Publish TURN-only ICE candidates in some situations

1) Incoming call is from a number not in user's address book

2) Turn-only preference is enabled for all incoming/outgoing calls

// FREEBIE

res/values/strings.xml

@@ -1155,6 +1155,9 @@
     <string name="preferences_advanced__disable_signal_built_in_emoji_support">Disable Signal\'s built-in emoji support</string>
     <string name="preferences_advanced__video_calling_beta">Video calling beta</string>
     <string name="preferences_advanced__enable_support_for_next_generation_video_and_voice_calls">Support for next-generation video and voice calls when enabled by both parties. This feature is in beta.</string>
+    <string name="preferences_advanced__relay_all_calls_through_the_signal_server_to_avoid_revealing_your_ip_address">Relay all calls through the Signal server to avoid revealing your IP address to your contact. Enabling will reduce call quality.</string>
+    <string name="preferences_advanced__always_relay_calls">Always relay calls</string>
+
 
 
     <!-- **************************************** -->

res/xml/preferences_advanced.xml

@@ -25,6 +25,12 @@
             android:title="@string/preferences_advanced__video_calling_beta"
             android:summary="@string/preferences_advanced__enable_support_for_next_generation_video_and_voice_calls"/>
 
+    <org.thoughtcrime.securesms.components.SwitchPreferenceCompat
+            android:defaultValue="false"
+            android:key="pref_turn_only"
+            android:title="@string/preferences_advanced__always_relay_calls"
+            android:summary="@string/preferences_advanced__relay_all_calls_through_the_signal_server_to_avoid_revealing_your_ip_address"/>
+
     <Preference android:key="pref_choose_identity"
                 android:title="@string/preferences__choose_identity"
                 android:summary="@string/preferences__choose_your_contact_entry_from_the_contacts_list"/>

res/xml/preferences_app_protection.xml

@@ -33,7 +33,7 @@
             android:key="pref_blocking_identity_changes"
             android:title="@string/preferences_app_protection__safety_numbers_approval"
             android:summary="@string/preferences_app_protecting__require_approval_of_new_safety_numbers_when_they_change"/>
-
+    
     <Preference android:key="preference_category_blocked"
                 android:title="@string/preferences_app_protection__blocked_contacts" />
 </PreferenceScreen>

src/org/thoughtcrime/securesms/contacts/ContactAccessor.java

@@ -61,6 +61,23 @@ public class ContactAccessor {
     return instance;
   }
 
+  public boolean isSystemContact(Context context, String number) {
+    Uri      uri        = Uri.withAppendedPath(PhoneLookup.CONTENT_FILTER_URI, Uri.encode(number));
+    String[] projection = new String[]{PhoneLookup.DISPLAY_NAME, PhoneLookup.LOOKUP_KEY,
+                                       PhoneLookup._ID, PhoneLookup.NUMBER};
+    Cursor   cursor     = context.getContentResolver().query(uri, projection, null, null, null);
+
+    try {
+      if (cursor != null && cursor.moveToFirst()) {
+        return true;
+      }
+    } finally {
+      if (cursor != null) cursor.close();
+    }
+
+    return false;
+  }
+
   public Collection<ContactData> getContactsWithPush(Context context) {
     final ContentResolver resolver = context.getContentResolver();
     final String[] inProjection    = new String[]{PhoneLookup._ID, PhoneLookup.DISPLAY_NAME};

src/org/thoughtcrime/securesms/service/WebRtcCallService.java

@@ -29,6 +29,7 @@ import org.thoughtcrime.redphone.util.AudioUtils;
 import org.thoughtcrime.redphone.util.UncaughtExceptionHandlerManager;
 import org.thoughtcrime.securesms.ApplicationContext;
 import org.thoughtcrime.securesms.WebRtcCallActivity;
+import org.thoughtcrime.securesms.contacts.ContactAccessor;
 import org.thoughtcrime.securesms.database.DatabaseFactory;
 import org.thoughtcrime.securesms.dependencies.InjectableType;
 import org.thoughtcrime.securesms.dependencies.SignalCommunicationModule.SignalMessageSenderFactory;
@@ -40,6 +41,7 @@ import org.thoughtcrime.securesms.recipients.Recipients;
 import org.thoughtcrime.securesms.util.FutureTaskListener;
 import org.thoughtcrime.securesms.util.ListenableFutureTask;
 import org.thoughtcrime.securesms.util.ServiceUtil;
+import org.thoughtcrime.securesms.util.TextSecurePreferences;
 import org.thoughtcrime.securesms.util.Util;
 import org.thoughtcrime.securesms.webrtc.CallNotificationManager;
 import org.thoughtcrime.securesms.webrtc.PeerConnectionFactoryOptions;
@@ -279,7 +281,10 @@ public class WebRtcCallService extends Service implements InjectableType, PeerCo
       @Override
       public void onSuccessContinue(List<PeerConnection.IceServer> result) {
         try {
-          WebRtcCallService.this.peerConnection = new PeerConnectionWrapper(WebRtcCallService.this, peerConnectionFactory, WebRtcCallService.this, localRenderer, result);
+          boolean isSystemContact = ContactAccessor.getInstance().isSystemContact(WebRtcCallService.this, recipient.getNumber());
+          boolean isAlwaysTurn    = TextSecurePreferences.isTurnOnly(WebRtcCallService.this);
+
+          WebRtcCallService.this.peerConnection = new PeerConnectionWrapper(WebRtcCallService.this, peerConnectionFactory, WebRtcCallService.this, localRenderer, result, !isSystemContact || isAlwaysTurn);
           WebRtcCallService.this.peerConnection.setRemoteDescription(new SessionDescription(SessionDescription.Type.OFFER, offer));
           WebRtcCallService.this.lockManager.updatePhoneState(LockManager.PhoneState.PROCESSING);
 
@@ -330,7 +335,9 @@ public class WebRtcCallService extends Service implements InjectableType, PeerCo
         @Override
         public void onSuccessContinue(List<PeerConnection.IceServer> result) {
           try {
-            WebRtcCallService.this.peerConnection = new PeerConnectionWrapper(WebRtcCallService.this, peerConnectionFactory, WebRtcCallService.this, localRenderer, result);
+            boolean isAlwaysTurn = TextSecurePreferences.isTurnOnly(WebRtcCallService.this);
+
+            WebRtcCallService.this.peerConnection = new PeerConnectionWrapper(WebRtcCallService.this, peerConnectionFactory, WebRtcCallService.this, localRenderer, result, isAlwaysTurn);
             WebRtcCallService.this.dataChannel    = WebRtcCallService.this.peerConnection.createDataChannel(DATA_CHANNEL_NAME);
             WebRtcCallService.this.dataChannel.registerObserver(WebRtcCallService.this);
 

src/org/thoughtcrime/securesms/util/TextSecurePreferences.java

@@ -99,6 +99,11 @@ public class TextSecurePreferences {
   public  static final String SYSTEM_EMOJI_PREF                = "pref_system_emoji";
   private static final String MULTI_DEVICE_PROVISIONED_PREF    = "pref_multi_device";
   public  static final String DIRECT_CAPTURE_CAMERA_ID         = "pref_direct_capture_camera_id";
+  private static final String ALWAYS_RELAY_CALLS_PREF          = "pref_turn_only";
+
+  public static boolean isTurnOnly(Context context) {
+    return getBooleanPreference(context, ALWAYS_RELAY_CALLS_PREF, false);
+  }
 
   public static boolean isWebrtcCallingEnabled(Context context) {
     return getBooleanPreference(context, WEBRTC_CALLING_PREF, false);

src/org/thoughtcrime/securesms/webrtc/PeerConnectionWrapper.java

@@ -47,7 +47,8 @@ public class PeerConnectionWrapper {
                                @NonNull PeerConnectionFactory factory,
                                @NonNull PeerConnection.Observer observer,
                                @NonNull VideoRenderer.Callbacks localRenderer,
-                               @NonNull List<PeerConnection.IceServer> turnServers)
+                               @NonNull List<PeerConnection.IceServer> turnServers,
+                               boolean hideIp)
   {
     List<PeerConnection.IceServer> iceServers = new LinkedList<>();
     iceServers.add(STUN_SERVER);
@@ -60,6 +61,10 @@ public class PeerConnectionWrapper {
     configuration.bundlePolicy  = PeerConnection.BundlePolicy.MAXBUNDLE;
     configuration.rtcpMuxPolicy = PeerConnection.RtcpMuxPolicy.REQUIRE;
 
+    if (hideIp) {
+      configuration.iceTransportsType = PeerConnection.IceTransportsType.RELAY;
+    }
+
     constraints.optional.add(new MediaConstraints.KeyValuePair("DtlsSrtpKeyAgreement", "true"));
     audioConstraints.optional.add(new MediaConstraints.KeyValuePair("DtlsSrtpKeyAgreement", "true"));