From abf0b5332b215631d1da7737b69e21301aaafbae Mon Sep 17 00:00:00 2001
From: Tamino Bauknecht <dev@tb6.eu>
Date: Wed, 15 Nov 2023 20:38:08 +0100
Subject: [PATCH] First draft for metadata-only symlinks

---
 apps/dav/lib/BulkUpload/BulkUploadPlugin.php | 21 ++++++++------------
 apps/dav/lib/Connector/Sabre/FilesPlugin.php | 13 ++++++------
 apps/dav/lib/Upload/ChunkingV2Plugin.php     | 19 +++++++-----------
 lib/public/Files/FileInfo.php                |  4 ++++
 4 files changed, 26 insertions(+), 31 deletions(-)

diff --git a/apps/dav/lib/BulkUpload/BulkUploadPlugin.php b/apps/dav/lib/BulkUpload/BulkUploadPlugin.php
index 471568a107299..f4f25e55dbd8e 100644
--- a/apps/dav/lib/BulkUpload/BulkUploadPlugin.php
+++ b/apps/dav/lib/BulkUpload/BulkUploadPlugin.php
@@ -100,21 +100,16 @@ public function httpPost(RequestInterface $request, ResponseInterface $response)
 				}
 
 				if (isset($headers['oc-file-type']) && $headers['oc-file-type'] == 1) {
-					// TODO: store default value in global location
-					$allowSymlinks = \OC::$server->get(\OC\AllConfig::class)->getSystemValueBool(
-						'localstorage.allowsymlinks', false);
-					if (!$allowSymlinks) {
-						throw new Forbidden("Server does not allow the creation of symlinks!");
-					}
 					$symlinkPath = $headers['x-file-path'];
-					$parentNode = $this->server->tree->getNodeForPath(dirname($symlinkPath));
-					if(!$parentNode instanceof \OCA\DAV\Connector\Sabre\Directory) {
-						throw new Exception("Unable to upload '$symlinkPath' because the remote directory does not support symlink creation!");
-					}
-					$etag = $parentNode->createSymlink(basename($symlinkPath), $content);
-					$writtenFiles[$headers['x-file-path']] = [
+					$newEtag = "'$symlinkPath'->'$content'";
+					$infoData = [
+						'type' => \OC\Files\FileInfo::TYPE_SYMLINK,
+						'etag' => $newEtag,
+					];
+					\OC\Files\Filesystem::getView()->putFileInfo($symlinkPath, $infoData);
+					$writtenFiles[$symlinkPath] = [
 						"error" => false,
-						"etag" => $etag,
+						"etag" => $newEtag,
 					];
 					continue;
 				}
diff --git a/apps/dav/lib/Connector/Sabre/FilesPlugin.php b/apps/dav/lib/Connector/Sabre/FilesPlugin.php
index 3a5b71ec7d76f..ad77f58d16845 100644
--- a/apps/dav/lib/Connector/Sabre/FilesPlugin.php
+++ b/apps/dav/lib/Connector/Sabre/FilesPlugin.php
@@ -236,17 +236,18 @@ public function handleDownloadToken(RequestInterface $request, ResponseInterface
 
 	public function httpGet(RequestInterface $request, ResponseInterface $response) {
 		// only handle symlinks
-		// TODO(taminob): does not work if not in cache (which it is currently not because the path here is /files/root/path/to/symlink (request path) and the path in cache is only /root/files/path/to/symlink (internal path)); to make it work without cache, e.g. \Sabre\DAV\Server::getResourceTypeForNode would have to be extended to handle symlinks
-		$node = $this->tree->getNodeForPath($request->getPath());
-		if (!($node instanceof \OCA\DAV\Connector\Sabre\File)) {
+		$symlinkPath = $request->getPath();
+		$fileInfo = \OC\Files\Filesystem::getView()->getFileInfo($symlinkPath);
+		if (!$fileInfo || $fileInfo->getType() !== \OC\Files\FileInfo::TYPE_SYMLINK) {
 			return;
 		}
-		if ($node->getFileInfo()->getType() !== \OCP\Files\FileInfo::TYPE_SYMLINK) {
-			return;
+		$symlinkTarget = $fileInfo->getMetadata()['symlinkTarget'];
+		if (isset($symlinkTarget)) {
+			throw new NotFound("Symlink has no target!");
 		}
 
 		$response->addHeader('OC-File-Type', '1');
-		$response->setBody($node->readlink());
+		$response->setBody($symlinkTarget);
 		// do not continue processing this request
 		return false;
 	}
diff --git a/apps/dav/lib/Upload/ChunkingV2Plugin.php b/apps/dav/lib/Upload/ChunkingV2Plugin.php
index 5c95cf1490635..108b10b050503 100644
--- a/apps/dav/lib/Upload/ChunkingV2Plugin.php
+++ b/apps/dav/lib/Upload/ChunkingV2Plugin.php
@@ -145,20 +145,15 @@ public function afterMkcol(RequestInterface $request, ResponseInterface $respons
 
 	public function beforePut(RequestInterface $request, ResponseInterface $response): bool {
 		if ($request->getHeader('OC-File-Type') == 1) {
-			// TODO: store default value in global location
-			$allowSymlinks = \OC::$server->get(\OC\AllConfig::class)->getSystemValueBool(
-				'localstorage.allowsymlinks', false);
-			if (!$allowSymlinks) {
-				throw new Forbidden("Server does not allow the creation of symlinks!");
-			}
 			$symlinkPath = $request->getPath();
 			$symlinkTarget = $request->getBodyAsString();
-			$parentNode = $this->server->tree->getNodeForPath(dirname($symlinkPath));
-			if(!$parentNode instanceof \OCA\DAV\Connector\Sabre\Directory) {
-				throw new Exception("Unable to upload '$symlinkPath' because the remote directory does not support symlink creation!");
-			}
-			$etag = $parentNode->createSymlink(basename($symlinkPath), $symlinkTarget);
-			$response->setHeader("OC-ETag", $etag);
+			$newEtag = "'$symlinkPath'->'$symlinkTarget'";
+			$infoData = [
+				'type' => \OC\Files\FileInfo::TYPE_SYMLINK,
+				'etag' => $newEtag,
+			];
+			\OC\Files\Filesystem::getView()->putFileInfo($symlinkPath, $infoData);
+			$response->setHeader("OC-ETag", $newEtag);
 			$response->setStatus(201);
 			$this->server->sapi->sendResponse($response);
 			return false;
diff --git a/lib/public/Files/FileInfo.php b/lib/public/Files/FileInfo.php
index 817b03dfc65f1..6d843bccd78a7 100644
--- a/lib/public/Files/FileInfo.php
+++ b/lib/public/Files/FileInfo.php
@@ -45,6 +45,10 @@ interface FileInfo {
 	 * @since 7.0.0
 	 */
 	public const TYPE_FOLDER = 'dir';
+	/**
+	 * @since TODO
+	 */
+	public const TYPE_SYMLINK = 'symlink';
 
 	/**
 	 * @const \OCP\Files\FileInfo::SPACE_NOT_COMPUTED Return value for a not computed space value