inc/fetch.functions.php

   1 <?php
   2 /**
   3  * Functions used by lib/exe/fetch.php
   4  * (not included by other parts of dokuwiki)
   5  */
   6
   7 /**
   8  * Set headers and send the file to the client
   9  *
  10  * The $cache parameter influences how long files may be kept in caches, the $public parameter
  11  * influences if this caching may happen in public proxis or in the browser cache only FS#2734
  12  *
  13  * This function will abort the current script when a 304 is sent or file sending is handled
  14  * through x-sendfile
  15  *
  16  * @author Andreas Gohr <andi@splitbrain.org>
  17  * @author Ben Coburn <btcoburn@silicodon.net>
  18  * @author Gerry Weissbach <dokuwiki@gammaproduction.de>
  19  *
  20  * @param string $file   local file to send
  21  * @param string $mime   mime type of the file
  22  * @param bool   $dl     set to true to force a browser download
  23  * @param int    $cache  remaining cache time in seconds (-1 for $conf['cache'], 0 for no-cache)
  24  * @param bool   $public is this a public ressource or a private one?
  25  * @param string $orig   original file to send - the file name will be used for the Content-Disposition
  26  */
  27 function sendFile($file, $mime, $dl, $cache, $public = false, $orig = null) {
  28     global $conf;
  29     // send mime headers
  30     header("Content-Type: $mime");
  31
  32     // calculate cache times
  33     if($cache == -1) {
  34         $maxage  = max($conf['cachetime'], 3600); // cachetime or one hour
  35         $expires = time() + $maxage;
  36     } else if($cache > 0) {
  37         $maxage  = $cache; // given time
  38         $expires = time() + $maxage;
  39     } else { // $cache == 0
  40         $maxage  = 0;
  41         $expires = 0; // 1970-01-01
  42     }
  43
  44     // smart http caching headers
  45     if($maxage) {
  46         if($public) {
  47             // cache publically
  48             header('Expires: '.gmdate("D, d M Y H:i:s", $expires).' GMT');
  49             header('Cache-Control: public, proxy-revalidate, no-transform, max-age='.$maxage);
  50         } else {
  51             // cache in browser
  52             header('Expires: '.gmdate("D, d M Y H:i:s", $expires).' GMT');
  53             header('Cache-Control: private, no-transform, max-age='.$maxage);
  54         }
  55     } else {
  56         // no cache at all
  57         header('Expires: Thu, 01 Jan 1970 00:00:00 GMT');
  58         header('Cache-Control: no-cache, no-transform');
  59     }
  60
  61     //send important headers first, script stops here if '304 Not Modified' response
  62     $fmtime = @filemtime($file);
  63     http_conditionalRequest($fmtime);
  64
  65     // Use the current $file if is $orig is not set.
  66     if ( $orig == null ) {
  67         $orig = $file;
  68     }
  69
  70     //download or display?
  71     if($dl) {
  72         header('Content-Disposition: attachment;'.rfc2231_encode('filename', utf8_basename($orig)).';');
  73     } else {
  74         header('Content-Disposition: inline;'.rfc2231_encode('filename', utf8_basename($orig)).';');
  75     }
  76
  77     //use x-sendfile header to pass the delivery to compatible webservers
  78     http_sendfile($file);
  79
  80     // send file contents
  81     $fp = @fopen($file, "rb");
  82     if($fp) {
  83         http_rangeRequest($fp, filesize($file), $mime);
  84     } else {
  85         http_status(500);
  86         print "Could not read $file - bad permissions?";
  87     }
  88 }
  89
  90 /**
  91  * Try an rfc2231 compatible encoding. This ensures correct
  92  * interpretation of filenames outside of the ASCII set.
  93  * This seems to be needed for file names with e.g. umlauts that
  94  * would otherwise decode wrongly in IE.
  95  *
  96  * There is no additional checking, just the encoding and setting the key=value for usage in headers
  97  *
  98  * @author Gerry Weissbach <gerry.w@gammaproduction.de>
  99  * @param string $name      name of the field to be set in the header() call
 100  * @param string $value     value of the field to be set in the header() call
 101  * @param string $charset   used charset for the encoding of value
 102  * @param string $lang      language used.
 103  * @return string           in the format " name=value" for values WITHOUT special characters
 104  * @return string           in the format " name*=charset'lang'value" for values WITH special characters
 105  */
 106 function rfc2231_encode($name, $value, $charset='utf-8', $lang='en') {
 107     $internal = preg_replace_callback('/[\x00-\x20*\'%()<>@,;:\\\\"\/[\]?=\x80-\xFF]/', function($match) { return rawurlencode($match[0]); }, $value);
 108     if ( $value != $internal ) {
 109         return ' '.$name.'*='.$charset."'".$lang."'".$internal;
 110     } else {
 111         return ' '.$name.'="'.$value.'"';
 112     }
 113 }
 114
 115 /**
 116  * Check for media for preconditions and return correct status code
 117  *
 118  * READ: MEDIA, MIME, EXT, CACHE
 119  * WRITE: MEDIA, FILE, array( STATUS, STATUSMESSAGE )
 120  *
 121  * @author Gerry Weissbach <gerry.w@gammaproduction.de>
 122  *
 123  * @param string $media  reference to the media id
 124  * @param string $file   reference to the file variable
 125  * @param string $rev
 126  * @param int    $width
 127  * @param int    $height
 128  * @return array as array(STATUS, STATUSMESSAGE)
 129  */
 130 function checkFileStatus(&$media, &$file, $rev = '', $width=0, $height=0) {
 131     global $MIME, $EXT, $CACHE, $INPUT;
 132
 133     //media to local file
 134     if(media_isexternal($media)) {
 135         //check token for external image and additional for resized and cached images
 136         if(media_get_token($media, $width, $height) !== $INPUT->str('tok')) {
 137             return array(412, 'Precondition Failed');
 138         }
 139         //handle external images
 140         if(strncmp($MIME, 'image/', 6) == 0) $file = media_get_from_URL($media, $EXT, $CACHE);
 141         if(!$file) {
 142             //download failed - redirect to original URL
 143             return array(302, $media);
 144         }
 145     } else {
 146         $media = cleanID($media);
 147         if(empty($media)) {
 148             return array(400, 'Bad request');
 149         }
 150         // check token for resized images
 151         if (($width || $height) && media_get_token($media, $width, $height) !== $INPUT->str('tok')) {
 152             return array(412, 'Precondition Failed');
 153         }
 154
 155         //check permissions (namespace only)
 156         if(auth_quickaclcheck(getNS($media).':X') < AUTH_READ) {
 157             return array(403, 'Forbidden');
 158         }
 159         $file = mediaFN($media, $rev);
 160     }
 161
 162     //check file existance
 163     if(!file_exists($file)) {
 164         return array(404, 'Not Found');
 165     }
 166
 167     return array(200, null);
 168 }
 169
 170 /**
 171  * Returns the wanted cachetime in seconds
 172  *
 173  * Resolves named constants
 174  *
 175  * @author  Andreas Gohr <andi@splitbrain.org>
 176  *
 177  * @param string $cache
 178  * @return int cachetime in seconds
 179  */
 180 function calc_cache($cache) {
 181     global $conf;
 182
 183     if(strtolower($cache) == 'nocache') return 0; //never cache
 184     if(strtolower($cache) == 'recache') return $conf['cachetime']; //use standard cache
 185     return -1; //cache endless
 186 }