无法从外部机器连接到 TCP Server

Question

我已经用 Rust 编写了一个基本的 TCP 服务器，但我无法从同一网络上的不同计算机访问它。这不是网络问题，因为我也写了一个类似的 Python TCP 服务器，并且测试客户端能够成功连接到该服务器。

use std::io::{Read, Write};
use std::net::{TcpListener, TcpStream};
use std::thread;
use std::str;

fn handle_read(mut stream: TcpStream) {
    let mut buf;
    // clear out the buffer so we don't send garbage
    buf = [0; 512];

    // Read and discard any data from the client since this is a read only server.
    let _ = match stream.read(&mut buf) {
        Err(e) => panic!("Got an error: {}", e),
        Ok(m) => m,
    };

    println!("Got some data");

    // Write back the response to the TCP stream
    match stream.write("This works!".as_bytes()) {
        Err(e) => panic!("Read-Server: Error writing to stream {}", e),
        Ok(_) => (),
    }

}

pub fn read_server() {
    // Create TCP server
    let listener = TcpListener::bind("127.0.0.1:6009").unwrap();
    println!("Read server listening on port 6009 started, ready to accept");

    // Wait for incoming connections and respond accordingly
    for stream in listener.incoming() {
        match stream {
            Err(_) => {
                println!("Got an error");
            }
            Ok(stream) => {

                println!("Received a connection");
                // Spawn a new thread to respond to the connection request
                thread::spawn(move || {
                    handle_read(stream);

                });

            }    
        }

    }
}

fn main() {
    read_server();
}

Answer 1

let listener = TcpListener::bind("127.0.0.1:6009").unwrap();

如果绑定到127.0.0.1:xxxx，则socket只能从localhost接口监听。要允许外部连接，请改为绑定到 0.0.0.0，以便它可以接受来自所有网络接口的连接。

let listener = TcpListener::bind("0.0.0.0:6009").unwrap();

详情请见Why would I bind on a different server than 127.0.0.1?。

---

顺便说一句，（1）

// not idiomatic
let _ = match stream.read(&mut buf) {
    Err(e) => panic!("Got an error: {}", e),
    Ok(m) => m,
};

您可以为此使用Result::expect。

// better
stream.read(&mut buf).expect("Got an error");

(2)

// not idiomatic
match stream.write("This works!".as_bytes()) {
    Err(e) => panic!("Read-Server: Error writing to stream {}", e),
    Ok(_) => (),
}

您可以简单地写成b"aaa"，而不是"aaa".as_bytes()。

// better
stream.write(b"This works!").expect("Read-Server: Error writing to stream");