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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.HttpVersion.HTTP_1_1;
19  
20  import org.jboss.netty.buffer.ChannelBuffers;
21  import org.jboss.netty.channel.ChannelFutureListener;
22  import org.jboss.netty.channel.ChannelHandler;
23  import org.jboss.netty.channel.ChannelHandlerContext;
24  import org.jboss.netty.channel.ChannelPipeline;
25  import org.jboss.netty.channel.ExceptionEvent;
26  import org.jboss.netty.channel.LifeCycleAwareChannelHandler;
27  import org.jboss.netty.channel.MessageEvent;
28  import org.jboss.netty.channel.SimpleChannelHandler;
29  import org.jboss.netty.channel.SimpleChannelUpstreamHandler;
30  import org.jboss.netty.handler.codec.http.DefaultHttpResponse;
31  import org.jboss.netty.handler.codec.http.HttpResponseStatus;
32  
33  /**
34   * Handles WebSocket control frames (Close, Ping, Pong) and data frames (Text and Binary) are passed
35   * to the next handler in the pipeline.
36   */
37  public class WebSocketServerProtocolHandler extends SimpleChannelUpstreamHandler implements
38      LifeCycleAwareChannelHandler {
39  
40      private final String websocketPath;
41      private final String subprotocols;
42      private final boolean allowExtensions;
43  
44      public WebSocketServerProtocolHandler(String websocketPath) {
45          this(websocketPath, null, false);
46      }
47  
48      public WebSocketServerProtocolHandler(String websocketPath, String subprotocols) {
49          this(websocketPath, subprotocols, false);
50      }
51  
52      public WebSocketServerProtocolHandler(String websocketPath, String subprotocols, boolean allowExtensions) {
53          this.websocketPath = websocketPath;
54          this.subprotocols = subprotocols;
55          this.allowExtensions = allowExtensions;
56      }
57  
58      public void afterAdd(ChannelHandlerContext ctx) throws Exception {
59          ChannelPipeline cp = ctx.getPipeline();
60          if (cp.get(WebSocketServerProtocolHandshakeHandler.class) == null) {
61              // Add the WebSocketHandshakeHandler before this one.
62              ctx.getPipeline().addBefore(ctx.getName(), WebSocketServerProtocolHandshakeHandler.class.getName(),
63                      new WebSocketServerProtocolHandshakeHandler(websocketPath, subprotocols, allowExtensions));
64          }
65      }
66  
67      @Override
68      public void messageReceived(ChannelHandlerContext ctx, MessageEvent e) throws Exception {
69          if (e.getMessage() instanceof WebSocketFrame) {
70              WebSocketFrame frame = (WebSocketFrame) e.getMessage();
71              if (frame instanceof CloseWebSocketFrame) {
72                  WebSocketServerHandshaker handshaker = getHandshaker(ctx);
73                  handshaker.close(ctx.getChannel(), (CloseWebSocketFrame) frame);
74                  return;
75              } else if (frame instanceof PingWebSocketFrame) {
76                  ctx.getChannel().write(new PongWebSocketFrame(frame.getBinaryData()));
77                  return;
78              }
79          }
80          ctx.sendUpstream(e);
81      }
82  
83      @Override
84      public void exceptionCaught(ChannelHandlerContext ctx, ExceptionEvent e) throws Exception {
85          if (e.getCause() instanceof WebSocketHandshakeException) {
86              DefaultHttpResponse response = new DefaultHttpResponse(HTTP_1_1, HttpResponseStatus.BAD_REQUEST);
87              response.setContent(ChannelBuffers.wrappedBuffer(e.getCause().getMessage().getBytes()));
88              ctx.getChannel().write(response).addListener(ChannelFutureListener.CLOSE);
89          } else {
90              ctx.getChannel().close();
91          }
92      }
93  
94      static WebSocketServerHandshaker getHandshaker(ChannelHandlerContext ctx) {
95          return (WebSocketServerHandshaker) ctx.getAttachment();
96      }
97  
98      static void setHandshaker(ChannelHandlerContext ctx, WebSocketServerHandshaker handshaker) {
99          ctx.setAttachment(handshaker);
100     }
101 
102     static ChannelHandler forbiddenHttpRequestResponder() {
103         return new SimpleChannelHandler() {
104             @Override
105             public void messageReceived(ChannelHandlerContext ctx, MessageEvent e) throws Exception {
106                 if (!(e.getMessage() instanceof WebSocketFrame)) {
107                     DefaultHttpResponse response = new DefaultHttpResponse(HTTP_1_1, HttpResponseStatus.FORBIDDEN);
108                     ctx.getChannel().write(response);
109                 } else {
110                     ctx.sendUpstream(e);
111                 }
112             }
113         };
114     }
115 
116     public void beforeAdd(ChannelHandlerContext ctx) throws Exception {
117     }
118 
119     public void beforeRemove(ChannelHandlerContext ctx) throws Exception {
120     }
121 
122     public void afterRemove(ChannelHandlerContext ctx) throws Exception {
123     }
124 }