diff --git a/framework-t/src/android/app/usage/NetworkStats.java b/framework-t/src/android/app/usage/NetworkStats.java
index 2b6570a..74fe4bd 100644
--- a/framework-t/src/android/app/usage/NetworkStats.java
+++ b/framework-t/src/android/app/usage/NetworkStats.java
@@ -17,6 +17,7 @@
 package android.app.usage;
 
 import android.annotation.IntDef;
+import android.annotation.Nullable;
 import android.content.Context;
 import android.net.INetworkStatsService;
 import android.net.INetworkStatsSession;
@@ -474,10 +475,11 @@
 
     /**
      * Fills the recycled bucket with data of the next bin in the enumeration.
-     * @param bucketOut Bucket to be filled with data.
+     * @param bucketOut Bucket to be filled with data. If null, the method does
+     *                  nothing and returning false.
      * @return true if successfully filled the bucket, false otherwise.
      */
-    public boolean getNextBucket(Bucket bucketOut) {
+    public boolean getNextBucket(@Nullable Bucket bucketOut) {
         if (mSummary != null) {
             return getNextSummaryBucket(bucketOut);
         } else {
@@ -651,7 +653,7 @@
      * @param bucketOut Next item will be set here.
      * @return true if a next item could be set.
      */
-    private boolean getNextSummaryBucket(Bucket bucketOut) {
+    private boolean getNextSummaryBucket(@Nullable Bucket bucketOut) {
         if (bucketOut != null && mEnumerationIndex < mSummary.size()) {
             mRecycledSummaryEntry = mSummary.getValues(mEnumerationIndex++, mRecycledSummaryEntry);
             fillBucketFromSummaryEntry(bucketOut);
@@ -678,7 +680,7 @@
      * @param bucketOut Next item will be set here.
      * @return true if a next item could be set.
      */
-    private boolean getNextHistoryBucket(Bucket bucketOut) {
+    private boolean getNextHistoryBucket(@Nullable Bucket bucketOut) {
         if (bucketOut != null && mHistory != null) {
             if (mEnumerationIndex < mHistory.size()) {
                 mRecycledHistoryEntry = mHistory.getValues(mEnumerationIndex++,
diff --git a/framework-t/src/android/app/usage/NetworkStatsManager.java b/framework-t/src/android/app/usage/NetworkStatsManager.java
index bf518b2..f41475b 100644
--- a/framework-t/src/android/app/usage/NetworkStatsManager.java
+++ b/framework-t/src/android/app/usage/NetworkStatsManager.java
@@ -290,7 +290,7 @@
      *         statistics collection.
      */
     @WorkerThread
-    public Bucket querySummaryForDevice(int networkType, String subscriberId,
+    public Bucket querySummaryForDevice(int networkType, @Nullable String subscriberId,
             long startTime, long endTime) throws SecurityException, RemoteException {
         NetworkTemplate template;
         try {
@@ -335,8 +335,8 @@
      *         statistics collection.
      */
     @WorkerThread
-    public Bucket querySummaryForUser(int networkType, String subscriberId, long startTime,
-            long endTime) throws SecurityException, RemoteException {
+    public Bucket querySummaryForUser(int networkType, @Nullable String subscriberId,
+            long startTime, long endTime) throws SecurityException, RemoteException {
         NetworkTemplate template;
         try {
             template = createTemplate(networkType, subscriberId);
@@ -384,7 +384,7 @@
      *         statistics collection.
      */
     @WorkerThread
-    public NetworkStats querySummary(int networkType, String subscriberId, long startTime,
+    public NetworkStats querySummary(int networkType, @Nullable String subscriberId, long startTime,
             long endTime) throws SecurityException, RemoteException {
         NetworkTemplate template;
         try {
@@ -508,15 +508,17 @@
      *
      * @see #queryDetailsForUidTagState(int, String, long, long, int, int, int)
      */
+    @NonNull
     @WorkerThread
-    public NetworkStats queryDetailsForUid(int networkType, String subscriberId,
+    public NetworkStats queryDetailsForUid(int networkType, @Nullable String subscriberId,
             long startTime, long endTime, int uid) throws SecurityException {
         return queryDetailsForUidTagState(networkType, subscriberId, startTime, endTime, uid,
             NetworkStats.Bucket.TAG_NONE, NetworkStats.Bucket.STATE_ALL);
     }
 
     /** @hide */
-    public NetworkStats queryDetailsForUid(NetworkTemplate template,
+    @NonNull
+    public NetworkStats queryDetailsForUid(@NonNull NetworkTemplate template,
             long startTime, long endTime, int uid) throws SecurityException {
         return queryDetailsForUidTagState(template, startTime, endTime, uid,
                 NetworkStats.Bucket.TAG_NONE, NetworkStats.Bucket.STATE_ALL);
@@ -524,23 +526,59 @@
 
     /**
      * Query network usage statistics details for a given uid and tag.
+     *
+     * This may take a long time, and apps should avoid calling this on their main thread.
+     * Only usable for uids belonging to calling user. Result is not aggregated over time.
+     * This means buckets' start and end timestamps are going to be between 'startTime' and
+     * 'endTime' parameters. The uid is going to be the same as the 'uid' parameter, the tag
+     * the same as the 'tag' parameter, and the state the same as the 'state' parameter.
+     * defaultNetwork is going to be {@link NetworkStats.Bucket#DEFAULT_NETWORK_ALL},
+     * metered is going to be {@link NetworkStats.Bucket#METERED_ALL}, and
+     * roaming is going to be {@link NetworkStats.Bucket#ROAMING_ALL}.
+     * <p>Only includes buckets that atomically occur in the inclusive time range. Doesn't
+     * interpolate across partial buckets. Since bucket length is in the order of hours, this
+     * method cannot be used to measure data usage on a fine grained time scale.
      * This may take a long time, and apps should avoid calling this on their main thread.
      *
-     * @see #queryDetailsForUidTagState(int, String, long, long, int, int, int)
+     * @param networkType As defined in {@link ConnectivityManager}, e.g.
+     *            {@link ConnectivityManager#TYPE_MOBILE}, {@link ConnectivityManager#TYPE_WIFI}
+     *            etc.
+     * @param subscriberId If applicable, the subscriber id of the network interface.
+     *                     <p>Starting with API level 29, the {@code subscriberId} is guarded by
+     *                     additional restrictions. Calling apps that do not meet the new
+     *                     requirements to access the {@code subscriberId} can provide a {@code
+     *                     null} value when querying for the mobile network type to receive usage
+     *                     for all mobile networks. For additional details see {@link
+     *                     TelephonyManager#getSubscriberId()}.
+     *                     <p>Starting with API level 31, calling apps can provide a
+     *                     {@code subscriberId} with wifi network type to receive usage for
+     *                     wifi networks which is under the given subscription if applicable.
+     *                     Otherwise, pass {@code null} when querying all wifi networks.
+     * @param startTime Start of period. Defined in terms of "Unix time", see
+     *            {@link java.lang.System#currentTimeMillis}.
+     * @param endTime End of period. Defined in terms of "Unix time", see
+     *            {@link java.lang.System#currentTimeMillis}.
+     * @param uid UID of app
+     * @param tag TAG of interest. Use {@link NetworkStats.Bucket#TAG_NONE} for aggregated data
+     *            across all the tags.
+     * @return Statistics which is described above.
+     * @throws SecurityException if permissions are insufficient to read network statistics.
      */
+    @NonNull
     @WorkerThread
-    public NetworkStats queryDetailsForUidTag(int networkType, String subscriberId,
+    public NetworkStats queryDetailsForUidTag(int networkType, @Nullable String subscriberId,
             long startTime, long endTime, int uid, int tag) throws SecurityException {
         return queryDetailsForUidTagState(networkType, subscriberId, startTime, endTime, uid,
             tag, NetworkStats.Bucket.STATE_ALL);
     }
 
     /**
-     * Query network usage statistics details for a given uid, tag, and state. Only usable for uids
-     * belonging to calling user. Result is not aggregated over time. This means buckets' start and
-     * end timestamps are going to be between 'startTime' and 'endTime' parameters. The uid is going
-     * to be the same as the 'uid' parameter, the tag the same as the 'tag' parameter, and the state
-     * the same as the 'state' parameter.
+     * Query network usage statistics details for a given uid, tag, and state.
+     *
+     * Only usable for uids belonging to calling user. Result is not aggregated over time.
+     * This means buckets' start and end timestamps are going to be between 'startTime' and
+     * 'endTime' parameters. The uid is going to be the same as the 'uid' parameter, the tag
+     * the same as the 'tag' parameter, and the state the same as the 'state' parameter.
      * defaultNetwork is going to be {@link NetworkStats.Bucket#DEFAULT_NETWORK_ALL},
      * metered is going to be {@link NetworkStats.Bucket#METERED_ALL}, and
      * roaming is going to be {@link NetworkStats.Bucket#ROAMING_ALL}.
@@ -572,11 +610,12 @@
      *            across all the tags.
      * @param state state of interest. Use {@link NetworkStats.Bucket#STATE_ALL} to aggregate
      *            traffic from all states.
-     * @return Statistics object or null if an error happened during statistics collection.
+     * @return Statistics which is described above.
      * @throws SecurityException if permissions are insufficient to read network statistics.
      */
+    @NonNull
     @WorkerThread
-    public NetworkStats queryDetailsForUidTagState(int networkType, String subscriberId,
+    public NetworkStats queryDetailsForUidTagState(int networkType, @Nullable String subscriberId,
             long startTime, long endTime, int uid, int tag, int state) throws SecurityException {
         NetworkTemplate template;
         template = createTemplate(networkType, subscriberId);
@@ -669,7 +708,7 @@
      *         statistics collection.
      */
     @WorkerThread
-    public NetworkStats queryDetails(int networkType, String subscriberId, long startTime,
+    public NetworkStats queryDetails(int networkType, @Nullable String subscriberId, long startTime,
             long endTime) throws SecurityException, RemoteException {
         NetworkTemplate template;
         try {
@@ -698,7 +737,7 @@
      *
      * @hide
      */
-    @SystemApi
+    @SystemApi(client = MODULE_LIBRARIES)
     @RequiresPermission(anyOf = {
             NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK,
             android.Manifest.permission.NETWORK_STACK})
@@ -724,7 +763,7 @@
      *
      * @hide
      */
-    @SystemApi
+    @SystemApi(client = MODULE_LIBRARIES)
     @RequiresPermission(anyOf = {
             NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK,
             android.Manifest.permission.NETWORK_STACK})
@@ -785,10 +824,28 @@
     /**
      * Registers to receive notifications about data usage on specified networks.
      *
-     * @see #registerUsageCallback(int, String, long, UsageCallback, Handler)
+     * <p>The callbacks will continue to be called as long as the process is live or
+     * {@link #unregisterUsageCallback} is called.
+     *
+     * @param networkType Type of network to monitor. Either
+    {@link ConnectivityManager#TYPE_MOBILE} or {@link ConnectivityManager#TYPE_WIFI}.
+     * @param subscriberId If applicable, the subscriber id of the network interface.
+     *                     <p>Starting with API level 29, the {@code subscriberId} is guarded by
+     *                     additional restrictions. Calling apps that do not meet the new
+     *                     requirements to access the {@code subscriberId} can provide a {@code
+     *                     null} value when registering for the mobile network type to receive
+     *                     notifications for all mobile networks. For additional details see {@link
+     *                     TelephonyManager#getSubscriberId()}.
+     *                     <p>Starting with API level 31, calling apps can provide a
+     *                     {@code subscriberId} with wifi network type to receive usage for
+     *                     wifi networks which is under the given subscription if applicable.
+     *                     Otherwise, pass {@code null} when querying all wifi networks.
+     * @param thresholdBytes Threshold in bytes to be notified on.
+     * @param callback The {@link UsageCallback} that the system will call when data usage
+     *            has exceeded the specified threshold.
      */
-    public void registerUsageCallback(int networkType, String subscriberId, long thresholdBytes,
-            UsageCallback callback) {
+    public void registerUsageCallback(int networkType, @Nullable String subscriberId,
+            long thresholdBytes, @NonNull UsageCallback callback) {
         registerUsageCallback(networkType, subscriberId, thresholdBytes, callback,
                 null /* handler */);
     }
@@ -818,8 +875,8 @@
      * @param handler to dispatch callback events through, otherwise if {@code null} it uses
      *            the calling thread.
      */
-    public void registerUsageCallback(int networkType, String subscriberId, long thresholdBytes,
-            UsageCallback callback, @Nullable Handler handler) {
+    public void registerUsageCallback(int networkType, @Nullable String subscriberId,
+            long thresholdBytes, @NonNull UsageCallback callback, @Nullable Handler handler) {
         NetworkTemplate template = createTemplate(networkType, subscriberId);
         if (DBG) {
             Log.d(TAG, "registerUsageCallback called with: {"
@@ -839,7 +896,7 @@
      *
      * @param callback The {@link UsageCallback} used when registering.
      */
-    public void unregisterUsageCallback(UsageCallback callback) {
+    public void unregisterUsageCallback(@NonNull UsageCallback callback) {
         if (callback == null || callback.request == null
                 || callback.request.requestId == DataUsageRequest.REQUEST_ID_UNSET) {
             throw new IllegalArgumentException("Invalid UsageCallback");
@@ -880,7 +937,7 @@
         /**
          * Called when data usage has reached the given threshold.
          */
-        public abstract void onThresholdReached(int networkType, String subscriberId);
+        public abstract void onThresholdReached(int networkType, @Nullable String subscriberId);
 
         /**
          * @hide used for internal bookkeeping
@@ -924,7 +981,7 @@
     @RequiresPermission(anyOf = {
             android.Manifest.permission.NETWORK_STATS_PROVIDER,
             NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK})
-    @NonNull public void registerNetworkStatsProvider(
+    public void registerNetworkStatsProvider(
             @NonNull String tag,
             @NonNull NetworkStatsProvider provider) {
         try {
@@ -950,7 +1007,7 @@
     @RequiresPermission(anyOf = {
             android.Manifest.permission.NETWORK_STATS_PROVIDER,
             NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK})
-    @NonNull public void unregisterNetworkStatsProvider(@NonNull NetworkStatsProvider provider) {
+    public void unregisterNetworkStatsProvider(@NonNull NetworkStatsProvider provider) {
         try {
             provider.getProviderCallbackBinderOrThrow().unregister();
         } catch (RemoteException e) {
@@ -958,7 +1015,7 @@
         }
     }
 
-    private static NetworkTemplate createTemplate(int networkType, String subscriberId) {
+    private static NetworkTemplate createTemplate(int networkType, @Nullable String subscriberId) {
         final NetworkTemplate template;
         switch (networkType) {
             case ConnectivityManager.TYPE_MOBILE:
diff --git a/framework-t/src/android/net/DataUsageRequest.java b/framework-t/src/android/net/DataUsageRequest.java
index b06d515..f0ff465 100644
--- a/framework-t/src/android/net/DataUsageRequest.java
+++ b/framework-t/src/android/net/DataUsageRequest.java
@@ -75,7 +75,7 @@
                 @Override
                 public DataUsageRequest createFromParcel(Parcel in) {
                     int requestId = in.readInt();
-                    NetworkTemplate template = in.readParcelable(null);
+                    NetworkTemplate template = in.readParcelable(null, android.net.NetworkTemplate.class);
                     long thresholdInBytes = in.readLong();
                     DataUsageRequest result = new DataUsageRequest(requestId, template,
                             thresholdInBytes);
diff --git a/framework-t/src/android/net/EthernetManager.java b/framework-t/src/android/net/EthernetManager.java
index 4f61dbf..e02ea89 100644
--- a/framework-t/src/android/net/EthernetManager.java
+++ b/framework-t/src/android/net/EthernetManager.java
@@ -39,8 +39,10 @@
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
 import java.util.ArrayList;
+import java.util.List;
 import java.util.Objects;
 import java.util.concurrent.Executor;
+import java.util.function.IntConsumer;
 
 /**
  * A class that manages and configures Ethernet interfaces.
@@ -53,15 +55,31 @@
     private static final String TAG = "EthernetManager";
 
     private final IEthernetManager mService;
-    @GuardedBy("mListeners")
-    private final ArrayList<ListenerInfo> mListeners = new ArrayList<>();
+    @GuardedBy("mListenerLock")
+    private final ArrayList<ListenerInfo<InterfaceStateListener>> mIfaceListeners =
+            new ArrayList<>();
+    @GuardedBy("mListenerLock")
+    private final ArrayList<ListenerInfo<IntConsumer>> mEthernetStateListeners =
+            new ArrayList<>();
+    final Object mListenerLock = new Object();
     private final IEthernetServiceListener.Stub mServiceListener =
             new IEthernetServiceListener.Stub() {
                 @Override
+                public void onEthernetStateChanged(int state) {
+                    synchronized (mListenerLock) {
+                        for (ListenerInfo<IntConsumer> li : mEthernetStateListeners) {
+                            li.executor.execute(() -> {
+                                li.listener.accept(state);
+                            });
+                        }
+                    }
+                }
+
+                @Override
                 public void onInterfaceStateChanged(String iface, int state, int role,
                         IpConfiguration configuration) {
-                    synchronized (mListeners) {
-                        for (ListenerInfo li : mListeners) {
+                    synchronized (mListenerLock) {
+                        for (ListenerInfo<InterfaceStateListener> li : mIfaceListeners) {
                             li.executor.execute(() ->
                                     li.listener.onInterfaceStateChanged(iface, state, role,
                                             configuration));
@@ -70,13 +88,29 @@
                 }
             };
 
-    private static class ListenerInfo {
+    /**
+     * Indicates that Ethernet is disabled.
+     *
+     * @hide
+     */
+    @SystemApi(client = MODULE_LIBRARIES)
+    public static final int ETHERNET_STATE_DISABLED = 0;
+
+    /**
+     * Indicates that Ethernet is enabled.
+     *
+     * @hide
+     */
+    @SystemApi(client = MODULE_LIBRARIES)
+    public static final int ETHERNET_STATE_ENABLED  = 1;
+
+    private static class ListenerInfo<T> {
         @NonNull
         public final Executor executor;
         @NonNull
-        public final InterfaceStateListener listener;
+        public final T listener;
 
-        private ListenerInfo(@NonNull Executor executor, @NonNull InterfaceStateListener listener) {
+        private ListenerInfo(@NonNull Executor executor, @NonNull T listener) {
             this.executor = executor;
             this.listener = listener;
         }
@@ -289,18 +323,24 @@
         if (listener == null || executor == null) {
             throw new NullPointerException("listener and executor must not be null");
         }
-        synchronized (mListeners) {
-            mListeners.add(new ListenerInfo(executor, listener));
-            if (mListeners.size() == 1) {
-                try {
-                    mService.addListener(mServiceListener);
-                } catch (RemoteException e) {
-                    throw e.rethrowFromSystemServer();
-                }
-            }
+        synchronized (mListenerLock) {
+            maybeAddServiceListener();
+            mIfaceListeners.add(new ListenerInfo<InterfaceStateListener>(executor, listener));
         }
     }
 
+    @GuardedBy("mListenerLock")
+    private void maybeAddServiceListener() {
+        if (!mIfaceListeners.isEmpty() || !mEthernetStateListeners.isEmpty()) return;
+
+        try {
+            mService.addListener(mServiceListener);
+        } catch (RemoteException e) {
+            throw e.rethrowFromSystemServer();
+        }
+
+    }
+
     /**
      * Returns an array of available Ethernet interface names.
      * @hide
@@ -323,15 +363,20 @@
     @SystemApi(client = MODULE_LIBRARIES)
     public void removeInterfaceStateListener(@NonNull InterfaceStateListener listener) {
         Objects.requireNonNull(listener);
-        synchronized (mListeners) {
-            mListeners.removeIf(l -> l.listener == listener);
-            if (mListeners.isEmpty()) {
-                try {
-                    mService.removeListener(mServiceListener);
-                } catch (RemoteException e) {
-                    throw e.rethrowFromSystemServer();
-                }
-            }
+        synchronized (mListenerLock) {
+            mIfaceListeners.removeIf(l -> l.listener == listener);
+            maybeRemoveServiceListener();
+        }
+    }
+
+    @GuardedBy("mListenerLock")
+    private void maybeRemoveServiceListener() {
+        if (!mIfaceListeners.isEmpty() || !mEthernetStateListeners.isEmpty()) return;
+
+        try {
+            mService.removeListener(mServiceListener);
+        } catch (RemoteException e) {
+            throw e.rethrowFromSystemServer();
         }
     }
 
@@ -535,14 +580,13 @@
     }
 
     /**
-     * Set an ethernet network's link state up.
+     * Enable a network interface.
      *
-     * When the link is successfully turned up, the callback will be called with the network
-     * interface was torn down, if any. If any error or unexpected condition happens while the
-     * system tries to turn the interface down, the callback will be called with an appropriate
-     * exception. The callback is guaranteed to be called exactly once for each call to this method.
+     * Enables a previously disabled network interface.
+     * This function accepts an {@link OutcomeReceiver} that is called once the operation has
+     * finished execution.
      *
-     * @param iface the name of the interface to act upon.
+     * @param iface the name of the interface to enable.
      * @param executor an {@link Executor} to execute the callback on. Optional if callback is null.
      * @param callback an optional {@link OutcomeReceiver} to listen for completion of the
      *                 operation. On success, {@link OutcomeReceiver#onResult} is called with the
@@ -550,7 +594,6 @@
      *                 information about the error.
      * @throws SecurityException if the process doesn't hold
      *                          {@link android.Manifest.permission.MANAGE_ETHERNET_NETWORKS}.
-     * @throws UnsupportedOperationException if called on a non-automotive device.
      * @hide
      */
     @SystemApi
@@ -559,7 +602,7 @@
             android.Manifest.permission.NETWORK_STACK,
             android.Manifest.permission.MANAGE_ETHERNET_NETWORKS})
     @RequiresFeature(PackageManager.FEATURE_AUTOMOTIVE)
-    public void connectNetwork(
+    public void enableInterface(
             @NonNull String iface,
             @Nullable @CallbackExecutor Executor executor,
             @Nullable OutcomeReceiver<String, EthernetNetworkManagementException> callback) {
@@ -574,14 +617,14 @@
     }
 
     /**
-     * Set an ethernet network's link state down.
+     * Disable a network interface.
      *
-     * When the link is successfully turned down, the callback will be called with the network
-     * interface was torn down, if any. If any error or unexpected condition happens while the
-     * system tries to turn the interface down, the callback will be called with an appropriate
-     * exception. The callback is guaranteed to be called exactly once for each call to this method.
+     * Disables the use of a network interface to fulfill network requests. If the interface
+     * currently serves a request, the network will be torn down.
+     * This function accepts an {@link OutcomeReceiver} that is called once the operation has
+     * finished execution.
      *
-     * @param iface the name of the interface to act upon.
+     * @param iface the name of the interface to disable.
      * @param executor an {@link Executor} to execute the callback on. Optional if callback is null.
      * @param callback an optional {@link OutcomeReceiver} to listen for completion of the
      *                 operation. On success, {@link OutcomeReceiver#onResult} is called with the
@@ -589,7 +632,6 @@
      *                 information about the error.
      * @throws SecurityException if the process doesn't hold
      *                          {@link android.Manifest.permission.MANAGE_ETHERNET_NETWORKS}.
-     * @throws UnsupportedOperationException if called on a non-automotive device.
      * @hide
      */
     @SystemApi
@@ -598,7 +640,7 @@
             android.Manifest.permission.NETWORK_STACK,
             android.Manifest.permission.MANAGE_ETHERNET_NETWORKS})
     @RequiresFeature(PackageManager.FEATURE_AUTOMOTIVE)
-    public void disconnectNetwork(
+    public void disableInterface(
             @NonNull String iface,
             @Nullable @CallbackExecutor Executor executor,
             @Nullable OutcomeReceiver<String, EthernetNetworkManagementException> callback) {
@@ -611,4 +653,77 @@
             throw e.rethrowFromSystemServer();
         }
     }
+
+    /**
+     * Change ethernet setting.
+     *
+     * @param enabled enable or disable ethernet settings.
+     *
+     * @hide
+     */
+    @RequiresPermission(anyOf = {
+            NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK,
+            android.Manifest.permission.NETWORK_STACK,
+            android.Manifest.permission.NETWORK_SETTINGS})
+    @SystemApi(client = MODULE_LIBRARIES)
+    public void setEthernetEnabled(boolean enabled) {
+        try {
+            mService.setEthernetEnabled(enabled);
+        } catch (RemoteException e) {
+            throw e.rethrowFromSystemServer();
+        }
+    }
+
+    /**
+     * Listen to changes in the state of ethernet.
+     *
+     * @param executor to run callbacks on.
+     * @param listener to listen ethernet state changed.
+     *
+     * @hide
+     */
+    @RequiresPermission(android.Manifest.permission.ACCESS_NETWORK_STATE)
+    @SystemApi(client = MODULE_LIBRARIES)
+    public void addEthernetStateListener(@NonNull Executor executor,
+            @NonNull IntConsumer listener) {
+        Objects.requireNonNull(executor);
+        Objects.requireNonNull(listener);
+        synchronized (mListenerLock) {
+            maybeAddServiceListener();
+            mEthernetStateListeners.add(new ListenerInfo<IntConsumer>(executor, listener));
+        }
+    }
+
+    /**
+     * Removes a listener.
+     *
+     * @param listener to listen ethernet state changed.
+     *
+     * @hide
+     */
+    @RequiresPermission(android.Manifest.permission.ACCESS_NETWORK_STATE)
+    @SystemApi(client = MODULE_LIBRARIES)
+    public void removeEthernetStateListener(@NonNull IntConsumer listener) {
+        Objects.requireNonNull(listener);
+        synchronized (mListenerLock) {
+            mEthernetStateListeners.removeIf(l -> l.listener == listener);
+            maybeRemoveServiceListener();
+        }
+    }
+
+    /**
+     * Returns an array of existing Ethernet interface names regardless whether the interface
+     * is available or not currently.
+     * @hide
+     */
+    @RequiresPermission(android.Manifest.permission.ACCESS_NETWORK_STATE)
+    @SystemApi(client = MODULE_LIBRARIES)
+    @NonNull
+    public List<String> getInterfaceList() {
+        try {
+            return mService.getInterfaceList();
+        } catch (RemoteException e) {
+            throw e.rethrowAsRuntimeException();
+        }
+    }
 }
diff --git a/framework-t/src/android/net/IEthernetManager.aidl b/framework-t/src/android/net/IEthernetManager.aidl
index 95ae907..42e4c1a 100644
--- a/framework-t/src/android/net/IEthernetManager.aidl
+++ b/framework-t/src/android/net/IEthernetManager.aidl
@@ -23,6 +23,8 @@
 import android.net.INetworkInterfaceOutcomeReceiver;
 import android.net.ITetheredInterfaceCallback;
 
+import java.util.List;
+
 /**
  * Interface that answers queries about, and allows changing
  * ethernet configuration.
@@ -43,4 +45,6 @@
         in INetworkInterfaceOutcomeReceiver listener);
     void connectNetwork(String iface, in INetworkInterfaceOutcomeReceiver listener);
     void disconnectNetwork(String iface, in INetworkInterfaceOutcomeReceiver listener);
+    void setEthernetEnabled(boolean enabled);
+    List<String> getInterfaceList();
 }
diff --git a/framework-t/src/android/net/IEthernetServiceListener.aidl b/framework-t/src/android/net/IEthernetServiceListener.aidl
index 6d2ba03..751605b 100644
--- a/framework-t/src/android/net/IEthernetServiceListener.aidl
+++ b/framework-t/src/android/net/IEthernetServiceListener.aidl
@@ -21,6 +21,7 @@
 /** @hide */
 oneway interface IEthernetServiceListener
 {
+    void onEthernetStateChanged(int state);
     void onInterfaceStateChanged(String iface, int state, int role,
             in IpConfiguration configuration);
 }
diff --git a/framework-t/src/android/net/IpSecConfig.java b/framework-t/src/android/net/IpSecConfig.java
index 575c5ed..03bb187 100644
--- a/framework-t/src/android/net/IpSecConfig.java
+++ b/framework-t/src/android/net/IpSecConfig.java
@@ -267,14 +267,14 @@
         mMode = in.readInt();
         mSourceAddress = in.readString();
         mDestinationAddress = in.readString();
-        mNetwork = (Network) in.readParcelable(Network.class.getClassLoader());
+        mNetwork = (Network) in.readParcelable(Network.class.getClassLoader(), android.net.Network.class);
         mSpiResourceId = in.readInt();
         mEncryption =
-                (IpSecAlgorithm) in.readParcelable(IpSecAlgorithm.class.getClassLoader());
+                (IpSecAlgorithm) in.readParcelable(IpSecAlgorithm.class.getClassLoader(), android.net.IpSecAlgorithm.class);
         mAuthentication =
-                (IpSecAlgorithm) in.readParcelable(IpSecAlgorithm.class.getClassLoader());
+                (IpSecAlgorithm) in.readParcelable(IpSecAlgorithm.class.getClassLoader(), android.net.IpSecAlgorithm.class);
         mAuthenticatedEncryption =
-                (IpSecAlgorithm) in.readParcelable(IpSecAlgorithm.class.getClassLoader());
+                (IpSecAlgorithm) in.readParcelable(IpSecAlgorithm.class.getClassLoader(), android.net.IpSecAlgorithm.class);
         mEncapType = in.readInt();
         mEncapSocketResourceId = in.readInt();
         mEncapRemotePort = in.readInt();
diff --git a/framework-t/src/android/net/IpSecUdpEncapResponse.java b/framework-t/src/android/net/IpSecUdpEncapResponse.java
index 732cf19..390af82 100644
--- a/framework-t/src/android/net/IpSecUdpEncapResponse.java
+++ b/framework-t/src/android/net/IpSecUdpEncapResponse.java
@@ -81,7 +81,7 @@
         status = in.readInt();
         resourceId = in.readInt();
         port = in.readInt();
-        fileDescriptor = in.readParcelable(ParcelFileDescriptor.class.getClassLoader());
+        fileDescriptor = in.readParcelable(ParcelFileDescriptor.class.getClassLoader(), android.os.ParcelFileDescriptor.class);
     }
 
     @android.annotation.NonNull
diff --git a/framework-t/src/android/net/NetworkStateSnapshot.java b/framework-t/src/android/net/NetworkStateSnapshot.java
index d3f785a..c018e91 100644
--- a/framework-t/src/android/net/NetworkStateSnapshot.java
+++ b/framework-t/src/android/net/NetworkStateSnapshot.java
@@ -75,9 +75,9 @@
 
     /** @hide */
     public NetworkStateSnapshot(@NonNull Parcel in) {
-        mNetwork = in.readParcelable(null);
-        mNetworkCapabilities = in.readParcelable(null);
-        mLinkProperties = in.readParcelable(null);
+        mNetwork = in.readParcelable(null, android.net.Network.class);
+        mNetworkCapabilities = in.readParcelable(null, android.net.NetworkCapabilities.class);
+        mLinkProperties = in.readParcelable(null, android.net.LinkProperties.class);
         mSubscriberId = in.readString();
         mLegacyType = in.readInt();
     }
diff --git a/framework-t/src/android/net/NetworkStats.java b/framework-t/src/android/net/NetworkStats.java
index 06f2a62..bcfeab9 100644
--- a/framework-t/src/android/net/NetworkStats.java
+++ b/framework-t/src/android/net/NetworkStats.java
@@ -16,6 +16,8 @@
 
 package android.net;
 
+import static android.annotation.SystemApi.Client.MODULE_LIBRARIES;
+
 import static com.android.net.module.util.NetworkStatsUtils.multiplySafeByRational;
 
 import android.annotation.IntDef;
@@ -124,7 +126,6 @@
     public @Nullable static final String[] INTERFACES_ALL = null;
 
     /** {@link #tag} value for total data across all tags. */
-    // TODO: Rename TAG_NONE to TAG_ALL.
     public static final int TAG_NONE = 0;
 
     /** {@link #metered} value to account for all metered states. */
@@ -390,77 +391,102 @@
 
         /**
          * @return the uid of this entry.
+         * @hide
          */
+        @SystemApi(client = MODULE_LIBRARIES)
         public int getUid() {
             return uid;
         }
 
         /**
          * @return the set state of this entry.
+         * @hide
          */
+        @SystemApi(client = MODULE_LIBRARIES)
         @State public int getSet() {
             return set;
         }
 
         /**
          * @return the tag value of this entry.
+         * @hide
          */
+        @SystemApi(client = MODULE_LIBRARIES)
         public int getTag() {
             return tag;
         }
 
         /**
          * @return the metered state.
+         * @hide
          */
-        @Meteredness public int getMetered() {
+        @Meteredness
+        @SystemApi(client = MODULE_LIBRARIES)
+        public int getMetered() {
             return metered;
         }
 
         /**
          * @return the roaming state.
+         * @hide
          */
-        @Roaming public int getRoaming() {
+        @Roaming
+        @SystemApi(client = MODULE_LIBRARIES)
+        public int getRoaming() {
             return roaming;
         }
 
         /**
          * @return the default network state.
+         * @hide
          */
-        @DefaultNetwork public int getDefaultNetwork() {
+        @DefaultNetwork
+        @SystemApi(client = MODULE_LIBRARIES)
+        public int getDefaultNetwork() {
             return defaultNetwork;
         }
 
         /**
          * @return the number of received bytes.
+         * @hide
          */
+        @SystemApi(client = MODULE_LIBRARIES)
         public long getRxBytes() {
             return rxBytes;
         }
 
         /**
          * @return the number of received packets.
+         * @hide
          */
+        @SystemApi(client = MODULE_LIBRARIES)
         public long getRxPackets() {
             return rxPackets;
         }
 
         /**
          * @return the number of transmitted bytes.
+         * @hide
          */
+        @SystemApi(client = MODULE_LIBRARIES)
         public long getTxBytes() {
             return txBytes;
         }
 
         /**
          * @return the number of transmitted packets.
+         * @hide
          */
+        @SystemApi(client = MODULE_LIBRARIES)
         public long getTxPackets() {
             return txPackets;
         }
 
         /**
          * @return the count of network operations performed for this entry.
+         * @hide
          */
+        @SystemApi(client = MODULE_LIBRARIES)
         public long getOperations() {
             return operations;
         }
@@ -682,7 +708,7 @@
      * The remove() method is not implemented and will throw UnsupportedOperationException.
      * @hide
      */
-    @SystemApi
+    @SystemApi(client = MODULE_LIBRARIES)
     @NonNull public Iterator<Entry> iterator() {
         return new Iterator<Entry>() {
             int mIndex = 0;
diff --git a/framework-t/src/android/net/TrafficStats.java b/framework-t/src/android/net/TrafficStats.java
index bc836d8..dc4ac55 100644
--- a/framework-t/src/android/net/TrafficStats.java
+++ b/framework-t/src/android/net/TrafficStats.java
@@ -205,7 +205,7 @@
      *                server context.
      * @hide
      */
-    @SystemApi(client = SystemApi.Client.MODULE_LIBRARIES)
+    @SystemApi(client = MODULE_LIBRARIES)
     @SuppressLint("VisiblySynchronized")
     public static synchronized void init(@NonNull final Context context) {
         if (sStatsService != null) {
@@ -376,7 +376,7 @@
      *
      * @hide
      */
-    @SystemApi
+    @SystemApi(client = MODULE_LIBRARIES)
     public static void setThreadStatsTagDownload() {
         setThreadStatsTag(TAG_SYSTEM_DOWNLOAD);
     }
@@ -468,7 +468,7 @@
      *
      * @see #setThreadStatsTag(int)
      */
-    public static void tagSocket(Socket socket) throws SocketException {
+    public static void tagSocket(@NonNull Socket socket) throws SocketException {
         SocketTagger.get().tag(socket);
     }
 
@@ -483,7 +483,7 @@
      * calling {@code untagSocket()} before sending the socket to another
      * process.
      */
-    public static void untagSocket(Socket socket) throws SocketException {
+    public static void untagSocket(@NonNull Socket socket) throws SocketException {
         SocketTagger.get().untag(socket);
     }
 
@@ -496,14 +496,14 @@
      *
      * @see #setThreadStatsTag(int)
      */
-    public static void tagDatagramSocket(DatagramSocket socket) throws SocketException {
+    public static void tagDatagramSocket(@NonNull DatagramSocket socket) throws SocketException {
         SocketTagger.get().tag(socket);
     }
 
     /**
      * Remove any statistics parameters from the given {@link DatagramSocket}.
      */
-    public static void untagDatagramSocket(DatagramSocket socket) throws SocketException {
+    public static void untagDatagramSocket(@NonNull DatagramSocket socket) throws SocketException {
         SocketTagger.get().untag(socket);
     }
 
@@ -516,7 +516,7 @@
      *
      * @see #setThreadStatsTag(int)
      */
-    public static void tagFileDescriptor(FileDescriptor fd) throws IOException {
+    public static void tagFileDescriptor(@NonNull FileDescriptor fd) throws IOException {
         SocketTagger.get().tag(fd);
     }
 
@@ -524,7 +524,7 @@
      * Remove any statistics parameters from the given {@link FileDescriptor}
      * socket.
      */
-    public static void untagFileDescriptor(FileDescriptor fd) throws IOException {
+    public static void untagFileDescriptor(@NonNull FileDescriptor fd) throws IOException {
         SocketTagger.get().untag(fd);
     }
 
diff --git a/framework-t/src/android/net/UnderlyingNetworkInfo.java b/framework-t/src/android/net/UnderlyingNetworkInfo.java
index 33f9375..7ab53b1 100644
--- a/framework-t/src/android/net/UnderlyingNetworkInfo.java
+++ b/framework-t/src/android/net/UnderlyingNetworkInfo.java
@@ -60,7 +60,7 @@
         mOwnerUid = in.readInt();
         mIface = in.readString();
         List<String> underlyingIfaces = new ArrayList<>();
-        in.readList(underlyingIfaces, null /*classLoader*/);
+        in.readList(underlyingIfaces, null /*classLoader*/, java.lang.String.class);
         mUnderlyingIfaces = Collections.unmodifiableList(underlyingIfaces);
     }