org.eclipse.jetty.websocket.common.Parser Maven / Gradle / Ivy
//
// ========================================================================
// Copyright (c) 1995-2013 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.websocket.common;
import java.nio.ByteBuffer;
import java.util.List;
import org.eclipse.jetty.io.ByteBufferPool;
import org.eclipse.jetty.util.BufferUtil;
import org.eclipse.jetty.util.log.Log;
import org.eclipse.jetty.util.log.Logger;
import org.eclipse.jetty.websocket.api.MessageTooLargeException;
import org.eclipse.jetty.websocket.api.ProtocolException;
import org.eclipse.jetty.websocket.api.WebSocketBehavior;
import org.eclipse.jetty.websocket.api.WebSocketException;
import org.eclipse.jetty.websocket.api.WebSocketPolicy;
import org.eclipse.jetty.websocket.api.extensions.Extension;
import org.eclipse.jetty.websocket.api.extensions.Frame;
import org.eclipse.jetty.websocket.api.extensions.IncomingFrames;
import org.eclipse.jetty.websocket.common.io.payload.CloseReasonValidator;
import org.eclipse.jetty.websocket.common.io.payload.DeMaskProcessor;
import org.eclipse.jetty.websocket.common.io.payload.NoOpValidator;
import org.eclipse.jetty.websocket.common.io.payload.PayloadProcessor;
import org.eclipse.jetty.websocket.common.io.payload.UTF8Validator;
/**
* Parsing of a frames in WebSocket land.
*/
public class Parser
{
private enum State
{
START,
FINOP,
PAYLOAD_LEN,
PAYLOAD_LEN_BYTES,
MASK,
MASK_BYTES,
PAYLOAD
}
private static final Logger LOG = Log.getLogger(Parser.class);
private final WebSocketPolicy policy;
private final ByteBufferPool bufferPool;
// State specific
private State state = State.START;
private int cursor = 0;
// Frame
private WebSocketFrame frame;
private Frame priorDataFrame;
private byte lastDataOpcode;
// payload specific
private ByteBuffer payload;
private int payloadLength;
private PayloadProcessor maskProcessor = new DeMaskProcessor();
private PayloadProcessor strictnessProcessor;
/** Is there an extension using RSV1 */
private boolean rsv1InUse = false;
/** Is there an extension using RSV2 */
private boolean rsv2InUse = false;
/** Is there an extension using RSV3 */
private boolean rsv3InUse = false;
/** Is there an extension that processes invalid UTF8 text messages (such as compressed content) */
private boolean isTextFrameValidated = true;
private IncomingFrames incomingFramesHandler;
public Parser(WebSocketPolicy wspolicy, ByteBufferPool bufferPool)
{
this.bufferPool = bufferPool;
this.policy = wspolicy;
}
private void assertSanePayloadLength(long len)
{
LOG.debug("Payload Length: " + len);
// Since we use ByteBuffer so often, having lengths over Integer.MAX_VALUE is really impossible.
if (len > Integer.MAX_VALUE)
{
// OMG! Sanity Check! DO NOT WANT! Won't anyone think of the memory!
throw new MessageTooLargeException("[int-sane!] cannot handle payload lengths larger than " + Integer.MAX_VALUE);
}
policy.assertValidMessageSize((int)len);
switch (frame.getOpCode())
{
case OpCode.CLOSE:
if (len == 1)
{
throw new ProtocolException("Invalid close frame payload length, [" + payloadLength + "]");
}
// fall thru
case OpCode.PING:
case OpCode.PONG:
if (len > WebSocketFrame.MAX_CONTROL_PAYLOAD)
{
throw new ProtocolException("Invalid control frame payload length, [" + payloadLength + "] cannot exceed ["
+ WebSocketFrame.MAX_CONTROL_PAYLOAD + "]");
}
break;
}
}
public void configureFromExtensions(List exts)
{
// default
this.rsv1InUse = false;
this.rsv2InUse = false;
this.rsv3InUse = false;
this.isTextFrameValidated = true;
// configure from list of extensions in use
for (Extension ext : exts)
{
if (ext.isRsv1User())
{
this.rsv1InUse = true;
}
if (ext.isRsv2User())
{
this.rsv2InUse = true;
}
if (ext.isRsv3User())
{
this.rsv3InUse = true;
}
if (ext.isTextDataDecoder())
{
this.isTextFrameValidated = false;
}
}
}
public IncomingFrames getIncomingFramesHandler()
{
return incomingFramesHandler;
}
public WebSocketPolicy getPolicy()
{
return policy;
}
public boolean isRsv1InUse()
{
return rsv1InUse;
}
public boolean isRsv2InUse()
{
return rsv2InUse;
}
public boolean isRsv3InUse()
{
return rsv3InUse;
}
protected void notifyFrame(final Frame f)
{
if (LOG.isDebugEnabled())
{
LOG.debug("{} Notify {}",policy.getBehavior(),incomingFramesHandler);
}
if (policy.getBehavior() == WebSocketBehavior.SERVER)
{
// Parsing on server?
// Then you MUST make sure all incoming frames are masked!
if (f.isMasked() == false)
{
throw new ProtocolException("Client frames MUST be masked (RFC-6455)");
}
}
if (incomingFramesHandler == null)
{
return;
}
try
{
incomingFramesHandler.incomingFrame(f);
}
catch (WebSocketException e)
{
notifyWebSocketException(e);
}
catch (Throwable t)
{
LOG.warn(t);
notifyWebSocketException(new WebSocketException(t));
}
}
protected void notifyWebSocketException(WebSocketException e)
{
LOG.warn(e);
if (incomingFramesHandler == null)
{
return;
}
incomingFramesHandler.incomingError(e);
}
public synchronized void parse(ByteBuffer buffer)
{
if (buffer.remaining() <= 0)
{
return;
}
try
{
// TODO: create DebugBuffer
// parse through all the frames in the buffer
while (parseFrame(buffer))
{
LOG.debug("{} Parsed Frame: {}",policy.getBehavior(),frame);
notifyFrame(frame);
if (frame.isDataFrame() && frame.isFin())
{
priorDataFrame = null;
}
else
{
priorDataFrame = frame;
}
}
}
catch (WebSocketException e)
{
buffer.position(buffer.limit()); // consume remaining
this.payload = null; // reset
notifyWebSocketException(e);
}
catch (Throwable t)
{
buffer.position(buffer.limit()); // consume remaining
this.payload = null; // reset
notifyWebSocketException(new WebSocketException(t));
}
}
/**
* Parse the base framing protocol buffer.
*
* Note the first byte (fin,rsv1,rsv2,rsv3,opcode) are parsed by the {@link Parser#parse(ByteBuffer)} method
*
* Not overridable
*
* @param buffer
* the buffer to parse from.
* @return true if done parsing base framing protocol and ready for parsing of the payload. false if incomplete parsing of base framing protocol.
*/
private boolean parseFrame(ByteBuffer buffer)
{
if (buffer.remaining() <= 0)
{
return false;
}
LOG.debug("{} Parsing {} bytes",policy.getBehavior(),buffer.remaining());
while (buffer.hasRemaining())
{
switch (state)
{
case START:
{
if ((frame != null) && (frame.isFin()))
{
frame.reset();
}
state = State.FINOP;
break;
}
case FINOP:
{
// peek at byte
byte b = buffer.get();
boolean fin = ((b & 0x80) != 0);
boolean rsv1 = ((b & 0x40) != 0);
boolean rsv2 = ((b & 0x20) != 0);
boolean rsv3 = ((b & 0x10) != 0);
byte opc = (byte)(b & 0x0F);
byte opcode = opc;
if (!OpCode.isKnown(opcode))
{
throw new ProtocolException("Unknown opcode: " + opc);
}
if (LOG.isDebugEnabled())
{
LOG.debug("OpCode {}, fin={} rsv={}{}{}",OpCode.name(opcode),fin,(rsv1?'1':'.'),(rsv2?'1':'.'),(rsv3?'1':'.'));
}
/*
* RFC 6455 Section 5.2
*
* MUST be 0 unless an extension is negotiated that defines meanings for non-zero values. If a nonzero value is received and none of the
* negotiated extensions defines the meaning of such a nonzero value, the receiving endpoint MUST _Fail the WebSocket Connection_.
*/
if (!rsv1InUse && rsv1)
{
throw new ProtocolException("RSV1 not allowed to be set");
}
if (!rsv2InUse && rsv2)
{
throw new ProtocolException("RSV2 not allowed to be set");
}
if (!rsv3InUse && rsv3)
{
throw new ProtocolException("RSV3 not allowed to be set");
}
boolean isContinuation = false;
switch (opcode)
{
case OpCode.TEXT:
if (isTextFrameValidated)
{
strictnessProcessor = new UTF8Validator();
}
else
{
strictnessProcessor = NoOpValidator.INSTANCE;
}
break;
case OpCode.CLOSE:
strictnessProcessor = new CloseReasonValidator();
break;
default:
strictnessProcessor = NoOpValidator.INSTANCE;
break;
}
if (OpCode.isControlFrame(opcode))
{
// control frame validation
if (!fin)
{
throw new ProtocolException("Fragmented Control Frame [" + OpCode.name(opcode) + "]");
}
}
else if (opcode == OpCode.CONTINUATION)
{
isContinuation = true;
// continuation validation
if (priorDataFrame == null)
{
throw new ProtocolException("CONTINUATION frame without prior !FIN");
}
// Be careful to use the original opcode
opcode = lastDataOpcode;
}
else if (OpCode.isDataFrame(opcode))
{
// data validation
if ((priorDataFrame != null) && (!priorDataFrame.isFin()))
{
throw new ProtocolException("Unexpected " + OpCode.name(opcode) + " frame, was expecting CONTINUATION");
}
}
// base framing flags
frame = new WebSocketFrame(opcode);
frame.setFin(fin);
frame.setRsv1(rsv1);
frame.setRsv2(rsv2);
frame.setRsv3(rsv3);
frame.setContinuation(isContinuation);
if (frame.isDataFrame())
{
lastDataOpcode = opcode;
}
state = State.PAYLOAD_LEN;
break;
}
case PAYLOAD_LEN:
{
byte b = buffer.get();
frame.setMasked((b & 0x80) != 0);
payloadLength = (byte)(0x7F & b);
if (payloadLength == 127) // 0x7F
{
// length 8 bytes (extended payload length)
payloadLength = 0;
state = State.PAYLOAD_LEN_BYTES;
cursor = 8;
break; // continue onto next state
}
else if (payloadLength == 126) // 0x7E
{
// length 2 bytes (extended payload length)
payloadLength = 0;
state = State.PAYLOAD_LEN_BYTES;
cursor = 2;
break; // continue onto next state
}
assertSanePayloadLength(payloadLength);
if (frame.isMasked())
{
state = State.MASK;
}
else
{
// special case for empty payloads (no more bytes left in buffer)
if (payloadLength == 0)
{
state = State.START;
return true;
}
maskProcessor.reset(frame);
state = State.PAYLOAD;
}
break;
}
case PAYLOAD_LEN_BYTES:
{
byte b = buffer.get();
--cursor;
payloadLength |= (b & 0xFF) << (8 * cursor);
if (cursor == 0)
{
assertSanePayloadLength(payloadLength);
if (frame.isMasked())
{
state = State.MASK;
}
else
{
// special case for empty payloads (no more bytes left in buffer)
if (payloadLength == 0)
{
state = State.START;
return true;
}
maskProcessor.reset(frame);
state = State.PAYLOAD;
}
}
break;
}
case MASK:
{
byte m[] = new byte[4];
frame.setMask(m);
if (buffer.remaining() >= 4)
{
buffer.get(m,0,4);
// special case for empty payloads (no more bytes left in buffer)
if (payloadLength == 0)
{
state = State.START;
return true;
}
maskProcessor.reset(frame);
state = State.PAYLOAD;
}
else
{
state = State.MASK_BYTES;
cursor = 4;
}
break;
}
case MASK_BYTES:
{
byte b = buffer.get();
frame.getMask()[4 - cursor] = b;
--cursor;
if (cursor == 0)
{
// special case for empty payloads (no more bytes left in buffer)
if (payloadLength == 0)
{
state = State.START;
return true;
}
maskProcessor.reset(frame);
state = State.PAYLOAD;
}
break;
}
case PAYLOAD:
{
if (parsePayload(buffer))
{
// special check for close
if (frame.getOpCode() == OpCode.CLOSE)
{
new CloseInfo(frame);
}
state = State.START;
// we have a frame!
return true;
}
break;
}
}
}
return false;
}
/**
* Implementation specific parsing of a payload
*
* @param buffer
* the payload buffer
* @return true if payload is done reading, false if incomplete
*/
private boolean parsePayload(ByteBuffer buffer)
{
if (payloadLength == 0)
{
return true;
}
while (buffer.hasRemaining())
{
if (payload == null)
{
frame.assertValid();
payload = bufferPool.acquire(payloadLength,true);
BufferUtil.clearToFill(payload);
}
// Create a small window of the incoming buffer to work with.
// this should only show the payload itself, and not any more
// bytes that could belong to the start of the next frame.
ByteBuffer window = buffer.slice();
int bytesExpected = payloadLength - payload.position();
int bytesAvailable = buffer.remaining();
int windowBytes = Math.min(bytesAvailable,bytesExpected);
window.limit(window.position() + windowBytes);
if (LOG.isDebugEnabled())
{
LOG.debug("Window: {}",BufferUtil.toDetailString(window));
}
maskProcessor.process(window);
strictnessProcessor.process(window);
int len = BufferUtil.put(window,payload);
buffer.position(buffer.position() + len); // update incoming buffer position
if (payload.position() >= payloadLength)
{
BufferUtil.flipToFlush(payload,0);
frame.setPayload(payload);
this.payload = null;
return true;
}
}
return false;
}
public void setIncomingFramesHandler(IncomingFrames incoming)
{
this.incomingFramesHandler = incoming;
}
@Override
public String toString()
{
StringBuilder builder = new StringBuilder();
builder.append("Parser[");
if (incomingFramesHandler == null)
{
builder.append("NO_HANDLER");
}
else
{
builder.append(incomingFramesHandler.getClass().getSimpleName());
}
builder.append(",s=");
builder.append(state);
builder.append(",c=");
builder.append(cursor);
builder.append(",len=");
builder.append(payloadLength);
builder.append(",f=");
builder.append(frame);
builder.append("]");
return builder.toString();
}
}