node.jsでTCP/IPプロクシサーバー

シンプルなTCP/IP proxy serverです。
httpやsmtpなどを中継できます。

tcp_proxy.js

var util = require('util');
var net = require("net");
 
process.on("uncaughtException", function(e) {
	console.log(e);
});
 
if (process.argv.length != 5) {
	console.log("引数が正しく入力されていません:" + " <proxy_port> <target_host> <target_port>");
	console.log("example:node tcp_proxy.js 3000 www.google.com 80");
	process.exit();
}

var proxyPort = process.argv[2];
var targetHost = process.argv[3];
var targetPort = process.argv[4];
 
net.createServer(function (proxySocket) {
	var connected = false;
	var buffers = new Array();
	var targetSocket = new net.Socket();
	targetSocket.connect(parseInt(targetPort), targetHost, function() {
		connected = true;
		if (buffers.length > 0) {
			for (i = 0; i < buffers.length; i++) {
				console.log(buffers[i].toString());
				targetSocket.write(buffers[i]);
			}
		}
	});
 
	proxySocket.on("error", function (e) {
		targetSocket.end();
	});
	targetSocket.on("error", function (e) {
		console.log("targethostに接続できません " + targetHost + ', port ' + targetPort);
		proxySocket.end();
	});
 
	proxySocket.on("data", function (data) {
		console.log("send: "+data.toString()); //送信データ
		if (connected) {
			targetSocket.write(data);
		} else {
			buffers[buffers.length] = data;
		}
	});
	targetSocket.on("data", function(data) {
		console.log("rec: " + data.toString());  //受信データ
		proxySocket.write(data);
	});
 
	proxySocket.on("close", function(had_error) {
		targetSocket.end();
	});
	targetSocket.on("close", function(had_error) {
		proxySocket.end();
	});
 
}).listen(proxyPort)

使い方

$ node tcp_proxy.js [プロキシポート] [ターゲットホスト] [ターゲットポート]