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      1 /* Author : Stephen Smalley, <sds (at) epoch.ncsc.mil> */
      2 
      3 /* FLASK */
      4 
      5 /*
      6  * An extensible bitmap is a bitmap that supports an
      7  * arbitrary number of bits.  Extensible bitmaps are
      8  * used to represent sets of values, such as types,
      9  * roles, categories, and classes.
     10  *
     11  * Each extensible bitmap is implemented as a linked
     12  * list of bitmap nodes, where each bitmap node has
     13  * an explicitly specified starting bit position within
     14  * the total bitmap.
     15  */
     16 
     17 #ifndef _SEPOL_POLICYDB_EBITMAP_H_
     18 #define _SEPOL_POLICYDB_EBITMAP_H_
     19 
     20 #include <stdint.h>
     21 #include <string.h>
     22 #include <sys/cdefs.h>
     23 
     24 __BEGIN_DECLS
     25 
     26 #define MAPTYPE uint64_t	/* portion of bitmap in each node */
     27 #define MAPSIZE (sizeof(MAPTYPE) * 8)	/* number of bits in node bitmap */
     28 #define MAPBIT  1ULL		/* a bit in the node bitmap */
     29 
     30 typedef struct ebitmap_node {
     31 	uint32_t startbit;	/* starting position in the total bitmap */
     32 	MAPTYPE map;		/* this node's portion of the bitmap */
     33 	struct ebitmap_node *next;
     34 } ebitmap_node_t;
     35 
     36 typedef struct ebitmap {
     37 	ebitmap_node_t *node;	/* first node in the bitmap */
     38 	uint32_t highbit;	/* highest position in the total bitmap */
     39 } ebitmap_t;
     40 
     41 #define ebitmap_length(e) ((e)->highbit)
     42 #define ebitmap_startbit(e) ((e)->node ? (e)->node->startbit : 0)
     43 #define ebitmap_startnode(e) ((e)->node)
     44 
     45 static inline unsigned int ebitmap_start(const ebitmap_t * e,
     46 					 ebitmap_node_t ** n)
     47 {
     48 
     49 	*n = e->node;
     50 	return ebitmap_startbit(e);
     51 }
     52 
     53 static inline void ebitmap_init(ebitmap_t * e)
     54 {
     55 	memset(e, 0, sizeof(*e));
     56 }
     57 
     58 static inline unsigned int ebitmap_next(ebitmap_node_t ** n, unsigned int bit)
     59 {
     60 	if ((bit == ((*n)->startbit + MAPSIZE - 1)) && (*n)->next) {
     61 		*n = (*n)->next;
     62 		return (*n)->startbit;
     63 	}
     64 
     65 	return (bit + 1);
     66 }
     67 
     68 static inline int ebitmap_node_get_bit(ebitmap_node_t * n, unsigned int bit)
     69 {
     70 	if (n->map & (MAPBIT << (bit - n->startbit)))
     71 		return 1;
     72 	return 0;
     73 }
     74 
     75 #define ebitmap_for_each_bit(e, n, bit) \
     76 	for (bit = ebitmap_start(e, &n); bit < ebitmap_length(e); bit = ebitmap_next(&n, bit)) \
     77 
     78 extern int ebitmap_cmp(const ebitmap_t * e1, const ebitmap_t * e2);
     79 extern int ebitmap_or(ebitmap_t * dst, const ebitmap_t * e1, const ebitmap_t * e2);
     80 extern int ebitmap_union(ebitmap_t * dst, const ebitmap_t * e1);
     81 extern int ebitmap_and(ebitmap_t *dst, ebitmap_t *e1, ebitmap_t *e2);
     82 extern int ebitmap_xor(ebitmap_t *dst, ebitmap_t *e1, ebitmap_t *e2);
     83 extern int ebitmap_not(ebitmap_t *dst, ebitmap_t *e1, unsigned int maxbit);
     84 extern int ebitmap_andnot(ebitmap_t *dst, ebitmap_t *e1, ebitmap_t *e2, unsigned int maxbit);
     85 extern unsigned int ebitmap_cardinality(ebitmap_t *e1);
     86 extern int ebitmap_hamming_distance(ebitmap_t * e1, ebitmap_t * e2);
     87 extern int ebitmap_cpy(ebitmap_t * dst, const ebitmap_t * src);
     88 extern int ebitmap_contains(const ebitmap_t * e1, const ebitmap_t * e2);
     89 extern int ebitmap_get_bit(const ebitmap_t * e, unsigned int bit);
     90 extern int ebitmap_set_bit(ebitmap_t * e, unsigned int bit, int value);
     91 extern void ebitmap_destroy(ebitmap_t * e);
     92 extern int ebitmap_read(ebitmap_t * e, void *fp);
     93 
     94 __END_DECLS
     95 #endif				/* _EBITMAP_H_ */
     96 
     97 /* FLASK */
     98