diff --git a/core/java/android/net/ConnectivityManager.java b/core/java/android/net/ConnectivityManager.java
index ce0ed5b..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;
@@ -4823,6 +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.
@@ -4832,7 +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,
@@ -4848,4 +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 47c7a1a..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;
@@ -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/Network.java b/core/java/android/net/Network.java
index f98a1f8..fbca7f1 100644
--- a/core/java/android/net/Network.java
+++ b/core/java/android/net/Network.java
@@ -420,7 +420,7 @@
             throw new SocketException("Only AF_INET/AF_INET6 sockets supported");
         }
 
-        final int err = NetworkUtils.bindSocketToNetwork(fd.getInt$(), netId);
+        final int err = NetworkUtils.bindSocketToNetwork(fd, netId);
         if (err != 0) {
             // bindSocketToNetwork returns negative errno.
             throw new ErrnoException("Binding socket to network " + netId, -err)
diff --git a/core/java/android/net/NetworkAgent.java b/core/java/android/net/NetworkAgent.java
index 83a7d16..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;
@@ -227,7 +228,7 @@
      */
     public static final String REDIRECT_URL_KEY = "redirect URL";
 
-     /**
+    /**
      * 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.
@@ -341,6 +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.
@@ -520,6 +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;
+                }
             }
         }
     }
@@ -553,6 +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) {
@@ -639,6 +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));
+        }
     }
 
     /**
@@ -1067,8 +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/NetworkUtils.java b/core/java/android/net/NetworkUtils.java
index b5962c5..8be4af7 100644
--- a/core/java/android/net/NetworkUtils.java
+++ b/core/java/android/net/NetworkUtils.java
@@ -81,11 +81,11 @@
     public native static boolean bindProcessToNetworkForHostResolution(int netId);
 
     /**
-     * Explicitly binds {@code socketfd} to the network designated by {@code netId}.  This
+     * Explicitly binds {@code fd} to the network designated by {@code netId}.  This
      * overrides any binding via {@link #bindProcessToNetwork}.
      * @return 0 on success or negative errno on failure.
      */
-    public native static int bindSocketToNetwork(int socketfd, int netId);
+    public static native int bindSocketToNetwork(FileDescriptor fd, int netId);
 
     /**
      * Protect {@code fd} from VPN connections.  After protecting, data sent through
@@ -93,9 +93,7 @@
      * forwarded through the VPN.
      */
     @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553)
-    public static boolean protectFromVpn(FileDescriptor fd) {
-        return protectFromVpn(fd.getInt$());
-    }
+    public static native boolean protectFromVpn(FileDescriptor fd);
 
     /**
      * Protect {@code socketfd} from VPN connections.  After protecting, data sent through
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..ab55002
--- /dev/null
+++ b/core/java/android/net/QosFilter.java
@@ -0,0 +1,75 @@
+/*
+ * 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.net.InetAddress;
+
+/**
+ * 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();
+
+    /**
+     * Determines whether or not the parameters is a match for the filter.
+     *
+     * @param address the local address
+     * @param startPort the start of the port range
+     * @param endPort the end of the port range
+     * @return whether the parameters match the local address of the filter
+     */
+    public abstract boolean matchesLocalAddress(@NonNull InetAddress address,
+            int startPort, int endPort);
+}
+
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..2080e68
--- /dev/null
+++ b/core/java/android/net/QosSocketFilter.java
@@ -0,0 +1,166 @@
+/*
+ * 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 com.android.internal.annotations.VisibleForTesting;
+
+import java.io.FileDescriptor;
+import java.net.InetAddress;
+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();
+    }
+
+    /**
+     * @inheritDoc
+     */
+    @Override
+    public boolean matchesLocalAddress(@NonNull final InetAddress address, final int startPort,
+            final int endPort) {
+        if (mQosSocketInfo.getLocalSocketAddress() == null) {
+            return false;
+        }
+
+        return matchesLocalAddress(mQosSocketInfo.getLocalSocketAddress(), address, startPort,
+                endPort);
+    }
+
+    /**
+     * Called from {@link QosSocketFilter#matchesLocalAddress(InetAddress, int, int)} with the
+     * filterSocketAddress coming from {@link QosSocketInfo#getLocalSocketAddress()}.
+     * <p>
+     * This method exists for testing purposes since {@link QosSocketInfo} couldn't be mocked
+     * due to being final.
+     *
+     * @param filterSocketAddress the socket address of the filter
+     * @param address the address to compare the filterSocketAddressWith
+     * @param startPort the start of the port range to check
+     * @param endPort the end of the port range to check
+     */
+    @VisibleForTesting
+    public static boolean matchesLocalAddress(@NonNull final InetSocketAddress filterSocketAddress,
+            @NonNull final InetAddress address,
+            final int startPort, final int endPort) {
+        return startPort <= filterSocketAddress.getPort()
+                && endPort >= filterSocketAddress.getPort()
+                && filterSocketAddress.getAddress().equals(address);
+    }
+}
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/jni/android_net_NetUtils.cpp b/core/jni/android_net_NetUtils.cpp
index 2155246..e2af87e 100644
--- a/core/jni/android_net_NetUtils.cpp
+++ b/core/jni/android_net_NetUtils.cpp
@@ -18,6 +18,7 @@
 
 #include <vector>
 
+#include <android/file_descriptor_jni.h>
 #include <arpa/inet.h>
 #include <linux/filter.h>
 #include <linux/if_arp.h>
@@ -83,7 +84,7 @@
         filter_code,
     };
 
-    int fd = jniGetFDFromFileDescriptor(env, javaFd);
+    int fd = AFileDescriptor_getFD(env, javaFd);
     if (setsockopt(fd, SOL_SOCKET, SO_ATTACH_FILTER, &filter, sizeof(filter)) != 0) {
         jniThrowExceptionFmt(env, "java/net/SocketException",
                 "setsockopt(SO_ATTACH_FILTER): %s", strerror(errno));
@@ -93,7 +94,7 @@
 static void android_net_utils_detachBPFFilter(JNIEnv *env, jobject clazz, jobject javaFd)
 {
     int optval_ignored = 0;
-    int fd = jniGetFDFromFileDescriptor(env, javaFd);
+    int fd = AFileDescriptor_getFD(env, javaFd);
     if (setsockopt(fd, SOL_SOCKET, SO_DETACH_FILTER, &optval_ignored, sizeof(optval_ignored)) !=
         0) {
         jniThrowExceptionFmt(env, "java/net/SocketException",
@@ -117,10 +118,9 @@
     return (jboolean) !setNetworkForResolv(netId);
 }
 
-static jint android_net_utils_bindSocketToNetwork(JNIEnv *env, jobject thiz, jint socket,
-        jint netId)
-{
-    return setNetworkForSocket(netId, socket);
+static jint android_net_utils_bindSocketToNetwork(JNIEnv *env, jobject thiz, jobject javaFd,
+                                                  jint netId) {
+    return setNetworkForSocket(netId, AFileDescriptor_getFD(env, javaFd));
 }
 
 static jboolean android_net_utils_protectFromVpn(JNIEnv *env, jobject thiz, jint socket)
@@ -128,6 +128,10 @@
     return (jboolean) !protectFromVpn(socket);
 }
 
+static jboolean android_net_utils_protectFromVpnWithFd(JNIEnv *env, jobject thiz, jobject javaFd) {
+    return android_net_utils_protectFromVpn(env, thiz, AFileDescriptor_getFD(env, javaFd));
+}
+
 static jboolean android_net_utils_queryUserAccess(JNIEnv *env, jobject thiz, jint uid, jint netId)
 {
     return (jboolean) !queryUserAccess(uid, netId);
@@ -178,7 +182,7 @@
 }
 
 static jobject android_net_utils_resNetworkResult(JNIEnv *env, jobject thiz, jobject javaFd) {
-    int fd = jniGetFDFromFileDescriptor(env, javaFd);
+    int fd = AFileDescriptor_getFD(env, javaFd);
     int rcode;
     std::vector<uint8_t> buf(MAXPACKETSIZE, 0);
 
@@ -205,7 +209,7 @@
 }
 
 static void android_net_utils_resNetworkCancel(JNIEnv *env, jobject thiz, jobject javaFd) {
-    int fd = jniGetFDFromFileDescriptor(env, javaFd);
+    int fd = AFileDescriptor_getFD(env, javaFd);
     resNetworkCancel(fd);
     jniSetFileDescriptorOfFD(env, javaFd, -1);
 }
@@ -231,7 +235,7 @@
         return NULL;
     }
 
-    int fd = jniGetFDFromFileDescriptor(env, javaFd);
+    int fd = AFileDescriptor_getFD(env, javaFd);
     struct tcp_repair_window trw = {};
     socklen_t size = sizeof(trw);
 
@@ -271,8 +275,9 @@
     { "bindProcessToNetwork", "(I)Z", (void*) android_net_utils_bindProcessToNetwork },
     { "getBoundNetworkForProcess", "()I", (void*) android_net_utils_getBoundNetworkForProcess },
     { "bindProcessToNetworkForHostResolution", "(I)Z", (void*) android_net_utils_bindProcessToNetworkForHostResolution },
-    { "bindSocketToNetwork", "(II)I", (void*) android_net_utils_bindSocketToNetwork },
-    { "protectFromVpn", "(I)Z", (void*)android_net_utils_protectFromVpn },
+    { "bindSocketToNetwork", "(Ljava/io/FileDescriptor;I)I", (void*) android_net_utils_bindSocketToNetwork },
+    { "protectFromVpn", "(I)Z", (void*) android_net_utils_protectFromVpn },
+    { "protectFromVpn", "(Ljava/io/FileDescriptor;)Z", (void*) android_net_utils_protectFromVpnWithFd },
     { "queryUserAccess", "(II)Z", (void*)android_net_utils_queryUserAccess },
     { "attachDropAllBPFFilter", "(Ljava/io/FileDescriptor;)V", (void*) android_net_utils_attachDropAllBPFFilter },
     { "detachBPFFilter", "(Ljava/io/FileDescriptor;)V", (void*) android_net_utils_detachBPFFilter },
diff --git a/services/core/java/com/android/server/ConnectivityService.java b/services/core/java/com/android/server/ConnectivityService.java
index b07e98f..b999b7e 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;
@@ -204,6 +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;
@@ -279,6 +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.
 
@@ -291,6 +301,8 @@
     @VisibleForTesting
     protected final PermissionMonitor mPermissionMonitor;
 
+    private final PerUidCounter mNetworkRequestCounter;
+
     private KeyStore mKeyStore;
 
     @VisibleForTesting
@@ -313,6 +325,8 @@
     private boolean mRestrictBackground;
 
     private final Context mContext;
+    // The Context is created for UserHandle.ALL.
+    private final Context mUserAllContext;
     private final Dependencies mDeps;
     // 0 is full bad, 100 is full good
     private int mDefaultInetConditionPublished = 0;
@@ -614,6 +628,7 @@
     private final LocationPermissionChecker mLocationPermissionChecker;
 
     private KeepaliveTracker mKeepaliveTracker;
+    private QosCallbackTracker mQosCallbackTracker;
     private NetworkNotificationManager mNotifier;
     private LingerMonitor mLingerMonitor;
 
@@ -858,6 +873,66 @@
     };
 
     /**
+     * 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
@@ -945,6 +1020,7 @@
         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);
@@ -1086,8 +1162,8 @@
         intentFilter.addAction(Intent.ACTION_USER_REMOVED);
         intentFilter.addAction(Intent.ACTION_USER_UNLOCKED);
 
-        final Context userAllContext = mContext.createContextAsUser(UserHandle.ALL, 0 /* flags */);
-        userAllContext.registerReceiver(
+        mUserAllContext = mContext.createContextAsUser(UserHandle.ALL, 0 /* flags */);
+        mUserAllContext.registerReceiver(
                 mIntentReceiver,
                 intentFilter,
                 null /* broadcastPermission */,
@@ -1103,7 +1179,7 @@
         intentFilter.addAction(Intent.ACTION_PACKAGE_REPLACED);
         intentFilter.addAction(Intent.ACTION_PACKAGE_REMOVED);
         intentFilter.addDataScheme("package");
-        userAllContext.registerReceiver(
+        mUserAllContext.registerReceiver(
                 mIntentReceiver,
                 intentFilter,
                 null /* broadcastPermission */,
@@ -1112,7 +1188,7 @@
         // Listen to lockdown VPN reset.
         intentFilter = new IntentFilter();
         intentFilter.addAction(LockdownVpnTracker.ACTION_LOCKDOWN_RESET);
-        userAllContext.registerReceiver(
+        mUserAllContext.registerReceiver(
                 mIntentReceiver, intentFilter, NETWORK_STACK, mHandler);
 
         mNetworkActivityTracker = new LegacyNetworkActivityTracker(mContext, mNMS);
@@ -1125,6 +1201,7 @@
 
         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,
@@ -1381,9 +1458,8 @@
             return;
         }
         final String action = blocked ? "BLOCKED" : "UNBLOCKED";
-        final NetworkRequest satisfiedRequest = nri.getSatisfiedRequest();
-        final int requestId =  satisfiedRequest != null
-                ? satisfiedRequest.requestId : nri.mRequests.get(0).requestId;
+        final int requestId = nri.getActiveRequest() != null
+                ? nri.getActiveRequest().requestId : nri.mRequests.get(0).requestId;
         mNetworkInfoBlockingLogs.log(String.format(
                 "%s %d(%d) on netId %d", action, nri.mUid, requestId, net.getNetId()));
     }
@@ -2275,7 +2351,7 @@
                 intent.addFlags(Intent.FLAG_RECEIVER_VISIBLE_TO_INSTANT_APPS);
             }
             try {
-                mContext.sendStickyBroadcastAsUser(intent, UserHandle.ALL, options);
+                mUserAllContext.sendStickyBroadcast(intent, options);
             } finally {
                 Binder.restoreCallingIdentity(ident);
             }
@@ -2653,7 +2729,7 @@
     @VisibleForTesting
     NetworkRequestInfo[] requestsSortedById() {
         NetworkRequestInfo[] requests = new NetworkRequestInfo[0];
-        requests = mNetworkRequests.values().toArray(requests);
+        requests = getNrisFromGlobalRequests().toArray(requests);
         // Sort the array based off the NRI containing the min requestId in its requests.
         Arrays.sort(requests,
                 Comparator.comparingInt(nri -> Collections.min(nri.mRequests,
@@ -2777,6 +2853,7 @@
                         updateCapabilitiesForNetwork(nai);
                         notifyIfacesChangedForNetworkStats();
                     }
+                    break;
                 }
             }
         }
@@ -3338,6 +3415,8 @@
         // 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);
@@ -3355,10 +3434,10 @@
         for (int i = 0; i < nai.numNetworkRequests(); i++) {
             NetworkRequest request = nai.requestAt(i);
             final NetworkRequestInfo nri = mNetworkRequests.get(request);
-            final NetworkAgentInfo currentNetwork = nri.mSatisfier;
+            final NetworkAgentInfo currentNetwork = nri.getSatisfier();
             if (currentNetwork != null
                     && currentNetwork.network.getNetId() == nai.network.getNetId()) {
-                nri.mSatisfier = null;
+                nri.setSatisfier(null, null);
                 sendUpdatedScoreToFactories(request, null);
             }
         }
@@ -3436,42 +3515,63 @@
         return null;
     }
 
-    private void handleRegisterNetworkRequestWithIntent(Message msg) {
+    private void handleRegisterNetworkRequestWithIntent(@NonNull final Message msg) {
         final NetworkRequestInfo nri = (NetworkRequestInfo) (msg.obj);
-
-        NetworkRequestInfo existingRequest = findExistingNetworkRequestInfo(nri.mPendingIntent);
+        // handleRegisterNetworkRequestWithIntent() doesn't apply to multilayer requests.
+        ensureNotMultilayerRequest(nri, "handleRegisterNetworkRequestWithIntent");
+        final NetworkRequestInfo existingRequest =
+                findExistingNetworkRequestInfo(nri.mPendingIntent);
         if (existingRequest != null) { // remove the existing request.
-            if (DBG) log("Replacing " + existingRequest.request + " with "
-                    + nri.request + " because their intents matched.");
-            handleReleaseNetworkRequest(existingRequest.request, getCallingUid(),
+            if (DBG) {
+                log("Replacing " + existingRequest.mRequests.get(0) + " with "
+                        + nri.mRequests.get(0) + " because their intents matched.");
+            }
+            handleReleaseNetworkRequest(existingRequest.mRequests.get(0), getCallingUid(),
                     /* callOnUnavailable */ false);
         }
         handleRegisterNetworkRequest(nri);
     }
 
-    private void handleRegisterNetworkRequest(NetworkRequestInfo nri) {
+    private void handleRegisterNetworkRequest(@NonNull final NetworkRequestInfo nri) {
         ensureRunningOnConnectivityServiceThread();
-        mNetworkRequests.put(nri.request, nri);
         mNetworkRequestInfoLogs.log("REGISTER " + nri);
-        if (nri.request.isListen()) {
-            for (NetworkAgentInfo network : mNetworkAgentInfos) {
-                if (nri.request.networkCapabilities.hasSignalStrength() &&
-                        network.satisfiesImmutableCapabilitiesOf(nri.request)) {
-                    updateSignalStrengthThresholds(network, "REGISTER", nri.request);
+        for (final NetworkRequest req : nri.mRequests) {
+            mNetworkRequests.put(req, nri);
+            if (req.isListen()) {
+                for (final NetworkAgentInfo network : mNetworkAgentInfos) {
+                    if (req.networkCapabilities.hasSignalStrength()
+                            && network.satisfiesImmutableCapabilitiesOf(req)) {
+                        updateSignalStrengthThresholds(network, "REGISTER", req);
+                    }
                 }
             }
         }
         rematchAllNetworksAndRequests();
-        if (nri.request.isRequest() && nri.mSatisfier == null) {
-            sendUpdatedScoreToFactories(nri.request, null);
+        // If an active request exists, return as its score has already been sent if needed.
+        if (null != nri.getActiveRequest()) {
+            return;
+        }
+
+        // As this request was not satisfied on rematch and thus never had any scores sent to the
+        // factories, send null now for each request of type REQUEST.
+        for (final NetworkRequest req : nri.mRequests) {
+            if (!req.isRequest()) {
+                continue;
+            }
+            sendUpdatedScoreToFactories(req, null);
         }
     }
 
-    private void handleReleaseNetworkRequestWithIntent(PendingIntent pendingIntent,
-            int callingUid) {
-        NetworkRequestInfo nri = findExistingNetworkRequestInfo(pendingIntent);
+    private void handleReleaseNetworkRequestWithIntent(@NonNull final PendingIntent pendingIntent,
+            final int callingUid) {
+        final NetworkRequestInfo nri = findExistingNetworkRequestInfo(pendingIntent);
         if (nri != null) {
-            handleReleaseNetworkRequest(nri.request, callingUid, /* callOnUnavailable */ false);
+            // handleReleaseNetworkRequestWithIntent() paths don't apply to multilayer requests.
+            ensureNotMultilayerRequest(nri, "handleReleaseNetworkRequestWithIntent");
+            handleReleaseNetworkRequest(
+                    nri.mRequests.get(0),
+                    callingUid,
+                    /* callOnUnavailable */ false);
         }
     }
 
@@ -3525,6 +3625,11 @@
             return false;
         }
         for (final NetworkRequest req : nri.mRequests) {
+            // This multilayer listen request is satisfied therefore no further requests need to be
+            // evaluated deeming this network not a potential satisfier.
+            if (req.isListen() && nri.getActiveRequest() == req) {
+                return false;
+            }
             // As non-multilayer listen requests have already returned, the below would only happen
             // for a multilayer request therefore continue to the next request if available.
             if (req.isListen()) {
@@ -3545,7 +3650,7 @@
                         // 2. Unvalidated WiFi will not be reaped when validated cellular
                         //    is currently satisfying the request.  This is desirable when
                         //    WiFi ends up validating and out scoring cellular.
-                        || nri.mSatisfier.getCurrentScore()
+                        || nri.getSatisfier().getCurrentScore()
                         < candidate.getCurrentScoreAsValidated();
                 return isNetworkNeeded;
             }
@@ -3570,30 +3675,45 @@
         return nri;
     }
 
-    private void handleTimedOutNetworkRequest(final NetworkRequestInfo nri) {
-        ensureRunningOnConnectivityServiceThread();
-        if (mNetworkRequests.get(nri.request) == null) {
-            return;
+    private void ensureNotMultilayerRequest(@NonNull final NetworkRequestInfo nri,
+            final String callingMethod) {
+        if (nri.isMultilayerRequest()) {
+            throw new IllegalStateException(
+                    callingMethod + " does not support multilayer requests.");
         }
-        if (nri.mSatisfier != null) {
-            return;
-        }
-        if (VDBG || (DBG && nri.request.isRequest())) {
-            log("releasing " + nri.request + " (timeout)");
-        }
-        handleRemoveNetworkRequest(nri);
-        callCallbackForRequest(nri, null, ConnectivityManager.CALLBACK_UNAVAIL, 0);
     }
 
-    private void handleReleaseNetworkRequest(NetworkRequest request, int callingUid,
-            boolean callOnUnavailable) {
+    private void handleTimedOutNetworkRequest(@NonNull final NetworkRequestInfo nri) {
+        ensureRunningOnConnectivityServiceThread();
+        // handleTimedOutNetworkRequest() is part of the requestNetwork() flow which works off of a
+        // single NetworkRequest and thus does not apply to multilayer requests.
+        ensureNotMultilayerRequest(nri, "handleTimedOutNetworkRequest");
+        if (mNetworkRequests.get(nri.mRequests.get(0)) == null) {
+            return;
+        }
+        if (nri.getSatisfier() != null) {
+            return;
+        }
+        if (VDBG || (DBG && nri.mRequests.get(0).isRequest())) {
+            log("releasing " + nri.mRequests.get(0) + " (timeout)");
+        }
+        handleRemoveNetworkRequest(nri);
+        callCallbackForRequest(
+                nri, null, ConnectivityManager.CALLBACK_UNAVAIL, 0);
+    }
+
+    private void handleReleaseNetworkRequest(@NonNull final NetworkRequest request,
+            final int callingUid,
+            final boolean callOnUnavailable) {
         final NetworkRequestInfo nri =
                 getNriForAppRequest(request, callingUid, "release NetworkRequest");
         if (nri == null) {
             return;
         }
-        if (VDBG || (DBG && nri.request.isRequest())) {
-            log("releasing " + nri.request + " (release request)");
+        // handleReleaseNetworkRequest() paths don't apply to multilayer requests.
+        ensureNotMultilayerRequest(nri, "handleReleaseNetworkRequest");
+        if (VDBG || (DBG && request.isRequest())) {
+            log("releasing " + request + " (release request)");
         }
         handleRemoveNetworkRequest(nri);
         if (callOnUnavailable) {
@@ -3601,42 +3721,88 @@
         }
     }
 
-    private void handleRemoveNetworkRequest(final NetworkRequestInfo nri) {
+    private void handleRemoveNetworkRequest(@NonNull final NetworkRequestInfo nri) {
         ensureRunningOnConnectivityServiceThread();
 
         nri.unlinkDeathRecipient();
-        mNetworkRequests.remove(nri.request);
-
-        decrementNetworkRequestPerUidCount(nri);
-
+        for (final NetworkRequest req : nri.mRequests) {
+            mNetworkRequests.remove(req);
+            if (req.isListen()) {
+                removeListenRequestFromNetworks(req);
+            }
+        }
+        mNetworkRequestCounter.decrementCount(nri.mUid);
         mNetworkRequestInfoLogs.log("RELEASE " + nri);
-        if (nri.request.isRequest()) {
-            boolean wasKept = false;
-            final NetworkAgentInfo nai = nri.mSatisfier;
-            if (nai != null) {
-                boolean wasBackgroundNetwork = nai.isBackgroundNetwork();
-                nai.removeRequest(nri.request.requestId);
-                if (VDBG || DDBG) {
-                    log(" Removing from current network " + nai.toShortString()
-                            + ", leaving " + nai.numNetworkRequests() + " requests.");
-                }
-                // If there are still lingered requests on this network, don't tear it down,
-                // but resume lingering instead.
-                final long now = SystemClock.elapsedRealtime();
-                if (updateLingerState(nai, now)) {
-                    notifyNetworkLosing(nai, now);
-                }
-                if (unneeded(nai, UnneededFor.TEARDOWN)) {
-                    if (DBG) log("no live requests for " + nai.toShortString() + "; disconnecting");
-                    teardownUnneededNetwork(nai);
-                } else {
-                    wasKept = true;
-                }
-                nri.mSatisfier = null;
-                if (!wasBackgroundNetwork && nai.isBackgroundNetwork()) {
-                    // Went from foreground to background.
-                    updateCapabilitiesForNetwork(nai);
-                }
+
+        if (null != nri.getActiveRequest()) {
+            if (nri.getActiveRequest().isRequest()) {
+                removeSatisfiedNetworkRequestFromNetwork(nri);
+            } else {
+                nri.setSatisfier(null, null);
+            }
+        }
+
+        cancelNpiRequests(nri);
+    }
+
+    private void cancelNpiRequests(@NonNull final NetworkRequestInfo nri) {
+        for (final NetworkRequest req : nri.mRequests) {
+            cancelNpiRequest(req);
+        }
+    }
+
+    private void cancelNpiRequest(@NonNull final NetworkRequest req) {
+        if (req.isRequest()) {
+            for (final NetworkProviderInfo npi : mNetworkProviderInfos.values()) {
+                npi.cancelRequest(req);
+            }
+        }
+    }
+
+    private void removeListenRequestFromNetworks(@NonNull final NetworkRequest req) {
+        // listens don't have a singular affected Network. Check all networks to see
+        // if this listen request applies and remove it.
+        for (final NetworkAgentInfo nai : mNetworkAgentInfos) {
+            nai.removeRequest(req.requestId);
+            if (req.networkCapabilities.hasSignalStrength()
+                    && nai.satisfiesImmutableCapabilitiesOf(req)) {
+                updateSignalStrengthThresholds(nai, "RELEASE", req);
+            }
+        }
+    }
+
+    /**
+     * Remove a NetworkRequestInfo's satisfied request from its 'satisfier' (NetworkAgentInfo) and
+     * manage the necessary upkeep (linger, teardown networks, etc.) when doing so.
+     * @param nri the NetworkRequestInfo to disassociate from its current NetworkAgentInfo
+     */
+    private void removeSatisfiedNetworkRequestFromNetwork(@NonNull final NetworkRequestInfo nri) {
+        boolean wasKept = false;
+        final NetworkAgentInfo nai = nri.getSatisfier();
+        if (nai != null) {
+            final int requestLegacyType = nri.getActiveRequest().legacyType;
+            final boolean wasBackgroundNetwork = nai.isBackgroundNetwork();
+            nai.removeRequest(nri.getActiveRequest().requestId);
+            if (VDBG || DDBG) {
+                log(" Removing from current network " + nai.toShortString()
+                        + ", leaving " + nai.numNetworkRequests() + " requests.");
+            }
+            // If there are still lingered requests on this network, don't tear it down,
+            // but resume lingering instead.
+            final long now = SystemClock.elapsedRealtime();
+            if (updateLingerState(nai, now)) {
+                notifyNetworkLosing(nai, now);
+            }
+            if (unneeded(nai, UnneededFor.TEARDOWN)) {
+                if (DBG) log("no live requests for " + nai.toShortString() + "; disconnecting");
+                teardownUnneededNetwork(nai);
+            } else {
+                wasKept = true;
+            }
+            nri.setSatisfier(null, null);
+            if (!wasBackgroundNetwork && nai.isBackgroundNetwork()) {
+                // Went from foreground to background.
+                updateCapabilitiesForNetwork(nai);
             }
 
             // Maintain the illusion.  When this request arrived, we might have pretended
@@ -3644,15 +3810,15 @@
             // connected.  Now that this request has gone away, we might have to pretend
             // that the network disconnected.  LegacyTypeTracker will generate that
             // phantom disconnect for this type.
-            if (nri.request.legacyType != TYPE_NONE && nai != null) {
+            if (requestLegacyType != TYPE_NONE) {
                 boolean doRemove = true;
                 if (wasKept) {
                     // check if any of the remaining requests for this network are for the
                     // same legacy type - if so, don't remove the nai
                     for (int i = 0; i < nai.numNetworkRequests(); i++) {
                         NetworkRequest otherRequest = nai.requestAt(i);
-                        if (otherRequest.legacyType == nri.request.legacyType &&
-                                otherRequest.isRequest()) {
+                        if (otherRequest.legacyType == requestLegacyType
+                                && otherRequest.isRequest()) {
                             if (DBG) log(" still have other legacy request - leaving");
                             doRemove = false;
                         }
@@ -3660,36 +3826,9 @@
                 }
 
                 if (doRemove) {
-                    mLegacyTypeTracker.remove(nri.request.legacyType, nai, false);
+                    mLegacyTypeTracker.remove(requestLegacyType, nai, false);
                 }
             }
-
-            for (NetworkProviderInfo npi : mNetworkProviderInfos.values()) {
-                npi.cancelRequest(nri.request);
-            }
-        } else {
-            // listens don't have a singular affectedNetwork.  Check all networks to see
-            // if this listen request applies and remove it.
-            for (NetworkAgentInfo nai : mNetworkAgentInfos) {
-                nai.removeRequest(nri.request.requestId);
-                if (nri.request.networkCapabilities.hasSignalStrength() &&
-                        nai.satisfiesImmutableCapabilitiesOf(nri.request)) {
-                    updateSignalStrengthThresholds(nai, "RELEASE", nri.request);
-                }
-            }
-        }
-    }
-
-    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);
-            }
         }
     }
 
@@ -4519,6 +4658,10 @@
         Log.w(TAG, s);
     }
 
+    private static void logwtf(String s) {
+        Log.wtf(TAG, s);
+    }
+
     private static void loge(String s) {
         Log.e(TAG, s);
     }
@@ -5261,11 +5404,6 @@
     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;
@@ -5351,18 +5489,38 @@
 
     /**
      * Tracks info about the requester.
-     * Also used to notice when the calling process dies so we can self-expire
+     * Also used to notice when the calling process dies so as to self-expire
      */
     @VisibleForTesting
     protected class NetworkRequestInfo implements IBinder.DeathRecipient {
         final List<NetworkRequest> mRequests;
-        final NetworkRequest request;
+
+        // mSatisfier and mActiveRequest rely on one another therefore set them together.
+        void setSatisfier(
+                @Nullable final NetworkAgentInfo satisfier,
+                @Nullable final NetworkRequest activeRequest) {
+            mSatisfier = satisfier;
+            mActiveRequest = activeRequest;
+        }
 
         // The network currently satisfying this request, or null if none. Must only be touched
         // on the handler thread. This only makes sense for network requests and not for listens,
         // as defined by NetworkRequest#isRequest(). For listens, this is always null.
         @Nullable
-        NetworkAgentInfo mSatisfier;
+        private NetworkAgentInfo mSatisfier;
+        NetworkAgentInfo getSatisfier() {
+            return mSatisfier;
+        }
+
+        // The request in mRequests assigned to a network agent. This is null if none of the
+        // requests in mRequests can be satisfied. This member has the constraint of only being
+        // accessible on the handler thread.
+        @Nullable
+        private NetworkRequest mActiveRequest;
+        NetworkRequest getActiveRequest() {
+            return mActiveRequest;
+        }
+
         final PendingIntent mPendingIntent;
         boolean mPendingIntentSent;
         private final IBinder mBinder;
@@ -5371,7 +5529,6 @@
         final Messenger messenger;
 
         NetworkRequestInfo(NetworkRequest r, PendingIntent pi) {
-            request = r;
             mRequests = initializeRequests(r);
             ensureAllNetworkRequestsHaveType(mRequests);
             mPendingIntent = pi;
@@ -5379,20 +5536,19 @@
             mBinder = null;
             mPid = getCallingPid();
             mUid = mDeps.getCallingUid();
-            enforceRequestCountLimit();
+            mNetworkRequestCounter.incrementCountOrThrow(mUid);
         }
 
         NetworkRequestInfo(Messenger m, NetworkRequest r, IBinder binder) {
             super();
             messenger = m;
-            request = r;
             mRequests = initializeRequests(r);
             ensureAllNetworkRequestsHaveType(mRequests);
             mBinder = binder;
             mPid = getCallingPid();
             mUid = mDeps.getCallingUid();
             mPendingIntent = null;
-            enforceRequestCountLimit();
+            mNetworkRequestCounter.incrementCountOrThrow(mUid);
 
             try {
                 mBinder.linkToDeath(this, 0);
@@ -5415,31 +5571,6 @@
             return Collections.unmodifiableList(tempRequests);
         }
 
-        private NetworkRequest getSatisfiedRequest() {
-            if (mSatisfier == null) {
-                return null;
-            }
-
-            for (NetworkRequest req : mRequests) {
-                if (mSatisfier.isSatisfyingRequest(req.requestId)) {
-                    return req;
-                }
-            }
-
-            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);
@@ -5486,6 +5617,10 @@
     private int[] getSignalStrengthThresholds(@NonNull final NetworkAgentInfo nai) {
         final SortedSet<Integer> thresholds = new TreeSet<>();
         synchronized (nai) {
+            // mNetworkRequests may contain the same value multiple times in case of
+            // multilayer requests. It won't matter in this case because the thresholds
+            // will then be the same and be deduplicated as they enter the `thresholds` set.
+            // TODO : have mNetworkRequests be a Set<NetworkRequestInfo> or the like.
             for (final NetworkRequestInfo nri : mNetworkRequests.values()) {
                 for (final NetworkRequest req : nri.mRequests) {
                     if (req.networkCapabilities.hasSignalStrength()
@@ -5661,9 +5796,14 @@
             // 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);
         }
     }
 
@@ -5856,13 +5996,19 @@
     }
 
     @Override
-    public void declareNetworkRequestUnfulfillable(NetworkRequest request) {
+    public void declareNetworkRequestUnfulfillable(@NonNull final NetworkRequest request) {
         if (request.hasTransport(TRANSPORT_TEST)) {
             enforceNetworkFactoryOrTestNetworksPermission();
         } else {
             enforceNetworkFactoryPermission();
         }
-        mHandler.post(() -> handleReleaseNetworkRequest(request, mDeps.getCallingUid(), true));
+        final NetworkRequestInfo nri = mNetworkRequests.get(request);
+        if (nri != null) {
+            // declareNetworkRequestUnfulfillable() paths don't apply to multilayer requests.
+            ensureNotMultilayerRequest(nri, "declareNetworkRequestUnfulfillable");
+            mHandler.post(() -> handleReleaseNetworkRequest(
+                    nri.mRequests.get(0), mDeps.getCallingUid(), true));
+        }
     }
 
     // NOTE: Accessed on multiple threads, must be synchronized on itself.
@@ -5998,7 +6144,7 @@
         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);
@@ -6787,6 +6933,39 @@
         }
     }
 
+    private void sendUpdatedScoreToFactories(
+            @NonNull final NetworkReassignment.RequestReassignment event) {
+        // If a request of type REQUEST is now being satisfied by a new network.
+        if (null != event.mNewNetworkRequest && event.mNewNetworkRequest.isRequest()) {
+            sendUpdatedScoreToFactories(event.mNewNetworkRequest, event.mNewNetwork);
+        }
+
+        // If a previously satisfied request of type REQUEST is no longer being satisfied.
+        if (null != event.mOldNetworkRequest && event.mOldNetworkRequest.isRequest()
+                && event.mOldNetworkRequest != event.mNewNetworkRequest) {
+            sendUpdatedScoreToFactories(event.mOldNetworkRequest, null);
+        }
+
+        cancelMultilayerLowerPriorityNpiRequests(event.mNetworkRequestInfo);
+    }
+
+    /**
+     *  Cancel with all NPIs the given NRI's multilayer requests that are a lower priority than
+     *  its currently satisfied active request.
+     * @param nri the NRI to cancel lower priority requests for.
+     */
+    private void cancelMultilayerLowerPriorityNpiRequests(
+            @NonNull final NetworkRequestInfo nri) {
+        if (!nri.isMultilayerRequest() || null == nri.mActiveRequest) {
+            return;
+        }
+
+        final int indexOfNewRequest = nri.mRequests.indexOf(nri.mActiveRequest);
+        for (int i = indexOfNewRequest + 1; i < nri.mRequests.size(); i++) {
+            cancelNpiRequest(nri.mRequests.get(i));
+        }
+    }
+
     private void sendUpdatedScoreToFactories(@NonNull NetworkRequest networkRequest,
             @Nullable NetworkAgentInfo nai) {
         final int score;
@@ -6807,21 +6986,35 @@
     }
 
     /** Sends all current NetworkRequests to the specified factory. */
-    private void sendAllRequestsToProvider(NetworkProviderInfo npi) {
+    private void sendAllRequestsToProvider(@NonNull final NetworkProviderInfo npi) {
         ensureRunningOnConnectivityServiceThread();
-        for (NetworkRequestInfo nri : mNetworkRequests.values()) {
-            if (nri.request.isListen()) continue;
-            NetworkAgentInfo nai = nri.mSatisfier;
-            final int score;
-            final int serial;
-            if (nai != null) {
-                score = nai.getCurrentScore();
-                serial = nai.factorySerialNumber;
-            } else {
-                score = 0;
-                serial = NetworkProvider.ID_NONE;
+        for (final NetworkRequestInfo nri : getNrisFromGlobalRequests()) {
+            for (final NetworkRequest req : nri.mRequests) {
+                if (req.isListen() && nri.getActiveRequest() == req) {
+                    break;
+                }
+                if (req.isListen()) {
+                    continue;
+                }
+                // Only set the nai for the request it is satisfying.
+                final NetworkAgentInfo nai =
+                        nri.getActiveRequest() == req ? nri.getSatisfier() : null;
+                final int score;
+                final int serial;
+                if (null != nai) {
+                    score = nai.getCurrentScore();
+                    serial = nai.factorySerialNumber;
+                } else {
+                    score = 0;
+                    serial = NetworkProvider.ID_NONE;
+                }
+                npi.requestNetwork(req, score, serial);
+                // For multilayer requests, don't send lower priority requests if a higher priority
+                // request is already satisfied.
+                if (null != nai) {
+                    break;
+                }
             }
-            npi.requestNetwork(nri.request, score, serial);
         }
     }
 
@@ -6830,7 +7023,12 @@
         if (notificationType == ConnectivityManager.CALLBACK_AVAILABLE && !nri.mPendingIntentSent) {
             Intent intent = new Intent();
             intent.putExtra(ConnectivityManager.EXTRA_NETWORK, networkAgent.network);
-            intent.putExtra(ConnectivityManager.EXTRA_NETWORK_REQUEST, nri.request);
+            // If apps could file multi-layer requests with PendingIntents, they'd need to know
+            // which of the layer is satisfied alongside with some ID for the request. Hence, if
+            // such an API is ever implemented, there is no doubt the right request to send in
+            // EXTRA_NETWORK_REQUEST is mActiveRequest, and whatever ID would be added would need to
+            // be sent as a separate extra.
+            intent.putExtra(ConnectivityManager.EXTRA_NETWORK_REQUEST, nri.getActiveRequest());
             nri.mPendingIntentSent = true;
             sendIntent(nri.mPendingIntent, intent);
         }
@@ -6860,8 +7058,9 @@
         releasePendingNetworkRequestWithDelay(pendingIntent);
     }
 
-    private void callCallbackForRequest(NetworkRequestInfo nri,
-            NetworkAgentInfo networkAgent, int notificationType, int arg1) {
+    private void callCallbackForRequest(@NonNull final NetworkRequestInfo nri,
+            @NonNull final NetworkAgentInfo networkAgent, final int notificationType,
+            final int arg1) {
         if (nri.messenger == null) {
             // Default request has no msgr. Also prevents callbacks from being invoked for
             // NetworkRequestInfos registered with ConnectivityDiagnostics requests. Those callbacks
@@ -6869,8 +7068,14 @@
             return;
         }
         Bundle bundle = new Bundle();
+        // In the case of multi-layer NRIs, the first request is not necessarily the one that
+        // is satisfied. This is vexing, but the ConnectivityManager code that receives this
+        // callback is only using the request as a token to identify the callback, so it doesn't
+        // matter too much at this point as long as the callback can be found.
+        // TODO b/177608132: make sure callbacks are indexed by NRIs and not NetworkRequest objects.
         // TODO: check if defensive copies of data is needed.
-        putParcelable(bundle, new NetworkRequest(nri.request));
+        final NetworkRequest nrForCallback = new NetworkRequest(nri.mRequests.get(0));
+        putParcelable(bundle, nrForCallback);
         Message msg = Message.obtain();
         if (notificationType != ConnectivityManager.CALLBACK_UNAVAIL) {
             putParcelable(bundle, networkAgent.network);
@@ -6883,7 +7088,7 @@
                 putParcelable(
                         bundle,
                         createWithLocationInfoSanitizedIfNecessaryWhenParceled(
-                                nc, nri.mUid, nri.request.getRequestorPackageName()));
+                                nc, nri.mUid, nrForCallback.getRequestorPackageName()));
                 putParcelable(bundle, linkPropertiesRestrictedForCallerPermissions(
                         networkAgent.linkProperties, nri.mPid, nri.mUid));
                 // For this notification, arg1 contains the blocked status.
@@ -6902,7 +7107,7 @@
                 putParcelable(
                         bundle,
                         createWithLocationInfoSanitizedIfNecessaryWhenParceled(
-                                netCap, nri.mUid, nri.request.getRequestorPackageName()));
+                                netCap, nri.mUid, nrForCallback.getRequestorPackageName()));
                 break;
             }
             case ConnectivityManager.CALLBACK_IP_CHANGED: {
@@ -6921,12 +7126,12 @@
         try {
             if (VDBG) {
                 String notification = ConnectivityManager.getCallbackName(notificationType);
-                log("sending notification " + notification + " for " + nri.request);
+                log("sending notification " + notification + " for " + nrForCallback);
             }
             nri.messenger.send(msg);
         } catch (RemoteException e) {
             // may occur naturally in the race of binder death.
-            loge("RemoteException caught trying to send a callback msg for " + nri.request);
+            loge("RemoteException caught trying to send a callback msg for " + nrForCallback);
         }
     }
 
@@ -7002,19 +7207,25 @@
     }
 
     private void processNewlyLostListenRequests(@NonNull final NetworkAgentInfo nai) {
-        for (NetworkRequestInfo nri : mNetworkRequests.values()) {
-            NetworkRequest nr = nri.request;
+        for (final NetworkRequestInfo nri : mNetworkRequests.values()) {
+            if (nri.isMultilayerRequest()) {
+                continue;
+            }
+            final NetworkRequest nr = nri.mRequests.get(0);
             if (!nr.isListen()) continue;
             if (nai.isSatisfyingRequest(nr.requestId) && !nai.satisfies(nr)) {
-                nai.removeRequest(nri.request.requestId);
+                nai.removeRequest(nr.requestId);
                 callCallbackForRequest(nri, nai, ConnectivityManager.CALLBACK_LOST, 0);
             }
         }
     }
 
     private void processNewlySatisfiedListenRequests(@NonNull final NetworkAgentInfo nai) {
-        for (NetworkRequestInfo nri : mNetworkRequests.values()) {
-            NetworkRequest nr = nri.request;
+        for (final NetworkRequestInfo nri : mNetworkRequests.values()) {
+            if (nri.isMultilayerRequest()) {
+                continue;
+            }
+            final NetworkRequest nr = nri.mRequests.get(0);
             if (!nr.isListen()) continue;
             if (nai.satisfies(nr) && !nai.isSatisfyingRequest(nr.requestId)) {
                 nai.addRequest(nr);
@@ -7026,19 +7237,25 @@
     // An accumulator class to gather the list of changes that result from a rematch.
     private static class NetworkReassignment {
         static class RequestReassignment {
-            @NonNull public final NetworkRequestInfo mRequest;
+            @NonNull public final NetworkRequestInfo mNetworkRequestInfo;
+            @NonNull public final NetworkRequest mOldNetworkRequest;
+            @NonNull public final NetworkRequest mNewNetworkRequest;
             @Nullable public final NetworkAgentInfo mOldNetwork;
             @Nullable public final NetworkAgentInfo mNewNetwork;
-            RequestReassignment(@NonNull final NetworkRequestInfo request,
+            RequestReassignment(@NonNull final NetworkRequestInfo networkRequestInfo,
+                    @NonNull final NetworkRequest oldNetworkRequest,
+                    @NonNull final NetworkRequest newNetworkRequest,
                     @Nullable final NetworkAgentInfo oldNetwork,
                     @Nullable final NetworkAgentInfo newNetwork) {
-                mRequest = request;
+                mNetworkRequestInfo = networkRequestInfo;
+                mOldNetworkRequest = oldNetworkRequest;
+                mNewNetworkRequest = newNetworkRequest;
                 mOldNetwork = oldNetwork;
                 mNewNetwork = newNetwork;
             }
 
             public String toString() {
-                return mRequest.mRequests.get(0).requestId + " : "
+                return mNetworkRequestInfo.mRequests.get(0).requestId + " : "
                         + (null != mOldNetwork ? mOldNetwork.network.getNetId() : "null")
                         + " → " + (null != mNewNetwork ? mNewNetwork.network.getNetId() : "null");
             }
@@ -7056,7 +7273,7 @@
                 // sure this stays true, but without imposing this expensive check on all
                 // reassignments on all user devices.
                 for (final RequestReassignment existing : mReassignments) {
-                    if (existing.mRequest.equals(reassignment.mRequest)) {
+                    if (existing.mNetworkRequestInfo.equals(reassignment.mNetworkRequestInfo)) {
                         throw new IllegalStateException("Trying to reassign ["
                                 + reassignment + "] but already have ["
                                 + existing + "]");
@@ -7071,7 +7288,7 @@
         @Nullable
         private RequestReassignment getReassignment(@NonNull final NetworkRequestInfo nri) {
             for (final RequestReassignment event : getRequestReassignments()) {
-                if (nri == event.mRequest) return event;
+                if (nri == event.mNetworkRequestInfo) return event;
             }
             return null;
         }
@@ -7098,6 +7315,8 @@
     }
 
     private void updateSatisfiersForRematchRequest(@NonNull final NetworkRequestInfo nri,
+            @NonNull final NetworkRequest previousRequest,
+            @NonNull final NetworkRequest newRequest,
             @Nullable final NetworkAgentInfo previousSatisfier,
             @Nullable final NetworkAgentInfo newSatisfier,
             final long now) {
@@ -7107,58 +7326,98 @@
                 if (VDBG || DDBG) {
                     log("   accepting network in place of " + previousSatisfier.toShortString());
                 }
-                previousSatisfier.removeRequest(nri.request.requestId);
-                previousSatisfier.lingerRequest(nri.request.requestId, now, mLingerDelayMs);
+                previousSatisfier.removeRequest(previousRequest.requestId);
+                previousSatisfier.lingerRequest(previousRequest.requestId, now, mLingerDelayMs);
             } else {
                 if (VDBG || DDBG) log("   accepting network in place of null");
             }
-            newSatisfier.unlingerRequest(nri.request.requestId);
-            if (!newSatisfier.addRequest(nri.request)) {
+            newSatisfier.unlingerRequest(newRequest.requestId);
+            if (!newSatisfier.addRequest(newRequest)) {
                 Log.wtf(TAG, "BUG: " + newSatisfier.toShortString() + " already has "
-                        + nri.request);
+                        + newRequest);
             }
         } else {
             if (DBG) {
                 log("Network " + previousSatisfier.toShortString() + " stopped satisfying"
-                        + " request " + nri.request.requestId);
+                        + " request " + previousRequest.requestId);
             }
-            previousSatisfier.removeRequest(nri.request.requestId);
+            previousSatisfier.removeRequest(previousRequest.requestId);
         }
-        nri.mSatisfier = newSatisfier;
+        nri.setSatisfier(newSatisfier, newRequest);
     }
 
+    /**
+     * This function is triggered when something can affect what network should satisfy what
+     * request, and it computes the network reassignment from the passed collection of requests to
+     * network match to the one that the system should now have. That data is encoded in an
+     * object that is a list of changes, each of them having an NRI, and old satisfier, and a new
+     * satisfier.
+     *
+     * After the reassignment is computed, it is applied to the state objects.
+     *
+     * @param networkRequests the nri objects to evaluate for possible network reassignment
+     * @return NetworkReassignment listing of proposed network assignment changes
+     */
     @NonNull
-    private NetworkReassignment computeNetworkReassignment() {
-        ensureRunningOnConnectivityServiceThread();
+    private NetworkReassignment computeNetworkReassignment(
+            @NonNull final Collection<NetworkRequestInfo> networkRequests) {
         final NetworkReassignment changes = new NetworkReassignment();
 
         // Gather the list of all relevant agents and sort them by score.
         final ArrayList<NetworkAgentInfo> nais = new ArrayList<>();
         for (final NetworkAgentInfo nai : mNetworkAgentInfos) {
-            if (!nai.everConnected) continue;
+            if (!nai.everConnected) {
+                continue;
+            }
             nais.add(nai);
         }
 
-        for (final NetworkRequestInfo nri : mNetworkRequests.values()) {
-            if (nri.request.isListen()) continue;
-            final NetworkAgentInfo bestNetwork = mNetworkRanker.getBestNetwork(nri.request, nais);
+        for (final NetworkRequestInfo nri : networkRequests) {
+            // Non-multilayer listen requests can be ignored.
+            if (!nri.isMultilayerRequest() && nri.mRequests.get(0).isListen()) {
+                continue;
+            }
+            NetworkAgentInfo bestNetwork = null;
+            NetworkRequest bestRequest = null;
+            for (final NetworkRequest req : nri.mRequests) {
+                bestNetwork = mNetworkRanker.getBestNetwork(req, nais);
+                // Stop evaluating as the highest possible priority request is satisfied.
+                if (null != bestNetwork) {
+                    bestRequest = req;
+                    break;
+                }
+            }
             if (bestNetwork != nri.mSatisfier) {
                 // bestNetwork may be null if no network can satisfy this request.
                 changes.addRequestReassignment(new NetworkReassignment.RequestReassignment(
-                        nri, nri.mSatisfier, bestNetwork));
+                        nri, nri.mActiveRequest, bestRequest, nri.getSatisfier(), bestNetwork));
             }
         }
         return changes;
     }
 
+    private Set<NetworkRequestInfo> getNrisFromGlobalRequests() {
+        return new HashSet<>(mNetworkRequests.values());
+    }
+
     /**
-     * Attempt to rematch all Networks with NetworkRequests.  This may result in Networks
+     * Attempt to rematch all Networks with all NetworkRequests.  This may result in Networks
      * being disconnected.
      */
     private void rematchAllNetworksAndRequests() {
+        rematchNetworksAndRequests(getNrisFromGlobalRequests());
+    }
+
+    /**
+     * Attempt to rematch all Networks with given NetworkRequests.  This may result in Networks
+     * being disconnected.
+     */
+    private void rematchNetworksAndRequests(
+            @NonNull final Set<NetworkRequestInfo> networkRequests) {
+        ensureRunningOnConnectivityServiceThread();
         // TODO: This may be slow, and should be optimized.
         final long now = SystemClock.elapsedRealtime();
-        final NetworkReassignment changes = computeNetworkReassignment();
+        final NetworkReassignment changes = computeNetworkReassignment(networkRequests);
         if (VDBG || DDBG) {
             log(changes.debugString());
         } else if (DBG) {
@@ -7183,8 +7442,10 @@
         // the linger status.
         for (final NetworkReassignment.RequestReassignment event :
                 changes.getRequestReassignments()) {
-            updateSatisfiersForRematchRequest(event.mRequest, event.mOldNetwork,
-                    event.mNewNetwork, now);
+            updateSatisfiersForRematchRequest(event.mNetworkRequestInfo,
+                    event.mOldNetworkRequest, event.mNewNetworkRequest,
+                    event.mOldNetwork, event.mNewNetwork,
+                    now);
         }
 
         final NetworkAgentInfo oldDefaultNetwork = getDefaultNetwork();
@@ -7236,12 +7497,12 @@
             // trying to connect if they know they cannot match it.
             // TODO - this could get expensive if there are a lot of outstanding requests for this
             // network. Think of a way to reduce this. Push netid->request mapping to each factory?
-            sendUpdatedScoreToFactories(event.mRequest.request, event.mNewNetwork);
+            sendUpdatedScoreToFactories(event);
 
             if (null != event.mNewNetwork) {
-                notifyNetworkAvailable(event.mNewNetwork, event.mRequest);
+                notifyNetworkAvailable(event.mNewNetwork, event.mNetworkRequestInfo);
             } else {
-                callCallbackForRequest(event.mRequest, event.mOldNetwork,
+                callCallbackForRequest(event.mNetworkRequestInfo, event.mOldNetwork,
                         ConnectivityManager.CALLBACK_LOST, 0);
             }
         }
@@ -8278,7 +8539,7 @@
             // 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;
         }
 
@@ -8344,7 +8605,7 @@
         // 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);
     }
@@ -8565,7 +8826,7 @@
         private final INetworkManagementService mNMS;
 
         LegacyNetworkActivityTracker(@NonNull Context context,
-                        @NonNull INetworkManagementService nms) {
+                @NonNull INetworkManagementService nms) {
             mContext = context;
             mNMS = nms;
             try {
@@ -8584,7 +8845,7 @@
                         sendDataActivityBroadcast(transportTypeToLegacyType(transportType), active,
                                 tsNanos);
                     }
-        };
+                };
 
         // This is deprecated and only to support legacy use cases.
         private int transportTypeToLegacyType(int type) {
@@ -8694,4 +8955,53 @@
             }
         }
     }
+    /**
+     * 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/NetworkAgentInfo.java b/services/core/java/com/android/server/connectivity/NetworkAgentInfo.java
index e3663ba..ab0360b 100644
--- a/services/core/java/com/android/server/connectivity/NetworkAgentInfo.java
+++ b/services/core/java/com/android/server/connectivity/NetworkAgentInfo.java
@@ -36,12 +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.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;
@@ -321,18 +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;
@@ -346,6 +353,7 @@
         networkAgentConfig = config;
         this.factorySerialNumber = factorySerialNumber;
         this.creatorUid = creatorUid;
+        mQosCallbackTracker = qosCallbackTracker;
     }
 
     private class AgentDeathMonitor implements IBinder.DeathRecipient {
@@ -531,6 +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;
@@ -584,6 +617,23 @@
             mHandler.obtainMessage(NetworkAgent.EVENT_UNDERLYING_NETWORKS_CHANGED,
                     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);
+        }
     }
 
     /**
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/integration/src/com/android/server/net/integrationtests/ConnectivityServiceIntegrationTest.kt b/tests/net/integration/src/com/android/server/net/integrationtests/ConnectivityServiceIntegrationTest.kt
index 16c4865..083c8c8 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
@@ -38,6 +38,7 @@
 import android.os.ConditionVariable
 import android.os.IBinder
 import android.os.INetworkManagementService
+import android.os.UserHandle
 import android.testing.TestableContext
 import android.util.Log
 import androidx.test.ext.junit.runners.AndroidJUnit4
@@ -55,10 +56,13 @@
 import org.junit.BeforeClass
 import org.junit.Test
 import org.junit.runner.RunWith
+import org.mockito.AdditionalAnswers
 import org.mockito.Mock
 import org.mockito.Mockito.any
+import org.mockito.Mockito.anyInt
 import org.mockito.Mockito.doNothing
 import org.mockito.Mockito.doReturn
+import org.mockito.Mockito.eq
 import org.mockito.Mockito.mock
 import org.mockito.Mockito.spy
 import org.mockito.MockitoAnnotations
@@ -143,7 +147,10 @@
     @Before
     fun setUp() {
         MockitoAnnotations.initMocks(this)
-        doNothing().`when`(context).sendStickyBroadcastAsUser(any(), any(), any())
+        val asUserCtx = mock(Context::class.java, AdditionalAnswers.delegatesTo<Context>(context))
+        doReturn(UserHandle.ALL).`when`(asUserCtx).user
+        doReturn(asUserCtx).`when`(context).createContextAsUser(eq(UserHandle.ALL), anyInt())
+        doNothing().`when`(context).sendStickyBroadcast(any(), any())
 
         networkStackClient = TestNetworkStackClient(realContext)
         networkStackClient.init()
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/android/net/NetworkTemplateTest.kt b/tests/net/java/android/net/NetworkTemplateTest.kt
index 9ba56e4..91fcbc0 100644
--- a/tests/net/java/android/net/NetworkTemplateTest.kt
+++ b/tests/net/java/android/net/NetworkTemplateTest.kt
@@ -67,6 +67,7 @@
         val caps = NetworkCapabilities().apply {
             setCapability(NetworkCapabilities.NET_CAPABILITY_NOT_METERED, false)
             setCapability(NetworkCapabilities.NET_CAPABILITY_NOT_ROAMING, true)
+            setSSID(ssid)
         }
         return NetworkState(info, lp, caps, mock(Network::class.java), subscriberId, ssid)
     }
diff --git a/tests/net/java/android/net/QosSocketFilterTest.java b/tests/net/java/android/net/QosSocketFilterTest.java
new file mode 100644
index 0000000..ad58960
--- /dev/null
+++ b/tests/net/java/android/net/QosSocketFilterTest.java
@@ -0,0 +1,75 @@
+/*
+ * 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 junit.framework.Assert.assertFalse;
+import static junit.framework.Assert.assertTrue;
+
+import androidx.test.runner.AndroidJUnit4;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import java.net.InetAddress;
+import java.net.InetSocketAddress;
+
+@RunWith(AndroidJUnit4.class)
+@androidx.test.filters.SmallTest
+public class QosSocketFilterTest {
+
+    @Test
+    public void testPortExactMatch() {
+        final InetAddress addressA = InetAddresses.parseNumericAddress("1.2.3.4");
+        final InetAddress addressB = InetAddresses.parseNumericAddress("1.2.3.4");
+        assertTrue(QosSocketFilter.matchesLocalAddress(
+                new InetSocketAddress(addressA, 10), addressB, 10, 10));
+
+    }
+
+    @Test
+    public void testPortLessThanStart() {
+        final InetAddress addressA = InetAddresses.parseNumericAddress("1.2.3.4");
+        final InetAddress addressB = InetAddresses.parseNumericAddress("1.2.3.4");
+        assertFalse(QosSocketFilter.matchesLocalAddress(
+                new InetSocketAddress(addressA, 8), addressB, 10, 10));
+    }
+
+    @Test
+    public void testPortGreaterThanEnd() {
+        final InetAddress addressA = InetAddresses.parseNumericAddress("1.2.3.4");
+        final InetAddress addressB = InetAddresses.parseNumericAddress("1.2.3.4");
+        assertFalse(QosSocketFilter.matchesLocalAddress(
+                new InetSocketAddress(addressA, 18), addressB, 10, 10));
+    }
+
+    @Test
+    public void testPortBetweenStartAndEnd() {
+        final InetAddress addressA = InetAddresses.parseNumericAddress("1.2.3.4");
+        final InetAddress addressB = InetAddresses.parseNumericAddress("1.2.3.4");
+        assertTrue(QosSocketFilter.matchesLocalAddress(
+                new InetSocketAddress(addressA, 10), addressB, 8, 18));
+    }
+
+    @Test
+    public void testAddressesDontMatch() {
+        final InetAddress addressA = InetAddresses.parseNumericAddress("1.2.3.4");
+        final InetAddress addressB = InetAddresses.parseNumericAddress("1.2.3.5");
+        assertFalse(QosSocketFilter.matchesLocalAddress(
+                new InetSocketAddress(addressA, 10), addressB, 10, 10));
+    }
+}
+
diff --git a/tests/net/java/com/android/server/ConnectivityServiceTest.java b/tests/net/java/com/android/server/ConnectivityServiceTest.java
index 37307a4..f893e9e 100644
--- a/tests/net/java/com/android/server/ConnectivityServiceTest.java
+++ b/tests/net/java/com/android/server/ConnectivityServiceTest.java
@@ -167,6 +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;
@@ -190,6 +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;
@@ -218,6 +222,7 @@
 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;
@@ -226,10 +231,12 @@
 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;
@@ -251,6 +258,7 @@
 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;
@@ -368,6 +376,8 @@
     private WrappedMultinetworkPolicyTracker mPolicyTracker;
     private HandlerThread mAlarmManagerThread;
     private TestNetIdManager mNetIdManager;
+    private QosCallbackMockHelper mQosCallbackMockHelper;
+    private QosCallbackTracker mQosCallbackTracker;
 
     @Mock DeviceIdleInternal mDeviceIdleInternal;
     @Mock INetworkManagementService mNetworkManagementService;
@@ -1395,6 +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);
@@ -1470,6 +1481,11 @@
             mEthernetNetworkAgent.disconnect();
             mEthernetNetworkAgent = null;
         }
+
+        if (mQosCallbackMockHelper != null) {
+            mQosCallbackMockHelper.tearDown();
+            mQosCallbackMockHelper = null;
+        }
         mMockVpn.disconnect();
         waitForIdle();
 
@@ -4379,7 +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()));
         }
@@ -8512,7 +8528,7 @@
                 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);
+                0, INVALID_UID, mQosCallbackTracker);
     }
 
     @Test
@@ -8890,7 +8906,7 @@
 
     @Test
     public void testInvalidRequestTypes() {
-        final int[] invalidReqTypeInts = new int[] {-1, NetworkRequest.Type.NONE.ordinal(),
+        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);
 
@@ -8903,4 +8919,151 @@
             );
         }
     }
+
+    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 4d151af..52cb836 100644
--- a/tests/net/java/com/android/server/connectivity/LingerMonitorTest.java
+++ b/tests/net/java/com/android/server/connectivity/LingerMonitorTest.java
@@ -78,6 +78,7 @@
     @Mock Context mCtx;
     @Mock NetworkNotificationManager mNotifier;
     @Mock Resources mResources;
+    @Mock QosCallbackTracker mQosCallbackTracker;
 
     @Before
     public void setUp() {
@@ -358,7 +359,7 @@
         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());
+                Binder.getCallingUid(), mQosCallbackTracker);
         nai.everValidated = true;
         return nai;
     }
diff --git a/tests/net/java/com/android/server/net/NetworkStatsServiceTest.java b/tests/net/java/com/android/server/net/NetworkStatsServiceTest.java
index c783629..19f9641 100644
--- a/tests/net/java/com/android/server/net/NetworkStatsServiceTest.java
+++ b/tests/net/java/com/android/server/net/NetworkStatsServiceTest.java
@@ -21,7 +21,6 @@
 import static android.net.ConnectivityManager.TYPE_MOBILE;
 import static android.net.ConnectivityManager.TYPE_VPN;
 import static android.net.ConnectivityManager.TYPE_WIFI;
-import static android.net.ConnectivityManager.TYPE_WIMAX;
 import static android.net.NetworkStats.DEFAULT_NETWORK_ALL;
 import static android.net.NetworkStats.DEFAULT_NETWORK_NO;
 import static android.net.NetworkStats.DEFAULT_NETWORK_YES;
@@ -44,6 +43,7 @@
 import static android.net.NetworkTemplate.NETWORK_TYPE_ALL;
 import static android.net.NetworkTemplate.buildTemplateMobileAll;
 import static android.net.NetworkTemplate.buildTemplateMobileWithRatType;
+import static android.net.NetworkTemplate.buildTemplateWifi;
 import static android.net.NetworkTemplate.buildTemplateWifiWildcard;
 import static android.net.TrafficStats.MB_IN_BYTES;
 import static android.net.TrafficStats.UID_REMOVED;
@@ -146,7 +146,7 @@
     private static final String IMSI_2 = "310260";
     private static final String TEST_SSID = "AndroidAP";
 
-    private static NetworkTemplate sTemplateWifi = buildTemplateWifiWildcard();
+    private static NetworkTemplate sTemplateWifi = buildTemplateWifi(TEST_SSID);
     private static NetworkTemplate sTemplateImsi1 = buildTemplateMobileAll(IMSI_1);
     private static NetworkTemplate sTemplateImsi2 = buildTemplateMobileAll(IMSI_2);
 
@@ -291,7 +291,6 @@
         // verify service has empty history for wifi
         assertNetworkTotal(sTemplateWifi, 0L, 0L, 0L, 0L, 0);
 
-
         // modify some number on wifi, and trigger poll event
         incrementCurrentTime(HOUR_IN_MILLIS);
         expectDefaultSettings();
@@ -567,61 +566,6 @@
     }
 
     @Test
-    public void testUid3gWimaxCombinedByTemplate() throws Exception {
-        // pretend that network comes online
-        expectDefaultSettings();
-        NetworkState[] states = new NetworkState[] {buildMobile3gState(IMSI_1)};
-        expectNetworkStatsSummary(buildEmptyStats());
-        expectNetworkStatsUidDetail(buildEmptyStats());
-
-        mService.forceUpdateIfaces(NETWORKS_MOBILE, states, getActiveIface(states), new VpnInfo[0]);
-
-        // create some traffic
-        incrementCurrentTime(HOUR_IN_MILLIS);
-        expectDefaultSettings();
-        expectNetworkStatsSummary(buildEmptyStats());
-        expectNetworkStatsUidDetail(new NetworkStats(getElapsedRealtime(), 1)
-                .insertEntry(TEST_IFACE, UID_RED, SET_DEFAULT, TAG_NONE, 1024L, 8L, 1024L, 8L, 0L)
-                .insertEntry(TEST_IFACE, UID_RED, SET_DEFAULT, 0xF00D, 512L, 4L, 512L, 4L, 0L));
-        mService.incrementOperationCount(UID_RED, 0xF00D, 5);
-
-        forcePollAndWaitForIdle();
-
-        // verify service recorded history
-        assertUidTotal(sTemplateImsi1, UID_RED, 1024L, 8L, 1024L, 8L, 5);
-
-
-        // now switch over to wimax network
-        incrementCurrentTime(HOUR_IN_MILLIS);
-        expectDefaultSettings();
-        states = new NetworkState[] {buildWimaxState(TEST_IFACE2)};
-        expectNetworkStatsSummary(buildEmptyStats());
-        expectNetworkStatsUidDetail(new NetworkStats(getElapsedRealtime(), 1)
-                .insertEntry(TEST_IFACE, UID_RED, SET_DEFAULT, TAG_NONE, 1024L, 8L, 1024L, 8L, 0L)
-                .insertEntry(TEST_IFACE, UID_RED, SET_DEFAULT, 0xF00D, 512L, 4L, 512L, 4L, 0L));
-
-        mService.forceUpdateIfaces(NETWORKS_MOBILE, states, getActiveIface(states), new VpnInfo[0]);
-        forcePollAndWaitForIdle();
-
-
-        // create traffic on second network
-        incrementCurrentTime(HOUR_IN_MILLIS);
-        expectDefaultSettings();
-        expectNetworkStatsSummary(buildEmptyStats());
-        expectNetworkStatsUidDetail(new NetworkStats(getElapsedRealtime(), 1)
-                .insertEntry(TEST_IFACE, UID_RED, SET_DEFAULT, TAG_NONE, 1024L, 8L, 1024L, 8L, 0L)
-                .insertEntry(TEST_IFACE, UID_RED, SET_DEFAULT, 0xF00D, 512L, 4L, 512L, 4L, 0L)
-                .insertEntry(TEST_IFACE2, UID_RED, SET_DEFAULT, TAG_NONE, 512L, 4L, 256L, 2L, 0L)
-                .insertEntry(TEST_IFACE2, UID_RED, SET_DEFAULT, 0xFAAD, 512L, 4L, 256L, 2L, 0L));
-        mService.incrementOperationCount(UID_RED, 0xFAAD, 5);
-
-        forcePollAndWaitForIdle();
-
-        // verify that ALL_MOBILE template combines both
-        assertUidTotal(sTemplateImsi1, UID_RED, 1536L, 12L, 1280L, 10L, 10);
-    }
-
-    @Test
     public void testMobileStatsByRatType() throws Exception {
         final NetworkTemplate template3g =
                 buildTemplateMobileWithRatType(null, TelephonyManager.NETWORK_TYPE_UMTS);
@@ -1503,6 +1447,7 @@
         capabilities.setCapability(NetworkCapabilities.NET_CAPABILITY_NOT_METERED, !isMetered);
         capabilities.setCapability(NetworkCapabilities.NET_CAPABILITY_NOT_ROAMING, true);
         capabilities.addTransportType(NetworkCapabilities.TRANSPORT_WIFI);
+        capabilities.setSSID(TEST_SSID);
         return new NetworkState(info, prop, capabilities, WIFI_NETWORK, null, TEST_SSID);
     }
 
@@ -1524,17 +1469,6 @@
         return new NetworkState(info, prop, capabilities, MOBILE_NETWORK, subscriberId, null);
     }
 
-    private static NetworkState buildWimaxState(@NonNull String iface) {
-        final NetworkInfo info = new NetworkInfo(TYPE_WIMAX, 0, null, null);
-        info.setDetailedState(DetailedState.CONNECTED, null, null);
-        final LinkProperties prop = new LinkProperties();
-        prop.setInterfaceName(iface);
-        final NetworkCapabilities capabilities = new NetworkCapabilities();
-        capabilities.setCapability(NetworkCapabilities.NET_CAPABILITY_NOT_METERED, false);
-        capabilities.setCapability(NetworkCapabilities.NET_CAPABILITY_NOT_ROAMING, true);
-        return new NetworkState(info, prop, capabilities, MOBILE_NETWORK, null, null);
-    }
-
     private NetworkStats buildEmptyStats() {
         return new NetworkStats(getElapsedRealtime(), 0);
     }