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Revert "Extract network observer code from NetworkManagementService."
authorRemi NGUYEN VAN <reminv@google.com>
Tue, 29 Jan 2019 10:12:13 +0000 (19:12 +0900)
committerRemi NGUYEN VAN <reminv@google.com>
Tue, 29 Jan 2019 10:19:09 +0000 (19:19 +0900)
This reverts commit d8bc829a85c9c9bb390e18b59ef1455b6d0b94ec.

Reason for revert: Refactoring was unnecessary
(Cherry-pick of aosp/888319 with conflicts with go/ag/4230697)

Test: m
Change-Id: Ib4e7da3274e49f25676505a08e6ce7e7b0dfdb8d

services/core/java/com/android/server/NetworkManagementService.java
services/net/java/android/net/shared/NetworkObserverRegistry.java [deleted file]

index c064453..b3997ef 100644 (file)
@@ -47,8 +47,10 @@ import android.app.ActivityManager;
 import android.content.Context;
 import android.net.ConnectivityManager;
 import android.net.INetd;
+import android.net.INetdUnsolicitedEventListener;
 import android.net.INetworkManagementEventObserver;
 import android.net.ITetheringStatsProvider;
+import android.net.InetAddresses;
 import android.net.InterfaceConfiguration;
 import android.net.InterfaceConfigurationParcel;
 import android.net.IpPrefix;
@@ -61,7 +63,6 @@ import android.net.RouteInfo;
 import android.net.TetherStatsParcel;
 import android.net.UidRange;
 import android.net.shared.NetdService;
-import android.net.shared.NetworkObserverRegistry;
 import android.os.BatteryStats;
 import android.os.Binder;
 import android.os.Handler;
@@ -206,13 +207,16 @@ public class NetworkManagementService extends INetworkManagementService.Stub
 
     private INetd mNetdService;
 
-    private NMSNetworkObserverRegistry mNetworkObserverRegistry;
+    private final NetdUnsolicitedEventListener mNetdUnsolicitedEventListener;
 
     private IBatteryStats mBatteryStats;
 
     private final Thread mThread;
     private CountDownLatch mConnectedSignal = new CountDownLatch(1);
 
+    private final RemoteCallbackList<INetworkManagementEventObserver> mObservers =
+            new RemoteCallbackList<>();
+
     private final NetworkStatsFactory mStatsFactory = new NetworkStatsFactory();
 
     @GuardedBy("mTetheringStatsProviders")
@@ -322,6 +326,8 @@ public class NetworkManagementService extends INetworkManagementService.Stub
 
         mDaemonHandler = new Handler(FgThread.get().getLooper());
 
+        mNetdUnsolicitedEventListener = new NetdUnsolicitedEventListener();
+
         // Add ourself to the Watchdog monitors.
         Watchdog.getInstance().addMonitor(this);
 
@@ -340,7 +346,7 @@ public class NetworkManagementService extends INetworkManagementService.Stub
         mFgHandler = null;
         mThread = null;
         mServices = null;
-        mNetworkObserverRegistry = null;
+        mNetdUnsolicitedEventListener = null;
     }
 
     static NetworkManagementService create(Context context, String socket, SystemServices services)
@@ -388,12 +394,14 @@ public class NetworkManagementService extends INetworkManagementService.Stub
 
     @Override
     public void registerObserver(INetworkManagementEventObserver observer) {
-        mNetworkObserverRegistry.registerObserver(observer);
+        mContext.enforceCallingOrSelfPermission(CONNECTIVITY_INTERNAL, TAG);
+        mObservers.register(observer);
     }
 
     @Override
     public void unregisterObserver(INetworkManagementEventObserver observer) {
-        mNetworkObserverRegistry.unregisterObserver(observer);
+        mContext.enforceCallingOrSelfPermission(CONNECTIVITY_INTERNAL, TAG);
+        mObservers.unregister(observer);
     }
 
     @FunctionalInterface
@@ -401,101 +409,127 @@ public class NetworkManagementService extends INetworkManagementService.Stub
         public void sendCallback(INetworkManagementEventObserver o) throws RemoteException;
     }
 
-    private class NMSNetworkObserverRegistry extends NetworkObserverRegistry {
-        NMSNetworkObserverRegistry(Context context, Handler handler, INetd netd)
-                throws RemoteException {
-            super(context, handler, netd);
+    private void invokeForAllObservers(NetworkManagementEventCallback eventCallback) {
+        final int length = mObservers.beginBroadcast();
+        try {
+            for (int i = 0; i < length; i++) {
+                try {
+                    eventCallback.sendCallback(mObservers.getBroadcastItem(i));
+                } catch (RemoteException | RuntimeException e) {
+                }
+            }
+        } finally {
+            mObservers.finishBroadcast();
         }
+    }
 
-        /**
-         * Notify our observers of a change in the data activity state of the interface
-         */
-        @Override
-        public void notifyInterfaceClassActivity(int type, boolean isActive, long tsNanos,
-                int uid, boolean fromRadio) {
-            final boolean isMobile = ConnectivityManager.isNetworkTypeMobile(type);
-            int powerState = isActive
-                    ? DataConnectionRealTimeInfo.DC_POWER_STATE_HIGH
-                    : DataConnectionRealTimeInfo.DC_POWER_STATE_LOW;
-
-            if (isMobile) {
-                if (!fromRadio) {
-                    if (mMobileActivityFromRadio) {
-                        // If this call is not coming from a report from the radio itself, but we
-                        // have previously received reports from the radio, then we will take the
-                        // power state to just be whatever the radio last reported.
-                        powerState = mLastPowerStateFromRadio;
-                    }
-                } else {
-                    mMobileActivityFromRadio = true;
+    /**
+     * Notify our observers of an interface status change
+     */
+    private void notifyInterfaceStatusChanged(String iface, boolean up) {
+        invokeForAllObservers(o -> o.interfaceStatusChanged(iface, up));
+    }
+
+    /**
+     * Notify our observers of an interface link state change
+     * (typically, an Ethernet cable has been plugged-in or unplugged).
+     */
+    private void notifyInterfaceLinkStateChanged(String iface, boolean up) {
+        invokeForAllObservers(o -> o.interfaceLinkStateChanged(iface, up));
+    }
+
+    /**
+     * Notify our observers of an interface addition.
+     */
+    private void notifyInterfaceAdded(String iface) {
+        invokeForAllObservers(o -> o.interfaceAdded(iface));
+    }
+
+    /**
+     * Notify our observers of an interface removal.
+     */
+    private void notifyInterfaceRemoved(String iface) {
+        // netd already clears out quota and alerts for removed ifaces; update
+        // our sanity-checking state.
+        mActiveAlerts.remove(iface);
+        mActiveQuotas.remove(iface);
+        invokeForAllObservers(o -> o.interfaceRemoved(iface));
+    }
+
+    /**
+     * Notify our observers of a limit reached.
+     */
+    private void notifyLimitReached(String limitName, String iface) {
+        invokeForAllObservers(o -> o.limitReached(limitName, iface));
+    }
+
+    /**
+     * Notify our observers of a change in the data activity state of the interface
+     */
+    private void notifyInterfaceClassActivity(int type, boolean isActive, long tsNanos,
+            int uid, boolean fromRadio) {
+        final boolean isMobile = ConnectivityManager.isNetworkTypeMobile(type);
+        int powerState = isActive
+                ? DataConnectionRealTimeInfo.DC_POWER_STATE_HIGH
+                : DataConnectionRealTimeInfo.DC_POWER_STATE_LOW;
+        if (isMobile) {
+            if (!fromRadio) {
+                if (mMobileActivityFromRadio) {
+                    // If this call is not coming from a report from the radio itself, but we
+                    // have previously received reports from the radio, then we will take the
+                    // power state to just be whatever the radio last reported.
+                    powerState = mLastPowerStateFromRadio;
                 }
-                if (mLastPowerStateFromRadio != powerState) {
-                    mLastPowerStateFromRadio = powerState;
-                    try {
-                        getBatteryStats().noteMobileRadioPowerState(powerState, tsNanos, uid);
-                    } catch (RemoteException e) {
-                    }
+            } else {
+                mMobileActivityFromRadio = true;
+            }
+            if (mLastPowerStateFromRadio != powerState) {
+                mLastPowerStateFromRadio = powerState;
+                try {
+                    getBatteryStats().noteMobileRadioPowerState(powerState, tsNanos, uid);
+                } catch (RemoteException e) {
                 }
                 StatsLog.write_non_chained(StatsLog.MOBILE_RADIO_POWER_STATE_CHANGED, uid, null,
                         powerState);
             }
+        }
 
-            if (ConnectivityManager.isNetworkTypeWifi(type)) {
-                if (mLastPowerStateFromWifi != powerState) {
-                    mLastPowerStateFromWifi = powerState;
-                    try {
-                        getBatteryStats().noteWifiRadioPowerState(powerState, tsNanos, uid);
-                    } catch (RemoteException e) {
-                    }
+        if (ConnectivityManager.isNetworkTypeWifi(type)) {
+            if (mLastPowerStateFromWifi != powerState) {
+                mLastPowerStateFromWifi = powerState;
+                try {
+                    getBatteryStats().noteWifiRadioPowerState(powerState, tsNanos, uid);
+                } catch (RemoteException e) {
                 }
                 StatsLog.write_non_chained(StatsLog.WIFI_RADIO_POWER_STATE_CHANGED, uid, null,
                         powerState);
             }
+        }
 
-            if (!isMobile || fromRadio || !mMobileActivityFromRadio) {
-                // Report the change in data activity.  We don't do this if this is a change
-                // on the mobile network, that is not coming from the radio itself, and we
-                // have previously seen change reports from the radio.  In that case only
-                // the radio is the authority for the current state.
-                final boolean active = isActive;
-                super.notifyInterfaceClassActivity(type, isActive, tsNanos, uid, fromRadio);
-            }
+        if (!isMobile || fromRadio || !mMobileActivityFromRadio) {
+            // Report the change in data activity.  We don't do this if this is a change
+            // on the mobile network, that is not coming from the radio itself, and we
+            // have previously seen change reports from the radio.  In that case only
+            // the radio is the authority for the current state.
+            final boolean active = isActive;
+            invokeForAllObservers(o -> o.interfaceClassDataActivityChanged(
+                    Integer.toString(type), active, tsNanos));
+        }
 
-            boolean report = false;
-            synchronized (mIdleTimerLock) {
-                if (mActiveIdleTimers.isEmpty()) {
-                    // If there are no idle timers, we are not monitoring activity, so we
-                    // are always considered active.
-                    isActive = true;
-                }
-                if (mNetworkActive != isActive) {
-                    mNetworkActive = isActive;
-                    report = isActive;
-                }
+        boolean report = false;
+        synchronized (mIdleTimerLock) {
+            if (mActiveIdleTimers.isEmpty()) {
+                // If there are no idle timers, we are not monitoring activity, so we
+                // are always considered active.
+                isActive = true;
             }
-            if (report) {
-                reportNetworkActive();
+            if (mNetworkActive != isActive) {
+                mNetworkActive = isActive;
+                report = isActive;
             }
         }
-
-        /**
-         * Notify our observers of an interface removal.
-         */
-        @Override
-        public void notifyInterfaceRemoved(String iface) {
-            // netd already clears out quota and alerts for removed ifaces; update
-            // our sanity-checking state.
-            mActiveAlerts.remove(iface);
-            mActiveQuotas.remove(iface);
-            super.notifyInterfaceRemoved(iface);
-        }
-
-        @Override
-        public void onStrictCleartextDetected(int uid, String hex) throws RemoteException {
-            // Don't need to post to mDaemonHandler because the only thing
-            // that notifyCleartextNetwork does is post to a handler
-            ActivityManager.getService().notifyCleartextNetwork(uid,
-                    HexDump.hexStringToByteArray(hex));
+        if (report) {
+            reportNetworkActive();
         }
     }
 
@@ -524,8 +558,7 @@ public class NetworkManagementService extends INetworkManagementService.Stub
                 return;
             }
             // No current code examines the interface parameter in a global alert. Just pass null.
-            mDaemonHandler.post(() -> mNetworkObserverRegistry.notifyLimitReached(
-                    LIMIT_GLOBAL_ALERT, null));
+            mDaemonHandler.post(() -> notifyLimitReached(LIMIT_GLOBAL_ALERT, null));
         }
     }
 
@@ -557,11 +590,10 @@ public class NetworkManagementService extends INetworkManagementService.Stub
     private void connectNativeNetdService() {
         mNetdService = mServices.getNetd();
         try {
-            mNetworkObserverRegistry = new NMSNetworkObserverRegistry(
-                    mContext, mDaemonHandler, mNetdService);
-            if (DBG) Slog.d(TAG, "Registered NetworkObserverRegistry");
+            mNetdService.registerUnsolicitedEventListener(mNetdUnsolicitedEventListener);
+            if (DBG) Slog.d(TAG, "Register unsolicited event listener");
         } catch (RemoteException | ServiceSpecificException e) {
-            Slog.wtf(TAG, "Failed to register NetworkObserverRegistry: " + e);
+            Slog.e(TAG, "Failed to set Netd unsolicited event listener " + e);
         }
     }
 
@@ -665,6 +697,118 @@ public class NetworkManagementService extends INetworkManagementService.Stub
 
     }
 
+    /**
+     * Notify our observers of a new or updated interface address.
+     */
+    private void notifyAddressUpdated(String iface, LinkAddress address) {
+        invokeForAllObservers(o -> o.addressUpdated(iface, address));
+    }
+
+    /**
+     * Notify our observers of a deleted interface address.
+     */
+    private void notifyAddressRemoved(String iface, LinkAddress address) {
+        invokeForAllObservers(o -> o.addressRemoved(iface, address));
+    }
+
+    /**
+     * Notify our observers of DNS server information received.
+     */
+    private void notifyInterfaceDnsServerInfo(String iface, long lifetime, String[] addresses) {
+        invokeForAllObservers(o -> o.interfaceDnsServerInfo(iface, lifetime, addresses));
+    }
+
+    /**
+     * Notify our observers of a route change.
+     */
+    private void notifyRouteChange(boolean updated, RouteInfo route) {
+        if (updated) {
+            invokeForAllObservers(o -> o.routeUpdated(route));
+        } else {
+            invokeForAllObservers(o -> o.routeRemoved(route));
+        }
+    }
+
+    private class NetdUnsolicitedEventListener extends INetdUnsolicitedEventListener.Stub {
+        @Override
+        public void onInterfaceClassActivityChanged(boolean isActive,
+                int label, long timestamp, int uid) throws RemoteException {
+            final long timestampNanos;
+            if (timestamp <= 0) {
+                timestampNanos = SystemClock.elapsedRealtimeNanos();
+            } else {
+                timestampNanos = timestamp;
+            }
+            mDaemonHandler.post(() ->
+                    notifyInterfaceClassActivity(label, isActive, timestampNanos, uid, false));
+        }
+
+        @Override
+        public void onQuotaLimitReached(String alertName, String ifName)
+                throws RemoteException {
+            mDaemonHandler.post(() -> notifyLimitReached(alertName, ifName));
+        }
+
+        @Override
+        public void onInterfaceDnsServerInfo(String ifName,
+                long lifetime, String[] servers) throws RemoteException {
+            mDaemonHandler.post(() -> notifyInterfaceDnsServerInfo(ifName, lifetime, servers));
+        }
+
+        @Override
+        public void onInterfaceAddressUpdated(String addr,
+                String ifName, int flags, int scope) throws RemoteException {
+            final LinkAddress address = new LinkAddress(addr, flags, scope);
+            mDaemonHandler.post(() -> notifyAddressUpdated(ifName, address));
+        }
+
+        @Override
+        public void onInterfaceAddressRemoved(String addr,
+                String ifName, int flags, int scope) throws RemoteException {
+            final LinkAddress address = new LinkAddress(addr, flags, scope);
+            mDaemonHandler.post(() -> notifyAddressRemoved(ifName, address));
+        }
+
+        @Override
+        public void onInterfaceAdded(String ifName) throws RemoteException {
+            mDaemonHandler.post(() -> notifyInterfaceAdded(ifName));
+        }
+
+        @Override
+        public void onInterfaceRemoved(String ifName) throws RemoteException {
+            mDaemonHandler.post(() -> notifyInterfaceRemoved(ifName));
+        }
+
+        @Override
+        public void onInterfaceChanged(String ifName, boolean up)
+                throws RemoteException {
+            mDaemonHandler.post(() -> notifyInterfaceStatusChanged(ifName, up));
+        }
+
+        @Override
+        public void onInterfaceLinkStateChanged(String ifName, boolean up)
+                throws RemoteException {
+            mDaemonHandler.post(() -> notifyInterfaceLinkStateChanged(ifName, up));
+        }
+
+        @Override
+        public void onRouteChanged(boolean updated,
+                String route, String gateway, String ifName) throws RemoteException {
+            final RouteInfo processRoute = new RouteInfo(new IpPrefix(route),
+                    ("".equals(gateway)) ? null : InetAddresses.parseNumericAddress(gateway),
+                    ifName);
+            mDaemonHandler.post(() -> notifyRouteChange(updated, processRoute));
+        }
+
+        @Override
+        public void onStrictCleartextDetected(int uid, String hex) throws RemoteException {
+            // Don't need to post to mDaemonHandler because the only thing
+            // that notifyCleartextNetwork does is post to a handler
+            ActivityManager.getService().notifyCleartextNetwork(uid,
+                    HexDump.hexStringToByteArray(hex));
+        }
+    }
+
     //
     // Netd Callback handling
     //
@@ -713,18 +857,16 @@ public class NetworkManagementService extends INetworkManagementService.Stub
                         throw new IllegalStateException(errorMessage);
                     }
                     if (cooked[2].equals("added")) {
-                        mNetworkObserverRegistry.notifyInterfaceAdded(cooked[3]);
+                        notifyInterfaceAdded(cooked[3]);
                         return true;
                     } else if (cooked[2].equals("removed")) {
-                        mNetworkObserverRegistry.notifyInterfaceRemoved(cooked[3]);
+                        notifyInterfaceRemoved(cooked[3]);
                         return true;
                     } else if (cooked[2].equals("changed") && cooked.length == 5) {
-                        mNetworkObserverRegistry.notifyInterfaceStatusChanged(
-                                cooked[3], cooked[4].equals("up"));
+                        notifyInterfaceStatusChanged(cooked[3], cooked[4].equals("up"));
                         return true;
                     } else if (cooked[2].equals("linkstate") && cooked.length == 5) {
-                        mNetworkObserverRegistry.notifyInterfaceLinkStateChanged(
-                                cooked[3], cooked[4].equals("up"));
+                        notifyInterfaceLinkStateChanged(cooked[3], cooked[4].equals("up"));
                         return true;
                     }
                     throw new IllegalStateException(errorMessage);
@@ -738,7 +880,7 @@ public class NetworkManagementService extends INetworkManagementService.Stub
                         throw new IllegalStateException(errorMessage);
                     }
                     if (cooked[2].equals("alert")) {
-                        mNetworkObserverRegistry.notifyLimitReached(cooked[3], cooked[4]);
+                        notifyLimitReached(cooked[3], cooked[4]);
                         return true;
                     }
                     throw new IllegalStateException(errorMessage);
@@ -764,9 +906,8 @@ public class NetworkManagementService extends INetworkManagementService.Stub
                         timestampNanos = SystemClock.elapsedRealtimeNanos();
                     }
                     boolean isActive = cooked[2].equals("active");
-                    mNetworkObserverRegistry.notifyInterfaceClassActivity(
-                            Integer.parseInt(cooked[3]), isActive,
-                            timestampNanos, processUid, false);
+                    notifyInterfaceClassActivity(Integer.parseInt(cooked[3]),
+                            isActive, timestampNanos, processUid, false);
                     return true;
                     // break;
             case NetdResponseCode.InterfaceAddressChange:
@@ -792,9 +933,9 @@ public class NetworkManagementService extends INetworkManagementService.Stub
                     }
 
                     if (cooked[2].equals("updated")) {
-                        mNetworkObserverRegistry.notifyAddressUpdated(iface, address);
+                        notifyAddressUpdated(iface, address);
                     } else {
-                        mNetworkObserverRegistry.notifyAddressRemoved(iface, address);
+                        notifyAddressRemoved(iface, address);
                     }
                     return true;
                     // break;
@@ -814,8 +955,7 @@ public class NetworkManagementService extends INetworkManagementService.Stub
                             throw new IllegalStateException(errorMessage);
                         }
                         String[] servers = cooked[5].split(",");
-                        mNetworkObserverRegistry.notifyInterfaceDnsServerInfo(
-                                cooked[3], lifetime, servers);
+                        notifyInterfaceDnsServerInfo(cooked[3], lifetime, servers);
                     }
                     return true;
                     // break;
@@ -854,8 +994,7 @@ public class NetworkManagementService extends INetworkManagementService.Stub
                             InetAddress gateway = null;
                             if (via != null) gateway = InetAddress.parseNumericAddress(via);
                             RouteInfo route = new RouteInfo(new IpPrefix(cooked[3]), gateway, dev);
-                            mNetworkObserverRegistry.notifyRouteChange(
-                                    cooked[2].equals("updated"), route);
+                            notifyRouteChange(cooked[2].equals("updated"), route);
                             return true;
                         } catch (IllegalArgumentException e) {}
                     }
@@ -1318,8 +1457,8 @@ public class NetworkManagementService extends INetworkManagementService.Stub
             if (ConnectivityManager.isNetworkTypeMobile(type)) {
                 mNetworkActive = false;
             }
-            mDaemonHandler.post(() -> mNetworkObserverRegistry.notifyInterfaceClassActivity(
-                    type, true /* isActive */, SystemClock.elapsedRealtimeNanos(), -1, false));
+            mDaemonHandler.post(() -> notifyInterfaceClassActivity(type, true,
+                    SystemClock.elapsedRealtimeNanos(), -1, false));
         }
     }
 
@@ -1342,9 +1481,8 @@ public class NetworkManagementService extends INetworkManagementService.Stub
                 throw new IllegalStateException(e);
             }
             mActiveIdleTimers.remove(iface);
-            mDaemonHandler.post(() -> mNetworkObserverRegistry.notifyInterfaceClassActivity(
-                    params.type, false /* isActive */, SystemClock.elapsedRealtimeNanos(), -1,
-                    false));
+            mDaemonHandler.post(() -> notifyInterfaceClassActivity(params.type, false,
+                    SystemClock.elapsedRealtimeNanos(), -1, false));
         }
     }
 
diff --git a/services/net/java/android/net/shared/NetworkObserverRegistry.java b/services/net/java/android/net/shared/NetworkObserverRegistry.java
deleted file mode 100644 (file)
index 36945f5..0000000
+++ /dev/null
@@ -1,255 +0,0 @@
-/*
- * Copyright (C) 2019 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package android.net.shared;
-
-import static android.Manifest.permission.NETWORK_STACK;
-
-import android.content.Context;
-import android.net.INetd;
-import android.net.INetdUnsolicitedEventListener;
-import android.net.INetworkManagementEventObserver;
-import android.net.InetAddresses;
-import android.net.IpPrefix;
-import android.net.LinkAddress;
-import android.net.RouteInfo;
-import android.os.Handler;
-import android.os.RemoteCallbackList;
-import android.os.RemoteException;
-import android.os.SystemClock;
-
-/**
- * A class for reporting network events to clients.
- *
- * Implements INetdUnsolicitedEventListener and registers with netd, and relays those events to
- * all INetworkManagementEventObserver objects that have registered with it.
- *
- * TODO: Make the notifyXyz methods protected once subclasses (e.g., the NetworkManagementService
- * subclass) no longer call them directly.
- *
- * TODO: change from RemoteCallbackList to direct in-process callbacks.
- */
-public class NetworkObserverRegistry extends INetdUnsolicitedEventListener.Stub {
-
-    private final Context mContext;
-    private final Handler mDaemonHandler;
-    private static final String TAG = "NetworkObserverRegistry";
-
-    /**
-     * Constructs a new instance and registers it with netd.
-     * This method should only be called once since netd will reject multiple registrations from
-     * the same process.
-     */
-    public NetworkObserverRegistry(Context context, Handler handler, INetd netd)
-            throws RemoteException {
-        mContext = context;
-        mDaemonHandler = handler;
-        netd.registerUnsolicitedEventListener(this);
-    }
-
-    private final RemoteCallbackList<INetworkManagementEventObserver> mObservers =
-            new RemoteCallbackList<>();
-
-    /**
-     * Registers the specified observer and start sending callbacks to it.
-     * This method may be called on any thread.
-     */
-    public void registerObserver(INetworkManagementEventObserver observer) {
-        mContext.enforceCallingOrSelfPermission(NETWORK_STACK, TAG);
-        mObservers.register(observer);
-    }
-
-    /**
-     * Unregisters the specified observer and stop sending callbacks to it.
-     * This method may be called on any thread.
-     */
-    public void unregisterObserver(INetworkManagementEventObserver observer) {
-        mContext.enforceCallingOrSelfPermission(NETWORK_STACK, TAG);
-        mObservers.unregister(observer);
-    }
-
-    @FunctionalInterface
-    private interface NetworkManagementEventCallback {
-        void sendCallback(INetworkManagementEventObserver o) throws RemoteException;
-    }
-
-    private void invokeForAllObservers(NetworkManagementEventCallback eventCallback) {
-        final int length = mObservers.beginBroadcast();
-        try {
-            for (int i = 0; i < length; i++) {
-                try {
-                    eventCallback.sendCallback(mObservers.getBroadcastItem(i));
-                } catch (RemoteException | RuntimeException e) {
-                }
-            }
-        } finally {
-            mObservers.finishBroadcast();
-        }
-    }
-
-    /**
-     * Notify our observers of a change in the data activity state of the interface
-     */
-    public void notifyInterfaceClassActivity(int type, boolean isActive, long tsNanos,
-            int uid, boolean fromRadio) {
-        invokeForAllObservers(o -> o.interfaceClassDataActivityChanged(
-                Integer.toString(type), isActive, tsNanos));
-    }
-
-    @Override
-    public void onInterfaceClassActivityChanged(boolean isActive,
-            int label, long timestamp, int uid) throws RemoteException {
-        final long timestampNanos;
-        if (timestamp <= 0) {
-            timestampNanos = SystemClock.elapsedRealtimeNanos();
-        } else {
-            timestampNanos = timestamp;
-        }
-        mDaemonHandler.post(() -> notifyInterfaceClassActivity(label, isActive,
-                timestampNanos, uid, false));
-    }
-
-    /**
-     * Notify our observers of a limit reached.
-     */
-    @Override
-    public void onQuotaLimitReached(String alertName, String ifName) throws RemoteException {
-        mDaemonHandler.post(() -> notifyLimitReached(alertName, ifName));
-    }
-
-    /**
-     * Notify our observers of a limit reached.
-     */
-    public void notifyLimitReached(String limitName, String iface) {
-        invokeForAllObservers(o -> o.limitReached(limitName, iface));
-    }
-
-    @Override
-    public void onInterfaceDnsServerInfo(String ifName,
-            long lifetime, String[] servers) throws RemoteException {
-        mDaemonHandler.post(() -> notifyInterfaceDnsServerInfo(ifName, lifetime, servers));
-    }
-
-    /**
-     * Notify our observers of DNS server information received.
-     */
-    public void notifyInterfaceDnsServerInfo(String iface, long lifetime, String[] addresses) {
-        invokeForAllObservers(o -> o.interfaceDnsServerInfo(iface, lifetime, addresses));
-    }
-
-    @Override
-    public void onInterfaceAddressUpdated(String addr,
-            String ifName, int flags, int scope) throws RemoteException {
-        final LinkAddress address = new LinkAddress(addr, flags, scope);
-        mDaemonHandler.post(() -> notifyAddressUpdated(ifName, address));
-    }
-
-    /**
-     * Notify our observers of a new or updated interface address.
-     */
-    public void notifyAddressUpdated(String iface, LinkAddress address) {
-        invokeForAllObservers(o -> o.addressUpdated(iface, address));
-    }
-
-    @Override
-    public void onInterfaceAddressRemoved(String addr,
-            String ifName, int flags, int scope) throws RemoteException {
-        final LinkAddress address = new LinkAddress(addr, flags, scope);
-        mDaemonHandler.post(() -> notifyAddressRemoved(ifName, address));
-    }
-
-    /**
-     * Notify our observers of a deleted interface address.
-     */
-    public void notifyAddressRemoved(String iface, LinkAddress address) {
-        invokeForAllObservers(o -> o.addressRemoved(iface, address));
-    }
-
-
-    @Override
-    public void onInterfaceAdded(String ifName) throws RemoteException {
-        mDaemonHandler.post(() -> notifyInterfaceAdded(ifName));
-    }
-
-    /**
-     * Notify our observers of an interface addition.
-     */
-    public void notifyInterfaceAdded(String iface) {
-        invokeForAllObservers(o -> o.interfaceAdded(iface));
-    }
-
-    @Override
-    public void onInterfaceRemoved(String ifName) throws RemoteException {
-        mDaemonHandler.post(() -> notifyInterfaceRemoved(ifName));
-    }
-
-    /**
-     * Notify our observers of an interface removal.
-     */
-    public void notifyInterfaceRemoved(String iface) {
-        invokeForAllObservers(o -> o.interfaceRemoved(iface));
-    }
-
-    @Override
-    public void onInterfaceChanged(String ifName, boolean up) throws RemoteException {
-        mDaemonHandler.post(() -> notifyInterfaceStatusChanged(ifName, up));
-    }
-
-    /**
-     * Notify our observers of an interface status change
-     */
-    public void notifyInterfaceStatusChanged(String iface, boolean up) {
-        invokeForAllObservers(o -> o.interfaceStatusChanged(iface, up));
-    }
-
-    @Override
-    public void onInterfaceLinkStateChanged(String ifName, boolean up) throws RemoteException {
-        mDaemonHandler.post(() -> notifyInterfaceLinkStateChanged(ifName, up));
-    }
-
-    /**
-     * Notify our observers of an interface link state change
-     * (typically, an Ethernet cable has been plugged-in or unplugged).
-     */
-    public void notifyInterfaceLinkStateChanged(String iface, boolean up) {
-        invokeForAllObservers(o -> o.interfaceLinkStateChanged(iface, up));
-    }
-
-    @Override
-    public void onRouteChanged(boolean updated,
-            String route, String gateway, String ifName) throws RemoteException {
-        final RouteInfo processRoute = new RouteInfo(new IpPrefix(route),
-                ("".equals(gateway)) ? null : InetAddresses.parseNumericAddress(gateway),
-                ifName);
-        mDaemonHandler.post(() -> notifyRouteChange(updated, processRoute));
-    }
-
-    /**
-     * Notify our observers of a route change.
-     */
-    public void notifyRouteChange(boolean updated, RouteInfo route) {
-        if (updated) {
-            invokeForAllObservers(o -> o.routeUpdated(route));
-        } else {
-            invokeForAllObservers(o -> o.routeRemoved(route));
-        }
-    }
-
-    @Override
-    public void onStrictCleartextDetected(int uid, String hex) throws RemoteException {
-        // Don't do anything here because this is not a method of INetworkManagementEventObserver.
-        // Only the NMS subclass will implement this.
-    }
-}