1package eu.siacs.conversations.utils;
2
3import android.annotation.TargetApi;
4import android.content.Context;
5import android.net.ConnectivityManager;
6import android.net.LinkProperties;
7import android.net.Network;
8import android.os.Build;
9import android.os.Bundle;
10import android.util.Log;
11
12import java.io.IOException;
13import java.net.InetAddress;
14import java.net.SocketTimeoutException;
15import java.net.UnknownHostException;
16import java.util.ArrayList;
17import java.util.Collections;
18import java.util.List;
19import java.util.Random;
20import java.util.TreeMap;
21import java.util.regex.Pattern;
22
23import de.measite.minidns.Client;
24import de.measite.minidns.DNSMessage;
25import de.measite.minidns.Record;
26import de.measite.minidns.Record.CLASS;
27import de.measite.minidns.Record.TYPE;
28import de.measite.minidns.record.A;
29import de.measite.minidns.record.AAAA;
30import de.measite.minidns.record.Data;
31import de.measite.minidns.record.SRV;
32import de.measite.minidns.util.NameUtil;
33import eu.siacs.conversations.Config;
34import eu.siacs.conversations.xmpp.jid.Jid;
35
36public class DNSHelper {
37
38 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");
39 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");
40 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");
41 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");
42 public static final Pattern PATTERN_IPV6 = Pattern.compile("\\A(?:[0-9a-fA-F]{1,4}:){7}[0-9a-fA-F]{1,4}\\z");
43
44 protected static Client client = new Client();
45
46 public static Bundle getSRVRecord(final Jid jid, Context context) throws IOException {
47 final String host = jid.getDomainpart();
48 final List<InetAddress> servers = Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP ? getDnsServers(context) : getDnsServersPreLolipop();
49 Bundle b = null;
50 for(InetAddress server : servers) {
51 b = queryDNS(host, server);
52 if (b.containsKey("values")) {
53 return b;
54 }
55 }
56 return b;
57 }
58
59 @TargetApi(21)
60 private static List<InetAddress> getDnsServers(Context context) {
61 List<InetAddress> servers = new ArrayList<>();
62 ConnectivityManager connectivityManager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
63 Network[] networks = connectivityManager.getAllNetworks();
64 for(int i = 0; i < networks.length; ++i) {
65 LinkProperties linkProperties = connectivityManager.getLinkProperties(networks[i]);
66 servers.addAll(linkProperties.getDnsServers());
67 }
68 return servers.size() > 0 ? servers : getDnsServersPreLolipop();
69 }
70
71 private static List<InetAddress> getDnsServersPreLolipop() {
72 List<InetAddress> servers = new ArrayList<>();
73 String[] dns = client.findDNS();
74 for(int i = 0; i < dns.length; ++i) {
75 try {
76 servers.add(InetAddress.getByName(dns[i]));
77 } catch (UnknownHostException e) {
78 //ignore
79 }
80 }
81 return servers;
82 }
83
84 public static Bundle queryDNS(String host, InetAddress dnsServer) {
85 Bundle bundle = new Bundle();
86 try {
87 String qname = "_xmpp-client._tcp." + host;
88 Log.d(Config.LOGTAG, "using dns server: " + dnsServer.getHostAddress() + " to look up " + host);
89 DNSMessage message = client.query(qname, TYPE.SRV, CLASS.IN, dnsServer.getHostAddress());
90
91 TreeMap<Integer, ArrayList<SRV>> priorities = new TreeMap<>();
92 TreeMap<String, ArrayList<String>> ips4 = new TreeMap<>();
93 TreeMap<String, ArrayList<String>> ips6 = new TreeMap<>();
94
95 for (Record[] rrset : new Record[][] { message.getAnswers(), message.getAdditionalResourceRecords() }) {
96 for (Record rr : rrset) {
97 Data d = rr.getPayload();
98 if (d instanceof SRV && NameUtil.idnEquals(qname, rr.getName())) {
99 SRV srv = (SRV) d;
100 if (!priorities.containsKey(srv.getPriority())) {
101 priorities.put(srv.getPriority(),new ArrayList<SRV>());
102 }
103 priorities.get(srv.getPriority()).add(srv);
104 }
105 if (d instanceof A) {
106 A a = (A) d;
107 if (!ips4.containsKey(rr.getName())) {
108 ips4.put(rr.getName(), new ArrayList<String>());
109 }
110 ips4.get(rr.getName()).add(a.toString());
111 }
112 if (d instanceof AAAA) {
113 AAAA aaaa = (AAAA) d;
114 if (!ips6.containsKey(rr.getName())) {
115 ips6.put(rr.getName(), new ArrayList<String>());
116 }
117 ips6.get(rr.getName()).add("[" + aaaa.toString() + "]");
118 }
119 }
120 }
121
122 ArrayList<SRV> result = new ArrayList<>();
123 for (ArrayList<SRV> s : priorities.values()) {
124 result.addAll(s);
125 }
126
127 ArrayList<Bundle> values = new ArrayList<>();
128 if (result.size() == 0) {
129 DNSMessage response;
130 try {
131 response = client.query(host, TYPE.A, CLASS.IN, dnsServer.getHostAddress());
132 for (int i = 0; i < response.getAnswers().length; ++i) {
133 values.add(createNamePortBundle(host, 5222, response.getAnswers()[i].getPayload()));
134 }
135 } catch (SocketTimeoutException e) {
136 Log.d(Config.LOGTAG,"ignoring timeout exception when querying A record on "+dnsServer.getHostAddress());
137 }
138 try {
139 response = client.query(host, TYPE.AAAA, CLASS.IN, dnsServer.getHostAddress());
140 for (int i = 0; i < response.getAnswers().length; ++i) {
141 values.add(createNamePortBundle(host, 5222, response.getAnswers()[i].getPayload()));
142 }
143 } catch (SocketTimeoutException e) {
144 Log.d(Config.LOGTAG,"ignoring timeout exception when querying AAAA record on "+dnsServer.getHostAddress());
145 }
146 values.add(createNamePortBundle(host,5222));
147 bundle.putParcelableArrayList("values", values);
148 return bundle;
149 }
150 for (SRV srv : result) {
151 if (ips6.containsKey(srv.getName())) {
152 values.add(createNamePortBundle(srv.getName(),srv.getPort(),ips6));
153 } else {
154 try {
155 DNSMessage response = client.query(srv.getName(), TYPE.AAAA, CLASS.IN, dnsServer.getHostAddress());
156 for (int i = 0; i < response.getAnswers().length; ++i) {
157 values.add(createNamePortBundle(srv.getName(), srv.getPort(), response.getAnswers()[i].getPayload()));
158 }
159 } catch (SocketTimeoutException e) {
160 Log.d(Config.LOGTAG,"ignoring timeout exception when querying AAAA record on "+dnsServer.getHostAddress());
161 }
162 }
163 if (ips4.containsKey(srv.getName())) {
164 values.add(createNamePortBundle(srv.getName(),srv.getPort(),ips4));
165 } else {
166 DNSMessage response = client.query(srv.getName(), TYPE.A, CLASS.IN, dnsServer.getHostAddress());
167 for(int i = 0; i < response.getAnswers().length; ++i) {
168 values.add(createNamePortBundle(srv.getName(),srv.getPort(),response.getAnswers()[i].getPayload()));
169 }
170 }
171 values.add(createNamePortBundle(srv.getName(), srv.getPort()));
172 }
173 bundle.putParcelableArrayList("values", values);
174 } catch (SocketTimeoutException e) {
175 bundle.putString("error", "timeout");
176 } catch (Exception e) {
177 bundle.putString("error", "unhandled");
178 }
179 return bundle;
180 }
181
182 private static Bundle createNamePortBundle(String name, int port) {
183 Bundle namePort = new Bundle();
184 namePort.putString("name", name);
185 namePort.putInt("port", port);
186 return namePort;
187 }
188
189 private static Bundle createNamePortBundle(String name, int port, TreeMap<String, ArrayList<String>> ips) {
190 Bundle namePort = new Bundle();
191 namePort.putString("name", name);
192 namePort.putInt("port", port);
193 if (ips!=null) {
194 ArrayList<String> ip = ips.get(name);
195 Collections.shuffle(ip, new Random());
196 namePort.putString("ip", ip.get(0));
197 }
198 return namePort;
199 }
200
201 private static Bundle createNamePortBundle(String name, int port, Data data) {
202 Bundle namePort = new Bundle();
203 namePort.putString("name", name);
204 namePort.putInt("port", port);
205 if (data instanceof A) {
206 namePort.putString("ip", data.toString());
207 } else if (data instanceof AAAA) {
208 namePort.putString("ip","["+data.toString()+"]");
209 }
210 return namePort;
211 }
212
213 public static boolean isIp(final String server) {
214 return PATTERN_IPV4.matcher(server).matches()
215 || PATTERN_IPV6.matcher(server).matches()
216 || PATTERN_IPV6_6HEX4DEC.matcher(server).matches()
217 || PATTERN_IPV6_HEX4DECCOMPRESSED.matcher(server).matches()
218 || PATTERN_IPV6_HEXCOMPRESSED.matcher(server).matches();
219 }
220}