/*
* Copyright 2014 Netflix, Inc.
*
* 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 io.reactivex.netty.protocol.http.websocket;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelFutureListener;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.ChannelPromise;
import io.netty.channel.SimpleChannelInboundHandler;
import io.netty.handler.codec.http.DefaultFullHttpResponse;
import io.netty.handler.codec.http.FullHttpRequest;
import io.netty.handler.codec.http.FullHttpResponse;
import io.netty.handler.codec.http.websocketx.WebSocketFrameAggregator;
import io.netty.handler.codec.http.websocketx.WebSocketFrameDecoder;
import io.netty.handler.codec.http.websocketx.WebSocketFrameEncoder;
import io.netty.handler.codec.http.websocketx.WebSocketServerHandshaker;
import io.netty.handler.codec.http.websocketx.WebSocketServerHandshakerFactory;
import io.netty.util.CharsetUtil;
import io.reactivex.netty.metrics.MetricEventsSubject;
import io.reactivex.netty.protocol.http.websocket.WebSocketServerMetricsHandlers.ServerReadMetricsHandler;
import io.reactivex.netty.protocol.http.websocket.WebSocketServerMetricsHandlers.ServerWriteMetricsHandler;
import io.reactivex.netty.server.ServerMetricsEvent;
import static io.netty.handler.codec.http.HttpHeaders.isKeepAlive;
import static io.netty.handler.codec.http.HttpHeaders.setContentLength;
import static io.netty.handler.codec.http.HttpMethod.GET;
import static io.netty.handler.codec.http.HttpResponseStatus.BAD_REQUEST;
import static io.netty.handler.codec.http.HttpResponseStatus.FORBIDDEN;
import static io.netty.handler.codec.http.HttpVersion.HTTP_1_1;
/**
* {@link WebSocketServerHandler} orchestrates WebSocket handshake process and reconfigures
* pipeline after the handshake is complete.
*
* @author Tomasz Bak
*/
public class WebSocketServerHandler extends SimpleChannelInboundHandler<Object> {
private final WebSocketServerHandshakerFactory handshakeHandlerFactory;
private ChannelPromise handshakeFuture;
private final int maxFramePayloadLength;
private final boolean messageAggregator;
private final MetricEventsSubject<ServerMetricsEvent<?>> eventsSubject;
public WebSocketServerHandler(WebSocketServerHandshakerFactory handshakeHandlerFactory,
int maxFramePayloadLength,
boolean messageAggregator,
MetricEventsSubject<ServerMetricsEvent<?>> eventsSubject) {
this.handshakeHandlerFactory = handshakeHandlerFactory;
this.maxFramePayloadLength = maxFramePayloadLength;
this.messageAggregator = messageAggregator;
this.eventsSubject = eventsSubject;
}
public void addHandshakeFinishedListener(ChannelFutureListener listener) {
handshakeFuture.addListener(listener);
}
@Override
public void handlerAdded(ChannelHandlerContext ctx) {
handshakeFuture = ctx.newPromise();
}
@Override
public void channelRead0(ChannelHandlerContext ctx, Object msg) throws Exception {
if (msg instanceof FullHttpRequest) {
ChannelFuture upgradeFuture = handleHttpRequest(ctx, (FullHttpRequest) msg);
if (upgradeFuture != null) {
updatePipeline(ctx);
upgradeFuture.addListener(new ChannelFutureListener() {
@Override
public void operationComplete(ChannelFuture future) throws Exception {
if (future.isSuccess()) {
handshakeFuture.setSuccess();
eventsSubject.onEvent(WebSocketServerMetricsEvent.HANDSHAKE_PROCESSED);
} else {
handshakeFuture.setFailure(future.cause());
eventsSubject.onEvent(WebSocketServerMetricsEvent.HANDSHAKE_FAILURE);
}
}
});
}
} else {
ctx.fireChannelRead(msg);
}
}
private void updatePipeline(ChannelHandlerContext ctx) {
ChannelPipeline p = ctx.pipeline();
ChannelHandlerContext nettyEncoderCtx = p.context(WebSocketFrameEncoder.class);
p.addAfter(nettyEncoderCtx.name(), "websocket-write-metrics", new ServerWriteMetricsHandler(eventsSubject));
ChannelHandlerContext nettyDecoderCtx = p.context(WebSocketFrameDecoder.class);
p.addAfter(nettyDecoderCtx.name(), "websocket-read-metrics", new ServerReadMetricsHandler(eventsSubject));
if (messageAggregator) {
p.addAfter("websocket-read-metrics", "websocket-frame-aggregator", new WebSocketFrameAggregator(maxFramePayloadLength));
}
p.remove(this);
}
@Override
public void channelReadComplete(ChannelHandlerContext ctx) {
ctx.flush();
}
private ChannelFuture handleHttpRequest(ChannelHandlerContext ctx, FullHttpRequest req) {
// Handle a bad request.
if (!req.getDecoderResult().isSuccess()) {
sendHttpResponse(ctx, req, new DefaultFullHttpResponse(HTTP_1_1, BAD_REQUEST));
eventsSubject.onEvent(WebSocketServerMetricsEvent.HANDSHAKE_FAILURE);
return null;
}
// Allow only GET methods.
if (req.getMethod() != GET) {
sendHttpResponse(ctx, req, new DefaultFullHttpResponse(HTTP_1_1, FORBIDDEN));
eventsSubject.onEvent(WebSocketServerMetricsEvent.HANDSHAKE_FAILURE);
return null;
}
// Handshake
WebSocketServerHandshaker handshaker = handshakeHandlerFactory.newHandshaker(req);
if (handshaker == null) {
WebSocketServerHandshakerFactory.sendUnsupportedVersionResponse(ctx.channel());
return null;
}
return handshaker.handshake(ctx.channel(), req);
}
private static void sendHttpResponse(
ChannelHandlerContext ctx, FullHttpRequest req, FullHttpResponse res) {
// Generate an error page if response getStatus code is not OK (200).
if (res.getStatus().code() != 200) {
ByteBuf buf = Unpooled.copiedBuffer(res.getStatus().toString(), CharsetUtil.UTF_8);
res.content().writeBytes(buf);
buf.release();
setContentLength(res, res.content().readableBytes());
}
// Send the response and close the connection if necessary.
ChannelFuture f = ctx.channel().writeAndFlush(res);
if (!isKeepAlive(req) || res.getStatus().code() != 200) {
f.addListener(ChannelFutureListener.CLOSE);
}
}
}