在Express中侦听UDP消息 [英] Listen for UDP messages in Express

问题描述

我有一个使用Express的基本Node.js服务器.它需要能够处理TCP消息和UDP消息. TCP部分运行良好，但是现在我需要集成一种嗅探UDP消息的方法.我尝试使用dgram套接字将处理程序添加到过滤器堆栈中，但是没有成功.

I have a basic Node.js server using Express. It needs to be able to handle TCP messages as well as UDP messages. The TCP part is up and running great, but now I need to integrate a way to sniff out the UDP messages. I've tried adding a handler to the filter stack using a dgram socket, but it hasn't been successful.

const express = require('express');
const dgram = require('dgram');

// ...

const app = express();
const dgramSocket = dgram.createSocket('udp4');

// ...

app.use((req, res, next) => {
  dgramSocket.on('listening', () => {
    let addr = app.address();
    console.log(`Listening for UDP packets at ${addr.address}:${addr.port}`);
  });

  dgramSocket.on('error', (err) => {
    console.log(`UDP error: ${err.stack}`);
  });

  dgramSocket.on('message', (msg, rinfo) => {
    console.log(`Received UDP message`);
  });

  next();

}

// ...

app.set('port', 8080);

当我运行服务器时，其他所有东西都可以工作，但是我的dgram部分甚至都没有说他们在监听.我对Node不太熟悉，对UDP不太了解，所以我可能走错了路.有没有人能够将UDP消息传递与Express服务器集成?

When I run my server everything else works, but my dgram parts don't even say that they're listening. I'm not too familiar with Node and even less so with UDP, so I might be on the complete wrong track. Has anyone been able to integrate UDP messaging with an Express server?

推荐答案

好像我对端口的使用做了一些不幸的假设.事实证明，这可以非常简单地完成，但是您必须在两个不同的端口上进行监听:

Looks like I made some unfortunate assumptions about the usage of ports. It turns out this can be done quite simply, but you have to listen on two different ports:

const express = require('express');
const dgram = require('dgram');

// ...

const app = express();

// ... filter stack ...

const socket = dgram.createSocket('udp4');

socket.on('listening', () => {
  let addr = socket.address();
  console.log(`Listening for UDP packets at ${addr.address}:${addr.port}`);
});

socket.on('error', (err) => {
  console.error(`UDP error: ${err.stack}`);
});

socket.on('message', (msg, rinfo) => {
  console.log('Recieved UDP message');
});

app.set('port', 8080); // listen for TCP with Express
socket.bind(8082);     // listen for UDP with dgram

像魅力一样工作.

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