security/selinux/ss/constraint.h

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