xref: /linux/security/selinux/ss/avtab.h (revision 0d456bad36d42d16022be045c8a53ddbb59ee478)
1 /*
2  * An access vector table (avtab) is a hash table
3  * of access vectors and transition types indexed
4  * by a type pair and a class.  An access vector
5  * table is used to represent the type enforcement
6  * tables.
7  *
8  *  Author : Stephen Smalley, <sds@epoch.ncsc.mil>
9  */
10 
11 /* Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com>
12  *
13  * 	Added conditional policy language extensions
14  *
15  * Copyright (C) 2003 Tresys Technology, LLC
16  *	This program is free software; you can redistribute it and/or modify
17  *	it under the terms of the GNU General Public License as published by
18  *	the Free Software Foundation, version 2.
19  *
20  * Updated: Yuichi Nakamura <ynakam@hitachisoft.jp>
21  * 	Tuned number of hash slots for avtab to reduce memory usage
22  */
23 #ifndef _SS_AVTAB_H_
24 #define _SS_AVTAB_H_
25 
26 struct avtab_key {
27 	u16 source_type;	/* source type */
28 	u16 target_type;	/* target type */
29 	u16 target_class;	/* target object class */
30 #define AVTAB_ALLOWED		0x0001
31 #define AVTAB_AUDITALLOW	0x0002
32 #define AVTAB_AUDITDENY		0x0004
33 #define AVTAB_AV		(AVTAB_ALLOWED | AVTAB_AUDITALLOW | AVTAB_AUDITDENY)
34 #define AVTAB_TRANSITION	0x0010
35 #define AVTAB_MEMBER		0x0020
36 #define AVTAB_CHANGE		0x0040
37 #define AVTAB_TYPE		(AVTAB_TRANSITION | AVTAB_MEMBER | AVTAB_CHANGE)
38 #define AVTAB_ENABLED_OLD   0x80000000 /* reserved for used in cond_avtab */
39 #define AVTAB_ENABLED		0x8000 /* reserved for used in cond_avtab */
40 	u16 specified;	/* what field is specified */
41 };
42 
43 struct avtab_datum {
44 	u32 data; /* access vector or type value */
45 };
46 
47 struct avtab_node {
48 	struct avtab_key key;
49 	struct avtab_datum datum;
50 	struct avtab_node *next;
51 };
52 
53 struct avtab {
54 	struct avtab_node **htable;
55 	u32 nel;	/* number of elements */
56 	u32 nslot;      /* number of hash slots */
57 	u16 mask;       /* mask to compute hash func */
58 
59 };
60 
61 int avtab_init(struct avtab *);
62 int avtab_alloc(struct avtab *, u32);
63 struct avtab_datum *avtab_search(struct avtab *h, struct avtab_key *k);
64 void avtab_destroy(struct avtab *h);
65 void avtab_hash_eval(struct avtab *h, char *tag);
66 
67 struct policydb;
68 int avtab_read_item(struct avtab *a, void *fp, struct policydb *pol,
69 		    int (*insert)(struct avtab *a, struct avtab_key *k,
70 				  struct avtab_datum *d, void *p),
71 		    void *p);
72 
73 int avtab_read(struct avtab *a, void *fp, struct policydb *pol);
74 int avtab_write_item(struct policydb *p, struct avtab_node *cur, void *fp);
75 int avtab_write(struct policydb *p, struct avtab *a, void *fp);
76 
77 struct avtab_node *avtab_insert_nonunique(struct avtab *h, struct avtab_key *key,
78 					  struct avtab_datum *datum);
79 
80 struct avtab_node *avtab_search_node(struct avtab *h, struct avtab_key *key);
81 
82 struct avtab_node *avtab_search_node_next(struct avtab_node *node, int specified);
83 
84 void avtab_cache_init(void);
85 void avtab_cache_destroy(void);
86 
87 #define MAX_AVTAB_HASH_BITS 11
88 #define MAX_AVTAB_HASH_BUCKETS (1 << MAX_AVTAB_HASH_BITS)
89 
90 #endif	/* _SS_AVTAB_H_ */
91 
92