security/selinux/ss/sidtab.h

   1 /*
   2  * A security identifier table (sidtab) is a hash table
   3  * of security context structures indexed by SID value.
   4  *
   5  * Author : Stephen Smalley, <sds@tycho.nsa.gov>
   6  */
   7 #ifndef _SS_SIDTAB_H_
   8 #define _SS_SIDTAB_H_
   9
  10 #include "context.h"
  11
  12 struct sidtab_node {
  13         u32 sid;                /* security identifier */
  14         struct context context; /* security context structure */
  15         struct sidtab_node *next;
  16 };
  17
  18 #define SIDTAB_HASH_BITS 7
  19 #define SIDTAB_HASH_BUCKETS (1 << SIDTAB_HASH_BITS)
  20 #define SIDTAB_HASH_MASK (SIDTAB_HASH_BUCKETS-1)
  21
  22 #define SIDTAB_SIZE SIDTAB_HASH_BUCKETS
  23
  24 struct sidtab {
  25         struct sidtab_node **htable;
  26         unsigned int nel;       /* number of elements */
  27         unsigned int next_sid;  /* next SID to allocate */
  28         unsigned char shutdown;
  29 #define SIDTAB_CACHE_LEN        3
  30         struct sidtab_node *cache[SIDTAB_CACHE_LEN];
  31         spinlock_t lock;
  32 };
  33
  34 int sidtab_init(struct sidtab *s);
  35 int sidtab_insert(struct sidtab *s, u32 sid, struct context *context);
  36 struct context *sidtab_search(struct sidtab *s, u32 sid);
  37 struct context *sidtab_search_force(struct sidtab *s, u32 sid);
  38
  39 int sidtab_map(struct sidtab *s,
  40                int (*apply) (u32 sid,
  41                              struct context *context,
  42                              void *args),
  43                void *args);
  44
  45 int sidtab_context_to_sid(struct sidtab *s,
  46                           struct context *context,
  47                           u32 *sid);
  48
  49 void sidtab_hash_eval(struct sidtab *h, char *tag);
  50 void sidtab_destroy(struct sidtab *s);
  51 void sidtab_set(struct sidtab *dst, struct sidtab *src);
  52 void sidtab_shutdown(struct sidtab *s);
  53
  54 #endif  /* _SS_SIDTAB_H_ */
  55
  56