TOMOYO: Add refcounter on string data.

[net-next-2.6.git] / security / tomoyo / realpath.h

/*
 * security/tomoyo/realpath.h
 *
 * Get the canonicalized absolute pathnames. The basis for TOMOYO.
 *
 * Copyright (C) 2005-2009  NTT DATA CORPORATION
 *
 * Version: 2.2.0   2009/04/01
 *
 */

#ifndef _SECURITY_TOMOYO_REALPATH_H
#define _SECURITY_TOMOYO_REALPATH_H

struct path;
struct tomoyo_path_info;
struct tomoyo_io_buffer;

/* Convert binary string to ascii string. */
int tomoyo_encode(char *buffer, int buflen, const char *str);

/* Returns realpath(3) of the given pathname but ignores chroot'ed root. */
int tomoyo_realpath_from_path2(struct path *path, char *newname,
			       int newname_len);

/*
 * Returns realpath(3) of the given pathname but ignores chroot'ed root.
 * These functions use kzalloc(), so the caller must call kfree()
 * if these functions didn't return NULL.
 */
char *tomoyo_realpath(const char *pathname);
/*
 * Same with tomoyo_realpath() except that it doesn't follow the final symlink.
 */
char *tomoyo_realpath_nofollow(const char *pathname);
/* Same with tomoyo_realpath() except that the pathname is already solved. */
char *tomoyo_realpath_from_path(struct path *path);

/* Check memory quota. */
bool tomoyo_memory_ok(void *ptr);

/*
 * Keep the given name on the RAM.
 * The RAM is shared, so NEVER try to modify or kfree() the returned name.
 */
const struct tomoyo_path_info *tomoyo_get_name(const char *name);

/* Check for memory usage. */
int tomoyo_read_memory_counter(struct tomoyo_io_buffer *head);

/* Set memory quota. */
int tomoyo_write_memory_quota(struct tomoyo_io_buffer *head);

/* Initialize realpath related code. */
void __init tomoyo_realpath_init(void);

/*
 * tomoyo_name_entry is a structure which is used for linking
 * "struct tomoyo_path_info" into tomoyo_name_list .
 */
struct tomoyo_name_entry {
	struct list_head list;
	atomic_t users;
	struct tomoyo_path_info entry;
};

static inline void tomoyo_put_name(const struct tomoyo_path_info *name)
{
	if (name) {
		struct tomoyo_name_entry *ptr =
			container_of(name, struct tomoyo_name_entry, entry);
		atomic_dec(&ptr->users);
	}
}

#endif /* !defined(_SECURITY_TOMOYO_REALPATH_H) */