diff --git a/core/java/android/net/ConnectivityManager.java b/core/java/android/net/ConnectivityManager.java
index 8742ecb..d107261 100644
--- a/core/java/android/net/ConnectivityManager.java
+++ b/core/java/android/net/ConnectivityManager.java
@@ -19,6 +19,7 @@
 import static android.net.NetworkRequest.Type.LISTEN;
 import static android.net.NetworkRequest.Type.REQUEST;
 import static android.net.NetworkRequest.Type.TRACK_DEFAULT;
+import static android.net.QosCallback.QosCallbackRegistrationException;
 
 import android.annotation.CallbackExecutor;
 import android.annotation.IntDef;
@@ -29,7 +30,6 @@
 import android.annotation.SdkConstant.SdkConstantType;
 import android.annotation.SystemApi;
 import android.annotation.SystemService;
-import android.annotation.TestApi;
 import android.app.PendingIntent;
 import android.compat.annotation.UnsupportedAppUsage;
 import android.content.Context;
@@ -72,7 +72,6 @@
 
 import libcore.net.event.NetworkEventDispatcher;
 
-import java.io.FileDescriptor;
 import java.io.IOException;
 import java.io.UncheckedIOException;
 import java.lang.annotation.Retention;
@@ -1958,6 +1957,12 @@
         return k;
     }
 
+    // Construct an invalid fd.
+    private ParcelFileDescriptor createInvalidFd() {
+        final int invalidFd = -1;
+        return ParcelFileDescriptor.adoptFd(invalidFd);
+    }
+
     /**
      * Request that keepalives be started on a IPsec NAT-T socket.
      *
@@ -1988,7 +1993,7 @@
         } catch (IOException ignored) {
             // Construct an invalid fd, so that if the user later calls start(), it will fail with
             // ERROR_INVALID_SOCKET.
-            dup = new ParcelFileDescriptor(new FileDescriptor());
+            dup = createInvalidFd();
         }
         return new NattSocketKeepalive(mService, network, dup, socket.getResourceId(), source,
                 destination, executor, callback);
@@ -2030,7 +2035,7 @@
         } catch (IOException ignored) {
             // Construct an invalid fd, so that if the user later calls start(), it will fail with
             // ERROR_INVALID_SOCKET.
-            dup = new ParcelFileDescriptor(new FileDescriptor());
+            dup = createInvalidFd();
         }
         return new NattSocketKeepalive(mService, network, dup,
                 INVALID_RESOURCE_ID /* Unused */, source, destination, executor, callback);
@@ -2067,7 +2072,7 @@
         } catch (UncheckedIOException ignored) {
             // Construct an invalid fd, so that if the user later calls start(), it will fail with
             // ERROR_INVALID_SOCKET.
-            dup = new ParcelFileDescriptor(new FileDescriptor());
+            dup = createInvalidFd();
         }
         return new TcpSocketKeepalive(mService, network, dup, executor, callback);
     }
@@ -4818,6 +4823,8 @@
     /**
      * Simulates a Data Stall for the specified Network.
      *
+     * <p>This method should only be used for tests.
+     *
      * <p>The caller must be the owner of the specified Network.
      *
      * @param detectionMethod The detection method used to identify the Data Stall.
@@ -4827,7 +4834,7 @@
      * @throws SecurityException if the caller is not the owner of the given network.
      * @hide
      */
-    @TestApi
+    @SystemApi(client = SystemApi.Client.MODULE_LIBRARIES)
     @RequiresPermission(anyOf = {android.Manifest.permission.MANAGE_TEST_NETWORKS,
             android.Manifest.permission.NETWORK_STACK})
     public void simulateDataStall(int detectionMethod, long timestampMillis,
@@ -4843,4 +4850,118 @@
         Log.d(TAG, "setOemNetworkPreference called with preference: "
                 + preference.toString());
     }
+
+    @NonNull
+    private final List<QosCallbackConnection> mQosCallbackConnections = new ArrayList<>();
+
+    /**
+     * Registers a {@link QosSocketInfo} with an associated {@link QosCallback}.  The callback will
+     * receive available QoS events related to the {@link Network} and local ip + port
+     * specified within socketInfo.
+     * <p/>
+     * The same {@link QosCallback} must be unregistered before being registered a second time,
+     * otherwise {@link QosCallbackRegistrationException} is thrown.
+     * <p/>
+     * This API does not, in itself, require any permission if called with a network that is not
+     * restricted. However, the underlying implementation currently only supports the IMS network,
+     * which is always restricted. That means non-preinstalled callers can't possibly find this API
+     * useful, because they'd never be called back on networks that they would have access to.
+     *
+     * @throws SecurityException if {@link QosSocketInfo#getNetwork()} is restricted and the app is
+     * missing CONNECTIVITY_USE_RESTRICTED_NETWORKS permission.
+     * @throws QosCallback.QosCallbackRegistrationException if qosCallback is already registered.
+     * @throws RuntimeException if the app already has too many callbacks registered.
+     *
+     * Exceptions after the time of registration is passed through
+     * {@link QosCallback#onError(QosCallbackException)}.  see: {@link QosCallbackException}.
+     *
+     * @param socketInfo the socket information used to match QoS events
+     * @param callback receives qos events that satisfy socketInfo
+     * @param executor The executor on which the callback will be invoked. The provided
+     *                 {@link Executor} must run callback sequentially, otherwise the order of
+     *                 callbacks cannot be guaranteed.
+     *
+     * @hide
+     */
+    @SystemApi
+    public void registerQosCallback(@NonNull final QosSocketInfo socketInfo,
+            @NonNull final QosCallback callback,
+            @CallbackExecutor @NonNull final Executor executor) {
+        Objects.requireNonNull(socketInfo, "socketInfo must be non-null");
+        Objects.requireNonNull(callback, "callback must be non-null");
+        Objects.requireNonNull(executor, "executor must be non-null");
+
+        try {
+            synchronized (mQosCallbackConnections) {
+                if (getQosCallbackConnection(callback) == null) {
+                    final QosCallbackConnection connection =
+                            new QosCallbackConnection(this, callback, executor);
+                    mQosCallbackConnections.add(connection);
+                    mService.registerQosSocketCallback(socketInfo, connection);
+                } else {
+                    Log.e(TAG, "registerQosCallback: Callback already registered");
+                    throw new QosCallbackRegistrationException();
+                }
+            }
+        } catch (final RemoteException e) {
+            Log.e(TAG, "registerQosCallback: Error while registering ", e);
+
+            // The same unregister method method is called for consistency even though nothing
+            // will be sent to the ConnectivityService since the callback was never successfully
+            // registered.
+            unregisterQosCallback(callback);
+            e.rethrowFromSystemServer();
+        } catch (final ServiceSpecificException e) {
+            Log.e(TAG, "registerQosCallback: Error while registering ", e);
+            unregisterQosCallback(callback);
+            throw convertServiceException(e);
+        }
+    }
+
+    /**
+     * Unregisters the given {@link QosCallback}.  The {@link QosCallback} will no longer receive
+     * events once unregistered and can be registered a second time.
+     * <p/>
+     * If the {@link QosCallback} does not have an active registration, it is a no-op.
+     *
+     * @param callback the callback being unregistered
+     *
+     * @hide
+     */
+    @SystemApi
+    public void unregisterQosCallback(@NonNull final QosCallback callback) {
+        Objects.requireNonNull(callback, "The callback must be non-null");
+        try {
+            synchronized (mQosCallbackConnections) {
+                final QosCallbackConnection connection = getQosCallbackConnection(callback);
+                if (connection != null) {
+                    connection.stopReceivingMessages();
+                    mService.unregisterQosCallback(connection);
+                    mQosCallbackConnections.remove(connection);
+                } else {
+                    Log.d(TAG, "unregisterQosCallback: Callback not registered");
+                }
+            }
+        } catch (final RemoteException e) {
+            Log.e(TAG, "unregisterQosCallback: Error while unregistering ", e);
+            e.rethrowFromSystemServer();
+        }
+    }
+
+    /**
+     * Gets the connection related to the callback.
+     *
+     * @param callback the callback to look up
+     * @return the related connection
+     */
+    @Nullable
+    private QosCallbackConnection getQosCallbackConnection(final QosCallback callback) {
+        for (final QosCallbackConnection connection : mQosCallbackConnections) {
+            // Checking by reference here is intentional
+            if (connection.getCallback() == callback) {
+                return connection;
+            }
+        }
+        return null;
+    }
 }
diff --git a/core/java/android/net/IConnectivityManager.aidl b/core/java/android/net/IConnectivityManager.aidl
index 5e925b6..6fecee6 100644
--- a/core/java/android/net/IConnectivityManager.aidl
+++ b/core/java/android/net/IConnectivityManager.aidl
@@ -20,6 +20,8 @@
 import android.net.ConnectionInfo;
 import android.net.ConnectivityDiagnosticsManager;
 import android.net.IConnectivityDiagnosticsCallback;
+import android.net.IQosCallback;
+import android.net.ISocketKeepaliveCallback;
 import android.net.LinkProperties;
 import android.net.Network;
 import android.net.NetworkAgentConfig;
@@ -27,9 +29,9 @@
 import android.net.NetworkInfo;
 import android.net.NetworkRequest;
 import android.net.NetworkState;
-import android.net.ISocketKeepaliveCallback;
 import android.net.ProxyInfo;
 import android.net.UidRange;
+import android.net.QosSocketInfo;
 import android.os.Bundle;
 import android.os.IBinder;
 import android.os.INetworkActivityListener;
@@ -206,11 +208,11 @@
     void startNattKeepalive(in Network network, int intervalSeconds,
             in ISocketKeepaliveCallback cb, String srcAddr, int srcPort, String dstAddr);
 
-    void startNattKeepaliveWithFd(in Network network, in FileDescriptor fd, int resourceId,
+    void startNattKeepaliveWithFd(in Network network, in ParcelFileDescriptor pfd, int resourceId,
             int intervalSeconds, in ISocketKeepaliveCallback cb, String srcAddr,
             String dstAddr);
 
-    void startTcpKeepalive(in Network network, in FileDescriptor fd, int intervalSeconds,
+    void startTcpKeepalive(in Network network, in ParcelFileDescriptor pfd, int intervalSeconds,
             in ISocketKeepaliveCallback cb);
 
     void stopKeepalive(in Network network, int slot);
@@ -239,4 +241,7 @@
     void unregisterNetworkActivityListener(in INetworkActivityListener l);
 
     boolean isDefaultNetworkActive();
+
+    void registerQosSocketCallback(in QosSocketInfo socketInfo, in IQosCallback callback);
+    void unregisterQosCallback(in IQosCallback callback);
 }
diff --git a/core/java/android/net/NattSocketKeepalive.java b/core/java/android/net/NattSocketKeepalive.java
index b0ce0c7..a15d165 100644
--- a/core/java/android/net/NattSocketKeepalive.java
+++ b/core/java/android/net/NattSocketKeepalive.java
@@ -51,7 +51,7 @@
     void startImpl(int intervalSec) {
         mExecutor.execute(() -> {
             try {
-                mService.startNattKeepaliveWithFd(mNetwork, mPfd.getFileDescriptor(), mResourceId,
+                mService.startNattKeepaliveWithFd(mNetwork, mPfd, mResourceId,
                         intervalSec, mCallback,
                         mSource.getHostAddress(), mDestination.getHostAddress());
             } catch (RemoteException e) {
diff --git a/core/java/android/net/NetworkAgent.java b/core/java/android/net/NetworkAgent.java
index 4f46736..d22d82d 100644
--- a/core/java/android/net/NetworkAgent.java
+++ b/core/java/android/net/NetworkAgent.java
@@ -30,6 +30,7 @@
 import android.os.Looper;
 import android.os.Message;
 import android.os.RemoteException;
+import android.telephony.data.EpsBearerQosSessionAttributes;
 import android.util.Log;
 
 import com.android.connectivity.aidl.INetworkAgent;
@@ -228,12 +229,6 @@
     public static final String REDIRECT_URL_KEY = "redirect URL";
 
     /**
-     * Bundle key for the underlying networks in {@code EVENT_UNDERLYING_NETWORKS_CHANGED}.
-     * @hide
-     */
-    public static final String UNDERLYING_NETWORKS_KEY = "underlyingNetworks";
-
-     /**
      * Sent by the NetworkAgent to ConnectivityService to indicate this network was
      * explicitly selected.  This should be sent before the NetworkInfo is marked
      * CONNECTED so it can be given special treatment at that time.
@@ -347,6 +342,24 @@
      */
     private static final int EVENT_AGENT_DISCONNECTED = BASE + 19;
 
+    /**
+     * Sent by QosCallbackTracker to {@link NetworkAgent} to register a new filter with
+     * callback.
+     *
+     * arg1 = QoS agent callback ID
+     * obj = {@link QosFilter}
+     * @hide
+     */
+    public static final int CMD_REGISTER_QOS_CALLBACK = BASE + 20;
+
+    /**
+     * Sent by QosCallbackTracker to {@link NetworkAgent} to unregister a callback.
+     *
+     * arg1 = QoS agent callback ID
+     * @hide
+     */
+    public static final int CMD_UNREGISTER_QOS_CALLBACK = BASE + 21;
+
     private static NetworkInfo getLegacyNetworkInfo(final NetworkAgentConfig config) {
         // The subtype can be changed with (TODO) setLegacySubtype, but it starts
         // with 0 (TelephonyManager.NETWORK_TYPE_UNKNOWN) and an empty description.
@@ -526,6 +539,17 @@
                     onRemoveKeepalivePacketFilter(msg.arg1 /* slot */);
                     break;
                 }
+                case CMD_REGISTER_QOS_CALLBACK: {
+                    onQosCallbackRegistered(
+                            msg.arg1 /* QoS callback id */,
+                            (QosFilter) msg.obj /* QoS filter */);
+                    break;
+                }
+                case CMD_UNREGISTER_QOS_CALLBACK: {
+                    onQosCallbackUnregistered(
+                            msg.arg1 /* QoS callback id */);
+                    break;
+                }
             }
         }
     }
@@ -559,6 +583,8 @@
     }
 
     private static class NetworkAgentBinder extends INetworkAgent.Stub {
+        private static final String LOG_TAG = NetworkAgentBinder.class.getSimpleName();
+
         private final Handler mHandler;
 
         private NetworkAgentBinder(Handler handler) {
@@ -645,6 +671,25 @@
             mHandler.sendMessage(mHandler.obtainMessage(CMD_REMOVE_KEEPALIVE_PACKET_FILTER,
                     slot, 0));
         }
+
+        @Override
+        public void onQosFilterCallbackRegistered(final int qosCallbackId,
+                final QosFilterParcelable qosFilterParcelable) {
+            if (qosFilterParcelable.getQosFilter() != null) {
+                mHandler.sendMessage(
+                        mHandler.obtainMessage(CMD_REGISTER_QOS_CALLBACK, qosCallbackId, 0,
+                                qosFilterParcelable.getQosFilter()));
+                return;
+            }
+
+            Log.wtf(LOG_TAG, "onQosFilterCallbackRegistered: qos filter is null.");
+        }
+
+        @Override
+        public void onQosCallbackUnregistered(final int qosCallbackId) {
+            mHandler.sendMessage(mHandler.obtainMessage(
+                    CMD_UNREGISTER_QOS_CALLBACK, qosCallbackId, 0, null));
+        }
     }
 
     /**
@@ -1073,8 +1118,68 @@
     protected void preventAutomaticReconnect() {
     }
 
+    /**
+     * Called when a qos callback is registered with a filter.
+     * @param qosCallbackId the id for the callback registered
+     * @param filter the filter being registered
+     */
+    public void onQosCallbackRegistered(final int qosCallbackId, final @NonNull QosFilter filter) {
+    }
+
+    /**
+     * Called when a qos callback is registered with a filter.
+     * <p/>
+     * Any QoS events that are sent with the same callback id after this method is called
+     * are a no-op.
+     *
+     * @param qosCallbackId the id for the callback being unregistered
+     */
+    public void onQosCallbackUnregistered(final int qosCallbackId) {
+    }
+
+
+    /**
+     * Sends the attributes of Eps Bearer Qos Session back to the Application
+     *
+     * @param qosCallbackId the callback id that the session belongs to
+     * @param sessionId the unique session id across all Eps Bearer Qos Sessions
+     * @param attributes the attributes of the Eps Qos Session
+     */
+    public final void sendQosSessionAvailable(final int qosCallbackId, final int sessionId,
+            @NonNull final EpsBearerQosSessionAttributes attributes) {
+        Objects.requireNonNull(attributes, "The attributes must be non-null");
+        queueOrSendMessage(ra -> ra.sendEpsQosSessionAvailable(qosCallbackId,
+                new QosSession(sessionId, QosSession.TYPE_EPS_BEARER),
+                attributes));
+    }
+
+    /**
+     * Sends event that the Eps Qos Session was lost.
+     *
+     * @param qosCallbackId the callback id that the session belongs to
+     * @param sessionId the unique session id across all Eps Bearer Qos Sessions
+     */
+    public final void sendQosSessionLost(final int qosCallbackId, final int sessionId) {
+        queueOrSendMessage(ra -> ra.sendQosSessionLost(qosCallbackId,
+                new QosSession(sessionId, QosSession.TYPE_EPS_BEARER)));
+    }
+
+    /**
+     * Sends the exception type back to the application.
+     *
+     * The NetworkAgent should not send anymore messages with this id.
+     *
+     * @param qosCallbackId the callback id this exception belongs to
+     * @param exceptionType the type of exception
+     */
+    public final void sendQosCallbackError(final int qosCallbackId,
+            @QosCallbackException.ExceptionType final int exceptionType) {
+        queueOrSendMessage(ra -> ra.sendQosCallbackError(qosCallbackId, exceptionType));
+    }
+
+
     /** @hide */
-    protected void log(String s) {
+    protected void log(final String s) {
         Log.d(LOG_TAG, "NetworkAgent: " + s);
     }
 }
diff --git a/core/java/android/net/NetworkCapabilities.java b/core/java/android/net/NetworkCapabilities.java
index 2d9f6d8..0a895b9 100644
--- a/core/java/android/net/NetworkCapabilities.java
+++ b/core/java/android/net/NetworkCapabilities.java
@@ -23,7 +23,6 @@
 import android.annotation.Nullable;
 import android.annotation.RequiresPermission;
 import android.annotation.SystemApi;
-import android.annotation.TestApi;
 import android.compat.annotation.UnsupportedAppUsage;
 import android.net.ConnectivityManager.NetworkCallback;
 import android.os.Build;
@@ -576,7 +575,6 @@
      * @hide
      */
     @UnsupportedAppUsage
-    @TestApi
     public @NetCapability int[] getCapabilities() {
         return BitUtils.unpackBits(mNetworkCapabilities);
     }
@@ -821,7 +819,7 @@
      *
      * @hide
      */
-    @TestApi
+    @SystemApi(client = SystemApi.Client.MODULE_LIBRARIES)
     public static final int TRANSPORT_TEST = 7;
 
     /** @hide */
diff --git a/core/java/android/net/QosCallback.java b/core/java/android/net/QosCallback.java
new file mode 100644
index 0000000..22f06bc
--- /dev/null
+++ b/core/java/android/net/QosCallback.java
@@ -0,0 +1,91 @@
+/*
+ * Copyright (C) 2020 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;
+
+import android.annotation.NonNull;
+import android.annotation.SystemApi;
+
+import java.util.concurrent.Executor;
+
+/**
+ * Receives Qos information given a {@link Network}.  The callback is registered with
+ * {@link ConnectivityManager#registerQosCallback}.
+ *
+ * <p>
+ * <br/>
+ * The callback will no longer receive calls if any of the following takes place:
+ * <ol>
+ * <li>{@link ConnectivityManager#unregisterQosCallback(QosCallback)} is called with the same
+ * callback instance.</li>
+ * <li>{@link QosCallback#onError(QosCallbackException)} is called.</li>
+ * <li>A network specific issue occurs.  eg. Congestion on a carrier network.</li>
+ * <li>The network registered with the callback has no associated QoS providers</li>
+ * </ul>
+ * {@hide}
+ */
+@SystemApi
+public abstract class QosCallback {
+    /**
+     * Invoked after an error occurs on a registered callback.  Once called, the callback is
+     * automatically unregistered and the callback will no longer receive calls.
+     *
+     * <p>The underlying exception can either be a runtime exception or a custom exception made for
+     * {@link QosCallback}. see: {@link QosCallbackException}.
+     *
+     * @param exception wraps the underlying cause
+     */
+    public void onError(@NonNull final QosCallbackException exception) {
+    }
+
+    /**
+     * Called when a Qos Session first becomes available to the callback or if its attributes have
+     * changed.
+     * <p>
+     * Note: The callback may be called multiple times with the same attributes.
+     *
+     * @param session the available session
+     * @param sessionAttributes the attributes of the session
+     */
+    public void onQosSessionAvailable(@NonNull final QosSession session,
+            @NonNull final QosSessionAttributes sessionAttributes) {
+    }
+
+    /**
+     * Called after a Qos Session is lost.
+     * <p>
+     * At least one call to
+     * {@link QosCallback#onQosSessionAvailable(QosSession, QosSessionAttributes)}
+     * with the same {@link QosSession} will precede a call to lost.
+     *
+     * @param session the lost session
+     */
+    public void onQosSessionLost(@NonNull final QosSession session) {
+    }
+
+    /**
+     * Thrown when there is a problem registering {@link QosCallback} with
+     * {@link ConnectivityManager#registerQosCallback(QosSocketInfo, QosCallback, Executor)}.
+     */
+    public static class QosCallbackRegistrationException extends RuntimeException {
+        /**
+         * @hide
+         */
+        public QosCallbackRegistrationException() {
+            super();
+        }
+    }
+}
diff --git a/core/java/android/net/QosCallbackConnection.java b/core/java/android/net/QosCallbackConnection.java
new file mode 100644
index 0000000..bdb4ad6
--- /dev/null
+++ b/core/java/android/net/QosCallbackConnection.java
@@ -0,0 +1,128 @@
+/*
+ * Copyright (C) 2020 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;
+
+import android.annotation.NonNull;
+import android.annotation.Nullable;
+import android.telephony.data.EpsBearerQosSessionAttributes;
+
+import com.android.internal.annotations.VisibleForTesting;
+
+import java.util.Objects;
+import java.util.concurrent.Executor;
+
+/**
+ * Sends messages from {@link com.android.server.ConnectivityService} to the registered
+ * {@link QosCallback}.
+ * <p/>
+ * This is a satellite class of {@link ConnectivityManager} and not meant
+ * to be used in other contexts.
+ *
+ * @hide
+ */
+class QosCallbackConnection extends android.net.IQosCallback.Stub {
+
+    @NonNull private final ConnectivityManager mConnectivityManager;
+    @Nullable private volatile QosCallback mCallback;
+    @NonNull private final Executor mExecutor;
+
+    @VisibleForTesting
+    @Nullable
+    public QosCallback getCallback() {
+        return mCallback;
+    }
+
+    /**
+     * The constructor for the connection
+     *
+     * @param connectivityManager the mgr that created this connection
+     * @param callback the callback to send messages back to
+     * @param executor The executor on which the callback will be invoked. The provided
+     *                 {@link Executor} must run callback sequentially, otherwise the order of
+     *                 callbacks cannot be guaranteed.
+     */
+    QosCallbackConnection(@NonNull final ConnectivityManager connectivityManager,
+            @NonNull final QosCallback callback,
+            @NonNull final Executor executor) {
+        mConnectivityManager = Objects.requireNonNull(connectivityManager,
+                "connectivityManager must be non-null");
+        mCallback = Objects.requireNonNull(callback, "callback must be non-null");
+        mExecutor = Objects.requireNonNull(executor, "executor must be non-null");
+    }
+
+    /**
+     * Called when either the {@link EpsBearerQosSessionAttributes} has changed or on the first time
+     * the attributes have become available.
+     *
+     * @param session the session that is now available
+     * @param attributes the corresponding attributes of session
+     */
+    @Override
+    public void onQosEpsBearerSessionAvailable(@NonNull final QosSession session,
+            @NonNull final EpsBearerQosSessionAttributes attributes) {
+
+        mExecutor.execute(() -> {
+            final QosCallback callback = mCallback;
+            if (callback != null) {
+                callback.onQosSessionAvailable(session, attributes);
+            }
+        });
+    }
+
+    /**
+     * Called when the session is lost.
+     *
+     * @param session the session that was lost
+     */
+    @Override
+    public void onQosSessionLost(@NonNull final QosSession session) {
+        mExecutor.execute(() -> {
+            final QosCallback callback = mCallback;
+            if (callback != null) {
+                callback.onQosSessionLost(session);
+            }
+        });
+    }
+
+    /**
+     * Called when there is an error on the registered callback.
+     *
+     *  @param errorType the type of error
+     */
+    @Override
+    public void onError(@QosCallbackException.ExceptionType final int errorType) {
+        mExecutor.execute(() -> {
+            final QosCallback callback = mCallback;
+            if (callback != null) {
+                // Messages no longer need to be received since there was an error.
+                stopReceivingMessages();
+                mConnectivityManager.unregisterQosCallback(callback);
+                callback.onError(QosCallbackException.createException(errorType));
+            }
+        });
+    }
+
+    /**
+     * The callback will stop receiving messages.
+     * <p/>
+     * There are no synchronization guarantees on exactly when the callback will stop receiving
+     * messages.
+     */
+    void stopReceivingMessages() {
+        mCallback = null;
+    }
+}
diff --git a/core/java/android/net/QosCallbackException.java b/core/java/android/net/QosCallbackException.java
new file mode 100644
index 0000000..7fd9a52
--- /dev/null
+++ b/core/java/android/net/QosCallbackException.java
@@ -0,0 +1,110 @@
+/*
+ * Copyright (C) 2020 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;
+
+import android.annotation.IntDef;
+import android.annotation.NonNull;
+import android.annotation.SystemApi;
+import android.util.Log;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+
+/**
+ * This is the exception type passed back through the onError method on {@link QosCallback}.
+ * {@link QosCallbackException#getCause()} contains the actual error that caused this exception.
+ *
+ * The possible exception types as causes are:
+ * 1. {@link NetworkReleasedException}
+ * 2. {@link SocketNotBoundException}
+ * 3. {@link UnsupportedOperationException}
+ * 4. {@link SocketLocalAddressChangedException}
+ *
+ * @hide
+ */
+@SystemApi
+public final class QosCallbackException extends Exception {
+
+    /** @hide */
+    @IntDef(prefix = {"EX_TYPE_"}, value = {
+            EX_TYPE_FILTER_NONE,
+            EX_TYPE_FILTER_NETWORK_RELEASED,
+            EX_TYPE_FILTER_SOCKET_NOT_BOUND,
+            EX_TYPE_FILTER_NOT_SUPPORTED,
+            EX_TYPE_FILTER_SOCKET_LOCAL_ADDRESS_CHANGED,
+    })
+    @Retention(RetentionPolicy.SOURCE)
+    public @interface ExceptionType {}
+
+    private static final String TAG = "QosCallbackException";
+
+    // Types of exceptions supported //
+    /** {@hide} */
+    public static final int EX_TYPE_FILTER_NONE = 0;
+
+    /** {@hide} */
+    public static final int EX_TYPE_FILTER_NETWORK_RELEASED = 1;
+
+    /** {@hide} */
+    public static final int EX_TYPE_FILTER_SOCKET_NOT_BOUND = 2;
+
+    /** {@hide} */
+    public static final int EX_TYPE_FILTER_NOT_SUPPORTED = 3;
+
+    /** {@hide} */
+    public static final int EX_TYPE_FILTER_SOCKET_LOCAL_ADDRESS_CHANGED = 4;
+
+    /**
+     * Creates exception based off of a type and message.  Not all types of exceptions accept a
+     * custom message.
+     *
+     * {@hide}
+     */
+    @NonNull
+    static QosCallbackException createException(@ExceptionType final int type) {
+        switch (type) {
+            case EX_TYPE_FILTER_NETWORK_RELEASED:
+                return new QosCallbackException(new NetworkReleasedException());
+            case EX_TYPE_FILTER_SOCKET_NOT_BOUND:
+                return new QosCallbackException(new SocketNotBoundException());
+            case EX_TYPE_FILTER_NOT_SUPPORTED:
+                return new QosCallbackException(new UnsupportedOperationException(
+                        "This device does not support the specified filter"));
+            case EX_TYPE_FILTER_SOCKET_LOCAL_ADDRESS_CHANGED:
+                return new QosCallbackException(
+                        new SocketLocalAddressChangedException());
+            default:
+                Log.wtf(TAG, "create: No case setup for exception type: '" + type + "'");
+                return new QosCallbackException(
+                        new RuntimeException("Unknown exception code: " + type));
+        }
+    }
+
+    /**
+     * @hide
+     */
+    public QosCallbackException(@NonNull final String message) {
+        super(message);
+    }
+
+    /**
+     * @hide
+     */
+    public QosCallbackException(@NonNull final Throwable cause) {
+        super(cause);
+    }
+}
diff --git a/core/java/android/net/QosFilter.java b/core/java/android/net/QosFilter.java
new file mode 100644
index 0000000..0705468
--- /dev/null
+++ b/core/java/android/net/QosFilter.java
@@ -0,0 +1,62 @@
+/*
+ * Copyright (C) 2020 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;
+
+import android.annotation.NonNull;
+import android.annotation.SystemApi;
+
+/**
+ * Provides the related filtering logic to the {@link NetworkAgent} to match {@link QosSession}s
+ * to their related {@link QosCallback}.
+ *
+ * Used by the {@link com.android.server.ConnectivityService} to validate a {@link QosCallback}
+ * is still able to receive a {@link QosSession}.
+ *
+ * @hide
+ */
+@SystemApi
+public abstract class QosFilter {
+
+    /**
+     * The constructor is kept hidden from outside this package to ensure that all derived types
+     * are known and properly handled when being passed to and from {@link NetworkAgent}.
+     *
+     * @hide
+     */
+    QosFilter() {
+    }
+
+    /**
+     * The network used with this filter.
+     *
+     * @return the registered {@link Network}
+     */
+    @NonNull
+    public abstract Network getNetwork();
+
+    /**
+     * Validates that conditions have not changed such that no further {@link QosSession}s should
+     * be passed back to the {@link QosCallback} associated to this filter.
+     *
+     * @return the error code when present, otherwise the filter is valid
+     *
+     * @hide
+     */
+    @QosCallbackException.ExceptionType
+    public abstract int validate();
+}
+
diff --git a/core/java/android/net/QosFilterParcelable.java b/core/java/android/net/QosFilterParcelable.java
new file mode 100644
index 0000000..da3b2cf
--- /dev/null
+++ b/core/java/android/net/QosFilterParcelable.java
@@ -0,0 +1,113 @@
+/*
+ * Copyright (C) 2021 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;
+
+import android.annotation.NonNull;
+import android.annotation.Nullable;
+import android.os.Parcel;
+import android.os.Parcelable;
+import android.util.Log;
+
+import java.util.Objects;
+
+/**
+ * Aware of how to parcel different types of {@link QosFilter}s.  Any new type of qos filter must
+ * have a specialized case written here.
+ * <p/>
+ * Specifically leveraged when transferring {@link QosFilter} from
+ * {@link com.android.server.ConnectivityService} to {@link NetworkAgent} when the filter is first
+ * registered.
+ * <p/>
+ * This is not meant to be used in other contexts.
+ *
+ * @hide
+ */
+public final class QosFilterParcelable implements Parcelable {
+
+    private static final String LOG_TAG = QosFilterParcelable.class.getSimpleName();
+
+    // Indicates that the filter was not successfully written to the parcel.
+    private static final int NO_FILTER_PRESENT = 0;
+
+    // The parcel is of type qos socket filter.
+    private static final int QOS_SOCKET_FILTER = 1;
+
+    private final QosFilter mQosFilter;
+
+    /**
+     * The underlying qos filter.
+     * <p/>
+     * Null only in the case parceling failed.
+     */
+    @Nullable
+    public QosFilter getQosFilter() {
+        return mQosFilter;
+    }
+
+    public QosFilterParcelable(@NonNull final QosFilter qosFilter) {
+        Objects.requireNonNull(qosFilter, "qosFilter must be non-null");
+
+        // NOTE: Normally a type check would belong here, but doing so breaks unit tests that rely
+        // on mocking qos filter.
+        mQosFilter = qosFilter;
+    }
+
+    private QosFilterParcelable(final Parcel in) {
+        final int filterParcelType = in.readInt();
+
+        switch (filterParcelType) {
+            case QOS_SOCKET_FILTER: {
+                mQosFilter = new QosSocketFilter(QosSocketInfo.CREATOR.createFromParcel(in));
+                break;
+            }
+
+            case NO_FILTER_PRESENT:
+            default: {
+                mQosFilter = null;
+            }
+        }
+    }
+
+    public static final Creator<QosFilterParcelable> CREATOR = new Creator<QosFilterParcelable>() {
+        @Override
+        public QosFilterParcelable createFromParcel(final Parcel in) {
+            return new QosFilterParcelable(in);
+        }
+
+        @Override
+        public QosFilterParcelable[] newArray(final int size) {
+            return new QosFilterParcelable[size];
+        }
+    };
+
+    @Override
+    public int describeContents() {
+        return 0;
+    }
+
+    @Override
+    public void writeToParcel(final Parcel dest, final int flags) {
+        if (mQosFilter instanceof QosSocketFilter) {
+            dest.writeInt(QOS_SOCKET_FILTER);
+            final QosSocketFilter qosSocketFilter = (QosSocketFilter) mQosFilter;
+            qosSocketFilter.getQosSocketInfo().writeToParcel(dest, 0);
+            return;
+        }
+        dest.writeInt(NO_FILTER_PRESENT);
+        Log.e(LOG_TAG, "Parceling failed, unknown type of filter present: " + mQosFilter);
+    }
+}
diff --git a/core/java/android/net/QosSession.java b/core/java/android/net/QosSession.java
new file mode 100644
index 0000000..4f3bb77
--- /dev/null
+++ b/core/java/android/net/QosSession.java
@@ -0,0 +1,136 @@
+/*
+ * Copyright (C) 2020 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;
+
+import android.annotation.IntDef;
+import android.annotation.NonNull;
+import android.annotation.SystemApi;
+import android.os.Parcel;
+import android.os.Parcelable;
+
+/**
+ * Provides identifying information of a QoS session.  Sent to an application through
+ * {@link QosCallback}.
+ *
+ * @hide
+ */
+@SystemApi
+public final class QosSession implements Parcelable {
+
+    /**
+     * The {@link QosSession} is a LTE EPS Session.
+     */
+    public static final int TYPE_EPS_BEARER = 1;
+
+    private final int mSessionId;
+
+    private final int mSessionType;
+
+    /**
+     * Gets the unique id of the session that is used to differentiate sessions across different
+     * types.
+     * <p/>
+     * Note: Different qos sessions can be provided by different actors.
+     *
+     * @return the unique id
+     */
+    public long getUniqueId() {
+        return (long) mSessionType << 32 | mSessionId;
+    }
+
+    /**
+     * Gets the session id that is unique within that type.
+     * <p/>
+     * Note: The session id is set by the actor providing the qos.  It can be either manufactured by
+     * the actor, but also may have a particular meaning within that type.  For example, using the
+     * bearer id as the session id for {@link android.telephony.data.EpsBearerQosSessionAttributes}
+     * is a straight forward way to keep the sessions unique from one another within that type.
+     *
+     * @return the id of the session
+     */
+    public int getSessionId() {
+        return mSessionId;
+    }
+
+    /**
+     * Gets the type of session.
+     */
+    @QosSessionType
+    public int getSessionType() {
+        return mSessionType;
+    }
+
+    /**
+     * Creates a {@link QosSession}.
+     *
+     * @param sessionId uniquely identifies the session across all sessions of the same type
+     * @param sessionType the type of session
+     */
+    public QosSession(final int sessionId, @QosSessionType final int sessionType) {
+        //Ensures the session id is unique across types of sessions
+        mSessionId = sessionId;
+        mSessionType = sessionType;
+    }
+
+
+    @Override
+    public String toString() {
+        return "QosSession{"
+                + "mSessionId=" + mSessionId
+                + ", mSessionType=" + mSessionType
+                + '}';
+    }
+
+    /**
+     * Annotations for types of qos sessions.
+     */
+    @IntDef(value = {
+            TYPE_EPS_BEARER,
+    })
+    @interface QosSessionType {}
+
+    private QosSession(final Parcel in) {
+        mSessionId = in.readInt();
+        mSessionType = in.readInt();
+    }
+
+    @NonNull
+    public static final Creator<QosSession> CREATOR = new Creator<QosSession>() {
+        @NonNull
+        @Override
+        public QosSession createFromParcel(@NonNull final Parcel in) {
+            return new QosSession(in);
+        }
+
+        @NonNull
+        @Override
+        public QosSession[] newArray(final int size) {
+            return new QosSession[size];
+        }
+    };
+
+    @Override
+    public int describeContents() {
+        return 0;
+    }
+
+    @Override
+    public void writeToParcel(@NonNull final Parcel dest, final int flags) {
+        dest.writeInt(mSessionId);
+        dest.writeInt(mSessionType);
+    }
+}
diff --git a/core/java/android/net/QosSocketFilter.java b/core/java/android/net/QosSocketFilter.java
new file mode 100644
index 0000000..f51a088
--- /dev/null
+++ b/core/java/android/net/QosSocketFilter.java
@@ -0,0 +1,128 @@
+/*
+ * Copyright (C) 2020 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;
+
+import static android.net.QosCallbackException.EX_TYPE_FILTER_NONE;
+import static android.net.QosCallbackException.EX_TYPE_FILTER_SOCKET_LOCAL_ADDRESS_CHANGED;
+
+import android.annotation.NonNull;
+import android.annotation.Nullable;
+import android.os.ParcelFileDescriptor;
+import android.system.ErrnoException;
+import android.system.Os;
+import android.util.Log;
+
+import java.io.FileDescriptor;
+import java.net.InetSocketAddress;
+import java.net.Socket;
+import java.net.SocketAddress;
+import java.util.Objects;
+
+/**
+ * Filters a {@link QosSession} according to the binding on the provided {@link Socket}.
+ *
+ * @hide
+ */
+public class QosSocketFilter extends QosFilter {
+
+    private static final String TAG = QosSocketFilter.class.getSimpleName();
+
+    @NonNull
+    private final QosSocketInfo mQosSocketInfo;
+
+    /**
+     * Creates a {@link QosSocketFilter} based off of {@link QosSocketInfo}.
+     *
+     * @param qosSocketInfo the information required to filter and validate
+     */
+    public QosSocketFilter(@NonNull final QosSocketInfo qosSocketInfo) {
+        Objects.requireNonNull(qosSocketInfo, "qosSocketInfo must be non-null");
+        mQosSocketInfo = qosSocketInfo;
+    }
+
+    /**
+     * Gets the parcelable qos socket info that was used to create the filter.
+     */
+    @NonNull
+    public QosSocketInfo getQosSocketInfo() {
+        return mQosSocketInfo;
+    }
+
+    /**
+     * Performs two validations:
+     * 1. If the socket is not bound, then return
+     *    {@link QosCallbackException.EX_TYPE_FILTER_SOCKET_NOT_BOUND}. This is detected
+     *    by checking the local address on the filter which becomes null when the socket is no
+     *    longer bound.
+     * 2. In the scenario that the socket is now bound to a different local address, which can
+     *    happen in the case of UDP, then
+     *    {@link QosCallbackException.EX_TYPE_FILTER_SOCKET_LOCAL_ADDRESS_CHANGED} is returned.
+     * @return validation error code
+     */
+    @Override
+    public int validate() {
+        final InetSocketAddress sa = getAddressFromFileDescriptor();
+        if (sa == null) {
+            return QosCallbackException.EX_TYPE_FILTER_SOCKET_NOT_BOUND;
+        }
+
+        if (!sa.equals(mQosSocketInfo.getLocalSocketAddress())) {
+            return EX_TYPE_FILTER_SOCKET_LOCAL_ADDRESS_CHANGED;
+        }
+
+        return EX_TYPE_FILTER_NONE;
+    }
+
+    /**
+     * The local address of the socket's binding.
+     *
+     * Note: If the socket is no longer bound, null is returned.
+     *
+     * @return the local address
+     */
+    @Nullable
+    private InetSocketAddress getAddressFromFileDescriptor() {
+        final ParcelFileDescriptor parcelFileDescriptor = mQosSocketInfo.getParcelFileDescriptor();
+        if (parcelFileDescriptor == null) return null;
+
+        final FileDescriptor fd = parcelFileDescriptor.getFileDescriptor();
+        if (fd == null) return null;
+
+        final SocketAddress address;
+        try {
+            address = Os.getsockname(fd);
+        } catch (final ErrnoException e) {
+            Log.e(TAG, "getAddressFromFileDescriptor: getLocalAddress exception", e);
+            return null;
+        }
+        if (address instanceof InetSocketAddress) {
+            return (InetSocketAddress) address;
+        }
+        return null;
+    }
+
+    /**
+     * The network used with this filter.
+     *
+     * @return the registered {@link Network}
+     */
+    @NonNull
+    @Override
+    public Network getNetwork() {
+        return mQosSocketInfo.getNetwork();
+    }
+}
diff --git a/core/java/android/net/QosSocketInfo.java b/core/java/android/net/QosSocketInfo.java
new file mode 100644
index 0000000..d37c469
--- /dev/null
+++ b/core/java/android/net/QosSocketInfo.java
@@ -0,0 +1,154 @@
+/*
+ * Copyright (C) 2020 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;
+
+import android.annotation.NonNull;
+import android.annotation.SystemApi;
+import android.os.Parcel;
+import android.os.ParcelFileDescriptor;
+import android.os.Parcelable;
+
+import java.io.IOException;
+import java.net.InetAddress;
+import java.net.InetSocketAddress;
+import java.net.Socket;
+import java.net.UnknownHostException;
+import java.util.Objects;
+
+/**
+ * Used in conjunction with
+ * {@link ConnectivityManager#registerQosCallback}
+ * in order to receive Qos Sessions related to the local address and port of a bound {@link Socket}.
+ *
+ * @hide
+ */
+@SystemApi
+public final class QosSocketInfo implements Parcelable {
+
+    @NonNull
+    private final Network mNetwork;
+
+    @NonNull
+    private final ParcelFileDescriptor mParcelFileDescriptor;
+
+    @NonNull
+    private final InetSocketAddress mLocalSocketAddress;
+
+    /**
+     * The {@link Network} the socket is on.
+     *
+     * @return the registered {@link Network}
+     */
+    @NonNull
+    public Network getNetwork() {
+        return mNetwork;
+    }
+
+    /**
+     * The parcel file descriptor wrapped around the socket's file descriptor.
+     *
+     * @return the parcel file descriptor of the socket
+     */
+    @NonNull
+    ParcelFileDescriptor getParcelFileDescriptor() {
+        return mParcelFileDescriptor;
+    }
+
+    /**
+     * The local address of the socket passed into {@link QosSocketInfo(Network, Socket)}.
+     * The value does not reflect any changes that occur to the socket after it is first set
+     * in the constructor.
+     *
+     * @return the local address of the socket
+     */
+    @NonNull
+    public InetSocketAddress getLocalSocketAddress() {
+        return mLocalSocketAddress;
+    }
+
+    /**
+     * Creates a {@link QosSocketInfo} given a {@link Network} and bound {@link Socket}.  The
+     * {@link Socket} must remain bound in order to receive {@link QosSession}s.
+     *
+     * @param network the network
+     * @param socket the bound {@link Socket}
+     */
+    public QosSocketInfo(@NonNull final Network network, @NonNull final Socket socket)
+            throws IOException {
+        Objects.requireNonNull(socket, "socket cannot be null");
+
+        mNetwork = Objects.requireNonNull(network, "network cannot be null");
+        mParcelFileDescriptor = ParcelFileDescriptor.dup(socket.getFileDescriptor$());
+        mLocalSocketAddress =
+                new InetSocketAddress(socket.getLocalAddress(), socket.getLocalPort());
+    }
+
+    /* Parcelable methods */
+    private QosSocketInfo(final Parcel in) {
+        mNetwork = Objects.requireNonNull(Network.CREATOR.createFromParcel(in));
+        mParcelFileDescriptor = ParcelFileDescriptor.CREATOR.createFromParcel(in);
+
+        final int addressLength = in.readInt();
+        mLocalSocketAddress = readSocketAddress(in, addressLength);
+    }
+
+    private InetSocketAddress readSocketAddress(final Parcel in, final int addressLength) {
+        final byte[] address = new byte[addressLength];
+        in.readByteArray(address);
+        final int port = in.readInt();
+
+        try {
+            return new InetSocketAddress(InetAddress.getByAddress(address), port);
+        } catch (final UnknownHostException e) {
+            /* The catch block was purposely left empty.  UnknownHostException will never be thrown
+               since the address provided is numeric and non-null. */
+        }
+        return new InetSocketAddress();
+    }
+
+    @Override
+    public int describeContents() {
+        return 0;
+    }
+
+    @Override
+    public void writeToParcel(@NonNull final Parcel dest, final int flags) {
+        mNetwork.writeToParcel(dest, 0);
+        mParcelFileDescriptor.writeToParcel(dest, 0);
+
+        final byte[] address = mLocalSocketAddress.getAddress().getAddress();
+        dest.writeInt(address.length);
+        dest.writeByteArray(address);
+        dest.writeInt(mLocalSocketAddress.getPort());
+    }
+
+    @NonNull
+    public static final Parcelable.Creator<QosSocketInfo> CREATOR =
+            new Parcelable.Creator<QosSocketInfo>() {
+            @NonNull
+            @Override
+            public QosSocketInfo createFromParcel(final Parcel in) {
+                return new QosSocketInfo(in);
+            }
+
+            @NonNull
+            @Override
+            public QosSocketInfo[] newArray(final int size) {
+                return new QosSocketInfo[size];
+            }
+        };
+}
diff --git a/core/java/android/net/TcpSocketKeepalive.java b/core/java/android/net/TcpSocketKeepalive.java
index 436397e..d89814d 100644
--- a/core/java/android/net/TcpSocketKeepalive.java
+++ b/core/java/android/net/TcpSocketKeepalive.java
@@ -21,7 +21,6 @@
 import android.os.RemoteException;
 import android.util.Log;
 
-import java.io.FileDescriptor;
 import java.util.concurrent.Executor;
 
 /** @hide */
@@ -54,8 +53,7 @@
     void startImpl(int intervalSec) {
         mExecutor.execute(() -> {
             try {
-                final FileDescriptor fd = mPfd.getFileDescriptor();
-                mService.startTcpKeepalive(mNetwork, fd, intervalSec, mCallback);
+                mService.startTcpKeepalive(mNetwork, mPfd, intervalSec, mCallback);
             } catch (RemoteException e) {
                 Log.e(TAG, "Error starting packet keepalive: ", e);
                 throw e.rethrowFromSystemServer();
diff --git a/core/java/android/net/TestNetworkInterface.java b/core/java/android/net/TestNetworkInterface.java
index 8455083..4449ff8 100644
--- a/core/java/android/net/TestNetworkInterface.java
+++ b/core/java/android/net/TestNetworkInterface.java
@@ -15,7 +15,8 @@
  */
 package android.net;
 
-import android.annotation.TestApi;
+import android.annotation.NonNull;
+import android.annotation.SystemApi;
 import android.os.Parcel;
 import android.os.ParcelFileDescriptor;
 import android.os.Parcelable;
@@ -25,9 +26,11 @@
  *
  * @hide
  */
-@TestApi
+@SystemApi(client = SystemApi.Client.MODULE_LIBRARIES)
 public final class TestNetworkInterface implements Parcelable {
+    @NonNull
     private final ParcelFileDescriptor mFileDescriptor;
+    @NonNull
     private final String mInterfaceName;
 
     @Override
@@ -36,29 +39,32 @@
     }
 
     @Override
-    public void writeToParcel(Parcel out, int flags) {
+    public void writeToParcel(@NonNull Parcel out, int flags) {
         out.writeParcelable(mFileDescriptor, PARCELABLE_WRITE_RETURN_VALUE);
         out.writeString(mInterfaceName);
     }
 
-    public TestNetworkInterface(ParcelFileDescriptor pfd, String intf) {
+    public TestNetworkInterface(@NonNull ParcelFileDescriptor pfd, @NonNull String intf) {
         mFileDescriptor = pfd;
         mInterfaceName = intf;
     }
 
-    private TestNetworkInterface(Parcel in) {
+    private TestNetworkInterface(@NonNull Parcel in) {
         mFileDescriptor = in.readParcelable(ParcelFileDescriptor.class.getClassLoader());
         mInterfaceName = in.readString();
     }
 
+    @NonNull
     public ParcelFileDescriptor getFileDescriptor() {
         return mFileDescriptor;
     }
 
+    @NonNull
     public String getInterfaceName() {
         return mInterfaceName;
     }
 
+    @NonNull
     public static final Parcelable.Creator<TestNetworkInterface> CREATOR =
             new Parcelable.Creator<TestNetworkInterface>() {
                 public TestNetworkInterface createFromParcel(Parcel in) {
diff --git a/core/java/android/net/TestNetworkManager.java b/core/java/android/net/TestNetworkManager.java
index a0a563b..4e89414 100644
--- a/core/java/android/net/TestNetworkManager.java
+++ b/core/java/android/net/TestNetworkManager.java
@@ -17,18 +17,21 @@
 
 import android.annotation.NonNull;
 import android.annotation.Nullable;
-import android.annotation.TestApi;
+import android.annotation.SystemApi;
 import android.os.IBinder;
 import android.os.RemoteException;
 
 import com.android.internal.util.Preconditions;
 
+import java.util.Arrays;
+import java.util.Collection;
+
 /**
  * Class that allows creation and management of per-app, test-only networks
  *
  * @hide
  */
-@TestApi
+@SystemApi(client = SystemApi.Client.MODULE_LIBRARIES)
 public class TestNetworkManager {
     /**
      * Prefix for tun interfaces created by this class.
@@ -57,7 +60,7 @@
      * @param network The test network that should be torn down
      * @hide
      */
-    @TestApi
+    @SystemApi(client = SystemApi.Client.MODULE_LIBRARIES)
     public void teardownTestNetwork(@NonNull Network network) {
         try {
             mService.teardownTestNetwork(network.netId);
@@ -102,7 +105,7 @@
      * @param binder A binder object guarding the lifecycle of this test network.
      * @hide
      */
-    @TestApi
+    @SystemApi(client = SystemApi.Client.MODULE_LIBRARIES)
     public void setupTestNetwork(@NonNull String iface, @NonNull IBinder binder) {
         setupTestNetwork(iface, null, true, new int[0], binder);
     }
@@ -127,12 +130,29 @@
      * @param linkAddrs an array of LinkAddresses to assign to the TUN interface
      * @return A ParcelFileDescriptor of the underlying TUN interface. Close this to tear down the
      *     TUN interface.
+     * @deprecated Use {@link #createTunInterface(Collection)} instead.
      * @hide
      */
-    @TestApi
+    @Deprecated
+    @NonNull
     public TestNetworkInterface createTunInterface(@NonNull LinkAddress[] linkAddrs) {
+        return createTunInterface(Arrays.asList(linkAddrs));
+    }
+
+    /**
+     * Create a tun interface for testing purposes
+     *
+     * @param linkAddrs an array of LinkAddresses to assign to the TUN interface
+     * @return A ParcelFileDescriptor of the underlying TUN interface. Close this to tear down the
+     *     TUN interface.
+     * @hide
+     */
+    @SystemApi(client = SystemApi.Client.MODULE_LIBRARIES)
+    @NonNull
+    public TestNetworkInterface createTunInterface(@NonNull Collection<LinkAddress> linkAddrs) {
         try {
-            return mService.createTunInterface(linkAddrs);
+            final LinkAddress[] arr = new LinkAddress[linkAddrs.size()];
+            return mService.createTunInterface(linkAddrs.toArray(arr));
         } catch (RemoteException e) {
             throw e.rethrowFromSystemServer();
         }
@@ -145,7 +165,8 @@
      *     TAP interface.
      * @hide
      */
-    @TestApi
+    @SystemApi(client = SystemApi.Client.MODULE_LIBRARIES)
+    @NonNull
     public TestNetworkInterface createTapInterface() {
         try {
             return mService.createTapInterface();
diff --git a/core/java/android/net/util/MultinetworkPolicyTracker.java b/core/java/android/net/util/MultinetworkPolicyTracker.java
index 8dfd4e1..85e3fa3 100644
--- a/core/java/android/net/util/MultinetworkPolicyTracker.java
+++ b/core/java/android/net/util/MultinetworkPolicyTracker.java
@@ -29,7 +29,6 @@
 import android.database.ContentObserver;
 import android.net.Uri;
 import android.os.Handler;
-import android.os.UserHandle;
 import android.provider.Settings;
 import android.telephony.PhoneStateListener;
 import android.telephony.SubscriptionManager;
@@ -114,8 +113,8 @@
 
         final IntentFilter intentFilter = new IntentFilter();
         intentFilter.addAction(Intent.ACTION_CONFIGURATION_CHANGED);
-        mContext.registerReceiverAsUser(
-                mBroadcastReceiver, UserHandle.ALL, intentFilter, null, mHandler);
+        mContext.registerReceiverForAllUsers(mBroadcastReceiver, intentFilter,
+                null /* broadcastPermission */, mHandler);
 
         reevaluate();
     }
diff --git a/services/core/java/com/android/server/ConnectivityService.java b/services/core/java/com/android/server/ConnectivityService.java
index 6b45abd..b6232a0 100644
--- a/services/core/java/com/android/server/ConnectivityService.java
+++ b/services/core/java/com/android/server/ConnectivityService.java
@@ -94,6 +94,7 @@
 import android.net.INetworkMonitorCallbacks;
 import android.net.INetworkPolicyListener;
 import android.net.INetworkStatsService;
+import android.net.IQosCallback;
 import android.net.ISocketKeepaliveCallback;
 import android.net.InetAddresses;
 import android.net.IpMemoryStore;
@@ -121,6 +122,10 @@
 import android.net.NetworkWatchlistManager;
 import android.net.PrivateDnsConfigParcel;
 import android.net.ProxyInfo;
+import android.net.QosCallbackException;
+import android.net.QosFilter;
+import android.net.QosSocketFilter;
+import android.net.QosSocketInfo;
 import android.net.RouteInfo;
 import android.net.RouteInfoParcel;
 import android.net.SocketKeepalive;
@@ -194,7 +199,6 @@
 import com.android.server.connectivity.DataConnectionStats;
 import com.android.server.connectivity.DnsManager;
 import com.android.server.connectivity.DnsManager.PrivateDnsValidationUpdate;
-import com.android.server.connectivity.IpConnectivityMetrics;
 import com.android.server.connectivity.KeepaliveTracker;
 import com.android.server.connectivity.LingerMonitor;
 import com.android.server.connectivity.MockableSystemProperties;
@@ -205,6 +209,7 @@
 import com.android.server.connectivity.NetworkRanker;
 import com.android.server.connectivity.PermissionMonitor;
 import com.android.server.connectivity.ProxyTracker;
+import com.android.server.connectivity.QosCallbackTracker;
 import com.android.server.connectivity.Vpn;
 import com.android.server.net.BaseNetworkObserver;
 import com.android.server.net.LockdownVpnTracker;
@@ -280,6 +285,10 @@
     // Default to 30s linger time-out. Modifiable only for testing.
     private static final String LINGER_DELAY_PROPERTY = "persist.netmon.linger";
     private static final int DEFAULT_LINGER_DELAY_MS = 30_000;
+
+    // The maximum number of network request allowed per uid before an exception is thrown.
+    private static final int MAX_NETWORK_REQUESTS_PER_UID = 100;
+
     @VisibleForTesting
     protected int mLingerDelayMs;  // Can't be final, or test subclass constructors can't change it.
 
@@ -292,6 +301,8 @@
     @VisibleForTesting
     protected final PermissionMonitor mPermissionMonitor;
 
+    private final PerUidCounter mNetworkRequestCounter;
+
     private KeyStore mKeyStore;
 
     @VisibleForTesting
@@ -615,6 +626,7 @@
     private final LocationPermissionChecker mLocationPermissionChecker;
 
     private KeepaliveTracker mKeepaliveTracker;
+    private QosCallbackTracker mQosCallbackTracker;
     private NetworkNotificationManager mNotifier;
     private LingerMonitor mLingerMonitor;
 
@@ -859,6 +871,66 @@
     };
 
     /**
+     * Keeps track of the number of requests made under different uids.
+     */
+    public static class PerUidCounter {
+        private final int mMaxCountPerUid;
+
+        // Map from UID to number of NetworkRequests that UID has filed.
+        @GuardedBy("mUidToNetworkRequestCount")
+        private final SparseIntArray mUidToNetworkRequestCount = new SparseIntArray();
+
+        /**
+         * Constructor
+         *
+         * @param maxCountPerUid the maximum count per uid allowed
+         */
+        public PerUidCounter(final int maxCountPerUid) {
+            mMaxCountPerUid = maxCountPerUid;
+        }
+
+        /**
+         * Increments the request count of the given uid.  Throws an exception if the number
+         * of open requests for the uid exceeds the value of maxCounterPerUid which is the value
+         * passed into the constructor. see: {@link #PerUidCounter(int)}.
+         *
+         * @throws ServiceSpecificException with
+         * {@link ConnectivityManager.Errors.TOO_MANY_REQUESTS} if the number of requests for
+         * the uid exceed the allowed number.
+         *
+         * @param uid the uid that the request was made under
+         */
+        public void incrementCountOrThrow(final int uid) {
+            synchronized (mUidToNetworkRequestCount) {
+                final int networkRequests = mUidToNetworkRequestCount.get(uid, 0) + 1;
+                if (networkRequests >= mMaxCountPerUid) {
+                    throw new ServiceSpecificException(
+                            ConnectivityManager.Errors.TOO_MANY_REQUESTS);
+                }
+                mUidToNetworkRequestCount.put(uid, networkRequests);
+            }
+        }
+
+        /**
+         * Decrements the request count of the given uid.
+         *
+         * @param uid the uid that the request was made under
+         */
+        public void decrementCount(final int uid) {
+            synchronized (mUidToNetworkRequestCount) {
+                final int requests = mUidToNetworkRequestCount.get(uid, 0);
+                if (requests < 1) {
+                    logwtf("BUG: too small request count " + requests + " for UID " + uid);
+                } else if (requests == 1) {
+                    mUidToNetworkRequestCount.delete(uid);
+                } else {
+                    mUidToNetworkRequestCount.put(uid, requests - 1);
+                }
+            }
+        }
+    }
+
+    /**
      * Dependencies of ConnectivityService, for injection in tests.
      */
     @VisibleForTesting
@@ -889,6 +961,13 @@
         }
 
         /**
+         * Get a reference to the system keystore.
+         */
+        public KeyStore getKeyStore() {
+            return KeyStore.getInstance();
+        }
+
+        /**
          * @see ProxyTracker
          */
         public ProxyTracker makeProxyTracker(@NonNull Context context,
@@ -918,14 +997,6 @@
             return new MultinetworkPolicyTracker(c, h, r);
         }
 
-        /**
-         * @see IpConnectivityMetrics.Logger
-         */
-        public IpConnectivityMetrics.Logger getMetricsLogger() {
-            return Objects.requireNonNull(LocalServices.getService(IpConnectivityMetrics.Logger.class),
-                    "no IpConnectivityMetrics service");
-        }
-
         public IBatteryStats getBatteryStatsService() {
             return BatteryStatsService.getService();
         }
@@ -947,6 +1018,7 @@
         mSystemProperties = mDeps.getSystemProperties();
         mNetIdManager = mDeps.makeNetIdManager();
         mContext = Objects.requireNonNull(context, "missing Context");
+        mNetworkRequestCounter = new PerUidCounter(MAX_NETWORK_REQUESTS_PER_UID);
 
         mMetricsLog = logger;
         mDefaultRequest = createDefaultInternetRequestForTransport(-1, NetworkRequest.Type.REQUEST);
@@ -990,7 +1062,7 @@
         mProxyTracker = mDeps.makeProxyTracker(mContext, mHandler);
 
         mNetd = netd;
-        mKeyStore = KeyStore.getInstance();
+        mKeyStore = mDeps.getKeyStore();
         mTelephonyManager = (TelephonyManager) mContext.getSystemService(Context.TELEPHONY_SERVICE);
         mAppOpsManager = (AppOpsManager) mContext.getSystemService(Context.APP_OPS_SERVICE);
         mLocationPermissionChecker = new LocationPermissionChecker(mContext);
@@ -1117,11 +1189,7 @@
         userAllContext.registerReceiver(
                 mIntentReceiver, intentFilter, NETWORK_STACK, mHandler);
 
-        try {
-            mNMS.registerObserver(mDataActivityObserver);
-        } catch (RemoteException e) {
-            loge("Error registering observer :" + e);
-        }
+        mNetworkActivityTracker = new LegacyNetworkActivityTracker(mContext, mNMS);
 
         mSettingsObserver = new SettingsObserver(mContext, mHandler);
         registerSettingsCallbacks();
@@ -1131,6 +1199,7 @@
 
         mKeepaliveTracker = new KeepaliveTracker(mContext, mHandler);
         mNotifier = new NetworkNotificationManager(mContext, mTelephonyManager);
+        mQosCallbackTracker = new QosCallbackTracker(mHandler, mNetworkRequestCounter);
 
         final int dailyLimit = Settings.Global.getInt(mContext.getContentResolver(),
                 Settings.Global.NETWORK_SWITCH_NOTIFICATION_DAILY_LIMIT,
@@ -1653,7 +1722,6 @@
     private NetworkCapabilities getNetworkCapabilitiesInternal(NetworkAgentInfo nai) {
         if (nai == null) return null;
         synchronized (nai) {
-            if (nai.networkCapabilities == null) return null;
             return networkCapabilitiesRestrictedForCallerPermissions(
                     nai.networkCapabilities, Binder.getCallingPid(), mDeps.getCallingUid());
         }
@@ -1805,30 +1873,6 @@
         }
     }
 
-    private INetworkManagementEventObserver mDataActivityObserver = new BaseNetworkObserver() {
-        @Override
-        public void interfaceClassDataActivityChanged(int transportType, boolean active,
-                long tsNanos, int uid) {
-            sendDataActivityBroadcast(transportTypeToLegacyType(transportType), active, tsNanos);
-        }
-    };
-
-    // This is deprecated and only to support legacy use cases.
-    private int transportTypeToLegacyType(int type) {
-        switch (type) {
-            case NetworkCapabilities.TRANSPORT_CELLULAR:
-                return ConnectivityManager.TYPE_MOBILE;
-            case NetworkCapabilities.TRANSPORT_WIFI:
-                return ConnectivityManager.TYPE_WIFI;
-            case NetworkCapabilities.TRANSPORT_BLUETOOTH:
-                return ConnectivityManager.TYPE_BLUETOOTH;
-            case NetworkCapabilities.TRANSPORT_ETHERNET:
-                return ConnectivityManager.TYPE_ETHERNET;
-            default:
-                loge("Unexpected transport in transportTypeToLegacyType: " + type);
-        }
-        return ConnectivityManager.TYPE_NONE;
-    }
     /**
      * Ensures that the system cannot call a particular method.
      */
@@ -2277,20 +2321,6 @@
         sendStickyBroadcast(makeGeneralIntent(info, bcastType));
     }
 
-    private void sendDataActivityBroadcast(int deviceType, boolean active, long tsNanos) {
-        Intent intent = new Intent(ConnectivityManager.ACTION_DATA_ACTIVITY_CHANGE);
-        intent.putExtra(ConnectivityManager.EXTRA_DEVICE_TYPE, deviceType);
-        intent.putExtra(ConnectivityManager.EXTRA_IS_ACTIVE, active);
-        intent.putExtra(ConnectivityManager.EXTRA_REALTIME_NS, tsNanos);
-        final long ident = Binder.clearCallingIdentity();
-        try {
-            mContext.sendOrderedBroadcastAsUser(intent, UserHandle.ALL,
-                    RECEIVE_DATA_ACTIVITY_CHANGE, null, null, 0, null, null);
-        } finally {
-            Binder.restoreCallingIdentity(ident);
-        }
-    }
-
     private void sendStickyBroadcast(Intent intent) {
         synchronized (this) {
             if (!mSystemReady
@@ -2396,74 +2426,6 @@
     }
 
     /**
-     * Setup data activity tracking for the given network.
-     *
-     * Every {@code setupDataActivityTracking} should be paired with a
-     * {@link #removeDataActivityTracking} for cleanup.
-     */
-    private void setupDataActivityTracking(NetworkAgentInfo networkAgent) {
-        final String iface = networkAgent.linkProperties.getInterfaceName();
-
-        final int timeout;
-        final int type;
-
-        if (networkAgent.networkCapabilities.hasTransport(
-                NetworkCapabilities.TRANSPORT_CELLULAR)) {
-            timeout = Settings.Global.getInt(mContext.getContentResolver(),
-                                             Settings.Global.DATA_ACTIVITY_TIMEOUT_MOBILE,
-                                             10);
-            type = NetworkCapabilities.TRANSPORT_CELLULAR;
-        } else if (networkAgent.networkCapabilities.hasTransport(
-                NetworkCapabilities.TRANSPORT_WIFI)) {
-            timeout = Settings.Global.getInt(mContext.getContentResolver(),
-                                             Settings.Global.DATA_ACTIVITY_TIMEOUT_WIFI,
-                                             15);
-            type = NetworkCapabilities.TRANSPORT_WIFI;
-        } else {
-            return; // do not track any other networks
-        }
-
-        if (timeout > 0 && iface != null) {
-            try {
-                mNMS.addIdleTimer(iface, timeout, type);
-            } catch (Exception e) {
-                // You shall not crash!
-                loge("Exception in setupDataActivityTracking " + e);
-            }
-        }
-    }
-
-    /**
-     * Remove data activity tracking when network disconnects.
-     */
-    private void removeDataActivityTracking(NetworkAgentInfo networkAgent) {
-        final String iface = networkAgent.linkProperties.getInterfaceName();
-        final NetworkCapabilities caps = networkAgent.networkCapabilities;
-
-        if (iface != null && (caps.hasTransport(NetworkCapabilities.TRANSPORT_CELLULAR) ||
-                              caps.hasTransport(NetworkCapabilities.TRANSPORT_WIFI))) {
-            try {
-                // the call fails silently if no idle timer setup for this interface
-                mNMS.removeIdleTimer(iface);
-            } catch (Exception e) {
-                loge("Exception in removeDataActivityTracking " + e);
-            }
-        }
-    }
-
-    /**
-     * Update data activity tracking when network state is updated.
-     */
-    private void updateDataActivityTracking(NetworkAgentInfo newNetwork,
-            NetworkAgentInfo oldNetwork) {
-        if (newNetwork != null) {
-            setupDataActivityTracking(newNetwork);
-        }
-        if (oldNetwork != null) {
-            removeDataActivityTracking(oldNetwork);
-        }
-    }
-    /**
      * Reads the network specific MTU size from resources.
      * and set it on it's iface.
      */
@@ -2777,7 +2739,6 @@
     }
 
     private boolean isLiveNetworkAgent(NetworkAgentInfo nai, int what) {
-        if (nai.network == null) return false;
         final NetworkAgentInfo officialNai = getNetworkAgentInfoForNetwork(nai.network);
         if (officialNai != null && officialNai.equals(nai)) return true;
         if (officialNai != null || VDBG) {
@@ -2878,13 +2839,7 @@
                         Log.wtf(TAG, "Non-virtual networks cannot have underlying networks");
                         break;
                     }
-                    final ArrayList<Network> underlying;
-                    try {
-                        underlying = ((Bundle) arg.second).getParcelableArrayList(
-                                NetworkAgent.UNDERLYING_NETWORKS_KEY);
-                    } catch (NullPointerException | ClassCastException e) {
-                        break;
-                    }
+                    final List<Network> underlying = (List<Network>) arg.second;
                     final Network[] oldUnderlying = nai.declaredUnderlyingNetworks;
                     nai.declaredUnderlyingNetworks = (underlying != null)
                             ? underlying.toArray(new Network[0]) : null;
@@ -2897,6 +2852,7 @@
                         updateCapabilitiesForNetwork(nai);
                         notifyIfacesChangedForNetworkStats();
                     }
+                    break;
                 }
             }
         }
@@ -3458,6 +3414,8 @@
         // of rematchAllNetworksAndRequests
         notifyNetworkCallbacks(nai, ConnectivityManager.CALLBACK_LOST);
         mKeepaliveTracker.handleStopAllKeepalives(nai, SocketKeepalive.ERROR_INVALID_NETWORK);
+
+        mQosCallbackTracker.handleNetworkReleased(nai.network);
         for (String iface : nai.linkProperties.getAllInterfaceNames()) {
             // Disable wakeup packet monitoring for each interface.
             wakeupModifyInterface(iface, nai.networkCapabilities, false);
@@ -3470,6 +3428,7 @@
             // available until we've told netd to delete it below.
             mNetworkForNetId.remove(nai.network.getNetId());
         }
+        propagateUnderlyingNetworkCapabilities(nai.network);
         // Remove all previously satisfied requests.
         for (int i = 0; i < nai.numNetworkRequests(); i++) {
             NetworkRequest request = nai.requestAt(i);
@@ -3482,10 +3441,12 @@
             }
         }
         nai.clearLingerState();
-        propagateUnderlyingNetworkCapabilities(nai.network);
+        // TODO: this loop, and the mLegacyTypeTracker.remove just below it, seem redundant given
+        // there's a full rematch right after. Currently, deleting it breaks tests that check for
+        // the default network disconnecting. Find out why, fix the rematch code, and delete this.
         if (nai.isSatisfyingRequest(mDefaultRequest.requestId)) {
             mDefaultNetworkNai = null;
-            updateDataActivityTracking(null /* newNetwork */, nai);
+            mNetworkActivityTracker.updateDataActivityTracking(null /* newNetwork */, nai);
             notifyLockdownVpn(nai);
             ensureNetworkTransitionWakelock(nai.toShortString());
         }
@@ -3724,7 +3685,7 @@
         nri.unlinkDeathRecipient();
         mNetworkRequests.remove(nri.request);
 
-        decrementNetworkRequestPerUidCount(nri);
+        mNetworkRequestCounter.decrementCount(nri.mUid);
 
         mNetworkRequestInfoLogs.log("RELEASE " + nri);
         if (nri.request.isRequest()) {
@@ -3797,19 +3758,6 @@
         }
     }
 
-    private void decrementNetworkRequestPerUidCount(final NetworkRequestInfo nri) {
-        synchronized (mUidToNetworkRequestCount) {
-            final int requests = mUidToNetworkRequestCount.get(nri.mUid, 0);
-            if (requests < 1) {
-                Log.wtf(TAG, "BUG: too small request count " + requests + " for UID " + nri.mUid);
-            } else if (requests == 1) {
-                mUidToNetworkRequestCount.removeAt(mUidToNetworkRequestCount.indexOfKey(nri.mUid));
-            } else {
-                mUidToNetworkRequestCount.put(nri.mUid, requests - 1);
-            }
-        }
-    }
-
     @Override
     public void setAcceptUnvalidated(Network network, boolean accept, boolean always) {
         enforceNetworkStackSettingsOrSetup();
@@ -4636,6 +4584,10 @@
         Log.w(TAG, s);
     }
 
+    private static void logwtf(String s) {
+        Log.wtf(TAG, s);
+    }
+
     private static void loge(String s) {
         Log.e(TAG, s);
     }
@@ -4993,16 +4945,23 @@
         mVpnBlockedUidRanges = newVpnBlockedUidRanges;
     }
 
+    private boolean isLockdownVpnEnabled() {
+        return mKeyStore.contains(Credentials.LOCKDOWN_VPN);
+    }
+
     @Override
     public boolean updateLockdownVpn() {
-        if (mDeps.getCallingUid() != Process.SYSTEM_UID) {
-            logw("Lockdown VPN only available to AID_SYSTEM");
+        // Allow the system UID for the system server and for Settings.
+        // Also, for unit tests, allow the process that ConnectivityService is running in.
+        if (mDeps.getCallingUid() != Process.SYSTEM_UID
+                && Binder.getCallingPid() != Process.myPid()) {
+            logw("Lockdown VPN only available to system process or AID_SYSTEM");
             return false;
         }
 
         synchronized (mVpns) {
             // Tear down existing lockdown if profile was removed
-            mLockdownEnabled = LockdownVpnTracker.isEnabled();
+            mLockdownEnabled = isLockdownVpnEnabled();
             if (mLockdownEnabled) {
                 byte[] profileTag = mKeyStore.get(Credentials.LOCKDOWN_VPN);
                 if (profileTag == null) {
@@ -5023,7 +4982,8 @@
                     logw("VPN for user " + user + " not ready yet. Skipping lockdown");
                     return false;
                 }
-                setLockdownTracker(new LockdownVpnTracker(mContext, this, mHandler, vpn, profile));
+                setLockdownTracker(
+                        new LockdownVpnTracker(mContext, this, mHandler, mKeyStore, vpn,  profile));
             } else {
                 setLockdownTracker(null);
             }
@@ -5111,7 +5071,7 @@
 
         synchronized (mVpns) {
             // Can't set always-on VPN if legacy VPN is already in lockdown mode.
-            if (LockdownVpnTracker.isEnabled()) {
+            if (isLockdownVpnEnabled()) {
                 return false;
             }
 
@@ -5217,7 +5177,7 @@
             }
             userVpn = new Vpn(mHandler.getLooper(), mContext, mNMS, mNetd, userId, mKeyStore);
             mVpns.put(userId, userVpn);
-            if (mUserManager.getUserInfo(userId).isPrimary() && LockdownVpnTracker.isEnabled()) {
+            if (mUserManager.getUserInfo(userId).isPrimary() && isLockdownVpnEnabled()) {
                 updateLockdownVpn();
             }
         }
@@ -5301,7 +5261,7 @@
     private void onUserUnlocked(int userId) {
         synchronized (mVpns) {
             // User present may be sent because of an unlock, which might mean an unlocked keystore.
-            if (mUserManager.getUserInfo(userId).isPrimary() && LockdownVpnTracker.isEnabled()) {
+            if (mUserManager.getUserInfo(userId).isPrimary() && isLockdownVpnEnabled()) {
                 updateLockdownVpn();
             } else {
                 startAlwaysOnVpn(userId);
@@ -5370,11 +5330,6 @@
     private final HashMap<Messenger, NetworkProviderInfo> mNetworkProviderInfos = new HashMap<>();
     private final HashMap<NetworkRequest, NetworkRequestInfo> mNetworkRequests = new HashMap<>();
 
-    private static final int MAX_NETWORK_REQUESTS_PER_UID = 100;
-    // Map from UID to number of NetworkRequests that UID has filed.
-    @GuardedBy("mUidToNetworkRequestCount")
-    private final SparseIntArray mUidToNetworkRequestCount = new SparseIntArray();
-
     private static class NetworkProviderInfo {
         public final String name;
         public final Messenger messenger;
@@ -5488,7 +5443,7 @@
             mBinder = null;
             mPid = getCallingPid();
             mUid = mDeps.getCallingUid();
-            enforceRequestCountLimit();
+            mNetworkRequestCounter.incrementCountOrThrow(mUid);
         }
 
         NetworkRequestInfo(Messenger m, NetworkRequest r, IBinder binder) {
@@ -5501,7 +5456,7 @@
             mPid = getCallingPid();
             mUid = mDeps.getCallingUid();
             mPendingIntent = null;
-            enforceRequestCountLimit();
+            mNetworkRequestCounter.incrementCountOrThrow(mUid);
 
             try {
                 mBinder.linkToDeath(this, 0);
@@ -5538,17 +5493,6 @@
             return null;
         }
 
-        private void enforceRequestCountLimit() {
-            synchronized (mUidToNetworkRequestCount) {
-                int networkRequests = mUidToNetworkRequestCount.get(mUid, 0) + 1;
-                if (networkRequests >= MAX_NETWORK_REQUESTS_PER_UID) {
-                    throw new ServiceSpecificException(
-                            ConnectivityManager.Errors.TOO_MANY_REQUESTS);
-                }
-                mUidToNetworkRequestCount.put(mUid, networkRequests);
-            }
-        }
-
         void unlinkDeathRecipient() {
             if (mBinder != null) {
                 mBinder.unlinkToDeath(this, 0);
@@ -5770,9 +5714,14 @@
             // Policy already enforced.
             return;
         }
-        if (mPolicyManagerInternal.isUidRestrictedOnMeteredNetworks(uid)) {
-            // If UID is restricted, don't allow them to bring up metered APNs.
-            networkCapabilities.addCapability(NET_CAPABILITY_NOT_METERED);
+        final long ident = Binder.clearCallingIdentity();
+        try {
+            if (mPolicyManager.isUidRestrictedOnMeteredNetworks(uid)) {
+                // If UID is restricted, don't allow them to bring up metered APNs.
+                networkCapabilities.addCapability(NET_CAPABILITY_NOT_METERED);
+            }
+        } finally {
+            Binder.restoreCallingIdentity(ident);
         }
     }
 
@@ -6068,6 +6017,10 @@
     public Network registerNetworkAgent(INetworkAgent na, NetworkInfo networkInfo,
             LinkProperties linkProperties, NetworkCapabilities networkCapabilities,
             int currentScore, NetworkAgentConfig networkAgentConfig, int providerId) {
+        Objects.requireNonNull(networkInfo, "networkInfo must not be null");
+        Objects.requireNonNull(linkProperties, "linkProperties must not be null");
+        Objects.requireNonNull(networkCapabilities, "networkCapabilities must not be null");
+        Objects.requireNonNull(networkAgentConfig, "networkAgentConfig must not be null");
         if (networkCapabilities.hasTransport(TRANSPORT_TEST)) {
             enforceAnyPermissionOf(Manifest.permission.MANAGE_TEST_NETWORKS);
         } else {
@@ -6103,7 +6056,7 @@
         final NetworkAgentInfo nai = new NetworkAgentInfo(na,
                 new Network(mNetIdManager.reserveNetId()), new NetworkInfo(networkInfo), lp, nc,
                 currentScore, mContext, mTrackerHandler, new NetworkAgentConfig(networkAgentConfig),
-                this, mNetd, mDnsResolver, mNMS, providerId, uid);
+                this, mNetd, mDnsResolver, mNMS, providerId, uid, mQosCallbackTracker);
 
         // Make sure the LinkProperties and NetworkCapabilities reflect what the agent info says.
         processCapabilitiesFromAgent(nai, nc);
@@ -6606,7 +6559,7 @@
         }
 
         // Don't modify caller's NetworkCapabilities.
-        NetworkCapabilities newNc = new NetworkCapabilities(nc);
+        final NetworkCapabilities newNc = new NetworkCapabilities(nc);
         if (nai.lastValidated) {
             newNc.addCapability(NET_CAPABILITY_VALIDATED);
         } else {
@@ -6694,26 +6647,21 @@
             notifyNetworkCallbacks(nai, ConnectivityManager.CALLBACK_CAP_CHANGED);
         }
 
-        // TODO : static analysis indicates that prevNc can't be null here (getAndSetNetworkCaps
-        // never returns null), so mark the relevant members and functions in nai as @NonNull and
-        // remove this test
-        if (prevNc != null) {
-            final boolean oldMetered = prevNc.isMetered();
-            final boolean newMetered = newNc.isMetered();
-            final boolean meteredChanged = oldMetered != newMetered;
+        final boolean oldMetered = prevNc.isMetered();
+        final boolean newMetered = newNc.isMetered();
+        final boolean meteredChanged = oldMetered != newMetered;
 
-            if (meteredChanged) {
-                maybeNotifyNetworkBlocked(nai, oldMetered, newMetered, mRestrictBackground,
-                        mRestrictBackground, mVpnBlockedUidRanges, mVpnBlockedUidRanges);
-            }
+        if (meteredChanged) {
+            maybeNotifyNetworkBlocked(nai, oldMetered, newMetered, mRestrictBackground,
+                    mRestrictBackground, mVpnBlockedUidRanges, mVpnBlockedUidRanges);
+        }
 
-            final boolean roamingChanged = prevNc.hasCapability(NET_CAPABILITY_NOT_ROAMING) !=
-                    newNc.hasCapability(NET_CAPABILITY_NOT_ROAMING);
+        final boolean roamingChanged = prevNc.hasCapability(NET_CAPABILITY_NOT_ROAMING)
+                != newNc.hasCapability(NET_CAPABILITY_NOT_ROAMING);
 
-            // Report changes that are interesting for network statistics tracking.
-            if (meteredChanged || roamingChanged) {
-                notifyIfacesChangedForNetworkStats();
-            }
+        // Report changes that are interesting for network statistics tracking.
+        if (meteredChanged || roamingChanged) {
+            notifyIfacesChangedForNetworkStats();
         }
 
         // This network might have been underlying another network. Propagate its capabilities.
@@ -7308,7 +7256,8 @@
             if (oldDefaultNetwork != null) {
                 mLingerMonitor.noteLingerDefaultNetwork(oldDefaultNetwork, newDefaultNetwork);
             }
-            updateDataActivityTracking(newDefaultNetwork, oldDefaultNetwork);
+            mNetworkActivityTracker.updateDataActivityTracking(
+                    newDefaultNetwork, oldDefaultNetwork);
             // Notify system services of the new default.
             makeDefault(newDefaultNetwork);
 
@@ -7588,10 +7537,6 @@
         if (!networkAgent.everConnected && state == NetworkInfo.State.CONNECTED) {
             networkAgent.everConnected = true;
 
-            if (networkAgent.linkProperties == null) {
-                Log.wtf(TAG, networkAgent.toShortString() + " connected with null LinkProperties");
-            }
-
             // NetworkCapabilities need to be set before sending the private DNS config to
             // NetworkMonitor, otherwise NetworkMonitor cannot determine if validation is required.
             networkAgent.getAndSetNetworkCapabilities(networkAgent.networkCapabilities);
@@ -7910,10 +7855,11 @@
     }
 
     @Override
-    public void startNattKeepaliveWithFd(Network network, FileDescriptor fd, int resourceId,
+    public void startNattKeepaliveWithFd(Network network, ParcelFileDescriptor pfd, int resourceId,
             int intervalSeconds, ISocketKeepaliveCallback cb, String srcAddr,
             String dstAddr) {
         try {
+            final FileDescriptor fd = pfd.getFileDescriptor();
             mKeepaliveTracker.startNattKeepalive(
                     getNetworkAgentInfoForNetwork(network), fd, resourceId,
                     intervalSeconds, cb,
@@ -7921,24 +7867,25 @@
         } finally {
             // FileDescriptors coming from AIDL calls must be manually closed to prevent leaks.
             // startNattKeepalive calls Os.dup(fd) before returning, so we can close immediately.
-            if (fd != null && Binder.getCallingPid() != Process.myPid()) {
-                IoUtils.closeQuietly(fd);
+            if (pfd != null && Binder.getCallingPid() != Process.myPid()) {
+                IoUtils.closeQuietly(pfd);
             }
         }
     }
 
     @Override
-    public void startTcpKeepalive(Network network, FileDescriptor fd, int intervalSeconds,
+    public void startTcpKeepalive(Network network, ParcelFileDescriptor pfd, int intervalSeconds,
             ISocketKeepaliveCallback cb) {
         try {
             enforceKeepalivePermission();
+            final FileDescriptor fd = pfd.getFileDescriptor();
             mKeepaliveTracker.startTcpKeepalive(
                     getNetworkAgentInfoForNetwork(network), fd, intervalSeconds, cb);
         } finally {
             // FileDescriptors coming from AIDL calls must be manually closed to prevent leaks.
             // startTcpKeepalive calls Os.dup(fd) before returning, so we can close immediately.
-            if (fd != null && Binder.getCallingPid() != Process.myPid()) {
-                IoUtils.closeQuietly(fd);
+            if (pfd != null && Binder.getCallingPid() != Process.myPid()) {
+                IoUtils.closeQuietly(pfd);
             }
         }
     }
@@ -8389,7 +8336,7 @@
             // Decrement the reference count for this NetworkRequestInfo. The reference count is
             // incremented when the NetworkRequestInfo is created as part of
             // enforceRequestCountLimit().
-            decrementNetworkRequestPerUidCount(nri);
+            mNetworkRequestCounter.decrementCount(nri.mUid);
             return;
         }
 
@@ -8455,7 +8402,7 @@
         // Decrement the reference count for this NetworkRequestInfo. The reference count is
         // incremented when the NetworkRequestInfo is created as part of
         // enforceRequestCountLimit().
-        decrementNetworkRequestPerUidCount(nri);
+        mNetworkRequestCounter.decrementCount(nri.mUid);
 
         iCb.unlinkToDeath(cbInfo, 0);
     }
@@ -8664,4 +8611,194 @@
 
         notifyDataStallSuspected(p, network.getNetId());
     }
+
+    private final LegacyNetworkActivityTracker mNetworkActivityTracker;
+
+    /**
+     * Class used for updating network activity tracking with netd and notify network activity
+     * changes.
+     */
+    private static final class LegacyNetworkActivityTracker {
+        private final Context mContext;
+        private final INetworkManagementService mNMS;
+
+        LegacyNetworkActivityTracker(@NonNull Context context,
+                @NonNull INetworkManagementService nms) {
+            mContext = context;
+            mNMS = nms;
+            try {
+                mNMS.registerObserver(mDataActivityObserver);
+            } catch (RemoteException e) {
+                loge("Error registering observer :" + e);
+            }
+        }
+
+        // TODO: Migrate away the dependency with INetworkManagementEventObserver.
+        private final INetworkManagementEventObserver mDataActivityObserver =
+                new BaseNetworkObserver() {
+                    @Override
+                    public void interfaceClassDataActivityChanged(int transportType, boolean active,
+                            long tsNanos, int uid) {
+                        sendDataActivityBroadcast(transportTypeToLegacyType(transportType), active,
+                                tsNanos);
+                    }
+                };
+
+        // This is deprecated and only to support legacy use cases.
+        private int transportTypeToLegacyType(int type) {
+            switch (type) {
+                case NetworkCapabilities.TRANSPORT_CELLULAR:
+                    return ConnectivityManager.TYPE_MOBILE;
+                case NetworkCapabilities.TRANSPORT_WIFI:
+                    return ConnectivityManager.TYPE_WIFI;
+                case NetworkCapabilities.TRANSPORT_BLUETOOTH:
+                    return ConnectivityManager.TYPE_BLUETOOTH;
+                case NetworkCapabilities.TRANSPORT_ETHERNET:
+                    return ConnectivityManager.TYPE_ETHERNET;
+                default:
+                    loge("Unexpected transport in transportTypeToLegacyType: " + type);
+            }
+            return ConnectivityManager.TYPE_NONE;
+        }
+
+        public void sendDataActivityBroadcast(int deviceType, boolean active, long tsNanos) {
+            final Intent intent = new Intent(ConnectivityManager.ACTION_DATA_ACTIVITY_CHANGE);
+            intent.putExtra(ConnectivityManager.EXTRA_DEVICE_TYPE, deviceType);
+            intent.putExtra(ConnectivityManager.EXTRA_IS_ACTIVE, active);
+            intent.putExtra(ConnectivityManager.EXTRA_REALTIME_NS, tsNanos);
+            final long ident = Binder.clearCallingIdentity();
+            try {
+                mContext.sendOrderedBroadcastAsUser(intent, UserHandle.ALL,
+                        RECEIVE_DATA_ACTIVITY_CHANGE,
+                        null /* resultReceiver */,
+                        null /* scheduler */,
+                        0 /* initialCode */,
+                        null /* initialData */,
+                        null /* initialExtra */);
+            } finally {
+                Binder.restoreCallingIdentity(ident);
+            }
+        }
+
+        /**
+         * Setup data activity tracking for the given network.
+         *
+         * Every {@code setupDataActivityTracking} should be paired with a
+         * {@link #removeDataActivityTracking} for cleanup.
+         */
+        private void setupDataActivityTracking(NetworkAgentInfo networkAgent) {
+            final String iface = networkAgent.linkProperties.getInterfaceName();
+
+            final int timeout;
+            final int type;
+
+            if (networkAgent.networkCapabilities.hasTransport(
+                    NetworkCapabilities.TRANSPORT_CELLULAR)) {
+                timeout = Settings.Global.getInt(mContext.getContentResolver(),
+                        Settings.Global.DATA_ACTIVITY_TIMEOUT_MOBILE,
+                        10);
+                type = NetworkCapabilities.TRANSPORT_CELLULAR;
+            } else if (networkAgent.networkCapabilities.hasTransport(
+                    NetworkCapabilities.TRANSPORT_WIFI)) {
+                timeout = Settings.Global.getInt(mContext.getContentResolver(),
+                        Settings.Global.DATA_ACTIVITY_TIMEOUT_WIFI,
+                        15);
+                type = NetworkCapabilities.TRANSPORT_WIFI;
+            } else {
+                return; // do not track any other networks
+            }
+
+            if (timeout > 0 && iface != null) {
+                try {
+                    // TODO: Access INetd directly instead of NMS
+                    mNMS.addIdleTimer(iface, timeout, type);
+                } catch (Exception e) {
+                    // You shall not crash!
+                    loge("Exception in setupDataActivityTracking " + e);
+                }
+            }
+        }
+
+        /**
+         * Remove data activity tracking when network disconnects.
+         */
+        private void removeDataActivityTracking(NetworkAgentInfo networkAgent) {
+            final String iface = networkAgent.linkProperties.getInterfaceName();
+            final NetworkCapabilities caps = networkAgent.networkCapabilities;
+
+            if (iface != null && (caps.hasTransport(NetworkCapabilities.TRANSPORT_CELLULAR)
+                    || caps.hasTransport(NetworkCapabilities.TRANSPORT_WIFI))) {
+                try {
+                    // the call fails silently if no idle timer setup for this interface
+                    // TODO: Access INetd directly instead of NMS
+                    mNMS.removeIdleTimer(iface);
+                } catch (Exception e) {
+                    // You shall not crash!
+                    loge("Exception in removeDataActivityTracking " + e);
+                }
+            }
+        }
+
+        /**
+         * Update data activity tracking when network state is updated.
+         */
+        public void updateDataActivityTracking(NetworkAgentInfo newNetwork,
+                NetworkAgentInfo oldNetwork) {
+            if (newNetwork != null) {
+                setupDataActivityTracking(newNetwork);
+            }
+            if (oldNetwork != null) {
+                removeDataActivityTracking(oldNetwork);
+            }
+        }
+    }
+    /**
+     * Registers {@link QosSocketFilter} with {@link IQosCallback}.
+     *
+     * @param socketInfo the socket information
+     * @param callback the callback to register
+     */
+    @Override
+    public void registerQosSocketCallback(@NonNull final QosSocketInfo socketInfo,
+            @NonNull final IQosCallback callback) {
+        final NetworkAgentInfo nai = getNetworkAgentInfoForNetwork(socketInfo.getNetwork());
+        if (nai == null || nai.networkCapabilities == null) {
+            try {
+                callback.onError(QosCallbackException.EX_TYPE_FILTER_NETWORK_RELEASED);
+            } catch (final RemoteException ex) {
+                loge("registerQosCallbackInternal: RemoteException", ex);
+            }
+            return;
+        }
+        registerQosCallbackInternal(new QosSocketFilter(socketInfo), callback, nai);
+    }
+
+    /**
+     * Register a {@link IQosCallback} with base {@link QosFilter}.
+     *
+     * @param filter the filter to register
+     * @param callback the callback to register
+     * @param nai the agent information related to the filter's network
+     */
+    @VisibleForTesting
+    public void registerQosCallbackInternal(@NonNull final QosFilter filter,
+            @NonNull final IQosCallback callback, @NonNull final NetworkAgentInfo nai) {
+        if (filter == null) throw new IllegalArgumentException("filter must be non-null");
+        if (callback == null) throw new IllegalArgumentException("callback must be non-null");
+
+        if (!nai.networkCapabilities.hasCapability(NET_CAPABILITY_NOT_RESTRICTED)) {
+            enforceConnectivityRestrictedNetworksPermission();
+        }
+        mQosCallbackTracker.registerCallback(callback, filter, nai);
+    }
+
+    /**
+     * Unregisters the given callback.
+     *
+     * @param callback the callback to unregister
+     */
+    @Override
+    public void unregisterQosCallback(@NonNull final IQosCallback callback) {
+        mQosCallbackTracker.unregisterCallback(callback);
+    }
 }
diff --git a/services/core/java/com/android/server/connectivity/Nat464Xlat.java b/services/core/java/com/android/server/connectivity/Nat464Xlat.java
index c1b1b6a..952193b 100644
--- a/services/core/java/com/android/server/connectivity/Nat464Xlat.java
+++ b/services/core/java/com/android/server/connectivity/Nat464Xlat.java
@@ -246,11 +246,6 @@
             return;
         }
 
-        if (mNetwork.linkProperties == null) {
-            Log.e(TAG, "startClat: Can't start clat with null LinkProperties");
-            return;
-        }
-
         String baseIface = mNetwork.linkProperties.getInterfaceName();
         if (baseIface == null) {
             Log.e(TAG, "startClat: Can't start clat on null interface");
diff --git a/services/core/java/com/android/server/connectivity/NetworkAgentInfo.java b/services/core/java/com/android/server/connectivity/NetworkAgentInfo.java
index b0a73f1..ab0360b 100644
--- a/services/core/java/com/android/server/connectivity/NetworkAgentInfo.java
+++ b/services/core/java/com/android/server/connectivity/NetworkAgentInfo.java
@@ -36,13 +36,17 @@
 import android.net.NetworkMonitorManager;
 import android.net.NetworkRequest;
 import android.net.NetworkState;
+import android.net.QosCallbackException;
+import android.net.QosFilter;
+import android.net.QosFilterParcelable;
+import android.net.QosSession;
 import android.net.TcpKeepalivePacketData;
-import android.os.Bundle;
 import android.os.Handler;
 import android.os.IBinder;
 import android.os.INetworkManagementService;
 import android.os.RemoteException;
 import android.os.SystemClock;
+import android.telephony.data.EpsBearerQosSessionAttributes;
 import android.util.Log;
 import android.util.Pair;
 import android.util.SparseArray;
@@ -53,7 +57,6 @@
 import com.android.server.ConnectivityService;
 
 import java.io.PrintWriter;
-import java.util.ArrayList;
 import java.util.List;
 import java.util.NoSuchElementException;
 import java.util.Objects;
@@ -136,12 +139,12 @@
     // This Network object should always be used if possible, so as to encourage reuse of the
     // enclosed socket factory and connection pool.  Avoid creating other Network objects.
     // This Network object is always valid.
-    public final Network network;
-    public LinkProperties linkProperties;
+    @NonNull public final Network network;
+    @NonNull public LinkProperties linkProperties;
     // This should only be modified by ConnectivityService, via setNetworkCapabilities().
     // TODO: make this private with a getter.
-    public NetworkCapabilities networkCapabilities;
-    public final NetworkAgentConfig networkAgentConfig;
+    @NonNull public NetworkCapabilities networkCapabilities;
+    @NonNull public final NetworkAgentConfig networkAgentConfig;
 
     // Underlying networks declared by the agent. Only set if supportsUnderlyingNetworks is true.
     // The networks in this list might be declared by a VPN app using setUnderlyingNetworks and are
@@ -323,12 +326,20 @@
     private final ConnectivityService mConnService;
     private final Context mContext;
     private final Handler mHandler;
+    private final QosCallbackTracker mQosCallbackTracker;
 
     public NetworkAgentInfo(INetworkAgent na, Network net, NetworkInfo info,
             LinkProperties lp, NetworkCapabilities nc, int score, Context context,
             Handler handler, NetworkAgentConfig config, ConnectivityService connService, INetd netd,
             IDnsResolver dnsResolver, INetworkManagementService nms, int factorySerialNumber,
-            int creatorUid) {
+            int creatorUid, QosCallbackTracker qosCallbackTracker) {
+        Objects.requireNonNull(net);
+        Objects.requireNonNull(info);
+        Objects.requireNonNull(lp);
+        Objects.requireNonNull(nc);
+        Objects.requireNonNull(context);
+        Objects.requireNonNull(config);
+        Objects.requireNonNull(qosCallbackTracker);
         networkAgent = na;
         network = net;
         networkInfo = info;
@@ -342,6 +353,7 @@
         networkAgentConfig = config;
         this.factorySerialNumber = factorySerialNumber;
         this.creatorUid = creatorUid;
+        mQosCallbackTracker = qosCallbackTracker;
     }
 
     private class AgentDeathMonitor implements IBinder.DeathRecipient {
@@ -527,6 +539,31 @@
         }
     }
 
+    /**
+     * Notify the NetworkAgent that the qos filter should be registered against the given qos
+     * callback id.
+     */
+    public void onQosFilterCallbackRegistered(final int qosCallbackId,
+            final QosFilter qosFilter) {
+        try {
+            networkAgent.onQosFilterCallbackRegistered(qosCallbackId,
+                    new QosFilterParcelable(qosFilter));
+        } catch (final RemoteException e) {
+            Log.e(TAG, "Error registering a qos callback id against a qos filter", e);
+        }
+    }
+
+    /**
+     * Notify the NetworkAgent that the given qos callback id should be unregistered.
+     */
+    public void onQosCallbackUnregistered(final int qosCallbackId) {
+        try {
+            networkAgent.onQosCallbackUnregistered(qosCallbackId);
+        } catch (RemoteException e) {
+            Log.e(TAG, "Error unregistering a qos callback id", e);
+        }
+    }
+
     // TODO: consider moving out of NetworkAgentInfo into its own class
     private class NetworkAgentMessageHandler extends INetworkAgentRegistry.Stub {
         private final Handler mHandler;
@@ -536,19 +573,22 @@
         }
 
         @Override
-        public void sendNetworkCapabilities(NetworkCapabilities nc) {
+        public void sendNetworkCapabilities(@NonNull NetworkCapabilities nc) {
+            Objects.requireNonNull(nc);
             mHandler.obtainMessage(NetworkAgent.EVENT_NETWORK_CAPABILITIES_CHANGED,
                     new Pair<>(NetworkAgentInfo.this, nc)).sendToTarget();
         }
 
         @Override
-        public void sendLinkProperties(LinkProperties lp) {
+        public void sendLinkProperties(@NonNull LinkProperties lp) {
+            Objects.requireNonNull(lp);
             mHandler.obtainMessage(NetworkAgent.EVENT_NETWORK_PROPERTIES_CHANGED,
                     new Pair<>(NetworkAgentInfo.this, lp)).sendToTarget();
         }
 
         @Override
-        public void sendNetworkInfo(NetworkInfo info) {
+        public void sendNetworkInfo(@NonNull NetworkInfo info) {
+            Objects.requireNonNull(info);
             mHandler.obtainMessage(NetworkAgent.EVENT_NETWORK_INFO_CHANGED,
                     new Pair<>(NetworkAgentInfo.this, info)).sendToTarget();
         }
@@ -574,16 +614,25 @@
 
         @Override
         public void sendUnderlyingNetworks(@Nullable List<Network> networks) {
-            final Bundle args = new Bundle();
-            if (networks instanceof ArrayList<?>) {
-                args.putParcelableArrayList(NetworkAgent.UNDERLYING_NETWORKS_KEY,
-                        (ArrayList<Network>) networks);
-            } else {
-                args.putParcelableArrayList(NetworkAgent.UNDERLYING_NETWORKS_KEY,
-                        networks == null ? null : new ArrayList<>(networks));
-            }
             mHandler.obtainMessage(NetworkAgent.EVENT_UNDERLYING_NETWORKS_CHANGED,
-                    new Pair<>(NetworkAgentInfo.this, args)).sendToTarget();
+                    new Pair<>(NetworkAgentInfo.this, networks)).sendToTarget();
+        }
+
+        @Override
+        public void sendEpsQosSessionAvailable(final int qosCallbackId, final QosSession session,
+                final EpsBearerQosSessionAttributes attributes) {
+            mQosCallbackTracker.sendEventQosSessionAvailable(qosCallbackId, session, attributes);
+        }
+
+        @Override
+        public void sendQosSessionLost(final int qosCallbackId, final QosSession session) {
+            mQosCallbackTracker.sendEventQosSessionLost(qosCallbackId, session);
+        }
+
+        @Override
+        public void sendQosCallbackError(final int qosCallbackId,
+                @QosCallbackException.ExceptionType final int exceptionType) {
+            mQosCallbackTracker.sendEventQosCallbackError(qosCallbackId, exceptionType);
         }
     }
 
@@ -603,7 +652,7 @@
      *
      * @return the old capabilities of this network.
      */
-    public synchronized NetworkCapabilities getAndSetNetworkCapabilities(
+    @NonNull public synchronized NetworkCapabilities getAndSetNetworkCapabilities(
             @NonNull final NetworkCapabilities nc) {
         final NetworkCapabilities oldNc = networkCapabilities;
         networkCapabilities = nc;
diff --git a/services/core/java/com/android/server/connectivity/QosCallbackAgentConnection.java b/services/core/java/com/android/server/connectivity/QosCallbackAgentConnection.java
new file mode 100644
index 0000000..816bf2b
--- /dev/null
+++ b/services/core/java/com/android/server/connectivity/QosCallbackAgentConnection.java
@@ -0,0 +1,192 @@
+/*
+ * Copyright (C) 2020 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 com.android.server.connectivity;
+
+import static android.net.QosCallbackException.EX_TYPE_FILTER_NONE;
+
+import android.annotation.NonNull;
+import android.net.IQosCallback;
+import android.net.Network;
+import android.net.QosCallbackException;
+import android.net.QosFilter;
+import android.net.QosSession;
+import android.os.IBinder;
+import android.os.RemoteException;
+import android.telephony.data.EpsBearerQosSessionAttributes;
+import android.util.Slog;
+
+import java.util.Objects;
+
+/**
+ * Wraps callback related information and sends messages between network agent and the application.
+ * <p/>
+ * This is a satellite class of {@link com.android.server.ConnectivityService} and not meant
+ * to be used in other contexts.
+ *
+ * @hide
+ */
+class QosCallbackAgentConnection implements IBinder.DeathRecipient {
+    private static final String TAG = QosCallbackAgentConnection.class.getSimpleName();
+    private static final boolean DBG = false;
+
+    private final int mAgentCallbackId;
+    @NonNull private final QosCallbackTracker mQosCallbackTracker;
+    @NonNull private final IQosCallback mCallback;
+    @NonNull private final IBinder mBinder;
+    @NonNull private final QosFilter mFilter;
+    @NonNull private final NetworkAgentInfo mNetworkAgentInfo;
+
+    private final int mUid;
+
+    /**
+     * Gets the uid
+     * @return uid
+     */
+    int getUid() {
+        return mUid;
+    }
+
+    /**
+     * Gets the binder
+     * @return binder
+     */
+    @NonNull
+    IBinder getBinder() {
+        return mBinder;
+    }
+
+    /**
+     * Gets the callback id
+     *
+     * @return callback id
+     */
+    int getAgentCallbackId() {
+        return mAgentCallbackId;
+    }
+
+    /**
+     * Gets the network tied to the callback of this connection
+     *
+     * @return network
+     */
+    @NonNull
+    Network getNetwork() {
+        return mFilter.getNetwork();
+    }
+
+    QosCallbackAgentConnection(@NonNull final QosCallbackTracker qosCallbackTracker,
+            final int agentCallbackId,
+            @NonNull final IQosCallback callback,
+            @NonNull final QosFilter filter,
+            final int uid,
+            @NonNull final NetworkAgentInfo networkAgentInfo) {
+        Objects.requireNonNull(qosCallbackTracker, "qosCallbackTracker must be non-null");
+        Objects.requireNonNull(callback, "callback must be non-null");
+        Objects.requireNonNull(filter, "filter must be non-null");
+        Objects.requireNonNull(networkAgentInfo, "networkAgentInfo must be non-null");
+
+        mQosCallbackTracker = qosCallbackTracker;
+        mAgentCallbackId = agentCallbackId;
+        mCallback = callback;
+        mFilter = filter;
+        mUid = uid;
+        mBinder = mCallback.asBinder();
+        mNetworkAgentInfo = networkAgentInfo;
+    }
+
+    @Override
+    public void binderDied() {
+        logw("binderDied: binder died with callback id: " + mAgentCallbackId);
+        mQosCallbackTracker.unregisterCallback(mCallback);
+    }
+
+    void unlinkToDeathRecipient() {
+        mBinder.unlinkToDeath(this, 0);
+    }
+
+    // Returns false if the NetworkAgent was never notified.
+    boolean sendCmdRegisterCallback() {
+        final int exceptionType = mFilter.validate();
+        if (exceptionType != EX_TYPE_FILTER_NONE) {
+            try {
+                if (DBG) log("sendCmdRegisterCallback: filter validation failed");
+                mCallback.onError(exceptionType);
+            } catch (final RemoteException e) {
+                loge("sendCmdRegisterCallback:", e);
+            }
+            return false;
+        }
+
+        try {
+            mBinder.linkToDeath(this, 0);
+        } catch (final RemoteException e) {
+            loge("failed linking to death recipient", e);
+            return false;
+        }
+        mNetworkAgentInfo.onQosFilterCallbackRegistered(mAgentCallbackId, mFilter);
+        return true;
+    }
+
+    void sendCmdUnregisterCallback() {
+        if (DBG) log("sendCmdUnregisterCallback: unregistering");
+        mNetworkAgentInfo.onQosCallbackUnregistered(mAgentCallbackId);
+    }
+
+    void sendEventQosSessionAvailable(final QosSession session,
+            final EpsBearerQosSessionAttributes attributes) {
+        try {
+            if (DBG) log("sendEventQosSessionAvailable: sending...");
+            mCallback.onQosEpsBearerSessionAvailable(session, attributes);
+        } catch (final RemoteException e) {
+            loge("sendEventQosSessionAvailable: remote exception", e);
+        }
+    }
+
+    void sendEventQosSessionLost(@NonNull final QosSession session) {
+        try {
+            if (DBG) log("sendEventQosSessionLost: sending...");
+            mCallback.onQosSessionLost(session);
+        } catch (final RemoteException e) {
+            loge("sendEventQosSessionLost: remote exception", e);
+        }
+    }
+
+    void sendEventQosCallbackError(@QosCallbackException.ExceptionType final int exceptionType) {
+        try {
+            if (DBG) log("sendEventQosCallbackError: sending...");
+            mCallback.onError(exceptionType);
+        } catch (final RemoteException e) {
+            loge("sendEventQosCallbackError: remote exception", e);
+        }
+    }
+
+    private static void log(@NonNull final String msg) {
+        Slog.d(TAG, msg);
+    }
+
+    private static void logw(@NonNull final String msg) {
+        Slog.w(TAG, msg);
+    }
+
+    private static void loge(@NonNull final String msg, final Throwable t) {
+        Slog.e(TAG, msg, t);
+    }
+
+    private static void logwtf(@NonNull final String msg) {
+        Slog.wtf(TAG, msg);
+    }
+}
diff --git a/services/core/java/com/android/server/connectivity/QosCallbackTracker.java b/services/core/java/com/android/server/connectivity/QosCallbackTracker.java
new file mode 100644
index 0000000..87b4c16
--- /dev/null
+++ b/services/core/java/com/android/server/connectivity/QosCallbackTracker.java
@@ -0,0 +1,277 @@
+/*
+ * Copyright (C) 2020 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 com.android.server.connectivity;
+
+import android.annotation.NonNull;
+import android.annotation.Nullable;
+import android.net.IQosCallback;
+import android.net.Network;
+import android.net.QosCallbackException;
+import android.net.QosFilter;
+import android.net.QosSession;
+import android.os.Binder;
+import android.os.Handler;
+import android.os.IBinder;
+import android.telephony.data.EpsBearerQosSessionAttributes;
+import android.util.Slog;
+
+import com.android.internal.util.CollectionUtils;
+import com.android.server.ConnectivityService;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * Tracks qos callbacks and handles the communication between the network agent and application.
+ * <p/>
+ * Any method prefixed by handle must be called from the
+ * {@link com.android.server.ConnectivityService} handler thread.
+ *
+ * @hide
+ */
+public class QosCallbackTracker {
+    private static final String TAG = QosCallbackTracker.class.getSimpleName();
+    private static final boolean DBG = true;
+
+    @NonNull
+    private final Handler mConnectivityServiceHandler;
+
+    @NonNull
+    private final ConnectivityService.PerUidCounter mNetworkRequestCounter;
+
+    /**
+     * Each agent gets a unique callback id that is used to proxy messages back to the original
+     * callback.
+     * <p/>
+     * Note: The fact that this is initialized to 0 is to ensure that the thread running
+     * {@link #handleRegisterCallback(IQosCallback, QosFilter, int, NetworkAgentInfo)} sees the
+     * initialized value. This would not necessarily be the case if the value was initialized to
+     * the non-default value.
+     * <p/>
+     * Note: The term previous does not apply to the first callback id that is assigned.
+     */
+    private int mPreviousAgentCallbackId = 0;
+
+    @NonNull
+    private final List<QosCallbackAgentConnection> mConnections = new ArrayList<>();
+
+    /**
+     *
+     * @param connectivityServiceHandler must be the same handler used with
+     *                {@link com.android.server.ConnectivityService}
+     * @param networkRequestCounter keeps track of the number of open requests under a given
+     *                              uid
+     */
+    public QosCallbackTracker(@NonNull final Handler connectivityServiceHandler,
+            final ConnectivityService.PerUidCounter networkRequestCounter) {
+        mConnectivityServiceHandler = connectivityServiceHandler;
+        mNetworkRequestCounter = networkRequestCounter;
+    }
+
+    /**
+     * Registers the callback with the tracker
+     *
+     * @param callback the callback to register
+     * @param filter the filter being registered alongside the callback
+     */
+    public void registerCallback(@NonNull final IQosCallback callback,
+            @NonNull final QosFilter filter, @NonNull final NetworkAgentInfo networkAgentInfo) {
+        final int uid = Binder.getCallingUid();
+
+        // Enforce that the number of requests under this uid has exceeded the allowed number
+        mNetworkRequestCounter.incrementCountOrThrow(uid);
+
+        mConnectivityServiceHandler.post(
+                () -> handleRegisterCallback(callback, filter, uid, networkAgentInfo));
+    }
+
+    private void handleRegisterCallback(@NonNull final IQosCallback callback,
+            @NonNull final QosFilter filter, final int uid,
+            @NonNull final NetworkAgentInfo networkAgentInfo) {
+        final QosCallbackAgentConnection ac =
+                handleRegisterCallbackInternal(callback, filter, uid, networkAgentInfo);
+        if (ac != null) {
+            if (DBG) log("handleRegisterCallback: added callback " + ac.getAgentCallbackId());
+            mConnections.add(ac);
+        } else {
+            mNetworkRequestCounter.decrementCount(uid);
+        }
+    }
+
+    private QosCallbackAgentConnection handleRegisterCallbackInternal(
+            @NonNull final IQosCallback callback,
+            @NonNull final QosFilter filter, final int uid,
+            @NonNull final NetworkAgentInfo networkAgentInfo) {
+        final IBinder binder = callback.asBinder();
+        if (CollectionUtils.any(mConnections, c -> c.getBinder().equals(binder))) {
+            // A duplicate registration would have only made this far due to a programming error.
+            logwtf("handleRegisterCallback: Callbacks can only be register once.");
+            return null;
+        }
+
+        mPreviousAgentCallbackId = mPreviousAgentCallbackId + 1;
+        final int newCallbackId = mPreviousAgentCallbackId;
+
+        final QosCallbackAgentConnection ac =
+                new QosCallbackAgentConnection(this, newCallbackId, callback,
+                        filter, uid, networkAgentInfo);
+
+        final int exceptionType = filter.validate();
+        if (exceptionType != QosCallbackException.EX_TYPE_FILTER_NONE) {
+            ac.sendEventQosCallbackError(exceptionType);
+            return null;
+        }
+
+        // Only add to the callback maps if the NetworkAgent successfully registered it
+        if (!ac.sendCmdRegisterCallback()) {
+            // There was an issue when registering the agent
+            if (DBG) log("handleRegisterCallback: error sending register callback");
+            mNetworkRequestCounter.decrementCount(uid);
+            return null;
+        }
+        return ac;
+    }
+
+    /**
+     * Unregisters callback
+     * @param callback callback to unregister
+     */
+    public void unregisterCallback(@NonNull final IQosCallback callback) {
+        mConnectivityServiceHandler.post(() -> handleUnregisterCallback(callback.asBinder(), true));
+    }
+
+    private void handleUnregisterCallback(@NonNull final IBinder binder,
+            final boolean sendToNetworkAgent) {
+        final QosCallbackAgentConnection agentConnection =
+                CollectionUtils.find(mConnections, c -> c.getBinder().equals(binder));
+        if (agentConnection == null) {
+            logw("handleUnregisterCallback: agentConnection is null");
+            return;
+        }
+
+        if (DBG) {
+            log("handleUnregisterCallback: unregister "
+                    + agentConnection.getAgentCallbackId());
+        }
+
+        mNetworkRequestCounter.decrementCount(agentConnection.getUid());
+        mConnections.remove(agentConnection);
+
+        if (sendToNetworkAgent) {
+            agentConnection.sendCmdUnregisterCallback();
+        }
+        agentConnection.unlinkToDeathRecipient();
+    }
+
+    /**
+     * Called when the NetworkAgent sends the qos session available event
+     *
+     * @param qosCallbackId the callback id that the qos session is now available to
+     * @param session the qos session that is now available
+     * @param attributes the qos attributes that are now available on the qos session
+     */
+    public void sendEventQosSessionAvailable(final int qosCallbackId,
+            final QosSession session,
+            final EpsBearerQosSessionAttributes attributes) {
+        runOnAgentConnection(qosCallbackId, "sendEventQosSessionAvailable: ",
+                ac -> ac.sendEventQosSessionAvailable(session, attributes));
+    }
+
+    /**
+     * Called when the NetworkAgent sends the qos session lost event
+     *
+     * @param qosCallbackId the callback id that lost the qos session
+     * @param session the corresponding qos session
+     */
+    public void sendEventQosSessionLost(final int qosCallbackId,
+            final QosSession session) {
+        runOnAgentConnection(qosCallbackId, "sendEventQosSessionLost: ",
+                ac -> ac.sendEventQosSessionLost(session));
+    }
+
+    /**
+     * Called when the NetworkAgent sends the qos session on error event
+     *
+     * @param qosCallbackId the callback id that should receive the exception
+     * @param exceptionType the type of exception that caused the callback to error
+     */
+    public void sendEventQosCallbackError(final int qosCallbackId,
+            @QosCallbackException.ExceptionType final int exceptionType) {
+        runOnAgentConnection(qosCallbackId, "sendEventQosCallbackError: ",
+                ac -> {
+                    ac.sendEventQosCallbackError(exceptionType);
+                    handleUnregisterCallback(ac.getBinder(), false);
+                });
+    }
+
+    /**
+     * Unregisters all callbacks associated to this network agent
+     *
+     * Note: Must be called on the connectivity service handler thread
+     *
+     * @param network the network that was released
+     */
+    public void handleNetworkReleased(@Nullable final Network network) {
+        final List<QosCallbackAgentConnection> connections =
+                CollectionUtils.filter(mConnections, ac -> ac.getNetwork().equals(network));
+
+        for (final QosCallbackAgentConnection agentConnection : connections) {
+            agentConnection.sendEventQosCallbackError(
+                    QosCallbackException.EX_TYPE_FILTER_NETWORK_RELEASED);
+
+            // Call unregister workflow w\o sending anything to agent since it is disconnected.
+            handleUnregisterCallback(agentConnection.getBinder(), false);
+        }
+    }
+
+    private interface AgentConnectionAction {
+        void execute(@NonNull QosCallbackAgentConnection agentConnection);
+    }
+
+    @Nullable
+    private void runOnAgentConnection(final int qosCallbackId,
+            @NonNull final String logPrefix,
+            @NonNull final AgentConnectionAction action) {
+        mConnectivityServiceHandler.post(() -> {
+            final QosCallbackAgentConnection ac =
+                    CollectionUtils.find(mConnections,
+                            c -> c.getAgentCallbackId() == qosCallbackId);
+            if (ac == null) {
+                loge(logPrefix + ": " + qosCallbackId + " missing callback id");
+                return;
+            }
+
+            action.execute(ac);
+        });
+    }
+
+    private static void log(final String msg) {
+        Slog.d(TAG, msg);
+    }
+
+    private static void logw(final String msg) {
+        Slog.w(TAG, msg);
+    }
+
+    private static void loge(final String msg) {
+        Slog.e(TAG, msg);
+    }
+
+    private static void logwtf(final String msg) {
+        Slog.wtf(TAG, msg);
+    }
+}
diff --git a/tests/net/common/java/android/net/CaptivePortalDataTest.kt b/tests/net/common/java/android/net/CaptivePortalDataTest.kt
index 2cb16d3..b2bcfeb 100644
--- a/tests/net/common/java/android/net/CaptivePortalDataTest.kt
+++ b/tests/net/common/java/android/net/CaptivePortalDataTest.kt
@@ -58,7 +58,8 @@
 
     @Test
     fun testParcelUnparcel() {
-        assertParcelSane(data, fieldCount = 8)
+        val fieldCount = if (SdkLevel.isAtLeastS()) 8 else 7
+        assertParcelSane(data, fieldCount)
 
         assertParcelingIsLossless(makeBuilder().setUserPortalUrl(null).build())
         assertParcelingIsLossless(makeBuilder().setVenueInfoUrl(null).build())
diff --git a/tests/net/integration/src/com/android/server/net/integrationtests/ConnectivityServiceIntegrationTest.kt b/tests/net/integration/src/com/android/server/net/integrationtests/ConnectivityServiceIntegrationTest.kt
index 8e18751..16c4865 100644
--- a/tests/net/integration/src/com/android/server/net/integrationtests/ConnectivityServiceIntegrationTest.kt
+++ b/tests/net/integration/src/com/android/server/net/integrationtests/ConnectivityServiceIntegrationTest.kt
@@ -46,8 +46,6 @@
 import com.android.server.LocalServices
 import com.android.server.NetworkAgentWrapper
 import com.android.server.TestNetIdManager
-import com.android.server.connectivity.DefaultNetworkMetrics
-import com.android.server.connectivity.IpConnectivityMetrics
 import com.android.server.connectivity.MockableSystemProperties
 import com.android.server.connectivity.ProxyTracker
 import com.android.server.net.NetworkPolicyManagerInternal
@@ -92,10 +90,6 @@
     private lateinit var netd: INetd
     @Mock
     private lateinit var dnsResolver: IDnsResolver
-    @Mock
-    private lateinit var metricsLogger: IpConnectivityMetrics.Logger
-    @Mock
-    private lateinit var defaultMetrics: DefaultNetworkMetrics
     @Spy
     private var context = TestableContext(realContext)
 
@@ -149,7 +143,6 @@
     @Before
     fun setUp() {
         MockitoAnnotations.initMocks(this)
-        doReturn(defaultMetrics).`when`(metricsLogger).defaultNetworkMetrics()
         doNothing().`when`(context).sendStickyBroadcastAsUser(any(), any(), any())
 
         networkStackClient = TestNetworkStackClient(realContext)
@@ -173,7 +166,6 @@
     private fun makeDependencies(): ConnectivityService.Dependencies {
         val deps = spy(ConnectivityService.Dependencies())
         doReturn(networkStackClient).`when`(deps).networkStack
-        doReturn(metricsLogger).`when`(deps).metricsLogger
         doReturn(mock(ProxyTracker::class.java)).`when`(deps).makeProxyTracker(any(), any())
         doReturn(mock(MockableSystemProperties::class.java)).`when`(deps).systemProperties
         doReturn(TestNetIdManager()).`when`(deps).makeNetIdManager()
diff --git a/tests/net/integration/util/com/android/server/NetworkAgentWrapper.java b/tests/net/integration/util/com/android/server/NetworkAgentWrapper.java
index 3d4dc4d..dc9e587 100644
--- a/tests/net/integration/util/com/android/server/NetworkAgentWrapper.java
+++ b/tests/net/integration/util/com/android/server/NetworkAgentWrapper.java
@@ -31,6 +31,7 @@
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.fail;
 
+import android.annotation.NonNull;
 import android.content.Context;
 import android.net.ConnectivityManager;
 import android.net.LinkProperties;
@@ -40,6 +41,7 @@
 import android.net.NetworkCapabilities;
 import android.net.NetworkProvider;
 import android.net.NetworkSpecifier;
+import android.net.QosFilter;
 import android.net.SocketKeepalive;
 import android.net.UidRange;
 import android.os.ConditionVariable;
@@ -47,10 +49,12 @@
 import android.os.Message;
 import android.util.Log;
 
+import com.android.net.module.util.ArrayTrackRecord;
 import com.android.server.connectivity.ConnectivityConstants;
 import com.android.testutils.HandlerUtils;
 import com.android.testutils.TestableNetworkCallback;
 
+import java.util.Objects;
 import java.util.Set;
 import java.util.concurrent.atomic.AtomicBoolean;
 
@@ -71,6 +75,8 @@
     // start/stop. Useful when simulate KeepaliveTracker is waiting for response from modem.
     private long mKeepaliveResponseDelay = 0L;
     private Integer mExpectedKeepaliveSlot = null;
+    private final ArrayTrackRecord<CallbackType>.ReadHead mCallbackHistory =
+            new ArrayTrackRecord<CallbackType>().newReadHead();
 
     public NetworkAgentWrapper(int transport, LinkProperties linkProperties,
             NetworkCapabilities ncTemplate, Context context) throws Exception {
@@ -157,6 +163,20 @@
         }
 
         @Override
+        public void onQosCallbackRegistered(final int qosCallbackId,
+                final @NonNull QosFilter filter) {
+            Log.i(mWrapper.mLogTag, "onQosCallbackRegistered");
+            mWrapper.mCallbackHistory.add(
+                    new CallbackType.OnQosCallbackRegister(qosCallbackId, filter));
+        }
+
+        @Override
+        public void onQosCallbackUnregistered(final int qosCallbackId) {
+            Log.i(mWrapper.mLogTag, "onQosCallbackUnregistered");
+            mWrapper.mCallbackHistory.add(new CallbackType.OnQosCallbackUnregister(qosCallbackId));
+        }
+
+        @Override
         protected void preventAutomaticReconnect() {
             mWrapper.mPreventReconnectReceived.open();
         }
@@ -279,7 +299,60 @@
         return mNetworkCapabilities;
     }
 
+    public @NonNull ArrayTrackRecord<CallbackType>.ReadHead getCallbackHistory() {
+        return mCallbackHistory;
+    }
+
     public void waitForIdle(long timeoutMs) {
         HandlerUtils.waitForIdle(mHandlerThread, timeoutMs);
     }
+
+    abstract static class CallbackType {
+        final int mQosCallbackId;
+
+        protected CallbackType(final int qosCallbackId) {
+            mQosCallbackId = qosCallbackId;
+        }
+
+        static class OnQosCallbackRegister extends CallbackType {
+            final QosFilter mFilter;
+            OnQosCallbackRegister(final int qosCallbackId, final QosFilter filter) {
+                super(qosCallbackId);
+                mFilter = filter;
+            }
+
+            @Override
+            public boolean equals(final Object o) {
+                if (this == o) return true;
+                if (o == null || getClass() != o.getClass()) return false;
+                final OnQosCallbackRegister that = (OnQosCallbackRegister) o;
+                return mQosCallbackId == that.mQosCallbackId
+                        && Objects.equals(mFilter, that.mFilter);
+            }
+
+            @Override
+            public int hashCode() {
+                return Objects.hash(mQosCallbackId, mFilter);
+            }
+        }
+
+        static class OnQosCallbackUnregister extends CallbackType {
+            OnQosCallbackUnregister(final int qosCallbackId) {
+                super(qosCallbackId);
+            }
+
+            @Override
+            public boolean equals(final Object o) {
+                if (this == o) return true;
+                if (o == null || getClass() != o.getClass()) return false;
+                final OnQosCallbackUnregister that = (OnQosCallbackUnregister) o;
+                return mQosCallbackId == that.mQosCallbackId;
+            }
+
+            @Override
+            public int hashCode() {
+                return Objects.hash(mQosCallbackId);
+            }
+        }
+    }
 }
diff --git a/tests/net/java/com/android/server/ConnectivityServiceTest.java b/tests/net/java/com/android/server/ConnectivityServiceTest.java
index 4a282e8..f893e9e 100644
--- a/tests/net/java/com/android/server/ConnectivityServiceTest.java
+++ b/tests/net/java/com/android/server/ConnectivityServiceTest.java
@@ -21,6 +21,7 @@
 import static android.app.PendingIntent.FLAG_IMMUTABLE;
 import static android.content.Intent.ACTION_USER_ADDED;
 import static android.content.Intent.ACTION_USER_REMOVED;
+import static android.content.Intent.ACTION_USER_UNLOCKED;
 import static android.content.pm.PackageInfo.REQUESTED_PERMISSION_GRANTED;
 import static android.content.pm.PackageManager.GET_PERMISSIONS;
 import static android.content.pm.PackageManager.MATCH_ANY_USER;
@@ -166,6 +167,7 @@
 import android.net.INetworkMonitorCallbacks;
 import android.net.INetworkPolicyListener;
 import android.net.INetworkStatsService;
+import android.net.IQosCallback;
 import android.net.InetAddresses;
 import android.net.InterfaceConfigurationParcel;
 import android.net.IpPrefix;
@@ -189,6 +191,9 @@
 import android.net.NetworkState;
 import android.net.NetworkTestResultParcelable;
 import android.net.ProxyInfo;
+import android.net.QosCallbackException;
+import android.net.QosFilter;
+import android.net.QosSession;
 import android.net.ResolverParamsParcel;
 import android.net.RouteInfo;
 import android.net.RouteInfoParcel;
@@ -217,17 +222,21 @@
 import android.os.Parcelable;
 import android.os.Process;
 import android.os.RemoteException;
+import android.os.ServiceSpecificException;
 import android.os.SystemClock;
 import android.os.UserHandle;
 import android.os.UserManager;
 import android.provider.Settings;
+import android.security.Credentials;
 import android.security.KeyStore;
 import android.system.Os;
 import android.telephony.TelephonyManager;
+import android.telephony.data.EpsBearerQosSessionAttributes;
 import android.test.mock.MockContentResolver;
 import android.text.TextUtils;
 import android.util.ArraySet;
 import android.util.Log;
+import android.util.Pair;
 import android.util.SparseArray;
 
 import androidx.test.InstrumentationRegistry;
@@ -237,19 +246,19 @@
 import com.android.internal.app.IBatteryStats;
 import com.android.internal.net.VpnConfig;
 import com.android.internal.net.VpnInfo;
+import com.android.internal.net.VpnProfile;
 import com.android.internal.util.ArrayUtils;
 import com.android.internal.util.WakeupMessage;
 import com.android.internal.util.test.BroadcastInterceptingContext;
 import com.android.internal.util.test.FakeSettingsProvider;
 import com.android.server.ConnectivityService.ConnectivityDiagnosticsCallbackInfo;
 import com.android.server.connectivity.ConnectivityConstants;
-import com.android.server.connectivity.DefaultNetworkMetrics;
-import com.android.server.connectivity.IpConnectivityMetrics;
 import com.android.server.connectivity.MockableSystemProperties;
 import com.android.server.connectivity.Nat464Xlat;
 import com.android.server.connectivity.NetworkAgentInfo;
 import com.android.server.connectivity.NetworkNotificationManager.NotificationType;
 import com.android.server.connectivity.ProxyTracker;
+import com.android.server.connectivity.QosCallbackTracker;
 import com.android.server.connectivity.Vpn;
 import com.android.server.net.NetworkPinner;
 import com.android.server.net.NetworkPolicyManagerInternal;
@@ -281,6 +290,7 @@
 import java.net.InetAddress;
 import java.net.InetSocketAddress;
 import java.net.Socket;
+import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
@@ -366,9 +376,9 @@
     private WrappedMultinetworkPolicyTracker mPolicyTracker;
     private HandlerThread mAlarmManagerThread;
     private TestNetIdManager mNetIdManager;
+    private QosCallbackMockHelper mQosCallbackMockHelper;
+    private QosCallbackTracker mQosCallbackTracker;
 
-    @Mock IpConnectivityMetrics.Logger mMetricsService;
-    @Mock DefaultNetworkMetrics mDefaultNetworkMetrics;
     @Mock DeviceIdleInternal mDeviceIdleInternal;
     @Mock INetworkManagementService mNetworkManagementService;
     @Mock INetworkStatsService mStatsService;
@@ -388,6 +398,7 @@
     @Mock MockableSystemProperties mSystemProperties;
     @Mock EthernetManager mEthernetManager;
     @Mock NetworkPolicyManager mNetworkPolicyManager;
+    @Mock KeyStore mKeyStore;
 
     private ArgumentCaptor<ResolverParamsParcel> mResolverParamsParcelCaptor =
             ArgumentCaptor.forClass(ResolverParamsParcel.class);
@@ -1066,6 +1077,15 @@
         private int mVpnType = VpnManager.TYPE_VPN_SERVICE;
         private VpnInfo mVpnInfo;
 
+        // These ConditionVariables allow tests to wait for LegacyVpnRunner to be stopped/started.
+        // TODO: this scheme is ad-hoc and error-prone because it does not fail if, for example, the
+        // test expects two starts in a row, or even if the production code calls start twice in a
+        // row. find a better solution. Simply putting a method to create a LegacyVpnRunner into
+        // Vpn.Dependencies doesn't work because LegacyVpnRunner is not a static class and has
+        // extensive access into the internals of Vpn.
+        private ConditionVariable mStartLegacyVpnCv = new ConditionVariable();
+        private ConditionVariable mStopVpnRunnerCv = new ConditionVariable();
+
         public MockVpn(int userId) {
             super(startHandlerThreadAndReturnLooper(), mServiceContext,
                     new Dependencies() {
@@ -1079,7 +1099,7 @@
                             return mDeviceIdleInternal;
                         }
                     },
-                    mNetworkManagementService, mMockNetd, userId, mock(KeyStore.class));
+                    mNetworkManagementService, mMockNetd, userId, mKeyStore);
         }
 
         public void setUids(Set<UidRange> uids) {
@@ -1191,10 +1211,44 @@
             }
             mAgentRegistered = false;
             setUids(null);
+            // Remove NET_CAPABILITY_INTERNET or MockNetworkAgent will refuse to connect later on.
+            mNetworkCapabilities.removeCapability(NET_CAPABILITY_INTERNET);
             mInterface = null;
         }
 
         @Override
+        public void startLegacyVpnRunner() {
+            mStartLegacyVpnCv.open();
+        }
+
+        public void expectStartLegacyVpnRunner() {
+            assertTrue("startLegacyVpnRunner not called after " + TIMEOUT_MS + " ms",
+                    mStartLegacyVpnCv.block(TIMEOUT_MS));
+
+            // startLegacyVpn calls stopVpnRunnerPrivileged, which will open mStopVpnRunnerCv, just
+            // before calling startLegacyVpnRunner. Restore mStopVpnRunnerCv, so the test can expect
+            // that the VpnRunner is stopped and immediately restarted by calling
+            // expectStartLegacyVpnRunner() and expectStopVpnRunnerPrivileged() back-to-back.
+            mStopVpnRunnerCv = new ConditionVariable();
+        }
+
+        @Override
+        public void stopVpnRunnerPrivileged() {
+            if (mVpnRunner != null) {
+                super.stopVpnRunnerPrivileged();
+                disconnect();
+                mStartLegacyVpnCv = new ConditionVariable();
+            }
+            mVpnRunner = null;
+            mStopVpnRunnerCv.open();
+        }
+
+        public void expectStopVpnRunnerPrivileged() {
+            assertTrue("stopVpnRunnerPrivileged not called after " + TIMEOUT_MS + " ms",
+                    mStopVpnRunnerCv.block(TIMEOUT_MS));
+        }
+
+        @Override
         public synchronized VpnInfo getVpnInfo() {
             if (mVpnInfo != null) return mVpnInfo;
 
@@ -1275,10 +1329,19 @@
         }
     }
 
-    private static final int VPN_USER = 0;
-    private static final int APP1_UID = UserHandle.getUid(VPN_USER, 10100);
-    private static final int APP2_UID = UserHandle.getUid(VPN_USER, 10101);
-    private static final int VPN_UID = UserHandle.getUid(VPN_USER, 10043);
+    private static final int PRIMARY_USER = 0;
+    private static final int APP1_UID = UserHandle.getUid(PRIMARY_USER, 10100);
+    private static final int APP2_UID = UserHandle.getUid(PRIMARY_USER, 10101);
+    private static final int VPN_UID = UserHandle.getUid(PRIMARY_USER, 10043);
+    private static final UserInfo PRIMARY_USER_INFO = new UserInfo(PRIMARY_USER, "",
+            UserInfo.FLAG_PRIMARY);
+
+    private static final int RESTRICTED_USER = 1;
+    private static final UserInfo RESTRICTED_USER_INFO = new UserInfo(RESTRICTED_USER, "",
+            UserInfo.FLAG_RESTRICTED);
+    static {
+        RESTRICTED_USER_INFO.restrictedProfileParentId = PRIMARY_USER;
+    }
 
     @Before
     public void setUp() throws Exception {
@@ -1287,12 +1350,14 @@
         mContext = InstrumentationRegistry.getContext();
 
         MockitoAnnotations.initMocks(this);
-        when(mMetricsService.defaultNetworkMetrics()).thenReturn(mDefaultNetworkMetrics);
 
-        when(mUserManager.getAliveUsers()).thenReturn(
-                Arrays.asList(new UserInfo[] {
-                        new UserInfo(VPN_USER, "", 0),
-                }));
+        when(mUserManager.getAliveUsers()).thenReturn(Arrays.asList(PRIMARY_USER_INFO));
+        when(mUserManager.getUserInfo(PRIMARY_USER)).thenReturn(PRIMARY_USER_INFO);
+        // canHaveRestrictedProfile does not take a userId. It applies to the userId of the context
+        // it was started from, i.e., PRIMARY_USER.
+        when(mUserManager.canHaveRestrictedProfile()).thenReturn(true);
+        when(mUserManager.getUserInfo(RESTRICTED_USER)).thenReturn(RESTRICTED_USER_INFO);
+
         final ApplicationInfo applicationInfo = new ApplicationInfo();
         applicationInfo.targetSdkVersion = Build.VERSION_CODES.Q;
         when(mPackageManager.getApplicationInfoAsUser(anyString(), anyInt(), any()))
@@ -1340,6 +1405,7 @@
         mService.systemReadyInternal();
         mockVpn(Process.myUid());
         mCm.bindProcessToNetwork(null);
+        mQosCallbackTracker = mock(QosCallbackTracker.class);
 
         // Ensure that the default setting for Captive Portals is used for most tests
         setCaptivePortalMode(Settings.Global.CAPTIVE_PORTAL_MODE_PROMPT);
@@ -1362,9 +1428,9 @@
         doReturn(mNetworkStack).when(deps).getNetworkStack();
         doReturn(mSystemProperties).when(deps).getSystemProperties();
         doReturn(mock(ProxyTracker.class)).when(deps).makeProxyTracker(any(), any());
-        doReturn(mMetricsService).when(deps).getMetricsLogger();
         doReturn(true).when(deps).queryUserAccess(anyInt(), anyInt());
         doReturn(mBatteryStatsService).when(deps).getBatteryStatsService();
+        doReturn(mKeyStore).when(deps).getKeyStore();
         doAnswer(inv -> {
             mPolicyTracker = new WrappedMultinetworkPolicyTracker(
                     inv.getArgument(0), inv.getArgument(1), inv.getArgument(2));
@@ -1415,6 +1481,11 @@
             mEthernetNetworkAgent.disconnect();
             mEthernetNetworkAgent = null;
         }
+
+        if (mQosCallbackMockHelper != null) {
+            mQosCallbackMockHelper.tearDown();
+            mQosCallbackMockHelper = null;
+        }
         mMockVpn.disconnect();
         waitForIdle();
 
@@ -1533,7 +1604,7 @@
             waitForIdle();
             try {
                 final Intent intent = get(timeoutMs, TimeUnit.MILLISECONDS);
-                fail("Unexpected broadcast: " + intent.getAction());
+                fail("Unexpected broadcast: " + intent.getAction() + " " + intent.getExtras());
             } catch (TimeoutException expected) {
             } finally {
                 mServiceContext.unregisterReceiver(mReceiver);
@@ -2074,10 +2145,6 @@
 
     @Test
     public void testOwnerUidCannotChange() throws Exception {
-        // Owner UIDs are not visible without location permission.
-        setupLocationPermissions(Build.VERSION_CODES.Q, true, AppOpsManager.OPSTR_FINE_LOCATION,
-                Manifest.permission.ACCESS_FINE_LOCATION);
-
         final NetworkCapabilities ncTemplate = new NetworkCapabilities();
         final int originalOwnerUid = Process.myUid();
         ncTemplate.setOwnerUid(originalOwnerUid);
@@ -2097,6 +2164,10 @@
         mWiFiNetworkAgent.setNetworkCapabilities(agentCapabilities, true);
         waitForIdle();
 
+        // Owner UIDs are not visible without location permission.
+        setupLocationPermissions(Build.VERSION_CODES.Q, true, AppOpsManager.OPSTR_FINE_LOCATION,
+                Manifest.permission.ACCESS_FINE_LOCATION);
+
         // Check that the capability change has been applied but the owner UID is not modified.
         NetworkCapabilities nc = mCm.getNetworkCapabilities(mWiFiNetworkAgent.getNetwork());
         assertEquals(originalOwnerUid, nc.getOwnerUid());
@@ -4324,7 +4395,7 @@
     }
 
     private Network connectKeepaliveNetwork(LinkProperties lp) throws Exception {
-        // Ensure the network is disconnected before we do anything.
+        // Ensure the network is disconnected before anything else occurs
         if (mWiFiNetworkAgent != null) {
             assertNull(mCm.getNetworkCapabilities(mWiFiNetworkAgent.getNetwork()));
         }
@@ -5837,6 +5908,131 @@
         mCm.unregisterNetworkCallback(callback);
     }
 
+    private void assertGetNetworkInfoOfGetActiveNetworkIsConnected(boolean expectedConnectivity) {
+        // What Chromium used to do before https://chromium-review.googlesource.com/2605304
+        assertEquals("Unexpected result for getActiveNetworkInfo(getActiveNetwork())",
+                expectedConnectivity, mCm.getNetworkInfo(mCm.getActiveNetwork()).isConnected());
+    }
+
+    @Test
+    public void testVpnUnderlyingNetworkSuspended() throws Exception {
+        final TestNetworkCallback callback = new TestNetworkCallback();
+        mCm.registerDefaultNetworkCallback(callback);
+
+        // Connect a VPN.
+        mMockVpn.establishForMyUid(false /* validated */, true /* hasInternet */,
+                false /* isStrictMode */);
+        callback.expectAvailableCallbacksUnvalidated(mMockVpn);
+
+        // Connect cellular data.
+        mCellNetworkAgent = new TestNetworkAgentWrapper(TRANSPORT_CELLULAR);
+        mCellNetworkAgent.connect(false /* validated */);
+        callback.expectCapabilitiesThat(mMockVpn,
+                nc -> nc.hasCapability(NET_CAPABILITY_NOT_SUSPENDED)
+                        && nc.hasTransport(TRANSPORT_CELLULAR));
+        callback.assertNoCallback();
+
+        assertTrue(mCm.getNetworkCapabilities(mMockVpn.getNetwork())
+                .hasCapability(NET_CAPABILITY_NOT_SUSPENDED));
+        assertNetworkInfo(TYPE_MOBILE, DetailedState.CONNECTED);
+        assertNetworkInfo(TYPE_WIFI, DetailedState.DISCONNECTED);
+        assertNetworkInfo(TYPE_VPN, DetailedState.CONNECTED);
+        assertActiveNetworkInfo(TYPE_MOBILE, DetailedState.CONNECTED);
+        assertGetNetworkInfoOfGetActiveNetworkIsConnected(true);
+
+        // Suspend the cellular network and expect the VPN to be suspended.
+        mCellNetworkAgent.suspend();
+        callback.expectCapabilitiesThat(mMockVpn,
+                nc -> !nc.hasCapability(NET_CAPABILITY_NOT_SUSPENDED)
+                        && nc.hasTransport(TRANSPORT_CELLULAR));
+        callback.expectCallback(CallbackEntry.SUSPENDED, mMockVpn);
+        callback.assertNoCallback();
+
+        assertFalse(mCm.getNetworkCapabilities(mMockVpn.getNetwork())
+                .hasCapability(NET_CAPABILITY_NOT_SUSPENDED));
+        assertNetworkInfo(TYPE_MOBILE, DetailedState.SUSPENDED);
+        assertNetworkInfo(TYPE_WIFI, DetailedState.DISCONNECTED);
+        assertNetworkInfo(TYPE_VPN, DetailedState.SUSPENDED);
+        assertActiveNetworkInfo(TYPE_MOBILE, DetailedState.SUSPENDED);
+        // VPN's main underlying network is suspended, so no connectivity.
+        assertGetNetworkInfoOfGetActiveNetworkIsConnected(false);
+
+        // Switch to another network. The VPN should no longer be suspended.
+        mWiFiNetworkAgent = new TestNetworkAgentWrapper(TRANSPORT_WIFI);
+        mWiFiNetworkAgent.connect(false /* validated */);
+        callback.expectCapabilitiesThat(mMockVpn,
+                nc -> nc.hasCapability(NET_CAPABILITY_NOT_SUSPENDED)
+                        && nc.hasTransport(TRANSPORT_WIFI));
+
+        // BUG: the VPN is no longer suspended, so a RESUMED callback should have been sent.
+        // callback.expectCallback(CallbackEntry.RESUMED, mMockVpn);
+        callback.assertNoCallback();
+
+        assertTrue(mCm.getNetworkCapabilities(mMockVpn.getNetwork())
+                .hasCapability(NET_CAPABILITY_NOT_SUSPENDED));
+        assertNetworkInfo(TYPE_MOBILE, DetailedState.DISCONNECTED);
+        assertNetworkInfo(TYPE_WIFI, DetailedState.CONNECTED);
+        assertNetworkInfo(TYPE_VPN, DetailedState.SUSPENDED);  // BUG: VPN caps have NOT_SUSPENDED.
+        assertActiveNetworkInfo(TYPE_WIFI, DetailedState.CONNECTED);
+        // BUG: the device has connectivity, so this should return true.
+        assertGetNetworkInfoOfGetActiveNetworkIsConnected(false);
+
+        // Unsuspend cellular and then switch back to it.
+        // The same bug happens in the opposite direction: the VPN's capabilities correctly have
+        // NOT_SUSPENDED, but the VPN's NetworkInfo is in state SUSPENDED.
+        mCellNetworkAgent.resume();
+        callback.assertNoCallback();
+        mWiFiNetworkAgent.disconnect();
+        callback.expectCapabilitiesThat(mMockVpn,
+                nc -> nc.hasCapability(NET_CAPABILITY_NOT_SUSPENDED)
+                        && nc.hasTransport(TRANSPORT_CELLULAR));
+        // Spurious double callback?
+        callback.expectCapabilitiesThat(mMockVpn,
+                nc -> nc.hasCapability(NET_CAPABILITY_NOT_SUSPENDED)
+                        && nc.hasTransport(TRANSPORT_CELLULAR));
+        callback.assertNoCallback();
+
+        assertTrue(mCm.getNetworkCapabilities(mMockVpn.getNetwork())
+                .hasCapability(NET_CAPABILITY_NOT_SUSPENDED));
+        assertNetworkInfo(TYPE_MOBILE, DetailedState.CONNECTED);
+        assertNetworkInfo(TYPE_WIFI, DetailedState.DISCONNECTED);
+        assertNetworkInfo(TYPE_VPN, DetailedState.SUSPENDED);  // BUG: VPN caps have NOT_SUSPENDED.
+        assertActiveNetworkInfo(TYPE_MOBILE, DetailedState.CONNECTED);
+        // BUG: the device has connectivity, so this should return true.
+        assertGetNetworkInfoOfGetActiveNetworkIsConnected(false);
+
+        // Re-suspending the current network fixes the problem.
+        mCellNetworkAgent.suspend();
+        callback.expectCapabilitiesThat(mMockVpn,
+                nc -> !nc.hasCapability(NET_CAPABILITY_NOT_SUSPENDED)
+                        && nc.hasTransport(TRANSPORT_CELLULAR));
+        callback.expectCallback(CallbackEntry.SUSPENDED, mMockVpn);
+        callback.assertNoCallback();
+
+        assertFalse(mCm.getNetworkCapabilities(mMockVpn.getNetwork())
+                .hasCapability(NET_CAPABILITY_NOT_SUSPENDED));
+        assertNetworkInfo(TYPE_MOBILE, DetailedState.SUSPENDED);
+        assertNetworkInfo(TYPE_WIFI, DetailedState.DISCONNECTED);
+        assertNetworkInfo(TYPE_VPN, DetailedState.SUSPENDED);
+        assertActiveNetworkInfo(TYPE_MOBILE, DetailedState.SUSPENDED);
+        assertGetNetworkInfoOfGetActiveNetworkIsConnected(false);
+
+        mCellNetworkAgent.resume();
+        callback.expectCapabilitiesThat(mMockVpn,
+                nc -> nc.hasCapability(NET_CAPABILITY_NOT_SUSPENDED)
+                        && nc.hasTransport(TRANSPORT_CELLULAR));
+        callback.expectCallback(CallbackEntry.RESUMED, mMockVpn);
+        callback.assertNoCallback();
+
+        assertTrue(mCm.getNetworkCapabilities(mMockVpn.getNetwork())
+                .hasCapability(NET_CAPABILITY_NOT_SUSPENDED));
+        assertNetworkInfo(TYPE_MOBILE, DetailedState.CONNECTED);
+        assertNetworkInfo(TYPE_WIFI, DetailedState.DISCONNECTED);
+        assertNetworkInfo(TYPE_VPN, DetailedState.CONNECTED);
+        assertActiveNetworkInfo(TYPE_MOBILE, DetailedState.CONNECTED);
+        assertGetNetworkInfoOfGetActiveNetworkIsConnected(true);
+    }
+
     @Test
     public void testVpnNetworkActive() throws Exception {
         final int uid = Process.myUid();
@@ -6315,7 +6511,7 @@
     }
 
     @Test
-    public void testVpnRestrictedUsers() throws Exception {
+    public void testRestrictedProfileAffectsVpnUidRanges() throws Exception {
         // NETWORK_SETTINGS is necessary to see the UID ranges in NetworkCapabilities.
         mServiceContext.setPermission(Manifest.permission.NETWORK_SETTINGS,
                 PERMISSION_GRANTED);
@@ -6347,19 +6543,11 @@
         callback.expectCapabilitiesThat(mWiFiNetworkAgent, (caps)
                 -> caps.hasCapability(NET_CAPABILITY_VALIDATED));
 
-        // Create a fake restricted profile whose parent is our user ID.
-        final int userId = UserHandle.getUserId(uid);
-        when(mUserManager.canHaveRestrictedProfile()).thenReturn(true);
-        final int restrictedUserId = userId + 1;
-        final UserInfo info = new UserInfo(restrictedUserId, "user", UserInfo.FLAG_RESTRICTED);
-        info.restrictedProfileParentId = userId;
-        assertTrue(info.isRestricted());
-        when(mUserManager.getUserInfo(restrictedUserId)).thenReturn(info);
-        when(mPackageManager.getPackageUidAsUser(ALWAYS_ON_PACKAGE, restrictedUserId))
-                .thenReturn(UserHandle.getUid(restrictedUserId, VPN_UID));
+        when(mPackageManager.getPackageUidAsUser(ALWAYS_ON_PACKAGE, RESTRICTED_USER))
+                .thenReturn(UserHandle.getUid(RESTRICTED_USER, VPN_UID));
 
         final Intent addedIntent = new Intent(ACTION_USER_ADDED);
-        addedIntent.putExtra(Intent.EXTRA_USER_HANDLE, restrictedUserId);
+        addedIntent.putExtra(Intent.EXTRA_USER_HANDLE, RESTRICTED_USER);
 
         // Send a USER_ADDED broadcast for it.
         // The BroadcastReceiver for this broadcast checks that is being run on the handler thread.
@@ -6371,7 +6559,7 @@
         callback.expectCapabilitiesThat(mMockVpn, (caps)
                 -> caps.getUids().size() == 2
                 && caps.getUids().contains(new UidRange(uid, uid))
-                && caps.getUids().contains(UidRange.createForUser(restrictedUserId))
+                && caps.getUids().contains(UidRange.createForUser(RESTRICTED_USER))
                 && caps.hasTransport(TRANSPORT_VPN)
                 && caps.hasTransport(TRANSPORT_WIFI));
 
@@ -6381,13 +6569,13 @@
         callback.expectCapabilitiesThat(mMockVpn, (caps)
                 -> caps.getUids().size() == 2
                 && caps.getUids().contains(new UidRange(uid, uid))
-                && caps.getUids().contains(UidRange.createForUser(restrictedUserId))
+                && caps.getUids().contains(UidRange.createForUser(RESTRICTED_USER))
                 && caps.hasTransport(TRANSPORT_VPN)
                 && !caps.hasTransport(TRANSPORT_WIFI));
 
         // Send a USER_REMOVED broadcast and expect to lose the UID range for the restricted user.
         final Intent removedIntent = new Intent(ACTION_USER_REMOVED);
-        removedIntent.putExtra(Intent.EXTRA_USER_HANDLE, restrictedUserId);
+        removedIntent.putExtra(Intent.EXTRA_USER_HANDLE, RESTRICTED_USER);
         handler.post(() -> mServiceContext.sendBroadcast(removedIntent));
 
         // Expect that the VPN gains the UID range for the restricted user, and that the capability
@@ -6397,53 +6585,72 @@
                 && caps.getUids().contains(new UidRange(uid, uid))
                 && caps.hasTransport(TRANSPORT_VPN)
                 && !caps.hasTransport(TRANSPORT_WIFI));
+    }
 
-        // Test lockdown with restricted profiles.
+    @Test
+    public void testLockdownVpnWithRestrictedProfiles() throws Exception {
+        // For ConnectivityService#setAlwaysOnVpnPackage.
         mServiceContext.setPermission(
                 Manifest.permission.CONTROL_ALWAYS_ON_VPN, PERMISSION_GRANTED);
+        // For call Vpn#setAlwaysOnPackage.
         mServiceContext.setPermission(
                 Manifest.permission.CONTROL_VPN, PERMISSION_GRANTED);
+        // Necessary to see the UID ranges in NetworkCapabilities.
         mServiceContext.setPermission(
                 Manifest.permission.NETWORK_SETTINGS, PERMISSION_GRANTED);
 
+        final NetworkRequest request = new NetworkRequest.Builder()
+                .removeCapability(NET_CAPABILITY_NOT_VPN)
+                .build();
+        final TestNetworkCallback callback = new TestNetworkCallback();
+        mCm.registerNetworkCallback(request, callback);
+
+        final int uid = Process.myUid();
+
         // Connect wifi and check that UIDs in the main and restricted profiles have network access.
-        mMockVpn.disconnect();
         mWiFiNetworkAgent = new TestNetworkAgentWrapper(TRANSPORT_WIFI);
         mWiFiNetworkAgent.connect(true /* validated */);
-        final int restrictedUid = UserHandle.getUid(restrictedUserId, 42 /* appId */);
+        final int restrictedUid = UserHandle.getUid(RESTRICTED_USER, 42 /* appId */);
         assertNotNull(mCm.getActiveNetworkForUid(uid));
         assertNotNull(mCm.getActiveNetworkForUid(restrictedUid));
 
         // Enable always-on VPN lockdown. The main user loses network access because no VPN is up.
         final ArrayList<String> allowList = new ArrayList<>();
-        mService.setAlwaysOnVpnPackage(userId, ALWAYS_ON_PACKAGE, true /* lockdown */, allowList);
+        mService.setAlwaysOnVpnPackage(PRIMARY_USER, ALWAYS_ON_PACKAGE, true /* lockdown */,
+                allowList);
         waitForIdle();
         assertNull(mCm.getActiveNetworkForUid(uid));
+        // This is arguably overspecified: a UID that is not running doesn't have an active network.
+        // But it's useful to check that non-default users do not lose network access, and to prove
+        // that the loss of connectivity below is indeed due to the restricted profile coming up.
         assertNotNull(mCm.getActiveNetworkForUid(restrictedUid));
 
         // Start the restricted profile, and check that the UID within it loses network access.
-        when(mUserManager.getAliveUsers()).thenReturn(
-                Arrays.asList(new UserInfo[] {
-                        new UserInfo(userId, "", 0),
-                        info
-                }));
+        when(mPackageManager.getPackageUidAsUser(ALWAYS_ON_PACKAGE, RESTRICTED_USER))
+                .thenReturn(UserHandle.getUid(RESTRICTED_USER, VPN_UID));
+        when(mUserManager.getAliveUsers()).thenReturn(Arrays.asList(PRIMARY_USER_INFO,
+                RESTRICTED_USER_INFO));
         // TODO: check that VPN app within restricted profile still has access, etc.
+        final Intent addedIntent = new Intent(ACTION_USER_ADDED);
+        addedIntent.putExtra(Intent.EXTRA_USER_HANDLE, RESTRICTED_USER);
+        final Handler handler = new Handler(mCsHandlerThread.getLooper());
         handler.post(() -> mServiceContext.sendBroadcast(addedIntent));
         waitForIdle();
         assertNull(mCm.getActiveNetworkForUid(uid));
         assertNull(mCm.getActiveNetworkForUid(restrictedUid));
 
         // Stop the restricted profile, and check that the UID within it has network access again.
-        when(mUserManager.getAliveUsers()).thenReturn(
-                Arrays.asList(new UserInfo[] {
-                        new UserInfo(userId, "", 0),
-                }));
+        when(mUserManager.getAliveUsers()).thenReturn(Arrays.asList(PRIMARY_USER_INFO));
+
+        // Send a USER_REMOVED broadcast and expect to lose the UID range for the restricted user.
+        final Intent removedIntent = new Intent(ACTION_USER_REMOVED);
+        removedIntent.putExtra(Intent.EXTRA_USER_HANDLE, RESTRICTED_USER);
         handler.post(() -> mServiceContext.sendBroadcast(removedIntent));
         waitForIdle();
         assertNull(mCm.getActiveNetworkForUid(uid));
         assertNotNull(mCm.getActiveNetworkForUid(restrictedUid));
 
-        mService.setAlwaysOnVpnPackage(userId, null, false /* lockdown */, allowList);
+        mService.setAlwaysOnVpnPackage(PRIMARY_USER, null, false /* lockdown */, allowList);
         waitForIdle();
     }
 
@@ -6784,6 +6991,7 @@
         final int userId = UserHandle.getUserId(uid);
         final ArrayList<String> allowList = new ArrayList<>();
         mService.setAlwaysOnVpnPackage(userId, ALWAYS_ON_PACKAGE, true /* lockdown */, allowList);
+        waitForIdle();
 
         UidRangeParcel firstHalf = new UidRangeParcel(1, VPN_UID - 1);
         UidRangeParcel secondHalf = new UidRangeParcel(VPN_UID + 1, 99999);
@@ -6805,10 +7013,10 @@
 
         // Disable lockdown, expect to see the network unblocked.
         mService.setAlwaysOnVpnPackage(userId, null, false /* lockdown */, allowList);
-        expectNetworkRejectNonSecureVpn(inOrder, false, firstHalf, secondHalf);
         callback.expectBlockedStatusCallback(false, mWiFiNetworkAgent);
         defaultCallback.expectBlockedStatusCallback(false, mWiFiNetworkAgent);
         vpnUidCallback.assertNoCallback();
+        expectNetworkRejectNonSecureVpn(inOrder, false, firstHalf, secondHalf);
         assertEquals(mWiFiNetworkAgent.getNetwork(), mCm.getActiveNetworkForUid(VPN_UID));
         assertEquals(mWiFiNetworkAgent.getNetwork(), mCm.getActiveNetwork());
         assertActiveNetworkInfo(TYPE_WIFI, DetailedState.CONNECTED);
@@ -6851,9 +7059,11 @@
         // Disable lockdown, remove our UID from the allowlist, and re-enable lockdown.
         // Everything should now be blocked.
         mService.setAlwaysOnVpnPackage(userId, null, false /* lockdown */, allowList);
+        waitForIdle();
         expectNetworkRejectNonSecureVpn(inOrder, false, piece1, piece2, piece3);
         allowList.clear();
         mService.setAlwaysOnVpnPackage(userId, ALWAYS_ON_PACKAGE, true /* lockdown */, allowList);
+        waitForIdle();
         expectNetworkRejectNonSecureVpn(inOrder, true, firstHalf, secondHalf);
         defaultCallback.expectBlockedStatusCallback(true, mWiFiNetworkAgent);
         assertBlockedCallbackInAnyOrder(callback, true, mWiFiNetworkAgent, mCellNetworkAgent);
@@ -6931,6 +7141,200 @@
         mCm.unregisterNetworkCallback(vpnUidCallback);
     }
 
+    private void setupLegacyLockdownVpn() {
+        final String profileName = "testVpnProfile";
+        final byte[] profileTag = profileName.getBytes(StandardCharsets.UTF_8);
+        when(mKeyStore.contains(Credentials.LOCKDOWN_VPN)).thenReturn(true);
+        when(mKeyStore.get(Credentials.LOCKDOWN_VPN)).thenReturn(profileTag);
+
+        final VpnProfile profile = new VpnProfile(profileName);
+        profile.name = "My VPN";
+        profile.server = "192.0.2.1";
+        profile.dnsServers = "8.8.8.8";
+        profile.type = VpnProfile.TYPE_IPSEC_XAUTH_PSK;
+        final byte[] encodedProfile = profile.encode();
+        when(mKeyStore.get(Credentials.VPN + profileName)).thenReturn(encodedProfile);
+    }
+
+    @Test
+    public void testLegacyLockdownVpn() throws Exception {
+        mServiceContext.setPermission(
+                Manifest.permission.CONTROL_VPN, PERMISSION_GRANTED);
+
+        final NetworkRequest request = new NetworkRequest.Builder().clearCapabilities().build();
+        final TestNetworkCallback callback = new TestNetworkCallback();
+        mCm.registerNetworkCallback(request, callback);
+
+        final TestNetworkCallback defaultCallback = new TestNetworkCallback();
+        mCm.registerDefaultNetworkCallback(defaultCallback);
+
+        // Pretend lockdown VPN was configured.
+        setupLegacyLockdownVpn();
+
+        // LockdownVpnTracker disables the Vpn teardown code and enables lockdown.
+        // Check the VPN's state before it does so.
+        assertTrue(mMockVpn.getEnableTeardown());
+        assertFalse(mMockVpn.getLockdown());
+
+        // Send a USER_UNLOCKED broadcast so CS starts LockdownVpnTracker.
+        final int userId = UserHandle.getUserId(Process.myUid());
+        final Intent addedIntent = new Intent(ACTION_USER_UNLOCKED);
+        addedIntent.putExtra(Intent.EXTRA_USER_HANDLE, userId);
+        final Handler handler = new Handler(mCsHandlerThread.getLooper());
+        handler.post(() -> mServiceContext.sendBroadcast(addedIntent));
+        waitForIdle();
+
+        // Lockdown VPN disables teardown and enables lockdown.
+        assertFalse(mMockVpn.getEnableTeardown());
+        assertTrue(mMockVpn.getLockdown());
+
+        // Bring up a network.
+        // Expect nothing to happen because the network does not have an IPv4 default route: legacy
+        // VPN only supports IPv4.
+        final LinkProperties cellLp = new LinkProperties();
+        cellLp.setInterfaceName("rmnet0");
+        cellLp.addLinkAddress(new LinkAddress("2001:db8::1/64"));
+        cellLp.addRoute(new RouteInfo(new IpPrefix("::/0"), null, "rmnet0"));
+        mCellNetworkAgent = new TestNetworkAgentWrapper(TRANSPORT_CELLULAR, cellLp);
+        mCellNetworkAgent.connect(false /* validated */);
+        callback.expectAvailableCallbacksUnvalidatedAndBlocked(mCellNetworkAgent);
+        defaultCallback.expectAvailableCallbacksUnvalidatedAndBlocked(mCellNetworkAgent);
+        waitForIdle();
+        assertNull(mMockVpn.getAgent());
+
+        // Add an IPv4 address. Ideally the VPN should start, but it doesn't because nothing calls
+        // LockdownVpnTracker#handleStateChangedLocked. This is a bug.
+        // TODO: consider fixing this.
+        cellLp.addLinkAddress(new LinkAddress("192.0.2.2/25"));
+        cellLp.addRoute(new RouteInfo(new IpPrefix("0.0.0.0/0"), null, "rmnet0"));
+        mCellNetworkAgent.sendLinkProperties(cellLp);
+        callback.expectCallback(CallbackEntry.LINK_PROPERTIES_CHANGED, mCellNetworkAgent);
+        defaultCallback.expectCallback(CallbackEntry.LINK_PROPERTIES_CHANGED, mCellNetworkAgent);
+        waitForIdle();
+        assertNull(mMockVpn.getAgent());
+
+        // Disconnect, then try again with a network that supports IPv4 at connection time.
+        // Expect lockdown VPN to come up.
+        ExpectedBroadcast b1 = expectConnectivityAction(TYPE_MOBILE, DetailedState.DISCONNECTED);
+        mCellNetworkAgent.disconnect();
+        callback.expectCallback(CallbackEntry.LOST, mCellNetworkAgent);
+        defaultCallback.expectCallback(CallbackEntry.LOST, mCellNetworkAgent);
+        b1.expectBroadcast();
+
+        // When lockdown VPN is active, the NetworkInfo state in CONNECTIVITY_ACTION is overwritten
+        // with the state of the VPN network. So expect a CONNECTING broadcast.
+        b1 = expectConnectivityAction(TYPE_MOBILE, DetailedState.CONNECTING);
+        mCellNetworkAgent = new TestNetworkAgentWrapper(TRANSPORT_CELLULAR, cellLp);
+        mCellNetworkAgent.connect(false /* validated */);
+        callback.expectAvailableCallbacksUnvalidatedAndBlocked(mCellNetworkAgent);
+        defaultCallback.expectAvailableCallbacksUnvalidatedAndBlocked(mCellNetworkAgent);
+        b1.expectBroadcast();
+        assertActiveNetworkInfo(TYPE_MOBILE, DetailedState.BLOCKED);
+        assertNetworkInfo(TYPE_MOBILE, DetailedState.BLOCKED);
+        assertNetworkInfo(TYPE_WIFI, DetailedState.BLOCKED);
+        assertNetworkInfo(TYPE_VPN, DetailedState.BLOCKED);
+
+        // TODO: it would be nice if we could simply rely on the production code here, and have
+        // LockdownVpnTracker start the VPN, have the VPN code register its NetworkAgent with
+        // ConnectivityService, etc. That would require duplicating a fair bit of code from the
+        // Vpn tests around how to mock out LegacyVpnRunner. But even if we did that, this does not
+        // work for at least two reasons:
+        // 1. In this test, calling registerNetworkAgent does not actually result in an agent being
+        //    registered. This is because nothing calls onNetworkMonitorCreated, which is what
+        //    actually ends up causing handleRegisterNetworkAgent to be called. Code in this test
+        //    that wants to register an agent must use TestNetworkAgentWrapper.
+        // 2. Even if we exposed Vpn#agentConnect to the test, and made MockVpn#agentConnect call
+        //    the TestNetworkAgentWrapper code, this would deadlock because the
+        //    TestNetworkAgentWrapper code cannot be called on the handler thread since it calls
+        //    waitForIdle().
+        mMockVpn.expectStartLegacyVpnRunner();
+        b1 = expectConnectivityAction(TYPE_VPN, DetailedState.CONNECTED);
+        ExpectedBroadcast b2 = expectConnectivityAction(TYPE_MOBILE, DetailedState.CONNECTED);
+        mMockVpn.establishForMyUid();
+        callback.expectAvailableThenValidatedCallbacks(mMockVpn);
+        defaultCallback.expectAvailableThenValidatedCallbacks(mMockVpn);
+        b1.expectBroadcast();
+        b2.expectBroadcast();
+        assertActiveNetworkInfo(TYPE_MOBILE, DetailedState.CONNECTED);
+        assertNetworkInfo(TYPE_MOBILE, DetailedState.CONNECTED);
+        assertNetworkInfo(TYPE_WIFI, DetailedState.DISCONNECTED);
+        assertNetworkInfo(TYPE_VPN, DetailedState.CONNECTED);
+
+        // Switch default network from cell to wifi. Expect VPN to disconnect and reconnect.
+        final LinkProperties wifiLp = new LinkProperties();
+        wifiLp.setInterfaceName("wlan0");
+        wifiLp.addLinkAddress(new LinkAddress("192.0.2.163/25"));
+        wifiLp.addRoute(new RouteInfo(new IpPrefix("0.0.0.0/0"), null, "wlan0"));
+        mWiFiNetworkAgent = new TestNetworkAgentWrapper(TRANSPORT_WIFI, wifiLp);
+
+        b1 = expectConnectivityAction(TYPE_MOBILE, DetailedState.DISCONNECTED);
+        // Wifi is CONNECTING because the VPN isn't up yet.
+        b2 = expectConnectivityAction(TYPE_WIFI, DetailedState.CONNECTING);
+        ExpectedBroadcast b3 = expectConnectivityAction(TYPE_VPN, DetailedState.DISCONNECTED);
+        mWiFiNetworkAgent.connect(false /* validated */);
+        b1.expectBroadcast();
+        b2.expectBroadcast();
+        b3.expectBroadcast();
+        mMockVpn.expectStopVpnRunnerPrivileged();
+        mMockVpn.expectStartLegacyVpnRunner();
+
+        // TODO: why is wifi not blocked? Is it because when this callback is sent, the VPN is still
+        // connected, so the network is not considered blocked by the lockdown UID ranges? But the
+        // fact that a VPN is connected should only result in the VPN itself being unblocked, not
+        // any other network. Bug in isUidBlockedByVpn?
+        callback.expectAvailableCallbacksUnvalidated(mWiFiNetworkAgent);
+        callback.expectCapabilitiesThat(mMockVpn, nc -> nc.hasTransport(TRANSPORT_WIFI));
+        callback.expectCallback(CallbackEntry.LOST, mMockVpn);
+        defaultCallback.expectCapabilitiesThat(mMockVpn, nc -> nc.hasTransport(TRANSPORT_WIFI));
+        defaultCallback.expectCallback(CallbackEntry.LOST, mMockVpn);
+        defaultCallback.expectAvailableCallbacksUnvalidatedAndBlocked(mWiFiNetworkAgent);
+
+        // While the VPN is reconnecting on the new network, everything is blocked.
+        assertActiveNetworkInfo(TYPE_WIFI, DetailedState.BLOCKED);
+        assertNetworkInfo(TYPE_MOBILE, DetailedState.BLOCKED);
+        assertNetworkInfo(TYPE_WIFI, DetailedState.BLOCKED);
+        assertNetworkInfo(TYPE_VPN, DetailedState.BLOCKED);
+
+        // The VPN comes up again on wifi.
+        b1 = expectConnectivityAction(TYPE_VPN, DetailedState.CONNECTED);
+        b2 = expectConnectivityAction(TYPE_WIFI, DetailedState.CONNECTED);
+        mMockVpn.establishForMyUid();
+        callback.expectAvailableThenValidatedCallbacks(mMockVpn);
+        defaultCallback.expectAvailableThenValidatedCallbacks(mMockVpn);
+        b1.expectBroadcast();
+        b2.expectBroadcast();
+
+        assertActiveNetworkInfo(TYPE_WIFI, DetailedState.CONNECTED);
+        assertNetworkInfo(TYPE_MOBILE, DetailedState.DISCONNECTED);
+        assertNetworkInfo(TYPE_WIFI, DetailedState.CONNECTED);
+        assertNetworkInfo(TYPE_VPN, DetailedState.CONNECTED);
+
+        // Disconnect cell. Nothing much happens since it's not the default network.
+        // Whenever LockdownVpnTracker is connected, it will send a connected broadcast any time any
+        // NetworkInfo is updated. This is probably a bug.
+        // TODO: consider fixing this.
+        b1 = expectConnectivityAction(TYPE_WIFI, DetailedState.CONNECTED);
+        mCellNetworkAgent.disconnect();
+        b1.expectBroadcast();
+        callback.expectCallback(CallbackEntry.LOST, mCellNetworkAgent);
+        defaultCallback.assertNoCallback();
+
+        assertActiveNetworkInfo(TYPE_WIFI, DetailedState.CONNECTED);
+        assertNetworkInfo(TYPE_MOBILE, DetailedState.DISCONNECTED);
+        assertNetworkInfo(TYPE_WIFI, DetailedState.CONNECTED);
+        assertNetworkInfo(TYPE_VPN, DetailedState.CONNECTED);
+
+        b1 = expectConnectivityAction(TYPE_WIFI, DetailedState.DISCONNECTED);
+        mWiFiNetworkAgent.disconnect();
+        callback.expectCallback(CallbackEntry.LOST, mWiFiNetworkAgent);
+        b1.expectBroadcast();
+        callback.expectCapabilitiesThat(mMockVpn, nc -> !nc.hasTransport(TRANSPORT_WIFI));
+        b2 = expectConnectivityAction(TYPE_VPN, DetailedState.DISCONNECTED);
+        mMockVpn.expectStopVpnRunnerPrivileged();
+        callback.expectCallback(CallbackEntry.LOST, mMockVpn);
+        b2.expectBroadcast();
+    }
+
     @Test
     public final void testLoseTrusted() throws Exception {
         final NetworkRequest trustedRequest = new NetworkRequest.Builder()
@@ -7605,7 +8009,7 @@
         lp.addRoute(new RouteInfo(new IpPrefix(Inet4Address.ANY, 0), null));
         lp.addRoute(new RouteInfo(new IpPrefix(Inet6Address.ANY, 0), RTN_UNREACHABLE));
         // The uid range needs to cover the test app so the network is visible to it.
-        final Set<UidRange> vpnRange = Collections.singleton(UidRange.createForUser(VPN_USER));
+        final Set<UidRange> vpnRange = Collections.singleton(UidRange.createForUser(PRIMARY_USER));
         mMockVpn.establish(lp, VPN_UID, vpnRange);
         assertVpnUidRangesUpdated(true, vpnRange, VPN_UID);
 
@@ -7633,7 +8037,7 @@
         lp.addRoute(new RouteInfo(new IpPrefix(Inet6Address.ANY, 0), null));
         lp.addRoute(new RouteInfo(new IpPrefix(Inet4Address.ANY, 0), null));
         // The uid range needs to cover the test app so the network is visible to it.
-        final Set<UidRange> vpnRange = Collections.singleton(UidRange.createForUser(VPN_USER));
+        final Set<UidRange> vpnRange = Collections.singleton(UidRange.createForUser(PRIMARY_USER));
         mMockVpn.establish(lp, Process.SYSTEM_UID, vpnRange);
         assertVpnUidRangesUpdated(true, vpnRange, Process.SYSTEM_UID);
 
@@ -7649,7 +8053,7 @@
         lp.addRoute(new RouteInfo(new IpPrefix("192.0.2.0/24"), null, "tun0"));
         lp.addRoute(new RouteInfo(new IpPrefix(Inet6Address.ANY, 0), RTN_UNREACHABLE));
         // The uid range needs to cover the test app so the network is visible to it.
-        final Set<UidRange> vpnRange = Collections.singleton(UidRange.createForUser(VPN_USER));
+        final Set<UidRange> vpnRange = Collections.singleton(UidRange.createForUser(PRIMARY_USER));
         mMockVpn.establish(lp, Process.SYSTEM_UID, vpnRange);
         assertVpnUidRangesUpdated(true, vpnRange, Process.SYSTEM_UID);
 
@@ -7664,7 +8068,7 @@
         lp.addRoute(new RouteInfo(new IpPrefix(Inet4Address.ANY, 0), null));
         lp.addRoute(new RouteInfo(new IpPrefix(Inet6Address.ANY, 0), null));
         // The uid range needs to cover the test app so the network is visible to it.
-        final Set<UidRange> vpnRange = Collections.singleton(UidRange.createForUser(VPN_USER));
+        final Set<UidRange> vpnRange = Collections.singleton(UidRange.createForUser(PRIMARY_USER));
         mMockVpn.establish(lp, VPN_UID, vpnRange);
         assertVpnUidRangesUpdated(true, vpnRange, VPN_UID);
 
@@ -7716,7 +8120,7 @@
         lp.addRoute(new RouteInfo(new IpPrefix(Inet4Address.ANY, 0), RTN_UNREACHABLE));
         lp.addRoute(new RouteInfo(new IpPrefix(Inet6Address.ANY, 0), null));
         // The uid range needs to cover the test app so the network is visible to it.
-        final UidRange vpnRange = UidRange.createForUser(VPN_USER);
+        final UidRange vpnRange = UidRange.createForUser(PRIMARY_USER);
         final Set<UidRange> vpnRanges = Collections.singleton(vpnRange);
         mMockVpn.establish(lp, VPN_UID, vpnRanges);
         assertVpnUidRangesUpdated(true, vpnRanges, VPN_UID);
@@ -7781,8 +8185,22 @@
         naExtraInfo.unregister();
     }
 
+    // To avoid granting location permission bypass.
+    private void denyAllLocationPrivilegedPermissions() {
+        mServiceContext.setPermission(NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK,
+                PERMISSION_DENIED);
+        mServiceContext.setPermission(Manifest.permission.NETWORK_SETTINGS,
+                PERMISSION_DENIED);
+        mServiceContext.setPermission(Manifest.permission.NETWORK_STACK,
+                PERMISSION_DENIED);
+        mServiceContext.setPermission(Manifest.permission.NETWORK_SETUP_WIZARD,
+                PERMISSION_DENIED);
+    }
+
     private void setupLocationPermissions(
             int targetSdk, boolean locationToggle, String op, String perm) throws Exception {
+        denyAllLocationPrivilegedPermissions();
+
         final ApplicationInfo applicationInfo = new ApplicationInfo();
         applicationInfo.targetSdkVersion = targetSdk;
         when(mPackageManager.getApplicationInfoAsUser(anyString(), anyInt(), any()))
@@ -7900,7 +8318,7 @@
 
     private void setupConnectionOwnerUid(int vpnOwnerUid, @VpnManager.VpnType int vpnType)
             throws Exception {
-        final Set<UidRange> vpnRange = Collections.singleton(UidRange.createForUser(VPN_USER));
+        final Set<UidRange> vpnRange = Collections.singleton(UidRange.createForUser(PRIMARY_USER));
         mMockVpn.establish(new LinkProperties(), vpnOwnerUid, vpnRange);
         assertVpnUidRangesUpdated(true, vpnRange, vpnOwnerUid);
         mMockVpn.setVpnType(vpnType);
@@ -8104,11 +8522,18 @@
         assertTrue(mService.mConnectivityDiagnosticsCallbacks.containsKey(mIBinder));
     }
 
+    public NetworkAgentInfo fakeMobileNai(NetworkCapabilities nc) {
+        final NetworkInfo info = new NetworkInfo(TYPE_MOBILE, TelephonyManager.NETWORK_TYPE_LTE,
+                ConnectivityManager.getNetworkTypeName(TYPE_MOBILE),
+                TelephonyManager.getNetworkTypeName(TelephonyManager.NETWORK_TYPE_LTE));
+        return new NetworkAgentInfo(null, new Network(NET_ID), info, new LinkProperties(),
+                nc, 0, mServiceContext, null, new NetworkAgentConfig(), mService, null, null, null,
+                0, INVALID_UID, mQosCallbackTracker);
+    }
+
     @Test
     public void testCheckConnectivityDiagnosticsPermissionsNetworkStack() throws Exception {
-        final NetworkAgentInfo naiWithoutUid =
-                new NetworkAgentInfo(null, null, null, null, new NetworkCapabilities(), 0,
-                        mServiceContext, null, null, mService, null, null, null, 0, INVALID_UID);
+        final NetworkAgentInfo naiWithoutUid = fakeMobileNai(new NetworkCapabilities());
 
         mServiceContext.setPermission(
                 android.Manifest.permission.NETWORK_STACK, PERMISSION_GRANTED);
@@ -8121,9 +8546,7 @@
 
     @Test
     public void testCheckConnectivityDiagnosticsPermissionsWrongUidPackageName() throws Exception {
-        final NetworkAgentInfo naiWithoutUid =
-                new NetworkAgentInfo(null, null, null, null, new NetworkCapabilities(), 0,
-                        mServiceContext, null, null, mService, null, null, null, 0, INVALID_UID);
+        final NetworkAgentInfo naiWithoutUid = fakeMobileNai(new NetworkCapabilities());
 
         mServiceContext.setPermission(android.Manifest.permission.NETWORK_STACK, PERMISSION_DENIED);
 
@@ -8136,9 +8559,7 @@
 
     @Test
     public void testCheckConnectivityDiagnosticsPermissionsNoLocationPermission() throws Exception {
-        final NetworkAgentInfo naiWithoutUid =
-                new NetworkAgentInfo(null, null, null, null, new NetworkCapabilities(), 0,
-                        mServiceContext, null, null, mService, null, null, null, 0, INVALID_UID);
+        final NetworkAgentInfo naiWithoutUid = fakeMobileNai(new NetworkCapabilities());
 
         mServiceContext.setPermission(android.Manifest.permission.NETWORK_STACK, PERMISSION_DENIED);
 
@@ -8151,22 +8572,17 @@
 
     @Test
     public void testCheckConnectivityDiagnosticsPermissionsActiveVpn() throws Exception {
-        final Network network = new Network(NET_ID);
-        final NetworkAgentInfo naiWithoutUid =
-                new NetworkAgentInfo(null, network, null, null, new NetworkCapabilities(), 0,
-                        mServiceContext, null, null, mService, null, null, null, 0, INVALID_UID);
-
-        setupLocationPermissions(Build.VERSION_CODES.Q, true, AppOpsManager.OPSTR_FINE_LOCATION,
-                Manifest.permission.ACCESS_FINE_LOCATION);
+        final NetworkAgentInfo naiWithoutUid = fakeMobileNai(new NetworkCapabilities());
 
         mMockVpn.establishForMyUid();
         assertUidRangesUpdatedForMyUid(true);
 
         // Wait for networks to connect and broadcasts to be sent before removing permissions.
         waitForIdle();
-        mServiceContext.setPermission(android.Manifest.permission.NETWORK_STACK, PERMISSION_DENIED);
+        setupLocationPermissions(Build.VERSION_CODES.Q, true, AppOpsManager.OPSTR_FINE_LOCATION,
+                Manifest.permission.ACCESS_FINE_LOCATION);
 
-        assertTrue(mService.setUnderlyingNetworksForVpn(new Network[] {network}));
+        assertTrue(mService.setUnderlyingNetworksForVpn(new Network[] {naiWithoutUid.network}));
         waitForIdle();
         assertTrue(
                 "Active VPN permission not applied",
@@ -8187,9 +8603,7 @@
     public void testCheckConnectivityDiagnosticsPermissionsNetworkAdministrator() throws Exception {
         final NetworkCapabilities nc = new NetworkCapabilities();
         nc.setAdministratorUids(new int[] {Process.myUid()});
-        final NetworkAgentInfo naiWithUid =
-                new NetworkAgentInfo(null, null, null, null, nc, 0, mServiceContext, null, null,
-                        mService, null, null, null, 0, INVALID_UID);
+        final NetworkAgentInfo naiWithUid = fakeMobileNai(nc);
 
         setupLocationPermissions(Build.VERSION_CODES.Q, true, AppOpsManager.OPSTR_FINE_LOCATION,
                 Manifest.permission.ACCESS_FINE_LOCATION);
@@ -8206,9 +8620,7 @@
         final NetworkCapabilities nc = new NetworkCapabilities();
         nc.setOwnerUid(Process.myUid());
         nc.setAdministratorUids(new int[] {Process.myUid()});
-        final NetworkAgentInfo naiWithUid =
-                new NetworkAgentInfo(null, null, null, null, nc, 0, mServiceContext, null, null,
-                        mService, null, null, null, 0, INVALID_UID);
+        final NetworkAgentInfo naiWithUid = fakeMobileNai(nc);
 
         setupLocationPermissions(Build.VERSION_CODES.Q, true, AppOpsManager.OPSTR_FINE_LOCATION,
                 Manifest.permission.ACCESS_FINE_LOCATION);
@@ -8475,7 +8887,7 @@
         lp.setInterfaceName("tun0");
         lp.addRoute(new RouteInfo(new IpPrefix(Inet4Address.ANY, 0), null));
         lp.addRoute(new RouteInfo(new IpPrefix(Inet6Address.ANY, 0), null));
-        final UidRange vpnRange = UidRange.createForUser(VPN_USER);
+        final UidRange vpnRange = UidRange.createForUser(PRIMARY_USER);
         Set<UidRange> vpnRanges = Collections.singleton(vpnRange);
         mMockVpn.establish(lp, VPN_UID, vpnRanges);
         assertVpnUidRangesUpdated(true, vpnRanges, VPN_UID);
@@ -8491,4 +8903,167 @@
         assertVpnUidRangesUpdated(true, newRanges, VPN_UID);
         assertVpnUidRangesUpdated(false, vpnRanges, VPN_UID);
     }
+
+    @Test
+    public void testInvalidRequestTypes() {
+        final int[] invalidReqTypeInts = new int[]{-1, NetworkRequest.Type.NONE.ordinal(),
+                NetworkRequest.Type.LISTEN.ordinal(), NetworkRequest.Type.values().length};
+        final NetworkCapabilities nc = new NetworkCapabilities().addTransportType(TRANSPORT_WIFI);
+
+        for (int reqTypeInt : invalidReqTypeInts) {
+            assertThrows("Expect throws for invalid request type " + reqTypeInt,
+                    IllegalArgumentException.class,
+                    () -> mService.requestNetwork(nc, reqTypeInt, null, 0, null,
+                            ConnectivityManager.TYPE_NONE, mContext.getPackageName(),
+                            getAttributionTag())
+            );
+        }
+    }
+
+    private class QosCallbackMockHelper {
+        @NonNull public final QosFilter mFilter;
+        @NonNull public final IQosCallback mCallback;
+        @NonNull public final TestNetworkAgentWrapper mAgentWrapper;
+        @NonNull private final List<IQosCallback> mCallbacks = new ArrayList();
+
+        QosCallbackMockHelper() throws Exception {
+            Log.d(TAG, "QosCallbackMockHelper: ");
+            mFilter = mock(QosFilter.class);
+
+            // Ensure the network is disconnected before anything else occurs
+            assertNull(mCellNetworkAgent);
+
+            mCellNetworkAgent = new TestNetworkAgentWrapper(TRANSPORT_CELLULAR);
+            mCellNetworkAgent.connect(true);
+
+            verifyActiveNetwork(TRANSPORT_CELLULAR);
+            waitForIdle();
+            final Network network = mCellNetworkAgent.getNetwork();
+
+            final Pair<IQosCallback, IBinder> pair = createQosCallback();
+            mCallback = pair.first;
+
+            when(mFilter.getNetwork()).thenReturn(network);
+            when(mFilter.validate()).thenReturn(QosCallbackException.EX_TYPE_FILTER_NONE);
+            mAgentWrapper = mCellNetworkAgent;
+        }
+
+        void registerQosCallback(@NonNull final QosFilter filter,
+                @NonNull final IQosCallback callback) {
+            mCallbacks.add(callback);
+            final NetworkAgentInfo nai =
+                    mService.getNetworkAgentInfoForNetwork(filter.getNetwork());
+            mService.registerQosCallbackInternal(filter, callback, nai);
+        }
+
+        void tearDown() {
+            for (int i = 0; i < mCallbacks.size(); i++) {
+                mService.unregisterQosCallback(mCallbacks.get(i));
+            }
+        }
+    }
+
+    private Pair<IQosCallback, IBinder> createQosCallback() {
+        final IQosCallback callback = mock(IQosCallback.class);
+        final IBinder binder = mock(Binder.class);
+        when(callback.asBinder()).thenReturn(binder);
+        when(binder.isBinderAlive()).thenReturn(true);
+        return new Pair<>(callback, binder);
+    }
+
+
+    @Test
+    public void testQosCallbackRegistration() throws Exception {
+        mQosCallbackMockHelper = new QosCallbackMockHelper();
+        final NetworkAgentWrapper wrapper = mQosCallbackMockHelper.mAgentWrapper;
+
+        when(mQosCallbackMockHelper.mFilter.validate())
+                .thenReturn(QosCallbackException.EX_TYPE_FILTER_NONE);
+        mQosCallbackMockHelper.registerQosCallback(
+                mQosCallbackMockHelper.mFilter, mQosCallbackMockHelper.mCallback);
+
+        final NetworkAgentWrapper.CallbackType.OnQosCallbackRegister cbRegister1 =
+                (NetworkAgentWrapper.CallbackType.OnQosCallbackRegister)
+                        wrapper.getCallbackHistory().poll(1000, x -> true);
+        assertNotNull(cbRegister1);
+
+        final int registerCallbackId = cbRegister1.mQosCallbackId;
+        mService.unregisterQosCallback(mQosCallbackMockHelper.mCallback);
+        final NetworkAgentWrapper.CallbackType.OnQosCallbackUnregister cbUnregister;
+        cbUnregister = (NetworkAgentWrapper.CallbackType.OnQosCallbackUnregister)
+                wrapper.getCallbackHistory().poll(1000, x -> true);
+        assertNotNull(cbUnregister);
+        assertEquals(registerCallbackId, cbUnregister.mQosCallbackId);
+        assertNull(wrapper.getCallbackHistory().poll(200, x -> true));
+    }
+
+    @Test
+    public void testQosCallbackNoRegistrationOnValidationError() throws Exception {
+        mQosCallbackMockHelper = new QosCallbackMockHelper();
+
+        when(mQosCallbackMockHelper.mFilter.validate())
+                .thenReturn(QosCallbackException.EX_TYPE_FILTER_NETWORK_RELEASED);
+        mQosCallbackMockHelper.registerQosCallback(
+                mQosCallbackMockHelper.mFilter, mQosCallbackMockHelper.mCallback);
+        waitForIdle();
+        verify(mQosCallbackMockHelper.mCallback)
+                .onError(eq(QosCallbackException.EX_TYPE_FILTER_NETWORK_RELEASED));
+    }
+
+    @Test
+    public void testQosCallbackAvailableAndLost() throws Exception {
+        mQosCallbackMockHelper = new QosCallbackMockHelper();
+        final int sessionId = 10;
+        final int qosCallbackId = 1;
+
+        when(mQosCallbackMockHelper.mFilter.validate())
+                .thenReturn(QosCallbackException.EX_TYPE_FILTER_NONE);
+        mQosCallbackMockHelper.registerQosCallback(
+                mQosCallbackMockHelper.mFilter, mQosCallbackMockHelper.mCallback);
+        waitForIdle();
+
+        final EpsBearerQosSessionAttributes attributes = new EpsBearerQosSessionAttributes(
+                1, 2, 3, 4, 5, new ArrayList<>());
+        mQosCallbackMockHelper.mAgentWrapper.getNetworkAgent()
+                .sendQosSessionAvailable(qosCallbackId, sessionId, attributes);
+        waitForIdle();
+
+        verify(mQosCallbackMockHelper.mCallback).onQosEpsBearerSessionAvailable(argThat(session ->
+                session.getSessionId() == sessionId
+                        && session.getSessionType() == QosSession.TYPE_EPS_BEARER), eq(attributes));
+
+        mQosCallbackMockHelper.mAgentWrapper.getNetworkAgent()
+                .sendQosSessionLost(qosCallbackId, sessionId);
+        waitForIdle();
+        verify(mQosCallbackMockHelper.mCallback).onQosSessionLost(argThat(session ->
+                session.getSessionId() == sessionId
+                        && session.getSessionType() == QosSession.TYPE_EPS_BEARER));
+    }
+
+    @Test
+    public void testQosCallbackTooManyRequests() throws Exception {
+        mQosCallbackMockHelper = new QosCallbackMockHelper();
+
+        when(mQosCallbackMockHelper.mFilter.validate())
+                .thenReturn(QosCallbackException.EX_TYPE_FILTER_NONE);
+        for (int i = 0; i < 100; i++) {
+            final Pair<IQosCallback, IBinder> pair = createQosCallback();
+
+            try {
+                mQosCallbackMockHelper.registerQosCallback(
+                        mQosCallbackMockHelper.mFilter, pair.first);
+            } catch (ServiceSpecificException e) {
+                assertEquals(e.errorCode, ConnectivityManager.Errors.TOO_MANY_REQUESTS);
+                if (i < 50) {
+                    fail("TOO_MANY_REQUESTS thrown too early, the count is " + i);
+                }
+
+                // As long as there is at least 50 requests, it is safe to assume it works.
+                // Note: The count isn't being tested precisely against 100 because the counter
+                // is shared with request network.
+                return;
+            }
+        }
+        fail("TOO_MANY_REQUESTS never thrown");
+    }
 }
diff --git a/tests/net/java/com/android/server/connectivity/LingerMonitorTest.java b/tests/net/java/com/android/server/connectivity/LingerMonitorTest.java
index 96c56e3..52cb836 100644
--- a/tests/net/java/com/android/server/connectivity/LingerMonitorTest.java
+++ b/tests/net/java/com/android/server/connectivity/LingerMonitorTest.java
@@ -34,7 +34,9 @@
 import android.net.ConnectivityManager;
 import android.net.IDnsResolver;
 import android.net.INetd;
+import android.net.LinkProperties;
 import android.net.Network;
+import android.net.NetworkAgentConfig;
 import android.net.NetworkCapabilities;
 import android.net.NetworkInfo;
 import android.net.NetworkProvider;
@@ -76,6 +78,7 @@
     @Mock Context mCtx;
     @Mock NetworkNotificationManager mNotifier;
     @Mock Resources mResources;
+    @Mock QosCallbackTracker mQosCallbackTracker;
 
     @Before
     public void setUp() {
@@ -353,9 +356,10 @@
         NetworkCapabilities caps = new NetworkCapabilities();
         caps.addCapability(0);
         caps.addTransportType(transport);
-        NetworkAgentInfo nai = new NetworkAgentInfo(null, new Network(netId), info, null,
-                caps, 50, mCtx, null, null /* config */, mConnService, mNetd, mDnsResolver, mNMS,
-                NetworkProvider.ID_NONE, Binder.getCallingUid());
+        NetworkAgentInfo nai = new NetworkAgentInfo(null, new Network(netId), info,
+                new LinkProperties(), caps, 50, mCtx, null, new NetworkAgentConfig() /* config */,
+                mConnService, mNetd, mDnsResolver, mNMS, NetworkProvider.ID_NONE,
+                Binder.getCallingUid(), mQosCallbackTracker);
         nai.everValidated = true;
         return nai;
     }