xref: /openbmc/linux/security/selinux/ss/constraint.h (revision 0fe53224)
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 #ifndef _SS_CONSTRAINT_H_
17 #define _SS_CONSTRAINT_H_
18 
19 #include "ebitmap.h"
20 
21 #define CEXPR_MAXDEPTH 5
22 
23 struct constraint_expr {
24 #define CEXPR_NOT		1 /* not expr */
25 #define CEXPR_AND		2 /* expr and expr */
26 #define CEXPR_OR		3 /* expr or expr */
27 #define CEXPR_ATTR		4 /* attr op attr */
28 #define CEXPR_NAMES		5 /* attr op names */
29 	u32 expr_type;		/* expression type */
30 
31 #define CEXPR_USER 1		/* user */
32 #define CEXPR_ROLE 2		/* role */
33 #define CEXPR_TYPE 4		/* type */
34 #define CEXPR_TARGET 8		/* target if set, source otherwise */
35 #define CEXPR_XTARGET 16	/* special 3rd target for validatetrans rule */
36 #define CEXPR_L1L2 32		/* low level 1 vs. low level 2 */
37 #define CEXPR_L1H2 64		/* low level 1 vs. high level 2 */
38 #define CEXPR_H1L2 128		/* high level 1 vs. low level 2 */
39 #define CEXPR_H1H2 256		/* high level 1 vs. high level 2 */
40 #define CEXPR_L1H1 512		/* low level 1 vs. high level 1 */
41 #define CEXPR_L2H2 1024		/* low level 2 vs. high level 2 */
42 	u32 attr;		/* attribute */
43 
44 #define CEXPR_EQ     1		/* == or eq */
45 #define CEXPR_NEQ    2		/* != */
46 #define CEXPR_DOM    3		/* dom */
47 #define CEXPR_DOMBY  4		/* domby  */
48 #define CEXPR_INCOMP 5		/* incomp */
49 	u32 op;			/* operator */
50 
51 	struct ebitmap names;	/* names */
52 	struct type_set *type_names;
53 
54 	struct constraint_expr *next;   /* next expression */
55 };
56 
57 struct constraint_node {
58 	u32 permissions;	/* constrained permissions */
59 	struct constraint_expr *expr;	/* constraint on permissions */
60 	struct constraint_node *next;	/* next constraint */
61 };
62 
63 #endif	/* _SS_CONSTRAINT_H_ */
64