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 $_GET params
  39         wfThumbHandleRequest();
  40 }
  41
  42 wfLogProfilingData();
  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         $wgArticlePath = false; # Don't let a "/*" article path clober our action path
  70
  71         $matches = WebRequest::getPathInfo();
  72         if ( !isset( $matches['title'] ) ) {
  73                 wfThumbError( 404, 'Could not determine the name of the requested thumbnail.' );
  74                 return;
  75         }
  76
  77         $params = wfExtractThumbParams( $matches['title'] ); // basic wiki URL param extracting
  78         if ( $params == null ) {
  79                 wfThumbError( 400, 'The specified thumbnail parameters are not recognized.' );
  80                 return;
  81         }
  82
  83         wfStreamThumb( $params ); // stream the thumbnail
  84 }
  85
  86 /**
  87  * Stream a thumbnail specified by parameters
  88  *
  89  * @param $params Array
  90  * @return void
  91  */
  92 function wfStreamThumb( array $params ) {
  93         global $wgVaryOnXFP;
  94
  95         wfProfileIn( __METHOD__ );
  96
  97         $headers = array(); // HTTP headers to send
  98
  99         $fileName = isset( $params['f'] ) ? $params['f'] : '';
 100         unset( $params['f'] );
 101
 102         // Backwards compatibility parameters
 103         if ( isset( $params['w'] ) ) {
 104                 $params['width'] = $params['w'];
 105                 unset( $params['w'] );
 106         }
 107         if ( isset( $params['p'] ) ) {
 108                 $params['page'] = $params['p'];
 109         }
 110         unset( $params['r'] ); // ignore 'r' because we unconditionally pass File::RENDER
 111
 112         // Is this a thumb of an archived file?
 113         $isOld = ( isset( $params['archived'] ) && $params['archived'] );
 114         unset( $params['archived'] ); // handlers don't care
 115
 116         // Is this a thumb of a temp file?
 117         $isTemp = ( isset( $params['temp'] ) && $params['temp'] );
 118         unset( $params['temp'] ); // handlers don't care
 119
 120         // Some basic input validation
 121         $fileName = strtr( $fileName, '\\/', '__' );
 122
 123         // Actually fetch the image. Method depends on whether it is archived or not.
 124         if ( $isTemp ) {
 125                 $repo = RepoGroup::singleton()->getLocalRepo()->getTempRepo();
 126                 $img = new UnregisteredLocalFile( null, $repo,
 127                         # Temp files are hashed based on the name without the timestamp.
 128                         # The thumbnails will be hashed based on the entire name however.
 129                         # @TODO: fix this convention to actually be reasonable.
 130                         $repo->getZonePath( 'public' ) . '/' . $repo->getTempHashPath( $fileName ) . $fileName
 131                 );
 132         } elseif ( $isOld ) {
 133                 // Format is <timestamp>!<name>
 134                 $bits = explode( '!', $fileName, 2 );
 135                 if ( count( $bits ) != 2 ) {
 136                         wfThumbError( 404, wfMessage( 'badtitletext' )->text() );
 137                         wfProfileOut( __METHOD__ );
 138                         return;
 139                 }
 140                 $title = Title::makeTitleSafe( NS_FILE, $bits[1] );
 141                 if ( !$title ) {
 142                         wfThumbError( 404, wfMessage( 'badtitletext' )->text() );
 143                         wfProfileOut( __METHOD__ );
 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                 wfProfileOut( __METHOD__ );
 155                 return;
 156         }
 157
 158         // Check permissions if there are read restrictions
 159         $varyHeader = array();
 160         if ( !in_array( 'read', User::getGroupPermissions( array( '*' ) ), true ) ) {
 161                 if ( !$img->getTitle() || !$img->getTitle()->userCan( 'read' ) ) {
 162                         wfThumbError( 403, 'Access denied. You do not have permission to access ' .
 163                                 'the source file.' );
 164                         wfProfileOut( __METHOD__ );
 165                         return;
 166                 }
 167                 $headers[] = 'Cache-Control: private';
 168                 $varyHeader[] = 'Cookie';
 169         }
 170
 171         // Check the source file storage path
 172         if ( !$img->exists() ) {
 173                 wfThumbError( 404, 'The source file for the specified thumbnail does not exist.' );
 174                 wfProfileOut( __METHOD__ );
 175                 return;
 176         } elseif ( $img->getPath() === false ) {
 177                 wfThumbError( 500, 'The source file is not locally accessible.' );
 178                 wfProfileOut( __METHOD__ );
 179                 return;
 180         }
 181
 182         // Check IMS against the source file
 183         // This means that clients can keep a cached copy even after it has been deleted on the server
 184         if ( !empty( $_SERVER['HTTP_IF_MODIFIED_SINCE'] ) ) {
 185                 // Fix IE brokenness
 186                 $imsString = preg_replace( '/;.*$/', '', $_SERVER["HTTP_IF_MODIFIED_SINCE"] );
 187                 // Calculate time
 188                 wfSuppressWarnings();
 189                 $imsUnix = strtotime( $imsString );
 190                 wfRestoreWarnings();
 191                 if ( wfTimestamp( TS_UNIX, $img->getTimestamp() ) <= $imsUnix ) {
 192                         header( 'HTTP/1.1 304 Not Modified' );
 193                         wfProfileOut( __METHOD__ );
 194                         return;
 195                 }
 196         }
 197
 198         // Get the normalized thumbnail name from the parameters...
 199         try {
 200                 $thumbName = $img->thumbName( $params );
 201                 if ( !strlen( $thumbName ) ) { // invalid params?
 202                         wfThumbError( 400, 'The specified thumbnail parameters are not valid.' );
 203                         wfProfileOut( __METHOD__ );
 204                         return;
 205                 }
 206                 $thumbName2 = $img->thumbName( $params, File::THUMB_FULL_NAME ); // b/c; "long" style
 207         } catch ( MWException $e ) {
 208                 wfThumbError( 500, $e->getHTML() );
 209                 wfProfileOut( __METHOD__ );
 210                 return;
 211         }
 212
 213         // For 404 handled thumbnails, we only use the the base name of the URI
 214         // for the thumb params and the parent directory for the source file name.
 215         // Check that the zone relative path matches up so squid caches won't pick
 216         // up thumbs that would not be purged on source file deletion (bug 34231).
 217         if ( isset( $params['rel404'] ) ) { // thumbnail was handled via 404
 218                 if ( rawurldecode( $params['rel404'] ) === $img->getThumbRel( $thumbName ) ) {
 219                         // Request for the canonical thumbnail name
 220                 } elseif ( rawurldecode( $params['rel404'] ) === $img->getThumbRel( $thumbName2 ) ) {
 221                         // Request for the "long" thumbnail name; redirect to canonical name
 222                         $response = RequestContext::getMain()->getRequest()->response();
 223                         $response->header( "HTTP/1.1 301 " . HttpStatus::getMessage( 301 ) );
 224                         $response->header( 'Location: ' .
 225                                 wfExpandUrl( $img->getThumbUrl( $thumbName ), PROTO_CURRENT ) );
 226                         $response->header( 'Expires: ' .
 227                                 gmdate( 'D, d M Y H:i:s', time() + 7*86400 ) . ' GMT' );
 228                         if ( $wgVaryOnXFP ) {
 229                                 $varyHeader[] = 'X-Forwarded-Proto';
 230                         }
 231                         if ( count( $varyHeader ) ) {
 232                                 $response->header( 'Vary: ' . implode( ', ', $varyHeader ) );
 233                         }
 234                         wfProfileOut( __METHOD__ );
 235                         return;
 236                 } else {
 237                         wfThumbError( 404, "The given path of the specified thumbnail is incorrect;
 238                                 expected '" . $img->getThumbRel( $thumbName ) . "' but got '" .
 239                                 rawurldecode( $params['rel404'] ) . "'." );
 240                         wfProfileOut( __METHOD__ );
 241                         return;
 242                 }
 243         }
 244
 245         // Suggest a good name for users downloading this thumbnail
 246         $headers[] = "Content-Disposition: {$img->getThumbDisposition( $thumbName )}";
 247
 248         if ( count( $varyHeader ) ) {
 249                 $headers[] = 'Vary: ' . implode( ', ', $varyHeader );
 250         }
 251
 252         // Stream the file if it exists already...
 253         $thumbPath = $img->getThumbPath( $thumbName );
 254         if ( $img->getRepo()->fileExists( $thumbPath ) ) {
 255                 $img->getRepo()->streamFile( $thumbPath, $headers );
 256                 wfProfileOut( __METHOD__ );
 257                 return;
 258         }
 259
 260         // Thumbnail isn't already there, so create the new thumbnail...
 261         try {
 262                 $thumb = $img->transform( $params, File::RENDER_NOW );
 263         } catch ( Exception $ex ) {
 264                 // Tried to select a page on a non-paged file?
 265                 $thumb = false;
 266         }
 267
 268         // Check for thumbnail generation errors...
 269         $errorMsg = false;
 270         $msg = wfMessage( 'thumbnail_error' );
 271         if ( !$thumb ) {
 272                 $errorMsg = $msg->rawParams( 'File::transform() returned false' )->escaped();
 273         } elseif ( $thumb->isError() ) {
 274                 $errorMsg = $thumb->getHtmlMsg();
 275         } elseif ( !$thumb->hasFile() ) {
 276                 $errorMsg = $msg->rawParams( 'No path supplied in thumbnail object' )->escaped();
 277         } elseif ( $thumb->fileIsSource() ) {
 278                 $errorMsg = $msg->
 279                         rawParams( 'Image was not scaled, is the requested width bigger than the source?' )->escaped();
 280         }
 281
 282         if ( $errorMsg !== false ) {
 283                 wfThumbError( 500, $errorMsg );
 284         } else {
 285                 // Stream the file if there were no errors
 286                 $thumb->streamFile( $headers );
 287         }
 288
 289         wfProfileOut( __METHOD__ );
 290 }
 291
 292 /**
 293  * Extract the required params for thumb.php from the thumbnail request URI.
 294  * At least 'width' and 'f' should be set if the result is an array.
 295  *
 296  * @param $thumbRel String Thumbnail path relative to the thumb zone
 297  * @return Array|null associative params array or null
 298  */
 299 function wfExtractThumbParams( $thumbRel ) {
 300         $repo = RepoGroup::singleton()->getLocalRepo();
 301
 302         $hashDirReg = $subdirReg = '';
 303         for ( $i = 0; $i < $repo->getHashLevels(); $i++ ) {
 304                 $subdirReg .= '[0-9a-f]';
 305                 $hashDirReg .= "$subdirReg/";
 306         }
 307
 308         // Check if this is a thumbnail of an original in the local file repo
 309         if ( preg_match( "!^((archive/)?$hashDirReg([^/]*)/([^/]*))$!", $thumbRel, $m ) ) {
 310                 list( /*all*/, $rel, $archOrTemp, $filename, $thumbname ) = $m;
 311         // Check if this is a thumbnail of an temp file in the local file repo
 312         } elseif ( preg_match( "!^(temp/)($hashDirReg([^/]*)/([^/]*))$!", $thumbRel, $m ) ) {
 313                 list( /*all*/, $archOrTemp, $rel, $filename, $thumbname ) = $m;
 314         } else {
 315                 return null; // not a valid looking thumbnail request
 316         }
 317
 318         $params = array( 'f' => $filename, 'rel404' => $rel );
 319         if ( $archOrTemp === 'archive/' ) {
 320                 $params['archived'] = 1;
 321         } elseif ( $archOrTemp === 'temp/' ) {
 322                 $params['temp'] = 1;
 323         }
 324
 325         // Check hooks if parameters can be extracted
 326         // Hooks return false if they manage to *resolve* the parameters
 327         if ( !wfRunHooks( 'ExtractThumbParameters', array( $thumbname, &$params ) ) ) {
 328                 return $params; // valid thumbnail URL (via extension or config)
 329         // Check if the parameters can be extracted from the thumbnail name...
 330         } elseif ( preg_match( '!^(page(\d*)-)*(\d*)px-[^/]*$!', $thumbname, $matches ) ) {
 331                 list( /* all */, $pagefull, $pagenum, $size ) = $matches;
 332                 $params['width'] = $size;
 333                 if ( $pagenum ) {
 334                         $params['page'] = $pagenum;
 335                 }
 336                 return $params; // valid thumbnail URL
 337         }
 338
 339         return null; // not a valid thumbnail URL
 340 }
 341
 342 /**
 343  * Output a thumbnail generation error message
 344  *
 345  * @param $status integer
 346  * @param $msg string
 347  * @return void
 348  */
 349 function wfThumbError( $status, $msg ) {
 350         global $wgShowHostnames;
 351
 352         header( 'Cache-Control: no-cache' );
 353         header( 'Content-Type: text/html; charset=utf-8' );
 354         if ( $status == 404 ) {
 355                 header( 'HTTP/1.1 404 Not found' );
 356         } elseif ( $status == 403 ) {
 357                 header( 'HTTP/1.1 403 Forbidden' );
 358                 header( 'Vary: Cookie' );
 359         } else {
 360                 header( 'HTTP/1.1 500 Internal server error' );
 361         }
 362         if ( $wgShowHostnames ) {
 363                 $url = htmlspecialchars( isset( $_SERVER['REQUEST_URI'] ) ? $_SERVER['REQUEST_URI'] : '' );
 364                 $hostname = htmlspecialchars( wfHostname() );
 365                 $debug = "<!-- $url -->\n<!-- $hostname -->\n";
 366         } else {
 367                 $debug = "";
 368         }
 369         echo <<<EOT
 370 <html><head><title>Error generating thumbnail</title></head>
 371 <body>
 372 <h1>Error generating thumbnail</h1>
 373 <p>
 374 $msg
 375 </p>
 376 $debug
 377 </body>
 378 </html>
 379
 380 EOT;
 381 }