aboutsummaryrefslogtreecommitdiffstats
path: root/src/main/java/eu/siacs/conversations/utils/DNSHelper.java
blob: 5a47bb3c3e00029fb4d792bff4fab176b130fffc (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
package eu.siacs.conversations.utils;

import de.measite.minidns.Client;
import de.measite.minidns.DNSMessage;
import de.measite.minidns.Record;
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.util.NameUtil;
import eu.siacs.conversations.Config;
import eu.siacs.conversations.xmpp.jid.Jid;

import java.io.IOException;
import java.net.InetAddress;
import java.net.SocketTimeoutException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Random;
import java.util.TreeMap;
import java.util.regex.Pattern;

import android.os.Bundle;
import android.util.Log;

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) throws IOException {
        final String host = jid.getDomainpart();
		String dns[] = client.findDNS();

		if (dns != null) {
			for (String dnsserver : dns) {
				InetAddress ip = InetAddress.getByName(dnsserver);
				Bundle b = queryDNS(host, ip);
				if (b.containsKey("values")) {
					return b;
				}
			}
		}
		return queryDNS(host, InetAddress.getByName("8.8.8.8"));
	}

	public static Bundle queryDNS(String host, InetAddress dnsServer) {
		Bundle bundle = new Bundle();
		try {
			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;
				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()));
				}
				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()));
				}
				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 {
					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()));
					}
				}
				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) {
			e.printStackTrace();
			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) {
		Bundle namePort = new Bundle();
		namePort.putString("name", name);
		namePort.putInt("port", port);
		if (ips!=null) {
			ArrayList<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) {
		Bundle namePort = new Bundle();
		namePort.putString("name", name);
		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()
				|| PATTERN_IPV6.matcher(server).matches()
				|| PATTERN_IPV6_6HEX4DEC.matcher(server).matches()
				|| PATTERN_IPV6_HEX4DECCOMPRESSED.matcher(server).matches()
				|| PATTERN_IPV6_HEXCOMPRESSED.matcher(server).matches();
	}
}