Jeff Davidson | dd6fd1e | 2014-04-14 15:14:30 -0700 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright (C) 2014 The Android Open Source Project |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License |
| 15 | */ |
| 16 | |
| 17 | package android.net; |
| 18 | |
| 19 | import android.Manifest.permission; |
| 20 | import android.app.AppOpsManager; |
| 21 | import android.content.Context; |
| 22 | import android.content.Intent; |
| 23 | import android.content.pm.ActivityInfo; |
| 24 | import android.content.pm.PackageManager; |
| 25 | import android.content.pm.ResolveInfo; |
| 26 | import android.provider.Settings; |
| 27 | import android.provider.Settings.Global; |
| 28 | import android.text.TextUtils; |
| 29 | |
| 30 | import java.util.ArrayList; |
| 31 | import java.util.Collection; |
| 32 | import java.util.List; |
| 33 | |
| 34 | /** |
| 35 | * Internal class for managing the primary network scorer application. |
| 36 | * |
| 37 | * @hide |
| 38 | */ |
| 39 | public final class NetworkScorerApplication { |
| 40 | |
| 41 | private static final Intent SCORE_INTENT = |
| 42 | new Intent(NetworkScoreManager.ACTION_SCORE_NETWORKS); |
| 43 | |
| 44 | /** This class cannot be instantiated. */ |
| 45 | private NetworkScorerApplication() {} |
| 46 | |
| 47 | /** |
| 48 | * Returns the list of available scorer app package names. |
| 49 | * |
| 50 | * <p>A network scorer is any application which: |
| 51 | * <ul> |
| 52 | * <li>Declares the {@link android.Manifest.permission#SCORE_NETWORKS} permission. |
| 53 | * <li>Includes a receiver for {@link NetworkScoreManager#ACTION_SCORE_NETWORKS} guarded by the |
| 54 | * {@link android.Manifest.permission#BROADCAST_SCORE_NETWORKS} permission. |
| 55 | * </ul> |
| 56 | * |
| 57 | * @return the list of scorers, or the empty list if there are no valid scorers. |
| 58 | */ |
| 59 | public static Collection<String> getAllValidScorers(Context context) { |
| 60 | List<String> scorers = new ArrayList<>(); |
| 61 | |
| 62 | PackageManager pm = context.getPackageManager(); |
| 63 | List<ResolveInfo> receivers = pm.queryBroadcastReceivers(SCORE_INTENT, 0 /* flags */); |
| 64 | for (ResolveInfo receiver : receivers) { |
| 65 | // This field is a misnomer, see android.content.pm.ResolveInfo#activityInfo |
| 66 | final ActivityInfo receiverInfo = receiver.activityInfo; |
| 67 | if (receiverInfo == null) { |
| 68 | // Should never happen with queryBroadcastReceivers, but invalid nonetheless. |
| 69 | continue; |
| 70 | } |
| 71 | if (!permission.BROADCAST_SCORE_NETWORKS.equals(receiverInfo.permission)) { |
| 72 | // Receiver doesn't require the BROADCAST_SCORE_NETWORKS permission, which means |
| 73 | // anyone could trigger network scoring and flood the framework with score requests. |
| 74 | continue; |
| 75 | } |
| 76 | if (pm.checkPermission(permission.SCORE_NETWORKS, receiverInfo.packageName) != |
| 77 | PackageManager.PERMISSION_GRANTED) { |
| 78 | // Application doesn't hold the SCORE_NETWORKS permission, so the user never |
| 79 | // approved it as a network scorer. |
| 80 | continue; |
| 81 | } |
| 82 | scorers.add(receiverInfo.packageName); |
| 83 | } |
| 84 | |
| 85 | return scorers; |
| 86 | } |
| 87 | |
| 88 | /** |
| 89 | * Get the application package name to use for scoring networks. |
| 90 | * |
| 91 | * @return the scorer package or null if scoring is disabled (including if no scorer was ever |
| 92 | * selected) or if the previously-set scorer is no longer a valid scorer app (e.g. because |
| 93 | * it was disabled or uninstalled). |
| 94 | */ |
| 95 | public static String getActiveScorer(Context context) { |
| 96 | String scorerPackage = Settings.Global.getString(context.getContentResolver(), |
| 97 | Global.NETWORK_SCORER_APP); |
| 98 | Collection<String> applications = getAllValidScorers(context); |
| 99 | if (isPackageValidScorer(applications, scorerPackage)) { |
| 100 | return scorerPackage; |
| 101 | } else { |
| 102 | return null; |
| 103 | } |
| 104 | } |
| 105 | |
| 106 | /** |
| 107 | * Set the specified package as the default scorer application. |
| 108 | * |
| 109 | * <p>The caller must have permission to write to {@link Settings.Global}. |
| 110 | * |
| 111 | * @param context the context of the calling application |
| 112 | * @param packageName the packageName of the new scorer to use. If null, scoring will be |
| 113 | * disabled. Otherwise, the scorer will only be set if it is a valid scorer application. |
| 114 | */ |
| 115 | public static void setActiveScorer(Context context, String packageName) { |
| 116 | String oldPackageName = Settings.Global.getString(context.getContentResolver(), |
| 117 | Settings.Global.NETWORK_SCORER_APP); |
| 118 | if (TextUtils.equals(oldPackageName, packageName)) { |
| 119 | // No change. |
| 120 | return; |
| 121 | } |
| 122 | |
| 123 | if (packageName == null) { |
| 124 | Settings.Global.putString(context.getContentResolver(), Global.NETWORK_SCORER_APP, |
| 125 | null); |
| 126 | } else { |
| 127 | // We only make the change if the new package is valid. |
| 128 | Collection<String> applications = getAllValidScorers(context); |
| 129 | if (isPackageValidScorer(applications, packageName)) { |
| 130 | Settings.Global.putString(context.getContentResolver(), |
| 131 | Settings.Global.NETWORK_SCORER_APP, packageName); |
| 132 | } |
| 133 | } |
| 134 | } |
| 135 | |
| 136 | /** Determine whether the application with the given UID is the enabled scorer. */ |
| 137 | public static boolean isCallerDefaultScorer(Context context, int callingUid) { |
| 138 | String defaultApp = getActiveScorer(context); |
| 139 | if (defaultApp == null) { |
| 140 | return false; |
| 141 | } |
| 142 | AppOpsManager appOpsMgr = (AppOpsManager) context.getSystemService(Context.APP_OPS_SERVICE); |
| 143 | try { |
| 144 | appOpsMgr.checkPackage(callingUid, defaultApp); |
| 145 | return true; |
| 146 | } catch (SecurityException e) { |
| 147 | return false; |
| 148 | } |
| 149 | } |
| 150 | |
| 151 | /** Returns true if the given package is a valid scorer. */ |
| 152 | private static boolean isPackageValidScorer(Collection<String> scorerPackageNames, |
| 153 | String packageName) { |
| 154 | return packageName != null && scorerPackageNames.contains(packageName); |
| 155 | } |
| 156 | } |