/*
* 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;
import android.Manifest.permission;
import android.content.BroadcastReceiver;
import android.content.ContentResolver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.pm.PackageManager;
import android.net.INetworkScoreCache;
import android.net.INetworkScoreService;
import android.net.NetworkScoreManager;
import android.net.NetworkScorerAppManager;
import android.net.NetworkScorerAppManager.NetworkScorerAppData;
import android.net.ScoredNetwork;
import android.os.Binder;
import android.os.PatternMatcher;
import android.os.RemoteException;
import android.os.UserHandle;
import android.provider.Settings;
import android.text.TextUtils;
import android.util.Log;
import com.android.internal.R;
import com.android.internal.annotations.GuardedBy;
import java.io.FileDescriptor;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
/**
* Backing service for {@link android.net.NetworkScoreManager}.
* @hide
*/
public class NetworkScoreService extends INetworkScoreService.Stub {
private static final String TAG = "NetworkScoreService";
private final Context mContext;
private final Map<Integer, INetworkScoreCache> mScoreCaches;
/** Lock used to update mReceiver when scorer package changes occur. */
private Object mReceiverLock = new Object[0];
/** Clears scores when the active scorer package is no longer valid. */
@GuardedBy("mReceiverLock")
private ScorerChangedReceiver mReceiver;
private class ScorerChangedReceiver extends BroadcastReceiver {
final String mRegisteredPackage;
ScorerChangedReceiver(String packageName) {
mRegisteredPackage = packageName;
}
@Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if ((Intent.ACTION_PACKAGE_CHANGED.equals(action) ||
Intent.ACTION_PACKAGE_REPLACED.equals(action) ||
Intent.ACTION_PACKAGE_FULLY_REMOVED.equals(action)) &&
NetworkScorerAppManager.getActiveScorer(mContext) == null) {
// Package change has invalidated a scorer.
Log.i(TAG, "Package " + mRegisteredPackage +
" is no longer valid, disabling scoring");
setScorerInternal(null);
}
}
}
public NetworkScoreService(Context context) {
mContext = context;
mScoreCaches = new HashMap<>();
}
/** Called when the system is ready to run third-party code but before it actually does so. */
void systemReady() {
ContentResolver cr = mContext.getContentResolver();
if (Settings.Global.getInt(cr, Settings.Global.NETWORK_SCORING_PROVISIONED, 0) == 0) {
// On first run, we try to initialize the scorer to the one configured at build time.
// This will be a no-op if the scorer isn't actually valid.
String defaultPackage = mContext.getResources().getString(
R.string.config_defaultNetworkScorerPackageName);
if (!TextUtils.isEmpty(defaultPackage)) {
NetworkScorerAppManager.setActiveScorer(mContext, defaultPackage);
}
Settings.Global.putInt(cr, Settings.Global.NETWORK_SCORING_PROVISIONED, 1);
}
registerPackageReceiverIfNeeded();
}
private void registerPackageReceiverIfNeeded() {
NetworkScorerAppData scorer = NetworkScorerAppManager.getActiveScorer(mContext);
synchronized (mReceiverLock) {
// Unregister the receiver if the current scorer has changed since last registration.
if (mReceiver != null) {
if (Log.isLoggable(TAG, Log.VERBOSE)) {
Log.v(TAG, "Unregistering receiver for " + mReceiver.mRegisteredPackage);
}
mContext.unregisterReceiver(mReceiver);
mReceiver = null;
}
// Register receiver if a scorer is active.
if (scorer != null) {
IntentFilter filter = new IntentFilter();
filter.addAction(Intent.ACTION_PACKAGE_CHANGED);
filter.addAction(Intent.ACTION_PACKAGE_REPLACED);
filter.addAction(Intent.ACTION_PACKAGE_FULLY_REMOVED);
filter.addDataScheme("package");
filter.addDataSchemeSpecificPart(scorer.mPackageName,
PatternMatcher.PATTERN_LITERAL);
mReceiver = new ScorerChangedReceiver(scorer.mPackageName);
// TODO: Need to update when we support per-user scorers.
mContext.registerReceiverAsUser(mReceiver, UserHandle.OWNER, filter, null, null);
if (Log.isLoggable(TAG, Log.VERBOSE)) {
Log.v(TAG, "Registered receiver for " + scorer.mPackageName);
}
}
}
}
@Override
public boolean updateScores(ScoredNetwork[] networks) {
if (!NetworkScorerAppManager.isCallerActiveScorer(mContext, getCallingUid())) {
throw new SecurityException("Caller with UID " + getCallingUid() +
" is not the active scorer.");
}
// Separate networks by type.
Map<Integer, List<ScoredNetwork>> networksByType = new HashMap<>();
for (ScoredNetwork network : networks) {
List<ScoredNetwork> networkList = networksByType.get(network.networkKey.type);
if (networkList == null) {
networkList = new ArrayList<>();
networksByType.put(network.networkKey.type, networkList);
}
networkList.add(network);
}
// Pass the scores of each type down to the appropriate network scorer.
for (Map.Entry<Integer, List<ScoredNetwork>> entry : networksByType.entrySet()) {
INetworkScoreCache scoreCache = mScoreCaches.get(entry.getKey());
if (scoreCache != null) {
try {
scoreCache.updateScores(entry.getValue());
} catch (RemoteException e) {
if (Log.isLoggable(TAG, Log.VERBOSE)) {
Log.v(TAG, "Unable to update scores of type " + entry.getKey(), e);
}
}
} else if (Log.isLoggable(TAG, Log.VERBOSE)) {
Log.v(TAG, "No scorer registered for type " + entry.getKey() + ", discarding");
}
}
return true;
}
@Override
public boolean clearScores() {
// Only the active scorer or the system (who can broadcast BROADCAST_NETWORK_PRIVILEGED)
// should be allowed to flush all scores.
if (NetworkScorerAppManager.isCallerActiveScorer(mContext, getCallingUid()) ||
mContext.checkCallingOrSelfPermission(permission.BROADCAST_NETWORK_PRIVILEGED) ==
PackageManager.PERMISSION_GRANTED) {
clearInternal();
return true;
} else {
throw new SecurityException(
"Caller is neither the active scorer nor the scorer manager.");
}
}
@Override
public boolean setActiveScorer(String packageName) {
// TODO: For now, since SCORE_NETWORKS requires an app to be privileged, we allow such apps
// to directly set the scorer app rather than having to use the consent dialog. The
// assumption is that anyone bundling a scorer app with the system is trusted by the OEM to
// do the right thing and not enable this feature without explaining it to the user.
// In the future, should this API be opened to 3p apps, we will need to lock this down and
// figure out another way to streamline the UX.
// mContext.enforceCallingOrSelfPermission(permission.BROADCAST_NETWORK_PRIVILEGED, TAG);
mContext.enforceCallingOrSelfPermission(permission.SCORE_NETWORKS, TAG);
return setScorerInternal(packageName);
}
@Override
public void disableScoring() {
// Only the active scorer or the system (who can broadcast BROADCAST_NETWORK_PRIVILEGED)
// should be allowed to disable scoring.
if (NetworkScorerAppManager.isCallerActiveScorer(mContext, getCallingUid()) ||
mContext.checkCallingOrSelfPermission(permission.BROADCAST_NETWORK_PRIVILEGED) ==
PackageManager.PERMISSION_GRANTED) {
// The return value is discarded here because at this point, the call should always
// succeed. The only reason for failure is if the new package is not a valid scorer, but
// we're disabling scoring altogether here.
setScorerInternal(null /* packageName */);
} else {
throw new SecurityException(
"Caller is neither the active scorer nor the scorer manager.");
}
}
/** Set the active scorer. Callers are responsible for checking permissions as appropriate. */
private boolean setScorerInternal(String packageName) {
long token = Binder.clearCallingIdentity();
try {
// Preemptively clear scores even though the set operation could fail. We do this for
// safety as scores should never be compared across apps; in practice, Settings should
// only be allowing valid apps to be set as scorers, so failure here should be rare.
clearInternal();
boolean result = NetworkScorerAppManager.setActiveScorer(mContext, packageName);
if (result) {
registerPackageReceiverIfNeeded();
Intent intent = new Intent(NetworkScoreManager.ACTION_SCORER_CHANGED);
intent.putExtra(NetworkScoreManager.EXTRA_NEW_SCORER, packageName);
mContext.sendBroadcastAsUser(intent, UserHandle.ALL);
}
return result;
} finally {
Binder.restoreCallingIdentity(token);
}
}
/** Clear scores. Callers are responsible for checking permissions as appropriate. */
private void clearInternal() {
Set<INetworkScoreCache> cachesToClear = getScoreCaches();
for (INetworkScoreCache scoreCache : cachesToClear) {
try {
scoreCache.clearScores();
} catch (RemoteException e) {
if (Log.isLoggable(TAG, Log.VERBOSE)) {
Log.v(TAG, "Unable to clear scores", e);
}
}
}
}
@Override
public void registerNetworkScoreCache(int networkType, INetworkScoreCache scoreCache) {
mContext.enforceCallingOrSelfPermission(permission.BROADCAST_NETWORK_PRIVILEGED, TAG);
synchronized (mScoreCaches) {
if (mScoreCaches.containsKey(networkType)) {
throw new IllegalArgumentException(
"Score cache already registered for type " + networkType);
}
mScoreCaches.put(networkType, scoreCache);
}
}
@Override
protected void dump(FileDescriptor fd, PrintWriter writer, String[] args) {
mContext.enforceCallingOrSelfPermission(permission.DUMP, TAG);
NetworkScorerAppData currentScorer = NetworkScorerAppManager.getActiveScorer(mContext);
if (currentScorer == null) {
writer.println("Scoring is disabled.");
return;
}
writer.println("Current scorer: " + currentScorer.mPackageName);
writer.flush();
for (INetworkScoreCache scoreCache : getScoreCaches()) {
try {
scoreCache.asBinder().dump(fd, args);
} catch (RemoteException e) {
writer.println("Unable to dump score cache");
if (Log.isLoggable(TAG, Log.VERBOSE)) {
Log.v(TAG, "Unable to dump score cache", e);
}
}
}
}
/**
* Returns a set of all score caches that are currently active.
*
* <p>May be used to perform an action on all score caches without potentially strange behavior
* if a new scorer is registered during that action's execution.
*/
private Set<INetworkScoreCache> getScoreCaches() {
synchronized (mScoreCaches) {
return new HashSet<>(mScoreCaches.values());
}
}
}
|
