org.neo4j.bolt.transport.TransportSelectionHandler.java Source code

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Here is the source code for org.neo4j.bolt.transport.TransportSelectionHandler.java

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/*
 * Copyright (c) 2002-2016 "Neo Technology,"
 * Network Engine for Objects in Lund AB [http://neotechnology.com]
 *
 * This file is part of Neo4j.
 *
 * Neo4j is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
package org.neo4j.bolt.transport;

import io.netty.buffer.ByteBuf;
import io.netty.channel.Channel;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelPipeline;
import io.netty.handler.codec.ByteToMessageDecoder;
import io.netty.handler.codec.http.HttpObjectAggregator;
import io.netty.handler.codec.http.HttpServerCodec;
import io.netty.handler.codec.http.websocketx.WebSocketServerProtocolHandler;
import io.netty.handler.ssl.SslContext;
import io.netty.handler.ssl.SslHandler;

import java.util.List;
import java.util.function.BiFunction;

import org.neo4j.collection.primitive.PrimitiveLongObjectMap;
import org.neo4j.logging.LogProvider;

import static org.neo4j.bolt.transport.SocketTransportHandler.ProtocolChooser.BOLT_MAGIC_PREAMBLE;

public class TransportSelectionHandler extends ByteToMessageDecoder {
    private static final String WEBSOCKET_MAGIC = "GET ";
    private static final int MAX_WEBSOCKET_HANDSHAKE_SIZE = 65536;

    private final SslContext sslCtx;
    private final boolean isEncrypted;
    private final LogProvider logging;
    private final PrimitiveLongObjectMap<BiFunction<Channel, Boolean, BoltProtocol>> protocolVersions;

    public TransportSelectionHandler(SslContext sslCtx, LogProvider logging,
            PrimitiveLongObjectMap<BiFunction<Channel, Boolean, BoltProtocol>> protocolVersions) {
        this(sslCtx, false, logging, protocolVersions);
    }

    private TransportSelectionHandler(SslContext sslCtx, boolean isEncrypted, LogProvider logging,
            PrimitiveLongObjectMap<BiFunction<Channel, Boolean, BoltProtocol>> protocolVersions) {
        this.sslCtx = sslCtx;
        this.isEncrypted = isEncrypted;
        this.logging = logging;
        this.protocolVersions = protocolVersions;
    }

    @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 (detectSsl(in)) {
            enableSsl(ctx);
        } else if (isHttp(in)) {
            switchToWebsocket(ctx);
        } else if (isBoltPreamble(in)) {
            switchToSocket(ctx);
        } else {
            // TODO: send a alert_message for a ssl connection to terminate the handshake
            in.clear();
            ctx.close();
        }
    }

    private boolean isBoltPreamble(ByteBuf in) {
        return in.getInt(0) == BOLT_MAGIC_PREAMBLE;
    }

    private boolean detectSsl(ByteBuf buf) {
        return sslCtx != null && SslHandler.isEncrypted(buf);
    }

    private boolean isHttp(ByteBuf buf) {
        for (int i = 0; i < WEBSOCKET_MAGIC.length(); ++i) {
            if (buf.getUnsignedByte(buf.readerIndex() + i) != WEBSOCKET_MAGIC.charAt(i)) {
                return false;
            }
        }
        return true;
    }

    private void enableSsl(ChannelHandlerContext ctx) {
        ChannelPipeline p = ctx.pipeline();
        p.addLast(sslCtx.newHandler(ctx.alloc()));
        p.addLast(new TransportSelectionHandler(null, true, logging, protocolVersions));
        p.remove(this);
    }

    private void switchToSocket(ChannelHandlerContext ctx) {
        ChannelPipeline p = ctx.pipeline();
        p.addLast(new SocketTransportHandler(
                new SocketTransportHandler.ProtocolChooser(protocolVersions, isEncrypted), logging));
        p.remove(this);
    }

    private void switchToWebsocket(ChannelHandlerContext ctx) {
        ChannelPipeline p = ctx.pipeline();
        p.addLast(new HttpServerCodec(), new HttpObjectAggregator(MAX_WEBSOCKET_HANDSHAKE_SIZE),
                new WebSocketServerProtocolHandler(""), new WebSocketFrameTranslator(), new SocketTransportHandler(
                        new SocketTransportHandler.ProtocolChooser(protocolVersions, isEncrypted), logging));
        p.remove(this);
    }
}