| /* |
| * Copyright (C) 2016 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.wifi.util; |
| |
| import android.Manifest; |
| import android.app.AppOpsManager; |
| import android.content.Context; |
| import android.content.pm.PackageManager; |
| import android.content.pm.UserInfo; |
| import android.net.ConnectivityManager; |
| import android.net.NetworkScoreManager; |
| import android.os.Binder; |
| import android.os.RemoteException; |
| import android.os.UserManager; |
| import android.provider.Settings; |
| |
| import com.android.server.wifi.WifiInjector; |
| import com.android.server.wifi.WifiLog; |
| import com.android.server.wifi.WifiSettingsStore; |
| |
| import java.util.List; |
| |
| /** |
| * A wifi permissions utility assessing permissions |
| * for getting scan results by a package. |
| */ |
| public class WifiPermissionsUtil { |
| private static final String TAG = "WifiPermissionsUtil"; |
| private final WifiPermissionsWrapper mWifiPermissionsWrapper; |
| private final Context mContext; |
| private final AppOpsManager mAppOps; |
| private final UserManager mUserManager; |
| private final WifiSettingsStore mSettingsStore; |
| private final NetworkScoreManager mNetworkScoreManager; |
| private WifiLog mLog; |
| |
| public WifiPermissionsUtil(WifiPermissionsWrapper wifiPermissionsWrapper, |
| Context context, WifiSettingsStore settingsStore, UserManager userManager, |
| NetworkScoreManager networkScoreManager, WifiInjector wifiInjector) { |
| mWifiPermissionsWrapper = wifiPermissionsWrapper; |
| mContext = context; |
| mUserManager = userManager; |
| mAppOps = (AppOpsManager) mContext.getSystemService(Context.APP_OPS_SERVICE); |
| mSettingsStore = settingsStore; |
| mLog = wifiInjector.makeLog(TAG); |
| mNetworkScoreManager = networkScoreManager; |
| } |
| |
| /** |
| * Checks if the app has the permission to override Wi-Fi network configuration or not. |
| * |
| * @param uid uid of the app. |
| * @return true if the app does have the permission, false otherwise. |
| */ |
| public boolean checkConfigOverridePermission(int uid) { |
| try { |
| int permission = mWifiPermissionsWrapper.getOverrideWifiConfigPermission(uid); |
| return (permission == PackageManager.PERMISSION_GRANTED); |
| } catch (RemoteException e) { |
| mLog.err("Error checking for permission: %").r(e.getMessage()).flush(); |
| return false; |
| } |
| } |
| |
| /** |
| * Checks if the app has the permission to change Wi-Fi network configuration or not. |
| * |
| * @param uid uid of the app. |
| * @return true if the app does have the permission, false otherwise. |
| */ |
| public boolean checkChangePermission(int uid) { |
| try { |
| int permission = mWifiPermissionsWrapper.getChangeWifiConfigPermission(uid); |
| return (permission == PackageManager.PERMISSION_GRANTED); |
| } catch (RemoteException e) { |
| mLog.err("Error checking for permission: %").r(e.getMessage()).flush(); |
| return false; |
| } |
| } |
| |
| /** |
| * Check and enforce tether change permission. |
| * |
| * @param context Context object of the caller. |
| */ |
| public void enforceTetherChangePermission(Context context) { |
| String pkgName = context.getOpPackageName(); |
| ConnectivityManager.enforceTetherChangePermission(context, pkgName); |
| } |
| |
| /** |
| * Check and enforce Location permission. |
| * |
| * @param pkgName PackageName of the application requesting access |
| * @param uid The uid of the package |
| */ |
| public void enforceLocationPermission(String pkgName, int uid) { |
| if (!checkCallersLocationPermission(pkgName, uid)) { |
| throw new SecurityException("UID " + uid + " does not have Location permission"); |
| } |
| } |
| |
| |
| /** |
| * Checks that calling process has android.Manifest.permission.ACCESS_COARSE_LOCATION |
| * and a corresponding app op is allowed for this package and uid. |
| * |
| * @param pkgName PackageName of the application requesting access |
| * @param uid The uid of the package |
| */ |
| public boolean checkCallersLocationPermission(String pkgName, int uid) { |
| // Coarse Permission implies Fine permission |
| if ((mWifiPermissionsWrapper.getUidPermission( |
| Manifest.permission.ACCESS_COARSE_LOCATION, uid) |
| == PackageManager.PERMISSION_GRANTED) |
| && checkAppOpAllowed(AppOpsManager.OP_COARSE_LOCATION, pkgName, uid)) { |
| return true; |
| } |
| return false; |
| } |
| |
| /** |
| * API to determine if the caller has permissions to get |
| * scan results. |
| * @param pkgName package name of the application requesting access |
| * @param uid The uid of the package |
| * @param minVersion Minimum app API Version number to enforce location permission |
| * @return boolean true or false if permissions is granted |
| */ |
| public boolean canAccessScanResults(String pkgName, int uid, |
| int minVersion) throws SecurityException { |
| mAppOps.checkPackage(uid, pkgName); |
| // Check if the calling Uid has CAN_READ_PEER_MAC_ADDRESS |
| // permission or is an Active Nw scorer. |
| boolean canCallingUidAccessLocation = checkCallerHasPeersMacAddressPermission(uid) |
| || isCallerActiveNwScorer(uid); |
| // LocationAccess by App: For AppVersion older than minVersion, |
| // it is sufficient to check if the App is foreground. |
| // Otherwise, Location Mode must be enabled and caller must have |
| // Coarse Location permission to have access to location information. |
| boolean canAppPackageUseLocation = isLegacyForeground(pkgName, minVersion) |
| || (isLocationModeEnabled(pkgName) |
| && checkCallersLocationPermission(pkgName, uid)); |
| // If neither caller or app has location access, there is no need to check |
| // any other permissions. Deny access to scan results. |
| if (!canCallingUidAccessLocation && !canAppPackageUseLocation) { |
| mLog.tC("Denied: no location permission"); |
| return false; |
| } |
| // Check if Wifi Scan request is an operation allowed for this App. |
| if (!isScanAllowedbyApps(pkgName, uid)) { |
| mLog.tC("Denied: app wifi scan not allowed"); |
| return false; |
| } |
| // If the User or profile is current, permission is granted |
| // Otherwise, uid must have INTERACT_ACROSS_USERS_FULL permission. |
| if (!isCurrentProfile(uid) && !checkInteractAcrossUsersFull(uid)) { |
| mLog.tC("Denied: Profile not permitted"); |
| return false; |
| } |
| return true; |
| } |
| |
| /** |
| * Returns true if the caller holds PEERS_MAC_ADDRESS permission. |
| */ |
| private boolean checkCallerHasPeersMacAddressPermission(int uid) { |
| return mWifiPermissionsWrapper.getUidPermission( |
| android.Manifest.permission.PEERS_MAC_ADDRESS, uid) |
| == PackageManager.PERMISSION_GRANTED; |
| } |
| |
| /** |
| * Returns true if the caller is an Active Network Scorer. |
| */ |
| private boolean isCallerActiveNwScorer(int uid) { |
| return mNetworkScoreManager.isCallerActiveScorer(uid); |
| } |
| |
| /** |
| * Returns true if Wifi scan operation is allowed for this caller |
| * and package. |
| */ |
| private boolean isScanAllowedbyApps(String pkgName, int uid) { |
| return checkAppOpAllowed(AppOpsManager.OP_WIFI_SCAN, pkgName, uid); |
| } |
| |
| /** |
| * Returns true if the caller holds INTERACT_ACROSS_USERS_FULL. |
| */ |
| private boolean checkInteractAcrossUsersFull(int uid) { |
| return mWifiPermissionsWrapper.getUidPermission( |
| android.Manifest.permission.INTERACT_ACROSS_USERS_FULL, uid) |
| == PackageManager.PERMISSION_GRANTED; |
| } |
| |
| /** |
| * Returns true if the calling user is the current one or a profile of the |
| * current user. |
| */ |
| private boolean isCurrentProfile(int uid) { |
| final long token = Binder.clearCallingIdentity(); |
| try { |
| int currentUser = mWifiPermissionsWrapper.getCurrentUser(); |
| int callingUserId = mWifiPermissionsWrapper.getCallingUserId(uid); |
| if (callingUserId == currentUser) { |
| return true; |
| } else { |
| List<UserInfo> userProfiles = mUserManager.getProfiles(currentUser); |
| for (UserInfo user : userProfiles) { |
| if (user.id == callingUserId) { |
| return true; |
| } |
| } |
| } |
| return false; |
| } finally { |
| Binder.restoreCallingIdentity(token); |
| } |
| } |
| |
| /** |
| * Returns true if the App version is older than minVersion. |
| */ |
| private boolean isLegacyVersion(String pkgName, int minVersion) { |
| try { |
| if (mContext.getPackageManager().getApplicationInfo(pkgName, 0) |
| .targetSdkVersion < minVersion) { |
| return true; |
| } |
| } catch (PackageManager.NameNotFoundException e) { |
| // In case of exception, assume known app (more strict checking) |
| // Note: This case will never happen since checkPackage is |
| // called to verify valididity before checking App's version. |
| } |
| return false; |
| } |
| |
| private boolean checkAppOpAllowed(int op, String pkgName, int uid) { |
| return mAppOps.noteOp(op, uid, pkgName) == AppOpsManager.MODE_ALLOWED; |
| } |
| |
| private boolean isLegacyForeground(String pkgName, int version) { |
| return isLegacyVersion(pkgName, version) && isForegroundApp(pkgName); |
| } |
| |
| private boolean isForegroundApp(String pkgName) { |
| return pkgName.equals(mWifiPermissionsWrapper.getTopPkgName()); |
| } |
| |
| private boolean isLocationModeEnabled(String pkgName) { |
| // Location mode check on applications that are later than version. |
| return (mSettingsStore.getLocationModeSetting(mContext) |
| != Settings.Secure.LOCATION_MODE_OFF); |
| } |
| |
| /** |
| * Returns true if the |uid| holds NETWORK_SETTINGS permission. |
| */ |
| public boolean checkNetworkSettingsPermission(int uid) { |
| return mWifiPermissionsWrapper.getUidPermission( |
| android.Manifest.permission.NETWORK_SETTINGS, uid) |
| == PackageManager.PERMISSION_GRANTED; |
| } |
| } |