make LazyFolder::get not load the real folder if we know the path

Signed-off-by: Robin Appelman <robin@icewind.nl>

lib/private/Files/Node/LazyFolder.php

@@ -29,7 +29,9 @@ namespace OC\Files\Node;
 use OC\Files\Utils\PathHelper;
 use OCP\Files\Folder;
 use OCP\Constants;
+use OCP\Files\IRootFolder;
 use OCP\Files\Mount\IMountPoint;
+use OCP\Files\NotPermittedException;
 
 /**
  * Class LazyFolder
@@ -41,23 +43,33 @@ use OCP\Files\Mount\IMountPoint;
  */
 class LazyFolder implements Folder {
 	/** @var \Closure(): Folder */
-	private $folderClosure;
-
-	/** @var LazyFolder | null */
-	protected $folder = null;
-
+	private \Closure $folderClosure;
+	protected ?Folder $folder = null;
+	protected IRootFolder $rootFolder;
 	protected array $data;
 
 	/**
-	 * LazyFolder constructor.
-	 *
+	 * @param IRootFolder $rootFolder
 	 * @param \Closure(): Folder $folderClosure
+	 * @param array $data
 	 */
-	public function __construct(\Closure $folderClosure, array $data = []) {
+	public function __construct(IRootFolder $rootFolder, \Closure $folderClosure, array $data = []) {
+		$this->rootFolder = $rootFolder;
 		$this->folderClosure = $folderClosure;
 		$this->data = $data;
 	}
 
+	protected function getRootFolder(): IRootFolder {
+		return $this->rootFolder;
+	}
+
+	protected function getRealFolder(): Folder {
+		if ($this->folder === null) {
+			$this->folder = call_user_func($this->folderClosure);
+		}
+		return $this->folder;
+	}
+
 	/**
 	 * Magic method to first get the real rootFolder and then
 	 * call $method with $args on it
@@ -67,11 +79,7 @@ class LazyFolder implements Folder {
 	 * @return mixed
 	 */
 	public function __call($method, $args) {
-		if ($this->folder === null) {
-			$this->folder = call_user_func($this->folderClosure);
-		}
-
-		return call_user_func_array([$this->folder, $method], $args);
+		return call_user_func_array([$this->getRealFolder(), $method], $args);
 	}
 
 	/**
@@ -148,7 +156,7 @@ class LazyFolder implements Folder {
 	 * @inheritDoc
 	 */
 	public function get($path) {
-		return $this->__call(__FUNCTION__, func_get_args());
+		return $this->getRootFolder()->get($this->getFullPath($path));
 	}
 
 	/**
@@ -408,9 +416,23 @@ class LazyFolder implements Folder {
 	 * @inheritDoc
 	 */
 	public function getFullPath($path) {
+		if (isset($this->data['path'])) {
+			$path = PathHelper::normalizePath($path);
+			if (!$this->isValidPath($path)) {
+				throw new NotPermittedException('Invalid path "' . $path . '"');
+			}
+			return $this->data['path'] . $path;
+		}
 		return $this->__call(__FUNCTION__, func_get_args());
 	}
 
+	public function isValidPath($path) {
+		if (!str_starts_with($path, '/')) {
+			$path = '/' . $path;
+		}
+		return !(str_contains($path, '/../') || strrchr($path, '/') === '/..');
+	}
+
 	/**
 	 * @inheritDoc
 	 */

lib/private/Files/Node/LazyRoot.php

@@ -33,9 +33,18 @@ use OCP\Files\IRootFolder;
  * @package OC\Files\Node
  */
 class LazyRoot extends LazyFolder implements IRootFolder {
-	/**
-	 * @inheritDoc
-	 */
+	public function __construct(\Closure $folderClosure, array $data = []) {
+		parent::__construct($this, $folderClosure, $data);
+	}
+
+	protected function getRootFolder(): IRootFolder {
+		$folder = $this->getRealFolder();
+		if (!$folder instanceof IRootFolder) {
+			throw new \Exception('Lazy root folder closure didn\'t return a root folder');
+		}
+		return $folder;
+	}
+
 	public function getUserFolder($userId) {
 		return $this->__call(__FUNCTION__, func_get_args());
 	}

lib/private/Files/Node/LazyUserFolder.php

@@ -34,19 +34,17 @@ use OCP\IUser;
 use Psr\Log\LoggerInterface;
 
 class LazyUserFolder extends LazyFolder {
-	private IRootFolder $root;
 	private IUser $user;
 	private string $path;
 	private IMountManager $mountManager;
 
 	public function __construct(IRootFolder $rootFolder, IUser $user, IMountManager $mountManager) {
-		$this->root = $rootFolder;
 		$this->user = $user;
 		$this->mountManager = $mountManager;
 		$this->path = '/' . $user->getUID() . '/files';
-		parent::__construct(function () use ($user): Folder {
+		parent::__construct($rootFolder, function () use ($user): Folder {
 			try {
-				$node = $this->root->get($this->path);
+				$node = $this->getRootFolder()->get($this->path);
 				if ($node instanceof File) {
 					$e = new \RuntimeException();
 					\OCP\Server::get(LoggerInterface::class)->error('User root storage is not a folder: ' . $this->path, [
@@ -56,10 +54,10 @@ class LazyUserFolder extends LazyFolder {
 				}
 				return $node;
 			} catch (NotFoundException $e) {
-				if (!$this->root->nodeExists('/' . $user->getUID())) {
-					$this->root->newFolder('/' . $user->getUID());
+				if (!$this->getRootFolder()->nodeExists('/' . $user->getUID())) {
+					$this->getRootFolder()->newFolder('/' . $user->getUID());
 				}
-				return $this->root->newFolder($this->path);
+				return $this->getRootFolder()->newFolder($this->path);
 			}
 		}, [
 			'path' => $this->path,
@@ -71,7 +69,7 @@ class LazyUserFolder extends LazyFolder {
 	}
 
 	public function get($path) {
-		return $this->root->get('/' . $this->user->getUID() . '/files/' . ltrim($path, '/'));
+		return $this->getRootFolder()->get('/' . $this->user->getUID() . '/files/' . ltrim($path, '/'));
 	}
 
 	/**
@@ -79,7 +77,7 @@ class LazyUserFolder extends LazyFolder {
 	 * @return \OCP\Files\Node[]
 	 */
 	public function getById($id) {
-		return $this->root->getByIdInPath((int)$id, $this->getPath());
+		return $this->getRootFolder()->getByIdInPath((int)$id, $this->getPath());
 	}
 
 	public function getMountPoint() {

lib/private/Files/Node/Node.php

@@ -304,7 +304,7 @@ class Node implements INode {
 			];
 
 			// and create lazy folder with it instead of always querying
-			$this->parent = new LazyFolder(function () use ($newPath) {
+			$this->parent = new LazyFolder($this->root, function () use ($newPath) {
 				return $this->root->get($newPath);
 			}, $parentData);
 		}