Support encrypted RTP extensions (RFC 6904)

webrtc/pc/channel.h

Index: webrtc/pc/channel.h
diff --git a/webrtc/pc/channel.h b/webrtc/pc/channel.h
index 6ff0556c9798525ffbe3d29b739dc55085c8681c..2fb10edfa49c17f5e82b73605a68aa11f2b5ccc3 100644
--- a/webrtc/pc/channel.h
+++ b/webrtc/pc/channel.h
@@ -303,7 +303,8 @@ class BaseChannel
   // Do the DTLS key expansion and impose it on the SRTP/SRTCP filters.
   // |rtcp_channel| indicates whether to set up the RTP or RTCP filter.
   bool SetupDtlsSrtp_n(bool rtcp);
-  void MaybeSetupDtlsSrtp_n();
+  // Returns true if DTLS-SRTP has been setup.
+  bool MaybeSetupDtlsSrtp_n();
   // Set the DTLS-SRTP cipher policy on this channel as appropriate.
   bool SetDtlsSrtpCryptoSuites_n(DtlsTransportInternal* transport, bool rtcp);
 
@@ -341,6 +342,8 @@ class BaseChannel
   // present in remote supported extensions list.
   void MaybeCacheRtpAbsSendTimeHeaderExtension_w(
       const std::vector<webrtc::RtpExtension>& extensions);
+  void PrepareHeaderExtensions_w(ContentSource source,
+      const std::vector<webrtc::RtpExtension>& extensions);

[pthatcher1, 2017/03/21 07:07:06]

void PrepareRtpHeaderExtensions_w would be a better name.

Also, prepare them for what?  This could use a comment.

[joachim, 2017/03/23 00:04:33]

Method has been removed.

 
   bool CheckSrtpConfig_n(const std::vector<CryptoParams>& cryptos,
                          bool* dtls,
@@ -385,6 +388,8 @@ class BaseChannel
   void SignalSentPacket_w(const rtc::SentPacket& sent_packet);
   bool IsReadyToSendMedia_n() const;
   void CacheRtpAbsSendTimeHeaderExtension_n(int rtp_abs_sendtime_extn_id);
+  void PrepareHeaderExtensions_n(ContentSource source,
+      const std::vector<webrtc::RtpExtension> encrypted_headers);
   int GetTransportOverheadPerPacket() const;
   void UpdateTransportOverhead();
 
@@ -423,6 +428,15 @@ class BaseChannel
   const bool srtp_required_ = true;
   rtc::CryptoOptions crypto_options_;
   int rtp_abs_sendtime_extn_id_ = -1;
+  std::vector<webrtc::RtpExtension> rtp_local_encrypted_headers_;
+  std::vector<webrtc::RtpExtension> rtp_remote_encrypted_headers_;
+
+  static const int kNoEncryptedHeadersReady = 0;
+  static const int kLocalEncryptedHeadersReady = 1;
+  static const int kRemoteEncryptedHeadersReady = 2;
+  static const int kAllEncryptedHeadersReady =
+      kLocalEncryptedHeadersReady | kRemoteEncryptedHeadersReady;
+  int rtp_encrypted_headers_ready_ = kNoEncryptedHeadersReady;

[Taylor Brandstetter, 2017/03/22 18:00:11]

Can this extra state be derived from existing information? In which case it
could just be replaced by a helper method?

[joachim, 2017/03/23 00:04:33]

I completely removed the extra state.

 
   // MediaChannel related members that should be accessed from the worker
   // thread.