Async TUN/TAP

Asynchronous allocation of TUN/TAP devices in Rust using async-std.

Getting Started

• Create a tun device using TunBuilder and read from it in a loop:

use async_std::os::unix::io::AsRawFd;
use async_std::prelude::*;
use async_std::task;
use async_tun::result::Result;
use async_tun::TunBuilder;

async fn async_main() -> Result<()> {
    let mut tun = TunBuilder::new()
        .name("")            // If name is empty, then it is set by kernel.
        .tap(false)          // false (default): TUN, true: TAP.
        .packet_info(false)  // false: IFF_NO_PI, default is true.
        .try_build()
        .await?;

    println!("tun created, name: {}, fd: {}", tun.name(), tun.as_raw_fd());

    loop {
        let mut buf = [0u8; 1024];
        let n = tun.read(&mut buf).await?;
        println!("reading {} bytes: {:?}", n, &buf[..n]);
    }
}

fn main() -> Result<()> {
    task::block_on(async_main())
}

• Run the code using sudo:

➜  sudo -E /path/to/cargo run

• Set up the device:

➜  sudo ip link set dev <tun-name> up
➜  sudo ip a add 10.0.0.1/24 dev <tun-name>

• Ping to read packets:

➜  ping 10.0.0.2

• Analyze the network traffic:

➜  sudo tshark -i <tun-name>

Supported Platforms

• Linux
• FreeBSD
• OpenBSD
• NetBSD
• Android
• OSX
• iOS
• Solaris
• Windows
• QNX

Supported Flags

• Tun
• Tap
• No Packet Info
• Multi-Queue
• Owner
• Group
• MTU
• Persistent