1 /* 2 * An extensible bitmap is a bitmap that supports an 3 * arbitrary number of bits. Extensible bitmaps are 4 * used to represent sets of values, such as types, 5 * roles, categories, and classes. 6 * 7 * Each extensible bitmap is implemented as a linked 8 * list of bitmap nodes, where each bitmap node has 9 * an explicitly specified starting bit position within 10 * the total bitmap. 11 * 12 * Author : Stephen Smalley, <sds@epoch.ncsc.mil> 13 */ 14 #ifndef _SS_EBITMAP_H_ 15 #define _SS_EBITMAP_H_ 16 17 #include <net/netlabel.h> 18 19 #define MAPTYPE u64 /* portion of bitmap in each node */ 20 #define MAPSIZE (sizeof(MAPTYPE) * 8) /* number of bits in node bitmap */ 21 #define MAPBIT 1ULL /* a bit in the node bitmap */ 22 23 struct ebitmap_node { 24 u32 startbit; /* starting position in the total bitmap */ 25 MAPTYPE map; /* this node's portion of the bitmap */ 26 struct ebitmap_node *next; 27 }; 28 29 struct ebitmap { 30 struct ebitmap_node *node; /* first node in the bitmap */ 31 u32 highbit; /* highest position in the total bitmap */ 32 }; 33 34 #define ebitmap_length(e) ((e)->highbit) 35 #define ebitmap_startbit(e) ((e)->node ? (e)->node->startbit : 0) 36 37 static inline unsigned int ebitmap_start(struct ebitmap *e, 38 struct ebitmap_node **n) 39 { 40 *n = e->node; 41 return ebitmap_startbit(e); 42 } 43 44 static inline void ebitmap_init(struct ebitmap *e) 45 { 46 memset(e, 0, sizeof(*e)); 47 } 48 49 static inline unsigned int ebitmap_next(struct ebitmap_node **n, 50 unsigned int bit) 51 { 52 if ((bit == ((*n)->startbit + MAPSIZE - 1)) && 53 (*n)->next) { 54 *n = (*n)->next; 55 return (*n)->startbit; 56 } 57 58 return (bit+1); 59 } 60 61 static inline int ebitmap_node_get_bit(struct ebitmap_node * n, 62 unsigned int bit) 63 { 64 if (n->map & (MAPBIT << (bit - n->startbit))) 65 return 1; 66 return 0; 67 } 68 69 #define ebitmap_for_each_bit(e, n, bit) \ 70 for (bit = ebitmap_start(e, &n); bit < ebitmap_length(e); bit = ebitmap_next(&n, bit)) \ 71 72 int ebitmap_cmp(struct ebitmap *e1, struct ebitmap *e2); 73 int ebitmap_cpy(struct ebitmap *dst, struct ebitmap *src); 74 int ebitmap_contains(struct ebitmap *e1, struct ebitmap *e2); 75 int ebitmap_get_bit(struct ebitmap *e, unsigned long bit); 76 int ebitmap_set_bit(struct ebitmap *e, unsigned long bit, int value); 77 void ebitmap_destroy(struct ebitmap *e); 78 int ebitmap_read(struct ebitmap *e, void *fp); 79 80 #ifdef CONFIG_NETLABEL 81 int ebitmap_netlbl_export(struct ebitmap *ebmap, 82 struct netlbl_lsm_secattr_catmap **catmap); 83 int ebitmap_netlbl_import(struct ebitmap *ebmap, 84 struct netlbl_lsm_secattr_catmap *catmap); 85 #else 86 static inline int ebitmap_netlbl_export(struct ebitmap *ebmap, 87 struct netlbl_lsm_secattr_catmap **catmap) 88 { 89 return -ENOMEM; 90 } 91 static inline int ebitmap_netlbl_import(struct ebitmap *ebmap, 92 struct netlbl_lsm_secattr_catmap *catmap) 93 { 94 return -ENOMEM; 95 } 96 #endif 97 98 #endif /* _SS_EBITMAP_H_ */ 99