001 /*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements. See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership. The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License. You may obtain a copy of the License at
009 *
010 * http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing,
013 * software distributed under the License is distributed on an
014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015 * KIND, either express or implied. See the License for the
016 * specific language governing permissions and limitations
017 * under the License.
018 *
019 */
020 package org.apache.directory.server.dns.service;
021
022
023 import java.util.ArrayList;
024 import java.util.Iterator;
025 import java.util.List;
026 import java.util.Set;
027
028 import org.apache.directory.server.dns.DnsException;
029 import org.apache.directory.server.dns.messages.DnsMessage;
030 import org.apache.directory.server.dns.messages.DnsMessageModifier;
031 import org.apache.directory.server.dns.messages.MessageType;
032 import org.apache.directory.server.dns.messages.OpCode;
033 import org.apache.directory.server.dns.messages.QuestionRecord;
034 import org.apache.directory.server.dns.messages.ResourceRecord;
035 import org.apache.directory.server.dns.messages.ResponseCode;
036 import org.apache.directory.server.dns.store.RecordStore;
037 import org.apache.directory.server.i18n.I18n;
038 import org.slf4j.Logger;
039 import org.slf4j.LoggerFactory;
040
041
042 /**
043 * Domain Name Service (DNS) Protocol (RFC 1034, 1035)
044 *
045 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
046 * @version $Rev: 901657 $, $Date: 2010-01-21 13:27:15 +0200 (Thu, 21 Jan 2010) $
047 */
048 public class DomainNameService
049 {
050 /** the log for this class */
051 private static final Logger LOG = LoggerFactory.getLogger( DomainNameService.class );
052
053
054 /**
055 * Creates a new instance of DomainNameService.
056 */
057 public static void execute( DnsContext dnsContext, DnsMessage request ) throws Exception
058 {
059 if ( LOG.isDebugEnabled() )
060 {
061 monitorRequest( request );
062 }
063
064 getResourceRecords( dnsContext, request );
065
066 if ( LOG.isDebugEnabled() )
067 {
068 monitorContext( dnsContext );
069 }
070
071 buildReply( dnsContext, request );
072
073 if ( LOG.isDebugEnabled() )
074 {
075 monitorReply( dnsContext );
076 }
077 }
078
079 private static void monitorRequest( DnsMessage request ) throws Exception
080 {
081 try
082 {
083 LOG.debug( monitorMessage( request, "request" ) );
084 }
085 catch ( Exception e )
086 {
087 // This is a monitor. No exceptions should bubble up.
088 LOG.error( I18n.err( I18n.ERR_153 ), e );
089 }
090 }
091
092
093 private static void getResourceRecords( DnsContext dnsContext, DnsMessage request ) throws Exception
094 {
095 RecordStore store = dnsContext.getStore();
096
097 List<QuestionRecord> questions = request.getQuestionRecords();
098
099 Iterator<QuestionRecord> it = questions.iterator();
100
101 while ( it.hasNext() )
102 {
103 dnsContext.addResourceRecords( getEntry( store, it.next() ) );
104 }
105 }
106
107
108 /**
109 * Returns a set of {@link ResourceRecord}s from a {@link RecordStore}, given a DNS {@link QuestionRecord}.
110 *
111 * @param store
112 * @param question
113 * @return The set of {@link ResourceRecord}s.
114 * @throws DNSException
115 */
116 private static Set<ResourceRecord> getEntry( RecordStore store, QuestionRecord question ) throws DnsException
117 {
118 Set<ResourceRecord> records = null;
119
120 records = store.getRecords( question );
121
122 if ( records == null || records.isEmpty() )
123 {
124 LOG.debug( "The domain name referenced in the query does not exist." );
125
126 throw new DnsException( ResponseCode.NAME_ERROR );
127 }
128
129 return records;
130 }
131
132
133 private static void monitorContext( DnsContext dnsContext ) throws Exception
134 {
135 try
136 {
137 RecordStore store = dnsContext.getStore();
138 List<ResourceRecord> records = dnsContext.getResourceRecords();
139
140 StringBuffer sb = new StringBuffer();
141 sb.append( "Monitoring context:" );
142 sb.append( "\n\t" + "store: " + store );
143 sb.append( "\n\t" + "records: " + records );
144
145 LOG.debug( sb.toString() );
146 }
147 catch ( Exception e )
148 {
149 // This is a monitor. No exceptions should bubble up.
150 LOG.error( I18n.err( I18n.ERR_154 ), e );
151 }
152 }
153
154
155 private static void buildReply( DnsContext dnsContext, DnsMessage request ) throws Exception
156 {
157 List<ResourceRecord> records = dnsContext.getResourceRecords();
158
159 DnsMessageModifier modifier = new DnsMessageModifier();
160
161 modifier.setTransactionId( request.getTransactionId() );
162 modifier.setMessageType( MessageType.RESPONSE );
163 modifier.setOpCode( OpCode.QUERY );
164 modifier.setAuthoritativeAnswer( false );
165 modifier.setTruncated( false );
166 modifier.setRecursionDesired( request.isRecursionDesired() );
167 modifier.setRecursionAvailable( false );
168 modifier.setReserved( false );
169 modifier.setAcceptNonAuthenticatedData( false );
170 modifier.setResponseCode( ResponseCode.NO_ERROR );
171 modifier.setQuestionRecords( request.getQuestionRecords() );
172
173 modifier.setAnswerRecords( records );
174 modifier.setAuthorityRecords( new ArrayList<ResourceRecord>() );
175 modifier.setAdditionalRecords( new ArrayList<ResourceRecord>() );
176
177 dnsContext.setReply( modifier.getDnsMessage() );
178 }
179
180
181 private static void monitorReply( DnsContext dnsContext ) throws Exception
182 {
183 try
184 {
185 DnsMessage reply = dnsContext.getReply();
186
187 LOG.debug( monitorMessage( reply, "reply" ) );
188 }
189 catch ( Exception e )
190 {
191 // This is a monitor. No exceptions should bubble up.
192 LOG.error( I18n.err( I18n.ERR_155 ), e );
193 }
194 }
195
196
197 private static String monitorMessage( DnsMessage message, String direction )
198 {
199 MessageType messageType = message.getMessageType();
200 OpCode opCode = message.getOpCode();
201 ResponseCode responseCode = message.getResponseCode();
202 int transactionId = message.getTransactionId();
203
204 StringBuffer sb = new StringBuffer();
205 sb.append( "Monitoring " + direction + ":" );
206 sb.append( "\n\t" + "messageType " + messageType );
207 sb.append( "\n\t" + "opCode " + opCode );
208 sb.append( "\n\t" + "responseCode " + responseCode );
209 sb.append( "\n\t" + "transactionId " + transactionId );
210
211 sb.append( "\n\t" + "authoritativeAnswer " + message.isAuthoritativeAnswer() );
212 sb.append( "\n\t" + "truncated " + message.isTruncated() );
213 sb.append( "\n\t" + "recursionDesired " + message.isRecursionDesired() );
214 sb.append( "\n\t" + "recursionAvailable " + message.isRecursionAvailable() );
215 sb.append( "\n\t" + "reserved " + message.isReserved() );
216 sb.append( "\n\t" + "acceptNonAuthenticatedData " + message.isAcceptNonAuthenticatedData() );
217
218 List<QuestionRecord> questions = message.getQuestionRecords();
219
220 sb.append( "\n\t" + "questions: " + questions );
221
222 return sb.toString();
223 }
224 }