xref: /dokuwiki/lib/exe/fetch.php (revision 1d3e0272316696a8def74759b5e061d6b8387b5f) 
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',realpath(dirname(__FILE__).'/../../').'/');
10  require_once(DOKU_INC.'inc/init.php');
11  require_once(DOKU_INC.'inc/common.php');
12  require_once(DOKU_INC.'inc/pageutils.php');
13  require_once(DOKU_INC.'inc/confutils.php');
14  require_once(DOKU_INC.'inc/auth.php');
15  //close sesseion
16  session_write_close();
17
18  $mimetypes = getMimeTypes();
19
20  //get input
21  $MEDIA  = getID('media',false); // no cleaning - maybe external
22  $CACHE  = calc_cache($_REQUEST['cache']);
23  $WIDTH  = $_REQUEST['w'];
24  $HEIGHT = $_REQUEST['h'];
25  list($EXT,$MIME) = mimetype($MEDIA);
26  if($EXT === false){
27    $EXT  = 'unknown';
28    $MIME = 'application/octet-stream';
29  }
30
31  //media to local file
32  if(preg_match('#^(https?|ftp)://#i',$MEDIA)){
33    //handle external media
34    $FILE = get_from_URL($MEDIA,$EXT,$CACHE);
35    if(!$FILE){
36      //download failed - redirect to original URL
37      header('Location: '.$MEDIA);
38      exit;
39    }
40  }else{
41    $MEDIA = cleanID($MEDIA);
42    if(empty($MEDIA)){
43      header("HTTP/1.0 400 Bad Request");
44      print 'Bad request';
45      exit;
46    }
47
48    //check permissions (namespace only)
49    if(auth_quickaclcheck(getNS($MEDIA).':X') < AUTH_READ){
50      header("HTTP/1.0 401 Unauthorized");
51      //fixme add some image for imagefiles
52      print 'Unauthorized';
53      exit;
54    }
55    $FILE  = mediaFN($MEDIA);
56  }
57
58  //check file existance
59  if(!@file_exists($FILE)){
60    header("HTTP/1.0 404 Not Found");
61    //FIXME add some default broken image
62    print 'Not Found';
63    exit;
64  }
65
66  //handle image resizing
67  if((substr($MIME,0,5) == 'image') && $WIDTH){
68    $FILE = get_resized($FILE,$EXT,$WIDTH,$HEIGHT);
69  }
70
71
72  //FIXME set sane cachecontrol headers
73  //FIXME handle conditional and partial requests
74
75  //send file
76  header("Content-Type: $MIME");
77  header('Last-Modified: '.date('r',filemtime($FILE)));
78  header('Content-Length: '.filesize($FILE));
79  header('Cache-Control: private, must-revalidate, post-check=0, pre-check=0');
80
81  //application mime type is downloadable
82  if(substr($MIME,0,11) == 'application'){
83    header('Content-Disposition: attachment; filename="'.basename($FILE).'"');
84  }
85
86  $fp = @fopen($FILE,"rb");
87  if($fp){
88    while (!feof($fp)) {
89      @set_time_limit(); // large files can take a lot of time
90      print fread($fp, 16*1024);
91      flush();
92    }
93    fclose($fp);
94  }else{
95    header("HTTP/1.0 500 Internal Server Error");
96    print "Could not read $FILE - bad permissions?";
97  }
98
99/* ------------------------------------------------------------------------ */
100
101/**
102 * Resizes the given image to the given size
103 *
104 * @author  Andreas Gohr <andi@splitbrain.org>
105 */
106function get_resized($file, $ext, $w, $h=0){
107  global $conf;
108
109  $info  = getimagesize($file);
110  if(!$h) $h = round(($w * $info[1]) / $info[0]);
111
112
113  //cache
114  $local = getCacheName($file,'.media.'.$w.'x'.$h.'.'.$ext);
115  $mtime = @filemtime($local); // 0 if not exists
116
117  if( $mtime > filemtime($file) ||
118      resize_imageIM($ext,$file,$info[0],$info[1],$local,$w,$h) ||
119      resize_imageGD($ext,$file,$info[0],$info[1],$local,$w,$h) ){
120    return $local;
121  }
122  //still here? resizing failed
123  return $file;
124}
125
126/**
127 * Returns the wanted cachetime in seconds
128 *
129 * Resolves named constants
130 *
131 * @author  Andreas Gohr <andi@splitbrain.org>
132 */
133function calc_cache($cache){
134  global $conf;
135
136  if(strtolower($cache) == 'nocache') return 0; //never cache
137  if(strtolower($cache) == 'recache') return $conf['cachetime']; //use standard cache
138  return -1; //cache endless
139}
140
141/**
142 * Download a remote file and return local filename
143 *
144 * returns false if download fails. Uses cached file if available and
145 * wanted
146 *
147 * @author  Andreas Gohr <andi@splitbrain.org>
148 * @author  Pavel Vitis <Pavel.Vitis@seznam.cz>
149 */
150function get_from_URL($url,$ext,$cache){
151  global $conf;
152
153  $local = getCacheName(strtolower($url),".media.$ext");
154  $mtime = @filemtime($local); // 0 if not exists
155
156  //decide if download needed:
157  if( $cache == 0 ||                             // never cache
158      ($mtime != 0 && $cache != -1) ||           // exists but no endless cache
159      ($mtime == 0) ||                           // not exists
160      ($cache != -1 && $mtime < time()-$cache)   // expired
161    ){
162      if(io_download($url,$local)){
163        return $local;
164      }else{
165        return false;
166      }
167  }
168
169  //if cache exists use it else
170  if($mtime) return $local;
171
172  //else return false
173  return false;
174}
175
176/**
177 * resize images using external ImageMagick convert program
178 *
179 * @author Pavel Vitis <Pavel.Vitis@seznam.cz>
180 * @author Andreas Gohr <andi@splitbrain.org>
181 */
182function resize_imageIM($ext,$from,$from_w,$from_h,$to,$to_w,$to_h){
183  global $conf;
184
185  // check if convert is configured
186  if(!$conf['im_convert']) return false;
187
188  // prepare command
189  $cmd  = $conf['im_convert'];
190  $cmd .= ' -resize '.$to_w.'x'.$to_h.'!';
191  $cmd .= " $from $to";
192
193  @exec($cmd,$out,$retval);
194  if ($retval == 0) return true;
195
196  return false;
197}
198
199/**
200 * resize images using PHP's libGD support
201 *
202 * @author Andreas Gohr <andi@splitbrain.org>
203 */
204function resize_imageGD($ext,$from,$from_w,$from_h,$to,$to_w,$to_h){
205  global $conf;
206
207  if($conf['gdlib'] < 1) return false; //no GDlib available or wanted
208
209  // check available memory
210  if(!is_mem_available(($from_w * $from_h * 4) + ($to_w * $to_h * 4))){
211    return false;
212  }
213
214  // create an image of the given filetype
215  if ($ext == 'jpg' || $ext == 'jpeg'){
216    if(!function_exists("imagecreatefromjpeg")) return false;
217    $image = @imagecreatefromjpeg($from);
218  }elseif($ext == 'png') {
219    if(!function_exists("imagecreatefrompng")) return false;
220    $image = @imagecreatefrompng($from);
221
222  }elseif($ext == 'gif') {
223    if(!function_exists("imagecreatefromgif")) return false;
224    $image = @imagecreatefromgif($from);
225  }
226  if(!$image) return false;
227
228  if(($conf['gdlib']>1) && function_exists("imagecreatetruecolor")){
229    $newimg = @imagecreatetruecolor ($to_w, $to_h);
230  }
231  if(!$newimg) $newimg = @imagecreate($to_w, $to_h);
232  if(!$newimg){
233    imagedestroy($image);
234    return false;
235  }
236
237  //keep png alpha channel if possible
238  if($ext == 'png' && $conf['gdlib']>1 && function_exists('imagesavealpha')){
239    imagealphablending($newimg, false);
240    imagesavealpha($newimg,true);
241  }
242
243  //try resampling first
244  if(function_exists("imagecopyresampled")){
245    if(!@imagecopyresampled($newimg, $image, 0, 0, 0, 0, $to_w, $to_h, $from_w, $from_h)) {
246      imagecopyresized($newimg, $image, 0, 0, 0, 0, $to_w, $to_h, $from_w, $from_h);
247    }
248  }else{
249    imagecopyresized($newimg, $image, 0, 0, 0, 0, $to_w, $to_h, $from_w, $from_h);
250  }
251
252  $okay = false;
253  if ($ext == 'jpg' || $ext == 'jpeg'){
254    if(!function_exists('imagejpeg')){
255      $okay = false;
256    }else{
257      $okay = imagejpeg($newimg, $to, 70);
258    }
259  }elseif($ext == 'png') {
260    if(!function_exists('imagepng')){
261      $okay = false;
262    }else{
263      $okay =  imagepng($newimg, $to);
264    }
265  }elseif($ext == 'gif') {
266    if(!function_exists('imagegif')){
267      $okay = false;
268    }else{
269      $okay = imagegif($newimg, $to);
270    }
271  }
272
273  // destroy GD image ressources
274  if($image) imagedestroy($image);
275  if($newimg) imagedestroy($newimg);
276
277  return $okay;
278}
279
280/**
281 * Checks if the given amount of memory is available
282 *
283 * If the memory_get_usage() function is not available the
284 * function just assumes $used bytes of already allocated memory
285 *
286 * @param  int $mem  Size of memory you want to allocate in bytes
287 * @param  int $used already allocated memory (see above)
288 * @author Filip Oscadal <webmaster@illusionsoftworks.cz>
289 * @author Andreas Gohr <andi@splitbrain.org>
290 */
291function is_mem_available($mem,$bytes=1048576){
292  $limit = trim(ini_get('memory_limit'));
293  if(empty($limit)) return true; // no limit set!
294
295  // parse limit to bytes
296  $unit = strtolower(substr($limit,-1));
297  switch($unit){
298    case 'g':
299      $limit = substr($limit,0,-1);
300      $limit *= 1024*1024*1024;
301      break;
302    case 'm':
303      $limit = substr($limit,0,-1);
304      $limit *= 1024*1024;
305      break;
306    case 'k':
307      $limit = substr($limit,0,-1);
308      $limit *= 1024;
309      break;
310  }
311
312  // get used memory if possible
313  if(function_exists('memory_get_usage')){
314    $used = memory_get_usage();
315  }
316
317
318  if($used+$mem > $limit){
319    return false;
320  }
321
322  return true;
323}
324
325//Setup VIM: ex: et ts=2 enc=utf-8 :
326?>
327