2 * Copyright (C) 2004-2012 Kay Sievers <kay@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/>.
36 #include <sys/prctl.h>
37 #include <sys/socket.h>
39 #include <sys/signalfd.h>
40 #include <sys/epoll.h>
41 #include <sys/mount.h>
45 #include <sys/ioctl.h>
46 #include <sys/inotify.h>
47 #include <sys/utsname.h>
50 #include "udev-util.h"
51 #include "sd-daemon.h"
52 #include "cgroup-util.h"
53 #include "dev-setup.h"
58 void udev_main_log(struct udev *udev, int priority,
59 const char *file, int line, const char *fn,
60 const char *format, va_list args)
62 log_metav(priority, file, line, fn, format, args);
65 static struct udev_rules *rules;
66 static struct udev_ctrl *udev_ctrl;
67 static struct udev_monitor *monitor;
68 static int worker_watch[2] = { -1, -1 };
69 static int fd_signal = -1;
70 static int fd_ep = -1;
71 static int fd_inotify = -1;
72 static bool stop_exec_queue;
75 static int children_max;
76 static int exec_delay;
77 static sigset_t sigmask_orig;
78 static UDEV_LIST(event_list);
79 static UDEV_LIST(worker_list);
80 static char *udev_cgroup;
81 static bool udev_exit;
90 struct udev_list_node node;
92 struct udev_device *dev;
93 enum event_state state;
95 unsigned long long int delaying_seqnum;
96 unsigned long long int seqnum;
99 const char *devpath_old;
108 static inline struct event *node_to_event(struct udev_list_node *node)
110 return container_of(node, struct event, node);
113 static void event_queue_cleanup(struct udev *udev, enum event_state type);
123 struct udev_list_node node;
127 struct udev_monitor *monitor;
128 enum worker_state state;
130 usec_t event_start_usec;
133 /* passed from worker to main process */
134 struct worker_message {
139 static inline struct worker *node_to_worker(struct udev_list_node *node)
141 return container_of(node, struct worker, node);
144 static void event_queue_delete(struct event *event)
146 udev_list_node_remove(&event->node);
147 udev_device_unref(event->dev);
151 static struct worker *worker_ref(struct worker *worker)
157 static void worker_cleanup(struct worker *worker)
159 udev_list_node_remove(&worker->node);
160 udev_monitor_unref(worker->monitor);
165 static void worker_unref(struct worker *worker)
168 if (worker->refcount > 0)
170 log_debug("worker [%u] cleaned up", worker->pid);
171 worker_cleanup(worker);
174 static void worker_list_cleanup(struct udev *udev)
176 struct udev_list_node *loop, *tmp;
178 udev_list_node_foreach_safe(loop, tmp, &worker_list) {
179 struct worker *worker = node_to_worker(loop);
181 worker_cleanup(worker);
185 static void worker_new(struct event *event)
187 struct udev *udev = event->udev;
188 struct worker *worker;
189 struct udev_monitor *worker_monitor;
192 /* listen for new events */
193 worker_monitor = udev_monitor_new_from_netlink(udev, NULL);
194 if (worker_monitor == NULL)
196 /* allow the main daemon netlink address to send devices to the worker */
197 udev_monitor_allow_unicast_sender(worker_monitor, monitor);
198 udev_monitor_enable_receiving(worker_monitor);
200 worker = new0(struct worker, 1);
201 if (worker == NULL) {
202 udev_monitor_unref(worker_monitor);
205 /* worker + event reference */
206 worker->refcount = 2;
212 struct udev_device *dev = NULL;
214 struct epoll_event ep_signal, ep_monitor;
216 int rc = EXIT_SUCCESS;
218 /* take initial device from queue */
223 worker_list_cleanup(udev);
224 event_queue_cleanup(udev, EVENT_UNDEF);
225 udev_monitor_unref(monitor);
226 udev_ctrl_unref(udev_ctrl);
229 close(worker_watch[READ_END]);
232 fd_signal = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC);
234 log_error("error creating signalfd %m");
239 fd_ep = epoll_create1(EPOLL_CLOEXEC);
241 log_error("error creating epoll fd: %m");
246 memzero(&ep_signal, sizeof(struct epoll_event));
247 ep_signal.events = EPOLLIN;
248 ep_signal.data.fd = fd_signal;
250 fd_monitor = udev_monitor_get_fd(worker_monitor);
251 memzero(&ep_monitor, sizeof(struct epoll_event));
252 ep_monitor.events = EPOLLIN;
253 ep_monitor.data.fd = fd_monitor;
255 if (epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_signal, &ep_signal) < 0 ||
256 epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_monitor, &ep_monitor) < 0) {
257 log_error("fail to add fds to epoll: %m");
262 /* request TERM signal if parent exits */
263 prctl(PR_SET_PDEATHSIG, SIGTERM);
265 /* reset OOM score, we only protect the main daemon */
266 write_string_file("/proc/self/oom_score_adj", "0");
269 struct udev_event *udev_event;
270 struct worker_message msg;
274 log_debug("seq %llu running", udev_device_get_seqnum(dev));
275 udev_event = udev_event_new(dev);
276 if (udev_event == NULL) {
281 /* needed for SIGCHLD/SIGTERM in spawn() */
282 udev_event->fd_signal = fd_signal;
285 udev_event->exec_delay = exec_delay;
288 * Take a "read lock" on the device node; this establishes
289 * a concept of device "ownership" to serialize device
290 * access. External processes holding a "write lock" will
291 * cause udev to skip the event handling; in the case udev
292 * acquired the lock, the external process will block until
293 * udev has finished its event handling.
297 * <kabi_> since we make check - device seems unused - we try
298 * ioctl to deactivate - and device is found to be opened
299 * <kay> sure, you try to take a write lock
300 * <kay> if you get it udev is out
301 * <kay> if you can't get it, udev is busy
302 * <kabi_> we cannot deactivate openned device (as it is in-use)
303 * <kay> maybe we should just exclude dm from that thing entirely
304 * <kabi_> IMHO this sounds like a good plan for this moment
306 if (streq_ptr("block", udev_device_get_subsystem(dev)) &&
307 !startswith(udev_device_get_sysname(dev), "dm-")) {
308 struct udev_device *d = dev;
310 if (streq_ptr("partition", udev_device_get_devtype(d)))
311 d = udev_device_get_parent(d);
314 fd_lock = open(udev_device_get_devnode(d), O_RDONLY|O_CLOEXEC|O_NOFOLLOW|O_NONBLOCK);
315 if (fd_lock >= 0 && flock(fd_lock, LOCK_SH|LOCK_NB) < 0) {
316 log_debug("Unable to flock(%s), skipping event handling: %m", udev_device_get_devnode(d));
318 fd_lock = safe_close(fd_lock);
324 /* apply rules, create node, symlinks */
325 udev_event_execute_rules(udev_event, rules, &sigmask_orig);
327 udev_event_execute_run(udev_event, &sigmask_orig);
329 /* apply/restore inotify watch */
330 if (udev_event->inotify_watch) {
331 udev_watch_begin(udev, dev);
332 udev_device_update_db(dev);
337 /* send processed event back to libudev listeners */
338 udev_monitor_send_device(worker_monitor, NULL, dev);
341 /* send udevd the result of the event execution */
342 memzero(&msg, sizeof(struct worker_message));
345 send(worker_watch[WRITE_END], &msg, sizeof(struct worker_message), 0);
347 log_debug("seq %llu processed with %i", udev_device_get_seqnum(dev), err);
349 udev_device_unref(dev);
352 if (udev_event->sigterm) {
353 udev_event_unref(udev_event);
357 udev_event_unref(udev_event);
359 /* wait for more device messages from main udevd, or term signal */
360 while (dev == NULL) {
361 struct epoll_event ev[4];
365 fdcount = epoll_wait(fd_ep, ev, ELEMENTSOF(ev), -1);
369 log_error("failed to poll: %m");
373 for (i = 0; i < fdcount; i++) {
374 if (ev[i].data.fd == fd_monitor && ev[i].events & EPOLLIN) {
375 dev = udev_monitor_receive_device(worker_monitor);
377 } else if (ev[i].data.fd == fd_signal && ev[i].events & EPOLLIN) {
378 struct signalfd_siginfo fdsi;
381 size = read(fd_signal, &fdsi, sizeof(struct signalfd_siginfo));
382 if (size != sizeof(struct signalfd_siginfo))
384 switch (fdsi.ssi_signo) {
393 udev_device_unref(dev);
394 safe_close(fd_signal);
397 close(worker_watch[WRITE_END]);
398 udev_rules_unref(rules);
399 udev_builtin_exit(udev);
400 udev_monitor_unref(worker_monitor);
406 udev_monitor_unref(worker_monitor);
407 event->state = EVENT_QUEUED;
409 log_error("fork of child failed: %m");
412 /* close monitor, but keep address around */
413 udev_monitor_disconnect(worker_monitor);
414 worker->monitor = worker_monitor;
416 worker->state = WORKER_RUNNING;
417 worker->event_start_usec = now(CLOCK_MONOTONIC);
418 worker->event = event;
419 event->state = EVENT_RUNNING;
420 udev_list_node_append(&worker->node, &worker_list);
422 log_debug("seq %llu forked new worker [%u]", udev_device_get_seqnum(event->dev), pid);
427 static void event_run(struct event *event)
429 struct udev_list_node *loop;
431 udev_list_node_foreach(loop, &worker_list) {
432 struct worker *worker = node_to_worker(loop);
435 if (worker->state != WORKER_IDLE)
438 count = udev_monitor_send_device(monitor, worker->monitor, event->dev);
440 log_error("worker [%u] did not accept message %zi (%m), kill it", worker->pid, count);
441 kill(worker->pid, SIGKILL);
442 worker->state = WORKER_KILLED;
446 worker->event = event;
447 worker->state = WORKER_RUNNING;
448 worker->event_start_usec = now(CLOCK_MONOTONIC);
449 event->state = EVENT_RUNNING;
453 if (children >= children_max) {
454 if (children_max > 1)
455 log_debug("maximum number (%i) of children reached", children);
459 /* start new worker and pass initial device */
463 static int event_queue_insert(struct udev_device *dev)
467 event = new0(struct event, 1);
471 event->udev = udev_device_get_udev(dev);
473 event->seqnum = udev_device_get_seqnum(dev);
474 event->devpath = udev_device_get_devpath(dev);
475 event->devpath_len = strlen(event->devpath);
476 event->devpath_old = udev_device_get_devpath_old(dev);
477 event->devnum = udev_device_get_devnum(dev);
478 event->is_block = streq("block", udev_device_get_subsystem(dev));
479 event->ifindex = udev_device_get_ifindex(dev);
481 if (streq(udev_device_get_subsystem(dev), "firmware"))
482 event->nodelay = true;
485 log_debug("seq %llu queued, '%s' '%s'", udev_device_get_seqnum(dev),
486 udev_device_get_action(dev), udev_device_get_subsystem(dev));
488 event->state = EVENT_QUEUED;
489 udev_list_node_append(&event->node, &event_list);
493 static void worker_kill(struct udev *udev)
495 struct udev_list_node *loop;
497 udev_list_node_foreach(loop, &worker_list) {
498 struct worker *worker = node_to_worker(loop);
500 if (worker->state == WORKER_KILLED)
503 worker->state = WORKER_KILLED;
504 kill(worker->pid, SIGTERM);
508 /* lookup event for identical, parent, child device */
509 static bool is_devpath_busy(struct event *event)
511 struct udev_list_node *loop;
514 /* check if queue contains events we depend on */
515 udev_list_node_foreach(loop, &event_list) {
516 struct event *loop_event = node_to_event(loop);
518 /* we already found a later event, earlier can not block us, no need to check again */
519 if (loop_event->seqnum < event->delaying_seqnum)
522 /* event we checked earlier still exists, no need to check again */
523 if (loop_event->seqnum == event->delaying_seqnum)
526 /* found ourself, no later event can block us */
527 if (loop_event->seqnum >= event->seqnum)
530 /* check major/minor */
531 if (major(event->devnum) != 0 && event->devnum == loop_event->devnum && event->is_block == loop_event->is_block)
534 /* check network device ifindex */
535 if (event->ifindex != 0 && event->ifindex == loop_event->ifindex)
538 /* check our old name */
539 if (event->devpath_old != NULL && streq(loop_event->devpath, event->devpath_old)) {
540 event->delaying_seqnum = loop_event->seqnum;
544 /* compare devpath */
545 common = MIN(loop_event->devpath_len, event->devpath_len);
547 /* one devpath is contained in the other? */
548 if (memcmp(loop_event->devpath, event->devpath, common) != 0)
551 /* identical device event found */
552 if (loop_event->devpath_len == event->devpath_len) {
553 /* devices names might have changed/swapped in the meantime */
554 if (major(event->devnum) != 0 && (event->devnum != loop_event->devnum || event->is_block != loop_event->is_block))
556 if (event->ifindex != 0 && event->ifindex != loop_event->ifindex)
558 event->delaying_seqnum = loop_event->seqnum;
563 /* allow to bypass the dependency tracking */
568 /* parent device event found */
569 if (event->devpath[common] == '/') {
570 event->delaying_seqnum = loop_event->seqnum;
574 /* child device event found */
575 if (loop_event->devpath[common] == '/') {
576 event->delaying_seqnum = loop_event->seqnum;
580 /* no matching device */
587 static void event_queue_start(struct udev *udev)
589 struct udev_list_node *loop;
591 udev_list_node_foreach(loop, &event_list) {
592 struct event *event = node_to_event(loop);
594 if (event->state != EVENT_QUEUED)
597 /* do not start event if parent or child event is still running */
598 if (is_devpath_busy(event))
605 static void event_queue_cleanup(struct udev *udev, enum event_state match_type)
607 struct udev_list_node *loop, *tmp;
609 udev_list_node_foreach_safe(loop, tmp, &event_list) {
610 struct event *event = node_to_event(loop);
612 if (match_type != EVENT_UNDEF && match_type != event->state)
615 event_queue_delete(event);
619 static void worker_returned(int fd_worker)
622 struct worker_message msg;
624 struct udev_list_node *loop;
626 size = recv(fd_worker, &msg, sizeof(struct worker_message), MSG_DONTWAIT);
627 if (size != sizeof(struct worker_message))
630 /* lookup worker who sent the signal */
631 udev_list_node_foreach(loop, &worker_list) {
632 struct worker *worker = node_to_worker(loop);
634 if (worker->pid != msg.pid)
637 /* worker returned */
639 worker->event->exitcode = msg.exitcode;
640 event_queue_delete(worker->event);
641 worker->event = NULL;
643 if (worker->state != WORKER_KILLED)
644 worker->state = WORKER_IDLE;
645 worker_unref(worker);
651 /* receive the udevd message from userspace */
652 static struct udev_ctrl_connection *handle_ctrl_msg(struct udev_ctrl *uctrl)
654 struct udev *udev = udev_ctrl_get_udev(uctrl);
655 struct udev_ctrl_connection *ctrl_conn;
656 struct udev_ctrl_msg *ctrl_msg = NULL;
660 ctrl_conn = udev_ctrl_get_connection(uctrl);
661 if (ctrl_conn == NULL)
664 ctrl_msg = udev_ctrl_receive_msg(ctrl_conn);
665 if (ctrl_msg == NULL)
668 i = udev_ctrl_get_set_log_level(ctrl_msg);
670 log_debug("udevd message (SET_LOG_LEVEL) received, log_priority=%i", i);
671 log_set_max_level(i);
672 udev_set_log_priority(udev, i);
676 if (udev_ctrl_get_stop_exec_queue(ctrl_msg) > 0) {
677 log_debug("udevd message (STOP_EXEC_QUEUE) received");
678 stop_exec_queue = true;
681 if (udev_ctrl_get_start_exec_queue(ctrl_msg) > 0) {
682 log_debug("udevd message (START_EXEC_QUEUE) received");
683 stop_exec_queue = false;
686 if (udev_ctrl_get_reload(ctrl_msg) > 0) {
687 log_debug("udevd message (RELOAD) received");
691 str = udev_ctrl_get_set_env(ctrl_msg);
699 val = strchr(key, '=');
703 if (val[0] == '\0') {
704 log_debug("udevd message (ENV) received, unset '%s'", key);
705 udev_add_property(udev, key, NULL);
707 log_debug("udevd message (ENV) received, set '%s=%s'", key, val);
708 udev_add_property(udev, key, val);
711 log_error("wrong key format '%s'", key);
718 i = udev_ctrl_get_set_children_max(ctrl_msg);
720 log_debug("udevd message (SET_MAX_CHILDREN) received, children_max=%i", i);
724 if (udev_ctrl_get_ping(ctrl_msg) > 0)
725 log_debug("udevd message (SYNC) received");
727 if (udev_ctrl_get_exit(ctrl_msg) > 0) {
728 log_debug("udevd message (EXIT) received");
730 /* keep reference to block the client until we exit */
731 udev_ctrl_connection_ref(ctrl_conn);
734 udev_ctrl_msg_unref(ctrl_msg);
735 return udev_ctrl_connection_unref(ctrl_conn);
738 static int synthesize_change(struct udev_device *dev) {
739 char filename[UTIL_PATH_SIZE];
742 if (streq_ptr("block", udev_device_get_subsystem(dev)) &&
743 streq_ptr("disk", udev_device_get_devtype(dev)) &&
744 !startswith(udev_device_get_sysname(dev), "dm-")) {
745 bool part_table_read = false;
746 bool has_partitions = false;
748 struct udev *udev = udev_device_get_udev(dev);
749 _cleanup_udev_enumerate_unref_ struct udev_enumerate *e = NULL;
750 struct udev_list_entry *item;
753 * Try to re-read the partition table. This only succeeds if
754 * none of the devices is busy. The kernel returns 0 if no
755 * partition table is found, and we will not get an event for
758 fd = open(udev_device_get_devnode(dev), O_RDONLY|O_CLOEXEC|O_NOFOLLOW|O_NONBLOCK);
760 r = flock(fd, LOCK_EX|LOCK_NB);
762 r = ioctl(fd, BLKRRPART, 0);
766 part_table_read = true;
769 /* search for partitions */
770 e = udev_enumerate_new(udev);
774 r = udev_enumerate_add_match_parent(e, dev);
778 r = udev_enumerate_add_match_subsystem(e, "block");
782 r = udev_enumerate_scan_devices(e);
786 udev_list_entry_foreach(item, udev_enumerate_get_list_entry(e)) {
787 _cleanup_udev_device_unref_ struct udev_device *d = NULL;
789 d = udev_device_new_from_syspath(udev, udev_list_entry_get_name(item));
793 if (!streq_ptr("partition", udev_device_get_devtype(d)))
796 has_partitions = true;
801 * We have partitions and re-read the table, the kernel already sent
802 * out a "change" event for the disk, and "remove/add" for all
805 if (part_table_read && has_partitions)
809 * We have partitions but re-reading the partition table did not
810 * work, synthesize "change" for the disk and all partitions.
812 log_debug("device %s closed, synthesising 'change'", udev_device_get_devnode(dev));
813 strscpyl(filename, sizeof(filename), udev_device_get_syspath(dev), "/uevent", NULL);
814 write_string_file(filename, "change");
816 udev_list_entry_foreach(item, udev_enumerate_get_list_entry(e)) {
817 _cleanup_udev_device_unref_ struct udev_device *d = NULL;
819 d = udev_device_new_from_syspath(udev, udev_list_entry_get_name(item));
823 if (!streq_ptr("partition", udev_device_get_devtype(d)))
826 log_debug("device %s closed, synthesising partition '%s' 'change'",
827 udev_device_get_devnode(dev), udev_device_get_devnode(d));
828 strscpyl(filename, sizeof(filename), udev_device_get_syspath(d), "/uevent", NULL);
829 write_string_file(filename, "change");
835 log_debug("device %s closed, synthesising 'change'", udev_device_get_devnode(dev));
836 strscpyl(filename, sizeof(filename), udev_device_get_syspath(dev), "/uevent", NULL);
837 write_string_file(filename, "change");
842 static int handle_inotify(struct udev *udev)
846 struct inotify_event *ev;
849 r = ioctl(fd_inotify, FIONREAD, &nbytes);
850 if (r < 0 || nbytes <= 0)
853 buf = malloc(nbytes);
855 log_error("error getting buffer for inotify");
859 nbytes = read(fd_inotify, buf, nbytes);
861 for (pos = 0; pos < nbytes; pos += sizeof(struct inotify_event) + ev->len) {
862 struct udev_device *dev;
864 ev = (struct inotify_event *)(buf + pos);
865 dev = udev_watch_lookup(udev, ev->wd);
869 log_debug("inotify event: %x for %s", ev->mask, udev_device_get_devnode(dev));
870 if (ev->mask & IN_CLOSE_WRITE)
871 synthesize_change(dev);
872 else if (ev->mask & IN_IGNORED)
873 udev_watch_end(udev, dev);
875 udev_device_unref(dev);
882 static void handle_signal(struct udev *udev, int signo)
893 struct udev_list_node *loop, *tmp;
895 pid = waitpid(-1, &status, WNOHANG);
899 udev_list_node_foreach_safe(loop, tmp, &worker_list) {
900 struct worker *worker = node_to_worker(loop);
902 if (worker->pid != pid)
904 log_debug("worker [%u] exit", pid);
906 if (WIFEXITED(status)) {
907 if (WEXITSTATUS(status) != 0)
908 log_error("worker [%u] exit with return code %i",
909 pid, WEXITSTATUS(status));
910 } else if (WIFSIGNALED(status)) {
911 log_error("worker [%u] terminated by signal %i (%s)",
912 pid, WTERMSIG(status), strsignal(WTERMSIG(status)));
913 } else if (WIFSTOPPED(status)) {
914 log_error("worker [%u] stopped", pid);
915 } else if (WIFCONTINUED(status)) {
916 log_error("worker [%u] continued", pid);
918 log_error("worker [%u] exit with status 0x%04x", pid, status);
921 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
923 log_error("worker [%u] failed while handling '%s'",
924 pid, worker->event->devpath);
925 worker->event->exitcode = -32;
926 event_queue_delete(worker->event);
928 /* drop reference taken for state 'running' */
929 worker_unref(worker);
932 worker_unref(worker);
943 static int systemd_fds(struct udev *udev, int *rctrl, int *rnetlink)
945 int ctrl = -1, netlink = -1;
948 n = sd_listen_fds(true);
952 for (fd = SD_LISTEN_FDS_START; fd < n + SD_LISTEN_FDS_START; fd++) {
953 if (sd_is_socket(fd, AF_LOCAL, SOCK_SEQPACKET, -1)) {
960 if (sd_is_socket(fd, AF_NETLINK, SOCK_RAW, -1)) {
970 if (ctrl < 0 || netlink < 0)
973 log_debug("ctrl=%i netlink=%i", ctrl, netlink);
980 * read the kernel commandline, in case we need to get into debug mode
981 * udev.log-priority=<level> syslog priority
982 * udev.children-max=<number of workers> events are fully serialized if set to 1
983 * udev.exec-delay=<number of seconds> delay execution of every executed program
985 static void kernel_cmdline_options(struct udev *udev)
987 _cleanup_free_ char *line = NULL;
992 r = proc_cmdline(&line);
994 log_warning("Failed to read /proc/cmdline, ignoring: %s", strerror(-r));
998 FOREACH_WORD_QUOTED(w, l, line, state) {
1005 /* accept the same options for the initrd, prefixed with "rd." */
1006 if (in_initrd() && startswith(s, "rd."))
1011 if (startswith(opt, "udev.log-priority=")) {
1014 prio = util_log_priority(opt + 18);
1015 log_set_max_level(prio);
1016 udev_set_log_priority(udev, prio);
1017 } else if (startswith(opt, "udev.children-max=")) {
1018 children_max = strtoul(opt + 18, NULL, 0);
1019 } else if (startswith(opt, "udev.exec-delay=")) {
1020 exec_delay = strtoul(opt + 16, NULL, 0);
1027 int main(int argc, char *argv[])
1031 int daemonize = false;
1032 int resolve_names = 1;
1033 static const struct option options[] = {
1034 { "daemon", no_argument, NULL, 'd' },
1035 { "debug", no_argument, NULL, 'D' },
1036 { "children-max", required_argument, NULL, 'c' },
1037 { "exec-delay", required_argument, NULL, 'e' },
1038 { "resolve-names", required_argument, NULL, 'N' },
1039 { "help", no_argument, NULL, 'h' },
1040 { "version", no_argument, NULL, 'V' },
1044 int fd_netlink = -1;
1046 struct epoll_event ep_ctrl, ep_inotify, ep_signal, ep_netlink, ep_worker;
1047 struct udev_ctrl_connection *ctrl_conn = NULL;
1054 log_set_target(LOG_TARGET_AUTO);
1055 log_parse_environment();
1058 udev_set_log_fn(udev, udev_main_log);
1059 log_set_max_level(udev_get_log_priority(udev));
1061 log_debug("version %s", VERSION);
1067 option = getopt_long(argc, argv, "c:de:DtN:hV", options, NULL);
1076 children_max = strtoul(optarg, NULL, 0);
1079 exec_delay = strtoul(optarg, NULL, 0);
1083 log_set_max_level(LOG_DEBUG);
1084 udev_set_log_priority(udev, LOG_DEBUG);
1087 if (streq(optarg, "early")) {
1089 } else if (streq(optarg, "late")) {
1091 } else if (streq(optarg, "never")) {
1094 fprintf(stderr, "resolve-names must be early, late or never\n");
1095 log_error("resolve-names must be early, late or never");
1100 printf("Usage: udevd OPTIONS\n"
1103 " --children-max=<maximum number of workers>\n"
1104 " --exec-delay=<seconds to wait before executing RUN=>\n"
1105 " --resolve-names=early|late|never\n"
1111 printf("%s\n", VERSION);
1118 kernel_cmdline_options(udev);
1120 if (getuid() != 0) {
1121 fprintf(stderr, "root privileges required\n");
1122 log_error("root privileges required");
1126 /* set umask before creating any file/directory */
1130 mkdir("/run/udev", 0755);
1134 /* before opening new files, make sure std{in,out,err} fds are in a sane state */
1138 fd = open("/dev/null", O_RDWR);
1140 if (write(STDOUT_FILENO, 0, 0) < 0)
1141 dup2(fd, STDOUT_FILENO);
1142 if (write(STDERR_FILENO, 0, 0) < 0)
1143 dup2(fd, STDERR_FILENO);
1144 if (fd > STDERR_FILENO)
1147 fprintf(stderr, "cannot open /dev/null\n");
1148 log_error("cannot open /dev/null");
1152 if (systemd_fds(udev, &fd_ctrl, &fd_netlink) >= 0) {
1153 /* get control and netlink socket from systemd */
1154 udev_ctrl = udev_ctrl_new_from_fd(udev, fd_ctrl);
1155 if (udev_ctrl == NULL) {
1156 log_error("error taking over udev control socket");
1161 monitor = udev_monitor_new_from_netlink_fd(udev, "kernel", fd_netlink);
1162 if (monitor == NULL) {
1163 log_error("error taking over netlink socket");
1168 /* get our own cgroup, we regularly kill everything udev has left behind */
1169 if (cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, 0, &udev_cgroup) < 0)
1172 /* open control and netlink socket */
1173 udev_ctrl = udev_ctrl_new(udev);
1174 if (udev_ctrl == NULL) {
1175 fprintf(stderr, "error initializing udev control socket");
1176 log_error("error initializing udev control socket");
1180 fd_ctrl = udev_ctrl_get_fd(udev_ctrl);
1182 monitor = udev_monitor_new_from_netlink(udev, "kernel");
1183 if (monitor == NULL) {
1184 fprintf(stderr, "error initializing netlink socket\n");
1185 log_error("error initializing netlink socket");
1189 fd_netlink = udev_monitor_get_fd(monitor);
1192 if (udev_monitor_enable_receiving(monitor) < 0) {
1193 fprintf(stderr, "error binding netlink socket\n");
1194 log_error("error binding netlink socket");
1199 if (udev_ctrl_enable_receiving(udev_ctrl) < 0) {
1200 fprintf(stderr, "error binding udev control socket\n");
1201 log_error("error binding udev control socket");
1206 udev_monitor_set_receive_buffer_size(monitor, 128 * 1024 * 1024);
1216 log_error("fork of daemon failed: %m");
1221 goto exit_daemonize;
1226 write_string_file("/proc/self/oom_score_adj", "-1000");
1228 sd_notify(1, "READY=1");
1231 print_kmsg("starting version " VERSION "\n");
1236 fd = open("/dev/null", O_RDWR);
1238 dup2(fd, STDIN_FILENO);
1239 dup2(fd, STDOUT_FILENO);
1240 dup2(fd, STDERR_FILENO);
1245 fd_inotify = udev_watch_init(udev);
1246 if (fd_inotify < 0) {
1247 fprintf(stderr, "error initializing inotify\n");
1248 log_error("error initializing inotify");
1252 udev_watch_restore(udev);
1254 /* block and listen to all signals on signalfd */
1256 sigprocmask(SIG_SETMASK, &mask, &sigmask_orig);
1257 fd_signal = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC);
1258 if (fd_signal < 0) {
1259 fprintf(stderr, "error creating signalfd\n");
1260 log_error("error creating signalfd");
1265 /* unnamed socket from workers to the main daemon */
1266 if (socketpair(AF_LOCAL, SOCK_DGRAM|SOCK_CLOEXEC, 0, worker_watch) < 0) {
1267 fprintf(stderr, "error creating socketpair\n");
1268 log_error("error creating socketpair");
1272 fd_worker = worker_watch[READ_END];
1274 udev_builtin_init(udev);
1276 rules = udev_rules_new(udev, resolve_names);
1277 if (rules == NULL) {
1278 log_error("error reading rules");
1282 memzero(&ep_ctrl, sizeof(struct epoll_event));
1283 ep_ctrl.events = EPOLLIN;
1284 ep_ctrl.data.fd = fd_ctrl;
1286 memzero(&ep_inotify, sizeof(struct epoll_event));
1287 ep_inotify.events = EPOLLIN;
1288 ep_inotify.data.fd = fd_inotify;
1290 memzero(&ep_signal, sizeof(struct epoll_event));
1291 ep_signal.events = EPOLLIN;
1292 ep_signal.data.fd = fd_signal;
1294 memzero(&ep_netlink, sizeof(struct epoll_event));
1295 ep_netlink.events = EPOLLIN;
1296 ep_netlink.data.fd = fd_netlink;
1298 memzero(&ep_worker, sizeof(struct epoll_event));
1299 ep_worker.events = EPOLLIN;
1300 ep_worker.data.fd = fd_worker;
1302 fd_ep = epoll_create1(EPOLL_CLOEXEC);
1304 log_error("error creating epoll fd: %m");
1307 if (epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_ctrl, &ep_ctrl) < 0 ||
1308 epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_inotify, &ep_inotify) < 0 ||
1309 epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_signal, &ep_signal) < 0 ||
1310 epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_netlink, &ep_netlink) < 0 ||
1311 epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_worker, &ep_worker) < 0) {
1312 log_error("fail to add fds to epoll: %m");
1316 if (children_max <= 0) {
1321 if (sched_getaffinity(0, sizeof (cpu_set), &cpu_set) == 0) {
1322 children_max += CPU_COUNT(&cpu_set) * 2;
1325 log_debug("set children_max to %u", children_max);
1327 rc = udev_rules_apply_static_dev_perms(rules);
1329 log_error("failed to apply permissions on static device nodes - %s", strerror(-rc));
1331 udev_list_node_init(&event_list);
1332 udev_list_node_init(&worker_list);
1335 static usec_t last_usec;
1336 struct epoll_event ev[8];
1339 bool is_worker, is_signal, is_inotify, is_netlink, is_ctrl;
1343 /* close sources of new events and discard buffered events */
1345 epoll_ctl(fd_ep, EPOLL_CTL_DEL, fd_ctrl, NULL);
1348 if (monitor != NULL) {
1349 epoll_ctl(fd_ep, EPOLL_CTL_DEL, fd_netlink, NULL);
1350 udev_monitor_unref(monitor);
1353 if (fd_inotify >= 0) {
1354 epoll_ctl(fd_ep, EPOLL_CTL_DEL, fd_inotify, NULL);
1359 /* discard queued events and kill workers */
1360 event_queue_cleanup(udev, EVENT_QUEUED);
1363 /* exit after all has cleaned up */
1364 if (udev_list_node_is_empty(&event_list) && children == 0)
1367 /* timeout at exit for workers to finish */
1368 timeout = 30 * MSEC_PER_SEC;
1369 } else if (udev_list_node_is_empty(&event_list) && children == 0) {
1373 /* cleanup possible left-over processes in our cgroup */
1375 cg_kill(SYSTEMD_CGROUP_CONTROLLER, udev_cgroup, SIGKILL, false, true, NULL);
1377 /* kill idle or hanging workers */
1378 timeout = 3 * MSEC_PER_SEC;
1381 /* tell settle that we are busy or idle */
1382 if (!udev_list_node_is_empty(&event_list)) {
1385 fd = open("/run/udev/queue", O_WRONLY|O_CREAT|O_CLOEXEC|O_TRUNC|O_NOFOLLOW, 0444);
1389 unlink("/run/udev/queue");
1392 fdcount = epoll_wait(fd_ep, ev, ELEMENTSOF(ev), timeout);
1397 struct udev_list_node *loop;
1401 log_error("timeout, giving up waiting for workers to finish");
1405 /* kill idle workers */
1406 if (udev_list_node_is_empty(&event_list)) {
1407 log_debug("cleanup idle workers");
1411 /* check for hanging events */
1412 udev_list_node_foreach(loop, &worker_list) {
1413 struct worker *worker = node_to_worker(loop);
1415 if (worker->state != WORKER_RUNNING)
1418 if ((now(CLOCK_MONOTONIC) - worker->event_start_usec) > 30 * USEC_PER_SEC) {
1419 log_error("worker [%u] %s timeout; kill it", worker->pid,
1420 worker->event ? worker->event->devpath : "<idle>");
1421 kill(worker->pid, SIGKILL);
1422 worker->state = WORKER_KILLED;
1424 /* drop reference taken for state 'running' */
1425 worker_unref(worker);
1426 if (worker->event) {
1427 log_error("seq %llu '%s' killed", udev_device_get_seqnum(worker->event->dev), worker->event->devpath);
1428 worker->event->exitcode = -64;
1429 event_queue_delete(worker->event);
1430 worker->event = NULL;
1437 is_worker = is_signal = is_inotify = is_netlink = is_ctrl = false;
1438 for (i = 0; i < fdcount; i++) {
1439 if (ev[i].data.fd == fd_worker && ev[i].events & EPOLLIN)
1441 else if (ev[i].data.fd == fd_netlink && ev[i].events & EPOLLIN)
1443 else if (ev[i].data.fd == fd_signal && ev[i].events & EPOLLIN)
1445 else if (ev[i].data.fd == fd_inotify && ev[i].events & EPOLLIN)
1447 else if (ev[i].data.fd == fd_ctrl && ev[i].events & EPOLLIN)
1451 /* check for changed config, every 3 seconds at most */
1452 if ((now(CLOCK_MONOTONIC) - last_usec) > 3 * USEC_PER_SEC) {
1453 if (udev_rules_check_timestamp(rules))
1455 if (udev_builtin_validate(udev))
1458 last_usec = now(CLOCK_MONOTONIC);
1461 /* reload requested, HUP signal received, rules changed, builtin changed */
1464 rules = udev_rules_unref(rules);
1465 udev_builtin_exit(udev);
1469 /* event has finished */
1471 worker_returned(fd_worker);
1474 struct udev_device *dev;
1476 dev = udev_monitor_receive_device(monitor);
1478 udev_device_set_usec_initialized(dev, now(CLOCK_MONOTONIC));
1479 if (event_queue_insert(dev) < 0)
1480 udev_device_unref(dev);
1484 /* start new events */
1485 if (!udev_list_node_is_empty(&event_list) && !udev_exit && !stop_exec_queue) {
1486 udev_builtin_init(udev);
1488 rules = udev_rules_new(udev, resolve_names);
1490 event_queue_start(udev);
1494 struct signalfd_siginfo fdsi;
1497 size = read(fd_signal, &fdsi, sizeof(struct signalfd_siginfo));
1498 if (size == sizeof(struct signalfd_siginfo))
1499 handle_signal(udev, fdsi.ssi_signo);
1502 /* we are shutting down, the events below are not handled anymore */
1506 /* device node watch */
1508 handle_inotify(udev);
1511 * This needs to be after the inotify handling, to make sure,
1512 * that the ping is send back after the possibly generated
1513 * "change" events by the inotify device node watch.
1515 * A single time we may receive a client connection which we need to
1516 * keep open to block the client. It will be closed right before we
1520 ctrl_conn = handle_ctrl_msg(udev_ctrl);
1525 udev_ctrl_cleanup(udev_ctrl);
1526 unlink("/run/udev/queue");
1530 worker_list_cleanup(udev);
1531 event_queue_cleanup(udev, EVENT_UNDEF);
1532 udev_rules_unref(rules);
1533 udev_builtin_exit(udev);
1536 if (worker_watch[READ_END] >= 0)
1537 close(worker_watch[READ_END]);
1538 if (worker_watch[WRITE_END] >= 0)
1539 close(worker_watch[WRITE_END]);
1540 udev_monitor_unref(monitor);
1541 udev_ctrl_connection_unref(ctrl_conn);
1542 udev_ctrl_unref(udev_ctrl);