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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 static org.jboss.netty.handler.codec.http.HttpHeaders.Values.*;
19  import static org.jboss.netty.handler.codec.http.HttpVersion.*;
20  
21  import java.io.UnsupportedEncodingException;
22  
23  import org.jboss.netty.channel.Channel;
24  import org.jboss.netty.channel.ChannelFuture;
25  import org.jboss.netty.channel.ChannelFutureListener;
26  import org.jboss.netty.channel.ChannelPipeline;
27  import org.jboss.netty.channel.Channels;
28  import org.jboss.netty.handler.codec.http.DefaultHttpResponse;
29  import org.jboss.netty.handler.codec.http.HttpChunkAggregator;
30  import org.jboss.netty.handler.codec.http.HttpHeaders.Names;
31  import org.jboss.netty.handler.codec.http.HttpRequest;
32  import org.jboss.netty.handler.codec.http.HttpRequestDecoder;
33  import org.jboss.netty.handler.codec.http.HttpResponse;
34  import org.jboss.netty.handler.codec.http.HttpResponseEncoder;
35  import org.jboss.netty.handler.codec.http.HttpResponseStatus;
36  import org.jboss.netty.logging.InternalLogger;
37  import org.jboss.netty.logging.InternalLoggerFactory;
38  import org.jboss.netty.util.CharsetUtil;
39  
40  /**
41   * <p>
42   * Performs server side opening and closing handshakes for web socket specification version <a
43   * href="http://tools.ietf.org/html/draft-ietf-hybi-thewebsocketprotocol-10" >draft-ietf-hybi-thewebsocketprotocol-
44   * 10</a>
45   * </p>
46   */
47  public class WebSocketServerHandshaker08 extends WebSocketServerHandshaker {
48  
49      private static final InternalLogger logger = InternalLoggerFactory.getInstance(WebSocketServerHandshaker08.class);
50  
51      public static final String WEBSOCKET_08_ACCEPT_GUID = "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";
52  
53      private final boolean allowExtensions;
54  
55      /**
56       * Constructor using defaults
57       *
58       * @param webSocketURL
59       *            URL for web socket communications. e.g "ws://myhost.com/mypath". Subsequent web socket frames will be
60       *            sent to this URL.
61       * @param subprotocols
62       *            CSV of supported protocols
63       * @param allowExtensions
64       *            Allow extensions to be used in the reserved bits of the web socket frame
65       */
66      public WebSocketServerHandshaker08(String webSocketURL, String subprotocols, boolean allowExtensions) {
67          this(webSocketURL, subprotocols, allowExtensions, Long.MAX_VALUE);
68      }
69  
70      /**
71       * Constructor
72       *
73       * @param webSocketURL
74       *            URL for web socket communications. e.g "ws://myhost.com/mypath". Subsequent web socket frames will be
75       *            sent to this URL.
76       * @param subprotocols
77       *            CSV of supported protocols
78       * @param allowExtensions
79       *            Allow extensions to be used in the reserved bits of the web socket frame
80       * @param maxFramePayloadLength
81       *            Maximum allowable frame payload length. Setting this value to your application's requirement may
82       *            reduce denial of service attacks using long data frames.
83       */
84      public WebSocketServerHandshaker08(String webSocketURL, String subprotocols, boolean allowExtensions,
85              long maxFramePayloadLength) {
86          super(WebSocketVersion.V08, webSocketURL, subprotocols, maxFramePayloadLength);
87          this.allowExtensions = allowExtensions;
88      }
89  
90      /**
91       * <p>
92       * Handle the web socket handshake for the web socket specification <a href=
93       * "http://tools.ietf.org/html/draft-ietf-hybi-thewebsocketprotocol-08">HyBi version 8 to 10</a>. Version 8, 9 and
94       * 10 share the same wire protocol.
95       * </p>
96       *
97       * <p>
98       * Browser request to the server:
99       * </p>
100      *
101      * <pre>
102      * GET /chat HTTP/1.1
103      * Host: server.example.com
104      * Upgrade: websocket
105      * Connection: Upgrade
106      * Sec-WebSocket-Key: dGhlIHNhbXBsZSBub25jZQ==
107      * Sec-WebSocket-Origin: http://example.com
108      * Sec-WebSocket-Protocol: chat, superchat
109      * Sec-WebSocket-Version: 8
110      * </pre>
111      *
112      * <p>
113      * Server response:
114      * </p>
115      *
116      * <pre>
117      * HTTP/1.1 101 Switching Protocols
118      * Upgrade: websocket
119      * Connection: Upgrade
120      * Sec-WebSocket-Accept: s3pPLMBiTxaQ9kYGzzhZRbK+xOo=
121      * Sec-WebSocket-Protocol: chat
122      * </pre>
123      *
124      * @param channel
125      *            Channel
126      * @param req
127      *            HTTP request
128      */
129     @Override
130     public ChannelFuture handshake(Channel channel, HttpRequest req) {
131 
132         if (logger.isDebugEnabled()) {
133             logger.debug(String.format("Channel %s WS Version 8 server handshake", channel.getId()));
134         }
135 
136         HttpResponse res = new DefaultHttpResponse(HTTP_1_1, HttpResponseStatus.SWITCHING_PROTOCOLS);
137 
138         String key = req.getHeader(Names.SEC_WEBSOCKET_KEY);
139         if (key == null) {
140             throw new WebSocketHandshakeException("not a WebSocket request: missing key");
141         }
142         String acceptSeed = key + WEBSOCKET_08_ACCEPT_GUID;
143         byte[] sha1;
144         try {
145             sha1 = WebSocketUtil.sha1(acceptSeed.getBytes(CharsetUtil.US_ASCII.name()));
146         } catch (UnsupportedEncodingException e) {
147             return Channels.failedFuture(channel, e);
148         }
149         String accept = WebSocketUtil.base64(sha1);
150 
151         if (logger.isDebugEnabled()) {
152             logger.debug(String.format("WS Version 8 Server Handshake key: %s. Response: %s.", key, accept));
153         }
154 
155         res.setStatus(HttpResponseStatus.SWITCHING_PROTOCOLS);
156         res.addHeader(Names.UPGRADE, WEBSOCKET.toLowerCase());
157         res.addHeader(Names.CONNECTION, Names.UPGRADE);
158         res.addHeader(Names.SEC_WEBSOCKET_ACCEPT, accept);
159         String subprotocols = req.getHeader(Names.SEC_WEBSOCKET_PROTOCOL);
160         if (subprotocols != null) {
161             String selectedSubprotocol = selectSubprotocol(subprotocols);
162             if (selectedSubprotocol == null) {
163                 throw new WebSocketHandshakeException("Requested subprotocol(s) not supported: " + subprotocols);
164             } else {
165                 res.addHeader(Names.SEC_WEBSOCKET_PROTOCOL, selectedSubprotocol);
166                 setSelectedSubprotocol(selectedSubprotocol);
167             }
168         }
169 
170         ChannelFuture future = channel.write(res);
171 
172         // Upgrade the connection and send the handshake response.
173         ChannelPipeline p = channel.getPipeline();
174         if (p.get(HttpChunkAggregator.class) != null) {
175             p.remove(HttpChunkAggregator.class);
176         }
177 
178         p.replace(HttpRequestDecoder.class, "wsdecoder",
179                 new WebSocket08FrameDecoder(true, allowExtensions, getMaxFramePayloadLength()));
180         p.replace(HttpResponseEncoder.class, "wsencoder", new WebSocket08FrameEncoder(false));
181 
182         return future;
183     }
184 
185     /**
186      * Echo back the closing frame and close the connection
187      *
188      * @param channel
189      *            Channel
190      * @param frame
191      *            Web Socket frame that was received
192      */
193     @Override
194     public ChannelFuture close(Channel channel, CloseWebSocketFrame frame) {
195         ChannelFuture f = channel.write(frame);
196         f.addListener(ChannelFutureListener.CLOSE);
197         return f;
198     }
199 
200 }