View Javadoc

1   //
2   //  ========================================================================
3   //  Copyright (c) 1995-2014 Mort Bay Consulting Pty. Ltd.
4   //  ------------------------------------------------------------------------
5   //  All rights reserved. This program and the accompanying materials
6   //  are made available under the terms of the Eclipse Public License v1.0
7   //  and Apache License v2.0 which accompanies this distribution.
8   //
9   //      The Eclipse Public License is available at
10  //      http://www.eclipse.org/legal/epl-v10.html
11  //
12  //      The Apache License v2.0 is available at
13  //      http://www.opensource.org/licenses/apache2.0.php
14  //
15  //  You may elect to redistribute this code under either of these licenses.
16  //  ========================================================================
17  //
18  
19  package org.eclipse.jetty.websocket;
20  
21  import java.io.IOException;
22  import java.util.Map;
23  import java.util.zip.DataFormatException;
24  import java.util.zip.Deflater;
25  import java.util.zip.Inflater;
26  
27  import org.eclipse.jetty.io.Buffer;
28  import org.eclipse.jetty.io.ByteArrayBuffer;
29  import org.eclipse.jetty.util.log.Log;
30  import org.eclipse.jetty.util.log.Logger;
31  
32  /**
33   * TODO Implement proposed deflate frame draft
34   */
35  public class DeflateFrameExtension extends AbstractExtension
36  {
37      private static final Logger LOG = Log.getLogger(DeflateFrameExtension.class);
38  
39      private int _minLength=8;
40      private Deflater _deflater;
41      private Inflater _inflater;
42  
43      public DeflateFrameExtension()
44      {
45          super("x-deflate-frame");
46      }
47  
48      @Override
49      public boolean init(Map<String, String> parameters)
50      {
51          if (!parameters.containsKey("minLength"))
52              parameters.put("minLength",Integer.toString(_minLength));
53          if(super.init(parameters))
54          {
55              _minLength=getInitParameter("minLength",_minLength);
56  
57              _deflater=new Deflater();
58              _inflater=new Inflater();
59  
60              return true;
61          }
62          return false;
63      }
64  
65      /* (non-Javadoc)
66       * @see org.eclipse.jetty.websocket.AbstractExtension#onFrame(byte, byte, org.eclipse.jetty.io.Buffer)
67       */
68      @Override
69      public void onFrame(byte flags, byte opcode, Buffer buffer)
70      {
71          if (getConnection().isControl(opcode) || !isFlag(flags,1))
72          {
73              super.onFrame(flags,opcode,buffer);
74              return;
75          }
76  
77          if (buffer.array()==null)
78              buffer=buffer.asMutableBuffer();
79  
80          int length=0xff&buffer.get();
81          if (length>=0x7e)
82          {
83              int b=(length==0x7f)?8:2;
84              length=0;
85              while(b-->0)
86                  length=0x100*length+(0xff&buffer.get());
87          }
88  
89          // TODO check a max framesize
90  
91          _inflater.setInput(buffer.array(),buffer.getIndex(),buffer.length());
92          ByteArrayBuffer buf = new ByteArrayBuffer(length);
93          try
94          {
95              while(_inflater.getRemaining()>0)
96              {
97                  int inflated=_inflater.inflate(buf.array(),buf.putIndex(),buf.space());
98                  if (inflated==0)
99                      throw new DataFormatException("insufficient data");
100                 buf.setPutIndex(buf.putIndex()+inflated);
101             }
102 
103             super.onFrame(clearFlag(flags,1),opcode,buf);
104         }
105         catch(DataFormatException e)
106         {
107             LOG.warn(e);
108             getConnection().close(WebSocketConnectionRFC6455.CLOSE_BAD_PAYLOAD,e.toString());
109         }
110     }
111 
112     /* (non-Javadoc)
113      * @see org.eclipse.jetty.websocket.AbstractExtension#addFrame(byte, byte, byte[], int, int)
114      */
115     @Override
116     public void addFrame(byte flags, byte opcode, byte[] content, int offset, int length) throws IOException
117     {
118         if (getConnection().isControl(opcode) || length<_minLength)
119         {
120             super.addFrame(clearFlag(flags,1),opcode,content,offset,length);
121             return;
122         }
123 
124         // prepare the uncompressed input
125         _deflater.reset();
126         _deflater.setInput(content,offset,length);
127         _deflater.finish();
128 
129         // prepare the output buffer
130         byte[] out= new byte[length];
131         int out_offset=0;
132 
133         // write the uncompressed length
134         if (length>0xffff)
135         {
136             out[out_offset++]=0x7f;
137             out[out_offset++]=(byte)0;
138             out[out_offset++]=(byte)0;
139             out[out_offset++]=(byte)0;
140             out[out_offset++]=(byte)0;
141             out[out_offset++]=(byte)((length>>24)&0xff);
142             out[out_offset++]=(byte)((length>>16)&0xff);
143             out[out_offset++]=(byte)((length>>8)&0xff);
144             out[out_offset++]=(byte)(length&0xff);
145         }
146         else if (length >=0x7e)
147         {
148             out[out_offset++]=0x7e;
149             out[out_offset++]=(byte)(length>>8);
150             out[out_offset++]=(byte)(length&0xff);
151         }
152         else
153         {
154             out[out_offset++]=(byte)(length&0x7f);
155         }
156 
157         int l = _deflater.deflate(out,out_offset,length-out_offset);
158 
159         if (_deflater.finished())
160             super.addFrame(setFlag(flags,1),opcode,out,0,l+out_offset);
161         else
162             super.addFrame(clearFlag(flags,1),opcode,content,offset,length);
163     }
164 }