TCP Spy

TCP Spy is a simple node.js library to intercept raw TCP connections. I use it to reverse engineer TCP protocols ;-)

Install

You can install tcpspy using the Node Package Manager (npm):

npm install tcpspy

Simple example

var tcpspy = require('tcpspy');

var httpProxy = new TCPSpy(9000, "google.com", 80, "HTTP Proxy");
httpProxy.on('clientData', function (clientData) {
  console.log('clientData:', clientData);
});
httpProxy.on('serverData', function (serverData) {
  console.log('serverData:', serverData);
});
httpProxy.start();

console.log('Now go to http://localhost:9000 to test this out!');

Simple example using an object as parameters

var tcpspy = require('tcpspy');

var httpProxy = new TCPSpy({
  sourcePort: 9000,
  destinationIP: "google.com",
  destinationPort: 80,
  debugIdentifier: "HTTP Proxy"
});
httpProxy.on('clientData', function (clientData) {
  console.log('clientData:', clientData);
});
httpProxy.on('serverData', function (serverData) {
  console.log('serverData:', serverData);
});
httpProxy.start();

console.log('Now go to http://localhost:9000 to test this out!');

Note: if you leave out the debugIdentifier, no debugging info will be displayed.

Fancy example with colors

var tcpspy = require('tcpspy');

var colors = require('colors/safe');

if(!colors) console.log('Do "npm install https://github.com/grit96/colors.js" first.');

console.log(colors.red(' RED = client data'));
console.log(colors.blue('BLUE = server data'));


var httpProxy = new TCPSpy(9000, "google.com", 80, "HTTP Proxy");
httpProxy.on('clientData', function (clientData) {
  console.log(colors.red(clientData));
  console.log(colors.blue(clientData.toString()));
});
httpProxy.on('serverData', function (serverData) {
  console.log(colors.red(serverData));
  console.log(colors.blue(serverData.toString()));
});
httpProxy.start();

console.log('Now go to http://localhost:9000 to test this out!');