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      1 /*
      2  * Copyright (C) 2010 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package android.net.wifi;
     18 
     19 import android.content.Context;
     20 import android.net.wifi.WifiConfiguration.KeyMgmt;
     21 import android.os.Environment;
     22 import android.os.Message;
     23 import android.os.Handler;
     24 import android.os.HandlerThread;
     25 import android.util.Log;
     26 
     27 import java.io.BufferedInputStream;
     28 import java.io.BufferedOutputStream;
     29 import java.io.DataInputStream;
     30 import java.io.DataOutputStream;
     31 import java.io.FileInputStream;
     32 import java.io.FileOutputStream;
     33 import java.io.IOException;
     34 import java.net.InetAddress;
     35 import java.util.UUID;
     36 
     37 import com.android.internal.R;
     38 
     39 
     40 /**
     41  * Provides API to the WifiStateMachine for doing read/write access
     42  * to soft access point configuration
     43  */
     44 class WifiApConfigStore {
     45 
     46     private static Context sContext;
     47     private static final String TAG = "WifiApConfigStore";
     48 
     49     private static final String AP_CONFIG_FILE = Environment.getDataDirectory() +
     50         "/misc/wifi/softap.conf";
     51 
     52     private static final int AP_CONFIG_FILE_VERSION = 1;
     53 
     54     private static WifiConfiguration sApConfig = new WifiConfiguration();
     55     private static final Object sApConfigLock = new Object();
     56 
     57     private static FileReadWriteHandler sFileReadWriteHandler;
     58     private static final int READ_AP_CONFIG               = 1;
     59     private static final int WRITE_AP_CONFIG              = 2;
     60 
     61     static void initialize(Context context) {
     62         sContext = context;
     63 
     64         /* File operations happen on a seperate thread */
     65         HandlerThread configThread = new HandlerThread("WifiApConfigStore");
     66         configThread.start();
     67         sFileReadWriteHandler = new FileReadWriteHandler(configThread.getLooper());
     68         Message.obtain(sFileReadWriteHandler, READ_AP_CONFIG).sendToTarget();
     69     }
     70 
     71 
     72     static void setApConfiguration(WifiConfiguration config) {
     73         synchronized (sApConfigLock) {
     74             sApConfig = config;
     75         }
     76         Message.obtain(sFileReadWriteHandler, WRITE_AP_CONFIG, new WifiConfiguration(config))
     77             .sendToTarget();
     78     }
     79 
     80     static WifiConfiguration getApConfiguration() {
     81         synchronized (sApConfigLock) {
     82             return new WifiConfiguration(sApConfig);
     83         }
     84     }
     85 
     86     /**
     87      * File read/write handler
     88      */
     89     private static class FileReadWriteHandler extends Handler {
     90 
     91         public FileReadWriteHandler(android.os.Looper looper) {
     92             super(looper);
     93         }
     94 
     95         @Override
     96         public void handleMessage(Message msg) {
     97             switch (msg.what) {
     98                 case WRITE_AP_CONFIG:
     99                     writeApConfiguration((WifiConfiguration) msg.obj);
    100                     break;
    101                 case READ_AP_CONFIG:
    102                     readApConfiguration();
    103                     break;
    104                 default:
    105                     Log.e(TAG, "Unknown command in FileReadWriteHandler: " + msg);
    106                     break;
    107             }
    108         }
    109 
    110         private static void writeApConfiguration(final WifiConfiguration config) {
    111             DataOutputStream out = null;
    112             try {
    113                 out = new DataOutputStream(new BufferedOutputStream(
    114                             new FileOutputStream(AP_CONFIG_FILE)));
    115 
    116                 out.writeInt(AP_CONFIG_FILE_VERSION);
    117                 out.writeUTF(config.SSID);
    118                 int authType = config.getAuthType();
    119                 out.writeInt(authType);
    120                 if(authType != KeyMgmt.NONE) {
    121                     out.writeUTF(config.preSharedKey);
    122                 }
    123             } catch (IOException e) {
    124                 Log.e(TAG, "Error writing hotspot configuration" + e);
    125             } finally {
    126                 if (out != null) {
    127                     try {
    128                         out.close();
    129                     } catch (IOException e) {}
    130                 }
    131             }
    132         }
    133 
    134         private static void readApConfiguration() {
    135             DataInputStream in = null;
    136             try {
    137                 WifiConfiguration config = new WifiConfiguration();
    138                 in = new DataInputStream(new BufferedInputStream(new FileInputStream(
    139                                 AP_CONFIG_FILE)));
    140 
    141                 int version = in.readInt();
    142                 if (version != 1) {
    143                     Log.e(TAG, "Bad version on hotspot configuration file, set defaults");
    144                     setDefaultApConfiguration();
    145                     return;
    146                 }
    147                 config.SSID = in.readUTF();
    148                 int authType = in.readInt();
    149                 config.allowedKeyManagement.set(authType);
    150                 if (authType != KeyMgmt.NONE) {
    151                     config.preSharedKey = in.readUTF();
    152                 }
    153                 synchronized (sApConfigLock) {
    154                     sApConfig = config;
    155                 }
    156             } catch (IOException ignore) {
    157                 setDefaultApConfiguration();
    158             } finally {
    159                 if (in != null) {
    160                     try {
    161                         in.close();
    162                     } catch (IOException e) {}
    163                 }
    164             }
    165         }
    166 
    167         /* Generate a default WPA2 based configuration with a random password.
    168            We are changing the Wifi Ap configuration storage from secure settings to a
    169            flat file accessible only by the system. A WPA2 based default configuration
    170            will keep the device secure after the update */
    171         private static void setDefaultApConfiguration() {
    172             WifiConfiguration config = new WifiConfiguration();
    173             config.SSID = sContext.getString(R.string.wifi_tether_configure_ssid_default);
    174             config.allowedKeyManagement.set(KeyMgmt.WPA2_PSK);
    175             String randomUUID = UUID.randomUUID().toString();
    176             //first 12 chars from xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx
    177             config.preSharedKey = randomUUID.substring(0, 8) + randomUUID.substring(9,13);
    178             setApConfiguration(config);
    179         }
    180     }
    181 }
    182