#!/bin/sh
#
# this script does EVERYTHING
# all other scripts are only frontends :)
#
# called by:
#	- some rc-scripts
#	- the web frontend cgi
#

set -eu

# parse config file
. /etc/cryptobox/cryptobox.conf

## configuration
CONFIG_MARKER="$CONFIG_DIR/cryptobox.marker"
CERT_TEMP=/tmp/stunnel.pem

#####

log_msg()
{
	# the log file is not writable during boot - try before writing ...
	[ -w "$LOG_FILE" ] || return 0
	echo >>"$LOG_FILE"
	echo "################ `date` ####################" >>"$LOG_FILE"
	echo "$1" >>"$LOG_FILE"
}


function error_msg()
# parameters: ExitCode ErrorMessage
{
	echo "[`date`] - $2" | tee -a "$LOG_FILE" >&2
	# print the execution stack - not usable with busybox
	#caller | sed 's/^/\t/' >&2
	exit "$1"
}


function initial_checks()
# Parameter: device
{
	local device="$1"
	[ ! -b "$device" ] && log_msg "blockdevice $device does not exist" && return 1
	## check if we have an existing configpartition
	## TODO: why this config_mount_test?
	# config_mount_test "$device"
	[ ! -x "$WIPE" ] && log_msg "$WIPE not found" && return 1
	[ ! -x "$SFDISK" ] && log_msg "$SFDISK not found" && return 1
	for a in $ALGO $HASH
		do	grep -q "^name *: $a$" /proc/crypto || modprobe "$a"
			grep -q "^name *: $a$" /proc/crypto || { log_msg "$a is not supported by kernel" && return 1; }
	  done
	log_msg "inital checks successful"
	return 0
}


function create_partitions()
# Parameter: device
{
	local device="$1"
	# first partition size is 1 sector, second goes til end
	# sfdisk -n doesn't actually write (for testing purpose)
	echo -e "0,1,L \n,,L\n" | $SFDISK "$device"
}


function config_set_value()
# parameters: SettingName SettingValue
{
	mount -o rw,remount "$CONFIG_DIR"
	echo -n "$2" > "$CONFIG_DIR/$1"
	mount -o ro,remount "$CONFIG_DIR"
}


function config_get_value()
# parameters: SettingName
{
	# use mounted config, if it exists - otherwise use defaults
	local conf_dir
	if is_config_mounted
		then	conf_dir=$CONFIG_DIR
		else	conf_dir=$CONFIG_DEFAULTS_DIR
	  fi
	[ -z "$1" ] && error_msg 1 "empty setting name"
	[ ! -e "$conf_dir/$1" ] && error_msg 2 "unknown configuration value ($1)"
	# remove trailing line break
	echo -n $(cat "$conf_dir/$1")
}


function create_config()
# Parameter: device
{
	local device="${1}1"
	log_msg "Creating config filesystem ..."
	$MKFS_CONFIG "$device"
	# mount the config partition rw
	log_msg "Mounting config partition ..."
	mount "$device" "$CONFIG_DIR"
	# create a marker to recognize a cryptobox partition
	date -I >"$CONFIG_MARKER" 
	log_msg "Copying configuration defaults ..."
	cp -a "$CONFIG_DEFAULTS_DIR/." "$CONFIG_DIR"

	log_msg "Copying temporary cerificate file to config filesystem ..."
	cp -p "$CERT_TEMP" "$CERT_FILE"

	log_msg "Setting inital values ..."
	# beware: config_set_value remounts the config partition read-only
	config_set_value "device" "$1"

	config_set_value "ip" "$(get_current_ip)"

	# reinitialise configuration
	log_msg "Unmounting config partition ..."
	umount "$CONFIG_DIR"
	log_msg "Reload configuration ..."
	mount_config
}


function get_current_ip()
# not necessarily the same as configured (necessary for validation)
{
	# filter the output of ifconfig and remove trailing line break
	echo -n $(ifconfig $NET_IFACE | grep "inet" | cut -d ":" -f2 | cut -d " " -f1)
}


function create_crypto()
# Parameter: device
{
	local device="$1"
	# flood the crypto partition with noise
	# - not needed -
	#$WIPE -kq -R /dev/urandom "${device}2"

	# passphrase may be passed via command line
	$CRYPTSETUP -h "$HASH" -c "$ALGO" create "`basename $CRYPTMAPPER_DEV`" "${device}2"
}


function mkfs_crypto()
# split from create_crypto to allow background execution via web interface
{
	$MKFS_DATA "$CRYPTMAPPER_DEV"
}


function config_mount_test()
# Parameter: device
{
	local device="${1}"
	local STATUS=0
	mount "${device}1" "$CONFIG_DIR" &>/dev/null || true
	is_config_mounted && STATUS=1
	umount "$CONFIG_DIR" &>/dev/null || true
	# return code is the result of this expression
	[ 1 -eq "$STATUS" ] && return 0
	return 1
}


function is_config_mounted()
{
	mount | grep -q " ${CONFIG_DIR} " && [ -f "$CONFIG_MARKER" ]
}


function is_crypto_mounted()
{
	mount | grep -q " ${CRYPTO_DIR} "
}


function is_init_running()
{
	#ps -e | grep -q -E "$MKFS_DATA|$WIPE"
	# this line is good for the "at" stuff - see cryptobox.pl
	[ -n "$(at -l)" ]
}


function find_harddisk()
# look for the harddisk to be partitioned
{
	local dev=$(
		if is_config_mounted
		  then	config_get_value "device"
		  else	for a in $SCAN_DEVICES
			do	grep -q " `basename $a`$" /proc/partitions && echo "$a" && break
			    done
		fi )
	[ -z "$dev" ] && echo "no valid partition for initialisation found!" >>"$LOG_FILE"
	echo -n "$dev"
}


function mount_config()
{
	is_config_mounted && error_msg 3 "configuration directory ($CONFIG_DIR) is already mounted!"
	local device=$(
	    for a in $SCAN_DEVICES
		do	log_msg "Trying to load configuration from $a ..."
			config_mount_test "$a" && echo "$a" && break
		  done )
	if [ -n "$device" ] && mount "${device}1" "$CONFIG_DIR"
		then	log_msg "configuraton found on $device"
			config_set_value "device" "$device"
			return 0
		else	log_msg "failed to locate harddisk"
			return 1
	fi
}


function mount_crypto()
{
	is_crypto_mounted && echo "Das Crypto-Dateisystem ist bereits aktiv!" && return
	local device=`find_harddisk`
	[ -z "$device" ] && error_msg 4 'no valid harddisk found!'
	# passphrase is read from stdin
	log_msg "Mounting crypto partition ..."
	$CRYPTSETUP -h "$HASH" -c "$ALGO" create "`basename $CRYPTMAPPER_DEV`" "${device}2"
	if mount "$CRYPTMAPPER_DEV" "$CRYPTO_DIR"
		then	log_msg "Mount succeded - now starting samba ..."
			/etc/init.d/samba start
		else	log_msg "Mount failed - removing dev-mapper ..."
			dmsetup remove $(basename $CRYPTMAPPER_DEV)
			return 1
	fi
}


function umount_crypto()
{
	# do not break on error
	set +e
	if ps -e | grep -q " [sn]mbd$" 
		then	log_msg "Stopping samba ..."
			/etc/init.d/samba stop
			ps -e | grep -q " smbd$" && killall smbd
			ps -e | grep -q " nmbd$" && killall nmbd
			ps -e | grep -q " smbd$" && killall -9 smbd
			ps -e | grep -q " nmbd$" && killall -9 nmbd
	  fi
	if mount | grep -q " $CRYPTO_DIR "
		then	log_msg "Unmounting crypto partition ..."
			umount "$CRYPTO_DIR"
	  fi
	if [ -e "$CRYPTMAPPER_DEV" ]
		then	log_msg "Removing dev-mapper ..."
			$CRYPTSETUP remove $(basename $CRYPTMAPPER_DEV)
	  fi
	set -e
}

		
function init_cryptobox_part1()
# this is only the first part of initialisation that takes no time - good for a smooth web interface
{
	local device=`find_harddisk`
	[ -z "$device" ] && log_msg 'no valid harddisk found!' && return 1
	(
		log_msg "Initializing crypto partition on $device ..."
		umount_crypto || true
		mount | grep -q " $CONFIG_DIR " && umount "$CONFIG_DIR" || true
		initial_checks "$device" || return 1
		create_partitions "$device"
		create_config "$device"
	) >>"$LOG_FILE" 2>&1
	# the output of create_crypto may NOT be redirected - this would prevent cryptsetup from
	# reading the passphrase from stdin
	log_msg "Creating the crypto partition ..."
	create_crypto "$device"
}


function init_cryptobox_part2()
# some things to be done in the background
# these are the final steps of initialisation
# thuid must be changed at the first time, therfore it needs to be
# mounted
{
	mkfs_crypto
	mount "$CRYPTMAPPER_DEV" "$CRYPTO_DIR"
	chown $SAMBA_USER "$CRYPTO_DIR"
	umount_crypto
}


function init_cryptobox_complete()
{
	init_cryptobox_part1
	init_cryptobox_part2
}

### main ###

# set PATH because thttpd removes /sbin and /usr/sbin for cgis
export PATH=/usr/sbin:/usr/bin:/sbin:/bin


ACTION=help
[ $# -gt 0 ] && ACTION="$1"

case "$ACTION" in
	config-up )
		# die cruft option hilft vielleicht bei dem Fehler "interleaved files not (yet) supported"
		mount -o remount,cruft /
		if mount_config
		  then	echo "Cryptobox configuration successfully loaded"
		  else	error_msg 3 "Could not find a configuration partition!"
		 fi
		;;
	config-down )
		mount | grep -q " $CONFIG_DIR" && umount "$CONFIG_DIR"
		;;
	network-up )
		kudzu -s -q --class network
		conf_ip=$(config_get_value "ip")
		ifconfig $NET_IFACE "$conf_ip"
		log_msg "Configured $NET_IFACE for $conf_ip ..."
		echo "Configured network interface for $NET_IFACE: $conf_ip"
		log_msg "Starting the firewall ..."
		$FIREWALL_SCRIPT start
		# start stunnel
		if [ -f "$CERT_FILE" ] 
		   then	USE_CERT=$CERT_FILE
		   else USE_CERT=$CERT_TEMP
			$MAKE_CERT_SCRIPT "$CERT_TEMP" >>"$LOG_FILE" 2>&1
		  fi
		log_msg "Starting stunnel ..."
		stunnel -p "$USE_CERT" -r localhost:80 -d 443 \
			|| echo "$USE_CERT not found - not starting stunnel"
		# this ping allows other hosts to get the IP of
		# the box, in case of misconfiguration
		ping -b -c 1 $(ifconfig $NET_IFACE | grep Bcast | cut -d ":" -f 3 | cut -d " " -f 1) &>/dev/null
		;;
	network-down )
		log_msg "Stopping the firewall ..."
		$FIREWALL_SCRIPT stop
		log_msg "Stopping stunnel ..."
		killall stunnel
		log_msg "Shutting the network interface down ..."
		ifconfig $NET_IFACE down
		;;
	services-up )
		/etc/init.d/thttpd start
		;;
	services-down )
		/etc/init.d/samba stop
		/etc/init.d/thttpd stop
		;;
	box-init )
		# this is good for commandline only, as it takes a lot of time
		init_cryptobox_complete >>"$LOG_FILE" 2>&1
		;;
	box-init-fg )
		# only partitioning and configuration
		# this is nice for the web interface, as it is fast
		# output redirection does not work, as it prevents cryptsetup from asking
		# for a password
		init_cryptobox_part1
		;;
	box-init-bg )
		# do it in the background to provide a smoother web interface
		# messages and errors get written to $LOG_FILE
		init_cryptobox_part2 </dev/null >>"$LOG_FILE" 2>&1
		;;
	is_crypto_mounted )
		is_crypto_mounted
		;;
	is_config_mounted )
		is_config_mounted
		;;
	is_init_running )
		is_init_running
		;;
	crypto-mount )
		mount_crypto
		;;
	crypto-umount )
		umount_crypto
		;;
	set_config )
		[ $# -ne 3 ] && error_msg 7 "'set_config' requires two parameters"
		config_set_value "$2" "$3"
		;;
	get_config )
		[ $# -ne 2 ] && error_msg 6 "'get_config' requires exactly one parameter"
		config_get_value "$2"
		;;
	diskinfo )
		$SFDISK -L -q -l `find_harddisk`
		;;
	get_current_ip )
		get_current_ip
		;;
	is_harddisk_available )
		[ -z "$(find_harddisk)" ] && exit 1
		exit 0
		;;
	* )
		# TODO: update this!
		echo "Syntax: `basename $0` { mount_config | umount_config | init }"
		echo
		;;
  esac