skeletal structure for bootstrap.js
[henge/kiak.git] / router.js
index 2f0441a..2085e9b 100644 (file)
--- a/router.js
+++ b/router.js
  * @author    Ken Grimes
  * @version   0.0.1
  * @license   AGPL-3.0
- * @copyright jk software 2017
+ * @copyright Strapp.io
  */
-const fs = require('fs')
-
-module.exports = (opts) => {
-  const startHttpd = (listener) => {
-    if (opts['no-tls'])
-      return require('http').createServer(listener)
-    if (fs.existsSync(opts['ca-cert']))
-      
-  }
-  return {
-    httpd: startHttpd(),
-    wsd:   startWsd()
-  }
+
+const dlog = (msg) => console.log(msg)
+
+exports = {
+  /** Regular expression for valid routes
+   * @prop {Object.RegEx} validRoutes - matches valid route names
+   */
+  validRoutes: /[a-zA-Z][a-zA-Z0-9\-_]*/,
+
+  /** A map of routes
+   * @prop {Object.Map} routes - all the routes!
+   */
+  routes: {},
+
+  /** Parameters set on bootup (startHttpServer)
+   * @prop {string[2]} skelPage - html document split in twain for JS injection
+   * @prop {string} clientJS - jerverscripps to inject in skelPage for clients
+   * @prop {string} hostJS - jerverscripps for the hosts
+   * @prop {string} httpdRoot - a normalized path for http-servable files
+   * @prop {string} bindJail - jail bindings to this path
+   */
+  skelPage: undefined,
+  clientJS: undefined,
+  hostJS: undefined,
+  httpdRoot: undefined,
+  bindJail: undefined,
+
+  /** @func
+   * @summary Start main HTTP server
+   * @desc    starts up an HTTP or HTTPS server used for routing
+   * @arg     {Object} conf - object containing configuration properties
+   * @prop    {number|string} conf.port - local system port to bind to
+   * @prop    {string} conf.skelFile - location of the skeleton HTML page
+   * @prop    {string} conf.clientJS - client JS file
+   * @prop    {string} conf.hostJS - host JS file
+   * @prop    {string} [conf.httpdRoot] - root path of http-accessible files, if
+   *                                      undefined no files are accessible
+   * @prop    {Object} [conf.tls] - if present, startHttpServer will use tls
+   * @prop    {string} [conf.tls.certFile] - tls certificate file
+   * @prop    {string} [conf.tls.keyFile] - tls public key file
+   */
+  startHttpServer: function (conf) {
+    if ('httpd' in this)
+      throw new Error('httpd already running')
+    if (conf.tls == undefined)
+      this.httpd = require('http').createServer((req, res) =>
+                                                this.httpdListener(req, res))
+    else if (!('keyFile' in conf.tls) || !('certFile' in conf.tls))
+      throw new Error('HTTPS requires a valid key and cert')
+    else
+      this.syncReads([conf.tls.keyFile, conf.tls.certFile]).then((results) => {
+        Object.defineProperty(this, 'httpsOpts', {
+          value: {
+            key: results[conf.tls.keyFile],
+            cert: results[conf.tls.certFile]
+          }
+        })
+        this.httpd =
+          require('https').createServer(this.httpsOpts, (request,response) =>
+                                        this.httpdListener(request,response))
+          .listen(conf.port)
+      })
+    if (conf.httpdRoot) {
+      this.httpdRoot = require('path').normalize(conf.httpdRoot)
+      while (this.httpdRoot[this.httpdRoot.length - 1] == require('path').sep)
+        this.httpdRoot = this.httpdRoot.slice(0,-1)
+    }
+    this.syncReads([conf.skelFile, conf.clientJS, conf.hostJS])
+      .then((results) => {
+        this.skelPage = results[conf.skelFile].split('<!--STRAPP_SRC-->')
+        this.clientJS = results[conf.clientJS]
+        this.hostJS = results[conf.hostJS]
+      })
+      .catch((err) => {
+        console.log(err)
+      })
+    console.log(`HTTP${(conf.tls == undefined) ? '' : 'S'} ` +
+                `Server Started on port ${conf.port}${this.httpdRoot ? 
+                `, serving files from ${this.httpdRoot}`:''}`)
+  },
+
+  /** @func
+   * @summary Create a binding for the server
+   * @desc    makes a new route which is bound to a file or a path.  routes
+   *          bound to files always serve that file, regardless of any
+   *          additional path parameters provided by the URI
+   * @arg     {string} routeName - the route to create
+   * @arg     {string} path - the path to the file or directory to bind
+   */
+  createBind: function (routeName, path) {
+    dlog(`Binding ${routeName} to ${path}`)
+    if (routeName in this.routes)
+      throw new Error(`route ${routeName} already exists`)
+    path = require('path').normalize(path)
+    if (this.bindJail
+        && path.indexOf(`${this.bindJail}/`) !== 0
+        && this.bindJail != path)
+      throw new Error(`${routeName}:${path} jailed to ${this.bindJail}`)
+    if (require('fs').existsSync(path)) {
+      this.routes[routeName] = {
+        bind: {
+          path: path,
+          dir: require('fs').lstatSync(path).isDirectory()
+        }
+      }
+    }
+    else
+      throw new Error(`${path} not found, ${routeName} not bound`)
+  },
+
+  /** @func
+   * @summary Router
+   * @desc    listens for http client requests and services routes/files
+   * @arg     {http.ClientRequest} request
+   * @arg     {http.ServerResponse} response
+   */
+  httpdListener: function (request,response) {
+    dlog(`Received request ${request.method} ${request.url}`)
+    let htArgv = request.url.slice(1).split('?')
+    const routeName = htArgv[0].split('/')[0]
+    let route = this.routes[routeName]
+    /* If the route exists, check if we are a returning host or a new client */
+    if (route) {
+      if (route.bind) {
+        htArgv[0] = htArgv[0].replace(`${routeName}`,'')
+        if (htArgv[0][0] === '/')
+          htArgv[0] = htArgv[0].slice(1)
+        this.serveBind(response, route.bind, htArgv)
+      }
+      //TODO: auth better than this (ip spoofing is easy)
+      // but this will require a more involved host-creation process
+      // that isn't just "give you a route if it's available" on visit
+      /* else if (route.origin == (request.headers['x-forwarded-for'] ||
+                         request.connection.remoteAddress))
+        this.serveHost(response, route, htArgv) */
+      else
+        this.serveClient(request, response, route)
+    }
+    /* If it's a valid routename that doesn't exist, make this client a host */
+    else if (this.validRoutes.test(routeName)) {
+       this.routes[routeName] = true
+      require('get-port')()
+        .then((port) => {
+          this.createHost(routeName, htArgv, port, request, response)
+        })
+        .catch((err) => {
+          delete this.routes[routeName]
+          console.log(err)
+        })
+    }
+    /* Try servicing files if we have a root directory for it */
+    else if (this.httpdRoot) {
+      let realPath = require('path').join(this.httpdRoot, htArgv[0])
+      if (realPath == this.httpdRoot)
+        realPath += '/index.html'
+      if (realPath.indexOf(`${this.httpdRoot}/`) == 0) {
+        const stat_cb = (err, stat) => {
+          if (err) {
+            response.writeHead(404)
+            response.end()
+            console.log(err)
+          }
+          else if (stat.isDirectory()) {
+            realPath += '/index.html'
+            require('fs').lstat(realPath, stat_cb)
+          }
+          else if (stat.isFile())
+            this.serveFile(response, realPath)
+          else {
+            response.writeHead(403)
+            response.end()
+          }
+        }
+        require('fs').lstat(realPath, stat_cb)
+      }
+      else {
+        response.writeHead(400)
+        response.end()
+      }
+    }
+    /* Unhandled */
+    else {
+      response.writeHead(404)
+      response.end()
+    }
+  },
+
+  /** @func
+   * @summary Serves a binding to a client
+   * @desc    Resolves a binding and serves a response to the client
+   * @arg     {http.ServerResponse} response - the response to use
+   * @arg     {Object} bind - the binding to serve the client
+   * @arg     {string[]} argv - path and arguments for the bind
+   */
+  serveBind: function (response, bind, argv) {
+    dlog(`Serving binding ${bind.path}/${argv[0]}`)
+    if (bind.dir) {
+      if (argv[0] == '')
+        argv[0] = 'index.html'
+      this.serveFile(response, require('path').join(bind.path, argv[0]))
+    }
+    else
+      this.serveFile(response, bind.path)
+  },
+
+  /** @func
+   * @summary Serve a route to an http client
+   * @desc    routes may be bound to the filesystem, or to an outgoing host
+   * @arg     {http.ClientRequest} request - request from the client
+   * @arg     {http.ServerResponse} response - response object to use
+   * @arg     {Object} route - route associated with client request
+   */
+  serveClient: function (request, response, route) {
+    const type = request.headers['x-strapp-type']
+    const pubKey = request.headers['x-strapp-pubkey']
+    dlog(`Client ${type || 'HT GET'} request routed to ${route.name}`)
+    switch (type) {
+    case null:
+    case undefined:
+      response.writeHead(200, { 'Content-Type': 'text/html' })
+      response.write(`${this.skelPage[0]}${this.clientJS}${this.skelPage[1]}`)
+      response.end()
+      break
+    case 'ice-candidate-request':
+    case 'ice-candidate-submission':
+    case 'client-sdp-offer':
+      let data = ''
+      if (pubKey) {
+        let data = request.headers['x-strapp-offer']
+        route.pendingResponses.addResponse(pubKey, response)
+        dlog(`${route.origin}=>\n${pubKey}\n${type}`)
+        dlog(JSON.parse(data))
+        route.socket.send(`${pubKey} ${type} ${data}`)
+      }
+      else {
+        response.writeHead(401)
+        response.end()
+      }
+      break
+    default:
+      response.writeHead(400)
+      response.end()
+    }
+  },
+
+  /** @func
+   * @summary Create a new route for a host
+   * @desc    makes a new route for the given route name
+   * @arg     {string} routeName - name of the new route
+   * @arg     {string[]} argv - Origin address from the request that made this
+   *                          route (for security verification on the socket)
+   * @arg     {number|string} port - the port to listen on for websocket
+   * @arg     {http.ClientRequest} request - host's request
+   * @arg     {http.ServerResponse} response - responder
+   */
+  createHost: function (routeName, argv, port, request, response) {
+    const origin = (request.headers['x-forwarded-for'] ||
+                    request.connection.remoteAddress)
+    dlog(`New ${this.httpsOpts?'TLS ':''}route ${routeName}:${port}=>${origin}`)
+    const httpd = this.httpsOpts
+          ? require('https').createServer(this.httpsOpts)
+          : require('http').createServer()
+    const route = {
+      pendingResponses: new Map([]),
+      origin: origin,
+      httpd: httpd,
+      name: routeName,
+      port: port,
+      wsd: undefined,
+      socket: undefined
+    }
+    route.httpd.listen(port)
+    route.wsd = new (require('ws').Server)({ server: httpd })
+      .on('connection', (socket) => {
+        route.socket = socket
+        socket.on('message', (msg) =>
+                  this.hostMessage(msg,route))
+      })
+    route.pendingResponses.addResponse = function (key, response_p) {
+      let responses = this.get(key) || []
+      responses.push(response_p)
+      this.set(key, responses)
+    }
+    this.routes[routeName] = route
+    this.serveHost(response, route, argv)
+  },
+
+  /** @Func    
+   * @summary Serve a route to an authorized http host
+   * @desc    services host application to the client, establishing a socket
+   * @arg     {http.ServerResponse} response - response object to use
+   * @arg     {Object} route - the route that belongs to this host
+   * @arg     {string[]} argv - vector of arguments sent to the host
+   */
+  serveHost: function (response, route, argv) {
+    dlog(`Serving host ${route.origin}`)
+    response.writeHead(200, { 'Content-Type': 'text/html' })
+    response.write(`${this.skelPage[0]}` +
+                   `\tconst _strapp_port = ${route.port}\n` +
+                   `\tconst _strapp_protocol = ` +
+                   `'${this.httpsOpts ? 'wss' : 'ws'}'\n` +
+                   `${this.hostJS}\n${this.skelPage[1]}`)
+    response.end()
+  },
+
+  /** @func
+   * @summary handle host message
+   * @desc    receives a message from a host, handles the command (first character),
+   *          and responds to either the host or the client, or both.  Commands
+   *          are whitespace separated strings.
+   *            Commands:
+   *              Forward Payload to Client)
+   *              < clientKey payload [header]
+   *                Route 'payload' to the client identified by 'clientKey'.
+   *                The optional 'header' argument is a stringified JSON object,
+   *                which will be written to the HTTP response header
+   *                  In case of multiple requests from a single client, the
+   *                  oldest request will be serviced on arrival of message
+   *              Translate SDP and Forward to Client)
+   *              ^ clientKey sdp [header]
+   *                Route the JSON object 'sdp' to the client, after translating
+   *                for interop between browsers using planB or Unified.  Other
+   *                than the interop step, this is identical to the '<' command
+   *              Error)
+   *              ! errorMessage errorCode [offendingMessage]
+   *                Notify host that an error has occured, providing a message
+   *                and error code.  'offendingMessage', if present, is the
+   *                message received from the remote that triggered the error.
+   * @arg     {string} message - raw string from the host
+   * @arg     {Object} route - the route over
+   */
+  hostMessage: function (message, route) {
+    let argv = message.split(' ')
+    const command = argv[0][0]
+    argv = argv.slice(1)
+    dlog(`Received host message from ${route.name}: ${command}`)
+    switch (command) {
+    case '^':
+      if (argv.length < 2) {
+        dlog(`Malformed '${command}' command from ${route.origin}`)
+        route.socket.send(`! "Insufficient arguments" 0 ${message}`)
+        break
+      }
+      argv[1] = JSON.parse(argv[1])
+      //TODO: interop step
+      argv[1] = JSON.stringify(argv[1])
+      //TODO: argv[1] = encryptForClient(argv[0], argv[1])
+      /* Fallthrough to '<' behavior after translating argv[1] */
+    case '<':
+      const response = route.pendingResponses.get(argv[0]).shift()
+      if (!response)
+        route.socket.send(`! "No pending responses for client ${argv[0]}" 0 `
+                          + message)
+      else if (argv.length === 2 || argv.length === 3) {
+        const header = argv.length === 3 ? JSON.parse(argv[2]) : {}
+        if (!('Content-Type' in header))
+          header['Content-Type'] = 'application/octet-stream'
+        response.writeHead(200, header)
+        response.write(argv[1])
+        response.end()
+      }
+      else
+        route.socket.send(`! "Insufficient arguments" 0 ${message}`)
+      break
+    case '!':
+      if (argv.length === 3)
+        argv[0] += `\nIn message: ${argv[2]}`
+      console.log(`Error[${route.origin}|${argv[1]}]:${argv[0]}`)
+      break
+    default:
+      route.socket.send(`! "Unknown command '${command}'" 0 ${message}`)
+      dlog(`Host ${route.origin} send unknown command: ${message}`)
+      break
+    }
+  },
+
+  /** @func
+   * @summary Serve a file to an http client after a request
+   * @desc    reads files from the system to be distributed to clients, and
+   *          buffers recently accessed files
+   * @arg     {http.ServerResponse} response - the response object to use
+   * @arg     {string} filePath - relative location of the file
+   */
+  serveFile: function (response, filePath, rootPath) {
+    //TODO: Make a buffer to hold recently used files, and only read if we
+    // have to (don't forget to preserve mimetype)
+    require('fs').readFile(filePath, { encoding: 'utf8' }, (err, data) => {
+      if (err || data == undefined)
+        response.writeHead(404)
+      else {
+        response.writeHead(200, {
+          'Content-Type': require('mime').lookup(filePath)
+        })
+        response.write(data)
+      }
+      response.end()
+    })
+  },
+
+  /** @func
+   * @summary Synchronize Reading Multiple Files
+   * @desc    reads an array of files into an object, whose keys are the
+   *          input filenames, and values are the data read
+   * @arg     {string[]} files - array of file names to read
+   * @arg     {Object} [readOpts] - options to pass to fs.readFile()
+   */
+  syncReads: (files, readOpts) => new Promise((resolve,reject) => {
+    dlog(`syncing reads from ${files}`)
+    let count = 0
+    let results = {}
+    const read_cb = (fileName) => (err, data) => {
+      if (err)
+        reject(err)
+      else
+        results[fileName] = data
+      if (++count === files.length)
+        resolve(results)
+    }
+    if (readOpts == undefined)
+      readOpts = { encoding: 'utf8' }
+    files.forEach((file) =>
+                  require('fs').readFile(file, readOpts, read_cb(file)))
+  })
 }
+
+module.exports = exports