owncloud/core

<?php
/**
 * @author Vincent Petry <pvince81@owncloud.com>
 * @author Patrick Jahns <github@patrickjahns.de>
 *
 * @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\Connector\Sabre;

use Sabre\DAV\Exception\BadRequest;
use Sabre\DAV\ServerPlugin;
use Sabre\HTTP\RequestInterface;
use Sabre\HTTP\ResponseInterface;

/**
 * Automatically renames a file if the target already exists,
 * if the OC-Autorename header is set.
 */
class AutorenamePlugin extends ServerPlugin {
    /**
     * Reference to main server object
     *
     * @var Server
     */
    private $server;

    /**
     * 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 \Sabre\DAV\Server $server
     * @return void
     */
    public function initialize(\Sabre\DAV\Server $server) {
        $this->server = $server;
        $this->server->on('method:PUT', [$this, 'handlePut'], 1);
    }

    /**
     * @param RequestInterface $request
     * @param ResponseInterface $response
     * @return bool|void
     * @throws \Sabre\DAV\Exception\BadRequest
     * @throws \Sabre\DAV\Exception\Conflict
     * @throws \Sabre\DAV\Exception\NotFound
     */
    public function handlePut(RequestInterface $request, ResponseInterface $response) {
        if ($request->getHeader('OC-Autorename') !== '1') {
            return;
        }

        $path = $request->getPath();

        // Intercepting Content-Range
        if ($request->getHeader('Content-Range')) {
            /*
               An origin server that allows PUT on a given target resource MUST send
               a 400 (Bad Request) response to a PUT request that contains a
               Content-Range header field.

               Reference: http://tools.ietf.org/html/rfc7231#section-4.3.4
            */
            throw new BadRequest('Content-Range on PUT requests are forbidden.');
        }

        if ($this->server->tree->nodeExists($path)) {
            $node = $this->server->tree->getNodeForPath($path);

            // only continue for file nodes
            if (!($node instanceof File)) {
                return;
            }

            if (!$this->server->tree instanceof ObjectTree) {
                return;
            }

            '@phan-var ObjectTree $this->server->tree';
            $view = $this->server->tree->getView();
            list($nodePath, $nodeName) = \Sabre\Uri\split($node->getPath());
            $newName = \OC_Helper::buildNotExistingFileNameForView($nodePath, $nodeName, $view);

            $body = $request->getBodyAsStream();

            $etag = null;
            if (!$this->server->createFile($nodePath . '/' . $newName, $body, $etag)) {
                // For one reason or another the file was not created.
                return false;
            }

            $response->setHeader('Content-Length', '0');
            if ($etag) {
                $response->setHeader('ETag', $etag);
            }
            $response->setStatus(201);

            // handled
            return false;
        }
    }
}