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 ( $isOld ) {
 130                 // Format is <timestamp>!<name>
 131                 $bits = explode( '!', $fileName, 2 );
 132                 if ( count( $bits ) != 2 ) {
 133                         wfThumbError( 404, wfMessage( 'badtitletext' )->text() );
 134                         wfProfileOut( __METHOD__ );
 135                         return;
 136                 }
 137                 $title = Title::makeTitleSafe( NS_FILE, $bits[1] );
 138                 if ( !$title ) {
 139                         wfThumbError( 404, wfMessage( 'badtitletext' )->text() );
 140                         wfProfileOut( __METHOD__ );
 141                         return;
 142                 }
 143                 $img = RepoGroup::singleton()->getLocalRepo()->newFromArchiveName( $title, $fileName );
 144         } elseif ( $isTemp ) {
 145                 $repo = RepoGroup::singleton()->getLocalRepo()->getTempRepo();
 146                 // Format is <timestamp>!<name> or just <name>
 147                 $bits = explode( '!', $fileName, 2 );
 148                 // Get the name without the timestamp so hash paths are correctly computed
 149                 $title = Title::makeTitleSafe( NS_FILE, isset( $bits[1] ) ? $bits[1] : $fileName );
 150                 if ( !$title ) {
 151                         wfThumbError( 404, wfMessage( 'badtitletext' )->text() );
 152                         wfProfileOut( __METHOD__ );
 153                         return;
 154                 }
 155                 $img = new UnregisteredLocalFile( $title, $repo,
 156                         $repo->getZonePath( 'public' ) . '/' . $repo->getTempHashPath( $fileName ) . $fileName
 157                 );
 158         } else {
 159                 $img = wfLocalFile( $fileName );
 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                         wfProfileOut( __METHOD__ );
 169                         return;
 170                 }
 171                 $headers[] = 'Cache-Control: private';
 172                 $varyHeader[] = 'Cookie';
 173         }
 174
 175         // Check the source file storage path
 176         if ( !$img ) {
 177                 wfThumbError( 404, wfMessage( 'badtitletext' )->text() );
 178                 wfProfileOut( __METHOD__ );
 179                 return;
 180         }
 181         if ( !$img->exists() ) {
 182                 wfThumbError( 404, 'The source file for the specified thumbnail does not exist.' );
 183                 wfProfileOut( __METHOD__ );
 184                 return;
 185         }
 186         $sourcePath = $img->getPath();
 187         if ( $sourcePath === false ) {
 188                 wfThumbError( 500, 'The source file is not locally accessible.' );
 189                 wfProfileOut( __METHOD__ );
 190                 return;
 191         }
 192
 193         // Check IMS against the source file
 194         // This means that clients can keep a cached copy even after it has been deleted on the server
 195         if ( !empty( $_SERVER['HTTP_IF_MODIFIED_SINCE'] ) ) {
 196                 // Fix IE brokenness
 197                 $imsString = preg_replace( '/;.*$/', '', $_SERVER["HTTP_IF_MODIFIED_SINCE"] );
 198                 // Calculate time
 199                 wfSuppressWarnings();
 200                 $imsUnix = strtotime( $imsString );
 201                 wfRestoreWarnings();
 202                 $sourceTsUnix = wfTimestamp( TS_UNIX, $img->getTimestamp() );
 203                 if ( $sourceTsUnix <= $imsUnix ) {
 204                         header( 'HTTP/1.1 304 Not Modified' );
 205                         wfProfileOut( __METHOD__ );
 206                         return;
 207                 }
 208         }
 209
 210         $thumbName = $img->thumbName( $params );
 211         if ( !strlen( $thumbName ) ) { // invalid params?
 212                 wfThumbError( 400, 'The specified thumbnail parameters are not valid.' );
 213                 wfProfileOut( __METHOD__ );
 214                 return;
 215         }
 216
 217         $disposition = $img->getThumbDisposition( $thumbName );
 218         $headers[] = "Content-Disposition: $disposition";
 219
 220         // Stream the file if it exists already...
 221         try {
 222                 $thumbName2 = $img->thumbName( $params, File::THUMB_FULL_NAME ); // b/c; "long" style
 223                 // For 404 handled thumbnails, we only use the the base name of the URI
 224                 // for the thumb params and the parent directory for the source file name.
 225                 // Check that the zone relative path matches up so squid caches won't pick
 226                 // up thumbs that would not be purged on source file deletion (bug 34231).
 227                 if ( isset( $params['rel404'] ) ) { // thumbnail was handled via 404
 228                         if ( urldecode( $params['rel404'] ) === $img->getThumbRel( $thumbName ) ) {
 229                                 // Request for the canonical thumbnail name
 230                         } elseif ( urldecode( $params['rel404'] ) === $img->getThumbRel( $thumbName2 ) ) {
 231                                 // Request for the "long" thumbnail name; redirect to canonical name
 232                                 $response = RequestContext::getMain()->getRequest()->response();
 233                                 $response->header( "HTTP/1.1 301 " . HttpStatus::getMessage( 301 ) );
 234                                 $response->header( 'Location: ' . wfExpandUrl( $img->getThumbUrl( $thumbName ), PROTO_CURRENT ) );
 235                                 $response->header( 'Expires: ' .
 236                                         gmdate( 'D, d M Y H:i:s', time() + 7*86400 ) . ' GMT' );
 237                                 if ( $wgVaryOnXFP ) {
 238                                         $varyHeader[] = 'X-Forwarded-Proto';
 239                                 }
 240                                 $response->header( 'Vary: ' . implode( ', ', $varyHeader ) );
 241                                 wfProfileOut( __METHOD__ );
 242                                 return;
 243                         } else {
 244                                 wfThumbError( 404, 'The source file for the specified thumbnail does not exist.' );
 245                                 wfProfileOut( __METHOD__ );
 246                                 return;
 247                         }
 248                 }
 249                 $thumbPath = $img->getThumbPath( $thumbName );
 250                 if ( $img->getRepo()->fileExists( $thumbPath ) ) {
 251                         $headers[] = 'Vary: ' . implode( ', ', $varyHeader );
 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         $headers[] = 'Vary: ' . implode( ', ', $varyHeader );
 262
 263         // Thumbnail isn't already there, so create the new thumbnail...
 264         try {
 265                 $thumb = $img->transform( $params, File::RENDER_NOW );
 266         } catch ( Exception $ex ) {
 267                 // Tried to select a page on a non-paged file?
 268                 $thumb = false;
 269         }
 270
 271         // Check for thumbnail generation errors...
 272         $errorMsg = false;
 273         $msg = wfMessage( 'thumbnail_error' );
 274         if ( !$thumb ) {
 275                 $errorMsg = $msg->rawParams( 'File::transform() returned false' )->escaped();
 276         } elseif ( $thumb->isError() ) {
 277                 $errorMsg = $thumb->getHtmlMsg();
 278         } elseif ( !$thumb->hasFile() ) {
 279                 $errorMsg = $msg->rawParams( 'No path supplied in thumbnail object' )->escaped();
 280         } elseif ( $thumb->fileIsSource() ) {
 281                 $errorMsg = $msg->
 282                         rawParams( 'Image was not scaled, is the requested width bigger than the source?' )->escaped();
 283         }
 284
 285         if ( $errorMsg !== false ) {
 286                 wfThumbError( 500, $errorMsg );
 287         } else {
 288                 // Stream the file if there were no errors
 289                 $thumb->streamFile( $headers );
 290         }
 291
 292         wfProfileOut( __METHOD__ );
 293 }
 294
 295 /**
 296  * Extract the required params for thumb.php from the thumbnail request URI.
 297  * At least 'width' and 'f' should be set if the result is an array.
 298  *
 299  * @param $uriPath String Thumbnail request URI path
 300  * @return Array|null associative params array or null
 301  */
 302 function wfExtractThumbParams( $uriPath ) {
 303         $repo = RepoGroup::singleton()->getLocalRepo();
 304
 305         $zoneUriPath = $repo->getZoneHandlerUrl( 'thumb' )
 306                 ? $repo->getZoneHandlerUrl( 'thumb' ) // custom URL
 307                 : $repo->getZoneUrl( 'thumb' ); // default to main URL
 308         // URL might be relative ("/images") or protocol-relative ("//lang.site/image")
 309         $bits = wfParseUrl( wfExpandUrl( $zoneUriPath, PROTO_INTERNAL ) );
 310         if ( $bits && isset( $bits['path'] ) ) {
 311                 $zoneUriPath = $bits['path'];
 312         } else {
 313                 return null;
 314         }
 315
 316         $hashDirRegex = $subdirRegex = '';
 317         for ( $i = 0; $i < $repo->getHashLevels(); $i++ ) {
 318                 $subdirRegex .= '[0-9a-f]';
 319                 $hashDirRegex .= "$subdirRegex/";
 320         }
 321
 322         $thumbPathRegex = "!^" . preg_quote( $zoneUriPath ) .
 323                 "/((archive/|temp/)?$hashDirRegex([^/]*)/([^/]*))$!";
 324
 325         // Check if this is a valid looking thumbnail request...
 326         if ( preg_match( $thumbPathRegex, $uriPath, $matches ) ) {
 327                 list( /* all */, $rel, $archOrTemp, $filename, $thumbname ) = $matches;
 328                 $filename = urldecode( $filename );
 329                 $thumbname = urldecode( $thumbname );
 330
 331                 $params = array( 'f' => $filename, 'rel404' => $rel );
 332                 if ( $archOrTemp == 'archive/' ) {
 333                         $params['archived'] = 1;
 334                 } elseif ( $archOrTemp == 'temp/' ) {
 335                         $params['temp'] = 1;
 336                 }
 337
 338                 // Check if the parameters can be extracted from the thumbnail name...
 339                 if ( preg_match( '!^(page(\d*)-)*(\d*)px-[^/]*$!', $thumbname, $matches ) ) {
 340                         list( /* all */, $pagefull, $pagenum, $size ) = $matches;
 341                         $params['width'] = $size;
 342                         if ( $pagenum ) {
 343                                 $params['page'] = $pagenum;
 344                         }
 345                         return $params; // valid thumbnail URL
 346                 // Hooks return false if they manage to *resolve* the parameters
 347                 } elseif ( !wfRunHooks( 'ExtractThumbParameters', array( $thumbname, &$params ) ) ) {
 348                         return $params; // valid thumbnail URL (via extension or config)
 349                 }
 350         }
 351
 352         return null; // not a valid thumbnail URL
 353 }
 354
 355 /**
 356  * Output a thumbnail generation error message
 357  *
 358  * @param $status integer
 359  * @param $msg string
 360  * @return void
 361  */
 362 function wfThumbError( $status, $msg ) {
 363         global $wgShowHostnames;
 364
 365         header( 'Cache-Control: no-cache' );
 366         header( 'Content-Type: text/html; charset=utf-8' );
 367         if ( $status == 404 ) {
 368                 header( 'HTTP/1.1 404 Not found' );
 369         } elseif ( $status == 403 ) {
 370                 header( 'HTTP/1.1 403 Forbidden' );
 371                 header( 'Vary: Cookie' );
 372         } else {
 373                 header( 'HTTP/1.1 500 Internal server error' );
 374         }
 375         if ( $wgShowHostnames ) {
 376                 $url = htmlspecialchars( isset( $_SERVER['REQUEST_URI'] ) ? $_SERVER['REQUEST_URI'] : '' );
 377                 $hostname = htmlspecialchars( wfHostname() );
 378                 $debug = "<!-- $url -->\n<!-- $hostname -->\n";
 379         } else {
 380                 $debug = "";
 381         }
 382         echo <<<EOT
 383 <html><head><title>Error generating thumbnail</title></head>
 384 <body>
 385 <h1>Error generating thumbnail</h1>
 386 <p>
 387 $msg
 388 </p>
 389 $debug
 390 </body>
 391 </html>
 392
 393 EOT;
 394 }