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.Map; 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(); protected static Context context; public static Bundle getSRVRecord(final Jid jid, Context context) throws IOException { DNSHelper.context = context; final String host = jid.getDomainpart(); final List 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 values = new ArrayList<>(); values.add(createNamePortBundle(host, 5222, false)); b.putParcelableArrayList("values",values); } return b; } @TargetApi(21) private static List getDnsServers(Context context) { List 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 getIPv4First(List in) { List 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 getDnsServersPreLollipop() { List 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> priorities, final Map> ips4, final Map> 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()); } 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()); } 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()); } 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> priorities = new TreeMap<>(); final Map> ips4 = new TreeMap<>(); final Map> ips6 = new TreeMap<>(); fillSrvMaps(qname, dnsServer, priorities, ips4, ips6, false); fillSrvMaps(tlsQname, dnsServer, priorities, ips4, ips6, true); final List result = new ArrayList<>(); for (final List s : priorities.values()) { result.addAll(s); } final ArrayList 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> ips, final boolean tls) { Bundle namePort = new Bundle(); namePort.putString("name", name); namePort.putBoolean("tls", tls); namePort.putInt("port", port); if (ips!=null) { List 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()); } }