includes/StreamFile.php

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