owncloud/core

<?php
/**
 * @author Thomas Müller <thomas.mueller@tmit.eu>
 *
 * @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 OCA\DAV\DAV\Sharing;

use OCA\DAV\Connector\Sabre\Auth;
use OCA\DAV\DAV\Sharing\Xml\Invite;
use OCP\IRequest;
use Sabre\DAV\Exception\NotFound;
use Sabre\DAV\INode;
use Sabre\DAV\PropFind;
use Sabre\DAV\Server;
use Sabre\DAV\ServerPlugin;
use Sabre\HTTP\RequestInterface;
use Sabre\HTTP\ResponseInterface;

class Plugin extends ServerPlugin {
    public const NS_OWNCLOUD = 'http://owncloud.org/ns';

    /** @var Auth */
    private $auth;

    /** @var IRequest */
    private $request;

    /**
     * Plugin constructor.
     *
     * @param Auth $authBackEnd
     * @param IRequest $request
     */
    public function __construct(Auth $authBackEnd, IRequest $request) {
        $this->auth = $authBackEnd;
        $this->request = $request;
    }

    /**
     * Reference to SabreDAV server object.
     *
     * @var \Sabre\DAV\Server
     */
    protected $server;

    /**
     * This method should return a list of server-features.
     *
     * This is for example 'versioning' and is added to the DAV: header
     * in an OPTIONS response.
     *
     * @return string[]
     */
    public function getFeatures() {
        return ['oc-resource-sharing'];
    }

    /**
     * Returns a plugin name.
     *
     * Using this name other plugins will be able to access other plugins
     * using Sabre\DAV\Server::getPlugin
     *
     * @return string
     */
    public function getPluginName() {
        return 'oc-resource-sharing';
    }

    /**
     * This initializes the plugin.
     *
     * This function is called by Sabre\DAV\Server, after
     * addPlugin is called.
     *
     * This method should set up the required event subscriptions.
     *
     * @param Server $server
     * @return void
     */
    public function initialize(Server $server) {
        $this->server = $server;
        $this->server->xml->elementMap['{' . Plugin::NS_OWNCLOUD . '}share'] = 'OCA\\DAV\\DAV\\Sharing\\Xml\\ShareRequest';
        $this->server->xml->elementMap['{' . Plugin::NS_OWNCLOUD . '}invite'] = 'OCA\\DAV\\DAV\\Sharing\\Xml\\Invite';

        $this->server->on('method:POST', [$this, 'httpPost']);
        $this->server->on('propFind', [$this, 'propFind']);
    }

    /**
     * We intercept this to handle POST requests on a dav resource.
     *
     * @param RequestInterface $request
     * @param ResponseInterface $response
     * @return null|false
     */
    public function httpPost(RequestInterface $request, ResponseInterface $response) {
        $path = $request->getPath();

        // Only handling xml
        $contentType = $request->getHeader('Content-Type');
        if (\strpos($contentType, 'application/xml') === false && \strpos($contentType, 'text/xml') === false) {
            return;
        }

        // Making sure the node exists
        try {
            $node = $this->server->tree->getNodeForPath($path);
        } catch (NotFound $e) {
            return;
        }

        $requestBody = $request->getBodyAsString();

        // If this request handler could not deal with this POST request, it
        // will return 'null' and other plugins get a chance to handle the
        // request.
        //
        // However, we already requested the full body. This is a problem,
        // because a body can only be read once. This is why we preemptively
        // re-populated the request body with the existing data.
        $request->setBody($requestBody);

        $message = $this->server->xml->parse($requestBody, $request->getUrl(), $documentType);

        switch ($documentType) {
            // Dealing with the 'share' document, which modified invitees on a
            // calendar.
            case '{' . self::NS_OWNCLOUD . '}share':

                // We can only deal with IShareableCalendar objects
                if (!$node instanceof IShareable) {
                    return;
                }

                $this->server->transactionType = 'post-oc-resource-share';

                // Getting ACL info
                $acl = $this->server->getPlugin('acl');

                // If there's no ACL support, we allow everything
                if ($acl) {
                    /** @var \Sabre\DAVACL\Plugin $acl */
                    '@phan-var \Sabre\DAVACL\Plugin $acl';
                    $acl->checkPrivileges($path, '{DAV:}write');
                }

                $node->updateShares($message->set, $message->remove);

                $response->setStatus(200);
                // Adding this because sending a response body may cause issues,
                // and I wanted some type of indicator the response was handled.
                $response->setHeader('X-Sabre-Status', 'everything-went-well');

                // Breaking the event chain
                return false;
        }
    }

    /**
     * This event is triggered when properties are requested for a certain
     * node.
     *
     * This allows us to inject any properties early.
     *
     * @param PropFind $propFind
     * @param INode $node
     * @return void
     */
    public function propFind(PropFind $propFind, INode $node) {
        if ($node instanceof IShareable) {
            $propFind->handle('{' . Plugin::NS_OWNCLOUD . '}invite', function () use ($node) {
                return new Invite(
                    $node->getShares()
                );
            });
        }
    }
}