Branch data Line data Source code
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 : : #ifdef CONFIG_64BIT
20 : : #define EBITMAP_NODE_SIZE 64
21 : : #else
22 : : #define EBITMAP_NODE_SIZE 32
23 : : #endif
24 : :
25 : : #define EBITMAP_UNIT_NUMS ((EBITMAP_NODE_SIZE-sizeof(void *)-sizeof(u32))\
26 : : / sizeof(unsigned long))
27 : : #define EBITMAP_UNIT_SIZE BITS_PER_LONG
28 : : #define EBITMAP_SIZE (EBITMAP_UNIT_NUMS * EBITMAP_UNIT_SIZE)
29 : : #define EBITMAP_BIT 1ULL
30 : : #define EBITMAP_SHIFT_UNIT_SIZE(x) \
31 : : (((x) >> EBITMAP_UNIT_SIZE / 2) >> EBITMAP_UNIT_SIZE / 2)
32 : :
33 : : struct ebitmap_node {
34 : : struct ebitmap_node *next;
35 : : unsigned long maps[EBITMAP_UNIT_NUMS];
36 : : u32 startbit;
37 : : };
38 : :
39 : : struct ebitmap {
40 : : struct ebitmap_node *node; /* first node in the bitmap */
41 : : u32 highbit; /* highest position in the total bitmap */
42 : : };
43 : :
44 : : #define ebitmap_length(e) ((e)->highbit)
45 : :
46 : : static inline unsigned int ebitmap_start_positive(struct ebitmap *e,
47 : : struct ebitmap_node **n)
48 : : {
49 : : unsigned int ofs;
50 : :
51 [ # # ][ # # ]: 0 : for (*n = e->node; *n; *n = (*n)->next) {
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ]
52 : 0 : ofs = find_first_bit((*n)->maps, EBITMAP_SIZE);
53 [ # # # # : 0 : if (ofs < EBITMAP_SIZE)
# # # # ]
54 : 0 : return (*n)->startbit + ofs;
55 : : }
56 : 0 : return ebitmap_length(e);
57 : : }
58 : :
59 : : static inline void ebitmap_init(struct ebitmap *e)
60 : : {
61 : 0 : memset(e, 0, sizeof(*e));
62 : : }
63 : :
64 : : static inline unsigned int ebitmap_next_positive(struct ebitmap *e,
65 : : struct ebitmap_node **n,
66 : : unsigned int bit)
67 : : {
68 : : unsigned int ofs;
69 : :
70 : 0 : ofs = find_next_bit((*n)->maps, EBITMAP_SIZE, bit - (*n)->startbit + 1);
71 [ # # # # : 0 : if (ofs < EBITMAP_SIZE)
# # # # ]
72 : 0 : return ofs + (*n)->startbit;
73 : :
74 [ # # ][ # # ]: 0 : for (*n = (*n)->next; *n; *n = (*n)->next) {
[ # # ][ # # ]
75 : 0 : ofs = find_first_bit((*n)->maps, EBITMAP_SIZE);
76 [ # # # # : 0 : if (ofs < EBITMAP_SIZE)
# # # # ]
77 : 0 : return ofs + (*n)->startbit;
78 : : }
79 : 0 : return ebitmap_length(e);
80 : : }
81 : :
82 : : #define EBITMAP_NODE_INDEX(node, bit) \
83 : : (((bit) - (node)->startbit) / EBITMAP_UNIT_SIZE)
84 : : #define EBITMAP_NODE_OFFSET(node, bit) \
85 : : (((bit) - (node)->startbit) % EBITMAP_UNIT_SIZE)
86 : :
87 : : static inline int ebitmap_node_get_bit(struct ebitmap_node *n,
88 : : unsigned int bit)
89 : : {
90 : 0 : unsigned int index = EBITMAP_NODE_INDEX(n, bit);
91 : 0 : unsigned int ofs = EBITMAP_NODE_OFFSET(n, bit);
92 : :
93 [ # # ]: 0 : BUG_ON(index >= EBITMAP_UNIT_NUMS);
94 [ # # ]: 0 : if ((n->maps[index] & (EBITMAP_BIT << ofs)))
95 : : return 1;
96 : : return 0;
97 : : }
98 : :
99 : : static inline void ebitmap_node_set_bit(struct ebitmap_node *n,
100 : : unsigned int bit)
101 : : {
102 : 0 : unsigned int index = EBITMAP_NODE_INDEX(n, bit);
103 : 0 : unsigned int ofs = EBITMAP_NODE_OFFSET(n, bit);
104 : :
105 [ # # ][ # # ]: 0 : BUG_ON(index >= EBITMAP_UNIT_NUMS);
106 : 0 : n->maps[index] |= (EBITMAP_BIT << ofs);
107 : : }
108 : :
109 : : static inline void ebitmap_node_clr_bit(struct ebitmap_node *n,
110 : : unsigned int bit)
111 : : {
112 : 0 : unsigned int index = EBITMAP_NODE_INDEX(n, bit);
113 : 0 : unsigned int ofs = EBITMAP_NODE_OFFSET(n, bit);
114 : :
115 [ # # ]: 0 : BUG_ON(index >= EBITMAP_UNIT_NUMS);
116 : 0 : n->maps[index] &= ~(EBITMAP_BIT << ofs);
117 : : }
118 : :
119 : : #define ebitmap_for_each_positive_bit(e, n, bit) \
120 : : for (bit = ebitmap_start_positive(e, &n); \
121 : : bit < ebitmap_length(e); \
122 : : bit = ebitmap_next_positive(e, &n, bit)) \
123 : :
124 : : int ebitmap_cmp(struct ebitmap *e1, struct ebitmap *e2);
125 : : int ebitmap_cpy(struct ebitmap *dst, struct ebitmap *src);
126 : : int ebitmap_contains(struct ebitmap *e1, struct ebitmap *e2, u32 last_e2bit);
127 : : int ebitmap_get_bit(struct ebitmap *e, unsigned long bit);
128 : : int ebitmap_set_bit(struct ebitmap *e, unsigned long bit, int value);
129 : : void ebitmap_destroy(struct ebitmap *e);
130 : : int ebitmap_read(struct ebitmap *e, void *fp);
131 : : int ebitmap_write(struct ebitmap *e, void *fp);
132 : :
133 : : #ifdef CONFIG_NETLABEL
134 : : int ebitmap_netlbl_export(struct ebitmap *ebmap,
135 : : struct netlbl_lsm_secattr_catmap **catmap);
136 : : int ebitmap_netlbl_import(struct ebitmap *ebmap,
137 : : struct netlbl_lsm_secattr_catmap *catmap);
138 : : #else
139 : : static inline int ebitmap_netlbl_export(struct ebitmap *ebmap,
140 : : struct netlbl_lsm_secattr_catmap **catmap)
141 : : {
142 : : return -ENOMEM;
143 : : }
144 : : static inline int ebitmap_netlbl_import(struct ebitmap *ebmap,
145 : : struct netlbl_lsm_secattr_catmap *catmap)
146 : : {
147 : : return -ENOMEM;
148 : : }
149 : : #endif
150 : :
151 : : #endif /* _SS_EBITMAP_H_ */
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