# all files / lib/ http.js

87.09% Statements 506/581
75.55% Branches 207/274
84.15% Functions 69/82
87.09% Lines 506/581

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     // Public API
    // ==========

    // The main governing power behind the http2 API design is that it should look very similar to the
    // existing node.js [HTTPS API][1] (which is, in turn, almost identical to the [HTTP API][2]). The
    // additional features of HTTP/2 are exposed as extensions to this API. Furthermore, node-http2
    // should fall back to using HTTP/1.1 if needed. Compatibility with undocumented or deprecated
    // elements of the node.js HTTP/HTTPS API is a non-goal.
    //
    // Additional and modified API elements
    // ------------------------------------
    //
    // - **Class: http2.Endpoint**: an API for using the raw HTTP/2 framing layer. For documentation
    //   see [protocol/endpoint.js](protocol/endpoint.html).
    //
    // - **Class: http2.Server**
    //   - **Event: 'connection' (socket, [endpoint])**: there's a second argument if the negotiation of
    //     HTTP/2 was successful: the reference to the [Endpoint](protocol/endpoint.html) object tied to the
    //     socket.
    //
    // - **http2.createServer(options, [requestListener])**: additional option:
    //   - **log**: an optional [bunyan](https://github.com/trentm/node-bunyan) logger object
    //
    // - **Class: http2.ServerResponse**
    //   - **response.push(options)**: initiates a server push. `options` describes the 'imaginary'
    //     request to which the push stream is a response; the possible options are identical to the
    //     ones accepted by `http2.request`. Returns a ServerResponse object that can be used to send
    //     the response headers and content.
    //
    // - **Class: http2.Agent**
    //   - **new Agent(options)**: additional option:
    //     - **log**: an optional [bunyan](https://github.com/trentm/node-bunyan) logger object
    //   - **agent.sockets**: only contains TCP sockets that corresponds to HTTP/1 requests.
    //   - **agent.endpoints**: contains [Endpoint](protocol/endpoint.html) objects for HTTP/2 connections.
    //
    // - **http2.request(options, [callback])**:
    //   - similar to http.request
    //
    // - **http2.get(options, [callback])**:
    //   - similar to http.get
    //
    // - **Class: http2.ClientRequest**
    //   - **Event: 'socket' (socket)**: in case of an HTTP/2 incoming message, `socket` is a reference
    //     to the associated [HTTP/2 Stream](protocol/stream.html) object (and not to the TCP socket).
    //   - **Event: 'push' (promise)**: signals the intention of a server push associated to this
    //     request. `promise` is an IncomingPromise. If there's no listener for this event, the server
    //     push is cancelled.
    //   - **request.setPriority(priority)**: assign a priority to this request. `priority` is a number
    //     between 0 (highest priority) and 2^31-1 (lowest priority). Default value is 2^30.
    //
    // - **Class: http2.IncomingMessage**
    //   - has two subclasses for easier interface description: **IncomingRequest** and
    //     **IncomingResponse**
    //   - **message.socket**: in case of an HTTP/2 incoming message, it's a reference to the associated
    //     [HTTP/2 Stream](protocol/stream.html) object (and not to the TCP socket).
    //
    // - **Class: http2.IncomingRequest (IncomingMessage)**
    //   - **message.url**: in case of an HTTP/2 incoming request, the `url` field always contains the
    //     path, and never a full url (it contains the path in most cases in the HTTPS api as well).
    //   - **message.scheme**: additional field. Mandatory HTTP/2 request metadata.
    //   - **message.host**: additional field. Mandatory HTTP/2 request metadata. Note that this
    //     replaces the old Host header field, but node-http2 will add Host to the `message.headers` for
    //     backwards compatibility.
    //
    // - **Class: http2.IncomingPromise (IncomingRequest)**
    //   - contains the metadata of the 'imaginary' request to which the server push is an answer.
    //   - **Event: 'response' (response)**: signals the arrival of the actual push stream. `response`
    //     is an IncomingResponse.
    //   - **Event: 'push' (promise)**: signals the intention of a server push associated to this
    //     request. `promise` is an IncomingPromise. If there's no listener for this event, the server
    //     push is cancelled.
    //   - **promise.cancel()**: cancels the promised server push.
    //   - **promise.setPriority(priority)**: assign a priority to this push stream. `priority` is a
    //     number between 0 (highest priority) and 2^31-1 (lowest priority). Default value is 2^30.
    //
    // API elements not yet implemented
    // --------------------------------
    //
    // - **Class: http2.Server**
    //   - **server.maxHeadersCount**
    //
    // API elements that are not applicable to HTTP/2
    // ----------------------------------------------
    //
    // The reason may be deprecation of certain HTTP/1.1 features, or that some API elements simply
    // don't make sense when using HTTP/2. These will not be present when a request is done with HTTP/2,
    // but will function normally when falling back to using HTTP/1.1.
    //
    // - **Class: http2.Server**
    //   - **Event: 'checkContinue'**: not in the spec
    //   - **Event: 'upgrade'**: upgrade is deprecated in HTTP/2
    //   - **Event: 'timeout'**: HTTP/2 sockets won't timeout because of application level keepalive
    //     (PING frames)
    //   - **Event: 'connect'**: not yet supported
    //   - **server.setTimeout(msecs, [callback])**
    //   - **server.timeout**
    //
    // - **Class: http2.ServerResponse**
    //   - **Event: 'close'**
    //   - **Event: 'timeout'**
    //   - **response.writeContinue()**
    //   - **response.writeHead(statusCode, [reasonPhrase], [headers])**: reasonPhrase will always be
    //     ignored since [it's not supported in HTTP/2][3]
    //   - **response.setTimeout(timeout, [callback])**
    //
    // - **Class: http2.Agent**
    //   - **agent.maxSockets**: only affects HTTP/1 connection pool. When using HTTP/2, there's always
    //     one connection per host.
    //
    // - **Class: http2.ClientRequest**
    //   - **Event: 'upgrade'**
    //   - **Event: 'connect'**
    //   - **Event: 'continue'**
    //   - **request.setTimeout(timeout, [callback])**
    //   - **request.setNoDelay([noDelay])**
    //   - **request.setSocketKeepAlive([enable], [initialDelay])**
    //
    // - **Class: http2.IncomingMessage**
    //   - **Event: 'close'**
    //   - **message.setTimeout(timeout, [callback])**
    //
    // [1]: https://nodejs.org/api/https.html
    // [2]: https://nodejs.org/api/http.html
    // [3]: https://tools.ietf.org/html/rfc7540#section-8.1.2.4

    // Common server and client side code
    // ==================================

    var net = require('net');
    var url = require('url');
    var util = require('util');
    var EventEmitter = require('events').EventEmitter;
    var PassThrough = require('stream').PassThrough;
    var Readable = require('stream').Readable;
    var Writable = require('stream').Writable;
    var protocol = require('./protocol');
    var Endpoint = protocol.Endpoint;
    var https = require('https');

    exports.STATUS_CODES = {
        '202': 'Accepted',
        '502': 'Bad Gateway',
        '400': 'Bad Request',
        '409': 'Conflict',
        '100': 'Continue',
        '201': 'Created',
        '417': 'Expectation Failed',
        '424': 'Failed Dependency',
        '403': 'Forbidden',
        '504': 'Gateway Timeout',
        '410': 'Gone',
        '505': 'HTTP Version Not Supported',
        '419': 'Insufficient Space on Resource',
        '507': 'Insufficient Storage',
        '500': 'Server Error',
        '411': 'Length Required',
        '423': 'Locked',
        '420': 'Method Failure',
        '405': 'Method Not Allowed',
        '301': 'Moved Permanently',
        '302': 'Moved Temporarily',
        '207': 'Multi-Status',
        '300': 'Multiple Choices',
        '511': 'Network Authentication Required',
        '204': 'No Content',
        '203': 'Non Authoritative Information',
        '406': 'Not Acceptable',
        '404': 'Not Found',
        '501': 'Not Implemented',
        '304': 'Not Modified',
        '200': 'OK',
        '206': 'Partial Content',
        '402': 'Payment Required',
        '308': 'Permanent Redirect',
        '412': 'Precondition Failed',
        '428': 'Precondition Required',
        '102': 'Processing',
        '407': 'Proxy Authentication Required',
        '431': 'Request Header Fields Too Large',
        '408': 'Request Timeout',
        '413': 'Request Entity Too Large',
        '414': 'Request-URI Too Long',
        '416': 'Requested Range Not Satisfiable',
        '205': 'Reset Content',
        '303': 'See Other',
        '503': 'Service Unavailable',
        '101': 'Switching Protocols',
        '307': 'Temporary Redirect',
        '429': 'Too Many Requests',
        '401': 'Unauthorized',
        '422': 'Unprocessable Entity',
        '415': 'Unsupported Media Type',
        '305': 'Use Proxy'
    };
    exports.IncomingMessage = IncomingMessage;
    exports.OutgoingMessage = OutgoingMessage;
    exports.protocol = protocol;

    var deprecatedHeaders = [
      'connection',
      'host',
      'keep-alive',
      'proxy-connection',
      'transfer-encoding',
      'upgrade'
    ];

    // When doing NPN/ALPN negotiation, HTTP/1.1 is used as fallback
    var supportedProtocols = [protocol.VERSION, 'http/1.1', 'http/1.0'];

    // Ciphersuite list based on the recommendations of https://wiki.mozilla.org/Security/Server_Side_TLS
    // The only modification is that kEDH+AESGCM were placed after DHE and ECDHE suites
    var cipherSuites = [
      'ECDHE-RSA-AES128-GCM-SHA256',
      'ECDHE-ECDSA-AES128-GCM-SHA256',
      'ECDHE-RSA-AES256-GCM-SHA384',
      'ECDHE-ECDSA-AES256-GCM-SHA384',
      'DHE-RSA-AES128-GCM-SHA256',
      'DHE-DSS-AES128-GCM-SHA256',
      'ECDHE-RSA-AES128-SHA256',
      'ECDHE-ECDSA-AES128-SHA256',
      'ECDHE-RSA-AES128-SHA',
      'ECDHE-ECDSA-AES128-SHA',
      'ECDHE-RSA-AES256-SHA384',
      'ECDHE-ECDSA-AES256-SHA384',
      'ECDHE-RSA-AES256-SHA',
      'ECDHE-ECDSA-AES256-SHA',
      'DHE-RSA-AES128-SHA256',
      'DHE-RSA-AES128-SHA',
      'DHE-DSS-AES128-SHA256',
      'DHE-RSA-AES256-SHA256',
      'DHE-DSS-AES256-SHA',
      'DHE-RSA-AES256-SHA',
      'kEDH+AESGCM',
      'AES128-GCM-SHA256',
      'AES256-GCM-SHA384',
      'ECDHE-RSA-RC4-SHA',
      'ECDHE-ECDSA-RC4-SHA',
      'AES128',
      'AES256',
      'RC4-SHA',
      'HIGH',
      '!aNULL',
      '!eNULL',
      '!EXPORT',
      '!DES',
      '!3DES',
      '!MD5',
      '!PSK'
    ].join(':');

    // Logging
    // -------

    // Logger shim, used when no logger is provided by the user.
    function noop() {}
    var defaultLogger = {
      fatal: noop,
      error: noop,
      warn : noop,
      info : noop,
      debug: noop,
      trace: noop,

      child: function() { return this; }
    };

    // Bunyan serializers exported by submodules that are worth adding when creating a logger.
    exports.serializers = protocol.serializers;

    // IncomingMessage class
    // ---------------------

    function IncomingMessage(stream) {
      // * This is basically a read-only wrapper for the [Stream](protocol/stream.html) class.
      PassThrough.call(this);
      stream.pipe(this);
      this.socket = this.stream = stream;

      this._log = stream._log.child({ component: 'http' });

      // * HTTP/2.0 does not define a way to carry the version identifier that is included in the
      //   HTTP/1.1 request/status line. Version is always 2.0.
      this.httpVersion = '2.0';
      this.httpVersionMajor = 2;
      this.httpVersionMinor = 0;

      // * `this.headers` will store the regular headers (and none of the special colon headers)
      this.headers = {};
      this.trailers = undefined;
      this._lastHeadersSeen = undefined;

      // * Other metadata is filled in when the headers arrive.
      stream.once('headers', this._onHeaders.bind(this));
      stream.once('end', this._onEnd.bind(this));
    }
    IncomingMessage.prototype = Object.create(PassThrough.prototype, { constructor: { value: IncomingMessage } });

    // [Request Header Fields](https://tools.ietf.org/html/rfc7540#section-8.1.2.3)
    // * `headers` argument: HTTP/2.0 request and response header fields carry information as a series
    //   of key-value pairs. This includes the target URI for the request, the status code for the
    //   response, as well as HTTP header fields.
    IncomingMessage.prototype._onHeaders = function _onHeaders(headers) {
      // * Detects malformed headers
      this._validateHeaders(headers);

      // * Store the _regular_ headers in `this.headers`
      for (var name in headers) {
        if (name[0] !== ':') {
          if (name === 'set-cookie' && !Array.isArray(headers[name])) {
            this.headers[name] = [headers[name]];
          } else {
            this.headers[name] = headers[name];
          }
        }
      }

      // * The last header block, if it's not the first, will represent the trailers
      var self = this;
      this.stream.on('headers', function(headers) {
        self._lastHeadersSeen = headers;
      });
    };

    IncomingMessage.prototype._onEnd = function _onEnd() {
      this.trailers = this._lastHeadersSeen;
    };

    IncomingMessage.prototype.setTimeout = noop;

    IncomingMessage.prototype._checkSpecialHeader = function _checkSpecialHeader(key, value) {
      Iif ((typeof value !== 'string') || (value.length === 0)) {
        this._log.error({ key: key, value: value }, 'Invalid or missing special header field');
        this.stream.reset('PROTOCOL_ERROR');
      }

      return value;
    };

    var headerNamePattern = /[A-Z]/;
    IncomingMessage.prototype._validateHeaders = function _validateHeaders(headers) {
      // * An HTTP/2.0 request or response MUST NOT include any of the following header fields:
      //   Connection, Host, Keep-Alive, Proxy-Connection, Transfer-Encoding, and Upgrade. A server
      //   MUST treat the presence of any of these header fields as a stream error of type
      //   PROTOCOL_ERROR.
      //  If the TE header is present, it's only valid value is 'trailers'
      for (var i = 0; i < deprecatedHeaders.length; i++) {
        var key = deprecatedHeaders[i];
        Iif (key in headers || (key === 'te' && headers[key] !== 'trailers')) {
            this._log.error({ key: key, value: headers[key] }, 'Deprecated header found');
            this.stream.reset('PROTOCOL_ERROR');
          return;
        }
      }

      for (var headerName in headers) {
        Eif (headers.hasOwnProperty(headerName)) {
          // * Empty header name field is malformed
          Iif (headerName.length <= 1) {
            this.stream.reset('PROTOCOL_ERROR');
            return;
          }
          // * A request or response containing uppercase header name field names MUST be
          //   treated as malformed (Section 8.1.3.5). Implementations that detect malformed
          //   requests or responses need to ensure that the stream ends.
          Iif(headerNamePattern.test(headerName)) {
            this.stream.reset('PROTOCOL_ERROR');
            return;
          }
        }
      }
    };

    // OutgoingMessage class
    // ---------------------

    function OutgoingMessage() {
      // * This is basically a read-only wrapper for the [Stream](protocol/stream.html) class.
      Writable.call(this);

      this._headers = {};
      this._trailers = undefined;
      this.headersSent = false;
      this.finished = false;

      this.on('finish', this._finish);
    }
    OutgoingMessage.prototype = Object.create(Writable.prototype, { constructor: { value: OutgoingMessage } });

    OutgoingMessage.prototype._write = function _write(chunk, encoding, callback) {
      if (this.stream) {
        this.stream.write(chunk, encoding, callback);
      } else {
        this.once('socket', this._write.bind(this, chunk, encoding, callback));
      }
    };

    OutgoingMessage.prototype._finish = function _finish() {
      if (this.stream) {
        if (this._trailers) {
          Iif (this.request) {
            this.request.addTrailers(this._trailers);
          } else {
            this.stream.headers(this._trailers);
          }
        }
        this.finished = true;
        this.stream.end();
      } else {
        this.once('socket', this._finish.bind(this));
      }
    };
    OutgoingMessage.prototype.setHeader = function setHeader(name, value) {
      Iif (this.headersSent) {
        return this.emit('error', new Error('Can\'t set headers after they are sent.'));
      } else {
        name = name.toLowerCase();
        Iif (deprecatedHeaders.indexOf(name) !== -1) {
            return this.emit('error', new Error('Cannot set deprecated header: ' + name));
        }
        this._headers[name] = value;
      }
    };

    OutgoingMessage.prototype.removeHeader = function removeHeader(name) {
      Iif (this.headersSent) {
        return this.emit('error', new Error('Can\'t remove headers after they are sent.'));
      } else {
        delete this._headers[name.toLowerCase()];
      }
    };

    OutgoingMessage.prototype.getHeader = function getHeader(name) {
      return this._headers[name.toLowerCase()];
    };

    OutgoingMessage.prototype.addTrailers = function addTrailers(trailers) {
      this._trailers = trailers;
    };

    OutgoingMessage.prototype.setTimeout = noop;

    OutgoingMessage.prototype._checkSpecialHeader = IncomingMessage.prototype._checkSpecialHeader;

    // Server side
    // ===========

    exports.Server = Server;
    exports.IncomingRequest = IncomingRequest;
    exports.OutgoingResponse = OutgoingResponse;
    exports.ServerResponse = OutgoingResponse; // for API compatibility

    // Forward events `event` on `source` to all listeners on `target`.
    //
    // Note: The calling context is `source`.
    function forwardEvent(event, source, target) {
      function forward() {
        var listeners = target.listeners(event);

        var n = listeners.length;

        // Special case for `error` event with no listeners.
        Iif (n === 0 && event === 'error') {
          var args = [event];
          args.push.apply(args, arguments);

          target.emit.apply(target, args);
          return;
        }

        for (var i = 0; i < n; ++i) {
          listeners[i].apply(source, arguments);
        }
      }

      source.on(event, forward);

      // A reference to the function is necessary to be able to stop
      // forwarding.
      return forward;
    }

    // Server class
    // ------------

    function Server(options) {
      options = Object.assign({}, options);

      this._log = (options.log || defaultLogger).child({ component: 'http' });
      this._settings = options.settings;

      var start = this._start.bind(this);
      var fallback = this._fallback.bind(this);

      // HTTP2 over TLS (using NPN or ALPN)
      if ((options.key && options.cert) || options.pfx) {
        this._log.info('Creating HTTP/2 server over TLS');
        this._mode = 'tls';
        options.ALPNProtocols = supportedProtocols;
        options.NPNProtocols = supportedProtocols;
        options.ciphers = options.ciphers || cipherSuites;
        options.honorCipherOrder = (options.honorCipherOrder !== false);
        this._server = https.createServer(options);
        this._originalSocketListeners = this._server.listeners('secureConnection');
        this._server.removeAllListeners('secureConnection');
        this._server.on('secureConnection', function(socket) {
          var negotiatedProtocol = socket.alpnProtocol || socket.npnProtocol;
          // It's true that the client MUST use SNI, but if it doesn't, we don't care, don't fall back to HTTP/1,
          // since if the ALPN negotiation is otherwise successful, the client thinks we speak HTTP/2 but we don't.
          if (negotiatedProtocol === protocol.VERSION) {
            start(socket);
          } else {
            fallback(socket);
          }
        });
        this._server.on('request', this.emit.bind(this, 'request'));

        forwardEvent('error', this._server, this);
        forwardEvent('listening', this._server, this);
      }

      // HTTP2 over any generic transport
      else if (options.transport){
          this._mode = 'plain';
          this._server = options.transport(options, start);
      }

      // HTTP2 over plain TCP (Perhaps this should be deprecated??)
      else if (options.plain) {
        this._log.info('Creating HTTP/2 server over plain TCP');
        this._mode = 'plain';
        this._server = net.createServer(start);
      }

      // HTTP/2 with HTTP/1.1 upgrade
      else {
        this._log.error('Trying to create HTTP/2 server with Upgrade from HTTP/1.1');
        throw new Error('HTTP1.1 -> HTTP2 upgrade is not yet supported. Please provide TLS keys.');
      }

      this._server.on('close', this.emit.bind(this, 'close'));
    }
    Server.prototype = Object.create(EventEmitter.prototype, { constructor: { value: Server } });

    // Starting HTTP/2
    Server.prototype._start = function _start(socket) {
      var endpoint = new Endpoint(this._log, 'SERVER', this._settings);

      this._log.info({ e: endpoint,
                       client: socket.remoteAddress + ':' + socket.remotePort,
                       SNI: socket.servername
                     }, 'New incoming HTTP/2 connection');

      endpoint.pipe(socket).pipe(endpoint);

      var self = this;
      endpoint.on('stream', function _onStream(stream) {
        var response = new OutgoingResponse(stream);
        var request = new IncomingRequest(stream);

        // Some conformance to Node.js Https specs allows to distinguish clients:
        request.remoteAddress = socket.remoteAddress;
        request.remotePort = socket.remotePort;
        request.connection = request.socket = response.socket = socket;

        request.once('ready', self.emit.bind(self, 'request', request, response));
      });

      endpoint.on('error', this.emit.bind(this, 'clientError'));
      socket.on('error', this.emit.bind(this, 'clientError'));

      this.emit('connection', socket, endpoint);
    };

    Server.prototype._fallback = function _fallback(socket) {
      var negotiatedProtocol = socket.alpnProtocol || socket.npnProtocol;

      this._log.info({ client: socket.remoteAddress + ':' + socket.remotePort,
                       protocol: negotiatedProtocol,
                       SNI: socket.servername
                     }, 'Falling back to simple HTTPS');

      for (var i = 0; i < this._originalSocketListeners.length; i++) {
        this._originalSocketListeners[i].call(this._server, socket);
      }

      this.emit('connection', socket);
    };

    // There are [3 possible signatures][1] of the `listen` function. Every arguments is forwarded to
    // the backing TCP or HTTPS server.
    // [1]: https://nodejs.org/api/http.html#http_server_listen_port_hostname_backlog_callback
    Server.prototype.listen = function listen(port, hostname) {
      this._log.info({ on: ((typeof hostname === 'string') ? (hostname + ':' + port) : port) },
                     'Listening for incoming connections');
      this._server.listen.apply(this._server, arguments);

      return this._server;
    };

    Server.prototype.close = function close(callback) {
      this._log.info('Closing server');
      this._server.close(callback);
    };

    Server.prototype.setTimeout = function setTimeout(timeout, callback) {
      Eif (this._mode === 'tls') {
        this._server.setTimeout(timeout, callback);
      }
    };

    Object.defineProperty(Server.prototype, 'timeout', {
      get: function getTimeout() {
        Eif (this._mode === 'tls') {
          return this._server.timeout;
        } else {
          return undefined;
        }
      },
      set: function setTimeout(timeout) {
        Eif (this._mode === 'tls') {
          this._server.timeout = timeout;
        }
      }
    });

    // Overriding `EventEmitter`'s `on(event, listener)` method to forward certain subscriptions to
    // `server`.There are events on the `http.Server` class where it makes difference whether someone is
    // listening on the event or not. In these cases, we can not simply forward the events from the
    // `server` to `this` since that means a listener. Instead, we forward the subscriptions.
    Server.prototype.on = function on(event, listener) {
      Iif ((event === 'upgrade') || (event === 'timeout')) {
        return this._server.on(event, listener && listener.bind(this));
      } else {
        return EventEmitter.prototype.on.call(this, event, listener);
      }
    };

    // `addContext` is used to add Server Name Indication contexts
    Server.prototype.addContext = function addContext(hostname, credentials) {
      if (this._mode === 'tls') {
        this._server.addContext(hostname, credentials);
      }
    };

    Server.prototype.address = function address() {
      return this._server.address();
    };

    function createServerRaw(options, requestListener) {
      Iif (typeof options === 'function') {
        requestListener = options;
        options = {};
      }

      Iif (options.pfx || (options.key && options.cert)) {
        throw new Error('options.pfx, options.key, and options.cert are nonsensical!');
      }

      options.plain = true;
      var server = new Server(options);

      Eif (requestListener) {
        server.on('request', requestListener);
      }

      return server;
    }

    function createServerTLS(options, requestListener) {
      if (typeof options === 'function') {
        throw new Error('options are required!');
      }
      Iif (!options.pfx && !(options.key && options.cert)) {
        throw new Error('options.pfx or options.key and options.cert are required!');
      }
      options.plain = false;

      var server = new Server(options);

      if (requestListener) {
        server.on('request', requestListener);
      }

      return server;
    }

    // Exposed main interfaces for HTTPS connections (the default)
    exports.https = {};
    exports.createServer = exports.https.createServer = createServerTLS;
    exports.request = exports.https.request = requestTLS;
    exports.get = exports.https.get = getTLS;

    // Exposed main interfaces for raw TCP connections (not recommended)
    exports.raw = {};
    exports.raw.createServer = createServerRaw;
    exports.raw.request = requestRaw;
    exports.raw.get = getRaw;

    // Exposed main interfaces for HTTP plaintext upgrade connections (not implemented)
    function notImplemented() {
        throw new Error('HTTP UPGRADE is not implemented!');
    }

    exports.http = {};
    exports.http.createServer = exports.http.request = exports.http.get = notImplemented;

    // IncomingRequest class
    // ---------------------

    function IncomingRequest(stream) {
      IncomingMessage.call(this, stream);
    }
    IncomingRequest.prototype = Object.create(IncomingMessage.prototype, { constructor: { value: IncomingRequest } });

    // [Request Header Fields](https://tools.ietf.org/html/rfc7540#section-8.1.2.3)
    // * `headers` argument: HTTP/2.0 request and response header fields carry information as a series
    //   of key-value pairs. This includes the target URI for the request, the status code for the
    //   response, as well as HTTP header fields.
    IncomingRequest.prototype._onHeaders = function _onHeaders(headers) {
      // * The ":method" header field includes the HTTP method
      // * The ":scheme" header field includes the scheme portion of the target URI
      // * The ":authority" header field includes the authority portion of the target URI
      // * The ":path" header field includes the path and query parts of the target URI.
      //   This field MUST NOT be empty; URIs that do not contain a path component MUST include a value
      //   of '/', unless the request is an OPTIONS request for '*', in which case the ":path" header
      //   field MUST include '*'.
      // * All HTTP/2.0 requests MUST include exactly one valid value for all of these header fields. A
      //   server MUST treat the absence of any of these header fields, presence of multiple values, or
      //   an invalid value as a stream error of type PROTOCOL_ERROR.
      this.method = this._checkSpecialHeader(':method'   , headers[':method']);
      this.scheme = this._checkSpecialHeader(':scheme'   , headers[':scheme']);
      this.host   = this._checkSpecialHeader(':authority', headers[':authority']  );
      this.url    = this._checkSpecialHeader(':path'     , headers[':path']  );
      Iif (!this.method || !this.scheme || !this.host || !this.url) {
        // This is invalid, and we've sent a RST_STREAM, so don't continue processing
        return;
      }

      // * Host header is included in the headers object for backwards compatibility.
      this.headers.host = this.host;

      // * Handling regular headers.
      IncomingMessage.prototype._onHeaders.call(this, headers);

      // * Signaling that the headers arrived.
      this._log.info({ method: this.method, scheme: this.scheme, host: this.host,
                       path: this.url, headers: this.headers }, 'Incoming request');
      this.emit('ready');
    };

    // OutgoingResponse class
    // ----------------------

    function OutgoingResponse(stream) {
      OutgoingMessage.call(this);

      this._log = stream._log.child({ component: 'http' });

      this.stream = stream;
      this.statusCode = 200;
      this.sendDate = true;

      this.stream.once('headers', this._onRequestHeaders.bind(this));
    }
    OutgoingResponse.prototype = Object.create(OutgoingMessage.prototype, { constructor: { value: OutgoingResponse } });

    OutgoingResponse.prototype.writeHead = function writeHead(statusCode, reasonPhrase, headers) {
      if (this.headersSent) {
        return;
      }

      if (typeof reasonPhrase === 'string') {
        this._log.warn('Reason phrase argument was present but ignored by the writeHead method');
      } else {
        headers = reasonPhrase;
      }

      for (var headerName in headers) {
        Eif (headers.hasOwnProperty(headerName)) {
          this.setHeader(headerName, headers[headerName]);
        }
      }
      headers = this._headers;

      if (this.sendDate && !('date' in this._headers)) {
        headers.date = (new Date()).toUTCString();
      }

      this._log.info({ status: statusCode, headers: this._headers }, 'Sending server response');

      headers[':status'] = this.statusCode = statusCode;

      this.stream.headers(headers);
      this.headersSent = true;
    };

    OutgoingResponse.prototype._implicitHeaders = function _implicitHeaders() {
      if (!this.headersSent) {
        this.writeHead(this.statusCode);
      }
    };

    OutgoingResponse.prototype._implicitHeader = function() {
      this._implicitHeaders();
    };

    OutgoingResponse.prototype.write = function write() {
      this._implicitHeaders();
      return OutgoingMessage.prototype.write.apply(this, arguments);
    };

    OutgoingResponse.prototype.end = function end() {
      this.finished = true;
      this._implicitHeaders();
      return OutgoingMessage.prototype.end.apply(this, arguments);
    };

    OutgoingResponse.prototype._onRequestHeaders = function _onRequestHeaders(headers) {
      this._requestHeaders = headers;
    };

    OutgoingResponse.prototype.push = function push(options) {
      if (typeof options === 'string') {
        options = url.parse(options);
      }

      Iif (!options.path) {
        throw new Error('`path` option is mandatory.');
      }

      var promise = Object.assign({
        ':method': (options.method || 'GET').toUpperCase(),
        ':scheme': (options.protocol && options.protocol.slice(0, -1)) || this._requestHeaders[':scheme'],
        ':authority': options.hostname || options.host || this._requestHeaders[':authority'],
        ':path': options.path
      }, options.headers);

      this._log.info({ method: promise[':method'], scheme: promise[':scheme'],
                       authority: promise[':authority'], path: promise[':path'],
                       headers: options.headers }, 'Promising push stream');

      var pushStream = this.stream.promise(promise);

      return new OutgoingResponse(pushStream);
    };

    OutgoingResponse.prototype.altsvc = function altsvc(host, port, protocolID, maxAge, origin) {
        if (origin === undefined) {
            origin = "";
        }
        this.stream.altsvc(host, port, protocolID, maxAge, origin);
    };

    // Overriding `EventEmitter`'s `on(event, listener)` method to forward certain subscriptions to
    // `request`. See `Server.prototype.on` for explanation.
    OutgoingResponse.prototype.on = function on(event, listener) {
      Iif (this.request && (event === 'timeout')) {
        this.request.on(event, listener && listener.bind(this));
      } else {
        OutgoingMessage.prototype.on.call(this, event, listener);
      }
    };

    // Client side
    // ===========

    exports.ClientRequest = OutgoingRequest; // for API compatibility
    exports.OutgoingRequest = OutgoingRequest;
    exports.IncomingResponse = IncomingResponse;
    exports.Agent = Agent;
    exports.globalAgent = undefined;

    function requestRaw(options, callback) {
      if (typeof options === "string") {
        options = url.parse(options);
      }
      options.plain = true;
      Iif (options.protocol && options.protocol !== "http:") {
        throw new Error('This interface only supports http-schemed URLs');
      }
      Iif (options.agent && typeof(options.agent.request) === 'function') {
        var agentOptions = Object.assign({}, options);
        delete agentOptions.agent;
        return options.agent.request(agentOptions, callback);
      }
      return exports.globalAgent.request(options, callback);
    }

    function requestTLS(options, callback) {
      if (typeof options === "string") {
        options = url.parse(options);
      }
      options.plain = false;
      Iif (options.protocol && options.protocol !== "https:") {
        throw new Error('This interface only supports https-schemed URLs');
      }
      Iif (options.agent && typeof(options.agent.request) === 'function') {
        var agentOptions = Object.assign({}, options);
        delete agentOptions.agent;
        return options.agent.request(agentOptions, callback);
      }
      return exports.globalAgent.request(options, callback);
    }

    function getRaw(options, callback) {
      if (typeof options === "string") {
        options = url.parse(options);
      }
      options.plain = true;
      Iif (options.protocol && options.protocol !== "http:") {
        throw new Error('This interface only supports http-schemed URLs');
      }
      Iif (options.agent && typeof(options.agent.get) === 'function') {
        var agentOptions = Object.assign({}, options);
        delete agentOptions.agent;
        return options.agent.get(agentOptions, callback);
      }
      return exports.globalAgent.get(options, callback);
    }

    function getTLS(options, callback) {
      if (typeof options === "string") {
        options = url.parse(options);
      }
      options.plain = false;
      Iif (options.protocol && options.protocol !== "https:") {
        throw new Error('This interface only supports https-schemed URLs');
      }
      Iif (options.agent && typeof(options.agent.get) === 'function') {
        var agentOptions = Object.assign({}, options);
        delete agentOptions.agent;
        return options.agent.get(agentOptions, callback);
      }
      return exports.globalAgent.get(options, callback);
    }

    // Agent class
    // -----------

    function Agent(options) {
      EventEmitter.call(this);
      this.setMaxListeners(0);

      options = Object.assign({}, options);

      this._settings = options.settings;
      this._log = (options.log || defaultLogger).child({ component: 'http' });
      this.endpoints = {};

      // * Using an own HTTPS agent, because the global agent does not look at `NPN/ALPNProtocols` when
      //   generating the key identifying the connection, so we may get useless non-negotiated TLS
      //   channels even if we ask for a negotiated one. This agent will contain only negotiated
      //   channels.
      options.ALPNProtocols = supportedProtocols;
      options.NPNProtocols = supportedProtocols;
      this._httpsAgent = new https.Agent(options);

      this.sockets = this._httpsAgent.sockets;
      this.requests = this._httpsAgent.requests;
    }
    Agent.prototype = Object.create(EventEmitter.prototype, { constructor: { value: Agent } });

    Agent.prototype.request = function request(options, callback) {
      Iif (typeof options === 'string') {
        options = url.parse(options);
      } else {
        options = Object.assign({}, options);
      }

      options.method = (options.method || 'GET').toUpperCase();
      options.protocol = options.protocol || 'https:';
      options.host = options.hostname || options.host || 'localhost';
      options.port = options.port || 443;
      options.path = options.path || '/';

      if (!options.plain && options.protocol === 'http:') {
        this._log.error('Trying to negotiate client request with Upgrade from HTTP/1.1');
        this.emit('error', new Error('HTTP1.1 -> HTTP2 upgrade is not yet supported.'));
      }

      var key, endpoint,
        self = this,
        request = new OutgoingRequest(self._log);

      if (callback) {
        request.on('response', callback);
      }

      // Re-use transportUrl endPoint if specified
      var key;
      Iif (options.transportUrl && options.transport) {
        key = ([
            options.transportUrl
        ]).join(':');

      // Re-use host:port endPoint
      } else {
        key = ([
            !!options.plain,
            options.host,
            options.port
        ]).join(':');
      }

      // * There's an existing HTTP/2 connection to this host
      if (key in this.endpoints && this.endpoints[key]) {
        endpoint = this.endpoints[key];
        request._start(endpoint.createStream(), options);
      }

      // * HTTP/2 over generic stream transport
      else if(options.transport) {
        endpoint = new Endpoint(this._log, 'CLIENT', this._settings);
        endpoint.socket = options.transport;

        endpoint.socket.on('error', function (error) {
            self._log.error('Socket error: ' + error.toString());
            request.emit('error', error);
        });

        endpoint.on('error', function(error){
            self._log.error('Connection error: ' + error.toString());
            request.emit('error', error);
        });

        endpoint.socket.on('close', function (error) {
            // DPW This is sort of a hack to protect against
            // the reuse of a endpoint that has the underlying
            // connection closed.  It would probably be better
            // to implement this near lin 933 (if (key in this.endpoints))
            // by checking the endpoint state (requires new API to expose)

            // Alternatively, this could be a bug with my WS connection
            // not emitting an error when it is unexpectedly closed ??
            delete self.endpoints[key];
        });

        this.endpoints[key] = endpoint;
        endpoint.pipe(endpoint.socket).pipe(endpoint);
        request._start(endpoint.createStream(), options);
    }
      // * HTTP/2 over plain TCP
          // TODO deprecate?
      else if (options.plain) {
        endpoint = new Endpoint(this._log, 'CLIENT', this._settings);
        endpoint.socket = net.connect({
          host: options.host,
          port: options.port,
          localAddress: options.localAddress
        });

        endpoint.socket.on('error', function (error) {
          self._log.error('Socket error: ' + error.toString());
          request.emit('error', error);
        });

        endpoint.on('error', function(error){
          self._log.error('Connection error: ' + error.toString());
          request.emit('error', error);
        });

        this.endpoints[key] = endpoint;
        endpoint.pipe(endpoint.socket).pipe(endpoint);
        request._start(endpoint.createStream(), options);
      }

      // * HTTP/2 over TLS negotiated using NPN or ALPN, or fallback to HTTPS1
      else {
        var started = false;
        var createAgent = hasAgentOptions(options);
        options.ALPNProtocols = supportedProtocols;
        options.NPNProtocols = supportedProtocols;
        options.servername = options.host; // Server Name Indication
        options.ciphers = options.ciphers || cipherSuites;
        Iif (createAgent) {
          options.agent = new https.Agent(options);
        } else Eif (!options.agent) {
          options.agent = this._httpsAgent;
        }
        var httpsRequest = https.request(options);

        httpsRequest.on('error', function (error) {
          self._log.error('Socket error: ' + error.toString());
          self.removeAllListeners(key);
          request.emit('error', error);
        });

        httpsRequest.on('socket', function(socket) {
          var negotiatedProtocol = socket.alpnProtocol || socket.npnProtocol;
          Iif (negotiatedProtocol) { // null in >=0.11.0, undefined in <0.11.0
            negotiated();
          } else {
            socket.on('secureConnect', negotiated);
          }
        });

        var negotiated = function () {
          var endpoint;
          var negotiatedProtocol = httpsRequest.socket.alpnProtocol || httpsRequest.socket.npnProtocol;
          if (negotiatedProtocol === protocol.VERSION) {
            httpsRequest.socket.emit('agentRemove');
            unbundleSocket(httpsRequest.socket);
            endpoint = new Endpoint(self._log, 'CLIENT', self._settings);
            endpoint.socket = httpsRequest.socket;
            endpoint.pipe(endpoint.socket).pipe(endpoint);
          }
          if (started) {
            // ** In the meantime, an other connection was made to the same host...
            if (endpoint) {
              // *** and it turned out to be HTTP2 and the request was multiplexed on that one, so we should close this one
              endpoint.close();
            }
            // *** otherwise, the fallback to HTTPS1 is already done.
          } else {
            if (endpoint) {
              self._log.info({ e: endpoint, server: options.host + ':' + options.port },
                             'New outgoing HTTP/2 connection');
              self.endpoints[key] = endpoint;
              self.emit(key, endpoint);
            } else {
              self.emit(key, undefined);
            }
          }
        };

        this.once(key, function(endpoint) {
          started = true;
          if (endpoint) {
            request._start(endpoint.createStream(), options);
          } else {
            request._fallback(httpsRequest);
          }
        });
      }

      return request;
    };

    Agent.prototype.get = function get(options, callback) {
      var request = this.request(options, callback);
      request.end();
      return request;
    };

    Agent.prototype.destroy = function(error) {
      if (this._httpsAgent) {
        this._httpsAgent.destroy();
      }
      for (var endpointName in this.endpoints) {
        if (this.endpoints.hasOwnProperty(endpointName)) {
          this.endpoints[endpointName].close(error);
        }
      }
    };

    function unbundleSocket(socket) {
      socket.removeAllListeners('data');
      socket.removeAllListeners('end');
      socket.removeAllListeners('readable');
      socket.removeAllListeners('close');
      socket.removeAllListeners('error');
      socket.unpipe();
      delete socket.ondata;
      delete socket.onend;
    }

    function hasValue(obj) {
      return obj === null && obj === undefined;
    }

    function hasAgentOptions(options) {
      return hasValue(options.pfx) ||
        hasValue(options.key) ||
        hasValue(options.passphrase) ||
        hasValue(options.cert) ||
        hasValue(options.ca) ||
        hasValue(options.ciphers) ||
        hasValue(options.rejectUnauthorized) ||
        hasValue(options.secureProtocol);
    }

    Object.defineProperty(Agent.prototype, 'maxSockets', {
      get: function getMaxSockets() {
        return this._httpsAgent.maxSockets;
      },
      set: function setMaxSockets(value) {
        this._httpsAgent.maxSockets = value;
      }
    });

    exports.globalAgent = new Agent();

    // OutgoingRequest class
    // ---------------------

    function OutgoingRequest() {
      OutgoingMessage.call(this);

      this._log = undefined;

      this.stream = undefined;
    }
    OutgoingRequest.prototype = Object.create(OutgoingMessage.prototype, { constructor: { value: OutgoingRequest } });

    OutgoingRequest.prototype._start = function _start(stream, options) {
      this.stream = stream;
      this.options = options;

      this._log = stream._log.child({ component: 'http' });

      for (var headerName in options.headers) {
        Eif (options.headers.hasOwnProperty(headerName)) {
          this.setHeader(headerName, options.headers[headerName]);
        }
      }
      var headers = this._headers;
      delete headers.host;

      Iif (options.auth) {
        headers.authorization = 'Basic ' + new Buffer(options.auth).toString('base64');
      }

      headers[':scheme'] = options.protocol.slice(0, -1);
      headers[':method'] = options.method;
      Eif(options.port)
      {
          headers[':authority'] = options.host + ':' + options.port;
      }
      else
      {
          headers[':authority'] = options.host;
      }
      headers[':path'] = options.path;

      this._log.info({ scheme: headers[':scheme'], method: headers[':method'],
                       authority: headers[':authority'], path: headers[':path'],
                       headers: (options.headers || {}) }, 'Sending request');
      this.stream.headers(headers);
      this.headersSent = true;

      this.emit('socket', this.stream);
      var response = new IncomingResponse(this.stream);
      response.req = this;
      response.once('ready', this.emit.bind(this, 'response', response));

      this.stream.on('promise', this._onPromise.bind(this));
    };

    OutgoingRequest.prototype._fallback = function _fallback(request) {
      request.on('response', this.emit.bind(this, 'response'));
      this.stream = this.request = request;
      this.emit('socket', this.socket);
    };

    OutgoingRequest.prototype.setPriority = function setPriority(priority) {
      if (this.stream) {
        this.stream.priority(priority);
      } else {
        this.once('socket', this.setPriority.bind(this, priority));
      }
    };

    // Overriding `EventEmitter`'s `on(event, listener)` method to forward certain subscriptions to
    // `request`. See `Server.prototype.on` for explanation.
    OutgoingRequest.prototype.on = function on(event, listener) {
      Iif (this.request && (event === 'upgrade')) {
        this.request.on(event, listener && listener.bind(this));
      } else {
        OutgoingMessage.prototype.on.call(this, event, listener);
      }
    };

    // Methods only in fallback mode
    OutgoingRequest.prototype.setNoDelay = function setNoDelay(noDelay) {
      if (this.request) {
        this.request.setNoDelay(noDelay);
      } else if (!this.stream) {
        this.on('socket', this.setNoDelay.bind(this, noDelay));
      }
    };

    OutgoingRequest.prototype.setSocketKeepAlive = function setSocketKeepAlive(enable, initialDelay) {
      if (this.request) {
        this.request.setSocketKeepAlive(enable, initialDelay);
      } else if (!this.stream) {
        this.on('socket', this.setSocketKeepAlive.bind(this, enable, initialDelay));
      }
    };

    OutgoingRequest.prototype.setTimeout = function setTimeout(timeout, callback) {
      if (this.request) {
        this.request.setTimeout(timeout, callback);
      } else if (!this.stream) {
        this.on('socket', this.setTimeout.bind(this, timeout, callback));
      }
    };

    // Aborting the request
    OutgoingRequest.prototype.abort = function abort() {
      if (this.request) {
        this.request.abort();
      } else if (this.stream) {
        this.stream.reset('CANCEL');
      } else {
        this.on('socket', this.abort.bind(this));
      }
    };

    // Receiving push promises
    OutgoingRequest.prototype._onPromise = function _onPromise(stream, headers) {
      this._log.info({ push_stream: stream.id }, 'Receiving push promise');

      var promise = new IncomingPromise(stream, headers);

      Eif (this.listeners('push').length > 0) {
        this.emit('push', promise);
      } else {
        promise.cancel();
      }
    };

    // IncomingResponse class
    // ----------------------

    function IncomingResponse(stream) {
      IncomingMessage.call(this, stream);
    }
    IncomingResponse.prototype = Object.create(IncomingMessage.prototype, { constructor: { value: IncomingResponse } });

    // [Response Header Fields](https://tools.ietf.org/html/rfc7540#section-8.1.2.4)
    // * `headers` argument: HTTP/2.0 request and response header fields carry information as a series
    //   of key-value pairs. This includes the target URI for the request, the status code for the
    //   response, as well as HTTP header fields.
    IncomingResponse.prototype._onHeaders = function _onHeaders(headers) {
      // * A single ":status" header field is defined that carries the HTTP status code field. This
      //   header field MUST be included in all responses.
      // * A client MUST treat the absence of the ":status" header field, the presence of multiple
      //   values, or an invalid value as a stream error of type PROTOCOL_ERROR.
      //   Note: currently, we do not enforce it strictly: we accept any format, and parse it as int
      // * HTTP/2.0 does not define a way to carry the reason phrase that is included in an HTTP/1.1
      //   status line.
      this.statusCode = parseInt(this._checkSpecialHeader(':status', headers[':status']));

      // * Handling regular headers.
      IncomingMessage.prototype._onHeaders.call(this, headers);

      // * Signaling that the headers arrived.
      this._log.info({ status: this.statusCode, headers: this.headers}, 'Incoming response');
      this.emit('ready');
    };

    // IncomingPromise class
    // -------------------------

    function IncomingPromise(responseStream, promiseHeaders) {
      var stream = new Readable();
      stream._read = noop;
      stream.push(null);
      stream._log = responseStream._log;

      IncomingRequest.call(this, stream);

      this._onHeaders(promiseHeaders);

      this._responseStream = responseStream;

      var response = new IncomingResponse(this._responseStream);
      response.once('ready', this.emit.bind(this, 'response', response));

      this.stream.on('promise', this._onPromise.bind(this));
    }
    IncomingPromise.prototype = Object.create(IncomingRequest.prototype, { constructor: { value: IncomingPromise } });

    IncomingPromise.prototype.cancel = function cancel() {
      this._responseStream.reset('CANCEL');
    };

    IncomingPromise.prototype.setPriority = function setPriority(priority) {
      this._responseStream.priority(priority);
    };

    IncomingPromise.prototype._onPromise = OutgoingRequest.prototype._onPromise;