udev/udevd.c

   1 /*
   2  * Copyright (C) 2004-2008 Kay Sievers <kay.sievers@vrfy.org>
   3  * Copyright (C) 2004 Chris Friesen <chris_friesen@sympatico.ca>
   4  *
   5  * This program is free software: you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation, either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 #include <stddef.h>
  20 #include <signal.h>
  21 #include <unistd.h>
  22 #include <errno.h>
  23 #include <stdio.h>
  24 #include <stdlib.h>
  25 #include <string.h>
  26 #include <ctype.h>
  27 #include <fcntl.h>
  28 #include <time.h>
  29 #include <getopt.h>
  30 #include <sys/select.h>
  31 #include <sys/wait.h>
  32 #include <sys/stat.h>
  33 #include <sys/ioctl.h>
  34 #ifdef HAVE_INOTIFY
  35 #include <sys/inotify.h>
  36 #endif
  37
  38 #include "udev.h"
  39
  40 #define UDEVD_PRIORITY                  -4
  41 #define UDEV_PRIORITY                   -2
  42
  43 /* maximum limit of forked childs */
  44 #define UDEVD_MAX_CHILDS                256
  45
  46 static int debug;
  47
  48 static void log_fn(struct udev *udev, int priority,
  49                    const char *file, int line, const char *fn,
  50                    const char *format, va_list args)
  51 {
  52         if (debug) {
  53                 fprintf(stderr, "[%d] %s: ", (int) getpid(), fn);
  54                 vfprintf(stderr, format, args);
  55         } else {
  56                 vsyslog(priority, format, args);
  57         }
  58 }
  59
  60 static int debug_trace;
  61 static struct udev_rules *rules;
  62 static struct udev_ctrl *udev_ctrl;
  63 static struct udev_monitor *kernel_monitor;
  64 static int inotify_fd = -1;
  65
  66 static int signal_pipe[2] = {-1, -1};
  67 static volatile int sigchilds_waiting;
  68 static volatile int udev_exit;
  69 static volatile int reload_config;
  70 static int run_exec_q;
  71 static int stop_exec_q;
  72 static int max_childs;
  73
  74 static struct udev_list_node exec_list;
  75 static struct udev_list_node running_list;
  76
  77 enum event_state {
  78         EVENT_QUEUED,
  79         EVENT_FINISHED,
  80         EVENT_FAILED,
  81 };
  82
  83 static struct udev_event *node_to_event(struct udev_list_node *node)
  84 {
  85         char *event;
  86
  87         event = (char *)node;
  88         event -= offsetof(struct udev_event, node);
  89         return (struct udev_event *)event;
  90 }
  91
  92 static void export_event_state(struct udev_event *event, enum event_state state)
  93 {
  94         char filename[UTIL_PATH_SIZE];
  95         char filename_failed[UTIL_PATH_SIZE];
  96         size_t start;
  97
  98         /* location of queue file */
  99         snprintf(filename, sizeof(filename), "%s/.udev/queue/%llu",
 100                  udev_get_dev_path(event->udev), udev_device_get_seqnum(event->dev));
 101
 102         /* location of failed file */
 103         util_strlcpy(filename_failed, udev_get_dev_path(event->udev), sizeof(filename_failed));
 104         util_strlcat(filename_failed, "/", sizeof(filename_failed));
 105         start = util_strlcat(filename_failed, ".udev/failed/", sizeof(filename_failed));
 106         util_strlcat(filename_failed, udev_device_get_devpath(event->dev), sizeof(filename_failed));
 107         util_path_encode(&filename_failed[start], sizeof(filename_failed) - start);
 108
 109         switch (state) {
 110         case EVENT_QUEUED:
 111                 if(unlink(filename_failed) == 0)
 112                         util_delete_path(event->udev, filename_failed);
 113                 util_create_path(event->udev, filename);
 114                 udev_selinux_setfscreatecon(event->udev, filename, S_IFLNK);
 115                 symlink(udev_device_get_devpath(event->dev), filename);
 116                 udev_selinux_resetfscreatecon(event->udev);
 117                 break;
 118         case EVENT_FINISHED:
 119                 if (udev_device_get_devpath_old(event->dev) != NULL) {
 120                         /* "move" event - rename failed file to current name, do not delete failed */
 121                         char filename_failed_old[UTIL_PATH_SIZE];
 122
 123                         util_strlcpy(filename_failed_old, udev_get_dev_path(event->udev), sizeof(filename_failed_old));
 124                         util_strlcat(filename_failed_old, "/", sizeof(filename_failed_old));
 125                         start = util_strlcat(filename_failed_old, ".udev/failed/", sizeof(filename_failed_old));
 126                         util_strlcat(filename_failed_old, udev_device_get_devpath_old(event->dev), sizeof(filename_failed_old));
 127                         util_path_encode(&filename_failed_old[start], sizeof(filename) - start);
 128
 129                         if (rename(filename_failed_old, filename_failed) == 0)
 130                                 info(event->udev, "renamed devpath, moved failed state of '%s' to %s'\n",
 131                                      udev_device_get_devpath_old(event->dev), udev_device_get_devpath(event->dev));
 132                 } else {
 133                         if (unlink(filename_failed) == 0)
 134                                 util_delete_path(event->udev, filename_failed);
 135                 }
 136
 137                 unlink(filename);
 138
 139                 /* clean up possibly empty queue directory */
 140                 if (udev_list_is_empty(&exec_list) && udev_list_is_empty(&running_list))
 141                         util_delete_path(event->udev, filename);
 142                 break;
 143         case EVENT_FAILED:
 144                 /* move failed event to the failed directory */
 145                 util_create_path(event->udev, filename_failed);
 146                 rename(filename, filename_failed);
 147
 148                 /* clean up possibly empty queue directory */
 149                 if (udev_list_is_empty(&exec_list) && udev_list_is_empty(&running_list))
 150                         util_delete_path(event->udev, filename);
 151                 break;
 152         }
 153
 154         return;
 155 }
 156
 157 static void event_queue_delete(struct udev_event *event)
 158 {
 159         udev_list_node_remove(&event->node);
 160
 161         /* mark as failed, if "add" event returns non-zero */
 162         if (event->exitstatus && strcmp(udev_device_get_action(event->dev), "add") == 0)
 163                 export_event_state(event, EVENT_FAILED);
 164         else
 165                 export_event_state(event, EVENT_FINISHED);
 166
 167         udev_device_unref(event->dev);
 168         udev_event_unref(event);
 169 }
 170
 171 static void asmlinkage event_sig_handler(int signum)
 172 {
 173         if (signum == SIGALRM)
 174                 exit(1);
 175 }
 176
 177 static void event_fork(struct udev_event *event)
 178 {
 179         pid_t pid;
 180         struct sigaction act;
 181         int err;
 182
 183         pid = fork();
 184         switch (pid) {
 185         case 0:
 186                 /* child */
 187                 udev_monitor_unref(kernel_monitor);
 188                 udev_ctrl_unref(udev_ctrl);
 189                 if (inotify_fd >= 0)
 190                         close(inotify_fd);
 191                 close(signal_pipe[READ_END]);
 192                 close(signal_pipe[WRITE_END]);
 193                 logging_close();
 194                 logging_init("udevd-event");
 195                 setpriority(PRIO_PROCESS, 0, UDEV_PRIORITY);
 196
 197                 /* set signal handlers */
 198                 memset(&act, 0x00, sizeof(act));
 199                 act.sa_handler = (void (*)(int)) event_sig_handler;
 200                 sigemptyset (&act.sa_mask);
 201                 act.sa_flags = 0;
 202                 sigaction(SIGALRM, &act, NULL);
 203
 204                 /* reset to default */
 205                 act.sa_handler = SIG_DFL;
 206                 sigaction(SIGINT, &act, NULL);
 207                 sigaction(SIGTERM, &act, NULL);
 208                 sigaction(SIGCHLD, &act, NULL);
 209                 sigaction(SIGHUP, &act, NULL);
 210
 211                 /* set timeout to prevent hanging processes */
 212                 alarm(UDEV_EVENT_TIMEOUT);
 213
 214                 /* apply rules, create node, symlinks */
 215                 err = udev_event_execute_rules(event, rules);
 216
 217                 /* rules may change/disable the timeout */
 218                 if (udev_device_get_event_timeout(event->dev) >= 0)
 219                         alarm(udev_device_get_event_timeout(event->dev));
 220
 221                 /* execute RUN= */
 222                 if (err == 0 && !event->ignore_device && udev_get_run(event->udev))
 223                         udev_event_execute_run(event);
 224                 info(event->udev, "seq %llu exit with %i\n", udev_device_get_seqnum(event->dev), err);
 225                 logging_close();
 226                 if (err != 0)
 227                         exit(1);
 228                 exit(0);
 229         case -1:
 230                 err(event->udev, "fork of child failed: %m\n");
 231                 event_queue_delete(event);
 232                 break;
 233         default:
 234                 /* get SIGCHLD in main loop */
 235                 info(event->udev, "seq %llu forked, pid [%d], '%s' '%s', %ld seconds old\n",
 236                      udev_device_get_seqnum(event->dev),
 237                      pid,
 238                      udev_device_get_action(event->dev),
 239                      udev_device_get_subsystem(event->dev),
 240                      time(NULL) - event->queue_time);
 241                 event->pid = pid;
 242         }
 243 }
 244
 245 static void event_queue_insert(struct udev_event *event)
 246 {
 247         char filename[UTIL_PATH_SIZE];
 248         int fd;
 249
 250         event->queue_time = time(NULL);
 251
 252         export_event_state(event, EVENT_QUEUED);
 253         info(event->udev, "seq %llu queued, '%s' '%s'\n", udev_device_get_seqnum(event->dev),
 254              udev_device_get_action(event->dev), udev_device_get_subsystem(event->dev));
 255
 256         util_strlcpy(filename, udev_get_dev_path(event->udev), sizeof(filename));
 257         util_strlcat(filename, "/.udev/uevent_seqnum", sizeof(filename));
 258         fd = open(filename, O_WRONLY|O_TRUNC|O_CREAT, 0644);
 259         if (fd >= 0) {
 260                 char str[32];
 261                 int len;
 262
 263                 len = sprintf(str, "%llu\n", udev_device_get_seqnum(event->dev));
 264                 write(fd, str, len);
 265                 close(fd);
 266         }
 267
 268         /* run one event after the other in debug mode */
 269         if (debug_trace) {
 270                 udev_list_node_append(&event->node, &running_list);
 271                 event_fork(event);
 272                 waitpid(event->pid, NULL, 0);
 273                 event_queue_delete(event);
 274                 return;
 275         }
 276
 277         /* run all events with a timeout set immediately */
 278         if (udev_device_get_timeout(event->dev) > 0) {
 279                 udev_list_node_append(&event->node, &running_list);
 280                 event_fork(event);
 281                 return;
 282         }
 283
 284         udev_list_node_append(&event->node, &exec_list);
 285         run_exec_q = 1;
 286 }
 287
 288 static int mem_size_mb(void)
 289 {
 290         FILE* f;
 291         char buf[4096];
 292         long int memsize = -1;
 293
 294         f = fopen("/proc/meminfo", "r");
 295         if (f == NULL)
 296                 return -1;
 297
 298         while (fgets(buf, sizeof(buf), f) != NULL) {
 299                 long int value;
 300
 301                 if (sscanf(buf, "MemTotal: %ld kB", &value) == 1) {
 302                         memsize = value / 1024;
 303                         break;
 304                 }
 305         }
 306
 307         fclose(f);
 308         return memsize;
 309 }
 310
 311 static int compare_devpath(const char *running, const char *waiting)
 312 {
 313         int i = 0;
 314
 315         while (running[i] == waiting[i] && running[i] != '\0')
 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, int limit)
 336 {
 337         struct udev_list_node *loop;
 338         int childs_count = 0;
 339
 340         /* check exec-queue which may still contain delayed events we depend on */
 341         udev_list_node_foreach(loop, &exec_list) {
 342                 struct udev_event *loop_event = node_to_event(loop);
 343
 344                 /* skip ourself and all later events */
 345                 if (udev_device_get_seqnum(loop_event->dev) >= udev_device_get_seqnum(event->dev))
 346                         break;
 347
 348                 /* check our old name */
 349                 if (udev_device_get_devpath_old(event->dev) != NULL)
 350                         if (strcmp(udev_device_get_devpath(loop_event->dev), udev_device_get_devpath_old(event->dev)) == 0)
 351                                 return 2;
 352
 353                 /* check identical, parent, or child device event */
 354                 if (compare_devpath(udev_device_get_devpath(loop_event->dev), udev_device_get_devpath(event->dev)) != 0) {
 355                         dbg(event->udev, "%llu, device event still pending %llu (%s)\n",
 356                             udev_device_get_seqnum(event->dev),
 357                             udev_device_get_seqnum(loop_event->dev),
 358                             udev_device_get_devpath(loop_event->dev));
 359                         return 3;
 360                 }
 361
 362                 /* check for our major:minor number */
 363                 if (major(udev_device_get_devnum(event->dev)) > 0 &&
 364                     udev_device_get_devnum(loop_event->dev) == udev_device_get_devnum(event->dev) &&
 365                     strcmp(udev_device_get_subsystem(event->dev), udev_device_get_subsystem(loop_event->dev)) == 0) {
 366                         dbg(event->udev, "%llu, device event still pending %llu (%d:%d)\n",
 367                             udev_device_get_seqnum(event->dev),
 368                             udev_device_get_seqnum(loop_event->dev),
 369                             major(udev_device_get_devnum(loop_event->dev)), minor(udev_device_get_devnum(loop_event->dev)));
 370                         return 4;
 371                 }
 372
 373                 /* check physical device event (special case of parent) */
 374                 if (udev_device_get_physdevpath(event->dev) != NULL &&
 375                     strcmp(udev_device_get_action(event->dev), "add") == 0)
 376                         if (compare_devpath(udev_device_get_devpath(loop_event->dev),
 377                                             udev_device_get_physdevpath(event->dev)) != 0) {
 378                                 dbg(event->udev, "%llu, physical device event still pending %llu (%s)\n",
 379                                     udev_device_get_seqnum(event->dev),
 380                                     udev_device_get_seqnum(loop_event->dev),
 381                                     udev_device_get_devpath(loop_event->dev));
 382                                 return 5;
 383                         }
 384         }
 385
 386         /* check run queue for still running events */
 387         udev_list_node_foreach(loop, &running_list) {
 388                 struct udev_event *loop_event = node_to_event(loop);
 389
 390                 if (childs_count++ >= limit) {
 391                         info(event->udev, "%llu, maximum number (%i) of childs reached\n",
 392                              udev_device_get_seqnum(event->dev), childs_count);
 393                         return 1;
 394                 }
 395
 396                 /* check our old name */
 397                 if (udev_device_get_devpath_old(event->dev) != NULL)
 398                         if (strcmp(udev_device_get_devpath(loop_event->dev), udev_device_get_devpath_old(event->dev)) == 0)
 399                                 return 2;
 400
 401                 /* check identical, parent, or child device event */
 402                 if (compare_devpath(udev_device_get_devpath(loop_event->dev), udev_device_get_devpath(event->dev)) != 0) {
 403                         dbg(event->udev, "%llu, device event still running %llu (%s)\n",
 404                             udev_device_get_seqnum(event->dev),
 405                             udev_device_get_seqnum(loop_event->dev),
 406                             udev_device_get_devpath(loop_event->dev));
 407                         return 3;
 408                 }
 409
 410                 /* check for our major:minor number */
 411                 if (major(udev_device_get_devnum(event->dev)) > 0 &&
 412                     udev_device_get_devnum(loop_event->dev) == udev_device_get_devnum(event->dev) &&
 413                     strcmp(udev_device_get_subsystem(event->dev), udev_device_get_subsystem(loop_event->dev)) == 0) {
 414                         dbg(event->udev, "%llu, device event still pending %llu (%d:%d)\n",
 415                             udev_device_get_seqnum(event->dev),
 416                             udev_device_get_seqnum(loop_event->dev),
 417                             major(udev_device_get_devnum(loop_event->dev)), minor(udev_device_get_devnum(loop_event->dev)));
 418                         return 4;
 419                 }
 420
 421                 /* check physical device event (special case of parent) */
 422                 if (udev_device_get_physdevpath(event->dev) != NULL &&
 423                     strcmp(udev_device_get_action(event->dev), "add") == 0)
 424                         if (compare_devpath(udev_device_get_devpath(loop_event->dev),
 425                                             udev_device_get_physdevpath(event->dev)) != 0) {
 426                                 dbg(event->udev, "%llu, physical device event still pending %llu (%s)\n",
 427                                     udev_device_get_seqnum(event->dev),
 428                                     udev_device_get_seqnum(loop_event->dev),
 429                                     udev_device_get_devpath(loop_event->dev));
 430                                 return 5;
 431                         }
 432         }
 433         return 0;
 434 }
 435
 436 /* serializes events for the identical and parent and child devices */
 437 static void event_queue_manager(struct udev *udev)
 438 {
 439         struct udev_list_node *loop;
 440         struct udev_list_node *tmp;
 441
 442         if (udev_list_is_empty(&exec_list))
 443                 return;
 444
 445         udev_list_node_foreach_safe(loop, tmp, &exec_list) {
 446                 struct udev_event *loop_event = node_to_event(loop);
 447
 448                 /* serialize and wait for parent or child events */
 449                 if (devpath_busy(loop_event, max_childs) != 0) {
 450                         dbg(udev, "delay seq %llu (%s)\n",
 451                             udev_device_get_seqnum(loop_event->dev),
 452                             udev_device_get_devpath(loop_event->dev));
 453                         continue;
 454                 }
 455
 456                 /* move event to run list */
 457                 udev_list_node_remove(&loop_event->node);
 458                 udev_list_node_append(&loop_event->node, &running_list);
 459                 event_fork(loop_event);
 460                 dbg(udev, "moved seq %llu to running list\n", udev_device_get_seqnum(loop_event->dev));
 461         }
 462 }
 463
 464 /* receive the udevd message from userspace */
 465 static void handle_ctrl_msg(struct udev_ctrl *uctrl)
 466 {
 467         struct udev *udev = udev_ctrl_get_udev(uctrl);
 468         struct udev_ctrl_msg *ctrl_msg;
 469         const char *str;
 470         int i;
 471
 472         ctrl_msg = udev_ctrl_receive_msg(uctrl);
 473         if (ctrl_msg == NULL)
 474                 return;
 475
 476         i = udev_ctrl_get_set_log_level(ctrl_msg);
 477         if (i >= 0) {
 478                 info(udev, "udevd message (SET_LOG_PRIORITY) received, log_priority=%i\n", i);
 479                 udev_set_log_priority(udev, i);
 480         }
 481
 482         if (udev_ctrl_get_stop_exec_queue(ctrl_msg) > 0) {
 483                 info(udev, "udevd message (STOP_EXEC_QUEUE) received\n");
 484                 stop_exec_q = 1;
 485         }
 486
 487         if (udev_ctrl_get_start_exec_queue(ctrl_msg) > 0) {
 488                 info(udev, "udevd message (START_EXEC_QUEUE) received\n");
 489                 stop_exec_q = 0;
 490                 event_queue_manager(udev);
 491         }
 492
 493         if (udev_ctrl_get_reload_rules(ctrl_msg) > 0) {
 494                 info(udev, "udevd message (RELOAD_RULES) received\n");
 495                 reload_config = 1;
 496         }
 497
 498         str = udev_ctrl_get_set_env(ctrl_msg);
 499         if (str != NULL) {
 500                 char *key;
 501
 502                 key = strdup(str);
 503                 if (key != NULL) {
 504                         char *val;
 505
 506                         val = strchr(key, '=');
 507                         if (val != NULL) {
 508                                 val[0] = '\0';
 509                                 val = &val[1];
 510                                 if (val[0] == '\0') {
 511                                         info(udev, "udevd message (ENV) received, unset '%s'\n", key);
 512                                         udev_add_property(udev, key, NULL);
 513                                 } else {
 514                                         info(udev, "udevd message (ENV) received, set '%s=%s'\n", key, val);
 515                                         udev_add_property(udev, key, val);
 516                                 }
 517                         } else {
 518                                 err(udev, "wrong key format '%s'\n", key);
 519                         }
 520                         free(key);
 521                 }
 522         }
 523
 524         i = udev_ctrl_get_set_max_childs(ctrl_msg);
 525         if (i >= 0) {
 526                 info(udev, "udevd message (SET_MAX_CHILDS) received, max_childs=%i\n", i);
 527                 max_childs = i;
 528         }
 529
 530         udev_ctrl_msg_unref(ctrl_msg);
 531 }
 532
 533 static void asmlinkage sig_handler(int signum)
 534 {
 535         switch (signum) {
 536                 case SIGINT:
 537                 case SIGTERM:
 538                         udev_exit = 1;
 539                         break;
 540                 case SIGCHLD:
 541                         /* set flag, then write to pipe if needed */
 542                         sigchilds_waiting = 1;
 543                         break;
 544                 case SIGHUP:
 545                         reload_config = 1;
 546                         break;
 547         }
 548
 549         /* write to pipe, which will wakeup select() in our mainloop */
 550         write(signal_pipe[WRITE_END], "", 1);
 551 }
 552
 553 static void udev_done(int pid, int exitstatus)
 554 {
 555         struct udev_list_node *loop;
 556
 557         /* find event associated with pid and delete it */
 558         udev_list_node_foreach(loop, &running_list) {
 559                 struct udev_event *loop_event = node_to_event(loop);
 560
 561                 if (loop_event->pid == pid) {
 562                         info(loop_event->udev, "seq %llu cleanup, pid [%d], status %i, %ld seconds old\n",
 563                              udev_device_get_seqnum(loop_event->dev), loop_event->pid,
 564                              exitstatus, time(NULL) - loop_event->queue_time);
 565                         loop_event->exitstatus = exitstatus;
 566                         event_queue_delete(loop_event);
 567
 568                         /* there may be events waiting with the same devpath */
 569                         run_exec_q = 1;
 570                         return;
 571                 }
 572         }
 573 }
 574
 575 static void reap_sigchilds(void)
 576 {
 577         pid_t pid;
 578         int status;
 579
 580         while (1) {
 581                 pid = waitpid(-1, &status, WNOHANG);
 582                 if (pid <= 0)
 583                         break;
 584                 if (WIFEXITED(status))
 585                         status = WEXITSTATUS(status);
 586                 else if (WIFSIGNALED(status))
 587                         status = WTERMSIG(status) + 128;
 588                 else
 589                         status = 0;
 590                 udev_done(pid, status);
 591         }
 592 }
 593
 594 static void export_initial_seqnum(struct udev *udev)
 595 {
 596         char filename[UTIL_PATH_SIZE];
 597         int fd;
 598         char seqnum[32];
 599         ssize_t len = 0;
 600
 601         util_strlcpy(filename, udev_get_sys_path(udev), sizeof(filename));
 602         util_strlcat(filename, "/kernel/uevent_seqnum", sizeof(filename));
 603         fd = open(filename, O_RDONLY);
 604         if (fd >= 0) {
 605                 len = read(fd, seqnum, sizeof(seqnum)-1);
 606                 close(fd);
 607         }
 608         if (len <= 0) {
 609                 strcpy(seqnum, "0\n");
 610                 len = 3;
 611         }
 612         util_strlcpy(filename, udev_get_dev_path(udev), sizeof(filename));
 613         util_strlcat(filename, "/.udev/uevent_seqnum", sizeof(filename));
 614         util_create_path(udev, filename);
 615         fd = open(filename, O_WRONLY|O_TRUNC|O_CREAT, 0644);
 616         if (fd >= 0) {
 617                 write(fd, seqnum, len);
 618                 close(fd);
 619         }
 620 }
 621
 622 int main(int argc, char *argv[])
 623 {
 624         struct udev *udev;
 625         int err;
 626         int fd;
 627         struct sigaction act;
 628         fd_set readfds;
 629         const char *value;
 630         int daemonize = 0;
 631         static const struct option options[] = {
 632                 { "daemon", no_argument, NULL, 'd' },
 633                 { "debug-trace", no_argument, NULL, 't' },
 634                 { "debug", no_argument, NULL, 'D' },
 635                 { "help", no_argument, NULL, 'h' },
 636                 { "version", no_argument, NULL, 'V' },
 637                 {}
 638         };
 639         int rc = 1;
 640         int maxfd;
 641
 642         udev = udev_new();
 643         if (udev == NULL)
 644                 goto exit;
 645
 646         logging_init("udevd");
 647         udev_set_log_fn(udev, log_fn);
 648         info(udev, "version %s\n", VERSION);
 649         udev_selinux_init(udev);
 650
 651         while (1) {
 652                 int option;
 653
 654                 option = getopt_long(argc, argv, "dDthV", options, NULL);
 655                 if (option == -1)
 656                         break;
 657
 658                 switch (option) {
 659                 case 'd':
 660                         daemonize = 1;
 661                         break;
 662                 case 't':
 663                         debug_trace = 1;
 664                         break;
 665                 case 'D':
 666                         debug = 1;
 667                         if (udev_get_log_priority(udev) < LOG_INFO)
 668                                 udev_set_log_priority(udev, LOG_INFO);
 669                         break;
 670                 case 'h':
 671                         printf("Usage: udevd [--help] [--daemon] [--debug-trace] [--debug] [--version]\n");
 672                         goto exit;
 673                 case 'V':
 674                         printf("%s\n", VERSION);
 675                         goto exit;
 676                 default:
 677                         goto exit;
 678                 }
 679         }
 680
 681         if (getuid() != 0) {
 682                 fprintf(stderr, "root privileges required\n");
 683                 err(udev, "root privileges required\n");
 684                 goto exit;
 685         }
 686
 687         /* make sure std{in,out,err} fd's are in a sane state */
 688         fd = open("/dev/null", O_RDWR);
 689         if (fd < 0) {
 690                 fprintf(stderr, "cannot open /dev/null\n");
 691                 err(udev, "cannot open /dev/null\n");
 692         }
 693         if (fd > STDIN_FILENO)
 694                 dup2(fd, STDIN_FILENO);
 695         if (write(STDOUT_FILENO, 0, 0) < 0)
 696                 dup2(fd, STDOUT_FILENO);
 697         if (write(STDERR_FILENO, 0, 0) < 0)
 698                 dup2(fd, STDERR_FILENO);
 699
 700         /* init control socket, bind() ensures, that only one udevd instance is running */
 701         udev_ctrl = udev_ctrl_new_from_socket(udev, UDEV_CTRL_SOCK_PATH);
 702         if (udev_ctrl == NULL) {
 703                 fprintf(stderr, "error initializing control socket");
 704                 err(udev, "error initializing udevd socket");
 705                 rc = 1;
 706                 goto exit;
 707         }
 708
 709         if (udev_ctrl_enable_receiving(udev_ctrl) < 0) {
 710                 fprintf(stderr, "error binding control socket, seems udevd is already running\n");
 711                 err(udev, "error binding control socket, seems udevd is already running\n");
 712                 rc = 1;
 713                 goto exit;
 714         }
 715
 716         kernel_monitor = udev_monitor_new_from_netlink(udev);
 717         if (kernel_monitor == NULL || udev_monitor_enable_receiving(kernel_monitor) < 0) {
 718                 fprintf(stderr, "error initializing netlink socket\n");
 719                 err(udev, "error initializing netlink socket\n");
 720                 rc = 3;
 721                 goto exit;
 722         }
 723         udev_monitor_set_receive_buffer_size(kernel_monitor, 128*1024*1024);
 724
 725         err = pipe(signal_pipe);
 726         if (err < 0) {
 727                 err(udev, "error getting pipes: %m\n");
 728                 goto exit;
 729         }
 730
 731         err = fcntl(signal_pipe[READ_END], F_GETFL, 0);
 732         if (err < 0) {
 733                 err(udev, "error fcntl on read pipe: %m\n");
 734                 goto exit;
 735         }
 736         err = fcntl(signal_pipe[READ_END], F_SETFL, err | O_NONBLOCK);
 737         if (err < 0) {
 738                 err(udev, "error fcntl on read pipe: %m\n");
 739                 goto exit;
 740         }
 741
 742         err = fcntl(signal_pipe[WRITE_END], F_GETFL, 0);
 743         if (err < 0) {
 744                 err(udev, "error fcntl on write pipe: %m\n");
 745                 goto exit;
 746         }
 747         err = fcntl(signal_pipe[WRITE_END], F_SETFL, err | O_NONBLOCK);
 748         if (err < 0) {
 749                 err(udev, "error fcntl on write pipe: %m\n");
 750                 goto exit;
 751         }
 752
 753         rules = udev_rules_new(udev, 1);
 754         if (rules == NULL) {
 755                 err(udev, "error reading rules\n");
 756                 goto exit;
 757         }
 758         udev_list_init(&running_list);
 759         udev_list_init(&exec_list);
 760         export_initial_seqnum(udev);
 761
 762         if (daemonize) {
 763                 pid_t pid;
 764
 765                 pid = fork();
 766                 switch (pid) {
 767                 case 0:
 768                         dbg(udev, "daemonized fork running\n");
 769                         break;
 770                 case -1:
 771                         err(udev, "fork of daemon failed: %m\n");
 772                         rc = 4;
 773                         goto exit;
 774                 default:
 775                         dbg(udev, "child [%u] running, parent exits\n", pid);
 776                         rc = 0;
 777                         goto exit;
 778                 }
 779         }
 780
 781         /* redirect std{out,err} */
 782         if (!debug) {
 783                 dup2(fd, STDOUT_FILENO);
 784                 dup2(fd, STDERR_FILENO);
 785         }
 786         if (fd > STDERR_FILENO)
 787                 close(fd);
 788
 789         /* set scheduling priority for the daemon */
 790         setpriority(PRIO_PROCESS, 0, UDEVD_PRIORITY);
 791
 792         chdir("/");
 793         umask(022);
 794         setsid();
 795
 796         /* OOM_DISABLE == -17 */
 797         fd = open("/proc/self/oom_adj", O_RDWR);
 798         if (fd < 0)
 799                 err(udev, "error disabling OOM: %m\n");
 800         else {
 801                 write(fd, "-17", 3);
 802                 close(fd);
 803         }
 804
 805         fd = open("/dev/kmsg", O_WRONLY);
 806         if (fd > 0) {
 807                 const char *ver_str = "<6>udev: starting version " VERSION "\n";
 808                 char path[UTIL_PATH_SIZE];
 809                 struct stat statbuf;
 810
 811                 write(fd, ver_str, strlen(ver_str));
 812                 util_strlcpy(path, udev_get_sys_path(udev), sizeof(path));
 813                 util_strlcat(path, "/class/mem/null", sizeof(path));
 814                 if (lstat(path, &statbuf) == 0) {
 815                         if (S_ISDIR(statbuf.st_mode)) {
 816                                 const char *depr_str = "<6>udev: deprecated sysfs layout (kernel too old, "
 817                                                         "or CONFIG_SYSFS_DEPRECATED) is unsupported, some "
 818                                                         "udev features may fail\n";
 819
 820                                 write(fd, depr_str, strlen(depr_str));
 821                         }
 822                 }
 823                 close(fd);
 824         }
 825
 826         /* set signal handlers */
 827         memset(&act, 0x00, sizeof(struct sigaction));
 828         act.sa_handler = (void (*)(int)) sig_handler;
 829         sigemptyset(&act.sa_mask);
 830         act.sa_flags = SA_RESTART;
 831         sigaction(SIGINT, &act, NULL);
 832         sigaction(SIGTERM, &act, NULL);
 833         sigaction(SIGCHLD, &act, NULL);
 834         sigaction(SIGHUP, &act, NULL);
 835
 836         /* watch rules directory */
 837         inotify_fd = inotify_init();
 838         if (inotify_fd >= 0) {
 839                 if (udev_get_rules_path(udev) != NULL) {
 840                         inotify_add_watch(inotify_fd, udev_get_rules_path(udev),
 841                                           IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
 842                 } else {
 843                         char filename[PATH_MAX];
 844
 845                         inotify_add_watch(inotify_fd, UDEV_PREFIX "/lib/udev/rules.d",
 846                                           IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
 847                         inotify_add_watch(inotify_fd, SYSCONFDIR "/udev/rules.d",
 848                                           IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
 849
 850                         /* watch dynamic rules directory */
 851                         util_strlcpy(filename, udev_get_dev_path(udev), sizeof(filename));
 852                         util_strlcat(filename, "/.udev/rules.d", sizeof(filename));
 853                         inotify_add_watch(inotify_fd, filename,
 854                                           IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
 855                 }
 856         } else if (errno == ENOSYS)
 857                 err(udev, "the kernel does not support inotify, udevd can't monitor rules file changes\n");
 858         else
 859                 err(udev, "inotify_init failed: %m\n");
 860
 861         /* maximum limit of forked childs */
 862         value = getenv("UDEVD_MAX_CHILDS");
 863         if (value)
 864                 max_childs = strtoul(value, NULL, 10);
 865         else {
 866                 int memsize = mem_size_mb();
 867                 if (memsize > 0)
 868                         max_childs = 128 + (memsize / 4);
 869                 else
 870                         max_childs = UDEVD_MAX_CHILDS;
 871         }
 872         info(udev, "initialize max_childs to %u\n", max_childs);
 873
 874         maxfd = udev_ctrl_get_fd(udev_ctrl);
 875         maxfd = UDEV_MAX(maxfd, udev_monitor_get_fd(kernel_monitor));
 876         maxfd = UDEV_MAX(maxfd, signal_pipe[READ_END]);
 877         maxfd = UDEV_MAX(maxfd, inotify_fd);
 878         while (!udev_exit) {
 879                 int fdcount;
 880
 881                 FD_ZERO(&readfds);
 882                 FD_SET(signal_pipe[READ_END], &readfds);
 883                 FD_SET(udev_ctrl_get_fd(udev_ctrl), &readfds);
 884                 FD_SET(udev_monitor_get_fd(kernel_monitor), &readfds);
 885                 if (inotify_fd >= 0)
 886                         FD_SET(inotify_fd, &readfds);
 887                 fdcount = select(maxfd+1, &readfds, NULL, NULL, NULL);
 888                 if (fdcount < 0) {
 889                         if (errno != EINTR)
 890                                 err(udev, "error in select: %m\n");
 891                         continue;
 892                 }
 893
 894                 /* get control message */
 895                 if (FD_ISSET(udev_ctrl_get_fd(udev_ctrl), &readfds))
 896                         handle_ctrl_msg(udev_ctrl);
 897
 898                 /* get kernel uevent */
 899                 if (FD_ISSET(udev_monitor_get_fd(kernel_monitor), &readfds)) {
 900                         struct udev_device *dev;
 901
 902                         dev = udev_monitor_receive_device(kernel_monitor);
 903                         if (dev != NULL) {
 904                                 struct udev_event *event;
 905
 906                                 event = udev_event_new(dev);
 907                                 if (event != NULL)
 908                                         event_queue_insert(event);
 909                                 else
 910                                         udev_device_unref(dev);
 911                         }
 912                 }
 913
 914                 /* received a signal, clear our notification pipe */
 915                 if (FD_ISSET(signal_pipe[READ_END], &readfds)) {
 916                         char buf[256];
 917
 918                         read(signal_pipe[READ_END], &buf, sizeof(buf));
 919                 }
 920
 921                 /* rules directory inotify watch */
 922                 if ((inotify_fd >= 0) && FD_ISSET(inotify_fd, &readfds)) {
 923                         int nbytes;
 924
 925                         /* discard all possible events, we can just reload the config */
 926                         if ((ioctl(inotify_fd, FIONREAD, &nbytes) == 0) && nbytes > 0) {
 927                                 char *buf;
 928
 929                                 reload_config = 1;
 930                                 buf = malloc(nbytes);
 931                                 if (buf == NULL) {
 932                                         err(udev, "error getting buffer for inotify, disable watching\n");
 933                                         close(inotify_fd);
 934                                         inotify_fd = -1;
 935                                 }
 936                                 read(inotify_fd, buf, nbytes);
 937                                 free(buf);
 938                         }
 939                 }
 940
 941                 /* rules changed, set by inotify or a HUP signal */
 942                 if (reload_config) {
 943                         struct udev_rules *rules_new;
 944
 945                         reload_config = 0;
 946                         rules_new = udev_rules_new(udev, 1);
 947                         if (rules_new != NULL) {
 948                                 udev_rules_unref(rules);
 949                                 rules = rules_new;
 950                         }
 951                 }
 952
 953                 if (sigchilds_waiting) {
 954                         sigchilds_waiting = 0;
 955                         reap_sigchilds();
 956                 }
 957
 958                 if (run_exec_q) {
 959                         run_exec_q = 0;
 960                         if (!stop_exec_q)
 961                                 event_queue_manager(udev);
 962                 }
 963         }
 964         rc = 0;
 965
 966 exit:
 967         udev_rules_unref(rules);
 968
 969         if (signal_pipe[READ_END] >= 0)
 970                 close(signal_pipe[READ_END]);
 971         if (signal_pipe[WRITE_END] >= 0)
 972                 close(signal_pipe[WRITE_END]);
 973
 974         udev_ctrl_unref(udev_ctrl);
 975         if (inotify_fd >= 0)
 976                 close(inotify_fd);
 977         udev_monitor_unref(kernel_monitor);
 978
 979         udev_selinux_exit(udev);
 980         udev_unref(udev);
 981         logging_close();
 982         return rc;
 983 }