1 /* 2 * Copyright (C) 2018 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 com.android.cts.install.lib.testapp; 18 19 import android.content.BroadcastReceiver; 20 import android.content.Context; 21 import android.content.Intent; 22 import android.content.res.Resources; 23 import android.os.Process; 24 import android.system.ErrnoException; 25 import android.system.Os; 26 27 import java.io.File; 28 import java.io.FileNotFoundException; 29 import java.io.IOException; 30 import java.io.PrintWriter; 31 import java.nio.charset.StandardCharsets; 32 import java.util.Scanner; 33 34 /** 35 * A broadcast receiver to check for and update user app data version 36 * and user handle compatibility. 37 */ 38 public class ProcessUserData extends BroadcastReceiver { 39 40 /** 41 * Exception thrown in case of issue with user data. 42 */ 43 public static class UserDataException extends Exception { UserDataException(String message)44 public UserDataException(String message) { 45 super(message); 46 } 47 UserDataException(String message, Throwable cause)48 public UserDataException(String message, Throwable cause) { 49 super(message, cause); 50 } 51 } 52 53 @Override onReceive(Context context, Intent intent)54 public void onReceive(Context context, Intent intent) { 55 if (intent.getAction().equals("PROCESS_USER_DATA")) { 56 try { 57 processUserData(context); 58 setResultCode(1); 59 } catch (UserDataException e) { 60 setResultCode(0); 61 setResultData(e.getMessage()); 62 } 63 } else if (intent.getAction().equals("GET_USER_DATA_VERSION")) { 64 setResultCode(getUserDataVersion(context)); 65 } 66 } 67 68 /** 69 * Update the app's user data version to match the app version, and confirm 70 * the user data is for the correct user. 71 * 72 * @param context The application context. 73 * @throws UserDataException in case of problems with app user data. 74 */ processUserData(Context context)75 public void processUserData(Context context) throws UserDataException { 76 Resources res = context.getResources(); 77 String packageName = context.getPackageName(); 78 79 String userHandle = Process.myUserHandle().toString(); 80 81 int appVersionId = res.getIdentifier("app_version", "integer", packageName); 82 int appVersion = res.getInteger(appVersionId); 83 84 int splitVersionId = res.getIdentifier("split_version", "integer", packageName); 85 int splitVersion = res.getInteger(splitVersionId); 86 87 // Make sure the app version and split versions are compatible. 88 if (appVersion != splitVersion) { 89 throw new UserDataException("Split version " + splitVersion 90 + " does not match app version " + appVersion); 91 } 92 93 // Read the version of the app's user data and ensure it is compatible 94 // with our version of the application. Also ensure that the user data is 95 // for the correct user. 96 File versionFile = new File(context.getFilesDir(), "userdata.txt"); 97 try { 98 Scanner s = new Scanner(versionFile); 99 int userDataVersion = s.nextInt(); 100 s.nextLine(); 101 102 if (userDataVersion > appVersion) { 103 throw new UserDataException("User data is from version " + userDataVersion 104 + ", which is not compatible with this version " + appVersion 105 + " of the RollbackTestApp"); 106 } 107 108 String readUserHandle = s.nextLine(); 109 s.close(); 110 111 if (!readUserHandle.equals(userHandle)) { 112 throw new UserDataException("User handle expected to be: " + userHandle 113 + ", but was actually " + readUserHandle); 114 } 115 116 int xattrVersion = Integer.valueOf( 117 new String(Os.getxattr(versionFile.getAbsolutePath(), "user.test"))); 118 119 if (xattrVersion > appVersion) { 120 throw new UserDataException("xattr data is from version " + xattrVersion 121 + ", which is not compatible with this version " + appVersion 122 + " of the RollbackTestApp"); 123 } 124 } catch (FileNotFoundException e) { 125 // No problem. This is a fresh install of the app or the user data 126 // has been wiped. 127 } catch (ErrnoException e) { 128 throw new UserDataException("Error while retrieving xattr.", e); 129 } 130 131 // Record the current version of the app in the user data. 132 try { 133 PrintWriter pw = new PrintWriter(versionFile); 134 pw.println(appVersion); 135 pw.println(userHandle); 136 pw.close(); 137 Os.setxattr(versionFile.getAbsolutePath(), "user.test", 138 Integer.toString(appVersion).getBytes(StandardCharsets.UTF_8), 0); 139 } catch (IOException e) { 140 throw new UserDataException("Unable to write user data.", e); 141 } catch (ErrnoException e) { 142 throw new UserDataException("Unable to set xattr.", e); 143 } 144 } 145 146 /** 147 * Return the app's user data version or -1 if userdata.txt doesn't exist. 148 */ getUserDataVersion(Context context)149 private int getUserDataVersion(Context context) { 150 File versionFile = new File(context.getFilesDir(), "userdata.txt"); 151 try (Scanner s = new Scanner(versionFile);) { 152 int dataVersion = s.nextInt(); 153 return dataVersion; 154 } catch (FileNotFoundException e) { 155 // No problem. This is a fresh install of the app or the user data 156 // has been wiped. 157 return -1; 158 } 159 } 160 } 161