org.eclipse.jetty.spdy.parser.ControlFrameParser Maven / Gradle / Ivy
//
// ========================================================================
// Copyright (c) 1995-2018 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.spdy.parser;
import java.nio.ByteBuffer;
import java.util.EnumMap;
import org.eclipse.jetty.spdy.CompressionFactory;
import org.eclipse.jetty.spdy.frames.ControlFrame;
import org.eclipse.jetty.spdy.frames.ControlFrameType;
public abstract class ControlFrameParser
{
private final EnumMap parsers = new EnumMap<>(ControlFrameType.class);
private final ControlFrameBodyParser unknownParser = new UnknownControlFrameBodyParser(this);
private State state = State.VERSION;
private int cursor;
private short version;
private short type;
private byte flags;
private int length;
private ControlFrameBodyParser bodyParser;
private int bytesToSkip = 0;
public ControlFrameParser(CompressionFactory.Decompressor decompressor)
{
parsers.put(ControlFrameType.SYN_STREAM, new SynStreamBodyParser(decompressor, this));
parsers.put(ControlFrameType.SYN_REPLY, new SynReplyBodyParser(decompressor, this));
parsers.put(ControlFrameType.RST_STREAM, new RstStreamBodyParser(this));
parsers.put(ControlFrameType.SETTINGS, new SettingsBodyParser(this));
parsers.put(ControlFrameType.NOOP, new NoOpBodyParser(this));
parsers.put(ControlFrameType.PING, new PingBodyParser(this));
parsers.put(ControlFrameType.GO_AWAY, new GoAwayBodyParser(this));
parsers.put(ControlFrameType.HEADERS, new HeadersBodyParser(decompressor, this));
parsers.put(ControlFrameType.WINDOW_UPDATE, new WindowUpdateBodyParser(this));
parsers.put(ControlFrameType.CREDENTIAL, new CredentialBodyParser(this));
}
public short getVersion()
{
return version;
}
public byte getFlags()
{
return flags;
}
public int getLength()
{
return length;
}
public void skip(int bytesToSkip)
{
state = State.SKIP;
this.bytesToSkip = bytesToSkip;
}
public boolean parse(ByteBuffer buffer)
{
while (buffer.hasRemaining())
{
switch (state)
{
case VERSION:
{
if (buffer.remaining() >= 2)
{
version = (short)(buffer.getShort() & 0x7F_FF);
state = State.TYPE;
}
else
{
state = State.VERSION_BYTES;
cursor = 2;
}
break;
}
case VERSION_BYTES:
{
byte currByte = buffer.get();
--cursor;
version += (currByte & 0xFF) << 8 * cursor;
if (cursor == 0)
{
version &= 0x7F_FF;
state = State.TYPE;
}
break;
}
case TYPE:
{
if (buffer.remaining() >= 2)
{
type = buffer.getShort();
state = State.FLAGS;
}
else
{
state = State.TYPE_BYTES;
cursor = 2;
}
break;
}
case TYPE_BYTES:
{
byte currByte = buffer.get();
--cursor;
type += (currByte & 0xFF) << 8 * cursor;
if (cursor == 0)
state = State.FLAGS;
break;
}
case FLAGS:
{
flags = buffer.get();
cursor = 3;
state = State.LENGTH;
break;
}
case LENGTH:
{
byte currByte = buffer.get();
--cursor;
length += (currByte & 0xFF) << 8 * cursor;
if (cursor > 0)
break;
ControlFrameType controlFrameType = ControlFrameType.from(type);
// SPEC v3, 2.2.1: unrecognized control frames must be ignored
if (controlFrameType == null)
bodyParser = unknownParser;
else
bodyParser = parsers.get(controlFrameType);
state = State.BODY;
// We have to let it fall through the next switch:
// the NOOP frame has no body and we cannot break
// because the buffer may be consumed and we will
// never enter the BODY case.
}
case BODY:
{
if (bodyParser.parse(buffer))
{
reset();
return true;
}
break;
}
case SKIP:
{
int remaining = buffer.remaining();
if (remaining >= bytesToSkip)
{
buffer.position(buffer.position() + bytesToSkip);
reset();
return true;
}
else
{
buffer.position(buffer.limit());
bytesToSkip = bytesToSkip - remaining;
return false;
}
}
default:
{
throw new IllegalStateException();
}
}
}
return false;
}
void reset()
{
state = State.VERSION;
cursor = 0;
version = 0;
type = 0;
flags = 0;
length = 0;
bodyParser = null;
bytesToSkip = 0;
}
protected abstract void onControlFrame(ControlFrame frame);
private enum State
{
VERSION, VERSION_BYTES, TYPE, TYPE_BYTES, FLAGS, LENGTH, BODY, SKIP
}
}