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 = wfExtractThumbParams( $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
  92  * @return void
  93  */
  94 function wfStreamThumb( array $params ) {
  95         global $wgVaryOnXFP;
  96
  97         $section = new ProfileSection( __METHOD__ );
  98
  99         $headers = array(); // HTTP headers to send
 100
 101         $fileName = isset( $params['f'] ) ? $params['f'] : '';
 102         unset( $params['f'] );
 103
 104         // Backwards compatibility parameters
 105         if ( isset( $params['w'] ) ) {
 106                 $params['width'] = $params['w'];
 107                 unset( $params['w'] );
 108         }
 109         if ( isset( $params['p'] ) ) {
 110                 $params['page'] = $params['p'];
 111         }
 112         unset( $params['r'] ); // ignore 'r' because we unconditionally pass File::RENDER
 113
 114         // Is this a thumb of an archived file?
 115         $isOld = ( isset( $params['archived'] ) && $params['archived'] );
 116         unset( $params['archived'] ); // handlers don't care
 117
 118         // Is this a thumb of a temp file?
 119         $isTemp = ( isset( $params['temp'] ) && $params['temp'] );
 120         unset( $params['temp'] ); // handlers don't care
 121
 122         // Some basic input validation
 123         $fileName = strtr( $fileName, '\\/', '__' );
 124
 125         // Actually fetch the image. Method depends on whether it is archived or not.
 126         if ( $isTemp ) {
 127                 $repo = RepoGroup::singleton()->getLocalRepo()->getTempRepo();
 128                 $img = new UnregisteredLocalFile( null, $repo,
 129                         # Temp files are hashed based on the name without the timestamp.
 130                         # The thumbnails will be hashed based on the entire name however.
 131                         # @todo fix this convention to actually be reasonable.
 132                         $repo->getZonePath( 'public' ) . '/' . $repo->getTempHashPath( $fileName ) . $fileName
 133                 );
 134         } elseif ( $isOld ) {
 135                 // Format is <timestamp>!<name>
 136                 $bits = explode( '!', $fileName, 2 );
 137                 if ( count( $bits ) != 2 ) {
 138                         wfThumbError( 404, wfMessage( 'badtitletext' )->text() );
 139                         return;
 140                 }
 141                 $title = Title::makeTitleSafe( NS_FILE, $bits[1] );
 142                 if ( !$title ) {
 143                         wfThumbError( 404, wfMessage( 'badtitletext' )->text() );
 144                         return;
 145                 }
 146                 $img = RepoGroup::singleton()->getLocalRepo()->newFromArchiveName( $title, $fileName );
 147         } else {
 148                 $img = wfLocalFile( $fileName );
 149         }
 150
 151         // Check the source file title
 152         if ( !$img ) {
 153                 wfThumbError( 404, wfMessage( 'badtitletext' )->text() );
 154                 return;
 155         }
 156
 157         // Check permissions if there are read restrictions
 158         $varyHeader = array();
 159         if ( !in_array( 'read', User::getGroupPermissions( array( '*' ) ), true ) ) {
 160                 if ( !$img->getTitle() || !$img->getTitle()->userCan( 'read' ) ) {
 161                         wfThumbError( 403, 'Access denied. You do not have permission to access ' .
 162                                 'the source file.' );
 163                         return;
 164                 }
 165                 $headers[] = 'Cache-Control: private';
 166                 $varyHeader[] = 'Cookie';
 167         }
 168
 169         // Check the source file storage path
 170         if ( !$img->exists() ) {
 171                 $redirectedLocation = false;
 172                 if ( !$isTemp ) {
 173                         // Check for file redirect
 174                         if ( $isOld ) {
 175                                 // Since redirects are associated with pages, not versions of files,
 176                                 // we look for the most current version to see if its a redirect.
 177                                 $possibleRedirFile = RepoGroup::singleton()->getLocalRepo()->findFile( $img->getName() );
 178                         } else {
 179                                 $possibleRedirFile = RepoGroup::singleton()->getLocalRepo()->findFile( $fileName );
 180                         }
 181                         if ( $possibleRedirFile && !is_null( $possibleRedirFile->getRedirected() ) ) {
 182                                 $redirTarget = $possibleRedirFile->getName();
 183                                 $targetFile = wfLocalFile( Title::makeTitleSafe( NS_FILE, $redirTarget ) );
 184                                 if ( $targetFile->exists() ) {
 185                                         $newThumbName = $targetFile->thumbName( $params );
 186                                         if ( $isOld ) {
 187                                                 $newThumbUrl = $targetFile->getArchiveThumbUrl( $bits[0] . '!' . $targetFile->getName(), $newThumbName );
 188                                         } else {
 189                                                 $newThumbUrl = $targetFile->getThumbUrl( $newThumbName );
 190                                         }
 191                                         $redirectedLocation = wfExpandUrl( $newThumbUrl, PROTO_CURRENT );
 192                                 }
 193                         }
 194                 }
 195
 196                 if ( $redirectedLocation ) {
 197                         // File has been moved. Give redirect.
 198                         $response = RequestContext::getMain()->getRequest()->response();
 199                         $response->header( "HTTP/1.1 302 " . HttpStatus::getMessage( 302 ) );
 200                         $response->header( 'Location: ' . $redirectedLocation );
 201                         $response->header( 'Expires: ' .
 202                                 gmdate( 'D, d M Y H:i:s', time() + 12 * 3600 ) . ' GMT' );
 203                         if ( $wgVaryOnXFP ) {
 204                                 $varyHeader[] = 'X-Forwarded-Proto';
 205                         }
 206                         if ( count( $varyHeader ) ) {
 207                                 $response->header( 'Vary: ' . implode( ', ', $varyHeader ) );
 208                         }
 209                         return;
 210                 }
 211
 212                 // If its not a redirect that has a target as a local file, give 404.
 213                 wfThumbError( 404, "The source file '$fileName' does not exist." );
 214                 return;
 215         } elseif ( $img->getPath() === false ) {
 216                 wfThumbError( 500, "The source file '$fileName' is not locally accessible." );
 217                 return;
 218         }
 219
 220         // Check IMS against the source file
 221         // This means that clients can keep a cached copy even after it has been deleted on the server
 222         if ( !empty( $_SERVER['HTTP_IF_MODIFIED_SINCE'] ) ) {
 223                 // Fix IE brokenness
 224                 $imsString = preg_replace( '/;.*$/', '', $_SERVER["HTTP_IF_MODIFIED_SINCE"] );
 225                 // Calculate time
 226                 wfSuppressWarnings();
 227                 $imsUnix = strtotime( $imsString );
 228                 wfRestoreWarnings();
 229                 if ( wfTimestamp( TS_UNIX, $img->getTimestamp() ) <= $imsUnix ) {
 230                         header( 'HTTP/1.1 304 Not Modified' );
 231                         return;
 232                 }
 233         }
 234
 235         // Get the normalized thumbnail name from the parameters...
 236         try {
 237                 $thumbName = $img->thumbName( $params );
 238                 if ( !strlen( $thumbName ) ) { // invalid params?
 239                         wfThumbError( 400, 'The specified thumbnail parameters are not valid.' );
 240                         return;
 241                 }
 242                 $thumbName2 = $img->thumbName( $params, File::THUMB_FULL_NAME ); // b/c; "long" style
 243         } catch ( MWException $e ) {
 244                 wfThumbError( 500, $e->getHTML() );
 245                 return;
 246         }
 247
 248         // For 404 handled thumbnails, we only use the the base name of the URI
 249         // for the thumb params and the parent directory for the source file name.
 250         // Check that the zone relative path matches up so squid caches won't pick
 251         // up thumbs that would not be purged on source file deletion (bug 34231).
 252         if ( isset( $params['rel404'] ) ) { // thumbnail was handled via 404
 253                 if ( rawurldecode( $params['rel404'] ) === $img->getThumbRel( $thumbName ) ) {
 254                         // Request for the canonical thumbnail name
 255                 } elseif ( rawurldecode( $params['rel404'] ) === $img->getThumbRel( $thumbName2 ) ) {
 256                         // Request for the "long" thumbnail name; redirect to canonical name
 257                         $response = RequestContext::getMain()->getRequest()->response();
 258                         $response->header( "HTTP/1.1 301 " . HttpStatus::getMessage( 301 ) );
 259                         $response->header( 'Location: ' .
 260                                 wfExpandUrl( $img->getThumbUrl( $thumbName ), PROTO_CURRENT ) );
 261                         $response->header( 'Expires: ' .
 262                                 gmdate( 'D, d M Y H:i:s', time() + 7 * 86400 ) . ' GMT' );
 263                         if ( $wgVaryOnXFP ) {
 264                                 $varyHeader[] = 'X-Forwarded-Proto';
 265                         }
 266                         if ( count( $varyHeader ) ) {
 267                                 $response->header( 'Vary: ' . implode( ', ', $varyHeader ) );
 268                         }
 269                         return;
 270                 } else {
 271                         wfThumbError( 404, "The given path of the specified thumbnail is incorrect;
 272                                 expected '" . $img->getThumbRel( $thumbName ) . "' but got '" .
 273                                 rawurldecode( $params['rel404'] ) . "'." );
 274                         return;
 275                 }
 276         }
 277
 278         // Suggest a good name for users downloading this thumbnail
 279         $headers[] = "Content-Disposition: {$img->getThumbDisposition( $thumbName )}";
 280
 281         if ( count( $varyHeader ) ) {
 282                 $headers[] = 'Vary: ' . implode( ', ', $varyHeader );
 283         }
 284
 285         // Stream the file if it exists already...
 286         $thumbPath = $img->getThumbPath( $thumbName );
 287         if ( $img->getRepo()->fileExists( $thumbPath ) ) {
 288                 $img->getRepo()->streamFile( $thumbPath, $headers );
 289                 return;
 290         }
 291
 292         // Thumbnail isn't already there, so create the new thumbnail...
 293         try {
 294                 $thumb = $img->transform( $params, File::RENDER_NOW );
 295         } catch ( Exception $ex ) {
 296                 // Tried to select a page on a non-paged file?
 297                 $thumb = false;
 298         }
 299
 300         // Check for thumbnail generation errors...
 301         $errorMsg = false;
 302         $msg = wfMessage( 'thumbnail_error' );
 303         if ( !$thumb ) {
 304                 $errorMsg = $msg->rawParams( 'File::transform() returned false' )->escaped();
 305         } elseif ( $thumb->isError() ) {
 306                 $errorMsg = $thumb->getHtmlMsg();
 307         } elseif ( !$thumb->hasFile() ) {
 308                 $errorMsg = $msg->rawParams( 'No path supplied in thumbnail object' )->escaped();
 309         } elseif ( $thumb->fileIsSource() ) {
 310                 $errorMsg = $msg->
 311                         rawParams( 'Image was not scaled, is the requested width bigger than the source?' )->escaped();
 312         }
 313
 314         if ( $errorMsg !== false ) {
 315                 wfThumbError( 500, $errorMsg );
 316         } else {
 317                 // Stream the file if there were no errors
 318                 $thumb->streamFile( $headers );
 319         }
 320 }
 321
 322 /**
 323  * Extract the required params for thumb.php from the thumbnail request URI.
 324  * At least 'width' and 'f' should be set if the result is an array.
 325  *
 326  * @param $thumbRel String Thumbnail path relative to the thumb zone
 327  * @return Array|null associative params array or null
 328  */
 329 function wfExtractThumbParams( $thumbRel ) {
 330         $repo = RepoGroup::singleton()->getLocalRepo();
 331
 332         $hashDirReg = $subdirReg = '';
 333         for ( $i = 0; $i < $repo->getHashLevels(); $i++ ) {
 334                 $subdirReg .= '[0-9a-f]';
 335                 $hashDirReg .= "$subdirReg/";
 336         }
 337
 338         // Check if this is a thumbnail of an original in the local file repo
 339         if ( preg_match( "!^((archive/)?$hashDirReg([^/]*)/([^/]*))$!", $thumbRel, $m ) ) {
 340                 list( /*all*/, $rel, $archOrTemp, $filename, $thumbname ) = $m;
 341         // Check if this is a thumbnail of an temp file in the local file repo
 342         } elseif ( preg_match( "!^(temp/)($hashDirReg([^/]*)/([^/]*))$!", $thumbRel, $m ) ) {
 343                 list( /*all*/, $archOrTemp, $rel, $filename, $thumbname ) = $m;
 344         } else {
 345                 return null; // not a valid looking thumbnail request
 346         }
 347
 348         $params = array( 'f' => $filename, 'rel404' => $rel );
 349         if ( $archOrTemp === 'archive/' ) {
 350                 $params['archived'] = 1;
 351         } elseif ( $archOrTemp === 'temp/' ) {
 352                 $params['temp'] = 1;
 353         }
 354
 355         // Check hooks if parameters can be extracted
 356         // Hooks return false if they manage to *resolve* the parameters
 357         if ( !wfRunHooks( 'ExtractThumbParameters', array( $thumbname, &$params ) ) ) {
 358                 return $params; // valid thumbnail URL (via extension or config)
 359         // Check if the parameters can be extracted from the thumbnail name...
 360         } elseif ( preg_match( '!^(page(\d*)-)*(\d*)px-[^/]*$!', $thumbname, $matches ) ) {
 361                 list( /* all */, $pagefull, $pagenum, $size ) = $matches;
 362                 $params['width'] = $size;
 363                 if ( $pagenum ) {
 364                         $params['page'] = $pagenum;
 365                 }
 366                 return $params; // valid thumbnail URL
 367         }
 368
 369         return null; // not a valid thumbnail URL
 370 }
 371
 372 /**
 373  * Output a thumbnail generation error message
 374  *
 375  * @param $status integer
 376  * @param $msg string
 377  * @return void
 378  */
 379 function wfThumbError( $status, $msg ) {
 380         global $wgShowHostnames;
 381
 382         header( 'Cache-Control: no-cache' );
 383         header( 'Content-Type: text/html; charset=utf-8' );
 384         if ( $status == 404 ) {
 385                 header( 'HTTP/1.1 404 Not found' );
 386         } elseif ( $status == 403 ) {
 387                 header( 'HTTP/1.1 403 Forbidden' );
 388                 header( 'Vary: Cookie' );
 389         } else {
 390                 header( 'HTTP/1.1 500 Internal server error' );
 391         }
 392         if ( $wgShowHostnames ) {
 393                 $url = htmlspecialchars( isset( $_SERVER['REQUEST_URI'] ) ? $_SERVER['REQUEST_URI'] : '' );
 394                 $hostname = htmlspecialchars( wfHostname() );
 395                 $debug = "<!-- $url -->\n<!-- $hostname -->\n";
 396         } else {
 397                 $debug = '';
 398         }
 399         echo <<<EOT
 400 <html><head><title>Error generating thumbnail</title></head>
 401 <body>
 402 <h1>Error generating thumbnail</h1>
 403 <p>
 404 $msg
 405 </p>
 406 $debug
 407 </body>
 408 </html>
 409
 410 EOT;
 411 }