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#include <net/netlabel.h>
18
19#define MAPTYPE u64			/* portion of bitmap in each node */
20#define MAPSIZE (sizeof(MAPTYPE) * 8)	/* number of bits in node bitmap */
21#define MAPBIT  1ULL			/* a bit in the node bitmap */
22
23struct ebitmap_node {
24	u32 startbit;		/* starting position in the total bitmap */
25	MAPTYPE map;		/* this node's portion of the bitmap */
26	struct ebitmap_node *next;
27};
28
29struct ebitmap {
30	struct ebitmap_node *node;	/* first node in the bitmap */
31	u32 highbit;	/* highest position in the total bitmap */
32};
33
34#define ebitmap_length(e) ((e)->highbit)
35#define ebitmap_startbit(e) ((e)->node ? (e)->node->startbit : 0)
36
37static inline unsigned int ebitmap_start(struct ebitmap *e,
38					 struct ebitmap_node **n)
39{
40	*n = e->node;
41	return ebitmap_startbit(e);
42}
43
44static inline void ebitmap_init(struct ebitmap *e)
45{
46	memset(e, 0, sizeof(*e));
47}
48
49static inline unsigned int ebitmap_next(struct ebitmap_node **n,
50					unsigned int bit)
51{
52	if ((bit == ((*n)->startbit + MAPSIZE - 1)) &&
53	    (*n)->next) {
54		*n = (*n)->next;
55		return (*n)->startbit;
56	}
57
58	return (bit+1);
59}
60
61static inline int ebitmap_node_get_bit(struct ebitmap_node * n,
62				       unsigned int bit)
63{
64	if (n->map & (MAPBIT << (bit - n->startbit)))
65		return 1;
66	return 0;
67}
68
69#define ebitmap_for_each_bit(e, n, bit) \
70	for (bit = ebitmap_start(e, &n); bit < ebitmap_length(e); bit = ebitmap_next(&n, bit)) \
71
72int ebitmap_cmp(struct ebitmap *e1, struct ebitmap *e2);
73int ebitmap_cpy(struct ebitmap *dst, struct ebitmap *src);
74int ebitmap_contains(struct ebitmap *e1, struct ebitmap *e2);
75int ebitmap_get_bit(struct ebitmap *e, unsigned long bit);
76int ebitmap_set_bit(struct ebitmap *e, unsigned long bit, int value);
77void ebitmap_destroy(struct ebitmap *e);
78int ebitmap_read(struct ebitmap *e, void *fp);
79
80#ifdef CONFIG_NETLABEL
81int ebitmap_netlbl_export(struct ebitmap *ebmap,
82			  struct netlbl_lsm_secattr_catmap **catmap);
83int ebitmap_netlbl_import(struct ebitmap *ebmap,
84			  struct netlbl_lsm_secattr_catmap *catmap);
85#else
86static inline int ebitmap_netlbl_export(struct ebitmap *ebmap,
87				struct netlbl_lsm_secattr_catmap **catmap)
88{
89	return -ENOMEM;
90}
91static inline int ebitmap_netlbl_import(struct ebitmap *ebmap,
92				struct netlbl_lsm_secattr_catmap *catmap)
93{
94	return -ENOMEM;
95}
96#endif
97
98#endif	/* _SS_EBITMAP_H_ */
99