/*
* 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.activemq.artemis.core.server.protocol.websocket;
import java.nio.charset.StandardCharsets;
import java.util.List;
import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelFutureListener;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelOutboundHandlerAdapter;
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.HttpHeaders;
import io.netty.handler.codec.http.HttpRequest;
import io.netty.handler.codec.http.websocketx.BinaryWebSocketFrame;
import io.netty.handler.codec.http.websocketx.CloseWebSocketFrame;
import io.netty.handler.codec.http.websocketx.PingWebSocketFrame;
import io.netty.handler.codec.http.websocketx.PongWebSocketFrame;
import io.netty.handler.codec.http.websocketx.TextWebSocketFrame;
import io.netty.handler.codec.http.websocketx.WebSocketFrame;
import io.netty.handler.codec.http.websocketx.WebSocketServerHandshaker;
import io.netty.handler.codec.http.websocketx.WebSocketServerHandshakerFactory;
import org.apache.activemq.artemis.utils.StringUtil;
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.FORBIDDEN;
import static io.netty.handler.codec.http.HttpVersion.HTTP_1_1;
public class WebSocketServerHandler extends SimpleChannelInboundHandler<Object> {
private static final String WEBSOCKET_PATH = "/stomp";
private HttpRequest httpRequest;
private WebSocketServerHandshaker handshaker;
private List<String> supportedProtocols;
private static final BinaryWebSocketEncoder BINARY_WEBSOCKET_ENCODER = new BinaryWebSocketEncoder();
public WebSocketServerHandler(List<String> supportedProtocols) {
this.supportedProtocols = supportedProtocols;
}
@Override
public void channelRead0(ChannelHandlerContext ctx, Object msg) throws Exception {
if (msg instanceof FullHttpRequest) {
handleHttpRequest(ctx, (FullHttpRequest) msg);
} else if (msg instanceof WebSocketFrame) {
WebSocketFrame frame = (WebSocketFrame) msg;
boolean handle = handleWebSocketFrame(ctx, frame);
if (handle) {
ctx.fireChannelRead(frame.content().retain());
}
}
}
private void handleHttpRequest(ChannelHandlerContext ctx, FullHttpRequest req) throws Exception {
// Allow only GET methods.
if (req.getMethod() != GET) {
sendHttpResponse(ctx, req, new DefaultFullHttpResponse(HTTP_1_1, FORBIDDEN));
return;
}
// Handshake
String supportedProtocolsCSV = StringUtil.joinStringList(supportedProtocols, ",");
WebSocketServerHandshakerFactory wsFactory = new WebSocketServerHandshakerFactory(this.getWebSocketLocation(req), supportedProtocolsCSV, false);
this.httpRequest = req;
this.handshaker = wsFactory.newHandshaker(req);
if (this.handshaker == null) {
WebSocketServerHandshakerFactory.sendUnsupportedVersionResponse(ctx.channel());
} else {
ChannelFuture handshake = this.handshaker.handshake(ctx.channel(), req);
handshake.addListener(new ChannelFutureListener() {
@Override
public void operationComplete(ChannelFuture future) throws Exception {
if (future.isSuccess()) {
// we need to insert an encoder that takes the underlying ChannelBuffer of a StompFrame.toActiveMQBuffer and
// wrap it in a binary web socket frame before letting the wsencoder send it on the wire
future.channel().pipeline().addAfter("wsencoder", "binary-websocket-encoder", BINARY_WEBSOCKET_ENCODER);
} else {
// Handshake failed, fire an exceptionCaught event
future.channel().pipeline().fireExceptionCaught(future.cause());
}
}
});
}
}
private boolean handleWebSocketFrame(ChannelHandlerContext ctx, WebSocketFrame frame) {
// Check for closing frame
if (frame instanceof CloseWebSocketFrame) {
this.handshaker.close(ctx.channel(), ((CloseWebSocketFrame) frame).retain());
return false;
} else if (frame instanceof PingWebSocketFrame) {
ctx.writeAndFlush(new PongWebSocketFrame(frame.content().retain()));
return false;
} else if (!(frame instanceof TextWebSocketFrame) && !(frame instanceof BinaryWebSocketFrame)) {
throw new UnsupportedOperationException(String.format("%s frame types not supported", frame.getClass().getName()));
}
return true;
}
private void sendHttpResponse(ChannelHandlerContext ctx, HttpRequest req, FullHttpResponse res) {
// Generate an error page if response status code is not OK (200).
if (res.getStatus().code() != 200) {
res.content().writeBytes(res.getStatus().toString().getBytes(StandardCharsets.UTF_8));
setContentLength(res, res.content().readableBytes());
}
// Send the response and close the connection if necessary.
ChannelFuture f = ctx.writeAndFlush(res);
if (!isKeepAlive(req) || res.getStatus().code() != 200) {
f.addListener(ChannelFutureListener.CLOSE);
}
}
@Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
cause.printStackTrace();
ctx.close();
}
private String getWebSocketLocation(HttpRequest req) {
return "ws://" + req.headers().get(HttpHeaders.Names.HOST) + WEBSOCKET_PATH;
}
public HttpRequest getHttpRequest() {
return this.httpRequest;
}
@Sharable
private static final class BinaryWebSocketEncoder extends ChannelOutboundHandlerAdapter {
@Override
public void write(ChannelHandlerContext ctx, Object msg, ChannelPromise promise) throws Exception {
if (msg instanceof ByteBuf) {
msg = new BinaryWebSocketFrame((ByteBuf) msg);
}
ctx.write(msg, promise);
}
}
}