Reland of: Separating SCTP code from BaseChannel/MediaChannel.

webrtc/api/webrtcsession.h

Index: webrtc/api/webrtcsession.h
diff --git a/webrtc/api/webrtcsession.h b/webrtc/api/webrtcsession.h
index ef31560509879ec3abeb4705ee1c20a0ecb1cc72..e346112cba3d9d6c2e8b7efd8c551a2b0b156d0a 100644
--- a/webrtc/api/webrtcsession.h
+++ b/webrtc/api/webrtcsession.h
@@ -22,6 +22,7 @@
 #include "webrtc/api/peerconnectioninterface.h"
 #include "webrtc/api/statstypes.h"
 #include "webrtc/base/constructormagic.h"
+#include "webrtc/base/optional.h"
 #include "webrtc/base/sigslot.h"
 #include "webrtc/base/sslidentity.h"
 #include "webrtc/base/thread.h"
@@ -37,7 +38,9 @@
 namespace cricket {
 
 class ChannelManager;
-class DataChannel;
+class RtpDataChannel;
+class SctpTransportInternal;
+class SctpTransportInternalFactory;
 class StatsReport;
 class VideoChannel;
 class VoiceChannel;
@@ -67,8 +70,8 @@ extern const char kSdpWithoutIceUfragPwd[];
 extern const char kSdpWithoutSdesAndDtlsDisabled[];
 extern const char kSessionError[];
 extern const char kSessionErrorDesc[];
-extern const char kDtlsSetupFailureRtp[];
-extern const char kDtlsSetupFailureRtcp[];
+extern const char kDtlsSrtpSetupFailureRtp[];
+extern const char kDtlsSrtpSetupFailureRtcp[];
 extern const char kEnableBundleFailed[];
 
 // Maximum number of received video streams that will be processed by webrtc
@@ -158,13 +161,15 @@ class WebRtcSession :
     ERROR_TRANSPORT = 2,  // transport error of some kind
   };
 
+  // |sctp_factory| may be null, in which case SCTP is treated as unsupported.
   WebRtcSession(
       webrtc::MediaControllerInterface* media_controller,
       rtc::Thread* network_thread,
       rtc::Thread* worker_thread,
       rtc::Thread* signaling_thread,
       cricket::PortAllocator* port_allocator,
-      std::unique_ptr<cricket::TransportController> transport_controller);
+      std::unique_ptr<cricket::TransportController> transport_controller,
+      std::unique_ptr<cricket::SctpTransportInternalFactory> sctp_factory);
   virtual ~WebRtcSession();
 
   // These are const to allow them to be called from const methods.
@@ -199,26 +204,34 @@ class WebRtcSession :
     ice_observer_ = observer;
   }
 
+  // Exposed for stats collecting.
   virtual cricket::VoiceChannel* voice_channel() {
     return voice_channel_.get();
   }
   virtual cricket::VideoChannel* video_channel() {
     return video_channel_.get();
   }
-  virtual cricket::DataChannel* data_channel() {
-    return data_channel_.get();
+  // Only valid when using deprecated RTP data channels.
+  virtual cricket::RtpDataChannel* rtp_data_channel() {
+    return rtp_data_channel_.get();
+  }
+  virtual rtc::Optional<std::string> sctp_content_name() const {
+    return sctp_content_name_;
+  }
+  virtual rtc::Optional<std::string> sctp_transport_name() const {
+    return sctp_transport_name_;
   }
 
   cricket::BaseChannel* GetChannel(const std::string& content_name);
 
   cricket::SecurePolicy SdesPolicy() const;
 
-  // Get current ssl role from transport.
-  bool GetSslRole(const std::string& transport_name, rtc::SSLRole* role);
-
-  // Get current SSL role for this channel's transport.
-  // If |transport| is null, returns false.
-  bool GetSslRole(const cricket::BaseChannel* channel, rtc::SSLRole* role);
+  // Get current SSL role used by SCTP's underlying transport.
+  bool GetSctpSslRole(rtc::SSLRole* role);
+  // Get SSL role for an arbitrary m= section (handles bundling correctly).
+  // TODO(deadbeef): This is only used internally by the session description
+  // factory, it shouldn't really be public).
+  bool GetSslRole(const std::string& content_name, rtc::SSLRole* role);
 
   void CreateOffer(
       CreateSessionDescriptionObserver* observer,
@@ -232,6 +245,7 @@ class WebRtcSession :
   // The ownership of |desc| will be transferred after this call.
   bool SetRemoteDescription(SessionDescriptionInterface* desc,
                             std::string* err_desc);
+
   bool ProcessIceMessage(const IceCandidateInterface* ice_candidate);
 
   bool RemoveRemoteIceCandidates(
@@ -326,7 +340,7 @@ class WebRtcSession :
   // WebRTCSessionDescriptionFactory. Should happen before setLocalDescription.
   void OnCertificateReady(
       const rtc::scoped_refptr<rtc::RTCCertificate>& certificate);
-  void OnDtlsSetupFailure(cricket::BaseChannel*, bool rtcp);
+  void OnDtlsSrtpSetupFailure(cricket::BaseChannel*, bool rtcp);
 
   // For unit test.
   bool waiting_for_certificate_for_testing() const;
@@ -338,8 +352,9 @@ class WebRtcSession :
     transport_controller_->SetMetricsObserver(metrics_observer);
   }
 
-  // Called when voice_channel_, video_channel_ and data_channel_ are created
-  // and destroyed. As a result of, for example, setting a new description.
+  // Called when voice_channel_, video_channel_ and
+  // rtp_data_channel_/sctp_transport_ are created and destroyed. As a result
+  // of, for example, setting a new description.
   sigslot::signal0<> SignalVoiceChannelCreated;
   sigslot::signal0<> SignalVoiceChannelDestroyed;
   sigslot::signal0<> SignalVideoChannelCreated;
@@ -397,6 +412,7 @@ class WebRtcSession :
   bool PushdownMediaDescription(cricket::ContentAction action,
                                 cricket::ContentSource source,
                                 std::string* error_desc);
+  bool PushdownSctpParameters_n(cricket::ContentSource source);
 
   bool PushdownTransportDescription(cricket::ContentSource source,
                                     cricket::ContentAction action,
@@ -461,11 +477,24 @@ class WebRtcSession :
   std::unique_ptr<SessionStats> GetStats_n(
       const ChannelNamePairs& channel_name_pairs);
 
-  // Listens to SCTP CONTROL messages on unused SIDs and process them as OPEN
-  // messages.
-  void OnDataChannelMessageReceived(cricket::DataChannel* channel,
-                                    const cricket::ReceiveDataParams& params,
-                                    const rtc::CopyOnWriteBuffer& payload);
+  bool CreateSctpTransport_n(const std::string& content_name,
+                             const std::string& transport_name);
+  // For bundling.
+  void ChangeSctpTransport_n(const std::string& transport_name);
+  void DestroySctpTransport_n();
+  // SctpTransport signal handlers. Needed to marshal signals from the network
+  // to signaling thread.
+  void OnSctpTransportReadyToSendData_n();
+  // This may be called with "false" if the direction of the m= section causes
+  // us to tear down the SCTP connection.
+  void OnSctpTransportReadyToSendData_s(bool ready);
+  void OnSctpTransportDataReceived_n(const cricket::ReceiveDataParams& params,
+                                     const rtc::CopyOnWriteBuffer& payload);
+  // Beyond just firing the signal to the signaling thread, listens to SCTP
+  // CONTROL messages on unused SIDs and processes them as OPEN messages.
+  void OnSctpTransportDataReceived_s(const cricket::ReceiveDataParams& params,
+                                     const rtc::CopyOnWriteBuffer& payload);
+  void OnSctpStreamClosedRemotely_n(int sid);
 
   std::string BadStateErrMsg(State state);
   void SetIceConnectionState(PeerConnectionInterface::IceConnectionState state);
@@ -498,6 +527,7 @@ class WebRtcSession :
   // this session.
   bool SrtpRequired() const;
 
+  // TransportController signal handlers.
   void OnTransportControllerConnectionState(cricket::IceConnectionState state);
   void OnTransportControllerReceiving(bool receiving);
   void OnTransportControllerGatheringState(cricket::IceGatheringState state);
@@ -506,6 +536,7 @@ class WebRtcSession :
       const std::vector<cricket::Candidate>& candidates);
   void OnTransportControllerCandidatesRemoved(
       const std::vector<cricket::Candidate>& candidates);
+  void OnTransportControllerDtlsHandshakeError(rtc::SSLHandshakeError error);
 
   std::string GetSessionErrorMsg();
 
@@ -522,8 +553,6 @@ class WebRtcSession :
 
   const std::string GetTransportName(const std::string& content_name);
 
-  void OnDtlsHandshakeError(rtc::SSLHandshakeError error);
-
   rtc::Thread* const network_thread_;
   rtc::Thread* const worker_thread_;
   rtc::Thread* const signaling_thread_;
@@ -536,10 +565,39 @@ class WebRtcSession :
   bool initial_offerer_ = false;
 
   const std::unique_ptr<cricket::TransportController> transport_controller_;
+  const std::unique_ptr<cricket::SctpTransportInternalFactory> sctp_factory_;
   MediaControllerInterface* media_controller_;
   std::unique_ptr<cricket::VoiceChannel> voice_channel_;
   std::unique_ptr<cricket::VideoChannel> video_channel_;
-  std::unique_ptr<cricket::DataChannel> data_channel_;
+  // |rtp_data_channel_| is used if in RTP data channel mode, |sctp_transport_|
+  // when using SCTP.
+  std::unique_ptr<cricket::RtpDataChannel> rtp_data_channel_;
+
+  std::unique_ptr<cricket::SctpTransportInternal> sctp_transport_;
+  // |sctp_transport_name_| keeps track of what DTLS transport the SCTP
+  // transport is using (which can change due to bundling).
+  rtc::Optional<std::string> sctp_transport_name_;
+  // |sctp_content_name_| is the content name (MID) in SDP.
+  rtc::Optional<std::string> sctp_content_name_;
+  // Value cached on signaling thread. Only updated when SctpReadyToSendData
+  // fires on the signaling thread.
+  bool sctp_ready_to_send_data_ = false;
+  // Same as signals provided by SctpTransport, but these are guaranteed to
+  // fire on the signaling thread, whereas SctpTransport fires on the networking
+  // thread.
+  // |sctp_invoker_| is used so that any signals queued on the signaling thread
+  // from the network thread are immediately discarded if the SctpTransport is
+  // destroyed (due to m= section being rejected).
+  // TODO(deadbeef): Use a proxy object to ensure that method calls/signals
+  // are marshalled to the right thread. Could almost use proxy.h for this,
+  // but it doesn't have a mechanism for marshalling sigslot::signals
+  std::unique_ptr<rtc::AsyncInvoker> sctp_invoker_;
+  sigslot::signal1<bool> SignalSctpReadyToSendData;
+  sigslot::signal2<const cricket::ReceiveDataParams&,
+                   const rtc::CopyOnWriteBuffer&>
+      SignalSctpDataReceived;
+  sigslot::signal1<int> SignalSctpStreamClosedRemotely;
+
   cricket::ChannelManager* channel_manager_;
   IceObserver* ice_observer_;
   PeerConnectionInterface::IceConnectionState ice_connection_state_;