Add BT - DataTracker connection

Allows the external BT stack the means to communicate with
ConnectivityService during reverse tethering.

bug:8445208
Change-Id: Ice7dfb0b50c9481d359aed14a51372878185171c

core/java/android/net/ConnectivityManager.java

@@ -23,6 +23,7 @@ import android.annotation.SdkConstant.SdkConstantType;
 import android.content.Context;
 import android.os.Binder;
 import android.os.Build.VERSION_CODES;
+import android.os.Messenger;
 import android.os.RemoteException;
 import android.provider.Settings;
 
@@ -1280,4 +1281,17 @@ public class ConnectivityManager {
         }
     }
 
+    /**
+     * Supply the backend messenger for a network tracker
+     *
+     * @param type NetworkType to set
+     * @param messenger {@link Messenger}
+     * {@hide}
+     */
+    public void supplyMessenger(int networkType, Messenger messenger) {
+        try {
+            mService.supplyMessenger(networkType, messenger);
+        } catch (RemoteException e) {
+        }
+    }
 }

core/java/android/net/IConnectivityManager.aidl

@@ -22,6 +22,7 @@ import android.net.NetworkQuotaInfo;
 import android.net.NetworkState;
 import android.net.ProxyProperties;
 import android.os.IBinder;
+import android.os.Messenger;
 import android.os.ParcelFileDescriptor;
 
 import com.android.internal.net.LegacyVpnInfo;
@@ -126,4 +127,6 @@ interface IConnectivityManager
     boolean updateLockdownVpn();
 
     void captivePortalCheckComplete(in NetworkInfo info);
+
+    void supplyMessenger(int networkType, in Messenger messenger);
 }

services/java/com/android/server/ConnectivityService.java

@@ -74,6 +74,7 @@ import android.os.IBinder;
 import android.os.INetworkManagementService;
 import android.os.Looper;
 import android.os.Message;
+import android.os.Messenger;
 import android.os.ParcelFileDescriptor;
 import android.os.PowerManager;
 import android.os.Process;
@@ -3220,7 +3221,7 @@ public class ConnectivityService extends IConnectivityManager.Stub {
         throwIfLockdownEnabled();
         try {
             int type = mActiveDefaultNetwork;
-            if (ConnectivityManager.isNetworkTypeValid(type)) {
+            if (ConnectivityManager.isNetworkTypeValid(type) && mNetTrackers[type] != null) {
                 mVpn.protect(socket, mNetTrackers[type].getLinkProperties().getInterfaceName());
                 return true;
             }
@@ -3425,4 +3426,12 @@ public class ConnectivityService extends IConnectivityManager.Stub {
             throw new IllegalStateException("Unavailable in lockdown mode");
         }
     }
+
+    public void supplyMessenger(int networkType, Messenger messenger) {
+        enforceConnectivityInternalPermission();
+
+        if (isNetworkTypeValid(networkType) && mNetTrackers[networkType] != null) {
+            mNetTrackers[networkType].supplyMessenger(messenger);
+        }
+    }
 }