anotherim/src/main/java/eu/siacs/conversations/utils/Resolver.java
2018-09-26 10:18:56 +02:00

380 lines
15 KiB
Java

package eu.siacs.conversations.utils;
import android.content.ContentValues;
import android.database.Cursor;
import android.support.annotation.NonNull;
import android.util.Log;
import java.io.IOException;
import java.lang.reflect.Field;
import java.net.Inet4Address;
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import de.measite.minidns.AbstractDNSClient;
import de.measite.minidns.DNSClient;
import de.measite.minidns.DNSName;
import de.measite.minidns.Question;
import de.measite.minidns.Record;
import de.measite.minidns.dnssec.DNSSECResultNotAuthenticException;
import de.measite.minidns.dnsserverlookup.AndroidUsingExec;
import de.measite.minidns.hla.DnssecResolverApi;
import de.measite.minidns.hla.ResolverApi;
import de.measite.minidns.hla.ResolverResult;
import de.measite.minidns.iterative.ReliableDNSClient;
import de.measite.minidns.record.A;
import de.measite.minidns.record.AAAA;
import de.measite.minidns.record.CNAME;
import de.measite.minidns.record.Data;
import de.measite.minidns.record.InternetAddressRR;
import de.measite.minidns.record.SRV;
import eu.siacs.conversations.Config;
import eu.siacs.conversations.R;
import eu.siacs.conversations.services.XmppConnectionService;
public class Resolver {
private static final String DIRECT_TLS_SERVICE = "_xmpps-client";
private static final String STARTTLS_SERICE = "_xmpp-client";
private static XmppConnectionService SERVICE = null;
public static void init(XmppConnectionService service) {
Resolver.SERVICE = service;
DNSClient.removeDNSServerLookupMechanism(AndroidUsingExec.INSTANCE);
DNSClient.addDnsServerLookupMechanism(AndroidUsingExecLowPriority.INSTANCE);
DNSClient.addDnsServerLookupMechanism(new AndroidUsingLinkProperties(service));
final AbstractDNSClient client = ResolverApi.INSTANCE.getClient();
if (client instanceof ReliableDNSClient) {
disableHardcodedDnsServers((ReliableDNSClient) client);
}
}
private static void disableHardcodedDnsServers(ReliableDNSClient reliableDNSClient) {
try {
final Field dnsClientField = ReliableDNSClient.class.getDeclaredField("dnsClient");
dnsClientField.setAccessible(true);
final DNSClient dnsClient = (DNSClient) dnsClientField.get(reliableDNSClient);
dnsClient.getDataSource().setTimeout(3000);
final Field useHardcodedDnsServers = DNSClient.class.getDeclaredField("useHardcodedDnsServers");
useHardcodedDnsServers.setAccessible(true);
useHardcodedDnsServers.setBoolean(dnsClient, false);
} catch (NoSuchFieldException | IllegalAccessException e) {
Log.e(Config.LOGTAG, "Unable to disable hardcoded DNS servers", e);
}
}
public static List<Result> resolve(String domain) {
final List<Result> results = new ArrayList<>();
final List<Result> fallbackResults = new ArrayList<>();
Thread[] threads = new Thread[3];
threads[0] = new Thread(() -> {
try {
final List<Result> list = resolveSrv(domain, true);
synchronized (results) {
results.addAll(list);
}
} catch (Throwable throwable) {
Log.d(Config.LOGTAG, Resolver.class.getSimpleName() + ": error resolving SRV record (direct TLS)", throwable);
}
});
threads[1] = new Thread(() -> {
try {
final List<Result> list = resolveSrv(domain, false);
synchronized (results) {
results.addAll(list);
}
} catch (Throwable throwable) {
Log.d(Config.LOGTAG, Resolver.class.getSimpleName() + ": error resolving SRV record (STARTTLS)", throwable);
}
});
threads[2] = new Thread(() -> {
List<Result> list = resolveNoSrvRecords(DNSName.from(domain), true);
synchronized (fallbackResults) {
fallbackResults.addAll(list);
}
});
for (Thread thread : threads) {
thread.start();
}
try {
threads[0].join();
threads[1].join();
if (results.size() > 0) {
threads[2].interrupt();
synchronized (results) {
Collections.sort(results);
Log.d(Config.LOGTAG, Resolver.class.getSimpleName() + ": " + results.toString());
return new ArrayList<>(results);
}
} else {
threads[2].join();
synchronized (fallbackResults) {
Collections.sort(fallbackResults);
Log.d(Config.LOGTAG, Resolver.class.getSimpleName() + ": " + fallbackResults.toString());
return new ArrayList<>(fallbackResults);
}
}
} catch (InterruptedException e) {
for(Thread thread : threads) {
thread.interrupt();
}
synchronized (results) {
return new ArrayList<>(results);
}
}
}
private static List<Result> resolveSrv(String domain, final boolean directTls) throws IOException {
DNSName dnsName = DNSName.from((directTls ? DIRECT_TLS_SERVICE : STARTTLS_SERICE) + "._tcp." + domain);
ResolverResult<SRV> result = resolveWithFallback(dnsName, SRV.class);
final List<Result> results = new ArrayList<>();
final List<Thread> threads = new ArrayList<>();
for (SRV record : result.getAnswersOrEmptySet()) {
if (record.name.length() == 0 && record.priority == 0) {
continue;
}
threads.add(new Thread(() -> {
final List<Result> ipv4s = resolveIp(record, A.class, result.isAuthenticData(), directTls);
if (ipv4s.size() == 0) {
Result resolverResult = Result.fromRecord(record, directTls);
resolverResult.authenticated = resolverResult.isAuthenticated();
ipv4s.add(resolverResult);
}
synchronized (results) {
results.addAll(ipv4s);
}
}));
threads.add(new Thread(() -> {
final List<Result> ipv6s = resolveIp(record, AAAA.class, result.isAuthenticData(), directTls);
synchronized (results) {
results.addAll(ipv6s);
}
}));
}
for (Thread thread : threads) {
thread.start();
}
for (Thread thread : threads) {
try {
thread.join();
} catch (InterruptedException e) {
return Collections.emptyList();
}
}
return results;
}
private static <D extends InternetAddressRR> List<Result> resolveIp(SRV srv, Class<D> type, boolean authenticated, boolean directTls) {
List<Result> list = new ArrayList<>();
try {
ResolverResult<D> results = resolveWithFallback(srv.name, type, authenticated);
for (D record : results.getAnswersOrEmptySet()) {
Result resolverResult = Result.fromRecord(srv, directTls);
resolverResult.authenticated = results.isAuthenticData() && authenticated;
resolverResult.ip = record.getInetAddress();
list.add(resolverResult);
}
} catch (Throwable t) {
Log.d(Config.LOGTAG, Resolver.class.getSimpleName() + ": error resolving " + type.getSimpleName() + " " + t.getMessage());
}
return list;
}
private static List<Result> resolveNoSrvRecords(DNSName dnsName, boolean withCnames) {
List<Result> results = new ArrayList<>();
try {
for (A a : resolveWithFallback(dnsName, A.class, false).getAnswersOrEmptySet()) {
results.add(Result.createDefault(dnsName, a.getInetAddress()));
}
for (AAAA aaaa : resolveWithFallback(dnsName, AAAA.class, false).getAnswersOrEmptySet()) {
results.add(Result.createDefault(dnsName, aaaa.getInetAddress()));
}
if (results.size() == 0 && withCnames) {
for (CNAME cname : resolveWithFallback(dnsName, CNAME.class, false).getAnswersOrEmptySet()) {
results.addAll(resolveNoSrvRecords(cname.name, false));
}
}
} catch (Throwable throwable) {
Log.d(Config.LOGTAG, Resolver.class.getSimpleName() + "error resolving fallback records", throwable);
}
results.add(Result.createDefault(dnsName));
return results;
}
private static <D extends Data> ResolverResult<D> resolveWithFallback(DNSName dnsName, Class<D> type) throws IOException {
return resolveWithFallback(dnsName, type, validateHostname());
}
private static <D extends Data> ResolverResult<D> resolveWithFallback(DNSName dnsName, Class<D> type, boolean validateHostname) throws IOException {
final Question question = new Question(dnsName, Record.TYPE.getType(type));
if (!validateHostname) {
return ResolverApi.INSTANCE.resolve(question);
}
try {
return DnssecResolverApi.INSTANCE.resolveDnssecReliable(question);
} catch (DNSSECResultNotAuthenticException e) {
Log.d(Config.LOGTAG, Resolver.class.getSimpleName() + ": error resolving " + type.getSimpleName() + " with DNSSEC. Trying DNS instead.", e);
} catch (IOException e) {
throw e;
} catch (Throwable throwable) {
Log.d(Config.LOGTAG, Resolver.class.getSimpleName() + ": error resolving " + type.getSimpleName() + " with DNSSEC. Trying DNS instead.", throwable);
}
return ResolverApi.INSTANCE.resolve(question);
}
private static boolean validateHostname() {
return SERVICE != null && SERVICE.getBooleanPreference("validate_hostname", R.bool.validate_hostname);
}
public static class Result implements Comparable<Result> {
public static final String DOMAIN = "domain";
public static final String IP = "ip";
public static final String HOSTNAME = "hostname";
public static final String PORT = "port";
public static final String PRIORITY = "priority";
public static final String DIRECT_TLS = "directTls";
public static final String AUTHENTICATED = "authenticated";
private InetAddress ip;
private DNSName hostname;
private int port = 5222;
private boolean directTls = false;
private boolean authenticated = false;
private int priority;
static Result fromRecord(SRV srv, boolean directTls) {
Result result = new Result();
result.port = srv.port;
result.hostname = srv.name;
result.directTls = directTls;
result.priority = srv.priority;
return result;
}
static Result createDefault(DNSName hostname, InetAddress ip) {
Result result = new Result();
result.port = 5222;
result.hostname = hostname;
result.ip = ip;
return result;
}
static Result createDefault(DNSName hostname) {
return createDefault(hostname, null);
}
public static Result fromCursor(Cursor cursor) {
final Result result = new Result();
try {
result.ip = InetAddress.getByAddress(cursor.getBlob(cursor.getColumnIndex(IP)));
} catch (UnknownHostException e) {
result.ip = null;
}
result.hostname = DNSName.from(cursor.getString(cursor.getColumnIndex(HOSTNAME)));
result.port = cursor.getInt(cursor.getColumnIndex(PORT));
result.priority = cursor.getInt(cursor.getColumnIndex(PRIORITY));
result.authenticated = cursor.getInt(cursor.getColumnIndex(AUTHENTICATED)) > 0;
result.directTls = cursor.getInt(cursor.getColumnIndex(DIRECT_TLS)) > 0;
return result;
}
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
Result result = (Result) o;
if (port != result.port) return false;
if (directTls != result.directTls) return false;
if (authenticated != result.authenticated) return false;
if (priority != result.priority) return false;
if (ip != null ? !ip.equals(result.ip) : result.ip != null) return false;
return hostname != null ? hostname.equals(result.hostname) : result.hostname == null;
}
@Override
public int hashCode() {
int result = ip != null ? ip.hashCode() : 0;
result = 31 * result + (hostname != null ? hostname.hashCode() : 0);
result = 31 * result + port;
result = 31 * result + (directTls ? 1 : 0);
result = 31 * result + (authenticated ? 1 : 0);
result = 31 * result + priority;
return result;
}
public InetAddress getIp() {
return ip;
}
public int getPort() {
return port;
}
public DNSName getHostname() {
return hostname;
}
public boolean isDirectTls() {
return directTls;
}
public boolean isAuthenticated() {
return authenticated;
}
@Override
public String toString() {
return "Result{" +
"ip='" + (ip == null ? null : ip.getHostAddress()) + '\'' +
", hostame='" + hostname.toString() + '\'' +
", port=" + port +
", directTls=" + directTls +
", authenticated=" + authenticated +
", priority=" + priority +
'}';
}
@Override
public int compareTo(@NonNull Result result) {
if (result.priority == priority) {
if (directTls == result.directTls) {
if (ip == null && result.ip == null) {
return 0;
} else if (ip != null && result.ip != null) {
if (ip instanceof Inet4Address && result.ip instanceof Inet4Address) {
return 0;
} else {
return ip instanceof Inet4Address ? -1 : 1;
}
} else {
return ip != null ? -1 : 1;
}
} else {
return directTls ? -1 : 1;
}
} else {
return priority - result.priority;
}
}
public ContentValues toContentValues() {
final ContentValues contentValues = new ContentValues();
contentValues.put(IP, ip == null ? null : ip.getAddress());
contentValues.put(HOSTNAME, hostname.toString());
contentValues.put(PORT, port);
contentValues.put(PRIORITY, priority);
contentValues.put(DIRECT_TLS, directTls ? 1 : 0);
contentValues.put(AUTHENTICATED, authenticated ? 1 : 0);
return contentValues;
}
}
}