Wordpress 3.5
[autoinstalls/wordpress.git] / wp-includes / SimplePie / Content / Type / Sniffer.php
1 <?php
2 /**
3  * SimplePie
4  *
5  * A PHP-Based RSS and Atom Feed Framework.
6  * Takes the hard work out of managing a complete RSS/Atom solution.
7  *
8  * Copyright (c) 2004-2012, Ryan Parman, Geoffrey Sneddon, Ryan McCue, and contributors
9  * All rights reserved.
10  *
11  * Redistribution and use in source and binary forms, with or without modification, are
12  * permitted provided that the following conditions are met:
13  *
14  *      * Redistributions of source code must retain the above copyright notice, this list of
15  *        conditions and the following disclaimer.
16  *
17  *      * Redistributions in binary form must reproduce the above copyright notice, this list
18  *        of conditions and the following disclaimer in the documentation and/or other materials
19  *        provided with the distribution.
20  *
21  *      * Neither the name of the SimplePie Team nor the names of its contributors may be used
22  *        to endorse or promote products derived from this software without specific prior
23  *        written permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS
26  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
27  * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS
28  * AND CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
29  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
30  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
31  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
32  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
33  * POSSIBILITY OF SUCH DAMAGE.
34  *
35  * @package SimplePie
36  * @version 1.3.1
37  * @copyright 2004-2012 Ryan Parman, Geoffrey Sneddon, Ryan McCue
38  * @author Ryan Parman
39  * @author Geoffrey Sneddon
40  * @author Ryan McCue
41  * @link http://simplepie.org/ SimplePie
42  * @license http://www.opensource.org/licenses/bsd-license.php BSD License
43  */
44
45
46 /**
47  * Content-type sniffing
48  *
49  * Based on the rules in http://tools.ietf.org/html/draft-abarth-mime-sniff-06
50  *
51  * This is used since we can't always trust Content-Type headers, and is based
52  * upon the HTML5 parsing rules.
53  *
54  *
55  * This class can be overloaded with {@see SimplePie::set_content_type_sniffer_class()}
56  *
57  * @package SimplePie
58  * @subpackage HTTP
59  */
60 class SimplePie_Content_Type_Sniffer
61 {
62         /**
63          * File object
64          *
65          * @var SimplePie_File
66          */
67         var $file;
68
69         /**
70          * Create an instance of the class with the input file
71          *
72          * @param SimplePie_Content_Type_Sniffer $file Input file
73          */
74         public function __construct($file)
75         {
76                 $this->file = $file;
77         }
78
79         /**
80          * Get the Content-Type of the specified file
81          *
82          * @return string Actual Content-Type
83          */
84         public function get_type()
85         {
86                 if (isset($this->file->headers['content-type']))
87                 {
88                         if (!isset($this->file->headers['content-encoding'])
89                                 && ($this->file->headers['content-type'] === 'text/plain'
90                                         || $this->file->headers['content-type'] === 'text/plain; charset=ISO-8859-1'
91                                         || $this->file->headers['content-type'] === 'text/plain; charset=iso-8859-1'
92                                         || $this->file->headers['content-type'] === 'text/plain; charset=UTF-8'))
93                         {
94                                 return $this->text_or_binary();
95                         }
96
97                         if (($pos = strpos($this->file->headers['content-type'], ';')) !== false)
98                         {
99                                 $official = substr($this->file->headers['content-type'], 0, $pos);
100                         }
101                         else
102                         {
103                                 $official = $this->file->headers['content-type'];
104                         }
105                         $official = trim(strtolower($official));
106
107                         if ($official === 'unknown/unknown'
108                                 || $official === 'application/unknown')
109                         {
110                                 return $this->unknown();
111                         }
112                         elseif (substr($official, -4) === '+xml'
113                                 || $official === 'text/xml'
114                                 || $official === 'application/xml')
115                         {
116                                 return $official;
117                         }
118                         elseif (substr($official, 0, 6) === 'image/')
119                         {
120                                 if ($return = $this->image())
121                                 {
122                                         return $return;
123                                 }
124                                 else
125                                 {
126                                         return $official;
127                                 }
128                         }
129                         elseif ($official === 'text/html')
130                         {
131                                 return $this->feed_or_html();
132                         }
133                         else
134                         {
135                                 return $official;
136                         }
137                 }
138                 else
139                 {
140                         return $this->unknown();
141                 }
142         }
143
144         /**
145          * Sniff text or binary
146          *
147          * @return string Actual Content-Type
148          */
149         public function text_or_binary()
150         {
151                 if (substr($this->file->body, 0, 2) === "\xFE\xFF"
152                         || substr($this->file->body, 0, 2) === "\xFF\xFE"
153                         || substr($this->file->body, 0, 4) === "\x00\x00\xFE\xFF"
154                         || substr($this->file->body, 0, 3) === "\xEF\xBB\xBF")
155                 {
156                         return 'text/plain';
157                 }
158                 elseif (preg_match('/[\x00-\x08\x0E-\x1A\x1C-\x1F]/', $this->file->body))
159                 {
160                         return 'application/octect-stream';
161                 }
162                 else
163                 {
164                         return 'text/plain';
165                 }
166         }
167
168         /**
169          * Sniff unknown
170          *
171          * @return string Actual Content-Type
172          */
173         public function unknown()
174         {
175                 $ws = strspn($this->file->body, "\x09\x0A\x0B\x0C\x0D\x20");
176                 if (strtolower(substr($this->file->body, $ws, 14)) === '<!doctype html'
177                         || strtolower(substr($this->file->body, $ws, 5)) === '<html'
178                         || strtolower(substr($this->file->body, $ws, 7)) === '<script')
179                 {
180                         return 'text/html';
181                 }
182                 elseif (substr($this->file->body, 0, 5) === '%PDF-')
183                 {
184                         return 'application/pdf';
185                 }
186                 elseif (substr($this->file->body, 0, 11) === '%!PS-Adobe-')
187                 {
188                         return 'application/postscript';
189                 }
190                 elseif (substr($this->file->body, 0, 6) === 'GIF87a'
191                         || substr($this->file->body, 0, 6) === 'GIF89a')
192                 {
193                         return 'image/gif';
194                 }
195                 elseif (substr($this->file->body, 0, 8) === "\x89\x50\x4E\x47\x0D\x0A\x1A\x0A")
196                 {
197                         return 'image/png';
198                 }
199                 elseif (substr($this->file->body, 0, 3) === "\xFF\xD8\xFF")
200                 {
201                         return 'image/jpeg';
202                 }
203                 elseif (substr($this->file->body, 0, 2) === "\x42\x4D")
204                 {
205                         return 'image/bmp';
206                 }
207                 elseif (substr($this->file->body, 0, 4) === "\x00\x00\x01\x00")
208                 {
209                         return 'image/vnd.microsoft.icon';
210                 }
211                 else
212                 {
213                         return $this->text_or_binary();
214                 }
215         }
216
217         /**
218          * Sniff images
219          *
220          * @return string Actual Content-Type
221          */
222         public function image()
223         {
224                 if (substr($this->file->body, 0, 6) === 'GIF87a'
225                         || substr($this->file->body, 0, 6) === 'GIF89a')
226                 {
227                         return 'image/gif';
228                 }
229                 elseif (substr($this->file->body, 0, 8) === "\x89\x50\x4E\x47\x0D\x0A\x1A\x0A")
230                 {
231                         return 'image/png';
232                 }
233                 elseif (substr($this->file->body, 0, 3) === "\xFF\xD8\xFF")
234                 {
235                         return 'image/jpeg';
236                 }
237                 elseif (substr($this->file->body, 0, 2) === "\x42\x4D")
238                 {
239                         return 'image/bmp';
240                 }
241                 elseif (substr($this->file->body, 0, 4) === "\x00\x00\x01\x00")
242                 {
243                         return 'image/vnd.microsoft.icon';
244                 }
245                 else
246                 {
247                         return false;
248                 }
249         }
250
251         /**
252          * Sniff HTML
253          *
254          * @return string Actual Content-Type
255          */
256         public function feed_or_html()
257         {
258                 $len = strlen($this->file->body);
259                 $pos = strspn($this->file->body, "\x09\x0A\x0D\x20");
260
261                 while ($pos < $len)
262                 {
263                         switch ($this->file->body[$pos])
264                         {
265                                 case "\x09":
266                                 case "\x0A":
267                                 case "\x0D":
268                                 case "\x20":
269                                         $pos += strspn($this->file->body, "\x09\x0A\x0D\x20", $pos);
270                                         continue 2;
271
272                                 case '<':
273                                         $pos++;
274                                         break;
275
276                                 default:
277                                         return 'text/html';
278                         }
279
280                         if (substr($this->file->body, $pos, 3) === '!--')
281                         {
282                                 $pos += 3;
283                                 if ($pos < $len && ($pos = strpos($this->file->body, '-->', $pos)) !== false)
284                                 {
285                                         $pos += 3;
286                                 }
287                                 else
288                                 {
289                                         return 'text/html';
290                                 }
291                         }
292                         elseif (substr($this->file->body, $pos, 1) === '!')
293                         {
294                                 if ($pos < $len && ($pos = strpos($this->file->body, '>', $pos)) !== false)
295                                 {
296                                         $pos++;
297                                 }
298                                 else
299                                 {
300                                         return 'text/html';
301                                 }
302                         }
303                         elseif (substr($this->file->body, $pos, 1) === '?')
304                         {
305                                 if ($pos < $len && ($pos = strpos($this->file->body, '?>', $pos)) !== false)
306                                 {
307                                         $pos += 2;
308                                 }
309                                 else
310                                 {
311                                         return 'text/html';
312                                 }
313                         }
314                         elseif (substr($this->file->body, $pos, 3) === 'rss'
315                                 || substr($this->file->body, $pos, 7) === 'rdf:RDF')
316                         {
317                                 return 'application/rss+xml';
318                         }
319                         elseif (substr($this->file->body, $pos, 4) === 'feed')
320                         {
321                                 return 'application/atom+xml';
322                         }
323                         else
324                         {
325                                 return 'text/html';
326                         }
327                 }
328
329                 return 'text/html';
330         }
331 }
332