diff options
Diffstat (limited to 'apps/dav/lib/CalDAV/WebcalCaching/RefreshWebcalService.php')
| -rw-r--r-- | apps/dav/lib/CalDAV/WebcalCaching/RefreshWebcalService.php | 416 |
1 files changed, 416 insertions, 0 deletions
diff --git a/apps/dav/lib/CalDAV/WebcalCaching/RefreshWebcalService.php b/apps/dav/lib/CalDAV/WebcalCaching/RefreshWebcalService.php new file mode 100644 index 00000000000..beab0271d8f --- /dev/null +++ b/apps/dav/lib/CalDAV/WebcalCaching/RefreshWebcalService.php @@ -0,0 +1,416 @@ +<?php + +declare(strict_types=1); + +/** + * @copyright Copyright (c) 2020, Thomas Citharel <nextcloud@tcit.fr> + * + * @author Georg Ehrke <oc.list@georgehrke.com> + * @author Roeland Jago Douma <roeland@famdouma.nl> + * @author Thomas Citharel <nextcloud@tcit.fr> + * + * @license GNU AGPL version 3 or any later version + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU Affero General Public License as + * published by the Free Software Foundation, either version 3 of the + * License, or (at your option) any later version. + * + * 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 + * along with this program. If not, see <http://www.gnu.org/licenses/>. + * + */ + +namespace OCA\DAV\CalDAV\WebcalCaching; + +use Exception; +use GuzzleHttp\HandlerStack; +use GuzzleHttp\Middleware; +use OCA\DAV\CalDAV\CalDavBackend; +use OCP\AppFramework\Utility\ITimeFactory; +use OCP\Http\Client\IClientService; +use OCP\IConfig; +use OCP\ILogger; +use Psr\Http\Message\RequestInterface; +use Psr\Http\Message\ResponseInterface; +use Sabre\DAV\Exception\BadRequest; +use Sabre\DAV\PropPatch; +use Sabre\DAV\Xml\Property\Href; +use Sabre\VObject\Component; +use Sabre\VObject\DateTimeParser; +use Sabre\VObject\InvalidDataException; +use Sabre\VObject\ParseException; +use Sabre\VObject\Reader; +use Sabre\VObject\Splitter\ICalendar; +use function count; + +class RefreshWebcalService { + + /** @var CalDavBackend */ + private $calDavBackend; + + /** @var IClientService */ + private $clientService; + + /** @var IConfig */ + private $config; + + /** @var ILogger */ + private $logger; + + public const REFRESH_RATE = '{http://apple.com/ns/ical/}refreshrate'; + public const STRIP_ALARMS = '{http://calendarserver.org/ns/}subscribed-strip-alarms'; + public const STRIP_ATTACHMENTS = '{http://calendarserver.org/ns/}subscribed-strip-attachments'; + public const STRIP_TODOS = '{http://calendarserver.org/ns/}subscribed-strip-todos'; + + /** + * RefreshWebcalJob constructor. + * + * @param CalDavBackend $calDavBackend + * @param IClientService $clientService + * @param IConfig $config + * @param ILogger $logger + */ + public function __construct(CalDavBackend $calDavBackend, IClientService $clientService, IConfig $config, ILogger $logger) { + $this->calDavBackend = $calDavBackend; + $this->clientService = $clientService; + $this->config = $config; + $this->logger = $logger; + } + + /** + * @param string $principalUri + * @param string $uri + */ + public function refreshSubscription(string $principalUri, string $uri) { + $subscription = $this->getSubscription($principalUri, $uri); + $mutations = []; + if (!$subscription) { + return; + } + + $webcalData = $this->queryWebcalFeed($subscription, $mutations); + if (!$webcalData) { + return; + } + + $stripTodos = ($subscription[self::STRIP_TODOS] ?? 1) === 1; + $stripAlarms = ($subscription[self::STRIP_ALARMS] ?? 1) === 1; + $stripAttachments = ($subscription[self::STRIP_ATTACHMENTS] ?? 1) === 1; + + try { + $splitter = new ICalendar($webcalData, Reader::OPTION_FORGIVING); + + // we wait with deleting all outdated events till we parsed the new ones + // in case the new calendar is broken and `new ICalendar` throws a ParseException + // the user will still see the old data + $this->calDavBackend->purgeAllCachedEventsForSubscription($subscription['id']); + + while ($vObject = $splitter->getNext()) { + /** @var Component $vObject */ + $uid = null; + $compName = null; + + foreach ($vObject->getComponents() as $component) { + if ($component->name === 'VTIMEZONE') { + continue; + } + + $uid = $component->{'UID'}->getValue(); + $compName = $component->name; + + if ($stripAlarms) { + unset($component->{'VALARM'}); + } + if ($stripAttachments) { + unset($component->{'ATTACH'}); + } + } + + if ($stripTodos && $compName === 'VTODO') { + continue; + } + + $uri = $uid . '.ics'; + $calendarData = $vObject->serialize(); + try { + $this->calDavBackend->createCalendarObject($subscription['id'], $uri, $calendarData, CalDavBackend::CALENDAR_TYPE_SUBSCRIPTION); + } catch(BadRequest $ex) { + $this->logger->logException($ex); + } + } + + $newRefreshRate = $this->checkWebcalDataForRefreshRate($subscription, $webcalData); + if ($newRefreshRate) { + $mutations[self::REFRESH_RATE] = $newRefreshRate; + } + + $this->updateSubscription($subscription, $mutations); + } catch(ParseException $ex) { + $subscriptionId = $subscription['id']; + + $this->logger->logException($ex); + $this->logger->warning("Subscription $subscriptionId could not be refreshed due to a parsing error"); + } + } + + /** + * loads subscription from backend + * + * @param string $principalUri + * @param string $uri + * @return array|null + */ + public function getSubscription(string $principalUri, string $uri) { + $subscriptions = array_values(array_filter( + $this->calDavBackend->getSubscriptionsForUser($principalUri), + function($sub) use ($uri) { + return $sub['uri'] === $uri; + } + )); + + if (count($subscriptions) === 0) { + return null; + } + + return $subscriptions[0]; + } + + /** + * gets webcal feed from remote server + * + * @param array $subscription + * @param array &$mutations + * @return null|string + */ + private function queryWebcalFeed(array $subscription, array &$mutations) { + $client = $this->clientService->newClient(); + + $didBreak301Chain = false; + $latestLocation = null; + + $handlerStack = HandlerStack::create(); + $handlerStack->push(Middleware::mapRequest(function (RequestInterface $request) { + return $request + ->withHeader('Accept', 'text/calendar, application/calendar+json, application/calendar+xml') + ->withHeader('User-Agent', 'Nextcloud Webcal Crawler'); + })); + $handlerStack->push(Middleware::mapResponse(function(ResponseInterface $response) use (&$didBreak301Chain, &$latestLocation) { + if (!$didBreak301Chain) { + if ($response->getStatusCode() !== 301) { + $didBreak301Chain = true; + } else { + $latestLocation = $response->getHeader('Location'); + } + } + return $response; + })); + + $allowLocalAccess = $this->config->getAppValue('dav', 'webcalAllowLocalAccess', 'no'); + $subscriptionId = $subscription['id']; + $url = $this->cleanURL($subscription['source']); + if ($url === null) { + return null; + } + + if ($allowLocalAccess !== 'yes') { + $host = strtolower(parse_url($url, PHP_URL_HOST)); + // remove brackets from IPv6 addresses + if (strpos($host, '[') === 0 && substr($host, -1) === ']') { + $host = substr($host, 1, -1); + } + + // Disallow localhost and local network + if ($host === 'localhost' || substr($host, -6) === '.local' || substr($host, -10) === '.localhost') { + $this->logger->warning("Subscription $subscriptionId was not refreshed because it violates local access rules"); + return null; + } + + // Disallow hostname only + if (substr_count($host, '.') === 0) { + $this->logger->warning("Subscription $subscriptionId was not refreshed because it violates local access rules"); + return null; + } + + if ((bool)filter_var($host, FILTER_VALIDATE_IP) && !filter_var($host, FILTER_VALIDATE_IP, FILTER_FLAG_NO_PRIV_RANGE | FILTER_FLAG_NO_RES_RANGE)) { + $this->logger->warning("Subscription $subscriptionId was not refreshed because it violates local access rules"); + return null; + } + + // Also check for IPv6 IPv4 nesting, because that's not covered by filter_var + if ((bool)filter_var($host, FILTER_VALIDATE_IP, FILTER_FLAG_IPV6) && substr_count($host, '.') > 0) { + $delimiter = strrpos($host, ':'); // Get last colon + $ipv4Address = substr($host, $delimiter + 1); + + if (!filter_var($ipv4Address, FILTER_VALIDATE_IP, FILTER_FLAG_NO_PRIV_RANGE | FILTER_FLAG_NO_RES_RANGE)) { + $this->logger->warning("Subscription $subscriptionId was not refreshed because it violates local access rules"); + return null; + } + } + } + + try { + $params = [ + 'allow_redirects' => [ + 'redirects' => 10 + ], + 'handler' => $handlerStack, + ]; + + $user = parse_url($subscription['source'], PHP_URL_USER); + $pass = parse_url($subscription['source'], PHP_URL_PASS); + if ($user !== null && $pass !== null) { + $params['auth'] = [$user, $pass]; + } + + $response = $client->get($url, $params); + $body = $response->getBody(); + + if ($latestLocation) { + $mutations['{http://calendarserver.org/ns/}source'] = new Href($latestLocation); + } + + $contentType = $response->getHeader('Content-Type'); + $contentType = explode(';', $contentType, 2)[0]; + switch($contentType) { + case 'application/calendar+json': + try { + $jCalendar = Reader::readJson($body, Reader::OPTION_FORGIVING); + } catch(Exception $ex) { + // In case of a parsing error return null + $this->logger->debug("Subscription $subscriptionId could not be parsed"); + return null; + } + return $jCalendar->serialize(); + + case 'application/calendar+xml': + try { + $xCalendar = Reader::readXML($body); + } catch(Exception $ex) { + // In case of a parsing error return null + $this->logger->debug("Subscription $subscriptionId could not be parsed"); + return null; + } + return $xCalendar->serialize(); + + case 'text/calendar': + default: + try { + $vCalendar = Reader::read($body); + } catch(Exception $ex) { + // In case of a parsing error return null + $this->logger->debug("Subscription $subscriptionId could not be parsed"); + return null; + } + return $vCalendar->serialize(); + } + } catch(Exception $ex) { + $this->logger->logException($ex); + $this->logger->warning("Subscription $subscriptionId could not be refreshed due to a network error"); + + return null; + } + } + + /** + * check if: + * - current subscription stores a refreshrate + * - the webcal feed suggests a refreshrate + * - return suggested refreshrate if user didn't set a custom one + * + * @param array $subscription + * @param string $webcalData + * @return string|null + */ + private function checkWebcalDataForRefreshRate($subscription, $webcalData) { + // if there is no refreshrate stored in the database, check the webcal feed + // whether it suggests any refresh rate and store that in the database + if (isset($subscription[self::REFRESH_RATE]) && $subscription[self::REFRESH_RATE] !== null) { + return null; + } + + /** @var Component\VCalendar $vCalendar */ + $vCalendar = Reader::read($webcalData); + + $newRefreshRate = null; + if (isset($vCalendar->{'X-PUBLISHED-TTL'})) { + $newRefreshRate = $vCalendar->{'X-PUBLISHED-TTL'}->getValue(); + } + if (isset($vCalendar->{'REFRESH-INTERVAL'})) { + $newRefreshRate = $vCalendar->{'REFRESH-INTERVAL'}->getValue(); + } + + if (!$newRefreshRate) { + return null; + } + + // check if new refresh rate is even valid + try { + DateTimeParser::parseDuration($newRefreshRate); + } catch(InvalidDataException $ex) { + return null; + } + + return $newRefreshRate; + } + + /** + * update subscription stored in database + * used to set: + * - refreshrate + * - source + * + * @param array $subscription + * @param array $mutations + */ + private function updateSubscription(array $subscription, array $mutations) { + if (empty($mutations)) { + return; + } + + $propPatch = new PropPatch($mutations); + $this->calDavBackend->updateSubscription($subscription['id'], $propPatch); + $propPatch->commit(); + } + + /** + * This method will strip authentication information and replace the + * 'webcal' or 'webcals' protocol scheme + * + * @param string $url + * @return string|null + */ + private function cleanURL(string $url) { + $parsed = parse_url($url); + if ($parsed === false) { + return null; + } + + if (isset($parsed['scheme']) && $parsed['scheme'] === 'http') { + $scheme = 'http'; + } else { + $scheme = 'https'; + } + + $host = $parsed['host'] ?? ''; + $port = isset($parsed['port']) ? ':' . $parsed['port'] : ''; + $path = $parsed['path'] ?? ''; + $query = isset($parsed['query']) ? '?' . $parsed['query'] : ''; + $fragment = isset($parsed['fragment']) ? '#' . $parsed['fragment'] : ''; + + $cleanURL = "$scheme://$host$port$path$query$fragment"; + // parse_url is giving some weird results if no url and no :// is given, + // so let's test the url again + $parsedClean = parse_url($cleanURL); + if ($parsedClean === false || !isset($parsedClean['host'])) { + return null; + } + + return $cleanURL; + } +} |