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 require_once( './includes/WebStart.php' );
  11
  12 $wgTrivialMimeDetection = true; //don't use fancy mime detection, just check the file extension for jpg/gif/png.
  13
  14 require_once( "$IP/includes/StreamFile.php" );
  15
  16 wfThumbMain();
  17 wfLogProfilingData();
  18
  19 //--------------------------------------------------------------------------
  20
  21 function wfThumbMain() {
  22         wfProfileIn( __METHOD__ );
  23
  24         $headers = array();
  25
  26         // Get input parameters
  27         if ( get_magic_quotes_gpc() ) {
  28                 $params = array_map( 'stripslashes', $_REQUEST );
  29         } else {
  30                 $params = $_REQUEST;
  31         }
  32
  33         $fileName = isset( $params['f'] ) ? $params['f'] : '';
  34         unset( $params['f'] );
  35
  36         // Backwards compatibility parameters
  37         if ( isset( $params['w'] ) ) {
  38                 $params['width'] = $params['w'];
  39                 unset( $params['w'] );
  40         }
  41         if ( isset( $params['p'] ) ) {
  42                 $params['page'] = $params['p'];
  43         }
  44         unset( $params['r'] );
  45
  46         // Is this a thumb of an archived file?
  47         $isOld = (isset( $params['archived'] ) && $params['archived']);
  48         unset( $params['archived'] );
  49
  50         // Some basic input validation
  51         $fileName = strtr( $fileName, '\\/', '__' );
  52
  53         // Actually fetch the image. Method depends on whether it is archived or not.
  54         if( $isOld ) {
  55                 // Format is <timestamp>!<name>
  56                 $bits = explode( '!', $fileName, 2 );
  57                 if( !isset($bits[1]) ) {
  58                         wfThumbError( 404, wfMsg( 'badtitletext' ) );
  59                         return;
  60                 }
  61                 $title = Title::makeTitleSafe( NS_FILE, $bits[1] );
  62                 if( is_null($title) ) {
  63                         wfThumbError( 404, wfMsg( 'badtitletext' ) );
  64                         return;
  65                 }
  66                 $img = RepoGroup::singleton()->getLocalRepo()->newFromArchiveName( $title, $fileName );
  67         } else {
  68                 $img = wfLocalFile( $fileName );
  69         }
  70
  71         // Check permissions if there are read restrictions
  72         if ( !in_array( 'read', User::getGroupPermissions( array( '*' ) ), true ) ) {
  73                 if ( !$img->getTitle()->userCanRead() ) {
  74                         wfThumbError( 403, 'Access denied. You do not have permission to access ' .
  75                                 'the source file.' );
  76                         return;
  77                 }
  78                 $headers[] = 'Cache-Control: private';
  79                 $headers[] = 'Vary: Cookie';
  80         }
  81
  82         if ( !$img ) {
  83                 wfThumbError( 404, wfMsg( 'badtitletext' ) );
  84                 return;
  85         }
  86         if ( !$img->exists() ) {
  87                 wfThumbError( 404, 'The source file for the specified thumbnail does not exist.' );
  88                 return;
  89         }
  90         $sourcePath = $img->getPath();
  91         if ( $sourcePath === false ) {
  92                 wfThumbError( 500, 'The source file is not locally accessible.' );
  93                 return;
  94         }
  95
  96         // Check IMS against the source file
  97         // This means that clients can keep a cached copy even after it has been deleted on the server
  98         if ( !empty( $_SERVER['HTTP_IF_MODIFIED_SINCE'] ) ) {
  99                 // Fix IE brokenness
 100                 $imsString = preg_replace( '/;.*$/', '', $_SERVER["HTTP_IF_MODIFIED_SINCE"] );
 101                 // Calculate time
 102                 wfSuppressWarnings();
 103                 $imsUnix = strtotime( $imsString );
 104                 $stat = stat( $sourcePath );
 105                 wfRestoreWarnings();
 106                 if ( $stat['mtime'] <= $imsUnix ) {
 107                         header( 'HTTP/1.1 304 Not Modified' );
 108                         return;
 109                 }
 110         }
 111
 112         // Stream the file if it exists already
 113         try {
 114                 if ( false != ( $thumbName = $img->thumbName( $params ) ) ) {
 115                         $thumbPath = $img->getThumbPath( $thumbName );
 116
 117                         if ( is_file( $thumbPath ) ) {
 118                                 wfStreamFile( $thumbPath, $headers );
 119                                 return;
 120                         }
 121                 }
 122         } catch ( MWException $e ) {
 123                 wfThumbError( 500, $e->getHTML() );
 124                 return;
 125         }
 126
 127         try {
 128                 $thumb = $img->transform( $params, File::RENDER_NOW );
 129         } catch( Exception $ex ) {
 130                 // Tried to select a page on a non-paged file?
 131                 $thumb = false;
 132         }
 133
 134         $errorMsg = false;
 135         if ( !$thumb ) {
 136                 $errorMsg = wfMsgHtml( 'thumbnail_error', 'File::transform() returned false' );
 137         } elseif ( $thumb->isError() ) {
 138                 $errorMsg = $thumb->getHtmlMsg();
 139         } elseif ( !$thumb->getPath() ) {
 140                 $errorMsg = wfMsgHtml( 'thumbnail_error', 'No path supplied in thumbnail object' );
 141         } elseif ( $thumb->getPath() == $img->getPath() ) {
 142                 $errorMsg = wfMsgHtml( 'thumbnail_error', 'Image was not scaled, ' .
 143                         'is the requested width bigger than the source?' );
 144         } else {
 145                 wfStreamFile( $thumb->getPath(), $headers );
 146         }
 147         if ( $errorMsg !== false ) {
 148                 wfThumbError( 500, $errorMsg );
 149         }
 150
 151         wfProfileOut( __METHOD__ );
 152 }
 153
 154 function wfThumbError( $status, $msg ) {
 155         global $wgShowHostnames;
 156         header( 'Cache-Control: no-cache' );
 157         header( 'Content-Type: text/html; charset=utf-8' );
 158         if ( $status == 404 ) {
 159                 header( 'HTTP/1.1 404 Not found' );
 160         } elseif ( $status == 403 ) {
 161                 header( 'HTTP/1.1 403 Forbidden' );
 162                 header( 'Vary: Cookie' );
 163         } else {
 164                 header( 'HTTP/1.1 500 Internal server error' );
 165         }
 166         if( $wgShowHostnames ) {
 167                 $url = htmlspecialchars( isset( $_SERVER['REQUEST_URI'] ) ? $_SERVER['REQUEST_URI'] : '' );
 168                 $hostname = htmlspecialchars( wfHostname() );
 169                 $debug = "<!-- $url -->\n<!-- $hostname -->\n";
 170         } else {
 171                 $debug = "";
 172         }
 173         echo <<<EOT
 174 <html><head><title>Error generating thumbnail</title></head>
 175 <body>
 176 <h1>Error generating thumbnail</h1>
 177 <p>
 178 $msg
 179 </p>
 180 $debug
 181 </body>
 182 </html>
 183
 184 EOT;
 185 }
 186