/*
* 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.protocol.mina;
import java.nio.ByteBuffer;
import java.util.ArrayList;
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.ldap.codec.api.LdapDecoder;
import org.apache.directory.shared.ldap.codec.api.LdapMessageContainer;
import org.apache.directory.shared.ldap.codec.api.MessageDecorator;
import org.apache.directory.shared.ldap.codec.api.ResponseCarryingException;
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.apache.mina.core.buffer.IoBuffer;
import org.apache.mina.core.session.IoSession;
import org.apache.mina.filter.codec.ProtocolDecoder;
import org.apache.mina.filter.codec.ProtocolDecoderOutput;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* A LDAP message decoder. It is based on shared-ldap decoder.
*
* @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
*/
public class LdapProtocolDecoder implements ProtocolDecoder
{
/** 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 a new instance of LdapProtocolEncoder.
*
* @param codec The LDAP codec service associated with this encoder.
*/
public LdapProtocolDecoder()
{
asn1Decoder = new Asn1Decoder();
}
/**
* {@inheritDoc}
*/
public void decode( IoSession session, IoBuffer in, ProtocolDecoderOutput out ) throws Exception
{
@SuppressWarnings("unchecked")
LdapMessageContainer<MessageDecorator<? extends Message>> messageContainer =
( LdapMessageContainer<MessageDecorator<? extends Message>> )
session.getAttribute( LdapDecoder.MESSAGE_CONTAINER_ATTR );
if ( session.containsAttribute( LdapDecoder.MAX_PDU_SIZE_ATTR ) )
{
int maxPDUSize = ( Integer ) session.getAttribute( LdapDecoder.MAX_PDU_SIZE_ATTR );
messageContainer.setMaxPDUSize( maxPDUSize );
}
List<Message> decodedMessages = new ArrayList<Message>();
ByteBuffer buf = in.buf();
decode( buf, messageContainer, decodedMessages );
for ( Message message : decodedMessages )
{
out.write( message );
}
}
/**
* 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
*/
private 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() );
}
}
}
}
/**
* {@inheritDoc}
*/
public void finishDecode( IoSession session, ProtocolDecoderOutput out ) throws Exception
{
// Nothing to do
}
/**
* {@inheritDoc}
*/
public void dispose( IoSession session ) throws Exception
{
// Nothing to do
}
}