xref: /dokuwiki/lib/exe/fetch.php (revision 8073bfb3ed64a1aa1f8477f4351c80ee841679f9) 
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  = getID('media',false); // no cleaning - maybe external
24  $CACHE  = calc_cache($_REQUEST['cache']);
25  $WIDTH  = $_REQUEST['w'];
26  $HEIGHT = $_REQUEST['h'];
27  list($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
187  //cache
188  $local = getCacheName($file,'.media.'.$w.'x'.$h.'.'.$ext);
189  $mtime = @filemtime($local); // 0 if not exists
190
191  if( $mtime > filemtime($file) ||
192      resize_imageIM($ext,$file,$info[0],$info[1],$local,$w,$h) ||
193      resize_imageGD($ext,$file,$info[0],$info[1],$local,$w,$h) ){
194    return $local;
195  }
196  //still here? resizing failed
197  return $file;
198}
199
200/**
201 * Returns the wanted cachetime in seconds
202 *
203 * Resolves named constants
204 *
205 * @author  Andreas Gohr <andi@splitbrain.org>
206 */
207function calc_cache($cache){
208  global $conf;
209
210  if(strtolower($cache) == 'nocache') return 0; //never cache
211  if(strtolower($cache) == 'recache') return $conf['cachetime']; //use standard cache
212  return -1; //cache endless
213}
214
215/**
216 * Download a remote file and return local filename
217 *
218 * returns false if download fails. Uses cached file if available and
219 * wanted
220 *
221 * @author  Andreas Gohr <andi@splitbrain.org>
222 * @author  Pavel Vitis <Pavel.Vitis@seznam.cz>
223 */
224function get_from_URL($url,$ext,$cache){
225  global $conf;
226
227  // if 'nocache' just redirect
228  if ($cache==0) { return false; }
229
230  $local = getCacheName(strtolower($url),".media.$ext");
231  $mtime = @filemtime($local); // 0 if not exists
232
233  //decide if download needed:
234  if( ($mtime == 0) ||                           // cache does not exist
235      ($cache != -1 && $mtime < time()-$cache)   // 'recache' and cache has expired
236    ){
237      if(io_download($url,$local)){
238        return $local;
239      }else{
240        return false;
241      }
242  }
243
244  //if cache exists use it else
245  if($mtime) return $local;
246
247  //else return false
248  return false;
249}
250
251/**
252 * resize images using external ImageMagick convert program
253 *
254 * @author Pavel Vitis <Pavel.Vitis@seznam.cz>
255 * @author Andreas Gohr <andi@splitbrain.org>
256 */
257function resize_imageIM($ext,$from,$from_w,$from_h,$to,$to_w,$to_h){
258  global $conf;
259
260  // check if convert is configured
261  if(!$conf['im_convert']) return false;
262
263  // prepare command
264  $cmd  = $conf['im_convert'];
265  $cmd .= ' -resize '.$to_w.'x'.$to_h.'!';
266  if ($ext == 'jpg' || $ext == 'jpeg') {
267      $cmd .= ' -quality '.$conf['jpg_quality'];
268  }
269  $cmd .= " $from $to";
270
271  @exec($cmd,$out,$retval);
272  if ($retval == 0) return true;
273
274  return false;
275}
276
277/**
278 * resize images using PHP's libGD support
279 *
280 * @author Andreas Gohr <andi@splitbrain.org>
281 */
282function resize_imageGD($ext,$from,$from_w,$from_h,$to,$to_w,$to_h){
283  global $conf;
284
285  if($conf['gdlib'] < 1) return false; //no GDlib available or wanted
286
287  // check available memory
288  if(!is_mem_available(($from_w * $from_h * 4) + ($to_w * $to_h * 4))){
289    return false;
290  }
291
292  // create an image of the given filetype
293  if ($ext == 'jpg' || $ext == 'jpeg'){
294    if(!function_exists("imagecreatefromjpeg")) return false;
295    $image = @imagecreatefromjpeg($from);
296  }elseif($ext == 'png') {
297    if(!function_exists("imagecreatefrompng")) return false;
298    $image = @imagecreatefrompng($from);
299
300  }elseif($ext == 'gif') {
301    if(!function_exists("imagecreatefromgif")) return false;
302    $image = @imagecreatefromgif($from);
303  }
304  if(!$image) return false;
305
306  if(($conf['gdlib']>1) && function_exists("imagecreatetruecolor")){
307    $newimg = @imagecreatetruecolor ($to_w, $to_h);
308  }
309  if(!$newimg) $newimg = @imagecreate($to_w, $to_h);
310  if(!$newimg){
311    imagedestroy($image);
312    return false;
313  }
314
315  //keep png alpha channel if possible
316  if($ext == 'png' && $conf['gdlib']>1 && function_exists('imagesavealpha')){
317    imagealphablending($newimg, false);
318    imagesavealpha($newimg,true);
319  }
320
321  //try resampling first
322  if(function_exists("imagecopyresampled")){
323    if(!@imagecopyresampled($newimg, $image, 0, 0, 0, 0, $to_w, $to_h, $from_w, $from_h)) {
324      imagecopyresized($newimg, $image, 0, 0, 0, 0, $to_w, $to_h, $from_w, $from_h);
325    }
326  }else{
327    imagecopyresized($newimg, $image, 0, 0, 0, 0, $to_w, $to_h, $from_w, $from_h);
328  }
329
330  $okay = false;
331  if ($ext == 'jpg' || $ext == 'jpeg'){
332    if(!function_exists('imagejpeg')){
333      $okay = false;
334    }else{
335      $okay = imagejpeg($newimg, $to, $conf['jpg_quality']);
336    }
337  }elseif($ext == 'png') {
338    if(!function_exists('imagepng')){
339      $okay = false;
340    }else{
341      $okay =  imagepng($newimg, $to);
342    }
343  }elseif($ext == 'gif') {
344    if(!function_exists('imagegif')){
345      $okay = false;
346    }else{
347      $okay = imagegif($newimg, $to);
348    }
349  }
350
351  // destroy GD image ressources
352  if($image) imagedestroy($image);
353  if($newimg) imagedestroy($newimg);
354
355  return $okay;
356}
357
358/**
359 * Checks if the given amount of memory is available
360 *
361 * If the memory_get_usage() function is not available the
362 * function just assumes $used bytes of already allocated memory
363 *
364 * @param  int $mem  Size of memory you want to allocate in bytes
365 * @param  int $used already allocated memory (see above)
366 * @author Filip Oscadal <webmaster@illusionsoftworks.cz>
367 * @author Andreas Gohr <andi@splitbrain.org>
368 */
369function is_mem_available($mem,$bytes=1048576){
370  $limit = trim(ini_get('memory_limit'));
371  if(empty($limit)) return true; // no limit set!
372
373  // parse limit to bytes
374  $unit = strtolower(substr($limit,-1));
375  switch($unit){
376    case 'g':
377      $limit = substr($limit,0,-1);
378      $limit *= 1024*1024*1024;
379      break;
380    case 'm':
381      $limit = substr($limit,0,-1);
382      $limit *= 1024*1024;
383      break;
384    case 'k':
385      $limit = substr($limit,0,-1);
386      $limit *= 1024;
387      break;
388  }
389
390  // get used memory if possible
391  if(function_exists('memory_get_usage')){
392    $used = memory_get_usage();
393  }
394
395
396  if($used+$mem > $limit){
397    return false;
398  }
399
400  return true;
401}
402
403//Setup VIM: ex: et ts=2 enc=utf-8 :
404?>
405