xref: /openbmc/linux/security/selinux/ss/avtab.h (revision 0da85d1e)
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 #include <linux/flex_array.h>
27 
28 struct avtab_key {
29 	u16 source_type;	/* source type */
30 	u16 target_type;	/* target type */
31 	u16 target_class;	/* target object class */
32 #define AVTAB_ALLOWED		0x0001
33 #define AVTAB_AUDITALLOW	0x0002
34 #define AVTAB_AUDITDENY		0x0004
35 #define AVTAB_AV		(AVTAB_ALLOWED | AVTAB_AUDITALLOW | AVTAB_AUDITDENY)
36 #define AVTAB_TRANSITION	0x0010
37 #define AVTAB_MEMBER		0x0020
38 #define AVTAB_CHANGE		0x0040
39 #define AVTAB_TYPE		(AVTAB_TRANSITION | AVTAB_MEMBER | AVTAB_CHANGE)
40 #define AVTAB_ENABLED_OLD   0x80000000 /* reserved for used in cond_avtab */
41 #define AVTAB_ENABLED		0x8000 /* reserved for used in cond_avtab */
42 	u16 specified;	/* what field is specified */
43 };
44 
45 struct avtab_datum {
46 	u32 data; /* access vector or type value */
47 };
48 
49 struct avtab_node {
50 	struct avtab_key key;
51 	struct avtab_datum datum;
52 	struct avtab_node *next;
53 };
54 
55 struct avtab {
56 	struct flex_array *htable;
57 	u32 nel;	/* number of elements */
58 	u32 nslot;      /* number of hash slots */
59 	u32 mask;       /* mask to compute hash func */
60 
61 };
62 
63 int avtab_init(struct avtab *);
64 int avtab_alloc(struct avtab *, u32);
65 struct avtab_datum *avtab_search(struct avtab *h, struct avtab_key *k);
66 void avtab_destroy(struct avtab *h);
67 void avtab_hash_eval(struct avtab *h, char *tag);
68 
69 struct policydb;
70 int avtab_read_item(struct avtab *a, void *fp, struct policydb *pol,
71 		    int (*insert)(struct avtab *a, struct avtab_key *k,
72 				  struct avtab_datum *d, void *p),
73 		    void *p);
74 
75 int avtab_read(struct avtab *a, void *fp, struct policydb *pol);
76 int avtab_write_item(struct policydb *p, struct avtab_node *cur, void *fp);
77 int avtab_write(struct policydb *p, struct avtab *a, void *fp);
78 
79 struct avtab_node *avtab_insert_nonunique(struct avtab *h, struct avtab_key *key,
80 					  struct avtab_datum *datum);
81 
82 struct avtab_node *avtab_search_node(struct avtab *h, struct avtab_key *key);
83 
84 struct avtab_node *avtab_search_node_next(struct avtab_node *node, int specified);
85 
86 void avtab_cache_init(void);
87 void avtab_cache_destroy(void);
88 
89 #define MAX_AVTAB_HASH_BITS 16
90 #define MAX_AVTAB_HASH_BUCKETS (1 << MAX_AVTAB_HASH_BITS)
91 
92 #endif	/* _SS_AVTAB_H_ */
93 
94