net/websockets/websocket_basic_stream.h

   1 // Copyright 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef NET_WEBSOCKETS_WEBSOCKET_BASIC_STREAM_H_
   6 #define NET_WEBSOCKETS_WEBSOCKET_BASIC_STREAM_H_
   7
   8 #include <string>
   9
  10 #include "base/callback.h"
  11 #include "base/memory/ref_counted.h"
  12 #include "base/memory/scoped_ptr.h"
  13 #include "base/memory/scoped_vector.h"
  14 #include "net/websockets/websocket_frame_parser.h"
  15 #include "net/websockets/websocket_stream.h"
  16
  17 namespace net {
  18
  19 class ClientSocketHandle;
  20 class DrainableIOBuffer;
  21 class GrowableIOBuffer;
  22 class IOBufferWithSize;
  23 struct WebSocketFrame;
  24 struct WebSocketFrameChunk;
  25
  26 // Implementation of WebSocketStream for non-multiplexed ws:// connections (or
  27 // the physical side of a multiplexed ws:// connection).
  28 class NET_EXPORT_PRIVATE WebSocketBasicStream : public WebSocketStream {
  29  public:
  30   typedef WebSocketMaskingKey (*WebSocketMaskingKeyGeneratorFunction)();
  31
  32   // This class should not normally be constructed directly; see
  33   // WebSocketStream::CreateAndConnectStream() and
  34   // WebSocketBasicHandshakeStream::Upgrade().
  35   WebSocketBasicStream(
  36       scoped_ptr<ClientSocketHandle> connection,
  37       const scoped_refptr<GrowableIOBuffer>& http_read_buffer,
  38       const std::string& sub_protocol,
  39       const std::string& extensions);
  40
  41   // The destructor has to make sure the connection is closed when we finish so
  42   // that it does not get returned to the pool.
  43   virtual ~WebSocketBasicStream();
  44
  45   // WebSocketStream implementation.
  46   virtual int ReadFrames(ScopedVector<WebSocketFrame>* frames,
  47                          const CompletionCallback& callback) OVERRIDE;
  48
  49   virtual int WriteFrames(ScopedVector<WebSocketFrame>* frames,
  50                           const CompletionCallback& callback) OVERRIDE;
  51
  52   virtual void Close() OVERRIDE;
  53
  54   virtual std::string GetSubProtocol() const OVERRIDE;
  55
  56   virtual std::string GetExtensions() const OVERRIDE;
  57
  58   ////////////////////////////////////////////////////////////////////////////
  59   // Methods for testing only.
  60
  61   static scoped_ptr<WebSocketBasicStream> CreateWebSocketBasicStreamForTesting(
  62       scoped_ptr<ClientSocketHandle> connection,
  63       const scoped_refptr<GrowableIOBuffer>& http_read_buffer,
  64       const std::string& sub_protocol,
  65       const std::string& extensions,
  66       WebSocketMaskingKeyGeneratorFunction key_generator_function);
  67
  68  private:
  69   // Returns OK or calls |callback| when the |buffer| is fully drained or
  70   // something has failed.
  71   int WriteEverything(const scoped_refptr<DrainableIOBuffer>& buffer,
  72                       const CompletionCallback& callback);
  73
  74   // Wraps the |callback| to continue writing until everything has been written.
  75   void OnWriteComplete(const scoped_refptr<DrainableIOBuffer>& buffer,
  76                        const CompletionCallback& callback,
  77                        int result);
  78
  79   // Attempts to parse the output of a read as WebSocket frames. On success,
  80   // returns OK and places the frame(s) in |frames|.
  81   int HandleReadResult(int result, ScopedVector<WebSocketFrame>* frames);
  82
  83   // Converts the chunks in |frame_chunks| into frames and writes them to
  84   // |frames|. |frame_chunks| is destroyed in the process. Returns
  85   // ERR_WS_PROTOCOL_ERROR if an invalid chunk was found. If one or more frames
  86   // was added to |frames|, then returns OK, otherwise returns ERR_IO_PENDING.
  87   int ConvertChunksToFrames(ScopedVector<WebSocketFrameChunk>* frame_chunks,
  88                             ScopedVector<WebSocketFrame>* frames);
  89
  90   // Converts a |chunk| to a |frame|. |*frame| should be NULL on entry to this
  91   // method. If |chunk| is an incomplete control frame, or an empty middle
  92   // frame, then |*frame| may still be NULL on exit. If an invalid control frame
  93   // is found, returns ERR_WS_PROTOCOL_ERROR and the stream is no longer
  94   // usable. Otherwise returns OK (even if frame is still NULL).
  95   int ConvertChunkToFrame(scoped_ptr<WebSocketFrameChunk> chunk,
  96                           scoped_ptr<WebSocketFrame>* frame);
  97
  98   // Creates a frame based on the value of |is_final_chunk|, |data| and
  99   // |current_frame_header_|. Clears |current_frame_header_| if |is_final_chunk|
 100   // is true. |data| may be NULL if the frame has an empty payload. A frame in
 101   // the middle of a message with no data is not useful; in this case the
 102   // returned frame will be NULL. Otherwise, |current_frame_header_->opcode| is
 103   // set to Continuation after use if it was Text or Binary, in accordance with
 104   // WebSocket RFC6455 section 5.4.
 105   scoped_ptr<WebSocketFrame> CreateFrame(
 106       bool is_final_chunk,
 107       const scoped_refptr<IOBufferWithSize>& data);
 108
 109   // Adds |data_buffer| to the end of |incomplete_control_frame_body_|, applying
 110   // bounds checks.
 111   void AddToIncompleteControlFrameBody(
 112       const scoped_refptr<IOBufferWithSize>& data_buffer);
 113
 114   // Called when a read completes. Parses the result and (unless no complete
 115   // header has been received) calls |callback|.
 116   void OnReadComplete(ScopedVector<WebSocketFrame>* frames,
 117                       const CompletionCallback& callback,
 118                       int result);
 119
 120   // Storage for pending reads. All active WebSockets spend all the time with a
 121   // call to ReadFrames() pending, so there is no benefit in trying to share
 122   // this between sockets.
 123   scoped_refptr<IOBufferWithSize> read_buffer_;
 124
 125   // The connection, wrapped in a ClientSocketHandle so that we can prevent it
 126   // from being returned to the pool.
 127   scoped_ptr<ClientSocketHandle> connection_;
 128
 129   // Frame header for the frame currently being received. Only non-NULL while we
 130   // are processing the frame. If the frame arrives in multiple chunks, it can
 131   // remain non-NULL until additional chunks arrive. If the header of the frame
 132   // was invalid, this is set to NULL, the channel is failed, and subsequent
 133   // chunks of the same frame will be ignored.
 134   scoped_ptr<WebSocketFrameHeader> current_frame_header_;
 135
 136   // Although it should rarely happen in practice, a control frame can arrive
 137   // broken into chunks. This variable provides storage for a partial control
 138   // frame until the rest arrives. It will be NULL the rest of the time.
 139   scoped_refptr<GrowableIOBuffer> incomplete_control_frame_body_;
 140
 141   // Only used during handshake. Some data may be left in this buffer after the
 142   // handshake, in which case it will be picked up during the first call to
 143   // ReadFrames(). The type is GrowableIOBuffer for compatibility with
 144   // net::HttpStreamParser, which is used to parse the handshake.
 145   scoped_refptr<GrowableIOBuffer> http_read_buffer_;
 146
 147   // This keeps the current parse state (including any incomplete headers) and
 148   // parses frames.
 149   WebSocketFrameParser parser_;
 150
 151   // The negotated sub-protocol, or empty for none.
 152   const std::string sub_protocol_;
 153
 154   // The extensions negotiated with the remote server.
 155   const std::string extensions_;
 156
 157   // This can be overridden in tests to make the output deterministic. We don't
 158   // use a Callback here because a function pointer is faster and good enough
 159   // for our purposes.
 160   WebSocketMaskingKeyGeneratorFunction generate_websocket_masking_key_;
 161 };
 162
 163 }  // namespace net
 164
 165 #endif  // NET_WEBSOCKETS_WEBSOCKET_BASIC_STREAM_H_