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1 : : /* SPDX-License-Identifier: GPL-2.0 */
2 : : /*
3 : : * An extensible bitmap is a bitmap that supports an
4 : : * arbitrary number of bits. Extensible bitmaps are
5 : : * used to represent sets of values, such as types,
6 : : * roles, categories, and classes.
7 : : *
8 : : * Each extensible bitmap is implemented as a linked
9 : : * list of bitmap nodes, where each bitmap node has
10 : : * an explicitly specified starting bit position within
11 : : * the total bitmap.
12 : : *
13 : : * Author : Stephen Smalley, <sds@tycho.nsa.gov>
14 : : */
15 : : #ifndef _SS_EBITMAP_H_
16 : : #define _SS_EBITMAP_H_
17 : :
18 : : #include <net/netlabel.h>
19 : :
20 : : #ifdef CONFIG_64BIT
21 : : #define EBITMAP_NODE_SIZE 64
22 : : #else
23 : : #define EBITMAP_NODE_SIZE 32
24 : : #endif
25 : :
26 : : #define EBITMAP_UNIT_NUMS ((EBITMAP_NODE_SIZE-sizeof(void *)-sizeof(u32))\
27 : : / sizeof(unsigned long))
28 : : #define EBITMAP_UNIT_SIZE BITS_PER_LONG
29 : : #define EBITMAP_SIZE (EBITMAP_UNIT_NUMS * EBITMAP_UNIT_SIZE)
30 : : #define EBITMAP_BIT 1ULL
31 : : #define EBITMAP_SHIFT_UNIT_SIZE(x) \
32 : : (((x) >> EBITMAP_UNIT_SIZE / 2) >> EBITMAP_UNIT_SIZE / 2)
33 : :
34 : : struct ebitmap_node {
35 : : struct ebitmap_node *next;
36 : : unsigned long maps[EBITMAP_UNIT_NUMS];
37 : : u32 startbit;
38 : : };
39 : :
40 : : struct ebitmap {
41 : : struct ebitmap_node *node; /* first node in the bitmap */
42 : : u32 highbit; /* highest position in the total bitmap */
43 : : };
44 : :
45 : : #define ebitmap_length(e) ((e)->highbit)
46 : :
47 : : static inline unsigned int ebitmap_start_positive(struct ebitmap *e,
48 : : struct ebitmap_node **n)
49 : : {
50 : : unsigned int ofs;
51 : :
52 : : for (*n = e->node; *n; *n = (*n)->next) {
53 : : ofs = find_first_bit((*n)->maps, EBITMAP_SIZE);
54 : : if (ofs < EBITMAP_SIZE)
55 : : return (*n)->startbit + ofs;
56 : : }
57 : : return ebitmap_length(e);
58 : : }
59 : :
60 : 0 : static inline void ebitmap_init(struct ebitmap *e)
61 : : {
62 [ # # ]: 0 : memset(e, 0, sizeof(*e));
63 : : }
64 : :
65 : : static inline unsigned int ebitmap_next_positive(struct ebitmap *e,
66 : : struct ebitmap_node **n,
67 : : unsigned int bit)
68 : : {
69 : : unsigned int ofs;
70 : :
71 : : ofs = find_next_bit((*n)->maps, EBITMAP_SIZE, bit - (*n)->startbit + 1);
72 : : if (ofs < EBITMAP_SIZE)
73 : : return ofs + (*n)->startbit;
74 : :
75 : : for (*n = (*n)->next; *n; *n = (*n)->next) {
76 : : ofs = find_first_bit((*n)->maps, EBITMAP_SIZE);
77 : : if (ofs < EBITMAP_SIZE)
78 : : return ofs + (*n)->startbit;
79 : : }
80 : : return ebitmap_length(e);
81 : : }
82 : :
83 : : #define EBITMAP_NODE_INDEX(node, bit) \
84 : : (((bit) - (node)->startbit) / EBITMAP_UNIT_SIZE)
85 : : #define EBITMAP_NODE_OFFSET(node, bit) \
86 : : (((bit) - (node)->startbit) % EBITMAP_UNIT_SIZE)
87 : :
88 : 0 : static inline int ebitmap_node_get_bit(struct ebitmap_node *n,
89 : : unsigned int bit)
90 : : {
91 : 0 : unsigned int index = EBITMAP_NODE_INDEX(n, bit);
92 : 0 : unsigned int ofs = EBITMAP_NODE_OFFSET(n, bit);
93 : :
94 [ # # ]: 0 : BUG_ON(index >= EBITMAP_UNIT_NUMS);
95 : 0 : if ((n->maps[index] & (EBITMAP_BIT << ofs)))
96 : : return 1;
97 : : return 0;
98 : : }
99 : :
100 : 0 : static inline void ebitmap_node_set_bit(struct ebitmap_node *n,
101 : : unsigned int bit)
102 : : {
103 : 0 : unsigned int index = EBITMAP_NODE_INDEX(n, bit);
104 : 0 : unsigned int ofs = EBITMAP_NODE_OFFSET(n, bit);
105 : :
106 [ # # # # ]: 0 : BUG_ON(index >= EBITMAP_UNIT_NUMS);
107 [ # # ]: 0 : n->maps[index] |= (EBITMAP_BIT << ofs);
108 : 0 : }
109 : :
110 : 0 : static inline void ebitmap_node_clr_bit(struct ebitmap_node *n,
111 : : unsigned int bit)
112 : : {
113 : 0 : unsigned int index = EBITMAP_NODE_INDEX(n, bit);
114 : 0 : unsigned int ofs = EBITMAP_NODE_OFFSET(n, bit);
115 : :
116 [ # # ]: 0 : BUG_ON(index >= EBITMAP_UNIT_NUMS);
117 : 0 : n->maps[index] &= ~(EBITMAP_BIT << ofs);
118 : : }
119 : :
120 : : #define ebitmap_for_each_positive_bit(e, n, bit) \
121 : : for (bit = ebitmap_start_positive(e, &n); \
122 : : bit < ebitmap_length(e); \
123 : : bit = ebitmap_next_positive(e, &n, bit)) \
124 : :
125 : : int ebitmap_cmp(struct ebitmap *e1, struct ebitmap *e2);
126 : : int ebitmap_cpy(struct ebitmap *dst, struct ebitmap *src);
127 : : int ebitmap_and(struct ebitmap *dst, struct ebitmap *e1, struct ebitmap *e2);
128 : : int ebitmap_contains(struct ebitmap *e1, struct ebitmap *e2, u32 last_e2bit);
129 : : int ebitmap_get_bit(struct ebitmap *e, unsigned long bit);
130 : : int ebitmap_set_bit(struct ebitmap *e, unsigned long bit, int value);
131 : : void ebitmap_destroy(struct ebitmap *e);
132 : : int ebitmap_read(struct ebitmap *e, void *fp);
133 : : int ebitmap_write(struct ebitmap *e, void *fp);
134 : :
135 : : #ifdef CONFIG_NETLABEL
136 : : int ebitmap_netlbl_export(struct ebitmap *ebmap,
137 : : struct netlbl_lsm_catmap **catmap);
138 : : int ebitmap_netlbl_import(struct ebitmap *ebmap,
139 : : struct netlbl_lsm_catmap *catmap);
140 : : #else
141 : : static inline int ebitmap_netlbl_export(struct ebitmap *ebmap,
142 : : struct netlbl_lsm_catmap **catmap)
143 : : {
144 : : return -ENOMEM;
145 : : }
146 : : static inline int ebitmap_netlbl_import(struct ebitmap *ebmap,
147 : : struct netlbl_lsm_catmap *catmap)
148 : : {
149 : : return -ENOMEM;
150 : : }
151 : : #endif
152 : :
153 : : #endif /* _SS_EBITMAP_H_ */
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