TUN interfaces [](https://crates.io/crates/tun)  
==============
This crate allows the creation and usage of TUN interfaces, the aim is to make this cross-platform.
Usage
-----
First, add the following to your `Cargo.toml`:
```toml
[dependencies]
tun = "0.5"
```
Next, add this to your crate root:
```rust
extern crate tun;
```
If you want to use the TUN interface with mio/tokio, you need to enable the `async` feature:
```toml
[dependencies]
tun = { version = "0.5", features = ["async"] }
```
Example
-------
The following example creates and configures a TUN interface and starts reading
packets from it.
```rust
use std::io::Read;
extern crate tun;
fn main() {
let mut config = tun::Configuration::default();
config.address((10, 0, 0, 1))
.netmask((255, 255, 255, 0))
.up();
#[cfg(target_os = "linux")]
config.platform(|config| {
config.packet_information(true);
});
let mut dev = tun::create(&config).unwrap();
let mut buf = [0; 4096];
loop {
let amount = dev.read(&mut buf).unwrap();
println!("{:?}", &buf[0 .. amount]);
}
}
```
Platforms
=========
Not every platform is supported.
Linux
-----
You will need the `tun` module to be loaded and root is required to create
interfaces.
macOS
-----
It just werks, but you have to set up routing manually.
iOS
----
You can pass the file descriptor of the TUN device to `rust-tun` to create the interface.
Here is an example to create the TUN device on iOS and pass the `fd` to `rust-tun`:
```swift
// Swift
class PacketTunnelProvider: NEPacketTunnelProvider {
override func startTunnel(options: [String : NSObject]?, completionHandler: @escaping (Error?) -> Void) {
let tunnelNetworkSettings = createTunnelSettings() // Configure TUN address, DNS, mtu, routing...
setTunnelNetworkSettings(tunnelNetworkSettings) { [weak self] error in
let tunFd = self?.packetFlow.value(forKeyPath: "socket.fileDescriptor") as! Int32
DispatchQueue.global(qos: .default).async {
start_tun(tunFd)
}
completionHandler(nil)
}
}
}
```
```rust
#[no_mangle]
pub extern "C" fn start_tun(fd: std::os::raw::c_int) {
let mut rt = tokio::runtime::Runtime::new().unwrap();
rt.block_on(async {
let mut cfg = tun::Configuration::default();
cfg.raw_fd(fd);
let mut tun = tun::create_as_async(&cfg).unwrap();
let mut framed = tun.into_framed();
while let Some(packet) = framed.next().await {
...
}
});
}
```