includes/StreamFile.php

   1 <?php
   2 /**
   3  * Functions related to the output of file content
   4  *
   5  * @file
   6  */
   7
   8 /**
   9  * @param $fname string
  10  * @param $headers array
  11  */
  12 function wfStreamFile( $fname, $headers = array() ) {
  13         $stat = @stat( $fname );
  14         if ( !$stat ) {
  15                 header( 'HTTP/1.0 404 Not Found' );
  16                 header( 'Cache-Control: no-cache' );
  17                 header( 'Content-Type: text/html; charset=utf-8' );
  18                 $encFile = htmlspecialchars( $fname );
  19                 $encScript = htmlspecialchars( $_SERVER['SCRIPT_NAME'] );
  20                 echo "<html><body>
  21 <h1>File not found</h1>
  22 <p>Although this PHP script ($encScript) exists, the file requested for output
  23 ($encFile) does not.</p>
  24 </body></html>
  25 ";
  26                 return;
  27         }
  28
  29         header( 'Last-Modified: ' . gmdate( 'D, d M Y H:i:s', $stat['mtime'] ) . ' GMT' );
  30
  31         // Cancel output buffering and gzipping if set
  32         wfResetOutputBuffers();
  33
  34         $type = wfGetType( $fname );
  35         if ( $type and $type!="unknown/unknown") {
  36                 header("Content-type: $type");
  37         } else {
  38                 header('Content-type: application/x-wiki');
  39         }
  40
  41         // Don't stream it out as text/html if there was a PHP error
  42         if ( headers_sent() ) {
  43                 echo "Headers already sent, terminating.\n";
  44                 return;
  45         }
  46
  47         global $wgLanguageCode;
  48         header( "Content-Disposition: inline;filename*=utf-8'$wgLanguageCode'" . urlencode( basename( $fname ) ) );
  49
  50         foreach ( $headers as $header ) {
  51                 header( $header );
  52         }
  53
  54         if ( !empty( $_SERVER['HTTP_IF_MODIFIED_SINCE'] ) ) {
  55                 $modsince = preg_replace( '/;.*$/', '', $_SERVER['HTTP_IF_MODIFIED_SINCE'] );
  56                 $sinceTime = strtotime( $modsince );
  57                 if ( $stat['mtime'] <= $sinceTime ) {
  58                         ini_set('zlib.output_compression', 0);
  59                         header( "HTTP/1.0 304 Not Modified" );
  60                         return;
  61                 }
  62         }
  63
  64         header( 'Content-Length: ' . $stat['size'] );
  65
  66         readfile( $fname );
  67 }
  68
  69 /**
  70  * @param $filename string
  71  * @param $safe bool
  72  * @return null|string
  73  */
  74 function wfGetType( $filename, $safe = true ) {
  75         global $wgTrivialMimeDetection;
  76
  77         $ext = strrchr($filename, '.');
  78         $ext = $ext === false ? '' : strtolower( substr( $ext, 1 ) );
  79
  80         # trivial detection by file extension,
  81         # used for thumbnails (thumb.php)
  82         if ($wgTrivialMimeDetection) {
  83                 switch ($ext) {
  84                         case 'gif': return 'image/gif';
  85                         case 'png': return 'image/png';
  86                         case 'jpg': return 'image/jpeg';
  87                         case 'jpeg': return 'image/jpeg';
  88                 }
  89
  90                 return 'unknown/unknown';
  91         }
  92
  93         $magic = MimeMagic::singleton();
  94         // Use the extension only, rather than magic numbers, to avoid opening
  95         // up vulnerabilities due to uploads of files with allowed extensions
  96         // but disallowed types.
  97         $type = $magic->guessTypesForExtension( $ext );
  98
  99         /**
 100          * Double-check some security settings that were done on upload but might
 101          * have changed since.
 102          */
 103         if ( $safe ) {
 104                 global $wgFileBlacklist, $wgCheckFileExtensions, $wgStrictFileExtensions,
 105                         $wgFileExtensions, $wgVerifyMimeType, $wgMimeTypeBlacklist;
 106                 list( , $extList ) = UploadBase::splitExtensions( $filename );
 107                 if ( UploadBase::checkFileExtensionList( $extList, $wgFileBlacklist ) ) {
 108                         return 'unknown/unknown';
 109                 }
 110                 if ( $wgCheckFileExtensions && $wgStrictFileExtensions
 111                         && !UploadBase::checkFileExtensionList( $extList, $wgFileExtensions ) )
 112                 {
 113                         return 'unknown/unknown';
 114                 }
 115                 if ( $wgVerifyMimeType && in_array( strtolower( $type ), $wgMimeTypeBlacklist ) ) {
 116                         return 'unknown/unknown';
 117                 }
 118         }
 119         return $type;
 120 }