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