| /* |
| * Copyright (C) 2014 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.location; |
| |
| import android.annotation.NonNull; |
| import android.app.AppOpsManager; |
| import android.content.Context; |
| import android.os.Handler; |
| import android.os.IBinder; |
| import android.os.IInterface; |
| import android.os.RemoteException; |
| import android.util.Log; |
| |
| import com.android.internal.util.Preconditions; |
| |
| import java.util.HashMap; |
| import java.util.Map; |
| |
| /** |
| * A helper class that handles operations in remote listeners. |
| * |
| * @param <TListener> the type of GNSS data listener. |
| */ |
| public abstract class RemoteListenerHelper<TListener extends IInterface> { |
| |
| protected static final int RESULT_SUCCESS = 0; |
| protected static final int RESULT_NOT_AVAILABLE = 1; |
| protected static final int RESULT_NOT_SUPPORTED = 2; |
| protected static final int RESULT_GPS_LOCATION_DISABLED = 3; |
| protected static final int RESULT_INTERNAL_ERROR = 4; |
| protected static final int RESULT_UNKNOWN = 5; |
| protected static final int RESULT_NOT_ALLOWED = 6; |
| |
| protected final Handler mHandler; |
| private final String mTag; |
| |
| private final Map<IBinder, IdentifiedListener> mListenerMap = new HashMap<>(); |
| |
| protected final Context mContext; |
| protected final AppOpsManager mAppOps; |
| |
| private volatile boolean mIsRegistered; // must access only on handler thread, or read-only |
| |
| private boolean mHasIsSupported; |
| private boolean mIsSupported; |
| |
| private int mLastReportedResult = RESULT_UNKNOWN; |
| |
| protected RemoteListenerHelper(Context context, Handler handler, String name) { |
| Preconditions.checkNotNull(name); |
| mHandler = handler; |
| mTag = name; |
| mContext = context; |
| mAppOps = (AppOpsManager) context.getSystemService(Context.APP_OPS_SERVICE); |
| } |
| |
| // read-only access for a dump() thread assured via volatile |
| public boolean isRegistered() { |
| return mIsRegistered; |
| } |
| |
| /** |
| * Adds GNSS data listener {@code listener} with caller identify {@code callerIdentify}. |
| */ |
| public void addListener(@NonNull TListener listener, CallerIdentity callerIdentity) { |
| Preconditions.checkNotNull(listener, "Attempted to register a 'null' listener."); |
| IBinder binder = listener.asBinder(); |
| synchronized (mListenerMap) { |
| if (mListenerMap.containsKey(binder)) { |
| // listener already added |
| return; |
| } |
| |
| IdentifiedListener identifiedListener = new IdentifiedListener(listener, |
| callerIdentity); |
| mListenerMap.put(binder, identifiedListener); |
| |
| // update statuses we already know about, starting from the ones that will never change |
| int result; |
| if (!isAvailableInPlatform()) { |
| result = RESULT_NOT_AVAILABLE; |
| } else if (mHasIsSupported && !mIsSupported) { |
| result = RESULT_NOT_SUPPORTED; |
| } else if (!isGpsEnabled()) { |
| // only attempt to register if GPS is enabled, otherwise we will register once GPS |
| // becomes available |
| result = RESULT_GPS_LOCATION_DISABLED; |
| } else if (mHasIsSupported && mIsSupported) { |
| tryRegister(); |
| // initially presume success, possible internal error could follow asynchornously |
| result = RESULT_SUCCESS; |
| } else { |
| // at this point if the supported flag is not set, the notification will be sent |
| // asynchronously in the future |
| return; |
| } |
| post(identifiedListener, getHandlerOperation(result)); |
| } |
| } |
| |
| /** |
| * Remove GNSS data listener {@code listener}. |
| */ |
| public void removeListener(@NonNull TListener listener) { |
| Preconditions.checkNotNull(listener, "Attempted to remove a 'null' listener."); |
| synchronized (mListenerMap) { |
| mListenerMap.remove(listener.asBinder()); |
| if (mListenerMap.isEmpty()) { |
| tryUnregister(); |
| } |
| } |
| } |
| |
| protected abstract boolean isAvailableInPlatform(); |
| protected abstract boolean isGpsEnabled(); |
| // must access only on handler thread |
| protected abstract int registerWithService(); |
| protected abstract void unregisterFromService(); // must access only on handler thread |
| protected abstract ListenerOperation<TListener> getHandlerOperation(int result); |
| |
| protected interface ListenerOperation<TListener extends IInterface> { |
| void execute(TListener listener, CallerIdentity callerIdentity) throws RemoteException; |
| } |
| |
| protected void foreach(ListenerOperation<TListener> operation) { |
| synchronized (mListenerMap) { |
| foreachUnsafe(operation); |
| } |
| } |
| |
| protected void setSupported(boolean value) { |
| synchronized (mListenerMap) { |
| mHasIsSupported = true; |
| mIsSupported = value; |
| } |
| } |
| |
| protected void tryUpdateRegistrationWithService() { |
| synchronized (mListenerMap) { |
| if (!isGpsEnabled()) { |
| tryUnregister(); |
| return; |
| } |
| if (mListenerMap.isEmpty()) { |
| return; |
| } |
| tryRegister(); |
| } |
| } |
| |
| protected void updateResult() { |
| synchronized (mListenerMap) { |
| int newResult = calculateCurrentResultUnsafe(); |
| if (mLastReportedResult == newResult) { |
| return; |
| } |
| foreachUnsafe(getHandlerOperation(newResult)); |
| mLastReportedResult = newResult; |
| } |
| } |
| |
| protected boolean hasPermission(Context context, CallerIdentity callerIdentity) { |
| if (LocationPermissionUtil.doesCallerReportToAppOps(context, callerIdentity)) { |
| // The caller is identified as a location provider that will report location |
| // access to AppOps. Skip noteOp but do checkOp to check for location permission. |
| return mAppOps.checkOpNoThrow(AppOpsManager.OP_FINE_LOCATION, callerIdentity.mUid, |
| callerIdentity.mPackageName) == AppOpsManager.MODE_ALLOWED; |
| } |
| |
| return mAppOps.noteOpNoThrow(AppOpsManager.OP_FINE_LOCATION, callerIdentity.mUid, |
| callerIdentity.mPackageName, null, |
| "Location sent to " + callerIdentity.mListenerIdentifier) |
| == AppOpsManager.MODE_ALLOWED; |
| } |
| |
| protected void logPermissionDisabledEventNotReported(String tag, String packageName, |
| String event) { |
| if (Log.isLoggable(tag, Log.DEBUG)) { |
| Log.d(tag, "Location permission disabled. Skipping " + event + " reporting for app: " |
| + packageName); |
| } |
| } |
| |
| private void foreachUnsafe(ListenerOperation<TListener> operation) { |
| for (IdentifiedListener identifiedListener : mListenerMap.values()) { |
| post(identifiedListener, operation); |
| } |
| } |
| |
| private void post(IdentifiedListener identifiedListener, |
| ListenerOperation<TListener> operation) { |
| if (operation != null) { |
| mHandler.post(new HandlerRunnable(identifiedListener, operation)); |
| } |
| } |
| |
| private void tryRegister() { |
| mHandler.post(new Runnable() { |
| int registrationState = RESULT_INTERNAL_ERROR; |
| @Override |
| public void run() { |
| if (!mIsRegistered) { |
| registrationState = registerWithService(); |
| mIsRegistered = registrationState == RESULT_SUCCESS; |
| } |
| if (!mIsRegistered) { |
| // post back a failure |
| mHandler.post(() -> { |
| synchronized (mListenerMap) { |
| foreachUnsafe(getHandlerOperation(registrationState)); |
| } |
| }); |
| } |
| } |
| }); |
| } |
| |
| private void tryUnregister() { |
| mHandler.post(() -> { |
| if (!mIsRegistered) { |
| return; |
| } |
| unregisterFromService(); |
| mIsRegistered = false; |
| } |
| ); |
| } |
| |
| private int calculateCurrentResultUnsafe() { |
| // update statuses we already know about, starting from the ones that will never change |
| if (!isAvailableInPlatform()) { |
| return RESULT_NOT_AVAILABLE; |
| } |
| if (!mHasIsSupported || mListenerMap.isEmpty()) { |
| // we'll update once we have a supported status available |
| return RESULT_UNKNOWN; |
| } |
| if (!mIsSupported) { |
| return RESULT_NOT_SUPPORTED; |
| } |
| if (!isGpsEnabled()) { |
| return RESULT_GPS_LOCATION_DISABLED; |
| } |
| return RESULT_SUCCESS; |
| } |
| |
| private class IdentifiedListener { |
| private final TListener mListener; |
| private final CallerIdentity mCallerIdentity; |
| |
| private IdentifiedListener(@NonNull TListener listener, CallerIdentity callerIdentity) { |
| mListener = listener; |
| mCallerIdentity = callerIdentity; |
| } |
| } |
| |
| private class HandlerRunnable implements Runnable { |
| private final IdentifiedListener mIdentifiedListener; |
| private final ListenerOperation<TListener> mOperation; |
| |
| private HandlerRunnable(IdentifiedListener identifiedListener, |
| ListenerOperation<TListener> operation) { |
| mIdentifiedListener = identifiedListener; |
| mOperation = operation; |
| } |
| |
| @Override |
| public void run() { |
| try { |
| mOperation.execute(mIdentifiedListener.mListener, |
| mIdentifiedListener.mCallerIdentity); |
| } catch (RemoteException e) { |
| Log.v(mTag, "Error in monitored listener.", e); |
| } |
| } |
| } |
| } |