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