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                 $uri = new Uri( $uriPath );
  75                 $uriPath = $uri->getPath();
  76                 if ( $uriPath === null ) {
  77                         wfThumbError( 404, 'The source file for the specified thumbnail does not exist.' );
  78                         return;
  79                 }
  80         }
  81
  82         $params = wfExtractThumbParams( $uriPath ); // basic wiki URL param extracting
  83         if ( $params == null ) {
  84                 wfThumbError( 404, 'The source file for the specified thumbnail does not exist.' );
  85                 return;
  86         }
  87
  88         wfStreamThumb( $params ); // stream the thumbnail
  89 }
  90
  91 /**
  92  * Stream a thumbnail specified by parameters
  93  *
  94  * @param $params Array
  95  * @return void
  96  */
  97 function wfStreamThumb( array $params ) {
  98         global $wgVaryOnXFP;
  99         wfProfileIn( __METHOD__ );
 100
 101         $headers = array(); // HTTP headers to send
 102
 103         $fileName = isset( $params['f'] ) ? $params['f'] : '';
 104         unset( $params['f'] );
 105
 106         // Backwards compatibility parameters
 107         if ( isset( $params['w'] ) ) {
 108                 $params['width'] = $params['w'];
 109                 unset( $params['w'] );
 110         }
 111         if ( isset( $params['p'] ) ) {
 112                 $params['page'] = $params['p'];
 113         }
 114         unset( $params['r'] ); // ignore 'r' because we unconditionally pass File::RENDER
 115
 116         // Is this a thumb of an archived file?
 117         $isOld = ( isset( $params['archived'] ) && $params['archived'] );
 118         unset( $params['archived'] ); // handlers don't care
 119
 120         // Is this a thumb of a temp file?
 121         $isTemp = ( isset( $params['temp'] ) && $params['temp'] );
 122         unset( $params['temp'] ); // handlers don't care
 123
 124         // Some basic input validation
 125         $fileName = strtr( $fileName, '\\/', '__' );
 126
 127         // Actually fetch the image. Method depends on whether it is archived or not.
 128         if ( $isTemp ) {
 129                 $repo = RepoGroup::singleton()->getLocalRepo()->getTempRepo();
 130                 $img = new UnregisteredLocalFile( null, $repo,
 131                         # Temp files are hashed based on the name without the timestamp.
 132                         # The thumbnails will be hashed based on the entire name however.
 133                         # @TODO: fix this convention to actually be reasonable.
 134                         $repo->getZonePath( 'public' ) . '/' . $repo->getTempHashPath( $fileName ) . $fileName
 135                 );
 136         } elseif ( $isOld ) {
 137                 // Format is <timestamp>!<name>
 138                 $bits = explode( '!', $fileName, 2 );
 139                 if ( count( $bits ) != 2 ) {
 140                         wfThumbError( 404, wfMessage( 'badtitletext' )->text() );
 141                         wfProfileOut( __METHOD__ );
 142                         return;
 143                 }
 144                 $title = Title::makeTitleSafe( NS_FILE, $bits[1] );
 145                 if ( !$title ) {
 146                         wfThumbError( 404, wfMessage( 'badtitletext' )->text() );
 147                         wfProfileOut( __METHOD__ );
 148                         return;
 149                 }
 150                 $img = RepoGroup::singleton()->getLocalRepo()->newFromArchiveName( $title, $fileName );
 151         } else {
 152                 $img = wfLocalFile( $fileName );
 153         }
 154
 155         // Check permissions if there are read restrictions
 156         $varyHeader = array();
 157         if ( !in_array( 'read', User::getGroupPermissions( array( '*' ) ), true ) ) {
 158                 if ( !$img->getTitle() || !$img->getTitle()->userCan( 'read' ) ) {
 159                         wfThumbError( 403, 'Access denied. You do not have permission to access ' .
 160                                 'the source file.' );
 161                         wfProfileOut( __METHOD__ );
 162                         return;
 163                 }
 164                 $headers[] = 'Cache-Control: private';
 165                 $varyHeader[] = 'Cookie';
 166         }
 167
 168         // Check the source file storage path
 169         if ( !$img ) {
 170                 wfThumbError( 404, wfMessage( 'badtitletext' )->text() );
 171                 wfProfileOut( __METHOD__ );
 172                 return;
 173         }
 174         if ( !$img->exists() ) {
 175                 wfThumbError( 404, 'The source file for the specified thumbnail does not exist.' );
 176                 wfProfileOut( __METHOD__ );
 177                 return;
 178         }
 179         $sourcePath = $img->getPath();
 180         if ( $sourcePath === false ) {
 181                 wfThumbError( 500, 'The source file is not locally accessible.' );
 182                 wfProfileOut( __METHOD__ );
 183                 return;
 184         }
 185
 186         // Check IMS against the source file
 187         // This means that clients can keep a cached copy even after it has been deleted on the server
 188         if ( !empty( $_SERVER['HTTP_IF_MODIFIED_SINCE'] ) ) {
 189                 // Fix IE brokenness
 190                 $imsString = preg_replace( '/;.*$/', '', $_SERVER["HTTP_IF_MODIFIED_SINCE"] );
 191                 // Calculate time
 192                 wfSuppressWarnings();
 193                 $imsUnix = strtotime( $imsString );
 194                 wfRestoreWarnings();
 195                 $sourceTsUnix = wfTimestamp( TS_UNIX, $img->getTimestamp() );
 196                 if ( $sourceTsUnix <= $imsUnix ) {
 197                         header( 'HTTP/1.1 304 Not Modified' );
 198                         wfProfileOut( __METHOD__ );
 199                         return;
 200                 }
 201         }
 202
 203         $thumbName = $img->thumbName( $params );
 204         if ( !strlen( $thumbName ) ) { // invalid params?
 205                 wfThumbError( 400, 'The specified thumbnail parameters are not valid.' );
 206                 wfProfileOut( __METHOD__ );
 207                 return;
 208         }
 209
 210         $disposition = $img->getThumbDisposition( $thumbName );
 211         $headers[] = "Content-Disposition: $disposition";
 212
 213         // Stream the file if it exists already...
 214         try {
 215                 $thumbName2 = $img->thumbName( $params, File::THUMB_FULL_NAME ); // b/c; "long" style
 216                 // For 404 handled thumbnails, we only use the the base name of the URI
 217                 // for the thumb params and the parent directory for the source file name.
 218                 // Check that the zone relative path matches up so squid caches won't pick
 219                 // up thumbs that would not be purged on source file deletion (bug 34231).
 220                 if ( isset( $params['rel404'] ) ) { // thumbnail was handled via 404
 221                         if ( urldecode( $params['rel404'] ) === $img->getThumbRel( $thumbName ) ) {
 222                                 // Request for the canonical thumbnail name
 223                         } elseif ( urldecode( $params['rel404'] ) === $img->getThumbRel( $thumbName2 ) ) {
 224                                 // Request for the "long" thumbnail name; redirect to canonical name
 225                                 $response = RequestContext::getMain()->getRequest()->response();
 226                                 $response->header( "HTTP/1.1 301 " . HttpStatus::getMessage( 301 ) );
 227                                 $response->header( 'Location: ' . wfExpandUrl( $img->getThumbUrl( $thumbName ), PROTO_CURRENT ) );
 228                                 $response->header( 'Expires: ' .
 229                                         gmdate( 'D, d M Y H:i:s', time() + 7*86400 ) . ' GMT' );
 230                                 if ( $wgVaryOnXFP ) {
 231                                         $varyHeader[] = 'X-Forwarded-Proto';
 232                                 }
 233                                 if ( count( $varyHeader ) ) {
 234                                         $response->header( 'Vary: ' . implode( ', ', $varyHeader ) );
 235                                 }
 236                                 wfProfileOut( __METHOD__ );
 237                                 return;
 238                         } else {
 239                                 wfThumbError( 404, 'The given path of the specified thumbnail is incorrect.' );
 240                                 wfProfileOut( __METHOD__ );
 241                                 return;
 242                         }
 243                 }
 244                 $thumbPath = $img->getThumbPath( $thumbName );
 245                 if ( $img->getRepo()->fileExists( $thumbPath ) ) {
 246                         if ( count( $varyHeader ) ) {
 247                                 $headers[] = 'Vary: ' . implode( ', ', $varyHeader );
 248                         }
 249                         $img->getRepo()->streamFile( $thumbPath, $headers );
 250                         wfProfileOut( __METHOD__ );
 251                         return;
 252                 }
 253         } catch ( MWException $e ) {
 254                 wfThumbError( 500, $e->getHTML() );
 255                 wfProfileOut( __METHOD__ );
 256                 return;
 257         }
 258
 259         if ( count( $varyHeader ) ) {
 260                 $headers[] = 'Vary: ' . implode( ', ', $varyHeader );
 261         }
 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         // Zone URL might be relative ("/images") or protocol-relative ("//lang.site/image")
 306         $zoneUriPath = $repo->getZoneHandlerUrl( 'thumb' )
 307                 ? $repo->getZoneHandlerUrl( 'thumb' ) // custom URL
 308                 : $repo->getZoneUrl( 'thumb' ); // default to main URL
 309         $bits = wfParseUrl( wfExpandUrl( $zoneUriPath, PROTO_INTERNAL ) );
 310         if ( $bits && isset( $bits['path'] ) ) {
 311                 $zoneUriPath = $bits['path'];
 312         } else {
 313                 return null; // not a valid thumbnail URL
 314         }
 315
 316         $hashDirReg = $subdirReg = '';
 317         for ( $i = 0; $i < $repo->getHashLevels(); $i++ ) {
 318                 $subdirReg .= '[0-9a-f]';
 319                 $hashDirReg .= "$subdirReg/";
 320         }
 321         $zoneReg = preg_quote( $zoneUriPath ); // regex for thumb zone URI
 322
 323         // Check if this is a thumbnail of an original in the local file repo
 324         if ( preg_match( "!^$zoneReg/((archive/)?$hashDirReg([^/]*)/([^/]*))$!", $uriPath, $m ) ) {
 325                 list( /*all*/, $rel, $archOrTemp, $filename, $thumbname ) = $m;
 326         // Check if this is a thumbnail of an temp file in the local file repo
 327         } elseif ( preg_match( "!^$zoneReg/(temp/)($hashDirReg([^/]*)/([^/]*))$!", $uriPath, $m ) ) {
 328                 list( /*all*/, $archOrTemp, $rel, $filename, $thumbname ) = $m;
 329         } else {
 330                 return null; // not a valid looking thumbnail request
 331         }
 332
 333         $filename = urldecode( $filename );
 334         $thumbname = urldecode( $thumbname );
 335
 336         $params = array( 'f' => $filename, 'rel404' => $rel );
 337         if ( $archOrTemp === 'archive/' ) {
 338                 $params['archived'] = 1;
 339         } elseif ( $archOrTemp === 'temp/' ) {
 340                 $params['temp'] = 1;
 341         }
 342
 343         // Check if the parameters can be extracted from the thumbnail name...
 344         if ( preg_match( '!^(page(\d*)-)*(\d*)px-[^/]*$!', $thumbname, $matches ) ) {
 345                 list( /* all */, $pagefull, $pagenum, $size ) = $matches;
 346                 $params['width'] = $size;
 347                 if ( $pagenum ) {
 348                         $params['page'] = $pagenum;
 349                 }
 350                 return $params; // valid thumbnail URL
 351         // Hooks return false if they manage to *resolve* the parameters
 352         } elseif ( !wfRunHooks( 'ExtractThumbParameters', array( $thumbname, &$params ) ) ) {
 353                 return $params; // valid thumbnail URL (via extension or config)
 354         }
 355
 356         return null; // not a valid thumbnail URL
 357 }
 358
 359 /**
 360  * Output a thumbnail generation error message
 361  *
 362  * @param $status integer
 363  * @param $msg string
 364  * @return void
 365  */
 366 function wfThumbError( $status, $msg ) {
 367         global $wgShowHostnames;
 368
 369         header( 'Cache-Control: no-cache' );
 370         header( 'Content-Type: text/html; charset=utf-8' );
 371         if ( $status == 404 ) {
 372                 header( 'HTTP/1.1 404 Not found' );
 373         } elseif ( $status == 403 ) {
 374                 header( 'HTTP/1.1 403 Forbidden' );
 375                 header( 'Vary: Cookie' );
 376         } else {
 377                 header( 'HTTP/1.1 500 Internal server error' );
 378         }
 379         if ( $wgShowHostnames ) {
 380                 $url = htmlspecialchars( isset( $_SERVER['REQUEST_URI'] ) ? $_SERVER['REQUEST_URI'] : '' );
 381                 $hostname = htmlspecialchars( wfHostname() );
 382                 $debug = "<!-- $url -->\n<!-- $hostname -->\n";
 383         } else {
 384                 $debug = "";
 385         }
 386         echo <<<EOT
 387 <html><head><title>Error generating thumbnail</title></head>
 388 <body>
 389 <h1>Error generating thumbnail</h1>
 390 <p>
 391 $msg
 392 </p>
 393 $debug
 394 </body>
 395 </html>
 396
 397 EOT;
 398 }