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1   /*
2    * Copyright 2013 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 io.netty.handler.codec.http.websocketx;
17  
18  
19  import io.netty.channel.ChannelFuture;
20  import io.netty.channel.ChannelFutureListener;
21  import io.netty.channel.ChannelHandlerContext;
22  import io.netty.channel.ChannelOutboundHandler;
23  import io.netty.channel.ChannelPromise;
24  import io.netty.channel.ChannelPromiseNotifier;
25  import io.netty.handler.codec.MessageToMessageDecoder;
26  import io.netty.util.ReferenceCountUtil;
27  import io.netty.util.concurrent.ScheduledFuture;
28  
29  import java.net.SocketAddress;
30  import java.nio.channels.ClosedChannelException;
31  import java.util.List;
32  import java.util.concurrent.TimeUnit;
33  
34  abstract class WebSocketProtocolHandler extends MessageToMessageDecoder<WebSocketFrame>
35          implements ChannelOutboundHandler {
36  
37      private final boolean dropPongFrames;
38      private final WebSocketCloseStatus closeStatus;
39      private final long forceCloseTimeoutMillis;
40      private ChannelPromise closeSent;
41  
42      /**
43       * Creates a new {@link WebSocketProtocolHandler} that will <i>drop</i> {@link PongWebSocketFrame}s.
44       */
45      WebSocketProtocolHandler() {
46          this(true);
47      }
48  
49      /**
50       * Creates a new {@link WebSocketProtocolHandler}, given a parameter that determines whether or not to drop {@link
51       * PongWebSocketFrame}s.
52       *
53       * @param dropPongFrames
54       *            {@code true} if {@link PongWebSocketFrame}s should be dropped
55       */
56      WebSocketProtocolHandler(boolean dropPongFrames) {
57          this(dropPongFrames, null, 0L);
58      }
59  
60      WebSocketProtocolHandler(boolean dropPongFrames,
61                               WebSocketCloseStatus closeStatus,
62                               long forceCloseTimeoutMillis) {
63          this.dropPongFrames = dropPongFrames;
64          this.closeStatus = closeStatus;
65          this.forceCloseTimeoutMillis = forceCloseTimeoutMillis;
66      }
67  
68      @Override
69      protected void decode(ChannelHandlerContext ctx, WebSocketFrame frame, List<Object> out) throws Exception {
70          if (frame instanceof PingWebSocketFrame) {
71              frame.content().retain();
72              ctx.channel().writeAndFlush(new PongWebSocketFrame(frame.content()));
73              readIfNeeded(ctx);
74              return;
75          }
76          if (frame instanceof PongWebSocketFrame && dropPongFrames) {
77              readIfNeeded(ctx);
78              return;
79          }
80  
81          out.add(frame.retain());
82      }
83  
84      private static void readIfNeeded(ChannelHandlerContext ctx) {
85          if (!ctx.channel().config().isAutoRead()) {
86              ctx.read();
87          }
88      }
89  
90      @Override
91      public void close(final ChannelHandlerContext ctx, final ChannelPromise promise) throws Exception {
92          if (closeStatus == null || !ctx.channel().isActive()) {
93              ctx.close(promise);
94          } else {
95              if (closeSent == null) {
96                  write(ctx, new CloseWebSocketFrame(closeStatus), ctx.newPromise());
97              }
98              flush(ctx);
99              applyCloseSentTimeout(ctx);
100             closeSent.addListener(new ChannelFutureListener() {
101                 @Override
102                 public void operationComplete(ChannelFuture future) {
103                     ctx.close(promise);
104                 }
105             });
106         }
107     }
108 
109     @Override
110     public void write(final ChannelHandlerContext ctx, Object msg, ChannelPromise promise) throws Exception {
111         if (closeSent != null) {
112             ReferenceCountUtil.release(msg);
113             promise.setFailure(new ClosedChannelException());
114         } else if (msg instanceof CloseWebSocketFrame) {
115             closeSent = promise.unvoid();
116             ctx.write(msg).addListener(new ChannelPromiseNotifier(false, closeSent));
117         } else {
118             ctx.write(msg, promise);
119         }
120     }
121 
122     private void applyCloseSentTimeout(ChannelHandlerContext ctx) {
123         if (closeSent.isDone() || forceCloseTimeoutMillis < 0) {
124             return;
125         }
126 
127         final ScheduledFuture<?> timeoutTask = ctx.executor().schedule(new Runnable() {
128             @Override
129             public void run() {
130                 if (!closeSent.isDone()) {
131                     closeSent.tryFailure(new WebSocketHandshakeException("send close frame timed out"));
132                 }
133             }
134         }, forceCloseTimeoutMillis, TimeUnit.MILLISECONDS);
135 
136         closeSent.addListener(new ChannelFutureListener() {
137             @Override
138             public void operationComplete(ChannelFuture future) {
139                 timeoutTask.cancel(false);
140             }
141         });
142     }
143 
144     @Override
145     public void bind(ChannelHandlerContext ctx, SocketAddress localAddress,
146                      ChannelPromise promise) throws Exception {
147         ctx.bind(localAddress, promise);
148     }
149 
150     @Override
151     public void connect(ChannelHandlerContext ctx, SocketAddress remoteAddress,
152                         SocketAddress localAddress, ChannelPromise promise) throws Exception {
153         ctx.connect(remoteAddress, localAddress, promise);
154     }
155 
156     @Override
157     public void disconnect(ChannelHandlerContext ctx, ChannelPromise promise)
158             throws Exception {
159         ctx.disconnect(promise);
160     }
161 
162     @Override
163     public void deregister(ChannelHandlerContext ctx, ChannelPromise promise) throws Exception {
164         ctx.deregister(promise);
165     }
166 
167     @Override
168     public void read(ChannelHandlerContext ctx) throws Exception {
169         ctx.read();
170     }
171 
172     @Override
173     public void flush(ChannelHandlerContext ctx) throws Exception {
174         ctx.flush();
175     }
176 
177     @Override
178     public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
179         ctx.fireExceptionCaught(cause);
180         ctx.close();
181     }
182 }