security/selinux/ss/sidtab.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  * A security identifier table (sidtab) is a hash table
   4  * of security context structures indexed by SID value.
   5  *
   6  * Author : Stephen Smalley, <sds@tycho.nsa.gov>
   7  */
   8 #ifndef _SS_SIDTAB_H_
   9 #define _SS_SIDTAB_H_
  10
  11 #include "context.h"
  12
  13 struct sidtab_node {
  14         u32 sid;                /* security identifier */
  15         struct context context; /* security context structure */
  16         struct sidtab_node *next;
  17 };
  18
  19 #define SIDTAB_HASH_BITS 7
  20 #define SIDTAB_HASH_BUCKETS (1 << SIDTAB_HASH_BITS)
  21 #define SIDTAB_HASH_MASK (SIDTAB_HASH_BUCKETS-1)
  22
  23 #define SIDTAB_SIZE SIDTAB_HASH_BUCKETS
  24
  25 struct sidtab {
  26         struct sidtab_node **htable;
  27         unsigned int nel;       /* number of elements */
  28         unsigned int next_sid;  /* next SID to allocate */
  29         unsigned char shutdown;
  30 #define SIDTAB_CACHE_LEN        3
  31         struct sidtab_node *cache[SIDTAB_CACHE_LEN];
  32         spinlock_t lock;
  33 };
  34
  35 int sidtab_init(struct sidtab *s);
  36 int sidtab_insert(struct sidtab *s, u32 sid, struct context *context);
  37 struct context *sidtab_search(struct sidtab *s, u32 sid);
  38 struct context *sidtab_search_force(struct sidtab *s, u32 sid);
  39
  40 int sidtab_map(struct sidtab *s,
  41                int (*apply) (u32 sid,
  42                              struct context *context,
  43                              void *args),
  44                void *args);
  45
  46 int sidtab_context_to_sid(struct sidtab *s,
  47                           struct context *context,
  48                           u32 *sid);
  49
  50 void sidtab_hash_eval(struct sidtab *h, char *tag);
  51 void sidtab_destroy(struct sidtab *s);
  52 void sidtab_set(struct sidtab *dst, struct sidtab *src);
  53 void sidtab_shutdown(struct sidtab *s);
  54
  55 #endif  /* _SS_SIDTAB_H_ */
  56
  57