PortUnificationServerHandler Class — netty Architecture

Source Code

example/src/main/java/io/netty/example/portunification/PortUnificationServerHandler.java lines 41–147

public class PortUnificationServerHandler extends ByteToMessageDecoder {

    private static final int MAX_CONTENT_LENGTH = 65536;

    private final SslContext sslCtx;
    private final boolean detectSsl;
    private final boolean detectGzip;

    public PortUnificationServerHandler(SslContext sslCtx) {
        this(sslCtx, true, true);
    }

    private PortUnificationServerHandler(SslContext sslCtx, boolean detectSsl, boolean detectGzip) {
        this.sslCtx = sslCtx;
        this.detectSsl = detectSsl;
        this.detectGzip = detectGzip;
    }

    @Override
    protected void decode(ChannelHandlerContext ctx, ByteBuf in, List<Object> out) throws Exception {
        // Will use the first five bytes to detect a protocol.
        if (in.readableBytes() < 5) {
            return;
        }

        if (isSsl(in)) {
            enableSsl(ctx);
        } else {
            final int magic1 = in.getUnsignedByte(in.readerIndex());
            final int magic2 = in.getUnsignedByte(in.readerIndex() + 1);
            if (isGzip(magic1, magic2)) {
                enableGzip(ctx);
            } else if (isHttp(magic1, magic2)) {
                switchToHttp(ctx);
            } else if (isFactorial(magic1)) {
                switchToFactorial(ctx);
            } else {
                // Unknown protocol; discard everything and close the connection.
                in.clear();
                ctx.close();
            }
        }
    }

    private boolean isSsl(ByteBuf buf) {
        if (detectSsl) {
            return SslHandler.isEncrypted(buf, false);
        }
        return false;
    }

    private boolean isGzip(int magic1, int magic2) {
        if (detectGzip) {
            return magic1 == 31 && magic2 == 139;
        }
        return false;
    }

    private static boolean isHttp(int magic1, int magic2) {
        return
            magic1 == 'G' && magic2 == 'E' || // GET
            magic1 == 'P' && magic2 == 'O' || // POST
            magic1 == 'P' && magic2 == 'U' || // PUT
            magic1 == 'H' && magic2 == 'E' || // HEAD
            magic1 == 'O' && magic2 == 'P' || // OPTIONS
            magic1 == 'P' && magic2 == 'A' || // PATCH
            magic1 == 'D' && magic2 == 'E' || // DELETE
            magic1 == 'T' && magic2 == 'R' || // TRACE
            magic1 == 'C' && magic2 == 'O';   // CONNECT
    }

    private static boolean isFactorial(int magic1) {
        return magic1 == 'F';
    }

    private void enableSsl(ChannelHandlerContext ctx) {
        ChannelPipeline p = ctx.pipeline();
        p.addLast("ssl", sslCtx.newHandler(ctx.alloc()));
        p.addLast("unificationA", new PortUnificationServerHandler(sslCtx, false, detectGzip));
        p.remove(this);
    }