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 <sys/select.h>
  31 #include <sys/wait.h>
  32 #include <sys/stat.h>
  33 #include <sys/ioctl.h>
  34 #ifdef HAVE_INOTIFY
  35 #include <sys/inotify.h>
  36 #endif
  37
  38 #include "udev.h"
  39
  40 #define UDEVD_PRIORITY                  -4
  41 #define UDEV_PRIORITY                   -2
  42
  43 /* maximum limit of forked childs */
  44 #define UDEVD_MAX_CHILDS                256
  45
  46 static int debug;
  47
  48 static void log_fn(struct udev *udev, int priority,
  49                    const char *file, int line, const char *fn,
  50                    const char *format, va_list args)
  51 {
  52         if (debug) {
  53                 fprintf(stderr, "[%d] %s: ", (int) getpid(), fn);
  54                 vfprintf(stderr, format, args);
  55         } else {
  56                 vsyslog(priority, format, args);
  57         }
  58 }
  59
  60 static int debug_trace;
  61 static struct udev_rules *rules;
  62 static struct udev_ctrl *udev_ctrl;
  63 static struct udev_monitor *kernel_monitor;
  64 static int inotify_fd = -1;
  65
  66 static int signal_pipe[2] = {-1, -1};
  67 static volatile int sigchilds_waiting;
  68 static volatile int udev_exit;
  69 static volatile int reload_config;
  70 static int run_exec_q;
  71 static int stop_exec_q;
  72 static int max_childs;
  73
  74 static struct udev_list_node exec_list;
  75 static struct udev_list_node running_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(&exec_list) && udev_list_is_empty(&running_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(&exec_list) && udev_list_is_empty(&running_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         pid = fork();
 184         switch (pid) {
 185         case 0:
 186                 /* child */
 187                 udev_monitor_unref(kernel_monitor);
 188                 udev_ctrl_unref(udev_ctrl);
 189                 if (inotify_fd >= 0)
 190                         close(inotify_fd);
 191                 close(signal_pipe[READ_END]);
 192                 close(signal_pipe[WRITE_END]);
 193                 logging_close();
 194                 logging_init("udevd-event");
 195                 setpriority(PRIO_PROCESS, 0, UDEV_PRIORITY);
 196
 197                 /* set signal handlers */
 198                 memset(&act, 0x00, sizeof(act));
 199                 act.sa_handler = (void (*)(int)) event_sig_handler;
 200                 sigemptyset (&act.sa_mask);
 201                 act.sa_flags = 0;
 202                 sigaction(SIGALRM, &act, NULL);
 203
 204                 /* reset to default */
 205                 act.sa_handler = SIG_DFL;
 206                 sigaction(SIGINT, &act, NULL);
 207                 sigaction(SIGTERM, &act, NULL);
 208                 sigaction(SIGCHLD, &act, NULL);
 209                 sigaction(SIGHUP, &act, NULL);
 210
 211                 /* set timeout to prevent hanging processes */
 212                 alarm(UDEV_EVENT_TIMEOUT);
 213
 214                 /* apply rules, create node, symlinks */
 215                 err = udev_event_execute_rules(event, rules);
 216
 217                 /* rules may change/disable the timeout */
 218                 if (udev_device_get_event_timeout(event->dev) >= 0)
 219                         alarm(udev_device_get_event_timeout(event->dev));
 220
 221                 /* execute RUN= */
 222                 if (err == 0 && !event->ignore_device && udev_get_run(event->udev))
 223                         udev_event_execute_run(event);
 224                 info(event->udev, "seq %llu exit with %i\n", udev_device_get_seqnum(event->dev), err);
 225                 logging_close();
 226                 if (err != 0)
 227                         exit(1);
 228                 exit(0);
 229         case -1:
 230                 err(event->udev, "fork of child failed: %m\n");
 231                 event_queue_delete(event);
 232                 break;
 233         default:
 234                 /* get SIGCHLD in main loop */
 235                 info(event->udev, "seq %llu forked, pid [%d], '%s' '%s', %ld seconds old\n",
 236                      udev_device_get_seqnum(event->dev),
 237                      pid,
 238                      udev_device_get_action(event->dev),
 239                      udev_device_get_subsystem(event->dev),
 240                      time(NULL) - event->queue_time);
 241                 event->pid = pid;
 242         }
 243 }
 244
 245 static void event_queue_insert(struct udev_event *event)
 246 {
 247         char filename[UTIL_PATH_SIZE];
 248         int fd;
 249
 250         event->queue_time = time(NULL);
 251
 252         export_event_state(event, EVENT_QUEUED);
 253         info(event->udev, "seq %llu queued, '%s' '%s'\n", udev_device_get_seqnum(event->dev),
 254              udev_device_get_action(event->dev), udev_device_get_subsystem(event->dev));
 255
 256         util_strlcpy(filename, udev_get_dev_path(event->udev), sizeof(filename));
 257         util_strlcat(filename, "/.udev/uevent_seqnum", sizeof(filename));
 258         fd = open(filename, O_WRONLY|O_TRUNC|O_CREAT, 0644);
 259         if (fd >= 0) {
 260                 char str[32];
 261                 int len;
 262
 263                 len = sprintf(str, "%llu\n", udev_device_get_seqnum(event->dev));
 264                 write(fd, str, len);
 265                 close(fd);
 266         }
 267
 268         /* run one event after the other in debug mode */
 269         if (debug_trace) {
 270                 udev_list_node_append(&event->node, &running_list);
 271                 event_fork(event);
 272                 waitpid(event->pid, NULL, 0);
 273                 event_queue_delete(event);
 274                 return;
 275         }
 276
 277         /* run all events with a timeout set immediately */
 278         if (udev_device_get_timeout(event->dev) > 0) {
 279                 udev_list_node_append(&event->node, &running_list);
 280                 event_fork(event);
 281                 return;
 282         }
 283
 284         udev_list_node_append(&event->node, &exec_list);
 285         run_exec_q = 1;
 286 }
 287
 288 static int mem_size_mb(void)
 289 {
 290         FILE* f;
 291         char buf[4096];
 292         long int memsize = -1;
 293
 294         f = fopen("/proc/meminfo", "r");
 295         if (f == NULL)
 296                 return -1;
 297
 298         while (fgets(buf, sizeof(buf), f) != NULL) {
 299                 long int value;
 300
 301                 if (sscanf(buf, "MemTotal: %ld kB", &value) == 1) {
 302                         memsize = value / 1024;
 303                         break;
 304                 }
 305         }
 306
 307         fclose(f);
 308         return memsize;
 309 }
 310
 311 static int compare_devpath(const char *running, const char *waiting)
 312 {
 313         int i;
 314
 315         for (i = 0; i < UTIL_PATH_SIZE; i++) {
 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                 if (running[i] != waiting[i])
 330                         break;
 331         }
 332
 333         return 0;
 334 }
 335
 336 /* lookup event for identical, parent, child, or physical device */
 337 static int devpath_busy(struct udev_event *event, int limit)
 338 {
 339         struct udev_list_node *loop;
 340         int childs_count = 0;
 341
 342         /* check exec-queue which may still contain delayed events we depend on */
 343         udev_list_node_foreach(loop, &exec_list) {
 344                 struct udev_event *loop_event = node_to_event(loop);
 345
 346                 /* skip ourself and all later events */
 347                 if (udev_device_get_seqnum(loop_event->dev) >= udev_device_get_seqnum(event->dev))
 348                         break;
 349
 350                 /* check our old name */
 351                 if (udev_device_get_devpath_old(event->dev) != NULL)
 352                         if (strcmp(udev_device_get_devpath(loop_event->dev), udev_device_get_devpath_old(event->dev)) == 0)
 353                                 return 2;
 354
 355                 /* check identical, parent, or child device event */
 356                 if (compare_devpath(udev_device_get_devpath(loop_event->dev), udev_device_get_devpath(event->dev)) != 0) {
 357                         dbg(event->udev, "%llu, device event still pending %llu (%s)\n",
 358                             udev_device_get_seqnum(event->dev),
 359                             udev_device_get_seqnum(loop_event->dev),
 360                             udev_device_get_devpath(loop_event->dev));
 361                         return 3;
 362                 }
 363
 364                 /* check for our major:minor number */
 365                 if (major(udev_device_get_devnum(event->dev)) > 0 &&
 366                     udev_device_get_devnum(loop_event->dev) == udev_device_get_devnum(event->dev) &&
 367                     strcmp(udev_device_get_subsystem(event->dev), udev_device_get_subsystem(loop_event->dev)) == 0) {
 368                         dbg(event->udev, "%llu, device event still pending %llu (%d:%d)\n",
 369                             udev_device_get_seqnum(event->dev),
 370                             udev_device_get_seqnum(loop_event->dev),
 371                             major(udev_device_get_devnum(loop_event->dev)), minor(udev_device_get_devnum(loop_event->dev)));
 372                         return 4;
 373                 }
 374
 375                 /* check physical device event (special case of parent) */
 376                 if (udev_device_get_physdevpath(event->dev) != NULL &&
 377                     strcmp(udev_device_get_action(event->dev), "add") == 0)
 378                         if (compare_devpath(udev_device_get_devpath(loop_event->dev),
 379                                             udev_device_get_physdevpath(event->dev)) != 0) {
 380                                 dbg(event->udev, "%llu, physical device event still pending %llu (%s)\n",
 381                                     udev_device_get_seqnum(event->dev),
 382                                     udev_device_get_seqnum(loop_event->dev),
 383                                     udev_device_get_devpath(loop_event->dev));
 384                                 return 5;
 385                         }
 386         }
 387
 388         /* check run queue for still running events */
 389         udev_list_node_foreach(loop, &running_list) {
 390                 struct udev_event *loop_event = node_to_event(loop);
 391
 392                 if (childs_count++ >= limit) {
 393                         info(event->udev, "%llu, maximum number (%i) of childs reached\n",
 394                              udev_device_get_seqnum(event->dev), childs_count);
 395                         return 1;
 396                 }
 397
 398                 /* check our old name */
 399                 if (udev_device_get_devpath_old(event->dev) != NULL)
 400                         if (strcmp(udev_device_get_devpath(loop_event->dev), udev_device_get_devpath_old(event->dev)) == 0)
 401                                 return 2;
 402
 403                 /* check identical, parent, or child device event */
 404                 if (compare_devpath(udev_device_get_devpath(loop_event->dev), udev_device_get_devpath(event->dev)) != 0) {
 405                         dbg(event->udev, "%llu, device event still running %llu (%s)\n",
 406                             udev_device_get_seqnum(event->dev),
 407                             udev_device_get_seqnum(loop_event->dev),
 408                             udev_device_get_devpath(loop_event->dev));
 409                         return 3;
 410                 }
 411
 412                 /* check for our major:minor number */
 413                 if (major(udev_device_get_devnum(event->dev)) > 0 &&
 414                     udev_device_get_devnum(loop_event->dev) == udev_device_get_devnum(event->dev) &&
 415                     strcmp(udev_device_get_subsystem(event->dev), udev_device_get_subsystem(loop_event->dev)) == 0) {
 416                         dbg(event->udev, "%llu, device event still pending %llu (%d:%d)\n",
 417                             udev_device_get_seqnum(event->dev),
 418                             udev_device_get_seqnum(loop_event->dev),
 419                             major(udev_device_get_devnum(loop_event->dev)), minor(udev_device_get_devnum(loop_event->dev)));
 420                         return 4;
 421                 }
 422
 423                 /* check physical device event (special case of parent) */
 424                 if (udev_device_get_physdevpath(event->dev) != NULL &&
 425                     strcmp(udev_device_get_action(event->dev), "add") == 0)
 426                         if (compare_devpath(udev_device_get_devpath(loop_event->dev),
 427                                             udev_device_get_physdevpath(event->dev)) != 0) {
 428                                 dbg(event->udev, "%llu, physical device event still pending %llu (%s)\n",
 429                                     udev_device_get_seqnum(event->dev),
 430                                     udev_device_get_seqnum(loop_event->dev),
 431                                     udev_device_get_devpath(loop_event->dev));
 432                                 return 5;
 433                         }
 434         }
 435         return 0;
 436 }
 437
 438 /* serializes events for the identical and parent and child devices */
 439 static void event_queue_manager(struct udev *udev)
 440 {
 441         struct udev_list_node *loop;
 442         struct udev_list_node *tmp;
 443
 444         if (udev_list_is_empty(&exec_list))
 445                 return;
 446
 447         udev_list_node_foreach_safe(loop, tmp, &exec_list) {
 448                 struct udev_event *loop_event = node_to_event(loop);
 449
 450                 /* serialize and wait for parent or child events */
 451                 if (devpath_busy(loop_event, max_childs) != 0) {
 452                         dbg(udev, "delay seq %llu (%s)\n",
 453                             udev_device_get_seqnum(loop_event->dev),
 454                             udev_device_get_devpath(loop_event->dev));
 455                         continue;
 456                 }
 457
 458                 /* move event to run list */
 459                 udev_list_node_remove(&loop_event->node);
 460                 udev_list_node_append(&loop_event->node, &running_list);
 461                 event_fork(loop_event);
 462                 dbg(udev, "moved seq %llu to running list\n", udev_device_get_seqnum(loop_event->dev));
 463         }
 464 }
 465
 466 /* receive the udevd message from userspace */
 467 static void handle_ctrl_msg(struct udev_ctrl *uctrl)
 468 {
 469         struct udev *udev = udev_ctrl_get_udev(uctrl);
 470         struct udev_ctrl_msg *ctrl_msg;
 471         const char *str;
 472         int i;
 473
 474         ctrl_msg = udev_ctrl_receive_msg(uctrl);
 475         if (ctrl_msg == NULL)
 476                 return;
 477
 478         i = udev_ctrl_get_set_log_level(ctrl_msg);
 479         if (i >= 0) {
 480                 info(udev, "udevd message (SET_LOG_PRIORITY) received, log_priority=%i\n", i);
 481                 udev_set_log_priority(udev, i);
 482         }
 483
 484         if (udev_ctrl_get_stop_exec_queue(ctrl_msg) > 0) {
 485                 info(udev, "udevd message (STOP_EXEC_QUEUE) received\n");
 486                 stop_exec_q = 1;
 487         }
 488
 489         if (udev_ctrl_get_start_exec_queue(ctrl_msg) > 0) {
 490                 info(udev, "udevd message (START_EXEC_QUEUE) received\n");
 491                 stop_exec_q = 0;
 492                 event_queue_manager(udev);
 493         }
 494
 495         if (udev_ctrl_get_reload_rules(ctrl_msg) > 0) {
 496                 info(udev, "udevd message (RELOAD_RULES) received\n");
 497                 reload_config = 1;
 498         }
 499
 500         str = udev_ctrl_get_set_env(ctrl_msg);
 501         if (str != NULL) {
 502                 char *key;
 503
 504                 key = strdup(str);
 505                 if (key != NULL) {
 506                         char *val;
 507
 508                         val = strchr(key, '=');
 509                         if (val != NULL) {
 510                                 val[0] = '\0';
 511                                 val = &val[1];
 512                                 if (val[0] == '\0') {
 513                                         info(udev, "udevd message (ENV) received, unset '%s'\n", key);
 514                                         udev_add_property(udev, key, NULL);
 515                                 } else {
 516                                         info(udev, "udevd message (ENV) received, set '%s=%s'\n", key, val);
 517                                         udev_add_property(udev, key, val);
 518                                 }
 519                         } else {
 520                                 err(udev, "wrong key format '%s'\n", key);
 521                         }
 522                         free(key);
 523                 }
 524         }
 525
 526         i = udev_ctrl_get_set_max_childs(ctrl_msg);
 527         if (i >= 0) {
 528                 info(udev, "udevd message (SET_MAX_CHILDS) received, max_childs=%i\n", i);
 529                 max_childs = i;
 530         }
 531
 532         udev_ctrl_msg_unref(ctrl_msg);
 533 }
 534
 535 static void asmlinkage sig_handler(int signum)
 536 {
 537         switch (signum) {
 538                 case SIGINT:
 539                 case SIGTERM:
 540                         udev_exit = 1;
 541                         break;
 542                 case SIGCHLD:
 543                         /* set flag, then write to pipe if needed */
 544                         sigchilds_waiting = 1;
 545                         break;
 546                 case SIGHUP:
 547                         reload_config = 1;
 548                         break;
 549         }
 550
 551         /* write to pipe, which will wakeup select() in our mainloop */
 552         write(signal_pipe[WRITE_END], "", 1);
 553 }
 554
 555 static void udev_done(int pid, int exitstatus)
 556 {
 557         struct udev_list_node *loop;
 558
 559         /* find event associated with pid and delete it */
 560         udev_list_node_foreach(loop, &running_list) {
 561                 struct udev_event *loop_event = node_to_event(loop);
 562
 563                 if (loop_event->pid == pid) {
 564                         info(loop_event->udev, "seq %llu cleanup, pid [%d], status %i, %ld seconds old\n",
 565                              udev_device_get_seqnum(loop_event->dev), loop_event->pid,
 566                              exitstatus, time(NULL) - loop_event->queue_time);
 567                         loop_event->exitstatus = exitstatus;
 568                         event_queue_delete(loop_event);
 569
 570                         /* there may be events waiting with the same devpath */
 571                         run_exec_q = 1;
 572                         return;
 573                 }
 574         }
 575 }
 576
 577 static void reap_sigchilds(void)
 578 {
 579         pid_t pid;
 580         int status;
 581
 582         while (1) {
 583                 pid = waitpid(-1, &status, WNOHANG);
 584                 if (pid <= 0)
 585                         break;
 586                 if (WIFEXITED(status))
 587                         status = WEXITSTATUS(status);
 588                 else if (WIFSIGNALED(status))
 589                         status = WTERMSIG(status) + 128;
 590                 else
 591                         status = 0;
 592                 udev_done(pid, status);
 593         }
 594 }
 595
 596 static void export_initial_seqnum(struct udev *udev)
 597 {
 598         char filename[UTIL_PATH_SIZE];
 599         int fd;
 600         char seqnum[32];
 601         ssize_t len = 0;
 602
 603         util_strlcpy(filename, udev_get_sys_path(udev), sizeof(filename));
 604         util_strlcat(filename, "/kernel/uevent_seqnum", sizeof(filename));
 605         fd = open(filename, O_RDONLY);
 606         if (fd >= 0) {
 607                 len = read(fd, seqnum, sizeof(seqnum)-1);
 608                 close(fd);
 609         }
 610         if (len <= 0) {
 611                 strcpy(seqnum, "0\n");
 612                 len = 3;
 613         }
 614         util_strlcpy(filename, udev_get_dev_path(udev), sizeof(filename));
 615         util_strlcat(filename, "/.udev/uevent_seqnum", sizeof(filename));
 616         util_create_path(udev, filename);
 617         fd = open(filename, O_WRONLY|O_TRUNC|O_CREAT, 0644);
 618         if (fd >= 0) {
 619                 write(fd, seqnum, len);
 620                 close(fd);
 621         }
 622 }
 623
 624 int main(int argc, char *argv[])
 625 {
 626         struct udev *udev;
 627         int err;
 628         int fd;
 629         struct sigaction act;
 630         fd_set readfds;
 631         const char *value;
 632         int daemonize = 0;
 633         static const struct option options[] = {
 634                 { "daemon", no_argument, NULL, 'd' },
 635                 { "debug-trace", no_argument, NULL, 't' },
 636                 { "debug", no_argument, NULL, 'D' },
 637                 { "help", no_argument, NULL, 'h' },
 638                 { "version", no_argument, NULL, 'V' },
 639                 {}
 640         };
 641         int rc = 1;
 642         int maxfd;
 643
 644         udev = udev_new();
 645         if (udev == NULL)
 646                 goto exit;
 647
 648         logging_init("udevd");
 649         udev_set_log_fn(udev, log_fn);
 650         info(udev, "version %s\n", VERSION);
 651         udev_selinux_init(udev);
 652
 653         while (1) {
 654                 int option;
 655
 656                 option = getopt_long(argc, argv, "dDthV", options, NULL);
 657                 if (option == -1)
 658                         break;
 659
 660                 switch (option) {
 661                 case 'd':
 662                         daemonize = 1;
 663                         break;
 664                 case 't':
 665                         debug_trace = 1;
 666                         break;
 667                 case 'D':
 668                         debug = 1;
 669                         if (udev_get_log_priority(udev) < LOG_INFO)
 670                                 udev_set_log_priority(udev, LOG_INFO);
 671                         break;
 672                 case 'h':
 673                         printf("Usage: udevd [--help] [--daemon] [--debug-trace] [--debug] [--version]\n");
 674                         goto exit;
 675                 case 'V':
 676                         printf("%s\n", VERSION);
 677                         goto exit;
 678                 default:
 679                         goto exit;
 680                 }
 681         }
 682
 683         if (getuid() != 0) {
 684                 fprintf(stderr, "root privileges required\n");
 685                 err(udev, "root privileges required\n");
 686                 goto exit;
 687         }
 688
 689         /* make sure std{in,out,err} fd's are in a sane state */
 690         fd = open("/dev/null", O_RDWR);
 691         if (fd < 0) {
 692                 fprintf(stderr, "cannot open /dev/null\n");
 693                 err(udev, "cannot open /dev/null\n");
 694         }
 695         if (fd > STDIN_FILENO)
 696                 dup2(fd, STDIN_FILENO);
 697         if (write(STDOUT_FILENO, 0, 0) < 0)
 698                 dup2(fd, STDOUT_FILENO);
 699         if (write(STDERR_FILENO, 0, 0) < 0)
 700                 dup2(fd, STDERR_FILENO);
 701
 702         /* init control socket, bind() ensures, that only one udevd instance is running */
 703         udev_ctrl = udev_ctrl_new_from_socket(udev, UDEV_CTRL_SOCK_PATH);
 704         if (udev_ctrl == NULL) {
 705                 fprintf(stderr, "error initializing control socket");
 706                 err(udev, "error initializing udevd socket");
 707                 rc = 1;
 708                 goto exit;
 709         }
 710
 711         if (udev_ctrl_enable_receiving(udev_ctrl) < 0) {
 712                 fprintf(stderr, "error binding control socket, seems udevd is already running\n");
 713                 err(udev, "error binding control socket, seems udevd is already running\n");
 714                 rc = 1;
 715                 goto exit;
 716         }
 717
 718         kernel_monitor = udev_monitor_new_from_netlink(udev);
 719         if (kernel_monitor == NULL || udev_monitor_enable_receiving(kernel_monitor) < 0) {
 720                 fprintf(stderr, "error initializing netlink socket\n");
 721                 err(udev, "error initializing netlink socket\n");
 722                 rc = 3;
 723                 goto exit;
 724         }
 725         udev_monitor_set_receive_buffer_size(kernel_monitor, 128*1024*1024);
 726
 727         err = pipe(signal_pipe);
 728         if (err < 0) {
 729                 err(udev, "error getting pipes: %m\n");
 730                 goto exit;
 731         }
 732
 733         err = fcntl(signal_pipe[READ_END], F_GETFL, 0);
 734         if (err < 0) {
 735                 err(udev, "error fcntl on read pipe: %m\n");
 736                 goto exit;
 737         }
 738         err = fcntl(signal_pipe[READ_END], F_SETFL, err | O_NONBLOCK);
 739         if (err < 0) {
 740                 err(udev, "error fcntl on read pipe: %m\n");
 741                 goto exit;
 742         }
 743
 744         err = fcntl(signal_pipe[WRITE_END], F_GETFL, 0);
 745         if (err < 0) {
 746                 err(udev, "error fcntl on write pipe: %m\n");
 747                 goto exit;
 748         }
 749         err = fcntl(signal_pipe[WRITE_END], F_SETFL, err | O_NONBLOCK);
 750         if (err < 0) {
 751                 err(udev, "error fcntl on write pipe: %m\n");
 752                 goto exit;
 753         }
 754
 755         rules = udev_rules_new(udev, 1);
 756         if (rules == NULL) {
 757                 err(udev, "error reading rules\n");
 758                 goto exit;
 759         }
 760         udev_list_init(&running_list);
 761         udev_list_init(&exec_list);
 762         export_initial_seqnum(udev);
 763
 764         if (daemonize) {
 765                 pid_t pid;
 766
 767                 pid = fork();
 768                 switch (pid) {
 769                 case 0:
 770                         dbg(udev, "daemonized fork running\n");
 771                         break;
 772                 case -1:
 773                         err(udev, "fork of daemon failed: %m\n");
 774                         rc = 4;
 775                         goto exit;
 776                 default:
 777                         dbg(udev, "child [%u] running, parent exits\n", pid);
 778                         rc = 0;
 779                         goto exit;
 780                 }
 781         }
 782
 783         /* redirect std{out,err} */
 784         if (!debug) {
 785                 dup2(fd, STDOUT_FILENO);
 786                 dup2(fd, STDERR_FILENO);
 787         }
 788         if (fd > STDERR_FILENO)
 789                 close(fd);
 790
 791         /* set scheduling priority for the daemon */
 792         setpriority(PRIO_PROCESS, 0, UDEVD_PRIORITY);
 793
 794         chdir("/");
 795         umask(022);
 796         setsid();
 797
 798         /* OOM_DISABLE == -17 */
 799         fd = open("/proc/self/oom_adj", O_RDWR);
 800         if (fd < 0)
 801                 err(udev, "error disabling OOM: %m\n");
 802         else {
 803                 write(fd, "-17", 3);
 804                 close(fd);
 805         }
 806
 807         fd = open("/dev/kmsg", O_WRONLY);
 808         if (fd > 0) {
 809                 const char *ver_str = "<6>udev: starting version " VERSION "\n";
 810                 char path[UTIL_PATH_SIZE];
 811                 struct stat statbuf;
 812
 813                 write(fd, ver_str, strlen(ver_str));
 814                 util_strlcpy(path, udev_get_sys_path(udev), sizeof(path));
 815                 util_strlcat(path, "/class/mem/null", sizeof(path));
 816                 if (lstat(path, &statbuf) == 0) {
 817                         if (S_ISDIR(statbuf.st_mode)) {
 818                                 const char *depr_str = "<6>udev: deprecated sysfs layout (kernel too old, "
 819                                                         "or CONFIG_SYSFS_DEPRECATED) is unsupported, some "
 820                                                         "udev features may fail\n";
 821
 822                                 write(fd, depr_str, strlen(depr_str));
 823                         }
 824                 }
 825                 close(fd);
 826         }
 827
 828         /* set signal handlers */
 829         memset(&act, 0x00, sizeof(struct sigaction));
 830         act.sa_handler = (void (*)(int)) sig_handler;
 831         sigemptyset(&act.sa_mask);
 832         act.sa_flags = SA_RESTART;
 833         sigaction(SIGINT, &act, NULL);
 834         sigaction(SIGTERM, &act, NULL);
 835         sigaction(SIGCHLD, &act, NULL);
 836         sigaction(SIGHUP, &act, NULL);
 837
 838         /* watch rules directory */
 839         inotify_fd = inotify_init();
 840         if (inotify_fd >= 0) {
 841                 if (udev_get_rules_path(udev) != NULL) {
 842                         inotify_add_watch(inotify_fd, udev_get_rules_path(udev),
 843                                           IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
 844                 } else {
 845                         char filename[PATH_MAX];
 846
 847                         inotify_add_watch(inotify_fd, UDEV_PREFIX "/lib/udev/rules.d",
 848                                           IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
 849                         inotify_add_watch(inotify_fd, SYSCONFDIR "/udev/rules.d",
 850                                           IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
 851
 852                         /* watch dynamic rules directory */
 853                         util_strlcpy(filename, udev_get_dev_path(udev), sizeof(filename));
 854                         util_strlcat(filename, "/.udev/rules.d", sizeof(filename));
 855                         inotify_add_watch(inotify_fd, filename,
 856                                           IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
 857                 }
 858         } else if (errno == ENOSYS)
 859                 err(udev, "the kernel does not support inotify, udevd can't monitor rules file changes\n");
 860         else
 861                 err(udev, "inotify_init failed: %m\n");
 862
 863         /* maximum limit of forked childs */
 864         value = getenv("UDEVD_MAX_CHILDS");
 865         if (value)
 866                 max_childs = strtoul(value, NULL, 10);
 867         else {
 868                 int memsize = mem_size_mb();
 869                 if (memsize > 0)
 870                         max_childs = 128 + (memsize / 4);
 871                 else
 872                         max_childs = UDEVD_MAX_CHILDS;
 873         }
 874         info(udev, "initialize max_childs to %u\n", max_childs);
 875
 876         maxfd = udev_ctrl_get_fd(udev_ctrl);
 877         maxfd = UDEV_MAX(maxfd, udev_monitor_get_fd(kernel_monitor));
 878         maxfd = UDEV_MAX(maxfd, signal_pipe[READ_END]);
 879         maxfd = UDEV_MAX(maxfd, inotify_fd);
 880         while (!udev_exit) {
 881                 int fdcount;
 882
 883                 FD_ZERO(&readfds);
 884                 FD_SET(signal_pipe[READ_END], &readfds);
 885                 FD_SET(udev_ctrl_get_fd(udev_ctrl), &readfds);
 886                 FD_SET(udev_monitor_get_fd(kernel_monitor), &readfds);
 887                 if (inotify_fd >= 0)
 888                         FD_SET(inotify_fd, &readfds);
 889                 fdcount = select(maxfd+1, &readfds, NULL, NULL, NULL);
 890                 if (fdcount < 0) {
 891                         if (errno != EINTR)
 892                                 err(udev, "error in select: %m\n");
 893                         continue;
 894                 }
 895
 896                 /* get control message */
 897                 if (FD_ISSET(udev_ctrl_get_fd(udev_ctrl), &readfds))
 898                         handle_ctrl_msg(udev_ctrl);
 899
 900                 /* get kernel uevent */
 901                 if (FD_ISSET(udev_monitor_get_fd(kernel_monitor), &readfds)) {
 902                         struct udev_device *dev;
 903
 904                         dev = udev_monitor_receive_device(kernel_monitor);
 905                         if (dev != NULL) {
 906                                 struct udev_event *event;
 907
 908                                 event = udev_event_new(dev);
 909                                 if (event != NULL)
 910                                         event_queue_insert(event);
 911                                 else
 912                                         udev_device_unref(dev);
 913                         }
 914                 }
 915
 916                 /* received a signal, clear our notification pipe */
 917                 if (FD_ISSET(signal_pipe[READ_END], &readfds)) {
 918                         char buf[256];
 919
 920                         read(signal_pipe[READ_END], &buf, sizeof(buf));
 921                 }
 922
 923                 /* rules directory inotify watch */
 924                 if ((inotify_fd >= 0) && FD_ISSET(inotify_fd, &readfds)) {
 925                         int nbytes;
 926
 927                         /* discard all possible events, we can just reload the config */
 928                         if ((ioctl(inotify_fd, FIONREAD, &nbytes) == 0) && nbytes > 0) {
 929                                 char *buf;
 930
 931                                 reload_config = 1;
 932                                 buf = malloc(nbytes);
 933                                 if (buf == NULL) {
 934                                         err(udev, "error getting buffer for inotify, disable watching\n");
 935                                         close(inotify_fd);
 936                                         inotify_fd = -1;
 937                                 }
 938                                 read(inotify_fd, buf, nbytes);
 939                                 free(buf);
 940                         }
 941                 }
 942
 943                 /* rules changed, set by inotify or a HUP signal */
 944                 if (reload_config) {
 945                         struct udev_rules *rules_new;
 946
 947                         reload_config = 0;
 948                         rules_new = udev_rules_new(udev, 1);
 949                         if (rules_new != NULL) {
 950                                 udev_rules_unref(rules);
 951                                 rules = rules_new;
 952                         }
 953                 }
 954
 955                 if (sigchilds_waiting) {
 956                         sigchilds_waiting = 0;
 957                         reap_sigchilds();
 958                 }
 959
 960                 if (run_exec_q) {
 961                         run_exec_q = 0;
 962                         if (!stop_exec_q)
 963                                 event_queue_manager(udev);
 964                 }
 965         }
 966         rc = 0;
 967
 968 exit:
 969         udev_rules_unref(rules);
 970
 971         if (signal_pipe[READ_END] >= 0)
 972                 close(signal_pipe[READ_END]);
 973         if (signal_pipe[WRITE_END] >= 0)
 974                 close(signal_pipe[WRITE_END]);
 975
 976         udev_ctrl_unref(udev_ctrl);
 977         if (inotify_fd >= 0)
 978                 close(inotify_fd);
 979         udev_monitor_unref(kernel_monitor);
 980
 981         udev_selinux_exit(udev);
 982         udev_unref(udev);
 983         logging_close();
 984         return rc;
 985 }