diff options
Diffstat (limited to 'src/main/java/eu/siacs/conversations/utils/DNSHelper.java')
| -rw-r--r-- | src/main/java/eu/siacs/conversations/utils/DNSHelper.java | 323 |
1 files changed, 252 insertions, 71 deletions
diff --git a/src/main/java/eu/siacs/conversations/utils/DNSHelper.java b/src/main/java/eu/siacs/conversations/utils/DNSHelper.java index 79a8c854..58d53216 100644 --- a/src/main/java/eu/siacs/conversations/utils/DNSHelper.java +++ b/src/main/java/eu/siacs/conversations/utils/DNSHelper.java @@ -1,12 +1,39 @@ 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.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.CLASS; import de.measite.minidns.record.SRV; +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 java.io.IOException; @@ -21,83 +48,237 @@ import eu.siacs.conversations.Config; import eu.siacs.conversations.xmpp.jid.Jid; public class DNSHelper { - private static final String CLIENT_SRV_PREFIX = "_xmpp-client._tcp."; - private 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"); - private 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"); - private 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"); - private 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"); - private static final Pattern PATTERN_IPV6 = Pattern.compile("\\A(?:[0-9a-fA-F]{1,4}:){7}[0-9a-fA-F]{1,4}\\z"); + + 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(); - /** - * Queries the SRV record for the server JID. - * This method uses all available Domain Name Servers. - * @param jid the server JID - * @return TreeSet with SrvRecords. If no SRV record is found for JID an empty TreeSet is returned. - */ - public static final TreeSet<SrvRecord> querySrvRecord(Jid jid) { - String host = jid.getDomainpart(); - String dns[] = client.findDNS(); - TreeSet<SrvRecord> result = new TreeSet<>(); - - if (dns != null) { - for (String dnsserver : dns) { - result = querySrvRecord(host, dnsserver); - if (!result.isEmpty()) { - break; - } - } - } - - return result; - } - - /** - * Queries the SRV record for an host from the given Domain Name Server. - * @param host the host to query for - * @param dnsserver the DNS to query on - * @return TreeSet with SrvRecords. - */ - private static final TreeSet<SrvRecord> querySrvRecord(String host, String dnsserver) { - TreeSet<SrvRecord> result = new TreeSet<>(); - try { - InetAddress dnsServerAddress = InetAddress.getByName(dnsserver); - String qname = CLIENT_SRV_PREFIX + host; - DNSMessage message = client.query(qname, TYPE.SRV, CLASS.IN, dnsServerAddress.getHostAddress()); - Record[] rrset = message.getAnswers(); - for (Record rr : rrset) { - Data d = rr.getPayload(); - if (d instanceof SRV && NameUtil.idnEquals(qname, rr.getName())) { - SRV srv = (SRV) d; - SrvRecord srvRecord = new SrvRecord(srv.getPriority(), srv.getName(), srv.getPort()); - result.add(srvRecord); - } - } - } catch (IOException e) { - Logging.d("dns", "Error while retrieving SRV record for '" + host + "' from DNS '" + dnsserver + "': " + e.getMessage()); - } - return result; - } - - /** - * Checks whether the given server is an IP address or not. - * The following patterns are treated as valid IP addresses: - * <ul> - * <li>{@link #PATTERN_IPV4}</li> - * <li>{@link #PATTERN_IPV6}</li> - * <li>{@link #PATTERN_IPV6_6HEX4DEC}</li> - * <li>{@link #PATTERN_IPV6_HEX4DECCOMPRESSED}</li> - * <li>{@link #PATTERN_IPV6_HEXCOMPRESSED}</li> - * </ul> - * @param server the string to check - * @return <code>true</code> if one of the patterns is matched <code>false</code> otherwise - */ + 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, 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, linkProperties.getDnsServers()); + } else { + 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(); + } + + @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.PING_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 PATTERN_IPV4.matcher(server).matches() + 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(); + || PATTERN_IPV6_HEXCOMPRESSED.matcher(server).matches()); } } |