1 /* 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. 6 * 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 10 * the total bitmap. 11 * 12 * Author : Stephen Smalley, <sds@epoch.ncsc.mil> 13 */ 14 #ifndef _SS_EBITMAP_H_ 15 #define _SS_EBITMAP_H_ 16 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 */ 20 21 struct ebitmap_node { 22 u32 startbit; /* starting position in the total bitmap */ 23 MAPTYPE map; /* this node's portion of the bitmap */ 24 struct ebitmap_node *next; 25 }; 26 27 struct ebitmap { 28 struct ebitmap_node *node; /* first node in the bitmap */ 29 u32 highbit; /* highest position in the total bitmap */ 30 }; 31 32 #define ebitmap_length(e) ((e)->highbit) 33 #define ebitmap_startbit(e) ((e)->node ? (e)->node->startbit : 0) 34 35 static inline void ebitmap_init(struct ebitmap *e) 36 { 37 memset(e, 0, sizeof(*e)); 38 } 39 40 int ebitmap_cmp(struct ebitmap *e1, struct ebitmap *e2); 41 int ebitmap_cpy(struct ebitmap *dst, struct ebitmap *src); 42 int ebitmap_contains(struct ebitmap *e1, struct ebitmap *e2); 43 int ebitmap_get_bit(struct ebitmap *e, unsigned long bit); 44 int ebitmap_set_bit(struct ebitmap *e, unsigned long bit, int value); 45 void ebitmap_destroy(struct ebitmap *e); 46 int ebitmap_read(struct ebitmap *e, void *fp); 47 48 #endif /* _SS_EBITMAP_H_ */ 49