View Javadoc
1   /*
2    *  Licensed to the Apache Software Foundation (ASF) under one
3    *  or more contributor license agreements.  See the NOTICE file
4    *  distributed with this work for additional information
5    *  regarding copyright ownership.  The ASF licenses this file
6    *  to you under the Apache License, Version 2.0 (the
7    *  "License"); you may not use this file except in compliance
8    *  with the License.  You may obtain a copy of the License at
9    *
10   *    http://www.apache.org/licenses/LICENSE-2.0
11   *
12   *  Unless required by applicable law or agreed to in writing,
13   *  software distributed under the License is distributed on an
14   *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15   *  KIND, either express or implied.  See the License for the
16   *  specific language governing permissions and limitations
17   *  under the License.
18   *
19   */
20  package org.apache.directory.api.ldap.codec.api;
21  
22  
23  import java.io.InputStream;
24  import java.nio.ByteBuffer;
25  
26  import org.apache.directory.api.asn1.DecoderException;
27  import org.apache.directory.api.asn1.ber.Asn1Decoder;
28  import org.apache.directory.api.asn1.ber.tlv.TLVStateEnum;
29  import org.apache.directory.api.i18n.I18n;
30  import org.apache.directory.api.ldap.model.message.Message;
31  import org.slf4j.Logger;
32  import org.slf4j.LoggerFactory;
33  
34  
35  /**
36   * The LdapDecoder decodes ASN.1 BER encoded PDUs into LDAP messages
37   *
38   * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
39   */
40  public class LdapDecoder
41  {
42      /** The logger */
43      private static Logger LOG = LoggerFactory.getLogger( LdapDecoder.class );
44  
45      /** A speedup for logger */
46      private static final boolean IS_DEBUG = LOG.isDebugEnabled();
47  
48      /** The ASN 1 decoder instance */
49      private Asn1Decoder asn1Decoder;
50  
51      /** The name of the LdapSession's attribute for the LDAP container used during the decoding */
52      public static final String MESSAGE_CONTAINER_ATTR = "LDAP-container";
53  
54      /** The maximum PDU size, stored into the LDAPSession's attribute */
55      public static final String MAX_PDU_SIZE_ATTR = "LDAP-maxPduSize";
56  
57  
58      /**
59       * Creates an instance of a Ldap Decoder implementation.
60       */
61      public LdapDecoder()
62      {
63          asn1Decoder = new Asn1Decoder();
64      }
65  
66  
67      /**
68       * Decodes a PDU from an input stream into a Ldap message container. We can only
69       * decode one complete message.
70       *
71       * @param in The input stream to read and decode PDU bytes from
72       * @return return The decoded message
73       */
74      public Message decode( InputStream in, LdapMessageContainer<MessageDecorator<? extends Message>> container )
75          throws DecoderException
76      {
77          try
78          {
79              int amount;
80  
81              while ( in.available() > 0 )
82              {
83                  byte[] buf = new byte[in.available()];
84  
85                  if ( ( amount = in.read( buf ) ) == -1 )
86                  {
87                      break;
88                  }
89  
90                  asn1Decoder.decode( ByteBuffer.wrap( buf, 0, amount ), container );
91              }
92          }
93          catch ( Exception e )
94          {
95              String message = I18n.err( I18n.ERR_04060, e.getLocalizedMessage() );
96              LOG.error( message );
97              throw new DecoderException( message, e );
98          }
99  
100         if ( container.getState() == TLVStateEnum.PDU_DECODED )
101         {
102             if ( IS_DEBUG )
103             {
104                 LOG.debug( "Decoded LdapMessage : " + container );
105             }
106 
107             return container.getMessage();
108         }
109         else
110         {
111             LOG.error( I18n.err( I18n.ERR_04062 ) );
112             throw new DecoderException( I18n.err( I18n.ERR_04063 ) );
113         }
114     }
115 
116     /**
117      * Decode an incoming buffer into LDAP messages. The result can be 0, 1 or many
118      * LDAP messages, which will be stored into the array the caller has created.
119      * 
120      * @param buffer The incoming byte buffer
121      * @param messageContainer The LdapMessageContainer which will be used to store the
122      * message being decoded. If the message is not fully decoded, the ucrrent state
123      * is stored into this container
124      * @param decodedMessages The list of decoded messages
125      * @throws Exception If the decoding failed
126      *
127     public void decode( ByteBuffer buffer, LdapMessageContainer<MessageDecorator<? extends Message>> messageContainer, List<Message> decodedMessages ) throws DecoderException
128     {
129         buffer.mark();
130 
131         while ( buffer.hasRemaining() )
132         {
133             try
134             {
135                 if ( IS_DEBUG )
136                 {
137                     LOG.debug( "Decoding the PDU : " );
138 
139                     int size = buffer.limit();
140                     int position = buffer.position();
141                     int pduLength = size - position;
142 
143                     byte[] array = new byte[pduLength];
144 
145                     System.arraycopy(buffer.array(), position, array, 0, pduLength);
146 
147                     buffer.position( size );
148 
149                     if ( array.length == 0 )
150                     {
151                         LOG.debug( "NULL buffer, what the HELL ???" );
152                     }
153                     else
154                     {
155                         LOG.debug( Strings.dumpBytes(array) );
156                     }
157 
158                     buffer.reset();
159                 }
160 
161                 asn1Decoder.decode( buffer, messageContainer );
162 
163                 if ( messageContainer.getState() == TLVStateEnum.PDU_DECODED )
164                 {
165                     if ( IS_DEBUG )
166                     {
167                         LOG.debug( "Decoded LdapMessage : " + messageContainer.getMessage() );
168                     }
169 
170                     Message message = messageContainer.getMessage();
171 
172                     decodedMessages.add( message );
173 
174                     messageContainer.clean();
175                 }
176             }
177             catch ( DecoderException de )
178             {
179                 buffer.clear();
180                 messageContainer.clean();
181 
182                 if ( de instanceof ResponseCarryingException )
183                 {
184                     // Transform the DecoderException message to a MessageException
185                     ResponseCarryingMessageException rcme = new ResponseCarryingMessageException( de.getMessage() );
186                     rcme.setResponse( ( ( ResponseCarryingException ) de ).getResponse() );
187 
188                     throw rcme;
189                 }
190                 else
191                 {
192                     // TODO : This is certainly not the way we should handle such an exception !
193                     throw new ResponseCarryingException( de.getMessage() );
194                 }
195             }
196         }
197     }*/
198 }