root/security/selinux/ss/constraint.h

INCLUDED FROM

/*
 * A constraint is a condition that must be satisfied in
 * order for one or more permissions to be granted.
 * Constraints are used to impose additional restrictions
 * beyond the type-based rules in `te' or the role-based
 * transition rules in `rbac'.  Constraints are typically
 * used to prevent a process from transitioning to a new user
 * identity or role unless it is in a privileged type.
 * Constraints are likewise typically used to prevent a
 * process from labeling an object with a different user
 * identity.
 *
 * Author : Stephen Smalley, <sds@epoch.ncsc.mil>
 */
#ifndef _SS_CONSTRAINT_H_
#define _SS_CONSTRAINT_H_

#include "ebitmap.h"

#define CEXPR_MAXDEPTH 5

struct constraint_expr {
#define CEXPR_NOT               1 /* not expr */
#define CEXPR_AND               2 /* expr and expr */
#define CEXPR_OR                3 /* expr or expr */
#define CEXPR_ATTR              4 /* attr op attr */
#define CEXPR_NAMES             5 /* attr op names */
        u32 expr_type;          /* expression type */

#define CEXPR_USER 1            /* user */
#define CEXPR_ROLE 2            /* role */
#define CEXPR_TYPE 4            /* type */
#define CEXPR_TARGET 8          /* target if set, source otherwise */
#define CEXPR_XTARGET 16        /* special 3rd target for validatetrans rule */
#define CEXPR_L1L2 32           /* low level 1 vs. low level 2 */
#define CEXPR_L1H2 64           /* low level 1 vs. high level 2 */
#define CEXPR_H1L2 128          /* high level 1 vs. low level 2 */
#define CEXPR_H1H2 256          /* high level 1 vs. high level 2 */
#define CEXPR_L1H1 512          /* low level 1 vs. high level 1 */
#define CEXPR_L2H2 1024         /* low level 2 vs. high level 2 */
        u32 attr;               /* attribute */

#define CEXPR_EQ     1          /* == or eq */
#define CEXPR_NEQ    2          /* != */
#define CEXPR_DOM    3          /* dom */
#define CEXPR_DOMBY  4          /* domby  */
#define CEXPR_INCOMP 5          /* incomp */
        u32 op;                 /* operator */

        struct ebitmap names;   /* names */

        struct constraint_expr *next;   /* next expression */
};

struct constraint_node {
        u32 permissions;        /* constrained permissions */
        struct constraint_expr *expr;   /* constraint on permissions */
        struct constraint_node *next;   /* next constraint */
};

#endif  /* _SS_CONSTRAINT_H_ */