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1   /*
2    * Copyright 2012 The Netty Project
3    *
4    * The Netty Project licenses this file to you under the Apache License,
5    * version 2.0 (the "License"); you may not use this file except in compliance
6    * with the License. You may obtain a copy of the License at:
7    *
8    *   http://www.apache.org/licenses/LICENSE-2.0
9    *
10   * Unless required by applicable law or agreed to in writing, software
11   * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
12   * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
13   * License for the specific language governing permissions and limitations
14   * under the License.
15   */
16  package org.jboss.netty.handler.codec.http.websocketx;
17  
18  import org.jboss.netty.buffer.ChannelBuffer;
19  import org.jboss.netty.buffer.ChannelBuffers;
20  import org.jboss.netty.channel.Channel;
21  import org.jboss.netty.channel.ChannelFuture;
22  import org.jboss.netty.channel.ChannelFutureListener;
23  import org.jboss.netty.handler.codec.http.DefaultHttpResponse;
24  import org.jboss.netty.handler.codec.http.HttpHeaders.Names;
25  import org.jboss.netty.handler.codec.http.HttpRequest;
26  import org.jboss.netty.handler.codec.http.HttpResponse;
27  import org.jboss.netty.handler.codec.http.HttpResponseStatus;
28  import org.jboss.netty.logging.InternalLogger;
29  import org.jboss.netty.logging.InternalLoggerFactory;
30  import org.jboss.netty.util.CharsetUtil;
31  
32  import static org.jboss.netty.handler.codec.http.HttpHeaders.Values.*;
33  import static org.jboss.netty.handler.codec.http.HttpVersion.*;
34  
35  /**
36   * <p>
37   * Performs server side opening and closing handshakes for web socket specification version <a
38   * href="http://tools.ietf.org/html/draft-ietf-hybi-thewebsocketprotocol-07" >draft-ietf-hybi-thewebsocketprotocol-
39   * 07</a>
40   * </p>
41   */
42  public class WebSocketServerHandshaker07 extends WebSocketServerHandshaker {
43  
44      private static final InternalLogger logger = InternalLoggerFactory.getInstance(WebSocketServerHandshaker07.class);
45  
46      public static final String WEBSOCKET_07_ACCEPT_GUID = "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";
47  
48      private final boolean allowExtensions;
49  
50      /**
51       * Constructor specifying the destination web socket location
52       *
53       * @param webSocketURL
54       *            URL for web socket communications. e.g "ws://myhost.com/mypath".
55       *            Subsequent web socket frames will be sent to this URL.
56       * @param subprotocols
57       *            CSV of supported protocols
58       * @param allowExtensions
59       *            Allow extensions to be used in the reserved bits of the web socket frame
60       * @param maxFramePayloadLength
61       *            Maximum allowable frame payload length. Setting this value to your application's
62       *            requirement may reduce denial of service attacks using long data frames.
63       */
64      public WebSocketServerHandshaker07(
65              String webSocketURL, String subprotocols, boolean allowExtensions, long maxFramePayloadLength) {
66          super(WebSocketVersion.V07, webSocketURL, subprotocols, maxFramePayloadLength);
67          this.allowExtensions = allowExtensions;
68      }
69  
70      /**
71       * <p>
72       * Handle the web socket handshake for the web socket specification <a href=
73       * "http://tools.ietf.org/html/draft-ietf-hybi-thewebsocketprotocol-07">HyBi version 7</a>.
74       * </p>
75       *
76       * <p>
77       * Browser request to the server:
78       * </p>
79       *
80       * <pre>
81       * GET /chat HTTP/1.1
82       * Host: server.example.com
83       * Upgrade: websocket
84       * Connection: Upgrade
85       * Sec-WebSocket-Key: dGhlIHNhbXBsZSBub25jZQ==
86       * Sec-WebSocket-Origin: http://example.com
87       * Sec-WebSocket-Protocol: chat, superchat
88       * Sec-WebSocket-Version: 7
89       * </pre>
90       *
91       * <p>
92       * Server response:
93       * </p>
94       *
95       * <pre>
96       * HTTP/1.1 101 Switching Protocols
97       * Upgrade: websocket
98       * Connection: Upgrade
99       * Sec-WebSocket-Accept: s3pPLMBiTxaQ9kYGzzhZRbK+xOo=
100      * Sec-WebSocket-Protocol: chat
101      * </pre>
102      *
103      * @param channel
104      *            Channel
105      * @param req
106      *            HTTP request
107      */
108     @Override
109     public ChannelFuture handshake(Channel channel, HttpRequest req) {
110 
111         if (logger.isDebugEnabled()) {
112             logger.debug(String.format("Channel %s WS Version 7 server handshake", channel.getId()));
113         }
114         HttpResponse res = new DefaultHttpResponse(HTTP_1_1, HttpResponseStatus.SWITCHING_PROTOCOLS);
115 
116         String key = req.headers().get(Names.SEC_WEBSOCKET_KEY);
117         if (key == null) {
118             throw new WebSocketHandshakeException("not a WebSocket request: missing key");
119         }
120         String acceptSeed = key + WEBSOCKET_07_ACCEPT_GUID;
121         ChannelBuffer sha1 = WebSocketUtil.sha1(ChannelBuffers.copiedBuffer(acceptSeed, CharsetUtil.US_ASCII));
122         String accept = WebSocketUtil.base64(sha1);
123 
124         if (logger.isDebugEnabled()) {
125             logger.debug(String.format("WS Version 7 Server Handshake key: %s. Response: %s.", key, accept));
126         }
127 
128         res.setStatus(HttpResponseStatus.SWITCHING_PROTOCOLS);
129         res.headers().add(Names.UPGRADE, WEBSOCKET.toLowerCase());
130         res.headers().add(Names.CONNECTION, Names.UPGRADE);
131         res.headers().add(Names.SEC_WEBSOCKET_ACCEPT, accept);
132         String subprotocols = req.headers().get(Names.SEC_WEBSOCKET_PROTOCOL);
133         if (subprotocols != null) {
134             String selectedSubprotocol = selectSubprotocol(subprotocols);
135             if (selectedSubprotocol == null) {
136                 throw new WebSocketHandshakeException("Requested subprotocol(s) not supported: " + subprotocols);
137             } else {
138                 res.headers().add(Names.SEC_WEBSOCKET_PROTOCOL, selectedSubprotocol);
139                 setSelectedSubprotocol(selectedSubprotocol);
140             }
141         }
142 
143         return writeHandshakeResponse(
144                 channel, res, new WebSocket07FrameEncoder(false),
145                               new WebSocket07FrameDecoder(true, allowExtensions, getMaxFramePayloadLength()));
146     }
147 
148     /**
149      * Echo back the closing frame and close the connection
150      *
151      * @param channel
152      *            Channel
153      * @param frame
154      *            Web Socket frame that was received
155      */
156     @Override
157     public ChannelFuture close(Channel channel, CloseWebSocketFrame frame) {
158         ChannelFuture future = channel.write(frame);
159         future.addListener(ChannelFutureListener.CLOSE);
160         return future;
161     }
162 }