udev/udevd.c

   1 /*
   2  * Copyright (C) 2004-2009 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/prctl.h>
  34 #include <sys/socket.h>
  35 #include <sys/signalfd.h>
  36 #include <sys/select.h>
  37 #include <sys/poll.h>
  38 #include <sys/wait.h>
  39 #include <sys/stat.h>
  40 #include <sys/ioctl.h>
  41 #include <sys/inotify.h>
  42
  43 #include "udev.h"
  44
  45 #define UDEVD_PRIORITY                  -4
  46 #define UDEV_PRIORITY                   -2
  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 int debug_trace;
  63 static struct udev_rules *rules;
  64 static struct udev_queue_export *udev_queue_export;
  65 static struct udev_ctrl *udev_ctrl;
  66 static struct udev_monitor *monitor;
  67 static int worker_watch[2];
  68 static pid_t settle_pid;
  69 static int stop_exec_queue;
  70 static int reload_config;
  71 static int max_childs;
  72 static int childs;
  73 static struct udev_list_node event_list;
  74 static struct udev_list_node worker_list;
  75 static int udev_exit;
  76 static volatile sig_atomic_t worker_exit;
  77
  78 enum poll_fd {
  79         FD_CONTROL,
  80         FD_NETLINK,
  81         FD_INOTIFY,
  82         FD_SIGNAL,
  83         FD_WORKER,
  84 };
  85
  86 static struct pollfd pfd[] = {
  87         [FD_NETLINK] = { .events = POLLIN },
  88         [FD_WORKER] =  { .events = POLLIN },
  89         [FD_SIGNAL] =  { .events = POLLIN },
  90         [FD_INOTIFY] = { .events = POLLIN },
  91         [FD_CONTROL] = { .events = POLLIN },
  92 };
  93
  94 enum event_state {
  95         EVENT_UNDEF,
  96         EVENT_QUEUED,
  97         EVENT_RUNNING,
  98 };
  99
 100 struct event {
 101         struct udev_list_node node;
 102         struct udev *udev;
 103         struct udev_device *dev;
 104         enum event_state state;
 105         int exitcode;
 106         unsigned long long int delaying_seqnum;
 107         unsigned long long int seqnum;
 108         const char *devpath;
 109         size_t devpath_len;
 110         const char *devpath_old;
 111 };
 112
 113 static struct event *node_to_event(struct udev_list_node *node)
 114 {
 115         char *event;
 116
 117         event = (char *)node;
 118         event -= offsetof(struct event, node);
 119         return (struct event *)event;
 120 }
 121
 122 enum worker_state {
 123         WORKER_UNDEF,
 124         WORKER_RUNNING,
 125         WORKER_IDLE,
 126         WORKER_KILLED,
 127 };
 128
 129 struct worker {
 130         struct udev_list_node node;
 131         pid_t pid;
 132         struct udev_monitor *monitor;
 133         enum worker_state state;
 134         struct event *event;
 135 };
 136
 137 /* passed from worker to main process */
 138 struct worker_message {
 139         pid_t pid;
 140         int exitcode;
 141 };
 142
 143 static struct worker *node_to_worker(struct udev_list_node *node)
 144 {
 145         char *worker;
 146
 147         worker = (char *)node;
 148         worker -= offsetof(struct worker, node);
 149         return (struct worker *)worker;
 150 }
 151
 152 static void event_queue_delete(struct event *event)
 153 {
 154         udev_list_node_remove(&event->node);
 155
 156         /* mark as failed, if "add" event returns non-zero */
 157         if (event->exitcode && strcmp(udev_device_get_action(event->dev), "add") == 0)
 158                 udev_queue_export_device_failed(udev_queue_export, event->dev);
 159         else
 160                 udev_queue_export_device_finished(udev_queue_export, event->dev);
 161
 162         udev_device_unref(event->dev);
 163         free(event);
 164 }
 165
 166 static void event_sig_handler(int signum)
 167 {
 168         switch (signum) {
 169         case SIGALRM:
 170                 _exit(1);
 171                 break;
 172         case SIGTERM:
 173                 worker_exit = 1;
 174                 break;
 175         }
 176 }
 177
 178 static void worker_unref(struct worker *worker)
 179 {
 180         udev_monitor_unref(worker->monitor);
 181         free(worker);
 182 }
 183
 184 static void worker_new(struct event *event)
 185 {
 186         struct worker *worker;
 187         struct udev_monitor *worker_monitor;
 188         pid_t pid;
 189         struct sigaction act;
 190
 191         /* listen for new events */
 192         worker_monitor = udev_monitor_new_from_netlink(event->udev, NULL);
 193         if (worker_monitor == NULL)
 194                 return;
 195         /* allow the main daemon netlink address to send devices to the worker */
 196         udev_monitor_allow_unicast_sender(worker_monitor, monitor);
 197         udev_monitor_enable_receiving(worker_monitor);
 198
 199         worker = calloc(1, sizeof(struct worker));
 200         if (worker == NULL)
 201                 return;
 202
 203         pid = fork();
 204         switch (pid) {
 205         case 0: {
 206                 sigset_t mask;
 207                 struct udev_device *dev;
 208
 209                 udev_queue_export_unref(udev_queue_export);
 210                 udev_ctrl_unref(udev_ctrl);
 211                 close(pfd[FD_SIGNAL].fd);
 212                 close(worker_watch[READ_END]);
 213                 logging_close();
 214                 logging_init("udevd-work");
 215                 setpriority(PRIO_PROCESS, 0, UDEV_PRIORITY);
 216
 217                 /* set signal handlers */
 218                 memset(&act, 0x00, sizeof(act));
 219                 act.sa_handler = event_sig_handler;
 220                 sigemptyset (&act.sa_mask);
 221                 act.sa_flags = 0;
 222                 sigaction(SIGTERM, &act, NULL);
 223                 sigaction(SIGALRM, &act, NULL);
 224
 225                 /* unblock signals */
 226                 sigfillset(&mask);
 227                 sigdelset(&mask, SIGTERM);
 228                 sigdelset(&mask, SIGALRM);
 229                 sigprocmask(SIG_SETMASK, &mask, NULL);
 230
 231                 /* request TERM signal if parent exits */
 232                 prctl(PR_SET_PDEATHSIG, SIGTERM);
 233
 234                 /* initial device */
 235                 dev = event->dev;
 236
 237                 while (!worker_exit) {
 238                         struct udev_event *udev_event;
 239                         struct worker_message msg;
 240                         int err;
 241
 242                         udev_event = udev_event_new(dev);
 243                         if (udev_event == NULL)
 244                                 _exit(3);
 245
 246                         /* set timeout to prevent hanging processes */
 247                         alarm(UDEV_EVENT_TIMEOUT);
 248
 249                         /* apply rules, create node, symlinks */
 250                         err = udev_event_execute_rules(udev_event, rules);
 251
 252                         /* rules may change/disable the timeout */
 253                         if (udev_device_get_event_timeout(dev) >= 0)
 254                                 alarm(udev_device_get_event_timeout(dev));
 255
 256                         /* execute RUN= */
 257                         if (err == 0 && !udev_event->ignore_device && udev_get_run(udev_event->udev))
 258                                 udev_event_execute_run(udev_event);
 259
 260                         /* reset alarm */
 261                         alarm(0);
 262
 263                         /* apply/restore inotify watch */
 264                         if (err == 0 && udev_event->inotify_watch) {
 265                                 udev_watch_begin(udev_event->udev, dev);
 266                                 udev_device_update_db(dev);
 267                         }
 268
 269                         /* send processed event back to libudev listeners */
 270                         udev_monitor_send_device(worker_monitor, NULL, dev);
 271
 272                         info(event->udev, "seq %llu finished with %i\n", udev_device_get_seqnum(dev), err);
 273                         udev_device_unref(dev);
 274                         udev_event_unref(udev_event);
 275
 276                         /* send back the result of the event execution */
 277                         msg.exitcode = err;
 278                         msg.pid = getpid();
 279                         send(worker_watch[WRITE_END], &msg, sizeof(struct worker_message), 0);
 280
 281                         /* wait for more device messages from udevd */
 282                         do
 283                                 dev = udev_monitor_receive_device(worker_monitor);
 284                         while (!worker_exit && dev == NULL);
 285                 }
 286
 287                 udev_monitor_unref(worker_monitor);
 288                 logging_close();
 289                 exit(0);
 290         }
 291         case -1:
 292                 udev_monitor_unref(worker_monitor);
 293                 event->state = EVENT_QUEUED;
 294                 free(worker);
 295                 err(event->udev, "fork of child failed: %m\n");
 296                 break;
 297         default:
 298                 /* close monitor, but keep address around */
 299                 udev_monitor_disconnect(worker_monitor);
 300                 worker->monitor = worker_monitor;
 301                 worker->pid = pid;
 302                 worker->state = WORKER_RUNNING;
 303                 worker->event = event;
 304                 event->state = EVENT_RUNNING;
 305                 udev_list_node_append(&worker->node, &worker_list);
 306                 childs++;
 307                 break;
 308         }
 309 }
 310
 311 static void event_run(struct event *event)
 312 {
 313         struct udev_list_node *loop;
 314
 315         udev_list_node_foreach(loop, &worker_list) {
 316                 struct worker *worker = node_to_worker(loop);
 317                 ssize_t count;
 318
 319                 if (worker->state != WORKER_IDLE)
 320                         continue;
 321
 322                 worker->event = event;
 323                 worker->state = WORKER_RUNNING;
 324                 event->state = EVENT_RUNNING;
 325                 count = udev_monitor_send_device(monitor, worker->monitor, event->dev);
 326                 if (count < 0) {
 327                         err(event->udev, "worker [%u] did not accept message, kill it\n", worker->pid);
 328                         event->state = EVENT_QUEUED;
 329                         worker->state = WORKER_KILLED;
 330                         kill(worker->pid, SIGKILL);
 331                         continue;
 332                 }
 333                 return;
 334         }
 335
 336         if (childs >= max_childs) {
 337                 info(event->udev, "maximum number (%i) of childs reached\n", childs);
 338                 return;
 339         }
 340
 341         /* start new worker and pass initial device */
 342         worker_new(event);
 343 }
 344
 345 static void event_queue_insert(struct udev_device *dev)
 346 {
 347         struct event *event;
 348
 349         event = calloc(1, sizeof(struct event));
 350         if (event == NULL)
 351                 return;
 352
 353         event->udev = udev_device_get_udev(dev);
 354         event->dev = dev;
 355         event->seqnum = udev_device_get_seqnum(dev);
 356         event->devpath = udev_device_get_devpath(dev);
 357         event->devpath_len = strlen(event->devpath);
 358         event->devpath_old = udev_device_get_devpath_old(dev);
 359
 360         udev_queue_export_device_queued(udev_queue_export, dev);
 361         info(event->udev, "seq %llu queued, '%s' '%s'\n", udev_device_get_seqnum(dev),
 362              udev_device_get_action(dev), udev_device_get_subsystem(dev));
 363
 364         event->state = EVENT_QUEUED;
 365         udev_list_node_append(&event->node, &event_list);
 366
 367         /* run all events with a timeout set immediately */
 368         if (udev_device_get_timeout(dev) > 0) {
 369                 worker_new(event);
 370                 return;
 371         }
 372 }
 373
 374 static void worker_kill(int retain)
 375 {
 376         struct udev_list_node *loop;
 377         int max;
 378
 379         if (childs <= retain)
 380                 return;
 381
 382         max = childs - retain;
 383
 384         udev_list_node_foreach(loop, &worker_list) {
 385                 struct worker *worker = node_to_worker(loop);
 386
 387                 if (max-- <= 0)
 388                         break;
 389
 390                 if (worker->state == WORKER_KILLED)
 391                         continue;
 392
 393                 worker->state = WORKER_KILLED;
 394                 kill(worker->pid, SIGTERM);
 395         }
 396 }
 397
 398 static int mem_size_mb(void)
 399 {
 400         FILE *f;
 401         char buf[4096];
 402         long int memsize = -1;
 403
 404         f = fopen("/proc/meminfo", "r");
 405         if (f == NULL)
 406                 return -1;
 407
 408         while (fgets(buf, sizeof(buf), f) != NULL) {
 409                 long int value;
 410
 411                 if (sscanf(buf, "MemTotal: %ld kB", &value) == 1) {
 412                         memsize = value / 1024;
 413                         break;
 414                 }
 415         }
 416
 417         fclose(f);
 418         return memsize;
 419 }
 420
 421 /* lookup event for identical, parent, child device */
 422 static int devpath_busy(struct event *event)
 423 {
 424         struct udev_list_node *loop;
 425         size_t common;
 426
 427         /* check if queue contains events we depend on */
 428         udev_list_node_foreach(loop, &event_list) {
 429                 struct event *loop_event = node_to_event(loop);
 430
 431                 /* we already found a later event, earlier can not block us, no need to check again */
 432                 if (loop_event->seqnum < event->delaying_seqnum)
 433                         continue;
 434
 435                 /* event we checked earlier still exists, no need to check again */
 436                 if (loop_event->seqnum == event->delaying_seqnum)
 437                         return 2;
 438
 439                 /* found ourself, no later event can block us */
 440                 if (loop_event->seqnum >= event->seqnum)
 441                         break;
 442
 443                 /* check our old name */
 444                 if (event->devpath_old != NULL)
 445                         if (strcmp(loop_event->devpath, event->devpath_old) == 0) {
 446                                 event->delaying_seqnum = loop_event->seqnum;
 447                                 return 3;
 448                         }
 449
 450                 /* compare devpath */
 451                 common = MIN(loop_event->devpath_len, event->devpath_len);
 452
 453                 /* one devpath is contained in the other? */
 454                 if (memcmp(loop_event->devpath, event->devpath, common) != 0)
 455                         continue;
 456
 457                 /* identical device event found */
 458                 if (loop_event->devpath_len == event->devpath_len) {
 459                         event->delaying_seqnum = loop_event->seqnum;
 460                         return 4;
 461                 }
 462
 463                 /* parent device event found */
 464                 if (event->devpath[common] == '/') {
 465                         event->delaying_seqnum = loop_event->seqnum;
 466                         return 5;
 467                 }
 468
 469                 /* child device event found */
 470                 if (loop_event->devpath[common] == '/') {
 471                         event->delaying_seqnum = loop_event->seqnum;
 472                         return 6;
 473                 }
 474
 475                 /* no matching device */
 476                 continue;
 477         }
 478
 479         return 0;
 480 }
 481
 482 static void events_start(struct udev *udev)
 483 {
 484         struct udev_list_node *loop;
 485
 486         udev_list_node_foreach(loop, &event_list) {
 487                 struct event *event = node_to_event(loop);
 488
 489                 if (event->state != EVENT_QUEUED)
 490                         continue;
 491
 492                 /* do not start event if parent or child event is still running */
 493                 if (devpath_busy(event) != 0) {
 494                         dbg(udev, "delay seq %llu (%s)\n", event->seqnum, event->devpath);
 495                         continue;
 496                 }
 497
 498                 event_run(event);
 499         }
 500 }
 501
 502 static void worker_returned(void)
 503 {
 504         while (1) {
 505                 struct worker_message msg;
 506                 ssize_t size;
 507                 struct udev_list_node *loop;
 508
 509                 size = recv(pfd[FD_WORKER].fd, &msg, sizeof(struct worker_message), MSG_DONTWAIT);
 510                 if (size != sizeof(struct worker_message))
 511                         break;
 512
 513                 /* lookup worker who sent the signal */
 514                 udev_list_node_foreach(loop, &worker_list) {
 515                         struct worker *worker = node_to_worker(loop);
 516
 517                         if (worker->pid != msg.pid)
 518                                 continue;
 519
 520                         /* worker returned */
 521                         worker->event->exitcode = msg.exitcode;
 522                         event_queue_delete(worker->event);
 523                         worker->event = NULL;
 524                         worker->state = WORKER_IDLE;
 525                         break;
 526                 }
 527         }
 528 }
 529
 530 /* receive the udevd message from userspace */
 531 static void handle_ctrl_msg(struct udev_ctrl *uctrl)
 532 {
 533         struct udev *udev = udev_ctrl_get_udev(uctrl);
 534         struct udev_ctrl_msg *ctrl_msg;
 535         const char *str;
 536         int i;
 537
 538         ctrl_msg = udev_ctrl_receive_msg(uctrl);
 539         if (ctrl_msg == NULL)
 540                 return;
 541
 542         i = udev_ctrl_get_set_log_level(ctrl_msg);
 543         if (i >= 0) {
 544                 info(udev, "udevd message (SET_LOG_PRIORITY) received, log_priority=%i\n", i);
 545                 udev_set_log_priority(udev, i);
 546                 worker_kill(0);
 547         }
 548
 549         if (udev_ctrl_get_stop_exec_queue(ctrl_msg) > 0) {
 550                 info(udev, "udevd message (STOP_EXEC_QUEUE) received\n");
 551                 stop_exec_queue = 1;
 552         }
 553
 554         if (udev_ctrl_get_start_exec_queue(ctrl_msg) > 0) {
 555                 info(udev, "udevd message (START_EXEC_QUEUE) received\n");
 556                 stop_exec_queue = 0;
 557         }
 558
 559         if (udev_ctrl_get_reload_rules(ctrl_msg) > 0) {
 560                 info(udev, "udevd message (RELOAD_RULES) received\n");
 561                 reload_config = 1;
 562         }
 563
 564         str = udev_ctrl_get_set_env(ctrl_msg);
 565         if (str != NULL) {
 566                 char *key;
 567
 568                 key = strdup(str);
 569                 if (key != NULL) {
 570                         char *val;
 571
 572                         val = strchr(key, '=');
 573                         if (val != NULL) {
 574                                 val[0] = '\0';
 575                                 val = &val[1];
 576                                 if (val[0] == '\0') {
 577                                         info(udev, "udevd message (ENV) received, unset '%s'\n", key);
 578                                         udev_add_property(udev, key, NULL);
 579                                 } else {
 580                                         info(udev, "udevd message (ENV) received, set '%s=%s'\n", key, val);
 581                                         udev_add_property(udev, key, val);
 582                                 }
 583                         } else {
 584                                 err(udev, "wrong key format '%s'\n", key);
 585                         }
 586                         free(key);
 587                 }
 588                 worker_kill(0);
 589         }
 590
 591         i = udev_ctrl_get_set_max_childs(ctrl_msg);
 592         if (i >= 0) {
 593                 info(udev, "udevd message (SET_MAX_CHILDS) received, max_childs=%i\n", i);
 594                 max_childs = i;
 595         }
 596
 597         settle_pid = udev_ctrl_get_settle(ctrl_msg);
 598         if (settle_pid > 0) {
 599                 info(udev, "udevd message (SETTLE) received\n");
 600                 kill(settle_pid, SIGUSR1);
 601                 settle_pid = 0;
 602         }
 603         udev_ctrl_msg_unref(ctrl_msg);
 604 }
 605
 606 /* read inotify messages */
 607 static int handle_inotify(struct udev *udev)
 608 {
 609         ssize_t nbytes, pos;
 610         char *buf;
 611         struct inotify_event *ev;
 612
 613         if ((ioctl(pfd[FD_INOTIFY].fd, FIONREAD, &nbytes) < 0) || (nbytes <= 0))
 614                 return 0;
 615
 616         buf = malloc(nbytes);
 617         if (buf == NULL) {
 618                 err(udev, "error getting buffer for inotify, disable watching\n");
 619                 return -1;
 620         }
 621
 622         nbytes = read(pfd[FD_INOTIFY].fd, buf, nbytes);
 623
 624         for (pos = 0; pos < nbytes; pos += sizeof(struct inotify_event) + ev->len) {
 625                 struct udev_device *dev;
 626
 627                 ev = (struct inotify_event *)(buf + pos);
 628                 if (ev->len) {
 629                         dbg(udev, "inotify event: %x for %s\n", ev->mask, ev->name);
 630                         reload_config = 1;
 631                         continue;
 632                 }
 633
 634                 dev = udev_watch_lookup(udev, ev->wd);
 635                 if (dev != NULL) {
 636                         dbg(udev, "inotify event: %x for %s\n", ev->mask, udev_device_get_devnode(dev));
 637                         if (ev->mask & IN_CLOSE_WRITE) {
 638                                 char filename[UTIL_PATH_SIZE];
 639                                 int fd;
 640
 641                                 info(udev, "device %s closed, synthesising 'change'\n", udev_device_get_devnode(dev));
 642                                 util_strscpyl(filename, sizeof(filename), udev_device_get_syspath(dev), "/uevent", NULL);
 643                                 fd = open(filename, O_WRONLY);
 644                                 if (fd < 0 || write(fd, "change", 6) < 0)
 645                                         info(udev, "error writing uevent: %m\n");
 646                                 close(fd);
 647                         }
 648                         if (ev->mask & IN_IGNORED)
 649                                 udev_watch_end(udev, dev);
 650
 651                         udev_device_unref(dev);
 652                 }
 653
 654         }
 655
 656         free(buf);
 657         return 0;
 658 }
 659
 660 static void handle_signal(int signo)
 661 {
 662         switch (signo) {
 663         case SIGINT:
 664         case SIGTERM:
 665                 udev_exit = 1;
 666                 break;
 667         case SIGCHLD:
 668                 while (1) {
 669                         pid_t pid;
 670                         struct udev_list_node *loop, *tmp;
 671
 672                         pid = waitpid(-1, NULL, WNOHANG);
 673                         if (pid <= 0)
 674                                 break;
 675
 676                         udev_list_node_foreach_safe(loop, tmp, &worker_list) {
 677                                 struct worker *worker = node_to_worker(loop);
 678
 679                                 if (worker->pid != pid)
 680                                         continue;
 681
 682                                 /* fail event, if worker died unexpectedly */
 683                                 if (worker->event != NULL) {
 684                                         worker->event->exitcode = 127;
 685                                         event_queue_delete(worker->event);
 686                                 }
 687
 688                                 udev_list_node_remove(&worker->node);
 689                                 worker_unref(worker);
 690                                 childs--;
 691                                 break;
 692                         }
 693                 }
 694                 break;
 695         case SIGHUP:
 696                 reload_config = 1;
 697                 break;
 698         }
 699 }
 700
 701 static void startup_log(struct udev *udev)
 702 {
 703         FILE *f;
 704         char path[UTIL_PATH_SIZE];
 705         struct stat statbuf;
 706
 707         f = fopen("/dev/kmsg", "w");
 708         if (f != NULL)
 709                 fprintf(f, "<6>udev: starting version " VERSION "\n");
 710
 711         util_strscpyl(path, sizeof(path), udev_get_sys_path(udev), "/class/mem/null", NULL);
 712         if (lstat(path, &statbuf) == 0 && S_ISDIR(statbuf.st_mode)) {
 713                 const char *depr_str =
 714                         "udev: missing sysfs features; please update the kernel "
 715                         "or disable the kernel's CONFIG_SYSFS_DEPRECATED option; "
 716                         "udev may fail to work correctly";
 717
 718                 if (f != NULL)
 719                         fprintf(f, "<3>%s\n", depr_str);
 720                 err(udev, "%s\n", depr_str);
 721                 sleep(3);
 722         }
 723
 724         if (f != NULL)
 725                 fclose(f);
 726 }
 727
 728 int main(int argc, char *argv[])
 729 {
 730         struct udev *udev;
 731         int fd;
 732         sigset_t mask;
 733         const char *value;
 734         int daemonize = 0;
 735         int resolve_names = 1;
 736         static const struct option options[] = {
 737                 { "daemon", no_argument, NULL, 'd' },
 738                 { "debug-trace", no_argument, NULL, 't' },
 739                 { "debug", no_argument, NULL, 'D' },
 740                 { "help", no_argument, NULL, 'h' },
 741                 { "version", no_argument, NULL, 'V' },
 742                 { "resolve-names", required_argument, NULL, 'N' },
 743                 {}
 744         };
 745         int rc = 1;
 746
 747         udev = udev_new();
 748         if (udev == NULL)
 749                 goto exit;
 750
 751         logging_init("udevd");
 752         udev_set_log_fn(udev, log_fn);
 753         info(udev, "version %s\n", VERSION);
 754         udev_selinux_init(udev);
 755
 756         while (1) {
 757                 int option;
 758
 759                 option = getopt_long(argc, argv, "dDthV", options, NULL);
 760                 if (option == -1)
 761                         break;
 762
 763                 switch (option) {
 764                 case 'd':
 765                         daemonize = 1;
 766                         break;
 767                 case 't':
 768                         debug_trace = 1;
 769                         break;
 770                 case 'D':
 771                         debug = 1;
 772                         if (udev_get_log_priority(udev) < LOG_INFO)
 773                                 udev_set_log_priority(udev, LOG_INFO);
 774                         break;
 775                 case 'N':
 776                         if (strcmp (optarg, "early") == 0) {
 777                                 resolve_names = 1;
 778                         } else if (strcmp (optarg, "late") == 0) {
 779                                 resolve_names = 0;
 780                         } else if (strcmp (optarg, "never") == 0) {
 781                                 resolve_names = -1;
 782                         } else {
 783                                 fprintf(stderr, "resolve-names must be early, late or never\n");
 784                                 err(udev, "resolve-names must be early, late or never\n");
 785                                 goto exit;
 786                         }
 787                         break;
 788                 case 'h':
 789                         printf("Usage: udevd [--help] [--daemon] [--debug-trace] [--debug] "
 790                                "[--resolve-names=early|late|never] [--version]\n");
 791                         goto exit;
 792                 case 'V':
 793                         printf("%s\n", VERSION);
 794                         goto exit;
 795                 default:
 796                         goto exit;
 797                 }
 798         }
 799
 800         if (getuid() != 0) {
 801                 fprintf(stderr, "root privileges required\n");
 802                 err(udev, "root privileges required\n");
 803                 goto exit;
 804         }
 805
 806         /* make sure std{in,out,err} fd's are in a sane state */
 807         fd = open("/dev/null", O_RDWR);
 808         if (fd < 0) {
 809                 fprintf(stderr, "cannot open /dev/null\n");
 810                 err(udev, "cannot open /dev/null\n");
 811         }
 812         if (write(STDOUT_FILENO, 0, 0) < 0)
 813                 dup2(fd, STDOUT_FILENO);
 814         if (write(STDERR_FILENO, 0, 0) < 0)
 815                 dup2(fd, STDERR_FILENO);
 816
 817         /* init control socket, bind() ensures, that only one udevd instance is running */
 818         udev_ctrl = udev_ctrl_new_from_socket(udev, UDEV_CTRL_SOCK_PATH);
 819         if (udev_ctrl == NULL) {
 820                 fprintf(stderr, "error initializing control socket");
 821                 err(udev, "error initializing udevd socket");
 822                 rc = 1;
 823                 goto exit;
 824         }
 825         if (udev_ctrl_enable_receiving(udev_ctrl) < 0) {
 826                 fprintf(stderr, "error binding control socket, seems udevd is already running\n");
 827                 err(udev, "error binding control socket, seems udevd is already running\n");
 828                 rc = 1;
 829                 goto exit;
 830         }
 831         pfd[FD_CONTROL].fd = udev_ctrl_get_fd(udev_ctrl);
 832
 833         monitor = udev_monitor_new_from_netlink(udev, "kernel");
 834         if (monitor == NULL || udev_monitor_enable_receiving(monitor) < 0) {
 835                 fprintf(stderr, "error initializing netlink socket\n");
 836                 err(udev, "error initializing netlink socket\n");
 837                 rc = 3;
 838                 goto exit;
 839         }
 840         udev_monitor_set_receive_buffer_size(monitor, 128*1024*1024);
 841         pfd[FD_NETLINK].fd = udev_monitor_get_fd(monitor);
 842
 843         pfd[FD_INOTIFY].fd = udev_watch_init(udev);
 844         if (pfd[FD_INOTIFY].fd < 0) {
 845                 fprintf(stderr, "error initializing inotify\n");
 846                 err(udev, "error initializing inotify\n");
 847                 rc = 4;
 848                 goto exit;
 849         }
 850
 851         if (udev_get_rules_path(udev) != NULL) {
 852                 inotify_add_watch(pfd[FD_INOTIFY].fd, udev_get_rules_path(udev),
 853                                   IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
 854         } else {
 855                 char filename[UTIL_PATH_SIZE];
 856
 857                 inotify_add_watch(pfd[FD_INOTIFY].fd, UDEV_PREFIX "/lib/udev/rules.d",
 858                                   IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
 859                 inotify_add_watch(pfd[FD_INOTIFY].fd, SYSCONFDIR "/udev/rules.d",
 860                                   IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
 861
 862                 /* watch dynamic rules directory */
 863                 util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev), "/.udev/rules.d", NULL);
 864                 inotify_add_watch(pfd[FD_INOTIFY].fd, filename,
 865                                   IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
 866         }
 867         udev_watch_restore(udev);
 868
 869         /* block and listen to all signals on signalfd */
 870         sigfillset(&mask);
 871         sigprocmask(SIG_SETMASK, &mask, NULL);
 872         pfd[FD_SIGNAL].fd = signalfd(-1, &mask, 0);
 873         if (pfd[FD_SIGNAL].fd < 0) {
 874                 fprintf(stderr, "error getting signalfd\n");
 875                 err(udev, "error getting signalfd\n");
 876                 rc = 5;
 877                 goto exit;
 878         }
 879
 880         /* unnamed socket from workers to the main daemon */
 881         if (socketpair(AF_LOCAL, SOCK_DGRAM, 0, worker_watch) < 0) {
 882                 fprintf(stderr, "error getting socketpair\n");
 883                 err(udev, "error getting socketpair\n");
 884                 rc = 6;
 885                 goto exit;
 886         }
 887         pfd[FD_WORKER].fd = worker_watch[READ_END];
 888
 889         rules = udev_rules_new(udev, resolve_names);
 890         if (rules == NULL) {
 891                 err(udev, "error reading rules\n");
 892                 goto exit;
 893         }
 894
 895         udev_queue_export = udev_queue_export_new(udev);
 896         if (udev_queue_export == NULL) {
 897                 err(udev, "error creating queue file\n");
 898                 goto exit;
 899         }
 900
 901         if (daemonize) {
 902                 pid_t pid;
 903
 904                 pid = fork();
 905                 switch (pid) {
 906                 case 0:
 907                         break;
 908                 case -1:
 909                         err(udev, "fork of daemon failed: %m\n");
 910                         rc = 4;
 911                         goto exit;
 912                 default:
 913                         rc = 0;
 914                         goto exit;
 915                 }
 916         }
 917
 918         startup_log(udev);
 919
 920         /* redirect std{out,err} */
 921         if (!debug && !debug_trace) {
 922                 dup2(fd, STDIN_FILENO);
 923                 dup2(fd, STDOUT_FILENO);
 924                 dup2(fd, STDERR_FILENO);
 925         }
 926         if (fd > STDERR_FILENO)
 927                 close(fd);
 928
 929         /* set scheduling priority for the daemon */
 930         setpriority(PRIO_PROCESS, 0, UDEVD_PRIORITY);
 931
 932         chdir("/");
 933         umask(022);
 934         setsid();
 935
 936         /* OOM_DISABLE == -17 */
 937         fd = open("/proc/self/oom_adj", O_RDWR);
 938         if (fd < 0)
 939                 err(udev, "error disabling OOM: %m\n");
 940         else {
 941                 write(fd, "-17", 3);
 942                 close(fd);
 943         }
 944
 945         /* in trace mode run one event after the other */
 946         if (debug_trace) {
 947                 max_childs = 1;
 948         } else {
 949                 int memsize = mem_size_mb();
 950
 951                 if (memsize > 0)
 952                         max_childs = 128 + (memsize / 8);
 953                 else
 954                         max_childs = 128;
 955         }
 956
 957         /* possibly overwrite maximum limit of executed events */
 958         value = getenv("UDEVD_MAX_CHILDS");
 959         if (value)
 960                 max_childs = strtoul(value, NULL, 10);
 961         info(udev, "initialize max_childs to %u\n", max_childs);
 962
 963         udev_list_init(&event_list);
 964         udev_list_init(&worker_list);
 965
 966         while (!udev_exit) {
 967                 int fdcount;
 968                 int timeout;
 969
 970                 /* set timeout to kill idle workers */
 971                 if (udev_list_is_empty(&event_list) && childs > 2)
 972                         timeout = 3 * 1000;
 973                 else
 974                         timeout = -1;
 975                 /* wait for events */
 976                 fdcount = poll(pfd, ARRAY_SIZE(pfd), timeout);
 977                 if (fdcount < 0)
 978                         continue;
 979
 980                 /* timeout - kill idle workers */
 981                 if (fdcount == 0)
 982                         worker_kill(2);
 983
 984                 /* event has finished */
 985                 if (pfd[FD_WORKER].revents & POLLIN)
 986                         worker_returned();
 987
 988                 /* get kernel uevent */
 989                 if (pfd[FD_NETLINK].revents & POLLIN) {
 990                         struct udev_device *dev;
 991
 992                         dev = udev_monitor_receive_device(monitor);
 993                         if (dev != NULL)
 994                                 event_queue_insert(dev);
 995                         else
 996                                 udev_device_unref(dev);
 997                 }
 998
 999                 /* start new events */
1000                 if (!udev_list_is_empty(&event_list) && !stop_exec_queue)
1001                         events_start(udev);
1002
1003                 /* get signal */
1004                 if (pfd[FD_SIGNAL].revents & POLLIN) {
1005                         struct signalfd_siginfo fdsi;
1006                         ssize_t size;
1007
1008                         size = read(pfd[FD_SIGNAL].fd, &fdsi, sizeof(struct signalfd_siginfo));
1009                         if (size == sizeof(struct signalfd_siginfo))
1010                                 handle_signal(fdsi.ssi_signo);
1011                 }
1012
1013                 /* device node and rules directory inotify watch */
1014                 if (pfd[FD_INOTIFY].revents & POLLIN)
1015                         handle_inotify(udev);
1016
1017                 /*
1018                  * get control message
1019                  *
1020                  * This needs to be after the inotify handling, to make sure,
1021                  * that the settle signal is send back after the possibly generated
1022                  * "change" events by the inotify device node watch.
1023                  */
1024                 if (pfd[FD_CONTROL].revents & POLLIN)
1025                         handle_ctrl_msg(udev_ctrl);
1026
1027                 /* rules changed, set by inotify or a HUP signal */
1028                 if (reload_config) {
1029                         struct udev_rules *rules_new;
1030
1031                         worker_kill(0);
1032                         rules_new = udev_rules_new(udev, resolve_names);
1033                         if (rules_new != NULL) {
1034                                 udev_rules_unref(rules);
1035                                 rules = rules_new;
1036                         }
1037                         reload_config = 0;
1038                 }
1039         }
1040
1041         udev_queue_export_cleanup(udev_queue_export);
1042         rc = 0;
1043 exit:
1044         udev_queue_export_unref(udev_queue_export);
1045         udev_rules_unref(rules);
1046         udev_ctrl_unref(udev_ctrl);
1047         if (pfd[FD_SIGNAL].fd >= 0)
1048                 close(pfd[FD_SIGNAL].fd);
1049         if (worker_watch[READ_END] >= 0)
1050                 close(worker_watch[READ_END]);
1051         if (worker_watch[WRITE_END] >= 0)
1052                 close(worker_watch[WRITE_END]);
1053         udev_monitor_unref(monitor);
1054         udev_selinux_exit(udev);
1055         udev_unref(udev);
1056         logging_close();
1057         return rc;
1058 }