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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 <a
38   * href="http://tools.ietf.org/html/rfc6455 ">RFC 6455</a> (originally web
39   * socket specification version <a
40   * href="http://tools.ietf.org/html/draft-ietf-hybi-thewebsocketprotocol-17"
41   * >draft-ietf-hybi-thewebsocketprotocol- 17</a>).
42   * </p>
43   */
44  public class WebSocketServerHandshaker13 extends WebSocketServerHandshaker {
45  
46      private static final InternalLogger logger = InternalLoggerFactory.getInstance(WebSocketServerHandshaker13.class);
47  
48      public static final String WEBSOCKET_13_ACCEPT_GUID = "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";
49  
50      private final boolean allowExtensions;
51  
52      /**
53       * Constructor using defaults
54       *
55       * @param webSocketURL
56       *            URL for web socket communications. e.g
57       *            "ws://myhost.com/mypath". Subsequent web socket frames will be
58       *            sent to this URL.
59       * @param subprotocols
60       *            CSV of supported protocols
61       * @param allowExtensions
62       *            Allow extensions to be used in the reserved bits of the web
63       *            socket frame
64       */
65      public WebSocketServerHandshaker13(String webSocketURL, String subprotocols, boolean allowExtensions) {
66          this(webSocketURL, subprotocols, allowExtensions, Long.MAX_VALUE);
67      }
68  
69      /**
70       * Constructor specifying the destination web socket location
71       *
72       * @param webSocketURL
73       *            URL for web socket communications. e.g
74       *            "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
80       *            socket frame
81       * @param maxFramePayloadLength
82       *            Maximum allowable frame payload length. Setting this value to
83       *            your application's requirement may reduce denial of service
84       *            attacks using long data frames.
85       */
86      public WebSocketServerHandshaker13(String webSocketURL, String subprotocols, boolean allowExtensions,
87              long maxFramePayloadLength) {
88          super(WebSocketVersion.V13, webSocketURL, subprotocols, maxFramePayloadLength);
89          this.allowExtensions = allowExtensions;
90      }
91  
92      /**
93       * <p>
94       * Handle the web socket handshake for the web socket specification <a href=
95       * "http://tools.ietf.org/html/draft-ietf-hybi-thewebsocketprotocol-17">HyBi
96       * versions 13-17</a>. Versions 13-17 share the same wire protocol.
97       * </p>
98       *
99       * <p>
100      * Browser request to the server:
101      * </p>
102      *
103      * <pre>
104      * GET /chat HTTP/1.1
105      * Host: server.example.com
106      * Upgrade: websocket
107      * Connection: Upgrade
108      * Sec-WebSocket-Key: dGhlIHNhbXBsZSBub25jZQ==
109      * Sec-WebSocket-Origin: http://example.com
110      * Sec-WebSocket-Protocol: chat, superchat
111      * Sec-WebSocket-Version: 13
112      * </pre>
113      *
114      * <p>
115      * Server response:
116      * </p>
117      *
118      * <pre>
119      * HTTP/1.1 101 Switching Protocols
120      * Upgrade: websocket
121      * Connection: Upgrade
122      * Sec-WebSocket-Accept: s3pPLMBiTxaQ9kYGzzhZRbK+xOo=
123      * Sec-WebSocket-Protocol: chat
124      * </pre>
125      *
126      * @param channel
127      *            Channel
128      * @param req
129      *            HTTP request
130      */
131     @Override
132     public ChannelFuture handshake(Channel channel, HttpRequest req) {
133 
134         if (logger.isDebugEnabled()) {
135             logger.debug(String.format("Channel %s WS Version 13 server handshake", channel.getId()));
136         }
137 
138         HttpResponse res = new DefaultHttpResponse(HTTP_1_1, HttpResponseStatus.SWITCHING_PROTOCOLS);
139 
140         String key = req.headers().get(Names.SEC_WEBSOCKET_KEY);
141         if (key == null) {
142             throw new WebSocketHandshakeException("not a WebSocket request: missing key");
143         }
144         String acceptSeed = key + WEBSOCKET_13_ACCEPT_GUID;
145         ChannelBuffer sha1 = WebSocketUtil.sha1(ChannelBuffers.copiedBuffer(acceptSeed, CharsetUtil.US_ASCII));
146         String accept = WebSocketUtil.base64(sha1);
147 
148         if (logger.isDebugEnabled()) {
149             logger.debug(String.format("WS Version 13 Server Handshake key: %s. Response: %s.", key, accept));
150         }
151 
152         res.setStatus(HttpResponseStatus.SWITCHING_PROTOCOLS);
153         res.headers().add(Names.UPGRADE, WEBSOCKET.toLowerCase());
154         res.headers().add(Names.CONNECTION, Names.UPGRADE);
155         res.headers().add(Names.SEC_WEBSOCKET_ACCEPT, accept);
156         String subprotocols = req.headers().get(Names.SEC_WEBSOCKET_PROTOCOL);
157         if (subprotocols != null) {
158             String selectedSubprotocol = selectSubprotocol(subprotocols);
159             if (selectedSubprotocol == null) {
160                 throw new WebSocketHandshakeException("Requested subprotocol(s) not supported: " + subprotocols);
161             } else {
162                 res.headers().add(Names.SEC_WEBSOCKET_PROTOCOL, selectedSubprotocol);
163                 setSelectedSubprotocol(selectedSubprotocol);
164             }
165         }
166 
167         return writeHandshakeResponse(
168                 channel, res, new WebSocket13FrameEncoder(false),
169                               new WebSocket13FrameDecoder(true, allowExtensions, getMaxFramePayloadLength()));
170     }
171 
172     /**
173      * Echo back the closing frame and close the connection
174      *
175      * @param channel
176      *            Channel
177      * @param frame
178      *            Web Socket frame that was received
179      */
180     @Override
181     public ChannelFuture close(Channel channel, CloseWebSocketFrame frame) {
182         ChannelFuture f = channel.write(frame);
183         f.addListener(ChannelFutureListener.CLOSE);
184         return f;
185     }
186 
187 }