/*
* Copyright (C) 2008 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.android.providers.settings;
import android.app.backup.BackupAgentHelper;
import android.app.backup.BackupDataInput;
import android.app.backup.BackupDataOutput;
import android.app.backup.FullBackupDataOutput;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.net.Uri;
import android.net.wifi.WifiManager;
import android.os.FileUtils;
import android.os.ParcelFileDescriptor;
import android.os.Process;
import android.provider.Settings;
import android.util.Log;
import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.EOFException;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.HashMap;
import java.util.Map;
import java.util.zip.CRC32;
/**
* Performs backup and restore of the System and Secure settings.
* List of settings that are backed up are stored in the Settings.java file
*/
public class SettingsBackupAgent extends BackupAgentHelper {
private static final boolean DEBUG = false;
private static final boolean DEBUG_BACKUP = DEBUG || true;
private static final String KEY_SYSTEM = "system";
private static final String KEY_SECURE = "secure";
private static final String KEY_LOCALE = "locale";
//Version 2 adds STATE_WIFI_CONFIG
private static final int STATE_VERSION_1 = 1;
private static final int STATE_VERSION_1_SIZE = 4;
// Versioning of the state file. Increment this version
// number any time the set of state items is altered.
private static final int STATE_VERSION = 2;
private static final int STATE_SYSTEM = 0;
private static final int STATE_SECURE = 1;
private static final int STATE_LOCALE = 2;
private static final int STATE_WIFI_SUPPLICANT = 3;
private static final int STATE_WIFI_CONFIG = 4;
private static final int STATE_SIZE = 5; // The number of state items
// Versioning of the 'full backup' format
private static final int FULL_BACKUP_VERSION = 1;
private static final int INTEGER_BYTE_COUNT = Integer.SIZE / Byte.SIZE;
private static final byte[] EMPTY_DATA = new byte[0];
private static final String TAG = "SettingsBackupAgent";
private static final int COLUMN_NAME = 1;
private static final int COLUMN_VALUE = 2;
private static final String[] PROJECTION = {
Settings.NameValueTable._ID,
Settings.NameValueTable.NAME,
Settings.NameValueTable.VALUE
};
private static final String FILE_WIFI_SUPPLICANT = "/data/misc/wifi/wpa_supplicant.conf";
private static final String FILE_WIFI_SUPPLICANT_TEMPLATE =
"/system/etc/wifi/wpa_supplicant.conf";
// the key to store the WIFI data under, should be sorted as last, so restore happens last.
// use very late unicode character to quasi-guarantee last sort position.
private static final String KEY_WIFI_SUPPLICANT = "\uffedWIFI";
private static final String KEY_WIFI_CONFIG = "\uffedCONFIG_WIFI";
// Name of the temporary file we use during full backup/restore. This is
// stored in the full-backup tarfile as well, so should not be changed.
private static final String STAGE_FILE = "flattened-data";
private SettingsHelper mSettingsHelper;
private WifiManager mWfm;
private static String mWifiConfigFile;
@Override
public void onCreate() {
if (DEBUG_BACKUP) Log.d(TAG, "onCreate() invoked");
mSettingsHelper = new SettingsHelper(this);
super.onCreate();
WifiManager mWfm = (WifiManager) getSystemService(Context.WIFI_SERVICE);
if (mWfm != null) mWifiConfigFile = mWfm.getConfigFile();
}
@Override
public void onBackup(ParcelFileDescriptor oldState, BackupDataOutput data,
ParcelFileDescriptor newState) throws IOException {
byte[] systemSettingsData = getSystemSettings();
byte[] secureSettingsData = getSecureSettings();
byte[] locale = mSettingsHelper.getLocaleData();
byte[] wifiSupplicantData = getWifiSupplicant(FILE_WIFI_SUPPLICANT);
byte[] wifiConfigData = getFileData(mWifiConfigFile);
long[] stateChecksums = readOldChecksums(oldState);
stateChecksums[STATE_SYSTEM] =
writeIfChanged(stateChecksums[STATE_SYSTEM], KEY_SYSTEM, systemSettingsData, data);
stateChecksums[STATE_SECURE] =
writeIfChanged(stateChecksums[STATE_SECURE], KEY_SECURE, secureSettingsData, data);
stateChecksums[STATE_LOCALE] =
writeIfChanged(stateChecksums[STATE_LOCALE], KEY_LOCALE, locale, data);
stateChecksums[STATE_WIFI_SUPPLICANT] =
writeIfChanged(stateChecksums[STATE_WIFI_SUPPLICANT], KEY_WIFI_SUPPLICANT,
wifiSupplicantData, data);
stateChecksums[STATE_WIFI_CONFIG] =
writeIfChanged(stateChecksums[STATE_WIFI_CONFIG], KEY_WIFI_CONFIG, wifiConfigData,
data);
writeNewChecksums(stateChecksums, newState);
}
@Override
public void onRestore(BackupDataInput data, int appVersionCode,
ParcelFileDescriptor newState) throws IOException {
while (data.readNextHeader()) {
final String key = data.getKey();
final int size = data.getDataSize();
if (KEY_SYSTEM.equals(key)) {
restoreSettings(data, Settings.System.CONTENT_URI);
mSettingsHelper.applyAudioSettings();
} else if (KEY_SECURE.equals(key)) {
restoreSettings(data, Settings.Secure.CONTENT_URI);
} else if (KEY_WIFI_SUPPLICANT.equals(key)) {
int retainedWifiState = enableWifi(false);
restoreWifiSupplicant(FILE_WIFI_SUPPLICANT, data);
FileUtils.setPermissions(FILE_WIFI_SUPPLICANT,
FileUtils.S_IRUSR | FileUtils.S_IWUSR |
FileUtils.S_IRGRP | FileUtils.S_IWGRP,
Process.myUid(), Process.WIFI_UID);
// retain the previous WIFI state.
enableWifi(retainedWifiState == WifiManager.WIFI_STATE_ENABLED ||
retainedWifiState == WifiManager.WIFI_STATE_ENABLING);
} else if (KEY_LOCALE.equals(key)) {
byte[] localeData = new byte[size];
data.readEntityData(localeData, 0, size);
mSettingsHelper.setLocaleData(localeData, size);
} else if (KEY_WIFI_CONFIG.equals(key)) {
restoreFileData(mWifiConfigFile, data);
} else {
data.skipEntityData();
}
}
}
@Override
public void onFullBackup(FullBackupDataOutput data) throws IOException {
byte[] systemSettingsData = getSystemSettings();
byte[] secureSettingsData = getSecureSettings();
byte[] locale = mSettingsHelper.getLocaleData();
byte[] wifiSupplicantData = getWifiSupplicant(FILE_WIFI_SUPPLICANT);
byte[] wifiConfigData = getFileData(mWifiConfigFile);
// Write the data to the staging file, then emit that as our tarfile
// representation of the backed-up settings.
String root = getFilesDir().getAbsolutePath();
File stage = new File(root, STAGE_FILE);
try {
FileOutputStream filestream = new FileOutputStream(stage);
BufferedOutputStream bufstream = new BufferedOutputStream(filestream);
DataOutputStream out = new DataOutputStream(bufstream);
if (DEBUG_BACKUP) Log.d(TAG, "Writing flattened data version " + FULL_BACKUP_VERSION);
out.writeInt(FULL_BACKUP_VERSION);
if (DEBUG_BACKUP) Log.d(TAG, systemSettingsData.length + " bytes of settings data");
out.writeInt(systemSettingsData.length);
out.write(systemSettingsData);
if (DEBUG_BACKUP) Log.d(TAG, secureSettingsData.length + " bytes of secure settings data");
out.writeInt(secureSettingsData.length);
out.write(secureSettingsData);
if (DEBUG_BACKUP) Log.d(TAG, locale.length + " bytes of locale data");
out.writeInt(locale.length);
out.write(locale);
if (DEBUG_BACKUP) Log.d(TAG, wifiSupplicantData.length + " bytes of wifi supplicant data");
out.writeInt(wifiSupplicantData.length);
out.write(wifiSupplicantData);
if (DEBUG_BACKUP) Log.d(TAG, wifiConfigData.length + " bytes of wifi config data");
out.writeInt(wifiConfigData.length);
out.write(wifiConfigData);
out.flush(); // also flushes downstream
// now we're set to emit the tar stream
fullBackupFile(stage, data);
} finally {
stage.delete();
}
}
@Override
public void onRestoreFile(ParcelFileDescriptor data, long size,
int type, String domain, String relpath, long mode, long mtime)
throws IOException {
if (DEBUG_BACKUP) Log.d(TAG, "onRestoreFile() invoked");
// Our data is actually a blob of flattened settings data identical to that
// produced during incremental backups. Just unpack and apply it all in
// turn.
FileInputStream instream = new FileInputStream(data.getFileDescriptor());
DataInputStream in = new DataInputStream(instream);
int version = in.readInt();
if (DEBUG_BACKUP) Log.d(TAG, "Flattened data version " + version);
if (version == FULL_BACKUP_VERSION) {
// system settings data first
int nBytes = in.readInt();
if (DEBUG_BACKUP) Log.d(TAG, nBytes + " bytes of settings data");
byte[] buffer = new byte[nBytes];
in.readFully(buffer, 0, nBytes);
restoreSettings(buffer, nBytes, Settings.System.CONTENT_URI);
// secure settings
nBytes = in.readInt();
if (DEBUG_BACKUP) Log.d(TAG, nBytes + " bytes of secure settings data");
if (nBytes > buffer.length) buffer = new byte[nBytes];
in.readFully(buffer, 0, nBytes);
restoreSettings(buffer, nBytes, Settings.Secure.CONTENT_URI);
// locale
nBytes = in.readInt();
if (DEBUG_BACKUP) Log.d(TAG, nBytes + " bytes of locale data");
if (nBytes > buffer.length) buffer = new byte[nBytes];
in.readFully(buffer, 0, nBytes);
mSettingsHelper.setLocaleData(buffer, nBytes);
// wifi supplicant
nBytes = in.readInt();
if (DEBUG_BACKUP) Log.d(TAG, nBytes + " bytes of wifi supplicant data");
if (nBytes > buffer.length) buffer = new byte[nBytes];
in.readFully(buffer, 0, nBytes);
int retainedWifiState = enableWifi(false);
restoreWifiSupplicant(FILE_WIFI_SUPPLICANT, buffer, nBytes);
FileUtils.setPermissions(FILE_WIFI_SUPPLICANT,
FileUtils.S_IRUSR | FileUtils.S_IWUSR |
FileUtils.S_IRGRP | FileUtils.S_IWGRP,
Process.myUid(), Process.WIFI_UID);
// retain the previous WIFI state.
enableWifi(retainedWifiState == WifiManager.WIFI_STATE_ENABLED ||
retainedWifiState == WifiManager.WIFI_STATE_ENABLING);
// wifi config
nBytes = in.readInt();
if (DEBUG_BACKUP) Log.d(TAG, nBytes + " bytes of wifi config data");
if (nBytes > buffer.length) buffer = new byte[nBytes];
in.readFully(buffer, 0, nBytes);
restoreFileData(mWifiConfigFile, buffer, nBytes);
if (DEBUG_BACKUP) Log.d(TAG, "Full restore complete.");
} else {
data.close();
throw new IOException("Invalid file schema");
}
}
private long[] readOldChecksums(ParcelFileDescriptor oldState) throws IOException {
long[] stateChecksums = new long[STATE_SIZE];
DataInputStream dataInput = new DataInputStream(
new FileInputStream(oldState.getFileDescriptor()));
try {
int stateVersion = dataInput.readInt();
if (stateVersion == STATE_VERSION_1) {
for (int i = 0; i < STATE_VERSION_1_SIZE; i++) {
stateChecksums[i] = dataInput.readLong();
}
} else if (stateVersion == STATE_VERSION) {
for (int i = 0; i < STATE_SIZE; i++) {
stateChecksums[i] = dataInput.readLong();
}
}
} catch (EOFException eof) {
// With the default 0 checksum we'll wind up forcing a backup of
// any unhandled data sets, which is appropriate.
}
dataInput.close();
return stateChecksums;
}
private void writeNewChecksums(long[] checksums, ParcelFileDescriptor newState)
throws IOException {
DataOutputStream dataOutput = new DataOutputStream(
new FileOutputStream(newState.getFileDescriptor()));
dataOutput.writeInt(STATE_VERSION);
for (int i = 0; i < STATE_SIZE; i++) {
dataOutput.writeLong(checksums[i]);
}
dataOutput.close();
}
private long writeIfChanged(long oldChecksum, String key, byte[] data,
BackupDataOutput output) {
CRC32 checkSummer = new CRC32();
checkSummer.update(data);
long newChecksum = checkSummer.getValue();
if (oldChecksum == newChecksum) {
return oldChecksum;
}
try {
output.writeEntityHeader(key, data.length);
output.writeEntityData(data, data.length);
} catch (IOException ioe) {
// Bail
}
return newChecksum;
}
private byte[] getSystemSettings() {
Cursor cursor = getContentResolver().query(Settings.System.CONTENT_URI, PROJECTION, null,
null, null);
try {
return extractRelevantValues(cursor, Settings.System.SETTINGS_TO_BACKUP);
} finally {
cursor.close();
}
}
private byte[] getSecureSettings() {
Cursor cursor = getContentResolver().query(Settings.Secure.CONTENT_URI, PROJECTION, null,
null, null);
try {
return extractRelevantValues(cursor, Settings.Secure.SETTINGS_TO_BACKUP);
} finally {
cursor.close();
}
}
private void restoreSettings(BackupDataInput data, Uri contentUri) {
byte[] settings = new byte[data.getDataSize()];
try {
data.readEntityData(settings, 0, settings.length);
} catch (IOException ioe) {
Log.e(TAG, "Couldn't read entity data");
return;
}
restoreSettings(settings, settings.length, contentUri);
}
private void restoreSettings(byte[] settings, int bytes, Uri contentUri) {
if (DEBUG) {
Log.i(TAG, "restoreSettings: " + contentUri);
}
// Figure out the white list.
String[] whitelist = null;
if (contentUri.equals(Settings.Secure.CONTENT_URI)) {
whitelist = Settings.Secure.SETTINGS_TO_BACKUP;
} else if (contentUri.equals(Settings.System.CONTENT_URI)) {
whitelist = Settings.System.SETTINGS_TO_BACKUP;
} else {
throw new IllegalArgumentException("Unknown URI: " + contentUri);
}
// Restore only the white list data.
int pos = 0;
Map<String, String> cachedEntries = new HashMap<String, String>();
ContentValues contentValues = new ContentValues(2);
SettingsHelper settingsHelper = mSettingsHelper;
final int whiteListSize = whitelist.length;
for (int i = 0; i < whiteListSize; i++) {
String key = whitelist[i];
String value = cachedEntries.remove(key);
// If the value not cached, let us look it up.
if (value == null) {
while (pos < bytes) {
int length = readInt(settings, pos);
pos += INTEGER_BYTE_COUNT;
String dataKey = length > 0 ? new String(settings, pos, length) : null;
pos += length;
length = readInt(settings, pos);
pos += INTEGER_BYTE_COUNT;
String dataValue = length > 0 ? new String(settings, pos, length) : null;
pos += length;
if (key.equals(dataKey)) {
value = dataValue;
break;
}
cachedEntries.put(dataKey, dataValue);
}
}
if (value == null) {
continue;
}
if (settingsHelper.restoreValue(key, value)) {
contentValues.clear();
contentValues.put(Settings.NameValueTable.NAME, key);
contentValues.put(Settings.NameValueTable.VALUE, value);
getContentResolver().insert(contentUri, contentValues);
}
if (DEBUG) {
Log.d(TAG, "Restored setting: " + key + "=" + value);
}
}
}
/**
* Given a cursor and a set of keys, extract the required keys and
* values and write them to a byte array.
*
* @param cursor A cursor with settings data.
* @param settings The settings to extract.
* @return The byte array of extracted values.
*/
private byte[] extractRelevantValues(Cursor cursor, String[] settings) {
final int settingsCount = settings.length;
byte[][] values = new byte[settingsCount * 2][]; // keys and values
if (!cursor.moveToFirst()) {
Log.e(TAG, "Couldn't read from the cursor");
return new byte[0];
}
// Obtain the relevant data in a temporary array.
int totalSize = 0;
int backedUpSettingIndex = 0;
Map<String, String> cachedEntries = new HashMap<String, String>();
for (int i = 0; i < settingsCount; i++) {
String key = settings[i];
String value = cachedEntries.remove(key);
// If the value not cached, let us look it up.
if (value == null) {
while (!cursor.isAfterLast()) {
String cursorKey = cursor.getString(COLUMN_NAME);
String cursorValue = cursor.getString(COLUMN_VALUE);
cursor.moveToNext();
if (key.equals(cursorKey)) {
value = cursorValue;
break;
}
cachedEntries.put(cursorKey, cursorValue);
}
}
if (value == null) {
continue;
}
// Write the key and value in the intermediary array.
byte[] keyBytes = key.getBytes();
totalSize += INTEGER_BYTE_COUNT + keyBytes.length;
values[backedUpSettingIndex * 2] = keyBytes;
byte[] valueBytes = value.getBytes();
totalSize += INTEGER_BYTE_COUNT + valueBytes.length;
values[backedUpSettingIndex * 2 + 1] = valueBytes;
backedUpSettingIndex++;
if (DEBUG) {
Log.d(TAG, "Backed up setting: " + key + "=" + value);
}
}
// Aggregate the result.
byte[] result = new byte[totalSize];
int pos = 0;
final int keyValuePairCount = backedUpSettingIndex * 2;
for (int i = 0; i < keyValuePairCount; i++) {
pos = writeInt(result, pos, values[i].length);
pos = writeBytes(result, pos, values[i]);
}
return result;
}
private byte[] getFileData(String filename) {
InputStream is = null;
try {
File file = new File(filename);
is = new FileInputStream(file);
//Will truncate read on a very long file,
//should not happen for a config file
byte[] bytes = new byte[(int)file.length()];
int offset = 0;
int numRead = 0;
while (offset < bytes.length
&& (numRead=is.read(bytes, offset, bytes.length-offset)) >= 0) {
offset += numRead;
}
//read failure
if (offset < bytes.length) {
Log.w(TAG, "Couldn't backup " + filename);
return EMPTY_DATA;
}
return bytes;
} catch (IOException ioe) {
Log.w(TAG, "Couldn't backup " + filename);
return EMPTY_DATA;
} finally {
if (is != null) {
try {
is.close();
} catch (IOException e) {
}
}
}
}
private void restoreFileData(String filename, BackupDataInput data) {
byte[] bytes = new byte[data.getDataSize()];
if (bytes.length <= 0) return;
try {
data.readEntityData(bytes, 0, data.getDataSize());
restoreFileData(filename, bytes, bytes.length);
} catch (IOException e) {
Log.w(TAG, "Unable to read file data for " + filename);
}
}
private void restoreFileData(String filename, byte[] bytes, int size) {
try {
File file = new File(filename);
if (file.exists()) file.delete();
OutputStream os = new BufferedOutputStream(new FileOutputStream(filename, true));
os.write(bytes, 0, size);
os.close();
} catch (IOException ioe) {
Log.w(TAG, "Couldn't restore " + filename);
}
}
private byte[] getWifiSupplicant(String filename) {
BufferedReader br = null;
try {
File file = new File(filename);
if (file.exists()) {
br = new BufferedReader(new FileReader(file));
StringBuffer relevantLines = new StringBuffer();
boolean started = false;
String line;
while ((line = br.readLine()) != null) {
if (!started && line.startsWith("network")) {
started = true;
}
if (started) {
relevantLines.append(line).append("\n");
}
}
if (relevantLines.length() > 0) {
return relevantLines.toString().getBytes();
} else {
return EMPTY_DATA;
}
} else {
return EMPTY_DATA;
}
} catch (IOException ioe) {
Log.w(TAG, "Couldn't backup " + filename);
return EMPTY_DATA;
} finally {
if (br != null) {
try {
br.close();
} catch (IOException e) {
}
}
}
}
private void restoreWifiSupplicant(String filename, BackupDataInput data) {
byte[] bytes = new byte[data.getDataSize()];
if (bytes.length <= 0) return;
try {
data.readEntityData(bytes, 0, data.getDataSize());
restoreWifiSupplicant(filename, bytes, bytes.length);
} catch (IOException e) {
Log.w(TAG, "Unable to read supplicant data");
}
}
private void restoreWifiSupplicant(String filename, byte[] bytes, int size) {
try {
File supplicantFile = new File(FILE_WIFI_SUPPLICANT);
if (supplicantFile.exists()) supplicantFile.delete();
copyWifiSupplicantTemplate();
OutputStream os = new BufferedOutputStream(new FileOutputStream(filename, true));
os.write("\n".getBytes());
os.write(bytes, 0, size);
os.close();
} catch (IOException ioe) {
Log.w(TAG, "Couldn't restore " + filename);
}
}
private void copyWifiSupplicantTemplate() {
try {
BufferedReader br = new BufferedReader(new FileReader(FILE_WIFI_SUPPLICANT_TEMPLATE));
BufferedWriter bw = new BufferedWriter(new FileWriter(FILE_WIFI_SUPPLICANT));
char[] temp = new char[1024];
int size;
while ((size = br.read(temp)) > 0) {
bw.write(temp, 0, size);
}
bw.close();
br.close();
} catch (IOException ioe) {
Log.w(TAG, "Couldn't copy wpa_supplicant file");
}
}
/**
* Write an int in BigEndian into the byte array.
* @param out byte array
* @param pos current pos in array
* @param value integer to write
* @return the index after adding the size of an int (4) in bytes.
*/
private int writeInt(byte[] out, int pos, int value) {
out[pos + 0] = (byte) ((value >> 24) & 0xFF);
out[pos + 1] = (byte) ((value >> 16) & 0xFF);
out[pos + 2] = (byte) ((value >> 8) & 0xFF);
out[pos + 3] = (byte) ((value >> 0) & 0xFF);
return pos + INTEGER_BYTE_COUNT;
}
private int writeBytes(byte[] out, int pos, byte[] value) {
System.arraycopy(value, 0, out, pos, value.length);
return pos + value.length;
}
private int readInt(byte[] in, int pos) {
int result =
((in[pos ] & 0xFF) << 24) |
((in[pos + 1] & 0xFF) << 16) |
((in[pos + 2] & 0xFF) << 8) |
((in[pos + 3] & 0xFF) << 0);
return result;
}
private int enableWifi(boolean enable) {
if (mWfm != null) {
int state = mWfm.getWifiState();
mWfm.setWifiEnabled(enable);
return state;
}
return WifiManager.WIFI_STATE_UNKNOWN;
}
}