Add simple WebSocket server implementation.

remoting/host/websocket_connection.h

Index: remoting/host/websocket_connection.h
diff --git a/remoting/host/websocket_connection.h b/remoting/host/websocket_connection.h
new file mode 100644
index 0000000000000000000000000000000000000000..25c41dca5b7334757352314ff6c7ce2a0cf8cfc6
--- /dev/null
+++ b/remoting/host/websocket_connection.h
@@ -0,0 +1,140 @@
+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef REMOTING_HOST_WEBSOCKET_CONNECTION_H_
+#define REMOTING_HOST_WEBSOCKET_CONNECTION_H_
+
+#include <string>
+
+#include "base/callback.h"
+#include "base/memory/ref_counted.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/memory/weak_ptr.h"
+#include "remoting/base/socket_reader.h"
+#include "remoting/protocol/buffered_socket_writer.h"
+
+namespace net {
+class StreamSocket;
+}  // namespace net
+
+namespace remoting {
+
+class WebsocketConnection {
+ public:
+  typedef base::Callback<void (bool connected)> ConnectedCallback;
+  class Delegate {
+   public:
+    virtual void OnWebsocketMessage(const std::string& message) = 0;
+    virtual void OnWebsocketClosed() = 0;
+  };
+
+  WebsocketConnection();
+  virtual ~WebsocketConnection();
+
+  // Initialize WebSocket connection for the specified |socket|.
+  // |connected_callback| is called after handshake headers have been received
+  // from the client and parsed or when the connection terminated.
+  void Start(scoped_ptr<net::StreamSocket> socket,
+             ConnectedCallback connected_callback);
+
+  // Connection parameters received in the header. Valid only after
+  // |connected_callback| specified in Start() is called with true.

[Wez, 2012/11/20 05:44:09]

nit: "Valid only after |connected_callback_| has been called with |connected|
true." or "Valid only once Start() has successfully completed."

[Sergey Ulanov, 2012/11/21 01:40:24]

Done.

+  const std::string& request_path() { return request_path_; }
+  const std::string& request_host() { return request_host_; }
+  const std::string& origin() { return origin_; }
+
+  // Accept or Reject new connection. Accept() or Reject() must be called once
+  // after Start() completes successfully, i.e. after |connected_callback| is
+  // called with connected=true.

[Wez, 2012/11/20 05:44:09]

nit: If you rephrase the comment on start to mention specifically that
|connected|=true iff Start() "completes successfully" then I think you can just
refer to Start completing successfully here, without the clarification.

[Sergey Ulanov, 2012/11/21 01:40:24]

Done.

+  void Accept(Delegate* delegate);
+  void Reject();
+
+  // Maximum size of incoming messages. Connection is terminated when the remote
+  // end tries to send a message bigger than the specified value. Can be set
+  // to 0 (default), which indicates that message size is unlimited.

[Wez, 2012/11/20 05:44:09]

nit: "Sets the maximum incoming message size to allow.  The connection will be
closed if a message exceeding this size is received. |size| may be zero to allow
any message size".

What's the default size?

[Sergey Ulanov, 2012/11/21 01:40:24]

Done.

+  void set_maximum_message_size(uint64 size);
+
+  // Send the specified text message. Sending data messages is not supported.
+  void SendText(const std::string& text);
+
+  // Closes the connection sending Close frame to the client if necessary.

[Wez, 2012/11/20 05:44:09]

nit: "Closes the connection and sends a Close frame ..."

[Sergey Ulanov, 2012/11/21 01:40:24]

Done.

+  void Close();
+
+ private:
+  enum State {
+    READING_HEADERS,
+    HEADERS_READ,
+    ACCEPTED,
+    CLOSED,
+  };
+
+  enum WebsocketOpcode {
+    OPCODE_CONTINUATION = 0,
+    OPCODE_TEXT_FRAME = 1,
+    OPCODE_BINARY_FRAME = 2,
+    OPCODE_CLOSE = 8,
+    OPCODE_PING = 9,
+    OPCODE_PONG = 10,
+  };
+
+  // Closes the socket after protocol error and calls

[Wez, 2012/11/20 05:44:09]

nit: Suggest "Closes the socket in response to a protocol error, and notifies
Delegate::OnWebsocketClosed()."

[Sergey Ulanov, 2012/11/21 01:40:24]

Done.

+  // Delegate::OnWebsocketClosed().
+  void CloseOnError();
+
+  // Result handler for |reader_|.
+  void OnSocketReadResult(scoped_refptr<net::IOBuffer> data, int size);
+
+  // Parses websocket headers in |header_| and returns false when headers are
+  // invalid.
+  bool ParseHeaders();
+
+  // Parse incoming data in |received_data_| and dispatches delegate calls when

[Wez, 2012/11/20 05:44:09]

nit: Parse -> Parses

[Sergey Ulanov, 2012/11/21 01:40:24]

Done.

[Sergey Ulanov, 2012/11/21 01:40:24]

Done.

+  // a new message is received.
+  void ProcessData();
+
+  // Error handler for |writer_|.
+  void OnSocketWriteError(int error);
+
+  // Sends outgoing frame with the specified |opcode| and |payload|.
+  void SendFragment(WebsocketOpcode opcode,
+                    const char* payload, int payload_length);

[Wez, 2012/11/20 05:44:09]

nit: Why not just pass payload as std::string or base::StringPiece?

[Sergey Ulanov, 2012/11/21 01:40:24]

Done.

+
+  // Unmasks fragment |payload| using specified |mask|
+  void UnmaskPayload(const char* mask, char* payload, int payload_length);
+
+  scoped_ptr<net::StreamSocket> socket_;
+  ConnectedCallback connected_callback_;
+  Delegate* delegate_;
+
+  uint64 maximum_message_size_;
+
+  SocketReader reader_;
+  protocol::BufferedSocketWriter writer_;
+
+  State state_;
+
+  std::string headers_;
+
+  // Header fields. Set in ParseHeaders().
+  std::string request_path_;
+  std::string request_host_;
+  std::string origin_;
+  std::string websocket_key_;
+
+  // Raw data that has been received but hasn't been parsed.
+  std::string received_data_;
+
+  // When receiving a fragmented message |receiving_message_| is set to true and
+  // |current_message_| contains the fragments that we've already received.
+  bool receiving_message_;
+  std::string current_message_;
+
+  base::WeakPtrFactory<WebsocketConnection> weak_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(WebsocketConnection);
+};
+
+}  // namespace remoting
+
+#endif  // REMOTING_HOST_WEBSOCKET_CONNECTION_H_