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 34 struct ebitmap_node { 35 struct ebitmap_node *next; 36 unsigned long maps[EBITMAP_UNIT_NUMS]; 37 u32 startbit; 38 }; 39 40 struct 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 47 static 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 60 static inline void ebitmap_init(struct ebitmap *e) 61 { 62 memset(e, 0, sizeof(*e)); 63 } 64 65 static 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 88 static 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 } 99 100 static 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 } 109 110 static 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)) \ 124 125 int ebitmap_cmp(struct ebitmap *e1, struct ebitmap *e2); 126 int ebitmap_cpy(struct ebitmap *dst, struct ebitmap *src); 127 int ebitmap_and(struct ebitmap *dst, struct ebitmap *e1, struct ebitmap *e2); 128 int ebitmap_contains(struct ebitmap *e1, struct ebitmap *e2, u32 last_e2bit); 129 int ebitmap_get_bit(struct ebitmap *e, unsigned long bit); 130 int ebitmap_set_bit(struct ebitmap *e, unsigned long bit, int value); 131 void ebitmap_destroy(struct ebitmap *e); 132 int ebitmap_read(struct ebitmap *e, void *fp); 133 int ebitmap_write(struct ebitmap *e, void *fp); 134 u32 ebitmap_hash(const struct ebitmap *e, u32 hash); 135 136 #ifdef CONFIG_NETLABEL 137 int ebitmap_netlbl_export(struct ebitmap *ebmap, 138 struct netlbl_lsm_catmap **catmap); 139 int ebitmap_netlbl_import(struct ebitmap *ebmap, 140 struct netlbl_lsm_catmap *catmap); 141 #else 142 static inline int ebitmap_netlbl_export(struct ebitmap *ebmap, 143 struct netlbl_lsm_catmap **catmap) 144 { 145 return -ENOMEM; 146 } 147 static 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