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 permissions if there are read restrictions
 157         $varyHeader = array();
 158         if ( !in_array( 'read', User::getGroupPermissions( array( '*' ) ), true ) ) {
 159                 if ( !$img->getTitle() || !$img->getTitle()->userCan( 'read' ) ) {
 160                         wfThumbError( 403, 'Access denied. You do not have permission to access ' .
 161                                 'the source file.' );
 162                         wfProfileOut( __METHOD__ );
 163                         return;
 164                 }
 165                 $headers[] = 'Cache-Control: private';
 166                 $varyHeader[] = 'Cookie';
 167         }
 168
 169         // Check the source file storage path
 170         if ( !$img ) {
 171                 wfThumbError( 404, wfMessage( 'badtitletext' )->text() );
 172                 wfProfileOut( __METHOD__ );
 173                 return;
 174         }
 175         if ( !$img->exists() ) {
 176                 wfThumbError( 404, 'The source file for the specified thumbnail does not exist.' );
 177                 wfProfileOut( __METHOD__ );
 178                 return;
 179         }
 180         $sourcePath = $img->getPath();
 181         if ( $sourcePath === false ) {
 182                 wfThumbError( 500, 'The source file is not locally accessible.' );
 183                 wfProfileOut( __METHOD__ );
 184                 return;
 185         }
 186
 187         // Check IMS against the source file
 188         // This means that clients can keep a cached copy even after it has been deleted on the server
 189         if ( !empty( $_SERVER['HTTP_IF_MODIFIED_SINCE'] ) ) {
 190                 // Fix IE brokenness
 191                 $imsString = preg_replace( '/;.*$/', '', $_SERVER["HTTP_IF_MODIFIED_SINCE"] );
 192                 // Calculate time
 193                 wfSuppressWarnings();
 194                 $imsUnix = strtotime( $imsString );
 195                 wfRestoreWarnings();
 196                 $sourceTsUnix = wfTimestamp( TS_UNIX, $img->getTimestamp() );
 197                 if ( $sourceTsUnix <= $imsUnix ) {
 198                         header( 'HTTP/1.1 304 Not Modified' );
 199                         wfProfileOut( __METHOD__ );
 200                         return;
 201                 }
 202         }
 203
 204         $thumbName = $img->thumbName( $params );
 205         if ( !strlen( $thumbName ) ) { // invalid params?
 206                 wfThumbError( 400, 'The specified thumbnail parameters are not valid.' );
 207                 wfProfileOut( __METHOD__ );
 208                 return;
 209         }
 210
 211         $disposition = $img->getThumbDisposition( $thumbName );
 212         $headers[] = "Content-Disposition: $disposition";
 213
 214         // Stream the file if it exists already...
 215         try {
 216                 $thumbName2 = $img->thumbName( $params, File::THUMB_FULL_NAME ); // b/c; "long" style
 217                 // For 404 handled thumbnails, we only use the the base name of the URI
 218                 // for the thumb params and the parent directory for the source file name.
 219                 // Check that the zone relative path matches up so squid caches won't pick
 220                 // up thumbs that would not be purged on source file deletion (bug 34231).
 221                 if ( isset( $params['rel404'] ) ) { // thumbnail was handled via 404
 222                         if ( urldecode( $params['rel404'] ) === $img->getThumbRel( $thumbName ) ) {
 223                                 // Request for the canonical thumbnail name
 224                         } elseif ( urldecode( $params['rel404'] ) === $img->getThumbRel( $thumbName2 ) ) {
 225                                 // Request for the "long" thumbnail name; redirect to canonical name
 226                                 $response = RequestContext::getMain()->getRequest()->response();
 227                                 $response->header( "HTTP/1.1 301 " . HttpStatus::getMessage( 301 ) );
 228                                 $response->header( 'Location: ' . wfExpandUrl( $img->getThumbUrl( $thumbName ), PROTO_CURRENT ) );
 229                                 $response->header( 'Expires: ' .
 230                                         gmdate( 'D, d M Y H:i:s', time() + 7*86400 ) . ' GMT' );
 231                                 if ( $wgVaryOnXFP ) {
 232                                         $varyHeader[] = 'X-Forwarded-Proto';
 233                                 }
 234                                 if ( count( $varyHeader ) ) {
 235                                         $response->header( 'Vary: ' . implode( ', ', $varyHeader ) );
 236                                 }
 237                                 wfProfileOut( __METHOD__ );
 238                                 return;
 239                         } else {
 240                                 wfThumbError( 404, 'The given path of the specified thumbnail is incorrect.' );
 241                                 wfProfileOut( __METHOD__ );
 242                                 return;
 243                         }
 244                 }
 245                 $thumbPath = $img->getThumbPath( $thumbName );
 246                 if ( $img->getRepo()->fileExists( $thumbPath ) ) {
 247                         if ( count( $varyHeader ) ) {
 248                                 $headers[] = 'Vary: ' . implode( ', ', $varyHeader );
 249                         }
 250                         $img->getRepo()->streamFile( $thumbPath, $headers );
 251                         wfProfileOut( __METHOD__ );
 252                         return;
 253                 }
 254         } catch ( MWException $e ) {
 255                 wfThumbError( 500, $e->getHTML() );
 256                 wfProfileOut( __METHOD__ );
 257                 return;
 258         }
 259
 260         if ( count( $varyHeader ) ) {
 261                 $headers[] = 'Vary: ' . implode( ', ', $varyHeader );
 262         }
 263
 264         // Thumbnail isn't already there, so create the new thumbnail...
 265         try {
 266                 $thumb = $img->transform( $params, File::RENDER_NOW );
 267         } catch ( Exception $ex ) {
 268                 // Tried to select a page on a non-paged file?
 269                 $thumb = false;
 270         }
 271
 272         // Check for thumbnail generation errors...
 273         $errorMsg = false;
 274         $msg = wfMessage( 'thumbnail_error' );
 275         if ( !$thumb ) {
 276                 $errorMsg = $msg->rawParams( 'File::transform() returned false' )->escaped();
 277         } elseif ( $thumb->isError() ) {
 278                 $errorMsg = $thumb->getHtmlMsg();
 279         } elseif ( !$thumb->hasFile() ) {
 280                 $errorMsg = $msg->rawParams( 'No path supplied in thumbnail object' )->escaped();
 281         } elseif ( $thumb->fileIsSource() ) {
 282                 $errorMsg = $msg->
 283                         rawParams( 'Image was not scaled, is the requested width bigger than the source?' )->escaped();
 284         }
 285
 286         if ( $errorMsg !== false ) {
 287                 wfThumbError( 500, $errorMsg );
 288         } else {
 289                 // Stream the file if there were no errors
 290                 $thumb->streamFile( $headers );
 291         }
 292
 293         wfProfileOut( __METHOD__ );
 294 }
 295
 296 /**
 297  * Extract the required params for thumb.php from the thumbnail request URI.
 298  * At least 'width' and 'f' should be set if the result is an array.
 299  *
 300  * @param $uriPath String Thumbnail request URI path
 301  * @return Array|null associative params array or null
 302  */
 303 function wfExtractThumbParams( $uriPath ) {
 304         $repo = RepoGroup::singleton()->getLocalRepo();
 305
 306         // Zone URL might be relative ("/images") or protocol-relative ("//lang.site/image")
 307         $zoneUriPath = $repo->getZoneHandlerUrl( 'thumb' )
 308                 ? $repo->getZoneHandlerUrl( 'thumb' ) // custom URL
 309                 : $repo->getZoneUrl( 'thumb' ); // default to main URL
 310         $bits = wfParseUrl( wfExpandUrl( $zoneUriPath, PROTO_INTERNAL ) );
 311         if ( $bits && isset( $bits['path'] ) ) {
 312                 $zoneUriPath = $bits['path'];
 313         } else {
 314                 return null; // not a valid thumbnail URL
 315         }
 316
 317         $hashDirReg = $subdirReg = '';
 318         for ( $i = 0; $i < $repo->getHashLevels(); $i++ ) {
 319                 $subdirReg .= '[0-9a-f]';
 320                 $hashDirReg .= "$subdirReg/";
 321         }
 322         $zoneReg = preg_quote( $zoneUriPath ); // regex for thumb zone URI
 323
 324         // Check if this is a thumbnail of an original in the local file repo
 325         if ( preg_match( "!^$zoneReg/((archive/)?$hashDirReg([^/]*)/([^/]*))$!", $uriPath, $m ) ) {
 326                 list( /*all*/, $rel, $archOrTemp, $filename, $thumbname ) = $m;
 327         // Check if this is a thumbnail of an temp file in the local file repo
 328         } elseif ( preg_match( "!^$zoneReg/(temp/)($hashDirReg([^/]*)/([^/]*))$!", $uriPath, $m ) ) {
 329                 list( /*all*/, $archOrTemp, $rel, $filename, $thumbname ) = $m;
 330         } else {
 331                 return null; // not a valid looking thumbnail request
 332         }
 333
 334         $filename = urldecode( $filename );
 335         $thumbname = urldecode( $thumbname );
 336
 337         $params = array( 'f' => $filename, 'rel404' => $rel );
 338         if ( $archOrTemp === 'archive/' ) {
 339                 $params['archived'] = 1;
 340         } elseif ( $archOrTemp === 'temp/' ) {
 341                 $params['temp'] = 1;
 342         }
 343
 344         // Check if the parameters can be extracted from the thumbnail name...
 345         if ( preg_match( '!^(page(\d*)-)*(\d*)px-[^/]*$!', $thumbname, $matches ) ) {
 346                 list( /* all */, $pagefull, $pagenum, $size ) = $matches;
 347                 $params['width'] = $size;
 348                 if ( $pagenum ) {
 349                         $params['page'] = $pagenum;
 350                 }
 351                 return $params; // valid thumbnail URL
 352         // Hooks return false if they manage to *resolve* the parameters
 353         } elseif ( !wfRunHooks( 'ExtractThumbParameters', array( $thumbname, &$params ) ) ) {
 354                 return $params; // valid thumbnail URL (via extension or config)
 355         }
 356
 357         return null; // not a valid thumbnail URL
 358 }
 359
 360 /**
 361  * Output a thumbnail generation error message
 362  *
 363  * @param $status integer
 364  * @param $msg string
 365  * @return void
 366  */
 367 function wfThumbError( $status, $msg ) {
 368         global $wgShowHostnames;
 369
 370         header( 'Cache-Control: no-cache' );
 371         header( 'Content-Type: text/html; charset=utf-8' );
 372         if ( $status == 404 ) {
 373                 header( 'HTTP/1.1 404 Not found' );
 374         } elseif ( $status == 403 ) {
 375                 header( 'HTTP/1.1 403 Forbidden' );
 376                 header( 'Vary: Cookie' );
 377         } else {
 378                 header( 'HTTP/1.1 500 Internal server error' );
 379         }
 380         if ( $wgShowHostnames ) {
 381                 $url = htmlspecialchars( isset( $_SERVER['REQUEST_URI'] ) ? $_SERVER['REQUEST_URI'] : '' );
 382                 $hostname = htmlspecialchars( wfHostname() );
 383                 $debug = "<!-- $url -->\n<!-- $hostname -->\n";
 384         } else {
 385                 $debug = "";
 386         }
 387         echo <<<EOT
 388 <html><head><title>Error generating thumbnail</title></head>
 389 <body>
 390 <h1>Error generating thumbnail</h1>
 391 <p>
 392 $msg
 393 </p>
 394 $debug
 395 </body>
 396 </html>
 397
 398 EOT;
 399 }