Java tutorial
/** * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you 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.apache.pulsar.proxy.server; import java.net.URI; import java.net.URISyntaxException; import javax.net.ssl.SSLSession; import org.apache.http.conn.ssl.DefaultHostnameVerifier; import org.apache.pulsar.client.api.Authentication; import org.apache.pulsar.common.api.Commands; import org.apache.pulsar.common.api.PulsarDecoder; import org.apache.pulsar.common.api.proto.PulsarApi.CommandConnected; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import io.netty.bootstrap.Bootstrap; import io.netty.buffer.ByteBuf; import io.netty.buffer.PooledByteBufAllocator; import io.netty.channel.Channel; import io.netty.channel.ChannelFuture; import io.netty.channel.ChannelHandler; import io.netty.channel.ChannelHandlerContext; import io.netty.channel.ChannelInitializer; import io.netty.channel.ChannelOption; import io.netty.channel.socket.SocketChannel; import io.netty.handler.codec.LengthFieldBasedFrameDecoder; import io.netty.handler.ssl.SslContext; import io.netty.handler.ssl.SslHandler; import io.netty.util.concurrent.Future; import io.netty.util.concurrent.FutureListener; import io.prometheus.client.Counter; public class DirectProxyHandler { private Channel inboundChannel; Channel outboundChannel; private String originalPrincipal; private String clientAuthData; private String clientAuthMethod; private int protocolVersion; public static final String TLS_HANDLER = "tls"; private final Authentication authentication; private final SslContext sslCtx; public DirectProxyHandler(ProxyService service, ProxyConnection proxyConnection, String targetBrokerUrl, int protocolVersion, SslContext sslCtx) { this.authentication = proxyConnection.getClientAuthentication(); this.inboundChannel = proxyConnection.ctx().channel(); this.originalPrincipal = proxyConnection.clientAuthRole; this.clientAuthData = proxyConnection.clientAuthData; this.clientAuthMethod = proxyConnection.clientAuthMethod; this.protocolVersion = protocolVersion; this.sslCtx = sslCtx; ProxyConfiguration config = service.getConfiguration(); // Start the connection attempt. Bootstrap b = new Bootstrap(); // Tie the backend connection on the same thread to avoid context // switches when passing data between the 2 // connections b.option(ChannelOption.ALLOCATOR, PooledByteBufAllocator.DEFAULT); b.group(inboundChannel.eventLoop()).channel(inboundChannel.getClass()).option(ChannelOption.AUTO_READ, false); b.handler(new ChannelInitializer<SocketChannel>() { @Override protected void initChannel(SocketChannel ch) throws Exception { if (sslCtx != null) { ch.pipeline().addLast(TLS_HANDLER, sslCtx.newHandler(ch.alloc())); } ch.pipeline().addLast("frameDecoder", new LengthFieldBasedFrameDecoder(PulsarDecoder.MaxFrameSize, 0, 4, 0, 4)); ch.pipeline().addLast("proxyOutboundHandler", new ProxyBackendHandler(config, protocolVersion)); } }); URI targetBroker; try { // targetBrokerUrl is coming in the "hostname:6650" form, so we need // to extract host and port targetBroker = new URI("pulsar://" + targetBrokerUrl); } catch (URISyntaxException e) { log.warn("[{}] Failed to parse broker url '{}'", inboundChannel, targetBrokerUrl, e); inboundChannel.close(); return; } ChannelFuture f = b.connect(targetBroker.getHost(), targetBroker.getPort()); outboundChannel = f.channel(); f.addListener(future -> { if (!future.isSuccess()) { // Close the connection if the connection attempt has failed. inboundChannel.close(); return; } final ProxyBackendHandler cnx = (ProxyBackendHandler) outboundChannel.pipeline() .get("proxyOutboundHandler"); cnx.setRemoteHostName(targetBroker.getHost()); }); } enum BackendState { Init, HandshakeCompleted } public class ProxyBackendHandler extends PulsarDecoder implements FutureListener<Void> { private BackendState state = BackendState.Init; private String remoteHostName; protected ChannelHandlerContext ctx; private ProxyConfiguration config; private int protocolVersion; public ProxyBackendHandler(ProxyConfiguration config, int protocolVersion) { this.config = config; this.protocolVersion = protocolVersion; } @Override public void channelActive(ChannelHandlerContext ctx) throws Exception { this.ctx = ctx; // Send the Connect command to broker String authData = ""; if (authentication.getAuthData().hasDataFromCommand()) { authData = authentication.getAuthData().getCommandData(); } ByteBuf command = null; command = Commands.newConnect(authentication.getAuthMethodName(), authData, protocolVersion, "Pulsar proxy", null /* target broker */, originalPrincipal, clientAuthData, clientAuthMethod); outboundChannel.writeAndFlush(command); outboundChannel.read(); } @Override public void channelRead(final ChannelHandlerContext ctx, Object msg) throws Exception { switch (state) { case Init: if (log.isDebugEnabled()) { log.debug("[{}] [{}] Received msg on broker connection: {}", inboundChannel, outboundChannel, msg.getClass()); } // Do the regular decoding for the Connected message super.channelRead(ctx, msg); break; case HandshakeCompleted: ProxyService.opsCounter.inc(); if (msg instanceof ByteBuf) { ProxyService.bytesCounter.inc(((ByteBuf) msg).readableBytes()); } inboundChannel.writeAndFlush(msg).addListener(this); break; default: break; } } @Override public void operationComplete(Future<Void> future) throws Exception { // This is invoked when the write operation on the paired connection // is completed if (future.isSuccess()) { outboundChannel.read(); } else { log.warn("[{}] [{}] Failed to write on proxy connection. Closing both connections.", inboundChannel, outboundChannel, future.cause()); inboundChannel.close(); } } @Override protected void messageReceived() { // no-op } @Override protected void handleConnected(CommandConnected connected) { if (log.isDebugEnabled()) { log.debug("[{}] [{}] Received Connected from broker", inboundChannel, outboundChannel); } if (config.isTlsHostnameVerificationEnabled() && remoteHostName != null && !verifyTlsHostName(remoteHostName, ctx)) { // close the connection if host-verification failed with the // broker log.warn("[{}] Failed to verify hostname of {}", ctx.channel(), remoteHostName); ctx.close(); return; } state = BackendState.HandshakeCompleted; inboundChannel.writeAndFlush(Commands.newConnected(connected.getProtocolVersion())) .addListener(future -> { if (log.isDebugEnabled()) { log.debug("[{}] [{}] Removing decoder from pipeline", inboundChannel, outboundChannel); } inboundChannel.pipeline().remove("frameDecoder"); outboundChannel.pipeline().remove("frameDecoder"); // Start reading from both connections inboundChannel.read(); outboundChannel.read(); }); } @Override public void channelInactive(ChannelHandlerContext ctx) { inboundChannel.close(); } @Override public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) { log.warn("[{}] [{}] Caught exception: {}", inboundChannel, outboundChannel, cause.getMessage(), cause); ctx.close(); } public void setRemoteHostName(String remoteHostName) { this.remoteHostName = remoteHostName; } private boolean verifyTlsHostName(String hostname, ChannelHandlerContext ctx) { ChannelHandler sslHandler = ctx.channel().pipeline().get("tls"); SSLSession sslSession = null; if (sslHandler != null) { sslSession = ((SslHandler) sslHandler).engine().getSession(); return (new DefaultHostnameVerifier()).verify(hostname, sslSession); } return false; } } private static final Logger log = LoggerFactory.getLogger(DirectProxyHandler.class); }