tcp-udp

This repository contains a demonstration TCP and UDP packet communication in Rust using tokio.

In Action

Client view:

Server view:

Overview

The tcp_udp crate defines a Packet structure that can be serialized and deserialized for network transmission. It provides methods for sending and receiving packets over tokio::net::TcpStream and tokio::net::UdpSocket.

The main.rs example demonstrates a UDP server that:

1. Listens for incoming UDP packets.
2. Deserializes the received packets.
3. Prints the packet ID and payload.
4. Sends an "echo" packet back to the sender.
5. Sends a heartbeat message every 5 seconds.

Project Structure

• src/lib.rs: Defines the Packet struct and its associated methods for serialization, deserialization, and sending/receiving over TCP/UDP.
• src/main.rs: Contains the main application logic, implementing a UDP server.
• src/client.rs: a client for sending encrypted messages (Run with $ cargo run --bin client)

Packet Structure

The Packet struct has the following fields:

• id: A u16 representing the packet's identifier.
• payload: A Vec<u8> containing the packet's data.

Serialization and Deserialization

• serialize(): Converts a Packet into a byte vector. The format is [id (2 bytes)] + [payload].
• deserialize(): Converts a byte slice back into a Packet.

Network Operations

• send(&self, stream: &mut TcpStream): Asynchronously sends the packet over a TcpStream. The packet is prefixed with its total length (including ID and payload) as a u16.
• recv(stream: &mut TcpStream): Asynchronously receives a packet from a TcpStream. It first reads the packet length, then the ID, and finally the payload.

Getting Started

Prerequisites

• Rust and Cargo: If you don't have Rust installed, you can get it from rustup.rs.

Running the UDP Server Example

1. Clone the repository:

   git clone <repository_url>
   cd <repository_name>

2. Run the example:

   cargo run

   This will start the UDP server listening on 127.0.0.1:8080. You will see heartbeat messages in the console.

Testing the UDP Server

You can use a tool like netcat (or nc) or write a simple client to send UDP packets to the server.

Example using netcat:

Open another terminal and send a message:

echo -n -e "\x00\x01Hello" | nc -u 127.0.0.1 8080

• \x00\x01: Represents the 2-byte packet ID (here, 1 in big-endian).
• Hello: Is the payload.

The server will then print something

Rust Ecosystem

To update rust:

rustup self update

Then run:

rustup update

Then try:

cargo clean
cargo build
cargo run