genode/repos/dde_rump/src/server/rump_fs/symlink.h

100 lines
2.0 KiB
C++

/**
* \brief Rump symlink node
* \author Sebastian Sumpf
* \date 2014-01-20
*/
/*
* Copyright (C) 2014-2017 Genode Labs GmbH
*
* This file is part of the Genode OS framework, which is distributed
* under the terms of the GNU Affero General Public License version 3.
*/
#ifndef _SYMLINK_H_
#define _SYMLINK_H_
/* Genode includes */
#include <file_system/util.h>
#include <os/path.h>
#include "node.h"
namespace Rump_fs {
class Symlink;
}
class Rump_fs::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));
}
void update_modification_time(Timestamp const time) override
{
/* XXX not handled for now: either dirfd or fd to _path is required */
}
size_t write(char const *src, size_t const len, seek_off_t seek_offset) override
{
/* Ideal symlink operations are atomic. */
if (!_create || seek_offset)
return 0;
/* src may not be null-terminated */
Genode::String<MAX_PATH_LEN> target(Genode::Cstring(src, len));
int ret = rump_sys_symlink(target.string(), _path.base());
return ret == -1 ? 0 : len;
}
size_t read(char *dst, size_t len, seek_off_t seek_offset) override
{
int ret = rump_sys_readlink(_path.base(), dst, len);
return ret == -1 ? 0 : ret;
}
Status status() override
{
struct stat st;
if (rump_sys_lstat(_path.base(), &st) < 0) {
st.st_mtime = 0;
}
return {
.size = length(),
.type = File_system::Node_type::SYMLINK,
.rwx = { .readable = true,
.writeable = true,
.executable = true },
.inode = inode(),
.modification_time = { (int64_t)st.st_mtime }
};
}
file_size_t length()
{
char link_to[MAX_PATH_LEN];
return read(link_to, MAX_PATH_LEN, 0);
}
};
#endif /* _SYMLINK_H_ */