2 * An extensible bitmap is a bitmap that supports an
3 * arbitrary number of bits. Extensible bitmaps are
4 * used to represent sets of values, such as types,
5 * roles, categories, and classes.
7 * Each extensible bitmap is implemented as a linked
8 * list of bitmap nodes, where each bitmap node has
9 * an explicitly specified starting bit position within
12 * Author : Stephen Smalley, <sds@epoch.ncsc.mil>
14 #ifndef _SS_EBITMAP_H_
15 #define _SS_EBITMAP_H_
17 #define MAPTYPE u64 /* portion of bitmap in each node */
18 #define MAPSIZE (sizeof(MAPTYPE) * 8) /* number of bits in node bitmap */
19 #define MAPBIT 1ULL /* a bit in the node bitmap */
22 u32 startbit; /* starting position in the total bitmap */
23 MAPTYPE map; /* this node's portion of the bitmap */
24 struct ebitmap_node *next;
28 struct ebitmap_node *node; /* first node in the bitmap */
29 u32 highbit; /* highest position in the total bitmap */
32 #define ebitmap_length(e) ((e)->highbit)
33 #define ebitmap_startbit(e) ((e)->node ? (e)->node->startbit : 0)
35 static inline unsigned int ebitmap_start(struct ebitmap *e,
36 struct ebitmap_node **n)
39 return ebitmap_startbit(e);
42 static inline void ebitmap_init(struct ebitmap *e)
44 memset(e, 0, sizeof(*e));
47 static inline unsigned int ebitmap_next(struct ebitmap_node **n,
50 if ((bit == ((*n)->startbit + MAPSIZE - 1)) &&
53 return (*n)->startbit;
59 static inline int ebitmap_node_get_bit(struct ebitmap_node * n,
62 if (n->map & (MAPBIT << (bit - n->startbit)))
67 #define ebitmap_for_each_bit(e, n, bit) \
68 for (bit = ebitmap_start(e, &n); bit < ebitmap_length(e); bit = ebitmap_next(&n, bit)) \
70 int ebitmap_cmp(struct ebitmap *e1, struct ebitmap *e2);
71 int ebitmap_cpy(struct ebitmap *dst, struct ebitmap *src);
72 int ebitmap_contains(struct ebitmap *e1, struct ebitmap *e2);
73 int ebitmap_get_bit(struct ebitmap *e, unsigned long bit);
74 int ebitmap_set_bit(struct ebitmap *e, unsigned long bit, int value);
75 void ebitmap_destroy(struct ebitmap *e);
76 int ebitmap_read(struct ebitmap *e, void *fp);
78 #endif /* _SS_EBITMAP_H_ */