| /* |
| * Copyright (C) 2017 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.lowpan; |
| |
| import android.annotation.NonNull; |
| import android.annotation.Nullable; |
| import android.content.Context; |
| import android.os.DeadObjectException; |
| import android.os.Handler; |
| import android.os.IBinder; |
| import android.os.RemoteException; |
| import android.os.ServiceManager; |
| import android.util.AndroidException; |
| import android.util.Log; |
| import java.util.HashMap; |
| |
| /** |
| * Manager object for looking up LoWPAN interfaces. |
| * |
| * @hide |
| */ |
| //@SystemApi |
| public class LowpanManager { |
| private static final String TAG = LowpanManager.class.getSimpleName(); |
| |
| ////////////////////////////////////////////////////////////////////////// |
| // Public Classes |
| |
| /** @hide */ |
| //@SystemApi |
| public abstract static class Callback { |
| public void onInterfaceAdded(LowpanInterface lowpan_interface) {} |
| |
| public void onInterfaceRemoved(LowpanInterface lowpan_interface) {} |
| } |
| |
| ////////////////////////////////////////////////////////////////////////// |
| // Instance Variables |
| |
| private ILowpanManager mManager; |
| private HashMap<Integer, ILowpanManagerListener> mListenerMap = new HashMap<>(); |
| |
| ////////////////////////////////////////////////////////////////////////// |
| |
| private static LowpanManager sSingletonInstance; |
| |
| ////////////////////////////////////////////////////////////////////////// |
| // Static Methods |
| |
| /** Returns a reference to the LowpanManager object, allocating it if necessary. */ |
| public static LowpanManager getManager() { |
| return from(null); |
| } |
| |
| public static LowpanManager from(Context context) { |
| // TODO: Actually get this from the context! |
| |
| if (sSingletonInstance == null) { |
| sSingletonInstance = new LowpanManager(); |
| } |
| return sSingletonInstance; |
| } |
| |
| ////////////////////////////////////////////////////////////////////////// |
| // Constructors |
| |
| /** |
| * Private LowpanManager constructor. Since we are a singleton, we do not allow external |
| * construction. |
| */ |
| private LowpanManager() {} |
| |
| ////////////////////////////////////////////////////////////////////////// |
| // Private Methods |
| |
| /** |
| * Returns a reference to the ILowpanManager interface, provided by the LoWPAN Manager Service. |
| */ |
| @Nullable |
| private ILowpanManager getILowpanManager() { |
| ILowpanManager manager = mManager; |
| if (manager == null) { |
| IBinder serviceBinder = |
| new ServiceManager().getService(ILowpanManager.LOWPAN_SERVICE_NAME); |
| mManager = manager = ILowpanManager.Stub.asInterface(serviceBinder); |
| |
| // Add any listeners |
| synchronized (mListenerMap) { |
| for (Integer hashObj : mListenerMap.keySet()) { |
| try { |
| manager.addListener(mListenerMap.get(hashObj)); |
| } catch (RemoteException x) { |
| // Consider any failure here as implying the manager is defunct |
| mManager = manager = null; |
| } |
| } |
| } |
| } |
| return manager; |
| } |
| |
| ////////////////////////////////////////////////////////////////////////// |
| // Public Methods |
| |
| /** |
| * Returns a reference to the requested LowpanInterface object. If the given interface doesn't |
| * exist, or it is not a LoWPAN interface, returns null. |
| */ |
| @Nullable |
| public LowpanInterface getInterface(@NonNull String name) { |
| LowpanInterface ret = null; |
| ILowpanManager manager = getILowpanManager(); |
| |
| // Maximum number of tries is two. We should only try |
| // more than once if our manager has died or there |
| // was some sort of AIDL buffer full event. |
| for (int i = 0; i < 2 && manager != null; i++) { |
| try { |
| ILowpanInterface iface = manager.getInterface(name); |
| if (iface != null) { |
| ret = LowpanInterface.getInterfaceFromBinder(iface.asBinder()); |
| } |
| break; |
| } catch (RemoteException x) { |
| // In all of the cases when we get this exception, we reconnect and try again |
| mManager = null; |
| manager = getILowpanManager(); |
| } |
| } |
| return ret; |
| } |
| |
| /** |
| * Returns a reference to the first registered LowpanInterface object. If there are no LoWPAN |
| * interfaces registered, returns null. |
| */ |
| @Nullable |
| public LowpanInterface getInterface() { |
| String[] ifaceList = getInterfaceList(); |
| if (ifaceList != null && ifaceList.length > 0) { |
| return getInterface(ifaceList[0]); |
| } |
| return null; |
| } |
| |
| /** |
| * Returns a string array containing the names of LoWPAN interfaces. This list may contain fewer |
| * interfaces if the calling process does not have permissions to see individual interfaces. |
| */ |
| @NonNull |
| public String[] getInterfaceList() { |
| ILowpanManager manager = getILowpanManager(); |
| |
| if (manager != null) { |
| try { |
| return manager.getInterfaceList(); |
| |
| } catch (RemoteException x) { |
| // In all of the cases when we get this exception, we reconnect and try again |
| mManager = null; |
| try { |
| manager = getILowpanManager(); |
| if (manager != null) { |
| return manager.getInterfaceList(); |
| } |
| } catch (RemoteException ex) { |
| // Something weird is going on, so we log it |
| // and fall back thru to returning an empty array. |
| Log.e(TAG, ex.toString()); |
| mManager = null; |
| } |
| } |
| } |
| |
| // Return empty list if we have no service. |
| return new String[0]; |
| } |
| |
| /** |
| * Registers a callback object to receive notifications when LoWPAN interfaces are added or |
| * removed. |
| * |
| * @hide |
| */ |
| public void registerCallback(@NonNull Callback cb, @Nullable Handler handler) |
| throws LowpanException { |
| ILowpanManagerListener.Stub listenerBinder = |
| new ILowpanManagerListener.Stub() { |
| public void onInterfaceAdded(ILowpanInterface lowpan_interface) { |
| Runnable runnable = |
| new Runnable() { |
| @Override |
| public void run() { |
| cb.onInterfaceAdded( |
| LowpanInterface.getInterfaceFromBinder( |
| lowpan_interface.asBinder())); |
| } |
| }; |
| |
| if (handler != null) { |
| handler.post(runnable); |
| } else { |
| runnable.run(); |
| } |
| } |
| |
| public void onInterfaceRemoved(ILowpanInterface lowpan_interface) { |
| Runnable runnable = |
| new Runnable() { |
| @Override |
| public void run() { |
| cb.onInterfaceRemoved( |
| LowpanInterface.getInterfaceFromBinder( |
| lowpan_interface.asBinder())); |
| } |
| }; |
| |
| if (handler != null) { |
| handler.post(runnable); |
| } else { |
| runnable.run(); |
| } |
| } |
| }; |
| ILowpanManager manager = getILowpanManager(); |
| if (manager != null) { |
| try { |
| manager.addListener(listenerBinder); |
| } catch (DeadObjectException x) { |
| mManager = null; |
| // Tickle the ILowpanManager instance, which might |
| // get us added back. |
| getILowpanManager(); |
| } catch (Throwable x) { |
| LowpanException.throwAsPublicException(x); |
| } |
| } |
| synchronized (mListenerMap) { |
| mListenerMap.put(Integer.valueOf(System.identityHashCode(cb)), listenerBinder); |
| } |
| } |
| |
| /** @hide */ |
| public void registerCallback(@NonNull Callback cb) throws LowpanException { |
| registerCallback(cb, null); |
| } |
| |
| /** |
| * Unregisters a previously registered {@link LowpanManager.Callback} object. |
| * |
| * @hide |
| */ |
| public void unregisterCallback(@NonNull Callback cb) throws AndroidException { |
| Integer hashCode = Integer.valueOf(System.identityHashCode(cb)); |
| ILowpanManagerListener listenerBinder = mListenerMap.get(hashCode); |
| if (listenerBinder != null) { |
| synchronized (mListenerMap) { |
| mListenerMap.remove(hashCode); |
| } |
| if (getILowpanManager() != null) { |
| try { |
| mManager.removeListener(listenerBinder); |
| } catch (DeadObjectException x) { |
| mManager = null; |
| } |
| } |
| } |
| } |
| } |