thumb.php

   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 }