Async TUN/TAP

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

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;
use std::net::Ipv4Addr;

async fn async_main() -> Result<()> {
    let 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.
        .up()                // or set it up manually using `sudo ip link set <tun-name> up`.
        .try_build()         // or `.try_build_mq(queues)` for multi-queue support.
        .await?;

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

    let mut reader = tun.reader();
    let mut buf = [0u8; 1024];
    loop {
        let n = reader.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 the address of device (address and netmask could also be set using TunBuilder):

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

• Ping to read packets:

➜  ping 10.0.0.2

• Display devices and analyze the network traffic:

➜  ip tuntap
➜  sudo tshark -i <tun-name>

Supported Platforms

• Linux
• FreeBSD
• Android
• OSX
• iOS
• Windows

Examples

• read: reading from tun using async-std.
• read-mq: reading from multi-queue tun using async-std.
• read-tokio: reading from tun using tokio. It should be run with use-tokio feature.