Module tun_device 

VCL TUN Interface

Provides VCLTun — a TUN virtual network interface that captures IP packets from the OS network stack and injects them back after decryption/routing through a VCL tunnel.

How it works

Application
    ↓ (writes to TCP/UDP socket)
OS Network Stack
    ↓ (routes via routing table)
TUN interface (vcl0)
    ↓ (VCLTun::read_packet)
VCL Protocol (encrypt + send)
    ↓ (network)
Remote VCL (recv + decrypt)
    ↓ (VCLTun::write_packet)
TUN interface (remote vcl0)
    ↓ (inject into OS network stack)
Remote application

Requirements

• Linux only (TUN/TAP is a Linux kernel feature)
• Requires root or CAP_NET_ADMIN capability
• Does NOT work in WSL2 without custom kernel

Example

use vcl_protocol::tun_device::{VCLTun, TunConfig};

#[tokio::main]
async fn main() {
    let config = TunConfig {
        name: "vcl0".to_string(),
        address: "10.0.0.1".parse().unwrap(),
        destination: "10.0.0.2".parse().unwrap(),
        netmask: "255.255.255.0".parse().unwrap(),
        mtu: 1420,
    };

    let mut tun = VCLTun::create(config).unwrap();

    loop {
        let packet = tun.read_packet().await.unwrap();
        println!("Captured {} bytes", packet.len());
        // encrypt and send via VCL connection
    }
}

Structs

IpPacket

A parsed IP packet read from the TUN interface.

TunConfig

Configuration for a TUN virtual network interface.

VCLTun

A TUN virtual network interface for capturing and injecting IP packets.

Enums

IpVersion

IP protocol version detected in a packet.

Functions

ip_version

Returns the IP version of a raw packet, or None if empty.

is_ipv4

Check if a raw packet is IPv4.

is_ipv6

Check if a raw packet is IPv6.

parse_ip_packet

Parse raw bytes from a TUN read into an IpPacket.