genode/libports/include/libc-plugin/fd_alloc.h
Christian Prochaska e9ac4b653b Add support for symbolic links
This patch adds support for symbolic links in libc, libc plugins, file
system servers and Noux.

Fixes #322.
2012-10-08 15:05:02 +02:00

93 lines
1.8 KiB
C++

/*
* \brief file descriptor allocator interface
* \author Christian Prochaska
* \date 2010-01-21
*
*/
/*
* Copyright (C) 2010-2012 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 _LIBC_PLUGIN__FD_ALLOC_H_
#define _LIBC_PLUGIN__FD_ALLOC_H_
#include <base/allocator_avl.h>
#include <base/printf.h>
#include <os/path.h>
/* libc includes */
#include <stdlib.h>
#include <string.h>
#include <libc-plugin/plugin.h>
enum { MAX_NUM_FDS = 1024 };
namespace Libc {
/**
* Plugin-specific file-descriptor context
*/
class Plugin_context { };
enum { ANY_FD = -1 };
struct File_descriptor
{
int libc_fd;
char *fd_path; /* for 'fchdir()' */
Plugin *plugin;
Plugin_context *context;
void path(char const *newpath)
{
if (newpath) {
size_t path_size = ::strlen(newpath) + 1;
fd_path = (char*)malloc(path_size);
if (!fd_path) {
PERR("could not allocate path buffer for libc_fd %d%s",
libc_fd, libc_fd == ANY_FD ? " (any)" : "");
return;
}
::memcpy(fd_path, newpath, path_size);
} else
fd_path = 0;
}
};
class File_descriptor_allocator : Allocator_avl_tpl<File_descriptor>
{
public:
/**
* Constructor
*/
File_descriptor_allocator();
/**
* Allocate file descriptor
*/
File_descriptor *alloc(Plugin *plugin, Plugin_context *context, int libc_fd = -1);
/**
* Release file descriptor
*/
void free(File_descriptor *fdo);
File_descriptor *find_by_libc_fd(int libc_fd);
};
/**
* Return singleton instance of file-descriptor allocator
*/
extern File_descriptor_allocator *file_descriptor_allocator();
}
#endif /* _LIBC_PLUGIN__FD_ALLOC_H_ */