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      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_
    166