xref: /dokuwiki/lib/exe/fetch.php (revision 73f799f0aa6144ef07d0af5a050b845a88ba991d)
1<?php
2/**
3 * DokuWiki media passthrough file
4 *
5 * @license    GPL 2 (http://www.gnu.org/licenses/gpl.html)
6 * @author     Andreas Gohr <andi@splitbrain.org>
7 */
8
9  if(!defined('DOKU_INC')) define('DOKU_INC',dirname(__FILE__).'/../../');
10  define('DOKU_DISABLE_GZIP_OUTPUT', 1);
11  require_once(DOKU_INC.'inc/init.php');
12
13  //close session
14  session_write_close();
15
16  $mimetypes = getMimeTypes();
17
18  //get input
19  $MEDIA  = stripctl(getID('media',false)); // no cleaning except control chars - maybe external
20  $CACHE  = calc_cache($_REQUEST['cache']);
21  $WIDTH  = (int) $_REQUEST['w'];
22  $HEIGHT = (int) $_REQUEST['h'];
23  list($EXT,$MIME,$DL) = mimetype($MEDIA,false);
24  if($EXT === false){
25    $EXT  = 'unknown';
26    $MIME = 'application/octet-stream';
27    $DL   = true;
28  }
29
30  // check for permissions, preconditions and cache external files
31  list($STATUS, $STATUSMESSAGE) = checkFileStatus($MEDIA, $FILE);
32
33  // prepare data for plugin events
34  $data = array('media'           => $MEDIA,
35                'file'            => $FILE,
36                'orig'            => $FILE,
37                'mime'            => $MIME,
38                'download'        => $DL,
39                'cache'           => $CACHE,
40                'ext'             => $EXT,
41                'width'           => $WIDTH,
42                'height'          => $HEIGHT,
43                'status'          => $STATUS,
44                'statusmessage'   => $STATUSMESSAGE,
45  );
46
47  // handle the file status
48  $evt = new Doku_Event('FETCH_MEDIA_STATUS', $data);
49  if ( $evt->advise_before() ) {
50    // redirects
51    if($data['status'] > 300 && $data['status'] <= 304){
52      send_redirect($data['statusmessage']);
53    }
54    // send any non 200 status
55    if($data['status'] != 200){
56      header('HTTP/1.0 ' . $data['status'] . ' ' . $data['statusmessage']);
57    }
58    // die on errors
59    if($data['status'] > 203){
60      print $data['statusmessage'];
61      exit;
62    }
63  }
64  $evt->advise_after();
65  unset($evt);
66
67  //handle image resizing/cropping
68  if((substr($MIME,0,5) == 'image') && $WIDTH){
69    if($HEIGHT){
70        $data['file'] = $FILE = media_crop_image($data['file'],$EXT,$WIDTH,$HEIGHT);
71    }else{
72        $data['file'] = $FILE  = media_resize_image($data['file'],$EXT,$WIDTH,$HEIGHT);
73    }
74  }
75
76  // finally send the file to the client
77  $evt = new Doku_Event('MEDIA_SENDFILE', $data);
78  if ($evt->advise_before()) {
79    sendFile($data['file'],$data['mime'],$data['download'],$data['cache']);
80  }
81  // Do something after the download finished.
82  $evt->advise_after();
83
84/* ------------------------------------------------------------------------ */
85
86/**
87 * Set headers and send the file to the client
88 *
89 * @author Andreas Gohr <andi@splitbrain.org>
90 * @author Ben Coburn <btcoburn@silicodon.net>
91 */
92function sendFile($file,$mime,$dl,$cache){
93  global $conf;
94  $fmtime = @filemtime($file);
95  // send headers
96  header("Content-Type: $mime");
97  // smart http caching headers
98  if ($cache==-1) {
99    // cache
100    // cachetime or one hour
101    header('Expires: '.gmdate("D, d M Y H:i:s", time()+max($conf['cachetime'], 3600)).' GMT');
102    header('Cache-Control: public, proxy-revalidate, no-transform, max-age='.max($conf['cachetime'], 3600));
103    header('Pragma: public');
104  } else if ($cache>0) {
105    // recache
106    // remaining cachetime + 10 seconds so the newly recached media is used
107    header('Expires: '.gmdate("D, d M Y H:i:s", $fmtime+$conf['cachetime']+10).' GMT');
108    header('Cache-Control: public, proxy-revalidate, no-transform, max-age='.max($fmtime-time()+$conf['cachetime']+10, 0));
109    header('Pragma: public');
110  } else if ($cache==0) {
111    // nocache
112    header('Cache-Control: must-revalidate, no-transform, post-check=0, pre-check=0');
113    header('Pragma: public');
114  }
115  //send important headers first, script stops here if '304 Not Modified' response
116  http_conditionalRequest($fmtime);
117
118
119  //download or display?
120  if($dl){
121    header('Content-Disposition: attachment; filename="'.basename($file).'";');
122  }else{
123    header('Content-Disposition: inline; filename="'.basename($file).'";');
124  }
125
126  //use x-sendfile header to pass the delivery to compatible webservers
127  if (http_sendfile($file)) exit;
128
129  // send file contents
130  $fp = @fopen($file,"rb");
131  if($fp){
132    http_rangeRequest($fp,filesize($file),$mime);
133  }else{
134    header("HTTP/1.0 500 Internal Server Error");
135    print "Could not read $file - bad permissions?";
136  }
137}
138
139/**
140 * Check for media for preconditions and return correct status code
141 *
142 * READ: MEDIA, MIME, EXT, CACHE
143 * WRITE: MEDIA, FILE, array( STATUS, STATUSMESSAGE )
144 *
145 * @author Gerry Weissbach <gerry.w@gammaproduction.de>
146 * @param $media reference to the media id
147 * @param $file reference to the file variable
148 * @returns array(STATUS, STATUSMESSAGE)
149 */
150function checkFileStatus(&$media, &$file) {
151  global $MIME, $EXT, $CACHE;
152
153  //media to local file
154  if(preg_match('#^(https?)://#i',$media)){
155    //check hash
156    if(substr(md5(auth_cookiesalt().$media),0,6) != $_REQUEST['hash']){
157      return array( 412, 'Precondition Failed');
158    }
159    //handle external images
160    if(strncmp($MIME,'image/',6) == 0) $file = media_get_from_URL($media,$EXT,$CACHE);
161    if(!$file){
162      //download failed - redirect to original URL
163      return array( 302, $media );
164    }
165  }else{
166    $media = cleanID($media);
167    if(empty($media)){
168      return array( 400, 'Bad request' );
169    }
170
171    //check permissions (namespace only)
172    if(auth_quickaclcheck(getNS($media).':X') < AUTH_READ){
173      return array( 403, 'Forbidden' );
174    }
175    $file  = mediaFN($media);
176  }
177
178  //check file existance
179  if(!@file_exists($file)){
180      return array( 404, 'Not Found' );
181  }
182
183  return array(200, null);
184}
185
186/**
187 * Returns the wanted cachetime in seconds
188 *
189 * Resolves named constants
190 *
191 * @author  Andreas Gohr <andi@splitbrain.org>
192 */
193function calc_cache($cache){
194  global $conf;
195
196  if(strtolower($cache) == 'nocache') return 0; //never cache
197  if(strtolower($cache) == 'recache') return $conf['cachetime']; //use standard cache
198  return -1; //cache endless
199}
200
201//Setup VIM: ex: et ts=2 :
202