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Long Term Support Release

  • Bug fixes for general core bugs in 3.9.x will end* 10 May 2021 (12 months).
  • Bug fixes for security issues in 3.9.x will end* 8 May 2023 (36 months).
  • PHP version: minimum PHP 7.2.0 Note: minimum PHP version has increased since Moodle 3.8. PHP 7.3.x and 7.4.x are supported too.
  • /theme/ -> image.php (source)

    Differences Between: [Versions 32 and 39]

       1  <?php
       2  // This file is part of Moodle - http://moodle.org/
       3  //
       4  // Moodle is free software: you can redistribute it and/or modify
       5  // it under the terms of the GNU General Public License as published by
       6  // the Free Software Foundation, either version 3 of the License, or
       7  // (at your option) any later version.
       8  //
       9  // Moodle is distributed in the hope that it will be useful,
      10  // but WITHOUT ANY WARRANTY; without even the implied warranty of
      11  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      12  // GNU General Public License for more details.
      13  //
      14  // You should have received a copy of the GNU General Public License
      15  // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
      16  
      17  /**
      18   * This file is responsible for serving the one theme and plugin images.
      19   *
      20   * @package   core
      21   * @copyright 2009 Petr Skoda (skodak)  {@link http://skodak.org}
      22   * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
      23   */
      24  
      25  
      26  // disable moodle specific debug messages and any errors in output,
      27  // comment out when debugging or better look into error log!
      28  define('NO_DEBUG_DISPLAY', true);
      29  
      30  // we need just the values from config.php and minlib.php
      31  define('ABORT_AFTER_CONFIG', true);
      32  require('../config.php'); // this stops immediately at the beginning of lib/setup.php
      33  
      34  if ($slashargument = min_get_slash_argument()) {
      35      $slashargument = ltrim($slashargument, '/');
      36      if (substr_count($slashargument, '/') < 3) {
      37          image_not_found();
      38      }
      39      if (strpos($slashargument, '_s/') === 0) {
      40          // Can't use SVG
      41          $slashargument = substr($slashargument, 3);
      42          $usesvg = false;
      43      } else {
      44          $usesvg = true;
      45      }
      46      // image must be last because it may contain "/"
      47      list($themename, $component, $rev, $image) = explode('/', $slashargument, 4);
      48      $themename = min_clean_param($themename, 'SAFEDIR');
      49      $component = min_clean_param($component, 'SAFEDIR');
      50      $rev       = min_clean_param($rev, 'INT');
      51      $image     = min_clean_param($image, 'SAFEPATH');
      52  
      53  } else {
      54      $themename = min_optional_param('theme', 'standard', 'SAFEDIR');
      55      $component = min_optional_param('component', 'core', 'SAFEDIR');
      56      $rev       = min_optional_param('rev', -1, 'INT');
      57      $image     = min_optional_param('image', '', 'SAFEPATH');
      58      $usesvg    = (bool)min_optional_param('svg', '1', 'INT');
      59  }
      60  
      61  if (empty($component) or $component === 'moodle' or $component === 'core') {
      62      $component = 'core';
      63  }
      64  
      65  if (empty($image)) {
      66      image_not_found();
      67  }
      68  
      69  if (file_exists("$CFG->dirroot/theme/$themename/config.php")) {
      70      // exists
      71  } else if (!empty($CFG->themedir) and file_exists("$CFG->themedir/$themename/config.php")) {
      72      // exists
      73  } else {
      74      image_not_found();
      75  }
      76  
      77  $candidatelocation = "$CFG->localcachedir/theme/$rev/$themename/pix/$component";
      78  $etag = sha1("$rev/$themename/$component/$image");
      79  
      80  if ($rev > 0) {
      81      if (file_exists("$candidatelocation/$image.error")) {
      82          // This is a major speedup if there are multiple missing images,
      83          // the only problem is that random requests may pollute our cache.
      84          image_not_found();
      85      }
      86      $cacheimage = false;
      87      if ($usesvg && file_exists("$candidatelocation/$image.svg")) {
      88          $cacheimage = "$candidatelocation/$image.svg";
      89          $ext = 'svg';
      90      } else if (file_exists("$candidatelocation/$image.png")) {
      91          $cacheimage = "$candidatelocation/$image.png";
      92          $ext = 'png';
      93      } else if (file_exists("$candidatelocation/$image.gif")) {
      94          $cacheimage = "$candidatelocation/$image.gif";
      95          $ext = 'gif';
      96      } else if (file_exists("$candidatelocation/$image.jpg")) {
      97          $cacheimage = "$candidatelocation/$image.jpg";
      98          $ext = 'jpg';
      99      } else if (file_exists("$candidatelocation/$image.jpeg")) {
     100          $cacheimage = "$candidatelocation/$image.jpeg";
     101          $ext = 'jpeg';
     102      } else if (file_exists("$candidatelocation/$image.ico")) {
     103          $cacheimage = "$candidatelocation/$image.ico";
     104          $ext = 'ico';
     105      }
     106      if ($cacheimage) {
     107          if (!empty($_SERVER['HTTP_IF_NONE_MATCH']) || !empty($_SERVER['HTTP_IF_MODIFIED_SINCE'])) {
     108              // We do not actually need to verify the etag value because our files
     109              // never change in cache because we increment the rev parameter.
     110              // 90 days only - based on Moodle point release cadence being every 3 months.
     111              $lifetime = 60 * 60 * 24 * 90;
     112              $mimetype = get_contenttype_from_ext($ext);
     113              header('HTTP/1.1 304 Not Modified');
     114              header('Expires: '. gmdate('D, d M Y H:i:s', time() + $lifetime) .' GMT');
     115              header('Cache-Control: public, max-age='.$lifetime.', no-transform');
     116              header('Content-Type: '.$mimetype);
     117              header('Etag: "'.$etag.'"');
     118              die;
     119          }
     120          send_cached_image($cacheimage, $etag);
     121      }
     122  }
     123  
     124  //=================================================================================
     125  // ok, now we need to start normal moodle script, we need to load all libs and $DB
     126  define('ABORT_AFTER_CONFIG_CANCEL', true);
     127  
     128  define('NO_MOODLE_COOKIES', true); // Session not used here
     129  define('NO_UPGRADE_CHECK', true);  // Ignore upgrade check
     130  
     131  require("$CFG->dirroot/lib/setup.php");
     132  
     133  $theme = theme_config::load($themename);
     134  $themerev = theme_get_revision();
     135  
     136  if ($themerev <= 0 or $rev != $themerev) {
     137      // Do not send caching headers if they do not request current revision,
     138      // we do not want to pollute browser caches with outdated images.
     139      $imagefile = $theme->resolve_image_location($image, $component, $usesvg);
     140      if (empty($imagefile) or !is_readable($imagefile)) {
     141          image_not_found();
     142      }
     143      send_uncached_image($imagefile);
     144  }
     145  
     146  make_localcache_directory('theme', false);
     147  
     148  // At this stage caching is enabled, and either:
     149  // * we have no cached copy of the image in any format (either SVG, or non-SVG); or
     150  // * we have a cached copy of the SVG, but the non-SVG was requested by the browser.
     151  //
     152  // Because of the way in which the cache return code works above:
     153  // * if we are allowed to return SVG, we do not need to cache the non-SVG version; however
     154  // * if the browser has requested the non-SVG version, we *must* cache _both_ the SVG, and the non-SVG versions.
     155  
     156  // First get all copies - including, potentially, the SVG version.
     157  $imagefile = $theme->resolve_image_location($image, $component, true);
     158  
     159  if (empty($imagefile) || !is_readable($imagefile)) {
     160      // Unable to find a copy of the image file in any format.
     161      // We write a .error file for the image now - this will be used above when searching for cached copies to prevent
     162      // trying to find the image in the future.
     163      if (!file_exists($candidatelocation)) {
     164          @mkdir($candidatelocation, $CFG->directorypermissions, true);
     165      }
     166      // Make note we can not find this file.
     167      $cacheimage = "$candidatelocation/$image.error";
     168      $fp = fopen($cacheimage, 'w');
     169      fclose($fp);
     170      image_not_found();
     171  }
     172  
     173  // The image was found, and it is readable.
     174  $pathinfo = pathinfo($imagefile);
     175  
     176  // Attempt to cache it if necessary.
     177  // We don't really want to overwrite any existing cache items just for the sake of it.
     178  $cacheimage = "$candidatelocation/$image.{$pathinfo['extension']}";
     179  if (!file_exists($cacheimage)) {
     180      // We don't already hold a cached copy of this image. Cache it now.
     181      $cacheimage = cache_image($image, $imagefile, $candidatelocation);
     182  }
     183  
     184  if (!$usesvg && $pathinfo['extension'] === 'svg') {
     185      // The browser has requested that a non-SVG version be returned.
     186      // The version found so far is the SVG version - try and find the non-SVG version.
     187      $imagefile = $theme->resolve_image_location($image, $component, false);
     188      if (empty($imagefile) || !is_readable($imagefile)) {
     189          // A non-SVG file could not be found at all.
     190          // The browser has requested a non-SVG version, so we must return image_not_found().
     191          // We must *not* write an .error file because the SVG is available.
     192          image_not_found();
     193      }
     194  
     195      // An non-SVG version of image was found - cache it.
     196      // This will be used below in the image serving code.
     197      $cacheimage = cache_image($image, $imagefile, $candidatelocation);
     198  }
     199  
     200  if (connection_aborted()) {
     201      // Request was cancelled - do not send anything.
     202      die;
     203  }
     204  
     205  // Make sure nothing failed.
     206  clearstatcache();
     207  if (file_exists($cacheimage)) {
     208      // The cached copy was found, and is accessible. Serve it.
     209      send_cached_image($cacheimage, $etag);
     210  }
     211  
     212  send_uncached_image($imagefile);
     213  
     214  //=================================================================================
     215  //=== utility functions ==
     216  // we are not using filelib because we need to fine tune all header
     217  // parameters to get the best performance.
     218  
     219  function send_cached_image($imagepath, $etag) {
     220      global $CFG;
     221      require("$CFG->dirroot/lib/xsendfilelib.php");
     222  
     223      // 90 days only - based on Moodle point release cadence being every 3 months.
     224      $lifetime = 60 * 60 * 24 * 90;
     225      $pathinfo = pathinfo($imagepath);
     226      $imagename = $pathinfo['filename'].'.'.$pathinfo['extension'];
     227  
     228      $mimetype = get_contenttype_from_ext($pathinfo['extension']);
     229  
     230      header('Etag: "'.$etag.'"');
     231      header('Content-Disposition: inline; filename="'.$imagename.'"');
     232      header('Last-Modified: '. gmdate('D, d M Y H:i:s', filemtime($imagepath)) .' GMT');
     233      header('Expires: '. gmdate('D, d M Y H:i:s', time() + $lifetime) .' GMT');
     234      header('Pragma: ');
     235      header('Cache-Control: public, max-age='.$lifetime.', no-transform, immutable');
     236      header('Accept-Ranges: none');
     237      header('Content-Type: '.$mimetype);
     238  
     239      if (xsendfile($imagepath)) {
     240          die;
     241      }
     242  
     243      if ($mimetype === 'image/svg+xml') {
     244          // SVG format is a text file. So we can compress SVG files.
     245          if (!min_enable_zlib_compression()) {
     246              header('Content-Length: '.filesize($imagepath));
     247          }
     248      } else {
     249          // No need to compress other image formats.
     250          header('Content-Length: '.filesize($imagepath));
     251      }
     252  
     253      readfile($imagepath);
     254      die;
     255  }
     256  
     257  function send_uncached_image($imagepath) {
     258      $pathinfo = pathinfo($imagepath);
     259      $imagename = $pathinfo['filename'].'.'.$pathinfo['extension'];
     260  
     261      $mimetype = get_contenttype_from_ext($pathinfo['extension']);
     262  
     263      header('Content-Disposition: inline; filename="'.$imagename.'"');
     264      header('Last-Modified: '. gmdate('D, d M Y H:i:s', time()) .' GMT');
     265      header('Expires: '. gmdate('D, d M Y H:i:s', time() + 15) .' GMT');
     266      header('Pragma: ');
     267      header('Accept-Ranges: none');
     268      header('Content-Type: '.$mimetype);
     269      header('Content-Length: '.filesize($imagepath));
     270  
     271      readfile($imagepath);
     272      die;
     273  }
     274  
     275  function image_not_found() {
     276      header('HTTP/1.0 404 not found');
     277      die('Image was not found, sorry.');
     278  }
     279  
     280  function get_contenttype_from_ext($ext) {
     281      switch ($ext) {
     282          case 'svg':
     283              return 'image/svg+xml';
     284          case 'png':
     285              return 'image/png';
     286          case 'gif':
     287              return 'image/gif';
     288          case 'jpg':
     289          case 'jpeg':
     290              return 'image/jpeg';
     291          case 'ico':
     292              return 'image/vnd.microsoft.icon';
     293      }
     294      return 'document/unknown';
     295  }
     296  
     297  /**
     298   * Caches a given image file.
     299   *
     300   * @param string $image The name of the image that was requested.
     301   * @param string $imagefile The location of the image file we want to cache.
     302   * @param string $candidatelocation The location to cache it in.
     303   * @return string The path to the cached image.
     304   */
     305  function cache_image($image, $imagefile, $candidatelocation) {
     306      global $CFG;
     307      $pathinfo = pathinfo($imagefile);
     308      $cacheimage = "$candidatelocation/$image.".$pathinfo['extension'];
     309  
     310      clearstatcache();
     311      if (!file_exists(dirname($cacheimage))) {
     312          @mkdir(dirname($cacheimage), $CFG->directorypermissions, true);
     313      }
     314  
     315      // Prevent serving of incomplete file from concurrent request,
     316      // the rename() should be more atomic than copy().
     317      ignore_user_abort(true);
     318      if (@copy($imagefile, $cacheimage.'.tmp')) {
     319          rename($cacheimage.'.tmp', $cacheimage);
     320          @chmod($cacheimage, $CFG->filepermissions);
     321          @unlink($cacheimage.'.tmp'); // just in case anything fails
     322      }
     323      return $cacheimage;
     324  }
    

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