Allow opening tethering when data saver ON

When data saver enabled, tethering would be OFF.
Currently settings would not allow user to turning tethering back.
After aosp/1181583 is merged, user can turn tethering back without
turning data saver OFF.

Bug: 145711175
Bug: 142374233
Test: atest TetheringTests
      OFF/ON tethering when data saver ON

Change-Id: I59e662ba771a563f5f1766ba29e05246b8280220

6 files changed, 93 insertions, 41 deletions

diff --git a/core/java/android/net/INetworkPolicyManager.aidl b/core/java/android/net/INetworkPolicyManager.aidl
index 385cb1d68b57..72a6b397a30c 100644
--- a/core/java/android/net/INetworkPolicyManager.aidl
+++ b/core/java/android/net/INetworkPolicyManager.aidl
@@ -57,9 +57,6 @@ interface INetworkPolicyManager {
     @UnsupportedAppUsage
     boolean getRestrictBackground();
 
-    /** Callback used to change internal state on tethering */
-    void onTetheringChanged(String iface, boolean tethering);
-
     /** Gets the restrict background status based on the caller's UID:
         1 - disabled
         2 - whitelisted
diff --git a/packages/Tethering/src/com/android/server/connectivity/tethering/Tethering.java b/packages/Tethering/src/com/android/server/connectivity/tethering/Tethering.java
index 301f805d3d03..d372d1aa88df 100644
--- a/packages/Tethering/src/com/android/server/connectivity/tethering/Tethering.java
+++ b/packages/Tethering/src/com/android/server/connectivity/tethering/Tethering.java
@@ -20,6 +20,7 @@ import static android.content.pm.PackageManager.PERMISSION_GRANTED;
 import static android.hardware.usb.UsbManager.USB_CONFIGURED;
 import static android.hardware.usb.UsbManager.USB_CONNECTED;
 import static android.hardware.usb.UsbManager.USB_FUNCTION_RNDIS;
+import static android.net.ConnectivityManager.ACTION_RESTRICT_BACKGROUND_CHANGED;
 import static android.net.ConnectivityManager.CONNECTIVITY_ACTION;
 import static android.net.ConnectivityManager.EXTRA_NETWORK_INFO;
 import static android.net.TetheringManager.ACTION_TETHER_STATE_CHANGED;
@@ -64,8 +65,8 @@ import android.content.Intent;
 import android.content.IntentFilter;
 import android.content.res.Resources;
 import android.hardware.usb.UsbManager;
+import android.net.ConnectivityManager;
 import android.net.INetd;
-import android.net.INetworkPolicyManager;
 import android.net.ITetheringEventCallback;
 import android.net.IpPrefix;
 import android.net.LinkAddress;
@@ -176,7 +177,6 @@ public class Tethering {
     private final Context mContext;
     private final ArrayMap<String, TetherState> mTetherStates;
     private final BroadcastReceiver mStateReceiver;
-    private final INetworkPolicyManager mPolicyManager;
     private final Looper mLooper;
     private final StateMachine mTetherMasterSM;
     private final OffloadController mOffloadController;
@@ -206,12 +206,12 @@ public class Tethering {
     private boolean mWifiTetherRequested;
     private Network mTetherUpstream;
     private TetherStatesParcel mTetherStatesParcel;
+    private boolean mDataSaverEnabled = false;
 
     public Tethering(TetheringDependencies deps) {
         mLog.mark("Tethering.constructed");
         mDeps = deps;
         mContext = mDeps.getContext();
-        mPolicyManager = mDeps.getINetworkPolicyManager();
         mNetd = mDeps.getINetd(mContext);
         mLooper = mDeps.getTetheringLooper();
 
@@ -288,6 +288,7 @@ public class Tethering {
         filter.addAction(Intent.ACTION_CONFIGURATION_CHANGED);
         filter.addAction(WifiP2pManager.WIFI_P2P_CONNECTION_CHANGED_ACTION);
         filter.addAction(UserManager.ACTION_USER_RESTRICTIONS_CHANGED);
+        filter.addAction(ACTION_RESTRICT_BACKGROUND_CHANGED);
         mContext.registerReceiver(mStateReceiver, filter, null, handler);
     }
 
@@ -484,7 +485,7 @@ public class Tethering {
     }
 
     private void setBluetoothTethering(final boolean enable, final ResultReceiver receiver) {
-        final BluetoothAdapter adapter = BluetoothAdapter.getDefaultAdapter();
+        final BluetoothAdapter adapter = mDeps.getBluetoothAdapter();
         if (adapter == null || !adapter.isEnabled()) {
             Log.w(TAG, "Tried to enable bluetooth tethering with null or disabled adapter. null: "
                     + (adapter == null));
@@ -775,6 +776,9 @@ public class Tethering {
             } else if (action.equals(UserManager.ACTION_USER_RESTRICTIONS_CHANGED)) {
                 mLog.log("OBSERVED user restrictions changed");
                 handleUserRestrictionAction();
+            } else if (action.equals(ACTION_RESTRICT_BACKGROUND_CHANGED)) {
+                mLog.log("OBSERVED data saver changed");
+                handleDataSaverChanged();
             }
         }
 
@@ -885,6 +889,20 @@ public class Tethering {
         private void handleUserRestrictionAction() {
             mTetheringRestriction.onUserRestrictionsChanged();
         }
+
+        private void handleDataSaverChanged() {
+            final ConnectivityManager connMgr = (ConnectivityManager) mContext.getSystemService(
+                    Context.CONNECTIVITY_SERVICE);
+            final boolean isDataSaverEnabled = connMgr.getRestrictBackgroundStatus()
+                    != ConnectivityManager.RESTRICT_BACKGROUND_STATUS_DISABLED;
+
+            if (mDataSaverEnabled == isDataSaverEnabled) return;
+
+            mDataSaverEnabled = isDataSaverEnabled;
+            if (mDataSaverEnabled) {
+                untetherAll();
+            }
+        }
     }
 
     @VisibleForTesting
@@ -1982,15 +2000,6 @@ public class Tethering {
 
         mLog.log(String.format("OBSERVED iface=%s state=%s error=%s", iface, state, error));
 
-        try {
-            // Notify that we're tethering (or not) this interface.
-            // This is how data saver for instance knows if the user explicitly
-            // turned on tethering (thus keeping us from being in data saver mode).
-            mPolicyManager.onTetheringChanged(iface, state == IpServer.STATE_TETHERED);
-        } catch (RemoteException e) {
-            // Not really very much we can do here.
-        }
-
         // If TetherMasterSM is in ErrorState, TetherMasterSM stays there.
         // Thus we give a chance for TetherMasterSM to recover to InitialState
         // by sending CMD_CLEAR_ERROR
diff --git a/packages/Tethering/src/com/android/server/connectivity/tethering/TetheringDependencies.java b/packages/Tethering/src/com/android/server/connectivity/tethering/TetheringDependencies.java
index 79e99e8023ed..247ed4799327 100644
--- a/packages/Tethering/src/com/android/server/connectivity/tethering/TetheringDependencies.java
+++ b/packages/Tethering/src/com/android/server/connectivity/tethering/TetheringDependencies.java
@@ -16,9 +16,9 @@
 
 package com.android.server.connectivity.tethering;
 
+import android.bluetooth.BluetoothAdapter;
 import android.content.Context;
 import android.net.INetd;
-import android.net.INetworkPolicyManager;
 import android.net.NetworkRequest;
 import android.net.ip.IpServer;
 import android.net.util.SharedLog;
@@ -106,14 +106,6 @@ public abstract class TetheringDependencies {
     }
 
     /**
-     * Get a reference to INetworkPolicyManager to be used by tethering.
-     */
-    public INetworkPolicyManager getINetworkPolicyManager() {
-        return INetworkPolicyManager.Stub.asInterface(
-                ServiceManager.getService(Context.NETWORK_POLICY_SERVICE));
-    }
-
-    /**
      * Get a reference to INetd to be used by tethering.
      */
     public INetd getINetd(Context context) {
@@ -130,4 +122,9 @@ public abstract class TetheringDependencies {
      *  Get Context of TetheringSerice.
      */
     public abstract Context getContext();
+
+    /**
+     * Get a reference to BluetoothAdapter to be used by tethering.
+     */
+    public abstract BluetoothAdapter getBluetoothAdapter();
 }
diff --git a/packages/Tethering/src/com/android/server/connectivity/tethering/TetheringService.java b/packages/Tethering/src/com/android/server/connectivity/tethering/TetheringService.java
index 99130d20e614..cb7d3920e693 100644
--- a/packages/Tethering/src/com/android/server/connectivity/tethering/TetheringService.java
+++ b/packages/Tethering/src/com/android/server/connectivity/tethering/TetheringService.java
@@ -24,6 +24,7 @@ import static android.net.TetheringManager.TETHER_ERROR_UNSUPPORTED;
 import static android.net.dhcp.IDhcpServer.STATUS_UNKNOWN_ERROR;
 
 import android.app.Service;
+import android.bluetooth.BluetoothAdapter;
 import android.content.Context;
 import android.content.Intent;
 import android.net.IIntResultListener;
@@ -376,6 +377,11 @@ public class TetheringService extends Service {
                     }
                     return INetworkStackConnector.Stub.asInterface(connector);
                 }
+
+                @Override
+                public BluetoothAdapter getBluetoothAdapter() {
+                    return BluetoothAdapter.getDefaultAdapter();
+                }
             };
         }
         return mDeps;
diff --git a/packages/Tethering/tests/unit/src/com/android/server/connectivity/tethering/TetheringTest.java b/packages/Tethering/tests/unit/src/com/android/server/connectivity/tethering/TetheringTest.java
index eaac159a87d8..467187697823 100644
--- a/packages/Tethering/tests/unit/src/com/android/server/connectivity/tethering/TetheringTest.java
+++ b/packages/Tethering/tests/unit/src/com/android/server/connectivity/tethering/TetheringTest.java
@@ -19,6 +19,9 @@ package com.android.server.connectivity.tethering;
 import static android.hardware.usb.UsbManager.USB_CONFIGURED;
 import static android.hardware.usb.UsbManager.USB_CONNECTED;
 import static android.hardware.usb.UsbManager.USB_FUNCTION_RNDIS;
+import static android.net.ConnectivityManager.ACTION_RESTRICT_BACKGROUND_CHANGED;
+import static android.net.ConnectivityManager.RESTRICT_BACKGROUND_STATUS_DISABLED;
+import static android.net.ConnectivityManager.RESTRICT_BACKGROUND_STATUS_ENABLED;
 import static android.net.RouteInfo.RTN_UNICAST;
 import static android.net.TetheringManager.ACTION_TETHER_STATE_CHANGED;
 import static android.net.TetheringManager.EXTRA_ACTIVE_LOCAL_ONLY;
@@ -53,6 +56,7 @@ import static org.mockito.Mockito.any;
 import static org.mockito.Mockito.doThrow;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.reset;
 import static org.mockito.Mockito.spy;
 import static org.mockito.Mockito.timeout;
 import static org.mockito.Mockito.times;
@@ -61,6 +65,7 @@ import static org.mockito.Mockito.verifyNoMoreInteractions;
 import static org.mockito.Mockito.when;
 
 import android.app.usage.NetworkStatsManager;
+import android.bluetooth.BluetoothAdapter;
 import android.content.BroadcastReceiver;
 import android.content.ContentResolver;
 import android.content.Context;
@@ -69,6 +74,7 @@ import android.content.IntentFilter;
 import android.content.pm.ApplicationInfo;
 import android.content.res.Resources;
 import android.hardware.usb.UsbManager;
+import android.net.ConnectivityManager;
 import android.net.INetd;
 import android.net.INetworkPolicyManager;
 import android.net.ITetheringEventCallback;
@@ -133,6 +139,7 @@ import java.net.Inet4Address;
 import java.net.Inet6Address;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collection;
 import java.util.Vector;
 
 @RunWith(AndroidJUnit4.class)
@@ -167,6 +174,7 @@ public class TetheringTest {
     @Mock private INetd mNetd;
     @Mock private UserManager mUserManager;
     @Mock private NetworkRequest mNetworkRequest;
+    @Mock private ConnectivityManager mCm;
 
     private final MockIpServerDependencies mIpServerDependencies =
             spy(new MockIpServerDependencies());
@@ -218,6 +226,7 @@ public class TetheringTest {
             if (Context.TELEPHONY_SERVICE.equals(name)) return mTelephonyManager;
             if (Context.USER_SERVICE.equals(name)) return mUserManager;
             if (Context.NETWORK_STATS_SERVICE.equals(name)) return mStatsManager;
+            if (Context.CONNECTIVITY_SERVICE.equals(name)) return mCm;
             return super.getSystemService(name);
         }
 
@@ -340,11 +349,6 @@ public class TetheringTest {
         }
 
         @Override
-        public INetworkPolicyManager getINetworkPolicyManager() {
-            return mPolicyManager;
-        }
-
-        @Override
         public INetd getINetd(Context context) {
             return mNetd;
         }
@@ -358,6 +362,12 @@ public class TetheringTest {
         public Context getContext() {
             return mServiceContext;
         }
+
+        @Override
+        public BluetoothAdapter getBluetoothAdapter() {
+            // TODO: add test for bluetooth tethering.
+            return null;
+        }
     }
 
     private static UpstreamNetworkState buildMobileUpstreamState(boolean withIPv4,
@@ -1349,6 +1359,50 @@ public class TetheringTest {
         workingWifiP2pGroupClient(false);
     }
 
+    private void setDataSaverEnabled(boolean enabled) {
+        final Intent intent = new Intent(ACTION_RESTRICT_BACKGROUND_CHANGED);
+        mServiceContext.sendBroadcastAsUser(intent, UserHandle.ALL);
+
+        final int status = enabled ? RESTRICT_BACKGROUND_STATUS_ENABLED
+                : RESTRICT_BACKGROUND_STATUS_DISABLED;
+        when(mCm.getRestrictBackgroundStatus()).thenReturn(status);
+        mLooper.dispatchAll();
+    }
+
+    @Test
+    public void testDataSaverChanged() {
+        // Start Tethering.
+        final UpstreamNetworkState upstreamState = buildMobileIPv4UpstreamState();
+        runUsbTethering(upstreamState);
+        assertContains(Arrays.asList(mTethering.getTetheredIfaces()), TEST_USB_IFNAME);
+        // Data saver is ON.
+        setDataSaverEnabled(true);
+        // Verify that tethering should be disabled.
+        verify(mUsbManager, times(1)).setCurrentFunctions(UsbManager.FUNCTION_NONE);
+        mTethering.interfaceRemoved(TEST_USB_IFNAME);
+        mLooper.dispatchAll();
+        assertEquals(mTethering.getTetheredIfaces(), new String[0]);
+        reset(mUsbManager);
+
+        runUsbTethering(upstreamState);
+        // Verify that user can start tethering again without turning OFF data saver.
+        assertContains(Arrays.asList(mTethering.getTetheredIfaces()), TEST_USB_IFNAME);
+
+        // If data saver is keep ON with change event, tethering should not be OFF this time.
+        setDataSaverEnabled(true);
+        verify(mUsbManager, times(0)).setCurrentFunctions(UsbManager.FUNCTION_NONE);
+        assertContains(Arrays.asList(mTethering.getTetheredIfaces()), TEST_USB_IFNAME);
+
+        // If data saver is turned OFF, it should not change tethering.
+        setDataSaverEnabled(false);
+        verify(mUsbManager, times(0)).setCurrentFunctions(UsbManager.FUNCTION_NONE);
+        assertContains(Arrays.asList(mTethering.getTetheredIfaces()), TEST_USB_IFNAME);
+    }
+
+    private static <T> void assertContains(Collection<T> collection, T element) {
+        assertTrue(element + " not found in " + collection, collection.contains(element));
+    }
+
     // TODO: Test that a request for hotspot mode doesn't interfere with an
     // already operating tethering mode interface.
 }
diff --git a/services/core/java/com/android/server/net/NetworkPolicyManagerService.java b/services/core/java/com/android/server/net/NetworkPolicyManagerService.java
index 9cbcd329649b..b18b8c6da900 100644
--- a/services/core/java/com/android/server/net/NetworkPolicyManagerService.java
+++ b/services/core/java/com/android/server/net/NetworkPolicyManagerService.java
@@ -2869,17 +2869,6 @@ public class NetworkPolicyManagerService extends INetworkPolicyManager.Stub {
     }
 
     @Override
-    public void onTetheringChanged(String iface, boolean tethering) {
-        // No need to enforce permission because setRestrictBackground() will do it.
-        synchronized (mUidRulesFirstLock) {
-            if (mRestrictBackground && tethering) {
-                Log.d(TAG, "Tethering on (" + iface +"); disable Data Saver");
-                setRestrictBackground(false);
-            }
-        }
-    }
-
-    @Override
     public void setRestrictBackground(boolean restrictBackground) {
         Trace.traceBegin(Trace.TRACE_TAG_NETWORK, "setRestrictBackground");
         try {