thumb.php

   1 <?php
   2
   3 /**
   4  * PHP script to stream out an image thumbnail.
   5  *
   6  * @file
   7  * @ingroup Media
   8  */
   9 define( 'MW_NO_OUTPUT_COMPRESSION', 1 );
  10 if ( isset( $_SERVER['MW_COMPILED'] ) ) {
  11         require( 'core/includes/WebStart.php' );
  12 } else {
  13         require( dirname( __FILE__ ) . '/includes/WebStart.php' );
  14 }
  15
  16 // Don't use fancy mime detection, just check the file extension for jpg/gif/png
  17 $wgTrivialMimeDetection = true;
  18
  19 if ( defined( 'THUMB_HANDLER' ) ) {
  20         // Called from thumb_handler.php via 404; extract params from the URI...
  21         wfThumbHandle404();
  22 } else {
  23         // Called directly, use $_REQUEST params
  24         wfThumbHandleRequest();
  25 }
  26 wfLogProfilingData();
  27
  28 //--------------------------------------------------------------------------
  29
  30 /**
  31  * Handle a thumbnail request via query parameters
  32  *
  33  * @return void
  34  */
  35 function wfThumbHandleRequest() {
  36         $params = get_magic_quotes_gpc()
  37                 ? array_map( 'stripslashes', $_REQUEST )
  38                 : $_REQUEST;
  39
  40         wfStreamThumb( $params ); // stream the thumbnail
  41 }
  42
  43 /**
  44  * Handle a thumbnail request via thumbnail file URL
  45  *
  46  * @return void
  47  */
  48 function wfThumbHandle404() {
  49         # lighttpd puts the original request in REQUEST_URI, while sjs sets
  50         # that to the 404 handler, and puts the original request in REDIRECT_URL.
  51         if ( isset( $_SERVER['REDIRECT_URL'] ) ) {
  52                 # The URL is un-encoded, so put it back how it was
  53                 $uri = str_replace( "%2F", "/", urlencode( $_SERVER['REDIRECT_URL'] ) );
  54                 # Just get the URI path (REDIRECT_URL is either a full URL or a path)
  55                 if ( $uri[0] !== '/' ) {
  56                         $bits = wfParseUrl( $uri );
  57                         if ( $bits && isset( $bits['path'] ) ) {
  58                                 $uri = $bits['path'];
  59                         }
  60                 }
  61         } else {
  62                 $uri = $_SERVER['REQUEST_URI'];
  63         }
  64
  65         $params = wfExtractThumbParams( $uri ); // basic wiki URL param extracting
  66         if ( $params == null ) {
  67                 wfThumbError( 404, 'The source file for the specified thumbnail does not exist.' );
  68                 return;
  69         }
  70
  71         wfStreamThumb( $params ); // stream the thumbnail
  72 }
  73
  74 /**
  75  * Stream a thumbnail specified by parameters
  76  *
  77  * @param $params Array
  78  * @return void
  79  */
  80 function wfStreamThumb( array $params ) {
  81         wfProfileIn( __METHOD__ );
  82
  83         $headers = array(); // HTTP headers to send
  84
  85         $fileName = isset( $params['f'] ) ? $params['f'] : '';
  86         unset( $params['f'] );
  87
  88         // Backwards compatibility parameters
  89         if ( isset( $params['w'] ) ) {
  90                 $params['width'] = $params['w'];
  91                 unset( $params['w'] );
  92         }
  93         if ( isset( $params['p'] ) ) {
  94                 $params['page'] = $params['p'];
  95         }
  96         unset( $params['r'] ); // ignore 'r' because we unconditionally pass File::RENDER
  97
  98         // Is this a thumb of an archived file?
  99         $isOld = ( isset( $params['archived'] ) && $params['archived'] );
 100         unset( $params['archived'] ); // handlers don't care
 101
 102         // Is this a thumb of a temp file?
 103         $isTemp = ( isset( $params['temp'] ) && $params['temp'] );
 104         unset( $params['temp'] ); // handlers don't care
 105
 106         // Some basic input validation
 107         $fileName = strtr( $fileName, '\\/', '__' );
 108
 109         // Actually fetch the image. Method depends on whether it is archived or not.
 110         if ( $isOld ) {
 111                 // Format is <timestamp>!<name>
 112                 $bits = explode( '!', $fileName, 2 );
 113                 if ( count( $bits ) != 2 ) {
 114                         wfThumbError( 404, wfMsg( 'badtitletext' ) );
 115                         wfProfileOut( __METHOD__ );
 116                         return;
 117                 }
 118                 $title = Title::makeTitleSafe( NS_FILE, $bits[1] );
 119                 if ( !$title ) {
 120                         wfThumbError( 404, wfMsg( 'badtitletext' ) );
 121                         wfProfileOut( __METHOD__ );
 122                         return;
 123                 }
 124                 $img = RepoGroup::singleton()->getLocalRepo()->newFromArchiveName( $title, $fileName );
 125         } elseif ( $isTemp ) {
 126                 $repo = RepoGroup::singleton()->getLocalRepo()->getTempRepo();
 127                 // Format is <timestamp>!<name> or just <name>
 128                 $bits = explode( '!', $fileName, 2 );
 129                 // Get the name without the timestamp so hash paths are correctly computed
 130                 $title = Title::makeTitleSafe( NS_FILE, isset( $bits[1] ) ? $bits[1] : $fileName );
 131                 if ( !$title ) {
 132                         wfThumbError( 404, wfMsg( 'badtitletext' ) );
 133                         wfProfileOut( __METHOD__ );
 134                         return;
 135                 }
 136                 $img = new UnregisteredLocalFile( $title, $repo,
 137                         $repo->getZonePath( 'public' ) . '/' . $repo->getTempHashPath( $fileName ) . $fileName
 138                 );
 139         } else {
 140                 $img = wfLocalFile( $fileName );
 141         }
 142
 143         // Check permissions if there are read restrictions
 144         if ( !in_array( 'read', User::getGroupPermissions( array( '*' ) ), true ) ) {
 145                 if ( !$img->getTitle() || !$img->getTitle()->userCan( 'read' ) ) {
 146                         wfThumbError( 403, 'Access denied. You do not have permission to access ' .
 147                                 'the source file.' );
 148                         wfProfileOut( __METHOD__ );
 149                         return;
 150                 }
 151                 $headers[] = 'Cache-Control: private';
 152                 $headers[] = 'Vary: Cookie';
 153         }
 154
 155         // Check the source file storage path
 156         if ( !$img ) {
 157                 wfThumbError( 404, wfMsg( 'badtitletext' ) );
 158                 wfProfileOut( __METHOD__ );
 159                 return;
 160         }
 161         if ( !$img->exists() ) {
 162                 wfThumbError( 404, 'The source file for the specified thumbnail does not exist.' );
 163                 wfProfileOut( __METHOD__ );
 164                 return;
 165         }
 166         $sourcePath = $img->getPath();
 167         if ( $sourcePath === false ) {
 168                 wfThumbError( 500, 'The source file is not locally accessible.' );
 169                 wfProfileOut( __METHOD__ );
 170                 return;
 171         }
 172
 173         // Check IMS against the source file
 174         // This means that clients can keep a cached copy even after it has been deleted on the server
 175         if ( !empty( $_SERVER['HTTP_IF_MODIFIED_SINCE'] ) ) {
 176                 // Fix IE brokenness
 177                 $imsString = preg_replace( '/;.*$/', '', $_SERVER["HTTP_IF_MODIFIED_SINCE"] );
 178                 // Calculate time
 179                 wfSuppressWarnings();
 180                 $imsUnix = strtotime( $imsString );
 181                 wfRestoreWarnings();
 182                 $sourceTsUnix = wfTimestamp( TS_UNIX, $img->getTimestamp() );
 183                 if ( $sourceTsUnix <= $imsUnix ) {
 184                         header( 'HTTP/1.1 304 Not Modified' );
 185                         wfProfileOut( __METHOD__ );
 186                         return;
 187                 }
 188         }
 189
 190         // Stream the file if it exists already...
 191         try {
 192                 $thumbName = $img->thumbName( $params );
 193                 if ( strlen( $thumbName ) ) { // valid params?
 194                         // For 404 handled thumbnails, we only use the the base name of the URI
 195                         // for the thumb params and the parent directory for the source file name.
 196                         // Check that the zone relative path matches up so squid caches won't pick
 197                         // up thumbs that would not be purged on source file deletion (bug 34231).
 198                         if ( isset( $params['rel404'] ) // thumbnail was handled via 404
 199                                 && urldecode( $params['rel404'] ) !== $img->getThumbRel( $thumbName ) )
 200                         {
 201                                 wfThumbError( 404, 'The source file for the specified thumbnail does not exist.' );
 202                                 wfProfileOut( __METHOD__ );
 203                                 return;
 204                         }
 205                         $thumbPath = $img->getThumbPath( $thumbName );
 206                         if ( $img->getRepo()->fileExists( $thumbPath ) ) {
 207                                 $img->getRepo()->streamFile( $thumbPath, $headers );
 208                                 wfProfileOut( __METHOD__ );
 209                                 return;
 210                         }
 211                 }
 212         } catch ( MWException $e ) {
 213                 wfThumbError( 500, $e->getHTML() );
 214                 wfProfileOut( __METHOD__ );
 215                 return;
 216         }
 217
 218         // Thumbnail isn't already there, so create the new thumbnail...
 219         try {
 220                 $thumb = $img->transform( $params, File::RENDER_NOW );
 221         } catch ( Exception $ex ) {
 222                 // Tried to select a page on a non-paged file?
 223                 $thumb = false;
 224         }
 225
 226         // Check for thumbnail generation errors...
 227         $errorMsg = false;
 228         if ( !$thumb ) {
 229                 $errorMsg = wfMsgHtml( 'thumbnail_error', 'File::transform() returned false' );
 230         } elseif ( $thumb->isError() ) {
 231                 $errorMsg = $thumb->getHtmlMsg();
 232         } elseif ( !$thumb->hasFile() ) {
 233                 $errorMsg = wfMsgHtml( 'thumbnail_error', 'No path supplied in thumbnail object' );
 234         } elseif ( $thumb->fileIsSource() ) {
 235                 $errorMsg = wfMsgHtml( 'thumbnail_error',
 236                         'Image was not scaled, is the requested width bigger than the source?' );
 237         }
 238
 239         if ( $errorMsg !== false ) {
 240                 wfThumbError( 500, $errorMsg );
 241         } else {
 242                 // Stream the file if there were no errors
 243                 $thumb->streamFile( $headers );
 244         }
 245
 246         wfProfileOut( __METHOD__ );
 247 }
 248
 249 /**
 250  * Extract the required params for thumb.php from the thumbnail request URI.
 251  * At least 'width' and 'f' should be set if the result is an array.
 252  *
 253  * @param $uri String Thumbnail request URI path
 254  * @return Array|null associative params array or null
 255  */
 256 function wfExtractThumbParams( $uri ) {
 257         $repo = RepoGroup::singleton()->getLocalRepo();
 258
 259         $zoneURI = $repo->getZoneUrl( 'thumb' );
 260         if ( substr( $zoneURI, 0, 1 ) !== '/' ) {
 261                 $bits = wfParseUrl( $zoneURI );
 262                 if ( $bits && isset( $bits['path'] ) ) {
 263                         $zoneURI = $bits['path'];
 264                 } else {
 265                         return null;
 266                 }
 267         }
 268         $zoneUrlRegex = preg_quote( $zoneURI );
 269
 270         $hashDirRegex = $subdirRegex = '';
 271         for ( $i = 0; $i < $repo->getHashLevels(); $i++ ) {
 272                 $subdirRegex .= '[0-9a-f]';
 273                 $hashDirRegex .= "$subdirRegex/";
 274         }
 275
 276         $thumbUrlRegex = "!^$zoneUrlRegex/((archive/|temp/)?$hashDirRegex([^/]*)/([^/]*))$!";
 277
 278         // Check if this is a valid looking thumbnail request...
 279         if ( preg_match( $thumbUrlRegex, $uri, $matches ) ) {
 280                 list( /* all */, $rel, $archOrTemp, $filename, $thumbname ) = $matches;
 281                 $filename = urldecode( $filename );
 282                 $thumbname = urldecode( $thumbname );
 283
 284                 $params = array( 'f' => $filename, 'rel404' => $rel );
 285                 if ( $archOrTemp == 'archive/' ) {
 286                         $params['archived'] = 1;
 287                 } elseif ( $archOrTemp == 'temp/' ) {
 288                         $params['temp'] = 1;
 289                 }
 290
 291                 // Check if the parameters can be extracted from the thumbnail name...
 292                 if ( preg_match( '!^(page(\d*)-)*(\d*)px-[^/]*$!', $thumbname, $matches ) ) {
 293                         list( /* all */, $pagefull, $pagenum, $size ) = $matches;
 294                         $params['width'] = $size;
 295                         if ( $pagenum ) {
 296                                 $params['page'] = $pagenum;
 297                         }
 298                         return $params; // valid thumbnail URL
 299                 // Hooks return false if they manage to *resolve* the parameters
 300                 } elseif ( !wfRunHooks( 'ExtractThumbParameters', array( $thumbname, &$params ) ) ) {
 301                         return $params; // valid thumbnail URL (via extension or config)
 302                 }
 303         }
 304
 305         return null; // not a valid thumbnail URL
 306 }
 307
 308 /**
 309  * Output a thumbnail generation error message
 310  *
 311  * @param $status integer
 312  * @param $msg string
 313  * @return void
 314  */
 315 function wfThumbError( $status, $msg ) {
 316         global $wgShowHostnames;
 317
 318         header( 'Cache-Control: no-cache' );
 319         header( 'Content-Type: text/html; charset=utf-8' );
 320         if ( $status == 404 ) {
 321                 header( 'HTTP/1.1 404 Not found' );
 322         } elseif ( $status == 403 ) {
 323                 header( 'HTTP/1.1 403 Forbidden' );
 324                 header( 'Vary: Cookie' );
 325         } else {
 326                 header( 'HTTP/1.1 500 Internal server error' );
 327         }
 328         if ( $wgShowHostnames ) {
 329                 $url = htmlspecialchars( isset( $_SERVER['REQUEST_URI'] ) ? $_SERVER['REQUEST_URI'] : '' );
 330                 $hostname = htmlspecialchars( wfHostname() );
 331                 $debug = "<!-- $url -->\n<!-- $hostname -->\n";
 332         } else {
 333                 $debug = "";
 334         }
 335         echo <<<EOT
 336 <html><head><title>Error generating thumbnail</title></head>
 337 <body>
 338 <h1>Error generating thumbnail</h1>
 339 <p>
 340 $msg
 341 </p>
 342 $debug
 343 </body>
 344 </html>
 345
 346 EOT;
 347 }