org.jfxvnc.net.rfb.codec.handshaker.RfbClient38Decoder.java Source code

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Here is the source code for org.jfxvnc.net.rfb.codec.handshaker.RfbClient38Decoder.java

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/*******************************************************************************
 * Copyright (c) 2016 comtel inc.
 *
 * Licensed 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:
 *
 * http://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 org.jfxvnc.net.rfb.codec.handshaker;

import java.nio.charset.Charset;
import java.nio.charset.StandardCharsets;
import java.util.Arrays;
import java.util.List;

import org.jfxvnc.net.rfb.codec.PixelFormat;
import org.jfxvnc.net.rfb.codec.handshaker.event.SecurityResultEvent;
import org.jfxvnc.net.rfb.codec.handshaker.event.SecurityTypesEvent;
import org.jfxvnc.net.rfb.codec.handshaker.event.ServerInitEvent;
import org.jfxvnc.net.rfb.codec.security.SecurityType;
import org.jfxvnc.net.rfb.exception.ProtocolException;
import org.jfxvnc.net.rfb.exception.SecurityException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.ReplayingDecoder;

class RfbClient38Decoder extends ReplayingDecoder<RfbClient38Decoder.State> implements RfbClientDecoder {

    private static Logger logger = LoggerFactory.getLogger(RfbClient38Decoder.class);

    protected final Charset ASCII = StandardCharsets.US_ASCII;

    public RfbClient38Decoder() {
        super(State.SEC_TYPES);
    }

    enum State {
        SEC_TYPES, SEC_AUTH, SEC_RESULT, SERVER_INIT
    }

    @Override
    protected void decode(ChannelHandlerContext ctx, ByteBuf in, List<Object> out) throws Exception {
        switch (state()) {
        case SEC_TYPES:
            int numberOfSecurtiyTypes = in.readUnsignedByte();
            if (numberOfSecurtiyTypes == 0) {
                logger.error("no security types available");
                decodeErrorMessage(ctx, in);
                return;
            }
            SecurityType[] serverSecTypes = new SecurityType[numberOfSecurtiyTypes];
            for (int i = 0; i < numberOfSecurtiyTypes; i++) {
                int sec = in.readUnsignedByte();
                serverSecTypes[i] = SecurityType.valueOf(sec);
                if (serverSecTypes[i] == SecurityType.UNKNOWN) {
                    logger.error("un supported security types: {}", sec);
                }
            }
            logger.debug("supported security types: {}", Arrays.toString(serverSecTypes));
            checkpoint(State.SEC_RESULT);
            out.add(new SecurityTypesEvent(true, serverSecTypes));
            break;
        case SEC_RESULT:

            int secResult = in.readInt();
            logger.debug("server login {}", secResult == 0 ? "succeed" : "failed");
            if (secResult == 1) {
                int length = in.readInt();
                if (length == 0) {
                    out.add(new SecurityResultEvent(false, new ProtocolException("decode error message failed")));
                    return;
                }
                byte[] text = new byte[length];
                in.readBytes(text);
                out.add(new SecurityResultEvent(false, new SecurityException(new String(text, ASCII))));
                return;
            }
            out.add(new SecurityResultEvent(true));
            checkpoint(State.SERVER_INIT);
            break;
        case SERVER_INIT:
            ServerInitEvent initMsg = new ServerInitEvent();

            initMsg.setFrameBufferWidth(in.readUnsignedShort());
            initMsg.setFrameBufferHeight(in.readUnsignedShort());

            initMsg.setPixelFormat(parsePixelFormat(in));

            byte[] name = new byte[in.readInt()];
            in.readBytes(name);

            initMsg.setServerName(new String(name, ASCII));
            out.add(initMsg);
            break;
        default:
            break;

        }
    }

    private void decodeErrorMessage(ChannelHandlerContext ctx, ByteBuf in) {

        int length = in.readInt();
        if (length == 0) {
            ctx.fireExceptionCaught(new ProtocolException("decode error message failed"));
            return;
        }
        byte[] text = new byte[length];
        in.readBytes(text);
        ctx.fireExceptionCaught(new ProtocolException(new String(text, ASCII)));
    }

    private PixelFormat parsePixelFormat(ByteBuf m) {

        PixelFormat pf = new PixelFormat();

        pf.setBitPerPixel(m.readUnsignedByte());
        pf.setDepth(m.readUnsignedByte());
        pf.setBigEndian(m.readUnsignedByte() == 1);
        pf.setTrueColor(m.readUnsignedByte() == 1);
        pf.setRedMax(m.readUnsignedShort());
        pf.setGreenMax(m.readUnsignedShort());
        pf.setBlueMax(m.readUnsignedShort());

        pf.setRedShift(m.readUnsignedByte());
        pf.setGreenShift(m.readUnsignedByte());
        pf.setBlueShift(m.readUnsignedByte());
        m.skipBytes(3);

        return pf;
    }

}