1package eu.siacs.conversations.utils;
2
3import de.measite.minidns.Client;
4import de.measite.minidns.DNSMessage;
5import de.measite.minidns.Record;
6import de.measite.minidns.Record.TYPE;
7import de.measite.minidns.Record.CLASS;
8import de.measite.minidns.record.SRV;
9import de.measite.minidns.record.A;
10import de.measite.minidns.record.AAAA;
11import de.measite.minidns.record.Data;
12import de.measite.minidns.util.NameUtil;
13import eu.siacs.conversations.Config;
14import eu.siacs.conversations.xmpp.jid.Jid;
15
16import java.io.IOException;
17import java.net.InetAddress;
18import java.net.SocketTimeoutException;
19import java.util.ArrayList;
20import java.util.Collections;
21import java.util.Random;
22import java.util.TreeMap;
23
24import android.os.Bundle;
25import android.util.Log;
26
27public class DNSHelper {
28 protected static Client client = new Client();
29
30 public static Bundle getSRVRecord(final Jid jid) throws IOException {
31 final String host = jid.getDomainpart();
32 String dns[] = client.findDNS();
33
34 if (dns != null) {
35 for (String dnsserver : dns) {
36 InetAddress ip = InetAddress.getByName(dnsserver);
37 Bundle b = queryDNS(host, ip);
38 if (b.containsKey("values")) {
39 return b;
40 }
41 }
42 }
43 return queryDNS(host, InetAddress.getByName("8.8.8.8"));
44 }
45
46 public static Bundle queryDNS(String host, InetAddress dnsServer) {
47 Bundle bundle = new Bundle();
48 try {
49 String qname = "_xmpp-client._tcp." + host;
50 Log.d(Config.LOGTAG, "using dns server: " + dnsServer.getHostAddress() + " to look up " + host);
51 DNSMessage message = client.query(qname, TYPE.SRV, CLASS.IN, dnsServer.getHostAddress());
52
53 TreeMap<Integer, ArrayList<SRV>> priorities = new TreeMap<>();
54 TreeMap<String, ArrayList<String>> ips4 = new TreeMap<>();
55 TreeMap<String, ArrayList<String>> ips6 = new TreeMap<>();
56
57 for (Record[] rrset : new Record[][] { message.getAnswers(), message.getAdditionalResourceRecords() }) {
58 for (Record rr : rrset) {
59 Data d = rr.getPayload();
60 if (d instanceof SRV && NameUtil.idnEquals(qname, rr.getName())) {
61 SRV srv = (SRV) d;
62 if (!priorities.containsKey(srv.getPriority())) {
63 priorities.put(srv.getPriority(),new ArrayList<SRV>());
64 }
65 priorities.get(srv.getPriority()).add(srv);
66 }
67 if (d instanceof A) {
68 A a = (A) d;
69 if (!ips4.containsKey(rr.getName())) {
70 ips4.put(rr.getName(), new ArrayList<String>());
71 }
72 ips4.get(rr.getName()).add(a.toString());
73 }
74 if (d instanceof AAAA) {
75 AAAA aaaa = (AAAA) d;
76 if (!ips6.containsKey(rr.getName())) {
77 ips6.put(rr.getName(), new ArrayList<String>());
78 }
79 ips6.get(rr.getName()).add("[" + aaaa.toString() + "]");
80 }
81 }
82 }
83
84 ArrayList<SRV> result = new ArrayList<>();
85 for (ArrayList<SRV> s : priorities.values()) {
86 result.addAll(s);
87 }
88
89 ArrayList<Bundle> values = new ArrayList<>();
90 if (result.size() == 0) {
91 DNSMessage response;
92 response = client.query(host, TYPE.A, CLASS.IN, dnsServer.getHostAddress());
93 for(int i = 0; i < response.getAnswers().length; ++i) {
94 values.add(createNamePortBundle(host,5222,response.getAnswers()[i].getPayload()));
95 }
96 response = client.query(host, TYPE.AAAA, CLASS.IN, dnsServer.getHostAddress());
97 for(int i = 0; i < response.getAnswers().length; ++i) {
98 values.add(createNamePortBundle(host,5222,response.getAnswers()[i].getPayload()));
99 }
100 bundle.putParcelableArrayList("values", values);
101 return bundle;
102 }
103 for (SRV srv : result) {
104 if (ips6.containsKey(srv.getName())) {
105 values.add(createNamePortBundle(srv.getName(),srv.getPort(),ips6));
106 } else {
107 DNSMessage response = client.query(srv.getName(), TYPE.AAAA, CLASS.IN, dnsServer.getHostAddress());
108 for(int i = 0; i < response.getAnswers().length; ++i) {
109 values.add(createNamePortBundle(host,5222,response.getAnswers()[i].getPayload()));
110 }
111 }
112 if (ips4.containsKey(srv.getName())) {
113 values.add(createNamePortBundle(srv.getName(),srv.getPort(),ips4));
114 } else {
115 DNSMessage response = client.query(srv.getName(), TYPE.A, CLASS.IN, dnsServer.getHostAddress());
116 for(int i = 0; i < response.getAnswers().length; ++i) {
117 values.add(createNamePortBundle(host,5222,response.getAnswers()[i].getPayload()));
118 }
119 }
120 values.add(createNamePortBundle(srv.getName(), srv.getPort()));
121 }
122 bundle.putParcelableArrayList("values", values);
123 } catch (SocketTimeoutException e) {
124 bundle.putString("error", "timeout");
125 } catch (Exception e) {
126 Log.d(Config.LOGTAG,e.getMessage());
127 bundle.putString("error", "unhandled");
128 }
129 return bundle;
130 }
131
132 private static Bundle createNamePortBundle(String name, int port) {
133 Bundle namePort = new Bundle();
134 namePort.putString("name", name);
135 namePort.putInt("port", port);
136 return namePort;
137 }
138
139 private static Bundle createNamePortBundle(String name, int port, TreeMap<String, ArrayList<String>> ips) {
140 Bundle namePort = new Bundle();
141 namePort.putString("name", name);
142 namePort.putInt("port", port);
143 if (ips!=null) {
144 ArrayList<String> ip = ips.get(name);
145 Collections.shuffle(ip, new Random());
146 namePort.putString("ip", ip.get(0));
147 }
148 return namePort;
149 }
150
151 private static Bundle createNamePortBundle(String name, int port, Data data) {
152 Bundle namePort = new Bundle();
153 namePort.putString("name", name);
154 namePort.putInt("port", port);
155 if (data instanceof A) {
156 namePort.putString("ip", data.toString());
157 } else if (data instanceof AAAA) {
158 namePort.putString("ip","["+data.toString()+"]");
159 }
160 return namePort;
161 }
162
163 final protected static char[] hexArray = "0123456789ABCDEF".toCharArray();
164
165 public static String bytesToHex(byte[] bytes) {
166 char[] hexChars = new char[bytes.length * 2];
167 for (int j = 0; j < bytes.length; j++) {
168 int v = bytes[j] & 0xFF;
169 hexChars[j * 2] = hexArray[v >>> 4];
170 hexChars[j * 2 + 1] = hexArray[v & 0x0F];
171 }
172 return new String(hexChars);
173 }
174}