// Copyright 2013 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 NET_WEBSOCKETS_WEBSOCKET_BASIC_STREAM_H_
#define NET_WEBSOCKETS_WEBSOCKET_BASIC_STREAM_H_
#include <string>
#include "base/callback.h"
#include "base/memory/ref_counted.h"
#include "base/memory/scoped_ptr.h"
#include "base/memory/scoped_vector.h"
#include "net/websockets/websocket_frame_parser.h"
#include "net/websockets/websocket_stream.h"
namespace net {
class ClientSocketHandle;
class DrainableIOBuffer;
class GrowableIOBuffer;
class IOBufferWithSize;
struct WebSocketFrame;
struct WebSocketFrameChunk;
// Implementation of WebSocketStream for non-multiplexed ws:// connections (or
// the physical side of a multiplexed ws:// connection).
class NET_EXPORT_PRIVATE WebSocketBasicStream : public WebSocketStream {
public:
typedef WebSocketMaskingKey (*WebSocketMaskingKeyGeneratorFunction)();
// This class should not normally be constructed directly; see
// WebSocketStream::CreateAndConnectStream() and
// WebSocketBasicHandshakeStream::Upgrade().
WebSocketBasicStream(
scoped_ptr<ClientSocketHandle> connection,
const scoped_refptr<GrowableIOBuffer>& http_read_buffer,
const std::string& sub_protocol,
const std::string& extensions);
// The destructor has to make sure the connection is closed when we finish so
// that it does not get returned to the pool.
virtual ~WebSocketBasicStream();
// WebSocketStream implementation.
virtual int ReadFrames(ScopedVector<WebSocketFrame>* frames,
const CompletionCallback& callback) OVERRIDE;
virtual int WriteFrames(ScopedVector<WebSocketFrame>* frames,
const CompletionCallback& callback) OVERRIDE;
virtual void Close() OVERRIDE;
virtual std::string GetSubProtocol() const OVERRIDE;
virtual std::string GetExtensions() const OVERRIDE;
////////////////////////////////////////////////////////////////////////////
// Methods for testing only.
static scoped_ptr<WebSocketBasicStream> CreateWebSocketBasicStreamForTesting(
scoped_ptr<ClientSocketHandle> connection,
const scoped_refptr<GrowableIOBuffer>& http_read_buffer,
const std::string& sub_protocol,
const std::string& extensions,
WebSocketMaskingKeyGeneratorFunction key_generator_function);
private:
// Returns OK or calls |callback| when the |buffer| is fully drained or
// something has failed.
int WriteEverything(const scoped_refptr<DrainableIOBuffer>& buffer,
const CompletionCallback& callback);
// Wraps the |callback| to continue writing until everything has been written.
void OnWriteComplete(const scoped_refptr<DrainableIOBuffer>& buffer,
const CompletionCallback& callback,
int result);
// Attempts to parse the output of a read as WebSocket frames. On success,
// returns OK and places the frame(s) in |frames|.
int HandleReadResult(int result, ScopedVector<WebSocketFrame>* frames);
// Converts the chunks in |frame_chunks| into frames and writes them to
// |frames|. |frame_chunks| is destroyed in the process. Returns
// ERR_WS_PROTOCOL_ERROR if an invalid chunk was found. If one or more frames
// was added to |frames|, then returns OK, otherwise returns ERR_IO_PENDING.
int ConvertChunksToFrames(ScopedVector<WebSocketFrameChunk>* frame_chunks,
ScopedVector<WebSocketFrame>* frames);
// Converts a |chunk| to a |frame|. |*frame| should be NULL on entry to this
// method. If |chunk| is an incomplete control frame, or an empty middle
// frame, then |*frame| may still be NULL on exit. If an invalid control frame
// is found, returns ERR_WS_PROTOCOL_ERROR and the stream is no longer
// usable. Otherwise returns OK (even if frame is still NULL).
int ConvertChunkToFrame(scoped_ptr<WebSocketFrameChunk> chunk,
scoped_ptr<WebSocketFrame>* frame);
// Creates a frame based on the value of |is_final_chunk|, |data| and
// |current_frame_header_|. Clears |current_frame_header_| if |is_final_chunk|
// is true. |data| may be NULL if the frame has an empty payload. A frame in
// the middle of a message with no data is not useful; in this case the
// returned frame will be NULL. Otherwise, |current_frame_header_->opcode| is
// set to Continuation after use if it was Text or Binary, in accordance with
// WebSocket RFC6455 section 5.4.
scoped_ptr<WebSocketFrame> CreateFrame(
bool is_final_chunk,
const scoped_refptr<IOBufferWithSize>& data);
// Adds |data_buffer| to the end of |incomplete_control_frame_body_|, applying
// bounds checks.
void AddToIncompleteControlFrameBody(
const scoped_refptr<IOBufferWithSize>& data_buffer);
// Called when a read completes. Parses the result and (unless no complete
// header has been received) calls |callback|.
void OnReadComplete(ScopedVector<WebSocketFrame>* frames,
const CompletionCallback& callback,
int result);
// Storage for pending reads. All active WebSockets spend all the time with a
// call to ReadFrames() pending, so there is no benefit in trying to share
// this between sockets.
scoped_refptr<IOBufferWithSize> read_buffer_;
// The connection, wrapped in a ClientSocketHandle so that we can prevent it
// from being returned to the pool.
scoped_ptr<ClientSocketHandle> connection_;
// Frame header for the frame currently being received. Only non-NULL while we
// are processing the frame. If the frame arrives in multiple chunks, it can
// remain non-NULL until additional chunks arrive. If the header of the frame
// was invalid, this is set to NULL, the channel is failed, and subsequent
// chunks of the same frame will be ignored.
scoped_ptr<WebSocketFrameHeader> current_frame_header_;
// Although it should rarely happen in practice, a control frame can arrive
// broken into chunks. This variable provides storage for a partial control
// frame until the rest arrives. It will be NULL the rest of the time.
scoped_refptr<GrowableIOBuffer> incomplete_control_frame_body_;
// Only used during handshake. Some data may be left in this buffer after the
// handshake, in which case it will be picked up during the first call to
// ReadFrames(). The type is GrowableIOBuffer for compatibility with
// net::HttpStreamParser, which is used to parse the handshake.
scoped_refptr<GrowableIOBuffer> http_read_buffer_;
// This keeps the current parse state (including any incomplete headers) and
// parses frames.
WebSocketFrameParser parser_;
// The negotated sub-protocol, or empty for none.
const std::string sub_protocol_;
// The extensions negotiated with the remote server.
const std::string extensions_;
// This can be overridden in tests to make the output deterministic. We don't
// use a Callback here because a function pointer is faster and good enough
// for our purposes.
WebSocketMaskingKeyGeneratorFunction generate_websocket_masking_key_;
};
} // namespace net
#endif // NET_WEBSOCKETS_WEBSOCKET_BASIC_STREAM_H_