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/*
* 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_
#define MAPTYPE u64 /* portion of bitmap in each node */
#define MAPSIZE (sizeof(MAPTYPE) * 8) /* number of bits in node bitmap */
#define MAPBIT 1ULL /* a bit in the node bitmap */
struct ebitmap_node {
u32 startbit; /* starting position in the total bitmap */
MAPTYPE map; /* this node's portion of the bitmap */
struct ebitmap_node *next;
};
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(struct ebitmap *e,
struct ebitmap_node **n)
{
*n = e->node;
return ebitmap_startbit(e);
}
static inline void ebitmap_init(struct ebitmap *e)
{
memset(e, 0, sizeof(*e));
}
static inline unsigned int ebitmap_next(struct ebitmap_node **n,
unsigned int bit)
{
if ((bit == ((*n)->startbit + MAPSIZE - 1)) &&
(*n)->next) {
*n = (*n)->next;
return (*n)->startbit;
}
return (bit+1);
}
static inline int ebitmap_node_get_bit(struct ebitmap_node * n,
unsigned int bit)
{
if (n->map & (MAPBIT << (bit - n->startbit)))
return 1;
return 0;
}
#define ebitmap_for_each_bit(e, n, bit) \
for (bit = ebitmap_start(e, &n); bit < ebitmap_length(e); bit = ebitmap_next(&n, bit)) \
int ebitmap_cmp(struct ebitmap *e1, struct ebitmap *e2);
int ebitmap_cpy(struct ebitmap *dst, struct ebitmap *src);
int ebitmap_export(const struct ebitmap *src,
unsigned char **dst,
size_t *dst_len);
int ebitmap_import(const unsigned char *src,
size_t src_len,
struct ebitmap *dst);
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);
#endif /* _SS_EBITMAP_H_ */
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