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   1  <?php
   2  /**
   3   * PHP script to stream out an image thumbnail.
   4   *
   5   * This program is free software; you can redistribute it and/or modify
   6   * it under the terms of the GNU General Public License as published by
   7   * the Free Software Foundation; either version 2 of the License, or
   8   * (at your option) any later version.
   9   *
  10   * This program is distributed in the hope that it will be useful,
  11   * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13   * GNU General Public License for more details.
  14   *
  15   * You should have received a copy of the GNU General Public License along
  16   * with this program; if not, write to the Free Software Foundation, Inc.,
  17   * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18   * http://www.gnu.org/copyleft/gpl.html
  19   *
  20   * @file
  21   * @ingroup Media
  22   */
  23  
  24  define( 'MW_NO_OUTPUT_COMPRESSION', 1 );
  25  require  __DIR__ . '/includes/WebStart.php';
  26  
  27  // Don't use fancy MIME detection, just check the file extension for jpg/gif/png
  28  $wgTrivialMimeDetection = true;
  29  
  30  if ( defined( 'THUMB_HANDLER' ) ) {
  31      // Called from thumb_handler.php via 404; extract params from the URI...
  32      wfThumbHandle404();
  33  } else {
  34      // Called directly, use $_GET params
  35      wfThumbHandleRequest();
  36  }
  37  
  38  wfLogProfilingData();
  39  // Commit and close up!
  40  $factory = wfGetLBFactory();
  41  $factory->commitMasterChanges();
  42  $factory->shutdown();
  43  
  44  //--------------------------------------------------------------------------
  45  
  46  /**
  47   * Handle a thumbnail request via query parameters
  48   *
  49   * @return void
  50   */
  51  function wfThumbHandleRequest() {
  52      $params = get_magic_quotes_gpc()
  53          ? array_map( 'stripslashes', $_GET )
  54          : $_GET;
  55  
  56      wfStreamThumb( $params ); // stream the thumbnail
  57  }
  58  
  59  /**
  60   * Handle a thumbnail request via thumbnail file URL
  61   *
  62   * @return void
  63   */
  64  function wfThumbHandle404() {
  65      global $wgArticlePath;
  66  
  67      # Set action base paths so that WebRequest::getPathInfo()
  68      # recognizes the "X" as the 'title' in ../thumb_handler.php/X urls.
  69      # Note: If Custom per-extension repo paths are set, this may break.
  70      $repo = RepoGroup::singleton()->getLocalRepo();
  71      $oldArticlePath = $wgArticlePath;
  72      $wgArticlePath = $repo->getZoneUrl( 'thumb' ) . '/$1';
  73  
  74      $matches = WebRequest::getPathInfo();
  75  
  76      $wgArticlePath = $oldArticlePath;
  77  
  78      if ( !isset( $matches['title'] ) ) {
  79          wfThumbError( 404, 'Could not determine the name of the requested thumbnail.' );
  80          return;
  81      }
  82  
  83      $params = wfExtractThumbRequestInfo( $matches['title'] ); // basic wiki URL param extracting
  84      if ( $params == null ) {
  85          wfThumbError( 400, 'The specified thumbnail parameters are not recognized.' );
  86          return;
  87      }
  88  
  89      wfStreamThumb( $params ); // stream the thumbnail
  90  }
  91  
  92  /**
  93   * Stream a thumbnail specified by parameters
  94   *
  95   * @param array $params List of thumbnailing parameters. In addition to parameters
  96   *  passed to the MediaHandler, this may also includes the keys:
  97   *   f (for filename), archived (if archived file), temp (if temp file),
  98   *   w (alias for width), p (alias for page), r (ignored; historical),
  99   *   rel404 (path for render on 404 to verify hash path correct),
 100   *   thumbName (thumbnail name to potentially extract more parameters from
 101   *   e.g. 'lossy-page1-120px-Foo.tiff' would add page, lossy and width
 102   *   to the parameters)
 103   * @return void
 104   */
 105  function wfStreamThumb( array $params ) {
 106      global $wgVaryOnXFP;
 107  
 108      $section = new ProfileSection( __METHOD__ );
 109  
 110      $headers = array(); // HTTP headers to send
 111  
 112      $fileName = isset( $params['f'] ) ? $params['f'] : '';
 113  
 114      // Backwards compatibility parameters
 115      if ( isset( $params['w'] ) ) {
 116          $params['width'] = $params['w'];
 117          unset( $params['w'] );
 118      }
 119      if ( isset( $params['width'] ) && substr( $params['width'], -2 ) == 'px' ) {
 120          // strip the px (pixel) suffix, if found
 121          $params['width'] = substr( $params['width'], 0, -2 );
 122      }
 123      if ( isset( $params['p'] ) ) {
 124          $params['page'] = $params['p'];
 125      }
 126  
 127      // Is this a thumb of an archived file?
 128      $isOld = ( isset( $params['archived'] ) && $params['archived'] );
 129      unset( $params['archived'] ); // handlers don't care
 130  
 131      // Is this a thumb of a temp file?
 132      $isTemp = ( isset( $params['temp'] ) && $params['temp'] );
 133      unset( $params['temp'] ); // handlers don't care
 134  
 135      // Some basic input validation
 136      $fileName = strtr( $fileName, '\\/', '__' );
 137  
 138      // Actually fetch the image. Method depends on whether it is archived or not.
 139      if ( $isTemp ) {
 140          $repo = RepoGroup::singleton()->getLocalRepo()->getTempRepo();
 141          $img = new UnregisteredLocalFile( null, $repo,
 142              # Temp files are hashed based on the name without the timestamp.
 143              # The thumbnails will be hashed based on the entire name however.
 144              # @todo fix this convention to actually be reasonable.
 145              $repo->getZonePath( 'public' ) . '/' . $repo->getTempHashPath( $fileName ) . $fileName
 146          );
 147      } elseif ( $isOld ) {
 148          // Format is <timestamp>!<name>
 149          $bits = explode( '!', $fileName, 2 );
 150          if ( count( $bits ) != 2 ) {
 151              wfThumbError( 404, wfMessage( 'badtitletext' )->text() );
 152              return;
 153          }
 154          $title = Title::makeTitleSafe( NS_FILE, $bits[1] );
 155          if ( !$title ) {
 156              wfThumbError( 404, wfMessage( 'badtitletext' )->text() );
 157              return;
 158          }
 159          $img = RepoGroup::singleton()->getLocalRepo()->newFromArchiveName( $title, $fileName );
 160      } else {
 161          $img = wfLocalFile( $fileName );
 162      }
 163  
 164      // Check the source file title
 165      if ( !$img ) {
 166          wfThumbError( 404, wfMessage( 'badtitletext' )->text() );
 167          return;
 168      }
 169  
 170      // Check permissions if there are read restrictions
 171      $varyHeader = array();
 172      if ( !in_array( 'read', User::getGroupPermissions( array( '*' ) ), true ) ) {
 173          if ( !$img->getTitle() || !$img->getTitle()->userCan( 'read' ) ) {
 174              wfThumbError( 403, 'Access denied. You do not have permission to access ' .
 175                  'the source file.' );
 176              return;
 177          }
 178          $headers[] = 'Cache-Control: private';
 179          $varyHeader[] = 'Cookie';
 180      }
 181  
 182      // Check if the file is hidden
 183      if ( $img->isDeleted( File::DELETED_FILE ) ) {
 184          wfThumbError( 404, "The source file '$fileName' does not exist." );
 185          return;
 186      }
 187  
 188      // Do rendering parameters extraction from thumbnail name.
 189      if ( isset( $params['thumbName'] ) ) {
 190          $params = wfExtractThumbParams( $img, $params );
 191      }
 192      if ( $params == null ) {
 193          wfThumbError( 400, 'The specified thumbnail parameters are not recognized.' );
 194          return;
 195      }
 196  
 197      // Check the source file storage path
 198      if ( !$img->exists() ) {
 199          $redirectedLocation = false;
 200          if ( !$isTemp ) {
 201              // Check for file redirect
 202              // Since redirects are associated with pages, not versions of files,
 203              // we look for the most current version to see if its a redirect.
 204              $possRedirFile = RepoGroup::singleton()->getLocalRepo()->findFile( $img->getName() );
 205              if ( $possRedirFile && !is_null( $possRedirFile->getRedirected() ) ) {
 206                  $redirTarget = $possRedirFile->getName();
 207                  $targetFile = wfLocalFile( Title::makeTitleSafe( NS_FILE, $redirTarget ) );
 208                  if ( $targetFile->exists() ) {
 209                      $newThumbName = $targetFile->thumbName( $params );
 210                      if ( $isOld ) {
 211                          $newThumbUrl = $targetFile->getArchiveThumbUrl(
 212                              $bits[0] . '!' . $targetFile->getName(), $newThumbName );
 213                      } else {
 214                          $newThumbUrl = $targetFile->getThumbUrl( $newThumbName );
 215                      }
 216                      $redirectedLocation = wfExpandUrl( $newThumbUrl, PROTO_CURRENT );
 217                  }
 218              }
 219          }
 220  
 221          if ( $redirectedLocation ) {
 222              // File has been moved. Give redirect.
 223              $response = RequestContext::getMain()->getRequest()->response();
 224              $response->header( "HTTP/1.1 302 " . HttpStatus::getMessage( 302 ) );
 225              $response->header( 'Location: ' . $redirectedLocation );
 226              $response->header( 'Expires: ' .
 227                  gmdate( 'D, d M Y H:i:s', time() + 12 * 3600 ) . ' GMT' );
 228              if ( $wgVaryOnXFP ) {
 229                  $varyHeader[] = 'X-Forwarded-Proto';
 230              }
 231              if ( count( $varyHeader ) ) {
 232                  $response->header( 'Vary: ' . implode( ', ', $varyHeader ) );
 233              }
 234              return;
 235          }
 236  
 237          // If its not a redirect that has a target as a local file, give 404.
 238          wfThumbError( 404, "The source file '$fileName' does not exist." );
 239          return;
 240      } elseif ( $img->getPath() === false ) {
 241          wfThumbError( 500, "The source file '$fileName' is not locally accessible." );
 242          return;
 243      }
 244  
 245      // Check IMS against the source file
 246      // This means that clients can keep a cached copy even after it has been deleted on the server
 247      if ( !empty( $_SERVER['HTTP_IF_MODIFIED_SINCE'] ) ) {
 248          // Fix IE brokenness
 249          $imsString = preg_replace( '/;.*$/', '', $_SERVER["HTTP_IF_MODIFIED_SINCE"] );
 250          // Calculate time
 251          wfSuppressWarnings();
 252          $imsUnix = strtotime( $imsString );
 253          wfRestoreWarnings();
 254          if ( wfTimestamp( TS_UNIX, $img->getTimestamp() ) <= $imsUnix ) {
 255              header( 'HTTP/1.1 304 Not Modified' );
 256              return;
 257          }
 258      }
 259  
 260      $rel404 = isset( $params['rel404'] ) ? $params['rel404'] : null;
 261      unset( $params['r'] ); // ignore 'r' because we unconditionally pass File::RENDER
 262      unset( $params['f'] ); // We're done with 'f' parameter.
 263      unset( $params['rel404'] ); // moved to $rel404
 264  
 265      // Get the normalized thumbnail name from the parameters...
 266      try {
 267          $thumbName = $img->thumbName( $params );
 268          if ( !strlen( $thumbName ) ) { // invalid params?
 269              wfThumbError( 400, 'The specified thumbnail parameters are not valid.' );
 270              return;
 271          }
 272          $thumbName2 = $img->thumbName( $params, File::THUMB_FULL_NAME ); // b/c; "long" style
 273      } catch ( MWException $e ) {
 274          wfThumbError( 500, $e->getHTML() );
 275          return;
 276      }
 277  
 278      // For 404 handled thumbnails, we only use the the base name of the URI
 279      // for the thumb params and the parent directory for the source file name.
 280      // Check that the zone relative path matches up so squid caches won't pick
 281      // up thumbs that would not be purged on source file deletion (bug 34231).
 282      if ( $rel404 !== null ) { // thumbnail was handled via 404
 283          if ( rawurldecode( $rel404 ) === $img->getThumbRel( $thumbName ) ) {
 284              // Request for the canonical thumbnail name
 285          } elseif ( rawurldecode( $rel404 ) === $img->getThumbRel( $thumbName2 ) ) {
 286              // Request for the "long" thumbnail name; redirect to canonical name
 287              $response = RequestContext::getMain()->getRequest()->response();
 288              $response->header( "HTTP/1.1 301 " . HttpStatus::getMessage( 301 ) );
 289              $response->header( 'Location: ' .
 290                  wfExpandUrl( $img->getThumbUrl( $thumbName ), PROTO_CURRENT ) );
 291              $response->header( 'Expires: ' .
 292                  gmdate( 'D, d M Y H:i:s', time() + 7 * 86400 ) . ' GMT' );
 293              if ( $wgVaryOnXFP ) {
 294                  $varyHeader[] = 'X-Forwarded-Proto';
 295              }
 296              if ( count( $varyHeader ) ) {
 297                  $response->header( 'Vary: ' . implode( ', ', $varyHeader ) );
 298              }
 299              return;
 300          } else {
 301              wfThumbError( 404, "The given path of the specified thumbnail is incorrect;
 302                  expected '" . $img->getThumbRel( $thumbName ) . "' but got '" .
 303                  rawurldecode( $rel404 ) . "'." );
 304              return;
 305          }
 306      }
 307  
 308      $dispositionType = isset( $params['download'] ) ? 'attachment' : 'inline';
 309  
 310      // Suggest a good name for users downloading this thumbnail
 311      $headers[] = "Content-Disposition: {$img->getThumbDisposition( $thumbName, $dispositionType )}";
 312  
 313      if ( count( $varyHeader ) ) {
 314          $headers[] = 'Vary: ' . implode( ', ', $varyHeader );
 315      }
 316  
 317      // Stream the file if it exists already...
 318      $thumbPath = $img->getThumbPath( $thumbName );
 319      if ( $img->getRepo()->fileExists( $thumbPath ) ) {
 320          $img->getRepo()->streamFile( $thumbPath, $headers );
 321          return;
 322      }
 323  
 324      $user = RequestContext::getMain()->getUser();
 325      if ( !wfThumbIsStandard( $img, $params ) && $user->pingLimiter( 'renderfile-nonstandard' ) ) {
 326          wfThumbError( 500, wfMessage( 'actionthrottledtext' ) );
 327          return;
 328      } elseif ( $user->pingLimiter( 'renderfile' ) ) {
 329          wfThumbError( 500, wfMessage( 'actionthrottledtext' ) );
 330          return;
 331      }
 332  
 333      // Actually generate a new thumbnail
 334      list( $thumb, $errorMsg ) = wfGenerateThumbnail( $img, $params, $thumbName, $thumbPath );
 335  
 336      // Check for thumbnail generation errors...
 337      $msg = wfMessage( 'thumbnail_error' );
 338      if ( !$thumb ) {
 339          $errorMsg = $errorMsg ?: $msg->rawParams( 'File::transform() returned false' )->escaped();
 340      } elseif ( $thumb->isError() ) {
 341          $errorMsg = $thumb->getHtmlMsg();
 342      } elseif ( !$thumb->hasFile() ) {
 343          $errorMsg = $msg->rawParams( 'No path supplied in thumbnail object' )->escaped();
 344      } elseif ( $thumb->fileIsSource() ) {
 345          $errorMsg = $msg->
 346              rawParams( 'Image was not scaled, is the requested width bigger than the source?' )->escaped();
 347      }
 348  
 349      if ( $errorMsg !== false ) {
 350          wfThumbError( 500, $errorMsg );
 351      } else {
 352          // Stream the file if there were no errors
 353          $thumb->streamFile( $headers );
 354      }
 355  }
 356  
 357  /**
 358   * Actually try to generate a new thumbnail
 359   *
 360   * @param File $file
 361   * @param array $params
 362   * @param string $thumbName
 363   * @param string $thumbPath
 364   * @return array (MediaTransformOutput|bool, string|bool error message HTML)
 365   */
 366  function wfGenerateThumbnail( File $file, array $params, $thumbName, $thumbPath ) {
 367      global $wgMemc, $wgAttemptFailureEpoch;
 368  
 369      $key = wfMemcKey( 'attempt-failures', $wgAttemptFailureEpoch,
 370          $file->getRepo()->getName(), $file->getSha1(), md5( $thumbName ) );
 371  
 372      // Check if this file keeps failing to render
 373      if ( $wgMemc->get( $key ) >= 4 ) {
 374          return array( false, wfMessage( 'thumbnail_image-failure-limit', 4 ) );
 375      }
 376  
 377      $done = false;
 378      // Record failures on PHP fatals in addition to caching exceptions
 379      register_shutdown_function( function () use ( &$done, $key ) {
 380          if ( !$done ) { // transform() gave a fatal
 381              global $wgMemc;
 382              // Randomize TTL to reduce stampedes
 383              $wgMemc->incrWithInit( $key, 3600 + mt_rand( 0, 300 ) );
 384          }
 385      } );
 386  
 387      $thumb = false;
 388      $errorHtml = false;
 389  
 390      // guard thumbnail rendering with PoolCounter to avoid stampedes
 391      // expensive files use a separate PoolCounter config so it is possible
 392      // to set up a global limit on them
 393      if ( $file->isExpensiveToThumbnail() ) {
 394          $poolCounterType = 'FileRenderExpensive';
 395      } else {
 396          $poolCounterType = 'FileRender';
 397      }
 398  
 399      // Thumbnail isn't already there, so create the new thumbnail...
 400      try {
 401          $work = new PoolCounterWorkViaCallback( $poolCounterType, sha1( $file->getName() ),
 402              array(
 403                  'doWork' => function () use ( $file, $params ) {
 404                      return $file->transform( $params, File::RENDER_NOW );
 405                  },
 406                  'getCachedWork' => function () use ( $file, $params, $thumbPath ) {
 407                      // If the worker that finished made this thumbnail then use it.
 408                      // Otherwise, it probably made a different thumbnail for this file.
 409                      return $file->getRepo()->fileExists( $thumbPath )
 410                          ? $file->transform( $params, File::RENDER_NOW )
 411                          : false; // retry once more in exclusive mode
 412                  },
 413                  'fallback' => function () {
 414                      return wfMessage( 'generic-pool-error' )->parse();
 415                  },
 416                  'error' => function ( $status ) {
 417                      return $status->getHTML();
 418                  }
 419              )
 420          );
 421          $result = $work->execute();
 422          if ( $result instanceof MediaTransformOutput ) {
 423              $thumb = $result;
 424          } elseif ( is_string( $result ) ) { // error
 425              $errorHtml = $result;
 426          }
 427      } catch ( Exception $e ) {
 428          // Tried to select a page on a non-paged file?
 429      }
 430  
 431      $done = true; // no PHP fatal occured
 432  
 433      if ( !$thumb || $thumb->isError() ) {
 434          // Randomize TTL to reduce stampedes
 435          $wgMemc->incrWithInit( $key, 3600 + mt_rand( 0, 300 ) );
 436      }
 437  
 438      return array( $thumb, $errorHtml );
 439  }
 440  
 441  /**
 442   * Returns true if this thumbnail is one that MediaWiki generates
 443   * links to on file description pages and possibly parser output.
 444   *
 445   * $params is considered non-standard if they involve a non-standard
 446   * width or any non-default parameters aside from width and page number.
 447   * The number of possible files with standard parameters is far less than
 448   * that of all combinations; rate-limiting for them can thus be more generious.
 449   *
 450   * @param File $file
 451   * @param array $params
 452   * @return bool
 453   */
 454  function wfThumbIsStandard( File $file, array $params ) {
 455      global $wgThumbLimits, $wgImageLimits;
 456  
 457      $handler = $file->getHandler();
 458      if ( !$handler || !isset( $params['width'] ) ) {
 459          return false;
 460      }
 461  
 462      $basicParams = array();
 463      if ( isset( $params['page'] ) ) {
 464          $basicParams['page'] = $params['page'];
 465      }
 466  
 467      // Check if the width matches one of $wgThumbLimits
 468      if ( in_array( $params['width'], $wgThumbLimits ) ) {
 469          $normalParams = $basicParams + array( 'width' => $params['width'] );
 470          // Append any default values to the map (e.g. "lossy", "lossless", ...)
 471          $handler->normaliseParams( $file, $normalParams );
 472      } else {
 473          // If not, then check if the width matchs one of $wgImageLimits
 474          $match = false;
 475          foreach ( $wgImageLimits as $pair ) {
 476              $normalParams = $basicParams + array( 'width' => $pair[0], 'height' => $pair[1] );
 477              // Decide whether the thumbnail should be scaled on width or height.
 478              // Also append any default values to the map (e.g. "lossy", "lossless", ...)
 479              $handler->normaliseParams( $file, $normalParams );
 480              // Check if this standard thumbnail size maps to the given width
 481              if ( $normalParams['width'] == $params['width'] ) {
 482                  $match = true;
 483                  break;
 484              }
 485          }
 486          if ( !$match ) {
 487              return false; // not standard for description pages
 488          }
 489      }
 490  
 491      // Check that the given values for non-page, non-width, params are just defaults
 492      foreach ( $params as $key => $value ) {
 493          if ( !isset( $normalParams[$key] ) || $normalParams[$key] != $value ) {
 494              return false;
 495          }
 496      }
 497  
 498      return true;
 499  }
 500  
 501  /**
 502   * Convert pathinfo type parameter, into normal request parameters
 503   *
 504   * So for example, if the request was redirected from
 505   * /w/images/thumb/a/ab/Foo.png/120px-Foo.png. The $thumbRel parameter
 506   * of this function would be set to "a/ab/Foo.png/120px-Foo.png".
 507   * This method is responsible for turning that into an array
 508   * with the folowing keys:
 509   *  * f => the filename (Foo.png)
 510   *  * rel404 => the whole thing (a/ab/Foo.png/120px-Foo.png)
 511   *  * archived => 1 (If the request is for an archived thumb)
 512   *  * temp => 1 (If the file is in the "temporary" zone)
 513   *  * thumbName => the thumbnail name, including parameters (120px-Foo.png)
 514   *
 515   * Transform specific parameters are set later via wfExtractThumbParams().
 516   *
 517   * @param string $thumbRel Thumbnail path relative to the thumb zone
 518   * @return array|null Associative params array or null
 519   */
 520  function wfExtractThumbRequestInfo( $thumbRel ) {
 521      $repo = RepoGroup::singleton()->getLocalRepo();
 522  
 523      $hashDirReg = $subdirReg = '';
 524      $hashLevels = $repo->getHashLevels();
 525      for ( $i = 0; $i < $hashLevels; $i++ ) {
 526          $subdirReg .= '[0-9a-f]';
 527          $hashDirReg .= "$subdirReg/";
 528      }
 529  
 530      // Check if this is a thumbnail of an original in the local file repo
 531      if ( preg_match( "!^((archive/)?$hashDirReg([^/]*)/([^/]*))$!", $thumbRel, $m ) ) {
 532          list( /*all*/, $rel, $archOrTemp, $filename, $thumbname ) = $m;
 533      // Check if this is a thumbnail of an temp file in the local file repo
 534      } elseif ( preg_match( "!^(temp/)($hashDirReg([^/]*)/([^/]*))$!", $thumbRel, $m ) ) {
 535          list( /*all*/, $archOrTemp, $rel, $filename, $thumbname ) = $m;
 536      } else {
 537          return null; // not a valid looking thumbnail request
 538      }
 539  
 540      $params = array( 'f' => $filename, 'rel404' => $rel );
 541      if ( $archOrTemp === 'archive/' ) {
 542          $params['archived'] = 1;
 543      } elseif ( $archOrTemp === 'temp/' ) {
 544          $params['temp'] = 1;
 545      }
 546  
 547      $params['thumbName'] = $thumbname;
 548      return $params;
 549  }
 550  
 551  /**
 552   * Convert a thumbnail name (122px-foo.png) to parameters, using
 553   * file handler.
 554   *
 555   * @param File $file File object for file in question
 556   * @param array $params Array of parameters so far
 557   * @return array Parameters array with more parameters
 558   */
 559  function wfExtractThumbParams( $file, $params ) {
 560      if ( !isset( $params['thumbName'] ) ) {
 561          throw new MWException( "No thumbnail name passed to wfExtractThumbParams" );
 562      }
 563  
 564      $thumbname = $params['thumbName'];
 565      unset( $params['thumbName'] );
 566  
 567      // Do the hook first for older extensions that rely on it.
 568      if ( !wfRunHooks( 'ExtractThumbParameters', array( $thumbname, &$params ) ) ) {
 569          // Check hooks if parameters can be extracted
 570          // Hooks return false if they manage to *resolve* the parameters
 571          // This hook should be considered deprecated
 572          wfDeprecated( 'ExtractThumbParameters', '1.22' );
 573          return $params; // valid thumbnail URL (via extension or config)
 574      }
 575  
 576      // FIXME: Files in the temp zone don't set a MIME type, which means
 577      // they don't have a handler. Which means we can't parse the param
 578      // string. However, not a big issue as what good is a param string
 579      // if you have no handler to make use of the param string and
 580      // actually generate the thumbnail.
 581      $handler = $file->getHandler();
 582  
 583      // Based on UploadStash::parseKey
 584      $fileNamePos = strrpos( $thumbname, $params['f'] );
 585      if ( $fileNamePos === false ) {
 586          // Maybe using a short filename? (see FileRepo::nameForThumb)
 587          $fileNamePos = strrpos( $thumbname, 'thumbnail' );
 588      }
 589  
 590      if ( $handler && $fileNamePos !== false ) {
 591          $paramString = substr( $thumbname, 0, $fileNamePos - 1 );
 592          $extraParams = $handler->parseParamString( $paramString );
 593          if ( $extraParams !== false ) {
 594              return $params + $extraParams;
 595          }
 596      }
 597  
 598      // As a last ditch fallback, use the traditional common parameters
 599      if ( preg_match( '!^(page(\d*)-)*(\d*)px-[^/]*$!', $thumbname, $matches ) ) {
 600          list( /* all */, $pagefull, $pagenum, $size ) = $matches;
 601          $params['width'] = $size;
 602          if ( $pagenum ) {
 603              $params['page'] = $pagenum;
 604          }
 605          return $params; // valid thumbnail URL
 606      }
 607      return null;
 608  }
 609  
 610  /**
 611   * Output a thumbnail generation error message
 612   *
 613   * @param int $status
 614   * @param string $msg
 615   * @return void
 616   */
 617  function wfThumbError( $status, $msg ) {
 618      global $wgShowHostnames;
 619  
 620      header( 'Cache-Control: no-cache' );
 621      header( 'Content-Type: text/html; charset=utf-8' );
 622      if ( $status == 404 ) {
 623          header( 'HTTP/1.1 404 Not found' );
 624      } elseif ( $status == 403 ) {
 625          header( 'HTTP/1.1 403 Forbidden' );
 626          header( 'Vary: Cookie' );
 627      } else {
 628          header( 'HTTP/1.1 500 Internal server error' );
 629      }
 630      if ( $wgShowHostnames ) {
 631          header( 'X-MW-Thumbnail-Renderer: ' . wfHostname() );
 632          $url = htmlspecialchars( isset( $_SERVER['REQUEST_URI'] ) ? $_SERVER['REQUEST_URI'] : '' );
 633          $hostname = htmlspecialchars( wfHostname() );
 634          $debug = "<!-- $url -->\n<!-- $hostname -->\n";
 635      } else {
 636          $debug = '';
 637      }
 638      echo <<<EOT
 639  <html><head><title>Error generating thumbnail</title></head>
 640  <body>
 641  <h1>Error generating thumbnail</h1>
 642  <p>
 643  $msg
 644  </p>
 645  $debug
 646  </body>
 647  </html>
 648  
 649  EOT;
 650  }