2 * Copyright (C) 2004-2009 Kay Sievers <kay.sievers@vrfy.org>
3 * Copyright (C) 2004 Chris Friesen <chris_friesen@sympatico.ca>
4 * Copyright (C) 2009 Canonical Ltd.
5 * Copyright (C) 2009 Scott James Remnant <scott@netsplit.com>
7 * This program is free software: you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation, either version 2 of the License, or
10 * (at your option) any later version.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with this program. If not, see <http://www.gnu.org/licenses/>.
35 #include <sys/prctl.h>
36 #include <sys/socket.h>
38 #include <sys/signalfd.h>
39 #include <sys/select.h>
43 #include <sys/ioctl.h>
44 #include <sys/inotify.h>
45 #include <sys/utsname.h>
49 #define UDEVD_PRIORITY -4
50 #define UDEV_PRIORITY -2
54 static void log_fn(struct udev *udev, int priority,
55 const char *file, int line, const char *fn,
56 const char *format, va_list args)
63 vsnprintf(buf, sizeof(buf), format, args);
64 gettimeofday(&tv, &tz);
65 fprintf(stderr, "%llu.%06u [%u] %s: %s",
66 (unsigned long long) tv.tv_sec, (unsigned int) tv.tv_usec,
67 (int) getpid(), fn, buf);
69 vsyslog(priority, format, args);
73 static struct udev_rules *rules;
74 static struct udev_queue_export *udev_queue_export;
75 static struct udev_ctrl *udev_ctrl;
76 static struct udev_monitor *monitor;
77 static int worker_watch[2];
78 static pid_t settle_pid;
79 static bool stop_exec_queue;
80 static bool reload_config;
82 static int children_max;
83 static int exec_delay;
84 static sigset_t orig_sigmask;
85 static struct udev_list_node event_list;
86 static struct udev_list_node worker_list;
87 static bool udev_exit;
88 static volatile sig_atomic_t worker_exit;
98 static struct pollfd pfd[] = {
99 [FD_NETLINK] = { .events = POLLIN },
100 [FD_WORKER] = { .events = POLLIN },
101 [FD_SIGNAL] = { .events = POLLIN },
102 [FD_INOTIFY] = { .events = POLLIN },
103 [FD_CONTROL] = { .events = POLLIN },
113 struct udev_list_node node;
115 struct udev_device *dev;
116 enum event_state state;
118 unsigned long long int delaying_seqnum;
119 unsigned long long int seqnum;
122 const char *devpath_old;
127 static struct event *node_to_event(struct udev_list_node *node)
131 event = (char *)node;
132 event -= offsetof(struct event, node);
133 return (struct event *)event;
144 struct udev_list_node node;
148 struct udev_monitor *monitor;
149 enum worker_state state;
153 /* passed from worker to main process */
154 struct worker_message {
159 static struct worker *node_to_worker(struct udev_list_node *node)
163 worker = (char *)node;
164 worker -= offsetof(struct worker, node);
165 return (struct worker *)worker;
168 static void event_queue_delete(struct event *event)
170 udev_list_node_remove(&event->node);
172 /* mark as failed, if "add" event returns non-zero */
173 if (event->exitcode != 0 && strcmp(udev_device_get_action(event->dev), "remove") != 0)
174 udev_queue_export_device_failed(udev_queue_export, event->dev);
176 udev_queue_export_device_finished(udev_queue_export, event->dev);
178 info(event->udev, "seq %llu done with %i\n", udev_device_get_seqnum(event->dev), event->exitcode);
179 udev_device_unref(event->dev);
183 static void event_sig_handler(int signum)
195 static struct worker *worker_ref(struct worker *worker)
201 static void worker_unref(struct worker *worker)
204 if (worker->refcount > 0)
207 udev_list_node_remove(&worker->node);
208 udev_monitor_unref(worker->monitor);
210 info(worker->udev, "worker [%u] cleaned up\n", worker->pid);
214 static void worker_new(struct event *event)
216 struct worker *worker;
217 struct udev_monitor *worker_monitor;
219 struct sigaction act;
221 /* listen for new events */
222 worker_monitor = udev_monitor_new_from_netlink(event->udev, NULL);
223 if (worker_monitor == NULL)
225 /* allow the main daemon netlink address to send devices to the worker */
226 udev_monitor_allow_unicast_sender(worker_monitor, monitor);
227 udev_monitor_enable_receiving(worker_monitor);
229 worker = calloc(1, sizeof(struct worker));
230 if (worker == NULL) {
231 udev_monitor_unref(worker_monitor);
234 /* worker + event reference */
235 worker->refcount = 2;
236 worker->udev = event->udev;
242 struct udev_device *dev;
243 struct pollfd pmon = {
244 .fd = udev_monitor_get_fd(worker_monitor),
248 udev_queue_export_unref(udev_queue_export);
249 udev_monitor_unref(monitor);
250 udev_ctrl_unref(udev_ctrl);
251 close(pfd[FD_SIGNAL].fd);
252 close(worker_watch[READ_END]);
254 udev_log_init("udevd-work");
255 setpriority(PRIO_PROCESS, 0, UDEV_PRIORITY);
257 /* set signal handlers */
258 memset(&act, 0x00, sizeof(act));
259 act.sa_handler = event_sig_handler;
260 sigemptyset (&act.sa_mask);
262 sigaction(SIGTERM, &act, NULL);
263 sigaction(SIGALRM, &act, NULL);
265 /* unblock SIGALRM */
266 sigfillset(&sigmask);
267 sigdelset(&sigmask, SIGALRM);
268 sigprocmask(SIG_SETMASK, &sigmask, NULL);
269 /* SIGTERM is unblocked in ppoll() */
270 sigdelset(&sigmask, SIGTERM);
272 /* request TERM signal if parent exits */
273 prctl(PR_SET_PDEATHSIG, SIGTERM);
279 struct udev_event *udev_event;
280 struct worker_message msg = {};
284 info(event->udev, "seq %llu running\n", udev_device_get_seqnum(dev));
285 udev_event = udev_event_new(dev);
286 if (udev_event == NULL)
289 /* set timeout to prevent hanging processes */
290 alarm(UDEV_EVENT_TIMEOUT);
293 udev_event->exec_delay = exec_delay;
295 /* apply rules, create node, symlinks */
296 err = udev_event_execute_rules(udev_event, rules);
298 /* rules may change/disable the timeout */
299 if (udev_device_get_event_timeout(dev) >= 0)
300 alarm(udev_device_get_event_timeout(dev));
303 failed = udev_event_execute_run(udev_event, &orig_sigmask);
307 /* apply/restore inotify watch */
308 if (err == 0 && udev_event->inotify_watch) {
309 udev_watch_begin(udev_event->udev, dev);
310 udev_device_update_db(dev);
313 /* send processed event back to libudev listeners */
314 udev_monitor_send_device(worker_monitor, NULL, dev);
316 /* send udevd the result of the event execution */
319 else if (failed != 0)
320 msg.exitcode = failed;
322 send(worker_watch[WRITE_END], &msg, sizeof(struct worker_message), 0);
324 info(event->udev, "seq %llu processed with %i\n", udev_device_get_seqnum(dev), err);
325 udev_event_unref(udev_event);
326 udev_device_unref(dev);
329 /* wait for more device messages or signal from udevd */
330 while (!worker_exit) {
333 fdcount = ppoll(&pmon, 1, NULL, &sigmask);
337 if (pmon.revents & POLLIN) {
338 dev = udev_monitor_receive_device(worker_monitor);
343 } while (dev != NULL);
345 udev_monitor_unref(worker_monitor);
350 udev_monitor_unref(worker_monitor);
351 event->state = EVENT_QUEUED;
353 err(event->udev, "fork of child failed: %m\n");
356 /* close monitor, but keep address around */
357 udev_monitor_disconnect(worker_monitor);
358 worker->monitor = worker_monitor;
360 worker->state = WORKER_RUNNING;
361 worker->event = event;
362 event->state = EVENT_RUNNING;
363 udev_list_node_append(&worker->node, &worker_list);
365 info(event->udev, "seq %llu forked new worker [%u]\n", udev_device_get_seqnum(event->dev), pid);
370 static void event_run(struct event *event, bool force)
372 struct udev_list_node *loop;
374 udev_list_node_foreach(loop, &worker_list) {
375 struct worker *worker = node_to_worker(loop);
378 if (worker->state != WORKER_IDLE)
381 count = udev_monitor_send_device(monitor, worker->monitor, event->dev);
383 err(event->udev, "worker [%u] did not accept message %zi (%m), kill it\n", worker->pid, count);
384 kill(worker->pid, SIGKILL);
385 worker->state = WORKER_KILLED;
389 worker->event = event;
390 worker->state = WORKER_RUNNING;
391 event->state = EVENT_RUNNING;
395 if (!force && children >= children_max) {
396 if (children_max > 1)
397 info(event->udev, "maximum number (%i) of children reached\n", children);
401 /* start new worker and pass initial device */
405 static int event_queue_insert(struct udev_device *dev)
409 event = calloc(1, sizeof(struct event));
413 event->udev = udev_device_get_udev(dev);
415 event->seqnum = udev_device_get_seqnum(dev);
416 event->devpath = udev_device_get_devpath(dev);
417 event->devpath_len = strlen(event->devpath);
418 event->devpath_old = udev_device_get_devpath_old(dev);
419 event->devnum = udev_device_get_devnum(dev);
420 event->is_block = (strcmp("block", udev_device_get_subsystem(dev)) == 0);
422 udev_queue_export_device_queued(udev_queue_export, dev);
423 info(event->udev, "seq %llu queued, '%s' '%s'\n", udev_device_get_seqnum(dev),
424 udev_device_get_action(dev), udev_device_get_subsystem(dev));
426 event->state = EVENT_QUEUED;
427 udev_list_node_append(&event->node, &event_list);
429 /* run all events with a timeout set immediately */
430 if (udev_device_get_timeout(dev) > 0) {
431 event_run(event, true);
438 static void worker_kill(struct udev *udev, int retain)
440 struct udev_list_node *loop;
443 if (children <= retain)
446 max = children - retain;
448 udev_list_node_foreach(loop, &worker_list) {
449 struct worker *worker = node_to_worker(loop);
454 if (worker->state == WORKER_KILLED)
457 worker->state = WORKER_KILLED;
458 kill(worker->pid, SIGTERM);
462 /* lookup event for identical, parent, child device */
463 static bool is_devpath_busy(struct event *event)
465 struct udev_list_node *loop;
468 /* check if queue contains events we depend on */
469 udev_list_node_foreach(loop, &event_list) {
470 struct event *loop_event = node_to_event(loop);
472 /* we already found a later event, earlier can not block us, no need to check again */
473 if (loop_event->seqnum < event->delaying_seqnum)
476 /* event we checked earlier still exists, no need to check again */
477 if (loop_event->seqnum == event->delaying_seqnum)
480 /* found ourself, no later event can block us */
481 if (loop_event->seqnum >= event->seqnum)
484 /* check major/minor */
485 if (major(event->devnum) != 0 && event->devnum == loop_event->devnum && event->is_block == loop_event->is_block)
488 /* check our old name */
489 if (event->devpath_old != NULL && strcmp(loop_event->devpath, event->devpath_old) == 0) {
490 event->delaying_seqnum = loop_event->seqnum;
494 /* compare devpath */
495 common = MIN(loop_event->devpath_len, event->devpath_len);
497 /* one devpath is contained in the other? */
498 if (memcmp(loop_event->devpath, event->devpath, common) != 0)
501 /* identical device event found */
502 if (loop_event->devpath_len == event->devpath_len) {
503 event->delaying_seqnum = loop_event->seqnum;
507 /* parent device event found */
508 if (event->devpath[common] == '/') {
509 event->delaying_seqnum = loop_event->seqnum;
513 /* child device event found */
514 if (loop_event->devpath[common] == '/') {
515 event->delaying_seqnum = loop_event->seqnum;
519 /* no matching device */
526 static void events_start(struct udev *udev)
528 struct udev_list_node *loop;
530 udev_list_node_foreach(loop, &event_list) {
531 struct event *event = node_to_event(loop);
533 if (event->state != EVENT_QUEUED)
536 /* do not start event if parent or child event is still running */
537 if (is_devpath_busy(event)) {
538 dbg(udev, "delay seq %llu (%s)\n", event->seqnum, event->devpath);
542 event_run(event, false);
546 static void worker_returned(void)
549 struct worker_message msg;
551 struct udev_list_node *loop;
553 size = recv(pfd[FD_WORKER].fd, &msg, sizeof(struct worker_message), MSG_DONTWAIT);
554 if (size != sizeof(struct worker_message))
557 /* lookup worker who sent the signal */
558 udev_list_node_foreach(loop, &worker_list) {
559 struct worker *worker = node_to_worker(loop);
561 if (worker->pid != msg.pid)
564 /* worker returned */
565 worker->event->exitcode = msg.exitcode;
566 event_queue_delete(worker->event);
567 worker->event = NULL;
568 if (worker->state != WORKER_KILLED)
569 worker->state = WORKER_IDLE;
570 worker_unref(worker);
576 /* receive the udevd message from userspace */
577 static void handle_ctrl_msg(struct udev_ctrl *uctrl)
579 struct udev *udev = udev_ctrl_get_udev(uctrl);
580 struct udev_ctrl_msg *ctrl_msg;
584 ctrl_msg = udev_ctrl_receive_msg(uctrl);
585 if (ctrl_msg == NULL)
588 i = udev_ctrl_get_set_log_level(ctrl_msg);
590 info(udev, "udevd message (SET_LOG_PRIORITY) received, log_priority=%i\n", i);
591 udev_set_log_priority(udev, i);
592 worker_kill(udev, 0);
595 if (udev_ctrl_get_stop_exec_queue(ctrl_msg) > 0) {
596 info(udev, "udevd message (STOP_EXEC_QUEUE) received\n");
597 stop_exec_queue = true;
600 if (udev_ctrl_get_start_exec_queue(ctrl_msg) > 0) {
601 info(udev, "udevd message (START_EXEC_QUEUE) received\n");
602 stop_exec_queue = false;
605 if (udev_ctrl_get_reload_rules(ctrl_msg) > 0) {
606 info(udev, "udevd message (RELOAD_RULES) received\n");
607 reload_config = true;
610 str = udev_ctrl_get_set_env(ctrl_msg);
618 val = strchr(key, '=');
622 if (val[0] == '\0') {
623 info(udev, "udevd message (ENV) received, unset '%s'\n", key);
624 udev_add_property(udev, key, NULL);
626 info(udev, "udevd message (ENV) received, set '%s=%s'\n", key, val);
627 udev_add_property(udev, key, val);
630 err(udev, "wrong key format '%s'\n", key);
634 worker_kill(udev, 0);
637 i = udev_ctrl_get_set_children_max(ctrl_msg);
639 info(udev, "udevd message (SET_MAX_CHILDREN) received, children_max=%i\n", i);
643 settle_pid = udev_ctrl_get_settle(ctrl_msg);
644 if (settle_pid > 0) {
645 info(udev, "udevd message (SETTLE) received\n");
646 kill(settle_pid, SIGUSR1);
649 udev_ctrl_msg_unref(ctrl_msg);
652 /* read inotify messages */
653 static int handle_inotify(struct udev *udev)
657 struct inotify_event *ev;
659 if ((ioctl(pfd[FD_INOTIFY].fd, FIONREAD, &nbytes) < 0) || (nbytes <= 0))
662 buf = malloc(nbytes);
664 err(udev, "error getting buffer for inotify\n");
668 nbytes = read(pfd[FD_INOTIFY].fd, buf, nbytes);
670 for (pos = 0; pos < nbytes; pos += sizeof(struct inotify_event) + ev->len) {
671 struct udev_device *dev;
673 ev = (struct inotify_event *)(buf + pos);
677 info(udev, "inotify event: %x for %s\n", ev->mask, ev->name);
678 s = strstr(ev->name, ".rules");
681 if (strlen(s) != strlen(".rules"))
683 reload_config = true;
687 dev = udev_watch_lookup(udev, ev->wd);
689 info(udev, "inotify event: %x for %s\n", ev->mask, udev_device_get_devnode(dev));
690 if (ev->mask & IN_CLOSE_WRITE) {
691 char filename[UTIL_PATH_SIZE];
694 info(udev, "device %s closed, synthesising 'change'\n", udev_device_get_devnode(dev));
695 util_strscpyl(filename, sizeof(filename), udev_device_get_syspath(dev), "/uevent", NULL);
696 fd = open(filename, O_WRONLY);
697 if (fd < 0 || write(fd, "change", 6) < 0)
698 info(udev, "error writing uevent: %m\n");
701 if (ev->mask & IN_IGNORED)
702 udev_watch_end(udev, dev);
704 udev_device_unref(dev);
713 static void handle_signal(struct udev *udev, int signo)
724 struct udev_list_node *loop, *tmp;
726 pid = waitpid(-1, &status, WNOHANG);
730 udev_list_node_foreach_safe(loop, tmp, &worker_list) {
731 struct worker *worker = node_to_worker(loop);
733 if (worker->pid != pid)
736 info(udev, "worker [%u] exit\n", pid);
737 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
738 err(udev, "worker [%u] unexpectedly returned with status 0x%04x\n", pid, status);
739 if (worker->event != NULL) {
740 err(udev, "worker [%u] failed while handling '%s'\n", pid, worker->event->devpath);
741 worker->event->exitcode = -32;
742 event_queue_delete(worker->event);
743 /* drop reference from running event */
744 worker_unref(worker);
747 worker_unref(worker);
753 reload_config = true;
758 static void static_dev_create_from_modules(struct udev *udev)
760 struct utsname kernel;
761 char modules[UTIL_PATH_SIZE];
766 util_strscpyl(modules, sizeof(modules), "/lib/modules/", kernel.release, "/modules.devname", NULL);
767 f = fopen(modules, "r");
771 while (fgets(buf, sizeof(buf), f) != NULL) {
779 char filename[UTIL_PATH_SIZE];
785 s = strchr(modname, ' ');
791 s = strchr(devname, ' ');
797 s = strchr(devno, ' ');
799 s = strchr(devno, '\n');
802 if (sscanf(devno, "%c%u:%u", &type, &maj, &min) != 3)
806 mode = 0600 | S_IFCHR;
807 else if (type == 'b')
808 mode = 0600 | S_IFBLK;
812 util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev), "/", devname, NULL);
813 util_create_path(udev, filename);
814 udev_selinux_setfscreatecon(udev, filename, mode);
815 info(udev, "mknod '%s' %c%u:%u\n", filename, type, maj, min);
816 if (mknod(filename, mode, makedev(maj, min)) < 0 && errno == EEXIST)
817 utimensat(AT_FDCWD, filename, NULL, 0);
818 udev_selinux_resetfscreatecon(udev);
824 static int copy_dir(struct udev *udev, DIR *dir_from, DIR *dir_to, int maxdepth)
828 for (dent = readdir(dir_from); dent != NULL; dent = readdir(dir_from)) {
831 if (dent->d_name[0] == '.')
833 if (fstatat(dirfd(dir_from), dent->d_name, &stats, AT_SYMLINK_NOFOLLOW) != 0)
836 if (S_ISBLK(stats.st_mode) || S_ISCHR(stats.st_mode)) {
837 udev_selinux_setfscreateconat(udev, dirfd(dir_to), dent->d_name, stats.st_mode & 0777);
838 if (mknodat(dirfd(dir_to), dent->d_name, stats.st_mode, stats.st_rdev) == 0) {
839 fchmodat(dirfd(dir_to), dent->d_name, stats.st_mode & 0777, 0);
840 fchownat(dirfd(dir_to), dent->d_name, stats.st_uid, stats.st_gid, 0);
842 utimensat(dirfd(dir_to), dent->d_name, NULL, 0);
844 udev_selinux_resetfscreatecon(udev);
845 } else if (S_ISLNK(stats.st_mode)) {
846 char target[UTIL_PATH_SIZE];
849 len = readlinkat(dirfd(dir_from), dent->d_name, target, sizeof(target));
850 if (len <= 0 || len == (ssize_t)sizeof(target))
853 udev_selinux_setfscreateconat(udev, dirfd(dir_to), dent->d_name, S_IFLNK);
854 if (symlinkat(target, dirfd(dir_to), dent->d_name) < 0 && errno == EEXIST)
855 utimensat(dirfd(dir_to), dent->d_name, NULL, AT_SYMLINK_NOFOLLOW);
856 udev_selinux_resetfscreatecon(udev);
857 } else if (S_ISDIR(stats.st_mode)) {
858 DIR *dir2_from, *dir2_to;
863 udev_selinux_setfscreateconat(udev, dirfd(dir_to), dent->d_name, S_IFDIR|0755);
864 mkdirat(dirfd(dir_to), dent->d_name, 0755);
865 udev_selinux_resetfscreatecon(udev);
867 dir2_to = fdopendir(openat(dirfd(dir_to), dent->d_name, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC));
871 dir2_from = fdopendir(openat(dirfd(dir_from), dent->d_name, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC));
872 if (dir2_from == NULL) {
877 copy_dir(udev, dir2_from, dir2_to, maxdepth-1);
887 static void static_dev_create_links(struct udev *udev, DIR *dir)
893 static const struct stdlinks stdlinks[] = {
894 { "core", "/proc/kcore" },
895 { "fd", "/proc/self/fd" },
896 { "stdin", "/proc/self/fd/0" },
897 { "stdout", "/proc/self/fd/1" },
898 { "stderr", "/proc/self/fd/2" },
902 for (i = 0; i < ARRAY_SIZE(stdlinks); i++) {
903 udev_selinux_setfscreateconat(udev, dirfd(dir), stdlinks[i].link, S_IFLNK);
904 if (symlinkat(stdlinks[i].target, dirfd(dir), stdlinks[i].link) < 0 && errno == EEXIST)
905 utimensat(dirfd(dir), stdlinks[i].link, NULL, AT_SYMLINK_NOFOLLOW);
906 udev_selinux_resetfscreatecon(udev);
910 static void static_dev_create_from_devices(struct udev *udev, DIR *dir)
914 dir_from = opendir(LIBEXECDIR "/devices");
915 if (dir_from == NULL)
917 copy_dir(udev, dir_from, dir, 8);
921 static void static_dev_create(struct udev *udev)
925 dir = opendir(udev_get_dev_path(udev));
929 static_dev_create_links(udev, dir);
930 static_dev_create_from_devices(udev, dir);
935 static int mem_size_mb(void)
939 long int memsize = -1;
941 f = fopen("/proc/meminfo", "r");
945 while (fgets(buf, sizeof(buf), f) != NULL) {
948 if (sscanf(buf, "MemTotal: %ld kB", &value) == 1) {
949 memsize = value / 1024;
958 static int init_notify(const char *state)
961 struct msghdr msghdr;
966 struct sockaddr_un un;
969 struct cmsghdr cmsghdr;
970 uint8_t buf[CMSG_SPACE(sizeof(struct ucred))];
974 if (!(e = getenv("NOTIFY_SOCKET"))) {
979 /* Must be an abstract socket, or an absolute path */
980 if ((e[0] != '@' && e[0] != '/') || e[1] == 0) {
985 if ((fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0)) < 0) {
990 memset(&sockaddr, 0, sizeof(sockaddr));
991 sockaddr.sa.sa_family = AF_UNIX;
992 strncpy(sockaddr.un.sun_path, e, sizeof(sockaddr.un.sun_path));
994 if (sockaddr.un.sun_path[0] == '@')
995 sockaddr.un.sun_path[0] = 0;
997 memset(&iovec, 0, sizeof(iovec));
998 iovec.iov_base = (char*) state;
999 iovec.iov_len = strlen(state);
1001 memset(&control, 0, sizeof(control));
1002 control.cmsghdr.cmsg_level = SOL_SOCKET;
1003 control.cmsghdr.cmsg_type = SCM_CREDENTIALS;
1004 control.cmsghdr.cmsg_len = CMSG_LEN(sizeof(struct ucred));
1006 ucred = (struct ucred*) CMSG_DATA(&control.cmsghdr);
1007 ucred->pid = getpid();
1008 ucred->uid = getuid();
1009 ucred->gid = getgid();
1011 memset(&msghdr, 0, sizeof(msghdr));
1012 msghdr.msg_name = &sockaddr;
1013 msghdr.msg_namelen = sizeof(sa_family_t) + strlen(e);
1014 if (msghdr.msg_namelen > sizeof(struct sockaddr_un))
1015 msghdr.msg_namelen = sizeof(struct sockaddr_un);
1016 msghdr.msg_iov = &iovec;
1017 msghdr.msg_iovlen = 1;
1018 msghdr.msg_control = &control;
1019 msghdr.msg_controllen = control.cmsghdr.cmsg_len;
1021 if (sendmsg(fd, &msghdr, MSG_NOSIGNAL) < 0) {
1035 int main(int argc, char *argv[])
1041 int daemonize = false;
1042 int resolve_names = 1;
1043 static const struct option options[] = {
1044 { "daemon", no_argument, NULL, 'd' },
1045 { "debug", no_argument, NULL, 'D' },
1046 { "children-max", required_argument, NULL, 'c' },
1047 { "exec-delay", required_argument, NULL, 'e' },
1048 { "resolve-names", required_argument, NULL, 'N' },
1049 { "help", no_argument, NULL, 'h' },
1050 { "version", no_argument, NULL, 'V' },
1059 udev_log_init("udevd");
1060 udev_set_log_fn(udev, log_fn);
1061 info(udev, "version %s\n", VERSION);
1062 udev_selinux_init(udev);
1067 option = getopt_long(argc, argv, "c:deDthV", options, NULL);
1076 children_max = strtoul(optarg, NULL, 0);
1079 exec_delay = strtoul(optarg, NULL, 0);
1083 if (udev_get_log_priority(udev) < LOG_INFO)
1084 udev_set_log_priority(udev, LOG_INFO);
1087 if (strcmp (optarg, "early") == 0) {
1089 } else if (strcmp (optarg, "late") == 0) {
1091 } else if (strcmp (optarg, "never") == 0) {
1094 fprintf(stderr, "resolve-names must be early, late or never\n");
1095 err(udev, "resolve-names must be early, late or never\n");
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);
1119 * read the kernel commandline, in case we need to get into debug mode
1120 * udev.log-priority=<level> syslog priority
1121 * udev.children-max=<number of workers> events are fully serialized if set to 1
1124 f = fopen("/proc/cmdline", "r");
1128 if (fgets(cmdline, sizeof(cmdline), f) != NULL) {
1131 pos = strstr(cmdline, "udev.log-priority=");
1133 pos += strlen("udev.log-priority=");
1134 udev_set_log_priority(udev, util_log_priority(pos));
1137 pos = strstr(cmdline, "udev.children-max=");
1139 pos += strlen("udev.children-max=");
1140 children_max = strtoul(pos, NULL, 0);
1143 pos = strstr(cmdline, "udev.exec-delay=");
1145 pos += strlen("udev.exec-delay=");
1146 exec_delay = strtoul(pos, NULL, 0);
1152 if (getuid() != 0) {
1153 fprintf(stderr, "root privileges required\n");
1154 err(udev, "root privileges required\n");
1158 /* set umask before creating any file/directory */
1162 /* before opening new files, make sure std{in,out,err} fds are in a sane state */
1163 fd = open("/dev/null", O_RDWR);
1165 fprintf(stderr, "cannot open /dev/null\n");
1166 err(udev, "cannot open /dev/null\n");
1168 if (write(STDOUT_FILENO, 0, 0) < 0)
1169 dup2(fd, STDOUT_FILENO);
1170 if (write(STDERR_FILENO, 0, 0) < 0)
1171 dup2(fd, STDERR_FILENO);
1173 udev_ctrl = udev_ctrl_new_from_socket(udev, UDEV_CTRL_SOCK_PATH);
1174 if (udev_ctrl == NULL) {
1175 fprintf(stderr, "error initializing control socket");
1176 err(udev, "error initializing udevd socket");
1180 if (udev_ctrl_enable_receiving(udev_ctrl) < 0) {
1181 fprintf(stderr, "error binding control socket, seems udevd is already running\n");
1182 err(udev, "error binding control socket, seems udevd is already running\n");
1186 pfd[FD_CONTROL].fd = udev_ctrl_get_fd(udev_ctrl);
1188 monitor = udev_monitor_new_from_netlink(udev, "kernel");
1189 if (monitor == NULL || udev_monitor_enable_receiving(monitor) < 0) {
1190 fprintf(stderr, "error initializing netlink socket\n");
1191 err(udev, "error initializing netlink socket\n");
1195 udev_monitor_set_receive_buffer_size(monitor, 128*1024*1024);
1196 pfd[FD_NETLINK].fd = udev_monitor_get_fd(monitor);
1198 pfd[FD_INOTIFY].fd = udev_watch_init(udev);
1199 if (pfd[FD_INOTIFY].fd < 0) {
1200 fprintf(stderr, "error initializing inotify\n");
1201 err(udev, "error initializing inotify\n");
1206 if (udev_get_rules_path(udev) != NULL) {
1207 inotify_add_watch(pfd[FD_INOTIFY].fd, udev_get_rules_path(udev),
1208 IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
1210 char filename[UTIL_PATH_SIZE];
1211 struct stat statbuf;
1213 inotify_add_watch(pfd[FD_INOTIFY].fd, LIBEXECDIR "/rules.d",
1214 IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
1215 inotify_add_watch(pfd[FD_INOTIFY].fd, SYSCONFDIR "/udev/rules.d",
1216 IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
1218 /* watch dynamic rules directory */
1219 util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev), "/.udev/rules.d", NULL);
1220 if (stat(filename, &statbuf) != 0) {
1221 util_create_path(udev, filename);
1222 udev_selinux_setfscreatecon(udev, filename, S_IFDIR|0755);
1223 mkdir(filename, 0755);
1224 udev_selinux_resetfscreatecon(udev);
1226 inotify_add_watch(pfd[FD_INOTIFY].fd, filename,
1227 IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
1229 udev_watch_restore(udev);
1231 /* block and listen to all signals on signalfd */
1233 sigprocmask(SIG_SETMASK, &mask, &orig_sigmask);
1234 pfd[FD_SIGNAL].fd = signalfd(-1, &mask, 0);
1235 if (pfd[FD_SIGNAL].fd < 0) {
1236 fprintf(stderr, "error getting signalfd\n");
1237 err(udev, "error getting signalfd\n");
1242 /* unnamed socket from workers to the main daemon */
1243 if (socketpair(AF_LOCAL, SOCK_DGRAM|SOCK_CLOEXEC, 0, worker_watch) < 0) {
1244 fprintf(stderr, "error getting socketpair\n");
1245 err(udev, "error getting socketpair\n");
1249 pfd[FD_WORKER].fd = worker_watch[READ_END];
1251 rules = udev_rules_new(udev, resolve_names);
1252 if (rules == NULL) {
1253 err(udev, "error reading rules\n");
1257 udev_queue_export = udev_queue_export_new(udev);
1258 if (udev_queue_export == NULL) {
1259 err(udev, "error creating queue file\n");
1264 dup2(fd, STDIN_FILENO);
1265 dup2(fd, STDOUT_FILENO);
1266 dup2(fd, STDERR_FILENO);
1268 if (fd > STDERR_FILENO)
1279 err(udev, "fork of daemon failed: %m\n");
1287 init_notify("READY=1");
1290 /* set scheduling priority for the main daemon process */
1291 setpriority(PRIO_PROCESS, 0, UDEVD_PRIORITY);
1295 f = fopen("/dev/kmsg", "w");
1297 fprintf(f, "<6>udev: starting version " VERSION "\n");
1301 /* OOM_DISABLE == -17 */
1302 fd = open("/proc/self/oom_adj", O_RDWR);
1304 err(udev, "error disabling OOM: %m\n");
1306 write(fd, "-17", 3);
1310 if (children_max <= 0) {
1311 int memsize = mem_size_mb();
1313 /* set value depending on the amount of RAM */
1315 children_max = 128 + (memsize / 8);
1319 info(udev, "set children_max to %u\n", children_max);
1321 static_dev_create(udev);
1322 static_dev_create_from_modules(udev);
1323 udev_rules_apply_static_dev_perms(rules);
1325 udev_list_init(&event_list);
1326 udev_list_init(&worker_list);
1328 while (!udev_exit) {
1332 /* set timeout to kill idle workers */
1333 if (udev_list_is_empty(&event_list) && children > 2)
1337 /* wait for events */
1338 fdcount = poll(pfd, ARRAY_SIZE(pfd), timeout);
1342 /* timeout - kill idle workers */
1344 worker_kill(udev, 2);
1346 /* event has finished */
1347 if (pfd[FD_WORKER].revents & POLLIN)
1350 /* get kernel uevent */
1351 if (pfd[FD_NETLINK].revents & POLLIN) {
1352 struct udev_device *dev;
1354 dev = udev_monitor_receive_device(monitor);
1356 if (event_queue_insert(dev) < 0)
1357 udev_device_unref(dev);
1360 /* start new events */
1361 if (!udev_list_is_empty(&event_list) && !stop_exec_queue)
1365 if (pfd[FD_SIGNAL].revents & POLLIN) {
1366 struct signalfd_siginfo fdsi;
1369 size = read(pfd[FD_SIGNAL].fd, &fdsi, sizeof(struct signalfd_siginfo));
1370 if (size == sizeof(struct signalfd_siginfo))
1371 handle_signal(udev, fdsi.ssi_signo);
1374 /* device node and rules directory inotify watch */
1375 if (pfd[FD_INOTIFY].revents & POLLIN)
1376 handle_inotify(udev);
1379 * get control message
1381 * This needs to be after the inotify handling, to make sure,
1382 * that the settle signal is send back after the possibly generated
1383 * "change" events by the inotify device node watch.
1385 if (pfd[FD_CONTROL].revents & POLLIN)
1386 handle_ctrl_msg(udev_ctrl);
1388 /* rules changed, set by inotify or a HUP signal */
1389 if (reload_config) {
1390 struct udev_rules *rules_new;
1392 worker_kill(udev, 0);
1393 rules_new = udev_rules_new(udev, resolve_names);
1394 if (rules_new != NULL) {
1395 udev_rules_unref(rules);
1402 udev_queue_export_cleanup(udev_queue_export);
1405 udev_queue_export_unref(udev_queue_export);
1406 udev_rules_unref(rules);
1407 udev_ctrl_unref(udev_ctrl);
1408 if (pfd[FD_SIGNAL].fd >= 0)
1409 close(pfd[FD_SIGNAL].fd);
1410 if (worker_watch[READ_END] >= 0)
1411 close(worker_watch[READ_END]);
1412 if (worker_watch[WRITE_END] >= 0)
1413 close(worker_watch[WRITE_END]);
1414 udev_monitor_unref(monitor);
1415 udev_selinux_exit(udev);