#!/bin/sh -e
### BEGIN INIT INFO
# Provides:          udev
# Required-Start:    mountkernfs
# Required-Stop:     umountroot
# Default-Start:     S
# Default-Stop:      0 6
# Short-Description: Start systemd-udevd, populate /dev and load drivers.
### END INIT INFO

PATH="/usr/sbin:/usr/bin:/sbin:/bin"
NAME="systemd-udevd"
DAEMON="/lib/systemd/systemd-udevd"
DESC="hotplug events dispatcher"
PIDFILE="/run/udev.pid"
CTRLFILE="/run/udev/control"
OMITDIR="/run/sendsigs.omit.d"

# we need to unmount /dev/pts/ and remount it later over the devtmpfs
unmount_devpts() {
	if mountpoint -q /dev/pts/; then
		umount -n -l /dev/pts/
	fi

	if mountpoint -q /dev/shm/; then
		umount -n -l /dev/shm/
	fi
}

# mount a devtmpfs over /dev, if somebody did not already do it
mount_devtmpfs() {
	if grep -E -q "^[^[:space:]]+ /dev devtmpfs" /proc/mounts; then
		mount -n -o remount,nosuid,size=$tmpfs_size,mode=0755 -t devtmpfs devtmpfs /dev
		return
	fi

	if ! mount -n -o nosuid,size=$tmpfs_size,mode=0755 -t devtmpfs devtmpfs /dev; then
		log_failure_msg "udev requires devtmpfs support, not started"
		log_end_msg 1
	fi

	return 0
}

create_dev_makedev() {
	if [ -e /sbin/MAKEDEV ]; then
		ln -sf /sbin/MAKEDEV /dev/MAKEDEV
	else
		ln -sf /bin/true /dev/MAKEDEV
	fi
}

# shell version of /usr/bin/tty
my_tty() {
	[ -x /bin/readlink ] || return 0
	[ -e /proc/self/fd/0 ] || return 0
	readlink --silent /proc/self/fd/0 || true
}

warn_if_interactive() {
	if [ "$RUNLEVEL" = "S" ] && [ "$PREVLEVEL" = "N" ]; then
		return
	fi

	TTY=$(my_tty)
	if [ -z "$TTY" ] || [ "$TTY" = "/dev/console" ] || [ "$TTY" = "/dev/null" ]; then
		return
	fi

	printf "\n\n\nIt has been detected that the command\n\n\t$0 $*\n\n"
	printf "has been run from an interactive shell.\n"
	printf "It will probably not do what you expect, so this script will wait\n"
	printf "60 seconds before continuing. Press ^C to stop it.\n"
	printf "RUNNING THIS COMMAND IS HIGHLY DISCOURAGED!\n\n\n\n"
	sleep 60
}

make_static_nodes() {
	[ -e /lib/modules/$(uname -r)/modules.devname ] || return 0
	[ -x /bin/kmod ] || return 0

	/bin/kmod static-nodes --format=tmpfiles --output=/proc/self/fd/1 |
		while read type name mode uid gid age arg; do
			[ -e $name ] && continue
			case "$type" in
				c | b | c! | b!) mknod -m $mode $name $type $(echo $arg | sed 's/:/ /') ;;
				d | d!) mkdir $name ;;
				*) echo "unparseable line ($type $name $mode $uid $gid $age $arg)" >&2 ;;
			esac

			if [ -x /sbin/restorecon ]; then
				/sbin/restorecon $name
			fi
		done
}

##############################################################################

[ -x $DAEMON ] || exit 0

# defaults
tmpfs_size="10M"

if [ -e /etc/udev/udev.conf ]; then
	. /etc/udev/udev.conf
fi

. /lib/lsb/init-functions

if [ ! -e /proc/filesystems ]; then
	log_failure_msg "udev requires a mounted procfs, not started"
	log_end_msg 1
fi

if ! grep -q '[[:space:]]devtmpfs$' /proc/filesystems; then
	log_failure_msg "udev requires devtmpfs support, not started"
	log_end_msg 1
fi

if [ ! -d /sys/class/ ]; then
	log_failure_msg "udev requires a mounted sysfs, not started"
	log_end_msg 1
fi

if [ ! -w /sys ]; then
	log_warning_msg "udev does not support containers, not started"
	exit 0
fi

if [ "$(stat -c %d/%i /)" != "$(stat -Lc %d/%i /proc/1/root 2>/dev/null)" ]; then
	# the devicenumber/inode pair of / is not the same as that of /sbin/init's
	# root, so we *are* in a chroot.
	log_warning_msg "A chroot environment has been detected, udev not started."
	exit 0
fi

if [ -d /sys/class/mem/null ] && [ ! -L /sys/class/mem/null ] ||
	[ -e /sys/block ] && [ ! -e /sys/class/block ]; then
	log_warning_msg "CONFIG_SYSFS_DEPRECATED must not be selected"
	log_warning_msg "Booting will continue in 30 seconds but many things will be broken"
	sleep 30
fi

# When modifying this script, do not forget that between the time that the
# new /dev has been mounted and udevadm trigger has been run there will be
# no /dev/null. This also means that you cannot use the "&" shell command.

case "$1" in
	start)
		if [ ! -e "/run/udev/" ]; then
			warn_if_interactive
		fi

		if [ -w /sys/kernel/uevent_helper ]; then
			echo >/sys/kernel/uevent_helper
		fi

		if ! mountpoint -q /dev/; then
			unmount_devpts
			mount_devtmpfs
			[ -d /proc/1 ] || mount -n /proc
		fi

		make_static_nodes

		# clean up parts of the database created by the initramfs udev
		udevadm info --cleanup-db

		# set the SELinux context for devices created in the initramfs
		[ -x /sbin/restorecon ] && /sbin/restorecon -R /dev

		log_daemon_msg "Starting $DESC" "$NAME"
		if start-stop-daemon --start --name $NAME --user root --quiet \
			--pidfile $PIDFILE --exec $DAEMON --background --make-pidfile \
			--notify-await; then
			# prevents udevd to be killed by sendsigs (see #791944)
			mkdir -p $OMITDIR
			ln -sf $PIDFILE $OMITDIR/$NAME
			log_end_msg $?
		else
			log_warning_msg $?
			log_warning_msg "Waiting 15 seconds and trying to continue anyway"
			sleep 15
		fi

		log_action_begin_msg "Synthesizing the initial hotplug events (subsystems)"
		if udevadm trigger --type=subsystems --action=add; then
			log_action_end_msg $?
		else
			log_action_end_msg $?
		fi
		log_action_begin_msg "Synthesizing the initial hotplug events (devices)"
		if udevadm trigger --type=devices --action=add; then
			log_action_end_msg $?
		else
			log_action_end_msg $?
		fi

		create_dev_makedev

		# wait for the systemd-udevd childs to finish
		log_action_begin_msg "Waiting for /dev to be fully populated"
		if udevadm settle; then
			log_action_end_msg 0
		else
			log_action_end_msg 0 'timeout'
		fi
		;;

	stop)
		log_daemon_msg "Stopping $DESC" "$NAME"
		if start-stop-daemon --stop --name $NAME --user root --quiet \
			--pidfile $PIDFILE --remove-pidfile --oknodo --retry 5; then
			# prevents cryptsetup/dmsetup hangs (see #791944)
			rm -f $CTRLFILE
			log_end_msg $?
		else
			log_end_msg $?
		fi
		;;

	restart)
		log_daemon_msg "Stopping $DESC" "$NAME"
		if start-stop-daemon --stop --name $NAME --user root --quiet \
			--pidfile $PIDFILE --remove-pidfile --oknodo --retry 5; then
			# prevents cryptsetup/dmsetup hangs (see #791944)
			rm -f $CTRLFILE
			log_end_msg $?
		else
			log_end_msg $? || true
		fi

		log_daemon_msg "Starting $DESC" "$NAME"
		if start-stop-daemon --start --name $NAME --user root --quiet \
			--pidfile $PIDFILE --exec $DAEMON --background --make-pidfile \
			--notify-await; then
			# prevents udevd to be killed by sendsigs (see #791944)
			mkdir -p $OMITDIR
			ln -sf $PIDFILE $OMITDIR/$NAME
			log_end_msg $?
		else
			log_end_msg $?
		fi
		;;

	reload | force-reload)
		udevadm control --reload-rules
		;;

	status)
		status_of_proc $DAEMON $NAME && exit 0 || exit $?
		;;

	*)
		echo "Usage: /etc/init.d/udev {start|stop|restart|reload|force-reload|status}" >&2
		exit 1
		;;
esac

exit 0
