xref: /dokuwiki/lib/exe/fetch.php (revision 894a80cc56d188b10cc78bb4c088bea731f991a2) 
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  define('DOKU_DISABLE_GZIP_OUTPUT', 1);
11  require_once(DOKU_INC.'inc/init.php');
12  require_once(DOKU_INC.'inc/common.php');
13  require_once(DOKU_INC.'inc/pageutils.php');
14  require_once(DOKU_INC.'inc/confutils.php');
15  require_once(DOKU_INC.'inc/auth.php');
16  //close sesseion
17  session_write_close();
18  if(!defined('CHUNK_SIZE')) define('CHUNK_SIZE',16*1024);
19
20  $mimetypes = getMimeTypes();
21
22  //get input
23  $MEDIA  = stripctl(getID('media',false)); // no cleaning except control chars - maybe external
24  $CACHE  = calc_cache($_REQUEST['cache']);
25  $WIDTH  = (int) $_REQUEST['w'];
26  $HEIGHT = (int) $_REQUEST['h'];
27  list($EXT,$MIME) = mimetype($MEDIA);
28  if($EXT === false){
29    $EXT  = 'unknown';
30    $MIME = 'application/octet-stream';
31  }
32
33  //media to local file
34  if(preg_match('#^(https?|ftp)://#i',$MEDIA)){
35    //handle external media
36    $FILE = get_from_URL($MEDIA,$EXT,$CACHE);
37    if(!$FILE){
38      //download failed - redirect to original URL
39      header('Location: '.$MEDIA);
40      exit;
41    }
42  }else{
43    $MEDIA = cleanID($MEDIA);
44    if(empty($MEDIA)){
45      header("HTTP/1.0 400 Bad Request");
46      print 'Bad request';
47      exit;
48    }
49
50    //check permissions (namespace only)
51    if(auth_quickaclcheck(getNS($MEDIA).':X') < AUTH_READ){
52      header("HTTP/1.0 401 Unauthorized");
53      //fixme add some image for imagefiles
54      print 'Unauthorized';
55      exit;
56    }
57    $FILE  = mediaFN($MEDIA);
58  }
59
60  //check file existance
61  if(!@file_exists($FILE)){
62    header("HTTP/1.0 404 Not Found");
63    //FIXME add some default broken image
64    print 'Not Found';
65    exit;
66  }
67
68  //handle image resizing
69  if((substr($MIME,0,5) == 'image') && $WIDTH){
70    $FILE = get_resized($FILE,$EXT,$WIDTH,$HEIGHT);
71  }
72
73  // finally send the file to the client
74  sendFile($FILE,$MIME,$CACHE);
75
76/* ------------------------------------------------------------------------ */
77
78/**
79 * Set headers and send the file to the client
80 *
81 * @author Andreas Gohr <andi@splitbrain.org>
82 * @author Ben Coburn <btcoburn@silicodon.net>
83 */
84function sendFile($file,$mime,$cache){
85  global $conf;
86  $fmtime = filemtime($file);
87  // send headers
88  header("Content-Type: $mime");
89  // smart http caching headers
90  if ($cache==-1) {
91    // cache
92    // cachetime or one hour
93    header('Expires: '.gmdate("D, d M Y H:i:s", time()+max($conf['cachetime'], 3600)).' GMT');
94    header('Cache-Control: public, proxy-revalidate, no-transform, max-age='.max($conf['cachetime'], 3600));
95    header('Pragma: public');
96  } else if ($cache>0) {
97    // recache
98    // remaining cachetime + 10 seconds so the newly recached media is used
99    header('Expires: '.gmdate("D, d M Y H:i:s", $fmtime+$conf['cachetime']+10).' GMT');
100    header('Cache-Control: public, proxy-revalidate, no-transform, max-age='.max($fmtime-time()+$conf['cachetime']+10, 0));
101    header('Pragma: public');
102  } else if ($cache==0) {
103    // nocache
104    header('Cache-Control: must-revalidate, no-transform, post-check=0, pre-check=0');
105    header('Pragma: public');
106  }
107  header('Accept-Ranges: bytes');
108  //send important headers first, script stops here if '304 Not Modified' response
109  http_conditionalRequest($fmtime);
110  list($start,$len) = http_rangeRequest(filesize($file));
111
112  //application mime type is downloadable
113  if(substr($mime,0,11) == 'application'){
114    header('Content-Disposition: attachment; filename="'.basename($file).'";');
115  }
116
117  // send file contents
118  $fp = @fopen($file,"rb");
119  if($fp){
120    fseek($fp,$start); //seek to start of range
121
122    $chunk = ($len > CHUNK_SIZE) ? CHUNK_SIZE : $len;
123    while (!feof($fp) && $chunk > 0) {
124      @set_time_limit(); // large files can take a lot of time
125      print fread($fp, $chunk);
126      flush();
127      $len -= $chunk;
128      $chunk = ($len > CHUNK_SIZE) ? CHUNK_SIZE : $len;
129    }
130    fclose($fp);
131  }else{
132    header("HTTP/1.0 500 Internal Server Error");
133    print "Could not read $file - bad permissions?";
134  }
135}
136
137/**
138 * Checks and sets headers to handle range requets
139 *
140 * @author  Andreas Gohr <andi@splitbrain.org>
141 * @returns array The start byte and the amount of bytes to send
142 */
143function http_rangeRequest($size){
144  if(!isset($_SERVER['HTTP_RANGE'])){
145    // no range requested - send the whole file
146    header("Content-Length: $size");
147    return array(0,$size);
148  }
149
150  $t = explode('=', $_SERVER['HTTP_RANGE']);
151  if (!$t[0]=='bytes') {
152    // we only understand byte ranges - send the whole file
153    header("Content-Length: $size");
154    return array(0,$size);
155  }
156
157  $r = explode('-', $t[1]);
158  $start = (int)$r[0];
159  $end = (int)$r[1];
160  if (!$end) $end = $size - 1;
161  if ($start > $end || $start > $size || $end > $size){
162    header('HTTP/1.1 416 Requested Range Not Satisfiable');
163    print 'Bad Range Request!';
164    exit;
165  }
166
167  $tot = $end - $start + 1;
168  header('HTTP/1.1 206 Partial Content');
169  header("Content-Range: bytes {$start}-{$end}/{$size}");
170  header("Content-Length: $tot");
171
172  return array($start,$tot);
173}
174
175/**
176 * Resizes the given image to the given size
177 *
178 * @author  Andreas Gohr <andi@splitbrain.org>
179 */
180function get_resized($file, $ext, $w, $h=0){
181  global $conf;
182
183  $info  = getimagesize($file);
184  if(!$h) $h = round(($w * $info[1]) / $info[0]);
185
186  // we wont scale up to infinity
187  if($w > 2000 || $h > 2000) return $file;
188
189  //cache
190  $local = getCacheName($file,'.media.'.$w.'x'.$h.'.'.$ext);
191  $mtime = @filemtime($local); // 0 if not exists
192
193  if( $mtime > filemtime($file) ||
194      resize_imageIM($ext,$file,$info[0],$info[1],$local,$w,$h) ||
195      resize_imageGD($ext,$file,$info[0],$info[1],$local,$w,$h) ){
196    return $local;
197  }
198  //still here? resizing failed
199  return $file;
200}
201
202/**
203 * Returns the wanted cachetime in seconds
204 *
205 * Resolves named constants
206 *
207 * @author  Andreas Gohr <andi@splitbrain.org>
208 */
209function calc_cache($cache){
210  global $conf;
211
212  if(strtolower($cache) == 'nocache') return 0; //never cache
213  if(strtolower($cache) == 'recache') return $conf['cachetime']; //use standard cache
214  return -1; //cache endless
215}
216
217/**
218 * Download a remote file and return local filename
219 *
220 * returns false if download fails. Uses cached file if available and
221 * wanted
222 *
223 * @author  Andreas Gohr <andi@splitbrain.org>
224 * @author  Pavel Vitis <Pavel.Vitis@seznam.cz>
225 */
226function get_from_URL($url,$ext,$cache){
227  global $conf;
228
229  // if no cache or fetchsize just redirect
230  if ($cache==0)           return false;
231  if (!$conf['fetchsize']) return false;
232
233  $local = getCacheName(strtolower($url),".media.$ext");
234  $mtime = @filemtime($local); // 0 if not exists
235
236  //decide if download needed:
237  if( ($mtime == 0) ||                           // cache does not exist
238      ($cache != -1 && $mtime < time()-$cache)   // 'recache' and cache has expired
239    ){
240      if(image_download($url,$local)){
241        return $local;
242      }else{
243        return false;
244      }
245  }
246
247  //if cache exists use it else
248  if($mtime) return $local;
249
250  //else return false
251  return false;
252}
253
254/**
255 * Download image files
256 *
257 * @author Andreas Gohr <andi@splitbrain.org>
258 */
259function image_download($url,$file){
260  global $conf;
261  $http = new DokuHTTPClient();
262  $http->max_bodysize = $conf['fetchsize'];
263  $http->timeout = 25; //max. 25 sec
264  $http->header_regexp = '!\r\nContent-Type: image/(jpe?g|gif|png)!i';
265
266  $data = $http->get($url);
267  if(!$data) return false;
268
269  $fileexists = @file_exists($file);
270  $fp = @fopen($file,"w");
271  if(!$fp) return false;
272  fwrite($fp,$data);
273  fclose($fp);
274  if(!$fileexists and $conf['fperm']) chmod($file, $conf['fperm']);
275  return true;
276}
277
278/**
279 * resize images using external ImageMagick convert program
280 *
281 * @author Pavel Vitis <Pavel.Vitis@seznam.cz>
282 * @author Andreas Gohr <andi@splitbrain.org>
283 */
284function resize_imageIM($ext,$from,$from_w,$from_h,$to,$to_w,$to_h){
285  global $conf;
286
287  // check if convert is configured
288  if(!$conf['im_convert']) return false;
289
290  // prepare command
291  $cmd  = $conf['im_convert'];
292  $cmd .= ' -resize '.$to_w.'x'.$to_h.'!';
293  if ($ext == 'jpg' || $ext == 'jpeg') {
294      $cmd .= ' -quality '.$conf['jpg_quality'];
295  }
296  $cmd .= " $from $to";
297
298  @exec($cmd,$out,$retval);
299  if ($retval == 0) return true;
300  return false;
301}
302
303/**
304 * resize images using PHP's libGD support
305 *
306 * @author Andreas Gohr <andi@splitbrain.org>
307 */
308function resize_imageGD($ext,$from,$from_w,$from_h,$to,$to_w,$to_h){
309  global $conf;
310
311  if($conf['gdlib'] < 1) return false; //no GDlib available or wanted
312
313  // check available memory
314  if(!is_mem_available(($from_w * $from_h * 4) + ($to_w * $to_h * 4))){
315    return false;
316  }
317
318  // create an image of the given filetype
319  if ($ext == 'jpg' || $ext == 'jpeg'){
320    if(!function_exists("imagecreatefromjpeg")) return false;
321    $image = @imagecreatefromjpeg($from);
322  }elseif($ext == 'png') {
323    if(!function_exists("imagecreatefrompng")) return false;
324    $image = @imagecreatefrompng($from);
325
326  }elseif($ext == 'gif') {
327    if(!function_exists("imagecreatefromgif")) return false;
328    $image = @imagecreatefromgif($from);
329  }
330  if(!$image) return false;
331
332  if(($conf['gdlib']>1) && function_exists("imagecreatetruecolor")){
333    $newimg = @imagecreatetruecolor ($to_w, $to_h);
334  }
335  if(!$newimg) $newimg = @imagecreate($to_w, $to_h);
336  if(!$newimg){
337    imagedestroy($image);
338    return false;
339  }
340
341  //keep png alpha channel if possible
342  if($ext == 'png' && $conf['gdlib']>1 && function_exists('imagesavealpha')){
343    imagealphablending($newimg, false);
344    imagesavealpha($newimg,true);
345  }
346
347  //try resampling first
348  if(function_exists("imagecopyresampled")){
349    if(!@imagecopyresampled($newimg, $image, 0, 0, 0, 0, $to_w, $to_h, $from_w, $from_h)) {
350      imagecopyresized($newimg, $image, 0, 0, 0, 0, $to_w, $to_h, $from_w, $from_h);
351    }
352  }else{
353    imagecopyresized($newimg, $image, 0, 0, 0, 0, $to_w, $to_h, $from_w, $from_h);
354  }
355
356  $okay = false;
357  if ($ext == 'jpg' || $ext == 'jpeg'){
358    if(!function_exists('imagejpeg')){
359      $okay = false;
360    }else{
361      $okay = imagejpeg($newimg, $to, $conf['jpg_quality']);
362    }
363  }elseif($ext == 'png') {
364    if(!function_exists('imagepng')){
365      $okay = false;
366    }else{
367      $okay =  imagepng($newimg, $to);
368    }
369  }elseif($ext == 'gif') {
370    if(!function_exists('imagegif')){
371      $okay = false;
372    }else{
373      $okay = imagegif($newimg, $to);
374    }
375  }
376
377  // destroy GD image ressources
378  if($image) imagedestroy($image);
379  if($newimg) imagedestroy($newimg);
380
381  return $okay;
382}
383
384/**
385 * Checks if the given amount of memory is available
386 *
387 * If the memory_get_usage() function is not available the
388 * function just assumes $used bytes of already allocated memory
389 *
390 * @param  int $mem  Size of memory you want to allocate in bytes
391 * @param  int $used already allocated memory (see above)
392 * @author Filip Oscadal <webmaster@illusionsoftworks.cz>
393 * @author Andreas Gohr <andi@splitbrain.org>
394 */
395function is_mem_available($mem,$bytes=1048576){
396  $limit = trim(ini_get('memory_limit'));
397  if(empty($limit)) return true; // no limit set!
398
399  // parse limit to bytes
400  $unit = strtolower(substr($limit,-1));
401  switch($unit){
402    case 'g':
403      $limit = substr($limit,0,-1);
404      $limit *= 1024*1024*1024;
405      break;
406    case 'm':
407      $limit = substr($limit,0,-1);
408      $limit *= 1024*1024;
409      break;
410    case 'k':
411      $limit = substr($limit,0,-1);
412      $limit *= 1024;
413      break;
414  }
415
416  // get used memory if possible
417  if(function_exists('memory_get_usage')){
418    $used = memory_get_usage();
419  }
420
421
422  if($used+$mem > $limit){
423    return false;
424  }
425
426  return true;
427}
428
429//Setup VIM: ex: et ts=2 enc=utf-8 :
430?>
431