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 #include "udev-rules.h"
  40
  41 #define UDEVD_PRIORITY                  -4
  42 #define UDEV_PRIORITY                   -2
  43
  44 /* maximum limit of forked childs */
  45 #define UDEVD_MAX_CHILDS                256
  46
  47 static int debug;
  48
  49 static void log_fn(struct udev *udev, int priority,
  50                    const char *file, int line, const char *fn,
  51                    const char *format, va_list args)
  52 {
  53         if (debug) {
  54                 fprintf(stderr, "[%d] %s: ", (int) getpid(), fn);
  55                 vfprintf(stderr, format, args);
  56         } else {
  57                 vsyslog(priority, format, args);
  58         }
  59 }
  60
  61 static int debug_trace;
  62 static struct udev_rules rules;
  63 static struct udev_ctrl *udev_ctrl;
  64 static struct udev_monitor *kernel_monitor;
  65 static int inotify_fd = -1;
  66
  67 static int signal_pipe[2] = {-1, -1};
  68 static volatile int sigchilds_waiting;
  69 static volatile int udev_exit;
  70 static volatile int reload_config;
  71 static int run_exec_q;
  72 static int stop_exec_q;
  73 static int max_childs;
  74
  75 static struct udev_list_node exec_list;
  76 static struct udev_list_node running_list;
  77
  78 enum event_state {
  79         EVENT_QUEUED,
  80         EVENT_FINISHED,
  81         EVENT_FAILED,
  82 };
  83
  84 static struct udev_event *node_to_event(struct udev_list_node *node)
  85 {
  86         char *event;
  87
  88         event = (char *)node;
  89         event -= offsetof(struct udev_event, node);
  90         return (struct udev_event *)event;
  91 }
  92
  93 static void export_event_state(struct udev_event *event, enum event_state state)
  94 {
  95         char filename[UTIL_PATH_SIZE];
  96         char filename_failed[UTIL_PATH_SIZE];
  97         size_t start;
  98
  99         /* location of queue file */
 100         snprintf(filename, sizeof(filename), "%s/.udev/queue/%llu",
 101                  udev_get_dev_path(event->udev), udev_device_get_seqnum(event->dev));
 102
 103         /* location of failed file */
 104         util_strlcpy(filename_failed, udev_get_dev_path(event->udev), sizeof(filename_failed));
 105         util_strlcat(filename_failed, "/", sizeof(filename_failed));
 106         start = util_strlcat(filename_failed, ".udev/failed/", sizeof(filename_failed));
 107         util_strlcat(filename_failed, udev_device_get_devpath(event->dev), sizeof(filename_failed));
 108         util_path_encode(&filename_failed[start], sizeof(filename_failed) - start);
 109
 110         switch (state) {
 111         case EVENT_QUEUED:
 112                 unlink(filename_failed);
 113                 delete_path(event->udev, filename_failed);
 114                 create_path(event->udev, filename);
 115                 udev_selinux_setfscreatecon(event->udev, filename, S_IFLNK);
 116                 symlink(udev_device_get_devpath(event->dev), filename);
 117                 udev_selinux_resetfscreatecon(event->udev);
 118                 break;
 119         case EVENT_FINISHED:
 120                 if (udev_device_get_devpath_old(event->dev) != NULL) {
 121                         /* "move" event - rename failed file to current name, do not delete failed */
 122                         char filename_failed_old[UTIL_PATH_SIZE];
 123
 124                         util_strlcpy(filename_failed_old, udev_get_dev_path(event->udev), sizeof(filename_failed_old));
 125                         util_strlcat(filename_failed_old, "/", sizeof(filename_failed_old));
 126                         start = util_strlcat(filename_failed_old, ".udev/failed/", sizeof(filename_failed_old));
 127                         util_strlcat(filename_failed_old, udev_device_get_devpath_old(event->dev), sizeof(filename_failed_old));
 128                         util_path_encode(&filename_failed_old[start], sizeof(filename) - start);
 129
 130                         if (rename(filename_failed_old, filename_failed) == 0)
 131                                 info(event->udev, "renamed devpath, moved failed state of '%s' to %s'\n",
 132                                      udev_device_get_devpath_old(event->dev), udev_device_get_devpath(event->dev));
 133                 } else {
 134                         unlink(filename_failed);
 135                         delete_path(event->udev, filename_failed);
 136                 }
 137
 138                 unlink(filename);
 139                 delete_path(event->udev, filename);
 140                 break;
 141         case EVENT_FAILED:
 142                 /* move failed event to the failed directory */
 143                 create_path(event->udev, filename_failed);
 144                 rename(filename, filename_failed);
 145
 146                 /* clean up possibly empty queue directory */
 147                 delete_path(event->udev, filename);
 148                 break;
 149         }
 150
 151         return;
 152 }
 153
 154 static void event_queue_delete(struct udev_event *event)
 155 {
 156         udev_list_node_remove(&event->node);
 157
 158         /* mark as failed, if "add" event returns non-zero */
 159         if (event->exitstatus && strcmp(udev_device_get_action(event->dev), "add") == 0)
 160                 export_event_state(event, EVENT_FAILED);
 161         else
 162                 export_event_state(event, EVENT_FINISHED);
 163
 164         udev_device_unref(event->dev);
 165         udev_event_unref(event);
 166 }
 167
 168 static void asmlinkage event_sig_handler(int signum)
 169 {
 170         if (signum == SIGALRM)
 171                 exit(1);
 172 }
 173
 174 static void event_fork(struct udev_event *event)
 175 {
 176         pid_t pid;
 177         struct sigaction act;
 178         int err;
 179
 180         pid = fork();
 181         switch (pid) {
 182         case 0:
 183                 /* child */
 184                 udev_monitor_unref(kernel_monitor);
 185                 udev_ctrl_unref(udev_ctrl);
 186                 if (inotify_fd >= 0)
 187                         close(inotify_fd);
 188                 close(signal_pipe[READ_END]);
 189                 close(signal_pipe[WRITE_END]);
 190                 logging_close();
 191                 logging_init("udevd-event");
 192                 setpriority(PRIO_PROCESS, 0, UDEV_PRIORITY);
 193
 194                 /* set signal handlers */
 195                 memset(&act, 0x00, sizeof(act));
 196                 act.sa_handler = (void (*)(int)) event_sig_handler;
 197                 sigemptyset (&act.sa_mask);
 198                 act.sa_flags = 0;
 199                 sigaction(SIGALRM, &act, NULL);
 200
 201                 /* reset to default */
 202                 act.sa_handler = SIG_DFL;
 203                 sigaction(SIGINT, &act, NULL);
 204                 sigaction(SIGTERM, &act, NULL);
 205                 sigaction(SIGCHLD, &act, NULL);
 206                 sigaction(SIGHUP, &act, NULL);
 207
 208                 /* set timeout to prevent hanging processes */
 209                 alarm(UDEV_EVENT_TIMEOUT);
 210
 211                 /* apply rules, create node, symlinks */
 212                 err = udev_event_run(event, &rules);
 213
 214                 /* rules may change/disable the timeout */
 215                 if (udev_device_get_event_timeout(event->dev) >= 0)
 216                         alarm(udev_device_get_event_timeout(event->dev));
 217
 218                 /* execute RUN= */
 219                 if (err == 0 && !event->ignore_device && udev_get_run(event->udev))
 220                         udev_rules_run(event);
 221                 info(event->udev, "seq %llu exit with %i\n", udev_device_get_seqnum(event->dev), err);
 222                 logging_close();
 223                 if (err != 0)
 224                         exit(1);
 225                 exit(0);
 226         case -1:
 227                 err(event->udev, "fork of child failed: %m\n");
 228                 event_queue_delete(event);
 229                 break;
 230         default:
 231                 /* get SIGCHLD in main loop */
 232                 info(event->udev, "seq %llu forked, pid [%d], '%s' '%s', %ld seconds old\n",
 233                      udev_device_get_seqnum(event->dev),
 234                      pid,
 235                      udev_device_get_action(event->dev),
 236                      udev_device_get_subsystem(event->dev),
 237                      time(NULL) - event->queue_time);
 238                 event->pid = pid;
 239         }
 240 }
 241
 242 static void event_queue_insert(struct udev_event *event)
 243 {
 244         char filename[UTIL_PATH_SIZE];
 245         int fd;
 246
 247         event->queue_time = time(NULL);
 248
 249         export_event_state(event, EVENT_QUEUED);
 250         info(event->udev, "seq %llu queued, '%s' '%s'\n", udev_device_get_seqnum(event->dev),
 251              udev_device_get_action(event->dev), udev_device_get_subsystem(event->dev));
 252
 253         util_strlcpy(filename, udev_get_dev_path(event->udev), sizeof(filename));
 254         util_strlcat(filename, "/.udev/uevent_seqnum", sizeof(filename));
 255         fd = open(filename, O_WRONLY|O_TRUNC|O_CREAT, 0644);
 256         if (fd >= 0) {
 257                 char str[32];
 258                 int len;
 259
 260                 len = sprintf(str, "%llu\n", udev_device_get_seqnum(event->dev));
 261                 write(fd, str, len);
 262                 close(fd);
 263         }
 264
 265         /* run one event after the other in debug mode */
 266         if (debug_trace) {
 267                 udev_list_node_append(&event->node, &running_list);
 268                 event_fork(event);
 269                 waitpid(event->pid, NULL, 0);
 270                 event_queue_delete(event);
 271                 return;
 272         }
 273
 274         /* run all events with a timeout set immediately */
 275         if (udev_device_get_timeout(event->dev) > 0) {
 276                 udev_list_node_append(&event->node, &running_list);
 277                 event_fork(event);
 278                 return;
 279         }
 280
 281         udev_list_node_append(&event->node, &exec_list);
 282         run_exec_q = 1;
 283 }
 284
 285 static int mem_size_mb(void)
 286 {
 287         FILE* f;
 288         char buf[4096];
 289         long int memsize = -1;
 290
 291         f = fopen("/proc/meminfo", "r");
 292         if (f == NULL)
 293                 return -1;
 294
 295         while (fgets(buf, sizeof(buf), f) != NULL) {
 296                 long int value;
 297
 298                 if (sscanf(buf, "MemTotal: %ld kB", &value) == 1) {
 299                         memsize = value / 1024;
 300                         break;
 301                 }
 302         }
 303
 304         fclose(f);
 305         return memsize;
 306 }
 307
 308 static int compare_devpath(const char *running, const char *waiting)
 309 {
 310         int i;
 311
 312         for (i = 0; i < UTIL_PATH_SIZE; i++) {
 313                 /* identical device event found */
 314                 if (running[i] == '\0' && waiting[i] == '\0')
 315                         return 1;
 316
 317                 /* parent device event found */
 318                 if (running[i] == '\0' && waiting[i] == '/')
 319                         return 2;
 320
 321                 /* child device event found */
 322                 if (running[i] == '/' && waiting[i] == '\0')
 323                         return 3;
 324
 325                 /* no matching event */
 326                 if (running[i] != waiting[i])
 327                         break;
 328         }
 329
 330         return 0;
 331 }
 332
 333 /* lookup event for identical, parent, child, or physical device */
 334 static int devpath_busy(struct udev_event *event, int limit)
 335 {
 336         struct udev_list_node *loop;
 337         int childs_count = 0;
 338
 339         /* check exec-queue which may still contain delayed events we depend on */
 340         udev_list_node_foreach(loop, &exec_list) {
 341                 struct udev_event *loop_event = node_to_event(loop);
 342
 343                 /* skip ourself and all later events */
 344                 if (udev_device_get_seqnum(loop_event->dev) >= udev_device_get_seqnum(event->dev))
 345                         break;
 346
 347                 /* check our old name */
 348                 if (udev_device_get_devpath_old(event->dev) != NULL)
 349                         if (strcmp(udev_device_get_devpath(loop_event->dev), udev_device_get_devpath_old(event->dev)) == 0)
 350                                 return 2;
 351
 352                 /* check identical, parent, or child device event */
 353                 if (compare_devpath(udev_device_get_devpath(loop_event->dev), udev_device_get_devpath(event->dev)) != 0) {
 354                         dbg(event->udev, "%llu, device event still pending %llu (%s)\n",
 355                             udev_device_get_seqnum(event->dev),
 356                             udev_device_get_seqnum(loop_event->dev),
 357                             udev_device_get_devpath(loop_event->dev));
 358                         return 3;
 359                 }
 360
 361                 /* check for our major:minor number */
 362                 if (major(udev_device_get_devnum(event->dev)) > 0 &&
 363                     udev_device_get_devnum(loop_event->dev) == udev_device_get_devnum(event->dev) &&
 364                     strcmp(udev_device_get_subsystem(event->dev), udev_device_get_subsystem(loop_event->dev)) == 0) {
 365                         dbg(event->udev, "%llu, device event still pending %llu (%d:%d)\n",
 366                             udev_device_get_seqnum(event->dev),
 367                             udev_device_get_seqnum(loop_event->dev),
 368                             major(udev_device_get_devnum(loop_event->dev)), minor(udev_device_get_devnum(loop_event->dev)));
 369                         return 4;
 370                 }
 371
 372                 /* check physical device event (special case of parent) */
 373                 if (udev_device_get_physdevpath(event->dev) != NULL &&
 374                     strcmp(udev_device_get_action(event->dev), "add") == 0)
 375                         if (compare_devpath(udev_device_get_devpath(loop_event->dev),
 376                                             udev_device_get_physdevpath(event->dev)) != 0) {
 377                                 dbg(event->udev, "%llu, physical device event still pending %llu (%s)\n",
 378                                     udev_device_get_seqnum(event->dev),
 379                                     udev_device_get_seqnum(loop_event->dev),
 380                                     udev_device_get_devpath(loop_event->dev));
 381                                 return 5;
 382                         }
 383         }
 384
 385         /* check run queue for still running events */
 386         udev_list_node_foreach(loop, &running_list) {
 387                 struct udev_event *loop_event = node_to_event(loop);
 388
 389                 if (childs_count++ >= limit) {
 390                         info(event->udev, "%llu, maximum number (%i) of childs reached\n",
 391                              udev_device_get_seqnum(event->dev), childs_count);
 392                         return 1;
 393                 }
 394
 395                 /* check our old name */
 396                 if (udev_device_get_devpath_old(event->dev) != NULL)
 397                         if (strcmp(udev_device_get_devpath(loop_event->dev), udev_device_get_devpath_old(event->dev)) == 0)
 398                                 return 2;
 399
 400                 /* check identical, parent, or child device event */
 401                 if (compare_devpath(udev_device_get_devpath(loop_event->dev), udev_device_get_devpath(event->dev)) != 0) {
 402                         dbg(event->udev, "%llu, device event still running %llu (%s)\n",
 403                             udev_device_get_seqnum(event->dev),
 404                             udev_device_get_seqnum(loop_event->dev),
 405                             udev_device_get_devpath(loop_event->dev));
 406                         return 3;
 407                 }
 408
 409                 /* check for our major:minor number */
 410                 if (major(udev_device_get_devnum(event->dev)) > 0 &&
 411                     udev_device_get_devnum(loop_event->dev) == udev_device_get_devnum(event->dev) &&
 412                     strcmp(udev_device_get_subsystem(event->dev), udev_device_get_subsystem(loop_event->dev)) == 0) {
 413                         dbg(event->udev, "%llu, device event still pending %llu (%d:%d)\n",
 414                             udev_device_get_seqnum(event->dev),
 415                             udev_device_get_seqnum(loop_event->dev),
 416                             major(udev_device_get_devnum(loop_event->dev)), minor(udev_device_get_devnum(loop_event->dev)));
 417                         return 4;
 418                 }
 419
 420                 /* check physical device event (special case of parent) */
 421                 if (udev_device_get_physdevpath(event->dev) != NULL &&
 422                     strcmp(udev_device_get_action(event->dev), "add") == 0)
 423                         if (compare_devpath(udev_device_get_devpath(loop_event->dev),
 424                                             udev_device_get_physdevpath(event->dev)) != 0) {
 425                                 dbg(event->udev, "%llu, physical device event still pending %llu (%s)\n",
 426                                     udev_device_get_seqnum(event->dev),
 427                                     udev_device_get_seqnum(loop_event->dev),
 428                                     udev_device_get_devpath(loop_event->dev));
 429                                 return 5;
 430                         }
 431         }
 432         return 0;
 433 }
 434
 435 /* serializes events for the identical and parent and child devices */
 436 static void event_queue_manager(struct udev *udev)
 437 {
 438         struct udev_list_node *loop;
 439         struct udev_list_node *tmp;
 440
 441         if (udev_list_is_empty(&exec_list))
 442                 return;
 443
 444         udev_list_node_foreach_safe(loop, tmp, &exec_list) {
 445                 struct udev_event *loop_event = node_to_event(loop);
 446
 447                 /* serialize and wait for parent or child events */
 448                 if (devpath_busy(loop_event, max_childs) != 0) {
 449                         dbg(udev, "delay seq %llu (%s)\n",
 450                             udev_device_get_seqnum(loop_event->dev),
 451                             udev_device_get_devpath(loop_event->dev));
 452                         continue;
 453                 }
 454
 455                 /* move event to run list */
 456                 udev_list_node_remove(&loop_event->node);
 457                 udev_list_node_append(&loop_event->node, &running_list);
 458                 event_fork(loop_event);
 459                 dbg(udev, "moved seq %llu to running list\n", udev_device_get_seqnum(loop_event->dev));
 460         }
 461 }
 462
 463 /* receive the udevd message from userspace */
 464 static void handle_ctrl_msg(struct udev_ctrl *uctrl)
 465 {
 466         struct udev *udev = udev_ctrl_get_udev(uctrl);
 467         struct udev_ctrl_msg *ctrl_msg;
 468         const char *str;
 469         int i;
 470
 471         ctrl_msg = udev_ctrl_receive_msg(uctrl);
 472         if (ctrl_msg == NULL)
 473                 return;
 474
 475         i = udev_ctrl_get_set_log_level(ctrl_msg);
 476         if (i >= 0) {
 477                 info(udev, "udevd message (SET_LOG_PRIORITY) received, log_priority=%i\n", i);
 478                 udev_set_log_priority(udev, i);
 479         }
 480
 481         if (udev_ctrl_get_stop_exec_queue(ctrl_msg) > 0) {
 482                 info(udev, "udevd message (STOP_EXEC_QUEUE) received\n");
 483                 stop_exec_q = 1;
 484         }
 485
 486         if (udev_ctrl_get_start_exec_queue(ctrl_msg) > 0) {
 487                 info(udev, "udevd message (START_EXEC_QUEUE) received\n");
 488                 stop_exec_q = 0;
 489                 event_queue_manager(udev);
 490         }
 491
 492         if (udev_ctrl_get_reload_rules(ctrl_msg) > 0) {
 493                 info(udev, "udevd message (RELOAD_RULES) received\n");
 494                 reload_config = 1;
 495         }
 496
 497         str = udev_ctrl_get_set_env(ctrl_msg);
 498         if (str != NULL) {
 499                 char *key;
 500
 501                 key = strdup(str);
 502                 if (key != NULL) {
 503                         char *val;
 504
 505                         val = strchr(key, '=');
 506                         if (val != NULL) {
 507                                 val[0] = '\0';
 508                                 val = &val[1];
 509                                 if (val[0] == '\0') {
 510                                         info(udev, "udevd message (ENV) received, unset '%s'\n", key);
 511                                         udev_add_property(udev, key, NULL);
 512                                 } else {
 513                                         info(udev, "udevd message (ENV) received, set '%s=%s'\n", key, val);
 514                                         udev_add_property(udev, key, val);
 515                                 }
 516                         } else {
 517                                 err(udev, "wrong key format '%s'\n", key);
 518                         }
 519                         free(key);
 520                 }
 521         }
 522
 523         i = udev_ctrl_get_set_max_childs(ctrl_msg);
 524         if (i >= 0) {
 525                 info(udev, "udevd message (SET_MAX_CHILDS) received, max_childs=%i\n", i);
 526                 max_childs = i;
 527         }
 528
 529         udev_ctrl_msg_unref(ctrl_msg);
 530 }
 531
 532 static void asmlinkage sig_handler(int signum)
 533 {
 534         switch (signum) {
 535                 case SIGINT:
 536                 case SIGTERM:
 537                         udev_exit = 1;
 538                         break;
 539                 case SIGCHLD:
 540                         /* set flag, then write to pipe if needed */
 541                         sigchilds_waiting = 1;
 542                         break;
 543                 case SIGHUP:
 544                         reload_config = 1;
 545                         break;
 546         }
 547
 548         /* write to pipe, which will wakeup select() in our mainloop */
 549         write(signal_pipe[WRITE_END], "", 1);
 550 }
 551
 552 static void udev_done(int pid, int exitstatus)
 553 {
 554         struct udev_list_node *loop;
 555
 556         /* find event associated with pid and delete it */
 557         udev_list_node_foreach(loop, &running_list) {
 558                 struct udev_event *loop_event = node_to_event(loop);
 559
 560                 if (loop_event->pid == pid) {
 561                         info(loop_event->udev, "seq %llu cleanup, pid [%d], status %i, %ld seconds old\n",
 562                              udev_device_get_seqnum(loop_event->dev), loop_event->pid,
 563                              exitstatus, time(NULL) - loop_event->queue_time);
 564                         loop_event->exitstatus = exitstatus;
 565                         event_queue_delete(loop_event);
 566
 567                         /* there may be events waiting with the same devpath */
 568                         run_exec_q = 1;
 569                         return;
 570                 }
 571         }
 572 }
 573
 574 static void reap_sigchilds(void)
 575 {
 576         pid_t pid;
 577         int status;
 578
 579         while (1) {
 580                 pid = waitpid(-1, &status, WNOHANG);
 581                 if (pid <= 0)
 582                         break;
 583                 if (WIFEXITED(status))
 584                         status = WEXITSTATUS(status);
 585                 else if (WIFSIGNALED(status))
 586                         status = WTERMSIG(status) + 128;
 587                 else
 588                         status = 0;
 589                 udev_done(pid, status);
 590         }
 591 }
 592
 593 static void export_initial_seqnum(struct udev *udev)
 594 {
 595         char filename[UTIL_PATH_SIZE];
 596         int fd;
 597         char seqnum[32];
 598         ssize_t len = 0;
 599
 600         util_strlcpy(filename, udev_get_sys_path(udev), sizeof(filename));
 601         util_strlcat(filename, "/kernel/uevent_seqnum", sizeof(filename));
 602         fd = open(filename, O_RDONLY);
 603         if (fd >= 0) {
 604                 len = read(fd, seqnum, sizeof(seqnum)-1);
 605                 close(fd);
 606         }
 607         if (len <= 0) {
 608                 strcpy(seqnum, "0\n");
 609                 len = 3;
 610         }
 611         util_strlcpy(filename, udev_get_dev_path(udev), sizeof(filename));
 612         util_strlcat(filename, "/.udev/uevent_seqnum", sizeof(filename));
 613         create_path(udev, filename);
 614         fd = open(filename, O_WRONLY|O_TRUNC|O_CREAT, 0644);
 615         if (fd >= 0) {
 616                 write(fd, seqnum, len);
 617                 close(fd);
 618         }
 619 }
 620
 621 int main(int argc, char *argv[])
 622 {
 623         struct udev *udev;
 624         int err;
 625         int fd;
 626         struct sigaction act;
 627         fd_set readfds;
 628         const char *value;
 629         int daemonize = 0;
 630         static const struct option options[] = {
 631                 { "daemon", no_argument, NULL, 'd' },
 632                 { "debug-trace", no_argument, NULL, 't' },
 633                 { "debug", no_argument, NULL, 'D' },
 634                 { "help", no_argument, NULL, 'h' },
 635                 { "version", no_argument, NULL, 'V' },
 636                 {}
 637         };
 638         int rc = 1;
 639         int maxfd;
 640
 641         udev = udev_new();
 642         if (udev == NULL)
 643                 goto exit;
 644
 645         logging_init("udevd");
 646         udev_set_log_fn(udev, log_fn);
 647         info(udev, "version %s\n", VERSION);
 648         selinux_init(udev);
 649
 650         while (1) {
 651                 int option;
 652
 653                 option = getopt_long(argc, argv, "dDthV", options, NULL);
 654                 if (option == -1)
 655                         break;
 656
 657                 switch (option) {
 658                 case 'd':
 659                         daemonize = 1;
 660                         break;
 661                 case 't':
 662                         debug_trace = 1;
 663                         break;
 664                 case 'D':
 665                         debug = 1;
 666                         if (udev_get_log_priority(udev) < LOG_INFO)
 667                                 udev_set_log_priority(udev, LOG_INFO);
 668                         break;
 669                 case 'h':
 670                         printf("Usage: udevd [--help] [--daemon] [--debug-trace] [--debug] [--version]\n");
 671                         goto exit;
 672                 case 'V':
 673                         printf("%s\n", VERSION);
 674                         goto exit;
 675                 default:
 676                         goto exit;
 677                 }
 678         }
 679
 680         if (getuid() != 0) {
 681                 fprintf(stderr, "root privileges required\n");
 682                 err(udev, "root privileges required\n");
 683                 goto exit;
 684         }
 685
 686         /* make sure std{in,out,err} fd's are in a sane state */
 687         fd = open("/dev/null", O_RDWR);
 688         if (fd < 0) {
 689                 fprintf(stderr, "cannot open /dev/null\n");
 690                 err(udev, "cannot open /dev/null\n");
 691         }
 692         if (fd > STDIN_FILENO)
 693                 dup2(fd, STDIN_FILENO);
 694         if (write(STDOUT_FILENO, 0, 0) < 0)
 695                 dup2(fd, STDOUT_FILENO);
 696         if (write(STDERR_FILENO, 0, 0) < 0)
 697                 dup2(fd, STDERR_FILENO);
 698
 699         /* init control socket, bind() ensures, that only one udevd instance is running */
 700         udev_ctrl = udev_ctrl_new_from_socket(udev, UDEV_CTRL_SOCK_PATH);
 701         if (udev_ctrl == NULL) {
 702                 fprintf(stderr, "error initializing control socket");
 703                 err(udev, "error initializing udevd socket");
 704                 rc = 1;
 705                 goto exit;
 706         }
 707
 708         if (udev_ctrl_enable_receiving(udev_ctrl) < 0) {
 709                 fprintf(stderr, "error binding control socket, seems udevd is already running\n");
 710                 err(udev, "error binding control socket, seems udevd is already running\n");
 711                 rc = 1;
 712                 goto exit;
 713         }
 714
 715         kernel_monitor = udev_monitor_new_from_netlink(udev);
 716         if (kernel_monitor == NULL || udev_monitor_enable_receiving(kernel_monitor) < 0) {
 717                 fprintf(stderr, "error initializing netlink socket\n");
 718                 err(udev, "error initializing netlink socket\n");
 719                 rc = 3;
 720                 goto exit;
 721         }
 722         udev_monitor_set_receive_buffer_size(kernel_monitor, 128*1024*1024);
 723
 724         err = pipe(signal_pipe);
 725         if (err < 0) {
 726                 err(udev, "error getting pipes: %m\n");
 727                 goto exit;
 728         }
 729
 730         err = fcntl(signal_pipe[READ_END], F_GETFL, 0);
 731         if (err < 0) {
 732                 err(udev, "error fcntl on read pipe: %m\n");
 733                 goto exit;
 734         }
 735         err = fcntl(signal_pipe[READ_END], F_SETFL, err | O_NONBLOCK);
 736         if (err < 0) {
 737                 err(udev, "error fcntl on read pipe: %m\n");
 738                 goto exit;
 739         }
 740
 741         err = fcntl(signal_pipe[WRITE_END], F_GETFL, 0);
 742         if (err < 0) {
 743                 err(udev, "error fcntl on write pipe: %m\n");
 744                 goto exit;
 745         }
 746         err = fcntl(signal_pipe[WRITE_END], F_SETFL, err | O_NONBLOCK);
 747         if (err < 0) {
 748                 err(udev, "error fcntl on write pipe: %m\n");
 749                 goto exit;
 750         }
 751
 752         udev_list_init(&running_list);
 753         udev_list_init(&exec_list);
 754         udev_rules_init(udev, &rules, 1);
 755         export_initial_seqnum(udev);
 756
 757         if (daemonize) {
 758                 pid_t pid;
 759
 760                 pid = fork();
 761                 switch (pid) {
 762                 case 0:
 763                         dbg(udev, "daemonized fork running\n");
 764                         break;
 765                 case -1:
 766                         err(udev, "fork of daemon failed: %m\n");
 767                         rc = 4;
 768                         goto exit;
 769                 default:
 770                         dbg(udev, "child [%u] running, parent exits\n", pid);
 771                         rc = 0;
 772                         goto exit;
 773                 }
 774         }
 775
 776         /* redirect std{out,err} */
 777         if (!debug) {
 778                 dup2(fd, STDOUT_FILENO);
 779                 dup2(fd, STDERR_FILENO);
 780         }
 781         if (fd > STDERR_FILENO)
 782                 close(fd);
 783
 784         /* set scheduling priority for the daemon */
 785         setpriority(PRIO_PROCESS, 0, UDEVD_PRIORITY);
 786
 787         chdir("/");
 788         umask(022);
 789         setsid();
 790
 791         /* OOM_DISABLE == -17 */
 792         fd = open("/proc/self/oom_adj", O_RDWR);
 793         if (fd < 0)
 794                 err(udev, "error disabling OOM: %m\n");
 795         else {
 796                 write(fd, "-17", 3);
 797                 close(fd);
 798         }
 799
 800         fd = open("/dev/kmsg", O_WRONLY);
 801         if (fd > 0) {
 802                 const char *ver_str = "<6>udev: starting version " VERSION "\n";
 803                 char path[UTIL_PATH_SIZE];
 804                 struct stat statbuf;
 805
 806                 write(fd, ver_str, strlen(ver_str));
 807                 util_strlcpy(path, udev_get_sys_path(udev), sizeof(path));
 808                 util_strlcat(path, "/class/mem/null", sizeof(path));
 809                 if (lstat(path, &statbuf) == 0) {
 810                         if (S_ISDIR(statbuf.st_mode)) {
 811                                 const char *depr_str = "<6>udev: deprecated sysfs layout (kernel too old, "
 812                                                         "or CONFIG_SYSFS_DEPRECATED) is unsupported, some "
 813                                                         "udev features may fail\n";
 814
 815                                 write(fd, depr_str, strlen(depr_str));
 816                         }
 817                 }
 818                 close(fd);
 819         }
 820
 821         /* set signal handlers */
 822         memset(&act, 0x00, sizeof(struct sigaction));
 823         act.sa_handler = (void (*)(int)) sig_handler;
 824         sigemptyset(&act.sa_mask);
 825         act.sa_flags = SA_RESTART;
 826         sigaction(SIGINT, &act, NULL);
 827         sigaction(SIGTERM, &act, NULL);
 828         sigaction(SIGCHLD, &act, NULL);
 829         sigaction(SIGHUP, &act, NULL);
 830
 831         /* watch rules directory */
 832         inotify_fd = inotify_init();
 833         if (inotify_fd >= 0) {
 834                 if (udev_get_rules_path(udev) != NULL) {
 835                         inotify_add_watch(inotify_fd, udev_get_rules_path(udev),
 836                                           IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
 837                 } else {
 838                         char filename[PATH_MAX];
 839
 840                         inotify_add_watch(inotify_fd, UDEV_PREFIX "/lib/udev/rules.d",
 841                                           IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
 842                         inotify_add_watch(inotify_fd, SYSCONFDIR "/udev/rules.d",
 843                                           IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
 844
 845                         /* watch dynamic rules directory */
 846                         util_strlcpy(filename, udev_get_dev_path(udev), sizeof(filename));
 847                         util_strlcat(filename, "/.udev/rules.d", sizeof(filename));
 848                         inotify_add_watch(inotify_fd, filename,
 849                                           IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
 850                 }
 851         } else if (errno == ENOSYS)
 852                 err(udev, "the kernel does not support inotify, udevd can't monitor rules file changes\n");
 853         else
 854                 err(udev, "inotify_init failed: %m\n");
 855
 856         /* maximum limit of forked childs */
 857         value = getenv("UDEVD_MAX_CHILDS");
 858         if (value)
 859                 max_childs = strtoul(value, NULL, 10);
 860         else {
 861                 int memsize = mem_size_mb();
 862                 if (memsize > 0)
 863                         max_childs = 128 + (memsize / 4);
 864                 else
 865                         max_childs = UDEVD_MAX_CHILDS;
 866         }
 867         info(udev, "initialize max_childs to %u\n", max_childs);
 868
 869         maxfd = udev_ctrl_get_fd(udev_ctrl);
 870         maxfd = UDEV_MAX(maxfd, udev_monitor_get_fd(kernel_monitor));
 871         maxfd = UDEV_MAX(maxfd, signal_pipe[READ_END]);
 872         maxfd = UDEV_MAX(maxfd, inotify_fd);
 873         while (!udev_exit) {
 874                 int fdcount;
 875
 876                 FD_ZERO(&readfds);
 877                 FD_SET(signal_pipe[READ_END], &readfds);
 878                 FD_SET(udev_ctrl_get_fd(udev_ctrl), &readfds);
 879                 FD_SET(udev_monitor_get_fd(kernel_monitor), &readfds);
 880                 if (inotify_fd >= 0)
 881                         FD_SET(inotify_fd, &readfds);
 882                 fdcount = select(maxfd+1, &readfds, NULL, NULL, NULL);
 883                 if (fdcount < 0) {
 884                         if (errno != EINTR)
 885                                 err(udev, "error in select: %m\n");
 886                         continue;
 887                 }
 888
 889                 /* get control message */
 890                 if (FD_ISSET(udev_ctrl_get_fd(udev_ctrl), &readfds))
 891                         handle_ctrl_msg(udev_ctrl);
 892
 893                 /* get kernel uevent */
 894                 if (FD_ISSET(udev_monitor_get_fd(kernel_monitor), &readfds)) {
 895                         struct udev_device *dev;
 896
 897                         dev = udev_monitor_receive_device(kernel_monitor);
 898                         if (dev != NULL) {
 899                                 struct udev_event *event;
 900
 901                                 event = udev_event_new(dev);
 902                                 if (event != NULL)
 903                                         event_queue_insert(event);
 904                                 else
 905                                         udev_device_unref(dev);
 906                         }
 907                 }
 908
 909                 /* received a signal, clear our notification pipe */
 910                 if (FD_ISSET(signal_pipe[READ_END], &readfds)) {
 911                         char buf[256];
 912
 913                         read(signal_pipe[READ_END], &buf, sizeof(buf));
 914                 }
 915
 916                 /* rules directory inotify watch */
 917                 if ((inotify_fd >= 0) && FD_ISSET(inotify_fd, &readfds)) {
 918                         int nbytes;
 919
 920                         /* discard all possible events, we can just reload the config */
 921                         if ((ioctl(inotify_fd, FIONREAD, &nbytes) == 0) && nbytes > 0) {
 922                                 char *buf;
 923
 924                                 reload_config = 1;
 925                                 buf = malloc(nbytes);
 926                                 if (buf == NULL) {
 927                                         err(udev, "error getting buffer for inotify, disable watching\n");
 928                                         close(inotify_fd);
 929                                         inotify_fd = -1;
 930                                 }
 931                                 read(inotify_fd, buf, nbytes);
 932                                 free(buf);
 933                         }
 934                 }
 935
 936                 /* rules changed, set by inotify or a HUP signal */
 937                 if (reload_config) {
 938                         reload_config = 0;
 939                         udev_rules_cleanup(&rules);
 940                         udev_rules_init(udev, &rules, 1);
 941                 }
 942
 943                 if (sigchilds_waiting) {
 944                         sigchilds_waiting = 0;
 945                         reap_sigchilds();
 946                 }
 947
 948                 if (run_exec_q) {
 949                         run_exec_q = 0;
 950                         if (!stop_exec_q)
 951                                 event_queue_manager(udev);
 952                 }
 953         }
 954         rc = 0;
 955
 956 exit:
 957         udev_rules_cleanup(&rules);
 958
 959         if (signal_pipe[READ_END] >= 0)
 960                 close(signal_pipe[READ_END]);
 961         if (signal_pipe[WRITE_END] >= 0)
 962                 close(signal_pipe[WRITE_END]);
 963
 964         udev_ctrl_unref(udev_ctrl);
 965         if (inotify_fd >= 0)
 966                 close(inotify_fd);
 967         udev_monitor_unref(kernel_monitor);
 968
 969         selinux_exit(udev);
 970         udev_unref(udev);
 971         logging_close();
 972         return rc;
 973 }