1 /*
2  * Copyright (C) 2017 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 package com.android.car.settings.wifi.details;
17 
18 import android.car.drivingstate.CarUxRestrictions;
19 import android.content.Context;
20 import android.net.LinkAddress;
21 import android.net.NetworkUtils;
22 
23 import com.android.car.settings.common.FragmentController;
24 
25 import java.net.Inet4Address;
26 import java.net.InetAddress;
27 import java.net.UnknownHostException;
28 
29 /**
30  * Shows info about Wifi subnet.
31  */
32 public class WifiSubnetPreferenceController extends
33         WifiDetailsBasePreferenceController<WifiDetailsPreference> {
34 
WifiSubnetPreferenceController(Context context, String preferenceKey, FragmentController fragmentController, CarUxRestrictions uxRestrictions)35     public WifiSubnetPreferenceController(Context context, String preferenceKey,
36             FragmentController fragmentController, CarUxRestrictions uxRestrictions) {
37         super(context, preferenceKey, fragmentController, uxRestrictions);
38     }
39 
40     @Override
getPreferenceType()41     protected Class<WifiDetailsPreference> getPreferenceType() {
42         return WifiDetailsPreference.class;
43     }
44 
45     @Override
updateState(WifiDetailsPreference preference)46     protected void updateState(WifiDetailsPreference preference) {
47         String subnet = null;
48 
49         for (LinkAddress addr : getWifiInfoProvider().getLinkProperties().getLinkAddresses()) {
50             if (addr.getAddress() instanceof Inet4Address) {
51                 subnet = ipv4PrefixLengthToSubnetMask(addr.getPrefixLength());
52             }
53         }
54 
55         if (subnet == null) {
56             preference.setVisible(false);
57         } else {
58             preference.setDetailText(subnet);
59             preference.setVisible(true);
60         }
61     }
62 
ipv4PrefixLengthToSubnetMask(int prefixLength)63     private static String ipv4PrefixLengthToSubnetMask(int prefixLength) {
64         try {
65             InetAddress all = InetAddress.getByAddress(
66                     new byte[]{(byte) 255, (byte) 255, (byte) 255, (byte) 255});
67             return NetworkUtils.getNetworkPart(all, prefixLength).getHostAddress();
68         } catch (UnknownHostException e) {
69             return null;
70         }
71     }
72 }
73