All Downloads are FREE. Search and download functionalities are using the official Maven repository.

io.netty.handler.codec.http.websocketx.WebSocket00FrameDecoder Maven / Gradle / Ivy

Go to download

This artifact provides a single jar that contains all classes required to use remote EJB and JMS, including all dependencies. It is intended for use by those not using maven, maven users should just import the EJB and JMS BOM's instead (shaded JAR's cause lots of problems with maven, as it is very easy to inadvertently end up with different versions on classes on the class path).

There is a newer version: 34.0.0.Final
Show newest version
/*
 * Copyright 2019 The Netty Project
 *
 * The Netty Project 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:
 *
 *   https://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 io.netty.handler.codec.http.websocketx;

import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.ReplayingDecoder;
import io.netty.handler.codec.TooLongFrameException;
import io.netty.util.internal.ObjectUtil;

import java.util.List;

import static io.netty.buffer.ByteBufUtil.readBytes;

/**
 * Decodes {@link ByteBuf}s into {@link WebSocketFrame}s.
 * 

 * For the detailed instruction on adding add Web Socket support to your HTTP server, take a look into the
 * WebSocketServer example located in the {@code io.netty.example.http.websocket} package.
 */
public class WebSocket00FrameDecoder extends ReplayingDecoder implements WebSocketFrameDecoder {

    static final int DEFAULT_MAX_FRAME_SIZE = 16384;

    private final long maxFrameSize;
    private boolean receivedClosingHandshake;

    public WebSocket00FrameDecoder() {
        this(DEFAULT_MAX_FRAME_SIZE);
    }

    /**
     * Creates a new instance of {@code WebSocketFrameDecoder} with the specified {@code maxFrameSize}. If the client
     * sends a frame size larger than {@code maxFrameSize}, the channel will be closed.
     *
     * @param maxFrameSize
     *            the maximum frame size to decode
     */
    public WebSocket00FrameDecoder(int maxFrameSize) {
        this.maxFrameSize = maxFrameSize;
    }

    /**
     * Creates a new instance of {@code WebSocketFrameDecoder} with the specified {@code maxFrameSize}. If the client
     * sends a frame size larger than {@code maxFrameSize}, the channel will be closed.
     *
     * @param decoderConfig
     *            Frames decoder configuration.
     */
    public WebSocket00FrameDecoder(WebSocketDecoderConfig decoderConfig) {
        this.maxFrameSize = ObjectUtil.checkNotNull(decoderConfig, "decoderConfig").maxFramePayloadLength();
    }

    @Override
    protected void decode(ChannelHandlerContext ctx, ByteBuf in, List out) throws Exception {
        // Discard all data received if closing handshake was received before.
        if (receivedClosingHandshake) {
            in.skipBytes(actualReadableBytes());
            return;
        }

        // Decode a frame otherwise.
        byte type = in.readByte();
        WebSocketFrame frame;
        if ((type & 0x80) == 0x80) {
            // If the MSB on type is set, decode the frame length
            frame = decodeBinaryFrame(ctx, type, in);
        } else {
            // Decode a 0xff terminated UTF-8 string
            frame = decodeTextFrame(ctx, in);
        }

        if (frame != null) {
            out.add(frame);
        }
    }

    private WebSocketFrame decodeBinaryFrame(ChannelHandlerContext ctx, byte type, ByteBuf buffer) {
        long frameSize = 0;
        int lengthFieldSize = 0;
        byte b;
        do {
            b = buffer.readByte();
            frameSize <<= 7;
            frameSize |= b & 0x7f;
            if (frameSize > maxFrameSize) {
                throw new TooLongFrameException();
            }
            lengthFieldSize++;
            if (lengthFieldSize > 8) {
                // Perhaps a malicious peer?
                throw new TooLongFrameException();
            }
        } while ((b & 0x80) == 0x80);

        if (type == (byte) 0xFF && frameSize == 0) {
            receivedClosingHandshake = true;
            return new CloseWebSocketFrame(true, 0, ctx.alloc().buffer(0));
        }
        ByteBuf payload = readBytes(ctx.alloc(), buffer, (int) frameSize);
        return new BinaryWebSocketFrame(payload);
    }

    private WebSocketFrame decodeTextFrame(ChannelHandlerContext ctx, ByteBuf buffer) {
        int ridx = buffer.readerIndex();
        int rbytes = actualReadableBytes();
        int delimPos = buffer.indexOf(ridx, ridx + rbytes, (byte) 0xFF);
        if (delimPos == -1) {
            // Frame delimiter (0xFF) not found
            if (rbytes > maxFrameSize) {
                // Frame length exceeded the maximum
                throw new TooLongFrameException();
            } else {
                // Wait until more data is received
                return null;
            }
        }

        int frameSize = delimPos - ridx;
        if (frameSize > maxFrameSize) {
            throw new TooLongFrameException();
        }

        ByteBuf binaryData = readBytes(ctx.alloc(), buffer, frameSize);
        buffer.skipBytes(1);

        int ffDelimPos = binaryData.indexOf(binaryData.readerIndex(), binaryData.writerIndex(), (byte) 0xFF);
        if (ffDelimPos >= 0) {
            binaryData.release();
            throw new IllegalArgumentException("a text frame should not contain 0xFF.");
        }

        return new TextWebSocketFrame(binaryData);
    }
}
    

    

    

            

    

            



    
    






    
© 2015 - 2024 Weber Informatics LLC | Privacy Policy