xref: /OK3568_Linux_fs/kernel/security/selinux/ss/ebitmap.h (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun /* SPDX-License-Identifier: GPL-2.0 */
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun  * An extensible bitmap is a bitmap that supports an
4*4882a593Smuzhiyun  * arbitrary number of bits.  Extensible bitmaps are
5*4882a593Smuzhiyun  * used to represent sets of values, such as types,
6*4882a593Smuzhiyun  * roles, categories, and classes.
7*4882a593Smuzhiyun  *
8*4882a593Smuzhiyun  * Each extensible bitmap is implemented as a linked
9*4882a593Smuzhiyun  * list of bitmap nodes, where each bitmap node has
10*4882a593Smuzhiyun  * an explicitly specified starting bit position within
11*4882a593Smuzhiyun  * the total bitmap.
12*4882a593Smuzhiyun  *
13*4882a593Smuzhiyun  * Author : Stephen Smalley, <sds@tycho.nsa.gov>
14*4882a593Smuzhiyun  */
15*4882a593Smuzhiyun #ifndef _SS_EBITMAP_H_
16*4882a593Smuzhiyun #define _SS_EBITMAP_H_
17*4882a593Smuzhiyun 
18*4882a593Smuzhiyun #include <net/netlabel.h>
19*4882a593Smuzhiyun 
20*4882a593Smuzhiyun #ifdef CONFIG_64BIT
21*4882a593Smuzhiyun #define	EBITMAP_NODE_SIZE	64
22*4882a593Smuzhiyun #else
23*4882a593Smuzhiyun #define	EBITMAP_NODE_SIZE	32
24*4882a593Smuzhiyun #endif
25*4882a593Smuzhiyun 
26*4882a593Smuzhiyun #define EBITMAP_UNIT_NUMS	((EBITMAP_NODE_SIZE-sizeof(void *)-sizeof(u32))\
27*4882a593Smuzhiyun 					/ sizeof(unsigned long))
28*4882a593Smuzhiyun #define EBITMAP_UNIT_SIZE	BITS_PER_LONG
29*4882a593Smuzhiyun #define EBITMAP_SIZE		(EBITMAP_UNIT_NUMS * EBITMAP_UNIT_SIZE)
30*4882a593Smuzhiyun #define EBITMAP_BIT		1ULL
31*4882a593Smuzhiyun #define EBITMAP_SHIFT_UNIT_SIZE(x)					\
32*4882a593Smuzhiyun 	(((x) >> EBITMAP_UNIT_SIZE / 2) >> EBITMAP_UNIT_SIZE / 2)
33*4882a593Smuzhiyun 
34*4882a593Smuzhiyun struct ebitmap_node {
35*4882a593Smuzhiyun 	struct ebitmap_node *next;
36*4882a593Smuzhiyun 	unsigned long maps[EBITMAP_UNIT_NUMS];
37*4882a593Smuzhiyun 	u32 startbit;
38*4882a593Smuzhiyun };
39*4882a593Smuzhiyun 
40*4882a593Smuzhiyun struct ebitmap {
41*4882a593Smuzhiyun 	struct ebitmap_node *node;	/* first node in the bitmap */
42*4882a593Smuzhiyun 	u32 highbit;	/* highest position in the total bitmap */
43*4882a593Smuzhiyun };
44*4882a593Smuzhiyun 
45*4882a593Smuzhiyun #define ebitmap_length(e) ((e)->highbit)
46*4882a593Smuzhiyun 
ebitmap_start_positive(struct ebitmap * e,struct ebitmap_node ** n)47*4882a593Smuzhiyun static inline unsigned int ebitmap_start_positive(struct ebitmap *e,
48*4882a593Smuzhiyun 						  struct ebitmap_node **n)
49*4882a593Smuzhiyun {
50*4882a593Smuzhiyun 	unsigned int ofs;
51*4882a593Smuzhiyun 
52*4882a593Smuzhiyun 	for (*n = e->node; *n; *n = (*n)->next) {
53*4882a593Smuzhiyun 		ofs = find_first_bit((*n)->maps, EBITMAP_SIZE);
54*4882a593Smuzhiyun 		if (ofs < EBITMAP_SIZE)
55*4882a593Smuzhiyun 			return (*n)->startbit + ofs;
56*4882a593Smuzhiyun 	}
57*4882a593Smuzhiyun 	return ebitmap_length(e);
58*4882a593Smuzhiyun }
59*4882a593Smuzhiyun 
ebitmap_init(struct ebitmap * e)60*4882a593Smuzhiyun static inline void ebitmap_init(struct ebitmap *e)
61*4882a593Smuzhiyun {
62*4882a593Smuzhiyun 	memset(e, 0, sizeof(*e));
63*4882a593Smuzhiyun }
64*4882a593Smuzhiyun 
ebitmap_next_positive(struct ebitmap * e,struct ebitmap_node ** n,unsigned int bit)65*4882a593Smuzhiyun static inline unsigned int ebitmap_next_positive(struct ebitmap *e,
66*4882a593Smuzhiyun 						 struct ebitmap_node **n,
67*4882a593Smuzhiyun 						 unsigned int bit)
68*4882a593Smuzhiyun {
69*4882a593Smuzhiyun 	unsigned int ofs;
70*4882a593Smuzhiyun 
71*4882a593Smuzhiyun 	ofs = find_next_bit((*n)->maps, EBITMAP_SIZE, bit - (*n)->startbit + 1);
72*4882a593Smuzhiyun 	if (ofs < EBITMAP_SIZE)
73*4882a593Smuzhiyun 		return ofs + (*n)->startbit;
74*4882a593Smuzhiyun 
75*4882a593Smuzhiyun 	for (*n = (*n)->next; *n; *n = (*n)->next) {
76*4882a593Smuzhiyun 		ofs = find_first_bit((*n)->maps, EBITMAP_SIZE);
77*4882a593Smuzhiyun 		if (ofs < EBITMAP_SIZE)
78*4882a593Smuzhiyun 			return ofs + (*n)->startbit;
79*4882a593Smuzhiyun 	}
80*4882a593Smuzhiyun 	return ebitmap_length(e);
81*4882a593Smuzhiyun }
82*4882a593Smuzhiyun 
83*4882a593Smuzhiyun #define EBITMAP_NODE_INDEX(node, bit)	\
84*4882a593Smuzhiyun 	(((bit) - (node)->startbit) / EBITMAP_UNIT_SIZE)
85*4882a593Smuzhiyun #define EBITMAP_NODE_OFFSET(node, bit)	\
86*4882a593Smuzhiyun 	(((bit) - (node)->startbit) % EBITMAP_UNIT_SIZE)
87*4882a593Smuzhiyun 
ebitmap_node_get_bit(struct ebitmap_node * n,unsigned int bit)88*4882a593Smuzhiyun static inline int ebitmap_node_get_bit(struct ebitmap_node *n,
89*4882a593Smuzhiyun 				       unsigned int bit)
90*4882a593Smuzhiyun {
91*4882a593Smuzhiyun 	unsigned int index = EBITMAP_NODE_INDEX(n, bit);
92*4882a593Smuzhiyun 	unsigned int ofs = EBITMAP_NODE_OFFSET(n, bit);
93*4882a593Smuzhiyun 
94*4882a593Smuzhiyun 	BUG_ON(index >= EBITMAP_UNIT_NUMS);
95*4882a593Smuzhiyun 	if ((n->maps[index] & (EBITMAP_BIT << ofs)))
96*4882a593Smuzhiyun 		return 1;
97*4882a593Smuzhiyun 	return 0;
98*4882a593Smuzhiyun }
99*4882a593Smuzhiyun 
ebitmap_node_set_bit(struct ebitmap_node * n,unsigned int bit)100*4882a593Smuzhiyun static inline void ebitmap_node_set_bit(struct ebitmap_node *n,
101*4882a593Smuzhiyun 					unsigned int bit)
102*4882a593Smuzhiyun {
103*4882a593Smuzhiyun 	unsigned int index = EBITMAP_NODE_INDEX(n, bit);
104*4882a593Smuzhiyun 	unsigned int ofs = EBITMAP_NODE_OFFSET(n, bit);
105*4882a593Smuzhiyun 
106*4882a593Smuzhiyun 	BUG_ON(index >= EBITMAP_UNIT_NUMS);
107*4882a593Smuzhiyun 	n->maps[index] |= (EBITMAP_BIT << ofs);
108*4882a593Smuzhiyun }
109*4882a593Smuzhiyun 
ebitmap_node_clr_bit(struct ebitmap_node * n,unsigned int bit)110*4882a593Smuzhiyun static inline void ebitmap_node_clr_bit(struct ebitmap_node *n,
111*4882a593Smuzhiyun 					unsigned int bit)
112*4882a593Smuzhiyun {
113*4882a593Smuzhiyun 	unsigned int index = EBITMAP_NODE_INDEX(n, bit);
114*4882a593Smuzhiyun 	unsigned int ofs = EBITMAP_NODE_OFFSET(n, bit);
115*4882a593Smuzhiyun 
116*4882a593Smuzhiyun 	BUG_ON(index >= EBITMAP_UNIT_NUMS);
117*4882a593Smuzhiyun 	n->maps[index] &= ~(EBITMAP_BIT << ofs);
118*4882a593Smuzhiyun }
119*4882a593Smuzhiyun 
120*4882a593Smuzhiyun #define ebitmap_for_each_positive_bit(e, n, bit)	\
121*4882a593Smuzhiyun 	for (bit = ebitmap_start_positive(e, &n);	\
122*4882a593Smuzhiyun 	     bit < ebitmap_length(e);			\
123*4882a593Smuzhiyun 	     bit = ebitmap_next_positive(e, &n, bit))	\
124*4882a593Smuzhiyun 
125*4882a593Smuzhiyun int ebitmap_cmp(struct ebitmap *e1, struct ebitmap *e2);
126*4882a593Smuzhiyun int ebitmap_cpy(struct ebitmap *dst, struct ebitmap *src);
127*4882a593Smuzhiyun int ebitmap_and(struct ebitmap *dst, struct ebitmap *e1, struct ebitmap *e2);
128*4882a593Smuzhiyun int ebitmap_contains(struct ebitmap *e1, struct ebitmap *e2, u32 last_e2bit);
129*4882a593Smuzhiyun int ebitmap_get_bit(struct ebitmap *e, unsigned long bit);
130*4882a593Smuzhiyun int ebitmap_set_bit(struct ebitmap *e, unsigned long bit, int value);
131*4882a593Smuzhiyun void ebitmap_destroy(struct ebitmap *e);
132*4882a593Smuzhiyun int ebitmap_read(struct ebitmap *e, void *fp);
133*4882a593Smuzhiyun int ebitmap_write(struct ebitmap *e, void *fp);
134*4882a593Smuzhiyun u32 ebitmap_hash(const struct ebitmap *e, u32 hash);
135*4882a593Smuzhiyun 
136*4882a593Smuzhiyun #ifdef CONFIG_NETLABEL
137*4882a593Smuzhiyun int ebitmap_netlbl_export(struct ebitmap *ebmap,
138*4882a593Smuzhiyun 			  struct netlbl_lsm_catmap **catmap);
139*4882a593Smuzhiyun int ebitmap_netlbl_import(struct ebitmap *ebmap,
140*4882a593Smuzhiyun 			  struct netlbl_lsm_catmap *catmap);
141*4882a593Smuzhiyun #else
ebitmap_netlbl_export(struct ebitmap * ebmap,struct netlbl_lsm_catmap ** catmap)142*4882a593Smuzhiyun static inline int ebitmap_netlbl_export(struct ebitmap *ebmap,
143*4882a593Smuzhiyun 					struct netlbl_lsm_catmap **catmap)
144*4882a593Smuzhiyun {
145*4882a593Smuzhiyun 	return -ENOMEM;
146*4882a593Smuzhiyun }
ebitmap_netlbl_import(struct ebitmap * ebmap,struct netlbl_lsm_catmap * catmap)147*4882a593Smuzhiyun static inline int ebitmap_netlbl_import(struct ebitmap *ebmap,
148*4882a593Smuzhiyun 					struct netlbl_lsm_catmap *catmap)
149*4882a593Smuzhiyun {
150*4882a593Smuzhiyun 	return -ENOMEM;
151*4882a593Smuzhiyun }
152*4882a593Smuzhiyun #endif
153*4882a593Smuzhiyun 
154*4882a593Smuzhiyun #endif	/* _SS_EBITMAP_H_ */
155