Socks5ServerEncoder Class — netty Architecture

Source Code

codec-socks/src/main/java/io/netty/handler/codec/socksx/v5/Socks5ServerEncoder.java lines 31–101

@Sharable
public class Socks5ServerEncoder extends MessageToByteEncoder<Socks5Message> {

    public static final Socks5ServerEncoder DEFAULT = new Socks5ServerEncoder(Socks5AddressEncoder.DEFAULT);

    private final Socks5AddressEncoder addressEncoder;

    /**
     * Creates a new instance with the default {@link Socks5AddressEncoder}.
     */
    protected Socks5ServerEncoder() {
        this(Socks5AddressEncoder.DEFAULT);
    }

    /**
     * Creates a new instance with the specified {@link Socks5AddressEncoder}.
     */
    public Socks5ServerEncoder(Socks5AddressEncoder addressEncoder) {
        super(Socks5Message.class);
        this.addressEncoder = ObjectUtil.checkNotNull(addressEncoder, "addressEncoder");
    }

    /**
     * Returns the {@link Socks5AddressEncoder} of this encoder.
     */
    protected final Socks5AddressEncoder addressEncoder() {
        return addressEncoder;
    }

    @Override
    protected void encode(ChannelHandlerContext ctx, Socks5Message msg, ByteBuf out) throws Exception {
        if (msg instanceof Socks5InitialResponse) {
            encodeAuthMethodResponse((Socks5InitialResponse) msg, out);
        } else if (msg instanceof Socks5PasswordAuthResponse) {
            encodePasswordAuthResponse((Socks5PasswordAuthResponse) msg, out);
        } else if (msg instanceof Socks5CommandResponse) {
            encodeCommandResponse((Socks5CommandResponse) msg, out);
        } else if (msg instanceof Socks5PrivateAuthResponse) {
            encodePrivateAuthResponse((Socks5PrivateAuthResponse) msg, out);
        } else {
            throw new EncoderException("unsupported message type: " + StringUtil.simpleClassName(msg));
        }
    }

    private static void encodeAuthMethodResponse(Socks5InitialResponse msg, ByteBuf out) {
        out.writeByte(msg.version().byteValue());
        out.writeByte(msg.authMethod().byteValue());
    }

    private static void encodePasswordAuthResponse(Socks5PasswordAuthResponse msg, ByteBuf out) {
        out.writeByte(0x01);
        out.writeByte(msg.status().byteValue());
    }

    private static void encodePrivateAuthResponse(Socks5PrivateAuthResponse msg, ByteBuf out) {
        out.writeByte(0x01);
        out.writeByte(msg.status().byteValue());
    }

    private void encodeCommandResponse(Socks5CommandResponse msg, ByteBuf out) throws Exception {
        out.writeByte(msg.version().byteValue());
        out.writeByte(msg.status().byteValue());
        out.writeByte(0x00);

        final Socks5AddressType bndAddrType = msg.bndAddrType();
        out.writeByte(bndAddrType.byteValue());
        addressEncoder.encodeAddress(bndAddrType, msg.bndAddr(), out);

        ByteBufUtil.writeShortBE(out, msg.bndPort());
    }
}