2 * Copyright (C) 2004-2009 Kay Sievers <kay.sievers@vrfy.org>
3 * Copyright (C) 2004 Chris Friesen <chris_friesen@sympatico.ca>
4 * Copyright (C) 2009 Canonical Ltd.
5 * Copyright (C) 2009 Scott James Remnant <scott@netsplit.com>
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.
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.
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/>.
35 #include <sys/prctl.h>
36 #include <sys/socket.h>
37 #include <sys/signalfd.h>
38 #include <sys/select.h>
42 #include <sys/ioctl.h>
43 #include <sys/inotify.h>
44 #include <sys/utsname.h>
48 #define UDEVD_PRIORITY -4
49 #define UDEV_PRIORITY -2
53 static void log_fn(struct udev *udev, int priority,
54 const char *file, int line, const char *fn,
55 const char *format, va_list args)
62 vsnprintf(buf, sizeof(buf), format, args);
63 gettimeofday(&tv, &tz);
64 fprintf(stderr, "%llu.%06u [%u] %s: %s",
65 (unsigned long long) tv.tv_sec, (unsigned int) tv.tv_usec,
66 (int) getpid(), fn, buf);
68 vsyslog(priority, format, args);
72 static struct udev_rules *rules;
73 static struct udev_queue_export *udev_queue_export;
74 static struct udev_ctrl *udev_ctrl;
75 static struct udev_monitor *monitor;
76 static int worker_watch[2];
77 static pid_t settle_pid;
78 static bool stop_exec_queue;
79 static bool reload_config;
81 static int children_max;
82 static int exec_delay;
83 static sigset_t orig_sigmask;
84 static struct udev_list_node event_list;
85 static struct udev_list_node worker_list;
86 static bool udev_exit;
87 static volatile sig_atomic_t worker_exit;
97 static struct pollfd pfd[] = {
98 [FD_NETLINK] = { .events = POLLIN },
99 [FD_WORKER] = { .events = POLLIN },
100 [FD_SIGNAL] = { .events = POLLIN },
101 [FD_INOTIFY] = { .events = POLLIN },
102 [FD_CONTROL] = { .events = POLLIN },
112 struct udev_list_node node;
114 struct udev_device *dev;
115 enum event_state state;
117 unsigned long long int delaying_seqnum;
118 unsigned long long int seqnum;
121 const char *devpath_old;
126 static struct event *node_to_event(struct udev_list_node *node)
130 event = (char *)node;
131 event -= offsetof(struct event, node);
132 return (struct event *)event;
143 struct udev_list_node node;
147 struct udev_monitor *monitor;
148 enum worker_state state;
152 /* passed from worker to main process */
153 struct worker_message {
158 static struct worker *node_to_worker(struct udev_list_node *node)
162 worker = (char *)node;
163 worker -= offsetof(struct worker, node);
164 return (struct worker *)worker;
167 static void event_queue_delete(struct event *event)
169 udev_list_node_remove(&event->node);
171 /* mark as failed, if "add" event returns non-zero */
172 if (event->exitcode != 0 && strcmp(udev_device_get_action(event->dev), "remove") != 0)
173 udev_queue_export_device_failed(udev_queue_export, event->dev);
175 udev_queue_export_device_finished(udev_queue_export, event->dev);
177 info(event->udev, "seq %llu done with %i\n", udev_device_get_seqnum(event->dev), event->exitcode);
178 udev_device_unref(event->dev);
182 static void event_sig_handler(int signum)
194 static struct worker *worker_ref(struct worker *worker)
200 static void worker_unref(struct worker *worker)
203 if (worker->refcount > 0)
206 udev_list_node_remove(&worker->node);
207 udev_monitor_unref(worker->monitor);
209 info(worker->udev, "worker [%u] cleaned up\n", worker->pid);
213 static void worker_new(struct event *event)
215 struct worker *worker;
216 struct udev_monitor *worker_monitor;
218 struct sigaction act;
220 /* listen for new events */
221 worker_monitor = udev_monitor_new_from_netlink(event->udev, NULL);
222 if (worker_monitor == NULL)
224 /* allow the main daemon netlink address to send devices to the worker */
225 udev_monitor_allow_unicast_sender(worker_monitor, monitor);
226 udev_monitor_enable_receiving(worker_monitor);
228 worker = calloc(1, sizeof(struct worker));
231 /* worker + event reference */
232 worker->refcount = 2;
233 worker->udev = event->udev;
239 struct udev_device *dev;
240 struct pollfd pmon = {
241 .fd = udev_monitor_get_fd(worker_monitor),
245 udev_queue_export_unref(udev_queue_export);
246 udev_monitor_unref(monitor);
247 udev_ctrl_unref(udev_ctrl);
248 close(pfd[FD_SIGNAL].fd);
249 close(worker_watch[READ_END]);
251 udev_log_init("udevd-work");
252 setpriority(PRIO_PROCESS, 0, UDEV_PRIORITY);
254 /* set signal handlers */
255 memset(&act, 0x00, sizeof(act));
256 act.sa_handler = event_sig_handler;
257 sigemptyset (&act.sa_mask);
259 sigaction(SIGTERM, &act, NULL);
260 sigaction(SIGALRM, &act, NULL);
262 /* unblock SIGALRM */
263 sigfillset(&sigmask);
264 sigdelset(&sigmask, SIGALRM);
265 sigprocmask(SIG_SETMASK, &sigmask, NULL);
266 /* SIGTERM is unblocked in ppoll() */
267 sigdelset(&sigmask, SIGTERM);
269 /* request TERM signal if parent exits */
270 prctl(PR_SET_PDEATHSIG, SIGTERM);
276 struct udev_event *udev_event;
277 struct worker_message msg = {};
281 info(event->udev, "seq %llu running\n", udev_device_get_seqnum(dev));
282 udev_event = udev_event_new(dev);
283 if (udev_event == NULL)
286 /* set timeout to prevent hanging processes */
287 alarm(UDEV_EVENT_TIMEOUT);
290 udev_event->exec_delay = exec_delay;
292 /* apply rules, create node, symlinks */
293 err = udev_event_execute_rules(udev_event, rules);
295 /* rules may change/disable the timeout */
296 if (udev_device_get_event_timeout(dev) >= 0)
297 alarm(udev_device_get_event_timeout(dev));
300 failed = udev_event_execute_run(udev_event, &orig_sigmask);
304 /* apply/restore inotify watch */
305 if (err == 0 && udev_event->inotify_watch) {
306 udev_watch_begin(udev_event->udev, dev);
307 udev_device_update_db(dev);
310 /* send processed event back to libudev listeners */
311 udev_monitor_send_device(worker_monitor, NULL, dev);
313 /* send udevd the result of the event execution */
316 else if (failed != 0)
317 msg.exitcode = failed;
319 send(worker_watch[WRITE_END], &msg, sizeof(struct worker_message), 0);
321 info(event->udev, "seq %llu processed with %i\n", udev_device_get_seqnum(dev), err);
322 udev_event_unref(udev_event);
323 udev_device_unref(dev);
326 /* wait for more device messages or signal from udevd */
327 while (!worker_exit) {
330 fdcount = ppoll(&pmon, 1, NULL, &sigmask);
334 if (pmon.revents & POLLIN) {
335 dev = udev_monitor_receive_device(worker_monitor);
340 } while (dev != NULL);
342 udev_monitor_unref(worker_monitor);
347 udev_monitor_unref(worker_monitor);
348 event->state = EVENT_QUEUED;
350 err(event->udev, "fork of child failed: %m\n");
353 /* close monitor, but keep address around */
354 udev_monitor_disconnect(worker_monitor);
355 worker->monitor = worker_monitor;
357 worker->state = WORKER_RUNNING;
358 worker->event = event;
359 event->state = EVENT_RUNNING;
360 udev_list_node_append(&worker->node, &worker_list);
362 info(event->udev, "seq %llu forked new worker [%u]\n", udev_device_get_seqnum(event->dev), pid);
367 static void event_run(struct event *event, bool force)
369 struct udev_list_node *loop;
371 udev_list_node_foreach(loop, &worker_list) {
372 struct worker *worker = node_to_worker(loop);
375 if (worker->state != WORKER_IDLE)
378 count = udev_monitor_send_device(monitor, worker->monitor, event->dev);
380 err(event->udev, "worker [%u] did not accept message %zi (%m), kill it\n", worker->pid, count);
381 kill(worker->pid, SIGKILL);
382 worker->state = WORKER_KILLED;
386 worker->event = event;
387 worker->state = WORKER_RUNNING;
388 event->state = EVENT_RUNNING;
392 if (!force && children >= children_max) {
393 if (children_max > 1)
394 info(event->udev, "maximum number (%i) of children reached\n", children);
398 /* start new worker and pass initial device */
402 static void event_queue_insert(struct udev_device *dev)
406 event = calloc(1, sizeof(struct event));
410 event->udev = udev_device_get_udev(dev);
412 event->seqnum = udev_device_get_seqnum(dev);
413 event->devpath = udev_device_get_devpath(dev);
414 event->devpath_len = strlen(event->devpath);
415 event->devpath_old = udev_device_get_devpath_old(dev);
416 event->devnum = udev_device_get_devnum(dev);
417 event->is_block = (strcmp("block", udev_device_get_subsystem(dev)) == 0);
419 udev_queue_export_device_queued(udev_queue_export, dev);
420 info(event->udev, "seq %llu queued, '%s' '%s'\n", udev_device_get_seqnum(dev),
421 udev_device_get_action(dev), udev_device_get_subsystem(dev));
423 event->state = EVENT_QUEUED;
424 udev_list_node_append(&event->node, &event_list);
426 /* run all events with a timeout set immediately */
427 if (udev_device_get_timeout(dev) > 0) {
428 event_run(event, true);
433 static void worker_kill(struct udev *udev, int retain)
435 struct udev_list_node *loop;
438 if (children <= retain)
441 max = children - retain;
443 udev_list_node_foreach(loop, &worker_list) {
444 struct worker *worker = node_to_worker(loop);
449 if (worker->state == WORKER_KILLED)
452 worker->state = WORKER_KILLED;
453 kill(worker->pid, SIGTERM);
457 /* lookup event for identical, parent, child device */
458 static bool is_devpath_busy(struct event *event)
460 struct udev_list_node *loop;
463 /* check if queue contains events we depend on */
464 udev_list_node_foreach(loop, &event_list) {
465 struct event *loop_event = node_to_event(loop);
467 /* we already found a later event, earlier can not block us, no need to check again */
468 if (loop_event->seqnum < event->delaying_seqnum)
471 /* event we checked earlier still exists, no need to check again */
472 if (loop_event->seqnum == event->delaying_seqnum)
475 /* found ourself, no later event can block us */
476 if (loop_event->seqnum >= event->seqnum)
479 /* check major/minor */
480 if (major(event->devnum) != 0 && event->devnum == loop_event->devnum && event->is_block == loop_event->is_block)
483 /* check our old name */
484 if (event->devpath_old != NULL && strcmp(loop_event->devpath, event->devpath_old) == 0) {
485 event->delaying_seqnum = loop_event->seqnum;
489 /* compare devpath */
490 common = MIN(loop_event->devpath_len, event->devpath_len);
492 /* one devpath is contained in the other? */
493 if (memcmp(loop_event->devpath, event->devpath, common) != 0)
496 /* identical device event found */
497 if (loop_event->devpath_len == event->devpath_len) {
498 event->delaying_seqnum = loop_event->seqnum;
502 /* parent device event found */
503 if (event->devpath[common] == '/') {
504 event->delaying_seqnum = loop_event->seqnum;
508 /* child device event found */
509 if (loop_event->devpath[common] == '/') {
510 event->delaying_seqnum = loop_event->seqnum;
514 /* no matching device */
521 static void events_start(struct udev *udev)
523 struct udev_list_node *loop;
525 udev_list_node_foreach(loop, &event_list) {
526 struct event *event = node_to_event(loop);
528 if (event->state != EVENT_QUEUED)
531 /* do not start event if parent or child event is still running */
532 if (is_devpath_busy(event)) {
533 dbg(udev, "delay seq %llu (%s)\n", event->seqnum, event->devpath);
537 event_run(event, false);
541 static void worker_returned(void)
544 struct worker_message msg;
546 struct udev_list_node *loop;
548 size = recv(pfd[FD_WORKER].fd, &msg, sizeof(struct worker_message), MSG_DONTWAIT);
549 if (size != sizeof(struct worker_message))
552 /* lookup worker who sent the signal */
553 udev_list_node_foreach(loop, &worker_list) {
554 struct worker *worker = node_to_worker(loop);
556 if (worker->pid != msg.pid)
559 /* worker returned */
560 worker->event->exitcode = msg.exitcode;
561 event_queue_delete(worker->event);
562 worker->event = NULL;
563 if (worker->state != WORKER_KILLED)
564 worker->state = WORKER_IDLE;
565 worker_unref(worker);
571 /* receive the udevd message from userspace */
572 static void handle_ctrl_msg(struct udev_ctrl *uctrl)
574 struct udev *udev = udev_ctrl_get_udev(uctrl);
575 struct udev_ctrl_msg *ctrl_msg;
579 ctrl_msg = udev_ctrl_receive_msg(uctrl);
580 if (ctrl_msg == NULL)
583 i = udev_ctrl_get_set_log_level(ctrl_msg);
585 info(udev, "udevd message (SET_LOG_PRIORITY) received, log_priority=%i\n", i);
586 udev_set_log_priority(udev, i);
587 worker_kill(udev, 0);
590 if (udev_ctrl_get_stop_exec_queue(ctrl_msg) > 0) {
591 info(udev, "udevd message (STOP_EXEC_QUEUE) received\n");
592 stop_exec_queue = true;
595 if (udev_ctrl_get_start_exec_queue(ctrl_msg) > 0) {
596 info(udev, "udevd message (START_EXEC_QUEUE) received\n");
597 stop_exec_queue = false;
600 if (udev_ctrl_get_reload_rules(ctrl_msg) > 0) {
601 info(udev, "udevd message (RELOAD_RULES) received\n");
602 reload_config = true;
605 str = udev_ctrl_get_set_env(ctrl_msg);
613 val = strchr(key, '=');
617 if (val[0] == '\0') {
618 info(udev, "udevd message (ENV) received, unset '%s'\n", key);
619 udev_add_property(udev, key, NULL);
621 info(udev, "udevd message (ENV) received, set '%s=%s'\n", key, val);
622 udev_add_property(udev, key, val);
625 err(udev, "wrong key format '%s'\n", key);
629 worker_kill(udev, 0);
632 i = udev_ctrl_get_set_children_max(ctrl_msg);
634 info(udev, "udevd message (SET_MAX_CHILDREN) received, children_max=%i\n", i);
638 settle_pid = udev_ctrl_get_settle(ctrl_msg);
639 if (settle_pid > 0) {
640 info(udev, "udevd message (SETTLE) received\n");
641 kill(settle_pid, SIGUSR1);
644 udev_ctrl_msg_unref(ctrl_msg);
647 /* read inotify messages */
648 static int handle_inotify(struct udev *udev)
652 struct inotify_event *ev;
654 if ((ioctl(pfd[FD_INOTIFY].fd, FIONREAD, &nbytes) < 0) || (nbytes <= 0))
657 buf = malloc(nbytes);
659 err(udev, "error getting buffer for inotify\n");
663 nbytes = read(pfd[FD_INOTIFY].fd, buf, nbytes);
665 for (pos = 0; pos < nbytes; pos += sizeof(struct inotify_event) + ev->len) {
666 struct udev_device *dev;
668 ev = (struct inotify_event *)(buf + pos);
672 info(udev, "inotify event: %x for %s\n", ev->mask, ev->name);
673 s = strstr(ev->name, ".rules");
676 if (strlen(s) != strlen(".rules"))
678 reload_config = true;
682 dev = udev_watch_lookup(udev, ev->wd);
684 info(udev, "inotify event: %x for %s\n", ev->mask, udev_device_get_devnode(dev));
685 if (ev->mask & IN_CLOSE_WRITE) {
686 char filename[UTIL_PATH_SIZE];
689 info(udev, "device %s closed, synthesising 'change'\n", udev_device_get_devnode(dev));
690 util_strscpyl(filename, sizeof(filename), udev_device_get_syspath(dev), "/uevent", NULL);
691 fd = open(filename, O_WRONLY);
692 if (fd < 0 || write(fd, "change", 6) < 0)
693 info(udev, "error writing uevent: %m\n");
696 if (ev->mask & IN_IGNORED)
697 udev_watch_end(udev, dev);
699 udev_device_unref(dev);
708 static void handle_signal(struct udev *udev, int signo)
719 struct udev_list_node *loop, *tmp;
721 pid = waitpid(-1, &status, WNOHANG);
725 udev_list_node_foreach_safe(loop, tmp, &worker_list) {
726 struct worker *worker = node_to_worker(loop);
728 if (worker->pid != pid)
731 info(udev, "worker [%u] exit\n", pid);
732 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
733 err(udev, "worker [%u] unexpectedly returned with status 0x%04x\n", pid, status);
734 if (worker->event != NULL) {
735 err(udev, "worker [%u] failed while handling '%s'\n", pid, worker->event->devpath);
736 worker->event->exitcode = -32;
737 event_queue_delete(worker->event);
738 /* drop reference from running event */
739 worker_unref(worker);
742 worker_unref(worker);
748 reload_config = true;
753 static void static_dev_create_from_modules(struct udev *udev)
755 struct utsname kernel;
756 char modules[UTIL_PATH_SIZE];
761 util_strscpyl(modules, sizeof(modules), "/lib/modules/", kernel.release, "/modules.devname", NULL);
762 f = fopen(modules, "r");
766 while (fgets(buf, sizeof(buf), f) != NULL) {
774 char filename[UTIL_PATH_SIZE];
780 s = strchr(modname, ' ');
786 s = strchr(devname, ' ');
792 s = strchr(devno, ' ');
794 s = strchr(devno, '\n');
797 if (sscanf(devno, "%c%u:%u", &type, &maj, &min) != 3)
801 mode = 0600 | S_IFCHR;
802 else if (type == 'b')
803 mode = 0600 | S_IFBLK;
807 util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev), "/", devname, NULL);
808 util_create_path(udev, filename);
809 udev_selinux_setfscreatecon(udev, filename, mode);
810 info(udev, "mknod '%s' %c%u:%u\n", filename, type, maj, min);
811 if (mknod(filename, mode, makedev(maj, min)) < 0 && errno == EEXIST)
812 utimensat(AT_FDCWD, filename, NULL, 0);
813 udev_selinux_resetfscreatecon(udev);
819 static int copy_dir(struct udev *udev, DIR *dir_from, DIR *dir_to, int maxdepth)
823 for (dent = readdir(dir_from); dent != NULL; dent = readdir(dir_from)) {
826 if (dent->d_name[0] == '.')
828 if (fstatat(dirfd(dir_from), dent->d_name, &stats, AT_SYMLINK_NOFOLLOW) != 0)
831 if (S_ISBLK(stats.st_mode) || S_ISCHR(stats.st_mode)) {
832 udev_selinux_setfscreateconat(udev, dirfd(dir_to), dent->d_name, stats.st_mode & 0777);
833 if (mknodat(dirfd(dir_to), dent->d_name, stats.st_mode, stats.st_rdev) == 0) {
834 fchmodat(dirfd(dir_to), dent->d_name, stats.st_mode & 0777, 0);
835 fchownat(dirfd(dir_to), dent->d_name, stats.st_uid, stats.st_gid, 0);
837 utimensat(dirfd(dir_to), dent->d_name, NULL, 0);
839 udev_selinux_resetfscreatecon(udev);
840 } else if (S_ISLNK(stats.st_mode)) {
841 char target[UTIL_PATH_SIZE];
844 len = readlinkat(dirfd(dir_from), dent->d_name, target, sizeof(target));
845 if (len <= 0 || len == (ssize_t)sizeof(target))
848 udev_selinux_setfscreateconat(udev, dirfd(dir_to), dent->d_name, S_IFLNK);
849 if (symlinkat(target, dirfd(dir_to), dent->d_name) < 0 && errno == EEXIST)
850 utimensat(dirfd(dir_to), dent->d_name, NULL, AT_SYMLINK_NOFOLLOW);
851 udev_selinux_resetfscreatecon(udev);
852 } else if (S_ISDIR(stats.st_mode)) {
853 DIR *dir2_from, *dir2_to;
858 udev_selinux_setfscreateconat(udev, dirfd(dir_to), dent->d_name, S_IFDIR|0755);
859 mkdirat(dirfd(dir_to), dent->d_name, 0755);
860 udev_selinux_resetfscreatecon(udev);
862 dir2_to = fdopendir(openat(dirfd(dir_to), dent->d_name, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC));
866 dir2_from = fdopendir(openat(dirfd(dir_from), dent->d_name, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC));
867 if (dir2_from == NULL) {
872 copy_dir(udev, dir2_from, dir2_to, maxdepth-1);
882 static void static_dev_create_links(struct udev *udev, DIR *dir)
888 static const struct stdlinks stdlinks[] = {
889 { "core", "/proc/kcore" },
890 { "fd", "/proc/self/fd" },
891 { "stdin", "/proc/self/fd/0" },
892 { "stdout", "/proc/self/fd/1" },
893 { "stderr", "/proc/self/fd/2" },
897 for (i = 0; i < ARRAY_SIZE(stdlinks); i++) {
898 udev_selinux_setfscreateconat(udev, dirfd(dir), stdlinks[i].link, S_IFLNK);
899 if (symlinkat(stdlinks[i].target, dirfd(dir), stdlinks[i].link) < 0 && errno == EEXIST)
900 utimensat(dirfd(dir), stdlinks[i].link, NULL, AT_SYMLINK_NOFOLLOW);
901 udev_selinux_resetfscreatecon(udev);
905 static void static_dev_create_from_devices(struct udev *udev, DIR *dir)
909 dir_from = opendir(LIBEXECDIR "/devices");
910 if (dir_from == NULL)
912 copy_dir(udev, dir_from, dir, 8);
916 static void static_dev_create(struct udev *udev)
920 dir = opendir(udev_get_dev_path(udev));
924 static_dev_create_links(udev, dir);
925 static_dev_create_from_devices(udev, dir);
930 static int mem_size_mb(void)
934 long int memsize = -1;
936 f = fopen("/proc/meminfo", "r");
940 while (fgets(buf, sizeof(buf), f) != NULL) {
943 if (sscanf(buf, "MemTotal: %ld kB", &value) == 1) {
944 memsize = value / 1024;
953 int main(int argc, char *argv[])
959 int daemonize = false;
960 int resolve_names = 1;
961 static const struct option options[] = {
962 { "daemon", no_argument, NULL, 'd' },
963 { "debug", no_argument, NULL, 'D' },
964 { "children-max", required_argument, NULL, 'c' },
965 { "exec-delay", required_argument, NULL, 'e' },
966 { "resolve-names", required_argument, NULL, 'N' },
967 { "help", no_argument, NULL, 'h' },
968 { "version", no_argument, NULL, 'V' },
977 udev_log_init("udevd");
978 udev_set_log_fn(udev, log_fn);
979 info(udev, "version %s\n", VERSION);
980 udev_selinux_init(udev);
985 option = getopt_long(argc, argv, "cdeDthV", options, NULL);
994 children_max = strtoul(optarg, NULL, 0);
997 exec_delay = strtoul(optarg, NULL, 0);
1001 if (udev_get_log_priority(udev) < LOG_INFO)
1002 udev_set_log_priority(udev, LOG_INFO);
1005 if (strcmp (optarg, "early") == 0) {
1007 } else if (strcmp (optarg, "late") == 0) {
1009 } else if (strcmp (optarg, "never") == 0) {
1012 fprintf(stderr, "resolve-names must be early, late or never\n");
1013 err(udev, "resolve-names must be early, late or never\n");
1018 printf("Usage: udevd OPTIONS\n"
1021 " --children-max=<maximum number of workers>\n"
1022 " --exec-delay=<seconds to wait before executing RUN=>\n"
1023 " --resolve-names=early|late|never\n"
1029 printf("%s\n", VERSION);
1037 * read the kernel commandline, in case we need to get into debug mode
1038 * udev.log-priority=<level> syslog priority
1039 * udev.children-max=<number of workers> events are fully serialized if set to 1
1042 f = fopen("/proc/cmdline", "r");
1046 if (fgets(cmdline, sizeof(cmdline), f) != NULL) {
1049 pos = strstr(cmdline, "udev.log-priority=");
1051 pos += strlen("udev.log-priority=");
1052 udev_set_log_priority(udev, util_log_priority(pos));
1055 pos = strstr(cmdline, "udev.children-max=");
1057 pos += strlen("udev.children-max=");
1058 children_max = strtoul(pos, NULL, 0);
1061 pos = strstr(cmdline, "udev.exec-delay=");
1063 pos += strlen("udev.exec-delay=");
1064 exec_delay = strtoul(pos, NULL, 0);
1070 if (getuid() != 0) {
1071 fprintf(stderr, "root privileges required\n");
1072 err(udev, "root privileges required\n");
1076 /* set umask before creating any file/directory */
1080 /* before opening new files, make sure std{in,out,err} fds are in a sane state */
1081 fd = open("/dev/null", O_RDWR);
1083 fprintf(stderr, "cannot open /dev/null\n");
1084 err(udev, "cannot open /dev/null\n");
1086 if (write(STDOUT_FILENO, 0, 0) < 0)
1087 dup2(fd, STDOUT_FILENO);
1088 if (write(STDERR_FILENO, 0, 0) < 0)
1089 dup2(fd, STDERR_FILENO);
1091 udev_ctrl = udev_ctrl_new_from_socket(udev, UDEV_CTRL_SOCK_PATH);
1092 if (udev_ctrl == NULL) {
1093 fprintf(stderr, "error initializing control socket");
1094 err(udev, "error initializing udevd socket");
1098 if (udev_ctrl_enable_receiving(udev_ctrl) < 0) {
1099 fprintf(stderr, "error binding control socket, seems udevd is already running\n");
1100 err(udev, "error binding control socket, seems udevd is already running\n");
1104 pfd[FD_CONTROL].fd = udev_ctrl_get_fd(udev_ctrl);
1106 monitor = udev_monitor_new_from_netlink(udev, "kernel");
1107 if (monitor == NULL || udev_monitor_enable_receiving(monitor) < 0) {
1108 fprintf(stderr, "error initializing netlink socket\n");
1109 err(udev, "error initializing netlink socket\n");
1113 udev_monitor_set_receive_buffer_size(monitor, 128*1024*1024);
1114 pfd[FD_NETLINK].fd = udev_monitor_get_fd(monitor);
1116 pfd[FD_INOTIFY].fd = udev_watch_init(udev);
1117 if (pfd[FD_INOTIFY].fd < 0) {
1118 fprintf(stderr, "error initializing inotify\n");
1119 err(udev, "error initializing inotify\n");
1124 if (udev_get_rules_path(udev) != NULL) {
1125 inotify_add_watch(pfd[FD_INOTIFY].fd, udev_get_rules_path(udev),
1126 IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
1128 char filename[UTIL_PATH_SIZE];
1129 struct stat statbuf;
1131 inotify_add_watch(pfd[FD_INOTIFY].fd, LIBEXECDIR "/rules.d",
1132 IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
1133 inotify_add_watch(pfd[FD_INOTIFY].fd, SYSCONFDIR "/udev/rules.d",
1134 IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
1136 /* watch dynamic rules directory */
1137 util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev), "/.udev/rules.d", NULL);
1138 if (stat(filename, &statbuf) != 0) {
1139 util_create_path(udev, filename);
1140 udev_selinux_setfscreatecon(udev, filename, S_IFDIR|0755);
1141 mkdir(filename, 0755);
1142 udev_selinux_resetfscreatecon(udev);
1144 inotify_add_watch(pfd[FD_INOTIFY].fd, filename,
1145 IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
1147 udev_watch_restore(udev);
1149 /* block and listen to all signals on signalfd */
1151 sigprocmask(SIG_SETMASK, &mask, &orig_sigmask);
1152 pfd[FD_SIGNAL].fd = signalfd(-1, &mask, 0);
1153 if (pfd[FD_SIGNAL].fd < 0) {
1154 fprintf(stderr, "error getting signalfd\n");
1155 err(udev, "error getting signalfd\n");
1160 /* unnamed socket from workers to the main daemon */
1161 if (socketpair(AF_LOCAL, SOCK_DGRAM|SOCK_CLOEXEC, 0, worker_watch) < 0) {
1162 fprintf(stderr, "error getting socketpair\n");
1163 err(udev, "error getting socketpair\n");
1167 pfd[FD_WORKER].fd = worker_watch[READ_END];
1169 rules = udev_rules_new(udev, resolve_names);
1170 if (rules == NULL) {
1171 err(udev, "error reading rules\n");
1175 udev_queue_export = udev_queue_export_new(udev);
1176 if (udev_queue_export == NULL) {
1177 err(udev, "error creating queue file\n");
1182 dup2(fd, STDIN_FILENO);
1183 dup2(fd, STDOUT_FILENO);
1184 dup2(fd, STDERR_FILENO);
1186 if (fd > STDERR_FILENO)
1197 err(udev, "fork of daemon failed: %m\n");
1206 /* set scheduling priority for the main daemon process */
1207 setpriority(PRIO_PROCESS, 0, UDEVD_PRIORITY);
1211 f = fopen("/dev/kmsg", "w");
1213 fprintf(f, "<6>udev: starting version " VERSION "\n");
1217 /* OOM_DISABLE == -17 */
1218 fd = open("/proc/self/oom_adj", O_RDWR);
1220 err(udev, "error disabling OOM: %m\n");
1222 write(fd, "-17", 3);
1226 if (children_max <= 0) {
1227 int memsize = mem_size_mb();
1229 /* set value depending on the amount of RAM */
1231 children_max = 128 + (memsize / 8);
1235 info(udev, "set children_max to %u\n", children_max);
1237 static_dev_create(udev);
1238 static_dev_create_from_modules(udev);
1239 udev_rules_apply_static_dev_perms(rules);
1241 udev_list_init(&event_list);
1242 udev_list_init(&worker_list);
1244 while (!udev_exit) {
1248 /* set timeout to kill idle workers */
1249 if (udev_list_is_empty(&event_list) && children > 2)
1253 /* wait for events */
1254 fdcount = poll(pfd, ARRAY_SIZE(pfd), timeout);
1258 /* timeout - kill idle workers */
1260 worker_kill(udev, 2);
1262 /* event has finished */
1263 if (pfd[FD_WORKER].revents & POLLIN)
1266 /* get kernel uevent */
1267 if (pfd[FD_NETLINK].revents & POLLIN) {
1268 struct udev_device *dev;
1270 dev = udev_monitor_receive_device(monitor);
1272 event_queue_insert(dev);
1274 udev_device_unref(dev);
1277 /* start new events */
1278 if (!udev_list_is_empty(&event_list) && !stop_exec_queue)
1282 if (pfd[FD_SIGNAL].revents & POLLIN) {
1283 struct signalfd_siginfo fdsi;
1286 size = read(pfd[FD_SIGNAL].fd, &fdsi, sizeof(struct signalfd_siginfo));
1287 if (size == sizeof(struct signalfd_siginfo))
1288 handle_signal(udev, fdsi.ssi_signo);
1291 /* device node and rules directory inotify watch */
1292 if (pfd[FD_INOTIFY].revents & POLLIN)
1293 handle_inotify(udev);
1296 * get control message
1298 * This needs to be after the inotify handling, to make sure,
1299 * that the settle signal is send back after the possibly generated
1300 * "change" events by the inotify device node watch.
1302 if (pfd[FD_CONTROL].revents & POLLIN)
1303 handle_ctrl_msg(udev_ctrl);
1305 /* rules changed, set by inotify or a HUP signal */
1306 if (reload_config) {
1307 struct udev_rules *rules_new;
1309 worker_kill(udev, 0);
1310 rules_new = udev_rules_new(udev, resolve_names);
1311 if (rules_new != NULL) {
1312 udev_rules_unref(rules);
1319 udev_queue_export_cleanup(udev_queue_export);
1322 udev_queue_export_unref(udev_queue_export);
1323 udev_rules_unref(rules);
1324 udev_ctrl_unref(udev_ctrl);
1325 if (pfd[FD_SIGNAL].fd >= 0)
1326 close(pfd[FD_SIGNAL].fd);
1327 if (worker_watch[READ_END] >= 0)
1328 close(worker_watch[READ_END]);
1329 if (worker_watch[WRITE_END] >= 0)
1330 close(worker_watch[WRITE_END]);
1331 udev_monitor_unref(monitor);
1332 udev_selinux_exit(udev);