Linux script to allow certain IPs to bypass VPN

tunbypass.sh

#!/bin/bash

if [ "$EUID" -ne 0 ]; then
    echo "This script must be run as root."
    exit 1
fi

if [ "$#" -lt 1 ]; then
    echo "Usage: sudo tunbypass <add/del/list> [server_ip]"
    exit 1
fi

action="$1"
gateway=$(ip route | grep default | awk '{print $3}')
default_interface=$(ip route | grep default | awk '{print $5}')

if [ "$action" == "list" ]; then
    echo "Bypassed Server IPs:"
    ip route | grep "via $gateway" | grep "metric 10" | awk '{print $1}'
    exit 0
fi

if [ "$#" -ne 2 ]; then
    echo "Usage: sudo tunbypass <add/del/list> [server_ip]"
    exit 1
fi

server_ip="$2"

if [ "$action" == "add" ]; then
    sudo ip route add "$server_ip" via "$gateway" dev "$default_interface" metric 10
    echo "Added bypass for $server_ip."
elif [ "$action" == "del" ]; then
    sudo ip route del "$server_ip" via "$gateway" dev "$default_interface" metric 10
    echo "Removed bypass for $server_ip."
else
    echo "Invalid action. Use 'add', 'del', or 'list'."
    exit 1
fi