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
 461         /* run all events with a timeout set immediately */
 462         if (udev_device_get_timeout(dev) > 0) {
 463                 event_run(event, true);
 464                 return 0;
 465         }
 466
 467         return 0;
 468 }
 469
 470 static void worker_kill(struct udev *udev, int retain)
 471 {
 472         struct udev_list_node *loop;
 473         int max;
 474
 475         if (children <= retain)
 476                 return;
 477
 478         max = children - retain;
 479
 480         udev_list_node_foreach(loop, &worker_list) {
 481                 struct worker *worker = node_to_worker(loop);
 482
 483                 if (max-- <= 0)
 484                         break;
 485
 486                 if (worker->state == WORKER_KILLED)
 487                         continue;
 488
 489                 worker->state = WORKER_KILLED;
 490                 kill(worker->pid, SIGTERM);
 491         }
 492 }
 493
 494 /* lookup event for identical, parent, child device */
 495 static bool is_devpath_busy(struct event *event)
 496 {
 497         struct udev_list_node *loop;
 498         size_t common;
 499
 500         /* check if queue contains events we depend on */
 501         udev_list_node_foreach(loop, &event_list) {
 502                 struct event *loop_event = node_to_event(loop);
 503
 504                 /* we already found a later event, earlier can not block us, no need to check again */
 505                 if (loop_event->seqnum < event->delaying_seqnum)
 506                         continue;
 507
 508                 /* event we checked earlier still exists, no need to check again */
 509                 if (loop_event->seqnum == event->delaying_seqnum)
 510                         return true;
 511
 512                 /* found ourself, no later event can block us */
 513                 if (loop_event->seqnum >= event->seqnum)
 514                         break;
 515
 516                 /* check major/minor */
 517                 if (major(event->devnum) != 0 && event->devnum == loop_event->devnum && event->is_block == loop_event->is_block)
 518                         return true;
 519
 520                 /* check network device ifindex */
 521                 if (event->ifindex != 0 && event->ifindex == loop_event->ifindex)
 522                         return true;
 523
 524                 /* check our old name */
 525                 if (event->devpath_old != NULL && strcmp(loop_event->devpath, event->devpath_old) == 0) {
 526                         event->delaying_seqnum = loop_event->seqnum;
 527                         return true;
 528                 }
 529
 530                 /* compare devpath */
 531                 common = MIN(loop_event->devpath_len, event->devpath_len);
 532
 533                 /* one devpath is contained in the other? */
 534                 if (memcmp(loop_event->devpath, event->devpath, common) != 0)
 535                         continue;
 536
 537                 /* identical device event found */
 538                 if (loop_event->devpath_len == event->devpath_len) {
 539                         /* devices names might have changed/swapped in the meantime */
 540                         if (major(event->devnum) != 0 && (event->devnum != loop_event->devnum || event->is_block != loop_event->is_block))
 541                                 continue;
 542                         if (event->ifindex != 0 && event->ifindex != loop_event->ifindex)
 543                                 continue;
 544                         event->delaying_seqnum = loop_event->seqnum;
 545                         return true;
 546                 }
 547
 548                 /* parent device event found */
 549                 if (event->devpath[common] == '/') {
 550                         event->delaying_seqnum = loop_event->seqnum;
 551                         return true;
 552                 }
 553
 554                 /* child device event found */
 555                 if (loop_event->devpath[common] == '/') {
 556                         event->delaying_seqnum = loop_event->seqnum;
 557                         return true;
 558                 }
 559
 560                 /* no matching device */
 561                 continue;
 562         }
 563
 564         return false;
 565 }
 566
 567 static void event_queue_start(struct udev *udev)
 568 {
 569         struct udev_list_node *loop;
 570
 571         udev_list_node_foreach(loop, &event_list) {
 572                 struct event *event = node_to_event(loop);
 573
 574                 if (event->state != EVENT_QUEUED)
 575                         continue;
 576
 577                 /* do not start event if parent or child event is still running */
 578                 if (is_devpath_busy(event)) {
 579                         dbg(udev, "delay seq %llu (%s)\n", event->seqnum, event->devpath);
 580                         continue;
 581                 }
 582
 583                 event_run(event, false);
 584         }
 585 }
 586
 587 static void event_queue_cleanup(struct udev *udev, enum event_state match_type)
 588 {
 589         struct udev_list_node *loop, *tmp;
 590
 591         udev_list_node_foreach_safe(loop, tmp, &event_list) {
 592                 struct event *event = node_to_event(loop);
 593
 594                 if (match_type != EVENT_UNDEF && match_type != event->state)
 595                         continue;
 596
 597                 event_queue_delete(event, false);
 598         }
 599 }
 600
 601 static void worker_returned(int fd_worker)
 602 {
 603         for (;;) {
 604                 struct worker_message msg;
 605                 ssize_t size;
 606                 struct udev_list_node *loop;
 607
 608                 size = recv(fd_worker, &msg, sizeof(struct worker_message), MSG_DONTWAIT);
 609                 if (size != sizeof(struct worker_message))
 610                         break;
 611
 612                 /* lookup worker who sent the signal */
 613                 udev_list_node_foreach(loop, &worker_list) {
 614                         struct worker *worker = node_to_worker(loop);
 615
 616                         if (worker->pid != msg.pid)
 617                                 continue;
 618
 619                         /* worker returned */
 620                         worker->event->exitcode = msg.exitcode;
 621                         event_queue_delete(worker->event, true);
 622                         worker->event = NULL;
 623                         if (worker->state != WORKER_KILLED)
 624                                 worker->state = WORKER_IDLE;
 625                         worker_unref(worker);
 626                         break;
 627                 }
 628         }
 629 }
 630
 631 /* receive the udevd message from userspace */
 632 static struct udev_ctrl_connection *handle_ctrl_msg(struct udev_ctrl *uctrl)
 633 {
 634         struct udev *udev = udev_ctrl_get_udev(uctrl);
 635         struct udev_ctrl_connection *ctrl_conn;
 636         struct udev_ctrl_msg *ctrl_msg = NULL;
 637         const char *str;
 638         int i;
 639
 640         ctrl_conn = udev_ctrl_get_connection(uctrl);
 641         if (ctrl_conn == NULL)
 642                 goto out;
 643
 644         ctrl_msg = udev_ctrl_receive_msg(ctrl_conn);
 645         if (ctrl_msg == NULL)
 646                 goto out;
 647
 648         i = udev_ctrl_get_set_log_level(ctrl_msg);
 649         if (i >= 0) {
 650                 info(udev, "udevd message (SET_LOG_PRIORITY) received, log_priority=%i\n", i);
 651                 udev_set_log_priority(udev, i);
 652                 worker_kill(udev, 0);
 653         }
 654
 655         if (udev_ctrl_get_stop_exec_queue(ctrl_msg) > 0) {
 656                 info(udev, "udevd message (STOP_EXEC_QUEUE) received\n");
 657                 stop_exec_queue = true;
 658         }
 659
 660         if (udev_ctrl_get_start_exec_queue(ctrl_msg) > 0) {
 661                 info(udev, "udevd message (START_EXEC_QUEUE) received\n");
 662                 stop_exec_queue = false;
 663         }
 664
 665         if (udev_ctrl_get_reload(ctrl_msg) > 0) {
 666                 info(udev, "udevd message (RELOAD) received\n");
 667                 reload = true;
 668         }
 669
 670         str = udev_ctrl_get_set_env(ctrl_msg);
 671         if (str != NULL) {
 672                 char *key;
 673
 674                 key = strdup(str);
 675                 if (key != NULL) {
 676                         char *val;
 677
 678                         val = strchr(key, '=');
 679                         if (val != NULL) {
 680                                 val[0] = '\0';
 681                                 val = &val[1];
 682                                 if (val[0] == '\0') {
 683                                         info(udev, "udevd message (ENV) received, unset '%s'\n", key);
 684                                         udev_add_property(udev, key, NULL);
 685                                 } else {
 686                                         info(udev, "udevd message (ENV) received, set '%s=%s'\n", key, val);
 687                                         udev_add_property(udev, key, val);
 688                                 }
 689                         } else {
 690                                 err(udev, "wrong key format '%s'\n", key);
 691                         }
 692                         free(key);
 693                 }
 694                 worker_kill(udev, 0);
 695         }
 696
 697         i = udev_ctrl_get_set_children_max(ctrl_msg);
 698         if (i >= 0) {
 699                 info(udev, "udevd message (SET_MAX_CHILDREN) received, children_max=%i\n", i);
 700                 children_max = i;
 701         }
 702
 703         if (udev_ctrl_get_ping(ctrl_msg) > 0)
 704                 info(udev, "udevd message (SYNC) received\n");
 705
 706         if (udev_ctrl_get_exit(ctrl_msg) > 0) {
 707                 info(udev, "udevd message (EXIT) received\n");
 708                 udev_exit = true;
 709                 /* keep reference to block the client until we exit */
 710                 udev_ctrl_connection_ref(ctrl_conn);
 711         }
 712 out:
 713         udev_ctrl_msg_unref(ctrl_msg);
 714         return udev_ctrl_connection_unref(ctrl_conn);
 715 }
 716
 717 /* read inotify messages */
 718 static int handle_inotify(struct udev *udev)
 719 {
 720         int nbytes, pos;
 721         char *buf;
 722         struct inotify_event *ev;
 723
 724         if ((ioctl(fd_inotify, FIONREAD, &nbytes) < 0) || (nbytes <= 0))
 725                 return 0;
 726
 727         buf = malloc(nbytes);
 728         if (buf == NULL) {
 729                 err(udev, "error getting buffer for inotify\n");
 730                 return -1;
 731         }
 732
 733         nbytes = read(fd_inotify, buf, nbytes);
 734
 735         for (pos = 0; pos < nbytes; pos += sizeof(struct inotify_event) + ev->len) {
 736                 struct udev_device *dev;
 737
 738                 ev = (struct inotify_event *)(buf + pos);
 739                 dev = udev_watch_lookup(udev, ev->wd);
 740                 if (dev != NULL) {
 741                         info(udev, "inotify event: %x for %s\n", ev->mask, udev_device_get_devnode(dev));
 742                         if (ev->mask & IN_CLOSE_WRITE) {
 743                                 char filename[UTIL_PATH_SIZE];
 744                                 int fd;
 745
 746                                 info(udev, "device %s closed, synthesising 'change'\n", udev_device_get_devnode(dev));
 747                                 util_strscpyl(filename, sizeof(filename), udev_device_get_syspath(dev), "/uevent", NULL);
 748                                 fd = open(filename, O_WRONLY);
 749                                 if (fd >= 0) {
 750                                         if (write(fd, "change", 6) < 0)
 751                                                 info(udev, "error writing uevent: %m\n");
 752                                         close(fd);
 753                                 }
 754                         }
 755                         if (ev->mask & IN_IGNORED)
 756                                 udev_watch_end(udev, dev);
 757
 758                         udev_device_unref(dev);
 759                 }
 760
 761         }
 762
 763         free(buf);
 764         return 0;
 765 }
 766
 767 static void handle_signal(struct udev *udev, int signo)
 768 {
 769         switch (signo) {
 770         case SIGINT:
 771         case SIGTERM:
 772                 udev_exit = true;
 773                 break;
 774         case SIGCHLD:
 775                 for (;;) {
 776                         pid_t pid;
 777                         int status;
 778                         struct udev_list_node *loop, *tmp;
 779
 780                         pid = waitpid(-1, &status, WNOHANG);
 781                         if (pid <= 0)
 782                                 break;
 783
 784                         udev_list_node_foreach_safe(loop, tmp, &worker_list) {
 785                                 struct worker *worker = node_to_worker(loop);
 786
 787                                 if (worker->pid != pid)
 788                                         continue;
 789                                 info(udev, "worker [%u] exit\n", pid);
 790
 791                                 if (WIFEXITED(status)) {
 792                                         if (WEXITSTATUS(status) != 0)
 793                                                 err(udev, "worker [%u] exit with return code %i\n", pid, WEXITSTATUS(status));
 794                                 } else if (WIFSIGNALED(status)) {
 795                                         err(udev, "worker [%u] terminated by signal %i (%s)\n",
 796                                             pid, WTERMSIG(status), strsignal(WTERMSIG(status)));
 797                                 } else if (WIFSTOPPED(status)) {
 798                                         err(udev, "worker [%u] stopped\n", pid);
 799                                 } else if (WIFCONTINUED(status)) {
 800                                         err(udev, "worker [%u] continued\n", pid);
 801                                 } else {
 802                                         err(udev, "worker [%u] exit with status 0x%04x\n", pid, status);
 803                                 }
 804
 805                                 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
 806                                         if (worker->event != NULL) {
 807                                                 err(udev, "worker [%u] failed while handling '%s'\n",
 808                                                     pid, worker->event->devpath);
 809                                                 worker->event->exitcode = -32;
 810                                                 event_queue_delete(worker->event, true);
 811                                                 /* drop reference taken for state 'running' */
 812                                                 worker_unref(worker);
 813                                         }
 814                                 }
 815                                 worker_unref(worker);
 816                                 break;
 817                         }
 818                 }
 819                 break;
 820         case SIGHUP:
 821                 reload = true;
 822                 break;
 823         }
 824 }
 825
 826 static void static_dev_create_from_modules(struct udev *udev)
 827 {
 828         struct utsname kernel;
 829         char modules[UTIL_PATH_SIZE];
 830         char buf[4096];
 831         FILE *f;
 832
 833         uname(&kernel);
 834         util_strscpyl(modules, sizeof(modules), "/lib/modules/", kernel.release, "/modules.devname", NULL);
 835         f = fopen(modules, "r");
 836         if (f == NULL)
 837                 return;
 838
 839         while (fgets(buf, sizeof(buf), f) != NULL) {
 840                 char *s;
 841                 const char *modname;
 842                 const char *devname;
 843                 const char *devno;
 844                 int maj, min;
 845                 char type;
 846                 mode_t mode;
 847                 char filename[UTIL_PATH_SIZE];
 848
 849                 if (buf[0] == '#')
 850                         continue;
 851
 852                 modname = buf;
 853                 s = strchr(modname, ' ');
 854                 if (s == NULL)
 855                         continue;
 856                 s[0] = '\0';
 857
 858                 devname = &s[1];
 859                 s = strchr(devname, ' ');
 860                 if (s == NULL)
 861                         continue;
 862                 s[0] = '\0';
 863
 864                 devno = &s[1];
 865                 s = strchr(devno, ' ');
 866                 if (s == NULL)
 867                         s = strchr(devno, '\n');
 868                 if (s != NULL)
 869                         s[0] = '\0';
 870                 if (sscanf(devno, "%c%u:%u", &type, &maj, &min) != 3)
 871                         continue;
 872
 873                 /* set sticky bit, so we do not remove the node on module unload */
 874                 if (type == 'c')
 875                         mode = 01600|S_IFCHR;
 876                 else if (type == 'b')
 877                         mode = 01600|S_IFBLK;
 878                 else
 879                         continue;
 880
 881                 util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev), "/", devname, NULL);
 882                 util_create_path_selinux(udev, filename);
 883                 udev_selinux_setfscreatecon(udev, filename, mode);
 884                 info(udev, "mknod '%s' %c%u:%u\n", filename, type, maj, min);
 885                 if (mknod(filename, mode, makedev(maj, min)) < 0 && errno == EEXIST)
 886                         utimensat(AT_FDCWD, filename, NULL, 0);
 887                 udev_selinux_resetfscreatecon(udev);
 888         }
 889
 890         fclose(f);
 891 }
 892
 893 static int copy_dev_dir(struct udev *udev, DIR *dir_from, DIR *dir_to, int maxdepth)
 894 {
 895         struct dirent *dent;
 896
 897         for (dent = readdir(dir_from); dent != NULL; dent = readdir(dir_from)) {
 898                 struct stat stats;
 899
 900                 if (dent->d_name[0] == '.')
 901                         continue;
 902                 if (fstatat(dirfd(dir_from), dent->d_name, &stats, AT_SYMLINK_NOFOLLOW) != 0)
 903                         continue;
 904
 905                 if (S_ISBLK(stats.st_mode) || S_ISCHR(stats.st_mode)) {
 906                         udev_selinux_setfscreateconat(udev, dirfd(dir_to), dent->d_name, stats.st_mode & 0777);
 907                         if (mknodat(dirfd(dir_to), dent->d_name, stats.st_mode, stats.st_rdev) == 0) {
 908                                 fchmodat(dirfd(dir_to), dent->d_name, stats.st_mode & 0777, 0);
 909                                 fchownat(dirfd(dir_to), dent->d_name, stats.st_uid, stats.st_gid, 0);
 910                         } else {
 911                                 utimensat(dirfd(dir_to), dent->d_name, NULL, 0);
 912                         }
 913                         udev_selinux_resetfscreatecon(udev);
 914                 } else if (S_ISLNK(stats.st_mode)) {
 915                         char target[UTIL_PATH_SIZE];
 916                         ssize_t len;
 917
 918                         len = readlinkat(dirfd(dir_from), dent->d_name, target, sizeof(target));
 919                         if (len <= 0 || len == (ssize_t)sizeof(target))
 920                                 continue;
 921                         target[len] = '\0';
 922                         udev_selinux_setfscreateconat(udev, dirfd(dir_to), dent->d_name, S_IFLNK);
 923                         if (symlinkat(target, dirfd(dir_to), dent->d_name) < 0 && errno == EEXIST)
 924                                 utimensat(dirfd(dir_to), dent->d_name, NULL, AT_SYMLINK_NOFOLLOW);
 925                         udev_selinux_resetfscreatecon(udev);
 926                 } else if (S_ISDIR(stats.st_mode)) {
 927                         DIR *dir2_from, *dir2_to;
 928
 929                         if (maxdepth == 0)
 930                                 continue;
 931
 932                         udev_selinux_setfscreateconat(udev, dirfd(dir_to), dent->d_name, S_IFDIR|0755);
 933                         mkdirat(dirfd(dir_to), dent->d_name, 0755);
 934                         udev_selinux_resetfscreatecon(udev);
 935
 936                         dir2_to = fdopendir(openat(dirfd(dir_to), dent->d_name, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC));
 937                         if (dir2_to == NULL)
 938                                 continue;
 939
 940                         dir2_from = fdopendir(openat(dirfd(dir_from), dent->d_name, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC));
 941                         if (dir2_from == NULL) {
 942                                 closedir(dir2_to);
 943                                 continue;
 944                         }
 945
 946                         copy_dev_dir(udev, dir2_from, dir2_to, maxdepth-1);
 947
 948                         closedir(dir2_to);
 949                         closedir(dir2_from);
 950                 }
 951         }
 952
 953         return 0;
 954 }
 955
 956 static void static_dev_create_links(struct udev *udev, DIR *dir)
 957 {
 958         struct stdlinks {
 959                 const char *link;
 960                 const char *target;
 961         };
 962         static const struct stdlinks stdlinks[] = {
 963                 { "core", "/proc/kcore" },
 964                 { "fd", "/proc/self/fd" },
 965                 { "stdin", "/proc/self/fd/0" },
 966                 { "stdout", "/proc/self/fd/1" },
 967                 { "stderr", "/proc/self/fd/2" },
 968         };
 969         unsigned int i;
 970
 971         for (i = 0; i < ARRAY_SIZE(stdlinks); i++) {
 972                 struct stat sb;
 973
 974                 if (stat(stdlinks[i].target, &sb) == 0) {
 975                         udev_selinux_setfscreateconat(udev, dirfd(dir), stdlinks[i].link, S_IFLNK);
 976                         if (symlinkat(stdlinks[i].target, dirfd(dir), stdlinks[i].link) < 0 && errno == EEXIST)
 977                                 utimensat(dirfd(dir), stdlinks[i].link, NULL, AT_SYMLINK_NOFOLLOW);
 978                         udev_selinux_resetfscreatecon(udev);
 979                 }
 980         }
 981 }
 982
 983 static void static_dev_create_from_devices(struct udev *udev, DIR *dir)
 984 {
 985         DIR *dir_from;
 986
 987         dir_from = opendir(LIBEXECDIR "/devices");
 988         if (dir_from == NULL)
 989                 return;
 990         copy_dev_dir(udev, dir_from, dir, 8);
 991         closedir(dir_from);
 992 }
 993
 994 static void static_dev_create(struct udev *udev)
 995 {
 996         DIR *dir;
 997
 998         dir = opendir(udev_get_dev_path(udev));
 999         if (dir == NULL)
1000                 return;
1001
1002         static_dev_create_links(udev, dir);
1003         static_dev_create_from_devices(udev, dir);
1004
1005         closedir(dir);
1006 }
1007
1008 static int mem_size_mb(void)
1009 {
1010         FILE *f;
1011         char buf[4096];
1012         long int memsize = -1;
1013
1014         f = fopen("/proc/meminfo", "r");
1015         if (f == NULL)
1016                 return -1;
1017
1018         while (fgets(buf, sizeof(buf), f) != NULL) {
1019                 long int value;
1020
1021                 if (sscanf(buf, "MemTotal: %ld kB", &value) == 1) {
1022                         memsize = value / 1024;
1023                         break;
1024                 }
1025         }
1026
1027         fclose(f);
1028         return memsize;
1029 }
1030
1031 static int convert_db(struct udev *udev)
1032 {
1033         char filename[UTIL_PATH_SIZE];
1034         FILE *f;
1035         struct udev_enumerate *udev_enumerate;
1036         struct udev_list_entry *list_entry;
1037
1038         /* current database */
1039         util_strscpyl(filename, sizeof(filename), udev_get_run_path(udev), "/data", NULL);
1040         if (access(filename, F_OK) >= 0)
1041                 return 0;
1042
1043         /* make sure we do not get here again */
1044         util_create_path(udev, filename);
1045         mkdir(filename, 0755);
1046
1047         /* old database */
1048         util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev), "/.udev/db", NULL);
1049         if (access(filename, F_OK) < 0)
1050                 return 0;
1051
1052         f = fopen("/dev/kmsg", "w");
1053         if (f != NULL) {
1054                 fprintf(f, "<30>udevd[%u]: converting old udev database\n", getpid());
1055                 fclose(f);
1056         }
1057
1058         udev_enumerate = udev_enumerate_new(udev);
1059         if (udev_enumerate == NULL)
1060                 return -1;
1061         udev_enumerate_scan_devices(udev_enumerate);
1062         udev_list_entry_foreach(list_entry, udev_enumerate_get_list_entry(udev_enumerate)) {
1063                 struct udev_device *device;
1064
1065                 device = udev_device_new_from_syspath(udev, udev_list_entry_get_name(list_entry));
1066                 if (device == NULL)
1067                         continue;
1068
1069                 /* try to find the old database for devices without a current one */
1070                 if (udev_device_read_db(device, NULL) < 0) {
1071                         bool have_db;
1072                         const char *id;
1073                         struct stat stats;
1074                         char devpath[UTIL_PATH_SIZE];
1075                         char from[UTIL_PATH_SIZE];
1076
1077                         have_db = false;
1078
1079                         /* find database in old location */
1080                         id = udev_device_get_id_filename(device);
1081                         util_strscpyl(from, sizeof(from), udev_get_dev_path(udev), "/.udev/db/", id, NULL);
1082                         if (lstat(from, &stats) == 0) {
1083                                 if (!have_db) {
1084                                         udev_device_read_db(device, from);
1085                                         have_db = true;
1086                                 }
1087                                 unlink(from);
1088                         }
1089
1090                         /* find old database with $subsys:$sysname name */
1091                         util_strscpyl(from, sizeof(from), udev_get_dev_path(udev),
1092                                      "/.udev/db/", udev_device_get_subsystem(device), ":",
1093                                      udev_device_get_sysname(device), NULL);
1094                         if (lstat(from, &stats) == 0) {
1095                                 if (!have_db) {
1096                                         udev_device_read_db(device, from);
1097                                         have_db = true;
1098                                 }
1099                                 unlink(from);
1100                         }
1101
1102                         /* find old database with the encoded devpath name */
1103                         util_path_encode(udev_device_get_devpath(device), devpath, sizeof(devpath));
1104                         util_strscpyl(from, sizeof(from), udev_get_dev_path(udev), "/.udev/db/", devpath, NULL);
1105                         if (lstat(from, &stats) == 0) {
1106                                 if (!have_db) {
1107                                         udev_device_read_db(device, from);
1108                                         have_db = true;
1109                                 }
1110                                 unlink(from);
1111                         }
1112
1113                         /* write out new database */
1114                         if (have_db)
1115                                 udev_device_update_db(device);
1116                 }
1117                 udev_device_unref(device);
1118         }
1119         udev_enumerate_unref(udev_enumerate);
1120         return 0;
1121 }
1122
1123 static int systemd_fds(struct udev *udev, int *rctrl, int *rnetlink)
1124 {
1125         int ctrl = -1, netlink = -1;
1126         int fd, n;
1127
1128         n = sd_listen_fds(true);
1129         if (n <= 0)
1130                 return -1;
1131
1132         for (fd = SD_LISTEN_FDS_START; fd < n + SD_LISTEN_FDS_START; fd++) {
1133                 if (sd_is_socket(fd, AF_LOCAL, SOCK_SEQPACKET, -1)) {
1134                         if (ctrl >= 0)
1135                                 return -1;
1136                         ctrl = fd;
1137                         continue;
1138                 }
1139
1140                 if (sd_is_socket(fd, AF_NETLINK, SOCK_RAW, -1)) {
1141                         if (netlink >= 0)
1142                                 return -1;
1143                         netlink = fd;
1144                         continue;
1145                 }
1146
1147                 return -1;
1148         }
1149
1150         if (ctrl < 0 || netlink < 0)
1151                 return -1;
1152
1153         info(udev, "ctrl=%i netlink=%i\n", ctrl, netlink);
1154         *rctrl = ctrl;
1155         *rnetlink = netlink;
1156         return 0;
1157 }
1158
1159 static bool check_rules_timestamp(struct udev *udev)
1160 {
1161         char **p;
1162         unsigned long long *stamp_usec;
1163         int i, n;
1164         bool changed = false;
1165
1166         n = udev_get_rules_path(udev, &p, &stamp_usec);
1167         for (i = 0; i < n; i++) {
1168                 struct stat stats;
1169
1170                 if (stat(p[i], &stats) < 0)
1171                         continue;
1172
1173                 if (stamp_usec[i] == ts_usec(&stats.st_mtim))
1174                         continue;
1175
1176                 /* first check */
1177                 if (stamp_usec[i] != 0) {
1178                         info(udev, "reload - timestamp of '%s' changed\n", p[i]);
1179                         changed = true;
1180                 }
1181
1182                 /* update timestamp */
1183                 stamp_usec[i] = ts_usec(&stats.st_mtim);
1184         }
1185
1186         return changed;
1187 }
1188
1189 int main(int argc, char *argv[])
1190 {
1191         struct udev *udev;
1192         FILE *f;
1193         sigset_t mask;
1194         int daemonize = false;
1195         int resolve_names = 1;
1196         static const struct option options[] = {
1197                 { "daemon", no_argument, NULL, 'd' },
1198                 { "debug", no_argument, NULL, 'D' },
1199                 { "children-max", required_argument, NULL, 'c' },
1200                 { "exec-delay", required_argument, NULL, 'e' },
1201                 { "resolve-names", required_argument, NULL, 'N' },
1202                 { "help", no_argument, NULL, 'h' },
1203                 { "version", no_argument, NULL, 'V' },
1204                 {}
1205         };
1206         int fd_ctrl = -1;
1207         int fd_netlink = -1;
1208         int fd_worker = -1;
1209         struct epoll_event ep_ctrl, ep_inotify, ep_signal, ep_netlink, ep_worker;
1210         struct udev_ctrl_connection *ctrl_conn = NULL;
1211         char **s;
1212         int rc = 1;
1213
1214         udev = udev_new();
1215         if (udev == NULL)
1216                 goto exit;
1217
1218         udev_log_init("udevd");
1219         udev_set_log_fn(udev, udev_main_log);
1220         info(udev, "version %s\n", VERSION);
1221         udev_selinux_init(udev);
1222
1223         for (;;) {
1224                 int option;
1225
1226                 option = getopt_long(argc, argv, "c:deDtN:hV", options, NULL);
1227                 if (option == -1)
1228                         break;
1229
1230                 switch (option) {
1231                 case 'd':
1232                         daemonize = true;
1233                         break;
1234                 case 'c':
1235                         children_max = strtoul(optarg, NULL, 0);
1236                         break;
1237                 case 'e':
1238                         exec_delay = strtoul(optarg, NULL, 0);
1239                         break;
1240                 case 'D':
1241                         debug = true;
1242                         if (udev_get_log_priority(udev) < LOG_INFO)
1243                                 udev_set_log_priority(udev, LOG_INFO);
1244                         break;
1245                 case 'N':
1246                         if (strcmp (optarg, "early") == 0) {
1247                                 resolve_names = 1;
1248                         } else if (strcmp (optarg, "late") == 0) {
1249                                 resolve_names = 0;
1250                         } else if (strcmp (optarg, "never") == 0) {
1251                                 resolve_names = -1;
1252                         } else {
1253                                 fprintf(stderr, "resolve-names must be early, late or never\n");
1254                                 err(udev, "resolve-names must be early, late or never\n");
1255                                 goto exit;
1256                         }
1257                         break;
1258                 case 'h':
1259                         printf("Usage: udevd OPTIONS\n"
1260                                "  --daemon\n"
1261                                "  --debug\n"
1262                                "  --children-max=<maximum number of workers>\n"
1263                                "  --exec-delay=<seconds to wait before executing RUN=>\n"
1264                                "  --resolve-names=early|late|never\n"
1265                                "  --version\n"
1266                                "  --help\n"
1267                                "\n");
1268                         goto exit;
1269                 case 'V':
1270                         printf("%s\n", VERSION);
1271                         goto exit;
1272                 default:
1273                         goto exit;
1274                 }
1275         }
1276
1277         /*
1278          * read the kernel commandline, in case we need to get into debug mode
1279          *   udev.log-priority=<level>              syslog priority
1280          *   udev.children-max=<number of workers>  events are fully serialized if set to 1
1281          *
1282          */
1283         f = fopen("/proc/cmdline", "r");
1284         if (f != NULL) {
1285                 char cmdline[4096];
1286
1287                 if (fgets(cmdline, sizeof(cmdline), f) != NULL) {
1288                         char *pos;
1289
1290                         pos = strstr(cmdline, "udev.log-priority=");
1291                         if (pos != NULL) {
1292                                 pos += strlen("udev.log-priority=");
1293                                 udev_set_log_priority(udev, util_log_priority(pos));
1294                         }
1295
1296                         pos = strstr(cmdline, "udev.children-max=");
1297                         if (pos != NULL) {
1298                                 pos += strlen("udev.children-max=");
1299                                 children_max = strtoul(pos, NULL, 0);
1300                         }
1301
1302                         pos = strstr(cmdline, "udev.exec-delay=");
1303                         if (pos != NULL) {
1304                                 pos += strlen("udev.exec-delay=");
1305                                 exec_delay = strtoul(pos, NULL, 0);
1306                         }
1307                 }
1308                 fclose(f);
1309         }
1310
1311         if (getuid() != 0) {
1312                 fprintf(stderr, "root privileges required\n");
1313                 err(udev, "root privileges required\n");
1314                 goto exit;
1315         }
1316
1317         /* set umask before creating any file/directory */
1318         chdir("/");
1319         umask(022);
1320
1321         /* /run/udev */
1322         mkdir(udev_get_run_path(udev), 0755);
1323
1324         /* create standard links, copy static nodes, create nodes from modules */
1325         static_dev_create(udev);
1326         static_dev_create_from_modules(udev);
1327
1328         /* before opening new files, make sure std{in,out,err} fds are in a sane state */
1329         if (daemonize) {
1330                 int fd;
1331
1332                 fd = open("/dev/null", O_RDWR);
1333                 if (fd >= 0) {
1334                         if (write(STDOUT_FILENO, 0, 0) < 0)
1335                                 dup2(fd, STDOUT_FILENO);
1336                         if (write(STDERR_FILENO, 0, 0) < 0)
1337                                 dup2(fd, STDERR_FILENO);
1338                         if (fd > STDERR_FILENO)
1339                                 close(fd);
1340                 } else {
1341                         fprintf(stderr, "cannot open /dev/null\n");
1342                         err(udev, "cannot open /dev/null\n");
1343                 }
1344         }
1345
1346         if (systemd_fds(udev, &fd_ctrl, &fd_netlink) >= 0) {
1347                 /* get control and netlink socket from from systemd */
1348                 udev_ctrl = udev_ctrl_new_from_fd(udev, fd_ctrl);
1349                 if (udev_ctrl == NULL) {
1350                         err(udev, "error taking over udev control socket");
1351                         rc = 1;
1352                         goto exit;
1353                 }
1354
1355                 monitor = udev_monitor_new_from_netlink_fd(udev, "kernel", fd_netlink);
1356                 if (monitor == NULL) {
1357                         err(udev, "error taking over netlink socket\n");
1358                         rc = 3;
1359                         goto exit;
1360                 }
1361         } else {
1362                 /* open control and netlink socket */
1363                 udev_ctrl = udev_ctrl_new(udev);
1364                 if (udev_ctrl == NULL) {
1365                         fprintf(stderr, "error initializing udev control socket");
1366                         err(udev, "error initializing udev control socket");
1367                         rc = 1;
1368                         goto exit;
1369                 }
1370                 fd_ctrl = udev_ctrl_get_fd(udev_ctrl);
1371
1372                 monitor = udev_monitor_new_from_netlink(udev, "kernel");
1373                 if (monitor == NULL) {
1374                         fprintf(stderr, "error initializing netlink socket\n");
1375                         err(udev, "error initializing netlink socket\n");
1376                         rc = 3;
1377                         goto exit;
1378                 }
1379                 fd_netlink = udev_monitor_get_fd(monitor);
1380         }
1381
1382         if (udev_monitor_enable_receiving(monitor) < 0) {
1383                 fprintf(stderr, "error binding netlink socket\n");
1384                 err(udev, "error binding netlink socket\n");
1385                 rc = 3;
1386                 goto exit;
1387         }
1388
1389         if (udev_ctrl_enable_receiving(udev_ctrl) < 0) {
1390                 fprintf(stderr, "error binding udev control socket\n");
1391                 err(udev, "error binding udev control socket\n");
1392                 rc = 1;
1393                 goto exit;
1394         }
1395
1396         udev_monitor_set_receive_buffer_size(monitor, 128*1024*1024);
1397
1398         /* create queue file before signalling 'ready', to make sure we block 'settle' */
1399         udev_queue_export = udev_queue_export_new(udev);
1400         if (udev_queue_export == NULL) {
1401                 err(udev, "error creating queue file\n");
1402                 goto exit;
1403         }
1404
1405         if (daemonize) {
1406                 pid_t pid;
1407                 int fd;
1408
1409                 pid = fork();
1410                 switch (pid) {
1411                 case 0:
1412                         break;
1413                 case -1:
1414                         err(udev, "fork of daemon failed: %m\n");
1415                         rc = 4;
1416                         goto exit;
1417                 default:
1418                         rc = EXIT_SUCCESS;
1419                         goto exit_daemonize;
1420                 }
1421
1422                 setsid();
1423
1424                 fd = open("/proc/self/oom_score_adj", O_RDWR);
1425                 if (fd < 0) {
1426                         /* Fallback to old interface */
1427                         fd = open("/proc/self/oom_adj", O_RDWR);
1428                         if (fd < 0) {
1429                                 err(udev, "error disabling OOM: %m\n");
1430                         } else {
1431                                 /* OOM_DISABLE == -17 */
1432                                 write(fd, "-17", 3);
1433                                 close(fd);
1434                         }
1435                 } else {
1436                         write(fd, "-1000", 5);
1437                         close(fd);
1438                 }
1439         } else {
1440                 sd_notify(1, "READY=1");
1441         }
1442
1443         f = fopen("/dev/kmsg", "w");
1444         if (f != NULL) {
1445                 fprintf(f, "<30>udevd[%u]: starting version " VERSION "\n", getpid());
1446                 fclose(f);
1447         }
1448
1449         if (!debug) {
1450                 int fd;
1451
1452                 fd = open("/dev/null", O_RDWR);
1453                 if (fd >= 0) {
1454                         dup2(fd, STDIN_FILENO);
1455                         dup2(fd, STDOUT_FILENO);
1456                         dup2(fd, STDERR_FILENO);
1457                         close(fd);
1458                 }
1459         }
1460
1461         fd_inotify = udev_watch_init(udev);
1462         if (fd_inotify < 0) {
1463                 fprintf(stderr, "error initializing inotify\n");
1464                 err(udev, "error initializing inotify\n");
1465                 rc = 4;
1466                 goto exit;
1467         }
1468         udev_watch_restore(udev);
1469
1470         /* block and listen to all signals on signalfd */
1471         sigfillset(&mask);
1472         sigprocmask(SIG_SETMASK, &mask, &sigmask_orig);
1473         fd_signal = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC);
1474         if (fd_signal < 0) {
1475                 fprintf(stderr, "error creating signalfd\n");
1476                 err(udev, "error creating signalfd\n");
1477                 rc = 5;
1478                 goto exit;
1479         }
1480
1481         /* unnamed socket from workers to the main daemon */
1482         if (socketpair(AF_LOCAL, SOCK_DGRAM|SOCK_CLOEXEC, 0, worker_watch) < 0) {
1483                 fprintf(stderr, "error creating socketpair\n");
1484                 err(udev, "error creating socketpair\n");
1485                 rc = 6;
1486                 goto exit;
1487         }
1488         fd_worker = worker_watch[READ_END];
1489
1490         udev_builtin_init(udev);
1491
1492         rules = udev_rules_new(udev, resolve_names);
1493         if (rules == NULL) {
1494                 err(udev, "error reading rules\n");
1495                 goto exit;
1496         }
1497
1498         memset(&ep_ctrl, 0, sizeof(struct epoll_event));
1499         ep_ctrl.events = EPOLLIN;
1500         ep_ctrl.data.fd = fd_ctrl;
1501
1502         memset(&ep_inotify, 0, sizeof(struct epoll_event));
1503         ep_inotify.events = EPOLLIN;
1504         ep_inotify.data.fd = fd_inotify;
1505
1506         memset(&ep_signal, 0, sizeof(struct epoll_event));
1507         ep_signal.events = EPOLLIN;
1508         ep_signal.data.fd = fd_signal;
1509
1510         memset(&ep_netlink, 0, sizeof(struct epoll_event));
1511         ep_netlink.events = EPOLLIN;
1512         ep_netlink.data.fd = fd_netlink;
1513
1514         memset(&ep_worker, 0, sizeof(struct epoll_event));
1515         ep_worker.events = EPOLLIN;
1516         ep_worker.data.fd = fd_worker;
1517
1518         fd_ep = epoll_create1(EPOLL_CLOEXEC);
1519         if (fd_ep < 0) {
1520                 err(udev, "error creating epoll fd: %m\n");
1521                 goto exit;
1522         }
1523         if (epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_ctrl, &ep_ctrl) < 0 ||
1524             epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_inotify, &ep_inotify) < 0 ||
1525             epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_signal, &ep_signal) < 0 ||
1526             epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_netlink, &ep_netlink) < 0 ||
1527             epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_worker, &ep_worker) < 0) {
1528                 err(udev, "fail to add fds to epoll: %m\n");
1529                 goto exit;
1530         }
1531
1532         /* if needed, convert old database from earlier udev version */
1533         convert_db(udev);
1534
1535         if (children_max <= 0) {
1536                 int memsize = mem_size_mb();
1537
1538                 /* set value depending on the amount of RAM */
1539                 if (memsize > 0)
1540                         children_max = 128 + (memsize / 8);
1541                 else
1542                         children_max = 128;
1543         }
1544         info(udev, "set children_max to %u\n", children_max);
1545
1546         udev_rules_apply_static_dev_perms(rules);
1547
1548         udev_list_node_init(&event_list);
1549         udev_list_node_init(&worker_list);
1550
1551         for (;;) {
1552                 static unsigned long long last_usec;
1553                 struct epoll_event ev[8];
1554                 int fdcount;
1555                 int timeout;
1556                 bool is_worker, is_signal, is_inotify, is_netlink, is_ctrl;
1557                 int i;
1558
1559                 if (udev_exit) {
1560                         /* close sources of new events and discard buffered events */
1561                         if (fd_ctrl >= 0) {
1562                                 epoll_ctl(fd_ep, EPOLL_CTL_DEL, fd_ctrl, NULL);
1563                                 fd_ctrl = -1;
1564                         }
1565                         if (monitor != NULL) {
1566                                 epoll_ctl(fd_ep, EPOLL_CTL_DEL, fd_netlink, NULL);
1567                                 udev_monitor_unref(monitor);
1568                                 monitor = NULL;
1569                         }
1570                         if (fd_inotify >= 0) {
1571                                 epoll_ctl(fd_ep, EPOLL_CTL_DEL, fd_inotify, NULL);
1572                                 close(fd_inotify);
1573                                 fd_inotify = -1;
1574                         }
1575
1576                         /* discard queued events and kill workers */
1577                         event_queue_cleanup(udev, EVENT_QUEUED);
1578                         worker_kill(udev, 0);
1579
1580                         /* exit after all has cleaned up */
1581                         if (udev_list_node_is_empty(&event_list) && udev_list_node_is_empty(&worker_list))
1582                                 break;
1583
1584                         /* timeout at exit for workers to finish */
1585                         timeout = 60 * 1000;
1586                 } else if (udev_list_node_is_empty(&event_list) && children > 2) {
1587                         /* set timeout to kill idle workers */
1588                         timeout = 3 * 1000;
1589                 } else {
1590                         timeout = -1;
1591                 }
1592                 fdcount = epoll_wait(fd_ep, ev, ARRAY_SIZE(ev), timeout);
1593                 if (fdcount < 0)
1594                         continue;
1595
1596                 if (fdcount == 0) {
1597                         if (udev_exit) {
1598                                 info(udev, "timeout, giving up waiting for workers to finish\n");
1599                                 break;
1600                         }
1601
1602                         /* timeout - kill idle workers */
1603                         worker_kill(udev, 2);
1604                 }
1605
1606                 is_worker = is_signal = is_inotify = is_netlink = is_ctrl = false;
1607                 for (i = 0; i < fdcount; i++) {
1608                         if (ev[i].data.fd == fd_worker && ev[i].events & EPOLLIN)
1609                                 is_worker = true;
1610                         else if (ev[i].data.fd == fd_netlink && ev[i].events & EPOLLIN)
1611                                 is_netlink = true;
1612                         else if (ev[i].data.fd == fd_signal && ev[i].events & EPOLLIN)
1613                                 is_signal = true;
1614                         else if (ev[i].data.fd == fd_inotify && ev[i].events & EPOLLIN)
1615                                 is_inotify = true;
1616                         else if (ev[i].data.fd == fd_ctrl && ev[i].events & EPOLLIN)
1617                                 is_ctrl = true;
1618                 }
1619
1620                 /* check for changed config, every 3 seconds at most */
1621                 if ((now_usec() - last_usec) > 3 * 1000 * 1000) {
1622                         if (check_rules_timestamp(udev))
1623                                 reload = true;
1624                         if (udev_builtin_validate(udev))
1625                                 reload = true;
1626
1627                         last_usec = now_usec();
1628                 }
1629
1630                 /* reload requested, HUP signal received, rules changed, builtin changed */
1631                 if (reload) {
1632                         worker_kill(udev, 0);
1633                         rules = udev_rules_unref(rules);
1634                         udev_builtin_exit(udev);
1635                         reload = 0;
1636                 }
1637
1638                 /* event has finished */
1639                 if (is_worker)
1640                         worker_returned(fd_worker);
1641
1642                 if (is_netlink) {
1643                         struct udev_device *dev;
1644
1645                         dev = udev_monitor_receive_device(monitor);
1646                         if (dev != NULL) {
1647                                 udev_device_set_usec_initialized(dev, now_usec());
1648                                 if (event_queue_insert(dev) < 0)
1649                                         udev_device_unref(dev);
1650                         }
1651                 }
1652
1653                 /* start new events */
1654                 if (!udev_list_node_is_empty(&event_list) && !udev_exit && !stop_exec_queue) {
1655                         if (rules == NULL)
1656                                 rules = udev_rules_new(udev, resolve_names);
1657                         if (rules != NULL)
1658                                 event_queue_start(udev);
1659                 }
1660
1661                 if (is_signal) {
1662                         struct signalfd_siginfo fdsi;
1663                         ssize_t size;
1664
1665                         size = read(fd_signal, &fdsi, sizeof(struct signalfd_siginfo));
1666                         if (size == sizeof(struct signalfd_siginfo))
1667                                 handle_signal(udev, fdsi.ssi_signo);
1668                 }
1669
1670                 /* we are shutting down, the events below are not handled anymore */
1671                 if (udev_exit)
1672                         continue;
1673
1674                 /* device node watch */
1675                 if (is_inotify)
1676                         handle_inotify(udev);
1677
1678                 /*
1679                  * This needs to be after the inotify handling, to make sure,
1680                  * that the ping is send back after the possibly generated
1681                  * "change" events by the inotify device node watch.
1682                  *
1683                  * A single time we may receive a client connection which we need to
1684                  * keep open to block the client. It will be closed right before we
1685                  * exit.
1686                  */
1687                 if (is_ctrl)
1688                         ctrl_conn = handle_ctrl_msg(udev_ctrl);
1689         }
1690
1691         rc = EXIT_SUCCESS;
1692 exit:
1693         udev_queue_export_cleanup(udev_queue_export);
1694         udev_ctrl_cleanup(udev_ctrl);
1695 exit_daemonize:
1696         if (fd_ep >= 0)
1697                 close(fd_ep);
1698         worker_list_cleanup(udev);
1699         event_queue_cleanup(udev, EVENT_UNDEF);
1700         udev_rules_unref(rules);
1701         udev_builtin_exit(udev);
1702         if (fd_signal >= 0)
1703                 close(fd_signal);
1704         if (worker_watch[READ_END] >= 0)
1705                 close(worker_watch[READ_END]);
1706         if (worker_watch[WRITE_END] >= 0)
1707                 close(worker_watch[WRITE_END]);
1708         udev_monitor_unref(monitor);
1709         udev_queue_export_unref(udev_queue_export);
1710         udev_ctrl_connection_unref(ctrl_conn);
1711         udev_ctrl_unref(udev_ctrl);
1712         udev_selinux_exit(udev);
1713         udev_unref(udev);
1714         udev_log_close();
1715         return rc;
1716 }