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 $wgTrivialMimeDetection = true; //don't use fancy mime detection, just check the file extension for jpg/gif/png.
  17
  18 wfThumbMain();
  19 wfLogProfilingData();
  20
  21 //--------------------------------------------------------------------------
  22
  23 function wfThumbMain() {
  24         wfProfileIn( __METHOD__ );
  25
  26         $headers = array();
  27
  28         // Get input parameters
  29         if ( get_magic_quotes_gpc() ) {
  30                 $params = array_map( 'stripslashes', $_REQUEST );
  31         } else {
  32                 $params = $_REQUEST;
  33         }
  34
  35         $fileName = isset( $params['f'] ) ? $params['f'] : '';
  36         unset( $params['f'] );
  37
  38         // Backwards compatibility parameters
  39         if ( isset( $params['w'] ) ) {
  40                 $params['width'] = $params['w'];
  41                 unset( $params['w'] );
  42         }
  43         if ( isset( $params['p'] ) ) {
  44                 $params['page'] = $params['p'];
  45         }
  46         unset( $params['r'] ); // ignore 'r' because we unconditionally pass File::RENDER
  47
  48         // Is this a thumb of an archived file?
  49         $isOld = (isset( $params['archived'] ) && $params['archived']);
  50         unset( $params['archived'] );
  51
  52         // Some basic input validation
  53         $fileName = strtr( $fileName, '\\/', '__' );
  54
  55         // Actually fetch the image. Method depends on whether it is archived or not.
  56         if ( $isOld ) {
  57                 // Format is <timestamp>!<name>
  58                 $bits = explode( '!', $fileName, 2 );
  59                 if ( count( $bits ) != 2 ) {
  60                         wfThumbError( 404, wfMsg( 'badtitletext' ) );
  61                         wfProfileOut( __METHOD__ );
  62                         return;
  63                 }
  64                 $title = Title::makeTitleSafe( NS_FILE, $bits[1] );
  65                 if ( is_null( $title ) ) {
  66                         wfThumbError( 404, wfMsg( 'badtitletext' ) );
  67                         wfProfileOut( __METHOD__ );
  68                         return;
  69                 }
  70                 $img = RepoGroup::singleton()->getLocalRepo()->newFromArchiveName( $title, $fileName );
  71         } else {
  72                 $img = wfLocalFile( $fileName );
  73         }
  74
  75         // Check permissions if there are read restrictions
  76         if ( !in_array( 'read', User::getGroupPermissions( array( '*' ) ), true ) ) {
  77                 if ( !$img->getTitle()->userCanRead() ) {
  78                         wfThumbError( 403, 'Access denied. You do not have permission to access ' .
  79                                 'the source file.' );
  80                         wfProfileOut( __METHOD__ );
  81                         return;
  82                 }
  83                 $headers[] = 'Cache-Control: private';
  84                 $headers[] = 'Vary: Cookie';
  85         }
  86
  87         if ( !$img ) {
  88                 wfThumbError( 404, wfMsg( 'badtitletext' ) );
  89                 wfProfileOut( __METHOD__ );
  90                 return;
  91         }
  92         if ( !$img->exists() ) {
  93                 wfThumbError( 404, 'The source file for the specified thumbnail does not exist.' );
  94                 wfProfileOut( __METHOD__ );
  95                 return;
  96         }
  97         $sourcePath = $img->getPath();
  98         if ( $sourcePath === false ) {
  99                 wfThumbError( 500, 'The source file is not locally accessible.' );
 100                 wfProfileOut( __METHOD__ );
 101                 return;
 102         }
 103
 104         // Check IMS against the source file
 105         // This means that clients can keep a cached copy even after it has been deleted on the server
 106         if ( !empty( $_SERVER['HTTP_IF_MODIFIED_SINCE'] ) ) {
 107                 // Fix IE brokenness
 108                 $imsString = preg_replace( '/;.*$/', '', $_SERVER["HTTP_IF_MODIFIED_SINCE"] );
 109                 // Calculate time
 110                 wfSuppressWarnings();
 111                 $imsUnix = strtotime( $imsString );
 112                 $stat = stat( $sourcePath );
 113                 wfRestoreWarnings();
 114                 if ( $stat['mtime'] <= $imsUnix ) {
 115                         header( 'HTTP/1.1 304 Not Modified' );
 116                         wfProfileOut( __METHOD__ );
 117                         return;
 118                 }
 119         }
 120
 121         // Stream the file if it exists already...
 122         try {
 123                 $thumbName = $img->thumbName( $params );
 124                 if ( $thumbName !== false ) { // valid params?
 125                         $thumbPath = $img->getThumbPath( $thumbName );
 126                         if ( is_file( $thumbPath ) ) {
 127                                 StreamFile::stream( $thumbPath, $headers );
 128                                 wfProfileOut( __METHOD__ );
 129                                 return;
 130                         }
 131                 }
 132         } catch ( MWException $e ) {
 133                 wfThumbError( 500, $e->getHTML() );
 134                 wfProfileOut( __METHOD__ );
 135                 return;
 136         }
 137
 138         // Thumbnail isn't already there, so create the new thumbnail...
 139         try {
 140                 $thumb = $img->transform( $params, File::RENDER_NOW );
 141         } catch( Exception $ex ) {
 142                 // Tried to select a page on a non-paged file?
 143                 $thumb = false;
 144         }
 145
 146         // Check for thumbnail generation errors...
 147         $errorMsg = false;
 148         if ( !$thumb ) {
 149                 $errorMsg = wfMsgHtml( 'thumbnail_error', 'File::transform() returned false' );
 150         } elseif ( $thumb->isError() ) {
 151                 $errorMsg = $thumb->getHtmlMsg();
 152         } elseif ( !$thumb->getPath() ) {
 153                 $errorMsg = wfMsgHtml( 'thumbnail_error', 'No path supplied in thumbnail object' );
 154         } elseif ( $thumb->getPath() == $img->getPath() ) {
 155                 $errorMsg = wfMsgHtml( 'thumbnail_error', 'Image was not scaled, ' .
 156                         'is the requested width bigger than the source?' );
 157         }
 158
 159         if ( $errorMsg !== false ) {
 160                 wfThumbError( 500, $errorMsg );
 161         } else {
 162                 // Stream the file if there were no errors
 163                 StreamFile::stream( $thumb->getPath(), $headers );
 164         }
 165
 166         wfProfileOut( __METHOD__ );
 167 }
 168
 169 /**
 170  * @param $status
 171  * @param $msg
 172  */
 173 function wfThumbError( $status, $msg ) {
 174         global $wgShowHostnames;
 175         header( 'Cache-Control: no-cache' );
 176         header( 'Content-Type: text/html; charset=utf-8' );
 177         if ( $status == 404 ) {
 178                 header( 'HTTP/1.1 404 Not found' );
 179         } elseif ( $status == 403 ) {
 180                 header( 'HTTP/1.1 403 Forbidden' );
 181                 header( 'Vary: Cookie' );
 182         } else {
 183                 header( 'HTTP/1.1 500 Internal server error' );
 184         }
 185         if( $wgShowHostnames ) {
 186                 $url = htmlspecialchars( isset( $_SERVER['REQUEST_URI'] ) ? $_SERVER['REQUEST_URI'] : '' );
 187                 $hostname = htmlspecialchars( wfHostname() );
 188                 $debug = "<!-- $url -->\n<!-- $hostname -->\n";
 189         } else {
 190                 $debug = "";
 191         }
 192         echo <<<EOT
 193 <html><head><title>Error generating thumbnail</title></head>
 194 <body>
 195 <h1>Error generating thumbnail</h1>
 196 <p>
 197 $msg
 198 </p>
 199 $debug
 200 </body>
 201 </html>
 202
 203 EOT;
 204 }
 205