/*
|
* Copyright (C) 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 com.android.server;
|
|
import static android.content.pm.PackageManager.PERMISSION_GRANTED;
|
|
import android.content.Context;
|
import android.hardware.ISensorPrivacyListener;
|
import android.hardware.ISensorPrivacyManager;
|
import android.os.Environment;
|
import android.os.Handler;
|
import android.os.IBinder;
|
import android.os.Looper;
|
import android.os.RemoteCallbackList;
|
import android.os.RemoteException;
|
import android.util.ArrayMap;
|
import android.util.AtomicFile;
|
import android.util.Log;
|
import android.util.Xml;
|
|
import com.android.internal.annotations.GuardedBy;
|
import com.android.internal.util.FastXmlSerializer;
|
import com.android.internal.util.XmlUtils;
|
import com.android.internal.util.function.pooled.PooledLambda;
|
|
import org.xmlpull.v1.XmlPullParser;
|
import org.xmlpull.v1.XmlPullParserException;
|
import org.xmlpull.v1.XmlSerializer;
|
|
import java.io.File;
|
import java.io.FileInputStream;
|
import java.io.FileOutputStream;
|
import java.io.IOException;
|
import java.nio.charset.StandardCharsets;
|
import java.util.NoSuchElementException;
|
|
/** @hide */
|
public final class SensorPrivacyService extends SystemService {
|
|
private static final String TAG = "SensorPrivacyService";
|
|
private static final String SENSOR_PRIVACY_XML_FILE = "sensor_privacy.xml";
|
private static final String XML_TAG_SENSOR_PRIVACY = "sensor-privacy";
|
private static final String XML_ATTRIBUTE_ENABLED = "enabled";
|
|
private final SensorPrivacyServiceImpl mSensorPrivacyServiceImpl;
|
|
public SensorPrivacyService(Context context) {
|
super(context);
|
mSensorPrivacyServiceImpl = new SensorPrivacyServiceImpl(context);
|
}
|
|
@Override
|
public void onStart() {
|
publishBinderService(Context.SENSOR_PRIVACY_SERVICE, mSensorPrivacyServiceImpl);
|
}
|
|
class SensorPrivacyServiceImpl extends ISensorPrivacyManager.Stub {
|
|
private final SensorPrivacyHandler mHandler;
|
private final Context mContext;
|
private final Object mLock = new Object();
|
@GuardedBy("mLock")
|
private final AtomicFile mAtomicFile;
|
@GuardedBy("mLock")
|
private boolean mEnabled;
|
|
SensorPrivacyServiceImpl(Context context) {
|
mContext = context;
|
mHandler = new SensorPrivacyHandler(FgThread.get().getLooper(), mContext);
|
File sensorPrivacyFile = new File(Environment.getDataSystemDirectory(),
|
SENSOR_PRIVACY_XML_FILE);
|
mAtomicFile = new AtomicFile(sensorPrivacyFile);
|
synchronized (mLock) {
|
mEnabled = readPersistedSensorPrivacyEnabledLocked();
|
}
|
}
|
|
/**
|
* Sets the sensor privacy to the provided state and notifies all listeners of the new
|
* state.
|
*/
|
@Override
|
public void setSensorPrivacy(boolean enable) {
|
enforceSensorPrivacyPermission();
|
synchronized (mLock) {
|
mEnabled = enable;
|
FileOutputStream outputStream = null;
|
try {
|
XmlSerializer serializer = new FastXmlSerializer();
|
outputStream = mAtomicFile.startWrite();
|
serializer.setOutput(outputStream, StandardCharsets.UTF_8.name());
|
serializer.startDocument(null, true);
|
serializer.startTag(null, XML_TAG_SENSOR_PRIVACY);
|
serializer.attribute(null, XML_ATTRIBUTE_ENABLED, String.valueOf(enable));
|
serializer.endTag(null, XML_TAG_SENSOR_PRIVACY);
|
serializer.endDocument();
|
mAtomicFile.finishWrite(outputStream);
|
} catch (IOException e) {
|
Log.e(TAG, "Caught an exception persisting the sensor privacy state: ", e);
|
mAtomicFile.failWrite(outputStream);
|
}
|
}
|
mHandler.onSensorPrivacyChanged(enable);
|
}
|
|
/**
|
* Enforces the caller contains the necessary permission to change the state of sensor
|
* privacy.
|
*/
|
private void enforceSensorPrivacyPermission() {
|
if (mContext.checkCallingOrSelfPermission(
|
android.Manifest.permission.MANAGE_SENSOR_PRIVACY) == PERMISSION_GRANTED) {
|
return;
|
}
|
throw new SecurityException(
|
"Changing sensor privacy requires the following permission: "
|
+ android.Manifest.permission.MANAGE_SENSOR_PRIVACY);
|
}
|
|
/**
|
* Returns whether sensor privacy is enabled.
|
*/
|
@Override
|
public boolean isSensorPrivacyEnabled() {
|
synchronized (mLock) {
|
return mEnabled;
|
}
|
}
|
|
/**
|
* Returns the state of sensor privacy from persistent storage.
|
*/
|
private boolean readPersistedSensorPrivacyEnabledLocked() {
|
// if the file does not exist then sensor privacy has not yet been enabled on
|
// the device.
|
if (!mAtomicFile.exists()) {
|
return false;
|
}
|
boolean enabled;
|
try (FileInputStream inputStream = mAtomicFile.openRead()) {
|
XmlPullParser parser = Xml.newPullParser();
|
parser.setInput(inputStream, StandardCharsets.UTF_8.name());
|
XmlUtils.beginDocument(parser, XML_TAG_SENSOR_PRIVACY);
|
parser.next();
|
String tagName = parser.getName();
|
enabled = Boolean.valueOf(parser.getAttributeValue(null, XML_ATTRIBUTE_ENABLED));
|
} catch (IOException | XmlPullParserException e) {
|
Log.e(TAG, "Caught an exception reading the state from storage: ", e);
|
// Delete the file to prevent the same error on subsequent calls and assume sensor
|
// privacy is not enabled.
|
mAtomicFile.delete();
|
enabled = false;
|
}
|
return enabled;
|
}
|
|
/**
|
* Persists the state of sensor privacy.
|
*/
|
private void persistSensorPrivacyState() {
|
synchronized (mLock) {
|
FileOutputStream outputStream = null;
|
try {
|
XmlSerializer serializer = new FastXmlSerializer();
|
outputStream = mAtomicFile.startWrite();
|
serializer.setOutput(outputStream, StandardCharsets.UTF_8.name());
|
serializer.startDocument(null, true);
|
serializer.startTag(null, XML_TAG_SENSOR_PRIVACY);
|
serializer.attribute(null, XML_ATTRIBUTE_ENABLED, String.valueOf(mEnabled));
|
serializer.endTag(null, XML_TAG_SENSOR_PRIVACY);
|
serializer.endDocument();
|
mAtomicFile.finishWrite(outputStream);
|
} catch (IOException e) {
|
Log.e(TAG, "Caught an exception persisting the sensor privacy state: ", e);
|
mAtomicFile.failWrite(outputStream);
|
}
|
}
|
}
|
|
/**
|
* Registers a listener to be notified when the sensor privacy state changes.
|
*/
|
@Override
|
public void addSensorPrivacyListener(ISensorPrivacyListener listener) {
|
if (listener == null) {
|
throw new NullPointerException("listener cannot be null");
|
}
|
mHandler.addListener(listener);
|
}
|
|
/**
|
* Unregisters a listener from sensor privacy state change notifications.
|
*/
|
@Override
|
public void removeSensorPrivacyListener(ISensorPrivacyListener listener) {
|
if (listener == null) {
|
throw new NullPointerException("listener cannot be null");
|
}
|
mHandler.removeListener(listener);
|
}
|
}
|
|
/**
|
* Handles sensor privacy state changes and notifying listeners of the change.
|
*/
|
private final class SensorPrivacyHandler extends Handler {
|
private static final int MESSAGE_SENSOR_PRIVACY_CHANGED = 1;
|
|
private final Object mListenerLock = new Object();
|
|
@GuardedBy("mListenerLock")
|
private final RemoteCallbackList<ISensorPrivacyListener> mListeners =
|
new RemoteCallbackList<>();
|
private final ArrayMap<ISensorPrivacyListener, DeathRecipient> mDeathRecipients;
|
private final Context mContext;
|
|
SensorPrivacyHandler(Looper looper, Context context) {
|
super(looper);
|
mDeathRecipients = new ArrayMap<>();
|
mContext = context;
|
}
|
|
public void onSensorPrivacyChanged(boolean enabled) {
|
sendMessage(PooledLambda.obtainMessage(SensorPrivacyHandler::handleSensorPrivacyChanged,
|
this, enabled));
|
sendMessage(
|
PooledLambda.obtainMessage(SensorPrivacyServiceImpl::persistSensorPrivacyState,
|
mSensorPrivacyServiceImpl));
|
}
|
|
public void addListener(ISensorPrivacyListener listener) {
|
synchronized (mListenerLock) {
|
DeathRecipient deathRecipient = new DeathRecipient(listener);
|
mDeathRecipients.put(listener, deathRecipient);
|
mListeners.register(listener);
|
}
|
}
|
|
public void removeListener(ISensorPrivacyListener listener) {
|
synchronized (mListenerLock) {
|
DeathRecipient deathRecipient = mDeathRecipients.remove(listener);
|
if (deathRecipient != null) {
|
deathRecipient.destroy();
|
}
|
mListeners.unregister(listener);
|
}
|
}
|
|
public void handleSensorPrivacyChanged(boolean enabled) {
|
final int count = mListeners.beginBroadcast();
|
for (int i = 0; i < count; i++) {
|
ISensorPrivacyListener listener = mListeners.getBroadcastItem(i);
|
try {
|
listener.onSensorPrivacyChanged(enabled);
|
} catch (RemoteException e) {
|
Log.e(TAG, "Caught an exception notifying listener " + listener + ": ", e);
|
}
|
}
|
mListeners.finishBroadcast();
|
}
|
}
|
|
private final class DeathRecipient implements IBinder.DeathRecipient {
|
|
private ISensorPrivacyListener mListener;
|
|
DeathRecipient(ISensorPrivacyListener listener) {
|
mListener = listener;
|
try {
|
mListener.asBinder().linkToDeath(this, 0);
|
} catch (RemoteException e) {
|
}
|
}
|
|
@Override
|
public void binderDied() {
|
mSensorPrivacyServiceImpl.removeSensorPrivacyListener(mListener);
|
}
|
|
public void destroy() {
|
try {
|
mListener.asBinder().unlinkToDeath(this, 0);
|
} catch (NoSuchElementException e) {
|
}
|
}
|
}
|
}
|
