2 * Copyright (C) 2004-2008 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/>.
33 #include <sys/select.h>
37 #include <sys/ioctl.h>
39 #include <sys/inotify.h>
44 #define UDEVD_PRIORITY -4
45 #define UDEV_PRIORITY -2
47 /* maximum limit of forked childs */
48 #define UDEVD_MAX_CHILDS 256
52 static void log_fn(struct udev *udev, int priority,
53 const char *file, int line, const char *fn,
54 const char *format, va_list args)
57 fprintf(stderr, "[%d] %s: ", (int) getpid(), fn);
58 vfprintf(stderr, format, args);
60 vsyslog(priority, format, args);
64 static void reap_sigchilds(void);
66 static int debug_trace;
67 static struct udev_rules *rules;
68 static struct udev_queue_export *udev_queue_export;
69 static struct udev_ctrl *udev_ctrl;
70 static struct udev_monitor *kernel_monitor;
71 static volatile sig_atomic_t sigchilds_waiting;
72 static volatile sig_atomic_t udev_exit;
73 static volatile sig_atomic_t reload_config;
74 static volatile sig_atomic_t signal_received;
75 static volatile pid_t settle_pid;
76 static int run_exec_q;
77 static int stop_exec_q;
78 static int max_childs;
80 static struct udev_list_node event_list;
82 static struct udev_event *node_to_event(struct udev_list_node *node)
87 event -= offsetof(struct udev_event, node);
88 return (struct udev_event *)event;
91 static void event_queue_delete(struct udev_event *event)
93 udev_list_node_remove(&event->node);
95 /* mark as failed, if "add" event returns non-zero */
96 if (event->exitstatus && strcmp(udev_device_get_action(event->dev), "add") == 0)
97 udev_queue_export_device_failed(udev_queue_export, event->dev);
99 udev_queue_export_device_finished(udev_queue_export, event->dev);
101 udev_device_unref(event->dev);
102 udev_event_unref(event);
105 static void event_sig_handler(int signum)
107 if (signum == SIGALRM)
111 static void event_fork(struct udev_event *event)
114 struct sigaction act;
118 /* single process, no forking, just for testing/profiling */
119 err = udev_event_execute_rules(event, rules);
120 if (err == 0 && !event->ignore_device && udev_get_run(event->udev))
121 udev_event_execute_run(event);
122 info(event->udev, "seq %llu exit with %i\n", udev_device_get_seqnum(event->dev), err);
123 event_queue_delete(event);
129 fprintf(stderr, "fork %s (%llu)\n",
130 udev_device_get_syspath(event->dev),
131 udev_device_get_seqnum(event->dev));
138 udev_queue_export_unref(udev_queue_export);
139 udev_ctrl_unref(udev_ctrl);
141 logging_init("udevd-event");
142 setpriority(PRIO_PROCESS, 0, UDEV_PRIORITY);
144 /* set signal handlers */
145 memset(&act, 0x00, sizeof(act));
146 act.sa_handler = event_sig_handler;
147 sigemptyset (&act.sa_mask);
149 sigaction(SIGALRM, &act, NULL);
151 /* reset to default */
152 act.sa_handler = SIG_DFL;
153 sigaction(SIGINT, &act, NULL);
154 sigaction(SIGTERM, &act, NULL);
155 sigaction(SIGCHLD, &act, NULL);
156 sigaction(SIGHUP, &act, NULL);
158 /* set timeout to prevent hanging processes */
159 alarm(UDEV_EVENT_TIMEOUT);
161 /* apply rules, create node, symlinks */
162 err = udev_event_execute_rules(event, rules);
164 /* rules may change/disable the timeout */
165 if (udev_device_get_event_timeout(event->dev) >= 0)
166 alarm(udev_device_get_event_timeout(event->dev));
169 if (err == 0 && !event->ignore_device && udev_get_run(event->udev))
170 udev_event_execute_run(event);
172 /* apply/restore inotify watch */
173 if (err == 0 && event->inotify_watch) {
174 udev_watch_begin(event->udev, event->dev);
175 udev_device_update_db(event->dev);
178 /* send processed event back to the kernel netlink socket */
179 udev_monitor_send_device(kernel_monitor, event->dev);
181 info(event->udev, "seq %llu exit with %i\n", udev_device_get_seqnum(event->dev), err);
187 err(event->udev, "fork of child failed: %m\n");
188 event_queue_delete(event);
191 /* get SIGCHLD in main loop */
192 info(event->udev, "seq %llu forked, pid [%d], '%s' '%s', %ld seconds old\n",
193 udev_device_get_seqnum(event->dev),
195 udev_device_get_action(event->dev),
196 udev_device_get_subsystem(event->dev),
197 time(NULL) - event->queue_time);
203 static void event_queue_insert(struct udev_event *event)
205 event->queue_time = time(NULL);
207 udev_queue_export_device_queued(udev_queue_export, event->dev);
208 info(event->udev, "seq %llu queued, '%s' '%s'\n", udev_device_get_seqnum(event->dev),
209 udev_device_get_action(event->dev), udev_device_get_subsystem(event->dev));
211 udev_list_node_append(&event->node, &event_list);
214 /* run all events with a timeout set immediately */
215 if (udev_device_get_timeout(event->dev) > 0) {
221 static int mem_size_mb(void)
225 long int memsize = -1;
227 f = fopen("/proc/meminfo", "r");
231 while (fgets(buf, sizeof(buf), f) != NULL) {
234 if (sscanf(buf, "MemTotal: %ld kB", &value) == 1) {
235 memsize = value / 1024;
244 static int compare_devpath(const char *running, const char *waiting)
248 while (running[i] != '\0' && running[i] == waiting[i])
251 /* identical device event found */
252 if (running[i] == '\0' && waiting[i] == '\0')
255 /* parent device event found */
256 if (running[i] == '\0' && waiting[i] == '/')
259 /* child device event found */
260 if (running[i] == '/' && waiting[i] == '\0')
263 /* no matching event */
267 /* lookup event for identical, parent, child device */
268 static int devpath_busy(struct udev_event *event)
270 struct udev_list_node *loop;
272 /* check if queue contains events we depend on */
273 udev_list_node_foreach(loop, &event_list) {
274 struct udev_event *loop_event = node_to_event(loop);
276 /* we already found a later event, earlier can not block us, no need to check again */
277 if (udev_device_get_seqnum(loop_event->dev) < event->delaying_seqnum)
280 /* event we checked earlier still exists, no need to check again */
281 if (udev_device_get_seqnum(loop_event->dev) == event->delaying_seqnum)
284 /* found ourself, no later event can block us */
285 if (udev_device_get_seqnum(loop_event->dev) >= udev_device_get_seqnum(event->dev))
288 /* check our old name */
289 if (udev_device_get_devpath_old(event->dev) != NULL)
290 if (strcmp(udev_device_get_devpath(loop_event->dev), udev_device_get_devpath_old(event->dev)) == 0) {
291 event->delaying_seqnum = udev_device_get_seqnum(loop_event->dev);
295 /* check identical, parent, or child device event */
296 if (compare_devpath(udev_device_get_devpath(loop_event->dev), udev_device_get_devpath(event->dev)) != 0) {
297 dbg(event->udev, "%llu, device event still pending %llu (%s)\n",
298 udev_device_get_seqnum(event->dev),
299 udev_device_get_seqnum(loop_event->dev),
300 udev_device_get_devpath(loop_event->dev));
301 event->delaying_seqnum = udev_device_get_seqnum(loop_event->dev);
305 /* check for our major:minor number */
306 if (major(udev_device_get_devnum(event->dev)) > 0 &&
307 udev_device_get_devnum(loop_event->dev) == udev_device_get_devnum(event->dev) &&
308 strcmp(udev_device_get_subsystem(event->dev), udev_device_get_subsystem(loop_event->dev)) == 0) {
309 dbg(event->udev, "%llu, device event still pending %llu (%d:%d)\n",
310 udev_device_get_seqnum(event->dev),
311 udev_device_get_seqnum(loop_event->dev),
312 major(udev_device_get_devnum(loop_event->dev)), minor(udev_device_get_devnum(loop_event->dev)));
313 event->delaying_seqnum = udev_device_get_seqnum(loop_event->dev);
320 /* serializes events for the identical and parent and child devices */
321 static void event_queue_manager(struct udev *udev)
323 struct udev_list_node *loop;
324 struct udev_list_node *tmp;
327 if (udev_list_is_empty(&event_list)) {
329 err(udev, "event list empty, but childs count is %i", childs);
335 udev_list_node_foreach_safe(loop, tmp, &event_list) {
336 struct udev_event *loop_event = node_to_event(loop);
338 if (childs >= max_childs) {
339 info(udev, "maximum number (%i) of childs reached\n", childs);
343 if (loop_event->pid != 0)
346 /* do not start event if parent or child event is still running */
347 if (devpath_busy(loop_event) != 0) {
348 dbg(udev, "delay seq %llu (%s)\n",
349 udev_device_get_seqnum(loop_event->dev),
350 udev_device_get_devpath(loop_event->dev));
354 event_fork(loop_event);
355 dbg(udev, "moved seq %llu to running list\n", udev_device_get_seqnum(loop_event->dev));
357 /* retry if events finished in the meantime */
358 if (sigchilds_waiting) {
359 sigchilds_waiting = 0;
366 /* receive the udevd message from userspace */
367 static void handle_ctrl_msg(struct udev_ctrl *uctrl)
369 struct udev *udev = udev_ctrl_get_udev(uctrl);
370 struct udev_ctrl_msg *ctrl_msg;
374 ctrl_msg = udev_ctrl_receive_msg(uctrl);
375 if (ctrl_msg == NULL)
378 i = udev_ctrl_get_set_log_level(ctrl_msg);
380 info(udev, "udevd message (SET_LOG_PRIORITY) received, log_priority=%i\n", i);
381 udev_set_log_priority(udev, i);
384 if (udev_ctrl_get_stop_exec_queue(ctrl_msg) > 0) {
385 info(udev, "udevd message (STOP_EXEC_QUEUE) received\n");
389 if (udev_ctrl_get_start_exec_queue(ctrl_msg) > 0) {
390 info(udev, "udevd message (START_EXEC_QUEUE) received\n");
392 event_queue_manager(udev);
395 if (udev_ctrl_get_reload_rules(ctrl_msg) > 0) {
396 info(udev, "udevd message (RELOAD_RULES) received\n");
400 str = udev_ctrl_get_set_env(ctrl_msg);
408 val = strchr(key, '=');
412 if (val[0] == '\0') {
413 info(udev, "udevd message (ENV) received, unset '%s'\n", key);
414 udev_add_property(udev, key, NULL);
416 info(udev, "udevd message (ENV) received, set '%s=%s'\n", key, val);
417 udev_add_property(udev, key, val);
420 err(udev, "wrong key format '%s'\n", key);
426 i = udev_ctrl_get_set_max_childs(ctrl_msg);
428 info(udev, "udevd message (SET_MAX_CHILDS) received, max_childs=%i\n", i);
432 settle_pid = udev_ctrl_get_settle(ctrl_msg);
433 if (settle_pid > 0) {
434 info(udev, "udevd message (SETTLE) received\n");
436 udev_ctrl_msg_unref(ctrl_msg);
439 /* read inotify messages */
440 static int handle_inotify(struct udev *udev)
444 struct inotify_event *ev;
446 if ((ioctl(inotify_fd, FIONREAD, &nbytes) < 0) || (nbytes <= 0))
449 buf = malloc(nbytes);
451 err(udev, "error getting buffer for inotify, disable watching\n");
457 read(inotify_fd, buf, nbytes);
459 for (pos = 0; pos < nbytes; pos += sizeof(struct inotify_event) + ev->len) {
460 struct udev_device *dev;
462 ev = (struct inotify_event *)(buf + pos);
464 dbg(udev, "inotify event: %x for %s\n", ev->mask, ev->name);
469 dev = udev_watch_lookup(udev, ev->wd);
471 dbg(udev, "inotify event: %x for %s\n", ev->mask, udev_device_get_devnode(dev));
472 if (ev->mask & IN_CLOSE_WRITE) {
473 char filename[UTIL_PATH_SIZE];
476 info(udev, "device %s closed, synthesising 'change'\n", udev_device_get_devnode(dev));
477 util_strscpyl(filename, sizeof(filename), udev_device_get_syspath(dev), "/uevent", NULL);
478 fd = open(filename, O_WRONLY);
479 if (fd < 0 || write(fd, "change", 6) < 0)
480 info(udev, "error writing uevent: %m\n");
483 if (ev->mask & IN_IGNORED)
484 udev_watch_end(udev, dev);
486 udev_device_unref(dev);
495 static void sig_handler(int signum)
503 /* set flag, then write to pipe if needed */
504 sigchilds_waiting = 1;
514 static void udev_done(int pid, int exitstatus)
516 struct udev_list_node *loop;
518 /* find event associated with pid and delete it */
519 udev_list_node_foreach(loop, &event_list) {
520 struct udev_event *loop_event = node_to_event(loop);
522 if (loop_event->pid == pid) {
523 info(loop_event->udev, "seq %llu cleanup, pid [%d], status %i, %ld seconds old\n",
524 udev_device_get_seqnum(loop_event->dev), loop_event->pid,
525 exitstatus, time(NULL) - loop_event->queue_time);
526 loop_event->exitstatus = exitstatus;
528 fprintf(stderr, "exit %s (%llu)\n",
529 udev_device_get_syspath(loop_event->dev),
530 udev_device_get_seqnum(loop_event->dev));
531 event_queue_delete(loop_event);
534 /* there may be dependent events waiting */
541 static void reap_sigchilds(void)
547 pid = waitpid(-1, &status, WNOHANG);
550 if (WIFEXITED(status))
551 status = WEXITSTATUS(status);
552 else if (WIFSIGNALED(status))
553 status = WTERMSIG(status) + 128;
556 udev_done(pid, status);
560 static void startup_log(struct udev *udev)
563 char path[UTIL_PATH_SIZE];
566 f = fopen("/dev/kmsg", "w");
568 fprintf(f, "<6>udev: starting version " VERSION "\n");
570 util_strscpyl(path, sizeof(path), udev_get_sys_path(udev), "/class/mem/null", NULL);
571 if (lstat(path, &statbuf) == 0 && S_ISDIR(statbuf.st_mode)) {
572 const char *depr_str =
573 "udev: missing sysfs features; please update the kernel "
574 "or disable the kernel's CONFIG_SYSFS_DEPRECATED option; "
575 "udev may fail to work correctly";
578 fprintf(f, "<3>%s\n", depr_str);
579 err(udev, "%s\n", depr_str);
587 int main(int argc, char *argv[])
591 struct sigaction act;
594 int resolve_names = 1;
595 static const struct option options[] = {
596 { "daemon", no_argument, NULL, 'd' },
597 { "debug-trace", no_argument, NULL, 't' },
598 { "debug", no_argument, NULL, 'D' },
599 { "help", no_argument, NULL, 'h' },
600 { "version", no_argument, NULL, 'V' },
601 { "resolve-names", required_argument, NULL, 'N' },
610 logging_init("udevd");
611 udev_set_log_fn(udev, log_fn);
612 info(udev, "version %s\n", VERSION);
613 udev_selinux_init(udev);
618 option = getopt_long(argc, argv, "dDthV", options, NULL);
631 if (udev_get_log_priority(udev) < LOG_INFO)
632 udev_set_log_priority(udev, LOG_INFO);
635 if (strcmp (optarg, "early") == 0) {
637 } else if (strcmp (optarg, "late") == 0) {
639 } else if (strcmp (optarg, "never") == 0) {
642 fprintf(stderr, "resolve-names must be early, late or never\n");
643 err(udev, "resolve-names must be early, late or never\n");
648 printf("Usage: udevd [--help] [--daemon] [--debug-trace] [--debug] "
649 "[--resolve-names=early|late|never] [--version]\n");
652 printf("%s\n", VERSION);
660 fprintf(stderr, "root privileges required\n");
661 err(udev, "root privileges required\n");
665 /* make sure std{in,out,err} fd's are in a sane state */
666 fd = open("/dev/null", O_RDWR);
668 fprintf(stderr, "cannot open /dev/null\n");
669 err(udev, "cannot open /dev/null\n");
671 if (write(STDOUT_FILENO, 0, 0) < 0)
672 dup2(fd, STDOUT_FILENO);
673 if (write(STDERR_FILENO, 0, 0) < 0)
674 dup2(fd, STDERR_FILENO);
676 /* init control socket, bind() ensures, that only one udevd instance is running */
677 udev_ctrl = udev_ctrl_new_from_socket(udev, UDEV_CTRL_SOCK_PATH);
678 if (udev_ctrl == NULL) {
679 fprintf(stderr, "error initializing control socket");
680 err(udev, "error initializing udevd socket");
685 if (udev_ctrl_enable_receiving(udev_ctrl) < 0) {
686 fprintf(stderr, "error binding control socket, seems udevd is already running\n");
687 err(udev, "error binding control socket, seems udevd is already running\n");
692 kernel_monitor = udev_monitor_new_from_netlink(udev, "kernel");
693 if (kernel_monitor == NULL || udev_monitor_enable_receiving(kernel_monitor) < 0) {
694 fprintf(stderr, "error initializing netlink socket\n");
695 err(udev, "error initializing netlink socket\n");
699 udev_monitor_set_receive_buffer_size(kernel_monitor, 128*1024*1024);
701 rules = udev_rules_new(udev, resolve_names);
703 err(udev, "error reading rules\n");
706 udev_list_init(&event_list);
707 udev_queue_export = udev_queue_export_new(udev);
708 if (udev_queue_export == NULL) {
709 err(udev, "error creating queue file\n");
719 dbg(udev, "daemonized fork running\n");
722 err(udev, "fork of daemon failed: %m\n");
726 dbg(udev, "child [%u] running, parent exits\n", pid);
732 /* redirect std{out,err} */
733 if (!debug && !debug_trace) {
734 dup2(fd, STDIN_FILENO);
735 dup2(fd, STDOUT_FILENO);
736 dup2(fd, STDERR_FILENO);
738 if (fd > STDERR_FILENO)
741 /* set scheduling priority for the daemon */
742 setpriority(PRIO_PROCESS, 0, UDEVD_PRIORITY);
748 /* OOM_DISABLE == -17 */
749 fd = open("/proc/self/oom_adj", O_RDWR);
751 err(udev, "error disabling OOM: %m\n");
759 /* set signal handlers */
760 memset(&act, 0x00, sizeof(struct sigaction));
761 act.sa_handler = sig_handler;
762 sigemptyset(&act.sa_mask);
763 act.sa_flags = SA_RESTART;
764 sigaction(SIGINT, &act, NULL);
765 sigaction(SIGTERM, &act, NULL);
766 sigaction(SIGCHLD, &act, NULL);
767 sigaction(SIGHUP, &act, NULL);
769 /* watch rules directory */
770 udev_watch_init(udev);
771 if (inotify_fd >= 0) {
772 if (udev_get_rules_path(udev) != NULL) {
773 inotify_add_watch(inotify_fd, udev_get_rules_path(udev),
774 IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
776 char filename[UTIL_PATH_SIZE];
778 inotify_add_watch(inotify_fd, UDEV_PREFIX "/lib/udev/rules.d",
779 IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
780 inotify_add_watch(inotify_fd, SYSCONFDIR "/udev/rules.d",
781 IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
783 /* watch dynamic rules directory */
784 util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev), "/.udev/rules.d", NULL);
785 inotify_add_watch(inotify_fd, filename,
786 IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
789 udev_watch_restore(udev);
792 /* in trace mode run one event after the other */
796 int memsize = mem_size_mb();
798 max_childs = 128 + (memsize / 4);
800 max_childs = UDEVD_MAX_CHILDS;
802 /* possibly overwrite maximum limit of executed events */
803 value = getenv("UDEVD_MAX_CHILDS");
805 max_childs = strtoul(value, NULL, 10);
806 info(udev, "initialize max_childs to %u\n", max_childs);
809 sigset_t blocked_mask, orig_mask;
810 struct pollfd pfd[4];
811 struct pollfd *ctrl_poll, *monitor_poll, *inotify_poll = NULL;
815 sigfillset(&blocked_mask);
816 sigprocmask(SIG_SETMASK, &blocked_mask, &orig_mask);
817 if (signal_received) {
818 sigprocmask(SIG_SETMASK, &orig_mask, NULL);
822 ctrl_poll = &pfd[nfds++];
823 ctrl_poll->fd = udev_ctrl_get_fd(udev_ctrl);
824 ctrl_poll->events = POLLIN;
826 monitor_poll = &pfd[nfds++];
827 monitor_poll->fd = udev_monitor_get_fd(kernel_monitor);
828 monitor_poll->events = POLLIN;
830 if (inotify_fd >= 0) {
831 inotify_poll = &pfd[nfds++];
832 inotify_poll->fd = inotify_fd;
833 inotify_poll->events = POLLIN;
836 fdcount = ppoll(pfd, nfds, NULL, &orig_mask);
837 sigprocmask(SIG_SETMASK, &orig_mask, NULL);
841 err(udev, "error in select: %m\n");
845 /* get control message */
846 if (ctrl_poll->revents & POLLIN)
847 handle_ctrl_msg(udev_ctrl);
849 /* get kernel uevent */
850 if (monitor_poll->revents & POLLIN) {
851 struct udev_device *dev;
853 dev = udev_monitor_receive_device(kernel_monitor);
855 struct udev_event *event;
857 event = udev_event_new(dev);
859 event_queue_insert(event);
861 udev_device_unref(dev);
865 /* rules directory inotify watch */
866 if (inotify_poll && (inotify_poll->revents & POLLIN))
867 handle_inotify(udev);
872 /* rules changed, set by inotify or a HUP signal */
874 struct udev_rules *rules_new;
877 rules_new = udev_rules_new(udev, resolve_names);
878 if (rules_new != NULL) {
879 udev_rules_unref(rules);
884 if (sigchilds_waiting) {
885 sigchilds_waiting = 0;
892 event_queue_manager(udev);
895 if (settle_pid > 0) {
896 kill(settle_pid, SIGUSR1);
900 udev_queue_export_cleanup(udev_queue_export);
904 udev_queue_export_unref(udev_queue_export);
905 udev_rules_unref(rules);
906 udev_ctrl_unref(udev_ctrl);
909 udev_monitor_unref(kernel_monitor);
910 udev_selinux_exit(udev);