X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=udev%2Fudevd.c;h=4000d37e80f596b8a9d5499965b0d3ed73c3b225;hp=c9ee21a29cee0e81c0ab351468a7d9dfea752009;hb=e598c5738c2dc85a3e93c3f68cd88e8eea51215b;hpb=7d563a17f3967890331daf08d43f2f005418139b

diff --git a/udev/udevd.c b/udev/udevd.c
index c9ee21a29..4000d37e8 100644
--- a/udev/udevd.c
+++ b/udev/udevd.c
@@ -1,24 +1,21 @@
 /*
- * Copyright (C) 2004-2006 Kay Sievers <kay.sievers@vrfy.org>
+ * Copyright (C) 2004-2008 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.
+ * 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, either version 2 of the License, or
+ * (at your option) any later version.
  *
- *	This program is distributed in the hope that it will be useful, but
- *	WITHOUT ANY WARRANTY; without even the implied warranty of
- *	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- *	General Public License for more details.
- *
- *	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.,
- *	51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
  *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#include "config.h"
-
 #include <stddef.h>
 #include <signal.h>
 #include <unistd.h>
@@ -47,8 +44,12 @@
 
 #include "udev.h"
 #include "udev_rules.h"
-#include "udevd.h"
-#include "udev_selinux.h"
+
+#define UDEVD_PRIORITY			-4
+#define UDEV_PRIORITY			-2
+
+/* maximum limit of forked childs */
+#define UDEVD_MAX_CHILDS		256
 
 static int debug;
 
@@ -85,10 +86,9 @@ struct udevd_uevent_msg {
 
 static int debug_trace;
 static struct udev_rules rules;
-static int udevd_sock = -1;
+static struct udev_ctrl *udev_ctrl;
 static int uevent_netlink_sock = -1;
 static int inotify_fd = -1;
-static pid_t sid;
 
 static int signal_pipe[2] = {-1, -1};
 static volatile int sigchilds_waiting;
@@ -97,7 +97,6 @@ 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_env[32];
 
 static LIST_HEAD(exec_list);
@@ -140,7 +139,7 @@ static int udev_event_process(struct udevd_uevent_msg *msg)
 	udevice = udev_device_init(msg->udev);
 	if (udevice == NULL)
 		return -1;
-	strlcpy(udevice->action, msg->action, sizeof(udevice->action));
+	util_strlcpy(udevice->action, msg->action, sizeof(udevice->action));
 	sysfs_device_set_values(udevice->udev, udevice->dev, msg->devpath, msg->subsystem, msg->driver);
 	udevice->devpath_old = msg->devpath_old;
 	udevice->devt = msg->devt;
@@ -167,39 +166,39 @@ enum event_state {
 
 static void export_event_state(struct udevd_uevent_msg *msg, enum event_state state)
 {
-	char filename[PATH_SIZE];
-	char filename_failed[PATH_SIZE];
+	char filename[UTIL_PATH_SIZE];
+	char filename_failed[UTIL_PATH_SIZE];
 	size_t start;
 
 	/* location of queue file */
 	snprintf(filename, sizeof(filename), "%s/.udev/queue/%llu", udev_get_dev_path(msg->udev), msg->seqnum);
 
 	/* location of failed file */
-	strlcpy(filename_failed, udev_get_dev_path(msg->udev), sizeof(filename_failed));
-	strlcat(filename_failed, "/", sizeof(filename_failed));
-	start = strlcat(filename_failed, ".udev/failed/", sizeof(filename_failed));
-	strlcat(filename_failed, msg->devpath, sizeof(filename_failed));
-	path_encode(&filename_failed[start], sizeof(filename_failed) - start);
+	util_strlcpy(filename_failed, udev_get_dev_path(msg->udev), sizeof(filename_failed));
+	util_strlcat(filename_failed, "/", sizeof(filename_failed));
+	start = util_strlcat(filename_failed, ".udev/failed/", sizeof(filename_failed));
+	util_strlcat(filename_failed, msg->devpath, sizeof(filename_failed));
+	util_path_encode(&filename_failed[start], sizeof(filename_failed) - start);
 
 	switch (state) {
 	case EVENT_QUEUED:
 		unlink(filename_failed);
 		delete_path(msg->udev, filename_failed);
 		create_path(msg->udev, filename);
-		selinux_setfscreatecon(msg->udev, filename, NULL, S_IFLNK);
+		udev_selinux_setfscreatecon(msg->udev, filename, S_IFLNK);
 		symlink(msg->devpath, filename);
-		selinux_resetfscreatecon(msg->udev);
+		udev_selinux_resetfscreatecon(msg->udev);
 		break;
 	case EVENT_FINISHED:
 		if (msg->devpath_old != NULL) {
 			/* "move" event - rename failed file to current name, do not delete failed */
-			char filename_failed_old[PATH_SIZE];
+			char filename_failed_old[UTIL_PATH_SIZE];
 
-			strlcpy(filename_failed_old, udev_get_dev_path(msg->udev), sizeof(filename_failed_old));
-			strlcat(filename_failed_old, "/", sizeof(filename_failed_old));
-			start = strlcat(filename_failed_old, ".udev/failed/", sizeof(filename_failed_old));
-			strlcat(filename_failed_old, msg->devpath_old, sizeof(filename_failed_old));
-			path_encode(&filename_failed_old[start], sizeof(filename) - start);
+			util_strlcpy(filename_failed_old, udev_get_dev_path(msg->udev), sizeof(filename_failed_old));
+			util_strlcat(filename_failed_old, "/", sizeof(filename_failed_old));
+			start = util_strlcat(filename_failed_old, ".udev/failed/", sizeof(filename_failed_old));
+			util_strlcat(filename_failed_old, msg->devpath_old, sizeof(filename_failed_old));
+			util_path_encode(&filename_failed_old[start], sizeof(filename) - start);
 
 			if (rename(filename_failed_old, filename_failed) == 0)
 				info(msg->udev, "renamed devpath, moved failed state of '%s' to %s'\n",
@@ -248,7 +247,7 @@ static void udev_event_run(struct udevd_uevent_msg *msg)
 	case 0:
 		/* child */
 		close(uevent_netlink_sock);
-		close(udevd_sock);
+		udev_ctrl_unref(udev_ctrl);
 		if (inotify_fd >= 0)
 			close(inotify_fd);
 		close(signal_pipe[READ_END]);
@@ -265,7 +264,7 @@ static void udev_event_run(struct udevd_uevent_msg *msg)
 			exit(1);
 		exit(0);
 	case -1:
-		err(msg->udev, "fork of child failed: %s\n", strerror(errno));
+		err(msg->udev, "fork of child failed: %m\n");
 		msg_queue_delete(msg);
 		break;
 	default:
@@ -278,7 +277,7 @@ static void udev_event_run(struct udevd_uevent_msg *msg)
 
 static void msg_queue_insert(struct udevd_uevent_msg *msg)
 {
-	char filename[PATH_SIZE];
+	char filename[UTIL_PATH_SIZE];
 	int fd;
 
 	msg->queue_time = time(NULL);
@@ -286,8 +285,8 @@ static void msg_queue_insert(struct udevd_uevent_msg *msg)
 	export_event_state(msg, EVENT_QUEUED);
 	info(msg->udev, "seq %llu queued, '%s' '%s'\n", msg->seqnum, msg->action, msg->subsystem);
 
-	strlcpy(filename, udev_get_dev_path(msg->udev), sizeof(filename));
-	strlcat(filename, "/.udev/uevent_seqnum", sizeof(filename));
+	util_strlcpy(filename, udev_get_dev_path(msg->udev), sizeof(filename));
+	util_strlcat(filename, "/.udev/uevent_seqnum", sizeof(filename));
 	fd = open(filename, O_WRONLY|O_TRUNC|O_CREAT, 0644);
 	if (fd >= 0) {
 		char str[32];
@@ -341,119 +340,11 @@ static int mem_size_mb(void)
 	return memsize;
 }
 
-static int cpu_count(void)
-{
-	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;
-}
-
-static int running_processes(void)
-{
-	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;
-		}
-	}
-
-	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++) {
+	for (i = 0; i < UTIL_PATH_SIZE; i++) {
 		/* identical device event found */
 		if (running[i] == '\0' && waiting[i] == '\0')
 			return 1;
@@ -517,8 +408,10 @@ static int devpath_busy(struct udevd_uevent_msg *msg, int limit)
 
 	/* check run queue for still running events */
 	list_for_each_entry(loop_msg, &running_list, node) {
-		if (limit && childs_count++ > limit) {
-			dbg(msg->udev, "%llu, maximum number (%i) of childs reached\n", msg->seqnum, childs_count);
+		childs_count++;
+
+		if (childs_count++ >= limit) {
+			info(msg->udev, "%llu, maximum number (%i) of childs reached\n", msg->seqnum, childs_count);
 			return 1;
 		}
 
@@ -558,27 +451,11 @@ static void msg_queue_manager(struct udev *udev)
 {
 	struct udevd_uevent_msg *loop_msg;
 	struct udevd_uevent_msg *tmp_msg;
-	int running;
 
 	if (list_empty(&exec_list))
 		return;
 
-	running = running_processes();
-	dbg(udev, "%d processes runnning on system\n", 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(udev, "at least %d processes running in session\n", running);
-			if (running >= max_childs_running) {
-				dbg(udev, "delay seq %llu, too many processes already running\n", loop_msg->seqnum);
-				return;
-			}
-		}
-
 		/* serialize and wait for parent or child events */
 		if (devpath_busy(loop_msg, max_childs) != 0) {
 			dbg(udev, "delay seq %llu (%s)\n", loop_msg->seqnum, loop_msg->devpath);
@@ -588,7 +465,6 @@ static void msg_queue_manager(struct udev *udev)
 		/* move event to run list */
 		list_move_tail(&loop_msg->node, &running_list);
 		udev_event_run(loop_msg);
-		running++;
 		dbg(udev, "moved seq %llu to running list\n", loop_msg->seqnum);
 	}
 }
@@ -665,97 +541,70 @@ static struct udevd_uevent_msg *get_msg_from_envbuf(struct udev *udev, const cha
 }
 
 /* receive the udevd message from userspace */
-static void get_ctrl_msg(struct udev *udev)
+static void handle_ctrl_msg(struct udev_ctrl *uctrl)
 {
-	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))];
-	char *pos;
-
-	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;
-	smsg.msg_iovlen = 1;
-	smsg.msg_control = cred_msg;
-	smsg.msg_controllen = sizeof(cred_msg);
-
-	size = recvmsg(udevd_sock, &smsg, 0);
-	if (size <  0) {
-		if (errno != EINTR)
-			err(udev, "unable to receive user udevd message: %s\n", strerror(errno));
-		return;
-	}
-	cmsg = CMSG_FIRSTHDR(&smsg);
-	cred = (struct ucred *) CMSG_DATA(cmsg);
-
-	if (cmsg == NULL || cmsg->cmsg_type != SCM_CREDENTIALS) {
-		err(udev, "no sender credentials received, message ignored\n");
-		return;
-	}
+	struct udev *udev = udev_ctrl_get_udev(uctrl);
+	struct udev_ctrl_msg *ctrl_msg;
+	const char *str;
+	int i;
 
-	if (cred->uid != 0) {
-		err(udev, "sender uid=%i, message ignored\n", cred->uid);
+	ctrl_msg = udev_ctrl_receive_msg(uctrl);
+	if (ctrl_msg == NULL)
 		return;
-	}
 
-	if (strncmp(ctrl_msg.magic, UDEVD_CTRL_MAGIC, sizeof(UDEVD_CTRL_MAGIC)) != 0 ) {
-		err(udev, "message magic '%s' doesn't match, ignore it\n", ctrl_msg.magic);
-		return;
+	i = udev_ctrl_get_set_log_level(ctrl_msg);
+	if (i >= 0) {
+		info(udev, "udevd message (SET_LOG_PRIORITY) received, log_priority=%i\n", i);
+		udev_set_log_priority(udev, i);
+		sprintf(udev_log_env, "UDEV_LOG=%i", i);
+		putenv(udev_log_env);
 	}
 
-	switch (ctrl_msg.type) {
-	case UDEVD_CTRL_ENV:
-		pos = strchr(ctrl_msg.buf, '=');
-		if (pos == NULL) {
-			err(udev, "wrong key format '%s'\n", ctrl_msg.buf);
-			break;
-		}
-		pos[0] = '\0';
-		if (pos[1] == '\0') {
-			info(udev, "udevd message (ENV) received, unset '%s'\n", ctrl_msg.buf);
-			unsetenv(ctrl_msg.buf);
-		} else {
-			info(udev, "udevd message (ENV) received, set '%s=%s'\n", ctrl_msg.buf, &pos[1]);
-			setenv(ctrl_msg.buf, &pos[1], 1);
-		}
-		break;
-	case UDEVD_CTRL_STOP_EXEC_QUEUE:
+	if (udev_ctrl_get_stop_exec_queue(ctrl_msg) > 0) {
 		info(udev, "udevd message (STOP_EXEC_QUEUE) received\n");
 		stop_exec_q = 1;
-		break;
-	case UDEVD_CTRL_START_EXEC_QUEUE:
+	}
+
+	if (udev_ctrl_get_start_exec_queue(ctrl_msg) > 0) {
 		info(udev, "udevd message (START_EXEC_QUEUE) received\n");
 		stop_exec_q = 0;
 		msg_queue_manager(udev);
-		break;
-	case UDEVD_CTRL_SET_LOG_LEVEL:
-		info(udev, "udevd message (SET_LOG_PRIORITY) received, log_priority=%i\n", ctrl_msg.intval);
-		udev_set_log_priority(udev, ctrl_msg.intval);
-		sprintf(udev_log_env, "UDEV_LOG=%i", udev_get_log_priority(udev));
-		putenv(udev_log_env);
-		break;
-	case UDEVD_CTRL_SET_MAX_CHILDS:
-		info(udev, "udevd message (UDEVD_SET_MAX_CHILDS) received, max_childs=%i\n", ctrl_msg.intval);
-		max_childs = ctrl_msg.intval;
-		break;
-	case UDEVD_CTRL_SET_MAX_CHILDS_RUNNING:
-		info(udev, "udevd message (UDEVD_SET_MAX_CHILDS_RUNNING) received, max_childs_running=%i\n", ctrl_msg.intval);
-		max_childs_running = ctrl_msg.intval;
-		break;
-	case UDEVD_CTRL_RELOAD_RULES:
+	}
+
+	if (udev_ctrl_get_reload_rules(ctrl_msg) > 0) {
 		info(udev, "udevd message (RELOAD_RULES) received\n");
 		reload_config = 1;
-		break;
-	default:
-		err(udev, "unknown control message type\n");
 	}
+
+	str = udev_ctrl_get_set_env(ctrl_msg);
+	if (str != NULL) {
+		char *key = strdup(str);
+		char *val;
+
+		val = strchr(str, '=');
+		if (val != NULL) {
+			val[0] = '\0';
+			val = &val[1];
+			if (val[0] == '\0') {
+				info(udev, "udevd message (ENV) received, unset '%s'\n", key);
+				unsetenv(str);
+			} else {
+				info(udev, "udevd message (ENV) received, set '%s=%s'\n", key, val);
+				setenv(key, val, 1);
+			}
+		} else {
+			err(udev, "wrong key format '%s'\n", key);
+		}
+		free(key);
+	}
+
+	i = udev_ctrl_get_set_max_childs(ctrl_msg);
+	if (i >= 0) {
+		info(udev, "udevd message (SET_MAX_CHILDS) received, max_childs=%i\n", i);
+		max_childs = i;
+	}
+
+	udev_ctrl_msg_unref(ctrl_msg);
 }
 
 /* receive the kernel user event message and do some sanity checks */
@@ -770,7 +619,7 @@ static struct udevd_uevent_msg *get_netlink_msg(struct udev *udev)
 	size = recv(uevent_netlink_sock, &buffer, sizeof(buffer), 0);
 	if (size <  0) {
 		if (errno != EINTR)
-			err(udev, "unable to receive kernel netlink message: %s\n", strerror(errno));
+			err(udev, "unable to receive kernel netlink message: %m\n");
 		return NULL;
 	}
 
@@ -867,42 +716,6 @@ static void reap_sigchilds(void)
 	}
 }
 
-static int init_udevd_socket(struct udev *udev)
-{
-	struct sockaddr_un saddr;
-	socklen_t addrlen;
-	const int feature_on = 1;
-	int retval;
-
-	memset(&saddr, 0x00, sizeof(saddr));
-	saddr.sun_family = AF_LOCAL;
-	strcpy(saddr.sun_path, UDEVD_CTRL_SOCK_PATH);
-	addrlen = offsetof(struct sockaddr_un, sun_path) + strlen(saddr.sun_path);
-	/* translate leading '@' to abstract namespace */
-	if (saddr.sun_path[0] == '@')
-		saddr.sun_path[0] = '\0';
-
-	udevd_sock = socket(AF_LOCAL, SOCK_DGRAM, 0);
-	if (udevd_sock == -1) {
-		err(udev, "error getting socket: %s\n", 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(udev, "bind failed: %s\n", 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(struct udev *udev)
 {
 	struct sockaddr_nl snl;
@@ -916,7 +729,7 @@ static int init_uevent_netlink_sock(struct udev *udev)
 
 	uevent_netlink_sock = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_KOBJECT_UEVENT);
 	if (uevent_netlink_sock == -1) {
-		err(udev, "error getting socket: %s\n", strerror(errno));
+		err(udev, "error getting socket: %m\n");
 		return -1;
 	}
 
@@ -925,7 +738,7 @@ static int init_uevent_netlink_sock(struct udev *udev)
 
 	retval = bind(uevent_netlink_sock, (struct sockaddr *) &snl, sizeof(struct sockaddr_nl));
 	if (retval < 0) {
-		err(udev, "bind failed: %s\n", strerror(errno));
+		err(udev, "bind failed: %m\n");
 		close(uevent_netlink_sock);
 		uevent_netlink_sock = -1;
 		return -1;
@@ -935,13 +748,13 @@ static int init_uevent_netlink_sock(struct udev *udev)
 
 static void export_initial_seqnum(struct udev *udev)
 {
-	char filename[PATH_SIZE];
+	char filename[UTIL_PATH_SIZE];
 	int fd;
 	char seqnum[32];
 	ssize_t len = 0;
 
-	strlcpy(filename, udev_get_sys_path(udev), sizeof(filename));
-	strlcat(filename, "/kernel/uevent_seqnum", sizeof(filename));
+	util_strlcpy(filename, udev_get_sys_path(udev), sizeof(filename));
+	util_strlcat(filename, "/kernel/uevent_seqnum", sizeof(filename));
 	fd = open(filename, O_RDONLY);
 	if (fd >= 0) {
 		len = read(fd, seqnum, sizeof(seqnum)-1);
@@ -951,8 +764,8 @@ static void export_initial_seqnum(struct udev *udev)
 		strcpy(seqnum, "0\n");
 		len = 3;
 	}
-	strlcpy(filename, udev_get_dev_path(udev), sizeof(filename));
-	strlcat(filename, "/.udev/uevent_seqnum", sizeof(filename));
+	util_strlcpy(filename, udev_get_dev_path(udev), sizeof(filename));
+	util_strlcat(filename, "/.udev/uevent_seqnum", sizeof(filename));
 	create_path(udev, filename);
 	fd = open(filename, O_WRONLY|O_TRUNC|O_CREAT, 0644);
 	if (fd >= 0) {
@@ -971,11 +784,11 @@ int main(int argc, char *argv[])
 	const char *value;
 	int daemonize = 0;
 	static const struct option options[] = {
-		{ "daemon", 0, NULL, 'd' },
-		{ "debug-trace", 0, NULL, 't' },
-		{ "debug", 0, NULL, 'D' },
-		{ "help", 0, NULL, 'h' },
-		{ "version", 0, NULL, 'V' },
+		{ "daemon", no_argument, NULL, 'd' },
+		{ "debug-trace", no_argument, NULL, 't' },
+		{ "debug", no_argument, NULL, 'D' },
+		{ "help", no_argument, NULL, 'h' },
+		{ "version", no_argument, NULL, 'V' },
 		{}
 	};
 	int rc = 1;
@@ -987,9 +800,8 @@ int main(int argc, char *argv[])
 
 	logging_init("udevd");
 	udev_set_log_fn(udev, log_fn);
-
-	selinux_init(udev);
 	dbg(udev, "version %s\n", VERSION);
+	selinux_init(udev);
 
 	while (1) {
 		int option;
@@ -1040,17 +852,19 @@ int main(int argc, char *argv[])
 	if (write(STDERR_FILENO, 0, 0) < 0)
 		dup2(fd, STDERR_FILENO);
 
-	/* init sockets to receive events */
-	if (init_udevd_socket(udev) < 0) {
-		if (errno == EADDRINUSE) {
-			fprintf(stderr, "another udev daemon already running\n");
-			err(udev, "another udev daemon already running\n");
-			rc = 1;
-		} else {
-			fprintf(stderr, "error initializing udevd socket\n");
-			err(udev, "error initializing udevd socket\n");
-			rc = 2;
-		}
+	/* init control socket, bind() ensures, that only one udevd instance is running */
+	udev_ctrl = udev_ctrl_new_from_socket(udev, UDEV_CTRL_SOCK_PATH);
+	if (udev_ctrl == NULL) {
+		fprintf(stderr, "error initializing control socket");
+		err(udev, "error initializing udevd socket");
+		rc = 1;
+		goto exit;
+	}
+
+	if (udev_ctrl_enable_receiving(udev_ctrl) < 0) {
+		fprintf(stderr, "error binding control socket, seems udevd is already running\n");
+		err(udev, "error binding control socket, seems udevd is already running\n");
+		rc = 1;
 		goto exit;
 	}
 
@@ -1061,32 +875,31 @@ int main(int argc, char *argv[])
 		goto exit;
 	}
 
-	/* setup signal handler pipe */
 	retval = pipe(signal_pipe);
 	if (retval < 0) {
-		err(udev, "error getting pipes: %s\n", strerror(errno));
+		err(udev, "error getting pipes: %m\n");
 		goto exit;
 	}
 
 	retval = fcntl(signal_pipe[READ_END], F_GETFL, 0);
 	if (retval < 0) {
-		err(udev, "error fcntl on read pipe: %s\n", strerror(errno));
+		err(udev, "error fcntl on read pipe: %m\n");
 		goto exit;
 	}
 	retval = fcntl(signal_pipe[READ_END], F_SETFL, retval | O_NONBLOCK);
 	if (retval < 0) {
-		err(udev, "error fcntl on read pipe: %s\n", strerror(errno));
+		err(udev, "error fcntl on read pipe: %m\n");
 		goto exit;
 	}
 
 	retval = fcntl(signal_pipe[WRITE_END], F_GETFL, 0);
 	if (retval < 0) {
-		err(udev, "error fcntl on write pipe: %s\n", strerror(errno));
+		err(udev, "error fcntl on write pipe: %m\n");
 		goto exit;
 	}
 	retval = fcntl(signal_pipe[WRITE_END], F_SETFL, retval | O_NONBLOCK);
 	if (retval < 0) {
-		err(udev, "error fcntl on write pipe: %s\n", strerror(errno));
+		err(udev, "error fcntl on write pipe: %m\n");
 		goto exit;
 	}
 
@@ -1105,7 +918,7 @@ int main(int argc, char *argv[])
 			dbg(udev, "daemonized fork running\n");
 			break;
 		case -1:
-			err(udev, "fork of daemon failed: %s\n", strerror(errno));
+			err(udev, "fork of daemon failed: %m\n");
 			rc = 4;
 			goto exit;
 		default:
@@ -1115,10 +928,11 @@ int main(int argc, char *argv[])
 		}
 	}
 
-	/* redirect std{out,err} fd's */
-	if (!debug)
+	/* redirect std{out,err} */
+	if (!debug) {
 		dup2(fd, STDOUT_FILENO);
-	dup2(fd, STDERR_FILENO);
+		dup2(fd, STDERR_FILENO);
+	}
 	if (fd > STDERR_FILENO)
 		close(fd);
 
@@ -1127,15 +941,12 @@ int main(int argc, char *argv[])
 
 	chdir("/");
 	umask(022);
-
-	/* become session leader */
-	sid = setsid();
-	dbg(udev, "our session is %d\n", sid);
+	setsid();
 
 	/* OOM_DISABLE == -17 */
 	fd = open("/proc/self/oom_adj", O_RDWR);
 	if (fd < 0)
-		err(udev, "error disabling OOM: %s\n", strerror(errno));
+		err(udev, "error disabling OOM: %m\n");
 	else {
 		write(fd, "-17", 3);
 		close(fd);
@@ -1143,9 +954,21 @@ int main(int argc, char *argv[])
 
 	fd = open("/dev/kmsg", O_WRONLY);
 	if (fd > 0) {
-		const char *str = "<6>udevd version " VERSION " started\n";
-
-		write(fd, str, strlen(str));
+		const char *ver_str = "<6>udev: starting version " VERSION "\n";
+		char path[UTIL_PATH_SIZE];
+		struct stat statbuf;
+
+		write(fd, ver_str, strlen(ver_str));
+		util_strlcpy(path, udev_get_sys_path(udev), sizeof(path));
+		util_strlcat(path, "/class/mem/null", sizeof(path));
+		if (lstat(path, &statbuf) == 0) {
+			if (S_ISDIR(statbuf.st_mode)) {
+				const char *depr_str = "<6>udev: deprecated sysfs layout "
+						       "(CONFIG_SYSFS_DEPRECATED) is unsupported\n";
+
+				write(fd, depr_str, strlen(depr_str));
+			}
+		}
 		close(fd);
 	}
 
@@ -1174,15 +997,15 @@ int main(int argc, char *argv[])
 					  IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
 
 			/* watch dynamic rules directory */
-			strlcpy(filename, udev_get_dev_path(udev), sizeof(filename));
-			strlcat(filename, "/.udev/rules.d", sizeof(filename));
+			util_strlcpy(filename, udev_get_dev_path(udev), sizeof(filename));
+			util_strlcat(filename, "/.udev/rules.d", sizeof(filename));
 			inotify_add_watch(inotify_fd, filename,
 					  IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
 		}
 	} else if (errno == ENOSYS)
 		err(udev, "the kernel does not support inotify, udevd can't monitor rules file changes\n");
 	else
-		err(udev, "inotify_init failed: %s\n", strerror(errno));
+		err(udev, "inotify_init failed: %m\n");
 
 	/* maximum limit of forked childs */
 	value = getenv("UDEVD_MAX_CHILDS");
@@ -1197,19 +1020,6 @@ int main(int argc, char *argv[])
 	}
 	info(udev, "initialize max_childs to %u\n", max_childs);
 
-	/* 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(udev, "initialize max_childs_running to %u\n", max_childs_running);
-
 	/* clear environment for forked event processes */
 	clearenv();
 
@@ -1219,7 +1029,7 @@ int main(int argc, char *argv[])
 	if (debug_trace)
 		putenv("DEBUG=1");
 
-	maxfd = udevd_sock;
+	maxfd = udev_ctrl_get_fd(udev_ctrl);
 	maxfd = UDEV_MAX(maxfd, uevent_netlink_sock);
 	maxfd = UDEV_MAX(maxfd, signal_pipe[READ_END]);
 	maxfd = UDEV_MAX(maxfd, inotify_fd);
@@ -1230,7 +1040,7 @@ int main(int argc, char *argv[])
 
 		FD_ZERO(&readfds);
 		FD_SET(signal_pipe[READ_END], &readfds);
-		FD_SET(udevd_sock, &readfds);
+		FD_SET(udev_ctrl_get_fd(udev_ctrl), &readfds);
 		FD_SET(uevent_netlink_sock, &readfds);
 		if (inotify_fd >= 0)
 			FD_SET(inotify_fd, &readfds);
@@ -1238,13 +1048,13 @@ int main(int argc, char *argv[])
 		fdcount = select(maxfd+1, &readfds, NULL, NULL, NULL);
 		if (fdcount < 0) {
 			if (errno != EINTR)
-				err(udev, "error in select: %s\n", strerror(errno));
+				err(udev, "error in select: %m\n");
 			continue;
 		}
 
 		/* get control message */
-		if (FD_ISSET(udevd_sock, &readfds))
-			get_ctrl_msg(udev);
+		if (FD_ISSET(udev_ctrl_get_fd(udev_ctrl), &readfds))
+			handle_ctrl_msg(udev_ctrl);
 
 		/* get netlink message */
 		if (FD_ISSET(uevent_netlink_sock, &readfds)) {
@@ -1304,20 +1114,20 @@ int main(int argc, char *argv[])
 exit:
 	udev_rules_cleanup(&rules);
 	sysfs_cleanup();
-	selinux_exit(udev);
 
 	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);
+	udev_ctrl_unref(udev_ctrl);
 	if (inotify_fd >= 0)
 		close(inotify_fd);
 	if (uevent_netlink_sock >= 0)
 		close(uevent_netlink_sock);
 
+	selinux_exit(udev);
+	udev_unref(udev);
 	logging_close();
 	return rc;
 }