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 bool debug_trace;
73 static struct udev_rules *rules;
74 static struct udev_queue_export *udev_queue_export;
75 static struct udev_ctrl *udev_ctrl;
76 static struct udev_monitor *monitor;
77 static int worker_watch[2];
78 static pid_t settle_pid;
79 static bool stop_exec_queue;
80 static bool reload_config;
81 static int max_childs;
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);
289 /* apply rules, create node, symlinks */
290 err = udev_event_execute_rules(udev_event, rules);
292 /* rules may change/disable the timeout */
293 if (udev_device_get_event_timeout(dev) >= 0)
294 alarm(udev_device_get_event_timeout(dev));
297 failed = udev_event_execute_run(udev_event, &orig_sigmask);
301 /* apply/restore inotify watch */
302 if (err == 0 && udev_event->inotify_watch) {
303 udev_watch_begin(udev_event->udev, dev);
304 udev_device_update_db(dev);
307 /* send processed event back to libudev listeners */
308 udev_monitor_send_device(worker_monitor, NULL, dev);
310 /* send udevd the result of the event execution */
313 else if (failed != 0)
314 msg.exitcode = failed;
316 send(worker_watch[WRITE_END], &msg, sizeof(struct worker_message), 0);
318 info(event->udev, "seq %llu processed with %i\n", udev_device_get_seqnum(dev), err);
319 udev_event_unref(udev_event);
320 udev_device_unref(dev);
323 /* wait for more device messages or signal from udevd */
324 while (!worker_exit) {
327 fdcount = ppoll(&pmon, 1, NULL, &sigmask);
331 if (pmon.revents & POLLIN) {
332 dev = udev_monitor_receive_device(worker_monitor);
337 } while (dev != NULL);
339 udev_monitor_unref(worker_monitor);
344 udev_monitor_unref(worker_monitor);
345 event->state = EVENT_QUEUED;
347 err(event->udev, "fork of child failed: %m\n");
350 /* close monitor, but keep address around */
351 udev_monitor_disconnect(worker_monitor);
352 worker->monitor = worker_monitor;
354 worker->state = WORKER_RUNNING;
355 worker->event = event;
356 event->state = EVENT_RUNNING;
357 udev_list_node_append(&worker->node, &worker_list);
359 info(event->udev, "seq %llu forked new worker [%u]\n", udev_device_get_seqnum(event->dev), pid);
364 static void event_run(struct event *event, bool force)
366 struct udev_list_node *loop;
368 udev_list_node_foreach(loop, &worker_list) {
369 struct worker *worker = node_to_worker(loop);
372 if (worker->state != WORKER_IDLE)
375 count = udev_monitor_send_device(monitor, worker->monitor, event->dev);
377 err(event->udev, "worker [%u] did not accept message %zi (%m), kill it\n", worker->pid, count);
378 kill(worker->pid, SIGKILL);
379 worker->state = WORKER_KILLED;
383 worker->event = event;
384 worker->state = WORKER_RUNNING;
385 event->state = EVENT_RUNNING;
389 if (!force && childs >= max_childs) {
390 info(event->udev, "maximum number (%i) of childs reached\n", childs);
394 /* start new worker and pass initial device */
398 static void event_queue_insert(struct udev_device *dev)
402 event = calloc(1, sizeof(struct event));
406 event->udev = udev_device_get_udev(dev);
408 event->seqnum = udev_device_get_seqnum(dev);
409 event->devpath = udev_device_get_devpath(dev);
410 event->devpath_len = strlen(event->devpath);
411 event->devpath_old = udev_device_get_devpath_old(dev);
412 event->devnum = udev_device_get_devnum(dev);
413 event->is_block = (strcmp("block", udev_device_get_subsystem(dev)) == 0);
415 udev_queue_export_device_queued(udev_queue_export, dev);
416 info(event->udev, "seq %llu queued, '%s' '%s'\n", udev_device_get_seqnum(dev),
417 udev_device_get_action(dev), udev_device_get_subsystem(dev));
419 event->state = EVENT_QUEUED;
420 udev_list_node_append(&event->node, &event_list);
422 /* run all events with a timeout set immediately */
423 if (udev_device_get_timeout(dev) > 0) {
424 event_run(event, true);
429 static void worker_kill(struct udev *udev, int retain)
431 struct udev_list_node *loop;
434 if (childs <= retain)
437 max = childs - retain;
439 udev_list_node_foreach(loop, &worker_list) {
440 struct worker *worker = node_to_worker(loop);
445 if (worker->state == WORKER_KILLED)
448 worker->state = WORKER_KILLED;
449 kill(worker->pid, SIGTERM);
453 /* lookup event for identical, parent, child device */
454 static bool is_devpath_busy(struct event *event)
456 struct udev_list_node *loop;
459 /* check if queue contains events we depend on */
460 udev_list_node_foreach(loop, &event_list) {
461 struct event *loop_event = node_to_event(loop);
463 /* we already found a later event, earlier can not block us, no need to check again */
464 if (loop_event->seqnum < event->delaying_seqnum)
467 /* event we checked earlier still exists, no need to check again */
468 if (loop_event->seqnum == event->delaying_seqnum)
471 /* found ourself, no later event can block us */
472 if (loop_event->seqnum >= event->seqnum)
475 /* check major/minor */
476 if (major(event->devnum) != 0 && event->devnum == loop_event->devnum && event->is_block == loop_event->is_block)
479 /* check our old name */
480 if (event->devpath_old != NULL && strcmp(loop_event->devpath, event->devpath_old) == 0) {
481 event->delaying_seqnum = loop_event->seqnum;
485 /* compare devpath */
486 common = MIN(loop_event->devpath_len, event->devpath_len);
488 /* one devpath is contained in the other? */
489 if (memcmp(loop_event->devpath, event->devpath, common) != 0)
492 /* identical device event found */
493 if (loop_event->devpath_len == event->devpath_len) {
494 event->delaying_seqnum = loop_event->seqnum;
498 /* parent device event found */
499 if (event->devpath[common] == '/') {
500 event->delaying_seqnum = loop_event->seqnum;
504 /* child device event found */
505 if (loop_event->devpath[common] == '/') {
506 event->delaying_seqnum = loop_event->seqnum;
510 /* no matching device */
517 static void events_start(struct udev *udev)
519 struct udev_list_node *loop;
521 udev_list_node_foreach(loop, &event_list) {
522 struct event *event = node_to_event(loop);
524 if (event->state != EVENT_QUEUED)
527 /* do not start event if parent or child event is still running */
528 if (is_devpath_busy(event)) {
529 dbg(udev, "delay seq %llu (%s)\n", event->seqnum, event->devpath);
533 event_run(event, false);
537 static void worker_returned(void)
540 struct worker_message msg;
542 struct udev_list_node *loop;
544 size = recv(pfd[FD_WORKER].fd, &msg, sizeof(struct worker_message), MSG_DONTWAIT);
545 if (size != sizeof(struct worker_message))
548 /* lookup worker who sent the signal */
549 udev_list_node_foreach(loop, &worker_list) {
550 struct worker *worker = node_to_worker(loop);
552 if (worker->pid != msg.pid)
555 /* worker returned */
556 worker->event->exitcode = msg.exitcode;
557 event_queue_delete(worker->event);
558 worker->event = NULL;
559 if (worker->state != WORKER_KILLED)
560 worker->state = WORKER_IDLE;
561 worker_unref(worker);
567 /* receive the udevd message from userspace */
568 static void handle_ctrl_msg(struct udev_ctrl *uctrl)
570 struct udev *udev = udev_ctrl_get_udev(uctrl);
571 struct udev_ctrl_msg *ctrl_msg;
575 ctrl_msg = udev_ctrl_receive_msg(uctrl);
576 if (ctrl_msg == NULL)
579 i = udev_ctrl_get_set_log_level(ctrl_msg);
581 info(udev, "udevd message (SET_LOG_PRIORITY) received, log_priority=%i\n", i);
582 udev_set_log_priority(udev, i);
583 worker_kill(udev, 0);
586 if (udev_ctrl_get_stop_exec_queue(ctrl_msg) > 0) {
587 info(udev, "udevd message (STOP_EXEC_QUEUE) received\n");
588 stop_exec_queue = true;
591 if (udev_ctrl_get_start_exec_queue(ctrl_msg) > 0) {
592 info(udev, "udevd message (START_EXEC_QUEUE) received\n");
593 stop_exec_queue = false;
596 if (udev_ctrl_get_reload_rules(ctrl_msg) > 0) {
597 info(udev, "udevd message (RELOAD_RULES) received\n");
598 reload_config = true;
601 str = udev_ctrl_get_set_env(ctrl_msg);
609 val = strchr(key, '=');
613 if (val[0] == '\0') {
614 info(udev, "udevd message (ENV) received, unset '%s'\n", key);
615 udev_add_property(udev, key, NULL);
617 info(udev, "udevd message (ENV) received, set '%s=%s'\n", key, val);
618 udev_add_property(udev, key, val);
621 err(udev, "wrong key format '%s'\n", key);
625 worker_kill(udev, 0);
628 i = udev_ctrl_get_set_max_childs(ctrl_msg);
630 info(udev, "udevd message (SET_MAX_CHILDS) received, max_childs=%i\n", i);
634 settle_pid = udev_ctrl_get_settle(ctrl_msg);
635 if (settle_pid > 0) {
636 info(udev, "udevd message (SETTLE) received\n");
637 kill(settle_pid, SIGUSR1);
640 udev_ctrl_msg_unref(ctrl_msg);
643 /* read inotify messages */
644 static int handle_inotify(struct udev *udev)
648 struct inotify_event *ev;
650 if ((ioctl(pfd[FD_INOTIFY].fd, FIONREAD, &nbytes) < 0) || (nbytes <= 0))
653 buf = malloc(nbytes);
655 err(udev, "error getting buffer for inotify\n");
659 nbytes = read(pfd[FD_INOTIFY].fd, buf, nbytes);
661 for (pos = 0; pos < nbytes; pos += sizeof(struct inotify_event) + ev->len) {
662 struct udev_device *dev;
664 ev = (struct inotify_event *)(buf + pos);
668 info(udev, "inotify event: %x for %s\n", ev->mask, ev->name);
669 s = strstr(ev->name, ".rules");
672 if (strlen(s) != strlen(".rules"))
674 reload_config = true;
678 dev = udev_watch_lookup(udev, ev->wd);
680 info(udev, "inotify event: %x for %s\n", ev->mask, udev_device_get_devnode(dev));
681 if (ev->mask & IN_CLOSE_WRITE) {
682 char filename[UTIL_PATH_SIZE];
685 info(udev, "device %s closed, synthesising 'change'\n", udev_device_get_devnode(dev));
686 util_strscpyl(filename, sizeof(filename), udev_device_get_syspath(dev), "/uevent", NULL);
687 fd = open(filename, O_WRONLY);
688 if (fd < 0 || write(fd, "change", 6) < 0)
689 info(udev, "error writing uevent: %m\n");
692 if (ev->mask & IN_IGNORED)
693 udev_watch_end(udev, dev);
695 udev_device_unref(dev);
704 static void handle_signal(struct udev *udev, int signo)
715 struct udev_list_node *loop, *tmp;
717 pid = waitpid(-1, &status, WNOHANG);
721 udev_list_node_foreach_safe(loop, tmp, &worker_list) {
722 struct worker *worker = node_to_worker(loop);
724 if (worker->pid != pid)
727 info(udev, "worker [%u] exit\n", pid);
728 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
729 err(udev, "worker [%u] unexpectedly returned with status 0x%04x\n", pid, status);
730 if (worker->event != NULL) {
731 err(udev, "worker [%u] failed while handling '%s'\n", pid, worker->event->devpath);
732 worker->event->exitcode = -32;
733 event_queue_delete(worker->event);
734 /* drop reference from running event */
735 worker_unref(worker);
738 worker_unref(worker);
744 reload_config = true;
749 static void static_dev_create_from_modules(struct udev *udev)
751 struct utsname kernel;
752 char modules[UTIL_PATH_SIZE];
757 util_strscpyl(modules, sizeof(modules), "/lib/modules/", kernel.release, "/modules.devname", NULL);
758 f = fopen(modules, "r");
762 while (fgets(buf, sizeof(buf), f) != NULL) {
770 char filename[UTIL_PATH_SIZE];
776 s = strchr(modname, ' ');
782 s = strchr(devname, ' ');
788 s = strchr(devno, ' ');
790 s = strchr(devno, '\n');
793 if (sscanf(devno, "%c%u:%u", &type, &maj, &min) != 3)
797 mode = 0600 | S_IFCHR;
798 else if (type == 'b')
799 mode = 0600 | S_IFBLK;
803 util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev), "/", devname, NULL);
804 util_create_path(udev, filename);
805 udev_selinux_setfscreatecon(udev, filename, mode);
806 info(udev, "mknod '%s' %c%u:%u\n", filename, type, maj, min);
807 if (mknod(filename, mode, makedev(maj, min)) < 0 && errno == EEXIST)
808 utimensat(AT_FDCWD, filename, NULL, 0);
809 udev_selinux_resetfscreatecon(udev);
815 static int copy_dir(struct udev *udev, DIR *dir_from, DIR *dir_to, int maxdepth)
819 for (dent = readdir(dir_from); dent != NULL; dent = readdir(dir_from)) {
822 if (dent->d_name[0] == '.')
824 if (fstatat(dirfd(dir_from), dent->d_name, &stats, AT_SYMLINK_NOFOLLOW) != 0)
827 if (S_ISBLK(stats.st_mode) || S_ISCHR(stats.st_mode)) {
828 udev_selinux_setfscreateconat(udev, dirfd(dir_to), dent->d_name, stats.st_mode & 0777);
829 if (mknodat(dirfd(dir_to), dent->d_name, stats.st_mode, stats.st_rdev) == 0) {
830 fchmodat(dirfd(dir_to), dent->d_name, stats.st_mode & 0777, 0);
831 fchownat(dirfd(dir_to), dent->d_name, stats.st_uid, stats.st_gid, 0);
833 utimensat(dirfd(dir_to), dent->d_name, NULL, 0);
835 udev_selinux_resetfscreatecon(udev);
836 } else if (S_ISLNK(stats.st_mode)) {
837 char target[UTIL_PATH_SIZE];
840 len = readlinkat(dirfd(dir_from), dent->d_name, target, sizeof(target));
841 if (len <= 0 || len == (ssize_t)sizeof(target))
844 udev_selinux_setfscreateconat(udev, dirfd(dir_to), dent->d_name, S_IFLNK);
845 if (symlinkat(target, dirfd(dir_to), dent->d_name) < 0 && errno == EEXIST)
846 utimensat(dirfd(dir_to), dent->d_name, NULL, AT_SYMLINK_NOFOLLOW);
847 udev_selinux_resetfscreatecon(udev);
848 } else if (S_ISDIR(stats.st_mode)) {
849 DIR *dir2_from, *dir2_to;
854 udev_selinux_setfscreateconat(udev, dirfd(dir_to), dent->d_name, S_IFDIR|0755);
855 mkdirat(dirfd(dir_to), dent->d_name, 0755);
856 udev_selinux_resetfscreatecon(udev);
858 dir2_to = fdopendir(openat(dirfd(dir_to), dent->d_name, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC));
862 dir2_from = fdopendir(openat(dirfd(dir_from), dent->d_name, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC));
863 if (dir2_from == NULL) {
868 copy_dir(udev, dir2_from, dir2_to, maxdepth-1);
878 static void static_dev_create_links(struct udev *udev, DIR *dir)
884 static const struct stdlinks stdlinks[] = {
885 { "core", "/proc/kcore" },
886 { "fd", "/proc/self/fd" },
887 { "stdin", "/proc/self/fd/0" },
888 { "stdout", "/proc/self/fd/1" },
889 { "stderr", "/proc/self/fd/2" },
893 for (i = 0; i < ARRAY_SIZE(stdlinks); i++) {
894 udev_selinux_setfscreateconat(udev, dirfd(dir), stdlinks[i].link, S_IFLNK);
895 if (symlinkat(stdlinks[i].target, dirfd(dir), stdlinks[i].link) < 0 && errno == EEXIST)
896 utimensat(dirfd(dir), stdlinks[i].link, NULL, AT_SYMLINK_NOFOLLOW);
897 udev_selinux_resetfscreatecon(udev);
901 static void static_dev_create_from_devices(struct udev *udev, DIR *dir)
905 dir_from = opendir(LIBEXECDIR "/devices");
906 if (dir_from == NULL)
908 copy_dir(udev, dir_from, dir, 8);
912 static void static_dev_create(struct udev *udev)
916 dir = opendir(udev_get_dev_path(udev));
920 static_dev_create_links(udev, dir);
921 static_dev_create_from_devices(udev, dir);
926 static int mem_size_mb(void)
930 long int memsize = -1;
932 f = fopen("/proc/meminfo", "r");
936 while (fgets(buf, sizeof(buf), f) != NULL) {
939 if (sscanf(buf, "MemTotal: %ld kB", &value) == 1) {
940 memsize = value / 1024;
949 int main(int argc, char *argv[])
956 int daemonize = false;
957 int resolve_names = 1;
958 static const struct option options[] = {
959 { "daemon", no_argument, NULL, 'd' },
960 { "debug-trace", no_argument, NULL, 't' },
961 { "debug", no_argument, NULL, 'D' },
962 { "help", no_argument, NULL, 'h' },
963 { "version", no_argument, NULL, 'V' },
964 { "resolve-names", required_argument, NULL, 'N' },
973 udev_log_init("udevd");
974 udev_set_log_fn(udev, log_fn);
975 info(udev, "version %s\n", VERSION);
976 udev_selinux_init(udev);
981 option = getopt_long(argc, argv, "dDthV", options, NULL);
994 if (udev_get_log_priority(udev) < LOG_INFO)
995 udev_set_log_priority(udev, LOG_INFO);
998 if (strcmp (optarg, "early") == 0) {
1000 } else if (strcmp (optarg, "late") == 0) {
1002 } else if (strcmp (optarg, "never") == 0) {
1005 fprintf(stderr, "resolve-names must be early, late or never\n");
1006 err(udev, "resolve-names must be early, late or never\n");
1011 printf("Usage: udevd [--help] [--daemon] [--debug-trace] [--debug] "
1012 "[--resolve-names=early|late|never] [--version]\n");
1015 printf("%s\n", VERSION);
1022 if (getuid() != 0) {
1023 fprintf(stderr, "root privileges required\n");
1024 err(udev, "root privileges required\n");
1028 /* make sure std{in,out,err} fd's are in a sane state */
1029 fd = open("/dev/null", O_RDWR);
1031 fprintf(stderr, "cannot open /dev/null\n");
1032 err(udev, "cannot open /dev/null\n");
1034 if (write(STDOUT_FILENO, 0, 0) < 0)
1035 dup2(fd, STDOUT_FILENO);
1036 if (write(STDERR_FILENO, 0, 0) < 0)
1037 dup2(fd, STDERR_FILENO);
1039 /* init control socket, bind() ensures, that only one udevd instance is running */
1040 udev_ctrl = udev_ctrl_new_from_socket(udev, UDEV_CTRL_SOCK_PATH);
1041 if (udev_ctrl == NULL) {
1042 fprintf(stderr, "error initializing control socket");
1043 err(udev, "error initializing udevd socket");
1047 if (udev_ctrl_enable_receiving(udev_ctrl) < 0) {
1048 fprintf(stderr, "error binding control socket, seems udevd is already running\n");
1049 err(udev, "error binding control socket, seems udevd is already running\n");
1053 pfd[FD_CONTROL].fd = udev_ctrl_get_fd(udev_ctrl);
1055 monitor = udev_monitor_new_from_netlink(udev, "kernel");
1056 if (monitor == NULL || udev_monitor_enable_receiving(monitor) < 0) {
1057 fprintf(stderr, "error initializing netlink socket\n");
1058 err(udev, "error initializing netlink socket\n");
1062 udev_monitor_set_receive_buffer_size(monitor, 128*1024*1024);
1063 pfd[FD_NETLINK].fd = udev_monitor_get_fd(monitor);
1065 pfd[FD_INOTIFY].fd = udev_watch_init(udev);
1066 if (pfd[FD_INOTIFY].fd < 0) {
1067 fprintf(stderr, "error initializing inotify\n");
1068 err(udev, "error initializing inotify\n");
1073 if (udev_get_rules_path(udev) != NULL) {
1074 inotify_add_watch(pfd[FD_INOTIFY].fd, udev_get_rules_path(udev),
1075 IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
1077 char filename[UTIL_PATH_SIZE];
1078 struct stat statbuf;
1080 inotify_add_watch(pfd[FD_INOTIFY].fd, LIBEXECDIR "/rules.d",
1081 IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
1082 inotify_add_watch(pfd[FD_INOTIFY].fd, SYSCONFDIR "/udev/rules.d",
1083 IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
1085 /* watch dynamic rules directory */
1086 util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev), "/.udev/rules.d", NULL);
1087 if (stat(filename, &statbuf) != 0) {
1088 util_create_path(udev, filename);
1089 udev_selinux_setfscreatecon(udev, filename, S_IFDIR|0755);
1090 mkdir(filename, 0755);
1091 udev_selinux_resetfscreatecon(udev);
1093 inotify_add_watch(pfd[FD_INOTIFY].fd, filename,
1094 IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
1096 udev_watch_restore(udev);
1098 /* block and listen to all signals on signalfd */
1100 sigprocmask(SIG_SETMASK, &mask, &orig_sigmask);
1101 pfd[FD_SIGNAL].fd = signalfd(-1, &mask, 0);
1102 if (pfd[FD_SIGNAL].fd < 0) {
1103 fprintf(stderr, "error getting signalfd\n");
1104 err(udev, "error getting signalfd\n");
1109 /* unnamed socket from workers to the main daemon */
1110 if (socketpair(AF_LOCAL, SOCK_DGRAM|SOCK_CLOEXEC, 0, worker_watch) < 0) {
1111 fprintf(stderr, "error getting socketpair\n");
1112 err(udev, "error getting socketpair\n");
1116 pfd[FD_WORKER].fd = worker_watch[READ_END];
1118 rules = udev_rules_new(udev, resolve_names);
1119 if (rules == NULL) {
1120 err(udev, "error reading rules\n");
1124 udev_queue_export = udev_queue_export_new(udev);
1125 if (udev_queue_export == NULL) {
1126 err(udev, "error creating queue file\n");
1138 err(udev, "fork of daemon failed: %m\n");
1147 f = fopen("/dev/kmsg", "w");
1149 fprintf(f, "<6>udev: starting version " VERSION "\n");
1153 /* redirect std{out,err} */
1154 if (!debug && !debug_trace) {
1155 dup2(fd, STDIN_FILENO);
1156 dup2(fd, STDOUT_FILENO);
1157 dup2(fd, STDERR_FILENO);
1159 if (fd > STDERR_FILENO)
1162 /* set scheduling priority for the daemon */
1163 setpriority(PRIO_PROCESS, 0, UDEVD_PRIORITY);
1169 /* OOM_DISABLE == -17 */
1170 fd = open("/proc/self/oom_adj", O_RDWR);
1172 err(udev, "error disabling OOM: %m\n");
1174 write(fd, "-17", 3);
1178 /* in trace mode run one event after the other */
1182 int memsize = mem_size_mb();
1185 max_childs = 128 + (memsize / 8);
1190 /* possibly overwrite maximum limit of executed events */
1191 value = getenv("UDEVD_MAX_CHILDS");
1193 max_childs = strtoul(value, NULL, 10);
1194 info(udev, "initialize max_childs to %u\n", max_childs);
1196 static_dev_create(udev);
1197 static_dev_create_from_modules(udev);
1198 udev_rules_apply_static_dev_perms(rules);
1200 udev_list_init(&event_list);
1201 udev_list_init(&worker_list);
1203 while (!udev_exit) {
1207 /* set timeout to kill idle workers */
1208 if (udev_list_is_empty(&event_list) && childs > 2)
1212 /* wait for events */
1213 fdcount = poll(pfd, ARRAY_SIZE(pfd), timeout);
1217 /* timeout - kill idle workers */
1219 worker_kill(udev, 2);
1221 /* event has finished */
1222 if (pfd[FD_WORKER].revents & POLLIN)
1225 /* get kernel uevent */
1226 if (pfd[FD_NETLINK].revents & POLLIN) {
1227 struct udev_device *dev;
1229 dev = udev_monitor_receive_device(monitor);
1231 event_queue_insert(dev);
1233 udev_device_unref(dev);
1236 /* start new events */
1237 if (!udev_list_is_empty(&event_list) && !stop_exec_queue)
1241 if (pfd[FD_SIGNAL].revents & POLLIN) {
1242 struct signalfd_siginfo fdsi;
1245 size = read(pfd[FD_SIGNAL].fd, &fdsi, sizeof(struct signalfd_siginfo));
1246 if (size == sizeof(struct signalfd_siginfo))
1247 handle_signal(udev, fdsi.ssi_signo);
1250 /* device node and rules directory inotify watch */
1251 if (pfd[FD_INOTIFY].revents & POLLIN)
1252 handle_inotify(udev);
1255 * get control message
1257 * This needs to be after the inotify handling, to make sure,
1258 * that the settle signal is send back after the possibly generated
1259 * "change" events by the inotify device node watch.
1261 if (pfd[FD_CONTROL].revents & POLLIN)
1262 handle_ctrl_msg(udev_ctrl);
1264 /* rules changed, set by inotify or a HUP signal */
1265 if (reload_config) {
1266 struct udev_rules *rules_new;
1268 worker_kill(udev, 0);
1269 rules_new = udev_rules_new(udev, resolve_names);
1270 if (rules_new != NULL) {
1271 udev_rules_unref(rules);
1278 udev_queue_export_cleanup(udev_queue_export);
1281 udev_queue_export_unref(udev_queue_export);
1282 udev_rules_unref(rules);
1283 udev_ctrl_unref(udev_ctrl);
1284 if (pfd[FD_SIGNAL].fd >= 0)
1285 close(pfd[FD_SIGNAL].fd);
1286 if (worker_watch[READ_END] >= 0)
1287 close(worker_watch[READ_END]);
1288 if (worker_watch[WRITE_END] >= 0)
1289 close(worker_watch[WRITE_END]);
1290 udev_monitor_unref(monitor);
1291 udev_selinux_exit(udev);