xref: /linux/security/selinux/ss/sidtab.h (revision c0c914eca7f251c70facc37dfebeaf176601918d)
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@epoch.ncsc.mil>
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 
57