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
ebitmap_start_positive(struct ebitmap * e,struct ebitmap_node ** n)40 static inline unsigned int ebitmap_start_positive(struct ebitmap *e,
41 struct ebitmap_node **n)
42 {
43 unsigned int ofs;
44
45 for (*n = e->node; *n; *n = (*n)->next) {
46 ofs = find_first_bit((*n)->maps, EBITMAP_SIZE);
47 if (ofs < EBITMAP_SIZE)
48 return (*n)->startbit + ofs;
49 }
50 return ebitmap_length(e);
51 }
52
ebitmap_init(struct ebitmap * e)53 static inline void ebitmap_init(struct ebitmap *e)
54 {
55 memset(e, 0, sizeof(*e));
56 }
57
ebitmap_next_positive(struct ebitmap * e,struct ebitmap_node ** n,unsigned int bit)58 static inline unsigned int ebitmap_next_positive(struct ebitmap *e,
59 struct ebitmap_node **n,
60 unsigned int bit)
61 {
62 unsigned int ofs;
63
64 ofs = find_next_bit((*n)->maps, EBITMAP_SIZE, bit - (*n)->startbit + 1);
65 if (ofs < EBITMAP_SIZE)
66 return ofs + (*n)->startbit;
67
68 for (*n = (*n)->next; *n; *n = (*n)->next) {
69 ofs = find_first_bit((*n)->maps, EBITMAP_SIZE);
70 if (ofs < EBITMAP_SIZE)
71 return ofs + (*n)->startbit;
72 }
73 return ebitmap_length(e);
74 }
75
76 #define EBITMAP_NODE_INDEX(node, bit) \
77 (((bit) - (node)->startbit) / EBITMAP_UNIT_SIZE)
78 #define EBITMAP_NODE_OFFSET(node, bit) \
79 (((bit) - (node)->startbit) % EBITMAP_UNIT_SIZE)
80
ebitmap_node_get_bit(struct ebitmap_node * n,unsigned int bit)81 static inline int ebitmap_node_get_bit(struct ebitmap_node *n,
82 unsigned int bit)
83 {
84 unsigned int index = EBITMAP_NODE_INDEX(n, bit);
85 unsigned int ofs = EBITMAP_NODE_OFFSET(n, bit);
86
87 BUG_ON(index >= EBITMAP_UNIT_NUMS);
88 if ((n->maps[index] & (EBITMAP_BIT << ofs)))
89 return 1;
90 return 0;
91 }
92
ebitmap_node_set_bit(struct ebitmap_node * n,unsigned int bit)93 static inline void ebitmap_node_set_bit(struct ebitmap_node *n,
94 unsigned int bit)
95 {
96 unsigned int index = EBITMAP_NODE_INDEX(n, bit);
97 unsigned int ofs = EBITMAP_NODE_OFFSET(n, bit);
98
99 BUG_ON(index >= EBITMAP_UNIT_NUMS);
100 n->maps[index] |= (EBITMAP_BIT << ofs);
101 }
102
ebitmap_node_clr_bit(struct ebitmap_node * n,unsigned int bit)103 static inline void ebitmap_node_clr_bit(struct ebitmap_node *n,
104 unsigned int bit)
105 {
106 unsigned int index = EBITMAP_NODE_INDEX(n, bit);
107 unsigned int ofs = EBITMAP_NODE_OFFSET(n, bit);
108
109 BUG_ON(index >= EBITMAP_UNIT_NUMS);
110 n->maps[index] &= ~(EBITMAP_BIT << ofs);
111 }
112
113 #define ebitmap_for_each_positive_bit(e, n, bit) \
114 for (bit = ebitmap_start_positive(e, &n); \
115 bit < ebitmap_length(e); \
116 bit = ebitmap_next_positive(e, &n, bit)) \
117
118 int ebitmap_cmp(struct ebitmap *e1, struct ebitmap *e2);
119 int ebitmap_cpy(struct ebitmap *dst, struct ebitmap *src);
120 int ebitmap_contains(struct ebitmap *e1, struct ebitmap *e2);
121 int ebitmap_get_bit(struct ebitmap *e, unsigned long bit);
122 int ebitmap_set_bit(struct ebitmap *e, unsigned long bit, int value);
123 void ebitmap_destroy(struct ebitmap *e);
124 int ebitmap_read(struct ebitmap *e, void *fp);
125 int ebitmap_write(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