# init script functions library for desktop linux systems

ZAPRET_BASE=${ZAPRET_BASE:-/opt/zapret}
ZAPRET_RW=${ZAPRET_RW:-"$ZAPRET_BASE"}
ZAPRET_CONFIG=${ZAPRET_CONFIG:-"$ZAPRET_RW/config"}
. "$ZAPRET_CONFIG"
. "$ZAPRET_BASE/common/base.sh"
. "$ZAPRET_BASE/common/fwtype.sh"
. "$ZAPRET_BASE/common/linux_iphelper.sh"
. "$ZAPRET_BASE/common/ipt.sh"
. "$ZAPRET_BASE/common/nft.sh"
. "$ZAPRET_BASE/common/linux_fw.sh"
. "$ZAPRET_BASE/common/linux_daemons.sh"
. "$ZAPRET_BASE/common/list.sh"
. "$ZAPRET_BASE/common/custom.sh"
CUSTOM_DIR="$ZAPRET_RW/init.d/sysv"


user_exists()
{
	id -u $1 >/dev/null 2>/dev/null
}
useradd_compat()
{
	# $1 - username
	# skip for readonly systems
	[ -w "/etc" ] && {
		if exists useradd ; then
			useradd --no-create-home --system --shell /bin/false $1
		elif is_linked_to_busybox adduser ; then
			# some systems may miss nogroup group in /etc/group
			# adduser fails if it's absent and no group is specified
			addgroup nogroup 2>/dev/null
			# busybox has special adduser syntax
			adduser -S -H -D $1
		elif exists adduser; then
			adduser --no-create-home --system --disabled-login $1
		fi
	}
	user_exists $1
}
prepare_user()
{
	# $WS_USER is required to prevent redirection of the traffic originating from TPWS itself
	# otherwise infinite loop will occur
	# also its good idea not to run tpws as root
	user_exists $WS_USER || {
		# fallback to daemon if we cant add WS_USER
		useradd_compat $WS_USER || {
			for user in daemon nobody; do
				user_exists $user && {
					WS_USER=$user
					return 0
				}
			done
			return 1
		}
	}
}

# this complex user selection allows to survive in any locked/readonly/minimalistic environment
[ -n "$WS_USER" ] || WS_USER=tpws
if prepare_user; then
 USEROPT="--user=$WS_USER"
else
 WS_USER=1
 USEROPT="--uid $WS_USER:$WS_USER"
fi

PIDDIR=/var/run
IPSET_CR="$ZAPRET_BASE/ipset/create_ipset.sh"

[ -n "$DESYNC_MARK" ] || DESYNC_MARK=0x40000000
[ -n "$DESYNC_MARK_POSTNAT" ] || DESYNC_MARK_POSTNAT=0x20000000

[ -n "$QNUM" ] || QNUM=200
[ -n "$NFQWS" ] || NFQWS="$ZAPRET_BASE/nfq/nfqws"
NFQWS_OPT_BASE="$USEROPT --dpi-desync-fwmark=$DESYNC_MARK"

[ -n "$TPPORT" ] || TPPORT=988
[ -n "$TPPORT_SOCKS" ] || TPPORT_SOCKS=987
[ -n "$TPWS" ] || TPWS="$ZAPRET_BASE/tpws/tpws"
TPWS_LOCALHOST4=127.0.0.127

TPWS_OPT_BASE="$USEROPT"
TPWS_OPT_BASE4="--bind-addr=$TPWS_LOCALHOST4"
TPWS_OPT_BASE6="--bind-addr=::1"
TPWS_WAIT="--bind-wait-ifup=30 --bind-wait-ip=30"
TPWS_WAIT_SOCKS6="$TPWS_WAIT --bind-wait-ip-linklocal=30"
# first wait for lan to ifup, then wait for bind-wait-ip-linklocal seconds for link local address and bind-wait-ip for any ipv6 as the worst case
TPWS_OPT_BASE6_PRE="--bind-linklocal=prefer $TPWS_WAIT --bind-wait-ip-linklocal=3"

dnat6_target()
{
	_dnat6_target "$@"
}
set_route_localnet()
{
	_set_route_localnet $1 $IFACE_LAN
}

fw_nfqws_post4()
{
	_fw_nfqws_post4  $1 "$2" $3 "$IFACE_WAN"
}
fw_nfqws_post6()
{
	_fw_nfqws_post6  $1 "$2" $3 "${IFACE_WAN6:-$IFACE_WAN}"
}
fw_nfqws_pre4()
{
	_fw_nfqws_pre4  $1 "$2" $3 "$IFACE_WAN"
}
fw_nfqws_pre6()
{
	_fw_nfqws_pre6  $1 "$2" $3 "${IFACE_WAN6:-$IFACE_WAN}"
}
fw_tpws4()
{
	_fw_tpws4 $1 "$2" $3 "$IFACE_LAN" "$IFACE_WAN"
}
fw_tpws6()
{
	_fw_tpws6 $1 "$2" $3 "$IFACE_LAN" "${IFACE_WAN6:-$IFACE_WAN}"
}
nft_fw_tpws4()
{
	_nft_fw_tpws4 "$1" $2 "$IFACE_WAN"
}
nft_fw_tpws6()
{
	_nft_fw_tpws6 "$1" $2 "$IFACE_LAN" "${IFACE_WAN6:-$IFACE_WAN}"
}
nft_fw_nfqws_post4()
{
	_nft_fw_nfqws_post4 "$1" $2 "$IFACE_WAN"
}
nft_fw_nfqws_post6()
{
	_nft_fw_nfqws_post6 "$1" $2 "${IFACE_WAN6:-$IFACE_WAN}"
}
nft_fw_nfqws_pre4()
{
	_nft_fw_nfqws_pre4 "$1" $2 "$IFACE_WAN"
}
nft_fw_nfqws_pre6()
{
	_nft_fw_nfqws_pre6 "$1" $2 "${IFACE_WAN6:-$IFACE_WAN}"
}
nft_fill_ifsets_overload()
{
	nft_fill_ifsets "$IFACE_LAN" "$IFACE_WAN" "${IFACE_WAN6:-$IFACE_WAN}"
}


run_daemon()
{
	# $1 - daemon number : 1,2,3,...
	# $2 - daemon
	# $3 - daemon args
	# use $PIDDIR/$DAEMONBASE$1.pid as pidfile

	local DAEMONBASE="$(basename "$2")"
	local PID= PIDFILE=$PIDDIR/$DAEMONBASE$1.pid
	echo "Starting daemon $1: $2 $3"

	[ -f "$PIDFILE" ] && {
		read PID <"$PIDFILE"
		[ -d "/proc/$PID" ] || PID=
	}

	if [ -n "$PID" ]; then
		echo already running
	else
		"$2" $3 >/dev/null &
		PID=$!
		if [ -n "$PID" ]; then
			echo $PID >$PIDFILE
		else
			echo could not start daemon $1 : $2 $3
			false
		fi
	fi
}
stop_daemon()
{
	# $1 - daemon number : 1,2,3,...
	# $2 - daemon
	# use $PIDDIR/$DAEMONBASE$1.pid as pidfile
	local DAEMONBASE="$(basename "$2")"
	local PID PIDFILE=$PIDDIR/$DAEMONBASE$1.pid
	echo "Stopping daemon $1: $2"
	if [ -f "$PIDFILE" ]; then
		read PID <"$PIDFILE"
		kill $PID
		rm -f "$PIDFILE"
	else
		echo no pidfile : $PIDFILE
	fi
}
do_daemon()
{
	# $1 - 1 - run, 0 - stop
	on_off_function run_daemon stop_daemon "$@"
}


do_tpws()
{
	# $1 : 1 - run, 0 - stop
	# $2 : daemon number
	# $3 : daemon args

	[ "$DISABLE_IPV4" = "1" ] && [ "$DISABLE_IPV6" = "1" ] && return 0

	local OPT="$TPWS_OPT_BASE"

	[ "$DISABLE_IPV4" = "1" ] || OPT="$OPT $TPWS_OPT_BASE4"
	[ "$DISABLE_IPV6" = "1" ] || {
		OPT="$OPT $TPWS_OPT_BASE6"
		for lan in $IFACE_LAN; do
			OPT="$OPT --bind-iface6=$lan $TPWS_OPT_BASE6_PRE"
		done
	}

	do_daemon $1 $2 "$TPWS" "$OPT $3"
}
do_tpws_socks()
{
	# $1 : 1 - run, 0 - stop
	# $2 : daemon number
	# $3 : daemon args

	[ "$DISABLE_IPV4" = "1" ] && [ "$DISABLE_IPV6" = "1" ] && return 0

	local opt="$TPWS_OPT_BASE --socks"

	tpws_apply_socks_binds opt

	do_daemon $1 $2 "$TPWS" "$opt $3"
}

do_nfqws()
{
	# $1 : 1 - run, 0 - stop
	# $2 : daemon number
	# $3 : daemon args

	do_daemon $1 $2 "$NFQWS" "$NFQWS_OPT_BASE $3"
}

tpws_apply_socks_binds()
{
	local o

	[ "$DISABLE_IPV4" = "1" ] || o="--bind-addr=127.0.0.1"
	[ "$DISABLE_IPV6" = "1" ] || o="$o --bind-addr=::1"
	
	for lan in $IFACE_LAN; do
	    [ "$DISABLE_IPV4" = "1" ] || o="$o --bind-iface4=$lan $TPWS_WAIT"
	    [ "$DISABLE_IPV6" = "1" ] || o="$o --bind-iface6=$lan --bind-linklocal=unwanted $TPWS_WAIT_SOCKS6"
	done
	eval $1="\"\$$1 $o\""
}


create_ipset()
{
	echo "Creating ip list table (firewall type $FWTYPE)"
	"$IPSET_CR" "$@"
}