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
ebitmap_start_positive(struct ebitmap * e,struct ebitmap_node ** n)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
ebitmap_init(struct ebitmap * e)60 static inline void ebitmap_init(struct ebitmap *e)
61 {
62 memset(e, 0, sizeof(*e));
63 }
64
ebitmap_next_positive(struct ebitmap * e,struct ebitmap_node ** n,unsigned int bit)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
ebitmap_node_get_bit(struct ebitmap_node * n,unsigned int bit)88 static inline int ebitmap_node_get_bit(struct ebitmap_node *n,
89 unsigned int bit)
90 {
91 unsigned int index = EBITMAP_NODE_INDEX(n, bit);
92 unsigned int ofs = EBITMAP_NODE_OFFSET(n, bit);
93
94 BUG_ON(index >= EBITMAP_UNIT_NUMS);
95 if ((n->maps[index] & (EBITMAP_BIT << ofs)))
96 return 1;
97 return 0;
98 }
99
ebitmap_node_set_bit(struct ebitmap_node * n,unsigned int bit)100 static inline void ebitmap_node_set_bit(struct ebitmap_node *n,
101 unsigned int bit)
102 {
103 unsigned int index = EBITMAP_NODE_INDEX(n, bit);
104 unsigned int ofs = EBITMAP_NODE_OFFSET(n, bit);
105
106 BUG_ON(index >= EBITMAP_UNIT_NUMS);
107 n->maps[index] |= (EBITMAP_BIT << ofs);
108 }
109
ebitmap_node_clr_bit(struct ebitmap_node * n,unsigned int bit)110 static inline void ebitmap_node_clr_bit(struct ebitmap_node *n,
111 unsigned int bit)
112 {
113 unsigned int index = EBITMAP_NODE_INDEX(n, bit);
114 unsigned int ofs = EBITMAP_NODE_OFFSET(n, bit);
115
116 BUG_ON(index >= EBITMAP_UNIT_NUMS);
117 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_contains(struct ebitmap *e1, struct ebitmap *e2, u32 last_e2bit);
128 int ebitmap_get_bit(struct ebitmap *e, unsigned long bit);
129 int ebitmap_set_bit(struct ebitmap *e, unsigned long bit, int value);
130 void ebitmap_destroy(struct ebitmap *e);
131 int ebitmap_read(struct ebitmap *e, void *fp);
132 int ebitmap_write(struct ebitmap *e, void *fp);
133
134 #ifdef CONFIG_NETLABEL
135 int ebitmap_netlbl_export(struct ebitmap *ebmap,
136 struct netlbl_lsm_catmap **catmap);
137 int ebitmap_netlbl_import(struct ebitmap *ebmap,
138 struct netlbl_lsm_catmap *catmap);
139 #else
ebitmap_netlbl_export(struct ebitmap * ebmap,struct netlbl_lsm_catmap ** catmap)140 static inline int ebitmap_netlbl_export(struct ebitmap *ebmap,
141 struct netlbl_lsm_catmap **catmap)
142 {
143 return -ENOMEM;
144 }
ebitmap_netlbl_import(struct ebitmap * ebmap,struct netlbl_lsm_catmap * catmap)145 static inline int ebitmap_netlbl_import(struct ebitmap *ebmap,
146 struct netlbl_lsm_catmap *catmap)
147 {
148 return -ENOMEM;
149 }
150 #endif
151
152 #endif /* _SS_EBITMAP_H_ */
153
