1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /* Authors: Karl MacMillan <kmacmillan@tresys.com>
3  *          Frank Mayer <mayerf@tresys.com>
4  *
5  * Copyright (C) 2003 - 2004 Tresys Technology, LLC
6  */
7 
8 #ifndef _CONDITIONAL_H_
9 #define _CONDITIONAL_H_
10 
11 #include "avtab.h"
12 #include "symtab.h"
13 #include "policydb.h"
14 #include "../include/conditional.h"
15 
16 #define COND_EXPR_MAXDEPTH 10
17 
18 /*
19  * A conditional expression is a list of operators and operands
20  * in reverse polish notation.
21  */
22 struct cond_expr {
23 #define COND_BOOL	1 /* plain bool */
24 #define COND_NOT	2 /* !bool */
25 #define COND_OR		3 /* bool || bool */
26 #define COND_AND	4 /* bool && bool */
27 #define COND_XOR	5 /* bool ^ bool */
28 #define COND_EQ		6 /* bool == bool */
29 #define COND_NEQ	7 /* bool != bool */
30 #define COND_LAST	COND_NEQ
31 	__u32 expr_type;
32 	__u32 bool;
33 	struct cond_expr *next;
34 };
35 
36 /*
37  * Each cond_node contains a list of rules to be enabled/disabled
38  * depending on the current value of the conditional expression. This
39  * struct is for that list.
40  */
41 struct cond_av_list {
42 	struct avtab_node *node;
43 	struct cond_av_list *next;
44 };
45 
46 /*
47  * A cond node represents a conditional block in a policy. It
48  * contains a conditional expression, the current state of the expression,
49  * two lists of rules to enable/disable depending on the value of the
50  * expression (the true list corresponds to if and the false list corresponds
51  * to else)..
52  */
53 struct cond_node {
54 	int cur_state;
55 	struct cond_expr *expr;
56 	struct cond_av_list *true_list;
57 	struct cond_av_list *false_list;
58 	struct cond_node *next;
59 };
60 
61 int cond_policydb_init(struct policydb *p);
62 void cond_policydb_destroy(struct policydb *p);
63 
64 int cond_init_bool_indexes(struct policydb *p);
65 int cond_destroy_bool(void *key, void *datum, void *p);
66 
67 int cond_index_bool(void *key, void *datum, void *datap);
68 
69 int cond_read_bool(struct policydb *p, struct hashtab *h, void *fp);
70 int cond_read_list(struct policydb *p, void *fp);
71 int cond_write_bool(void *key, void *datum, void *ptr);
72 int cond_write_list(struct policydb *p, struct cond_node *list, void *fp);
73 
74 void cond_compute_av(struct avtab *ctab, struct avtab_key *key,
75 		struct av_decision *avd, struct extended_perms *xperms);
76 void cond_compute_xperms(struct avtab *ctab, struct avtab_key *key,
77 		struct extended_perms_decision *xpermd);
78 int evaluate_cond_node(struct policydb *p, struct cond_node *node);
79 
80 #endif /* _CONDITIONAL_H_ */
81