# wintun-bindings

Safe rust idiomatic bindings for the Wintun C library: <https://wintun.net>

All features of the Wintun library are wrapped using pure rust types and functions to make
usage feel ergonomic.

[![Version](https://img.shields.io/crates/v/wintun-bindings.svg?style=flat)](https://crates.io/crates/wintun-bindings)
[![Documentation](https://img.shields.io/badge/docs-release-brightgreen.svg?style=flat)](https://docs.rs/wintun-bindings)
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[![License](https://img.shields.io/crates/l/wintun-bindings.svg?style=flat)](https://github.com/nulldotblack/wintun-bindings/blob/master/LICENSE)

## Usage

Inside your code load the wintun.dll signed driver file, downloaded from <https://wintun.net>,
using [`load`], [`load_from_path`] or [`load_from_library`].

Then either call [`Adapter::create`] or [`Adapter::open`] to obtain a wintun
adapter. Start a session with [`Adapter::start_session`].

## Example
```rust, no_run

//Must be run as Administrator because we create network adapters
//Load the wintun dll file so that we can call the underlying C functions
//Unsafe because we are loading an arbitrary dll file
let wintun = unsafe { wintun_bindings::load_from_path("path/to/wintun.dll") }
    .expect("Failed to load wintun dll");

//Try to open an adapter with the name "Demo"
let adapter = match wintun_bindings::Adapter::open(&wintun, "Demo") {
    Ok(a) => a,
    Err(_) => {
        //If loading failed (most likely it didn't exist), create a new one
        wintun_bindings::Adapter::create(&wintun, "Demo", "Example", None)
            .expect("Failed to create wintun adapter!")
    }
};
//Specify the size of the ring buffer the wintun driver should use.
let session = adapter.start_session(wintun_bindings::MAX_RING_CAPACITY).unwrap();

//Get a 20 byte packet from the ring buffer
let mut packet = session.allocate_send_packet(20).unwrap();
let bytes: &mut [u8] = packet.bytes_mut();
//Write IPV4 version and header length
bytes[0] = 0x40;

//Finish writing IP header
bytes[9] = 0x69;
bytes[10] = 0x04;
bytes[11] = 0x20;
//...

//Send the packet to wintun virtual adapter for processing by the system
session.send_packet(packet);

//Stop any readers blocking for data on other threads
//Only needed when a blocking reader is preventing shutdown Ie. it holds an Arc to the
//session, blocking it from being dropped
let _ = session.shutdown();

//the session is stopped on drop
//drop(session);

//drop(adapter)
//And the adapter closes its resources when dropped
```

See `examples/wireshark.rs` for a more complete example that writes received packets to a pcap
file.

## Features

- `panic_on_unsent_packets`: Panics if a send packet is dropped without being sent. Useful for
  debugging packet issues because unsent packets that are dropped without being sent hold up
  wintun's internal ring buffer.

- `verify_binary_signature`: Verifies the signature of the wintun dll file before loading it.

- `async`: Enables async support for the library.
  Just add `async` feature to your `Cargo.toml`:
  ```toml
  [dependencies]
  wintun-bindings = { version = "0.7", features = ["async"] }
  ```
  And simply transform your `Session` into an `AsyncSession`:
  ```rust, ignore
  // ...
  let session = adapter.start_session(MAX_RING_CAPACITY)?;
  let mut reader_session = AsyncSession::from(session.clone());
  let mut writer_session: AsyncSession = session.clone().into();
  // ...
  ```

License: MIT