linux/security/selinux/ss/hashtab.h

/* SPDX-License-Identifier: GPL-2.0 */
/*
 * A hash table (hashtab) maintains associations between
 * key values and datum values.  The type of the key values
 * and the type of the datum values is arbitrary.  The
 * functions for hash computation and key comparison are
 * provided by the creator of the table.
 *
 * Author : Stephen Smalley, <[email protected]>
 */

#ifndef _SS_HASHTAB_H_
#define _SS_HASHTAB_H_

#include <linux/types.h>
#include <linux/errno.h>
#include <linux/sched.h>

#define HASHTAB_MAX_NODES …

struct hashtab_key_params { … };

struct hashtab_node { … };

struct hashtab { … };

struct hashtab_info { … };

/*
 * Initializes a new hash table with the specified characteristics.
 *
 * Returns -ENOMEM if insufficient space is available or 0 otherwise.
 */
int hashtab_init(struct hashtab *h, u32 nel_hint);

int __hashtab_insert(struct hashtab *h, struct hashtab_node **dst, void *key,
		     void *datum);

/*
 * Inserts the specified (key, datum) pair into the specified hash table.
 *
 * Returns -ENOMEM on memory allocation error,
 * -EEXIST if there is already an entry with the same key,
 * -EINVAL for general errors or
  0 otherwise.
 */
static inline int hashtab_insert(struct hashtab *h, void *key, void *datum,
				 struct hashtab_key_params key_params)
{ … }

/*
 * Searches for the entry with the specified key in the hash table.
 *
 * Returns NULL if no entry has the specified key or
 * the datum of the entry otherwise.
 */
static inline void *hashtab_search(struct hashtab *h, const void *key,
				   struct hashtab_key_params key_params)
{ … }

/*
 * Destroys the specified hash table.
 */
void hashtab_destroy(struct hashtab *h);

/*
 * Applies the specified apply function to (key,datum,args)
 * for each entry in the specified hash table.
 *
 * The order in which the function is applied to the entries
 * is dependent upon the internal structure of the hash table.
 *
 * If apply returns a non-zero status, then hashtab_map will cease
 * iterating through the hash table and will propagate the error
 * return to its caller.
 */
int hashtab_map(struct hashtab *h, int (*apply)(void *k, void *d, void *args),
		void *args);

int hashtab_duplicate(struct hashtab *new, const struct hashtab *orig,
		      int (*copy)(struct hashtab_node *new,
				  const struct hashtab_node *orig, void *args),
		      int (*destroy)(void *k, void *d, void *args), void *args);

#ifdef CONFIG_SECURITY_SELINUX_DEBUG
/* Fill info with some hash table statistics */
void hashtab_stat(struct hashtab *h, struct hashtab_info *info);
#else
static inline void hashtab_stat(struct hashtab *h, struct hashtab_info *info)
{
	return;
}
#endif

#endif /* _SS_HASHTAB_H */