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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.net.RouteInfo;
import android.os.Build;
import android.os.Bundle;
import android.os.Parcelable;
import android.util.Log;
import java.io.IOException;
import java.net.Inet4Address;
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.Map;
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();
boolean interrupted = false;
for(InetAddress server : servers) {
if (Thread.currentThread().isInterrupted()) {
interrupted = true;
break;
}
b = queryDNS(host, server);
if (b.containsKey("values")) {
return b;
}
}
if (!b.containsKey("values")) {
Log.d(Config.LOGTAG,(interrupted ? "Thread interrupted during DNS query" :"all dns queries failed") + ". provide fallback A record");
ArrayList<Parcelable> values = new ArrayList<>();
values.add(createNamePortBundle(host, 5222, false));
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) {
if (hasDefaultRoute(linkProperties)) {
servers.addAll(0, getIPv4First(linkProperties.getDnsServers()));
} else {
servers.addAll(getIPv4First(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> getIPv4First(List<InetAddress> in) {
List<InetAddress> out = new ArrayList<>();
for(InetAddress addr : in) {
if (addr instanceof Inet4Address) {
out.add(0, addr);
} else {
out.add(addr);
}
}
return out;
}
@TargetApi(Build.VERSION_CODES.LOLLIPOP)
private static boolean hasDefaultRoute(LinkProperties linkProperties) {
for(RouteInfo route: linkProperties.getRoutes()) {
if (route.isDefaultRoute()) {
return true;
}
}
return false;
}
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;
}
private static class TlsSrv {
private final SRV srv;
private final boolean tls;
public TlsSrv(SRV srv, boolean tls) {
this.srv = srv;
this.tls = tls;
}
}
private static void fillSrvMaps(final String qname, final InetAddress dnsServer, final Map<Integer, List<TlsSrv>> priorities, final Map<String, List<String>> ips4, final Map<String, List<String>> ips6, final boolean tls) throws IOException {
final DNSMessage message = client.query(qname, TYPE.SRV, CLASS.IN, dnsServer.getHostAddress());
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<TlsSrv>());
}
priorities.get(srv.getPriority()).add(new TlsSrv(srv, tls));
}
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() + "]");
}
}
}
}
public static Bundle queryDNS(String host, InetAddress dnsServer) {
Bundle bundle = new Bundle();
try {
client.setTimeout(Config.SOCKET_TIMEOUT * 1000);
final String qname = "_xmpp-client._tcp." + host;
final String tlsQname = "_xmpps-client._tcp." + host;
Log.d(Config.LOGTAG, "using dns server: " + dnsServer.getHostAddress() + " to look up " + host);
final Map<Integer, List<TlsSrv>> priorities = new TreeMap<>();
final Map<String, List<String>> ips4 = new TreeMap<>();
final Map<String, List<String>> ips6 = new TreeMap<>();
fillSrvMaps(qname, dnsServer, priorities, ips4, ips6, false);
fillSrvMaps(tlsQname, dnsServer, priorities, ips4, ips6, true);
final List<TlsSrv> result = new ArrayList<>();
for (final List<TlsSrv> s : priorities.values()) {
result.addAll(s);
}
final 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(), false));
}
} 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(), false));
}
} catch (SocketTimeoutException e) {
Log.d(Config.LOGTAG,"ignoring timeout exception when querying AAAA record on "+dnsServer.getHostAddress());
}
values.add(createNamePortBundle(host, 5222, false));
bundle.putParcelableArrayList("values", values);
return bundle;
}
for (final TlsSrv tlsSrv : result) {
final SRV srv = tlsSrv.srv;
if (ips6.containsKey(srv.getName())) {
values.add(createNamePortBundle(srv.getName(),srv.getPort(),ips6, tlsSrv.tls));
} 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(), tlsSrv.tls));
}
} 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, tlsSrv.tls));
} 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(), tlsSrv.tls));
}
}
values.add(createNamePortBundle(srv.getName(), srv.getPort(), tlsSrv.tls));
}
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, final boolean tls) {
Bundle namePort = new Bundle();
namePort.putString("name", name);
namePort.putBoolean("tls", tls);
namePort.putInt("port", port);
return namePort;
}
private static Bundle createNamePortBundle(String name, int port, Map<String, List<String>> ips, final boolean tls) {
Bundle namePort = new Bundle();
namePort.putString("name", name);
namePort.putBoolean("tls", tls);
namePort.putInt("port", port);
if (ips!=null) {
List<String> ip = ips.get(name);
Collections.shuffle(ip, new Random());
namePort.putString("ip", ip.get(0));
}
return namePort;
}
private static Bundle createNamePortBundle(String name, int port, Data data, final boolean tls) {
Bundle namePort = new Bundle();
namePort.putString("name", name);
namePort.putBoolean("tls", tls);
namePort.putInt("port", port);
if (data instanceof A) {
namePort.putString("ip", data.toString());
} else if (data instanceof AAAA) {
namePort.putString("ip","["+data.toString()+"]");
}
return namePort;
}
public static boolean isIp(final String server) {
return server != null && (
PATTERN_IPV4.matcher(server).matches()
|| PATTERN_IPV6.matcher(server).matches()
|| PATTERN_IPV6_6HEX4DEC.matcher(server).matches()
|| PATTERN_IPV6_HEX4DECCOMPRESSED.matcher(server).matches()
|| PATTERN_IPV6_HEXCOMPRESSED.matcher(server).matches());
}
}
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