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( 'phase3/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'] );
 101
 102         // Some basic input validation
 103         $fileName = strtr( $fileName, '\\/', '__' );
 104
 105         // Actually fetch the image. Method depends on whether it is archived or not.
 106         if ( $isOld ) {
 107                 // Format is <timestamp>!<name>
 108                 $bits = explode( '!', $fileName, 2 );
 109                 if ( count( $bits ) != 2 ) {
 110                         wfThumbError( 404, wfMsg( 'badtitletext' ) );
 111                         wfProfileOut( __METHOD__ );
 112                         return;
 113                 }
 114                 $title = Title::makeTitleSafe( NS_FILE, $bits[1] );
 115                 if ( !$title ) {
 116                         wfThumbError( 404, wfMsg( 'badtitletext' ) );
 117                         wfProfileOut( __METHOD__ );
 118                         return;
 119                 }
 120                 $img = RepoGroup::singleton()->getLocalRepo()->newFromArchiveName( $title, $fileName );
 121         } else {
 122                 $img = wfLocalFile( $fileName );
 123         }
 124
 125         // Check permissions if there are read restrictions
 126         if ( !in_array( 'read', User::getGroupPermissions( array( '*' ) ), true ) ) {
 127                 if ( !$img->getTitle() || !$img->getTitle()->userCan( 'read' ) ) {
 128                         wfThumbError( 403, 'Access denied. You do not have permission to access ' .
 129                                 'the source file.' );
 130                         wfProfileOut( __METHOD__ );
 131                         return;
 132                 }
 133                 $headers[] = 'Cache-Control: private';
 134                 $headers[] = 'Vary: Cookie';
 135         }
 136
 137         // Check the source file storage path
 138         if ( !$img ) {
 139                 wfThumbError( 404, wfMsg( 'badtitletext' ) );
 140                 wfProfileOut( __METHOD__ );
 141                 return;
 142         }
 143         if ( !$img->exists() ) {
 144                 wfThumbError( 404, 'The source file for the specified thumbnail does not exist.' );
 145                 wfProfileOut( __METHOD__ );
 146                 return;
 147         }
 148         $sourcePath = $img->getPath();
 149         if ( $sourcePath === false ) {
 150                 wfThumbError( 500, 'The source file is not locally accessible.' );
 151                 wfProfileOut( __METHOD__ );
 152                 return;
 153         }
 154
 155         // Check IMS against the source file
 156         // This means that clients can keep a cached copy even after it has been deleted on the server
 157         if ( !empty( $_SERVER['HTTP_IF_MODIFIED_SINCE'] ) ) {
 158                 // Fix IE brokenness
 159                 $imsString = preg_replace( '/;.*$/', '', $_SERVER["HTTP_IF_MODIFIED_SINCE"] );
 160                 // Calculate time
 161                 wfSuppressWarnings();
 162                 $imsUnix = strtotime( $imsString );
 163                 wfRestoreWarnings();
 164                 $sourceTsUnix = wfTimestamp( TS_UNIX, $img->getTimestamp() );
 165                 if ( $sourceTsUnix <= $imsUnix ) {
 166                         header( 'HTTP/1.1 304 Not Modified' );
 167                         wfProfileOut( __METHOD__ );
 168                         return;
 169                 }
 170         }
 171
 172         // Stream the file if it exists already...
 173         try {
 174                 $thumbName = $img->thumbName( $params );
 175                 if ( strlen( $thumbName ) ) { // valid params?
 176                         // For 404 handled thumbnails, we only use the the base name of the URI
 177                         // for the thumb params and the parent directory for the source file name.
 178                         // Check that the zone relative path matches up so squid caches won't pick
 179                         // up thumbs that would not be purged on source file deletion (bug 34231).
 180                         if ( isset( $params['rel404'] ) // thumbnail was handled via 404
 181                                 && urldecode( $params['rel404'] ) !== $img->getThumbRel( $thumbName ) )
 182                         {
 183                                 wfThumbError( 404, 'The source file for the specified thumbnail does not exist.' );
 184                                 wfProfileOut( __METHOD__ );
 185                                 return;
 186                         }
 187                         $thumbPath = $img->getThumbPath( $thumbName );
 188                         if ( $img->getRepo()->fileExists( $thumbPath ) ) {
 189                                 $img->getRepo()->streamFile( $thumbPath, $headers );
 190                                 wfProfileOut( __METHOD__ );
 191                                 return;
 192                         }
 193                 }
 194         } catch ( MWException $e ) {
 195                 wfThumbError( 500, $e->getHTML() );
 196                 wfProfileOut( __METHOD__ );
 197                 return;
 198         }
 199
 200         // Thumbnail isn't already there, so create the new thumbnail...
 201         try {
 202                 $thumb = $img->transform( $params, File::RENDER_NOW );
 203         } catch ( Exception $ex ) {
 204                 // Tried to select a page on a non-paged file?
 205                 $thumb = false;
 206         }
 207
 208         // Check for thumbnail generation errors...
 209         $errorMsg = false;
 210         if ( !$thumb ) {
 211                 $errorMsg = wfMsgHtml( 'thumbnail_error', 'File::transform() returned false' );
 212         } elseif ( $thumb->isError() ) {
 213                 $errorMsg = $thumb->getHtmlMsg();
 214         } elseif ( !$thumb->hasFile() ) {
 215                 $errorMsg = wfMsgHtml( 'thumbnail_error', 'No path supplied in thumbnail object' );
 216         } elseif ( $thumb->fileIsSource() ) {
 217                 $errorMsg = wfMsgHtml( 'thumbnail_error',
 218                         'Image was not scaled, is the requested width bigger than the source?' );
 219         }
 220
 221         if ( $errorMsg !== false ) {
 222                 wfThumbError( 500, $errorMsg );
 223         } else {
 224                 // Stream the file if there were no errors
 225                 $thumb->streamFile( $headers );
 226         }
 227
 228         wfProfileOut( __METHOD__ );
 229 }
 230
 231 /**
 232  * Extract the required params for thumb.php from the thumbnail request URI.
 233  * At least 'width' and 'f' should be set if the result is an array.
 234  *
 235  * @param $uri String Thumbnail request URI path
 236  * @return Array|null associative params array or null
 237  */
 238 function wfExtractThumbParams( $uri ) {
 239         $repo = RepoGroup::singleton()->getLocalRepo();
 240
 241         $zoneURI = $repo->getZoneUrl( 'thumb' );
 242         if ( substr( $zoneURI, 0, 1 ) !== '/' ) {
 243                 $bits = wfParseUrl( $zoneURI );
 244                 if ( $bits && isset( $bits['path'] ) ) {
 245                         $zoneURI = $bits['path'];
 246                 } else {
 247                         return null;
 248                 }
 249         }
 250         $zoneUrlRegex = preg_quote( $zoneURI );
 251
 252         $hashDirRegex = $subdirRegex = '';
 253         for ( $i = 0; $i < $repo->getHashLevels(); $i++ ) {
 254                 $subdirRegex .= '[0-9a-f]';
 255                 $hashDirRegex .= "$subdirRegex/";
 256         }
 257
 258         $thumbUrlRegex = "!^$zoneUrlRegex/((archive/|temp/)?$hashDirRegex([^/]*)/([^/]*))$!";
 259
 260         // Check if this is a valid looking thumbnail request...
 261         if ( preg_match( $thumbUrlRegex, $uri, $matches ) ) {
 262                 list( /* all */, $rel, $archOrTemp, $filename, $thumbname ) = $matches;
 263                 $filename = urldecode( $filename );
 264                 $thumbname = urldecode( $thumbname );
 265
 266                 $params = array( 'f' => $filename, 'rel404' => $rel );
 267                 if ( $archOrTemp == 'archive/' ) {
 268                         $params['archived'] = 1;
 269                 } elseif ( $archOrTemp == 'temp/' ) {
 270                         $params['temp'] = 1;
 271                 }
 272
 273                 // Check if the parameters can be extracted from the thumbnail name...
 274                 if ( preg_match( '!^(page(\d*)-)*(\d*)px-[^/]*$!', $thumbname, $matches ) ) {
 275                         list( /* all */, $pagefull, $pagenum, $size ) = $matches;
 276                         $params['width'] = $size;
 277                         if ( $pagenum ) {
 278                                 $params['page'] = $pagenum;
 279                         }
 280                         return $params; // valid thumbnail URL
 281                 // Hooks return false if they manage to *resolve* the parameters
 282                 } elseif ( !wfRunHooks( 'ExtractThumbParameters', array( $thumbname, &$params ) ) ) {
 283                         return $params; // valid thumbnail URL (via extension or config)
 284                 }
 285         }
 286
 287         return null; // not a valid thumbnail URL
 288 }
 289
 290 /**
 291  * Output a thumbnail generation error message
 292  *
 293  * @param $status integer
 294  * @param $msg string
 295  * @return void
 296  */
 297 function wfThumbError( $status, $msg ) {
 298         global $wgShowHostnames;
 299
 300         header( 'Cache-Control: no-cache' );
 301         header( 'Content-Type: text/html; charset=utf-8' );
 302         if ( $status == 404 ) {
 303                 header( 'HTTP/1.1 404 Not found' );
 304         } elseif ( $status == 403 ) {
 305                 header( 'HTTP/1.1 403 Forbidden' );
 306                 header( 'Vary: Cookie' );
 307         } else {
 308                 header( 'HTTP/1.1 500 Internal server error' );
 309         }
 310         if ( $wgShowHostnames ) {
 311                 $url = htmlspecialchars( isset( $_SERVER['REQUEST_URI'] ) ? $_SERVER['REQUEST_URI'] : '' );
 312                 $hostname = htmlspecialchars( wfHostname() );
 313                 $debug = "<!-- $url -->\n<!-- $hostname -->\n";
 314         } else {
 315                 $debug = "";
 316         }
 317         echo <<<EOT
 318 <html><head><title>Error generating thumbnail</title></head>
 319 <body>
 320 <h1>Error generating thumbnail</h1>
 321 <p>
 322 $msg
 323 </p>
 324 $debug
 325 </body>
 326 </html>
 327
 328 EOT;
 329 }