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      1 /*
      2  * libjingle
      3  * Copyright 2012, Google Inc.
      4  *
      5  * Redistribution and use in source and binary forms, with or without
      6  * modification, are permitted provided that the following conditions are met:
      7  *
      8  *  1. Redistributions of source code must retain the above copyright notice,
      9  *     this list of conditions and the following disclaimer.
     10  *  2. Redistributions in binary form must reproduce the above copyright notice,
     11  *     this list of conditions and the following disclaimer in the documentation
     12  *     and/or other materials provided with the distribution.
     13  *  3. The name of the author may not be used to endorse or promote products
     14  *     derived from this software without specific prior written permission.
     15  *
     16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
     17  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
     18  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
     19  * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     20  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     21  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
     22  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
     23  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
     24  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
     25  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     26  */
     27 
     28 #ifndef TALK_APP_WEBRTC_DATACHANNEL_H_
     29 #define TALK_APP_WEBRTC_DATACHANNEL_H_
     30 
     31 #include <deque>
     32 #include <string>
     33 
     34 #include "talk/app/webrtc/datachannelinterface.h"
     35 #include "talk/app/webrtc/proxy.h"
     36 #include "talk/media/base/mediachannel.h"
     37 #include "talk/session/media/channel.h"
     38 #include "webrtc/base/messagehandler.h"
     39 #include "webrtc/base/scoped_ref_ptr.h"
     40 #include "webrtc/base/sigslot.h"
     41 
     42 namespace webrtc {
     43 
     44 class DataChannel;
     45 
     46 class DataChannelProviderInterface {
     47  public:
     48   // Sends the data to the transport.
     49   virtual bool SendData(const cricket::SendDataParams& params,
     50                         const rtc::Buffer& payload,
     51                         cricket::SendDataResult* result) = 0;
     52   // Connects to the transport signals.
     53   virtual bool ConnectDataChannel(DataChannel* data_channel) = 0;
     54   // Disconnects from the transport signals.
     55   virtual void DisconnectDataChannel(DataChannel* data_channel) = 0;
     56   // Adds the data channel SID to the transport for SCTP.
     57   virtual void AddSctpDataStream(uint32 sid) = 0;
     58   // Removes the data channel SID from the transport for SCTP.
     59   virtual void RemoveSctpDataStream(uint32 sid) = 0;
     60   // Returns true if the transport channel is ready to send data.
     61   virtual bool ReadyToSendData() const = 0;
     62 
     63  protected:
     64   virtual ~DataChannelProviderInterface() {}
     65 };
     66 
     67 struct InternalDataChannelInit : public DataChannelInit {
     68   enum OpenHandshakeRole {
     69     kOpener,
     70     kAcker,
     71     kNone
     72   };
     73   // The default role is kOpener because the default |negotiated| is false.
     74   InternalDataChannelInit() : open_handshake_role(kOpener) {}
     75   explicit InternalDataChannelInit(const DataChannelInit& base)
     76       : DataChannelInit(base), open_handshake_role(kOpener) {
     77     // If the channel is externally negotiated, do not send the OPEN message.
     78     if (base.negotiated) {
     79       open_handshake_role = kNone;
     80     }
     81   }
     82 
     83   OpenHandshakeRole open_handshake_role;
     84 };
     85 
     86 // DataChannel is a an implementation of the DataChannelInterface based on
     87 // libjingle's data engine. It provides an implementation of unreliable or
     88 // reliabledata channels. Currently this class is specifically designed to use
     89 // both RtpDataEngine and SctpDataEngine.
     90 
     91 // DataChannel states:
     92 // kConnecting: The channel has been created the transport might not yet be
     93 //              ready.
     94 // kOpen: The channel have a local SSRC set by a call to UpdateSendSsrc
     95 //        and a remote SSRC set by call to UpdateReceiveSsrc and the transport
     96 //        has been writable once.
     97 // kClosing: DataChannelInterface::Close has been called or UpdateReceiveSsrc
     98 //           has been called with SSRC==0
     99 // kClosed: Both UpdateReceiveSsrc and UpdateSendSsrc has been called with
    100 //          SSRC==0.
    101 class DataChannel : public DataChannelInterface,
    102                     public sigslot::has_slots<>,
    103                     public rtc::MessageHandler {
    104  public:
    105   static rtc::scoped_refptr<DataChannel> Create(
    106       DataChannelProviderInterface* provider,
    107       cricket::DataChannelType dct,
    108       const std::string& label,
    109       const InternalDataChannelInit& config);
    110 
    111   virtual void RegisterObserver(DataChannelObserver* observer);
    112   virtual void UnregisterObserver();
    113 
    114   virtual std::string label() const { return label_; }
    115   virtual bool reliable() const;
    116   virtual bool ordered() const { return config_.ordered; }
    117   virtual uint16 maxRetransmitTime() const {
    118     return config_.maxRetransmitTime;
    119   }
    120   virtual uint16 maxRetransmits() const {
    121     return config_.maxRetransmits;
    122   }
    123   virtual std::string protocol() const { return config_.protocol; }
    124   virtual bool negotiated() const { return config_.negotiated; }
    125   virtual int id() const { return config_.id; }
    126   virtual uint64 buffered_amount() const;
    127   virtual void Close();
    128   virtual DataState state() const { return state_; }
    129   virtual bool Send(const DataBuffer& buffer);
    130 
    131   // rtc::MessageHandler override.
    132   virtual void OnMessage(rtc::Message* msg);
    133 
    134   // Called if the underlying data engine is closing.
    135   void OnDataEngineClose();
    136 
    137   // Called when the channel's ready to use.  That can happen when the
    138   // underlying DataMediaChannel becomes ready, or when this channel is a new
    139   // stream on an existing DataMediaChannel, and we've finished negotiation.
    140   void OnChannelReady(bool writable);
    141 
    142   // Sigslots from cricket::DataChannel
    143   void OnDataReceived(cricket::DataChannel* channel,
    144                       const cricket::ReceiveDataParams& params,
    145                       const rtc::Buffer& payload);
    146 
    147   // The remote peer request that this channel should be closed.
    148   void RemotePeerRequestClose();
    149 
    150   // The following methods are for SCTP only.
    151 
    152   // Sets the SCTP sid and adds to transport layer if not set yet. Should only
    153   // be called once.
    154   void SetSctpSid(int sid);
    155   // Called when the transport channel is created.
    156   void OnTransportChannelCreated();
    157 
    158   // The following methods are for RTP only.
    159 
    160   // Set the SSRC this channel should use to send data on the
    161   // underlying data engine. |send_ssrc| == 0 means that the channel is no
    162   // longer part of the session negotiation.
    163   void SetSendSsrc(uint32 send_ssrc);
    164   // Set the SSRC this channel should use to receive data from the
    165   // underlying data engine.
    166   void SetReceiveSsrc(uint32 receive_ssrc);
    167 
    168   cricket::DataChannelType data_channel_type() const {
    169     return data_channel_type_;
    170   }
    171 
    172  protected:
    173   DataChannel(DataChannelProviderInterface* client,
    174               cricket::DataChannelType dct,
    175               const std::string& label);
    176   virtual ~DataChannel();
    177 
    178  private:
    179   // A packet queue which tracks the total queued bytes. Queued packets are
    180   // owned by this class.
    181   class PacketQueue {
    182    public:
    183     PacketQueue();
    184     ~PacketQueue();
    185 
    186     size_t byte_count() const {
    187       return byte_count_;
    188     }
    189 
    190     bool Empty() const;
    191 
    192     DataBuffer* Front();
    193 
    194     void Pop();
    195 
    196     void Push(DataBuffer* packet);
    197 
    198     void Clear();
    199 
    200     void Swap(PacketQueue* other);
    201 
    202    private:
    203     std::deque<DataBuffer*> packets_;
    204     size_t byte_count_;
    205   };
    206 
    207   bool Init(const InternalDataChannelInit& config);
    208   void DoClose();
    209   void UpdateState();
    210   void SetState(DataState state);
    211   void DisconnectFromTransport();
    212 
    213   void DeliverQueuedReceivedData();
    214 
    215   void SendQueuedDataMessages();
    216   bool SendDataMessage(const DataBuffer& buffer);
    217   bool QueueSendDataMessage(const DataBuffer& buffer);
    218 
    219   void SendQueuedControlMessages();
    220   void QueueControlMessage(const rtc::Buffer& buffer);
    221   bool SendControlMessage(const rtc::Buffer& buffer);
    222 
    223   std::string label_;
    224   InternalDataChannelInit config_;
    225   DataChannelObserver* observer_;
    226   DataState state_;
    227   cricket::DataChannelType data_channel_type_;
    228   DataChannelProviderInterface* provider_;
    229   bool waiting_for_open_ack_;
    230   bool was_ever_writable_;
    231   bool connected_to_provider_;
    232   bool send_ssrc_set_;
    233   bool receive_ssrc_set_;
    234   uint32 send_ssrc_;
    235   uint32 receive_ssrc_;
    236   // Control messages that always have to get sent out before any queued
    237   // data.
    238   PacketQueue queued_control_data_;
    239   PacketQueue queued_received_data_;
    240   PacketQueue queued_send_data_;
    241 };
    242 
    243 class DataChannelFactory {
    244  public:
    245   virtual rtc::scoped_refptr<DataChannel> CreateDataChannel(
    246       const std::string& label,
    247       const InternalDataChannelInit* config) = 0;
    248 
    249  protected:
    250   virtual ~DataChannelFactory() {}
    251 };
    252 
    253 // Define proxy for DataChannelInterface.
    254 BEGIN_PROXY_MAP(DataChannel)
    255   PROXY_METHOD1(void, RegisterObserver, DataChannelObserver*)
    256   PROXY_METHOD0(void, UnregisterObserver)
    257   PROXY_CONSTMETHOD0(std::string, label)
    258   PROXY_CONSTMETHOD0(bool, reliable)
    259   PROXY_CONSTMETHOD0(bool, ordered)
    260   PROXY_CONSTMETHOD0(uint16, maxRetransmitTime)
    261   PROXY_CONSTMETHOD0(uint16, maxRetransmits)
    262   PROXY_CONSTMETHOD0(std::string, protocol)
    263   PROXY_CONSTMETHOD0(bool, negotiated)
    264   PROXY_CONSTMETHOD0(int, id)
    265   PROXY_CONSTMETHOD0(DataState, state)
    266   PROXY_CONSTMETHOD0(uint64, buffered_amount)
    267   PROXY_METHOD0(void, Close)
    268   PROXY_METHOD1(bool, Send, const DataBuffer&)
    269 END_PROXY()
    270 
    271 }  // namespace webrtc
    272 
    273 #endif  // TALK_APP_WEBRTC_DATACHANNEL_H_
    274