/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*
*/
package org.apache.directory.shared.ldap.codec.api;
import java.io.InputStream;
import java.nio.ByteBuffer;
import java.util.List;
import org.apache.directory.shared.asn1.DecoderException;
import org.apache.directory.shared.asn1.ber.Asn1Decoder;
import org.apache.directory.shared.asn1.ber.tlv.TLVStateEnum;
import org.apache.directory.shared.i18n.I18n;
import org.apache.directory.shared.ldap.model.exception.ResponseCarryingMessageException;
import org.apache.directory.shared.ldap.model.message.Message;
import org.apache.directory.shared.util.Strings;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* The LdapDecoder decodes ASN.1 BER encoded PDUs into LDAP messages
*
* @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
*/
public class LdapDecoder
{
/** The logger */
private static Logger LOG = LoggerFactory.getLogger( LdapDecoder.class );
/** A speedup for logger */
private static final boolean IS_DEBUG = LOG.isDebugEnabled();
/** The ASN 1 decoder instance */
private Asn1Decoder asn1Decoder;
/**
* Creates an instance of a Ldap Decoder implementation.
*/
public LdapDecoder()
{
asn1Decoder = new Asn1Decoder();
}
/**
* Decodes a PDU from an input stream into a Ldap message container. We can only
* decode one complete message.
*
* @param in The input stream to read and decode PDU bytes from
* @return return The decoded message
*/
public Message decode( InputStream in, LdapMessageContainer<MessageDecorator<? extends Message>> container ) throws DecoderException
{
try
{
int amount;
while ( in.available() > 0 )
{
byte[]buf = new byte[in.available()];
if ( ( amount = in.read( buf ) ) == -1 )
{
break;
}
asn1Decoder.decode( ByteBuffer.wrap( buf, 0, amount ), container );
}
}
catch ( Exception e )
{
String message = I18n.err( I18n.ERR_04060, e.getLocalizedMessage() );
LOG.error( message );
throw new DecoderException( message, e );
}
if ( container.getState() == TLVStateEnum.PDU_DECODED )
{
if ( IS_DEBUG )
{
LOG.debug( "Decoded LdapMessage : " + container );
}
return container.getMessage();
}
else
{
LOG.error( I18n.err( I18n.ERR_04062 ) );
throw new DecoderException( I18n.err( I18n.ERR_04063 ) );
}
}
/**
* Decode an incoming buffer into LDAP messages. The result can be 0, 1 or many
* LDAP messages, which will be stored into the array the caller has created.
*
* @param buffer The incoming byte buffer
* @param messageContainer The LdapMessageContainer which will be used to store the
* message being decoded. If the message is not fully decoded, the ucrrent state
* is stored into this container
* @param decodedMessages The list of decoded messages
* @throws Exception If the decoding failed
*/
public void decode( ByteBuffer buffer, LdapMessageContainer<MessageDecorator<? extends Message>> messageContainer, List<Message> decodedMessages ) throws DecoderException
{
buffer.mark();
while ( buffer.hasRemaining() )
{
try
{
if ( IS_DEBUG )
{
LOG.debug( "Decoding the PDU : " );
int size = buffer.limit();
int position = buffer.position();
int pduLength = size - position;
byte[] array = new byte[pduLength];
System.arraycopy(buffer.array(), position, array, 0, pduLength);
buffer.position( size );
if ( array.length == 0 )
{
LOG.debug( "NULL buffer, what the HELL ???" );
}
else
{
LOG.debug( Strings.dumpBytes(array) );
}
buffer.reset();
}
asn1Decoder.decode( buffer, messageContainer );
if ( messageContainer.getState() == TLVStateEnum.PDU_DECODED )
{
if ( IS_DEBUG )
{
LOG.debug( "Decoded LdapMessage : " + messageContainer.getMessage() );
}
Message message = messageContainer.getMessage();
decodedMessages.add( message );
messageContainer.clean();
}
}
catch ( DecoderException de )
{
buffer.clear();
messageContainer.clean();
if ( de instanceof ResponseCarryingException )
{
// Transform the DecoderException message to a MessageException
ResponseCarryingMessageException rcme = new ResponseCarryingMessageException( de.getMessage() );
rcme.setResponse( ( ( ResponseCarryingException ) de ).getResponse() );
throw rcme;
}
else
{
// TODO : This is certainly not the way we should handle such an exception !
throw new ResponseCarryingException( de.getMessage() );
}
}
}
}
}