feat: Add allowed_view_extensions config node

Signed-off-by: Kostiantyn Miakshyn <[email protected]>

apps/dav/lib/DAV/ViewOnlyPlugin.php

@@ -14,6 +14,7 @@
 use OCP\Files\Folder;
 use OCP\Files\NotFoundException;
 use OCP\Files\Storage\ISharedStorage;
+use OCP\IConfig;
 use Sabre\DAV\Exception\NotFound;
 use Sabre\DAV\Server;
 use Sabre\DAV\ServerPlugin;
@@ -27,6 +28,7 @@ class ViewOnlyPlugin extends ServerPlugin {
 
 	public function __construct(
 		private ?Folder $userFolder,
+		private IConfig $config,
 	) {
 	}
 
@@ -92,6 +94,11 @@ public function checkViewOnly(RequestInterface $request): bool {
 				return true;
 			}
 
+			$allowedFileExtensions = $this->config->getSystemValue('allowed_view_extensions', []);
+			if ($allowedFileExtensions && in_array($node->getExtension(), $allowedFileExtensions, true)) {
+				return true;
+			}
+
 			// Check if read-only and on whether permission can download is both set and disabled.
 			$canDownload = $attributes->getAttribute('permissions', 'download');
 			if ($canDownload !== null && !$canDownload) {

apps/dav/lib/Server.php

@@ -253,6 +253,7 @@ public function __construct(
 			// Allow view-only plugin for webdav requests
 			$this->server->addPlugin(new ViewOnlyPlugin(
 				\OC::$server->getUserFolder(),
+				\OCP\Server::get(IConfig::class),
 			));
 
 			// custom properties plugin must be the last one