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 shared lock on the device node; this establishes
289 * a concept of device "ownership" to serialize device
290 * access. External processes holding an exclusive lock will
291 * cause udev to skip the event handling; in the case udev
292 * acquired the lock, the external process can block until
293 * udev has finished its event handling.
295 if (!streq_ptr(udev_device_get_action(dev), "remove") &&
296 streq_ptr("block", udev_device_get_subsystem(dev)) &&
297 !startswith(udev_device_get_sysname(dev), "dm-") &&
298 !startswith(udev_device_get_sysname(dev), "md")) {
299 struct udev_device *d = dev;
301 if (streq_ptr("partition", udev_device_get_devtype(d)))
302 d = udev_device_get_parent(d);
305 fd_lock = open(udev_device_get_devnode(d), O_RDONLY|O_CLOEXEC|O_NOFOLLOW|O_NONBLOCK);
306 if (fd_lock >= 0 && flock(fd_lock, LOCK_SH|LOCK_NB) < 0) {
307 log_debug("Unable to flock(%s), skipping event handling: %m", udev_device_get_devnode(d));
309 fd_lock = safe_close(fd_lock);
315 /* apply rules, create node, symlinks */
316 udev_event_execute_rules(udev_event, rules, &sigmask_orig);
318 udev_event_execute_run(udev_event, &sigmask_orig);
320 /* apply/restore inotify watch */
321 if (udev_event->inotify_watch) {
322 udev_watch_begin(udev, dev);
323 udev_device_update_db(dev);
328 /* send processed event back to libudev listeners */
329 udev_monitor_send_device(worker_monitor, NULL, dev);
332 /* send udevd the result of the event execution */
333 memzero(&msg, sizeof(struct worker_message));
336 send(worker_watch[WRITE_END], &msg, sizeof(struct worker_message), 0);
338 log_debug("seq %llu processed with %i", udev_device_get_seqnum(dev), err);
340 udev_device_unref(dev);
343 if (udev_event->sigterm) {
344 udev_event_unref(udev_event);
348 udev_event_unref(udev_event);
350 /* wait for more device messages from main udevd, or term signal */
351 while (dev == NULL) {
352 struct epoll_event ev[4];
356 fdcount = epoll_wait(fd_ep, ev, ELEMENTSOF(ev), -1);
360 log_error("failed to poll: %m");
364 for (i = 0; i < fdcount; i++) {
365 if (ev[i].data.fd == fd_monitor && ev[i].events & EPOLLIN) {
366 dev = udev_monitor_receive_device(worker_monitor);
368 } else if (ev[i].data.fd == fd_signal && ev[i].events & EPOLLIN) {
369 struct signalfd_siginfo fdsi;
372 size = read(fd_signal, &fdsi, sizeof(struct signalfd_siginfo));
373 if (size != sizeof(struct signalfd_siginfo))
375 switch (fdsi.ssi_signo) {
384 udev_device_unref(dev);
385 safe_close(fd_signal);
388 close(worker_watch[WRITE_END]);
389 udev_rules_unref(rules);
390 udev_builtin_exit(udev);
391 udev_monitor_unref(worker_monitor);
397 udev_monitor_unref(worker_monitor);
398 event->state = EVENT_QUEUED;
400 log_error("fork of child failed: %m");
403 /* close monitor, but keep address around */
404 udev_monitor_disconnect(worker_monitor);
405 worker->monitor = worker_monitor;
407 worker->state = WORKER_RUNNING;
408 worker->event_start_usec = now(CLOCK_MONOTONIC);
409 worker->event = event;
410 event->state = EVENT_RUNNING;
411 udev_list_node_append(&worker->node, &worker_list);
413 log_debug("seq %llu forked new worker [%u]", udev_device_get_seqnum(event->dev), pid);
418 static void event_run(struct event *event)
420 struct udev_list_node *loop;
422 udev_list_node_foreach(loop, &worker_list) {
423 struct worker *worker = node_to_worker(loop);
426 if (worker->state != WORKER_IDLE)
429 count = udev_monitor_send_device(monitor, worker->monitor, event->dev);
431 log_error("worker [%u] did not accept message %zi (%m), kill it", worker->pid, count);
432 kill(worker->pid, SIGKILL);
433 worker->state = WORKER_KILLED;
437 worker->event = event;
438 worker->state = WORKER_RUNNING;
439 worker->event_start_usec = now(CLOCK_MONOTONIC);
440 event->state = EVENT_RUNNING;
444 if (children >= children_max) {
445 if (children_max > 1)
446 log_debug("maximum number (%i) of children reached", children);
450 /* start new worker and pass initial device */
454 static int event_queue_insert(struct udev_device *dev)
458 event = new0(struct event, 1);
462 event->udev = udev_device_get_udev(dev);
464 event->seqnum = udev_device_get_seqnum(dev);
465 event->devpath = udev_device_get_devpath(dev);
466 event->devpath_len = strlen(event->devpath);
467 event->devpath_old = udev_device_get_devpath_old(dev);
468 event->devnum = udev_device_get_devnum(dev);
469 event->is_block = streq("block", udev_device_get_subsystem(dev));
470 event->ifindex = udev_device_get_ifindex(dev);
472 if (streq(udev_device_get_subsystem(dev), "firmware"))
473 event->nodelay = true;
476 log_debug("seq %llu queued, '%s' '%s'", udev_device_get_seqnum(dev),
477 udev_device_get_action(dev), udev_device_get_subsystem(dev));
479 event->state = EVENT_QUEUED;
480 udev_list_node_append(&event->node, &event_list);
484 static void worker_kill(struct udev *udev)
486 struct udev_list_node *loop;
488 udev_list_node_foreach(loop, &worker_list) {
489 struct worker *worker = node_to_worker(loop);
491 if (worker->state == WORKER_KILLED)
494 worker->state = WORKER_KILLED;
495 kill(worker->pid, SIGTERM);
499 /* lookup event for identical, parent, child device */
500 static bool is_devpath_busy(struct event *event)
502 struct udev_list_node *loop;
505 /* check if queue contains events we depend on */
506 udev_list_node_foreach(loop, &event_list) {
507 struct event *loop_event = node_to_event(loop);
509 /* we already found a later event, earlier can not block us, no need to check again */
510 if (loop_event->seqnum < event->delaying_seqnum)
513 /* event we checked earlier still exists, no need to check again */
514 if (loop_event->seqnum == event->delaying_seqnum)
517 /* found ourself, no later event can block us */
518 if (loop_event->seqnum >= event->seqnum)
521 /* check major/minor */
522 if (major(event->devnum) != 0 && event->devnum == loop_event->devnum && event->is_block == loop_event->is_block)
525 /* check network device ifindex */
526 if (event->ifindex != 0 && event->ifindex == loop_event->ifindex)
529 /* check our old name */
530 if (event->devpath_old != NULL && streq(loop_event->devpath, event->devpath_old)) {
531 event->delaying_seqnum = loop_event->seqnum;
535 /* compare devpath */
536 common = MIN(loop_event->devpath_len, event->devpath_len);
538 /* one devpath is contained in the other? */
539 if (memcmp(loop_event->devpath, event->devpath, common) != 0)
542 /* identical device event found */
543 if (loop_event->devpath_len == event->devpath_len) {
544 /* devices names might have changed/swapped in the meantime */
545 if (major(event->devnum) != 0 && (event->devnum != loop_event->devnum || event->is_block != loop_event->is_block))
547 if (event->ifindex != 0 && event->ifindex != loop_event->ifindex)
549 event->delaying_seqnum = loop_event->seqnum;
554 /* allow to bypass the dependency tracking */
559 /* parent device event found */
560 if (event->devpath[common] == '/') {
561 event->delaying_seqnum = loop_event->seqnum;
565 /* child device event found */
566 if (loop_event->devpath[common] == '/') {
567 event->delaying_seqnum = loop_event->seqnum;
571 /* no matching device */
578 static void event_queue_start(struct udev *udev)
580 struct udev_list_node *loop;
582 udev_list_node_foreach(loop, &event_list) {
583 struct event *event = node_to_event(loop);
585 if (event->state != EVENT_QUEUED)
588 /* do not start event if parent or child event is still running */
589 if (is_devpath_busy(event))
596 static void event_queue_cleanup(struct udev *udev, enum event_state match_type)
598 struct udev_list_node *loop, *tmp;
600 udev_list_node_foreach_safe(loop, tmp, &event_list) {
601 struct event *event = node_to_event(loop);
603 if (match_type != EVENT_UNDEF && match_type != event->state)
606 event_queue_delete(event);
610 static void worker_returned(int fd_worker)
613 struct worker_message msg;
615 struct udev_list_node *loop;
617 size = recv(fd_worker, &msg, sizeof(struct worker_message), MSG_DONTWAIT);
618 if (size != sizeof(struct worker_message))
621 /* lookup worker who sent the signal */
622 udev_list_node_foreach(loop, &worker_list) {
623 struct worker *worker = node_to_worker(loop);
625 if (worker->pid != msg.pid)
628 /* worker returned */
630 worker->event->exitcode = msg.exitcode;
631 event_queue_delete(worker->event);
632 worker->event = NULL;
634 if (worker->state != WORKER_KILLED)
635 worker->state = WORKER_IDLE;
636 worker_unref(worker);
642 /* receive the udevd message from userspace */
643 static struct udev_ctrl_connection *handle_ctrl_msg(struct udev_ctrl *uctrl)
645 struct udev *udev = udev_ctrl_get_udev(uctrl);
646 struct udev_ctrl_connection *ctrl_conn;
647 struct udev_ctrl_msg *ctrl_msg = NULL;
651 ctrl_conn = udev_ctrl_get_connection(uctrl);
652 if (ctrl_conn == NULL)
655 ctrl_msg = udev_ctrl_receive_msg(ctrl_conn);
656 if (ctrl_msg == NULL)
659 i = udev_ctrl_get_set_log_level(ctrl_msg);
661 log_debug("udevd message (SET_LOG_LEVEL) received, log_priority=%i", i);
662 log_set_max_level(i);
663 udev_set_log_priority(udev, i);
667 if (udev_ctrl_get_stop_exec_queue(ctrl_msg) > 0) {
668 log_debug("udevd message (STOP_EXEC_QUEUE) received");
669 stop_exec_queue = true;
672 if (udev_ctrl_get_start_exec_queue(ctrl_msg) > 0) {
673 log_debug("udevd message (START_EXEC_QUEUE) received");
674 stop_exec_queue = false;
677 if (udev_ctrl_get_reload(ctrl_msg) > 0) {
678 log_debug("udevd message (RELOAD) received");
682 str = udev_ctrl_get_set_env(ctrl_msg);
690 val = strchr(key, '=');
694 if (val[0] == '\0') {
695 log_debug("udevd message (ENV) received, unset '%s'", key);
696 udev_add_property(udev, key, NULL);
698 log_debug("udevd message (ENV) received, set '%s=%s'", key, val);
699 udev_add_property(udev, key, val);
702 log_error("wrong key format '%s'", key);
709 i = udev_ctrl_get_set_children_max(ctrl_msg);
711 log_debug("udevd message (SET_MAX_CHILDREN) received, children_max=%i", i);
715 if (udev_ctrl_get_ping(ctrl_msg) > 0)
716 log_debug("udevd message (SYNC) received");
718 if (udev_ctrl_get_exit(ctrl_msg) > 0) {
719 log_debug("udevd message (EXIT) received");
721 /* keep reference to block the client until we exit */
722 udev_ctrl_connection_ref(ctrl_conn);
725 udev_ctrl_msg_unref(ctrl_msg);
726 return udev_ctrl_connection_unref(ctrl_conn);
729 static int synthesize_change(struct udev_device *dev) {
730 char filename[UTIL_PATH_SIZE];
733 if (streq_ptr("block", udev_device_get_subsystem(dev)) &&
734 streq_ptr("disk", udev_device_get_devtype(dev)) &&
735 !startswith(udev_device_get_sysname(dev), "dm-")) {
736 bool part_table_read = false;
737 bool has_partitions = false;
739 struct udev *udev = udev_device_get_udev(dev);
740 _cleanup_udev_enumerate_unref_ struct udev_enumerate *e = NULL;
741 struct udev_list_entry *item;
744 * Try to re-read the partition table. This only succeeds if
745 * none of the devices is busy. The kernel returns 0 if no
746 * partition table is found, and we will not get an event for
749 fd = open(udev_device_get_devnode(dev), O_RDONLY|O_CLOEXEC|O_NOFOLLOW|O_NONBLOCK);
751 r = flock(fd, LOCK_EX|LOCK_NB);
753 r = ioctl(fd, BLKRRPART, 0);
757 part_table_read = true;
760 /* search for partitions */
761 e = udev_enumerate_new(udev);
765 r = udev_enumerate_add_match_parent(e, dev);
769 r = udev_enumerate_add_match_subsystem(e, "block");
773 r = udev_enumerate_scan_devices(e);
777 udev_list_entry_foreach(item, udev_enumerate_get_list_entry(e)) {
778 _cleanup_udev_device_unref_ struct udev_device *d = NULL;
780 d = udev_device_new_from_syspath(udev, udev_list_entry_get_name(item));
784 if (!streq_ptr("partition", udev_device_get_devtype(d)))
787 has_partitions = true;
792 * We have partitions and re-read the table, the kernel already sent
793 * out a "change" event for the disk, and "remove/add" for all
796 if (part_table_read && has_partitions)
800 * We have partitions but re-reading the partition table did not
801 * work, synthesize "change" for the disk and all partitions.
803 log_debug("device %s closed, synthesising 'change'", udev_device_get_devnode(dev));
804 strscpyl(filename, sizeof(filename), udev_device_get_syspath(dev), "/uevent", NULL);
805 write_string_file(filename, "change");
807 udev_list_entry_foreach(item, udev_enumerate_get_list_entry(e)) {
808 _cleanup_udev_device_unref_ struct udev_device *d = NULL;
810 d = udev_device_new_from_syspath(udev, udev_list_entry_get_name(item));
814 if (!streq_ptr("partition", udev_device_get_devtype(d)))
817 log_debug("device %s closed, synthesising partition '%s' 'change'",
818 udev_device_get_devnode(dev), udev_device_get_devnode(d));
819 strscpyl(filename, sizeof(filename), udev_device_get_syspath(d), "/uevent", NULL);
820 write_string_file(filename, "change");
826 log_debug("device %s closed, synthesising 'change'", udev_device_get_devnode(dev));
827 strscpyl(filename, sizeof(filename), udev_device_get_syspath(dev), "/uevent", NULL);
828 write_string_file(filename, "change");
833 static int handle_inotify(struct udev *udev)
837 struct inotify_event *ev;
840 r = ioctl(fd_inotify, FIONREAD, &nbytes);
841 if (r < 0 || nbytes <= 0)
844 buf = malloc(nbytes);
846 log_error("error getting buffer for inotify");
850 nbytes = read(fd_inotify, buf, nbytes);
852 for (pos = 0; pos < nbytes; pos += sizeof(struct inotify_event) + ev->len) {
853 struct udev_device *dev;
855 ev = (struct inotify_event *)(buf + pos);
856 dev = udev_watch_lookup(udev, ev->wd);
860 log_debug("inotify event: %x for %s", ev->mask, udev_device_get_devnode(dev));
861 if (ev->mask & IN_CLOSE_WRITE)
862 synthesize_change(dev);
863 else if (ev->mask & IN_IGNORED)
864 udev_watch_end(udev, dev);
866 udev_device_unref(dev);
873 static void handle_signal(struct udev *udev, int signo)
884 struct udev_list_node *loop, *tmp;
886 pid = waitpid(-1, &status, WNOHANG);
890 udev_list_node_foreach_safe(loop, tmp, &worker_list) {
891 struct worker *worker = node_to_worker(loop);
893 if (worker->pid != pid)
895 log_debug("worker [%u] exit", pid);
897 if (WIFEXITED(status)) {
898 if (WEXITSTATUS(status) != 0)
899 log_error("worker [%u] exit with return code %i",
900 pid, WEXITSTATUS(status));
901 } else if (WIFSIGNALED(status)) {
902 log_error("worker [%u] terminated by signal %i (%s)",
903 pid, WTERMSIG(status), strsignal(WTERMSIG(status)));
904 } else if (WIFSTOPPED(status)) {
905 log_error("worker [%u] stopped", pid);
906 } else if (WIFCONTINUED(status)) {
907 log_error("worker [%u] continued", pid);
909 log_error("worker [%u] exit with status 0x%04x", pid, status);
912 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
914 log_error("worker [%u] failed while handling '%s'",
915 pid, worker->event->devpath);
916 worker->event->exitcode = -32;
917 event_queue_delete(worker->event);
919 /* drop reference taken for state 'running' */
920 worker_unref(worker);
923 worker_unref(worker);
934 static int systemd_fds(struct udev *udev, int *rctrl, int *rnetlink)
936 int ctrl = -1, netlink = -1;
939 n = sd_listen_fds(true);
943 for (fd = SD_LISTEN_FDS_START; fd < n + SD_LISTEN_FDS_START; fd++) {
944 if (sd_is_socket(fd, AF_LOCAL, SOCK_SEQPACKET, -1)) {
951 if (sd_is_socket(fd, AF_NETLINK, SOCK_RAW, -1)) {
961 if (ctrl < 0 || netlink < 0)
964 log_debug("ctrl=%i netlink=%i", ctrl, netlink);
971 * read the kernel commandline, in case we need to get into debug mode
972 * udev.log-priority=<level> syslog priority
973 * udev.children-max=<number of workers> events are fully serialized if set to 1
974 * udev.exec-delay=<number of seconds> delay execution of every executed program
976 static void kernel_cmdline_options(struct udev *udev)
978 _cleanup_free_ char *line = NULL;
983 r = proc_cmdline(&line);
985 log_warning("Failed to read /proc/cmdline, ignoring: %s", strerror(-r));
989 FOREACH_WORD_QUOTED(w, l, line, state) {
996 /* accept the same options for the initrd, prefixed with "rd." */
997 if (in_initrd() && startswith(s, "rd."))
1002 if (startswith(opt, "udev.log-priority=")) {
1005 prio = util_log_priority(opt + 18);
1006 log_set_max_level(prio);
1007 udev_set_log_priority(udev, prio);
1008 } else if (startswith(opt, "udev.children-max=")) {
1009 children_max = strtoul(opt + 18, NULL, 0);
1010 } else if (startswith(opt, "udev.exec-delay=")) {
1011 exec_delay = strtoul(opt + 16, NULL, 0);
1018 int main(int argc, char *argv[])
1022 int daemonize = false;
1023 int resolve_names = 1;
1024 static const struct option options[] = {
1025 { "daemon", no_argument, NULL, 'd' },
1026 { "debug", no_argument, NULL, 'D' },
1027 { "children-max", required_argument, NULL, 'c' },
1028 { "exec-delay", required_argument, NULL, 'e' },
1029 { "resolve-names", required_argument, NULL, 'N' },
1030 { "help", no_argument, NULL, 'h' },
1031 { "version", no_argument, NULL, 'V' },
1035 int fd_netlink = -1;
1037 struct epoll_event ep_ctrl, ep_inotify, ep_signal, ep_netlink, ep_worker;
1038 struct udev_ctrl_connection *ctrl_conn = NULL;
1045 log_set_target(LOG_TARGET_AUTO);
1046 log_parse_environment();
1049 udev_set_log_fn(udev, udev_main_log);
1050 log_set_max_level(udev_get_log_priority(udev));
1052 log_debug("version %s", VERSION);
1058 option = getopt_long(argc, argv, "c:de:DtN:hV", options, NULL);
1067 children_max = strtoul(optarg, NULL, 0);
1070 exec_delay = strtoul(optarg, NULL, 0);
1074 log_set_max_level(LOG_DEBUG);
1075 udev_set_log_priority(udev, LOG_DEBUG);
1078 if (streq(optarg, "early")) {
1080 } else if (streq(optarg, "late")) {
1082 } else if (streq(optarg, "never")) {
1085 fprintf(stderr, "resolve-names must be early, late or never\n");
1086 log_error("resolve-names must be early, late or never");
1091 printf("Usage: udevd OPTIONS\n"
1094 " --children-max=<maximum number of workers>\n"
1095 " --exec-delay=<seconds to wait before executing RUN=>\n"
1096 " --resolve-names=early|late|never\n"
1102 printf("%s\n", VERSION);
1109 kernel_cmdline_options(udev);
1111 if (getuid() != 0) {
1112 fprintf(stderr, "root privileges required\n");
1113 log_error("root privileges required");
1117 /* set umask before creating any file/directory */
1121 mkdir("/run/udev", 0755);
1125 /* before opening new files, make sure std{in,out,err} fds are in a sane state */
1129 fd = open("/dev/null", O_RDWR);
1131 if (write(STDOUT_FILENO, 0, 0) < 0)
1132 dup2(fd, STDOUT_FILENO);
1133 if (write(STDERR_FILENO, 0, 0) < 0)
1134 dup2(fd, STDERR_FILENO);
1135 if (fd > STDERR_FILENO)
1138 fprintf(stderr, "cannot open /dev/null\n");
1139 log_error("cannot open /dev/null");
1143 if (systemd_fds(udev, &fd_ctrl, &fd_netlink) >= 0) {
1144 /* get control and netlink socket from systemd */
1145 udev_ctrl = udev_ctrl_new_from_fd(udev, fd_ctrl);
1146 if (udev_ctrl == NULL) {
1147 log_error("error taking over udev control socket");
1152 monitor = udev_monitor_new_from_netlink_fd(udev, "kernel", fd_netlink);
1153 if (monitor == NULL) {
1154 log_error("error taking over netlink socket");
1159 /* get our own cgroup, we regularly kill everything udev has left behind */
1160 if (cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, 0, &udev_cgroup) < 0)
1163 /* open control and netlink socket */
1164 udev_ctrl = udev_ctrl_new(udev);
1165 if (udev_ctrl == NULL) {
1166 fprintf(stderr, "error initializing udev control socket");
1167 log_error("error initializing udev control socket");
1171 fd_ctrl = udev_ctrl_get_fd(udev_ctrl);
1173 monitor = udev_monitor_new_from_netlink(udev, "kernel");
1174 if (monitor == NULL) {
1175 fprintf(stderr, "error initializing netlink socket\n");
1176 log_error("error initializing netlink socket");
1180 fd_netlink = udev_monitor_get_fd(monitor);
1183 if (udev_monitor_enable_receiving(monitor) < 0) {
1184 fprintf(stderr, "error binding netlink socket\n");
1185 log_error("error binding netlink socket");
1190 if (udev_ctrl_enable_receiving(udev_ctrl) < 0) {
1191 fprintf(stderr, "error binding udev control socket\n");
1192 log_error("error binding udev control socket");
1197 udev_monitor_set_receive_buffer_size(monitor, 128 * 1024 * 1024);
1207 log_error("fork of daemon failed: %m");
1212 goto exit_daemonize;
1217 write_string_file("/proc/self/oom_score_adj", "-1000");
1219 sd_notify(1, "READY=1");
1222 print_kmsg("starting version " VERSION "\n");
1227 fd = open("/dev/null", O_RDWR);
1229 dup2(fd, STDIN_FILENO);
1230 dup2(fd, STDOUT_FILENO);
1231 dup2(fd, STDERR_FILENO);
1236 fd_inotify = udev_watch_init(udev);
1237 if (fd_inotify < 0) {
1238 fprintf(stderr, "error initializing inotify\n");
1239 log_error("error initializing inotify");
1243 udev_watch_restore(udev);
1245 /* block and listen to all signals on signalfd */
1247 sigprocmask(SIG_SETMASK, &mask, &sigmask_orig);
1248 fd_signal = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC);
1249 if (fd_signal < 0) {
1250 fprintf(stderr, "error creating signalfd\n");
1251 log_error("error creating signalfd");
1256 /* unnamed socket from workers to the main daemon */
1257 if (socketpair(AF_LOCAL, SOCK_DGRAM|SOCK_CLOEXEC, 0, worker_watch) < 0) {
1258 fprintf(stderr, "error creating socketpair\n");
1259 log_error("error creating socketpair");
1263 fd_worker = worker_watch[READ_END];
1265 udev_builtin_init(udev);
1267 rules = udev_rules_new(udev, resolve_names);
1268 if (rules == NULL) {
1269 log_error("error reading rules");
1273 memzero(&ep_ctrl, sizeof(struct epoll_event));
1274 ep_ctrl.events = EPOLLIN;
1275 ep_ctrl.data.fd = fd_ctrl;
1277 memzero(&ep_inotify, sizeof(struct epoll_event));
1278 ep_inotify.events = EPOLLIN;
1279 ep_inotify.data.fd = fd_inotify;
1281 memzero(&ep_signal, sizeof(struct epoll_event));
1282 ep_signal.events = EPOLLIN;
1283 ep_signal.data.fd = fd_signal;
1285 memzero(&ep_netlink, sizeof(struct epoll_event));
1286 ep_netlink.events = EPOLLIN;
1287 ep_netlink.data.fd = fd_netlink;
1289 memzero(&ep_worker, sizeof(struct epoll_event));
1290 ep_worker.events = EPOLLIN;
1291 ep_worker.data.fd = fd_worker;
1293 fd_ep = epoll_create1(EPOLL_CLOEXEC);
1295 log_error("error creating epoll fd: %m");
1298 if (epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_ctrl, &ep_ctrl) < 0 ||
1299 epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_inotify, &ep_inotify) < 0 ||
1300 epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_signal, &ep_signal) < 0 ||
1301 epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_netlink, &ep_netlink) < 0 ||
1302 epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_worker, &ep_worker) < 0) {
1303 log_error("fail to add fds to epoll: %m");
1307 if (children_max <= 0) {
1312 if (sched_getaffinity(0, sizeof (cpu_set), &cpu_set) == 0) {
1313 children_max += CPU_COUNT(&cpu_set) * 2;
1316 log_debug("set children_max to %u", children_max);
1318 rc = udev_rules_apply_static_dev_perms(rules);
1320 log_error("failed to apply permissions on static device nodes - %s", strerror(-rc));
1322 udev_list_node_init(&event_list);
1323 udev_list_node_init(&worker_list);
1326 static usec_t last_usec;
1327 struct epoll_event ev[8];
1330 bool is_worker, is_signal, is_inotify, is_netlink, is_ctrl;
1334 /* close sources of new events and discard buffered events */
1336 epoll_ctl(fd_ep, EPOLL_CTL_DEL, fd_ctrl, NULL);
1339 if (monitor != NULL) {
1340 epoll_ctl(fd_ep, EPOLL_CTL_DEL, fd_netlink, NULL);
1341 udev_monitor_unref(monitor);
1344 if (fd_inotify >= 0) {
1345 epoll_ctl(fd_ep, EPOLL_CTL_DEL, fd_inotify, NULL);
1350 /* discard queued events and kill workers */
1351 event_queue_cleanup(udev, EVENT_QUEUED);
1354 /* exit after all has cleaned up */
1355 if (udev_list_node_is_empty(&event_list) && children == 0)
1358 /* timeout at exit for workers to finish */
1359 timeout = 30 * MSEC_PER_SEC;
1360 } else if (udev_list_node_is_empty(&event_list) && children == 0) {
1364 /* cleanup possible left-over processes in our cgroup */
1366 cg_kill(SYSTEMD_CGROUP_CONTROLLER, udev_cgroup, SIGKILL, false, true, NULL);
1368 /* kill idle or hanging workers */
1369 timeout = 3 * MSEC_PER_SEC;
1372 /* tell settle that we are busy or idle */
1373 if (!udev_list_node_is_empty(&event_list)) {
1376 fd = open("/run/udev/queue", O_WRONLY|O_CREAT|O_CLOEXEC|O_TRUNC|O_NOFOLLOW, 0444);
1380 unlink("/run/udev/queue");
1383 fdcount = epoll_wait(fd_ep, ev, ELEMENTSOF(ev), timeout);
1388 struct udev_list_node *loop;
1392 log_error("timeout, giving up waiting for workers to finish");
1396 /* kill idle workers */
1397 if (udev_list_node_is_empty(&event_list)) {
1398 log_debug("cleanup idle workers");
1402 /* check for hanging events */
1403 udev_list_node_foreach(loop, &worker_list) {
1404 struct worker *worker = node_to_worker(loop);
1406 if (worker->state != WORKER_RUNNING)
1409 if ((now(CLOCK_MONOTONIC) - worker->event_start_usec) > 30 * USEC_PER_SEC) {
1410 log_error("worker [%u] %s timeout; kill it", worker->pid,
1411 worker->event ? worker->event->devpath : "<idle>");
1412 kill(worker->pid, SIGKILL);
1413 worker->state = WORKER_KILLED;
1415 /* drop reference taken for state 'running' */
1416 worker_unref(worker);
1417 if (worker->event) {
1418 log_error("seq %llu '%s' killed", udev_device_get_seqnum(worker->event->dev), worker->event->devpath);
1419 worker->event->exitcode = -64;
1420 event_queue_delete(worker->event);
1421 worker->event = NULL;
1428 is_worker = is_signal = is_inotify = is_netlink = is_ctrl = false;
1429 for (i = 0; i < fdcount; i++) {
1430 if (ev[i].data.fd == fd_worker && ev[i].events & EPOLLIN)
1432 else if (ev[i].data.fd == fd_netlink && ev[i].events & EPOLLIN)
1434 else if (ev[i].data.fd == fd_signal && ev[i].events & EPOLLIN)
1436 else if (ev[i].data.fd == fd_inotify && ev[i].events & EPOLLIN)
1438 else if (ev[i].data.fd == fd_ctrl && ev[i].events & EPOLLIN)
1442 /* check for changed config, every 3 seconds at most */
1443 if ((now(CLOCK_MONOTONIC) - last_usec) > 3 * USEC_PER_SEC) {
1444 if (udev_rules_check_timestamp(rules))
1446 if (udev_builtin_validate(udev))
1449 last_usec = now(CLOCK_MONOTONIC);
1452 /* reload requested, HUP signal received, rules changed, builtin changed */
1455 rules = udev_rules_unref(rules);
1456 udev_builtin_exit(udev);
1460 /* event has finished */
1462 worker_returned(fd_worker);
1465 struct udev_device *dev;
1467 dev = udev_monitor_receive_device(monitor);
1469 udev_device_set_usec_initialized(dev, now(CLOCK_MONOTONIC));
1470 if (event_queue_insert(dev) < 0)
1471 udev_device_unref(dev);
1475 /* start new events */
1476 if (!udev_list_node_is_empty(&event_list) && !udev_exit && !stop_exec_queue) {
1477 udev_builtin_init(udev);
1479 rules = udev_rules_new(udev, resolve_names);
1481 event_queue_start(udev);
1485 struct signalfd_siginfo fdsi;
1488 size = read(fd_signal, &fdsi, sizeof(struct signalfd_siginfo));
1489 if (size == sizeof(struct signalfd_siginfo))
1490 handle_signal(udev, fdsi.ssi_signo);
1493 /* we are shutting down, the events below are not handled anymore */
1497 /* device node watch */
1499 handle_inotify(udev);
1502 * This needs to be after the inotify handling, to make sure,
1503 * that the ping is send back after the possibly generated
1504 * "change" events by the inotify device node watch.
1506 * A single time we may receive a client connection which we need to
1507 * keep open to block the client. It will be closed right before we
1511 ctrl_conn = handle_ctrl_msg(udev_ctrl);
1516 udev_ctrl_cleanup(udev_ctrl);
1517 unlink("/run/udev/queue");
1521 worker_list_cleanup(udev);
1522 event_queue_cleanup(udev, EVENT_UNDEF);
1523 udev_rules_unref(rules);
1524 udev_builtin_exit(udev);
1527 if (worker_watch[READ_END] >= 0)
1528 close(worker_watch[READ_END]);
1529 if (worker_watch[WRITE_END] >= 0)
1530 close(worker_watch[WRITE_END]);
1531 udev_monitor_unref(monitor);
1532 udev_ctrl_connection_unref(ctrl_conn);
1533 udev_ctrl_unref(udev_ctrl);