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( dirname( __FILE__ ) . '/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                 $uri = str_replace( "%2F", "/", urlencode( $_SERVER['REDIRECT_URL'] ) );
  69                 # Just get the URI path (REDIRECT_URL is either a full URL or a path)
  70                 if ( $uri[0] !== '/' ) {
  71                         $bits = wfParseUrl( $uri );
  72                         if ( $bits && isset( $bits['path'] ) ) {
  73                                 $uri = $bits['path'];
  74                         }
  75                 }
  76         } else {
  77                 $uri = $_SERVER['REQUEST_URI'];
  78         }
  79
  80         $params = wfExtractThumbParams( $uri ); // basic wiki URL param extracting
  81         if ( $params == null ) {
  82                 wfThumbError( 404, 'The source file for the specified thumbnail does not exist.' );
  83                 return;
  84         }
  85
  86         wfStreamThumb( $params ); // stream the thumbnail
  87 }
  88
  89 /**
  90  * Stream a thumbnail specified by parameters
  91  *
  92  * @param $params Array
  93  * @return void
  94  */
  95 function wfStreamThumb( array $params ) {
  96         wfProfileIn( __METHOD__ );
  97
  98         $headers = array(); // HTTP headers to send
  99
 100         $fileName = isset( $params['f'] ) ? $params['f'] : '';
 101         unset( $params['f'] );
 102
 103         // Backwards compatibility parameters
 104         if ( isset( $params['w'] ) ) {
 105                 $params['width'] = $params['w'];
 106                 unset( $params['w'] );
 107         }
 108         if ( isset( $params['p'] ) ) {
 109                 $params['page'] = $params['p'];
 110         }
 111         unset( $params['r'] ); // ignore 'r' because we unconditionally pass File::RENDER
 112
 113         // Is this a thumb of an archived file?
 114         $isOld = ( isset( $params['archived'] ) && $params['archived'] );
 115         unset( $params['archived'] ); // handlers don't care
 116
 117         // Is this a thumb of a temp file?
 118         $isTemp = ( isset( $params['temp'] ) && $params['temp'] );
 119         unset( $params['temp'] ); // handlers don't care
 120
 121         // Some basic input validation
 122         $fileName = strtr( $fileName, '\\/', '__' );
 123
 124         // Actually fetch the image. Method depends on whether it is archived or not.
 125         if ( $isOld ) {
 126                 // Format is <timestamp>!<name>
 127                 $bits = explode( '!', $fileName, 2 );
 128                 if ( count( $bits ) != 2 ) {
 129                         wfThumbError( 404, wfMsg( 'badtitletext' ) );
 130                         wfProfileOut( __METHOD__ );
 131                         return;
 132                 }
 133                 $title = Title::makeTitleSafe( NS_FILE, $bits[1] );
 134                 if ( !$title ) {
 135                         wfThumbError( 404, wfMsg( 'badtitletext' ) );
 136                         wfProfileOut( __METHOD__ );
 137                         return;
 138                 }
 139                 $img = RepoGroup::singleton()->getLocalRepo()->newFromArchiveName( $title, $fileName );
 140         } elseif ( $isTemp ) {
 141                 $repo = RepoGroup::singleton()->getLocalRepo()->getTempRepo();
 142                 // Format is <timestamp>!<name> or just <name>
 143                 $bits = explode( '!', $fileName, 2 );
 144                 // Get the name without the timestamp so hash paths are correctly computed
 145                 $title = Title::makeTitleSafe( NS_FILE, isset( $bits[1] ) ? $bits[1] : $fileName );
 146                 if ( !$title ) {
 147                         wfThumbError( 404, wfMsg( 'badtitletext' ) );
 148                         wfProfileOut( __METHOD__ );
 149                         return;
 150                 }
 151                 $img = new UnregisteredLocalFile( $title, $repo,
 152                         $repo->getZonePath( 'public' ) . '/' . $repo->getTempHashPath( $fileName ) . $fileName
 153                 );
 154         } else {
 155                 $img = wfLocalFile( $fileName );
 156         }
 157
 158         // Check permissions if there are read restrictions
 159         if ( !in_array( 'read', User::getGroupPermissions( array( '*' ) ), true ) ) {
 160                 if ( !$img->getTitle() || !$img->getTitle()->userCan( 'read' ) ) {
 161                         wfThumbError( 403, 'Access denied. You do not have permission to access ' .
 162                                 'the source file.' );
 163                         wfProfileOut( __METHOD__ );
 164                         return;
 165                 }
 166                 $headers[] = 'Cache-Control: private';
 167                 $headers[] = 'Vary: Cookie';
 168         }
 169
 170         // Check the source file storage path
 171         if ( !$img ) {
 172                 wfThumbError( 404, wfMsg( 'badtitletext' ) );
 173                 wfProfileOut( __METHOD__ );
 174                 return;
 175         }
 176         if ( !$img->exists() ) {
 177                 wfThumbError( 404, 'The source file for the specified thumbnail does not exist.' );
 178                 wfProfileOut( __METHOD__ );
 179                 return;
 180         }
 181         $sourcePath = $img->getPath();
 182         if ( $sourcePath === false ) {
 183                 wfThumbError( 500, 'The source file is not locally accessible.' );
 184                 wfProfileOut( __METHOD__ );
 185                 return;
 186         }
 187
 188         // Check IMS against the source file
 189         // This means that clients can keep a cached copy even after it has been deleted on the server
 190         if ( !empty( $_SERVER['HTTP_IF_MODIFIED_SINCE'] ) ) {
 191                 // Fix IE brokenness
 192                 $imsString = preg_replace( '/;.*$/', '', $_SERVER["HTTP_IF_MODIFIED_SINCE"] );
 193                 // Calculate time
 194                 wfSuppressWarnings();
 195                 $imsUnix = strtotime( $imsString );
 196                 wfRestoreWarnings();
 197                 $sourceTsUnix = wfTimestamp( TS_UNIX, $img->getTimestamp() );
 198                 if ( $sourceTsUnix <= $imsUnix ) {
 199                         header( 'HTTP/1.1 304 Not Modified' );
 200                         wfProfileOut( __METHOD__ );
 201                         return;
 202                 }
 203         }
 204
 205         // Stream the file if it exists already...
 206         try {
 207                 $thumbName = $img->thumbName( $params );
 208                 if ( strlen( $thumbName ) ) { // valid params?
 209                         // For 404 handled thumbnails, we only use the the base name of the URI
 210                         // for the thumb params and the parent directory for the source file name.
 211                         // Check that the zone relative path matches up so squid caches won't pick
 212                         // up thumbs that would not be purged on source file deletion (bug 34231).
 213                         if ( isset( $params['rel404'] ) // thumbnail was handled via 404
 214                                 && urldecode( $params['rel404'] ) !== $img->getThumbRel( $thumbName ) )
 215                         {
 216                                 wfThumbError( 404, 'The source file for the specified thumbnail does not exist.' );
 217                                 wfProfileOut( __METHOD__ );
 218                                 return;
 219                         }
 220                         $thumbPath = $img->getThumbPath( $thumbName );
 221                         if ( $img->getRepo()->fileExists( $thumbPath ) ) {
 222                                 $img->getRepo()->streamFile( $thumbPath, $headers );
 223                                 wfProfileOut( __METHOD__ );
 224                                 return;
 225                         }
 226                 }
 227         } catch ( MWException $e ) {
 228                 wfThumbError( 500, $e->getHTML() );
 229                 wfProfileOut( __METHOD__ );
 230                 return;
 231         }
 232
 233         // Thumbnail isn't already there, so create the new thumbnail...
 234         try {
 235                 $thumb = $img->transform( $params, File::RENDER_NOW );
 236         } catch ( Exception $ex ) {
 237                 // Tried to select a page on a non-paged file?
 238                 $thumb = false;
 239         }
 240
 241         // Check for thumbnail generation errors...
 242         $errorMsg = false;
 243         if ( !$thumb ) {
 244                 $errorMsg = wfMsgHtml( 'thumbnail_error', 'File::transform() returned false' );
 245         } elseif ( $thumb->isError() ) {
 246                 $errorMsg = $thumb->getHtmlMsg();
 247         } elseif ( !$thumb->hasFile() ) {
 248                 $errorMsg = wfMsgHtml( 'thumbnail_error', 'No path supplied in thumbnail object' );
 249         } elseif ( $thumb->fileIsSource() ) {
 250                 $errorMsg = wfMsgHtml( 'thumbnail_error',
 251                         'Image was not scaled, is the requested width bigger than the source?' );
 252         }
 253
 254         if ( $errorMsg !== false ) {
 255                 wfThumbError( 500, $errorMsg );
 256         } else {
 257                 // Stream the file if there were no errors
 258                 $thumb->streamFile( $headers );
 259         }
 260
 261         wfProfileOut( __METHOD__ );
 262 }
 263
 264 /**
 265  * Extract the required params for thumb.php from the thumbnail request URI.
 266  * At least 'width' and 'f' should be set if the result is an array.
 267  *
 268  * @param $uri String Thumbnail request URI path
 269  * @return Array|null associative params array or null
 270  */
 271 function wfExtractThumbParams( $uri ) {
 272         $repo = RepoGroup::singleton()->getLocalRepo();
 273
 274         $zoneURI = $repo->getZoneUrl( 'thumb' );
 275         if ( substr( $zoneURI, 0, 1 ) !== '/' ) {
 276                 $bits = wfParseUrl( $zoneURI );
 277                 if ( $bits && isset( $bits['path'] ) ) {
 278                         $zoneURI = $bits['path'];
 279                 } else {
 280                         return null;
 281                 }
 282         }
 283         $zoneUrlRegex = preg_quote( $zoneURI );
 284
 285         $hashDirRegex = $subdirRegex = '';
 286         for ( $i = 0; $i < $repo->getHashLevels(); $i++ ) {
 287                 $subdirRegex .= '[0-9a-f]';
 288                 $hashDirRegex .= "$subdirRegex/";
 289         }
 290
 291         $thumbUrlRegex = "!^$zoneUrlRegex/((archive/|temp/)?$hashDirRegex([^/]*)/([^/]*))$!";
 292
 293         // Check if this is a valid looking thumbnail request...
 294         if ( preg_match( $thumbUrlRegex, $uri, $matches ) ) {
 295                 list( /* all */, $rel, $archOrTemp, $filename, $thumbname ) = $matches;
 296                 $filename = urldecode( $filename );
 297                 $thumbname = urldecode( $thumbname );
 298
 299                 $params = array( 'f' => $filename, 'rel404' => $rel );
 300                 if ( $archOrTemp == 'archive/' ) {
 301                         $params['archived'] = 1;
 302                 } elseif ( $archOrTemp == 'temp/' ) {
 303                         $params['temp'] = 1;
 304                 }
 305
 306                 // Check if the parameters can be extracted from the thumbnail name...
 307                 if ( preg_match( '!^(page(\d*)-)*(\d*)px-[^/]*$!', $thumbname, $matches ) ) {
 308                         list( /* all */, $pagefull, $pagenum, $size ) = $matches;
 309                         $params['width'] = $size;
 310                         if ( $pagenum ) {
 311                                 $params['page'] = $pagenum;
 312                         }
 313                         return $params; // valid thumbnail URL
 314                 // Hooks return false if they manage to *resolve* the parameters
 315                 } elseif ( !wfRunHooks( 'ExtractThumbParameters', array( $thumbname, &$params ) ) ) {
 316                         return $params; // valid thumbnail URL (via extension or config)
 317                 }
 318         }
 319
 320         return null; // not a valid thumbnail URL
 321 }
 322
 323 /**
 324  * Output a thumbnail generation error message
 325  *
 326  * @param $status integer
 327  * @param $msg string
 328  * @return void
 329  */
 330 function wfThumbError( $status, $msg ) {
 331         global $wgShowHostnames;
 332
 333         header( 'Cache-Control: no-cache' );
 334         header( 'Content-Type: text/html; charset=utf-8' );
 335         if ( $status == 404 ) {
 336                 header( 'HTTP/1.1 404 Not found' );
 337         } elseif ( $status == 403 ) {
 338                 header( 'HTTP/1.1 403 Forbidden' );
 339                 header( 'Vary: Cookie' );
 340         } else {
 341                 header( 'HTTP/1.1 500 Internal server error' );
 342         }
 343         if ( $wgShowHostnames ) {
 344                 $url = htmlspecialchars( isset( $_SERVER['REQUEST_URI'] ) ? $_SERVER['REQUEST_URI'] : '' );
 345                 $hostname = htmlspecialchars( wfHostname() );
 346                 $debug = "<!-- $url -->\n<!-- $hostname -->\n";
 347         } else {
 348                 $debug = "";
 349         }
 350         echo <<<EOT
 351 <html><head><title>Error generating thumbnail</title></head>
 352 <body>
 353 <h1>Error generating thumbnail</h1>
 354 <p>
 355 $msg
 356 </p>
 357 $debug
 358 </body>
 359 </html>
 360
 361 EOT;
 362 }