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Android example source code file (WifiService.java)

This example Android source code file (WifiService.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Android by Example" TM.

Java - Android tags/keywords

android, ap, arraylist, dbg, failed, ibinder, intent, internet, multicaster, net, network, os, remoteexception, scanresult, string, util, wi-fi, wificonfiguration, wifilock, wifiservice

The WifiService.java Android example source code

/*
 * 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.server;

import static android.net.wifi.WifiManager.WIFI_STATE_DISABLED;
import static android.net.wifi.WifiManager.WIFI_STATE_DISABLING;
import static android.net.wifi.WifiManager.WIFI_STATE_ENABLED;
import static android.net.wifi.WifiManager.WIFI_STATE_ENABLING;
import static android.net.wifi.WifiManager.WIFI_STATE_UNKNOWN;

import static android.net.wifi.WifiManager.WIFI_AP_STATE_DISABLED;
import static android.net.wifi.WifiManager.WIFI_AP_STATE_DISABLING;
import static android.net.wifi.WifiManager.WIFI_AP_STATE_ENABLED;
import static android.net.wifi.WifiManager.WIFI_AP_STATE_ENABLING;
import static android.net.wifi.WifiManager.WIFI_AP_STATE_FAILED;

import android.app.AlarmManager;
import android.app.PendingIntent;
import android.bluetooth.BluetoothA2dp;
import android.bluetooth.BluetoothDevice;
import android.content.BroadcastReceiver;
import android.content.ContentResolver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.pm.PackageManager;
import android.net.wifi.IWifiManager;
import android.net.wifi.WifiInfo;
import android.net.wifi.WifiManager;
import android.net.wifi.WifiNative;
import android.net.wifi.WifiStateTracker;
import android.net.wifi.ScanResult;
import android.net.wifi.WifiConfiguration;
import android.net.wifi.SupplicantState;
import android.net.wifi.WifiConfiguration.KeyMgmt;
import android.net.ConnectivityManager;
import android.net.InterfaceConfiguration;
import android.net.NetworkStateTracker;
import android.net.DhcpInfo;
import android.net.NetworkUtils;
import android.os.Binder;
import android.os.Handler;
import android.os.HandlerThread;
import android.os.IBinder;
import android.os.INetworkManagementService;
import android.os.Looper;
import android.os.Message;
import android.os.PowerManager;
import android.os.Process;
import android.os.RemoteException;
import android.os.ServiceManager;
import android.provider.Settings;
import android.util.Slog;
import android.text.TextUtils;

import java.util.ArrayList;
import java.util.BitSet;
import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.regex.Pattern;
import java.io.FileDescriptor;
import java.io.PrintWriter;
import java.net.UnknownHostException;

import com.android.internal.app.IBatteryStats;
import android.app.backup.IBackupManager;
import com.android.server.am.BatteryStatsService;
import com.android.internal.R;

/**
 * WifiService handles remote WiFi operation requests by implementing
 * the IWifiManager interface. It also creates a WifiMonitor to listen
 * for Wifi-related events.
 *
 * @hide
 */
public class WifiService extends IWifiManager.Stub {
    private static final String TAG = "WifiService";
    private static final boolean DBG = false;
    private static final Pattern scanResultPattern = Pattern.compile("\t+");
    private final WifiStateTracker mWifiStateTracker;
    /* TODO: fetch a configurable interface */
    private static final String SOFTAP_IFACE = "wl0.1";

    private Context mContext;
    private int mWifiApState;

    private AlarmManager mAlarmManager;
    private PendingIntent mIdleIntent;
    private static final int IDLE_REQUEST = 0;
    private boolean mScreenOff;
    private boolean mDeviceIdle;
    private int mPluggedType;

    private enum DriverAction {DRIVER_UNLOAD, NO_DRIVER_UNLOAD};

    // true if the user enabled Wifi while in airplane mode
    private boolean mAirplaneModeOverwridden;

    private final LockList mLocks = new LockList();
    // some wifi lock statistics
    private int mFullLocksAcquired;
    private int mFullLocksReleased;
    private int mScanLocksAcquired;
    private int mScanLocksReleased;

    private final List<Multicaster> mMulticasters =
            new ArrayList<Multicaster>();
    private int mMulticastEnabled;
    private int mMulticastDisabled;

    private final IBatteryStats mBatteryStats;

    private INetworkManagementService nwService;
    ConnectivityManager mCm;
    private WifiWatchdogService mWifiWatchdogService = null;
    private String[] mWifiRegexs;

    /**
     * See {@link Settings.Secure#WIFI_IDLE_MS}. This is the default value if a
     * Settings.Secure value is not present. This timeout value is chosen as
     * the approximate point at which the battery drain caused by Wi-Fi
     * being enabled but not active exceeds the battery drain caused by
     * re-establishing a connection to the mobile data network.
     */
    private static final long DEFAULT_IDLE_MILLIS = 15 * 60 * 1000; /* 15 minutes */

    private static final String WAKELOCK_TAG = "WifiService";

    /**
     * The maximum amount of time to hold the wake lock after a disconnect
     * caused by stopping the driver. Establishing an EDGE connection has been
     * observed to take about 5 seconds under normal circumstances. This
     * provides a bit of extra margin.
     * <p>
     * See {@link android.provider.Settings.Secure#WIFI_MOBILE_DATA_TRANSITION_WAKELOCK_TIMEOUT_MS}.
     * This is the default value if a Settings.Secure value is not present.
     */
    private static final int DEFAULT_WAKELOCK_TIMEOUT = 8000;

    // Wake lock used by driver-stop operation
    private static PowerManager.WakeLock sDriverStopWakeLock;
    // Wake lock used by other operations
    private static PowerManager.WakeLock sWakeLock;

    private static final int MESSAGE_ENABLE_WIFI        = 0;
    private static final int MESSAGE_DISABLE_WIFI       = 1;
    private static final int MESSAGE_STOP_WIFI          = 2;
    private static final int MESSAGE_START_WIFI         = 3;
    private static final int MESSAGE_RELEASE_WAKELOCK   = 4;
    private static final int MESSAGE_UPDATE_STATE       = 5;
    private static final int MESSAGE_START_ACCESS_POINT = 6;
    private static final int MESSAGE_STOP_ACCESS_POINT  = 7;
    private static final int MESSAGE_SET_CHANNELS       = 8;


    private final  WifiHandler mWifiHandler;

    /*
     * Cache of scan results objects (size is somewhat arbitrary)
     */
    private static final int SCAN_RESULT_CACHE_SIZE = 80;
    private final LinkedHashMap<String, ScanResult> mScanResultCache;

    /*
     * Character buffer used to parse scan results (optimization)
     */
    private static final int SCAN_RESULT_BUFFER_SIZE = 512;
    private boolean mNeedReconfig;

    /*
     * Last UID that asked to enable WIFI.
     */
    private int mLastEnableUid = Process.myUid();

    /*
     * Last UID that asked to enable WIFI AP.
     */
    private int mLastApEnableUid = Process.myUid();


    /**
     * Number of allowed radio frequency channels in various regulatory domains.
     * This list is sufficient for 802.11b/g networks (2.4GHz range).
     */
    private static int[] sValidRegulatoryChannelCounts = new int[] {11, 13, 14};

    private static final String ACTION_DEVICE_IDLE =
            "com.android.server.WifiManager.action.DEVICE_IDLE";

    WifiService(Context context, WifiStateTracker tracker) {
        mContext = context;
        mWifiStateTracker = tracker;
        mWifiStateTracker.enableRssiPolling(true);
        mBatteryStats = BatteryStatsService.getService();

        IBinder b = ServiceManager.getService(Context.NETWORKMANAGEMENT_SERVICE);
        nwService = INetworkManagementService.Stub.asInterface(b);

        mScanResultCache = new LinkedHashMap<String, ScanResult>(
            SCAN_RESULT_CACHE_SIZE, 0.75f, true) {
                /*
                 * Limit the cache size by SCAN_RESULT_CACHE_SIZE
                 * elements
                 */
                public boolean removeEldestEntry(Map.Entry eldest) {
                    return SCAN_RESULT_CACHE_SIZE < this.size();
                }
            };

        HandlerThread wifiThread = new HandlerThread("WifiService");
        wifiThread.start();
        mWifiHandler = new WifiHandler(wifiThread.getLooper());

        mWifiStateTracker.setWifiState(WIFI_STATE_DISABLED);
        mWifiApState = WIFI_AP_STATE_DISABLED;

        mAlarmManager = (AlarmManager)mContext.getSystemService(Context.ALARM_SERVICE);
        Intent idleIntent = new Intent(ACTION_DEVICE_IDLE, null);
        mIdleIntent = PendingIntent.getBroadcast(mContext, IDLE_REQUEST, idleIntent, 0);

        PowerManager powerManager = (PowerManager)mContext.getSystemService(Context.POWER_SERVICE);
        sWakeLock = powerManager.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, WAKELOCK_TAG);
        sDriverStopWakeLock = powerManager.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, WAKELOCK_TAG);

        mContext.registerReceiver(
                new BroadcastReceiver() {
                    @Override
                    public void onReceive(Context context, Intent intent) {
                        // clear our flag indicating the user has overwridden airplane mode
                        mAirplaneModeOverwridden = false;
                        // on airplane disable, restore Wifi if the saved state indicates so
                        if (!isAirplaneModeOn() && testAndClearWifiSavedState()) {
                            persistWifiEnabled(true);
                        }
                        updateWifiState();
                    }
                },
                new IntentFilter(Intent.ACTION_AIRPLANE_MODE_CHANGED));

        mContext.registerReceiver(
            new BroadcastReceiver() {
                @Override
                public void onReceive(Context context, Intent intent) {

                  ArrayList<String> available = intent.getStringArrayListExtra(
                          ConnectivityManager.EXTRA_AVAILABLE_TETHER);
                  ArrayList<String> active = intent.getStringArrayListExtra(
                          ConnectivityManager.EXTRA_ACTIVE_TETHER);
                  updateTetherState(available, active);

                }
            },new IntentFilter(ConnectivityManager.ACTION_TETHER_STATE_CHANGED));
    }

    /**
     * Check if Wi-Fi needs to be enabled and start
     * if needed
     *
     * This function is used only at boot time
     */
    public void startWifi() {
        /* Start if Wi-Fi is enabled or the saved state indicates Wi-Fi was on */
        boolean wifiEnabled = !isAirplaneModeOn()
                && (getPersistedWifiEnabled() || testAndClearWifiSavedState());
        Slog.i(TAG, "WifiService starting up with Wi-Fi " +
                (wifiEnabled ? "enabled" : "disabled"));
        setWifiEnabled(wifiEnabled);
    }

    private void updateTetherState(ArrayList<String> available, ArrayList tethered) {

        boolean wifiTethered = false;
        boolean wifiAvailable = false;

        IBinder b = ServiceManager.getService(Context.NETWORKMANAGEMENT_SERVICE);
        INetworkManagementService service = INetworkManagementService.Stub.asInterface(b);

        mCm = (ConnectivityManager)mContext.getSystemService(Context.CONNECTIVITY_SERVICE);
        mWifiRegexs = mCm.getTetherableWifiRegexs();

        for (String intf : available) {
            for (String regex : mWifiRegexs) {
                if (intf.matches(regex)) {

                    InterfaceConfiguration ifcg = null;
                    try {
                        ifcg = service.getInterfaceConfig(intf);
                        if (ifcg != null) {
                            /* IP/netmask: 192.168.43.1/255.255.255.0 */
                            ifcg.ipAddr = (192 << 24) + (168 << 16) + (43 << 8) + 1;
                            ifcg.netmask = (255 << 24) + (255 << 16) + (255 << 8) + 0;
                            ifcg.interfaceFlags = "up";

                            service.setInterfaceConfig(intf, ifcg);
                        }
                    } catch (Exception e) {
                        Slog.e(TAG, "Error configuring interface " + intf + ", :" + e);
                        try {
                            nwService.stopAccessPoint();
                        } catch (Exception ee) {
                            Slog.e(TAG, "Could not stop AP, :" + ee);
                        }
                        setWifiApEnabledState(WIFI_AP_STATE_FAILED, 0, DriverAction.DRIVER_UNLOAD);
                        return;
                    }

                    if(mCm.tether(intf) != ConnectivityManager.TETHER_ERROR_NO_ERROR) {
                        Slog.e(TAG, "Error tethering "+intf);
                    }
                    break;
                }
            }
        }
    }

    private boolean testAndClearWifiSavedState() {
        final ContentResolver cr = mContext.getContentResolver();
        int wifiSavedState = 0;
        try {
            wifiSavedState = Settings.Secure.getInt(cr, Settings.Secure.WIFI_SAVED_STATE);
            if(wifiSavedState == 1)
                Settings.Secure.putInt(cr, Settings.Secure.WIFI_SAVED_STATE, 0);
        } catch (Settings.SettingNotFoundException e) {
            ;
        }
        return (wifiSavedState == 1);
    }

    private boolean getPersistedWifiEnabled() {
        final ContentResolver cr = mContext.getContentResolver();
        try {
            return Settings.Secure.getInt(cr, Settings.Secure.WIFI_ON) == 1;
        } catch (Settings.SettingNotFoundException e) {
            Settings.Secure.putInt(cr, Settings.Secure.WIFI_ON, 0);
            return false;
        }
    }

    private void persistWifiEnabled(boolean enabled) {
        final ContentResolver cr = mContext.getContentResolver();
        Settings.Secure.putInt(cr, Settings.Secure.WIFI_ON, enabled ? 1 : 0);
    }

    NetworkStateTracker getNetworkStateTracker() {
        return mWifiStateTracker;
    }

    /**
     * see {@link android.net.wifi.WifiManager#pingSupplicant()}
     * @return {@code true} if the operation succeeds
     */
    public boolean pingSupplicant() {
        enforceChangePermission();

        return mWifiStateTracker.ping();
    }

    /**
     * see {@link android.net.wifi.WifiManager#startScan()}
     * @return {@code true} if the operation succeeds
     */
    public boolean startScan(boolean forceActive) {
        enforceChangePermission();

        switch (mWifiStateTracker.getSupplicantState()) {
            case DISCONNECTED:
            case INACTIVE:
            case SCANNING:
            case DORMANT:
                break;
            default:
                mWifiStateTracker.setScanResultHandling(
                        WifiStateTracker.SUPPL_SCAN_HANDLING_LIST_ONLY);
                break;
        }
        return mWifiStateTracker.scan(forceActive);
    }

    /**
     * see {@link android.net.wifi.WifiManager#setWifiEnabled(boolean)}
     * @param enable {@code true} to enable, {@code false} to disable.
     * @return {@code true} if the enable/disable operation was
     *         started or is already in the queue.
     */
    public boolean setWifiEnabled(boolean enable) {
        enforceChangePermission();
        if (mWifiHandler == null) return false;

        synchronized (mWifiHandler) {
            // caller may not have WAKE_LOCK permission - it's not required here
            long ident = Binder.clearCallingIdentity();
            sWakeLock.acquire();
            Binder.restoreCallingIdentity(ident);

            mLastEnableUid = Binder.getCallingUid();
            // set a flag if the user is enabling Wifi while in airplane mode
            mAirplaneModeOverwridden = (enable && isAirplaneModeOn() && isAirplaneToggleable());
            sendEnableMessage(enable, true, Binder.getCallingUid());
        }

        return true;
    }

    /**
     * Enables/disables Wi-Fi synchronously.
     * @param enable {@code true} to turn Wi-Fi on, {@code false} to turn it off.
     * @param persist {@code true} if the setting should be persisted.
     * @param uid The UID of the process making the request.
     * @return {@code true} if the operation succeeds (or if the existing state
     *         is the same as the requested state)
     */
    private boolean setWifiEnabledBlocking(boolean enable, boolean persist, int uid) {
        final int eventualWifiState = enable ? WIFI_STATE_ENABLED : WIFI_STATE_DISABLED;
        final int wifiState = mWifiStateTracker.getWifiState();

        if (wifiState == eventualWifiState) {
            return true;
        }
        if (enable && isAirplaneModeOn() && !mAirplaneModeOverwridden) {
            return false;
        }

        /**
         * Multiple calls to unregisterReceiver() cause exception and a system crash.
         * This can happen if a supplicant is lost (or firmware crash occurs) and user indicates
         * disable wifi at the same time.
         * Avoid doing a disable when the current Wifi state is UNKNOWN
         * TODO: Handle driver load fail and supplicant lost as seperate states
         */
        if ((wifiState == WIFI_STATE_UNKNOWN) && !enable) {
            return false;
        }

        /**
         * Fail Wifi if AP is enabled
         * TODO: Deprecate WIFI_STATE_UNKNOWN and rename it
         * WIFI_STATE_FAILED
         */
        if ((mWifiApState == WIFI_AP_STATE_ENABLED) && enable) {
            setWifiEnabledState(WIFI_STATE_UNKNOWN, uid);
            return false;
        }

        setWifiEnabledState(enable ? WIFI_STATE_ENABLING : WIFI_STATE_DISABLING, uid);

        if (enable) {
            if (!mWifiStateTracker.loadDriver()) {
                Slog.e(TAG, "Failed to load Wi-Fi driver.");
                setWifiEnabledState(WIFI_STATE_UNKNOWN, uid);
                return false;
            }
            if (!mWifiStateTracker.startSupplicant()) {
                mWifiStateTracker.unloadDriver();
                Slog.e(TAG, "Failed to start supplicant daemon.");
                setWifiEnabledState(WIFI_STATE_UNKNOWN, uid);
                return false;
            }

            registerForBroadcasts();
            mWifiStateTracker.startEventLoop();

        } else {

            mContext.unregisterReceiver(mReceiver);
           // Remove notification (it will no-op if it isn't visible)
            mWifiStateTracker.setNotificationVisible(false, 0, false, 0);

            boolean failedToStopSupplicantOrUnloadDriver = false;

            if (!mWifiStateTracker.stopSupplicant()) {
                Slog.e(TAG, "Failed to stop supplicant daemon.");
                setWifiEnabledState(WIFI_STATE_UNKNOWN, uid);
                failedToStopSupplicantOrUnloadDriver = true;
            }

            /**
             * Reset connections and disable interface
             * before we unload the driver
             */
            mWifiStateTracker.resetConnections(true);

            if (!mWifiStateTracker.unloadDriver()) {
                Slog.e(TAG, "Failed to unload Wi-Fi driver.");
                if (!failedToStopSupplicantOrUnloadDriver) {
                    setWifiEnabledState(WIFI_STATE_UNKNOWN, uid);
                    failedToStopSupplicantOrUnloadDriver = true;
                }
            }

            if (failedToStopSupplicantOrUnloadDriver) {
                return false;
            }
        }

        // Success!

        if (persist) {
            persistWifiEnabled(enable);
        }
        setWifiEnabledState(eventualWifiState, uid);
        return true;
    }

    private void setWifiEnabledState(int wifiState, int uid) {
        final int previousWifiState = mWifiStateTracker.getWifiState();

        long ident = Binder.clearCallingIdentity();
        try {
            if (wifiState == WIFI_STATE_ENABLED) {
                mBatteryStats.noteWifiOn(uid);
            } else if (wifiState == WIFI_STATE_DISABLED) {
                mBatteryStats.noteWifiOff(uid);
            }
        } catch (RemoteException e) {
        } finally {
            Binder.restoreCallingIdentity(ident);
        }

        // Update state
        mWifiStateTracker.setWifiState(wifiState);

        // Broadcast
        final Intent intent = new Intent(WifiManager.WIFI_STATE_CHANGED_ACTION);
        intent.addFlags(Intent.FLAG_RECEIVER_REGISTERED_ONLY_BEFORE_BOOT);
        intent.putExtra(WifiManager.EXTRA_WIFI_STATE, wifiState);
        intent.putExtra(WifiManager.EXTRA_PREVIOUS_WIFI_STATE, previousWifiState);
        mContext.sendStickyBroadcast(intent);
    }

    private void enforceAccessPermission() {
        mContext.enforceCallingOrSelfPermission(android.Manifest.permission.ACCESS_WIFI_STATE,
                                                "WifiService");
    }

    private void enforceChangePermission() {
        mContext.enforceCallingOrSelfPermission(android.Manifest.permission.CHANGE_WIFI_STATE,
                                                "WifiService");

    }

    private void enforceMulticastChangePermission() {
        mContext.enforceCallingOrSelfPermission(
                android.Manifest.permission.CHANGE_WIFI_MULTICAST_STATE,
                "WifiService");
    }

    /**
     * see {@link WifiManager#getWifiState()}
     * @return One of {@link WifiManager#WIFI_STATE_DISABLED},
     *         {@link WifiManager#WIFI_STATE_DISABLING},
     *         {@link WifiManager#WIFI_STATE_ENABLED},
     *         {@link WifiManager#WIFI_STATE_ENABLING},
     *         {@link WifiManager#WIFI_STATE_UNKNOWN}
     */
    public int getWifiEnabledState() {
        enforceAccessPermission();
        return mWifiStateTracker.getWifiState();
    }

    /**
     * see {@link android.net.wifi.WifiManager#disconnect()}
     * @return {@code true} if the operation succeeds
     */
    public boolean disconnect() {
        enforceChangePermission();

        return mWifiStateTracker.disconnect();
    }

    /**
     * see {@link android.net.wifi.WifiManager#reconnect()}
     * @return {@code true} if the operation succeeds
     */
    public boolean reconnect() {
        enforceChangePermission();

        return mWifiStateTracker.reconnectCommand();
    }

    /**
     * see {@link android.net.wifi.WifiManager#reassociate()}
     * @return {@code true} if the operation succeeds
     */
    public boolean reassociate() {
        enforceChangePermission();

        return mWifiStateTracker.reassociate();
    }

    /**
     * see {@link android.net.wifi.WifiManager#setWifiApEnabled(WifiConfiguration, boolean)}
     * @param wifiConfig SSID, security and channel details as
     *        part of WifiConfiguration
     * @param enabled, true to enable and false to disable
     * @return {@code true} if the start operation was
     *         started or is already in the queue.
     */
    public boolean setWifiApEnabled(WifiConfiguration wifiConfig, boolean enabled) {
        enforceChangePermission();
        if (mWifiHandler == null) return false;

        synchronized (mWifiHandler) {

            long ident = Binder.clearCallingIdentity();
            sWakeLock.acquire();
            Binder.restoreCallingIdentity(ident);

            mLastApEnableUid = Binder.getCallingUid();
            sendAccessPointMessage(enabled, wifiConfig, Binder.getCallingUid());
        }

        return true;
    }

    public WifiConfiguration getWifiApConfiguration() {
        final ContentResolver cr = mContext.getContentResolver();
        WifiConfiguration wifiConfig = new WifiConfiguration();
        int authType;
        try {
            wifiConfig.SSID = Settings.Secure.getString(cr, Settings.Secure.WIFI_AP_SSID);
            if (wifiConfig.SSID == null)
                return null;
            authType = Settings.Secure.getInt(cr, Settings.Secure.WIFI_AP_SECURITY);
            wifiConfig.allowedKeyManagement.set(authType);
            wifiConfig.preSharedKey = Settings.Secure.getString(cr, Settings.Secure.WIFI_AP_PASSWD);
            return wifiConfig;
        } catch (Settings.SettingNotFoundException e) {
            Slog.e(TAG,"AP settings not found, returning");
            return null;
        }
    }

    private void persistApConfiguration(WifiConfiguration wifiConfig) {
        final ContentResolver cr = mContext.getContentResolver();
        boolean isWpa;
        if (wifiConfig == null)
            return;
        Settings.Secure.putString(cr, Settings.Secure.WIFI_AP_SSID, wifiConfig.SSID);
        isWpa = wifiConfig.allowedKeyManagement.get(KeyMgmt.WPA_PSK);
        Settings.Secure.putInt(cr,
                               Settings.Secure.WIFI_AP_SECURITY,
                               isWpa ? KeyMgmt.WPA_PSK : KeyMgmt.NONE);
        if (isWpa)
            Settings.Secure.putString(cr, Settings.Secure.WIFI_AP_PASSWD, wifiConfig.preSharedKey);
    }

    /**
     * Enables/disables Wi-Fi AP synchronously. The driver is loaded
     * and soft access point configured as a single operation.
     * @param enable {@code true} to turn Wi-Fi on, {@code false} to turn it off.
     * @param uid The UID of the process making the request.
     * @param wifiConfig The WifiConfiguration for AP
     * @return {@code true} if the operation succeeds (or if the existing state
     *         is the same as the requested state)
     */
    private boolean setWifiApEnabledBlocking(boolean enable,
                                int uid, WifiConfiguration wifiConfig) {
        final int eventualWifiApState = enable ? WIFI_AP_STATE_ENABLED : WIFI_AP_STATE_DISABLED;

        if (mWifiApState == eventualWifiApState) {
            /* Configuration changed on a running access point */
            if(enable && (wifiConfig != null)) {
                try {
                    persistApConfiguration(wifiConfig);
                    nwService.setAccessPoint(wifiConfig, mWifiStateTracker.getInterfaceName(),
                                             SOFTAP_IFACE);
                    return true;
                } catch(Exception e) {
                    Slog.e(TAG, "Exception in nwService during AP restart");
                    try {
                        nwService.stopAccessPoint();
                    } catch (Exception ee) {
                        Slog.e(TAG, "Could not stop AP, :" + ee);
                    }
                    setWifiApEnabledState(WIFI_AP_STATE_FAILED, uid, DriverAction.DRIVER_UNLOAD);
                    return false;
                }
            } else {
                return true;
            }
        }

        /**
         * Fail AP if Wifi is enabled
         */
        if ((mWifiStateTracker.getWifiState() == WIFI_STATE_ENABLED) && enable) {
            setWifiApEnabledState(WIFI_AP_STATE_FAILED, uid, DriverAction.NO_DRIVER_UNLOAD);
            return false;
        }

        setWifiApEnabledState(enable ? WIFI_AP_STATE_ENABLING :
                                       WIFI_AP_STATE_DISABLING, uid, DriverAction.NO_DRIVER_UNLOAD);

        if (enable) {

            /* Use default config if there is no existing config */
            if (wifiConfig == null && ((wifiConfig = getWifiApConfiguration()) == null)) {
                wifiConfig = new WifiConfiguration();
                wifiConfig.SSID = mContext.getString(R.string.wifi_tether_configure_ssid_default);
                wifiConfig.allowedKeyManagement.set(KeyMgmt.NONE);
            }
            persistApConfiguration(wifiConfig);

            if (!mWifiStateTracker.loadDriver()) {
                Slog.e(TAG, "Failed to load Wi-Fi driver for AP mode");
                setWifiApEnabledState(WIFI_AP_STATE_FAILED, uid, DriverAction.NO_DRIVER_UNLOAD);
                return false;
            }

            try {
                nwService.startAccessPoint(wifiConfig, mWifiStateTracker.getInterfaceName(),
                                           SOFTAP_IFACE);
            } catch(Exception e) {
                Slog.e(TAG, "Exception in startAccessPoint()");
                setWifiApEnabledState(WIFI_AP_STATE_FAILED, uid, DriverAction.DRIVER_UNLOAD);
                return false;
            }

        } else {

            try {
                nwService.stopAccessPoint();
            } catch(Exception e) {
                Slog.e(TAG, "Exception in stopAccessPoint()");
                setWifiApEnabledState(WIFI_AP_STATE_FAILED, uid, DriverAction.DRIVER_UNLOAD);
                return false;
            }

            if (!mWifiStateTracker.unloadDriver()) {
                Slog.e(TAG, "Failed to unload Wi-Fi driver for AP mode");
                setWifiApEnabledState(WIFI_AP_STATE_FAILED, uid, DriverAction.NO_DRIVER_UNLOAD);
                return false;
            }
        }

        setWifiApEnabledState(eventualWifiApState, uid, DriverAction.NO_DRIVER_UNLOAD);
        return true;
    }

    /**
     * see {@link WifiManager#getWifiApState()}
     * @return One of {@link WifiManager#WIFI_AP_STATE_DISABLED},
     *         {@link WifiManager#WIFI_AP_STATE_DISABLING},
     *         {@link WifiManager#WIFI_AP_STATE_ENABLED},
     *         {@link WifiManager#WIFI_AP_STATE_ENABLING},
     *         {@link WifiManager#WIFI_AP_STATE_FAILED}
     */
    public int getWifiApEnabledState() {
        enforceAccessPermission();
        return mWifiApState;
    }

    private void setWifiApEnabledState(int wifiAPState, int uid, DriverAction flag) {
        final int previousWifiApState = mWifiApState;

        /**
         * Unload the driver if going to a failed state
         */
        if ((mWifiApState == WIFI_AP_STATE_FAILED) && (flag == DriverAction.DRIVER_UNLOAD)) {
            mWifiStateTracker.unloadDriver();
        }

        long ident = Binder.clearCallingIdentity();
        try {
            if (wifiAPState == WIFI_AP_STATE_ENABLED) {
                mBatteryStats.noteWifiOn(uid);
            } else if (wifiAPState == WIFI_AP_STATE_DISABLED) {
                mBatteryStats.noteWifiOff(uid);
            }
        } catch (RemoteException e) {
        } finally {
            Binder.restoreCallingIdentity(ident);
        }

        // Update state
        mWifiApState = wifiAPState;

        // Broadcast
        final Intent intent = new Intent(WifiManager.WIFI_AP_STATE_CHANGED_ACTION);
        intent.addFlags(Intent.FLAG_RECEIVER_REGISTERED_ONLY_BEFORE_BOOT);
        intent.putExtra(WifiManager.EXTRA_WIFI_AP_STATE, wifiAPState);
        intent.putExtra(WifiManager.EXTRA_PREVIOUS_WIFI_AP_STATE, previousWifiApState);
        mContext.sendStickyBroadcast(intent);
    }

    /**
     * see {@link android.net.wifi.WifiManager#getConfiguredNetworks()}
     * @return the list of configured networks
     */
    public List<WifiConfiguration> getConfiguredNetworks() {
        enforceAccessPermission();
        String listStr;

        /*
         * We don't cache the list, because we want to allow
         * for the possibility that the configuration file
         * has been modified through some external means,
         * such as the wpa_cli command line program.
         */
        listStr = mWifiStateTracker.listNetworks();

        List<WifiConfiguration> networks =
            new ArrayList<WifiConfiguration>();
        if (listStr == null)
            return networks;

        String[] lines = listStr.split("\n");
        // Skip the first line, which is a header
       for (int i = 1; i < lines.length; i++) {
           String[] result = lines[i].split("\t");
           // network-id | ssid | bssid | flags
           WifiConfiguration config = new WifiConfiguration();
           try {
               config.networkId = Integer.parseInt(result[0]);
           } catch(NumberFormatException e) {
               continue;
           }
           if (result.length > 3) {
               if (result[3].indexOf("[CURRENT]") != -1)
                   config.status = WifiConfiguration.Status.CURRENT;
               else if (result[3].indexOf("[DISABLED]") != -1)
                   config.status = WifiConfiguration.Status.DISABLED;
               else
                   config.status = WifiConfiguration.Status.ENABLED;
           } else {
               config.status = WifiConfiguration.Status.ENABLED;
           }
           readNetworkVariables(config);
           networks.add(config);
       }

        return networks;
    }

    /**
     * Read the variables from the supplicant daemon that are needed to
     * fill in the WifiConfiguration object.
     * <p/>
     * The caller must hold the synchronization monitor.
     * @param config the {@link WifiConfiguration} object to be filled in.
     */
    private void readNetworkVariables(WifiConfiguration config) {

        int netId = config.networkId;
        if (netId < 0)
            return;

        /*
         * TODO: maybe should have a native method that takes an array of
         * variable names and returns an array of values. But we'd still
         * be doing a round trip to the supplicant daemon for each variable.
         */
        String value;

        value = mWifiStateTracker.getNetworkVariable(netId, WifiConfiguration.ssidVarName);
        if (!TextUtils.isEmpty(value)) {
            config.SSID = value;
        } else {
            config.SSID = null;
        }

        value = mWifiStateTracker.getNetworkVariable(netId, WifiConfiguration.bssidVarName);
        if (!TextUtils.isEmpty(value)) {
            config.BSSID = value;
        } else {
            config.BSSID = null;
        }

        value = mWifiStateTracker.getNetworkVariable(netId, WifiConfiguration.priorityVarName);
        config.priority = -1;
        if (!TextUtils.isEmpty(value)) {
            try {
                config.priority = Integer.parseInt(value);
            } catch (NumberFormatException ignore) {
            }
        }

        value = mWifiStateTracker.getNetworkVariable(netId, WifiConfiguration.hiddenSSIDVarName);
        config.hiddenSSID = false;
        if (!TextUtils.isEmpty(value)) {
            try {
                config.hiddenSSID = Integer.parseInt(value) != 0;
            } catch (NumberFormatException ignore) {
            }
        }

        value = mWifiStateTracker.getNetworkVariable(netId, WifiConfiguration.wepTxKeyIdxVarName);
        config.wepTxKeyIndex = -1;
        if (!TextUtils.isEmpty(value)) {
            try {
                config.wepTxKeyIndex = Integer.parseInt(value);
            } catch (NumberFormatException ignore) {
            }
        }

        /*
         * Get up to 4 WEP keys. Note that the actual keys are not passed back,
         * just a "*" if the key is set, or the null string otherwise.
         */
        for (int i = 0; i < 4; i++) {
            value = mWifiStateTracker.getNetworkVariable(netId, WifiConfiguration.wepKeyVarNames[i]);
            if (!TextUtils.isEmpty(value)) {
                config.wepKeys[i] = value;
            } else {
                config.wepKeys[i] = null;
            }
        }

        /*
         * Get the private shared key. Note that the actual keys are not passed back,
         * just a "*" if the key is set, or the null string otherwise.
         */
        value = mWifiStateTracker.getNetworkVariable(netId, WifiConfiguration.pskVarName);
        if (!TextUtils.isEmpty(value)) {
            config.preSharedKey = value;
        } else {
            config.preSharedKey = null;
        }

        value = mWifiStateTracker.getNetworkVariable(config.networkId,
                WifiConfiguration.Protocol.varName);
        if (!TextUtils.isEmpty(value)) {
            String vals[] = value.split(" ");
            for (String val : vals) {
                int index =
                    lookupString(val, WifiConfiguration.Protocol.strings);
                if (0 <= index) {
                    config.allowedProtocols.set(index);
                }
            }
        }

        value = mWifiStateTracker.getNetworkVariable(config.networkId,
                WifiConfiguration.KeyMgmt.varName);
        if (!TextUtils.isEmpty(value)) {
            String vals[] = value.split(" ");
            for (String val : vals) {
                int index =
                    lookupString(val, WifiConfiguration.KeyMgmt.strings);
                if (0 <= index) {
                    config.allowedKeyManagement.set(index);
                }
            }
        }

        value = mWifiStateTracker.getNetworkVariable(config.networkId,
                WifiConfiguration.AuthAlgorithm.varName);
        if (!TextUtils.isEmpty(value)) {
            String vals[] = value.split(" ");
            for (String val : vals) {
                int index =
                    lookupString(val, WifiConfiguration.AuthAlgorithm.strings);
                if (0 <= index) {
                    config.allowedAuthAlgorithms.set(index);
                }
            }
        }

        value = mWifiStateTracker.getNetworkVariable(config.networkId,
                WifiConfiguration.PairwiseCipher.varName);
        if (!TextUtils.isEmpty(value)) {
            String vals[] = value.split(" ");
            for (String val : vals) {
                int index =
                    lookupString(val, WifiConfiguration.PairwiseCipher.strings);
                if (0 <= index) {
                    config.allowedPairwiseCiphers.set(index);
                }
            }
        }

        value = mWifiStateTracker.getNetworkVariable(config.networkId,
                WifiConfiguration.GroupCipher.varName);
        if (!TextUtils.isEmpty(value)) {
            String vals[] = value.split(" ");
            for (String val : vals) {
                int index =
                    lookupString(val, WifiConfiguration.GroupCipher.strings);
                if (0 <= index) {
                    config.allowedGroupCiphers.set(index);
                }
            }
        }

        for (WifiConfiguration.EnterpriseField field :
                config.enterpriseFields) {
            value = mWifiStateTracker.getNetworkVariable(netId,
                    field.varName());
            if (!TextUtils.isEmpty(value)) {
                if (field != config.eap) value = removeDoubleQuotes(value);
                field.setValue(value);
            }
        }
    }

    private static String removeDoubleQuotes(String string) {
        if (string.length() <= 2) return "";
        return string.substring(1, string.length() - 1);
    }

    private static String convertToQuotedString(String string) {
        return "\"" + string + "\"";
    }

    /**
     * see {@link android.net.wifi.WifiManager#addOrUpdateNetwork(WifiConfiguration)}
     * @return the supplicant-assigned identifier for the new or updated
     * network if the operation succeeds, or {@code -1} if it fails
     */
    public int addOrUpdateNetwork(WifiConfiguration config) {
        enforceChangePermission();

        /*
         * If the supplied networkId is -1, we create a new empty
         * network configuration. Otherwise, the networkId should
         * refer to an existing configuration.
         */
        int netId = config.networkId;
        boolean newNetwork = netId == -1;
        boolean doReconfig = false;
        // networkId of -1 means we want to create a new network
        synchronized (mWifiStateTracker) {
            if (newNetwork) {
                netId = mWifiStateTracker.addNetwork();
                if (netId < 0) {
                    if (DBG) {
                        Slog.d(TAG, "Failed to add a network!");
                    }
                    return -1;
                }
                doReconfig = true;
            }
            mNeedReconfig = mNeedReconfig || doReconfig;
        }

        setVariables: {
            /*
             * Note that if a networkId for a non-existent network
             * was supplied, then the first setNetworkVariable()
             * will fail, so we don't bother to make a separate check
             * for the validity of the ID up front.
             */
            if (config.SSID != null &&
                    !mWifiStateTracker.setNetworkVariable(
                        netId,
                        WifiConfiguration.ssidVarName,
                        config.SSID)) {
                if (DBG) {
                    Slog.d(TAG, "failed to set SSID: "+config.SSID);
                }
                break setVariables;
            }

            if (config.BSSID != null &&
                    !mWifiStateTracker.setNetworkVariable(
                        netId,
                        WifiConfiguration.bssidVarName,
                        config.BSSID)) {
                if (DBG) {
                    Slog.d(TAG, "failed to set BSSID: "+config.BSSID);
                }
                break setVariables;
            }

            String allowedKeyManagementString =
                makeString(config.allowedKeyManagement, WifiConfiguration.KeyMgmt.strings);
            if (config.allowedKeyManagement.cardinality() != 0 &&
                    !mWifiStateTracker.setNetworkVariable(
                        netId,
                        WifiConfiguration.KeyMgmt.varName,
                        allowedKeyManagementString)) {
                if (DBG) {
                    Slog.d(TAG, "failed to set key_mgmt: "+
                            allowedKeyManagementString);
                }
                break setVariables;
            }

            String allowedProtocolsString =
                makeString(config.allowedProtocols, WifiConfiguration.Protocol.strings);
            if (config.allowedProtocols.cardinality() != 0 &&
                    !mWifiStateTracker.setNetworkVariable(
                        netId,
                        WifiConfiguration.Protocol.varName,
                        allowedProtocolsString)) {
                if (DBG) {
                    Slog.d(TAG, "failed to set proto: "+
                            allowedProtocolsString);
                }
                break setVariables;
            }

            String allowedAuthAlgorithmsString =
                makeString(config.allowedAuthAlgorithms, WifiConfiguration.AuthAlgorithm.strings);
            if (config.allowedAuthAlgorithms.cardinality() != 0 &&
                    !mWifiStateTracker.setNetworkVariable(
                        netId,
                        WifiConfiguration.AuthAlgorithm.varName,
                        allowedAuthAlgorithmsString)) {
                if (DBG) {
                    Slog.d(TAG, "failed to set auth_alg: "+
                            allowedAuthAlgorithmsString);
                }
                break setVariables;
            }

            String allowedPairwiseCiphersString =
                makeString(config.allowedPairwiseCiphers, WifiConfiguration.PairwiseCipher.strings);
            if (config.allowedPairwiseCiphers.cardinality() != 0 &&
                    !mWifiStateTracker.setNetworkVariable(
                        netId,
                        WifiConfiguration.PairwiseCipher.varName,
                        allowedPairwiseCiphersString)) {
                if (DBG) {
                    Slog.d(TAG, "failed to set pairwise: "+
                            allowedPairwiseCiphersString);
                }
                break setVariables;
            }

            String allowedGroupCiphersString =
                makeString(config.allowedGroupCiphers, WifiConfiguration.GroupCipher.strings);
            if (config.allowedGroupCiphers.cardinality() != 0 &&
                    !mWifiStateTracker.setNetworkVariable(
                        netId,
                        WifiConfiguration.GroupCipher.varName,
                        allowedGroupCiphersString)) {
                if (DBG) {
                    Slog.d(TAG, "failed to set group: "+
                            allowedGroupCiphersString);
                }
                break setVariables;
            }

            // Prevent client screw-up by passing in a WifiConfiguration we gave it
            // by preventing "*" as a key.
            if (config.preSharedKey != null && !config.preSharedKey.equals("*") &&
                    !mWifiStateTracker.setNetworkVariable(
                        netId,
                        WifiConfiguration.pskVarName,
                        config.preSharedKey)) {
                if (DBG) {
                    Slog.d(TAG, "failed to set psk: "+config.preSharedKey);
                }
                break setVariables;
            }

            boolean hasSetKey = false;
            if (config.wepKeys != null) {
                for (int i = 0; i < config.wepKeys.length; i++) {
                    // Prevent client screw-up by passing in a WifiConfiguration we gave it
                    // by preventing "*" as a key.
                    if (config.wepKeys[i] != null && !config.wepKeys[i].equals("*")) {
                        if (!mWifiStateTracker.setNetworkVariable(
                                    netId,
                                    WifiConfiguration.wepKeyVarNames[i],
                                    config.wepKeys[i])) {
                            if (DBG) {
                                Slog.d(TAG,
                                        "failed to set wep_key"+i+": " +
                                        config.wepKeys[i]);
                            }
                            break setVariables;
                        }
                        hasSetKey = true;
                    }
                }
            }

            if (hasSetKey) {
                if (!mWifiStateTracker.setNetworkVariable(
                            netId,
                            WifiConfiguration.wepTxKeyIdxVarName,
                            Integer.toString(config.wepTxKeyIndex))) {
                    if (DBG) {
                        Slog.d(TAG,
                                "failed to set wep_tx_keyidx: "+
                                config.wepTxKeyIndex);
                    }
                    break setVariables;
                }
            }

            if (!mWifiStateTracker.setNetworkVariable(
                        netId,
                        WifiConfiguration.priorityVarName,
                        Integer.toString(config.priority))) {
                if (DBG) {
                    Slog.d(TAG, config.SSID + ": failed to set priority: "
                            +config.priority);
                }
                break setVariables;
            }

            if (config.hiddenSSID && !mWifiStateTracker.setNetworkVariable(
                        netId,
                        WifiConfiguration.hiddenSSIDVarName,
                        Integer.toString(config.hiddenSSID ? 1 : 0))) {
                if (DBG) {
                    Slog.d(TAG, config.SSID + ": failed to set hiddenSSID: "+
                            config.hiddenSSID);
                }
                break setVariables;
            }

            for (WifiConfiguration.EnterpriseField field
                    : config.enterpriseFields) {
                String varName = field.varName();
                String value = field.value();
                if (value != null) {
                    if (field != config.eap) {
                        value = (value.length() == 0) ? "NULL" : convertToQuotedString(value);
                    }
                    if (!mWifiStateTracker.setNetworkVariable(
                                netId,
                                varName,
                                value)) {
                        if (DBG) {
                            Slog.d(TAG, config.SSID + ": failed to set " + varName +
                                    ": " + value);
                        }
                        break setVariables;
                    }
                }
            }
            return netId;
        }

        /*
         * For an update, if one of the setNetworkVariable operations fails,
         * we might want to roll back all the changes already made. But the
         * chances are that if anything is going to go wrong, it'll happen
         * the first time we try to set one of the variables.
         */
        if (newNetwork) {
            removeNetwork(netId);
            if (DBG) {
                Slog.d(TAG,
                        "Failed to set a network variable, removed network: "
                        + netId);
            }
        }
        return -1;
    }

    private static String makeString(BitSet set, String[] strings) {
        StringBuffer buf = new StringBuffer();
        int nextSetBit = -1;

        /* Make sure all set bits are in [0, strings.length) to avoid
         * going out of bounds on strings.  (Shouldn't happen, but...) */
        set = set.get(0, strings.length);

        while ((nextSetBit = set.nextSetBit(nextSetBit + 1)) != -1) {
            buf.append(strings[nextSetBit].replace('_', '-')).append(' ');
        }

        // remove trailing space
        if (set.cardinality() > 0) {
            buf.setLength(buf.length() - 1);
        }

        return buf.toString();
    }

    private static int lookupString(String string, String[] strings) {
        int size = strings.length;

        string = string.replace('-', '_');

        for (int i = 0; i < size; i++)
            if (string.equals(strings[i]))
                return i;

        if (DBG) {
            // if we ever get here, we should probably add the
            // value to WifiConfiguration to reflect that it's
            // supported by the WPA supplicant
            Slog.w(TAG, "Failed to look-up a string: " + string);
        }

        return -1;
    }

    /**
     * See {@link android.net.wifi.WifiManager#removeNetwork(int)}
     * @param netId the integer that identifies the network configuration
     * to the supplicant
     * @return {@code true} if the operation succeeded
     */
    public boolean removeNetwork(int netId) {
        enforceChangePermission();

        return mWifiStateTracker.removeNetwork(netId);
    }

    /**
     * See {@link android.net.wifi.WifiManager#enableNetwork(int, boolean)}
     * @param netId the integer that identifies the network configuration
     * to the supplicant
     * @param disableOthers if true, disable all other networks.
     * @return {@code true} if the operation succeeded
     */
    public boolean enableNetwork(int netId, boolean disableOthers) {
        enforceChangePermission();

        String ifname = mWifiStateTracker.getInterfaceName();
        NetworkUtils.enableInterface(ifname);
        boolean result = mWifiStateTracker.enableNetwork(netId, disableOthers);
        if (!result) {
            NetworkUtils.disableInterface(ifname);
        }
        return result;
    }

    /**
     * See {@link android.net.wifi.WifiManager#disableNetwork(int)}
     * @param netId the integer that identifies the network configuration
     * to the supplicant
     * @return {@code true} if the operation succeeded
     */
    public boolean disableNetwork(int netId) {
        enforceChangePermission();

        return mWifiStateTracker.disableNetwork(netId);
    }

    /**
     * See {@link android.net.wifi.WifiManager#getConnectionInfo()}
     * @return the Wi-Fi information, contained in {@link WifiInfo}.
     */
    public WifiInfo getConnectionInfo() {
        enforceAccessPermission();
        /*
         * Make sure we have the latest information, by sending
         * a status request to the supplicant.
         */
        return mWifiStateTracker.requestConnectionInfo();
    }

    /**
     * Return the results of the most recent access point scan, in the form of
     * a list of {@link ScanResult} objects.
     * @return the list of results
     */
    public List<ScanResult> getScanResults() {
        enforceAccessPermission();
        String reply;

        reply = mWifiStateTracker.scanResults();
        if (reply == null) {
            return null;
        }

        List<ScanResult> scanList = new ArrayList();

        int lineCount = 0;

        int replyLen = reply.length();
        // Parse the result string, keeping in mind that the last line does
        // not end with a newline.
        for (int lineBeg = 0, lineEnd = 0; lineEnd <= replyLen; ++lineEnd) {
            if (lineEnd == replyLen || reply.charAt(lineEnd) == '\n') {
                ++lineCount;
                /*
                 * Skip the first line, which is a header
                 */
                if (lineCount == 1) {
                    lineBeg = lineEnd + 1;
                    continue;
                }
                if (lineEnd > lineBeg) {
                    String line = reply.substring(lineBeg, lineEnd);
                    ScanResult scanResult = parseScanResult(line);
                    if (scanResult != null) {
                        scanList.add(scanResult);
                    } else if (DBG) {
                        Slog.w(TAG, "misformatted scan result for: " + line);
                    }
                }
                lineBeg = lineEnd + 1;
            }
        }
        mWifiStateTracker.setScanResultsList(scanList);
        return scanList;
    }

    /**
     * Parse the scan result line passed to us by wpa_supplicant (helper).
     * @param line the line to parse
     * @return the {@link ScanResult} object
     */
    private ScanResult parseScanResult(String line) {
        ScanResult scanResult = null;
        if (line != null) {
            /*
             * Cache implementation (LinkedHashMap) is not synchronized, thus,
             * must synchronized here!
             */
            synchronized (mScanResultCache) {
                String[] result = scanResultPattern.split(line);
                if (3 <= result.length && result.length <= 5) {
                    String bssid = result[0];
                    // bssid | frequency | level | flags | ssid
                    int frequency;
                    int level;
                    try {
                        frequency = Integer.parseInt(result[1]);
                        level = Integer.parseInt(result[2]);
                        /* some implementations avoid negative values by adding 256
                         * so we need to adjust for that here.
                         */
                        if (level > 0) level -= 256;
                    } catch (NumberFormatException e) {
                        frequency = 0;
                        level = 0;
                    }

                    /*
                     * The formatting of the results returned by
                     * wpa_supplicant is intended to make the fields
                     * line up nicely when printed,
                     * not to make them easy to parse. So we have to
                     * apply some heuristics to figure out which field
                     * is the SSID and which field is the flags.
                     */
                    String ssid;
                    String flags;
                    if (result.length == 4) {
                        if (result[3].charAt(0) == '[') {
                            flags = result[3];
                            ssid = "";
                        } else {
                            flags = "";
                            ssid = result[3];
                        }
                    } else if (result.length == 5) {
                        flags = result[3];
                        ssid = result[4];
                    } else {
                        // Here, we must have 3 fields: no flags and ssid
                        // set
                        flags = "";
                        ssid = "";
                    }

                    // bssid + ssid is the hash key
                    String key = bssid + ssid;
                    scanResult = mScanResultCache.get(key);
                    if (scanResult != null) {
                        scanResult.level = level;
                        scanResult.SSID = ssid;
                        scanResult.capabilities = flags;
                        scanResult.frequency = frequency;
                    } else {
                        // Do not add scan results that have no SSID set
                        if (0 < ssid.trim().length()) {
                            scanResult =
                                new ScanResult(
                                    ssid, bssid, flags, level, frequency);
                            mScanResultCache.put(key, scanResult);
                        }
                    }
                } else {
                    Slog.w(TAG, "Misformatted scan result text with " +
                          result.length + " fields: " + line);
                }
            }
        }

        return scanResult;
    }

    /**
     * Parse the "flags" field passed back in a scan result by wpa_supplicant,
     * and construct a {@code WifiConfiguration} that describes the encryption,
     * key management, and authenticaion capabilities of the access point.
     * @param flags the string returned by wpa_supplicant
     * @return the {@link WifiConfiguration} object, filled in
     */
    WifiConfiguration parseScanFlags(String flags) {
        WifiConfiguration config = new WifiConfiguration();

        if (flags.length() == 0) {
            config.allowedKeyManagement.set(WifiConfiguration.KeyMgmt.NONE);
        }
        // ... to be implemented
        return config;
    }

    /**
     * Tell the supplicant to persist the current list of configured networks.
     * @return {@code true} if the operation succeeded
     */
    public boolean saveConfiguration() {
        boolean result;
        enforceChangePermission();

        synchronized (mWifiStateTracker) {
            result = mWifiStateTracker.saveConfig();
            if (result && mNeedReconfig) {
                mNeedReconfig = false;
                result = mWifiStateTracker.reloadConfig();

                if (result) {
                    Intent intent = new Intent(WifiManager.NETWORK_IDS_CHANGED_ACTION);
                    mContext.sendBroadcast(intent);
                }
            }
        }
        // Inform the backup manager about a data change
        IBackupManager ibm = IBackupManager.Stub.asInterface(
                ServiceManager.getService(Context.BACKUP_SERVICE));
        if (ibm != null) {
            try {
                ibm.dataChanged("com.android.providers.settings");
            } catch (Exception e) {
                // Try again later
            }
        }
        return result;
    }

    /**
     * Set the number of radio frequency channels that are allowed to be used
     * in the current regulatory domain. This method should be used only
     * if the correct number of channels cannot be determined automatically
     * for some reason. If the operation is successful, the new value may be
     * persisted as a Secure setting.
     * @param numChannels the number of allowed channels. Must be greater than 0
     * and less than or equal to 16.
     * @param persist {@code true} if the setting should be remembered.
     * @return {@code true} if the operation succeeds, {@code false} otherwise, e.g.,
     * {@code numChannels} is outside the valid range.
     */
    public boolean setNumAllowedChannels(int numChannels, boolean persist) {
        Slog.i(TAG, "WifiService trying to setNumAllowed to "+numChannels+
                " with persist set to "+persist);
        enforceChangePermission();

        /*
         * Validate the argument. We'd like to let the Wi-Fi driver do this,
         * but if Wi-Fi isn't currently enabled, that's not possible, and
         * we want to persist the setting anyway,so that it will take
         * effect when Wi-Fi does become enabled.
         */
        boolean found = false;
        for (int validChan : sValidRegulatoryChannelCounts) {
            if (validChan == numChannels) {
                found = true;
                break;
            }
        }
        if (!found) {
            return false;
        }

        if (mWifiHandler == null) return false;

        Message.obtain(mWifiHandler,
                MESSAGE_SET_CHANNELS, numChannels, (persist ? 1 : 0)).sendToTarget();

        return true;
    }

    /**
     * sets the number of allowed radio frequency channels synchronously
     * @param numChannels the number of allowed channels. Must be greater than 0
     * and less than or equal to 16.
     * @param persist {@code true} if the setting should be remembered.
     * @return {@code true} if the operation succeeds, {@code false} otherwise
     */
    private boolean setNumAllowedChannelsBlocking(int numChannels, boolean persist) {
        if (persist) {
            Settings.Secure.putInt(mContext.getContentResolver(),
                    Settings.Secure.WIFI_NUM_ALLOWED_CHANNELS,
                    numChannels);
        }
        return mWifiStateTracker.setNumAllowedChannels(numChannels);
    }

    /**
     * Return the number of frequency channels that are allowed
     * to be used in the current regulatory domain.
     * @return the number of allowed channels, or {@code -1} if an error occurs
     */
    public int getNumAllowedChannels() {
        int numChannels;

        enforceAccessPermission();

        /*
         * If we can't get the value from the driver (e.g., because
         * Wi-Fi is not currently enabled), get the value from
         * Settings.
         */
        numChannels = mWifiStateTracker.getNumAllowedChannels();
        if (numChannels < 0) {
            numChannels = Settings.Secure.getInt(mContext.getContentResolver(),
                    Settings.Secure.WIFI_NUM_ALLOWED_CHANNELS,
                    -1);
        }
        return numChannels;
    }

    /**
     * Return the list of valid values for the number of allowed radio channels
     * for various regulatory domains.
     * @return the list of channel counts
     */
    public int[] getValidChannelCounts() {
        enforceAccessPermission();
        return sValidRegulatoryChannelCounts;
    }

    /**
     * Return the DHCP-assigned addresses from the last successful DHCP request,
     * if any.
     * @return the DHCP information
     */
    public DhcpInfo getDhcpInfo() {
        enforceAccessPermission();
        return mWifiStateTracker.getDhcpInfo();
    }

    private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            String action = intent.getAction();

            long idleMillis =
                Settings.Secure.getLong(mContext.getContentResolver(),
                                        Settings.Secure.WIFI_IDLE_MS, DEFAULT_IDLE_MILLIS);
            int stayAwakeConditions =
                Settings.System.getInt(mContext.getContentResolver(),
                                       Settings.System.STAY_ON_WHILE_PLUGGED_IN, 0);
            if (action.equals(Intent.ACTION_SCREEN_ON)) {
                Slog.d(TAG, "ACTION_SCREEN_ON");
                mAlarmManager.cancel(mIdleIntent);
                mDeviceIdle = false;
                mScreenOff = false;
                mWifiStateTracker.enableRssiPolling(true);
            } else if (action.equals(Intent.ACTION_SCREEN_OFF)) {
                Slog.d(TAG, "ACTION_SCREEN_OFF");
                mScreenOff = true;
                mWifiStateTracker.enableRssiPolling(false);
                /*
                 * Set a timer to put Wi-Fi to sleep, but only if the screen is off
                 * AND the "stay on while plugged in" setting doesn't match the
                 * current power conditions (i.e, not plugged in, plugged in to USB,
                 * or plugged in to AC).
                 */
                if (!shouldWifiStayAwake(stayAwakeConditions, mPluggedType)) {
                    WifiInfo info = mWifiStateTracker.requestConnectionInfo();
                    if (info.getSupplicantState() != SupplicantState.COMPLETED) {
                        // we used to go to sleep immediately, but this caused some race conditions
                        // we don't have time to track down for this release.  Delay instead, but not
                        // as long as we would if connected (below)
                        // TODO - fix the race conditions and switch back to the immediate turn-off
                        long triggerTime = System.currentTimeMillis() + (2*60*1000); // 2 min
                        Slog.d(TAG, "setting ACTION_DEVICE_IDLE timer for 120,000 ms");
                        mAlarmManager.set(AlarmManager.RTC_WAKEUP, triggerTime, mIdleIntent);
                        //  // do not keep Wifi awake when screen is off if Wifi is not associated
                        //  mDeviceIdle = true;
                        //  updateWifiState();
                    } else {
                        long triggerTime = System.currentTimeMillis() + idleMillis;
                        Slog.d(TAG, "setting ACTION_DEVICE_IDLE timer for " + idleMillis + "ms");
                        mAlarmManager.set(AlarmManager.RTC_WAKEUP, triggerTime, mIdleIntent);
                    }
                }
                /* we can return now -- there's nothing to do until we get the idle intent back */
                return;
            } else if (action.equals(ACTION_DEVICE_IDLE)) {
                Slog.d(TAG, "got ACTION_DEVICE_IDLE");
                mDeviceIdle = true;
            } else if (action.equals(Intent.ACTION_BATTERY_CHANGED)) {
                /*
                 * Set a timer to put Wi-Fi to sleep, but only if the screen is off
                 * AND we are transitioning from a state in which the device was supposed
                 * to stay awake to a state in which it is not supposed to stay awake.
                 * If "stay awake" state is not changing, we do nothing, to avoid resetting
                 * the already-set timer.
                 */
                int pluggedType = intent.getIntExtra("plugged", 0);
                Slog.d(TAG, "ACTION_BATTERY_CHANGED pluggedType: " + pluggedType);
                if (mScreenOff && shouldWifiStayAwake(stayAwakeConditions, mPluggedType) &&
                        !shouldWifiStayAwake(stayAwakeConditions, pluggedType)) {
                    long triggerTime = System.currentTimeMillis() + idleMillis;
                    Slog.d(TAG, "setting ACTION_DEVICE_IDLE timer for " + idleMillis + "ms");
                    mAlarmManager.set(AlarmManager.RTC_WAKEUP, triggerTime, mIdleIntent);
                    mPluggedType = pluggedType;
                    return;
                }
                mPluggedType = pluggedType;
            } else if (action.equals(BluetoothA2dp.ACTION_SINK_STATE_CHANGED)) {
                BluetoothA2dp a2dp = new BluetoothA2dp(mContext);
                Set<BluetoothDevice> sinks = a2dp.getConnectedSinks();
                boolean isBluetoothPlaying = false;
                for (BluetoothDevice sink : sinks) {
                    if (a2dp.getSinkState(sink) == BluetoothA2dp.STATE_PLAYING) {
                        isBluetoothPlaying = true;
                    }
                }
                mWifiStateTracker.setBluetoothScanMode(isBluetoothPlaying);

            } else {
                return;
            }

            updateWifiState();
        }

        /**
         * Determines whether the Wi-Fi chipset should stay awake or be put to
         * sleep. Looks at the setting for the sleep policy and the current
         * conditions.
         *
         * @see #shouldDeviceStayAwake(int, int)
         */
        private boolean shouldWifiStayAwake(int stayAwakeConditions, int pluggedType) {
            int wifiSleepPolicy = Settings.System.getInt(mContext.getContentResolver(),
                    Settings.System.WIFI_SLEEP_POLICY, Settings.System.WIFI_SLEEP_POLICY_DEFAULT);

            if (wifiSleepPolicy == Settings.System.WIFI_SLEEP_POLICY_NEVER) {
                // Never sleep
                return true;
            } else if ((wifiSleepPolicy == Settings.System.WIFI_SLEEP_POLICY_NEVER_WHILE_PLUGGED) &&
                    (pluggedType != 0)) {
                // Never sleep while plugged, and we're plugged
                return true;
            } else {
                // Default
                return shouldDeviceStayAwake(stayAwakeConditions, pluggedType);
            }
        }

        /**
         * Determine whether the bit value corresponding to {@code pluggedType} is set in
         * the bit string {@code stayAwakeConditions}. Because a {@code pluggedType} value
         * of {@code 0} isn't really a plugged type, but rather an indication that the
         * device isn't plugged in at all, there is no bit value corresponding to a
         * {@code pluggedType} value of {@code 0}. That is why we shift by
         * {@code pluggedType — 1} instead of by {@code pluggedType}.
         * @param stayAwakeConditions a bit string specifying which "plugged types" should
         * keep the device (and hence Wi-Fi) awake.
         * @param pluggedType the type of plug (USB, AC, or none) for which the check is
         * being made
         * @return {@code true} if {@code pluggedType} indicates that the device is
         * supposed to stay awake, {@code false} otherwise.
         */
        private boolean shouldDeviceStayAwake(int stayAwakeConditions, int pluggedType) {
            return (stayAwakeConditions & pluggedType) != 0;
        }
    };

    private void sendEnableMessage(boolean enable, boolean persist, int uid) {
        Message msg = Message.obtain(mWifiHandler,
                                     (enable ? MESSAGE_ENABLE_WIFI : MESSAGE_DISABLE_WIFI),
                                     (persist ? 1 : 0), uid);
        msg.sendToTarget();
    }

    private void sendStartMessage(boolean scanOnlyMode) {
        Message.obtain(mWifiHandler, MESSAGE_START_WIFI, scanOnlyMode ? 1 : 0, 0).sendToTarget();
    }

    private void sendAccessPointMessage(boolean enable, WifiConfiguration wifiConfig, int uid) {
        Message.obtain(mWifiHandler,
                (enable ? MESSAGE_START_ACCESS_POINT : MESSAGE_STOP_ACCESS_POINT),
                uid, 0, wifiConfig).sendToTarget();
    }

    private void updateWifiState() {
        // send a message so it's all serialized
        Message.obtain(mWifiHandler, MESSAGE_UPDATE_STATE, 0, 0).sendToTarget();
    }

    private void doUpdateWifiState() {
        boolean wifiEnabled = getPersistedWifiEnabled();
        boolean airplaneMode = isAirplaneModeOn() && !mAirplaneModeOverwridden;
        boolean lockHeld = mLocks.hasLocks();
        int strongestLockMode;
        boolean wifiShouldBeEnabled = wifiEnabled && !airplaneMode;
        boolean wifiShouldBeStarted = !mDeviceIdle || lockHeld;
        if (mDeviceIdle && lockHeld) {
            strongestLockMode = mLocks.getStrongestLockMode();
        } else {
            strongestLockMode = WifiManager.WIFI_MODE_FULL;
        }

        synchronized (mWifiHandler) {
            if ((mWifiStateTracker.getWifiState() == WIFI_STATE_ENABLING) && !airplaneMode) {
                return;
            }

            /* Disable tethering when airplane mode is enabled */
            if (airplaneMode &&
                (mWifiApState == WIFI_AP_STATE_ENABLING || mWifiApState == WIFI_AP_STATE_ENABLED)) {
                sWakeLock.acquire();
                sendAccessPointMessage(false, null, mLastApEnableUid);
            }

            if (wifiShouldBeEnabled) {
                if (wifiShouldBeStarted) {
                    sWakeLock.acquire();
                    sendEnableMessage(true, false, mLastEnableUid);
                    sWakeLock.acquire();
                    sendStartMessage(strongestLockMode == WifiManager.WIFI_MODE_SCAN_ONLY);
                } else if (!mWifiStateTracker.isDriverStopped()) {
                    int wakeLockTimeout =
                            Settings.Secure.getInt(
                                    mContext.getContentResolver(),
                                    Settings.Secure.WIFI_MOBILE_DATA_TRANSITION_WAKELOCK_TIMEOUT_MS,
                                    DEFAULT_WAKELOCK_TIMEOUT);
                    /*
                     * We are assuming that ConnectivityService can make
                     * a transition to cellular data within wakeLockTimeout time.
                     * The wakelock is released by the delayed message.
                     */
                    sDriverStopWakeLock.acquire();
                    mWifiHandler.sendEmptyMessage(MESSAGE_STOP_WIFI);
                    mWifiHandler.sendEmptyMessageDelayed(MESSAGE_RELEASE_WAKELOCK, wakeLockTimeout);
                }
            } else {
                sWakeLock.acquire();
                sendEnableMessage(false, false, mLastEnableUid);
            }
        }
    }

    private void registerForBroadcasts() {
        IntentFilter intentFilter = new IntentFilter();
        intentFilter.addAction(Intent.ACTION_SCREEN_ON);
        intentFilter.addAction(Intent.ACTION_SCREEN_OFF);
        intentFilter.addAction(Intent.ACTION_BATTERY_CHANGED);
        intentFilter.addAction(ACTION_DEVICE_IDLE);
        intentFilter.addAction(BluetoothA2dp.ACTION_SINK_STATE_CHANGED);
        mContext.registerReceiver(mReceiver, intentFilter);
    }

    private boolean isAirplaneSensitive() {
        String airplaneModeRadios = Settings.System.getString(mContext.getContentResolver(),
                Settings.System.AIRPLANE_MODE_RADIOS);
        return airplaneModeRadios == null
            || airplaneModeRadios.contains(Settings.System.RADIO_WIFI);
    }

    private boolean isAirplaneToggleable() {
        String toggleableRadios = Settings.System.getString(mContext.getContentResolver(),
                Settings.System.AIRPLANE_MODE_TOGGLEABLE_RADIOS);
        return toggleableRadios != null
            && toggleableRadios.contains(Settings.System.RADIO_WIFI);
    }

    /**
     * Returns true if Wi-Fi is sensitive to airplane mode, and airplane mode is
     * currently on.
     * @return {@code true} if airplane mode is on.
     */
    private boolean isAirplaneModeOn() {
        return isAirplaneSensitive() && Settings.System.getInt(mContext.getContentResolver(),
                Settings.System.AIRPLANE_MODE_ON, 0) == 1;
    }

    /**
     * Handler that allows posting to the WifiThread.
     */
    private class WifiHandler extends Handler {
        public WifiHandler(Looper looper) {
            super(looper);
        }

        @Override
        public void handleMessage(Message msg) {
            switch (msg.what) {

                case MESSAGE_ENABLE_WIFI:
                    setWifiEnabledBlocking(true, msg.arg1 == 1, msg.arg2);
                    if (mWifiWatchdogService == null) {
                        mWifiWatchdogService = new WifiWatchdogService(mContext, mWifiStateTracker);
                    }
                    sWakeLock.release();
                    break;

                case MESSAGE_START_WIFI:
                    mWifiStateTracker.setScanOnlyMode(msg.arg1 != 0);
                    mWifiStateTracker.restart();
                    sWakeLock.release();
                    break;

                case MESSAGE_UPDATE_STATE:
                    doUpdateWifiState();
                    break;

                case MESSAGE_DISABLE_WIFI:
                    // a non-zero msg.arg1 value means the "enabled" setting
                    // should be persisted
                    setWifiEnabledBlocking(false, msg.arg1 == 1, msg.arg2);
                    mWifiWatchdogService = null;
                    sWakeLock.release();
                    break;

                case MESSAGE_STOP_WIFI:
                    mWifiStateTracker.disconnectAndStop();
                    // don't release wakelock
                    break;

                case MESSAGE_RELEASE_WAKELOCK:
                    sDriverStopWakeLock.release();
                    break;

                case MESSAGE_START_ACCESS_POINT:
                    setWifiApEnabledBlocking(true,
                                             msg.arg1,
                                             (WifiConfiguration) msg.obj);
                    sWakeLock.release();
                    break;

                case MESSAGE_STOP_ACCESS_POINT:
                    setWifiApEnabledBlocking(false,
                                             msg.arg1,
                                             (WifiConfiguration) msg.obj);
                    sWakeLock.release();
                    break;

                case MESSAGE_SET_CHANNELS:
                    setNumAllowedChannelsBlocking(msg.arg1, msg.arg2 == 1);
                    break;

            }
        }
    }

    @Override
    protected void dump(FileDescriptor fd, PrintWriter pw, String[] args) {
        if (mContext.checkCallingOrSelfPermission(android.Manifest.permission.DUMP)
                != PackageManager.PERMISSION_GRANTED) {
            pw.println("Permission Denial: can't dump WifiService from from pid="
                    + Binder.getCallingPid()
                    + ", uid=" + Binder.getCallingUid());
            return;
        }
        pw.println("Wi-Fi is " + stateName(mWifiStateTracker.getWifiState()));
        pw.println("Stay-awake conditions: " +
                Settings.System.getInt(mContext.getContentResolver(),
                                       Settings.System.STAY_ON_WHILE_PLUGGED_IN, 0));
        pw.println();

        pw.println("Internal state:");
        pw.println(mWifiStateTracker);
        pw.println();
        pw.println("Latest scan results:");
        List<ScanResult> scanResults = mWifiStateTracker.getScanResultsList();
        if (scanResults != null && scanResults.size() != 0) {
            pw.println("  BSSID              Frequency   RSSI  Flags             SSID");
            for (ScanResult r : scanResults) {
                pw.printf("  %17s  %9d  %5d  %-16s  %s%n",
                                         r.BSSID,
                                         r.frequency,
                                         r.level,
                                         r.capabilities,
                                         r.SSID == null ? "" : r.SSID);
            }
        }
        pw.println();
        pw.println("Locks acquired: " + mFullLocksAcquired + " full, " +
                mScanLocksAcquired + " scan");
        pw.println("Locks released: " + mFullLocksReleased + " full, " +
                mScanLocksReleased + " scan");
        pw.println();
        pw.println("Locks held:");
        mLocks.dump(pw);
    }

    private static String stateName(int wifiState) {
        switch (wifiState) {
            case WIFI_STATE_DISABLING:
                return "disabling";
            case WIFI_STATE_DISABLED:
                return "disabled";
            case WIFI_STATE_ENABLING:
                return "enabling";
            case WIFI_STATE_ENABLED:
                return "enabled";
            case WIFI_STATE_UNKNOWN:
                return "unknown state";
            default:
                return "[invalid state]";
        }
    }

    private class WifiLock extends DeathRecipient {
        WifiLock(int lockMode, String tag, IBinder binder) {
            super(lockMode, tag, binder);
        }

        public void binderDied() {
            synchronized (mLocks) {
                releaseWifiLockLocked(mBinder);
            }
        }

        public String toString() {
            return "WifiLock{" + mTag + " type=" + mMode + " binder=" + mBinder + "}";
        }
    }

    private class LockList {
        private List<WifiLock> mList;

        private LockList() {
            mList = new ArrayList<WifiLock>();
        }

        private synchronized boolean hasLocks() {
            return !mList.isEmpty();
        }

        private synchronized int getStrongestLockMode() {
            if (mList.isEmpty()) {
                return WifiManager.WIFI_MODE_FULL;
            }
            for (WifiLock l : mList) {
                if (l.mMode == WifiManager.WIFI_MODE_FULL) {
                    return WifiManager.WIFI_MODE_FULL;
                }
            }
            return WifiManager.WIFI_MODE_SCAN_ONLY;
        }

        private void addLock(WifiLock lock) {
            if (findLockByBinder(lock.mBinder) < 0) {
                mList.add(lock);
            }
        }

        private WifiLock removeLock(IBinder binder) {
            int index = findLockByBinder(binder);
            if (index >= 0) {
                WifiLock ret = mList.remove(index);
                ret.unlinkDeathRecipient();
                return ret;
            } else {
                return null;
            }
        }

        private int findLockByBinder(IBinder binder) {
            int size = mList.size();
            for (int i = size - 1; i >= 0; i--)
                if (mList.get(i).mBinder == binder)
                    return i;
            return -1;
        }

        private void dump(PrintWriter pw) {
            for (WifiLock l : mList) {
                pw.print("    ");
                pw.println(l);
            }
        }
    }

    public boolean acquireWifiLock(IBinder binder, int lockMode, String tag) {
        mContext.enforceCallingOrSelfPermission(android.Manifest.permission.WAKE_LOCK, null);
        if (lockMode != WifiManager.WIFI_MODE_FULL && lockMode != WifiManager.WIFI_MODE_SCAN_ONLY) {
            return false;
        }
        WifiLock wifiLock = new WifiLock(lockMode, tag, binder);
        synchronized (mLocks) {
            return acquireWifiLockLocked(wifiLock);
        }
    }

    private boolean acquireWifiLockLocked(WifiLock wifiLock) {
        Slog.d(TAG, "acquireWifiLockLocked: " + wifiLock);

        mLocks.addLock(wifiLock);

        int uid = Binder.getCallingUid();
        long ident = Binder.clearCallingIdentity();
        try {
            switch(wifiLock.mMode) {
            case WifiManager.WIFI_MODE_FULL:
                ++mFullLocksAcquired;
                mBatteryStats.noteFullWifiLockAcquired(uid);
                break;
            case WifiManager.WIFI_MODE_SCAN_ONLY:
                ++mScanLocksAcquired;
                mBatteryStats.noteScanWifiLockAcquired(uid);
                break;
            }
        } catch (RemoteException e) {
        } finally {
            Binder.restoreCallingIdentity(ident);
        }

        updateWifiState();
        return true;
    }

    public boolean releaseWifiLock(IBinder lock) {
        mContext.enforceCallingOrSelfPermission(android.Manifest.permission.WAKE_LOCK, null);
        synchronized (mLocks) {
            return releaseWifiLockLocked(lock);
        }
    }

    private boolean releaseWifiLockLocked(IBinder lock) {
        boolean hadLock;

        WifiLock wifiLock = mLocks.removeLock(lock);

        Slog.d(TAG, "releaseWifiLockLocked: " + wifiLock);

        hadLock = (wifiLock != null);

        if (hadLock) {
            int uid = Binder.getCallingUid();
            long ident = Binder.clearCallingIdentity();
            try {
                switch(wifiLock.mMode) {
                    case WifiManager.WIFI_MODE_FULL:
                        ++mFullLocksReleased;
                        mBatteryStats.noteFullWifiLockReleased(uid);
                        break;
                    case WifiManager.WIFI_MODE_SCAN_ONLY:
                        ++mScanLocksReleased;
                        mBatteryStats.noteScanWifiLockReleased(uid);
                        break;
                }
            } catch (RemoteException e) {
            } finally {
                Binder.restoreCallingIdentity(ident);
            }
        }
        // TODO - should this only happen if you hadLock?
        updateWifiState();
        return hadLock;
    }

    private abstract class DeathRecipient
            implements IBinder.DeathRecipient {
        String mTag;
        int mMode;
        IBinder mBinder;

        DeathRecipient(int mode, String tag, IBinder binder) {
            super();
            mTag = tag;
            mMode = mode;
            mBinder = binder;
            try {
                mBinder.linkToDeath(this, 0);
            } catch (RemoteException e) {
                binderDied();
            }
        }

        void unlinkDeathRecipient() {
            mBinder.unlinkToDeath(this, 0);
        }
    }

    private class Multicaster extends DeathRecipient {
        Multicaster(String tag, IBinder binder) {
            super(Binder.getCallingUid(), tag, binder);
        }

        public void binderDied() {
            Slog.e(TAG, "Multicaster binderDied");
            synchronized (mMulticasters) {
                int i = mMulticasters.indexOf(this);
                if (i != -1) {
                    removeMulticasterLocked(i, mMode);
                }
            }
        }

        public String toString() {
            return "Multicaster{" + mTag + " binder=" + mBinder + "}";
        }

        public int getUid() {
            return mMode;
        }
    }

    public void initializeMulticastFiltering() {
        enforceMulticastChangePermission();

        synchronized (mMulticasters) {
            // if anybody had requested filters be off, leave off
            if (mMulticasters.size() != 0) {
                return;
            } else {
                mWifiStateTracker.startPacketFiltering();
            }
        }
    }

    public void acquireMulticastLock(IBinder binder, String tag) {
        enforceMulticastChangePermission();

        synchronized (mMulticasters) {
            mMulticastEnabled++;
            mMulticasters.add(new Multicaster(tag, binder));
            // Note that we could call stopPacketFiltering only when
            // our new size == 1 (first call), but this function won't
            // be called often and by making the stopPacket call each
            // time we're less fragile and self-healing.
            mWifiStateTracker.stopPacketFiltering();
        }

        int uid = Binder.getCallingUid();
        Long ident = Binder.clearCallingIdentity();
        try {
            mBatteryStats.noteWifiMulticastEnabled(uid);
        } catch (RemoteException e) {
        } finally {
            Binder.restoreCallingIdentity(ident);
        }
    }

    public void releaseMulticastLock() {
        enforceMulticastChangePermission();

        int uid = Binder.getCallingUid();
        synchronized (mMulticasters) {
            mMulticastDisabled++;
            int size = mMulticasters.size();
            for (int i = size - 1; i >= 0; i--) {
                Multicaster m = mMulticasters.get(i);
                if ((m != null) && (m.getUid() == uid)) {
                    removeMulticasterLocked(i, uid);
                }
            }
        }
    }

    private void removeMulticasterLocked(int i, int uid)
    {
        Multicaster removed = mMulticasters.remove(i);

        if (removed != null) {
            removed.unlinkDeathRecipient();
        }
        if (mMulticasters.size() == 0) {
            mWifiStateTracker.startPacketFiltering();
        }

        Long ident = Binder.clearCallingIdentity();
        try {
            mBatteryStats.noteWifiMulticastDisabled(uid);
        } catch (RemoteException e) {
        } finally {
            Binder.restoreCallingIdentity(ident);
        }
    }

    public boolean isMulticastEnabled() {
        enforceAccessPermission();

        synchronized (mMulticasters) {
            return (mMulticasters.size() > 0);
        }
    }
}

Other Android examples (source code examples)

Here is a short list of links related to this Android WifiService.java source code file:

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