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  * Copyright (C) 2009 Canonical Ltd.
   5  * Copyright (C) 2009 Scott James Remnant <scott@netsplit.com>
   6  *
   7  * This program is free software: you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation, either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21 #include <stddef.h>
  22 #include <signal.h>
  23 #include <unistd.h>
  24 #include <errno.h>
  25 #include <stdio.h>
  26 #include <stdlib.h>
  27 #include <string.h>
  28 #include <ctype.h>
  29 #include <fcntl.h>
  30 #include <time.h>
  31 #include <getopt.h>
  32 #include <dirent.h>
  33 #include <sys/select.h>
  34 #include <sys/poll.h>
  35 #include <sys/wait.h>
  36 #include <sys/stat.h>
  37 #include <sys/ioctl.h>
  38 #ifdef HAVE_INOTIFY
  39 #include <sys/inotify.h>
  40 #endif
  41
  42 #include "udev.h"
  43
  44 #define UDEVD_PRIORITY                  -4
  45 #define UDEV_PRIORITY                   -2
  46
  47 /* maximum limit of forked childs */
  48 #define UDEVD_MAX_CHILDS                256
  49
  50 static int debug;
  51
  52 static void log_fn(struct udev *udev, int priority,
  53                    const char *file, int line, const char *fn,
  54                    const char *format, va_list args)
  55 {
  56         if (debug) {
  57                 fprintf(stderr, "[%d] %s: ", (int) getpid(), fn);
  58                 vfprintf(stderr, format, args);
  59         } else {
  60                 vsyslog(priority, format, args);
  61         }
  62 }
  63
  64 static void reap_sigchilds(void);
  65
  66 static int debug_trace;
  67 static struct udev_rules *rules;
  68 static struct udev_ctrl *udev_ctrl;
  69 static struct udev_monitor *kernel_monitor;
  70 static volatile sig_atomic_t sigchilds_waiting;
  71 static volatile sig_atomic_t udev_exit;
  72 static volatile sig_atomic_t reload_config;
  73 static volatile sig_atomic_t signal_received;
  74 static volatile pid_t settle_pid;
  75 static int run_exec_q;
  76 static int stop_exec_q;
  77 static int max_childs;
  78 static int childs;
  79 static struct udev_list_node event_list;
  80
  81 enum event_state {
  82         EVENT_QUEUED,
  83         EVENT_FINISHED,
  84         EVENT_FAILED,
  85 };
  86
  87 static struct udev_event *node_to_event(struct udev_list_node *node)
  88 {
  89         char *event;
  90
  91         event = (char *)node;
  92         event -= offsetof(struct udev_event, node);
  93         return (struct udev_event *)event;
  94 }
  95
  96 static void export_event_state(struct udev_event *event, enum event_state state)
  97 {
  98         char filename[UTIL_PATH_SIZE];
  99         char filename_failed[UTIL_PATH_SIZE];
 100         size_t start;
 101
 102         /* location of queue file */
 103         snprintf(filename, sizeof(filename), "%s/.udev/queue/%llu",
 104                  udev_get_dev_path(event->udev), udev_device_get_seqnum(event->dev));
 105
 106         /* location of failed file */
 107         util_strlcpy(filename_failed, udev_get_dev_path(event->udev), sizeof(filename_failed));
 108         util_strlcat(filename_failed, "/", sizeof(filename_failed));
 109         start = util_strlcat(filename_failed, ".udev/failed/", sizeof(filename_failed));
 110         util_strlcat(filename_failed, udev_device_get_devpath(event->dev), sizeof(filename_failed));
 111         util_path_encode(&filename_failed[start], sizeof(filename_failed) - start);
 112
 113         switch (state) {
 114         case EVENT_QUEUED:
 115                 if(unlink(filename_failed) == 0)
 116                         util_delete_path(event->udev, filename_failed);
 117                 util_create_path(event->udev, filename);
 118                 udev_selinux_setfscreatecon(event->udev, filename, S_IFLNK);
 119                 symlink(udev_device_get_devpath(event->dev), filename);
 120                 udev_selinux_resetfscreatecon(event->udev);
 121                 break;
 122         case EVENT_FINISHED:
 123                 if (udev_device_get_devpath_old(event->dev) != NULL) {
 124                         /* "move" event - rename failed file to current name, do not delete failed */
 125                         char filename_failed_old[UTIL_PATH_SIZE];
 126
 127                         util_strlcpy(filename_failed_old, udev_get_dev_path(event->udev), sizeof(filename_failed_old));
 128                         util_strlcat(filename_failed_old, "/", sizeof(filename_failed_old));
 129                         start = util_strlcat(filename_failed_old, ".udev/failed/", sizeof(filename_failed_old));
 130                         util_strlcat(filename_failed_old, udev_device_get_devpath_old(event->dev), sizeof(filename_failed_old));
 131                         util_path_encode(&filename_failed_old[start], sizeof(filename) - start);
 132
 133                         if (rename(filename_failed_old, filename_failed) == 0)
 134                                 info(event->udev, "renamed devpath, moved failed state of '%s' to %s'\n",
 135                                      udev_device_get_devpath_old(event->dev), udev_device_get_devpath(event->dev));
 136                 } else {
 137                         if (unlink(filename_failed) == 0)
 138                                 util_delete_path(event->udev, filename_failed);
 139                 }
 140
 141                 unlink(filename);
 142
 143                 /* clean up possibly empty queue directory */
 144                 if (udev_list_is_empty(&event_list))
 145                         util_delete_path(event->udev, filename);
 146                 break;
 147         case EVENT_FAILED:
 148                 /* move failed event to the failed directory */
 149                 util_create_path(event->udev, filename_failed);
 150                 rename(filename, filename_failed);
 151
 152                 /* clean up possibly empty queue directory */
 153                 if (udev_list_is_empty(&event_list))
 154                         util_delete_path(event->udev, filename);
 155                 break;
 156         }
 157
 158         return;
 159 }
 160
 161 static void event_queue_delete(struct udev_event *event)
 162 {
 163         udev_list_node_remove(&event->node);
 164
 165         /* mark as failed, if "add" event returns non-zero */
 166         if (event->exitstatus && strcmp(udev_device_get_action(event->dev), "add") == 0)
 167                 export_event_state(event, EVENT_FAILED);
 168         else
 169                 export_event_state(event, EVENT_FINISHED);
 170
 171         udev_device_unref(event->dev);
 172         udev_event_unref(event);
 173 }
 174
 175 static void event_sig_handler(int signum)
 176 {
 177         if (signum == SIGALRM)
 178                 _exit(1);
 179 }
 180
 181 static void event_fork(struct udev_event *event)
 182 {
 183         pid_t pid;
 184         struct sigaction act;
 185         int err;
 186
 187         if (debug_trace) {
 188                 event->trace = 1;
 189                 fprintf(stderr, "fork %s (%llu)\n",
 190                        udev_device_get_syspath(event->dev),
 191                        udev_device_get_seqnum(event->dev));
 192         }
 193
 194         pid = fork();
 195         switch (pid) {
 196         case 0:
 197                 /* child */
 198                 udev_ctrl_unref(udev_ctrl);
 199                 logging_close();
 200                 logging_init("udevd-event");
 201                 setpriority(PRIO_PROCESS, 0, UDEV_PRIORITY);
 202
 203                 /* set signal handlers */
 204                 memset(&act, 0x00, sizeof(act));
 205                 act.sa_handler = event_sig_handler;
 206                 sigemptyset (&act.sa_mask);
 207                 act.sa_flags = 0;
 208                 sigaction(SIGALRM, &act, NULL);
 209
 210                 /* reset to default */
 211                 act.sa_handler = SIG_DFL;
 212                 sigaction(SIGINT, &act, NULL);
 213                 sigaction(SIGTERM, &act, NULL);
 214                 sigaction(SIGCHLD, &act, NULL);
 215                 sigaction(SIGHUP, &act, NULL);
 216
 217                 /* set timeout to prevent hanging processes */
 218                 alarm(UDEV_EVENT_TIMEOUT);
 219
 220                 /* apply rules, create node, symlinks */
 221                 err = udev_event_execute_rules(event, rules);
 222
 223                 /* rules may change/disable the timeout */
 224                 if (udev_device_get_event_timeout(event->dev) >= 0)
 225                         alarm(udev_device_get_event_timeout(event->dev));
 226
 227                 /* execute RUN= */
 228                 if (err == 0 && !event->ignore_device && udev_get_run(event->udev))
 229                         udev_event_execute_run(event);
 230
 231                 /* apply/restore inotify watch */
 232                 if (err == 0 && event->inotify_watch) {
 233                         udev_watch_begin(event->udev, event->dev);
 234                         udev_device_update_db(event->dev);
 235                 }
 236
 237                 /* send processed event back to the kernel netlink socket */
 238                 udev_monitor_send_device(kernel_monitor, event->dev);
 239
 240                 info(event->udev, "seq %llu exit with %i\n", udev_device_get_seqnum(event->dev), err);
 241                 logging_close();
 242                 if (err != 0)
 243                         exit(1);
 244                 exit(0);
 245         case -1:
 246                 err(event->udev, "fork of child failed: %m\n");
 247                 event_queue_delete(event);
 248                 break;
 249         default:
 250                 /* get SIGCHLD in main loop */
 251                 info(event->udev, "seq %llu forked, pid [%d], '%s' '%s', %ld seconds old\n",
 252                      udev_device_get_seqnum(event->dev),
 253                      pid,
 254                      udev_device_get_action(event->dev),
 255                      udev_device_get_subsystem(event->dev),
 256                      time(NULL) - event->queue_time);
 257                 event->pid = pid;
 258                 childs++;
 259         }
 260 }
 261
 262 static void event_queue_insert(struct udev_event *event)
 263 {
 264         char filename[UTIL_PATH_SIZE];
 265         int fd;
 266
 267         event->queue_time = time(NULL);
 268
 269         export_event_state(event, EVENT_QUEUED);
 270         info(event->udev, "seq %llu queued, '%s' '%s'\n", udev_device_get_seqnum(event->dev),
 271              udev_device_get_action(event->dev), udev_device_get_subsystem(event->dev));
 272
 273         util_strlcpy(filename, udev_get_dev_path(event->udev), sizeof(filename));
 274         util_strlcat(filename, "/.udev/uevent_seqnum", sizeof(filename));
 275         fd = open(filename, O_WRONLY|O_TRUNC|O_CREAT, 0644);
 276         if (fd >= 0) {
 277                 char str[32];
 278                 int len;
 279
 280                 len = sprintf(str, "%llu\n", udev_device_get_seqnum(event->dev));
 281                 write(fd, str, len);
 282                 close(fd);
 283         }
 284
 285
 286         udev_list_node_append(&event->node, &event_list);
 287         run_exec_q = 1;
 288
 289         /* run all events with a timeout set immediately */
 290         if (udev_device_get_timeout(event->dev) > 0) {
 291                 event_fork(event);
 292                 return;
 293         }
 294 }
 295
 296 static int mem_size_mb(void)
 297 {
 298         FILE *f;
 299         char buf[4096];
 300         long int memsize = -1;
 301
 302         f = fopen("/proc/meminfo", "r");
 303         if (f == NULL)
 304                 return -1;
 305
 306         while (fgets(buf, sizeof(buf), f) != NULL) {
 307                 long int value;
 308
 309                 if (sscanf(buf, "MemTotal: %ld kB", &value) == 1) {
 310                         memsize = value / 1024;
 311                         break;
 312                 }
 313         }
 314
 315         fclose(f);
 316         return memsize;
 317 }
 318
 319 static int compare_devpath(const char *running, const char *waiting)
 320 {
 321         int i = 0;
 322
 323         while (running[i] != '\0' && running[i] == waiting[i])
 324                 i++;
 325
 326         /* identical device event found */
 327         if (running[i] == '\0' && waiting[i] == '\0')
 328                 return 1;
 329
 330         /* parent device event found */
 331         if (running[i] == '\0' && waiting[i] == '/')
 332                 return 2;
 333
 334         /* child device event found */
 335         if (running[i] == '/' && waiting[i] == '\0')
 336                 return 3;
 337
 338         /* no matching event */
 339         return 0;
 340 }
 341
 342 /* lookup event for identical, parent, child device */
 343 static int devpath_busy(struct udev_event *event)
 344 {
 345         struct udev_list_node *loop;
 346
 347         if (event->delaying_seqnum > 0) {
 348         }
 349         /* check if queue contains events we depend on */
 350         udev_list_node_foreach(loop, &event_list) {
 351                 struct udev_event *loop_event = node_to_event(loop);
 352
 353                 /* we already found a later event, earlier can not block us, no need to check again */
 354                 if (udev_device_get_seqnum(loop_event->dev) < event->delaying_seqnum)
 355                         continue;
 356
 357                 /* event we checked earlier still exists, no need to check again */
 358                 if (udev_device_get_seqnum(loop_event->dev) == event->delaying_seqnum)
 359                         return 2;
 360
 361                 /* found ourself, no later event can block us */
 362                 if (udev_device_get_seqnum(loop_event->dev) >= udev_device_get_seqnum(event->dev))
 363                         break;
 364
 365                 /* check our old name */
 366                 if (udev_device_get_devpath_old(event->dev) != NULL)
 367                         if (strcmp(udev_device_get_devpath(loop_event->dev), udev_device_get_devpath_old(event->dev)) == 0) {
 368                                 event->delaying_seqnum = udev_device_get_seqnum(loop_event->dev);
 369                                 return 3;
 370                         }
 371
 372                 /* check identical, parent, or child device event */
 373                 if (compare_devpath(udev_device_get_devpath(loop_event->dev), udev_device_get_devpath(event->dev)) != 0) {
 374                         dbg(event->udev, "%llu, device event still pending %llu (%s)\n",
 375                             udev_device_get_seqnum(event->dev),
 376                             udev_device_get_seqnum(loop_event->dev),
 377                             udev_device_get_devpath(loop_event->dev));
 378                         event->delaying_seqnum = udev_device_get_seqnum(loop_event->dev);
 379                         return 4;
 380                 }
 381
 382                 /* check for our major:minor number */
 383                 if (major(udev_device_get_devnum(event->dev)) > 0 &&
 384                     udev_device_get_devnum(loop_event->dev) == udev_device_get_devnum(event->dev) &&
 385                     strcmp(udev_device_get_subsystem(event->dev), udev_device_get_subsystem(loop_event->dev)) == 0) {
 386                         dbg(event->udev, "%llu, device event still pending %llu (%d:%d)\n",
 387                             udev_device_get_seqnum(event->dev),
 388                             udev_device_get_seqnum(loop_event->dev),
 389                             major(udev_device_get_devnum(loop_event->dev)), minor(udev_device_get_devnum(loop_event->dev)));
 390                         event->delaying_seqnum = udev_device_get_seqnum(loop_event->dev);
 391                         return 5;
 392                 }
 393         }
 394         return 0;
 395 }
 396
 397 /* serializes events for the identical and parent and child devices */
 398 static void event_queue_manager(struct udev *udev)
 399 {
 400         struct udev_list_node *loop;
 401         struct udev_list_node *tmp;
 402
 403 start_over:
 404         if (udev_list_is_empty(&event_list)) {
 405                 if (childs > 0) {
 406                         err(udev, "event list empty, but childs count is %i", childs);
 407                         childs = 0;
 408                 }
 409                 return;
 410         }
 411
 412         udev_list_node_foreach_safe(loop, tmp, &event_list) {
 413                 struct udev_event *loop_event = node_to_event(loop);
 414
 415                 if (childs >= max_childs) {
 416                         info(udev, "maximum number (%i) of childs reached\n", childs);
 417                         break;
 418                 }
 419
 420                 if (loop_event->pid != 0)
 421                         continue;
 422
 423                 /* do not start event if parent or child event is still running */
 424                 if (devpath_busy(loop_event) != 0) {
 425                         dbg(udev, "delay seq %llu (%s)\n",
 426                             udev_device_get_seqnum(loop_event->dev),
 427                             udev_device_get_devpath(loop_event->dev));
 428                         continue;
 429                 }
 430
 431                 event_fork(loop_event);
 432                 dbg(udev, "moved seq %llu to running list\n", udev_device_get_seqnum(loop_event->dev));
 433
 434                 /* retry if events finished in the meantime */
 435                 if (sigchilds_waiting) {
 436                         sigchilds_waiting = 0;
 437                         reap_sigchilds();
 438                         goto start_over;
 439                 }
 440         }
 441 }
 442
 443 /* receive the udevd message from userspace */
 444 static void handle_ctrl_msg(struct udev_ctrl *uctrl)
 445 {
 446         struct udev *udev = udev_ctrl_get_udev(uctrl);
 447         struct udev_ctrl_msg *ctrl_msg;
 448         const char *str;
 449         int i;
 450
 451         ctrl_msg = udev_ctrl_receive_msg(uctrl);
 452         if (ctrl_msg == NULL)
 453                 return;
 454
 455         i = udev_ctrl_get_set_log_level(ctrl_msg);
 456         if (i >= 0) {
 457                 info(udev, "udevd message (SET_LOG_PRIORITY) received, log_priority=%i\n", i);
 458                 udev_set_log_priority(udev, i);
 459         }
 460
 461         if (udev_ctrl_get_stop_exec_queue(ctrl_msg) > 0) {
 462                 info(udev, "udevd message (STOP_EXEC_QUEUE) received\n");
 463                 stop_exec_q = 1;
 464         }
 465
 466         if (udev_ctrl_get_start_exec_queue(ctrl_msg) > 0) {
 467                 info(udev, "udevd message (START_EXEC_QUEUE) received\n");
 468                 stop_exec_q = 0;
 469                 event_queue_manager(udev);
 470         }
 471
 472         if (udev_ctrl_get_reload_rules(ctrl_msg) > 0) {
 473                 info(udev, "udevd message (RELOAD_RULES) received\n");
 474                 reload_config = 1;
 475         }
 476
 477         str = udev_ctrl_get_set_env(ctrl_msg);
 478         if (str != NULL) {
 479                 char *key;
 480
 481                 key = strdup(str);
 482                 if (key != NULL) {
 483                         char *val;
 484
 485                         val = strchr(key, '=');
 486                         if (val != NULL) {
 487                                 val[0] = '\0';
 488                                 val = &val[1];
 489                                 if (val[0] == '\0') {
 490                                         info(udev, "udevd message (ENV) received, unset '%s'\n", key);
 491                                         udev_add_property(udev, key, NULL);
 492                                 } else {
 493                                         info(udev, "udevd message (ENV) received, set '%s=%s'\n", key, val);
 494                                         udev_add_property(udev, key, val);
 495                                 }
 496                         } else {
 497                                 err(udev, "wrong key format '%s'\n", key);
 498                         }
 499                         free(key);
 500                 }
 501         }
 502
 503         i = udev_ctrl_get_set_max_childs(ctrl_msg);
 504         if (i >= 0) {
 505                 info(udev, "udevd message (SET_MAX_CHILDS) received, max_childs=%i\n", i);
 506                 max_childs = i;
 507         }
 508
 509         settle_pid = udev_ctrl_get_settle(ctrl_msg);
 510         if (settle_pid > 0) {
 511                 info(udev, "udevd message (SETTLE) received\n");
 512         }
 513         udev_ctrl_msg_unref(ctrl_msg);
 514 }
 515
 516 /* read inotify messages */
 517 static int handle_inotify(struct udev *udev)
 518 {
 519         int nbytes, pos;
 520         char *buf;
 521         struct inotify_event *ev;
 522
 523         if ((ioctl(inotify_fd, FIONREAD, &nbytes) < 0) || (nbytes <= 0))
 524                 return 0;
 525
 526         buf = malloc(nbytes);
 527         if (buf == NULL) {
 528                 err(udev, "error getting buffer for inotify, disable watching\n");
 529                 close(inotify_fd);
 530                 inotify_fd = -1;
 531                 return 0;
 532         }
 533
 534         read(inotify_fd, buf, nbytes);
 535
 536         for (pos = 0; pos < nbytes; pos += sizeof(struct inotify_event) + ev->len) {
 537                 struct udev_device *dev;
 538
 539                 ev = (struct inotify_event *)(buf + pos);
 540                 if (ev->len) {
 541                         dbg(udev, "inotify event: %x for %s\n", ev->mask, ev->name);
 542                         reload_config = 1;
 543                         continue;
 544                 }
 545
 546                 dev = udev_watch_lookup(udev, ev->wd);
 547                 if (dev != NULL) {
 548                         dbg(udev, "inotify event: %x for %s\n", ev->mask, udev_device_get_devnode(dev));
 549                         if (ev->mask & IN_CLOSE_WRITE) {
 550                                 char filename[UTIL_PATH_SIZE];
 551                                 int fd;
 552
 553                                 info(udev, "device %s closed, synthesising 'change'\n", udev_device_get_devnode(dev));
 554                                 util_strlcpy(filename, udev_device_get_syspath(dev), sizeof(filename));
 555                                 util_strlcat(filename, "/uevent", sizeof(filename));
 556                                 fd = open(filename, O_WRONLY);
 557                                 if (fd < 0 || write(fd, "change", 6) < 0)
 558                                         info(udev, "error writing uevent: %m\n");
 559                                 close(fd);
 560                         }
 561                         if (ev->mask & IN_IGNORED)
 562                                 udev_watch_end(udev, dev);
 563
 564                         udev_device_unref(dev);
 565                 }
 566
 567         }
 568
 569         free (buf);
 570         return 0;
 571 }
 572
 573 static void sig_handler(int signum)
 574 {
 575         switch (signum) {
 576                 case SIGINT:
 577                 case SIGTERM:
 578                         udev_exit = 1;
 579                         break;
 580                 case SIGCHLD:
 581                         /* set flag, then write to pipe if needed */
 582                         sigchilds_waiting = 1;
 583                         break;
 584                 case SIGHUP:
 585                         reload_config = 1;
 586                         break;
 587         }
 588
 589         signal_received = 1;
 590 }
 591
 592 static void udev_done(int pid, int exitstatus)
 593 {
 594         struct udev_list_node *loop;
 595
 596         /* find event associated with pid and delete it */
 597         udev_list_node_foreach(loop, &event_list) {
 598                 struct udev_event *loop_event = node_to_event(loop);
 599
 600                 if (loop_event->pid == pid) {
 601                         info(loop_event->udev, "seq %llu cleanup, pid [%d], status %i, %ld seconds old\n",
 602                              udev_device_get_seqnum(loop_event->dev), loop_event->pid,
 603                              exitstatus, time(NULL) - loop_event->queue_time);
 604                         loop_event->exitstatus = exitstatus;
 605                         if (debug_trace)
 606                                 fprintf(stderr, "exit %s (%llu)\n",
 607                                        udev_device_get_syspath(loop_event->dev),
 608                                        udev_device_get_seqnum(loop_event->dev));
 609                         event_queue_delete(loop_event);
 610                         childs--;
 611
 612                         /* there may be dependent events waiting */
 613                         run_exec_q = 1;
 614                         return;
 615                 }
 616         }
 617 }
 618
 619 static void reap_sigchilds(void)
 620 {
 621         pid_t pid;
 622         int status;
 623
 624         while (1) {
 625                 pid = waitpid(-1, &status, WNOHANG);
 626                 if (pid <= 0)
 627                         break;
 628                 if (WIFEXITED(status))
 629                         status = WEXITSTATUS(status);
 630                 else if (WIFSIGNALED(status))
 631                         status = WTERMSIG(status) + 128;
 632                 else
 633                         status = 0;
 634                 udev_done(pid, status);
 635         }
 636 }
 637
 638 static void cleanup_queue_dir(struct udev *udev)
 639 {
 640         char dirname[UTIL_PATH_SIZE];
 641         char filename[UTIL_PATH_SIZE];
 642         DIR *dir;
 643
 644         util_strlcpy(filename, udev_get_dev_path(udev), sizeof(filename));
 645         util_strlcat(filename, "/.udev/uevent_seqnum", sizeof(filename));
 646         unlink(filename);
 647
 648         util_strlcpy(dirname, udev_get_dev_path(udev), sizeof(dirname));
 649         util_strlcat(dirname, "/.udev/queue", sizeof(dirname));
 650         dir = opendir(dirname);
 651         if (dir != NULL) {
 652                 while (1) {
 653                         struct dirent *dent;
 654
 655                         dent = readdir(dir);
 656                         if (dent == NULL || dent->d_name[0] == '\0')
 657                                 break;
 658                         if (dent->d_name[0] == '.')
 659                                 continue;
 660                         util_strlcpy(filename, dirname, sizeof(filename));
 661                         util_strlcat(filename, "/", sizeof(filename));
 662                         util_strlcat(filename, dent->d_name, sizeof(filename));
 663                         unlink(filename);
 664                 }
 665                 closedir(dir);
 666                 rmdir(dirname);
 667         }
 668 }
 669
 670 static void export_initial_seqnum(struct udev *udev)
 671 {
 672         char filename[UTIL_PATH_SIZE];
 673         int fd;
 674         char seqnum[32];
 675         ssize_t len = 0;
 676
 677         util_strlcpy(filename, udev_get_sys_path(udev), sizeof(filename));
 678         util_strlcat(filename, "/kernel/uevent_seqnum", sizeof(filename));
 679         fd = open(filename, O_RDONLY);
 680         if (fd >= 0) {
 681                 len = read(fd, seqnum, sizeof(seqnum)-1);
 682                 close(fd);
 683         }
 684         if (len <= 0) {
 685                 strcpy(seqnum, "0\n");
 686                 len = 3;
 687         }
 688         util_strlcpy(filename, udev_get_dev_path(udev), sizeof(filename));
 689         util_strlcat(filename, "/.udev/uevent_seqnum", sizeof(filename));
 690         util_create_path(udev, filename);
 691         fd = open(filename, O_WRONLY|O_TRUNC|O_CREAT, 0644);
 692         if (fd >= 0) {
 693                 write(fd, seqnum, len);
 694                 close(fd);
 695         }
 696 }
 697
 698 static void startup_log(struct udev *udev)
 699 {
 700         FILE *f;
 701         char path[UTIL_PATH_SIZE];
 702         struct stat statbuf;
 703
 704         f = fopen("/dev/kmsg", "w");
 705         if (f != NULL)
 706                 fprintf(f, "<6>udev: starting version " VERSION "\n");
 707
 708         util_strlcpy(path, udev_get_sys_path(udev), sizeof(path));
 709         util_strlcat(path, "/class/mem/null", sizeof(path));
 710         if (lstat(path, &statbuf) == 0 && S_ISDIR(statbuf.st_mode)) {
 711                 const char *depr_str =
 712                         "udev: missing sysfs features; please update the kernel "
 713                         "or disable the kernel's CONFIG_SYSFS_DEPRECATED option; "
 714                         "udev may fail to work correctly";
 715
 716                 if (f != NULL)
 717                         fprintf(f, "<3>%s\n", depr_str);
 718                 err(udev, "%s\n", depr_str);
 719                 sleep(3);
 720         }
 721
 722         if (f != NULL)
 723                 fclose(f);
 724 }
 725
 726 int main(int argc, char *argv[])
 727 {
 728         struct udev *udev;
 729         int fd;
 730         struct sigaction act;
 731         const char *value;
 732         int daemonize = 0;
 733         int resolve_names = 1;
 734         static const struct option options[] = {
 735                 { "daemon", no_argument, NULL, 'd' },
 736                 { "debug-trace", no_argument, NULL, 't' },
 737                 { "debug", no_argument, NULL, 'D' },
 738                 { "help", no_argument, NULL, 'h' },
 739                 { "version", no_argument, NULL, 'V' },
 740                 { "resolve-names", required_argument, NULL, 'N' },
 741                 {}
 742         };
 743         int rc = 1;
 744
 745         udev = udev_new();
 746         if (udev == NULL)
 747                 goto exit;
 748
 749         logging_init("udevd");
 750         udev_set_log_fn(udev, log_fn);
 751         info(udev, "version %s\n", VERSION);
 752         udev_selinux_init(udev);
 753
 754         while (1) {
 755                 int option;
 756
 757                 option = getopt_long(argc, argv, "dDthV", options, NULL);
 758                 if (option == -1)
 759                         break;
 760
 761                 switch (option) {
 762                 case 'd':
 763                         daemonize = 1;
 764                         break;
 765                 case 't':
 766                         debug_trace = 1;
 767                         break;
 768                 case 'D':
 769                         debug = 1;
 770                         if (udev_get_log_priority(udev) < LOG_INFO)
 771                                 udev_set_log_priority(udev, LOG_INFO);
 772                         break;
 773                 case 'N':
 774                         if (strcmp (optarg, "early") == 0) {
 775                                 resolve_names = 1;
 776                         } else if (strcmp (optarg, "late") == 0) {
 777                                 resolve_names = 0;
 778                         } else if (strcmp (optarg, "never") == 0) {
 779                                 resolve_names = -1;
 780                         } else {
 781                                 fprintf(stderr, "resolve-names must be early, late or never\n");
 782                                 err(udev, "resolve-names must be early, late or never\n");
 783                                 goto exit;
 784                         }
 785                         break;
 786                 case 'h':
 787                         printf("Usage: udevd [--help] [--daemon] [--debug-trace] [--debug] "
 788                                "[--resolve-names=early|late|never] [--version]\n");
 789                         goto exit;
 790                 case 'V':
 791                         printf("%s\n", VERSION);
 792                         goto exit;
 793                 default:
 794                         goto exit;
 795                 }
 796         }
 797
 798         if (getuid() != 0) {
 799                 fprintf(stderr, "root privileges required\n");
 800                 err(udev, "root privileges required\n");
 801                 goto exit;
 802         }
 803
 804         /* make sure std{in,out,err} fd's are in a sane state */
 805         fd = open("/dev/null", O_RDWR);
 806         if (fd < 0) {
 807                 fprintf(stderr, "cannot open /dev/null\n");
 808                 err(udev, "cannot open /dev/null\n");
 809         }
 810         if (write(STDOUT_FILENO, 0, 0) < 0)
 811                 dup2(fd, STDOUT_FILENO);
 812         if (write(STDERR_FILENO, 0, 0) < 0)
 813                 dup2(fd, STDERR_FILENO);
 814
 815         /* init control socket, bind() ensures, that only one udevd instance is running */
 816         udev_ctrl = udev_ctrl_new_from_socket(udev, UDEV_CTRL_SOCK_PATH);
 817         if (udev_ctrl == NULL) {
 818                 fprintf(stderr, "error initializing control socket");
 819                 err(udev, "error initializing udevd socket");
 820                 rc = 1;
 821                 goto exit;
 822         }
 823
 824         if (udev_ctrl_enable_receiving(udev_ctrl) < 0) {
 825                 fprintf(stderr, "error binding control socket, seems udevd is already running\n");
 826                 err(udev, "error binding control socket, seems udevd is already running\n");
 827                 rc = 1;
 828                 goto exit;
 829         }
 830
 831         kernel_monitor = udev_monitor_new_from_netlink(udev, "kernel");
 832         if (kernel_monitor == NULL || udev_monitor_enable_receiving(kernel_monitor) < 0) {
 833                 fprintf(stderr, "error initializing netlink socket\n");
 834                 err(udev, "error initializing netlink socket\n");
 835                 rc = 3;
 836                 goto exit;
 837         }
 838         udev_monitor_set_receive_buffer_size(kernel_monitor, 128*1024*1024);
 839
 840         rules = udev_rules_new(udev, resolve_names);
 841         if (rules == NULL) {
 842                 err(udev, "error reading rules\n");
 843                 goto exit;
 844         }
 845         udev_list_init(&event_list);
 846         cleanup_queue_dir(udev);
 847         export_initial_seqnum(udev);
 848
 849         if (daemonize) {
 850                 pid_t pid;
 851
 852                 pid = fork();
 853                 switch (pid) {
 854                 case 0:
 855                         dbg(udev, "daemonized fork running\n");
 856                         break;
 857                 case -1:
 858                         err(udev, "fork of daemon failed: %m\n");
 859                         rc = 4;
 860                         goto exit;
 861                 default:
 862                         dbg(udev, "child [%u] running, parent exits\n", pid);
 863                         rc = 0;
 864                         goto exit;
 865                 }
 866         }
 867
 868         /* redirect std{out,err} */
 869         if (!debug && !debug_trace) {
 870                 dup2(fd, STDIN_FILENO);
 871                 dup2(fd, STDOUT_FILENO);
 872                 dup2(fd, STDERR_FILENO);
 873         }
 874         if (fd > STDERR_FILENO)
 875                 close(fd);
 876
 877         /* set scheduling priority for the daemon */
 878         setpriority(PRIO_PROCESS, 0, UDEVD_PRIORITY);
 879
 880         chdir("/");
 881         umask(022);
 882         setsid();
 883
 884         /* OOM_DISABLE == -17 */
 885         fd = open("/proc/self/oom_adj", O_RDWR);
 886         if (fd < 0)
 887                 err(udev, "error disabling OOM: %m\n");
 888         else {
 889                 write(fd, "-17", 3);
 890                 close(fd);
 891         }
 892
 893         startup_log(udev);
 894
 895         /* set signal handlers */
 896         memset(&act, 0x00, sizeof(struct sigaction));
 897         act.sa_handler = sig_handler;
 898         sigemptyset(&act.sa_mask);
 899         act.sa_flags = SA_RESTART;
 900         sigaction(SIGINT, &act, NULL);
 901         sigaction(SIGTERM, &act, NULL);
 902         sigaction(SIGCHLD, &act, NULL);
 903         sigaction(SIGHUP, &act, NULL);
 904
 905         /* watch rules directory */
 906         udev_watch_init(udev);
 907         if (inotify_fd >= 0) {
 908                 if (udev_get_rules_path(udev) != NULL) {
 909                         inotify_add_watch(inotify_fd, udev_get_rules_path(udev),
 910                                           IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
 911                 } else {
 912                         char filename[UTIL_PATH_SIZE];
 913
 914                         inotify_add_watch(inotify_fd, UDEV_PREFIX "/lib/udev/rules.d",
 915                                           IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
 916                         inotify_add_watch(inotify_fd, SYSCONFDIR "/udev/rules.d",
 917                                           IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
 918
 919                         /* watch dynamic rules directory */
 920                         util_strlcpy(filename, udev_get_dev_path(udev), sizeof(filename));
 921                         util_strlcat(filename, "/.udev/rules.d", sizeof(filename));
 922                         inotify_add_watch(inotify_fd, filename,
 923                                           IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
 924                 }
 925
 926                 udev_watch_restore(udev);
 927         }
 928
 929         /* in trace mode run one event after the other */
 930         if (debug_trace) {
 931                 max_childs = 1;
 932         } else {
 933                 int memsize = mem_size_mb();
 934                 if (memsize > 0)
 935                         max_childs = 128 + (memsize / 4);
 936                 else
 937                         max_childs = UDEVD_MAX_CHILDS;
 938         }
 939         /* possibly overwrite maximum limit of executed events */
 940         value = getenv("UDEVD_MAX_CHILDS");
 941         if (value)
 942                 max_childs = strtoul(value, NULL, 10);
 943         info(udev, "initialize max_childs to %u\n", max_childs);
 944
 945         while (!udev_exit) {
 946                 sigset_t blocked_mask, orig_mask;
 947                 struct pollfd pfd[4];
 948                 struct pollfd *ctrl_poll, *monitor_poll, *inotify_poll = NULL;
 949                 int nfds = 0;
 950                 int fdcount;
 951
 952                 sigfillset(&blocked_mask);
 953                 sigprocmask(SIG_SETMASK, &blocked_mask, &orig_mask);
 954                 if (signal_received) {
 955                         sigprocmask(SIG_SETMASK, &orig_mask, NULL);
 956                         goto handle_signals;
 957                 }
 958
 959                 ctrl_poll = &pfd[nfds++];
 960                 ctrl_poll->fd = udev_ctrl_get_fd(udev_ctrl);
 961                 ctrl_poll->events = POLLIN;
 962
 963                 monitor_poll = &pfd[nfds++];
 964                 monitor_poll->fd = udev_monitor_get_fd(kernel_monitor);
 965                 monitor_poll->events = POLLIN;
 966
 967                 if (inotify_fd >= 0) {
 968                         inotify_poll = &pfd[nfds++];
 969                         inotify_poll->fd = inotify_fd;
 970                         inotify_poll->events = POLLIN;
 971                 }
 972
 973                 fdcount = ppoll(pfd, nfds, NULL, &orig_mask);
 974                 sigprocmask(SIG_SETMASK, &orig_mask, NULL);
 975                 if (fdcount < 0) {
 976                         if (errno == EINTR)
 977                                 goto handle_signals;
 978                         err(udev, "error in select: %m\n");
 979                         continue;
 980                 }
 981
 982                 /* get control message */
 983                 if (ctrl_poll->revents & POLLIN)
 984                         handle_ctrl_msg(udev_ctrl);
 985
 986                 /* get kernel uevent */
 987                 if (monitor_poll->revents & POLLIN) {
 988                         struct udev_device *dev;
 989
 990                         dev = udev_monitor_receive_device(kernel_monitor);
 991                         if (dev != NULL) {
 992                                 struct udev_event *event;
 993
 994                                 event = udev_event_new(dev);
 995                                 if (event != NULL)
 996                                         event_queue_insert(event);
 997                                 else
 998                                         udev_device_unref(dev);
 999                         }
1000                 }
1001
1002                 /* rules directory inotify watch */
1003                 if (inotify_poll && (inotify_poll->revents & POLLIN))
1004                         handle_inotify(udev);
1005
1006 handle_signals:
1007                 signal_received = 0;
1008
1009                 /* rules changed, set by inotify or a HUP signal */
1010                 if (reload_config) {
1011                         struct udev_rules *rules_new;
1012
1013                         reload_config = 0;
1014                         rules_new = udev_rules_new(udev, resolve_names);
1015                         if (rules_new != NULL) {
1016                                 udev_rules_unref(rules);
1017                                 rules = rules_new;
1018                         }
1019                 }
1020
1021                 if (sigchilds_waiting) {
1022                         sigchilds_waiting = 0;
1023                         reap_sigchilds();
1024                 }
1025
1026                 if (run_exec_q) {
1027                         run_exec_q = 0;
1028                         if (!stop_exec_q)
1029                                 event_queue_manager(udev);
1030                 }
1031
1032                 if (settle_pid > 0) {
1033                         kill(settle_pid, SIGUSR1);
1034                         settle_pid = 0;
1035                 }
1036         }
1037         cleanup_queue_dir(udev);
1038         rc = 0;
1039 exit:
1040         udev_rules_unref(rules);
1041         udev_ctrl_unref(udev_ctrl);
1042         if (inotify_fd >= 0)
1043                 close(inotify_fd);
1044         udev_monitor_unref(kernel_monitor);
1045         udev_selinux_exit(udev);
1046         udev_unref(udev);
1047         logging_close();
1048         return rc;
1049 }