From 9ebd4077eeb49bc3e257a8a08f3461c8f03baac7 Mon Sep 17 00:00:00 2001
From: Long Nguyen <nguyen_van_long@humancrest.co.jp>
Date: Fri, 5 Feb 2021 17:16:51 +0900
Subject: [PATCH] Support TCP port range limitation

---
 bin/server           |  68 ----------
 bin/server.js        |  94 ++++++++++++++
 lib/ClientManager.js | 140 ++++++++++----------
 lib/TunnelAgent.js   | 297 ++++++++++++++++++++++---------------------
 package.json         |  11 +-
 server.js            | 257 +++++++++++++++++++------------------
 yarn.lock            | 162 +++++++++++++++++++++--
 7 files changed, 602 insertions(+), 427 deletions(-)
 delete mode 100755 bin/server
 create mode 100755 bin/server.js

diff --git a/bin/server b/bin/server
deleted file mode 100755
index a6bba9d..0000000
--- a/bin/server
+++ /dev/null
@@ -1,68 +0,0 @@
-#!/usr/bin/env node -r esm
-
-import 'localenv';
-import optimist from 'optimist';
-
-import log from 'book';
-import Debug from 'debug';
-
-import CreateServer from '../server';
-
-const debug = Debug('localtunnel');
-
-const argv = optimist
-    .usage('Usage: $0 --port [num]')
-    .options('secure', {
-        default: false,
-        describe: 'use this flag to indicate proxy over https'
-    })
-    .options('port', {
-        default: '80',
-        describe: 'listen on this port for outside requests'
-    })
-    .options('address', {
-        default: '0.0.0.0',
-        describe: 'IP address to bind to'
-    })
-    .options('domain', {
-        describe: 'Specify the base domain name. This is optional if hosting localtunnel from a regular example.com domain. This is required if hosting a localtunnel server from a subdomain (i.e. lt.example.dom where clients will be client-app.lt.example.come)',
-    })
-    .options('max-sockets', {
-        default: 10,
-        describe: 'maximum number of tcp sockets each client is allowed to establish at one time (the tunnels)'
-    })
-    .argv;
-
-if (argv.help) {
-    optimist.showHelp();
-    process.exit();
-}
-
-const server = CreateServer({
-    max_tcp_sockets: argv['max-sockets'],
-    secure: argv.secure,
-    domain: argv.domain,
-});
-
-server.listen(argv.port, argv.address, () => {
-    debug('server listening on port: %d', server.address().port);
-});
-
-process.on('SIGINT', () => {
-    process.exit();
-});
-
-process.on('SIGTERM', () => {
-    process.exit();
-});
-
-process.on('uncaughtException', (err) => {
-    log.error(err);
-});
-
-process.on('unhandledRejection', (reason, promise) => {
-    log.error(reason);
-});
-
-// vim: ft=javascript
-
diff --git a/bin/server.js b/bin/server.js
new file mode 100755
index 0000000..20d8ed0
--- /dev/null
+++ b/bin/server.js
@@ -0,0 +1,94 @@
+import 'localenv';
+import yargs from 'yargs'
+import { hideBin } from 'yargs/helpers'
+import log from 'book';
+import Debug from 'debug';
+import CreateServer from '../server';
+
+const debug = Debug('localtunnel');
+
+const DEFAULT_MIN_PORT = 8000;
+const DEFAULT_MAX_PORT = 65535;
+
+const argv = yargs(hideBin(process.argv))
+  .usage('Usage: $0 <command> [option]')
+  .option('secure', {
+    alias: 's',
+    type: 'boolean',
+    default: false,
+    description: 'Use this flag to indicate proxy over https'
+  })
+  .option('port', {
+    alias: 'p',
+    type: 'number',
+    default: 80,
+    description: 'Listen on this port for outside requests'
+  })
+  .option('address', {
+    default: '0.0.0.0',
+    description: 'IP address to bind to'
+  })
+  .option('domain', {
+    type: 'string',
+    description: 'Specify the base domain name. This is optional if hosting localtunnel from a regular example.com domain. This is required if hosting a localtunnel server from a subdomain (i.e. lt.example.dom where clients will be client-app.lt.example.come)',
+  })
+  .option('max-sockets', {
+    default: 10,
+    type: 'count',
+    description: 'Maximum number of tcp sockets each client is allowed to establish at one time (the tunnels)'
+  })
+  .option('min-port', {
+    default: DEFAULT_MIN_PORT,
+    type: 'number',
+    description: 'The minimum number of TCP ports to use for the localtunnel clients connecting to the server.'
+  })
+  .option('max-port', {
+    default: DEFAULT_MAX_PORT,
+    type: 'number',
+    description: 'The maximum number of TCP ports to use for the localtunnel clients connecting to the server.'
+  })
+  .argv;
+
+const minPort = argv['min-port'];
+const maxPort = argv['max-port'];
+
+const { address, port, secure, domain, maxSockets } = argv;
+
+if (Number.isInteger(minPort) && minPort < DEFAULT_MIN_PORT) {
+  console.error(`min-port must be a number greater than ${DEFAULT_MIN_PORT}`);
+  process.exit();
+} else if (Number.isInteger(maxPort) && maxPort > DEFAULT_MAX_PORT) {
+  console.error(`max-port must be a number less than ${DEFAULT_MAX_PORT}`);
+  process.exit();
+} else if (minPort >= maxPort) {
+  console.error(`min-port must be less than min-port`);
+  process.exit();
+}
+
+const server = CreateServer({
+  maxTcpSockets: maxSockets,
+  secure,
+  domain,
+  minPort,
+  maxPort,
+});
+
+server.listen(port, address, () => {
+  debug('server listening on port: %d', server.address().port);
+});
+
+process.on('SIGINT', () => {
+  process.exit();
+});
+
+process.on('SIGTERM', () => {
+  process.exit();
+});
+
+process.on('uncaughtException', (err) => {
+  log.error(err);
+});
+
+process.on('unhandledRejection', (reason) => {
+  log.error(reason);
+});
diff --git a/lib/ClientManager.js b/lib/ClientManager.js
index e1a7838..ec48abe 100644
--- a/lib/ClientManager.js
+++ b/lib/ClientManager.js
@@ -8,89 +8,93 @@ import TunnelAgent from './TunnelAgent';
 //
 // A client is a "user session" established to service a remote localtunnel client
 class ClientManager {
-    constructor(opt) {
-        this.opt = opt || {};
+  constructor(opt) {
+    this.opt = opt || {};
 
-        // id -> client instance
-        this.clients = new Map();
+    // id -> client instance
+    this.clients = new Map();
 
-        // statistics
-        this.stats = {
-            tunnels: 0
-        };
+    // statistics
+    this.stats = {
+      tunnels: 0
+    };
 
-        this.debug = Debug('lt:ClientManager');
+    this.debug = Debug('lt:ClientManager');
 
-        // This is totally wrong :facepalm: this needs to be per-client...
-        this.graceTimeout = null;
+    // This is totally wrong :facepalm: this needs to be per-client...
+    this.graceTimeout = null;
+  }
+
+  // create a new tunnel with `id`
+  // if the id is already used, a random id is assigned
+  // if the tunnel could not be created, throws an error
+  async newClient(id) {
+    const clients = this.clients;
+    const stats = this.stats;
+
+    // can't ask for id already is use
+    if (clients[id]) {
+      id = hri.random();
     }
 
-    // create a new tunnel with `id`
-    // if the id is already used, a random id is assigned
-    // if the tunnel could not be created, throws an error
-    async newClient(id) {
-        const clients = this.clients;
-        const stats = this.stats;
+    const maxSockets = this.opt.maxTcpSockets;
+    const minPort = this.opt.minPort;
+    const maxPort = this.opt.maxPort;
+    const agent = new TunnelAgent({
+      clientId: id,
+      maxSockets: 10,
+      minPort,
+      maxPort
+    });
 
-        // can't ask for id already is use
-        if (clients[id]) {
-            id = hri.random();
-        }
+    const client = new Client({
+      id,
+      agent,
+    });
 
-        const maxSockets = this.opt.max_tcp_sockets;
-        const agent = new TunnelAgent({
-            clientId: id,
-            maxSockets: 10,
-        });
+    // add to clients map immediately
+    // avoiding races with other clients requesting same id
+    clients[id] = client;
 
-        const client = new Client({
-            id,
-            agent,
-        });
+    client.once('close', () => {
+      this.removeClient(id);
+    });
 
-        // add to clients map immediately
-        // avoiding races with other clients requesting same id
-        clients[id] = client;
-
-        client.once('close', () => {
-            this.removeClient(id);
-        });
-
-        // try/catch used here to remove client id
-        try {
-            const info = await agent.listen();
-            ++stats.tunnels;
-            return {
-                id: id,
-                port: info.port,
-                max_conn_count: maxSockets,
-            };
-        }
-        catch (err) {
-            this.removeClient(id);
-            // rethrow error for upstream to handle
-            throw err;
-        }
+    // try/catch used here to remove client id
+    try {
+      const info = await agent.listen();
+      ++stats.tunnels;
+      return {
+        id: id,
+        port: info.port,
+        max_conn_count: maxSockets,
+      };
     }
-
-    removeClient(id) {
-        this.debug('removing client: %s', id);
-        const client = this.clients[id];
-        if (!client) {
-            return;
-        }
-        --this.stats.tunnels;
-        delete this.clients[id];
-        client.close();
+    catch (err) {
+      this.removeClient(id);
+      // rethrow error for upstream to handle
+      throw err;
     }
+  }
 
-    hasClient(id) {
-        return !!this.clients[id];
+  removeClient(id) {
+    this.debug('removing client: %s', id);
+    const client = this.clients[id];
+    if (!client) {
+      return;
     }
+    --this.stats.tunnels;
+    delete this.clients[id];
+    client.close();
+  }
 
-    getClient(id) {
-        return this.clients[id];
-    }
+  hasClient(id) {
+    return !!this.clients[id];
+  }
+
+  getClient(id) {
+    return this.clients[id];
+  }
 }
 
 export default ClientManager;
diff --git a/lib/TunnelAgent.js b/lib/TunnelAgent.js
index efc2231..588309c 100644
--- a/lib/TunnelAgent.js
+++ b/lib/TunnelAgent.js
@@ -1,8 +1,8 @@
 import { Agent } from 'http';
 import net from 'net';
-import assert from 'assert';
 import log from 'book';
 import Debug from 'debug';
+import { getPort } from 'portfinder';
 
 const DEFAULT_MAX_SOCKETS = 10;
 
@@ -10,166 +10,175 @@ const DEFAULT_MAX_SOCKETS = 10;
 // A tunnel socket is a connection _from_ a client that will
 // service http requests. This agent is usable wherever one can use an http.Agent
 class TunnelAgent extends Agent {
-    constructor(options = {}) {
-        super({
-            keepAlive: true,
-            // only allow keepalive to hold on to one socket
-            // this prevents it from holding on to all the sockets so they can be used for upgrades
-            maxFreeSockets: 1,
+  constructor(options = {}) {
+    super({
+      keepAlive: true,
+      // only allow keepalive to hold on to one socket
+      // this prevents it from holding on to all the sockets so they can be used for upgrades
+      maxFreeSockets: 1,
+    });
+
+    // sockets we can hand out via createConnection
+    this.availableSockets = [];
+
+    // when a createConnection cannot return a socket, it goes into a queue
+    // once a socket is available it is handed out to the next callback
+    this.waitingCreateConn = [];
+
+    this.debug = Debug(`lt:TunnelAgent[${options.clientId}]`);
+
+    // track maximum allowed sockets
+    this.connectedSockets = 0;
+    this.maxTcpSockets = options.maxTcpSockets || DEFAULT_MAX_SOCKETS;
+
+    // Port range
+    this.minPort = options.minPort || 8000;
+    this.maxPort = options.maxPort || 65535;
+
+    // new tcp server to service requests for this client
+    this.server = net.createServer();
+
+    // flag to avoid double starts
+    this.started = false;
+    this.closed = false;
+  }
+
+  stats() {
+    return {
+      connectedSockets: this.connectedSockets,
+    };
+  }
+
+  listen() {
+    const server = this.server;
+    if (this.started) {
+      throw new Error('already started');
+    }
+    this.started = true;
+
+    server.on('close', this._onClose.bind(this));
+    server.on('connection', this._onConnection.bind(this));
+    server.on('error', (err) => {
+      // These errors happen from killed connections, we don't worry about them
+      if (err.code == 'ECONNRESET' || err.code == 'ETIMEDOUT') {
+        return;
+      }
+      log.error(err);
+    });
+
+    return new Promise((resolve, reject) => {
+      getPort({
+        port: this.minPort,    // minimum port
+        stopPort: this.maxPort // maximum port
+      }, (err, port) => {
+        if (err) {
+          reject(err);
+        }
+        server.listen(port, () => {
+          resolve({
+            // port for lt client tcp connections
+            port,
+          });
         });
+      });
+    });
+  }
 
-        // sockets we can hand out via createConnection
-        this.availableSockets = [];
+  _onClose() {
+    this.closed = true;
+    this.debug('closed tcp socket');
+    // flush any waiting connections
+    for (const conn of this.waitingCreateConn) {
+      conn(new Error('closed'), null);
+    }
+    this.waitingCreateConn = [];
+    this.emit('end');
+  }
 
-        // when a createConnection cannot return a socket, it goes into a queue
-        // once a socket is available it is handed out to the next callback
-        this.waitingCreateConn = [];
-
-        this.debug = Debug(`lt:TunnelAgent[${options.clientId}]`);
-
-        // track maximum allowed sockets
-        this.connectedSockets = 0;
-        this.maxTcpSockets = options.maxTcpSockets || DEFAULT_MAX_SOCKETS;
-
-        // new tcp server to service requests for this client
-        this.server = net.createServer();
-
-        // flag to avoid double starts
-        this.started = false;
-        this.closed = false;
+  // new socket connection from client for tunneling requests to client
+  _onConnection(socket) {
+    // no more socket connections allowed
+    if (this.connectedSockets >= this.maxTcpSockets) {
+      this.debug('no more sockets allowed');
+      socket.destroy();
+      return false;
     }
 
-    stats() {
-        return {
-            connectedSockets: this.connectedSockets,
-        };
+    socket.once('close', (hadError) => {
+      this.debug('closed socket (error: %s)', hadError);
+      this.connectedSockets -= 1;
+      // remove the socket from available list
+      const idx = this.availableSockets.indexOf(socket);
+      if (idx >= 0) {
+        this.availableSockets.splice(idx, 1);
+      }
+
+      this.debug('connected sockets: %s', this.connectedSockets);
+      if (this.connectedSockets <= 0) {
+        this.debug('all sockets disconnected');
+        this.emit('offline');
+      }
+    });
+
+    // close will be emitted after this
+    socket.once('error', (err) => {
+      // we do not log these errors, sessions can drop from clients for many reasons
+      // these are not actionable errors for our server
+      socket.destroy();
+    });
+
+    if (this.connectedSockets === 0) {
+      this.emit('online');
     }
 
-    listen() {
-        const server = this.server;
-        if (this.started) {
-            throw new Error('already started');
-        }
-        this.started = true;
+    this.connectedSockets += 1;
+    this.debug('new connection from: %s:%s', socket.address().address, socket.address().port);
 
-        server.on('close', this._onClose.bind(this));
-        server.on('connection', this._onConnection.bind(this));
-        server.on('error', (err) => {
-            // These errors happen from killed connections, we don't worry about them
-            if (err.code == 'ECONNRESET' || err.code == 'ETIMEDOUT') {
-                return;
-            }
-            log.error(err);
-        });
-
-        return new Promise((resolve) => {
-            server.listen(() => {
-                const port = server.address().port;
-                this.debug('tcp server listening on port: %d', port);
-
-                resolve({
-                    // port for lt client tcp connections
-                    port: port,
-                });
-            });
-        });
+    // if there are queued callbacks, give this socket now and don't queue into available
+    const fn = this.waitingCreateConn.shift();
+    if (fn) {
+      this.debug('giving socket to queued conn request');
+      setTimeout(() => {
+        fn(null, socket);
+      }, 0);
+      return;
     }
 
-    _onClose() {
-        this.closed = true;
-        this.debug('closed tcp socket');
-        // flush any waiting connections
-        for (const conn of this.waitingCreateConn) {
-            conn(new Error('closed'), null);
-        }
-        this.waitingCreateConn = [];
-        this.emit('end');
+    // make socket available for those waiting on sockets
+    this.availableSockets.push(socket);
+  }
+
+  // fetch a socket from the available socket pool for the agent
+  // if no socket is available, queue
+  // cb(err, socket)
+  createConnection(options, cb) {
+    if (this.closed) {
+      cb(new Error('closed'));
+      return;
     }
 
-    // new socket connection from client for tunneling requests to client
-    _onConnection(socket) {
-        // no more socket connections allowed
-        if (this.connectedSockets >= this.maxTcpSockets) {
-            this.debug('no more sockets allowed');
-            socket.destroy();
-            return false;
-        }
+    this.debug('create connection');
 
-        socket.once('close', (hadError) => {
-            this.debug('closed socket (error: %s)', hadError);
-            this.connectedSockets -= 1;
-            // remove the socket from available list
-            const idx = this.availableSockets.indexOf(socket);
-            if (idx >= 0) {
-                this.availableSockets.splice(idx, 1);
-            }
+    // socket is a tcp connection back to the user hosting the site
+    const sock = this.availableSockets.shift();
 
-            this.debug('connected sockets: %s', this.connectedSockets);
-            if (this.connectedSockets <= 0) {
-                this.debug('all sockets disconnected');
-                this.emit('offline');
-            }
-        });
-
-        // close will be emitted after this
-        socket.once('error', (err) => {
-            // we do not log these errors, sessions can drop from clients for many reasons
-            // these are not actionable errors for our server
-            socket.destroy();
-        });
-
-        if (this.connectedSockets === 0) {
-            this.emit('online');
-        }
-
-        this.connectedSockets += 1;
-        this.debug('new connection from: %s:%s', socket.address().address, socket.address().port);
-
-        // if there are queued callbacks, give this socket now and don't queue into available
-        const fn = this.waitingCreateConn.shift();
-        if (fn) {
-            this.debug('giving socket to queued conn request');
-            setTimeout(() => {
-                fn(null, socket);
-            }, 0);
-            return;
-        }
-
-        // make socket available for those waiting on sockets
-        this.availableSockets.push(socket);
+    // no available sockets
+    // wait until we have one
+    if (!sock) {
+      this.waitingCreateConn.push(cb);
+      this.debug('waiting connected: %s', this.connectedSockets);
+      this.debug('waiting available: %s', this.availableSockets.length);
+      return;
     }
 
-    // fetch a socket from the available socket pool for the agent
-    // if no socket is available, queue
-    // cb(err, socket)
-    createConnection(options, cb) {
-        if (this.closed) {
-            cb(new Error('closed'));
-            return;
-        }
+    this.debug('socket given');
+    cb(null, sock);
+  }
 
-        this.debug('create connection');
-
-        // socket is a tcp connection back to the user hosting the site
-        const sock = this.availableSockets.shift();
-
-        // no available sockets
-        // wait until we have one
-        if (!sock) {
-            this.waitingCreateConn.push(cb);
-            this.debug('waiting connected: %s', this.connectedSockets);
-            this.debug('waiting available: %s', this.availableSockets.length);
-            return;
-        }
-
-        this.debug('socket given');
-        cb(null, sock);
-    }
-
-    destroy() {
-        this.server.close();
-        super.destroy();
-    }
+  destroy() {
+    this.server.close();
+    super.destroy();
+  }
 }
 
 export default TunnelAgent;
diff --git a/package.json b/package.json
index 0693b8d..0f960fe 100644
--- a/package.json
+++ b/package.json
@@ -16,9 +16,10 @@
     "koa": "2.5.1",
     "koa-router": "7.4.0",
     "localenv": "0.2.2",
-    "optimist": "0.6.1",
+    "portfinder": "1.0.28",
     "pump": "3.0.0",
-    "tldjs": "2.3.1"
+    "tldjs": "2.3.1",
+    "yargs": "16.2.0"
   },
   "devDependencies": {
     "mocha": "5.1.1",
@@ -28,7 +29,7 @@
   },
   "scripts": {
     "test": "mocha --check-leaks --require esm './**/*.test.js'",
-    "start": "./bin/server",
-    "dev": "node-dev bin/server --port 3000"
+    "start": "node -r esm ./bin/server --port 3000",
+    "dev": "node-dev -r esm bin/server --port 3000 --domain http://localhost:3000"
   }
-}
+}
\ No newline at end of file
diff --git a/server.js b/server.js
index 21a4af6..87f0fe8 100644
--- a/server.js
+++ b/server.js
@@ -1,4 +1,3 @@
-import log from 'book';
 import Koa from 'koa';
 import tldjs from 'tldjs';
 import Debug from 'debug';
@@ -10,159 +9,159 @@ import ClientManager from './lib/ClientManager';
 
 const debug = Debug('localtunnel:server');
 
-export default function(opt) {
-    opt = opt || {};
+export default function (opt) {
+  opt = opt || {};
 
-    const validHosts = (opt.domain) ? [opt.domain] : undefined;
-    const myTldjs = tldjs.fromUserSettings({ validHosts });
-    const landingPage = opt.landing || 'https://localtunnel.github.io/www/';
+  const validHosts = (opt.domain) ? [opt.domain] : undefined;
+  const myTldjs = tldjs.fromUserSettings({ validHosts });
+  const landingPage = opt.landing || 'https://localtunnel.github.io/www/';
 
-    function GetClientIdFromHostname(hostname) {
-        return myTldjs.getSubdomain(hostname);
+  function GetClientIdFromHostname(hostname) {
+    return myTldjs.getSubdomain(hostname);
+  }
+
+  const manager = new ClientManager(opt);
+
+  const schema = opt.secure ? 'https' : 'http';
+
+  const app = new Koa();
+  const router = new Router();
+
+  router.get('/api/status', async (ctx, next) => {
+    const stats = manager.stats;
+    ctx.body = {
+      tunnels: stats.tunnels,
+      mem: process.memoryUsage(),
+    };
+  });
+
+  router.get('/api/tunnels/:id/status', async (ctx, next) => {
+    const clientId = ctx.params.id;
+    const client = manager.getClient(clientId);
+    if (!client) {
+      ctx.throw(404);
+      return;
     }
 
-    const manager = new ClientManager(opt);
+    const stats = client.stats();
+    ctx.body = {
+      connected_sockets: stats.connectedSockets,
+    };
+  });
 
-    const schema = opt.secure ? 'https' : 'http';
+  app.use(router.routes());
+  app.use(router.allowedMethods());
 
-    const app = new Koa();
-    const router = new Router();
+  // root endpoint
+  app.use(async (ctx, next) => {
+    const path = ctx.request.path;
 
-    router.get('/api/status', async (ctx, next) => {
-        const stats = manager.stats;
-        ctx.body = {
-            tunnels: stats.tunnels,
-            mem: process.memoryUsage(),
-        };
-    });
+    // skip anything not on the root path
+    if (path !== '/') {
+      await next();
+      return;
+    }
 
-    router.get('/api/tunnels/:id/status', async (ctx, next) => {
-        const clientId = ctx.params.id;
-        const client = manager.getClient(clientId);
-        if (!client) {
-            ctx.throw(404);
-            return;
-        }
+    const isNewClientRequest = ctx.query['new'] !== undefined;
+    if (isNewClientRequest) {
+      const reqId = hri.random();
+      debug('making new client with id %s', reqId);
+      const info = await manager.newClient(reqId);
 
-        const stats = client.stats();
-        ctx.body = {
-            connected_sockets: stats.connectedSockets,
-        };
-    });
+      const url = schema + '://' + info.id + '.' + ctx.request.host;
+      info.url = url;
+      ctx.body = info;
+      return;
+    }
 
-    app.use(router.routes());
-    app.use(router.allowedMethods());
+    // no new client request, send to landing page
+    ctx.redirect(landingPage);
+  });
 
-    // root endpoint
-    app.use(async (ctx, next) => {
-        const path = ctx.request.path;
+  // anything after the / path is a request for a specific client name
+  // This is a backwards compat feature
+  app.use(async (ctx, next) => {
+    const parts = ctx.request.path.split('/');
 
-        // skip anything not on the root path
-        if (path !== '/') {
-            await next();
-            return;
-        }
+    // any request with several layers of paths is not allowed
+    // rejects /foo/bar
+    // allow /foo
+    if (parts.length !== 2) {
+      await next();
+      return;
+    }
 
-        const isNewClientRequest = ctx.query['new'] !== undefined;
-        if (isNewClientRequest) {
-            const reqId = hri.random();
-            debug('making new client with id %s', reqId);
-            const info = await manager.newClient(reqId);
+    const reqId = parts[1];
 
-            const url = schema + '://' + info.id + '.' + ctx.request.host;
-            info.url = url;
-            ctx.body = info;
-            return;
-        }
+    // limit requested hostnames to 63 characters
+    if (! /^(?:[a-z0-9][a-z0-9\-]{4,63}[a-z0-9]|[a-z0-9]{4,63})$/.test(reqId)) {
+      const msg = 'Invalid subdomain. Subdomains must be lowercase and between 4 and 63 alphanumeric characters.';
+      ctx.status = 403;
+      ctx.body = {
+        message: msg,
+      };
+      return;
+    }
 
-        // no new client request, send to landing page
-        ctx.redirect(landingPage);
-    });
+    debug('making new client with id %s', reqId);
+    const info = await manager.newClient(reqId);
 
-    // anything after the / path is a request for a specific client name
-    // This is a backwards compat feature
-    app.use(async (ctx, next) => {
-        const parts = ctx.request.path.split('/');
+    const url = schema + '://' + info.id + '.' + ctx.request.host;
+    info.url = url;
+    ctx.body = info;
+    return;
+  });
 
-        // any request with several layers of paths is not allowed
-        // rejects /foo/bar
-        // allow /foo
-        if (parts.length !== 2) {
-            await next();
-            return;
-        }
+  const server = http.createServer();
 
-        const reqId = parts[1];
+  const appCallback = app.callback();
 
-        // limit requested hostnames to 63 characters
-        if (! /^(?:[a-z0-9][a-z0-9\-]{4,63}[a-z0-9]|[a-z0-9]{4,63})$/.test(reqId)) {
-            const msg = 'Invalid subdomain. Subdomains must be lowercase and between 4 and 63 alphanumeric characters.';
-            ctx.status = 403;
-            ctx.body = {
-                message: msg,
-            };
-            return;
-        }
+  server.on('request', (req, res) => {
+    // without a hostname, we won't know who the request is for
+    const hostname = req.headers.host;
+    if (!hostname) {
+      res.statusCode = 400;
+      res.end('Host header is required');
+      return;
+    }
 
-        debug('making new client with id %s', reqId);
-        const info = await manager.newClient(reqId);
+    const clientId = GetClientIdFromHostname(hostname);
+    if (!clientId) {
+      appCallback(req, res);
+      return;
+    }
 
-        const url = schema + '://' + info.id + '.' + ctx.request.host;
-        info.url = url;
-        ctx.body = info;
-        return;
-    });
+    const client = manager.getClient(clientId);
+    if (!client) {
+      res.statusCode = 404;
+      res.end('404');
+      return;
+    }
 
-    const server = http.createServer();
+    client.handleRequest(req, res);
+  });
 
-    const appCallback = app.callback();
+  server.on('upgrade', (req, socket, head) => {
+    const hostname = req.headers.host;
+    if (!hostname) {
+      socket.destroy();
+      return;
+    }
 
-    server.on('request', (req, res) => {
-        // without a hostname, we won't know who the request is for
-        const hostname = req.headers.host;
-        if (!hostname) {
-            res.statusCode = 400;
-            res.end('Host header is required');
-            return;
-        }
+    const clientId = GetClientIdFromHostname(hostname);
+    if (!clientId) {
+      socket.destroy();
+      return;
+    }
 
-        const clientId = GetClientIdFromHostname(hostname);
-        if (!clientId) {
-            appCallback(req, res);
-            return;
-        }
+    const client = manager.getClient(clientId);
+    if (!client) {
+      socket.destroy();
+      return;
+    }
 
-        const client = manager.getClient(clientId);
-        if (!client) {
-            res.statusCode = 404;
-            res.end('404');
-            return;
-        }
+    client.handleUpgrade(req, socket);
+  });
 
-        client.handleRequest(req, res);
-    });
-
-    server.on('upgrade', (req, socket, head) => {
-        const hostname = req.headers.host;
-        if (!hostname) {
-            socket.destroy();
-            return;
-        }
-
-        const clientId = GetClientIdFromHostname(hostname);
-        if (!clientId) {
-            socket.destroy();
-            return;
-        }
-
-        const client = manager.getClient(clientId);
-        if (!client) {
-            socket.destroy();
-            return;
-        }
-
-        client.handleUpgrade(req, socket);
-    });
-
-    return server;
+  return server;
 };
diff --git a/yarn.lock b/yarn.lock
index 9ad744b..a90d145 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -13,10 +13,22 @@ ansi-regex@^2.0.0:
   version "2.1.1"
   resolved "https://registry.yarnpkg.com/ansi-regex/-/ansi-regex-2.1.1.tgz#c3b33ab5ee360d86e0e628f0468ae7ef27d654df"
 
+ansi-regex@^5.0.0:
+  version "5.0.0"
+  resolved "https://registry.yarnpkg.com/ansi-regex/-/ansi-regex-5.0.0.tgz#388539f55179bf39339c81af30a654d69f87cb75"
+  integrity sha512-bY6fj56OUQ0hU1KjFNDQuJFezqKdrAyFdIevADiqrWHwSlbmBNMHp5ak2f40Pm8JTFyM2mqxkG6ngkHO11f/lg==
+
 ansi-styles@^2.2.1:
   version "2.2.1"
   resolved "https://registry.yarnpkg.com/ansi-styles/-/ansi-styles-2.2.1.tgz#b432dd3358b634cf75e1e4664368240533c1ddbe"
 
+ansi-styles@^4.0.0:
+  version "4.3.0"
+  resolved "https://registry.yarnpkg.com/ansi-styles/-/ansi-styles-4.3.0.tgz#edd803628ae71c04c85ae7a0906edad34b648937"
+  integrity sha512-zbB9rCJAT1rbjiVDb2hqKFHNYLxgtk8NURxZ3IZwD3F6NtxbXZQCnnSi1Lkx+IDohdPlFp222wVALIheZJQSEg==
+  dependencies:
+    color-convert "^2.0.1"
+
 ansicolors@~0.2.1:
   version "0.2.1"
   resolved "https://registry.yarnpkg.com/ansicolors/-/ansicolors-0.2.1.tgz#be089599097b74a5c9c4a84a0cdbcdb62bd87aef"
@@ -33,6 +45,13 @@ async-limiter@~1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/async-limiter/-/async-limiter-1.0.0.tgz#78faed8c3d074ab81f22b4e985d79e8738f720f8"
 
+async@^2.6.2:
+  version "2.6.3"
+  resolved "https://registry.yarnpkg.com/async/-/async-2.6.3.tgz#d72625e2344a3656e3a3ad4fa749fa83299d82ff"
+  integrity sha512-zflvls11DCy+dQWzTW2dzuilv8Z5X/pjfmZOWba6TNIVDm+2UDaJmXSOXlasHKfNBs8oo3M0aT50fDEWfKZjXg==
+  dependencies:
+    lodash "^4.17.14"
+
 asynckit@^0.4.0:
   version "0.4.0"
   resolved "https://registry.yarnpkg.com/asynckit/-/asynckit-0.4.0.tgz#c79ed97f7f34cb8f2ba1bc9790bcc366474b4b79"
@@ -103,10 +122,31 @@ cli-usage@^0.1.1:
     marked "^0.3.12"
     marked-terminal "^2.0.0"
 
+cliui@^7.0.2:
+  version "7.0.4"
+  resolved "https://registry.yarnpkg.com/cliui/-/cliui-7.0.4.tgz#a0265ee655476fc807aea9df3df8df7783808b4f"
+  integrity sha512-OcRE68cOsVMXp1Yvonl/fzkQOyjLSu/8bhPDfQt0e0/Eb283TKP20Fs2MqoPsr9SwA595rRCA+QMzYc9nBP+JQ==
+  dependencies:
+    string-width "^4.2.0"
+    strip-ansi "^6.0.0"
+    wrap-ansi "^7.0.0"
+
 co@^4.6.0:
   version "4.6.0"
   resolved "https://registry.yarnpkg.com/co/-/co-4.6.0.tgz#6ea6bdf3d853ae54ccb8e47bfa0bf3f9031fb184"
 
+color-convert@^2.0.1:
+  version "2.0.1"
+  resolved "https://registry.yarnpkg.com/color-convert/-/color-convert-2.0.1.tgz#72d3a68d598c9bdb3af2ad1e84f21d896abd4de3"
+  integrity sha512-RRECPsj7iu/xb5oKYcsFHSppFNnsj/52OVTRKb4zP5onXwVF3zVmmToNcOfGC+CRDpfK/U584fMg38ZHCaElKQ==
+  dependencies:
+    color-name "~1.1.4"
+
+color-name@~1.1.4:
+  version "1.1.4"
+  resolved "https://registry.yarnpkg.com/color-name/-/color-name-1.1.4.tgz#c2a09a87acbde69543de6f63fa3995c826c536a2"
+  integrity sha512-dOy+3AuW3a2wNbZHIuMZpTcgjGuLU/uBL/ubcZF9OXbDo8ff4O8yVp5Bf0efS8uEoYo5q4Fx7dY9OgQGXgAsQA==
+
 colors@1.0.3:
   version "1.0.3"
   resolved "https://registry.yarnpkg.com/colors/-/colors-1.0.3.tgz#0433f44d809680fdeb60ed260f1b0c262e82a40b"
@@ -179,6 +219,13 @@ debug@*, debug@3.1.0, debug@^3.1.0:
   dependencies:
     ms "2.0.0"
 
+debug@^3.1.1:
+  version "3.2.7"
+  resolved "https://registry.yarnpkg.com/debug/-/debug-3.2.7.tgz#72580b7e9145fb39b6676f9c5e5fb100b934179a"
+  integrity sha512-CFjzYYAi4ThfiQvizrFQevTTXHtnCqWfe7x1AhgEscTz6ZbLbfoLRLPugTQyBth6f8ZERVUSyWHFD/7Wu4t1XQ==
+  dependencies:
+    ms "^2.1.1"
+
 decamelize@^1.1.2:
   version "1.2.0"
   resolved "https://registry.yarnpkg.com/decamelize/-/decamelize-1.2.0.tgz#f6534d15148269b20352e7bee26f501f9a191290"
@@ -217,6 +264,11 @@ ee-first@1.1.1:
   version "1.1.1"
   resolved "https://registry.yarnpkg.com/ee-first/-/ee-first-1.1.1.tgz#590c61156b0ae2f4f0255732a158b266bc56b21d"
 
+emoji-regex@^8.0.0:
+  version "8.0.0"
+  resolved "https://registry.yarnpkg.com/emoji-regex/-/emoji-regex-8.0.0.tgz#e818fd69ce5ccfcb404594f842963bf53164cc37"
+  integrity sha512-MSjYzcWNOA0ewAHpz0MxpYFvwg6yjy1NG3xteoqz644VCo/RPgnr1/GGt+ic3iJTzQ8Eu3TdM14SawnVUmGE6A==
+
 end-of-stream@^1.1.0:
   version "1.4.1"
   resolved "https://registry.yarnpkg.com/end-of-stream/-/end-of-stream-1.4.1.tgz#ed29634d19baba463b6ce6b80a37213eab71ec43"
@@ -239,6 +291,11 @@ error-stack-parser@1.3.6:
   dependencies:
     stackframe "^0.3.1"
 
+escalade@^3.1.1:
+  version "3.1.1"
+  resolved "https://registry.yarnpkg.com/escalade/-/escalade-3.1.1.tgz#d8cfdc7000965c5a0174b4a82eaa5c0552742e40"
+  integrity sha512-k0er2gUkLf8O0zKJiAhmkTnJlTvINGv7ygDNPbeIsX/TJjGJZHuh9B2UxbsaEkmlEo9MfhrSzmhIlhRlI2GXnw==
+
 escape-html@~1.0.1:
   version "1.0.3"
   resolved "https://registry.yarnpkg.com/escape-html/-/escape-html-1.0.3.tgz#0258eae4d3d0c0974de1c169188ef0051d1d1988"
@@ -296,6 +353,11 @@ fs.realpath@^1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/fs.realpath/-/fs.realpath-1.0.0.tgz#1504ad2523158caa40db4a2787cb01411994ea4f"
 
+get-caller-file@^2.0.5:
+  version "2.0.5"
+  resolved "https://registry.yarnpkg.com/get-caller-file/-/get-caller-file-2.0.5.tgz#4f94412a82db32f36e3b0b9741f8a97feb031f7e"
+  integrity sha512-DyFP3BM/3YHTQOCUL/w0OZHR0lpKeGrxotcHWcqNEdnltqFwXVfhEBQ94eIo34AfQpo0rGki4cyIiftY06h2Fg==
+
 get-stdin@^4.0.1:
   version "4.0.1"
   resolved "https://registry.yarnpkg.com/get-stdin/-/get-stdin-4.0.1.tgz#b968c6b0a04384324902e8bf1a5df32579a450fe"
@@ -400,6 +462,11 @@ is-finite@^1.0.0:
   dependencies:
     number-is-nan "^1.0.0"
 
+is-fullwidth-code-point@^3.0.0:
+  version "3.0.0"
+  resolved "https://registry.yarnpkg.com/is-fullwidth-code-point/-/is-fullwidth-code-point-3.0.0.tgz#f116f8064fe90b3f7844a38997c0b75051269f1d"
+  integrity sha512-zymm5+u+sCsSWyD9qNaejV3DFvhCKclKdizYaJUuHA83RLjb7nSuGnddCHGv0hk+KY7BMAlsWeK4Ueg6EV6XQg==
+
 is-generator-function@^1.0.3:
   version "1.0.7"
   resolved "https://registry.yarnpkg.com/is-generator-function/-/is-generator-function-1.0.7.tgz#d2132e529bb0000a7f80794d4bdf5cd5e5813522"
@@ -586,6 +653,11 @@ lodash.toarray@^4.4.0:
   version "4.4.0"
   resolved "https://registry.yarnpkg.com/lodash.toarray/-/lodash.toarray-4.4.0.tgz#24c4bfcd6b2fba38bfd0594db1179d8e9b656561"
 
+lodash@^4.17.14:
+  version "4.17.20"
+  resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.20.tgz#b44a9b6297bcb698f1c51a3545a2b3b368d59c52"
+  integrity sha512-PlhdFcillOINfeV7Ni6oF1TAEayyZBoZ8bcshTHqOYJYlrqzRK5hagpagky5o4HfCzzd1TRkXPMFq6cKk9rGmA==
+
 loud-rejection@^1.0.0:
   version "1.6.0"
   resolved "https://registry.yarnpkg.com/loud-rejection/-/loud-rejection-1.6.0.tgz#5b46f80147edee578870f086d04821cf998e551f"
@@ -662,9 +734,10 @@ minimist@^1.1.1, minimist@^1.1.3:
   version "1.2.0"
   resolved "https://registry.yarnpkg.com/minimist/-/minimist-1.2.0.tgz#a35008b20f41383eec1fb914f4cd5df79a264284"
 
-minimist@~0.0.1:
-  version "0.0.10"
-  resolved "https://registry.yarnpkg.com/minimist/-/minimist-0.0.10.tgz#de3f98543dbf96082be48ad1a0c7cda836301dcf"
+minimist@^1.2.5:
+  version "1.2.5"
+  resolved "https://registry.yarnpkg.com/minimist/-/minimist-1.2.5.tgz#67d66014b66a6a8aaa0c083c5fd58df4e4e97602"
+  integrity sha512-FM9nNUYrRBAELZQT3xeZQ7fmMOBg6nWNmJKTcgsJeaLstP/UODVpGsr5OhXhhXg6f+qtJ8uiZ+PUxkDWcgIXLw==
 
 mkdirp@0.5.1:
   version "0.5.1"
@@ -672,6 +745,13 @@ mkdirp@0.5.1:
   dependencies:
     minimist "0.0.8"
 
+mkdirp@^0.5.5:
+  version "0.5.5"
+  resolved "https://registry.yarnpkg.com/mkdirp/-/mkdirp-0.5.5.tgz#d91cefd62d1436ca0f41620e251288d420099def"
+  integrity sha512-NKmAlESf6jMGym1++R0Ra7wvhV+wFW63FaSOFPwRahvea0gMUcGUhVeAg/0BC0wiv9ih5NYPB1Wn1UEI1/L+xQ==
+  dependencies:
+    minimist "^1.2.5"
+
 mocha@5.1.1:
   version "5.1.1"
   resolved "https://registry.yarnpkg.com/mocha/-/mocha-5.1.1.tgz#b774c75609dac05eb48f4d9ba1d827b97fde8a7b"
@@ -692,6 +772,11 @@ ms@2.0.0:
   version "2.0.0"
   resolved "https://registry.yarnpkg.com/ms/-/ms-2.0.0.tgz#5608aeadfc00be6c2901df5f9861788de0d597c8"
 
+ms@^2.1.1:
+  version "2.1.3"
+  resolved "https://registry.yarnpkg.com/ms/-/ms-2.1.3.tgz#574c8138ce1d2b5861f0b44579dbadd60c6615b2"
+  integrity sha512-6FlzubTLZG3J2a/NVCAleEhjzq5oxgHyaCU9yYXvcLsvoVaHJq/s5xXI6/XXP6tz7R9xAOtHnSO/tXtF3WRTlA==
+
 negotiator@0.6.1:
   version "0.6.1"
   resolved "https://registry.yarnpkg.com/negotiator/-/negotiator-0.6.1.tgz#2b327184e8992101177b28563fb5e7102acd0ca9"
@@ -766,13 +851,6 @@ only@0.0.2:
   version "0.0.2"
   resolved "https://registry.yarnpkg.com/only/-/only-0.0.2.tgz#2afde84d03e50b9a8edc444e30610a70295edfb4"
 
-optimist@0.6.1:
-  version "0.6.1"
-  resolved "https://registry.yarnpkg.com/optimist/-/optimist-0.6.1.tgz#da3ea74686fa21a19a111c326e90eb15a0196686"
-  dependencies:
-    minimist "~0.0.1"
-    wordwrap "~0.0.2"
-
 parse-json@^2.2.0:
   version "2.2.0"
   resolved "https://registry.yarnpkg.com/parse-json/-/parse-json-2.2.0.tgz#f480f40434ef80741f8469099f8dea18f55a4dc9"
@@ -825,6 +903,15 @@ pinkie@^2.0.0:
   version "2.0.4"
   resolved "https://registry.yarnpkg.com/pinkie/-/pinkie-2.0.4.tgz#72556b80cfa0d48a974e80e77248e80ed4f7f870"
 
+portfinder@1.0.28:
+  version "1.0.28"
+  resolved "https://registry.yarnpkg.com/portfinder/-/portfinder-1.0.28.tgz#67c4622852bd5374dd1dd900f779f53462fac778"
+  integrity sha512-Se+2isanIcEqf2XMHjyUKskczxbPH7dQnlMjXX6+dybayyHvAf/TCgyMRlzf/B6QDhAEFOGes0pzRo3by4AbMA==
+  dependencies:
+    async "^2.6.2"
+    debug "^3.1.1"
+    mkdirp "^0.5.5"
+
 process-nextick-args@~2.0.0:
   version "2.0.0"
   resolved "https://registry.yarnpkg.com/process-nextick-args/-/process-nextick-args-2.0.0.tgz#a37d732f4271b4ab1ad070d35508e8290788ffaa"
@@ -890,6 +977,11 @@ repeating@^2.0.0:
   dependencies:
     is-finite "^1.0.0"
 
+require-directory@^2.1.1:
+  version "2.1.1"
+  resolved "https://registry.yarnpkg.com/require-directory/-/require-directory-2.1.1.tgz#8c64ad5fd30dab1c976e2344ffe7f792a6a6df42"
+  integrity sha1-jGStX9MNqxyXbiNE/+f3kqam30I=
+
 resolve@^1.0.0:
   version "1.7.1"
   resolved "https://registry.yarnpkg.com/resolve/-/resolve-1.7.1.tgz#aadd656374fd298aee895bc026b8297418677fd3"
@@ -946,6 +1038,15 @@ stackframe@^0.3.1:
   version "1.5.0"
   resolved "https://registry.yarnpkg.com/statuses/-/statuses-1.5.0.tgz#161c7dac177659fd9811f43771fa99381478628c"
 
+string-width@^4.1.0, string-width@^4.2.0:
+  version "4.2.0"
+  resolved "https://registry.yarnpkg.com/string-width/-/string-width-4.2.0.tgz#952182c46cc7b2c313d1596e623992bd163b72b5"
+  integrity sha512-zUz5JD+tgqtuDjMhwIg5uFVV3dtqZ9yQJlZVfq4I01/K5Paj5UHj7VyrQOJvzawSVlKpObApbfD0Ed6yJc+1eg==
+  dependencies:
+    emoji-regex "^8.0.0"
+    is-fullwidth-code-point "^3.0.0"
+    strip-ansi "^6.0.0"
+
 string_decoder@~1.1.1:
   version "1.1.1"
   resolved "https://registry.yarnpkg.com/string_decoder/-/string_decoder-1.1.1.tgz#9cf1611ba62685d7030ae9e4ba34149c3af03fc8"
@@ -958,6 +1059,13 @@ strip-ansi@^3.0.0:
   dependencies:
     ansi-regex "^2.0.0"
 
+strip-ansi@^6.0.0:
+  version "6.0.0"
+  resolved "https://registry.yarnpkg.com/strip-ansi/-/strip-ansi-6.0.0.tgz#0b1571dd7669ccd4f3e06e14ef1eed26225ae532"
+  integrity sha512-AuvKTrTfQNYNIctbR1K/YGTR1756GycPsg7b9bdV9Duqur4gv6aKqHXah67Z8ImS7WEz5QVcOtlfW2rZEugt6w==
+  dependencies:
+    ansi-regex "^5.0.0"
+
 strip-bom@^2.0.0:
   version "2.0.0"
   resolved "https://registry.yarnpkg.com/strip-bom/-/strip-bom-2.0.0.tgz#6219a85616520491f35788bdbf1447a99c7e6b0e"
@@ -1044,9 +1152,14 @@ which@^1.0.5:
   dependencies:
     isexe "^2.0.0"
 
-wordwrap@~0.0.2:
-  version "0.0.3"
-  resolved "https://registry.yarnpkg.com/wordwrap/-/wordwrap-0.0.3.tgz#a3d5da6cd5c0bc0008d37234bbaf1bed63059107"
+wrap-ansi@^7.0.0:
+  version "7.0.0"
+  resolved "https://registry.yarnpkg.com/wrap-ansi/-/wrap-ansi-7.0.0.tgz#67e145cff510a6a6984bdf1152911d69d2eb9e43"
+  integrity sha512-YVGIj2kamLSTxw6NsZjoBxfSwsn0ycdesmc4p+Q21c5zPuZ1pl+NfxVdxPtdHvmNVOQ6XSYG4AUtyt/Fi7D16Q==
+  dependencies:
+    ansi-styles "^4.0.0"
+    string-width "^4.1.0"
+    strip-ansi "^6.0.0"
 
 wrappy@1:
   version "1.0.2"
@@ -1064,3 +1177,26 @@ xtend@~2.0.6:
   dependencies:
     is-object "~0.1.2"
     object-keys "~0.2.0"
+
+y18n@^5.0.5:
+  version "5.0.5"
+  resolved "https://registry.yarnpkg.com/y18n/-/y18n-5.0.5.tgz#8769ec08d03b1ea2df2500acef561743bbb9ab18"
+  integrity sha512-hsRUr4FFrvhhRH12wOdfs38Gy7k2FFzB9qgN9v3aLykRq0dRcdcpz5C9FxdS2NuhOrI/628b/KSTJ3rwHysYSg==
+
+yargs-parser@^20.2.2:
+  version "20.2.4"
+  resolved "https://registry.yarnpkg.com/yargs-parser/-/yargs-parser-20.2.4.tgz#b42890f14566796f85ae8e3a25290d205f154a54"
+  integrity sha512-WOkpgNhPTlE73h4VFAFsOnomJVaovO8VqLDzy5saChRBFQFBoMYirowyW+Q9HB4HFF4Z7VZTiG3iSzJJA29yRA==
+
+yargs@16.2.0:
+  version "16.2.0"
+  resolved "https://registry.yarnpkg.com/yargs/-/yargs-16.2.0.tgz#1c82bf0f6b6a66eafce7ef30e376f49a12477f66"
+  integrity sha512-D1mvvtDG0L5ft/jGWkLpG1+m0eQxOfaBvTNELraWj22wSVUMWxZUvYgJYcKh6jGGIkJFhH4IZPQhR4TKpc8mBw==
+  dependencies:
+    cliui "^7.0.2"
+    escalade "^3.1.1"
+    get-caller-file "^2.0.5"
+    require-directory "^2.1.1"
+    string-width "^4.2.0"
+    y18n "^5.0.5"
+    yargs-parser "^20.2.2"