2 * Copyright (C) 2004-2011 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>
38 #include <sys/signalfd.h>
39 #include <sys/epoll.h>
43 #include <sys/ioctl.h>
44 #include <sys/inotify.h>
45 #include <sys/utsname.h>
48 #include "sd-daemon.h"
52 void udev_main_log(struct udev *udev, int priority,
53 const char *file, int line, const char *fn,
54 const char *format, va_list args)
60 vsnprintf(buf, sizeof(buf), format, args);
61 clock_gettime(CLOCK_MONOTONIC, &ts);
62 fprintf(stderr, "[%llu.%06u] [%u] %s: %s",
63 (unsigned long long) ts.tv_sec, (unsigned int) ts.tv_nsec/1000,
64 (int) getpid(), fn, buf);
66 vsyslog(priority, format, args);
70 static struct udev_rules *rules;
71 static struct udev_queue_export *udev_queue_export;
72 static struct udev_ctrl *udev_ctrl;
73 static struct udev_monitor *monitor;
74 static int worker_watch[2] = { -1, -1 };
75 static int fd_signal = -1;
76 static int fd_ep = -1;
77 static int fd_inotify = -1;
78 static bool stop_exec_queue;
81 static int children_max;
82 static int exec_delay;
83 static sigset_t sigmask_orig;
84 static UDEV_LIST(event_list);
85 static UDEV_LIST(worker_list);
86 static bool udev_exit;
95 struct udev_list_node node;
97 struct udev_device *dev;
98 enum event_state state;
100 unsigned long long int delaying_seqnum;
101 unsigned long long int seqnum;
104 const char *devpath_old;
110 static struct event *node_to_event(struct udev_list_node *node)
114 event = (char *)node;
115 event -= offsetof(struct event, node);
116 return (struct event *)event;
119 static void event_queue_cleanup(struct udev *udev, enum event_state type);
129 struct udev_list_node node;
133 struct udev_monitor *monitor;
134 enum worker_state state;
138 /* passed from worker to main process */
139 struct worker_message {
144 static struct worker *node_to_worker(struct udev_list_node *node)
148 worker = (char *)node;
149 worker -= offsetof(struct worker, node);
150 return (struct worker *)worker;
153 static void event_queue_delete(struct event *event, bool export)
155 udev_list_node_remove(&event->node);
158 udev_queue_export_device_finished(udev_queue_export, event->dev);
159 info(event->udev, "seq %llu done with %i\n", udev_device_get_seqnum(event->dev), event->exitcode);
161 udev_device_unref(event->dev);
165 static struct worker *worker_ref(struct worker *worker)
171 static void worker_cleanup(struct worker *worker)
173 udev_list_node_remove(&worker->node);
174 udev_monitor_unref(worker->monitor);
179 static void worker_unref(struct worker *worker)
182 if (worker->refcount > 0)
184 info(worker->udev, "worker [%u] cleaned up\n", worker->pid);
185 worker_cleanup(worker);
188 static void worker_list_cleanup(struct udev *udev)
190 struct udev_list_node *loop, *tmp;
192 udev_list_node_foreach_safe(loop, tmp, &worker_list) {
193 struct worker *worker = node_to_worker(loop);
195 worker_cleanup(worker);
199 static void worker_new(struct event *event)
201 struct udev *udev = event->udev;
202 struct worker *worker;
203 struct udev_monitor *worker_monitor;
206 /* listen for new events */
207 worker_monitor = udev_monitor_new_from_netlink(udev, NULL);
208 if (worker_monitor == NULL)
210 /* allow the main daemon netlink address to send devices to the worker */
211 udev_monitor_allow_unicast_sender(worker_monitor, monitor);
212 udev_monitor_enable_receiving(worker_monitor);
214 worker = calloc(1, sizeof(struct worker));
215 if (worker == NULL) {
216 udev_monitor_unref(worker_monitor);
219 /* worker + event reference */
220 worker->refcount = 2;
226 struct udev_device *dev = NULL;
228 struct epoll_event ep_signal, ep_monitor;
230 int rc = EXIT_SUCCESS;
232 /* move initial device from queue */
237 worker_list_cleanup(udev);
238 event_queue_cleanup(udev, EVENT_UNDEF);
239 udev_queue_export_unref(udev_queue_export);
240 udev_monitor_unref(monitor);
241 udev_ctrl_unref(udev_ctrl);
244 close(worker_watch[READ_END]);
247 fd_signal = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC);
249 err(udev, "error creating signalfd %m\n");
254 fd_ep = epoll_create1(EPOLL_CLOEXEC);
256 err(udev, "error creating epoll fd: %m\n");
261 memset(&ep_signal, 0, sizeof(struct epoll_event));
262 ep_signal.events = EPOLLIN;
263 ep_signal.data.fd = fd_signal;
265 fd_monitor = udev_monitor_get_fd(worker_monitor);
266 memset(&ep_monitor, 0, sizeof(struct epoll_event));
267 ep_monitor.events = EPOLLIN;
268 ep_monitor.data.fd = fd_monitor;
270 if (epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_signal, &ep_signal) < 0 ||
271 epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_monitor, &ep_monitor) < 0) {
272 err(udev, "fail to add fds to epoll: %m\n");
277 /* request TERM signal if parent exits */
278 prctl(PR_SET_PDEATHSIG, SIGTERM);
281 struct udev_event *udev_event;
282 struct worker_message msg;
285 info(udev, "seq %llu running\n", udev_device_get_seqnum(dev));
286 udev_event = udev_event_new(dev);
287 if (udev_event == NULL) {
292 /* needed for SIGCHLD/SIGTERM in spawn() */
293 udev_event->fd_signal = fd_signal;
296 udev_event->exec_delay = exec_delay;
298 /* apply rules, create node, symlinks */
299 err = udev_event_execute_rules(udev_event, rules, &sigmask_orig);
302 udev_event_execute_run(udev_event, &sigmask_orig);
304 /* apply/restore inotify watch */
305 if (err == 0 && udev_event->inotify_watch) {
306 udev_watch_begin(udev, dev);
307 udev_device_update_db(dev);
310 /* send processed event back to libudev listeners */
311 udev_monitor_send_device(worker_monitor, NULL, dev);
313 /* send udevd the result of the event execution */
314 memset(&msg, 0, sizeof(struct worker_message));
318 send(worker_watch[WRITE_END], &msg, sizeof(struct worker_message), 0);
320 info(udev, "seq %llu processed with %i\n", udev_device_get_seqnum(dev), err);
322 udev_device_unref(dev);
325 if (udev_event->sigterm) {
326 udev_event_unref(udev_event);
330 udev_event_unref(udev_event);
332 /* wait for more device messages from main udevd, or term signal */
333 while (dev == NULL) {
334 struct epoll_event ev[4];
338 fdcount = epoll_wait(fd_ep, ev, ARRAY_SIZE(ev), -1);
343 err(udev, "failed to poll: %m\n");
347 for (i = 0; i < fdcount; i++) {
348 if (ev[i].data.fd == fd_monitor && ev[i].events & EPOLLIN) {
349 dev = udev_monitor_receive_device(worker_monitor);
351 } else if (ev[i].data.fd == fd_signal && ev[i].events & EPOLLIN) {
352 struct signalfd_siginfo fdsi;
355 size = read(fd_signal, &fdsi, sizeof(struct signalfd_siginfo));
356 if (size != sizeof(struct signalfd_siginfo))
358 switch (fdsi.ssi_signo) {
367 udev_device_unref(dev);
373 close(worker_watch[WRITE_END]);
374 udev_rules_unref(rules);
375 udev_monitor_unref(worker_monitor);
381 udev_monitor_unref(worker_monitor);
382 event->state = EVENT_QUEUED;
384 err(udev, "fork of child failed: %m\n");
387 /* close monitor, but keep address around */
388 udev_monitor_disconnect(worker_monitor);
389 worker->monitor = worker_monitor;
391 worker->state = WORKER_RUNNING;
392 worker->event = event;
393 event->state = EVENT_RUNNING;
394 udev_list_node_append(&worker->node, &worker_list);
396 info(udev, "seq %llu forked new worker [%u]\n", udev_device_get_seqnum(event->dev), pid);
401 static void event_run(struct event *event)
403 struct udev_list_node *loop;
405 udev_list_node_foreach(loop, &worker_list) {
406 struct worker *worker = node_to_worker(loop);
409 if (worker->state != WORKER_IDLE)
412 count = udev_monitor_send_device(monitor, worker->monitor, event->dev);
414 err(event->udev, "worker [%u] did not accept message %zi (%m), kill it\n", worker->pid, count);
415 kill(worker->pid, SIGKILL);
416 worker->state = WORKER_KILLED;
420 worker->event = event;
421 worker->state = WORKER_RUNNING;
422 event->state = EVENT_RUNNING;
426 if (children >= children_max) {
427 if (children_max > 1)
428 info(event->udev, "maximum number (%i) of children reached\n", children);
432 /* start new worker and pass initial device */
436 static int event_queue_insert(struct udev_device *dev)
440 event = calloc(1, sizeof(struct event));
444 event->udev = udev_device_get_udev(dev);
446 event->seqnum = udev_device_get_seqnum(dev);
447 event->devpath = udev_device_get_devpath(dev);
448 event->devpath_len = strlen(event->devpath);
449 event->devpath_old = udev_device_get_devpath_old(dev);
450 event->devnum = udev_device_get_devnum(dev);
451 event->is_block = (strcmp("block", udev_device_get_subsystem(dev)) == 0);
452 event->ifindex = udev_device_get_ifindex(dev);
454 udev_queue_export_device_queued(udev_queue_export, dev);
455 info(event->udev, "seq %llu queued, '%s' '%s'\n", udev_device_get_seqnum(dev),
456 udev_device_get_action(dev), udev_device_get_subsystem(dev));
458 event->state = EVENT_QUEUED;
459 udev_list_node_append(&event->node, &event_list);
463 static void worker_kill(struct udev *udev, int retain)
465 struct udev_list_node *loop;
468 if (children <= retain)
471 max = children - retain;
473 udev_list_node_foreach(loop, &worker_list) {
474 struct worker *worker = node_to_worker(loop);
479 if (worker->state == WORKER_KILLED)
482 worker->state = WORKER_KILLED;
483 kill(worker->pid, SIGTERM);
487 /* lookup event for identical, parent, child device */
488 static bool is_devpath_busy(struct event *event)
490 struct udev_list_node *loop;
493 /* check if queue contains events we depend on */
494 udev_list_node_foreach(loop, &event_list) {
495 struct event *loop_event = node_to_event(loop);
497 /* we already found a later event, earlier can not block us, no need to check again */
498 if (loop_event->seqnum < event->delaying_seqnum)
501 /* event we checked earlier still exists, no need to check again */
502 if (loop_event->seqnum == event->delaying_seqnum)
505 /* found ourself, no later event can block us */
506 if (loop_event->seqnum >= event->seqnum)
509 /* check major/minor */
510 if (major(event->devnum) != 0 && event->devnum == loop_event->devnum && event->is_block == loop_event->is_block)
513 /* check network device ifindex */
514 if (event->ifindex != 0 && event->ifindex == loop_event->ifindex)
517 /* check our old name */
518 if (event->devpath_old != NULL && strcmp(loop_event->devpath, event->devpath_old) == 0) {
519 event->delaying_seqnum = loop_event->seqnum;
523 /* compare devpath */
524 common = MIN(loop_event->devpath_len, event->devpath_len);
526 /* one devpath is contained in the other? */
527 if (memcmp(loop_event->devpath, event->devpath, common) != 0)
530 /* identical device event found */
531 if (loop_event->devpath_len == event->devpath_len) {
532 /* devices names might have changed/swapped in the meantime */
533 if (major(event->devnum) != 0 && (event->devnum != loop_event->devnum || event->is_block != loop_event->is_block))
535 if (event->ifindex != 0 && event->ifindex != loop_event->ifindex)
537 event->delaying_seqnum = loop_event->seqnum;
541 /* parent device event found */
542 if (event->devpath[common] == '/') {
543 event->delaying_seqnum = loop_event->seqnum;
547 /* child device event found */
548 if (loop_event->devpath[common] == '/') {
549 event->delaying_seqnum = loop_event->seqnum;
553 /* no matching device */
560 static void event_queue_start(struct udev *udev)
562 struct udev_list_node *loop;
564 udev_list_node_foreach(loop, &event_list) {
565 struct event *event = node_to_event(loop);
567 if (event->state != EVENT_QUEUED)
570 /* do not start event if parent or child event is still running */
571 if (is_devpath_busy(event)) {
572 dbg(udev, "delay seq %llu (%s)\n", event->seqnum, event->devpath);
580 static void event_queue_cleanup(struct udev *udev, enum event_state match_type)
582 struct udev_list_node *loop, *tmp;
584 udev_list_node_foreach_safe(loop, tmp, &event_list) {
585 struct event *event = node_to_event(loop);
587 if (match_type != EVENT_UNDEF && match_type != event->state)
590 event_queue_delete(event, false);
594 static void worker_returned(int fd_worker)
597 struct worker_message msg;
599 struct udev_list_node *loop;
601 size = recv(fd_worker, &msg, sizeof(struct worker_message), MSG_DONTWAIT);
602 if (size != sizeof(struct worker_message))
605 /* lookup worker who sent the signal */
606 udev_list_node_foreach(loop, &worker_list) {
607 struct worker *worker = node_to_worker(loop);
609 if (worker->pid != msg.pid)
612 /* worker returned */
613 worker->event->exitcode = msg.exitcode;
614 event_queue_delete(worker->event, true);
615 worker->event = NULL;
616 if (worker->state != WORKER_KILLED)
617 worker->state = WORKER_IDLE;
618 worker_unref(worker);
624 /* receive the udevd message from userspace */
625 static struct udev_ctrl_connection *handle_ctrl_msg(struct udev_ctrl *uctrl)
627 struct udev *udev = udev_ctrl_get_udev(uctrl);
628 struct udev_ctrl_connection *ctrl_conn;
629 struct udev_ctrl_msg *ctrl_msg = NULL;
633 ctrl_conn = udev_ctrl_get_connection(uctrl);
634 if (ctrl_conn == NULL)
637 ctrl_msg = udev_ctrl_receive_msg(ctrl_conn);
638 if (ctrl_msg == NULL)
641 i = udev_ctrl_get_set_log_level(ctrl_msg);
643 info(udev, "udevd message (SET_LOG_PRIORITY) received, log_priority=%i\n", i);
644 udev_set_log_priority(udev, i);
645 worker_kill(udev, 0);
648 if (udev_ctrl_get_stop_exec_queue(ctrl_msg) > 0) {
649 info(udev, "udevd message (STOP_EXEC_QUEUE) received\n");
650 stop_exec_queue = true;
653 if (udev_ctrl_get_start_exec_queue(ctrl_msg) > 0) {
654 info(udev, "udevd message (START_EXEC_QUEUE) received\n");
655 stop_exec_queue = false;
658 if (udev_ctrl_get_reload(ctrl_msg) > 0) {
659 info(udev, "udevd message (RELOAD) received\n");
663 str = udev_ctrl_get_set_env(ctrl_msg);
671 val = strchr(key, '=');
675 if (val[0] == '\0') {
676 info(udev, "udevd message (ENV) received, unset '%s'\n", key);
677 udev_add_property(udev, key, NULL);
679 info(udev, "udevd message (ENV) received, set '%s=%s'\n", key, val);
680 udev_add_property(udev, key, val);
683 err(udev, "wrong key format '%s'\n", key);
687 worker_kill(udev, 0);
690 i = udev_ctrl_get_set_children_max(ctrl_msg);
692 info(udev, "udevd message (SET_MAX_CHILDREN) received, children_max=%i\n", i);
696 if (udev_ctrl_get_ping(ctrl_msg) > 0)
697 info(udev, "udevd message (SYNC) received\n");
699 if (udev_ctrl_get_exit(ctrl_msg) > 0) {
700 info(udev, "udevd message (EXIT) received\n");
702 /* keep reference to block the client until we exit */
703 udev_ctrl_connection_ref(ctrl_conn);
706 udev_ctrl_msg_unref(ctrl_msg);
707 return udev_ctrl_connection_unref(ctrl_conn);
710 /* read inotify messages */
711 static int handle_inotify(struct udev *udev)
715 struct inotify_event *ev;
717 if ((ioctl(fd_inotify, FIONREAD, &nbytes) < 0) || (nbytes <= 0))
720 buf = malloc(nbytes);
722 err(udev, "error getting buffer for inotify\n");
726 nbytes = read(fd_inotify, buf, nbytes);
728 for (pos = 0; pos < nbytes; pos += sizeof(struct inotify_event) + ev->len) {
729 struct udev_device *dev;
731 ev = (struct inotify_event *)(buf + pos);
732 dev = udev_watch_lookup(udev, ev->wd);
734 info(udev, "inotify event: %x for %s\n", ev->mask, udev_device_get_devnode(dev));
735 if (ev->mask & IN_CLOSE_WRITE) {
736 char filename[UTIL_PATH_SIZE];
739 info(udev, "device %s closed, synthesising 'change'\n", udev_device_get_devnode(dev));
740 util_strscpyl(filename, sizeof(filename), udev_device_get_syspath(dev), "/uevent", NULL);
741 fd = open(filename, O_WRONLY);
743 if (write(fd, "change", 6) < 0)
744 info(udev, "error writing uevent: %m\n");
748 if (ev->mask & IN_IGNORED)
749 udev_watch_end(udev, dev);
751 udev_device_unref(dev);
760 static void handle_signal(struct udev *udev, int signo)
771 struct udev_list_node *loop, *tmp;
773 pid = waitpid(-1, &status, WNOHANG);
777 udev_list_node_foreach_safe(loop, tmp, &worker_list) {
778 struct worker *worker = node_to_worker(loop);
780 if (worker->pid != pid)
782 info(udev, "worker [%u] exit\n", pid);
784 if (WIFEXITED(status)) {
785 if (WEXITSTATUS(status) != 0)
786 err(udev, "worker [%u] exit with return code %i\n", pid, WEXITSTATUS(status));
787 } else if (WIFSIGNALED(status)) {
788 err(udev, "worker [%u] terminated by signal %i (%s)\n",
789 pid, WTERMSIG(status), strsignal(WTERMSIG(status)));
790 } else if (WIFSTOPPED(status)) {
791 err(udev, "worker [%u] stopped\n", pid);
792 } else if (WIFCONTINUED(status)) {
793 err(udev, "worker [%u] continued\n", pid);
795 err(udev, "worker [%u] exit with status 0x%04x\n", pid, status);
798 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
799 if (worker->event != NULL) {
800 err(udev, "worker [%u] failed while handling '%s'\n",
801 pid, worker->event->devpath);
802 worker->event->exitcode = -32;
803 event_queue_delete(worker->event, true);
804 /* drop reference taken for state 'running' */
805 worker_unref(worker);
808 worker_unref(worker);
819 static void static_dev_create_from_modules(struct udev *udev)
821 struct utsname kernel;
822 char modules[UTIL_PATH_SIZE];
827 util_strscpyl(modules, sizeof(modules), "/lib/modules/", kernel.release, "/modules.devname", NULL);
828 f = fopen(modules, "r");
832 while (fgets(buf, sizeof(buf), f) != NULL) {
840 char filename[UTIL_PATH_SIZE];
846 s = strchr(modname, ' ');
852 s = strchr(devname, ' ');
858 s = strchr(devno, ' ');
860 s = strchr(devno, '\n');
863 if (sscanf(devno, "%c%u:%u", &type, &maj, &min) != 3)
866 /* set sticky bit, so we do not remove the node on module unload */
868 mode = 01600|S_IFCHR;
869 else if (type == 'b')
870 mode = 01600|S_IFBLK;
874 util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev), "/", devname, NULL);
875 util_create_path_selinux(udev, filename);
876 udev_selinux_setfscreatecon(udev, filename, mode);
877 info(udev, "mknod '%s' %c%u:%u\n", filename, type, maj, min);
878 if (mknod(filename, mode, makedev(maj, min)) < 0 && errno == EEXIST)
879 utimensat(AT_FDCWD, filename, NULL, 0);
880 udev_selinux_resetfscreatecon(udev);
886 static int copy_dev_dir(struct udev *udev, DIR *dir_from, DIR *dir_to, int maxdepth)
890 for (dent = readdir(dir_from); dent != NULL; dent = readdir(dir_from)) {
893 if (dent->d_name[0] == '.')
895 if (fstatat(dirfd(dir_from), dent->d_name, &stats, AT_SYMLINK_NOFOLLOW) != 0)
898 if (S_ISBLK(stats.st_mode) || S_ISCHR(stats.st_mode)) {
899 udev_selinux_setfscreateconat(udev, dirfd(dir_to), dent->d_name, stats.st_mode & 0777);
900 if (mknodat(dirfd(dir_to), dent->d_name, stats.st_mode, stats.st_rdev) == 0) {
901 fchmodat(dirfd(dir_to), dent->d_name, stats.st_mode & 0777, 0);
902 fchownat(dirfd(dir_to), dent->d_name, stats.st_uid, stats.st_gid, 0);
904 utimensat(dirfd(dir_to), dent->d_name, NULL, 0);
906 udev_selinux_resetfscreatecon(udev);
907 } else if (S_ISLNK(stats.st_mode)) {
908 char target[UTIL_PATH_SIZE];
911 len = readlinkat(dirfd(dir_from), dent->d_name, target, sizeof(target));
912 if (len <= 0 || len == (ssize_t)sizeof(target))
915 udev_selinux_setfscreateconat(udev, dirfd(dir_to), dent->d_name, S_IFLNK);
916 if (symlinkat(target, dirfd(dir_to), dent->d_name) < 0 && errno == EEXIST)
917 utimensat(dirfd(dir_to), dent->d_name, NULL, AT_SYMLINK_NOFOLLOW);
918 udev_selinux_resetfscreatecon(udev);
919 } else if (S_ISDIR(stats.st_mode)) {
920 DIR *dir2_from, *dir2_to;
925 udev_selinux_setfscreateconat(udev, dirfd(dir_to), dent->d_name, S_IFDIR|0755);
926 mkdirat(dirfd(dir_to), dent->d_name, 0755);
927 udev_selinux_resetfscreatecon(udev);
929 dir2_to = fdopendir(openat(dirfd(dir_to), dent->d_name, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC));
933 dir2_from = fdopendir(openat(dirfd(dir_from), dent->d_name, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC));
934 if (dir2_from == NULL) {
939 copy_dev_dir(udev, dir2_from, dir2_to, maxdepth-1);
949 static void static_dev_create_links(struct udev *udev, DIR *dir)
955 static const struct stdlinks stdlinks[] = {
956 { "core", "/proc/kcore" },
957 { "fd", "/proc/self/fd" },
958 { "stdin", "/proc/self/fd/0" },
959 { "stdout", "/proc/self/fd/1" },
960 { "stderr", "/proc/self/fd/2" },
964 for (i = 0; i < ARRAY_SIZE(stdlinks); i++) {
967 if (stat(stdlinks[i].target, &sb) == 0) {
968 udev_selinux_setfscreateconat(udev, dirfd(dir), stdlinks[i].link, S_IFLNK);
969 if (symlinkat(stdlinks[i].target, dirfd(dir), stdlinks[i].link) < 0 && errno == EEXIST)
970 utimensat(dirfd(dir), stdlinks[i].link, NULL, AT_SYMLINK_NOFOLLOW);
971 udev_selinux_resetfscreatecon(udev);
976 static void static_dev_create_from_devices(struct udev *udev, DIR *dir)
980 dir_from = opendir(LIBEXECDIR "/devices");
981 if (dir_from == NULL)
983 copy_dev_dir(udev, dir_from, dir, 8);
987 static void static_dev_create(struct udev *udev)
991 dir = opendir(udev_get_dev_path(udev));
995 static_dev_create_links(udev, dir);
996 static_dev_create_from_devices(udev, dir);
1001 static int mem_size_mb(void)
1005 long int memsize = -1;
1007 f = fopen("/proc/meminfo", "r");
1011 while (fgets(buf, sizeof(buf), f) != NULL) {
1014 if (sscanf(buf, "MemTotal: %ld kB", &value) == 1) {
1015 memsize = value / 1024;
1024 static int convert_db(struct udev *udev)
1026 char filename[UTIL_PATH_SIZE];
1028 struct udev_enumerate *udev_enumerate;
1029 struct udev_list_entry *list_entry;
1031 /* current database */
1032 util_strscpyl(filename, sizeof(filename), udev_get_run_path(udev), "/data", NULL);
1033 if (access(filename, F_OK) >= 0)
1036 /* make sure we do not get here again */
1037 util_create_path(udev, filename);
1038 mkdir(filename, 0755);
1041 util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev), "/.udev/db", NULL);
1042 if (access(filename, F_OK) < 0)
1045 f = fopen("/dev/kmsg", "w");
1047 fprintf(f, "<30>udevd[%u]: converting old udev database\n", getpid());
1051 udev_enumerate = udev_enumerate_new(udev);
1052 if (udev_enumerate == NULL)
1054 udev_enumerate_scan_devices(udev_enumerate);
1055 udev_list_entry_foreach(list_entry, udev_enumerate_get_list_entry(udev_enumerate)) {
1056 struct udev_device *device;
1058 device = udev_device_new_from_syspath(udev, udev_list_entry_get_name(list_entry));
1062 /* try to find the old database for devices without a current one */
1063 if (udev_device_read_db(device, NULL) < 0) {
1067 char devpath[UTIL_PATH_SIZE];
1068 char from[UTIL_PATH_SIZE];
1072 /* find database in old location */
1073 id = udev_device_get_id_filename(device);
1074 util_strscpyl(from, sizeof(from), udev_get_dev_path(udev), "/.udev/db/", id, NULL);
1075 if (lstat(from, &stats) == 0) {
1077 udev_device_read_db(device, from);
1083 /* find old database with $subsys:$sysname name */
1084 util_strscpyl(from, sizeof(from), udev_get_dev_path(udev),
1085 "/.udev/db/", udev_device_get_subsystem(device), ":",
1086 udev_device_get_sysname(device), NULL);
1087 if (lstat(from, &stats) == 0) {
1089 udev_device_read_db(device, from);
1095 /* find old database with the encoded devpath name */
1096 util_path_encode(udev_device_get_devpath(device), devpath, sizeof(devpath));
1097 util_strscpyl(from, sizeof(from), udev_get_dev_path(udev), "/.udev/db/", devpath, NULL);
1098 if (lstat(from, &stats) == 0) {
1100 udev_device_read_db(device, from);
1106 /* write out new database */
1108 udev_device_update_db(device);
1110 udev_device_unref(device);
1112 udev_enumerate_unref(udev_enumerate);
1116 static int systemd_fds(struct udev *udev, int *rctrl, int *rnetlink)
1118 int ctrl = -1, netlink = -1;
1121 n = sd_listen_fds(true);
1125 for (fd = SD_LISTEN_FDS_START; fd < n + SD_LISTEN_FDS_START; fd++) {
1126 if (sd_is_socket(fd, AF_LOCAL, SOCK_SEQPACKET, -1)) {
1133 if (sd_is_socket(fd, AF_NETLINK, SOCK_RAW, -1)) {
1143 if (ctrl < 0 || netlink < 0)
1146 info(udev, "ctrl=%i netlink=%i\n", ctrl, netlink);
1148 *rnetlink = netlink;
1152 static bool check_rules_timestamp(struct udev *udev)
1155 unsigned long long *stamp_usec;
1157 bool changed = false;
1159 n = udev_get_rules_path(udev, &p, &stamp_usec);
1160 for (i = 0; i < n; i++) {
1163 if (stat(p[i], &stats) < 0)
1166 if (stamp_usec[i] == ts_usec(&stats.st_mtim))
1170 if (stamp_usec[i] != 0) {
1171 info(udev, "reload - timestamp of '%s' changed\n", p[i]);
1175 /* update timestamp */
1176 stamp_usec[i] = ts_usec(&stats.st_mtim);
1182 int main(int argc, char *argv[])
1187 int daemonize = false;
1188 int resolve_names = 1;
1189 static const struct option options[] = {
1190 { "daemon", no_argument, NULL, 'd' },
1191 { "debug", no_argument, NULL, 'D' },
1192 { "children-max", required_argument, NULL, 'c' },
1193 { "exec-delay", required_argument, NULL, 'e' },
1194 { "resolve-names", required_argument, NULL, 'N' },
1195 { "help", no_argument, NULL, 'h' },
1196 { "version", no_argument, NULL, 'V' },
1200 int fd_netlink = -1;
1202 struct epoll_event ep_ctrl, ep_inotify, ep_signal, ep_netlink, ep_worker;
1203 struct udev_ctrl_connection *ctrl_conn = NULL;
1211 udev_log_init("udevd");
1212 udev_set_log_fn(udev, udev_main_log);
1213 info(udev, "version %s\n", VERSION);
1214 udev_selinux_init(udev);
1219 option = getopt_long(argc, argv, "c:deDtN:hV", options, NULL);
1228 children_max = strtoul(optarg, NULL, 0);
1231 exec_delay = strtoul(optarg, NULL, 0);
1235 if (udev_get_log_priority(udev) < LOG_INFO)
1236 udev_set_log_priority(udev, LOG_INFO);
1239 if (strcmp (optarg, "early") == 0) {
1241 } else if (strcmp (optarg, "late") == 0) {
1243 } else if (strcmp (optarg, "never") == 0) {
1246 fprintf(stderr, "resolve-names must be early, late or never\n");
1247 err(udev, "resolve-names must be early, late or never\n");
1252 printf("Usage: udevd OPTIONS\n"
1255 " --children-max=<maximum number of workers>\n"
1256 " --exec-delay=<seconds to wait before executing RUN=>\n"
1257 " --resolve-names=early|late|never\n"
1263 printf("%s\n", VERSION);
1271 * read the kernel commandline, in case we need to get into debug mode
1272 * udev.log-priority=<level> syslog priority
1273 * udev.children-max=<number of workers> events are fully serialized if set to 1
1276 f = fopen("/proc/cmdline", "r");
1280 if (fgets(cmdline, sizeof(cmdline), f) != NULL) {
1283 pos = strstr(cmdline, "udev.log-priority=");
1285 pos += strlen("udev.log-priority=");
1286 udev_set_log_priority(udev, util_log_priority(pos));
1289 pos = strstr(cmdline, "udev.children-max=");
1291 pos += strlen("udev.children-max=");
1292 children_max = strtoul(pos, NULL, 0);
1295 pos = strstr(cmdline, "udev.exec-delay=");
1297 pos += strlen("udev.exec-delay=");
1298 exec_delay = strtoul(pos, NULL, 0);
1304 if (getuid() != 0) {
1305 fprintf(stderr, "root privileges required\n");
1306 err(udev, "root privileges required\n");
1310 /* set umask before creating any file/directory */
1315 mkdir(udev_get_run_path(udev), 0755);
1317 /* create standard links, copy static nodes, create nodes from modules */
1318 static_dev_create(udev);
1319 static_dev_create_from_modules(udev);
1321 /* before opening new files, make sure std{in,out,err} fds are in a sane state */
1325 fd = open("/dev/null", O_RDWR);
1327 if (write(STDOUT_FILENO, 0, 0) < 0)
1328 dup2(fd, STDOUT_FILENO);
1329 if (write(STDERR_FILENO, 0, 0) < 0)
1330 dup2(fd, STDERR_FILENO);
1331 if (fd > STDERR_FILENO)
1334 fprintf(stderr, "cannot open /dev/null\n");
1335 err(udev, "cannot open /dev/null\n");
1339 if (systemd_fds(udev, &fd_ctrl, &fd_netlink) >= 0) {
1340 /* get control and netlink socket from from systemd */
1341 udev_ctrl = udev_ctrl_new_from_fd(udev, fd_ctrl);
1342 if (udev_ctrl == NULL) {
1343 err(udev, "error taking over udev control socket");
1348 monitor = udev_monitor_new_from_netlink_fd(udev, "kernel", fd_netlink);
1349 if (monitor == NULL) {
1350 err(udev, "error taking over netlink socket\n");
1355 /* open control and netlink socket */
1356 udev_ctrl = udev_ctrl_new(udev);
1357 if (udev_ctrl == NULL) {
1358 fprintf(stderr, "error initializing udev control socket");
1359 err(udev, "error initializing udev control socket");
1363 fd_ctrl = udev_ctrl_get_fd(udev_ctrl);
1365 monitor = udev_monitor_new_from_netlink(udev, "kernel");
1366 if (monitor == NULL) {
1367 fprintf(stderr, "error initializing netlink socket\n");
1368 err(udev, "error initializing netlink socket\n");
1372 fd_netlink = udev_monitor_get_fd(monitor);
1375 if (udev_monitor_enable_receiving(monitor) < 0) {
1376 fprintf(stderr, "error binding netlink socket\n");
1377 err(udev, "error binding netlink socket\n");
1382 if (udev_ctrl_enable_receiving(udev_ctrl) < 0) {
1383 fprintf(stderr, "error binding udev control socket\n");
1384 err(udev, "error binding udev control socket\n");
1389 udev_monitor_set_receive_buffer_size(monitor, 128*1024*1024);
1391 /* create queue file before signalling 'ready', to make sure we block 'settle' */
1392 udev_queue_export = udev_queue_export_new(udev);
1393 if (udev_queue_export == NULL) {
1394 err(udev, "error creating queue file\n");
1407 err(udev, "fork of daemon failed: %m\n");
1412 goto exit_daemonize;
1417 fd = open("/proc/self/oom_score_adj", O_RDWR);
1419 /* Fallback to old interface */
1420 fd = open("/proc/self/oom_adj", O_RDWR);
1422 err(udev, "error disabling OOM: %m\n");
1424 /* OOM_DISABLE == -17 */
1425 write(fd, "-17", 3);
1429 write(fd, "-1000", 5);
1433 sd_notify(1, "READY=1");
1436 f = fopen("/dev/kmsg", "w");
1438 fprintf(f, "<30>udevd[%u]: starting version " VERSION "\n", getpid());
1445 fd = open("/dev/null", O_RDWR);
1447 dup2(fd, STDIN_FILENO);
1448 dup2(fd, STDOUT_FILENO);
1449 dup2(fd, STDERR_FILENO);
1454 fd_inotify = udev_watch_init(udev);
1455 if (fd_inotify < 0) {
1456 fprintf(stderr, "error initializing inotify\n");
1457 err(udev, "error initializing inotify\n");
1461 udev_watch_restore(udev);
1463 /* block and listen to all signals on signalfd */
1465 sigprocmask(SIG_SETMASK, &mask, &sigmask_orig);
1466 fd_signal = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC);
1467 if (fd_signal < 0) {
1468 fprintf(stderr, "error creating signalfd\n");
1469 err(udev, "error creating signalfd\n");
1474 /* unnamed socket from workers to the main daemon */
1475 if (socketpair(AF_LOCAL, SOCK_DGRAM|SOCK_CLOEXEC, 0, worker_watch) < 0) {
1476 fprintf(stderr, "error creating socketpair\n");
1477 err(udev, "error creating socketpair\n");
1481 fd_worker = worker_watch[READ_END];
1483 udev_builtin_init(udev);
1485 rules = udev_rules_new(udev, resolve_names);
1486 if (rules == NULL) {
1487 err(udev, "error reading rules\n");
1491 memset(&ep_ctrl, 0, sizeof(struct epoll_event));
1492 ep_ctrl.events = EPOLLIN;
1493 ep_ctrl.data.fd = fd_ctrl;
1495 memset(&ep_inotify, 0, sizeof(struct epoll_event));
1496 ep_inotify.events = EPOLLIN;
1497 ep_inotify.data.fd = fd_inotify;
1499 memset(&ep_signal, 0, sizeof(struct epoll_event));
1500 ep_signal.events = EPOLLIN;
1501 ep_signal.data.fd = fd_signal;
1503 memset(&ep_netlink, 0, sizeof(struct epoll_event));
1504 ep_netlink.events = EPOLLIN;
1505 ep_netlink.data.fd = fd_netlink;
1507 memset(&ep_worker, 0, sizeof(struct epoll_event));
1508 ep_worker.events = EPOLLIN;
1509 ep_worker.data.fd = fd_worker;
1511 fd_ep = epoll_create1(EPOLL_CLOEXEC);
1513 err(udev, "error creating epoll fd: %m\n");
1516 if (epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_ctrl, &ep_ctrl) < 0 ||
1517 epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_inotify, &ep_inotify) < 0 ||
1518 epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_signal, &ep_signal) < 0 ||
1519 epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_netlink, &ep_netlink) < 0 ||
1520 epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_worker, &ep_worker) < 0) {
1521 err(udev, "fail to add fds to epoll: %m\n");
1525 /* if needed, convert old database from earlier udev version */
1528 if (children_max <= 0) {
1529 int memsize = mem_size_mb();
1531 /* set value depending on the amount of RAM */
1533 children_max = 128 + (memsize / 8);
1537 info(udev, "set children_max to %u\n", children_max);
1539 udev_rules_apply_static_dev_perms(rules);
1541 udev_list_node_init(&event_list);
1542 udev_list_node_init(&worker_list);
1545 static unsigned long long last_usec;
1546 struct epoll_event ev[8];
1549 bool is_worker, is_signal, is_inotify, is_netlink, is_ctrl;
1553 /* close sources of new events and discard buffered events */
1555 epoll_ctl(fd_ep, EPOLL_CTL_DEL, fd_ctrl, NULL);
1558 if (monitor != NULL) {
1559 epoll_ctl(fd_ep, EPOLL_CTL_DEL, fd_netlink, NULL);
1560 udev_monitor_unref(monitor);
1563 if (fd_inotify >= 0) {
1564 epoll_ctl(fd_ep, EPOLL_CTL_DEL, fd_inotify, NULL);
1569 /* discard queued events and kill workers */
1570 event_queue_cleanup(udev, EVENT_QUEUED);
1571 worker_kill(udev, 0);
1573 /* exit after all has cleaned up */
1574 if (udev_list_node_is_empty(&event_list) && udev_list_node_is_empty(&worker_list))
1577 /* timeout at exit for workers to finish */
1578 timeout = 60 * 1000;
1579 } else if (udev_list_node_is_empty(&event_list) && children > 2) {
1580 /* set timeout to kill idle workers */
1585 fdcount = epoll_wait(fd_ep, ev, ARRAY_SIZE(ev), timeout);
1591 info(udev, "timeout, giving up waiting for workers to finish\n");
1595 /* timeout - kill idle workers */
1596 worker_kill(udev, 2);
1599 is_worker = is_signal = is_inotify = is_netlink = is_ctrl = false;
1600 for (i = 0; i < fdcount; i++) {
1601 if (ev[i].data.fd == fd_worker && ev[i].events & EPOLLIN)
1603 else if (ev[i].data.fd == fd_netlink && ev[i].events & EPOLLIN)
1605 else if (ev[i].data.fd == fd_signal && ev[i].events & EPOLLIN)
1607 else if (ev[i].data.fd == fd_inotify && ev[i].events & EPOLLIN)
1609 else if (ev[i].data.fd == fd_ctrl && ev[i].events & EPOLLIN)
1613 /* check for changed config, every 3 seconds at most */
1614 if ((now_usec() - last_usec) > 3 * 1000 * 1000) {
1615 if (check_rules_timestamp(udev))
1617 if (udev_builtin_validate(udev))
1620 last_usec = now_usec();
1623 /* reload requested, HUP signal received, rules changed, builtin changed */
1625 worker_kill(udev, 0);
1626 rules = udev_rules_unref(rules);
1627 udev_builtin_exit(udev);
1631 /* event has finished */
1633 worker_returned(fd_worker);
1636 struct udev_device *dev;
1638 dev = udev_monitor_receive_device(monitor);
1640 udev_device_set_usec_initialized(dev, now_usec());
1641 if (event_queue_insert(dev) < 0)
1642 udev_device_unref(dev);
1646 /* start new events */
1647 if (!udev_list_node_is_empty(&event_list) && !udev_exit && !stop_exec_queue) {
1649 rules = udev_rules_new(udev, resolve_names);
1651 event_queue_start(udev);
1655 struct signalfd_siginfo fdsi;
1658 size = read(fd_signal, &fdsi, sizeof(struct signalfd_siginfo));
1659 if (size == sizeof(struct signalfd_siginfo))
1660 handle_signal(udev, fdsi.ssi_signo);
1663 /* we are shutting down, the events below are not handled anymore */
1667 /* device node watch */
1669 handle_inotify(udev);
1672 * This needs to be after the inotify handling, to make sure,
1673 * that the ping is send back after the possibly generated
1674 * "change" events by the inotify device node watch.
1676 * A single time we may receive a client connection which we need to
1677 * keep open to block the client. It will be closed right before we
1681 ctrl_conn = handle_ctrl_msg(udev_ctrl);
1686 udev_queue_export_cleanup(udev_queue_export);
1687 udev_ctrl_cleanup(udev_ctrl);
1691 worker_list_cleanup(udev);
1692 event_queue_cleanup(udev, EVENT_UNDEF);
1693 udev_rules_unref(rules);
1694 udev_builtin_exit(udev);
1697 if (worker_watch[READ_END] >= 0)
1698 close(worker_watch[READ_END]);
1699 if (worker_watch[WRITE_END] >= 0)
1700 close(worker_watch[WRITE_END]);
1701 udev_monitor_unref(monitor);
1702 udev_queue_export_unref(udev_queue_export);
1703 udev_ctrl_connection_unref(ctrl_conn);
1704 udev_ctrl_unref(udev_ctrl);
1705 udev_selinux_exit(udev);