gt: 		Bundle namePort = new Bundle();
context: package eu.siacs.conversations.utils;
  
  import android.annotation.TargetApi;
  import android.content.Context;
  import android.net.ConnectivityManager;
  import android.net.LinkProperties;
  import android.net.Network;
  import android.os.Build;
  import android.os.Bundle;
  import android.os.Parcelable;
  import android.util.Log;
  
  import java.io.IOException;
  import java.net.InetAddress;
  import java.net.SocketTimeoutException;
  import java.net.UnknownHostException;
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.List;
  import java.util.Random;
  import java.util.TreeMap;
  import java.util.regex.Pattern;
  
  import de.measite.minidns.Client;
  import de.measite.minidns.DNSMessage;
  import de.measite.minidns.Record;
  import de.measite.minidns.Record.CLASS;
  import de.measite.minidns.Record.TYPE;
  import de.measite.minidns.record.A;
  import de.measite.minidns.record.AAAA;
  import de.measite.minidns.record.Data;
  import de.measite.minidns.record.SRV;
  import de.measite.minidns.util.NameUtil;
  import eu.siacs.conversations.Config;
  import eu.siacs.conversations.xmpp.jid.Jid;
  
  public class DNSHelper {
  
  	public static final Pattern PATTERN_IPV4 = Pattern.compile("\\A(25[0-5]|2[0-4]\\d|[0-1]?\\d?\\d)(\\.(25[0-5]|2[0-4]\\d|[0-1]?\\d?\\d)){3}\\z");
  	public static final Pattern PATTERN_IPV6_HEX4DECCOMPRESSED = Pattern.compile("\\A((?:[0-9A-Fa-f]{1,4}(?::[0-9A-Fa-f]{1,4})*)?) ::((?:[0-9A-Fa-f]{1,4}:)*)(25[0-5]|2[0-4]\\d|[0-1]?\\d?\\d)(\\.(25[0-5]|2[0-4]\\d|[0-1]?\\d?\\d)){3}\\z");
  	public static final Pattern PATTERN_IPV6_6HEX4DEC = Pattern.compile("\\A((?:[0-9A-Fa-f]{1,4}:){6,6})(25[0-5]|2[0-4]\\d|[0-1]?\\d?\\d)(\\.(25[0-5]|2[0-4]\\d|[0-1]?\\d?\\d)){3}\\z");
  	public static final Pattern PATTERN_IPV6_HEXCOMPRESSED = Pattern.compile("\\A((?:[0-9A-Fa-f]{1,4}(?::[0-9A-Fa-f]{1,4})*)?)::((?:[0-9A-Fa-f]{1,4}(?::[0-9A-Fa-f]{1,4})*)?)\\z");
  	public static final Pattern PATTERN_IPV6 = Pattern.compile("\\A(?:[0-9a-fA-F]{1,4}:){7}[0-9a-fA-F]{1,4}\\z");
  
  	protected static Client client = new Client();
  
  	public static Bundle getSRVRecord(final Jid jid, Context context) throws IOException {
          final String host = jid.getDomainpart();
  		final List<InetAddress> servers = Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP ? getDnsServers(context) : getDnsServersPreLollipop();
  		Bundle b = new Bundle();
  		for(InetAddress server : servers) {
  			b = queryDNS(host, server);
  			if (b.containsKey("values")) {
  				return b;
  			}
  		}
  		if (!b.containsKey("values")) {
  			Log.d(Config.LOGTAG,"all dns queries failed. provide fallback A record");
  			ArrayList<Parcelable> values = new ArrayList<>();
  			values.add(createNamePortBundle(host,5222));
  			b.putParcelableArrayList("values",values);
  		}
  		return b;
  	}
  
  	@TargetApi(21)
  	private static List<InetAddress> getDnsServers(Context context) {
  		List<InetAddress> servers = new ArrayList<>();
  		ConnectivityManager connectivityManager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
  		Network[] networks = connectivityManager == null ? null : connectivityManager.getAllNetworks();
  		if (networks == null) {
  			return getDnsServersPreLollipop();
  		}
  		for(int i = 0; i < networks.length; ++i) {
  			LinkProperties linkProperties = connectivityManager.getLinkProperties(networks[i]);
  			if (linkProperties != null) {
  				servers.addAll(linkProperties.getDnsServers());
  			}
  		}
  		if (servers.size() > 0) {
  			Log.d(Config.LOGTAG,"used lollipop variant to discover dns servers in "+networks.length+" networks");
  		}
  		return servers.size() > 0 ? servers : getDnsServersPreLollipop();
  	}
  
  	private static List<InetAddress> getDnsServersPreLollipop() {
  		List<InetAddress> servers = new ArrayList<>();
  		String[] dns = client.findDNS();
  		for(int i = 0; i < dns.length; ++i) {
  			try {
  				servers.add(InetAddress.getByName(dns[i]));
  			} catch (UnknownHostException e) {
  				//ignore
  			}
  		}
  		return servers;
  	}
  
  	public static Bundle queryDNS(String host, InetAddress dnsServer) {
  		Bundle bundle = new Bundle();
  		try {
  			client.setTimeout(Config.PING_TIMEOUT * 1000);
  			String qname = "_xmpp-client._tcp." + host;
  			Log.d(Config.LOGTAG, "using dns server: " + dnsServer.getHostAddress() + " to look up " + host);
  			DNSMessage message = client.query(qname, TYPE.SRV, CLASS.IN, dnsServer.getHostAddress());
  
  			TreeMap<Integer, ArrayList<SRV>> priorities = new TreeMap<>();
  			TreeMap<String, ArrayList<String>> ips4 = new TreeMap<>();
  			TreeMap<String, ArrayList<String>> ips6 = new TreeMap<>();
  
  			for (Record[] rrset : new Record[][] { message.getAnswers(), message.getAdditionalResourceRecords() }) {
  				for (Record rr : rrset) {
  					Data d = rr.getPayload();
  					if (d instanceof SRV && NameUtil.idnEquals(qname, rr.getName())) {
  						SRV srv = (SRV) d;
  						if (!priorities.containsKey(srv.getPriority())) {
  							priorities.put(srv.getPriority(),new ArrayList<SRV>());
  						}
  						priorities.get(srv.getPriority()).add(srv);
  					}
  					if (d instanceof A) {
  						A a = (A) d;
  						if (!ips4.containsKey(rr.getName())) {
  							ips4.put(rr.getName(), new ArrayList<String>());
  						}
  						ips4.get(rr.getName()).add(a.toString());
  					}
  					if (d instanceof AAAA) {
  						AAAA aaaa = (AAAA) d;
  						if (!ips6.containsKey(rr.getName())) {
  							ips6.put(rr.getName(), new ArrayList<String>());
  						}
  						ips6.get(rr.getName()).add("[" + aaaa.toString() + "]");
  					}
  				}
  			}
  
  			ArrayList<SRV> result = new ArrayList<>();
  			for (ArrayList<SRV> s : priorities.values()) {
  				result.addAll(s);
  			}
  
  			ArrayList<Bundle> values = new ArrayList<>();
  			if (result.size() == 0) {
  				DNSMessage response;
  				try {
  					response = client.query(host, TYPE.A, CLASS.IN, dnsServer.getHostAddress());
  					for (int i = 0; i < response.getAnswers().length; ++i) {
  						values.add(createNamePortBundle(host, 5222, response.getAnswers()[i].getPayload()));
  					}
  				} catch (SocketTimeoutException e) {
  					Log.d(Config.LOGTAG,"ignoring timeout exception when querying A record on "+dnsServer.getHostAddress());
  				}
  				try {
  					response = client.query(host, TYPE.AAAA, CLASS.IN, dnsServer.getHostAddress());
  					for (int i = 0; i < response.getAnswers().length; ++i) {
  						values.add(createNamePortBundle(host, 5222, response.getAnswers()[i].getPayload()));
  					}
  				} catch (SocketTimeoutException e) {
  					Log.d(Config.LOGTAG,"ignoring timeout exception when querying AAAA record on "+dnsServer.getHostAddress());
  				}
  				values.add(createNamePortBundle(host,5222));
  				bundle.putParcelableArrayList("values", values);
  				return bundle;
  			}
  			for (SRV srv : result) {
  				if (ips6.containsKey(srv.getName())) {
  					values.add(createNamePortBundle(srv.getName(),srv.getPort(),ips6));
  				} else {
  					try {
  						DNSMessage response = client.query(srv.getName(), TYPE.AAAA, CLASS.IN, dnsServer.getHostAddress());
  						for (int i = 0; i < response.getAnswers().length; ++i) {
  							values.add(createNamePortBundle(srv.getName(), srv.getPort(), response.getAnswers()[i].getPayload()));
  						}
  					} catch (SocketTimeoutException e) {
  						Log.d(Config.LOGTAG,"ignoring timeout exception when querying AAAA record on "+dnsServer.getHostAddress());
  					}
  				}
  				if (ips4.containsKey(srv.getName())) {
  					values.add(createNamePortBundle(srv.getName(),srv.getPort(),ips4));
  				} else {
  					DNSMessage response = client.query(srv.getName(), TYPE.A, CLASS.IN, dnsServer.getHostAddress());
  					for(int i = 0; i < response.getAnswers().length; ++i) {
  						values.add(createNamePortBundle(srv.getName(),srv.getPort(),response.getAnswers()[i].getPayload()));
  					}
  				}
  				values.add(createNamePortBundle(srv.getName(), srv.getPort()));
  			}
  			bundle.putParcelableArrayList("values", values);
  		} catch (SocketTimeoutException e) {
  			bundle.putString("error", "timeout");
  		} catch (Exception e) {
  			bundle.putString("error", "unhandled");
  		}
  		return bundle;
  	}
  
  	private static Bundle createNamePortBundle(String name, int port) {
  		Bundle namePort = new Bundle();
  		namePort.putString("name", name);
  		namePort.putInt("port", port);
  		return namePort;
  	}
  
  	private static Bundle createNamePortBundle(String name, int port, TreeMap<String, ArrayList<String>> ips) {
  