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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.Handler;
     23 import android.os.Message;
     24 import android.os.Messenger;
     25 import android.util.Log;
     26 
     27 import com.android.internal.util.AsyncChannel;
     28 import com.android.internal.R;
     29 import com.android.internal.util.State;
     30 import com.android.internal.util.StateMachine;
     31 
     32 import java.io.BufferedInputStream;
     33 import java.io.BufferedOutputStream;
     34 import java.io.DataInputStream;
     35 import java.io.DataOutputStream;
     36 import java.io.FileInputStream;
     37 import java.io.FileOutputStream;
     38 import java.io.IOException;
     39 import java.net.InetAddress;
     40 import java.util.UUID;
     41 
     42 /**
     43  * Provides API to the WifiStateMachine for doing read/write access
     44  * to soft access point configuration
     45  */
     46 class WifiApConfigStore extends StateMachine {
     47 
     48     private Context mContext;
     49     private static final String TAG = "WifiApConfigStore";
     50 
     51     private static final String AP_CONFIG_FILE = Environment.getDataDirectory() +
     52         "/misc/wifi/softap.conf";
     53 
     54     private static final int AP_CONFIG_FILE_VERSION = 1;
     55 
     56     private State mDefaultState = new DefaultState();
     57     private State mInactiveState = new InactiveState();
     58     private State mActiveState = new ActiveState();
     59 
     60     private WifiConfiguration mWifiApConfig = null;
     61     private AsyncChannel mReplyChannel = new AsyncChannel();
     62 
     63     WifiApConfigStore(Context context, Handler target) {
     64         super(TAG, target.getLooper());
     65 
     66         mContext = context;
     67         addState(mDefaultState);
     68             addState(mInactiveState, mDefaultState);
     69             addState(mActiveState, mDefaultState);
     70 
     71         setInitialState(mInactiveState);
     72     }
     73 
     74     public static WifiApConfigStore makeWifiApConfigStore(Context context, Handler target) {
     75         WifiApConfigStore s = new WifiApConfigStore(context, target);
     76         s.start();
     77         return s;
     78     }
     79 
     80     class DefaultState extends State {
     81         public boolean processMessage(Message message) {
     82             switch (message.what) {
     83                 case WifiStateMachine.CMD_SET_AP_CONFIG:
     84                 case WifiStateMachine.CMD_SET_AP_CONFIG_COMPLETED:
     85                     Log.e(TAG, "Unexpected message: " + message);
     86                     break;
     87                 case WifiStateMachine.CMD_REQUEST_AP_CONFIG:
     88                     mReplyChannel.replyToMessage(message,
     89                             WifiStateMachine.CMD_RESPONSE_AP_CONFIG, mWifiApConfig);
     90                     break;
     91                 default:
     92                     Log.e(TAG, "Failed to handle " + message);
     93                     break;
     94             }
     95             return HANDLED;
     96         }
     97     }
     98 
     99     class InactiveState extends State {
    100         public boolean processMessage(Message message) {
    101             switch (message.what) {
    102                 case WifiStateMachine.CMD_SET_AP_CONFIG:
    103                     mWifiApConfig = (WifiConfiguration) message.obj;
    104                     transitionTo(mActiveState);
    105                     break;
    106                 default:
    107                     return NOT_HANDLED;
    108             }
    109             return HANDLED;
    110         }
    111     }
    112 
    113     class ActiveState extends State {
    114         public void enter() {
    115             new Thread(new Runnable() {
    116                 public void run() {
    117                     writeApConfiguration(mWifiApConfig);
    118                     sendMessage(WifiStateMachine.CMD_SET_AP_CONFIG_COMPLETED);
    119                 }
    120             }).start();
    121         }
    122 
    123         public boolean processMessage(Message message) {
    124             switch (message.what) {
    125                 //TODO: have feedback to the user when we do this
    126                 //to indicate the write is currently in progress
    127                 case WifiStateMachine.CMD_SET_AP_CONFIG:
    128                     deferMessage(message);
    129                     break;
    130                 case WifiStateMachine.CMD_SET_AP_CONFIG_COMPLETED:
    131                     transitionTo(mInactiveState);
    132                     break;
    133                 default:
    134                     return NOT_HANDLED;
    135             }
    136             return HANDLED;
    137         }
    138     }
    139 
    140     void loadApConfiguration() {
    141         DataInputStream in = null;
    142         try {
    143             WifiConfiguration config = new WifiConfiguration();
    144             in = new DataInputStream(new BufferedInputStream(new FileInputStream(
    145                             AP_CONFIG_FILE)));
    146 
    147             int version = in.readInt();
    148             if (version != 1) {
    149                 Log.e(TAG, "Bad version on hotspot configuration file, set defaults");
    150                 setDefaultApConfiguration();
    151                 return;
    152             }
    153             config.SSID = in.readUTF();
    154             int authType = in.readInt();
    155             config.allowedKeyManagement.set(authType);
    156             if (authType != KeyMgmt.NONE) {
    157                 config.preSharedKey = in.readUTF();
    158             }
    159             mWifiApConfig = config;
    160         } catch (IOException ignore) {
    161             setDefaultApConfiguration();
    162         } finally {
    163             if (in != null) {
    164                 try {
    165                     in.close();
    166                 } catch (IOException e) {}
    167             }
    168         }
    169     }
    170 
    171     Messenger getMessenger() {
    172         return new Messenger(getHandler());
    173     }
    174 
    175     private void writeApConfiguration(final WifiConfiguration config) {
    176         DataOutputStream out = null;
    177         try {
    178             out = new DataOutputStream(new BufferedOutputStream(
    179                         new FileOutputStream(AP_CONFIG_FILE)));
    180 
    181             out.writeInt(AP_CONFIG_FILE_VERSION);
    182             out.writeUTF(config.SSID);
    183             int authType = config.getAuthType();
    184             out.writeInt(authType);
    185             if(authType != KeyMgmt.NONE) {
    186                 out.writeUTF(config.preSharedKey);
    187             }
    188         } catch (IOException e) {
    189             Log.e(TAG, "Error writing hotspot configuration" + e);
    190         } finally {
    191             if (out != null) {
    192                 try {
    193                     out.close();
    194                 } catch (IOException e) {}
    195             }
    196         }
    197     }
    198 
    199     /* Generate a default WPA2 based configuration with a random password.
    200        We are changing the Wifi Ap configuration storage from secure settings to a
    201        flat file accessible only by the system. A WPA2 based default configuration
    202        will keep the device secure after the update */
    203     private void setDefaultApConfiguration() {
    204         WifiConfiguration config = new WifiConfiguration();
    205         config.SSID = mContext.getString(R.string.wifi_tether_configure_ssid_default);
    206         config.allowedKeyManagement.set(KeyMgmt.WPA2_PSK);
    207         String randomUUID = UUID.randomUUID().toString();
    208         //first 12 chars from xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx
    209         config.preSharedKey = randomUUID.substring(0, 8) + randomUUID.substring(9,13);
    210         sendMessage(WifiStateMachine.CMD_SET_AP_CONFIG, config);
    211     }
    212 }
    213