diff options
Diffstat (limited to 'security/selinux/ss/ebitmap.h')
| -rw-r--r-- | security/selinux/ss/ebitmap.h | 151 |
1 files changed, 151 insertions, 0 deletions
diff --git a/security/selinux/ss/ebitmap.h b/security/selinux/ss/ebitmap.h new file mode 100644 index 000000000..9637b8c71 --- /dev/null +++ b/security/selinux/ss/ebitmap.h @@ -0,0 +1,151 @@ +/* + * An extensible bitmap is a bitmap that supports an + * arbitrary number of bits. Extensible bitmaps are + * used to represent sets of values, such as types, + * roles, categories, and classes. + * + * Each extensible bitmap is implemented as a linked + * list of bitmap nodes, where each bitmap node has + * an explicitly specified starting bit position within + * the total bitmap. + * + * Author : Stephen Smalley, <sds@epoch.ncsc.mil> + */ +#ifndef _SS_EBITMAP_H_ +#define _SS_EBITMAP_H_ + +#include <net/netlabel.h> + +#ifdef CONFIG_64BIT +#define EBITMAP_NODE_SIZE 64 +#else +#define EBITMAP_NODE_SIZE 32 +#endif + +#define EBITMAP_UNIT_NUMS ((EBITMAP_NODE_SIZE-sizeof(void *)-sizeof(u32))\ + / sizeof(unsigned long)) +#define EBITMAP_UNIT_SIZE BITS_PER_LONG +#define EBITMAP_SIZE (EBITMAP_UNIT_NUMS * EBITMAP_UNIT_SIZE) +#define EBITMAP_BIT 1ULL +#define EBITMAP_SHIFT_UNIT_SIZE(x) \ + (((x) >> EBITMAP_UNIT_SIZE / 2) >> EBITMAP_UNIT_SIZE / 2) + +struct ebitmap_node { + struct ebitmap_node *next; + unsigned long maps[EBITMAP_UNIT_NUMS]; + u32 startbit; +}; + +struct ebitmap { + struct ebitmap_node *node; /* first node in the bitmap */ + u32 highbit; /* highest position in the total bitmap */ +}; + +#define ebitmap_length(e) ((e)->highbit) + +static inline unsigned int ebitmap_start_positive(struct ebitmap *e, + struct ebitmap_node **n) +{ + unsigned int ofs; + + for (*n = e->node; *n; *n = (*n)->next) { + ofs = find_first_bit((*n)->maps, EBITMAP_SIZE); + if (ofs < EBITMAP_SIZE) + return (*n)->startbit + ofs; + } + return ebitmap_length(e); +} + +static inline void ebitmap_init(struct ebitmap *e) +{ + memset(e, 0, sizeof(*e)); +} + +static inline unsigned int ebitmap_next_positive(struct ebitmap *e, + struct ebitmap_node **n, + unsigned int bit) +{ + unsigned int ofs; + + ofs = find_next_bit((*n)->maps, EBITMAP_SIZE, bit - (*n)->startbit + 1); + if (ofs < EBITMAP_SIZE) + return ofs + (*n)->startbit; + + for (*n = (*n)->next; *n; *n = (*n)->next) { + ofs = find_first_bit((*n)->maps, EBITMAP_SIZE); + if (ofs < EBITMAP_SIZE) + return ofs + (*n)->startbit; + } + return ebitmap_length(e); +} + +#define EBITMAP_NODE_INDEX(node, bit) \ + (((bit) - (node)->startbit) / EBITMAP_UNIT_SIZE) +#define EBITMAP_NODE_OFFSET(node, bit) \ + (((bit) - (node)->startbit) % EBITMAP_UNIT_SIZE) + +static inline int ebitmap_node_get_bit(struct ebitmap_node *n, + unsigned int bit) +{ + unsigned int index = EBITMAP_NODE_INDEX(n, bit); + unsigned int ofs = EBITMAP_NODE_OFFSET(n, bit); + + BUG_ON(index >= EBITMAP_UNIT_NUMS); + if ((n->maps[index] & (EBITMAP_BIT << ofs))) + return 1; + return 0; +} + +static inline void ebitmap_node_set_bit(struct ebitmap_node *n, + unsigned int bit) +{ + unsigned int index = EBITMAP_NODE_INDEX(n, bit); + unsigned int ofs = EBITMAP_NODE_OFFSET(n, bit); + + BUG_ON(index >= EBITMAP_UNIT_NUMS); + n->maps[index] |= (EBITMAP_BIT << ofs); +} + +static inline void ebitmap_node_clr_bit(struct ebitmap_node *n, + unsigned int bit) +{ + unsigned int index = EBITMAP_NODE_INDEX(n, bit); + unsigned int ofs = EBITMAP_NODE_OFFSET(n, bit); + + BUG_ON(index >= EBITMAP_UNIT_NUMS); + n->maps[index] &= ~(EBITMAP_BIT << ofs); +} + +#define ebitmap_for_each_positive_bit(e, n, bit) \ + for (bit = ebitmap_start_positive(e, &n); \ + bit < ebitmap_length(e); \ + bit = ebitmap_next_positive(e, &n, bit)) \ + +int ebitmap_cmp(struct ebitmap *e1, struct ebitmap *e2); +int ebitmap_cpy(struct ebitmap *dst, struct ebitmap *src); +int ebitmap_contains(struct ebitmap *e1, struct ebitmap *e2, u32 last_e2bit); +int ebitmap_get_bit(struct ebitmap *e, unsigned long bit); +int ebitmap_set_bit(struct ebitmap *e, unsigned long bit, int value); +void ebitmap_destroy(struct ebitmap *e); +int ebitmap_read(struct ebitmap *e, void *fp); +int ebitmap_write(struct ebitmap *e, void *fp); + +#ifdef CONFIG_NETLABEL +int ebitmap_netlbl_export(struct ebitmap *ebmap, + struct netlbl_lsm_catmap **catmap); +int ebitmap_netlbl_import(struct ebitmap *ebmap, + struct netlbl_lsm_catmap *catmap); +#else +static inline int ebitmap_netlbl_export(struct ebitmap *ebmap, + struct netlbl_lsm_catmap **catmap) +{ + return -ENOMEM; +} +static inline int ebitmap_netlbl_import(struct ebitmap *ebmap, + struct netlbl_lsm_catmap *catmap) +{ + return -ENOMEM; +} +#endif + +#endif /* _SS_EBITMAP_H_ */ |