| /* |
| * 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.connectivity; |
| |
| import static android.Manifest.permission.CHANGE_NETWORK_STATE; |
| import static android.Manifest.permission.CONNECTIVITY_INTERNAL; |
| import static android.Manifest.permission.CONNECTIVITY_USE_RESTRICTED_NETWORKS; |
| import static android.Manifest.permission.NETWORK_STACK; |
| import static android.content.pm.ApplicationInfo.FLAG_SYSTEM; |
| import static android.content.pm.ApplicationInfo.FLAG_UPDATED_SYSTEM_APP; |
| import static android.content.pm.PackageManager.GET_PERMISSIONS; |
| |
| import android.content.BroadcastReceiver; |
| import android.content.Context; |
| import android.content.Intent; |
| import android.content.IntentFilter; |
| import android.content.pm.ApplicationInfo; |
| import android.content.pm.PackageInfo; |
| import android.content.pm.PackageManager; |
| import android.content.pm.PackageManager.NameNotFoundException; |
| import android.content.pm.UserInfo; |
| import android.net.Uri; |
| import android.os.INetworkManagementService; |
| import android.os.RemoteException; |
| import android.os.UserHandle; |
| import android.os.UserManager; |
| import android.text.TextUtils; |
| import android.util.Log; |
| |
| import com.android.internal.annotations.VisibleForTesting; |
| |
| import java.util.ArrayList; |
| import java.util.HashMap; |
| import java.util.HashSet; |
| import java.util.List; |
| import java.util.Map.Entry; |
| import java.util.Map; |
| import java.util.Set; |
| |
| /** |
| * A utility class to inform Netd of UID permisisons. |
| * Does a mass update at boot and then monitors for app install/remove. |
| * |
| * @hide |
| */ |
| public class PermissionMonitor { |
| private static final String TAG = "PermissionMonitor"; |
| private static final boolean DBG = true; |
| private static final Boolean SYSTEM = Boolean.TRUE; |
| private static final Boolean NETWORK = Boolean.FALSE; |
| |
| private final Context mContext; |
| private final PackageManager mPackageManager; |
| private final UserManager mUserManager; |
| private final INetworkManagementService mNetd; |
| private final BroadcastReceiver mIntentReceiver; |
| |
| // Values are User IDs. |
| private final Set<Integer> mUsers = new HashSet<>(); |
| |
| // Keys are App IDs. Values are true for SYSTEM permission and false for NETWORK permission. |
| private final Map<Integer, Boolean> mApps = new HashMap<>(); |
| |
| public PermissionMonitor(Context context, INetworkManagementService netd) { |
| mContext = context; |
| mPackageManager = context.getPackageManager(); |
| mUserManager = UserManager.get(context); |
| mNetd = netd; |
| mIntentReceiver = new BroadcastReceiver() { |
| @Override |
| public void onReceive(Context context, Intent intent) { |
| String action = intent.getAction(); |
| int user = intent.getIntExtra(Intent.EXTRA_USER_HANDLE, UserHandle.USER_NULL); |
| int appUid = intent.getIntExtra(Intent.EXTRA_UID, -1); |
| Uri appData = intent.getData(); |
| String appName = appData != null ? appData.getSchemeSpecificPart() : null; |
| |
| if (Intent.ACTION_USER_ADDED.equals(action)) { |
| onUserAdded(user); |
| } else if (Intent.ACTION_USER_REMOVED.equals(action)) { |
| onUserRemoved(user); |
| } else if (Intent.ACTION_PACKAGE_ADDED.equals(action)) { |
| onAppAdded(appName, appUid); |
| } else if (Intent.ACTION_PACKAGE_REMOVED.equals(action)) { |
| onAppRemoved(appUid); |
| } |
| } |
| }; |
| } |
| |
| // Intended to be called only once at startup, after the system is ready. Installs a broadcast |
| // receiver to monitor ongoing UID changes, so this shouldn't/needn't be called again. |
| public synchronized void startMonitoring() { |
| log("Monitoring"); |
| |
| IntentFilter intentFilter = new IntentFilter(); |
| intentFilter.addAction(Intent.ACTION_USER_ADDED); |
| intentFilter.addAction(Intent.ACTION_USER_REMOVED); |
| mContext.registerReceiverAsUser(mIntentReceiver, UserHandle.ALL, intentFilter, null, null); |
| |
| intentFilter = new IntentFilter(); |
| intentFilter.addAction(Intent.ACTION_PACKAGE_ADDED); |
| intentFilter.addAction(Intent.ACTION_PACKAGE_REMOVED); |
| intentFilter.addDataScheme("package"); |
| mContext.registerReceiverAsUser(mIntentReceiver, UserHandle.ALL, intentFilter, null, null); |
| |
| List<PackageInfo> apps = mPackageManager.getInstalledPackages(GET_PERMISSIONS); |
| if (apps == null) { |
| loge("No apps"); |
| return; |
| } |
| |
| for (PackageInfo app : apps) { |
| int uid = app.applicationInfo != null ? app.applicationInfo.uid : -1; |
| if (uid < 0) { |
| continue; |
| } |
| |
| boolean isNetwork = hasNetworkPermission(app); |
| boolean hasRestrictedPermission = hasRestrictedNetworkPermission(app); |
| |
| if (isNetwork || hasRestrictedPermission) { |
| Boolean permission = mApps.get(uid); |
| // If multiple packages share a UID (cf: android:sharedUserId) and ask for different |
| // permissions, don't downgrade (i.e., if it's already SYSTEM, leave it as is). |
| if (permission == null || permission == NETWORK) { |
| mApps.put(uid, hasRestrictedPermission); |
| } |
| } |
| } |
| |
| List<UserInfo> users = mUserManager.getUsers(true); // exclude dying users |
| if (users != null) { |
| for (UserInfo user : users) { |
| mUsers.add(user.id); |
| } |
| } |
| |
| log("Users: " + mUsers.size() + ", Apps: " + mApps.size()); |
| update(mUsers, mApps, true); |
| } |
| |
| @VisibleForTesting |
| boolean isPreinstalledSystemApp(PackageInfo app) { |
| int flags = app.applicationInfo != null ? app.applicationInfo.flags : 0; |
| return (flags & (FLAG_SYSTEM | FLAG_UPDATED_SYSTEM_APP)) != 0; |
| } |
| |
| @VisibleForTesting |
| boolean hasPermission(PackageInfo app, String permission) { |
| if (app.requestedPermissions != null) { |
| for (String p : app.requestedPermissions) { |
| if (permission.equals(p)) { |
| return true; |
| } |
| } |
| } |
| return false; |
| } |
| |
| private boolean hasNetworkPermission(PackageInfo app) { |
| return hasPermission(app, CHANGE_NETWORK_STATE); |
| } |
| |
| private boolean hasRestrictedNetworkPermission(PackageInfo app) { |
| if (isPreinstalledSystemApp(app)) return true; |
| return hasPermission(app, CONNECTIVITY_INTERNAL) |
| || hasPermission(app, CONNECTIVITY_USE_RESTRICTED_NETWORKS); |
| } |
| |
| private boolean hasUseBackgroundNetworksPermission(PackageInfo app) { |
| // This function defines what it means to hold the permission to use |
| // background networks. |
| return hasPermission(app, CHANGE_NETWORK_STATE) |
| || hasPermission(app, CONNECTIVITY_USE_RESTRICTED_NETWORKS) |
| || hasPermission(app, CONNECTIVITY_INTERNAL) |
| || hasPermission(app, NETWORK_STACK) |
| // TODO : remove this check (b/31479477). Not all preinstalled apps should |
| // have access to background networks, they should just request the appropriate |
| // permission for their use case from the list above. |
| || isPreinstalledSystemApp(app); |
| } |
| |
| public boolean hasUseBackgroundNetworksPermission(int uid) { |
| final String[] names = mPackageManager.getPackagesForUid(uid); |
| if (null == names || names.length == 0) return false; |
| try { |
| // Only using the first package name. There may be multiple names if multiple |
| // apps share the same UID, but in that case they also share permissions so |
| // querying with any of the names will return the same results. |
| final PackageInfo app = mPackageManager.getPackageInfo(names[0], GET_PERMISSIONS); |
| return hasUseBackgroundNetworksPermission(app); |
| } catch (NameNotFoundException e) { |
| // App not found. |
| loge("NameNotFoundException " + names[0], e); |
| return false; |
| } |
| } |
| |
| private int[] toIntArray(List<Integer> list) { |
| int[] array = new int[list.size()]; |
| for (int i = 0; i < list.size(); i++) { |
| array[i] = list.get(i); |
| } |
| return array; |
| } |
| |
| private void update(Set<Integer> users, Map<Integer, Boolean> apps, boolean add) { |
| List<Integer> network = new ArrayList<>(); |
| List<Integer> system = new ArrayList<>(); |
| for (Entry<Integer, Boolean> app : apps.entrySet()) { |
| List<Integer> list = app.getValue() ? system : network; |
| for (int user : users) { |
| list.add(UserHandle.getUid(user, app.getKey())); |
| } |
| } |
| try { |
| if (add) { |
| mNetd.setPermission("NETWORK", toIntArray(network)); |
| mNetd.setPermission("SYSTEM", toIntArray(system)); |
| } else { |
| mNetd.clearPermission(toIntArray(network)); |
| mNetd.clearPermission(toIntArray(system)); |
| } |
| } catch (RemoteException e) { |
| loge("Exception when updating permissions: " + e); |
| } |
| } |
| |
| private synchronized void onUserAdded(int user) { |
| if (user < 0) { |
| loge("Invalid user in onUserAdded: " + user); |
| return; |
| } |
| mUsers.add(user); |
| |
| Set<Integer> users = new HashSet<>(); |
| users.add(user); |
| update(users, mApps, true); |
| } |
| |
| private synchronized void onUserRemoved(int user) { |
| if (user < 0) { |
| loge("Invalid user in onUserRemoved: " + user); |
| return; |
| } |
| mUsers.remove(user); |
| |
| Set<Integer> users = new HashSet<>(); |
| users.add(user); |
| update(users, mApps, false); |
| } |
| |
| |
| private Boolean highestPermissionForUid(Boolean currentPermission, String name) { |
| if (currentPermission == SYSTEM) { |
| return currentPermission; |
| } |
| try { |
| final PackageInfo app = mPackageManager.getPackageInfo(name, GET_PERMISSIONS); |
| final boolean isNetwork = hasNetworkPermission(app); |
| final boolean hasRestrictedPermission = hasRestrictedNetworkPermission(app); |
| if (isNetwork || hasRestrictedPermission) { |
| currentPermission = hasRestrictedPermission; |
| } |
| } catch (NameNotFoundException e) { |
| // App not found. |
| loge("NameNotFoundException " + name); |
| } |
| return currentPermission; |
| } |
| |
| private synchronized void onAppAdded(String appName, int appUid) { |
| if (TextUtils.isEmpty(appName) || appUid < 0) { |
| loge("Invalid app in onAppAdded: " + appName + " | " + appUid); |
| return; |
| } |
| |
| // If multiple packages share a UID (cf: android:sharedUserId) and ask for different |
| // permissions, don't downgrade (i.e., if it's already SYSTEM, leave it as is). |
| final Boolean permission = highestPermissionForUid(mApps.get(appUid), appName); |
| if (permission != mApps.get(appUid)) { |
| mApps.put(appUid, permission); |
| |
| Map<Integer, Boolean> apps = new HashMap<>(); |
| apps.put(appUid, permission); |
| update(mUsers, apps, true); |
| } |
| } |
| |
| private synchronized void onAppRemoved(int appUid) { |
| if (appUid < 0) { |
| loge("Invalid app in onAppRemoved: " + appUid); |
| return; |
| } |
| Map<Integer, Boolean> apps = new HashMap<>(); |
| |
| Boolean permission = null; |
| String[] packages = mPackageManager.getPackagesForUid(appUid); |
| if (packages != null && packages.length > 0) { |
| for (String name : packages) { |
| permission = highestPermissionForUid(permission, name); |
| if (permission == SYSTEM) { |
| // An app with this UID still has the SYSTEM permission. |
| // Therefore, this UID must already have the SYSTEM permission. |
| // Nothing to do. |
| return; |
| } |
| } |
| } |
| if (permission == mApps.get(appUid)) { |
| // The permissions of this UID have not changed. Nothing to do. |
| return; |
| } else if (permission != null) { |
| mApps.put(appUid, permission); |
| apps.put(appUid, permission); |
| update(mUsers, apps, true); |
| } else { |
| mApps.remove(appUid); |
| apps.put(appUid, NETWORK); // doesn't matter which permission we pick here |
| update(mUsers, apps, false); |
| } |
| } |
| |
| private static void log(String s) { |
| if (DBG) { |
| Log.d(TAG, s); |
| } |
| } |
| |
| private static void loge(String s) { |
| Log.e(TAG, s); |
| } |
| |
| private static void loge(String s, Throwable e) { |
| Log.e(TAG, s, e); |
| } |
| } |