#!/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/$f" 2>/dev/null
		else
			# load saved users&groups from flash
			grep -vE "^boxusr|^ftpuser" "$SAVE_DIR/$f" > "/tmp/${f/passwd/passwd.mod}" 2>/dev/null
		fi
	done
	# /var/tmp/passwd.tmp is created by ctlmgr, do NOT MoVe due to libctlmgr
	cp /var/tmp/passwd.tmp /var/tmp/passwd.avm 2>/dev/null && rm -rf /var/tmp/passwd.tmp
	# load AVM's boxusers (and ftpuser) which were created by ctlmgr
	[ -e /var/tmp/passwd.avm ] && grep -v "^root:" /var/tmp/passwd.avm >> /tmp/passwd.mod
	# 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
	# prevent race-condition while creating /etc/passwd
	mv /tmp/passwd.mod /tmp/passwd
	touch /tmp/.usersloaded
}

save() {
	[ ! -e /tmp/.usersloaded ] && return 1
	rm -rf $SAVE_DIR
	mkdir -pm 700 $SAVE_DIR
	for f in $FILES; do
		cat "/tmp/$f" > "$SAVE_DIR/$f" 2>/dev/null
	done
}

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