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 16 #ifndef _SS_EBITMAP_H_ 17 #define _SS_EBITMAP_H_ 18 19 #include <net/netlabel.h> 20 21 #ifdef CONFIG_64BIT 22 #define EBITMAP_NODE_SIZE 64 23 #else 24 #define EBITMAP_NODE_SIZE 32 25 #endif 26 27 #define EBITMAP_UNIT_NUMS \ 28 ((EBITMAP_NODE_SIZE - sizeof(void *) - sizeof(u32)) / \ 29 sizeof(unsigned long)) 30 #define EBITMAP_UNIT_SIZE BITS_PER_LONG 31 #define EBITMAP_SIZE (EBITMAP_UNIT_NUMS * EBITMAP_UNIT_SIZE) 32 #define EBITMAP_BIT 1ULL 33 #define EBITMAP_SHIFT_UNIT_SIZE(x) \ 34 (((x) >> EBITMAP_UNIT_SIZE / 2) >> EBITMAP_UNIT_SIZE / 2) 35 36 struct ebitmap_node { 37 struct ebitmap_node *next; 38 unsigned long maps[EBITMAP_UNIT_NUMS]; 39 u32 startbit; 40 }; 41 42 struct ebitmap { 43 struct ebitmap_node *node; /* first node in the bitmap */ 44 u32 highbit; /* highest position in the total bitmap */ 45 }; 46 47 #define ebitmap_length(e) ((e)->highbit) 48 49 static inline unsigned int ebitmap_start_positive(const struct ebitmap *e, 50 struct ebitmap_node **n) 51 { 52 unsigned int ofs; 53 54 for (*n = e->node; *n; *n = (*n)->next) { 55 ofs = find_first_bit((*n)->maps, EBITMAP_SIZE); 56 if (ofs < EBITMAP_SIZE) 57 return (*n)->startbit + ofs; 58 } 59 return ebitmap_length(e); 60 } 61 62 static inline void ebitmap_init(struct ebitmap *e) 63 { 64 memset(e, 0, sizeof(*e)); 65 } 66 67 static inline unsigned int ebitmap_next_positive(const struct ebitmap *e, 68 struct ebitmap_node **n, 69 unsigned int bit) 70 { 71 unsigned int ofs; 72 73 ofs = find_next_bit((*n)->maps, EBITMAP_SIZE, bit - (*n)->startbit + 1); 74 if (ofs < EBITMAP_SIZE) 75 return ofs + (*n)->startbit; 76 77 for (*n = (*n)->next; *n; *n = (*n)->next) { 78 ofs = find_first_bit((*n)->maps, EBITMAP_SIZE); 79 if (ofs < EBITMAP_SIZE) 80 return ofs + (*n)->startbit; 81 } 82 return ebitmap_length(e); 83 } 84 85 #define EBITMAP_NODE_INDEX(node, bit) \ 86 (((bit) - (node)->startbit) / EBITMAP_UNIT_SIZE) 87 #define EBITMAP_NODE_OFFSET(node, bit) \ 88 (((bit) - (node)->startbit) % EBITMAP_UNIT_SIZE) 89 90 static inline int ebitmap_node_get_bit(const struct ebitmap_node *n, 91 unsigned int bit) 92 { 93 unsigned int index = EBITMAP_NODE_INDEX(n, bit); 94 unsigned int ofs = EBITMAP_NODE_OFFSET(n, bit); 95 96 BUG_ON(index >= EBITMAP_UNIT_NUMS); 97 if ((n->maps[index] & (EBITMAP_BIT << ofs))) 98 return 1; 99 return 0; 100 } 101 102 static inline void ebitmap_node_set_bit(struct ebitmap_node *n, 103 unsigned int bit) 104 { 105 unsigned int index = EBITMAP_NODE_INDEX(n, bit); 106 unsigned int ofs = EBITMAP_NODE_OFFSET(n, bit); 107 108 BUG_ON(index >= EBITMAP_UNIT_NUMS); 109 n->maps[index] |= (EBITMAP_BIT << ofs); 110 } 111 112 static inline void ebitmap_node_clr_bit(struct ebitmap_node *n, 113 unsigned int bit) 114 { 115 unsigned int index = EBITMAP_NODE_INDEX(n, bit); 116 unsigned int ofs = EBITMAP_NODE_OFFSET(n, bit); 117 118 BUG_ON(index >= EBITMAP_UNIT_NUMS); 119 n->maps[index] &= ~(EBITMAP_BIT << ofs); 120 } 121 122 #define ebitmap_for_each_positive_bit(e, n, bit) \ 123 for ((bit) = ebitmap_start_positive(e, &(n)); \ 124 (bit) < ebitmap_length(e); \ 125 (bit) = ebitmap_next_positive(e, &(n), bit)) 126 127 int ebitmap_cmp(const struct ebitmap *e1, const struct ebitmap *e2); 128 int ebitmap_cpy(struct ebitmap *dst, const struct ebitmap *src); 129 int ebitmap_and(struct ebitmap *dst, const struct ebitmap *e1, 130 const struct ebitmap *e2); 131 int ebitmap_contains(const struct ebitmap *e1, const struct ebitmap *e2, 132 u32 last_e2bit); 133 int ebitmap_get_bit(const struct ebitmap *e, unsigned long bit); 134 int ebitmap_set_bit(struct ebitmap *e, unsigned long bit, int value); 135 void ebitmap_destroy(struct ebitmap *e); 136 int ebitmap_read(struct ebitmap *e, void *fp); 137 int ebitmap_write(const struct ebitmap *e, void *fp); 138 u32 ebitmap_hash(const struct ebitmap *e, u32 hash); 139 140 #ifdef CONFIG_NETLABEL 141 int ebitmap_netlbl_export(struct ebitmap *ebmap, 142 struct netlbl_lsm_catmap **catmap); 143 int ebitmap_netlbl_import(struct ebitmap *ebmap, 144 struct netlbl_lsm_catmap *catmap); 145 #else 146 static inline int ebitmap_netlbl_export(struct ebitmap *ebmap, 147 struct netlbl_lsm_catmap **catmap) 148 { 149 return -ENOMEM; 150 } 151 static inline int ebitmap_netlbl_import(struct ebitmap *ebmap, 152 struct netlbl_lsm_catmap *catmap) 153 { 154 return -ENOMEM; 155 } 156 #endif 157 158 #endif /* _SS_EBITMAP_H_ */ 159