udev/udevd.c

   1 /*
   2  * Copyright (C) 2004-2008 Kay Sievers <kay.sievers@vrfy.org>
   3  * Copyright (C) 2004 Chris Friesen <chris_friesen@sympatico.ca>
   4  *
   5  * This program is free software: you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation, either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 #include <stddef.h>
  20 #include <signal.h>
  21 #include <unistd.h>
  22 #include <errno.h>
  23 #include <stdio.h>
  24 #include <stdlib.h>
  25 #include <string.h>
  26 #include <ctype.h>
  27 #include <fcntl.h>
  28 #include <time.h>
  29 #include <getopt.h>
  30 #include <dirent.h>
  31 #include <sys/select.h>
  32 #include <sys/poll.h>
  33 #include <sys/wait.h>
  34 #include <sys/stat.h>
  35 #include <sys/ioctl.h>
  36 #ifdef HAVE_INOTIFY
  37 #include <sys/inotify.h>
  38 #endif
  39
  40 #include "udev.h"
  41
  42 #define UDEVD_PRIORITY                  -4
  43 #define UDEV_PRIORITY                   -2
  44
  45 /* maximum limit of forked childs */
  46 #define UDEVD_MAX_CHILDS                256
  47
  48 static int debug;
  49
  50 static void log_fn(struct udev *udev, int priority,
  51                    const char *file, int line, const char *fn,
  52                    const char *format, va_list args)
  53 {
  54         if (debug) {
  55                 fprintf(stderr, "[%d] %s: ", (int) getpid(), fn);
  56                 vfprintf(stderr, format, args);
  57         } else {
  58                 vsyslog(priority, format, args);
  59         }
  60 }
  61
  62 static int debug_trace;
  63 static struct udev_rules *rules;
  64 static struct udev_ctrl *udev_ctrl;
  65 static struct udev_monitor *kernel_monitor;
  66 static int inotify_fd = -1;
  67 static volatile int sigchilds_waiting;
  68 static volatile int udev_exit;
  69 static volatile int reload_config;
  70 static volatile int signal_received;
  71 static int run_exec_q;
  72 static int stop_exec_q;
  73 static int max_childs;
  74 static int childs;
  75 static struct udev_list_node event_list;
  76
  77 enum event_state {
  78         EVENT_QUEUED,
  79         EVENT_FINISHED,
  80         EVENT_FAILED,
  81 };
  82
  83 static struct udev_event *node_to_event(struct udev_list_node *node)
  84 {
  85         char *event;
  86
  87         event = (char *)node;
  88         event -= offsetof(struct udev_event, node);
  89         return (struct udev_event *)event;
  90 }
  91
  92 static void export_event_state(struct udev_event *event, enum event_state state)
  93 {
  94         char filename[UTIL_PATH_SIZE];
  95         char filename_failed[UTIL_PATH_SIZE];
  96         size_t start;
  97
  98         /* location of queue file */
  99         snprintf(filename, sizeof(filename), "%s/.udev/queue/%llu",
 100                  udev_get_dev_path(event->udev), udev_device_get_seqnum(event->dev));
 101
 102         /* location of failed file */
 103         util_strlcpy(filename_failed, udev_get_dev_path(event->udev), sizeof(filename_failed));
 104         util_strlcat(filename_failed, "/", sizeof(filename_failed));
 105         start = util_strlcat(filename_failed, ".udev/failed/", sizeof(filename_failed));
 106         util_strlcat(filename_failed, udev_device_get_devpath(event->dev), sizeof(filename_failed));
 107         util_path_encode(&filename_failed[start], sizeof(filename_failed) - start);
 108
 109         switch (state) {
 110         case EVENT_QUEUED:
 111                 if(unlink(filename_failed) == 0)
 112                         util_delete_path(event->udev, filename_failed);
 113                 util_create_path(event->udev, filename);
 114                 udev_selinux_setfscreatecon(event->udev, filename, S_IFLNK);
 115                 symlink(udev_device_get_devpath(event->dev), filename);
 116                 udev_selinux_resetfscreatecon(event->udev);
 117                 break;
 118         case EVENT_FINISHED:
 119                 if (udev_device_get_devpath_old(event->dev) != NULL) {
 120                         /* "move" event - rename failed file to current name, do not delete failed */
 121                         char filename_failed_old[UTIL_PATH_SIZE];
 122
 123                         util_strlcpy(filename_failed_old, udev_get_dev_path(event->udev), sizeof(filename_failed_old));
 124                         util_strlcat(filename_failed_old, "/", sizeof(filename_failed_old));
 125                         start = util_strlcat(filename_failed_old, ".udev/failed/", sizeof(filename_failed_old));
 126                         util_strlcat(filename_failed_old, udev_device_get_devpath_old(event->dev), sizeof(filename_failed_old));
 127                         util_path_encode(&filename_failed_old[start], sizeof(filename) - start);
 128
 129                         if (rename(filename_failed_old, filename_failed) == 0)
 130                                 info(event->udev, "renamed devpath, moved failed state of '%s' to %s'\n",
 131                                      udev_device_get_devpath_old(event->dev), udev_device_get_devpath(event->dev));
 132                 } else {
 133                         if (unlink(filename_failed) == 0)
 134                                 util_delete_path(event->udev, filename_failed);
 135                 }
 136
 137                 unlink(filename);
 138
 139                 /* clean up possibly empty queue directory */
 140                 if (udev_list_is_empty(&event_list))
 141                         util_delete_path(event->udev, filename);
 142                 break;
 143         case EVENT_FAILED:
 144                 /* move failed event to the failed directory */
 145                 util_create_path(event->udev, filename_failed);
 146                 rename(filename, filename_failed);
 147
 148                 /* clean up possibly empty queue directory */
 149                 if (udev_list_is_empty(&event_list))
 150                         util_delete_path(event->udev, filename);
 151                 break;
 152         }
 153
 154         return;
 155 }
 156
 157 static void event_queue_delete(struct udev_event *event)
 158 {
 159         udev_list_node_remove(&event->node);
 160
 161         /* mark as failed, if "add" event returns non-zero */
 162         if (event->exitstatus && strcmp(udev_device_get_action(event->dev), "add") == 0)
 163                 export_event_state(event, EVENT_FAILED);
 164         else
 165                 export_event_state(event, EVENT_FINISHED);
 166
 167         udev_device_unref(event->dev);
 168         udev_event_unref(event);
 169 }
 170
 171 static void asmlinkage event_sig_handler(int signum)
 172 {
 173         if (signum == SIGALRM)
 174                 exit(1);
 175 }
 176
 177 static void event_fork(struct udev_event *event)
 178 {
 179         pid_t pid;
 180         struct sigaction act;
 181         int err;
 182
 183         if (debug_trace) {
 184                 event->trace = 1;
 185                 fprintf(stderr, "fork %s (%llu)\n",
 186                        udev_device_get_syspath(event->dev),
 187                        udev_device_get_seqnum(event->dev));
 188         }
 189
 190         pid = fork();
 191         switch (pid) {
 192         case 0:
 193                 /* child */
 194                 udev_monitor_unref(kernel_monitor);
 195                 udev_ctrl_unref(udev_ctrl);
 196                 if (inotify_fd >= 0)
 197                         close(inotify_fd);
 198                 logging_close();
 199                 logging_init("udevd-event");
 200                 setpriority(PRIO_PROCESS, 0, UDEV_PRIORITY);
 201
 202                 /* set signal handlers */
 203                 memset(&act, 0x00, sizeof(act));
 204                 act.sa_handler = (void (*)(int)) event_sig_handler;
 205                 sigemptyset (&act.sa_mask);
 206                 act.sa_flags = 0;
 207                 sigaction(SIGALRM, &act, NULL);
 208
 209                 /* reset to default */
 210                 act.sa_handler = SIG_DFL;
 211                 sigaction(SIGINT, &act, NULL);
 212                 sigaction(SIGTERM, &act, NULL);
 213                 sigaction(SIGCHLD, &act, NULL);
 214                 sigaction(SIGHUP, &act, NULL);
 215
 216                 /* set timeout to prevent hanging processes */
 217                 alarm(UDEV_EVENT_TIMEOUT);
 218
 219                 /* apply rules, create node, symlinks */
 220                 err = udev_event_execute_rules(event, rules);
 221
 222                 /* rules may change/disable the timeout */
 223                 if (udev_device_get_event_timeout(event->dev) >= 0)
 224                         alarm(udev_device_get_event_timeout(event->dev));
 225
 226                 /* execute RUN= */
 227                 if (err == 0 && !event->ignore_device && udev_get_run(event->udev))
 228                         udev_event_execute_run(event);
 229
 230                 info(event->udev, "seq %llu exit with %i\n", udev_device_get_seqnum(event->dev), err);
 231                 logging_close();
 232                 if (err != 0)
 233                         exit(1);
 234                 exit(0);
 235         case -1:
 236                 err(event->udev, "fork of child failed: %m\n");
 237                 event_queue_delete(event);
 238                 break;
 239         default:
 240                 /* get SIGCHLD in main loop */
 241                 info(event->udev, "seq %llu forked, pid [%d], '%s' '%s', %ld seconds old\n",
 242                      udev_device_get_seqnum(event->dev),
 243                      pid,
 244                      udev_device_get_action(event->dev),
 245                      udev_device_get_subsystem(event->dev),
 246                      time(NULL) - event->queue_time);
 247                 event->pid = pid;
 248                 childs++;
 249         }
 250 }
 251
 252 static void event_queue_insert(struct udev_event *event)
 253 {
 254         char filename[UTIL_PATH_SIZE];
 255         int fd;
 256
 257         event->queue_time = time(NULL);
 258
 259         export_event_state(event, EVENT_QUEUED);
 260         info(event->udev, "seq %llu queued, '%s' '%s'\n", udev_device_get_seqnum(event->dev),
 261              udev_device_get_action(event->dev), udev_device_get_subsystem(event->dev));
 262
 263         util_strlcpy(filename, udev_get_dev_path(event->udev), sizeof(filename));
 264         util_strlcat(filename, "/.udev/uevent_seqnum", sizeof(filename));
 265         fd = open(filename, O_WRONLY|O_TRUNC|O_CREAT, 0644);
 266         if (fd >= 0) {
 267                 char str[32];
 268                 int len;
 269
 270                 len = sprintf(str, "%llu\n", udev_device_get_seqnum(event->dev));
 271                 write(fd, str, len);
 272                 close(fd);
 273         }
 274
 275
 276         udev_list_node_append(&event->node, &event_list);
 277         run_exec_q = 1;
 278
 279         /* run all events with a timeout set immediately */
 280         if (udev_device_get_timeout(event->dev) > 0) {
 281                 event_fork(event);
 282                 return;
 283         }
 284 }
 285
 286 static int mem_size_mb(void)
 287 {
 288         FILE* f;
 289         char buf[4096];
 290         long int memsize = -1;
 291
 292         f = fopen("/proc/meminfo", "r");
 293         if (f == NULL)
 294                 return -1;
 295
 296         while (fgets(buf, sizeof(buf), f) != NULL) {
 297                 long int value;
 298
 299                 if (sscanf(buf, "MemTotal: %ld kB", &value) == 1) {
 300                         memsize = value / 1024;
 301                         break;
 302                 }
 303         }
 304
 305         fclose(f);
 306         return memsize;
 307 }
 308
 309 static int compare_devpath(const char *running, const char *waiting)
 310 {
 311         int i = 0;
 312
 313         while (running[i] != '\0' && running[i] == waiting[i])
 314                 i++;
 315
 316         /* identical device event found */
 317         if (running[i] == '\0' && waiting[i] == '\0')
 318                 return 1;
 319
 320         /* parent device event found */
 321         if (running[i] == '\0' && waiting[i] == '/')
 322                 return 2;
 323
 324         /* child device event found */
 325         if (running[i] == '/' && waiting[i] == '\0')
 326                 return 3;
 327
 328         /* no matching event */
 329         return 0;
 330 }
 331
 332 /* lookup event for identical, parent, child, or physical device */
 333 static int devpath_busy(struct udev_event *event)
 334 {
 335         struct udev_list_node *loop;
 336
 337         if (event->delaying_seqnum > 0) {
 338         }
 339         /* check if queue contains events we depend on */
 340         udev_list_node_foreach(loop, &event_list) {
 341                 struct udev_event *loop_event = node_to_event(loop);
 342
 343                 /* we already found a later event, earlier can not block us, no need to check again */
 344                 if (udev_device_get_seqnum(loop_event->dev) < event->delaying_seqnum)
 345                         continue;
 346
 347                 /* event we checked earlier still exists, no need to check again */
 348                 if (udev_device_get_seqnum(loop_event->dev) == event->delaying_seqnum)
 349                         return 2;
 350
 351                 /* found ourself, no later event can block us */
 352                 if (udev_device_get_seqnum(loop_event->dev) >= udev_device_get_seqnum(event->dev))
 353                         break;
 354
 355                 /* check our old name */
 356                 if (udev_device_get_devpath_old(event->dev) != NULL)
 357                         if (strcmp(udev_device_get_devpath(loop_event->dev), udev_device_get_devpath_old(event->dev)) == 0) {
 358                                 event->delaying_seqnum = udev_device_get_seqnum(loop_event->dev);
 359                                 return 3;
 360                         }
 361
 362                 /* check identical, parent, or child device event */
 363                 if (compare_devpath(udev_device_get_devpath(loop_event->dev), udev_device_get_devpath(event->dev)) != 0) {
 364                         dbg(event->udev, "%llu, device event still pending %llu (%s)\n",
 365                             udev_device_get_seqnum(event->dev),
 366                             udev_device_get_seqnum(loop_event->dev),
 367                             udev_device_get_devpath(loop_event->dev));
 368                         event->delaying_seqnum = udev_device_get_seqnum(loop_event->dev);
 369                         return 4;
 370                 }
 371
 372                 /* check for our major:minor number */
 373                 if (major(udev_device_get_devnum(event->dev)) > 0 &&
 374                     udev_device_get_devnum(loop_event->dev) == udev_device_get_devnum(event->dev) &&
 375                     strcmp(udev_device_get_subsystem(event->dev), udev_device_get_subsystem(loop_event->dev)) == 0) {
 376                         dbg(event->udev, "%llu, device event still pending %llu (%d:%d)\n",
 377                             udev_device_get_seqnum(event->dev),
 378                             udev_device_get_seqnum(loop_event->dev),
 379                             major(udev_device_get_devnum(loop_event->dev)), minor(udev_device_get_devnum(loop_event->dev)));
 380                         event->delaying_seqnum = udev_device_get_seqnum(loop_event->dev);
 381                         return 5;
 382                 }
 383
 384                 /* check physical device event (special case of parent) */
 385                 if (udev_device_get_physdevpath(event->dev) != NULL &&
 386                     strcmp(udev_device_get_action(event->dev), "add") == 0)
 387                         if (compare_devpath(udev_device_get_devpath(loop_event->dev),
 388                                             udev_device_get_physdevpath(event->dev)) != 0) {
 389                                 dbg(event->udev, "%llu, physical device event still pending %llu (%s)\n",
 390                                     udev_device_get_seqnum(event->dev),
 391                                     udev_device_get_seqnum(loop_event->dev),
 392                                     udev_device_get_devpath(loop_event->dev));
 393                                 event->delaying_seqnum = udev_device_get_seqnum(loop_event->dev);
 394                                 return 6;
 395                         }
 396         }
 397         return 0;
 398 }
 399
 400 /* serializes events for the identical and parent and child devices */
 401 static void event_queue_manager(struct udev *udev)
 402 {
 403         struct udev_list_node *loop;
 404         struct udev_list_node *tmp;
 405
 406         if (udev_list_is_empty(&event_list)) {
 407                 if (childs > 0) {
 408                         err(udev, "event list empty, but childs count is %i", childs);
 409                         childs = 0;
 410                 }
 411                 return;
 412         }
 413
 414         udev_list_node_foreach_safe(loop, tmp, &event_list) {
 415                 struct udev_event *loop_event = node_to_event(loop);
 416
 417                 if (childs >= max_childs) {
 418                         info(udev, "maximum number (%i) of childs reached\n", childs);
 419                         break;
 420                 }
 421
 422                 if (loop_event->pid != 0)
 423                         continue;
 424
 425                 /* do not start event if parent or child event is still running */
 426                 if (devpath_busy(loop_event) != 0) {
 427                         dbg(udev, "delay seq %llu (%s)\n",
 428                             udev_device_get_seqnum(loop_event->dev),
 429                             udev_device_get_devpath(loop_event->dev));
 430                         continue;
 431                 }
 432
 433                 event_fork(loop_event);
 434                 dbg(udev, "moved seq %llu to running list\n", udev_device_get_seqnum(loop_event->dev));
 435         }
 436 }
 437
 438 /* receive the udevd message from userspace */
 439 static void handle_ctrl_msg(struct udev_ctrl *uctrl)
 440 {
 441         struct udev *udev = udev_ctrl_get_udev(uctrl);
 442         struct udev_ctrl_msg *ctrl_msg;
 443         const char *str;
 444         int i;
 445
 446         ctrl_msg = udev_ctrl_receive_msg(uctrl);
 447         if (ctrl_msg == NULL)
 448                 return;
 449
 450         i = udev_ctrl_get_set_log_level(ctrl_msg);
 451         if (i >= 0) {
 452                 info(udev, "udevd message (SET_LOG_PRIORITY) received, log_priority=%i\n", i);
 453                 udev_set_log_priority(udev, i);
 454         }
 455
 456         if (udev_ctrl_get_stop_exec_queue(ctrl_msg) > 0) {
 457                 info(udev, "udevd message (STOP_EXEC_QUEUE) received\n");
 458                 stop_exec_q = 1;
 459         }
 460
 461         if (udev_ctrl_get_start_exec_queue(ctrl_msg) > 0) {
 462                 info(udev, "udevd message (START_EXEC_QUEUE) received\n");
 463                 stop_exec_q = 0;
 464                 event_queue_manager(udev);
 465         }
 466
 467         if (udev_ctrl_get_reload_rules(ctrl_msg) > 0) {
 468                 info(udev, "udevd message (RELOAD_RULES) received\n");
 469                 reload_config = 1;
 470         }
 471
 472         str = udev_ctrl_get_set_env(ctrl_msg);
 473         if (str != NULL) {
 474                 char *key;
 475
 476                 key = strdup(str);
 477                 if (key != NULL) {
 478                         char *val;
 479
 480                         val = strchr(key, '=');
 481                         if (val != NULL) {
 482                                 val[0] = '\0';
 483                                 val = &val[1];
 484                                 if (val[0] == '\0') {
 485                                         info(udev, "udevd message (ENV) received, unset '%s'\n", key);
 486                                         udev_add_property(udev, key, NULL);
 487                                 } else {
 488                                         info(udev, "udevd message (ENV) received, set '%s=%s'\n", key, val);
 489                                         udev_add_property(udev, key, val);
 490                                 }
 491                         } else {
 492                                 err(udev, "wrong key format '%s'\n", key);
 493                         }
 494                         free(key);
 495                 }
 496         }
 497
 498         i = udev_ctrl_get_set_max_childs(ctrl_msg);
 499         if (i >= 0) {
 500                 info(udev, "udevd message (SET_MAX_CHILDS) received, max_childs=%i\n", i);
 501                 max_childs = i;
 502         }
 503         udev_ctrl_msg_unref(ctrl_msg);
 504 }
 505
 506 static void asmlinkage sig_handler(int signum)
 507 {
 508         switch (signum) {
 509                 case SIGINT:
 510                 case SIGTERM:
 511                         udev_exit = 1;
 512                         break;
 513                 case SIGCHLD:
 514                         /* set flag, then write to pipe if needed */
 515                         sigchilds_waiting = 1;
 516                         break;
 517                 case SIGHUP:
 518                         reload_config = 1;
 519                         break;
 520         }
 521
 522         signal_received = 1;
 523 }
 524
 525 static void udev_done(int pid, int exitstatus)
 526 {
 527         struct udev_list_node *loop;
 528
 529         /* find event associated with pid and delete it */
 530         udev_list_node_foreach(loop, &event_list) {
 531                 struct udev_event *loop_event = node_to_event(loop);
 532
 533                 if (loop_event->pid == pid) {
 534                         info(loop_event->udev, "seq %llu cleanup, pid [%d], status %i, %ld seconds old\n",
 535                              udev_device_get_seqnum(loop_event->dev), loop_event->pid,
 536                              exitstatus, time(NULL) - loop_event->queue_time);
 537                         loop_event->exitstatus = exitstatus;
 538                         if (debug_trace)
 539                                 fprintf(stderr, "exit %s (%llu)\n",
 540                                        udev_device_get_syspath(loop_event->dev),
 541                                        udev_device_get_seqnum(loop_event->dev));
 542                         event_queue_delete(loop_event);
 543                         childs--;
 544
 545                         /* there may be dependent events waiting */
 546                         run_exec_q = 1;
 547                         return;
 548                 }
 549         }
 550 }
 551
 552 static void reap_sigchilds(void)
 553 {
 554         pid_t pid;
 555         int status;
 556
 557         while (1) {
 558                 pid = waitpid(-1, &status, WNOHANG);
 559                 if (pid <= 0)
 560                         break;
 561                 if (WIFEXITED(status))
 562                         status = WEXITSTATUS(status);
 563                 else if (WIFSIGNALED(status))
 564                         status = WTERMSIG(status) + 128;
 565                 else
 566                         status = 0;
 567                 udev_done(pid, status);
 568         }
 569 }
 570
 571 static void cleanup_queue_dir(struct udev *udev)
 572 {
 573         char dirname[UTIL_PATH_SIZE];
 574         char filename[UTIL_PATH_SIZE];
 575         DIR *dir;
 576
 577         util_strlcpy(filename, udev_get_dev_path(udev), sizeof(filename));
 578         util_strlcat(filename, "/.udev/uevent_seqnum", sizeof(filename));
 579         unlink(filename);
 580
 581         util_strlcpy(dirname, udev_get_dev_path(udev), sizeof(dirname));
 582         util_strlcat(dirname, "/.udev/queue", sizeof(dirname));
 583         dir = opendir(dirname);
 584         if (dir != NULL) {
 585                 while (1) {
 586                         struct dirent *dent;
 587
 588                         dent = readdir(dir);
 589                         if (dent == NULL || dent->d_name[0] == '\0')
 590                                 break;
 591                         if (dent->d_name[0] == '.')
 592                                 continue;
 593                         util_strlcpy(filename, dirname, sizeof(filename));
 594                         util_strlcat(filename, "/", sizeof(filename));
 595                         util_strlcat(filename, dent->d_name, sizeof(filename));
 596                         unlink(filename);
 597                 }
 598                 closedir(dir);
 599                 rmdir(dirname);
 600         }
 601 }
 602
 603 static void export_initial_seqnum(struct udev *udev)
 604 {
 605         char filename[UTIL_PATH_SIZE];
 606         int fd;
 607         char seqnum[32];
 608         ssize_t len = 0;
 609
 610         util_strlcpy(filename, udev_get_sys_path(udev), sizeof(filename));
 611         util_strlcat(filename, "/kernel/uevent_seqnum", sizeof(filename));
 612         fd = open(filename, O_RDONLY);
 613         if (fd >= 0) {
 614                 len = read(fd, seqnum, sizeof(seqnum)-1);
 615                 close(fd);
 616         }
 617         if (len <= 0) {
 618                 strcpy(seqnum, "0\n");
 619                 len = 3;
 620         }
 621         util_strlcpy(filename, udev_get_dev_path(udev), sizeof(filename));
 622         util_strlcat(filename, "/.udev/uevent_seqnum", sizeof(filename));
 623         util_create_path(udev, filename);
 624         fd = open(filename, O_WRONLY|O_TRUNC|O_CREAT, 0644);
 625         if (fd >= 0) {
 626                 write(fd, seqnum, len);
 627                 close(fd);
 628         }
 629 }
 630
 631 int main(int argc, char *argv[])
 632 {
 633         struct udev *udev;
 634         int fd;
 635         struct sigaction act;
 636         const char *value;
 637         int daemonize = 0;
 638         static const struct option options[] = {
 639                 { "daemon", no_argument, NULL, 'd' },
 640                 { "debug-trace", no_argument, NULL, 't' },
 641                 { "debug", no_argument, NULL, 'D' },
 642                 { "help", no_argument, NULL, 'h' },
 643                 { "version", no_argument, NULL, 'V' },
 644                 {}
 645         };
 646         int rc = 1;
 647
 648         udev = udev_new();
 649         if (udev == NULL)
 650                 goto exit;
 651
 652         logging_init("udevd");
 653         udev_set_log_fn(udev, log_fn);
 654         info(udev, "version %s\n", VERSION);
 655         udev_selinux_init(udev);
 656
 657         while (1) {
 658                 int option;
 659
 660                 option = getopt_long(argc, argv, "dDthV", options, NULL);
 661                 if (option == -1)
 662                         break;
 663
 664                 switch (option) {
 665                 case 'd':
 666                         daemonize = 1;
 667                         break;
 668                 case 't':
 669                         debug_trace = 1;
 670                         break;
 671                 case 'D':
 672                         debug = 1;
 673                         if (udev_get_log_priority(udev) < LOG_INFO)
 674                                 udev_set_log_priority(udev, LOG_INFO);
 675                         break;
 676                 case 'h':
 677                         printf("Usage: udevd [--help] [--daemon] [--debug-trace] [--debug] [--version]\n");
 678                         goto exit;
 679                 case 'V':
 680                         printf("%s\n", VERSION);
 681                         goto exit;
 682                 default:
 683                         goto exit;
 684                 }
 685         }
 686
 687         if (getuid() != 0) {
 688                 fprintf(stderr, "root privileges required\n");
 689                 err(udev, "root privileges required\n");
 690                 goto exit;
 691         }
 692
 693         /* make sure std{in,out,err} fd's are in a sane state */
 694         fd = open("/dev/null", O_RDWR);
 695         if (fd < 0) {
 696                 fprintf(stderr, "cannot open /dev/null\n");
 697                 err(udev, "cannot open /dev/null\n");
 698         }
 699         if (write(STDOUT_FILENO, 0, 0) < 0)
 700                 dup2(fd, STDOUT_FILENO);
 701         if (write(STDERR_FILENO, 0, 0) < 0)
 702                 dup2(fd, STDERR_FILENO);
 703
 704         /* init control socket, bind() ensures, that only one udevd instance is running */
 705         udev_ctrl = udev_ctrl_new_from_socket(udev, UDEV_CTRL_SOCK_PATH);
 706         if (udev_ctrl == NULL) {
 707                 fprintf(stderr, "error initializing control socket");
 708                 err(udev, "error initializing udevd socket");
 709                 rc = 1;
 710                 goto exit;
 711         }
 712
 713         if (udev_ctrl_enable_receiving(udev_ctrl) < 0) {
 714                 fprintf(stderr, "error binding control socket, seems udevd is already running\n");
 715                 err(udev, "error binding control socket, seems udevd is already running\n");
 716                 rc = 1;
 717                 goto exit;
 718         }
 719
 720         kernel_monitor = udev_monitor_new_from_netlink(udev);
 721         if (kernel_monitor == NULL || udev_monitor_enable_receiving(kernel_monitor) < 0) {
 722                 fprintf(stderr, "error initializing netlink socket\n");
 723                 err(udev, "error initializing netlink socket\n");
 724                 rc = 3;
 725                 goto exit;
 726         }
 727         udev_monitor_set_receive_buffer_size(kernel_monitor, 128*1024*1024);
 728
 729         rules = udev_rules_new(udev, 1);
 730         if (rules == NULL) {
 731                 err(udev, "error reading rules\n");
 732                 goto exit;
 733         }
 734         udev_list_init(&event_list);
 735         cleanup_queue_dir(udev);
 736         export_initial_seqnum(udev);
 737
 738         if (daemonize) {
 739                 pid_t pid;
 740
 741                 pid = fork();
 742                 switch (pid) {
 743                 case 0:
 744                         dbg(udev, "daemonized fork running\n");
 745                         break;
 746                 case -1:
 747                         err(udev, "fork of daemon failed: %m\n");
 748                         rc = 4;
 749                         goto exit;
 750                 default:
 751                         dbg(udev, "child [%u] running, parent exits\n", pid);
 752                         rc = 0;
 753                         goto exit;
 754                 }
 755         }
 756
 757         /* redirect std{out,err} */
 758         if (!debug && !debug_trace) {
 759                 dup2(fd, STDIN_FILENO);
 760                 dup2(fd, STDOUT_FILENO);
 761                 dup2(fd, STDERR_FILENO);
 762         }
 763         if (fd > STDERR_FILENO)
 764                 close(fd);
 765
 766         /* set scheduling priority for the daemon */
 767         setpriority(PRIO_PROCESS, 0, UDEVD_PRIORITY);
 768
 769         chdir("/");
 770         umask(022);
 771         setsid();
 772
 773         /* OOM_DISABLE == -17 */
 774         fd = open("/proc/self/oom_adj", O_RDWR);
 775         if (fd < 0)
 776                 err(udev, "error disabling OOM: %m\n");
 777         else {
 778                 write(fd, "-17", 3);
 779                 close(fd);
 780         }
 781
 782         fd = open("/dev/kmsg", O_WRONLY);
 783         if (fd > 0) {
 784                 const char *ver_str = "<6>udev: starting version " VERSION "\n";
 785                 char path[UTIL_PATH_SIZE];
 786                 struct stat statbuf;
 787
 788                 write(fd, ver_str, strlen(ver_str));
 789                 util_strlcpy(path, udev_get_sys_path(udev), sizeof(path));
 790                 util_strlcat(path, "/class/mem/null", sizeof(path));
 791                 if (lstat(path, &statbuf) == 0) {
 792                         if (S_ISDIR(statbuf.st_mode)) {
 793                                 const char *depr_str =
 794                                         "<6>udev: deprecated sysfs layout; update the kernel or "
 795                                         "disable CONFIG_SYSFS_DEPRECATED; some udev features will "
 796                                         "not work correctly\n";
 797
 798                                 write(fd, depr_str, strlen(depr_str));
 799                         }
 800                 }
 801                 close(fd);
 802         }
 803
 804         /* set signal handlers */
 805         memset(&act, 0x00, sizeof(struct sigaction));
 806         act.sa_handler = (void (*)(int)) sig_handler;
 807         sigemptyset(&act.sa_mask);
 808         sigaction(SIGINT, &act, NULL);
 809         sigaction(SIGTERM, &act, NULL);
 810         sigaction(SIGCHLD, &act, NULL);
 811         sigaction(SIGHUP, &act, NULL);
 812
 813         /* watch rules directory */
 814         inotify_fd = inotify_init();
 815         if (inotify_fd >= 0) {
 816                 if (udev_get_rules_path(udev) != NULL) {
 817                         inotify_add_watch(inotify_fd, udev_get_rules_path(udev),
 818                                           IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
 819                 } else {
 820                         char filename[UTIL_PATH_SIZE];
 821
 822                         inotify_add_watch(inotify_fd, UDEV_PREFIX "/lib/udev/rules.d",
 823                                           IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
 824                         inotify_add_watch(inotify_fd, SYSCONFDIR "/udev/rules.d",
 825                                           IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
 826
 827                         /* watch dynamic rules directory */
 828                         util_strlcpy(filename, udev_get_dev_path(udev), sizeof(filename));
 829                         util_strlcat(filename, "/.udev/rules.d", sizeof(filename));
 830                         inotify_add_watch(inotify_fd, filename,
 831                                           IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
 832                 }
 833         } else if (errno == ENOSYS)
 834                 info(udev, "unable to use inotify, udevd will not monitor rule files changes\n");
 835         else
 836                 err(udev, "inotify_init failed: %m\n");
 837
 838         /* in trace mode run one event after the other */
 839         if (debug_trace) {
 840                 max_childs = 1;
 841         } else {
 842                 int memsize = mem_size_mb();
 843                 if (memsize > 0)
 844                         max_childs = 128 + (memsize / 4);
 845                 else
 846                         max_childs = UDEVD_MAX_CHILDS;
 847         }
 848         /* possibly overwrite maximum limit of executed events */
 849         value = getenv("UDEVD_MAX_CHILDS");
 850         if (value)
 851                 max_childs = strtoul(value, NULL, 10);
 852         info(udev, "initialize max_childs to %u\n", max_childs);
 853
 854         while (!udev_exit) {
 855                 sigset_t blocked_mask, orig_mask;
 856                 struct pollfd pfd[4];
 857                 struct pollfd *ctrl_poll, *monitor_poll, *inotify_poll = NULL;
 858                 int nfds = 0;
 859                 int fdcount;
 860
 861                 sigfillset(&blocked_mask);
 862                 sigprocmask(SIG_SETMASK, &blocked_mask, &orig_mask);
 863                 if (signal_received) {
 864                         sigprocmask(SIG_SETMASK, &orig_mask, NULL);
 865                         goto handle_signals;
 866                 }
 867
 868                 ctrl_poll = &pfd[nfds++];
 869                 ctrl_poll->fd = udev_ctrl_get_fd(udev_ctrl);
 870                 ctrl_poll->events = POLLIN;
 871
 872                 monitor_poll = &pfd[nfds++];
 873                 monitor_poll->fd = udev_monitor_get_fd(kernel_monitor);
 874                 monitor_poll->events = POLLIN;
 875
 876                 if (inotify_fd >= 0) {
 877                         inotify_poll = &pfd[nfds++];
 878                         inotify_poll->fd = inotify_fd;
 879                         inotify_poll->events = POLLIN;
 880                 }
 881
 882                 fdcount = ppoll(pfd, nfds, NULL, &orig_mask);
 883                 sigprocmask(SIG_SETMASK, &orig_mask, NULL);
 884                 if (fdcount < 0) {
 885                         if (errno == EINTR)
 886                                 goto handle_signals;
 887                         err(udev, "error in select: %m\n");
 888                         continue;
 889                 }
 890
 891                 /* get control message */
 892                 if (ctrl_poll->revents & POLLIN)
 893                         handle_ctrl_msg(udev_ctrl);
 894
 895                 /* get kernel uevent */
 896                 if (monitor_poll->revents & POLLIN) {
 897                         struct udev_device *dev;
 898
 899                         dev = udev_monitor_receive_device(kernel_monitor);
 900                         if (dev != NULL) {
 901                                 struct udev_event *event;
 902
 903                                 event = udev_event_new(dev);
 904                                 if (event != NULL)
 905                                         event_queue_insert(event);
 906                                 else
 907                                         udev_device_unref(dev);
 908                         }
 909                 }
 910
 911                 /* rules directory inotify watch */
 912                 if (inotify_poll && (inotify_poll->revents & POLLIN)) {
 913                         int nbytes;
 914
 915                         /* discard all possible events, we can just reload the config */
 916                         if ((ioctl(inotify_fd, FIONREAD, &nbytes) == 0) && nbytes > 0) {
 917                                 char *buf;
 918
 919                                 reload_config = 1;
 920                                 buf = malloc(nbytes);
 921                                 if (buf == NULL) {
 922                                         err(udev, "error getting buffer for inotify, disable watching\n");
 923                                         close(inotify_fd);
 924                                         inotify_fd = -1;
 925                                 }
 926                                 read(inotify_fd, buf, nbytes);
 927                                 free(buf);
 928                         }
 929                 }
 930
 931 handle_signals:
 932                 signal_received = 0;
 933
 934                 /* rules changed, set by inotify or a HUP signal */
 935                 if (reload_config) {
 936                         struct udev_rules *rules_new;
 937
 938                         reload_config = 0;
 939                         rules_new = udev_rules_new(udev, 1);
 940                         if (rules_new != NULL) {
 941                                 udev_rules_unref(rules);
 942                                 rules = rules_new;
 943                         }
 944                 }
 945
 946                 if (sigchilds_waiting) {
 947                         sigchilds_waiting = 0;
 948                         reap_sigchilds();
 949                 }
 950
 951                 if (run_exec_q) {
 952                         run_exec_q = 0;
 953                         if (!stop_exec_q)
 954                                 event_queue_manager(udev);
 955                 }
 956         }
 957         cleanup_queue_dir(udev);
 958         rc = 0;
 959 exit:
 960         udev_rules_unref(rules);
 961         udev_ctrl_unref(udev_ctrl);
 962         if (inotify_fd >= 0)
 963                 close(inotify_fd);
 964         udev_monitor_unref(kernel_monitor);
 965         udev_selinux_exit(udev);
 966         udev_unref(udev);
 967         logging_close();
 968         return rc;
 969 }