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 static void log_fn(struct udev *udev, int priority,
  53                    const char *file, int line, const char *fn,
  54                    const char *format, va_list args)
  55 {
  56         if (debug) {
  57                 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_config;
  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                 /* mark as failed, if "add" event returns non-zero */
 159                 if (event->exitcode != 0 && strcmp(udev_device_get_action(event->dev), "remove") != 0)
 160                         udev_queue_export_device_failed(udev_queue_export, event->dev);
 161                 else
 162                         udev_queue_export_device_finished(udev_queue_export, event->dev);
 163                 info(event->udev, "seq %llu done with %i\n", udev_device_get_seqnum(event->dev), event->exitcode);
 164         }
 165         udev_device_unref(event->dev);
 166         free(event);
 167 }
 168
 169 static struct worker *worker_ref(struct worker *worker)
 170 {
 171         worker->refcount++;
 172         return worker;
 173 }
 174
 175 static void worker_cleanup(struct worker *worker)
 176 {
 177         udev_list_node_remove(&worker->node);
 178         udev_monitor_unref(worker->monitor);
 179         children--;
 180         free(worker);
 181 }
 182
 183 static void worker_unref(struct worker *worker)
 184 {
 185         worker->refcount--;
 186         if (worker->refcount > 0)
 187                 return;
 188         info(worker->udev, "worker [%u] cleaned up\n", worker->pid);
 189         worker_cleanup(worker);
 190 }
 191
 192 static void worker_list_cleanup(struct udev *udev)
 193 {
 194         struct udev_list_node *loop, *tmp;
 195
 196         udev_list_node_foreach_safe(loop, tmp, &worker_list) {
 197                 struct worker *worker = node_to_worker(loop);
 198
 199                 worker_cleanup(worker);
 200         }
 201 }
 202
 203 static void worker_new(struct event *event)
 204 {
 205         struct udev *udev = event->udev;
 206         struct worker *worker;
 207         struct udev_monitor *worker_monitor;
 208         pid_t pid;
 209
 210         /* listen for new events */
 211         worker_monitor = udev_monitor_new_from_netlink(udev, NULL);
 212         if (worker_monitor == NULL)
 213                 return;
 214         /* allow the main daemon netlink address to send devices to the worker */
 215         udev_monitor_allow_unicast_sender(worker_monitor, monitor);
 216         udev_monitor_enable_receiving(worker_monitor);
 217
 218         worker = calloc(1, sizeof(struct worker));
 219         if (worker == NULL) {
 220                 udev_monitor_unref(worker_monitor);
 221                 return;
 222         }
 223         /* worker + event reference */
 224         worker->refcount = 2;
 225         worker->udev = udev;
 226
 227         pid = fork();
 228         switch (pid) {
 229         case 0: {
 230                 struct udev_device *dev = NULL;
 231                 int fd_monitor;
 232                 struct epoll_event ep_signal, ep_monitor;
 233                 sigset_t mask;
 234                 int rc = EXIT_SUCCESS;
 235
 236                 /* move initial device from queue */
 237                 dev = event->dev;
 238                 event->dev = NULL;
 239
 240                 free(worker);
 241                 worker_list_cleanup(udev);
 242                 event_queue_cleanup(udev, EVENT_UNDEF);
 243                 udev_queue_export_unref(udev_queue_export);
 244                 udev_monitor_unref(monitor);
 245                 udev_ctrl_unref(udev_ctrl);
 246                 close(fd_signal);
 247                 close(fd_ep);
 248                 close(worker_watch[READ_END]);
 249
 250                 sigfillset(&mask);
 251                 fd_signal = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC);
 252                 if (fd_signal < 0) {
 253                         err(udev, "error creating signalfd %m\n");
 254                         rc = 2;
 255                         goto out;
 256                 }
 257
 258                 fd_ep = epoll_create1(EPOLL_CLOEXEC);
 259                 if (fd_ep < 0) {
 260                         err(udev, "error creating epoll fd: %m\n");
 261                         rc = 3;
 262                         goto out;
 263                 }
 264
 265                 memset(&ep_signal, 0, sizeof(struct epoll_event));
 266                 ep_signal.events = EPOLLIN;
 267                 ep_signal.data.fd = fd_signal;
 268
 269                 fd_monitor = udev_monitor_get_fd(worker_monitor);
 270                 memset(&ep_monitor, 0, sizeof(struct epoll_event));
 271                 ep_monitor.events = EPOLLIN;
 272                 ep_monitor.data.fd = fd_monitor;
 273
 274                 if (epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_signal, &ep_signal) < 0 ||
 275                     epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_monitor, &ep_monitor) < 0) {
 276                         err(udev, "fail to add fds to epoll: %m\n");
 277                         rc = 4;
 278                         goto out;
 279                 }
 280
 281                 /* request TERM signal if parent exits */
 282                 prctl(PR_SET_PDEATHSIG, SIGTERM);
 283
 284                 for (;;) {
 285                         struct udev_event *udev_event;
 286                         struct worker_message msg;
 287                         int failed = 0;
 288                         int err;
 289
 290                         info(udev, "seq %llu running\n", udev_device_get_seqnum(dev));
 291                         udev_event = udev_event_new(dev);
 292                         if (udev_event == NULL) {
 293                                 rc = 5;
 294                                 goto out;
 295                         }
 296
 297                         /* needed for SIGCHLD/SIGTERM in spawn() */
 298                         udev_event->fd_signal = fd_signal;
 299
 300                         if (exec_delay > 0)
 301                                 udev_event->exec_delay = exec_delay;
 302
 303                         /* apply rules, create node, symlinks */
 304                         err = udev_event_execute_rules(udev_event, rules, &sigmask_orig);
 305
 306                         if (err == 0)
 307                                 failed = udev_event_execute_run(udev_event, &sigmask_orig);
 308
 309                         /* apply/restore inotify watch */
 310                         if (err == 0 && udev_event->inotify_watch) {
 311                                 udev_watch_begin(udev, dev);
 312                                 udev_device_update_db(dev);
 313                         }
 314
 315                         /* send processed event back to libudev listeners */
 316                         udev_monitor_send_device(worker_monitor, NULL, dev);
 317
 318                         /* send udevd the result of the event execution */
 319                         memset(&msg, 0, sizeof(struct worker_message));
 320                         if (err != 0)
 321                                 msg.exitcode = err;
 322                         else if (failed != 0)
 323                                 msg.exitcode = failed;
 324                         msg.pid = getpid();
 325                         send(worker_watch[WRITE_END], &msg, sizeof(struct worker_message), 0);
 326
 327                         info(udev, "seq %llu processed with %i\n", udev_device_get_seqnum(dev), err);
 328
 329                         udev_device_unref(dev);
 330                         dev = NULL;
 331
 332                         if (udev_event->sigterm) {
 333                                 udev_event_unref(udev_event);
 334                                 goto out;
 335                         }
 336
 337                         udev_event_unref(udev_event);
 338
 339                         /* wait for more device messages from main udevd, or term signal */
 340                         while (dev == NULL) {
 341                                 struct epoll_event ev[4];
 342                                 int fdcount;
 343                                 int i;
 344
 345                                 fdcount = epoll_wait(fd_ep, ev, ARRAY_SIZE(ev), -1);
 346                                 if (fdcount < 0) {
 347                                         if (errno == EINTR)
 348                                                 continue;
 349                                         err = -errno;
 350                                         err(udev, "failed to poll: %m\n");
 351                                         goto out;
 352                                 }
 353
 354                                 for (i = 0; i < fdcount; i++) {
 355                                         if (ev[i].data.fd == fd_monitor && ev[i].events & EPOLLIN) {
 356                                                 dev = udev_monitor_receive_device(worker_monitor);
 357                                         } else if (ev[i].data.fd == fd_signal && ev[i].events & EPOLLIN) {
 358                                                 struct signalfd_siginfo fdsi;
 359                                                 ssize_t size;
 360
 361                                                 size = read(fd_signal, &fdsi, sizeof(struct signalfd_siginfo));
 362                                                 if (size != sizeof(struct signalfd_siginfo))
 363                                                         continue;
 364                                                 switch (fdsi.ssi_signo) {
 365                                                 case SIGTERM:
 366                                                         goto out;
 367                                                 }
 368                                         }
 369                                 }
 370                         }
 371                 }
 372 out:
 373                 udev_device_unref(dev);
 374                 if (fd_signal >= 0)
 375                         close(fd_signal);
 376                 if (fd_ep >= 0)
 377                         close(fd_ep);
 378                 close(fd_inotify);
 379                 close(worker_watch[WRITE_END]);
 380                 udev_rules_unref(rules);
 381                 udev_monitor_unref(worker_monitor);
 382                 udev_unref(udev);
 383                 udev_log_close();
 384                 exit(rc);
 385         }
 386         case -1:
 387                 udev_monitor_unref(worker_monitor);
 388                 event->state = EVENT_QUEUED;
 389                 free(worker);
 390                 err(udev, "fork of child failed: %m\n");
 391                 break;
 392         default:
 393                 /* close monitor, but keep address around */
 394                 udev_monitor_disconnect(worker_monitor);
 395                 worker->monitor = worker_monitor;
 396                 worker->pid = pid;
 397                 worker->state = WORKER_RUNNING;
 398                 worker->event = event;
 399                 event->state = EVENT_RUNNING;
 400                 udev_list_node_append(&worker->node, &worker_list);
 401                 children++;
 402                 info(udev, "seq %llu forked new worker [%u]\n", udev_device_get_seqnum(event->dev), pid);
 403                 break;
 404         }
 405 }
 406
 407 static void event_run(struct event *event, bool force)
 408 {
 409         struct udev_list_node *loop;
 410
 411         udev_list_node_foreach(loop, &worker_list) {
 412                 struct worker *worker = node_to_worker(loop);
 413                 ssize_t count;
 414
 415                 if (worker->state != WORKER_IDLE)
 416                         continue;
 417
 418                 count = udev_monitor_send_device(monitor, worker->monitor, event->dev);
 419                 if (count < 0) {
 420                         err(event->udev, "worker [%u] did not accept message %zi (%m), kill it\n", worker->pid, count);
 421                         kill(worker->pid, SIGKILL);
 422                         worker->state = WORKER_KILLED;
 423                         continue;
 424                 }
 425                 worker_ref(worker);
 426                 worker->event = event;
 427                 worker->state = WORKER_RUNNING;
 428                 event->state = EVENT_RUNNING;
 429                 return;
 430         }
 431
 432         if (!force && children >= children_max) {
 433                 if (children_max > 1)
 434                         info(event->udev, "maximum number (%i) of children reached\n", children);
 435                 return;
 436         }
 437
 438         /* start new worker and pass initial device */
 439         worker_new(event);
 440 }
 441
 442 static int event_queue_insert(struct udev_device *dev)
 443 {
 444         struct event *event;
 445
 446         event = calloc(1, sizeof(struct event));
 447         if (event == NULL)
 448                 return -1;
 449
 450         event->udev = udev_device_get_udev(dev);
 451         event->dev = dev;
 452         event->seqnum = udev_device_get_seqnum(dev);
 453         event->devpath = udev_device_get_devpath(dev);
 454         event->devpath_len = strlen(event->devpath);
 455         event->devpath_old = udev_device_get_devpath_old(dev);
 456         event->devnum = udev_device_get_devnum(dev);
 457         event->is_block = (strcmp("block", udev_device_get_subsystem(dev)) == 0);
 458         event->ifindex = udev_device_get_ifindex(dev);
 459
 460         udev_queue_export_device_queued(udev_queue_export, dev);
 461         info(event->udev, "seq %llu queued, '%s' '%s'\n", udev_device_get_seqnum(dev),
 462              udev_device_get_action(dev), udev_device_get_subsystem(dev));
 463
 464         event->state = EVENT_QUEUED;
 465         udev_list_node_append(&event->node, &event_list);
 466
 467         /* run all events with a timeout set immediately */
 468         if (udev_device_get_timeout(dev) > 0) {
 469                 event_run(event, true);
 470                 return 0;
 471         }
 472
 473         return 0;
 474 }
 475
 476 static void worker_kill(struct udev *udev, int retain)
 477 {
 478         struct udev_list_node *loop;
 479         int max;
 480
 481         if (children <= retain)
 482                 return;
 483
 484         max = children - retain;
 485
 486         udev_list_node_foreach(loop, &worker_list) {
 487                 struct worker *worker = node_to_worker(loop);
 488
 489                 if (max-- <= 0)
 490                         break;
 491
 492                 if (worker->state == WORKER_KILLED)
 493                         continue;
 494
 495                 worker->state = WORKER_KILLED;
 496                 kill(worker->pid, SIGTERM);
 497         }
 498 }
 499
 500 /* lookup event for identical, parent, child device */
 501 static bool is_devpath_busy(struct event *event)
 502 {
 503         struct udev_list_node *loop;
 504         size_t common;
 505
 506         /* check if queue contains events we depend on */
 507         udev_list_node_foreach(loop, &event_list) {
 508                 struct event *loop_event = node_to_event(loop);
 509
 510                 /* we already found a later event, earlier can not block us, no need to check again */
 511                 if (loop_event->seqnum < event->delaying_seqnum)
 512                         continue;
 513
 514                 /* event we checked earlier still exists, no need to check again */
 515                 if (loop_event->seqnum == event->delaying_seqnum)
 516                         return true;
 517
 518                 /* found ourself, no later event can block us */
 519                 if (loop_event->seqnum >= event->seqnum)
 520                         break;
 521
 522                 /* check major/minor */
 523                 if (major(event->devnum) != 0 && event->devnum == loop_event->devnum && event->is_block == loop_event->is_block)
 524                         return true;
 525
 526                 /* check network device ifindex */
 527                 if (event->ifindex != 0 && event->ifindex == loop_event->ifindex)
 528                         return true;
 529
 530                 /* check our old name */
 531                 if (event->devpath_old != NULL && strcmp(loop_event->devpath, event->devpath_old) == 0) {
 532                         event->delaying_seqnum = loop_event->seqnum;
 533                         return true;
 534                 }
 535
 536                 /* compare devpath */
 537                 common = MIN(loop_event->devpath_len, event->devpath_len);
 538
 539                 /* one devpath is contained in the other? */
 540                 if (memcmp(loop_event->devpath, event->devpath, common) != 0)
 541                         continue;
 542
 543                 /* identical device event found */
 544                 if (loop_event->devpath_len == event->devpath_len) {
 545                         /* devices names might have changed/swapped in the meantime */
 546                         if (major(event->devnum) != 0 && (event->devnum != loop_event->devnum || event->is_block != loop_event->is_block))
 547                                 continue;
 548                         if (event->ifindex != 0 && event->ifindex != loop_event->ifindex)
 549                                 continue;
 550                         event->delaying_seqnum = loop_event->seqnum;
 551                         return true;
 552                 }
 553
 554                 /* parent device event found */
 555                 if (event->devpath[common] == '/') {
 556                         event->delaying_seqnum = loop_event->seqnum;
 557                         return true;
 558                 }
 559
 560                 /* child device event found */
 561                 if (loop_event->devpath[common] == '/') {
 562                         event->delaying_seqnum = loop_event->seqnum;
 563                         return true;
 564                 }
 565
 566                 /* no matching device */
 567                 continue;
 568         }
 569
 570         return false;
 571 }
 572
 573 static void event_queue_start(struct udev *udev)
 574 {
 575         struct udev_list_node *loop;
 576
 577         udev_list_node_foreach(loop, &event_list) {
 578                 struct event *event = node_to_event(loop);
 579
 580                 if (event->state != EVENT_QUEUED)
 581                         continue;
 582
 583                 /* do not start event if parent or child event is still running */
 584                 if (is_devpath_busy(event)) {
 585                         dbg(udev, "delay seq %llu (%s)\n", event->seqnum, event->devpath);
 586                         continue;
 587                 }
 588
 589                 event_run(event, false);
 590         }
 591 }
 592
 593 static void event_queue_cleanup(struct udev *udev, enum event_state match_type)
 594 {
 595         struct udev_list_node *loop, *tmp;
 596
 597         udev_list_node_foreach_safe(loop, tmp, &event_list) {
 598                 struct event *event = node_to_event(loop);
 599
 600                 if (match_type != EVENT_UNDEF && match_type != event->state)
 601                         continue;
 602
 603                 event_queue_delete(event, false);
 604         }
 605 }
 606
 607 static void worker_returned(int fd_worker)
 608 {
 609         for (;;) {
 610                 struct worker_message msg;
 611                 ssize_t size;
 612                 struct udev_list_node *loop;
 613
 614                 size = recv(fd_worker, &msg, sizeof(struct worker_message), MSG_DONTWAIT);
 615                 if (size != sizeof(struct worker_message))
 616                         break;
 617
 618                 /* lookup worker who sent the signal */
 619                 udev_list_node_foreach(loop, &worker_list) {
 620                         struct worker *worker = node_to_worker(loop);
 621
 622                         if (worker->pid != msg.pid)
 623                                 continue;
 624
 625                         /* worker returned */
 626                         worker->event->exitcode = msg.exitcode;
 627                         event_queue_delete(worker->event, true);
 628                         worker->event = NULL;
 629                         if (worker->state != WORKER_KILLED)
 630                                 worker->state = WORKER_IDLE;
 631                         worker_unref(worker);
 632                         break;
 633                 }
 634         }
 635 }
 636
 637 /* receive the udevd message from userspace */
 638 static struct udev_ctrl_connection *handle_ctrl_msg(struct udev_ctrl *uctrl)
 639 {
 640         struct udev *udev = udev_ctrl_get_udev(uctrl);
 641         struct udev_ctrl_connection *ctrl_conn;
 642         struct udev_ctrl_msg *ctrl_msg = NULL;
 643         const char *str;
 644         int i;
 645
 646         ctrl_conn = udev_ctrl_get_connection(uctrl);
 647         if (ctrl_conn == NULL)
 648                 goto out;
 649
 650         ctrl_msg = udev_ctrl_receive_msg(ctrl_conn);
 651         if (ctrl_msg == NULL)
 652                 goto out;
 653
 654         i = udev_ctrl_get_set_log_level(ctrl_msg);
 655         if (i >= 0) {
 656                 info(udev, "udevd message (SET_LOG_PRIORITY) received, log_priority=%i\n", i);
 657                 udev_set_log_priority(udev, i);
 658                 worker_kill(udev, 0);
 659         }
 660
 661         if (udev_ctrl_get_stop_exec_queue(ctrl_msg) > 0) {
 662                 info(udev, "udevd message (STOP_EXEC_QUEUE) received\n");
 663                 stop_exec_queue = true;
 664         }
 665
 666         if (udev_ctrl_get_start_exec_queue(ctrl_msg) > 0) {
 667                 info(udev, "udevd message (START_EXEC_QUEUE) received\n");
 668                 stop_exec_queue = false;
 669         }
 670
 671         if (udev_ctrl_get_reload_rules(ctrl_msg) > 0) {
 672                 info(udev, "udevd message (RELOAD_RULES) received\n");
 673                 reload_config = true;
 674         }
 675
 676         str = udev_ctrl_get_set_env(ctrl_msg);
 677         if (str != NULL) {
 678                 char *key;
 679
 680                 key = strdup(str);
 681                 if (key != NULL) {
 682                         char *val;
 683
 684                         val = strchr(key, '=');
 685                         if (val != NULL) {
 686                                 val[0] = '\0';
 687                                 val = &val[1];
 688                                 if (val[0] == '\0') {
 689                                         info(udev, "udevd message (ENV) received, unset '%s'\n", key);
 690                                         udev_add_property(udev, key, NULL);
 691                                 } else {
 692                                         info(udev, "udevd message (ENV) received, set '%s=%s'\n", key, val);
 693                                         udev_add_property(udev, key, val);
 694                                 }
 695                         } else {
 696                                 err(udev, "wrong key format '%s'\n", key);
 697                         }
 698                         free(key);
 699                 }
 700                 worker_kill(udev, 0);
 701         }
 702
 703         i = udev_ctrl_get_set_children_max(ctrl_msg);
 704         if (i >= 0) {
 705                 info(udev, "udevd message (SET_MAX_CHILDREN) received, children_max=%i\n", i);
 706                 children_max = i;
 707         }
 708
 709         if (udev_ctrl_get_ping(ctrl_msg) > 0)
 710                 info(udev, "udevd message (SYNC) received\n");
 711
 712         if (udev_ctrl_get_exit(ctrl_msg) > 0) {
 713                 info(udev, "udevd message (EXIT) received\n");
 714                 udev_exit = true;
 715                 /* keep reference to block the client until we exit */
 716                 udev_ctrl_connection_ref(ctrl_conn);
 717         }
 718 out:
 719         udev_ctrl_msg_unref(ctrl_msg);
 720         return udev_ctrl_connection_unref(ctrl_conn);
 721 }
 722
 723 /* read inotify messages */
 724 static int handle_inotify(struct udev *udev)
 725 {
 726         int nbytes, pos;
 727         char *buf;
 728         struct inotify_event *ev;
 729
 730         if ((ioctl(fd_inotify, FIONREAD, &nbytes) < 0) || (nbytes <= 0))
 731                 return 0;
 732
 733         buf = malloc(nbytes);
 734         if (buf == NULL) {
 735                 err(udev, "error getting buffer for inotify\n");
 736                 return -1;
 737         }
 738
 739         nbytes = read(fd_inotify, buf, nbytes);
 740
 741         for (pos = 0; pos < nbytes; pos += sizeof(struct inotify_event) + ev->len) {
 742                 struct udev_device *dev;
 743
 744                 ev = (struct inotify_event *)(buf + pos);
 745                 if (ev->len) {
 746                         const char *s;
 747
 748                         info(udev, "inotify event: %x for %s\n", ev->mask, ev->name);
 749                         s = strstr(ev->name, ".rules");
 750                         if (s == NULL)
 751                                 continue;
 752                         if (strlen(s) != strlen(".rules"))
 753                                 continue;
 754                         reload_config = true;
 755                         continue;
 756                 }
 757
 758                 dev = udev_watch_lookup(udev, ev->wd);
 759                 if (dev != NULL) {
 760                         info(udev, "inotify event: %x for %s\n", ev->mask, udev_device_get_devnode(dev));
 761                         if (ev->mask & IN_CLOSE_WRITE) {
 762                                 char filename[UTIL_PATH_SIZE];
 763                                 int fd;
 764
 765                                 info(udev, "device %s closed, synthesising 'change'\n", udev_device_get_devnode(dev));
 766                                 util_strscpyl(filename, sizeof(filename), udev_device_get_syspath(dev), "/uevent", NULL);
 767                                 fd = open(filename, O_WRONLY);
 768                                 if (fd >= 0) {
 769                                         if (write(fd, "change", 6) < 0)
 770                                                 info(udev, "error writing uevent: %m\n");
 771                                         close(fd);
 772                                 }
 773                         }
 774                         if (ev->mask & IN_IGNORED)
 775                                 udev_watch_end(udev, dev);
 776
 777                         udev_device_unref(dev);
 778                 }
 779
 780         }
 781
 782         free(buf);
 783         return 0;
 784 }
 785
 786 static void handle_signal(struct udev *udev, int signo)
 787 {
 788         switch (signo) {
 789         case SIGINT:
 790         case SIGTERM:
 791                 udev_exit = true;
 792                 break;
 793         case SIGCHLD:
 794                 for (;;) {
 795                         pid_t pid;
 796                         int status;
 797                         struct udev_list_node *loop, *tmp;
 798
 799                         pid = waitpid(-1, &status, WNOHANG);
 800                         if (pid <= 0)
 801                                 break;
 802
 803                         udev_list_node_foreach_safe(loop, tmp, &worker_list) {
 804                                 struct worker *worker = node_to_worker(loop);
 805
 806                                 if (worker->pid != pid)
 807                                         continue;
 808                                 info(udev, "worker [%u] exit\n", pid);
 809
 810                                 if (WIFEXITED(status)) {
 811                                         if (WEXITSTATUS(status) != 0)
 812                                                 err(udev, "worker [%u] exit with return code %i\n", pid, WEXITSTATUS(status));
 813                                 } else if (WIFSIGNALED(status)) {
 814                                         err(udev, "worker [%u] terminated by signal %i (%s)\n",
 815                                             pid, WTERMSIG(status), strsignal(WTERMSIG(status)));
 816                                 } else if (WIFSTOPPED(status)) {
 817                                         err(udev, "worker [%u] stopped\n", pid);
 818                                 } else if (WIFCONTINUED(status)) {
 819                                         err(udev, "worker [%u] continued\n", pid);
 820                                 } else {
 821                                         err(udev, "worker [%u] exit with status 0x%04x\n", pid, status);
 822                                 }
 823
 824                                 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
 825                                         if (worker->event != NULL) {
 826                                                 err(udev, "worker [%u] failed while handling '%s'\n",
 827                                                     pid, worker->event->devpath);
 828                                                 worker->event->exitcode = -32;
 829                                                 event_queue_delete(worker->event, true);
 830                                                 /* drop reference taken for state 'running' */
 831                                                 worker_unref(worker);
 832                                         }
 833                                 }
 834                                 worker_unref(worker);
 835                                 break;
 836                         }
 837                 }
 838                 break;
 839         case SIGHUP:
 840                 reload_config = true;
 841                 break;
 842         }
 843 }
 844
 845 static void static_dev_create_from_modules(struct udev *udev)
 846 {
 847         struct utsname kernel;
 848         char modules[UTIL_PATH_SIZE];
 849         char buf[4096];
 850         FILE *f;
 851
 852         uname(&kernel);
 853         util_strscpyl(modules, sizeof(modules), "/lib/modules/", kernel.release, "/modules.devname", NULL);
 854         f = fopen(modules, "r");
 855         if (f == NULL)
 856                 return;
 857
 858         while (fgets(buf, sizeof(buf), f) != NULL) {
 859                 char *s;
 860                 const char *modname;
 861                 const char *devname;
 862                 const char *devno;
 863                 int maj, min;
 864                 char type;
 865                 mode_t mode;
 866                 char filename[UTIL_PATH_SIZE];
 867
 868                 if (buf[0] == '#')
 869                         continue;
 870
 871                 modname = buf;
 872                 s = strchr(modname, ' ');
 873                 if (s == NULL)
 874                         continue;
 875                 s[0] = '\0';
 876
 877                 devname = &s[1];
 878                 s = strchr(devname, ' ');
 879                 if (s == NULL)
 880                         continue;
 881                 s[0] = '\0';
 882
 883                 devno = &s[1];
 884                 s = strchr(devno, ' ');
 885                 if (s == NULL)
 886                         s = strchr(devno, '\n');
 887                 if (s != NULL)
 888                         s[0] = '\0';
 889                 if (sscanf(devno, "%c%u:%u", &type, &maj, &min) != 3)
 890                         continue;
 891
 892                 /* set sticky bit, so we do not remove the node on module unload */
 893                 if (type == 'c')
 894                         mode = 01600|S_IFCHR;
 895                 else if (type == 'b')
 896                         mode = 01600|S_IFBLK;
 897                 else
 898                         continue;
 899
 900                 util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev), "/", devname, NULL);
 901                 util_create_path_selinux(udev, filename);
 902                 udev_selinux_setfscreatecon(udev, filename, mode);
 903                 info(udev, "mknod '%s' %c%u:%u\n", filename, type, maj, min);
 904                 if (mknod(filename, mode, makedev(maj, min)) < 0 && errno == EEXIST)
 905                         utimensat(AT_FDCWD, filename, NULL, 0);
 906                 udev_selinux_resetfscreatecon(udev);
 907         }
 908
 909         fclose(f);
 910 }
 911
 912 static int copy_dev_dir(struct udev *udev, DIR *dir_from, DIR *dir_to, int maxdepth)
 913 {
 914         struct dirent *dent;
 915
 916         for (dent = readdir(dir_from); dent != NULL; dent = readdir(dir_from)) {
 917                 struct stat stats;
 918
 919                 if (dent->d_name[0] == '.')
 920                         continue;
 921                 if (fstatat(dirfd(dir_from), dent->d_name, &stats, AT_SYMLINK_NOFOLLOW) != 0)
 922                         continue;
 923
 924                 if (S_ISBLK(stats.st_mode) || S_ISCHR(stats.st_mode)) {
 925                         udev_selinux_setfscreateconat(udev, dirfd(dir_to), dent->d_name, stats.st_mode & 0777);
 926                         if (mknodat(dirfd(dir_to), dent->d_name, stats.st_mode, stats.st_rdev) == 0) {
 927                                 fchmodat(dirfd(dir_to), dent->d_name, stats.st_mode & 0777, 0);
 928                                 fchownat(dirfd(dir_to), dent->d_name, stats.st_uid, stats.st_gid, 0);
 929                         } else {
 930                                 utimensat(dirfd(dir_to), dent->d_name, NULL, 0);
 931                         }
 932                         udev_selinux_resetfscreatecon(udev);
 933                 } else if (S_ISLNK(stats.st_mode)) {
 934                         char target[UTIL_PATH_SIZE];
 935                         ssize_t len;
 936
 937                         len = readlinkat(dirfd(dir_from), dent->d_name, target, sizeof(target));
 938                         if (len <= 0 || len == (ssize_t)sizeof(target))
 939                                 continue;
 940                         target[len] = '\0';
 941                         udev_selinux_setfscreateconat(udev, dirfd(dir_to), dent->d_name, S_IFLNK);
 942                         if (symlinkat(target, dirfd(dir_to), dent->d_name) < 0 && errno == EEXIST)
 943                                 utimensat(dirfd(dir_to), dent->d_name, NULL, AT_SYMLINK_NOFOLLOW);
 944                         udev_selinux_resetfscreatecon(udev);
 945                 } else if (S_ISDIR(stats.st_mode)) {
 946                         DIR *dir2_from, *dir2_to;
 947
 948                         if (maxdepth == 0)
 949                                 continue;
 950
 951                         udev_selinux_setfscreateconat(udev, dirfd(dir_to), dent->d_name, S_IFDIR|0755);
 952                         mkdirat(dirfd(dir_to), dent->d_name, 0755);
 953                         udev_selinux_resetfscreatecon(udev);
 954
 955                         dir2_to = fdopendir(openat(dirfd(dir_to), dent->d_name, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC));
 956                         if (dir2_to == NULL)
 957                                 continue;
 958
 959                         dir2_from = fdopendir(openat(dirfd(dir_from), dent->d_name, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC));
 960                         if (dir2_from == NULL) {
 961                                 closedir(dir2_to);
 962                                 continue;
 963                         }
 964
 965                         copy_dev_dir(udev, dir2_from, dir2_to, maxdepth-1);
 966
 967                         closedir(dir2_to);
 968                         closedir(dir2_from);
 969                 }
 970         }
 971
 972         return 0;
 973 }
 974
 975 static void static_dev_create_links(struct udev *udev, DIR *dir)
 976 {
 977         struct stdlinks {
 978                 const char *link;
 979                 const char *target;
 980         };
 981         static const struct stdlinks stdlinks[] = {
 982                 { "core", "/proc/kcore" },
 983                 { "fd", "/proc/self/fd" },
 984                 { "stdin", "/proc/self/fd/0" },
 985                 { "stdout", "/proc/self/fd/1" },
 986                 { "stderr", "/proc/self/fd/2" },
 987         };
 988         unsigned int i;
 989
 990         for (i = 0; i < ARRAY_SIZE(stdlinks); i++) {
 991                 struct stat sb;
 992
 993                 if (stat(stdlinks[i].target, &sb) == 0) {
 994                         udev_selinux_setfscreateconat(udev, dirfd(dir), stdlinks[i].link, S_IFLNK);
 995                         if (symlinkat(stdlinks[i].target, dirfd(dir), stdlinks[i].link) < 0 && errno == EEXIST)
 996                                 utimensat(dirfd(dir), stdlinks[i].link, NULL, AT_SYMLINK_NOFOLLOW);
 997                         udev_selinux_resetfscreatecon(udev);
 998                 }
 999         }
1000 }
1001
1002 static void static_dev_create_from_devices(struct udev *udev, DIR *dir)
1003 {
1004         DIR *dir_from;
1005
1006         dir_from = opendir(LIBEXECDIR "/devices");
1007         if (dir_from == NULL)
1008                 return;
1009         copy_dev_dir(udev, dir_from, dir, 8);
1010         closedir(dir_from);
1011 }
1012
1013 static void static_dev_create(struct udev *udev)
1014 {
1015         DIR *dir;
1016
1017         dir = opendir(udev_get_dev_path(udev));
1018         if (dir == NULL)
1019                 return;
1020
1021         static_dev_create_links(udev, dir);
1022         static_dev_create_from_devices(udev, dir);
1023
1024         closedir(dir);
1025 }
1026
1027 static int mem_size_mb(void)
1028 {
1029         FILE *f;
1030         char buf[4096];
1031         long int memsize = -1;
1032
1033         f = fopen("/proc/meminfo", "r");
1034         if (f == NULL)
1035                 return -1;
1036
1037         while (fgets(buf, sizeof(buf), f) != NULL) {
1038                 long int value;
1039
1040                 if (sscanf(buf, "MemTotal: %ld kB", &value) == 1) {
1041                         memsize = value / 1024;
1042                         break;
1043                 }
1044         }
1045
1046         fclose(f);
1047         return memsize;
1048 }
1049
1050 static int convert_db(struct udev *udev)
1051 {
1052         char filename[UTIL_PATH_SIZE];
1053         FILE *f;
1054         struct udev_enumerate *udev_enumerate;
1055         struct udev_list_entry *list_entry;
1056
1057         /* current database */
1058         util_strscpyl(filename, sizeof(filename), udev_get_run_path(udev), "/data", NULL);
1059         if (access(filename, F_OK) >= 0)
1060                 return 0;
1061
1062         /* make sure we do not get here again */
1063         util_create_path(udev, filename);
1064         mkdir(filename, 0755);
1065
1066         /* old database */
1067         util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev), "/.udev/db", NULL);
1068         if (access(filename, F_OK) < 0)
1069                 return 0;
1070
1071         f = fopen("/dev/kmsg", "w");
1072         if (f != NULL) {
1073                 fprintf(f, "<30>udevd[%u]: converting old udev database\n", getpid());
1074                 fclose(f);
1075         }
1076
1077         udev_enumerate = udev_enumerate_new(udev);
1078         if (udev_enumerate == NULL)
1079                 return -1;
1080         udev_enumerate_scan_devices(udev_enumerate);
1081         udev_list_entry_foreach(list_entry, udev_enumerate_get_list_entry(udev_enumerate)) {
1082                 struct udev_device *device;
1083
1084                 device = udev_device_new_from_syspath(udev, udev_list_entry_get_name(list_entry));
1085                 if (device == NULL)
1086                         continue;
1087
1088                 /* try to find the old database for devices without a current one */
1089                 if (udev_device_read_db(device, NULL) < 0) {
1090                         bool have_db;
1091                         const char *id;
1092                         struct stat stats;
1093                         char devpath[UTIL_PATH_SIZE];
1094                         char from[UTIL_PATH_SIZE];
1095
1096                         have_db = false;
1097
1098                         /* find database in old location */
1099                         id = udev_device_get_id_filename(device);
1100                         util_strscpyl(from, sizeof(from), udev_get_dev_path(udev), "/.udev/db/", id, NULL);
1101                         if (lstat(from, &stats) == 0) {
1102                                 if (!have_db) {
1103                                         udev_device_read_db(device, from);
1104                                         have_db = true;
1105                                 }
1106                                 unlink(from);
1107                         }
1108
1109                         /* find old database with $subsys:$sysname name */
1110                         util_strscpyl(from, sizeof(from), udev_get_dev_path(udev),
1111                                      "/.udev/db/", udev_device_get_subsystem(device), ":",
1112                                      udev_device_get_sysname(device), NULL);
1113                         if (lstat(from, &stats) == 0) {
1114                                 if (!have_db) {
1115                                         udev_device_read_db(device, from);
1116                                         have_db = true;
1117                                 }
1118                                 unlink(from);
1119                         }
1120
1121                         /* find old database with the encoded devpath name */
1122                         util_path_encode(udev_device_get_devpath(device), devpath, sizeof(devpath));
1123                         util_strscpyl(from, sizeof(from), udev_get_dev_path(udev), "/.udev/db/", devpath, NULL);
1124                         if (lstat(from, &stats) == 0) {
1125                                 if (!have_db) {
1126                                         udev_device_read_db(device, from);
1127                                         have_db = true;
1128                                 }
1129                                 unlink(from);
1130                         }
1131
1132                         /* write out new database */
1133                         if (have_db)
1134                                 udev_device_update_db(device);
1135                 }
1136                 udev_device_unref(device);
1137         }
1138         udev_enumerate_unref(udev_enumerate);
1139         return 0;
1140 }
1141
1142 static int systemd_fds(struct udev *udev, int *rctrl, int *rnetlink)
1143 {
1144         int ctrl = -1, netlink = -1;
1145         int fd, n;
1146
1147         n = sd_listen_fds(true);
1148         if (n <= 0)
1149                 return -1;
1150
1151         for (fd = SD_LISTEN_FDS_START; fd < n + SD_LISTEN_FDS_START; fd++) {
1152                 if (sd_is_socket(fd, AF_LOCAL, SOCK_SEQPACKET, -1)) {
1153                         if (ctrl >= 0)
1154                                 return -1;
1155                         ctrl = fd;
1156                         continue;
1157                 }
1158
1159                 if (sd_is_socket(fd, AF_NETLINK, SOCK_RAW, -1)) {
1160                         if (netlink >= 0)
1161                                 return -1;
1162                         netlink = fd;
1163                         continue;
1164                 }
1165
1166                 return -1;
1167         }
1168
1169         if (ctrl < 0 || netlink < 0)
1170                 return -1;
1171
1172         info(udev, "ctrl=%i netlink=%i\n", ctrl, netlink);
1173         *rctrl = ctrl;
1174         *rnetlink = netlink;
1175         return 0;
1176 }
1177
1178 int main(int argc, char *argv[])
1179 {
1180         struct udev *udev;
1181         FILE *f;
1182         sigset_t mask;
1183         int daemonize = false;
1184         int resolve_names = 1;
1185         static const struct option options[] = {
1186                 { "daemon", no_argument, NULL, 'd' },
1187                 { "debug", no_argument, NULL, 'D' },
1188                 { "children-max", required_argument, NULL, 'c' },
1189                 { "exec-delay", required_argument, NULL, 'e' },
1190                 { "resolve-names", required_argument, NULL, 'N' },
1191                 { "help", no_argument, NULL, 'h' },
1192                 { "version", no_argument, NULL, 'V' },
1193                 {}
1194         };
1195         int fd_ctrl = -1;
1196         int fd_netlink = -1;
1197         int fd_worker = -1;
1198         struct epoll_event ep_ctrl, ep_inotify, ep_signal, ep_netlink, ep_worker;
1199         struct udev_ctrl_connection *ctrl_conn = NULL;
1200         int rc = 1;
1201
1202         udev = udev_new();
1203         if (udev == NULL)
1204                 goto exit;
1205
1206         udev_log_init("udevd");
1207         udev_set_log_fn(udev, log_fn);
1208         info(udev, "version %s\n", VERSION);
1209         udev_selinux_init(udev);
1210
1211         /* make sure, that our runtime dir exists and is writable */
1212         if (utimensat(AT_FDCWD, udev_get_run_config_path(udev), NULL, 0) < 0) {
1213                 /* try to create our own subdirectory, do not create parent directories */
1214                 mkdir(udev_get_run_config_path(udev), 0755);
1215
1216                 if (utimensat(AT_FDCWD, udev_get_run_config_path(udev), NULL, 0) >= 0) {
1217                         /* directory seems writable now */
1218                         udev_set_run_path(udev, udev_get_run_config_path(udev));
1219                 } else {
1220                         /* fall back to /dev/.udev */
1221                         char filename[UTIL_PATH_SIZE];
1222
1223                         util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev), "/.udev", NULL);
1224                         if (udev_set_run_path(udev, filename) == NULL)
1225                                 goto exit;
1226                         mkdir(udev_get_run_path(udev), 0755);
1227                         err(udev, "error: runtime directory '%s' not writable, for now falling back to '%s'",
1228                             udev_get_run_config_path(udev), udev_get_run_path(udev));
1229                 }
1230         }
1231         /* relabel runtime dir only if it resides below /dev */
1232         if (strncmp(udev_get_run_path(udev), udev_get_dev_path(udev), strlen(udev_get_dev_path(udev))) == 0)
1233                 udev_selinux_lsetfilecon(udev, udev_get_run_path(udev), 0755);
1234         info(udev, "runtime dir '%s'\n", udev_get_run_path(udev));
1235
1236         for (;;) {
1237                 int option;
1238
1239                 option = getopt_long(argc, argv, "c:deDtN:hV", options, NULL);
1240                 if (option == -1)
1241                         break;
1242
1243                 switch (option) {
1244                 case 'd':
1245                         daemonize = true;
1246                         break;
1247                 case 'c':
1248                         children_max = strtoul(optarg, NULL, 0);
1249                         break;
1250                 case 'e':
1251                         exec_delay = strtoul(optarg, NULL, 0);
1252                         break;
1253                 case 'D':
1254                         debug = true;
1255                         if (udev_get_log_priority(udev) < LOG_INFO)
1256                                 udev_set_log_priority(udev, LOG_INFO);
1257                         break;
1258                 case 'N':
1259                         if (strcmp (optarg, "early") == 0) {
1260                                 resolve_names = 1;
1261                         } else if (strcmp (optarg, "late") == 0) {
1262                                 resolve_names = 0;
1263                         } else if (strcmp (optarg, "never") == 0) {
1264                                 resolve_names = -1;
1265                         } else {
1266                                 fprintf(stderr, "resolve-names must be early, late or never\n");
1267                                 err(udev, "resolve-names must be early, late or never\n");
1268                                 goto exit;
1269                         }
1270                         break;
1271                 case 'h':
1272                         printf("Usage: udevd OPTIONS\n"
1273                                "  --daemon\n"
1274                                "  --debug\n"
1275                                "  --children-max=<maximum number of workers>\n"
1276                                "  --exec-delay=<seconds to wait before executing RUN=>\n"
1277                                "  --resolve-names=early|late|never\n"
1278                                "  --version\n"
1279                                "  --help\n"
1280                                "\n");
1281                         goto exit;
1282                 case 'V':
1283                         printf("%s\n", VERSION);
1284                         goto exit;
1285                 default:
1286                         goto exit;
1287                 }
1288         }
1289
1290         /*
1291          * read the kernel commandline, in case we need to get into debug mode
1292          *   udev.log-priority=<level>              syslog priority
1293          *   udev.children-max=<number of workers>  events are fully serialized if set to 1
1294          *
1295          */
1296         f = fopen("/proc/cmdline", "r");
1297         if (f != NULL) {
1298                 char cmdline[4096];
1299
1300                 if (fgets(cmdline, sizeof(cmdline), f) != NULL) {
1301                         char *pos;
1302
1303                         pos = strstr(cmdline, "udev.log-priority=");
1304                         if (pos != NULL) {
1305                                 pos += strlen("udev.log-priority=");
1306                                 udev_set_log_priority(udev, util_log_priority(pos));
1307                         }
1308
1309                         pos = strstr(cmdline, "udev.children-max=");
1310                         if (pos != NULL) {
1311                                 pos += strlen("udev.children-max=");
1312                                 children_max = strtoul(pos, NULL, 0);
1313                         }
1314
1315                         pos = strstr(cmdline, "udev.exec-delay=");
1316                         if (pos != NULL) {
1317                                 pos += strlen("udev.exec-delay=");
1318                                 exec_delay = strtoul(pos, NULL, 0);
1319                         }
1320                 }
1321                 fclose(f);
1322         }
1323
1324         if (getuid() != 0) {
1325                 fprintf(stderr, "root privileges required\n");
1326                 err(udev, "root privileges required\n");
1327                 goto exit;
1328         }
1329
1330         /* set umask before creating any file/directory */
1331         chdir("/");
1332         umask(022);
1333
1334         /* create standard links, copy static nodes, create nodes from modules */
1335         static_dev_create(udev);
1336         static_dev_create_from_modules(udev);
1337
1338         /* before opening new files, make sure std{in,out,err} fds are in a sane state */
1339         if (daemonize) {
1340                 int fd;
1341
1342                 fd = open("/dev/null", O_RDWR);
1343                 if (fd >= 0) {
1344                         if (write(STDOUT_FILENO, 0, 0) < 0)
1345                                 dup2(fd, STDOUT_FILENO);
1346                         if (write(STDERR_FILENO, 0, 0) < 0)
1347                                 dup2(fd, STDERR_FILENO);
1348                         if (fd > STDERR_FILENO)
1349                                 close(fd);
1350                 } else {
1351                         fprintf(stderr, "cannot open /dev/null\n");
1352                         err(udev, "cannot open /dev/null\n");
1353                 }
1354         }
1355
1356         if (systemd_fds(udev, &fd_ctrl, &fd_netlink) >= 0) {
1357                 /* get control and netlink socket from from systemd */
1358                 udev_ctrl = udev_ctrl_new_from_socket_fd(udev, UDEV_CTRL_SOCK_PATH, fd_ctrl);
1359                 if (udev_ctrl == NULL) {
1360                         err(udev, "error taking over udev control socket");
1361                         rc = 1;
1362                         goto exit;
1363                 }
1364
1365                 monitor = udev_monitor_new_from_netlink_fd(udev, "kernel", fd_netlink);
1366                 if (monitor == NULL) {
1367                         err(udev, "error taking over netlink socket\n");
1368                         rc = 3;
1369                         goto exit;
1370                 }
1371         } else {
1372                 /* open control and netlink socket */
1373                 udev_ctrl = udev_ctrl_new_from_socket(udev, UDEV_CTRL_SOCK_PATH);
1374                 if (udev_ctrl == NULL) {
1375                         fprintf(stderr, "error initializing udev control socket");
1376                         err(udev, "error initializing udev control socket");
1377                         rc = 1;
1378                         goto exit;
1379                 }
1380                 fd_ctrl = udev_ctrl_get_fd(udev_ctrl);
1381
1382                 monitor = udev_monitor_new_from_netlink(udev, "kernel");
1383                 if (monitor == NULL) {
1384                         fprintf(stderr, "error initializing netlink socket\n");
1385                         err(udev, "error initializing netlink socket\n");
1386                         rc = 3;
1387                         goto exit;
1388                 }
1389                 fd_netlink = udev_monitor_get_fd(monitor);
1390         }
1391
1392         if (udev_monitor_enable_receiving(monitor) < 0) {
1393                 fprintf(stderr, "error binding netlink socket\n");
1394                 err(udev, "error binding netlink socket\n");
1395                 rc = 3;
1396                 goto exit;
1397         }
1398
1399         if (udev_ctrl_enable_receiving(udev_ctrl) < 0) {
1400                 fprintf(stderr, "error binding udev control socket\n");
1401                 err(udev, "error binding udev control socket\n");
1402                 rc = 1;
1403                 goto exit;
1404         }
1405
1406         udev_monitor_set_receive_buffer_size(monitor, 128*1024*1024);
1407
1408         /* create queue file before signalling 'ready', to make sure we block 'settle' */
1409         udev_queue_export = udev_queue_export_new(udev);
1410         if (udev_queue_export == NULL) {
1411                 err(udev, "error creating queue file\n");
1412                 goto exit;
1413         }
1414
1415         if (daemonize) {
1416                 pid_t pid;
1417                 int fd;
1418
1419                 pid = fork();
1420                 switch (pid) {
1421                 case 0:
1422                         break;
1423                 case -1:
1424                         err(udev, "fork of daemon failed: %m\n");
1425                         rc = 4;
1426                         goto exit;
1427                 default:
1428                         rc = EXIT_SUCCESS;
1429                         goto exit_keep_queue;
1430                 }
1431
1432                 setsid();
1433
1434                 fd = open("/proc/self/oom_score_adj", O_RDWR);
1435                 if (fd < 0) {
1436                         /* Fallback to old interface */
1437                         fd = open("/proc/self/oom_adj", O_RDWR);
1438                         if (fd < 0) {
1439                                 err(udev, "error disabling OOM: %m\n");
1440                         } else {
1441                                 /* OOM_DISABLE == -17 */
1442                                 write(fd, "-17", 3);
1443                                 close(fd);
1444                         }
1445                 } else {
1446                         write(fd, "-1000", 5);
1447                         close(fd);
1448                 }
1449         } else {
1450                 sd_notify(1, "READY=1");
1451         }
1452
1453         f = fopen("/dev/kmsg", "w");
1454         if (f != NULL) {
1455                 fprintf(f, "<30>udevd[%u]: starting version " VERSION "\n", getpid());
1456                 fclose(f);
1457         }
1458
1459         if (!debug) {
1460                 int fd;
1461
1462                 fd = open("/dev/null", O_RDWR);
1463                 if (fd >= 0) {
1464                         dup2(fd, STDIN_FILENO);
1465                         dup2(fd, STDOUT_FILENO);
1466                         dup2(fd, STDERR_FILENO);
1467                         close(fd);
1468                 }
1469         }
1470
1471         fd_inotify = udev_watch_init(udev);
1472         if (fd_inotify < 0) {
1473                 fprintf(stderr, "error initializing inotify\n");
1474                 err(udev, "error initializing inotify\n");
1475                 rc = 4;
1476                 goto exit;
1477         }
1478
1479         if (udev_get_rules_path(udev) != NULL) {
1480                 inotify_add_watch(fd_inotify, udev_get_rules_path(udev),
1481                                   IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
1482         } else {
1483                 char filename[UTIL_PATH_SIZE];
1484                 struct stat statbuf;
1485
1486                 inotify_add_watch(fd_inotify, LIBEXECDIR "/rules.d",
1487                                   IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
1488                 inotify_add_watch(fd_inotify, SYSCONFDIR "/udev/rules.d",
1489                                   IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
1490
1491                 /* watch dynamic rules directory */
1492                 util_strscpyl(filename, sizeof(filename), udev_get_run_path(udev), "/rules.d", NULL);
1493                 if (stat(filename, &statbuf) != 0) {
1494                         util_create_path(udev, filename);
1495                         mkdir(filename, 0755);
1496                 }
1497                 inotify_add_watch(fd_inotify, filename,
1498                                   IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
1499         }
1500         udev_watch_restore(udev);
1501
1502         /* block and listen to all signals on signalfd */
1503         sigfillset(&mask);
1504         sigprocmask(SIG_SETMASK, &mask, &sigmask_orig);
1505         fd_signal = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC);
1506         if (fd_signal < 0) {
1507                 fprintf(stderr, "error creating signalfd\n");
1508                 err(udev, "error creating signalfd\n");
1509                 rc = 5;
1510                 goto exit;
1511         }
1512
1513         /* unnamed socket from workers to the main daemon */
1514         if (socketpair(AF_LOCAL, SOCK_DGRAM|SOCK_CLOEXEC, 0, worker_watch) < 0) {
1515                 fprintf(stderr, "error creating socketpair\n");
1516                 err(udev, "error creating socketpair\n");
1517                 rc = 6;
1518                 goto exit;
1519         }
1520         fd_worker = worker_watch[READ_END];
1521
1522         rules = udev_rules_new(udev, resolve_names);
1523         if (rules == NULL) {
1524                 err(udev, "error reading rules\n");
1525                 goto exit;
1526         }
1527
1528         memset(&ep_ctrl, 0, sizeof(struct epoll_event));
1529         ep_ctrl.events = EPOLLIN;
1530         ep_ctrl.data.fd = fd_ctrl;
1531
1532         memset(&ep_inotify, 0, sizeof(struct epoll_event));
1533         ep_inotify.events = EPOLLIN;
1534         ep_inotify.data.fd = fd_inotify;
1535
1536         memset(&ep_signal, 0, sizeof(struct epoll_event));
1537         ep_signal.events = EPOLLIN;
1538         ep_signal.data.fd = fd_signal;
1539
1540         memset(&ep_netlink, 0, sizeof(struct epoll_event));
1541         ep_netlink.events = EPOLLIN;
1542         ep_netlink.data.fd = fd_netlink;
1543
1544         memset(&ep_worker, 0, sizeof(struct epoll_event));
1545         ep_worker.events = EPOLLIN;
1546         ep_worker.data.fd = fd_worker;
1547
1548         fd_ep = epoll_create1(EPOLL_CLOEXEC);
1549         if (fd_ep < 0) {
1550                 err(udev, "error creating epoll fd: %m\n");
1551                 goto exit;
1552         }
1553         if (epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_ctrl, &ep_ctrl) < 0 ||
1554             epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_inotify, &ep_inotify) < 0 ||
1555             epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_signal, &ep_signal) < 0 ||
1556             epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_netlink, &ep_netlink) < 0 ||
1557             epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_worker, &ep_worker) < 0) {
1558                 err(udev, "fail to add fds to epoll: %m\n");
1559                 goto exit;
1560         }
1561
1562         /* if needed, convert old database from earlier udev version */
1563         convert_db(udev);
1564
1565         if (children_max <= 0) {
1566                 int memsize = mem_size_mb();
1567
1568                 /* set value depending on the amount of RAM */
1569                 if (memsize > 0)
1570                         children_max = 128 + (memsize / 8);
1571                 else
1572                         children_max = 128;
1573         }
1574         info(udev, "set children_max to %u\n", children_max);
1575
1576         udev_rules_apply_static_dev_perms(rules);
1577
1578         udev_list_node_init(&event_list);
1579         udev_list_node_init(&worker_list);
1580
1581         for (;;) {
1582                 struct epoll_event ev[8];
1583                 int fdcount;
1584                 int timeout;
1585                 bool is_worker, is_signal, is_inotify, is_netlink, is_ctrl;
1586                 int i;
1587
1588                 if (udev_exit) {
1589                         /* close sources of new events and discard buffered events */
1590                         if (fd_ctrl >= 0) {
1591                                 epoll_ctl(fd_ep, EPOLL_CTL_DEL, fd_ctrl, NULL);
1592                                 fd_ctrl = -1;
1593                         }
1594                         if (monitor != NULL) {
1595                                 epoll_ctl(fd_ep, EPOLL_CTL_DEL, fd_netlink, NULL);
1596                                 udev_monitor_unref(monitor);
1597                                 monitor = NULL;
1598                         }
1599                         if (fd_inotify >= 0) {
1600                                 epoll_ctl(fd_ep, EPOLL_CTL_DEL, fd_inotify, NULL);
1601                                 close(fd_inotify);
1602                                 fd_inotify = -1;
1603                         }
1604
1605                         /* discard queued events and kill workers */
1606                         event_queue_cleanup(udev, EVENT_QUEUED);
1607                         worker_kill(udev, 0);
1608
1609                         /* exit after all has cleaned up */
1610                         if (udev_list_node_is_empty(&event_list) && udev_list_node_is_empty(&worker_list))
1611                                 break;
1612
1613                         /* timeout at exit for workers to finish */
1614                         timeout = 60 * 1000;
1615                 } else if (udev_list_node_is_empty(&event_list) && children > 2) {
1616                         /* set timeout to kill idle workers */
1617                         timeout = 3 * 1000;
1618                 } else {
1619                         timeout = -1;
1620                 }
1621                 fdcount = epoll_wait(fd_ep, ev, ARRAY_SIZE(ev), timeout);
1622                 if (fdcount < 0)
1623                         continue;
1624
1625                 if (fdcount == 0) {
1626                         if (udev_exit) {
1627                                 info(udev, "timeout, giving up waiting for workers to finish\n");
1628                                 break;
1629                         }
1630
1631                         /* timeout - kill idle workers */
1632                         worker_kill(udev, 2);
1633                 }
1634
1635                 is_worker = is_signal = is_inotify = is_netlink = is_ctrl = false;
1636                 for (i = 0; i < fdcount; i++) {
1637                         if (ev[i].data.fd == fd_worker && ev[i].events & EPOLLIN)
1638                                 is_worker = true;
1639                         else if (ev[i].data.fd == fd_netlink && ev[i].events & EPOLLIN)
1640                                 is_netlink = true;
1641                         else if (ev[i].data.fd == fd_signal && ev[i].events & EPOLLIN)
1642                                 is_signal = true;
1643                         else if (ev[i].data.fd == fd_inotify && ev[i].events & EPOLLIN)
1644                                 is_inotify = true;
1645                         else if (ev[i].data.fd == fd_ctrl && ev[i].events & EPOLLIN)
1646                                 is_ctrl = true;
1647                 }
1648
1649                 /* event has finished */
1650                 if (is_worker)
1651                         worker_returned(fd_worker);
1652
1653                 if (is_netlink) {
1654                         struct udev_device *dev;
1655
1656                         dev = udev_monitor_receive_device(monitor);
1657                         if (dev != NULL)
1658                                 if (event_queue_insert(dev) < 0)
1659                                         udev_device_unref(dev);
1660                 }
1661
1662                 /* start new events */
1663                 if (!udev_list_node_is_empty(&event_list) && !udev_exit && !stop_exec_queue)
1664                         event_queue_start(udev);
1665
1666                 if (is_signal) {
1667                         struct signalfd_siginfo fdsi;
1668                         ssize_t size;
1669
1670                         size = read(fd_signal, &fdsi, sizeof(struct signalfd_siginfo));
1671                         if (size == sizeof(struct signalfd_siginfo))
1672                                 handle_signal(udev, fdsi.ssi_signo);
1673                 }
1674
1675                 /* we are shutting down, the events below are not handled anymore */
1676                 if (udev_exit)
1677                         continue;
1678
1679                 /* device node and rules directory inotify watch */
1680                 if (is_inotify)
1681                         handle_inotify(udev);
1682
1683                 /*
1684                  * This needs to be after the inotify handling, to make sure,
1685                  * that the ping is send back after the possibly generated
1686                  * "change" events by the inotify device node watch.
1687                  *
1688                  * A single time we may receive a client connection which we need to
1689                  * keep open to block the client. It will be closed right before we
1690                  * exit.
1691                  */
1692                 if (is_ctrl)
1693                         ctrl_conn = handle_ctrl_msg(udev_ctrl);
1694
1695                 /* rules changed, set by inotify or a HUP signal */
1696                 if (reload_config) {
1697                         struct udev_rules *rules_new;
1698
1699                         worker_kill(udev, 0);
1700                         rules_new = udev_rules_new(udev, resolve_names);
1701                         if (rules_new != NULL) {
1702                                 udev_rules_unref(rules);
1703                                 rules = rules_new;
1704                         }
1705                         reload_config = 0;
1706                 }
1707         }
1708
1709         rc = EXIT_SUCCESS;
1710 exit:
1711         udev_queue_export_cleanup(udev_queue_export);
1712 exit_keep_queue:
1713         if (fd_ep >= 0)
1714                 close(fd_ep);
1715         worker_list_cleanup(udev);
1716         event_queue_cleanup(udev, EVENT_UNDEF);
1717         udev_rules_unref(rules);
1718         if (fd_signal >= 0)
1719                 close(fd_signal);
1720         if (worker_watch[READ_END] >= 0)
1721                 close(worker_watch[READ_END]);
1722         if (worker_watch[WRITE_END] >= 0)
1723                 close(worker_watch[WRITE_END]);
1724         udev_monitor_unref(monitor);
1725         udev_queue_export_unref(udev_queue_export);
1726         udev_ctrl_connection_unref(ctrl_conn);
1727         udev_ctrl_unref(udev_ctrl);
1728         udev_selinux_exit(udev);
1729         udev_unref(udev);
1730         udev_log_close();
1731         return rc;
1732 }