proxy.js

var net = require('net');
var EventEmitter = require('events').EventEmitter;

var log = require('bookrc');
var debug = require('debug')('localtunnel-server');

var Proxy = function(opt, cb) {
    if (!(this instanceof Proxy)) {
        return new Proxy(opt, cb);
    }

    var self = this;

    self.sockets = [];
    self.waiting = [];

    var id = opt.id;

    // default max is 10
    var max_tcp_sockets = opt.max_tcp_sockets || 10;

    // new tcp server to service requests for this client
    var client_server = net.createServer();

    client_server.on('error', function(err) {
        if (err.code == 'ECONNRESET' || err.code == 'ETIMEDOUT') {
            return;
        }

        log.error(err);
    });

    // track initial user connection setup
    var conn_timeout;

    // user has 5 seconds to connect before their slot is given up
    function maybe_tcp_close() {
        clearTimeout(conn_timeout);
        conn_timeout = setTimeout(function() {

            // sometimes the server is already closed but the event has not fired?
            try {
                clearTimeout(conn_timeout);
                client_server.close();
            } catch (err) {
                cleanup();
            }
        }, 5000);
    }

    maybe_tcp_close();

    function cleanup() {
        debug('closed tcp socket for client(%s)', id);

        clearTimeout(conn_timeout);

        // clear waiting by ending responses, (requests?)
        self.waiting.forEach(function(waiting) {
            waiting(null);
        });

        self.emit('end');
    }

    // no longer accepting connections for this id
    client_server.on('close', cleanup);

    // new tcp connection from lt client
    client_server.on('connection', function(socket) {