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 ( defined( 'THUMB_HANDLER' ) ) {
  30                 $params = $_REQUEST; // called from thumb_handler.php
  31         } else {
  32                 $params = get_magic_quotes_gpc()
  33                         ? array_map( 'stripslashes', $_REQUEST )
  34                         : $_REQUEST;
  35         }
  36
  37         $fileName = isset( $params['f'] ) ? $params['f'] : '';
  38         unset( $params['f'] );
  39
  40         // Backwards compatibility parameters
  41         if ( isset( $params['w'] ) ) {
  42                 $params['width'] = $params['w'];
  43                 unset( $params['w'] );
  44         }
  45         if ( isset( $params['p'] ) ) {
  46                 $params['page'] = $params['p'];
  47         }
  48         unset( $params['r'] ); // ignore 'r' because we unconditionally pass File::RENDER
  49
  50         // Is this a thumb of an archived file?
  51         $isOld = ( isset( $params['archived'] ) && $params['archived'] );
  52         unset( $params['archived'] );
  53
  54         // Some basic input validation
  55         $fileName = strtr( $fileName, '\\/', '__' );
  56
  57         // Actually fetch the image. Method depends on whether it is archived or not.
  58         if ( $isOld ) {
  59                 // Format is <timestamp>!<name>
  60                 $bits = explode( '!', $fileName, 2 );
  61                 if ( count( $bits ) != 2 ) {
  62                         wfThumbError( 404, wfMsg( 'badtitletext' ) );
  63                         wfProfileOut( __METHOD__ );
  64                         return;
  65                 }
  66                 $title = Title::makeTitleSafe( NS_FILE, $bits[1] );
  67                 if ( is_null( $title ) ) {
  68                         wfThumbError( 404, wfMsg( 'badtitletext' ) );
  69                         wfProfileOut( __METHOD__ );
  70                         return;
  71                 }
  72                 $img = RepoGroup::singleton()->getLocalRepo()->newFromArchiveName( $title, $fileName );
  73         } else {
  74                 $img = wfLocalFile( $fileName );
  75         }
  76
  77         // Check permissions if there are read restrictions
  78         if ( !in_array( 'read', User::getGroupPermissions( array( '*' ) ), true ) ) {
  79                 if ( !$img->getTitle()->userCanRead() ) {
  80                         wfThumbError( 403, 'Access denied. You do not have permission to access ' .
  81                                 'the source file.' );
  82                         wfProfileOut( __METHOD__ );
  83                         return;
  84                 }
  85                 $headers[] = 'Cache-Control: private';
  86                 $headers[] = 'Vary: Cookie';
  87         }
  88
  89         if ( !$img ) {
  90                 wfThumbError( 404, wfMsg( 'badtitletext' ) );
  91                 wfProfileOut( __METHOD__ );
  92                 return;
  93         }
  94         if ( !$img->exists() ) {
  95                 wfThumbError( 404, 'The source file for the specified thumbnail does not exist.' );
  96                 wfProfileOut( __METHOD__ );
  97                 return;
  98         }
  99         $sourcePath = $img->getPath();
 100         if ( $sourcePath === false ) {
 101                 wfThumbError( 500, 'The source file is not locally accessible.' );
 102                 wfProfileOut( __METHOD__ );
 103                 return;
 104         }
 105
 106         // Check IMS against the source file
 107         // This means that clients can keep a cached copy even after it has been deleted on the server
 108         if ( !empty( $_SERVER['HTTP_IF_MODIFIED_SINCE'] ) ) {
 109                 // Fix IE brokenness
 110                 $imsString = preg_replace( '/;.*$/', '', $_SERVER["HTTP_IF_MODIFIED_SINCE"] );
 111                 // Calculate time
 112                 wfSuppressWarnings();
 113                 $imsUnix = strtotime( $imsString );
 114                 $stat = stat( $sourcePath );
 115                 wfRestoreWarnings();
 116                 if ( $stat['mtime'] <= $imsUnix ) {
 117                         header( 'HTTP/1.1 304 Not Modified' );
 118                         wfProfileOut( __METHOD__ );
 119                         return;
 120                 }
 121         }
 122
 123         // Stream the file if it exists already...
 124         try {
 125                 $thumbName = $img->thumbName( $params );
 126                 if ( $thumbName !== false ) { // valid params?
 127                         $thumbPath = $img->getThumbPath( $thumbName );
 128                         if ( is_file( $thumbPath ) ) {
 129                                 StreamFile::stream( $thumbPath, $headers );
 130                                 wfProfileOut( __METHOD__ );
 131                                 return;
 132                         }
 133                 }
 134         } catch ( MWException $e ) {
 135                 wfThumbError( 500, $e->getHTML() );
 136                 wfProfileOut( __METHOD__ );
 137                 return;
 138         }
 139
 140         // Thumbnail isn't already there, so create the new thumbnail...
 141         try {
 142                 $thumb = $img->transform( $params, File::RENDER_NOW );
 143         } catch( Exception $ex ) {
 144                 // Tried to select a page on a non-paged file?
 145                 $thumb = false;
 146         }
 147
 148         // Check for thumbnail generation errors...
 149         $errorMsg = false;
 150         if ( !$thumb ) {
 151                 $errorMsg = wfMsgHtml( 'thumbnail_error', 'File::transform() returned false' );
 152         } elseif ( $thumb->isError() ) {
 153                 $errorMsg = $thumb->getHtmlMsg();
 154         } elseif ( !$thumb->getPath() ) {
 155                 $errorMsg = wfMsgHtml( 'thumbnail_error', 'No path supplied in thumbnail object' );
 156         } elseif ( $thumb->getPath() == $img->getPath() ) {
 157                 $errorMsg = wfMsgHtml( 'thumbnail_error', 'Image was not scaled, ' .
 158                         'is the requested width bigger than the source?' );
 159         }
 160
 161         if ( $errorMsg !== false ) {
 162                 wfThumbError( 500, $errorMsg );
 163         } else {
 164                 // Stream the file if there were no errors
 165                 StreamFile::stream( $thumb->getPath(), $headers );
 166         }
 167
 168         wfProfileOut( __METHOD__ );
 169 }
 170
 171 /**
 172  * @param $status
 173  * @param $msg
 174  */
 175 function wfThumbError( $status, $msg ) {
 176         global $wgShowHostnames;
 177         header( 'Cache-Control: no-cache' );
 178         header( 'Content-Type: text/html; charset=utf-8' );
 179         if ( $status == 404 ) {
 180                 header( 'HTTP/1.1 404 Not found' );
 181         } elseif ( $status == 403 ) {
 182                 header( 'HTTP/1.1 403 Forbidden' );
 183                 header( 'Vary: Cookie' );
 184         } else {
 185                 header( 'HTTP/1.1 500 Internal server error' );
 186         }
 187         if ( $wgShowHostnames ) {
 188                 $url = htmlspecialchars( isset( $_SERVER['REQUEST_URI'] ) ? $_SERVER['REQUEST_URI'] : '' );
 189                 $hostname = htmlspecialchars( wfHostname() );
 190                 $debug = "<!-- $url -->\n<!-- $hostname -->\n";
 191         } else {
 192                 $debug = "";
 193         }
 194         echo <<<EOT
 195 <html><head><title>Error generating thumbnail</title></head>
 196 <body>
 197 <h1>Error generating thumbnail</h1>
 198 <p>
 199 $msg
 200 </p>
 201 $debug
 202 </body>
 203 </html>
 204
 205 EOT;
 206 }
 207