udev/udevd.c

   1 /*
   2  * Copyright (C) 2004-2008 Kay Sievers <kay.sievers@vrfy.org>
   3  * Copyright (C) 2004 Chris Friesen <chris_friesen@sympatico.ca>
   4  *
   5  * This program is free software: you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation, either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 #include <stddef.h>
  20 #include <signal.h>
  21 #include <unistd.h>
  22 #include <errno.h>
  23 #include <stdio.h>
  24 #include <stdlib.h>
  25 #include <string.h>
  26 #include <ctype.h>
  27 #include <fcntl.h>
  28 #include <time.h>
  29 #include <getopt.h>
  30 #include <dirent.h>
  31 #include <sys/select.h>
  32 #include <sys/wait.h>
  33 #include <sys/stat.h>
  34 #include <sys/ioctl.h>
  35 #ifdef HAVE_INOTIFY
  36 #include <sys/inotify.h>
  37 #endif
  38
  39 #include "udev.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 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 static int childs;
  74 static struct udev_list_node event_list;
  75
  76 enum event_state {
  77         EVENT_QUEUED,
  78         EVENT_FINISHED,
  79         EVENT_FAILED,
  80 };
  81
  82 static struct udev_event *node_to_event(struct udev_list_node *node)
  83 {
  84         char *event;
  85
  86         event = (char *)node;
  87         event -= offsetof(struct udev_event, node);
  88         return (struct udev_event *)event;
  89 }
  90
  91 static void export_event_state(struct udev_event *event, enum event_state state)
  92 {
  93         char filename[UTIL_PATH_SIZE];
  94         char filename_failed[UTIL_PATH_SIZE];
  95         size_t start;
  96
  97         /* location of queue file */
  98         snprintf(filename, sizeof(filename), "%s/.udev/queue/%llu",
  99                  udev_get_dev_path(event->udev), udev_device_get_seqnum(event->dev));
 100
 101         /* location of failed file */
 102         util_strlcpy(filename_failed, udev_get_dev_path(event->udev), sizeof(filename_failed));
 103         util_strlcat(filename_failed, "/", sizeof(filename_failed));
 104         start = util_strlcat(filename_failed, ".udev/failed/", sizeof(filename_failed));
 105         util_strlcat(filename_failed, udev_device_get_devpath(event->dev), sizeof(filename_failed));
 106         util_path_encode(&filename_failed[start], sizeof(filename_failed) - start);
 107
 108         switch (state) {
 109         case EVENT_QUEUED:
 110                 if(unlink(filename_failed) == 0)
 111                         util_delete_path(event->udev, filename_failed);
 112                 util_create_path(event->udev, filename);
 113                 udev_selinux_setfscreatecon(event->udev, filename, S_IFLNK);
 114                 symlink(udev_device_get_devpath(event->dev), filename);
 115                 udev_selinux_resetfscreatecon(event->udev);
 116                 break;
 117         case EVENT_FINISHED:
 118                 if (udev_device_get_devpath_old(event->dev) != NULL) {
 119                         /* "move" event - rename failed file to current name, do not delete failed */
 120                         char filename_failed_old[UTIL_PATH_SIZE];
 121
 122                         util_strlcpy(filename_failed_old, udev_get_dev_path(event->udev), sizeof(filename_failed_old));
 123                         util_strlcat(filename_failed_old, "/", sizeof(filename_failed_old));
 124                         start = util_strlcat(filename_failed_old, ".udev/failed/", sizeof(filename_failed_old));
 125                         util_strlcat(filename_failed_old, udev_device_get_devpath_old(event->dev), sizeof(filename_failed_old));
 126                         util_path_encode(&filename_failed_old[start], sizeof(filename) - start);
 127
 128                         if (rename(filename_failed_old, filename_failed) == 0)
 129                                 info(event->udev, "renamed devpath, moved failed state of '%s' to %s'\n",
 130                                      udev_device_get_devpath_old(event->dev), udev_device_get_devpath(event->dev));
 131                 } else {
 132                         if (unlink(filename_failed) == 0)
 133                                 util_delete_path(event->udev, filename_failed);
 134                 }
 135
 136                 unlink(filename);
 137
 138                 /* clean up possibly empty queue directory */
 139                 if (udev_list_is_empty(&event_list))
 140                         util_delete_path(event->udev, filename);
 141                 break;
 142         case EVENT_FAILED:
 143                 /* move failed event to the failed directory */
 144                 util_create_path(event->udev, filename_failed);
 145                 rename(filename, filename_failed);
 146
 147                 /* clean up possibly empty queue directory */
 148                 if (udev_list_is_empty(&event_list))
 149                         util_delete_path(event->udev, filename);
 150                 break;
 151         }
 152
 153         return;
 154 }
 155
 156 static void event_queue_delete(struct udev_event *event)
 157 {
 158         udev_list_node_remove(&event->node);
 159
 160         /* mark as failed, if "add" event returns non-zero */
 161         if (event->exitstatus && strcmp(udev_device_get_action(event->dev), "add") == 0)
 162                 export_event_state(event, EVENT_FAILED);
 163         else
 164                 export_event_state(event, EVENT_FINISHED);
 165
 166         udev_device_unref(event->dev);
 167         udev_event_unref(event);
 168 }
 169
 170 static void asmlinkage event_sig_handler(int signum)
 171 {
 172         if (signum == SIGALRM)
 173                 exit(1);
 174 }
 175
 176 static void event_fork(struct udev_event *event)
 177 {
 178         pid_t pid;
 179         struct sigaction act;
 180         int err;
 181
 182         if (debug_trace) {
 183                 event->trace = 1;
 184                 fprintf(stderr, "fork %s (%llu)\n",
 185                        udev_device_get_syspath(event->dev),
 186                        udev_device_get_seqnum(event->dev));
 187         }
 188
 189         pid = fork();
 190         switch (pid) {
 191         case 0:
 192                 /* child */
 193                 udev_monitor_unref(kernel_monitor);
 194                 udev_ctrl_unref(udev_ctrl);
 195                 if (inotify_fd >= 0)
 196                         close(inotify_fd);
 197                 close(signal_pipe[READ_END]);
 198                 close(signal_pipe[WRITE_END]);
 199                 logging_close();
 200                 logging_init("udevd-event");
 201                 setpriority(PRIO_PROCESS, 0, UDEV_PRIORITY);
 202
 203                 /* set signal handlers */
 204                 memset(&act, 0x00, sizeof(act));
 205                 act.sa_handler = (void (*)(int)) event_sig_handler;
 206                 sigemptyset (&act.sa_mask);
 207                 act.sa_flags = 0;
 208                 sigaction(SIGALRM, &act, NULL);
 209
 210                 /* reset to default */
 211                 act.sa_handler = SIG_DFL;
 212                 sigaction(SIGINT, &act, NULL);
 213                 sigaction(SIGTERM, &act, NULL);
 214                 sigaction(SIGCHLD, &act, NULL);
 215                 sigaction(SIGHUP, &act, NULL);
 216
 217                 /* set timeout to prevent hanging processes */
 218                 alarm(UDEV_EVENT_TIMEOUT);
 219
 220                 /* apply rules, create node, symlinks */
 221                 err = udev_event_execute_rules(event, rules);
 222
 223                 /* rules may change/disable the timeout */
 224                 if (udev_device_get_event_timeout(event->dev) >= 0)
 225                         alarm(udev_device_get_event_timeout(event->dev));
 226
 227                 /* execute RUN= */
 228                 if (err == 0 && !event->ignore_device && udev_get_run(event->udev))
 229                         udev_event_execute_run(event);
 230
 231                 info(event->udev, "seq %llu exit with %i\n", udev_device_get_seqnum(event->dev), err);
 232                 logging_close();
 233                 if (err != 0)
 234                         exit(1);
 235                 exit(0);
 236         case -1:
 237                 err(event->udev, "fork of child failed: %m\n");
 238                 event_queue_delete(event);
 239                 break;
 240         default:
 241                 /* get SIGCHLD in main loop */
 242                 info(event->udev, "seq %llu forked, pid [%d], '%s' '%s', %ld seconds old\n",
 243                      udev_device_get_seqnum(event->dev),
 244                      pid,
 245                      udev_device_get_action(event->dev),
 246                      udev_device_get_subsystem(event->dev),
 247                      time(NULL) - event->queue_time);
 248                 event->pid = pid;
 249                 childs++;
 250         }
 251 }
 252
 253 static void event_queue_insert(struct udev_event *event)
 254 {
 255         char filename[UTIL_PATH_SIZE];
 256         int fd;
 257
 258         event->queue_time = time(NULL);
 259
 260         export_event_state(event, EVENT_QUEUED);
 261         info(event->udev, "seq %llu queued, '%s' '%s'\n", udev_device_get_seqnum(event->dev),
 262              udev_device_get_action(event->dev), udev_device_get_subsystem(event->dev));
 263
 264         util_strlcpy(filename, udev_get_dev_path(event->udev), sizeof(filename));
 265         util_strlcat(filename, "/.udev/uevent_seqnum", sizeof(filename));
 266         fd = open(filename, O_WRONLY|O_TRUNC|O_CREAT, 0644);
 267         if (fd >= 0) {
 268                 char str[32];
 269                 int len;
 270
 271                 len = sprintf(str, "%llu\n", udev_device_get_seqnum(event->dev));
 272                 write(fd, str, len);
 273                 close(fd);
 274         }
 275
 276
 277         udev_list_node_append(&event->node, &event_list);
 278         run_exec_q = 1;
 279
 280         /* run all events with a timeout set immediately */
 281         if (udev_device_get_timeout(event->dev) > 0) {
 282                 event_fork(event);
 283                 return;
 284         }
 285 }
 286
 287 static int mem_size_mb(void)
 288 {
 289         FILE* f;
 290         char buf[4096];
 291         long int memsize = -1;
 292
 293         f = fopen("/proc/meminfo", "r");
 294         if (f == NULL)
 295                 return -1;
 296
 297         while (fgets(buf, sizeof(buf), f) != NULL) {
 298                 long int value;
 299
 300                 if (sscanf(buf, "MemTotal: %ld kB", &value) == 1) {
 301                         memsize = value / 1024;
 302                         break;
 303                 }
 304         }
 305
 306         fclose(f);
 307         return memsize;
 308 }
 309
 310 static int compare_devpath(const char *running, const char *waiting)
 311 {
 312         int i = 0;
 313
 314         while (running[i] != '\0' && running[i] == waiting[i])
 315                 i++;
 316
 317         /* identical device event found */
 318         if (running[i] == '\0' && waiting[i] == '\0')
 319                 return 1;
 320
 321         /* parent device event found */
 322         if (running[i] == '\0' && waiting[i] == '/')
 323                 return 2;
 324
 325         /* child device event found */
 326         if (running[i] == '/' && waiting[i] == '\0')
 327                 return 3;
 328
 329         /* no matching event */
 330         return 0;
 331 }
 332
 333 /* lookup event for identical, parent, child, or physical device */
 334 static int devpath_busy(struct udev_event *event)
 335 {
 336         struct udev_list_node *loop;
 337
 338         if (event->delaying_seqnum > 0) {
 339         }
 340         /* check if queue contains events we depend on */
 341         udev_list_node_foreach(loop, &event_list) {
 342                 struct udev_event *loop_event = node_to_event(loop);
 343
 344                 /* we already found a later event, earlier can not block us, no need to check again */
 345                 if (udev_device_get_seqnum(loop_event->dev) < event->delaying_seqnum)
 346                         continue;
 347
 348                 /* event we checked earlier still exists, no need to check again */
 349                 if (udev_device_get_seqnum(loop_event->dev) == event->delaying_seqnum)
 350                         return 2;
 351
 352                 /* found ourself, no later event can block us */
 353                 if (udev_device_get_seqnum(loop_event->dev) >= udev_device_get_seqnum(event->dev))
 354                         break;
 355
 356                 /* check our old name */
 357                 if (udev_device_get_devpath_old(event->dev) != NULL)
 358                         if (strcmp(udev_device_get_devpath(loop_event->dev), udev_device_get_devpath_old(event->dev)) == 0) {
 359                                 event->delaying_seqnum = udev_device_get_seqnum(loop_event->dev);
 360                                 return 3;
 361                         }
 362
 363                 /* check identical, parent, or child device event */
 364                 if (compare_devpath(udev_device_get_devpath(loop_event->dev), udev_device_get_devpath(event->dev)) != 0) {
 365                         dbg(event->udev, "%llu, device event still pending %llu (%s)\n",
 366                             udev_device_get_seqnum(event->dev),
 367                             udev_device_get_seqnum(loop_event->dev),
 368                             udev_device_get_devpath(loop_event->dev));
 369                         event->delaying_seqnum = udev_device_get_seqnum(loop_event->dev);
 370                         return 4;
 371                 }
 372
 373                 /* check for our major:minor number */
 374                 if (major(udev_device_get_devnum(event->dev)) > 0 &&
 375                     udev_device_get_devnum(loop_event->dev) == udev_device_get_devnum(event->dev) &&
 376                     strcmp(udev_device_get_subsystem(event->dev), udev_device_get_subsystem(loop_event->dev)) == 0) {
 377                         dbg(event->udev, "%llu, device event still pending %llu (%d:%d)\n",
 378                             udev_device_get_seqnum(event->dev),
 379                             udev_device_get_seqnum(loop_event->dev),
 380                             major(udev_device_get_devnum(loop_event->dev)), minor(udev_device_get_devnum(loop_event->dev)));
 381                         event->delaying_seqnum = udev_device_get_seqnum(loop_event->dev);
 382                         return 5;
 383                 }
 384
 385                 /* check physical device event (special case of parent) */
 386                 if (udev_device_get_physdevpath(event->dev) != NULL &&
 387                     strcmp(udev_device_get_action(event->dev), "add") == 0)
 388                         if (compare_devpath(udev_device_get_devpath(loop_event->dev),
 389                                             udev_device_get_physdevpath(event->dev)) != 0) {
 390                                 dbg(event->udev, "%llu, physical device event still pending %llu (%s)\n",
 391                                     udev_device_get_seqnum(event->dev),
 392                                     udev_device_get_seqnum(loop_event->dev),
 393                                     udev_device_get_devpath(loop_event->dev));
 394                                 event->delaying_seqnum = udev_device_get_seqnum(loop_event->dev);
 395                                 return 6;
 396                         }
 397         }
 398         return 0;
 399 }
 400
 401 /* serializes events for the identical and parent and child devices */
 402 static void event_queue_manager(struct udev *udev)
 403 {
 404         struct udev_list_node *loop;
 405         struct udev_list_node *tmp;
 406
 407         if (udev_list_is_empty(&event_list)) {
 408                 if (childs > 0) {
 409                         err(udev, "event list empty, but childs count is %i", childs);
 410                         childs = 0;
 411                 }
 412                 return;
 413         }
 414
 415         udev_list_node_foreach_safe(loop, tmp, &event_list) {
 416                 struct udev_event *loop_event = node_to_event(loop);
 417
 418                 if (childs >= max_childs) {
 419                         info(udev, "maximum number (%i) of childs reached\n", childs);
 420                         break;
 421                 }
 422
 423                 if (loop_event->pid != 0)
 424                         continue;
 425
 426                 /* do not start event if parent or child event is still running */
 427                 if (devpath_busy(loop_event) != 0) {
 428                         dbg(udev, "delay seq %llu (%s)\n",
 429                             udev_device_get_seqnum(loop_event->dev),
 430                             udev_device_get_devpath(loop_event->dev));
 431                         continue;
 432                 }
 433
 434                 event_fork(loop_event);
 435                 dbg(udev, "moved seq %llu to running list\n", udev_device_get_seqnum(loop_event->dev));
 436         }
 437 }
 438
 439 /* receive the udevd message from userspace */
 440 static void handle_ctrl_msg(struct udev_ctrl *uctrl)
 441 {
 442         struct udev *udev = udev_ctrl_get_udev(uctrl);
 443         struct udev_ctrl_msg *ctrl_msg;
 444         const char *str;
 445         int i;
 446
 447         ctrl_msg = udev_ctrl_receive_msg(uctrl);
 448         if (ctrl_msg == NULL)
 449                 return;
 450
 451         i = udev_ctrl_get_set_log_level(ctrl_msg);
 452         if (i >= 0) {
 453                 info(udev, "udevd message (SET_LOG_PRIORITY) received, log_priority=%i\n", i);
 454                 udev_set_log_priority(udev, i);
 455         }
 456
 457         if (udev_ctrl_get_stop_exec_queue(ctrl_msg) > 0) {
 458                 info(udev, "udevd message (STOP_EXEC_QUEUE) received\n");
 459                 stop_exec_q = 1;
 460         }
 461
 462         if (udev_ctrl_get_start_exec_queue(ctrl_msg) > 0) {
 463                 info(udev, "udevd message (START_EXEC_QUEUE) received\n");
 464                 stop_exec_q = 0;
 465                 event_queue_manager(udev);
 466         }
 467
 468         if (udev_ctrl_get_reload_rules(ctrl_msg) > 0) {
 469                 info(udev, "udevd message (RELOAD_RULES) received\n");
 470                 reload_config = 1;
 471         }
 472
 473         str = udev_ctrl_get_set_env(ctrl_msg);
 474         if (str != NULL) {
 475                 char *key;
 476
 477                 key = strdup(str);
 478                 if (key != NULL) {
 479                         char *val;
 480
 481                         val = strchr(key, '=');
 482                         if (val != NULL) {
 483                                 val[0] = '\0';
 484                                 val = &val[1];
 485                                 if (val[0] == '\0') {
 486                                         info(udev, "udevd message (ENV) received, unset '%s'\n", key);
 487                                         udev_add_property(udev, key, NULL);
 488                                 } else {
 489                                         info(udev, "udevd message (ENV) received, set '%s=%s'\n", key, val);
 490                                         udev_add_property(udev, key, val);
 491                                 }
 492                         } else {
 493                                 err(udev, "wrong key format '%s'\n", key);
 494                         }
 495                         free(key);
 496                 }
 497         }
 498
 499         i = udev_ctrl_get_set_max_childs(ctrl_msg);
 500         if (i >= 0) {
 501                 info(udev, "udevd message (SET_MAX_CHILDS) received, max_childs=%i\n", i);
 502                 max_childs = i;
 503         }
 504         udev_ctrl_msg_unref(ctrl_msg);
 505 }
 506
 507 static void asmlinkage sig_handler(int signum)
 508 {
 509         switch (signum) {
 510                 case SIGINT:
 511                 case SIGTERM:
 512                         udev_exit = 1;
 513                         break;
 514                 case SIGCHLD:
 515                         /* set flag, then write to pipe if needed */
 516                         sigchilds_waiting = 1;
 517                         break;
 518                 case SIGHUP:
 519                         reload_config = 1;
 520                         break;
 521         }
 522
 523         /* write to pipe, which will wakeup select() in our mainloop */
 524         write(signal_pipe[WRITE_END], "", 1);
 525 }
 526
 527 static void udev_done(int pid, int exitstatus)
 528 {
 529         struct udev_list_node *loop;
 530
 531         /* find event associated with pid and delete it */
 532         udev_list_node_foreach(loop, &event_list) {
 533                 struct udev_event *loop_event = node_to_event(loop);
 534
 535                 if (loop_event->pid == pid) {
 536                         info(loop_event->udev, "seq %llu cleanup, pid [%d], status %i, %ld seconds old\n",
 537                              udev_device_get_seqnum(loop_event->dev), loop_event->pid,
 538                              exitstatus, time(NULL) - loop_event->queue_time);
 539                         loop_event->exitstatus = exitstatus;
 540                         if (debug_trace)
 541                                 fprintf(stderr, "exit %s (%llu)\n",
 542                                        udev_device_get_syspath(loop_event->dev),
 543                                        udev_device_get_seqnum(loop_event->dev));
 544                         event_queue_delete(loop_event);
 545                         childs--;
 546
 547                         /* there may be dependent events waiting */
 548                         run_exec_q = 1;
 549                         return;
 550                 }
 551         }
 552 }
 553
 554 static void reap_sigchilds(void)
 555 {
 556         pid_t pid;
 557         int status;
 558
 559         while (1) {
 560                 pid = waitpid(-1, &status, WNOHANG);
 561                 if (pid <= 0)
 562                         break;
 563                 if (WIFEXITED(status))
 564                         status = WEXITSTATUS(status);
 565                 else if (WIFSIGNALED(status))
 566                         status = WTERMSIG(status) + 128;
 567                 else
 568                         status = 0;
 569                 udev_done(pid, status);
 570         }
 571 }
 572
 573 static void cleanup_queue_dir(struct udev *udev)
 574 {
 575         char dirname[UTIL_PATH_SIZE];
 576         char filename[UTIL_PATH_SIZE];
 577         DIR *dir;
 578
 579         util_strlcpy(filename, udev_get_dev_path(udev), sizeof(filename));
 580         util_strlcat(filename, "/.udev/uevent_seqnum", sizeof(filename));
 581         unlink(filename);
 582
 583         util_strlcpy(dirname, udev_get_dev_path(udev), sizeof(dirname));
 584         util_strlcat(dirname, "/.udev/queue", sizeof(dirname));
 585         dir = opendir(dirname);
 586         if (dir != NULL) {
 587                 while (1) {
 588                         struct dirent *dent;
 589
 590                         dent = readdir(dir);
 591                         if (dent == NULL || dent->d_name[0] == '\0')
 592                                 break;
 593                         if (dent->d_name[0] == '.')
 594                                 continue;
 595                         util_strlcpy(filename, dirname, sizeof(filename));
 596                         util_strlcat(filename, "/", sizeof(filename));
 597                         util_strlcat(filename, dent->d_name, sizeof(filename));
 598                         unlink(filename);
 599                 }
 600                 closedir(dir);
 601                 rmdir(dirname);
 602         }
 603 }
 604
 605 static void export_initial_seqnum(struct udev *udev)
 606 {
 607         char filename[UTIL_PATH_SIZE];
 608         int fd;
 609         char seqnum[32];
 610         ssize_t len = 0;
 611
 612         util_strlcpy(filename, udev_get_sys_path(udev), sizeof(filename));
 613         util_strlcat(filename, "/kernel/uevent_seqnum", sizeof(filename));
 614         fd = open(filename, O_RDONLY);
 615         if (fd >= 0) {
 616                 len = read(fd, seqnum, sizeof(seqnum)-1);
 617                 close(fd);
 618         }
 619         if (len <= 0) {
 620                 strcpy(seqnum, "0\n");
 621                 len = 3;
 622         }
 623         util_strlcpy(filename, udev_get_dev_path(udev), sizeof(filename));
 624         util_strlcat(filename, "/.udev/uevent_seqnum", sizeof(filename));
 625         util_create_path(udev, filename);
 626         fd = open(filename, O_WRONLY|O_TRUNC|O_CREAT, 0644);
 627         if (fd >= 0) {
 628                 write(fd, seqnum, len);
 629                 close(fd);
 630         }
 631 }
 632
 633 int main(int argc, char *argv[])
 634 {
 635         struct udev *udev;
 636         int err;
 637         int fd;
 638         struct sigaction act;
 639         fd_set readfds;
 640         const char *value;
 641         int daemonize = 0;
 642         int resolve_names = 1;
 643         static const struct option options[] = {
 644                 { "daemon", no_argument, NULL, 'd' },
 645                 { "debug-trace", no_argument, NULL, 't' },
 646                 { "debug", no_argument, NULL, 'D' },
 647                 { "help", no_argument, NULL, 'h' },
 648                 { "version", no_argument, NULL, 'V' },
 649                 { "resolve-names", required_argument, NULL, 'N' },
 650                 {}
 651         };
 652         int rc = 1;
 653         int maxfd;
 654
 655         udev = udev_new();
 656         if (udev == NULL)
 657                 goto exit;
 658
 659         logging_init("udevd");
 660         udev_set_log_fn(udev, log_fn);
 661         info(udev, "version %s\n", VERSION);
 662         udev_selinux_init(udev);
 663
 664         while (1) {
 665                 int option;
 666
 667                 option = getopt_long(argc, argv, "dDthV", options, NULL);
 668                 if (option == -1)
 669                         break;
 670
 671                 switch (option) {
 672                 case 'd':
 673                         daemonize = 1;
 674                         break;
 675                 case 't':
 676                         debug_trace = 1;
 677                         break;
 678                 case 'D':
 679                         debug = 1;
 680                         if (udev_get_log_priority(udev) < LOG_INFO)
 681                                 udev_set_log_priority(udev, LOG_INFO);
 682                         break;
 683                 case 'N':
 684                         if (strcmp (optarg, "early") == 0) {
 685                                 resolve_names = 1;
 686                         } else if (strcmp (optarg, "late") == 0) {
 687                                 resolve_names = 0;
 688                         } else if (strcmp (optarg, "never") == 0) {
 689                                 resolve_names = -1;
 690                         } else {
 691                                 fprintf(stderr, "resolve-names must be early, late or never\n");
 692                                 err(udev, "resolve-names must be early, late or never\n");
 693                                 goto exit;
 694                         }
 695                         break;
 696                 case 'h':
 697                         printf("Usage: udevd [--help] [--daemon] [--debug-trace] [--debug] [--resolve-names=early|late|never] [--version]\n");
 698                         goto exit;
 699                 case 'V':
 700                         printf("%s\n", VERSION);
 701                         goto exit;
 702                 default:
 703                         goto exit;
 704                 }
 705         }
 706
 707         if (getuid() != 0) {
 708                 fprintf(stderr, "root privileges required\n");
 709                 err(udev, "root privileges required\n");
 710                 goto exit;
 711         }
 712
 713         /* make sure std{in,out,err} fd's are in a sane state */
 714         fd = open("/dev/null", O_RDWR);
 715         if (fd < 0) {
 716                 fprintf(stderr, "cannot open /dev/null\n");
 717                 err(udev, "cannot open /dev/null\n");
 718         }
 719         if (write(STDOUT_FILENO, 0, 0) < 0)
 720                 dup2(fd, STDOUT_FILENO);
 721         if (write(STDERR_FILENO, 0, 0) < 0)
 722                 dup2(fd, STDERR_FILENO);
 723
 724         /* init control socket, bind() ensures, that only one udevd instance is running */
 725         udev_ctrl = udev_ctrl_new_from_socket(udev, UDEV_CTRL_SOCK_PATH);
 726         if (udev_ctrl == NULL) {
 727                 fprintf(stderr, "error initializing control socket");
 728                 err(udev, "error initializing udevd socket");
 729                 rc = 1;
 730                 goto exit;
 731         }
 732
 733         if (udev_ctrl_enable_receiving(udev_ctrl) < 0) {
 734                 fprintf(stderr, "error binding control socket, seems udevd is already running\n");
 735                 err(udev, "error binding control socket, seems udevd is already running\n");
 736                 rc = 1;
 737                 goto exit;
 738         }
 739
 740         kernel_monitor = udev_monitor_new_from_netlink(udev);
 741         if (kernel_monitor == NULL || udev_monitor_enable_receiving(kernel_monitor) < 0) {
 742                 fprintf(stderr, "error initializing netlink socket\n");
 743                 err(udev, "error initializing netlink socket\n");
 744                 rc = 3;
 745                 goto exit;
 746         }
 747         udev_monitor_set_receive_buffer_size(kernel_monitor, 128*1024*1024);
 748
 749         err = pipe(signal_pipe);
 750         if (err < 0) {
 751                 err(udev, "error getting pipes: %m\n");
 752                 goto exit;
 753         }
 754
 755         err = fcntl(signal_pipe[READ_END], F_GETFL, 0);
 756         if (err < 0) {
 757                 err(udev, "error fcntl on read pipe: %m\n");
 758                 goto exit;
 759         }
 760         err = fcntl(signal_pipe[READ_END], F_SETFL, err | O_NONBLOCK);
 761         if (err < 0) {
 762                 err(udev, "error fcntl on read pipe: %m\n");
 763                 goto exit;
 764         }
 765
 766         err = fcntl(signal_pipe[WRITE_END], F_GETFL, 0);
 767         if (err < 0) {
 768                 err(udev, "error fcntl on write pipe: %m\n");
 769                 goto exit;
 770         }
 771         err = fcntl(signal_pipe[WRITE_END], F_SETFL, err | O_NONBLOCK);
 772         if (err < 0) {
 773                 err(udev, "error fcntl on write pipe: %m\n");
 774                 goto exit;
 775         }
 776
 777         rules = udev_rules_new(udev, resolve_names);
 778         if (rules == NULL) {
 779                 err(udev, "error reading rules\n");
 780                 goto exit;
 781         }
 782         udev_list_init(&event_list);
 783         cleanup_queue_dir(udev);
 784         export_initial_seqnum(udev);
 785
 786         if (daemonize) {
 787                 pid_t pid;
 788
 789                 pid = fork();
 790                 switch (pid) {
 791                 case 0:
 792                         dbg(udev, "daemonized fork running\n");
 793                         break;
 794                 case -1:
 795                         err(udev, "fork of daemon failed: %m\n");
 796                         rc = 4;
 797                         goto exit;
 798                 default:
 799                         dbg(udev, "child [%u] running, parent exits\n", pid);
 800                         rc = 0;
 801                         goto exit;
 802                 }
 803         }
 804
 805         /* redirect std{out,err} */
 806         if (!debug && !debug_trace) {
 807                 dup2(fd, STDIN_FILENO);
 808                 dup2(fd, STDOUT_FILENO);
 809                 dup2(fd, STDERR_FILENO);
 810         }
 811         if (fd > STDERR_FILENO)
 812                 close(fd);
 813
 814         /* set scheduling priority for the daemon */
 815         setpriority(PRIO_PROCESS, 0, UDEVD_PRIORITY);
 816
 817         chdir("/");
 818         umask(022);
 819         setsid();
 820
 821         /* OOM_DISABLE == -17 */
 822         fd = open("/proc/self/oom_adj", O_RDWR);
 823         if (fd < 0)
 824                 err(udev, "error disabling OOM: %m\n");
 825         else {
 826                 write(fd, "-17", 3);
 827                 close(fd);
 828         }
 829
 830         fd = open("/dev/kmsg", O_WRONLY);
 831         if (fd > 0) {
 832                 const char *ver_str = "<6>udev: starting version " VERSION "\n";
 833                 char path[UTIL_PATH_SIZE];
 834                 struct stat statbuf;
 835
 836                 write(fd, ver_str, strlen(ver_str));
 837                 util_strlcpy(path, udev_get_sys_path(udev), sizeof(path));
 838                 util_strlcat(path, "/class/mem/null", sizeof(path));
 839                 if (lstat(path, &statbuf) == 0) {
 840                         if (S_ISDIR(statbuf.st_mode)) {
 841                                 const char *depr_str =
 842                                         "<6>udev: deprecated sysfs layout; update the kernel or "
 843                                         "disable CONFIG_SYSFS_DEPRECATED; some udev features will "
 844                                         "not work correctly\n";
 845
 846                                 write(fd, depr_str, strlen(depr_str));
 847                         }
 848                 }
 849                 close(fd);
 850         }
 851
 852         /* set signal handlers */
 853         memset(&act, 0x00, sizeof(struct sigaction));
 854         act.sa_handler = (void (*)(int)) sig_handler;
 855         sigemptyset(&act.sa_mask);
 856         act.sa_flags = SA_RESTART;
 857         sigaction(SIGINT, &act, NULL);
 858         sigaction(SIGTERM, &act, NULL);
 859         sigaction(SIGCHLD, &act, NULL);
 860         sigaction(SIGHUP, &act, NULL);
 861
 862         /* watch rules directory */
 863         inotify_fd = inotify_init();
 864         if (inotify_fd >= 0) {
 865                 if (udev_get_rules_path(udev) != NULL) {
 866                         inotify_add_watch(inotify_fd, udev_get_rules_path(udev),
 867                                           IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
 868                 } else {
 869                         char filename[UTIL_PATH_SIZE];
 870
 871                         inotify_add_watch(inotify_fd, UDEV_PREFIX "/lib/udev/rules.d",
 872                                           IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
 873                         inotify_add_watch(inotify_fd, SYSCONFDIR "/udev/rules.d",
 874                                           IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
 875
 876                         /* watch dynamic rules directory */
 877                         util_strlcpy(filename, udev_get_dev_path(udev), sizeof(filename));
 878                         util_strlcat(filename, "/.udev/rules.d", sizeof(filename));
 879                         inotify_add_watch(inotify_fd, filename,
 880                                           IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
 881                 }
 882         } else if (errno == ENOSYS)
 883                 info(udev, "unable to use inotify, udevd will not monitor rule files changes\n");
 884         else
 885                 err(udev, "inotify_init failed: %m\n");
 886
 887         /* in trace mode run one event after the other */
 888         if (debug_trace) {
 889                 max_childs = 1;
 890         } else {
 891                 int memsize = mem_size_mb();
 892                 if (memsize > 0)
 893                         max_childs = 128 + (memsize / 4);
 894                 else
 895                         max_childs = UDEVD_MAX_CHILDS;
 896         }
 897         /* possibly overwrite maximum limit of executed events */
 898         value = getenv("UDEVD_MAX_CHILDS");
 899         if (value)
 900                 max_childs = strtoul(value, NULL, 10);
 901         info(udev, "initialize max_childs to %u\n", max_childs);
 902
 903         maxfd = udev_ctrl_get_fd(udev_ctrl);
 904         maxfd = UDEV_MAX(maxfd, udev_monitor_get_fd(kernel_monitor));
 905         maxfd = UDEV_MAX(maxfd, signal_pipe[READ_END]);
 906         maxfd = UDEV_MAX(maxfd, inotify_fd);
 907         while (!udev_exit) {
 908                 int fdcount;
 909
 910                 FD_ZERO(&readfds);
 911                 FD_SET(signal_pipe[READ_END], &readfds);
 912                 FD_SET(udev_ctrl_get_fd(udev_ctrl), &readfds);
 913                 FD_SET(udev_monitor_get_fd(kernel_monitor), &readfds);
 914                 if (inotify_fd >= 0)
 915                         FD_SET(inotify_fd, &readfds);
 916                 fdcount = select(maxfd+1, &readfds, NULL, NULL, NULL);
 917                 if (fdcount < 0) {
 918                         if (errno != EINTR)
 919                                 err(udev, "error in select: %m\n");
 920                         continue;
 921                 }
 922
 923                 /* get control message */
 924                 if (FD_ISSET(udev_ctrl_get_fd(udev_ctrl), &readfds))
 925                         handle_ctrl_msg(udev_ctrl);
 926
 927                 /* get kernel uevent */
 928                 if (FD_ISSET(udev_monitor_get_fd(kernel_monitor), &readfds)) {
 929                         struct udev_device *dev;
 930
 931                         dev = udev_monitor_receive_device(kernel_monitor);
 932                         if (dev != NULL) {
 933                                 struct udev_event *event;
 934
 935                                 event = udev_event_new(dev);
 936                                 if (event != NULL)
 937                                         event_queue_insert(event);
 938                                 else
 939                                         udev_device_unref(dev);
 940                         }
 941                 }
 942
 943                 /* received a signal, clear our notification pipe */
 944                 if (FD_ISSET(signal_pipe[READ_END], &readfds)) {
 945                         char buf[256];
 946
 947                         read(signal_pipe[READ_END], &buf, sizeof(buf));
 948                 }
 949
 950                 /* rules directory inotify watch */
 951                 if ((inotify_fd >= 0) && FD_ISSET(inotify_fd, &readfds)) {
 952                         int nbytes;
 953
 954                         /* discard all possible events, we can just reload the config */
 955                         if ((ioctl(inotify_fd, FIONREAD, &nbytes) == 0) && nbytes > 0) {
 956                                 char *buf;
 957
 958                                 reload_config = 1;
 959                                 buf = malloc(nbytes);
 960                                 if (buf == NULL) {
 961                                         err(udev, "error getting buffer for inotify, disable watching\n");
 962                                         close(inotify_fd);
 963                                         inotify_fd = -1;
 964                                 }
 965                                 read(inotify_fd, buf, nbytes);
 966                                 free(buf);
 967                         }
 968                 }
 969
 970                 /* rules changed, set by inotify or a HUP signal */
 971                 if (reload_config) {
 972                         struct udev_rules *rules_new;
 973
 974                         reload_config = 0;
 975                         rules_new = udev_rules_new(udev, resolve_names);
 976                         if (rules_new != NULL) {
 977                                 udev_rules_unref(rules);
 978                                 rules = rules_new;
 979                         }
 980                 }
 981
 982                 if (sigchilds_waiting) {
 983                         sigchilds_waiting = 0;
 984                         reap_sigchilds();
 985                 }
 986
 987                 if (run_exec_q) {
 988                         run_exec_q = 0;
 989                         if (!stop_exec_q)
 990                                 event_queue_manager(udev);
 991                 }
 992         }
 993         cleanup_queue_dir(udev);
 994         rc = 0;
 995 exit:
 996         udev_rules_unref(rules);
 997         if (signal_pipe[READ_END] >= 0)
 998                 close(signal_pipe[READ_END]);
 999         if (signal_pipe[WRITE_END] >= 0)
1000                 close(signal_pipe[WRITE_END]);
1001         udev_ctrl_unref(udev_ctrl);
1002         if (inotify_fd >= 0)
1003                 close(inotify_fd);
1004         udev_monitor_unref(kernel_monitor);
1005         udev_selinux_exit(udev);
1006         udev_unref(udev);
1007         logging_close();
1008         return rc;
1009 }