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