DNS: add Use System DNS as upstream DNS. close #113

app/src/main/AndroidManifest.xml

@@ -4,6 +4,7 @@
 
     <uses-permission android:name="android.permission.INTERNET"/>
     <uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED"/>
+    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
     <uses-permission android:name="android.permission.EXPAND_STATUS_BAR"/>
     <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"
                      android:maxSdkVersion="18"/>

app/src/main/java/org/itxtech/daedalus/Daedalus.java

@@ -18,10 +18,7 @@ import com.google.gson.JsonParseException;
 import com.google.gson.stream.JsonReader;
 import org.itxtech.daedalus.activity.MainActivity;
 import org.itxtech.daedalus.service.DaedalusVpnService;
-import org.itxtech.daedalus.util.Configurations;
+import org.itxtech.daedalus.util.*;
-import org.itxtech.daedalus.util.Logger;
-import org.itxtech.daedalus.util.Rule;
-import org.itxtech.daedalus.util.RuleResolver;
 import org.itxtech.daedalus.util.server.DNSServer;
 import org.itxtech.daedalus.util.server.DNSServerHelper;
 
@@ -217,6 +214,17 @@ public class Daedalus extends Application {
     public static void activateService(Context context) {
         DaedalusVpnService.primaryServer = DNSServerHelper.getAddressById(DNSServerHelper.getPrimary());
         DaedalusVpnService.secondaryServer = DNSServerHelper.getAddressById(DNSServerHelper.getSecondary());
+        if (getPrefs().getBoolean("settings_use_system_dns", false)) {
+            String[] servers = DnsServersDetector.getServers(context);
+            if (servers != null) {
+                if (servers.length >= 2) {
+                    DaedalusVpnService.primaryServer = servers[0];
+                    DaedalusVpnService.secondaryServer = servers[1];
+                } else {
+                    DaedalusVpnService.primaryServer = DaedalusVpnService.secondaryServer = servers[0];
+                }
+            }
+        }
         if (getInstance().prefs.getBoolean("settings_foreground", false)
                 && Build.VERSION.SDK_INT > Build.VERSION_CODES.O) {
             Logger.info("Starting foreground service");

app/src/main/java/org/itxtech/daedalus/fragment/GlobalConfigFragment.java

@@ -9,6 +9,8 @@ import org.itxtech.daedalus.activity.AppFilterActivity;
 import org.itxtech.daedalus.activity.MainActivity;
 import org.itxtech.daedalus.util.server.DNSServerHelper;
 
+import java.util.ArrayList;
+
 /**
  * Daedalus Project
  *
@@ -31,23 +33,21 @@ public class GlobalConfigFragment extends PreferenceFragmentCompat {
 
         addPreferencesFromResource(R.xml.perf_settings);
 
-        ListPreference primaryServer = findPreference("primary_server");
+        boolean visible = !Daedalus.getPrefs().getBoolean("settings_use_system_dns", false);
-        primaryServer.setEntries(DNSServerHelper.getNames(Daedalus.getInstance()));
+        for (String k : new ArrayList<String>() {{
-        primaryServer.setEntryValues(DNSServerHelper.getIds());
+            add("primary_server");
-        primaryServer.setSummary(DNSServerHelper.getDescription(primaryServer.getValue(), Daedalus.getInstance()));
+            add("secondary_server");
-        primaryServer.setOnPreferenceChangeListener((preference, newValue) -> {
+        }}) {
-            preference.setSummary(DNSServerHelper.getDescription((String) newValue, Daedalus.getInstance()));
+            ListPreference listPref = findPreference(k);
-            return true;
+            listPref.setVisible(visible);
-        });
+            listPref.setEntries(DNSServerHelper.getNames(Daedalus.getInstance()));
-
+            listPref.setEntryValues(DNSServerHelper.getIds());
-        ListPreference secondaryServer = findPreference("secondary_server");
+            listPref.setSummary(DNSServerHelper.getDescription(listPref.getValue(), Daedalus.getInstance()));
-        secondaryServer.setEntries(DNSServerHelper.getNames(Daedalus.getInstance()));
+            listPref.setOnPreferenceChangeListener((preference, newValue) -> {
-        secondaryServer.setEntryValues(DNSServerHelper.getIds());
+                preference.setSummary(DNSServerHelper.getDescription((String) newValue, Daedalus.getInstance()));
-        secondaryServer.setSummary(DNSServerHelper.getDescription(secondaryServer.getValue(), Daedalus.getInstance()));
+                return true;
-        secondaryServer.setOnPreferenceChangeListener((preference, newValue) -> {
+            });
-            preference.setSummary(DNSServerHelper.getDescription((String) newValue, Daedalus.getInstance()));
+        }
-            return true;
-        });
 
         EditTextPreference testDNSServers = findPreference("dns_test_servers");
         testDNSServers.setSummary(testDNSServers.getText());
@@ -110,6 +110,13 @@ public class GlobalConfigFragment extends PreferenceFragmentCompat {
 
         updateOptions(advanced.isChecked(), "settings_advanced");
         updateOptions(appFilter.isChecked(), "settings_app_filter");
+
+        findPreference("settings_use_system_dns").setOnPreferenceChangeListener((preference, newValue) -> {
+            boolean vis = !(boolean) newValue;
+            findPreference("primary_server").setVisible(vis);
+            findPreference("secondary_server").setVisible(vis);
+            return true;
+        });
     }
 
     private void updateOptions(boolean checked, String pref) {

app/src/main/java/org/itxtech/daedalus/service/DaedalusVpnService.java

@@ -346,7 +346,7 @@ public class DaedalusVpnService extends VpnService implements Runnable {
         if (time - lastUpdate >= 1000) {
             lastUpdate = time;
             if (notification != null) {
-                notification.setContentTitle(getResources().getString(R.string.notice_queries) + " " + String.valueOf(provider.getDnsQueryTimes()));
+                notification.setContentTitle(getResources().getString(R.string.notice_queries) + " " + provider.getDnsQueryTimes());
                 NotificationManager manager = (NotificationManager) this.getSystemService(Context.NOTIFICATION_SERVICE);
                 manager.notify(NOTIFICATION_ACTIVATED, notification.build());
             }
@@ -358,11 +358,8 @@ public class DaedalusVpnService extends VpnService implements Runnable {
         public VpnNetworkException(String s) {
             super(s);
         }
-
         public VpnNetworkException(String s, Throwable t) {
             super(s, t);
         }
-
     }
-
 }

app/src/main/java/org/itxtech/daedalus/util/DnsServersDetector.java

@@ -0,0 +1,166 @@
+package org.itxtech.daedalus.util;
+
+import android.content.Context;
+import android.net.*;
+import android.os.Build;
+
+import java.io.BufferedReader;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.io.LineNumberReader;
+import java.lang.reflect.Method;
+import java.net.InetAddress;
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+
+/**
+ * Daedalus Project
+ *
+ * @author iTX Technologies
+ * @link https://itxtech.org
+ * <p>
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ */
+public class DnsServersDetector {
+    //https://stackoverflow.com/a/48973823
+    private static final String METHOD_EXEC_PROP_DELIM = "]: [";
+
+    public static String[] getServers(Context context) {
+        String[] result;
+        result = getServersMethodSystemProperties();
+        if (result != null && result.length > 0) {
+            return result;
+        }
+        result = getServersMethodConnectivityManager(context);
+        if (result != null && result.length > 0) {
+            return result;
+        }
+        result = getServersMethodExec();
+        if (result != null && result.length > 0) {
+            return result;
+        }
+        return null;
+    }
+
+    private static String[] getServersMethodConnectivityManager(Context context) {
+        ArrayList<String> priorityServersArrayList = new ArrayList<>();
+        ArrayList<String> serversArrayList = new ArrayList<>();
+        ConnectivityManager connectivityManager =
+                (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
+        if (connectivityManager != null) {
+            for (Network network : connectivityManager.getAllNetworks()) {
+                NetworkInfo networkInfo = connectivityManager.getNetworkInfo(network);
+                if (networkInfo.isConnected()) {
+                    LinkProperties linkProperties = connectivityManager.getLinkProperties(network);
+                    List<InetAddress> dnsServersList = linkProperties.getDnsServers();
+                    if (linkPropertiesHasDefaultRoute(linkProperties)) {
+                        for (InetAddress element : dnsServersList) {
+                            String dnsHost = element.getHostAddress();
+                            priorityServersArrayList.add(dnsHost);
+                        }
+                    } else {
+                        for (InetAddress element : dnsServersList) {
+                            String dnsHost = element.getHostAddress();
+                            serversArrayList.add(dnsHost);
+                        }
+                    }
+                }
+            }
+        }
+        if (priorityServersArrayList.isEmpty()) {
+            priorityServersArrayList.addAll(serversArrayList);
+        }
+        if (priorityServersArrayList.size() > 0) {
+            return priorityServersArrayList.toArray(new String[0]);
+        }
+        return null;
+    }
+
+    private static String[] getServersMethodSystemProperties() {
+        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.O) {
+            final String re1 = "^\\d+(\\.\\d+){3}$";
+            final String re2 = "^[0-9a-f]+(:[0-9a-f]*)+:[0-9a-f]+$";
+            ArrayList<String> serversArrayList = new ArrayList<>();
+            try {
+                Class SystemProperties = Class.forName("android.os.SystemProperties");
+                Method method = SystemProperties.getMethod("get", new Class[]{String.class});
+                final String[] netdns = new String[]{"net.dns1", "net.dns2", "net.dns3", "net.dns4"};
+                for (int i = 0; i < netdns.length; i++) {
+                    Object[] args = new Object[]{netdns[i]};
+                    String v = (String) method.invoke(null, args);
+                    if (v != null && (v.matches(re1) || v.matches(re2)) && !serversArrayList.contains(v)) {
+                        serversArrayList.add(v);
+                    }
+                }
+                if (serversArrayList.size() > 0) {
+                    return serversArrayList.toArray(new String[0]);
+                }
+
+            } catch (Exception ex) {
+                Logger.logException(ex);
+            }
+        }
+        return null;
+    }
+
+    private static String[] getServersMethodExec() {
+        try {
+            Process process = Runtime.getRuntime().exec("getprop");
+            InputStream inputStream = process.getInputStream();
+            LineNumberReader lineNumberReader = new LineNumberReader(new InputStreamReader(inputStream));
+            Set<String> serversSet = methodExecParseProps(lineNumberReader);
+            if (serversSet.size() > 0) {
+                return serversSet.toArray(new String[0]);
+            }
+        } catch (Exception ex) {
+            Logger.logException(ex);
+        }
+        return null;
+    }
+
+    private static Set<String> methodExecParseProps(BufferedReader lineNumberReader) throws Exception {
+        String line;
+        Set<String> serversSet = new HashSet<String>(10);
+        while ((line = lineNumberReader.readLine()) != null) {
+            int split = line.indexOf(METHOD_EXEC_PROP_DELIM);
+            if (split == -1) {
+                continue;
+            }
+            String property = line.substring(1, split);
+            int valueStart = split + METHOD_EXEC_PROP_DELIM.length();
+            int valueEnd = line.length() - 1;
+            if (valueEnd < valueStart) {
+                continue;
+            }
+            String value = line.substring(valueStart, valueEnd);
+            if (value.isEmpty()) {
+                continue;
+            }
+            if (property.endsWith(".dns") || property.endsWith(".dns1") ||
+                    property.endsWith(".dns2") || property.endsWith(".dns3") ||
+                    property.endsWith(".dns4")) {
+                InetAddress ip = InetAddress.getByName(value);
+                if (ip == null) continue;
+                value = ip.getHostAddress();
+                if (value == null) continue;
+                if (value.length() == 0) continue;
+                serversSet.add(value);
+            }
+        }
+        return serversSet;
+    }
+
+    private static boolean linkPropertiesHasDefaultRoute(LinkProperties linkProperties) {
+        for (RouteInfo route : linkProperties.getRoutes()) {
+            if (route.isDefaultRoute()) {
+                return true;
+            }
+        }
+        return false;
+    }
+}

app/src/main/res/values-zh-rCN/strings.xml

@@ -67,6 +67,7 @@
     <string name="settings_dark_theme">使用暗主题</string>
     <string name="settings_dns_query_method">DNS 查询方式</string>
     <string name="settings_foreground">运行前台服务</string>
+    <string name="settings_use_system_dns">使用系統DNS作為上游DNS</string>
 
     <string name="settings_rule_name">规则名称</string>
     <string name="settings_rule_type">规则类型</string>

app/src/main/res/values/strings.xml

@@ -66,6 +66,7 @@
     <string name="settings_dark_theme">Use Dark Theme</string>
     <string name="settings_dns_query_method">DNS Query Method</string>
     <string name="settings_foreground">Run service in Foreground</string>
+    <string name="settings_use_system_dns">Use System DNS as upstream DNS</string>
 
     <string name="settings_dns_tcp">TCP</string>
     <string name="settings_dns_udp">UDP</string>

app/src/main/res/xml/perf_settings.xml

@@ -6,12 +6,15 @@
             android:key="settingsServer"
             android:title="@string/settings_server">
 
+        <SwitchPreference
+                android:key="settings_use_system_dns"
+                android:title="@string/settings_use_system_dns"
+                android:defaultValue="false"/>
         <ListPreference
                 android:key="primary_server"
                 android:title="@string/primary_server"
                 android:defaultValue="0">
         </ListPreference>
-
         <ListPreference
                 android:key="secondary_server"
                 android:title="@string/secondary_server"