2f1db06deb
Allow symlinks to be passed to the read and write file system utilities. Disallow writes to symlinks with offsets in file system servers, this is to ensure that writing the target of a symlink is an atomic operation. Fixes #1604
74 lines
1.3 KiB
C++
74 lines
1.3 KiB
C++
/**
|
|
* \brief Rump symlink node
|
|
* \author Sebastian Sumpf
|
|
* \date 2014-01-20
|
|
*/
|
|
|
|
/*
|
|
* Copyright (C) 2014 Genode Labs GmbH
|
|
*
|
|
* This file is part of the Genode OS framework, which is distributed
|
|
* under the terms of the GNU General Public License version 2.
|
|
*/
|
|
|
|
#ifndef _SYMLINK_H_
|
|
#define _SYMLINK_H_
|
|
|
|
/* Genode includes */
|
|
#include <file_system/util.h>
|
|
#include <os/path.h>
|
|
|
|
#include "node.h"
|
|
|
|
namespace File_system {
|
|
class Symlink;
|
|
}
|
|
|
|
class File_system::Symlink : public Node
|
|
{
|
|
private:
|
|
|
|
typedef Genode::Path<MAX_PATH_LEN> Path;
|
|
|
|
Path _path;
|
|
bool _create;
|
|
|
|
public:
|
|
|
|
Symlink(char const *dir, char const *name, bool create)
|
|
: Node(0), _path(name, dir), _create(create)
|
|
{
|
|
Node::name(name);
|
|
}
|
|
|
|
Symlink(char const *path)
|
|
: Node(0), _path(path), _create(false)
|
|
{
|
|
Node::name(basename(path));
|
|
}
|
|
|
|
size_t write(char const *src, size_t len, seek_off_t seek_offset)
|
|
{
|
|
/* Ideal symlink operations are atomic. */
|
|
if (!_create || seek_offset)
|
|
return 0;
|
|
|
|
int ret = rump_sys_symlink(src, _path.base());
|
|
return ret == -1 ? 0 : ret;
|
|
}
|
|
|
|
size_t read(char *dst, size_t len, seek_off_t seek_offset)
|
|
{
|
|
int ret = rump_sys_readlink(_path.base(), dst, len);
|
|
return ret == -1 ? 0 : ret;
|
|
}
|
|
|
|
file_size_t length()
|
|
{
|
|
char link_to[MAX_PATH_LEN];
|
|
return read(link_to, MAX_PATH_LEN, 0);
|
|
}
|
|
};
|
|
|
|
#endif /* _SYMLINK_H_ */
|