/*
*
* 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.qpid.proton.engine.impl;
import java.nio.ByteBuffer;
import org.apache.qpid.proton.amqp.Binary;
import org.apache.qpid.proton.amqp.security.SaslFrameBody;
import org.apache.qpid.proton.codec.ByteBufferDecoder;
import org.apache.qpid.proton.codec.DecodeException;
import org.apache.qpid.proton.engine.TransportException;
class SaslFrameParser
{
private SaslFrameHandler _sasl;
enum State
{
SIZE_0,
SIZE_1,
SIZE_2,
SIZE_3,
PRE_PARSE,
BUFFERING,
PARSING,
ERROR
}
private State _state = State.SIZE_0;
private int _size;
private ByteBuffer _buffer;
private int _ignore = 8;
private final ByteBufferDecoder _decoder;
SaslFrameParser(SaslFrameHandler sasl, ByteBufferDecoder decoder)
{
_sasl = sasl;
_decoder = decoder;
}
/**
* Parse the provided SASL input and call my SASL frame handler with the result
*/
public void input(ByteBuffer input) throws TransportException
{
TransportException frameParsingError = null;
int size = _size;
State state = _state;
ByteBuffer oldIn = null;
// Note that we simply skip over the header rather than parsing it.
if(_ignore != 0)
{
int bytesToEat = Math.min(_ignore, input.remaining());
input.position(input.position() + bytesToEat);
_ignore -= bytesToEat;
}
while(input.hasRemaining() && state != State.ERROR && !_sasl.isDone())
{
switch(state)
{
case SIZE_0:
if(input.remaining() >= 4)
{
size = input.getInt();
state = State.PRE_PARSE;
break;
}
else
{
size = (input.get() << 24) & 0xFF000000;
if(!input.hasRemaining())
{
state = State.SIZE_1;
break;
}
}
case SIZE_1:
size |= (input.get() << 16) & 0xFF0000;
if(!input.hasRemaining())
{
state = State.SIZE_2;
break;
}
case SIZE_2:
size |= (input.get() << 8) & 0xFF00;
if(!input.hasRemaining())
{
state = State.SIZE_3;
break;
}
case SIZE_3:
size |= input.get() & 0xFF;
state = State.PRE_PARSE;
case PRE_PARSE:
if(size < 8)
{
frameParsingError = new TransportException("specified frame size %d smaller than minimum frame header "
+ "size %d",
_size, 8);
state = State.ERROR;
break;
}
if(input.remaining() < size-4)
{
_buffer = ByteBuffer.allocate(size-4);
_buffer.put(input);
state = State.BUFFERING;
break;
}
case BUFFERING:
if(_buffer != null)
{
if(input.remaining() < _buffer.remaining())
{
_buffer.put(input);
break;
}
else
{
ByteBuffer dup = input.duplicate();
dup.limit(dup.position()+_buffer.remaining());
input.position(input.position()+_buffer.remaining());
_buffer.put(dup);
oldIn = input;
_buffer.flip();
input = _buffer;
state = State.PARSING;
}
}
case PARSING:
int dataOffset = (input.get() << 2) & 0x3FF;
if(dataOffset < 8)
{
frameParsingError = new TransportException("specified frame data offset %d smaller than minimum frame header size %d", dataOffset, 8);
state = State.ERROR;
break;
}
else if(dataOffset > size)
{
frameParsingError = new TransportException("specified frame data offset %d larger than the frame size %d", dataOffset, _size);
state = State.ERROR;
break;
}
// type
int type = input.get() & 0xFF;
// SASL frame has no type-specific content in the frame header, so we skip next two bytes
input.get();
input.get();
if(type != SaslImpl.SASL_FRAME_TYPE)
{
frameParsingError = new TransportException("unknown frame type: %d", type);
state = State.ERROR;
break;
}
if(dataOffset!=8)
{
input.position(input.position()+dataOffset-8);
}
// oldIn null iff not working on duplicated buffer
if(oldIn == null)
{
oldIn = input;
input = input.duplicate();
final int endPos = input.position() + size - dataOffset;
input.limit(endPos);
oldIn.position(endPos);
}
try
{
_decoder.setByteBuffer(input);
Object val = _decoder.readObject();
Binary payload;
if(input.hasRemaining())
{
byte[] payloadBytes = new byte[input.remaining()];
input.get(payloadBytes);
payload = new Binary(payloadBytes);
}
else
{
payload = null;
}
if(val instanceof SaslFrameBody)
{
SaslFrameBody frameBody = (SaslFrameBody) val;
_sasl.handle(frameBody, payload);
reset();
input = oldIn;
oldIn = null;
_buffer = null;
state = State.SIZE_0;
}
else
{
state = State.ERROR;
frameParsingError = new TransportException("Unexpected frame type encountered."
+ " Found a %s which does not implement %s",
val == null ? "null" : val.getClass(), SaslFrameBody.class);
}
}
catch (DecodeException ex)
{
state = State.ERROR;
frameParsingError = new TransportException(ex);
}
break;
case ERROR:
// do nothing
}
}
_state = state;
_size = size;
if(_state == State.ERROR)
{
if(frameParsingError != null)
{
throw frameParsingError;
}
else
{
throw new TransportException("Unable to parse, probably because of a previous error");
}
}
}
private void reset()
{
_size = 0;
_state = State.SIZE_0;
}
}