security/selinux/ss/ebitmap.h

   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_ */