1 /* 2 * Copyright (C) 2011 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.app.backup; 18 19 import android.content.Context; 20 import android.content.pm.ApplicationInfo; 21 import android.content.pm.PackageManager; 22 import android.os.ParcelFileDescriptor; 23 import android.util.Log; 24 25 import java.io.File; 26 import java.io.FileInputStream; 27 import java.io.FileOutputStream; 28 import java.io.IOException; 29 30 import libcore.io.ErrnoException; 31 import libcore.io.Libcore; 32 33 /** 34 * Global constant definitions et cetera related to the full-backup-to-fd 35 * binary format. Nothing in this namespace is part of any API; it's all 36 * hidden details of the current implementation gathered into one location. 37 * 38 * @hide 39 */ 40 public class FullBackup { 41 static final String TAG = "FullBackup"; 42 43 public static final String APK_TREE_TOKEN = "a"; 44 public static final String OBB_TREE_TOKEN = "obb"; 45 public static final String ROOT_TREE_TOKEN = "r"; 46 public static final String DATA_TREE_TOKEN = "f"; 47 public static final String DATABASE_TREE_TOKEN = "db"; 48 public static final String SHAREDPREFS_TREE_TOKEN = "sp"; 49 public static final String CACHE_TREE_TOKEN = "c"; 50 public static final String SHARED_STORAGE_TOKEN = "shared"; 51 52 public static final String APPS_PREFIX = "apps/"; 53 public static final String SHARED_PREFIX = SHARED_STORAGE_TOKEN + "/"; 54 55 public static final String FULL_BACKUP_INTENT_ACTION = "fullback"; 56 public static final String FULL_RESTORE_INTENT_ACTION = "fullrest"; 57 public static final String CONF_TOKEN_INTENT_EXTRA = "conftoken"; 58 59 /** 60 * @hide 61 */ 62 static public native int backupToTar(String packageName, String domain, 63 String linkdomain, String rootpath, String path, BackupDataOutput output); 64 65 /** 66 * Copy data from a socket to the given File location on permanent storage. The 67 * modification time and access mode of the resulting file will be set if desired, 68 * although group/all rwx modes will be stripped: the restored file will not be 69 * accessible from outside the target application even if the original file was. 70 * If the {@code type} parameter indicates that the result should be a directory, 71 * the socket parameter may be {@code null}; even if it is valid, no data will be 72 * read from it in this case. 73 * <p> 74 * If the {@code mode} argument is negative, then the resulting output file will not 75 * have its access mode or last modification time reset as part of this operation. 76 * 77 * @param data Socket supplying the data to be copied to the output file. If the 78 * output is a directory, this may be {@code null}. 79 * @param size Number of bytes of data to copy from the socket to the file. At least 80 * this much data must be available through the {@code data} parameter. 81 * @param type Must be either {@link BackupAgent#TYPE_FILE} for ordinary file data 82 * or {@link BackupAgent#TYPE_DIRECTORY} for a directory. 83 * @param mode Unix-style file mode (as used by the chmod(2) syscall) to be set on 84 * the output file or directory. group/all rwx modes are stripped even if set 85 * in this parameter. If this parameter is negative then neither 86 * the mode nor the mtime values will be applied to the restored file. 87 * @param mtime A timestamp in the standard Unix epoch that will be imposed as the 88 * last modification time of the output file. if the {@code mode} parameter is 89 * negative then this parameter will be ignored. 90 * @param outFile Location within the filesystem to place the data. This must point 91 * to a location that is writeable by the caller, prefereably using an absolute path. 92 * @throws IOException 93 */ 94 static public void restoreFile(ParcelFileDescriptor data, 95 long size, int type, long mode, long mtime, File outFile) throws IOException { 96 if (type == BackupAgent.TYPE_DIRECTORY) { 97 // Canonically a directory has no associated content, so we don't need to read 98 // anything from the pipe in this case. Just create the directory here and 99 // drop down to the final metadata adjustment. 100 if (outFile != null) outFile.mkdirs(); 101 } else { 102 FileOutputStream out = null; 103 104 // Pull the data from the pipe, copying it to the output file, until we're done 105 try { 106 if (outFile != null) { 107 File parent = outFile.getParentFile(); 108 if (!parent.exists()) { 109 // in practice this will only be for the default semantic directories, 110 // and using the default mode for those is appropriate. 111 parent.mkdirs(); 112 } 113 out = new FileOutputStream(outFile); 114 } 115 } catch (IOException e) { 116 Log.e(TAG, "Unable to create/open file " + outFile.getPath(), e); 117 } 118 119 byte[] buffer = new byte[32 * 1024]; 120 final long origSize = size; 121 FileInputStream in = new FileInputStream(data.getFileDescriptor()); 122 while (size > 0) { 123 int toRead = (size > buffer.length) ? buffer.length : (int)size; 124 int got = in.read(buffer, 0, toRead); 125 if (got <= 0) { 126 Log.w(TAG, "Incomplete read: expected " + size + " but got " 127 + (origSize - size)); 128 break; 129 } 130 if (out != null) { 131 try { 132 out.write(buffer, 0, got); 133 } catch (IOException e) { 134 // Problem writing to the file. Quit copying data and delete 135 // the file, but of course keep consuming the input stream. 136 Log.e(TAG, "Unable to write to file " + outFile.getPath(), e); 137 out.close(); 138 out = null; 139 outFile.delete(); 140 } 141 } 142 size -= got; 143 } 144 if (out != null) out.close(); 145 } 146 147 // Now twiddle the state to match the backup, assuming all went well 148 if (mode >= 0 && outFile != null) { 149 try { 150 // explicitly prevent emplacement of files accessible by outside apps 151 mode &= 0700; 152 Libcore.os.chmod(outFile.getPath(), (int)mode); 153 } catch (ErrnoException e) { 154 e.rethrowAsIOException(); 155 } 156 outFile.setLastModified(mtime); 157 } 158 } 159 } 160
