udev/udevd.c

   1 /*
   2  * Copyright (C) 2004-2011 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 <stdbool.h>
  28 #include <string.h>
  29 #include <ctype.h>
  30 #include <fcntl.h>
  31 #include <time.h>
  32 #include <getopt.h>
  33 #include <dirent.h>
  34 #include <sys/time.h>
  35 #include <sys/prctl.h>
  36 #include <sys/socket.h>
  37 #include <sys/un.h>
  38 #include <sys/signalfd.h>
  39 #include <sys/epoll.h>
  40 #include <sys/poll.h>
  41 #include <sys/wait.h>
  42 #include <sys/stat.h>
  43 #include <sys/ioctl.h>
  44 #include <sys/inotify.h>
  45 #include <sys/utsname.h>
  46
  47 #include "udev.h"
  48 #include "sd-daemon.h"
  49
  50 static bool debug;
  51
  52 void udev_main_log(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                 char buf[1024];
  58                 struct timespec ts;
  59
  60                 vsnprintf(buf, sizeof(buf), format, args);
  61                 clock_gettime(CLOCK_MONOTONIC, &ts);
  62                 fprintf(stderr, "[%llu.%06u] [%u] %s: %s",
  63                         (unsigned long long) ts.tv_sec, (unsigned int) ts.tv_nsec/1000,
  64                         (int) getpid(), fn, buf);
  65         } else {
  66                 vsyslog(priority, format, args);
  67         }
  68 }
  69
  70 static struct udev_rules *rules;
  71 static struct udev_queue_export *udev_queue_export;
  72 static struct udev_ctrl *udev_ctrl;
  73 static struct udev_monitor *monitor;
  74 static int worker_watch[2] = { -1, -1 };
  75 static int fd_signal = -1;
  76 static int fd_ep = -1;
  77 static int fd_inotify = -1;
  78 static bool stop_exec_queue;
  79 static bool reload;
  80 static int children;
  81 static int children_max;
  82 static int exec_delay;
  83 static sigset_t sigmask_orig;
  84 static UDEV_LIST(event_list);
  85 static UDEV_LIST(worker_list);
  86 static bool udev_exit;
  87
  88 enum event_state {
  89         EVENT_UNDEF,
  90         EVENT_QUEUED,
  91         EVENT_RUNNING,
  92 };
  93
  94 struct event {
  95         struct udev_list_node node;
  96         struct udev *udev;
  97         struct udev_device *dev;
  98         enum event_state state;
  99         int exitcode;
 100         unsigned long long int delaying_seqnum;
 101         unsigned long long int seqnum;
 102         const char *devpath;
 103         size_t devpath_len;
 104         const char *devpath_old;
 105         dev_t devnum;
 106         bool is_block;
 107         int ifindex;
 108 };
 109
 110 static struct event *node_to_event(struct udev_list_node *node)
 111 {
 112         char *event;
 113
 114         event = (char *)node;
 115         event -= offsetof(struct event, node);
 116         return (struct event *)event;
 117 }
 118
 119 static void event_queue_cleanup(struct udev *udev, enum event_state type);
 120
 121 enum worker_state {
 122         WORKER_UNDEF,
 123         WORKER_RUNNING,
 124         WORKER_IDLE,
 125         WORKER_KILLED,
 126 };
 127
 128 struct worker {
 129         struct udev_list_node node;
 130         struct udev *udev;
 131         int refcount;
 132         pid_t pid;
 133         struct udev_monitor *monitor;
 134         enum worker_state state;
 135         struct event *event;
 136 };
 137
 138 /* passed from worker to main process */
 139 struct worker_message {
 140         pid_t pid;
 141         int exitcode;
 142 };
 143
 144 static struct worker *node_to_worker(struct udev_list_node *node)
 145 {
 146         char *worker;
 147
 148         worker = (char *)node;
 149         worker -= offsetof(struct worker, node);
 150         return (struct worker *)worker;
 151 }
 152
 153 static void event_queue_delete(struct event *event, bool export)
 154 {
 155         udev_list_node_remove(&event->node);
 156
 157         if (export) {
 158                 udev_queue_export_device_finished(udev_queue_export, event->dev);
 159                 info(event->udev, "seq %llu done with %i\n", udev_device_get_seqnum(event->dev), event->exitcode);
 160         }
 161         udev_device_unref(event->dev);
 162         free(event);
 163 }
 164
 165 static struct worker *worker_ref(struct worker *worker)
 166 {
 167         worker->refcount++;
 168         return worker;
 169 }
 170
 171 static void worker_cleanup(struct worker *worker)
 172 {
 173         udev_list_node_remove(&worker->node);
 174         udev_monitor_unref(worker->monitor);
 175         children--;
 176         free(worker);
 177 }
 178
 179 static void worker_unref(struct worker *worker)
 180 {
 181         worker->refcount--;
 182         if (worker->refcount > 0)
 183                 return;
 184         info(worker->udev, "worker [%u] cleaned up\n", worker->pid);
 185         worker_cleanup(worker);
 186 }
 187
 188 static void worker_list_cleanup(struct udev *udev)
 189 {
 190         struct udev_list_node *loop, *tmp;
 191
 192         udev_list_node_foreach_safe(loop, tmp, &worker_list) {
 193                 struct worker *worker = node_to_worker(loop);
 194
 195                 worker_cleanup(worker);
 196         }
 197 }
 198
 199 static void worker_new(struct event *event)
 200 {
 201         struct udev *udev = event->udev;
 202         struct worker *worker;
 203         struct udev_monitor *worker_monitor;
 204         pid_t pid;
 205
 206         /* listen for new events */
 207         worker_monitor = udev_monitor_new_from_netlink(udev, NULL);
 208         if (worker_monitor == NULL)
 209                 return;
 210         /* allow the main daemon netlink address to send devices to the worker */
 211         udev_monitor_allow_unicast_sender(worker_monitor, monitor);
 212         udev_monitor_enable_receiving(worker_monitor);
 213
 214         worker = calloc(1, sizeof(struct worker));
 215         if (worker == NULL) {
 216                 udev_monitor_unref(worker_monitor);
 217                 return;
 218         }
 219         /* worker + event reference */
 220         worker->refcount = 2;
 221         worker->udev = udev;
 222
 223         pid = fork();
 224         switch (pid) {
 225         case 0: {
 226                 struct udev_device *dev = NULL;
 227                 int fd_monitor;
 228                 struct epoll_event ep_signal, ep_monitor;
 229                 sigset_t mask;
 230                 int rc = EXIT_SUCCESS;
 231
 232                 /* move initial device from queue */
 233                 dev = event->dev;
 234                 event->dev = NULL;
 235
 236                 free(worker);
 237                 worker_list_cleanup(udev);
 238                 event_queue_cleanup(udev, EVENT_UNDEF);
 239                 udev_queue_export_unref(udev_queue_export);
 240                 udev_monitor_unref(monitor);
 241                 udev_ctrl_unref(udev_ctrl);
 242                 close(fd_signal);
 243                 close(fd_ep);
 244                 close(worker_watch[READ_END]);
 245
 246                 sigfillset(&mask);
 247                 fd_signal = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC);
 248                 if (fd_signal < 0) {
 249                         err(udev, "error creating signalfd %m\n");
 250                         rc = 2;
 251                         goto out;
 252                 }
 253
 254                 fd_ep = epoll_create1(EPOLL_CLOEXEC);
 255                 if (fd_ep < 0) {
 256                         err(udev, "error creating epoll fd: %m\n");
 257                         rc = 3;
 258                         goto out;
 259                 }
 260
 261                 memset(&ep_signal, 0, sizeof(struct epoll_event));
 262                 ep_signal.events = EPOLLIN;
 263                 ep_signal.data.fd = fd_signal;
 264
 265                 fd_monitor = udev_monitor_get_fd(worker_monitor);
 266                 memset(&ep_monitor, 0, sizeof(struct epoll_event));
 267                 ep_monitor.events = EPOLLIN;
 268                 ep_monitor.data.fd = fd_monitor;
 269
 270                 if (epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_signal, &ep_signal) < 0 ||
 271                     epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_monitor, &ep_monitor) < 0) {
 272                         err(udev, "fail to add fds to epoll: %m\n");
 273                         rc = 4;
 274                         goto out;
 275                 }
 276
 277                 /* request TERM signal if parent exits */
 278                 prctl(PR_SET_PDEATHSIG, SIGTERM);
 279
 280                 for (;;) {
 281                         struct udev_event *udev_event;
 282                         struct worker_message msg;
 283                         int err;
 284
 285                         info(udev, "seq %llu running\n", udev_device_get_seqnum(dev));
 286                         udev_event = udev_event_new(dev);
 287                         if (udev_event == NULL) {
 288                                 rc = 5;
 289                                 goto out;
 290                         }
 291
 292                         /* needed for SIGCHLD/SIGTERM in spawn() */
 293                         udev_event->fd_signal = fd_signal;
 294
 295                         if (exec_delay > 0)
 296                                 udev_event->exec_delay = exec_delay;
 297
 298                         /* apply rules, create node, symlinks */
 299                         err = udev_event_execute_rules(udev_event, rules, &sigmask_orig);
 300
 301                         if (err == 0)
 302                                 udev_event_execute_run(udev_event, &sigmask_orig);
 303
 304                         /* apply/restore inotify watch */
 305                         if (err == 0 && udev_event->inotify_watch) {
 306                                 udev_watch_begin(udev, dev);
 307                                 udev_device_update_db(dev);
 308                         }
 309
 310                         /* send processed event back to libudev listeners */
 311                         udev_monitor_send_device(worker_monitor, NULL, dev);
 312
 313                         /* send udevd the result of the event execution */
 314                         memset(&msg, 0, sizeof(struct worker_message));
 315                         if (err != 0)
 316                                 msg.exitcode = err;
 317                         msg.pid = getpid();
 318                         send(worker_watch[WRITE_END], &msg, sizeof(struct worker_message), 0);
 319
 320                         info(udev, "seq %llu processed with %i\n", udev_device_get_seqnum(dev), err);
 321
 322                         udev_device_unref(dev);
 323                         dev = NULL;
 324
 325                         if (udev_event->sigterm) {
 326                                 udev_event_unref(udev_event);
 327                                 goto out;
 328                         }
 329
 330                         udev_event_unref(udev_event);
 331
 332                         /* wait for more device messages from main udevd, or term signal */
 333                         while (dev == NULL) {
 334                                 struct epoll_event ev[4];
 335                                 int fdcount;
 336                                 int i;
 337
 338                                 fdcount = epoll_wait(fd_ep, ev, ARRAY_SIZE(ev), -1);
 339                                 if (fdcount < 0) {
 340                                         if (errno == EINTR)
 341                                                 continue;
 342                                         err = -errno;
 343                                         err(udev, "failed to poll: %m\n");
 344                                         goto out;
 345                                 }
 346
 347                                 for (i = 0; i < fdcount; i++) {
 348                                         if (ev[i].data.fd == fd_monitor && ev[i].events & EPOLLIN) {
 349                                                 dev = udev_monitor_receive_device(worker_monitor);
 350                                                 break;
 351                                         } else if (ev[i].data.fd == fd_signal && ev[i].events & EPOLLIN) {
 352                                                 struct signalfd_siginfo fdsi;
 353                                                 ssize_t size;
 354
 355                                                 size = read(fd_signal, &fdsi, sizeof(struct signalfd_siginfo));
 356                                                 if (size != sizeof(struct signalfd_siginfo))
 357                                                         continue;
 358                                                 switch (fdsi.ssi_signo) {
 359                                                 case SIGTERM:
 360                                                         goto out;
 361                                                 }
 362                                         }
 363                                 }
 364                         }
 365                 }
 366 out:
 367                 udev_device_unref(dev);
 368                 if (fd_signal >= 0)
 369                         close(fd_signal);
 370                 if (fd_ep >= 0)
 371                         close(fd_ep);
 372                 close(fd_inotify);
 373                 close(worker_watch[WRITE_END]);
 374                 udev_rules_unref(rules);
 375                 udev_monitor_unref(worker_monitor);
 376                 udev_unref(udev);
 377                 udev_log_close();
 378                 exit(rc);
 379         }
 380         case -1:
 381                 udev_monitor_unref(worker_monitor);
 382                 event->state = EVENT_QUEUED;
 383                 free(worker);
 384                 err(udev, "fork of child failed: %m\n");
 385                 break;
 386         default:
 387                 /* close monitor, but keep address around */
 388                 udev_monitor_disconnect(worker_monitor);
 389                 worker->monitor = worker_monitor;
 390                 worker->pid = pid;
 391                 worker->state = WORKER_RUNNING;
 392                 worker->event = event;
 393                 event->state = EVENT_RUNNING;
 394                 udev_list_node_append(&worker->node, &worker_list);
 395                 children++;
 396                 info(udev, "seq %llu forked new worker [%u]\n", udev_device_get_seqnum(event->dev), pid);
 397                 break;
 398         }
 399 }
 400
 401 static void event_run(struct event *event, bool force)
 402 {
 403         struct udev_list_node *loop;
 404
 405         udev_list_node_foreach(loop, &worker_list) {
 406                 struct worker *worker = node_to_worker(loop);
 407                 ssize_t count;
 408
 409                 if (worker->state != WORKER_IDLE)
 410                         continue;
 411
 412                 count = udev_monitor_send_device(monitor, worker->monitor, event->dev);
 413                 if (count < 0) {
 414                         err(event->udev, "worker [%u] did not accept message %zi (%m), kill it\n", worker->pid, count);
 415                         kill(worker->pid, SIGKILL);
 416                         worker->state = WORKER_KILLED;
 417                         continue;
 418                 }
 419                 worker_ref(worker);
 420                 worker->event = event;
 421                 worker->state = WORKER_RUNNING;
 422                 event->state = EVENT_RUNNING;
 423                 return;
 424         }
 425
 426         if (!force && children >= children_max) {
 427                 if (children_max > 1)
 428                         info(event->udev, "maximum number (%i) of children reached\n", children);
 429                 return;
 430         }
 431
 432         /* start new worker and pass initial device */
 433         worker_new(event);
 434 }
 435
 436 static int event_queue_insert(struct udev_device *dev)
 437 {
 438         struct event *event;
 439
 440         event = calloc(1, sizeof(struct event));
 441         if (event == NULL)
 442                 return -1;
 443
 444         event->udev = udev_device_get_udev(dev);
 445         event->dev = dev;
 446         event->seqnum = udev_device_get_seqnum(dev);
 447         event->devpath = udev_device_get_devpath(dev);
 448         event->devpath_len = strlen(event->devpath);
 449         event->devpath_old = udev_device_get_devpath_old(dev);
 450         event->devnum = udev_device_get_devnum(dev);
 451         event->is_block = (strcmp("block", udev_device_get_subsystem(dev)) == 0);
 452         event->ifindex = udev_device_get_ifindex(dev);
 453
 454         udev_queue_export_device_queued(udev_queue_export, dev);
 455         info(event->udev, "seq %llu queued, '%s' '%s'\n", udev_device_get_seqnum(dev),
 456              udev_device_get_action(dev), udev_device_get_subsystem(dev));
 457
 458         event->state = EVENT_QUEUED;
 459         udev_list_node_append(&event->node, &event_list);
 460         return 0;
 461 }
 462
 463 static void worker_kill(struct udev *udev, int retain)
 464 {
 465         struct udev_list_node *loop;
 466         int max;
 467
 468         if (children <= retain)
 469                 return;
 470
 471         max = children - retain;
 472
 473         udev_list_node_foreach(loop, &worker_list) {
 474                 struct worker *worker = node_to_worker(loop);
 475
 476                 if (max-- <= 0)
 477                         break;
 478
 479                 if (worker->state == WORKER_KILLED)
 480                         continue;
 481
 482                 worker->state = WORKER_KILLED;
 483                 kill(worker->pid, SIGTERM);
 484         }
 485 }
 486
 487 /* lookup event for identical, parent, child device */
 488 static bool is_devpath_busy(struct event *event)
 489 {
 490         struct udev_list_node *loop;
 491         size_t common;
 492
 493         /* check if queue contains events we depend on */
 494         udev_list_node_foreach(loop, &event_list) {
 495                 struct event *loop_event = node_to_event(loop);
 496
 497                 /* we already found a later event, earlier can not block us, no need to check again */
 498                 if (loop_event->seqnum < event->delaying_seqnum)
 499                         continue;
 500
 501                 /* event we checked earlier still exists, no need to check again */
 502                 if (loop_event->seqnum == event->delaying_seqnum)
 503                         return true;
 504
 505                 /* found ourself, no later event can block us */
 506                 if (loop_event->seqnum >= event->seqnum)
 507                         break;
 508
 509                 /* check major/minor */
 510                 if (major(event->devnum) != 0 && event->devnum == loop_event->devnum && event->is_block == loop_event->is_block)
 511                         return true;
 512
 513                 /* check network device ifindex */
 514                 if (event->ifindex != 0 && event->ifindex == loop_event->ifindex)
 515                         return true;
 516
 517                 /* check our old name */
 518                 if (event->devpath_old != NULL && strcmp(loop_event->devpath, event->devpath_old) == 0) {
 519                         event->delaying_seqnum = loop_event->seqnum;
 520                         return true;
 521                 }
 522
 523                 /* compare devpath */
 524                 common = MIN(loop_event->devpath_len, event->devpath_len);
 525
 526                 /* one devpath is contained in the other? */
 527                 if (memcmp(loop_event->devpath, event->devpath, common) != 0)
 528                         continue;
 529
 530                 /* identical device event found */
 531                 if (loop_event->devpath_len == event->devpath_len) {
 532                         /* devices names might have changed/swapped in the meantime */
 533                         if (major(event->devnum) != 0 && (event->devnum != loop_event->devnum || event->is_block != loop_event->is_block))
 534                                 continue;
 535                         if (event->ifindex != 0 && event->ifindex != loop_event->ifindex)
 536                                 continue;
 537                         event->delaying_seqnum = loop_event->seqnum;
 538                         return true;
 539                 }
 540
 541                 /* parent device event found */
 542                 if (event->devpath[common] == '/') {
 543                         event->delaying_seqnum = loop_event->seqnum;
 544                         return true;
 545                 }
 546
 547                 /* child device event found */
 548                 if (loop_event->devpath[common] == '/') {
 549                         event->delaying_seqnum = loop_event->seqnum;
 550                         return true;
 551                 }
 552
 553                 /* no matching device */
 554                 continue;
 555         }
 556
 557         return false;
 558 }
 559
 560 static void event_queue_start(struct udev *udev)
 561 {
 562         struct udev_list_node *loop;
 563
 564         udev_list_node_foreach(loop, &event_list) {
 565                 struct event *event = node_to_event(loop);
 566
 567                 if (event->state != EVENT_QUEUED)
 568                         continue;
 569
 570                 /* do not start event if parent or child event is still running */
 571                 if (is_devpath_busy(event)) {
 572                         dbg(udev, "delay seq %llu (%s)\n", event->seqnum, event->devpath);
 573                         continue;
 574                 }
 575
 576                 event_run(event, false);
 577         }
 578 }
 579
 580 static void event_queue_cleanup(struct udev *udev, enum event_state match_type)
 581 {
 582         struct udev_list_node *loop, *tmp;
 583
 584         udev_list_node_foreach_safe(loop, tmp, &event_list) {
 585                 struct event *event = node_to_event(loop);
 586
 587                 if (match_type != EVENT_UNDEF && match_type != event->state)
 588                         continue;
 589
 590                 event_queue_delete(event, false);
 591         }
 592 }
 593
 594 static void worker_returned(int fd_worker)
 595 {
 596         for (;;) {
 597                 struct worker_message msg;
 598                 ssize_t size;
 599                 struct udev_list_node *loop;
 600
 601                 size = recv(fd_worker, &msg, sizeof(struct worker_message), MSG_DONTWAIT);
 602                 if (size != sizeof(struct worker_message))
 603                         break;
 604
 605                 /* lookup worker who sent the signal */
 606                 udev_list_node_foreach(loop, &worker_list) {
 607                         struct worker *worker = node_to_worker(loop);
 608
 609                         if (worker->pid != msg.pid)
 610                                 continue;
 611
 612                         /* worker returned */
 613                         worker->event->exitcode = msg.exitcode;
 614                         event_queue_delete(worker->event, true);
 615                         worker->event = NULL;
 616                         if (worker->state != WORKER_KILLED)
 617                                 worker->state = WORKER_IDLE;
 618                         worker_unref(worker);
 619                         break;
 620                 }
 621         }
 622 }
 623
 624 /* receive the udevd message from userspace */
 625 static struct udev_ctrl_connection *handle_ctrl_msg(struct udev_ctrl *uctrl)
 626 {
 627         struct udev *udev = udev_ctrl_get_udev(uctrl);
 628         struct udev_ctrl_connection *ctrl_conn;
 629         struct udev_ctrl_msg *ctrl_msg = NULL;
 630         const char *str;
 631         int i;
 632
 633         ctrl_conn = udev_ctrl_get_connection(uctrl);
 634         if (ctrl_conn == NULL)
 635                 goto out;
 636
 637         ctrl_msg = udev_ctrl_receive_msg(ctrl_conn);
 638         if (ctrl_msg == NULL)
 639                 goto out;
 640
 641         i = udev_ctrl_get_set_log_level(ctrl_msg);
 642         if (i >= 0) {
 643                 info(udev, "udevd message (SET_LOG_PRIORITY) received, log_priority=%i\n", i);
 644                 udev_set_log_priority(udev, i);
 645                 worker_kill(udev, 0);
 646         }
 647
 648         if (udev_ctrl_get_stop_exec_queue(ctrl_msg) > 0) {
 649                 info(udev, "udevd message (STOP_EXEC_QUEUE) received\n");
 650                 stop_exec_queue = true;
 651         }
 652
 653         if (udev_ctrl_get_start_exec_queue(ctrl_msg) > 0) {
 654                 info(udev, "udevd message (START_EXEC_QUEUE) received\n");
 655                 stop_exec_queue = false;
 656         }
 657
 658         if (udev_ctrl_get_reload(ctrl_msg) > 0) {
 659                 info(udev, "udevd message (RELOAD) received\n");
 660                 reload = true;
 661         }
 662
 663         str = udev_ctrl_get_set_env(ctrl_msg);
 664         if (str != NULL) {
 665                 char *key;
 666
 667                 key = strdup(str);
 668                 if (key != NULL) {
 669                         char *val;
 670
 671                         val = strchr(key, '=');
 672                         if (val != NULL) {
 673                                 val[0] = '\0';
 674                                 val = &val[1];
 675                                 if (val[0] == '\0') {
 676                                         info(udev, "udevd message (ENV) received, unset '%s'\n", key);
 677                                         udev_add_property(udev, key, NULL);
 678                                 } else {
 679                                         info(udev, "udevd message (ENV) received, set '%s=%s'\n", key, val);
 680                                         udev_add_property(udev, key, val);
 681                                 }
 682                         } else {
 683                                 err(udev, "wrong key format '%s'\n", key);
 684                         }
 685                         free(key);
 686                 }
 687                 worker_kill(udev, 0);
 688         }
 689
 690         i = udev_ctrl_get_set_children_max(ctrl_msg);
 691         if (i >= 0) {
 692                 info(udev, "udevd message (SET_MAX_CHILDREN) received, children_max=%i\n", i);
 693                 children_max = i;
 694         }
 695
 696         if (udev_ctrl_get_ping(ctrl_msg) > 0)
 697                 info(udev, "udevd message (SYNC) received\n");
 698
 699         if (udev_ctrl_get_exit(ctrl_msg) > 0) {
 700                 info(udev, "udevd message (EXIT) received\n");
 701                 udev_exit = true;
 702                 /* keep reference to block the client until we exit */
 703                 udev_ctrl_connection_ref(ctrl_conn);
 704         }
 705 out:
 706         udev_ctrl_msg_unref(ctrl_msg);
 707         return udev_ctrl_connection_unref(ctrl_conn);
 708 }
 709
 710 /* read inotify messages */
 711 static int handle_inotify(struct udev *udev)
 712 {
 713         int nbytes, pos;
 714         char *buf;
 715         struct inotify_event *ev;
 716
 717         if ((ioctl(fd_inotify, FIONREAD, &nbytes) < 0) || (nbytes <= 0))
 718                 return 0;
 719
 720         buf = malloc(nbytes);
 721         if (buf == NULL) {
 722                 err(udev, "error getting buffer for inotify\n");
 723                 return -1;
 724         }
 725
 726         nbytes = read(fd_inotify, buf, nbytes);
 727
 728         for (pos = 0; pos < nbytes; pos += sizeof(struct inotify_event) + ev->len) {
 729                 struct udev_device *dev;
 730
 731                 ev = (struct inotify_event *)(buf + pos);
 732                 dev = udev_watch_lookup(udev, ev->wd);
 733                 if (dev != NULL) {
 734                         info(udev, "inotify event: %x for %s\n", ev->mask, udev_device_get_devnode(dev));
 735                         if (ev->mask & IN_CLOSE_WRITE) {
 736                                 char filename[UTIL_PATH_SIZE];
 737                                 int fd;
 738
 739                                 info(udev, "device %s closed, synthesising 'change'\n", udev_device_get_devnode(dev));
 740                                 util_strscpyl(filename, sizeof(filename), udev_device_get_syspath(dev), "/uevent", NULL);
 741                                 fd = open(filename, O_WRONLY);
 742                                 if (fd >= 0) {
 743                                         if (write(fd, "change", 6) < 0)
 744                                                 info(udev, "error writing uevent: %m\n");
 745                                         close(fd);
 746                                 }
 747                         }
 748                         if (ev->mask & IN_IGNORED)
 749                                 udev_watch_end(udev, dev);
 750
 751                         udev_device_unref(dev);
 752                 }
 753
 754         }
 755
 756         free(buf);
 757         return 0;
 758 }
 759
 760 static void handle_signal(struct udev *udev, int signo)
 761 {
 762         switch (signo) {
 763         case SIGINT:
 764         case SIGTERM:
 765                 udev_exit = true;
 766                 break;
 767         case SIGCHLD:
 768                 for (;;) {
 769                         pid_t pid;
 770                         int status;
 771                         struct udev_list_node *loop, *tmp;
 772
 773                         pid = waitpid(-1, &status, WNOHANG);
 774                         if (pid <= 0)
 775                                 break;
 776
 777                         udev_list_node_foreach_safe(loop, tmp, &worker_list) {
 778                                 struct worker *worker = node_to_worker(loop);
 779
 780                                 if (worker->pid != pid)
 781                                         continue;
 782                                 info(udev, "worker [%u] exit\n", pid);
 783
 784                                 if (WIFEXITED(status)) {
 785                                         if (WEXITSTATUS(status) != 0)
 786                                                 err(udev, "worker [%u] exit with return code %i\n", pid, WEXITSTATUS(status));
 787                                 } else if (WIFSIGNALED(status)) {
 788                                         err(udev, "worker [%u] terminated by signal %i (%s)\n",
 789                                             pid, WTERMSIG(status), strsignal(WTERMSIG(status)));
 790                                 } else if (WIFSTOPPED(status)) {
 791                                         err(udev, "worker [%u] stopped\n", pid);
 792                                 } else if (WIFCONTINUED(status)) {
 793                                         err(udev, "worker [%u] continued\n", pid);
 794                                 } else {
 795                                         err(udev, "worker [%u] exit with status 0x%04x\n", pid, status);
 796                                 }
 797
 798                                 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
 799                                         if (worker->event != NULL) {
 800                                                 err(udev, "worker [%u] failed while handling '%s'\n",
 801                                                     pid, worker->event->devpath);
 802                                                 worker->event->exitcode = -32;
 803                                                 event_queue_delete(worker->event, true);
 804                                                 /* drop reference taken for state 'running' */
 805                                                 worker_unref(worker);
 806                                         }
 807                                 }
 808                                 worker_unref(worker);
 809                                 break;
 810                         }
 811                 }
 812                 break;
 813         case SIGHUP:
 814                 reload = true;
 815                 break;
 816         }
 817 }
 818
 819 static void static_dev_create_from_modules(struct udev *udev)
 820 {
 821         struct utsname kernel;
 822         char modules[UTIL_PATH_SIZE];
 823         char buf[4096];
 824         FILE *f;
 825
 826         uname(&kernel);
 827         util_strscpyl(modules, sizeof(modules), "/lib/modules/", kernel.release, "/modules.devname", NULL);
 828         f = fopen(modules, "r");
 829         if (f == NULL)
 830                 return;
 831
 832         while (fgets(buf, sizeof(buf), f) != NULL) {
 833                 char *s;
 834                 const char *modname;
 835                 const char *devname;
 836                 const char *devno;
 837                 int maj, min;
 838                 char type;
 839                 mode_t mode;
 840                 char filename[UTIL_PATH_SIZE];
 841
 842                 if (buf[0] == '#')
 843                         continue;
 844
 845                 modname = buf;
 846                 s = strchr(modname, ' ');
 847                 if (s == NULL)
 848                         continue;
 849                 s[0] = '\0';
 850
 851                 devname = &s[1];
 852                 s = strchr(devname, ' ');
 853                 if (s == NULL)
 854                         continue;
 855                 s[0] = '\0';
 856
 857                 devno = &s[1];
 858                 s = strchr(devno, ' ');
 859                 if (s == NULL)
 860                         s = strchr(devno, '\n');
 861                 if (s != NULL)
 862                         s[0] = '\0';
 863                 if (sscanf(devno, "%c%u:%u", &type, &maj, &min) != 3)
 864                         continue;
 865
 866                 /* set sticky bit, so we do not remove the node on module unload */
 867                 if (type == 'c')
 868                         mode = 01600|S_IFCHR;
 869                 else if (type == 'b')
 870                         mode = 01600|S_IFBLK;
 871                 else
 872                         continue;
 873
 874                 util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev), "/", devname, NULL);
 875                 util_create_path_selinux(udev, filename);
 876                 udev_selinux_setfscreatecon(udev, filename, mode);
 877                 info(udev, "mknod '%s' %c%u:%u\n", filename, type, maj, min);
 878                 if (mknod(filename, mode, makedev(maj, min)) < 0 && errno == EEXIST)
 879                         utimensat(AT_FDCWD, filename, NULL, 0);
 880                 udev_selinux_resetfscreatecon(udev);
 881         }
 882
 883         fclose(f);
 884 }
 885
 886 static int copy_dev_dir(struct udev *udev, DIR *dir_from, DIR *dir_to, int maxdepth)
 887 {
 888         struct dirent *dent;
 889
 890         for (dent = readdir(dir_from); dent != NULL; dent = readdir(dir_from)) {
 891                 struct stat stats;
 892
 893                 if (dent->d_name[0] == '.')
 894                         continue;
 895                 if (fstatat(dirfd(dir_from), dent->d_name, &stats, AT_SYMLINK_NOFOLLOW) != 0)
 896                         continue;
 897
 898                 if (S_ISBLK(stats.st_mode) || S_ISCHR(stats.st_mode)) {
 899                         udev_selinux_setfscreateconat(udev, dirfd(dir_to), dent->d_name, stats.st_mode & 0777);
 900                         if (mknodat(dirfd(dir_to), dent->d_name, stats.st_mode, stats.st_rdev) == 0) {
 901                                 fchmodat(dirfd(dir_to), dent->d_name, stats.st_mode & 0777, 0);
 902                                 fchownat(dirfd(dir_to), dent->d_name, stats.st_uid, stats.st_gid, 0);
 903                         } else {
 904                                 utimensat(dirfd(dir_to), dent->d_name, NULL, 0);
 905                         }
 906                         udev_selinux_resetfscreatecon(udev);
 907                 } else if (S_ISLNK(stats.st_mode)) {
 908                         char target[UTIL_PATH_SIZE];
 909                         ssize_t len;
 910
 911                         len = readlinkat(dirfd(dir_from), dent->d_name, target, sizeof(target));
 912                         if (len <= 0 || len == (ssize_t)sizeof(target))
 913                                 continue;
 914                         target[len] = '\0';
 915                         udev_selinux_setfscreateconat(udev, dirfd(dir_to), dent->d_name, S_IFLNK);
 916                         if (symlinkat(target, dirfd(dir_to), dent->d_name) < 0 && errno == EEXIST)
 917                                 utimensat(dirfd(dir_to), dent->d_name, NULL, AT_SYMLINK_NOFOLLOW);
 918                         udev_selinux_resetfscreatecon(udev);
 919                 } else if (S_ISDIR(stats.st_mode)) {
 920                         DIR *dir2_from, *dir2_to;
 921
 922                         if (maxdepth == 0)
 923                                 continue;
 924
 925                         udev_selinux_setfscreateconat(udev, dirfd(dir_to), dent->d_name, S_IFDIR|0755);
 926                         mkdirat(dirfd(dir_to), dent->d_name, 0755);
 927                         udev_selinux_resetfscreatecon(udev);
 928
 929                         dir2_to = fdopendir(openat(dirfd(dir_to), dent->d_name, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC));
 930                         if (dir2_to == NULL)
 931                                 continue;
 932
 933                         dir2_from = fdopendir(openat(dirfd(dir_from), dent->d_name, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC));
 934                         if (dir2_from == NULL) {
 935                                 closedir(dir2_to);
 936                                 continue;
 937                         }
 938
 939                         copy_dev_dir(udev, dir2_from, dir2_to, maxdepth-1);
 940
 941                         closedir(dir2_to);
 942                         closedir(dir2_from);
 943                 }
 944         }
 945
 946         return 0;
 947 }
 948
 949 static void static_dev_create_links(struct udev *udev, DIR *dir)
 950 {
 951         struct stdlinks {
 952                 const char *link;
 953                 const char *target;
 954         };
 955         static const struct stdlinks stdlinks[] = {
 956                 { "core", "/proc/kcore" },
 957                 { "fd", "/proc/self/fd" },
 958                 { "stdin", "/proc/self/fd/0" },
 959                 { "stdout", "/proc/self/fd/1" },
 960                 { "stderr", "/proc/self/fd/2" },
 961         };
 962         unsigned int i;
 963
 964         for (i = 0; i < ARRAY_SIZE(stdlinks); i++) {
 965                 struct stat sb;
 966
 967                 if (stat(stdlinks[i].target, &sb) == 0) {
 968                         udev_selinux_setfscreateconat(udev, dirfd(dir), stdlinks[i].link, S_IFLNK);
 969                         if (symlinkat(stdlinks[i].target, dirfd(dir), stdlinks[i].link) < 0 && errno == EEXIST)
 970                                 utimensat(dirfd(dir), stdlinks[i].link, NULL, AT_SYMLINK_NOFOLLOW);
 971                         udev_selinux_resetfscreatecon(udev);
 972                 }
 973         }
 974 }
 975
 976 static void static_dev_create_from_devices(struct udev *udev, DIR *dir)
 977 {
 978         DIR *dir_from;
 979
 980         dir_from = opendir(LIBEXECDIR "/devices");
 981         if (dir_from == NULL)
 982                 return;
 983         copy_dev_dir(udev, dir_from, dir, 8);
 984         closedir(dir_from);
 985 }
 986
 987 static void static_dev_create(struct udev *udev)
 988 {
 989         DIR *dir;
 990
 991         dir = opendir(udev_get_dev_path(udev));
 992         if (dir == NULL)
 993                 return;
 994
 995         static_dev_create_links(udev, dir);
 996         static_dev_create_from_devices(udev, dir);
 997
 998         closedir(dir);
 999 }
1000
1001 static int mem_size_mb(void)
1002 {
1003         FILE *f;
1004         char buf[4096];
1005         long int memsize = -1;
1006
1007         f = fopen("/proc/meminfo", "r");
1008         if (f == NULL)
1009                 return -1;
1010
1011         while (fgets(buf, sizeof(buf), f) != NULL) {
1012                 long int value;
1013
1014                 if (sscanf(buf, "MemTotal: %ld kB", &value) == 1) {
1015                         memsize = value / 1024;
1016                         break;
1017                 }
1018         }
1019
1020         fclose(f);
1021         return memsize;
1022 }
1023
1024 static int convert_db(struct udev *udev)
1025 {
1026         char filename[UTIL_PATH_SIZE];
1027         FILE *f;
1028         struct udev_enumerate *udev_enumerate;
1029         struct udev_list_entry *list_entry;
1030
1031         /* current database */
1032         util_strscpyl(filename, sizeof(filename), udev_get_run_path(udev), "/data", NULL);
1033         if (access(filename, F_OK) >= 0)
1034                 return 0;
1035
1036         /* make sure we do not get here again */
1037         util_create_path(udev, filename);
1038         mkdir(filename, 0755);
1039
1040         /* old database */
1041         util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev), "/.udev/db", NULL);
1042         if (access(filename, F_OK) < 0)
1043                 return 0;
1044
1045         f = fopen("/dev/kmsg", "w");
1046         if (f != NULL) {
1047                 fprintf(f, "<30>udevd[%u]: converting old udev database\n", getpid());
1048                 fclose(f);
1049         }
1050
1051         udev_enumerate = udev_enumerate_new(udev);
1052         if (udev_enumerate == NULL)
1053                 return -1;
1054         udev_enumerate_scan_devices(udev_enumerate);
1055         udev_list_entry_foreach(list_entry, udev_enumerate_get_list_entry(udev_enumerate)) {
1056                 struct udev_device *device;
1057
1058                 device = udev_device_new_from_syspath(udev, udev_list_entry_get_name(list_entry));
1059                 if (device == NULL)
1060                         continue;
1061
1062                 /* try to find the old database for devices without a current one */
1063                 if (udev_device_read_db(device, NULL) < 0) {
1064                         bool have_db;
1065                         const char *id;
1066                         struct stat stats;
1067                         char devpath[UTIL_PATH_SIZE];
1068                         char from[UTIL_PATH_SIZE];
1069
1070                         have_db = false;
1071
1072                         /* find database in old location */
1073                         id = udev_device_get_id_filename(device);
1074                         util_strscpyl(from, sizeof(from), udev_get_dev_path(udev), "/.udev/db/", id, NULL);
1075                         if (lstat(from, &stats) == 0) {
1076                                 if (!have_db) {
1077                                         udev_device_read_db(device, from);
1078                                         have_db = true;
1079                                 }
1080                                 unlink(from);
1081                         }
1082
1083                         /* find old database with $subsys:$sysname name */
1084                         util_strscpyl(from, sizeof(from), udev_get_dev_path(udev),
1085                                      "/.udev/db/", udev_device_get_subsystem(device), ":",
1086                                      udev_device_get_sysname(device), NULL);
1087                         if (lstat(from, &stats) == 0) {
1088                                 if (!have_db) {
1089                                         udev_device_read_db(device, from);
1090                                         have_db = true;
1091                                 }
1092                                 unlink(from);
1093                         }
1094
1095                         /* find old database with the encoded devpath name */
1096                         util_path_encode(udev_device_get_devpath(device), devpath, sizeof(devpath));
1097                         util_strscpyl(from, sizeof(from), udev_get_dev_path(udev), "/.udev/db/", devpath, NULL);
1098                         if (lstat(from, &stats) == 0) {
1099                                 if (!have_db) {
1100                                         udev_device_read_db(device, from);
1101                                         have_db = true;
1102                                 }
1103                                 unlink(from);
1104                         }
1105
1106                         /* write out new database */
1107                         if (have_db)
1108                                 udev_device_update_db(device);
1109                 }
1110                 udev_device_unref(device);
1111         }
1112         udev_enumerate_unref(udev_enumerate);
1113         return 0;
1114 }
1115
1116 static int systemd_fds(struct udev *udev, int *rctrl, int *rnetlink)
1117 {
1118         int ctrl = -1, netlink = -1;
1119         int fd, n;
1120
1121         n = sd_listen_fds(true);
1122         if (n <= 0)
1123                 return -1;
1124
1125         for (fd = SD_LISTEN_FDS_START; fd < n + SD_LISTEN_FDS_START; fd++) {
1126                 if (sd_is_socket(fd, AF_LOCAL, SOCK_SEQPACKET, -1)) {
1127                         if (ctrl >= 0)
1128                                 return -1;
1129                         ctrl = fd;
1130                         continue;
1131                 }
1132
1133                 if (sd_is_socket(fd, AF_NETLINK, SOCK_RAW, -1)) {
1134                         if (netlink >= 0)
1135                                 return -1;
1136                         netlink = fd;
1137                         continue;
1138                 }
1139
1140                 return -1;
1141         }
1142
1143         if (ctrl < 0 || netlink < 0)
1144                 return -1;
1145
1146         info(udev, "ctrl=%i netlink=%i\n", ctrl, netlink);
1147         *rctrl = ctrl;
1148         *rnetlink = netlink;
1149         return 0;
1150 }
1151
1152 static bool check_rules_timestamp(struct udev *udev)
1153 {
1154         char **p;
1155         unsigned long long *stamp_usec;
1156         int i, n;
1157         bool changed = false;
1158
1159         n = udev_get_rules_path(udev, &p, &stamp_usec);
1160         for (i = 0; i < n; i++) {
1161                 struct stat stats;
1162
1163                 if (stat(p[i], &stats) < 0)
1164                         continue;
1165
1166                 if (stamp_usec[i] == ts_usec(&stats.st_mtim))
1167                         continue;
1168
1169                 /* first check */
1170                 if (stamp_usec[i] != 0) {
1171                         info(udev, "reload - timestamp of '%s' changed\n", p[i]);
1172                         changed = true;
1173                 }
1174
1175                 /* update timestamp */
1176                 stamp_usec[i] = ts_usec(&stats.st_mtim);
1177         }
1178
1179         return changed;
1180 }
1181
1182 int main(int argc, char *argv[])
1183 {
1184         struct udev *udev;
1185         FILE *f;
1186         sigset_t mask;
1187         int daemonize = false;
1188         int resolve_names = 1;
1189         static const struct option options[] = {
1190                 { "daemon", no_argument, NULL, 'd' },
1191                 { "debug", no_argument, NULL, 'D' },
1192                 { "children-max", required_argument, NULL, 'c' },
1193                 { "exec-delay", required_argument, NULL, 'e' },
1194                 { "resolve-names", required_argument, NULL, 'N' },
1195                 { "help", no_argument, NULL, 'h' },
1196                 { "version", no_argument, NULL, 'V' },
1197                 {}
1198         };
1199         int fd_ctrl = -1;
1200         int fd_netlink = -1;
1201         int fd_worker = -1;
1202         struct epoll_event ep_ctrl, ep_inotify, ep_signal, ep_netlink, ep_worker;
1203         struct udev_ctrl_connection *ctrl_conn = NULL;
1204         char **s;
1205         int rc = 1;
1206
1207         udev = udev_new();
1208         if (udev == NULL)
1209                 goto exit;
1210
1211         udev_log_init("udevd");
1212         udev_set_log_fn(udev, udev_main_log);
1213         info(udev, "version %s\n", VERSION);
1214         udev_selinux_init(udev);
1215
1216         for (;;) {
1217                 int option;
1218
1219                 option = getopt_long(argc, argv, "c:deDtN:hV", options, NULL);
1220                 if (option == -1)
1221                         break;
1222
1223                 switch (option) {
1224                 case 'd':
1225                         daemonize = true;
1226                         break;
1227                 case 'c':
1228                         children_max = strtoul(optarg, NULL, 0);
1229                         break;
1230                 case 'e':
1231                         exec_delay = strtoul(optarg, NULL, 0);
1232                         break;
1233                 case 'D':
1234                         debug = true;
1235                         if (udev_get_log_priority(udev) < LOG_INFO)
1236                                 udev_set_log_priority(udev, LOG_INFO);
1237                         break;
1238                 case 'N':
1239                         if (strcmp (optarg, "early") == 0) {
1240                                 resolve_names = 1;
1241                         } else if (strcmp (optarg, "late") == 0) {
1242                                 resolve_names = 0;
1243                         } else if (strcmp (optarg, "never") == 0) {
1244                                 resolve_names = -1;
1245                         } else {
1246                                 fprintf(stderr, "resolve-names must be early, late or never\n");
1247                                 err(udev, "resolve-names must be early, late or never\n");
1248                                 goto exit;
1249                         }
1250                         break;
1251                 case 'h':
1252                         printf("Usage: udevd OPTIONS\n"
1253                                "  --daemon\n"
1254                                "  --debug\n"
1255                                "  --children-max=<maximum number of workers>\n"
1256                                "  --exec-delay=<seconds to wait before executing RUN=>\n"
1257                                "  --resolve-names=early|late|never\n"
1258                                "  --version\n"
1259                                "  --help\n"
1260                                "\n");
1261                         goto exit;
1262                 case 'V':
1263                         printf("%s\n", VERSION);
1264                         goto exit;
1265                 default:
1266                         goto exit;
1267                 }
1268         }
1269
1270         /*
1271          * read the kernel commandline, in case we need to get into debug mode
1272          *   udev.log-priority=<level>              syslog priority
1273          *   udev.children-max=<number of workers>  events are fully serialized if set to 1
1274          *
1275          */
1276         f = fopen("/proc/cmdline", "r");
1277         if (f != NULL) {
1278                 char cmdline[4096];
1279
1280                 if (fgets(cmdline, sizeof(cmdline), f) != NULL) {
1281                         char *pos;
1282
1283                         pos = strstr(cmdline, "udev.log-priority=");
1284                         if (pos != NULL) {
1285                                 pos += strlen("udev.log-priority=");
1286                                 udev_set_log_priority(udev, util_log_priority(pos));
1287                         }
1288
1289                         pos = strstr(cmdline, "udev.children-max=");
1290                         if (pos != NULL) {
1291                                 pos += strlen("udev.children-max=");
1292                                 children_max = strtoul(pos, NULL, 0);
1293                         }
1294
1295                         pos = strstr(cmdline, "udev.exec-delay=");
1296                         if (pos != NULL) {
1297                                 pos += strlen("udev.exec-delay=");
1298                                 exec_delay = strtoul(pos, NULL, 0);
1299                         }
1300                 }
1301                 fclose(f);
1302         }
1303
1304         if (getuid() != 0) {
1305                 fprintf(stderr, "root privileges required\n");
1306                 err(udev, "root privileges required\n");
1307                 goto exit;
1308         }
1309
1310         /* set umask before creating any file/directory */
1311         chdir("/");
1312         umask(022);
1313
1314         /* /run/udev */
1315         mkdir(udev_get_run_path(udev), 0755);
1316
1317         /* create standard links, copy static nodes, create nodes from modules */
1318         static_dev_create(udev);
1319         static_dev_create_from_modules(udev);
1320
1321         /* before opening new files, make sure std{in,out,err} fds are in a sane state */
1322         if (daemonize) {
1323                 int fd;
1324
1325                 fd = open("/dev/null", O_RDWR);
1326                 if (fd >= 0) {
1327                         if (write(STDOUT_FILENO, 0, 0) < 0)
1328                                 dup2(fd, STDOUT_FILENO);
1329                         if (write(STDERR_FILENO, 0, 0) < 0)
1330                                 dup2(fd, STDERR_FILENO);
1331                         if (fd > STDERR_FILENO)
1332                                 close(fd);
1333                 } else {
1334                         fprintf(stderr, "cannot open /dev/null\n");
1335                         err(udev, "cannot open /dev/null\n");
1336                 }
1337         }
1338
1339         if (systemd_fds(udev, &fd_ctrl, &fd_netlink) >= 0) {
1340                 /* get control and netlink socket from from systemd */
1341                 udev_ctrl = udev_ctrl_new_from_fd(udev, fd_ctrl);
1342                 if (udev_ctrl == NULL) {
1343                         err(udev, "error taking over udev control socket");
1344                         rc = 1;
1345                         goto exit;
1346                 }
1347
1348                 monitor = udev_monitor_new_from_netlink_fd(udev, "kernel", fd_netlink);
1349                 if (monitor == NULL) {
1350                         err(udev, "error taking over netlink socket\n");
1351                         rc = 3;
1352                         goto exit;
1353                 }
1354         } else {
1355                 /* open control and netlink socket */
1356                 udev_ctrl = udev_ctrl_new(udev);
1357                 if (udev_ctrl == NULL) {
1358                         fprintf(stderr, "error initializing udev control socket");
1359                         err(udev, "error initializing udev control socket");
1360                         rc = 1;
1361                         goto exit;
1362                 }
1363                 fd_ctrl = udev_ctrl_get_fd(udev_ctrl);
1364
1365                 monitor = udev_monitor_new_from_netlink(udev, "kernel");
1366                 if (monitor == NULL) {
1367                         fprintf(stderr, "error initializing netlink socket\n");
1368                         err(udev, "error initializing netlink socket\n");
1369                         rc = 3;
1370                         goto exit;
1371                 }
1372                 fd_netlink = udev_monitor_get_fd(monitor);
1373         }
1374
1375         if (udev_monitor_enable_receiving(monitor) < 0) {
1376                 fprintf(stderr, "error binding netlink socket\n");
1377                 err(udev, "error binding netlink socket\n");
1378                 rc = 3;
1379                 goto exit;
1380         }
1381
1382         if (udev_ctrl_enable_receiving(udev_ctrl) < 0) {
1383                 fprintf(stderr, "error binding udev control socket\n");
1384                 err(udev, "error binding udev control socket\n");
1385                 rc = 1;
1386                 goto exit;
1387         }
1388
1389         udev_monitor_set_receive_buffer_size(monitor, 128*1024*1024);
1390
1391         /* create queue file before signalling 'ready', to make sure we block 'settle' */
1392         udev_queue_export = udev_queue_export_new(udev);
1393         if (udev_queue_export == NULL) {
1394                 err(udev, "error creating queue file\n");
1395                 goto exit;
1396         }
1397
1398         if (daemonize) {
1399                 pid_t pid;
1400                 int fd;
1401
1402                 pid = fork();
1403                 switch (pid) {
1404                 case 0:
1405                         break;
1406                 case -1:
1407                         err(udev, "fork of daemon failed: %m\n");
1408                         rc = 4;
1409                         goto exit;
1410                 default:
1411                         rc = EXIT_SUCCESS;
1412                         goto exit_daemonize;
1413                 }
1414
1415                 setsid();
1416
1417                 fd = open("/proc/self/oom_score_adj", O_RDWR);
1418                 if (fd < 0) {
1419                         /* Fallback to old interface */
1420                         fd = open("/proc/self/oom_adj", O_RDWR);
1421                         if (fd < 0) {
1422                                 err(udev, "error disabling OOM: %m\n");
1423                         } else {
1424                                 /* OOM_DISABLE == -17 */
1425                                 write(fd, "-17", 3);
1426                                 close(fd);
1427                         }
1428                 } else {
1429                         write(fd, "-1000", 5);
1430                         close(fd);
1431                 }
1432         } else {
1433                 sd_notify(1, "READY=1");
1434         }
1435
1436         f = fopen("/dev/kmsg", "w");
1437         if (f != NULL) {
1438                 fprintf(f, "<30>udevd[%u]: starting version " VERSION "\n", getpid());
1439                 fclose(f);
1440         }
1441
1442         if (!debug) {
1443                 int fd;
1444
1445                 fd = open("/dev/null", O_RDWR);
1446                 if (fd >= 0) {
1447                         dup2(fd, STDIN_FILENO);
1448                         dup2(fd, STDOUT_FILENO);
1449                         dup2(fd, STDERR_FILENO);
1450                         close(fd);
1451                 }
1452         }
1453
1454         fd_inotify = udev_watch_init(udev);
1455         if (fd_inotify < 0) {
1456                 fprintf(stderr, "error initializing inotify\n");
1457                 err(udev, "error initializing inotify\n");
1458                 rc = 4;
1459                 goto exit;
1460         }
1461         udev_watch_restore(udev);
1462
1463         /* block and listen to all signals on signalfd */
1464         sigfillset(&mask);
1465         sigprocmask(SIG_SETMASK, &mask, &sigmask_orig);
1466         fd_signal = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC);
1467         if (fd_signal < 0) {
1468                 fprintf(stderr, "error creating signalfd\n");
1469                 err(udev, "error creating signalfd\n");
1470                 rc = 5;
1471                 goto exit;
1472         }
1473
1474         /* unnamed socket from workers to the main daemon */
1475         if (socketpair(AF_LOCAL, SOCK_DGRAM|SOCK_CLOEXEC, 0, worker_watch) < 0) {
1476                 fprintf(stderr, "error creating socketpair\n");
1477                 err(udev, "error creating socketpair\n");
1478                 rc = 6;
1479                 goto exit;
1480         }
1481         fd_worker = worker_watch[READ_END];
1482
1483         udev_builtin_init(udev);
1484
1485         rules = udev_rules_new(udev, resolve_names);
1486         if (rules == NULL) {
1487                 err(udev, "error reading rules\n");
1488                 goto exit;
1489         }
1490
1491         memset(&ep_ctrl, 0, sizeof(struct epoll_event));
1492         ep_ctrl.events = EPOLLIN;
1493         ep_ctrl.data.fd = fd_ctrl;
1494
1495         memset(&ep_inotify, 0, sizeof(struct epoll_event));
1496         ep_inotify.events = EPOLLIN;
1497         ep_inotify.data.fd = fd_inotify;
1498
1499         memset(&ep_signal, 0, sizeof(struct epoll_event));
1500         ep_signal.events = EPOLLIN;
1501         ep_signal.data.fd = fd_signal;
1502
1503         memset(&ep_netlink, 0, sizeof(struct epoll_event));
1504         ep_netlink.events = EPOLLIN;
1505         ep_netlink.data.fd = fd_netlink;
1506
1507         memset(&ep_worker, 0, sizeof(struct epoll_event));
1508         ep_worker.events = EPOLLIN;
1509         ep_worker.data.fd = fd_worker;
1510
1511         fd_ep = epoll_create1(EPOLL_CLOEXEC);
1512         if (fd_ep < 0) {
1513                 err(udev, "error creating epoll fd: %m\n");
1514                 goto exit;
1515         }
1516         if (epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_ctrl, &ep_ctrl) < 0 ||
1517             epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_inotify, &ep_inotify) < 0 ||
1518             epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_signal, &ep_signal) < 0 ||
1519             epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_netlink, &ep_netlink) < 0 ||
1520             epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_worker, &ep_worker) < 0) {
1521                 err(udev, "fail to add fds to epoll: %m\n");
1522                 goto exit;
1523         }
1524
1525         /* if needed, convert old database from earlier udev version */
1526         convert_db(udev);
1527
1528         if (children_max <= 0) {
1529                 int memsize = mem_size_mb();
1530
1531                 /* set value depending on the amount of RAM */
1532                 if (memsize > 0)
1533                         children_max = 128 + (memsize / 8);
1534                 else
1535                         children_max = 128;
1536         }
1537         info(udev, "set children_max to %u\n", children_max);
1538
1539         udev_rules_apply_static_dev_perms(rules);
1540
1541         udev_list_node_init(&event_list);
1542         udev_list_node_init(&worker_list);
1543
1544         for (;;) {
1545                 static unsigned long long last_usec;
1546                 struct epoll_event ev[8];
1547                 int fdcount;
1548                 int timeout;
1549                 bool is_worker, is_signal, is_inotify, is_netlink, is_ctrl;
1550                 int i;
1551
1552                 if (udev_exit) {
1553                         /* close sources of new events and discard buffered events */
1554                         if (fd_ctrl >= 0) {
1555                                 epoll_ctl(fd_ep, EPOLL_CTL_DEL, fd_ctrl, NULL);
1556                                 fd_ctrl = -1;
1557                         }
1558                         if (monitor != NULL) {
1559                                 epoll_ctl(fd_ep, EPOLL_CTL_DEL, fd_netlink, NULL);
1560                                 udev_monitor_unref(monitor);
1561                                 monitor = NULL;
1562                         }
1563                         if (fd_inotify >= 0) {
1564                                 epoll_ctl(fd_ep, EPOLL_CTL_DEL, fd_inotify, NULL);
1565                                 close(fd_inotify);
1566                                 fd_inotify = -1;
1567                         }
1568
1569                         /* discard queued events and kill workers */
1570                         event_queue_cleanup(udev, EVENT_QUEUED);
1571                         worker_kill(udev, 0);
1572
1573                         /* exit after all has cleaned up */
1574                         if (udev_list_node_is_empty(&event_list) && udev_list_node_is_empty(&worker_list))
1575                                 break;
1576
1577                         /* timeout at exit for workers to finish */
1578                         timeout = 60 * 1000;
1579                 } else if (udev_list_node_is_empty(&event_list) && children > 2) {
1580                         /* set timeout to kill idle workers */
1581                         timeout = 3 * 1000;
1582                 } else {
1583                         timeout = -1;
1584                 }
1585                 fdcount = epoll_wait(fd_ep, ev, ARRAY_SIZE(ev), timeout);
1586                 if (fdcount < 0)
1587                         continue;
1588
1589                 if (fdcount == 0) {
1590                         if (udev_exit) {
1591                                 info(udev, "timeout, giving up waiting for workers to finish\n");
1592                                 break;
1593                         }
1594
1595                         /* timeout - kill idle workers */
1596                         worker_kill(udev, 2);
1597                 }
1598
1599                 is_worker = is_signal = is_inotify = is_netlink = is_ctrl = false;
1600                 for (i = 0; i < fdcount; i++) {
1601                         if (ev[i].data.fd == fd_worker && ev[i].events & EPOLLIN)
1602                                 is_worker = true;
1603                         else if (ev[i].data.fd == fd_netlink && ev[i].events & EPOLLIN)
1604                                 is_netlink = true;
1605                         else if (ev[i].data.fd == fd_signal && ev[i].events & EPOLLIN)
1606                                 is_signal = true;
1607                         else if (ev[i].data.fd == fd_inotify && ev[i].events & EPOLLIN)
1608                                 is_inotify = true;
1609                         else if (ev[i].data.fd == fd_ctrl && ev[i].events & EPOLLIN)
1610                                 is_ctrl = true;
1611                 }
1612
1613                 /* check for changed config, every 3 seconds at most */
1614                 if ((now_usec() - last_usec) > 3 * 1000 * 1000) {
1615                         if (check_rules_timestamp(udev))
1616                                 reload = true;
1617                         if (udev_builtin_validate(udev))
1618                                 reload = true;
1619
1620                         last_usec = now_usec();
1621                 }
1622
1623                 /* reload requested, HUP signal received, rules changed, builtin changed */
1624                 if (reload) {
1625                         worker_kill(udev, 0);
1626                         rules = udev_rules_unref(rules);
1627                         udev_builtin_exit(udev);
1628                         reload = 0;
1629                 }
1630
1631                 /* event has finished */
1632                 if (is_worker)
1633                         worker_returned(fd_worker);
1634
1635                 if (is_netlink) {
1636                         struct udev_device *dev;
1637
1638                         dev = udev_monitor_receive_device(monitor);
1639                         if (dev != NULL) {
1640                                 udev_device_set_usec_initialized(dev, now_usec());
1641                                 if (event_queue_insert(dev) < 0)
1642                                         udev_device_unref(dev);
1643                         }
1644                 }
1645
1646                 /* start new events */
1647                 if (!udev_list_node_is_empty(&event_list) && !udev_exit && !stop_exec_queue) {
1648                         if (rules == NULL)
1649                                 rules = udev_rules_new(udev, resolve_names);
1650                         if (rules != NULL)
1651                                 event_queue_start(udev);
1652                 }
1653
1654                 if (is_signal) {
1655                         struct signalfd_siginfo fdsi;
1656                         ssize_t size;
1657
1658                         size = read(fd_signal, &fdsi, sizeof(struct signalfd_siginfo));
1659                         if (size == sizeof(struct signalfd_siginfo))
1660                                 handle_signal(udev, fdsi.ssi_signo);
1661                 }
1662
1663                 /* we are shutting down, the events below are not handled anymore */
1664                 if (udev_exit)
1665                         continue;
1666
1667                 /* device node watch */
1668                 if (is_inotify)
1669                         handle_inotify(udev);
1670
1671                 /*
1672                  * This needs to be after the inotify handling, to make sure,
1673                  * that the ping is send back after the possibly generated
1674                  * "change" events by the inotify device node watch.
1675                  *
1676                  * A single time we may receive a client connection which we need to
1677                  * keep open to block the client. It will be closed right before we
1678                  * exit.
1679                  */
1680                 if (is_ctrl)
1681                         ctrl_conn = handle_ctrl_msg(udev_ctrl);
1682         }
1683
1684         rc = EXIT_SUCCESS;
1685 exit:
1686         udev_queue_export_cleanup(udev_queue_export);
1687         udev_ctrl_cleanup(udev_ctrl);
1688 exit_daemonize:
1689         if (fd_ep >= 0)
1690                 close(fd_ep);
1691         worker_list_cleanup(udev);
1692         event_queue_cleanup(udev, EVENT_UNDEF);
1693         udev_rules_unref(rules);
1694         udev_builtin_exit(udev);
1695         if (fd_signal >= 0)
1696                 close(fd_signal);
1697         if (worker_watch[READ_END] >= 0)
1698                 close(worker_watch[READ_END]);
1699         if (worker_watch[WRITE_END] >= 0)
1700                 close(worker_watch[WRITE_END]);
1701         udev_monitor_unref(monitor);
1702         udev_queue_export_unref(udev_queue_export);
1703         udev_ctrl_connection_unref(ctrl_conn);
1704         udev_ctrl_unref(udev_ctrl);
1705         udev_selinux_exit(udev);
1706         udev_unref(udev);
1707         udev_log_close();
1708         return rc;
1709 }