Handle role conflict in the standalone RTCIceTransport

Bug: 926134
Change-Id: I202c76275a97d295866ea70079f95f814e6de5b6
Reviewed-on: https://chromium-review.googlesource.com/c/1443544
Commit-Queue: Steve Anton <steveanton@chromium.org>
Commit-Queue: Seth Hampson <shampson@chromium.org>
Auto-Submit: Steve Anton <steveanton@chromium.org>
Reviewed-by: Seth Hampson <shampson@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#627108}(cherry picked from commit f1fbab6)
Reviewed-on: https://chromium-review.googlesource.com/c/1446839
Reviewed-by: Steve Anton <steveanton@chromium.org>
Cr-Commit-Position: refs/branch-heads/3683@{#74}
Cr-Branched-From: e510299-refs/heads/master@{#625896}

Author: steveanton

third_party/blink/renderer/modules/peerconnection/adapters/ice_transport_adapter_impl.cc

@@ -37,6 +37,8 @@ IceTransportAdapterImpl::IceTransportAdapterImpl(
       this, &IceTransportAdapterImpl::OnStateChanged);
   p2p_transport_channel_->SignalNetworkRouteChanged.connect(
       this, &IceTransportAdapterImpl::OnNetworkRouteChanged);
+  p2p_transport_channel_->SignalRoleConflict.connect(
+      this, &IceTransportAdapterImpl::OnRoleConflict);
   // We need to set the ICE role even before Start is called since the Port
   // assumes that the role has been set before receiving incoming connectivity
   // checks. These checks can race with the information signaled for Start.
@@ -141,4 +143,37 @@ void IceTransportAdapterImpl::OnNetworkRouteChanged(
                      selected_connection->remote_candidate()));
 }
 
+static const char* IceRoleToString(cricket::IceRole role) {
+  switch (role) {
+    case cricket::ICEROLE_CONTROLLING:
+      return "controlling";
+    case cricket::ICEROLE_CONTROLLED:
+      return "controlled";
+    default:
+      return "unknown";
+  }
+}
+
+static cricket::IceRole IceRoleReversed(cricket::IceRole role) {
+  switch (role) {
+    case cricket::ICEROLE_CONTROLLING:
+      return cricket::ICEROLE_CONTROLLED;
+    case cricket::ICEROLE_CONTROLLED:
+      return cricket::ICEROLE_CONTROLLING;
+    default:
+      return cricket::ICEROLE_UNKNOWN;
+  }
+}
+
+void IceTransportAdapterImpl::OnRoleConflict(
+    cricket::IceTransportInternal* transport) {
+  DCHECK_EQ(transport, p2p_transport_channel_.get());
+  // This logic is copied from JsepTransportController.
+  cricket::IceRole reversed_role =
+      IceRoleReversed(p2p_transport_channel_->GetIceRole());
+  LOG(INFO) << "Got role conflict; switching to "
+            << IceRoleToString(reversed_role) << " role.";
+  p2p_transport_channel_->SetIceRole(reversed_role);
+}
+
 }  // namespace blink

third_party/blink/renderer/modules/peerconnection/adapters/ice_transport_adapter_impl.h

@@ -47,6 +47,7 @@ class IceTransportAdapterImpl final : public IceTransportAdapter,
   void OnStateChanged(cricket::IceTransportInternal* transport);
   void OnNetworkRouteChanged(
       absl::optional<rtc::NetworkRoute> new_network_route);
+  void OnRoleConflict(cricket::IceTransportInternal* transport);
 
   Delegate* const delegate_;
   std::unique_ptr<cricket::PortAllocator> port_allocator_;

third_party/blink/web_tests/external/wpt/webrtc/RTCIceTransport-extension.https.html

@@ -254,6 +254,26 @@
   ]);
 }, 'Two RTCIceTransports connect to each other');
 
+['controlling', 'controlled'].forEach(role => {
+  promise_test(async t => {
+    const [ localTransport, remoteTransport ] =
+        makeAndGatherTwoIceTransports(t);
+    localTransport.start(remoteTransport.getLocalParameters(), role);
+    localTransport.start(remoteTransport.getLocalParameters(), role);
+    const localWatcher = new EventWatcher(t, localTransport, 'statechange');
+    const remoteWatcher = new EventWatcher(t, remoteTransport, 'statechange');
+    await Promise.all([
+      localWatcher.wait_for('statechange').then(() => {
+        assert_equals(localTransport.state, 'connected');
+      }),
+      remoteWatcher.wait_for('statechange').then(() => {
+        assert_equals(remoteTransport.state, 'connected');
+      }),
+    ]);
+  }, `Two RTCIceTransports configured with the ${role} role resolve the ` +
+      'conflict in band and still connect.');
+});
+
 promise_test(async t => {
   async function waitForConnectedThenSelectedCandidatePairChange(t, transport,
       transportName) {