Add storage and cache wrappers to jail a storage to a subfolder

5 files changed, 1018 insertions, 1 deletions

diff --git a/lib/private/files/cache/cache.php b/lib/private/files/cache/cache.php
index 2c12f834518..4157da2281c 100644
--- a/lib/private/files/cache/cache.php
+++ b/lib/private/files/cache/cache.php
@@ -585,7 +585,7 @@ class Cache {
 	/**
 	 * find a folder in the cache which has not been fully scanned
 	 *
-	 * If multiply incomplete folders are in the cache, the one with the highest id will be returned,
+	 * If multiple incomplete folders are in the cache, the one with the highest id will be returned,
 	 * use the one with the highest id gives the best result with the background scanner, since that is most
 	 * likely the folder where we stopped scanning previously
 	 *
diff --git a/lib/private/files/cache/wrapper/cachejail.php b/lib/private/files/cache/wrapper/cachejail.php
new file mode 100644
index 00000000000..7982293f5ed
--- /dev/null
+++ b/lib/private/files/cache/wrapper/cachejail.php
@@ -0,0 +1,255 @@
+<?php
+/**
+ * Copyright (c) 2014 Robin Appelman <icewind@owncloud.com>
+ * This file is licensed under the Affero General Public License version 3 or
+ * later.
+ * See the COPYING-README file.
+ */
+
+namespace OC\Files\Cache\Wrapper;
+
+/**
+ * Jail to a subdirectory of the wrapped cache
+ */
+class CacheJail extends CacheWrapper {
+	/**
+	 * @var string
+	 */
+	protected $root;
+
+	/**
+	 * @param \OC\Files\Cache\Cache $cache
+	 * @param string $root
+	 */
+	public function __construct($cache, $root) {
+		parent::__construct($cache);
+		$this->root = $root;
+	}
+
+	protected function getSourcePath($path) {
+		if ($path === '') {
+			return $this->root;
+		} else {
+			return $this->root . '/' . $path;
+		}
+	}
+
+	/**
+	 * @param string $path
+	 * @return null|string the jailed path or null if the path is outside the jail
+	 */
+	protected function getJailedPath($path) {
+		$rootLength = strlen($this->root) + 1;
+		if ($path === $this->root) {
+			return '';
+		} else if (substr($path, 0, $rootLength) === $this->root . '/') {
+			return substr($path, $rootLength);
+		} else {
+			return null;
+		}
+	}
+
+	/**
+	 * @param array $entry
+	 * @return array
+	 */
+	protected function formatCacheEntry($entry) {
+		if (isset($entry['path'])) {
+			$entry['path'] = $this->getJailedPath($entry['path']);
+		}
+		return $entry;
+	}
+
+	protected function filterCacheEntry($entry) {
+		$rootLength = strlen($this->root) + 1;
+		return ($entry['path'] === $this->root) or (substr($entry['path'], 0, $rootLength) === $this->root . '/');
+	}
+
+	/**
+	 * get the stored metadata of a file or folder
+	 *
+	 * @param string /int $file
+	 * @return array|false
+	 */
+	public function get($file) {
+		if (is_string($file) or $file == '') {
+			$file = $this->getSourcePath($file);
+		}
+		return parent::get($file);
+	}
+
+	/**
+	 * store meta data for a file or folder
+	 *
+	 * @param string $file
+	 * @param array $data
+	 *
+	 * @return int file id
+	 */
+	public function put($file, array $data) {
+		return $this->cache->put($this->getSourcePath($file), $data);
+	}
+
+	/**
+	 * update the metadata in the cache
+	 *
+	 * @param int $id
+	 * @param array $data
+	 */
+	public function update($id, array $data) {
+		$this->cache->update($this->getSourcePath($id), $data);
+	}
+
+	/**
+	 * get the file id for a file
+	 *
+	 * @param string $file
+	 * @return int
+	 */
+	public function getId($file) {
+		return $this->cache->getId($this->getSourcePath($file));
+	}
+
+	/**
+	 * get the id of the parent folder of a file
+	 *
+	 * @param string $file
+	 * @return int
+	 */
+	public function getParentId($file) {
+		if ($file === '') {
+			return -1;
+		} else {
+			return $this->cache->getParentId($this->getSourcePath($file));
+		}
+	}
+
+	/**
+	 * check if a file is available in the cache
+	 *
+	 * @param string $file
+	 * @return bool
+	 */
+	public function inCache($file) {
+		return $this->cache->inCache($this->getSourcePath($file));
+	}
+
+	/**
+	 * remove a file or folder from the cache
+	 *
+	 * @param string $file
+	 */
+	public function remove($file) {
+		$this->cache->remove($this->getSourcePath($file));
+	}
+
+	/**
+	 * Move a file or folder in the cache
+	 *
+	 * @param string $source
+	 * @param string $target
+	 */
+	public function move($source, $target) {
+		$this->cache->move($this->getSourcePath($source), $this->getSourcePath($target));
+	}
+
+	/**
+	 * remove all entries for files that are stored on the storage from the cache
+	 */
+	public function clear() {
+		$this->cache->remove($this->root);
+	}
+
+	/**
+	 * @param string $file
+	 *
+	 * @return int, Cache::NOT_FOUND, Cache::PARTIAL, Cache::SHALLOW or Cache::COMPLETE
+	 */
+	public function getStatus($file) {
+		return $this->cache->getStatus($this->getSourcePath($file));
+	}
+
+	private function formatSearchResults($results) {
+		$results = array_filter($results, array($this, 'filterCacheEntry'));
+		$results = array_values($results);
+		return array_map(array($this, 'formatCacheEntry'), $results);
+	}
+
+	/**
+	 * search for files matching $pattern
+	 *
+	 * @param string $pattern
+	 * @return array an array of file data
+	 */
+	public function search($pattern) {
+		$results = $this->cache->search($pattern);
+		return $this->formatSearchResults($results);
+	}
+
+	/**
+	 * search for files by mimetype
+	 *
+	 * @param string $mimetype
+	 * @return array
+	 */
+	public function searchByMime($mimetype) {
+		$results = $this->cache->searchByMime($mimetype);
+		return $this->formatSearchResults($results);
+	}
+
+	/**
+	 * update the folder size and the size of all parent folders
+	 *
+	 * @param string|boolean $path
+	 * @param array $data (optional) meta data of the folder
+	 */
+	public function correctFolderSize($path, $data = null) {
+		$this->cache->correctFolderSize($this->getSourcePath($path), $data);
+	}
+
+	/**
+	 * get the size of a folder and set it in the cache
+	 *
+	 * @param string $path
+	 * @param array $entry (optional) meta data of the folder
+	 * @return int
+	 */
+	public function calculateFolderSize($path, $entry = null) {
+		return $this->cache->calculateFolderSize($this->getSourcePath($path), $entry);
+	}
+
+	/**
+	 * get all file ids on the files on the storage
+	 *
+	 * @return int[]
+	 */
+	public function getAll() {
+		// not supported
+		return array();
+	}
+
+	/**
+	 * find a folder in the cache which has not been fully scanned
+	 *
+	 * If multiply incomplete folders are in the cache, the one with the highest id will be returned,
+	 * use the one with the highest id gives the best result with the background scanner, since that is most
+	 * likely the folder where we stopped scanning previously
+	 *
+	 * @return string|bool the path of the folder or false when no folder matched
+	 */
+	public function getIncomplete() {
+		// not supported
+		return false;
+	}
+
+	/**
+	 * get the path of a file on this storage by it's id
+	 *
+	 * @param int $id
+	 * @return string|null
+	 */
+	public function getPathById($id) {
+		$path = $this->cache->getPathById($id);
+		return $this->getJailedPath($path);
+	}
+}
diff --git a/lib/private/files/cache/wrapper/cachewrapper.php b/lib/private/files/cache/wrapper/cachewrapper.php
new file mode 100644
index 00000000000..040358ec657
--- /dev/null
+++ b/lib/private/files/cache/wrapper/cachewrapper.php
@@ -0,0 +1,247 @@
+<?php
+/**
+ * Copyright (c) 2014 Robin Appelman <icewind@owncloud.com>
+ * This file is licensed under the Affero General Public License version 3 or
+ * later.
+ * See the COPYING-README file.
+ */
+
+namespace OC\Files\Cache\Wrapper;
+
+use OC\Files\Cache\Cache;
+
+class CacheWrapper extends Cache {
+	/**
+	 * @var \OC\Files\Cache\Cache
+	 */
+	protected $cache;
+
+	/**
+	 * @param \OC\Files\Cache\Cache $cache
+	 */
+	public function __construct($cache) {
+		$this->cache = $cache;
+	}
+
+	/**
+	 * Make it easy for wrappers to modify every returned cache entry
+	 *
+	 * @param array $entry
+	 * @return array
+	 */
+	protected function formatCacheEntry($entry) {
+		return $entry;
+	}
+
+	/**
+	 * get the stored metadata of a file or folder
+	 *
+	 * @param string /int $file
+	 * @return array|false
+	 */
+	public function get($file) {
+		$result = $this->cache->get($file);
+		if ($result) {
+			$result = $this->formatCacheEntry($result);
+		}
+		return $result;
+	}
+
+	/**
+	 * get the metadata of all files stored in $folder
+	 *
+	 * @param string $folder
+	 * @return array
+	 */
+	public function getFolderContents($folder) {
+		// cant do a simple $this->cache->.... call here since getFolderContentsById needs to be called on this
+		// and not the wrapped cache
+		$fileId = $this->getId($folder);
+		return $this->getFolderContentsById($fileId);
+	}
+
+	/**
+	 * get the metadata of all files stored in $folder
+	 *
+	 * @param int $fileId the file id of the folder
+	 * @return array
+	 */
+	public function getFolderContentsById($fileId) {
+		$results = $this->cache->getFolderContentsById($fileId);
+		return array_map(array($this, 'formatCacheEntry'), $results);
+	}
+
+	/**
+	 * store meta data for a file or folder
+	 *
+	 * @param string $file
+	 * @param array $data
+	 *
+	 * @return int file id
+	 */
+	public function put($file, array $data) {
+		return $this->cache->put($file, $data);
+	}
+
+	/**
+	 * update the metadata in the cache
+	 *
+	 * @param int $id
+	 * @param array $data
+	 */
+	public function update($id, array $data) {
+		$this->cache->update($id, $data);
+	}
+
+	/**
+	 * get the file id for a file
+	 *
+	 * @param string $file
+	 * @return int
+	 */
+	public function getId($file) {
+		return $this->cache->getId($file);
+	}
+
+	/**
+	 * get the id of the parent folder of a file
+	 *
+	 * @param string $file
+	 * @return int
+	 */
+	public function getParentId($file) {
+		return $this->cache->getParentId($file);
+	}
+
+	/**
+	 * check if a file is available in the cache
+	 *
+	 * @param string $file
+	 * @return bool
+	 */
+	public function inCache($file) {
+		return $this->cache->inCache($file);
+	}
+
+	/**
+	 * remove a file or folder from the cache
+	 *
+	 * @param string $file
+	 */
+	public function remove($file) {
+		$this->cache->remove($file);
+	}
+
+	/**
+	 * Move a file or folder in the cache
+	 *
+	 * @param string $source
+	 * @param string $target
+	 */
+	public function move($source, $target) {
+		$this->cache->move($source, $target);
+	}
+
+	/**
+	 * remove all entries for files that are stored on the storage from the cache
+	 */
+	public function clear() {
+		$this->cache->clear();
+	}
+
+	/**
+	 * @param string $file
+	 *
+	 * @return int, Cache::NOT_FOUND, Cache::PARTIAL, Cache::SHALLOW or Cache::COMPLETE
+	 */
+	public function getStatus($file) {
+		return $this->cache->getStatus($file);
+	}
+
+	/**
+	 * search for files matching $pattern
+	 *
+	 * @param string $pattern
+	 * @return array an array of file data
+	 */
+	public function search($pattern) {
+		$results = $this->cache->search($pattern);
+		return array_map(array($this, 'formatCacheEntry'), $results);
+	}
+
+	/**
+	 * search for files by mimetype
+	 *
+	 * @param string $mimetype
+	 * @return array
+	 */
+	public function searchByMime($mimetype) {
+		$results = $this->cache->searchByMime($mimetype);
+		return array_map(array($this, 'formatCacheEntry'), $results);
+	}
+
+	/**
+	 * update the folder size and the size of all parent folders
+	 *
+	 * @param string|boolean $path
+	 * @param array $data (optional) meta data of the folder
+	 */
+	public function correctFolderSize($path, $data = null) {
+		$this->cache->correctFolderSize($path, $data);
+	}
+
+	/**
+	 * get the size of a folder and set it in the cache
+	 *
+	 * @param string $path
+	 * @param array $entry (optional) meta data of the folder
+	 * @return int
+	 */
+	public function calculateFolderSize($path, $entry = null) {
+		return $this->cache->calculateFolderSize($path, $entry);
+	}
+
+	/**
+	 * get all file ids on the files on the storage
+	 *
+	 * @return int[]
+	 */
+	public function getAll() {
+		return $this->cache->getAll();
+	}
+
+	/**
+	 * find a folder in the cache which has not been fully scanned
+	 *
+	 * If multiple incomplete folders are in the cache, the one with the highest id will be returned,
+	 * use the one with the highest id gives the best result with the background scanner, since that is most
+	 * likely the folder where we stopped scanning previously
+	 *
+	 * @return string|bool the path of the folder or false when no folder matched
+	 */
+	public function getIncomplete() {
+		return $this->cache->getIncomplete();
+	}
+
+	/**
+	 * get the path of a file on this storage by it's id
+	 *
+	 * @param int $id
+	 * @return string|null
+	 */
+	public function getPathById($id) {
+		return $this->cache->getPathById($id);
+	}
+
+	/**
+	 * get the storage id of the storage for a file and the internal path of the file
+	 * unlike getPathById this does not limit the search to files on this storage and
+	 * instead does a global search in the cache table
+	 *
+	 * @param int $id
+	 * @return array, first element holding the storage id, second the path
+	 */
+	static public function getById($id) {
+		return parent::getById($id);
+	}
+}
diff --git a/lib/private/files/storage/wrapper/jail.php b/lib/private/files/storage/wrapper/jail.php
new file mode 100644
index 00000000000..22b96765757
--- /dev/null
+++ b/lib/private/files/storage/wrapper/jail.php
@@ -0,0 +1,413 @@
+<?php
+/**
+ * Copyright (c) 2014 Robin Appelman <icewind@owncloud.com>
+ * This file is licensed under the Affero General Public License version 3 or
+ * later.
+ * See the COPYING-README file.
+ */
+
+namespace OC\Files\Storage\Wrapper;
+
+use OC\Files\Cache\Wrapper\CacheJail;
+
+/**
+ * Jail to a subdirectory of the wrapped storage
+ *
+ * This restricts access to a subfolder of the wrapped storage with the subfolder becoming the root folder new storage
+ */
+class Jail extends Wrapper {
+	/**
+	 * @var string
+	 */
+	protected $rootPath;
+
+	/**
+	 * @param array $arguments ['storage' => $storage, 'mask' => $root]
+	 *
+	 * $storage: The storage that will be wrapper
+	 * $root: The folder in the wrapped storage that will become the root folder of the wrapped storage
+	 */
+	public function __construct($arguments) {
+		parent::__construct($arguments);
+		$this->rootPath = $arguments['root'];
+	}
+
+	protected function getSourcePath($path) {
+		if ($path === '') {
+			return $this->rootPath;
+		} else {
+			return $this->rootPath . '/' . $path;
+		}
+	}
+
+	public function getId() {
+		return 'link:' . parent::getId() . ':' . $this->rootPath;
+	}
+
+	/**
+	 * see http://php.net/manual/en/function.mkdir.php
+	 *
+	 * @param string $path
+	 * @return bool
+	 */
+	public function mkdir($path) {
+		return $this->storage->mkdir($this->getSourcePath($path));
+	}
+
+	/**
+	 * see http://php.net/manual/en/function.rmdir.php
+	 *
+	 * @param string $path
+	 * @return bool
+	 */
+	public function rmdir($path) {
+		return $this->storage->rmdir($this->getSourcePath($path));
+	}
+
+	/**
+	 * see http://php.net/manual/en/function.opendir.php
+	 *
+	 * @param string $path
+	 * @return resource
+	 */
+	public function opendir($path) {
+		return $this->storage->opendir($this->getSourcePath($path));
+	}
+
+	/**
+	 * see http://php.net/manual/en/function.is_dir.php
+	 *
+	 * @param string $path
+	 * @return bool
+	 */
+	public function is_dir($path) {
+		return $this->storage->is_dir($this->getSourcePath($path));
+	}
+
+	/**
+	 * see http://php.net/manual/en/function.is_file.php
+	 *
+	 * @param string $path
+	 * @return bool
+	 */
+	public function is_file($path) {
+		return $this->storage->is_file($this->getSourcePath($path));
+	}
+
+	/**
+	 * see http://php.net/manual/en/function.stat.php
+	 * only the following keys are required in the result: size and mtime
+	 *
+	 * @param string $path
+	 * @return array
+	 */
+	public function stat($path) {
+		return $this->storage->stat($this->getSourcePath($path));
+	}
+
+	/**
+	 * see http://php.net/manual/en/function.filetype.php
+	 *
+	 * @param string $path
+	 * @return bool
+	 */
+	public function filetype($path) {
+		return $this->storage->filetype($this->getSourcePath($path));
+	}
+
+	/**
+	 * see http://php.net/manual/en/function.filesize.php
+	 * The result for filesize when called on a folder is required to be 0
+	 *
+	 * @param string $path
+	 * @return int
+	 */
+	public function filesize($path) {
+		return $this->storage->filesize($this->getSourcePath($path));
+	}
+
+	/**
+	 * check if a file can be created in $path
+	 *
+	 * @param string $path
+	 * @return bool
+	 */
+	public function isCreatable($path) {
+		return $this->storage->isCreatable($this->getSourcePath($path));
+	}
+
+	/**
+	 * check if a file can be read
+	 *
+	 * @param string $path
+	 * @return bool
+	 */
+	public function isReadable($path) {
+		return $this->storage->isReadable($this->getSourcePath($path));
+	}
+
+	/**
+	 * check if a file can be written to
+	 *
+	 * @param string $path
+	 * @return bool
+	 */
+	public function isUpdatable($path) {
+		return $this->storage->isUpdatable($this->getSourcePath($path));
+	}
+
+	/**
+	 * check if a file can be deleted
+	 *
+	 * @param string $path
+	 * @return bool
+	 */
+	public function isDeletable($path) {
+		return $this->storage->isDeletable($this->getSourcePath($path));
+	}
+
+	/**
+	 * check if a file can be shared
+	 *
+	 * @param string $path
+	 * @return bool
+	 */
+	public function isSharable($path) {
+		return $this->storage->isSharable($this->getSourcePath($path));
+	}
+
+	/**
+	 * get the full permissions of a path.
+	 * Should return a combination of the PERMISSION_ constants defined in lib/public/constants.php
+	 *
+	 * @param string $path
+	 * @return int
+	 */
+	public function getPermissions($path) {
+		return $this->storage->getPermissions($this->getSourcePath($path));
+	}
+
+	/**
+	 * see http://php.net/manual/en/function.file_exists.php
+	 *
+	 * @param string $path
+	 * @return bool
+	 */
+	public function file_exists($path) {
+		return $this->storage->file_exists($this->getSourcePath($path));
+	}
+
+	/**
+	 * see http://php.net/manual/en/function.filemtime.php
+	 *
+	 * @param string $path
+	 * @return int
+	 */
+	public function filemtime($path) {
+		return $this->storage->filemtime($this->getSourcePath($path));
+	}
+
+	/**
+	 * see http://php.net/manual/en/function.file_get_contents.php
+	 *
+	 * @param string $path
+	 * @return string
+	 */
+	public function file_get_contents($path) {
+		return $this->storage->file_get_contents($this->getSourcePath($path));
+	}
+
+	/**
+	 * see http://php.net/manual/en/function.file_put_contents.php
+	 *
+	 * @param string $path
+	 * @param string $data
+	 * @return bool
+	 */
+	public function file_put_contents($path, $data) {
+		return $this->storage->file_put_contents($this->getSourcePath($path), $data);
+	}
+
+	/**
+	 * see http://php.net/manual/en/function.unlink.php
+	 *
+	 * @param string $path
+	 * @return bool
+	 */
+	public function unlink($path) {
+		return $this->storage->unlink($this->getSourcePath($path));
+	}
+
+	/**
+	 * see http://php.net/manual/en/function.rename.php
+	 *
+	 * @param string $path1
+	 * @param string $path2
+	 * @return bool
+	 */
+	public function rename($path1, $path2) {
+		return $this->storage->rename($this->getSourcePath($path1), $this->getSourcePath($path2));
+	}
+
+	/**
+	 * see http://php.net/manual/en/function.copy.php
+	 *
+	 * @param string $path1
+	 * @param string $path2
+	 * @return bool
+	 */
+	public function copy($path1, $path2) {
+		return $this->storage->copy($this->getSourcePath($path1), $this->getSourcePath($path2));
+	}
+
+	/**
+	 * see http://php.net/manual/en/function.fopen.php
+	 *
+	 * @param string $path
+	 * @param string $mode
+	 * @return resource
+	 */
+	public function fopen($path, $mode) {
+		return $this->storage->fopen($this->getSourcePath($path), $mode);
+	}
+
+	/**
+	 * get the mimetype for a file or folder
+	 * The mimetype for a folder is required to be "httpd/unix-directory"
+	 *
+	 * @param string $path
+	 * @return string
+	 */
+	public function getMimeType($path) {
+		return $this->storage->getMimeType($this->getSourcePath($path));
+	}
+
+	/**
+	 * see http://php.net/manual/en/function.hash.php
+	 *
+	 * @param string $type
+	 * @param string $path
+	 * @param bool $raw
+	 * @return string
+	 */
+	public function hash($type, $path, $raw = false) {
+		return $this->storage->hash($type, $this->getSourcePath($path), $raw);
+	}
+
+	/**
+	 * see http://php.net/manual/en/function.free_space.php
+	 *
+	 * @param string $path
+	 * @return int
+	 */
+	public function free_space($path) {
+		return $this->storage->free_space($this->getSourcePath($path));
+	}
+
+	/**
+	 * search for occurrences of $query in file names
+	 *
+	 * @param string $query
+	 * @return array
+	 */
+	public function search($query) {
+		return $this->storage->search($query);
+	}
+
+	/**
+	 * see http://php.net/manual/en/function.touch.php
+	 * If the backend does not support the operation, false should be returned
+	 *
+	 * @param string $path
+	 * @param int $mtime
+	 * @return bool
+	 */
+	public function touch($path, $mtime = null) {
+		return $this->storage->touch($this->getSourcePath($path), $mtime);
+	}
+
+	/**
+	 * get the path to a local version of the file.
+	 * The local version of the file can be temporary and doesn't have to be persistent across requests
+	 *
+	 * @param string $path
+	 * @return string
+	 */
+	public function getLocalFile($path) {
+		return $this->storage->getLocalFile($this->getSourcePath($path));
+	}
+
+	/**
+	 * get the path to a local version of the folder.
+	 * The local version of the folder can be temporary and doesn't have to be persistent across requests
+	 *
+	 * @param string $path
+	 * @return string
+	 */
+	public function getLocalFolder($path) {
+		return $this->storage->getLocalFolder($this->getSourcePath($path));
+	}
+
+	/**
+	 * check if a file or folder has been updated since $time
+	 *
+	 * @param string $path
+	 * @param int $time
+	 * @return bool
+	 *
+	 * hasUpdated for folders should return at least true if a file inside the folder is add, removed or renamed.
+	 * returning true for other changes in the folder is optional
+	 */
+	public function hasUpdated($path, $time) {
+		return $this->storage->hasUpdated($this->getSourcePath($path), $time);
+	}
+
+	/**
+	 * get a cache instance for the storage
+	 *
+	 * @param string $path
+	 * @param \OC\Files\Storage\Storage (optional) the storage to pass to the cache
+	 * @return \OC\Files\Cache\Cache
+	 */
+	public function getCache($path = '', $storage = null) {
+		if (!$storage) {
+			$storage = $this;
+		}
+		$sourceCache = $this->storage->getCache($this->getSourcePath($path), $storage);
+		return new CacheJail($sourceCache, $this->rootPath);
+	}
+
+	/**
+	 * get the user id of the owner of a file or folder
+	 *
+	 * @param string $path
+	 * @return string
+	 */
+	public function getOwner($path) {
+		return $this->storage->getOwner($this->getSourcePath($path));
+	}
+
+	/**
+	 * get a watcher instance for the cache
+	 *
+	 * @param string $path
+	 * @param \OC\Files\Storage\Storage (optional) the storage to pass to the watcher
+	 * @return \OC\Files\Cache\Watcher
+	 */
+	public function getWatcher($path = '', $storage = null) {
+		if (!$storage) {
+			$storage = $this;
+		}
+		return $this->storage->getWatcher($this->getSourcePath($path), $storage);
+	}
+
+	/**
+	 * get the ETag for a file or folder
+	 *
+	 * @param string $path
+	 * @return string
+	 */
+	public function getETag($path) {
+		return $this->storage->getETag($this->getSourcePath($path));
+	}
+}
diff --git a/lib/private/files/storage/wrapper/permissionsmask.php b/lib/private/files/storage/wrapper/permissionsmask.php
new file mode 100644
index 00000000000..be5cb6bbaa3
--- /dev/null
+++ b/lib/private/files/storage/wrapper/permissionsmask.php
@@ -0,0 +1,102 @@
+<?php
+/**
+ * Copyright (c) 2014 Robin Appelman <icewind@owncloud.com>
+ * This file is licensed under the Affero General Public License version 3 or
+ * later.
+ * See the COPYING-README file.
+ */
+
+namespace OC\Files\Storage\Wrapper;
+
+use OC\Files\Cache\Wrapper\CachePermissionsMask;
+
+/**
+ * Mask the permissions of a storage
+ *
+ * Note that the read permissions cant be masked
+ */
+class PermissionsMask extends Wrapper {
+	/**
+	 * @var int
+	 */
+	private $mask;
+
+	public function __construct($arguments) {
+		parent::__construct($arguments);
+		$this->mask = $arguments['mask'];
+	}
+
+	private function checkMask($permissions) {
+		return ($this->mask & $permissions) === $permissions;
+	}
+
+	public function isUpdatable($path) {
+		return $this->checkMask(\OCP\PERMISSION_UPDATE) and parent::isUpdatable($path);
+	}
+
+	public function isCreatable($path) {
+		return $this->checkMask(\OCP\PERMISSION_CREATE) and parent::isCreatable($path);
+	}
+
+	public function isDeletable($path) {
+		return $this->checkMask(\OCP\PERMISSION_DELETE) and parent::isDeletable($path);
+	}
+
+	public function getPermissions($path) {
+		return $this->storage->getPermissions($path) & $this->mask;
+	}
+
+	public function rename($path1, $path2) {
+		return $this->checkMask(\OCP\PERMISSION_UPDATE) and parent::rename($path1, $path2);
+	}
+
+	public function copy($path1, $path2) {
+		return $this->checkMask(\OCP\PERMISSION_CREATE) and parent::copy($path1, $path2);
+	}
+
+	public function touch($path, $mtime = null) {
+		$permissions = $this->file_exists($path) ? \OCP\PERMISSION_UPDATE : \OCP\PERMISSION_CREATE;
+		return $this->checkMask($permissions) and parent::touch($path, $mtime);
+	}
+
+	public function mkdir($path) {
+		return $this->checkMask(\OCP\PERMISSION_CREATE) and parent::mkdir($path);
+	}
+
+	public function rmdir($path) {
+		return $this->checkMask(\OCP\PERMISSION_DELETE) and parent::rmdir($path);
+	}
+
+	public function unlink($path) {
+		return $this->checkMask(\OCP\PERMISSION_DELETE) and parent::unlink($path);
+	}
+
+	public function file_put_contents($path, $data) {
+		$permissions = $this->file_exists($path) ? \OCP\PERMISSION_UPDATE : \OCP\PERMISSION_CREATE;
+		return $this->checkMask($permissions) and parent::file_put_contents($path, $data);
+	}
+
+	public function fopen($path, $mode) {
+		if ($mode === 'r' or $mode === 'rb') {
+			return parent::fopen($path, $mode);
+		} else {
+			$permissions = $this->file_exists($path) ? \OCP\PERMISSION_UPDATE : \OCP\PERMISSION_CREATE;
+			return $this->checkMask($permissions) ? parent::fopen($path, $mode) : false;
+		}
+	}
+
+	/**
+	 * get a cache instance for the storage
+	 *
+	 * @param string $path
+	 * @param \OC\Files\Storage\Storage (optional) the storage to pass to the cache
+	 * @return \OC\Files\Cache\Cache
+	 */
+	public function getCache($path = '', $storage = null) {
+		if (!$storage) {
+			$storage = $this;
+		}
+		$sourceCache = parent::getCache($path, $storage);
+		return new CachePermissionsMask($sourceCache, $this->mask);
+	}
+}