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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 org.jboss.netty.buffer.ChannelBuffer;
19  import org.jboss.netty.channel.Channel;
20  import org.jboss.netty.channel.ChannelHandlerContext;
21  import org.jboss.netty.channel.ChannelPipeline;
22  import org.jboss.netty.example.factorial.BigIntegerDecoder;
23  import org.jboss.netty.example.factorial.FactorialServerHandler;
24  import org.jboss.netty.example.factorial.NumberEncoder;
25  import org.jboss.netty.example.http.snoop.HttpSnoopServerHandler;
26  import org.jboss.netty.handler.codec.compression.ZlibDecoder;
27  import org.jboss.netty.handler.codec.compression.ZlibEncoder;
28  import org.jboss.netty.handler.codec.compression.ZlibWrapper;
29  import org.jboss.netty.handler.codec.frame.FrameDecoder;
30  import org.jboss.netty.handler.codec.http.HttpContentCompressor;
31  import org.jboss.netty.handler.codec.http.HttpRequestDecoder;
32  import org.jboss.netty.handler.codec.http.HttpResponseEncoder;
33  import org.jboss.netty.handler.ssl.SslContext;
34  import org.jboss.netty.handler.ssl.SslHandler;
35  
36  /**
37   * Manipulates the current pipeline dynamically to switch protocols or enable
38   * SSL or GZIP.
39   */
40  public class PortUnificationServerHandler extends FrameDecoder {
41  
42      private final SslContext sslCtx;
43      private final boolean detectSsl;
44      private final boolean detectGzip;
45  
46      public PortUnificationServerHandler(SslContext sslCtx) {
47          this(sslCtx, true, true);
48      }
49  
50      private PortUnificationServerHandler(SslContext sslCtx, boolean detectSsl, boolean detectGzip) {
51          this.sslCtx = sslCtx;
52          this.detectSsl = detectSsl;
53          this.detectGzip = detectGzip;
54      }
55  
56      @Override
57      protected Object decode(ChannelHandlerContext ctx, Channel channel, ChannelBuffer buffer) {
58          // Will use the first 5 bytes to detect a protocol.
59          if (buffer.readableBytes() < 5) {
60              return null;
61          }
62  
63          if (isSsl(buffer)) {
64              enableSsl(ctx);
65          } else {
66              final int magic1 = buffer.getUnsignedByte(buffer.readerIndex());
67              final int magic2 = buffer.getUnsignedByte(buffer.readerIndex() + 1);
68              if (isGzip(magic1, magic2)) {
69                  enableGzip(ctx);
70              } else if (isHttp(magic1, magic2)) {
71                  switchToHttp(ctx);
72              } else if (isFactorial(magic1)) {
73                  switchToFactorial(ctx);
74              } else {
75                  // Unknown protocol; discard everything and close the connection.
76                  buffer.skipBytes(buffer.readableBytes());
77                  ctx.getChannel().close();
78                  return null;
79              }
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(ChannelBuffer buffer) {
87          if (detectSsl) {
88              return SslHandler.isEncrypted(buffer);
89          }
90          return false;
91      }
92  
93      private boolean isGzip(int magic1, int magic2) {
94          if (detectGzip) {
95              return magic1 == 31 && magic2 == 139;
96          }
97          return false;
98      }
99  
100     private static boolean isHttp(int magic1, int magic2) {
101         return
102             magic1 == 'G' && magic2 == 'E' || // GET
103             magic1 == 'P' && magic2 == 'O' || // POST
104             magic1 == 'P' && magic2 == 'U' || // PUT
105             magic1 == 'H' && magic2 == 'E' || // HEAD
106             magic1 == 'O' && magic2 == 'P' || // OPTIONS
107             magic1 == 'P' && magic2 == 'A' || // PATCH
108             magic1 == 'D' && magic2 == 'E' || // DELETE
109             magic1 == 'T' && magic2 == 'R' || // TRACE
110             magic1 == 'C' && magic2 == 'O';   // CONNECT
111     }
112 
113     private static boolean isFactorial(int magic1) {
114         return magic1 == 'F';
115     }
116 
117     private void enableSsl(ChannelHandlerContext ctx) {
118         ChannelPipeline p = ctx.getPipeline();
119         p.addLast("ssl", sslCtx.newHandler());
120         p.addLast("unificationA", new PortUnificationServerHandler(sslCtx, false, detectGzip));
121         p.remove(this);
122     }
123 
124     private void enableGzip(ChannelHandlerContext ctx) {
125         ChannelPipeline p = ctx.getPipeline();
126         p.addLast("gzipdeflater", new ZlibEncoder(ZlibWrapper.GZIP));
127         p.addLast("gzipinflater", new ZlibDecoder(ZlibWrapper.GZIP));
128         p.addLast("unificationB", new PortUnificationServerHandler(sslCtx, detectSsl, false));
129         p.remove(this);
130     }
131 
132     private void switchToHttp(ChannelHandlerContext ctx) {
133         ChannelPipeline p = ctx.getPipeline();
134         p.addLast("decoder", new HttpRequestDecoder());
135         p.addLast("encoder", new HttpResponseEncoder());
136         p.addLast("deflater", new HttpContentCompressor());
137         p.addLast("handler", new HttpSnoopServerHandler());
138         p.remove(this);
139     }
140 
141     private void switchToFactorial(ChannelHandlerContext ctx) {
142         ChannelPipeline p = ctx.getPipeline();
143         p.addLast("decoder", new BigIntegerDecoder());
144         p.addLast("encoder", new NumberEncoder());
145         p.addLast("handler", new FactorialServerHandler());
146         p.remove(this);
147     }
148 }