org.eclipse.jetty.spdy.parser.SynStreamBodyParser Maven / Gradle / Ivy
//
// ========================================================================
// 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.spdy.parser;
import java.nio.ByteBuffer;
import org.eclipse.jetty.spdy.CompressionFactory;
import org.eclipse.jetty.spdy.PushSynInfo;
import org.eclipse.jetty.spdy.StreamException;
import org.eclipse.jetty.spdy.api.SPDY;
import org.eclipse.jetty.spdy.api.StreamStatus;
import org.eclipse.jetty.spdy.api.SynInfo;
import org.eclipse.jetty.spdy.frames.ControlFrameType;
import org.eclipse.jetty.spdy.frames.SynStreamFrame;
import org.eclipse.jetty.util.Fields;
public class SynStreamBodyParser extends ControlFrameBodyParser
{
private final Fields headers = new Fields();
private final ControlFrameParser controlFrameParser;
private final HeadersBlockParser headersBlockParser;
private State state = State.STREAM_ID;
private int cursor;
private int streamId;
private int associatedStreamId;
private byte priority;
private short slot;
public SynStreamBodyParser(CompressionFactory.Decompressor decompressor, ControlFrameParser controlFrameParser)
{
this.controlFrameParser = controlFrameParser;
this.headersBlockParser = new SynStreamHeadersBlockParser(decompressor);
}
@Override
public boolean parse(ByteBuffer buffer)
{
while (buffer.hasRemaining())
{
switch (state)
{
case STREAM_ID:
{
if (buffer.remaining() >= 4)
{
streamId = buffer.getInt() & 0x7F_FF_FF_FF;
state = State.ASSOCIATED_STREAM_ID;
}
else
{
state = State.STREAM_ID_BYTES;
cursor = 4;
}
break;
}
case STREAM_ID_BYTES:
{
byte currByte = buffer.get();
--cursor;
streamId += (currByte & 0xFF) << 8 * cursor;
if (cursor == 0)
{
streamId &= 0x7F_FF_FF_FF;
state = State.ASSOCIATED_STREAM_ID;
}
break;
}
case ASSOCIATED_STREAM_ID:
{
// Now we know the streamId, we can do the version check
// and if it is wrong, issue a RST_STREAM
try
{
checkVersion(controlFrameParser.getVersion(), streamId);
}
catch (StreamException e)
{
// We've already read 4 bytes of the streamId which are part of controlFrameParser.getLength
// so we need to substract those from the bytesToSkip.
int bytesToSkip = controlFrameParser.getLength() - 4;
int remaining = buffer.remaining();
if (remaining >= bytesToSkip)
{
buffer.position(buffer.position() + bytesToSkip);
controlFrameParser.reset();
reset();
}
else
{
int bytesToSkipInNextBuffer = bytesToSkip - remaining;
buffer.position(buffer.limit());
controlFrameParser.skip(bytesToSkipInNextBuffer);
reset();
}
throw e;
}
if (buffer.remaining() >= 4)
{
associatedStreamId = buffer.getInt() & 0x7F_FF_FF_FF;
state = State.PRIORITY;
}
else
{
state = State.ASSOCIATED_STREAM_ID_BYTES;
cursor = 4;
}
break;
}
case ASSOCIATED_STREAM_ID_BYTES:
{
byte currByte = buffer.get();
--cursor;
associatedStreamId += (currByte & 0xFF) << 8 * cursor;
if (cursor == 0)
{
associatedStreamId &= 0x7F_FF_FF_FF;
state = State.PRIORITY;
}
break;
}
case PRIORITY:
{
byte currByte = buffer.get();
++cursor;
if (cursor == 1)
{
priority = readPriority(controlFrameParser.getVersion(), currByte);
}
else
{
slot = (short)(currByte & 0xFF);
cursor = 0;
state = State.HEADERS;
}
break;
}
case HEADERS:
{
short version = controlFrameParser.getVersion();
int length = controlFrameParser.getLength() - 10;
if (headersBlockParser.parse(streamId, version, length, buffer))
{
byte flags = controlFrameParser.getFlags();
if (flags > (SynInfo.FLAG_CLOSE | PushSynInfo.FLAG_UNIDIRECTIONAL))
throw new IllegalArgumentException("Invalid flag " + flags + " for frame " +
ControlFrameType.SYN_STREAM);
SynStreamFrame frame = new SynStreamFrame(version, flags, streamId, associatedStreamId,
priority, slot, new Fields(headers, false));
controlFrameParser.onControlFrame(frame);
reset();
return true;
}
break;
}
default:
{
throw new IllegalStateException();
}
}
}
return false;
}
private void checkVersion(short version, int streamId)
{
if (version != SPDY.V2 && version != SPDY.V3)
throw new StreamException(streamId, StreamStatus.UNSUPPORTED_VERSION);
}
private byte readPriority(short version, byte currByte)
{
// Right shift retains the sign bit when operated on a byte,
// so we use an int to perform the shifts
switch (version)
{
case SPDY.V2:
int p2 = currByte & 0b1100_0000;
p2 >>>= 6;
return (byte)p2;
case SPDY.V3:
int p3 = currByte & 0b1110_0000;
p3 >>>= 5;
return (byte)p3;
default:
throw new IllegalStateException();
}
}
private void reset()
{
headers.clear();
state = State.STREAM_ID;
cursor = 0;
streamId = 0;
associatedStreamId = 0;
priority = 0;
}
private enum State
{
STREAM_ID, STREAM_ID_BYTES, ASSOCIATED_STREAM_ID, ASSOCIATED_STREAM_ID_BYTES, PRIORITY, HEADERS
}
private class SynStreamHeadersBlockParser extends HeadersBlockParser
{
public SynStreamHeadersBlockParser(CompressionFactory.Decompressor decompressor)
{
super(decompressor);
}
@Override
protected void onHeader(String name, String[] values)
{
for (String value : values)
headers.add(name, value);
}
}
}