VPN Kill Switch | ChromeOS or Linux | .sh or command line syntax

iptables_killswitch.sh

#! /bin/bash
#########################################################################
#####   VPN Kill Switch Linux
#########################################################################
#
# Set Varibles
vpn_ip=55.55.55.55
vpn_interface=tun0
#
sudo iptables -F
sudo iptables -P INPUT DROP 
sudo iptables -P FORWARD DROP 
sudo iptables -P OUTPUT DROP 
sudo iptables -A INPUT -i lo -j ACCEPT 
sudo iptables -A INPUT -s $vpn_ip -j ACCEPT 
sudo iptables -A INPUT -i $vpn_interface -j ACCEPT 
sudo iptables -A INPUT -j DROP 
sudo iptables -A OUTPUT -o lo -j ACCEPT 
sudo iptables -A OUTPUT -d $vpn_ip -j ACCEPT 
sudo iptables -A OUTPUT -o $vpn_interface -j ACCEPT 
sudo iptables -A OUTPUT -j DROP
sudo ip6tables -F