/* Authors: Karl MacMillan <kmacmillan@tresys.com>
* Frank Mayer <mayerf@tresys.com>
*
* Copyright (C) 2003 - 2005 Tresys Technology, LLC
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef _SEPOL_POLICYDB_CONDITIONAL_H_
#define _SEPOL_POLICYDB_CONDITIONAL_H_
#include <sepol/policydb/flask_types.h>
#include <sepol/policydb/avtab.h>
#include <sepol/policydb/symtab.h>
#include <sepol/policydb/policydb.h>
#ifdef __cplusplus
extern "C" {
#endif
#define COND_EXPR_MAXDEPTH 10
/* this is the max unique bools in a conditional expression
* for which we precompute all outcomes for the expression.
*
* NOTE - do _NOT_ use value greater than 5 because
* cond_node_t->expr_pre_comp can only hold at most 32 values
*/
#define COND_MAX_BOOLS 5
/*
* A conditional expression is a list of operators and operands
* in reverse polish notation.
*/
typedef struct cond_expr {
#define COND_BOOL 1 /* plain bool */
#define COND_NOT 2 /* !bool */
#define COND_OR 3 /* bool || bool */
#define COND_AND 4 /* bool && bool */
#define COND_XOR 5 /* bool ^ bool */
#define COND_EQ 6 /* bool == bool */
#define COND_NEQ 7 /* bool != bool */
#define COND_LAST COND_NEQ
uint32_t expr_type;
uint32_t bool;
struct cond_expr *next;
} cond_expr_t;
/*
* Each cond_node_t contains a list of rules to be enabled/disabled
* depending on the current value of the conditional expression. This
* struct is for that list.
*/
typedef struct cond_av_list {
avtab_ptr_t node;
struct cond_av_list *next;
} cond_av_list_t;
/*
* A cond node represents a conditional block in a policy. It
* contains a conditional expression, the current state of the expression,
* two lists of rules to enable/disable depending on the value of the
* expression (the true list corresponds to if and the false list corresponds
* to else)..
*/
typedef struct cond_node {
int cur_state;
cond_expr_t *expr;
/* these true/false lists point into te_avtab when that is used */
cond_av_list_t *true_list;
cond_av_list_t *false_list;
/* and these are used during parsing and for modules */
avrule_t *avtrue_list;
avrule_t *avfalse_list;
/* these fields are not written to binary policy */
unsigned int nbools;
uint32_t bool_ids[COND_MAX_BOOLS];
uint32_t expr_pre_comp;
struct cond_node *next;
/* a tunable conditional, calculated and used at expansion */
#define COND_NODE_FLAGS_TUNABLE 0x01
uint32_t flags;
} cond_node_t;
extern int cond_evaluate_expr(policydb_t * p, cond_expr_t * expr);
extern cond_expr_t *cond_copy_expr(cond_expr_t * expr);
extern int cond_expr_equal(cond_node_t * a, cond_node_t * b);
extern int cond_normalize_expr(policydb_t * p, cond_node_t * cn);
extern void cond_node_destroy(cond_node_t * node);
extern void cond_expr_destroy(cond_expr_t * expr);
extern cond_node_t *cond_node_find(policydb_t * p,
cond_node_t * needle, cond_node_t * haystack,
int *was_created);
extern cond_node_t *cond_node_create(policydb_t * p, cond_node_t * node);
extern cond_node_t *cond_node_search(policydb_t * p, cond_node_t * list,
cond_node_t * cn);
extern int evaluate_conds(policydb_t * p);
extern avtab_datum_t *cond_av_list_search(avtab_key_t * key,
cond_av_list_t * cond_list);
extern void cond_av_list_destroy(cond_av_list_t * list);
extern void cond_optimize_lists(cond_list_t * cl);
extern int cond_policydb_init(policydb_t * p);
extern void cond_policydb_destroy(policydb_t * p);
extern void cond_list_destroy(cond_list_t * list);
extern int cond_init_bool_indexes(policydb_t * p);
extern int cond_destroy_bool(hashtab_key_t key, hashtab_datum_t datum, void *p);
extern int cond_index_bool(hashtab_key_t key, hashtab_datum_t datum,
void *datap);
extern int cond_read_bool(policydb_t * p, hashtab_t h, struct policy_file *fp);
extern int cond_read_list(policydb_t * p, cond_list_t ** list, void *fp);
extern void cond_compute_av(avtab_t * ctab, avtab_key_t * key,
struct sepol_av_decision *avd);
#ifdef __cplusplus
}
#endif
#endif /* _CONDITIONAL_H_ */
