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 volatile int sigchilds_waiting;
  69 static volatile int udev_exit;
  70 static volatile int reload_config;
  71 static volatile int signal_received;
  72 static int run_exec_q;
  73 static int stop_exec_q;
  74 static int max_childs;
  75 static int childs;
  76 static struct udev_list_node event_list;
  77
  78 enum event_state {
  79         EVENT_QUEUED,
  80         EVENT_FINISHED,
  81         EVENT_FAILED,
  82 };
  83
  84 static struct udev_event *node_to_event(struct udev_list_node *node)
  85 {
  86         char *event;
  87
  88         event = (char *)node;
  89         event -= offsetof(struct udev_event, node);
  90         return (struct udev_event *)event;
  91 }
  92
  93 static void export_event_state(struct udev_event *event, enum event_state state)
  94 {
  95         char filename[UTIL_PATH_SIZE];
  96         char filename_failed[UTIL_PATH_SIZE];
  97         size_t start;
  98
  99         /* location of queue file */
 100         snprintf(filename, sizeof(filename), "%s/.udev/queue/%llu",
 101                  udev_get_dev_path(event->udev), udev_device_get_seqnum(event->dev));
 102
 103         /* location of failed file */
 104         util_strlcpy(filename_failed, udev_get_dev_path(event->udev), sizeof(filename_failed));
 105         util_strlcat(filename_failed, "/", sizeof(filename_failed));
 106         start = util_strlcat(filename_failed, ".udev/failed/", sizeof(filename_failed));
 107         util_strlcat(filename_failed, udev_device_get_devpath(event->dev), sizeof(filename_failed));
 108         util_path_encode(&filename_failed[start], sizeof(filename_failed) - start);
 109
 110         switch (state) {
 111         case EVENT_QUEUED:
 112                 if(unlink(filename_failed) == 0)
 113                         util_delete_path(event->udev, filename_failed);
 114                 util_create_path(event->udev, filename);
 115                 udev_selinux_setfscreatecon(event->udev, filename, S_IFLNK);
 116                 symlink(udev_device_get_devpath(event->dev), filename);
 117                 udev_selinux_resetfscreatecon(event->udev);
 118                 break;
 119         case EVENT_FINISHED:
 120                 if (udev_device_get_devpath_old(event->dev) != NULL) {
 121                         /* "move" event - rename failed file to current name, do not delete failed */
 122                         char filename_failed_old[UTIL_PATH_SIZE];
 123
 124                         util_strlcpy(filename_failed_old, udev_get_dev_path(event->udev), sizeof(filename_failed_old));
 125                         util_strlcat(filename_failed_old, "/", sizeof(filename_failed_old));
 126                         start = util_strlcat(filename_failed_old, ".udev/failed/", sizeof(filename_failed_old));
 127                         util_strlcat(filename_failed_old, udev_device_get_devpath_old(event->dev), sizeof(filename_failed_old));
 128                         util_path_encode(&filename_failed_old[start], sizeof(filename) - start);
 129
 130                         if (rename(filename_failed_old, filename_failed) == 0)
 131                                 info(event->udev, "renamed devpath, moved failed state of '%s' to %s'\n",
 132                                      udev_device_get_devpath_old(event->dev), udev_device_get_devpath(event->dev));
 133                 } else {
 134                         if (unlink(filename_failed) == 0)
 135                                 util_delete_path(event->udev, filename_failed);
 136                 }
 137
 138                 unlink(filename);
 139
 140                 /* clean up possibly empty queue directory */
 141                 if (udev_list_is_empty(&event_list))
 142                         util_delete_path(event->udev, filename);
 143                 break;
 144         case EVENT_FAILED:
 145                 /* move failed event to the failed directory */
 146                 util_create_path(event->udev, filename_failed);
 147                 rename(filename, filename_failed);
 148
 149                 /* clean up possibly empty queue directory */
 150                 if (udev_list_is_empty(&event_list))
 151                         util_delete_path(event->udev, filename);
 152                 break;
 153         }
 154
 155         return;
 156 }
 157
 158 static void event_queue_delete(struct udev_event *event)
 159 {
 160         udev_list_node_remove(&event->node);
 161
 162         /* mark as failed, if "add" event returns non-zero */
 163         if (event->exitstatus && strcmp(udev_device_get_action(event->dev), "add") == 0)
 164                 export_event_state(event, EVENT_FAILED);
 165         else
 166                 export_event_state(event, EVENT_FINISHED);
 167
 168         udev_device_unref(event->dev);
 169         udev_event_unref(event);
 170 }
 171
 172 static void asmlinkage event_sig_handler(int signum)
 173 {
 174         if (signum == SIGALRM)
 175                 exit(1);
 176 }
 177
 178 static void event_fork(struct udev_event *event)
 179 {
 180         pid_t pid;
 181         struct sigaction act;
 182         int err;
 183
 184         if (debug_trace) {
 185                 event->trace = 1;
 186                 fprintf(stderr, "fork %s (%llu)\n",
 187                        udev_device_get_syspath(event->dev),
 188                        udev_device_get_seqnum(event->dev));
 189         }
 190
 191         pid = fork();
 192         switch (pid) {
 193         case 0:
 194                 /* child */
 195                 udev_monitor_unref(kernel_monitor);
 196                 udev_ctrl_unref(udev_ctrl);
 197                 logging_close();
 198                 logging_init("udevd-event");
 199                 setpriority(PRIO_PROCESS, 0, UDEV_PRIORITY);
 200
 201                 /* set signal handlers */
 202                 memset(&act, 0x00, sizeof(act));
 203                 act.sa_handler = (void (*)(int)) event_sig_handler;
 204                 sigemptyset (&act.sa_mask);
 205                 act.sa_flags = 0;
 206                 sigaction(SIGALRM, &act, NULL);
 207
 208                 /* reset to default */
 209                 act.sa_handler = SIG_DFL;
 210                 sigaction(SIGINT, &act, NULL);
 211                 sigaction(SIGTERM, &act, NULL);
 212                 sigaction(SIGCHLD, &act, NULL);
 213                 sigaction(SIGHUP, &act, NULL);
 214
 215                 /* set timeout to prevent hanging processes */
 216                 alarm(UDEV_EVENT_TIMEOUT);
 217
 218                 /* apply rules, create node, symlinks */
 219                 err = udev_event_execute_rules(event, rules);
 220
 221                 /* rules may change/disable the timeout */
 222                 if (udev_device_get_event_timeout(event->dev) >= 0)
 223                         alarm(udev_device_get_event_timeout(event->dev));
 224
 225                 /* execute RUN= */
 226                 if (err == 0 && !event->ignore_device && udev_get_run(event->udev))
 227                         udev_event_execute_run(event);
 228
 229                 /* apply/restore inotify watch */
 230                 if (err == 0 && event->inotify_watch) {
 231                         udev_watch_begin(event->udev, event->dev);
 232                         udev_device_update_db(event->dev);
 233                 }
 234
 235                 info(event->udev, "seq %llu exit with %i\n", udev_device_get_seqnum(event->dev), err);
 236                 logging_close();
 237                 if (err != 0)
 238                         exit(1);
 239                 exit(0);
 240         case -1:
 241                 err(event->udev, "fork of child failed: %m\n");
 242                 event_queue_delete(event);
 243                 break;
 244         default:
 245                 /* get SIGCHLD in main loop */
 246                 info(event->udev, "seq %llu forked, pid [%d], '%s' '%s', %ld seconds old\n",
 247                      udev_device_get_seqnum(event->dev),
 248                      pid,
 249                      udev_device_get_action(event->dev),
 250                      udev_device_get_subsystem(event->dev),
 251                      time(NULL) - event->queue_time);
 252                 event->pid = pid;
 253                 childs++;
 254         }
 255 }
 256
 257 static void event_queue_insert(struct udev_event *event)
 258 {
 259         char filename[UTIL_PATH_SIZE];
 260         int fd;
 261
 262         event->queue_time = time(NULL);
 263
 264         export_event_state(event, EVENT_QUEUED);
 265         info(event->udev, "seq %llu queued, '%s' '%s'\n", udev_device_get_seqnum(event->dev),
 266              udev_device_get_action(event->dev), udev_device_get_subsystem(event->dev));
 267
 268         util_strlcpy(filename, udev_get_dev_path(event->udev), sizeof(filename));
 269         util_strlcat(filename, "/.udev/uevent_seqnum", sizeof(filename));
 270         fd = open(filename, O_WRONLY|O_TRUNC|O_CREAT, 0644);
 271         if (fd >= 0) {
 272                 char str[32];
 273                 int len;
 274
 275                 len = sprintf(str, "%llu\n", udev_device_get_seqnum(event->dev));
 276                 write(fd, str, len);
 277                 close(fd);
 278         }
 279
 280
 281         udev_list_node_append(&event->node, &event_list);
 282         run_exec_q = 1;
 283
 284         /* run all events with a timeout set immediately */
 285         if (udev_device_get_timeout(event->dev) > 0) {
 286                 event_fork(event);
 287                 return;
 288         }
 289 }
 290
 291 static int mem_size_mb(void)
 292 {
 293         FILE* f;
 294         char buf[4096];
 295         long int memsize = -1;
 296
 297         f = fopen("/proc/meminfo", "r");
 298         if (f == NULL)
 299                 return -1;
 300
 301         while (fgets(buf, sizeof(buf), f) != NULL) {
 302                 long int value;
 303
 304                 if (sscanf(buf, "MemTotal: %ld kB", &value) == 1) {
 305                         memsize = value / 1024;
 306                         break;
 307                 }
 308         }
 309
 310         fclose(f);
 311         return memsize;
 312 }
 313
 314 static int compare_devpath(const char *running, const char *waiting)
 315 {
 316         int i = 0;
 317
 318         while (running[i] != '\0' && running[i] == waiting[i])
 319                 i++;
 320
 321         /* identical device event found */
 322         if (running[i] == '\0' && waiting[i] == '\0')
 323                 return 1;
 324
 325         /* parent device event found */
 326         if (running[i] == '\0' && waiting[i] == '/')
 327                 return 2;
 328
 329         /* child device event found */
 330         if (running[i] == '/' && waiting[i] == '\0')
 331                 return 3;
 332
 333         /* no matching event */
 334         return 0;
 335 }
 336
 337 /* lookup event for identical, parent, child, or physical device */
 338 static int devpath_busy(struct udev_event *event)
 339 {
 340         struct udev_list_node *loop;
 341
 342         if (event->delaying_seqnum > 0) {
 343         }
 344         /* check if queue contains events we depend on */
 345         udev_list_node_foreach(loop, &event_list) {
 346                 struct udev_event *loop_event = node_to_event(loop);
 347
 348                 /* we already found a later event, earlier can not block us, no need to check again */
 349                 if (udev_device_get_seqnum(loop_event->dev) < event->delaying_seqnum)
 350                         continue;
 351
 352                 /* event we checked earlier still exists, no need to check again */
 353                 if (udev_device_get_seqnum(loop_event->dev) == event->delaying_seqnum)
 354                         return 2;
 355
 356                 /* found ourself, no later event can block us */
 357                 if (udev_device_get_seqnum(loop_event->dev) >= udev_device_get_seqnum(event->dev))
 358                         break;
 359
 360                 /* check our old name */
 361                 if (udev_device_get_devpath_old(event->dev) != NULL)
 362                         if (strcmp(udev_device_get_devpath(loop_event->dev), udev_device_get_devpath_old(event->dev)) == 0) {
 363                                 event->delaying_seqnum = udev_device_get_seqnum(loop_event->dev);
 364                                 return 3;
 365                         }
 366
 367                 /* check identical, parent, or child device event */
 368                 if (compare_devpath(udev_device_get_devpath(loop_event->dev), udev_device_get_devpath(event->dev)) != 0) {
 369                         dbg(event->udev, "%llu, device event still pending %llu (%s)\n",
 370                             udev_device_get_seqnum(event->dev),
 371                             udev_device_get_seqnum(loop_event->dev),
 372                             udev_device_get_devpath(loop_event->dev));
 373                         event->delaying_seqnum = udev_device_get_seqnum(loop_event->dev);
 374                         return 4;
 375                 }
 376
 377                 /* check for our major:minor number */
 378                 if (major(udev_device_get_devnum(event->dev)) > 0 &&
 379                     udev_device_get_devnum(loop_event->dev) == udev_device_get_devnum(event->dev) &&
 380                     strcmp(udev_device_get_subsystem(event->dev), udev_device_get_subsystem(loop_event->dev)) == 0) {
 381                         dbg(event->udev, "%llu, device event still pending %llu (%d:%d)\n",
 382                             udev_device_get_seqnum(event->dev),
 383                             udev_device_get_seqnum(loop_event->dev),
 384                             major(udev_device_get_devnum(loop_event->dev)), minor(udev_device_get_devnum(loop_event->dev)));
 385                         event->delaying_seqnum = udev_device_get_seqnum(loop_event->dev);
 386                         return 5;
 387                 }
 388
 389                 /* check physical device event (special case of parent) */
 390                 if (udev_device_get_physdevpath(event->dev) != NULL &&
 391                     strcmp(udev_device_get_action(event->dev), "add") == 0)
 392                         if (compare_devpath(udev_device_get_devpath(loop_event->dev),
 393                                             udev_device_get_physdevpath(event->dev)) != 0) {
 394                                 dbg(event->udev, "%llu, physical device event still pending %llu (%s)\n",
 395                                     udev_device_get_seqnum(event->dev),
 396                                     udev_device_get_seqnum(loop_event->dev),
 397                                     udev_device_get_devpath(loop_event->dev));
 398                                 event->delaying_seqnum = udev_device_get_seqnum(loop_event->dev);
 399                                 return 6;
 400                         }
 401         }
 402         return 0;
 403 }
 404
 405 /* serializes events for the identical and parent and child devices */
 406 static void event_queue_manager(struct udev *udev)
 407 {
 408         struct udev_list_node *loop;
 409         struct udev_list_node *tmp;
 410
 411 start_over:
 412         if (udev_list_is_empty(&event_list)) {
 413                 if (childs > 0) {
 414                         err(udev, "event list empty, but childs count is %i", childs);
 415                         childs = 0;
 416                 }
 417                 return;
 418         }
 419
 420         udev_list_node_foreach_safe(loop, tmp, &event_list) {
 421                 struct udev_event *loop_event = node_to_event(loop);
 422
 423                 if (childs >= max_childs) {
 424                         info(udev, "maximum number (%i) of childs reached\n", childs);
 425                         break;
 426                 }
 427
 428                 if (loop_event->pid != 0)
 429                         continue;
 430
 431                 /* do not start event if parent or child event is still running */
 432                 if (devpath_busy(loop_event) != 0) {
 433                         dbg(udev, "delay seq %llu (%s)\n",
 434                             udev_device_get_seqnum(loop_event->dev),
 435                             udev_device_get_devpath(loop_event->dev));
 436                         continue;
 437                 }
 438
 439                 event_fork(loop_event);
 440                 dbg(udev, "moved seq %llu to running list\n", udev_device_get_seqnum(loop_event->dev));
 441
 442                 /* retry if events finished in the meantime */
 443                 if (sigchilds_waiting) {
 444                         sigchilds_waiting = 0;
 445                         reap_sigchilds();
 446                         goto start_over;
 447                 }
 448         }
 449 }
 450
 451 /* receive the udevd message from userspace */
 452 static void handle_ctrl_msg(struct udev_ctrl *uctrl)
 453 {
 454         struct udev *udev = udev_ctrl_get_udev(uctrl);
 455         struct udev_ctrl_msg *ctrl_msg;
 456         const char *str;
 457         int i;
 458
 459         ctrl_msg = udev_ctrl_receive_msg(uctrl);
 460         if (ctrl_msg == NULL)
 461                 return;
 462
 463         i = udev_ctrl_get_set_log_level(ctrl_msg);
 464         if (i >= 0) {
 465                 info(udev, "udevd message (SET_LOG_PRIORITY) received, log_priority=%i\n", i);
 466                 udev_set_log_priority(udev, i);
 467         }
 468
 469         if (udev_ctrl_get_stop_exec_queue(ctrl_msg) > 0) {
 470                 info(udev, "udevd message (STOP_EXEC_QUEUE) received\n");
 471                 stop_exec_q = 1;
 472         }
 473
 474         if (udev_ctrl_get_start_exec_queue(ctrl_msg) > 0) {
 475                 info(udev, "udevd message (START_EXEC_QUEUE) received\n");
 476                 stop_exec_q = 0;
 477                 event_queue_manager(udev);
 478         }
 479
 480         if (udev_ctrl_get_reload_rules(ctrl_msg) > 0) {
 481                 info(udev, "udevd message (RELOAD_RULES) received\n");
 482                 reload_config = 1;
 483         }
 484
 485         str = udev_ctrl_get_set_env(ctrl_msg);
 486         if (str != NULL) {
 487                 char *key;
 488
 489                 key = strdup(str);
 490                 if (key != NULL) {
 491                         char *val;
 492
 493                         val = strchr(key, '=');
 494                         if (val != NULL) {
 495                                 val[0] = '\0';
 496                                 val = &val[1];
 497                                 if (val[0] == '\0') {
 498                                         info(udev, "udevd message (ENV) received, unset '%s'\n", key);
 499                                         udev_add_property(udev, key, NULL);
 500                                 } else {
 501                                         info(udev, "udevd message (ENV) received, set '%s=%s'\n", key, val);
 502                                         udev_add_property(udev, key, val);
 503                                 }
 504                         } else {
 505                                 err(udev, "wrong key format '%s'\n", key);
 506                         }
 507                         free(key);
 508                 }
 509         }
 510
 511         i = udev_ctrl_get_set_max_childs(ctrl_msg);
 512         if (i >= 0) {
 513                 info(udev, "udevd message (SET_MAX_CHILDS) received, max_childs=%i\n", i);
 514                 max_childs = i;
 515         }
 516         udev_ctrl_msg_unref(ctrl_msg);
 517 }
 518
 519 /* read inotify messages */
 520 static int handle_inotify(struct udev *udev)
 521 {
 522         int nbytes, pos;
 523         char *buf;
 524         struct inotify_event *ev;
 525
 526         if ((ioctl(inotify_fd, FIONREAD, &nbytes) < 0) || (nbytes <= 0))
 527                 return 0;
 528
 529         buf = malloc(nbytes);
 530         if (buf == NULL) {
 531                 err(udev, "error getting buffer for inotify, disable watching\n");
 532                 close(inotify_fd);
 533                 inotify_fd = -1;
 534                 return 0;
 535         }
 536
 537         read(inotify_fd, buf, nbytes);
 538
 539         for (pos = 0; pos < nbytes; pos += sizeof(struct inotify_event) + ev->len) {
 540                 struct udev_device *dev;
 541
 542                 ev = (struct inotify_event *)(buf + pos);
 543                 if (ev->len) {
 544                         dbg(udev, "inotify event: %x for %s\n", ev->mask, ev->name);
 545                         reload_config = 1;
 546                         continue;
 547                 }
 548
 549                 dev = udev_watch_lookup(udev, ev->wd);
 550                 if (dev != NULL) {
 551                         dbg(udev, "inotify event: %x for %s\n", ev->mask, udev_device_get_devnode(dev));
 552                         if (ev->mask & IN_CLOSE_WRITE) {
 553                                 char filename[UTIL_PATH_SIZE];
 554                                 int fd;
 555
 556                                 info(udev, "device %s closed, synthesising 'change'\n", udev_device_get_devnode(dev));
 557                                 util_strlcpy(filename, udev_device_get_syspath(dev), sizeof(filename));
 558                                 util_strlcat(filename, "/uevent", sizeof(filename));
 559                                 fd = open(filename, O_WRONLY);
 560                                 if (fd < 0 || write(fd, "change", 6) < 0)
 561                                         info(udev, "error writing uevent: %m\n");
 562                                 close(fd);
 563                         }
 564                         if (ev->mask & IN_IGNORED)
 565                                 udev_watch_end(udev, dev);
 566
 567                         udev_device_unref(dev);
 568                 }
 569
 570         }
 571
 572         free (buf);
 573         return 0;
 574 }
 575
 576 static void asmlinkage sig_handler(int signum)
 577 {
 578         switch (signum) {
 579                 case SIGINT:
 580                 case SIGTERM:
 581                         udev_exit = 1;
 582                         break;
 583                 case SIGCHLD:
 584                         /* set flag, then write to pipe if needed */
 585                         sigchilds_waiting = 1;
 586                         break;
 587                 case SIGHUP:
 588                         reload_config = 1;
 589                         break;
 590         }
 591
 592         signal_received = 1;
 593 }
 594
 595 static void udev_done(int pid, int exitstatus)
 596 {
 597         struct udev_list_node *loop;
 598
 599         /* find event associated with pid and delete it */
 600         udev_list_node_foreach(loop, &event_list) {
 601                 struct udev_event *loop_event = node_to_event(loop);
 602
 603                 if (loop_event->pid == pid) {
 604                         info(loop_event->udev, "seq %llu cleanup, pid [%d], status %i, %ld seconds old\n",
 605                              udev_device_get_seqnum(loop_event->dev), loop_event->pid,
 606                              exitstatus, time(NULL) - loop_event->queue_time);
 607                         loop_event->exitstatus = exitstatus;
 608                         if (debug_trace)
 609                                 fprintf(stderr, "exit %s (%llu)\n",
 610                                        udev_device_get_syspath(loop_event->dev),
 611                                        udev_device_get_seqnum(loop_event->dev));
 612                         event_queue_delete(loop_event);
 613                         childs--;
 614
 615                         /* there may be dependent events waiting */
 616                         run_exec_q = 1;
 617                         return;
 618                 }
 619         }
 620 }
 621
 622 static void reap_sigchilds(void)
 623 {
 624         pid_t pid;
 625         int status;
 626
 627         while (1) {
 628                 pid = waitpid(-1, &status, WNOHANG);
 629                 if (pid <= 0)
 630                         break;
 631                 if (WIFEXITED(status))
 632                         status = WEXITSTATUS(status);
 633                 else if (WIFSIGNALED(status))
 634                         status = WTERMSIG(status) + 128;
 635                 else
 636                         status = 0;
 637                 udev_done(pid, status);
 638         }
 639 }
 640
 641 static void cleanup_queue_dir(struct udev *udev)
 642 {
 643         char dirname[UTIL_PATH_SIZE];
 644         char filename[UTIL_PATH_SIZE];
 645         DIR *dir;
 646
 647         util_strlcpy(filename, udev_get_dev_path(udev), sizeof(filename));
 648         util_strlcat(filename, "/.udev/uevent_seqnum", sizeof(filename));
 649         unlink(filename);
 650
 651         util_strlcpy(dirname, udev_get_dev_path(udev), sizeof(dirname));
 652         util_strlcat(dirname, "/.udev/queue", sizeof(dirname));
 653         dir = opendir(dirname);
 654         if (dir != NULL) {
 655                 while (1) {
 656                         struct dirent *dent;
 657
 658                         dent = readdir(dir);
 659                         if (dent == NULL || dent->d_name[0] == '\0')
 660                                 break;
 661                         if (dent->d_name[0] == '.')
 662                                 continue;
 663                         util_strlcpy(filename, dirname, sizeof(filename));
 664                         util_strlcat(filename, "/", sizeof(filename));
 665                         util_strlcat(filename, dent->d_name, sizeof(filename));
 666                         unlink(filename);
 667                 }
 668                 closedir(dir);
 669                 rmdir(dirname);
 670         }
 671 }
 672
 673 static void export_initial_seqnum(struct udev *udev)
 674 {
 675         char filename[UTIL_PATH_SIZE];
 676         int fd;
 677         char seqnum[32];
 678         ssize_t len = 0;
 679
 680         util_strlcpy(filename, udev_get_sys_path(udev), sizeof(filename));
 681         util_strlcat(filename, "/kernel/uevent_seqnum", sizeof(filename));
 682         fd = open(filename, O_RDONLY);
 683         if (fd >= 0) {
 684                 len = read(fd, seqnum, sizeof(seqnum)-1);
 685                 close(fd);
 686         }
 687         if (len <= 0) {
 688                 strcpy(seqnum, "0\n");
 689                 len = 3;
 690         }
 691         util_strlcpy(filename, udev_get_dev_path(udev), sizeof(filename));
 692         util_strlcat(filename, "/.udev/uevent_seqnum", sizeof(filename));
 693         util_create_path(udev, filename);
 694         fd = open(filename, O_WRONLY|O_TRUNC|O_CREAT, 0644);
 695         if (fd >= 0) {
 696                 write(fd, seqnum, len);
 697                 close(fd);
 698         }
 699 }
 700
 701 int main(int argc, char *argv[])
 702 {
 703         struct udev *udev;
 704         int fd;
 705         struct sigaction act;
 706         const char *value;
 707         int daemonize = 0;
 708         int resolve_names = 1;
 709         static const struct option options[] = {
 710                 { "daemon", no_argument, NULL, 'd' },
 711                 { "debug-trace", no_argument, NULL, 't' },
 712                 { "debug", no_argument, NULL, 'D' },
 713                 { "help", no_argument, NULL, 'h' },
 714                 { "version", no_argument, NULL, 'V' },
 715                 { "resolve-names", required_argument, NULL, 'N' },
 716                 {}
 717         };
 718         int rc = 1;
 719
 720         udev = udev_new();
 721         if (udev == NULL)
 722                 goto exit;
 723
 724         logging_init("udevd");
 725         udev_set_log_fn(udev, log_fn);
 726         info(udev, "version %s\n", VERSION);
 727         udev_selinux_init(udev);
 728
 729         while (1) {
 730                 int option;
 731
 732                 option = getopt_long(argc, argv, "dDthV", options, NULL);
 733                 if (option == -1)
 734                         break;
 735
 736                 switch (option) {
 737                 case 'd':
 738                         daemonize = 1;
 739                         break;
 740                 case 't':
 741                         debug_trace = 1;
 742                         break;
 743                 case 'D':
 744                         debug = 1;
 745                         if (udev_get_log_priority(udev) < LOG_INFO)
 746                                 udev_set_log_priority(udev, LOG_INFO);
 747                         break;
 748                 case 'N':
 749                         if (strcmp (optarg, "early") == 0) {
 750                                 resolve_names = 1;
 751                         } else if (strcmp (optarg, "late") == 0) {
 752                                 resolve_names = 0;
 753                         } else if (strcmp (optarg, "never") == 0) {
 754                                 resolve_names = -1;
 755                         } else {
 756                                 fprintf(stderr, "resolve-names must be early, late or never\n");
 757                                 err(udev, "resolve-names must be early, late or never\n");
 758                                 goto exit;
 759                         }
 760                         break;
 761                 case 'h':
 762                         printf("Usage: udevd [--help] [--daemon] [--debug-trace] [--debug] "
 763                                "[--resolve-names=early|late|never] [--version]\n");
 764                         goto exit;
 765                 case 'V':
 766                         printf("%s\n", VERSION);
 767                         goto exit;
 768                 default:
 769                         goto exit;
 770                 }
 771         }
 772
 773         if (getuid() != 0) {
 774                 fprintf(stderr, "root privileges required\n");
 775                 err(udev, "root privileges required\n");
 776                 goto exit;
 777         }
 778
 779         /* make sure std{in,out,err} fd's are in a sane state */
 780         fd = open("/dev/null", O_RDWR);
 781         if (fd < 0) {
 782                 fprintf(stderr, "cannot open /dev/null\n");
 783                 err(udev, "cannot open /dev/null\n");
 784         }
 785         if (write(STDOUT_FILENO, 0, 0) < 0)
 786                 dup2(fd, STDOUT_FILENO);
 787         if (write(STDERR_FILENO, 0, 0) < 0)
 788                 dup2(fd, STDERR_FILENO);
 789
 790         /* init control socket, bind() ensures, that only one udevd instance is running */
 791         udev_ctrl = udev_ctrl_new_from_socket(udev, UDEV_CTRL_SOCK_PATH);
 792         if (udev_ctrl == NULL) {
 793                 fprintf(stderr, "error initializing control socket");
 794                 err(udev, "error initializing udevd socket");
 795                 rc = 1;
 796                 goto exit;
 797         }
 798
 799         if (udev_ctrl_enable_receiving(udev_ctrl) < 0) {
 800                 fprintf(stderr, "error binding control socket, seems udevd is already running\n");
 801                 err(udev, "error binding control socket, seems udevd is already running\n");
 802                 rc = 1;
 803                 goto exit;
 804         }
 805
 806         kernel_monitor = udev_monitor_new_from_netlink(udev);
 807         if (kernel_monitor == NULL || udev_monitor_enable_receiving(kernel_monitor) < 0) {
 808                 fprintf(stderr, "error initializing netlink socket\n");
 809                 err(udev, "error initializing netlink socket\n");
 810                 rc = 3;
 811                 goto exit;
 812         }
 813         udev_monitor_set_receive_buffer_size(kernel_monitor, 128*1024*1024);
 814
 815         rules = udev_rules_new(udev, resolve_names);
 816         if (rules == NULL) {
 817                 err(udev, "error reading rules\n");
 818                 goto exit;
 819         }
 820         udev_list_init(&event_list);
 821         cleanup_queue_dir(udev);
 822         export_initial_seqnum(udev);
 823
 824         if (daemonize) {
 825                 pid_t pid;
 826
 827                 pid = fork();
 828                 switch (pid) {
 829                 case 0:
 830                         dbg(udev, "daemonized fork running\n");
 831                         break;
 832                 case -1:
 833                         err(udev, "fork of daemon failed: %m\n");
 834                         rc = 4;
 835                         goto exit;
 836                 default:
 837                         dbg(udev, "child [%u] running, parent exits\n", pid);
 838                         rc = 0;
 839                         goto exit;
 840                 }
 841         }
 842
 843         /* redirect std{out,err} */
 844         if (!debug && !debug_trace) {
 845                 dup2(fd, STDIN_FILENO);
 846                 dup2(fd, STDOUT_FILENO);
 847                 dup2(fd, STDERR_FILENO);
 848         }
 849         if (fd > STDERR_FILENO)
 850                 close(fd);
 851
 852         /* set scheduling priority for the daemon */
 853         setpriority(PRIO_PROCESS, 0, UDEVD_PRIORITY);
 854
 855         chdir("/");
 856         umask(022);
 857         setsid();
 858
 859         /* OOM_DISABLE == -17 */
 860         fd = open("/proc/self/oom_adj", O_RDWR);
 861         if (fd < 0)
 862                 err(udev, "error disabling OOM: %m\n");
 863         else {
 864                 write(fd, "-17", 3);
 865                 close(fd);
 866         }
 867
 868         fd = open("/dev/kmsg", O_WRONLY);
 869         if (fd > 0) {
 870                 const char *ver_str = "<6>udev: starting version " VERSION "\n";
 871                 char path[UTIL_PATH_SIZE];
 872                 struct stat statbuf;
 873
 874                 write(fd, ver_str, strlen(ver_str));
 875                 util_strlcpy(path, udev_get_sys_path(udev), sizeof(path));
 876                 util_strlcat(path, "/class/mem/null", sizeof(path));
 877                 if (lstat(path, &statbuf) == 0) {
 878                         if (S_ISDIR(statbuf.st_mode)) {
 879                                 const char *depr_str =
 880                                         "<6>udev: deprecated sysfs layout; update the kernel or "
 881                                         "disable CONFIG_SYSFS_DEPRECATED; some udev features will "
 882                                         "not work correctly\n";
 883
 884                                 write(fd, depr_str, strlen(depr_str));
 885                         }
 886                 }
 887                 close(fd);
 888         }
 889
 890         /* set signal handlers */
 891         memset(&act, 0x00, sizeof(struct sigaction));
 892         act.sa_handler = (void (*)(int)) sig_handler;
 893         sigemptyset(&act.sa_mask);
 894         act.sa_flags = SA_RESTART;
 895         sigaction(SIGINT, &act, NULL);
 896         sigaction(SIGTERM, &act, NULL);
 897         sigaction(SIGCHLD, &act, NULL);
 898         sigaction(SIGHUP, &act, NULL);
 899
 900         /* watch rules directory */
 901         udev_watch_init(udev);
 902         if (inotify_fd >= 0) {
 903                 if (udev_get_rules_path(udev) != NULL) {
 904                         inotify_add_watch(inotify_fd, udev_get_rules_path(udev),
 905                                           IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
 906                 } else {
 907                         char filename[UTIL_PATH_SIZE];
 908
 909                         inotify_add_watch(inotify_fd, UDEV_PREFIX "/lib/udev/rules.d",
 910                                           IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
 911                         inotify_add_watch(inotify_fd, SYSCONFDIR "/udev/rules.d",
 912                                           IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
 913
 914                         /* watch dynamic rules directory */
 915                         util_strlcpy(filename, udev_get_dev_path(udev), sizeof(filename));
 916                         util_strlcat(filename, "/.udev/rules.d", sizeof(filename));
 917                         inotify_add_watch(inotify_fd, filename,
 918                                           IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
 919                 }
 920
 921                 udev_watch_restore(udev);
 922         }
 923
 924         /* in trace mode run one event after the other */
 925         if (debug_trace) {
 926                 max_childs = 1;
 927         } else {
 928                 int memsize = mem_size_mb();
 929                 if (memsize > 0)
 930                         max_childs = 128 + (memsize / 4);
 931                 else
 932                         max_childs = UDEVD_MAX_CHILDS;
 933         }
 934         /* possibly overwrite maximum limit of executed events */
 935         value = getenv("UDEVD_MAX_CHILDS");
 936         if (value)
 937                 max_childs = strtoul(value, NULL, 10);
 938         info(udev, "initialize max_childs to %u\n", max_childs);
 939
 940         while (!udev_exit) {
 941                 sigset_t blocked_mask, orig_mask;
 942                 struct pollfd pfd[4];
 943                 struct pollfd *ctrl_poll, *monitor_poll, *inotify_poll = NULL;
 944                 int nfds = 0;
 945                 int fdcount;
 946
 947                 sigfillset(&blocked_mask);
 948                 sigprocmask(SIG_SETMASK, &blocked_mask, &orig_mask);
 949                 if (signal_received) {
 950                         sigprocmask(SIG_SETMASK, &orig_mask, NULL);
 951                         goto handle_signals;
 952                 }
 953
 954                 ctrl_poll = &pfd[nfds++];
 955                 ctrl_poll->fd = udev_ctrl_get_fd(udev_ctrl);
 956                 ctrl_poll->events = POLLIN;
 957
 958                 monitor_poll = &pfd[nfds++];
 959                 monitor_poll->fd = udev_monitor_get_fd(kernel_monitor);
 960                 monitor_poll->events = POLLIN;
 961
 962                 if (inotify_fd >= 0) {
 963                         inotify_poll = &pfd[nfds++];
 964                         inotify_poll->fd = inotify_fd;
 965                         inotify_poll->events = POLLIN;
 966                 }
 967
 968                 fdcount = ppoll(pfd, nfds, NULL, &orig_mask);
 969                 sigprocmask(SIG_SETMASK, &orig_mask, NULL);
 970                 if (fdcount < 0) {
 971                         if (errno == EINTR)
 972                                 goto handle_signals;
 973                         err(udev, "error in select: %m\n");
 974                         continue;
 975                 }
 976
 977                 /* get control message */
 978                 if (ctrl_poll->revents & POLLIN)
 979                         handle_ctrl_msg(udev_ctrl);
 980
 981                 /* get kernel uevent */
 982                 if (monitor_poll->revents & POLLIN) {
 983                         struct udev_device *dev;
 984
 985                         dev = udev_monitor_receive_device(kernel_monitor);
 986                         if (dev != NULL) {
 987                                 struct udev_event *event;
 988
 989                                 event = udev_event_new(dev);
 990                                 if (event != NULL)
 991                                         event_queue_insert(event);
 992                                 else
 993                                         udev_device_unref(dev);
 994                         }
 995                 }
 996
 997                 /* rules directory inotify watch */
 998                 if (inotify_poll && (inotify_poll->revents & POLLIN))
 999                         handle_inotify(udev);
1000
1001 handle_signals:
1002                 signal_received = 0;
1003
1004                 /* rules changed, set by inotify or a HUP signal */
1005                 if (reload_config) {
1006                         struct udev_rules *rules_new;
1007
1008                         reload_config = 0;
1009                         rules_new = udev_rules_new(udev, resolve_names);
1010                         if (rules_new != NULL) {
1011                                 udev_rules_unref(rules);
1012                                 rules = rules_new;
1013                         }
1014                 }
1015
1016                 if (sigchilds_waiting) {
1017                         sigchilds_waiting = 0;
1018                         reap_sigchilds();
1019                 }
1020
1021                 if (run_exec_q) {
1022                         run_exec_q = 0;
1023                         if (!stop_exec_q)
1024                                 event_queue_manager(udev);
1025                 }
1026         }
1027         cleanup_queue_dir(udev);
1028         rc = 0;
1029 exit:
1030         udev_rules_unref(rules);
1031         udev_ctrl_unref(udev_ctrl);
1032         if (inotify_fd >= 0)
1033                 close(inotify_fd);
1034         udev_monitor_unref(kernel_monitor);
1035         udev_selinux_exit(udev);
1036         udev_unref(udev);
1037         logging_close();
1038         return rc;
1039 }