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 timeval tv;
  59                 struct timezone tz;
  60
  61                 vsnprintf(buf, sizeof(buf), format, args);
  62                 gettimeofday(&tv, &tz);
  63                 fprintf(stderr, "%llu.%06u [%u] %s: %s",
  64                         (unsigned long long) tv.tv_sec, (unsigned int) tv.tv_usec,
  65                         (int) getpid(), fn, buf);
  66         } else {
  67                 vsyslog(priority, format, args);
  68         }
  69 }
  70
  71 static struct udev_rules *rules;
  72 static struct udev_queue_export *udev_queue_export;
  73 static struct udev_ctrl *udev_ctrl;
  74 static struct udev_monitor *monitor;
  75 static int worker_watch[2] = { -1, -1 };
  76 static int fd_signal = -1;
  77 static int fd_ep = -1;
  78 static int fd_inotify = -1;
  79 static bool stop_exec_queue;
  80 static bool reload_config;
  81 static int children;
  82 static int children_max;
  83 static int exec_delay;
  84 static sigset_t sigmask_orig;
  85 static UDEV_LIST(event_list);
  86 static UDEV_LIST(worker_list);
  87 static bool udev_exit;
  88
  89 enum event_state {
  90         EVENT_UNDEF,
  91         EVENT_QUEUED,
  92         EVENT_RUNNING,
  93 };
  94
  95 struct event {
  96         struct udev_list_node node;
  97         struct udev *udev;
  98         struct udev_device *dev;
  99         enum event_state state;
 100         int exitcode;
 101         unsigned long long int delaying_seqnum;
 102         unsigned long long int seqnum;
 103         const char *devpath;
 104         size_t devpath_len;
 105         const char *devpath_old;
 106         dev_t devnum;
 107         bool is_block;
 108         int ifindex;
 109 };
 110
 111 static struct event *node_to_event(struct udev_list_node *node)
 112 {
 113         char *event;
 114
 115         event = (char *)node;
 116         event -= offsetof(struct event, node);
 117         return (struct event *)event;
 118 }
 119
 120 static void event_queue_cleanup(struct udev *udev, enum event_state type);
 121
 122 enum worker_state {
 123         WORKER_UNDEF,
 124         WORKER_RUNNING,
 125         WORKER_IDLE,
 126         WORKER_KILLED,
 127 };
 128
 129 struct worker {
 130         struct udev_list_node node;
 131         struct udev *udev;
 132         int refcount;
 133         pid_t pid;
 134         struct udev_monitor *monitor;
 135         enum worker_state state;
 136         struct event *event;
 137 };
 138
 139 /* passed from worker to main process */
 140 struct worker_message {
 141         pid_t pid;
 142         int exitcode;
 143 };
 144
 145 static struct worker *node_to_worker(struct udev_list_node *node)
 146 {
 147         char *worker;
 148
 149         worker = (char *)node;
 150         worker -= offsetof(struct worker, node);
 151         return (struct worker *)worker;
 152 }
 153
 154 static void event_queue_delete(struct event *event, bool export)
 155 {
 156         udev_list_node_remove(&event->node);
 157
 158         if (export) {
 159                 /* mark as failed, if "add" event returns non-zero */
 160                 if (event->exitcode != 0 && strcmp(udev_device_get_action(event->dev), "remove") != 0)
 161                         udev_queue_export_device_failed(udev_queue_export, event->dev);
 162                 else
 163                         udev_queue_export_device_finished(udev_queue_export, event->dev);
 164                 info(event->udev, "seq %llu done with %i\n", udev_device_get_seqnum(event->dev), event->exitcode);
 165         }
 166         udev_device_unref(event->dev);
 167         free(event);
 168 }
 169
 170 static struct worker *worker_ref(struct worker *worker)
 171 {
 172         worker->refcount++;
 173         return worker;
 174 }
 175
 176 static void worker_cleanup(struct worker *worker)
 177 {
 178         udev_list_node_remove(&worker->node);
 179         udev_monitor_unref(worker->monitor);
 180         children--;
 181         free(worker);
 182 }
 183
 184 static void worker_unref(struct worker *worker)
 185 {
 186         worker->refcount--;
 187         if (worker->refcount > 0)
 188                 return;
 189         info(worker->udev, "worker [%u] cleaned up\n", worker->pid);
 190         worker_cleanup(worker);
 191 }
 192
 193 static void worker_list_cleanup(struct udev *udev)
 194 {
 195         struct udev_list_node *loop, *tmp;
 196
 197         udev_list_node_foreach_safe(loop, tmp, &worker_list) {
 198                 struct worker *worker = node_to_worker(loop);
 199
 200                 worker_cleanup(worker);
 201         }
 202 }
 203
 204 static void worker_new(struct event *event)
 205 {
 206         struct udev *udev = event->udev;
 207         struct worker *worker;
 208         struct udev_monitor *worker_monitor;
 209         pid_t pid;
 210
 211         /* listen for new events */
 212         worker_monitor = udev_monitor_new_from_netlink(udev, NULL);
 213         if (worker_monitor == NULL)
 214                 return;
 215         /* allow the main daemon netlink address to send devices to the worker */
 216         udev_monitor_allow_unicast_sender(worker_monitor, monitor);
 217         udev_monitor_enable_receiving(worker_monitor);
 218
 219         worker = calloc(1, sizeof(struct worker));
 220         if (worker == NULL) {
 221                 udev_monitor_unref(worker_monitor);
 222                 return;
 223         }
 224         /* worker + event reference */
 225         worker->refcount = 2;
 226         worker->udev = udev;
 227
 228         pid = fork();
 229         switch (pid) {
 230         case 0: {
 231                 struct udev_device *dev = NULL;
 232                 int fd_monitor;
 233                 struct epoll_event ep_signal, ep_monitor;
 234                 sigset_t mask;
 235                 int rc = EXIT_SUCCESS;
 236
 237                 /* move initial device from queue */
 238                 dev = event->dev;
 239                 event->dev = NULL;
 240
 241                 free(worker);
 242                 worker_list_cleanup(udev);
 243                 event_queue_cleanup(udev, EVENT_UNDEF);
 244                 udev_queue_export_unref(udev_queue_export);
 245                 udev_monitor_unref(monitor);
 246                 udev_ctrl_unref(udev_ctrl);
 247                 close(fd_signal);
 248                 close(fd_ep);
 249                 close(worker_watch[READ_END]);
 250
 251                 sigfillset(&mask);
 252                 fd_signal = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC);
 253                 if (fd_signal < 0) {
 254                         err(udev, "error creating signalfd %m\n");
 255                         rc = 2;
 256                         goto out;
 257                 }
 258
 259                 fd_ep = epoll_create1(EPOLL_CLOEXEC);
 260                 if (fd_ep < 0) {
 261                         err(udev, "error creating epoll fd: %m\n");
 262                         rc = 3;
 263                         goto out;
 264                 }
 265
 266                 memset(&ep_signal, 0, sizeof(struct epoll_event));
 267                 ep_signal.events = EPOLLIN;
 268                 ep_signal.data.fd = fd_signal;
 269
 270                 fd_monitor = udev_monitor_get_fd(worker_monitor);
 271                 memset(&ep_monitor, 0, sizeof(struct epoll_event));
 272                 ep_monitor.events = EPOLLIN;
 273                 ep_monitor.data.fd = fd_monitor;
 274
 275                 if (epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_signal, &ep_signal) < 0 ||
 276                     epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_monitor, &ep_monitor) < 0) {
 277                         err(udev, "fail to add fds to epoll: %m\n");
 278                         rc = 4;
 279                         goto out;
 280                 }
 281
 282                 /* request TERM signal if parent exits */
 283                 prctl(PR_SET_PDEATHSIG, SIGTERM);
 284
 285                 for (;;) {
 286                         struct udev_event *udev_event;
 287                         struct worker_message msg;
 288                         int failed = 0;
 289                         int err;
 290
 291                         info(udev, "seq %llu running\n", udev_device_get_seqnum(dev));
 292                         udev_event = udev_event_new(dev);
 293                         if (udev_event == NULL) {
 294                                 rc = 5;
 295                                 goto out;
 296                         }
 297
 298                         /* needed for SIGCHLD/SIGTERM in spawn() */
 299                         udev_event->fd_signal = fd_signal;
 300
 301                         if (exec_delay > 0)
 302                                 udev_event->exec_delay = exec_delay;
 303
 304                         /* apply rules, create node, symlinks */
 305                         err = udev_event_execute_rules(udev_event, rules, &sigmask_orig);
 306
 307                         if (err == 0)
 308                                 failed = udev_event_execute_run(udev_event, &sigmask_orig);
 309
 310                         /* apply/restore inotify watch */
 311                         if (err == 0 && udev_event->inotify_watch) {
 312                                 udev_watch_begin(udev, dev);
 313                                 udev_device_update_db(dev);
 314                         }
 315
 316                         /* send processed event back to libudev listeners */
 317                         udev_monitor_send_device(worker_monitor, NULL, dev);
 318
 319                         /* send udevd the result of the event execution */
 320                         memset(&msg, 0, sizeof(struct worker_message));
 321                         if (err != 0)
 322                                 msg.exitcode = err;
 323                         else if (failed != 0)
 324                                 msg.exitcode = failed;
 325                         msg.pid = getpid();
 326                         send(worker_watch[WRITE_END], &msg, sizeof(struct worker_message), 0);
 327
 328                         info(udev, "seq %llu processed with %i\n", udev_device_get_seqnum(dev), err);
 329
 330                         udev_device_unref(dev);
 331                         dev = NULL;
 332
 333                         if (udev_event->sigterm) {
 334                                 udev_event_unref(udev_event);
 335                                 goto out;
 336                         }
 337
 338                         udev_event_unref(udev_event);
 339
 340                         /* wait for more device messages from main udevd, or term signal */
 341                         while (dev == NULL) {
 342                                 struct epoll_event ev[4];
 343                                 int fdcount;
 344                                 int i;
 345
 346                                 fdcount = epoll_wait(fd_ep, ev, ARRAY_SIZE(ev), -1);
 347                                 if (fdcount < 0) {
 348                                         if (errno == EINTR)
 349                                                 continue;
 350                                         err = -errno;
 351                                         err(udev, "failed to poll: %m\n");
 352                                         goto out;
 353                                 }
 354
 355                                 for (i = 0; i < fdcount; i++) {
 356                                         if (ev[i].data.fd == fd_monitor && ev[i].events & EPOLLIN) {
 357                                                 dev = udev_monitor_receive_device(worker_monitor);
 358                                         } else if (ev[i].data.fd == fd_signal && ev[i].events & EPOLLIN) {
 359                                                 struct signalfd_siginfo fdsi;
 360                                                 ssize_t size;
 361
 362                                                 size = read(fd_signal, &fdsi, sizeof(struct signalfd_siginfo));
 363                                                 if (size != sizeof(struct signalfd_siginfo))
 364                                                         continue;
 365                                                 switch (fdsi.ssi_signo) {
 366                                                 case SIGTERM:
 367                                                         goto out;
 368                                                 case SIGALRM:
 369                                                         rc = EXIT_FAILURE;
 370                                                         goto out;
 371                                                 }
 372                                         }
 373                                 }
 374                         }
 375                 }
 376 out:
 377                 udev_device_unref(dev);
 378                 if (fd_signal >= 0)
 379                         close(fd_signal);
 380                 if (fd_ep >= 0)
 381                         close(fd_ep);
 382                 close(fd_inotify);
 383                 close(worker_watch[WRITE_END]);
 384                 udev_rules_unref(rules);
 385                 udev_monitor_unref(worker_monitor);
 386                 udev_unref(udev);
 387                 udev_log_close();
 388                 exit(rc);
 389         }
 390         case -1:
 391                 udev_monitor_unref(worker_monitor);
 392                 event->state = EVENT_QUEUED;
 393                 free(worker);
 394                 err(udev, "fork of child failed: %m\n");
 395                 break;
 396         default:
 397                 /* close monitor, but keep address around */
 398                 udev_monitor_disconnect(worker_monitor);
 399                 worker->monitor = worker_monitor;
 400                 worker->pid = pid;
 401                 worker->state = WORKER_RUNNING;
 402                 worker->event = event;
 403                 event->state = EVENT_RUNNING;
 404                 udev_list_node_append(&worker->node, &worker_list);
 405                 children++;
 406                 info(udev, "seq %llu forked new worker [%u]\n", udev_device_get_seqnum(event->dev), pid);
 407                 break;
 408         }
 409 }
 410
 411 static void event_run(struct event *event, bool force)
 412 {
 413         struct udev_list_node *loop;
 414
 415         udev_list_node_foreach(loop, &worker_list) {
 416                 struct worker *worker = node_to_worker(loop);
 417                 ssize_t count;
 418
 419                 if (worker->state != WORKER_IDLE)
 420                         continue;
 421
 422                 count = udev_monitor_send_device(monitor, worker->monitor, event->dev);
 423                 if (count < 0) {
 424                         err(event->udev, "worker [%u] did not accept message %zi (%m), kill it\n", worker->pid, count);
 425                         kill(worker->pid, SIGKILL);
 426                         worker->state = WORKER_KILLED;
 427                         continue;
 428                 }
 429                 worker_ref(worker);
 430                 worker->event = event;
 431                 worker->state = WORKER_RUNNING;
 432                 event->state = EVENT_RUNNING;
 433                 return;
 434         }
 435
 436         if (!force && children >= children_max) {
 437                 if (children_max > 1)
 438                         info(event->udev, "maximum number (%i) of children reached\n", children);
 439                 return;
 440         }
 441
 442         /* start new worker and pass initial device */
 443         worker_new(event);
 444 }
 445
 446 static int event_queue_insert(struct udev_device *dev)
 447 {
 448         struct event *event;
 449
 450         event = calloc(1, sizeof(struct event));
 451         if (event == NULL)
 452                 return -1;
 453
 454         event->udev = udev_device_get_udev(dev);
 455         event->dev = dev;
 456         event->seqnum = udev_device_get_seqnum(dev);
 457         event->devpath = udev_device_get_devpath(dev);
 458         event->devpath_len = strlen(event->devpath);
 459         event->devpath_old = udev_device_get_devpath_old(dev);
 460         event->devnum = udev_device_get_devnum(dev);
 461         event->is_block = (strcmp("block", udev_device_get_subsystem(dev)) == 0);
 462         event->ifindex = udev_device_get_ifindex(dev);
 463
 464         udev_queue_export_device_queued(udev_queue_export, dev);
 465         info(event->udev, "seq %llu queued, '%s' '%s'\n", udev_device_get_seqnum(dev),
 466              udev_device_get_action(dev), udev_device_get_subsystem(dev));
 467
 468         event->state = EVENT_QUEUED;
 469         udev_list_node_append(&event->node, &event_list);
 470
 471         /* run all events with a timeout set immediately */
 472         if (udev_device_get_timeout(dev) > 0) {
 473                 event_run(event, true);
 474                 return 0;
 475         }
 476
 477         return 0;
 478 }
 479
 480 static void worker_kill(struct udev *udev, int retain)
 481 {
 482         struct udev_list_node *loop;
 483         int max;
 484
 485         if (children <= retain)
 486                 return;
 487
 488         max = children - retain;
 489
 490         udev_list_node_foreach(loop, &worker_list) {
 491                 struct worker *worker = node_to_worker(loop);
 492
 493                 if (max-- <= 0)
 494                         break;
 495
 496                 if (worker->state == WORKER_KILLED)
 497                         continue;
 498
 499                 worker->state = WORKER_KILLED;
 500                 kill(worker->pid, SIGTERM);
 501         }
 502 }
 503
 504 /* lookup event for identical, parent, child device */
 505 static bool is_devpath_busy(struct event *event)
 506 {
 507         struct udev_list_node *loop;
 508         size_t common;
 509
 510         /* check if queue contains events we depend on */
 511         udev_list_node_foreach(loop, &event_list) {
 512                 struct event *loop_event = node_to_event(loop);
 513
 514                 /* we already found a later event, earlier can not block us, no need to check again */
 515                 if (loop_event->seqnum < event->delaying_seqnum)
 516                         continue;
 517
 518                 /* event we checked earlier still exists, no need to check again */
 519                 if (loop_event->seqnum == event->delaying_seqnum)
 520                         return true;
 521
 522                 /* found ourself, no later event can block us */
 523                 if (loop_event->seqnum >= event->seqnum)
 524                         break;
 525
 526                 /* check major/minor */
 527                 if (major(event->devnum) != 0 && event->devnum == loop_event->devnum && event->is_block == loop_event->is_block)
 528                         return true;
 529
 530                 /* check network device ifindex */
 531                 if (event->ifindex != 0 && event->ifindex == loop_event->ifindex)
 532                         return true;
 533
 534                 /* check our old name */
 535                 if (event->devpath_old != NULL && strcmp(loop_event->devpath, event->devpath_old) == 0) {
 536                         event->delaying_seqnum = loop_event->seqnum;
 537                         return true;
 538                 }
 539
 540                 /* compare devpath */
 541                 common = MIN(loop_event->devpath_len, event->devpath_len);
 542
 543                 /* one devpath is contained in the other? */
 544                 if (memcmp(loop_event->devpath, event->devpath, common) != 0)
 545                         continue;
 546
 547                 /* identical device event found */
 548                 if (loop_event->devpath_len == event->devpath_len) {
 549                         /* devices names might have changed/swapped in the meantime */
 550                         if (major(event->devnum) != 0 && (event->devnum != loop_event->devnum || event->is_block != loop_event->is_block))
 551                                 continue;
 552                         if (event->ifindex != 0 && event->ifindex != loop_event->ifindex)
 553                                 continue;
 554                         event->delaying_seqnum = loop_event->seqnum;
 555                         return true;
 556                 }
 557
 558                 /* parent device event found */
 559                 if (event->devpath[common] == '/') {
 560                         event->delaying_seqnum = loop_event->seqnum;
 561                         return true;
 562                 }
 563
 564                 /* child device event found */
 565                 if (loop_event->devpath[common] == '/') {
 566                         event->delaying_seqnum = loop_event->seqnum;
 567                         return true;
 568                 }
 569
 570                 /* no matching device */
 571                 continue;
 572         }
 573
 574         return false;
 575 }
 576
 577 static void event_queue_start(struct udev *udev)
 578 {
 579         struct udev_list_node *loop;
 580
 581         udev_list_node_foreach(loop, &event_list) {
 582                 struct event *event = node_to_event(loop);
 583
 584                 if (event->state != EVENT_QUEUED)
 585                         continue;
 586
 587                 /* do not start event if parent or child event is still running */
 588                 if (is_devpath_busy(event)) {
 589                         dbg(udev, "delay seq %llu (%s)\n", event->seqnum, event->devpath);
 590                         continue;
 591                 }
 592
 593                 event_run(event, false);
 594         }
 595 }
 596
 597 static void event_queue_cleanup(struct udev *udev, enum event_state match_type)
 598 {
 599         struct udev_list_node *loop, *tmp;
 600
 601         udev_list_node_foreach_safe(loop, tmp, &event_list) {
 602                 struct event *event = node_to_event(loop);
 603
 604                 if (match_type != EVENT_UNDEF && match_type != event->state)
 605                         continue;
 606
 607                 event_queue_delete(event, false);
 608         }
 609 }
 610
 611 static void worker_returned(int fd_worker)
 612 {
 613         for (;;) {
 614                 struct worker_message msg;
 615                 ssize_t size;
 616                 struct udev_list_node *loop;
 617
 618                 size = recv(fd_worker, &msg, sizeof(struct worker_message), MSG_DONTWAIT);
 619                 if (size != sizeof(struct worker_message))
 620                         break;
 621
 622                 /* lookup worker who sent the signal */
 623                 udev_list_node_foreach(loop, &worker_list) {
 624                         struct worker *worker = node_to_worker(loop);
 625
 626                         if (worker->pid != msg.pid)
 627                                 continue;
 628
 629                         /* worker returned */
 630                         worker->event->exitcode = msg.exitcode;
 631                         event_queue_delete(worker->event, true);
 632                         worker->event = NULL;
 633                         if (worker->state != WORKER_KILLED)
 634                                 worker->state = WORKER_IDLE;
 635                         worker_unref(worker);
 636                         break;
 637                 }
 638         }
 639 }
 640
 641 /* receive the udevd message from userspace */
 642 static struct udev_ctrl_connection *handle_ctrl_msg(struct udev_ctrl *uctrl)
 643 {
 644         struct udev *udev = udev_ctrl_get_udev(uctrl);
 645         struct udev_ctrl_connection *ctrl_conn;
 646         struct udev_ctrl_msg *ctrl_msg = NULL;
 647         const char *str;
 648         int i;
 649
 650         ctrl_conn = udev_ctrl_get_connection(uctrl);
 651         if (ctrl_conn == NULL)
 652                 goto out;
 653
 654         ctrl_msg = udev_ctrl_receive_msg(ctrl_conn);
 655         if (ctrl_msg == NULL)
 656                 goto out;
 657
 658         i = udev_ctrl_get_set_log_level(ctrl_msg);
 659         if (i >= 0) {
 660                 info(udev, "udevd message (SET_LOG_PRIORITY) received, log_priority=%i\n", i);
 661                 udev_set_log_priority(udev, i);
 662                 worker_kill(udev, 0);
 663         }
 664
 665         if (udev_ctrl_get_stop_exec_queue(ctrl_msg) > 0) {
 666                 info(udev, "udevd message (STOP_EXEC_QUEUE) received\n");
 667                 stop_exec_queue = true;
 668         }
 669
 670         if (udev_ctrl_get_start_exec_queue(ctrl_msg) > 0) {
 671                 info(udev, "udevd message (START_EXEC_QUEUE) received\n");
 672                 stop_exec_queue = false;
 673         }
 674
 675         if (udev_ctrl_get_reload_rules(ctrl_msg) > 0) {
 676                 info(udev, "udevd message (RELOAD_RULES) received\n");
 677                 reload_config = true;
 678         }
 679
 680         str = udev_ctrl_get_set_env(ctrl_msg);
 681         if (str != NULL) {
 682                 char *key;
 683
 684                 key = strdup(str);
 685                 if (key != NULL) {
 686                         char *val;
 687
 688                         val = strchr(key, '=');
 689                         if (val != NULL) {
 690                                 val[0] = '\0';
 691                                 val = &val[1];
 692                                 if (val[0] == '\0') {
 693                                         info(udev, "udevd message (ENV) received, unset '%s'\n", key);
 694                                         udev_add_property(udev, key, NULL);
 695                                 } else {
 696                                         info(udev, "udevd message (ENV) received, set '%s=%s'\n", key, val);
 697                                         udev_add_property(udev, key, val);
 698                                 }
 699                         } else {
 700                                 err(udev, "wrong key format '%s'\n", key);
 701                         }
 702                         free(key);
 703                 }
 704                 worker_kill(udev, 0);
 705         }
 706
 707         i = udev_ctrl_get_set_children_max(ctrl_msg);
 708         if (i >= 0) {
 709                 info(udev, "udevd message (SET_MAX_CHILDREN) received, children_max=%i\n", i);
 710                 children_max = i;
 711         }
 712
 713         if (udev_ctrl_get_ping(ctrl_msg) > 0)
 714                 info(udev, "udevd message (SYNC) received\n");
 715
 716         if (udev_ctrl_get_exit(ctrl_msg) > 0) {
 717                 info(udev, "udevd message (EXIT) received\n");
 718                 udev_exit = true;
 719                 /* keep reference to block the client until we exit */
 720                 udev_ctrl_connection_ref(ctrl_conn);
 721         }
 722 out:
 723         udev_ctrl_msg_unref(ctrl_msg);
 724         return udev_ctrl_connection_unref(ctrl_conn);
 725 }
 726
 727 /* read inotify messages */
 728 static int handle_inotify(struct udev *udev)
 729 {
 730         int nbytes, pos;
 731         char *buf;
 732         struct inotify_event *ev;
 733
 734         if ((ioctl(fd_inotify, FIONREAD, &nbytes) < 0) || (nbytes <= 0))
 735                 return 0;
 736
 737         buf = malloc(nbytes);
 738         if (buf == NULL) {
 739                 err(udev, "error getting buffer for inotify\n");
 740                 return -1;
 741         }
 742
 743         nbytes = read(fd_inotify, buf, nbytes);
 744
 745         for (pos = 0; pos < nbytes; pos += sizeof(struct inotify_event) + ev->len) {
 746                 struct udev_device *dev;
 747
 748                 ev = (struct inotify_event *)(buf + pos);
 749                 if (ev->len) {
 750                         const char *s;
 751
 752                         info(udev, "inotify event: %x for %s\n", ev->mask, ev->name);
 753                         s = strstr(ev->name, ".rules");
 754                         if (s == NULL)
 755                                 continue;
 756                         if (strlen(s) != strlen(".rules"))
 757                                 continue;
 758                         reload_config = true;
 759                         continue;
 760                 }
 761
 762                 dev = udev_watch_lookup(udev, ev->wd);
 763                 if (dev != NULL) {
 764                         info(udev, "inotify event: %x for %s\n", ev->mask, udev_device_get_devnode(dev));
 765                         if (ev->mask & IN_CLOSE_WRITE) {
 766                                 char filename[UTIL_PATH_SIZE];
 767                                 int fd;
 768
 769                                 info(udev, "device %s closed, synthesising 'change'\n", udev_device_get_devnode(dev));
 770                                 util_strscpyl(filename, sizeof(filename), udev_device_get_syspath(dev), "/uevent", NULL);
 771                                 fd = open(filename, O_WRONLY);
 772                                 if (fd >= 0) {
 773                                         if (write(fd, "change", 6) < 0)
 774                                                 info(udev, "error writing uevent: %m\n");
 775                                         close(fd);
 776                                 }
 777                         }
 778                         if (ev->mask & IN_IGNORED)
 779                                 udev_watch_end(udev, dev);
 780
 781                         udev_device_unref(dev);
 782                 }
 783
 784         }
 785
 786         free(buf);
 787         return 0;
 788 }
 789
 790 static void handle_signal(struct udev *udev, int signo)
 791 {
 792         switch (signo) {
 793         case SIGINT:
 794         case SIGTERM:
 795                 udev_exit = true;
 796                 break;
 797         case SIGCHLD:
 798                 for (;;) {
 799                         pid_t pid;
 800                         int status;
 801                         struct udev_list_node *loop, *tmp;
 802
 803                         pid = waitpid(-1, &status, WNOHANG);
 804                         if (pid <= 0)
 805                                 break;
 806
 807                         udev_list_node_foreach_safe(loop, tmp, &worker_list) {
 808                                 struct worker *worker = node_to_worker(loop);
 809
 810                                 if (worker->pid != pid)
 811                                         continue;
 812
 813                                 info(udev, "worker [%u] exit\n", pid);
 814                                 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
 815                                         if (WEXITSTATUS(status))
 816                                                 err(udev, "worker [%u] unexpectedly returned with status %d\n", pid, WEXITSTATUS(status));
 817                                         else if (WIFSIGNALED(status))
 818                                           err(udev, "worker [%u] killed by signal %d (%s)\n", pid,
 819                                               WTERMSIG(status), strsignal(WTERMSIG(status)));
 820                                         else if (WIFSTOPPED(status))
 821                                                 err(udev, "worker [%u] unexpectedly stopped\n", pid);
 822                                         else if (WIFCONTINUED(status))
 823                                                 err(udev, "worker [%u] continued\n", pid);
 824
 825                                         if (worker->event != NULL) {
 826                                                 err(udev, "worker [%u] failed while handling '%s'\n", pid, worker->event->devpath);
 827                                                 worker->event->exitcode = -32;
 828                                                 event_queue_delete(worker->event, true);
 829                                                 /* drop reference from running event */
 830                                                 worker_unref(worker);
 831                                         }
 832                                 }
 833                                 worker_unref(worker);
 834                                 break;
 835                         }
 836                 }
 837                 break;
 838         case SIGHUP:
 839                 reload_config = true;
 840                 break;
 841         }
 842 }
 843
 844 static void static_dev_create_from_modules(struct udev *udev)
 845 {
 846         struct utsname kernel;
 847         char modules[UTIL_PATH_SIZE];
 848         char buf[4096];
 849         FILE *f;
 850
 851         uname(&kernel);
 852         util_strscpyl(modules, sizeof(modules), "/lib/modules/", kernel.release, "/modules.devname", NULL);
 853         f = fopen(modules, "r");
 854         if (f == NULL)
 855                 return;
 856
 857         while (fgets(buf, sizeof(buf), f) != NULL) {
 858                 char *s;
 859                 const char *modname;
 860                 const char *devname;
 861                 const char *devno;
 862                 int maj, min;
 863                 char type;
 864                 mode_t mode;
 865                 char filename[UTIL_PATH_SIZE];
 866
 867                 if (buf[0] == '#')
 868                         continue;
 869
 870                 modname = buf;
 871                 s = strchr(modname, ' ');
 872                 if (s == NULL)
 873                         continue;
 874                 s[0] = '\0';
 875
 876                 devname = &s[1];
 877                 s = strchr(devname, ' ');
 878                 if (s == NULL)
 879                         continue;
 880                 s[0] = '\0';
 881
 882                 devno = &s[1];
 883                 s = strchr(devno, ' ');
 884                 if (s == NULL)
 885                         s = strchr(devno, '\n');
 886                 if (s != NULL)
 887                         s[0] = '\0';
 888                 if (sscanf(devno, "%c%u:%u", &type, &maj, &min) != 3)
 889                         continue;
 890
 891                 if (type == 'c')
 892                         mode = 0600 | S_IFCHR;
 893                 else if (type == 'b')
 894                         mode = 0600 | S_IFBLK;
 895                 else
 896                         continue;
 897
 898                 util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev), "/", devname, NULL);
 899                 util_create_path_selinux(udev, filename);
 900                 udev_selinux_setfscreatecon(udev, filename, mode);
 901                 info(udev, "mknod '%s' %c%u:%u\n", filename, type, maj, min);
 902                 if (mknod(filename, mode, makedev(maj, min)) < 0 && errno == EEXIST)
 903                         utimensat(AT_FDCWD, filename, NULL, 0);
 904                 udev_selinux_resetfscreatecon(udev);
 905         }
 906
 907         fclose(f);
 908 }
 909
 910 static int copy_dev_dir(struct udev *udev, DIR *dir_from, DIR *dir_to, int maxdepth)
 911 {
 912         struct dirent *dent;
 913
 914         for (dent = readdir(dir_from); dent != NULL; dent = readdir(dir_from)) {
 915                 struct stat stats;
 916
 917                 if (dent->d_name[0] == '.')
 918                         continue;
 919                 if (fstatat(dirfd(dir_from), dent->d_name, &stats, AT_SYMLINK_NOFOLLOW) != 0)
 920                         continue;
 921
 922                 if (S_ISBLK(stats.st_mode) || S_ISCHR(stats.st_mode)) {
 923                         udev_selinux_setfscreateconat(udev, dirfd(dir_to), dent->d_name, stats.st_mode & 0777);
 924                         if (mknodat(dirfd(dir_to), dent->d_name, stats.st_mode, stats.st_rdev) == 0) {
 925                                 fchmodat(dirfd(dir_to), dent->d_name, stats.st_mode & 0777, 0);
 926                                 fchownat(dirfd(dir_to), dent->d_name, stats.st_uid, stats.st_gid, 0);
 927                         } else {
 928                                 utimensat(dirfd(dir_to), dent->d_name, NULL, 0);
 929                         }
 930                         udev_selinux_resetfscreatecon(udev);
 931                 } else if (S_ISLNK(stats.st_mode)) {
 932                         char target[UTIL_PATH_SIZE];
 933                         ssize_t len;
 934
 935                         len = readlinkat(dirfd(dir_from), dent->d_name, target, sizeof(target));
 936                         if (len <= 0 || len == (ssize_t)sizeof(target))
 937                                 continue;
 938                         target[len] = '\0';
 939                         udev_selinux_setfscreateconat(udev, dirfd(dir_to), dent->d_name, S_IFLNK);
 940                         if (symlinkat(target, dirfd(dir_to), dent->d_name) < 0 && errno == EEXIST)
 941                                 utimensat(dirfd(dir_to), dent->d_name, NULL, AT_SYMLINK_NOFOLLOW);
 942                         udev_selinux_resetfscreatecon(udev);
 943                 } else if (S_ISDIR(stats.st_mode)) {
 944                         DIR *dir2_from, *dir2_to;
 945
 946                         if (maxdepth == 0)
 947                                 continue;
 948
 949                         udev_selinux_setfscreateconat(udev, dirfd(dir_to), dent->d_name, S_IFDIR|0755);
 950                         mkdirat(dirfd(dir_to), dent->d_name, 0755);
 951                         udev_selinux_resetfscreatecon(udev);
 952
 953                         dir2_to = fdopendir(openat(dirfd(dir_to), dent->d_name, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC));
 954                         if (dir2_to == NULL)
 955                                 continue;
 956
 957                         dir2_from = fdopendir(openat(dirfd(dir_from), dent->d_name, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC));
 958                         if (dir2_from == NULL) {
 959                                 closedir(dir2_to);
 960                                 continue;
 961                         }
 962
 963                         copy_dev_dir(udev, dir2_from, dir2_to, maxdepth-1);
 964
 965                         closedir(dir2_to);
 966                         closedir(dir2_from);
 967                 }
 968         }
 969
 970         return 0;
 971 }
 972
 973 static void static_dev_create_links(struct udev *udev, DIR *dir)
 974 {
 975         struct stdlinks {
 976                 const char *link;
 977                 const char *target;
 978         };
 979         static const struct stdlinks stdlinks[] = {
 980                 { "core", "/proc/kcore" },
 981                 { "fd", "/proc/self/fd" },
 982                 { "stdin", "/proc/self/fd/0" },
 983                 { "stdout", "/proc/self/fd/1" },
 984                 { "stderr", "/proc/self/fd/2" },
 985         };
 986         unsigned int i;
 987
 988         for (i = 0; i < ARRAY_SIZE(stdlinks); i++) {
 989                 struct stat sb;
 990
 991                 if (stat(stdlinks[i].target, &sb) == 0) {
 992                         udev_selinux_setfscreateconat(udev, dirfd(dir), stdlinks[i].link, S_IFLNK);
 993                         if (symlinkat(stdlinks[i].target, dirfd(dir), stdlinks[i].link) < 0 && errno == EEXIST)
 994                                 utimensat(dirfd(dir), stdlinks[i].link, NULL, AT_SYMLINK_NOFOLLOW);
 995                         udev_selinux_resetfscreatecon(udev);
 996                 }
 997         }
 998 }
 999
1000 static void static_dev_create_from_devices(struct udev *udev, DIR *dir)
1001 {
1002         DIR *dir_from;
1003
1004         dir_from = opendir(LIBEXECDIR "/devices");
1005         if (dir_from == NULL)
1006                 return;
1007         copy_dev_dir(udev, dir_from, dir, 8);
1008         closedir(dir_from);
1009 }
1010
1011 static void static_dev_create(struct udev *udev)
1012 {
1013         DIR *dir;
1014
1015         dir = opendir(udev_get_dev_path(udev));
1016         if (dir == NULL)
1017                 return;
1018
1019         static_dev_create_links(udev, dir);
1020         static_dev_create_from_devices(udev, dir);
1021
1022         closedir(dir);
1023 }
1024
1025 static int mem_size_mb(void)
1026 {
1027         FILE *f;
1028         char buf[4096];
1029         long int memsize = -1;
1030
1031         f = fopen("/proc/meminfo", "r");
1032         if (f == NULL)
1033                 return -1;
1034
1035         while (fgets(buf, sizeof(buf), f) != NULL) {
1036                 long int value;
1037
1038                 if (sscanf(buf, "MemTotal: %ld kB", &value) == 1) {
1039                         memsize = value / 1024;
1040                         break;
1041                 }
1042         }
1043
1044         fclose(f);
1045         return memsize;
1046 }
1047
1048 static int convert_db(struct udev *udev)
1049 {
1050         char filename[UTIL_PATH_SIZE];
1051         FILE *f;
1052         struct udev_enumerate *udev_enumerate;
1053         struct udev_list_entry *list_entry;
1054
1055         /* current database */
1056         util_strscpyl(filename, sizeof(filename), udev_get_run_path(udev), "/data", NULL);
1057         if (access(filename, F_OK) >= 0)
1058                 return 0;
1059
1060         /* make sure we do not get here again */
1061         util_create_path(udev, filename);
1062         mkdir(filename, 0755);
1063
1064         /* old database */
1065         util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev), "/.udev/db", NULL);
1066         if (access(filename, F_OK) < 0)
1067                 return 0;
1068
1069         f = fopen("/dev/kmsg", "w");
1070         if (f != NULL) {
1071                 fprintf(f, "<30>udevd[%u]: converting old udev database\n", getpid());
1072                 fclose(f);
1073         }
1074
1075         udev_enumerate = udev_enumerate_new(udev);
1076         if (udev_enumerate == NULL)
1077                 return -1;
1078         udev_enumerate_scan_devices(udev_enumerate);
1079         udev_list_entry_foreach(list_entry, udev_enumerate_get_list_entry(udev_enumerate)) {
1080                 struct udev_device *device;
1081
1082                 device = udev_device_new_from_syspath(udev, udev_list_entry_get_name(list_entry));
1083                 if (device == NULL)
1084                         continue;
1085
1086                 /* try to find the old database for devices without a current one */
1087                 if (udev_device_read_db(device, NULL) < 0) {
1088                         bool have_db;
1089                         const char *id;
1090                         struct stat stats;
1091                         char devpath[UTIL_PATH_SIZE];
1092                         char from[UTIL_PATH_SIZE];
1093
1094                         have_db = false;
1095
1096                         /* find database in old location */
1097                         id = udev_device_get_id_filename(device);
1098                         util_strscpyl(from, sizeof(from), udev_get_dev_path(udev), "/.udev/db/", id, NULL);
1099                         if (lstat(from, &stats) == 0) {
1100                                 if (!have_db) {
1101                                         udev_device_read_db(device, from);
1102                                         have_db = true;
1103                                 }
1104                                 unlink(from);
1105                         }
1106
1107                         /* find old database with $subsys:$sysname name */
1108                         util_strscpyl(from, sizeof(from), udev_get_dev_path(udev),
1109                                      "/.udev/db/", udev_device_get_subsystem(device), ":",
1110                                      udev_device_get_sysname(device), NULL);
1111                         if (lstat(from, &stats) == 0) {
1112                                 if (!have_db) {
1113                                         udev_device_read_db(device, from);
1114                                         have_db = true;
1115                                 }
1116                                 unlink(from);
1117                         }
1118
1119                         /* find old database with the encoded devpath name */
1120                         util_path_encode(udev_device_get_devpath(device), devpath, sizeof(devpath));
1121                         util_strscpyl(from, sizeof(from), udev_get_dev_path(udev), "/.udev/db/", devpath, NULL);
1122                         if (lstat(from, &stats) == 0) {
1123                                 if (!have_db) {
1124                                         udev_device_read_db(device, from);
1125                                         have_db = true;
1126                                 }
1127                                 unlink(from);
1128                         }
1129
1130                         /* write out new database */
1131                         if (have_db)
1132                                 udev_device_update_db(device);
1133                 }
1134                 udev_device_unref(device);
1135         }
1136         udev_enumerate_unref(udev_enumerate);
1137         return 0;
1138 }
1139
1140 static int systemd_fds(struct udev *udev, int *rctrl, int *rnetlink)
1141 {
1142         int ctrl = -1, netlink = -1;
1143         int fd, n;
1144
1145         n = sd_listen_fds(true);
1146         if (n <= 0)
1147                 return -1;
1148
1149         for (fd = SD_LISTEN_FDS_START; fd < n + SD_LISTEN_FDS_START; fd++) {
1150                 if (sd_is_socket(fd, AF_LOCAL, SOCK_SEQPACKET, -1)) {
1151                         if (ctrl >= 0)
1152                                 return -1;
1153                         ctrl = fd;
1154                         continue;
1155                 }
1156
1157                 if (sd_is_socket(fd, AF_NETLINK, SOCK_RAW, -1)) {
1158                         if (netlink >= 0)
1159                                 return -1;
1160                         netlink = fd;
1161                         continue;
1162                 }
1163
1164                 return -1;
1165         }
1166
1167         if (ctrl < 0 || netlink < 0)
1168                 return -1;
1169
1170         info(udev, "ctrl=%i netlink=%i\n", ctrl, netlink);
1171         *rctrl = ctrl;
1172         *rnetlink = netlink;
1173         return 0;
1174 }
1175
1176 int main(int argc, char *argv[])
1177 {
1178         struct udev *udev;
1179         FILE *f;
1180         sigset_t mask;
1181         int daemonize = false;
1182         int resolve_names = 1;
1183         static const struct option options[] = {
1184                 { "daemon", no_argument, NULL, 'd' },
1185                 { "debug", no_argument, NULL, 'D' },
1186                 { "children-max", required_argument, NULL, 'c' },
1187                 { "exec-delay", required_argument, NULL, 'e' },
1188                 { "resolve-names", required_argument, NULL, 'N' },
1189                 { "help", no_argument, NULL, 'h' },
1190                 { "version", no_argument, NULL, 'V' },
1191                 {}
1192         };
1193         int fd_ctrl = -1;
1194         int fd_netlink = -1;
1195         int fd_worker = -1;
1196         struct epoll_event ep_ctrl, ep_inotify, ep_signal, ep_netlink, ep_worker;
1197         struct udev_ctrl_connection *ctrl_conn = NULL;
1198         int rc = 1;
1199
1200         udev = udev_new();
1201         if (udev == NULL)
1202                 goto exit;
1203
1204         udev_log_init("udevd");
1205         udev_set_log_fn(udev, log_fn);
1206         info(udev, "version %s\n", VERSION);
1207         udev_selinux_init(udev);
1208
1209         /* make sure, that our runtime dir exists and is writable */
1210         if (utimensat(AT_FDCWD, udev_get_run_config_path(udev), NULL, 0) < 0) {
1211                 /* try to create our own subdirectory, do not create parent directories */
1212                 mkdir(udev_get_run_config_path(udev), 0755);
1213
1214                 if (utimensat(AT_FDCWD, udev_get_run_config_path(udev), NULL, 0) >= 0) {
1215                         /* directory seems writable now */
1216                         udev_set_run_path(udev, udev_get_run_config_path(udev));
1217                 } else {
1218                         /* fall back to /dev/.udev */
1219                         char filename[UTIL_PATH_SIZE];
1220
1221                         util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev), "/.udev", NULL);
1222                         if (udev_set_run_path(udev, filename) == NULL)
1223                                 goto exit;
1224                         mkdir(udev_get_run_path(udev), 0755);
1225                         err(udev, "error: runtime directory '%s' not writable, for now falling back to '%s'",
1226                             udev_get_run_config_path(udev), udev_get_run_path(udev));
1227                 }
1228         }
1229         /* relabel runtime dir only if it resides below /dev */
1230         if (strncmp(udev_get_run_path(udev), udev_get_dev_path(udev), strlen(udev_get_dev_path(udev))) == 0)
1231                 udev_selinux_lsetfilecon(udev, udev_get_run_path(udev), 0755);
1232         info(udev, "runtime dir '%s'\n", udev_get_run_path(udev));
1233
1234         for (;;) {
1235                 int option;
1236
1237                 option = getopt_long(argc, argv, "c:deDtN:hV", options, NULL);
1238                 if (option == -1)
1239                         break;
1240
1241                 switch (option) {
1242                 case 'd':
1243                         daemonize = true;
1244                         break;
1245                 case 'c':
1246                         children_max = strtoul(optarg, NULL, 0);
1247                         break;
1248                 case 'e':
1249                         exec_delay = strtoul(optarg, NULL, 0);
1250                         break;
1251                 case 'D':
1252                         debug = true;
1253                         if (udev_get_log_priority(udev) < LOG_INFO)
1254                                 udev_set_log_priority(udev, LOG_INFO);
1255                         break;
1256                 case 'N':
1257                         if (strcmp (optarg, "early") == 0) {
1258                                 resolve_names = 1;
1259                         } else if (strcmp (optarg, "late") == 0) {
1260                                 resolve_names = 0;
1261                         } else if (strcmp (optarg, "never") == 0) {
1262                                 resolve_names = -1;
1263                         } else {
1264                                 fprintf(stderr, "resolve-names must be early, late or never\n");
1265                                 err(udev, "resolve-names must be early, late or never\n");
1266                                 goto exit;
1267                         }
1268                         break;
1269                 case 'h':
1270                         printf("Usage: udevd OPTIONS\n"
1271                                "  --daemon\n"
1272                                "  --debug\n"
1273                                "  --children-max=<maximum number of workers>\n"
1274                                "  --exec-delay=<seconds to wait before executing RUN=>\n"
1275                                "  --resolve-names=early|late|never\n"
1276                                "  --version\n"
1277                                "  --help\n"
1278                                "\n");
1279                         goto exit;
1280                 case 'V':
1281                         printf("%s\n", VERSION);
1282                         goto exit;
1283                 default:
1284                         goto exit;
1285                 }
1286         }
1287
1288         /*
1289          * read the kernel commandline, in case we need to get into debug mode
1290          *   udev.log-priority=<level>              syslog priority
1291          *   udev.children-max=<number of workers>  events are fully serialized if set to 1
1292          *
1293          */
1294         f = fopen("/proc/cmdline", "r");
1295         if (f != NULL) {
1296                 char cmdline[4096];
1297
1298                 if (fgets(cmdline, sizeof(cmdline), f) != NULL) {
1299                         char *pos;
1300
1301                         pos = strstr(cmdline, "udev.log-priority=");
1302                         if (pos != NULL) {
1303                                 pos += strlen("udev.log-priority=");
1304                                 udev_set_log_priority(udev, util_log_priority(pos));
1305                         }
1306
1307                         pos = strstr(cmdline, "udev.children-max=");
1308                         if (pos != NULL) {
1309                                 pos += strlen("udev.children-max=");
1310                                 children_max = strtoul(pos, NULL, 0);
1311                         }
1312
1313                         pos = strstr(cmdline, "udev.exec-delay=");
1314                         if (pos != NULL) {
1315                                 pos += strlen("udev.exec-delay=");
1316                                 exec_delay = strtoul(pos, NULL, 0);
1317                         }
1318                 }
1319                 fclose(f);
1320         }
1321
1322         if (getuid() != 0) {
1323                 fprintf(stderr, "root privileges required\n");
1324                 err(udev, "root privileges required\n");
1325                 goto exit;
1326         }
1327
1328         /* set umask before creating any file/directory */
1329         chdir("/");
1330         umask(022);
1331
1332         /* create standard links, copy static nodes, create nodes from modules */
1333         static_dev_create(udev);
1334         static_dev_create_from_modules(udev);
1335
1336         /* before opening new files, make sure std{in,out,err} fds are in a sane state */
1337         if (daemonize) {
1338                 int fd;
1339
1340                 fd = open("/dev/null", O_RDWR);
1341                 if (fd >= 0) {
1342                         if (write(STDOUT_FILENO, 0, 0) < 0)
1343                                 dup2(fd, STDOUT_FILENO);
1344                         if (write(STDERR_FILENO, 0, 0) < 0)
1345                                 dup2(fd, STDERR_FILENO);
1346                         if (fd > STDERR_FILENO)
1347                                 close(fd);
1348                 } else {
1349                         fprintf(stderr, "cannot open /dev/null\n");
1350                         err(udev, "cannot open /dev/null\n");
1351                 }
1352         }
1353
1354         if (systemd_fds(udev, &fd_ctrl, &fd_netlink) >= 0) {
1355                 /* get control and netlink socket from from systemd */
1356                 udev_ctrl = udev_ctrl_new_from_socket_fd(udev, UDEV_CTRL_SOCK_PATH, fd_ctrl);
1357                 if (udev_ctrl == NULL) {
1358                         err(udev, "error taking over udev control socket");
1359                         rc = 1;
1360                         goto exit;
1361                 }
1362
1363                 monitor = udev_monitor_new_from_netlink_fd(udev, "kernel", fd_netlink);
1364                 if (monitor == NULL) {
1365                         err(udev, "error taking over netlink socket\n");
1366                         rc = 3;
1367                         goto exit;
1368                 }
1369         } else {
1370                 /* open control and netlink socket */
1371                 udev_ctrl = udev_ctrl_new_from_socket(udev, UDEV_CTRL_SOCK_PATH);
1372                 if (udev_ctrl == NULL) {
1373                         fprintf(stderr, "error initializing udev control socket");
1374                         err(udev, "error initializing udev control socket");
1375                         rc = 1;
1376                         goto exit;
1377                 }
1378                 fd_ctrl = udev_ctrl_get_fd(udev_ctrl);
1379
1380                 monitor = udev_monitor_new_from_netlink(udev, "kernel");
1381                 if (monitor == NULL) {
1382                         fprintf(stderr, "error initializing netlink socket\n");
1383                         err(udev, "error initializing netlink socket\n");
1384                         rc = 3;
1385                         goto exit;
1386                 }
1387                 fd_netlink = udev_monitor_get_fd(monitor);
1388         }
1389
1390         if (udev_monitor_enable_receiving(monitor) < 0) {
1391                 fprintf(stderr, "error binding netlink socket\n");
1392                 err(udev, "error binding netlink socket\n");
1393                 rc = 3;
1394                 goto exit;
1395         }
1396
1397         if (udev_ctrl_enable_receiving(udev_ctrl) < 0) {
1398                 fprintf(stderr, "error binding udev control socket\n");
1399                 err(udev, "error binding udev control socket\n");
1400                 rc = 1;
1401                 goto exit;
1402         }
1403
1404         udev_monitor_set_receive_buffer_size(monitor, 128*1024*1024);
1405
1406         if (daemonize) {
1407                 pid_t pid;
1408                 int fd;
1409
1410                 pid = fork();
1411                 switch (pid) {
1412                 case 0:
1413                         break;
1414                 case -1:
1415                         err(udev, "fork of daemon failed: %m\n");
1416                         rc = 4;
1417                         goto exit;
1418                 default:
1419                         rc = 0;
1420                         goto exit;
1421                 }
1422
1423                 setsid();
1424
1425                 fd = open("/proc/self/oom_score_adj", O_RDWR);
1426                 if (fd < 0) {
1427                         /* Fallback to old interface */
1428                         fd = open("/proc/self/oom_adj", O_RDWR);
1429                         if (fd < 0) {
1430                                 err(udev, "error disabling OOM: %m\n");
1431                         } else {
1432                                 /* OOM_DISABLE == -17 */
1433                                 write(fd, "-17", 3);
1434                                 close(fd);
1435                         }
1436                 } else {
1437                         write(fd, "-1000", 5);
1438                         close(fd);
1439                 }
1440         } else {
1441                 sd_notify(1, "READY=1");
1442         }
1443
1444         f = fopen("/dev/kmsg", "w");
1445         if (f != NULL) {
1446                 fprintf(f, "<30>udevd[%u]: starting version " VERSION "\n", getpid());
1447                 fclose(f);
1448         }
1449
1450         if (!debug) {
1451                 int fd;
1452
1453                 fd = open("/dev/null", O_RDWR);
1454                 if (fd >= 0) {
1455                         dup2(fd, STDIN_FILENO);
1456                         dup2(fd, STDOUT_FILENO);
1457                         dup2(fd, STDERR_FILENO);
1458                         close(fd);
1459                 }
1460         }
1461
1462         fd_inotify = udev_watch_init(udev);
1463         if (fd_inotify < 0) {
1464                 fprintf(stderr, "error initializing inotify\n");
1465                 err(udev, "error initializing inotify\n");
1466                 rc = 4;
1467                 goto exit;
1468         }
1469
1470         if (udev_get_rules_path(udev) != NULL) {
1471                 inotify_add_watch(fd_inotify, udev_get_rules_path(udev),
1472                                   IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
1473         } else {
1474                 char filename[UTIL_PATH_SIZE];
1475                 struct stat statbuf;
1476
1477                 inotify_add_watch(fd_inotify, LIBEXECDIR "/rules.d",
1478                                   IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
1479                 inotify_add_watch(fd_inotify, SYSCONFDIR "/udev/rules.d",
1480                                   IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
1481
1482                 /* watch dynamic rules directory */
1483                 util_strscpyl(filename, sizeof(filename), udev_get_run_path(udev), "/rules.d", NULL);
1484                 if (stat(filename, &statbuf) != 0) {
1485                         util_create_path(udev, filename);
1486                         mkdir(filename, 0755);
1487                 }
1488                 inotify_add_watch(fd_inotify, filename,
1489                                   IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
1490         }
1491         udev_watch_restore(udev);
1492
1493         /* block and listen to all signals on signalfd */
1494         sigfillset(&mask);
1495         sigprocmask(SIG_SETMASK, &mask, &sigmask_orig);
1496         fd_signal = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC);
1497         if (fd_signal < 0) {
1498                 fprintf(stderr, "error creating signalfd\n");
1499                 err(udev, "error creating signalfd\n");
1500                 rc = 5;
1501                 goto exit;
1502         }
1503
1504         /* unnamed socket from workers to the main daemon */
1505         if (socketpair(AF_LOCAL, SOCK_DGRAM|SOCK_CLOEXEC, 0, worker_watch) < 0) {
1506                 fprintf(stderr, "error creating socketpair\n");
1507                 err(udev, "error creating socketpair\n");
1508                 rc = 6;
1509                 goto exit;
1510         }
1511         fd_worker = worker_watch[READ_END];
1512
1513         rules = udev_rules_new(udev, resolve_names);
1514         if (rules == NULL) {
1515                 err(udev, "error reading rules\n");
1516                 goto exit;
1517         }
1518
1519         udev_queue_export = udev_queue_export_new(udev);
1520         if (udev_queue_export == NULL) {
1521                 err(udev, "error creating queue file\n");
1522                 goto exit;
1523         }
1524
1525         memset(&ep_ctrl, 0, sizeof(struct epoll_event));
1526         ep_ctrl.events = EPOLLIN;
1527         ep_ctrl.data.fd = fd_ctrl;
1528
1529         memset(&ep_inotify, 0, sizeof(struct epoll_event));
1530         ep_inotify.events = EPOLLIN;
1531         ep_inotify.data.fd = fd_inotify;
1532
1533         memset(&ep_signal, 0, sizeof(struct epoll_event));
1534         ep_signal.events = EPOLLIN;
1535         ep_signal.data.fd = fd_signal;
1536
1537         memset(&ep_netlink, 0, sizeof(struct epoll_event));
1538         ep_netlink.events = EPOLLIN;
1539         ep_netlink.data.fd = fd_netlink;
1540
1541         memset(&ep_worker, 0, sizeof(struct epoll_event));
1542         ep_worker.events = EPOLLIN;
1543         ep_worker.data.fd = fd_worker;
1544
1545         fd_ep = epoll_create1(EPOLL_CLOEXEC);
1546         if (fd_ep < 0) {
1547                 err(udev, "error creating epoll fd: %m\n");
1548                 goto exit;
1549         }
1550         if (epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_ctrl, &ep_ctrl) < 0 ||
1551             epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_inotify, &ep_inotify) < 0 ||
1552             epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_signal, &ep_signal) < 0 ||
1553             epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_netlink, &ep_netlink) < 0 ||
1554             epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_worker, &ep_worker) < 0) {
1555                 err(udev, "fail to add fds to epoll: %m\n");
1556                 goto exit;
1557         }
1558
1559         /* if needed, convert old database from earlier udev version */
1560         convert_db(udev);
1561
1562         if (children_max <= 0) {
1563                 int memsize = mem_size_mb();
1564
1565                 /* set value depending on the amount of RAM */
1566                 if (memsize > 0)
1567                         children_max = 128 + (memsize / 8);
1568                 else
1569                         children_max = 128;
1570         }
1571         info(udev, "set children_max to %u\n", children_max);
1572
1573         udev_rules_apply_static_dev_perms(rules);
1574
1575         udev_list_init(&event_list);
1576         udev_list_init(&worker_list);
1577
1578         for (;;) {
1579                 struct epoll_event ev[8];
1580                 int fdcount;
1581                 int timeout;
1582                 bool is_worker, is_signal, is_inotify, is_netlink, is_ctrl;
1583                 int i;
1584
1585                 if (udev_exit) {
1586                         /* close sources of new events and discard buffered events */
1587                         if (fd_ctrl >= 0) {
1588                                 epoll_ctl(fd_ep, EPOLL_CTL_DEL, fd_ctrl, NULL);
1589                                 fd_ctrl = -1;
1590                         }
1591                         if (monitor != NULL) {
1592                                 epoll_ctl(fd_ep, EPOLL_CTL_DEL, fd_netlink, NULL);
1593                                 udev_monitor_unref(monitor);
1594                                 monitor = NULL;
1595                         }
1596                         if (fd_inotify >= 0) {
1597                                 epoll_ctl(fd_ep, EPOLL_CTL_DEL, fd_inotify, NULL);
1598                                 close(fd_inotify);
1599                                 fd_inotify = -1;
1600                         }
1601
1602                         /* discard queued events and kill workers */
1603                         event_queue_cleanup(udev, EVENT_QUEUED);
1604                         worker_kill(udev, 0);
1605
1606                         /* exit after all has cleaned up */
1607                         if (udev_list_is_empty(&event_list) && udev_list_is_empty(&worker_list))
1608                                 break;
1609
1610                         /* timeout at exit for workers to finish */
1611                         timeout = 60 * 1000;
1612                 } else if (udev_list_is_empty(&event_list) && children > 2) {
1613                         /* set timeout to kill idle workers */
1614                         timeout = 3 * 1000;
1615                 } else {
1616                         timeout = -1;
1617                 }
1618                 fdcount = epoll_wait(fd_ep, ev, ARRAY_SIZE(ev), timeout);
1619                 if (fdcount < 0)
1620                         continue;
1621
1622                 if (fdcount == 0) {
1623                         if (udev_exit) {
1624                                 info(udev, "timeout, giving up waiting for workers to finish\n");
1625                                 break;
1626                         }
1627
1628                         /* timeout - kill idle workers */
1629                         worker_kill(udev, 2);
1630                 }
1631
1632                 is_worker = is_signal = is_inotify = is_netlink = is_ctrl = false;
1633                 for (i = 0; i < fdcount; i++) {
1634                         if (ev[i].data.fd == fd_worker && ev[i].events & EPOLLIN)
1635                                 is_worker = true;
1636                         else if (ev[i].data.fd == fd_netlink && ev[i].events & EPOLLIN)
1637                                 is_netlink = true;
1638                         else if (ev[i].data.fd == fd_signal && ev[i].events & EPOLLIN)
1639                                 is_signal = true;
1640                         else if (ev[i].data.fd == fd_inotify && ev[i].events & EPOLLIN)
1641                                 is_inotify = true;
1642                         else if (ev[i].data.fd == fd_ctrl && ev[i].events & EPOLLIN)
1643                                 is_ctrl = true;
1644                 }
1645
1646                 /* event has finished */
1647                 if (is_worker)
1648                         worker_returned(fd_worker);
1649
1650                 if (is_netlink) {
1651                         struct udev_device *dev;
1652
1653                         dev = udev_monitor_receive_device(monitor);
1654                         if (dev != NULL)
1655                                 if (event_queue_insert(dev) < 0)
1656                                         udev_device_unref(dev);
1657                 }
1658
1659                 /* start new events */
1660                 if (!udev_list_is_empty(&event_list) && !udev_exit && !stop_exec_queue)
1661                         event_queue_start(udev);
1662
1663                 if (is_signal) {
1664                         struct signalfd_siginfo fdsi;
1665                         ssize_t size;
1666
1667                         size = read(fd_signal, &fdsi, sizeof(struct signalfd_siginfo));
1668                         if (size == sizeof(struct signalfd_siginfo))
1669                                 handle_signal(udev, fdsi.ssi_signo);
1670                 }
1671
1672                 /* we are shutting down, the events below are not handled anymore */
1673                 if (udev_exit)
1674                         continue;
1675
1676                 /* device node and rules directory inotify watch */
1677                 if (is_inotify)
1678                         handle_inotify(udev);
1679
1680                 /*
1681                  * This needs to be after the inotify handling, to make sure,
1682                  * that the ping is send back after the possibly generated
1683                  * "change" events by the inotify device node watch.
1684                  *
1685                  * A single time we may receive a client connection which we need to
1686                  * keep open to block the client. It will be closed right before we
1687                  * exit.
1688                  */
1689                 if (is_ctrl)
1690                         ctrl_conn = handle_ctrl_msg(udev_ctrl);
1691
1692                 /* rules changed, set by inotify or a HUP signal */
1693                 if (reload_config) {
1694                         struct udev_rules *rules_new;
1695
1696                         worker_kill(udev, 0);
1697                         rules_new = udev_rules_new(udev, resolve_names);
1698                         if (rules_new != NULL) {
1699                                 udev_rules_unref(rules);
1700                                 rules = rules_new;
1701                         }
1702                         reload_config = 0;
1703                 }
1704         }
1705
1706         udev_queue_export_cleanup(udev_queue_export);
1707         rc = 0;
1708 exit:
1709         if (fd_ep >= 0)
1710                 close(fd_ep);
1711         worker_list_cleanup(udev);
1712         event_queue_cleanup(udev, EVENT_UNDEF);
1713         udev_rules_unref(rules);
1714         if (fd_signal >= 0)
1715                 close(fd_signal);
1716         if (worker_watch[READ_END] >= 0)
1717                 close(worker_watch[READ_END]);
1718         if (worker_watch[WRITE_END] >= 0)
1719                 close(worker_watch[WRITE_END]);
1720         udev_monitor_unref(monitor);
1721         udev_queue_export_unref(udev_queue_export);
1722         udev_ctrl_connection_unref(ctrl_conn);
1723         udev_ctrl_unref(udev_ctrl);
1724         udev_selinux_exit(udev);
1725         udev_unref(udev);
1726         udev_log_close();
1727         return rc;
1728 }