udev/udevd.c

   1 /*
   2  * Copyright (C) 2004-2011 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
  50 static bool debug;
  51
  52 static void log_fn(struct udev *udev, int priority,
  53                    const char *file, int line, const char *fn,
  54                    const char *format, va_list args)
  55 {
  56         if (debug) {
  57                 char buf[1024];
  58                 struct timeval tv;
  59                 struct timezone tz;
  60
  61                 vsnprintf(buf, sizeof(buf), format, args);
  62                 gettimeofday(&tv, &tz);
  63                 fprintf(stderr, "%llu.%06u [%u] %s: %s",
  64                         (unsigned long long) tv.tv_sec, (unsigned int) tv.tv_usec,
  65                         (int) getpid(), fn, buf);
  66         } else {
  67                 vsyslog(priority, format, args);
  68         }
  69 }
  70
  71 static struct udev_rules *rules;
  72 static struct udev_queue_export *udev_queue_export;
  73 static struct udev_ctrl *udev_ctrl;
  74 static struct udev_monitor *monitor;
  75 static int worker_watch[2] = { -1, -1 };
  76 static int fd_signal = -1;
  77 static int fd_ep = -1;
  78 static int fd_inotify = -1;
  79 static bool stop_exec_queue;
  80 static bool reload_config;
  81 static int children;
  82 static int children_max;
  83 static int exec_delay;
  84 static sigset_t orig_sigmask;
  85 static UDEV_LIST(event_list);
  86 static UDEV_LIST(worker_list);
  87 static bool udev_exit;
  88 static volatile sig_atomic_t worker_exit;
  89
  90 enum event_state {
  91         EVENT_UNDEF,
  92         EVENT_QUEUED,
  93         EVENT_RUNNING,
  94 };
  95
  96 struct event {
  97         struct udev_list_node node;
  98         struct udev *udev;
  99         struct udev_device *dev;
 100         enum event_state state;
 101         int exitcode;
 102         unsigned long long int delaying_seqnum;
 103         unsigned long long int seqnum;
 104         const char *devpath;
 105         size_t devpath_len;
 106         const char *devpath_old;
 107         dev_t devnum;
 108         bool is_block;
 109         int ifindex;
 110 };
 111
 112 static struct event *node_to_event(struct udev_list_node *node)
 113 {
 114         char *event;
 115
 116         event = (char *)node;
 117         event -= offsetof(struct event, node);
 118         return (struct event *)event;
 119 }
 120
 121 static void event_queue_cleanup(struct udev *udev, enum event_state type);
 122
 123 enum worker_state {
 124         WORKER_UNDEF,
 125         WORKER_RUNNING,
 126         WORKER_IDLE,
 127         WORKER_KILLED,
 128 };
 129
 130 struct worker {
 131         struct udev_list_node node;
 132         struct udev *udev;
 133         int refcount;
 134         pid_t pid;
 135         struct udev_monitor *monitor;
 136         enum worker_state state;
 137         struct event *event;
 138 };
 139
 140 /* passed from worker to main process */
 141 struct worker_message {
 142         pid_t pid;
 143         int exitcode;
 144 };
 145
 146 static struct worker *node_to_worker(struct udev_list_node *node)
 147 {
 148         char *worker;
 149
 150         worker = (char *)node;
 151         worker -= offsetof(struct worker, node);
 152         return (struct worker *)worker;
 153 }
 154
 155 static void event_queue_delete(struct event *event, bool export)
 156 {
 157         udev_list_node_remove(&event->node);
 158
 159         if (export) {
 160                 /* mark as failed, if "add" event returns non-zero */
 161                 if (event->exitcode != 0 && strcmp(udev_device_get_action(event->dev), "remove") != 0)
 162                         udev_queue_export_device_failed(udev_queue_export, event->dev);
 163                 else
 164                         udev_queue_export_device_finished(udev_queue_export, event->dev);
 165                 info(event->udev, "seq %llu done with %i\n", udev_device_get_seqnum(event->dev), event->exitcode);
 166         }
 167         udev_device_unref(event->dev);
 168         free(event);
 169 }
 170
 171 static void event_sig_handler(int signum)
 172 {
 173         switch (signum) {
 174         case SIGALRM:
 175                 _exit(1);
 176                 break;
 177         case SIGTERM:
 178                 worker_exit = true;
 179                 break;
 180         }
 181 }
 182
 183 static struct worker *worker_ref(struct worker *worker)
 184 {
 185         worker->refcount++;
 186         return worker;
 187 }
 188
 189 static void worker_cleanup(struct worker *worker)
 190 {
 191         udev_list_node_remove(&worker->node);
 192         udev_monitor_unref(worker->monitor);
 193         children--;
 194         free(worker);
 195 }
 196
 197 static void worker_unref(struct worker *worker)
 198 {
 199         worker->refcount--;
 200         if (worker->refcount > 0)
 201                 return;
 202         info(worker->udev, "worker [%u] cleaned up\n", worker->pid);
 203         worker_cleanup(worker);
 204 }
 205
 206 static void worker_list_cleanup(struct udev *udev)
 207 {
 208         struct udev_list_node *loop, *tmp;
 209
 210         udev_list_node_foreach_safe(loop, tmp, &worker_list) {
 211                 struct worker *worker = node_to_worker(loop);
 212
 213                 worker_cleanup(worker);
 214         }
 215 }
 216
 217 static void worker_new(struct event *event)
 218 {
 219         struct udev *udev = event->udev;
 220         struct worker *worker;
 221         struct udev_monitor *worker_monitor;
 222         pid_t pid;
 223         struct sigaction act;
 224
 225         /* listen for new events */
 226         worker_monitor = udev_monitor_new_from_netlink(udev, NULL);
 227         if (worker_monitor == NULL)
 228                 return;
 229         /* allow the main daemon netlink address to send devices to the worker */
 230         udev_monitor_allow_unicast_sender(worker_monitor, monitor);
 231         udev_monitor_enable_receiving(worker_monitor);
 232
 233         worker = calloc(1, sizeof(struct worker));
 234         if (worker == NULL) {
 235                 udev_monitor_unref(worker_monitor);
 236                 return;
 237         }
 238         /* worker + event reference */
 239         worker->refcount = 2;
 240         worker->udev = udev;
 241
 242         pid = fork();
 243         switch (pid) {
 244         case 0: {
 245                 sigset_t sigmask;
 246                 struct udev_device *dev;
 247                 struct pollfd pmon = {
 248                         .fd = udev_monitor_get_fd(worker_monitor),
 249                         .events = POLLIN,
 250                 };
 251
 252                 /* move initial device from queue */
 253                 dev = event->dev;
 254                 event->dev = NULL;
 255
 256                 free(worker);
 257                 worker_list_cleanup(udev);
 258                 event_queue_cleanup(udev, EVENT_UNDEF);
 259                 udev_queue_export_unref(udev_queue_export);
 260                 udev_monitor_unref(monitor);
 261                 udev_ctrl_unref(udev_ctrl);
 262                 close(fd_signal);
 263                 close(fd_ep);
 264                 close(worker_watch[READ_END]);
 265                 udev_log_close();
 266                 udev_log_init("udevd-work");
 267
 268                 /* set signal handlers */
 269                 memset(&act, 0x00, sizeof(act));
 270                 act.sa_handler = event_sig_handler;
 271                 sigemptyset (&act.sa_mask);
 272                 act.sa_flags = 0;
 273                 sigaction(SIGTERM, &act, NULL);
 274                 sigaction(SIGALRM, &act, NULL);
 275
 276                 /* unblock SIGALRM */
 277                 sigfillset(&sigmask);
 278                 sigdelset(&sigmask, SIGALRM);
 279                 sigprocmask(SIG_SETMASK, &sigmask, NULL);
 280                 /* SIGTERM is unblocked in ppoll() */
 281                 sigdelset(&sigmask, SIGTERM);
 282
 283                 /* request TERM signal if parent exits */
 284                 prctl(PR_SET_PDEATHSIG, SIGTERM);
 285
 286                 do {
 287                         struct udev_event *udev_event;
 288                         struct worker_message msg = {};
 289                         int err;
 290                         int failed = 0;
 291
 292                         info(udev, "seq %llu running\n", udev_device_get_seqnum(dev));
 293                         udev_event = udev_event_new(dev);
 294                         if (udev_event == NULL)
 295                                 _exit(3);
 296
 297                         /* set timeout to prevent hanging processes */
 298                         alarm(UDEV_EVENT_TIMEOUT);
 299
 300                         if (exec_delay > 0)
 301                                 udev_event->exec_delay = exec_delay;
 302
 303                         /* apply rules, create node, symlinks */
 304                         err = udev_event_execute_rules(udev_event, rules);
 305
 306                         /* rules may change/disable the timeout */
 307                         if (udev_device_get_event_timeout(dev) >= 0)
 308                                 alarm(udev_device_get_event_timeout(dev));
 309
 310                         if (err == 0)
 311                                 failed = udev_event_execute_run(udev_event, &orig_sigmask);
 312
 313                         alarm(0);
 314
 315                         /* apply/restore inotify watch */
 316                         if (err == 0 && udev_event->inotify_watch) {
 317                                 udev_watch_begin(udev, dev);
 318                                 udev_device_update_db(dev);
 319                         }
 320
 321                         /* send processed event back to libudev listeners */
 322                         udev_monitor_send_device(worker_monitor, NULL, dev);
 323
 324                         /* send udevd the result of the event execution */
 325                         if (err != 0)
 326                                 msg.exitcode = err;
 327                         else if (failed != 0)
 328                                 msg.exitcode = failed;
 329                         msg.pid = getpid();
 330                         send(worker_watch[WRITE_END], &msg, sizeof(struct worker_message), 0);
 331
 332                         info(udev, "seq %llu processed with %i\n", udev_device_get_seqnum(dev), err);
 333                         udev_event_unref(udev_event);
 334                         udev_device_unref(dev);
 335                         dev = NULL;
 336
 337                         /* wait for more device messages or signal from udevd */
 338                         while (!worker_exit) {
 339                                 int fdcount;
 340
 341                                 fdcount = ppoll(&pmon, 1, NULL, &sigmask);
 342                                 if (fdcount < 0)
 343                                         continue;
 344
 345                                 if (pmon.revents & POLLIN) {
 346                                         dev = udev_monitor_receive_device(worker_monitor);
 347                                         if (dev != NULL)
 348                                                 break;
 349                                 }
 350                         }
 351                 } while (dev != NULL);
 352
 353                 close(fd_inotify);
 354                 close(worker_watch[WRITE_END]);
 355                 udev_rules_unref(rules);
 356                 udev_monitor_unref(worker_monitor);
 357                 udev_unref(udev);
 358                 udev_log_close();
 359                 exit(EXIT_SUCCESS);
 360         }
 361         case -1:
 362                 udev_monitor_unref(worker_monitor);
 363                 event->state = EVENT_QUEUED;
 364                 free(worker);
 365                 err(udev, "fork of child failed: %m\n");
 366                 break;
 367         default:
 368                 /* close monitor, but keep address around */
 369                 udev_monitor_disconnect(worker_monitor);
 370                 worker->monitor = worker_monitor;
 371                 worker->pid = pid;
 372                 worker->state = WORKER_RUNNING;
 373                 worker->event = event;
 374                 event->state = EVENT_RUNNING;
 375                 udev_list_node_append(&worker->node, &worker_list);
 376                 children++;
 377                 info(udev, "seq %llu forked new worker [%u]\n", udev_device_get_seqnum(event->dev), pid);
 378                 break;
 379         }
 380 }
 381
 382 static void event_run(struct event *event, bool force)
 383 {
 384         struct udev_list_node *loop;
 385
 386         udev_list_node_foreach(loop, &worker_list) {
 387                 struct worker *worker = node_to_worker(loop);
 388                 ssize_t count;
 389
 390                 if (worker->state != WORKER_IDLE)
 391                         continue;
 392
 393                 count = udev_monitor_send_device(monitor, worker->monitor, event->dev);
 394                 if (count < 0) {
 395                         err(event->udev, "worker [%u] did not accept message %zi (%m), kill it\n", worker->pid, count);
 396                         kill(worker->pid, SIGKILL);
 397                         worker->state = WORKER_KILLED;
 398                         continue;
 399                 }
 400                 worker_ref(worker);
 401                 worker->event = event;
 402                 worker->state = WORKER_RUNNING;
 403                 event->state = EVENT_RUNNING;
 404                 return;
 405         }
 406
 407         if (!force && children >= children_max) {
 408                 if (children_max > 1)
 409                         info(event->udev, "maximum number (%i) of children reached\n", children);
 410                 return;
 411         }
 412
 413         /* start new worker and pass initial device */
 414         worker_new(event);
 415 }
 416
 417 static int event_queue_insert(struct udev_device *dev)
 418 {
 419         struct event *event;
 420
 421         event = calloc(1, sizeof(struct event));
 422         if (event == NULL)
 423                 return -1;
 424
 425         event->udev = udev_device_get_udev(dev);
 426         event->dev = dev;
 427         event->seqnum = udev_device_get_seqnum(dev);
 428         event->devpath = udev_device_get_devpath(dev);
 429         event->devpath_len = strlen(event->devpath);
 430         event->devpath_old = udev_device_get_devpath_old(dev);
 431         event->devnum = udev_device_get_devnum(dev);
 432         event->is_block = (strcmp("block", udev_device_get_subsystem(dev)) == 0);
 433         event->ifindex = udev_device_get_ifindex(dev);
 434
 435         udev_queue_export_device_queued(udev_queue_export, dev);
 436         info(event->udev, "seq %llu queued, '%s' '%s'\n", udev_device_get_seqnum(dev),
 437              udev_device_get_action(dev), udev_device_get_subsystem(dev));
 438
 439         event->state = EVENT_QUEUED;
 440         udev_list_node_append(&event->node, &event_list);
 441
 442         /* run all events with a timeout set immediately */
 443         if (udev_device_get_timeout(dev) > 0) {
 444                 event_run(event, true);
 445                 return 0;
 446         }
 447
 448         return 0;
 449 }
 450
 451 static void worker_kill(struct udev *udev, int retain)
 452 {
 453         struct udev_list_node *loop;
 454         int max;
 455
 456         if (children <= retain)
 457                 return;
 458
 459         max = children - retain;
 460
 461         udev_list_node_foreach(loop, &worker_list) {
 462                 struct worker *worker = node_to_worker(loop);
 463
 464                 if (max-- <= 0)
 465                         break;
 466
 467                 if (worker->state == WORKER_KILLED)
 468                         continue;
 469
 470                 worker->state = WORKER_KILLED;
 471                 kill(worker->pid, SIGTERM);
 472         }
 473 }
 474
 475 /* lookup event for identical, parent, child device */
 476 static bool is_devpath_busy(struct event *event)
 477 {
 478         struct udev_list_node *loop;
 479         size_t common;
 480
 481         /* check if queue contains events we depend on */
 482         udev_list_node_foreach(loop, &event_list) {
 483                 struct event *loop_event = node_to_event(loop);
 484
 485                 /* we already found a later event, earlier can not block us, no need to check again */
 486                 if (loop_event->seqnum < event->delaying_seqnum)
 487                         continue;
 488
 489                 /* event we checked earlier still exists, no need to check again */
 490                 if (loop_event->seqnum == event->delaying_seqnum)
 491                         return true;
 492
 493                 /* found ourself, no later event can block us */
 494                 if (loop_event->seqnum >= event->seqnum)
 495                         break;
 496
 497                 /* check major/minor */
 498                 if (major(event->devnum) != 0 && event->devnum == loop_event->devnum && event->is_block == loop_event->is_block)
 499                         return true;
 500
 501                 /* check network device ifindex */
 502                 if (event->ifindex != 0 && event->ifindex == loop_event->ifindex)
 503                         return true;
 504
 505                 /* check our old name */
 506                 if (event->devpath_old != NULL && strcmp(loop_event->devpath, event->devpath_old) == 0) {
 507                         event->delaying_seqnum = loop_event->seqnum;
 508                         return true;
 509                 }
 510
 511                 /* compare devpath */
 512                 common = MIN(loop_event->devpath_len, event->devpath_len);
 513
 514                 /* one devpath is contained in the other? */
 515                 if (memcmp(loop_event->devpath, event->devpath, common) != 0)
 516                         continue;
 517
 518                 /* identical device event found */
 519                 if (loop_event->devpath_len == event->devpath_len) {
 520                         /* devices names might have changed/swapped in the meantime */
 521                         if (major(event->devnum) != 0 && (event->devnum != loop_event->devnum || event->is_block != loop_event->is_block))
 522                                 continue;
 523                         if (event->ifindex != 0 && event->ifindex != loop_event->ifindex)
 524                                 continue;
 525                         event->delaying_seqnum = loop_event->seqnum;
 526                         return true;
 527                 }
 528
 529                 /* parent device event found */
 530                 if (event->devpath[common] == '/') {
 531                         event->delaying_seqnum = loop_event->seqnum;
 532                         return true;
 533                 }
 534
 535                 /* child device event found */
 536                 if (loop_event->devpath[common] == '/') {
 537                         event->delaying_seqnum = loop_event->seqnum;
 538                         return true;
 539                 }
 540
 541                 /* no matching device */
 542                 continue;
 543         }
 544
 545         return false;
 546 }
 547
 548 static void event_queue_start(struct udev *udev)
 549 {
 550         struct udev_list_node *loop;
 551
 552         udev_list_node_foreach(loop, &event_list) {
 553                 struct event *event = node_to_event(loop);
 554
 555                 if (event->state != EVENT_QUEUED)
 556                         continue;
 557
 558                 /* do not start event if parent or child event is still running */
 559                 if (is_devpath_busy(event)) {
 560                         dbg(udev, "delay seq %llu (%s)\n", event->seqnum, event->devpath);
 561                         continue;
 562                 }
 563
 564                 event_run(event, false);
 565         }
 566 }
 567
 568 static void event_queue_cleanup(struct udev *udev, enum event_state match_type)
 569 {
 570         struct udev_list_node *loop, *tmp;
 571
 572         udev_list_node_foreach_safe(loop, tmp, &event_list) {
 573                 struct event *event = node_to_event(loop);
 574
 575                 if (match_type != EVENT_UNDEF && match_type != event->state)
 576                         continue;
 577
 578                 event_queue_delete(event, false);
 579         }
 580 }
 581
 582 static void worker_returned(int fd_worker)
 583 {
 584         for (;;) {
 585                 struct worker_message msg;
 586                 ssize_t size;
 587                 struct udev_list_node *loop;
 588
 589                 size = recv(fd_worker, &msg, sizeof(struct worker_message), MSG_DONTWAIT);
 590                 if (size != sizeof(struct worker_message))
 591                         break;
 592
 593                 /* lookup worker who sent the signal */
 594                 udev_list_node_foreach(loop, &worker_list) {
 595                         struct worker *worker = node_to_worker(loop);
 596
 597                         if (worker->pid != msg.pid)
 598                                 continue;
 599
 600                         /* worker returned */
 601                         worker->event->exitcode = msg.exitcode;
 602                         event_queue_delete(worker->event, true);
 603                         worker->event = NULL;
 604                         if (worker->state != WORKER_KILLED)
 605                                 worker->state = WORKER_IDLE;
 606                         worker_unref(worker);
 607                         break;
 608                 }
 609         }
 610 }
 611
 612 /* receive the udevd message from userspace */
 613 static struct udev_ctrl_connection *handle_ctrl_msg(struct udev_ctrl *uctrl)
 614 {
 615         struct udev *udev = udev_ctrl_get_udev(uctrl);
 616         struct udev_ctrl_connection *ctrl_conn;
 617         struct udev_ctrl_msg *ctrl_msg = NULL;
 618         const char *str;
 619         int i;
 620
 621         ctrl_conn = udev_ctrl_get_connection(uctrl);
 622         if (ctrl_conn == NULL)
 623                 goto out;
 624
 625         ctrl_msg = udev_ctrl_receive_msg(ctrl_conn);
 626         if (ctrl_msg == NULL)
 627                 goto out;
 628
 629         i = udev_ctrl_get_set_log_level(ctrl_msg);
 630         if (i >= 0) {
 631                 info(udev, "udevd message (SET_LOG_PRIORITY) received, log_priority=%i\n", i);
 632                 udev_set_log_priority(udev, i);
 633                 worker_kill(udev, 0);
 634         }
 635
 636         if (udev_ctrl_get_stop_exec_queue(ctrl_msg) > 0) {
 637                 info(udev, "udevd message (STOP_EXEC_QUEUE) received\n");
 638                 stop_exec_queue = true;
 639         }
 640
 641         if (udev_ctrl_get_start_exec_queue(ctrl_msg) > 0) {
 642                 info(udev, "udevd message (START_EXEC_QUEUE) received\n");
 643                 stop_exec_queue = false;
 644         }
 645
 646         if (udev_ctrl_get_reload_rules(ctrl_msg) > 0) {
 647                 info(udev, "udevd message (RELOAD_RULES) received\n");
 648                 reload_config = true;
 649         }
 650
 651         str = udev_ctrl_get_set_env(ctrl_msg);
 652         if (str != NULL) {
 653                 char *key;
 654
 655                 key = strdup(str);
 656                 if (key != NULL) {
 657                         char *val;
 658
 659                         val = strchr(key, '=');
 660                         if (val != NULL) {
 661                                 val[0] = '\0';
 662                                 val = &val[1];
 663                                 if (val[0] == '\0') {
 664                                         info(udev, "udevd message (ENV) received, unset '%s'\n", key);
 665                                         udev_add_property(udev, key, NULL);
 666                                 } else {
 667                                         info(udev, "udevd message (ENV) received, set '%s=%s'\n", key, val);
 668                                         udev_add_property(udev, key, val);
 669                                 }
 670                         } else {
 671                                 err(udev, "wrong key format '%s'\n", key);
 672                         }
 673                         free(key);
 674                 }
 675                 worker_kill(udev, 0);
 676         }
 677
 678         i = udev_ctrl_get_set_children_max(ctrl_msg);
 679         if (i >= 0) {
 680                 info(udev, "udevd message (SET_MAX_CHILDREN) received, children_max=%i\n", i);
 681                 children_max = i;
 682         }
 683
 684         if (udev_ctrl_get_ping(ctrl_msg) > 0)
 685                 info(udev, "udevd message (SYNC) received\n");
 686
 687         if (udev_ctrl_get_exit(ctrl_msg) > 0) {
 688                 info(udev, "udevd message (EXIT) received\n");
 689                 udev_exit = true;
 690                 /* keep reference to block the client until we exit */
 691                 udev_ctrl_connection_ref(ctrl_conn);
 692         }
 693 out:
 694         udev_ctrl_msg_unref(ctrl_msg);
 695         return udev_ctrl_connection_unref(ctrl_conn);
 696 }
 697
 698 /* read inotify messages */
 699 static int handle_inotify(struct udev *udev)
 700 {
 701         int nbytes, pos;
 702         char *buf;
 703         struct inotify_event *ev;
 704
 705         if ((ioctl(fd_inotify, FIONREAD, &nbytes) < 0) || (nbytes <= 0))
 706                 return 0;
 707
 708         buf = malloc(nbytes);
 709         if (buf == NULL) {
 710                 err(udev, "error getting buffer for inotify\n");
 711                 return -1;
 712         }
 713
 714         nbytes = read(fd_inotify, buf, nbytes);
 715
 716         for (pos = 0; pos < nbytes; pos += sizeof(struct inotify_event) + ev->len) {
 717                 struct udev_device *dev;
 718
 719                 ev = (struct inotify_event *)(buf + pos);
 720                 if (ev->len) {
 721                         const char *s;
 722
 723                         info(udev, "inotify event: %x for %s\n", ev->mask, ev->name);
 724                         s = strstr(ev->name, ".rules");
 725                         if (s == NULL)
 726                                 continue;
 727                         if (strlen(s) != strlen(".rules"))
 728                                 continue;
 729                         reload_config = true;
 730                         continue;
 731                 }
 732
 733                 dev = udev_watch_lookup(udev, ev->wd);
 734                 if (dev != NULL) {
 735                         info(udev, "inotify event: %x for %s\n", ev->mask, udev_device_get_devnode(dev));
 736                         if (ev->mask & IN_CLOSE_WRITE) {
 737                                 char filename[UTIL_PATH_SIZE];
 738                                 int fd;
 739
 740                                 info(udev, "device %s closed, synthesising 'change'\n", udev_device_get_devnode(dev));
 741                                 util_strscpyl(filename, sizeof(filename), udev_device_get_syspath(dev), "/uevent", NULL);
 742                                 fd = open(filename, O_WRONLY);
 743                                 if (fd >= 0) {
 744                                         if (write(fd, "change", 6) < 0)
 745                                                 info(udev, "error writing uevent: %m\n");
 746                                         close(fd);
 747                                 }
 748                         }
 749                         if (ev->mask & IN_IGNORED)
 750                                 udev_watch_end(udev, dev);
 751
 752                         udev_device_unref(dev);
 753                 }
 754
 755         }
 756
 757         free(buf);
 758         return 0;
 759 }
 760
 761 static void handle_signal(struct udev *udev, int signo)
 762 {
 763         switch (signo) {
 764         case SIGINT:
 765         case SIGTERM:
 766                 udev_exit = true;
 767                 break;
 768         case SIGCHLD:
 769                 for (;;) {
 770                         pid_t pid;
 771                         int status;
 772                         struct udev_list_node *loop, *tmp;
 773
 774                         pid = waitpid(-1, &status, WNOHANG);
 775                         if (pid <= 0)
 776                                 break;
 777
 778                         udev_list_node_foreach_safe(loop, tmp, &worker_list) {
 779                                 struct worker *worker = node_to_worker(loop);
 780
 781                                 if (worker->pid != pid)
 782                                         continue;
 783
 784                                 info(udev, "worker [%u] exit\n", pid);
 785                                 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
 786                                         err(udev, "worker [%u] unexpectedly returned with status 0x%04x\n", pid, status);
 787                                         if (worker->event != NULL) {
 788                                                 err(udev, "worker [%u] failed while handling '%s'\n", pid, worker->event->devpath);
 789                                                 worker->event->exitcode = -32;
 790                                                 event_queue_delete(worker->event, true);
 791                                                 /* drop reference from running event */
 792                                                 worker_unref(worker);
 793                                         }
 794                                 }
 795                                 worker_unref(worker);
 796                                 break;
 797                         }
 798                 }
 799                 break;
 800         case SIGHUP:
 801                 reload_config = 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 = 0600 | S_IFCHR;
 855                 else if (type == 'b')
 856                         mode = 0600 | S_IFBLK;
 857                 else
 858                         continue;
 859
 860                 util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev), "/", devname, NULL);
 861                 util_create_path_selinux(udev, filename);
 862                 udev_selinux_setfscreatecon(udev, filename, mode);
 863                 info(udev, "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                 udev_selinux_resetfscreatecon(udev);
 867         }
 868
 869         fclose(f);
 870 }
 871
 872 static int copy_dev_dir(struct udev *udev, DIR *dir_from, DIR *dir_to, int maxdepth)
 873 {
 874         struct dirent *dent;
 875
 876         for (dent = readdir(dir_from); dent != NULL; dent = readdir(dir_from)) {
 877                 struct stat stats;
 878
 879                 if (dent->d_name[0] == '.')
 880                         continue;
 881                 if (fstatat(dirfd(dir_from), dent->d_name, &stats, AT_SYMLINK_NOFOLLOW) != 0)
 882                         continue;
 883
 884                 if (S_ISBLK(stats.st_mode) || S_ISCHR(stats.st_mode)) {
 885                         udev_selinux_setfscreateconat(udev, dirfd(dir_to), dent->d_name, stats.st_mode & 0777);
 886                         if (mknodat(dirfd(dir_to), dent->d_name, stats.st_mode, stats.st_rdev) == 0) {
 887                                 fchmodat(dirfd(dir_to), dent->d_name, stats.st_mode & 0777, 0);
 888                                 fchownat(dirfd(dir_to), dent->d_name, stats.st_uid, stats.st_gid, 0);
 889                         } else {
 890                                 utimensat(dirfd(dir_to), dent->d_name, NULL, 0);
 891                         }
 892                         udev_selinux_resetfscreatecon(udev);
 893                 } else if (S_ISLNK(stats.st_mode)) {
 894                         char target[UTIL_PATH_SIZE];
 895                         ssize_t len;
 896
 897                         len = readlinkat(dirfd(dir_from), dent->d_name, target, sizeof(target));
 898                         if (len <= 0 || len == (ssize_t)sizeof(target))
 899                                 continue;
 900                         target[len] = '\0';
 901                         udev_selinux_setfscreateconat(udev, dirfd(dir_to), dent->d_name, S_IFLNK);
 902                         if (symlinkat(target, dirfd(dir_to), dent->d_name) < 0 && errno == EEXIST)
 903                                 utimensat(dirfd(dir_to), dent->d_name, NULL, AT_SYMLINK_NOFOLLOW);
 904                         udev_selinux_resetfscreatecon(udev);
 905                 } else if (S_ISDIR(stats.st_mode)) {
 906                         DIR *dir2_from, *dir2_to;
 907
 908                         if (maxdepth == 0)
 909                                 continue;
 910
 911                         udev_selinux_setfscreateconat(udev, dirfd(dir_to), dent->d_name, S_IFDIR|0755);
 912                         mkdirat(dirfd(dir_to), dent->d_name, 0755);
 913                         udev_selinux_resetfscreatecon(udev);
 914
 915                         dir2_to = fdopendir(openat(dirfd(dir_to), dent->d_name, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC));
 916                         if (dir2_to == NULL)
 917                                 continue;
 918
 919                         dir2_from = fdopendir(openat(dirfd(dir_from), dent->d_name, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC));
 920                         if (dir2_from == NULL) {
 921                                 closedir(dir2_to);
 922                                 continue;
 923                         }
 924
 925                         copy_dev_dir(udev, dir2_from, dir2_to, maxdepth-1);
 926
 927                         closedir(dir2_to);
 928                         closedir(dir2_from);
 929                 }
 930         }
 931
 932         return 0;
 933 }
 934
 935 static void static_dev_create_links(struct udev *udev, DIR *dir)
 936 {
 937         struct stdlinks {
 938                 const char *link;
 939                 const char *target;
 940         };
 941         static const struct stdlinks stdlinks[] = {
 942                 { "core", "/proc/kcore" },
 943                 { "fd", "/proc/self/fd" },
 944                 { "stdin", "/proc/self/fd/0" },
 945                 { "stdout", "/proc/self/fd/1" },
 946                 { "stderr", "/proc/self/fd/2" },
 947         };
 948         unsigned int i;
 949
 950         for (i = 0; i < ARRAY_SIZE(stdlinks); i++) {
 951                 struct stat sb;
 952
 953                 if (stat(stdlinks[i].target, &sb) == 0) {
 954                         udev_selinux_setfscreateconat(udev, dirfd(dir), stdlinks[i].link, S_IFLNK);
 955                         if (symlinkat(stdlinks[i].target, dirfd(dir), stdlinks[i].link) < 0 && errno == EEXIST)
 956                                 utimensat(dirfd(dir), stdlinks[i].link, NULL, AT_SYMLINK_NOFOLLOW);
 957                         udev_selinux_resetfscreatecon(udev);
 958                 }
 959         }
 960 }
 961
 962 static void static_dev_create_from_devices(struct udev *udev, DIR *dir)
 963 {
 964         DIR *dir_from;
 965
 966         dir_from = opendir(LIBEXECDIR "/devices");
 967         if (dir_from == NULL)
 968                 return;
 969         copy_dev_dir(udev, dir_from, dir, 8);
 970         closedir(dir_from);
 971 }
 972
 973 static void static_dev_create(struct udev *udev)
 974 {
 975         DIR *dir;
 976
 977         dir = opendir(udev_get_dev_path(udev));
 978         if (dir == NULL)
 979                 return;
 980
 981         static_dev_create_links(udev, dir);
 982         static_dev_create_from_devices(udev, dir);
 983
 984         closedir(dir);
 985 }
 986
 987 static int mem_size_mb(void)
 988 {
 989         FILE *f;
 990         char buf[4096];
 991         long int memsize = -1;
 992
 993         f = fopen("/proc/meminfo", "r");
 994         if (f == NULL)
 995                 return -1;
 996
 997         while (fgets(buf, sizeof(buf), f) != NULL) {
 998                 long int value;
 999
1000                 if (sscanf(buf, "MemTotal: %ld kB", &value) == 1) {
1001                         memsize = value / 1024;
1002                         break;
1003                 }
1004         }
1005
1006         fclose(f);
1007         return memsize;
1008 }
1009
1010 static int convert_db(struct udev *udev)
1011 {
1012         char filename[UTIL_PATH_SIZE];
1013         FILE *f;
1014         struct udev_enumerate *udev_enumerate;
1015         struct udev_list_entry *list_entry;
1016
1017         /* current database */
1018         util_strscpyl(filename, sizeof(filename), udev_get_run_path(udev), "/data", NULL);
1019         if (access(filename, F_OK) >= 0)
1020                 return 0;
1021
1022         /* make sure we do not get here again */
1023         util_create_path(udev, filename);
1024         mkdir(filename, 0755);
1025
1026         /* old database */
1027         util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev), "/.udev/db", NULL);
1028         if (access(filename, F_OK) < 0)
1029                 return 0;
1030
1031         f = fopen("/dev/kmsg", "w");
1032         if (f != NULL) {
1033                 fprintf(f, "<30>udev[%u]: converting old udev database\n", getpid());
1034                 fclose(f);
1035         }
1036
1037         udev_enumerate = udev_enumerate_new(udev);
1038         if (udev_enumerate == NULL)
1039                 return -1;
1040         udev_enumerate_scan_devices(udev_enumerate);
1041         udev_list_entry_foreach(list_entry, udev_enumerate_get_list_entry(udev_enumerate)) {
1042                 struct udev_device *device;
1043
1044                 device = udev_device_new_from_syspath(udev, udev_list_entry_get_name(list_entry));
1045                 if (device == NULL)
1046                         continue;
1047
1048                 /* try to find the old database for devices without a current one */
1049                 if (udev_device_read_db(device, NULL) < 0) {
1050                         bool have_db;
1051                         const char *id;
1052                         struct stat stats;
1053                         char devpath[UTIL_PATH_SIZE];
1054                         char from[UTIL_PATH_SIZE];
1055
1056                         have_db = false;
1057
1058                         /* find database in old location */
1059                         id = udev_device_get_id_filename(device);
1060                         util_strscpyl(from, sizeof(from), udev_get_dev_path(udev), "/.udev/db/", id, NULL);
1061                         if (lstat(from, &stats) == 0) {
1062                                 if (!have_db) {
1063                                         udev_device_read_db(device, from);
1064                                         have_db = true;
1065                                 }
1066                                 unlink(from);
1067                         }
1068
1069                         /* find old database with $subsys:$sysname name */
1070                         util_strscpyl(from, sizeof(from), udev_get_dev_path(udev),
1071                                      "/.udev/db/", udev_device_get_subsystem(device), ":",
1072                                      udev_device_get_sysname(device), NULL);
1073                         if (lstat(from, &stats) == 0) {
1074                                 if (!have_db) {
1075                                         udev_device_read_db(device, from);
1076                                         have_db = true;
1077                                 }
1078                                 unlink(from);
1079                         }
1080
1081                         /* find old database with the encoded devpath name */
1082                         util_path_encode(udev_device_get_devpath(device), devpath, sizeof(devpath));
1083                         util_strscpyl(from, sizeof(from), udev_get_dev_path(udev), "/.udev/db/", devpath, NULL);
1084                         if (lstat(from, &stats) == 0) {
1085                                 if (!have_db) {
1086                                         udev_device_read_db(device, from);
1087                                         have_db = true;
1088                                 }
1089                                 unlink(from);
1090                         }
1091
1092                         /* write out new database */
1093                         if (have_db)
1094                                 udev_device_update_db(device);
1095                 }
1096                 udev_device_unref(device);
1097         }
1098         udev_enumerate_unref(udev_enumerate);
1099         return 0;
1100 }
1101
1102 int main(int argc, char *argv[])
1103 {
1104         struct udev *udev;
1105         int fd;
1106         FILE *f;
1107         sigset_t mask;
1108         int daemonize = false;
1109         int resolve_names = 1;
1110         static const struct option options[] = {
1111                 { "daemon", no_argument, NULL, 'd' },
1112                 { "debug", no_argument, NULL, 'D' },
1113                 { "children-max", required_argument, NULL, 'c' },
1114                 { "exec-delay", required_argument, NULL, 'e' },
1115                 { "resolve-names", required_argument, NULL, 'N' },
1116                 { "help", no_argument, NULL, 'h' },
1117                 { "version", no_argument, NULL, 'V' },
1118                 {}
1119         };
1120         int fd_ctrl = -1;
1121         int fd_netlink = -1;
1122         int fd_worker = -1;
1123         struct epoll_event ep_ctrl, ep_inotify, ep_signal, ep_netlink, ep_worker;
1124         struct udev_ctrl_connection *ctrl_conn = NULL;
1125         int rc = 1;
1126
1127         udev = udev_new();
1128         if (udev == NULL)
1129                 goto exit;
1130
1131         udev_log_init("udevd");
1132         udev_set_log_fn(udev, log_fn);
1133         info(udev, "version %s\n", VERSION);
1134         udev_selinux_init(udev);
1135
1136         /* make sure, that our runtime dir exists and is writable */
1137         if (utimensat(AT_FDCWD, udev_get_run_config_path(udev), NULL, 0) < 0) {
1138                 /* try to create our own subdirectory, do not create parent directories */
1139                 mkdir(udev_get_run_config_path(udev), 0755);
1140
1141                 if (utimensat(AT_FDCWD, udev_get_run_config_path(udev), NULL, 0) >= 0) {
1142                         /* directory seems writable now */
1143                         udev_set_run_path(udev, udev_get_run_config_path(udev));
1144                 } else {
1145                         /* fall back to /dev/.udev */
1146                         char filename[UTIL_PATH_SIZE];
1147
1148                         util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev), "/.udev", NULL);
1149                         if (udev_set_run_path(udev, filename) == NULL)
1150                                 goto exit;
1151                         mkdir(udev_get_run_path(udev), 0755);
1152                         err(udev, "error: runtime directory '%s' not writable, for now falling back to '%s'",
1153                             udev_get_run_config_path(udev), udev_get_run_path(udev));
1154                 }
1155         }
1156         /* relabel runtime dir only if it resides below /dev */
1157         if (strncmp(udev_get_run_path(udev), udev_get_dev_path(udev), strlen(udev_get_dev_path(udev))) == 0)
1158                 udev_selinux_lsetfilecon(udev, udev_get_run_path(udev), 0755);
1159         info(udev, "runtime dir '%s'\n", udev_get_run_path(udev));
1160
1161         for (;;) {
1162                 int option;
1163
1164                 option = getopt_long(argc, argv, "c:deDtN:hV", options, NULL);
1165                 if (option == -1)
1166                         break;
1167
1168                 switch (option) {
1169                 case 'd':
1170                         daemonize = true;
1171                         break;
1172                 case 'c':
1173                         children_max = strtoul(optarg, NULL, 0);
1174                         break;
1175                 case 'e':
1176                         exec_delay = strtoul(optarg, NULL, 0);
1177                         break;
1178                 case 'D':
1179                         debug = true;
1180                         if (udev_get_log_priority(udev) < LOG_INFO)
1181                                 udev_set_log_priority(udev, LOG_INFO);
1182                         break;
1183                 case 'N':
1184                         if (strcmp (optarg, "early") == 0) {
1185                                 resolve_names = 1;
1186                         } else if (strcmp (optarg, "late") == 0) {
1187                                 resolve_names = 0;
1188                         } else if (strcmp (optarg, "never") == 0) {
1189                                 resolve_names = -1;
1190                         } else {
1191                                 fprintf(stderr, "resolve-names must be early, late or never\n");
1192                                 err(udev, "resolve-names must be early, late or never\n");
1193                                 goto exit;
1194                         }
1195                         break;
1196                 case 'h':
1197                         printf("Usage: udevd OPTIONS\n"
1198                                "  --daemon\n"
1199                                "  --debug\n"
1200                                "  --children-max=<maximum number of workers>\n"
1201                                "  --exec-delay=<seconds to wait before executing RUN=>\n"
1202                                "  --resolve-names=early|late|never\n"
1203                                "  --version\n"
1204                                "  --help\n"
1205                                "\n");
1206                         goto exit;
1207                 case 'V':
1208                         printf("%s\n", VERSION);
1209                         goto exit;
1210                 default:
1211                         goto exit;
1212                 }
1213         }
1214
1215         /*
1216          * read the kernel commandline, in case we need to get into debug mode
1217          *   udev.log-priority=<level>              syslog priority
1218          *   udev.children-max=<number of workers>  events are fully serialized if set to 1
1219          *
1220          */
1221         f = fopen("/proc/cmdline", "r");
1222         if (f != NULL) {
1223                 char cmdline[4096];
1224
1225                 if (fgets(cmdline, sizeof(cmdline), f) != NULL) {
1226                         char *pos;
1227
1228                         pos = strstr(cmdline, "udev.log-priority=");
1229                         if (pos != NULL) {
1230                                 pos += strlen("udev.log-priority=");
1231                                 udev_set_log_priority(udev, util_log_priority(pos));
1232                         }
1233
1234                         pos = strstr(cmdline, "udev.children-max=");
1235                         if (pos != NULL) {
1236                                 pos += strlen("udev.children-max=");
1237                                 children_max = strtoul(pos, NULL, 0);
1238                         }
1239
1240                         pos = strstr(cmdline, "udev.exec-delay=");
1241                         if (pos != NULL) {
1242                                 pos += strlen("udev.exec-delay=");
1243                                 exec_delay = strtoul(pos, NULL, 0);
1244                         }
1245                 }
1246                 fclose(f);
1247         }
1248
1249         if (getuid() != 0) {
1250                 fprintf(stderr, "root privileges required\n");
1251                 err(udev, "root privileges required\n");
1252                 goto exit;
1253         }
1254
1255         /* set umask before creating any file/directory */
1256         chdir("/");
1257         umask(022);
1258
1259         /* create standard links, copy static nodes, create nodes from modules */
1260         static_dev_create(udev);
1261         static_dev_create_from_modules(udev);
1262
1263         /* before opening new files, make sure std{in,out,err} fds are in a sane state */
1264         fd = open("/dev/null", O_RDWR);
1265         if (fd < 0) {
1266                 fprintf(stderr, "cannot open /dev/null\n");
1267                 err(udev, "cannot open /dev/null\n");
1268         }
1269         if (write(STDOUT_FILENO, 0, 0) < 0)
1270                 dup2(fd, STDOUT_FILENO);
1271         if (write(STDERR_FILENO, 0, 0) < 0)
1272                 dup2(fd, STDERR_FILENO);
1273
1274         /* udevadm control socket */
1275         if (sd_listen_fds(true) == 1 && sd_is_socket(SD_LISTEN_FDS_START, AF_LOCAL, SOCK_SEQPACKET, -1))
1276                 udev_ctrl = udev_ctrl_new_from_fd(udev, SD_LISTEN_FDS_START);
1277         else
1278                 udev_ctrl = udev_ctrl_new_from_socket(udev, UDEV_CTRL_SOCK_PATH);
1279         if (udev_ctrl == NULL) {
1280                 fprintf(stderr, "error initializing udev control socket");
1281                 err(udev, "error initializing udev control socket");
1282                 rc = 1;
1283                 goto exit;
1284         }
1285         if (udev_ctrl_enable_receiving(udev_ctrl) < 0) {
1286                 fprintf(stderr, "error binding udev control socket\n");
1287                 err(udev, "error binding udev control socket\n");
1288                 rc = 1;
1289                 goto exit;
1290         }
1291         fd_ctrl = udev_ctrl_get_fd(udev_ctrl);
1292
1293         monitor = udev_monitor_new_from_netlink(udev, "kernel");
1294         if (monitor == NULL || udev_monitor_enable_receiving(monitor) < 0) {
1295                 fprintf(stderr, "error initializing netlink socket\n");
1296                 err(udev, "error initializing netlink socket\n");
1297                 rc = 3;
1298                 goto exit;
1299         }
1300         udev_monitor_set_receive_buffer_size(monitor, 128*1024*1024);
1301         fd_netlink = udev_monitor_get_fd(monitor);
1302
1303         if (daemonize) {
1304                 pid_t pid;
1305
1306                 pid = fork();
1307                 switch (pid) {
1308                 case 0:
1309                         break;
1310                 case -1:
1311                         err(udev, "fork of daemon failed: %m\n");
1312                         rc = 4;
1313                         goto exit;
1314                 default:
1315                         rc = 0;
1316                         goto exit;
1317                 }
1318         } else {
1319                 sd_notify(1, "READY=1");
1320         }
1321
1322         fd_inotify = udev_watch_init(udev);
1323         if (fd_inotify < 0) {
1324                 fprintf(stderr, "error initializing inotify\n");
1325                 err(udev, "error initializing inotify\n");
1326                 rc = 4;
1327                 goto exit;
1328         }
1329
1330         if (udev_get_rules_path(udev) != NULL) {
1331                 inotify_add_watch(fd_inotify, udev_get_rules_path(udev),
1332                                   IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
1333         } else {
1334                 char filename[UTIL_PATH_SIZE];
1335                 struct stat statbuf;
1336
1337                 inotify_add_watch(fd_inotify, LIBEXECDIR "/rules.d",
1338                                   IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
1339                 inotify_add_watch(fd_inotify, SYSCONFDIR "/udev/rules.d",
1340                                   IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
1341
1342                 /* watch dynamic rules directory */
1343                 util_strscpyl(filename, sizeof(filename), udev_get_run_path(udev), "/rules.d", NULL);
1344                 if (stat(filename, &statbuf) != 0) {
1345                         util_create_path(udev, filename);
1346                         mkdir(filename, 0755);
1347                 }
1348                 inotify_add_watch(fd_inotify, filename,
1349                                   IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
1350         }
1351         udev_watch_restore(udev);
1352
1353         /* block and listen to all signals on signalfd */
1354         sigfillset(&mask);
1355         sigprocmask(SIG_SETMASK, &mask, &orig_sigmask);
1356         fd_signal = signalfd(-1, &mask, SFD_CLOEXEC);
1357         if (fd_signal < 0) {
1358                 fprintf(stderr, "error getting signalfd\n");
1359                 err(udev, "error getting signalfd\n");
1360                 rc = 5;
1361                 goto exit;
1362         }
1363
1364         /* unnamed socket from workers to the main daemon */
1365         if (socketpair(AF_LOCAL, SOCK_DGRAM|SOCK_CLOEXEC, 0, worker_watch) < 0) {
1366                 fprintf(stderr, "error getting socketpair\n");
1367                 err(udev, "error getting socketpair\n");
1368                 rc = 6;
1369                 goto exit;
1370         }
1371         fd_worker = worker_watch[READ_END];
1372
1373         rules = udev_rules_new(udev, resolve_names);
1374         if (rules == NULL) {
1375                 err(udev, "error reading rules\n");
1376                 goto exit;
1377         }
1378
1379         udev_queue_export = udev_queue_export_new(udev);
1380         if (udev_queue_export == NULL) {
1381                 err(udev, "error creating queue file\n");
1382                 goto exit;
1383         }
1384
1385         memset(&ep_ctrl, 0, sizeof(struct epoll_event));
1386         ep_ctrl.events = EPOLLIN;
1387         ep_ctrl.data.fd = fd_ctrl;
1388         memset(&ep_inotify, 0, sizeof(struct epoll_event));
1389         ep_inotify.events = EPOLLIN;
1390         ep_inotify.data.fd = fd_inotify;
1391         memset(&ep_signal, 0, sizeof(struct epoll_event));
1392         ep_signal.events = EPOLLIN;
1393         ep_signal.data.fd = fd_signal;
1394         memset(&ep_netlink, 0, sizeof(struct epoll_event));
1395         ep_netlink.events = EPOLLIN;
1396         ep_netlink.data.fd = fd_netlink;
1397         memset(&ep_worker, 0, sizeof(struct epoll_event));
1398         ep_worker.events = EPOLLIN;
1399         ep_worker.data.fd = fd_worker;
1400         fd_ep = epoll_create1(EPOLL_CLOEXEC);
1401         if (fd_ep < 0) {
1402                 err(udev, "error creating epoll fd: %m\n");
1403                 goto exit;
1404         }
1405         if (epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_ctrl, &ep_ctrl) < 0 ||
1406             epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_inotify, &ep_inotify) < 0 ||
1407             epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_signal, &ep_signal) < 0 ||
1408             epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_netlink, &ep_netlink) < 0 ||
1409             epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_worker, &ep_worker) < 0) {
1410                 err(udev, "fail to add fds to epoll: %m\n");
1411                 goto exit;
1412         }
1413
1414         /* if needed, convert old database from earlier udev version */
1415         convert_db(udev);
1416
1417         if (!debug) {
1418                 dup2(fd, STDIN_FILENO);
1419                 dup2(fd, STDOUT_FILENO);
1420                 dup2(fd, STDERR_FILENO);
1421         }
1422         if (fd > STDERR_FILENO)
1423                 close(fd);
1424
1425         setsid();
1426
1427         f = fopen("/dev/kmsg", "w");
1428         if (f != NULL) {
1429                 fprintf(f, "<30>udev[%u]: starting version " VERSION "\n", getpid());
1430                 fclose(f);
1431         }
1432
1433         fd = open("/proc/self/oom_score_adj", O_RDWR);
1434         if (fd < 0) {
1435                 /* Fallback to old interface */
1436                 fd = open("/proc/self/oom_adj", O_RDWR);
1437                 if (fd < 0) {
1438                         err(udev, "error disabling OOM: %m\n");
1439                 } else {
1440                         /* OOM_DISABLE == -17 */
1441                         write(fd, "-17", 3);
1442                         close(fd);
1443                 }
1444         } else {
1445                 write(fd, "-1000", 5);
1446                 close(fd);
1447         }
1448
1449         if (children_max <= 0) {
1450                 int memsize = mem_size_mb();
1451
1452                 /* set value depending on the amount of RAM */
1453                 if (memsize > 0)
1454                         children_max = 128 + (memsize / 8);
1455                 else
1456                         children_max = 128;
1457         }
1458         info(udev, "set children_max to %u\n", children_max);
1459
1460         udev_rules_apply_static_dev_perms(rules);
1461
1462         udev_list_init(&event_list);
1463         udev_list_init(&worker_list);
1464
1465         for (;;) {
1466                 struct epoll_event ev[8];
1467                 int fdcount;
1468                 int timeout;
1469                 bool is_worker, is_signal, is_inotify, is_netlink, is_ctrl;
1470                 int i;
1471
1472                 if (udev_exit) {
1473                         /* close sources of new events and discard buffered events */
1474                         if (fd_ctrl >= 0) {
1475                                 epoll_ctl(fd_ep, EPOLL_CTL_DEL, fd_ctrl, NULL);
1476                                 fd_ctrl = -1;
1477                         }
1478                         if (monitor != NULL) {
1479                                 epoll_ctl(fd_ep, EPOLL_CTL_DEL, fd_netlink, NULL);
1480                                 udev_monitor_unref(monitor);
1481                                 monitor = NULL;
1482                         }
1483                         if (fd_inotify >= 0) {
1484                                 epoll_ctl(fd_ep, EPOLL_CTL_DEL, fd_inotify, NULL);
1485                                 close(fd_inotify);
1486                                 fd_inotify = -1;
1487                         }
1488
1489                         /* discard queued events and kill workers */
1490                         event_queue_cleanup(udev, EVENT_QUEUED);
1491                         worker_kill(udev, 0);
1492
1493                         /* exit after all has cleaned up */
1494                         if (udev_list_is_empty(&event_list) && udev_list_is_empty(&worker_list))
1495                                 break;
1496
1497                         /* timeout at exit for workers to finish */
1498                         timeout = 60 * 1000;
1499                 } else if (udev_list_is_empty(&event_list) && children > 2) {
1500                         /* set timeout to kill idle workers */
1501                         timeout = 3 * 1000;
1502                 } else {
1503                         timeout = -1;
1504                 }
1505                 fdcount = epoll_wait(fd_ep, ev, ARRAY_SIZE(ev), timeout);
1506                 if (fdcount < 0)
1507                         continue;
1508
1509                 if (fdcount == 0) {
1510                         if (udev_exit) {
1511                                 info(udev, "timeout, giving up waiting for workers to finish\n");
1512                                 break;
1513                         }
1514
1515                         /* timeout - kill idle workers */
1516                         worker_kill(udev, 2);
1517                 }
1518
1519                 is_worker = is_signal = is_inotify = is_netlink = is_ctrl = false;
1520                 for (i = 0; i < fdcount; i++) {
1521                         if (ev[i].data.fd == fd_worker && ev[i].events & EPOLLIN)
1522                                 is_worker = true;
1523                         else if (ev[i].data.fd == fd_netlink && ev[i].events & EPOLLIN)
1524                                 is_netlink = true;
1525                         else if (ev[i].data.fd == fd_signal && ev[i].events & EPOLLIN)
1526                                 is_signal = true;
1527                         else if (ev[i].data.fd == fd_inotify && ev[i].events & EPOLLIN)
1528                                 is_inotify = true;
1529                         else if (ev[i].data.fd == fd_ctrl && ev[i].events & EPOLLIN)
1530                                 is_ctrl = true;
1531                 }
1532
1533                 /* event has finished */
1534                 if (is_worker)
1535                         worker_returned(fd_worker);
1536
1537                 if (is_netlink) {
1538                         struct udev_device *dev;
1539
1540                         dev = udev_monitor_receive_device(monitor);
1541                         if (dev != NULL)
1542                                 if (event_queue_insert(dev) < 0)
1543                                         udev_device_unref(dev);
1544                 }
1545
1546                 /* start new events */
1547                 if (!udev_list_is_empty(&event_list) && !udev_exit && !stop_exec_queue)
1548                         event_queue_start(udev);
1549
1550                 if (is_signal) {
1551                         struct signalfd_siginfo fdsi;
1552                         ssize_t size;
1553
1554                         size = read(fd_signal, &fdsi, sizeof(struct signalfd_siginfo));
1555                         if (size == sizeof(struct signalfd_siginfo))
1556                                 handle_signal(udev, fdsi.ssi_signo);
1557                 }
1558
1559                 /* we are shutting down, the events below are not handled anymore */
1560                 if (udev_exit)
1561                         continue;
1562
1563                 /* device node and rules directory inotify watch */
1564                 if (is_inotify)
1565                         handle_inotify(udev);
1566
1567                 /*
1568                  * This needs to be after the inotify handling, to make sure,
1569                  * that the ping is send back after the possibly generated
1570                  * "change" events by the inotify device node watch.
1571                  *
1572                  * A single time we may receive a client connection which we need to
1573                  * keep open to block the client. It will be closed right before we
1574                  * exit.
1575                  */
1576                 if (is_ctrl)
1577                         ctrl_conn = handle_ctrl_msg(udev_ctrl);
1578
1579                 /* rules changed, set by inotify or a HUP signal */
1580                 if (reload_config) {
1581                         struct udev_rules *rules_new;
1582
1583                         worker_kill(udev, 0);
1584                         rules_new = udev_rules_new(udev, resolve_names);
1585                         if (rules_new != NULL) {
1586                                 udev_rules_unref(rules);
1587                                 rules = rules_new;
1588                         }
1589                         reload_config = 0;
1590                 }
1591         }
1592
1593         udev_queue_export_cleanup(udev_queue_export);
1594         rc = 0;
1595 exit:
1596         if (fd_ep >= 0)
1597                 close(fd_ep);
1598         worker_list_cleanup(udev);
1599         event_queue_cleanup(udev, EVENT_UNDEF);
1600         udev_rules_unref(rules);
1601         if (fd_signal >= 0)
1602                 close(fd_signal);
1603         if (worker_watch[READ_END] >= 0)
1604                 close(worker_watch[READ_END]);
1605         if (worker_watch[WRITE_END] >= 0)
1606                 close(worker_watch[WRITE_END]);
1607         udev_monitor_unref(monitor);
1608         udev_queue_export_unref(udev_queue_export);
1609         udev_ctrl_connection_unref(ctrl_conn);
1610         udev_ctrl_unref(udev_ctrl);
1611         udev_selinux_exit(udev);
1612         udev_unref(udev);
1613         udev_log_close();
1614         return rc;
1615 }