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