1 /* 2 * Copyright (C) 2020 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.content; 18 19 import android.annotation.NonNull; 20 import android.annotation.SystemApi; 21 import android.os.Environment; 22 import android.os.UserHandle; 23 24 import java.io.File; 25 import java.util.Objects; 26 27 /** 28 * Provides information about the environment for a particular APEX. 29 * 30 * @hide 31 */ 32 @SystemApi 33 public class ApexEnvironment { 34 35 private static final String APEX_DATA = "apexdata"; 36 37 /** 38 * Returns an ApexEnvironment instance for the APEX with the provided {@code apexModuleName}. 39 * 40 * <p>To preserve the safety and integrity of APEX modules, you must only obtain the 41 * ApexEnvironment for your specific APEX, and you <em>must never</em> attempt to obtain an 42 * ApexEnvironment for another APEX. Any coordination between APEXs must be performed through 43 * well-defined interfaces; attempting to directly read or write raw files belonging to another 44 * APEX will violate the hermetic storage requirements placed upon each module. 45 */ 46 @NonNull getApexEnvironment(@onNull String apexModuleName)47 public static ApexEnvironment getApexEnvironment(@NonNull String apexModuleName) { 48 Objects.requireNonNull(apexModuleName, "apexModuleName cannot be null"); 49 //TODO(b/141148175): Check that apexModuleName is an actual APEX name 50 return new ApexEnvironment(apexModuleName); 51 } 52 53 private final String mApexModuleName; 54 ApexEnvironment(String apexModuleName)55 private ApexEnvironment(String apexModuleName) { 56 mApexModuleName = apexModuleName; 57 } 58 59 /** 60 * Returns the data directory for the APEX in device-encrypted, non-user-specific storage. 61 * 62 * <p>This directory is automatically created by the system for installed APEXes, and its 63 * contents will be rolled back if the APEX is rolled back. 64 */ 65 @NonNull getDeviceProtectedDataDir()66 public File getDeviceProtectedDataDir() { 67 return Environment.buildPath( 68 Environment.getDataMiscDirectory(), APEX_DATA, mApexModuleName); 69 } 70 71 /** 72 * Returns the data directory for the APEX in device-encrypted, user-specific storage for the 73 * specified {@code user}. 74 * 75 * <p>This directory is automatically created by the system for each user and for each installed 76 * APEX, and its contents will be rolled back if the APEX is rolled back. 77 */ 78 @NonNull getDeviceProtectedDataDirForUser(@onNull UserHandle user)79 public File getDeviceProtectedDataDirForUser(@NonNull UserHandle user) { 80 return Environment.buildPath( 81 Environment.getDataMiscDeDirectory(user.getIdentifier()), APEX_DATA, 82 mApexModuleName); 83 } 84 85 /** 86 * Returns the data directory for the APEX in credential-encrypted, user-specific storage for 87 * the specified {@code user}. 88 * 89 * <p>This directory is automatically created by the system for each user and for each installed 90 * APEX, and its contents will be rolled back if the APEX is rolled back. 91 */ 92 @NonNull getCredentialProtectedDataDirForUser(@onNull UserHandle user)93 public File getCredentialProtectedDataDirForUser(@NonNull UserHandle user) { 94 return Environment.buildPath( 95 Environment.getDataMiscCeDirectory(user.getIdentifier()), APEX_DATA, 96 mApexModuleName); 97 } 98 } 99