Open backdoor in VoiceEngineImpl to get at the actual voe::Channel objects from an ID.

webrtc/voice_engine/channel_proxy.cc

Index: webrtc/voice_engine/channel_proxy.cc
diff --git a/webrtc/voice_engine/channel_proxy.cc b/webrtc/voice_engine/channel_proxy.cc
new file mode 100644
index 0000000000000000000000000000000000000000..5a25f18855562bf0a3b68cc8d8586fab523731f6
--- /dev/null
+++ b/webrtc/voice_engine/channel_proxy.cc
@@ -0,0 +1,45 @@
+/*
+ *  Copyright (c) 2015 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.
+ */
+
+#include "webrtc/voice_engine/channel_proxy.h"
+
+#include "webrtc/base/checks.h"
+#include "webrtc/voice_engine/channel.h"
+
+namespace webrtc {
+namespace voe {
+ChannelProxy::ChannelProxy() : channel_owner_(nullptr) {
+}

[kwiberg-webrtc, 2015/11/25 10:44:59]

What's this constructor for?

[the sun, 2015/11/25 12:28:01]

For the mock.

+
+ChannelProxy::ChannelProxy(const ChannelOwner& channel_owner) :
+    channel_owner_(channel_owner) {
+  RTC_CHECK(channel_owner_.channel());
+}
+
+void ChannelProxy::SetRTCPStatus(bool enable) {
+  RTC_DCHECK(channel_owner_.channel());
+  channel_owner_.channel()->SetRTCPStatus(enable);
+}
+
+void ChannelProxy::SetLocalSSRC(uint32_t ssrc) {
+  RTC_DCHECK(channel_owner_.channel());
+  int error = channel_owner_.channel()->SetLocalSSRC(ssrc);
+  RTC_DCHECK_EQ(0, error);
+}
+
+void ChannelProxy::SetRTCP_CNAME(const std::string& c_name) {
+  // Note: VoERTP_RTCP::SetRTCP_CNAME() accepts a char[256] array.
+  std::string c_name_limited = c_name.substr(0, 255);

[kwiberg-webrtc, 2015/11/25 10:44:59]

Would it make sense to CHECK the size instead, or do we actually need to handle
this case?

[the sun, 2015/11/25 12:28:01]

AFAIU this string comes directly from the SDP, so yes, this is mitigating a
potential buffer overrun issue.

+  RTC_DCHECK(channel_owner_.channel());
+  int error = channel_owner_.channel()->SetRTCP_CNAME(c_name_limited.c_str());
+  RTC_DCHECK_EQ(0, error);
+}
+}  // namespace voe
+}  // namespace webrtc