HandshakePacket.java

/*
 * Copyright 2015 Liu Huanting.
 * 
 * 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 fm.liu.timo.mysql.packet;

import java.nio.ByteBuffer;
import fm.liu.timo.mysql.BufferUtil;
import fm.liu.timo.mysql.MySQLMessage;

/**
 * From server to client during initial handshake.
 * 
 * <pre>
 * Bytes                        Name
 * -----                        ----
 * 1                            protocol_version
 * n (Null-Terminated String)   server_version
 * 4                            thread_id
 * 8                            scramble_buff
 * 1                            (filler) always 0x00
 * 2                            server_capabilities
 * 1                            server_language
 * 2                            server_status
 * 13                           (filler) always 0x00 ...
 * 13                           rest of scramble_buff (4.1)
 * 
 * @see http://forge.mysql.com/wiki/MySQL_Internals_ClientServer_Protocol#Handshake_Initialization_Packet
 * </pre>
 * 
 */
public class HandshakePacket extends MySQLServerPacket {
    private static final byte[] FILLER_13 = new byte[] {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};

    public byte   protocolVersion;
    public byte[] serverVersion;
    public long   threadId;
    public byte[] seed;
    public int    serverCapabilities;
    public byte   serverCharsetIndex;
    public int    serverStatus;
    public byte[] restOfScrambleBuff;

    @Override
    protected void readBody(MySQLMessage mm) {
        protocolVersion = mm.read();
        serverVersion = mm.readBytesWithNull();
        threadId = mm.readUB4();
        seed = mm.readBytesWithNull();
        serverCapabilities = mm.readUB2();
        serverCharsetIndex = mm.read();
        serverStatus = mm.readUB2();
        mm.move(13);
        restOfScrambleBuff = mm.readBytesWithNull();
    }

    @Override
    public int calcPacketSize() {
        int size = 1;
        size += serverVersion.length;// n
        size += 5;// 1+4
        size += seed.length;// 8
        size += 19;// 1+2+1+2+13
        size += restOfScrambleBuff.length;// 12
        size += 1;// 1
        return size;
    }

    @Override
    protected String getPacketInfo() {
        return "MySQL Handshake Packet";
    }

    @Override
    protected void writeBody(ByteBuffer buffer) {
        buffer.put(protocolVersion);
        BufferUtil.writeWithNull(buffer, serverVersion);
        BufferUtil.writeUB4(buffer, threadId);
        BufferUtil.writeWithNull(buffer, seed);
        BufferUtil.writeUB2(buffer, serverCapabilities);
        buffer.put(serverCharsetIndex);
        BufferUtil.writeUB2(buffer, serverStatus);
        buffer.put(FILLER_13);
        // buffer.position(buffer.position() + 13);
        BufferUtil.writeWithNull(buffer, restOfScrambleBuff);
    }

}