xref: /linux/security/selinux/ss/constraint.h (revision 79790b6818e96c58fe2bffee1b418c16e64e7b80)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * A constraint is a condition that must be satisfied in
4  * order for one or more permissions to be granted.
5  * Constraints are used to impose additional restrictions
6  * beyond the type-based rules in `te' or the role-based
7  * transition rules in `rbac'.  Constraints are typically
8  * used to prevent a process from transitioning to a new user
9  * identity or role unless it is in a privileged type.
10  * Constraints are likewise typically used to prevent a
11  * process from labeling an object with a different user
12  * identity.
13  *
14  * Author : Stephen Smalley, <stephen.smalley.work@gmail.com>
15  */
16 
17 #ifndef _SS_CONSTRAINT_H_
18 #define _SS_CONSTRAINT_H_
19 
20 #include "ebitmap.h"
21 
22 #define CEXPR_MAXDEPTH 5
23 
24 struct constraint_expr {
25 #define CEXPR_NOT   1 /* not expr */
26 #define CEXPR_AND   2 /* expr and expr */
27 #define CEXPR_OR    3 /* expr or expr */
28 #define CEXPR_ATTR  4 /* attr op attr */
29 #define CEXPR_NAMES 5 /* attr op names */
30 	u32 expr_type; /* expression type */
31 
32 #define CEXPR_USER    1 /* user */
33 #define CEXPR_ROLE    2 /* role */
34 #define CEXPR_TYPE    4 /* type */
35 #define CEXPR_TARGET  8 /* target if set, source otherwise */
36 #define CEXPR_XTARGET 16 /* special 3rd target for validatetrans rule */
37 #define CEXPR_L1L2    32 /* low level 1 vs. low level 2 */
38 #define CEXPR_L1H2    64 /* low level 1 vs. high level 2 */
39 #define CEXPR_H1L2    128 /* high level 1 vs. low level 2 */
40 #define CEXPR_H1H2    256 /* high level 1 vs. high level 2 */
41 #define CEXPR_L1H1    512 /* low level 1 vs. high level 1 */
42 #define CEXPR_L2H2    1024 /* low level 2 vs. high level 2 */
43 	u32 attr; /* attribute */
44 
45 #define CEXPR_EQ     1 /* == or eq */
46 #define CEXPR_NEQ    2 /* != */
47 #define CEXPR_DOM    3 /* dom */
48 #define CEXPR_DOMBY  4 /* domby  */
49 #define CEXPR_INCOMP 5 /* incomp */
50 	u32 op; /* operator */
51 
52 	struct ebitmap names; /* names */
53 	struct type_set *type_names;
54 
55 	struct constraint_expr *next; /* next expression */
56 };
57 
58 struct constraint_node {
59 	u32 permissions; /* constrained permissions */
60 	struct constraint_expr *expr; /* constraint on permissions */
61 	struct constraint_node *next; /* next constraint */
62 };
63 
64 #endif /* _SS_CONSTRAINT_H_ */
65