#!/bin/sh
#save/load users and groups from/to flash (not TFFS)

SAVE_DIR=/tmp/flash/users
FILES="passwd group shadow gshadow"

load() {
	mkdir -pm 700 $SAVE_DIR
	# temporary file
	touch "/tmp/passwd.mod"
	chmod 644 "/tmp/passwd.mod"
	cat /tmp/passwd > /tmp/passwd.mod
	for f in $FILES; do
		# set permissions: 644 for passwd & group, 600 for shadow & gshadow
		touch "/tmp/$f"
		[ "$f" == "${f%shadow}" ] && chmod 644 "/tmp/$f" || chmod 600 "/tmp/$f"
		# existing settings available?
		if [ ! -e "$SAVE_DIR/$f" ]; then
			# save default users&groups from var.tar
			cat "/tmp/$f" > "$SAVE_DIR/$f" 2>/dev/null
		else
			# load saved freetz-users & -groups from flash
			grep -vE '^(app|boxusr|ftpuser)[0-9]*(int|-internet)*:' "$SAVE_DIR/$f" | sort -u > "/tmp/${f/passwd/passwd.mod}" 2>/dev/null
		fi
	done
	# read updated defaults from var.tar
	for f in passwd.mod group; do
		tar xOf /var.tar ./var/tmp/${f%.mod} | while read l; do grep -q "^${l%%:*}:" /tmp/$f || echo "$l" >> /tmp/$f; done
	done
	# no update by ctlmgr (manual load), so use current values
	[ ! -e /tmp/passwd.tmp ] && cp -a /tmp/passwd /tmp/passwd.tmp 2>/dev/null
	# load AVM's app-users, boxusrs (and ftpusers) which were created by ctlmgr
	grep -E '^(app|boxusr|ftpuser)[0-9]*(int|-internet)*:' /tmp/passwd.tmp >> /tmp/passwd.mod 2>/dev/null
	# special case: ftpuser is created and/or used by avm and/or freetz
	grep -q "^ftpuser:" /tmp/passwd.mod || grep "^ftpuser:" "$SAVE_DIR/passwd" >> /tmp/passwd.mod 2>/dev/null
	# /tmp/passwd.tmp is created by ctlmgr (during changes), do NOT MoVe due to libctlmgr
	rm -f /tmp/passwd.tmp
	# prevent race-condition while creating /etc/passwd
	mv /tmp/passwd.mod /tmp/passwd
	touch /tmp/.usersloaded
}

save() {
	local rc=0
	[ ! -e /tmp/.usersloaded ] && return 1
	rm -rf $SAVE_DIR
	mkdir -pm 700 $SAVE_DIR
	for f in $FILES; do
		cp -p "/tmp/$f" "$SAVE_DIR/$f" || rc=1
	done
	return $rc
}

case $1 in
	load)
		load
		;;
	save)
		save
		;;
	update)
		save
		load
		;;
	*)
		echo "Usage: $0 [load|save|update]" 1>&2
		exit 1
		;;
esac