service/java/com/android/server/wifi/SoftApBackupRestore.java - platform/packages/modules/Wifi - Git at Google

 /*
  * Copyright (C) 2019 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.server.wifi;

 import android.compat.Compatibility;
 import android.content.Context;
 import android.net.MacAddress;
 import android.net.wifi.SoftApConfiguration;
 import android.net.wifi.WifiConfiguration;
 import android.net.wifi.WifiMigration;
 import android.util.BackupUtils;
 import android.util.Log;
 import android.util.SparseIntArray;
 import android.util.Xml;

 import com.android.internal.util.FastXmlSerializer;
 import com.android.modules.utils.build.SdkLevel;
 import com.android.server.wifi.util.ApConfigUtil;
 import com.android.server.wifi.util.SettingsMigrationDataHolder;
 import com.android.server.wifi.util.XmlUtil;

 import org.xmlpull.v1.XmlPullParser;
 import org.xmlpull.v1.XmlPullParserException;
 import org.xmlpull.v1.XmlSerializer;

 import java.io.ByteArrayInputStream;
 import java.io.ByteArrayOutputStream;
 import java.io.DataInputStream;
 import java.io.DataOutputStream;
 import java.io.IOException;
 import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.Iterator;
 import java.util.List;

 /**
  * Class used to backup/restore data using the SettingsBackupAgent.
  * There are 2 symmetric API's exposed here:
  * 1. retrieveBackupDataFromSoftApConfiguration: Retrieve the configuration data to be backed up.
  * 2. retrieveSoftApConfigurationFromBackupData: Restore the configuration using the provided data.
  * The byte stream to be backed up is versioned to migrate the data easily across
  * revisions.
  */
 public class SoftApBackupRestore {
     private static final String TAG = "SoftApBackupRestore";

     /**
      * Current backup data version.
      */
     // Starting from SoftAp data backup version 9, framework support to back up configuration
     // in XML format. This allows to restore the SoftAp configuration when the user downgrades
     // the Android version. (From Any version >= 9 to version#9)
     private static final int SUPPORTED_SAP_BACKUP_XML_DATA_VERSION = 9;
     private static final int LAST_SAP_BACKUP_DATA_VERSION_IN_S = 8;
     private static final int LAST_SAP_BACKUP_DATA_VERSION_IN_R = 7;
     private static final String XML_TAG_DOCUMENT_HEADER = "SoftApBackupData";


     private static final int ETHER_ADDR_LEN = 6; // Byte array size of MacAddress

     private final Context mContext;
     private final SettingsMigrationDataHolder mSettingsMigrationDataHolder;

     public SoftApBackupRestore(Context context,
             SettingsMigrationDataHolder settingsMigrationDataHolder) {
         mContext = context;
         mSettingsMigrationDataHolder = settingsMigrationDataHolder;
     }

     /**
      * Retrieve a byte stream representing the data that needs to be backed up from the
      * provided softap configuration.
      *
      * @param config saved soft ap config that needs to be backed up.
      * @return Raw byte stream that needs to be backed up.
      */
     public byte[] retrieveBackupDataFromSoftApConfiguration(SoftApConfiguration config) {
         if (config == null) {
             Log.e(TAG, "Invalid configuration received");
             return new byte[0];
         }
         try {
             final ByteArrayOutputStream baos = new ByteArrayOutputStream();
             final DataOutputStream out = new DataOutputStream(baos);
             if (SdkLevel.isAtLeastT()) {
                 out.writeInt(SUPPORTED_SAP_BACKUP_XML_DATA_VERSION);
                 final XmlSerializer xmlOut = new FastXmlSerializer();
                 xmlOut.setOutput(baos, StandardCharsets.UTF_8.name());
                 XmlUtil.writeDocumentStart(xmlOut, XML_TAG_DOCUMENT_HEADER);

                 // Start writing the XML stream.
                 XmlUtil.SoftApConfigurationXmlUtil.writeSoftApConfigurationToXml(xmlOut, config);

                 XmlUtil.writeDocumentEnd(xmlOut, XML_TAG_DOCUMENT_HEADER);

             } else {
                 if (SdkLevel.isAtLeastS()) {
                     out.writeInt(LAST_SAP_BACKUP_DATA_VERSION_IN_S);
                 } else {
                     out.writeInt(LAST_SAP_BACKUP_DATA_VERSION_IN_R);
                 }
                 BackupUtils.writeString(out, config.getSsid());
                 out.writeInt(config.getBand());
                 out.writeInt(config.getChannel());
                 BackupUtils.writeString(out, config.getPassphrase());
                 out.writeInt(config.getSecurityType());
                 out.writeBoolean(config.isHiddenSsid());
                 out.writeInt(config.getMaxNumberOfClients());
                 out.writeLong(config.getShutdownTimeoutMillis());
                 out.writeBoolean(config.isClientControlByUserEnabled());
                 writeMacAddressList(out, config.getBlockedClientList());
                 writeMacAddressList(out, config.getAllowedClientList());
                 out.writeBoolean(config.isAutoShutdownEnabled());
                 if (SdkLevel.isAtLeastS()) {
                     out.writeBoolean(config.isBridgedModeOpportunisticShutdownEnabled());
                     out.writeInt(config.getMacRandomizationSetting());
                     SparseIntArray channels = config.getChannels();
                     int numOfChannels = channels.size();
                     out.writeInt(numOfChannels);
                     for (int i = 0; i < numOfChannels; i++) {
                         out.writeInt(channels.keyAt(i));
                         out.writeInt(channels.valueAt(i));
                     }
                     out.writeBoolean(config.isIeee80211axEnabled());
                 }
             }
             return baos.toByteArray();
         } catch (IOException | XmlPullParserException e) {
             Log.e(TAG, "Error retrieving the backup data from SoftApConfiguration: " +  config
                     + ", exception " + e);
         }
         return new byte[0];
     }

     /**
      * Parse out the configurations from the back up data.
      *
      * @param data raw byte stream representing the data.
      * @return Soft ap config retrieved from the backed up data.
      */
     public SoftApConfiguration retrieveSoftApConfigurationFromBackupData(byte[] data) {
         if (data == null || data.length == 0) {
             Log.e(TAG, "Invalid backup data received");
             return null;
         }
         SoftApConfiguration.Builder configBuilder = new SoftApConfiguration.Builder();
         try {
             DataInputStream in = new DataInputStream(new ByteArrayInputStream(data));
             int version = in.readInt();
             // Starting from T, frameworks support to downgrade restore configuration.
             if ((!SdkLevel.isAtLeastT() && version > LAST_SAP_BACKUP_DATA_VERSION_IN_S)
                     || version < 1) {
                 throw new BackupUtils.BadVersionException("Unknown Backup Serialization Version");
             }

             if (version == 1) return null; // Version 1 is a bad dataset.
             Log.i(TAG, "The backed-up version is " + version);

             if (version >= SUPPORTED_SAP_BACKUP_XML_DATA_VERSION) {
                 final XmlPullParser xmlIn = Xml.newPullParser();
                 ByteArrayInputStream inputStream = new ByteArrayInputStream(data);
                 // The first 4 bytes are designed to store version
                 inputStream.skip(Integer.BYTES);
                 xmlIn.setInput(inputStream, StandardCharsets.UTF_8.name());
                 XmlUtil.gotoDocumentStart(xmlIn, XML_TAG_DOCUMENT_HEADER);
                 int rootTagDepth = xmlIn.getDepth();
                 return XmlUtil.SoftApConfigurationXmlUtil
                         .parseFromXml(xmlIn, rootTagDepth, mSettingsMigrationDataHolder);
             }
             configBuilder.setSsid(BackupUtils.readString(in));

             int band;
             if (version < 4) {
                 band = ApConfigUtil.convertWifiConfigBandToSoftApConfigBand(in.readInt());
             } else {
                 band = in.readInt();
             }
             int channel = in.readInt();
             if (channel == 0) {
                 configBuilder.setBand(band);
             } else {
                 configBuilder.setChannel(channel, band);
             }
             String passphrase = BackupUtils.readString(in);
             int securityType = in.readInt();
             if (version < 4 && securityType == WifiConfiguration.KeyMgmt.WPA2_PSK) {
                 configBuilder.setPassphrase(passphrase, SoftApConfiguration.SECURITY_TYPE_WPA2_PSK);
             } else if (version >= 4 && securityType != SoftApConfiguration.SECURITY_TYPE_OPEN) {
                 configBuilder.setPassphrase(passphrase, securityType);
             }
             if (version >= 3) {
                 configBuilder.setHiddenSsid(in.readBoolean());
             }
             if (version >= 5) {
                 configBuilder.setMaxNumberOfClients(in.readInt());
                 long shutDownMillis;
                 if (version >= 7) {
                     shutDownMillis = in.readLong();
                 } else {
                     shutDownMillis = Long.valueOf(in.readInt());
                 }
                 if (shutDownMillis == 0 && Compatibility.isChangeEnabled(
                         SoftApConfiguration.REMOVE_ZERO_FOR_TIMEOUT_SETTING)) {
                     shutDownMillis = SoftApConfiguration.DEFAULT_TIMEOUT;
                 }
                 configBuilder.setShutdownTimeoutMillis(shutDownMillis);
                 configBuilder.setClientControlByUserEnabled(in.readBoolean());
                 int numberOfBlockedClient = in.readInt();
                 List<MacAddress> blockedList = new ArrayList<>(
                         macAddressListFromByteArray(in, numberOfBlockedClient));
                 int numberOfAllowedClient = in.readInt();
                 List<MacAddress> allowedList = new ArrayList<>(
                         macAddressListFromByteArray(in, numberOfAllowedClient));
                 configBuilder.setBlockedClientList(blockedList);
                 configBuilder.setAllowedClientList(allowedList);
             }
             if (version >= 6) {
                 configBuilder.setAutoShutdownEnabled(in.readBoolean());
             } else {
                 // Migrate data out of settings.
                 WifiMigration.SettingsMigrationData migrationData =
                         mSettingsMigrationDataHolder.retrieveData();
                 if (migrationData == null) {
                     Log.e(TAG, "No migration data present");
                 } else {
                     configBuilder.setAutoShutdownEnabled(migrationData.isSoftApTimeoutEnabled());
                 }
             }
             if (version >= 8 && SdkLevel.isAtLeastS()) {
                 configBuilder.setBridgedModeOpportunisticShutdownEnabled(in.readBoolean());
                 configBuilder.setMacRandomizationSetting(in.readInt());
                 int numOfChannels = in.readInt();
                 SparseIntArray channels = new SparseIntArray(numOfChannels);
                 for (int i = 0; i < numOfChannels; i++) {
                     channels.put(in.readInt(), in.readInt());
                 }
                 configBuilder.setChannels(channels);
                 configBuilder.setIeee80211axEnabled(in.readBoolean());
             }
             return configBuilder.build();
         } catch (IOException | BackupUtils.BadVersionException
                 | IllegalArgumentException | XmlPullParserException e) {
             Log.e(TAG, "Invalid backup data received, Exception: " + e);
         }
         return null;
     }

     private void writeMacAddressList(DataOutputStream out, List<MacAddress> macList)
             throws IOException {
         out.writeInt(macList.size());
         Iterator<MacAddress> iterator = macList.iterator();
         while (iterator.hasNext()) {
             byte[] mac = iterator.next().toByteArray();
             out.write(mac, 0, ETHER_ADDR_LEN);
         }
     }

     private List<MacAddress> macAddressListFromByteArray(DataInputStream in, int numberOfClients)
             throws IOException {
         List<MacAddress> macList = new ArrayList<>();
         for (int i = 0; i < numberOfClients; i++) {
             byte[] mac = new byte[ETHER_ADDR_LEN];
             in.read(mac, 0, ETHER_ADDR_LEN);
             macList.add(MacAddress.fromBytes(mac));
         }
         return macList;
     }
 }
	/*
	* Copyright (C) 2019 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.server.wifi;

	import android.compat.Compatibility;
	import android.content.Context;
	import android.net.MacAddress;
	import android.net.wifi.SoftApConfiguration;
	import android.net.wifi.WifiConfiguration;
	import android.net.wifi.WifiMigration;
	import android.util.BackupUtils;
	import android.util.Log;
	import android.util.SparseIntArray;
	import android.util.Xml;

	import com.android.internal.util.FastXmlSerializer;
	import com.android.modules.utils.build.SdkLevel;
	import com.android.server.wifi.util.ApConfigUtil;
	import com.android.server.wifi.util.SettingsMigrationDataHolder;
	import com.android.server.wifi.util.XmlUtil;

	import org.xmlpull.v1.XmlPullParser;
	import org.xmlpull.v1.XmlPullParserException;
	import org.xmlpull.v1.XmlSerializer;

	import java.io.ByteArrayInputStream;
	import java.io.ByteArrayOutputStream;
	import java.io.DataInputStream;
	import java.io.DataOutputStream;
	import java.io.IOException;
	import java.nio.charset.StandardCharsets;
	import java.util.ArrayList;
	import java.util.Iterator;
	import java.util.List;

	/**
	* Class used to backup/restore data using the SettingsBackupAgent.
	* There are 2 symmetric API's exposed here:
	* 1. retrieveBackupDataFromSoftApConfiguration: Retrieve the configuration data to be backed up.
	* 2. retrieveSoftApConfigurationFromBackupData: Restore the configuration using the provided data.
	* The byte stream to be backed up is versioned to migrate the data easily across
	* revisions.
	*/
	public class SoftApBackupRestore {
	private static final String TAG = "SoftApBackupRestore";

	/**
	* Current backup data version.
	*/
	// Starting from SoftAp data backup version 9, framework support to back up configuration
	// in XML format. This allows to restore the SoftAp configuration when the user downgrades
	// the Android version. (From Any version >= 9 to version#9)
	private static final int SUPPORTED_SAP_BACKUP_XML_DATA_VERSION = 9;
	private static final int LAST_SAP_BACKUP_DATA_VERSION_IN_S = 8;
	private static final int LAST_SAP_BACKUP_DATA_VERSION_IN_R = 7;
	private static final String XML_TAG_DOCUMENT_HEADER = "SoftApBackupData";


	private static final int ETHER_ADDR_LEN = 6; // Byte array size of MacAddress

	private final Context mContext;
	private final SettingsMigrationDataHolder mSettingsMigrationDataHolder;

	public SoftApBackupRestore(Context context,
	SettingsMigrationDataHolder settingsMigrationDataHolder) {
	mContext = context;
	mSettingsMigrationDataHolder = settingsMigrationDataHolder;
	}

	/**
	* Retrieve a byte stream representing the data that needs to be backed up from the
	* provided softap configuration.
	*
	* @param config saved soft ap config that needs to be backed up.
	* @return Raw byte stream that needs to be backed up.
	*/
	public byte[] retrieveBackupDataFromSoftApConfiguration(SoftApConfiguration config) {
	if (config == null) {
	Log.e(TAG, "Invalid configuration received");
	return new byte[0];
	}
	try {
	final ByteArrayOutputStream baos = new ByteArrayOutputStream();
	final DataOutputStream out = new DataOutputStream(baos);
	if (SdkLevel.isAtLeastT()) {
	out.writeInt(SUPPORTED_SAP_BACKUP_XML_DATA_VERSION);
	final XmlSerializer xmlOut = new FastXmlSerializer();
	xmlOut.setOutput(baos, StandardCharsets.UTF_8.name());
	XmlUtil.writeDocumentStart(xmlOut, XML_TAG_DOCUMENT_HEADER);

	// Start writing the XML stream.
	XmlUtil.SoftApConfigurationXmlUtil.writeSoftApConfigurationToXml(xmlOut, config);

	XmlUtil.writeDocumentEnd(xmlOut, XML_TAG_DOCUMENT_HEADER);

	} else {
	if (SdkLevel.isAtLeastS()) {
	out.writeInt(LAST_SAP_BACKUP_DATA_VERSION_IN_S);
	} else {
	out.writeInt(LAST_SAP_BACKUP_DATA_VERSION_IN_R);
	}
	BackupUtils.writeString(out, config.getSsid());
	out.writeInt(config.getBand());
	out.writeInt(config.getChannel());
	BackupUtils.writeString(out, config.getPassphrase());
	out.writeInt(config.getSecurityType());
	out.writeBoolean(config.isHiddenSsid());
	out.writeInt(config.getMaxNumberOfClients());
	out.writeLong(config.getShutdownTimeoutMillis());
	out.writeBoolean(config.isClientControlByUserEnabled());
	writeMacAddressList(out, config.getBlockedClientList());
	writeMacAddressList(out, config.getAllowedClientList());
	out.writeBoolean(config.isAutoShutdownEnabled());
	if (SdkLevel.isAtLeastS()) {
	out.writeBoolean(config.isBridgedModeOpportunisticShutdownEnabled());
	out.writeInt(config.getMacRandomizationSetting());
	SparseIntArray channels = config.getChannels();
	int numOfChannels = channels.size();
	out.writeInt(numOfChannels);
	for (int i = 0; i < numOfChannels; i++) {
	out.writeInt(channels.keyAt(i));
	out.writeInt(channels.valueAt(i));
	}
	out.writeBoolean(config.isIeee80211axEnabled());
	}
	}
	return baos.toByteArray();
	} catch (IOException \| XmlPullParserException e) {
	Log.e(TAG, "Error retrieving the backup data from SoftApConfiguration: " + config
	+ ", exception " + e);
	}
	return new byte[0];
	}

	/**
	* Parse out the configurations from the back up data.
	*
	* @param data raw byte stream representing the data.
	* @return Soft ap config retrieved from the backed up data.
	*/
	public SoftApConfiguration retrieveSoftApConfigurationFromBackupData(byte[] data) {
	if (data == null \|\| data.length == 0) {
	Log.e(TAG, "Invalid backup data received");
	return null;
	}
	SoftApConfiguration.Builder configBuilder = new SoftApConfiguration.Builder();
	try {
	DataInputStream in = new DataInputStream(new ByteArrayInputStream(data));
	int version = in.readInt();
	// Starting from T, frameworks support to downgrade restore configuration.
	if ((!SdkLevel.isAtLeastT() && version > LAST_SAP_BACKUP_DATA_VERSION_IN_S)
	\|\| version < 1) {
	throw new BackupUtils.BadVersionException("Unknown Backup Serialization Version");
	}

	if (version == 1) return null; // Version 1 is a bad dataset.
	Log.i(TAG, "The backed-up version is " + version);

	if (version >= SUPPORTED_SAP_BACKUP_XML_DATA_VERSION) {
	final XmlPullParser xmlIn = Xml.newPullParser();
	ByteArrayInputStream inputStream = new ByteArrayInputStream(data);
	// The first 4 bytes are designed to store version
	inputStream.skip(Integer.BYTES);
	xmlIn.setInput(inputStream, StandardCharsets.UTF_8.name());
	XmlUtil.gotoDocumentStart(xmlIn, XML_TAG_DOCUMENT_HEADER);
	int rootTagDepth = xmlIn.getDepth();
	return XmlUtil.SoftApConfigurationXmlUtil
	.parseFromXml(xmlIn, rootTagDepth, mSettingsMigrationDataHolder);
	}
	configBuilder.setSsid(BackupUtils.readString(in));

	int band;
	if (version < 4) {
	band = ApConfigUtil.convertWifiConfigBandToSoftApConfigBand(in.readInt());
	} else {
	band = in.readInt();
	}
	int channel = in.readInt();
	if (channel == 0) {
	configBuilder.setBand(band);
	} else {
	configBuilder.setChannel(channel, band);
	}
	String passphrase = BackupUtils.readString(in);
	int securityType = in.readInt();
	if (version < 4 && securityType == WifiConfiguration.KeyMgmt.WPA2_PSK) {
	configBuilder.setPassphrase(passphrase, SoftApConfiguration.SECURITY_TYPE_WPA2_PSK);
	} else if (version >= 4 && securityType != SoftApConfiguration.SECURITY_TYPE_OPEN) {
	configBuilder.setPassphrase(passphrase, securityType);
	}
	if (version >= 3) {
	configBuilder.setHiddenSsid(in.readBoolean());
	}
	if (version >= 5) {
	configBuilder.setMaxNumberOfClients(in.readInt());
	long shutDownMillis;
	if (version >= 7) {
	shutDownMillis = in.readLong();
	} else {
	shutDownMillis = Long.valueOf(in.readInt());
	}
	if (shutDownMillis == 0 && Compatibility.isChangeEnabled(
	SoftApConfiguration.REMOVE_ZERO_FOR_TIMEOUT_SETTING)) {
	shutDownMillis = SoftApConfiguration.DEFAULT_TIMEOUT;
	}
	configBuilder.setShutdownTimeoutMillis(shutDownMillis);
	configBuilder.setClientControlByUserEnabled(in.readBoolean());
	int numberOfBlockedClient = in.readInt();
	List<MacAddress> blockedList = new ArrayList<>(
	macAddressListFromByteArray(in, numberOfBlockedClient));
	int numberOfAllowedClient = in.readInt();
	List<MacAddress> allowedList = new ArrayList<>(
	macAddressListFromByteArray(in, numberOfAllowedClient));
	configBuilder.setBlockedClientList(blockedList);
	configBuilder.setAllowedClientList(allowedList);
	}
	if (version >= 6) {
	configBuilder.setAutoShutdownEnabled(in.readBoolean());
	} else {
	// Migrate data out of settings.
	WifiMigration.SettingsMigrationData migrationData =
	mSettingsMigrationDataHolder.retrieveData();
	if (migrationData == null) {
	Log.e(TAG, "No migration data present");
	} else {
	configBuilder.setAutoShutdownEnabled(migrationData.isSoftApTimeoutEnabled());
	}
	}
	if (version >= 8 && SdkLevel.isAtLeastS()) {
	configBuilder.setBridgedModeOpportunisticShutdownEnabled(in.readBoolean());
	configBuilder.setMacRandomizationSetting(in.readInt());
	int numOfChannels = in.readInt();
	SparseIntArray channels = new SparseIntArray(numOfChannels);
	for (int i = 0; i < numOfChannels; i++) {
	channels.put(in.readInt(), in.readInt());
	}
	configBuilder.setChannels(channels);
	configBuilder.setIeee80211axEnabled(in.readBoolean());
	}
	return configBuilder.build();
	} catch (IOException \| BackupUtils.BadVersionException
	\| IllegalArgumentException \| XmlPullParserException e) {
	Log.e(TAG, "Invalid backup data received, Exception: " + e);
	}
	return null;
	}

	private void writeMacAddressList(DataOutputStream out, List<MacAddress> macList)
	throws IOException {
	out.writeInt(macList.size());
	Iterator<MacAddress> iterator = macList.iterator();
	while (iterator.hasNext()) {
	byte[] mac = iterator.next().toByteArray();
	out.write(mac, 0, ETHER_ADDR_LEN);
	}
	}

	private List<MacAddress> macAddressListFromByteArray(DataInputStream in, int numberOfClients)
	throws IOException {
	List<MacAddress> macList = new ArrayList<>();
	for (int i = 0; i < numberOfClients; i++) {
	byte[] mac = new byte[ETHER_ADDR_LEN];
	in.read(mac, 0, ETHER_ADDR_LEN);
	macList.add(MacAddress.fromBytes(mac));
	}
	return macList;
	}
	}