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_ctrl_unref(udev_ctrl);
 199                 logging_close();
 200                 logging_init("udevd-event");
 201                 setpriority(PRIO_PROCESS, 0, UDEV_PRIORITY);
 202
 203                 /* set signal handlers */
 204                 memset(&act, 0x00, sizeof(act));
 205                 act.sa_handler = (void (*)(int)) event_sig_handler;
 206                 sigemptyset (&act.sa_mask);
 207                 act.sa_flags = 0;
 208                 sigaction(SIGALRM, &act, NULL);
 209
 210                 /* reset to default */
 211                 act.sa_handler = SIG_DFL;
 212                 sigaction(SIGINT, &act, NULL);
 213                 sigaction(SIGTERM, &act, NULL);
 214                 sigaction(SIGCHLD, &act, NULL);
 215                 sigaction(SIGHUP, &act, NULL);
 216
 217                 /* set timeout to prevent hanging processes */
 218                 alarm(UDEV_EVENT_TIMEOUT);
 219
 220                 /* apply rules, create node, symlinks */
 221                 err = udev_event_execute_rules(event, rules);
 222
 223                 /* rules may change/disable the timeout */
 224                 if (udev_device_get_event_timeout(event->dev) >= 0)
 225                         alarm(udev_device_get_event_timeout(event->dev));
 226
 227                 /* execute RUN= */
 228                 if (err == 0 && !event->ignore_device && udev_get_run(event->udev))
 229                         udev_event_execute_run(event);
 230
 231                 /* apply/restore inotify watch */
 232                 if (err == 0 && event->inotify_watch) {
 233                         udev_watch_begin(event->udev, event->dev);
 234                         udev_device_update_db(event->dev);
 235                 }
 236
 237                 /* send processed event back to the kernel netlink socket */
 238                 udev_monitor_send_device(kernel_monitor, event->dev);
 239
 240                 info(event->udev, "seq %llu exit with %i\n", udev_device_get_seqnum(event->dev), err);
 241                 logging_close();
 242                 if (err != 0)
 243                         exit(1);
 244                 exit(0);
 245         case -1:
 246                 err(event->udev, "fork of child failed: %m\n");
 247                 event_queue_delete(event);
 248                 break;
 249         default:
 250                 /* get SIGCHLD in main loop */
 251                 info(event->udev, "seq %llu forked, pid [%d], '%s' '%s', %ld seconds old\n",
 252                      udev_device_get_seqnum(event->dev),
 253                      pid,
 254                      udev_device_get_action(event->dev),
 255                      udev_device_get_subsystem(event->dev),
 256                      time(NULL) - event->queue_time);
 257                 event->pid = pid;
 258                 childs++;
 259         }
 260 }
 261
 262 static void event_queue_insert(struct udev_event *event)
 263 {
 264         char filename[UTIL_PATH_SIZE];
 265         int fd;
 266
 267         event->queue_time = time(NULL);
 268
 269         export_event_state(event, EVENT_QUEUED);
 270         info(event->udev, "seq %llu queued, '%s' '%s'\n", udev_device_get_seqnum(event->dev),
 271              udev_device_get_action(event->dev), udev_device_get_subsystem(event->dev));
 272
 273         util_strlcpy(filename, udev_get_dev_path(event->udev), sizeof(filename));
 274         util_strlcat(filename, "/.udev/uevent_seqnum", sizeof(filename));
 275         fd = open(filename, O_WRONLY|O_TRUNC|O_CREAT, 0644);
 276         if (fd >= 0) {
 277                 char str[32];
 278                 int len;
 279
 280                 len = sprintf(str, "%llu\n", udev_device_get_seqnum(event->dev));
 281                 write(fd, str, len);
 282                 close(fd);
 283         }
 284
 285
 286         udev_list_node_append(&event->node, &event_list);
 287         run_exec_q = 1;
 288
 289         /* run all events with a timeout set immediately */
 290         if (udev_device_get_timeout(event->dev) > 0) {
 291                 event_fork(event);
 292                 return;
 293         }
 294 }
 295
 296 static int mem_size_mb(void)
 297 {
 298         FILE *f;
 299         char buf[4096];
 300         long int memsize = -1;
 301
 302         f = fopen("/proc/meminfo", "r");
 303         if (f == NULL)
 304                 return -1;
 305
 306         while (fgets(buf, sizeof(buf), f) != NULL) {
 307                 long int value;
 308
 309                 if (sscanf(buf, "MemTotal: %ld kB", &value) == 1) {
 310                         memsize = value / 1024;
 311                         break;
 312                 }
 313         }
 314
 315         fclose(f);
 316         return memsize;
 317 }
 318
 319 static int compare_devpath(const char *running, const char *waiting)
 320 {
 321         int i = 0;
 322
 323         while (running[i] != '\0' && running[i] == waiting[i])
 324                 i++;
 325
 326         /* identical device event found */
 327         if (running[i] == '\0' && waiting[i] == '\0')
 328                 return 1;
 329
 330         /* parent device event found */
 331         if (running[i] == '\0' && waiting[i] == '/')
 332                 return 2;
 333
 334         /* child device event found */
 335         if (running[i] == '/' && waiting[i] == '\0')
 336                 return 3;
 337
 338         /* no matching event */
 339         return 0;
 340 }
 341
 342 /* lookup event for identical, parent, child, or physical device */
 343 static int devpath_busy(struct udev_event *event)
 344 {
 345         struct udev_list_node *loop;
 346
 347         if (event->delaying_seqnum > 0) {
 348         }
 349         /* check if queue contains events we depend on */
 350         udev_list_node_foreach(loop, &event_list) {
 351                 struct udev_event *loop_event = node_to_event(loop);
 352
 353                 /* we already found a later event, earlier can not block us, no need to check again */
 354                 if (udev_device_get_seqnum(loop_event->dev) < event->delaying_seqnum)
 355                         continue;
 356
 357                 /* event we checked earlier still exists, no need to check again */
 358                 if (udev_device_get_seqnum(loop_event->dev) == event->delaying_seqnum)
 359                         return 2;
 360
 361                 /* found ourself, no later event can block us */
 362                 if (udev_device_get_seqnum(loop_event->dev) >= udev_device_get_seqnum(event->dev))
 363                         break;
 364
 365                 /* check our old name */
 366                 if (udev_device_get_devpath_old(event->dev) != NULL)
 367                         if (strcmp(udev_device_get_devpath(loop_event->dev), udev_device_get_devpath_old(event->dev)) == 0) {
 368                                 event->delaying_seqnum = udev_device_get_seqnum(loop_event->dev);
 369                                 return 3;
 370                         }
 371
 372                 /* check identical, parent, or child device event */
 373                 if (compare_devpath(udev_device_get_devpath(loop_event->dev), udev_device_get_devpath(event->dev)) != 0) {
 374                         dbg(event->udev, "%llu, device event still pending %llu (%s)\n",
 375                             udev_device_get_seqnum(event->dev),
 376                             udev_device_get_seqnum(loop_event->dev),
 377                             udev_device_get_devpath(loop_event->dev));
 378                         event->delaying_seqnum = udev_device_get_seqnum(loop_event->dev);
 379                         return 4;
 380                 }
 381
 382                 /* check for our major:minor number */
 383                 if (major(udev_device_get_devnum(event->dev)) > 0 &&
 384                     udev_device_get_devnum(loop_event->dev) == udev_device_get_devnum(event->dev) &&
 385                     strcmp(udev_device_get_subsystem(event->dev), udev_device_get_subsystem(loop_event->dev)) == 0) {
 386                         dbg(event->udev, "%llu, device event still pending %llu (%d:%d)\n",
 387                             udev_device_get_seqnum(event->dev),
 388                             udev_device_get_seqnum(loop_event->dev),
 389                             major(udev_device_get_devnum(loop_event->dev)), minor(udev_device_get_devnum(loop_event->dev)));
 390                         event->delaying_seqnum = udev_device_get_seqnum(loop_event->dev);
 391                         return 5;
 392                 }
 393
 394                 /* check physical device event (special case of parent) */
 395                 if (udev_device_get_physdevpath(event->dev) != NULL &&
 396                     strcmp(udev_device_get_action(event->dev), "add") == 0)
 397                         if (compare_devpath(udev_device_get_devpath(loop_event->dev),
 398                                             udev_device_get_physdevpath(event->dev)) != 0) {
 399                                 dbg(event->udev, "%llu, physical device event still pending %llu (%s)\n",
 400                                     udev_device_get_seqnum(event->dev),
 401                                     udev_device_get_seqnum(loop_event->dev),
 402                                     udev_device_get_devpath(loop_event->dev));
 403                                 event->delaying_seqnum = udev_device_get_seqnum(loop_event->dev);
 404                                 return 6;
 405                         }
 406         }
 407         return 0;
 408 }
 409
 410 /* serializes events for the identical and parent and child devices */
 411 static void event_queue_manager(struct udev *udev)
 412 {
 413         struct udev_list_node *loop;
 414         struct udev_list_node *tmp;
 415
 416 start_over:
 417         if (udev_list_is_empty(&event_list)) {
 418                 if (childs > 0) {
 419                         err(udev, "event list empty, but childs count is %i", childs);
 420                         childs = 0;
 421                 }
 422                 return;
 423         }
 424
 425         udev_list_node_foreach_safe(loop, tmp, &event_list) {
 426                 struct udev_event *loop_event = node_to_event(loop);
 427
 428                 if (childs >= max_childs) {
 429                         info(udev, "maximum number (%i) of childs reached\n", childs);
 430                         break;
 431                 }
 432
 433                 if (loop_event->pid != 0)
 434                         continue;
 435
 436                 /* do not start event if parent or child event is still running */
 437                 if (devpath_busy(loop_event) != 0) {
 438                         dbg(udev, "delay seq %llu (%s)\n",
 439                             udev_device_get_seqnum(loop_event->dev),
 440                             udev_device_get_devpath(loop_event->dev));
 441                         continue;
 442                 }
 443
 444                 event_fork(loop_event);
 445                 dbg(udev, "moved seq %llu to running list\n", udev_device_get_seqnum(loop_event->dev));
 446
 447                 /* retry if events finished in the meantime */
 448                 if (sigchilds_waiting) {
 449                         sigchilds_waiting = 0;
 450                         reap_sigchilds();
 451                         goto start_over;
 452                 }
 453         }
 454 }
 455
 456 /* receive the udevd message from userspace */
 457 static void handle_ctrl_msg(struct udev_ctrl *uctrl)
 458 {
 459         struct udev *udev = udev_ctrl_get_udev(uctrl);
 460         struct udev_ctrl_msg *ctrl_msg;
 461         const char *str;
 462         int i;
 463
 464         ctrl_msg = udev_ctrl_receive_msg(uctrl);
 465         if (ctrl_msg == NULL)
 466                 return;
 467
 468         i = udev_ctrl_get_set_log_level(ctrl_msg);
 469         if (i >= 0) {
 470                 info(udev, "udevd message (SET_LOG_PRIORITY) received, log_priority=%i\n", i);
 471                 udev_set_log_priority(udev, i);
 472         }
 473
 474         if (udev_ctrl_get_stop_exec_queue(ctrl_msg) > 0) {
 475                 info(udev, "udevd message (STOP_EXEC_QUEUE) received\n");
 476                 stop_exec_q = 1;
 477         }
 478
 479         if (udev_ctrl_get_start_exec_queue(ctrl_msg) > 0) {
 480                 info(udev, "udevd message (START_EXEC_QUEUE) received\n");
 481                 stop_exec_q = 0;
 482                 event_queue_manager(udev);
 483         }
 484
 485         if (udev_ctrl_get_reload_rules(ctrl_msg) > 0) {
 486                 info(udev, "udevd message (RELOAD_RULES) received\n");
 487                 reload_config = 1;
 488         }
 489
 490         str = udev_ctrl_get_set_env(ctrl_msg);
 491         if (str != NULL) {
 492                 char *key;
 493
 494                 key = strdup(str);
 495                 if (key != NULL) {
 496                         char *val;
 497
 498                         val = strchr(key, '=');
 499                         if (val != NULL) {
 500                                 val[0] = '\0';
 501                                 val = &val[1];
 502                                 if (val[0] == '\0') {
 503                                         info(udev, "udevd message (ENV) received, unset '%s'\n", key);
 504                                         udev_add_property(udev, key, NULL);
 505                                 } else {
 506                                         info(udev, "udevd message (ENV) received, set '%s=%s'\n", key, val);
 507                                         udev_add_property(udev, key, val);
 508                                 }
 509                         } else {
 510                                 err(udev, "wrong key format '%s'\n", key);
 511                         }
 512                         free(key);
 513                 }
 514         }
 515
 516         i = udev_ctrl_get_set_max_childs(ctrl_msg);
 517         if (i >= 0) {
 518                 info(udev, "udevd message (SET_MAX_CHILDS) received, max_childs=%i\n", i);
 519                 max_childs = i;
 520         }
 521
 522         settle_pid = udev_ctrl_get_settle(ctrl_msg);
 523         if (settle_pid > 0) {
 524                 info(udev, "udevd message (SETTLE) received\n");
 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 /* create the nodes the we depend on to properly start up */
 712 static void setup_initial_nodes(struct udev *udev)
 713 {
 714         struct udev_device *dev;
 715
 716         dev = udev_device_new_from_subsystem_sysname(udev, "mem", "null");
 717         if (dev != NULL) {
 718                 udev_node_mknod(dev, "null", makedev(0,0), 0666, 0, 0);
 719                 udev_device_unref(dev);
 720         }
 721         dev = udev_device_new_from_subsystem_sysname(udev, "mem", "kmsg");
 722         if (dev != NULL) {
 723                 udev_node_mknod(dev, "kmsg", makedev(0,0), 0660, 0, 0);
 724                 udev_device_unref(dev);
 725         }
 726         dev = udev_device_new_from_subsystem_sysname(udev, "tty", "console");
 727         if (dev != NULL) {
 728                 udev_node_mknod(dev, "console", makedev(0,0), 0600, 0, 0);
 729                 udev_device_unref(dev);
 730         }
 731 }
 732
 733 static void startup_log(struct udev *udev)
 734 {
 735         FILE *f;
 736         char path[UTIL_PATH_SIZE];
 737         struct stat statbuf;
 738
 739         f = fopen("/dev/kmsg", "w");
 740         if (f != NULL)
 741                 fprintf(f, "<6>udev: starting version " VERSION "\n");
 742
 743         util_strlcpy(path, udev_get_sys_path(udev), sizeof(path));
 744         util_strlcat(path, "/class/mem/null", sizeof(path));
 745         if (lstat(path, &statbuf) == 0 && S_ISDIR(statbuf.st_mode)) {
 746                 const char *depr_str =
 747                         "udev: missing sysfs features; please update the kernel "
 748                         "or disable the kernel's CONFIG_SYSFS_DEPRECATED option; "
 749                         "udev may fail to work correctly";
 750
 751                 if (f != NULL)
 752                         fprintf(f, "<3>%s\n", depr_str);
 753                 err(udev, "%s\n", depr_str);
 754                 sleep(3);
 755         }
 756
 757         if (f != NULL)
 758                 fclose(f);
 759 }
 760
 761 int main(int argc, char *argv[])
 762 {
 763         struct udev *udev;
 764         int fd;
 765         struct sigaction act;
 766         const char *value;
 767         int daemonize = 0;
 768         int resolve_names = 1;
 769         static const struct option options[] = {
 770                 { "daemon", no_argument, NULL, 'd' },
 771                 { "debug-trace", no_argument, NULL, 't' },
 772                 { "debug", no_argument, NULL, 'D' },
 773                 { "help", no_argument, NULL, 'h' },
 774                 { "version", no_argument, NULL, 'V' },
 775                 { "resolve-names", required_argument, NULL, 'N' },
 776                 {}
 777         };
 778         int rc = 1;
 779
 780         udev = udev_new();
 781         if (udev == NULL)
 782                 goto exit;
 783
 784         logging_init("udevd");
 785         udev_set_log_fn(udev, log_fn);
 786         info(udev, "version %s\n", VERSION);
 787         udev_selinux_init(udev);
 788
 789         while (1) {
 790                 int option;
 791
 792                 option = getopt_long(argc, argv, "dDthV", options, NULL);
 793                 if (option == -1)
 794                         break;
 795
 796                 switch (option) {
 797                 case 'd':
 798                         daemonize = 1;
 799                         break;
 800                 case 't':
 801                         debug_trace = 1;
 802                         break;
 803                 case 'D':
 804                         debug = 1;
 805                         if (udev_get_log_priority(udev) < LOG_INFO)
 806                                 udev_set_log_priority(udev, LOG_INFO);
 807                         break;
 808                 case 'N':
 809                         if (strcmp (optarg, "early") == 0) {
 810                                 resolve_names = 1;
 811                         } else if (strcmp (optarg, "late") == 0) {
 812                                 resolve_names = 0;
 813                         } else if (strcmp (optarg, "never") == 0) {
 814                                 resolve_names = -1;
 815                         } else {
 816                                 fprintf(stderr, "resolve-names must be early, late or never\n");
 817                                 err(udev, "resolve-names must be early, late or never\n");
 818                                 goto exit;
 819                         }
 820                         break;
 821                 case 'h':
 822                         printf("Usage: udevd [--help] [--daemon] [--debug-trace] [--debug] "
 823                                "[--resolve-names=early|late|never] [--version]\n");
 824                         goto exit;
 825                 case 'V':
 826                         printf("%s\n", VERSION);
 827                         goto exit;
 828                 default:
 829                         goto exit;
 830                 }
 831         }
 832
 833         if (getuid() != 0) {
 834                 fprintf(stderr, "root privileges required\n");
 835                 err(udev, "root privileges required\n");
 836                 goto exit;
 837         }
 838
 839         setup_initial_nodes(udev);
 840
 841         /* make sure std{in,out,err} fd's are in a sane state */
 842         fd = open("/dev/null", O_RDWR);
 843         if (fd < 0) {
 844                 fprintf(stderr, "cannot open /dev/null\n");
 845                 err(udev, "cannot open /dev/null\n");
 846         }
 847         if (write(STDOUT_FILENO, 0, 0) < 0)
 848                 dup2(fd, STDOUT_FILENO);
 849         if (write(STDERR_FILENO, 0, 0) < 0)
 850                 dup2(fd, STDERR_FILENO);
 851
 852         /* init control socket, bind() ensures, that only one udevd instance is running */
 853         udev_ctrl = udev_ctrl_new_from_socket(udev, UDEV_CTRL_SOCK_PATH);
 854         if (udev_ctrl == NULL) {
 855                 fprintf(stderr, "error initializing control socket");
 856                 err(udev, "error initializing udevd socket");
 857                 rc = 1;
 858                 goto exit;
 859         }
 860
 861         if (udev_ctrl_enable_receiving(udev_ctrl) < 0) {
 862                 fprintf(stderr, "error binding control socket, seems udevd is already running\n");
 863                 err(udev, "error binding control socket, seems udevd is already running\n");
 864                 rc = 1;
 865                 goto exit;
 866         }
 867
 868         kernel_monitor = udev_monitor_new_from_netlink(udev, "kernel");
 869         if (kernel_monitor == NULL || udev_monitor_enable_receiving(kernel_monitor) < 0) {
 870                 fprintf(stderr, "error initializing netlink socket\n");
 871                 err(udev, "error initializing netlink socket\n");
 872                 rc = 3;
 873                 goto exit;
 874         }
 875         udev_monitor_set_receive_buffer_size(kernel_monitor, 128*1024*1024);
 876
 877         rules = udev_rules_new(udev, resolve_names);
 878         if (rules == NULL) {
 879                 err(udev, "error reading rules\n");
 880                 goto exit;
 881         }
 882         udev_list_init(&event_list);
 883         cleanup_queue_dir(udev);
 884         export_initial_seqnum(udev);
 885
 886         if (daemonize) {
 887                 pid_t pid;
 888
 889                 pid = fork();
 890                 switch (pid) {
 891                 case 0:
 892                         dbg(udev, "daemonized fork running\n");
 893                         break;
 894                 case -1:
 895                         err(udev, "fork of daemon failed: %m\n");
 896                         rc = 4;
 897                         goto exit;
 898                 default:
 899                         dbg(udev, "child [%u] running, parent exits\n", pid);
 900                         rc = 0;
 901                         goto exit;
 902                 }
 903         }
 904
 905         /* redirect std{out,err} */
 906         if (!debug && !debug_trace) {
 907                 dup2(fd, STDIN_FILENO);
 908                 dup2(fd, STDOUT_FILENO);
 909                 dup2(fd, STDERR_FILENO);
 910         }
 911         if (fd > STDERR_FILENO)
 912                 close(fd);
 913
 914         /* set scheduling priority for the daemon */
 915         setpriority(PRIO_PROCESS, 0, UDEVD_PRIORITY);
 916
 917         chdir("/");
 918         umask(022);
 919         setsid();
 920
 921         /* OOM_DISABLE == -17 */
 922         fd = open("/proc/self/oom_adj", O_RDWR);
 923         if (fd < 0)
 924                 err(udev, "error disabling OOM: %m\n");
 925         else {
 926                 write(fd, "-17", 3);
 927                 close(fd);
 928         }
 929
 930         startup_log(udev);
 931
 932         /* set signal handlers */
 933         memset(&act, 0x00, sizeof(struct sigaction));
 934         act.sa_handler = (void (*)(int)) sig_handler;
 935         sigemptyset(&act.sa_mask);
 936         act.sa_flags = SA_RESTART;
 937         sigaction(SIGINT, &act, NULL);
 938         sigaction(SIGTERM, &act, NULL);
 939         sigaction(SIGCHLD, &act, NULL);
 940         sigaction(SIGHUP, &act, NULL);
 941
 942         /* watch rules directory */
 943         udev_watch_init(udev);
 944         if (inotify_fd >= 0) {
 945                 if (udev_get_rules_path(udev) != NULL) {
 946                         inotify_add_watch(inotify_fd, udev_get_rules_path(udev),
 947                                           IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
 948                 } else {
 949                         char filename[UTIL_PATH_SIZE];
 950
 951                         inotify_add_watch(inotify_fd, UDEV_PREFIX "/lib/udev/rules.d",
 952                                           IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
 953                         inotify_add_watch(inotify_fd, SYSCONFDIR "/udev/rules.d",
 954                                           IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
 955
 956                         /* watch dynamic rules directory */
 957                         util_strlcpy(filename, udev_get_dev_path(udev), sizeof(filename));
 958                         util_strlcat(filename, "/.udev/rules.d", sizeof(filename));
 959                         inotify_add_watch(inotify_fd, filename,
 960                                           IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
 961                 }
 962
 963                 udev_watch_restore(udev);
 964         }
 965
 966         /* in trace mode run one event after the other */
 967         if (debug_trace) {
 968                 max_childs = 1;
 969         } else {
 970                 int memsize = mem_size_mb();
 971                 if (memsize > 0)
 972                         max_childs = 128 + (memsize / 4);
 973                 else
 974                         max_childs = UDEVD_MAX_CHILDS;
 975         }
 976         /* possibly overwrite maximum limit of executed events */
 977         value = getenv("UDEVD_MAX_CHILDS");
 978         if (value)
 979                 max_childs = strtoul(value, NULL, 10);
 980         info(udev, "initialize max_childs to %u\n", max_childs);
 981
 982         while (!udev_exit) {
 983                 sigset_t blocked_mask, orig_mask;
 984                 struct pollfd pfd[4];
 985                 struct pollfd *ctrl_poll, *monitor_poll, *inotify_poll = NULL;
 986                 int nfds = 0;
 987                 int fdcount;
 988
 989                 sigfillset(&blocked_mask);
 990                 sigprocmask(SIG_SETMASK, &blocked_mask, &orig_mask);
 991                 if (signal_received) {
 992                         sigprocmask(SIG_SETMASK, &orig_mask, NULL);
 993                         goto handle_signals;
 994                 }
 995
 996                 ctrl_poll = &pfd[nfds++];
 997                 ctrl_poll->fd = udev_ctrl_get_fd(udev_ctrl);
 998                 ctrl_poll->events = POLLIN;
 999
1000                 monitor_poll = &pfd[nfds++];
1001                 monitor_poll->fd = udev_monitor_get_fd(kernel_monitor);
1002                 monitor_poll->events = POLLIN;
1003
1004                 if (inotify_fd >= 0) {
1005                         inotify_poll = &pfd[nfds++];
1006                         inotify_poll->fd = inotify_fd;
1007                         inotify_poll->events = POLLIN;
1008                 }
1009
1010                 fdcount = ppoll(pfd, nfds, NULL, &orig_mask);
1011                 sigprocmask(SIG_SETMASK, &orig_mask, NULL);
1012                 if (fdcount < 0) {
1013                         if (errno == EINTR)
1014                                 goto handle_signals;
1015                         err(udev, "error in select: %m\n");
1016                         continue;
1017                 }
1018
1019                 /* get control message */
1020                 if (ctrl_poll->revents & POLLIN)
1021                         handle_ctrl_msg(udev_ctrl);
1022
1023                 /* get kernel uevent */
1024                 if (monitor_poll->revents & POLLIN) {
1025                         struct udev_device *dev;
1026
1027                         dev = udev_monitor_receive_device(kernel_monitor);
1028                         if (dev != NULL) {
1029                                 struct udev_event *event;
1030
1031                                 event = udev_event_new(dev);
1032                                 if (event != NULL)
1033                                         event_queue_insert(event);
1034                                 else
1035                                         udev_device_unref(dev);
1036                         }
1037                 }
1038
1039                 /* rules directory inotify watch */
1040                 if (inotify_poll && (inotify_poll->revents & POLLIN))
1041                         handle_inotify(udev);
1042
1043 handle_signals:
1044                 signal_received = 0;
1045
1046                 /* rules changed, set by inotify or a HUP signal */
1047                 if (reload_config) {
1048                         struct udev_rules *rules_new;
1049
1050                         reload_config = 0;
1051                         rules_new = udev_rules_new(udev, resolve_names);
1052                         if (rules_new != NULL) {
1053                                 udev_rules_unref(rules);
1054                                 rules = rules_new;
1055                         }
1056                 }
1057
1058                 if (sigchilds_waiting) {
1059                         sigchilds_waiting = 0;
1060                         reap_sigchilds();
1061                 }
1062
1063                 if (run_exec_q) {
1064                         run_exec_q = 0;
1065                         if (!stop_exec_q)
1066                                 event_queue_manager(udev);
1067                 }
1068
1069                 if (settle_pid > 0) {
1070                         kill(settle_pid, SIGUSR1);
1071                         settle_pid = 0;
1072                 }
1073         }
1074         cleanup_queue_dir(udev);
1075         rc = 0;
1076 exit:
1077         udev_rules_unref(rules);
1078         udev_ctrl_unref(udev_ctrl);
1079         if (inotify_fd >= 0)
1080                 close(inotify_fd);
1081         udev_monitor_unref(kernel_monitor);
1082         udev_selinux_exit(udev);
1083         udev_unref(udev);
1084         logging_close();
1085         return rc;
1086 }