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 sigset_t orig_sigmask;
83 static struct udev_list_node event_list;
84 static struct udev_list_node worker_list;
85 static bool udev_exit;
86 static volatile sig_atomic_t worker_exit;
96 static struct pollfd pfd[] = {
97 [FD_NETLINK] = { .events = POLLIN },
98 [FD_WORKER] = { .events = POLLIN },
99 [FD_SIGNAL] = { .events = POLLIN },
100 [FD_INOTIFY] = { .events = POLLIN },
101 [FD_CONTROL] = { .events = POLLIN },
111 struct udev_list_node node;
113 struct udev_device *dev;
114 enum event_state state;
116 unsigned long long int delaying_seqnum;
117 unsigned long long int seqnum;
120 const char *devpath_old;
125 static struct event *node_to_event(struct udev_list_node *node)
129 event = (char *)node;
130 event -= offsetof(struct event, node);
131 return (struct event *)event;
142 struct udev_list_node node;
146 struct udev_monitor *monitor;
147 enum worker_state state;
151 /* passed from worker to main process */
152 struct worker_message {
157 static struct worker *node_to_worker(struct udev_list_node *node)
161 worker = (char *)node;
162 worker -= offsetof(struct worker, node);
163 return (struct worker *)worker;
166 static void event_queue_delete(struct event *event)
168 udev_list_node_remove(&event->node);
170 /* mark as failed, if "add" event returns non-zero */
171 if (event->exitcode != 0 && strcmp(udev_device_get_action(event->dev), "remove") != 0)
172 udev_queue_export_device_failed(udev_queue_export, event->dev);
174 udev_queue_export_device_finished(udev_queue_export, event->dev);
176 info(event->udev, "seq %llu done with %i\n", udev_device_get_seqnum(event->dev), event->exitcode);
177 udev_device_unref(event->dev);
181 static void event_sig_handler(int signum)
193 static struct worker *worker_ref(struct worker *worker)
199 static void worker_unref(struct worker *worker)
202 if (worker->refcount > 0)
205 udev_list_node_remove(&worker->node);
206 udev_monitor_unref(worker->monitor);
208 info(worker->udev, "worker [%u] cleaned up\n", worker->pid);
212 static void worker_new(struct event *event)
214 struct worker *worker;
215 struct udev_monitor *worker_monitor;
217 struct sigaction act;
219 /* listen for new events */
220 worker_monitor = udev_monitor_new_from_netlink(event->udev, NULL);
221 if (worker_monitor == NULL)
223 /* allow the main daemon netlink address to send devices to the worker */
224 udev_monitor_allow_unicast_sender(worker_monitor, monitor);
225 udev_monitor_enable_receiving(worker_monitor);
227 worker = calloc(1, sizeof(struct worker));
230 /* worker + event reference */
231 worker->refcount = 2;
232 worker->udev = event->udev;
238 struct udev_device *dev;
239 struct pollfd pmon = {
240 .fd = udev_monitor_get_fd(worker_monitor),
244 udev_queue_export_unref(udev_queue_export);
245 udev_monitor_unref(monitor);
246 udev_ctrl_unref(udev_ctrl);
247 close(pfd[FD_SIGNAL].fd);
248 close(worker_watch[READ_END]);
250 udev_log_init("udevd-work");
251 setpriority(PRIO_PROCESS, 0, UDEV_PRIORITY);
253 /* set signal handlers */
254 memset(&act, 0x00, sizeof(act));
255 act.sa_handler = event_sig_handler;
256 sigemptyset (&act.sa_mask);
258 sigaction(SIGTERM, &act, NULL);
259 sigaction(SIGALRM, &act, NULL);
261 /* unblock SIGALRM */
262 sigfillset(&sigmask);
263 sigdelset(&sigmask, SIGALRM);
264 sigprocmask(SIG_SETMASK, &sigmask, NULL);
265 /* SIGTERM is unblocked in ppoll() */
266 sigdelset(&sigmask, SIGTERM);
268 /* request TERM signal if parent exits */
269 prctl(PR_SET_PDEATHSIG, SIGTERM);
275 struct udev_event *udev_event;
276 struct worker_message msg = {};
280 info(event->udev, "seq %llu running\n", udev_device_get_seqnum(dev));
281 udev_event = udev_event_new(dev);
282 if (udev_event == NULL)
285 /* set timeout to prevent hanging processes */
286 alarm(UDEV_EVENT_TIMEOUT);
288 /* apply rules, create node, symlinks */
289 err = udev_event_execute_rules(udev_event, rules);
291 /* rules may change/disable the timeout */
292 if (udev_device_get_event_timeout(dev) >= 0)
293 alarm(udev_device_get_event_timeout(dev));
296 failed = udev_event_execute_run(udev_event, &orig_sigmask);
300 /* apply/restore inotify watch */
301 if (err == 0 && udev_event->inotify_watch) {
302 udev_watch_begin(udev_event->udev, dev);
303 udev_device_update_db(dev);
306 /* send processed event back to libudev listeners */
307 udev_monitor_send_device(worker_monitor, NULL, dev);
309 /* send udevd the result of the event execution */
312 else if (failed != 0)
313 msg.exitcode = failed;
315 send(worker_watch[WRITE_END], &msg, sizeof(struct worker_message), 0);
317 info(event->udev, "seq %llu processed with %i\n", udev_device_get_seqnum(dev), err);
318 udev_event_unref(udev_event);
319 udev_device_unref(dev);
322 /* wait for more device messages or signal from udevd */
323 while (!worker_exit) {
326 fdcount = ppoll(&pmon, 1, NULL, &sigmask);
330 if (pmon.revents & POLLIN) {
331 dev = udev_monitor_receive_device(worker_monitor);
336 } while (dev != NULL);
338 udev_monitor_unref(worker_monitor);
343 udev_monitor_unref(worker_monitor);
344 event->state = EVENT_QUEUED;
346 err(event->udev, "fork of child failed: %m\n");
349 /* close monitor, but keep address around */
350 udev_monitor_disconnect(worker_monitor);
351 worker->monitor = worker_monitor;
353 worker->state = WORKER_RUNNING;
354 worker->event = event;
355 event->state = EVENT_RUNNING;
356 udev_list_node_append(&worker->node, &worker_list);
358 info(event->udev, "seq %llu forked new worker [%u]\n", udev_device_get_seqnum(event->dev), pid);
363 static void event_run(struct event *event, bool force)
365 struct udev_list_node *loop;
367 udev_list_node_foreach(loop, &worker_list) {
368 struct worker *worker = node_to_worker(loop);
371 if (worker->state != WORKER_IDLE)
374 count = udev_monitor_send_device(monitor, worker->monitor, event->dev);
376 err(event->udev, "worker [%u] did not accept message %zi (%m), kill it\n", worker->pid, count);
377 kill(worker->pid, SIGKILL);
378 worker->state = WORKER_KILLED;
382 worker->event = event;
383 worker->state = WORKER_RUNNING;
384 event->state = EVENT_RUNNING;
388 if (!force && children >= children_max) {
389 info(event->udev, "maximum number (%i) of children reached\n", children);
393 /* start new worker and pass initial device */
397 static void event_queue_insert(struct udev_device *dev)
401 event = calloc(1, sizeof(struct event));
405 event->udev = udev_device_get_udev(dev);
407 event->seqnum = udev_device_get_seqnum(dev);
408 event->devpath = udev_device_get_devpath(dev);
409 event->devpath_len = strlen(event->devpath);
410 event->devpath_old = udev_device_get_devpath_old(dev);
411 event->devnum = udev_device_get_devnum(dev);
412 event->is_block = (strcmp("block", udev_device_get_subsystem(dev)) == 0);
414 udev_queue_export_device_queued(udev_queue_export, dev);
415 info(event->udev, "seq %llu queued, '%s' '%s'\n", udev_device_get_seqnum(dev),
416 udev_device_get_action(dev), udev_device_get_subsystem(dev));
418 event->state = EVENT_QUEUED;
419 udev_list_node_append(&event->node, &event_list);
421 /* run all events with a timeout set immediately */
422 if (udev_device_get_timeout(dev) > 0) {
423 event_run(event, true);
428 static void worker_kill(struct udev *udev, int retain)
430 struct udev_list_node *loop;
433 if (children <= retain)
436 max = children - retain;
438 udev_list_node_foreach(loop, &worker_list) {
439 struct worker *worker = node_to_worker(loop);
444 if (worker->state == WORKER_KILLED)
447 worker->state = WORKER_KILLED;
448 kill(worker->pid, SIGTERM);
452 /* lookup event for identical, parent, child device */
453 static bool is_devpath_busy(struct event *event)
455 struct udev_list_node *loop;
458 /* check if queue contains events we depend on */
459 udev_list_node_foreach(loop, &event_list) {
460 struct event *loop_event = node_to_event(loop);
462 /* we already found a later event, earlier can not block us, no need to check again */
463 if (loop_event->seqnum < event->delaying_seqnum)
466 /* event we checked earlier still exists, no need to check again */
467 if (loop_event->seqnum == event->delaying_seqnum)
470 /* found ourself, no later event can block us */
471 if (loop_event->seqnum >= event->seqnum)
474 /* check major/minor */
475 if (major(event->devnum) != 0 && event->devnum == loop_event->devnum && event->is_block == loop_event->is_block)
478 /* check our old name */
479 if (event->devpath_old != NULL && strcmp(loop_event->devpath, event->devpath_old) == 0) {
480 event->delaying_seqnum = loop_event->seqnum;
484 /* compare devpath */
485 common = MIN(loop_event->devpath_len, event->devpath_len);
487 /* one devpath is contained in the other? */
488 if (memcmp(loop_event->devpath, event->devpath, common) != 0)
491 /* identical device event found */
492 if (loop_event->devpath_len == event->devpath_len) {
493 event->delaying_seqnum = loop_event->seqnum;
497 /* parent device event found */
498 if (event->devpath[common] == '/') {
499 event->delaying_seqnum = loop_event->seqnum;
503 /* child device event found */
504 if (loop_event->devpath[common] == '/') {
505 event->delaying_seqnum = loop_event->seqnum;
509 /* no matching device */
516 static void events_start(struct udev *udev)
518 struct udev_list_node *loop;
520 udev_list_node_foreach(loop, &event_list) {
521 struct event *event = node_to_event(loop);
523 if (event->state != EVENT_QUEUED)
526 /* do not start event if parent or child event is still running */
527 if (is_devpath_busy(event)) {
528 dbg(udev, "delay seq %llu (%s)\n", event->seqnum, event->devpath);
532 event_run(event, false);
536 static void worker_returned(void)
539 struct worker_message msg;
541 struct udev_list_node *loop;
543 size = recv(pfd[FD_WORKER].fd, &msg, sizeof(struct worker_message), MSG_DONTWAIT);
544 if (size != sizeof(struct worker_message))
547 /* lookup worker who sent the signal */
548 udev_list_node_foreach(loop, &worker_list) {
549 struct worker *worker = node_to_worker(loop);
551 if (worker->pid != msg.pid)
554 /* worker returned */
555 worker->event->exitcode = msg.exitcode;
556 event_queue_delete(worker->event);
557 worker->event = NULL;
558 if (worker->state != WORKER_KILLED)
559 worker->state = WORKER_IDLE;
560 worker_unref(worker);
566 /* receive the udevd message from userspace */
567 static void handle_ctrl_msg(struct udev_ctrl *uctrl)
569 struct udev *udev = udev_ctrl_get_udev(uctrl);
570 struct udev_ctrl_msg *ctrl_msg;
574 ctrl_msg = udev_ctrl_receive_msg(uctrl);
575 if (ctrl_msg == NULL)
578 i = udev_ctrl_get_set_log_level(ctrl_msg);
580 info(udev, "udevd message (SET_LOG_PRIORITY) received, log_priority=%i\n", i);
581 udev_set_log_priority(udev, i);
582 worker_kill(udev, 0);
585 if (udev_ctrl_get_stop_exec_queue(ctrl_msg) > 0) {
586 info(udev, "udevd message (STOP_EXEC_QUEUE) received\n");
587 stop_exec_queue = true;
590 if (udev_ctrl_get_start_exec_queue(ctrl_msg) > 0) {
591 info(udev, "udevd message (START_EXEC_QUEUE) received\n");
592 stop_exec_queue = false;
595 if (udev_ctrl_get_reload_rules(ctrl_msg) > 0) {
596 info(udev, "udevd message (RELOAD_RULES) received\n");
597 reload_config = true;
600 str = udev_ctrl_get_set_env(ctrl_msg);
608 val = strchr(key, '=');
612 if (val[0] == '\0') {
613 info(udev, "udevd message (ENV) received, unset '%s'\n", key);
614 udev_add_property(udev, key, NULL);
616 info(udev, "udevd message (ENV) received, set '%s=%s'\n", key, val);
617 udev_add_property(udev, key, val);
620 err(udev, "wrong key format '%s'\n", key);
624 worker_kill(udev, 0);
627 i = udev_ctrl_get_set_children_max(ctrl_msg);
629 info(udev, "udevd message (SET_MAX_CHILDREN) received, children_max=%i\n", i);
633 settle_pid = udev_ctrl_get_settle(ctrl_msg);
634 if (settle_pid > 0) {
635 info(udev, "udevd message (SETTLE) received\n");
636 kill(settle_pid, SIGUSR1);
639 udev_ctrl_msg_unref(ctrl_msg);
642 /* read inotify messages */
643 static int handle_inotify(struct udev *udev)
647 struct inotify_event *ev;
649 if ((ioctl(pfd[FD_INOTIFY].fd, FIONREAD, &nbytes) < 0) || (nbytes <= 0))
652 buf = malloc(nbytes);
654 err(udev, "error getting buffer for inotify\n");
658 nbytes = read(pfd[FD_INOTIFY].fd, buf, nbytes);
660 for (pos = 0; pos < nbytes; pos += sizeof(struct inotify_event) + ev->len) {
661 struct udev_device *dev;
663 ev = (struct inotify_event *)(buf + pos);
667 info(udev, "inotify event: %x for %s\n", ev->mask, ev->name);
668 s = strstr(ev->name, ".rules");
671 if (strlen(s) != strlen(".rules"))
673 reload_config = true;
677 dev = udev_watch_lookup(udev, ev->wd);
679 info(udev, "inotify event: %x for %s\n", ev->mask, udev_device_get_devnode(dev));
680 if (ev->mask & IN_CLOSE_WRITE) {
681 char filename[UTIL_PATH_SIZE];
684 info(udev, "device %s closed, synthesising 'change'\n", udev_device_get_devnode(dev));
685 util_strscpyl(filename, sizeof(filename), udev_device_get_syspath(dev), "/uevent", NULL);
686 fd = open(filename, O_WRONLY);
687 if (fd < 0 || write(fd, "change", 6) < 0)
688 info(udev, "error writing uevent: %m\n");
691 if (ev->mask & IN_IGNORED)
692 udev_watch_end(udev, dev);
694 udev_device_unref(dev);
703 static void handle_signal(struct udev *udev, int signo)
714 struct udev_list_node *loop, *tmp;
716 pid = waitpid(-1, &status, WNOHANG);
720 udev_list_node_foreach_safe(loop, tmp, &worker_list) {
721 struct worker *worker = node_to_worker(loop);
723 if (worker->pid != pid)
726 info(udev, "worker [%u] exit\n", pid);
727 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
728 err(udev, "worker [%u] unexpectedly returned with status 0x%04x\n", pid, status);
729 if (worker->event != NULL) {
730 err(udev, "worker [%u] failed while handling '%s'\n", pid, worker->event->devpath);
731 worker->event->exitcode = -32;
732 event_queue_delete(worker->event);
733 /* drop reference from running event */
734 worker_unref(worker);
737 worker_unref(worker);
743 reload_config = true;
748 static void static_dev_create_from_modules(struct udev *udev)
750 struct utsname kernel;
751 char modules[UTIL_PATH_SIZE];
756 util_strscpyl(modules, sizeof(modules), "/lib/modules/", kernel.release, "/modules.devname", NULL);
757 f = fopen(modules, "r");
761 while (fgets(buf, sizeof(buf), f) != NULL) {
769 char filename[UTIL_PATH_SIZE];
775 s = strchr(modname, ' ');
781 s = strchr(devname, ' ');
787 s = strchr(devno, ' ');
789 s = strchr(devno, '\n');
792 if (sscanf(devno, "%c%u:%u", &type, &maj, &min) != 3)
796 mode = 0600 | S_IFCHR;
797 else if (type == 'b')
798 mode = 0600 | S_IFBLK;
802 util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev), "/", devname, NULL);
803 util_create_path(udev, filename);
804 udev_selinux_setfscreatecon(udev, filename, mode);
805 info(udev, "mknod '%s' %c%u:%u\n", filename, type, maj, min);
806 if (mknod(filename, mode, makedev(maj, min)) < 0 && errno == EEXIST)
807 utimensat(AT_FDCWD, filename, NULL, 0);
808 udev_selinux_resetfscreatecon(udev);
814 static int copy_dir(struct udev *udev, DIR *dir_from, DIR *dir_to, int maxdepth)
818 for (dent = readdir(dir_from); dent != NULL; dent = readdir(dir_from)) {
821 if (dent->d_name[0] == '.')
823 if (fstatat(dirfd(dir_from), dent->d_name, &stats, AT_SYMLINK_NOFOLLOW) != 0)
826 if (S_ISBLK(stats.st_mode) || S_ISCHR(stats.st_mode)) {
827 udev_selinux_setfscreateconat(udev, dirfd(dir_to), dent->d_name, stats.st_mode & 0777);
828 if (mknodat(dirfd(dir_to), dent->d_name, stats.st_mode, stats.st_rdev) == 0) {
829 fchmodat(dirfd(dir_to), dent->d_name, stats.st_mode & 0777, 0);
830 fchownat(dirfd(dir_to), dent->d_name, stats.st_uid, stats.st_gid, 0);
832 utimensat(dirfd(dir_to), dent->d_name, NULL, 0);
834 udev_selinux_resetfscreatecon(udev);
835 } else if (S_ISLNK(stats.st_mode)) {
836 char target[UTIL_PATH_SIZE];
839 len = readlinkat(dirfd(dir_from), dent->d_name, target, sizeof(target));
840 if (len <= 0 || len == (ssize_t)sizeof(target))
843 udev_selinux_setfscreateconat(udev, dirfd(dir_to), dent->d_name, S_IFLNK);
844 if (symlinkat(target, dirfd(dir_to), dent->d_name) < 0 && errno == EEXIST)
845 utimensat(dirfd(dir_to), dent->d_name, NULL, AT_SYMLINK_NOFOLLOW);
846 udev_selinux_resetfscreatecon(udev);
847 } else if (S_ISDIR(stats.st_mode)) {
848 DIR *dir2_from, *dir2_to;
853 udev_selinux_setfscreateconat(udev, dirfd(dir_to), dent->d_name, S_IFDIR|0755);
854 mkdirat(dirfd(dir_to), dent->d_name, 0755);
855 udev_selinux_resetfscreatecon(udev);
857 dir2_to = fdopendir(openat(dirfd(dir_to), dent->d_name, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC));
861 dir2_from = fdopendir(openat(dirfd(dir_from), dent->d_name, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC));
862 if (dir2_from == NULL) {
867 copy_dir(udev, dir2_from, dir2_to, maxdepth-1);
877 static void static_dev_create_links(struct udev *udev, DIR *dir)
883 static const struct stdlinks stdlinks[] = {
884 { "core", "/proc/kcore" },
885 { "fd", "/proc/self/fd" },
886 { "stdin", "/proc/self/fd/0" },
887 { "stdout", "/proc/self/fd/1" },
888 { "stderr", "/proc/self/fd/2" },
892 for (i = 0; i < ARRAY_SIZE(stdlinks); i++) {
893 udev_selinux_setfscreateconat(udev, dirfd(dir), stdlinks[i].link, S_IFLNK);
894 if (symlinkat(stdlinks[i].target, dirfd(dir), stdlinks[i].link) < 0 && errno == EEXIST)
895 utimensat(dirfd(dir), stdlinks[i].link, NULL, AT_SYMLINK_NOFOLLOW);
896 udev_selinux_resetfscreatecon(udev);
900 static void static_dev_create_from_devices(struct udev *udev, DIR *dir)
904 dir_from = opendir(LIBEXECDIR "/devices");
905 if (dir_from == NULL)
907 copy_dir(udev, dir_from, dir, 8);
911 static void static_dev_create(struct udev *udev)
915 dir = opendir(udev_get_dev_path(udev));
919 static_dev_create_links(udev, dir);
920 static_dev_create_from_devices(udev, dir);
925 static int mem_size_mb(void)
929 long int memsize = -1;
931 f = fopen("/proc/meminfo", "r");
935 while (fgets(buf, sizeof(buf), f) != NULL) {
938 if (sscanf(buf, "MemTotal: %ld kB", &value) == 1) {
939 memsize = value / 1024;
948 int main(int argc, char *argv[])
954 int daemonize = false;
955 int resolve_names = 1;
956 static const struct option options[] = {
957 { "daemon", no_argument, NULL, 'd' },
958 { "debug", no_argument, NULL, 'D' },
959 { "children-max", required_argument, NULL, 'c' },
960 { "resolve-names", required_argument, NULL, 'N' },
961 { "help", no_argument, NULL, 'h' },
962 { "version", no_argument, NULL, 'V' },
971 udev_log_init("udevd");
972 udev_set_log_fn(udev, log_fn);
973 info(udev, "version %s\n", VERSION);
974 udev_selinux_init(udev);
979 option = getopt_long(argc, argv, "dDthV", options, NULL);
988 children_max = strtoul(optarg, NULL, 10);
992 if (udev_get_log_priority(udev) < LOG_INFO)
993 udev_set_log_priority(udev, LOG_INFO);
996 if (strcmp (optarg, "early") == 0) {
998 } else if (strcmp (optarg, "late") == 0) {
1000 } else if (strcmp (optarg, "never") == 0) {
1003 fprintf(stderr, "resolve-names must be early, late or never\n");
1004 err(udev, "resolve-names must be early, late or never\n");
1009 printf("Usage: udevd [--help] [--daemon] [--children-max] [--debug] "
1010 "[--resolve-names=early|late|never] [--version]\n");
1013 printf("%s\n", VERSION);
1020 if (getuid() != 0) {
1021 fprintf(stderr, "root privileges required\n");
1022 err(udev, "root privileges required\n");
1026 /* make sure std{in,out,err} fd's are in a sane state */
1027 fd = open("/dev/null", O_RDWR);
1029 fprintf(stderr, "cannot open /dev/null\n");
1030 err(udev, "cannot open /dev/null\n");
1032 if (write(STDOUT_FILENO, 0, 0) < 0)
1033 dup2(fd, STDOUT_FILENO);
1034 if (write(STDERR_FILENO, 0, 0) < 0)
1035 dup2(fd, STDERR_FILENO);
1037 /* init control socket, bind() ensures, that only one udevd instance is running */
1038 udev_ctrl = udev_ctrl_new_from_socket(udev, UDEV_CTRL_SOCK_PATH);
1039 if (udev_ctrl == NULL) {
1040 fprintf(stderr, "error initializing control socket");
1041 err(udev, "error initializing udevd socket");
1045 if (udev_ctrl_enable_receiving(udev_ctrl) < 0) {
1046 fprintf(stderr, "error binding control socket, seems udevd is already running\n");
1047 err(udev, "error binding control socket, seems udevd is already running\n");
1051 pfd[FD_CONTROL].fd = udev_ctrl_get_fd(udev_ctrl);
1053 monitor = udev_monitor_new_from_netlink(udev, "kernel");
1054 if (monitor == NULL || udev_monitor_enable_receiving(monitor) < 0) {
1055 fprintf(stderr, "error initializing netlink socket\n");
1056 err(udev, "error initializing netlink socket\n");
1060 udev_monitor_set_receive_buffer_size(monitor, 128*1024*1024);
1061 pfd[FD_NETLINK].fd = udev_monitor_get_fd(monitor);
1063 pfd[FD_INOTIFY].fd = udev_watch_init(udev);
1064 if (pfd[FD_INOTIFY].fd < 0) {
1065 fprintf(stderr, "error initializing inotify\n");
1066 err(udev, "error initializing inotify\n");
1071 if (udev_get_rules_path(udev) != NULL) {
1072 inotify_add_watch(pfd[FD_INOTIFY].fd, udev_get_rules_path(udev),
1073 IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
1075 char filename[UTIL_PATH_SIZE];
1076 struct stat statbuf;
1078 inotify_add_watch(pfd[FD_INOTIFY].fd, LIBEXECDIR "/rules.d",
1079 IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
1080 inotify_add_watch(pfd[FD_INOTIFY].fd, SYSCONFDIR "/udev/rules.d",
1081 IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
1083 /* watch dynamic rules directory */
1084 util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev), "/.udev/rules.d", NULL);
1085 if (stat(filename, &statbuf) != 0) {
1086 util_create_path(udev, filename);
1087 udev_selinux_setfscreatecon(udev, filename, S_IFDIR|0755);
1088 mkdir(filename, 0755);
1089 udev_selinux_resetfscreatecon(udev);
1091 inotify_add_watch(pfd[FD_INOTIFY].fd, filename,
1092 IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
1094 udev_watch_restore(udev);
1096 /* block and listen to all signals on signalfd */
1098 sigprocmask(SIG_SETMASK, &mask, &orig_sigmask);
1099 pfd[FD_SIGNAL].fd = signalfd(-1, &mask, 0);
1100 if (pfd[FD_SIGNAL].fd < 0) {
1101 fprintf(stderr, "error getting signalfd\n");
1102 err(udev, "error getting signalfd\n");
1107 /* unnamed socket from workers to the main daemon */
1108 if (socketpair(AF_LOCAL, SOCK_DGRAM|SOCK_CLOEXEC, 0, worker_watch) < 0) {
1109 fprintf(stderr, "error getting socketpair\n");
1110 err(udev, "error getting socketpair\n");
1114 pfd[FD_WORKER].fd = worker_watch[READ_END];
1116 rules = udev_rules_new(udev, resolve_names);
1117 if (rules == NULL) {
1118 err(udev, "error reading rules\n");
1122 udev_queue_export = udev_queue_export_new(udev);
1123 if (udev_queue_export == NULL) {
1124 err(udev, "error creating queue file\n");
1136 err(udev, "fork of daemon failed: %m\n");
1145 f = fopen("/dev/kmsg", "w");
1147 fprintf(f, "<6>udev: starting version " VERSION "\n");
1151 /* redirect std{out,err} */
1153 dup2(fd, STDIN_FILENO);
1154 dup2(fd, STDOUT_FILENO);
1155 dup2(fd, STDERR_FILENO);
1157 if (fd > STDERR_FILENO)
1160 /* set scheduling priority for the daemon */
1161 setpriority(PRIO_PROCESS, 0, UDEVD_PRIORITY);
1167 /* OOM_DISABLE == -17 */
1168 fd = open("/proc/self/oom_adj", O_RDWR);
1170 err(udev, "error disabling OOM: %m\n");
1172 write(fd, "-17", 3);
1176 if (children_max <= 0) {
1177 const char *value = getenv("UDEVD_CHILDREN_MAX");
1180 children_max = strtoul(value, NULL, 10);
1182 int memsize = mem_size_mb();
1184 /* set value depending on the amount of RAM */
1186 children_max = 128 + (memsize / 8);
1191 info(udev, "set children_max to %u\n", children_max);
1193 static_dev_create(udev);
1194 static_dev_create_from_modules(udev);
1195 udev_rules_apply_static_dev_perms(rules);
1197 udev_list_init(&event_list);
1198 udev_list_init(&worker_list);
1200 while (!udev_exit) {
1204 /* set timeout to kill idle workers */
1205 if (udev_list_is_empty(&event_list) && children > 2)
1209 /* wait for events */
1210 fdcount = poll(pfd, ARRAY_SIZE(pfd), timeout);
1214 /* timeout - kill idle workers */
1216 worker_kill(udev, 2);
1218 /* event has finished */
1219 if (pfd[FD_WORKER].revents & POLLIN)
1222 /* get kernel uevent */
1223 if (pfd[FD_NETLINK].revents & POLLIN) {
1224 struct udev_device *dev;
1226 dev = udev_monitor_receive_device(monitor);
1228 event_queue_insert(dev);
1230 udev_device_unref(dev);
1233 /* start new events */
1234 if (!udev_list_is_empty(&event_list) && !stop_exec_queue)
1238 if (pfd[FD_SIGNAL].revents & POLLIN) {
1239 struct signalfd_siginfo fdsi;
1242 size = read(pfd[FD_SIGNAL].fd, &fdsi, sizeof(struct signalfd_siginfo));
1243 if (size == sizeof(struct signalfd_siginfo))
1244 handle_signal(udev, fdsi.ssi_signo);
1247 /* device node and rules directory inotify watch */
1248 if (pfd[FD_INOTIFY].revents & POLLIN)
1249 handle_inotify(udev);
1252 * get control message
1254 * This needs to be after the inotify handling, to make sure,
1255 * that the settle signal is send back after the possibly generated
1256 * "change" events by the inotify device node watch.
1258 if (pfd[FD_CONTROL].revents & POLLIN)
1259 handle_ctrl_msg(udev_ctrl);
1261 /* rules changed, set by inotify or a HUP signal */
1262 if (reload_config) {
1263 struct udev_rules *rules_new;
1265 worker_kill(udev, 0);
1266 rules_new = udev_rules_new(udev, resolve_names);
1267 if (rules_new != NULL) {
1268 udev_rules_unref(rules);
1275 udev_queue_export_cleanup(udev_queue_export);
1278 udev_queue_export_unref(udev_queue_export);
1279 udev_rules_unref(rules);
1280 udev_ctrl_unref(udev_ctrl);
1281 if (pfd[FD_SIGNAL].fd >= 0)
1282 close(pfd[FD_SIGNAL].fd);
1283 if (worker_watch[READ_END] >= 0)
1284 close(worker_watch[READ_END]);
1285 if (worker_watch[WRITE_END] >= 0)
1286 close(worker_watch[WRITE_END]);
1287 udev_monitor_unref(monitor);
1288 udev_selinux_exit(udev);