ebitmap.h 2.7 KB

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  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. #include <net/netlabel.h>
  17. #define MAPTYPE u64 /* portion of bitmap in each node */
  18. #define MAPSIZE (sizeof(MAPTYPE) * 8) /* number of bits in node bitmap */
  19. #define MAPBIT 1ULL /* a bit in the node bitmap */
  20. struct ebitmap_node {
  21. u32 startbit; /* starting position in the total bitmap */
  22. MAPTYPE map; /* this node's portion of the bitmap */
  23. struct ebitmap_node *next;
  24. };
  25. struct ebitmap {
  26. struct ebitmap_node *node; /* first node in the bitmap */
  27. u32 highbit; /* highest position in the total bitmap */
  28. };
  29. #define ebitmap_length(e) ((e)->highbit)
  30. #define ebitmap_startbit(e) ((e)->node ? (e)->node->startbit : 0)
  31. static inline unsigned int ebitmap_start(struct ebitmap *e,
  32. struct ebitmap_node **n)
  33. {
  34. *n = e->node;
  35. return ebitmap_startbit(e);
  36. }
  37. static inline void ebitmap_init(struct ebitmap *e)
  38. {
  39. memset(e, 0, sizeof(*e));
  40. }
  41. static inline unsigned int ebitmap_next(struct ebitmap_node **n,
  42. unsigned int bit)
  43. {
  44. if ((bit == ((*n)->startbit + MAPSIZE - 1)) &&
  45. (*n)->next) {
  46. *n = (*n)->next;
  47. return (*n)->startbit;
  48. }
  49. return (bit+1);
  50. }
  51. static inline int ebitmap_node_get_bit(struct ebitmap_node * n,
  52. unsigned int bit)
  53. {
  54. if (n->map & (MAPBIT << (bit - n->startbit)))
  55. return 1;
  56. return 0;
  57. }
  58. #define ebitmap_for_each_bit(e, n, bit) \
  59. for (bit = ebitmap_start(e, &n); bit < ebitmap_length(e); bit = ebitmap_next(&n, bit)) \
  60. int ebitmap_cmp(struct ebitmap *e1, struct ebitmap *e2);
  61. int ebitmap_cpy(struct ebitmap *dst, struct ebitmap *src);
  62. int ebitmap_contains(struct ebitmap *e1, struct ebitmap *e2);
  63. int ebitmap_get_bit(struct ebitmap *e, unsigned long bit);
  64. int ebitmap_set_bit(struct ebitmap *e, unsigned long bit, int value);
  65. void ebitmap_destroy(struct ebitmap *e);
  66. int ebitmap_read(struct ebitmap *e, void *fp);
  67. #ifdef CONFIG_NETLABEL
  68. int ebitmap_netlbl_export(struct ebitmap *ebmap,
  69. struct netlbl_lsm_secattr_catmap **catmap);
  70. int ebitmap_netlbl_import(struct ebitmap *ebmap,
  71. struct netlbl_lsm_secattr_catmap *catmap);
  72. #else
  73. static inline int ebitmap_netlbl_export(struct ebitmap *ebmap,
  74. struct netlbl_lsm_secattr_catmap **catmap)
  75. {
  76. return -ENOMEM;
  77. }
  78. static inline int ebitmap_netlbl_import(struct ebitmap *ebmap,
  79. struct netlbl_lsm_secattr_catmap *catmap)
  80. {
  81. return -ENOMEM;
  82. }
  83. #endif
  84. #endif /* _SS_EBITMAP_H_ */