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   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              $lifetime = 60*60*24*60; // 60 days only - the revision may get incremented quite often
 111              $mimetype = get_contenttype_from_ext($ext);
 112              header('HTTP/1.1 304 Not Modified');
 113              header('Expires: '. gmdate('D, d M Y H:i:s', time() + $lifetime) .' GMT');
 114              header('Cache-Control: public, max-age='.$lifetime.', no-transform');
 115              header('Content-Type: '.$mimetype);
 116              header('Etag: "'.$etag.'"');
 117              die;
 118          }
 119          send_cached_image($cacheimage, $etag);
 120      }
 121  }
 122  
 123  //=================================================================================
 124  // ok, now we need to start normal moodle script, we need to load all libs and $DB
 125  define('ABORT_AFTER_CONFIG_CANCEL', true);
 126  
 127  define('NO_MOODLE_COOKIES', true); // Session not used here
 128  define('NO_UPGRADE_CHECK', true);  // Ignore upgrade check
 129  
 130  require("$CFG->dirroot/lib/setup.php");
 131  
 132  $theme = theme_config::load($themename);
 133  $themerev = theme_get_revision();
 134  
 135  if ($themerev <= 0 or $rev != $themerev) {
 136      // Do not send caching headers if they do not request current revision,
 137      // we do not want to pollute browser caches with outdated images.
 138      $imagefile = $theme->resolve_image_location($image, $component, $usesvg);
 139      if (empty($imagefile) or !is_readable($imagefile)) {
 140          image_not_found();
 141      }
 142      send_uncached_image($imagefile);
 143  }
 144  
 145  make_localcache_directory('theme', false);
 146  
 147  // We're not using SVG and there is no cached version of this file (in any format).
 148  // As we're going to be caching a format other than svg, and because svg use is conditional we need to ensure that at the same
 149  // time we cache a version of the SVG if it exists. If we don't do this other users who ask for SVG would not ever get it as
 150  // there is a cached image already of another format.
 151  // Remember this only gets run once before any candidate exists, and only if we want a cached revision.
 152  if (!$usesvg) {
 153      $imagefile = $theme->resolve_image_location($image, $component, true);
 154      if (!empty($imagefile) && is_readable($imagefile)) {
 155          $cacheimage = cache_image($image, $imagefile, $candidatelocation);
 156          $pathinfo = pathinfo($imagefile);
 157          // There is no SVG equivalent, we've just successfully cached an image of another format.
 158          if ($pathinfo['extension'] !== 'svg') {
 159              // Serve the file as we would in a normal request.
 160              if (connection_aborted()) {
 161                  die;
 162              }
 163              // Make sure nothing failed.
 164              clearstatcache();
 165              if (file_exists($cacheimage)) {
 166                  send_cached_image($cacheimage, $etag);
 167              }
 168              send_uncached_image($imagefile);
 169              exit;
 170          }
 171      }
 172  }
 173  
 174  // Either SVG was requested or we've cached a SVG version and are ready to serve a regular format.
 175  $imagefile = $theme->resolve_image_location($image, $component, $usesvg);
 176  if (empty($imagefile) or !is_readable($imagefile)) {
 177      if (!file_exists($candidatelocation)) {
 178          @mkdir($candidatelocation, $CFG->directorypermissions, true);
 179      }
 180      // Make note we can not find this file.
 181      $cacheimage = "$candidatelocation/$image.error";
 182      $fp = fopen($cacheimage, 'w');
 183      fclose($fp);
 184      image_not_found();
 185  }
 186  
 187  $cacheimage = cache_image($image, $imagefile, $candidatelocation);
 188  if (connection_aborted()) {
 189      die;
 190  }
 191  // Make sure nothing failed.
 192  clearstatcache();
 193  if (file_exists($cacheimage)) {
 194      send_cached_image($cacheimage, $etag);
 195  }
 196  
 197  send_uncached_image($imagefile);
 198  
 199  
 200  //=================================================================================
 201  //=== utility functions ==
 202  // we are not using filelib because we need to fine tune all header
 203  // parameters to get the best performance.
 204  
 205  function send_cached_image($imagepath, $etag) {
 206      global $CFG;
 207      require("$CFG->dirroot/lib/xsendfilelib.php");
 208  
 209      $lifetime = 60*60*24*60; // 60 days only - the revision may get incremented quite often
 210      $pathinfo = pathinfo($imagepath);
 211      $imagename = $pathinfo['filename'].'.'.$pathinfo['extension'];
 212  
 213      $mimetype = get_contenttype_from_ext($pathinfo['extension']);
 214  
 215      header('Etag: "'.$etag.'"');
 216      header('Content-Disposition: inline; filename="'.$imagename.'"');
 217      header('Last-Modified: '. gmdate('D, d M Y H:i:s', filemtime($imagepath)) .' GMT');
 218      header('Expires: '. gmdate('D, d M Y H:i:s', time() + $lifetime) .' GMT');
 219      header('Pragma: ');
 220      header('Cache-Control: public, max-age='.$lifetime.', no-transform');
 221      header('Accept-Ranges: none');
 222      header('Content-Type: '.$mimetype);
 223      header('Content-Length: '.filesize($imagepath));
 224  
 225      if (xsendfile($imagepath)) {
 226          die;
 227      }
 228  
 229      // no need to gzip already compressed images ;-)
 230  
 231      readfile($imagepath);
 232      die;
 233  }
 234  
 235  function send_uncached_image($imagepath) {
 236      $pathinfo = pathinfo($imagepath);
 237      $imagename = $pathinfo['filename'].'.'.$pathinfo['extension'];
 238  
 239      $mimetype = get_contenttype_from_ext($pathinfo['extension']);
 240  
 241      header('Content-Disposition: inline; filename="'.$imagename.'"');
 242      header('Last-Modified: '. gmdate('D, d M Y H:i:s', time()) .' GMT');
 243      header('Expires: '. gmdate('D, d M Y H:i:s', time() + 15) .' GMT');
 244      header('Pragma: ');
 245      header('Accept-Ranges: none');
 246      header('Content-Type: '.$mimetype);
 247      header('Content-Length: '.filesize($imagepath));
 248  
 249      readfile($imagepath);
 250      die;
 251  }
 252  
 253  function image_not_found() {
 254      header('HTTP/1.0 404 not found');
 255      die('Image was not found, sorry.');
 256  }
 257  
 258  function get_contenttype_from_ext($ext) {
 259      switch ($ext) {
 260          case 'svg':
 261              return 'image/svg+xml';
 262          case 'png':
 263              return 'image/png';
 264          case 'gif':
 265              return 'image/gif';
 266          case 'jpg':
 267          case 'jpeg':
 268              return 'image/jpeg';
 269          case 'ico':
 270              return 'image/vnd.microsoft.icon';
 271      }
 272      return 'document/unknown';
 273  }
 274  
 275  /**
 276   * Caches a given image file.
 277   *
 278   * @param string $image The name of the image that was requested.
 279   * @param string $imagefile The location of the image file we want to cache.
 280   * @param string $candidatelocation The location to cache it in.
 281   * @return string The path to the cached image.
 282   */
 283  function cache_image($image, $imagefile, $candidatelocation) {
 284      global $CFG;
 285      $pathinfo = pathinfo($imagefile);
 286      $cacheimage = "$candidatelocation/$image.".$pathinfo['extension'];
 287  
 288      clearstatcache();
 289      if (!file_exists(dirname($cacheimage))) {
 290          @mkdir(dirname($cacheimage), $CFG->directorypermissions, true);
 291      }
 292  
 293      // Prevent serving of incomplete file from concurrent request,
 294      // the rename() should be more atomic than copy().
 295      ignore_user_abort(true);
 296      if (@copy($imagefile, $cacheimage.'.tmp')) {
 297          rename($cacheimage.'.tmp', $cacheimage);
 298          @chmod($cacheimage, $CFG->filepermissions);
 299          @unlink($cacheimage.'.tmp'); // just in case anything fails
 300      }
 301      return $cacheimage;
 302  }