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1   /*
2    * Copyright 2010 Red Hat, Inc.
3    *
4    * Red Hat licenses this file to you under the Apache License, version 2.0
5    * (the "License"); you may not use this file except in compliance with the
6    * 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.example.portunification;
17  
18  import javax.net.ssl.SSLEngine;
19  
20  import org.jboss.netty.buffer.ChannelBuffer;
21  import org.jboss.netty.channel.Channel;
22  import org.jboss.netty.channel.ChannelHandlerContext;
23  import org.jboss.netty.channel.ChannelPipeline;
24  import org.jboss.netty.example.factorial.BigIntegerDecoder;
25  import org.jboss.netty.example.factorial.FactorialServerHandler;
26  import org.jboss.netty.example.factorial.NumberEncoder;
27  import org.jboss.netty.example.http.snoop.HttpRequestHandler;
28  import org.jboss.netty.example.securechat.SecureChatSslContextFactory;
29  import org.jboss.netty.handler.codec.compression.ZlibDecoder;
30  import org.jboss.netty.handler.codec.compression.ZlibEncoder;
31  import org.jboss.netty.handler.codec.compression.ZlibWrapper;
32  import org.jboss.netty.handler.codec.frame.FrameDecoder;
33  import org.jboss.netty.handler.codec.http.HttpContentCompressor;
34  import org.jboss.netty.handler.codec.http.HttpRequestDecoder;
35  import org.jboss.netty.handler.codec.http.HttpResponseEncoder;
36  import org.jboss.netty.handler.ssl.SslHandler;
37  
38  /**
39   * Manipulates the current pipeline dynamically to switch protocols or enable
40   * SSL or GZIP.
41   *
42   * @author <a href="http://www.jboss.org/netty/">The Netty Project</a>
43   * @author <a href="http://gleamynode.net/">Trustin Lee</a>
44   *
45   * @version $Rev: 2129 $, $Date: 2010-02-02 13:31:12 +0900 (Tue, 02 Feb 2010) $
46   */
47  public class PortUnificationServerHandler extends FrameDecoder {
48  
49      private final boolean detectSsl;
50      private final boolean detectGzip;
51  
52      public PortUnificationServerHandler() {
53          this(true, true);
54      }
55  
56      private PortUnificationServerHandler(boolean detectSsl, boolean detectGzip) {
57          this.detectSsl = detectSsl;
58          this.detectGzip = detectGzip;
59      }
60  
61      @Override
62      protected Object decode(ChannelHandlerContext ctx, Channel channel, ChannelBuffer buffer) throws Exception {
63  
64          // Will use the first two bytes to detect a protocol.
65          if (buffer.readableBytes() < 2) {
66              return null;
67          }
68  
69          final int magic1 = buffer.getUnsignedByte(buffer.readerIndex());
70          final int magic2 = buffer.getUnsignedByte(buffer.readerIndex() + 1);
71  
72          if (isSsl(magic1)) {
73              enableSsl(ctx);
74          } else if (isGzip(magic1, magic2)) {
75              enableGzip(ctx);
76          } else if (isHttp(magic1, magic2)) {
77              switchToHttp(ctx);
78          } else if (isFactorial(magic1)) {
79              switchToFactorial(ctx);
80          } else {
81              // Unknown protocol; discard everything and close the connection.
82              buffer.skipBytes(buffer.readableBytes());
83              ctx.getChannel().close();
84              return null;
85          }
86  
87          // Forward the current read buffer as is to the new handlers.
88          return buffer.readBytes(buffer.readableBytes());
89      }
90  
91      private boolean isSsl(int magic1) {
92          if (detectSsl) {
93              switch (magic1) {
94              case 20: case 21: case 22: case 23: case 255:
95                  return true;
96              default:
97                  return magic1 >= 128;
98              }
99          }
100         return false;
101     }
102 
103     private boolean isGzip(int magic1, int magic2) {
104         if (detectGzip) {
105             return magic1 == 31 && magic2 == 139;
106         }
107         return false;
108     }
109 
110     private boolean isHttp(int magic1, int magic2) {
111         return
112             magic1 == 'G' && magic2 == 'E' || // GET
113             magic1 == 'P' && magic2 == 'O' || // POST
114             magic1 == 'P' && magic2 == 'U' || // PUT
115             magic1 == 'H' && magic2 == 'E' || // HEAD
116             magic1 == 'O' && magic2 == 'P' || // OPTIONS
117             magic1 == 'P' && magic2 == 'A' || // PATCH
118             magic1 == 'D' && magic2 == 'E' || // DELETE
119             magic1 == 'T' && magic2 == 'R' || // TRACE
120             magic1 == 'C' && magic2 == 'O';   // CONNECT
121     }
122 
123     private boolean isFactorial(int magic1) {
124         return magic1 == 'F';
125     }
126 
127     private void enableSsl(ChannelHandlerContext ctx) {
128         ChannelPipeline p = ctx.getPipeline();
129 
130         SSLEngine engine =
131             SecureChatSslContextFactory.getServerContext().createSSLEngine();
132         engine.setUseClientMode(false);
133 
134         p.addLast("ssl", new SslHandler(engine));
135         p.addLast("unificationA", new PortUnificationServerHandler(false, detectGzip));
136         p.remove(this);
137     }
138 
139     private void enableGzip(ChannelHandlerContext ctx) {
140         ChannelPipeline p = ctx.getPipeline();
141         p.addLast("gzipdeflater", new ZlibEncoder(ZlibWrapper.GZIP));
142         p.addLast("gzipinflater", new ZlibDecoder(ZlibWrapper.GZIP));
143         p.addLast("unificationB", new PortUnificationServerHandler(detectSsl, false));
144         p.remove(this);
145     }
146 
147     private void switchToHttp(ChannelHandlerContext ctx) {
148         ChannelPipeline p = ctx.getPipeline();
149         p.addLast("decoder", new HttpRequestDecoder());
150         p.addLast("encoder", new HttpResponseEncoder());
151         p.addLast("deflater", new HttpContentCompressor());
152         p.addLast("handler", new HttpRequestHandler());
153         p.remove(this);
154     }
155 
156     private void switchToFactorial(ChannelHandlerContext ctx) {
157         ChannelPipeline p = ctx.getPipeline();
158         p.addLast("decoder", new BigIntegerDecoder());
159         p.addLast("encoder", new NumberEncoder());
160         p.addLast("handler", new FactorialServerHandler());
161         p.remove(this);
162     }
163 }