linux/security/selinux/ss/ebitmap.h

146 lines
4.1 KiB
C

/*
* An extensible bitmap is a bitmap that supports an
* arbitrary number of bits. Extensible bitmaps are
* used to represent sets of values, such as types,
* roles, categories, and classes.
*
* Each extensible bitmap is implemented as a linked
* list of bitmap nodes, where each bitmap node has
* an explicitly specified starting bit position within
* the total bitmap.
*
* Author : Stephen Smalley, <sds@epoch.ncsc.mil>
*/
#ifndef _SS_EBITMAP_H_
#define _SS_EBITMAP_H_
#include <net/netlabel.h>
#define EBITMAP_UNIT_NUMS ((32 - sizeof(void *) - sizeof(u32)) \
/ sizeof(unsigned long))
#define EBITMAP_UNIT_SIZE BITS_PER_LONG
#define EBITMAP_SIZE (EBITMAP_UNIT_NUMS * EBITMAP_UNIT_SIZE)
#define EBITMAP_BIT 1ULL
#define EBITMAP_SHIFT_UNIT_SIZE(x) \
(((x) >> EBITMAP_UNIT_SIZE / 2) >> EBITMAP_UNIT_SIZE / 2)
struct ebitmap_node {
struct ebitmap_node *next;
unsigned long maps[EBITMAP_UNIT_NUMS];
u32 startbit;
};
struct ebitmap {
struct ebitmap_node *node; /* first node in the bitmap */
u32 highbit; /* highest position in the total bitmap */
};
#define ebitmap_length(e) ((e)->highbit)
#define ebitmap_startbit(e) ((e)->node ? (e)->node->startbit : 0)
static inline unsigned int ebitmap_start_positive(struct ebitmap *e,
struct ebitmap_node **n)
{
unsigned int ofs;
for (*n = e->node; *n; *n = (*n)->next) {
ofs = find_first_bit((*n)->maps, EBITMAP_SIZE);
if (ofs < EBITMAP_SIZE)
return (*n)->startbit + ofs;
}
return ebitmap_length(e);
}
static inline void ebitmap_init(struct ebitmap *e)
{
memset(e, 0, sizeof(*e));
}
static inline unsigned int ebitmap_next_positive(struct ebitmap *e,
struct ebitmap_node **n,
unsigned int bit)
{
unsigned int ofs;
ofs = find_next_bit((*n)->maps, EBITMAP_SIZE, bit - (*n)->startbit + 1);
if (ofs < EBITMAP_SIZE)
return ofs + (*n)->startbit;
for (*n = (*n)->next; *n; *n = (*n)->next) {
ofs = find_first_bit((*n)->maps, EBITMAP_SIZE);
if (ofs < EBITMAP_SIZE)
return ofs + (*n)->startbit;
}
return ebitmap_length(e);
}
#define EBITMAP_NODE_INDEX(node, bit) \
(((bit) - (node)->startbit) / EBITMAP_UNIT_SIZE)
#define EBITMAP_NODE_OFFSET(node, bit) \
(((bit) - (node)->startbit) % EBITMAP_UNIT_SIZE)
static inline int ebitmap_node_get_bit(struct ebitmap_node *n,
unsigned int bit)
{
unsigned int index = EBITMAP_NODE_INDEX(n, bit);
unsigned int ofs = EBITMAP_NODE_OFFSET(n, bit);
BUG_ON(index >= EBITMAP_UNIT_NUMS);
if ((n->maps[index] & (EBITMAP_BIT << ofs)))
return 1;
return 0;
}
static inline void ebitmap_node_set_bit(struct ebitmap_node *n,
unsigned int bit)
{
unsigned int index = EBITMAP_NODE_INDEX(n, bit);
unsigned int ofs = EBITMAP_NODE_OFFSET(n, bit);
BUG_ON(index >= EBITMAP_UNIT_NUMS);
n->maps[index] |= (EBITMAP_BIT << ofs);
}
static inline void ebitmap_node_clr_bit(struct ebitmap_node *n,
unsigned int bit)
{
unsigned int index = EBITMAP_NODE_INDEX(n, bit);
unsigned int ofs = EBITMAP_NODE_OFFSET(n, bit);
BUG_ON(index >= EBITMAP_UNIT_NUMS);
n->maps[index] &= ~(EBITMAP_BIT << ofs);
}
#define ebitmap_for_each_positive_bit(e, n, bit) \
for (bit = ebitmap_start_positive(e, &n); \
bit < ebitmap_length(e); \
bit = ebitmap_next_positive(e, &n, bit)) \
int ebitmap_cmp(struct ebitmap *e1, struct ebitmap *e2);
int ebitmap_cpy(struct ebitmap *dst, struct ebitmap *src);
int ebitmap_contains(struct ebitmap *e1, struct ebitmap *e2);
int ebitmap_get_bit(struct ebitmap *e, unsigned long bit);
int ebitmap_set_bit(struct ebitmap *e, unsigned long bit, int value);
void ebitmap_destroy(struct ebitmap *e);
int ebitmap_read(struct ebitmap *e, void *fp);
#ifdef CONFIG_NETLABEL
int ebitmap_netlbl_export(struct ebitmap *ebmap,
struct netlbl_lsm_secattr_catmap **catmap);
int ebitmap_netlbl_import(struct ebitmap *ebmap,
struct netlbl_lsm_secattr_catmap *catmap);
#else
static inline int ebitmap_netlbl_export(struct ebitmap *ebmap,
struct netlbl_lsm_secattr_catmap **catmap)
{
return -ENOMEM;
}
static inline int ebitmap_netlbl_import(struct ebitmap *ebmap,
struct netlbl_lsm_secattr_catmap *catmap)
{
return -ENOMEM;
}
#endif
#endif /* _SS_EBITMAP_H_ */