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, <stephen.smalley.work@gmail.com>
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
34struct ebitmap_node {
35 struct ebitmap_node *next;
36 unsigned long maps[EBITMAP_UNIT_NUMS];
37 u32 startbit;
38};
39
40struct 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
47static inline unsigned int ebitmap_start_positive(const 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(addr: (*n)->maps, EBITMAP_SIZE);
54 if (ofs < EBITMAP_SIZE)
55 return (*n)->startbit + ofs;
56 }
57 return ebitmap_length(e);
58}
59
60static inline void ebitmap_init(struct ebitmap *e)
61{
62 memset(e, 0, sizeof(*e));
63}
64
65static inline unsigned int ebitmap_next_positive(const struct ebitmap *e,
66 struct ebitmap_node **n,
67 unsigned int bit)
68{
69 unsigned int ofs;
70
71 ofs = find_next_bit(addr: (*n)->maps, EBITMAP_SIZE, offset: 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(addr: (*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
88static inline int ebitmap_node_get_bit(const 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
100static 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
110static 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
125int ebitmap_cmp(const struct ebitmap *e1, const struct ebitmap *e2);
126int ebitmap_cpy(struct ebitmap *dst, const struct ebitmap *src);
127int ebitmap_and(struct ebitmap *dst, const struct ebitmap *e1, const struct ebitmap *e2);
128int ebitmap_contains(const struct ebitmap *e1, const struct ebitmap *e2, u32 last_e2bit);
129int ebitmap_get_bit(const struct ebitmap *e, unsigned long bit);
130int ebitmap_set_bit(struct ebitmap *e, unsigned long bit, int value);
131void ebitmap_destroy(struct ebitmap *e);
132int ebitmap_read(struct ebitmap *e, void *fp);
133int ebitmap_write(const struct ebitmap *e, void *fp);
134u32 ebitmap_hash(const struct ebitmap *e, u32 hash);
135
136#ifdef CONFIG_NETLABEL
137int ebitmap_netlbl_export(struct ebitmap *ebmap,
138 struct netlbl_lsm_catmap **catmap);
139int ebitmap_netlbl_import(struct ebitmap *ebmap,
140 struct netlbl_lsm_catmap *catmap);
141#else
142static inline int ebitmap_netlbl_export(struct ebitmap *ebmap,
143 struct netlbl_lsm_catmap **catmap)
144{
145 return -ENOMEM;
146}
147static inline int ebitmap_netlbl_import(struct ebitmap *ebmap,
148 struct netlbl_lsm_catmap *catmap)
149{
150 return -ENOMEM;
151}
152#endif
153
154#endif /* _SS_EBITMAP_H_ */
155

source code of linux/security/selinux/ss/ebitmap.h