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
  40 //--------------------------------------------------------------------------
  41
  42 /**
  43  * Handle a thumbnail request via query parameters
  44  *
  45  * @return void
  46  */
  47 function wfThumbHandleRequest() {
  48         $params = get_magic_quotes_gpc()
  49                 ? array_map( 'stripslashes', $_GET )
  50                 : $_GET;
  51
  52         wfStreamThumb( $params ); // stream the thumbnail
  53 }
  54
  55 /**
  56  * Handle a thumbnail request via thumbnail file URL
  57  *
  58  * @return void
  59  */
  60 function wfThumbHandle404() {
  61         global $wgArticlePath;
  62
  63         # Set action base paths so that WebRequest::getPathInfo()
  64         # recognizes the "X" as the 'title' in ../thumb_handler.php/X urls.
  65         # Note: If Custom per-extension repo paths are set, this may break.
  66         $repo = RepoGroup::singleton()->getLocalRepo();
  67         $oldArticlePath = $wgArticlePath;
  68         $wgArticlePath = $repo->getZoneUrl( 'thumb' ) . '/$1';
  69
  70         $matches = WebRequest::getPathInfo();
  71
  72         $wgArticlePath = $oldArticlePath;
  73
  74         if ( !isset( $matches['title'] ) ) {
  75                 wfThumbError( 404, 'Could not determine the name of the requested thumbnail.' );
  76                 return;
  77         }
  78
  79         $params = wfExtractThumbRequestInfo( $matches['title'] ); // basic wiki URL param extracting
  80         if ( $params == null ) {
  81                 wfThumbError( 400, 'The specified thumbnail parameters are not recognized.' );
  82                 return;
  83         }
  84
  85         wfStreamThumb( $params ); // stream the thumbnail
  86 }
  87
  88 /**
  89  * Stream a thumbnail specified by parameters
  90  *
  91  * @param $params Array List of thumbnailing parameters. In addition to parameters
  92  *  passed to the MediaHandler, this may also includes the keys:
  93  *   f (for filename), archived (if archived file), temp (if temp file),
  94  *   w (alias for width), p (alias for page), r (ignored; historical),
  95  *   rel404 (path for render on 404 to verify hash path correct),
  96  *   thumbName (thumbnail name to potentially extract more parameters from
  97  *   e.g. 'lossy-page1-120px-Foo.tiff' would add page, lossy and width
  98  *   to the parameters)
  99  * @return void
 100  */
 101 function wfStreamThumb( array $params ) {
 102         global $wgVaryOnXFP;
 103
 104         $section = new ProfileSection( __METHOD__ );
 105
 106         $headers = array(); // HTTP headers to send
 107
 108         $fileName = isset( $params['f'] ) ? $params['f'] : '';
 109
 110         // Backwards compatibility parameters
 111         if ( isset( $params['w'] ) ) {
 112                 $params['width'] = $params['w'];
 113                 unset( $params['w'] );
 114         }
 115         if ( isset( $params['p'] ) ) {
 116                 $params['page'] = $params['p'];
 117         }
 118
 119         // Is this a thumb of an archived file?
 120         $isOld = ( isset( $params['archived'] ) && $params['archived'] );
 121         unset( $params['archived'] ); // handlers don't care
 122
 123         // Is this a thumb of a temp file?
 124         $isTemp = ( isset( $params['temp'] ) && $params['temp'] );
 125         unset( $params['temp'] ); // handlers don't care
 126
 127         // Some basic input validation
 128         $fileName = strtr( $fileName, '\\/', '__' );
 129
 130         // Actually fetch the image. Method depends on whether it is archived or not.
 131         if ( $isTemp ) {
 132                 $repo = RepoGroup::singleton()->getLocalRepo()->getTempRepo();
 133                 $img = new UnregisteredLocalFile( null, $repo,
 134                         # Temp files are hashed based on the name without the timestamp.
 135                         # The thumbnails will be hashed based on the entire name however.
 136                         # @todo fix this convention to actually be reasonable.
 137                         $repo->getZonePath( 'public' ) . '/' . $repo->getTempHashPath( $fileName ) . $fileName
 138                 );
 139         } elseif ( $isOld ) {
 140                 // Format is <timestamp>!<name>
 141                 $bits = explode( '!', $fileName, 2 );
 142                 if ( count( $bits ) != 2 ) {
 143                         wfThumbError( 404, wfMessage( 'badtitletext' )->text() );
 144                         return;
 145                 }
 146                 $title = Title::makeTitleSafe( NS_FILE, $bits[1] );
 147                 if ( !$title ) {
 148                         wfThumbError( 404, wfMessage( 'badtitletext' )->text() );
 149                         return;
 150                 }
 151                 $img = RepoGroup::singleton()->getLocalRepo()->newFromArchiveName( $title, $fileName );
 152         } else {
 153                 $img = wfLocalFile( $fileName );
 154         }
 155
 156         // Check the source file title
 157         if ( !$img ) {
 158                 wfThumbError( 404, wfMessage( 'badtitletext' )->text() );
 159                 return;
 160         }
 161
 162         // Check permissions if there are read restrictions
 163         $varyHeader = array();
 164         if ( !in_array( 'read', User::getGroupPermissions( array( '*' ) ), true ) ) {
 165                 if ( !$img->getTitle() || !$img->getTitle()->userCan( 'read' ) ) {
 166                         wfThumbError( 403, 'Access denied. You do not have permission to access ' .
 167                                 'the source file.' );
 168                         return;
 169                 }
 170                 $headers[] = 'Cache-Control: private';
 171                 $varyHeader[] = 'Cookie';
 172         }
 173
 174         // Do rendering parameters extraction from thumbnail name.
 175         if ( isset( $params['thumbName'] ) ) {
 176                 $params = wfExtractThumbParams( $img, $params );
 177         }
 178         if ( $params == null ) {
 179                 wfThumbError( 400, 'The specified thumbnail parameters are not recognized.' );
 180                 return;
 181         }
 182
 183
 184         // Check the source file storage path
 185         if ( !$img->exists() ) {
 186                 $redirectedLocation = false;
 187                 if ( !$isTemp ) {
 188                         // Check for file redirect
 189                         // Since redirects are associated with pages, not versions of files,
 190                         // we look for the most current version to see if its a redirect.
 191                         $possRedirFile = RepoGroup::singleton()->getLocalRepo()->findFile( $img->getName() );
 192                         if ( $possRedirFile && !is_null( $possRedirFile->getRedirected() ) ) {
 193                                 $redirTarget = $possRedirFile->getName();
 194                                 $targetFile = wfLocalFile( Title::makeTitleSafe( NS_FILE, $redirTarget ) );
 195                                 if ( $targetFile->exists() ) {
 196                                         $newThumbName = $targetFile->thumbName( $params );
 197                                         if ( $isOld ) {
 198                                                 $newThumbUrl = $targetFile->getArchiveThumbUrl(
 199                                                         $bits[0] . '!' . $targetFile->getName(), $newThumbName );
 200                                         } else {
 201                                                 $newThumbUrl = $targetFile->getThumbUrl( $newThumbName );
 202                                         }
 203                                         $redirectedLocation = wfExpandUrl( $newThumbUrl, PROTO_CURRENT );
 204                                 }
 205                         }
 206                 }
 207
 208                 if ( $redirectedLocation ) {
 209                         // File has been moved. Give redirect.
 210                         $response = RequestContext::getMain()->getRequest()->response();
 211                         $response->header( "HTTP/1.1 302 " . HttpStatus::getMessage( 302 ) );
 212                         $response->header( 'Location: ' . $redirectedLocation );
 213                         $response->header( 'Expires: ' .
 214                                 gmdate( 'D, d M Y H:i:s', time() + 12 * 3600 ) . ' GMT' );
 215                         if ( $wgVaryOnXFP ) {
 216                                 $varyHeader[] = 'X-Forwarded-Proto';
 217                         }
 218                         if ( count( $varyHeader ) ) {
 219                                 $response->header( 'Vary: ' . implode( ', ', $varyHeader ) );
 220                         }
 221                         return;
 222                 }
 223
 224                 // If its not a redirect that has a target as a local file, give 404.
 225                 wfThumbError( 404, "The source file '$fileName' does not exist." );
 226                 return;
 227         } elseif ( $img->getPath() === false ) {
 228                 wfThumbError( 500, "The source file '$fileName' is not locally accessible." );
 229                 return;
 230         }
 231
 232         // Check IMS against the source file
 233         // This means that clients can keep a cached copy even after it has been deleted on the server
 234         if ( !empty( $_SERVER['HTTP_IF_MODIFIED_SINCE'] ) ) {
 235                 // Fix IE brokenness
 236                 $imsString = preg_replace( '/;.*$/', '', $_SERVER["HTTP_IF_MODIFIED_SINCE"] );
 237                 // Calculate time
 238                 wfSuppressWarnings();
 239                 $imsUnix = strtotime( $imsString );
 240                 wfRestoreWarnings();
 241                 if ( wfTimestamp( TS_UNIX, $img->getTimestamp() ) <= $imsUnix ) {
 242                         header( 'HTTP/1.1 304 Not Modified' );
 243                         return;
 244                 }
 245         }
 246
 247         unset( $params['r'] ); // ignore 'r' because we unconditionally pass File::RENDER
 248         unset( $params['f'] ); // We're done with 'f' parameter.
 249
 250
 251         // Get the normalized thumbnail name from the parameters...
 252         try {
 253                 $thumbName = $img->thumbName( $params );
 254                 if ( !strlen( $thumbName ) ) { // invalid params?
 255                         wfThumbError( 400, 'The specified thumbnail parameters are not valid.' );
 256                         return;
 257                 }
 258                 $thumbName2 = $img->thumbName( $params, File::THUMB_FULL_NAME ); // b/c; "long" style
 259         } catch ( MWException $e ) {
 260                 wfThumbError( 500, $e->getHTML() );
 261                 return;
 262         }
 263
 264         // For 404 handled thumbnails, we only use the the base name of the URI
 265         // for the thumb params and the parent directory for the source file name.
 266         // Check that the zone relative path matches up so squid caches won't pick
 267         // up thumbs that would not be purged on source file deletion (bug 34231).
 268         if ( isset( $params['rel404'] ) ) { // thumbnail was handled via 404
 269                 if ( rawurldecode( $params['rel404'] ) === $img->getThumbRel( $thumbName ) ) {
 270                         // Request for the canonical thumbnail name
 271                 } elseif ( rawurldecode( $params['rel404'] ) === $img->getThumbRel( $thumbName2 ) ) {
 272                         // Request for the "long" thumbnail name; redirect to canonical name
 273                         $response = RequestContext::getMain()->getRequest()->response();
 274                         $response->header( "HTTP/1.1 301 " . HttpStatus::getMessage( 301 ) );
 275                         $response->header( 'Location: ' .
 276                                 wfExpandUrl( $img->getThumbUrl( $thumbName ), PROTO_CURRENT ) );
 277                         $response->header( 'Expires: ' .
 278                                 gmdate( 'D, d M Y H:i:s', time() + 7 * 86400 ) . ' GMT' );
 279                         if ( $wgVaryOnXFP ) {
 280                                 $varyHeader[] = 'X-Forwarded-Proto';
 281                         }
 282                         if ( count( $varyHeader ) ) {
 283                                 $response->header( 'Vary: ' . implode( ', ', $varyHeader ) );
 284                         }
 285                         return;
 286                 } else {
 287                         wfThumbError( 404, "The given path of the specified thumbnail is incorrect;
 288                                 expected '" . $img->getThumbRel( $thumbName ) . "' but got '" .
 289                                 rawurldecode( $params['rel404'] ) . "'." );
 290                         return;
 291                 }
 292         }
 293
 294         // Suggest a good name for users downloading this thumbnail
 295         $headers[] = "Content-Disposition: {$img->getThumbDisposition( $thumbName )}";
 296
 297         if ( count( $varyHeader ) ) {
 298                 $headers[] = 'Vary: ' . implode( ', ', $varyHeader );
 299         }
 300
 301         // Stream the file if it exists already...
 302         $thumbPath = $img->getThumbPath( $thumbName );
 303         if ( $img->getRepo()->fileExists( $thumbPath ) ) {
 304                 $img->getRepo()->streamFile( $thumbPath, $headers );
 305                 return;
 306         }
 307
 308         $user = RequestContext::getMain()->getUser();
 309         if ( $user->pingLimiter( 'renderfile' ) ) {
 310                 wfThumbError( 500, wfMessage( 'actionthrottledtext' ) );
 311                 return;
 312         }
 313
 314         // Thumbnail isn't already there, so create the new thumbnail...
 315         try {
 316                 $thumb = $img->transform( $params, File::RENDER_NOW );
 317         } catch ( Exception $ex ) {
 318                 // Tried to select a page on a non-paged file?
 319                 $thumb = false;
 320         }
 321
 322         // Check for thumbnail generation errors...
 323         $errorMsg = false;
 324         $msg = wfMessage( 'thumbnail_error' );
 325         if ( !$thumb ) {
 326                 $errorMsg = $msg->rawParams( 'File::transform() returned false' )->escaped();
 327         } elseif ( $thumb->isError() ) {
 328                 $errorMsg = $thumb->getHtmlMsg();
 329         } elseif ( !$thumb->hasFile() ) {
 330                 $errorMsg = $msg->rawParams( 'No path supplied in thumbnail object' )->escaped();
 331         } elseif ( $thumb->fileIsSource() ) {
 332                 $errorMsg = $msg->
 333                         rawParams( 'Image was not scaled, is the requested width bigger than the source?' )->escaped();
 334         }
 335
 336         if ( $errorMsg !== false ) {
 337                 wfThumbError( 500, $errorMsg );
 338         } else {
 339                 // Stream the file if there were no errors
 340                 $thumb->streamFile( $headers );
 341         }
 342 }
 343
 344 /**
 345  * Convert pathinfo type parameter, into normal request parameters
 346  *
 347  * So for example, if the request was redirected from
 348  * /w/images/thumb/a/ab/Foo.png/120px-Foo.png. The $thumbRel parameter
 349  * of this function would be set to "a/ab/Foo.png/120px-Foo.png".
 350  * This method is responsible for turning that into an array
 351  * with the folowing keys:
 352  *  * f => the filename (Foo.png)
 353  *  * rel404 => the whole thing (a/ab/Foo.png/120px-Foo.png)
 354  *  * archived => 1 (If the request is for an archived thumb)
 355  *  * temp => 1 (If the file is in the "temporary" zone)
 356  *  * thumbName => the thumbnail name, including parameters (120px-Foo.png)
 357  *
 358  * Transform specific parameters are set later via wfExtractThumbParams().
 359  *
 360  * @param $thumbRel String Thumbnail path relative to the thumb zone
 361  * @return Array|null associative params array or null
 362  */
 363 function wfExtractThumbRequestInfo( $thumbRel ) {
 364         $repo = RepoGroup::singleton()->getLocalRepo();
 365
 366         $hashDirReg = $subdirReg = '';
 367         for ( $i = 0; $i < $repo->getHashLevels(); $i++ ) {
 368                 $subdirReg .= '[0-9a-f]';
 369                 $hashDirReg .= "$subdirReg/";
 370         }
 371
 372         // Check if this is a thumbnail of an original in the local file repo
 373         if ( preg_match( "!^((archive/)?$hashDirReg([^/]*)/([^/]*))$!", $thumbRel, $m ) ) {
 374                 list( /*all*/, $rel, $archOrTemp, $filename, $thumbname ) = $m;
 375         // Check if this is a thumbnail of an temp file in the local file repo
 376         } elseif ( preg_match( "!^(temp/)($hashDirReg([^/]*)/([^/]*))$!", $thumbRel, $m ) ) {
 377                 list( /*all*/, $archOrTemp, $rel, $filename, $thumbname ) = $m;
 378         } else {
 379                 return null; // not a valid looking thumbnail request
 380         }
 381
 382         $params = array( 'f' => $filename, 'rel404' => $rel );
 383         if ( $archOrTemp === 'archive/' ) {
 384                 $params['archived'] = 1;
 385         } elseif ( $archOrTemp === 'temp/' ) {
 386                 $params['temp'] = 1;
 387         }
 388
 389         $params['thumbName'] = $thumbname;
 390         return $params;
 391 }
 392
 393 /**
 394  * Convert a thumbnail name (122px-foo.png) to parameters, using
 395  * file handler.
 396  *
 397  * @param File $file File object for file in question.
 398  * @param $param Array Array of parameters so far.
 399  * @return Array parameters array with more parameters.
 400  */
 401 function wfExtractThumbParams( $file, $params ) {
 402         if ( !isset( $params['thumbName'] ) ) {
 403                 throw new MWException( "No thumbnail name passed to wfExtractThumbParams" );
 404         }
 405
 406         $thumbname = $params['thumbName'];
 407         unset( $params['thumbName'] );
 408
 409         // Do the hook first for older extensions that rely on it.
 410         if ( !wfRunHooks( 'ExtractThumbParameters', array( $thumbname, &$params ) ) ) {
 411                 // Check hooks if parameters can be extracted
 412                 // Hooks return false if they manage to *resolve* the parameters
 413                 // This hook should be considered deprecated
 414                 wfDeprecated( 'ExtractThumbParameters', '1.22' );
 415                 return $params; // valid thumbnail URL (via extension or config)
 416         }
 417
 418         // FIXME: Files in the temp zone don't set a mime type, which means
 419         // they don't have a handler. Which means we can't parse the param
 420         // string. However, not a big issue as what good is a param string
 421         // if you have no handler to make use of the param string and
 422         // actually generate the thumbnail.
 423         $handler = $file->getHandler();
 424
 425         // Based on UploadStash::parseKey
 426         $fileNamePos = strrpos( $thumbname, $params['f'] );
 427         if ( $fileNamePos === false ) {
 428                 // Maybe using a short filename? (see FileRepo::nameForThumb)
 429                 $fileNamePos = strrpos( $thumbname, 'thumbnail' );
 430         }
 431
 432         if ( $handler && $fileNamePos !== false ) {
 433                 $paramString = substr( $thumbname, 0, $fileNamePos - 1 );
 434                 $extraParams = $handler->parseParamString( $paramString );
 435                 if ( $extraParams !== false ) {
 436                         return $params + $extraParams;
 437                 }
 438         }
 439
 440         // As a last ditch fallback, use the traditional common parameters
 441         if ( preg_match( '!^(page(\d*)-)*(\d*)px-[^/]*$!', $thumbname, $matches ) ) {
 442                 list( /* all */, $pagefull, $pagenum, $size ) = $matches;
 443                 $params['width'] = $size;
 444                 if ( $pagenum ) {
 445                         $params['page'] = $pagenum;
 446                 }
 447                 return $params; // valid thumbnail URL
 448         }
 449         return null;
 450 }
 451
 452 /**
 453  * Output a thumbnail generation error message
 454  *
 455  * @param $status integer
 456  * @param $msg string
 457  * @return void
 458  */
 459 function wfThumbError( $status, $msg ) {
 460         global $wgShowHostnames;
 461
 462         header( 'Cache-Control: no-cache' );
 463         header( 'Content-Type: text/html; charset=utf-8' );
 464         if ( $status == 404 ) {
 465                 header( 'HTTP/1.1 404 Not found' );
 466         } elseif ( $status == 403 ) {
 467                 header( 'HTTP/1.1 403 Forbidden' );
 468                 header( 'Vary: Cookie' );
 469         } else {
 470                 header( 'HTTP/1.1 500 Internal server error' );
 471         }
 472         if ( $wgShowHostnames ) {
 473                 header( 'X-MW-Thumbnail-Renderer: ' . wfHostname() );
 474                 $url = htmlspecialchars( isset( $_SERVER['REQUEST_URI'] ) ? $_SERVER['REQUEST_URI'] : '' );
 475                 $hostname = htmlspecialchars( wfHostname() );
 476                 $debug = "<!-- $url -->\n<!-- $hostname -->\n";
 477         } else {
 478                 $debug = '';
 479         }
 480         echo <<<EOT
 481 <html><head><title>Error generating thumbnail</title></head>
 482 <body>
 483 <h1>Error generating thumbnail</h1>
 484 <p>
 485 $msg
 486 </p>
 487 $debug
 488 </body>
 489 </html>
 490
 491 EOT;
 492 }