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 if ( isset( $_SERVER['MW_COMPILED'] ) ) {
  26         require( 'core/includes/WebStart.php' );
  27 } else {
  28         require( __DIR__ . '/includes/WebStart.php' );
  29 }
  30
  31 // Don't use fancy mime detection, just check the file extension for jpg/gif/png
  32 $wgTrivialMimeDetection = true;
  33
  34 if ( defined( 'THUMB_HANDLER' ) ) {
  35         // Called from thumb_handler.php via 404; extract params from the URI...
  36         wfThumbHandle404();
  37 } else {
  38         // Called directly, use $_REQUEST params
  39         wfThumbHandleRequest();
  40 }
  41 wfLogProfilingData();
  42
  43 //--------------------------------------------------------------------------
  44
  45 /**
  46  * Handle a thumbnail request via query parameters
  47  *
  48  * @return void
  49  */
  50 function wfThumbHandleRequest() {
  51         $params = get_magic_quotes_gpc()
  52                 ? array_map( 'stripslashes', $_REQUEST )
  53                 : $_REQUEST;
  54
  55         wfStreamThumb( $params ); // stream the thumbnail
  56 }
  57
  58 /**
  59  * Handle a thumbnail request via thumbnail file URL
  60  *
  61  * @return void
  62  */
  63 function wfThumbHandle404() {
  64         # lighttpd puts the original request in REQUEST_URI, while sjs sets
  65         # that to the 404 handler, and puts the original request in REDIRECT_URL.
  66         if ( isset( $_SERVER['REDIRECT_URL'] ) ) {
  67                 # The URL is un-encoded, so put it back how it was
  68                 $uriPath = str_replace( "%2F", "/", urlencode( $_SERVER['REDIRECT_URL'] ) );
  69         } else {
  70                 $uriPath = $_SERVER['REQUEST_URI'];
  71         }
  72         # Just get the URI path (REDIRECT_URL/REQUEST_URI is either a full URL or a path)
  73         if ( substr( $uriPath, 0, 1 ) !== '/' ) {
  74                 $bits = wfParseUrl( $uriPath );
  75                 if ( $bits && isset( $bits['path'] ) ) {
  76                         $uriPath = $bits['path'];
  77                 } else {
  78                         wfThumbError( 404, 'The source file for the specified thumbnail does not exist.' );
  79                         return;
  80                 }
  81         }
  82
  83         $params = wfExtractThumbParams( $uriPath ); // basic wiki URL param extracting
  84         if ( $params == null ) {
  85                 wfThumbError( 404, 'The source file for the specified thumbnail does not exist.' );
  86                 return;
  87         }
  88
  89         wfStreamThumb( $params ); // stream the thumbnail
  90 }
  91
  92 /**
  93  * Stream a thumbnail specified by parameters
  94  *
  95  * @param $params Array
  96  * @return void
  97  */
  98 function wfStreamThumb( array $params ) {
  99         global $wgVaryOnXFP;
 100         wfProfileIn( __METHOD__ );
 101
 102         $headers = array(); // HTTP headers to send
 103
 104         $fileName = isset( $params['f'] ) ? $params['f'] : '';
 105         unset( $params['f'] );
 106
 107         // Backwards compatibility parameters
 108         if ( isset( $params['w'] ) ) {
 109                 $params['width'] = $params['w'];
 110                 unset( $params['w'] );
 111         }
 112         if ( isset( $params['p'] ) ) {
 113                 $params['page'] = $params['p'];
 114         }
 115         unset( $params['r'] ); // ignore 'r' because we unconditionally pass File::RENDER
 116
 117         // Is this a thumb of an archived file?
 118         $isOld = ( isset( $params['archived'] ) && $params['archived'] );
 119         unset( $params['archived'] ); // handlers don't care
 120
 121         // Is this a thumb of a temp file?
 122         $isTemp = ( isset( $params['temp'] ) && $params['temp'] );
 123         unset( $params['temp'] ); // handlers don't care
 124
 125         // Some basic input validation
 126         $fileName = strtr( $fileName, '\\/', '__' );
 127
 128         // Actually fetch the image. Method depends on whether it is archived or not.
 129         if ( $isTemp ) {
 130                 $repo = RepoGroup::singleton()->getLocalRepo()->getTempRepo();
 131                 $img = new UnregisteredLocalFile( null, $repo,
 132                         # Temp files are hashed based on the name without the timestamp.
 133                         # The thumbnails will be hashed based on the entire name however.
 134                         # @TODO: fix this convention to actually be reasonable.
 135                         $repo->getZonePath( 'public' ) . '/' . $repo->getTempHashPath( $fileName ) . $fileName
 136                 );
 137         } elseif ( $isOld ) {
 138                 // Format is <timestamp>!<name>
 139                 $bits = explode( '!', $fileName, 2 );
 140                 if ( count( $bits ) != 2 ) {
 141                         wfThumbError( 404, wfMessage( 'badtitletext' )->text() );
 142                         wfProfileOut( __METHOD__ );
 143                         return;
 144                 }
 145                 $title = Title::makeTitleSafe( NS_FILE, $bits[1] );
 146                 if ( !$title ) {
 147                         wfThumbError( 404, wfMessage( 'badtitletext' )->text() );
 148                         wfProfileOut( __METHOD__ );
 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                 wfProfileOut( __METHOD__ );
 160                 return;
 161         }
 162
 163         // Check permissions if there are read restrictions
 164         $varyHeader = array();
 165         if ( !in_array( 'read', User::getGroupPermissions( array( '*' ) ), true ) ) {
 166                 if ( !$img->getTitle() || !$img->getTitle()->userCan( 'read' ) ) {
 167                         wfThumbError( 403, 'Access denied. You do not have permission to access ' .
 168                                 'the source file.' );
 169                         wfProfileOut( __METHOD__ );
 170                         return;
 171                 }
 172                 $headers[] = 'Cache-Control: private';
 173                 $varyHeader[] = 'Cookie';
 174         }
 175
 176         // Check the source file storage path
 177         if ( !$img->exists() ) {
 178                 wfThumbError( 404, 'The source file for the specified thumbnail does not exist.' );
 179                 wfProfileOut( __METHOD__ );
 180                 return;
 181         }
 182         $sourcePath = $img->getPath();
 183         if ( $sourcePath === false ) {
 184                 wfThumbError( 500, 'The source file is not locally accessible.' );
 185                 wfProfileOut( __METHOD__ );
 186                 return;
 187         }
 188
 189         // Check IMS against the source file
 190         // This means that clients can keep a cached copy even after it has been deleted on the server
 191         if ( !empty( $_SERVER['HTTP_IF_MODIFIED_SINCE'] ) ) {
 192                 // Fix IE brokenness
 193                 $imsString = preg_replace( '/;.*$/', '', $_SERVER["HTTP_IF_MODIFIED_SINCE"] );
 194                 // Calculate time
 195                 wfSuppressWarnings();
 196                 $imsUnix = strtotime( $imsString );
 197                 wfRestoreWarnings();
 198                 $sourceTsUnix = wfTimestamp( TS_UNIX, $img->getTimestamp() );
 199                 if ( $sourceTsUnix <= $imsUnix ) {
 200                         header( 'HTTP/1.1 304 Not Modified' );
 201                         wfProfileOut( __METHOD__ );
 202                         return;
 203                 }
 204         }
 205
 206         $thumbName = $img->thumbName( $params );
 207         if ( !strlen( $thumbName ) ) { // invalid params?
 208                 wfThumbError( 400, 'The specified thumbnail parameters are not valid.' );
 209                 wfProfileOut( __METHOD__ );
 210                 return;
 211         }
 212
 213         $disposition = $img->getThumbDisposition( $thumbName );
 214         $headers[] = "Content-Disposition: $disposition";
 215
 216         // Stream the file if it exists already...
 217         try {
 218                 $thumbName2 = $img->thumbName( $params, File::THUMB_FULL_NAME ); // b/c; "long" style
 219                 // For 404 handled thumbnails, we only use the the base name of the URI
 220                 // for the thumb params and the parent directory for the source file name.
 221                 // Check that the zone relative path matches up so squid caches won't pick
 222                 // up thumbs that would not be purged on source file deletion (bug 34231).
 223                 if ( isset( $params['rel404'] ) ) { // thumbnail was handled via 404
 224                         if ( urldecode( $params['rel404'] ) === $img->getThumbRel( $thumbName ) ) {
 225                                 // Request for the canonical thumbnail name
 226                         } elseif ( urldecode( $params['rel404'] ) === $img->getThumbRel( $thumbName2 ) ) {
 227                                 // Request for the "long" thumbnail name; redirect to canonical name
 228                                 $response = RequestContext::getMain()->getRequest()->response();
 229                                 $response->header( "HTTP/1.1 301 " . HttpStatus::getMessage( 301 ) );
 230                                 $response->header( 'Location: ' . wfExpandUrl( $img->getThumbUrl( $thumbName ), PROTO_CURRENT ) );
 231                                 $response->header( 'Expires: ' .
 232                                         gmdate( 'D, d M Y H:i:s', time() + 7*86400 ) . ' GMT' );
 233                                 if ( $wgVaryOnXFP ) {
 234                                         $varyHeader[] = 'X-Forwarded-Proto';
 235                                 }
 236                                 if ( count( $varyHeader ) ) {
 237                                         $response->header( 'Vary: ' . implode( ', ', $varyHeader ) );
 238                                 }
 239                                 wfProfileOut( __METHOD__ );
 240                                 return;
 241                         } else {
 242                                 wfThumbError( 404, 'The given path of the specified thumbnail is incorrect.' );
 243                                 wfProfileOut( __METHOD__ );
 244                                 return;
 245                         }
 246                 }
 247                 $thumbPath = $img->getThumbPath( $thumbName );
 248                 if ( $img->getRepo()->fileExists( $thumbPath ) ) {
 249                         if ( count( $varyHeader ) ) {
 250                                 $headers[] = 'Vary: ' . implode( ', ', $varyHeader );
 251                         }
 252                         $img->getRepo()->streamFile( $thumbPath, $headers );
 253                         wfProfileOut( __METHOD__ );
 254                         return;
 255                 }
 256         } catch ( MWException $e ) {
 257                 wfThumbError( 500, $e->getHTML() );
 258                 wfProfileOut( __METHOD__ );
 259                 return;
 260         }
 261
 262         if ( count( $varyHeader ) ) {
 263                 $headers[] = 'Vary: ' . implode( ', ', $varyHeader );
 264         }
 265
 266         // Thumbnail isn't already there, so create the new thumbnail...
 267         try {
 268                 $thumb = $img->transform( $params, File::RENDER_NOW );
 269         } catch ( Exception $ex ) {
 270                 // Tried to select a page on a non-paged file?
 271                 $thumb = false;
 272         }
 273
 274         // Check for thumbnail generation errors...
 275         $errorMsg = false;
 276         $msg = wfMessage( 'thumbnail_error' );
 277         if ( !$thumb ) {
 278                 $errorMsg = $msg->rawParams( 'File::transform() returned false' )->escaped();
 279         } elseif ( $thumb->isError() ) {
 280                 $errorMsg = $thumb->getHtmlMsg();
 281         } elseif ( !$thumb->hasFile() ) {
 282                 $errorMsg = $msg->rawParams( 'No path supplied in thumbnail object' )->escaped();
 283         } elseif ( $thumb->fileIsSource() ) {
 284                 $errorMsg = $msg->
 285                         rawParams( 'Image was not scaled, is the requested width bigger than the source?' )->escaped();
 286         }
 287
 288         if ( $errorMsg !== false ) {
 289                 wfThumbError( 500, $errorMsg );
 290         } else {
 291                 // Stream the file if there were no errors
 292                 $thumb->streamFile( $headers );
 293         }
 294
 295         wfProfileOut( __METHOD__ );
 296 }
 297
 298 /**
 299  * Extract the required params for thumb.php from the thumbnail request URI.
 300  * At least 'width' and 'f' should be set if the result is an array.
 301  *
 302  * @param $uriPath String Thumbnail request URI path
 303  * @return Array|null associative params array or null
 304  */
 305 function wfExtractThumbParams( $uriPath ) {
 306         $repo = RepoGroup::singleton()->getLocalRepo();
 307
 308         // Zone URL might be relative ("/images") or protocol-relative ("//lang.site/image")
 309         $zoneUriPath = $repo->getZoneHandlerUrl( 'thumb' )
 310                 ? $repo->getZoneHandlerUrl( 'thumb' ) // custom URL
 311                 : $repo->getZoneUrl( 'thumb' ); // default to main URL
 312         $bits = wfParseUrl( wfExpandUrl( $zoneUriPath, PROTO_INTERNAL ) );
 313         if ( $bits && isset( $bits['path'] ) ) {
 314                 $zoneUriPath = $bits['path'];
 315         } else {
 316                 return null; // not a valid thumbnail URL
 317         }
 318
 319         $hashDirReg = $subdirReg = '';
 320         for ( $i = 0; $i < $repo->getHashLevels(); $i++ ) {
 321                 $subdirReg .= '[0-9a-f]';
 322                 $hashDirReg .= "$subdirReg/";
 323         }
 324         $zoneReg = preg_quote( $zoneUriPath ); // regex for thumb zone URI
 325
 326         // Check if this is a thumbnail of an original in the local file repo
 327         if ( preg_match( "!^$zoneReg/((archive/)?$hashDirReg([^/]*)/([^/]*))$!", $uriPath, $m ) ) {
 328                 list( /*all*/, $rel, $archOrTemp, $filename, $thumbname ) = $m;
 329         // Check if this is a thumbnail of an temp file in the local file repo
 330         } elseif ( preg_match( "!^$zoneReg/(temp/)($hashDirReg([^/]*)/([^/]*))$!", $uriPath, $m ) ) {
 331                 list( /*all*/, $archOrTemp, $rel, $filename, $thumbname ) = $m;
 332         } else {
 333                 return null; // not a valid looking thumbnail request
 334         }
 335
 336         $filename = urldecode( $filename );
 337         $thumbname = urldecode( $thumbname );
 338
 339         $params = array( 'f' => $filename, 'rel404' => $rel );
 340         if ( $archOrTemp === 'archive/' ) {
 341                 $params['archived'] = 1;
 342         } elseif ( $archOrTemp === 'temp/' ) {
 343                 $params['temp'] = 1;
 344         }
 345
 346         // Check if the parameters can be extracted from the thumbnail name...
 347         if ( preg_match( '!^(page(\d*)-)*(\d*)px-[^/]*$!', $thumbname, $matches ) ) {
 348                 list( /* all */, $pagefull, $pagenum, $size ) = $matches;
 349                 $params['width'] = $size;
 350                 if ( $pagenum ) {
 351                         $params['page'] = $pagenum;
 352                 }
 353                 return $params; // valid thumbnail URL
 354         // Hooks return false if they manage to *resolve* the parameters
 355         } elseif ( !wfRunHooks( 'ExtractThumbParameters', array( $thumbname, &$params ) ) ) {
 356                 return $params; // valid thumbnail URL (via extension or config)
 357         }
 358
 359         return null; // not a valid thumbnail URL
 360 }
 361
 362 /**
 363  * Output a thumbnail generation error message
 364  *
 365  * @param $status integer
 366  * @param $msg string
 367  * @return void
 368  */
 369 function wfThumbError( $status, $msg ) {
 370         global $wgShowHostnames;
 371
 372         header( 'Cache-Control: no-cache' );
 373         header( 'Content-Type: text/html; charset=utf-8' );
 374         if ( $status == 404 ) {
 375                 header( 'HTTP/1.1 404 Not found' );
 376         } elseif ( $status == 403 ) {
 377                 header( 'HTTP/1.1 403 Forbidden' );
 378                 header( 'Vary: Cookie' );
 379         } else {
 380                 header( 'HTTP/1.1 500 Internal server error' );
 381         }
 382         if ( $wgShowHostnames ) {
 383                 $url = htmlspecialchars( isset( $_SERVER['REQUEST_URI'] ) ? $_SERVER['REQUEST_URI'] : '' );
 384                 $hostname = htmlspecialchars( wfHostname() );
 385                 $debug = "<!-- $url -->\n<!-- $hostname -->\n";
 386         } else {
 387                 $debug = "";
 388         }
 389         echo <<<EOT
 390 <html><head><title>Error generating thumbnail</title></head>
 391 <body>
 392 <h1>Error generating thumbnail</h1>
 393 <p>
 394 $msg
 395 </p>
 396 $debug
 397 </body>
 398 </html>
 399
 400 EOT;
 401 }