owncloud/core

<?php
/**
 * @author Jörn Friedrich Dreyer <jfd@butonic.de>
 * @author Morris Jobke <hey@morrisjobke.de>
 * @author Robin Appelman <icewind@owncloud.com>
 * @author Robin McCorkell <robin@mccorkell.me.uk>
 * @author Stefan Weil <sw@weilnetz.de>
 * @author Vincent Petry <pvince81@owncloud.com>
 *
 * @copyright Copyright (c) 2018, ownCloud GmbH
 * @license AGPL-3.0
 *
 * This code is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License, version 3,
 * as published by the Free Software Foundation.
 *
 * This program 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 Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License, version 3,
 * along with this program.  If not, see <http://www.gnu.org/licenses/>
 *
 */

namespace OC\Files\Storage\Wrapper;

use OC\Files\Cache\Wrapper\CachePermissionsMask;
use OCP\Constants;

/**
 * Mask the permissions of a storage
 *
 * This can be used to restrict update, create, delete and/or share permissions of a storage
 *
 * Note that the read permissions can't be masked
 */
class PermissionsMask extends Wrapper {
    /**
     * @var int the permissions bits we want to keep
     */
    protected $mask;

    /**
     * @param array $arguments ['storage' => $storage, 'mask' => $mask]
     *
     * $storage: The storage the permissions mask should be applied on
     * $mask: The permission bits that should be kept, a combination of the \OCP\Constant::PERMISSION_ constants
     */
    public function __construct($arguments) {
        parent::__construct($arguments);
        $this->mask = $arguments['mask'];
    }

    private function checkMask($permissions) {
        return ($this->mask & $permissions) === $permissions;
    }

    public function isUpdatable($path) {
        return $this->checkMask(Constants::PERMISSION_UPDATE) and parent::isUpdatable($path);
    }

    public function isCreatable($path) {
        return $this->checkMask(Constants::PERMISSION_CREATE) and parent::isCreatable($path);
    }

    public function isDeletable($path) {
        return $this->checkMask(Constants::PERMISSION_DELETE) and parent::isDeletable($path);
    }

    public function isSharable($path) {
        return $this->checkMask(Constants::PERMISSION_SHARE) and parent::isSharable($path);
    }

    public function getPermissions($path) {
        return $this->storage->getPermissions($path) & $this->mask;
    }

    private function isPartFile($path) {
        return \pathinfo($path, PATHINFO_EXTENSION) === 'part';
    }

    public function rename($path1, $path2) {
        // allow renaming part files
        return ($this->isPartFile($path1) || $this->checkMask(Constants::PERMISSION_UPDATE)) && parent::rename($path1, $path2);
    }

    public function copy($path1, $path2) {
        return $this->checkMask(Constants::PERMISSION_CREATE) and parent::copy($path1, $path2);
    }

    public function touch($path, $mtime = null) {
        $permissions = $this->file_exists($path) ? Constants::PERMISSION_UPDATE : Constants::PERMISSION_CREATE;
        return ($this->isPartFile($path) || $this->checkMask($permissions)) && parent::touch($path, $mtime);
    }

    public function mkdir($path) {
        return $this->checkMask(Constants::PERMISSION_CREATE) and parent::mkdir($path);
    }

    public function rmdir($path) {
        return $this->checkMask(Constants::PERMISSION_DELETE) and parent::rmdir($path);
    }

    public function unlink($path) {
        return ($this->isPartFile($path) || $this->checkMask(Constants::PERMISSION_DELETE)) && parent::unlink($path);
    }

    public function file_put_contents($path, $data) {
        $permissions = $this->file_exists($path) ? Constants::PERMISSION_UPDATE : Constants::PERMISSION_CREATE;
        return ($this->isPartFile($path) || $this->checkMask($permissions)) && parent::file_put_contents($path, $data);
    }

    public function fopen($path, $mode) {
        if ($mode === 'r' or $mode === 'rb') {
            return parent::fopen($path, $mode);
        } else {
            $permissions = $this->file_exists($path) ? Constants::PERMISSION_UPDATE : Constants::PERMISSION_CREATE;
            return ($this->isPartFile($path) || $this->checkMask($permissions)) ? parent::fopen($path, $mode) : false;
        }
    }

    /**
     * get a cache instance for the storage
     *
     * @param string $path
     * @param \OC\Files\Storage\Storage (optional) the storage to pass to the cache
     * @return \OC\Files\Cache\Cache
     */
    public function getCache($path = '', $storage = null) {
        if (!$storage) {
            $storage = $this;
        }
        $sourceCache = parent::getCache($path, $storage);
        return new CachePermissionsMask($sourceCache, $this->mask);
    }
}