content: /*
   * Copyright 2018 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.telephony.data;
  
  import android.annotation.NonNull;
  import android.annotation.SystemApi;
  import android.app.Service;
  import android.content.Intent;
  import android.os.Handler;
  import android.os.HandlerThread;
  import android.os.IBinder;
  import android.os.Looper;
  import android.os.Message;
  import android.os.RemoteException;
  import android.telephony.AccessNetworkConstants.AccessNetworkType;
  import android.telephony.Rlog;
  import android.telephony.data.ApnSetting.ApnType;
  import android.util.SparseArray;
  
  import com.android.internal.annotations.VisibleForTesting;
  
  import java.util.List;
  
  /**
   * Base class of the qualified networks service, which is a vendor service providing up-to-date
   * qualified network information to the frameworks for data handover control. A qualified network
   * is defined as an access network that is ready for bringing up data connection for given APN
   * types.
   *
   * Services that extend QualifiedNetworksService must register the service in their AndroidManifest
   * to be detected by the framework. They must be protected by the permission
   * "android.permission.BIND_TELEPHONY_DATA_SERVICE". The qualified networks service definition in
   * the manifest must follow the following format:
   * ...
   * <service android:name=".xxxQualifiedNetworksService"
   *     android:permission="android.permission.BIND_TELEPHONY_DATA_SERVICE" >
   *     <intent-filter>
   *         <action android:name="android.telephony.data.QualifiedNetworksService" />
   *     </intent-filter>
   * </service>
   * @hide
   */
  @SystemApi
  public abstract class QualifiedNetworksService extends Service {
      private static final String TAG = QualifiedNetworksService.class.getSimpleName();
  
      public static final String QUALIFIED_NETWORKS_SERVICE_INTERFACE =
              "android.telephony.data.QualifiedNetworksService";
  
      private static final int QNS_CREATE_NETWORK_AVAILABILITY_PROVIDER               = 1;
      private static final int QNS_REMOVE_NETWORK_AVAILABILITY_PROVIDER               = 2;
      private static final int QNS_REMOVE_ALL_NETWORK_AVAILABILITY_PROVIDERS          = 3;
      private static final int QNS_UPDATE_QUALIFIED_NETWORKS                          = 4;
  
      private final HandlerThread mHandlerThread;
  
      private final QualifiedNetworksServiceHandler mHandler;
  
      private final SparseArray<NetworkAvailabilityProvider> mProviders = new SparseArray<>();
  
      /** @hide */
      @VisibleForTesting
      public final IQualifiedNetworksServiceWrapper mBinder = new IQualifiedNetworksServiceWrapper();
  
      /**
       * The abstract class of the network availability provider implementation. The vendor qualified
       * network service must extend this class to report the available networks for data
       * connection setup. Note that each instance of network availability provider is associated with
       * one physical SIM slot.
       */
      public abstract class NetworkAvailabilityProvider implements AutoCloseable {
          private final int mSlotIndex;
  
          private IQualifiedNetworksServiceCallback mCallback;
  
          /**
           * Qualified networks for each APN type. Key is the {@link ApnType}, value is the array
           * of available networks.
           */
          private SparseArray<int[]> mQualifiedNetworkTypesList = new SparseArray<>();
  
          /**
           * Constructor
           * @param slotIndex SIM slot index the network availability provider associated with.
           */
          public NetworkAvailabilityProvider(int slotIndex) {
              mSlotIndex = slotIndex;
          }
  
          /**
           * @return SIM slot index the network availability provider associated with.
           */
          public final int getSlotIndex() {
              return mSlotIndex;
          }
  
          private void registerForQualifiedNetworkTypesChanged(
                  IQualifiedNetworksServiceCallback callback) {
              mCallback = callback;
  
              // Force sending the qualified networks upon registered.
              if (mCallback != null) {
                  for (int i = 0; i < mQualifiedNetworkTypesList.size(); i++) {
                      try {
                          mCallback.onQualifiedNetworkTypesChanged(
                                  mQualifiedNetworkTypesList.keyAt(i),
                                  mQualifiedNetworkTypesList.valueAt(i));
                      } catch (RemoteException e) {
                          loge("Failed to call onQualifiedNetworksChanged. " + e);
                      }
                  }
              }
          }
  
          /**
           * Update the qualified networks list. Network availability provider must invoke this method
           * whenever the qualified networks changes. If this method is never invoked for certain
           * APN types, then frameworks will always use the default (i.e. cellular) data and network
           * service.
           *
           * @param apnTypes APN types of the qualified networks. This must be a bitmask combination
           * of {@link ApnSetting.ApnType}.
           * @param qualifiedNetworkTypes List of network types which are qualified for data
           * connection setup for {@link @apnType} in the preferred order. Each element in the list
           * is a {@link AccessNetworkType}. An empty list indicates no networks are qualified
           * for data setup.
           */
          public final void updateQualifiedNetworkTypes(
                  @ApnType int apnTypes, @NonNull List<Integer> qualifiedNetworkTypes) {
              int[] qualifiedNetworkTypesArray =
                      qualifiedNetworkTypes.stream().mapToInt(i->i).toArray();
              mHandler.obtainMessage(QNS_UPDATE_QUALIFIED_NETWORKS, mSlotIndex, apnTypes,
                      qualifiedNetworkTypesArray).sendToTarget();
          }
  
          private void onUpdateQualifiedNetworkTypes(@ApnType int apnTypes,
                                                     int[] qualifiedNetworkTypes) {
              mQualifiedNetworkTypesList.put(apnTypes, qualifiedNetworkTypes);
              if (mCallback != null) {
                  try {
                      mCallback.onQualifiedNetworkTypesChanged(apnTypes, qualifiedNetworkTypes);
                  } catch (RemoteException e) {
                      loge("Failed to call onQualifiedNetworksChanged. " + e);
                  }
              }
          }
  
          /**
           * Called when the qualified networks provider is removed. The extended class should
           * implement this method to perform cleanup works.
           */
          @Override
          public abstract void close();
      }
  
      private class QualifiedNetworksServiceHandler extends Handler {
          QualifiedNetworksServiceHandler(Looper looper) {
              super(looper);
          }
  
          @Override
          public void handleMessage(Message message) {
              IQualifiedNetworksServiceCallback callback;
              final int slotIndex = message.arg1;
              NetworkAvailabilityProvider provider = mProviders.get(slotIndex);
  
              switch (message.what) {
                  case QNS_CREATE_NETWORK_AVAILABILITY_PROVIDER:
                      if (mProviders.get(slotIndex) != null) {
                          loge("Network availability provider for slot " + slotIndex
                                  + " already existed.");
                          return;
                      }
  
                      provider = onCreateNetworkAvailabilityProvider(slotIndex);
                      if (provider != null) {
                          mProviders.put(slotIndex, provider);
  
                          callback = (IQualifiedNetworksServiceCallback) message.obj;
                          provider.registerForQualifiedNetworkTypesChanged(callback);
                      } else {
                          loge("Failed to create network availability provider. slot index = "
                                  + slotIndex);
                      }
                      break;
  
                  case QNS_REMOVE_NETWORK_AVAILABILITY_PROVIDER:
                      if (provider != null) {
                          provider.close();
                          mProviders.remove(slotIndex);
                      }
                      break;
  
                  case QNS_REMOVE_ALL_NETWORK_AVAILABILITY_PROVIDERS:
                      for (int i = 0; i < mProviders.size(); i++) {
                          provider = mProviders.get(i);
                          if (provider != null) {
                              provider.close();
                          }
                      }
                      mProviders.clear();
                      break;
  
                  case QNS_UPDATE_QUALIFIED_NETWORKS:
                      if (provider == null) break;
                      provider.onUpdateQualifiedNetworkTypes(message.arg2, (int[]) message.obj);
                      break;
              }
          }
      }
  
      /**
       * Default constructor.
       */
      public QualifiedNetworksService() {
          mHandlerThread = new HandlerThread(TAG);
          mHandlerThread.start();
  
          mHandler = new QualifiedNetworksServiceHandler(mHandlerThread.getLooper());
          log("Qualified networks service created");
      }
  
      /**
       * Create the instance of {@link NetworkAvailabilityProvider}. Vendor qualified network service
       * must override this method to facilitate the creation of {@link NetworkAvailabilityProvider}
       * instances. The system will call this method after binding the qualified networks service for
       * each active SIM slot index.
       *
       * @param slotIndex SIM slot index the qualified networks service associated with.
       * @return Qualified networks service instance
       */
      @NonNull
      public abstract NetworkAvailabilityProvider onCreateNetworkAvailabilityProvider(int slotIndex);
  
      /** @hide */
      @Override
      public IBinder onBind(Intent intent) {
          if (intent == null || !QUALIFIED_NETWORKS_SERVICE_INTERFACE.equals(intent.getAction())) {
              loge("Unexpected intent " + intent);
              return null;
          }
          return mBinder;
      }
  
      /** @hide */
      @Override
      public boolean onUnbind(Intent intent) {
          mHandler.obtainMessage(QNS_REMOVE_ALL_NETWORK_AVAILABILITY_PROVIDERS).sendToTarget();
          return false;
      }
  
      /** @hide */
      @Override
      public void onDestroy() {
          mHandlerThread.quit();
      }
  
      /**
       * A wrapper around IQualifiedNetworksService that forwards calls to implementations of
       * {@link QualifiedNetworksService}.
       */
      private class IQualifiedNetworksServiceWrapper extends IQualifiedNetworksService.Stub {
          @Override
          public void createNetworkAvailabilityProvider(int slotIndex,
                                                        IQualifiedNetworksServiceCallback callback) {
              mHandler.obtainMessage(QNS_CREATE_NETWORK_AVAILABILITY_PROVIDER, slotIndex, 0,
                      callback).sendToTarget();
          }
  
          @Override
          public void removeNetworkAvailabilityProvider(int slotIndex) {
              mHandler.obtainMessage(QNS_REMOVE_NETWORK_AVAILABILITY_PROVIDER, slotIndex, 0)
                      .sendToTarget();
          }
      }
  
      private void log(String s) {
          Rlog.d(TAG, s);
      }
  
      private void loge(String s) {
          Rlog.e(TAG, s);
      }
  }
  