//
// ========================================================================
// Copyright (c) 1995-2014 Mort Bay Consulting Pty. Ltd.
// ------------------------------------------------------------------------
// All rights reserved. This program and the accompanying materials
// are made available under the terms of the Eclipse Public License v1.0
// and Apache License v2.0 which accompanies this distribution.
//
// The Eclipse Public License is available at
// http://www.eclipse.org/legal/epl-v10.html
//
// The Apache License v2.0 is available at
// http://www.opensource.org/licenses/apache2.0.php
//
// You may elect to redistribute this code under either of these licenses.
// ========================================================================
//
package org.eclipse.jetty.http2.parser;
import java.nio.ByteBuffer;
import org.eclipse.jetty.http2.ErrorCodes;
import org.eclipse.jetty.http2.frames.GoAwayFrame;
public class GoAwayBodyParser extends BodyParser
{
private State state = State.PREPARE;
private int cursor;
private int length;
private int lastStreamId;
private int error;
private byte[] payload;
public GoAwayBodyParser(HeaderParser headerParser, Parser.Listener listener)
{
super(headerParser, listener);
}
private void reset()
{
state = State.PREPARE;
cursor = 0;
length = 0;
lastStreamId = 0;
error = 0;
payload = null;
}
@Override
public Result parse(ByteBuffer buffer)
{
while (buffer.hasRemaining())
{
switch (state)
{
case PREPARE:
{
state = State.LAST_STREAM_ID;
length = getBodyLength();
break;
}
case LAST_STREAM_ID:
{
if (buffer.remaining() >= 4)
{
lastStreamId = buffer.getInt();
lastStreamId &= 0x7F_FF_FF_FF;
state = State.ERROR;
length -= 4;
if (length <= 0)
{
return notifyConnectionFailure(ErrorCodes.FRAME_SIZE_ERROR, "invalid_go_away_frame");
}
}
else
{
state = State.LAST_STREAM_ID_BYTES;
cursor = 4;
}
break;
}
case LAST_STREAM_ID_BYTES:
{
int currByte = buffer.get() & 0xFF;
--cursor;
lastStreamId += currByte << (8 * cursor);
--length;
if (cursor > 0 && length <= 0)
{
return notifyConnectionFailure(ErrorCodes.FRAME_SIZE_ERROR, "invalid_go_away_frame");
}
if (cursor == 0)
{
lastStreamId &= 0x7F_FF_FF_FF;
state = State.ERROR;
if (length == 0)
{
return notifyConnectionFailure(ErrorCodes.FRAME_SIZE_ERROR, "invalid_go_away_frame");
}
}
break;
}
case ERROR:
{
if (buffer.remaining() >= 4)
{
error = buffer.getInt();
state = State.PAYLOAD;
length -= 4;
if (length < 0)
{
return notifyConnectionFailure(ErrorCodes.FRAME_SIZE_ERROR, "invalid_go_away_frame");
}
if (length == 0)
{
return onGoAway(lastStreamId, error, null);
}
}
else
{
state = State.ERROR_BYTES;
cursor = 4;
}
break;
}
case ERROR_BYTES:
{
int currByte = buffer.get() & 0xFF;
--cursor;
error += currByte << (8 * cursor);
--length;
if (cursor > 0 && length <= 0)
{
return notifyConnectionFailure(ErrorCodes.FRAME_SIZE_ERROR, "invalid_go_away_frame");
}
if (cursor == 0)
{
state = State.PAYLOAD;
if (length == 0)
{
return onGoAway(lastStreamId, error, null);
}
}
break;
}
case PAYLOAD:
{
payload = new byte[length];
if (buffer.remaining() >= length)
{
buffer.get(payload);
return onGoAway(lastStreamId, error, payload);
}
else
{
state = State.PAYLOAD_BYTES;
cursor = length;
}
break;
}
case PAYLOAD_BYTES:
{
payload[payload.length - cursor] = buffer.get();
--cursor;
if (cursor == 0)
{
return onGoAway(lastStreamId, error, payload);
}
break;
}
default:
{
throw new IllegalStateException();
}
}
}
return Result.PENDING;
}
private Result onGoAway(int lastStreamId, int error, byte[] payload)
{
GoAwayFrame frame = new GoAwayFrame(lastStreamId, error, payload);
reset();
return notifyGoAway(frame) ? Result.ASYNC : Result.COMPLETE;
}
private enum State
{
PREPARE, LAST_STREAM_ID, LAST_STREAM_ID_BYTES, ERROR, ERROR_BYTES, PAYLOAD, PAYLOAD_BYTES
}
}