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]