Rust tokio

#![feature(async_await)]

use tokio::{prelude::*, net::TcpListener};

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let addr = "0.0.0.0:12345".parse()?;
    let mut listener = TcpListener::bind(&addr).unwrap();

    loop {
        let (mut socket, _) = listener.accept().await?;
        tokio::spawn(async move {
            let mut buf = [0; 32 * 1024];
            loop {
                match socket.read(&mut buf).await {
                    Ok(0) | Err(_) => return,
                    Ok(read) => {
                        let mut bytes = &buf[0..read];
                        while let Some(clrf) = twoway::find_bytes(bytes, b"\r\n\r\n") {
                            if socket.write_all(b"HTTP/1.1 200 Ok\r\nContent-Length: 11\r\n\r\nHello World").await.is_err() { return }
                            bytes = &bytes[clrf + 4..];
                        }
                    }
                }
            }
        });
    }
}