security/selinux/ss/constraint.h

   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, <sds@tycho.nsa.gov>
  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_ */