1 /* 2 * Copyright (C) 2017 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.server.backup.utils; 18 19 import static com.android.server.backup.BackupManagerService.BACKUP_MANIFEST_VERSION; 20 import static com.android.server.backup.BackupManagerService.TAG; 21 22 import android.content.pm.PackageInfo; 23 import android.content.pm.PackageManager; 24 import android.content.pm.Signature; 25 import android.content.pm.SigningInfo; 26 import android.os.Build; 27 import android.os.ParcelFileDescriptor; 28 import android.util.Slog; 29 import android.util.StringBuilderPrinter; 30 31 import java.io.DataInputStream; 32 import java.io.EOFException; 33 import java.io.File; 34 import java.io.FileInputStream; 35 import java.io.FileOutputStream; 36 import java.io.IOException; 37 import java.io.OutputStream; 38 39 /** 40 * Low-level utility methods for full backup. 41 */ 42 public class FullBackupUtils { 43 /** 44 * Reads data from pipe and writes it to the stream in chunks of up to 32KB. 45 * 46 * @param inPipe - pipe to read the data from. 47 * @param out - stream to write the data to. 48 * @throws IOException - in case of an error. 49 */ 50 public static void routeSocketDataToOutput(ParcelFileDescriptor inPipe, OutputStream out) 51 throws IOException { 52 // We do not take close() responsibility for the pipe FD 53 FileInputStream raw = new FileInputStream(inPipe.getFileDescriptor()); 54 DataInputStream in = new DataInputStream(raw); 55 56 byte[] buffer = new byte[32 * 1024]; 57 int chunkTotal; 58 while ((chunkTotal = in.readInt()) > 0) { 59 while (chunkTotal > 0) { 60 int toRead = (chunkTotal > buffer.length) ? buffer.length : chunkTotal; 61 int nRead = in.read(buffer, 0, toRead); 62 if (nRead < 0) { 63 Slog.e(TAG, "Unexpectedly reached end of file while reading data"); 64 throw new EOFException(); 65 } 66 out.write(buffer, 0, nRead); 67 chunkTotal -= nRead; 68 } 69 } 70 } 71 72 /** 73 * Writes app manifest to the given manifest file. 74 * 75 * @param pkg - app package, which manifest to write. 76 * @param packageManager - {@link PackageManager} instance. 77 * @param manifestFile - target manifest file. 78 * @param withApk - whether include apk or not. 79 * @param withWidgets - whether to write widgets data. 80 * @throws IOException - in case of an error. 81 */ 82 // TODO: withWidgets is not used, decide whether it is needed. 83 public static void writeAppManifest(PackageInfo pkg, PackageManager packageManager, 84 File manifestFile, boolean withApk, boolean withWidgets) throws IOException { 85 // Manifest format. All data are strings ending in LF: 86 // BACKUP_MANIFEST_VERSION, currently 1 87 // 88 // Version 1: 89 // package name 90 // package's versionCode 91 // platform versionCode 92 // getInstallerPackageName() for this package (maybe empty) 93 // boolean: "1" if archive includes .apk; any other string means not 94 // number of signatures == N 95 // N*: signature byte array in ascii format per Signature.toCharsString() 96 StringBuilder builder = new StringBuilder(4096); 97 StringBuilderPrinter printer = new StringBuilderPrinter(builder); 98 99 printer.println(Integer.toString(BACKUP_MANIFEST_VERSION)); 100 printer.println(pkg.packageName); 101 printer.println(Long.toString(pkg.getLongVersionCode())); 102 printer.println(Integer.toString(Build.VERSION.SDK_INT)); 103 104 String installerName = packageManager.getInstallerPackageName(pkg.packageName); 105 printer.println((installerName != null) ? installerName : ""); 106 107 printer.println(withApk ? "1" : "0"); 108 109 // write the signature block 110 SigningInfo signingInfo = pkg.signingInfo; 111 if (signingInfo == null) { 112 printer.println("0"); 113 } else { 114 // retrieve the newest sigs to write 115 // TODO (b/73988180) use entire signing history in case of rollbacks 116 Signature[] signatures = signingInfo.getApkContentsSigners(); 117 printer.println(Integer.toString(signatures.length)); 118 for (Signature sig : signatures) { 119 printer.println(sig.toCharsString()); 120 } 121 } 122 123 FileOutputStream outstream = new FileOutputStream(manifestFile); 124 outstream.write(builder.toString().getBytes()); 125 outstream.close(); 126 127 // We want the manifest block in the archive stream to be idempotent: 128 // each time we generate a backup stream for the app, we want the manifest 129 // block to be identical. The underlying tar mechanism sees it as a file, 130 // though, and will propagate its mtime, causing the tar header to vary. 131 // Avoid this problem by pinning the mtime to zero. 132 manifestFile.setLastModified(0); 133 } 134 } 135
