Crate l3_extract

Source
Expand description

This crate aim to provide a way to allow users manipulate TCP and UDP which is obtained from layer-3 protocol packet, like normal async TCP stream and async UDP socket.

This crate is based on smoltcp, which is a single threaded, serial and event driven userspace TCP network stack crate, but this crate allows users use TcpStream, UdpSocket and others concurrently.

§Notes:

In order to hide the smoltcp single threaded, serial and event driven implement detail, the TcpStream will use channel to communicate with the TcpStack, and to improve performance, TcpStream has an inner buffer to reduce channel send.

This crate put ease of use first, then performance, so it absolutely slower than kernel TCP network stack, also slower than use smoltcp with hand write event loop.

§Examples:

use std::net::Ipv4Addr;
use std::str::FromStr;
use futures_util::{AsyncRead, AsyncWrite, StreamExt, TryStreamExt};
use futures_util::stream::FuturesUnordered;
use futures_util::task::SpawnExt;
use smoltcp::wire::Ipv4Cidr;
use l3_extract::TcpStack;

async fn run() {
    let connection = create_layer3_connection();
    let (mut tcp_stack, mut tcp_acceptor, mut udp_acceptor) = TcpStack::builder()
        .ipv4_addr(Ipv4Cidr::from_str("192.168.100.10/24").unwrap())
        .ipv4_gateway(Ipv4Addr::new(192, 168, 100, 1))
        .build(connection).unwrap();
    let mut futs = FuturesUnordered::new();
    futs.spawn(async {
        tcp_stack.run().await.unwrap()
    }).unwrap();
    futs.spawn(async {
        let tcp_stream = tcp_acceptor.try_next().await.unwrap().unwrap();
        // do something with tcp_stream
    }).unwrap();
    futs.spawn(async {
        let udp_socket = udp_acceptor.try_next().await.unwrap().unwrap();
        // do something with udp_socket
    }).unwrap();

    futs.collect::<Vec<_>>().await;
}

async fn create_layer3_connection() -> impl AsyncRead + AsyncWrite + Unpin {
    // create a layer3 connection
}

Modules§

tcp_stack
TCP network stack

Structs§

Ipv4Address
A four-octet IPv4 address.
Ipv4Cidr
A specification of an IPv4 CIDR block, containing an address and a variable-length subnet masking prefix length.
Ipv6Address
A sixteen-octet IPv6 address.
Ipv6Cidr
A specification of an IPv6 CIDR block, containing an address and a variable-length subnet masking prefix length.
TcpAcceptor
A TCP socket acceptor, like std::net::TcpListener, but you will accept a client side TCP stream, not server side
TcpStack
TCP network stack
TcpStream
A TCP stream, like tokio/async-net TcpStream
UdpAcceptor
a UDP socket acceptor, like TcpAcceptor, but you will accept a client side UDP socket, not server side
UdpSocket
A UDP socket, like tokio/async-net UdpSocket