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 * If the {@code type} parameter indicates that the result should be a directory, 69 * the socket parameter may be {@code null}; even if it is valid, no data will be 70 * read from it in this case. 71 * <p> 72 * If the {@code mode} argument is negative, then the resulting output file will not 73 * have its access mode or last modification time reset as part of this operation. 74 * 75 * @param data Socket supplying the data to be copied to the output file. If the 76 * output is a directory, this may be {@code null}. 77 * @param size Number of bytes of data to copy from the socket to the file. At least 78 * this much data must be available through the {@code data} parameter. 79 * @param type Must be either {@link BackupAgent#TYPE_FILE} for ordinary file data 80 * or {@link BackupAgent#TYPE_DIRECTORY} for a directory. 81 * @param mode Unix-style file mode (as used by the chmod(2) syscall) to be set on 82 * the output file or directory. If this parameter is negative then neither 83 * the mode nor the mtime parameters will be used. 84 * @param mtime A timestamp in the standard Unix epoch that will be imposed as the 85 * last modification time of the output file. if the {@code mode} parameter is 86 * negative then this parameter will be ignored. 87 * @param outFile Location within the filesystem to place the data. This must point 88 * to a location that is writeable by the caller, prefereably using an absolute path. 89 * @throws IOException 90 */ 91 static public void restoreFile(ParcelFileDescriptor data, 92 long size, int type, long mode, long mtime, File outFile) throws IOException { 93 if (type == BackupAgent.TYPE_DIRECTORY) { 94 // Canonically a directory has no associated content, so we don't need to read 95 // anything from the pipe in this case. Just create the directory here and 96 // drop down to the final metadata adjustment. 97 if (outFile != null) outFile.mkdirs(); 98 } else { 99 FileOutputStream out = null; 100 101 // Pull the data from the pipe, copying it to the output file, until we're done 102 try { 103 if (outFile != null) { 104 File parent = outFile.getParentFile(); 105 if (!parent.exists()) { 106 // in practice this will only be for the default semantic directories, 107 // and using the default mode for those is appropriate. 108 // TODO: support the edge case of apps that have adjusted the 109 // permissions on these core directories 110 parent.mkdirs(); 111 } 112 out = new FileOutputStream(outFile); 113 } 114 } catch (IOException e) { 115 Log.e(TAG, "Unable to create/open file " + outFile.getPath(), e); 116 } 117 118 byte[] buffer = new byte[32 * 1024]; 119 final long origSize = size; 120 FileInputStream in = new FileInputStream(data.getFileDescriptor()); 121 while (size > 0) { 122 int toRead = (size > buffer.length) ? buffer.length : (int)size; 123 int got = in.read(buffer, 0, toRead); 124 if (got <= 0) { 125 Log.w(TAG, "Incomplete read: expected " + size + " but got " 126 + (origSize - size)); 127 break; 128 } 129 if (out != null) { 130 try { 131 out.write(buffer, 0, got); 132 } catch (IOException e) { 133 // Problem writing to the file. Quit copying data and delete 134 // the file, but of course keep consuming the input stream. 135 Log.e(TAG, "Unable to write to file " + outFile.getPath(), e); 136 out.close(); 137 out = null; 138 outFile.delete(); 139 } 140 } 141 size -= got; 142 } 143 if (out != null) out.close(); 144 } 145 146 // Now twiddle the state to match the backup, assuming all went well 147 if (mode >= 0 && outFile != null) { 148 try { 149 Libcore.os.chmod(outFile.getPath(), (int)mode); 150 } catch (ErrnoException e) { 151 e.rethrowAsIOException(); 152 } 153 outFile.setLastModified(mtime); 154 } 155 } 156 } 157
