X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=udevd.c;h=5ff5d3f66faab2f5876946c99c00b2f6131e5b35;hp=2b3dc55788f3e2915c7edf6644e7810b7c062dac;hb=1113044be205f9d78642744ffaa01329a77bee79;hpb=e964c2c05d3d6e2bdb21b3461ed7a4e85315cbc1

diff --git a/udevd.c b/udevd.c
index 2b3dc5578..5ff5d3f66 100644
--- a/udevd.c
+++ b/udevd.c
@@ -1,10 +1,7 @@
 /*
- * udevd.c - hotplug event serializer
- *
- * Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org>
+ * Copyright (C) 2004-2006 Kay Sievers <kay.sievers@vrfy.org>
  * Copyright (C) 2004 Chris Friesen <chris_friesen@sympatico.ca>
  *
- *
  *	This program is free software; you can redistribute it and/or modify it
  *	under the terms of the GNU General Public License as published by the
  *	Free Software Foundation version 2 of the License.
@@ -16,231 +13,657 @@
  *
  *	You should have received a copy of the GNU General Public License along
  *	with this program; if not, write to the Free Software Foundation, Inc.,
- *	675 Mass Ave, Cambridge, MA 02139, USA.
+ *	51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  *
  */
 
 #include <stddef.h>
-#include <sys/wait.h>
 #include <signal.h>
 #include <unistd.h>
 #include <errno.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <ctype.h>
+#include <dirent.h>
+#include <fcntl.h>
+#include <syslog.h>
 #include <time.h>
+#include <getopt.h>
+#include <sys/select.h>
+#include <sys/wait.h>
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <sys/un.h>
-#include <sys/time.h>
+#include <sys/stat.h>
+#include <sys/ioctl.h>
+#include <linux/types.h>
+#include <linux/netlink.h>
 
-#include "list.h"
 #include "udev.h"
-#include "udev_version.h"
+#include "udev_rules.h"
 #include "udevd.h"
-#include "logging.h"
+#include "udev_selinux.h"
 
-static int expected_seqnum = 0;
-volatile static int children_waiting;
-volatile static int msg_q_timeout;
+static int debug_trace;
+static int verbose;
 
-LIST_HEAD(msg_list);
-LIST_HEAD(exec_list);
-LIST_HEAD(running_list);
+static struct udev_rules rules;
+static int udevd_sock = -1;
+static int uevent_netlink_sock = -1;
+static int inotify_fd = -1;
+static pid_t sid;
 
-static void exec_queue_manager(void);
-static void msg_queue_manager(void);
+static int signal_pipe[2] = {-1, -1};
+static volatile int sigchilds_waiting;
+static volatile int udev_exit;
+static volatile int reload_config;
+static int run_exec_q;
+static int stop_exec_q;
+static int max_childs;
+static int max_childs_running;
+static char udev_log[32];
 
-#ifdef LOG
-unsigned char logname[42];
-void log_message (int level, const char *format, ...)
-{
-	va_list	args;
+static LIST_HEAD(exec_list);
+static LIST_HEAD(running_list);
 
-	va_start(args, format);
-	vsyslog(level, format, args);
-	va_end(args);
-}
-#endif
 
-static void msg_dump_queue(void)
+#ifdef USE_LOG
+void log_message(int priority, const char *format, ...)
 {
-	struct hotplug_msg *msg;
+	va_list args;
+
+	if (priority > udev_log_priority)
+		return;
 
-	list_for_each_entry(msg, &msg_list, list)
-		dbg("sequence %d in queue", msg->seqnum);
+	if (verbose) {
+		printf("[%d] ", (int) getpid());
+		va_start(args, format);
+		vprintf(format, args);
+		va_end(args);
+		printf("\n");
+	} else {
+		va_start(args, format);
+		vsyslog(priority, format, args);
+		va_end(args);
+	}
 }
 
-static void msg_dump(struct hotplug_msg *msg)
+#endif
+
+static void asmlinkage udev_event_sig_handler(int signum)
 {
-	dbg("sequence %d, '%s', '%s', '%s'",
-	    msg->seqnum, msg->action, msg->devpath, msg->subsystem);
+	if (signum == SIGALRM)
+		exit(1);
 }
 
-static struct hotplug_msg *msg_create(void)
+static int udev_event_process(struct udevd_uevent_msg *msg)
 {
-	struct hotplug_msg *new_msg;
+	struct sigaction act;
+	struct udevice *udev;
+	int i;
+	int retval;
 
-	new_msg = malloc(sizeof(struct hotplug_msg));
-	if (new_msg == NULL)
-		dbg("error malloc");
-	return new_msg;
-}
+	/* set signal handlers */
+	memset(&act, 0x00, sizeof(act));
+	act.sa_handler = (void (*)(int)) udev_event_sig_handler;
+	sigemptyset (&act.sa_mask);
+	act.sa_flags = 0;
+	sigaction(SIGALRM, &act, NULL);
 
-static void run_queue_delete(struct hotplug_msg *msg)
-{
-	list_del(&msg->list);
-	free(msg);
-	exec_queue_manager();
+	/* reset to default */
+	act.sa_handler = SIG_DFL;
+	sigaction(SIGINT, &act, NULL);
+	sigaction(SIGTERM, &act, NULL);
+	sigaction(SIGCHLD, &act, NULL);
+	sigaction(SIGHUP, &act, NULL);
+
+	/* trigger timeout to prevent hanging processes */
+	alarm(UDEV_ALARM_TIMEOUT);
+
+	/* reconstruct event environment from message */
+	for (i = 0; msg->envp[i]; i++)
+		putenv(msg->envp[i]);
+
+	udev = udev_device_init(NULL);
+	if (udev == NULL)
+		return -1;
+	strlcpy(udev->action, msg->action, sizeof(udev->action));
+	sysfs_device_set_values(udev->dev, msg->devpath, msg->subsystem, msg->driver);
+	udev->devpath_old = msg->devpath_old;
+	udev->devt = msg->devt;
+
+	retval = udev_device_event(&rules, udev);
+
+	/* run programs collected by RUN-key*/
+	if (retval == 0 && !udev->ignore_device && udev_run)
+		retval = udev_rules_run(udev);
+
+	udev_device_cleanup(udev);
+	return retval;
 }
 
-/* orders the message in the queue by sequence number */
-static void msg_queue_insert(struct hotplug_msg *msg)
+enum event_state {
+	EVENT_QUEUED,
+	EVENT_FINISHED,
+	EVENT_FAILED,
+};
+
+static void export_event_state(struct udevd_uevent_msg *msg, enum event_state state)
 {
-	struct hotplug_msg *loop_msg;
+	char filename[PATH_SIZE];
+	char filename_failed[PATH_SIZE];
+	size_t start;
+	struct udevd_uevent_msg *loop_msg;
+	int fd;
 
-	/* sort message by sequence number into list*/
-	list_for_each_entry(loop_msg, &msg_list, list)
-		if (loop_msg->seqnum > msg->seqnum)
-			break;
-	list_add_tail(&msg->list, &loop_msg->list);
-	dbg("queued message seq %d", msg->seqnum);
+	/* location of queue file */
+	strlcpy(filename, udev_root, sizeof(filename));
+	strlcat(filename, "/", sizeof(filename));
+	start = strlcat(filename, EVENT_QUEUE_DIR"/", sizeof(filename));
+	strlcat(filename, msg->devpath, sizeof(filename));
+	path_encode(&filename[start], sizeof(filename) - start);
 
-	/* store timestamp of queuing */
-	msg->queue_time = time(NULL);
+	/* location of failed file */
+	strlcpy(filename_failed, udev_root, sizeof(filename_failed));
+	strlcat(filename_failed, "/", sizeof(filename_failed));
+	start = strlcat(filename_failed, EVENT_FAILED_DIR"/", sizeof(filename_failed));
+	strlcat(filename_failed, msg->devpath, sizeof(filename_failed));
+	path_encode(&filename_failed[start], sizeof(filename) - start);
+
+	switch (state) {
+	case EVENT_QUEUED:
+		unlink(filename_failed);
+		delete_path(filename_failed);
+
+		create_path(filename);
+		fd = open(filename, O_WRONLY|O_TRUNC|O_CREAT, 0644);
+		if (fd > 0)
+			close(fd);
+		return;
+	case EVENT_FINISHED:
+	case EVENT_FAILED:
+		if (msg->devpath_old != NULL) {
+			/* "move" event - rename failed file to current name, do not delete failed */
+			char filename_failed_old[PATH_SIZE];
+
+			strlcpy(filename_failed_old, udev_root, sizeof(filename_failed_old));
+			strlcat(filename_failed_old, "/", sizeof(filename_failed_old));
+			start = strlcat(filename_failed_old, EVENT_FAILED_DIR"/", sizeof(filename_failed_old));
+			strlcat(filename_failed_old, msg->devpath_old, sizeof(filename_failed_old));
+			path_encode(&filename_failed_old[start], sizeof(filename) - start);
+
+			if (rename(filename_failed_old, filename_failed) == 0)
+				info("renamed devpath, moved failed state of '%s' to %s'",
+				     msg->devpath_old, msg->devpath);
+		} else {
+			unlink(filename_failed);
+			delete_path(filename_failed);
+		}
+
+		/* skip if events for the same path are still pending */
+		list_for_each_entry(loop_msg, &running_list, node)
+			if (loop_msg->devpath && strcmp(loop_msg->devpath, msg->devpath) == 0)
+				return;
+
+		list_for_each_entry(loop_msg, &exec_list, node)
+			if (loop_msg->devpath && strcmp(loop_msg->devpath, msg->devpath) == 0)
+				return;
 
-	/* run msg queue manager */
-	msg_queue_manager();
+		/* move failed event to the failed directory */
+		if (state == EVENT_FAILED) {
+			create_path(filename_failed);
+			rename(filename, filename_failed);
+		} else {
+			unlink(filename);
+		}
+
+		/* clean up possibly empty queue directory */
+		delete_path(filename);
 
-	return ;
+		return;
+	}
 }
 
-/* forks event and removes event from run queue when finished */
-static void udev_run(struct hotplug_msg *msg)
+static void msg_queue_delete(struct udevd_uevent_msg *msg)
 {
-	pid_t pid;
-	char action[ACTION_SIZE];
-	char devpath[DEVPATH_SIZE];
-	char *env[] = { action, devpath, NULL };
+	list_del(&msg->node);
 
-	snprintf(action, sizeof(action), "ACTION=%s", msg->action);
-	snprintf(devpath, sizeof(devpath), "DEVPATH=%s", msg->devpath);
+	/* mark as failed, if "add" event returns non-zero */
+	if (msg->exitstatus && strcmp(msg->action, "add") == 0)
+		export_event_state(msg, EVENT_FAILED);
+	else
+		export_event_state(msg, EVENT_FINISHED);
+
+	free(msg);
+}
+
+static void udev_event_run(struct udevd_uevent_msg *msg)
+{
+	pid_t pid;
+	int retval;
 
 	pid = fork();
 	switch (pid) {
 	case 0:
 		/* child */
-		execle(UDEV_BIN, "udev", msg->subsystem, NULL, env);
-		dbg("exec of child failed");
-		exit(1);
-		break;
+		close(uevent_netlink_sock);
+		close(udevd_sock);
+		if (inotify_fd >= 0)
+			close(inotify_fd);
+		close(signal_pipe[READ_END]);
+		close(signal_pipe[WRITE_END]);
+		logging_close();
+
+		logging_init("udevd-event");
+		setpriority(PRIO_PROCESS, 0, UDEV_PRIORITY);
+
+		retval = udev_event_process(msg);
+		info("seq %llu finished with %i", msg->seqnum, retval);
+
+		logging_close();
+		if (retval)
+			exit(1);
+		exit(0);
 	case -1:
-		dbg("fork of child failed");
-		run_queue_delete(msg);
+		err("fork of child failed: %s", strerror(errno));
+		msg_queue_delete(msg);
 		break;
 	default:
 		/* get SIGCHLD in main loop */
-		dbg("==> exec seq %d [%d] working at '%s'", msg->seqnum, pid, msg->devpath);
+		info("seq %llu forked, pid [%d], '%s' '%s', %ld seconds old",
+		     msg->seqnum, pid,  msg->action, msg->subsystem, time(NULL) - msg->queue_time);
 		msg->pid = pid;
 	}
 }
 
-/* returns already running task with devpath */
-static struct hotplug_msg *running_with_devpath(struct hotplug_msg *msg)
+static void msg_queue_insert(struct udevd_uevent_msg *msg)
 {
-	struct hotplug_msg *loop_msg;
-	list_for_each_entry(loop_msg, &running_list, list)
-		if (strncmp(loop_msg->devpath, msg->devpath, sizeof(loop_msg->devpath)) == 0)
-			return loop_msg;
-	return NULL;
+	char filename[PATH_SIZE];
+	int fd;
+
+	msg->queue_time = time(NULL);
+
+	strlcpy(filename, udev_root, sizeof(filename));
+	strlcat(filename, "/" EVENT_SEQNUM, sizeof(filename));
+	fd = open(filename, O_WRONLY|O_TRUNC|O_CREAT, 0644);
+	if (fd >= 0) {
+		char str[32];
+		int len;
+
+		len = sprintf(str, "%llu\n", msg->seqnum);
+		write(fd, str, len);
+		close(fd);
+	}
+
+	export_event_state(msg, EVENT_QUEUED);
+	info("seq %llu forked, '%s' '%s'", msg->seqnum, msg->action, msg->subsystem);
+
+	/* run one event after the other in debug mode */
+	if (debug_trace) {
+		list_add_tail(&msg->node, &running_list);
+		udev_event_run(msg);
+		waitpid(msg->pid, NULL, 0);
+		msg_queue_delete(msg);
+		return;
+	}
+
+	/* run all events with a timeout set immediately */
+	if (msg->timeout != 0) {
+		list_add_tail(&msg->node, &running_list);
+		udev_event_run(msg);
+		return;
+	}
+
+	list_add_tail(&msg->node, &exec_list);
+	run_exec_q = 1;
 }
 
-/* exec queue management routine executes the events and delays events for the same devpath */
-static void exec_queue_manager()
+static int mem_size_mb(void)
 {
-	struct hotplug_msg *loop_msg;
-	struct hotplug_msg *tmp_msg;
-	struct hotplug_msg *msg;
-
-	list_for_each_entry_safe(loop_msg, tmp_msg, &exec_list, list) {
-		msg = running_with_devpath(loop_msg);
-		if (!msg) {
-			/* move event to run list */
-			list_move_tail(&loop_msg->list, &running_list);
-			udev_run(loop_msg);
-			dbg("moved seq %d to running list", loop_msg->seqnum);
-		} else {
-			dbg("delay seq %d, cause seq %d already working on '%s'",
-				loop_msg->seqnum, msg->seqnum, msg->devpath);
+	FILE* f;
+	char buf[4096];
+	long int memsize = -1;
+
+	f = fopen("/proc/meminfo", "r");
+	if (f == NULL)
+		return -1;
+
+	while (fgets(buf, sizeof(buf), f) != NULL) {
+		long int value;
+
+		if (sscanf(buf, "MemTotal: %ld kB", &value) == 1) {
+			memsize = value / 1024;
+			break;
 		}
 	}
+
+	fclose(f);
+	return memsize;
 }
 
-static void msg_move_exec(struct hotplug_msg *msg)
+static int cpu_count(void)
 {
-	list_move_tail(&msg->list, &exec_list);
-	exec_queue_manager();
-	expected_seqnum = msg->seqnum+1;
-	dbg("moved seq %d to exec, next expected is %d",
-		msg->seqnum, expected_seqnum);
+	FILE* f;
+	char buf[4096];
+	int count = 0;
+
+	f = fopen("/proc/stat", "r");
+	if (f == NULL)
+		return -1;
+
+	while (fgets(buf, sizeof(buf), f) != NULL) {
+		if (strncmp(buf, "cpu", 3) == 0 && isdigit(buf[3]))
+			count++;
+	}
+
+	fclose(f);
+	if (count == 0)
+		return -1;
+	return count;
 }
 
-/* msg queue management routine handles the timeouts and dispatches the events */
-static void msg_queue_manager()
+static int running_processes(void)
 {
-	struct hotplug_msg *loop_msg;
-	struct hotplug_msg *tmp_msg;
-	time_t msg_age = 0;
-
-	dbg("msg queue manager, next expected is %d", expected_seqnum);
-recheck:
-	list_for_each_entry_safe(loop_msg, tmp_msg, &msg_list, list) {
-		/* move event with expected sequence to the exec list */
-		if (loop_msg->seqnum == expected_seqnum) {
-			msg_move_exec(loop_msg);
-			continue;
+	FILE* f;
+	char buf[4096];
+	int running = -1;
+
+	f = fopen("/proc/stat", "r");
+	if (f == NULL)
+		return -1;
+
+	while (fgets(buf, sizeof(buf), f) != NULL) {
+		int value;
+
+		if (sscanf(buf, "procs_running %u", &value) == 1) {
+			running = value;
+			break;
 		}
+	}
 
-		/* move event with expired timeout to the exec list */
-		msg_age = time(NULL) - loop_msg->queue_time;
-		if (msg_age > EVENT_TIMEOUT_SEC-1) {
-			msg_move_exec(loop_msg);
-			goto recheck;
-		} else {
+	fclose(f);
+	return running;
+}
+
+/* return the number of process es in our session, count only until limit */
+static int running_processes_in_session(pid_t session, int limit)
+{
+	DIR *dir;
+	struct dirent *dent;
+	int running = 0;
+
+	dir = opendir("/proc");
+	if (!dir)
+		return -1;
+
+	/* read process info from /proc */
+	for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
+		int f;
+		char procdir[64];
+		char line[256];
+		const char *pos;
+		char state;
+		pid_t ppid, pgrp, sess;
+		int len;
+
+		if (!isdigit(dent->d_name[0]))
+			continue;
+
+		snprintf(procdir, sizeof(procdir), "/proc/%s/stat", dent->d_name);
+		procdir[sizeof(procdir)-1] = '\0';
+
+		f = open(procdir, O_RDONLY);
+		if (f == -1)
+			continue;
+
+		len = read(f, line, sizeof(line)-1);
+		close(f);
+
+		if (len <= 0)
+			continue;
+		else
+			line[len] = '\0';
+
+		/* skip ugly program name */
+		pos = strrchr(line, ')') + 2;
+		if (pos == NULL)
+			continue;
+
+		if (sscanf(pos, "%c %d %d %d ", &state, &ppid, &pgrp, &sess) != 4)
+			continue;
+
+		/* count only processes in our session */
+		if (sess != session)
+			continue;
+
+		/* count only running, no sleeping processes */
+		if (state != 'R')
+			continue;
+
+		running++;
+		if (limit > 0 && running >= limit)
+			break;
+	}
+	closedir(dir);
+
+	return running;
+}
+
+static int compare_devpath(const char *running, const char *waiting)
+{
+	int i;
+
+	for (i = 0; i < PATH_SIZE; i++) {
+		/* identical device event found */
+		if (running[i] == '\0' && waiting[i] == '\0')
+			return 1;
+
+		/* parent device event found */
+		if (running[i] == '\0' && waiting[i] == '/')
+			return 2;
+
+		/* child device event found */
+		if (running[i] == '/' && waiting[i] == '\0')
+			return 3;
+
+		/* no matching event */
+		if (running[i] != waiting[i])
+			break;
+	}
+
+	return 0;
+}
+
+/* lookup event for identical, parent, child, or physical device */
+static int devpath_busy(struct udevd_uevent_msg *msg, int limit)
+{
+	struct udevd_uevent_msg *loop_msg;
+	int childs_count = 0;
+
+	/* check exec-queue which may still contain delayed events we depend on */
+	list_for_each_entry(loop_msg, &exec_list, node) {
+		/* skip ourself and all later events */
+		if (loop_msg->seqnum >= msg->seqnum)
 			break;
+
+		/* check our old name */
+		if (msg->devpath_old != NULL)
+			if (strcmp(loop_msg->devpath , msg->devpath_old) == 0)
+				return 2;
+
+		/* check identical, parent, or child device event */
+		if (compare_devpath(loop_msg->devpath, msg->devpath) != 0) {
+			dbg("%llu, device event still pending %llu (%s)",
+			    msg->seqnum, loop_msg->seqnum, loop_msg->devpath);
+			return 3;
 		}
+
+		/* check physical device event (special case of parent) */
+		if (msg->physdevpath && msg->action && strcmp(msg->action, "add") == 0)
+			if (compare_devpath(loop_msg->devpath, msg->physdevpath) != 0) {
+				dbg("%llu, physical device event still pending %llu (%s)",
+				    msg->seqnum, loop_msg->seqnum, loop_msg->devpath);
+				return 4;
+			}
 	}
 
-	msg_dump_queue();
+	/* check run queue for still running events */
+	list_for_each_entry(loop_msg, &running_list, node) {
+		if (limit && childs_count++ > limit) {
+			dbg("%llu, maximum number (%i) of childs reached", msg->seqnum, childs_count);
+			return 1;
+		}
 
-	if (list_empty(&msg_list) == 0) {
-		/* set timeout for remaining queued events */
-		struct itimerval itv = {{0, 0}, {EVENT_TIMEOUT_SEC - msg_age, 0}};
-		dbg("next event expires in %li seconds",
-		    EVENT_TIMEOUT_SEC - msg_age);
-		setitimer(ITIMER_REAL, &itv, 0);
+		/* check our old name */
+		if (msg->devpath_old != NULL)
+			if (strcmp(loop_msg->devpath , msg->devpath_old) == 0)
+				return 2;
+
+		/* check identical, parent, or child device event */
+		if (compare_devpath(loop_msg->devpath, msg->devpath) != 0) {
+			dbg("%llu, device event still running %llu (%s)",
+			    msg->seqnum, loop_msg->seqnum, loop_msg->devpath);
+			return 3;
+		}
+
+		/* check physical device event (special case of parent) */
+		if (msg->physdevpath && msg->action && strcmp(msg->action, "add") == 0)
+			if (compare_devpath(loop_msg->devpath, msg->physdevpath) != 0) {
+				dbg("%llu, physical device event still running %llu (%s)",
+				    msg->seqnum, loop_msg->seqnum, loop_msg->devpath);
+				return 4;
+			}
 	}
+	return 0;
 }
 
-/* receive the msg, do some basic sanity checks, and queue it */
-static void handle_msg(int sock)
+/* serializes events for the identical and parent and child devices */
+static void msg_queue_manager(void)
 {
-	struct hotplug_msg *msg;
-	int retval;
+	struct udevd_uevent_msg *loop_msg;
+	struct udevd_uevent_msg *tmp_msg;
+	int running;
+
+	if (list_empty(&exec_list))
+		return;
+
+	running = running_processes();
+	dbg("%d processes runnning on system", running);
+	if (running < 0)
+		running = max_childs_running;
+
+	list_for_each_entry_safe(loop_msg, tmp_msg, &exec_list, node) {
+		/* check running processes in our session and possibly throttle */
+		if (running >= max_childs_running) {
+			running = running_processes_in_session(sid, max_childs_running+10);
+			dbg("at least %d processes running in session", running);
+			if (running >= max_childs_running) {
+				dbg("delay seq %llu, too many processes already running", loop_msg->seqnum);
+				return;
+			}
+		}
+
+		/* serialize and wait for parent or child events */
+		if (devpath_busy(loop_msg, max_childs) != 0) {
+			dbg("delay seq %llu (%s)", loop_msg->seqnum, loop_msg->devpath);
+			continue;
+		}
+
+		/* move event to run list */
+		list_move_tail(&loop_msg->node, &running_list);
+		udev_event_run(loop_msg);
+		running++;
+		dbg("moved seq %llu to running list", loop_msg->seqnum);
+	}
+}
+
+static struct udevd_uevent_msg *get_msg_from_envbuf(const char *buf, int buf_size)
+{
+	int bufpos;
+	int i;
+	struct udevd_uevent_msg *msg;
+	char *physdevdriver_key = NULL;
+	int maj = 0;
+	int min = 0;
+
+	msg = malloc(sizeof(struct udevd_uevent_msg) + buf_size);
+	if (msg == NULL)
+		return NULL;
+	memset(msg, 0x00, sizeof(struct udevd_uevent_msg) + buf_size);
+
+	/* copy environment buffer and reconstruct envp */
+	memcpy(msg->envbuf, buf, buf_size);
+	bufpos = 0;
+	for (i = 0; (bufpos < buf_size) && (i < UEVENT_NUM_ENVP-2); i++) {
+		int keylen;
+		char *key;
+
+		key = &msg->envbuf[bufpos];
+		keylen = strlen(key);
+		msg->envp[i] = key;
+		bufpos += keylen + 1;
+		dbg("add '%s' to msg.envp[%i]", msg->envp[i], i);
+
+		/* remember some keys for further processing */
+		if (strncmp(key, "ACTION=", 7) == 0)
+			msg->action = &key[7];
+		else if (strncmp(key, "DEVPATH=", 8) == 0)
+			msg->devpath = &key[8];
+		else if (strncmp(key, "SUBSYSTEM=", 10) == 0)
+			msg->subsystem = &key[10];
+		else if (strncmp(key, "DRIVER=", 7) == 0)
+			msg->driver = &key[7];
+		else if (strncmp(key, "SEQNUM=", 7) == 0)
+			msg->seqnum = strtoull(&key[7], NULL, 10);
+		else if (strncmp(key, "DEVPATH_OLD=", 12) == 0)
+			msg->devpath_old = &key[12];
+		else if (strncmp(key, "PHYSDEVPATH=", 12) == 0)
+			msg->physdevpath = &key[12];
+		else if (strncmp(key, "PHYSDEVDRIVER=", 14) == 0)
+			physdevdriver_key = key;
+		else if (strncmp(key, "MAJOR=", 6) == 0)
+			maj = strtoull(&key[6], NULL, 10);
+		else if (strncmp(key, "MINOR=", 6) == 0)
+			min = strtoull(&key[6], NULL, 10);
+		else if (strncmp(key, "TIMEOUT=", 8) == 0)
+			msg->timeout = strtoull(&key[8], NULL, 10);
+	}
+	msg->devt = makedev(maj, min);
+	msg->envp[i++] = "UDEVD_EVENT=1";
+
+	if (msg->driver == NULL && msg->physdevpath == NULL && physdevdriver_key != NULL) {
+		/* for older kernels DRIVER is empty for a bus device, export PHYSDEVDRIVER as DRIVER */
+		msg->envp[i++] = &physdevdriver_key[7];
+		msg->driver = &physdevdriver_key[14];
+	}
+
+	msg->envp[i] = NULL;
+
+	if (msg->devpath == NULL || msg->action == NULL) {
+		info("DEVPATH or ACTION missing, ignore message");
+		free(msg);
+		return NULL;
+	}
+	return msg;
+}
+
+/* receive the udevd message from userspace */
+static void get_ctrl_msg(void)
+{
+	struct udevd_ctrl_msg ctrl_msg;
+	ssize_t size;
 	struct msghdr smsg;
 	struct cmsghdr *cmsg;
 	struct iovec iov;
 	struct ucred *cred;
 	char cred_msg[CMSG_SPACE(sizeof(struct ucred))];
+	int *intval;
+	char *pos;
 
-	msg = msg_create();
-	if (msg == NULL) {
-		dbg("unable to store message");
-		return;
-	}
-
-	iov.iov_base = msg;
-	iov.iov_len = sizeof(struct hotplug_msg);
+	memset(&ctrl_msg, 0x00, sizeof(struct udevd_ctrl_msg));
+	iov.iov_base = &ctrl_msg;
+	iov.iov_len = sizeof(struct udevd_ctrl_msg);
 
 	memset(&smsg, 0x00, sizeof(struct msghdr));
 	smsg.msg_iov = &iov;
@@ -248,147 +671,616 @@ static void handle_msg(int sock)
 	smsg.msg_control = cred_msg;
 	smsg.msg_controllen = sizeof(cred_msg);
 
-	retval = recvmsg(sock, &smsg, 0);
-	if (retval <  0) {
+	size = recvmsg(udevd_sock, &smsg, 0);
+	if (size <  0) {
 		if (errno != EINTR)
-			dbg("unable to receive message");
+			err("unable to receive user udevd message: %s", strerror(errno));
 		return;
 	}
 	cmsg = CMSG_FIRSTHDR(&smsg);
 	cred = (struct ucred *) CMSG_DATA(cmsg);
 
 	if (cmsg == NULL || cmsg->cmsg_type != SCM_CREDENTIALS) {
-		dbg("no sender credentials received, message ignored");
-		goto skip;
+		err("no sender credentials received, message ignored");
+		return;
 	}
 
 	if (cred->uid != 0) {
-		dbg("sender uid=%i, message ignored", cred->uid);
-		goto skip;
+		err("sender uid=%i, message ignored", cred->uid);
+		return;
 	}
 
-	if (strncmp(msg->magic, UDEV_MAGIC, sizeof(UDEV_MAGIC)) != 0 ) {
-		dbg("message magic '%s' doesn't match, ignore it", msg->magic);
-		goto skip;
+	if (strncmp(ctrl_msg.magic, UDEVD_CTRL_MAGIC, sizeof(UDEVD_CTRL_MAGIC)) != 0 ) {
+		err("message magic '%s' doesn't match, ignore it", ctrl_msg.magic);
+		return;
 	}
 
-	/* if no seqnum is given, we move straight to exec queue */
-	if (msg->seqnum == -1) {
-		list_add(&msg->list, &exec_list);
-		exec_queue_manager();
-	} else {
-		msg_queue_insert(msg);
+	switch (ctrl_msg.type) {
+	case UDEVD_CTRL_ENV:
+		pos = strchr(ctrl_msg.buf, '=');
+		if (pos == NULL) {
+			err("wrong key format '%s'", ctrl_msg.buf);
+			break;
+		}
+		pos[0] = '\0';
+		if (pos[1] == '\0') {
+			info("udevd message (ENV) received, unset '%s'", ctrl_msg.buf);
+			unsetenv(ctrl_msg.buf);
+		} else {
+			info("udevd message (ENV) received, set '%s=%s'", ctrl_msg.buf, &pos[1]);
+			setenv(ctrl_msg.buf, &pos[1], 1);
+		}
+		break;
+	case UDEVD_CTRL_STOP_EXEC_QUEUE:
+		info("udevd message (STOP_EXEC_QUEUE) received");
+		stop_exec_q = 1;
+		break;
+	case UDEVD_CTRL_START_EXEC_QUEUE:
+		info("udevd message (START_EXEC_QUEUE) received");
+		stop_exec_q = 0;
+		msg_queue_manager();
+		break;
+	case UDEVD_CTRL_SET_LOG_LEVEL:
+		intval = (int *) ctrl_msg.buf;
+		info("udevd message (SET_LOG_PRIORITY) received, udev_log_priority=%i", *intval);
+		udev_log_priority = *intval;
+		sprintf(udev_log, "UDEV_LOG=%i", udev_log_priority);
+		putenv(udev_log);
+		break;
+	case UDEVD_CTRL_SET_MAX_CHILDS:
+		intval = (int *) ctrl_msg.buf;
+		info("udevd message (UDEVD_SET_MAX_CHILDS) received, max_childs=%i", *intval);
+		max_childs = *intval;
+		break;
+	case UDEVD_CTRL_SET_MAX_CHILDS_RUNNING:
+		intval = (int *) ctrl_msg.buf;
+		info("udevd message (UDEVD_SET_MAX_CHILDS_RUNNING) received, max_childs=%i", *intval);
+		max_childs_running = *intval;
+		break;
+	case UDEVD_CTRL_RELOAD_RULES:
+		info("udevd message (RELOAD_RULES) received");
+		reload_config = 1;
+		break;
+	default:
+		err("unknown control message type");
 	}
-	return;
+}
 
-skip:
-	free(msg);
-	return;
+/* receive the kernel user event message and do some sanity checks */
+static struct udevd_uevent_msg *get_netlink_msg(void)
+{
+	struct udevd_uevent_msg *msg;
+	int bufpos;
+	ssize_t size;
+	static char buffer[UEVENT_BUFFER_SIZE+512];
+	char *pos;
+
+	size = recv(uevent_netlink_sock, &buffer, sizeof(buffer), 0);
+	if (size <  0) {
+		if (errno != EINTR)
+			err("unable to receive kernel netlink message: %s", strerror(errno));
+		return NULL;
+	}
+
+	if ((size_t)size > sizeof(buffer)-1)
+		size = sizeof(buffer)-1;
+	buffer[size] = '\0';
+	dbg("uevent_size=%zi", size);
+
+	/* start of event payload */
+	bufpos = strlen(buffer)+1;
+	msg = get_msg_from_envbuf(&buffer[bufpos], size-bufpos);
+	if (msg == NULL)
+		return NULL;
+
+	/* validate message */
+	pos = strchr(buffer, '@');
+	if (pos == NULL) {
+		err("invalid uevent '%s'", buffer);
+		free(msg);
+		return NULL;
+	}
+	pos[0] = '\0';
+
+	if (msg->action == NULL) {
+		info("no ACTION in payload found, skip event '%s'", buffer);
+		free(msg);
+		return NULL;
+	}
+
+	if (strcmp(msg->action, buffer) != 0) {
+		err("ACTION in payload does not match uevent, skip event '%s'", buffer);
+		free(msg);
+		return NULL;
+	}
+
+	return msg;
 }
 
-static void sig_handler(int signum)
+static void asmlinkage sig_handler(int signum)
 {
 	switch (signum) {
 		case SIGINT:
 		case SIGTERM:
-			exit(20 + signum);
-			break;
-		case SIGALRM:
-			msg_q_timeout = 1;
+			udev_exit = 1;
 			break;
 		case SIGCHLD:
-			children_waiting = 1;
+			/* set flag, then write to pipe if needed */
+			sigchilds_waiting = 1;
+			break;
+		case SIGHUP:
+			reload_config = 1;
 			break;
-		default:
-			dbg("unhandled signal");
 	}
+
+	/* write to pipe, which will wakeup select() in our mainloop */
+	write(signal_pipe[WRITE_END], "", 1);
 }
 
-static void udev_done(int pid)
+static void udev_done(int pid, int exitstatus)
 {
 	/* find msg associated with pid and delete it */
-	struct hotplug_msg *msg;
+	struct udevd_uevent_msg *msg;
 
-	list_for_each_entry(msg, &running_list, list) {
+	list_for_each_entry(msg, &running_list, node) {
 		if (msg->pid == pid) {
-			dbg("<== exec seq %d came back", msg->seqnum);
-			run_queue_delete(msg);
+			info("seq %llu, pid [%d] exit with %i, %ld seconds old", msg->seqnum, msg->pid,
+			     exitstatus, time(NULL) - msg->queue_time);
+			msg->exitstatus = exitstatus;
+			msg_queue_delete(msg);
+
+			/* there may be events waiting with the same devpath */
+			run_exec_q = 1;
 			return;
 		}
 	}
 }
 
-int main(int argc, char *argv[])
+static void reap_sigchilds(void)
+{
+	pid_t pid;
+	int status;
+
+	while (1) {
+		pid = waitpid(-1, &status, WNOHANG);
+		if (pid <= 0)
+			break;
+		if (WIFEXITED(status))
+			status = WEXITSTATUS(status);
+		else if (WIFSIGNALED(status))
+			status = WTERMSIG(status) + 128;
+		else
+			status = 0;
+		udev_done(pid, status);
+	}
+}
+
+static int init_udevd_socket(void)
 {
-	int ssock;
 	struct sockaddr_un saddr;
 	socklen_t addrlen;
+	const int feature_on = 1;
+	int retval;
+
+	memset(&saddr, 0x00, sizeof(saddr));
+	saddr.sun_family = AF_LOCAL;
+	/* use abstract namespace for socket path */
+	strcpy(&saddr.sun_path[1], UDEVD_CTRL_SOCK_PATH);
+	addrlen = offsetof(struct sockaddr_un, sun_path) + strlen(saddr.sun_path+1) + 1;
+
+	udevd_sock = socket(AF_LOCAL, SOCK_DGRAM, 0);
+	if (udevd_sock == -1) {
+		err("error getting socket: %s", strerror(errno));
+		return -1;
+	}
+
+	/* the bind takes care of ensuring only one copy running */
+	retval = bind(udevd_sock, (struct sockaddr *) &saddr, addrlen);
+	if (retval < 0) {
+		err("bind failed: %s", strerror(errno));
+		close(udevd_sock);
+		udevd_sock = -1;
+		return -1;
+	}
+
+	/* enable receiving of the sender credentials */
+	setsockopt(udevd_sock, SOL_SOCKET, SO_PASSCRED, &feature_on, sizeof(feature_on));
+
+	return 0;
+}
+
+static int init_uevent_netlink_sock(void)
+{
+	struct sockaddr_nl snl;
+	const int buffersize = 16 * 1024 * 1024;
 	int retval;
-	const int on = 1;
+
+	memset(&snl, 0x00, sizeof(struct sockaddr_nl));
+	snl.nl_family = AF_NETLINK;
+	snl.nl_pid = getpid();
+	snl.nl_groups = 1;
+
+	uevent_netlink_sock = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_KOBJECT_UEVENT);
+	if (uevent_netlink_sock == -1) {
+		err("error getting socket: %s", strerror(errno));
+		return -1;
+	}
+
+	/* set receive buffersize */
+	setsockopt(uevent_netlink_sock, SOL_SOCKET, SO_RCVBUFFORCE, &buffersize, sizeof(buffersize));
+
+	retval = bind(uevent_netlink_sock, (struct sockaddr *) &snl, sizeof(struct sockaddr_nl));
+	if (retval < 0) {
+		err("bind failed: %s", strerror(errno));
+		close(uevent_netlink_sock);
+		uevent_netlink_sock = -1;
+		return -1;
+	}
+	return 0;
+}
+
+static void export_initial_seqnum(void)
+{
+	char filename[PATH_SIZE];
+	int fd;
+	char seqnum[32];
+	ssize_t len = 0;
+
+	strlcpy(filename, sysfs_path, sizeof(filename));
+	strlcat(filename, "/kernel/uevent_seqnum", sizeof(filename));
+	fd = open(filename, O_RDONLY);
+	if (fd >= 0) {
+		len = read(fd, seqnum, sizeof(seqnum)-1);
+		close(fd);
+	}
+	if (len <= 0) {
+		strcpy(seqnum, "0\n");
+		len = 3;
+	}
+	strlcpy(filename, udev_root, sizeof(filename));
+	strlcat(filename, "/" EVENT_SEQNUM, sizeof(filename));
+	create_path(filename);
+	fd = open(filename, O_WRONLY|O_TRUNC|O_CREAT, 0644);
+	if (fd >= 0) {
+		write(fd, seqnum, len);
+		close(fd);
+	}
+}
+
+int main(int argc, char *argv[], char *envp[])
+{
+	int retval;
+	int fd;
 	struct sigaction act;
+	fd_set readfds;
+	const char *value;
+	int daemonize = 0;
+	int option;
+	static const struct option options[] = {
+		{ "daemon", 0, NULL, 'd' },
+		{ "debug-trace", 0, NULL, 't' },
+		{ "verbose", 0, NULL, 'v' },
+		{ "help", 0, NULL, 'h' },
+		{ "version", 0, NULL, 'V' },
+		{}
+	};
+	int rc = 1;
+	int maxfd;
 
-	init_logging("udevd");
+	logging_init("udevd");
+	udev_config_init();
+	selinux_init();
 	dbg("version %s", UDEV_VERSION);
 
+	while (1) {
+		option = getopt_long(argc, argv, "dtvhV", options, NULL);
+		if (option == -1)
+			break;
+
+		switch (option) {
+		case 'd':
+			daemonize = 1;
+			break;
+		case 't':
+			debug_trace = 1;
+			break;
+		case 'v':
+			verbose = 1;
+			if (udev_log_priority < LOG_INFO)
+				udev_log_priority = LOG_INFO;
+			break;
+		case 'h':
+			printf("Usage: udevd [--help] [--daemon] [--debug-trace] [--verbose] [--version]\n");
+			goto exit;
+		case 'V':
+			printf("%s\n", UDEV_VERSION);
+			goto exit;
+		default:
+			goto exit;
+		}
+	}
+
 	if (getuid() != 0) {
-		dbg("need to be root, exit");
-		exit(1);
+		fprintf(stderr, "root privileges required\n");
+		err("root privileges required");
+		goto exit;
 	}
 
-	/* set signal handler */
-	act.sa_handler = sig_handler;
-	sigemptyset (&act.sa_mask);
+	/* make sure std{in,out,err} fd's are in a sane state */
+	fd = open("/dev/null", O_RDWR);
+	if (fd < 0) {
+		fprintf(stderr, "cannot open /dev/null\n");
+		err("cannot open /dev/null");
+	}
+	if (fd > STDIN_FILENO)
+		dup2(fd, STDIN_FILENO);
+	if (write(STDOUT_FILENO, 0, 0) < 0)
+		dup2(fd, STDOUT_FILENO);
+	if (write(STDERR_FILENO, 0, 0) < 0)
+		dup2(fd, STDERR_FILENO);
+
+	/* init sockets to receive events */
+	if (init_udevd_socket() < 0) {
+		if (errno == EADDRINUSE) {
+			fprintf(stderr, "another udev daemon already running\n");
+			err("another udev daemon already running");
+			rc = 1;
+		} else {
+			fprintf(stderr, "error initializing udevd socket\n");
+			err("error initializing udevd socket");
+			rc = 2;
+		}
+		goto exit;
+	}
+
+	if (init_uevent_netlink_sock() < 0) {
+		fprintf(stderr, "error initializing netlink socket\n");
+		err("error initializing netlink socket");
+		rc = 3;
+		goto exit;
+	}
+
+	/* setup signal handler pipe */
+	retval = pipe(signal_pipe);
+	if (retval < 0) {
+		err("error getting pipes: %s", strerror(errno));
+		goto exit;
+	}
+
+	retval = fcntl(signal_pipe[READ_END], F_GETFL, 0);
+	if (retval < 0) {
+		err("error fcntl on read pipe: %s", strerror(errno));
+		goto exit;
+	}
+	retval = fcntl(signal_pipe[READ_END], F_SETFL, retval | O_NONBLOCK);
+	if (retval < 0) {
+		err("error fcntl on read pipe: %s", strerror(errno));
+		goto exit;
+	}
+
+	retval = fcntl(signal_pipe[WRITE_END], F_GETFL, 0);
+	if (retval < 0) {
+		err("error fcntl on write pipe: %s", strerror(errno));
+		goto exit;
+	}
+	retval = fcntl(signal_pipe[WRITE_END], F_SETFL, retval | O_NONBLOCK);
+	if (retval < 0) {
+		err("error fcntl on write pipe: %s", strerror(errno));
+		goto exit;
+	}
+
+	/* parse the rules and keep them in memory */
+	sysfs_init();
+	udev_rules_init(&rules, 1);
+
+	export_initial_seqnum();
+
+	if (daemonize) {
+		pid_t pid;
+
+		pid = fork();
+		switch (pid) {
+		case 0:
+			dbg("daemonized fork running");
+			break;
+		case -1:
+			err("fork of daemon failed: %s", strerror(errno));
+			rc = 4;
+			goto exit;
+		default:
+			dbg("child [%u] running, parent exits", pid);
+			rc = 0;
+			goto exit;
+		}
+	}
+
+	/* redirect std{out,err} fd's */
+	if (!verbose)
+		dup2(fd, STDOUT_FILENO);
+	dup2(fd, STDERR_FILENO);
+	if (fd > STDERR_FILENO)
+		close(fd);
+
+	/* set scheduling priority for the daemon */
+	setpriority(PRIO_PROCESS, 0, UDEVD_PRIORITY);
+
+	chdir("/");
+	umask(022);
+
+	/* become session leader */
+	sid = setsid();
+	dbg("our session is %d", sid);
+
+	/* OOM_DISABLE == -17 */
+	fd = open("/proc/self/oom_adj", O_RDWR);
+	if (fd < 0)
+		err("error disabling OOM: %s", strerror(errno));
+	else {
+		write(fd, "-17", 3);
+		close(fd);
+	}
+
+	/* set signal handlers */
+	memset(&act, 0x00, sizeof(struct sigaction));
+	act.sa_handler = (void (*)(int)) sig_handler;
+	sigemptyset(&act.sa_mask);
 	act.sa_flags = SA_RESTART;
 	sigaction(SIGINT, &act, NULL);
 	sigaction(SIGTERM, &act, NULL);
-
-	/* we want these two to interrupt system calls */
-	act.sa_flags = 0;
-	sigaction(SIGALRM, &act, NULL);
 	sigaction(SIGCHLD, &act, NULL);
+	sigaction(SIGHUP, &act, NULL);
 
-	memset(&saddr, 0x00, sizeof(saddr));
-	saddr.sun_family = AF_LOCAL;
-	/* use abstract namespace for socket path */
-	strcpy(&saddr.sun_path[1], UDEVD_SOCK_PATH);
-	addrlen = offsetof(struct sockaddr_un, sun_path) + strlen(saddr.sun_path+1) + 1;
+	/* watch rules directory */
+	inotify_fd = inotify_init();
+	if (inotify_fd >= 0) {
+		char filename[PATH_MAX];
 
-	ssock = socket(AF_LOCAL, SOCK_DGRAM, 0);
-	if (ssock == -1) {
-		dbg("error getting socket, exit");
-		exit(1);
+		inotify_add_watch(inotify_fd, udev_rules_dir, IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
+
+		/* watch dynamic rules directory */
+		strlcpy(filename, udev_root, sizeof(filename));
+		strlcat(filename, "/"RULES_DYN_DIR, sizeof(filename));
+		inotify_add_watch(inotify_fd, filename, IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
+	} else if (errno == ENOSYS)
+		err("the kernel does not support inotify, udevd can't monitor rules file changes");
+	else
+		err("inotify_init failed: %s", strerror(errno));
+
+	/* maximum limit of forked childs */
+	value = getenv("UDEVD_MAX_CHILDS");
+	if (value)
+		max_childs = strtoul(value, NULL, 10);
+	else {
+		int memsize = mem_size_mb();
+		if (memsize > 0)
+			max_childs = 128 + (memsize / 4);
+		else
+			max_childs = UDEVD_MAX_CHILDS;
 	}
+	info("initialize max_childs to %u", max_childs);
 
-	/* the bind takes care of ensuring only one copy running */
-	retval = bind(ssock, (struct sockaddr *) &saddr, addrlen);
-	if (retval < 0) {
-		dbg("bind failed, exit");
-		goto exit;
+	/* start to throttle forking if maximum number of _running_ childs is reached */
+	value = getenv("UDEVD_MAX_CHILDS_RUNNING");
+	if (value)
+		max_childs_running = strtoull(value, NULL, 10);
+	else {
+		int cpus = cpu_count();
+		if (cpus > 0)
+			max_childs_running = 8 + (8 * cpus);
+		else
+			max_childs_running = UDEVD_MAX_CHILDS_RUNNING;
 	}
+	info("initialize max_childs_running to %u", max_childs_running);
 
-	/* enable receiving of the sender credentials */
-	setsockopt(ssock, SOL_SOCKET, SO_PASSCRED, &on, sizeof(on));
+	/* clear environment for forked event processes */
+	clearenv();
 
-	while (1) {
-		handle_msg(ssock);
+	/* export log_priority , as called programs may want to follow that setting */
+	sprintf(udev_log, "UDEV_LOG=%i", udev_log_priority);
+	putenv(udev_log);
+	if (debug_trace)
+		putenv("DEBUG=1");
+
+	maxfd = udevd_sock;
+	maxfd = UDEV_MAX(maxfd, uevent_netlink_sock);
+	maxfd = UDEV_MAX(maxfd, signal_pipe[READ_END]);
+	maxfd = UDEV_MAX(maxfd, inotify_fd);
+
+	while (!udev_exit) {
+		struct udevd_uevent_msg *msg;
+		int fdcount;
 
-		while(msg_q_timeout) {
-			msg_q_timeout = 0;
-			msg_queue_manager();
+		FD_ZERO(&readfds);
+		FD_SET(signal_pipe[READ_END], &readfds);
+		FD_SET(udevd_sock, &readfds);
+		FD_SET(uevent_netlink_sock, &readfds);
+		if (inotify_fd >= 0)
+			FD_SET(inotify_fd, &readfds);
+
+		fdcount = select(maxfd+1, &readfds, NULL, NULL, NULL);
+		if (fdcount < 0) {
+			if (errno != EINTR)
+				err("error in select: %s", strerror(errno));
+			continue;
+		}
+
+		/* get control message */
+		if (FD_ISSET(udevd_sock, &readfds))
+			get_ctrl_msg();
+
+		/* get netlink message */
+		if (FD_ISSET(uevent_netlink_sock, &readfds)) {
+			msg = get_netlink_msg();
+			if (msg)
+				msg_queue_insert(msg);
 		}
 
-		while(children_waiting) {
-			children_waiting = 0;
-			/* reap all dead children */
-			while(1) {
-				int pid = waitpid(-1, 0, WNOHANG);
-				if ((pid == -1) || (pid == 0))
-					break;
-				udev_done(pid);
+		/* received a signal, clear our notification pipe */
+		if (FD_ISSET(signal_pipe[READ_END], &readfds)) {
+			char buf[256];
+
+			read(signal_pipe[READ_END], &buf, sizeof(buf));
+		}
+
+		/* rules directory inotify watch */
+		if ((inotify_fd >= 0) && FD_ISSET(inotify_fd, &readfds)) {
+			int nbytes;
+
+			/* discard all possible events, we can just reload the config */
+			if ((ioctl(inotify_fd, FIONREAD, &nbytes) == 0) && nbytes > 0) {
+				char *buf;
+
+				reload_config = 1;
+				buf = malloc(nbytes);
+				if (buf == NULL) {
+					err("error getting buffer for inotify, disable watching");
+					close(inotify_fd);
+					inotify_fd = -1;
+				}
+				read(inotify_fd, buf, nbytes);
+				free(buf);
 			}
 		}
+
+		/* rules changed, set by inotify or a HUP signal */
+		if (reload_config) {
+			reload_config = 0;
+			udev_rules_cleanup(&rules);
+			udev_rules_init(&rules, 1);
+		}
+
+		/* forked child has returned */
+		if (sigchilds_waiting) {
+			sigchilds_waiting = 0;
+			reap_sigchilds();
+		}
+
+		if (run_exec_q) {
+			run_exec_q = 0;
+			if (!stop_exec_q)
+				msg_queue_manager();
+		}
 	}
+	rc = 0;
+
 exit:
-	close(ssock);
-	exit(1);
+	udev_rules_cleanup(&rules);
+	sysfs_cleanup();
+	selinux_exit();
+
+	if (signal_pipe[READ_END] >= 0)
+		close(signal_pipe[READ_END]);
+	if (signal_pipe[WRITE_END] >= 0)
+		close(signal_pipe[WRITE_END]);
+
+	if (udevd_sock >= 0)
+		close(udevd_sock);
+	if (inotify_fd >= 0)
+		close(inotify_fd);
+	if (uevent_netlink_sock >= 0)
+		close(uevent_netlink_sock);
+
+	logging_close();
+
+	return rc;
 }