VPN UFW Kill Switch

#!/bin/bash

# https://github.com/renapoliveira/killswitch-for-openvpn
# https://askubuntu.com/questions/530088/ufw-for-openvpn

VPN_FILE=openvpn.ovpn
TUNNEL=tun0

INTERFACE=`ip addr | grep "state UP" | cut -d ":" -f 2 | cut -c 2- | head -n 1`
IP=`cat $VPN_FILE | grep "remote " | awk '{print $2}'`
PORT=`cat $VPN_FILE | grep "remote " | awk '{print $3}'`
PROTOCOL=`cat $VPN_FILE | grep "proto " | awk '{print $2}'`

echo "Using "$INTERFACE"->"$TUNNEL
echo "Connecting to "$IP":"$PORT" via "$PROTOCOL

sudo ufw --force reset
sudo ufw default deny incoming
sudo ufw default deny outgoing
sudo ufw allow out on $TUNNEL
sudo ufw allow out on $INTERFACE to any port 53,$PORT,1197 proto $PROTOCOL
sudo ufw enable
sudo ufw status verbose

sudo openvpn --config $VPN_FILE