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 struct type_set *type_names; 52 53 struct constraint_expr *next; /* next expression */ 54 }; 55 56 struct constraint_node { 57 u32 permissions; /* constrained permissions */ 58 struct constraint_expr *expr; /* constraint on permissions */ 59 struct constraint_node *next; /* next constraint */ 60 }; 61 62 #endif /* _SS_CONSTRAINT_H_ */ 63