/*
 * Copyright 2012 The Netty Project
 *
 * The Netty Project 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 io.netty.handler.codec.http.websocketx;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.Channel;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelPromise;
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.HttpHeaderNames;
import io.netty.handler.codec.http.HttpHeaderValues;
import io.netty.handler.codec.http.HttpHeaders;
import io.netty.handler.codec.http.HttpResponseStatus;

import java.util.regex.Pattern;

import static io.netty.handler.codec.http.HttpVersion.HTTP_1_1;

Performs server side opening and closing handshakes for web socket specification version draft-ietf-hybi-thewebsocketprotocol- 00

A very large portion of this code was taken from the Netty 3.2 HTTP example.

/** * <p> * Performs server side opening and closing handshakes for web socket specification version <a * href="http://tools.ietf.org/html/draft-ietf-hybi-thewebsocketprotocol-00" >draft-ietf-hybi-thewebsocketprotocol- * 00</a> * </p> * <p> * A very large portion of this code was taken from the Netty 3.2 HTTP example. * </p> */
public class WebSocketServerHandshaker00 extends WebSocketServerHandshaker { private static final Pattern BEGINNING_DIGIT = Pattern.compile("[^0-9]"); private static final Pattern BEGINNING_SPACE = Pattern.compile("[^ ]");
Constructor specifying the destination web socket location
Params:
  • webSocketURL – URL for web socket communications. e.g "ws://myhost.com/mypath". Subsequent web socket frames will be sent to this URL.
  • subprotocols – CSV of supported protocols
  • maxFramePayloadLength – Maximum allowable frame payload length. Setting this value to your application's requirement may reduce denial of service attacks using long data frames.
/** * Constructor specifying the destination web socket location * * @param webSocketURL * URL for web socket communications. e.g "ws://myhost.com/mypath". Subsequent web socket frames will be * sent to this URL. * @param subprotocols * CSV of supported protocols * @param maxFramePayloadLength * Maximum allowable frame payload length. Setting this value to your application's requirement may * reduce denial of service attacks using long data frames. */
public WebSocketServerHandshaker00(String webSocketURL, String subprotocols, int maxFramePayloadLength) { super(WebSocketVersion.V00, webSocketURL, subprotocols, maxFramePayloadLength); }

Handle the web socket handshake for the web socket specification HyBi version 0 and lower. This standard is really a rehash of hixie-76 and hixie-75.

Browser request to the server:

GET /demo HTTP/1.1
Upgrade: WebSocket
Connection: Upgrade
Host: example.com
Origin: http://example.com
Sec-WebSocket-Protocol: chat, sample
Sec-WebSocket-Key1: 4 @1  46546xW%0l 1 5
Sec-WebSocket-Key2: 12998 5 Y3 1  .P00
^n:ds[4U

Server response:

HTTP/1.1 101 WebSocket Protocol Handshake
Upgrade: WebSocket
Connection: Upgrade
Sec-WebSocket-Origin: http://example.com
Sec-WebSocket-Location: ws://example.com/demo
Sec-WebSocket-Protocol: sample
8jKS'y:G*Co,Wxa-
/** * <p> * Handle the web socket handshake for the web socket specification <a href= * "http://tools.ietf.org/html/draft-ietf-hybi-thewebsocketprotocol-00">HyBi version 0</a> and lower. This standard * is really a rehash of <a href="http://tools.ietf.org/html/draft-hixie-thewebsocketprotocol-76" >hixie-76</a> and * <a href="http://tools.ietf.org/html/draft-hixie-thewebsocketprotocol-75" >hixie-75</a>. * </p> * * <p> * Browser request to the server: * </p> * * <pre> * GET /demo HTTP/1.1 * Upgrade: WebSocket * Connection: Upgrade * Host: example.com * Origin: http://example.com * Sec-WebSocket-Protocol: chat, sample * Sec-WebSocket-Key1: 4 @1 46546xW%0l 1 5 * Sec-WebSocket-Key2: 12998 5 Y3 1 .P00 * * ^n:ds[4U * </pre> * * <p> * Server response: * </p> * * <pre> * HTTP/1.1 101 WebSocket Protocol Handshake * Upgrade: WebSocket * Connection: Upgrade * Sec-WebSocket-Origin: http://example.com * Sec-WebSocket-Location: ws://example.com/demo * Sec-WebSocket-Protocol: sample * * 8jKS'y:G*Co,Wxa- * </pre> */
@Override protected FullHttpResponse newHandshakeResponse(FullHttpRequest req, HttpHeaders headers) { // Serve the WebSocket handshake request. if (!req.headers().containsValue(HttpHeaderNames.CONNECTION, HttpHeaderValues.UPGRADE, true) || !HttpHeaderValues.WEBSOCKET.contentEqualsIgnoreCase(req.headers().get(HttpHeaderNames.UPGRADE))) { throw new WebSocketHandshakeException("not a WebSocket handshake request: missing upgrade"); } // Hixie 75 does not contain these headers while Hixie 76 does boolean isHixie76 = req.headers().contains(HttpHeaderNames.SEC_WEBSOCKET_KEY1) && req.headers().contains(HttpHeaderNames.SEC_WEBSOCKET_KEY2); // Create the WebSocket handshake response. FullHttpResponse res = new DefaultFullHttpResponse(HTTP_1_1, new HttpResponseStatus(101, isHixie76 ? "WebSocket Protocol Handshake" : "Web Socket Protocol Handshake")); if (headers != null) { res.headers().add(headers); } res.headers().add(HttpHeaderNames.UPGRADE, HttpHeaderValues.WEBSOCKET); res.headers().add(HttpHeaderNames.CONNECTION, HttpHeaderValues.UPGRADE); // Fill in the headers and contents depending on handshake getMethod. if (isHixie76) { // New handshake getMethod with a challenge: res.headers().add(HttpHeaderNames.SEC_WEBSOCKET_ORIGIN, req.headers().get(HttpHeaderNames.ORIGIN)); res.headers().add(HttpHeaderNames.SEC_WEBSOCKET_LOCATION, uri()); String subprotocols = req.headers().get(HttpHeaderNames.SEC_WEBSOCKET_PROTOCOL); if (subprotocols != null) { String selectedSubprotocol = selectSubprotocol(subprotocols); if (selectedSubprotocol == null) { if (logger.isDebugEnabled()) { logger.debug("Requested subprotocol(s) not supported: {}", subprotocols); } } else { res.headers().add(HttpHeaderNames.SEC_WEBSOCKET_PROTOCOL, selectedSubprotocol); } } // Calculate the answer of the challenge. String key1 = req.headers().get(HttpHeaderNames.SEC_WEBSOCKET_KEY1); String key2 = req.headers().get(HttpHeaderNames.SEC_WEBSOCKET_KEY2); int a = (int) (Long.parseLong(BEGINNING_DIGIT.matcher(key1).replaceAll("")) / BEGINNING_SPACE.matcher(key1).replaceAll("").length()); int b = (int) (Long.parseLong(BEGINNING_DIGIT.matcher(key2).replaceAll("")) / BEGINNING_SPACE.matcher(key2).replaceAll("").length()); long c = req.content().readLong(); ByteBuf input = Unpooled.buffer(16); input.writeInt(a); input.writeInt(b); input.writeLong(c); res.content().writeBytes(WebSocketUtil.md5(input.array())); } else { // Old Hixie 75 handshake getMethod with no challenge: res.headers().add(HttpHeaderNames.WEBSOCKET_ORIGIN, req.headers().get(HttpHeaderNames.ORIGIN)); res.headers().add(HttpHeaderNames.WEBSOCKET_LOCATION, uri()); String protocol = req.headers().get(HttpHeaderNames.WEBSOCKET_PROTOCOL); if (protocol != null) { res.headers().add(HttpHeaderNames.WEBSOCKET_PROTOCOL, selectSubprotocol(protocol)); } } return res; }
Echo back the closing frame
Params:
  • channel – Channel
  • frame – Web Socket frame that was received
/** * Echo back the closing frame * * @param channel * Channel * @param frame * Web Socket frame that was received */
@Override public ChannelFuture close(Channel channel, CloseWebSocketFrame frame, ChannelPromise promise) { return channel.writeAndFlush(frame, promise); } @Override protected WebSocketFrameDecoder newWebsocketDecoder() { return new WebSocket00FrameDecoder(maxFramePayloadLength()); } @Override protected WebSocketFrameEncoder newWebSocketEncoder() { return new WebSocket00FrameEncoder(); } }