Nelson Moller 413907cff3 MDL-48929 repository_filesystem: Valide relative path against realpath
On Windows systems, there could have been a mix of back and forward
slashes, causing the validation of the relative path to fail. Now
we will always get the realpath before comparing.
2015-01-23 17:26:32 +08:00

669 lines
25 KiB
PHP

<?php
// This file is part of Moodle - http://moodle.org/
//
// Moodle is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Moodle is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Moodle. If not, see <http://www.gnu.org/licenses/>.
/**
* This plugin is used to access files on server file system
*
* @since Moodle 2.0
* @package repository_filesystem
* @copyright 2010 Dongsheng Cai {@link http://dongsheng.org}
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
require_once($CFG->dirroot . '/repository/lib.php');
require_once($CFG->libdir . '/filelib.php');
/**
* repository_filesystem class
*
* Create a repository from your local filesystem
* *NOTE* for security issue, we use a fixed repository path
* which is %moodledata%/repository
*
* @package repository
* @copyright 2009 Dongsheng Cai {@link http://dongsheng.org}
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
class repository_filesystem extends repository {
/**
* The subdirectory of the instance.
*
* @var string
*/
protected $subdir;
/**
* Constructor
*
* @param int $repositoryid repository ID
* @param int $context context ID
* @param array $options
*/
public function __construct($repositoryid, $context = SYSCONTEXTID, $options = array()) {
parent::__construct($repositoryid, $context, $options);
$this->subdir = $this->get_option('fs_path');
}
/**
* Get the list of files and directories in that repository.
*
* @param string $path to browse.
* @param string $page page number.
* @return array list of files and folders.
*/
public function get_listing($path = '', $page = '') {
global $OUTPUT;
$list = array();
$list['list'] = array();
$list['manage'] = false;
$list['dynload'] = true;
$list['nologin'] = true;
$list['nosearch'] = true;
$list['path'] = array(
array('name' => get_string('root', 'repository_filesystem'), 'path' => '')
);
$path = trim($path, '/');
if (!$this->is_in_repository($path)) {
// In case of doubt on the path, reset to default.
$path = '';
}
$abspath = rtrim($this->get_rootpath() . $path, '/') . '/';
// Construct the breadcrumb.
$trail = '';
if ($path !== '') {
$parts = explode('/', $path);
if (count($parts) > 1) {
foreach ($parts as $part) {
if (!empty($part)) {
$trail .= '/' . $part;
$list['path'][] = array('name' => $part, 'path' => $trail);
}
}
} else {
$list['path'][] = array('name' => $path, 'path' => $path);
}
}
// Retrieve list of files and directories and sort them.
$fileslist = array();
$dirslist = array();
if ($dh = opendir($abspath)) {
while (($file = readdir($dh)) != false) {
if ($file != '.' and $file != '..') {
if (is_file($abspath . $file)) {
$fileslist[] = $file;
} else {
$dirslist[] = $file;
}
}
}
}
core_collator::asort($fileslist, core_collator::SORT_NATURAL);
core_collator::asort($dirslist, core_collator::SORT_NATURAL);
// Fill the $list['list'].
foreach ($dirslist as $file) {
$list['list'][] = array(
'title' => $file,
'children' => array(),
'datecreated' => filectime($abspath . $file),
'datemodified' => filemtime($abspath . $file),
'thumbnail' => $OUTPUT->pix_url(file_folder_icon(90))->out(false),
'path' => $path . '/' . $file
);
}
foreach ($fileslist as $file) {
$node = array(
'title' => $file,
'source' => $path . '/' . $file,
'size' => filesize($abspath . $file),
'datecreated' => filectime($abspath . $file),
'datemodified' => filemtime($abspath . $file),
'thumbnail' => $OUTPUT->pix_url(file_extension_icon($file, 90))->out(false),
'icon' => $OUTPUT->pix_url(file_extension_icon($file, 24))->out(false)
);
if (file_extension_in_typegroup($file, 'image') && ($imageinfo = @getimagesize($abspath . $file))) {
// This means it is an image and we can return dimensions and try to generate thumbnail/icon.
$token = $node['datemodified'] . $node['size']; // To prevent caching by browser.
$node['realthumbnail'] = $this->get_thumbnail_url($path . '/' . $file, 'thumb', $token)->out(false);
$node['realicon'] = $this->get_thumbnail_url($path . '/' . $file, 'icon', $token)->out(false);
$node['image_width'] = $imageinfo[0];
$node['image_height'] = $imageinfo[1];
}
$list['list'][] = $node;
}
$list['list'] = array_filter($list['list'], array($this, 'filter'));
return $list;
}
/**
* To check whether the user is logged in.
*
* @return bool
*/
public function check_login() {
return true;
}
/**
* Show the login screen, if required.
*
* @return string
*/
public function print_login() {
return true;
}
/**
* Is it possible to do a global search?
*
* @return bool
*/
public function global_search() {
return false;
}
/**
* Return file path.
* @return array
*/
public function get_file($file, $title = '') {
global $CFG;
$file = ltrim($file, '/');
if (!$this->is_in_repository($file)) {
throw new repository_exception('Invalid file requested.');
}
$file = $this->get_rootpath() . $file;
// This is a hack to prevent move_to_file deleting files in local repository.
$CFG->repository_no_delete = true;
return array('path' => $file, 'url' => '');
}
/**
* Return the source information
*
* @param stdClass $filepath
* @return string|null
*/
public function get_file_source_info($filepath) {
return $filepath;
}
/**
* Logout from repository instance
*
* @return string
*/
public function logout() {
return true;
}
/**
* Return names of the instance options.
*
* @return array
*/
public static function get_instance_option_names() {
return array('fs_path', 'relativefiles');
}
/**
* Save settings for repository instance
*
* @param array $options settings
* @return bool
*/
public function set_option($options = array()) {
$options['fs_path'] = clean_param($options['fs_path'], PARAM_PATH);
$options['relativefiles'] = clean_param($options['relativefiles'], PARAM_INT);
$ret = parent::set_option($options);
return $ret;
}
/**
* Edit/Create Instance Settings Moodle form
*
* @param moodleform $mform Moodle form (passed by reference)
*/
public static function instance_config_form($mform) {
global $CFG;
if (has_capability('moodle/site:config', context_system::instance())) {
$path = $CFG->dataroot . '/repository/';
if (!is_dir($path)) {
mkdir($path, $CFG->directorypermissions, true);
}
if ($handle = opendir($path)) {
$fieldname = get_string('path', 'repository_filesystem');
$choices = array();
while (false !== ($file = readdir($handle))) {
if (is_dir($path . $file) && $file != '.' && $file != '..') {
$choices[$file] = $file;
$fieldname = '';
}
}
if (empty($choices)) {
$mform->addElement('static', '', '', get_string('nosubdir', 'repository_filesystem', $path));
$mform->addElement('hidden', 'fs_path', '');
$mform->setType('fs_path', PARAM_PATH);
} else {
$mform->addElement('select', 'fs_path', $fieldname, $choices);
$mform->addElement('static', null, '', get_string('information', 'repository_filesystem', $path));
}
closedir($handle);
}
$mform->addElement('checkbox', 'relativefiles', get_string('relativefiles', 'repository_filesystem'),
get_string('relativefiles_desc', 'repository_filesystem'));
$mform->setType('relativefiles', PARAM_INT);
} else {
$mform->addElement('static', null, '', get_string('nopermissions', 'error', get_string('configplugin',
'repository_filesystem')));
return false;
}
}
/**
* Create an instance for this plug-in
*
* @static
* @param string $type the type of the repository
* @param int $userid the user id
* @param stdClass $context the context
* @param array $params the options for this instance
* @param int $readonly whether to create it readonly or not (defaults to not)
* @return mixed
*/
public static function create($type, $userid, $context, $params, $readonly=0) {
if (has_capability('moodle/site:config', context_system::instance())) {
return parent::create($type, $userid, $context, $params, $readonly);
} else {
require_capability('moodle/site:config', context_system::instance());
return false;
}
}
/**
* Validate repository plugin instance form
*
* @param moodleform $mform moodle form
* @param array $data form data
* @param array $errors errors
* @return array errors
*/
public static function instance_form_validation($mform, $data, $errors) {
$fspath = clean_param(trim($data['fs_path'], '/'), PARAM_PATH);
if (empty($fspath) && !is_numeric($fspath)) {
$errors['fs_path'] = get_string('invalidadminsettingname', 'error', 'fs_path');
}
return $errors;
}
/**
* User cannot use the external link to dropbox
*
* @return int
*/
public function supported_returntypes() {
return FILE_INTERNAL | FILE_REFERENCE;
}
/**
* Return human readable reference information
*
* @param string $reference value of DB field files_reference.reference
* @param int $filestatus status of the file, 0 - ok, 666 - source missing
* @return string
*/
public function get_reference_details($reference, $filestatus = 0) {
$details = $this->get_name().': '.$reference;
if ($filestatus) {
return get_string('lostsource', 'repository', $details);
} else {
return $details;
}
}
public function sync_reference(stored_file $file) {
if ($file->get_referencelastsync() + 60 > time()) {
// Does not cost us much to synchronise within our own filesystem, check every 1 minute.
return false;
}
static $issyncing = false;
if ($issyncing) {
// Avoid infinite recursion when calling $file->get_filesize() and get_contenthash().
return;
}
$filepath = $this->get_rootpath() . ltrim($file->get_reference(), '/');
if ($this->is_in_repository($file->get_reference()) && file_exists($filepath) && is_readable($filepath)) {
$fs = get_file_storage();
$issyncing = true;
if (file_extension_in_typegroup($filepath, 'web_image')) {
$contenthash = sha1_file($filepath);
if ($file->get_contenthash() == $contenthash) {
// File did not change since the last synchronisation.
$filesize = filesize($filepath);
} else {
// Copy file into moodle filepool (used to generate an image thumbnail).
list($contenthash, $filesize, $newfile) = $fs->add_file_to_pool($filepath);
}
} else {
// Update only file size so file will NOT be copied into moodle filepool.
$contenthash = null;
$filesize = filesize($filepath);
}
$issyncing = false;
$file->set_synchronized($contenthash, $filesize);
} else {
$file->set_missingsource();
}
return true;
}
/**
* Repository method to serve the referenced file
*
* @see send_stored_file
*
* @param stored_file $storedfile the file that contains the reference
* @param int $lifetime Number of seconds before the file should expire from caches (null means $CFG->filelifetime)
* @param int $filter 0 (default)=no filtering, 1=all files, 2=html files only
* @param bool $forcedownload If true (default false), forces download of file rather than view in browser/plugin
* @param array $options additional options affecting the file serving
*/
public function send_file($storedfile, $lifetime=null , $filter=0, $forcedownload=false, array $options = null) {
$reference = $storedfile->get_reference();
$file = $this->get_rootpath() . ltrim($reference, '/');
if ($this->is_in_repository($reference) && is_readable($file)) {
$filename = $storedfile->get_filename();
if ($options && isset($options['filename'])) {
$filename = $options['filename'];
}
$dontdie = ($options && isset($options['dontdie']));
send_file($file, $filename, $lifetime , $filter, false, $forcedownload, '', $dontdie);
} else {
send_file_not_found();
}
}
/**
* Is this repository accessing private data?
*
* @return bool
*/
public function contains_private_data() {
return false;
}
/**
* Return the rootpath of this repository instance.
*
* Trim() is a necessary step to ensure that the subdirectory is not '/'.
*
* @return string path
* @throws repository_exception If the subdir is unsafe, or invalid.
*/
public function get_rootpath() {
global $CFG;
$subdir = clean_param(trim($this->subdir, '/'), PARAM_PATH);
$path = $CFG->dataroot . '/repository/' . $this->subdir . '/';
if ((empty($this->subdir) && !is_numeric($this->subdir)) || $subdir != $this->subdir || !is_dir($path)) {
throw new repository_exception('The instance is not properly configured, invalid path.');
}
return $path;
}
/**
* Checks if $path is part of this repository.
*
* Try to prevent $path hacks such as ../ .
*
* We do not use clean_param(, PARAM_PATH) here because it also trims down some
* characters that are allowed, like < > ' . But we do ensure that the directory
* is safe by checking that it starts with $rootpath.
*
* @param string $path relative path to a file or directory in the repo.
* @return boolean false when not.
*/
protected function is_in_repository($path) {
$rootpath = $this->get_rootpath();
if (strpos(realpath($rootpath . $path), realpath($rootpath)) !== 0) {
return false;
}
return true;
}
/**
* Returns url of thumbnail file.
*
* @param string $filepath current path in repository (dir and filename)
* @param string $thumbsize 'thumb' or 'icon'
* @param string $token identifier of the file contents - to prevent browser from caching changed file
* @return moodle_url
*/
protected function get_thumbnail_url($filepath, $thumbsize, $token) {
return moodle_url::make_pluginfile_url($this->context->id, 'repository_filesystem', $thumbsize, $this->id,
'/' . trim($filepath, '/') . '/', $token);
}
/**
* Returns the stored thumbnail file, generates it if not present.
*
* @param string $filepath current path in repository (dir and filename)
* @param string $thumbsize 'thumb' or 'icon'
* @return null|stored_file
*/
public function get_thumbnail($filepath, $thumbsize) {
global $CFG;
$filepath = trim($filepath, '/');
$origfile = $this->get_rootpath() . $filepath;
// As thumbnail filename we use original file content hash.
if (!$this->is_in_repository($filepath) || !($filecontents = @file_get_contents($origfile))) {
// File is not found or is not readable.
return null;
}
$filename = sha1($filecontents);
unset($filecontents);
// Try to get generated thumbnail for this file.
$fs = get_file_storage();
if (!($file = $fs->get_file(SYSCONTEXTID, 'repository_filesystem', $thumbsize, $this->id, '/' . $filepath . '/',
$filename))) {
// Thumbnail not found . Generate and store thumbnail.
require_once($CFG->libdir . '/gdlib.php');
if ($thumbsize === 'thumb') {
$size = 90;
} else {
$size = 24;
}
if (!$data = @generate_image_thumbnail($origfile, $size, $size)) {
// Generation failed.
return null;
}
$record = array(
'contextid' => SYSCONTEXTID,
'component' => 'repository_filesystem',
'filearea' => $thumbsize,
'itemid' => $this->id,
'filepath' => '/' . $filepath . '/',
'filename' => $filename,
);
$file = $fs->create_file_from_string($record, $data);
}
return $file;
}
/**
* Run in cron for particular repository instance. Removes thumbnails for deleted/modified files.
*
* @param stored_file[] $storedfiles
*/
public function remove_obsolete_thumbnails($storedfiles) {
// Group found files by filepath ('filepath' in Moodle file storage is dir+name in filesystem repository).
$files = array();
foreach ($storedfiles as $file) {
if (!isset($files[$file->get_filepath()])) {
$files[$file->get_filepath()] = array();
}
$files[$file->get_filepath()][] = $file;
}
// Loop through all files and make sure the original exists and has the same contenthash.
$deletedcount = 0;
foreach ($files as $filepath => $filesinpath) {
if ($filecontents = @file_get_contents($this->get_rootpath() . trim($filepath, '/'))) {
// The 'filename' in Moodle file storage is contenthash of the file in filesystem repository.
$filename = sha1($filecontents);
foreach ($filesinpath as $file) {
if ($file->get_filename() !== $filename && $file->get_filename() !== '.') {
// Contenthash does not match, this is an old thumbnail.
$deletedcount++;
$file->delete();
}
}
} else {
// Thumbnail exist but file not.
foreach ($filesinpath as $file) {
if ($file->get_filename() !== '.') {
$deletedcount++;
}
$file->delete();
}
}
}
if ($deletedcount) {
mtrace(" instance {$this->id}: deleted $deletedcount thumbnails");
}
}
/**
* Gets a file relative to this file in the repository and sends it to the browser.
*
* @param stored_file $mainfile The main file we are trying to access relative files for.
* @param string $relativepath the relative path to the file we are trying to access.
*/
public function send_relative_file(stored_file $mainfile, $relativepath) {
global $CFG;
// Check if this repository is allowed to use relative linking.
$allowlinks = $this->supports_relative_file();
if (!empty($allowlinks)) {
// Get path to the mainfile.
$mainfilepath = $mainfile->get_source();
// Strip out filename from the path.
$filename = $mainfile->get_filename();
$basepath = strstr($mainfilepath, $filename, true);
$fullrelativefilepath = realpath($this->get_rootpath().$basepath.$relativepath);
// Sanity check to make sure this path is inside this repository and the file exists.
if (strpos($fullrelativefilepath, realpath($this->get_rootpath())) === 0 && file_exists($fullrelativefilepath)) {
send_file($fullrelativefilepath, basename($relativepath), null, 0);
}
}
send_file_not_found();
}
/**
* helper function to check if the repository supports send_relative_file.
*
* @return true|false
*/
public function supports_relative_file() {
return $this->get_option('relativefiles');
}
}
/**
* Generates and sends the thumbnail for an image in filesystem.
*
* @param stdClass $course course object
* @param stdClass $cm course module object
* @param stdClass $context context object
* @param string $filearea file area
* @param array $args extra arguments
* @param bool $forcedownload whether or not force download
* @param array $options additional options affecting the file serving
* @return bool
*/
function repository_filesystem_pluginfile($course, $cm, $context, $filearea, $args, $forcedownload, array $options=array()) {
global $OUTPUT, $CFG;
// Allowed filearea is either thumb or icon - size of the thumbnail.
if ($filearea !== 'thumb' && $filearea !== 'icon') {
return false;
}
// As itemid we pass repository instance id.
$itemid = array_shift($args);
// Filename is some token that we can ignore (used only to make sure browser does not serve cached copy when file is changed).
array_pop($args);
// As filepath we use full filepath (dir+name) of the file in this instance of filesystem repository.
$filepath = implode('/', $args);
// Make sure file exists in the repository and is accessible.
$repo = repository::get_repository_by_id($itemid, $context);
$repo->check_capability();
// Find stored or generated thumbnail.
if (!($file = $repo->get_thumbnail($filepath, $filearea))) {
// Generation failed, redirect to default icon for file extension.
redirect($OUTPUT->pix_url(file_extension_icon($file, 90)));
}
// The thumbnails should not be changing much, but maybe the default lifetime is too long.
$lifetime = $CFG->filelifetime;
if ($lifetime > 60*10) {
$lifetime = 60*10;
}
send_stored_file($file, $lifetime, 0, $forcedownload, $options);
}
/**
* Cron callback for repository_filesystem. Deletes the thumbnails for deleted or changed files.
*/
function repository_filesystem_cron() {
$fs = get_file_storage();
// Find all generated thumbnails and group them in array by itemid (itemid == repository instance id).
$allfiles = array_merge(
$fs->get_area_files(SYSCONTEXTID, 'repository_filesystem', 'thumb'),
$fs->get_area_files(SYSCONTEXTID, 'repository_filesystem', 'icon')
);
$filesbyitem = array();
foreach ($allfiles as $file) {
if (!isset($filesbyitem[$file->get_itemid()])) {
$filesbyitem[$file->get_itemid()] = array();
}
$filesbyitem[$file->get_itemid()][] = $file;
}
// Find all instances of repository_filesystem.
$instances = repository::get_instances(array('type' => 'filesystem'));
// Loop through all itemids of generated thumbnails.
foreach ($filesbyitem as $itemid => $files) {
if (!isset($instances[$itemid]) || !($instances[$itemid] instanceof repository_filesystem)) {
// Instance was deleted.
$fs->delete_area_files(SYSCONTEXTID, 'repository_filesystem', 'thumb', $itemid);
$fs->delete_area_files(SYSCONTEXTID, 'repository_filesystem', 'icon', $itemid);
mtrace(" instance $itemid does not exist: deleted all thumbnails");
} else {
// Instance has some generated thumbnails, check that they are not outdated.
$instances[$itemid]->remove_obsolete_thumbnails($files);
}
}
}