MyDHCP

A basic DHCP client written in Rust.

🚀 Overview

mydhcp is a standalone DHCP client made build out of curiosity of how DHCP and low level networking works it only supports linux because it used AF_PACKET socket's for total control over what gets set.

⚙️ Features

mydhcp is intentionally minimal and only supports IPv4 DHCP on Linux. Current capabilities include:

• Completes the standard DHCP handshake:
  DHCPDISCOVER → DHCPOFFER → DHCPREQUEST → DHCPACK
• Automatically renews the lease based on the server-provided time
• Sends a DHCPRELEASE on SIGINT or panic (cleanup logic included)
• Configures received parameters using shell commands (for now)
  • IP address
  • Subnet mask
  • Gateway (via ip route add default)
  • DNS (via editing /etc/resolv.conf)

🫆 Security

The project tries to use Rust safely, but it does contain some unsafe code due to use of libc. Notably:

• ManualDrop is used in the keep_track method to manage lease state cleanup
• Care was taken, but memory safety is not guaranteed — especially in keep_track

If you're concerned about security, treat this as an educational reference, not production code.

💼 Usage

This project is primarily for learning and exploration. It's not production-ready and may contain memory safety bugs or rough edges.

You may find it useful as:

• A starting point for writing your own DHCP client

• A reference for low-level networking in Rust

• A personal experiment to study packet formats and system integration

🌐 Installation

For now you can only build from source with cargo.

git clone https://github.com/XFajk/mydhcp.git
cd mydhcp
cargo build --release

🏃‍➡️ Running

Before running, note:

• This is not a daemon (yet) — you'll need to daemonize it yourself if needed
• If you're using NetworkManager or systemd-resolved, stop them to avoid conflicts

You can use the setup_for_testing.sh script to configure your environment safely. Review what it does before running:

SET_FOR_TESTING=1 ./test-net.sh [SSID] [PASSWORD] [INTERFACE]
sudo RUST_LOG=info ./target/release/mydhcp [INTERFACE]

To clean up:

SET_FOR_TESTING=0 ./setup_for_testing.sh

📋 Documentation

You can view code-level documentation using:

cargo doc --open

📝 TODO

• Add full code documentation via docstrings
• Write unit tests where usefull
• Turn into a proper daemo
• Replace shell commands with Netlink API (for route + interface setup)
• Add support for IPv6