1 files changed, 112 insertions, 0 deletions
diff --git a/apps/dav/lib/Connector/Sabre/AppleQuirksPlugin.php b/apps/dav/lib/Connector/Sabre/AppleQuirksPlugin.php
new file mode 100644
index 00000000000..9cff113140a
--- /dev/null
+++ b/apps/dav/lib/Connector/Sabre/AppleQuirksPlugin.php
@@ -0,0 +1,112 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2023 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+namespace OCA\DAV\Connector\Sabre;
+
+use Sabre\DAV\Server;
+use Sabre\DAV\ServerPlugin;
+use Sabre\HTTP\RequestInterface;
+use Sabre\HTTP\ResponseInterface;
+
+/**
+ * A plugin which tries to work-around peculiarities of the MacOS DAV client
+ * apps. The following problems are addressed:
+ *
+ * - OSX calendar client sends REPORT requests to a random principal
+ *   collection but expects to find all principals (forgot to set
+ *   {DAV:}principal-property-search flag?)
+ */
+class AppleQuirksPlugin extends ServerPlugin {
+
+	/*
+	private const OSX_CALENDAR_AGENT = 'CalendarAgent';
+	private const OSX_DATAACCESSD_AGENT = 'dataaccessd';
+	private const OSX_ACCOUNTSD_AGENT = 'accountsd';
+	private const OSX_CONTACTS_AGENT = 'AddressBookCore';
+	*/
+
+	private const OSX_AGENT_PREFIX = 'macOS';
+
+	/** @var bool */
+	private $isMacOSDavAgent = false;
+
+	/**
+	 * Sets up the plugin.
+	 *
+	 * This method is automatically called by the server class.
+	 *
+	 * @return void
+	 */
+	public function initialize(Server $server) {
+		$server->on('beforeMethod:REPORT', [$this, 'beforeReport'], 0);
+		$server->on('report', [$this, 'report'], 0);
+	}
+
+	/**
+	 * Triggered before any method is handled.
+	 *
+	 * @return void
+	 */
+	public function beforeReport(RequestInterface $request, ResponseInterface $response) {
+		$userAgent = $request->getRawServerValue('HTTP_USER_AGENT') ?? 'unknown';
+		$this->isMacOSDavAgent = $this->isMacOSUserAgent($userAgent);
+	}
+
+	/**
+	 * This method handles HTTP REPORT requests.
+	 *
+	 * @param string $reportName
+	 * @param mixed $report
+	 * @param mixed $path
+	 *
+	 * @return bool
+	 */
+	public function report($reportName, $report, $path) {
+		if ($reportName == '{DAV:}principal-property-search' && $this->isMacOSDavAgent) {
+			/** @var \Sabre\DAVACL\Xml\Request\PrincipalPropertySearchReport $report */
+			$report->applyToPrincipalCollectionSet = true;
+		}
+		return true;
+	}
+
+	/**
+	 * Check whether the given $userAgent string pretends to originate from OSX.
+	 *
+	 * @param string $userAgent
+	 *
+	 * @return bool
+	 */
+	protected function isMacOSUserAgent(string $userAgent):bool {
+		return str_starts_with(self::OSX_AGENT_PREFIX, $userAgent);
+	}
+
+	/**
+	 * Decode the given OSX DAV agent string.
+	 *
+	 * @param string $agent
+	 *
+	 * @return null|array
+	 */
+	protected function decodeMacOSAgentString(string $userAgent):?array {
+		// OSX agent string is like: macOS/13.2.1 (22D68) dataaccessd/1.0
+		if (preg_match('|^' . self::OSX_AGENT_PREFIX . '/([0-9]+)\\.([0-9]+)\\.([0-9]+)\s+\((\w+)\)\s+([^/]+)/([0-9]+)(?:\\.([0-9]+))?(?:\\.([0-9]+))?$|i', $userAgent, $matches)) {
+			return [
+				'macOSVersion' => [
+					'major' => $matches[1],
+					'minor' => $matches[2],
+					'patch' => $matches[3],
+				],
+				'macOSAgent' => $matches[5],
+				'macOSAgentVersion' => [
+					'major' => $matches[6],
+					'minor' => $matches[7] ?? null,
+					'patch' => $matches[8] ?? null,
+				],
+			];
+		}
+		return null;
+	}
+}