netstack-smoltcp 0.2.1

A netstack for the special purpose of turning packets from/to a TUN interface into TCP streams and UDP packets. It uses smoltcp-rs as the backend netstack.
Documentation
# Netstack Smoltcp

A netstack for the special purpose of turning packets from/to a TUN interface into TCP streams and UDP packets. It uses smoltcp-rs as the backend netstack.

[![Crates.io][crates-badge]][crates-url]
[![MIT licensed][mit-badge]][mit-url]
[![Apache licensed, Version 2.0][apache-badge]][apache-url]
[![Build Status][actions-badge]][actions-url]

[crates-badge]: https://img.shields.io/crates/v/netstack-smoltcp.svg
[crates-url]: https://crates.io/crates/netstack-smoltcp
[mit-badge]: https://img.shields.io/badge/license-MIT-blue.svg
[mit-url]: https://github.com/automesh-network/netstack-smoltcp/blob/master/LICENSE-MIT
[apache-badge]: https://img.shields.io/badge/license-APACHE2.0-blue.svg
[apache-url]: https://github.com/automesh-network/netstack-smoltcp/blob/master/LICENSE-APACHE
[actions-badge]: https://github.com/automesh-network/netstack-smoltcp/workflows/CI/badge.svg
[actions-url]: https://github.com/automesh-network/netstack-smoltcp/actions?query=workflow%3ACI+branch%3Amain

## Features

- Supports Future Send and non-Send, mostly pepole use Send.
- Supports ICMP protocol drive by TCP runner to use ICMP ping.
- Supports filtering packets by source and destination IP addresses.
- Can read IP packets from netstack, write IP packets to netstack.
- Can receive TcpStream from TcpListener exposed from netstack.
- Can receive UDP datagram from UdpSocket exposed from netstack.
- Implements popular future streaming traits and asynchronous IO traits:
    * TcpListener implements futures Stream/Sink trait
    * TcpStream implements tokio AsyncRead/AsyncWrite trait
    * UdpSocket(ReadHalf/WriteHalf) implements futures Stream/Sink trait.

## Platforms

This crate provides lightweight netstack support for Linux, iOS, macOS, Android and Windows.
Currently, it works on most targets, but mainly tested the popular platforms which includes:
- linux-amd64: x86_64-unknown-linux-gnu
- android-arm64: aarch64-linux-android
- android-amd64: x86_64-linux-android
- macos-amd64: x86_64-apple-darwin
- macos-arm64: aarch64-apple-darwin
- ios-arm64: aarch64-apple-ios
- windows-amd64: x86_64-pc-windows-msvc
- windows-arm64: aarch64-pc-windows-msvc

## Example

```rust
// let device = tun2::create_as_async(&cfg)?;
// let framed = device.into_framed();

let (stack, runner, udp_socket, tcp_listener) = netstack_smoltcp::StackBuilder::default()
    .stack_buffer_size(512)
    .tcp_buffer_size(4096)
    .enable_udp(true)
    .enable_tcp(true)
    .enable_icmp(true)
    .build()
    .unwrap();
let mut udp_socket = udp_socket.unwrap(); // udp enabled
let mut tcp_listener = tcp_listener.unwrap(); // tcp/icmp enabled
if let Some(runner) = runner {
    tokio::spawn(runner);
}

let (mut stack_sink, mut stack_stream) = stack.split();
let (mut tun_sink, mut tun_stream) = framed.split();

// Reads packet from stack and sends to TUN.
tokio::spawn(async move {
    while let Some(pkt) = stack_stream.next().await {
        if let Ok(pkt) = pkt {
            tun_sink.send(pkt).await.unwrap();
        }
    }
});

// Reads packet from TUN and sends to stack.
tokio::spawn(async move {
    while let Some(pkt) = tun_stream.next().await {
        if let Ok(pkt) = pkt {
            stack_sink.send(pkt).await.unwrap();
        }
    }
});

// Extracts TCP connections from stack and sends them to the dispatcher.
tokio::spawn(async move {
    handle_inbound_stream(tcp_listener).await;
});

// Receive and send UDP packets between netstack and NAT manager. The NAT
// manager would maintain UDP sessions and send them to the dispatcher.
tokio::spawn(async move {
    handle_inbound_datagram(udp_socket).await;
});
```

## License

This project is licensed under either of

 * Apache License, Version 2.0, ([LICENSE-APACHE]LICENSE-APACHE or
   https://www.apache.org/licenses/LICENSE-2.0)
 * MIT license ([LICENSE-MIT]LICENSE-MIT or
   https://opensource.org/licenses/MIT)

at your option.

### Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted
for inclusion in netstack-smoltcp by you, as defined in the Apache-2.0 license,
shall be dual licensed as above, without any additional terms or conditions.

## Inspired By

Special thanks to these amazing projects that inspired netstack-smoltcp (in no particular order):
- [shadowsocks-rust]https://github.com/shadowsocks/shadowsocks-rust/
- [netstack-lwip]https://github.com/eycorsican/netstack-lwip/
- [rust-tun-active]https://github.com/tun2proxy/rust-tun
- [rust-tun]https://github.com/meh/rust-tun/
- [smoltcp]https://github.com/smoltcp-rs/smoltcp