1. 根目录:
2. security
3. selinux
4. ss
5. ebitmap.h

/*
 * An extensible bitmap is a bitmap that supports an
 * arbitrary number of bits.  Extensible bitmaps are
 * used to represent sets of values, such as types,
 * roles, categories, and classes.
 *
 * Each extensible bitmap is implemented as a linked
 * list of bitmap nodes, where each bitmap node has
 * an explicitly specified starting bit position within
 * the total bitmap.
 *
 * Author : Stephen Smalley, <sds@epoch.ncsc.mil>
 */
#ifndef _SS_EBITMAP_H_
#define _SS_EBITMAP_H_

#include <net/netlabel.h>

#ifdef CONFIG_64BIT
#define	EBITMAP_NODE_SIZE	64
#else
#define	EBITMAP_NODE_SIZE	32
#endif

#define EBITMAP_UNIT_NUMS	((EBITMAP_NODE_SIZE-sizeof(void *)-sizeof(u32))\
					/ sizeof(unsigned long))
#define EBITMAP_UNIT_SIZE	BITS_PER_LONG
#define EBITMAP_SIZE		(EBITMAP_UNIT_NUMS * EBITMAP_UNIT_SIZE)
#define EBITMAP_BIT		1ULL
#define EBITMAP_SHIFT_UNIT_SIZE(x)					\
	(((x) >> EBITMAP_UNIT_SIZE / 2) >> EBITMAP_UNIT_SIZE / 2)

struct ebitmap_node {
	struct ebitmap_node *next;
	unsigned long maps[EBITMAP_UNIT_NUMS];
	u32 startbit;
};

struct ebitmap {
	struct ebitmap_node *node;	/* first node in the bitmap */
	u32 highbit;	/* highest position in the total bitmap */
};

#define ebitmap_length(e) ((e)->highbit)

static inline unsigned int ebitmap_start_positive(struct ebitmap *e,
						  struct ebitmap_node **n)
{
	unsigned int ofs;

	for (*n = e->node; *n; *n = (*n)->next) {
		ofs = find_first_bit((*n)->maps, EBITMAP_SIZE);
		if (ofs < EBITMAP_SIZE)
			return (*n)->startbit + ofs;
	}
	return ebitmap_length(e);
}

static inline void ebitmap_init(struct ebitmap *e)
{
	memset(e, 0, sizeof(*e));
}

static inline unsigned int ebitmap_next_positive(struct ebitmap *e,
						 struct ebitmap_node **n,
						 unsigned int bit)
{
	unsigned int ofs;

	ofs = find_next_bit((*n)->maps, EBITMAP_SIZE, bit - (*n)->startbit + 1);
	if (ofs < EBITMAP_SIZE)
		return ofs + (*n)->startbit;

	for (*n = (*n)->next; *n; *n = (*n)->next) {
		ofs = find_first_bit((*n)->maps, EBITMAP_SIZE);
		if (ofs < EBITMAP_SIZE)
			return ofs + (*n)->startbit;
	}
	return ebitmap_length(e);
}

#define EBITMAP_NODE_INDEX(node, bit)	\
	(((bit) - (node)->startbit) / EBITMAP_UNIT_SIZE)
#define EBITMAP_NODE_OFFSET(node, bit)	\
	(((bit) - (node)->startbit) % EBITMAP_UNIT_SIZE)

static inline int ebitmap_node_get_bit(struct ebitmap_node *n,
				       unsigned int bit)
{
	unsigned int index = EBITMAP_NODE_INDEX(n, bit);
	unsigned int ofs = EBITMAP_NODE_OFFSET(n, bit);

	BUG_ON(index >= EBITMAP_UNIT_NUMS);
	if ((n->maps[index] & (EBITMAP_BIT << ofs)))
		return 1;
	return 0;
}

static inline void ebitmap_node_set_bit(struct ebitmap_node *n,
					unsigned int bit)
{
	unsigned int index = EBITMAP_NODE_INDEX(n, bit);
	unsigned int ofs = EBITMAP_NODE_OFFSET(n, bit);

	BUG_ON(index >= EBITMAP_UNIT_NUMS);
	n->maps[index] |= (EBITMAP_BIT << ofs);
}

static inline void ebitmap_node_clr_bit(struct ebitmap_node *n,
					unsigned int bit)
{
	unsigned int index = EBITMAP_NODE_INDEX(n, bit);
	unsigned int ofs = EBITMAP_NODE_OFFSET(n, bit);

	BUG_ON(index >= EBITMAP_UNIT_NUMS);
	n->maps[index] &= ~(EBITMAP_BIT << ofs);
}

#define ebitmap_for_each_positive_bit(e, n, bit)	\
	for (bit = ebitmap_start_positive(e, &n);	\
	     bit < ebitmap_length(e);			\
	     bit = ebitmap_next_positive(e, &n, bit))	\

int ebitmap_cmp(struct ebitmap *e1, struct ebitmap *e2);
int ebitmap_cpy(struct ebitmap *dst, struct ebitmap *src);
int ebitmap_contains(struct ebitmap *e1, struct ebitmap *e2, u32 last_e2bit);
int ebitmap_get_bit(struct ebitmap *e, unsigned long bit);
int ebitmap_set_bit(struct ebitmap *e, unsigned long bit, int value);
void ebitmap_destroy(struct ebitmap *e);
int ebitmap_read(struct ebitmap *e, void *fp);
int ebitmap_write(struct ebitmap *e, void *fp);

#ifdef CONFIG_NETLABEL
int ebitmap_netlbl_export(struct ebitmap *ebmap,
			  struct netlbl_lsm_catmap **catmap);
int ebitmap_netlbl_import(struct ebitmap *ebmap,
			  struct netlbl_lsm_catmap *catmap);
#else
static inline int ebitmap_netlbl_export(struct ebitmap *ebmap,
					struct netlbl_lsm_catmap **catmap)
{
	return -ENOMEM;
}
static inline int ebitmap_netlbl_import(struct ebitmap *ebmap,
					struct netlbl_lsm_catmap *catmap)
{
	return -ENOMEM;
}
#endif

#endif	/* _SS_EBITMAP_H_ */
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151