/* * Copyright (C) 2017 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.settings.network; import static android.net.ConnectivityManager.PRIVATE_DNS_DEFAULT_MODE_FALLBACK; import static android.net.ConnectivityManager.PRIVATE_DNS_MODE_OFF; import static android.net.ConnectivityManager.PRIVATE_DNS_MODE_OPPORTUNISTIC; import static android.net.ConnectivityManager.PRIVATE_DNS_MODE_PROVIDER_HOSTNAME; import static android.system.OsConstants.AF_INET; import static android.system.OsConstants.AF_INET6; import android.app.AlertDialog; import android.content.ActivityNotFoundException; import android.content.ContentResolver; import android.content.Context; import android.content.DialogInterface; import android.content.Intent; import android.provider.Settings; import android.support.annotation.VisibleForTesting; import android.system.Os; import android.text.Editable; import android.text.TextWatcher; import android.text.method.LinkMovementMethod; import android.util.AttributeSet; import android.util.Log; import android.view.View; import android.widget.Button; import android.widget.EditText; import android.widget.RadioGroup; import android.widget.TextView; import com.android.internal.logging.nano.MetricsProto; import com.android.settings.R; import com.android.settings.overlay.FeatureFactory; import com.android.settings.utils.AnnotationSpan; import com.android.settingslib.CustomDialogPreference; import com.android.settingslib.HelpUtils; import java.net.InetAddress; import java.util.HashMap; import java.util.Map; /** * Dialog to set the Private DNS */ public class PrivateDnsModeDialogPreference extends CustomDialogPreference implements DialogInterface.OnClickListener, RadioGroup.OnCheckedChangeListener, TextWatcher { public static final String ANNOTATION_URL = "url"; private static final String TAG = "PrivateDnsModeDialog"; // DNS_MODE -> RadioButton id private static final Map<String, Integer> PRIVATE_DNS_MAP; static { PRIVATE_DNS_MAP = new HashMap<>(); PRIVATE_DNS_MAP.put(PRIVATE_DNS_MODE_OFF, R.id.private_dns_mode_off); PRIVATE_DNS_MAP.put(PRIVATE_DNS_MODE_OPPORTUNISTIC, R.id.private_dns_mode_opportunistic); PRIVATE_DNS_MAP.put(PRIVATE_DNS_MODE_PROVIDER_HOSTNAME, R.id.private_dns_mode_provider); } private static final int[] ADDRESS_FAMILIES = new int[]{AF_INET, AF_INET6}; @VisibleForTesting static final String MODE_KEY = Settings.Global.PRIVATE_DNS_MODE; @VisibleForTesting static final String HOSTNAME_KEY = Settings.Global.PRIVATE_DNS_SPECIFIER; public static String getModeFromSettings(ContentResolver cr) { String mode = Settings.Global.getString(cr, MODE_KEY); if (!PRIVATE_DNS_MAP.containsKey(mode)) { mode = Settings.Global.getString(cr, Settings.Global.PRIVATE_DNS_DEFAULT_MODE); } return PRIVATE_DNS_MAP.containsKey(mode) ? mode : PRIVATE_DNS_DEFAULT_MODE_FALLBACK; } public static String getHostnameFromSettings(ContentResolver cr) { return Settings.Global.getString(cr, HOSTNAME_KEY); } @VisibleForTesting EditText mEditText; @VisibleForTesting RadioGroup mRadioGroup; @VisibleForTesting String mMode; public PrivateDnsModeDialogPreference(Context context) { super(context); } public PrivateDnsModeDialogPreference(Context context, AttributeSet attrs) { super(context, attrs); } public PrivateDnsModeDialogPreference(Context context, AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr); } public PrivateDnsModeDialogPreference(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) { super(context, attrs, defStyleAttr, defStyleRes); } private final AnnotationSpan.LinkInfo mUrlLinkInfo = new AnnotationSpan.LinkInfo( ANNOTATION_URL, (widget) -> { final Context context = widget.getContext(); final Intent intent = HelpUtils.getHelpIntent(context, context.getString(R.string.help_uri_private_dns), context.getClass().getName()); if (intent != null) { try { widget.startActivityForResult(intent, 0); } catch (ActivityNotFoundException e) { Log.w(TAG, "Activity was not found for intent, " + intent.toString()); } } }); @Override protected void onBindDialogView(View view) { final Context context = getContext(); final ContentResolver contentResolver = context.getContentResolver(); mMode = getModeFromSettings(context.getContentResolver()); mEditText = view.findViewById(R.id.private_dns_mode_provider_hostname); mEditText.addTextChangedListener(this); mEditText.setText(getHostnameFromSettings(contentResolver)); mRadioGroup = view.findViewById(R.id.private_dns_radio_group); mRadioGroup.setOnCheckedChangeListener(this); mRadioGroup.check(PRIVATE_DNS_MAP.getOrDefault(mMode, R.id.private_dns_mode_opportunistic)); final TextView helpTextView = view.findViewById(R.id.private_dns_help_info); helpTextView.setMovementMethod(LinkMovementMethod.getInstance()); final Intent helpIntent = HelpUtils.getHelpIntent(context, context.getString(R.string.help_uri_private_dns), context.getClass().getName()); final AnnotationSpan.LinkInfo linkInfo = new AnnotationSpan.LinkInfo(context, ANNOTATION_URL, helpIntent); if (linkInfo.isActionable()) { helpTextView.setText(AnnotationSpan.linkify( context.getText(R.string.private_dns_help_message), linkInfo)); } } @Override public void onClick(DialogInterface dialog, int which) { if (which == DialogInterface.BUTTON_POSITIVE) { final Context context = getContext(); if (mMode.equals(PRIVATE_DNS_MODE_PROVIDER_HOSTNAME)) { // Only clickable if hostname is valid, so we could save it safely Settings.Global.putString(context.getContentResolver(), HOSTNAME_KEY, mEditText.getText().toString()); } FeatureFactory.getFactory(context).getMetricsFeatureProvider().action(context, MetricsProto.MetricsEvent.ACTION_PRIVATE_DNS_MODE, mMode); Settings.Global.putString(context.getContentResolver(), MODE_KEY, mMode); } } @Override public void onCheckedChanged(RadioGroup group, int checkedId) { switch (checkedId) { case R.id.private_dns_mode_off: mMode = PRIVATE_DNS_MODE_OFF; break; case R.id.private_dns_mode_opportunistic: mMode = PRIVATE_DNS_MODE_OPPORTUNISTIC; break; case R.id.private_dns_mode_provider: mMode = PRIVATE_DNS_MODE_PROVIDER_HOSTNAME; break; } updateDialogInfo(); } @Override public void beforeTextChanged(CharSequence s, int start, int count, int after) { } @Override public void onTextChanged(CharSequence s, int start, int before, int count) { } @Override public void afterTextChanged(Editable s) { updateDialogInfo(); } private boolean isWeaklyValidatedHostname(String hostname) { // TODO(b/34953048): Use a validation method that permits more accurate, // but still inexpensive, checking of likely valid DNS hostnames. final String WEAK_HOSTNAME_REGEX = "^[a-zA-Z0-9_.-]+$"; if (!hostname.matches(WEAK_HOSTNAME_REGEX)) { return false; } for (int address_family : ADDRESS_FAMILIES) { if (Os.inet_pton(address_family, hostname) != null) { return false; } } return true; } private Button getSaveButton() { final AlertDialog dialog = (AlertDialog) getDialog(); if (dialog == null) { return null; } return dialog.getButton(DialogInterface.BUTTON_POSITIVE); } private void updateDialogInfo() { final boolean modeProvider = PRIVATE_DNS_MODE_PROVIDER_HOSTNAME.equals(mMode); if (mEditText != null) { mEditText.setEnabled(modeProvider); } final Button saveButton = getSaveButton(); if (saveButton != null) { saveButton.setEnabled(modeProvider ? isWeaklyValidatedHostname(mEditText.getText().toString()) : true); } } }