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
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(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
60static inline void ebitmap_init(struct ebitmap *e)
61{
62	memset(e, 0, sizeof(*e));
63}
64
65static 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
88static 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
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(struct ebitmap *e1, struct ebitmap *e2);
126int ebitmap_cpy(struct ebitmap *dst, struct ebitmap *src);
127int ebitmap_and(struct ebitmap *dst, struct ebitmap *e1, struct ebitmap *e2);
128int ebitmap_contains(struct ebitmap *e1, struct ebitmap *e2, u32 last_e2bit);
129int ebitmap_get_bit(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(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