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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.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.HttpSnoopServerHandler;
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  public class PortUnificationServerHandler extends FrameDecoder {
43  
44      private final boolean detectSsl;
45      private final boolean detectGzip;
46  
47      public PortUnificationServerHandler() {
48          this(true, true);
49      }
50  
51      private PortUnificationServerHandler(boolean detectSsl, boolean detectGzip) {
52          this.detectSsl = detectSsl;
53          this.detectGzip = detectGzip;
54      }
55  
56      @Override
57      protected Object decode(ChannelHandlerContext ctx, Channel channel, ChannelBuffer buffer) throws Exception {
58  
59          // Will use the first two bytes to detect a protocol.
60          if (buffer.readableBytes() < 2) {
61              return null;
62          }
63  
64          final int magic1 = buffer.getUnsignedByte(buffer.readerIndex());
65          final int magic2 = buffer.getUnsignedByte(buffer.readerIndex() + 1);
66  
67          if (isSsl(magic1)) {
68              enableSsl(ctx);
69          } else if (isGzip(magic1, magic2)) {
70              enableGzip(ctx);
71          } else if (isHttp(magic1, magic2)) {
72              switchToHttp(ctx);
73          } else if (isFactorial(magic1)) {
74              switchToFactorial(ctx);
75          } else {
76              // Unknown protocol; discard everything and close the connection.
77              buffer.skipBytes(buffer.readableBytes());
78              ctx.getChannel().close();
79              return null;
80          }
81  
82          // Forward the current read buffer as is to the new handlers.
83          return buffer.readBytes(buffer.readableBytes());
84      }
85  
86      private boolean isSsl(int magic1) {
87          if (detectSsl) {
88              switch (magic1) {
89              case 20: case 21: case 22: case 23: case 255:
90                  return true;
91              default:
92                  return magic1 >= 128;
93              }
94          }
95          return false;
96      }
97  
98      private boolean isGzip(int magic1, int magic2) {
99          if (detectGzip) {
100             return magic1 == 31 && magic2 == 139;
101         }
102         return false;
103     }
104 
105     private static boolean isHttp(int magic1, int magic2) {
106         return
107             magic1 == 'G' && magic2 == 'E' || // GET
108             magic1 == 'P' && magic2 == 'O' || // POST
109             magic1 == 'P' && magic2 == 'U' || // PUT
110             magic1 == 'H' && magic2 == 'E' || // HEAD
111             magic1 == 'O' && magic2 == 'P' || // OPTIONS
112             magic1 == 'P' && magic2 == 'A' || // PATCH
113             magic1 == 'D' && magic2 == 'E' || // DELETE
114             magic1 == 'T' && magic2 == 'R' || // TRACE
115             magic1 == 'C' && magic2 == 'O';   // CONNECT
116     }
117 
118     private static boolean isFactorial(int magic1) {
119         return magic1 == 'F';
120     }
121 
122     private void enableSsl(ChannelHandlerContext ctx) {
123         ChannelPipeline p = ctx.getPipeline();
124 
125         SSLEngine engine =
126             SecureChatSslContextFactory.getServerContext().createSSLEngine();
127         engine.setUseClientMode(false);
128 
129         p.addLast("ssl", new SslHandler(engine));
130         p.addLast("unificationA", new PortUnificationServerHandler(false, detectGzip));
131         p.remove(this);
132     }
133 
134     private void enableGzip(ChannelHandlerContext ctx) {
135         ChannelPipeline p = ctx.getPipeline();
136         p.addLast("gzipdeflater", new ZlibEncoder(ZlibWrapper.GZIP));
137         p.addLast("gzipinflater", new ZlibDecoder(ZlibWrapper.GZIP));
138         p.addLast("unificationB", new PortUnificationServerHandler(detectSsl, false));
139         p.remove(this);
140     }
141 
142     private void switchToHttp(ChannelHandlerContext ctx) {
143         ChannelPipeline p = ctx.getPipeline();
144         p.addLast("decoder", new HttpRequestDecoder());
145         p.addLast("encoder", new HttpResponseEncoder());
146         p.addLast("deflater", new HttpContentCompressor());
147         p.addLast("handler", new HttpSnoopServerHandler());
148         p.remove(this);
149     }
150 
151     private void switchToFactorial(ChannelHandlerContext ctx) {
152         ChannelPipeline p = ctx.getPipeline();
153         p.addLast("decoder", new BigIntegerDecoder());
154         p.addLast("encoder", new NumberEncoder());
155         p.addLast("handler", new FactorialServerHandler());
156         p.remove(this);
157     }
158 }