@@ -4,14 +4,18 @@ import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.LineNumberReader;
+import java.lang.reflect.Method;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
+import java.util.ArrayList;
+import java.util.Arrays;
import java.util.HashSet;
import java.util.Random;
+import android.util.Log;
import de.measite.minidns.Record.CLASS;
import de.measite.minidns.Record.TYPE;
@@ -130,6 +134,33 @@ public class Client {
* @return The server array.
*/
public String[] findDNS() {
+ String[] result = findDNSByReflection();
+ if (result != null) {
+ Log.d("minidns/client",
+ "Got DNS servers via reflection: " + Arrays.toString(result));
+ return result;
+ }
+
+ result = findDNSByExec();
+ if (result != null) {
+ Log.d("minidns/client",
+ "Got DNS servers via exec: " + Arrays.toString(result));
+ return result;
+ }
+
+ // fallback for ipv4 and ipv6 connectivity
+ // see https://developers.google.com/speed/public-dns/docs/using
+ Log.d("minidns/client",
+ "No DNS found? Using fallback [8.8.8.8, [2001:4860:4860::8888]]");
+
+ return new String[]{"8.8.8.8", "[2001:4860:4860::8888]"};
+ }
+
+ /**
+ * Try to retrieve the list of dns server by executing getprop.
+ * @return Array of servers, or null on failure.
+ */
+ protected String[] findDNSByExec() {
try {
Process process = Runtime.getRuntime().exec("getprop");
InputStream inputStream = process.getInputStream();
@@ -146,7 +177,19 @@ public class Client {
String value = line.substring(split + 4, line.length() - 1);
if (property.endsWith(".dns") || property.endsWith(".dns1") ||
property.endsWith(".dns2") || property.endsWith(".dns3") ||
- property.endsWith(".dns4")) {
+ property.endsWith(".dns4")) {
+
+ // normalize the address
+
+ InetAddress ip = InetAddress.getByName(value);
+
+ if (ip == null) continue;
+
+ value = ip.getHostAddress();
+
+ if (value == null) continue;
+ if (value.length() == 0) continue;
+
server.add(value);
}
}
@@ -158,4 +201,50 @@ public class Client {
}
return null;
}
+
+ /**
+ * Try to retrieve the list of dns server by calling SystemProperties.
+ * @return Array of servers, or null on failure.
+ */
+ protected String[] findDNSByReflection() {
+ try {
+ Class<?> SystemProperties =
+ Class.forName("android.os.SystemProperties");
+ Method method = SystemProperties.getMethod("get",
+ new Class[] { String.class });
+
+ ArrayList<String> servers = new ArrayList<String>(5);
+
+ for (String propKey : new String[] {
+ "net.dns1", "net.dns2", "net.dns3", "net.dns4"}) {
+
+ String value = (String)method.invoke(null, propKey);
+
+ if (value == null) continue;
+ if (value.length() == 0) continue;
+ if (servers.contains(value)) continue;
+
+ InetAddress ip = InetAddress.getByName(value);
+
+ if (ip == null) continue;
+
+ value = ip.getHostAddress();
+
+ if (value == null) continue;
+ if (value.length() == 0) continue;
+ if (servers.contains(value)) continue;
+
+ servers.add(value);
+ }
+
+ if (servers.size() > 0) {
+ return servers.toArray(new String[servers.size()]);
+ }
+ } catch (Exception e) {
+ // we might trigger some problems this way
+ e.printStackTrace();
+ }
+ return null;
+ }
+
}