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 17 package com.android.settings.network; 18 19 import static android.net.ConnectivityManager.PRIVATE_DNS_MODE_OFF; 20 import static android.net.ConnectivityManager.PRIVATE_DNS_MODE_OPPORTUNISTIC; 21 import static android.net.ConnectivityManager.PRIVATE_DNS_MODE_PROVIDER_HOSTNAME; 22 import static android.provider.Settings.Global.PRIVATE_DNS_DEFAULT_MODE; 23 import static android.provider.Settings.Global.PRIVATE_DNS_MODE; 24 import static android.provider.Settings.Global.PRIVATE_DNS_SPECIFIER; 25 26 import android.content.ContentResolver; 27 import android.content.Context; 28 import android.content.res.Resources; 29 import android.database.ContentObserver; 30 import android.net.ConnectivityManager; 31 import android.net.ConnectivityManager.NetworkCallback; 32 import android.net.LinkProperties; 33 import android.net.Network; 34 import android.net.Uri; 35 import android.os.Handler; 36 import android.os.Looper; 37 import android.os.UserHandle; 38 import android.os.UserManager; 39 import android.provider.Settings; 40 41 import androidx.preference.Preference; 42 import androidx.preference.PreferenceScreen; 43 44 import com.android.internal.util.ArrayUtils; 45 import com.android.settings.R; 46 import com.android.settings.core.BasePreferenceController; 47 import com.android.settings.core.PreferenceControllerMixin; 48 import com.android.settingslib.RestrictedLockUtils.EnforcedAdmin; 49 import com.android.settingslib.RestrictedLockUtilsInternal; 50 import com.android.settingslib.core.lifecycle.LifecycleObserver; 51 import com.android.settingslib.core.lifecycle.events.OnStart; 52 import com.android.settingslib.core.lifecycle.events.OnStop; 53 54 import java.net.InetAddress; 55 import java.util.List; 56 57 public class PrivateDnsPreferenceController extends BasePreferenceController 58 implements PreferenceControllerMixin, LifecycleObserver, OnStart, OnStop { 59 private static final String KEY_PRIVATE_DNS_SETTINGS = "private_dns_settings"; 60 61 private static final Uri[] SETTINGS_URIS = new Uri[]{ 62 Settings.Global.getUriFor(PRIVATE_DNS_MODE), 63 Settings.Global.getUriFor(PRIVATE_DNS_DEFAULT_MODE), 64 Settings.Global.getUriFor(PRIVATE_DNS_SPECIFIER), 65 }; 66 67 private final Handler mHandler; 68 private final ContentObserver mSettingsObserver; 69 private final ConnectivityManager mConnectivityManager; 70 private LinkProperties mLatestLinkProperties; 71 private Preference mPreference; 72 PrivateDnsPreferenceController(Context context)73 public PrivateDnsPreferenceController(Context context) { 74 super(context, KEY_PRIVATE_DNS_SETTINGS); 75 mHandler = new Handler(Looper.getMainLooper()); 76 mSettingsObserver = new PrivateDnsSettingsObserver(mHandler); 77 mConnectivityManager = context.getSystemService(ConnectivityManager.class); 78 } 79 80 @Override getPreferenceKey()81 public String getPreferenceKey() { 82 return KEY_PRIVATE_DNS_SETTINGS; 83 } 84 85 @Override getAvailabilityStatus()86 public int getAvailabilityStatus() { 87 return mContext.getResources().getBoolean(R.bool.config_show_private_dns_settings) 88 ? AVAILABLE 89 : UNSUPPORTED_ON_DEVICE; 90 } 91 92 @Override displayPreference(PreferenceScreen screen)93 public void displayPreference(PreferenceScreen screen) { 94 super.displayPreference(screen); 95 96 mPreference = screen.findPreference(getPreferenceKey()); 97 } 98 99 @Override onStart()100 public void onStart() { 101 for (Uri uri : SETTINGS_URIS) { 102 mContext.getContentResolver().registerContentObserver(uri, false, mSettingsObserver); 103 } 104 final Network defaultNetwork = mConnectivityManager.getActiveNetwork(); 105 if (defaultNetwork != null) { 106 mLatestLinkProperties = mConnectivityManager.getLinkProperties(defaultNetwork); 107 } 108 mConnectivityManager.registerDefaultNetworkCallback(mNetworkCallback, mHandler); 109 } 110 111 @Override onStop()112 public void onStop() { 113 mContext.getContentResolver().unregisterContentObserver(mSettingsObserver); 114 mConnectivityManager.unregisterNetworkCallback(mNetworkCallback); 115 } 116 117 @Override getSummary()118 public CharSequence getSummary() { 119 final Resources res = mContext.getResources(); 120 final ContentResolver cr = mContext.getContentResolver(); 121 final String mode = PrivateDnsModeDialogPreference.getModeFromSettings(cr); 122 final LinkProperties lp = mLatestLinkProperties; 123 final List<InetAddress> dnses = (lp == null) ? null : lp.getValidatedPrivateDnsServers(); 124 final boolean dnsesResolved = !ArrayUtils.isEmpty(dnses); 125 switch (mode) { 126 case PRIVATE_DNS_MODE_OFF: 127 return res.getString(R.string.private_dns_mode_off); 128 case PRIVATE_DNS_MODE_OPPORTUNISTIC: 129 // TODO (b/79122154) : create a string specifically for this, instead of 130 // hijacking a string from notifications. This is necessary at this time 131 // because string freeze is in the past and this string has the right 132 // content at this moment. 133 return dnsesResolved ? res.getString(R.string.switch_on_text) 134 : res.getString(R.string.private_dns_mode_opportunistic); 135 case PRIVATE_DNS_MODE_PROVIDER_HOSTNAME: 136 return dnsesResolved 137 ? PrivateDnsModeDialogPreference.getHostnameFromSettings(cr) 138 : res.getString(R.string.private_dns_mode_provider_failure); 139 } 140 return ""; 141 } 142 143 @Override updateState(Preference preference)144 public void updateState(Preference preference) { 145 super.updateState(preference); 146 preference.setEnabled(!isManagedByAdmin()); 147 } 148 isManagedByAdmin()149 private boolean isManagedByAdmin() { 150 EnforcedAdmin enforcedAdmin = RestrictedLockUtilsInternal.checkIfRestrictionEnforced( 151 mContext, UserManager.DISALLOW_CONFIG_PRIVATE_DNS, UserHandle.myUserId()); 152 return enforcedAdmin != null; 153 } 154 155 private class PrivateDnsSettingsObserver extends ContentObserver { PrivateDnsSettingsObserver(Handler h)156 public PrivateDnsSettingsObserver(Handler h) { 157 super(h); 158 } 159 160 @Override onChange(boolean selfChange)161 public void onChange(boolean selfChange) { 162 if (mPreference != null) { 163 updateState(mPreference); 164 } 165 } 166 } 167 168 private final NetworkCallback mNetworkCallback = new NetworkCallback() { 169 @Override 170 public void onLinkPropertiesChanged(Network network, LinkProperties lp) { 171 mLatestLinkProperties = lp; 172 if (mPreference != null) { 173 updateState(mPreference); 174 } 175 } 176 @Override 177 public void onLost(Network network) { 178 mLatestLinkProperties = null; 179 if (mPreference != null) { 180 updateState(mPreference); 181 } 182 } 183 }; 184 } 185