udev/udevd.c

   1 /*
   2  * Copyright (C) 2004-2008 Kay Sievers <kay.sievers@vrfy.org>
   3  * Copyright (C) 2004 Chris Friesen <chris_friesen@sympatico.ca>
   4  * Copyright (C) 2009 Canonical Ltd.
   5  * Copyright (C) 2009 Scott James Remnant <scott@netsplit.com>
   6  *
   7  * This program is free software: you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation, either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21 #include <stddef.h>
  22 #include <signal.h>
  23 #include <unistd.h>
  24 #include <errno.h>
  25 #include <stdio.h>
  26 #include <stdlib.h>
  27 #include <string.h>
  28 #include <ctype.h>
  29 #include <fcntl.h>
  30 #include <time.h>
  31 #include <getopt.h>
  32 #include <dirent.h>
  33 #include <sys/select.h>
  34 #include <sys/poll.h>
  35 #include <sys/wait.h>
  36 #include <sys/stat.h>
  37 #include <sys/ioctl.h>
  38 #ifdef HAVE_INOTIFY
  39 #include <sys/inotify.h>
  40 #endif
  41
  42 #include "udev.h"
  43
  44 #define UDEVD_PRIORITY                  -4
  45 #define UDEV_PRIORITY                   -2
  46
  47 /* maximum limit of forked childs */
  48 #define UDEVD_MAX_CHILDS                256
  49
  50 static int debug;
  51
  52 static void log_fn(struct udev *udev, int priority,
  53                    const char *file, int line, const char *fn,
  54                    const char *format, va_list args)
  55 {
  56         if (debug) {
  57                 fprintf(stderr, "[%d] %s: ", (int) getpid(), fn);
  58                 vfprintf(stderr, format, args);
  59         } else {
  60                 vsyslog(priority, format, args);
  61         }
  62 }
  63
  64 static void reap_sigchilds(void);
  65
  66 static int debug_trace;
  67 static struct udev_rules *rules;
  68 static struct udev_ctrl *udev_ctrl;
  69 static struct udev_monitor *kernel_monitor;
  70 static volatile int sigchilds_waiting;
  71 static volatile int udev_exit;
  72 static volatile int reload_config;
  73 static volatile int signal_received;
  74 static volatile pid_t settle_pid;
  75 static int run_exec_q;
  76 static int stop_exec_q;
  77 static int max_childs;
  78 static int childs;
  79 static struct udev_list_node event_list;
  80
  81 enum event_state {
  82         EVENT_QUEUED,
  83         EVENT_FINISHED,
  84         EVENT_FAILED,
  85 };
  86
  87 static struct udev_event *node_to_event(struct udev_list_node *node)
  88 {
  89         char *event;
  90
  91         event = (char *)node;
  92         event -= offsetof(struct udev_event, node);
  93         return (struct udev_event *)event;
  94 }
  95
  96 static void export_event_state(struct udev_event *event, enum event_state state)
  97 {
  98         char filename[UTIL_PATH_SIZE];
  99         char filename_failed[UTIL_PATH_SIZE];
 100         size_t start;
 101
 102         /* location of queue file */
 103         snprintf(filename, sizeof(filename), "%s/.udev/queue/%llu",
 104                  udev_get_dev_path(event->udev), udev_device_get_seqnum(event->dev));
 105
 106         /* location of failed file */
 107         util_strlcpy(filename_failed, udev_get_dev_path(event->udev), sizeof(filename_failed));
 108         util_strlcat(filename_failed, "/", sizeof(filename_failed));
 109         start = util_strlcat(filename_failed, ".udev/failed/", sizeof(filename_failed));
 110         util_strlcat(filename_failed, udev_device_get_devpath(event->dev), sizeof(filename_failed));
 111         util_path_encode(&filename_failed[start], sizeof(filename_failed) - start);
 112
 113         switch (state) {
 114         case EVENT_QUEUED:
 115                 if(unlink(filename_failed) == 0)
 116                         util_delete_path(event->udev, filename_failed);
 117                 util_create_path(event->udev, filename);
 118                 udev_selinux_setfscreatecon(event->udev, filename, S_IFLNK);
 119                 symlink(udev_device_get_devpath(event->dev), filename);
 120                 udev_selinux_resetfscreatecon(event->udev);
 121                 break;
 122         case EVENT_FINISHED:
 123                 if (udev_device_get_devpath_old(event->dev) != NULL) {
 124                         /* "move" event - rename failed file to current name, do not delete failed */
 125                         char filename_failed_old[UTIL_PATH_SIZE];
 126
 127                         util_strlcpy(filename_failed_old, udev_get_dev_path(event->udev), sizeof(filename_failed_old));
 128                         util_strlcat(filename_failed_old, "/", sizeof(filename_failed_old));
 129                         start = util_strlcat(filename_failed_old, ".udev/failed/", sizeof(filename_failed_old));
 130                         util_strlcat(filename_failed_old, udev_device_get_devpath_old(event->dev), sizeof(filename_failed_old));
 131                         util_path_encode(&filename_failed_old[start], sizeof(filename) - start);
 132
 133                         if (rename(filename_failed_old, filename_failed) == 0)
 134                                 info(event->udev, "renamed devpath, moved failed state of '%s' to %s'\n",
 135                                      udev_device_get_devpath_old(event->dev), udev_device_get_devpath(event->dev));
 136                 } else {
 137                         if (unlink(filename_failed) == 0)
 138                                 util_delete_path(event->udev, filename_failed);
 139                 }
 140
 141                 unlink(filename);
 142
 143                 /* clean up possibly empty queue directory */
 144                 if (udev_list_is_empty(&event_list))
 145                         util_delete_path(event->udev, filename);
 146                 break;
 147         case EVENT_FAILED:
 148                 /* move failed event to the failed directory */
 149                 util_create_path(event->udev, filename_failed);
 150                 rename(filename, filename_failed);
 151
 152                 /* clean up possibly empty queue directory */
 153                 if (udev_list_is_empty(&event_list))
 154                         util_delete_path(event->udev, filename);
 155                 break;
 156         }
 157
 158         return;
 159 }
 160
 161 static void event_queue_delete(struct udev_event *event)
 162 {
 163         udev_list_node_remove(&event->node);
 164
 165         /* mark as failed, if "add" event returns non-zero */
 166         if (event->exitstatus && strcmp(udev_device_get_action(event->dev), "add") == 0)
 167                 export_event_state(event, EVENT_FAILED);
 168         else
 169                 export_event_state(event, EVENT_FINISHED);
 170
 171         udev_device_unref(event->dev);
 172         udev_event_unref(event);
 173 }
 174
 175 static void asmlinkage event_sig_handler(int signum)
 176 {
 177         if (signum == SIGALRM)
 178                 exit(1);
 179 }
 180
 181 static void event_fork(struct udev_event *event)
 182 {
 183         pid_t pid;
 184         struct sigaction act;
 185         int err;
 186
 187         if (debug_trace) {
 188                 event->trace = 1;
 189                 fprintf(stderr, "fork %s (%llu)\n",
 190                        udev_device_get_syspath(event->dev),
 191                        udev_device_get_seqnum(event->dev));
 192         }
 193
 194         pid = fork();
 195         switch (pid) {
 196         case 0:
 197                 /* child */
 198                 udev_monitor_unref(kernel_monitor);
 199                 udev_ctrl_unref(udev_ctrl);
 200                 logging_close();
 201                 logging_init("udevd-event");
 202                 setpriority(PRIO_PROCESS, 0, UDEV_PRIORITY);
 203
 204                 /* set signal handlers */
 205                 memset(&act, 0x00, sizeof(act));
 206                 act.sa_handler = (void (*)(int)) event_sig_handler;
 207                 sigemptyset (&act.sa_mask);
 208                 act.sa_flags = 0;
 209                 sigaction(SIGALRM, &act, NULL);
 210
 211                 /* reset to default */
 212                 act.sa_handler = SIG_DFL;
 213                 sigaction(SIGINT, &act, NULL);
 214                 sigaction(SIGTERM, &act, NULL);
 215                 sigaction(SIGCHLD, &act, NULL);
 216                 sigaction(SIGHUP, &act, NULL);
 217
 218                 /* set timeout to prevent hanging processes */
 219                 alarm(UDEV_EVENT_TIMEOUT);
 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                         udev_watch_begin(event->udev, event->dev);
 235                         udev_device_update_db(event->dev);
 236                 }
 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
 520         settle_pid = udev_ctrl_get_settle(ctrl_msg);
 521         if (settle_pid > 0) {
 522                 info(udev, "udevd message (SETTLE) received\n");
 523         }
 524         udev_ctrl_msg_unref(ctrl_msg);
 525 }
 526
 527 /* read inotify messages */
 528 static int handle_inotify(struct udev *udev)
 529 {
 530         int nbytes, pos;
 531         char *buf;
 532         struct inotify_event *ev;
 533
 534         if ((ioctl(inotify_fd, FIONREAD, &nbytes) < 0) || (nbytes <= 0))
 535                 return 0;
 536
 537         buf = malloc(nbytes);
 538         if (buf == NULL) {
 539                 err(udev, "error getting buffer for inotify, disable watching\n");
 540                 close(inotify_fd);
 541                 inotify_fd = -1;
 542                 return 0;
 543         }
 544
 545         read(inotify_fd, buf, nbytes);
 546
 547         for (pos = 0; pos < nbytes; pos += sizeof(struct inotify_event) + ev->len) {
 548                 struct udev_device *dev;
 549
 550                 ev = (struct inotify_event *)(buf + pos);
 551                 if (ev->len) {
 552                         dbg(udev, "inotify event: %x for %s\n", ev->mask, ev->name);
 553                         reload_config = 1;
 554                         continue;
 555                 }
 556
 557                 dev = udev_watch_lookup(udev, ev->wd);
 558                 if (dev != NULL) {
 559                         dbg(udev, "inotify event: %x for %s\n", ev->mask, udev_device_get_devnode(dev));
 560                         if (ev->mask & IN_CLOSE_WRITE) {
 561                                 char filename[UTIL_PATH_SIZE];
 562                                 int fd;
 563
 564                                 info(udev, "device %s closed, synthesising 'change'\n", udev_device_get_devnode(dev));
 565                                 util_strlcpy(filename, udev_device_get_syspath(dev), sizeof(filename));
 566                                 util_strlcat(filename, "/uevent", sizeof(filename));
 567                                 fd = open(filename, O_WRONLY);
 568                                 if (fd < 0 || write(fd, "change", 6) < 0)
 569                                         info(udev, "error writing uevent: %m\n");
 570                                 close(fd);
 571                         }
 572                         if (ev->mask & IN_IGNORED)
 573                                 udev_watch_end(udev, dev);
 574
 575                         udev_device_unref(dev);
 576                 }
 577
 578         }
 579
 580         free (buf);
 581         return 0;
 582 }
 583
 584 static void asmlinkage sig_handler(int signum)
 585 {
 586         switch (signum) {
 587                 case SIGINT:
 588                 case SIGTERM:
 589                         udev_exit = 1;
 590                         break;
 591                 case SIGCHLD:
 592                         /* set flag, then write to pipe if needed */
 593                         sigchilds_waiting = 1;
 594                         break;
 595                 case SIGHUP:
 596                         reload_config = 1;
 597                         break;
 598         }
 599
 600         signal_received = 1;
 601 }
 602
 603 static void udev_done(int pid, int exitstatus)
 604 {
 605         struct udev_list_node *loop;
 606
 607         /* find event associated with pid and delete it */
 608         udev_list_node_foreach(loop, &event_list) {
 609                 struct udev_event *loop_event = node_to_event(loop);
 610
 611                 if (loop_event->pid == pid) {
 612                         info(loop_event->udev, "seq %llu cleanup, pid [%d], status %i, %ld seconds old\n",
 613                              udev_device_get_seqnum(loop_event->dev), loop_event->pid,
 614                              exitstatus, time(NULL) - loop_event->queue_time);
 615                         loop_event->exitstatus = exitstatus;
 616                         if (debug_trace)
 617                                 fprintf(stderr, "exit %s (%llu)\n",
 618                                        udev_device_get_syspath(loop_event->dev),
 619                                        udev_device_get_seqnum(loop_event->dev));
 620                         event_queue_delete(loop_event);
 621                         childs--;
 622
 623                         /* there may be dependent events waiting */
 624                         run_exec_q = 1;
 625                         return;
 626                 }
 627         }
 628 }
 629
 630 static void reap_sigchilds(void)
 631 {
 632         pid_t pid;
 633         int status;
 634
 635         while (1) {
 636                 pid = waitpid(-1, &status, WNOHANG);
 637                 if (pid <= 0)
 638                         break;
 639                 if (WIFEXITED(status))
 640                         status = WEXITSTATUS(status);
 641                 else if (WIFSIGNALED(status))
 642                         status = WTERMSIG(status) + 128;
 643                 else
 644                         status = 0;
 645                 udev_done(pid, status);
 646         }
 647 }
 648
 649 static void cleanup_queue_dir(struct udev *udev)
 650 {
 651         char dirname[UTIL_PATH_SIZE];
 652         char filename[UTIL_PATH_SIZE];
 653         DIR *dir;
 654
 655         util_strlcpy(filename, udev_get_dev_path(udev), sizeof(filename));
 656         util_strlcat(filename, "/.udev/uevent_seqnum", sizeof(filename));
 657         unlink(filename);
 658
 659         util_strlcpy(dirname, udev_get_dev_path(udev), sizeof(dirname));
 660         util_strlcat(dirname, "/.udev/queue", sizeof(dirname));
 661         dir = opendir(dirname);
 662         if (dir != NULL) {
 663                 while (1) {
 664                         struct dirent *dent;
 665
 666                         dent = readdir(dir);
 667                         if (dent == NULL || dent->d_name[0] == '\0')
 668                                 break;
 669                         if (dent->d_name[0] == '.')
 670                                 continue;
 671                         util_strlcpy(filename, dirname, sizeof(filename));
 672                         util_strlcat(filename, "/", sizeof(filename));
 673                         util_strlcat(filename, dent->d_name, sizeof(filename));
 674                         unlink(filename);
 675                 }
 676                 closedir(dir);
 677                 rmdir(dirname);
 678         }
 679 }
 680
 681 static void export_initial_seqnum(struct udev *udev)
 682 {
 683         char filename[UTIL_PATH_SIZE];
 684         int fd;
 685         char seqnum[32];
 686         ssize_t len = 0;
 687
 688         util_strlcpy(filename, udev_get_sys_path(udev), sizeof(filename));
 689         util_strlcat(filename, "/kernel/uevent_seqnum", sizeof(filename));
 690         fd = open(filename, O_RDONLY);
 691         if (fd >= 0) {
 692                 len = read(fd, seqnum, sizeof(seqnum)-1);
 693                 close(fd);
 694         }
 695         if (len <= 0) {
 696                 strcpy(seqnum, "0\n");
 697                 len = 3;
 698         }
 699         util_strlcpy(filename, udev_get_dev_path(udev), sizeof(filename));
 700         util_strlcat(filename, "/.udev/uevent_seqnum", sizeof(filename));
 701         util_create_path(udev, filename);
 702         fd = open(filename, O_WRONLY|O_TRUNC|O_CREAT, 0644);
 703         if (fd >= 0) {
 704                 write(fd, seqnum, len);
 705                 close(fd);
 706         }
 707 }
 708
 709 int main(int argc, char *argv[])
 710 {
 711         struct udev *udev;
 712         int fd;
 713         struct sigaction act;
 714         const char *value;
 715         int daemonize = 0;
 716         int resolve_names = 1;
 717         static const struct option options[] = {
 718                 { "daemon", no_argument, NULL, 'd' },
 719                 { "debug-trace", no_argument, NULL, 't' },
 720                 { "debug", no_argument, NULL, 'D' },
 721                 { "help", no_argument, NULL, 'h' },
 722                 { "version", no_argument, NULL, 'V' },
 723                 { "resolve-names", required_argument, NULL, 'N' },
 724                 {}
 725         };
 726         int rc = 1;
 727
 728         udev = udev_new();
 729         if (udev == NULL)
 730                 goto exit;
 731
 732         logging_init("udevd");
 733         udev_set_log_fn(udev, log_fn);
 734         info(udev, "version %s\n", VERSION);
 735         udev_selinux_init(udev);
 736
 737         while (1) {
 738                 int option;
 739
 740                 option = getopt_long(argc, argv, "dDthV", options, NULL);
 741                 if (option == -1)
 742                         break;
 743
 744                 switch (option) {
 745                 case 'd':
 746                         daemonize = 1;
 747                         break;
 748                 case 't':
 749                         debug_trace = 1;
 750                         break;
 751                 case 'D':
 752                         debug = 1;
 753                         if (udev_get_log_priority(udev) < LOG_INFO)
 754                                 udev_set_log_priority(udev, LOG_INFO);
 755                         break;
 756                 case 'N':
 757                         if (strcmp (optarg, "early") == 0) {
 758                                 resolve_names = 1;
 759                         } else if (strcmp (optarg, "late") == 0) {
 760                                 resolve_names = 0;
 761                         } else if (strcmp (optarg, "never") == 0) {
 762                                 resolve_names = -1;
 763                         } else {
 764                                 fprintf(stderr, "resolve-names must be early, late or never\n");
 765                                 err(udev, "resolve-names must be early, late or never\n");
 766                                 goto exit;
 767                         }
 768                         break;
 769                 case 'h':
 770                         printf("Usage: udevd [--help] [--daemon] [--debug-trace] [--debug] "
 771                                "[--resolve-names=early|late|never] [--version]\n");
 772                         goto exit;
 773                 case 'V':
 774                         printf("%s\n", VERSION);
 775                         goto exit;
 776                 default:
 777                         goto exit;
 778                 }
 779         }
 780
 781         if (getuid() != 0) {
 782                 fprintf(stderr, "root privileges required\n");
 783                 err(udev, "root privileges required\n");
 784                 goto exit;
 785         }
 786
 787         /* make sure std{in,out,err} fd's are in a sane state */
 788         fd = open("/dev/null", O_RDWR);
 789         if (fd < 0) {
 790                 fprintf(stderr, "cannot open /dev/null\n");
 791                 err(udev, "cannot open /dev/null\n");
 792         }
 793         if (write(STDOUT_FILENO, 0, 0) < 0)
 794                 dup2(fd, STDOUT_FILENO);
 795         if (write(STDERR_FILENO, 0, 0) < 0)
 796                 dup2(fd, STDERR_FILENO);
 797
 798         /* init control socket, bind() ensures, that only one udevd instance is running */
 799         udev_ctrl = udev_ctrl_new_from_socket(udev, UDEV_CTRL_SOCK_PATH);
 800         if (udev_ctrl == NULL) {
 801                 fprintf(stderr, "error initializing control socket");
 802                 err(udev, "error initializing udevd socket");
 803                 rc = 1;
 804                 goto exit;
 805         }
 806
 807         if (udev_ctrl_enable_receiving(udev_ctrl) < 0) {
 808                 fprintf(stderr, "error binding control socket, seems udevd is already running\n");
 809                 err(udev, "error binding control socket, seems udevd is already running\n");
 810                 rc = 1;
 811                 goto exit;
 812         }
 813
 814         kernel_monitor = udev_monitor_new_from_netlink(udev);
 815         if (kernel_monitor == NULL || udev_monitor_enable_receiving(kernel_monitor) < 0) {
 816                 fprintf(stderr, "error initializing netlink socket\n");
 817                 err(udev, "error initializing netlink socket\n");
 818                 rc = 3;
 819                 goto exit;
 820         }
 821         udev_monitor_set_receive_buffer_size(kernel_monitor, 128*1024*1024);
 822
 823         rules = udev_rules_new(udev, resolve_names);
 824         if (rules == NULL) {
 825                 err(udev, "error reading rules\n");
 826                 goto exit;
 827         }
 828         udev_list_init(&event_list);
 829         cleanup_queue_dir(udev);
 830         export_initial_seqnum(udev);
 831
 832         if (daemonize) {
 833                 pid_t pid;
 834
 835                 pid = fork();
 836                 switch (pid) {
 837                 case 0:
 838                         dbg(udev, "daemonized fork running\n");
 839                         break;
 840                 case -1:
 841                         err(udev, "fork of daemon failed: %m\n");
 842                         rc = 4;
 843                         goto exit;
 844                 default:
 845                         dbg(udev, "child [%u] running, parent exits\n", pid);
 846                         rc = 0;
 847                         goto exit;
 848                 }
 849         }
 850
 851         /* redirect std{out,err} */
 852         if (!debug && !debug_trace) {
 853                 dup2(fd, STDIN_FILENO);
 854                 dup2(fd, STDOUT_FILENO);
 855                 dup2(fd, STDERR_FILENO);
 856         }
 857         if (fd > STDERR_FILENO)
 858                 close(fd);
 859
 860         /* set scheduling priority for the daemon */
 861         setpriority(PRIO_PROCESS, 0, UDEVD_PRIORITY);
 862
 863         chdir("/");
 864         umask(022);
 865         setsid();
 866
 867         /* OOM_DISABLE == -17 */
 868         fd = open("/proc/self/oom_adj", O_RDWR);
 869         if (fd < 0)
 870                 err(udev, "error disabling OOM: %m\n");
 871         else {
 872                 write(fd, "-17", 3);
 873                 close(fd);
 874         }
 875
 876         fd = open("/dev/kmsg", O_WRONLY);
 877         if (fd > 0) {
 878                 const char *ver_str = "<6>udev: starting version " VERSION "\n";
 879                 char path[UTIL_PATH_SIZE];
 880                 struct stat statbuf;
 881
 882                 write(fd, ver_str, strlen(ver_str));
 883                 util_strlcpy(path, udev_get_sys_path(udev), sizeof(path));
 884                 util_strlcat(path, "/class/mem/null", sizeof(path));
 885                 if (lstat(path, &statbuf) == 0) {
 886                         if (S_ISDIR(statbuf.st_mode)) {
 887                                 const char *depr_str =
 888                                         "<6>udev: deprecated sysfs layout; update the kernel or "
 889                                         "disable CONFIG_SYSFS_DEPRECATED; some udev features will "
 890                                         "not work correctly\n";
 891
 892                                 write(fd, depr_str, strlen(depr_str));
 893                         }
 894                 }
 895                 close(fd);
 896         }
 897
 898         /* set signal handlers */
 899         memset(&act, 0x00, sizeof(struct sigaction));
 900         act.sa_handler = (void (*)(int)) sig_handler;
 901         sigemptyset(&act.sa_mask);
 902         act.sa_flags = SA_RESTART;
 903         sigaction(SIGINT, &act, NULL);
 904         sigaction(SIGTERM, &act, NULL);
 905         sigaction(SIGCHLD, &act, NULL);
 906         sigaction(SIGHUP, &act, NULL);
 907
 908         /* watch rules directory */
 909         udev_watch_init(udev);
 910         if (inotify_fd >= 0) {
 911                 if (udev_get_rules_path(udev) != NULL) {
 912                         inotify_add_watch(inotify_fd, udev_get_rules_path(udev),
 913                                           IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
 914                 } else {
 915                         char filename[UTIL_PATH_SIZE];
 916
 917                         inotify_add_watch(inotify_fd, UDEV_PREFIX "/lib/udev/rules.d",
 918                                           IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
 919                         inotify_add_watch(inotify_fd, SYSCONFDIR "/udev/rules.d",
 920                                           IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
 921
 922                         /* watch dynamic rules directory */
 923                         util_strlcpy(filename, udev_get_dev_path(udev), sizeof(filename));
 924                         util_strlcat(filename, "/.udev/rules.d", sizeof(filename));
 925                         inotify_add_watch(inotify_fd, filename,
 926                                           IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
 927                 }
 928
 929                 udev_watch_restore(udev);
 930         }
 931
 932         /* in trace mode run one event after the other */
 933         if (debug_trace) {
 934                 max_childs = 1;
 935         } else {
 936                 int memsize = mem_size_mb();
 937                 if (memsize > 0)
 938                         max_childs = 128 + (memsize / 4);
 939                 else
 940                         max_childs = UDEVD_MAX_CHILDS;
 941         }
 942         /* possibly overwrite maximum limit of executed events */
 943         value = getenv("UDEVD_MAX_CHILDS");
 944         if (value)
 945                 max_childs = strtoul(value, NULL, 10);
 946         info(udev, "initialize max_childs to %u\n", max_childs);
 947
 948         while (!udev_exit) {
 949                 sigset_t blocked_mask, orig_mask;
 950                 struct pollfd pfd[4];
 951                 struct pollfd *ctrl_poll, *monitor_poll, *inotify_poll = NULL;
 952                 int nfds = 0;
 953                 int fdcount;
 954
 955                 sigfillset(&blocked_mask);
 956                 sigprocmask(SIG_SETMASK, &blocked_mask, &orig_mask);
 957                 if (signal_received) {
 958                         sigprocmask(SIG_SETMASK, &orig_mask, NULL);
 959                         goto handle_signals;
 960                 }
 961
 962                 ctrl_poll = &pfd[nfds++];
 963                 ctrl_poll->fd = udev_ctrl_get_fd(udev_ctrl);
 964                 ctrl_poll->events = POLLIN;
 965
 966                 monitor_poll = &pfd[nfds++];
 967                 monitor_poll->fd = udev_monitor_get_fd(kernel_monitor);
 968                 monitor_poll->events = POLLIN;
 969
 970                 if (inotify_fd >= 0) {
 971                         inotify_poll = &pfd[nfds++];
 972                         inotify_poll->fd = inotify_fd;
 973                         inotify_poll->events = POLLIN;
 974                 }
 975
 976                 fdcount = ppoll(pfd, nfds, NULL, &orig_mask);
 977                 sigprocmask(SIG_SETMASK, &orig_mask, NULL);
 978                 if (fdcount < 0) {
 979                         if (errno == EINTR)
 980                                 goto handle_signals;
 981                         err(udev, "error in select: %m\n");
 982                         continue;
 983                 }
 984
 985                 /* get control message */
 986                 if (ctrl_poll->revents & POLLIN)
 987                         handle_ctrl_msg(udev_ctrl);
 988
 989                 /* get kernel uevent */
 990                 if (monitor_poll->revents & POLLIN) {
 991                         struct udev_device *dev;
 992
 993                         dev = udev_monitor_receive_device(kernel_monitor);
 994                         if (dev != NULL) {
 995                                 struct udev_event *event;
 996
 997                                 event = udev_event_new(dev);
 998                                 if (event != NULL)
 999                                         event_queue_insert(event);
1000                                 else
1001                                         udev_device_unref(dev);
1002                         }
1003                 }
1004
1005                 /* rules directory inotify watch */
1006                 if (inotify_poll && (inotify_poll->revents & POLLIN))
1007                         handle_inotify(udev);
1008
1009 handle_signals:
1010                 signal_received = 0;
1011
1012                 /* rules changed, set by inotify or a HUP signal */
1013                 if (reload_config) {
1014                         struct udev_rules *rules_new;
1015
1016                         reload_config = 0;
1017                         rules_new = udev_rules_new(udev, resolve_names);
1018                         if (rules_new != NULL) {
1019                                 udev_rules_unref(rules);
1020                                 rules = rules_new;
1021                         }
1022                 }
1023
1024                 if (sigchilds_waiting) {
1025                         sigchilds_waiting = 0;
1026                         reap_sigchilds();
1027                 }
1028
1029                 if (run_exec_q) {
1030                         run_exec_q = 0;
1031                         if (!stop_exec_q)
1032                                 event_queue_manager(udev);
1033                 }
1034
1035                 if (settle_pid > 0) {
1036                         kill(settle_pid, SIGUSR1);
1037                         settle_pid = 0;
1038                 }
1039         }
1040         cleanup_queue_dir(udev);
1041         rc = 0;
1042 exit:
1043         udev_rules_unref(rules);
1044         udev_ctrl_unref(udev_ctrl);
1045         if (inotify_fd >= 0)
1046                 close(inotify_fd);
1047         udev_monitor_unref(kernel_monitor);
1048         udev_selinux_exit(udev);
1049         udev_unref(udev);
1050         logging_close();
1051         return rc;
1052 }