My Firewall Module

Table of Contents

• Introduction
• Features
• Prerequisites
• Installation
• Usage
• File Descriptions

Introduction

My Firewall Module is a Linux kernel module that provides a simple packet filtering and rate-limiting firewall functionality. It allows users to configure rules to either accept or drop incoming network packets based on the protocol (TCP/UDP) and optionally apply rate-limiting to prevent abuse.

This repository contains both the kernel module (my_firewall.c) and a userspace application (user_app_firewall.c) that communicates with the kernel module using custom IOCTL commands.

Features

• Packet filtering: The firewall can selectively accept or drop incoming TCP and UDP packets based on configurable rules.
• Rate-limiting: Users can enable rate-limiting to control the number of packets allowed from the same source IP within a specified time interval.
• Dynamic connection tracking: The kernel module automatically tracks active connections and removes expired connections to ensure efficient use of resources.

Prerequisites

• Linux Kernel Headers: Make sure you have the appropriate Linux kernel headers installed for your kernel version.
• GCC Compiler: The kernel module requires a C compiler to be installed on your system.

Installation

1. Clone this repository to your local machine.
2. Navigate to the repository directory containing the kernel module source code.

Usage

Building and Installing the Kernel Module

1. Open a terminal in the repository directory.
2. Run the following commands to build and install the kernel module:

   make
   sudo insmod my_firewall.ko

File Descriptions

• my_firewall.c: The main source code of the Linux kernel module implementing the firewall functionality.
• user_app_firewall.c: Source code for the userspace application that communicates with the kernel module using IOCTL commands.
• Device File Permissions The device file /dev/my_firewall_device is created with the following permissions:
• Read and Write: Owner
• Read: Group and Others