Remove the dependency of TransportChannel and TransportChannelImpl.

webrtc/p2p/base/dtlstransportchannel.h

 /*
  *  Copyright 2011 The WebRTC Project Authors. All rights reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
 #ifndef WEBRTC_P2P_BASE_DTLSTRANSPORTCHANNEL_H_
 #define WEBRTC_P2P_BASE_DTLSTRANSPORTCHANNEL_H_
 
 #include <memory>
 #include <string>
 #include <vector>
 
-#include "webrtc/p2p/base/transportchannelimpl.h"
 #include "webrtc/base/buffer.h"
 #include "webrtc/base/bufferqueue.h"
 #include "webrtc/base/constructormagic.h"
 #include "webrtc/base/sslstreamadapter.h"
 #include "webrtc/base/stream.h"
+#include "webrtc/p2p/base/dtlstransportinternal.h"
 
 namespace rtc {
 class PacketTransportInterface;
 }
 
 namespace cricket {
 
 // A bridge between a packet-oriented/channel-type interface on
 // the bottom and a StreamInterface on the top.
 class StreamInterfaceChannel : public rtc::StreamInterface {
@@ skipping 25 matching lines @@
 
 
 // This class provides a DTLS SSLStreamAdapter inside a TransportChannel-style
 // packet-based interface, wrapping an existing TransportChannel instance
 // (e.g a P2PTransportChannel)
 // Here's the way this works:
 //
 //   DtlsTransportChannelWrapper {
 //       SSLStreamAdapter* dtls_ {
 //           StreamInterfaceChannel downward_ {
-//               TransportChannelImpl* channel_;
+//               IceTransportInternal* channel_;
 //           }
 //       }
 //   }
 //
 //   - Data which comes into DtlsTransportChannelWrapper from the underlying
 //     channel_ via OnReadPacket() is checked for whether it is DTLS
 //     or not, and if it is, is passed to DtlsTransportChannelWrapper::
 //     HandleDtlsPacket, which pushes it into to downward_.
 //     dtls_ is listening for events on downward_, so it immediately calls
 //     downward_->Read().
 //
 //   - Data written to DtlsTransportChannelWrapper is passed either to
 //      downward_ or directly to channel_, depending on whether DTLS is
 //     negotiated and whether the flags include PF_SRTP_BYPASS
 //
 //   - The SSLStreamAdapter writes to downward_->Write()
 //     which translates it into packet writes on channel_.
-class DtlsTransportChannelWrapper : public TransportChannelImpl {
+class DtlsTransportChannelWrapper : public DtlsTransportInternal {
  public:
   // The parameters here are:
   // channel -- the TransportChannel we are wrapping
   explicit DtlsTransportChannelWrapper(TransportChannelImpl* channel);
   ~DtlsTransportChannelWrapper() override;
 
-  void SetIceRole(IceRole role) override { channel_->SetIceRole(role); }
-  IceRole GetIceRole() const override { return channel_->GetIceRole(); }
+  DtlsTransportState dtls_state() const override { return dtls_state_; }
+
+  const std::string& transport_name() const override { return transport_name_; }
+
+  int component() const override { return component_; }
+
+  // Returns false if no local certificate was set, or if the peer doesn't
+  // support DTLS.
+  bool IsDtlsActive() const override { return dtls_active_; }
+
   bool SetLocalCertificate(
       const rtc::scoped_refptr<rtc::RTCCertificate>& certificate) override;
   rtc::scoped_refptr<rtc::RTCCertificate> GetLocalCertificate() const override;
 
   bool SetRemoteFingerprint(const std::string& digest_alg,
                             const uint8_t* digest,
                             size_t digest_len) override;
 
-  // Returns false if no local certificate was set, or if the peer doesn't
-  // support DTLS.
-  bool IsDtlsActive() const override { return dtls_active_; }
 
   // Called to send a packet (via DTLS, if turned on).
   int SendPacket(const char* data,
                  size_t size,
                  const rtc::PacketOptions& options,
                  int flags) override;
 
-  // TransportChannel calls that we forward to the wrapped transport.
-  int SetOption(rtc::Socket::Option opt, int value) override {
-    return channel_->SetOption(opt, value);
-  }
   bool GetOption(rtc::Socket::Option opt, int* value) override {
     return channel_->GetOption(opt, value);
   }
-  int GetError() override { return channel_->GetError(); }
-  bool GetStats(ConnectionInfos* infos) override {
-    return channel_->GetStats(infos);
-  }
 
   virtual bool SetSslMaxProtocolVersion(rtc::SSLProtocolVersion version);
 
   // Set up the ciphers to use for DTLS-SRTP. If this method is not called
   // before DTLS starts, or |ciphers| is empty, SRTP keys won't be negotiated.
   // This method should be called before SetupDtls.
   bool SetSrtpCryptoSuites(const std::vector<int>& ciphers) override;
 
   // Find out which DTLS-SRTP cipher was negotiated
   bool GetSrtpCryptoSuite(int* cipher) override;
@@ skipping 18 matching lines @@
                             bool use_context,
                             uint8_t* result,
                             size_t result_len) override {
     return (dtls_.get()) ? dtls_->ExportKeyingMaterial(label, context,
                                                        context_len,
                                                        use_context,
                                                        result, result_len)
         : false;
   }
 
-  // TransportChannelImpl calls.
-  TransportChannelState GetState() const override {
-    return channel_->GetState();
-  }
-  void SetIceTiebreaker(uint64_t tiebreaker) override {
-    channel_->SetIceTiebreaker(tiebreaker);
-  }
-  void SetIceParameters(const IceParameters& ice_params) override {
-    channel_->SetIceParameters(ice_params);
-  }
-  void SetRemoteIceParameters(const IceParameters& ice_params) override {
-    channel_->SetRemoteIceParameters(ice_params);
-  }
-  void SetRemoteIceMode(IceMode mode) override {
-    channel_->SetRemoteIceMode(mode);
-  }
-
-  void MaybeStartGathering() override { channel_->MaybeStartGathering(); }
-
-  IceGatheringState gathering_state() const override {
-    return channel_->gathering_state();
-  }
-
-  void AddRemoteCandidate(const Candidate& candidate) override {
-    channel_->AddRemoteCandidate(candidate);
-  }
-  void RemoveRemoteCandidate(const Candidate& candidate) override {
-    channel_->RemoveRemoteCandidate(candidate);
-  }
-
-  void SetMetricsObserver(webrtc::MetricsObserverInterface* observer) override {
-    channel_->SetMetricsObserver(observer);
-  }
-
-  void SetIceConfig(const IceConfig& config) override {
-    channel_->SetIceConfig(config);
-  }
-
-  // Needed by DtlsTransport.
-  TransportChannelImpl* channel() { return channel_; }
+  TransportChannelImpl* ice_transport() override { return channel_; }

[Taylor Brandstetter, 2017/01/03 23:21:59]

Can this be IceTransportInternal instead now (assuming this CL is landed after
the one that introduces IceTransportInternal)?

[Zhi Huang, 2017/01/10 18:30:51]

Yes, I'll merge the IceTransportInternal change into this CL.

 
   // For informational purposes. Tells if the DTLS handshake has finished.
   // This may be true even if writable() is false, if the remote fingerprint
   // has not yet been verified.
   bool IsDtlsConnected();
 
+  bool receiving() const override { return receiving_; }
+
+  bool writable() const override { return writable_; }
+
+  int GetError() override { return channel_->GetError(); }

[Taylor Brandstetter, 2017/01/03 23:21:59]

Since this and SetOption just pass through to the ICE channel, can they be
removed? If not, can you leave a TODO and describe what would need to be done?

[Zhi Huang, 2017/01/10 18:30:51]

These functions are from the PacketTransportInterface. But we can hide them by
implementing them in the DtlsTransportInternal.

+
+  int SetOption(rtc::Socket::Option opt, int value) override {
+    return channel_->SetOption(opt, value);
+  }
+
+  bool SetSrtpCiphers(const std::vector<std::string>& ciphers) override {
+    std::vector<int> crypto_suites;
+    for (const auto cipher : ciphers) {
+      crypto_suites.push_back(rtc::SrtpCryptoSuiteFromName(cipher));
+    }
+    return SetSrtpCryptoSuites(crypto_suites);
+  }
+
+  std::string ToString() const {
+    const char RECEIVING_ABBREV[2] = {'_', 'R'};
+    const char WRITABLE_ABBREV[2] = {'_', 'W'};
+    std::stringstream ss;
+    ss << "DtlsTransport[" << transport_name_ << "|" << component_ << "|"
+       << RECEIVING_ABBREV[receiving()] << WRITABLE_ABBREV[writable()] << "]";
+    return ss.str();
+  }
+
  private:
   void OnWritableState(rtc::PacketTransportInterface* transport);
   void OnReadPacket(rtc::PacketTransportInterface* transport,
                     const char* data,
                     size_t size,
                     const rtc::PacketTime& packet_time,
                     int flags);
   void OnSentPacket(rtc::PacketTransportInterface* transport,
                     const rtc::SentPacket& sent_packet);
   void OnReadyToSend(rtc::PacketTransportInterface* transport);
   void OnReceivingState(rtc::PacketTransportInterface* transport);
   void OnDtlsEvent(rtc::StreamInterface* stream_, int sig, int err);
   bool SetupDtls();
   void MaybeStartDtls();
   bool HandleDtlsPacket(const char* data, size_t size);
-  void OnGatheringState(TransportChannelImpl* channel);
-  void OnCandidateGathered(TransportChannelImpl* channel, const Candidate& c);
-  void OnCandidatesRemoved(TransportChannelImpl* channel,
-                           const Candidates& candidates);
-  void OnRoleConflict(TransportChannelImpl* channel);
-  void OnRouteChange(TransportChannel* channel, const Candidate& candidate);
-  void OnSelectedCandidatePairChanged(
-      TransportChannel* channel,
-      CandidatePairInterface* selected_candidate_pair,
-      int last_sent_packet_id,
-      bool ready_to_send);
-  void OnChannelStateChanged(TransportChannelImpl* channel);
   void OnDtlsHandshakeError(rtc::SSLHandshakeError error);
+  void set_receiving(bool receiving);
+  void set_writable(bool writable);
+  // Sets the DTLS state, signaling if necessary.
+  void set_dtls_state(DtlsTransportState state);
 
+  std::string transport_name_;
+  int component_;
+  DtlsTransportState dtls_state_ = DTLS_TRANSPORT_NEW;
   rtc::Thread* network_thread_;  // Everything should occur on this thread.
   // Underlying channel, not owned by this class.
   TransportChannelImpl* const channel_;
   std::unique_ptr<rtc::SSLStreamAdapter> dtls_;  // The DTLS stream
   StreamInterfaceChannel* downward_;  // Wrapper for channel_, owned by dtls_.
   std::vector<int> srtp_ciphers_;     // SRTP ciphers to use with DTLS.
   bool dtls_active_ = false;
   rtc::scoped_refptr<rtc::RTCCertificate> local_certificate_;
   rtc::SSLRole ssl_role_;
   rtc::SSLProtocolVersion ssl_max_version_;
   rtc::Buffer remote_fingerprint_value_;
   std::string remote_fingerprint_algorithm_;
 
   // Cached DTLS ClientHello packet that was received before we started the
   // DTLS handshake. This could happen if the hello was received before the
   // transport channel became writable, or before a remote fingerprint was
   // received.
   rtc::Buffer cached_client_hello_;
 
+  bool receiving_ = false;
+  bool writable_ = false;
+
   RTC_DISALLOW_COPY_AND_ASSIGN(DtlsTransportChannelWrapper);
 };
 
 }  // namespace cricket
 
 #endif  // WEBRTC_P2P_BASE_DTLSTRANSPORTCHANNEL_H_