udev/udevd.c

   1 /*
   2  * Copyright (C) 2004-2008 Kay Sievers <kay.sievers@vrfy.org>
   3  * Copyright (C) 2004 Chris Friesen <chris_friesen@sympatico.ca>
   4  *
   5  * This program is free software: you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation, either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 #include <stddef.h>
  20 #include <signal.h>
  21 #include <unistd.h>
  22 #include <errno.h>
  23 #include <stdio.h>
  24 #include <stdlib.h>
  25 #include <string.h>
  26 #include <ctype.h>
  27 #include <fcntl.h>
  28 #include <time.h>
  29 #include <getopt.h>
  30 #include <dirent.h>
  31 #include <sys/select.h>
  32 #include <sys/poll.h>
  33 #include <sys/wait.h>
  34 #include <sys/stat.h>
  35 #include <sys/ioctl.h>
  36 #ifdef HAVE_INOTIFY
  37 #include <sys/inotify.h>
  38 #endif
  39
  40 #include "udev.h"
  41
  42 #define UDEVD_PRIORITY                  -4
  43 #define UDEV_PRIORITY                   -2
  44
  45 /* maximum limit of forked childs */
  46 #define UDEVD_MAX_CHILDS                256
  47
  48 static int debug;
  49
  50 static void log_fn(struct udev *udev, int priority,
  51                    const char *file, int line, const char *fn,
  52                    const char *format, va_list args)
  53 {
  54         if (debug) {
  55                 fprintf(stderr, "[%d] %s: ", (int) getpid(), fn);
  56                 vfprintf(stderr, format, args);
  57         } else {
  58                 vsyslog(priority, format, args);
  59         }
  60 }
  61
  62 static void reap_sigchilds(void);
  63
  64 static int debug_trace;
  65 static struct udev_rules *rules;
  66 static struct udev_ctrl *udev_ctrl;
  67 static struct udev_monitor *kernel_monitor;
  68 static int inotify_fd = -1;
  69 static volatile int sigchilds_waiting;
  70 static volatile int udev_exit;
  71 static volatile int reload_config;
  72 static volatile int signal_received;
  73 static int run_exec_q;
  74 static int stop_exec_q;
  75 static int max_childs;
  76 static int childs;
  77 static struct udev_list_node event_list;
  78
  79 enum event_state {
  80         EVENT_QUEUED,
  81         EVENT_FINISHED,
  82         EVENT_FAILED,
  83 };
  84
  85 static struct udev_event *node_to_event(struct udev_list_node *node)
  86 {
  87         char *event;
  88
  89         event = (char *)node;
  90         event -= offsetof(struct udev_event, node);
  91         return (struct udev_event *)event;
  92 }
  93
  94 static void export_event_state(struct udev_event *event, enum event_state state)
  95 {
  96         char filename[UTIL_PATH_SIZE];
  97         char filename_failed[UTIL_PATH_SIZE];
  98         size_t start;
  99
 100         /* location of queue file */
 101         snprintf(filename, sizeof(filename), "%s/.udev/queue/%llu",
 102                  udev_get_dev_path(event->udev), udev_device_get_seqnum(event->dev));
 103
 104         /* location of failed file */
 105         util_strlcpy(filename_failed, udev_get_dev_path(event->udev), sizeof(filename_failed));
 106         util_strlcat(filename_failed, "/", sizeof(filename_failed));
 107         start = util_strlcat(filename_failed, ".udev/failed/", sizeof(filename_failed));
 108         util_strlcat(filename_failed, udev_device_get_devpath(event->dev), sizeof(filename_failed));
 109         util_path_encode(&filename_failed[start], sizeof(filename_failed) - start);
 110
 111         switch (state) {
 112         case EVENT_QUEUED:
 113                 if(unlink(filename_failed) == 0)
 114                         util_delete_path(event->udev, filename_failed);
 115                 util_create_path(event->udev, filename);
 116                 udev_selinux_setfscreatecon(event->udev, filename, S_IFLNK);
 117                 symlink(udev_device_get_devpath(event->dev), filename);
 118                 udev_selinux_resetfscreatecon(event->udev);
 119                 break;
 120         case EVENT_FINISHED:
 121                 if (udev_device_get_devpath_old(event->dev) != NULL) {
 122                         /* "move" event - rename failed file to current name, do not delete failed */
 123                         char filename_failed_old[UTIL_PATH_SIZE];
 124
 125                         util_strlcpy(filename_failed_old, udev_get_dev_path(event->udev), sizeof(filename_failed_old));
 126                         util_strlcat(filename_failed_old, "/", sizeof(filename_failed_old));
 127                         start = util_strlcat(filename_failed_old, ".udev/failed/", sizeof(filename_failed_old));
 128                         util_strlcat(filename_failed_old, udev_device_get_devpath_old(event->dev), sizeof(filename_failed_old));
 129                         util_path_encode(&filename_failed_old[start], sizeof(filename) - start);
 130
 131                         if (rename(filename_failed_old, filename_failed) == 0)
 132                                 info(event->udev, "renamed devpath, moved failed state of '%s' to %s'\n",
 133                                      udev_device_get_devpath_old(event->dev), udev_device_get_devpath(event->dev));
 134                 } else {
 135                         if (unlink(filename_failed) == 0)
 136                                 util_delete_path(event->udev, filename_failed);
 137                 }
 138
 139                 unlink(filename);
 140
 141                 /* clean up possibly empty queue directory */
 142                 if (udev_list_is_empty(&event_list))
 143                         util_delete_path(event->udev, filename);
 144                 break;
 145         case EVENT_FAILED:
 146                 /* move failed event to the failed directory */
 147                 util_create_path(event->udev, filename_failed);
 148                 rename(filename, filename_failed);
 149
 150                 /* clean up possibly empty queue directory */
 151                 if (udev_list_is_empty(&event_list))
 152                         util_delete_path(event->udev, filename);
 153                 break;
 154         }
 155
 156         return;
 157 }
 158
 159 static void event_queue_delete(struct udev_event *event)
 160 {
 161         udev_list_node_remove(&event->node);
 162
 163         /* mark as failed, if "add" event returns non-zero */
 164         if (event->exitstatus && strcmp(udev_device_get_action(event->dev), "add") == 0)
 165                 export_event_state(event, EVENT_FAILED);
 166         else
 167                 export_event_state(event, EVENT_FINISHED);
 168
 169         udev_device_unref(event->dev);
 170         udev_event_unref(event);
 171 }
 172
 173 static void asmlinkage event_sig_handler(int signum)
 174 {
 175         if (signum == SIGALRM)
 176                 exit(1);
 177 }
 178
 179 static void event_fork(struct udev_event *event)
 180 {
 181         pid_t pid;
 182         struct sigaction act;
 183         int err;
 184
 185         if (debug_trace) {
 186                 event->trace = 1;
 187                 fprintf(stderr, "fork %s (%llu)\n",
 188                        udev_device_get_syspath(event->dev),
 189                        udev_device_get_seqnum(event->dev));
 190         }
 191
 192         pid = fork();
 193         switch (pid) {
 194         case 0:
 195                 /* child */
 196                 udev_monitor_unref(kernel_monitor);
 197                 udev_ctrl_unref(udev_ctrl);
 198                 if (inotify_fd >= 0)
 199                         close(inotify_fd);
 200                 logging_close();
 201                 logging_init("udevd-event");
 202                 setpriority(PRIO_PROCESS, 0, UDEV_PRIORITY);
 203
 204                 /* set signal handlers */
 205                 memset(&act, 0x00, sizeof(act));
 206                 act.sa_handler = (void (*)(int)) event_sig_handler;
 207                 sigemptyset (&act.sa_mask);
 208                 act.sa_flags = 0;
 209                 sigaction(SIGALRM, &act, NULL);
 210
 211                 /* reset to default */
 212                 act.sa_handler = SIG_DFL;
 213                 sigaction(SIGINT, &act, NULL);
 214                 sigaction(SIGTERM, &act, NULL);
 215                 sigaction(SIGCHLD, &act, NULL);
 216                 sigaction(SIGHUP, &act, NULL);
 217
 218                 /* set timeout to prevent hanging processes */
 219                 alarm(UDEV_EVENT_TIMEOUT);
 220
 221                 /* apply rules, create node, symlinks */
 222                 err = udev_event_execute_rules(event, rules);
 223
 224                 /* rules may change/disable the timeout */
 225                 if (udev_device_get_event_timeout(event->dev) >= 0)
 226                         alarm(udev_device_get_event_timeout(event->dev));
 227
 228                 /* execute RUN= */
 229                 if (err == 0 && !event->ignore_device && udev_get_run(event->udev))
 230                         udev_event_execute_run(event);
 231
 232                 info(event->udev, "seq %llu exit with %i\n", udev_device_get_seqnum(event->dev), err);
 233                 logging_close();
 234                 if (err != 0)
 235                         exit(1);
 236                 exit(0);
 237         case -1:
 238                 err(event->udev, "fork of child failed: %m\n");
 239                 event_queue_delete(event);
 240                 break;
 241         default:
 242                 /* get SIGCHLD in main loop */
 243                 info(event->udev, "seq %llu forked, pid [%d], '%s' '%s', %ld seconds old\n",
 244                      udev_device_get_seqnum(event->dev),
 245                      pid,
 246                      udev_device_get_action(event->dev),
 247                      udev_device_get_subsystem(event->dev),
 248                      time(NULL) - event->queue_time);
 249                 event->pid = pid;
 250                 childs++;
 251         }
 252 }
 253
 254 static void event_queue_insert(struct udev_event *event)
 255 {
 256         char filename[UTIL_PATH_SIZE];
 257         int fd;
 258
 259         event->queue_time = time(NULL);
 260
 261         export_event_state(event, EVENT_QUEUED);
 262         info(event->udev, "seq %llu queued, '%s' '%s'\n", udev_device_get_seqnum(event->dev),
 263              udev_device_get_action(event->dev), udev_device_get_subsystem(event->dev));
 264
 265         util_strlcpy(filename, udev_get_dev_path(event->udev), sizeof(filename));
 266         util_strlcat(filename, "/.udev/uevent_seqnum", sizeof(filename));
 267         fd = open(filename, O_WRONLY|O_TRUNC|O_CREAT, 0644);
 268         if (fd >= 0) {
 269                 char str[32];
 270                 int len;
 271
 272                 len = sprintf(str, "%llu\n", udev_device_get_seqnum(event->dev));
 273                 write(fd, str, len);
 274                 close(fd);
 275         }
 276
 277
 278         udev_list_node_append(&event->node, &event_list);
 279         run_exec_q = 1;
 280
 281         /* run all events with a timeout set immediately */
 282         if (udev_device_get_timeout(event->dev) > 0) {
 283                 event_fork(event);
 284                 return;
 285         }
 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 = 0;
 314
 315         while (running[i] != '\0' && running[i] == waiting[i])
 316                 i++;
 317
 318         /* identical device event found */
 319         if (running[i] == '\0' && waiting[i] == '\0')
 320                 return 1;
 321
 322         /* parent device event found */
 323         if (running[i] == '\0' && waiting[i] == '/')
 324                 return 2;
 325
 326         /* child device event found */
 327         if (running[i] == '/' && waiting[i] == '\0')
 328                 return 3;
 329
 330         /* no matching event */
 331         return 0;
 332 }
 333
 334 /* lookup event for identical, parent, child, or physical device */
 335 static int devpath_busy(struct udev_event *event)
 336 {
 337         struct udev_list_node *loop;
 338
 339         if (event->delaying_seqnum > 0) {
 340         }
 341         /* check if queue contains events we depend on */
 342         udev_list_node_foreach(loop, &event_list) {
 343                 struct udev_event *loop_event = node_to_event(loop);
 344
 345                 /* we already found a later event, earlier can not block us, no need to check again */
 346                 if (udev_device_get_seqnum(loop_event->dev) < event->delaying_seqnum)
 347                         continue;
 348
 349                 /* event we checked earlier still exists, no need to check again */
 350                 if (udev_device_get_seqnum(loop_event->dev) == event->delaying_seqnum)
 351                         return 2;
 352
 353                 /* found ourself, no later event can block us */
 354                 if (udev_device_get_seqnum(loop_event->dev) >= udev_device_get_seqnum(event->dev))
 355                         break;
 356
 357                 /* check our old name */
 358                 if (udev_device_get_devpath_old(event->dev) != NULL)
 359                         if (strcmp(udev_device_get_devpath(loop_event->dev), udev_device_get_devpath_old(event->dev)) == 0) {
 360                                 event->delaying_seqnum = udev_device_get_seqnum(loop_event->dev);
 361                                 return 3;
 362                         }
 363
 364                 /* check identical, parent, or child device event */
 365                 if (compare_devpath(udev_device_get_devpath(loop_event->dev), udev_device_get_devpath(event->dev)) != 0) {
 366                         dbg(event->udev, "%llu, device event still pending %llu (%s)\n",
 367                             udev_device_get_seqnum(event->dev),
 368                             udev_device_get_seqnum(loop_event->dev),
 369                             udev_device_get_devpath(loop_event->dev));
 370                         event->delaying_seqnum = udev_device_get_seqnum(loop_event->dev);
 371                         return 4;
 372                 }
 373
 374                 /* check for our major:minor number */
 375                 if (major(udev_device_get_devnum(event->dev)) > 0 &&
 376                     udev_device_get_devnum(loop_event->dev) == udev_device_get_devnum(event->dev) &&
 377                     strcmp(udev_device_get_subsystem(event->dev), udev_device_get_subsystem(loop_event->dev)) == 0) {
 378                         dbg(event->udev, "%llu, device event still pending %llu (%d:%d)\n",
 379                             udev_device_get_seqnum(event->dev),
 380                             udev_device_get_seqnum(loop_event->dev),
 381                             major(udev_device_get_devnum(loop_event->dev)), minor(udev_device_get_devnum(loop_event->dev)));
 382                         event->delaying_seqnum = udev_device_get_seqnum(loop_event->dev);
 383                         return 5;
 384                 }
 385
 386                 /* check physical device event (special case of parent) */
 387                 if (udev_device_get_physdevpath(event->dev) != NULL &&
 388                     strcmp(udev_device_get_action(event->dev), "add") == 0)
 389                         if (compare_devpath(udev_device_get_devpath(loop_event->dev),
 390                                             udev_device_get_physdevpath(event->dev)) != 0) {
 391                                 dbg(event->udev, "%llu, physical device event still pending %llu (%s)\n",
 392                                     udev_device_get_seqnum(event->dev),
 393                                     udev_device_get_seqnum(loop_event->dev),
 394                                     udev_device_get_devpath(loop_event->dev));
 395                                 event->delaying_seqnum = udev_device_get_seqnum(loop_event->dev);
 396                                 return 6;
 397                         }
 398         }
 399         return 0;
 400 }
 401
 402 /* serializes events for the identical and parent and child devices */
 403 static void event_queue_manager(struct udev *udev)
 404 {
 405         struct udev_list_node *loop;
 406         struct udev_list_node *tmp;
 407
 408 start_over:
 409         if (udev_list_is_empty(&event_list)) {
 410                 if (childs > 0) {
 411                         err(udev, "event list empty, but childs count is %i", childs);
 412                         childs = 0;
 413                 }
 414                 return;
 415         }
 416
 417         udev_list_node_foreach_safe(loop, tmp, &event_list) {
 418                 struct udev_event *loop_event = node_to_event(loop);
 419
 420                 if (childs >= max_childs) {
 421                         info(udev, "maximum number (%i) of childs reached\n", childs);
 422                         break;
 423                 }
 424
 425                 if (loop_event->pid != 0)
 426                         continue;
 427
 428                 /* do not start event if parent or child event is still running */
 429                 if (devpath_busy(loop_event) != 0) {
 430                         dbg(udev, "delay seq %llu (%s)\n",
 431                             udev_device_get_seqnum(loop_event->dev),
 432                             udev_device_get_devpath(loop_event->dev));
 433                         continue;
 434                 }
 435
 436                 event_fork(loop_event);
 437                 dbg(udev, "moved seq %llu to running list\n", udev_device_get_seqnum(loop_event->dev));
 438
 439                 /* retry if events finished in the meantime */
 440                 if (sigchilds_waiting) {
 441                         sigchilds_waiting = 0;
 442                         reap_sigchilds();
 443                         goto start_over;
 444                 }
 445         }
 446 }
 447
 448 /* receive the udevd message from userspace */
 449 static void handle_ctrl_msg(struct udev_ctrl *uctrl)
 450 {
 451         struct udev *udev = udev_ctrl_get_udev(uctrl);
 452         struct udev_ctrl_msg *ctrl_msg;
 453         const char *str;
 454         int i;
 455
 456         ctrl_msg = udev_ctrl_receive_msg(uctrl);
 457         if (ctrl_msg == NULL)
 458                 return;
 459
 460         i = udev_ctrl_get_set_log_level(ctrl_msg);
 461         if (i >= 0) {
 462                 info(udev, "udevd message (SET_LOG_PRIORITY) received, log_priority=%i\n", i);
 463                 udev_set_log_priority(udev, i);
 464         }
 465
 466         if (udev_ctrl_get_stop_exec_queue(ctrl_msg) > 0) {
 467                 info(udev, "udevd message (STOP_EXEC_QUEUE) received\n");
 468                 stop_exec_q = 1;
 469         }
 470
 471         if (udev_ctrl_get_start_exec_queue(ctrl_msg) > 0) {
 472                 info(udev, "udevd message (START_EXEC_QUEUE) received\n");
 473                 stop_exec_q = 0;
 474                 event_queue_manager(udev);
 475         }
 476
 477         if (udev_ctrl_get_reload_rules(ctrl_msg) > 0) {
 478                 info(udev, "udevd message (RELOAD_RULES) received\n");
 479                 reload_config = 1;
 480         }
 481
 482         str = udev_ctrl_get_set_env(ctrl_msg);
 483         if (str != NULL) {
 484                 char *key;
 485
 486                 key = strdup(str);
 487                 if (key != NULL) {
 488                         char *val;
 489
 490                         val = strchr(key, '=');
 491                         if (val != NULL) {
 492                                 val[0] = '\0';
 493                                 val = &val[1];
 494                                 if (val[0] == '\0') {
 495                                         info(udev, "udevd message (ENV) received, unset '%s'\n", key);
 496                                         udev_add_property(udev, key, NULL);
 497                                 } else {
 498                                         info(udev, "udevd message (ENV) received, set '%s=%s'\n", key, val);
 499                                         udev_add_property(udev, key, val);
 500                                 }
 501                         } else {
 502                                 err(udev, "wrong key format '%s'\n", key);
 503                         }
 504                         free(key);
 505                 }
 506         }
 507
 508         i = udev_ctrl_get_set_max_childs(ctrl_msg);
 509         if (i >= 0) {
 510                 info(udev, "udevd message (SET_MAX_CHILDS) received, max_childs=%i\n", i);
 511                 max_childs = i;
 512         }
 513         udev_ctrl_msg_unref(ctrl_msg);
 514 }
 515
 516 static void asmlinkage sig_handler(int signum)
 517 {
 518         switch (signum) {
 519                 case SIGINT:
 520                 case SIGTERM:
 521                         udev_exit = 1;
 522                         break;
 523                 case SIGCHLD:
 524                         /* set flag, then write to pipe if needed */
 525                         sigchilds_waiting = 1;
 526                         break;
 527                 case SIGHUP:
 528                         reload_config = 1;
 529                         break;
 530         }
 531
 532         signal_received = 1;
 533 }
 534
 535 static void udev_done(int pid, int exitstatus)
 536 {
 537         struct udev_list_node *loop;
 538
 539         /* find event associated with pid and delete it */
 540         udev_list_node_foreach(loop, &event_list) {
 541                 struct udev_event *loop_event = node_to_event(loop);
 542
 543                 if (loop_event->pid == pid) {
 544                         info(loop_event->udev, "seq %llu cleanup, pid [%d], status %i, %ld seconds old\n",
 545                              udev_device_get_seqnum(loop_event->dev), loop_event->pid,
 546                              exitstatus, time(NULL) - loop_event->queue_time);
 547                         loop_event->exitstatus = exitstatus;
 548                         if (debug_trace)
 549                                 fprintf(stderr, "exit %s (%llu)\n",
 550                                        udev_device_get_syspath(loop_event->dev),
 551                                        udev_device_get_seqnum(loop_event->dev));
 552                         event_queue_delete(loop_event);
 553                         childs--;
 554
 555                         /* there may be dependent events waiting */
 556                         run_exec_q = 1;
 557                         return;
 558                 }
 559         }
 560 }
 561
 562 static void reap_sigchilds(void)
 563 {
 564         pid_t pid;
 565         int status;
 566
 567         while (1) {
 568                 pid = waitpid(-1, &status, WNOHANG);
 569                 if (pid <= 0)
 570                         break;
 571                 if (WIFEXITED(status))
 572                         status = WEXITSTATUS(status);
 573                 else if (WIFSIGNALED(status))
 574                         status = WTERMSIG(status) + 128;
 575                 else
 576                         status = 0;
 577                 udev_done(pid, status);
 578         }
 579 }
 580
 581 static void cleanup_queue_dir(struct udev *udev)
 582 {
 583         char dirname[UTIL_PATH_SIZE];
 584         char filename[UTIL_PATH_SIZE];
 585         DIR *dir;
 586
 587         util_strlcpy(filename, udev_get_dev_path(udev), sizeof(filename));
 588         util_strlcat(filename, "/.udev/uevent_seqnum", sizeof(filename));
 589         unlink(filename);
 590
 591         util_strlcpy(dirname, udev_get_dev_path(udev), sizeof(dirname));
 592         util_strlcat(dirname, "/.udev/queue", sizeof(dirname));
 593         dir = opendir(dirname);
 594         if (dir != NULL) {
 595                 while (1) {
 596                         struct dirent *dent;
 597
 598                         dent = readdir(dir);
 599                         if (dent == NULL || dent->d_name[0] == '\0')
 600                                 break;
 601                         if (dent->d_name[0] == '.')
 602                                 continue;
 603                         util_strlcpy(filename, dirname, sizeof(filename));
 604                         util_strlcat(filename, "/", sizeof(filename));
 605                         util_strlcat(filename, dent->d_name, sizeof(filename));
 606                         unlink(filename);
 607                 }
 608                 closedir(dir);
 609                 rmdir(dirname);
 610         }
 611 }
 612
 613 static void export_initial_seqnum(struct udev *udev)
 614 {
 615         char filename[UTIL_PATH_SIZE];
 616         int fd;
 617         char seqnum[32];
 618         ssize_t len = 0;
 619
 620         util_strlcpy(filename, udev_get_sys_path(udev), sizeof(filename));
 621         util_strlcat(filename, "/kernel/uevent_seqnum", sizeof(filename));
 622         fd = open(filename, O_RDONLY);
 623         if (fd >= 0) {
 624                 len = read(fd, seqnum, sizeof(seqnum)-1);
 625                 close(fd);
 626         }
 627         if (len <= 0) {
 628                 strcpy(seqnum, "0\n");
 629                 len = 3;
 630         }
 631         util_strlcpy(filename, udev_get_dev_path(udev), sizeof(filename));
 632         util_strlcat(filename, "/.udev/uevent_seqnum", sizeof(filename));
 633         util_create_path(udev, filename);
 634         fd = open(filename, O_WRONLY|O_TRUNC|O_CREAT, 0644);
 635         if (fd >= 0) {
 636                 write(fd, seqnum, len);
 637                 close(fd);
 638         }
 639 }
 640
 641 int main(int argc, char *argv[])
 642 {
 643         struct udev *udev;
 644         int fd;
 645         struct sigaction act;
 646         const char *value;
 647         int daemonize = 0;
 648         int resolve_names = 1;
 649         static const struct option options[] = {
 650                 { "daemon", no_argument, NULL, 'd' },
 651                 { "debug-trace", no_argument, NULL, 't' },
 652                 { "debug", no_argument, NULL, 'D' },
 653                 { "help", no_argument, NULL, 'h' },
 654                 { "version", no_argument, NULL, 'V' },
 655                 { "resolve-names", required_argument, NULL, 'N' },
 656                 {}
 657         };
 658         int rc = 1;
 659
 660         udev = udev_new();
 661         if (udev == NULL)
 662                 goto exit;
 663
 664         logging_init("udevd");
 665         udev_set_log_fn(udev, log_fn);
 666         info(udev, "version %s\n", VERSION);
 667         udev_selinux_init(udev);
 668
 669         while (1) {
 670                 int option;
 671
 672                 option = getopt_long(argc, argv, "dDthV", options, NULL);
 673                 if (option == -1)
 674                         break;
 675
 676                 switch (option) {
 677                 case 'd':
 678                         daemonize = 1;
 679                         break;
 680                 case 't':
 681                         debug_trace = 1;
 682                         break;
 683                 case 'D':
 684                         debug = 1;
 685                         if (udev_get_log_priority(udev) < LOG_INFO)
 686                                 udev_set_log_priority(udev, LOG_INFO);
 687                         break;
 688                 case 'N':
 689                         if (strcmp (optarg, "early") == 0) {
 690                                 resolve_names = 1;
 691                         } else if (strcmp (optarg, "late") == 0) {
 692                                 resolve_names = 0;
 693                         } else if (strcmp (optarg, "never") == 0) {
 694                                 resolve_names = -1;
 695                         } else {
 696                                 fprintf(stderr, "resolve-names must be early, late or never\n");
 697                                 err(udev, "resolve-names must be early, late or never\n");
 698                                 goto exit;
 699                         }
 700                         break;
 701                 case 'h':
 702                         printf("Usage: udevd [--help] [--daemon] [--debug-trace] [--debug] "
 703                                "[--resolve-names=early|late|never] [--version]\n");
 704                         goto exit;
 705                 case 'V':
 706                         printf("%s\n", VERSION);
 707                         goto exit;
 708                 default:
 709                         goto exit;
 710                 }
 711         }
 712
 713         if (getuid() != 0) {
 714                 fprintf(stderr, "root privileges required\n");
 715                 err(udev, "root privileges required\n");
 716                 goto exit;
 717         }
 718
 719         /* make sure std{in,out,err} fd's are in a sane state */
 720         fd = open("/dev/null", O_RDWR);
 721         if (fd < 0) {
 722                 fprintf(stderr, "cannot open /dev/null\n");
 723                 err(udev, "cannot open /dev/null\n");
 724         }
 725         if (write(STDOUT_FILENO, 0, 0) < 0)
 726                 dup2(fd, STDOUT_FILENO);
 727         if (write(STDERR_FILENO, 0, 0) < 0)
 728                 dup2(fd, STDERR_FILENO);
 729
 730         /* init control socket, bind() ensures, that only one udevd instance is running */
 731         udev_ctrl = udev_ctrl_new_from_socket(udev, UDEV_CTRL_SOCK_PATH);
 732         if (udev_ctrl == NULL) {
 733                 fprintf(stderr, "error initializing control socket");
 734                 err(udev, "error initializing udevd socket");
 735                 rc = 1;
 736                 goto exit;
 737         }
 738
 739         if (udev_ctrl_enable_receiving(udev_ctrl) < 0) {
 740                 fprintf(stderr, "error binding control socket, seems udevd is already running\n");
 741                 err(udev, "error binding control socket, seems udevd is already running\n");
 742                 rc = 1;
 743                 goto exit;
 744         }
 745
 746         kernel_monitor = udev_monitor_new_from_netlink(udev);
 747         if (kernel_monitor == NULL || udev_monitor_enable_receiving(kernel_monitor) < 0) {
 748                 fprintf(stderr, "error initializing netlink socket\n");
 749                 err(udev, "error initializing netlink socket\n");
 750                 rc = 3;
 751                 goto exit;
 752         }
 753         udev_monitor_set_receive_buffer_size(kernel_monitor, 128*1024*1024);
 754
 755         rules = udev_rules_new(udev, resolve_names);
 756         if (rules == NULL) {
 757                 err(udev, "error reading rules\n");
 758                 goto exit;
 759         }
 760         udev_list_init(&event_list);
 761         cleanup_queue_dir(udev);
 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 && !debug_trace) {
 785                 dup2(fd, STDIN_FILENO);
 786                 dup2(fd, STDOUT_FILENO);
 787                 dup2(fd, STDERR_FILENO);
 788         }
 789         if (fd > STDERR_FILENO)
 790                 close(fd);
 791
 792         /* set scheduling priority for the daemon */
 793         setpriority(PRIO_PROCESS, 0, UDEVD_PRIORITY);
 794
 795         chdir("/");
 796         umask(022);
 797         setsid();
 798
 799         /* OOM_DISABLE == -17 */
 800         fd = open("/proc/self/oom_adj", O_RDWR);
 801         if (fd < 0)
 802                 err(udev, "error disabling OOM: %m\n");
 803         else {
 804                 write(fd, "-17", 3);
 805                 close(fd);
 806         }
 807
 808         fd = open("/dev/kmsg", O_WRONLY);
 809         if (fd > 0) {
 810                 const char *ver_str = "<6>udev: starting version " VERSION "\n";
 811                 char path[UTIL_PATH_SIZE];
 812                 struct stat statbuf;
 813
 814                 write(fd, ver_str, strlen(ver_str));
 815                 util_strlcpy(path, udev_get_sys_path(udev), sizeof(path));
 816                 util_strlcat(path, "/class/mem/null", sizeof(path));
 817                 if (lstat(path, &statbuf) == 0) {
 818                         if (S_ISDIR(statbuf.st_mode)) {
 819                                 const char *depr_str =
 820                                         "<6>udev: deprecated sysfs layout; update the kernel or "
 821                                         "disable CONFIG_SYSFS_DEPRECATED; some udev features will "
 822                                         "not work correctly\n";
 823
 824                                 write(fd, depr_str, strlen(depr_str));
 825                         }
 826                 }
 827                 close(fd);
 828         }
 829
 830         /* set signal handlers */
 831         memset(&act, 0x00, sizeof(struct sigaction));
 832         act.sa_handler = (void (*)(int)) sig_handler;
 833         sigemptyset(&act.sa_mask);
 834         act.sa_flags = SA_RESTART;
 835         sigaction(SIGINT, &act, NULL);
 836         sigaction(SIGTERM, &act, NULL);
 837         sigaction(SIGCHLD, &act, NULL);
 838         sigaction(SIGHUP, &act, NULL);
 839
 840         /* watch rules directory */
 841         inotify_fd = inotify_init();
 842         if (inotify_fd >= 0) {
 843                 if (udev_get_rules_path(udev) != NULL) {
 844                         inotify_add_watch(inotify_fd, udev_get_rules_path(udev),
 845                                           IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
 846                 } else {
 847                         char filename[UTIL_PATH_SIZE];
 848
 849                         inotify_add_watch(inotify_fd, UDEV_PREFIX "/lib/udev/rules.d",
 850                                           IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
 851                         inotify_add_watch(inotify_fd, SYSCONFDIR "/udev/rules.d",
 852                                           IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
 853
 854                         /* watch dynamic rules directory */
 855                         util_strlcpy(filename, udev_get_dev_path(udev), sizeof(filename));
 856                         util_strlcat(filename, "/.udev/rules.d", sizeof(filename));
 857                         inotify_add_watch(inotify_fd, filename,
 858                                           IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
 859                 }
 860         } else if (errno == ENOSYS)
 861                 info(udev, "unable to use inotify, udevd will not monitor rule files changes\n");
 862         else
 863                 err(udev, "inotify_init failed: %m\n");
 864
 865         /* in trace mode run one event after the other */
 866         if (debug_trace) {
 867                 max_childs = 1;
 868         } else {
 869                 int memsize = mem_size_mb();
 870                 if (memsize > 0)
 871                         max_childs = 128 + (memsize / 4);
 872                 else
 873                         max_childs = UDEVD_MAX_CHILDS;
 874         }
 875         /* possibly overwrite maximum limit of executed events */
 876         value = getenv("UDEVD_MAX_CHILDS");
 877         if (value)
 878                 max_childs = strtoul(value, NULL, 10);
 879         info(udev, "initialize max_childs to %u\n", max_childs);
 880
 881         while (!udev_exit) {
 882                 sigset_t blocked_mask, orig_mask;
 883                 struct pollfd pfd[4];
 884                 struct pollfd *ctrl_poll, *monitor_poll, *inotify_poll = NULL;
 885                 int nfds = 0;
 886                 int fdcount;
 887
 888                 sigfillset(&blocked_mask);
 889                 sigprocmask(SIG_SETMASK, &blocked_mask, &orig_mask);
 890                 if (signal_received) {
 891                         sigprocmask(SIG_SETMASK, &orig_mask, NULL);
 892                         goto handle_signals;
 893                 }
 894
 895                 ctrl_poll = &pfd[nfds++];
 896                 ctrl_poll->fd = udev_ctrl_get_fd(udev_ctrl);
 897                 ctrl_poll->events = POLLIN;
 898
 899                 monitor_poll = &pfd[nfds++];
 900                 monitor_poll->fd = udev_monitor_get_fd(kernel_monitor);
 901                 monitor_poll->events = POLLIN;
 902
 903                 if (inotify_fd >= 0) {
 904                         inotify_poll = &pfd[nfds++];
 905                         inotify_poll->fd = inotify_fd;
 906                         inotify_poll->events = POLLIN;
 907                 }
 908
 909                 fdcount = ppoll(pfd, nfds, NULL, &orig_mask);
 910                 sigprocmask(SIG_SETMASK, &orig_mask, NULL);
 911                 if (fdcount < 0) {
 912                         if (errno == EINTR)
 913                                 goto handle_signals;
 914                         err(udev, "error in select: %m\n");
 915                         continue;
 916                 }
 917
 918                 /* get control message */
 919                 if (ctrl_poll->revents & POLLIN)
 920                         handle_ctrl_msg(udev_ctrl);
 921
 922                 /* get kernel uevent */
 923                 if (monitor_poll->revents & POLLIN) {
 924                         struct udev_device *dev;
 925
 926                         dev = udev_monitor_receive_device(kernel_monitor);
 927                         if (dev != NULL) {
 928                                 struct udev_event *event;
 929
 930                                 event = udev_event_new(dev);
 931                                 if (event != NULL)
 932                                         event_queue_insert(event);
 933                                 else
 934                                         udev_device_unref(dev);
 935                         }
 936                 }
 937
 938                 /* rules directory inotify watch */
 939                 if (inotify_poll && (inotify_poll->revents & POLLIN)) {
 940                         int nbytes;
 941
 942                         /* discard all possible events, we can just reload the config */
 943                         if ((ioctl(inotify_fd, FIONREAD, &nbytes) == 0) && nbytes > 0) {
 944                                 char *buf;
 945
 946                                 reload_config = 1;
 947                                 buf = malloc(nbytes);
 948                                 if (buf == NULL) {
 949                                         err(udev, "error getting buffer for inotify, disable watching\n");
 950                                         close(inotify_fd);
 951                                         inotify_fd = -1;
 952                                 }
 953                                 read(inotify_fd, buf, nbytes);
 954                                 free(buf);
 955                         }
 956                 }
 957
 958 handle_signals:
 959                 signal_received = 0;
 960
 961                 /* rules changed, set by inotify or a HUP signal */
 962                 if (reload_config) {
 963                         struct udev_rules *rules_new;
 964
 965                         reload_config = 0;
 966                         rules_new = udev_rules_new(udev, resolve_names);
 967                         if (rules_new != NULL) {
 968                                 udev_rules_unref(rules);
 969                                 rules = rules_new;
 970                         }
 971                 }
 972
 973                 if (sigchilds_waiting) {
 974                         sigchilds_waiting = 0;
 975                         reap_sigchilds();
 976                 }
 977
 978                 if (run_exec_q) {
 979                         run_exec_q = 0;
 980                         if (!stop_exec_q)
 981                                 event_queue_manager(udev);
 982                 }
 983         }
 984         cleanup_queue_dir(udev);
 985         rc = 0;
 986 exit:
 987         udev_rules_unref(rules);
 988         udev_ctrl_unref(udev_ctrl);
 989         if (inotify_fd >= 0)
 990                 close(inotify_fd);
 991         udev_monitor_unref(kernel_monitor);
 992         udev_selinux_exit(udev);
 993         udev_unref(udev);
 994         logging_close();
 995         return rc;
 996 }