#! /bin/sh
# SPDX-License-Identifier: GPL-2.0-or-later
#
# detect wrong shell versions
#
if ! ( printf "\n" | read -u 0 2>/dev/null ); then
	echo "wrong shell interpreter" 1>&2
	exit 1
fi
#
# file to transfer to the router
#
filename="$1"
#
# some constants to be changed, if needed
#
box_ip=${2:-192.168.178.1}
limit_memory=${3:-1}
box_port=21
box_user=adam2
box_pass=adam2
passive_ftp="P@SW"
[ ${#TMP} -eq 0 ] && TMP=/tmp
tmpdir=$TMP/tmp_$(date +%s)_$$
writefifo=$tmpdir/write
readfifo=$tmpdir/read
storefifo=$tmpdir/store
outstream=7
instream=8
upstream=9
logstream=3
logfile=${EVA_LOG:-$0.log}
envfile=$tmpdir/env
startaddress=0x80000000
#
# helper functions
#
read_ftp_response()
{
	local line="   -" rc=0 instream="$1" log="$2"
	while read -u $instream -r line; do
		[ ! -z "$log" ] && echo "$line" >&$log
		[ "${line:3:1}" != "-" ] && break
	done
	rc=$?
	echo "$line"
	return $rc
}
write_ftp_command()
{
	local outstream="$2" cmd="$1" log="$3"
	[ ! -z "$log" ] && echo "$cmd" >&$log
	echo "$cmd" >&$outstream
}
login_to_box()
{
	local instream="$1" outstream="$2" log="$3" lines=0
	write_ftp_command "USER $box_user" $outstream $log
	while [ $lines -lt 10 ]; do
		line="$(read_ftp_response $instream $log)"
		ec=${line:0:3}
		if [ x$ec == x331 ]; then
			write_ftp_command "PASS $box_pass" $outstream $log
		else
			if [ x$ec == x230 ]; then
				return 0
			elif [ x$ec == x530 ]; then
				return 1
			fi
		fi
		lines=$(( lines++ ))
	done
}
get_environment()
{
	local instream="$1" outstream="$2" log="$3" lines=0
	write_ftp_command "TYPE I" $outstream $log
	line="$(read_ftp_response $instream $log)"
	ec=${line:0:3}
	if [ x$ec != x200 ]; then
		return 1
	fi
	write_ftp_command "MEDIA SDRAM" $outstream $log
	line="$(read_ftp_response $instream $log)"
	ec=${line:0:3}
	if [ x$ec != x200 ]; then
		return 1
	fi
	write_ftp_command "$passive_ftp" $outstream $log
	line="$(read_ftp_response $instream $log)"
	ec=${line:0:3}
	if [ x$ec == x227 ]; then
		data_conn=$(echo $line | sed -n -e 's/.*(\([0-9]*\),\([0-9]*\),\([0-9]*\),\([0-9]*\),\([0-9]*\),\([0-9]*\)).*/data_ip=\1.\2.\3.\4 data_port=\$(( \5 * 256 + \6 ))/p')
		if [ ${#data_conn} -eq 0 ]; then
			return 1
		fi
		eval "$data_conn"
		nc -d -w 60 $data_ip $data_port >$envfile &
		data_connection=$!
		sleep 1
		write_ftp_command "RETR env" $outstream $log
		line="$(read_ftp_response $instream $log)"
		ec=${line:0:3}
		if [ x$ec == x150 ]; then
			line="$(read_ftp_response $instream $log)"
			ec=${line:0:3}
			if [ x$ec == x226 ]; then
				if [ -d /proc/$data_connection ]; then
					kill $data_connection 2>/dev/null &
					wait $data_connection 2>/dev/null
				fi
				data_connection=""
				echo $envfile
				return 0
			fi
		else
			return 1
		fi
	else
		return 1
	fi
}
upload_image()
{
	local instream="$1" outstream="$2" log="$3" file="$4" memsize="$5" startaddr="$6" endaddr="$7"
	eval "exec $upstream<>$storefifo"
	if [ $? -ne 0 ]; then
		return 1
	fi
	write_ftp_command "SETENV memsize $memsize" $outstream $logstream
	line="$(read_ftp_response $instream $log)"
	ec=${line:0:3}
	if [ x$ec != x200 ]; then
		eval "exec $upstream>&-"
		rm $storefifo
		return 1
	fi
	write_ftp_command "SETENV kernel_args_tmp mtdram1=$startaddr,$endaddr" $outstream $logstream
	line="$(read_ftp_response $instream $log)"
	ec=${line:0:3}
	if [ x$ec != x200 ]; then
		eval "exec $upstream>&-"
		rm $storefifo
		return 1
	fi
	write_ftp_command "TYPE I" $outstream $log
	line="$(read_ftp_response $instream $log)"
	ec=${line:0:3}
	if [ x$ec != x200 ]; then
		eval "exec $upstream>&-"
		rm $storefifo
		return 1
	fi
	write_ftp_command "MEDIA SDRAM" $outstream $log
	line="$(read_ftp_response $instream $log)"
	ec=${line:0:3}
	if [ x$ec != x200 ]; then
		eval "exec $upstream>&-"
		rm $storefifo
		return 1
	fi
	write_ftp_command "$passive_ftp" $outstream $log
	line="$(read_ftp_response $instream $log)"
	ec=${line:0:3}
	if [ x$ec == x227 ]; then
		data_conn=$(echo $line | sed -n -e 's/.*(\([0-9]*\),\([0-9]*\),\([0-9]*\),\([0-9]*\),\([0-9]*\),\([0-9]*\)).*/data_ip=\1.\2.\3.\4 data_port=\$(( \5 * 256 + \6 ))/p')
		if [ ${#data_conn} -eq 0 ]; then
			eval "exec $upstream>&-"
			return 1
		fi
		eval "$data_conn"
		nc -w 3 $data_ip $data_port <&$upstream 2>/dev/null 1>&2 &
		data_connection=$!
		sleep 1
		write_ftp_command "STOR $startaddr $endaddr" $outstream $logstream
		line="$(read_ftp_response $instream $log)"
		ec=${line:0:3}
		if [ x$ec == x150 ]; then
			cat $file >$storefifo
			line="$(read_ftp_response $instream $log)"
			ec=${line:0:3}
			if [ x$ec == x226 ] || [ x$ec == x553 ]; then
				if [ -d /proc/$data_connection ]; then
					kill $data_connection 2>/dev/null &
					wait $data_connection 2>/dev/null
				fi
				data_connection=""
				eval "exec $upstream>&-"
				rm $storefifo
				return 0
			fi
			eval "exec $upstream>&-"
			rm $storefifo
			return 1
		else
			eval "exec $upstream>&-"
			rm $storefifo
			return 1
		fi
	else
		eval "exec $upstream>&-"
		rm $storefifo
		return 1
	fi
}
#
# check file size
#
if [ x$filename == x ]; then
	echo "Missing file name."
	exit 1
fi
filesize=$(wc -c <$filename)
if [ $? -ne 0 ]; then
	echo "Missing file '$filename'"
	exit 1
fi
#
# check, if "mkfifo" and "nc" are present and usable
#
mkfifo 2>/dev/null
if [ $? -eq 127 ]; then
	echo "Missing usable 'mkfifo' command."
	exit 1
fi
command -v nc 2>/dev/null 1>&2
if [ $? -ne 0 ]; then
	echo "Missing any 'nc' command, it's needed for network communication and the OpenBSD version is required."
	exit 1
fi
# there's no unique identity for the BSD version, so we check for GNU version here
nc -V 2>/dev/null | grep -q GNU
if [ $? -eq 0 ]; then
	echo "Found GNU version of 'nc' command, but the OpenBSD version is required."
	exit 1
fi
#
# build redirections for FTP with "nc"
#
mkdir -p $tmpdir
mkfifo $writefifo
rc=$?
if [ $rc -ne 0 ]; then
	echo "Error $rc creating write fifo $writefifo."
	rm -r $tmpdir
	exit 1
fi
mkfifo $readfifo
rc=$?
if [ $rc -ne 0 ]; then
	echo "Error $rc creating read fifo $readfifo."
	rm $writefifo
	rm -r $tmpdir
	exit 1
fi
mkfifo $storefifo
rc=$?
if [ $rc -ne 0 ]; then
	echo "Error $rc creating upload fifo $storefifo."
	rm $writefifo
	rm $readfifo
	rm -r $tmpdir
	exit 1
fi
eval "exec $outstream<>$writefifo"
rc=$?
if [ $rc -ne 0 ]; then
	echo "Error $rc connecting write fifo to output stream."
	rm $writefifo
	rm $readfifo
	rm $storefifo
	rm -r $tmpdir
	exit 1
fi
eval "exec $instream<>$readfifo"
rc=$?
if [ $rc -ne 0 ]; then
	echo "Error $rc connecting read fifo to input stream."
	eval "exec $outstream>&-"
	rm $writefifo
	rm $readfifo
	rm $storefifo
	rm -r $tmpdir
	exit 1
fi
eval "exec $logstream<>$logfile"
rc=$?
if [ $rc -ne 0 ]; then
	echo "Error $rc connecting log stream to log file."
	eval "exec $instream>&-"
	eval "exec $outstream>&-"
	rm $writefifo
	rm $readfifo
	rm $storefifo
	rm -r $tmpdir
	exit 1
fi
#
# now open a connection to the box
#
nc $box_ip $box_port <&$outstream >&$instream 2>/dev/null &
control_connection=$!
data_connection=""
line="$(read_ftp_response $instream $logstream)"
ec=${line:0:3}
if [ x$ec == x220 ]; then
	login_to_box $instream $outstream $logstream
	if [ $? -eq 0 ]; then
		write_ftp_command "SYST" $outstream $logstream
		line="$(read_ftp_response $instream $logstream)"
		ec=${line:0:3}
		if [ x$ec == x215 ]; then
			syst=$(echo "$line" | sed -n -e "s/.*\(AVM EVA\).*/\1/p")
			if [ ${#syst} -ne 0 ]; then
				echo "Found AVM bootloader: ${line:4}"
				environment=$(get_environment $instream $outstream $logstream)
				if [ $? -eq 0 ]; then
					hwrev=$(sed -n -e "s/^HWRevision *\(.*\)\r\$/\1/p" $environment)
					echo "Found hardware revision: $hwrev"
					memsize=$(sed -n -e "s/^memsize *\(.*\)\r\$/\1/p" $environment)
					echo "Memory size is $memsize $(printf "(%u MB)" $(( $memsize / 1024 / 1024 )))"
					[ "$limit_memory" = "1" ] && memsize=$(( 1024 * 1024 * 128 )) && echo "Memory size limited to 128 MB"
					echo "Image size is $(printf "0x%06x" $filesize) $(printf "(%u MB)" $(( filesize / 1024 / 1024 )))"
					setmemsize=$(printf "0x%08x" $(( memsize - filesize )))
					echo "Setting temporary memory size to: $setmemsize"
					imagestartaddr=$(printf "0x%08x" $(( startaddress + setmemsize )))
					imageendaddr=$(printf "0x%08x" $(( startaddress + memsize )))
					echo "Setting temporary kernel args to: mtdram1=$imagestartaddr,$imageendaddr"
					upload_image $instream $outstream $logstream $filename $setmemsize $imagestartaddr $imageendaddr
					if [ $? -eq 0 ]; then
						echo "Image uploaded to device."
					fi
				fi
			else
				echo "Unexpected system found: ${line:4}"
			fi
		fi
	else
		echo "Login failed."
	fi
else
	echo "Error connecting to FRITZ!Box boot loader."
fi
if [ ${#data_connection} -ne 0 ]; then
	if [ -d /proc/$data_connection ]; then
		kill $data_connection 2>/dev/null &
		wait $data_connection 2>/dev/null
	fi
fi
if [ ${#control_connection} -ne 0 ]; then
	if [ -d /proc/$control_connection ]; then
		kill $control_connection 2>/dev/null &
		wait $control_connection 2>/dev/null
	fi
fi
eval "exec $logstream>&-"
eval "exec $instream>&-"
eval "exec $outstream>&-"
rm $writefifo
rm $readfifo
rm -r $tmpdir
exit 1