/*
* 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 android.net;
import android.Manifest;
import android.Manifest.permission;
import android.annotation.Nullable;
import android.app.AppOpsManager;
import android.content.Context;
import android.content.Intent;
import android.content.pm.ActivityInfo;
import android.content.pm.PackageManager;
import android.content.pm.ResolveInfo;
import android.os.UserHandle;
import android.provider.Settings;
import android.text.TextUtils;
import android.util.Log;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
/**
* Internal class for managing the primary network scorer application.
*
* TODO: Rename this to something more generic.
*
* @hide
*/
public final class NetworkScorerAppManager {
private static final String TAG = "NetworkScorerAppManager";
private static final Intent SCORE_INTENT =
new Intent(NetworkScoreManager.ACTION_SCORE_NETWORKS);
/** This class cannot be instantiated. */
private NetworkScorerAppManager() {}
public static class NetworkScorerAppData {
/** Package name of this scorer app. */
public final String mPackageName;
/** Name of this scorer app for display. */
public final CharSequence mScorerName;
/**
* Optional class name of a configuration activity. Null if none is set.
*
* @see NetworkScoreManager#ACTION_CUSTOM_ENABLE
*/
public final String mConfigurationActivityClassName;
public NetworkScorerAppData(String packageName, CharSequence scorerName,
@Nullable String configurationActivityClassName) {
mScorerName = scorerName;
mPackageName = packageName;
mConfigurationActivityClassName = configurationActivityClassName;
}
}
/**
* Returns the list of available scorer apps.
*
* <p>A network scorer is any application which:
* <ul>
* <li>Declares the {@link android.Manifest.permission#SCORE_NETWORKS} permission.
* <li>Includes a receiver for {@link NetworkScoreManager#ACTION_SCORE_NETWORKS} guarded by the
* {@link android.Manifest.permission#BROADCAST_NETWORK_PRIVILEGED} permission.
* </ul>
*
* @return the list of scorers, or the empty list if there are no valid scorers.
*/
public static Collection<NetworkScorerAppData> getAllValidScorers(Context context) {
List<NetworkScorerAppData> scorers = new ArrayList<>();
PackageManager pm = context.getPackageManager();
// Only apps installed under the primary user of the device can be scorers.
List<ResolveInfo> receivers =
pm.queryBroadcastReceivers(SCORE_INTENT, 0 /* flags */, UserHandle.USER_OWNER);
for (ResolveInfo receiver : receivers) {
// This field is a misnomer, see android.content.pm.ResolveInfo#activityInfo
final ActivityInfo receiverInfo = receiver.activityInfo;
if (receiverInfo == null) {
// Should never happen with queryBroadcastReceivers, but invalid nonetheless.
continue;
}
if (!permission.BROADCAST_NETWORK_PRIVILEGED.equals(receiverInfo.permission)) {
// Receiver doesn't require the BROADCAST_NETWORK_PRIVILEGED permission, which means
// anyone could trigger network scoring and flood the framework with score requests.
continue;
}
if (pm.checkPermission(permission.SCORE_NETWORKS, receiverInfo.packageName) !=
PackageManager.PERMISSION_GRANTED) {
// Application doesn't hold the SCORE_NETWORKS permission, so the user never
// approved it as a network scorer.
continue;
}
// Optionally, this package may specify a configuration activity.
String configurationActivityClassName = null;
Intent intent = new Intent(NetworkScoreManager.ACTION_CUSTOM_ENABLE);
intent.setPackage(receiverInfo.packageName);
List<ResolveInfo> configActivities = pm.queryIntentActivities(intent, 0 /* flags */);
if (!configActivities.isEmpty()) {
ActivityInfo activityInfo = configActivities.get(0).activityInfo;
if (activityInfo != null) {
configurationActivityClassName = activityInfo.name;
}
}
// NOTE: loadLabel will attempt to load the receiver's label and fall back to the app
// label if none is present.
scorers.add(new NetworkScorerAppData(receiverInfo.packageName,
receiverInfo.loadLabel(pm), configurationActivityClassName));
}
return scorers;
}
/**
* Get the application to use for scoring networks.
*
* @return the scorer app info or null if scoring is disabled (including if no scorer was ever
* selected) or if the previously-set scorer is no longer a valid scorer app (e.g. because
* it was disabled or uninstalled).
*/
public static NetworkScorerAppData getActiveScorer(Context context) {
String scorerPackage = Settings.Global.getString(context.getContentResolver(),
Settings.Global.NETWORK_SCORER_APP);
return getScorer(context, scorerPackage);
}
/**
* Set the specified package as the default scorer application.
*
* <p>The caller must have permission to write to {@link android.provider.Settings.Global}.
*
* @param context the context of the calling application
* @param packageName the packageName of the new scorer to use. If null, scoring will be
* disabled. Otherwise, the scorer will only be set if it is a valid scorer application.
* @return true if the scorer was changed, or false if the package is not a valid scorer.
*/
public static boolean setActiveScorer(Context context, String packageName) {
String oldPackageName = Settings.Global.getString(context.getContentResolver(),
Settings.Global.NETWORK_SCORER_APP);
if (TextUtils.equals(oldPackageName, packageName)) {
// No change.
return true;
}
Log.i(TAG, "Changing network scorer from " + oldPackageName + " to " + packageName);
if (packageName == null) {
Settings.Global.putString(context.getContentResolver(),
Settings.Global.NETWORK_SCORER_APP, null);
return true;
} else {
// We only make the change if the new package is valid.
if (getScorer(context, packageName) != null) {
Settings.Global.putString(context.getContentResolver(),
Settings.Global.NETWORK_SCORER_APP, packageName);
return true;
} else {
Log.w(TAG, "Requested network scorer is not valid: " + packageName);
return false;
}
}
}
/** Determine whether the application with the given UID is the enabled scorer. */
public static boolean isCallerActiveScorer(Context context, int callingUid) {
NetworkScorerAppData defaultApp = getActiveScorer(context);
if (defaultApp == null) {
return false;
}
AppOpsManager appOpsMgr = (AppOpsManager) context.getSystemService(Context.APP_OPS_SERVICE);
try {
appOpsMgr.checkPackage(callingUid, defaultApp.mPackageName);
} catch (SecurityException e) {
return false;
}
// To be extra safe, ensure the caller holds the SCORE_NETWORKS permission. It always
// should, since it couldn't become the active scorer otherwise, but this can't hurt.
return context.checkCallingPermission(Manifest.permission.SCORE_NETWORKS) ==
PackageManager.PERMISSION_GRANTED;
}
/** Returns the {@link NetworkScorerAppData} for the given app, or null if it's not a scorer. */
public static NetworkScorerAppData getScorer(Context context, String packageName) {
if (TextUtils.isEmpty(packageName)) {
return null;
}
Collection<NetworkScorerAppData> applications = getAllValidScorers(context);
for (NetworkScorerAppData app : applications) {
if (packageName.equals(app.mPackageName)) {
return app;
}
}
return null;
}
}
|
