;
 405
 406                 count = udev_monitor_send_device(monitor, worker->monitor, event->dev);
 407                 if (count < 0) {
 408                         log_error("worker [%u] did not accept message %zi (%m), kill it\n", worker->pid, count);
 409                         kill(worker->pid, SIGKILL);
 410                         worker->state = WORKER_KILLED;
 411                         continue;
 412                 }
 413                 worker_ref(worker);
 414                 worker->event = event;
 415                 worker->state = WORKER_RUNNING;
 416                 worker->event_start_usec = now_usec();
 417                 event->state = EVENT_RUNNING;
 418                 return;
 419         }
 420
 421         if (children >= children_max) {
 422                 if (children_max > 1)
 423                         log_debug("maximum number (%i) of children reached\n", children);
 424                 return;
 425         }
 426
 427         /* start new worker and pass initial device */
 428         worker_new(event);
 429 }
 430
 431 static int event_queue_insert(struct udev_device *dev)
 432 {
 433         struct event *event;
 434
 435         event = calloc(1, sizeof(struct event));
 436         if (event == NULL)
 437                 return -1;
 438
 439         event->udev = udev_device_get_udev(dev);
 440         event->dev = dev;
 441         event->seqnum = udev_device_get_seqnum(dev);
 442         event->devpath = udev_device_get_devpath(dev);
 443         event->devpath_len = strlen(event->devpath);
 444         event->devpath_old = udev_device_get_devpath_old(dev);
 445         event->devnum = udev_device_get_devnum(dev);
 446         event->is_block = (strcmp("block", udev_device_get_subsystem(dev)) == 0);
 447         event->ifindex = udev_device_get_ifindex(dev);
 448
 449         udev_queue_export_device_queued(udev_queue_export, dev);
 450         log_debug("seq %llu queued, '%s' '%s'\n", udev_device_get_seqnum(dev),
 451              udev_device_get_action(dev), udev_device_get_subsystem(dev));
 452
 453         event->state = EVENT_QUEUED;
 454         udev_list_node_append(&event->node, &event_list);
 455         return 0;
 456 }
 457
 458 static void worker_kill(struct udev *udev)
 459 {
 460         struct udev_list_node *loop;
 461
 462         udev_list_node_foreach(loop, &worker_list) {
 463                 struct worker *worker = node_to_worker(loop);
 464
 465                 if (worker->state == WORKER_KILLED)
 466                         continue;
 467
 468                 worker->state = WORKER_KILLED;
 469                 kill(worker->pid, SIGTERM);
 470         }
 471 }
 472
 473 /* lookup event for identical, parent, child device */
 474 static bool is_devpath_busy(struct event *event)
 475 {
 476         struct udev_list_node *loop;
 477         size_t common;
 478
 479         /* check if queue contains events we depend on */
 480         udev_list_node_foreach(loop, &event_list) {
 481                 struct event *loop_event = node_to_event(loop);
 482
 483                 /* we already found a later event, earlier can not block us, no need to check again */
 484                 if (loop_event->seqnum < event->delaying_seqnum)
 485                         continue;
 486
 487                 /* event we checked earlier still exists, no need to check again */
 488                 if (loop_event->seqnum == event->delaying_seqnum)
 489                         return true;
 490
 491                 /* found ourself, no later event can block us */
 492                 if (loop_event->seqnum >= event->seqnum)
 493                         break;
 494
 495                 /* check major/minor */
 496                 if (major(event->devnum) != 0 && event->devnum == loop_event->devnum && event->is_block == loop_event->is_block)
 497                         return true;
 498
 499                 /* check network device ifindex */
 500                 if (event->ifindex != 0 && event->ifindex == loop_event->ifindex)
 501                         return true;
 502
 503                 /* check our old name */
 504                 if (event->devpath_old != NULL && strcmp(loop_event->devpath, event->devpath_old) == 0) {
 505                         event->delaying_seqnum = loop_event->seqnum;
 506                         return true;
 507                 }
 508
 509                 /* compare devpath */
 510                 common = MIN(loop_event->devpath_len, event->devpath_len);
 511
 512                 /* one devpath is contained in the other? */
 513                 if (memcmp(loop_event->devpath, event->devpath, common) != 0)
 514                         continue;
 515
 516                 /* identical device event found */
 517                 if (loop_event->devpath_len == event->devpath_len) {
 518                         /* devices names might have changed/swapped in the meantime */
 519                         if (major(event->devnum) != 0 && (event->devnum != loop_event->devnum || event->is_block != loop_event->is_block))
 520                                 continue;
 521                         if (event->ifindex != 0 && event->ifindex != loop_event->ifindex)
 522                                 continue;
 523                         event->delaying_seqnum = loop_event->seqnum;
 524                         return true;
 525                 }
 526
 527                 /* parent device event found */
 528                 if (event->devpath[common] == '/') {
 529                         event->delaying_seqnum = loop_event->seqnum;
 530                         return true;
 531                 }
 532
 533                 /* child device event found */
 534                 if (loop_event->devpath[common] == '/') {
 535                         event->delaying_seqnum = loop_event->seqnum;
 536                         return true;
 537                 }
 538
 539                 /* no matching device */
 540                 continue;
 541         }
 542
 543         return false;
 544 }
 545
 546 static void event_queue_start(struct udev *udev)
 547 {
 548         struct udev_list_node *loop;
 549
 550         udev_list_node_foreach(loop, &event_list) {
 551                 struct event *event = node_to_event(loop);
 552
 553                 if (event->state != EVENT_QUEUED)
 554                         continue;
 555
 556                 /* do not start event if parent or child event is still running */
 557                 if (is_devpath_busy(event))
 558                         continue;
 559
 560                 event_run(event);
 561         }
 562 }
 563
 564 static void event_queue_cleanup(struct udev *udev, enum event_state match_type)
 565 {
 566         struct udev_list_node *loop, *tmp;
 567
 568         udev_list_node_foreach_safe(loop, tmp, &event_list) {
 569                 struct event *event = node_to_event(loop);
 570
 571                 if (match_type != EVENT_UNDEF && match_type != event->state)
 572                         continue;
 573
 574                 event_queue_delete(event, false);
 575         }
 576 }
 577
 578 static void worker_returned(int fd_worker)
 579 {
 580         for (;;) {
 581                 struct worker_message msg;
 582                 ssize_t size;
 583                 struct udev_list_node *loop;
 584
 585                 size = recv(fd_worker, &msg, sizeof(struct worker_message), MSG_DONTWAIT);
 586                 if (size != sizeof(struct worker_message))
 587                         break;
 588
 589                 /* lookup worker who sent the signal */
 590                 udev_list_node_foreach(loop, &worker_list) {
 591                         struct worker *worker = node_to_worker(loop);
 592
 593                         if (worker->pid != msg.pid)
 594                                 continue;
 595
 596                         /* worker returned */
 597                         if (worker->event) {
 598                                 worker->event->exitcode = msg.exitcode;
 599                                 event_queue_delete(worker->event, true);
 600                                 worker->event = NULL;
 601                         }
 602                         if (worker->state != WORKER_KILLED)
 603                                 worker->state = WORKER_IDLE;
 604                         worker_unref(worker);
 605                         break;
 606                 }
 607         }
 608 }
 609
 610 /* receive the udevd message from userspace */
 611 static struct udev_ctrl_connection *handle_ctrl_msg(struct udev_ctrl *uctrl)
 612 {
 613         struct udev *udev = udev_ctrl_get_udev(uctrl);
 614         struct udev_ctrl_connection *ctrl_conn;
 615         struct udev_ctrl_msg *ctrl_msg = NULL;
 616         const char *str;
 617         int i;
 618
 619         ctrl_conn = udev_ctrl_get_connection(uctrl);
 620         if (ctrl_conn == NULL)
 621                 goto out;
 622
 623         ctrl_msg = udev_ctrl_receive_msg(ctrl_conn);
 624         if (ctrl_msg == NULL)
 625                 goto out;
 626
 627         i = udev_ctrl_get_set_log_level(ctrl_msg);
 628         if (i >= 0) {
 629                 log_debug("udevd message (SET_LOG_PRIORITY) received, log_priority=%i\n", i);
 630                 log_set_max_level(i);
 631                 udev_set_log_priority(udev, i);
 632                 worker_kill(udev);
 633         }
 634
 635         if (udev_ctrl_get_stop_exec_queue(ctrl_msg) > 0) {
 636                 log_debug("udevd message (STOP_EXEC_QUEUE) received\n");
 637                 stop_exec_queue = true;
 638         }
 639
 640         if (udev_ctrl_get_start_exec_queue(ctrl_msg) > 0) {
 641                 log_debug("udevd message (START_EXEC_QUEUE) received\n");
 642                 stop_exec_queue = false;
 643         }
 644
 645         if (udev_ctrl_get_reload(ctrl_msg) > 0) {
 646                 log_debug("udevd message (RELOAD) received\n");
 647                 reload = true;
 648         }
 649
 650         str = udev_ctrl_get_set_env(ctrl_msg);
 651         if (str != NULL) {
 652                 char *key;
 653
 654                 key = strdup(str);
 655                 if (key != NULL) {
 656                         char *val;
 657
 658                         val = strchr(key, '=');
 659                         if (val != NULL) {
 660                                 val[0] = '\0';
 661                                 val = &val[1];
 662                                 if (val[0] == '\0') {
 663                                         log_debug("udevd message (ENV) received, unset '%s'\n", key);
 664                                         udev_add_property(udev, key, NULL);
 665                                 } else {
 666                                         log_debug("udevd message (ENV) received, set '%s=%s'\n", key, val);
 667                                         udev_add_property(udev, key, val);
 668                                 }
 669                         } else {
 670                                 log_error("wrong key format '%s'\n", key);
 671                         }
 672                         free(key);
 673                 }
 674                 worker_kill(udev);
 675         }
 676
 677         i = udev_ctrl_get_set_children_max(ctrl_msg);
 678         if (i >= 0) {
 679                 log_debug("udevd message (SET_MAX_CHILDREN) received, children_max=%i\n", i);
 680                 children_max = i;
 681         }
 682
 683         if (udev_ctrl_get_ping(ctrl_msg) > 0)
 684                 log_debug("udevd message (SYNC) received\n");
 685
 686         if (udev_ctrl_get_exit(ctrl_msg) > 0) {
 687                 log_debug("udevd message (EXIT) received\n");
 688                 udev_exit = true;
 689                 /* keep reference to block the client until we exit */
 690                 udev_ctrl_connection_ref(ctrl_conn);
 691         }
 692 out:
 693         udev_ctrl_msg_unref(ctrl_msg);
 694         return udev_ctrl_connection_unref(ctrl_conn);
 695 }
 696
 697 /* read inotify messages */
 698 static int handle_inotify(struct udev *udev)
 699 {
 700         int nbytes, pos;
 701         char *buf;
 702         struct inotify_event *ev;
 703
 704         if ((ioctl(fd_inotify, FIONREAD, &nbytes) < 0) || (nbytes <= 0))
 705                 return 0;
 706
 707         buf = malloc(nbytes);
 708         if (buf == NULL) {
 709                 log_error("error getting buffer for inotify\n");
 710                 return -1;
 711         }
 712
 713         nbytes = read(fd_inotify, buf, nbytes);
 714
 715         for (pos = 0; pos < nbytes; pos += sizeof(struct inotify_event) + ev->len) {
 716                 struct udev_device *dev;
 717
 718                 ev = (struct inotify_event *)(buf + pos);
 719                 dev = udev_watch_lookup(udev, ev->wd);
 720                 if (dev != NULL) {
 721                         log_debug("inotify event: %x for %s\n", ev->mask, udev_device_get_devnode(dev));
 722                         if (ev->mask & IN_CLOSE_WRITE) {
 723                                 char filename[UTIL_PATH_SIZE];
 724                                 int fd;
 725
 726                                 log_debug("device %s closed, synthesising 'change'\n", udev_device_get_devnode(dev));
 727                                 util_strscpyl(filename, sizeof(filename), udev_device_get_syspath(dev), "/uevent", NULL);
 728                                 fd = open(filename, O_WRONLY);
 729                                 if (fd >= 0) {
 730                                         if (write(fd, "change", 6) < 0)
 731                                                 log_debug("error writing uevent: %m\n");
 732                                         close(fd);
 733                                 }
 734                         }
 735                         if (ev->mask & IN_IGNORED)
 736                                 udev_watch_end(udev, dev);
 737
 738                         udev_device_unref(dev);
 739                 }
 740
 741         }
 742
 743         free(buf);
 744         return 0;
 745 }
 746
 747 static void handle_signal(struct udev *udev, int signo)
 748 {
 749         switch (signo) {
 750         case SIGINT:
 751         case SIGTERM:
 752                 udev_exit = true;
 753                 break;
 754         case SIGCHLD:
 755                 for (;;) {
 756                         pid_t pid;
 757                         int status;
 758                         struct udev_list_node *loop, *tmp;
 759
 760                         pid = waitpid(-1, &status, WNOHANG);
 761                         if (pid <= 0)
 762                                 break;
 763
 764                         udev_list_node_foreach_safe(loop, tmp, &worker_list) {
 765                                 struct worker *worker = node_to_worker(loop);
 766
 767                                 if (worker->pid != pid)
 768                                         continue;
 769                                 log_debug("worker [%u] exit\n", pid);
 770
 771                                 if (WIFEXITED(status)) {
 772                                         if (WEXITSTATUS(status) != 0)
 773                                                 log_error("worker [%u] exit with return code %i\n", pid, WEXITSTATUS(status));
 774                                 } else if (WIFSIGNALED(status)) {
 775                                         log_error("worker [%u] terminated by signal %i (%s)\n",
 776                                             pid, WTERMSIG(status), strsignal(WTERMSIG(status)));
 777                                 } else if (WIFSTOPPED(status)) {
 778                                         log_error("worker [%u] stopped\n", pid);
 779                                 } else if (WIFCONTINUED(status)) {
 780                                         log_error("worker [%u] continued\n", pid);
 781                                 } else {
 782                                         log_error("worker [%u] exit with status 0x%04x\n", pid, status);
 783                                 }
 784
 785                                 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
 786                                         if (worker->event) {
 787                                                 log_error("worker [%u] failed while handling '%s'\n",
 788                                                           pid, worker->event->devpath);
 789                                                 worker->event->exitcode = -32;
 790                                                 event_queue_delete(worker->event, true);
 791                                                 /* drop reference taken for state 'running' */
 792                                                 worker_unref(worker);
 793                                         }
 794                                 }
 795                                 worker_unref(worker);
 796                                 break;
 797                         }
 798                 }
 799                 break;
 800         case SIGHUP:
 801                 reload = true;
 802                 break;
 803         }
 804 }
 805
 806 static void static_dev_create_from_modules(struct udev *udev)
 807 {
 808         struct utsname kernel;
 809         char modules[UTIL_PATH_SIZE];
 810         char buf[4096];
 811         FILE *f;
 812
 813         uname(&kernel);
 814         util_strscpyl(modules, sizeof(modules), "/lib/modules/", kernel.release, "/modules.devname", NULL);
 815         f = fopen(modules, "r");
 816         if (f == NULL)
 817                 return;
 818
 819         while (fgets(buf, sizeof(buf), f) != NULL) {
 820                 char *s;
 821                 const char *modname;
 822                 const char *devname;
 823                 const char *devno;
 824                 int maj, min;
 825                 char type;
 826                 mode_t mode;
 827                 char filename[UTIL_PATH_SIZE];
 828
 829                 if (buf[0] == '#')
 830                         continue;
 831
 832                 modname = buf;
 833                 s = strchr(modname, ' ');
 834                 if (s == NULL)
 835                         continue;
 836                 s[0] = '\0';
 837
 838                 devname = &s[1];
 839                 s = strchr(devname, ' ');
 840                 if (s == NULL)
 841                         continue;
 842                 s[0] = '\0';
 843
 844                 devno = &s[1];
 845                 s = strchr(devno, ' ');
 846                 if (s == NULL)
 847                         s = strchr(devno, '\n');
 848                 if (s != NULL)
 849                         s[0] = '\0';
 850                 if (sscanf(devno, "%c%u:%u", &type, &maj, &min) != 3)
 851                         continue;
 852
 853                 if (type == 'c')
 854                         mode = S_IFCHR;
 855                 else if (type == 'b')
 856                         mode = S_IFBLK;
 857                 else
 858                         continue;
 859
 860                 util_strscpyl(filename, sizeof(filename), "/dev/", devname, NULL);
 861                 mkdir_parents(filename, 0755);
 862                 label_context_set(filename, mode);
 863                 log_debug("mknod '%s' %c%u:%u\n", filename, type, maj, min);
 864                 if (mknod(filename, mode, makedev(maj, min)) < 0 && errno == EEXIST)
 865                         utimensat(AT_FDCWD, filename, NULL, 0);
 866                 label_context_clear();
 867         }
 868
 869         fclose(f);
 870 }
 871
 872 static int mem_size_mb(void)
 873 {
 874         FILE *f;
 875         char buf[4096];
 876         long int memsize = -1;
 877
 878         f = fopen("/proc/meminfo", "r");
 879         if (f == NULL)
 880                 return -1;
 881
 882         while (fgets(buf, sizeof(buf), f) != NULL) {
 883                 long int value;
 884
 885                 if (sscanf(buf, "MemTotal: %ld kB", &value) == 1) {
 886                         memsize = value / 1024;
 887                         break;
 888                 }
 889         }
 890
 891         fclose(f);
 892         return memsize;
 893 }
 894
 895 static int convert_db(struct udev *udev)
 896 {
 897         char filename[UTIL_PATH_SIZE];
 898         FILE *f;
 899         struct udev_enumerate *udev_enumerate;
 900         struct udev_list_entry *list_entry;
 901
 902         /* current database */
 903         if (access("/run/udev/data", F_OK) >= 0)
 904                 return 0;
 905
 906         /* make sure we do not get here again */
 907         mkdir_parents("/run/udev/data", 0755);
 908         mkdir(filename, 0755);
 909
 910         /* old database */
 911         util_strscpyl(filename, sizeof(filename), "/dev/.udev/db", NULL);
 912         if (access(filename, F_OK) < 0)
 913                 return 0;
 914
 915         f = fopen("/dev/kmsg", "w");
 916         if (f != NULL) {
 917                 fprintf(f, "<30>udevd[%u]: converting old udev database\n", getpid());
 918                 fclose(f);
 919         }
 920
 921         udev_enumerate = udev_enumerate_new(udev);
 922         if (udev_enumerate == NULL)
 923                 return -1;
 924         udev_enumerate_scan_devices(udev_enumerate);
 925         udev_list_entry_foreach(list_entry, udev_enumerate_get_list_entry(udev_enumerate)) {
 926                 struct udev_device *device;
 927
 928                 device = udev_device_new_from_syspath(udev, udev_list_entry_get_name(list_entry));
 929                 if (device == NULL)
 930                         continue;
 931
 932                 /* try to find the old database for devices without a current one */
 933                 if (udev_device_read_db(device, NULL) < 0) {
 934                         bool have_db;
 935                         const char *id;
 936                         struct stat stats;
 937                         char devpath[UTIL_PATH_SIZE];
 938                         char from[UTIL_PATH_SIZE];
 939
 940                         have_db = false;
 941
 942                         /* find database in old location */
 943                         id = udev_device_get_id_filename(device);
 944                         util_strscpyl(from, sizeof(from), "/dev/.udev/db/", id, NULL);
 945                         if (lstat(from, &stats) == 0) {
 946                                 if (!have_db) {
 947                                         udev_device_read_db(device, from);
 948                                         have_db = true;
 949                                 }
 950                                 unlink(from);
 951                         }
 952
 953                         /* find old database with $subsys:$sysname name */
 954                         util_strscpyl(from, sizeof(from), "/dev/.udev/db/",
 955                                       udev_device_get_subsystem(device), ":", udev_device_get_sysname(device), NULL);
 956                         if (lstat(from, &stats) == 0) {
 957                                 if (!have_db) {
 958                                         udev_device_read_db(device, from);
 959                                         have_db = true;
 960                                 }
 961                                 unlink(from);
 962                         }
 963
 964                         /* find old database with the encoded devpath name */
 965                         util_path_encode(udev_device_get_devpath(device), devpath, sizeof(devpath));
 966                         util_strscpyl(from, sizeof(from), "/dev/.udev/db/", devpath, NULL);
 967                         if (lstat(from, &stats) == 0) {
 968                                 if (!have_db) {
 969                                         udev_device_read_db(device, from);
 970                                         have_db = true;
 971                                 }
 972                                 unlink(from);
 973                         }
 974
 975                         /* write out new database */
 976                         if (have_db)
 977                                 udev_device_update_db(device);
 978                 }
 979                 udev_device_unref(device);
 980         }
 981         udev_enumerate_unref(udev_enumerate);
 982         return 0;
 983 }
 984
 985 static int systemd_fds(struct udev *udev, int *rctrl, int *rnetlink)
 986 {
 987         int ctrl = -1, netlink = -1;
 988         int fd, n;
 989
 990         n = sd_listen_fds(true);
 991         if (n <= 0)
 992                 return -1;
 993
 994         for (fd = SD_LISTEN_FDS_START; fd < n + SD_LISTEN_FDS_START; fd++) {
 995                 if (sd_is_socket(fd, AF_LOCAL, SOCK_SEQPACKET, -1)) {
 996                         if (ctrl >= 0)
 997                                 return -1;
 998                         ctrl = fd;
 999                         continue;
1000                 }
1001
1002                 if (sd_is_socket(fd, AF_NETLINK, SOCK_RAW, -1)) {
1003                         if (netlink >= 0)
1004                                 return -1;
1005                         netlink = fd;
1006                         continue;
1007                 }
1008
1009                 return -1;
1010         }
1011
1012         if (ctrl < 0 || netlink < 0)
1013                 return -1;
1014
1015         log_debug("ctrl=%i netlink=%i\n", ctrl, netlink);
1016         *rctrl = ctrl;
1017         *rnetlink = netlink;
1018         return 0;
1019 }
1020
1021 int main(int argc, char *argv[])
1022 {
1023         struct udev *udev;
1024         FILE *f;
1025         sigset_t mask;
1026         int daemonize = false;
1027         int resolve_names = 1;
1028         static const struct option options[] = {
1029                 { "daemon", no_argument, NULL, 'd' },
1030                 { "debug", no_argument, NULL, 'D' },
1031                 { "children-max", required_argument, NULL, 'c' },
1032                 { "exec-delay", required_argument, NULL, 'e' },
1033                 { "resolve-names", required_argument, NULL, 'N' },
1034                 { "help", no_argument, NULL, 'h' },
1035                 { "version", no_argument, NULL, 'V' },
1036                 {}
1037         };
1038         int fd_ctrl = -1;
1039         int fd_netlink = -1;
1040         int fd_worker = -1;
1041         struct epoll_event ep_ctrl, ep_inotify, ep_signal, ep_netlink, ep_worker;
1042         struct udev_ctrl_connection *ctrl_conn = NULL;
1043         int rc = 1;
1044
1045         udev = udev_new();
1046         if (udev == NULL)
1047                 goto exit;
1048
1049         log_open();
1050         log_parse_environment();
1051         udev_set_log_fn(udev, udev_main_log);
1052         log_debug("version %s\n", VERSION);
1053         label_init("/dev");
1054
1055         for (;;) {
1056                 int option;
1057
1058                 option = getopt_long(argc, argv, "c:deDtN:hV", options, NULL);
1059                 if (option == -1)
1060                         break;
1061
1062                 switch (option) {
1063                 case 'd':
1064                         daemonize = true;
1065                         break;
1066                 case 'c':
1067                         children_max = strtoul(optarg, NULL, 0);
1068                         break;
1069                 case 'e':
1070                         exec_delay = strtoul(optarg, NULL, 0);
1071                         break;
1072                 case 'D':
1073                         debug = true;
1074                         log_set_max_level(LOG_DEBUG);
1075                         udev_set_log_priority(udev, LOG_INFO);
1076                         break;
1077                 case 'N':
1078                         if (strcmp (optarg, "early") == 0) {
1079                                 resolve_names = 1;
1080                         } else if (strcmp (optarg, "late") == 0) {
1081                                 resolve_names = 0;
1082                         } else if (strcmp (optarg, "never") == 0) {
1083                                 resolve_names = -1;
1084                         } else {
1085                                 fprintf(stderr, "resolve-names must be early, late or never\n");
1086                                 log_error("resolve-names must be early, late or never\n");
1087                                 goto exit;
1088                         }
1089                         break;
1090                 case 'h':
1091                         printf("Usage: udevd OPTIONS\n"
1092                                "  --daemon\n"
1093                                "  --debug\n"
1094                                "  --children-max=<maximum number of workers>\n"
1095                                "  --exec-delay=<seconds to wait before executing RUN=>\n"
1096                                "  --resolve-names=early|late|never\n"
1097                                "  --version\n"
1098                                "  --help\n"
1099                                "\n");
1100                         goto exit;
1101                 case 'V':
1102                         printf("%s\n", VERSION);
1103                         goto exit;
1104                 default:
1105                         goto exit;
1106                 }
1107         }
1108
1109         /*
1110          * read the kernel commandline, in case we need to get into debug mode
1111          *   udev.log-priority=<level>              syslog priority
1112          *   udev.children-max=<number of workers>  events are fully serialized if set to 1
1113          *
1114          */
1115         f = fopen("/proc/cmdline", "r");
1116         if (f != NULL) {
1117                 char cmdline[4096];
1118
1119                 if (fgets(cmdline, sizeof(cmdline), f) != NULL) {
1120                         char *pos;
1121
1122                         pos = strstr(cmdline, "udev.log-priority=");
1123                         if (pos != NULL) {
1124                                 pos += strlen("udev.log-priority=");
1125                                 udev_set_log_priority(udev, util_log_priority(pos));
1126                         }
1127
1128                         pos = strstr(cmdline, "udev.children-max=");
1129                         if (pos != NULL) {
1130                                 pos += strlen("udev.children-max=");
1131                                 children_max = strtoul(pos, NULL, 0);
1132                         }
1133
1134                         pos = strstr(cmdline, "udev.exec-delay=");
1135                         if (pos != NULL) {
1136                                 pos += strlen("udev.exec-delay=");
1137                                 exec_delay = strtoul(pos, NULL, 0);
1138                         }
1139                 }
1140                 fclose(f);
1141         }
1142
1143         if (getuid() != 0) {
1144                 fprintf(stderr, "root privileges required\n");
1145                 log_error("root privileges required\n");
1146                 goto exit;
1147         }
1148
1149         /* set umask before creating any file/directory */
1150         chdir("/");
1151         umask(022);
1152
1153         mkdir("/run/udev", 0755);
1154
1155         dev_setup();
1156         static_dev_create_from_modules(udev);
1157
1158         /* before opening new files, make sure std{in,out,err} fds are in a sane state */
1159         if (daemonize) {
1160                 int fd;
1161
1162                 fd = open("/dev/null", O_RDWR);
1163                 if (fd >= 0) {
1164                         if (write(STDOUT_FILENO, 0, 0) < 0)
1165                                 dup2(fd, STDOUT_FILENO);
1166                         if (write(STDERR_FILENO, 0, 0) < 0)
1167                                 dup2(fd, STDERR_FILENO);
1168                         if (fd > STDERR_FILENO)
1169                                 close(fd);
1170                 } else {
1171                         fprintf(stderr, "cannot open /dev/null\n");
1172                         log_error("cannot open /dev/null\n");
1173                 }
1174         }
1175
1176         if (systemd_fds(udev, &fd_ctrl, &fd_netlink) >= 0) {
1177                 /* get control and netlink socket from from systemd */
1178                 udev_ctrl = udev_ctrl_new_from_fd(udev, fd_ctrl);
1179                 if (udev_ctrl == NULL) {
1180                         log_error("error taking over udev control socket");
1181                         rc = 1;
1182                         goto exit;
1183                 }
1184
1185                 monitor = udev_monitor_new_from_netlink_fd(udev, "kernel", fd_netlink);
1186                 if (monitor == NULL) {
1187                         log_error("error taking over netlink socket\n");
1188                         rc = 3;
1189                         goto exit;
1190                 }
1191
1192                 /* get our own cgroup, we regularly kill everything udev has left behind */
1193                 if (cg_get_by_pid(SYSTEMD_CGROUP_CONTROLLER, 0, &udev_cgroup) < 0)
1194                         udev_cgroup = NULL;
1195         } else {
1196                 /* open control and netlink socket */
1197                 udev_ctrl = udev_ctrl_new(udev);
1198                 if (udev_ctrl == NULL) {
1199                         fprintf(stderr, "error initializing udev control socket");
1200                         log_error("error initializing udev control socket");
1201                         rc = 1;
1202                         goto exit;
1203                 }
1204                 fd_ctrl = udev_ctrl_get_fd(udev_ctrl);
1205
1206                 monitor = udev_monitor_new_from_netlink(udev, "kernel");
1207                 if (monitor == NULL) {
1208                         fprintf(stderr, "error initializing netlink socket\n");
1209                         log_error("error initializing netlink socket\n");
1210                         rc = 3;
1211                         goto exit;
1212                 }
1213                 fd_netlink = udev_monitor_get_fd(monitor);
1214         }
1215
1216         if (udev_monitor_enable_receiving(monitor) < 0) {
1217                 fprintf(stderr, "error binding netlink socket\n");
1218                 log_error("error binding netlink socket\n");
1219                 rc = 3;
1220                 goto exit;
1221         }
1222
1223         if (udev_ctrl_enable_receiving(udev_ctrl) < 0) {
1224                 fprintf(stderr, "error binding udev control socket\n");
1225                 log_error("error binding udev control socket\n");
1226                 rc = 1;
1227                 goto exit;
1228         }
1229
1230         udev_monitor_set_receive_buffer_size(monitor, 128*1024*1024);
1231
1232         /* create queue file before signalling 'ready', to make sure we block 'settle' */
1233         udev_queue_export = udev_queue_export_new(udev);
1234         if (udev_queue_export == NULL) {
1235                 log_error("error creating queue file\n");
1236                 goto exit;
1237         }
1238
1239         if (daemonize) {
1240                 pid_t pid;
1241                 int fd;
1242
1243                 pid = fork();
1244                 switch (pid) {
1245                 case 0:
1246                         break;
1247                 case -1:
1248                         log_error("fork of daemon failed: %m\n");
1249                         rc = 4;
1250                         goto exit;
1251                 default:
1252                         rc = EXIT_SUCCESS;
1253                         goto exit_daemonize;
1254                 }
1255
1256                 setsid();
1257
1258                 fd = open("/proc/self/oom_score_adj", O_RDWR|O_CLOEXEC);
1259                 if (fd >= 0) {
1260                         write(fd, "-1000", 5);
1261                         close(fd);
1262                 }
1263         } else {
1264                 sd_notify(1, "READY=1");
1265         }
1266
1267         f = fopen("/dev/kmsg", "w");
1268         if (f != NULL) {
1269                 fprintf(f, "<30>udevd[%u]: starting version " VERSION "\n", getpid());
1270                 fclose(f);
1271         }
1272
1273         if (!debug) {
1274                 int fd;
1275
1276                 fd = open("/dev/null", O_RDWR);
1277                 if (fd >= 0) {
1278                         dup2(fd, STDIN_FILENO);
1279                         dup2(fd, STDOUT_FILENO);
1280                         dup2(fd, STDERR_FILENO);
1281                         close(fd);
1282                 }
1283         }
1284
1285         fd_inotify = udev_watch_init(udev);
1286         if (fd_inotify < 0) {
1287                 fprintf(stderr, "error initializing inotify\n");
1288                 log_error("error initializing inotify\n");
1289                 rc = 4;
1290                 goto exit;
1291         }
1292         udev_watch_restore(udev);
1293
1294         /* block and listen to all signals on signalfd */
1295         sigfillset(&mask);
1296         sigprocmask(SIG_SETMASK, &mask, &sigmask_orig);
1297         fd_signal = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC);
1298         if (fd_signal < 0) {
1299                 fprintf(stderr, "error creating signalfd\n");
1300                 log_error("error creating signalfd\n");
1301                 rc = 5;
1302                 goto exit;
1303         }
1304
1305         /* unnamed socket from workers to the main daemon */
1306         if (socketpair(AF_LOCAL, SOCK_DGRAM|SOCK_CLOEXEC, 0, worker_watch) < 0) {
1307                 fprintf(stderr, "error creating socketpair\n");
1308                 log_error("error creating socketpair\n");
1309                 rc = 6;
1310                 goto exit;
1311         }
1312         fd_worker = worker_watch[READ_END];
1313
1314         udev_builtin_init(udev);
1315
1316         rules = udev_rules_new(udev, resolve_names);
1317         if (rules == NULL) {
1318                 log_error("error reading rules\n");
1319                 goto exit;
1320         }
1321
1322         memset(&ep_ctrl, 0, sizeof(struct epoll_event));
1323         ep_ctrl.events = EPOLLIN;
1324         ep_ctrl.data.fd = fd_ctrl;
1325
1326         memset(&ep_inotify, 0, sizeof(struct epoll_event));
1327         ep_inotify.events = EPOLLIN;
1328         ep_inotify.data.fd = fd_inotify;
1329
1330         memset(&ep_signal, 0, sizeof(struct epoll_event));
1331         ep_signal.events = EPOLLIN;
1332         ep_signal.data.fd = fd_signal;
1333
1334         memset(&ep_netlink, 0, sizeof(struct epoll_event));
1335         ep_netlink.events = EPOLLIN;
1336         ep_netlink.data.fd = fd_netlink;
1337
1338         memset(&ep_worker, 0, sizeof(struct epoll_event));
1339         ep_worker.events = EPOLLIN;
1340         ep_worker.data.fd = fd_worker;
1341
1342         fd_ep = epoll_create1(EPOLL_CLOEXEC);
1343         if (fd_ep < 0) {
1344                 log_error("error creating epoll fd: %m\n");
1345                 goto exit;
1346         }
1347         if (epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_ctrl, &ep_ctrl) < 0 ||
1348             epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_inotify, &ep_inotify) < 0 ||
1349             epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_signal, &ep_signal) < 0 ||
1350             epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_netlink, &ep_netlink) < 0 ||
1351             epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_worker, &ep_worker) < 0) {
1352                 log_error("fail to add fds to epoll: %m\n");
1353                 goto exit;
1354         }
1355
1356         /* if needed, convert old database from earlier udev version */
1357         convert_db(udev);
1358
1359         if (children_max <= 0) {
1360                 int memsize = mem_size_mb();
1361
1362                 /* set value depending on the amount of RAM */
1363                 if (memsize > 0)
1364                         children_max = 128 + (memsize / 8);
1365                 else
1366                         children_max = 128;
1367         }
1368         log_debug("set children_max to %u\n", children_max);
1369
1370         udev_rules_apply_static_dev_perms(rules);
1371
1372         udev_list_node_init(&event_list);
1373         udev_list_node_init(&worker_list);
1374
1375         for (;;) {
1376                 static unsigned long long last_usec;
1377                 struct epoll_event ev[8];
1378                 int fdcount;
1379                 int timeout;
1380                 bool is_worker, is_signal, is_inotify, is_netlink, is_ctrl;
1381                 int i;
1382
1383                 if (udev_exit) {
1384                         /* close sources of new events and discard buffered events */
1385                         if (fd_ctrl >= 0) {
1386                                 epoll_ctl(fd_ep, EPOLL_CTL_DEL, fd_ctrl, NULL);
1387                                 fd_ctrl = -1;
1388                         }
1389                         if (monitor != NULL) {
1390                                 epoll_ctl(fd_ep, EPOLL_CTL_DEL, fd_netlink, NULL);
1391                                 udev_monitor_unref(monitor);
1392                                 monitor = NULL;
1393                         }
1394                         if (fd_inotify >= 0) {
1395                                 epoll_ctl(fd_ep, EPOLL_CTL_DEL, fd_inotify, NULL);
1396                                 close(fd_inotify);
1397                                 fd_inotify = -1;
1398                         }
1399
1400                         /* discard queued events and kill workers */
1401                         event_queue_cleanup(udev, EVENT_QUEUED);
1402                         worker_kill(udev);
1403
1404                         /* exit after all has cleaned up */
1405                         if (udev_list_node_is_empty(&event_list) && udev_list_node_is_empty(&worker_list))
1406                                 break;
1407
1408                         /* timeout at exit for workers to finish */
1409                         timeout = 30 * 1000;
1410                 } else if (udev_list_node_is_empty(&event_list) && !children) {
1411                         /* we are idle */
1412                         timeout = -1;
1413
1414                         /* cleanup possible left-over processes in our cgroup */
1415                         if (udev_cgroup)
1416                                 cg_kill(SYSTEMD_CGROUP_CONTROLLER, udev_cgroup, SIGKILL, false, true, NULL);
1417                 } else {
1418                         /* kill idle or hanging workers */
1419                         timeout = 3 * 1000;
1420                 }
1421                 fdcount = epoll_wait(fd_ep, ev, ELEMENTSOF(ev), timeout);
1422                 if (fdcount < 0)
1423                         continue;
1424
1425                 if (fdcount == 0) {
1426                         struct udev_list_node *loop;
1427
1428                         /* timeout */
1429                         if (udev_exit) {
1430                                 log_error("timeout, giving up waiting for workers to finish\n");
1431                                 break;
1432                         }
1433
1434                         /* kill idle workers */
1435                         if (udev_list_node_is_empty(&event_list)) {
1436                                 log_debug("cleanup idle workers\n");
1437                                 worker_kill(udev);
1438                         }
1439
1440                         /* check for hanging events */
1441                         udev_list_node_foreach(loop, &worker_list) {
1442                                 struct worker *worker = node_to_worker(loop);
1443
1444                                 if (worker->state != WORKER_RUNNING)
1445                                         continue;
1446
1447                                 if ((now_usec() - worker->event_start_usec) > 30 * 1000 * 1000) {
1448                                         log_error("worker [%u] %s timeout; kill it\n", worker->pid,
1449                                             worker->event ? worker->event->devpath : "<idle>");
1450                                         kill(worker->pid, SIGKILL);
1451                                         worker->state = WORKER_KILLED;
1452                                         /* drop reference taken for state 'running' */
1453                                         worker_unref(worker);
1454                                         if (worker->event) {
1455                                                 log_error("seq %llu '%s' killed\n",
1456                                                           udev_device_get_seqnum(worker->event->dev), worker->event->devpath);
1457                                                 worker->event->exitcode = -64;
1458                                                 event_queue_delete(worker->event, true);
1459                                                 worker->event = NULL;
1460                                         }
1461                                 }
1462                         }
1463
1464                 }
1465
1466                 is_worker = is_signal = is_inotify = is_netlink = is_ctrl = false;
1467                 for (i = 0; i < fdcount; i++) {
1468                         if (ev[i].data.fd == fd_worker && ev[i].events & EPOLLIN)
1469                                 is_worker = true;
1470                         else if (ev[i].data.fd == fd_netlink && ev[i].events & EPOLLIN)
1471                                 is_netlink = true;
1472                         else if (ev[i].data.fd == fd_signal && ev[i].events & EPOLLIN)
1473                                 is_signal = true;
1474                         else if (ev[i].data.fd == fd_inotify && ev[i].events & EPOLLIN)
1475                                 is_inotify = true;
1476                         else if (ev[i].data.fd == fd_ctrl && ev[i].events & EPOLLIN)
1477                                 is_ctrl = true;
1478                 }
1479
1480                 /* check for changed config, every 3 seconds at most */
1481                 if ((now_usec() - last_usec) > 3 * 1000 * 1000) {
1482                         if (udev_rules_check_timestamp(rules))
1483                                 reload = true;
1484                         if (udev_builtin_validate(udev))
1485                                 reload = true;
1486
1487                         last_usec = now_usec();
1488                 }
1489
1490                 /* reload requested, HUP signal received, rules changed, builtin changed */
1491                 if (reload) {
1492                         worker_kill(udev);
1493                         rules = udev_rules_unref(rules);
1494                         udev_builtin_exit(udev);
1495                         reload = 0;
1496                 }
1497
1498                 /* event has finished */
1499                 if (is_worker)
1500                         worker_returned(fd_worker);
1501
1502                 if (is_netlink) {
1503                         struct udev_device *dev;
1504
1505                         dev = udev_monitor_receive_device(monitor);
1506                         if (dev != NULL) {
1507                                 udev_device_set_usec_initialized(dev, now_usec());
1508                                 if (event_queue_insert(dev) < 0)
1509                                         udev_device_unref(dev);
1510                         }
1511                 }
1512
1513                 /* start new events */
1514                 if (!udev_list_node_is_empty(&event_list) && !udev_exit && !stop_exec_queue) {
1515                         if (rules == NULL)
1516                                 rules = udev_rules_new(udev, resolve_names);
1517                         if (rules != NULL)
1518                                 event_queue_start(udev);
1519                 }
1520
1521                 if (is_signal) {
1522                         struct signalfd_siginfo fdsi;
1523                         ssize_t size;
1524
1525                         size = read(fd_signal, &fdsi, sizeof(struct signalfd_siginfo));
1526                         if (size == sizeof(struct signalfd_siginfo))
1527                                 handle_signal(udev, fdsi.ssi_signo);
1528                 }
1529
1530                 /* we are shutting down, the events below are not handled anymore */
1531                 if (udev_exit)
1532                         continue;
1533
1534                 /* device node watch */
1535                 if (is_inotify)
1536                         handle_inotify(udev);
1537
1538                 /*
1539                  * This needs to be after the inotify handling, to make sure,
1540                  * that the ping is send back after the possibly generated
1541                  * "change" events by the inotify device node watch.
1542                  *
1543                  * A single time we may receive a client connection which we need to
1544                  * keep open to block the client. It will be closed right before we
1545                  * exit.
1546                  */
1547                 if (is_ctrl)
1548                         ctrl_conn = handle_ctrl_msg(udev_ctrl);
1549         }
1550
1551         rc = EXIT_SUCCESS;
1552 exit:
1553         udev_queue_export_cleanup(udev_queue_export);
1554         udev_ctrl_cleanup(udev_ctrl);
1555 exit_daemonize:
1556         if (fd_ep >= 0)
1557                 close(fd_ep);
1558         worker_list_cleanup(udev);
1559         event_queue_cleanup(udev, EVENT_UNDEF);
1560         udev_rules_unref(rules);
1561         udev_builtin_exit(udev);
1562         if (fd_signal >= 0)
1563                 close(fd_signal);
1564         if (worker_watch[READ_END] >= 0)
1565                 close(worker_watch[READ_END]);
1566         if (worker_watch[WRITE_END] >= 0)
1567                 close(worker_watch[WRITE_END]);
1568         udev_monitor_unref(monitor);
1569         udev_queue_export_unref(udev_queue_export);
1570         udev_ctrl_connection_unref(ctrl_conn);
1571         udev_ctrl_unref(udev_ctrl);
1572         label_finish();
1573         udev_unref(udev);
1574         log_close();
1575         return rc;
1576 }