2 * Copyright (C) 2004-2008 Kay Sievers <kay.sievers@vrfy.org>
3 * Copyright (C) 2004 Chris Friesen <chris_friesen@sympatico.ca>
5 * This program is free software: you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation, either version 2 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program. If not, see <http://www.gnu.org/licenses/>.
30 #include <sys/select.h>
33 #include <sys/ioctl.h>
35 #include <sys/inotify.h>
40 #define UDEVD_PRIORITY -4
41 #define UDEV_PRIORITY -2
43 /* maximum limit of forked childs */
44 #define UDEVD_MAX_CHILDS 256
48 static void log_fn(struct udev *udev, int priority,
49 const char *file, int line, const char *fn,
50 const char *format, va_list args)
53 fprintf(stderr, "[%d] %s: ", (int) getpid(), fn);
54 vfprintf(stderr, format, args);
56 vsyslog(priority, format, args);
60 static int debug_trace;
61 static struct udev_rules *rules;
62 static struct udev_ctrl *udev_ctrl;
63 static struct udev_monitor *kernel_monitor;
64 static int inotify_fd = -1;
66 static int signal_pipe[2] = {-1, -1};
67 static volatile int sigchilds_waiting;
68 static volatile int udev_exit;
69 static volatile int reload_config;
70 static int run_exec_q;
71 static int stop_exec_q;
72 static int max_childs;
74 static struct udev_list_node exec_list;
75 static struct udev_list_node running_list;
83 static struct udev_event *node_to_event(struct udev_list_node *node)
88 event -= offsetof(struct udev_event, node);
89 return (struct udev_event *)event;
92 static void export_event_state(struct udev_event *event, enum event_state state)
94 char filename[UTIL_PATH_SIZE];
95 char filename_failed[UTIL_PATH_SIZE];
98 /* location of queue file */
99 snprintf(filename, sizeof(filename), "%s/.udev/queue/%llu",
100 udev_get_dev_path(event->udev), udev_device_get_seqnum(event->dev));
102 /* location of failed file */
103 util_strlcpy(filename_failed, udev_get_dev_path(event->udev), sizeof(filename_failed));
104 util_strlcat(filename_failed, "/", sizeof(filename_failed));
105 start = util_strlcat(filename_failed, ".udev/failed/", sizeof(filename_failed));
106 util_strlcat(filename_failed, udev_device_get_devpath(event->dev), sizeof(filename_failed));
107 util_path_encode(&filename_failed[start], sizeof(filename_failed) - start);
111 if(unlink(filename_failed) == 0)
112 util_delete_path(event->udev, filename_failed);
113 util_create_path(event->udev, filename);
114 udev_selinux_setfscreatecon(event->udev, filename, S_IFLNK);
115 symlink(udev_device_get_devpath(event->dev), filename);
116 udev_selinux_resetfscreatecon(event->udev);
119 if (udev_device_get_devpath_old(event->dev) != NULL) {
120 /* "move" event - rename failed file to current name, do not delete failed */
121 char filename_failed_old[UTIL_PATH_SIZE];
123 util_strlcpy(filename_failed_old, udev_get_dev_path(event->udev), sizeof(filename_failed_old));
124 util_strlcat(filename_failed_old, "/", sizeof(filename_failed_old));
125 start = util_strlcat(filename_failed_old, ".udev/failed/", sizeof(filename_failed_old));
126 util_strlcat(filename_failed_old, udev_device_get_devpath_old(event->dev), sizeof(filename_failed_old));
127 util_path_encode(&filename_failed_old[start], sizeof(filename) - start);
129 if (rename(filename_failed_old, filename_failed) == 0)
130 info(event->udev, "renamed devpath, moved failed state of '%s' to %s'\n",
131 udev_device_get_devpath_old(event->dev), udev_device_get_devpath(event->dev));
133 if (unlink(filename_failed) == 0)
134 util_delete_path(event->udev, filename_failed);
139 /* clean up possibly empty queue directory */
140 if (udev_list_is_empty(&exec_list) && udev_list_is_empty(&running_list))
141 util_delete_path(event->udev, filename);
144 /* move failed event to the failed directory */
145 util_create_path(event->udev, filename_failed);
146 rename(filename, filename_failed);
148 /* clean up possibly empty queue directory */
149 if (udev_list_is_empty(&exec_list) && udev_list_is_empty(&running_list))
150 util_delete_path(event->udev, filename);
157 static void event_queue_delete(struct udev_event *event)
159 udev_list_node_remove(&event->node);
161 /* mark as failed, if "add" event returns non-zero */
162 if (event->exitstatus && strcmp(udev_device_get_action(event->dev), "add") == 0)
163 export_event_state(event, EVENT_FAILED);
165 export_event_state(event, EVENT_FINISHED);
167 udev_device_unref(event->dev);
168 udev_event_unref(event);
171 static void asmlinkage event_sig_handler(int signum)
173 if (signum == SIGALRM)
177 static void event_fork(struct udev_event *event)
180 struct sigaction act;
187 udev_monitor_unref(kernel_monitor);
188 udev_ctrl_unref(udev_ctrl);
191 close(signal_pipe[READ_END]);
192 close(signal_pipe[WRITE_END]);
194 logging_init("udevd-event");
195 setpriority(PRIO_PROCESS, 0, UDEV_PRIORITY);
197 /* set signal handlers */
198 memset(&act, 0x00, sizeof(act));
199 act.sa_handler = (void (*)(int)) event_sig_handler;
200 sigemptyset (&act.sa_mask);
202 sigaction(SIGALRM, &act, NULL);
204 /* reset to default */
205 act.sa_handler = SIG_DFL;
206 sigaction(SIGINT, &act, NULL);
207 sigaction(SIGTERM, &act, NULL);
208 sigaction(SIGCHLD, &act, NULL);
209 sigaction(SIGHUP, &act, NULL);
211 /* set timeout to prevent hanging processes */
212 alarm(UDEV_EVENT_TIMEOUT);
214 /* apply rules, create node, symlinks */
215 err = udev_event_execute_rules(event, rules);
217 /* rules may change/disable the timeout */
218 if (udev_device_get_event_timeout(event->dev) >= 0)
219 alarm(udev_device_get_event_timeout(event->dev));
222 if (err == 0 && !event->ignore_device && udev_get_run(event->udev))
223 udev_event_execute_run(event);
224 info(event->udev, "seq %llu exit with %i\n", udev_device_get_seqnum(event->dev), err);
230 err(event->udev, "fork of child failed: %m\n");
231 event_queue_delete(event);
234 /* get SIGCHLD in main loop */
235 info(event->udev, "seq %llu forked, pid [%d], '%s' '%s', %ld seconds old\n",
236 udev_device_get_seqnum(event->dev),
238 udev_device_get_action(event->dev),
239 udev_device_get_subsystem(event->dev),
240 time(NULL) - event->queue_time);
245 static void event_queue_insert(struct udev_event *event)
247 char filename[UTIL_PATH_SIZE];
250 event->queue_time = time(NULL);
252 export_event_state(event, EVENT_QUEUED);
253 info(event->udev, "seq %llu queued, '%s' '%s'\n", udev_device_get_seqnum(event->dev),
254 udev_device_get_action(event->dev), udev_device_get_subsystem(event->dev));
256 util_strlcpy(filename, udev_get_dev_path(event->udev), sizeof(filename));
257 util_strlcat(filename, "/.udev/uevent_seqnum", sizeof(filename));
258 fd = open(filename, O_WRONLY|O_TRUNC|O_CREAT, 0644);
263 len = sprintf(str, "%llu\n", udev_device_get_seqnum(event->dev));
268 /* run one event after the other in debug mode */
270 udev_list_node_append(&event->node, &running_list);
272 waitpid(event->pid, NULL, 0);
273 event_queue_delete(event);
277 /* run all events with a timeout set immediately */
278 if (udev_device_get_timeout(event->dev) > 0) {
279 udev_list_node_append(&event->node, &running_list);
284 udev_list_node_append(&event->node, &exec_list);
288 static int mem_size_mb(void)
292 long int memsize = -1;
294 f = fopen("/proc/meminfo", "r");
298 while (fgets(buf, sizeof(buf), f) != NULL) {
301 if (sscanf(buf, "MemTotal: %ld kB", &value) == 1) {
302 memsize = value / 1024;
311 static int compare_devpath(const char *running, const char *waiting)
315 while (running[i] == waiting[i] && running[i] != '\0')
318 /* identical device event found */
319 if (running[i] == '\0' && waiting[i] == '\0')
322 /* parent device event found */
323 if (running[i] == '\0' && waiting[i] == '/')
326 /* child device event found */
327 if (running[i] == '/' && waiting[i] == '\0')
330 /* no matching event */
334 /* lookup event for identical, parent, child, or physical device */
335 static int devpath_busy(struct udev_event *event, int limit)
337 struct udev_list_node *loop;
338 int childs_count = 0;
340 /* check exec-queue which may still contain delayed events we depend on */
341 udev_list_node_foreach(loop, &exec_list) {
342 struct udev_event *loop_event = node_to_event(loop);
344 /* skip ourself and all later events */
345 if (udev_device_get_seqnum(loop_event->dev) >= udev_device_get_seqnum(event->dev))
348 /* check our old name */
349 if (udev_device_get_devpath_old(event->dev) != NULL)
350 if (strcmp(udev_device_get_devpath(loop_event->dev), udev_device_get_devpath_old(event->dev)) == 0)
353 /* check identical, parent, or child device event */
354 if (compare_devpath(udev_device_get_devpath(loop_event->dev), udev_device_get_devpath(event->dev)) != 0) {
355 dbg(event->udev, "%llu, device event still pending %llu (%s)\n",
356 udev_device_get_seqnum(event->dev),
357 udev_device_get_seqnum(loop_event->dev),
358 udev_device_get_devpath(loop_event->dev));
362 /* check for our major:minor number */
363 if (major(udev_device_get_devnum(event->dev)) > 0 &&
364 udev_device_get_devnum(loop_event->dev) == udev_device_get_devnum(event->dev) &&
365 strcmp(udev_device_get_subsystem(event->dev), udev_device_get_subsystem(loop_event->dev)) == 0) {
366 dbg(event->udev, "%llu, device event still pending %llu (%d:%d)\n",
367 udev_device_get_seqnum(event->dev),
368 udev_device_get_seqnum(loop_event->dev),
369 major(udev_device_get_devnum(loop_event->dev)), minor(udev_device_get_devnum(loop_event->dev)));
373 /* check physical device event (special case of parent) */
374 if (udev_device_get_physdevpath(event->dev) != NULL &&
375 strcmp(udev_device_get_action(event->dev), "add") == 0)
376 if (compare_devpath(udev_device_get_devpath(loop_event->dev),
377 udev_device_get_physdevpath(event->dev)) != 0) {
378 dbg(event->udev, "%llu, physical device event still pending %llu (%s)\n",
379 udev_device_get_seqnum(event->dev),
380 udev_device_get_seqnum(loop_event->dev),
381 udev_device_get_devpath(loop_event->dev));
386 /* check run queue for still running events */
387 udev_list_node_foreach(loop, &running_list) {
388 struct udev_event *loop_event = node_to_event(loop);
390 if (childs_count++ >= limit) {
391 info(event->udev, "%llu, maximum number (%i) of childs reached\n",
392 udev_device_get_seqnum(event->dev), childs_count);
396 /* check our old name */
397 if (udev_device_get_devpath_old(event->dev) != NULL)
398 if (strcmp(udev_device_get_devpath(loop_event->dev), udev_device_get_devpath_old(event->dev)) == 0)
401 /* check identical, parent, or child device event */
402 if (compare_devpath(udev_device_get_devpath(loop_event->dev), udev_device_get_devpath(event->dev)) != 0) {
403 dbg(event->udev, "%llu, device event still running %llu (%s)\n",
404 udev_device_get_seqnum(event->dev),
405 udev_device_get_seqnum(loop_event->dev),
406 udev_device_get_devpath(loop_event->dev));
410 /* check for our major:minor number */
411 if (major(udev_device_get_devnum(event->dev)) > 0 &&
412 udev_device_get_devnum(loop_event->dev) == udev_device_get_devnum(event->dev) &&
413 strcmp(udev_device_get_subsystem(event->dev), udev_device_get_subsystem(loop_event->dev)) == 0) {
414 dbg(event->udev, "%llu, device event still pending %llu (%d:%d)\n",
415 udev_device_get_seqnum(event->dev),
416 udev_device_get_seqnum(loop_event->dev),
417 major(udev_device_get_devnum(loop_event->dev)), minor(udev_device_get_devnum(loop_event->dev)));
421 /* check physical device event (special case of parent) */
422 if (udev_device_get_physdevpath(event->dev) != NULL &&
423 strcmp(udev_device_get_action(event->dev), "add") == 0)
424 if (compare_devpath(udev_device_get_devpath(loop_event->dev),
425 udev_device_get_physdevpath(event->dev)) != 0) {
426 dbg(event->udev, "%llu, physical device event still pending %llu (%s)\n",
427 udev_device_get_seqnum(event->dev),
428 udev_device_get_seqnum(loop_event->dev),
429 udev_device_get_devpath(loop_event->dev));
436 /* serializes events for the identical and parent and child devices */
437 static void event_queue_manager(struct udev *udev)
439 struct udev_list_node *loop;
440 struct udev_list_node *tmp;
442 if (udev_list_is_empty(&exec_list))
445 udev_list_node_foreach_safe(loop, tmp, &exec_list) {
446 struct udev_event *loop_event = node_to_event(loop);
448 /* serialize and wait for parent or child events */
449 if (devpath_busy(loop_event, max_childs) != 0) {
450 dbg(udev, "delay seq %llu (%s)\n",
451 udev_device_get_seqnum(loop_event->dev),
452 udev_device_get_devpath(loop_event->dev));
456 /* move event to run list */
457 udev_list_node_remove(&loop_event->node);
458 udev_list_node_append(&loop_event->node, &running_list);
459 event_fork(loop_event);
460 dbg(udev, "moved seq %llu to running list\n", udev_device_get_seqnum(loop_event->dev));
464 /* receive the udevd message from userspace */
465 static void handle_ctrl_msg(struct udev_ctrl *uctrl)
467 struct udev *udev = udev_ctrl_get_udev(uctrl);
468 struct udev_ctrl_msg *ctrl_msg;
472 ctrl_msg = udev_ctrl_receive_msg(uctrl);
473 if (ctrl_msg == NULL)
476 i = udev_ctrl_get_set_log_level(ctrl_msg);
478 info(udev, "udevd message (SET_LOG_PRIORITY) received, log_priority=%i\n", i);
479 udev_set_log_priority(udev, i);
482 if (udev_ctrl_get_stop_exec_queue(ctrl_msg) > 0) {
483 info(udev, "udevd message (STOP_EXEC_QUEUE) received\n");
487 if (udev_ctrl_get_start_exec_queue(ctrl_msg) > 0) {
488 info(udev, "udevd message (START_EXEC_QUEUE) received\n");
490 event_queue_manager(udev);
493 if (udev_ctrl_get_reload_rules(ctrl_msg) > 0) {
494 info(udev, "udevd message (RELOAD_RULES) received\n");
498 str = udev_ctrl_get_set_env(ctrl_msg);
506 val = strchr(key, '=');
510 if (val[0] == '\0') {
511 info(udev, "udevd message (ENV) received, unset '%s'\n", key);
512 udev_add_property(udev, key, NULL);
514 info(udev, "udevd message (ENV) received, set '%s=%s'\n", key, val);
515 udev_add_property(udev, key, val);
518 err(udev, "wrong key format '%s'\n", key);
524 i = udev_ctrl_get_set_max_childs(ctrl_msg);
526 info(udev, "udevd message (SET_MAX_CHILDS) received, max_childs=%i\n", i);
530 udev_ctrl_msg_unref(ctrl_msg);
533 static void asmlinkage sig_handler(int signum)
541 /* set flag, then write to pipe if needed */
542 sigchilds_waiting = 1;
549 /* write to pipe, which will wakeup select() in our mainloop */
550 write(signal_pipe[WRITE_END], "", 1);
553 static void udev_done(int pid, int exitstatus)
555 struct udev_list_node *loop;
557 /* find event associated with pid and delete it */
558 udev_list_node_foreach(loop, &running_list) {
559 struct udev_event *loop_event = node_to_event(loop);
561 if (loop_event->pid == pid) {
562 info(loop_event->udev, "seq %llu cleanup, pid [%d], status %i, %ld seconds old\n",
563 udev_device_get_seqnum(loop_event->dev), loop_event->pid,
564 exitstatus, time(NULL) - loop_event->queue_time);
565 loop_event->exitstatus = exitstatus;
566 event_queue_delete(loop_event);
568 /* there may be events waiting with the same devpath */
575 static void reap_sigchilds(void)
581 pid = waitpid(-1, &status, WNOHANG);
584 if (WIFEXITED(status))
585 status = WEXITSTATUS(status);
586 else if (WIFSIGNALED(status))
587 status = WTERMSIG(status) + 128;
590 udev_done(pid, status);
594 static void export_initial_seqnum(struct udev *udev)
596 char filename[UTIL_PATH_SIZE];
601 util_strlcpy(filename, udev_get_sys_path(udev), sizeof(filename));
602 util_strlcat(filename, "/kernel/uevent_seqnum", sizeof(filename));
603 fd = open(filename, O_RDONLY);
605 len = read(fd, seqnum, sizeof(seqnum)-1);
609 strcpy(seqnum, "0\n");
612 util_strlcpy(filename, udev_get_dev_path(udev), sizeof(filename));
613 util_strlcat(filename, "/.udev/uevent_seqnum", sizeof(filename));
614 util_create_path(udev, filename);
615 fd = open(filename, O_WRONLY|O_TRUNC|O_CREAT, 0644);
617 write(fd, seqnum, len);
622 int main(int argc, char *argv[])
627 struct sigaction act;
631 static const struct option options[] = {
632 { "daemon", no_argument, NULL, 'd' },
633 { "debug-trace", no_argument, NULL, 't' },
634 { "debug", no_argument, NULL, 'D' },
635 { "help", no_argument, NULL, 'h' },
636 { "version", no_argument, NULL, 'V' },
646 logging_init("udevd");
647 udev_set_log_fn(udev, log_fn);
648 info(udev, "version %s\n", VERSION);
649 udev_selinux_init(udev);
654 option = getopt_long(argc, argv, "dDthV", options, NULL);
667 if (udev_get_log_priority(udev) < LOG_INFO)
668 udev_set_log_priority(udev, LOG_INFO);
671 printf("Usage: udevd [--help] [--daemon] [--debug-trace] [--debug] [--version]\n");
674 printf("%s\n", VERSION);
682 fprintf(stderr, "root privileges required\n");
683 err(udev, "root privileges required\n");
687 /* make sure std{in,out,err} fd's are in a sane state */
688 fd = open("/dev/null", O_RDWR);
690 fprintf(stderr, "cannot open /dev/null\n");
691 err(udev, "cannot open /dev/null\n");
693 if (fd > STDIN_FILENO)
694 dup2(fd, STDIN_FILENO);
695 if (write(STDOUT_FILENO, 0, 0) < 0)
696 dup2(fd, STDOUT_FILENO);
697 if (write(STDERR_FILENO, 0, 0) < 0)
698 dup2(fd, STDERR_FILENO);
700 /* init control socket, bind() ensures, that only one udevd instance is running */
701 udev_ctrl = udev_ctrl_new_from_socket(udev, UDEV_CTRL_SOCK_PATH);
702 if (udev_ctrl == NULL) {
703 fprintf(stderr, "error initializing control socket");
704 err(udev, "error initializing udevd socket");
709 if (udev_ctrl_enable_receiving(udev_ctrl) < 0) {
710 fprintf(stderr, "error binding control socket, seems udevd is already running\n");
711 err(udev, "error binding control socket, seems udevd is already running\n");
716 kernel_monitor = udev_monitor_new_from_netlink(udev);
717 if (kernel_monitor == NULL || udev_monitor_enable_receiving(kernel_monitor) < 0) {
718 fprintf(stderr, "error initializing netlink socket\n");
719 err(udev, "error initializing netlink socket\n");
723 udev_monitor_set_receive_buffer_size(kernel_monitor, 128*1024*1024);
725 err = pipe(signal_pipe);
727 err(udev, "error getting pipes: %m\n");
731 err = fcntl(signal_pipe[READ_END], F_GETFL, 0);
733 err(udev, "error fcntl on read pipe: %m\n");
736 err = fcntl(signal_pipe[READ_END], F_SETFL, err | O_NONBLOCK);
738 err(udev, "error fcntl on read pipe: %m\n");
742 err = fcntl(signal_pipe[WRITE_END], F_GETFL, 0);
744 err(udev, "error fcntl on write pipe: %m\n");
747 err = fcntl(signal_pipe[WRITE_END], F_SETFL, err | O_NONBLOCK);
749 err(udev, "error fcntl on write pipe: %m\n");
753 rules = udev_rules_new(udev, 1);
755 err(udev, "error reading rules\n");
758 udev_list_init(&running_list);
759 udev_list_init(&exec_list);
760 export_initial_seqnum(udev);
768 dbg(udev, "daemonized fork running\n");
771 err(udev, "fork of daemon failed: %m\n");
775 dbg(udev, "child [%u] running, parent exits\n", pid);
781 /* redirect std{out,err} */
783 dup2(fd, STDOUT_FILENO);
784 dup2(fd, STDERR_FILENO);
786 if (fd > STDERR_FILENO)
789 /* set scheduling priority for the daemon */
790 setpriority(PRIO_PROCESS, 0, UDEVD_PRIORITY);
796 /* OOM_DISABLE == -17 */
797 fd = open("/proc/self/oom_adj", O_RDWR);
799 err(udev, "error disabling OOM: %m\n");
805 fd = open("/dev/kmsg", O_WRONLY);
807 const char *ver_str = "<6>udev: starting version " VERSION "\n";
808 char path[UTIL_PATH_SIZE];
811 write(fd, ver_str, strlen(ver_str));
812 util_strlcpy(path, udev_get_sys_path(udev), sizeof(path));
813 util_strlcat(path, "/class/mem/null", sizeof(path));
814 if (lstat(path, &statbuf) == 0) {
815 if (S_ISDIR(statbuf.st_mode)) {
816 const char *depr_str = "<6>udev: deprecated sysfs layout (kernel too old, "
817 "or CONFIG_SYSFS_DEPRECATED) is unsupported, some "
818 "udev features may fail\n";
820 write(fd, depr_str, strlen(depr_str));
826 /* set signal handlers */
827 memset(&act, 0x00, sizeof(struct sigaction));
828 act.sa_handler = (void (*)(int)) sig_handler;
829 sigemptyset(&act.sa_mask);
830 act.sa_flags = SA_RESTART;
831 sigaction(SIGINT, &act, NULL);
832 sigaction(SIGTERM, &act, NULL);
833 sigaction(SIGCHLD, &act, NULL);
834 sigaction(SIGHUP, &act, NULL);
836 /* watch rules directory */
837 inotify_fd = inotify_init();
838 if (inotify_fd >= 0) {
839 if (udev_get_rules_path(udev) != NULL) {
840 inotify_add_watch(inotify_fd, udev_get_rules_path(udev),
841 IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
843 char filename[PATH_MAX];
845 inotify_add_watch(inotify_fd, UDEV_PREFIX "/lib/udev/rules.d",
846 IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
847 inotify_add_watch(inotify_fd, SYSCONFDIR "/udev/rules.d",
848 IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
850 /* watch dynamic rules directory */
851 util_strlcpy(filename, udev_get_dev_path(udev), sizeof(filename));
852 util_strlcat(filename, "/.udev/rules.d", sizeof(filename));
853 inotify_add_watch(inotify_fd, filename,
854 IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
856 } else if (errno == ENOSYS)
857 err(udev, "the kernel does not support inotify, udevd can't monitor rules file changes\n");
859 err(udev, "inotify_init failed: %m\n");
861 /* maximum limit of forked childs */
862 value = getenv("UDEVD_MAX_CHILDS");
864 max_childs = strtoul(value, NULL, 10);
866 int memsize = mem_size_mb();
868 max_childs = 128 + (memsize / 4);
870 max_childs = UDEVD_MAX_CHILDS;
872 info(udev, "initialize max_childs to %u\n", max_childs);
874 maxfd = udev_ctrl_get_fd(udev_ctrl);
875 maxfd = UDEV_MAX(maxfd, udev_monitor_get_fd(kernel_monitor));
876 maxfd = UDEV_MAX(maxfd, signal_pipe[READ_END]);
877 maxfd = UDEV_MAX(maxfd, inotify_fd);
882 FD_SET(signal_pipe[READ_END], &readfds);
883 FD_SET(udev_ctrl_get_fd(udev_ctrl), &readfds);
884 FD_SET(udev_monitor_get_fd(kernel_monitor), &readfds);
886 FD_SET(inotify_fd, &readfds);
887 fdcount = select(maxfd+1, &readfds, NULL, NULL, NULL);
890 err(udev, "error in select: %m\n");
894 /* get control message */
895 if (FD_ISSET(udev_ctrl_get_fd(udev_ctrl), &readfds))
896 handle_ctrl_msg(udev_ctrl);
898 /* get kernel uevent */
899 if (FD_ISSET(udev_monitor_get_fd(kernel_monitor), &readfds)) {
900 struct udev_device *dev;
902 dev = udev_monitor_receive_device(kernel_monitor);
904 struct udev_event *event;
906 event = udev_event_new(dev);
908 event_queue_insert(event);
910 udev_device_unref(dev);
914 /* received a signal, clear our notification pipe */
915 if (FD_ISSET(signal_pipe[READ_END], &readfds)) {
918 read(signal_pipe[READ_END], &buf, sizeof(buf));
921 /* rules directory inotify watch */
922 if ((inotify_fd >= 0) && FD_ISSET(inotify_fd, &readfds)) {
925 /* discard all possible events, we can just reload the config */
926 if ((ioctl(inotify_fd, FIONREAD, &nbytes) == 0) && nbytes > 0) {
930 buf = malloc(nbytes);
932 err(udev, "error getting buffer for inotify, disable watching\n");
936 read(inotify_fd, buf, nbytes);
941 /* rules changed, set by inotify or a HUP signal */
943 struct udev_rules *rules_new;
946 rules_new = udev_rules_new(udev, 1);
947 if (rules_new != NULL) {
948 udev_rules_unref(rules);
953 if (sigchilds_waiting) {
954 sigchilds_waiting = 0;
961 event_queue_manager(udev);
967 udev_rules_unref(rules);
969 if (signal_pipe[READ_END] >= 0)
970 close(signal_pipe[READ_END]);
971 if (signal_pipe[WRITE_END] >= 0)
972 close(signal_pipe[WRITE_END]);
974 udev_ctrl_unref(udev_ctrl);
977 udev_monitor_unref(kernel_monitor);
979 udev_selinux_exit(udev);