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                 /* clear any existing udev watch on the node */
 219                 udev_watch_clear(event->udev, event->dev);
 220
 221                 /* apply rules, create node, symlinks */
 222                 err = udev_event_execute_rules(event, rules);
 223
 224                 /* rules may change/disable the timeout */
 225                 if (udev_device_get_event_timeout(event->dev) >= 0)
 226                         alarm(udev_device_get_event_timeout(event->dev));
 227
 228                 /* execute RUN= */
 229                 if (err == 0 && !event->ignore_device && udev_get_run(event->udev))
 230                         udev_event_execute_run(event);
 231
 232                 /* apply/restore inotify watch */
 233                 if (err == 0 && event->inotify_watch &&
 234                     strcmp(udev_device_get_action(event->dev), "remove") != 0)
 235                         info(event->udev, "device will be watched for changes\n");
 236                         udev_watch_begin(event->udev, event->dev);
 237
 238                 info(event->udev, "seq %llu exit with %i\n", udev_device_get_seqnum(event->dev), err);
 239                 logging_close();
 240                 if (err != 0)
 241                         exit(1);
 242                 exit(0);
 243         case -1:
 244                 err(event->udev, "fork of child failed: %m\n");
 245                 event_queue_delete(event);
 246                 break;
 247         default:
 248                 /* get SIGCHLD in main loop */
 249                 info(event->udev, "seq %llu forked, pid [%d], '%s' '%s', %ld seconds old\n",
 250                      udev_device_get_seqnum(event->dev),
 251                      pid,
 252                      udev_device_get_action(event->dev),
 253                      udev_device_get_subsystem(event->dev),
 254                      time(NULL) - event->queue_time);
 255                 event->pid = pid;
 256                 childs++;
 257         }
 258 }
 259
 260 static void event_queue_insert(struct udev_event *event)
 261 {
 262         char filename[UTIL_PATH_SIZE];
 263         int fd;
 264
 265         event->queue_time = time(NULL);
 266
 267         export_event_state(event, EVENT_QUEUED);
 268         info(event->udev, "seq %llu queued, '%s' '%s'\n", udev_device_get_seqnum(event->dev),
 269              udev_device_get_action(event->dev), udev_device_get_subsystem(event->dev));
 270
 271         util_strlcpy(filename, udev_get_dev_path(event->udev), sizeof(filename));
 272         util_strlcat(filename, "/.udev/uevent_seqnum", sizeof(filename));
 273         fd = open(filename, O_WRONLY|O_TRUNC|O_CREAT, 0644);
 274         if (fd >= 0) {
 275                 char str[32];
 276                 int len;
 277
 278                 len = sprintf(str, "%llu\n", udev_device_get_seqnum(event->dev));
 279                 write(fd, str, len);
 280                 close(fd);
 281         }
 282
 283
 284         udev_list_node_append(&event->node, &event_list);
 285         run_exec_q = 1;
 286
 287         /* run all events with a timeout set immediately */
 288         if (udev_device_get_timeout(event->dev) > 0) {
 289                 event_fork(event);
 290                 return;
 291         }
 292 }
 293
 294 static int mem_size_mb(void)
 295 {
 296         FILE* f;
 297         char buf[4096];
 298         long int memsize = -1;
 299
 300         f = fopen("/proc/meminfo", "r");
 301         if (f == NULL)
 302                 return -1;
 303
 304         while (fgets(buf, sizeof(buf), f) != NULL) {
 305                 long int value;
 306
 307                 if (sscanf(buf, "MemTotal: %ld kB", &value) == 1) {
 308                         memsize = value / 1024;
 309                         break;
 310                 }
 311         }
 312
 313         fclose(f);
 314         return memsize;
 315 }
 316
 317 static int compare_devpath(const char *running, const char *waiting)
 318 {
 319         int i = 0;
 320
 321         while (running[i] != '\0' && running[i] == waiting[i])
 322                 i++;
 323
 324         /* identical device event found */
 325         if (running[i] == '\0' && waiting[i] == '\0')
 326                 return 1;
 327
 328         /* parent device event found */
 329         if (running[i] == '\0' && waiting[i] == '/')
 330                 return 2;
 331
 332         /* child device event found */
 333         if (running[i] == '/' && waiting[i] == '\0')
 334                 return 3;
 335
 336         /* no matching event */
 337         return 0;
 338 }
 339
 340 /* lookup event for identical, parent, child, or physical device */
 341 static int devpath_busy(struct udev_event *event)
 342 {
 343         struct udev_list_node *loop;
 344
 345         if (event->delaying_seqnum > 0) {
 346         }
 347         /* check if queue contains events we depend on */
 348         udev_list_node_foreach(loop, &event_list) {
 349                 struct udev_event *loop_event = node_to_event(loop);
 350
 351                 /* we already found a later event, earlier can not block us, no need to check again */
 352                 if (udev_device_get_seqnum(loop_event->dev) < event->delaying_seqnum)
 353                         continue;
 354
 355                 /* event we checked earlier still exists, no need to check again */
 356                 if (udev_device_get_seqnum(loop_event->dev) == event->delaying_seqnum)
 357                         return 2;
 358
 359                 /* found ourself, no later event can block us */
 360                 if (udev_device_get_seqnum(loop_event->dev) >= udev_device_get_seqnum(event->dev))
 361                         break;
 362
 363                 /* check our old name */
 364                 if (udev_device_get_devpath_old(event->dev) != NULL)
 365                         if (strcmp(udev_device_get_devpath(loop_event->dev), udev_device_get_devpath_old(event->dev)) == 0) {
 366                                 event->delaying_seqnum = udev_device_get_seqnum(loop_event->dev);
 367                                 return 3;
 368                         }
 369
 370                 /* check identical, parent, or child device event */
 371                 if (compare_devpath(udev_device_get_devpath(loop_event->dev), udev_device_get_devpath(event->dev)) != 0) {
 372                         dbg(event->udev, "%llu, device event still pending %llu (%s)\n",
 373                             udev_device_get_seqnum(event->dev),
 374                             udev_device_get_seqnum(loop_event->dev),
 375                             udev_device_get_devpath(loop_event->dev));
 376                         event->delaying_seqnum = udev_device_get_seqnum(loop_event->dev);
 377                         return 4;
 378                 }
 379
 380                 /* check for our major:minor number */
 381                 if (major(udev_device_get_devnum(event->dev)) > 0 &&
 382                     udev_device_get_devnum(loop_event->dev) == udev_device_get_devnum(event->dev) &&
 383                     strcmp(udev_device_get_subsystem(event->dev), udev_device_get_subsystem(loop_event->dev)) == 0) {
 384                         dbg(event->udev, "%llu, device event still pending %llu (%d:%d)\n",
 385                             udev_device_get_seqnum(event->dev),
 386                             udev_device_get_seqnum(loop_event->dev),
 387                             major(udev_device_get_devnum(loop_event->dev)), minor(udev_device_get_devnum(loop_event->dev)));
 388                         event->delaying_seqnum = udev_device_get_seqnum(loop_event->dev);
 389                         return 5;
 390                 }
 391
 392                 /* check physical device event (special case of parent) */
 393                 if (udev_device_get_physdevpath(event->dev) != NULL &&
 394                     strcmp(udev_device_get_action(event->dev), "add") == 0)
 395                         if (compare_devpath(udev_device_get_devpath(loop_event->dev),
 396                                             udev_device_get_physdevpath(event->dev)) != 0) {
 397                                 dbg(event->udev, "%llu, physical device event still pending %llu (%s)\n",
 398                                     udev_device_get_seqnum(event->dev),
 399                                     udev_device_get_seqnum(loop_event->dev),
 400                                     udev_device_get_devpath(loop_event->dev));
 401                                 event->delaying_seqnum = udev_device_get_seqnum(loop_event->dev);
 402                                 return 6;
 403                         }
 404         }
 405         return 0;
 406 }
 407
 408 /* serializes events for the identical and parent and child devices */
 409 static void event_queue_manager(struct udev *udev)
 410 {
 411         struct udev_list_node *loop;
 412         struct udev_list_node *tmp;
 413
 414 start_over:
 415         if (udev_list_is_empty(&event_list)) {
 416                 if (childs > 0) {
 417                         err(udev, "event list empty, but childs count is %i", childs);
 418                         childs = 0;
 419                 }
 420                 return;
 421         }
 422
 423         udev_list_node_foreach_safe(loop, tmp, &event_list) {
 424                 struct udev_event *loop_event = node_to_event(loop);
 425
 426                 if (childs >= max_childs) {
 427                         info(udev, "maximum number (%i) of childs reached\n", childs);
 428                         break;
 429                 }
 430
 431                 if (loop_event->pid != 0)
 432                         continue;
 433
 434                 /* do not start event if parent or child event is still running */
 435                 if (devpath_busy(loop_event) != 0) {
 436                         dbg(udev, "delay seq %llu (%s)\n",
 437                             udev_device_get_seqnum(loop_event->dev),
 438                             udev_device_get_devpath(loop_event->dev));
 439                         continue;
 440                 }
 441
 442                 event_fork(loop_event);
 443                 dbg(udev, "moved seq %llu to running list\n", udev_device_get_seqnum(loop_event->dev));
 444
 445                 /* retry if events finished in the meantime */
 446                 if (sigchilds_waiting) {
 447                         sigchilds_waiting = 0;
 448                         reap_sigchilds();
 449                         goto start_over;
 450                 }
 451         }
 452 }
 453
 454 /* receive the udevd message from userspace */
 455 static void handle_ctrl_msg(struct udev_ctrl *uctrl)
 456 {
 457         struct udev *udev = udev_ctrl_get_udev(uctrl);
 458         struct udev_ctrl_msg *ctrl_msg;
 459         const char *str;
 460         int i;
 461
 462         ctrl_msg = udev_ctrl_receive_msg(uctrl);
 463         if (ctrl_msg == NULL)
 464                 return;
 465
 466         i = udev_ctrl_get_set_log_level(ctrl_msg);
 467         if (i >= 0) {
 468                 info(udev, "udevd message (SET_LOG_PRIORITY) received, log_priority=%i\n", i);
 469                 udev_set_log_priority(udev, i);
 470         }
 471
 472         if (udev_ctrl_get_stop_exec_queue(ctrl_msg) > 0) {
 473                 info(udev, "udevd message (STOP_EXEC_QUEUE) received\n");
 474                 stop_exec_q = 1;
 475         }
 476
 477         if (udev_ctrl_get_start_exec_queue(ctrl_msg) > 0) {
 478                 info(udev, "udevd message (START_EXEC_QUEUE) received\n");
 479                 stop_exec_q = 0;
 480                 event_queue_manager(udev);
 481         }
 482
 483         if (udev_ctrl_get_reload_rules(ctrl_msg) > 0) {
 484                 info(udev, "udevd message (RELOAD_RULES) received\n");
 485                 reload_config = 1;
 486         }
 487
 488         str = udev_ctrl_get_set_env(ctrl_msg);
 489         if (str != NULL) {
 490                 char *key;
 491
 492                 key = strdup(str);
 493                 if (key != NULL) {
 494                         char *val;
 495
 496                         val = strchr(key, '=');
 497                         if (val != NULL) {
 498                                 val[0] = '\0';
 499                                 val = &val[1];
 500                                 if (val[0] == '\0') {
 501                                         info(udev, "udevd message (ENV) received, unset '%s'\n", key);
 502                                         udev_add_property(udev, key, NULL);
 503                                 } else {
 504                                         info(udev, "udevd message (ENV) received, set '%s=%s'\n", key, val);
 505                                         udev_add_property(udev, key, val);
 506                                 }
 507                         } else {
 508                                 err(udev, "wrong key format '%s'\n", key);
 509                         }
 510                         free(key);
 511                 }
 512         }
 513
 514         i = udev_ctrl_get_set_max_childs(ctrl_msg);
 515         if (i >= 0) {
 516                 info(udev, "udevd message (SET_MAX_CHILDS) received, max_childs=%i\n", i);
 517                 max_childs = i;
 518         }
 519         udev_ctrl_msg_unref(ctrl_msg);
 520 }
 521
 522 /* read inotify messages */
 523 static int handle_inotify(struct udev *udev)
 524 {
 525         int nbytes, pos;
 526         char *buf;
 527         struct inotify_event *ev;
 528
 529         if ((ioctl(inotify_fd, FIONREAD, &nbytes) < 0) || (nbytes <= 0))
 530                 return 0;
 531
 532         buf = malloc(nbytes);
 533         if (buf == NULL) {
 534                 err(udev, "error getting buffer for inotify, disable watching\n");
 535                 close(inotify_fd);
 536                 inotify_fd = -1;
 537                 return 0;
 538         }
 539
 540         read(inotify_fd, buf, nbytes);
 541
 542         for (pos = 0, ev = (struct inotify_event *)(buf + pos); pos < nbytes; pos += sizeof(struct inotify_event) + ev->len) {
 543                 const char *syspath;
 544
 545                 dbg(udev, "inotify event: %x for %d (%s)\n", ev->mask, ev->wd, ev->len ? ev->name : "*");
 546
 547                 syspath = udev_watch_lookup(udev, ev->wd);
 548                 if (syspath != NULL) {
 549                         dbg(udev, "inotify event: %x for %s\n", ev->mask, syspath);
 550                         if (ev->mask & IN_CLOSE_WRITE) {
 551                                 char filename[UTIL_PATH_SIZE];
 552                                 int fd;
 553
 554                                 info(udev, "device %s closed, synthesising 'change'\n", syspath);
 555                                 util_strlcpy(filename, syspath, sizeof(filename));
 556                                 util_strlcat(filename, "/uevent", sizeof(filename));
 557                                 fd = open(filename, O_WRONLY);
 558                                 if (fd < 0 || write(fd, "change", 6) < 0)
 559                                         info(udev, "error writing uevent: %m\n");
 560                                 close(fd);
 561                         }
 562                         if (ev->mask & IN_IGNORED)
 563                                 udev_watch_end(udev, ev->wd);
 564                 } else {
 565                         reload_config = 1;
 566                 }
 567         }
 568
 569         free (buf);
 570         return 0;
 571 }
 572
 573 static void asmlinkage 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 int main(int argc, char *argv[])
 699 {
 700         struct udev *udev;
 701         int fd;
 702         struct sigaction act;
 703         const char *value;
 704         int daemonize = 0;
 705         int resolve_names = 1;
 706         static const struct option options[] = {
 707                 { "daemon", no_argument, NULL, 'd' },
 708                 { "debug-trace", no_argument, NULL, 't' },
 709                 { "debug", no_argument, NULL, 'D' },
 710                 { "help", no_argument, NULL, 'h' },
 711                 { "version", no_argument, NULL, 'V' },
 712                 { "resolve-names", required_argument, NULL, 'N' },
 713                 {}
 714         };
 715         int rc = 1;
 716
 717         udev = udev_new();
 718         if (udev == NULL)
 719                 goto exit;
 720
 721         logging_init("udevd");
 722         udev_set_log_fn(udev, log_fn);
 723         info(udev, "version %s\n", VERSION);
 724         udev_selinux_init(udev);
 725
 726         while (1) {
 727                 int option;
 728
 729                 option = getopt_long(argc, argv, "dDthV", options, NULL);
 730                 if (option == -1)
 731                         break;
 732
 733                 switch (option) {
 734                 case 'd':
 735                         daemonize = 1;
 736                         break;
 737                 case 't':
 738                         debug_trace = 1;
 739                         break;
 740                 case 'D':
 741                         debug = 1;
 742                         if (udev_get_log_priority(udev) < LOG_INFO)
 743                                 udev_set_log_priority(udev, LOG_INFO);
 744                         break;
 745                 case 'N':
 746                         if (strcmp (optarg, "early") == 0) {
 747                                 resolve_names = 1;
 748                         } else if (strcmp (optarg, "late") == 0) {
 749                                 resolve_names = 0;
 750                         } else if (strcmp (optarg, "never") == 0) {
 751                                 resolve_names = -1;
 752                         } else {
 753                                 fprintf(stderr, "resolve-names must be early, late or never\n");
 754                                 err(udev, "resolve-names must be early, late or never\n");
 755                                 goto exit;
 756                         }
 757                         break;
 758                 case 'h':
 759                         printf("Usage: udevd [--help] [--daemon] [--debug-trace] [--debug] "
 760                                "[--resolve-names=early|late|never] [--version]\n");
 761                         goto exit;
 762                 case 'V':
 763                         printf("%s\n", VERSION);
 764                         goto exit;
 765                 default:
 766                         goto exit;
 767                 }
 768         }
 769
 770         if (getuid() != 0) {
 771                 fprintf(stderr, "root privileges required\n");
 772                 err(udev, "root privileges required\n");
 773                 goto exit;
 774         }
 775
 776         /* make sure std{in,out,err} fd's are in a sane state */
 777         fd = open("/dev/null", O_RDWR);
 778         if (fd < 0) {
 779                 fprintf(stderr, "cannot open /dev/null\n");
 780                 err(udev, "cannot open /dev/null\n");
 781         }
 782         if (write(STDOUT_FILENO, 0, 0) < 0)
 783                 dup2(fd, STDOUT_FILENO);
 784         if (write(STDERR_FILENO, 0, 0) < 0)
 785                 dup2(fd, STDERR_FILENO);
 786
 787         /* init control socket, bind() ensures, that only one udevd instance is running */
 788         udev_ctrl = udev_ctrl_new_from_socket(udev, UDEV_CTRL_SOCK_PATH);
 789         if (udev_ctrl == NULL) {
 790                 fprintf(stderr, "error initializing control socket");
 791                 err(udev, "error initializing udevd socket");
 792                 rc = 1;
 793                 goto exit;
 794         }
 795
 796         if (udev_ctrl_enable_receiving(udev_ctrl) < 0) {
 797                 fprintf(stderr, "error binding control socket, seems udevd is already running\n");
 798                 err(udev, "error binding control socket, seems udevd is already running\n");
 799                 rc = 1;
 800                 goto exit;
 801         }
 802
 803         kernel_monitor = udev_monitor_new_from_netlink(udev);
 804         if (kernel_monitor == NULL || udev_monitor_enable_receiving(kernel_monitor) < 0) {
 805                 fprintf(stderr, "error initializing netlink socket\n");
 806                 err(udev, "error initializing netlink socket\n");
 807                 rc = 3;
 808                 goto exit;
 809         }
 810         udev_monitor_set_receive_buffer_size(kernel_monitor, 128*1024*1024);
 811
 812         rules = udev_rules_new(udev, resolve_names);
 813         if (rules == NULL) {
 814                 err(udev, "error reading rules\n");
 815                 goto exit;
 816         }
 817         udev_list_init(&event_list);
 818         cleanup_queue_dir(udev);
 819         export_initial_seqnum(udev);
 820
 821         if (daemonize) {
 822                 pid_t pid;
 823
 824                 pid = fork();
 825                 switch (pid) {
 826                 case 0:
 827                         dbg(udev, "daemonized fork running\n");
 828                         break;
 829                 case -1:
 830                         err(udev, "fork of daemon failed: %m\n");
 831                         rc = 4;
 832                         goto exit;
 833                 default:
 834                         dbg(udev, "child [%u] running, parent exits\n", pid);
 835                         rc = 0;
 836                         goto exit;
 837                 }
 838         }
 839
 840         /* redirect std{out,err} */
 841         if (!debug && !debug_trace) {
 842                 dup2(fd, STDIN_FILENO);
 843                 dup2(fd, STDOUT_FILENO);
 844                 dup2(fd, STDERR_FILENO);
 845         }
 846         if (fd > STDERR_FILENO)
 847                 close(fd);
 848
 849         /* set scheduling priority for the daemon */
 850         setpriority(PRIO_PROCESS, 0, UDEVD_PRIORITY);
 851
 852         chdir("/");
 853         umask(022);
 854         setsid();
 855
 856         /* OOM_DISABLE == -17 */
 857         fd = open("/proc/self/oom_adj", O_RDWR);
 858         if (fd < 0)
 859                 err(udev, "error disabling OOM: %m\n");
 860         else {
 861                 write(fd, "-17", 3);
 862                 close(fd);
 863         }
 864
 865         fd = open("/dev/kmsg", O_WRONLY);
 866         if (fd > 0) {
 867                 const char *ver_str = "<6>udev: starting version " VERSION "\n";
 868                 char path[UTIL_PATH_SIZE];
 869                 struct stat statbuf;
 870
 871                 write(fd, ver_str, strlen(ver_str));
 872                 util_strlcpy(path, udev_get_sys_path(udev), sizeof(path));
 873                 util_strlcat(path, "/class/mem/null", sizeof(path));
 874                 if (lstat(path, &statbuf) == 0) {
 875                         if (S_ISDIR(statbuf.st_mode)) {
 876                                 const char *depr_str =
 877                                         "<6>udev: deprecated sysfs layout; update the kernel or "
 878                                         "disable CONFIG_SYSFS_DEPRECATED; some udev features will "
 879                                         "not work correctly\n";
 880
 881                                 write(fd, depr_str, strlen(depr_str));
 882                         }
 883                 }
 884                 close(fd);
 885         }
 886
 887         /* set signal handlers */
 888         memset(&act, 0x00, sizeof(struct sigaction));
 889         act.sa_handler = (void (*)(int)) sig_handler;
 890         sigemptyset(&act.sa_mask);
 891         act.sa_flags = SA_RESTART;
 892         sigaction(SIGINT, &act, NULL);
 893         sigaction(SIGTERM, &act, NULL);
 894         sigaction(SIGCHLD, &act, NULL);
 895         sigaction(SIGHUP, &act, NULL);
 896
 897         /* watch rules directory */
 898         udev_watch_init(udev);
 899         if (inotify_fd >= 0) {
 900                 if (udev_get_rules_path(udev) != NULL) {
 901                         inotify_add_watch(inotify_fd, udev_get_rules_path(udev),
 902                                           IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
 903                 } else {
 904                         char filename[UTIL_PATH_SIZE];
 905
 906                         inotify_add_watch(inotify_fd, UDEV_PREFIX "/lib/udev/rules.d",
 907                                           IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
 908                         inotify_add_watch(inotify_fd, SYSCONFDIR "/udev/rules.d",
 909                                           IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
 910
 911                         /* watch dynamic rules directory */
 912                         util_strlcpy(filename, udev_get_dev_path(udev), sizeof(filename));
 913                         util_strlcat(filename, "/.udev/rules.d", sizeof(filename));
 914                         inotify_add_watch(inotify_fd, filename,
 915                                           IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
 916                 }
 917
 918                 udev_watch_restore(udev);
 919         }
 920
 921         /* in trace mode run one event after the other */
 922         if (debug_trace) {
 923                 max_childs = 1;
 924         } else {
 925                 int memsize = mem_size_mb();
 926                 if (memsize > 0)
 927                         max_childs = 128 + (memsize / 4);
 928                 else
 929                         max_childs = UDEVD_MAX_CHILDS;
 930         }
 931         /* possibly overwrite maximum limit of executed events */
 932         value = getenv("UDEVD_MAX_CHILDS");
 933         if (value)
 934                 max_childs = strtoul(value, NULL, 10);
 935         info(udev, "initialize max_childs to %u\n", max_childs);
 936
 937         while (!udev_exit) {
 938                 sigset_t blocked_mask, orig_mask;
 939                 struct pollfd pfd[4];
 940                 struct pollfd *ctrl_poll, *monitor_poll, *inotify_poll = NULL;
 941                 int nfds = 0;
 942                 int fdcount;
 943
 944                 sigfillset(&blocked_mask);
 945                 sigprocmask(SIG_SETMASK, &blocked_mask, &orig_mask);
 946                 if (signal_received) {
 947                         sigprocmask(SIG_SETMASK, &orig_mask, NULL);
 948                         goto handle_signals;
 949                 }
 950
 951                 ctrl_poll = &pfd[nfds++];
 952                 ctrl_poll->fd = udev_ctrl_get_fd(udev_ctrl);
 953                 ctrl_poll->events = POLLIN;
 954
 955                 monitor_poll = &pfd[nfds++];
 956                 monitor_poll->fd = udev_monitor_get_fd(kernel_monitor);
 957                 monitor_poll->events = POLLIN;
 958
 959                 if (inotify_fd >= 0) {
 960                         inotify_poll = &pfd[nfds++];
 961                         inotify_poll->fd = inotify_fd;
 962                         inotify_poll->events = POLLIN;
 963                 }
 964
 965                 fdcount = ppoll(pfd, nfds, NULL, &orig_mask);
 966                 sigprocmask(SIG_SETMASK, &orig_mask, NULL);
 967                 if (fdcount < 0) {
 968                         if (errno == EINTR)
 969                                 goto handle_signals;
 970                         err(udev, "error in select: %m\n");
 971                         continue;
 972                 }
 973
 974                 /* get control message */
 975                 if (ctrl_poll->revents & POLLIN)
 976                         handle_ctrl_msg(udev_ctrl);
 977
 978                 /* get kernel uevent */
 979                 if (monitor_poll->revents & POLLIN) {
 980                         struct udev_device *dev;
 981
 982                         dev = udev_monitor_receive_device(kernel_monitor);
 983                         if (dev != NULL) {
 984                                 struct udev_event *event;
 985
 986                                 event = udev_event_new(dev);
 987                                 if (event != NULL)
 988                                         event_queue_insert(event);
 989                                 else
 990                                         udev_device_unref(dev);
 991                         }
 992                 }
 993
 994                 /* rules directory inotify watch */
 995                 if (inotify_poll && (inotify_poll->revents & POLLIN))
 996                         handle_inotify(udev);
 997
 998 handle_signals:
 999                 signal_received = 0;
1000
1001                 /* rules changed, set by inotify or a HUP signal */
1002                 if (reload_config) {
1003                         struct udev_rules *rules_new;
1004
1005                         reload_config = 0;
1006                         rules_new = udev_rules_new(udev, resolve_names);
1007                         if (rules_new != NULL) {
1008                                 udev_rules_unref(rules);
1009                                 rules = rules_new;
1010                         }
1011                 }
1012
1013                 if (sigchilds_waiting) {
1014                         sigchilds_waiting = 0;
1015                         reap_sigchilds();
1016                 }
1017
1018                 if (run_exec_q) {
1019                         run_exec_q = 0;
1020                         if (!stop_exec_q)
1021                                 event_queue_manager(udev);
1022                 }
1023         }
1024         cleanup_queue_dir(udev);
1025         rc = 0;
1026 exit:
1027         udev_rules_unref(rules);
1028         udev_ctrl_unref(udev_ctrl);
1029         if (inotify_fd >= 0)
1030                 close(inotify_fd);
1031         udev_monitor_unref(kernel_monitor);
1032         udev_selinux_exit(udev);
1033         udev_unref(udev);
1034         logging_close();
1035         return rc;
1036 }