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