file.php

   1 <?php // $Id$
   2       // This script fetches files from the dataroot directory
   3       //
   4       // You should use the get_file_url() function, available in lib/filelib.php, to link to file.php.
   5       // This ensures proper formatting and offers useful options.
   6       //
   7       // Syntax:      file.php/courseid/dir/dir/dir/filename.ext
   8       //              file.php/courseid/dir/dir/dir/filename.ext?forcedownload=1 (download instead of inline)
   9       //              file.php/courseid/dir (returns index.html from dir)
  10       // Workaround:  file.php?file=/courseid/dir/dir/dir/filename.ext
  11       // Test:        file.php/testslasharguments
  12
  13
  14       //TODO: Blog attachments do not have access control implemented - anybody can read them!
  15       //      It might be better to move the code to separate file because the access
  16       //      control is quite complex - see bolg/index.php
  17
  18     require_once('config.php');
  19     require_once('lib/filelib.php');
  20
  21     if (!isset($CFG->filelifetime)) {
  22         $lifetime = 86400;     // Seconds for files to remain in caches
  23     } else {
  24         $lifetime = $CFG->filelifetime;
  25     }
  26
  27     // disable moodle specific debug messages
  28     disable_debugging();
  29
  30     $relativepath = get_file_argument('file.php');
  31     $forcedownload = optional_param('forcedownload', 0, PARAM_BOOL);
  32
  33     // relative path must start with '/', because of backup/restore!!!
  34     if (!$relativepath) {
  35         error('No valid arguments supplied or incorrect server configuration');
  36     } else if ($relativepath{0} != '/') {
  37         error('No valid arguments supplied, path does not start with slash!');
  38     }
  39
  40     $pathname = $CFG->dataroot.$relativepath;
  41
  42     // extract relative path components
  43     $args = explode('/', trim($relativepath, '/'));
  44     if (count($args) == 0) { // always at least courseid, may search for index.html in course root
  45         error('No valid arguments supplied');
  46     }
  47
  48     // security: limit access to existing course subdirectories
  49     if (($args[0]!='blog') and (!$course = get_record_sql("SELECT * FROM {$CFG->prefix}course WHERE id='".(int)$args[0]."'"))) {
  50         error('Invalid course ID');
  51     }
  52
  53     // security: prevent access to "000" or "1 something" directories
  54     // hack for blogs, needs proper security check too
  55     if (($args[0] != 'blog') and ($args[0] != $course->id)) {
  56         error('Invalid course ID');
  57     }
  58
  59     // security: login to course if necessary
  60     // Note: file.php always calls require_login() with $setwantsurltome=false
  61     //       in order to avoid messing redirects. MDL-14495
  62     if ($args[0] == 'blog') {
  63         if (empty($CFG->bloglevel)) {
  64             error('Blogging is disabled!');
  65         } else if ($CFG->bloglevel < BLOG_GLOBAL_LEVEL) {
  66             require_login(0, true, null, false);
  67         } else if ($CFG->forcelogin) {
  68             require_login(0, true, null, false);
  69         }
  70     } else if ($course->id != SITEID) {
  71         require_login($course->id, true, null, false);
  72     } else if ($CFG->forcelogin) {
  73         if (!empty($CFG->sitepolicy)
  74             and ($CFG->sitepolicy == $CFG->wwwroot.'/file.php'.$relativepath
  75                  or $CFG->sitepolicy == $CFG->wwwroot.'/file.php?file='.$relativepath)) {
  76             //do not require login for policy file
  77         } else {
  78             require_login(0, true, null, false);
  79         }
  80     }
  81
  82     // security: only editing teachers can access backups
  83     if ((count($args) >= 2) and (strtolower($args[1]) == 'backupdata')) {
  84         if (!has_capability('moodle/site:backup', get_context_instance(CONTEXT_COURSE, $course->id))) {
  85             error('Access not allowed');
  86         } else {
  87             $lifetime = 0; //disable browser caching for backups
  88         }
  89     }
  90
  91     if (is_dir($pathname)) {
  92         if (file_exists($pathname.'/index.html')) {
  93             $pathname = rtrim($pathname, '/').'/index.html';
  94             $args[] = 'index.html';
  95         } else if (file_exists($pathname.'/index.htm')) {
  96             $pathname = rtrim($pathname, '/').'/index.htm';
  97             $args[] = 'index.htm';
  98         } else if (file_exists($pathname.'/Default.htm')) {
  99             $pathname = rtrim($pathname, '/').'/Default.htm';
 100             $args[] = 'Default.htm';
 101         } else {
 102             // security: do not return directory node!
 103             not_found($course->id);
 104         }
 105     }
 106
 107     // security: teachers can view all assignments, students only their own
 108     if ((count($args) >= 3)
 109         and (strtolower($args[1]) == 'moddata')
 110         and (strtolower($args[2]) == 'assignment')) {
 111
 112         $lifetime = 0;  // do not cache assignments, students may reupload them
 113         if ($args[4] == $USER->id) {
 114             //can view own assignemnt submissions
 115         } else {
 116             $instance = (int)$args[3];
 117             if (!$cm = get_coursemodule_from_instance('assignment', $instance, $course->id)) {
 118                 not_found($course->id);
 119             }
 120             if (!has_capability('mod/assignment:grade', get_context_instance(CONTEXT_MODULE, $cm->id))) {
 121                 error('Access not allowed');
 122             }
 123         }
 124     }
 125
 126     // security: force download of all attachments submitted by students
 127     if (count($args) >= 3 and strtolower($args[1]) === 'moddata') {
 128         $mod = clean_param($args[2], PARAM_SAFEDIR);
 129         if (file_exists("$CFG->dirroot/mod/$mod/lib.php")) {
 130             if (!$forcedownload) {
 131                 require_once("$CFG->dirroot/mod/$mod/lib.php");
 132                 $trustedfunction = $mod.'_is_moddata_trusted';
 133                 if (function_exists($trustedfunction)) {
 134                     // force download of all attachments that are not trusted
 135                     $forcedownload = !$trustedfunction();
 136                 } else {
 137                     $forcedownload = 1;
 138                 }
 139             }
 140         } else {
 141             // module is not installed - better not serve file at all
 142             not_found($course->id);
 143         }
 144     }
 145     if ($args[0] == 'blog') {
 146         $forcedownload  = 1; // force download of all attachments
 147     }
 148
 149     // security: some protection of hidden resource files
 150     // warning: it may break backwards compatibility
 151     if ((!empty($CFG->preventaccesstohiddenfiles))
 152         and (count($args) >= 2)
 153         and (!(strtolower($args[1]) == 'moddata' and strtolower($args[2]) != 'resource')) // do not block files from other modules!
 154         and (!has_capability('moodle/course:viewhiddenactivities', get_context_instance(CONTEXT_COURSE, $course->id)))) {
 155
 156         $rargs = $args;
 157         array_shift($rargs);
 158         $reference = implode('/', $rargs);
 159
 160         $sql = "SELECT COUNT(r.id) " .
 161                  "FROM {$CFG->prefix}resource r, " .
 162                       "{$CFG->prefix}course_modules cm, " .
 163                       "{$CFG->prefix}modules m " .
 164                  "WHERE r.course    = '{$course->id}' " .
 165                    "AND m.name      = 'resource' " .
 166                    "AND cm.module   = m.id " .
 167                    "AND cm.instance = r.id " .
 168                    "AND cm.visible  = 0 " .
 169                    "AND r.type      = 'file' " .
 170                    "AND r.reference = '{$reference}'";
 171         if (count_records_sql($sql)) {
 172            error('Access not allowed');
 173         }
 174     }
 175
 176     // check that file exists
 177     if (!file_exists($pathname)) {
 178         not_found($course->id);
 179     }
 180
 181     // ========================================
 182     // finally send the file
 183     // ========================================
 184     session_write_close(); // unlock session during fileserving
 185     $filename = $args[count($args)-1];
 186     send_file($pathname, $filename, $lifetime, $CFG->filteruploadedfiles, false, $forcedownload);
 187
 188     function not_found($courseid) {
 189         global $CFG;
 190         header('HTTP/1.0 404 not found');
 191         print_error('filenotfound', 'error', $CFG->wwwroot.'/course/view.php?id='.$courseid); //this is not displayed on IIS??
 192     }
 193 ?>