#!/sbin/openrc-run

### tun2socks options
TUN="utun0"
ETH="eth0"
ETHGW="10.0.0.1"
TUNGW="240.0.0.1"
SOCKS="10.0.0.3:1080"
MONITOR="0.0.0.0:80"
HIJACKDNS=""
BACKENDDNS="1.2.4.8:53,1.1.1.1:53"
HOSTS="localhost=127.0.0.1"
OPTIONS="-loglevel warning -tunName $TUN -proxyServer $SOCKS -monitor -monitorAddr $MONITOR -fakeDNS -hosts $HOSTS -backendDNS $BACKENDDNS"

### openrc options
description="the tun2socks route process"
name=$RC_SVCNAME
pidfile="/var/run/$RC_SVCNAME.pid"
logfile="/var/log/$RC_SVCNAME.log"
command="/usr/local/bin/tun2socks"
command_args=$OPTIONS
command_user="root"
command_background="yes"

depend() {
    #after *
    before chronyd
    after firewall
    use dns
}

_set_dns() {
    option=$1
    case $option in
        0)
        einfo "DNS settings updated"
        [ -f /etc/resolv.conf.copy ] || mv /etc/resolv.conf /etc/resolv.conf.copy
        cat > /etc/resolv.conf << EOF
nameserver $TUNGW
EOF
        ;;
        1)
        einfo "DNS settings restored"
        cp -f /etc/resolv.conf.copy /etc/resolv.conf
        ;;
        *)
        return 0
        ;;
    esac
    eend $?
}

start_pre() {
    if [ "${RC_CMD}" = "restart" ]; then
        ip link delete $TUN 2> /dev/null
    fi

    # enable ip_forward
    einfo $(sysctl -w net.ipv4.ip_forward=1) && eend $?

    # create tun device
    ip tuntap add mode tun dev $TUN
    ip addr add $TUNGW/24 dev $TUN
    ip link set dev $TUN up
    einfo "tun device created: $TUN" && eend $?

    # change default gateway
    ip route del default 2> /dev/null
    ip route add default via $TUNGW dev $TUN

    # add to ip route
    #ip route add 1.1.1.1/32 via $ETHGW

    # DNS settings
    _set_dns 0
}

stop_post() {
    # disable ip_forward
    einfo $(sysctl -w net.ipv4.ip_forward=0) && eend $?

    # delete from ip route
    #ip route del 1.1.1.1/32 via $ETHGW

    # change default gateway
    # ip route del default
    ip route add default via $ETHGW dev $ETH 2> /dev/null

    # delete tun device
    #ip link set dev $TUN down
    #ip addr del $TUNGW/24 dev $TUN
    #ip tuntap del mode tun dev $TUN
    ip link delete $TUN 2> /dev/null
    einfo "tun device deleted: $TUN" && eend $?

    # DNS settings
    _set_dns 1
}

start() {
    ebegin "Starting $RC_SVCNAME"
    start-stop-daemon --start --quiet \
        --background --exec $command \
        --user $command_user \
        --make-pidfile --pidfile $pidfile \
        --stdout $logfile --stderr $logfile \
        -- $command_args
    eend $?
}

stop() {
    if [ "${RC_CMD}" = "restart" ]; then
        _pid=$(pgrep $RC_SVCNAME)
        if [ "$_pid" != "$(cat $pidfile)" ]; then
            echo $_pid > $pidfile
        fi
    fi

    ebegin "Stopping $RC_SVCNAME"
    start-stop-daemon --stop --quiet --exec "$command" \
        --pidfile "$pidfile"
    eend $?

    if [ "$RC_RUNLEVEL" = "shutdown" ]; then
        _pid=$(pgrep $RC_SVCNAME)
        if [ -n $_pid ]; then
            kill -9 $_pid > /dev/null 2>&1
        fi
        rm -rf $pidfile
    fi
}