linux-kernel-route-adder

A C utility to add static routes to the Linux kernel's Forwarding Information Base (FIB) using the Netlink protocol.

Linux FIB Route Adder

A lightweight C-based utility to add static routes to the Linux kernel's Forwarding Information Base (FIB) using the Netlink protocol.

Features

• Supports adding routes to both subnets and individual IP addresses.
• Communicates directly with the kernel's FIB via Netlink.
• Robust error handling and input validation.

Requirements

• Linux-based operating system.
• GCC or a compatible C compiler.

How to Build

Clone the repository and compile the source code:

git clone https://github.com/Liuboshenko/linux-kernel-route-adder.git
cd linux-fib-route-adder
make

# OR
git clone https://github.com/Liuboshenko/linux-kernel-route-adder.git
cd linux-fib-route-adder/src
gcc -o add_route main.c add_route.c -Wall

Usage

Run the utility with superuser privileges:

sudo ./add_route <DEST_IP/Prefix> <GATEWAY_IP> <INTERFACE>

For more details, see the Usage Guide.

Examples

Add a route to a subnet:

sudo ./add_route 192.168.128.0/24 192.168.100.1 eth0

Add a route to a single IP address:

sudo ./add_route 192.168.128.128/32 192.168.100.1 eth0

Explanation of Parameters

• <DEST_IP/Prefix>: The destination network or IP address with the prefix length (e.g., 192.168.128.0/24 for a subnet, 192.168.128.128/32 for a single address).
• <GATEWAY_IP>: The gateway IP address through which the route is accessible.
• <INTERFACE>: The name of the network interface (e.g., eth0, wlan0).

Documentation

• Usage Guide: Detailed instructions and advanced examples.
• Contributing Guide: Guidelines for contributing to this project.
• Design Document: Technical details and design decisions.

Error Handling

• The program validates the input parameters and ensures compatibility with the kernel routing table.
• If the route cannot be added, an error message will specify the cause (e.g., "Invalid argument").

Contribution

Contributions are welcome! Feel free to open issues or submit pull requests.

License

This project is licensed under the MIT License. See the LICENSE file for details.