PeerLink

PeerLink is a next-generation peer-to-peer VPN solution that creates a full-mesh network topology with a blockchain-based control plane powered by the Sui network. Connect all your devices seamlessly across the internet with a single command, enabling secure, decentralized networking without traditional VPN servers.

🌟 Key Features

• 🕸️ Full Mesh P2P VPN: Every device connects directly to every other device for optimal performance
• 🔗 Sui Blockchain Control Plane: Decentralized network management and peer discovery via Sui smart contracts
• 🌐 Exit Node Support: Route internet traffic through designated exit nodes for enhanced privacy
• 🔐 End-to-End Encryption: All traffic is encrypted using modern cryptographic protocols
• 📱 Cross-Platform: Supports Win/MacOS/Linux/FreeBSD/Android and X86/ARM/MIPS architectures
• ⚡ High Performance: Optimized for low latency and high throughput. Zero-copy throughout the entire link (TCP/UDP/WSS/WG protocols)
• 🛡️ NAT Traversal: Automatic NAT and firewall traversal for seamless connectivity supporting UDP and IPv6 traversal

🏗️ Architecture

PeerLink consists of two main components:

📦 Application Layer (/app)

• peerlink-core: The main VPN daemon that handles peer connections, routing, and traffic forwarding
• peerlink-cli: Command-line interface for network management and configuration
• Gateway Components: TCP/UDP proxies with NAT for internet routing via exit nodes
• Peer Management: OSPF-like routing protocol for optimal path selection

🔗 Smart Contract Layer (/contract)

• Sui Move Contracts: Blockchain-based network registry and peer discovery
• Network Management: Decentralized creation and management of VPN networks
• Exit Node Registry: Blockchain-managed exit node discovery and selection

🚀 Quick Start

Prerequisites

• Rust 1.89.0 or later
• Sui CLI tools (for blockchain features)
• Platform-specific network permissions (root/administrator access)

Installation

1. Clone the repository:

   git clone https://github.com/siphonelee/peerlink.git
   cd peerlink

2. Build the application:

   cd app
   cargo build --release

3. Install binaries:

   # Linux/macOS
   sudo cp target/release/peerlink-core /usr/local/bin/
   sudo cp target/release/peerlink-cli /usr/local/bin/
   
   # Or add to PATH
   export PATH=$PATH:$(pwd)/target/release

Basic Usage

1. Configure Sui blockchain credentials:

   cd app
   cp .sui.env.example .sui.env
   # Edit .sui.env with your Sui credentials

2. Create or join a network:

   # Create a new network
   peerlink-cli network create my-network secret123 -d "My private network"
   
   # Or join an existing network
   peerlink-core --network-name my-network --network-secret secret123

3. Start the VPN daemon:

   sudo peerlink-core --config-file config.toml

4. Manage exit nodes:

   # List available exit nodes
   peerlink-cli network exit-nodes my-network   

📖 Documentation

Network Management Commands

# List all networks
peerlink-cli network list

# Get network information
peerlink-cli network info <network-name>

# Get network secret (for authorized users)
peerlink-cli network secret <network-name>

# Exit node management
peerlink-cli network exit-nodes <network-name>
peerlink-cli network remove-exit-node <network-name> <peer-id>

Configuration

PeerLink uses TOML configuration files. See app/peerlink.toml.example for a complete configuration template.

Key configuration sections:

• Network settings: IP ranges, interface configuration
• Sui blockchain: Contract addresses and credentials
• Security: Encryption settings and access control
• Performance: Connection timeouts and buffer sizes

🔧 Development

Project Structure

peerlink/
├── app/                    # Main application code
│   ├── src/
│   │   ├── peerlink-core.rs   # VPN daemon
│   │   ├── peerlink-cli.rs    # CLI tool
│   │   ├── gateway/           # Traffic routing and NAT
│   │   ├── peers/             # Peer management and routing
│   │   ├── tunnel/            # Network tunneling protocols
│   │   └── chain_op/          # Blockchain operations
│   └── Cargo.toml
├── contract/               # Sui smart contracts
│   └── sui_move/
└── README.md

Building for Different Platforms

# macOS
cargo build --release --target x86_64-apple-darwin

# Linux
cargo build --release --target x86_64-unknown-linux-gnu

# Windows
cargo build --release --target x86_64-pc-windows-gnu

Running Tests

cd app
cargo test

🌐 How It Works

Peer Discovery

1. Networks are registered on the Sui blockchain
2. Peers discover each other through blockchain queries
3. Direct P2P connections are established using STUN/TURN protocols

Traffic Routing

1. Direct P2P: Traffic between peers flows directly through encrypted tunnels
2. Exit Node Routing: Internet traffic is routed through designated exit nodes
3. NAT Traversal: Automatic hole punching for connections behind NAT/firewalls

Security Model

• All peer communications are end-to-end encrypted
• Blockchain provides tamper-proof network configuration
• No central servers that can be compromised
• Exit nodes provide optional internet access without compromising peer privacy

🤝 Contributing

We welcome contributions!

Development Setup

1. Install Rust and Sui CLI tools
2. Fork and clone the repository
3. Create a feature branch
4. Make your changes and add tests
5. Submit a pull request