lib/xsendfilelib.php

   1 <?php
   2 // This file is part of Moodle - http://moodle.org/
   3 //
   4 // Moodle is free software: you can redistribute it and/or modify
   5 // it under the terms of the GNU General Public License as published by
   6 // the Free Software Foundation, either version 3 of the License, or
   7 // (at your option) any later version.
   8 //
   9 // Moodle is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13 //
  14 // You should have received a copy of the GNU General Public License
  15 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  16
  17 /**
  18  * X-Sendfile support
  19  *
  20  * @package   core
  21  * @copyright 2012 Petr Skoda {@link http://skodak.org}
  22  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  23  */
  24
  25 /**
  26  * Serve files using the X-Sendfile header.
  27  *
  28  * This needs special server module or configuration.
  29  * Please make sure that all headers are already sent and the all access control checks passed.
  30  *
  31  * @param string $filepath
  32  * @return bool success
  33  */
  34 function xsendfile($filepath) {
  35     global $CFG;
  36
  37     if (empty($CFG->xsendfile)) {
  38         return false;
  39     }
  40
  41     if (!file_exists($filepath)) {
  42         return false;
  43     }
  44
  45     if (headers_sent()) {
  46         return false;
  47     }
  48
  49     $filepath = realpath($filepath);
  50
  51     $localrequestdir = realpath($CFG->localrequestdir);
  52     if (str_contains($filepath, $localrequestdir)) {
  53         // Do not serve files from local request directory using xsendfile.
  54         // They are likely to be removed before xsendfile can serve them.
  55         return false;
  56     }
  57
  58     $aliased = false;
  59     if (!empty($CFG->xsendfilealiases) && is_array($CFG->xsendfilealiases)) {
  60         foreach ($CFG->xsendfilealiases as $alias => $dir) {
  61             $dir = realpath($dir);
  62             if ($dir === false) {
  63                 continue;
  64             }
  65             if (substr($dir, -1) !== DIRECTORY_SEPARATOR) {
  66                 // Add trailing dir separator.
  67                 $dir .= DIRECTORY_SEPARATOR;
  68             }
  69             if (str_starts_with($filepath, $dir)) {
  70                 $filepath = $alias . substr($filepath, strlen($dir));
  71                 $aliased = true;
  72                 break;
  73             }
  74         }
  75     }
  76
  77     if ($CFG->xsendfile === 'X-LIGHTTPD-send-file') {
  78         // Version 1.4.40 and earlier do not support byte serving.
  79         // See http://redmine.lighttpd.net/projects/lighttpd/wiki/X-LIGHTTPD-send-file for more information.
  80         header('Accept-Ranges: none');
  81     } else if ($CFG->xsendfile === 'X-Accel-Redirect') {
  82         // Nginx requires paths relative to aliases, you need to specify them in config.php
  83         // See http://wiki.nginx.org/XSendfile for more information.
  84         if (!$aliased) {
  85             return false;
  86         }
  87     }
  88
  89     header("$CFG->xsendfile: $filepath");
  90
  91     return true;
  92 }