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 EBITMAP_UNIT_NUMS ((32 - sizeof(void *) - sizeof(u32)) \
20 / sizeof(unsigned long))
21 #define EBITMAP_UNIT_SIZE BITS_PER_LONG
22 #define EBITMAP_SIZE (EBITMAP_UNIT_NUMS * EBITMAP_UNIT_SIZE)
23 #define EBITMAP_BIT 1ULL
24 #define EBITMAP_SHIFT_UNIT_SIZE(x) \
25 (((x) >> EBITMAP_UNIT_SIZE / 2) >> EBITMAP_UNIT_SIZE / 2)
26
27 struct ebitmap_node {
28 struct ebitmap_node *next;
29 unsigned long maps[EBITMAP_UNIT_NUMS];
30 u32 startbit;
31 };
32
33 struct ebitmap {
34 struct ebitmap_node *node; /* first node in the bitmap */
35 u32 highbit; /* highest position in the total bitmap */
36 };
37
38 #define ebitmap_length(e) ((e)->highbit)
39 #define ebitmap_startbit(e) ((e)->node ? (e)->node->startbit : 0)
40
ebitmap_start_positive(struct ebitmap * e,struct ebitmap_node ** n)41 static inline unsigned int ebitmap_start_positive(struct ebitmap *e,
42 struct ebitmap_node **n)
43 {
44 unsigned int ofs;
45
46 for (*n = e->node; *n; *n = (*n)->next) {
47 ofs = find_first_bit((*n)->maps, EBITMAP_SIZE);
48 if (ofs < EBITMAP_SIZE)
49 return (*n)->startbit + ofs;
50 }
51 return ebitmap_length(e);
52 }
53
ebitmap_init(struct ebitmap * e)54 static inline void ebitmap_init(struct ebitmap *e)
55 {
56 memset(e, 0, sizeof(*e));
57 }
58
ebitmap_next_positive(struct ebitmap * e,struct ebitmap_node ** n,unsigned int bit)59 static inline unsigned int ebitmap_next_positive(struct ebitmap *e,
60 struct ebitmap_node **n,
61 unsigned int bit)
62 {
63 unsigned int ofs;
64
65 ofs = find_next_bit((*n)->maps, EBITMAP_SIZE, bit - (*n)->startbit + 1);
66 if (ofs < EBITMAP_SIZE)
67 return ofs + (*n)->startbit;
68
69 for (*n = (*n)->next; *n; *n = (*n)->next) {
70 ofs = find_first_bit((*n)->maps, EBITMAP_SIZE);
71 if (ofs < EBITMAP_SIZE)
72 return ofs + (*n)->startbit;
73 }
74 return ebitmap_length(e);
75 }
76
77 #define EBITMAP_NODE_INDEX(node, bit) \
78 (((bit) - (node)->startbit) / EBITMAP_UNIT_SIZE)
79 #define EBITMAP_NODE_OFFSET(node, bit) \
80 (((bit) - (node)->startbit) % EBITMAP_UNIT_SIZE)
81
ebitmap_node_get_bit(struct ebitmap_node * n,unsigned int bit)82 static inline int ebitmap_node_get_bit(struct ebitmap_node *n,
83 unsigned int bit)
84 {
85 unsigned int index = EBITMAP_NODE_INDEX(n, bit);
86 unsigned int ofs = EBITMAP_NODE_OFFSET(n, bit);
87
88 BUG_ON(index >= EBITMAP_UNIT_NUMS);
89 if ((n->maps[index] & (EBITMAP_BIT << ofs)))
90 return 1;
91 return 0;
92 }
93
ebitmap_node_set_bit(struct ebitmap_node * n,unsigned int bit)94 static inline void ebitmap_node_set_bit(struct ebitmap_node *n,
95 unsigned int bit)
96 {
97 unsigned int index = EBITMAP_NODE_INDEX(n, bit);
98 unsigned int ofs = EBITMAP_NODE_OFFSET(n, bit);
99
100 BUG_ON(index >= EBITMAP_UNIT_NUMS);
101 n->maps[index] |= (EBITMAP_BIT << ofs);
102 }
103
ebitmap_node_clr_bit(struct ebitmap_node * n,unsigned int bit)104 static inline void ebitmap_node_clr_bit(struct ebitmap_node *n,
105 unsigned int bit)
106 {
107 unsigned int index = EBITMAP_NODE_INDEX(n, bit);
108 unsigned int ofs = EBITMAP_NODE_OFFSET(n, bit);
109
110 BUG_ON(index >= EBITMAP_UNIT_NUMS);
111 n->maps[index] &= ~(EBITMAP_BIT << ofs);
112 }
113
114 #define ebitmap_for_each_positive_bit(e, n, bit) \
115 for (bit = ebitmap_start_positive(e, &n); \
116 bit < ebitmap_length(e); \
117 bit = ebitmap_next_positive(e, &n, bit)) \
118
119 int ebitmap_cmp(struct ebitmap *e1, struct ebitmap *e2);
120 int ebitmap_cpy(struct ebitmap *dst, struct ebitmap *src);
121 int ebitmap_contains(struct ebitmap *e1, struct ebitmap *e2);
122 int ebitmap_get_bit(struct ebitmap *e, unsigned long bit);
123 int ebitmap_set_bit(struct ebitmap *e, unsigned long bit, int value);
124 void ebitmap_destroy(struct ebitmap *e);
125 int ebitmap_read(struct ebitmap *e, void *fp);
126
127 #ifdef CONFIG_NETLABEL
128 int ebitmap_netlbl_export(struct ebitmap *ebmap,
129 struct netlbl_lsm_secattr_catmap **catmap);
130 int ebitmap_netlbl_import(struct ebitmap *ebmap,
131 struct netlbl_lsm_secattr_catmap *catmap);
132 #else
ebitmap_netlbl_export(struct ebitmap * ebmap,struct netlbl_lsm_secattr_catmap ** catmap)133 static inline int ebitmap_netlbl_export(struct ebitmap *ebmap,
134 struct netlbl_lsm_secattr_catmap **catmap)
135 {
136 return -ENOMEM;
137 }
ebitmap_netlbl_import(struct ebitmap * ebmap,struct netlbl_lsm_secattr_catmap * catmap)138 static inline int ebitmap_netlbl_import(struct ebitmap *ebmap,
139 struct netlbl_lsm_secattr_catmap *catmap)
140 {
141 return -ENOMEM;
142 }
143 #endif
144
145 #endif /* _SS_EBITMAP_H_ */
146