// Copyright 2003-2005 Arthur van Hoff, Rick Blair
// Licensed under Apache License version 2.0
// Original license LGPL
package javax.jmdns.impl;
import java.net.InetAddress;
import java.util.Set;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.jmdns.ServiceInfo;
import javax.jmdns.ServiceInfo.Fields;
import javax.jmdns.impl.JmDNSImpl.ServiceTypeEntry;
import javax.jmdns.impl.constants.DNSConstants;
import javax.jmdns.impl.constants.DNSRecordClass;
import javax.jmdns.impl.constants.DNSRecordType;
/**
* A DNS question.
*
* @author Arthur van Hoff, Pierre Frisch
*/
public class DNSQuestion extends DNSEntry {
private static Logger logger = Logger.getLogger(DNSQuestion.class.getName());
/**
* Address question.
*/
private static class DNS4Address extends DNSQuestion {
DNS4Address(String name, DNSRecordType type, DNSRecordClass recordClass, boolean unique) {
super(name, type, recordClass, unique);
}
@Override
public void addAnswers(JmDNSImpl jmDNSImpl, Set<DNSRecord> answers) {
DNSRecord answer = jmDNSImpl.getLocalHost().getDNSAddressRecord(this.getRecordType(), DNSRecordClass.UNIQUE, DNSConstants.DNS_TTL);
if (answer != null) {
answers.add(answer);
}
}
@Override
public boolean iAmTheOnlyOne(JmDNSImpl jmDNSImpl) {
String name = this.getName().toLowerCase();
return jmDNSImpl.getLocalHost().getName().equals(name) || jmDNSImpl.getServices().keySet().contains(name);
}
}
/**
* Address question.
*/
private static class DNS6Address extends DNSQuestion {
DNS6Address(String name, DNSRecordType type, DNSRecordClass recordClass, boolean unique) {
super(name, type, recordClass, unique);
}
@Override
public void addAnswers(JmDNSImpl jmDNSImpl, Set<DNSRecord> answers) {
DNSRecord answer = jmDNSImpl.getLocalHost().getDNSAddressRecord(this.getRecordType(), DNSRecordClass.UNIQUE, DNSConstants.DNS_TTL);
if (answer != null) {
answers.add(answer);
}
}
@Override
public boolean iAmTheOnlyOne(JmDNSImpl jmDNSImpl) {
String name = this.getName().toLowerCase();
return jmDNSImpl.getLocalHost().getName().equals(name) || jmDNSImpl.getServices().keySet().contains(name);
}
}
/**
* Host Information question.
*/
private static class HostInformation extends DNSQuestion {
HostInformation(String name, DNSRecordType type, DNSRecordClass recordClass, boolean unique) {
super(name, type, recordClass, unique);
}
}
/**
* Pointer question.
*/
private static class Pointer extends DNSQuestion {
Pointer(String name, DNSRecordType type, DNSRecordClass recordClass, boolean unique) {
super(name, type, recordClass, unique);
}
@Override
public void addAnswers(JmDNSImpl jmDNSImpl, Set<DNSRecord> answers) {
// find matching services
for (ServiceInfo serviceInfo : jmDNSImpl.getServices().values()) {
this.addAnswersForServiceInfo(jmDNSImpl, answers, (ServiceInfoImpl) serviceInfo);
}
if (this.isServicesDiscoveryMetaQuery()) {
for (String serviceType : jmDNSImpl.getServiceTypes().keySet()) {
ServiceTypeEntry typeEntry = jmDNSImpl.getServiceTypes().get(serviceType);
answers.add(new DNSRecord.Pointer("_services._dns-sd._udp.local.", DNSRecordClass.CLASS_IN, DNSRecordClass.NOT_UNIQUE, DNSConstants.DNS_TTL, typeEntry.getType()));
}
} else if (this.isReverseLookup()) {
String ipValue = this.getQualifiedNameMap().get(Fields.Instance);
if ((ipValue != null) && (ipValue.length() > 0)) {
InetAddress address = jmDNSImpl.getLocalHost().getInetAddress();
String hostIPAddress = (address != null ? address.getHostAddress() : "");
if (ipValue.equalsIgnoreCase(hostIPAddress)) {
if (this.isV4ReverseLookup()) {
answers.add(jmDNSImpl.getLocalHost().getDNSReverseAddressRecord(DNSRecordType.TYPE_A, DNSRecordClass.NOT_UNIQUE, DNSConstants.DNS_TTL));
}
if (this.isV6ReverseLookup()) {
answers.add(jmDNSImpl.getLocalHost().getDNSReverseAddressRecord(DNSRecordType.TYPE_AAAA, DNSRecordClass.NOT_UNIQUE, DNSConstants.DNS_TTL));
}
}
}
} else if (this.isDomainDiscoveryQuery()) {
// FIXME [PJYF Nov 16 2010] We do not currently support domain discovery
}
}
}
/**
* Service question.
*/
private static class Service extends DNSQuestion {
Service(String name, DNSRecordType type, DNSRecordClass recordClass, boolean unique) {
super(name, type, recordClass, unique);
}
@Override
public void addAnswers(JmDNSImpl jmDNSImpl, Set<DNSRecord> answers) {
String loname = this.getName().toLowerCase();
if (jmDNSImpl.getLocalHost().getName().equalsIgnoreCase(loname)) {
// type = DNSConstants.TYPE_A;
answers.addAll(jmDNSImpl.getLocalHost().answers(this.isUnique(), DNSConstants.DNS_TTL));
return;
}
// Service type request
if (jmDNSImpl.getServiceTypes().containsKey(loname)) {
DNSQuestion question = new Pointer(this.getName(), DNSRecordType.TYPE_PTR, this.getRecordClass(), this.isUnique());
question.addAnswers(jmDNSImpl, answers);
return;
}
this.addAnswersForServiceInfo(jmDNSImpl, answers, (ServiceInfoImpl) jmDNSImpl.getServices().get(loname));
}
@Override
public boolean iAmTheOnlyOne(JmDNSImpl jmDNSImpl) {
String name = this.getName().toLowerCase();
return jmDNSImpl.getLocalHost().getName().equals(name) || jmDNSImpl.getServices().keySet().contains(name);
}
}
/**
* Text question.
*/
private static class Text extends DNSQuestion {
Text(String name, DNSRecordType type, DNSRecordClass recordClass, boolean unique) {
super(name, type, recordClass, unique);
}
@Override
public void addAnswers(JmDNSImpl jmDNSImpl, Set<DNSRecord> answers) {
this.addAnswersForServiceInfo(jmDNSImpl, answers, (ServiceInfoImpl) jmDNSImpl.getServices().get(this.getName().toLowerCase()));
}
@Override
public boolean iAmTheOnlyOne(JmDNSImpl jmDNSImpl) {
String name = this.getName().toLowerCase();
return jmDNSImpl.getLocalHost().getName().equals(name) || jmDNSImpl.getServices().keySet().contains(name);
}
}
/**
* AllRecords question.
*/
private static class AllRecords extends DNSQuestion {
AllRecords(String name, DNSRecordType type, DNSRecordClass recordClass, boolean unique) {
super(name, type, recordClass, unique);
}
@Override
public boolean isSameType(DNSEntry entry) {
// We match all non null entry
return (entry != null);
}
@Override
public void addAnswers(JmDNSImpl jmDNSImpl, Set<DNSRecord> answers) {
String loname = this.getName().toLowerCase();
if (jmDNSImpl.getLocalHost().getName().equalsIgnoreCase(loname)) {
// type = DNSConstants.TYPE_A;
answers.addAll(jmDNSImpl.getLocalHost().answers(this.isUnique(), DNSConstants.DNS_TTL));
return;
}
// Service type request
if (jmDNSImpl.getServiceTypes().containsKey(loname)) {
DNSQuestion question = new Pointer(this.getName(), DNSRecordType.TYPE_PTR, this.getRecordClass(), this.isUnique());
question.addAnswers(jmDNSImpl, answers);
return;
}
this.addAnswersForServiceInfo(jmDNSImpl, answers, (ServiceInfoImpl) jmDNSImpl.getServices().get(loname));
}
@Override
public boolean iAmTheOnlyOne(JmDNSImpl jmDNSImpl) {
String name = this.getName().toLowerCase();
return jmDNSImpl.getLocalHost().getName().equals(name) || jmDNSImpl.getServices().keySet().contains(name);
}
}
DNSQuestion(String name, DNSRecordType type, DNSRecordClass recordClass, boolean unique) {
super(name, type, recordClass, unique);
}
/**
* Create a question.
*
* @param name
* DNS name to be resolved
* @param type
* Record type to resolve
* @param recordClass
* Record class to resolve
* @param unique
* Request unicast response (Currently not supported in this implementation)
* @return new question
*/
public static DNSQuestion newQuestion(String name, DNSRecordType type, DNSRecordClass recordClass, boolean unique) {
switch (type) {
case TYPE_A:
return new DNS4Address(name, type, recordClass, unique);
case TYPE_A6:
return new DNS6Address(name, type, recordClass, unique);
case TYPE_AAAA:
return new DNS6Address(name, type, recordClass, unique);
case TYPE_ANY:
return new AllRecords(name, type, recordClass, unique);
case TYPE_HINFO:
return new HostInformation(name, type, recordClass, unique);
case TYPE_PTR:
return new Pointer(name, type, recordClass, unique);
case TYPE_SRV:
return new Service(name, type, recordClass, unique);
case TYPE_TXT:
return new Text(name, type, recordClass, unique);
default:
return new DNSQuestion(name, type, recordClass, unique);
}
}
/**
* Check if this question is answered by a given DNS record.
*/
boolean answeredBy(DNSEntry rec) {
return this.isSameRecordClass(rec) && this.isSameType(rec) && this.getName().equals(rec.getName());
}
/**
* Adds answers to the list for our question.
*
* @param jmDNSImpl
* DNS holding the records
* @param answers
* List of previous answer to append.
*/
public void addAnswers(JmDNSImpl jmDNSImpl, Set<DNSRecord> answers) {
// By default we do nothing
}
protected void addAnswersForServiceInfo(JmDNSImpl jmDNSImpl, Set<DNSRecord> answers, ServiceInfoImpl info) {
if ((info != null) && info.isAnnounced()) {
if (this.getName().equalsIgnoreCase(info.getQualifiedName()) || this.getName().equalsIgnoreCase(info.getType())) {
answers.addAll(jmDNSImpl.getLocalHost().answers(DNSRecordClass.UNIQUE, DNSConstants.DNS_TTL));
answers.addAll(info.answers(DNSRecordClass.UNIQUE, DNSConstants.DNS_TTL, jmDNSImpl.getLocalHost()));
}
if (logger.isLoggable(Level.FINER)) {
logger.finer(jmDNSImpl.getName() + " DNSQuestion(" + this.getName() + ").addAnswersForServiceInfo(): info: " + info + "\n" + answers);
}
}
}
/*
* (non-Javadoc)
* @see javax.jmdns.impl.DNSEntry#isStale(long)
*/
@Override
public boolean isStale(long now) {
return false;
}
/*
* (non-Javadoc)
* @see javax.jmdns.impl.DNSEntry#isExpired(long)
*/
@Override
public boolean isExpired(long now) {
return false;
}
/**
* Checks if we are the only to be able to answer that question.
*
* @param jmDNSImpl
* DNS holding the records
* @return <code>true</code> if we are the only one with the answer to the question, <code>false</code> otherwise.
*/
public boolean iAmTheOnlyOne(JmDNSImpl jmDNSImpl) {
return false;
}
/*
* (non-Javadoc)
* @see javax.jmdns.impl.DNSEntry#toString(java.lang.StringBuilder)
*/
@Override
public void toString(StringBuilder aLog) {
// do nothing
}
}