#!/bin/sh
### BEGIN INIT INFO
# Provides:             volatile
# Required-Start:       $local_fs
# Required-Stop:      $local_fs
# Default-Start:        S
# Default-Stop:
# Short-Description:  Populate the volatile filesystem
### END INIT INFO

# Get ROOT_DIR
DIRNAME=`dirname $0`
ROOT_DIR=`echo $DIRNAME | sed -ne 's:/etc/.*::p'`

[ -e ${ROOT_DIR}/etc/default/rcS ] && . ${ROOT_DIR}/etc/default/rcS
# When running populate-volatile.sh at rootfs time, disable cache.
[ -n "$ROOT_DIR" ] && VOLATILE_ENABLE_CACHE=no
# If rootfs is read-only, disable cache.
[ "$ROOTFS_READ_ONLY" = "yes" ] && VOLATILE_ENABLE_CACHE=no

CFGDIR="${ROOT_DIR}/etc/default/volatiles"
TMPROOT="${ROOT_DIR}/var/volatile/tmp"
COREDEF="00_core"

[ "${VERBOSE}" != "no" ] && echo "Populating volatile Filesystems."

create_file() {
	EXEC="
	touch \"$1\";
	chown ${TUSER}.${TGROUP} $1 || echo \"Failed to set owner -${TUSER}- for -$1-.\" >/dev/tty0 2>&1;
	chmod ${TMODE} $1 || echo \"Failed to set mode -${TMODE}- for -$1-.\" >/dev/tty0 2>&1 "

	test "$VOLATILE_ENABLE_CACHE" = yes && echo "$EXEC" >> /etc/volatile.cache.build

	[ -e "$1" ] && {
		[ "${VERBOSE}" != "no" ] && echo "Target already exists. Skipping."
	} || {
		if [ -z "$ROOT_DIR" ]; then
			eval $EXEC
		else
			# Creating some files at rootfs time may fail and should fail,
			# but these failures should not be logged to make sure the do_rootfs
			# process doesn't fail. This does no harm, as this script will
			# run on target to set up the correct files and directories.
			eval $EXEC > /dev/null 2>&1
		fi
	}
}

mk_dir() {
	EXEC="
	mkdir -p \"$1\";
	chown ${TUSER}.${TGROUP} $1 || echo \"Failed to set owner -${TUSER}- for -$1-.\" >/dev/tty0 2>&1;
	chmod ${TMODE} $1 || echo \"Failed to set mode -${TMODE}- for -$1-.\" >/dev/tty0 2>&1 "

	test "$VOLATILE_ENABLE_CACHE" = yes && echo "$EXEC" >> /etc/volatile.cache.build
	[ -e "$1" ] && {
		[ "${VERBOSE}" != "no" ] && echo "Target already exists. Skipping."
	} || {
		if [ -z "$ROOT_DIR" ]; then
			eval $EXEC
		else
			# For the same reason with create_file(), failures should
			# not be logged.
			eval $EXEC > /dev/null 2>&1
		fi
	}
}

link_file() {
	EXEC="
	if [ -L \"$2\" ]; then
		[ \"\$(readlink -f \"$2\")\" != \"$1\" ] && { rm -f \"$2\"; ln -sf \"$1\" \"$2\"; };
	elif [ -d \"$2\" ]; then
		if awk '\$2 == \"$2\" {exit 1}' /proc/mounts; then
			cp -a $2/* $1 2>/dev/null;
			cp -a $2/.[!.]* $1 2>/dev/null;
			rm -rf \"$2\";
			ln -sf \"$1\" \"$2\";
		fi
	else
		ln -sf \"$1\" \"$2\";
	fi
        "

	test "$VOLATILE_ENABLE_CACHE" = yes && echo "	$EXEC" >> /etc/volatile.cache.build

	if [ -z "$ROOT_DIR" ]; then
		eval $EXEC
	else
		# For the same reason with create_file(), failures should
		# not be logged.
		eval $EXEC > /dev/null 2>&1
	fi
}

check_requirements() {
	cleanup() {
		rm "${TMP_INTERMED}"
		rm "${TMP_DEFINED}"
		rm "${TMP_COMBINED}"
	}

	CFGFILE="$1"
	[ `basename "${CFGFILE}"` = "${COREDEF}" ] && return 0

	TMP_INTERMED="${TMPROOT}/tmp.$$"
	TMP_DEFINED="${TMPROOT}/tmpdefined.$$"
	TMP_COMBINED="${TMPROOT}/tmpcombined.$$"

	sed 's@\(^:\)*:.*@\1@' ${ROOT_DIR}/etc/passwd | sort | uniq > "${TMP_DEFINED}"
	cat ${CFGFILE} | grep -v "^#" | cut -s -d " " -f 2 > "${TMP_INTERMED}"
	cat "${TMP_DEFINED}" "${TMP_INTERMED}" | sort | uniq > "${TMP_COMBINED}"
	NR_DEFINED_USERS="`cat "${TMP_DEFINED}" | wc -l`"
	NR_COMBINED_USERS="`cat "${TMP_COMBINED}" | wc -l`"

	[ "${NR_DEFINED_USERS}" -ne "${NR_COMBINED_USERS}" ] && {
		echo "Undefined users:"
		diff "${TMP_DEFINED}" "${TMP_COMBINED}" | grep "^>"
		cleanup
		return 1
	}


	sed 's@\(^:\)*:.*@\1@' ${ROOT_DIR}/etc/group | sort | uniq > "${TMP_DEFINED}"
	cat ${CFGFILE} | grep -v "^#" | cut -s -d " " -f 3 > "${TMP_INTERMED}"
	cat "${TMP_DEFINED}" "${TMP_INTERMED}" | sort | uniq > "${TMP_COMBINED}"

	NR_DEFINED_GROUPS="`cat "${TMP_DEFINED}" | wc -l`"
	NR_COMBINED_GROUPS="`cat "${TMP_COMBINED}" | wc -l`"

	[ "${NR_DEFINED_GROUPS}" -ne "${NR_COMBINED_GROUPS}" ] && {
		echo "Undefined groups:"
		diff "${TMP_DEFINED}" "${TMP_COMBINED}" | grep "^>"
		cleanup
		return 1
	}

	# Add checks for required directories here

	cleanup
	return 0
}

apply_cfgfile() {
	CFGFILE="$1"

	check_requirements "${CFGFILE}" || {
		echo "Skipping ${CFGFILE}"
		return 1
	}

	cat ${CFGFILE} | sed 's/#.*//' | \
	while read TTYPE TUSER TGROUP TMODE TNAME TLTARGET; do
		test -z "${TLTARGET}" && continue
		TNAME=${ROOT_DIR}${TNAME}
		[ "${VERBOSE}" != "no" ] && echo "Checking for -${TNAME}-."

		[ "${TTYPE}" = "l" ] && {
			TSOURCE="$TLTARGET"
			[ "${VERBOSE}" != "no" ] && echo "Creating link -${TNAME}- pointing to -${TSOURCE}-."
			link_file "${TSOURCE}" "${TNAME}"
			continue
		}

		[ "${TTYPE}" = "b" ] && {
			TSOURCE="$TLTARGET"
			[ "${VERBOSE}" != "no" ] && echo "Creating mount-bind -${TNAME}- from -${TSOURCE}-."
			mount --bind "${TSOURCE}" "${TNAME}"
			EXEC="
	mount --bind \"${TSOURCE}\" \"${TNAME}\""
			test "$VOLATILE_ENABLE_CACHE" = yes && echo "$EXEC" >> /etc/volatile.cache.build
			continue
		}

		[ -L "${TNAME}" ] && {
			[ "${VERBOSE}" != "no" ] && echo "Found link."
			NEWNAME=`ls -l "${TNAME}" | sed -e 's/^.*-> \(.*\)$/\1/'`
			echo ${NEWNAME} | grep -v "^/" >/dev/null && {
				TNAME="`echo ${TNAME} | sed -e 's@\(.*\)/.*@\1@'`/${NEWNAME}"
				[ "${VERBOSE}" != "no" ] && echo "Converted relative linktarget to absolute path -${TNAME}-."
			} || {
				TNAME="${NEWNAME}"
				[ "${VERBOSE}" != "no" ] && echo "Using absolute link target -${TNAME}-."
			}
		}

		case "${TTYPE}" in
			"f")  [ "${VERBOSE}" != "no" ] && echo "Creating file -${TNAME}-."
				create_file "${TNAME}"
				;;
			"d")  [ "${VERBOSE}" != "no" ] && echo "Creating directory -${TNAME}-."
				mk_dir "${TNAME}"
				# Add check to see if there's an entry in fstab to mount.
				;;
			*)    [ "${VERBOSE}" != "no" ] && echo "Invalid type -${TTYPE}-."
				continue
				;;
		esac
	done
	return 0
}

clearcache=0
exec 9</proc/cmdline
while read line <&9
do
	case "$line" in
		*clearcache*)  clearcache=1
			       ;;
		*)	       continue
			       ;;
	esac
done
exec 9>&-

if test -e ${ROOT_DIR}/etc/volatile.cache -a "$VOLATILE_ENABLE_CACHE" = "yes" -a "x$1" != "xupdate" -a "x$clearcache" = "x0"
then
	sh ${ROOT_DIR}/etc/volatile.cache
else
	rm -f ${ROOT_DIR}/etc/volatile.cache ${ROOT_DIR}/etc/volatile.cache.build
	for file in `ls -1 "${CFGDIR}" | sort`; do
		apply_cfgfile "${CFGDIR}/${file}"
	done

	[ -e ${ROOT_DIR}/etc/volatile.cache.build ] && sync && mv ${ROOT_DIR}/etc/volatile.cache.build ${ROOT_DIR}/etc/volatile.cache
fi

if [ -z "${ROOT_DIR}" ] && [ -f /etc/ld.so.cache ] && [ ! -f /var/run/ld.so.cache ]
then
	ln -s /etc/ld.so.cache /var/run/ld.so.cache
fi
